main: add -json flag support to go env

This is needed for VS Code support.
loader: load packages using Go modules
2026-07-27 07:08:42 +00:00 · 2020-05-08 14:50:37 +02:00 · 2020-05-08 14:50:26 +02:00 · 2020-05-08 14:50:26 +02:00 · 2020-05-05 00:06:53 +02:00 · 2020-05-04 21:58:27 +02:00
707 changed files with 9955 additions and 44236 deletions
@@ -28,7 +28,6 @@ commands:
                qemu-user \
                gcc-avr \
                avr-libc
-            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-8-dev
  install-node:
    steps:
      - run:
@@ -38,57 +37,28 @@ commands:
            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
-  install-chrome:
-    steps:
-      - run:
-          name: "Install Chrome"
-          command: |
-            wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
-            sudo apt install ./google-chrome-stable_current_amd64.deb
-  install-wasmtime:
-    steps:
-      - run:
-          name: "Install wasmtime"
-          command: |
-            curl https://wasmtime.dev/install.sh -sSf | bash
-            sudo ln -s ~/.wasmtime/bin/wasmtime /usr/local/bin/wasmtime
-  install-xtensa-toolchain:
-    parameters:
-      variant:
-        type: string
-    steps:
-      - run:
-          name: "Install Xtensa toolchain"
-          command: |
-            curl -L https://github.com/espressif/crosstool-NG/releases/download/esp-2020r2/xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz -o xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
-            sudo tar -C /usr/local -xf xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
-            sudo ln -s /usr/local/xtensa-esp32-elf/bin/xtensa-esp32-elf-ld /usr/local/bin/xtensa-esp32-elf-ld
-            rm xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
  llvm-source-linux:
    steps:
      - restore_cache:
          keys:
-            - llvm-source-11-v2
+            - llvm-source-10-v0
      - run:
          name: "Fetch LLVM source"
          command: make llvm-source
      - save_cache:
-          key: llvm-source-11-v2
+          key: llvm-source-10-v0
          paths:
-            - llvm-project/clang/lib/Headers
-            - llvm-project/clang/include
-            - llvm-project/lld/include
-            - llvm-project/llvm/include
+            - llvm-project
  build-wasi-libc:
    steps:
      - restore_cache:
          keys:
-            - wasi-libc-sysroot-v4
+            - wasi-libc-sysroot-v2
      - run:
          name: "Build wasi-libc"
          command: make wasi-libc
      - save_cache:
-          key: wasi-libc-sysroot-v4
+          key: wasi-libc-sysroot-v2
          paths:
            - lib/wasi-libc/sysroot
  test-linux:
@@ -101,8 +71,6 @@ commands:
      - apt-dependencies:
          llvm: "<<parameters.llvm>>"
      - install-node
-      - install-chrome
-      - install-wasmtime
      - restore_cache:
          keys:
            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -111,21 +79,20 @@ commands:
      - run: go install -tags=llvm<<parameters.llvm>> .
      - restore_cache:
          keys:
-            - wasi-libc-sysroot-systemclang-v3
+            - wasi-libc-sysroot-systemclang-v1
      - run: make wasi-libc
      - save_cache:
-          key: wasi-libc-sysroot-systemclang-v3
+          key: wasi-libc-sysroot-systemclang-v1
          paths:
            - lib/wasi-libc/sysroot
-      - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./compiler ./interp ./transform .
+      - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./interp ./transform .
