main: version 0.12.0

This allows TinyGo-built binaries to run under wasmtime, for example:

    tinygo build -o test.wasm -no-debug -target=wasm examples/test
    wasmtime run test.wasm 0

.circleci/config.yml

@@ -0,0 +1,351 @@
+version: 2.1
+
+commands:
+  submodules:
+    steps:
+      - run:
+          name: "Pull submodules"
+          command: git submodule update --init
+  apt-dependencies:
+    parameters:
+      llvm:
+        type: string
+    steps:
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            echo 'deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch<<parameters.llvm>> main' | sudo tee /etc/apt/sources.list.d/llvm.list
+            wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
+            sudo apt-get update
+            sudo apt-get install \
+                llvm<<parameters.llvm>>-dev \
+                clang<<parameters.llvm>> \
+                libclang<<parameters.llvm>>-dev \
+                lld<<parameters.llvm>> \
+                gcc-arm-linux-gnueabihf \
+                gcc-aarch64-linux-gnu \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+  install-node:
+    steps:
+      - run:
+          name: "Install node.js"
+          command: |
+            wget https://nodejs.org/dist/v10.15.1/node-v10.15.1-linux-x64.tar.xz
+            sudo tar -C /usr/local -xf node-v10.15.1-linux-x64.tar.xz
+            sudo ln -s /usr/local/node-v10.15.1-linux-x64/bin/node /usr/bin/node
+            rm node-v10.15.1-linux-x64.tar.xz
+  llvm-source-linux:
+    steps:
+      - restore_cache:
+          keys:
+            - llvm-source-9-v0
+      - run:
+          name: "Fetch LLVM source"
+          command: make llvm-source
+      - save_cache:
+          key: llvm-source-9-v0
+          paths:
+            - llvm-project
+  build-wasi-libc:
+    steps:
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-v0
+      - run:
+          name: "Build wasi-libc"
+          command: make wasi-libc CLANG=$PWD/llvm-build/bin/clang LLVM_AR=$PWD/llvm-build/bin/llvm-ar LLVM_NM=$PWD/llvm-build/bin/llvm-nm
+      - save_cache:
+          key: wasi-libc-sysroot-v0
+          paths:
+            - lib/wasi-libc/sysroot
+  test-linux:
+    steps:
+      - checkout
+      - submodules
+      - apt-dependencies:
+          llvm: "-9"
+      - install-node
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - run: go install .
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-systemclang-v0
+      - run: make wasi-libc
+      - save_cache:
+          key: wasi-libc-sysroot-systemclang-v0
+          paths:
+            - lib/wasi-libc/sysroot
+      - run: go test -v ./cgo ./compileopts ./interp ./transform .
+      - run: make gen-device -j4
+      - run: make smoketest
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - ~/.cache/tinygo
+            - /go/pkg/mod
+      - run: make fmt-check
+  assert-test-linux:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            sudo apt-get install \
+                gcc-arm-linux-gnueabihf \
+                binutils-arm-none-eabi \
+                libc6-dev-armel-cross \
+                gcc-aarch64-linux-gnu \
+                libc6-dev-arm64-cross \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+      - install-node
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - restore_cache:
+          keys:
+            - llvm-build-9-linux-v0-assert
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              sudo apt-get install cmake clang ninja-build
+              # make build faster
+              export CC=clang
+              export CXX=clang++
+              # hack ninja to use less jobs
+              echo -e '#!/bin/sh\n/usr/bin/ninja -j3 "$@"' > /go/bin/ninja
+              chmod +x /go/bin/ninja
+              # build!
+              make ASSERT=1 llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-9-linux-v0-assert
+          paths:
+            llvm-build
+      - run: make ASSERT=1
+      - build-wasi-libc
+      - run:
+          name: "Test TinyGo"
+          command: make ASSERT=1 test
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - ~/.cache/tinygo
+            - /go/pkg/mod
+      - run: make gen-device -j4
+      - run: make smoketest TINYGO=build/tinygo
+  build-linux:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install apt dependencies"
+          command: |
+            sudo apt-get install \
+                gcc-arm-linux-gnueabihf \
+                binutils-arm-none-eabi \
+                libc6-dev-armel-cross \
+                gcc-aarch64-linux-gnu \
+                libc6-dev-arm64-cross \
+                qemu-system-arm \
+                qemu-user \
+                gcc-avr \
+                avr-libc
+      - install-node
+      - restore_cache:
+          keys:
+            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-v2-{{ checksum "go.mod" }}
+      - llvm-source-linux
+      - restore_cache:
+          keys:
+            - llvm-build-9-linux-v0
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              sudo apt-get install cmake clang ninja-build
+              # make build faster
+              export CC=clang
+              export CXX=clang++
+              # hack ninja to use less jobs
+              echo -e '#!/bin/sh\n/usr/bin/ninja -j3 "$@"' > /go/bin/ninja
+              chmod +x /go/bin/ninja
+              # build!
+              make llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-9-linux-v0
+          paths:
+            llvm-build
+      - build-wasi-libc
+      - run:
+          name: "Test TinyGo"
+          command: make test
+      - run:
+          name: "Build TinyGo release"
+          command: |
+            make release -j3
+            cp -p build/release.tar.gz /tmp/tinygo.linux-amd64.tar.gz
+      - store_artifacts:
+          path: /tmp/tinygo.linux-amd64.tar.gz
+      - save_cache:
+          key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - ~/.cache/tinygo
+            - /go/pkg/mod
+      - run:
+          name: "Extract release tarball"
+          command: |
+            mkdir -p ~/lib
+            tar -C ~/lib -xf /tmp/tinygo.linux-amd64.tar.gz
+            ln -s ~/lib/tinygo/bin/tinygo /go/bin/tinygo
+            tinygo version
+      - run: make smoketest
+  build-macos:
+    steps:
+      - checkout
+      - submodules
+      - run:
+          name: "Install dependencies"
+          command: |
+            curl https://dl.google.com/go/go1.13.darwin-amd64.tar.gz -o go1.13.darwin-amd64.tar.gz
+            sudo tar -C /usr/local -xzf go1.13.darwin-amd64.tar.gz
+            ln -s /usr/local/go/bin/go /usr/local/bin/go
+            HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
+      - restore_cache:
+          keys:
+            - go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-macos-v2-{{ checksum "go.mod" }}
+      - restore_cache:
+          keys:
+            - llvm-source-9-macos-v0
+      - run:
+          name: "Fetch LLVM source"
+          command: make llvm-source
+      - save_cache:
+          key: llvm-source-9-macos-v0
+          paths:
+            - llvm-project
+      - restore_cache:
+          keys:
+            - llvm-build-9-macos-v0
+      - run:
+          name: "Build LLVM"
+          command: |
+            if [ ! -f llvm-build/lib/liblldELF.a ]
+            then
+              # install dependencies
+              HOMEBREW_NO_AUTO_UPDATE=1 brew install cmake ninja
+              # build!
+              make llvm-build
+            fi
+      - save_cache:
+          key: llvm-build-9-macos-v0
+          paths:
+            llvm-build
+      - restore_cache:
+          keys:
+            - wasi-libc-sysroot-macos-v0
+      - run:
+          name: "Build wasi-libc"
+          command: make wasi-libc CLANG=$PWD/llvm-build/bin/clang LLVM_AR=$PWD/llvm-build/bin/llvm-ar LLVM_NM=$PWD/llvm-build/bin/llvm-nm
+      - save_cache:
+          key: wasi-libc-sysroot-macos-v0
+          paths:
+            - lib/wasi-libc/sysroot
+      - run:
+          name: "Test TinyGo"
+          command: make test
+      - run:
+          name: "Build TinyGo release"
+          command: |
+            make release -j3
+            cp -p build/release.tar.gz /tmp/tinygo.darwin-amd64.tar.gz
+      - store_artifacts:
+          path: /tmp/tinygo.darwin-amd64.tar.gz
+      - run:
+          name: "Extract release tarball"
+          command: |
+            mkdir -p ~/lib
+            tar -C /usr/local/opt -xf /tmp/tinygo.darwin-amd64.tar.gz
+            ln -s /usr/local/opt/tinygo/bin/tinygo /usr/local/bin/tinygo
+            tinygo version
+      - run:
+          name: "Download SiFive GNU toolchain"
+          command: |
+            curl -O https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.2.0-2019.05.3-x86_64-apple-darwin.tar.gz
+            sudo tar -C /usr/local --strip-components=1 -xf riscv64-unknown-elf-gcc-8.2.0-2019.05.3-x86_64-apple-darwin.tar.gz
+      - run: make smoketest AVR=0
+      - save_cache:
+          key: go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          paths:
+            - ~/.cache/go-build
+            - ~/.cache/tinygo
+            - /go/pkg/mod
+
+
+jobs:
+  test-llvm9-go111:
+    docker:
+      - image: circleci/golang:1.11-stretch
+    steps:
+      - test-linux
+  test-llvm9-go112:
+    docker:
+      - image: circleci/golang:1.12-stretch
+    steps:
+      - test-linux
+  test-llvm9-go113:
+    docker:
+      - image: circleci/golang:1.13-stretch
+    steps:
+      - test-linux
+  assert-test-linux:
+    docker:
+      - image: circleci/golang:1.13-stretch
+    steps:
+      - assert-test-linux
+  build-linux:
+    docker:
+      - image: circleci/golang:1.13-stretch
+    steps:
+      - build-linux
+  build-macos:
+    macos:
+      xcode: "10.1.0"
+    steps:
+      - build-macos
+
+
+
+
+workflows:
+  test-all:
+    jobs:
+      - test-llvm9-go111
+      - test-llvm9-go112
+      - test-llvm9-go113
+      - build-linux
+      - build-macos
+      - assert-test-linux

.gitignore

@@ -5,8 +5,12 @@ src/device/avr/*.ld
 src/device/avr/*.s
 src/device/nrf/*.go
 src/device/nrf/*.s
-src/device/stm32/*.go
-src/device/stm32/*.s
 src/device/sam/*.go
 src/device/sam/*.s
+src/device/sifive/*.go
+src/device/sifive/*.s
+src/device/stm32/*.go
+src/device/stm32/*.s
 vendor
+llvm-build
+llvm-project

.gitmodules

@@ -9,8 +9,11 @@
 	url = https://github.com/avr-rust/avr-mcu.git
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
-	url = https://github.com/posborne/cmsis-svd
+	url = https://github.com/tinygo-org/cmsis-svd
 [submodule "lib/compiler-rt"]
 	path = lib/compiler-rt
 	url = https://github.com/llvm-mirror/compiler-rt.git
-	branch = release_70
+	branch = release_80
+[submodule "lib/wasi-libc"]
+	path = lib/wasi-libc
+	url = https://github.com/CraneStation/wasi-libc

.travis.yml

@@ -1,50 +0,0 @@
-language: go
-
-matrix:
-  include:
-  - dist: xenial
-    go: "1.11"
-
-addons:
-  apt:
-    sources:
-    - sourceline: 'ppa:ubuntu-toolchain-r'
-    - sourceline: 'deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-7 main'
-      key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
-    packages:
-    - llvm-7-dev
-    - clang-7
-    - libclang-7-dev
-    - gcc-arm-linux-gnueabi
-    - binutils-arm-none-eabi
-    - libc6-dev-armel-cross
-    - gcc-aarch64-linux-gnu
-    - libc6-dev-arm64-cross
-    - qemu-system-arm
-    - qemu-user
-    - gcc-avr
-    - avr-libc
-
-install:
-  - curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
-  - dep ensure --vendor-only
-
-script:
-  - go install github.com/tinygo-org/tinygo
-  - go test -v .
-  - make gen-device
-  - tinygo build -size short -o blinky1.nrf.elf    -target=pca10040     examples/blinky1
-  - tinygo build -size short -o blinky2.nrf.elf    -target=pca10040     examples/blinky2
-  - tinygo build -size short -o blinky2                                 examples/blinky2
-  - tinygo build -size short -o test.nrf.elf       -target=pca10040     examples/test
-  - tinygo build -size short -o blinky1.nrf51.elf  -target=microbit     examples/echo
-  - tinygo build -size short -o test.nrf.elf       -target=nrf52840-mdk examples/blinky1
-  - tinygo build -size short -o blinky1.nrf51d.elf -target=pca10031     examples/blinky1
-  - tinygo build -size short -o blinky1.stm32.elf  -target=bluepill     examples/blinky1
-  - tinygo build -size short -o blinky1.avr.elf    -target=arduino      examples/blinky1
-  - tinygo build -size short -o blinky1.avr.elf    -target=digispark    examples/blinky1
-  - tinygo build -size short -o blinky1.reel.elf   -target=reelboard    examples/blinky1
-  - tinygo build -size short -o blinky2.reel.elf   -target=reelboard    examples/blinky2
-  - tinygo build -size short -o blinky1.pca10056.elf    -target=pca10056     examples/blinky1
-  - tinygo build -size short -o blinky2.pca10056.elf    -target=pca10056     examples/blinky2
-  - tinygo build -size short -o blinky1.samd21.elf    -target=itsybitsy-m0     examples/blinky1

BUILDING.md

@@ -2,9 +2,9 @@
 
 TinyGo depends on LLVM and libclang, which are both big C++ libraries. It can
 also optionally use a built-in lld to ease cross compiling. There are two ways
-these can be linked: dynamically and statically. The default is dynamic linking
-because it is fast and works almost out of the box on Debian-based systems with
-the right libraries installed.
+these can be linked: dynamically and statically. An install with `go install` is
+dynamic linking because it is fast and works almost out of the box on
+Debian-based systems with the right packages installed.
 
 This guide describes how to statically link TinyGo against LLVM, libclang and
 lld so that the binary can be easily moved between systems. It also shows how to
@@ -16,83 +16,54 @@ LLVM, Clang and LLD are quite light on dependencies, requiring only standard
 build tools to be built. Go is of course necessary to build TinyGo itself.
 
   * Go (1.11+)
-  * [dep](https://golang.github.io/dep/)
   * Standard build tools (gcc/clang)
-  * git or subversion
+  * git
   * CMake
-  * [Ninja](https://ninja-build.org/) or make (preferably Ninja)
+  * [Ninja](https://ninja-build.org/)
 
 The rest of this guide assumes you're running Linux, but it should be equivalent
 on a different system like Mac.
 
 ## Download the source
 
-The first step is to get the source code. Place it in some directory, assuming
-`$HOME/src` here, but you can pick a different one of course:
+The first step is to download the TinyGo sources (use `--recursive` if you clone
+the git repository). Then, inside the directory, download the LLVM source:
 
-    git clone -b release_70 https://github.com/llvm-mirror/llvm.git $HOME/src/llvm
-    git clone -b release_70 https://github.com/llvm-mirror/clang.git $HOME/src/llvm/tools/clang
-    git clone -b release_70 https://github.com/llvm-mirror/lld.git $HOME/src/llvm/tools/lld
-    go get -d github.com/tinygo-org/tinygo
-    cd $HOME/go/src/github.com/tinygo-org/tinygo
-    dep ensure -vendor-only # download dependencies
+    make llvm-source
 
-Note that Clang and LLD must be placed inside the tools subdirectory of LLVM to
-be automatically built with the rest of the system.
+You can also store LLVM outside of the TinyGo root directory by setting the
+`LLVM_BUILDDIR`, `CLANG_SRC` and `LLD_SRC` make variables, but that is not
+covered by this guide.
+
+TinyGo uses Go modules, so if you clone TinyGo inside your GOPATH (and are using
+Go below 1.13), make sure that Go modules are enabled:
+
+    export GO111MODULE=on
 
 ## Build LLVM, Clang, LLD
 
-Building LLVM is quite easy compared to some other software packages. However,
-the default configuration is _not_ optimized for distribution. It is optimized
-for development, meaning that binaries produce accurate error messages at the
-cost of huge binaries and slow compiles.
-
-Before configuring, you may want to set the following environment variables to
-speed up the build. Most Linux distributions ship with GCC as the default
-compiler, but Clang is significantly faster and uses much less memory while
-producing binaries that are about as fast.
+Before starting the build, you may want to set the following environment
+variables to speed up the build. Most Linux distributions ship with GCC as the
+default compiler, but Clang is significantly faster and uses much less memory
+while producing binaries that are about as fast.
 
     export CC=clang
     export CXX=clang++
 
-Make a build directory. LLVM requires out-of-tree builds:
+The Makefile includes a default configuration that is good for most users. It
+builds a release version of LLVM (optimized, no asserts) and includes all
+targets supported by TinyGo:
 
-    mkdir $HOME/src/llvm-build
-    cd $HOME/src/llvm-build
-
-Configure LLVM with CMake:
-
-    cmake -G Ninja ../llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR;WebAssembly" -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=OFF -DLIBCLANG_BUILD_STATIC=ON
-
-You can also choose a different build system than Ninja, but Ninja is fast.
-
-There are various options you can tune here, but the options given above are
-preferable for releases. Here is what they do:
-
-  * `LLVM_TARGETS_TO_BUILD` and `LLVM_EXPERIMENTAL_TARGETS_TO_BUILD`: the
-    targets that are natively supported by the LLVM code generators. The targets
-    listed here are the ones supported by TinyGo. Note that LLVM is a cross
-    compiler by default, unlike some other compilers.
-  * `CMAKE_BUILD_TYPE`: the default is Debug, which produces large inefficient
-    binaries that are easy to debug. We want small and fast binaries.
-  * `LLVM_ENABLE_ASSERTIONS`: the default is ON, which greatly slows down LLVM
-    and is only really useful during development. Disable them here.
-  * `LIBCLANG_BUILD_STATIC`: unlike LLVM, libclang is built as a shared library
-    by default. We want a static library for easy distribution.
-
-Now build it:
-
-    ninja # or make, if you choose make in the previous step
+    make llvm-build
 
 This can take over an hour depending on the speed of your system.
 
 ## Build TinyGo
 
-Now that you have a working version of LLVM, build TinyGo using it. You need to
-specify the directories to the LLVM build directory and to the Clang and LLD source.
+The last step of course is to build TinyGo itself. This can again be done with
+make:
 
-    cd $HOME/go/src/github.com/tinygo-org/tinygo
-    make static LLVM_BUILDDIR=$HOME/src/llvm-build CLANG_SRC=$HOME/src/llvm/tools/clang LLD_SRC=$HOME/src/llvm/tools/lld
+    make
 
 ## Verify TinyGo
 
@@ -109,14 +80,12 @@ The result should not contain libclang or libLLVM.
 
 ## Make a release tarball
 
-Now that we have a working static build, it's time to make a release tarball.
-This is just a slight change from the command to build TinyGo:
+Now that we have a working static build, it's time to make a release tarball:
 
-    cd $HOME/go/src/github.com/tinygo-org/tinygo
-    make release LLVM_BUILDDIR=$HOME/src/llvm-build CLANG_SRC=$HOME/src/llvm/tools/clang LLD_SRC=$HOME/src/llvm/tools/lld
+    make release
 
 The release tarball is stored in build/release.tar.gz, and can be extracted with
-the following command:
+the following command (for example in ~/lib):
 
     tar -xvf path/to/release.tar.gz
 

CHANGELOG.md

@@ -1,3 +1,415 @@
+0.12.0
+---
+* **command line**
+  - add initial FreeBSD support
+  - remove getting a serial port in gdb subcommand
+  - add support for debugging through JLinkGDBServer
+  - fix CGo when cross compiling
+  - remove default port check for Digispark as micronucleus communicates directly using HID
+  - differentiate between various serial/USB error messages
+* **builder**
+  - improve detection of Clang headers
+* **compiler**
+  - fix assertion on empty interface
+  - don't crash when encountering `types.Invalid`
+  - revise defer to use heap allocations when running a variable number of times
+  - improve error messages for failed imports
+  - improve "function redeclared" error
+  - add globaldce pass to start of optimization pipeline
+  - add support for debugging globals
+  - implement RISC-V CSR operations as intrinsics
+  - add support for CGO_ENABLED environment variable
+  - do not emit debug info for extern globals (bugfix)
+  - add support for interrupts
+  - implement maps for arbitrary keys
+  - interp: error location for "unknown GEP" error
+  - wasm-abi: create temporary allocas in the entry block
+* **cgo**
+  - add support for symbols in `#define`
+  - fix a bug in number tokenization
+* **standard library**
+  - `machine`: avoid bytes package in USB logic
+  - `runtime`: fix external address declarations
+  - `runtime`: provide implementation for `internal/bytealg.IndexByte`
+* **targets**
+  - `atsamd51`: fix volatile usage
+  - `atsamd51`: fix ADC, updating to 12-bits precision
+  - `atsamd51`: refactor SPI pin configuration to only look at pin numbers
+  - `atsamd51`: switch UART to use new pin configuration
+  - `atsamd51`: fix obvious bug in I2C code
+  - `atsamd51`: use only the necessary UART interrupts
+  - `atsamd51`: refactor I2C pin handling to auto-detect pin mode
+  - `avr`: use a garbage collector
+  - `fe310`: use CLINT peripheral for timekeeping
+  - `fe310`: add support for PLIC interrupts
+  - `fe310`: implement UART receive interrupts
+  - `riscv`: support sleeping in QEMU
+  - `riscv`: add bare-bones interrupt support
+  - `riscv`: print exception PC and code
+  - `wasm`: implement memcpy and memset
+  - `wasm`: include wasi-libc
+  - `wasm`: use wasi ABI for basic startup/stdout
+* **boards**
+  - `arduino`: make avrdude command line compatible with Windows
+  - `arduino-nano`: add this board
+  - `arduino-nano33`: fix UART1 and UART2
+  - `circuitplay-bluefruit`: add this board
+  - `digispark`: add clock speed and pin mappings
+  - `gameboy-advance`: include compiler-rt in build
+  - `gameboy-advance`: implement interrupt handler
+  - `hifive1b`: add support for gdb subcommand
+  - `pyportal`: add this board
+  - `pyportal`: remove manual SPI pin mapping as now handled by default
+
+
+0.11.0
+---
+* **command line**
+  - add support for QEMU in `gdb` subcommand
+  - use builtin Clang when building statically, dropping the clang-9 dependency
+  - search for default serial port on both macOS and Linux
+  - windows: support `tinygo flash` directly by using win32 wmi
+* **compiler**
+  - add location information to the IR checker
+  - make reflection sidetables constant globals
+  - improve error locations in goroutine lowering
+  - interp: improve support for maps with string keys
+  - interp: add runtime fallback for mapassign operations
+* **standard library**
+  - `machine`: add support for `SPI.Tx()` on play.tinygo.org
+  - `machine`: rename `CPU_FREQUENCY` to `CPUFrequency()`
+* **targets**
+  - `adafruit-pybadge`: add Adafruit Pybadge
+  - `arduino-nano33`: allow simulation on play.tinygo.org
+  - `arduino-nano33`: fix default SPI pin numbers to be D13/D11/D12
+  - `circuitplay-express`: allow simulation on play.tinygo.org
+  - `hifive1-qemu`: add target for testing RISC-V bare metal in QEMU
+  - `riscv`: fix heap corruption due to changes in LLVM 9
+  - `riscv`: add support for compiler-rt
+  - `qemu`: rename to `cortex-m-qemu`
+
+0.10.0
+---
+* **command line**
+  - halt GDB after flashing with `gdb` subcommand
+  - fix a crash when using `-ocd-output`
+  - add `info` subcommand
+  - add `-programmer` flag
+* **builder**
+  - macos: use llvm@8 instead of just llvm in paths
+  - add `linkerscript` key to target JSON files
+  - write a symbol table when writing out the compiler-rt lib
+  - make Clang header detection more robust
+  - switch to LLVM 9
+* **compiler**
+  - fix interface miscompilation with reflect
+  - fix miscompile of static goroutine calls to closures
+  - fix `todo: store` panic
+  - fix incorrect starting value for optimized allocations in a loop
+  - optimize coroutines on non-Cortex-M targets
+  - fix crash for programs which have heap allocations but never hit the GC
+  - add support for async interface calls
+  - fix inserting non-const values in a const global
+  - interp: improve error reporting
+  - interp: implement comparing ptrtoint to 0
+* **cgo**
+  - improve diagnostics
+  - implement the constant parser (for `#define`) as a real parser
+  - rename reserved field names such as `type`
+  - avoid `"unsafe" imported but not used` error
+  - include all enums in the CGo Go AST
+  - add support for nested structs and unions
+  - implement `#cgo CFLAGS`
+* **standard library**
+  - `reflect`: add implementation of array alignment
+  - `runtime`: improve scheduler performance when no goroutines are queued
+  - `runtime`: add blocking select
+  - `runtime`: implement interface equality in non-trivial cases
+  - `runtime`: add AdjustTimeOffset to update current time
+  - `runtime`: only implement CountString for required platforms
+  - `runtime`: use MSP/PSP registers for scheduling on Cortex-M
+* **targets**
+  - `arm`: add system timer registers
+  - `atmega`: add port C GPIO support
+  - `atsamd21`: correct handling of pins >= 32
+  - `atsamd21`: i2s initialization fixes
+  - `atsamd51`: fix clock init code
+  - `atsamd51`: correct initialization for RTC
+  - `atsamd51`: fix pin function selection
+  - `atsamd51`: pin method cleanup
+  - `atsamd51`: allow setting pin mode for each of the SPI pins
+  - `atsamd51`: correct channel init and pin map for ADC based on ItsyBitsy-M4
+  - `feather-m4`: add Adafruit Feather M4 board
+  - `hifive1b`: add support for SPI1
+  - `hifive1b`: fix compiling in simulation
+  - `linux`: fix time on arm32
+  - `metro-m4`: add support for Adafruit Metro M4 Express Airlift board
+  - `metro-m4`: fixes for UART2
+  - `pinetime-devkit0`: add support for the PineTime dev kit
+  - `x9pro`: add support for this smartwatch
+  - `pca10040-s132v6`: add support for SoftDevice
+  - `pca10056-s140v7`: add support for SoftDevice
+  - `arduino-nano33`: added SPI1 connected to NINA-W102 chip on Arduino Nano 33 IOT
+
+0.9.0
+---
+* **command line**
+  - implement 1200-baud UART bootloader reset when flashing boards that support
+    it
+  - flash using mass-storage device for boards that support it
+  - implement `tinygo env`
+  - add support for Windows (but not yet producing Windows binaries)
+  - add Go version to `tinygo env`
+  - update SVD files for up-to-date peripheral interfaces
+* **compiler**
+  - add `//go:align` pragma
+  - fix bug related to type aliases
+  - add support for buffered channels
+  - remove incorrect reflect optimization
+  - implement copying slices in init interpretation
+  - add support for constant indices with a named type
+  - add support for recursive types like linked lists
+  - fix miscompile of function nil panics
+  - fix bug related to goroutines
+* **standard library**
+  - `machine`: do not check for nil slices in `SPI.Tx`
+  - `reflectlite`: add support for Go 1.13
+  - `runtime`: implement `internal/bytealg.CountString`
+  - `sync`: properly handle nil `New` func in `sync.Pool`
+* **targets**
+  - `arduino`: fix .bss section initialization
+  - `fe310`: implement `Pin.Get`
+  - `gameboy-advance`: support directly outputting .gba files
+  - `samd`: reduce code size by avoiding reflection
+  - `samd21`: do not hardcode pin numbers for peripherals
+  - `stm32f103`: avoid issue with `time.Sleep` less than 200µs
+
+0.8.0
+---
+* **command line**
+  - fix parsing of beta Go versions
+  - check the major/minor installed version of Go before compiling
+  - validate `-target` flag better to not panic on an invalid target
+* **compiler**
+  - implement full slice expression: `s[:2:4]`
+  - fix a crash when storing a linked list in an interface
+  - fix comparing struct types by making type IDs more unique
+  - fix some bugs in IR generation
+  - add support for linked lists in reflect data
+  - implement `[]rune` to string conversion
+  - implement support for `go` on func values
+* **standard library**
+  - `reflect`: add support for named types
+  - `reflect`: add support for `t.Bits()`
+  - `reflect`: add basic support for `t.AssignableTo()`
+  - `reflect`: implement `t.Align()`
+  - `reflect`: add support for struct types
+  - `reflect`: fix bug in `v.IsNil` and `v.Pointer` for addressable values
+  - `reflect`: implement support for array types
+  - `reflect`: implement `t.Comparable()`
+  - `runtime`: implement stack-based scheduler
+  - `runtime`: fix bug in the sleep queue of the scheduler
+  - `runtime`: implement `memcpy` for Cortex-M
+  - `testing`: implement stub `testing.B` struct
+  - `testing`: add common test logging methods such as Errorf/Fatalf/Printf
+* **targets**
+  - `386`: add support for linux/386 syscalls
+  - `atsamd21`: make SPI pins configurable so that multiple SPI ports can be
+    used
+  - `atsamd21`: correct issue with invalid first reading coming from ADC
+  - `atsamd21`: add support for reset-to-bootloader using 1200baud over USB-CDC
+  - `atsamd21`: make pin selection more flexible for peripherals
+  - `atsamd21`: fix minimum delay in `time.Sleep`
+  - `atsamd51`: fix minimum delay in `time.Sleep`
+  - `nrf`: improve SPI write-only speed, by making use of double buffering
+  - `stm32f103`: fix SPI frequency selection
+  - `stm32f103`: add machine.Pin.Get method for reading GPIO values
+  - `stm32f103`: allow board specific UART usage
+  - `nucleo-f103rb`: add support for NUCLEO-F103RB board
+  - `itsybitsy-m4`: add support for this board with a SAMD51 family chip
+  - `cortex-m`: add support for `arm.SystemReset()`
+  - `gameboy-advance`: add initial support for the GameBoy Advance
+  - `wasm`: add `//go:wasm-module` magic comment to set the wasm module name
+  - `wasm`: add syscall/js.valueSetIndex support
+  - `wasm`: add syscall/js.valueInvoke support
+
+0.7.1
+---
+* **targets**
+  - `atsamd21`: add support for the `-port` flag in the flash subcommand
+
+0.7.0
+---
+* **command line**
+  - try more locations to find Clang built-in headers
+  - add support for `tinygo test`
+  - build current directory if no package is specified
+  - support custom .json target spec with `-target` flag
+  - use zversion.go to detect version of GOROOT version
+  - make initial heap size configurable for some targets (currently WebAssembly
+    only)
+* **cgo**
+  - add support for bitfields using generated getters and setters
+  - add support for anonymous structs
+* **compiler**
+  - show an error instead of panicking on duplicate function definitions
+  - allow packages like github.com/tinygo-org/tinygo/src/\* by aliasing it
+  - remove `//go:volatile` support  
+    It has been replaced with the runtime/volatile package.
+  - allow poiners in map keys
+  - support non-constant syscall numbers
+  - implement non-blocking selects
+  - add support for the `-tags` flag
+  - add support for `string` to `[]rune` conversion
+  - implement a portable conservative garbage collector (with support for wasm)
+  - add the `//go:noinline` pragma
+* **standard library**
+  - `os`: add `os.Exit` and `syscall.Exit`
+  - `os`: add several stubs
+  - `runtime`: fix heap corruption in conservative GC
+  - `runtime`: add support for math intrinsics where supported, massively
+    speeding up some benchmarks
+  - `testing`: add basic support for testing
+* **targets**
+  - add support for a generic target that calls `__tinygo_*` functions for
+    peripheral access
+  - `arduino-nano33`: add support for this board
+  - `hifive1`: add support for this RISC-V board
+  - `reelboard`: add e-paper pins
+  - `reelboard`: add `PowerSupplyActive` to enable voltage for on-board devices
+  - `wasm`: put the stack at the start of linear memory, to detect stack
+    overflows
+
+0.6.0
+---
+* **command line**
+  - some portability improvements
+  - make `$GOROOT` more robust and configurable
+  - check for Clang at the Homebrew install location as fallback
+* **compiler driver**
+  - support multiple variations of LLVM commands, for non-Debian distributions
+* **compiler**
+  - improve code quality in multiple ways
+  - make panic configurable, adding trap on panic
+  - refactor many internal parts of the compiler
+  - print all errors encountered during compilation
+  - implement calling function values of a named type
+  - implement returning values from blocking functions
+  - allow larger-than-int values to be sent across a channel
+  - implement complex arithmetic
+  - improve hashmap support
+  - add debuginfo for function arguments
+  - insert nil checks on stores (increasing code size)
+  - implement volatile operations as compiler builtins
+  - add `//go:inline` pragma
+  - add build tags for the Go stdlib version
+* **cgo**
+  - implement `char`, `enum` and `void*` types
+  - support `#include` for builtin headers
+  - improve typedef/struct/enum support
+  - only include symbols that are necessary, for broader support
+  - mark external function args as `nocapture`
+  - implement support for some `#define` constants
+  - implement support for multiple CGo files in a single package
+- **standard library**
+  - `machine`: remove microbit matrix (moved to drivers repository)
+  - `machine`: refactor pins to use `Pin` type instead of `GPIO`
+  - `runtime`: print more interface types on panic, including `error`
+* **targets**
+  - `arm`: print an error on HardFault (including stack overflows)
+  - `atsamd21`: fix a bug in the ADC peripheral
+  - `atsamd21`: add support for I2S
+  - `feather-m0`: add support for this board
+  - `nrf51`: fix a bug in I2C
+  - `stm32f103xx`: fix a bug in I2C
+  - `syscall`: implement `Exit` on unix
+  - `trinket-m0`: add support for this board
+  - `wasm`: make _main_ example smaller
+  - `wasm`: don't cache wasm file in the server, for ease of debugging
+  - `wasm`: work around bug #41508 that caused a deadlock while linking
+  - `wasm`: add support for `js.FuncOf`
+
+0.5.0
+---
+- **compiler driver**
+  - use `wasm-ld` instead of `wasm-ld-8` on macOS
+  - drop dependency on `llvm-ar`
+  - fix linker script includes when running outside `TINYGOROOT`
+- **compiler**
+  - switch to LLVM 8
+  - add support for the Go 1.12 standard library (Go 1.11 is still supported)
+  - work around lack of escape analysis due to nil checks
+  - implement casting named structs and pointers to them
+  - fix int casting to use the source signedness
+  - fix some bugs around `make([]T, …)` with uncommon index types
+  - some other optimizations
+  - support interface asserts in interp for "math/rand" support
+  - resolve all func value targets at compile time (wasm-only at the moment)
+- **cgo**
+  - improve diagnostics
+  - implement C `struct`, `union`, and arrays
+  - fix CGo-related crash in libclang
+  - implement `C.struct_` types
+- **targets**
+  - all baremetal: pretend to be linux/arm instead of js/wasm
+  - `avr`: improve `uintptr` support
+  - `cortexm`: implement memmove intrinsic generated by LLVM
+  - `cortexm`: use the lld linker instead of `arm-none-eabi-ld`
+  - `darwin`: use custom syscall package that links to libSystem.dylib
+  - `microbit`: add blink example
+  - `samd21`: support I2C1
+  - `samd21`: machine/atsamd21: correct pad/pin handling when using both UART
+     and USBCDC interfaces at same time
+  - `stm32f4discovery`: add support for this board
+  - `wasm`: support async func values
+  - `wasm`: improve documentation and add extra example
+
+0.4.1
+---
+- **compiler**
+  - fix `objcopy` replacement to include the .data section in the firmware image
+  - use `llvm-ar-7` on Linux to fix the Docker image
+
+0.4.0
+---
+- **compiler**
+  - switch to the hardfloat ABI on ARM, which is more widely used
+  - avoid a dependency on `objcopy` (`arm-none-eabi-objcopy` etc.)
+  - fix a bug in `make([]T, n)` where `n` is 64-bits on a 32-bit platform
+  - adapt to a change in the AVR backend in LLVM 8
+  - directly support the .uf2 firmware format as used on Adafruit boards
+  - fix a bug when calling `panic()` at init time outside of the main package
+  - implement nil checks, which results in a ~5% increase in code size
+  - inline slice bounds checking, which results in a ~1% decrease in code size
+- **targets**
+  - `samd21`: fix a bug in port B pins
+  - `samd21`: implement SPI peripheral
+  - `samd21`: implement ADC peripheral
+  - `stm32`: fix a bug in timekeeping
+  - `wasm`: fix a bug in `wasm_exec.js` that caused corruption in linear memory
+     when running on Node.js.
+
+0.3.0
+---
+- **compiler**
+  - remove old `-initinterp` flag
+  - add support for macOS
+- **cgo**
+  - add support for bool/float/complex types
+- **standard library**
+  - `device/arm`: add support to disable/enable hardware interrupts
+  - `machine`: add CPU frequency for nrf-based boards
+  - `syscall`: add support for darwin/amd64
+- **targets**
+  - `circuitplay_express`: add support for this board
+  - `microbit`: add regular pin constants
+  - `samd21`: fix time function for goroutine support
+  - `samd21`: add support for USB-CDC (serial over USB)
+  - `samd21`: add support for pins in port B
+  - `samd21`: add support for pullup and pulldown pins
+  - `wasm`: add support for Safari in example
+
+
 0.2.0
 ---
 - **command line**

CODE-OF-CONDUCT.md

@@ -0,0 +1,76 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to make participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies within all project spaces, and it also applies when
+an individual is representing the project or its community in public spaces.
+Examples of representing a project or community include using an official
+project e-mail address, posting via an official social media account, or acting
+as an appointed representative at an online or offline event. Representation of
+a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at [conduct@tinygo.org](mailto:conduct@tinygo.org). All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

CONTRIBUTING.md

@@ -16,12 +16,16 @@ Please open a Github issue with your problem, and we will be happy to assist.
 
 We probably have not implemented it yet. Please take a look at our [Roadmap](https://github.com/tinygo-org/tinygo/wiki/Roadmap). Your pull request adding the functionality to TinyGo would be greatly appreciated.
 
+Please open a Github issue. We want to help, and also make sure that there is no duplications of efforts. Sometimes what you need is already being worked on by someone else.
+
 A long tail of small (and large) language features haven't been implemented yet. In almost all cases, the compiler will show a `todo:` error from `compiler/compiler.go` when you try to use it. You can try implementing it, or open a bug report with a small code sample that fails to compile.
 
 ### Some specific hardware you want to use does not appear to be in TinyGo
 
 As above, we probably have not implemented it yet. Your contribution adding the hardware support to TinyGo would be greatly appreciated.
 
+Please start by opening a Github issue. We want to help you to help us to help you.
+
 Lots of targets/boards are still unsupported. Adding an architecture often requires a few compiler changes, but if the architecture is supported you can try implementing support for a new chip or board in `src/runtime`. For details, see [this wiki entry on adding archs/chips/boards](https://github.com/tinygo-org/tinygo/wiki/Adding-a-new-board).
 
 Microcontrollers have lots of peripherals (I2C, SPI, ADC, etc.) and many don't have an implementation yet in the `machine` package. Adding support for new peripherals is very useful.

CONTRIBUTORS

@@ -0,0 +1,18 @@
+# This is the official list of TinyGo authors for copyright purposes.
+#
+# This file is not actively maintained.
+# To be included, send a change adding the individual or
+# company who owns a contribution's copyright.
+#
+# Names should be added to this file as one of
+#     Organization's name
+#     Individual's name <submission email address>
+#     Individual's name <submission email address> <email2> <emailN>
+#
+# Please keep the list sorted.
+
+Ayke van Laethem <aykevanlaethem@gmail.com>
+Daniel Esteban <conejo@conejo.me>
+Loon, LLC.
+Ron Evans <ron@hybridgroup.com>
+Jaden Weiss <jaden@jadendw.dev>

Dockerfile

@@ -1,49 +1,48 @@
-# TinyGo base stage just installs LLVM 7 and the TinyGo compiler itself.
-FROM golang:latest AS tinygo-base
+# TinyGo base stage installs Go 1.13, LLVM 9 and the TinyGo compiler itself.
+FROM golang:1.13 AS tinygo-base
 
 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
-    echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-7 main" >> /etc/apt/sources.list && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-9 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y llvm-7-dev libclang-7-dev git
+    apt-get install -y llvm-9-dev libclang-9-dev git
 
-RUN wget -O- https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+COPY . /tinygo
 
-COPY . /go/src/github.com/tinygo-org/tinygo
+# remove submodules directories and re-init them to fix any hard-coded paths
+# after copying the tinygo directory in the previous step.
+RUN cd /tinygo/ && \
+    rm -rf ./lib/* && \
+    git submodule update --init --recursive --force
 
-RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
-    git submodule update --init
-
-RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
-    dep ensure --vendor-only && \
-    go install /go/src/github.com/tinygo-org/tinygo/
+RUN cd /tinygo/ && \
+    go install /tinygo/
 
 # tinygo-wasm stage installs the needed dependencies to compile TinyGo programs for WASM.
 FROM tinygo-base AS tinygo-wasm
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/src /go/src/github.com/tinygo-org/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/targets /go/src/github.com/tinygo-org/tinygo/targets
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
 
 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
-    echo "deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-7 main" >> /etc/apt/sources.list && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-9 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y libllvm7 lld-7
+    apt-get install -y libllvm9 lld-9
 
 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
 FROM tinygo-base AS tinygo-avr
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/src /go/src/github.com/tinygo-org/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/targets /go/src/github.com/tinygo-org/tinygo/targets
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/Makefile /go/src/github.com/tinygo-org/tinygo/
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/tools /go/src/github.com/tinygo-org/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/lib /go/src/github.com/tinygo-org/tinygo/lib
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-avr gcc-avr avr-libc && \
+    apt-get install -y apt-utils make binutils-avr gcc-avr avr-libc && \
     make gen-device-avr && \
-    apt-get remove -y python3 make && \
     apt-get autoremove -y && \
     apt-get clean
 
@@ -51,33 +50,27 @@ RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
 FROM tinygo-base AS tinygo-arm
 
 COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/src /go/src/github.com/tinygo-org/tinygo/src
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/targets /go/src/github.com/tinygo-org/tinygo/targets
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/Makefile /go/src/github.com/tinygo-org/tinygo/
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/tools /go/src/github.com/tinygo-org/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/lib /go/src/github.com/tinygo-org/tinygo/lib
+COPY --from=tinygo-base /tinygo/src /tinygo/src
+COPY --from=tinygo-base /tinygo/targets /tinygo/targets
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-arm-none-eabi clang-7 && \
-    make gen-device-nrf && make gen-device-stm32 && \
-    apt-get remove -y python3 make && \
-    apt-get autoremove -y && \
-    apt-get clean
+    apt-get install -y apt-utils make clang-9 && \
+    make gen-device-nrf && make gen-device-stm32
 
 # tinygo-all stage installs the needed dependencies to compile TinyGo programs for all platforms.
 FROM tinygo-wasm AS tinygo-all
 
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/Makefile /go/src/github.com/tinygo-org/tinygo/
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/tools /go/src/github.com/tinygo-org/tinygo/tools
-COPY --from=tinygo-base /go/src/github.com/tinygo-org/tinygo/lib /go/src/github.com/tinygo-org/tinygo/lib
+COPY --from=tinygo-base /tinygo/Makefile /tinygo/
+COPY --from=tinygo-base /tinygo/tools /tinygo/tools
+COPY --from=tinygo-base /tinygo/lib /tinygo/lib
 
-RUN cd /go/src/github.com/tinygo-org/tinygo/ && \
+RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y apt-utils python3 make binutils-arm-none-eabi clang-7 binutils-avr gcc-avr avr-libc && \
-    make gen-device && \
-    apt-get remove -y python3 make && \
-    apt-get autoremove -y && \
-    apt-get clean
+    apt-get install -y apt-utils make clang-9 binutils-avr gcc-avr avr-libc && \
+    make gen-device
 
 CMD ["tinygo"]

Gopkg.lock

@@ -1,33 +0,0 @@
-# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
-
-
-[[projects]]
-  branch = "master"
-  digest = "1:ba70784a3deee74c0ca3c87bcac3c2f93d3b2d27d8f237b768c358b45ba47da8"
-  name = "golang.org/x/tools"
-  packages = [
-    "go/ast/astutil",
-    "go/ssa",
-    "go/types/typeutil",
-  ]
-  pruneopts = "UT"
-  revision = "40960b6deb8ecdb8bcde6a8f44722731939b8ddc"
-
-[[projects]]
-  branch = "master"
-  digest = "1:3611159788efdd4e0cfae18b6ebcccbad25a2815968b0e4323b42647d201031a"
-  name = "tinygo.org/x/go-llvm"
-  packages = ["."]
-  pruneopts = "UT"
-  revision = "f420620d1a0f54417a5712260153fe861780d030"
-
-[solve-meta]
-  analyzer-name = "dep"
-  analyzer-version = 1
-  input-imports = [
-    "golang.org/x/tools/go/ast/astutil",
-    "golang.org/x/tools/go/ssa",
-    "tinygo.org/x/go-llvm",
-  ]
-  solver-name = "gps-cdcl"
-  solver-version = 1

Gopkg.toml

@@ -1,11 +0,0 @@
-[[constraint]]
-  branch = "master"
-  name = "tinygo.org/x/go-llvm"
-
-[[constraint]]
-  branch = "master"
-  name = "golang.org/x/tools"
-
-[prune]
-  go-tests = true
-  unused-packages = true

LICENSE

@@ -1,4 +1,10 @@
-Copyright (c) 2018 Ayke van Laethem. All rights reserved.
+Copyright (c) 2018-2019 TinyGo Authors. All rights reserved.
+
+TinyGo includes portions of the Go standard library.
+Copyright (c) 2009-2019 The Go Authors. All rights reserved.
+
+TinyGo includes portions of LLVM, which is under the Apache License v2.0 with
+LLVM Exceptions. See https://llvm.org/LICENSE.txt for license information.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are

Makefile

@@ -1,150 +1,305 @@
 
 # aliases
 all: tinygo
-tinygo: build/tinygo
 
-.PHONY: all tinygo static run-test run-blinky run-blinky2 clean fmt gen-device gen-device-nrf gen-device-avr
+# Default build and source directories, as created by `make llvm-build`.
+LLVM_BUILDDIR ?= llvm-build
+CLANG_SRC ?= llvm-project/clang
+LLD_SRC ?= llvm-project/lld
 
-TARGET ?= unix
+# Default tool selection.
+CLANG ?= clang-9
+LLVM_AR ?= llvm-ar-9
+LLVM_NM ?= llvm-nm-9
 
-ifeq ($(TARGET),unix)
-# Regular *nix system.
+# Go binary and GOROOT to select
+GO ?= go
+export GOROOT = $(shell $(GO) env GOROOT)
 
-else ifeq ($(TARGET),pca10040)
-# PCA10040: nRF52832 development board
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
+# md5sum binary
+MD5SUM = md5sum
 
-else ifeq ($(TARGET),microbit)
-# BBC micro:bit
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else ifeq ($(TARGET),reelboard)
-# reel board
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else ifeq ($(TARGET),bluepill)
-# "blue pill" development board
-# See: https://wiki.stm32duino.com/index.php?title=Blue_Pill
-OBJCOPY = arm-none-eabi-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else ifeq ($(TARGET),arduino)
-OBJCOPY = avr-objcopy
-TGOFLAGS += -target $(TARGET)
-
-else
-$(error Unknown target)
+# tinygo binary for tests
+TINYGO ?= tinygo
 
+# Use CCACHE for LLVM if possible
+ifneq (, $(shell which ccache))
+    LLVM_OPTION += '-DLLVM_CCACHE_BUILD=ON'
 endif
 
-LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines debuginfodwarf executionengine instrumentation interpreter ipo irreader linker lto mc mcjit objcarcopts option profiledata scalaropts support target
+# Allow enabling LLVM assertions
+ifeq (1, $(ASSERT))
+    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=ON'
+else
+    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=OFF'
+endif
 
-CLANG_LIBS = -Wl,--start-group $(abspath $(LLVM_BUILDDIR))/lib/libclang.a -lclangAnalysis -lclangARCMigrate -lclangAST -lclangASTMatchers -lclangBasic -lclangCodeGen -lclangCrossTU -lclangDriver -lclangDynamicASTMatchers -lclangEdit -lclangFormat -lclangFrontend -lclangFrontendTool -lclangHandleCXX -lclangHandleLLVM -lclangIndex -lclangLex -lclangParse -lclangRewrite -lclangRewriteFrontend -lclangSema -lclangSerialization -lclangStaticAnalyzerCheckers -lclangStaticAnalyzerCore -lclangStaticAnalyzerFrontend -lclangTooling -lclangToolingASTDiff -lclangToolingCore -lclangToolingInclusions -lclangToolingRefactor -Wl,--end-group -lstdc++
+.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-avr
 
-LLD_LIBS = -Wl,--start-group -llldCOFF -llldCommon -llldCore -llldDriver -llldELF -llldMachO -llldMinGW -llldReaderWriter -llldWasm -llldYAML -Wl,--end-group
+LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines coverage debuginfodwarf executionengine instrumentation interpreter ipo irreader linker lto mc mcjit objcarcopts option profiledata scalaropts support target
+
+ifeq ($(OS),Windows_NT)
+    EXE = .exe
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
+
+    # LLVM compiled using MinGW on Windows appears to have problems with threads.
+    # Without this flag, linking results in errors like these:
+    #     libLLVMSupport.a(Threading.cpp.obj):Threading.cpp:(.text+0x55): undefined reference to `std::thread::hardware_concurrency()'
+    LLVM_OPTION += -DLLVM_ENABLE_THREADS=OFF
+
+    CGO_LDFLAGS += -static -static-libgcc -static-libstdc++
+    CGO_LDFLAGS_EXTRA += -lversion
+
+    # Build libclang manually because the CMake-based build system on Windows
+    # doesn't allow building libclang as a static library.
+    LIBCLANG_PATH = $(abspath build/libclang-custom.a)
+    LIBCLANG_FILES = $(abspath $(wildcard $(LLVM_BUILDDIR)/tools/clang/tools/libclang/CMakeFiles/libclang.dir/*.cpp.obj))
+
+    # Add the libclang dependency to the tinygo binary target.
+tinygo: $(LIBCLANG_PATH)
+test: $(LIBCLANG_PATH)
+    # Build libclang.
+$(LIBCLANG_PATH): $(LIBCLANG_FILES)
+	@mkdir -p build
+	ar rcs $(LIBCLANG_PATH) $^
+
+else ifeq ($(shell uname -s),Darwin)
+    MD5SUM = md5
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+else ifeq ($(shell uname -s),FreeBSD)
+    MD5SUM = md5
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
+else
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+    START_GROUP = -Wl,--start-group
+    END_GROUP = -Wl,--end-group
+endif
+
+CLANG_LIBS = $(START_GROUP) -lclangAnalysis -lclangARCMigrate -lclangAST -lclangASTMatchers -lclangBasic -lclangCodeGen -lclangCrossTU -lclangDriver -lclangDynamicASTMatchers -lclangEdit -lclangFormat -lclangFrontend -lclangFrontendTool -lclangHandleCXX -lclangHandleLLVM -lclangIndex -lclangLex -lclangParse -lclangRewrite -lclangRewriteFrontend -lclangSema -lclangSerialization -lclangStaticAnalyzerCheckers -lclangStaticAnalyzerCore -lclangStaticAnalyzerFrontend -lclangTooling -lclangToolingASTDiff -lclangToolingCore -lclangToolingInclusions $(END_GROUP) -lstdc++
+
+LLD_LIBS = $(START_GROUP) -llldCOFF -llldCommon -llldCore -llldDriver -llldELF -llldMachO -llldMinGW -llldReaderWriter -llldWasm -llldYAML $(END_GROUP)
 
 
 # For static linking.
-CGO_CPPFLAGS=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
-CGO_CXXFLAGS=-std=c++11
-CGO_LDFLAGS=-L$(LLVM_BUILDDIR)/lib $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS))
-
-
-
-run-test: build/test
-	./build/test
-
-run-blinky: run-blinky2
-run-blinky2: build/blinky2
-	./build/blinky2
-
-ifeq ($(TARGET),pca10040)
-flash-%: build/%.hex
-	nrfjprog -f nrf52 --sectorerase --program $< --reset
-else ifeq ($(TARGET),microbit)
-flash-%: build/%.hex
-	openocd -f interface/cmsis-dap.cfg -f target/nrf51.cfg -c 'program $< reset exit'
-else ifeq ($(TARGET),reelboard)
-flash-%: build/%.hex
-	openocd -f interface/cmsis-dap.cfg -f target/nrf51.cfg -c 'program $< reset exit'
-else ifeq ($(TARGET),arduino)
-flash-%: build/%.hex
-	avrdude -c arduino -p atmega328p -P /dev/ttyACM0 -U flash:w:$<
-else ifeq ($(TARGET),bluepill)
-flash-%: build/%.hex
-	openocd -f interface/stlink-v2.cfg -f target/stm32f1x.cfg -c 'program $< reset exit'
+ifneq ("$(wildcard $(LLVM_BUILDDIR)/bin/llvm-config*)","")
+    CGO_CPPFLAGS=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
+    CGO_CXXFLAGS=-std=c++11
+    CGO_LDFLAGS+=$(LIBCLANG_PATH) -std=c++11 -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
 endif
 
+
 clean:
 	@rm -rf build
 
+FMT_PATHS = ./*.go builder cgo compiler interp ir loader src/device/arm src/examples src/machine src/os src/reflect src/runtime src/sync src/syscall src/internal/reflectlite transform
 fmt:
-	@go fmt . ./compiler ./interp ./loader ./ir ./src/device/arm ./src/examples/* ./src/machine ./src/os ./src/runtime ./src/sync
-	@go fmt ./testdata/*.go
+	@gofmt -l -w $(FMT_PATHS)
+fmt-check:
+	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
 
-test:
-	@go test -v .
 
-gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-stm32
+gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32
 
 gen-device-avr:
-	./tools/gen-device-avr.py lib/avr/packs/atmega src/device/avr/
-	./tools/gen-device-avr.py lib/avr/packs/tiny src/device/avr/
-	go fmt ./src/device/avr
+	$(GO) build -o ./build/gen-device-avr ./tools/gen-device-avr/
+	./build/gen-device-avr lib/avr/packs/atmega src/device/avr/
+	./build/gen-device-avr lib/avr/packs/tiny src/device/avr/
+	@GO111MODULE=off $(GO) fmt ./src/device/avr
 
-gen-device-nrf:
-	./tools/gen-device-svd.py lib/nrfx/mdk/ src/device/nrf/ --source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk
-	go fmt ./src/device/nrf
+build/gen-device-svd: ./tools/gen-device-svd/*.go
+	$(GO) build -o $@ ./tools/gen-device-svd/
 
-gen-device-sam:
-	./tools/gen-device-svd.py lib/cmsis-svd/data/Atmel/ src/device/sam/ --source=https://github.com/posborne/cmsis-svd/tree/master/data/Atmel
-	go fmt ./src/device/sam
+gen-device-nrf: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk lib/nrfx/mdk/ src/device/nrf/
+	GO111MODULE=off $(GO) fmt ./src/device/nrf
+
+gen-device-sam: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Atmel lib/cmsis-svd/data/Atmel/ src/device/sam/
+	GO111MODULE=off $(GO) fmt ./src/device/sam
+
+gen-device-sifive: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/SiFive-Community -interrupts=software lib/cmsis-svd/data/SiFive-Community/ src/device/sifive/
+	GO111MODULE=off $(GO) fmt ./src/device/sifive
+
+gen-device-stm32: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/STMicro lib/cmsis-svd/data/STMicro/ src/device/stm32/
+	GO111MODULE=off $(GO) fmt ./src/device/stm32
+
+
+# Get LLVM sources.
+llvm-project/README.md:
+	git clone -b release/9.x https://github.com/llvm/llvm-project
+llvm-source: llvm-project/README.md
+
+# Configure LLVM.
+TINYGO_SOURCE_DIR=$(shell pwd)
+$(LLVM_BUILDDIR)/build.ninja: llvm-source
+	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/llvm-project/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
+
+# Build LLVM.
+$(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
+	cd $(LLVM_BUILDDIR); ninja
+
+
+# Build wasi-libc sysroot
+.PHONY: wasi-libc
+wasi-libc: lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a
+lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
+	cd lib/wasi-libc && make -j4 WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)
 
-gen-device-stm32:
-	./tools/gen-device-svd.py lib/cmsis-svd/data/STMicro/ src/device/stm32/ --source=https://github.com/posborne/cmsis-svd/tree/master/data/STMicro
-	go fmt ./src/device/stm32
 
 # Build the Go compiler.
 tinygo:
-	@mkdir -p build
-	go build -o build/tinygo .
+	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  make llvm-source"; echo "  make $(LLVM_BUILDDIR)"; exit 1; fi
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -o build/tinygo$(EXE) -tags byollvm .
 
-static:
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" go build -o build/tinygo -tags byollvm .
+test: wasi-libc
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -tags byollvm ./cgo ./compileopts ./interp ./transform .
 
-release: static gen-device
+tinygo-test:
+	cd tests/tinygotest && tinygo test
+
+.PHONY: smoketest
+smoketest:
+	$(TINYGO) version
+	# test all examples
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/adc
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinkm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/button
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/button2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/echo
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/mcp3008
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit            examples/microbit-blink
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/systick
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/test
+	@$(MD5SUM) test.hex
+	# test simulated boards on play.tinygo.org
+	$(TINYGO) build             -o test.wasm -tags=arduino              examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=hifive1b             examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=reelboard            examples/blinky1
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=pca10040             examples/blinky2
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=pca10056             examples/blinky2
+	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=circuitplay_express  examples/blinky1
+	@$(MD5SUM) test.wasm
+	# test all targets/boards
+	$(TINYGO) build -size short -o test.hex -target=pca10040-s132v6     examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit            examples/echo
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nrf52840-mdk        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10031            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=bluepill            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056            examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m0          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=trinket-m0          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky2
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.gba -target=gameboy-advance     examples/gba-display
+	@$(MD5SUM) test.gba
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pybadge             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=metro-m4-airlift    examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=nucleo-f103rb       examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pinetime-devkit0    examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=x9pro               examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10056-s140v7     examples/blinky1
+	@$(MD5SUM) test.hex
+ifneq ($(AVR), 0)
+	$(TINYGO) build -size short -o test.hex -target=arduino             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino-nano        examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=digispark           examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=digispark -gc=leaking examples/blinky1
+	@$(MD5SUM) test.hex
+endif
+	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/export
+	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/main
+
+release: tinygo gen-device wasi-libc
 	@mkdir -p build/release/tinygo/bin
+	@mkdir -p build/release/tinygo/lib/clang/include
 	@mkdir -p build/release/tinygo/lib/CMSIS/CMSIS
 	@mkdir -p build/release/tinygo/lib/compiler-rt/lib
 	@mkdir -p build/release/tinygo/lib/nrfx
+	@mkdir -p build/release/tinygo/lib/wasi-libc
 	@mkdir -p build/release/tinygo/pkg/armv6m-none-eabi
 	@mkdir -p build/release/tinygo/pkg/armv7m-none-eabi
 	@mkdir -p build/release/tinygo/pkg/armv7em-none-eabi
-	@cp -p  build/tinygo                 build/release/tinygo/bin
+	@echo copying source files
+	@cp -p  build/tinygo$(EXE)           build/release/tinygo/bin
+	@cp -p $(abspath $(CLANG_SRC))/lib/Headers/*.h build/release/tinygo/lib/clang/include
 	@cp -rp lib/CMSIS/CMSIS/Include      build/release/tinygo/lib/CMSIS/CMSIS
 	@cp -rp lib/CMSIS/README.md          build/release/tinygo/lib/CMSIS
 	@cp -rp lib/compiler-rt/lib/builtins build/release/tinygo/lib/compiler-rt/lib
 	@cp -rp lib/compiler-rt/LICENSE.TXT  build/release/tinygo/lib/compiler-rt
 	@cp -rp lib/compiler-rt/README.txt   build/release/tinygo/lib/compiler-rt
 	@cp -rp lib/nrfx/*                   build/release/tinygo/lib/nrfx
+	@cp -rp lib/wasi-libc/sysroot        build/release/tinygo/lib/wasi-libc/sysroot
 	@cp -rp src                          build/release/tinygo/src
 	@cp -rp targets                      build/release/tinygo/targets
 	./build/tinygo build-builtins -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/compiler-rt.a
 	./build/tinygo build-builtins -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/compiler-rt.a
 	./build/tinygo build-builtins -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/compiler-rt.a
 	tar -czf build/release.tar.gz -C build/release tinygo
-
-# Binary that can run on the host.
-build/%: src/examples/% src/examples/%/*.go build/tinygo src/runtime/*.go
-	./build/tinygo build $(TGOFLAGS) -size=short -o $@ $(subst src/,,$<)
-
-# ELF file that can run on a microcontroller.
-build/%.elf: src/examples/% src/examples/%/*.go build/tinygo src/runtime/*.go
-	./build/tinygo build $(TGOFLAGS) -size=short -o $@ $(subst src/,,$<)
-
-# Convert executable to Intel hex file (for flashing).
-build/%.hex: build/%.elf
-	$(OBJCOPY) -O ihex $^ $@

README.md

@@ -1,8 +1,8 @@
 # TinyGo - Go compiler for small places
 
-[![Build Status](https://travis-ci.com/tinygo-org/tinygo.svg?branch=dev)](https://travis-ci.com/tinygo-org/tinygo)
+[![CircleCI](https://circleci.com/gh/tinygo-org/tinygo/tree/dev.svg?style=svg)](https://circleci.com/gh/tinygo-org/tinygo/tree/dev) [![Build Status](https://dev.azure.com/tinygo/tinygo/_apis/build/status/tinygo-CI?branchName=dev)](https://dev.azure.com/tinygo/tinygo/_build/latest?definitionId=1&branchName=dev)
 
-TinyGo is a Go compiler intended for use in small places such as microcontrollers, WebAssembly (WASM), and command-line tools.
+TinyGo is a Go compiler intended for use in small places such as microcontrollers, WebAssembly (Wasm), and command-line tools.
 