      - run: make gen-device -j4
-      - run: make smoketest XTENSA=0
-      - run: make tinygo-test
-      - run: make wasmtest
+      - 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:
@@ -135,9 +102,9 @@ commands:
      - run:
          name: "Install apt dependencies"
          command: |
-            sudo apt-get update
            sudo apt-get install \
                gcc-arm-linux-gnueabihf \
+                binutils-arm-none-eabi \
                libc6-dev-armel-cross \
                gcc-aarch64-linux-gnu \
                libc6-dev-arm64-cross \
@@ -145,11 +112,7 @@ commands:
                qemu-user \
                gcc-avr \
                avr-libc
-            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
      - install-node
-      - install-wasmtime
-      - install-xtensa-toolchain:
-          variant: "linux-amd64"
      - restore_cache:
          keys:
            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -157,26 +120,25 @@ commands:
      - llvm-source-linux
      - restore_cache:
          keys:
-            - llvm-build-11-linux-v3-assert
+            - llvm-build-10-linux-v0-assert
      - run:
          name: "Build LLVM"
          command: |
            if [ ! -f llvm-build/lib/liblldELF.a ]
            then
-              # fetch LLVM source
-              rm -rf llvm-project
-              make llvm-source
              # install dependencies
-              sudo apt-get install cmake ninja-build
+              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
-              find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
            fi
      - save_cache:
-          key: llvm-build-11-linux-v3-assert
+          key: llvm-build-10-linux-v0-assert
          paths:
            llvm-build
      - run: make ASSERT=1
@@ -184,15 +146,11 @@ commands:
      - run:
          name: "Test TinyGo"
          command: make ASSERT=1 test
-          environment:
-            # Note: -p=2 limits parallelism to two jobs at a time, which is
-            # necessary to keep memory consumption down and avoid OOM (for a
-            # 2CPU/4GB executor).
-            GOFLAGS: -p=2
      - 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
@@ -203,9 +161,9 @@ commands:
      - run:
          name: "Install apt dependencies"
          command: |
-            sudo apt-get update
            sudo apt-get install \
                gcc-arm-linux-gnueabihf \
+                binutils-arm-none-eabi \
                libc6-dev-armel-cross \
                gcc-aarch64-linux-gnu \
                libc6-dev-arm64-cross \
@@ -213,11 +171,7 @@ commands:
                qemu-user \
                gcc-avr \
                avr-libc
-            sudo apt-get install --no-install-recommends libc6-dev-i386 lib32gcc-6-dev
      - install-node
-      - install-wasmtime
-      - install-xtensa-toolchain:
-          variant: "linux-amd64"
      - restore_cache:
          keys:
            - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -225,51 +179,43 @@ commands:
      - llvm-source-linux
      - restore_cache:
          keys:
-            - llvm-build-11-linux-v3-noassert
+            - llvm-build-10-linux-v0
      - run:
          name: "Build LLVM"
          command: |
            if [ ! -f llvm-build/lib/liblldELF.a ]
            then
-              # fetch LLVM source
-              rm -rf llvm-project
-              make llvm-source
              # install dependencies
-              sudo apt-get install cmake ninja-build
+              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
-              find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
            fi
      - save_cache:
-          key: llvm-build-11-linux-v3-noassert
+          key: llvm-build-10-linux-v0
          paths:
            llvm-build
      - build-wasi-libc
      - run:
          name: "Test TinyGo"
          command: make test
-      - run:
-          name: "Install fpm"
-          command: |
-            sudo apt-get install ruby ruby-dev
-            sudo gem install --no-document fpm
      - run:
          name: "Build TinyGo release"
          command: |
-            make release deb -j3
+            make release -j3
            cp -p build/release.tar.gz /tmp/tinygo.linux-amd64.tar.gz
-            cp -p build/release.deb    /tmp/tinygo_amd64.deb
      - store_artifacts:
          path: /tmp/tinygo.linux-amd64.tar.gz
-      - store_artifacts:
-          path: /tmp/tinygo_amd64.deb
      - 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"
@@ -286,58 +232,49 @@ commands:
      - run:
          name: "Install dependencies"
          command: |
-            curl https://dl.google.com/go/go1.16.darwin-amd64.tar.gz -o go1.16.darwin-amd64.tar.gz
-            sudo tar -C /usr/local -xzf go1.16.darwin-amd64.tar.gz
+            curl https://dl.google.com/go/go1.14.darwin-amd64.tar.gz -o go1.14.darwin-amd64.tar.gz
+            sudo tar -C /usr/local -xzf go1.14.darwin-amd64.tar.gz
            ln -s /usr/local/go/bin/go /usr/local/bin/go
            HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
-      - install-xtensa-toolchain:
-          variant: "macos"
      - restore_cache:
          keys:
-            - go-cache-macos-v3-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
-            - go-cache-macos-v3-{{ checksum "go.mod" }}
+            - go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
+            - go-cache-macos-v2-{{ checksum "go.mod" }}
      - restore_cache:
          keys:
-            - llvm-source-11-macos-v3
+            - llvm-source-10-macos-v0
      - run:
          name: "Fetch LLVM source"
          command: make llvm-source
      - save_cache:
-          key: llvm-source-11-macos-v3
+          key: llvm-source-10-macos-v0
          paths:
-            - llvm-project/clang/lib/Headers
-            - llvm-project/clang/include
-            - llvm-project/lld/include
-            - llvm-project/llvm/include
+            - llvm-project
      - restore_cache:
          keys:
-            - llvm-build-11-macos-v4
+            - llvm-build-10-macos-v0
      - run:
          name: "Build LLVM"
          command: |
            if [ ! -f llvm-build/lib/liblldELF.a ]
            then
-              # fetch LLVM source
-              rm -rf llvm-project
-              make llvm-source
              # install dependencies
              HOMEBREW_NO_AUTO_UPDATE=1 brew install cmake ninja
              # build!
              make llvm-build
-              find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
            fi
      - save_cache:
-          key: llvm-build-11-macos-v4
+          key: llvm-build-10-macos-v0
          paths:
            llvm-build
      - restore_cache:
          keys:
-            - wasi-libc-sysroot-macos-v4
+            - wasi-libc-sysroot-macos-v1
      - run:
          name: "Build wasi-libc"
          command: make wasi-libc
      - save_cache:
-          key: wasi-libc-sysroot-macos-v4
+          key: wasi-libc-sysroot-macos-v1
          paths:
            - lib/wasi-libc/sysroot
      - run:
@@ -357,14 +294,33 @@ commands:
            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-v3-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
+          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-buster
+    steps:
+      - test-linux:
+          llvm: "9"
+  test-llvm10-go112:
+    docker:
+      - image: circleci/golang:1.12-buster
+    steps:
+      - test-linux:
+          llvm: "10"
  test-llvm10-go113:
    docker:
      - image: circleci/golang:1.13-buster
@@ -377,18 +333,6 @@ jobs:
    steps:
      - test-linux:
          llvm: "10"
-  test-llvm11-go115:
-    docker:
-      - image: circleci/golang:1.15-buster
-    steps:
-      - test-linux:
-          llvm: "11"
-  test-llvm11-go116:
-    docker:
-      - image: circleci/golang:1.16-buster
-    steps:
-      - test-linux:
-          llvm: "11"
  assert-test-linux:
    docker:
      - image: circleci/golang:1.14-stretch
@@ -401,19 +345,20 @@ jobs:
      - build-linux
  build-macos:
    macos:
-      xcode: "11.1.0" # macOS 10.14
+      xcode: "10.1.0"
    steps:
      - build-macos



+
 workflows:
  test-all:
    jobs:
+      - test-llvm9-go111
+      - test-llvm10-go112
      - test-llvm10-go113
      - test-llvm10-go114
-      - test-llvm11-go115
-      - test-llvm11-go116
      - build-linux
      - build-macos
      - assert-test-linux
@@ -3,26 +3,14 @@ docs/_build
 src/device/avr/*.go
 src/device/avr/*.ld
 src/device/avr/*.s
-src/device/esp/*.go
 src/device/nrf/*.go
 src/device/nrf/*.s
-src/device/nxp/*.go
-src/device/nxp/*.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
-src/device/kendryte/*.go
-src/device/kendryte/*.s
 vendor
 llvm-build
 llvm-project
-
-# Ignore files generated by smoketest
-test.gba
-test.hex
-test.nro
-test.wasm
-wasm.wasm
@@ -9,7 +9,7 @@
 	url = https://github.com/avr-rust/avr-mcu.git
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
-	url = https://github.com/tinygo-org/cmsis-svd
+	url = https://github.com/posborne/cmsis-svd
 [submodule "lib/compiler-rt"]
 	path = lib/compiler-rt
 	url = https://github.com/llvm-mirror/compiler-rt.git
@@ -20,6 +20,3 @@
 [submodule "lib/picolibc"]
 	path = lib/picolibc
 	url = https://github.com/keith-packard/picolibc.git
-[submodule "lib/stm32-svd"]
-	path = lib/stm32-svd
-	url = https://github.com/tinygo-org/stm32-svd
@@ -10,20 +10,12 @@ 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
 build a release tarball that includes this binary and all necessary extra files.