 It reuses libraries used by the [Go language tools](https://golang.org/pkg/go/) alongside [LLVM](http://llvm.org) to provide an alternative way to compile programs written in the Go programming language.
 
@@ -17,8 +17,8 @@ import (
 )
 
 func main() {
-    led := machine.GPIO{machine.LED}
-    led.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+    led := machine.LED
+    led.Configure(machine.PinConfig{Mode: machine.PinOutput})
     for {
         led.Low()
         time.Sleep(time.Millisecond * 1000)
@@ -43,18 +43,35 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-The following microcontroller boards are currently supported:
+The following 27 microcontroller boards are currently supported:
 
+* [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
+* [Adafruit Circuit Playground Express](https://www.adafruit.com/product/3333)
+* [Adafruit Feather M0](https://www.adafruit.com/product/2772)
+* [Adafruit Feather M4](https://www.adafruit.com/product/3857)
 * [Adafruit ItsyBitsy M0](https://www.adafruit.com/product/3727)
+* [Adafruit ItsyBitsy M4](https://www.adafruit.com/product/3800)
+* [Adafruit Metro M4 Express Airlift](https://www.adafruit.com/product/4000)
+* [Adafruit PyBadge](https://www.adafruit.com/product/4200)
+* [Adafruit PyPortal](https://www.adafruit.com/product/4116)
+* [Adafruit Trinket M0](https://www.adafruit.com/product/3500)
+* [Arduino Nano](https://store.arduino.cc/arduino-nano)
+* [Arduino Nano33 IoT](https://store.arduino.cc/nano-33-iot)
 * [Arduino Uno](https://store.arduino.cc/arduino-uno-rev3)
-* [BBC:Microbit](https://microbit.org/)
-* [ST Micro STM32F103XX "Bluepill"](http://wiki.stm32duino.com/index.php?title=Blue_Pill)
+* [BBC micro:bit](https://microbit.org/)
 * [Digispark](http://digistump.com/products/1)
+* [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
+* [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
 * [Nordic Semiconductor PCA10031](https://www.nordicsemi.com/eng/Products/nRF51-Dongle)
 * [Nordic Semiconductor PCA10040](https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF52-DK)
 * [Nordic Semiconductor PCA10056](https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-DK)
-* [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
 * [Phytec reel board](https://www.phytec.eu/product-eu/internet-of-things/reelboard/)
+* [PineTime DevKit](https://www.pine64.org/pinetime/)
+* [SiFIve HiFive1](https://www.sifive.com/boards/hifive1)
+* [ST Micro "Nucleo F103RB"](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
+* [ST Micro STM32F103XX "Bluepill"](http://wiki.stm32duino.com/index.php?title=Blue_Pill)
+* [ST Micro STM32F407 "Discovery"](https://www.st.com/en/evaluation-tools/stm32f4discovery.html)
+* [X9 Pro smartwatch](https://github.com/curtpw/nRF5x-device-reverse-engineering/tree/master/X9-nrf52832-activity-tracker/)
 
 For more information, see [this list of boards](https://tinygo.org/microcontrollers/). Pull requests for additional support are welcome!
 
@@ -113,3 +130,5 @@ The original reasoning was: if [Python](https://micropython.org/) can run on mic
 ## License
 
 This project is licensed under the BSD 3-clause license, just like the [Go project](https://golang.org/LICENSE) itself.
+
+Some code has been copied from the LLVM project and is therefore licensed under [a variant of the Apache 2.0 license](http://releases.llvm.org/9.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.

azure-pipelines.yml

@@ -0,0 +1,84 @@
+# Avoid lengthy LLVM rebuilds on each newly pushed branch. Pull requests will
+# be built anyway.
+trigger:
+- master
+- dev
+
+jobs:
+- job: Build
+  timeoutInMinutes: 240 # 4h
+  pool:
+    vmImage: 'VS2017-Win2016'
+  steps:
+    - checkout: self
+    - task: CacheBeta@0
+      displayName: Cache LLVM source
+      inputs:
+        key: llvm-source-9-windows-v0
+        path: llvm-project
+    - task: Bash@3
+      displayName: Download LLVM source
+      inputs:
+        targetType: inline
+        script: make llvm-source
+    - task: CacheBeta@0
+      displayName: Cache LLVM build
+      inputs:
+        key: llvm-build-9-windows-v0
+        path: llvm-build
+    - task: Bash@3
+      displayName: Build LLVM
+      inputs:
+        targetType: inline
+        script: |
+          if [ ! -f llvm-build/lib/liblldELF.a ]
+          then
+            choco install ninja
+            # LLVM 9 cannot be built with MinGW 8.
+            # For details: https://reviews.llvm.org/D70266
+            choco uninstall mingw
+            choco install mingw --version=7.3.0
+            make llvm-build
+          fi
+    - task: Bash@3
+      displayName: Install QEMU
+      inputs:
+        targetType: inline
+        script: choco install qemu
+    - task: CacheBeta@0
+      displayName: Cache wasi-libc sysroot
+      inputs:
+        key: wasi-libc-sysroot-v0
+        path: lib/wasi-libc/sysroot
+    - task: Bash@3
+      displayName: Build wasi-libc
+      inputs:
+        targetType: inline
+        script: PATH=/usr/bin:$PATH make wasi-libc CLANG=$PWD/llvm-build/bin/clang LLVM_AR=$PWD/llvm-build/bin/llvm-ar LLVM_NM=$PWD/llvm-build/bin/llvm-nm
+    - task: Bash@3
+      displayName: Test TinyGo
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="/c/Go1.13/bin:$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make test
+    - task: Bash@3
+      displayName: Build TinyGo release tarball
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="/c/Go1.13/bin:$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make release -j4
+    - publish: $(System.DefaultWorkingDirectory)/build/release/tinygo
+      displayName: Publish zip as artifact
+      artifact: tinygo
+    - task: Bash@3
+      displayName: Smoke tests
+      inputs:
+        targetType: inline
+        script: |
+          export PATH="/c/Go1.13/bin:$PATH:./llvm-build/bin:/c/Program Files/qemu"
+          unset GOROOT
+          make smoketest TINYGO=build/tinygo AVR=0

builder/ar.go

@@ -0,0 +1,182 @@
+package builder
+
+import (
+	"bytes"
+	"debug/elf"
+	"encoding/binary"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/blakesmith/ar"
+)
+
+// makeArchive creates an arcive for static linking from a list of object files
+// given as a parameter. It is equivalent to the following command:
+//
+//     ar -rcs <archivePath> <objs...>
+func makeArchive(archivePath string, objs []string) error {
+	// Open the archive file.
+	arfile, err := os.Create(archivePath)
+	if err != nil {
+		return err
+	}
+	defer arfile.Close()
+	arwriter := ar.NewWriter(arfile)
+	err = arwriter.WriteGlobalHeader()
+	if err != nil {
+		return &os.PathError{"write ar header", archivePath, err}
+	}
+
+	// Open all object files and read the symbols for the symbol table.
+	symbolTable := []struct {
+		name      string // symbol name
+		fileIndex int    // index into objfiles
+	}{}
+	objfiles := make([]struct {
+		file          *os.File
+		archiveOffset int32
+	}, len(objs))
+	for i, objpath := range objs {
+		objfile, err := os.Open(objpath)
+		if err != nil {
+			return err
+		}
+		objfiles[i].file = objfile
+
+		// Read the symbols and add them to the symbol table.
+		dbg, err := elf.NewFile(objfile)
+		if err != nil {
+			return err
+		}
+		symbols, err := dbg.Symbols()
+		if err != nil {
+			return err
+		}
+		for _, symbol := range symbols {
+			bind := elf.ST_BIND(symbol.Info)
+			if bind != elf.STB_GLOBAL && bind != elf.STB_WEAK {
+				// Don't include local symbols (STB_LOCAL).
+				continue
+			}
+			if elf.ST_TYPE(symbol.Info) != elf.STT_FUNC {
+				// Not a function.
+				// TODO: perhaps globals variables should also be included?
+				continue
+			}
+			// Include in archive.
+			symbolTable = append(symbolTable, struct {
+				name      string
+				fileIndex int
+			}{symbol.Name, i})
+		}
+	}
+
+	// Create the symbol table buffer.
+	// For some (sparse) details on the file format:
+	// https://en.wikipedia.org/wiki/Ar_(Unix)#System_V_(or_GNU)_variant
+	buf := &bytes.Buffer{}
+	binary.Write(buf, binary.BigEndian, int32(len(symbolTable)))
+	for range symbolTable {
+		// This is a placeholder index, it will be updated after all files have
+		// been written to the archive (see the end of this function).
+		err = binary.Write(buf, binary.BigEndian, int32(0))
+		if err != nil {
+			return err
+		}
+	}
+	for _, sym := range symbolTable {
+		_, err := buf.Write([]byte(sym.name + "\x00"))
+		if err != nil {
+			return err
+		}
+	}
+	for buf.Len()%2 != 0 {
+		// The symbol table must be aligned.
+		// This appears to be required by lld.
+		buf.WriteByte(0)
+	}
+
+	// Write the symbol table.
+	err = arwriter.WriteHeader(&ar.Header{
+		Name:    "/",
+		ModTime: time.Unix(0, 0),
+		Uid:     0,
+		Gid:     0,
+		Mode:    0,
+		Size:    int64(buf.Len()),
+	})
+	if err != nil {
+		return err
+	}
+
+	// Keep track of the start of the symbol table.
+	symbolTableStart, err := arfile.Seek(0, os.SEEK_CUR)
+	if err != nil {
+		return err
+	}
+
+	// Write symbol table contents.
+	_, err = arfile.Write(buf.Bytes())
+	if err != nil {
+		return err
+	}
+
+	// Add all object files to the archive.
+	for i, objfile := range objfiles {
+		// Store the start index, for when we'll update the symbol table with
+		// the correct file start indices.
+		offset, err := arfile.Seek(0, os.SEEK_CUR)
+		if err != nil {
+			return err
+		}
+		if int64(int32(offset)) != offset {
+			return errors.New("large archives (4GB+) not supported: " + archivePath)
+		}
+		objfiles[i].archiveOffset = int32(offset)
+
+		// Write the file header.
+		st, err := objfile.file.Stat()
+		if err != nil {
+			return err
+		}
+		err = arwriter.WriteHeader(&ar.Header{
+			Name:    filepath.Base(objfile.file.Name()),
+			ModTime: time.Unix(0, 0),
+			Uid:     0,
+			Gid:     0,
+			Mode:    0644,
+			Size:    st.Size(),
+		})
+		if err != nil {
+			return err
+		}
+
+		// Copy the file contents into the archive.
+		n, err := io.Copy(arwriter, objfile.file)
+		if err != nil {
+			return err
+		}
+		if n != st.Size() {
+			return errors.New("file modified during ar creation: " + archivePath)
+		}
+
+		// File is not needed anymore.
+		objfile.file.Close()
+	}
+
+	// Create symbol indices.
+	indicesBuf := &bytes.Buffer{}
+	for _, sym := range symbolTable {
+		err = binary.Write(indicesBuf, binary.BigEndian, objfiles[sym.fileIndex].archiveOffset)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Overwrite placeholder indices.
+	_, err = arfile.WriteAt(indicesBuf.Bytes(), symbolTableStart+4)
+	return err
+}

builder/build.go

@@ -0,0 +1,218 @@
+// Package builder is the compiler driver of TinyGo. It takes in a package name
+// and an output path, and outputs an executable. It manages the entire
+// compilation pipeline in between.
+package builder
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/compiler"
+	"github.com/tinygo-org/tinygo/goenv"
+	"github.com/tinygo-org/tinygo/interp"
+	"github.com/tinygo-org/tinygo/transform"
+)
+
+// Build performs a single package to executable Go build. It takes in a package
+// name, an output path, and set of compile options and from that it manages the
+// whole compilation process.
+//
+// The error value may be of type *MultiError. Callers will likely want to check
+// for this case and print such errors individually.
+func Build(pkgName, outpath string, config *compileopts.Config, action func(string) error) error {
+	c, err := compiler.NewCompiler(pkgName, config)
+	if err != nil {
+		return err
+	}
+
+	// Compile Go code to IR.
+	errs := c.Compile(pkgName)
+	if len(errs) != 0 {
+		return newMultiError(errs)
+	}
+	if config.Options.PrintIR {
+		fmt.Println("; Generated LLVM IR:")
+		fmt.Println(c.IR())
+	}
+	if err := c.Verify(); err != nil {
+		return errors.New("verification error after IR construction")
+	}
+
+	err = interp.Run(c.Module(), config.DumpSSA())
+	if err != nil {
+		return err
+	}
+	if err := c.Verify(); err != nil {
+		return errors.New("verification error after interpreting runtime.initAll")
+	}
+
+	if config.GOOS() != "darwin" {
+		c.ApplyFunctionSections() // -ffunction-sections
+	}
+
+	// Browsers cannot handle external functions that have type i64 because it
+	// cannot be represented exactly in JavaScript (JS only has doubles). To
+	// keep functions interoperable, pass int64 types as pointers to
+	// stack-allocated values.
+	// Use -wasm-abi=generic to disable this behaviour.
+	if config.Options.WasmAbi == "js" && strings.HasPrefix(config.Triple(), "wasm") {
+		err := transform.ExternalInt64AsPtr(c.Module())
+		if err != nil {
+			return err
+		}
+	}
+
+	// Optimization levels here are roughly the same as Clang, but probably not
+	// exactly.
+	errs = nil
+	switch config.Options.Opt {
+	case "none:", "0":
+		errs = c.Optimize(0, 0, 0) // -O0
+	case "1":
+		errs = c.Optimize(1, 0, 0) // -O1
+	case "2":
+		errs = c.Optimize(2, 0, 225) // -O2
+	case "s":
+		errs = c.Optimize(2, 1, 225) // -Os
+	case "z":
+		errs = c.Optimize(2, 2, 5) // -Oz, default
+	default:
+		errs = []error{errors.New("unknown optimization level: -opt=" + config.Options.Opt)}
+	}
+	if len(errs) > 0 {
+		return newMultiError(errs)
+	}
+	if err := c.Verify(); err != nil {
+		return errors.New("verification failure after LLVM optimization passes")
+	}
+
+	// On the AVR, pointers can point either to flash or to RAM, but we don't
+	// know. As a temporary fix, load all global variables in RAM.
+	// In the future, there should be a compiler pass that determines which
+	// pointers are flash and which are in RAM so that pointers can have a
+	// correct address space parameter (address space 1 is for flash).
+	if strings.HasPrefix(config.Triple(), "avr") {
+		c.NonConstGlobals()
+		if err := c.Verify(); err != nil {
+			return errors.New("verification error after making all globals non-constant on AVR")
+		}
+	}
+
+	// Generate output.
+	outext := filepath.Ext(outpath)
+	switch outext {
+	case ".o":
+		return c.EmitObject(outpath)
+	case ".bc":
+		return c.EmitBitcode(outpath)
+	case ".ll":
+		return c.EmitText(outpath)
+	default:
+		// Act as a compiler driver.
+
+		// Create a temporary directory for intermediary files.
+		dir, err := ioutil.TempDir("", "tinygo")
+		if err != nil {
+			return err
+		}
+		defer os.RemoveAll(dir)
+
+		// Write the object file.
+		objfile := filepath.Join(dir, "main.o")
+		err = c.EmitObject(objfile)
+		if err != nil {
+			return err
+		}
+
+		// Load builtins library from the cache, possibly compiling it on the
+		// fly.
+		var librt string
+		if config.Target.RTLib == "compiler-rt" {
+			librt, err = loadBuiltins(config.Triple())
+			if err != nil {
+				return err
+			}
+		}
+
+		// Prepare link command.
+		executable := filepath.Join(dir, "main")
+		tmppath := executable // final file
+		ldflags := append(config.LDFlags(), "-o", executable, objfile)
+		if config.Target.RTLib == "compiler-rt" {
+			ldflags = append(ldflags, librt)
+		}
+
+		// Compile extra files.
+		root := goenv.Get("TINYGOROOT")
+		for i, path := range config.ExtraFiles() {
+			abspath := filepath.Join(root, path)
+			outpath := filepath.Join(dir, "extra-"+strconv.Itoa(i)+"-"+filepath.Base(path)+".o")
+			err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, abspath)...)
+			if err != nil {
+				return &commandError{"failed to build", path, err}
+			}
+			ldflags = append(ldflags, outpath)
+		}
+
+		// Compile C files in packages.
+		for i, pkg := range c.Packages() {
+			for _, file := range pkg.CFiles {
+				path := filepath.Join(pkg.Package.Dir, file)
+				outpath := filepath.Join(dir, "pkg"+strconv.Itoa(i)+"-"+file+".o")
+				err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, path)...)
+				if err != nil {
+					return &commandError{"failed to build", path, err}
+				}
+				ldflags = append(ldflags, outpath)
+			}
+		}
+
+		// Link the object files together.
+		err = link(config.Target.Linker, ldflags...)
+		if err != nil {
+			return &commandError{"failed to link", executable, err}
+		}
+
+		if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
+			sizes, err := loadProgramSize(executable)
+			if err != nil {
+				return err
+			}
+			if config.Options.PrintSizes == "short" {
+				fmt.Printf("   code    data     bss |   flash     ram\n")
+				fmt.Printf("%7d %7d %7d | %7d %7d\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+			} else {
+				fmt.Printf("   code  rodata    data     bss |   flash     ram | package\n")
+				for _, name := range sizes.sortedPackageNames() {
+					pkgSize := sizes.Packages[name]
+					fmt.Printf("%7d %7d %7d %7d | %7d %7d | %s\n", pkgSize.Code, pkgSize.ROData, pkgSize.Data, pkgSize.BSS, pkgSize.Flash(), pkgSize.RAM(), name)
+				}
+				fmt.Printf("%7d %7d %7d %7d | %7d %7d | (sum)\n", sizes.Sum.Code, sizes.Sum.ROData, sizes.Sum.Data, sizes.Sum.BSS, sizes.Sum.Flash(), sizes.Sum.RAM())
+				fmt.Printf("%7d       - %7d %7d | %7d %7d | (all)\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+			}
+		}
+
+		// Get an Intel .hex file or .bin file from the .elf file.
+		if outext == ".hex" || outext == ".bin" || outext == ".gba" {
+			tmppath = filepath.Join(dir, "main"+outext)
+			err := objcopy(executable, tmppath)
+			if err != nil {
+				return err
+			}
+		} else if outext == ".uf2" {
+			// Get UF2 from the .elf file.
+			tmppath = filepath.Join(dir, "main"+outext)
+			err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
+			if err != nil {
+				return err
+			}
+		}
+		return action(tmppath)
+	}
+}

builder/buildcache.go

@@ -1,18 +1,13 @@
-package main
+package builder
 
 import (
 	"io"
 	"os"
 	"path/filepath"
 	"time"
-)
 
-// Get the cache directory, usually ~/.cache/tinygo
-func cacheDir() string {
-	home := getHomeDir()
-	dir := filepath.Join(home, ".cache", "tinygo")
-	return dir
-}
+	"github.com/tinygo-org/tinygo/goenv"
+)
 
 // Return the newest timestamp of all the file paths passed in. Used to check
 // for stale caches.
@@ -39,8 +34,7 @@ func cacheTimestamp(paths []string) (time.Time, error) {
 // TODO: the configKey is currently ignored. It is supposed to be used as extra
 // data for the cache key, like the compiler version and arguments.
 func cacheLoad(name, configKey string, sourceFiles []string) (string, error) {
-	dir := cacheDir()
-	cachepath := filepath.Join(dir, name)
+	cachepath := filepath.Join(goenv.Get("GOCACHE"), name)
 	cacheStat, err := os.Stat(cachepath)
 	if os.IsNotExist(err) {
 		return "", nil // does not exist
@@ -74,7 +68,7 @@ func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string,
 
 	// TODO: check the config key
 
-	dir := cacheDir()
+	dir := goenv.Get("GOCACHE")
 	err := os.MkdirAll(dir, 0777)
 	if err != nil {
 		return "", err
@@ -115,10 +109,10 @@ func moveFile(src, dst string) error {
 		return err
 	}
 
-	err = os.Rename(dst+".tmp", dst)
+	err = outf.Close()
 	if err != nil {
 		return err
 	}
 
-	return outf.Close()
+	return os.Rename(dst+".tmp", dst)
 }

builder/builtins.go

@@ -1,11 +1,12 @@
-package main
+package builder
 
 import (
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
 )
 
 // These are the GENERIC_SOURCES according to CMakeList.txt.
@@ -157,7 +158,7 @@ var aeabiBuiltins = []string{
 
 func builtinFiles(target string) []string {
 	builtins := append([]string{}, genericBuiltins...) // copy genericBuiltins
-	if strings.HasPrefix(target, "arm") {
+	if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
 		builtins = append(builtins, aeabiBuiltins...)
 	}
 	return builtins
@@ -165,13 +166,13 @@ func builtinFiles(target string) []string {
 
 // builtinsDir returns the directory where the sources for compiler-rt are kept.
 func builtinsDir() string {
-	return filepath.Join(sourceDir(), "lib", "compiler-rt", "lib", "builtins")
+	return filepath.Join(goenv.Get("TINYGOROOT"), "lib", "compiler-rt", "lib", "builtins")
 }
 
 // Get the builtins archive, possibly generating it as needed.
 func loadBuiltins(target string) (path string, err error) {
 	// Try to load a precompiled compiler-rt library.
-	precompiledPath := filepath.Join(sourceDir(), "pkg", target, "compiler-rt.a")
+	precompiledPath := filepath.Join(goenv.Get("TINYGOROOT"), "pkg", target, "compiler-rt.a")
 	if _, err := os.Stat(precompiledPath); err == nil {
 		// Found a precompiled compiler-rt for this OS/architecture. Return the
 		// path directly.
@@ -187,24 +188,24 @@ func loadBuiltins(target string) (path string, err error) {
 		srcs[i] = filepath.Join(builtinsDir, name)
 	}
 
-	if path, err := cacheLoad(outfile, commands["clang"], srcs); path != "" || err != nil {
+	if path, err := cacheLoad(outfile, commands["clang"][0], srcs); path != "" || err != nil {
 		return path, err
 	}
 
 	var cachepath string
-	err = compileBuiltins(target, func(path string) error {
-		path, err := cacheStore(path, outfile, commands["clang"], srcs)
+	err = CompileBuiltins(target, func(path string) error {
+		path, err := cacheStore(path, outfile, commands["clang"][0], srcs)
 		cachepath = path
 		return err
 	})
 	return cachepath, err
 }
 
-// compileBuiltins compiles builtins from compiler-rt into a static library.
+// CompileBuiltins compiles builtins from compiler-rt into a static library.
 // When it succeeds, it will call the callback with the resulting path. The path
 // will be removed after callback returns. If callback returns an error, this is
 // passed through to the return value of this function.
-func compileBuiltins(target string, callback func(path string) error) error {
+func CompileBuiltins(target string, callback func(path string) error) error {
 	builtinsDir := builtinsDir()
 
 	builtins := builtinFiles(target)
@@ -235,25 +236,22 @@ func compileBuiltins(target string, callback func(path string) error) error {
 		// Note: -fdebug-prefix-map is necessary to make the output archive
 		// reproducible. Otherwise the temporary directory is stored in the
 		// archive itself, which varies each run.
-		cmd := exec.Command(commands["clang"], "-c", "-Oz", "-g", "-Werror", "-Wall", "-std=c11", "-fshort-enums", "-nostdlibinc", "-ffunction-sections", "-fdata-sections", "--target="+target, "-fdebug-prefix-map="+dir+"="+remapDir, "-o", objpath, srcpath)
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
-		cmd.Dir = dir
-		err = cmd.Run()
+		args := []string{"-c", "-Oz", "-g", "-Werror", "-Wall", "-std=c11", "-fshort-enums", "-nostdlibinc", "-ffunction-sections", "-fdata-sections", "-Wno-macro-redefined", "--target=" + target, "-fdebug-prefix-map=" + dir + "=" + remapDir}
+		if strings.HasPrefix(target, "riscv32-") {
+			args = append(args, "-march=rv32imac", "-mabi=ilp32", "-fforce-enable-int128")
+		}
+		err := runCCompiler("clang", append(args, "-o", objpath, srcpath)...)
 		if err != nil {
 			return &commandError{"failed to build", srcpath, err}
 		}
 	}
 
-	// Put all builtins in an archive to link as a static library.
+	// Put all the object files in a single archive. This archive file will be
+	// used to statically link compiler-rt.
 	arpath := filepath.Join(dir, "librt.a")
-	cmd := exec.Command(commands["ar"], append([]string{"cr", arpath}, objs...)...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	cmd.Dir = dir
-	err = cmd.Run()
+	err = makeArchive(arpath, objs)
 	if err != nil {
-		return &commandError{"failed to make static library", arpath, err}
+		return err
 	}
 
 	// Give the caller the resulting file. The callback must copy the file,

builder/cc1as.cpp

@@ -0,0 +1,504 @@
+// +build byollvm
+
+//===-- cc1as.cpp - Clang Assembler  --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the entry point to the clang -cc1as functionality, which implements
+// the direct interface to the LLVM MC based assembler.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Options.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Frontend/Utils.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCParser/MCAsmParser.h"
+#include "llvm/MC/MCParser/MCTargetAsmParser.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/OptTable.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include <memory>
+#include <system_error>
+using namespace clang;
+using namespace clang::driver;
+using namespace clang::driver::options;
+using namespace llvm;
+using namespace llvm::opt;
+
+#include "cc1as.h"
+
+bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
+                                         ArrayRef<const char *> Argv,
+                                         DiagnosticsEngine &Diags) {
+  bool Success = true;
+
+  // Parse the arguments.
+  std::unique_ptr<OptTable> OptTbl(createDriverOptTable());
+
+  const unsigned IncludedFlagsBitmask = options::CC1AsOption;
+  unsigned MissingArgIndex, MissingArgCount;
+  InputArgList Args = OptTbl->ParseArgs(Argv, MissingArgIndex, MissingArgCount,
+                                        IncludedFlagsBitmask);
+
+  // Check for missing argument error.
+  if (MissingArgCount) {
+    Diags.Report(diag::err_drv_missing_argument)
+        << Args.getArgString(MissingArgIndex) << MissingArgCount;
+    Success = false;
+  }
+
+  // Issue errors on unknown arguments.
+  for (const Arg *A : Args.filtered(OPT_UNKNOWN)) {
+    auto ArgString = A->getAsString(Args);
+    std::string Nearest;
+    if (OptTbl->findNearest(ArgString, Nearest, IncludedFlagsBitmask) > 1)
+      Diags.Report(diag::err_drv_unknown_argument) << ArgString;
+    else
+      Diags.Report(diag::err_drv_unknown_argument_with_suggestion)
+          << ArgString << Nearest;
+    Success = false;
+  }
+
+  // Construct the invocation.
+
+  // Target Options
+  Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
+  Opts.CPU = Args.getLastArgValue(OPT_target_cpu);
+  Opts.Features = Args.getAllArgValues(OPT_target_feature);
+
+  // Use the default target triple if unspecified.
+  if (Opts.Triple.empty())
+    Opts.Triple = llvm::sys::getDefaultTargetTriple();
+
+  // Language Options
+  Opts.IncludePaths = Args.getAllArgValues(OPT_I);
+  Opts.NoInitialTextSection = Args.hasArg(OPT_n);
+  Opts.SaveTemporaryLabels = Args.hasArg(OPT_msave_temp_labels);
+  // Any DebugInfoKind implies GenDwarfForAssembly.
+  Opts.GenDwarfForAssembly = Args.hasArg(OPT_debug_info_kind_EQ);
+
+  if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections,
+                                     OPT_compress_debug_sections_EQ)) {
+    if (A->getOption().getID() == OPT_compress_debug_sections) {
+      // TODO: be more clever about the compression type auto-detection
+      Opts.CompressDebugSections = llvm::DebugCompressionType::GNU;
+    } else {
+      Opts.CompressDebugSections =
+          llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue())
+              .Case("none", llvm::DebugCompressionType::None)
+              .Case("zlib", llvm::DebugCompressionType::Z)
+              .Case("zlib-gnu", llvm::DebugCompressionType::GNU)
+              .Default(llvm::DebugCompressionType::None);
+    }
+  }
+
+  Opts.RelaxELFRelocations = Args.hasArg(OPT_mrelax_relocations);
+  Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
+  Opts.DwarfDebugFlags = Args.getLastArgValue(OPT_dwarf_debug_flags);
+  Opts.DwarfDebugProducer = Args.getLastArgValue(OPT_dwarf_debug_producer);
+  Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
+  Opts.MainFileName = Args.getLastArgValue(OPT_main_file_name);
+
+  for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ))
+    Opts.DebugPrefixMap.insert(StringRef(Arg).split('='));
+
+  // Frontend Options
+  if (Args.hasArg(OPT_INPUT)) {
+    bool First = true;
+    for (const Arg *A : Args.filtered(OPT_INPUT)) {
+      if (First) {
+        Opts.InputFile = A->getValue();
+        First = false;
+      } else {
+        Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(Args);
+        Success = false;
+      }
+    }
+  }
+  Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
+  Opts.OutputPath = Args.getLastArgValue(OPT_o);
+  Opts.SplitDwarfOutput = Args.getLastArgValue(OPT_split_dwarf_output);
+  if (Arg *A = Args.getLastArg(OPT_filetype)) {
+    StringRef Name = A->getValue();
+    unsigned OutputType = StringSwitch<unsigned>(Name)
+      .Case("asm", FT_Asm)
+      .Case("null", FT_Null)
+      .Case("obj", FT_Obj)
+      .Default(~0U);
+    if (OutputType == ~0U) {
+      Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
+      Success = false;
+    } else
+      Opts.OutputType = FileType(OutputType);
+  }
+  Opts.ShowHelp = Args.hasArg(OPT_help);
+  Opts.ShowVersion = Args.hasArg(OPT_version);
+
+  // Transliterate Options
+  Opts.OutputAsmVariant =
+      getLastArgIntValue(Args, OPT_output_asm_variant, 0, Diags);
+  Opts.ShowEncoding = Args.hasArg(OPT_show_encoding);
+  Opts.ShowInst = Args.hasArg(OPT_show_inst);
+
+  // Assemble Options
+  Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
+  Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
+  Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
+  Opts.RelocationModel = Args.getLastArgValue(OPT_mrelocation_model, "pic");
+  Opts.TargetABI = Args.getLastArgValue(OPT_target_abi);
+  Opts.IncrementalLinkerCompatible =
+      Args.hasArg(OPT_mincremental_linker_compatible);
+  Opts.SymbolDefs = Args.getAllArgValues(OPT_defsym);
+
+  // EmbedBitcode Option. If -fembed-bitcode is enabled, set the flag.
+  // EmbedBitcode behaves the same for all embed options for assembly files.
+  if (auto *A = Args.getLastArg(OPT_fembed_bitcode_EQ)) {
+    Opts.EmbedBitcode = llvm::StringSwitch<unsigned>(A->getValue())
+                            .Case("all", 1)
+                            .Case("bitcode", 1)
+                            .Case("marker", 1)
+                            .Default(0);
+  }
+
+  return Success;
+}
+
+static std::unique_ptr<raw_fd_ostream>
+getOutputStream(StringRef Path, DiagnosticsEngine &Diags, bool Binary) {
+  // Make sure that the Out file gets unlinked from the disk if we get a
+  // SIGINT.
+  if (Path != "-")
+    sys::RemoveFileOnSignal(Path);
+
+  std::error_code EC;
+  auto Out = llvm::make_unique<raw_fd_ostream>(
+      Path, EC, (Binary ? sys::fs::F_None : sys::fs::F_Text));
+  if (EC) {
+    Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
+    return nullptr;
+  }
+
+  return Out;
+}
+
+bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags) {
+  // Get the target specific parser.
+  std::string Error;
+  const Target *TheTarget = TargetRegistry::lookupTarget(Opts.Triple, Error);
+  if (!TheTarget)
+    return Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
+
+  ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
+      MemoryBuffer::getFileOrSTDIN(Opts.InputFile);
+
+  if (std::error_code EC = Buffer.getError()) {
+    Error = EC.message();
+    return Diags.Report(diag::err_fe_error_reading) << Opts.InputFile;
+  }
+
+  SourceMgr SrcMgr;
+
+  // Tell SrcMgr about this buffer, which is what the parser will pick up.
+  unsigned BufferIndex = SrcMgr.AddNewSourceBuffer(std::move(*Buffer), SMLoc());
+
+  // Record the location of the include directories so that the lexer can find
+  // it later.
+  SrcMgr.setIncludeDirs(Opts.IncludePaths);
+
+  std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
+  assert(MRI && "Unable to create target register info!");
+
+  std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, Opts.Triple));
+  assert(MAI && "Unable to create target asm info!");
+
+  // Ensure MCAsmInfo initialization occurs before any use, otherwise sections
+  // may be created with a combination of default and explicit settings.
+  MAI->setCompressDebugSections(Opts.CompressDebugSections);
+
+  MAI->setRelaxELFRelocations(Opts.RelaxELFRelocations);
+
+  bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
+  if (Opts.OutputPath.empty())
+    Opts.OutputPath = "-";
+  std::unique_ptr<raw_fd_ostream> FDOS =
+      getOutputStream(Opts.OutputPath, Diags, IsBinary);
+  if (!FDOS)
+    return true;
+  std::unique_ptr<raw_fd_ostream> DwoOS;
+  if (!Opts.SplitDwarfOutput.empty())
+    DwoOS = getOutputStream(Opts.SplitDwarfOutput, Diags, IsBinary);
+
+  // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
+  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
+  std::unique_ptr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
+
+  MCContext Ctx(MAI.get(), MRI.get(), MOFI.get(), &SrcMgr);
+
+  bool PIC = false;
+  if (Opts.RelocationModel == "static") {
+    PIC = false;
+  } else if (Opts.RelocationModel == "pic") {
+    PIC = true;
+  } else {
+    assert(Opts.RelocationModel == "dynamic-no-pic" &&
+           "Invalid PIC model!");
+    PIC = false;
+  }
+
+  MOFI->InitMCObjectFileInfo(Triple(Opts.Triple), PIC, Ctx);
+  if (Opts.SaveTemporaryLabels)
+    Ctx.setAllowTemporaryLabels(false);
+  if (Opts.GenDwarfForAssembly)
+    Ctx.setGenDwarfForAssembly(true);
+  if (!Opts.DwarfDebugFlags.empty())
+    Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
+  if (!Opts.DwarfDebugProducer.empty())
+    Ctx.setDwarfDebugProducer(StringRef(Opts.DwarfDebugProducer));
+  if (!Opts.DebugCompilationDir.empty())
+    Ctx.setCompilationDir(Opts.DebugCompilationDir);
+  else {
+    // If no compilation dir is set, try to use the current directory.
+    SmallString<128> CWD;
+    if (!sys::fs::current_path(CWD))
+      Ctx.setCompilationDir(CWD);
+  }
+  if (!Opts.DebugPrefixMap.empty())
+    for (const auto &KV : Opts.DebugPrefixMap)
+      Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
+  if (!Opts.MainFileName.empty())
+    Ctx.setMainFileName(StringRef(Opts.MainFileName));
+  Ctx.setDwarfVersion(Opts.DwarfVersion);
+  if (Opts.GenDwarfForAssembly)
+    Ctx.setGenDwarfRootFile(Opts.InputFile,
+                            SrcMgr.getMemoryBuffer(BufferIndex)->getBuffer());
+
+  // Build up the feature string from the target feature list.
+  std::string FS;
+  if (!Opts.Features.empty()) {
+    FS = Opts.Features[0];
+    for (unsigned i = 1, e = Opts.Features.size(); i != e; ++i)
+      FS += "," + Opts.Features[i];
+  }
+
+  std::unique_ptr<MCStreamer> Str;
+
+  std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
+  std::unique_ptr<MCSubtargetInfo> STI(
+      TheTarget->createMCSubtargetInfo(Opts.Triple, Opts.CPU, FS));
+
+  raw_pwrite_stream *Out = FDOS.get();
+  std::unique_ptr<buffer_ostream> BOS;
+
+  MCTargetOptions MCOptions;
+  MCOptions.ABIName = Opts.TargetABI;
+
+  // FIXME: There is a bit of code duplication with addPassesToEmitFile.
+  if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
+    MCInstPrinter *IP = TheTarget->createMCInstPrinter(
+        llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
+
+    std::unique_ptr<MCCodeEmitter> CE;
+    if (Opts.ShowEncoding)
+      CE.reset(TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
+    std::unique_ptr<MCAsmBackend> MAB(
+        TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
+
+    auto FOut = llvm::make_unique<formatted_raw_ostream>(*Out);
+    Str.reset(TheTarget->createAsmStreamer(
+        Ctx, std::move(FOut), /*asmverbose*/ true,
+        /*useDwarfDirectory*/ true, IP, std::move(CE), std::move(MAB),
+        Opts.ShowInst));
+  } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
+    Str.reset(createNullStreamer(Ctx));
+  } else {
+    assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
+           "Invalid file type!");
+    if (!FDOS->supportsSeeking()) {
+      BOS = make_unique<buffer_ostream>(*FDOS);
+      Out = BOS.get();
+    }
+
+    std::unique_ptr<MCCodeEmitter> CE(
+        TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
+    std::unique_ptr<MCAsmBackend> MAB(
+        TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
+    std::unique_ptr<MCObjectWriter> OW =
+        DwoOS ? MAB->createDwoObjectWriter(*Out, *DwoOS)
+              : MAB->createObjectWriter(*Out);
+
+    Triple T(Opts.Triple);
+    Str.reset(TheTarget->createMCObjectStreamer(
+        T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI,
+        Opts.RelaxAll, Opts.IncrementalLinkerCompatible,
+        /*DWARFMustBeAtTheEnd*/ true));
+    Str.get()->InitSections(Opts.NoExecStack);
+  }
+
+  // When -fembed-bitcode is passed to clang_as, a 1-byte marker
+  // is emitted in __LLVM,__asm section if the object file is MachO format.
+  if (Opts.EmbedBitcode && Ctx.getObjectFileInfo()->getObjectFileType() ==
+                               MCObjectFileInfo::IsMachO) {
+    MCSection *AsmLabel = Ctx.getMachOSection(
+        "__LLVM", "__asm", MachO::S_REGULAR, 4, SectionKind::getReadOnly());
+    Str.get()->SwitchSection(AsmLabel);
+    Str.get()->EmitZeros(1);
+  }
+
+  // Assembly to object compilation should leverage assembly info.
+  Str->setUseAssemblerInfoForParsing(true);
+
+  bool Failed = false;
+
+  std::unique_ptr<MCAsmParser> Parser(
+      createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
+
+  // FIXME: init MCTargetOptions from sanitizer flags here.
+  std::unique_ptr<MCTargetAsmParser> TAP(
+      TheTarget->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
+  if (!TAP)
+    Failed = Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
+
+  // Set values for symbols, if any.
+  for (auto &S : Opts.SymbolDefs) {
+    auto Pair = StringRef(S).split('=');
+    auto Sym = Pair.first;
+    auto Val = Pair.second;
+    int64_t Value;
+    // We have already error checked this in the driver.
+    Val.getAsInteger(0, Value);
+    Ctx.setSymbolValue(Parser->getStreamer(), Sym, Value);
+  }
+
+  if (!Failed) {
+    Parser->setTargetParser(*TAP.get());
+    Failed = Parser->Run(Opts.NoInitialTextSection);
+  }
+
+  // Close Streamer first.
+  // It might have a reference to the output stream.
+  Str.reset();
+  // Close the output stream early.
+  BOS.reset();
+  FDOS.reset();
+
+  // Delete output file if there were errors.
+  if (Failed) {
+    if (Opts.OutputPath != "-")
+      sys::fs::remove(Opts.OutputPath);
+    if (!Opts.SplitDwarfOutput.empty() && Opts.SplitDwarfOutput != "-")
+      sys::fs::remove(Opts.SplitDwarfOutput);
+  }
+
+  return Failed;
+}
+
+static void LLVMErrorHandler(void *UserData, const std::string &Message,
+                             bool GenCrashDiag) {
+  DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
+
+  Diags.Report(diag::err_fe_error_backend) << Message;
+
+  // We cannot recover from llvm errors.
+  exit(1);
+}
+
+int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
+  // Initialize targets and assembly printers/parsers.
+  InitializeAllTargetInfos();
+  InitializeAllTargetMCs();
+  InitializeAllAsmParsers();
+
+  // Construct our diagnostic client.
+  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
+  TextDiagnosticPrinter *DiagClient
+    = new TextDiagnosticPrinter(errs(), &*DiagOpts);
+  DiagClient->setPrefix("clang -cc1as");
+  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
+  DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
+
+  // Set an error handler, so that any LLVM backend diagnostics go through our
+  // error handler.
+  ScopedFatalErrorHandler FatalErrorHandler
+    (LLVMErrorHandler, static_cast<void*>(&Diags));
+
+  // Parse the arguments.
+  AssemblerInvocation Asm;
+  if (!AssemblerInvocation::CreateFromArgs(Asm, Argv, Diags))
+    return 1;
+
+  if (Asm.ShowHelp) {
+    std::unique_ptr<OptTable> Opts(driver::createDriverOptTable());
+    Opts->PrintHelp(llvm::outs(), "clang -cc1as [options] file...",
+                    "Clang Integrated Assembler",
+                    /*Include=*/driver::options::CC1AsOption, /*Exclude=*/0,
+                    /*ShowAllAliases=*/false);
+    return 0;
+  }
+
+  // Honor -version.
+  //
+  // FIXME: Use a better -version message?
+  if (Asm.ShowVersion) {
+    llvm::cl::PrintVersionMessage();
+    return 0;
+  }
+
+  // Honor -mllvm.
+  //
+  // FIXME: Remove this, one day.
+  if (!Asm.LLVMArgs.empty()) {
+    unsigned NumArgs = Asm.LLVMArgs.size();
+    auto Args = llvm::make_unique<const char*[]>(NumArgs + 2);
+    Args[0] = "clang (LLVM option parsing)";
+    for (unsigned i = 0; i != NumArgs; ++i)
+      Args[i + 1] = Asm.LLVMArgs[i].c_str();
+    Args[NumArgs + 1] = nullptr;
+    llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
+  }
+
+  // Execute the invocation, unless there were parsing errors.
+  bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
+
+  // If any timers were active but haven't been destroyed yet, print their
+  // results now.
+  TimerGroup::printAll(errs());
+
+  return !!Failed;
+}

builder/cc1as.h

@@ -0,0 +1,120 @@
+//===-- cc1as.h - Clang Assembler  ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the entry point to the clang -cc1as functionality, which implements
+// the direct interface to the LLVM MC based assembler.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ArrayRef.h"
+
+/// Helper class for representing a single invocation of the assembler.
+struct AssemblerInvocation {
+  /// @name Target Options
+  /// @{
+
+  /// The name of the target triple to assemble for.
+  std::string Triple;
+
+  /// If given, the name of the target CPU to determine which instructions
+  /// are legal.
+  std::string CPU;
+
+  /// The list of target specific features to enable or disable -- this should
+  /// be a list of strings starting with '+' or '-'.
+  std::vector<std::string> Features;
+
+  /// The list of symbol definitions.
+  std::vector<std::string> SymbolDefs;
+
+  /// @}
+  /// @name Language Options
+  /// @{
+
+  std::vector<std::string> IncludePaths;
+  unsigned NoInitialTextSection : 1;
+  unsigned SaveTemporaryLabels : 1;
+  unsigned GenDwarfForAssembly : 1;
+  unsigned RelaxELFRelocations : 1;
+  unsigned DwarfVersion;
+  std::string DwarfDebugFlags;
+  std::string DwarfDebugProducer;
+  std::string DebugCompilationDir;
+  std::map<const std::string, const std::string> DebugPrefixMap;
+  llvm::DebugCompressionType CompressDebugSections =
+      llvm::DebugCompressionType::None;
+  std::string MainFileName;
+  std::string SplitDwarfOutput;
+
+  /// @}
+  /// @name Frontend Options
+  /// @{
+
+  std::string InputFile;
+  std::vector<std::string> LLVMArgs;
+  std::string OutputPath;
+  enum FileType {
+    FT_Asm,  ///< Assembly (.s) output, transliterate mode.
+    FT_Null, ///< No output, for timing purposes.
+    FT_Obj   ///< Object file output.
+  };
+  FileType OutputType;
+  unsigned ShowHelp : 1;
+  unsigned ShowVersion : 1;
+
+  /// @}
+  /// @name Transliterate Options
+  /// @{
+
+  unsigned OutputAsmVariant;
+  unsigned ShowEncoding : 1;
+  unsigned ShowInst : 1;
+
+  /// @}
+  /// @name Assembler Options
+  /// @{
+
+  unsigned RelaxAll : 1;
+  unsigned NoExecStack : 1;
+  unsigned FatalWarnings : 1;
+  unsigned IncrementalLinkerCompatible : 1;
+  unsigned EmbedBitcode : 1;
+
+  /// The name of the relocation model to use.
+  std::string RelocationModel;
+
+  /// The ABI targeted by the backend. Specified using -target-abi. Empty
+  /// otherwise.
+  std::string TargetABI;
+
+  /// @}
+
+public:
+  AssemblerInvocation() {
+    Triple = "";
+    NoInitialTextSection = 0;
+    InputFile = "-";
+    OutputPath = "-";
+    OutputType = FT_Asm;
+    OutputAsmVariant = 0;
+    ShowInst = 0;
+    ShowEncoding = 0;
+    RelaxAll = 0;
+    NoExecStack = 0;
+    FatalWarnings = 0;
+    IncrementalLinkerCompatible = 0;
+    DwarfVersion = 0;
+    EmbedBitcode = 0;
+  }
+
+  static bool CreateFromArgs(AssemblerInvocation &Res,
+                             ArrayRef<const char *> Argv,
+                             DiagnosticsEngine &Diags);
+};
+
+bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags);

builder/clang.cpp

@@ -0,0 +1,97 @@
+// +build byollvm
+
+#include <clang/Basic/DiagnosticOptions.h>
+#include <clang/CodeGen/CodeGenAction.h>
+#include <clang/Driver/Compilation.h>
+#include <clang/Driver/Driver.h>
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/CompilerInvocation.h>
+#include <clang/Frontend/FrontendDiagnostic.h>
+#include <clang/Frontend/TextDiagnosticPrinter.h>
+#include <clang/FrontendTool/Utils.h>
+#include <llvm/ADT/IntrusiveRefCntPtr.h>
+#include <llvm/Option/Option.h>
+
+using namespace llvm;
+using namespace clang;
+
+#include "cc1as.h"
+
+// This file provides C wrappers for the builtin tools cc1 and cc1as
+// provided by Clang, and calls them as the driver would call them.
+
+extern "C" {
+
+bool tinygo_clang_driver(int argc, char **argv) {
+	std::vector<const char*> args(argv, argv + argc);
+
+	// The compiler invocation needs a DiagnosticsEngine so it can report problems
+	llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> DiagOpts = new clang::DiagnosticOptions();
+	clang::TextDiagnosticPrinter DiagnosticPrinter(llvm::errs(), &*DiagOpts);
+	clang::DiagnosticsEngine Diags(llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs>(new clang::DiagnosticIDs()), &*DiagOpts, &DiagnosticPrinter, false);
+
+	// Create the clang driver
+	clang::driver::Driver TheDriver(args[0], llvm::sys::getDefaultTargetTriple(), Diags);
+
+	// Create the set of actions to perform
+	std::unique_ptr<clang::driver::Compilation> C(TheDriver.BuildCompilation(args));
+	if (!C) {
+		return false;
+	}
+	const clang::driver::JobList &Jobs = C->getJobs();
+
+	// There may be more than one job, for example for .S files
+	// (preprocessor + assembler).
+	for (auto Cmd : Jobs) {
+		// Select the tool: cc1 or cc1as.
+		const llvm::opt::ArgStringList &CCArgs = Cmd.getArguments();
+
+		if (strcmp(*CCArgs.data(), "-cc1") == 0) {
+			// This is the C frontend.
+			// Initialize a compiler invocation object from the clang (-cc1) arguments.
+			std::unique_ptr<clang::CompilerInstance> Clang(new clang::CompilerInstance());
+			bool success = clang::CompilerInvocation::CreateFromArgs(
+					Clang->getInvocation(),
+					const_cast<const char **>(CCArgs.data()),
+					const_cast<const char **>(CCArgs.data()) + CCArgs.size(),
+					Diags);
+			if (!success) {
+				return false;
+			}
+
+			// Create the actual diagnostics engine.
+			Clang->createDiagnostics();
+			if (!Clang->hasDiagnostics()) {
+				return false;
+			}
+
+			// Execute the frontend actions.
+			success = ExecuteCompilerInvocation(Clang.get());
+			if (!success) {
+				return false;
+			}
+
+		} else if (strcmp(*CCArgs.data(), "-cc1as") == 0) {
+			// This is the assembler frontend. Parse the arguments.
+			AssemblerInvocation Asm;
+			if (!AssemblerInvocation::CreateFromArgs(Asm, llvm::ArrayRef<const char*>(CCArgs).slice(1), Diags))
+				return false;
+
+			// Execute the invocation, unless there were parsing errors.
+			bool failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
+			if (failed) {
+				return false;
+			}
+
+		} else {
+			// Unknown tool, print the tool and exit.
+			fprintf(stderr, "unknown tool: %s\n", *CCArgs.data());
+			return false;
+		}
+	}
+
+	// Commands executed successfully.
+	return true;
+}
+
+} // extern "C"

builder/commands.go

@@ -0,0 +1,61 @@
+package builder
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+// Commands lists command alternatives for various operating systems. These
+// commands may have a slightly different name across operating systems and
+// distributions or may not even exist in $PATH, in which case absolute paths
+// may be used.
+var commands = map[string][]string{
+	"clang":   {"clang-9"},
+	"ld.lld":  {"ld.lld-9", "ld.lld"},
+	"wasm-ld": {"wasm-ld-9", "wasm-ld"},
+}
+
+func init() {
+	// Add the path to a Homebrew-installed LLVM 9 for ease of use (no need to
+	// manually set $PATH).
+	if runtime.GOOS == "darwin" {
+		commands["clang"] = append(commands["clang"], "/usr/local/opt/llvm@9/bin/clang-9")
+		commands["ld.lld"] = append(commands["ld.lld"], "/usr/local/opt/llvm@9/bin/ld.lld")
+		commands["wasm-ld"] = append(commands["wasm-ld"], "/usr/local/opt/llvm@9/bin/wasm-ld")
+	}
+	// Add the path for when LLVM was installed with the installer from
+	// llvm.org, which by default doesn't add LLVM to the $PATH environment
+	// variable.
+	if runtime.GOOS == "windows" {
+		commands["clang"] = append(commands["clang"], "clang", "C:\\Program Files\\LLVM\\bin\\clang.exe")
+		commands["ld.lld"] = append(commands["ld.lld"], "lld", "C:\\Program Files\\LLVM\\bin\\lld.exe")
+		commands["wasm-ld"] = append(commands["wasm-ld"], "C:\\Program Files\\LLVM\\bin\\wasm-ld.exe")
+	}
+	// Add the path to the llvm90 installed from ports
+	if runtime.GOOS == "freebsd" {
+		commands["clang"] = append(commands["clang"], "/usr/local/llvm90/bin/clang-9")
+		commands["ld.lld"] = append(commands["ld.lld"], "/usr/local/llvm90/bin/ld.lld")
+		commands["wasm-ld"] = append(commands["wasm-ld"], "/usr/local/llvm90/bin/wasm-ld")
+	}
+}
+
+func execCommand(cmdNames []string, args ...string) error {
+	for _, cmdName := range cmdNames {
+		cmd := exec.Command(cmdName, args...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err := cmd.Run()
+		if err != nil {
+			if err, ok := err.(*exec.Error); ok && (err.Err == exec.ErrNotFound || err.Err.Error() == "file does not exist") {
+				// this command was not found, try the next
+				continue
+			}
+			return err
+		}
+		return nil
+	}
+	return errors.New("none of these commands were found in your $PATH: " + strings.Join(cmdNames, " "))
+}

builder/compiler-builtin.go

@@ -0,0 +1,60 @@
+// +build byollvm
+
+package builder
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"unsafe"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+/*
+#cgo CXXFLAGS: -fno-rtti
+#include <stdbool.h>
+#include <stdlib.h>
+bool tinygo_clang_driver(int argc, char **argv);
+*/
+import "C"
+
+// runCCompiler invokes a C compiler with the given arguments.
+//
+// This version invokes the built-in Clang when trying to run the Clang compiler.
+func runCCompiler(command string, flags ...string) error {
+	switch command {
+	case "clang":
+		// Compile this with the internal Clang compiler.
+		headerPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
+		if headerPath == "" {
+			return errors.New("could not locate Clang headers")
+		}
+		flags = append(flags, "-I"+headerPath)
+		flags = append([]string{"tinygo:" + command}, flags...)
+		var cflag *C.char
+		buf := C.calloc(C.size_t(len(flags)), C.size_t(unsafe.Sizeof(cflag)))
+		cflags := (*[1 << 10]*C.char)(unsafe.Pointer(buf))[:len(flags):len(flags)]
+		for i, flag := range flags {
+			cflag := C.CString(flag)
+			cflags[i] = cflag
+			defer C.free(unsafe.Pointer(cflag))
+		}
+		ok := C.tinygo_clang_driver(C.int(len(flags)), (**C.char)(buf))
+		if !ok {
+			return errors.New("failed to compile using built-in clang")
+		}
+		return nil
+	default:
+		// Running some other compiler. Maybe it has been defined in the
+		// commands map (unlikely).
+		if cmdNames, ok := commands[command]; ok {
+			return execCommand(cmdNames, flags...)
+		}
+		// Alternatively, run the compiler directly.
+		cmd := exec.Command(command, flags...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+}

builder/compiler-external.go

@@ -0,0 +1,24 @@
+// +build !byollvm
+
+package builder
+
+// This file provides a way to a C compiler as an external command. See also:
+// clang-external.go
+
+import (
+	"os"
+	"os/exec"
+)
+
+// runCCompiler invokes a C compiler with the given arguments.
+//
+// This version always runs the compiler as an external command.
+func runCCompiler(command string, flags ...string) error {
+	if cmdNames, ok := commands[command]; ok {
+		return execCommand(cmdNames, flags...)
+	}
+	cmd := exec.Command(command, flags...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}

builder/config.go

@@ -0,0 +1,39 @@
+package builder
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// NewConfig builds a new Config object from a set of compiler options. It also
+// loads some information from the environment while doing that. For example, it
+// uses the currently active GOPATH (from the goenv package) to determine the Go
+// version to use.
+func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
+	spec, err := compileopts.LoadTarget(options.Target)
+	if err != nil {
+		return nil, err
+	}
+	goroot := goenv.Get("GOROOT")
+	if goroot == "" {
+		return nil, errors.New("cannot locate $GOROOT, please set it manually")
+	}
+	major, minor, err := getGorootVersion(goroot)
+	if err != nil {
+		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
+	}
+	if major != 1 || (minor != 11 && minor != 12 && minor != 13) {
+		return nil, fmt.Errorf("requires go version 1.11, 1.12, or 1.13, got go%d.%d", major, minor)
+	}
+	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
+	return &compileopts.Config{
+		Options:        options,
+		Target:         spec,
+		GoMinorVersion: minor,
+		ClangHeaders:   clangHeaderPath,
+		TestConfig:     options.TestConfig,
+	}, nil
+}

builder/env.go

@@ -0,0 +1,127 @@
+package builder
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// getGorootVersion returns the major and minor version for a given GOROOT path.
+// If the goroot cannot be determined, (0, 0) is returned.
+func getGorootVersion(goroot string) (major, minor int, err error) {
+	s, err := GorootVersionString(goroot)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	if s == "" || s[:2] != "go" {
+		return 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
+	}
+
+	parts := strings.Split(s[2:], ".")
+	if len(parts) < 2 {
+		return 0, 0, errors.New("could not parse Go version: version has less than two parts")
+	}
+
+	// Ignore the errors, we don't really handle errors here anyway.
+	var trailing string
+	n, err := fmt.Sscanf(s, "go%d.%d%s", &major, &minor, &trailing)
+	if n == 2 && err == io.EOF {
+		// Means there were no trailing characters (i.e., not an alpha/beta)
+		err = nil
+	}
+	if err != nil {
+		return 0, 0, fmt.Errorf("failed to parse version: %s", err)
+	}
+	return
+}
+
+// GorootVersionString returns the version string as reported by the Go
+// toolchain for the given GOROOT path. It is usually of the form `go1.x.y` but
+// can have some variations (for beta releases, for example).
+func GorootVersionString(goroot string) (string, error) {
+	if data, err := ioutil.ReadFile(filepath.Join(
+		goroot, "src", "runtime", "internal", "sys", "zversion.go")); err == nil {
+
+		r := regexp.MustCompile("const TheVersion = `(.*)`")
+		matches := r.FindSubmatch(data)
+		if len(matches) != 2 {
+			return "", errors.New("Invalid go version output:\n" + string(data))
+		}
+
+		return string(matches[1]), nil
+
+	} else if data, err := ioutil.ReadFile(filepath.Join(goroot, "VERSION")); err == nil {
+		return string(data), nil
+
+	} else {
+		return "", err
+	}
+}
+
+// getClangHeaderPath returns the path to the built-in Clang headers. It tries
+// multiple locations, which should make it find the directory when installed in
+// various ways.
+func getClangHeaderPath(TINYGOROOT string) string {
+	// Check whether we're running from the source directory.
+	path := filepath.Join(TINYGOROOT, "llvm-project", "clang", "lib", "Headers")
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return path
+	}
+
+	// Check whether we're running from the installation directory.
+	path = filepath.Join(TINYGOROOT, "lib", "clang", "include")
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return path
+	}
+
+	// It looks like we are built with a system-installed LLVM. Do a last
+	// attempt: try to use Clang headers relative to the clang binary.
+	for _, cmdName := range commands["clang"] {
+		binpath, err := exec.LookPath(cmdName)
+		if err == nil {
+			// This should be the command that will also be used by
+			// execCommand. To avoid inconsistencies, make sure we use the
+			// headers relative to this command.
+			binpath, err = filepath.EvalSymlinks(binpath)
+			if err != nil {
+				// Unexpected.
+				return ""
+			}
+			// Example executable:
+			//     /usr/lib/llvm-9/bin/clang
+			// Example include path:
+			//     /usr/lib/llvm-9/lib/clang/9.0.1/include/
+			llvmRoot := filepath.Dir(filepath.Dir(binpath))
+			clangVersionRoot := filepath.Join(llvmRoot, "lib", "clang")
+			dirs, err := ioutil.ReadDir(clangVersionRoot)
+			if err != nil {
+				// Unexpected.
+				continue
+			}
+			dirnames := make([]string, len(dirs))
+			for i, d := range dirs {
+				dirnames[i] = d.Name()
+			}
+			sort.Strings(dirnames)
+			// Check for the highest version first.
+			for i := len(dirnames) - 1; i >= 0; i-- {
+				path := filepath.Join(clangVersionRoot, dirnames[i], "include")
+				_, err := os.Stat(filepath.Join(path, "stdint.h"))
+				if err == nil {
+					return path
+				}
+			}
+		}
+	}
+
+	// Could not find it.
+	return ""
+}

builder/error.go

@@ -0,0 +1,39 @@
+package builder
+
+// MultiError is a list of multiple errors (actually: diagnostics) returned
+// during LLVM IR generation.
+type MultiError struct {
+	Errs []error
+}
+
+func (e *MultiError) Error() string {
+	// Return the first error, to conform to the error interface. Clients should
+	// really do a type-assertion on *MultiError.
+	return e.Errs[0].Error()
+}
+
+// newMultiError returns a *MultiError if there is more than one error, or
+// returns that error directly when there is only one. Passing an empty slice
+// will lead to a panic.
+func newMultiError(errs []error) error {
+	switch len(errs) {
+	case 0:
+		panic("attempted to create empty MultiError")
+	case 1:
+		return errs[0]
+	default:
+		return &MultiError{errs}
+	}
+}
+
+// commandError is an error type to wrap os/exec.Command errors. This provides
+// some more information regarding what went wrong while running a command.
+type commandError struct {
+	Msg  string
+	File string
+	Err  error
+}
+
+func (e *commandError) Error() string {
+	return e.Msg + " " + e.File + ": " + e.Err.Error()
+}

builder/linker-builtin.go

@@ -1,6 +1,6 @@
 // +build byollvm
 
-package main
+package builder
 
 // This file provides a Link() function that uses the bundled lld if possible.
 