-**Note**: this documentation describes how to build a statically linked release
-tarball. If you want to develop TinyGo, you will probably want to follow a
-different guide:
-
-  * [Linux](https://tinygo.org/getting-started/linux/#source-install)
-  * [macOS](https://tinygo.org/getting-started/macos/#source-install)
-  * [Windows](https://tinygo.org/getting-started/windows/#source-install)
-
 ## Dependencies

 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 (1.13+)
+  * Go (1.11+)
  * Standard build tools (gcc/clang)
  * git
  * CMake
@@ -43,6 +35,11 @@ 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

 Before starting the build, you may want to set the following environment
@@ -87,10 +84,6 @@ Now that we have a working static build, it's time to make a release tarball:

    make release

-If you did not clone the repository with the `--recursive` option, you will get errors until you initialize the project submodules:
-
-    git submodule update --init
-
 The release tarball is stored in build/release.tar.gz, and can be extracted with
 the following command (for example in ~/lib):

@@ -1,438 +1,3 @@
-0.18.0
---
-
-* **command line**
-  - drop support for Go 1.11 and 1.12
-  - throw an error when no target is specified on Windows
-  - improve error messages in `getDefaultPort()`, support for multiple ports
-  - remove `-cflags` and `-ldflags` flags
-  - implement `-ldflags="-X ..."`
-  - add `-print-allocs` flag that lets you print all heap allocations
-  - openocd commands in tinygo command line
-  - add `-llvm-features` parameter
-  - match `go test` output
-  - discover USB ports only, this will ignore f.ex. bluetooth
-  - use physicmal path instead of cached GOROOT in function getGoroot
-  - add goroot for snap installs
-* **compiler**
-  - `builder`: add support for `-opt=0`
-  - `builder`, `compiler`: compile and cache packages in parallel
-  - `builder`: run interp per package
-  - `builder`: cache C and assembly file outputs
-  - `builder`: add support for `-x` flag to print commands
-  - `builder`: add optsize attribute while building the package
-  - `builder`: run function passes per package
-  - `builder`: hard code Clang compiler
-  - `compiler`: do not use `llvm.GlobalContext()`
-  - `compiler`: remove SimpleDCE pass
-  - `compiler`: do not emit nil checks for `*ssa.Alloc` instructions
-  - `compiler`: merge `runtime.typecodeID` and runtime.typeInInterface
-  - `compiler`: do not check for impossible type asserts
-  - `compiler`: fix use of global context: `llvm.Int32Type()`
-  - `compiler`: add interface IR test
-  - `compiler`: fix lack of method name in interface matching
-  - `compiler`: fix "fragment covers entire variable" bug
-  - `compiler`: optimize string literals and globals
-  - `compiler`: decouple func lowering from interface type codes
-  - `compiler`: add function attributes to some runtime calls
-  - `compiler`: improve position information in error messages
-  - `cgo`: add support for CFLAGS in .c files
-  - `interp`: support GEP on fixed (MMIO) addresses
-  - `interp`: handle `(reflect.Type).Elem()`
-  - `interp`: add support for runtime.interfaceMethod
-  - `interp`: make toLLVMValue return an error instead of panicking
-  - `interp`: add support for switch statement
-  - `interp`: fix phi instruction
-  - `interp`: remove map support
-  - `interp`: support extractvalue/insertvalue with multiple operands
-  - `transform`: optimize string comparisons against ""
-  - `transform`: optimize `reflect.Type` `Implements()` method
-  - `transform`: fix bug in interface lowering when signatures are renamed
-  - `transform`: don't rely on struct name of `runtime.typecodeID`
-  - `transform`: use IPSCCP pass instead of the constant propagation pass
-  - `transform`: fix func lowering assertion failure
-  - `transform`: do not lower zero-sized alloc to alloca
-  - `transform`: split interface and reflect lowering
-* **standard library**
-  - `runtime`: add dummy debug package
-  - `machine`: fix data shift/mask in newUSBSetup
-  - `machine`: make `machine.I2C0` and similar objects pointers
-  - `machine`: unify usbcdc code
-  - `machine`: refactor PWM support
-  - `machine`: avoid heap allocations in USB code
-  - `reflect`: let `reflect.Type` be of interface type
-  - `reflect`: implement a number of stub functions
-  - `reflect`: check for access in the `Interface` method call
-  - `reflect`: fix `AssignableTo` and `Implements` methods
-  - `reflect`: implement `Value.CanAddr`
-  - `reflect`: implement `Sizeof` and `Alignof` for func values
-  - `reflect`: implement `New` function
-  - `runtime`: implement command line arguments in hosted environments
-  - `runtime`: implement environment variables for Linux
-  - `runtime`: improve timers on nrf, and samd chips
-* **targets**
-  - all: use -Qunused-arguments only for assembly files
-  - `atmega1280`: add PWM support
-  - `attiny`: remove dummy UART
-  - `atsamd21`: improve SPI
-  - `atsamd51`: fix PWM support in atsamd51p20
-  - `atsamd5x`: improve SPI
-  - `atsamd51`, `atsame5x`: unify samd51 and same5x
-  - `atsamd51`, `atsamd21`: fix `ADC.Get()` value at 8bit and 10bit
-  - `atsame5x`: add support for CAN
-  - `avr`: remove I2C stubs from attiny support
-  - `cortexm`: check for `arm-none-eabi-gdb` and `gdb-multiarch` commands
-  - `cortexm`: add `__isr_vector` symbol
-  - `cortexm`: disable FPU on Cortex-M4
-  - `cortexm`: clean up Cortex-M target files
-  - `fe310`: fix SPI read
-  - `gameboy-advance`: Fix RGBA color interpretation
-  - `nrf52833`: add PWM support
-  - `stm32l0`: use unified UART logic
-  - `stm32`: move f103 (bluepill) to common i2c code
-  - `stm32`: separate altfunc selection for UART Tx/Rx
-  - `stm32`: i2c implementation for F7, L5 and L4 MCUs
-  - `stm32`: make SPI CLK fast to fix data issue
-  - `stm32`: support SPI on L4 series
-  - `unix`: avoid possible heap allocation with `-opt=0`
-  - `unix`: use conservative GC by default
-  - `unix`: use the tasks scheduler instead of coroutines
-  - `wasi`: upgrade WASI version to wasi_snapshot_preview1
-  - `wasi`: darwin: support basic file io based on libc
-  - `wasm`: only export explicitly exported functions
-  - `wasm`: use WASI ABI for exit function
-  - `wasm`: scan globals conservatively
-* **boards**
-  - `arduino-mega1280`: add support for the Arduino Mega 1280
-  - `arduino-nano-new`: Add Arduino Nano w/ New Bootloader target
-  - `atsame54-xpro`: add initial support this board
-  - `feather-m4-can`: add initial support for this board
-  - `grandcentral-m4`: add board support for Adafruit Grand Central M4 (SAMD51)
-  - `lgt92`: update to new UART structure
-  - `microbit`: remove LED constant
-  - `microbit-v2`: add support for S113 SoftDevice
-  - `nucleol432`: add support for this board
-  - `nucleo-l031k6`: add this board
-  - `pca10059`: initial support for this board
-  - `qtpy`: fix msd-volume-name
-  - `qtpy`: fix i2c setting
-  - `teensy40`: move txBuffer allocation to UART declaration
-  - `teensy40`: add UART0 as alias for UART1
-
-
-0.17.0
-
---
-* **command line**
-  - switch to LLVM 11 for static builds
-  - support gdb debugging with AVR
-  - add support for additional openocd commands
-  - add `-x` flag to print commands
-  - use LLVM 11 by default when linking LLVM dynamically
-  - update go-llvm to use LLVM 11 on macOS
-  - bump go.bug.st/serial to version 1.1.2