@@ -9,6 +9,8 @@ import (
 	"os"
 	"os/exec"
 	"unsafe"
+
+	"github.com/tinygo-org/tinygo/goenv"
 )
 
 /*
@@ -19,12 +21,12 @@ bool tinygo_link_wasm(int argc, char **argv);
 */
 import "C"
 
-// Link invokes a linker with the given name and flags.
+// link invokes a linker with the given name and flags.
 //
 // This version uses the built-in linker when trying to use lld.
-func Link(dir, linker string, flags ...string) error {
+func link(linker string, flags ...string) error {
 	switch linker {
-	case "ld.lld", commands["ld.lld"]:
+	case "ld.lld":
 		flags = append([]string{"tinygo:" + linker}, flags...)
 		var cflag *C.char
 		buf := C.calloc(C.size_t(len(flags)), C.size_t(unsafe.Sizeof(cflag)))
@@ -39,7 +41,7 @@ func Link(dir, linker string, flags ...string) error {
 			return errors.New("failed to link using built-in ld.lld")
 		}
 		return nil
-	case "wasm-ld", commands["wasm-ld"]:
+	case "wasm-ld":
 		flags = append([]string{"tinygo:" + linker}, flags...)
 		var cflag *C.char
 		buf := C.calloc(C.size_t(len(flags)), C.size_t(unsafe.Sizeof(cflag)))
@@ -57,10 +59,13 @@ func Link(dir, linker string, flags ...string) error {
 		return nil
 	default:
 		// Fall back to external command.
+		if cmdNames, ok := commands[linker]; ok {
+			return execCommand(cmdNames, flags...)
+		}
 		cmd := exec.Command(linker, flags...)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
-		cmd.Dir = dir
+		cmd.Dir = goenv.Get("TINYGOROOT")
 		return cmd.Run()
 	}
 }

builder/linker-external.go

@@ -1,6 +1,6 @@
 // +build !byollvm
 
-package main
+package builder
 
 // This file provides a Link() function that always runs an external command. It
 // is provided for when tinygo is built without linking to liblld.
@@ -8,15 +8,20 @@ package main
 import (
 	"os"
 	"os/exec"
+
+	"github.com/tinygo-org/tinygo/goenv"
 )
 
-// Link invokes a linker with the given name and arguments.
+// link invokes a linker with the given name and arguments.
 //
 // This version always runs the linker as an external command.
-func Link(dir, linker string, flags ...string) error {
+func link(linker string, flags ...string) error {
+	if cmdNames, ok := commands[linker]; ok {
+		return execCommand(cmdNames, flags...)
+	}
 	cmd := exec.Command(linker, flags...)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
-	cmd.Dir = dir
+	cmd.Dir = goenv.Get("TINYGOROOT")
 	return cmd.Run()
 }

builder/objcopy.go

@@ -0,0 +1,131 @@
+package builder
+
+import (
+	"debug/elf"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"github.com/marcinbor85/gohex"
+)
+
+// objcopyError is an error returned by functions that act like objcopy.
+type objcopyError struct {
+	Op  string
+	Err error
+}
+
+func (e objcopyError) Error() string {
+	if e.Err == nil {
+		return e.Op
+	}
+	return e.Op + ": " + e.Err.Error()
+}
+
+type progSlice []*elf.Prog
+
+func (s progSlice) Len() int           { return len(s) }
+func (s progSlice) Less(i, j int) bool { return s[i].Paddr < s[j].Paddr }
+func (s progSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// extractROM extracts a firmware image and the first load address from the
+// given ELF file. It tries to emulate the behavior of objcopy.
+func extractROM(path string) (uint64, []byte, error) {
+	f, err := elf.Open(path)
+	if err != nil {
+		return 0, nil, objcopyError{"failed to open ELF file to extract text segment", err}
+	}
+	defer f.Close()
+
+	// The GNU objcopy command does the following for firmware extraction (from
+	// the man page):
+	// > When objcopy generates a raw binary file, it will essentially produce a
+	// > memory dump of the contents of the input object file. All symbols and
+	// > relocation information will be discarded. The memory dump will start at
+	// > the load address of the lowest section copied into the output file.
+
+	// Find the lowest section address.
+	startAddr := ^uint64(0)
+	for _, section := range f.Sections {
+		if section.Type != elf.SHT_PROGBITS || section.Flags&elf.SHF_ALLOC == 0 {
+			continue
+		}
+		if section.Addr < startAddr {
+			startAddr = section.Addr
+		}
+	}
+
+	progs := make(progSlice, 0, 2)
+	for _, prog := range f.Progs {
+		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 {
+			continue
+		}
+		progs = append(progs, prog)
+	}
+	if len(progs) == 0 {
+		return 0, nil, objcopyError{"file does not contain ROM segments: " + path, nil}
+	}
+	sort.Sort(progs)
+
+	var rom []byte
+	for _, prog := range progs {
+		if prog.Paddr != progs[0].Paddr+uint64(len(rom)) {
+			return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+		}
+		data, err := ioutil.ReadAll(prog.Open())
+		if err != nil {
+			return 0, nil, objcopyError{"failed to extract segment from ELF file: " + path, err}
+		}
+		rom = append(rom, data...)
+	}
+	if progs[0].Paddr < startAddr {
+		// The lowest memory address is before the first section. This means
+		// that there is some extra data loaded at the start of the image that
+		// should be discarded.
+		// Example: ELF files where .text doesn't start at address 0 because
+		// there is a bootloader at the start.
+		return startAddr, rom[startAddr-progs[0].Paddr:], nil
+	} else {
+		return progs[0].Paddr, rom, nil
+	}
+}
+
+// objcopy converts an ELF file to a different (simpler) output file format:
+// .bin or .hex. It extracts only the .text section.
+func objcopy(infile, outfile string) error {
+	f, err := os.OpenFile(outfile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	// Read the .text segment.
+	addr, data, err := extractROM(infile)
+	if err != nil {
+		return err
+	}
+
+	// Write to the file, in the correct format.
+	switch filepath.Ext(outfile) {
+	case ".gba":
+		// The address is not stored in a .gba file.
+		_, err := f.Write(data)
+		return err
+	case ".bin":
+		// The address is not stored in a .bin file (therefore you
+		// should use .hex files in most cases).
+		_, err := f.Write(data)
+		return err
+	case ".hex":
+		mem := gohex.NewMemory()
+		err := mem.AddBinary(uint32(addr), data)
+		if err != nil {
+			return objcopyError{"failed to create .hex file", err}
+		}
+		mem.DumpIntelHex(f, 16) // TODO: handle error
+		return nil
+	default:
+		panic("unreachable")
+	}
+}

builder/sizes.go

@@ -1,4 +1,4 @@
-package main
+package builder
 
 import (
 	"debug/elf"
@@ -6,18 +6,18 @@ import (
 	"strings"
 )
 
-// Statistics about code size in a program.
-type ProgramSize struct {
-	Packages map[string]*PackageSize
-	Sum      *PackageSize
+// programSize contains size statistics per package of a compiled program.
+type programSize struct {
+	Packages map[string]*packageSize
+	Sum      *packageSize
 	Code     uint64
 	Data     uint64
 	BSS      uint64
 }
 
-// Return the list of package names (ProgramSize.Packages) sorted
-// alphabetically.
-func (ps *ProgramSize) SortedPackageNames() []string {
+// sortedPackageNames returns the list of package names (ProgramSize.Packages)
+// sorted alphabetically.
+func (ps *programSize) sortedPackageNames() []string {
 	names := make([]string, 0, len(ps.Packages))
 	for name := range ps.Packages {
 		names = append(names, name)
@@ -26,8 +26,9 @@ func (ps *ProgramSize) SortedPackageNames() []string {
 	return names
 }
 
-// The size of a package, calculated from the linked object file.
-type PackageSize struct {
+// packageSize contains the size of a package, calculated from the linked object
+// file.
+type packageSize struct {
 	Code   uint64
 	ROData uint64
 	Data   uint64
@@ -35,12 +36,12 @@ type PackageSize struct {
 }
 
 // Flash usage in regular microcontrollers.
-func (ps *PackageSize) Flash() uint64 {
+func (ps *packageSize) Flash() uint64 {
 	return ps.Code + ps.ROData + ps.Data
 }
 
 // Static RAM usage in regular microcontrollers.
-func (ps *PackageSize) RAM() uint64 {
+func (ps *packageSize) RAM() uint64 {
 	return ps.Data + ps.BSS
 }
 
@@ -64,8 +65,9 @@ func (l symbolList) Swap(i, j int) {
 	l[i], l[j] = l[j], l[i]
 }
 
-// Calculate program/data size breakdown of each package for a given ELF file.
-func Sizes(path string) (*ProgramSize, error) {
+// loadProgramSize calculate a program/data size breakdown of each package for a
+// given ELF file.
+func loadProgramSize(path string) (*programSize, error) {
 	file, err := elf.Open(path)
 	if err != nil {
 		return nil, err
@@ -115,7 +117,7 @@ func Sizes(path string) (*ProgramSize, error) {
 	}
 	sort.Sort(symbolList(symbols))
 
-	sizes := map[string]*PackageSize{}
+	sizes := map[string]*packageSize{}
 	var lastSymbolValue uint64
 	for _, symbol := range symbols {
 		symType := elf.ST_TYPE(symbol.Info)
@@ -129,7 +131,7 @@ func Sizes(path string) (*ProgramSize, error) {
 		}
 		pkgSize := sizes[pkgName]
 		if pkgSize == nil {
-			pkgSize = &PackageSize{}
+			pkgSize = &packageSize{}
 			sizes[pkgName] = pkgSize
 		}
 		if lastSymbolValue != symbol.Value || lastSymbolValue == 0 {
@@ -148,7 +150,7 @@ func Sizes(path string) (*ProgramSize, error) {
 		lastSymbolValue = symbol.Value
 	}
 
-	sum := &PackageSize{}
+	sum := &packageSize{}
 	for _, pkg := range sizes {
 		sum.Code += pkg.Code
 		sum.ROData += pkg.ROData
@@ -156,5 +158,5 @@ func Sizes(path string) (*ProgramSize, error) {
 		sum.BSS += pkg.BSS
 	}
 
-	return &ProgramSize{Packages: sizes, Code: sumCode, Data: sumData, BSS: sumBSS, Sum: sum}, nil
+	return &programSize{Packages: sizes, Code: sumCode, Data: sumData, BSS: sumBSS, Sum: sum}, nil
 }

builder/uf2.go

@@ -0,0 +1,151 @@
+package builder
+
+// This file converts firmware files from BIN to UF2 format before flashing.
+//
+// For more information about the UF2 firmware file format, please see:
+// https://github.com/Microsoft/uf2
+//
+//
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io/ioutil"
+	"strconv"
+)
+
+// convertELFFileToUF2File converts an ELF file to a UF2 file.
+func convertELFFileToUF2File(infile, outfile string, uf2FamilyID string) error {
+	// Read the .text segment.
+	targetAddress, data, err := extractROM(infile)
+	if err != nil {
+		return err
+	}
+
+	output, _, err := convertBinToUF2(data, uint32(targetAddress), uf2FamilyID)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(outfile, output, 0644)
+}
+
+// convertBinToUF2 converts the binary bytes in input to UF2 formatted data.
+func convertBinToUF2(input []byte, targetAddr uint32, uf2FamilyID string) ([]byte, int, error) {
+	blocks := split(input, 256)
+	output := make([]byte, 0)
+
+	bl, err := newUF2Block(targetAddr, uf2FamilyID)
+	if err != nil {
+		return nil, 0, err
+	}
+	bl.SetNumBlocks(len(blocks))
+
+	for i := 0; i < len(blocks); i++ {
+		bl.SetBlockNo(i)
+		bl.SetData(blocks[i])
+
+		output = append(output, bl.Bytes()...)
+		bl.IncrementAddress(bl.payloadSize)
+	}
+
+	return output, len(blocks), nil
+}
+
+const (
+	uf2MagicStart0 = 0x0A324655 // "UF2\n"
+	uf2MagicStart1 = 0x9E5D5157 // Randomly selected
+	uf2MagicEnd    = 0x0AB16F30 // Ditto
+)
+
+// uf2Block is the structure used for each UF2 code block sent to device.
+type uf2Block struct {
+	magicStart0 uint32
+	magicStart1 uint32
+	flags       uint32
+	targetAddr  uint32
+	payloadSize uint32
+	blockNo     uint32
+	numBlocks   uint32
+	familyID    uint32
+	data        []uint8
+	magicEnd    uint32
+}
+
+// newUF2Block returns a new uf2Block struct that has been correctly populated
+func newUF2Block(targetAddr uint32, uf2FamilyID string) (*uf2Block, error) {
+	var flags uint32
+	var familyID uint32
+	if uf2FamilyID != "" {
+		flags |= flagFamilyIDPresent
+		v, err := strconv.ParseUint(uf2FamilyID, 0, 32)
+		if err != nil {
+			return nil, err
+		}
+		familyID = uint32(v)
+	}
+	return &uf2Block{magicStart0: uf2MagicStart0,
+		magicStart1: uf2MagicStart1,
+		magicEnd:    uf2MagicEnd,
+		targetAddr:  targetAddr,
+		flags:       flags,
+		familyID:    familyID,
+		payloadSize: 256,
+		data:        make([]byte, 476),
+	}, nil
+}
+
+const (
+	flagFamilyIDPresent = 0x00002000
+)
+
+// Bytes converts the uf2Block to a slice of bytes that can be written to file.
+func (b *uf2Block) Bytes() []byte {
+	buf := bytes.NewBuffer(make([]byte, 0, 512))
+	binary.Write(buf, binary.LittleEndian, b.magicStart0)
+	binary.Write(buf, binary.LittleEndian, b.magicStart1)
+	binary.Write(buf, binary.LittleEndian, b.flags)
+	binary.Write(buf, binary.LittleEndian, b.targetAddr)
+	binary.Write(buf, binary.LittleEndian, b.payloadSize)
+	binary.Write(buf, binary.LittleEndian, b.blockNo)
+	binary.Write(buf, binary.LittleEndian, b.numBlocks)
+	binary.Write(buf, binary.LittleEndian, b.familyID)
+	binary.Write(buf, binary.LittleEndian, b.data)
+	binary.Write(buf, binary.LittleEndian, b.magicEnd)
+
+	return buf.Bytes()
+}
+
+// IncrementAddress moves the target address pointer forward by count bytes.
+func (b *uf2Block) IncrementAddress(count uint32) {
+	b.targetAddr += b.payloadSize
+}
+
+// SetData sets the data to be used for the current block.
+func (b *uf2Block) SetData(d []byte) {
+	b.data = make([]byte, 476)
+	copy(b.data[:], d)
+}
+
+// SetBlockNo sets the current block number to be used.
+func (b *uf2Block) SetBlockNo(bn int) {
+	b.blockNo = uint32(bn)
+}
+
+// SetNumBlocks sets the total number of blocks for this UF2 file.
+func (b *uf2Block) SetNumBlocks(total int) {
+	b.numBlocks = uint32(total)
+}
+
+// split splits a slice of bytes into a slice of byte slices of a specific size limit.
+func split(input []byte, limit int) [][]byte {
+	var block []byte
+	output := make([][]byte, 0, len(input)/limit+1)
+	for len(input) >= limit {
+		block, input = input[:limit], input[limit:]
+		output = append(output, block)
+	}
+	if len(input) > 0 {
+		output = append(output, input[:len(input)])
+	}
+	return output
+}

cgo/cgo_test.go

@@ -0,0 +1,129 @@
+package cgo
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"io/ioutil"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// Pass -update to go test to update the output of the test files.
+var flagUpdate = flag.Bool("update", false, "Update images based on test output.")
+
+func TestCGo(t *testing.T) {
+	var cflags = []string{"--target=armv6m-none-eabi"}
+
+	for _, name := range []string{"basic", "errors", "types", "flags", "const"} {
+		name := name // avoid a race condition
+		t.Run(name, func(t *testing.T) {
+			// Read the AST in memory.
+			path := filepath.Join("testdata", name+".go")
+			fset := token.NewFileSet()
+			f, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
+			if err != nil {
+				t.Fatal("could not parse Go source file:", err)
+			}
+
+			// Process the AST with CGo.
+			cgoAST, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)
+
+			// Check the AST for type errors.
+			var typecheckErrors []error
+			config := types.Config{
+				Error: func(err error) {
+					typecheckErrors = append(typecheckErrors, err)
+				},
+				Importer: simpleImporter{},
+				Sizes:    types.SizesFor("gccgo", "arm"),
+			}
+			_, err = config.Check("", fset, []*ast.File{f, cgoAST}, nil)
+			if err != nil && len(typecheckErrors) == 0 {
+				// Only report errors when no type errors are found (an
+				// unexpected condition).
+				t.Error(err)
+			}
+
+			// Store the (formatted) output in a buffer. Format it, so it
+			// becomes easier to read (and will hopefully change less with CGo
+			// changes).
+			buf := &bytes.Buffer{}
+			if len(cgoErrors) != 0 {
+				buf.WriteString("// CGo errors:\n")
+				for _, err := range cgoErrors {
+					buf.WriteString(formatDiagnostic(err))
+				}
+				buf.WriteString("\n")
+			}
+			if len(typecheckErrors) != 0 {
+				buf.WriteString("// Type checking errors after CGo processing:\n")
+				for _, err := range typecheckErrors {
+					buf.WriteString(formatDiagnostic(err))
+				}
+				buf.WriteString("\n")
+			}
+			err = format.Node(buf, fset, cgoAST)
+			if err != nil {
+				t.Errorf("could not write out CGo AST: %v", err)
+			}
+			actual := strings.Replace(string(buf.Bytes()), "\r\n", "\n", -1)
+
+			// Read the file with the expected output, to compare against.
+			outfile := filepath.Join("testdata", name+".out.go")
+			expectedBytes, err := ioutil.ReadFile(outfile)
+			if err != nil {
+				t.Fatalf("could not read expected output: %v", err)
+			}
+			expected := strings.Replace(string(expectedBytes), "\r\n", "\n", -1)
+
+			// Check whether the output is as expected.
+			if expected != actual {
+				// It is not. Test failed.
+				if *flagUpdate {
+					// Update the file with the expected data.
+					err := ioutil.WriteFile(outfile, []byte(actual), 0666)
+					if err != nil {
+						t.Error("could not write updated output file:", err)
+					}
+					return
+				}
+				t.Errorf("output did not match:\n%s", string(actual))
+			}
+		})
+	}
+}
+
+// simpleImporter implements the types.Importer interface, but only allows
+// importing the unsafe package.
+type simpleImporter struct {
+}
+
+// Import implements the Importer interface. For testing usage only: it only
+// supports importing the unsafe package.
+func (i simpleImporter) Import(path string) (*types.Package, error) {
+	switch path {
+	case "unsafe":
+		return types.Unsafe, nil
+	default:
+		return nil, fmt.Errorf("importer not implemented for package %s", path)
+	}
+}
+
+// formatDiagnostics formats the error message to be an indented comment. It
+// also fixes Windows path name issues (backward slashes).
+func formatDiagnostic(err error) string {
+	msg := err.Error()
+	if runtime.GOOS == "windows" {
+		// Fix Windows path slashes.
+		msg = strings.Replace(msg, "testdata\\", "testdata/", -1)
+	}
+	return "//     " + msg + "\n"
+}

cgo/const.go

@@ -0,0 +1,218 @@
+package cgo
+
+// This file implements a parser of a subset of the C language, just enough to
+// parse common #define statements to Go constant expressions.
+
+import (
+	"fmt"
+	"go/ast"
+	"go/scanner"
+	"go/token"
+	"strings"
+)
+
+// parseConst parses the given string as a C constant.
+func parseConst(pos token.Pos, fset *token.FileSet, value string) (ast.Expr, *scanner.Error) {
+	t := newTokenizer(pos, fset, value)
+	expr, err := parseConstExpr(t)
+	if t.token != token.EOF {
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: "unexpected token " + t.token.String(),
+		}
+	}
+	return expr, err
+}
+
+// parseConstExpr parses a stream of C tokens to a Go expression.
+func parseConstExpr(t *tokenizer) (ast.Expr, *scanner.Error) {
+	switch t.token {
+	case token.LPAREN:
+		lparen := t.pos
+		t.Next()
+		x, err := parseConstExpr(t)
+		if err != nil {
+			return nil, err
+		}
+		if t.token != token.RPAREN {
+			return nil, unexpectedToken(t, token.RPAREN)
+		}
+		expr := &ast.ParenExpr{
+			Lparen: lparen,
+			X:      x,
+			Rparen: t.pos,
+		}
+		t.Next()
+		return expr, nil
+	case token.INT, token.FLOAT, token.STRING, token.CHAR:
+		expr := &ast.BasicLit{
+			ValuePos: t.pos,
+			Kind:     t.token,
+			Value:    t.value,
+		}
+		t.Next()
+		return expr, nil
+	case token.IDENT:
+		expr := &ast.Ident{
+			NamePos: t.pos,
+			Name:    "C." + t.value,
+		}
+		t.Next()
+		return expr, nil
+	case token.EOF:
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: "empty constant",
+		}
+	default:
+		return nil, &scanner.Error{
+			Pos: t.fset.Position(t.pos),
+			Msg: fmt.Sprintf("unexpected token %s", t.token),
+		}
+	}
+}
+
+// unexpectedToken returns an error of the form "unexpected token FOO, expected
+// BAR".
+func unexpectedToken(t *tokenizer, expected token.Token) *scanner.Error {
+	return &scanner.Error{
+		Pos: t.fset.Position(t.pos),
+		Msg: fmt.Sprintf("unexpected token %s, expected %s", t.token, expected),
+	}
+}
+
+// tokenizer reads C source code and converts it to Go tokens.
+type tokenizer struct {
+	pos   token.Pos
+	fset  *token.FileSet
+	token token.Token
+	value string
+	buf   string
+}
+
+// newTokenizer initializes a new tokenizer, positioned at the first token in
+// the string.
+func newTokenizer(start token.Pos, fset *token.FileSet, buf string) *tokenizer {
+	t := &tokenizer{
+		pos:   start,
+		fset:  fset,
+		buf:   buf,
+		token: token.ILLEGAL,
+	}
+	t.Next() // Parse the first token.
+	return t
+}
+
+// Next consumes the next token in the stream. There is no return value, read
+// the next token from the pos, token and value properties.
+func (t *tokenizer) Next() {
+	t.pos += token.Pos(len(t.value))
+	for {
+		if len(t.buf) == 0 {
+			t.token = token.EOF
+			return
+		}
+		c := t.buf[0]
+		switch {
+		case c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v':
+			// Skip whitespace.
+			// Based on this source, not sure whether it represents C whitespace:
+			// https://en.cppreference.com/w/cpp/string/byte/isspace
+			t.pos++
+			t.buf = t.buf[1:]
+		case c == '(' || c == ')':
+			// Single-character tokens.
+			switch c {
+			case '(':
+				t.token = token.LPAREN
+			case ')':
+				t.token = token.RPAREN
+			}
+			t.value = t.buf[:1]
+			t.buf = t.buf[1:]
+			return
+		case c >= '0' && c <= '9':
+			// Numeric constant (int, float, etc.).
+			// Find the last non-numeric character.
+			tokenLen := len(t.buf)
+			hasDot := false
+			for i, c := range t.buf {
+				if c == '.' {
+					hasDot = true
+				}
+				if c >= '0' && c <= '9' || c == '.' || c == '_' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' {
+					tokenLen = i + 1
+				} else {
+					break
+				}
+			}
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			if hasDot {
+				// Integer constants are more complicated than this but this is
+				// a close approximation.
+				// https://en.cppreference.com/w/cpp/language/integer_literal
+				t.token = token.FLOAT
+				t.value = strings.TrimRight(t.value, "f")
+			} else {
+				t.token = token.INT
+				t.value = strings.TrimRight(t.value, "uUlL")
+			}
+			return
+		case c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' || c == '_':
+			// Identifier. Find all remaining tokens that are part of this
+			// identifier.
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if c >= '0' && c <= '9' || c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' || c == '_' {
+					tokenLen = i + 1
+				} else {
+					break
+				}
+			}
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			t.token = token.IDENT
+			return
+		case c == '"':
+			// String constant. Find the first '"' character that is not
+			// preceded by a backslash.
+			escape := false
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if i != 0 && c == '"' && !escape {
+					tokenLen = i + 1
+					break
+				}
+				if !escape {
+					escape = c == '\\'
+				}
+			}
+			t.token = token.STRING
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			return
+		case c == '\'':
+			// Char (rune) constant. Find the first '\'' character that is not
+			// preceded by a backslash.
+			escape := false
+			tokenLen := len(t.buf)
+			for i, c := range t.buf {
+				if i != 0 && c == '\'' && !escape {
+					tokenLen = i + 1
+					break
+				}
+				if !escape {
+					escape = c == '\\'
+				}
+			}
+			t.token = token.CHAR
+			t.value = t.buf[:tokenLen]
+			t.buf = t.buf[tokenLen:]
+			return
+		default:
+			t.token = token.ILLEGAL
+			return
+		}
+	}
+}

cgo/const_test.go

@@ -0,0 +1,60 @@
+package cgo
+
+import (
+	"bytes"
+	"go/format"
+	"go/token"
+	"strings"
+	"testing"
+)
+
+func TestParseConst(t *testing.T) {
+	// Test converting a C constant to a Go constant.
+	for _, tc := range []struct {
+		C  string
+		Go string
+	}{
+		{`5`, `5`},
+		{`(5)`, `(5)`},
+		{`(((5)))`, `(5)`},
+		{`)`, `error: 1:1: unexpected token )`},
+		{`5)`, `error: 1:2: unexpected token )`},
+		{"  \t)", `error: 1:4: unexpected token )`},
+		{`5.8f`, `5.8`},
+		{`foo`, `C.foo`},
+		{``, `error: 1:1: empty constant`}, // empty constants not allowed in Go
+		{`"foo"`, `"foo"`},
+		{`"a\\n"`, `"a\\n"`},
+		{`"a\n"`, `"a\n"`},
+		{`"a\""`, `"a\""`},
+		{`'a'`, `'a'`},
+		{`0b10`, `0b10`},
+		{`0x1234_5678`, `0x1234_5678`},
+		{`5 5`, `error: 1:3: unexpected token INT`}, // test for a bugfix
+	} {
+		fset := token.NewFileSet()
+		startPos := fset.AddFile("", -1, 1000).Pos(0)
+		expr, err := parseConst(startPos, fset, tc.C)
+		s := "<invalid>"
+		if err != nil {
+			if !strings.HasPrefix(tc.Go, "error: ") {
+				t.Errorf("expected value %#v for C constant %#v but got error %#v", tc.Go, tc.C, err.Error())
+				continue
+			}
+			s = "error: " + err.Error()
+		} else if expr != nil {
+			// Serialize the Go constant to a string, for more readable test
+			// cases.
+			buf := &bytes.Buffer{}
+			err := format.Node(buf, fset, expr)
+			if err != nil {
+				t.Errorf("could not format expr from C constant %#v: %v", tc.C, err)
+				continue
+			}
+			s = buf.String()
+		}
+		if s != tc.Go {
+			t.Errorf("C constant %#v was parsed to %#v while expecting %#v", tc.C, s, tc.Go)
+		}
+	}
+}

cgo/libclang.go

@@ -0,0 +1,776 @@
+package cgo
+
+// This file parses a fragment of C with libclang and stores the result for AST
+// modification. It does not touch the AST itself.
+
+import (
+	"fmt"
+	"go/ast"
+	"go/scanner"
+	"go/token"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unsafe"
+)
+
+/*
+#include <clang-c/Index.h> // if this fails, install libclang-9-dev
+#include <stdlib.h>
+#include <stdint.h>
+
+// This struct should be ABI-compatible on all platforms (uintptr_t has the same
+// alignment etc. as void*) but does not include void* pointers that are not
+// always real pointers.
+// The Go garbage collector assumes that all non-nil pointer-typed integers are
+// actually pointers. This is not always true, as data[1] often contains 0x1,
+// which is clearly not a valid pointer. Usually the GC won't catch this issue,
+// but occasionally it will leading to a crash with a vague error message.
+typedef struct {
+	enum CXCursorKind kind;
+	int xdata;
+	uintptr_t data[3];
+} GoCXCursor;
+
+// Forwarding functions. They are implemented in libclang_stubs.c and forward to
+// the real functions without doing anything else, thus they are entirely
+// compatible with the versions without tinygo_ prefix. The only difference is
+// the CXCursor type, which has been replaced with GoCXCursor.
+GoCXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu);
+unsigned tinygo_clang_visitChildren(GoCXCursor parent, CXCursorVisitor visitor, CXClientData client_data);
+CXString tinygo_clang_getCursorSpelling(GoCXCursor c);
+enum CXCursorKind tinygo_clang_getCursorKind(GoCXCursor c);
+CXType tinygo_clang_getCursorType(GoCXCursor c);
+GoCXCursor tinygo_clang_getTypeDeclaration(CXType t);
+CXType tinygo_clang_getTypedefDeclUnderlyingType(GoCXCursor c);
+CXType tinygo_clang_getCursorResultType(GoCXCursor c);
+int tinygo_clang_Cursor_getNumArguments(GoCXCursor c);
+GoCXCursor tinygo_clang_Cursor_getArgument(GoCXCursor c, unsigned i);
+CXSourceLocation tinygo_clang_getCursorLocation(GoCXCursor c);
+CXSourceRange tinygo_clang_getCursorExtent(GoCXCursor c);
+CXTranslationUnit tinygo_clang_Cursor_getTranslationUnit(GoCXCursor c);
+long long tinygo_clang_getEnumConstantDeclValue(GoCXCursor c);
+CXType tinygo_clang_getEnumDeclIntegerType(GoCXCursor c);
+unsigned tinygo_clang_Cursor_isBitField(GoCXCursor c);
+
+int tinygo_clang_globals_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+int tinygo_clang_struct_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+int tinygo_clang_enum_visitor(GoCXCursor c, GoCXCursor parent, CXClientData client_data);
+*/
+import "C"
+
+// storedRefs stores references to types, used for clang_visitChildren.
+var storedRefs refMap
+
+var diagnosticSeverity = [...]string{
+	C.CXDiagnostic_Ignored: "ignored",
+	C.CXDiagnostic_Note:    "note",
+	C.CXDiagnostic_Warning: "warning",
+	C.CXDiagnostic_Error:   "error",
+	C.CXDiagnostic_Fatal:   "fatal",
+}
+
+func (p *cgoPackage) parseFragment(fragment string, cflags []string, posFilename string, posLine int) {
+	index := C.clang_createIndex(0, 0)
+	defer C.clang_disposeIndex(index)
+
+	// pretend to be a .c file
+	filenameC := C.CString(posFilename + "!cgo.c")
+	defer C.free(unsafe.Pointer(filenameC))
+
+	// fix up error locations
+	fragment = fmt.Sprintf("# %d %#v\n", posLine+1, posFilename) + fragment
+
+	fragmentC := C.CString(fragment)
+	defer C.free(unsafe.Pointer(fragmentC))
+
+	unsavedFile := C.struct_CXUnsavedFile{
+		Filename: filenameC,
+		Length:   C.ulong(len(fragment)),
+		Contents: fragmentC,
+	}
+
+	// convert Go slice of strings to C array of strings.
+	cmdargsC := C.malloc(C.size_t(len(cflags)) * C.size_t(unsafe.Sizeof(uintptr(0))))
+	defer C.free(cmdargsC)
+	cmdargs := (*[1 << 16]*C.char)(cmdargsC)
+	for i, cflag := range cflags {
+		s := C.CString(cflag)
+		cmdargs[i] = s
+		defer C.free(unsafe.Pointer(s))
+	}
+
+	var unit C.CXTranslationUnit
+	errCode := C.clang_parseTranslationUnit2(
+		index,
+		filenameC,
+		(**C.char)(cmdargsC), C.int(len(cflags)), // command line args
+		&unsavedFile, 1, // unsaved files
+		C.CXTranslationUnit_DetailedPreprocessingRecord,
+		&unit)
+	if errCode != 0 {
+		// This is probably a bug in the usage of libclang.
+		panic("cgo: failed to parse source with libclang")
+	}
+	defer C.clang_disposeTranslationUnit(unit)
+
+	if numDiagnostics := int(C.clang_getNumDiagnostics(unit)); numDiagnostics != 0 {
+		addDiagnostic := func(diagnostic C.CXDiagnostic) {
+			spelling := getString(C.clang_getDiagnosticSpelling(diagnostic))
+			severity := diagnosticSeverity[C.clang_getDiagnosticSeverity(diagnostic)]
+			location := C.clang_getDiagnosticLocation(diagnostic)
+			pos := p.getClangLocationPosition(location, unit)
+			p.addError(pos, severity+": "+spelling)
+		}
+		for i := 0; i < numDiagnostics; i++ {
+			diagnostic := C.clang_getDiagnostic(unit, C.uint(i))
+			addDiagnostic(diagnostic)
+
+			// Child diagnostics (like notes on redefinitions).
+			diagnostics := C.clang_getChildDiagnostics(diagnostic)
+			for j := 0; j < int(C.clang_getNumDiagnosticsInSet(diagnostics)); j++ {
+				addDiagnostic(C.clang_getDiagnosticInSet(diagnostics, C.uint(j)))
+			}
+		}
+	}
+
+	ref := storedRefs.Put(p)
+	defer storedRefs.Remove(ref)
+	cursor := C.tinygo_clang_getTranslationUnitCursor(unit)
+	C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_globals_visitor), C.CXClientData(ref))
+}
+
+//export tinygo_clang_globals_visitor
+func tinygo_clang_globals_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	p := storedRefs.Get(unsafe.Pointer(client_data)).(*cgoPackage)
+	kind := C.tinygo_clang_getCursorKind(c)
+	pos := p.getCursorPosition(c)
+	switch kind {
+	case C.CXCursor_FunctionDecl:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		cursorType := C.tinygo_clang_getCursorType(c)
+		if C.clang_isFunctionTypeVariadic(cursorType) != 0 {
+			return C.CXChildVisit_Continue // not supported
+		}
+		numArgs := int(C.tinygo_clang_Cursor_getNumArguments(c))
+		fn := &functionInfo{
+			pos: pos,
+		}
+		p.functions[name] = fn
+		for i := 0; i < numArgs; i++ {
+			arg := C.tinygo_clang_Cursor_getArgument(c, C.uint(i))
+			argName := getString(C.tinygo_clang_getCursorSpelling(arg))
+			argType := C.clang_getArgType(cursorType, C.uint(i))
+			if argName == "" {
+				argName = "$" + strconv.Itoa(i)
+			}
+			fn.args = append(fn.args, paramInfo{
+				name:     argName,
+				typeExpr: p.makeASTType(argType, pos),
+			})
+		}
+		resultType := C.tinygo_clang_getCursorResultType(c)
+		if resultType.kind != C.CXType_Void {
+			fn.results = &ast.FieldList{
+				List: []*ast.Field{
+					&ast.Field{
+						Type: p.makeASTType(resultType, pos),
+					},
+				},
+			}
+		}
+	case C.CXCursor_StructDecl:
+		typ := C.tinygo_clang_getCursorType(c)
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols["struct_"+name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		p.makeASTType(typ, pos)
+	case C.CXCursor_TypedefDecl:
+		typedefType := C.tinygo_clang_getCursorType(c)
+		name := getString(C.clang_getTypedefName(typedefType))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		p.makeASTType(typedefType, pos)
+	case C.CXCursor_VarDecl:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		cursorType := C.tinygo_clang_getCursorType(c)
+		p.globals[name] = globalInfo{
+			typeExpr: p.makeASTType(cursorType, pos),
+			pos:      pos,
+		}
+	case C.CXCursor_MacroDefinition:
+		name := getString(C.tinygo_clang_getCursorSpelling(c))
+		if _, required := p.missingSymbols[name]; !required {
+			return C.CXChildVisit_Continue
+		}
+		sourceRange := C.tinygo_clang_getCursorExtent(c)
+		start := C.clang_getRangeStart(sourceRange)
+		end := C.clang_getRangeEnd(sourceRange)
+		var file, endFile C.CXFile
+		var startOffset, endOffset C.unsigned
+		C.clang_getExpansionLocation(start, &file, nil, nil, &startOffset)
+		if file == nil {
+			p.addError(pos, "internal error: could not find file where macro is defined")
+			break
+		}
+		C.clang_getExpansionLocation(end, &endFile, nil, nil, &endOffset)
+		if file != endFile {
+			p.addError(pos, "internal error: expected start and end location of a macro to be in the same file")
+			break
+		}
+		if startOffset > endOffset {
+			p.addError(pos, "internal error: start offset of macro is after end offset")
+			break
+		}
+
+		// read file contents and extract the relevant byte range
+		tu := C.tinygo_clang_Cursor_getTranslationUnit(c)
+		var size C.size_t
+		sourcePtr := C.clang_getFileContents(tu, file, &size)
+		if endOffset >= C.uint(size) {
+			p.addError(pos, "internal error: end offset of macro lies after end of file")
+			break
+		}
+		source := string(((*[1 << 28]byte)(unsafe.Pointer(sourcePtr)))[startOffset:endOffset:endOffset])
+		if !strings.HasPrefix(source, name) {
+			p.addError(pos, fmt.Sprintf("internal error: expected macro value to start with %#v, got %#v", name, source))
+			break
+		}
+		value := source[len(name):]
+		// Try to convert this #define into a Go constant expression.
+		expr, err := parseConst(pos+token.Pos(len(name)), p.fset, value)
+		if err != nil {
+			p.errors = append(p.errors, err)
+		}
+		if expr != nil {
+			// Parsing was successful.
+			p.constants[name] = constantInfo{expr, pos}
+		}
+	case C.CXCursor_EnumDecl:
+		// Visit all enums, because the fields may be used even when the enum
+		// type itself is not.
+		typ := C.tinygo_clang_getCursorType(c)
+		p.makeASTType(typ, pos)
+	}
+	return C.CXChildVisit_Continue
+}
+
+func getString(clangString C.CXString) (s string) {
+	rawString := C.clang_getCString(clangString)
+	s = C.GoString(rawString)
+	C.clang_disposeString(clangString)
+	return
+}
+
+// getCursorPosition returns a usable token.Pos from a libclang cursor.
+func (p *cgoPackage) getCursorPosition(cursor C.GoCXCursor) token.Pos {
+	return p.getClangLocationPosition(C.tinygo_clang_getCursorLocation(cursor), C.tinygo_clang_Cursor_getTranslationUnit(cursor))
+}
+
+// getClangLocationPosition returns a usable token.Pos based on a libclang
+// location and translation unit. If the file for this cursor has not been seen
+// before, it is read from libclang (which already has the file in memory) and
+// added to the token.FileSet.
+func (p *cgoPackage) getClangLocationPosition(location C.CXSourceLocation, tu C.CXTranslationUnit) token.Pos {
+	var file C.CXFile
+	var line C.unsigned
+	var column C.unsigned
+	var offset C.unsigned
+	C.clang_getExpansionLocation(location, &file, &line, &column, &offset)
+	if line == 0 || file == nil {
+		// Invalid token.
+		return token.NoPos
+	}
+	filename := getString(C.clang_getFileName(file))
+	if _, ok := p.tokenFiles[filename]; !ok {
+		// File has not been seen before in this package, add line information
+		// now by reading the file from libclang.
+		var size C.size_t
+		sourcePtr := C.clang_getFileContents(tu, file, &size)
+		source := ((*[1 << 28]byte)(unsafe.Pointer(sourcePtr)))[:size:size]
+		lines := []int{0}
+		for i := 0; i < len(source)-1; i++ {
+			if source[i] == '\n' {
+				lines = append(lines, i+1)
+			}
+		}
+		f := p.fset.AddFile(filename, -1, int(size))
+		f.SetLines(lines)
+		p.tokenFiles[filename] = f
+	}
+	positionFile := p.tokenFiles[filename]
+
+	// Check for alternative line/column information (set with a line directive).
+	var filename2String C.CXString
+	var line2 C.unsigned
+	var column2 C.unsigned
+	C.clang_getPresumedLocation(location, &filename2String, &line2, &column2)
+	filename2 := getString(filename2String)
+	if filename2 != filename || line2 != line || column2 != column {
+		// The location was changed with a preprocessor directive.
+		// TODO: this only works for locations that are added in order. Adding
+		// line/column info to a file that already has line/column info after
+		// the given offset is ignored.
+		positionFile.AddLineColumnInfo(int(offset), filename2, int(line2), int(column2))
+	}
+
+	return positionFile.Pos(int(offset))
+}
+
+// addError is a utility function to add an error to the list of errors. It will
+// convert the token position to a line/column position first, and call
+// addErrorAt.
+func (p *cgoPackage) addError(pos token.Pos, msg string) {
+	p.addErrorAt(p.fset.PositionFor(pos, true), msg)
+}
+
+// addErrorAfter is like addError, but adds the text `after` to the source
+// location.
+func (p *cgoPackage) addErrorAfter(pos token.Pos, after, msg string) {
+	position := p.fset.PositionFor(pos, true)
+	lines := strings.Split(after, "\n")
+	if len(lines) != 1 {
+		// Adjust lines.
+		// For why we can't just do pos+token.Pos(len(after)), see:
+		// https://github.com/golang/go/issues/35803
+		position.Line += len(lines) - 1
+		position.Column = len(lines[len(lines)-1]) + 1
+	} else {
+		position.Column += len(after)
+	}
+	p.addErrorAt(position, msg)
+}
+
+// addErrorAt is a utility function to add an error to the list of errors.
+func (p *cgoPackage) addErrorAt(position token.Position, msg string) {
+	if filepath.IsAbs(position.Filename) {
+		// Relative paths for readability, like other Go parser errors.
+		relpath, err := filepath.Rel(p.dir, position.Filename)
+		if err == nil {
+			position.Filename = relpath
+		}
+	}
+	p.errors = append(p.errors, scanner.Error{
+		Pos: position,
+		Msg: msg,
+	})
+}
+
+// makeASTType return the ast.Expr for the given libclang type. In other words,
+// it converts a libclang type to a type in the Go AST.
+func (p *cgoPackage) makeASTType(typ C.CXType, pos token.Pos) ast.Expr {
+	var typeName string
+	switch typ.kind {
+	case C.CXType_Char_S, C.CXType_Char_U:
+		typeName = "C.char"
+	case C.CXType_SChar:
+		typeName = "C.schar"
+	case C.CXType_UChar:
+		typeName = "C.uchar"
+	case C.CXType_Short:
+		typeName = "C.short"
+	case C.CXType_UShort:
+		typeName = "C.ushort"
+	case C.CXType_Int:
+		typeName = "C.int"
+	case C.CXType_UInt:
+		typeName = "C.uint"
+	case C.CXType_Long:
+		typeName = "C.long"
+	case C.CXType_ULong:
+		typeName = "C.ulong"
+	case C.CXType_LongLong:
+		typeName = "C.longlong"
+	case C.CXType_ULongLong:
+		typeName = "C.ulonglong"
+	case C.CXType_Bool:
+		typeName = "bool"
+	case C.CXType_Float, C.CXType_Double, C.CXType_LongDouble:
+		switch C.clang_Type_getSizeOf(typ) {
+		case 4:
+			typeName = "float32"
+		case 8:
+			typeName = "float64"
+		default:
+			// Don't do anything, rely on the fallback code to show a somewhat
+			// sensible error message like "undeclared name: C.long double".
+		}
+	case C.CXType_Complex:
+		switch C.clang_Type_getSizeOf(typ) {
+		case 8:
+			typeName = "complex64"
+		case 16:
+			typeName = "complex128"
+		}
+	case C.CXType_Pointer:
+		pointeeType := C.clang_getPointeeType(typ)
+		if pointeeType.kind == C.CXType_Void {
+			// void* type is translated to Go as unsafe.Pointer
+			return &ast.SelectorExpr{
+				X: &ast.Ident{
+					NamePos: pos,
+					Name:    "unsafe",
+				},
+				Sel: &ast.Ident{
+					NamePos: pos,
+					Name:    "Pointer",
+				},
+			}
+		}
+		return &ast.StarExpr{
+			Star: pos,
+			X:    p.makeASTType(pointeeType, pos),
+		}
+	case C.CXType_ConstantArray:
+		return &ast.ArrayType{
+			Lbrack: pos,
+			Len: &ast.BasicLit{
+				ValuePos: pos,
+				Kind:     token.INT,
+				Value:    strconv.FormatInt(int64(C.clang_getArraySize(typ)), 10),
+			},
+			Elt: p.makeASTType(C.clang_getElementType(typ), pos),
+		}
+	case C.CXType_FunctionProto:
+		// Be compatible with gc, which uses the *[0]byte type for function
+		// pointer types.
+		// Return type [0]byte because this is a function type, not a pointer to
+		// this function type.
+		return &ast.ArrayType{
+			Lbrack: pos,
+			Len: &ast.BasicLit{
+				ValuePos: pos,
+				Kind:     token.INT,
+				Value:    "0",
+			},
+			Elt: &ast.Ident{
+				NamePos: pos,
+				Name:    "byte",
+			},
+		}
+	case C.CXType_Typedef:
+		name := getString(C.clang_getTypedefName(typ))
+		if _, ok := p.typedefs[name]; !ok {
+			p.typedefs[name] = nil // don't recurse
+			c := C.tinygo_clang_getTypeDeclaration(typ)
+			underlyingType := C.tinygo_clang_getTypedefDeclUnderlyingType(c)
+			expr := p.makeASTType(underlyingType, pos)
+			if strings.HasPrefix(name, "_Cgo_") {
+				expr := expr.(*ast.Ident)
+				typeSize := C.clang_Type_getSizeOf(underlyingType)
+				switch expr.Name {
+				case "C.char":
+					if typeSize != 1 {
+						// This happens for some very special purpose architectures
+						// (DSPs etc.) that are not currently targeted.
+						// https://www.embecosm.com/2017/04/18/non-8-bit-char-support-in-clang-and-llvm/
+						p.addError(pos, fmt.Sprintf("unknown char width: %d", typeSize))
+					}
+					switch underlyingType.kind {
+					case C.CXType_Char_S:
+						expr.Name = "int8"
+					case C.CXType_Char_U:
+						expr.Name = "uint8"
+					}
+				case "C.schar", "C.short", "C.int", "C.long", "C.longlong":
+					switch typeSize {
+					case 1:
+						expr.Name = "int8"
+					case 2:
+						expr.Name = "int16"
+					case 4:
+						expr.Name = "int32"
+					case 8:
+						expr.Name = "int64"
+					}
+				case "C.uchar", "C.ushort", "C.uint", "C.ulong", "C.ulonglong":
+					switch typeSize {
+					case 1:
+						expr.Name = "uint8"
+					case 2:
+						expr.Name = "uint16"
+					case 4:
+						expr.Name = "uint32"
+					case 8:
+						expr.Name = "uint64"
+					}
+				}
+			}
+			p.typedefs[name] = &typedefInfo{
+				typeExpr: expr,
+				pos:      pos,
+			}
+		}
+		return &ast.Ident{
+			NamePos: pos,
+			Name:    "C." + name,
+		}
+	case C.CXType_Elaborated:
+		underlying := C.clang_Type_getNamedType(typ)
+		switch underlying.kind {
+		case C.CXType_Record:
+			return p.makeASTType(underlying, pos)
+		case C.CXType_Enum:
+			return p.makeASTType(underlying, pos)
+		default:
+			typeKindSpelling := getString(C.clang_getTypeKindSpelling(underlying.kind))
+			p.addError(pos, fmt.Sprintf("unknown elaborated type (libclang type kind %s)", typeKindSpelling))
+			typeName = "<unknown>"
+		}
+	case C.CXType_Record:
+		cursor := C.tinygo_clang_getTypeDeclaration(typ)
+		name := getString(C.tinygo_clang_getCursorSpelling(cursor))
+		var cgoRecordPrefix string
+		switch C.tinygo_clang_getCursorKind(cursor) {
+		case C.CXCursor_StructDecl:
+			cgoRecordPrefix = "struct_"
+		case C.CXCursor_UnionDecl:
+			cgoRecordPrefix = "union_"
+		default:
+			// makeASTRecordType will create an appropriate error.
+			cgoRecordPrefix = "record_"
+		}
+		if name == "" {
+			// Anonymous record, probably inside a typedef.
+			typeInfo := p.makeASTRecordType(cursor, pos)
+			if typeInfo.bitfields != nil || typeInfo.unionSize != 0 {
+				// This record is a union or is a struct with bitfields, so we
+				// have to declare it as a named type (for getters/setters to
+				// work).
+				p.anonStructNum++
+				cgoName := cgoRecordPrefix + strconv.Itoa(p.anonStructNum)
+				p.elaboratedTypes[cgoName] = typeInfo
+				return &ast.Ident{
+					NamePos: pos,
+					Name:    "C." + cgoName,
+				}
+			}
+			return typeInfo.typeExpr
+		} else {
+			cgoName := cgoRecordPrefix + name
+			if _, ok := p.elaboratedTypes[cgoName]; !ok {
+				p.elaboratedTypes[cgoName] = nil // predeclare (to avoid endless recursion)
+				p.elaboratedTypes[cgoName] = p.makeASTRecordType(cursor, pos)
+			}
+			return &ast.Ident{
+				NamePos: pos,
+				Name:    "C." + cgoName,
+			}
+		}
+	case C.CXType_Enum:
+		cursor := C.tinygo_clang_getTypeDeclaration(typ)
+		name := getString(C.tinygo_clang_getCursorSpelling(cursor))
+		underlying := C.tinygo_clang_getEnumDeclIntegerType(cursor)
+		if name == "" {
+			// anonymous enum
+			ref := storedRefs.Put(p)
+			defer storedRefs.Remove(ref)
+			C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_enum_visitor), C.CXClientData(ref))
+			return p.makeASTType(underlying, pos)
+		} else {
+			// named enum
+			if _, ok := p.enums[name]; !ok {
+				ref := storedRefs.Put(p)
+				defer storedRefs.Remove(ref)
+				C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_enum_visitor), C.CXClientData(ref))
+				p.enums[name] = enumInfo{
+					typeExpr: p.makeASTType(underlying, pos),
+					pos:      pos,
+				}
+			}
+			return &ast.Ident{
+				NamePos: pos,
+				Name:    "C.enum_" + name,
+			}
+		}
+	}
+	if typeName == "" {
+		// Report this as an error.
+		typeSpelling := getString(C.clang_getTypeSpelling(typ))
+		typeKindSpelling := getString(C.clang_getTypeKindSpelling(typ.kind))
+		p.addError(pos, fmt.Sprintf("unknown C type: %v (libclang type kind %s)", typeSpelling, typeKindSpelling))
+		typeName = "C.<unknown>"
+	}
+	return &ast.Ident{
+		NamePos: pos,
+		Name:    typeName,
+	}
+}
+
+// makeASTRecordType parses a C record (struct or union) and translates it into
+// a Go struct type.
+func (p *cgoPackage) makeASTRecordType(cursor C.GoCXCursor, pos token.Pos) *elaboratedTypeInfo {
+	fieldList := &ast.FieldList{
+		Opening: pos,
+		Closing: pos,
+	}
+	var bitfieldList []bitfieldInfo
+	inBitfield := false
+	bitfieldNum := 0
+	ref := storedRefs.Put(struct {
+		fieldList    *ast.FieldList
+		pkg          *cgoPackage
+		inBitfield   *bool
+		bitfieldNum  *int
+		bitfieldList *[]bitfieldInfo
+	}{fieldList, p, &inBitfield, &bitfieldNum, &bitfieldList})
+	defer storedRefs.Remove(ref)
+	C.tinygo_clang_visitChildren(cursor, C.CXCursorVisitor(C.tinygo_clang_struct_visitor), C.CXClientData(ref))
+	renameFieldKeywords(fieldList)
+	switch C.tinygo_clang_getCursorKind(cursor) {
+	case C.CXCursor_StructDecl:
+		return &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+				Fields: fieldList,
+			},
+			pos:       pos,
+			bitfields: bitfieldList,
+		}
+	case C.CXCursor_UnionDecl:
+		typeInfo := &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+				Fields: fieldList,
+			},
+			pos:       pos,
+			bitfields: bitfieldList,
+		}
+		if len(fieldList.List) <= 1 {
+			// Useless union, treat it as a regular struct.
+			return typeInfo
+		}
+		if bitfieldList != nil {
+			// This is valid C... but please don't do this.
+			p.addError(pos, "bitfield in a union is not supported")
+		}
+		typ := C.tinygo_clang_getCursorType(cursor)
+		alignInBytes := int64(C.clang_Type_getAlignOf(typ))
+		sizeInBytes := int64(C.clang_Type_getSizeOf(typ))
+		if sizeInBytes == 0 {
+			p.addError(pos, "zero-length union is not supported")
+		}
+		typeInfo.unionSize = sizeInBytes
+		typeInfo.unionAlign = alignInBytes
+		return typeInfo
+	default:
+		cursorKind := C.tinygo_clang_getCursorKind(cursor)
+		cursorKindSpelling := getString(C.clang_getCursorKindSpelling(cursorKind))
+		p.addError(pos, fmt.Sprintf("expected StructDecl or UnionDecl, not %s", cursorKindSpelling))
+		return &elaboratedTypeInfo{
+			typeExpr: &ast.StructType{
+				Struct: pos,
+			},
+			pos: pos,
+		}
+	}
+}
+
+//export tinygo_clang_struct_visitor
+func tinygo_clang_struct_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	passed := storedRefs.Get(unsafe.Pointer(client_data)).(struct {
+		fieldList    *ast.FieldList
+		pkg          *cgoPackage
+		inBitfield   *bool
+		bitfieldNum  *int
+		bitfieldList *[]bitfieldInfo
+	})
+	fieldList := passed.fieldList
+	p := passed.pkg
+	inBitfield := passed.inBitfield
+	bitfieldNum := passed.bitfieldNum
+	bitfieldList := passed.bitfieldList
+	pos := p.getCursorPosition(c)
+	switch cursorKind := C.tinygo_clang_getCursorKind(c); cursorKind {
+	case C.CXCursor_FieldDecl:
+		// Expected. This is a regular field.
+	case C.CXCursor_StructDecl, C.CXCursor_UnionDecl:
+		// Ignore. The next field will be the struct/union itself.
+		return C.CXChildVisit_Continue
+	default:
+		cursorKindSpelling := getString(C.clang_getCursorKindSpelling(cursorKind))
+		p.addError(pos, fmt.Sprintf("expected FieldDecl in struct or union, not %s", cursorKindSpelling))
+		return C.CXChildVisit_Continue
+	}
+	name := getString(C.tinygo_clang_getCursorSpelling(c))
+	if name == "" {
+		// Assume this is a bitfield of 0 bits.
+		// Warning: this is not necessarily true!
+		return C.CXChildVisit_Continue
+	}
+	typ := C.tinygo_clang_getCursorType(c)
+	field := &ast.Field{
+		Type: p.makeASTType(typ, p.getCursorPosition(c)),
+	}
+	offsetof := int64(C.clang_Type_getOffsetOf(C.tinygo_clang_getCursorType(parent), C.CString(name)))
+	alignOf := int64(C.clang_Type_getAlignOf(typ) * 8)
+	bitfieldOffset := offsetof % alignOf
+	if bitfieldOffset != 0 {
+		if C.tinygo_clang_Cursor_isBitField(c) != 1 {
+			p.addError(pos, "expected a bitfield")
+			return C.CXChildVisit_Continue
+		}
+		if !*inBitfield {
+			*bitfieldNum++
+		}
+		bitfieldName := "__bitfield_" + strconv.Itoa(*bitfieldNum)
+		prevField := fieldList.List[len(fieldList.List)-1]
+		if !*inBitfield {
+			// The previous element also was a bitfield, but wasn't noticed
+			// then. Add it now.
+			*inBitfield = true
+			*bitfieldList = append(*bitfieldList, bitfieldInfo{
+				field:    prevField,
+				name:     prevField.Names[0].Name,
+				startBit: 0,
+				pos:      prevField.Names[0].NamePos,
+			})
+			prevField.Names[0].Name = bitfieldName
+			prevField.Names[0].Obj.Name = bitfieldName
+		}
+		prevBitfield := &(*bitfieldList)[len(*bitfieldList)-1]
+		prevBitfield.endBit = bitfieldOffset
+		*bitfieldList = append(*bitfieldList, bitfieldInfo{
+			field:    prevField,
+			name:     name,
+			startBit: bitfieldOffset,
+			pos:      pos,
+		})
+		return C.CXChildVisit_Continue
+	}
+	*inBitfield = false
+	field.Names = []*ast.Ident{
+		&ast.Ident{
+			NamePos: pos,
+			Name:    name,
+			Obj: &ast.Object{
+				Kind: ast.Var,
+				Name: name,
+				Decl: field,
+			},
+		},
+	}
+	fieldList.List = append(fieldList.List, field)
+	return C.CXChildVisit_Continue
+}
+
+//export tinygo_clang_enum_visitor
+func tinygo_clang_enum_visitor(c, parent C.GoCXCursor, client_data C.CXClientData) C.int {
+	p := storedRefs.Get(unsafe.Pointer(client_data)).(*cgoPackage)
+	name := getString(C.tinygo_clang_getCursorSpelling(c))
+	pos := p.getCursorPosition(c)
+	value := C.tinygo_clang_getEnumConstantDeclValue(c)
+	p.constants[name] = constantInfo{
+		expr: &ast.BasicLit{pos, token.INT, strconv.FormatInt(int64(value), 10)},
+		pos:  pos,
+	}
+	return C.CXChildVisit_Continue
+}

cgo/libclang_config.go

@@ -0,0 +1,13 @@
+// +build !byollvm
+
+package cgo
+
+/*
+#cgo linux  CFLAGS: -I/usr/lib/llvm-9/include
+#cgo darwin CFLAGS: -I/usr/local/opt/llvm@9/include
+#cgo freebsd CFLAGS: -I/usr/local/llvm90/include
+#cgo linux  LDFLAGS: -L/usr/lib/llvm-9/lib -lclang
+#cgo darwin LDFLAGS: -L/usr/local/opt/llvm@9/lib -lclang -lffi
+#cgo freebsd LDFLAGS: -L/usr/local/llvm90/lib -lclang
+*/
+import "C"

cgo/libclang_stubs.c

@@ -0,0 +1,70 @@
+
+// This file implements some small trampoline functions. The signatures
+// are slightly different from the ones defined in libclang.go, but they
+// should be ABI compatible.
+
+#include <clang-c/Index.h> // if this fails, install libclang-9-dev
+
+CXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu) {
+	return clang_getTranslationUnitCursor(tu);
+}
+
+unsigned tinygo_clang_visitChildren(CXCursor parent, CXCursorVisitor visitor, CXClientData client_data) {
+	return clang_visitChildren(parent, visitor, client_data);
+}
+
+CXString tinygo_clang_getCursorSpelling(CXCursor c) {
+	return clang_getCursorSpelling(c);
+}
+
+enum CXCursorKind tinygo_clang_getCursorKind(CXCursor c) {
+	return clang_getCursorKind(c);
+}
+
+CXType tinygo_clang_getCursorType(CXCursor c) {
+	return clang_getCursorType(c);
+}
+
+CXCursor tinygo_clang_getTypeDeclaration(CXType t) {
+	return clang_getTypeDeclaration(t);
+}
+
+CXType tinygo_clang_getTypedefDeclUnderlyingType(CXCursor c) {
+	return clang_getTypedefDeclUnderlyingType(c);
+}
+
+CXType tinygo_clang_getCursorResultType(CXCursor c) {
+	return clang_getCursorResultType(c);
+}
+
+int tinygo_clang_Cursor_getNumArguments(CXCursor c) {
+	return clang_Cursor_getNumArguments(c);
+}
+
+CXCursor tinygo_clang_Cursor_getArgument(CXCursor c, unsigned i) {
+	return clang_Cursor_getArgument(c, i);
+}
+
+CXSourceLocation tinygo_clang_getCursorLocation(CXCursor c) {
+	return clang_getCursorLocation(c);
+}
+
+CXSourceRange tinygo_clang_getCursorExtent(CXCursor c) {
+	return clang_getCursorExtent(c);
+}
+
+CXTranslationUnit tinygo_clang_Cursor_getTranslationUnit(CXCursor c) {
+	return clang_Cursor_getTranslationUnit(c);
+}
+
+long long tinygo_clang_getEnumConstantDeclValue(CXCursor c) {
+	return clang_getEnumConstantDeclValue(c);
+}
+
+CXType tinygo_clang_getEnumDeclIntegerType(CXCursor c) {
+	return clang_getEnumDeclIntegerType(c);
+}
+
+unsigned tinygo_clang_Cursor_isBitField(CXCursor c) {
+	return clang_Cursor_isBitField(c);
+}

cgo/security.go

@@ -0,0 +1,301 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file has been copied from the Go 1.13 release tree.
+
+// Checking of compiler and linker flags.
+// We must avoid flags like -fplugin=, which can allow
+// arbitrary code execution during the build.
+// Do not make changes here without carefully
+// considering the implications.
+// (That's why the code is isolated in a file named security.go.)
+//
+// Note that -Wl,foo means split foo on commas and pass to
+// the linker, so that -Wl,-foo,bar means pass -foo bar to
+// the linker. Similarly -Wa,foo for the assembler and so on.
+// If any of these are permitted, the wildcard portion must
+// disallow commas.
+//
+// Note also that GNU binutils accept any argument @foo
+// as meaning "read more flags from the file foo", so we must
+// guard against any command-line argument beginning with @,
+// even things like "-I @foo".
+// We use safeArg (which is even more conservative)
+// to reject these.
+//
+// Even worse, gcc -I@foo (one arg) turns into cc1 -I @foo (two args),
+// so although gcc doesn't expand the @foo, cc1 will.
+// So out of paranoia, we reject @ at the beginning of every
+// flag argument that might be split into its own argument.
+
+package cgo
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+)
+
+var re = regexp.MustCompile
+
+var validCompilerFlags = []*regexp.Regexp{
+	re(`-D([A-Za-z_].*)`),
+	re(`-F([^@\-].*)`),
+	re(`-I([^@\-].*)`),
+	re(`-O`),
+	re(`-O([^@\-].*)`),
+	re(`-W`),
+	re(`-W([^@,]+)`), // -Wall but not -Wa,-foo.
+	re(`-Wa,-mbig-obj`),
+	re(`-Wp,-D([A-Za-z_].*)`),
+	re(`-ansi`),
+	re(`-f(no-)?asynchronous-unwind-tables`),
+	re(`-f(no-)?blocks`),
+	re(`-f(no-)builtin-[a-zA-Z0-9_]*`),
+	re(`-f(no-)?common`),
+	re(`-f(no-)?constant-cfstrings`),
+	re(`-fdiagnostics-show-note-include-stack`),
+	re(`-f(no-)?eliminate-unused-debug-types`),
+	re(`-f(no-)?exceptions`),
+	re(`-f(no-)?fast-math`),
+	re(`-f(no-)?inline-functions`),
+	re(`-finput-charset=([^@\-].*)`),
+	re(`-f(no-)?fat-lto-objects`),
+	re(`-f(no-)?keep-inline-dllexport`),
+	re(`-f(no-)?lto`),
+	re(`-fmacro-backtrace-limit=(.+)`),
+	re(`-fmessage-length=(.+)`),
+	re(`-f(no-)?modules`),
+	re(`-f(no-)?objc-arc`),
+	re(`-f(no-)?objc-nonfragile-abi`),
+	re(`-f(no-)?objc-legacy-dispatch`),
+	re(`-f(no-)?omit-frame-pointer`),
+	re(`-f(no-)?openmp(-simd)?`),
+	re(`-f(no-)?permissive`),
+	re(`-f(no-)?(pic|PIC|pie|PIE)`),
+	re(`-f(no-)?plt`),
+	re(`-f(no-)?rtti`),
+	re(`-f(no-)?split-stack`),
+	re(`-f(no-)?stack-(.+)`),
+	re(`-f(no-)?strict-aliasing`),
+	re(`-f(un)signed-char`),
+	re(`-f(no-)?use-linker-plugin`), // safe if -B is not used; we don't permit -B
+	re(`-f(no-)?visibility-inlines-hidden`),
+	re(`-fsanitize=(.+)`),
+	re(`-ftemplate-depth-(.+)`),
+	re(`-fvisibility=(.+)`),
+	re(`-g([^@\-].*)?`),
+	re(`-m32`),
+	re(`-m64`),
+	re(`-m(abi|arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-m(no-)?v?aes`),
+	re(`-marm`),
+	re(`-m(no-)?avx[0-9a-z]*`),
+	re(`-mfloat-abi=([^@\-].*)`),
+	re(`-mfpmath=[0-9a-z,+]*`),
+	re(`-m(no-)?avx[0-9a-z.]*`),
+	re(`-m(no-)?ms-bitfields`),
+	re(`-m(no-)?stack-(.+)`),
+	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
+	re(`-mtvos-simulator-version-min=(.+)`),
+	re(`-mtvos-version-min=(.+)`),
+	re(`-mwatchos-simulator-version-min=(.+)`),
+	re(`-mwatchos-version-min=(.+)`),
+	re(`-mnop-fun-dllimport`),
+	re(`-m(no-)?sse[0-9.]*`),
+	re(`-m(no-)?ssse3`),
+	re(`-mthumb(-interwork)?`),
+	re(`-mthreads`),
+	re(`-mwindows`),
+	re(`--param=ssp-buffer-size=[0-9]*`),
+	re(`-pedantic(-errors)?`),
+	re(`-pipe`),
+	re(`-pthread`),
+	re(`-?-std=([^@\-].*)`),
+	re(`-?-stdlib=([^@\-].*)`),
+	re(`--sysroot=([^@\-].*)`),
+	re(`-w`),
+	re(`-x([^@\-].*)`),
+	re(`-v`),
+}
+
+var validCompilerFlagsWithNextArg = []string{
+	"-arch",
+	"-D",
+	"-I",
+	"-framework",
+	"-isysroot",
+	"-isystem",
+	"--sysroot",
+	"-target",
+	"-x",
+}
+
+var validLinkerFlags = []*regexp.Regexp{
+	re(`-F([^@\-].*)`),
+	re(`-l([^@\-].*)`),
+	re(`-L([^@\-].*)`),
+	re(`-O`),
+	re(`-O([^@\-].*)`),
+	re(`-f(no-)?(pic|PIC|pie|PIE)`),
+	re(`-f(no-)?openmp(-simd)?`),
+	re(`-fsanitize=([^@\-].*)`),
+	re(`-flat_namespace`),
+	re(`-g([^@\-].*)?`),
+	re(`-headerpad_max_install_names`),
+	re(`-m(abi|arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-mfloat-abi=([^@\-].*)`),
+	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
+	re(`-mthreads`),
+	re(`-mwindows`),
+	re(`-(pic|PIC|pie|PIE)`),
+	re(`-pthread`),
+	re(`-rdynamic`),
+	re(`-shared`),
+	re(`-?-static([-a-z0-9+]*)`),
+	re(`-?-stdlib=([^@\-].*)`),
+	re(`-v`),
+
+	// Note that any wildcards in -Wl need to exclude comma,
+	// since -Wl splits its argument at commas and passes
+	// them all to the linker uninterpreted. Allowing comma
+	// in a wildcard would allow tunnelling arbitrary additional
+	// linker arguments through one of these.
+	re(`-Wl,--(no-)?allow-multiple-definition`),
+	re(`-Wl,--(no-)?allow-shlib-undefined`),
+	re(`-Wl,--(no-)?as-needed`),
+	re(`-Wl,-Bdynamic`),
+	re(`-Wl,-berok`),
+	re(`-Wl,-Bstatic`),
+	re(`-WL,-O([^@,\-][^,]*)?`),
+	re(`-Wl,-d[ny]`),
+	re(`-Wl,--disable-new-dtags`),
+	re(`-Wl,-e[=,][a-zA-Z0-9]*`),
+	re(`-Wl,--enable-new-dtags`),
+	re(`-Wl,--end-group`),
+	re(`-Wl,--(no-)?export-dynamic`),
+	re(`-Wl,-framework,[^,@\-][^,]+`),
+	re(`-Wl,-headerpad_max_install_names`),
+	re(`-Wl,--no-undefined`),
+	re(`-Wl,-R([^@\-][^,@]*$)`),
+	re(`-Wl,--just-symbols[=,]([^,@\-][^,@]+)`),
+	re(`-Wl,-rpath(-link)?[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-s`),
+	re(`-Wl,-search_paths_first`),
+	re(`-Wl,-sectcreate,([^,@\-][^,]+),([^,@\-][^,]+),([^,@\-][^,]+)`),
+	re(`-Wl,--start-group`),
+	re(`-Wl,-?-static`),
+	re(`-Wl,-?-subsystem,(native|windows|console|posix|xbox)`),
+	re(`-Wl,-syslibroot[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-undefined[=,]([^,@\-][^,]+)`),
+	re(`-Wl,-?-unresolved-symbols=[^,]+`),
+	re(`-Wl,--(no-)?warn-([^,]+)`),
+	re(`-Wl,-z,(no)?execstack`),
+	re(`-Wl,-z,relro`),
+
+	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
+	re(`\./.*\.(a|o|obj|dll|dylib|so)`),
+}
+
+var validLinkerFlagsWithNextArg = []string{
+	"-arch",
+	"-F",
+	"-l",
+	"-L",
+	"-framework",
+	"-isysroot",
+	"--sysroot",
+	"-target",
+	"-Wl,-framework",
+	"-Wl,-rpath",
+	"-Wl,-R",
+	"-Wl,--just-symbols",
+	"-Wl,-undefined",
+}
+
+func checkCompilerFlags(name string, list []string) error {
+	return checkFlags(name, list, validCompilerFlags, validCompilerFlagsWithNextArg)
+}
+
+func checkLinkerFlags(name string, list []string) error {
+	return checkFlags(name, list, validLinkerFlags, validLinkerFlagsWithNextArg)
+}
+
+func checkFlags(name string, list []string, valid []*regexp.Regexp, validNext []string) error {
+	// Let users override rules with $CGO_CFLAGS_ALLOW, $CGO_CFLAGS_DISALLOW, etc.
+	var (
+		allow    *regexp.Regexp
+		disallow *regexp.Regexp
+	)
+	if env := os.Getenv("CGO_" + name + "_ALLOW"); env != "" {
+		r, err := regexp.Compile(env)
+		if err != nil {
+			return fmt.Errorf("parsing $CGO_%s_ALLOW: %v", name, err)
+		}
+		allow = r
+	}
+	if env := os.Getenv("CGO_" + name + "_DISALLOW"); env != "" {
+		r, err := regexp.Compile(env)
+		if err != nil {
+			return fmt.Errorf("parsing $CGO_%s_DISALLOW: %v", name, err)
+		}
+		disallow = r
+	}
+
+Args:
+	for i := 0; i < len(list); i++ {
+		arg := list[i]
+		if disallow != nil && disallow.FindString(arg) == arg {
+			goto Bad
+		}
+		if allow != nil && allow.FindString(arg) == arg {
+			continue Args
+		}
+		for _, re := range valid {
+			if re.FindString(arg) == arg { // must be complete match
+				continue Args
+			}
+		}
+		for _, x := range validNext {
+			if arg == x {
+				if i+1 < len(list) && safeArg(list[i+1]) {
+					i++
+					continue Args
+				}
+
+				// Permit -Wl,-framework -Wl,name.
+				if i+1 < len(list) &&
+					strings.HasPrefix(arg, "-Wl,") &&
+					strings.HasPrefix(list[i+1], "-Wl,") &&
+					safeArg(list[i+1][4:]) &&
+					!strings.Contains(list[i+1][4:], ",") {
+					i++
+					continue Args
+				}
+
+				if i+1 < len(list) {
+					return fmt.Errorf("invalid flag: %s %s (see https://golang.org/s/invalidflag)", arg, list[i+1])
+				}
+				return fmt.Errorf("invalid flag: %s without argument (see https://golang.org/s/invalidflag)", arg)
+			}
+		}
+	Bad:
+		return fmt.Errorf("invalid flag: %s", arg)
+	}
+	return nil
+}
+
+func safeArg(name string) bool {
+	if name == "" {
+		return false
+	}
+	c := name[0]
+	return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || c == '.' || c == '_' || c == '/' || c >= utf8.RuneSelf
+}

cgo/security_test.go

@@ -0,0 +1,260 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file has been copied from the Go 1.13 release tree.
+
+package cgo
+
+import (
+	"os"
+	"testing"
+)
+
+var goodCompilerFlags = [][]string{
+	{"-DFOO"},
+	{"-Dfoo=bar"},
+	{"-F/Qt"},
+	{"-I/"},
+	{"-I/etc/passwd"},
+	{"-I."},
+	{"-O"},
+	{"-O2"},
+	{"-Osmall"},
+	{"-W"},
+	{"-Wall"},
+	{"-fobjc-arc"},
+	{"-fno-objc-arc"},
+	{"-fomit-frame-pointer"},
+	{"-fno-omit-frame-pointer"},
+	{"-fpic"},
+	{"-fno-pic"},
+	{"-fPIC"},
+	{"-fno-PIC"},
+	{"-fpie"},
+	{"-fno-pie"},
+	{"-fPIE"},
+	{"-fno-PIE"},
+	{"-fsplit-stack"},
+	{"-fno-split-stack"},
+	{"-fstack-xxx"},
+	{"-fno-stack-xxx"},
+	{"-fsanitize=hands"},
+	{"-g"},
+	{"-ggdb"},
+	{"-march=souza"},
+	{"-mcpu=123"},
+	{"-mfpu=123"},
+	{"-mtune=happybirthday"},
+	{"-mstack-overflow"},
+	{"-mno-stack-overflow"},
+	{"-mmacosx-version"},
+	{"-mnop-fun-dllimport"},
+	{"-pthread"},
+	{"-std=c99"},
+	{"-xc"},
+	{"-D", "FOO"},
+	{"-D", "foo=bar"},
+	{"-I", "."},
+	{"-I", "/etc/passwd"},
+	{"-I", "世界"},
+	{"-framework", "Chocolate"},
+	{"-x", "c"},
+	{"-v"},
+}
+
+var badCompilerFlags = [][]string{
+	{"-D@X"},
+	{"-D-X"},
+	{"-F@dir"},
+	{"-F-dir"},
+	{"-I@dir"},
+	{"-I-dir"},
+	{"-O@1"},
+	{"-Wa,-foo"},
+	{"-W@foo"},
+	{"-g@gdb"},
+	{"-g-gdb"},
+	{"-march=@dawn"},
+	{"-march=-dawn"},
+	{"-std=@c99"},
+	{"-std=-c99"},
+	{"-x@c"},
+	{"-x-c"},
+	{"-D", "@foo"},
+	{"-D", "-foo"},
+	{"-I", "@foo"},
+	{"-I", "-foo"},
+	{"-framework", "-Caffeine"},
+	{"-framework", "@Home"},
+	{"-x", "--c"},
+	{"-x", "@obj"},
+}
+
+func TestCheckCompilerFlags(t *testing.T) {
+	for _, f := range goodCompilerFlags {
+		if err := checkCompilerFlags("test", f); err != nil {
+			t.Errorf("unexpected error for %q: %v", f, err)
+		}
+	}
+	for _, f := range badCompilerFlags {
+		if err := checkCompilerFlags("test", f); err == nil {
+			t.Errorf("missing error for %q", f)
+		}
+	}
+}
+
+var goodLinkerFlags = [][]string{
+	{"-Fbar"},
+	{"-lbar"},
+	{"-Lbar"},
+	{"-fpic"},
+	{"-fno-pic"},
+	{"-fPIC"},
+	{"-fno-PIC"},
+	{"-fpie"},
+	{"-fno-pie"},
+	{"-fPIE"},
+	{"-fno-PIE"},
+	{"-fsanitize=hands"},
+	{"-g"},
+	{"-ggdb"},
+	{"-march=souza"},
+	{"-mcpu=123"},
+	{"-mfpu=123"},
+	{"-mtune=happybirthday"},
+	{"-pic"},
+	{"-pthread"},
+	{"-Wl,-rpath,foo"},
+	{"-Wl,-rpath,$ORIGIN/foo"},
+	{"-Wl,-R", "/foo"},
+	{"-Wl,-R", "foo"},
+	{"-Wl,-R,foo"},
+	{"-Wl,--just-symbols=foo"},
+	{"-Wl,--just-symbols,foo"},
+	{"-Wl,--warn-error"},
+	{"-Wl,--no-warn-error"},
+	{"foo.so"},
+	{"_世界.dll"},
+	{"./x.o"},
+	{"libcgosotest.dylib"},
+	{"-F", "framework"},
+	{"-l", "."},
+	{"-l", "/etc/passwd"},
+	{"-l", "世界"},
+	{"-L", "framework"},
+	{"-framework", "Chocolate"},
+	{"-v"},
+	{"-Wl,-framework", "-Wl,Chocolate"},
+	{"-Wl,-framework,Chocolate"},
+	{"-Wl,-unresolved-symbols=ignore-all"},
+}
+
+var badLinkerFlags = [][]string{
+	{"-DFOO"},
+	{"-Dfoo=bar"},
+	{"-W"},
+	{"-Wall"},
+	{"-fobjc-arc"},
+	{"-fno-objc-arc"},
+	{"-fomit-frame-pointer"},
+	{"-fno-omit-frame-pointer"},
+	{"-fsplit-stack"},
+	{"-fno-split-stack"},
+	{"-fstack-xxx"},
+	{"-fno-stack-xxx"},
+	{"-mstack-overflow"},
+	{"-mno-stack-overflow"},
+	{"-mnop-fun-dllimport"},
+	{"-std=c99"},
+	{"-xc"},
+	{"-D", "FOO"},
+	{"-D", "foo=bar"},
+	{"-I", "FOO"},
+	{"-L", "@foo"},
+	{"-L", "-foo"},
+	{"-x", "c"},
+	{"-D@X"},
+	{"-D-X"},
+	{"-I@dir"},
+	{"-I-dir"},
+	{"-O@1"},
+	{"-Wa,-foo"},
+	{"-W@foo"},
+	{"-g@gdb"},
+	{"-g-gdb"},
+	{"-march=@dawn"},
+	{"-march=-dawn"},
+	{"-std=@c99"},
+	{"-std=-c99"},
+	{"-x@c"},
+	{"-x-c"},
+	{"-D", "@foo"},
+	{"-D", "-foo"},
+	{"-I", "@foo"},
+	{"-I", "-foo"},
+	{"-l", "@foo"},
+	{"-l", "-foo"},
+	{"-framework", "-Caffeine"},
+	{"-framework", "@Home"},
+	{"-Wl,-framework,-Caffeine"},
+	{"-Wl,-framework", "-Wl,@Home"},
+	{"-Wl,-framework", "@Home"},
+	{"-Wl,-framework,Chocolate,@Home"},
+	{"-x", "--c"},
+	{"-x", "@obj"},
+	{"-Wl,-rpath,@foo"},
+	{"-Wl,-R,foo,bar"},
+	{"-Wl,-R,@foo"},
+	{"-Wl,--just-symbols,@foo"},
+	{"../x.o"},
+}
+
+func TestCheckLinkerFlags(t *testing.T) {
+	for _, f := range goodLinkerFlags {
+		if err := checkLinkerFlags("test", f); err != nil {
+			t.Errorf("unexpected error for %q: %v", f, err)
+		}
+	}
+	for _, f := range badLinkerFlags {
+		if err := checkLinkerFlags("test", f); err == nil {
+			t.Errorf("missing error for %q", f)
+		}
+	}
+}
+
+func TestCheckFlagAllowDisallow(t *testing.T) {
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err == nil {
+		t.Fatalf("missing error for -disallow")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-disallo")
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err == nil {
+		t.Fatalf("missing error for -disallow with CGO_TEST_ALLOW=-disallo")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-disallow")
+	if err := checkCompilerFlags("TEST", []string{"-disallow"}); err != nil {
+		t.Fatalf("unexpected error for -disallow with CGO_TEST_ALLOW=-disallow: %v", err)
+	}
+	os.Unsetenv("CGO_TEST_ALLOW")
+
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err != nil {
+		t.Fatalf("unexpected error for -Wall: %v", err)
+	}
+	os.Setenv("CGO_TEST_DISALLOW", "-Wall")
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err == nil {
+		t.Fatalf("missing error for -Wall with CGO_TEST_DISALLOW=-Wall")
+	}
+	os.Setenv("CGO_TEST_ALLOW", "-Wall") // disallow wins
+	if err := checkCompilerFlags("TEST", []string{"-Wall"}); err == nil {
+		t.Fatalf("missing error for -Wall with CGO_TEST_DISALLOW=-Wall and CGO_TEST_ALLOW=-Wall")
+	}
+
+	os.Setenv("CGO_TEST_ALLOW", "-fplugin.*")
+	os.Setenv("CGO_TEST_DISALLOW", "-fplugin=lint.so")
+	if err := checkCompilerFlags("TEST", []string{"-fplugin=faster.so"}); err != nil {
+		t.Fatalf("unexpected error for -fplugin=faster.so: %v", err)
+	}
+	if err := checkCompilerFlags("TEST", []string{"-fplugin=lint.so"}); err == nil {
+		t.Fatalf("missing error for -fplugin=lint.so: %v", err)
+	}
+}

cgo/sync.go

@@ -0,0 +1,46 @@
+package cgo
+
+import (
+	"sync"
+	"unsafe"
+)
+
+// #include <stdlib.h>
+import "C"
+
+// refMap is a convenient way to store opaque references that can be passed to
+// C. It is useful if an API uses function pointers and you cannot pass a Go
+// pointer but only a C pointer.
+type refMap struct {
+	refs map[unsafe.Pointer]interface{}
+	lock sync.Mutex
+}
+
+// Put stores a value in the map. It can later be retrieved using Get. It must
+// be removed using Remove to avoid memory leaks.
+func (m *refMap) Put(v interface{}) unsafe.Pointer {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	if m.refs == nil {
+		m.refs = make(map[unsafe.Pointer]interface{}, 1)
+	}
+	ref := C.malloc(1)
+	m.refs[ref] = v
+	return ref
+}
+
+// Get returns a stored value previously inserted with Put. Use the same
+// reference as you got from Put.
+func (m *refMap) Get(ref unsafe.Pointer) interface{} {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	return m.refs[ref]
+}
+
+// Remove deletes a single reference from the map.
+func (m *refMap) Remove(ref unsafe.Pointer) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	delete(m.refs, ref)
+	C.free(ref)
+}

cgo/testdata/basic.go

@@ -0,0 +1,3 @@
+package main
+
+import "C"

cgo/testdata/basic.out.go

@@ -0,0 +1,26 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/const.go

@@ -0,0 +1,12 @@
+package main
+
+/*
+#define foo 3
+#define bar foo
+*/
+import "C"
+
+const (
+	Foo = C.foo
+	Bar = C.bar
+)

cgo/testdata/const.out.go

@@ -0,0 +1,29 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.bar = C.foo
+const C.foo = 3
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/errors.go

@@ -0,0 +1,33 @@
+package main
+
+/*
+#warning some warning
+
+typedef struct {
+	int x;
+	int y;
+} point_t;
+
+typedef someType noType; // undefined type
+
+#define SOME_CONST_1 5) // invalid const syntax
+#define SOME_CONST_2 6) // const not used (so no error)
+#define SOME_CONST_3 1234 // const too large for byte
+*/
+import "C"
+
+// Make sure that errors for the following lines won't change with future
+// additions to the CGo preamble.
+//line errors.go:100
+var (
+	// constant too large
+	_ C.uint8_t = 2 << 10
+
+	// z member does not exist
+	_ C.point_t = C.point_t{z: 3}
+
+	// constant has syntax error
+	_ = C.SOME_CONST_1
+
+	_ byte = C.SOME_CONST_3
+)

cgo/testdata/errors.out.go

@@ -0,0 +1,43 @@
+// CGo errors:
+//     testdata/errors.go:4:2: warning: some warning
+//     testdata/errors.go:11:9: error: unknown type name 'someType'
+//     testdata/errors.go:13:23: unexpected token )
+
+// Type checking errors after CGo processing:
+//     testdata/errors.go:102: 2 << 10 (untyped int constant 2048) overflows uint8
+//     testdata/errors.go:105: unknown field z in struct literal
+//     testdata/errors.go:108: undeclared name: C.SOME_CONST_1
+//     testdata/errors.go:110: C.SOME_CONST_3 (untyped int constant 1234) overflows byte
+
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.SOME_CONST_3 = 1234
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16
+type C.point_t = struct {
+	x C.int
+	y C.int
+}

cgo/testdata/flags.go

@@ -0,0 +1,26 @@
+package main
+
+/*
+// this name doesn't exist
+#cgo  NOFLAGS: -foo
+
+// unknown flag
+#cgo CFLAGS: -fdoes-not-exist -DNOTDEFINED
+
+#cgo CFLAGS: -DFOO
+
+#if defined(FOO)
+#define BAR 3
+#else
+#define BAR 5
+#endif
+
+#if defined(NOTDEFINED)
+#warning flag must not be defined
+#endif
+*/
+import "C"
+
+var (
+	_ = C.BAR
+)

cgo/testdata/flags.out.go

@@ -0,0 +1,32 @@
+// CGo errors:
+//     testdata/flags.go:5:7: invalid #cgo line: NOFLAGS
+//     testdata/flags.go:8:13: invalid flag: -fdoes-not-exist
+
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.BAR = 3
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16

cgo/testdata/types.go

@@ -0,0 +1,165 @@
+package main
+
+/*
+// Simple typedef.
+typedef int myint;
+
+// Structs, with or without name.
+typedef struct {
+	int x;
+	int y;
+} point2d_t;
+typedef struct point3d {
+	int x;
+	int y;
+	int z;
+} point3d_t;
+
+// Structs with reserved field names.
+struct type1 {
+	// All these fields should be renamed.
+	int type;
+	int _type;
+	int __type;
+};
+struct type2 {
+	// This field should not be renamed.
+	int _type;
+};
+
+// Unions.
+typedef union {
+	// Union should be treated as a struct.
+	int i;
+} union1_t;
+typedef union {
+	// Union must contain a single field and have special getters/setters.
+	int    i;
+	double d;
+	short  s;
+} union3_t;
+typedef union union2d {
+	int i;
+	double d[2];
+} union2d_t;
+typedef union {
+	unsigned char arr[10];
+} unionarray_t;
+
+// Nested structs and unions.
+typedef struct {
+	point2d_t begin;
+	point2d_t end;
+	int       tag;
+	union {
+		point2d_t area;
+		point3d_t solid;
+	} coord;
+} struct_nested_t;
+typedef union {
+	point3d_t    point;
+	unionarray_t array;
+	union3_t     thing;
+} union_nested_t;
+
+// Enums. These define constant numbers. All these constants must be given the
+// correct number.
+typedef enum option {
+	optionA,
+	optionB,
+	optionC = -5,
+	optionD,
+	optionE = 10,
+	optionF,
+	optionG,
+} option_t;
+enum unused {
+	unused1 = 5,
+};
+
+// Anonymous enum.
+typedef enum {
+	option2A = 20,
+} option2_t;
+
+// Various types that are usually translated directly to Go types, but storing
+// them in a struct reveals them.
+typedef struct {
+	float  f;
+	double d;
+	int    *ptr;
+} types_t;
+
+// Arrays.
+typedef int myIntArray[10];
+
+// Bitfields.
+typedef struct {
+	unsigned char start;
+	unsigned char a : 5;
+	unsigned char b : 1;
+	unsigned char c : 2;
+	unsigned char :0; // new field
+	unsigned char d : 6;
+	unsigned char e : 3;
+	// Note that C++ allows bitfields bigger than the underlying type.
+} bitfield_t;
+*/
+import "C"
+
+var (
+	// Simple typedefs.
+	_ C.myint
+
+	// Structs.
+	_ C.point2d_t
+	_ C.point3d_t
+	_ C.struct_point3d
+
+	// Structs with reserved field names.
+	_ C.struct_type1
+	_ C.struct_type2
+
+	// Unions.
+	_ C.union1_t
+	_ C.union3_t
+	_ C.union2d_t
+	_ C.unionarray_t
+
+	// Nested structs and unions.
+	_ C.struct_nested_t
+	_ C.union_nested_t
+
+	// Enums (anonymous and named).
+	_ C.option_t
+	_ C.enum_option
+	_ C.option2_t
+
+	// Various types.
+	_ C.types_t
+
+	// Arrays.
+	_ C.myIntArray
+)
+
+// Test bitfield accesses.
+func accessBitfields() {
+	var x C.bitfield_t
+	x.start = 3
+	x.set_bitfield_a(4)
+	x.set_bitfield_b(1)
+	x.set_bitfield_c(2)
+	x.d = 10
+	x.e = 5
+	var _ C.uchar = x.bitfield_a()
+}
+
+// Test union accesses.
+func accessUnion() {
+	var union1 C.union1_t
+	union1.i = 5
+
+	var union2d C.union2d_t
+	var _ *C.int = union2d.unionfield_i()
+	var _ *[2]float64 = union2d.unionfield_d()
+}

cgo/testdata/types.out.go

@@ -0,0 +1,119 @@
+package main
+
+import "unsafe"
+
+var _ unsafe.Pointer
+
+const C.option2A = 20
+const C.optionA = 0
+const C.optionB = 1
+const C.optionC = -5
+const C.optionD = -4
+const C.optionE = 10
+const C.optionF = 11
+const C.optionG = 12
+const C.unused1 = 5
+
+type C.int16_t = int16
+type C.int32_t = int32
+type C.int64_t = int64
+type C.int8_t = int8
+type C.uint16_t = uint16
+type C.uint32_t = uint32
+type C.uint64_t = uint64
+type C.uint8_t = uint8
+type C.uintptr_t = uintptr
+type C.char uint8
+type C.int int32
+type C.long int32
+type C.longlong int64
+type C.schar int8
+type C.short int16
+type C.uchar uint8
+type C.uint uint32
+type C.ulong uint32
+type C.ulonglong uint64
+type C.ushort uint16
+type C.bitfield_t = C.struct_4
+type C.myIntArray = [10]C.int
+type C.myint = C.int
+type C.option2_t = C.uint
+type C.option_t = C.enum_option
+type C.point2d_t = struct {
+	x C.int
+	y C.int
+}
+type C.point3d_t = C.struct_point3d
+type C.struct_nested_t = struct {
+	begin C.point2d_t
+	end   C.point2d_t
+	tag   C.int
+
+	coord C.union_2
+}
+type C.types_t = struct {
+	f   float32
+	d   float64
+	ptr *C.int
+}
+type C.union1_t = struct{ i C.int }
+type C.union2d_t = C.union_union2d
+type C.union3_t = C.union_1
+type C.union_nested_t = C.union_3
+type C.unionarray_t = struct{ arr [10]C.uchar }
+
+func (s *C.struct_4) bitfield_a() C.uchar          { return s.__bitfield_1 & 0x1f }
+func (s *C.struct_4) set_bitfield_a(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x1f | value&0x1f<<0 }
+func (s *C.struct_4) bitfield_b() C.uchar {
+	return s.__bitfield_1 >> 5 & 0x1
+}
+func (s *C.struct_4) set_bitfield_b(value C.uchar) { s.__bitfield_1 = s.__bitfield_1&^0x20 | value&0x1<<5 }
+func (s *C.struct_4) bitfield_c() C.uchar {
+	return s.__bitfield_1 >> 6
+}
+func (s *C.struct_4) set_bitfield_c(value C.uchar,
+
+) { s.__bitfield_1 = s.__bitfield_1&0x3f | value<<6 }
+
+type C.struct_4 struct {
+	start        C.uchar
+	__bitfield_1 C.uchar
+
+	d C.uchar
+	e C.uchar
+}
+type C.struct_point3d struct {
+	x C.int
+	y C.int
+	z C.int
+}
+type C.struct_type1 struct {
+	_type   C.int
+	__type  C.int
+	___type C.int
+}
+type C.struct_type2 struct{ _type C.int }
+
+func (union *C.union_1) unionfield_i() *C.int   { return (*C.int)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_1) unionfield_d() *float64 { return (*float64)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_1) unionfield_s() *C.short { return (*C.short)(unsafe.Pointer(&union.$union)) }
+
+type C.union_1 struct{ $union uint64 }
+
+func (union *C.union_2) unionfield_area() *C.point2d_t  { return (*C.point2d_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_2) unionfield_solid() *C.point3d_t { return (*C.point3d_t)(unsafe.Pointer(&union.$union)) }
+
+type C.union_2 struct{ $union [3]uint32 }
+
+func (union *C.union_3) unionfield_point() *C.point3d_t    { return (*C.point3d_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_3) unionfield_array() *C.unionarray_t { return (*C.unionarray_t)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_3) unionfield_thing() *C.union3_t     { return (*C.union3_t)(unsafe.Pointer(&union.$union)) }
+
+type C.union_3 struct{ $union [2]uint64 }
+
+func (union *C.union_union2d) unionfield_i() *C.int      { return (*C.int)(unsafe.Pointer(&union.$union)) }
+func (union *C.union_union2d) unionfield_d() *[2]float64 { return (*[2]float64)(unsafe.Pointer(&union.$union)) }
+
+type C.union_union2d struct{ $union [2]uint64 }
+type C.enum_option C.int
+type C.enum_unused C.uint

compileopts/config.go

@@ -0,0 +1,227 @@
+// Package compileopts contains the configuration for a single to-be-built
+// binary.
+package compileopts
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+// Config keeps all configuration affecting the build in a single struct.
+type Config struct {
+	Options        *Options
+	Target         *TargetSpec
+	GoMinorVersion int
+	ClangHeaders   string // Clang built-in header include path
+	TestConfig     TestConfig
+}
+
+// Triple returns the LLVM target triple, like armv6m-none-eabi.
+func (c *Config) Triple() string {
+	return c.Target.Triple
+}
+
+// CPU returns the LLVM CPU name, like atmega328p or arm7tdmi. It may return an
+// empty string if the CPU name is not known.
+func (c *Config) CPU() string {
+	return c.Target.CPU
+}
+
+// Features returns a list of features this CPU supports. For example, for a
+// RISC-V processor, that could be ["+a", "+c", "+m"]. For many targets, an
+// empty list will be returned.
+func (c *Config) Features() []string {
+	return c.Target.Features
+}
+
+// GOOS returns the GOOS of the target. This might not always be the actual OS:
+// for example, bare-metal targets will usually pretend to be linux to get the
+// standard library to compile.
+func (c *Config) GOOS() string {
+	return c.Target.GOOS
+}
+
+// GOARCH returns the GOARCH of the target. This might not always be the actual
+// archtecture: for example, the AVR target is not supported by the Go standard
+// library so such targets will usually pretend to be linux/arm.
+func (c *Config) GOARCH() string {
+	return c.Target.GOARCH
+}
+
+// BuildTags returns the complete list of build tags used during this build.
+func (c *Config) BuildTags() []string {
+	tags := append(c.Target.BuildTags, []string{"tinygo", "gc." + c.GC(), "scheduler." + c.Scheduler()}...)
+	for i := 1; i <= c.GoMinorVersion; i++ {
+		tags = append(tags, fmt.Sprintf("go1.%d", i))
+	}
+	if extraTags := strings.Fields(c.Options.Tags); len(extraTags) != 0 {
+		tags = append(tags, extraTags...)
+	}
+	return tags
+}
+
+// CgoEnabled returns true if (and only if) CGo is enabled. It is true by
+// default and false if CGO_ENABLED is set to "0".
+func (c *Config) CgoEnabled() bool {
+	return goenv.Get("CGO_ENABLED") == "1"
+}
+
+// GC returns the garbage collection strategy in use on this platform. Valid
+// values are "none", "leaking", and "conservative".
+func (c *Config) GC() string {
+	if c.Options.GC != "" {
+		return c.Options.GC
+	}
+	if c.Target.GC != "" {
+		return c.Target.GC
+	}
+	return "conservative"
+}
+
+// NeedsStackObjects returns true if the compiler should insert stack objects
+// that can be traced by the garbage collector.
+func (c *Config) NeedsStackObjects() bool {
+	if c.GC() != "conservative" {
+		return false
+	}
+	for _, tag := range c.BuildTags() {
+		if tag == "baremetal" {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Scheduler returns the scheduler implementation. Valid values are "coroutines"
+// and "tasks".
+func (c *Config) Scheduler() string {
+	if c.Options.Scheduler != "" {
+		return c.Options.Scheduler
+	}
+	if c.Target.Scheduler != "" {
+		return c.Target.Scheduler
+	}
+	// Fall back to coroutines, which are supported everywhere.
+	return "coroutines"
+}
+
+// PanicStrategy returns the panic strategy selected for this target. Valid
+// values are "print" (print the panic value, then exit) or "trap" (issue a trap
+// instruction).
+func (c *Config) PanicStrategy() string {
+	return c.Options.PanicStrategy
+}
+
+// CFlags returns the flags to pass to the C compiler. This is necessary for CGo
+// preprocessing.
+func (c *Config) CFlags() []string {
+	cflags := append([]string{}, c.Options.CFlags...)
+	for _, flag := range c.Target.CFlags {
+		cflags = append(cflags, strings.Replace(flag, "{root}", goenv.Get("TINYGOROOT"), -1))
+	}
+	return cflags
+}
+
+// LDFlags returns the flags to pass to the linker. A few more flags are needed
+// (like the one for the compiler runtime), but this represents the majority of
+// the flags.
+func (c *Config) LDFlags() []string {
+	root := goenv.Get("TINYGOROOT")
+	// Merge and adjust LDFlags.
+	ldflags := append([]string{}, c.Options.LDFlags...)
+	for _, flag := range c.Target.LDFlags {
+		ldflags = append(ldflags, strings.Replace(flag, "{root}", root, -1))
+	}
+	ldflags = append(ldflags, "-L", root)
+	if c.Target.GOARCH == "wasm" {
+		// Round heap size to next multiple of 65536 (the WebAssembly page
+		// size).
+		heapSize := (c.Options.HeapSize + (65536 - 1)) &^ (65536 - 1)
+		ldflags = append(ldflags, "--initial-memory="+strconv.FormatInt(heapSize, 10))
+	}
+	if c.Target.LinkerScript != "" {
+		ldflags = append(ldflags, "-T", c.Target.LinkerScript)
+	}
+	return ldflags
+}
+
+// ExtraFiles returns the list of extra files to be built and linked with the
+// executable. This can include extra C and assembly files.
+func (c *Config) ExtraFiles() []string {
+	return c.Target.ExtraFiles
+}
+
+// DumpSSA returns whether to dump Go SSA while compiling (-dumpssa flag). Only
+// enable this for debugging.
+func (c *Config) DumpSSA() bool {
+	return c.Options.DumpSSA
+}
+
+// VerifyIR returns whether to run extra checks on the IR. This is normally
+// disabled but enabled during testing.
+func (c *Config) VerifyIR() bool {
+	return c.Options.VerifyIR
+}
+
+// Debug returns whether to add debug symbols to the IR, for debugging with GDB
+// and similar.
+func (c *Config) Debug() bool {
+	return c.Options.Debug
+}
+
+// Programmer returns the flash method and OpenOCD interface name given a
+// particular configuration. It may either be all configured in the target JSON
+// file or be modified using the -programmmer command-line option.
+func (c *Config) Programmer() (method, openocdInterface string) {
+	switch c.Options.Programmer {
+	case "":
+		// No configuration supplied.
+		return c.Target.FlashMethod, c.Target.OpenOCDInterface
+	case "openocd", "msd", "command":
+		// The -programmer flag only specifies the flash method.
+		return c.Options.Programmer, c.Target.OpenOCDInterface
+	default:
+		// The -programmer flag specifies something else, assume it specifies
+		// the OpenOCD interface name.
+		return "openocd", c.Options.Programmer
+	}
+}
+
+// OpenOCDConfiguration returns a list of command line arguments to OpenOCD.
+// This list of command-line arguments is based on the various OpenOCD-related
+// flags in the target specification.
+func (c *Config) OpenOCDConfiguration() (args []string, err error) {
+	_, openocdInterface := c.Programmer()
+	if openocdInterface == "" {
+		return nil, errors.New("OpenOCD programmer not set")
+	}
+	if !regexp.MustCompile("^[\\p{L}0-9_-]+$").MatchString(openocdInterface) {
+		return nil, fmt.Errorf("OpenOCD programmer has an invalid name: %#v", openocdInterface)
+	}
+	if c.Target.OpenOCDTarget == "" {
+		return nil, errors.New("OpenOCD chip not set")
+	}
+	if !regexp.MustCompile("^[\\p{L}0-9_-]+$").MatchString(c.Target.OpenOCDTarget) {
+		return nil, fmt.Errorf("OpenOCD target has an invalid name: %#v", c.Target.OpenOCDTarget)
+	}
+	if c.Target.OpenOCDTransport != "" && c.Target.OpenOCDTransport != "swd" {
+		return nil, fmt.Errorf("unknown OpenOCD transport: %#v", c.Target.OpenOCDTransport)
+	}
+	args = []string{"-f", "interface/" + openocdInterface + ".cfg"}
+	if c.Target.OpenOCDTransport != "" {
+		args = append(args, "-c", "transport select "+c.Target.OpenOCDTransport)
+	}
+	args = append(args, "-f", "target/"+c.Target.OpenOCDTarget+".cfg")
+	return args, nil
+}
+
+type TestConfig struct {
+	CompileTestBinary bool
+	// TODO: Filter the test functions to run, include verbose flag, etc
+}

compileopts/options.go

@@ -0,0 +1,23 @@
+package compileopts
+
+// Options contains extra options to give to the compiler. These options are
+// usually passed from the command line.
+type Options struct {
+	Target        string
+	Opt           string
+	GC            string
+	PanicStrategy string
+	Scheduler     string
+	PrintIR       bool
+	DumpSSA       bool
+	VerifyIR      bool
+	Debug         bool
+	PrintSizes    string
+	CFlags        []string
+	LDFlags       []string
+	Tags          string
+	WasmAbi       string
+	HeapSize      int64
+	TestConfig    TestConfig
+	Programmer    string
+}

compileopts/target.go

@@ -1,15 +1,17 @@
-package main
+package compileopts
+
+// This file loads a target specification from a JSON file.
 
 import (
 	"encoding/json"
 	"errors"
-	"fmt"
 	"io"
 	"os"
-	"os/user"
 	"path/filepath"
 	"runtime"
 	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
 )
 
 // Target specification for a given target. Used for bare metal targets.
@@ -18,25 +20,34 @@ import (
 // https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/spec/struct.TargetOptions.html
 // https://github.com/shepmaster/rust-arduino-blink-led-no-core-with-cargo/blob/master/blink/arduino.json
 type TargetSpec struct {
-	Inherits   []string `json:"inherits"`
-	Triple     string   `json:"llvm-target"`
-	CPU        string   `json:"cpu"`
-	GOOS       string   `json:"goos"`
-	GOARCH     string   `json:"goarch"`
-	BuildTags  []string `json:"build-tags"`
-	GC         string   `json:"gc"`
-	Compiler   string   `json:"compiler"`
-	Linker     string   `json:"linker"`
-	RTLib      string   `json:"rtlib"` // compiler runtime library (libgcc, compiler-rt)
-	CFlags     []string `json:"cflags"`
-	LDFlags    []string `json:"ldflags"`
-	ExtraFiles []string `json:"extra-files"`
-	Objcopy    string   `json:"objcopy"`
-	Emulator   []string `json:"emulator"`
-	Flasher    string   `json:"flash"`
-	OCDDaemon  []string `json:"ocd-daemon"`
-	GDB        string   `json:"gdb"`
-	GDBCmds    []string `json:"gdb-initial-cmds"`
+	Inherits         []string `json:"inherits"`
+	Triple           string   `json:"llvm-target"`
+	CPU              string   `json:"cpu"`
+	Features         []string `json:"features"`
+	GOOS             string   `json:"goos"`
+	GOARCH           string   `json:"goarch"`
+	BuildTags        []string `json:"build-tags"`
+	GC               string   `json:"gc"`
+	Scheduler        string   `json:"scheduler"`
+	Compiler         string   `json:"compiler"`
+	Linker           string   `json:"linker"`
+	RTLib            string   `json:"rtlib"` // compiler runtime library (libgcc, compiler-rt)
+	CFlags           []string `json:"cflags"`
+	LDFlags          []string `json:"ldflags"`
+	LinkerScript     string   `json:"linkerscript"`
+	ExtraFiles       []string `json:"extra-files"`
+	Emulator         []string `json:"emulator"`
+	FlashCommand     string   `json:"flash-command"`
+	GDB              string   `json:"gdb"`
+	PortReset        string   `json:"flash-1200-bps-reset"`
+	FlashMethod      string   `json:"flash-method"`
+	FlashVolume      string   `json:"msd-volume-name"`
+	FlashFilename    string   `json:"msd-firmware-name"`
+	UF2FamilyID      string   `json:"uf2-family-id"`
+	OpenOCDInterface string   `json:"openocd-interface"`
+	OpenOCDTarget    string   `json:"openocd-target"`
+	OpenOCDTransport string   `json:"openocd-transport"`
+	JLinkDevice      string   `json:"jlink-device"`
 }
 
 // copyProperties copies all properties that are set in spec2 into itself.
@@ -50,6 +61,7 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	if spec2.CPU != "" {
 		spec.CPU = spec2.CPU
 	}
+	spec.Features = append(spec.Features, spec2.Features...)
 	if spec2.GOOS != "" {
 		spec.GOOS = spec2.GOOS
 	}
@@ -60,6 +72,9 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	if spec2.GC != "" {
 		spec.GC = spec2.GC
 	}
+	if spec2.Scheduler != "" {
+		spec.Scheduler = spec2.Scheduler
+	}
 	if spec2.Compiler != "" {
 		spec.Compiler = spec2.Compiler
 	}
@@ -71,24 +86,45 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	}
 	spec.CFlags = append(spec.CFlags, spec2.CFlags...)
 	spec.LDFlags = append(spec.LDFlags, spec2.LDFlags...)
-	spec.ExtraFiles = append(spec.ExtraFiles, spec2.ExtraFiles...)
-	if spec2.Objcopy != "" {
-		spec.Objcopy = spec2.Objcopy
+	if spec2.LinkerScript != "" {
+		spec.LinkerScript = spec2.LinkerScript
 	}
+	spec.ExtraFiles = append(spec.ExtraFiles, spec2.ExtraFiles...)
 	if len(spec2.Emulator) != 0 {
 		spec.Emulator = spec2.Emulator
 	}
-	if spec2.Flasher != "" {
-		spec.Flasher = spec2.Flasher
-	}
-	if len(spec2.OCDDaemon) != 0 {
-		spec.OCDDaemon = spec2.OCDDaemon
+	if spec2.FlashCommand != "" {
+		spec.FlashCommand = spec2.FlashCommand
 	}
 	if spec2.GDB != "" {
 		spec.GDB = spec2.GDB
 	}
-	if len(spec2.GDBCmds) != 0 {
-		spec.GDBCmds = spec2.GDBCmds
+	if spec2.PortReset != "" {
+		spec.PortReset = spec2.PortReset
+	}
+	if spec2.FlashMethod != "" {
+		spec.FlashMethod = spec2.FlashMethod
+	}
+	if spec2.FlashVolume != "" {
+		spec.FlashVolume = spec2.FlashVolume
+	}
+	if spec2.FlashFilename != "" {
+		spec.FlashFilename = spec2.FlashFilename
+	}
+	if spec2.UF2FamilyID != "" {
+		spec.UF2FamilyID = spec2.UF2FamilyID
+	}
+	if spec2.OpenOCDInterface != "" {
+		spec.OpenOCDInterface = spec2.OpenOCDInterface
+	}
+	if spec2.OpenOCDTarget != "" {
+		spec.OpenOCDTarget = spec2.OpenOCDTarget
+	}
+	if spec2.OpenOCDTransport != "" {
+		spec.OpenOCDTransport = spec2.OpenOCDTransport
+	}
+	if spec2.JLinkDevice != "" {
+		spec.JLinkDevice = spec2.JLinkDevice
 	}
 }
 
@@ -103,10 +139,18 @@ func (spec *TargetSpec) load(r io.Reader) error {
 	return nil
 }
 
-// loadFromName loads the given target from the targets/ directory inside the
-// compiler sources.
-func (spec *TargetSpec) loadFromName(name string) error {
-	path := filepath.Join(sourceDir(), "targets", strings.ToLower(name)+".json")
+// loadFromGivenStr loads the TargetSpec from the given string that could be:
+// - targets/ directory inside the compiler sources
+// - a relative or absolute path to custom (project specific) target specification .json file;
+//   the Inherits[] could contain the files from target folder (ex. stm32f4disco)
+//   as well as path to custom files (ex. myAwesomeProject.json)
+func (spec *TargetSpec) loadFromGivenStr(str string) error {
+	path := ""
+	if strings.HasSuffix(str, ".json") {
+		path, _ = filepath.Abs(str)
+	} else {
+		path = filepath.Join(goenv.Get("TINYGOROOT"), "targets", strings.ToLower(str)+".json")
+	}
 	fp, err := os.Open(path)
 	if err != nil {
 		return err
@@ -121,7 +165,7 @@ func (spec *TargetSpec) resolveInherits() error {
 	newSpec := &TargetSpec{}
 	for _, name := range spec.Inherits {
 		subtarget := &TargetSpec{}
-		err := subtarget.loadFromName(name)
+		err := subtarget.loadFromGivenStr(name)
 		if err != nil {
 			return err
 		}
@@ -144,14 +188,8 @@ func LoadTarget(target string) (*TargetSpec, error) {
 	if target == "" {
 		// Configure based on GOOS/GOARCH environment variables (falling back to
 		// runtime.GOOS/runtime.GOARCH), and generate a LLVM target based on it.
-		goos := os.Getenv("GOOS")
-		if goos == "" {
-			goos = runtime.GOOS
-		}
-		goarch := os.Getenv("GOARCH")
-		if goarch == "" {
-			goarch = runtime.GOARCH
-		}
+		goos := goenv.Get("GOOS")
+		goarch := goenv.Get("GOARCH")
 		llvmos := goos
 		llvmarch := map[string]string{
 			"386":   "i386",
@@ -162,13 +200,16 @@ func LoadTarget(target string) (*TargetSpec, error) {
 			llvmarch = goarch
 		}
 		target = llvmarch + "--" + llvmos
+		if goarch == "arm" {
+			target += "-gnueabihf"
+		}
 		return defaultTarget(goos, goarch, target)
 	}
 
 	// See whether there is a target specification for this target (e.g.
 	// Arduino).
 	spec := &TargetSpec{}
-	err := spec.loadFromName(target)
+	err := spec.loadFromGivenStr(target)
 	if err == nil {
 		// Successfully loaded this target from a built-in .json file. Make sure
 		// it includes all parents as specified in the "inherits" key.
@@ -185,19 +226,31 @@ func LoadTarget(target string) (*TargetSpec, error) {
 		// Load target from given triple, ignore GOOS/GOARCH environment
 		// variables.
 		tripleSplit := strings.Split(target, "-")
-		if len(tripleSplit) == 1 {
+		if len(tripleSplit) < 3 {
 			return nil, errors.New("expected a full LLVM target or a custom target in -target flag")
 		}
+		if tripleSplit[0] == "arm" {
+			// LLVM and Clang have a different idea of what "arm" means, so
+			// upgrade to a slightly more modern ARM. In fact, when you pass
+			// --target=arm--linux-gnueabihf to Clang, it will convert that
+			// internally to armv7-unknown-linux-gnueabihf. Changing the
+			// architecture to armv7 will keep things consistent.
+			tripleSplit[0] = "armv7"
+		}
 		goos := tripleSplit[2]
+		if strings.HasPrefix(goos, "darwin") {
+			goos = "darwin"
+		}
 		goarch := map[string]string{ // map from LLVM arch to Go arch
 			"i386":    "386",
 			"x86_64":  "amd64",
 			"aarch64": "arm64",
+			"armv7":   "arm",
 		}[tripleSplit[0]]
 		if goarch == "" {
 			goarch = tripleSplit[0]
 		}
-		return defaultTarget(goos, goarch, target)
+		return defaultTarget(goos, goarch, strings.Join(tripleSplit, "-"))
 	}
 }
 