-  - do not build LLVM with libxml to work around a bugo on macOS
-  - add support for Go 1.16
-  - support gdb daemonization on Windows
-  - remove support for LLVM 9, to fix CI
-  - kill OpenOCD if it does not exit with a regular quit signal
-  - support `-ocd-output` on Windows
-* **compiler**
-  - `builder`: parallelize most of the build
-  - `builder`: remove unused cacheKey parameter
-  - `builder`: add -mcpu flag while building libraries
-  - `builder`: wait for running jobs to finish
-  - `cgo`: add support for variadic functions
-  - `compiler`: fix undefined behavior in wordpack
-  - `compiler`: fix incorrect "exported function" panic
-  - `compiler`: fix non-int integer constants (fixing a crash)
-  - `compiler`: refactor and add tests
-  - `compiler`: emit a nil check when slicing an array pointer
-  - `compiler`: saturate float-to-int conversions
-  - `compiler`: test float to int conversions and fix upper-bound calculation
-  - `compiler`: support all kinds of deferred builtins
-  - `compiler`: remove ir package
-  - `compiler`: remove unnecessary main.main call workaround
-  - `compiler`: move the setting of attributes to getFunction
-  - `compiler`: create runtime types lazily when needed
-  - `compiler`: move settings to a separate Config struct
-  - `compiler`: work around an ARM backend bug in LLVM
-  - `interp`: rewrite entire package
-  - `interp`: fix alignment of untyped globals
-  - `loader`: use name "main" for the main package
-  - `loader`: support imports from vendor directories
-  - `stacksize`: add support for DW_CFA_offset_extended
-  - `transform`: show better error message in coroutines lowering
-* **standard library**
-  - `machine`: accept configuration struct for ADC parameters
-  - `machine`: make I2C.Configure signature consistent
-  - `reflect`: implement PtrTo
-  - `runtime`: refactor to simplify stack switching
-  - `runtime`: put metadata at the top end of the heap
-* **targets**
-  - `atsam`: add a length check to findPinPadMapping
-  - `atsam`: improve USBCDC
-  - `atsam`: avoid infinite loop when USBCDC is disconnected
-  - `avr`: add SPI support for Atmega based chips
-  - `avr`: use Clang for compiling C and assembly files
-  - `esp32`: implement task based scheduler
-  - `esp32`: enable the FPU
-  - `esp8266`: implement task based scheduler
-  - `esp`: add compiler-rt library
-  - `esp`: add picolibc
-  - `nrf`: refactor code a bit to reduce duplication
-  - `nrf`: use SPIM peripheral instead of the legacy SPI peripheral
-  - `nrf`: update nrfx submodule to latest commit
-  - `nrf52840`: ensure that USB CDC interface is only initialized once
-  - `nrf52840`: improve USBCDC
-  - `stm32`: use stm32-rs SVDs which are of much higher quality
-  - `stm32`: harmonization of UART logic
-  - `stm32`: replace I2C addressable interface with simpler type
-  - `stm32`: fix i2c and add stm32f407 i2c
-  - `stm32`: revert change that adds support for channels in interrupts
-  - `wasm`: implement a growable heap
-  - `wasm`: fix typo in wasm_exec.js, syscall/js.valueLoadString()
-  - `wasm`: Namespaced Wasm Imports so they don't conflict across modules, or reserved LLVM IR
-  - `wasi`: support env variables based on libc
-  - `wasi`: specify wasi-libc in a different way, to improve error message
-* **boards**
-  - `matrixportal-m4`: add support for board Adafruit Matrix Portal M4
-  - `mkr1000`: add this board
-  - `nucleo-f722ze`: add this board
-  - `clue`: correct volume name and add alias for release version of Adafruit Clue board
-  - `p1am-100`: add support for the P1AM-100 (similar to Arduino MKR)
-  - `microbit-v2`: add initial support based on work done by @alankrantas thank you!