@@ -205,28 +258,33 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	// No target spec available. Use the default one, useful on most systems
 	// with a regular OS.
 	spec := TargetSpec{
-		Triple:    triple,
-		GOOS:      goos,
-		GOARCH:    goarch,
-		BuildTags: []string{goos, goarch},
-		Compiler:  commands["clang"],
-		Linker:    "cc",
-		LDFlags:   []string{"-no-pie", "-Wl,--gc-sections"}, // WARNING: clang < 5.0 requires -nopie
-		Objcopy:   "objcopy",
-		GDB:       "gdb",
-		GDBCmds:   []string{"run"},
+		Triple:      triple,
+		GOOS:        goos,
+		GOARCH:      goarch,
+		BuildTags:   []string{goos, goarch},
+		Compiler:    "clang",
+		Linker:      "cc",
+		CFlags:      []string{"--target=" + triple},
+		GDB:         "gdb",
+		PortReset:   "false",
+		FlashMethod: "native",
+	}
+	if goos == "darwin" {
+		spec.LDFlags = append(spec.LDFlags, "-Wl,-dead_strip")
+	} else {
+		spec.LDFlags = append(spec.LDFlags, "-no-pie", "-Wl,--gc-sections") // WARNING: clang < 5.0 requires -nopie
 	}
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
 		if goarch == "arm" && goos == "linux" {
-			spec.Linker = "arm-linux-gnueabi-gcc"
-			spec.Objcopy = "arm-linux-gnueabi-objcopy"
-			spec.GDB = "arm-linux-gnueabi-gdb"
-			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabi"}
+			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/arm-linux-gnueabihf")
+			spec.Linker = "arm-linux-gnueabihf-gcc"
+			spec.GDB = "arm-linux-gnueabihf-gdb"
+			spec.Emulator = []string{"qemu-arm", "-L", "/usr/arm-linux-gnueabihf"}
 		}
 		if goarch == "arm64" && goos == "linux" {
+			spec.CFlags = append(spec.CFlags, "--sysroot=/usr/aarch64-linux-gnu")
 			spec.Linker = "aarch64-linux-gnu-gcc"
-			spec.Objcopy = "aarch64-linux-gnu-objcopy"
 			spec.GDB = "aarch64-linux-gnu-gdb"
 			spec.Emulator = []string{"qemu-aarch64", "-L", "/usr/aarch64-linux-gnu"}
 		}
@@ -237,73 +295,3 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	}
 	return &spec, nil
 }
-
-// Return the TINYGOROOT, or exit with an error.
-func sourceDir() string {
-	// Use $TINYGOROOT as root, if available.
-	root := os.Getenv("TINYGOROOT")
-	if root != "" {
-		if !isSourceDir(root) {
-			fmt.Fprintln(os.Stderr, "error: $TINYGOROOT was not set to the correct root")
-			os.Exit(1)
-		}
-		return root
-	}
-
-	// Find root from executable path.
-	path, err := os.Executable()
-	if err != nil {
-		// Very unlikely. Bail out if it happens.
-		panic("could not get executable path: " + err.Error())
-	}
-	root = filepath.Dir(filepath.Dir(path))
-	if isSourceDir(root) {
-		return root
-	}
-
-	// Fallback: use the original directory from where it was built
-	// https://stackoverflow.com/a/32163888/559350
-	_, path, _, _ = runtime.Caller(0)
-	root = filepath.Dir(path)
-	if isSourceDir(root) {
-		return root
-	}
-
-	fmt.Fprintln(os.Stderr, "error: could not autodetect root directory, set the TINYGOROOT environment variable to override")
-	os.Exit(1)
-	panic("unreachable")
-}
-
-// isSourceDir returns true if the directory looks like a TinyGo source directory.
-func isSourceDir(root string) bool {
-	_, err := os.Stat(filepath.Join(root, "src/runtime/internal/sys/zversion.go"))
-	if err != nil {
-		return false
-	}
-	_, err = os.Stat(filepath.Join(root, "src/device/arm/arm.go"))
-	return err == nil
-}
-
-func getGopath() string {
-	gopath := os.Getenv("GOPATH")
-	if gopath != "" {
-		return gopath
-	}
-
-	// fallback
-	home := getHomeDir()
-	return filepath.Join(home, "go")
-}
-
-func getHomeDir() string {
-	u, err := user.Current()
-	if err != nil {
-		panic("cannot get current user: " + err.Error())
-	}
-	if u.HomeDir == "" {
-		// This is very unlikely, so panic here.
-		// Not the nicest solution, however.
-		panic("could not find home directory")
-	}
-	return u.HomeDir
-}

compileopts/target_test.go

@@ -0,0 +1,19 @@
+package compileopts
+
+import "testing"
+
+func TestLoadTarget(t *testing.T) {
+	_, err := LoadTarget("arduino")
+	if err != nil {
+		t.Error("LoadTarget test failed:", err)
+	}
+
+	_, err = LoadTarget("notexist")
+	if err == nil {
+		t.Error("LoadTarget should have failed with non existing target")
+	}
+
+	if err.Error() != "expected a full LLVM target or a custom target in -target flag" {
+		t.Error("LoadTarget failed for wrong reason:", err)
+	}
+}

compiler/asserts.go

@@ -0,0 +1,166 @@
+package compiler
+
+// This file implements functions that do certain safety checks that are
+// required by the Go programming language.
+
+import (
+	"go/types"
+
+	"tinygo.org/x/go-llvm"
+)
+
+// emitLookupBoundsCheck emits a bounds check before doing a lookup into a
+// slice. This is required by the Go language spec: an index out of bounds must
+// cause a panic.
+func (c *Compiler) emitLookupBoundsCheck(frame *Frame, arrayLen, index llvm.Value, indexType types.Type) {
+	if frame.fn.IsNoBounds() {
+		// The //go:nobounds pragma was added to the function to avoid bounds
+		// checking.
+		return
+	}
+
+	if index.Type().IntTypeWidth() < arrayLen.Type().IntTypeWidth() {
+		// Sometimes, the index can be e.g. an uint8 or int8, and we have to
+		// correctly extend that type.
+		if indexType.Underlying().(*types.Basic).Info()&types.IsUnsigned == 0 {
+			index = c.builder.CreateZExt(index, arrayLen.Type(), "")
+		} else {
+			index = c.builder.CreateSExt(index, arrayLen.Type(), "")
+		}
+	} else if index.Type().IntTypeWidth() > arrayLen.Type().IntTypeWidth() {
+		// The index is bigger than the array length type, so extend it.
+		arrayLen = c.builder.CreateZExt(arrayLen, index.Type(), "")
+	}
+
+	faultBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "lookup.outofbounds")
+	nextBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "lookup.next")
+	frame.blockExits[frame.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+
+	// Now do the bounds check: index >= arrayLen
+	outOfBounds := c.builder.CreateICmp(llvm.IntUGE, index, arrayLen, "")
+	c.builder.CreateCondBr(outOfBounds, faultBlock, nextBlock)
+
+	// Fail: this is a nil pointer, exit with a panic.
+	c.builder.SetInsertPointAtEnd(faultBlock)
+	c.createRuntimeCall("lookupPanic", nil, "")
+	c.builder.CreateUnreachable()
+
+	// Ok: this is a valid pointer.
+	c.builder.SetInsertPointAtEnd(nextBlock)
+}
+
+// emitSliceBoundsCheck emits a bounds check before a slicing operation to make
+// sure it is within bounds.
+//
+// This function is both used for slicing a slice (low and high have their
+// normal meaning) and for creating a new slice, where 'capacity' means the
+// biggest possible slice capacity, 'low' means len and 'high' means cap. The
+// logic is the same in both cases.
+func (c *Compiler) emitSliceBoundsCheck(frame *Frame, capacity, low, high, max llvm.Value, lowType, highType, maxType *types.Basic) {
+	if frame.fn.IsNoBounds() {
+		// The //go:nobounds pragma was added to the function to avoid bounds
+		// checking.
+		return
+	}
+
+	// Extend the capacity integer to be at least as wide as low and high.
+	capacityType := capacity.Type()
+	if low.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = low.Type()
+	}
+	if high.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = high.Type()
+	}
+	if max.Type().IntTypeWidth() > capacityType.IntTypeWidth() {
+		capacityType = max.Type()
+	}
+	if capacityType != capacity.Type() {
+		capacity = c.builder.CreateZExt(capacity, capacityType, "")
+	}
+
+	// Extend low and high to be the same size as capacity.
+	if low.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if lowType.Info()&types.IsUnsigned != 0 {
+			low = c.builder.CreateZExt(low, capacityType, "")
+		} else {
+			low = c.builder.CreateSExt(low, capacityType, "")
+		}
+	}
+	if high.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if highType.Info()&types.IsUnsigned != 0 {
+			high = c.builder.CreateZExt(high, capacityType, "")
+		} else {
+			high = c.builder.CreateSExt(high, capacityType, "")
+		}
+	}
+	if max.Type().IntTypeWidth() < capacityType.IntTypeWidth() {
+		if maxType.Info()&types.IsUnsigned != 0 {
+			max = c.builder.CreateZExt(max, capacityType, "")
+		} else {
+			max = c.builder.CreateSExt(max, capacityType, "")
+		}
+	}
+
+	faultBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "slice.outofbounds")
+	nextBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "slice.next")
+	frame.blockExits[frame.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+
+	// Now do the bounds check: low > high || high > capacity
+	outOfBounds1 := c.builder.CreateICmp(llvm.IntUGT, low, high, "slice.lowhigh")
+	outOfBounds2 := c.builder.CreateICmp(llvm.IntUGT, high, max, "slice.highmax")
+	outOfBounds3 := c.builder.CreateICmp(llvm.IntUGT, max, capacity, "slice.maxcap")
+	outOfBounds := c.builder.CreateOr(outOfBounds1, outOfBounds2, "slice.lowmax")
+	outOfBounds = c.builder.CreateOr(outOfBounds, outOfBounds3, "slice.lowcap")
+	c.builder.CreateCondBr(outOfBounds, faultBlock, nextBlock)
+
+	// Fail: this is a nil pointer, exit with a panic.
+	c.builder.SetInsertPointAtEnd(faultBlock)
+	c.createRuntimeCall("slicePanic", nil, "")
+	c.builder.CreateUnreachable()
+
+	// Ok: this is a valid pointer.
+	c.builder.SetInsertPointAtEnd(nextBlock)
+}
+
+// emitNilCheck checks whether the given pointer is nil, and panics if it is. It
+// has no effect in well-behaved programs, but makes sure no uncaught nil
+// pointer dereferences exist in valid Go code.
+func (c *Compiler) emitNilCheck(frame *Frame, ptr llvm.Value, blockPrefix string) {
+	// Check whether we need to emit this check at all.
+	if !ptr.IsAGlobalValue().IsNil() {
+		return
+	}
+
+	// Check whether this is a nil pointer.
+	faultBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, blockPrefix+".nil")
+	nextBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, blockPrefix+".next")
+	frame.blockExits[frame.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+
+	// Compare against nil.
+	var isnil llvm.Value
+	if ptr.Type().PointerAddressSpace() == 0 {
+		// Do the nil check using the isnil builtin, which marks the parameter
+		// as nocapture.
+		// The reason it has to go through a builtin, is that a regular icmp
+		// instruction may capture the pointer in LLVM semantics, see
+		// https://reviews.llvm.org/D60047 for details. Pointer capturing
+		// unfortunately breaks escape analysis, so we use this trick to let the
+		// functionattr pass know that this pointer doesn't really escape.
+		ptr = c.builder.CreateBitCast(ptr, c.i8ptrType, "")
+		isnil = c.createRuntimeCall("isnil", []llvm.Value{ptr}, "")
+	} else {
+		// Do the nil check using a regular icmp. This can happen with function
+		// pointers on AVR, which don't benefit from escape analysis anyway.
+		nilptr := llvm.ConstPointerNull(ptr.Type())
+		isnil = c.builder.CreateICmp(llvm.IntEQ, ptr, nilptr, "")
+	}
+	c.builder.CreateCondBr(isnil, faultBlock, nextBlock)
+
+	// Fail: this is a nil pointer, exit with a panic.
+	c.builder.SetInsertPointAtEnd(faultBlock)
+	c.createRuntimeCall("nilPanic", nil, "")
+	c.builder.CreateUnreachable()
+
+	// Ok: this is a valid pointer.
+	c.builder.SetInsertPointAtEnd(nextBlock)
+}

compiler/calls.go

@@ -1,6 +1,7 @@
 package compiler
 
 import (
+	"fmt"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -20,6 +21,9 @@ func (c *Compiler) createRuntimeCall(fnName string, args []llvm.Value, name stri
 		panic("trying to call runtime." + fnName)
 	}
 	fn := c.ir.GetFunction(member.(*ssa.Function))
+	if fn.LLVMFn.IsNil() {
+		panic(fmt.Errorf("function %s does not appear in LLVM IR", fnName))
+	}
 	if !fn.IsExported() {
 		args = append(args, llvm.Undef(c.i8ptrType))            // unused context parameter
 		args = append(args, llvm.ConstPointerNull(c.i8ptrType)) // coroutine handle
@@ -38,7 +42,7 @@ func (c *Compiler) createCall(fn llvm.Value, args []llvm.Value, name string) llv
 }
 
 // Expand an argument type to a list that can be used in a function call
-// paramter list.
+// parameter list.
 func (c *Compiler) expandFormalParamType(t llvm.Type) []llvm.Type {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
@@ -55,6 +59,25 @@ func (c *Compiler) expandFormalParamType(t llvm.Type) []llvm.Type {
 	}
 }
 
+// Expand an argument type to a list of offsets from the start of the object.
+// Used together with expandFormalParam to get the offset of each value from the
+// start of the non-expanded value.
+func (c *Compiler) expandFormalParamOffsets(t llvm.Type) []uint64 {
+	switch t.TypeKind() {
+	case llvm.StructTypeKind:
+		fields := c.flattenAggregateTypeOffsets(t)
+		if len(fields) <= MaxFieldsPerParam {
+			return fields
+		} else {
+			// failed to lower
+			return []uint64{0}
+		}
+	default:
+		// TODO: split small arrays
+		return []uint64{0}
+	}
+}
+
 // Equivalent of expandFormalParamType for parameter values.
 func (c *Compiler) expandFormalParam(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
@@ -92,6 +115,27 @@ func (c *Compiler) flattenAggregateType(t llvm.Type) []llvm.Type {
 	}
 }
 
+// Return the offsets from the start of the object if this object type were
+// flattened like in flattenAggregate. Used together with flattenAggregate to
+// know the start indices of each value in the non-flattened object.
+func (c *Compiler) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
+	switch t.TypeKind() {
+	case llvm.StructTypeKind:
+		fields := make([]uint64, 0, t.StructElementTypesCount())
+		for fieldIndex, field := range t.StructElementTypes() {
+			suboffsets := c.flattenAggregateTypeOffsets(field)
+			offset := c.targetData.ElementOffset(t, fieldIndex)
+			for i := range suboffsets {
+				suboffsets[i] += offset
+			}
+			fields = append(fields, suboffsets...)
+		}
+		return fields
+	default:
+		return []uint64{0}
+	}
+}
+
 // Break down a struct into its elementary types for argument passing. The value
 // equivalent of flattenAggregateType
 func (c *Compiler) flattenAggregate(v llvm.Value) []llvm.Value {
@@ -123,10 +167,7 @@ func (c *Compiler) collapseFormalParamInternal(t llvm.Type, fields []llvm.Value)
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
 		if len(c.flattenAggregateType(t)) <= MaxFieldsPerParam {
-			value, err := c.getZeroValue(t)
-			if err != nil {
-				panic("could not get zero value of struct: " + err.Error())
-			}
+			value := llvm.ConstNull(t)
 			for i, subtyp := range t.StructElementTypes() {
 				structField, remaining := c.collapseFormalParamInternal(subtyp, fields)
 				fields = remaining

compiler/channel.go

@@ -6,92 +6,232 @@ package compiler
 import (
 	"go/types"
 
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
 
-// emitMakeChan returns a new channel value for the given channel type.
-func (c *Compiler) emitMakeChan(expr *ssa.MakeChan) (llvm.Value, error) {
-	valueType, err := c.getLLVMType(expr.Type().(*types.Chan).Elem())
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	if c.targetData.TypeAllocSize(valueType) > c.targetData.TypeAllocSize(c.intType) {
-		// Values bigger than int overflow the data part of the coroutine.
-		// TODO: make the coroutine data part big enough to hold these bigger
-		// values.
-		return llvm.Value{}, c.makeError(expr.Pos(), "todo: channel with values bigger than int")
-	}
-	chanType := c.mod.GetTypeByName("runtime.channel")
-	size := c.targetData.TypeAllocSize(chanType)
-	sizeValue := llvm.ConstInt(c.uintptrType, size, false)
-	ptr := c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "chan.alloc")
-	ptr = c.builder.CreateBitCast(ptr, llvm.PointerType(chanType, 0), "chan")
-	return ptr, nil
+func (c *Compiler) emitMakeChan(frame *Frame, expr *ssa.MakeChan) llvm.Value {
+	elementSize := c.targetData.TypeAllocSize(c.getLLVMType(expr.Type().(*types.Chan).Elem()))
+	elementSizeValue := llvm.ConstInt(c.uintptrType, elementSize, false)
+	bufSize := c.getValue(frame, expr.Size)
+	return c.createRuntimeCall("chanMake", []llvm.Value{elementSizeValue, bufSize}, "")
 }
 
 // emitChanSend emits a pseudo chan send operation. It is lowered to the actual
 // channel send operation during goroutine lowering.
-func (c *Compiler) emitChanSend(frame *Frame, instr *ssa.Send) error {
-	valueType, err := c.getLLVMType(instr.Chan.Type().(*types.Chan).Elem())
-	if err != nil {
-		return err
-	}
-	ch, err := c.parseExpr(frame, instr.Chan)
-	if err != nil {
-		return err
-	}
-	chanValue, err := c.parseExpr(frame, instr.X)
-	if err != nil {
-		return err
-	}
-	valueSize := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(chanValue.Type()), false)
-	valueAlloca := c.builder.CreateAlloca(valueType, "chan.value")
+func (c *Compiler) emitChanSend(frame *Frame, instr *ssa.Send) {
+	ch := c.getValue(frame, instr.Chan)
+	chanValue := c.getValue(frame, instr.X)
+
+	// store value-to-send
+	valueType := c.getLLVMType(instr.X.Type())
+	valueAlloca, valueAllocaCast, valueAllocaSize := c.createTemporaryAlloca(valueType, "chan.value")
 	c.builder.CreateStore(chanValue, valueAlloca)
-	valueAllocaCast := c.builder.CreateBitCast(valueAlloca, c.i8ptrType, "chan.value.i8ptr")
-	c.createRuntimeCall("chanSendStub", []llvm.Value{llvm.Undef(c.i8ptrType), ch, valueAllocaCast, valueSize}, "")
-	return nil
+
+	// Do the send.
+	c.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast}, "")
+
+	// End the lifetime of the alloca.
+	// This also works around a bug in CoroSplit, at least in LLVM 8:
+	// https://bugs.llvm.org/show_bug.cgi?id=41742
+	c.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
 }
 
 // emitChanRecv emits a pseudo chan receive operation. It is lowered to the
 // actual channel receive operation during goroutine lowering.
-func (c *Compiler) emitChanRecv(frame *Frame, unop *ssa.UnOp) (llvm.Value, error) {
-	valueType, err := c.getLLVMType(unop.X.Type().(*types.Chan).Elem())
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	valueSize := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(valueType), false)
-	ch, err := c.parseExpr(frame, unop.X)
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	valueAlloca := c.builder.CreateAlloca(valueType, "chan.value")
-	valueAllocaCast := c.builder.CreateBitCast(valueAlloca, c.i8ptrType, "chan.value.i8ptr")
-	valueOk := c.builder.CreateAlloca(c.ctx.Int1Type(), "chan.comma-ok.alloca")
-	c.createRuntimeCall("chanRecvStub", []llvm.Value{llvm.Undef(c.i8ptrType), ch, valueAllocaCast, valueOk, valueSize}, "")
+func (c *Compiler) emitChanRecv(frame *Frame, unop *ssa.UnOp) llvm.Value {
+	valueType := c.getLLVMType(unop.X.Type().(*types.Chan).Elem())
+	ch := c.getValue(frame, unop.X)
+
+	// Allocate memory to receive into.
+	valueAlloca, valueAllocaCast, valueAllocaSize := c.createTemporaryAlloca(valueType, "chan.value")
+
+	// Do the receive.
+	commaOk := c.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast}, "")
 	received := c.builder.CreateLoad(valueAlloca, "chan.received")
+	c.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
+
 	if unop.CommaOk {
-		commaOk := c.builder.CreateLoad(valueOk, "chan.comma-ok")
 		tuple := llvm.Undef(c.ctx.StructType([]llvm.Type{valueType, c.ctx.Int1Type()}, false))
 		tuple = c.builder.CreateInsertValue(tuple, received, 0, "")
 		tuple = c.builder.CreateInsertValue(tuple, commaOk, 1, "")
-		return tuple, nil
+		return tuple
 	} else {
-		return received, nil
+		return received
 	}
 }
 
 // emitChanClose closes the given channel.
-func (c *Compiler) emitChanClose(frame *Frame, param ssa.Value) error {
-	valueType, err := c.getLLVMType(param.Type().(*types.Chan).Elem())
-	valueSize := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(valueType), false)
-	if err != nil {
-		return err
-	}
-	ch, err := c.parseExpr(frame, param)
-	if err != nil {
-		return err
-	}
-	c.createRuntimeCall("chanClose", []llvm.Value{ch, valueSize}, "")
-	return nil
+func (c *Compiler) emitChanClose(frame *Frame, param ssa.Value) {
+	ch := c.getValue(frame, param)
+	c.createRuntimeCall("chanClose", []llvm.Value{ch}, "")
+}
+
+// emitSelect emits all IR necessary for a select statements. That's a
+// non-trivial amount of code because select is very complex to implement.
+func (c *Compiler) emitSelect(frame *Frame, expr *ssa.Select) llvm.Value {
+	if len(expr.States) == 0 {
+		// Shortcuts for some simple selects.
+		llvmType := c.getLLVMType(expr.Type())
+		if expr.Blocking {
+			// Blocks forever:
+			//     select {}
+			c.createRuntimeCall("deadlock", nil, "")
+			return llvm.Undef(llvmType)
+		} else {
+			// No-op:
+			//     select {
+			//     default:
+			//     }
+			retval := llvm.Undef(llvmType)
+			retval = c.builder.CreateInsertValue(retval, llvm.ConstInt(c.intType, 0xffffffffffffffff, true), 0, "")
+			return retval // {-1, false}
+		}
+	}
+
+	// This code create a (stack-allocated) slice containing all the select
+	// cases and then calls runtime.chanSelect to perform the actual select
+	// statement.
+	// Simple selects (blocking and with just one case) are already transformed
+	// into regular chan operations during SSA construction so we don't have to
+	// optimize such small selects.
+
+	// Go through all the cases. Create the selectStates slice and and
+	// determine the receive buffer size and alignment.
+	recvbufSize := uint64(0)
+	recvbufAlign := 0
+	hasReceives := false
+	var selectStates []llvm.Value
+	chanSelectStateType := c.getLLVMRuntimeType("chanSelectState")
+	for _, state := range expr.States {
+		ch := c.getValue(frame, state.Chan)
+		selectState := llvm.ConstNull(chanSelectStateType)
+		selectState = c.builder.CreateInsertValue(selectState, ch, 0, "")
+		switch state.Dir {
+		case types.RecvOnly:
+			// Make sure the receive buffer is big enough and has the correct alignment.
+			llvmType := c.getLLVMType(state.Chan.Type().(*types.Chan).Elem())
+			if size := c.targetData.TypeAllocSize(llvmType); size > recvbufSize {
+				recvbufSize = size
+			}
+			if align := c.targetData.ABITypeAlignment(llvmType); align > recvbufAlign {
+				recvbufAlign = align
+			}
+			hasReceives = true
+		case types.SendOnly:
+			// Store this value in an alloca and put a pointer to this alloca
+			// in the send state.
+			sendValue := c.getValue(frame, state.Send)
+			alloca := llvmutil.CreateEntryBlockAlloca(c.builder, sendValue.Type(), "select.send.value")
+			c.builder.CreateStore(sendValue, alloca)
+			ptr := c.builder.CreateBitCast(alloca, c.i8ptrType, "")
+			selectState = c.builder.CreateInsertValue(selectState, ptr, 1, "")
+		default:
+			panic("unreachable")
+		}
+		selectStates = append(selectStates, selectState)
+	}
+
+	// Create a receive buffer, where the received value will be stored.
+	recvbuf := llvm.Undef(c.i8ptrType)
+	if hasReceives {
+		allocaType := llvm.ArrayType(c.ctx.Int8Type(), int(recvbufSize))
+		recvbufAlloca, _, _ := c.createTemporaryAlloca(allocaType, "select.recvbuf.alloca")
+		recvbufAlloca.SetAlignment(recvbufAlign)
+		recvbuf = c.builder.CreateGEP(recvbufAlloca, []llvm.Value{
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+		}, "select.recvbuf")
+	}
+
+	// Create the states slice (allocated on the stack).
+	statesAllocaType := llvm.ArrayType(chanSelectStateType, len(selectStates))
+	statesAlloca, statesI8, statesSize := c.createTemporaryAlloca(statesAllocaType, "select.states.alloca")
+	for i, state := range selectStates {
+		// Set each slice element to the appropriate channel.
+		gep := c.builder.CreateGEP(statesAlloca, []llvm.Value{
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false),
+		}, "")
+		c.builder.CreateStore(state, gep)
+	}
+	statesPtr := c.builder.CreateGEP(statesAlloca, []llvm.Value{
+		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+	}, "select.states")
+	statesLen := llvm.ConstInt(c.uintptrType, uint64(len(selectStates)), false)
+
+	// Do the select in the runtime.
+	var results llvm.Value
+	if expr.Blocking {
+		// Stack-allocate operation structures.
+		// If these were simply created as a slice, they would heap-allocate.
+		chBlockAllocaType := llvm.ArrayType(c.getLLVMRuntimeType("channelBlockedList"), len(selectStates))
+		chBlockAlloca, chBlockAllocaPtr, chBlockSize := c.createTemporaryAlloca(chBlockAllocaType, "select.block.alloca")
+		chBlockLen := llvm.ConstInt(c.uintptrType, uint64(len(selectStates)), false)
+		chBlockPtr := c.builder.CreateGEP(chBlockAlloca, []llvm.Value{
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+		}, "select.block")
+
+		results = c.createRuntimeCall("chanSelect", []llvm.Value{
+			recvbuf,
+			statesPtr, statesLen, statesLen, // []chanSelectState
+			chBlockPtr, chBlockLen, chBlockLen, // []channelBlockList
+		}, "select.result")
+
+		// Terminate the lifetime of the operation structures.
+		c.emitLifetimeEnd(chBlockAllocaPtr, chBlockSize)
+	} else {
+		results = c.createRuntimeCall("tryChanSelect", []llvm.Value{
+			recvbuf,
+			statesPtr, statesLen, statesLen, // []chanSelectState
+		}, "select.result")
+	}
+
+	// Terminate the lifetime of the states alloca.
+	c.emitLifetimeEnd(statesI8, statesSize)
+
+	// The result value does not include all the possible received values,
+	// because we can't load them in advance. Instead, the *ssa.Extract
+	// instruction will treat a *ssa.Select specially and load it there inline.
+	// Store the receive alloca in a sidetable until we hit this extract
+	// instruction.
+	if frame.selectRecvBuf == nil {
+		frame.selectRecvBuf = make(map[*ssa.Select]llvm.Value)
+	}
+	frame.selectRecvBuf[expr] = recvbuf
+
+	return results
+}
+
+// getChanSelectResult returns the special values from a *ssa.Extract expression
+// when extracting a value from a select statement (*ssa.Select). Because
+// *ssa.Select cannot load all values in advance, it does this later in the
+// *ssa.Extract expression.
+func (c *Compiler) getChanSelectResult(frame *Frame, expr *ssa.Extract) llvm.Value {
+	if expr.Index == 0 {
+		// index
+		value := c.getValue(frame, expr.Tuple)
+		index := c.builder.CreateExtractValue(value, expr.Index, "")
+		if index.Type().IntTypeWidth() < c.intType.IntTypeWidth() {
+			index = c.builder.CreateSExt(index, c.intType, "")
+		}
+		return index
+	} else if expr.Index == 1 {
+		// comma-ok
+		value := c.getValue(frame, expr.Tuple)
+		return c.builder.CreateExtractValue(value, expr.Index, "")
+	} else {
+		// Select statements are (index, ok, ...) where ... is a number of
+		// received values, depending on how many receive statements there
+		// are. They are all combined into one alloca (because only one
+		// receive can proceed at a time) so we'll get that alloca, bitcast
+		// it to the correct type, and dereference it.
+		recvbuf := frame.selectRecvBuf[expr.Tuple.(*ssa.Select)]
+		typ := llvm.PointerType(c.getLLVMType(expr.Type()), 0)
+		ptr := c.builder.CreateBitCast(recvbuf, typ, "")
+		return c.builder.CreateLoad(ptr, "")
+	}
 }

compiler/check.go

@@ -0,0 +1,172 @@
+package compiler
+
+// This file implements a set of sanity checks for the IR that is generated.
+// It can catch some mistakes that LLVM's verifier cannot.
+
+import (
+	"errors"
+	"fmt"
+
+	"tinygo.org/x/go-llvm"
+)
+
+func (c *Compiler) checkType(t llvm.Type, checked map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// prevent infinite recursion for self-referential types
+	if _, ok := checked[t]; ok {
+		return nil
+	}
+	checked[t] = struct{}{}
+
+	// check for any context mismatches
+	switch {
+	case t.Context() == c.ctx:
+		// this is correct
+	case t.Context() == llvm.GlobalContext():
+		// somewhere we accidentally used the global context instead of a real context
+		return fmt.Errorf("type %q uses global context", t.String())
+	default:
+		// we used some other context by accident
+		return fmt.Errorf("type %q uses context %v instead of the main context %v", t.Context(), c.ctx)
+	}
+
+	// if this is a composite type, check the components of the type
+	switch t.TypeKind() {
+	case llvm.VoidTypeKind, llvm.LabelTypeKind, llvm.TokenTypeKind, llvm.MetadataTypeKind:
+		// there should only be one of any of these
+		if s, ok := specials[t.TypeKind()]; !ok {
+			specials[t.TypeKind()] = t
+		} else if s != t {
+			return fmt.Errorf("duplicate special type %q: %v and %v", t.TypeKind().String(), t, s)
+		}
+	case llvm.FloatTypeKind, llvm.DoubleTypeKind, llvm.X86_FP80TypeKind, llvm.FP128TypeKind, llvm.PPC_FP128TypeKind:
+		// floating point numbers are primitives - nothing to recurse
+	case llvm.IntegerTypeKind:
+		// integers are primitives - nothing to recurse
+	case llvm.FunctionTypeKind:
+		// check arguments and return(s)
+		for i, v := range t.ParamTypes() {
+			if err := c.checkType(v, checked, specials); err != nil {
+				return fmt.Errorf("failed to verify argument %d of type %s: %s", i, t.String(), err.Error())
+			}
+		}
+		if err := c.checkType(t.ReturnType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify return type of type %s: %s", t.String(), err.Error())
+		}
+	case llvm.StructTypeKind:
+		// check all elements
+		for i, v := range t.StructElementTypes() {
+			if err := c.checkType(v, checked, specials); err != nil {
+				return fmt.Errorf("failed to verify type of field %d of struct type %s: %s", i, t.String(), err.Error())
+			}
+		}
+	case llvm.ArrayTypeKind:
+		// check element type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify element type of array type %s: %s", t.String(), err.Error())
+		}
+	case llvm.PointerTypeKind:
+		// check underlying type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify underlying type of pointer type %s: %s", t.String(), err.Error())
+		}
+	case llvm.VectorTypeKind:
+		// check element type
+		if err := c.checkType(t.ElementType(), checked, specials); err != nil {
+			return fmt.Errorf("failed to verify element type of vector type %s: %s", t.String(), err.Error())
+		}
+	default:
+		return fmt.Errorf("unrecognized kind %q of type %s", t.TypeKind(), t.String())
+	}
+
+	return nil
+}
+
+func (c *Compiler) checkValue(v llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// check type
+	if err := c.checkType(v.Type(), types, specials); err != nil {
+		return fmt.Errorf("failed to verify type of value: %s", err.Error())
+	}
+
+	// check if this is an undefined void
+	if v.IsUndef() && v.Type().TypeKind() == llvm.VoidTypeKind {
+		return errors.New("encountered undefined void value")
+	}
+
+	return nil
+}
+
+func (c *Compiler) checkInstruction(inst llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) error {
+	// check value properties
+	if err := c.checkValue(inst, types, specials); err != nil {
+		return errorAt(inst, err.Error())
+	}
+
+	// check operands
+	for i := 0; i < inst.OperandsCount(); i++ {
+		if err := c.checkValue(inst.Operand(i), types, specials); err != nil {
+			return errorAt(inst, fmt.Sprintf("failed to validate operand %d of instruction %q: %s", i, inst.Name(), err.Error()))
+		}
+	}
+
+	return nil
+}
+
+func (c *Compiler) checkBasicBlock(bb llvm.BasicBlock, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) []error {
+	// check basic block value and type
+	var errs []error
+	if err := c.checkValue(bb.AsValue(), types, specials); err != nil {
+		errs = append(errs, errorAt(bb.Parent(), fmt.Sprintf("failed to validate value of basic block %s: %v", bb.AsValue().Name(), err)))
+	}
+
+	// check instructions
+	for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+		if err := c.checkInstruction(inst, types, specials); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	return errs
+}
+
+func (c *Compiler) checkFunction(fn llvm.Value, types map[llvm.Type]struct{}, specials map[llvm.TypeKind]llvm.Type) []error {
+	// check function value and type
+	var errs []error
+	if err := c.checkValue(fn, types, specials); err != nil {
+		errs = append(errs, fmt.Errorf("failed to validate value of function %s: %s", fn.Name(), err.Error()))
+	}
+
+	// check basic blocks
+	for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+		errs = append(errs, c.checkBasicBlock(bb, types, specials)...)
+	}
+
+	return errs
+}
+
+func (c *Compiler) checkModule() []error {
+	// check for any context mismatches
+	var errs []error
+	switch {
+	case c.mod.Context() == c.ctx:
+		// this is correct
+	case c.mod.Context() == llvm.GlobalContext():
+		// somewhere we accidentally used the global context instead of a real context
+		errs = append(errs, errors.New("module uses global context"))
+	default:
+		// we used some other context by accident
+		errs = append(errs, fmt.Errorf("module uses context %v instead of the main context %v", c.mod.Context(), c.ctx))
+	}
+
+	types := map[llvm.Type]struct{}{}
+	specials := map[llvm.TypeKind]llvm.Type{}
+	for fn := c.mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		errs = append(errs, c.checkFunction(fn, types, specials)...)
+	}
+	for g := c.mod.FirstGlobal(); !g.IsNil(); g = llvm.NextGlobal(g) {
+		if err := c.checkValue(g, types, specials); err != nil {
+			errs = append(errs, fmt.Errorf("failed to verify global %s of module: %s", g.Name(), err.Error()))
+		}
+	}
+
+	return errs
+}

compiler/defer.go

@@ -14,6 +14,7 @@ package compiler
 //     frames.
 
 import (
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"github.com/tinygo-org/tinygo/ir"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
@@ -29,14 +30,48 @@ func (c *Compiler) deferInitFunc(frame *Frame) {
 	frame.deferClosureFuncs = make(map[*ir.Function]int)
 
 	// Create defer list pointer.
-	deferType := llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)
+	deferType := llvm.PointerType(c.getLLVMRuntimeType("_defer"), 0)
 	frame.deferPtr = c.builder.CreateAlloca(deferType, "deferPtr")
 	c.builder.CreateStore(llvm.ConstPointerNull(deferType), frame.deferPtr)
 }
 
+// isInLoop checks if there is a path from a basic block to itself.
+func isInLoop(start *ssa.BasicBlock) bool {
+	// Use a breadth-first search to scan backwards through the block graph.
+	queue := []*ssa.BasicBlock{start}
+	checked := map[*ssa.BasicBlock]struct{}{}
+
+	for len(queue) > 0 {
+		// pop a block off of the queue
+		block := queue[len(queue)-1]
+		queue = queue[:len(queue)-1]
+
+		// Search through predecessors.
+		// Searching backwards means that this is pretty fast when the block is close to the start of the function.
+		// Defers are often placed near the start of the function.
+		for _, pred := range block.Preds {
+			if pred == start {
+				// cycle found
+				return true
+			}
+
+			if _, ok := checked[pred]; ok {
+				// block already checked
+				continue
+			}
+
+			// add to queue and checked map
+			queue = append(queue, pred)
+			checked[pred] = struct{}{}
+		}
+	}
+
+	return false
+}
+
 // emitDefer emits a single defer instruction, to be run when this function
 // returns.
-func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
+func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) {
 	// The pointer to the previous defer struct, which we will replace to
 	// make a linked list.
 	next := c.builder.CreateLoad(frame.deferPtr, "defer.next")
@@ -56,18 +91,12 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields, followed by the call parameters).
-		itf, err := c.parseExpr(frame, instr.Call.Value) // interface
-		if err != nil {
-			return err
-		}
+		itf := c.getValue(frame, instr.Call.Value) // interface
 		receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
 		values = []llvm.Value{callback, next, receiverValue}
 		valueTypes = append(valueTypes, c.i8ptrType)
 		for _, arg := range instr.Call.Args {
-			val, err := c.parseExpr(frame, arg)
-			if err != nil {
-				return err
-			}
+			val := c.getValue(frame, arg)
 			values = append(values, val)
 			valueTypes = append(valueTypes, val.Type())
 		}
@@ -86,10 +115,7 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 		// runtime._defer fields).
 		values = []llvm.Value{callback, next}
 		for _, param := range instr.Call.Args {
-			llvmParam, err := c.parseExpr(frame, param)
-			if err != nil {
-				return err
-			}
+			llvmParam := c.getValue(frame, param)
 			values = append(values, llvmParam)
 			valueTypes = append(valueTypes, llvmParam.Type())
 		}
@@ -101,10 +127,7 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 		// pointer.
 		// TODO: ignore this closure entirely and put pointers to the free
 		// variables directly in the defer struct, avoiding a memory allocation.
-		closure, err := c.parseExpr(frame, instr.Call.Value)
-		if err != nil {
-			return err
-		}
+		closure := c.getValue(frame, instr.Call.Value)
 		context := c.builder.CreateExtractValue(closure, 0, "")
 
 		// Get the callback number.
@@ -120,10 +143,7 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 		// context pointer).
 		values = []llvm.Value{callback, next}
 		for _, param := range instr.Call.Args {
-			llvmParam, err := c.parseExpr(frame, param)
-			if err != nil {
-				return err
-			}
+			llvmParam := c.getValue(frame, param)
 			values = append(values, llvmParam)
 			valueTypes = append(valueTypes, llvmParam.Type())
 		}
@@ -131,31 +151,41 @@ func (c *Compiler) emitDefer(frame *Frame, instr *ssa.Defer) error {
 		valueTypes = append(valueTypes, context.Type())
 
 	} else {
-		return c.makeError(instr.Pos(), "todo: defer on uncommon function call type")
+		c.addError(instr.Pos(), "todo: defer on uncommon function call type")
+		return
 	}
 
 	// Make a struct out of the collected values to put in the defer frame.
 	deferFrameType := c.ctx.StructType(valueTypes, false)
-	deferFrame, err := c.getZeroValue(deferFrameType)
-	if err != nil {
-		return err
-	}
+	deferFrame := llvm.ConstNull(deferFrameType)
 	for i, value := range values {
 		deferFrame = c.builder.CreateInsertValue(deferFrame, value, i, "")
 	}
 
-	// Put this struct in an alloca.
-	alloca := c.builder.CreateAlloca(deferFrameType, "defer.alloca")
+	// Put this struct in an allocation.
+	var alloca llvm.Value
+	if !isInLoop(instr.Block()) {
+		// This can safely use a stack allocation.
+		alloca = llvmutil.CreateEntryBlockAlloca(c.builder, deferFrameType, "defer.alloca")
+	} else {
+		// This may be hit a variable number of times, so use a heap allocation.
+		size := c.targetData.TypeAllocSize(deferFrameType)
+		sizeValue := llvm.ConstInt(c.uintptrType, size, false)
+		allocCall := c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "defer.alloc.call")
+		alloca = c.builder.CreateBitCast(allocCall, llvm.PointerType(deferFrameType, 0), "defer.alloc")
+	}
+	if c.NeedsStackObjects() {
+		c.trackPointer(alloca)
+	}
 	c.builder.CreateStore(deferFrame, alloca)
 
 	// Push it on top of the linked list by replacing deferPtr.
 	allocaCast := c.builder.CreateBitCast(alloca, next.Type(), "defer.alloca.cast")
 	c.builder.CreateStore(allocaCast, frame.deferPtr)
-	return nil
 }
 
 // emitRunDefers emits code to run all deferred functions.
-func (c *Compiler) emitRunDefers(frame *Frame) error {
+func (c *Compiler) emitRunDefers(frame *Frame) {
 	// Add a loop like the following:
 	//     for stack != nil {
 	//         _stack := stack
@@ -172,10 +202,10 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 	//     }
 
 	// Create loop.
-	loophead := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loophead")
-	loop := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loop")
-	unreachable := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.default")
-	end := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.end")
+	loophead := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loophead")
+	loop := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "rundefers.loop")
+	unreachable := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "rundefers.default")
+	end := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "rundefers.end")
 	c.builder.CreateBr(loophead)
 
 	// Create loop head:
@@ -190,13 +220,13 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 	//     stack = stack.next
 	//     switch stack.callback {
 	c.builder.SetInsertPointAtEnd(loop)
-	nextStackGEP := c.builder.CreateGEP(deferData, []llvm.Value{
+	nextStackGEP := c.builder.CreateInBoundsGEP(deferData, []llvm.Value{
 		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
 		llvm.ConstInt(c.ctx.Int32Type(), 1, false), // .next field
 	}, "stack.next.gep")
 	nextStack := c.builder.CreateLoad(nextStackGEP, "stack.next")
 	c.builder.CreateStore(nextStack, frame.deferPtr)
-	gep := c.builder.CreateGEP(deferData, []llvm.Value{
+	gep := c.builder.CreateInBoundsGEP(deferData, []llvm.Value{
 		llvm.ConstInt(c.ctx.Int32Type(), 0, false),
 		llvm.ConstInt(c.ctx.Int32Type(), 0, false), // .callback field
 	}, "callback.gep")
@@ -207,7 +237,7 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 		// Create switch case, for example:
 		//     case 0:
 		//         // run first deferred call
-		block := llvm.AddBasicBlock(frame.fn.LLVMFn, "rundefers.callback")
+		block := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "rundefers.callback")
 		sw.AddCase(llvm.ConstInt(c.uintptrType, uint64(i), false), block)
 		c.builder.SetInsertPointAtEnd(block)
 		switch callback := callback.(type) {
@@ -218,13 +248,9 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 			}
 
 			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0), c.i8ptrType}
+			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.getLLVMRuntimeType("_defer"), 0), c.i8ptrType}
 			for _, arg := range callback.Args {
-				llvmType, err := c.getLLVMType(arg.Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+				valueTypes = append(valueTypes, c.getLLVMType(arg.Type()))
 			}
 			deferFrameType := c.ctx.StructType(valueTypes, false)
 			deferFramePtr := c.builder.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
@@ -233,7 +259,7 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 			forwardParams := []llvm.Value{}
 			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 			for i := 2; i < len(valueTypes); i++ {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "gep")
+				gep := c.builder.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "gep")
 				forwardParam := c.builder.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
@@ -246,23 +272,16 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 			// Parent coroutine handle.
 			forwardParams = append(forwardParams, llvm.Undef(c.i8ptrType))
 
-			fnPtr, _, err := c.getInvokeCall(frame, callback)
-			if err != nil {
-				return err
-			}
+			fnPtr, _ := c.getInvokeCall(frame, callback)
 			c.createCall(fnPtr, forwardParams, "")
 
 		case *ir.Function:
 			// Direct call.
 
 			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)}
+			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.getLLVMRuntimeType("_defer"), 0)}
 			for _, param := range callback.Params {
-				llvmType, err := c.getLLVMType(param.Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+				valueTypes = append(valueTypes, c.getLLVMType(param.Type()))
 			}
 			deferFrameType := c.ctx.StructType(valueTypes, false)
 			deferFramePtr := c.builder.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
@@ -271,7 +290,7 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 			forwardParams := []llvm.Value{}
 			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 			for i := range callback.Params {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i+2), false)}, "gep")
+				gep := c.builder.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i+2), false)}, "gep")
 				forwardParam := c.builder.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
@@ -289,14 +308,10 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 		case *ssa.MakeClosure:
 			// Get the real defer struct type and cast to it.
 			fn := c.ir.GetFunction(callback.Fn.(*ssa.Function))
-			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)}
+			valueTypes := []llvm.Type{c.uintptrType, llvm.PointerType(c.getLLVMRuntimeType("_defer"), 0)}
 			params := fn.Signature.Params()
 			for i := 0; i < params.Len(); i++ {
-				llvmType, err := c.getLLVMType(params.At(i).Type())
-				if err != nil {
-					return err
-				}
-				valueTypes = append(valueTypes, llvmType)
+				valueTypes = append(valueTypes, c.getLLVMType(params.At(i).Type()))
 			}
 			valueTypes = append(valueTypes, c.i8ptrType) // closure
 			deferFrameType := c.ctx.StructType(valueTypes, false)
@@ -306,7 +321,7 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 			forwardParams := []llvm.Value{}
 			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 			for i := 2; i < len(valueTypes); i++ {
-				gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "")
+				gep := c.builder.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "")
 				forwardParam := c.builder.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
 			}
@@ -334,5 +349,4 @@ func (c *Compiler) emitRunDefers(frame *Frame) error {
 
 	// End of loop.
 	c.builder.SetInsertPointAtEnd(end)
-	return nil
 }

compiler/errors.go

@@ -1,8 +1,12 @@
 package compiler
 
 import (
+	"go/scanner"
 	"go/token"
 	"go/types"
+	"path/filepath"
+
+	"tinygo.org/x/go-llvm"
 )
 
 func (c *Compiler) makeError(pos token.Pos, msg string) types.Error {
@@ -12,3 +16,46 @@ func (c *Compiler) makeError(pos token.Pos, msg string) types.Error {
 		Msg:  msg,
 	}
 }
+
+func (c *Compiler) addError(pos token.Pos, msg string) {
+	c.diagnostics = append(c.diagnostics, c.makeError(pos, msg))
+}
+
+// errorAt returns an error value at the location of the instruction.
+// The location information may not be complete as it depends on debug
+// information in the IR.
+func errorAt(inst llvm.Value, msg string) scanner.Error {
+	return scanner.Error{
+		Pos: getPosition(inst),
+		Msg: msg,
+	}
+}
+
+// getPosition returns the position information for the given value, as far as
+// it is available.
+func getPosition(val llvm.Value) token.Position {
+	if !val.IsAInstruction().IsNil() {
+		loc := val.InstructionDebugLoc()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.LocationScope().ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.LocationLine()),
+			Column:   int(loc.LocationColumn()),
+		}
+	} else if !val.IsAFunction().IsNil() {
+		loc := val.Subprogram()
+		if loc.IsNil() {
+			return token.Position{}
+		}
+		file := loc.ScopeFile()
+		return token.Position{
+			Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+			Line:     int(loc.SubprogramLine()),
+		}
+	} else {
+		return token.Position{}
+	}
+}

compiler/func.go

@@ -0,0 +1,191 @@
+package compiler
+
+// This file implements function values and closures. It may need some lowering
+// in a later step, see func-lowering.go.
+
+import (
+	"go/types"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+type funcValueImplementation int
+
+const (
+	funcValueNone funcValueImplementation = iota
+
+	// A func value is implemented as a pair of pointers:
+	//     {context, function pointer}
+	// where the context may be a pointer to a heap-allocated struct containing
+	// the free variables, or it may be undef if the function being pointed to
+	// doesn't need a context. The function pointer is a regular function
+	// pointer.
+	funcValueDoubleword
+
+	// As funcValueDoubleword, but with the function pointer replaced by a
+	// unique ID per function signature. Function values are called by using a
+	// switch statement and choosing which function to call.
+	funcValueSwitch
+)
+
+// funcImplementation picks an appropriate func value implementation for the
+// target.
+func (c *Compiler) funcImplementation() funcValueImplementation {
+	// Always pick the switch implementation, as it allows the use of blocking
+	// inside a function that is used as a func value.
+	switch c.Scheduler() {
+	case "coroutines":
+		return funcValueSwitch
+	case "tasks":
+		return funcValueDoubleword
+	default:
+		panic("unknown scheduler type")
+	}
+}
+
+// createFuncValue creates a function value from a raw function pointer with no
+// context.
+func (c *Compiler) createFuncValue(funcPtr, context llvm.Value, sig *types.Signature) llvm.Value {
+	var funcValueScalar llvm.Value
+	switch c.funcImplementation() {
+	case funcValueDoubleword:
+		// Closure is: {context, function pointer}
+		funcValueScalar = funcPtr
+	case funcValueSwitch:
+		sigGlobal := c.getTypeCode(sig)
+		funcValueWithSignatureGlobalName := funcPtr.Name() + "$withSignature"
+		funcValueWithSignatureGlobal := c.mod.NamedGlobal(funcValueWithSignatureGlobalName)
+		if funcValueWithSignatureGlobal.IsNil() {
+			funcValueWithSignatureType := c.getLLVMRuntimeType("funcValueWithSignature")
+			funcValueWithSignature := llvm.ConstNamedStruct(funcValueWithSignatureType, []llvm.Value{
+				llvm.ConstPtrToInt(funcPtr, c.uintptrType),
+				sigGlobal,
+			})
+			funcValueWithSignatureGlobal = llvm.AddGlobal(c.mod, funcValueWithSignatureType, funcValueWithSignatureGlobalName)
+			funcValueWithSignatureGlobal.SetInitializer(funcValueWithSignature)
+			funcValueWithSignatureGlobal.SetGlobalConstant(true)
+			funcValueWithSignatureGlobal.SetLinkage(llvm.InternalLinkage)
+		}
+		funcValueScalar = llvm.ConstPtrToInt(funcValueWithSignatureGlobal, c.uintptrType)
+	default:
+		panic("unimplemented func value variant")
+	}
+	funcValueType := c.getFuncType(sig)
+	funcValue := llvm.Undef(funcValueType)
+	funcValue = c.builder.CreateInsertValue(funcValue, context, 0, "")
+	funcValue = c.builder.CreateInsertValue(funcValue, funcValueScalar, 1, "")
+	return funcValue
+}
+
+// extractFuncScalar returns some scalar that can be used in comparisons. It is
+// a cheap operation.
+func (c *Compiler) extractFuncScalar(funcValue llvm.Value) llvm.Value {
+	return c.builder.CreateExtractValue(funcValue, 1, "")
+}
+
+// extractFuncContext extracts the context pointer from this function value. It
+// is a cheap operation.
+func (c *Compiler) extractFuncContext(funcValue llvm.Value) llvm.Value {
+	return c.builder.CreateExtractValue(funcValue, 0, "")
+}
+
+// decodeFuncValue extracts the context and the function pointer from this func
+// value. This may be an expensive operation.
+func (c *Compiler) decodeFuncValue(funcValue llvm.Value, sig *types.Signature) (funcPtr, context llvm.Value) {
+	context = c.builder.CreateExtractValue(funcValue, 0, "")
+	switch c.funcImplementation() {
+	case funcValueDoubleword:
+		funcPtr = c.builder.CreateExtractValue(funcValue, 1, "")
+	case funcValueSwitch:
+		llvmSig := c.getRawFuncType(sig)
+		sigGlobal := c.getTypeCode(sig)
+		funcPtr = c.createRuntimeCall("getFuncPtr", []llvm.Value{funcValue, sigGlobal}, "")
+		funcPtr = c.builder.CreateIntToPtr(funcPtr, llvmSig, "")
+	default:
+		panic("unimplemented func value variant")
+	}
+	return
+}
+
+// getFuncType returns the type of a func value given a signature.
+func (c *Compiler) getFuncType(typ *types.Signature) llvm.Type {
+	switch c.funcImplementation() {
+	case funcValueDoubleword:
+		rawPtr := c.getRawFuncType(typ)
+		return c.ctx.StructType([]llvm.Type{c.i8ptrType, rawPtr}, false)
+	case funcValueSwitch:
+		return c.getLLVMRuntimeType("funcValue")
+	default:
+		panic("unimplemented func value variant")
+	}
+}
+
+// getRawFuncType returns a LLVM function pointer type for a given signature.
+func (c *Compiler) getRawFuncType(typ *types.Signature) llvm.Type {
+	// Get the return type.
+	var returnType llvm.Type
+	switch typ.Results().Len() {
+	case 0:
+		// No return values.
+		returnType = c.ctx.VoidType()
+	case 1:
+		// Just one return value.
+		returnType = c.getLLVMType(typ.Results().At(0).Type())
+	default:
+		// Multiple return values. Put them together in a struct.
+		// This appears to be the common way to handle multiple return values in
+		// LLVM.
+		members := make([]llvm.Type, typ.Results().Len())
+		for i := 0; i < typ.Results().Len(); i++ {
+			members[i] = c.getLLVMType(typ.Results().At(i).Type())
+		}
+		returnType = c.ctx.StructType(members, false)
+	}
+
+	// Get the parameter types.
+	var paramTypes []llvm.Type
+	if typ.Recv() != nil {
+		recv := c.getLLVMType(typ.Recv().Type())
+		if recv.StructName() == "runtime._interface" {
+			// This is a call on an interface, not a concrete type.
+			// The receiver is not an interface, but a i8* type.
+			recv = c.i8ptrType
+		}
+		paramTypes = append(paramTypes, c.expandFormalParamType(recv)...)
+	}
+	for i := 0; i < typ.Params().Len(); i++ {
+		subType := c.getLLVMType(typ.Params().At(i).Type())
+		paramTypes = append(paramTypes, c.expandFormalParamType(subType)...)
+	}
+	// All functions take these parameters at the end.
+	paramTypes = append(paramTypes, c.i8ptrType) // context
+	paramTypes = append(paramTypes, c.i8ptrType) // parent coroutine
+
+	// Make a func type out of the signature.
+	return llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), c.funcPtrAddrSpace)
+}
+
+// parseMakeClosure makes a function value (with context) from the given
+// closure expression.
+func (c *Compiler) parseMakeClosure(frame *Frame, expr *ssa.MakeClosure) (llvm.Value, error) {
+	if len(expr.Bindings) == 0 {
+		panic("unexpected: MakeClosure without bound variables")
+	}
+	f := c.ir.GetFunction(expr.Fn.(*ssa.Function))
+
+	// Collect all bound variables.
+	boundVars := make([]llvm.Value, len(expr.Bindings))
+	for i, binding := range expr.Bindings {
+		// The context stores the bound variables.
+		llvmBoundVar := c.getValue(frame, binding)
+		boundVars[i] = llvmBoundVar
+	}
+
+	// Store the bound variables in a single object, allocating it on the heap
+	// if necessary.
+	context := c.emitPointerPack(boundVars)
+
+	// Create the closure.
+	return c.createFuncValue(f.LLVMFn, context, f.Signature), nil
+}

compiler/gc.go

@@ -0,0 +1,106 @@
+package compiler
+
+// This file provides IR transformations necessary for precise and portable
+// garbage collectors.
+
+import (
+	"go/token"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// trackExpr inserts pointer tracking intrinsics for the GC if the expression is
+// one of the expressions that need this.
+func (c *Compiler) trackExpr(frame *Frame, expr ssa.Value, value llvm.Value) {
+	// There are uses of this expression, Make sure the pointers
+	// are tracked during GC.
+	switch expr := expr.(type) {
+	case *ssa.Alloc, *ssa.MakeChan, *ssa.MakeMap:
+		// These values are always of pointer type in IR.
+		c.trackPointer(value)
+	case *ssa.Call, *ssa.Convert, *ssa.MakeClosure, *ssa.MakeInterface, *ssa.MakeSlice, *ssa.Next:
+		if !value.IsNil() {
+			c.trackValue(value)
+		}
+	case *ssa.Select:
+		if alloca, ok := frame.selectRecvBuf[expr]; ok {
+			if alloca.IsAUndefValue().IsNil() {
+				c.trackPointer(alloca)
+			}
+		}
+	case *ssa.UnOp:
+		switch expr.Op {
+		case token.MUL:
+			// Pointer dereference.
+			c.trackValue(value)
+		case token.ARROW:
+			// Channel receive operator.
+			// It's not necessary to look at commaOk here, because in that
+			// case it's just an aggregate and trackValue will extract the
+			// pointer in there (if there is one).
+			c.trackValue(value)
+		}
+	}
+}
+
+// trackValue locates pointers in a value (possibly an aggregate) and tracks the
+// individual pointers
+func (c *Compiler) trackValue(value llvm.Value) {
+	typ := value.Type()
+	switch typ.TypeKind() {
+	case llvm.PointerTypeKind:
+		c.trackPointer(value)
+	case llvm.StructTypeKind:
+		if !typeHasPointers(typ) {
+			return
+		}
+		numElements := typ.StructElementTypesCount()
+		for i := 0; i < numElements; i++ {
+			subValue := c.builder.CreateExtractValue(value, i, "")
+			c.trackValue(subValue)
+		}
+	case llvm.ArrayTypeKind:
+		if !typeHasPointers(typ) {
+			return
+		}
+		numElements := typ.ArrayLength()
+		for i := 0; i < numElements; i++ {
+			subValue := c.builder.CreateExtractValue(value, i, "")
+			c.trackValue(subValue)
+		}
+	}
+}
+
+// trackPointer creates a call to runtime.trackPointer, bitcasting the poitner
+// first if needed. The input value must be of LLVM pointer type.
+func (c *Compiler) trackPointer(value llvm.Value) {
+	if value.Type() != c.i8ptrType {
+		value = c.builder.CreateBitCast(value, c.i8ptrType, "")
+	}
+	c.createRuntimeCall("trackPointer", []llvm.Value{value}, "")
+}
+
+// typeHasPointers returns whether this type is a pointer or contains pointers.
+// If the type is an aggregate type, it will check whether there is a pointer
+// inside.
+func typeHasPointers(t llvm.Type) bool {
+	switch t.TypeKind() {
+	case llvm.PointerTypeKind:
+		return true
+	case llvm.StructTypeKind:
+		for _, subType := range t.StructElementTypes() {
+			if typeHasPointers(subType) {
+				return true
+			}
+		}
+		return false
+	case llvm.ArrayTypeKind:
+		if typeHasPointers(t.ElementType()) {
+			return true
+		}
+		return false
+	default:
+		return false
+	}
+}

compiler/goroutine.go

@@ -0,0 +1,138 @@
+package compiler
+
+// This file implements the 'go' keyword to start a new goroutine. See
+// goroutine-lowering.go for more details.
+
+import "tinygo.org/x/go-llvm"
+
+// emitStartGoroutine starts a new goroutine with the provided function pointer
+// and parameters.
+// In general, you should pass all regular parameters plus the context parameter.
+// There is one exception: the task-based scheduler needs to have the function
+// pointer passed in as a parameter too in addition to the context.
+//
+// Because a go statement doesn't return anything, return undef.
+func (c *Compiler) emitStartGoroutine(funcPtr llvm.Value, params []llvm.Value) llvm.Value {
+	switch c.Scheduler() {
+	case "tasks":
+		paramBundle := c.emitPointerPack(params)
+		paramBundle = c.builder.CreatePtrToInt(paramBundle, c.uintptrType, "")
+
+		calleeValue := c.createGoroutineStartWrapper(funcPtr)
+		c.createRuntimeCall("startGoroutine", []llvm.Value{calleeValue, paramBundle}, "")
+	case "coroutines":
+		// We roundtrip through runtime.makeGoroutine as a signal (to find these
+		// calls) and to break any optimizations LLVM will try to do: they are
+		// invalid if we called this as a regular function to be updated later.
+		calleeValue := c.builder.CreatePtrToInt(funcPtr, c.uintptrType, "")
+		calleeValue = c.createRuntimeCall("makeGoroutine", []llvm.Value{calleeValue}, "")
+		calleeValue = c.builder.CreateIntToPtr(calleeValue, funcPtr.Type(), "")
+		c.createCall(calleeValue, append(params, llvm.ConstPointerNull(c.i8ptrType)), "")
+	default:
+		panic("unreachable")
+	}
+	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
+}
+
+// createGoroutineStartWrapper creates a wrapper for the task-based
+// implementation of goroutines. For example, to call a function like this:
+//
+//     func add(x, y int) int { ... }
+//
+// It creates a wrapper like this:
+//
+//     func add$gowrapper(ptr *unsafe.Pointer) {
+//         args := (*struct{
+//             x, y int
+//         })(ptr)
+//         add(args.x, args.y)
+//     }
+//
+// This is useful because the task-based goroutine start implementation only
+// allows a single (pointer) argument to the newly started goroutine. Also, it
+// ignores the return value because newly started goroutines do not have a
+// return value.
+func (c *Compiler) createGoroutineStartWrapper(fn llvm.Value) llvm.Value {
+	var wrapper llvm.Value
+
+	if !fn.IsAFunction().IsNil() {
+		// See whether this wrapper has already been created. If so, return it.
+		name := fn.Name()
+		wrapper = c.mod.NamedFunction(name + "$gowrapper")
+		if !wrapper.IsNil() {
+			return c.builder.CreatePtrToInt(wrapper, c.uintptrType, "")
+		}
+
+		// Save the current position in the IR builder.
+		currentBlock := c.builder.GetInsertBlock()
+		defer c.builder.SetInsertPointAtEnd(currentBlock)
+
+		// Create the wrapper.
+		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
+		wrapper = llvm.AddFunction(c.mod, name+"$gowrapper", wrapperType)
+		wrapper.SetLinkage(llvm.PrivateLinkage)
+		wrapper.SetUnnamedAddr(true)
+		entry := c.ctx.AddBasicBlock(wrapper, "entry")
+		c.builder.SetInsertPointAtEnd(entry)
+
+		// Create the list of params for the call.
+		paramTypes := fn.Type().ElementType().ParamTypes()
+		params := c.emitPointerUnpack(wrapper.Param(0), paramTypes[:len(paramTypes)-1])
+		params = append(params, llvm.Undef(c.i8ptrType))
+
+		// Create the call.
+		c.builder.CreateCall(fn, params, "")
+
+	} else {
+		// For a function pointer like this:
+		//
+		//     var funcPtr func(x, y int) int
+		//
+		// A wrapper like the following is created:
+		//
+		//     func .gowrapper(ptr *unsafe.Pointer) {
+		//         args := (*struct{
+		//             x, y int
+		//             fn   func(x, y int) int
+		//         })(ptr)
+		//         args.fn(x, y)
+		//     }
+		//
+		// With a bit of luck, identical wrapper functions like these can be
+		// merged into one.
+
+		// Save the current position in the IR builder.
+		currentBlock := c.builder.GetInsertBlock()
+		defer c.builder.SetInsertPointAtEnd(currentBlock)
+
+		// Create the wrapper.
+		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
+		wrapper = llvm.AddFunction(c.mod, ".gowrapper", wrapperType)
+		wrapper.SetLinkage(llvm.InternalLinkage)
+		wrapper.SetUnnamedAddr(true)
+		entry := c.ctx.AddBasicBlock(wrapper, "entry")
+		c.builder.SetInsertPointAtEnd(entry)
+
+		// Get the list of parameters, with the extra parameters at the end.
+		paramTypes := fn.Type().ElementType().ParamTypes()
+		paramTypes[len(paramTypes)-1] = fn.Type() // the last element is the function pointer
+		params := c.emitPointerUnpack(wrapper.Param(0), paramTypes)
+
+		// Get the function pointer.
+		fnPtr := params[len(params)-1]
+
+		// Ignore the last param, which isn't used anymore.
+		// TODO: avoid this extra "parent handle" parameter in most functions.
+		params[len(params)-1] = llvm.Undef(c.i8ptrType)
+
+		// Create the call.
+		c.builder.CreateCall(fnPtr, params, "")
+	}
+
+	// Finish the function. Every basic block must end in a terminator, and
+	// because goroutines never return a value we can simply return void.
+	c.builder.CreateRetVoid()
+
+	// Return a ptrtoint of the wrapper, not the function itself.
+	return c.builder.CreatePtrToInt(wrapper, c.uintptrType, "")
+}