-  - `lgt92`: support for STM32L0 MCUs and Dragino LGT92 device
-  - `nicenano`: nice!nano board support
-  - `circuitplay-bluefruit`: correct internal I2C pin mapping
-  - `clue`: correct for lack of low frequency crystal
-  - `digispark`: split off attiny85 target
-  - `nucleo-l552ze`: implementation with CLOCK, LED, and UART
-  - `nrf52840-mdk-usb-dongle`: add this board
-
-0.16.0
---
-
-* **command-line**
-  - add initial support for LLVM 11
-  - make lib64 clang include path check more robust
-  - `build`: improve support for GOARCH=386 and add tests
-  - `gdb`: add support for qemu-user targets
-  - `test`: support non-host tests
-  - `test`: add support for -c and -o flags
-  - `test`: implement some benchmark stubs
-* **compiler**
-  - `builder`: improve detection of clang on Fedora
-  - `compiler`: fix floating point comparison bugs
-  - `compiler`: implement negate for complex numbers
-  - `loader`: fix linkname in test binaries
-  - `transform`: add missing return pointer restore for regular coroutine tail
-    calls
-* **standard library**
-  - `machine`: switch default frequency to 4MHz
-  - `machine`: clarify caller's responsibility in `SetInterrupt`
-  - `os`: add `LookupEnv()` stub
-  - `reflect`: implement `Swapper`
-  - `runtime`: fix UTF-8 decoding
-  - `runtime`: gc: use raw stack access whenever possible
-  - `runtime`: use dedicated printfloat32
-  - `runtime`: allow ranging over a nil map
-  - `runtime`: avoid device/nxp dependency in HardFault handler
-  - `testing`: implement dummy Helper method
-  - `testing`: add Run method
-* **targets**
-  - `arm64`: add support for SVCall intrinsic
-  - `atsamd51`: avoid panic when configuring SPI with SDI=NoPin
-  - `avr`: properly support the `.rodata` section
-  - `esp8266`: implement `Pin.Get` function
-  - `nintendoswitch`: fix crash when printing long lines (> 120)
-  - `nintendoswitch`: add env parser and removed unused stuff
-  - `nrf`: add I2C error checking
-  - `nrf`: give more flexibility in picking SPI speeds
-  - `nrf`: fix nrf52832 flash size
-  - `stm32f103`: support wakeups from interrupts
-  - `stm32f405`: add SPI support
-  - `stm32f405`: add I2C support
-  - `wasi`: add support for this target
-  - `wasi`: use 'generic' ABI by default
-  - `wasi`: remove --no-threads flag from wasm-ld
-  - `wasm`: add instanceof support for WebAssembly
-  - `wasm`: use fixed length buffer for putchar
-* **boards**
-  - `d1mini`: add this ESP8266 based board
-  - `esp32`: use board definitions instead of chip names
-  - `qtpy`: add board definition for Adafruit QTPy
-  - `teensy40`: add this board
-
-0.15.0
---
-
-* **command-line**
-  - add cached GOROOT to info subcommand
-  - embed git-hash in tinygo-dev executable
-  - implement tinygo targets to list usable targets
-  - use simpler file copy instead of file renaming to avoid issues on nrf52840 UF2 bootloaders
-  - use ToSlash() to specify program path
-  - support flashing esp32/esp8266 directly from tinygo
-  - when flashing call PortReset only on other than openocd
-* **compiler**
-  - `compileopts`: add support for custom binary formats
-  - `compiler`: improve display of goroutine wrappers
-  - `interp`: don't panic in the Store method
-  - `interp`: replace some panics with error messages
-  - `interp`: show error line in first line of the traceback
-  - `loader`: be more robust when creating the cached GOROOT
-  - `loader`: rewrite/refactor much of the code to use go list directly
-  - `loader`: use ioutil.TempDir to create a temporary directory
-  - `stacksize`: deal with DW_CFA_advance_loc1
-* **standard library**
-  - `runtime`: use waitForEvents when appropriate
-* **wasm**
-  - `wasm`: Remove --no-threads from wasm-ld calls.