compiler/inlineasm.go

@@ -0,0 +1,209 @@
+package compiler
+
+// This file implements inline asm support by calling special functions.
+
+import (
+	"fmt"
+	"go/constant"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// This is a compiler builtin, which reads the given register by name:
+//
+//     func ReadRegister(name string) uintptr
+//
+// The register name must be a constant, for example "sp".
+func (c *Compiler) emitReadRegister(name string, args []ssa.Value) (llvm.Value, error) {
+	fnType := llvm.FunctionType(c.uintptrType, []llvm.Type{}, false)
+	regname := constant.StringVal(args[0].(*ssa.Const).Value)
+	var asm string
+	switch name {
+	case "device/arm.ReadRegister":
+		asm = "mov $0, " + regname
+	case "device/riscv.ReadRegister":
+		asm = "mv $0, " + regname
+	default:
+		panic("unknown architecture")
+	}
+	target := llvm.InlineAsm(fnType, asm, "=r", false, false, 0)
+	return c.builder.CreateCall(target, nil, ""), nil
+}
+
+// This is a compiler builtin, which emits a piece of inline assembly with no
+// operands or return values. It is useful for trivial instructions, like wfi in
+// ARM or sleep in AVR.
+//
+//     func Asm(asm string)
+//
+// The provided assembly must be a constant.
+func (c *Compiler) emitAsm(args []ssa.Value) (llvm.Value, error) {
+	// Magic function: insert inline assembly instead of calling it.
+	fnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{}, false)
+	asm := constant.StringVal(args[0].(*ssa.Const).Value)
+	target := llvm.InlineAsm(fnType, asm, "", true, false, 0)
+	return c.builder.CreateCall(target, nil, ""), nil
+}
+
+// This is a compiler builtin, which allows assembly to be called in a flexible
+// way.
+//
+//     func AsmFull(asm string, regs map[string]interface{})
+//
+// The asm parameter must be a constant string. The regs parameter must be
+// provided immediately. For example:
+//
+//     arm.AsmFull(
+//         "str {value}, {result}",
+//         map[string]interface{}{
+//             "value":  1
+//             "result": &dest,
+//         })
+func (c *Compiler) emitAsmFull(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
+	asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
+	registers := map[string]llvm.Value{}
+	registerMap := instr.Args[1].(*ssa.MakeMap)
+	for _, r := range *registerMap.Referrers() {
+		switch r := r.(type) {
+		case *ssa.DebugRef:
+			// ignore
+		case *ssa.MapUpdate:
+			if r.Block() != registerMap.Block() {
+				return llvm.Value{}, c.makeError(instr.Pos(), "register value map must be created in the same basic block")
+			}
+			key := constant.StringVal(r.Key.(*ssa.Const).Value)
+			//println("value:", r.Value.(*ssa.MakeInterface).X.String())
+			registers[key] = c.getValue(frame, r.Value.(*ssa.MakeInterface).X)
+		case *ssa.Call:
+			if r.Common() == instr {
+				break
+			}
+		default:
+			return llvm.Value{}, c.makeError(instr.Pos(), "don't know how to handle argument to inline assembly: "+r.String())
+		}
+	}
+	// TODO: handle dollar signs in asm string
+	registerNumbers := map[string]int{}
+	var err error
+	argTypes := []llvm.Type{}
+	args := []llvm.Value{}
+	constraints := []string{}
+	asmString = regexp.MustCompile("\\{[a-zA-Z]+\\}").ReplaceAllStringFunc(asmString, func(s string) string {
+		// TODO: skip strings like {r4} etc. that look like ARM push/pop
+		// instructions.
+		name := s[1 : len(s)-1]
+		if _, ok := registers[name]; !ok {
+			if err == nil {
+				err = c.makeError(instr.Pos(), "unknown register name: "+name)
+			}
+			return s
+		}
+		if _, ok := registerNumbers[name]; !ok {
+			registerNumbers[name] = len(registerNumbers)
+			argTypes = append(argTypes, registers[name].Type())
+			args = append(args, registers[name])
+			switch registers[name].Type().TypeKind() {
+			case llvm.IntegerTypeKind:
+				constraints = append(constraints, "r")
+			case llvm.PointerTypeKind:
+				constraints = append(constraints, "*m")
+			default:
+				err = c.makeError(instr.Pos(), "unknown type in inline assembly for value: "+name)
+				return s
+			}
+		}
+		return fmt.Sprintf("${%v}", registerNumbers[name])
+	})
+	if err != nil {
+		return llvm.Value{}, err
+	}
+	fnType := llvm.FunctionType(c.ctx.VoidType(), argTypes, false)
+	target := llvm.InlineAsm(fnType, asmString, strings.Join(constraints, ","), true, false, 0)
+	return c.builder.CreateCall(target, args, ""), nil
+}
+
+// This is a compiler builtin which emits an inline SVCall instruction. It can
+// be one of:
+//
+//     func SVCall0(num uintptr) uintptr
+//     func SVCall1(num uintptr, a1 interface{}) uintptr
+//     func SVCall2(num uintptr, a1, a2 interface{}) uintptr
+//     func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
+//     func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr
+//
+// The num parameter must be a constant. All other parameters may be any scalar
+// value supported by LLVM inline assembly.
+func (c *Compiler) emitSVCall(frame *Frame, args []ssa.Value) (llvm.Value, error) {
+	num, _ := constant.Uint64Val(args[0].(*ssa.Const).Value)
+	llvmArgs := []llvm.Value{}
+	argTypes := []llvm.Type{}
+	asm := "svc #" + strconv.FormatUint(num, 10)
+	constraints := "={r0}"
+	for i, arg := range args[1:] {
+		arg = arg.(*ssa.MakeInterface).X
+		if i == 0 {
+			constraints += ",0"
+		} else {
+			constraints += ",{r" + strconv.Itoa(i) + "}"
+		}
+		llvmValue := c.getValue(frame, arg)
+		llvmArgs = append(llvmArgs, llvmValue)
+		argTypes = append(argTypes, llvmValue.Type())
+	}
+	// Implement the ARM calling convention by marking r1-r3 as
+	// clobbered. r0 is used as an output register so doesn't have to be
+	// marked as clobbered.
+	constraints += ",~{r1},~{r2},~{r3}"
+	fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
+	target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
+	return c.builder.CreateCall(target, llvmArgs, ""), nil
+}
+
+// This is a compiler builtin which emits CSR instructions. It can be one of:
+//
+//     func (csr CSR) Get() uintptr
+//     func (csr CSR) Set(uintptr)
+//     func (csr CSR) SetBits(uintptr) uintptr
+//     func (csr CSR) ClearBits(uintptr) uintptr
+//
+// The csr parameter (method receiver) must be a constant. Other parameter can
+// be any value.
+func (c *Compiler) emitCSROperation(frame *Frame, call *ssa.CallCommon) (llvm.Value, error) {
+	csrConst, ok := call.Args[0].(*ssa.Const)
+	if !ok {
+		return llvm.Value{}, c.makeError(call.Pos(), "CSR must be constant")
+	}
+	csr := csrConst.Uint64()
+	switch name := call.StaticCallee().Name(); name {
+	case "Get":
+		// Note that this instruction may have side effects, and thus must be
+		// marked as such.
+		fnType := llvm.FunctionType(c.uintptrType, nil, false)
+		asm := fmt.Sprintf("csrr $0, %d", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r", true, false, 0)
+		return c.builder.CreateCall(target, nil, ""), nil
+	case "Set":
+		fnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.uintptrType}, false)
+		asm := fmt.Sprintf("csrw %d, $0", csr)
+		target := llvm.InlineAsm(fnType, asm, "r", true, false, 0)
+		return c.builder.CreateCall(target, []llvm.Value{c.getValue(frame, call.Args[1])}, ""), nil
+	case "SetBits":
+		// Note: it may be possible to optimize this to csrrsi in many cases.
+		fnType := llvm.FunctionType(c.uintptrType, []llvm.Type{c.uintptrType}, false)
+		asm := fmt.Sprintf("csrrs $0, %d, $1", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r,r", true, false, 0)
+		return c.builder.CreateCall(target, []llvm.Value{c.getValue(frame, call.Args[1])}, ""), nil
+	case "ClearBits":
+		// Note: it may be possible to optimize this to csrrci in many cases.
+		fnType := llvm.FunctionType(c.uintptrType, []llvm.Type{c.uintptrType}, false)
+		asm := fmt.Sprintf("csrrc $0, %d, $1", csr)
+		target := llvm.InlineAsm(fnType, asm, "=r,r", true, false, 0)
+		return c.builder.CreateCall(target, []llvm.Value{c.getValue(frame, call.Args[1])}, ""), nil
+	default:
+		return llvm.Value{}, c.makeError(call.Pos(), "unknown CSR operation: "+name)
+	}
+}

compiler/interface.go

@@ -22,86 +22,123 @@ import (
 // value field.
 //
 // An interface value is a {typecode, value} tuple, or {i16, i8*} to be exact.
-func (c *Compiler) parseMakeInterface(val llvm.Value, typ types.Type, global string, pos token.Pos) (llvm.Value, error) {
-	var itfValue llvm.Value
-	size := c.targetData.TypeAllocSize(val.Type())
-	if size > c.targetData.TypeAllocSize(c.i8ptrType) {
-		if global != "" {
-			// Allocate in a global variable.
-			global := llvm.AddGlobal(c.mod, val.Type(), global+"$itfvalue")
-			global.SetInitializer(val)
-			global.SetLinkage(llvm.InternalLinkage)
-			global.SetGlobalConstant(true)
-			zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
-			itfValueRaw := llvm.ConstInBoundsGEP(global, []llvm.Value{zero, zero})
-			itfValue = llvm.ConstBitCast(itfValueRaw, c.i8ptrType)
-		} else {
-			// Allocate on the heap and put a pointer in the interface.
-			// TODO: escape analysis.
-			sizeValue := llvm.ConstInt(c.uintptrType, size, false)
-			alloc := c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "makeinterface.alloc")
-			itfValueCast := c.builder.CreateBitCast(alloc, llvm.PointerType(val.Type(), 0), "makeinterface.cast.value")
-			c.builder.CreateStore(val, itfValueCast)
-			itfValue = c.builder.CreateBitCast(itfValueCast, c.i8ptrType, "makeinterface.cast.i8ptr")
-		}
-	} else if size == 0 {
-		itfValue = llvm.ConstPointerNull(c.i8ptrType)
-	} else {
-		// Directly place the value in the interface.
-		switch val.Type().TypeKind() {
-		case llvm.IntegerTypeKind:
-			itfValue = c.builder.CreateIntToPtr(val, c.i8ptrType, "makeinterface.cast.int")
-		case llvm.PointerTypeKind:
-			itfValue = c.builder.CreateBitCast(val, c.i8ptrType, "makeinterface.cast.ptr")
-		case llvm.StructTypeKind, llvm.FloatTypeKind, llvm.DoubleTypeKind, llvm.VectorTypeKind:
-			// A bitcast would be useful here, but bitcast doesn't allow
-			// aggregate types. So we'll bitcast it using an alloca.
-			// Hopefully this will get optimized away.
-			mem := c.builder.CreateAlloca(c.i8ptrType, "makeinterface.cast.struct")
-			memStructPtr := c.builder.CreateBitCast(mem, llvm.PointerType(val.Type(), 0), "makeinterface.cast.struct.cast")
-			c.builder.CreateStore(val, memStructPtr)
-			itfValue = c.builder.CreateLoad(mem, "makeinterface.cast.load")
-		default:
-			return llvm.Value{}, c.makeError(pos, "todo: makeinterface: cast small type to i8*")
-		}
-	}
+func (c *Compiler) parseMakeInterface(val llvm.Value, typ types.Type, pos token.Pos) llvm.Value {
+	itfValue := c.emitPointerPack([]llvm.Value{val})
 	itfTypeCodeGlobal := c.getTypeCode(typ)
-	itfMethodSetGlobal, err := c.getTypeMethodSet(typ)
-	if err != nil {
-		return llvm.Value{}, nil
+	itfMethodSetGlobal := c.getTypeMethodSet(typ)
+	itfConcreteTypeGlobal := c.mod.NamedGlobal("typeInInterface:" + itfTypeCodeGlobal.Name())
+	if itfConcreteTypeGlobal.IsNil() {
+		typeInInterface := c.getLLVMRuntimeType("typeInInterface")
+		itfConcreteTypeGlobal = llvm.AddGlobal(c.mod, typeInInterface, "typeInInterface:"+itfTypeCodeGlobal.Name())
+		itfConcreteTypeGlobal.SetInitializer(llvm.ConstNamedStruct(typeInInterface, []llvm.Value{itfTypeCodeGlobal, itfMethodSetGlobal}))
+		itfConcreteTypeGlobal.SetGlobalConstant(true)
+		itfConcreteTypeGlobal.SetLinkage(llvm.PrivateLinkage)
 	}
-	itfTypeCode := c.createRuntimeCall("makeInterface", []llvm.Value{itfTypeCodeGlobal, itfMethodSetGlobal}, "makeinterface.typecode")
-	itf := llvm.Undef(c.mod.GetTypeByName("runtime._interface"))
+	itfTypeCode := c.builder.CreatePtrToInt(itfConcreteTypeGlobal, c.uintptrType, "")
+	itf := llvm.Undef(c.getLLVMRuntimeType("_interface"))
 	itf = c.builder.CreateInsertValue(itf, itfTypeCode, 0, "")
 	itf = c.builder.CreateInsertValue(itf, itfValue, 1, "")
-	return itf, nil
+	return itf
 }
 
 // getTypeCode returns a reference to a type code.
 // It returns a pointer to an external global which should be replaced with the
 // real type in the interface lowering pass.
 func (c *Compiler) getTypeCode(typ types.Type) llvm.Value {
-	globalName := "type:" + getTypeCodeName(typ)
+	globalName := "reflect/types.type:" + getTypeCodeName(typ)
 	global := c.mod.NamedGlobal(globalName)
 	if global.IsNil() {
-		global = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), globalName)
+		// Create a new typecode global.
+		global = llvm.AddGlobal(c.mod, c.getLLVMRuntimeType("typecodeID"), globalName)
+		// Some type classes contain more information for underlying types or
+		// element types. Store it directly in the typecode global to make
+		// reflect lowering simpler.
+		var references llvm.Value
+		var length int64
+		switch typ := typ.(type) {
+		case *types.Named:
+			references = c.getTypeCode(typ.Underlying())
+		case *types.Chan:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Pointer:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Slice:
+			references = c.getTypeCode(typ.Elem())
+		case *types.Array:
+			references = c.getTypeCode(typ.Elem())
+			length = typ.Len()
+		case *types.Struct:
+			// Take a pointer to the typecodeID of the first field (if it exists).
+			structGlobal := c.makeStructTypeFields(typ)
+			references = llvm.ConstBitCast(structGlobal, global.Type())
+		}
+		if !references.IsNil() {
+			// Set the 'references' field of the runtime.typecodeID struct.
+			globalValue := llvm.ConstNull(global.Type().ElementType())
+			globalValue = llvm.ConstInsertValue(globalValue, references, []uint32{0})
+			if length != 0 {
+				lengthValue := llvm.ConstInt(c.uintptrType, uint64(length), false)
+				globalValue = llvm.ConstInsertValue(globalValue, lengthValue, []uint32{1})
+			}
+			global.SetInitializer(globalValue)
+			global.SetLinkage(llvm.PrivateLinkage)
+		}
 		global.SetGlobalConstant(true)
 	}
 	return global
 }
 
+// makeStructTypeFields creates a new global that stores all type information
+// related to this struct type, and returns the resulting global. This global is
+// actually an array of all the fields in the structs.
+func (c *Compiler) makeStructTypeFields(typ *types.Struct) llvm.Value {
+	// The global is an array of runtime.structField structs.
+	runtimeStructField := c.getLLVMRuntimeType("structField")
+	structGlobalType := llvm.ArrayType(runtimeStructField, typ.NumFields())
+	structGlobal := llvm.AddGlobal(c.mod, structGlobalType, "reflect/types.structFields")
+	structGlobalValue := llvm.ConstNull(structGlobalType)
+	for i := 0; i < typ.NumFields(); i++ {
+		fieldGlobalValue := llvm.ConstNull(runtimeStructField)
+		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, c.getTypeCode(typ.Field(i).Type()), []uint32{0})
+		fieldName := c.makeGlobalArray([]byte(typ.Field(i).Name()), "reflect/types.structFieldName", c.ctx.Int8Type())
+		fieldName.SetLinkage(llvm.PrivateLinkage)
+		fieldName.SetUnnamedAddr(true)
+		fieldName = llvm.ConstGEP(fieldName, []llvm.Value{
+			llvm.ConstInt(llvm.Int32Type(), 0, false),
+			llvm.ConstInt(llvm.Int32Type(), 0, false),
+		})
+		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldName, []uint32{1})
+		if typ.Tag(i) != "" {
+			fieldTag := c.makeGlobalArray([]byte(typ.Tag(i)), "reflect/types.structFieldTag", c.ctx.Int8Type())
+			fieldTag.SetLinkage(llvm.PrivateLinkage)
+			fieldTag.SetUnnamedAddr(true)
+			fieldTag = llvm.ConstGEP(fieldTag, []llvm.Value{
+				llvm.ConstInt(llvm.Int32Type(), 0, false),
+				llvm.ConstInt(llvm.Int32Type(), 0, false),
+			})
+			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldTag, []uint32{2})
+		}
+		if typ.Field(i).Embedded() {
+			fieldEmbedded := llvm.ConstInt(c.ctx.Int1Type(), 1, false)
+			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldEmbedded, []uint32{3})
+		}
+		structGlobalValue = llvm.ConstInsertValue(structGlobalValue, fieldGlobalValue, []uint32{uint32(i)})
+	}
+	structGlobal.SetInitializer(structGlobalValue)
+	structGlobal.SetUnnamedAddr(true)
+	structGlobal.SetLinkage(llvm.PrivateLinkage)
+	return structGlobal
+}
+
 // getTypeCodeName returns a name for this type that can be used in the
 // interface lowering pass to assign type codes as expected by the reflect
 // package. See getTypeCodeNum.
 func getTypeCodeName(t types.Type) string {
-	name := ""
-	if named, ok := t.(*types.Named); ok {
-		name = "~" + named.String() + ":"
-		t = t.Underlying()
-	}
 	switch t := t.(type) {
+	case *types.Named:
+		return "named:" + t.String()
 	case *types.Array:
-		return "array:" + name + strconv.FormatInt(t.Len(), 10) + ":" + getTypeCodeName(t.Elem())
+		return "array:" + strconv.FormatInt(t.Len(), 10) + ":" + getTypeCodeName(t.Elem())
 	case *types.Basic:
 		var kind string
 		switch t.Kind() {
@@ -144,21 +181,21 @@ func getTypeCodeName(t types.Type) string {
 		default:
 			panic("unknown basic type: " + t.Name())
 		}
-		return "basic:" + name + kind
+		return "basic:" + kind
 	case *types.Chan:
-		return "chan:" + name + getTypeCodeName(t.Elem())
+		return "chan:" + getTypeCodeName(t.Elem())
 	case *types.Interface:
 		methods := make([]string, t.NumMethods())
 		for i := 0; i < t.NumMethods(); i++ {
 			methods[i] = getTypeCodeName(t.Method(i).Type())
 		}
-		return "interface:" + name + "{" + strings.Join(methods, ",") + "}"
+		return "interface:" + "{" + strings.Join(methods, ",") + "}"
 	case *types.Map:
 		keyType := getTypeCodeName(t.Key())
 		elemType := getTypeCodeName(t.Elem())
-		return "map:" + name + "{" + keyType + "," + elemType + "}"
+		return "map:" + "{" + keyType + "," + elemType + "}"
 	case *types.Pointer:
-		return "pointer:" + name + getTypeCodeName(t.Elem())
+		return "pointer:" + getTypeCodeName(t.Elem())
 	case *types.Signature:
 		params := make([]string, t.Params().Len())
 		for i := 0; i < t.Params().Len(); i++ {
@@ -168,15 +205,22 @@ func getTypeCodeName(t types.Type) string {
 		for i := 0; i < t.Results().Len(); i++ {
 			results[i] = getTypeCodeName(t.Results().At(i).Type())
 		}
-		return "func:" + name + "{" + strings.Join(params, ",") + "}{" + strings.Join(results, ",") + "}"
+		return "func:" + "{" + strings.Join(params, ",") + "}{" + strings.Join(results, ",") + "}"
 	case *types.Slice:
-		return "slice:" + name + getTypeCodeName(t.Elem())
+		return "slice:" + getTypeCodeName(t.Elem())
 	case *types.Struct:
 		elems := make([]string, t.NumFields())
 		for i := 0; i < t.NumFields(); i++ {
-			elems[i] = getTypeCodeName(t.Field(i).Type())
+			embedded := ""
+			if t.Field(i).Embedded() {
+				embedded = "#"
+			}
+			elems[i] = embedded + t.Field(i).Name() + ":" + getTypeCodeName(t.Field(i).Type())
+			if t.Tag(i) != "" {
+				elems[i] += "`" + t.Tag(i) + "`"
+			}
 		}
-		return "struct:" + name + "{" + strings.Join(elems, ",") + "}"
+		return "struct:" + "{" + strings.Join(elems, ",") + "}"
 	default:
 		panic("unknown type: " + t.String())
 	}
@@ -184,22 +228,22 @@ func getTypeCodeName(t types.Type) string {
 
 // getTypeMethodSet returns a reference (GEP) to a global method set. This
 // method set should be unreferenced after the interface lowering pass.
-func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
+func (c *Compiler) getTypeMethodSet(typ types.Type) llvm.Value {
 	global := c.mod.NamedGlobal(typ.String() + "$methodset")
 	zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
 	if !global.IsNil() {
 		// the method set already exists
-		return llvm.ConstGEP(global, []llvm.Value{zero, zero}), nil
+		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}
 
 	ms := c.ir.Program.MethodSets.MethodSet(typ)
 	if ms.Len() == 0 {
 		// no methods, so can leave that one out
-		return llvm.ConstPointerNull(llvm.PointerType(c.mod.GetTypeByName("runtime.interfaceMethodInfo"), 0)), nil
+		return llvm.ConstPointerNull(llvm.PointerType(c.getLLVMRuntimeType("interfaceMethodInfo"), 0))
 	}
 
 	methods := make([]llvm.Value, ms.Len())
-	interfaceMethodInfoType := c.mod.GetTypeByName("runtime.interfaceMethodInfo")
+	interfaceMethodInfoType := c.getLLVMRuntimeType("interfaceMethodInfo")
 	for i := 0; i < ms.Len(); i++ {
 		method := ms.At(i)
 		signatureGlobal := c.getMethodSignature(method.Obj().(*types.Func))
@@ -208,13 +252,10 @@ func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
 			// compiler error, so panic
 			panic("cannot find function: " + f.LinkName())
 		}
-		fn, err := c.getInterfaceInvokeWrapper(f)
-		if err != nil {
-			return llvm.Value{}, err
-		}
+		fn := c.getInterfaceInvokeWrapper(f)
 		methodInfo := llvm.ConstNamedStruct(interfaceMethodInfoType, []llvm.Value{
 			signatureGlobal,
-			llvm.ConstBitCast(fn, c.i8ptrType),
+			llvm.ConstPtrToInt(fn, c.uintptrType),
 		})
 		methods[i] = methodInfo
 	}
@@ -224,7 +265,7 @@ func (c *Compiler) getTypeMethodSet(typ types.Type) (llvm.Value, error) {
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
 	global.SetLinkage(llvm.PrivateLinkage)
-	return llvm.ConstGEP(global, []llvm.Value{zero, zero}), nil
+	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }
 
 // getInterfaceMethodSet returns a global variable with the method set of the
@@ -238,14 +279,14 @@ func (c *Compiler) getInterfaceMethodSet(typ *types.Named) llvm.Value {
 		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}
 
-	// Every method is a *i16 reference indicating the signature of this method.
+	// Every method is a *i8 reference indicating the signature of this method.
 	methods := make([]llvm.Value, typ.Underlying().(*types.Interface).NumMethods())
 	for i := range methods {
 		method := typ.Underlying().(*types.Interface).Method(i)
 		methods[i] = c.getMethodSignature(method)
 	}
 
-	value := llvm.ConstArray(methods[0].Type(), methods)
+	value := llvm.ConstArray(c.i8ptrType, methods)
 	global = llvm.AddGlobal(c.mod, value.Type(), typ.String()+"$interface")
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
@@ -254,7 +295,7 @@ func (c *Compiler) getInterfaceMethodSet(typ *types.Named) llvm.Value {
 }
 
 // getMethodSignature returns a global variable which is a reference to an
-// external *i16 indicating the indicating the signature of this method. It is
+// external *i8 indicating the indicating the signature of this method. It is
 // used during the interface lowering pass.
 func (c *Compiler) getMethodSignature(method *types.Func) llvm.Value {
 	signature := ir.MethodSignature(method)
@@ -273,19 +314,9 @@ func (c *Compiler) getMethodSignature(method *types.Func) llvm.Value {
 //
 // Type asserts on concrete types are trivial: just compare type numbers. Type
 // asserts on interfaces are more difficult, see the comments in the function.
-func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Value, error) {
-	itf, err := c.parseExpr(frame, expr.X)
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	assertedType, err := c.getLLVMType(expr.AssertedType)
-	if err != nil {
-		return llvm.Value{}, err
-	}
-	valueNil, err := c.getZeroValue(assertedType)
-	if err != nil {
-		return llvm.Value{}, err
-	}
+func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) llvm.Value {
+	itf := c.getValue(frame, expr.X)
+	assertedType := c.getLLVMType(expr.AssertedType)
 
 	actualTypeNum := c.builder.CreateExtractValue(itf, 0, "interface.type")
 	commaOk := llvm.Value{}
@@ -338,71 +369,35 @@ func (c *Compiler) parseTypeAssert(frame *Frame, expr *ssa.TypeAssert) (llvm.Val
 		// Type assert on concrete type. Extract the underlying type from
 		// the interface (but only after checking it matches).
 		valuePtr := c.builder.CreateExtractValue(itf, 1, "typeassert.value.ptr")
-		size := c.targetData.TypeAllocSize(assertedType)
-		if size > c.targetData.TypeAllocSize(c.i8ptrType) {
-			// Value was stored in an allocated buffer, load it from there.
-			valuePtrCast := c.builder.CreateBitCast(valuePtr, llvm.PointerType(assertedType, 0), "")
-			valueOk = c.builder.CreateLoad(valuePtrCast, "typeassert.value.ok")
-		} else if size == 0 {
-			valueOk, err = c.getZeroValue(assertedType)
-			if err != nil {
-				return llvm.Value{}, err
-			}
-		} else {
-			// Value was stored directly in the interface.
-			switch assertedType.TypeKind() {
-			case llvm.IntegerTypeKind:
-				valueOk = c.builder.CreatePtrToInt(valuePtr, assertedType, "typeassert.value.ok")
-			case llvm.PointerTypeKind:
-				valueOk = c.builder.CreateBitCast(valuePtr, assertedType, "typeassert.value.ok")
-			default: // struct, float, etc.
-				// A bitcast would be useful here, but bitcast doesn't allow
-				// aggregate types. So we'll bitcast it using an alloca.
-				// Hopefully this will get optimized away.
-				mem := c.builder.CreateAlloca(c.i8ptrType, "")
-				c.builder.CreateStore(valuePtr, mem)
-				memCast := c.builder.CreateBitCast(mem, llvm.PointerType(assertedType, 0), "")
-				valueOk = c.builder.CreateLoad(memCast, "typeassert.value.ok")
-			}
-		}
+		valueOk = c.emitPointerUnpack(valuePtr, []llvm.Type{assertedType})[0]
 	}
 	c.builder.CreateBr(nextBlock)
 
 	// Continue after the if statement.
 	c.builder.SetInsertPointAtEnd(nextBlock)
 	phi := c.builder.CreatePHI(assertedType, "typeassert.value")
-	phi.AddIncoming([]llvm.Value{valueNil, valueOk}, []llvm.BasicBlock{prevBlock, okBlock})
+	phi.AddIncoming([]llvm.Value{llvm.ConstNull(assertedType), valueOk}, []llvm.BasicBlock{prevBlock, okBlock})
 
 	if expr.CommaOk {
 		tuple := c.ctx.ConstStruct([]llvm.Value{llvm.Undef(assertedType), llvm.Undef(c.ctx.Int1Type())}, false) // create empty tuple
 		tuple = c.builder.CreateInsertValue(tuple, phi, 0, "")                                                  // insert value
 		tuple = c.builder.CreateInsertValue(tuple, commaOk, 1, "")                                              // insert 'comma ok' boolean
-		return tuple, nil
+		return tuple
 	} else {
 		// This is kind of dirty as the branch above becomes mostly useless,
 		// but hopefully this gets optimized away.
 		c.createRuntimeCall("interfaceTypeAssert", []llvm.Value{commaOk}, "")
-		return phi, nil
+		return phi
 	}
 }
 
 // getInvokeCall creates and returns the function pointer and parameters of an
 // interface call. It can be used in a call or defer instruction.
-func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Value, []llvm.Value, error) {
+func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Value, []llvm.Value) {
 	// Call an interface method with dynamic dispatch.
-	itf, err := c.parseExpr(frame, instr.Value) // interface
-	if err != nil {
-		return llvm.Value{}, nil, err
-	}
+	itf := c.getValue(frame, instr.Value) // interface
 
-	llvmFnType, err := c.getLLVMType(instr.Method.Type())
-	if err != nil {
-		return llvm.Value{}, nil, err
-	}
-	// getLLVMType() has created a closure type for us, but we don't actually
-	// want a closure type as an interface call can never be a closure call. So
-	// extract the function pointer type from the closure.
-	llvmFnType = llvmFnType.Subtypes()[1]
+	llvmFnType := c.getRawFuncType(instr.Method.Type().(*types.Signature))
 
 	typecode := c.builder.CreateExtractValue(itf, 0, "invoke.typecode")
 	values := []llvm.Value{
@@ -411,16 +406,12 @@ func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Valu
 		c.getMethodSignature(instr.Method),
 	}
 	fn := c.createRuntimeCall("interfaceMethod", values, "invoke.func")
-	fnCast := c.builder.CreateBitCast(fn, llvmFnType, "invoke.func.cast")
+	fnCast := c.builder.CreateIntToPtr(fn, llvmFnType, "invoke.func.cast")
 	receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
 
 	args := []llvm.Value{receiverValue}
 	for _, arg := range instr.Args {
-		val, err := c.parseExpr(frame, arg)
-		if err != nil {
-			return llvm.Value{}, nil, err
-		}
-		args = append(args, val)
+		args = append(args, c.getValue(frame, arg))
 	}
 	// Add the context parameter. An interface call never takes a context but we
 	// have to supply the parameter anyway.
@@ -428,7 +419,7 @@ func (c *Compiler) getInvokeCall(frame *Frame, instr *ssa.CallCommon) (llvm.Valu
 	// Add the parent goroutine handle.
 	args = append(args, llvm.Undef(c.i8ptrType))
 
-	return fnCast, args, nil
+	return fnCast, args
 }
 
 // interfaceInvokeWrapper keeps some state between getInterfaceInvokeWrapper and
@@ -444,19 +435,16 @@ type interfaceInvokeWrapper struct {
 // the underlying value, dereferences it, and calls the real method. This
 // wrapper is only needed when the interface value actually doesn't fit in a
 // pointer and a pointer to the value must be created.
-func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) (llvm.Value, error) {
+func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
 	wrapperName := f.LinkName() + "$invoke"
 	wrapper := c.mod.NamedFunction(wrapperName)
 	if !wrapper.IsNil() {
 		// Wrapper already created. Return it directly.
-		return wrapper, nil
+		return wrapper
 	}
 
 	// Get the expanded receiver type.
-	receiverType, err := c.getLLVMType(f.Params[0].Type())
-	if err != nil {
-		return llvm.Value{}, err
-	}
+	receiverType := c.getLLVMType(f.Params[0].Type())
 	expandedReceiverType := c.expandFormalParamType(receiverType)
 
 	// Does this method even need any wrapping?
@@ -465,7 +453,7 @@ func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) (llvm.Value, error)
 		// Casting a function signature to a different signature and calling it
 		// with a receiver pointer bitcasted to *i8 (as done in calls on an
 		// interface) is hopefully a safe (defined) operation.
-		return f.LLVMFn, nil
+		return f.LLVMFn
 	}
 
 	// create wrapper function
@@ -473,17 +461,20 @@ func (c *Compiler) getInterfaceInvokeWrapper(f *ir.Function) (llvm.Value, error)
 	paramTypes := append([]llvm.Type{c.i8ptrType}, fnType.ParamTypes()[len(expandedReceiverType):]...)
 	wrapFnType := llvm.FunctionType(fnType.ReturnType(), paramTypes, false)
 	wrapper = llvm.AddFunction(c.mod, wrapperName, wrapFnType)
+	if f.LLVMFn.LastParam().Name() == "parentHandle" {
+		wrapper.LastParam().SetName("parentHandle")
+	}
 	c.interfaceInvokeWrappers = append(c.interfaceInvokeWrappers, interfaceInvokeWrapper{
 		fn:           f,
 		wrapper:      wrapper,
 		receiverType: receiverType,
 	})
-	return wrapper, nil
+	return wrapper
 }
 
 // createInterfaceInvokeWrapper finishes the work of getInterfaceInvokeWrapper,
 // see that function for details.
-func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) error {
+func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) {
 	wrapper := state.wrapper
 	fn := state.fn
 	receiverType := state.receiverType
@@ -491,12 +482,9 @@ func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) er
 	wrapper.SetUnnamedAddr(true)
 
 	// add debug info if needed
-	if c.Debug {
+	if c.Debug() {
 		pos := c.ir.Program.Fset.Position(fn.Pos())
-		difunc, err := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
-		if err != nil {
-			return err
-		}
+		difunc := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
 		c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 	}
 
@@ -504,28 +492,7 @@ func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) er
 	block := c.ctx.AddBasicBlock(wrapper, "entry")
 	c.builder.SetInsertPointAtEnd(block)
 
-	var receiverPtr llvm.Value
-	if c.targetData.TypeAllocSize(receiverType) > c.targetData.TypeAllocSize(c.i8ptrType) {
-		// The receiver is passed in using a pointer. We have to load it here
-		// and pass it by value to the real function.
-
-		// Load the underlying value.
-		receiverPtrType := llvm.PointerType(receiverType, 0)
-		receiverPtr = c.builder.CreateBitCast(wrapper.Param(0), receiverPtrType, "receiver.ptr")
-	} else {
-		// The value is stored in the interface, but it is of type struct which
-		// is expanded to multiple parameters (e.g. {i8, i8}). So we have to
-		// receive the struct as parameter, expand it, and pass it on to the
-		// real function.
-
-		// Cast the passed-in i8* to the struct value (using an alloca) and
-		// extract its values.
-		alloca := c.builder.CreateAlloca(c.i8ptrType, "receiver.alloca")
-		c.builder.CreateStore(wrapper.Param(0), alloca)
-		receiverPtr = c.builder.CreateBitCast(alloca, llvm.PointerType(receiverType, 0), "receiver.ptr")
-	}
-
-	receiverValue := c.builder.CreateLoad(receiverPtr, "receiver")
+	receiverValue := c.emitPointerUnpack(wrapper.Param(0), []llvm.Type{receiverType})[0]
 	params := append(c.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
 	if fn.LLVMFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
 		c.builder.CreateCall(fn.LLVMFn, params, "")
@@ -534,6 +501,4 @@ func (c *Compiler) createInterfaceInvokeWrapper(state interfaceInvokeWrapper) er
 		ret := c.builder.CreateCall(fn.LLVMFn, params, "ret")
 		c.builder.CreateRet(ret)
 	}
-
-	return nil
 }

compiler/interrupt.go

@@ -0,0 +1,92 @@
+package compiler
+
+import (
+	"strconv"
+	"strings"
+
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// emitInterruptGlobal creates a new runtime/interrupt.Interrupt struct that
+// will be lowered to a real interrupt during interrupt lowering.
+//
+// This two-stage approach allows unused interrupts to be optimized away if
+// necessary.
+func (c *Compiler) emitInterruptGlobal(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
+	// Get the interrupt number, which must be a compile-time constant.
+	id, ok := instr.Args[0].(*ssa.Const)
+	if !ok {
+		return llvm.Value{}, c.makeError(instr.Pos(), "interrupt ID is not a constant")
+	}
+
+	// Get the func value, which also must be a compile time constant.
+	// Note that bound functions are allowed if the function has a pointer
+	// receiver and is a global. This is rather strict but still allows for
+	// idiomatic Go code.
+	funcValue := c.getValue(frame, instr.Args[1])
+	if funcValue.IsAConstant().IsNil() {
+		// Try to determine the cause of the non-constantness for a nice error
+		// message.
+		switch instr.Args[1].(type) {
+		case *ssa.MakeClosure:
+			// This may also be a bound method.
+			return llvm.Value{}, c.makeError(instr.Pos(), "closures are not supported in interrupt.New")
+		}
+		// Fall back to a generic error.
+		return llvm.Value{}, c.makeError(instr.Pos(), "interrupt function must be constant")
+	}
+
+	// Create a new global of type runtime/interrupt.handle. Globals of this
+	// type are lowered in the interrupt lowering pass.
+	globalType := c.ir.Program.ImportedPackage("runtime/interrupt").Type("handle").Type()
+	globalLLVMType := c.getLLVMType(globalType)
+	globalName := "runtime/interrupt.$interrupt" + strconv.FormatInt(id.Int64(), 10)
+	if global := c.mod.NamedGlobal(globalName); !global.IsNil() {
+		return llvm.Value{}, c.makeError(instr.Pos(), "interrupt redeclared in this program")
+	}
+	global := llvm.AddGlobal(c.mod, globalLLVMType, globalName)
+	global.SetLinkage(llvm.PrivateLinkage)
+	global.SetGlobalConstant(true)
+	global.SetUnnamedAddr(true)
+	initializer := llvm.ConstNull(globalLLVMType)
+	initializer = llvm.ConstInsertValue(initializer, funcValue, []uint32{0})
+	initializer = llvm.ConstInsertValue(initializer, llvm.ConstInt(c.intType, uint64(id.Int64()), true), []uint32{1, 0})
+	global.SetInitializer(initializer)
+
+	// Add debug info to the interrupt global.
+	if c.Debug() {
+		pos := c.ir.Program.Fset.Position(instr.Pos())
+		diglobal := c.dibuilder.CreateGlobalVariableExpression(c.difiles[pos.Filename], llvm.DIGlobalVariableExpression{
+			Name:        "interrupt" + strconv.FormatInt(id.Int64(), 10),
+			LinkageName: globalName,
+			File:        c.getDIFile(pos.Filename),
+			Line:        pos.Line,
+			Type:        c.getDIType(globalType),
+			Expr:        c.dibuilder.CreateExpression(nil),
+			LocalToUnit: false,
+		})
+		global.AddMetadata(0, diglobal)
+	}
+
+	// Create the runtime/interrupt.Interrupt type. It is a struct with a single
+	// member of type int.
+	num := llvm.ConstPtrToInt(global, c.intType)
+	interrupt := llvm.ConstNamedStruct(c.mod.GetTypeByName("runtime/interrupt.Interrupt"), []llvm.Value{num})
+
+	// Add dummy "use" call for AVR, because interrupts may be used even though
+	// they are never referenced again. This is unlike Cortex-M or the RISC-V
+	// PLIC where each interrupt must be enabled using the interrupt number, and
+	// thus keeps the Interrupt object alive.
+	// This call is removed during interrupt lowering.
+	if strings.HasPrefix(c.Triple(), "avr") {
+		useFn := c.mod.NamedFunction("runtime/interrupt.use")
+		if useFn.IsNil() {
+			useFnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{interrupt.Type()}, false)
+			useFn = llvm.AddFunction(c.mod, "runtime/interrupt.use", useFnType)
+		}
+		c.builder.CreateCall(useFn, []llvm.Value{interrupt}, "")
+	}
+
+	return interrupt, nil
+}

compiler/llvm.go

@@ -1,6 +1,7 @@
 package compiler
 
 import (
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"tinygo.org/x/go-llvm"
 )
 
@@ -22,74 +23,47 @@ func getUses(value llvm.Value) []llvm.Value {
 	return uses
 }
 
-// splitBasicBlock splits a LLVM basic block into two parts. All instructions
-// after afterInst are moved into a new basic block (created right after the
-// current one) with the given name.
-func (c *Compiler) splitBasicBlock(afterInst llvm.Value, insertAfter llvm.BasicBlock, name string) llvm.BasicBlock {
-	oldBlock := afterInst.InstructionParent()
-	newBlock := c.ctx.InsertBasicBlock(insertAfter, name)
-	var nextInstructions []llvm.Value // values to move
-
-	// Collect to-be-moved instructions.
-	inst := afterInst
-	for {
-		inst = llvm.NextInstruction(inst)
-		if inst.IsNil() {
-			break
-		}
-		nextInstructions = append(nextInstructions, inst)
-	}
-
-	// Move instructions.
-	c.builder.SetInsertPointAtEnd(newBlock)
-	for _, inst := range nextInstructions {
-		inst.RemoveFromParentAsInstruction()
-		c.builder.Insert(inst)
-	}
-
-	// Find PHI nodes to update.
-	var phiNodes []llvm.Value // PHI nodes to update
-	for bb := insertAfter.Parent().FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
-		for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
-			if inst.IsAPHINode().IsNil() {
-				continue
-			}
-			needsUpdate := false
-			incomingCount := inst.IncomingCount()
-			for i := 0; i < incomingCount; i++ {
-				if inst.IncomingBlock(i) == oldBlock {
-					needsUpdate = true
-					break
-				}
-			}
-			if !needsUpdate {
-				// PHI node has no incoming edge from the old block.
-				continue
-			}
-			phiNodes = append(phiNodes, inst)
-		}
-	}
-
-	// Update PHI nodes.
-	for _, phi := range phiNodes {
-		c.builder.SetInsertPointBefore(phi)
-		newPhi := c.builder.CreatePHI(phi.Type(), "")
-		incomingCount := phi.IncomingCount()
-		incomingVals := make([]llvm.Value, incomingCount)
-		incomingBlocks := make([]llvm.BasicBlock, incomingCount)
-		for i := 0; i < incomingCount; i++ {
-			value := phi.IncomingValue(i)
-			block := phi.IncomingBlock(i)
-			if block == oldBlock {
-				block = newBlock
-			}
-			incomingVals[i] = value
-			incomingBlocks[i] = block
-		}
-		newPhi.AddIncoming(incomingVals, incomingBlocks)
-		phi.ReplaceAllUsesWith(newPhi)
-		phi.EraseFromParentAsInstruction()
-	}
-
-	return newBlock
+// createTemporaryAlloca creates a new alloca in the entry block and adds
+// lifetime start infromation in the IR signalling that the alloca won't be used
+// before this point.
+//
+// This is useful for creating temporary allocas for intrinsics. Don't forget to
+// end the lifetime using emitLifetimeEnd after you're done with it.
+func (c *Compiler) createTemporaryAlloca(t llvm.Type, name string) (alloca, bitcast, size llvm.Value) {
+	return llvmutil.CreateTemporaryAlloca(c.builder, c.mod, t, name)
+}
+
+// emitLifetimeEnd signals the end of an (alloca) lifetime by calling the
+// llvm.lifetime.end intrinsic. It is commonly used together with
+// createTemporaryAlloca.
+func (c *Compiler) emitLifetimeEnd(ptr, size llvm.Value) {
+	llvmutil.EmitLifetimeEnd(c.builder, c.mod, ptr, size)
+}
+
+// emitPointerPack packs the list of values into a single pointer value using
+// bitcasts, or else allocates a value on the heap if it cannot be packed in the
+// pointer value directly. It returns the pointer with the packed data.
+func (c *Compiler) emitPointerPack(values []llvm.Value) llvm.Value {
+	return llvmutil.EmitPointerPack(c.builder, c.mod, c.Config, values)
+}
+
+// emitPointerUnpack extracts a list of values packed using emitPointerPack.
+func (c *Compiler) emitPointerUnpack(ptr llvm.Value, valueTypes []llvm.Type) []llvm.Value {
+	return llvmutil.EmitPointerUnpack(c.builder, c.mod, ptr, valueTypes)
+}
+
+// makeGlobalArray creates a new LLVM global with the given name and integers as
+// contents, and returns the global.
+// Note that it is left with the default linkage etc., you should set
+// linkage/constant/etc properties yourself.
+func (c *Compiler) makeGlobalArray(buf []byte, name string, elementType llvm.Type) llvm.Value {
+	globalType := llvm.ArrayType(elementType, len(buf))
+	global := llvm.AddGlobal(c.mod, globalType, name)
+	value := llvm.Undef(globalType)
+	for i := 0; i < len(buf); i++ {
+		ch := uint64(buf[i])
+		value = llvm.ConstInsertValue(value, llvm.ConstInt(elementType, ch, false), []uint32{uint32(i)})
+	}
+	global.SetInitializer(value)
+	return global
 }

compiler/llvmutil/llvm.go

@@ -0,0 +1,168 @@
+// Package llvmutil contains utility functions used across multiple compiler
+// packages. For example, they may be used by both the compiler pacakge and
+// transformation packages.
+//
+// Normally, utility packages are avoided. However, in this case, the utility
+// functions are non-trivial and hard to get right. Copying them to multiple
+// places would be a big risk if only one of them is updated.
+package llvmutil
+
+import "tinygo.org/x/go-llvm"
+
+// CreateEntryBlockAlloca creates a new alloca in the entry block, even though
+// the IR builder is located elsewhere. It assumes that the insert point is
+// at the end of the current block.
+func CreateEntryBlockAlloca(builder llvm.Builder, t llvm.Type, name string) llvm.Value {
+	currentBlock := builder.GetInsertBlock()
+	entryBlock := currentBlock.Parent().EntryBasicBlock()
+	if entryBlock.FirstInstruction().IsNil() {
+		builder.SetInsertPointAtEnd(entryBlock)
+	} else {
+		builder.SetInsertPointBefore(entryBlock.FirstInstruction())
+	}
+	alloca := builder.CreateAlloca(t, name)
+	builder.SetInsertPointAtEnd(currentBlock)
+	return alloca
+}
+
+// CreateTemporaryAlloca creates a new alloca in the entry block and adds
+// lifetime start infromation in the IR signalling that the alloca won't be used
+// before this point.
+//
+// This is useful for creating temporary allocas for intrinsics. Don't forget to
+// end the lifetime using emitLifetimeEnd after you're done with it.
+func CreateTemporaryAlloca(builder llvm.Builder, mod llvm.Module, t llvm.Type, name string) (alloca, bitcast, size llvm.Value) {
+	ctx := t.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	alloca = CreateEntryBlockAlloca(builder, t, name)
+	bitcast = builder.CreateBitCast(alloca, i8ptrType, name+".bitcast")
+	size = llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(t), false)
+	builder.CreateCall(getLifetimeStartFunc(mod), []llvm.Value{size, bitcast}, "")
+	return
+}
+
+// CreateInstructionAlloca creates an alloca in the entry block, and places lifetime control intrinsics around the instruction
+func CreateInstructionAlloca(builder llvm.Builder, mod llvm.Module, t llvm.Type, inst llvm.Value, name string) llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+
+	alloca := CreateEntryBlockAlloca(builder, t, name)
+	builder.SetInsertPointBefore(inst)
+	bitcast := builder.CreateBitCast(alloca, i8ptrType, name+".bitcast")
+	size := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(t), false)
+	builder.CreateCall(getLifetimeStartFunc(mod), []llvm.Value{size, bitcast}, "")
+	if next := llvm.NextInstruction(inst); !next.IsNil() {
+		builder.SetInsertPointBefore(next)
+	} else {
+		builder.SetInsertPointAtEnd(inst.InstructionParent())
+	}
+	builder.CreateCall(getLifetimeEndFunc(mod), []llvm.Value{size, bitcast}, "")
+	return alloca
+}
+
+// EmitLifetimeEnd signals the end of an (alloca) lifetime by calling the
+// llvm.lifetime.end intrinsic. It is commonly used together with
+// createTemporaryAlloca.
+func EmitLifetimeEnd(builder llvm.Builder, mod llvm.Module, ptr, size llvm.Value) {
+	builder.CreateCall(getLifetimeEndFunc(mod), []llvm.Value{size, ptr}, "")
+}
+
+// getLifetimeStartFunc returns the llvm.lifetime.start intrinsic and creates it
+// first if it doesn't exist yet.
+func getLifetimeStartFunc(mod llvm.Module) llvm.Value {
+	fn := mod.NamedFunction("llvm.lifetime.start.p0i8")
+	ctx := mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	if fn.IsNil() {
+		fnType := llvm.FunctionType(ctx.VoidType(), []llvm.Type{ctx.Int64Type(), i8ptrType}, false)
+		fn = llvm.AddFunction(mod, "llvm.lifetime.start.p0i8", fnType)
+	}
+	return fn
+}
+
+// getLifetimeEndFunc returns the llvm.lifetime.end intrinsic and creates it
+// first if it doesn't exist yet.
+func getLifetimeEndFunc(mod llvm.Module) llvm.Value {
+	fn := mod.NamedFunction("llvm.lifetime.end.p0i8")
+	ctx := mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	if fn.IsNil() {
+		fnType := llvm.FunctionType(ctx.VoidType(), []llvm.Type{ctx.Int64Type(), i8ptrType}, false)
+		fn = llvm.AddFunction(mod, "llvm.lifetime.end.p0i8", fnType)
+	}
+	return fn
+}
+
+// SplitBasicBlock splits a LLVM basic block into two parts. All instructions
+// after afterInst are moved into a new basic block (created right after the
+// current one) with the given name.
+func SplitBasicBlock(builder llvm.Builder, afterInst llvm.Value, insertAfter llvm.BasicBlock, name string) llvm.BasicBlock {
+	oldBlock := afterInst.InstructionParent()
+	newBlock := afterInst.Type().Context().InsertBasicBlock(insertAfter, name)
+	var nextInstructions []llvm.Value // values to move
+
+	// Collect to-be-moved instructions.
+	inst := afterInst
+	for {
+		inst = llvm.NextInstruction(inst)
+		if inst.IsNil() {
+			break
+		}
+		nextInstructions = append(nextInstructions, inst)
+	}
+
+	// Move instructions.
+	builder.SetInsertPointAtEnd(newBlock)
+	for _, inst := range nextInstructions {
+		inst.RemoveFromParentAsInstruction()
+		builder.Insert(inst)
+	}
+
+	// Find PHI nodes to update.
+	var phiNodes []llvm.Value // PHI nodes to update
+	for bb := insertAfter.Parent().FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+		for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+			if inst.IsAPHINode().IsNil() {
+				continue
+			}
+			needsUpdate := false
+			incomingCount := inst.IncomingCount()
+			for i := 0; i < incomingCount; i++ {
+				if inst.IncomingBlock(i) == oldBlock {
+					needsUpdate = true
+					break
+				}
+			}
+			if !needsUpdate {
+				// PHI node has no incoming edge from the old block.
+				continue
+			}
+			phiNodes = append(phiNodes, inst)
+		}
+	}
+
+	// Update PHI nodes.
+	for _, phi := range phiNodes {
+		builder.SetInsertPointBefore(phi)
+		newPhi := builder.CreatePHI(phi.Type(), "")
+		incomingCount := phi.IncomingCount()
+		incomingVals := make([]llvm.Value, incomingCount)
+		incomingBlocks := make([]llvm.BasicBlock, incomingCount)
+		for i := 0; i < incomingCount; i++ {
+			value := phi.IncomingValue(i)
+			block := phi.IncomingBlock(i)
+			if block == oldBlock {
+				block = newBlock
+			}
+			incomingVals[i] = value
+			incomingBlocks[i] = block
+		}
+		newPhi.AddIncoming(incomingVals, incomingBlocks)
+		phi.ReplaceAllUsesWith(newPhi)
+		phi.EraseFromParentAsInstruction()
+	}
+
+	return newBlock
+}

compiler/llvmutil/wordpack.go

@@ -0,0 +1,141 @@
+package llvmutil
+
+// This file contains utility functions to pack and unpack sets of values. It
+// can take in a list of values and tries to store it efficiently in the pointer
+// itself if possible and legal.
+
+import (
+	"github.com/tinygo-org/tinygo/compileopts"
+	"tinygo.org/x/go-llvm"
+)
+
+// EmitPointerPack packs the list of values into a single pointer value using
+// bitcasts, or else allocates a value on the heap if it cannot be packed in the
+// pointer value directly. It returns the pointer with the packed data.
+func EmitPointerPack(builder llvm.Builder, mod llvm.Module, config *compileopts.Config, values []llvm.Value) llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+	uintptrType := ctx.IntType(llvm.NewTargetData(mod.DataLayout()).PointerSize() * 8)
+
+	valueTypes := make([]llvm.Type, len(values))
+	for i, value := range values {
+		valueTypes[i] = value.Type()
+	}
+	packedType := ctx.StructType(valueTypes, false)
+
+	// Allocate memory for the packed data.
+	var packedAlloc, packedHeapAlloc llvm.Value
+	size := targetData.TypeAllocSize(packedType)
+	if size == 0 {
+		return llvm.ConstPointerNull(i8ptrType)
+	} else if len(values) == 1 && values[0].Type().TypeKind() == llvm.PointerTypeKind {
+		return builder.CreateBitCast(values[0], i8ptrType, "pack.ptr")
+	} else if size <= targetData.TypeAllocSize(i8ptrType) {
+		// Packed data fits in a pointer, so store it directly inside the
+		// pointer.
+		if len(values) == 1 && values[0].Type().TypeKind() == llvm.IntegerTypeKind {
+			// Try to keep this cast in SSA form.
+			return builder.CreateIntToPtr(values[0], i8ptrType, "pack.int")
+		}
+		// Because packedType is a struct and we have to cast it to a *i8, store
+		// it in an alloca first for bitcasting (store+bitcast+load).
+		packedAlloc, _, _ = CreateTemporaryAlloca(builder, mod, packedType, "")
+	} else {
+		// Packed data is bigger than a pointer, so allocate it on the heap.
+		sizeValue := llvm.ConstInt(uintptrType, size, false)
+		alloc := mod.NamedFunction("runtime.alloc")
+		packedHeapAlloc = builder.CreateCall(alloc, []llvm.Value{
+			sizeValue,
+			llvm.Undef(i8ptrType),            // unused context parameter
+			llvm.ConstPointerNull(i8ptrType), // coroutine handle
+		}, "")
+		if config.NeedsStackObjects() {
+			trackPointer := mod.NamedFunction("runtime.trackPointer")
+			builder.CreateCall(trackPointer, []llvm.Value{
+				packedHeapAlloc,
+				llvm.Undef(i8ptrType),            // unused context parameter
+				llvm.ConstPointerNull(i8ptrType), // coroutine handle
+			}, "")
+		}
+		packedAlloc = builder.CreateBitCast(packedHeapAlloc, llvm.PointerType(packedType, 0), "")
+	}
+	// Store all values in the alloca or heap pointer.
+	for i, value := range values {
+		indices := []llvm.Value{
+			llvm.ConstInt(ctx.Int32Type(), 0, false),
+			llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
+		}
+		gep := builder.CreateInBoundsGEP(packedAlloc, indices, "")
+		builder.CreateStore(value, gep)
+	}
+
+	if packedHeapAlloc.IsNil() {
+		// Load value (as *i8) from the alloca.
+		packedAlloc = builder.CreateBitCast(packedAlloc, llvm.PointerType(i8ptrType, 0), "")
+		result := builder.CreateLoad(packedAlloc, "")
+		packedPtr := builder.CreateBitCast(packedAlloc, i8ptrType, "")
+		packedSize := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(packedAlloc.Type()), false)
+		EmitLifetimeEnd(builder, mod, packedPtr, packedSize)
+		return result
+	} else {
+		// Get the original heap allocation pointer, which already is an *i8.
+		return packedHeapAlloc
+	}
+}
+
+// EmitPointerUnpack extracts a list of values packed using EmitPointerPack.
+func EmitPointerUnpack(builder llvm.Builder, mod llvm.Module, ptr llvm.Value, valueTypes []llvm.Type) []llvm.Value {
+	ctx := mod.Context()
+	targetData := llvm.NewTargetData(mod.DataLayout())
+	i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+	uintptrType := ctx.IntType(llvm.NewTargetData(mod.DataLayout()).PointerSize() * 8)
+
+	packedType := ctx.StructType(valueTypes, false)
+
+	// Get a correctly-typed pointer to the packed data.
+	var packedAlloc, packedRawAlloc llvm.Value
+	size := targetData.TypeAllocSize(packedType)
+	if size == 0 {
+		// No data to unpack.
+	} else if len(valueTypes) == 1 && valueTypes[0].TypeKind() == llvm.PointerTypeKind {
+		// A single pointer is always stored directly.
+		return []llvm.Value{builder.CreateBitCast(ptr, valueTypes[0], "unpack.ptr")}
+	} else if size <= targetData.TypeAllocSize(i8ptrType) {
+		// Packed data stored directly in pointer.
+		if len(valueTypes) == 1 && valueTypes[0].TypeKind() == llvm.IntegerTypeKind {
+			// Keep this cast in SSA form.
+			return []llvm.Value{builder.CreatePtrToInt(ptr, valueTypes[0], "unpack.int")}
+		}
+		// Fallback: load it using an alloca.
+		packedRawAlloc, _, _ = CreateTemporaryAlloca(builder, mod, llvm.PointerType(i8ptrType, 0), "unpack.raw.alloc")
+		packedRawValue := builder.CreateBitCast(ptr, llvm.PointerType(i8ptrType, 0), "unpack.raw.value")
+		builder.CreateStore(packedRawValue, packedRawAlloc)
+		packedAlloc = builder.CreateBitCast(packedRawAlloc, llvm.PointerType(packedType, 0), "unpack.alloc")
+	} else {
+		// Packed data stored on the heap. Bitcast the passed-in pointer to the
+		// correct pointer type.
+		packedAlloc = builder.CreateBitCast(ptr, llvm.PointerType(packedType, 0), "unpack.raw.ptr")
+	}
+	// Load each value from the packed data.
+	values := make([]llvm.Value, len(valueTypes))
+	for i, valueType := range valueTypes {
+		if targetData.TypeAllocSize(valueType) == 0 {
+			// This value has length zero, so there's nothing to load.
+			values[i] = llvm.ConstNull(valueType)
+			continue
+		}
+		indices := []llvm.Value{
+			llvm.ConstInt(ctx.Int32Type(), 0, false),
+			llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
+		}
+		gep := builder.CreateInBoundsGEP(packedAlloc, indices, "")
+		values[i] = builder.CreateLoad(gep, "")
+	}
+	if !packedRawAlloc.IsNil() {
+		allocPtr := builder.CreateBitCast(packedRawAlloc, i8ptrType, "")
+		allocSize := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(uintptrType), false)
+		EmitLifetimeEnd(builder, mod, allocPtr, allocSize)
+	}
+	return values
+}

compiler/map.go

@@ -6,32 +6,86 @@ import (
 	"go/token"
 	"go/types"
 
+	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
 
-func (c *Compiler) emitMapLookup(keyType, valueType types.Type, m, key llvm.Value, commaOk bool, pos token.Pos) (llvm.Value, error) {
-	llvmValueType, err := c.getLLVMType(valueType)
-	if err != nil {
-		return llvm.Value{}, err
+// emitMakeMap creates a new map object (runtime.hashmap) by allocating and
+// initializing an appropriately sized object.
+func (c *Compiler) emitMakeMap(frame *Frame, expr *ssa.MakeMap) (llvm.Value, error) {
+	mapType := expr.Type().Underlying().(*types.Map)
+	keyType := mapType.Key().Underlying()
+	llvmValueType := c.getLLVMType(mapType.Elem().Underlying())
+	var llvmKeyType llvm.Type
+	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
+		// String keys.
+		llvmKeyType = c.getLLVMType(keyType)
+	} else if hashmapIsBinaryKey(keyType) {
+		// Trivially comparable keys.
+		llvmKeyType = c.getLLVMType(keyType)
+	} else {
+		// All other keys. Implemented as map[interface{}]valueType for ease of
+		// implementation.
+		llvmKeyType = c.getLLVMRuntimeType("_interface")
 	}
-	mapValueAlloca := c.builder.CreateAlloca(llvmValueType, "hashmap.value")
-	mapValuePtr := c.builder.CreateBitCast(mapValueAlloca, c.i8ptrType, "hashmap.valueptr")
+	keySize := c.targetData.TypeAllocSize(llvmKeyType)
+	valueSize := c.targetData.TypeAllocSize(llvmValueType)
+	llvmKeySize := llvm.ConstInt(c.ctx.Int8Type(), keySize, false)
+	llvmValueSize := llvm.ConstInt(c.ctx.Int8Type(), valueSize, false)
+	sizeHint := llvm.ConstInt(c.uintptrType, 8, false)
+	if expr.Reserve != nil {
+		sizeHint = c.getValue(frame, expr.Reserve)
+		var err error
+		sizeHint, err = c.parseConvert(expr.Reserve.Type(), types.Typ[types.Uintptr], sizeHint, expr.Pos())
+		if err != nil {
+			return llvm.Value{}, err
+		}
+	}
+	hashmap := c.createRuntimeCall("hashmapMake", []llvm.Value{llvmKeySize, llvmValueSize, sizeHint}, "")
+	return hashmap, nil
+}
+
+func (c *Compiler) emitMapLookup(keyType, valueType types.Type, m, key llvm.Value, commaOk bool, pos token.Pos) (llvm.Value, error) {
+	llvmValueType := c.getLLVMType(valueType)
+
+	// Allocate the memory for the resulting type. Do not zero this memory: it
+	// will be zeroed by the hashmap get implementation if the key is not
+	// present in the map.
+	mapValueAlloca, mapValuePtr, mapValueSize := c.createTemporaryAlloca(llvmValueType, "hashmap.value")
+
+	// Do the lookup. How it is done depends on the key type.
 	var commaOkValue llvm.Value
+	keyType = keyType.Underlying()
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// key is a string
 		params := []llvm.Value{m, key, mapValuePtr}
 		commaOkValue = c.createRuntimeCall("hashmapStringGet", params, "")
 	} else if hashmapIsBinaryKey(keyType) {
 		// key can be compared with runtime.memequal
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
-		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
-		params := []llvm.Value{m, keyPtr, mapValuePtr}
+		// Store the key in an alloca, in the entry block to avoid dynamic stack
+		// growth.
+		mapKeyAlloca, mapKeyPtr, mapKeySize := c.createTemporaryAlloca(key.Type(), "hashmap.key")
+		c.builder.CreateStore(key, mapKeyAlloca)
+		// Fetch the value from the hashmap.
+		params := []llvm.Value{m, mapKeyPtr, mapValuePtr}
 		commaOkValue = c.createRuntimeCall("hashmapBinaryGet", params, "")
+		c.emitLifetimeEnd(mapKeyPtr, mapKeySize)
 	} else {
-		return llvm.Value{}, c.makeError(pos, "only strings, bools, ints or structs of bools/ints are supported as map keys, but got: "+keyType.String())
+		// Not trivially comparable using memcmp. Make it an interface instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface now.
+			itfKey = c.parseMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey, mapValuePtr}
+		commaOkValue = c.createRuntimeCall("hashmapInterfaceGet", params, "")
 	}
+
+	// Load the resulting value from the hashmap. The value is set to the zero
+	// value if the key doesn't exist in the hashmap.
 	mapValue := c.builder.CreateLoad(mapValueAlloca, "")
+	c.emitLifetimeEnd(mapValuePtr, mapValueSize)
+
 	if commaOk {
 		tuple := llvm.Undef(c.ctx.StructType([]llvm.Type{llvmValueType, c.ctx.Int1Type()}, false))
 		tuple = c.builder.CreateInsertValue(tuple, mapValue, 0, "")
@@ -42,27 +96,32 @@ func (c *Compiler) emitMapLookup(keyType, valueType types.Type, m, key llvm.Valu
 	}
 }
 
-func (c *Compiler) emitMapUpdate(keyType types.Type, m, key, value llvm.Value, pos token.Pos) error {
-	valueAlloca := c.builder.CreateAlloca(value.Type(), "hashmap.value")
+func (c *Compiler) emitMapUpdate(keyType types.Type, m, key, value llvm.Value, pos token.Pos) {
+	valueAlloca, valuePtr, valueSize := c.createTemporaryAlloca(value.Type(), "hashmap.value")
 	c.builder.CreateStore(value, valueAlloca)
-	valuePtr := c.builder.CreateBitCast(valueAlloca, c.i8ptrType, "hashmap.valueptr")
 	keyType = keyType.Underlying()
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// key is a string
 		params := []llvm.Value{m, key, valuePtr}
 		c.createRuntimeCall("hashmapStringSet", params, "")
-		return nil
 	} else if hashmapIsBinaryKey(keyType) {
 		// key can be compared with runtime.memequal
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
+		keyAlloca, keyPtr, keySize := c.createTemporaryAlloca(key.Type(), "hashmap.key")
 		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
 		params := []llvm.Value{m, keyPtr, valuePtr}
 		c.createRuntimeCall("hashmapBinarySet", params, "")
-		return nil
+		c.emitLifetimeEnd(keyPtr, keySize)
 	} else {
-		return c.makeError(pos, "only strings, bools, ints or structs of bools/ints are supported as map keys, but got: "+keyType.String())
+		// Key is not trivially comparable, so compare it as an interface instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface first.
+			itfKey = c.parseMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey, valuePtr}
+		c.createRuntimeCall("hashmapInterfaceSet", params, "")
 	}
+	c.emitLifetimeEnd(valuePtr, valueSize)
 }
 
 func (c *Compiler) emitMapDelete(keyType types.Type, m, key llvm.Value, pos token.Pos) error {
@@ -73,45 +132,34 @@ func (c *Compiler) emitMapDelete(keyType types.Type, m, key llvm.Value, pos toke
 		c.createRuntimeCall("hashmapStringDelete", params, "")
 		return nil
 	} else if hashmapIsBinaryKey(keyType) {
-		keyAlloca := c.builder.CreateAlloca(key.Type(), "hashmap.key")
+		keyAlloca, keyPtr, keySize := c.createTemporaryAlloca(key.Type(), "hashmap.key")
 		c.builder.CreateStore(key, keyAlloca)
-		keyPtr := c.builder.CreateBitCast(keyAlloca, c.i8ptrType, "hashmap.keyptr")
 		params := []llvm.Value{m, keyPtr}
 		c.createRuntimeCall("hashmapBinaryDelete", params, "")
+		c.emitLifetimeEnd(keyPtr, keySize)
 		return nil
 	} else {
-		return c.makeError(pos, "only strings, bools, ints or structs of bools/ints are supported as map keys, but got: "+keyType.String())
+		// Key is not trivially comparable, so compare it as an interface
+		// instead.
+		itfKey := key
+		if _, ok := keyType.(*types.Interface); !ok {
+			// Not already an interface, so convert it to an interface first.
+			itfKey = c.parseMakeInterface(key, keyType, pos)
+		}
+		params := []llvm.Value{m, itfKey}
+		c.createRuntimeCall("hashmapInterfaceDelete", params, "")
+		return nil
 	}
 }
 
-// Get FNV-1a hash of this string.
-//
-// https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
-func hashmapHash(data []byte) uint32 {
-	var result uint32 = 2166136261 // FNV offset basis
-	for _, c := range data {
-		result ^= uint32(c)
-		result *= 16777619 // FNV prime
-	}
-	return result
-}
-
-// Get the topmost 8 bits of the hash, without using a special value (like 0).
-func hashmapTopHash(hash uint32) uint8 {
-	tophash := uint8(hash >> 24)
-	if tophash < 1 {
-		// 0 means empty slot, so make it bigger.
-		tophash += 1
-	}
-	return tophash
-}
-
 // Returns true if this key type does not contain strings, interfaces etc., so
 // can be compared with runtime.memequal.
 func hashmapIsBinaryKey(keyType types.Type) bool {
 	switch keyType := keyType.(type) {
 	case *types.Basic:
 		return keyType.Info()&(types.IsBoolean|types.IsInteger) != 0
+	case *types.Pointer:
+		return true
 	case *types.Struct:
 		for i := 0; i < keyType.NumFields(); i++ {
 			fieldType := keyType.Field(i).Type().Underlying()

compiler/optimizer.go

@@ -3,12 +3,13 @@ package compiler
 import (
 	"errors"
 
+	"github.com/tinygo-org/tinygo/transform"
 	"tinygo.org/x/go-llvm"
 )
 
 // Run the LLVM optimizer over the module.
 // The inliner can be disabled (if necessary) by passing 0 to the inlinerThreshold.
-func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) error {
+func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) []error {
 	builder := llvm.NewPassManagerBuilder()
 	defer builder.Dispose()
 	builder.SetOptLevel(optLevel)
@@ -18,6 +19,18 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 	}
 	builder.AddCoroutinePassesToExtensionPoints()
 
+	if c.PanicStrategy() == "trap" {
+		transform.ReplacePanicsWithTrap(c.mod) // -panic=trap
+	}
+
+	// run a check of all of our code
+	if c.VerifyIR() {
+		errs := c.checkModule()
+		if errs != nil {
+			return errs
+		}
+	}
+
 	// Run function passes for each function.
 	funcPasses := llvm.NewFunctionPassManagerForModule(c.mod)
 	defer funcPasses.Dispose()
@@ -32,6 +45,7 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 		// Run some preparatory passes for the Go optimizer.
 		goPasses := llvm.NewPassManager()
 		defer goPasses.Dispose()
+		goPasses.AddGlobalDCEPass()
 		goPasses.AddGlobalOptimizerPass()
 		goPasses.AddConstantPropagationPass()
 		goPasses.AddAggressiveDCEPass()
@@ -39,10 +53,19 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 		goPasses.Run(c.mod)
 
 		// Run Go-specific optimization passes.
-		c.OptimizeMaps()
-		c.OptimizeStringToBytes()
-		c.OptimizeAllocs()
-		c.LowerInterfaces()
+		transform.OptimizeMaps(c.mod)
+		transform.OptimizeStringToBytes(c.mod)
+		transform.OptimizeAllocs(c.mod)
+		transform.LowerInterfaces(c.mod)
+
+		errs := transform.LowerInterrupts(c.mod)
+		if len(errs) > 0 {
+			return errs
+		}
+
+		if c.funcImplementation() == funcValueSwitch {
+			transform.LowerFuncValues(c.mod)
+		}
 
 		// After interfaces are lowered, there are many more opportunities for
 		// interprocedural optimizations. To get them to work, function
@@ -50,23 +73,51 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 		goPasses.Run(c.mod)
 
 		// Run TinyGo-specific interprocedural optimizations.
-		c.OptimizeAllocs()
-		c.OptimizeStringToBytes()
+		transform.OptimizeAllocs(c.mod)
+		transform.OptimizeStringToBytes(c.mod)
+
+		// Lower runtime.isnil calls to regular nil comparisons.
+		isnil := c.mod.NamedFunction("runtime.isnil")
+		if !isnil.IsNil() {
+			for _, use := range getUses(isnil) {
+				c.builder.SetInsertPointBefore(use)
+				ptr := use.Operand(0)
+				if !ptr.IsABitCastInst().IsNil() {
+					ptr = ptr.Operand(0)
+				}
+				nilptr := llvm.ConstPointerNull(ptr.Type())
+				icmp := c.builder.CreateICmp(llvm.IntEQ, ptr, nilptr, "")
+				use.ReplaceAllUsesWith(icmp)
+				use.EraseFromParentAsInstruction()
+			}
+		}
 
 		err := c.LowerGoroutines()
 		if err != nil {
-			return err
+			return []error{err}
 		}
 	} else {
 		// Must be run at any optimization level.
-		c.LowerInterfaces()
+		transform.LowerInterfaces(c.mod)
+		if c.funcImplementation() == funcValueSwitch {
+			transform.LowerFuncValues(c.mod)
+		}
 		err := c.LowerGoroutines()
 		if err != nil {
-			return err
+			return []error{err}
+		}
+		errs := transform.LowerInterrupts(c.mod)
+		if len(errs) > 0 {
+			return errs
+		}
+	}
+	if c.VerifyIR() {
+		if errs := c.checkModule(); errs != nil {
+			return errs
 		}
 	}
 	if err := c.Verify(); err != nil {
-		return errors.New("optimizations caused a verification failure")
+		return []error{errors.New("optimizations caused a verification failure")}
 	}
 
 	if sizeLevel >= 2 {
@@ -79,6 +130,15 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 		}
 	}
 
+	// After TinyGo-specific transforms have finished, undo exporting these functions.
+	for _, name := range c.getFunctionsUsedInTransforms() {
+		fn := c.mod.NamedFunction(name)
+		if fn.IsNil() {
+			continue
+		}
+		fn.SetLinkage(llvm.InternalLinkage)
+	}
+
 	// Run function passes again, because without it, llvm.coro.size.i32()
 	// doesn't get lowered.
 	for fn := c.mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
@@ -92,251 +152,13 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int, inlinerThreshold uint) erro
 	builder.Populate(modPasses)
 	modPasses.Run(c.mod)
 
+	hasGCPass := transform.AddGlobalsBitmap(c.mod)
+	hasGCPass = transform.MakeGCStackSlots(c.mod) || hasGCPass
+	if hasGCPass {
+		if err := c.Verify(); err != nil {
+			return []error{errors.New("GC pass caused a verification failure")}
+		}
+	}
+
 	return nil
 }
-
-// Eliminate created but not used maps.
-//
-// In the future, this should statically allocate created but never modified
-// maps. This has not yet been implemented, however.
-func (c *Compiler) OptimizeMaps() {
-	hashmapMake := c.mod.NamedFunction("runtime.hashmapMake")
-	if hashmapMake.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	hashmapBinarySet := c.mod.NamedFunction("runtime.hashmapBinarySet")
-	hashmapStringSet := c.mod.NamedFunction("runtime.hashmapStringSet")
-
-	for _, makeInst := range getUses(hashmapMake) {
-		updateInsts := []llvm.Value{}
-		unknownUses := false // are there any uses other than setting a value?
-
-		for _, use := range getUses(makeInst) {
-			if use := use.IsACallInst(); !use.IsNil() {
-				switch use.CalledValue() {
-				case hashmapBinarySet, hashmapStringSet:
-					updateInsts = append(updateInsts, use)
-				default:
-					unknownUses = true
-				}
-			} else {
-				unknownUses = true
-			}
-		}
-
-		if !unknownUses {
-			// This map can be entirely removed, as it is only created but never
-			// used.
-			for _, inst := range updateInsts {
-				inst.EraseFromParentAsInstruction()
-			}
-			makeInst.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Transform runtime.stringToBytes(...) calls into const []byte slices whenever
-// possible. This optimizes the following pattern:
-//     w.Write([]byte("foo"))
-// where Write does not store to the slice.
-func (c *Compiler) OptimizeStringToBytes() {
-	stringToBytes := c.mod.NamedFunction("runtime.stringToBytes")
-	if stringToBytes.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	for _, call := range getUses(stringToBytes) {
-		strptr := call.Operand(0)
-		strlen := call.Operand(1)
-
-		// strptr is always constant because strings are always constant.
-
-		convertedAllUses := true
-		for _, use := range getUses(call) {
-			nilValue := llvm.Value{}
-			if use.IsAExtractValueInst() == nilValue {
-				convertedAllUses = false
-				continue
-			}
-			switch use.Type().TypeKind() {
-			case llvm.IntegerTypeKind:
-				// A length (len or cap). Propagate the length value.
-				use.ReplaceAllUsesWith(strlen)
-				use.EraseFromParentAsInstruction()
-			case llvm.PointerTypeKind:
-				// The string pointer itself.
-				if !c.isReadOnly(use) {
-					convertedAllUses = false
-					continue
-				}
-				use.ReplaceAllUsesWith(strptr)
-				use.EraseFromParentAsInstruction()
-			default:
-				// should not happen
-				panic("unknown return type of runtime.stringToBytes: " + use.Type().String())
-			}
-		}
-		if convertedAllUses {
-			// Call to runtime.stringToBytes can be eliminated: both the input
-			// and the output is constant.
-			call.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Basic escape analysis: translate runtime.alloc calls into alloca
-// instructions.
-func (c *Compiler) OptimizeAllocs() {
-	allocator := c.mod.NamedFunction("runtime.alloc")
-	if allocator.IsNil() {
-		// nothing to optimize
-		return
-	}
-
-	heapallocs := getUses(allocator)
-	for _, heapalloc := range heapallocs {
-		nilValue := llvm.Value{}
-		if heapalloc.Operand(0).IsAConstant() == nilValue {
-			// Do not allocate variable length arrays on the stack.
-			continue
-		}
-		size := heapalloc.Operand(0).ZExtValue()
-		if size > 256 {
-			// The maximum value for a stack allocation.
-			// TODO: tune this, this is just a random value.
-			continue
-		}
-
-		// In general the pattern is:
-		//     %0 = call i8* @runtime.alloc(i32 %size)
-		//     %1 = bitcast i8* %0 to type*
-		//     (use %1 only)
-		// But the bitcast might sometimes be dropped when allocating an *i8.
-		// The 'bitcast' variable below is thus usually a bitcast of the
-		// heapalloc but not always.
-		bitcast := heapalloc // instruction that creates the value
-		if uses := getUses(heapalloc); len(uses) == 1 && uses[0].IsABitCastInst() != nilValue {
-			// getting only bitcast use
-			bitcast = uses[0]
-		}
-		if !c.doesEscape(bitcast) {
-			// Insert alloca in the entry block. Do it here so that mem2reg can
-			// promote it to a SSA value.
-			fn := bitcast.InstructionParent().Parent()
-			c.builder.SetInsertPointBefore(fn.EntryBasicBlock().FirstInstruction())
-			alignment := c.targetData.ABITypeAlignment(c.i8ptrType)
-			sizeInWords := (size + uint64(alignment) - 1) / uint64(alignment)
-			allocaType := llvm.ArrayType(c.ctx.IntType(alignment*8), int(sizeInWords))
-			alloca := c.builder.CreateAlloca(allocaType, "stackalloc.alloca")
-			zero, _ := c.getZeroValue(alloca.Type().ElementType())
-			c.builder.CreateStore(zero, alloca)
-			stackalloc := c.builder.CreateBitCast(alloca, bitcast.Type(), "stackalloc")
-			bitcast.ReplaceAllUsesWith(stackalloc)
-			if heapalloc != bitcast {
-				bitcast.EraseFromParentAsInstruction()
-			}
-			heapalloc.EraseFromParentAsInstruction()
-		}
-	}
-}
-
-// Very basic escape analysis.
-func (c *Compiler) doesEscape(value llvm.Value) bool {
-	uses := getUses(value)
-	for _, use := range uses {
-		nilValue := llvm.Value{}
-		if use.IsAGetElementPtrInst() != nilValue {
-			if c.doesEscape(use) {
-				return true
-			}
-		} else if use.IsABitCastInst() != nilValue {
-			// A bitcast escapes if the casted-to value escapes.
-			if c.doesEscape(use) {
-				return true
-			}
-		} else if use.IsALoadInst() != nilValue {
-			// Load does not escape.
-		} else if use.IsAStoreInst() != nilValue {
-			// Store only escapes when the value is stored to, not when the
-			// value is stored into another value.
-			if use.Operand(0) == value {
-				return true
-			}
-		} else if use.IsACallInst() != nilValue {
-			// Call only escapes when the (pointer) parameter is not marked
-			// "nocapture". This flag means that the parameter does not escape
-			// the give function.
-			if use.CalledValue().IsAFunction() != nilValue {
-				if use.CalledValue().IsDeclaration() {
-					// Kind of dirty: assume external functions don't let
-					// pointers escape.
-					// TODO: introduce //go:noescape that sets the 'nocapture'
-					// flag on each input parameter.
-					continue
-				}
-			}
-			if !c.hasFlag(use, value, "nocapture") {
-				return true
-			}
-		} else {
-			// Unknown instruction, might escape.
-			return true
-		}
-	}
-
-	// does not escape
-	return false
-}
-
-// Check whether the given value (which is of pointer type) is never stored to.
-func (c *Compiler) isReadOnly(value llvm.Value) bool {
-	uses := getUses(value)
-	for _, use := range uses {
-		nilValue := llvm.Value{}
-		if use.IsAGetElementPtrInst() != nilValue {
-			if !c.isReadOnly(use) {
-				return false
-			}
-		} else if use.IsACallInst() != nilValue {
-			if !c.hasFlag(use, value, "readonly") {
-				return false
-			}
-		} else {
-			// Unknown instruction, might not be readonly.
-			return false
-		}
-	}
-	return true
-}
-
-// Check whether all uses of this param as parameter to the call have the given
-// flag. In most cases, there will only be one use but a function could take the
-// same parameter twice, in which case both must have the flag.
-// A flag can be any enum flag, like "readonly".
-func (c *Compiler) hasFlag(call, param llvm.Value, kind string) bool {
-	fn := call.CalledValue()
-	nilValue := llvm.Value{}
-	if fn.IsAFunction() == nilValue {
-		// This is not a function but something else, like a function pointer.
-		return false
-	}
-	kindID := llvm.AttributeKindID(kind)
-	for i := 0; i < fn.ParamsCount(); i++ {
-		if call.Operand(i) != param {
-			// This is not the parameter we're checking.
-			continue
-		}
-		index := i + 1 // param attributes start at 1
-		attr := fn.GetEnumAttributeAtIndex(index, kindID)
-		nilAttribute := llvm.Attribute{}
-		if attr == nilAttribute {
-			// At least one parameter doesn't have the flag (there may be
-			// multiple).
-			return false
-		}
-	}
-	return true
-}

compiler/reflect.go

@@ -1,156 +0,0 @@
-package compiler
-
-import (
-	"math/big"
-	"strings"
-)
-
-var basicTypes = map[string]int64{
-	"bool":       1,
-	"int":        2,
-	"int8":       3,
-	"int16":      4,
-	"int32":      5,
-	"int64":      6,
-	"uint":       7,
-	"uint8":      8,
-	"uint16":     9,
-	"uint32":     10,
-	"uint64":     11,
-	"uintptr":    12,
-	"float32":    13,
-	"float64":    14,
-	"complex64":  15,
-	"complex128": 16,
-	"string":     17,
-	"unsafeptr":  18,
-}
-
-func (c *Compiler) assignTypeCodes(typeSlice typeInfoSlice) {
-	fn := c.mod.NamedFunction("reflect.ValueOf")
-	if fn.IsNil() {
-		// reflect.ValueOf is never used, so we can use the most efficient
-		// encoding possible.
-		for i, t := range typeSlice {
-			t.num = uint64(i + 1)
-		}
-		return
-	}
-
-	// Assign typecodes the way the reflect package expects.
-	fallbackIndex := 1
-	namedTypes := make(map[string]int)
-	for _, t := range typeSlice {
-		if t.name[:5] != "type:" {
-			panic("expected type name to start with 'type:'")
-		}
-		num := c.getTypeCodeNum(t.name[5:], &fallbackIndex, namedTypes)
-		if num.BitLen() > c.uintptrType.IntTypeWidth() || !num.IsUint64() {
-			// TODO: support this in some way, using a side table for example.
-			// That's less efficient but better than not working at all.
-			// Particularly important on systems with 16-bit pointers (e.g.
-			// AVR).
-			panic("compiler: could not store type code number inside interface type code")
-		}
-		t.num = num.Uint64()
-	}
-}
-
-// getTypeCodeNum returns the typecode for a given type as expected by the
-// reflect package. Also see getTypeCodeName, which serializes types to a string
-// based on a types.Type value for this function.
-func (c *Compiler) getTypeCodeNum(id string, fallbackIndex *int, namedTypes map[string]int) *big.Int {
-	// Note: see src/reflect/type.go for bit allocations.
-	// A type can be named or unnamed. Example of both:
-	//     basic:~foo:uint64
-	//     basic:uint64
-	// Extract the class (basic, slice, pointer, etc.), the name, and the
-	// contents of this type ID string. Allocate bits based on that, as
-	// src/runtime/types.go expects.
-	class := id[:strings.IndexByte(id, ':')]
-	value := id[len(class)+1:]
-	name := ""
-	if value[0] == '~' {
-		name = value[1:strings.IndexByte(value, ':')]
-		value = value[len(name)+2:]
-	}
-	if class == "basic" {
-		// Basic types follow the following bit pattern:
-		//    ...xxxxx0
-		// where xxxxx is allocated for the 18 possible basic types and all the
-		// upper bits are used to indicate the named type.
-		num, ok := basicTypes[value]
-		if !ok {
-			panic("invalid basic type: " + id)
-		}
-		if name != "" {
-			// This type is named, set the upper bits to the name ID.
-			num |= int64(getNamedTypeNum(namedTypes, name)) << 5
-		}
-		return big.NewInt(num << 1)
-	} else {
-		// Complex types use the following bit pattern:
-		//    ...nxxx1
-		// where xxx indicates the complex type (any non-basic type). The upper
-		// bits contain whatever the type contains. Types that wrap a single
-		// other type (channel, interface, pointer, slice) just contain the bits
-		// of the wrapped type. Other types (like struct) have a different
-		// method of encoding the contents of the type.
-		var num *big.Int
-		var classNumber int64
-		switch class {
-		case "chan":
-			num = c.getTypeCodeNum(value, fallbackIndex, namedTypes)
-			classNumber = 0
-		case "interface":
-			num = big.NewInt(int64(*fallbackIndex))
-			*fallbackIndex++
-			classNumber = 1
-		case "pointer":
-			num = c.getTypeCodeNum(value, fallbackIndex, namedTypes)
-			classNumber = 2
-		case "slice":
-			num = c.getTypeCodeNum(value, fallbackIndex, namedTypes)
-			classNumber = 3
-		case "array":
-			num = big.NewInt(int64(*fallbackIndex))
-			*fallbackIndex++
-			classNumber = 4
-		case "func":
-			num = big.NewInt(int64(*fallbackIndex))
-			*fallbackIndex++
-			classNumber = 5
-		case "map":
-			num = big.NewInt(int64(*fallbackIndex))
-			*fallbackIndex++
-			classNumber = 6
-		case "struct":
-			num = big.NewInt(int64(*fallbackIndex))
-			*fallbackIndex++
-			classNumber = 7
-		default:
-			panic("unknown type kind: " + id)
-		}
-		if name == "" {
-			num.Lsh(num, 5).Or(num, big.NewInt((classNumber<<1)+1))
-		} else {
-			// TODO: store num in a sidetable
-			num = big.NewInt(int64(getNamedTypeNum(namedTypes, name))<<1 | 1)
-			num.Lsh(num, 4).Or(num, big.NewInt((classNumber<<1)+1))
-		}
-		return num
-	}
-}
-
-// getNamedTypeNum returns an appropriate (unique) number for the given named
-// type. If the name already has a number that number is returned, else a new
-// number is returned. The number is always non-zero.
-func getNamedTypeNum(namedTypes map[string]int, name string) int {
-	if num, ok := namedTypes[name]; ok {
-		return num
-	} else {
-		num = len(namedTypes) + 1
-		namedTypes[name] = num
-		return num
-	}
-}

compiler/sizes.go

@@ -107,6 +107,12 @@ func (s *StdSizes) Sizeof(T types.Type) int64 {
 		if k == types.Uintptr {
 			return s.PtrSize
 		}
+		if k == types.UnsafePointer {
+			return s.PtrSize
+		}
+		if k == types.Invalid {
+			return 0 // only relevant when there is a type error somewhere
+		}
 		panic("unknown basic type: " + t.String())
 	case *types.Array:
 		n := t.Len()
@@ -125,11 +131,21 @@ func (s *StdSizes) Sizeof(T types.Type) int64 {
 			return 0
 		}
 		fields := make([]*types.Var, t.NumFields())
+		maxAlign := int64(1)
 		for i := range fields {
-			fields[i] = t.Field(i)
+			field := t.Field(i)
+			fields[i] = field
+			al := s.Alignof(field.Type())
+			if al > maxAlign {
+				maxAlign = al
+			}
 		}
+		// Pick the size that fits this struct and add some alignment. Some
+		// structs have some extra padding at the end which should also be taken
+		// care of:
+		//     struct { int32 n; byte b }
 		offsets := s.Offsetsof(fields)
-		return offsets[n-1] + s.Sizeof(fields[n-1].Type())
+		return align(offsets[n-1]+s.Sizeof(fields[n-1].Type()), maxAlign)
 	case *types.Interface:
 		return s.PtrSize * 2
 	case *types.Pointer:

compiler/symbol.go

@@ -0,0 +1,147 @@
+package compiler
+
+// This file manages symbols, that is, functions and globals. It reads their
+// pragmas, determines the link name, etc.
+
+import (
+	"go/ast"
+	"go/token"
+	"go/types"
+	"strconv"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/loader"
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// globalInfo contains some information about a specific global. By default,
+// linkName is equal to .RelString(nil) on a global and extern is false, but for
+// some symbols this is different (due to //go:extern for example).
+type globalInfo struct {
+	linkName string // go:extern
+	extern   bool   // go:extern
+	align    int    // go:align
+}
+
+// loadASTComments loads comments on globals from the AST, for use later in the
+// program. In particular, they are required for //go:extern pragmas on globals.
+func (c *Compiler) loadASTComments(lprogram *loader.Program) {
+	c.astComments = map[string]*ast.CommentGroup{}
+	for _, pkgInfo := range lprogram.Sorted() {
+		for _, file := range pkgInfo.Files {
+			for _, decl := range file.Decls {
+				switch decl := decl.(type) {
+				case *ast.GenDecl:
+					switch decl.Tok {
+					case token.VAR:
+						if len(decl.Specs) != 1 {
+							continue
+						}
+						for _, spec := range decl.Specs {
+							switch spec := spec.(type) {
+							case *ast.ValueSpec: // decl.Tok == token.VAR
+								for _, name := range spec.Names {
+									id := pkgInfo.Pkg.Path() + "." + name.Name
+									c.astComments[id] = decl.Doc
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+// getGlobal returns a LLVM IR global value for a Go SSA global. It is added to
+// the LLVM IR if it has not been added already.
+func (c *Compiler) getGlobal(g *ssa.Global) llvm.Value {
+	info := c.getGlobalInfo(g)
+	llvmGlobal := c.mod.NamedGlobal(info.linkName)
+	if llvmGlobal.IsNil() {
+		typ := g.Type().(*types.Pointer).Elem()
+		llvmType := c.getLLVMType(typ)
+		llvmGlobal = llvm.AddGlobal(c.mod, llvmType, info.linkName)
+		if !info.extern {
+			llvmGlobal.SetInitializer(llvm.ConstNull(llvmType))
+			llvmGlobal.SetLinkage(llvm.InternalLinkage)
+		}
+
+		// Set alignment from the //go:align comment.
+		var alignInBits uint32
+		if info.align < 0 || info.align&(info.align-1) != 0 {
+			// Check for power-of-two (or 0).
+			// See: https://stackoverflow.com/a/108360
+			c.addError(g.Pos(), "global variable alignment must be a positive power of two")
+		} else {
+			// Set the alignment only when it is a power of two.
+			alignInBits = uint32(info.align) ^ uint32(info.align-1)
+			if info.align > c.targetData.ABITypeAlignment(llvmType) {
+				llvmGlobal.SetAlignment(info.align)
+			}
+		}
+
+		if c.Debug() && !info.extern {
+			// Add debug info.
+			// TODO: this should be done for every global in the program, not just
+			// the ones that are referenced from some code.
+			pos := c.ir.Program.Fset.Position(g.Pos())
+			diglobal := c.dibuilder.CreateGlobalVariableExpression(c.difiles[pos.Filename], llvm.DIGlobalVariableExpression{
+				Name:        g.RelString(nil),
+				LinkageName: info.linkName,
+				File:        c.getDIFile(pos.Filename),
+				Line:        pos.Line,
+				Type:        c.getDIType(typ),
+				LocalToUnit: false,
+				Expr:        c.dibuilder.CreateExpression(nil),
+				AlignInBits: alignInBits,
+			})
+			llvmGlobal.AddMetadata(0, diglobal)
+		}
+	}
+	return llvmGlobal
+}
+
+// getGlobalInfo returns some information about a specific global.
+func (c *Compiler) getGlobalInfo(g *ssa.Global) globalInfo {
+	info := globalInfo{}
+	if strings.HasPrefix(g.Name(), "C.") {
+		// Created by CGo: such a name cannot be created by regular C code.
+		info.linkName = g.Name()[2:]
+		info.extern = true
+	} else {
+		// Pick the default linkName.
+		info.linkName = g.RelString(nil)
+		// Check for //go: pragmas, which may change the link name (among
+		// others).
+		doc := c.astComments[info.linkName]
+		if doc != nil {
+			info.parsePragmas(doc)
+		}
+	}
+	return info
+}
+
+// Parse //go: pragma comments from the source. In particular, it parses the
+// //go:extern pragma on globals.
+func (info *globalInfo) parsePragmas(doc *ast.CommentGroup) {
+	for _, comment := range doc.List {
+		if !strings.HasPrefix(comment.Text, "//go:") {
+			continue
+		}
+		parts := strings.Fields(comment.Text)
+		switch parts[0] {
+		case "//go:extern":
+			info.extern = true
+			if len(parts) == 2 {
+				info.linkName = parts[1]
+			}
+		case "//go:align":
+			align, err := strconv.Atoi(parts[1])
+			if err == nil {
+				info.align = align
+			}
+		}
+	}
+}

compiler/syscall.go

@@ -4,7 +4,6 @@ package compiler
 // compiler builtins.
 
 import (
-	"go/constant"
 	"strconv"
 
 	"golang.org/x/tools/go/ssa"
@@ -14,14 +13,27 @@ import (
 // emitSyscall emits an inline system call instruction, depending on the target
 // OS/arch.
 func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value, error) {
-	num, _ := constant.Uint64Val(call.Args[0].(*ssa.Const).Value)
+	num := c.getValue(frame, call.Args[0])
 	var syscallResult llvm.Value
 	switch {
-	case c.GOARCH == "amd64" && c.GOOS == "linux":
+	case c.GOARCH() == "amd64":
+		if c.GOOS() == "darwin" {
+			// Darwin adds this magic number to system call numbers:
+			//
+			// > Syscall classes for 64-bit system call entry.
+			// > For 64-bit users, the 32-bit syscall number is partitioned
+			// > with the high-order bits representing the class and low-order
+			// > bits being the syscall number within that class.
+			// > The high-order 32-bits of the 64-bit syscall number are unused.
+			// > All system classes enter the kernel via the syscall instruction.
+			//
+			// Source: https://opensource.apple.com/source/xnu/xnu-792.13.8/osfmk/mach/i386/syscall_sw.h
+			num = c.builder.CreateOr(num, llvm.ConstInt(c.uintptrType, 0x2000000, false), "")
+		}
 		// Sources:
 		//   https://stackoverflow.com/a/2538212
 		//   https://en.wikibooks.org/wiki/X86_Assembly/Interfacing_with_Linux#syscall
-		args := []llvm.Value{llvm.ConstInt(c.uintptrType, num, false)}
+		args := []llvm.Value{num}
 		argTypes := []llvm.Type{c.uintptrType}
 		// Constraints will look something like:
 		//   "={rax},0,{rdi},{rsi},{rdx},{r10},{r8},{r9},~{rcx},~{r11}"
@@ -34,11 +46,11 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 				"{r10}",
 				"{r8}",
 				"{r9}",
+				"{r11}",
+				"{r12}",
+				"{r13}",
 			}[i]
-			llvmValue, err := c.parseExpr(frame, arg)
-			if err != nil {
-				return llvm.Value{}, err
-			}
+			llvmValue := c.getValue(frame, arg)
 			args = append(args, llvmValue)
 			argTypes = append(argTypes, llvmValue.Type())
 		}
@@ -46,7 +58,33 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 		fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
 		target := llvm.InlineAsm(fnType, "syscall", constraints, true, false, llvm.InlineAsmDialectIntel)
 		syscallResult = c.builder.CreateCall(target, args, "")
-	case c.GOARCH == "arm" && c.GOOS == "linux":
+	case c.GOARCH() == "386" && c.GOOS() == "linux":
+		// Sources:
+		//   syscall(2) man page
+		//   https://stackoverflow.com/a/2538212
+		//   https://en.wikibooks.org/wiki/X86_Assembly/Interfacing_with_Linux#int_0x80
+		args := []llvm.Value{num}
+		argTypes := []llvm.Type{c.uintptrType}
+		// Constraints will look something like:
+		//   "={eax},0,{ebx},{ecx},{edx},{esi},{edi},{ebp}"
+		constraints := "={eax},0"
+		for i, arg := range call.Args[1:] {
+			constraints += "," + [...]string{
+				"{ebx}",
+				"{ecx}",
+				"{edx}",
+				"{esi}",
+				"{edi}",
+				"{ebp}",
+			}[i]
+			llvmValue := c.getValue(frame, arg)
+			args = append(args, llvmValue)
+			argTypes = append(argTypes, llvmValue.Type())
+		}
+		fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
+		target := llvm.InlineAsm(fnType, "int 0x80", constraints, true, false, llvm.InlineAsmDialectIntel)
+		syscallResult = c.builder.CreateCall(target, args, "")
+	case c.GOARCH() == "arm" && c.GOOS() == "linux":
 		// Implement the EABI system call convention for Linux.
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}
@@ -64,14 +102,11 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 				"{r5}",
 				"{r6}",
 			}[i]
-			llvmValue, err := c.parseExpr(frame, arg)
-			if err != nil {
-				return llvm.Value{}, err
-			}
+			llvmValue := c.getValue(frame, arg)
 			args = append(args, llvmValue)
 			argTypes = append(argTypes, llvmValue.Type())
 		}
-		args = append(args, llvm.ConstInt(c.uintptrType, num, false))
+		args = append(args, num)
 		argTypes = append(argTypes, c.uintptrType)
 		constraints += ",{r7}" // syscall number
 		for i := len(call.Args) - 1; i < 4; i++ {
@@ -81,7 +116,7 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 		fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
 		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
 		syscallResult = c.builder.CreateCall(target, args, "")
-	case c.GOARCH == "arm64" && c.GOOS == "linux":
+	case c.GOARCH() == "arm64" && c.GOOS() == "linux":
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}
 		argTypes := []llvm.Type{}
@@ -97,14 +132,11 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 				"{x4}",
 				"{x5}",
 			}[i]
-			llvmValue, err := c.parseExpr(frame, arg)
-			if err != nil {
-				return llvm.Value{}, err
-			}
+			llvmValue := c.getValue(frame, arg)
 			args = append(args, llvmValue)
 			argTypes = append(argTypes, llvmValue.Type())
 		}
-		args = append(args, llvm.ConstInt(c.uintptrType, num, false))
+		args = append(args, num)
 		argTypes = append(argTypes, c.uintptrType)
 		constraints += ",{x8}" // syscall number
 		for i := len(call.Args) - 1; i < 8; i++ {
@@ -117,23 +149,44 @@ func (c *Compiler) emitSyscall(frame *Frame, call *ssa.CallCommon) (llvm.Value,
 		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
 		syscallResult = c.builder.CreateCall(target, args, "")
 	default:
-		return llvm.Value{}, c.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+c.GOOS+"/"+c.GOARCH)
+		return llvm.Value{}, c.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+c.GOOS()+"/"+c.GOARCH())
+	}
+	switch c.GOOS() {
+	case "linux", "freebsd":
+		// Return values: r0, r1 uintptr, err Errno
+		// Pseudocode:
+		//     var err uintptr
+		//     if syscallResult < 0 && syscallResult > -4096 {
+		//         err = -syscallResult
+		//     }
+		//     return syscallResult, 0, err
+		zero := llvm.ConstInt(c.uintptrType, 0, false)
+		inrange1 := c.builder.CreateICmp(llvm.IntSLT, syscallResult, llvm.ConstInt(c.uintptrType, 0, false), "")
+		inrange2 := c.builder.CreateICmp(llvm.IntSGT, syscallResult, llvm.ConstInt(c.uintptrType, 0xfffffffffffff000, true), "") // -4096
+		hasError := c.builder.CreateAnd(inrange1, inrange2, "")
+		errResult := c.builder.CreateSelect(hasError, c.builder.CreateSub(zero, syscallResult, ""), zero, "syscallError")
+		retval := llvm.Undef(c.ctx.StructType([]llvm.Type{c.uintptrType, c.uintptrType, c.uintptrType}, false))
+		retval = c.builder.CreateInsertValue(retval, syscallResult, 0, "")
+		retval = c.builder.CreateInsertValue(retval, zero, 1, "")
+		retval = c.builder.CreateInsertValue(retval, errResult, 2, "")
+		return retval, nil
+	case "darwin":
+		// Return values: r0, r1 uintptr, err Errno
+		// Pseudocode:
+		//     var err uintptr
+		//     if syscallResult != 0 {
+		//         err = syscallResult
+		//     }
+		//     return syscallResult, 0, err
+		zero := llvm.ConstInt(c.uintptrType, 0, false)
+		hasError := c.builder.CreateICmp(llvm.IntNE, syscallResult, llvm.ConstInt(c.uintptrType, 0, false), "")
+		errResult := c.builder.CreateSelect(hasError, syscallResult, zero, "syscallError")
+		retval := llvm.Undef(c.ctx.StructType([]llvm.Type{c.uintptrType, c.uintptrType, c.uintptrType}, false))
+		retval = c.builder.CreateInsertValue(retval, syscallResult, 0, "")
+		retval = c.builder.CreateInsertValue(retval, zero, 1, "")
+		retval = c.builder.CreateInsertValue(retval, errResult, 2, "")
+		return retval, nil
+	default:
+		return llvm.Value{}, c.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+c.GOOS()+"/"+c.GOARCH())
 	}
-	// Return values: r0, r1, err uintptr
-	// Pseudocode:
-	//     var err uintptr
-	//     if syscallResult < 0 && syscallResult > -4096 {
-	//         err = -syscallResult
-	//     }
-	//     return syscallResult, 0, err
-	zero := llvm.ConstInt(c.uintptrType, 0, false)
-	inrange1 := c.builder.CreateICmp(llvm.IntSLT, syscallResult, llvm.ConstInt(c.uintptrType, 0, false), "")
-	inrange2 := c.builder.CreateICmp(llvm.IntSGT, syscallResult, llvm.ConstInt(c.uintptrType, 0xfffffffffffff000, true), "") // -4096
-	hasError := c.builder.CreateAnd(inrange1, inrange2, "")
-	errResult := c.builder.CreateSelect(hasError, c.builder.CreateNot(syscallResult, ""), zero, "syscallError")
-	retval := llvm.Undef(llvm.StructType([]llvm.Type{c.uintptrType, c.uintptrType, c.uintptrType}, false))
-	retval = c.builder.CreateInsertValue(retval, syscallResult, 0, "")
-	retval = c.builder.CreateInsertValue(retval, zero, 1, "")
-	retval = c.builder.CreateInsertValue(retval, errResult, 2, "")
-	return retval, nil
 }

compiler/volatile.go

@@ -0,0 +1,26 @@
+package compiler
+
+// This file implements volatile loads/stores in runtime/volatile.LoadT and
+// runtime/volatile.StoreT as compiler builtins.
+
+import (
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+func (c *Compiler) emitVolatileLoad(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
+	addr := c.getValue(frame, instr.Args[0])
+	c.emitNilCheck(frame, addr, "deref")
+	val := c.builder.CreateLoad(addr, "")
+	val.SetVolatile(true)
+	return val, nil
+}
+
+func (c *Compiler) emitVolatileStore(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
+	addr := c.getValue(frame, instr.Args[0])
+	val := c.getValue(frame, instr.Args[1])
+	c.emitNilCheck(frame, addr, "deref")
+	store := c.builder.CreateStore(val, addr)
+	store.SetVolatile(true)
+	return llvm.Value{}, nil
+}

go.mod

@@ -0,0 +1,14 @@
+module github.com/tinygo-org/tinygo
+
+go 1.11
+
+require (
+	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
+	github.com/creack/goselect v0.1.0 // indirect
+	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
+	github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46
+	go.bug.st/serial.v1 v0.0.0-20180827123349-5f7892a7bb45
+	golang.org/x/sys v0.0.0-20191010194322-b09406accb47 // indirect
+	golang.org/x/tools v0.0.0-20190227180812-8dcc6e70cdef
+	tinygo.org/x/go-llvm v0.0.0-20200104190746-1ff21df33566
+)

go.sum

@@ -0,0 +1,36 @@
+github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
+github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
+github.com/creack/goselect v0.1.0 h1:4QiXIhcpSQF50XGaBsFzesjwX/1qOY5bOveQPmN9CXY=
+github.com/creack/goselect v0.1.0/go.mod h1:gHrIcH/9UZDn2qgeTUeW5K9eZsVYCH6/60J/FHysWyE=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf h1:7+FW5aGwISbqUtkfmIpZJGRgNFg2ioYPvFaUxdqpDsg=
+github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf/go.mod h1:RpwtwJQFrIEPstU94h88MWPXP2ektJZ8cZ0YntAmXiE=
+github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46 h1:wXG2bA8fO7Vv7lLk2PihFMTqmbT173Tje39oKzQ50Mo=
+github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
+go.bug.st/serial.v1 v0.0.0-20180827123349-5f7892a7bb45 h1:mACY1anK6HNCZtm/DK2Rf2ZPHggVqeB0+7rY9Gl6wyI=
+go.bug.st/serial.v1 v0.0.0-20180827123349-5f7892a7bb45/go.mod h1:dRSl/CVCTf56CkXgJMDOdSwNfo2g1orOGE/gBGdvjZw=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/ntt0swNk5oYBziWeTCvY=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190227180812-8dcc6e70cdef h1:ymc9FeDom3RIEA3coKokSllBB1hRcMT0tZ1W3Jf9Ids=
+golang.org/x/tools v0.0.0-20190227180812-8dcc6e70cdef/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
+google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+tinygo.org/x/go-llvm v0.0.0-20190224120431-7707ae5d1261 h1:rJS2Hga39YAnm7DE4qrPm6Dr/67EOojL0XPzvbEeBiw=
+tinygo.org/x/go-llvm v0.0.0-20190224120431-7707ae5d1261/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20190818154551-95bc4ffe1add h1:dFjMH1sLhYADg8UQm7DB56B7e+TfvAmWmEZLhyv3r/w=
+tinygo.org/x/go-llvm v0.0.0-20190818154551-95bc4ffe1add/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20191103182207-90b6e4bdc0b9 h1:d6rAX39a3C0pKrY5HcojEGyN8w9ocU0v7X28lC/TRKU=
+tinygo.org/x/go-llvm v0.0.0-20191103182207-90b6e4bdc0b9/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20191103200204-37e93e3f04e2 h1:Q5Hv3e5cLMGkiYwYgZL1Zrv6nb/EY+DJpRWrdO6ws6o=
+tinygo.org/x/go-llvm v0.0.0-20191103200204-37e93e3f04e2/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20191113125529-bad6d01809e8 h1:9Bfvso+tTVQg16UzOA614NaYA4x8vsRBNtd3eBrXwp0=
+tinygo.org/x/go-llvm v0.0.0-20191113125529-bad6d01809e8/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20191124211856-b2db3df3f257 h1:o8VDylrMN7gWemBMu8rEyuogKPhcLTdx5KrUAp9macc=
+tinygo.org/x/go-llvm v0.0.0-20191124211856-b2db3df3f257/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20191215173731-ad71f3d24aae h1:s8J5EyxCkHxXB08UI3gk9W9IS/ekizRvSX+PfZxnAB0=
+tinygo.org/x/go-llvm v0.0.0-20191215173731-ad71f3d24aae/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20200104190746-1ff21df33566 h1:a4y30bTf7U0zDA75v2PTL+XQ2OzJetj19gK8XwQpUNY=
+tinygo.org/x/go-llvm v0.0.0-20200104190746-1ff21df33566/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=

goenv/goenv.go

@@ -0,0 +1,197 @@
+// Package goenv returns environment variables that are used in various parts of
+// the compiler. You can query it manually with the `tinygo env` subcommand.
+package goenv
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"os/user"
+	"path/filepath"
+	"runtime"
+)
+
+// Keys is a slice of all available environment variable keys.
+var Keys = []string{
+	"GOOS",
+	"GOARCH",
+	"GOROOT",
+	"GOPATH",
+	"GOCACHE",
+	"CGO_ENABLED",
+	"TINYGOROOT",
+}
+
+// TINYGOROOT is the path to the final location for checking tinygo files. If
+// unset (by a -X ldflag), then sourceDir() will fallback to the original build
+// directory.
+var TINYGOROOT string
+
+// Get returns a single environment variable, possibly calculating it on-demand.
+// The empty string is returned for unknown environment variables.
+func Get(name string) string {
+	switch name {
+	case "GOOS":
+		if dir := os.Getenv("GOOS"); dir != "" {
+			return dir
+		}
+		return runtime.GOOS
+	case "GOARCH":
+		if dir := os.Getenv("GOARCH"); dir != "" {
+			return dir
+		}
+		return runtime.GOARCH
+	case "GOROOT":
+		return getGoroot()
+	case "GOPATH":
+		if dir := os.Getenv("GOPATH"); dir != "" {
+			return dir
+		}
+
+		// fallback
+		home := getHomeDir()
+		return filepath.Join(home, "go")
+	case "GOCACHE":
+		// Get the cache directory, usually ~/.cache/tinygo
+		dir, err := os.UserCacheDir()
+		if err != nil {
+			panic("could not find cache dir: " + err.Error())
+		}
+		return filepath.Join(dir, "tinygo")
+	case "CGO_ENABLED":
+		val := os.Getenv("CGO_ENABLED")
+		if val == "1" || val == "0" {
+			return val
+		}
+		// Default to enabling CGo.
+		return "1"
+	case "TINYGOROOT":
+		return sourceDir()
+	default:
+		return ""
+	}
+}
+
+// Return the TINYGOROOT, or exit with an error.
+func sourceDir() string {
+	// Use $TINYGOROOT as root, if available.
+	root := os.Getenv("TINYGOROOT")
+	if root != "" {
+		if !isSourceDir(root) {
+			fmt.Fprintln(os.Stderr, "error: $TINYGOROOT was not set to the correct root")
+			os.Exit(1)
+		}
+		return root
+	}
+
+	if TINYGOROOT != "" {
+		if !isSourceDir(TINYGOROOT) {
+			fmt.Fprintln(os.Stderr, "error: TINYGOROOT was not set to the correct root")
+			os.Exit(1)
+		}
+		return TINYGOROOT
+	}
+
+	// Find root from executable path.
+	path, err := os.Executable()
+	if err != nil {
+		// Very unlikely. Bail out if it happens.
+		panic("could not get executable path: " + err.Error())
+	}
+	root = filepath.Dir(filepath.Dir(path))
+	if isSourceDir(root) {
+		return root
+	}
+
+	// Fallback: use the original directory from where it was built
+	// https://stackoverflow.com/a/32163888/559350
+	_, path, _, _ = runtime.Caller(0)
+	root = filepath.Dir(filepath.Dir(path))
+	if isSourceDir(root) {
+		return root
+	}
+
+	fmt.Fprintln(os.Stderr, "error: could not autodetect root directory, set the TINYGOROOT environment variable to override")
+	os.Exit(1)
+	panic("unreachable")
+}
+
+// isSourceDir returns true if the directory looks like a TinyGo source directory.
+func isSourceDir(root string) bool {
+	_, err := os.Stat(filepath.Join(root, "src/runtime/internal/sys/zversion.go"))
+	if err != nil {
+		return false
+	}
+	_, err = os.Stat(filepath.Join(root, "src/device/arm/arm.go"))
+	return err == nil
+}
+
+func getHomeDir() string {
+	u, err := user.Current()
+	if err != nil {
+		panic("cannot get current user: " + err.Error())
+	}
+	if u.HomeDir == "" {
+		// This is very unlikely, so panic here.
+		// Not the nicest solution, however.
+		panic("could not find home directory")
+	}
+	return u.HomeDir
+}
+
+// getGoroot returns an appropriate GOROOT from various sources. If it can't be
+// found, it returns an empty string.
+func getGoroot() string {
+	goroot := os.Getenv("GOROOT")
+	if goroot != "" {
+		// An explicitly set GOROOT always has preference.
+		return goroot
+	}
+
+	// Check for the location of the 'go' binary and base GOROOT on that.
+	binpath, err := exec.LookPath("go")
+	if err == nil {
+		binpath, err = filepath.EvalSymlinks(binpath)
+		if err == nil {
+			goroot := filepath.Dir(filepath.Dir(binpath))
+			if isGoroot(goroot) {
+				return goroot
+			}
+		}
+	}
+
+	// Check what GOROOT was at compile time.
+	if isGoroot(runtime.GOROOT()) {
+		return runtime.GOROOT()
+	}
+
+	// Check for some standard locations, as a last resort.
+	var candidates []string
+	switch runtime.GOOS {
+	case "linux":
+		candidates = []string{
+			"/usr/local/go", // manually installed
+			"/usr/lib/go",   // from the distribution
+		}
+	case "darwin":
+		candidates = []string{
+			"/usr/local/go",             // manually installed
+			"/usr/local/opt/go/libexec", // from Homebrew
+		}
+	}
+
+	for _, candidate := range candidates {
+		if isGoroot(candidate) {
+			return candidate
+		}
+	}
+
+	// Can't find GOROOT...
+	return ""
+}
+
+// isGoroot checks whether the given path looks like a GOROOT.
+func isGoroot(goroot string) bool {
+	_, err := os.Stat(filepath.Join(goroot, "src", "runtime", "internal", "sys", "zversion.go"))
+	return err == nil
+}

interp/errors.go

@@ -3,15 +3,92 @@ package interp
 // This file provides useful types for errors encountered during IR evaluation.
 
 import (
+	"errors"
+	"go/scanner"
+	"go/token"
+	"path/filepath"
+
 	"tinygo.org/x/go-llvm"
 )
 
+// errUnreachable is returned when an unreachable instruction is executed. This
+// error should not be visible outside of the interp package.
+var errUnreachable = errors.New("interp: unreachable executed")
+
+// Unsupported is the specific error that is returned when an unsupported
+// instruction is hit while trying to interpret all initializers.
 type Unsupported struct {
-	Inst llvm.Value
+	ImportPath string
+	Inst       llvm.Value
+	Pos        token.Position
 }
 
 func (e Unsupported) Error() string {
 	// TODO: how to return the actual instruction string?
 	// It looks like LLVM provides no function for that...
-	return "interp: unsupported instruction"
+	return scanner.Error{
+		Pos: e.Pos,
+		Msg: "interp: unsupported instruction",
+	}.Error()
+}
+
+// unsupportedInstructionError returns a new "unsupported instruction" error for
+// the given instruction. It includes source location information, when
+// available.
+func (e *evalPackage) unsupportedInstructionError(inst llvm.Value) *Unsupported {
+	return &Unsupported{
+		ImportPath: e.packagePath,
+		Inst:       inst,
+		Pos:        getPosition(inst),
+	}
+}
+
+// Error encapsulates compile-time interpretation errors with an associated
+// import path. The errors may not have a precise location attached.
+type Error struct {
+	ImportPath string
+	Errs       []scanner.Error
+}
+
+// Error returns the string of the first error in the list of errors.
+func (e Error) Error() string {
+	return e.Errs[0].Error()
+}
+
+// errorAt returns an error value for the currently interpreted package at the
+// location of the instruction. The location information may not be complete as
+// it depends on debug information in the IR.
+func (e *evalPackage) errorAt(inst llvm.Value, msg string) Error {
+	return Error{
+		ImportPath: e.packagePath,
+		Errs:       []scanner.Error{errorAt(inst, msg)},
+	}
+}
+
+// errorAt returns an error value at the location of the instruction.
+// The location information may not be complete as it depends on debug
+// information in the IR.
+func errorAt(inst llvm.Value, msg string) scanner.Error {
+	return scanner.Error{
+		Pos: getPosition(inst),
+		Msg: msg,
+	}
+}
+
+// getPosition returns the position information for the given instruction, as
+// far as it is available.
+func getPosition(inst llvm.Value) token.Position {
+	if inst.IsAInstruction().IsNil() {
+		return token.Position{}
+	}
+	loc := inst.InstructionDebugLoc()
+	if loc.IsNil() {
+		return token.Position{}
+	}
+	file := loc.LocationScope().ScopeFile()
+	return token.Position{
+		Filename: filepath.Join(file.FileDirectory(), file.FileFilename()),
+		Line:     int(loc.LocationLine()),
+		Column:   int(loc.LocationColumn()),
+	}
 }

interp/frame.go

@@ -4,21 +4,17 @@ package interp
 // functions.
 
 import (
-	"errors"
 	"strings"
 
 	"tinygo.org/x/go-llvm"
 )
 
 type frame struct {
-	*Eval
-	fn      llvm.Value
-	pkgName string
-	locals  map[llvm.Value]Value
+	*evalPackage
+	fn     llvm.Value
+	locals map[llvm.Value]Value
 }
 
-var ErrUnreachable = errors.New("interp: unreachable executed")
-
 // evalBasicBlock evaluates a single basic block, returning the return value (if
 // ending with a ret instruction), a list of outgoing basic blocks (if not
 // ending with a ret instruction), or an error on failure.
@@ -79,26 +75,29 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateXor(lhs, rhs, "")}
 
 			default:
-				return nil, nil, &Unsupported{inst}
+				return nil, nil, fr.unsupportedInstructionError(inst)
 			}
 
 		// Memory operators
 		case !inst.IsAAllocaInst().IsNil():
-			fr.locals[inst] = &AllocaValue{
-				Underlying: getZeroValue(inst.Type().ElementType()),
-				Dirty:      false,
+			allocType := inst.Type().ElementType()
+			alloca := llvm.AddGlobal(fr.Mod, allocType, fr.packagePath+"$alloca")
+			alloca.SetInitializer(llvm.ConstNull(allocType))
+			alloca.SetLinkage(llvm.InternalLinkage)
+			fr.locals[inst] = &LocalValue{
+				Underlying: alloca,
 				Eval:       fr.Eval,
 			}
 		case !inst.IsALoadInst().IsNil():
-			operand := fr.getLocal(inst.Operand(0))
+			operand := fr.getLocal(inst.Operand(0)).(*LocalValue)
 			var value llvm.Value
-			if !operand.IsConstant() || inst.IsVolatile() {
+			if !operand.IsConstant() || inst.IsVolatile() || (!operand.Underlying.IsAConstantExpr().IsNil() && operand.Underlying.Opcode() == llvm.BitCast) {
 				value = fr.builder.CreateLoad(operand.Value(), inst.Name())
 			} else {
 				value = operand.Load()
 			}
 			if value.Type() != inst.Type() {
-				panic("interp: load: type does not match")
+				return nil, nil, fr.errorAt(inst, "interp: load: type does not match")
 			}
 			fr.locals[inst] = fr.getValue(value)
 		case !inst.IsAStoreInst().IsNil():
@@ -122,15 +121,16 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					// Not a constant operation.
 					// This should be detected by the scanner, but isn't at the
 					// moment.
-					panic("todo: non-const gep")
+					return nil, nil, fr.errorAt(inst, "todo: non-const gep")
 				}
 				indices[i] = uint32(operand.Value().ZExtValue())
 			}
-			result := value.GetElementPtr(indices)
+			result, err := value.GetElementPtr(indices)
+			if err != nil {
+				return nil, nil, fr.errorAt(inst, err.Error())
+			}
 			if result.Type() != inst.Type() {
-				println(" expected:", inst.Type().String())
-				println(" actual:  ", result.Type().String())
-				panic("interp: gep: type does not match")
+				return nil, nil, fr.errorAt(inst, "interp: gep: type does not match")
 			}
 			fr.locals[inst] = result
 
@@ -173,17 +173,55 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					continue // special case: bitcast of alloc
 				}
 			}
-			value := fr.getLocal(operand)
-			if bc, ok := value.(*PointerCastValue); ok {
-				value = bc.Underlying // avoid double bitcasts
+			if _, ok := fr.getLocal(operand).(*MapValue); ok {
+				// Special case for runtime.trackPointer calls.
+				// Note: this might not be entirely sound in some rare cases
+				// where the map is stored in a dirty global.
+				uses := getUses(inst)
+				if len(uses) == 1 {
+					use := uses[0]
+					if !use.IsACallInst().IsNil() && !use.CalledValue().IsAFunction().IsNil() && use.CalledValue().Name() == "runtime.trackPointer" {
+						continue
+					}
+				}
+				// It is not possible in Go to bitcast a map value to a pointer.
+				return nil, nil, fr.errorAt(inst, "unimplemented: bitcast of map")
 			}
-			fr.locals[inst] = &PointerCastValue{Eval: fr.Eval, Underlying: value, CastType: inst.Type()}
+			value := fr.getLocal(operand).(*LocalValue)
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateBitCast(value.Value(), inst.Type(), "")}
 
 		// Other operators
 		case !inst.IsAICmpInst().IsNil():
 			lhs := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
 			rhs := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
 			predicate := inst.IntPredicate()
+			if predicate == llvm.IntEQ {
+				var lhsZero, rhsZero bool
+				var ok1, ok2 bool
+				if lhs.Type().TypeKind() == llvm.PointerTypeKind {
+					// Unfortunately, the const propagation in the IR builder
+					// doesn't handle pointer compares of inttoptr values. So we
+					// implement it manually here.
+					lhsZero, ok1 = isPointerNil(lhs)
+					rhsZero, ok2 = isPointerNil(rhs)
+				}
+				if lhs.Type().TypeKind() == llvm.IntegerTypeKind {
+					lhsZero, ok1 = isZero(lhs)
+					rhsZero, ok2 = isZero(rhs)
+				}
+				if ok1 && ok2 {
+					if lhsZero && rhsZero {
+						// Both are zero, so this icmp is always evaluated to true.
+						fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int1Type(), 1, false)}
+						continue
+					}
+					if lhsZero != rhsZero {
+						// Only one of them is zero, so this comparison must return false.
+						fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int1Type(), 0, false)}
+						continue
+					}
+				}
+			}
 			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateICmp(predicate, lhs, rhs, "")}
 		case !inst.IsAFCmpInst().IsNil():
 			lhs := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
@@ -214,22 +252,26 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				if size != typeSize {
 					// allocate an array
 					if size%typeSize != 0 {
-						return nil, nil, &Unsupported{inst}
+						return nil, nil, fr.unsupportedInstructionError(inst)
 					}
 					elementCount = int(size / typeSize)
 					allocType = llvm.ArrayType(allocType, elementCount)
 				}
-				alloc := llvm.AddGlobal(fr.Mod, allocType, fr.pkgName+"$alloc")
-				alloc.SetInitializer(getZeroValue(allocType))
+				alloc := llvm.AddGlobal(fr.Mod, allocType, fr.packagePath+"$alloc")
+				alloc.SetInitializer(llvm.ConstNull(allocType))
 				alloc.SetLinkage(llvm.InternalLinkage)
-				result := &GlobalValue{
+				result := &LocalValue{
 					Underlying: alloc,
 					Eval:       fr.Eval,
 				}
 				if elementCount == 1 {
 					fr.locals[resultInst] = result
 				} else {
-					fr.locals[resultInst] = result.GetElementPtr([]uint32{0, 0})
+					result, err := result.GetElementPtr([]uint32{0, 0})
+					if err != nil {
+						return nil, nil, errorAt(inst, err.Error())
+					}
+					fr.locals[resultInst] = result
 				}
 			case callee.Name() == "runtime.hashmapMake":
 				// create a map
@@ -237,24 +279,55 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				valueSize := inst.Operand(1).ZExtValue()
 				fr.locals[inst] = &MapValue{
 					Eval:      fr.Eval,
-					PkgName:   fr.pkgName,
+					PkgName:   fr.packagePath,
 					KeySize:   int(keySize),
 					ValueSize: int(valueSize),
 				}
 			case callee.Name() == "runtime.hashmapStringSet":
 				// set a string key in the map
-				m := fr.getLocal(inst.Operand(0)).(*MapValue)
+				keyBuf := fr.getLocal(inst.Operand(1)).(*LocalValue)
+				keyLen := fr.getLocal(inst.Operand(2)).(*LocalValue)
+				valPtr := fr.getLocal(inst.Operand(3)).(*LocalValue)
+				m, ok := fr.getLocal(inst.Operand(0)).(*MapValue)
+				if !ok || !keyBuf.IsConstant() || !keyLen.IsConstant() || !valPtr.IsConstant() {
+					// The mapassign operation could not be done at compile
+					// time. Do it at runtime instead.
+					m := fr.getLocal(inst.Operand(0)).Value()
+					fr.markDirty(m)
+					llvmParams := []llvm.Value{
+						m,                                    // *runtime.hashmap
+						fr.getLocal(inst.Operand(1)).Value(), // key.ptr
+						fr.getLocal(inst.Operand(2)).Value(), // key.len
+						fr.getLocal(inst.Operand(3)).Value(), // value (unsafe.Pointer)
+						fr.getLocal(inst.Operand(4)).Value(), // context
+						fr.getLocal(inst.Operand(5)).Value(), // parentHandle
+					}
+					fr.builder.CreateCall(callee, llvmParams, "")
+					continue
+				}
 				// "key" is a Go string value, which in the TinyGo calling convention is split up
 				// into separate pointer and length parameters.
-				keyBuf := fr.getLocal(inst.Operand(1))
-				keyLen := fr.getLocal(inst.Operand(2))
-				valPtr := fr.getLocal(inst.Operand(3))
 				m.PutString(keyBuf, keyLen, valPtr)
 			case callee.Name() == "runtime.hashmapBinarySet":
 				// set a binary (int etc.) key in the map
-				m := fr.getLocal(inst.Operand(0)).(*MapValue)
-				keyBuf := fr.getLocal(inst.Operand(1))
-				valPtr := fr.getLocal(inst.Operand(2))
+				keyBuf := fr.getLocal(inst.Operand(1)).(*LocalValue)
+				valPtr := fr.getLocal(inst.Operand(2)).(*LocalValue)
+				m, ok := fr.getLocal(inst.Operand(0)).(*MapValue)
+				if !ok || !keyBuf.IsConstant() || !valPtr.IsConstant() {
+					// The mapassign operation could not be done at compile
+					// time. Do it at runtime instead.
+					m := fr.getLocal(inst.Operand(0)).Value()
+					fr.markDirty(m)
+					llvmParams := []llvm.Value{
+						m,                                    // *runtime.hashmap
+						fr.getLocal(inst.Operand(1)).Value(), // key
+						fr.getLocal(inst.Operand(2)).Value(), // value
+						fr.getLocal(inst.Operand(3)).Value(), // context
+						fr.getLocal(inst.Operand(4)).Value(), // parentHandle
+					}
+					fr.builder.CreateCall(callee, llvmParams, "")
+					continue
+				}
 				m.PutBinary(keyBuf, valPtr)
 			case callee.Name() == "runtime.stringConcat":
 				// adding two strings together
@@ -271,7 +344,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				}
 				globalType := llvm.ArrayType(fr.Mod.Context().Int8Type(), len(result))
 				globalValue := llvm.ConstArray(fr.Mod.Context().Int8Type(), vals)
-				global := llvm.AddGlobal(fr.Mod, globalType, fr.pkgName+"$stringconcat")
+				global := llvm.AddGlobal(fr.Mod, globalType, fr.packagePath+"$stringconcat")
 				global.SetInitializer(globalValue)
 				global.SetLinkage(llvm.InternalLinkage)
 				global.SetGlobalConstant(true)
@@ -279,10 +352,70 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				stringType := fr.Mod.GetTypeByName("runtime._string")
 				retPtr := llvm.ConstGEP(global, getLLVMIndices(fr.Mod.Context().Int32Type(), []uint32{0, 0}))
 				retLen := llvm.ConstInt(stringType.StructElementTypes()[1], uint64(len(result)), false)
-				ret := getZeroValue(stringType)
+				ret := llvm.ConstNull(stringType)
 				ret = llvm.ConstInsertValue(ret, retPtr, []uint32{0})
 				ret = llvm.ConstInsertValue(ret, retLen, []uint32{1})
 				fr.locals[inst] = &LocalValue{fr.Eval, ret}
+			case callee.Name() == "runtime.sliceCopy":
+				elementSize := fr.getLocal(inst.Operand(4)).(*LocalValue).Value().ZExtValue()
+				dstArray := fr.getLocal(inst.Operand(0)).(*LocalValue).stripPointerCasts()
+				srcArray := fr.getLocal(inst.Operand(1)).(*LocalValue).stripPointerCasts()
+				dstLen := fr.getLocal(inst.Operand(2)).(*LocalValue)
+				srcLen := fr.getLocal(inst.Operand(3)).(*LocalValue)
+				if elementSize != 1 && dstArray.Type().ElementType().TypeKind() == llvm.ArrayTypeKind && srcArray.Type().ElementType().TypeKind() == llvm.ArrayTypeKind {
+					// Slice data pointers are created by adding a global array
+					// and getting the address of the first element using a GEP.
+					// However, before the compiler can pass it to
+					// runtime.sliceCopy, it has to perform a bitcast to a *i8,
+					// to make it a unsafe.Pointer. Now, when the IR builder
+					// sees a bitcast of a GEP with zero indices, it will make
+					// a bitcast of the original array instead of the GEP,
+					// which breaks our assumptions.
+					// Re-add this GEP, in the hope that it it is then of the correct type...
+					dstArrayValue, err := dstArray.GetElementPtr([]uint32{0, 0})
+					if err != nil {
+						return nil, nil, errorAt(inst, err.Error())
+					}
+					dstArray = dstArrayValue.(*LocalValue)
+					srcArrayValue, err := srcArray.GetElementPtr([]uint32{0, 0})
+					if err != nil {
+						return nil, nil, errorAt(inst, err.Error())
+					}
+					srcArray = srcArrayValue.(*LocalValue)
+				}
+				if fr.Eval.TargetData.TypeAllocSize(dstArray.Type().ElementType()) != elementSize {
+					return nil, nil, fr.errorAt(inst, "interp: slice dst element size does not match pointer type")
+				}
+				if fr.Eval.TargetData.TypeAllocSize(srcArray.Type().ElementType()) != elementSize {
+					return nil, nil, fr.errorAt(inst, "interp: slice src element size does not match pointer type")
+				}
+				if dstArray.Type() != srcArray.Type() {
+					return nil, nil, fr.errorAt(inst, "interp: slice element types don't match")
+				}
+				length := dstLen.Value().SExtValue()
+				if srcLength := srcLen.Value().SExtValue(); srcLength < length {
+					length = srcLength
+				}
+				if length < 0 {
+					return nil, nil, fr.errorAt(inst, "interp: trying to copy a slice with negative length?")
+				}
+				for i := int64(0); i < length; i++ {
+					var err error
+					// *dst = *src
+					dstArray.Store(srcArray.Load())
+					// dst++
+					dstArrayValue, err := dstArray.GetElementPtr([]uint32{1})
+					if err != nil {
+						return nil, nil, errorAt(inst, err.Error())
+					}
+					dstArray = dstArrayValue.(*LocalValue)
+					// src++
+					srcArrayValue, err := srcArray.GetElementPtr([]uint32{1})
+					if err != nil {
+						return nil, nil, errorAt(inst, err.Error())
+					}
+					srcArray = srcArrayValue.(*LocalValue)
+				}
 			case callee.Name() == "runtime.stringToBytes":
 				// convert a string to a []byte
 				bufPtr := fr.getLocal(inst.Operand(0))
@@ -294,7 +427,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				}
 				globalType := llvm.ArrayType(fr.Mod.Context().Int8Type(), len(result))
 				globalValue := llvm.ConstArray(fr.Mod.Context().Int8Type(), vals)
-				global := llvm.AddGlobal(fr.Mod, globalType, fr.pkgName+"$bytes")
+				global := llvm.AddGlobal(fr.Mod, globalType, fr.packagePath+"$bytes")
 				global.SetInitializer(globalValue)
 				global.SetLinkage(llvm.InternalLinkage)
 				global.SetGlobalConstant(true)
@@ -302,14 +435,57 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				sliceType := inst.Type()
 				retPtr := llvm.ConstGEP(global, getLLVMIndices(fr.Mod.Context().Int32Type(), []uint32{0, 0}))
 				retLen := llvm.ConstInt(sliceType.StructElementTypes()[1], uint64(len(result)), false)
-				ret := getZeroValue(sliceType)
+				ret := llvm.ConstNull(sliceType)
 				ret = llvm.ConstInsertValue(ret, retPtr, []uint32{0}) // ptr
 				ret = llvm.ConstInsertValue(ret, retLen, []uint32{1}) // len
 				ret = llvm.ConstInsertValue(ret, retLen, []uint32{2}) // cap
 				fr.locals[inst] = &LocalValue{fr.Eval, ret}
-			case callee.Name() == "runtime.makeInterface":
-				uintptrType := callee.Type().Context().IntType(fr.TargetData.PointerSize() * 8)
-				fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstPtrToInt(inst.Operand(0), uintptrType)}
+			case callee.Name() == "runtime.interfaceImplements":
+				typecode := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
+				interfaceMethodSet := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
+				if typecode.IsAConstantExpr().IsNil() || typecode.Opcode() != llvm.PtrToInt {
+					return nil, nil, fr.errorAt(inst, "interp: expected typecode to be a ptrtoint")
+				}
+				typecode = typecode.Operand(0)
+				if interfaceMethodSet.IsAConstantExpr().IsNil() || interfaceMethodSet.Opcode() != llvm.GetElementPtr {
+					return nil, nil, fr.errorAt(inst, "interp: expected method set in runtime.interfaceImplements to be a constant gep")
+				}
+				interfaceMethodSet = interfaceMethodSet.Operand(0).Initializer()
+				methodSet := llvm.ConstExtractValue(typecode.Initializer(), []uint32{1})
+				if methodSet.IsAConstantExpr().IsNil() || methodSet.Opcode() != llvm.GetElementPtr {
+					return nil, nil, fr.errorAt(inst, "interp: expected method set to be a constant gep")
+				}
+				methodSet = methodSet.Operand(0).Initializer()
+
+				// Make a set of all the methods on the concrete type, for
+				// easier checking in the next step.
+				definedMethods := map[string]struct{}{}
+				for i := 0; i < methodSet.Type().ArrayLength(); i++ {
+					methodInfo := llvm.ConstExtractValue(methodSet, []uint32{uint32(i)})
+					name := llvm.ConstExtractValue(methodInfo, []uint32{0}).Name()
+					definedMethods[name] = struct{}{}
+				}
+				// Check whether all interface methods are also in the list
+				// of defined methods calculated above.
+				implements := uint64(1) // i1 true
+				for i := 0; i < interfaceMethodSet.Type().ArrayLength(); i++ {
+					name := llvm.ConstExtractValue(interfaceMethodSet, []uint32{uint32(i)}).Name()
+					if _, ok := definedMethods[name]; !ok {
+						// There is a method on the interface that is not
+						// implemented by the type.
+						implements = 0 // i1 false
+						break
+					}
+				}
+				fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int1Type(), implements, false)}
+			case callee.Name() == "runtime.nanotime":
+				fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int64Type(), 0, false)}
+			case callee.Name() == "llvm.dbg.value":
+				// do nothing
+			case strings.HasPrefix(callee.Name(), "llvm.lifetime."):
+				// do nothing
+			case callee.Name() == "runtime.trackPointer":
+				// do nothing
 			case strings.HasPrefix(callee.Name(), "runtime.print") || callee.Name() == "runtime._panic":
 				// This are all print instructions, which necessarily have side
 				// effects but no results.
@@ -349,7 +525,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					params = append(params, local)
 				}
 				var ret Value
-				scanResult := fr.Eval.hasSideEffects(callee)
+				scanResult, err := fr.hasSideEffects(callee)
+				if err != nil {
+					return nil, nil, err
+				}
 				if scanResult.severity == sideEffectLimited || dirtyParams && scanResult.severity != sideEffectAll {
 					// Side effect is bounded. This means the operation invokes
 					// side effects (like calling an external function) but it
@@ -372,7 +551,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					//     compile time.
 					//   * Unbounded: cannot call at runtime so we'll try to
 					//     interpret anyway and hope for the best.
-					ret, err = fr.function(callee, params, fr.pkgName, indent+"    ")
+					ret, err = fr.function(callee, params, indent+"    ")
 					if err != nil {
 						return nil, nil, err
 					}
@@ -382,7 +561,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				}
 			default:
 				// function pointers, etc.
-				return nil, nil, &Unsupported{inst}
+				return nil, nil, fr.unsupportedInstructionError(inst)
 			}
 		case !inst.IsAExtractValueInst().IsNil():
 			agg := fr.getLocal(inst.Operand(0)).(*LocalValue) // must be constant
@@ -392,7 +571,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				fr.locals[inst] = fr.getValue(newValue)
 			} else {
 				if len(indices) != 1 {
-					return nil, nil, errors.New("cannot handle extractvalue with not exactly 1 index")
+					return nil, nil, fr.errorAt(inst, "interp: cannot handle extractvalue with not exactly 1 index")
 				}
 				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateExtractValue(agg.Underlying, int(indices[0]), inst.Name())}
 			}
@@ -405,7 +584,7 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				fr.locals[inst] = &LocalValue{fr.Eval, newValue}
 			} else {
 				if len(indices) != 1 {
-					return nil, nil, errors.New("cannot handle insertvalue with not exactly 1 index")
+					return nil, nil, fr.errorAt(inst, "interp: cannot handle insertvalue with not exactly 1 index")
 				}
 				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateInsertValue(agg.Underlying, val.Value(), int(indices[0]), inst.Name())}
 			}
@@ -418,21 +597,25 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 			// conditional branch (if/then/else)
 			cond := fr.getLocal(inst.Operand(0)).Value()
 			if cond.Type() != fr.Mod.Context().Int1Type() {
-				panic("expected an i1 in a branch instruction")
+				return nil, nil, fr.errorAt(inst, "expected an i1 in a branch instruction")
 			}
 			thenBB := inst.Operand(1)
 			elseBB := inst.Operand(2)
-			if !cond.IsConstant() {
-				return nil, nil, errors.New("interp: branch on a non-constant")
-			} else {
-				switch cond.ZExtValue() {
-				case 0: // false
-					return nil, []llvm.Value{thenBB}, nil // then
-				case 1: // true
-					return nil, []llvm.Value{elseBB}, nil // else
-				default:
-					panic("branch was not true or false")
-				}
+			if !cond.IsAInstruction().IsNil() {
+				return nil, nil, fr.errorAt(inst, "interp: branch on a non-constant")
+			}
+			if !cond.IsAConstantExpr().IsNil() {
+				// This may happen when the instruction builder could not
+				// const-fold some instructions.
+				return nil, nil, fr.errorAt(inst, "interp: branch on a non-const-propagated constant expression")
+			}
+			switch cond {
+			case llvm.ConstInt(fr.Mod.Context().Int1Type(), 0, false): // false
+				return nil, []llvm.Value{thenBB}, nil // then
+			case llvm.ConstInt(fr.Mod.Context().Int1Type(), 1, false): // true
+				return nil, []llvm.Value{elseBB}, nil // else
+			default:
+				return nil, nil, fr.errorAt(inst, "branch was not true or false")
 			}
 		case !inst.IsABranchInst().IsNil() && inst.OperandsCount() == 1:
 			// unconditional branch (goto)
@@ -440,10 +623,11 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 		case !inst.IsAUnreachableInst().IsNil():
 			// Unreachable was reached (e.g. after a call to panic()).
 			// Report this as an error, as it is not supposed to happen.
-			return nil, nil, ErrUnreachable
+			// This is a sentinel error value.
+			return nil, nil, errUnreachable
 
 		default:
-			return nil, nil, &Unsupported{inst}
+			return nil, nil, fr.unsupportedInstructionError(inst)
 		}
 	}
 
@@ -457,6 +641,7 @@ func (fr *frame) getLocal(v llvm.Value) Value {
 	} else if value := fr.getValue(v); value != nil {
 		return value
 	} else {
+		// This should not happen under normal circumstances.
 		panic("cannot find value")
 	}
 }

interp/interp.go

@@ -7,7 +7,6 @@ package interp
 // methods.
 
 import (
-	"errors"
 	"strings"
 
 	"tinygo.org/x/go-llvm"
@@ -18,14 +17,21 @@ type Eval struct {
 	TargetData      llvm.TargetData
 	Debug           bool
 	builder         llvm.Builder
-	dibuilder       *llvm.DIBuilder
 	dirtyGlobals    map[llvm.Value]struct{}
 	sideEffectFuncs map[llvm.Value]*sideEffectResult // cache of side effect scan results
 }
 
+// evalPackage encapsulates the Eval type for just a single package. The Eval
+// type keeps state across the whole program, the evalPackage type keeps extra
+// state for the currently interpreted package.
+type evalPackage struct {
+	*Eval
+	packagePath string
+}
+
 // Run evaluates the function with the given name and then eliminates all
 // callers.
-func Run(mod llvm.Module, targetData llvm.TargetData, debug bool) error {
+func Run(mod llvm.Module, debug bool) error {
 	if debug {
 		println("\ncompile-time evaluation:")
 	}
@@ -33,24 +39,31 @@ func Run(mod llvm.Module, targetData llvm.TargetData, debug bool) error {
 	name := "runtime.initAll"
 	e := &Eval{
 		Mod:          mod,
-		TargetData:   targetData,
+		TargetData:   llvm.NewTargetData(mod.DataLayout()),
 		Debug:        debug,
 		dirtyGlobals: map[llvm.Value]struct{}{},
 	}
 	e.builder = mod.Context().NewBuilder()
-	e.dibuilder = llvm.NewDIBuilder(mod)
 
 	initAll := mod.NamedFunction(name)
 	bb := initAll.EntryBasicBlock()
-	e.builder.SetInsertPointBefore(bb.LastInstruction())
-	e.builder.SetInstDebugLocation(bb.FirstInstruction())
+	// Create a dummy alloca in the entry block that we can set the insert point
+	// to. This is necessary because otherwise we might be removing the
+	// instruction (init call) that we are removing after successful
+	// interpretation.
+	e.builder.SetInsertPointBefore(bb.FirstInstruction())
+	dummy := e.builder.CreateAlloca(e.Mod.Context().Int8Type(), "dummy")
+	e.builder.SetInsertPointBefore(dummy)
 	var initCalls []llvm.Value
 	for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+		if inst == dummy {
+			continue
+		}
 		if !inst.IsAReturnInst().IsNil() {
 			break // ret void
 		}
 		if inst.IsACallInst().IsNil() || inst.CalledValue().IsAFunction().IsNil() {
-			return errors.New("expected all instructions in " + name + " to be direct calls")
+			return errorAt(inst, "interp: expected all instructions in "+name+" to be direct calls")
 		}
 		initCalls = append(initCalls, inst)
 	}
@@ -60,13 +73,17 @@ func Run(mod llvm.Module, targetData llvm.TargetData, debug bool) error {
 	for _, call := range initCalls {
 		initName := call.CalledValue().Name()
 		if !strings.HasSuffix(initName, ".init") {
-			return errors.New("expected all instructions in " + name + " to be *.init() calls")
+			return errorAt(call, "interp: expected all instructions in "+name+" to be *.init() calls")
 		}
 		pkgName := initName[:len(initName)-5]
 		fn := call.CalledValue()
 		call.EraseFromParentAsInstruction()
-		_, err := e.Function(fn, []Value{&LocalValue{e, undefPtr}, &LocalValue{e, undefPtr}}, pkgName)
-		if err == ErrUnreachable {
+		evalPkg := evalPackage{
+			Eval:        e,
+			packagePath: pkgName,
+		}
+		_, err := evalPkg.function(fn, []Value{&LocalValue{e, undefPtr}, &LocalValue{e, undefPtr}}, "")
+		if err == errUnreachable {
 			break
 		}
 		if err != nil {
@@ -77,16 +94,14 @@ func Run(mod llvm.Module, targetData llvm.TargetData, debug bool) error {
 	return nil
 }
 
-func (e *Eval) Function(fn llvm.Value, params []Value, pkgName string) (Value, error) {
-	return e.function(fn, params, pkgName, "")
-}
-
-func (e *Eval) function(fn llvm.Value, params []Value, pkgName, indent string) (Value, error) {
+// function interprets the given function. The params are the function params
+// and the indent is the string indentation to use when dumping all interpreted
+// instructions.
+func (e *evalPackage) function(fn llvm.Value, params []Value, indent string) (Value, error) {
 	fr := frame{
-		Eval:    e,
-		fn:      fn,
-		pkgName: pkgName,
-		locals:  make(map[llvm.Value]Value),
+		evalPackage: e,
+		fn:          fn,
+		locals:      make(map[llvm.Value]Value),
 	}
 	for i, param := range fn.Params() {
 		fr.locals[param] = params[i]
@@ -115,11 +130,7 @@ func (e *Eval) function(fn llvm.Value, params []Value, pkgName, indent string) (
 // getValue determines what kind of LLVM value it gets and returns the
 // appropriate Value type.
 func (e *Eval) getValue(v llvm.Value) Value {
-	if !v.IsAGlobalVariable().IsNil() {
-		return &GlobalValue{e, v}
-	} else {
-		return &LocalValue{e, v}
-	}
+	return &LocalValue{e, v}
 }
 
 // markDirty marks the passed-in LLVM value dirty, recursively. For example,

interp/interp_test.go

@@ -0,0 +1,102 @@
+package interp
+
+import (
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+
+	"tinygo.org/x/go-llvm"
+)
+
+func TestInterp(t *testing.T) {
+	for _, name := range []string{
+		"basic",
+		"slice-copy",
+		"consteval",
+		"map",
+	} {
+		name := name // make tc local to this closure
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			runTest(t, "testdata/"+name)
+		})
+	}
+}
+
+func runTest(t *testing.T, pathPrefix string) {
+	// Read the input IR.
+	ctx := llvm.NewContext()
+	buf, err := llvm.NewMemoryBufferFromFile(pathPrefix + ".ll")
+	os.Stat(pathPrefix + ".ll") // make sure this file is tracked by `go test` caching
+	if err != nil {
+		t.Fatalf("could not read file %s: %v", pathPrefix+".ll", err)
+	}
+	mod, err := ctx.ParseIR(buf)
+	if err != nil {
+		t.Fatalf("could not load module:\n%v", err)
+	}
+
+	// Perform the transform.
+	err = Run(mod, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Run some cleanup passes to get easy-to-read outputs.
+	pm := llvm.NewPassManager()
+	defer pm.Dispose()
+	pm.AddGlobalOptimizerPass()
+	pm.AddDeadStoreEliminationPass()
+	pm.Run(mod)
+
+	// Read the expected output IR.
+	out, err := ioutil.ReadFile(pathPrefix + ".out.ll")
+	if err != nil {
+		t.Fatalf("could not read output file %s: %v", pathPrefix+".out.ll", err)
+	}
+
+	// See whether the transform output matches with the expected output IR.
+	expected := string(out)
+	actual := mod.String()
+	if !fuzzyEqualIR(expected, actual) {
+		t.Logf("output does not match expected output:\n%s", actual)
+		t.Fail()
+	}
+}
+
+// fuzzyEqualIR returns true if the two LLVM IR strings passed in are roughly
+// equal. That means, only relevant lines are compared (excluding comments
+// etc.).
+func fuzzyEqualIR(s1, s2 string) bool {
+	lines1 := filterIrrelevantIRLines(strings.Split(s1, "\n"))
+	lines2 := filterIrrelevantIRLines(strings.Split(s2, "\n"))
+	if len(lines1) != len(lines2) {
+		return false
+	}
+	for i, line := range lines1 {
+		if line != lines2[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// filterIrrelevantIRLines removes lines from the input slice of strings that
+// are not relevant in comparing IR. For example, empty lines and comments are
+// stripped out.
+func filterIrrelevantIRLines(lines []string) []string {
+	var out []string
+	for _, line := range lines {
+		line = strings.TrimSpace(line) // drop '\r' on Windows
+		if line == "" || line[0] == ';' {
+			continue
+		}
+		if strings.HasPrefix(line, "source_filename = ") {
+			continue
+		}
+		out = append(out, line)
+	}
+	return out
+}

interp/scan.go

@@ -1,11 +1,28 @@
 package interp
 
 import (
+	"strings"
+
 	"tinygo.org/x/go-llvm"
 )
 
 type sideEffectSeverity int
 
+func (severity sideEffectSeverity) String() string {
+	switch severity {
+	case sideEffectInProgress:
+		return "in progress"
+	case sideEffectNone:
+		return "none"
+	case sideEffectLimited:
+		return "limited"
+	case sideEffectAll:
+		return "all"
+	default:
+		return "unknown"
+	}
+}
+
 const (
 	sideEffectInProgress sideEffectSeverity = iota // computing side effects is in progress (for recursive functions)
 	sideEffectNone                                 // no side effects at all (pure)
@@ -23,19 +40,36 @@ type sideEffectResult struct {
 // hasSideEffects scans this function and all descendants, recursively. It
 // returns whether this function has side effects and if it does, which globals
 // it mentions anywhere in this function or any called functions.
-func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
-	switch fn.Name() {
-	case "runtime.alloc":
+func (e *evalPackage) hasSideEffects(fn llvm.Value) (*sideEffectResult, error) {
+	name := fn.Name()
+	switch {
+	case name == "runtime.alloc":
 		// Cannot be scanned but can be interpreted.
-		return &sideEffectResult{severity: sideEffectNone}
-	case "runtime._panic":
-		return &sideEffectResult{severity: sideEffectLimited}
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "runtime.nanotime":
+		// Fixed value at compile time.
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "runtime._panic":
+		return &sideEffectResult{severity: sideEffectLimited}, nil
+	case name == "runtime.interfaceImplements":
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "runtime.sliceCopy":
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "runtime.trackPointer":
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "llvm.dbg.value":
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	case strings.HasPrefix(name, "llvm.lifetime."):
+		return &sideEffectResult{severity: sideEffectNone}, nil
+	}
+	if fn.IsDeclaration() {
+		return &sideEffectResult{severity: sideEffectLimited}, nil
 	}
 	if e.sideEffectFuncs == nil {
 		e.sideEffectFuncs = make(map[llvm.Value]*sideEffectResult)
 	}
 	if se, ok := e.sideEffectFuncs[fn]; ok {
-		return se
+		return se, nil
 	}
 	result := &sideEffectResult{
 		severity:        sideEffectInProgress,
@@ -46,6 +80,7 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 	for bb := fn.EntryBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
 		for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
 			if inst.IsAInstruction().IsNil() {
+				// Should not happen in valid IR.
 				panic("not an instruction")
 			}
 
@@ -62,7 +97,7 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 			switch inst.InstructionOpcode() {
 			case llvm.IndirectBr, llvm.Invoke:
 				// Not emitted by the compiler.
-				panic("unknown instructions")
+				return nil, e.errorAt(inst, "unknown instructions")
 			case llvm.Call:
 				child := inst.CalledValue()
 				if !child.IsAInlineAsm().IsNil() {
@@ -81,11 +116,6 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 					continue
 				}
 				if child.IsDeclaration() {
-					switch child.Name() {
-					case "runtime.makeInterface":
-						// Can be interpreted so does not have side effects.
-						continue
-					}
 					// External function call. Assume only limited side effects
 					// (no affected globals, etc.).
 					if e.hasLocalSideEffects(dirtyLocals, inst) {
@@ -93,7 +123,10 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 					}
 					continue
 				}
-				childSideEffects := e.hasSideEffects(child)
+				childSideEffects, err := e.hasSideEffects(child)
+				if err != nil {
+					return nil, err
+				}
 				switch childSideEffects.severity {
 				case sideEffectInProgress, sideEffectNone:
 					// no side effects or recursive function - continue scanning
@@ -107,7 +140,16 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 				default:
 					panic("unreachable")
 				}
-			case llvm.Load, llvm.Store:
+			case llvm.Load:
+				if inst.IsVolatile() {
+					result.updateSeverity(sideEffectLimited)
+				}
+				if _, ok := e.dirtyGlobals[inst.Operand(0)]; ok {
+					if e.hasLocalSideEffects(dirtyLocals, inst) {
+						result.updateSeverity(sideEffectLimited)
+					}
+				}
+			case llvm.Store:
 				if inst.IsVolatile() {
 					result.updateSeverity(sideEffectLimited)
 				}
@@ -126,7 +168,7 @@ func (e *Eval) hasSideEffects(fn llvm.Value) *sideEffectResult {
 		// No side effect was reported for this function.
 		result.severity = sideEffectNone
 	}
-	return result
+	return result, nil
 }
 
 // hasLocalSideEffects checks whether the given instruction flows into a branch
@@ -141,6 +183,7 @@ func (e *Eval) hasLocalSideEffects(dirtyLocals map[llvm.Value]struct{}, inst llv
 	for use := inst.FirstUse(); !use.IsNil(); use = use.NextUse() {
 		user := use.User()
 		if user.IsAInstruction().IsNil() {
+			// Should not happen in valid IR.
 			panic("user not an instruction")
 		}
 		switch user.InstructionOpcode() {
@@ -160,10 +203,13 @@ func (e *Eval) hasLocalSideEffects(dirtyLocals map[llvm.Value]struct{}, inst llv
 				// Already handled in (*Eval).hasSideEffects.
 				continue
 			}
-			// But a store might also store to an alloca, in which case all uses
-			// of the alloca (possibly indirect through a GEP, bitcast, etc.)
-			// must be marked dirty.
-			panic("todo: store")
+			// This store might affect all kinds of values. While it is
+			// certainly possible to traverse through all of them, the easiest
+			// option right now is to just assume the worst and say that this
+			// function has side effects.
+			// TODO: traverse through all stores and mark all relevant allocas /
+			// globals dirty.
+			return true
 		default:
 			// All instructions that take 0 or more operands (1 or more if it
 			// was a use) and produce a result.

interp/scan_test.go

@@ -0,0 +1,93 @@
+package interp
+
+import (
+	"os"
+	"sort"
+	"testing"
+
+	"tinygo.org/x/go-llvm"
+)
+
+var scanTestTable = []struct {
+	name            string
+	severity        sideEffectSeverity
+	mentionsGlobals []string
+}{
+	{"returnsConst", sideEffectNone, nil},
+	{"returnsArg", sideEffectNone, nil},
+	{"externalCallOnly", sideEffectNone, nil},
+	{"externalCallAndReturn", sideEffectLimited, nil},
+	{"externalCallBranch", sideEffectLimited, nil},
+	{"readCleanGlobal", sideEffectNone, []string{"cleanGlobalInt"}},
+	{"readDirtyGlobal", sideEffectLimited, []string{"dirtyGlobalInt"}},
+	{"callFunctionPointer", sideEffectAll, []string{"functionPointer"}},
+	{"getDirtyPointer", sideEffectLimited, nil},
+	{"storeToPointer", sideEffectLimited, nil},
+}
+
+func TestScan(t *testing.T) {
+	t.Parallel()
+
+	// Read the input IR.
+	path := "testdata/scan.ll"
+	ctx := llvm.NewContext()
+	buf, err := llvm.NewMemoryBufferFromFile(path)
+	os.Stat(path) // make sure this file is tracked by `go test` caching
+	if err != nil {
+		t.Fatalf("could not read file %s: %v", path, err)
+	}
+	mod, err := ctx.ParseIR(buf)
+	if err != nil {
+		t.Fatalf("could not load module:\n%v", err)
+	}
+
+	// Check all to-be-tested functions.
+	for _, tc := range scanTestTable {
+		// Create an eval object, for testing.
+		e := &Eval{
+			Mod:          mod,
+			TargetData:   llvm.NewTargetData(mod.DataLayout()),
+			dirtyGlobals: map[llvm.Value]struct{}{},
+		}
+
+		// Mark some globals dirty, for testing.
+		e.markDirty(mod.NamedGlobal("dirtyGlobalInt"))
+
+		// Scan for side effects.
+		fn := mod.NamedFunction(tc.name)
+		if fn.IsNil() {
+			t.Errorf("scan test: could not find tested function %s in the IR", tc.name)
+			continue
+		}
+		evalPkg := &evalPackage{e, "testdata"}
+		result, err := evalPkg.hasSideEffects(fn)
+		if err != nil {
+			t.Errorf("scan test: failed to scan %s for side effects: %v", fn.Name(), err)
+		}
+
+		// Check whether the result is what we expect.
+		if result.severity != tc.severity {
+			t.Errorf("scan test: function %s should have severity %s but it has %s", tc.name, tc.severity, result.severity)
+		}
+
+		// Check whether the mentioned globals match with what we'd expect.
+		mentionsGlobalNames := make([]string, 0, len(result.mentionsGlobals))
+		for global := range result.mentionsGlobals {
+			mentionsGlobalNames = append(mentionsGlobalNames, global.Name())
+		}
+		sort.Strings(mentionsGlobalNames)
+		globalsMismatch := false
+		if len(result.mentionsGlobals) != len(tc.mentionsGlobals) {
+			globalsMismatch = true
+		} else {
+			for i, globalName := range mentionsGlobalNames {
+				if tc.mentionsGlobals[i] != globalName {
+					globalsMismatch = true
+				}
+			}
+		}
+		if globalsMismatch {
+			t.Errorf("scan test: expected %s to mention globals %v, but it mentions globals %v", tc.name, tc.mentionsGlobals, mentionsGlobalNames)
+		}
+	}
+}

interp/testdata/basic.ll

@@ -0,0 +1,60 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@main.v1 = internal global i64 0
+@main.nonConst1 = global [4 x i64] zeroinitializer
+@main.nonConst2 = global i64 0
+
+declare void @runtime.printint64(i64) unnamed_addr
+
+declare void @runtime.printnl() unnamed_addr
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @runtime.init()
+  call void @main.init()
+  ret void
+}
+
+define void @main() unnamed_addr {
+entry:
+  %0 = load i64, i64* @main.v1
+  call void @runtime.printint64(i64 %0)
+  call void @runtime.printnl()
+  ret void
+}
+
+define internal void @runtime.init() unnamed_addr {
+entry:
+  ret void
+}
+
+define internal void @main.init() unnamed_addr {
+entry:
+  store i64 3, i64* @main.v1
+  call void @"main.init#1"()
+
+  ; test the following pattern:
+  ;     func someValue() int // extern function
+  ;     var nonConst1 = [4]int{someValue(), 0, 0, 0}
+  %value1 = call i64 @someValue()
+  %gep1 = getelementptr [4 x i64], [4 x i64]* @main.nonConst1, i32 0, i32 0
+  store i64 %value1, i64* %gep1
+
+  ; Test that the global really is marked dirty:
+  ;     var nonConst2 = nonConst1[0]
+  %gep2 = getelementptr [4 x i64], [4 x i64]* @main.nonConst1, i32 0, i32 0
+  %value2 = load i64, i64* %gep2
+  store i64 %value2, i64* @main.nonConst2
+
+  ret void
+}
+
+define internal void @"main.init#1"() unnamed_addr {
+entry:
+  call void @runtime.printint64(i64 5)
+  call void @runtime.printnl()
+  ret void
+}
+
+declare i64 @someValue()

interp/testdata/basic.out.ll

@@ -0,0 +1,29 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@main.nonConst1 = local_unnamed_addr global [4 x i64] zeroinitializer
+@main.nonConst2 = local_unnamed_addr global i64 0
+
+declare void @runtime.printint64(i64) unnamed_addr
+
+declare void @runtime.printnl() unnamed_addr
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @runtime.printint64(i64 5)
+  call void @runtime.printnl()
+  %value1 = call i64 @someValue()
+  store i64 %value1, i64* getelementptr inbounds ([4 x i64], [4 x i64]* @main.nonConst1, i32 0, i32 0)
+  %value2 = load i64, i64* getelementptr inbounds ([4 x i64], [4 x i64]* @main.nonConst1, i32 0, i32 0)
+  store i64 %value2, i64* @main.nonConst2
+  ret void
+}
+
+define void @main() unnamed_addr {
+entry:
+  call void @runtime.printint64(i64 3)
+  call void @runtime.printnl()
+  ret void
+}
+
+declare i64 @someValue() local_unnamed_addr

interp/testdata/consteval.ll

@@ -0,0 +1,42 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@intToPtrResult = global i8 0
+@ptrToIntResult = global i8 0
+
+define void @runtime.initAll() {
+  call void @main.init()
+  ret void
+}
+
+define internal void @main.init() {
+  call void @testIntToPtr()
+  call void @testPtrToInt()
+  ret void
+}
+
+define internal void @testIntToPtr() {
+  %nil = icmp eq i8* inttoptr (i64 1024 to i8*), null
+  br i1 %nil, label %a, label %b
+a:
+  ; should not be reached
+  store i8 1, i8* @intToPtrResult
+  ret void
+b:
+  ; should be reached
+  store i8 2, i8* @intToPtrResult
+  ret void
+}
+
+define internal void @testPtrToInt() {
+  %zero = icmp eq i64 ptrtoint (i8* @ptrToIntResult to i64), 0
+  br i1 %zero, label %a, label %b
+a:
+  ; should not be reached
+  store i8 1, i8* @ptrToIntResult
+  ret void
+b:
+  ; should be reached
+  store i8 2, i8* @ptrToIntResult
+  ret void
+}

interp/testdata/consteval.out.ll

@@ -0,0 +1,9 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@intToPtrResult = local_unnamed_addr global i8 2
+@ptrToIntResult = local_unnamed_addr global i8 2
+
+define void @runtime.initAll() local_unnamed_addr {
+  ret void
+}

interp/testdata/map.ll

@@ -0,0 +1,76 @@
+target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv6m-none-eabi"
+
+%runtime._string = type { i8*, i32 }
+%runtime.hashmap = type { %runtime.hashmap*, i8*, i32, i8, i8, i8 }
+
+@main.m = global %runtime.hashmap* null
+@main.binaryMap = global %runtime.hashmap* null
+@main.stringMap = global %runtime.hashmap* null
+@main.init.string = internal unnamed_addr constant [7 x i8] c"CONNECT"
+
+declare %runtime.hashmap* @runtime.hashmapMake(i8, i8, i32, i8* %context, i8* %parentHandle)
+declare void @runtime.hashmapBinarySet(%runtime.hashmap*, i8*, i8*, i8* %context, i8* %parentHandle)
+declare void @runtime.hashmapStringSet(%runtime.hashmap*, i8*, i32, i8*, i8* %context, i8* %parentHandle)
+declare void @llvm.lifetime.end.p0i8(i64, i8*)
+declare void @llvm.lifetime.start.p0i8(i64, i8*)
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @main.init(i8* undef, i8* null)
+  ret void
+}
+
+define internal void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+entry:
+; Test that hashmap optimizations generally work (even with lifetimes).
+  %hashmap.key = alloca i8
+  %hashmap.value = alloca %runtime._string
+  %0 = call %runtime.hashmap* @runtime.hashmapMake(i8 1, i8 8, i32 1, i8* undef, i8* null)
+  %hashmap.value.bitcast = bitcast %runtime._string* %hashmap.value to i8*
+  call void @llvm.lifetime.start.p0i8(i64 8, i8* %hashmap.value.bitcast)
+  store %runtime._string { i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7 }, %runtime._string* %hashmap.value
+  call void @llvm.lifetime.start.p0i8(i64 1, i8* %hashmap.key)
+  store i8 1, i8* %hashmap.key
+  call void @runtime.hashmapBinarySet(%runtime.hashmap* %0, i8* %hashmap.key, i8* %hashmap.value.bitcast, i8* undef, i8* null)
+  call void @llvm.lifetime.end.p0i8(i64 1, i8* %hashmap.key)
+  call void @llvm.lifetime.end.p0i8(i64 8, i8* %hashmap.value.bitcast)
+  store %runtime.hashmap* %0, %runtime.hashmap** @main.m
+
+  ; Other tests, that can be done in a separate function.
+  call void @main.testNonConstantBinarySet()
+  call void @main.testNonConstantStringSet()
+  ret void
+}
+
+; Test that a map loaded from a global can still be used for mapassign
+; operations (with binary keys).
+define internal void @main.testNonConstantBinarySet() {
+  %hashmap.key = alloca i8
+  %hashmap.value = alloca i8
+  ; Create hashmap from global. This breaks the normal hashmapBinarySet
+  ; optimization, to test the fallback.
+  %map.new = call %runtime.hashmap* @runtime.hashmapMake(i8 1, i8 1, i32 1, i8* undef, i8* null)
+  store %runtime.hashmap* %map.new, %runtime.hashmap** @main.binaryMap
+  %map = load %runtime.hashmap*, %runtime.hashmap** @main.binaryMap
+  ; Do the binary set to the newly loaded map.
+  store i8 1, i8* %hashmap.key
+  store i8 2, i8* %hashmap.value
+  call void @runtime.hashmapBinarySet(%runtime.hashmap* %map, i8* %hashmap.key, i8* %hashmap.value, i8* undef, i8* null)
+  ret void
+}
+
+; Test that a map loaded from a global can still be used for mapassign
+; operations (with string keys).
+define internal void @main.testNonConstantStringSet() {
+  %hashmap.value = alloca i8
+  ; Create hashmap from global. This breaks the normal hashmapStringSet
+  ; optimization, to test the fallback.
+  %map.new = call %runtime.hashmap* @runtime.hashmapMake(i8 8, i8 1, i32 1, i8* undef, i8* null)
+  store %runtime.hashmap* %map.new, %runtime.hashmap** @main.stringMap
+  %map = load %runtime.hashmap*, %runtime.hashmap** @main.stringMap
+  ; Do the string set to the newly loaded map.
+  store i8 2, i8* %hashmap.value
+  call void @runtime.hashmapStringSet(%runtime.hashmap* %map, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7, i8* %hashmap.value, i8* undef, i8* null)
+  ret void
+}

interp/testdata/map.out.ll

@@ -0,0 +1,28 @@
+target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv6m-none-eabi"
+
+%runtime.hashmap = type { %runtime.hashmap*, i8*, i32, i8, i8, i8 }
+%runtime._string = type { i8*, i32 }
+
+@main.m = local_unnamed_addr global %runtime.hashmap* @"main$map"
+@main.binaryMap = local_unnamed_addr global %runtime.hashmap* @"main$map.4"
+@main.stringMap = local_unnamed_addr global %runtime.hashmap* @"main$map.6"
+@main.init.string = internal unnamed_addr constant [7 x i8] c"CONNECT"
+@"main$mapbucket" = internal unnamed_addr global { [8 x i8], i8*, [8 x i8], [8 x %runtime._string] } { [8 x i8] c"\04\00\00\00\00\00\00\00", i8* null, [8 x i8] c"\01\00\00\00\00\00\00\00", [8 x %runtime._string] [%runtime._string { i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7 }, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer, %runtime._string zeroinitializer] }
+@"main$map" = internal unnamed_addr global %runtime.hashmap { %runtime.hashmap* null, i8* getelementptr inbounds ({ [8 x i8], i8*, [8 x i8], [8 x %runtime._string] }, { [8 x i8], i8*, [8 x i8], [8 x %runtime._string] }* @"main$mapbucket", i32 0, i32 0, i32 0), i32 1, i8 1, i8 8, i8 0 }
+@"main$alloca.2" = internal global i8 1
+@"main$alloca.3" = internal global i8 2
+@"main$map.4" = internal unnamed_addr global %runtime.hashmap { %runtime.hashmap* null, i8* null, i32 0, i8 1, i8 1, i8 0 }
+@"main$alloca.5" = internal global i8 2
+@"main$map.6" = internal unnamed_addr global %runtime.hashmap { %runtime.hashmap* null, i8* null, i32 0, i8 8, i8 1, i8 0 }
+
+declare void @runtime.hashmapBinarySet(%runtime.hashmap*, i8*, i8*, i8*, i8*) local_unnamed_addr
+
+declare void @runtime.hashmapStringSet(%runtime.hashmap*, i8*, i32, i8*, i8*, i8*) local_unnamed_addr
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @runtime.hashmapBinarySet(%runtime.hashmap* @"main$map.4", i8* @"main$alloca.2", i8* @"main$alloca.3", i8* undef, i8* null)
+  call void @runtime.hashmapStringSet(%runtime.hashmap* @"main$map.6", i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7, i8* @"main$alloca.5", i8* undef, i8* null)
+  ret void
+}

interp/testdata/scan.ll

@@ -0,0 +1,61 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+define i64 @returnsConst() {
+  ret i64 0
+}
+
+define i64 @returnsArg(i64 %arg) {
+  ret i64 %arg
+}
+
+declare i64 @externalCall()
+
+define i64 @externalCallOnly() {
+  %result = call i64 @externalCall()
+  ret i64 0
+}
+
+define i64 @externalCallAndReturn() {
+  %result = call i64 @externalCall()
+  ret i64 %result
+}
+
+define i64 @externalCallBranch() {
+  %result = call i64 @externalCall()
+  %zero = icmp eq i64 %result, 0
+  br i1 %zero, label %if.then, label %if.done
+
+if.then:
+  ret i64 2
+
+if.done:
+  ret i64 4
+}
+
+@cleanGlobalInt = global i64 5
+define i64 @readCleanGlobal() {
+  %global = load i64, i64* @cleanGlobalInt
+  ret i64 %global
+}
+
+@dirtyGlobalInt = global i64 5
+define i64 @readDirtyGlobal() {
+  %global = load i64, i64* @dirtyGlobalInt
+  ret i64 %global
+}
+
+declare i64* @getDirtyPointer()
+
+define void @storeToPointer() {
+  %ptr = call i64* @getDirtyPointer()
+  store i64 3, i64* %ptr
+  ret void
+}
+
+@functionPointer = global i64()* null
+define i64 @callFunctionPointer() {
+  %fp = load i64()*, i64()** @functionPointer
+  %result = call i64 %fp()
+  ret i64 %result
+}

interp/testdata/slice-copy.ll

@@ -0,0 +1,86 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@main.uint8SliceSrc.buf = internal global [2 x i8] c"\03d"
+@main.uint8SliceSrc = internal unnamed_addr global { i8*, i64, i64 } { i8* getelementptr inbounds ([2 x i8], [2 x i8]* @main.uint8SliceSrc.buf, i32 0, i32 0), i64 2, i64 2 }
+@main.uint8SliceDst = internal unnamed_addr global { i8*, i64, i64 } zeroinitializer
+@main.int16SliceSrc.buf = internal global [3 x i16] [i16 5, i16 123, i16 1024]
+@main.int16SliceSrc = internal unnamed_addr global { i16*, i64, i64 } { i16* getelementptr inbounds ([3 x i16], [3 x i16]* @main.int16SliceSrc.buf, i32 0, i32 0), i64 3, i64 3 }
+@main.int16SliceDst = internal unnamed_addr global { i16*, i64, i64 } zeroinitializer
+
+declare i64 @runtime.sliceCopy(i8* %dst, i8* %src, i64 %dstLen, i64 %srcLen, i64 %elemSize) unnamed_addr
+
+declare i8* @runtime.alloc(i64) unnamed_addr
+
+declare void @runtime.printuint8(i8)
+
+declare void @runtime.printint16(i16)
+
+define void @runtime.initAll() unnamed_addr {
+entry:
+  call void @main.init()
+  ret void
+}
+
+define void @main() unnamed_addr {
+entry:
+  ; print(uintSliceSrc[0])
+  %uint8SliceSrc.buf = load i8*, i8** getelementptr inbounds ({ i8*, i64, i64 }, { i8*, i64, i64 }* @main.uint8SliceSrc, i64 0, i32 0)
+  %uint8SliceSrc.val = load i8, i8* %uint8SliceSrc.buf
+  call void @runtime.printuint8(i8 %uint8SliceSrc.val)
+
+  ; print(uintSliceDst[0])
+  %uint8SliceDst.buf = load i8*, i8** getelementptr inbounds ({ i8*, i64, i64 }, { i8*, i64, i64 }* @main.uint8SliceDst, i64 0, i32 0)
+  %uint8SliceDst.val = load i8, i8* %uint8SliceDst.buf
+  call void @runtime.printuint8(i8 %uint8SliceDst.val)
+
+  ; print(int16SliceSrc[0])
+  %int16SliceSrc.buf = load i16*, i16** getelementptr inbounds ({ i16*, i64, i64 }, { i16*, i64, i64 }* @main.int16SliceSrc, i64 0, i32 0)
+  %int16SliceSrc.val = load i16, i16* %int16SliceSrc.buf
+  call void @runtime.printint16(i16 %int16SliceSrc.val)
+
+  ; print(int16SliceDst[0])
+  %int16SliceDst.buf = load i16*, i16** getelementptr inbounds ({ i16*, i64, i64 }, { i16*, i64, i64 }* @main.int16SliceDst, i64 0, i32 0)
+  %int16SliceDst.val = load i16, i16* %int16SliceDst.buf
+  call void @runtime.printint16(i16 %int16SliceDst.val)
+  ret void
+}
+
+define internal void @main.init() unnamed_addr {
+entry:
+  ; equivalent of:
+  ;     uint8SliceDst = make([]uint8, len(uint8SliceSrc))
+  %uint8SliceSrc = load { i8*, i64, i64 }, { i8*, i64, i64 }* @main.uint8SliceSrc
+  %uint8SliceSrc.len = extractvalue { i8*, i64, i64 } %uint8SliceSrc, 1
+  %uint8SliceDst.buf = call i8* @runtime.alloc(i64 %uint8SliceSrc.len)
+  %0 = insertvalue { i8*, i64, i64 } undef, i8* %uint8SliceDst.buf, 0
+  %1 = insertvalue { i8*, i64, i64 } %0, i64 %uint8SliceSrc.len, 1
+  %2 = insertvalue { i8*, i64, i64 } %1, i64 %uint8SliceSrc.len, 2
+  store { i8*, i64, i64 } %2, { i8*, i64, i64 }* @main.uint8SliceDst
+
+  ; equivalent of:
+  ;     copy(uint8SliceDst, uint8SliceSrc)
+  %uint8SliceSrc.buf = extractvalue { i8*, i64, i64 } %uint8SliceSrc, 0
+  %copy.n = call i64 @runtime.sliceCopy(i8* %uint8SliceDst.buf, i8* %uint8SliceSrc.buf, i64 %uint8SliceSrc.len, i64 %uint8SliceSrc.len, i64 1)
+
+  ; equivalent of:
+  ;     int16SliceDst = make([]int16, len(int16SliceSrc))
+  %int16SliceSrc = load { i16*, i64, i64 }, { i16*, i64, i64 }* @main.int16SliceSrc
+  %int16SliceSrc.len = extractvalue { i16*, i64, i64 } %int16SliceSrc, 1
+  %int16SliceSrc.len.bytes = mul i64 %int16SliceSrc.len, 2
+  %int16SliceDst.buf.raw = call i8* @runtime.alloc(i64 %int16SliceSrc.len.bytes)
+  %int16SliceDst.buf = bitcast i8* %int16SliceDst.buf.raw to i16*
+  %3 = insertvalue { i16*, i64, i64 } undef, i16* %int16SliceDst.buf, 0
+  %4 = insertvalue { i16*, i64, i64 } %3, i64 %int16SliceSrc.len, 1
+  %5 = insertvalue { i16*, i64, i64 } %4, i64 %int16SliceSrc.len, 2
+  store { i16*, i64, i64 } %5, { i16*, i64, i64 }* @main.int16SliceDst
+
+  ; equivalent of:
+  ;     copy(int16SliceDst, int16SliceSrc)
+  %int16SliceSrc.buf = extractvalue { i16*, i64, i64 } %int16SliceSrc, 0
+  %int16SliceSrc.buf.i8ptr = bitcast i16* %int16SliceSrc.buf to i8*
+  %int16SliceDst.buf.i8ptr = bitcast i16* %int16SliceDst.buf to i8*
+  %copy.n2 = call i64 @runtime.sliceCopy(i8* %int16SliceDst.buf.i8ptr, i8* %int16SliceSrc.buf.i8ptr, i64 %int16SliceSrc.len, i64 %int16SliceSrc.len, i64 2)
+
+  ret void
+}