-  - `wasm`: update wasi-libc dependency
-* **targets**
-  - `arduino-mega2560`: fix flashing on Windows
-  - `arm`: automatically determine stack sizes
-  - `arm64`: make dynamic loader structs and constants private
-  - `avr`: configure emulator in board files
-  - `cortexm`: fix stack size calculation with interrupts
-  - `flash`: add openocd settings to atsamd21 / atsamd51
-  - `flash`: add openocd settings to nrf5
-  - `microbit`: reelboard: flash using OpenOCD when needed
-  - `nintendoswitch`: Add dynamic loader for runtime loading PIE sections
-  - `nintendoswitch`: fix import cycle on dynamic_arm64.go
-  - `nintendoswitch`: Fix invalid memory read / write in print calls
-  - `nintendoswitch`: simplified assembly code
-  - `nintendoswitch`: support outputting .nro files directly
-* **boards**
-  - `arduino-zero`: Adding support for the Arduino Zero (#1365)
-  - `atsamd2x`: fix BAUD value
-  - `atsamd5x`: fix BAUD value
-  - `bluepill`: Enable stm32's USART2 for the board and map it to UART1 tinygo's device
-  - `device/atsamd51x`: add all remaining bitfield values for PCHCTRLm Mapping
-  - `esp32`: add libgcc ROM functions to linker script
-  - `esp32`: add SPI support
-  - `esp32`: add support for basic GPIO
-  - `esp32`: add support for the Espressif ESP32 chip
-  - `esp32`: configure the I/O matrix for GPIO pins
-  - `esp32`: export machine.PortMask* for bitbanging implementations
-  - `esp8266`: add support for this chip
-  - `machine/atsamd51x,runtime/atsamd51x`: fixes needed for full support for all PWM pins. Also adds some useful constants to clarify peripheral clock usage
-  - `machine/itsybitsy-nrf52840`: add support for Adafruit Itsybitsy nrf52840 (#1243)
-  - `machine/stm32f4`: refactor common code and add new build tag stm32f4 (#1332)
-  - `nrf`: add SoftDevice support for the Circuit Playground Bluefruit
-  - `nrf`: call sd_app_evt_wait when the SoftDevice is enabled
-  - `nrf52840`: add build tags for SoftDevice support
-  - `nrf52840`: use higher priority for USB-CDC code
-  - `runtime/atsamd51x`: use PCHCTRL_GCLK_SERCOMX_SLOW for setting clocks on all SERCOM ports
-  - `stm32f405`: add basic UART handler
-  - `stm32f405`: add STM32F405 machine/runtime, and new board/target feather-stm32f405
-* **build**
-  - `all`: run test binaries in the correct directory
-  - `build`: Fix arch release job
-  - `ci`: run `tinygo test` for known-working packages
-  - `ci`: set git-fetch-depth to 1
-  - `docker`: fix the problem with the wasm build (#1357)
-  - `Makefile`: check whether submodules have been downloaded in some common cases
-* **docs**
-  - add ESP32, ESP8266, and Adafruit Feather STM32F405 to list of supported boards
-
-0.14.1
---
-* **command-line**
-  - support for Go 1.15
-* **compiler**
-  - loader:  work around Windows symlink limitation
-
-0.14.0
---
-* **command-line**
-  - fix `getDefaultPort()` on non-English Windows locales
-  - compileopts: improve error reporting of unsupported flags
-  - fix test subcommand
-  - use auto-retry to locate MSD for UF2 and HEX flashing
-  - fix touchSerialPortAt1200bps on Windows
-  - support package names with backslashes on Windows
-* **compiler**
-  - fix a few crashes due to named types
-  - add support for atomic operations
-  - move the channel blocked list onto the stack
-  - fix -gc=none
-  - fix named string to `[]byte` slice conversion
-  - implement func value and builtin defers
-  - add proper parameter names to runtime.initAll, to fix a panic
-  - builder: fix picolibc include path
-  - builder: use newer version of gohex
-  - builder: try to determine stack size information at compile time
-  - builder: remove -opt=0
-  - interp: fix sync/atomic.Value load/store methods
-  - loader: add Go module support
-  - transform: fix debug information in func lowering pass
-  - transform: do not special-case zero or one implementations of a method call
-  - transform: introduce check for method calls on nil interfaces
-  - transform: gc: track 0-index GEPs to fix miscompilation
-* **cgo**
-  - Add LDFlags support
-* **standard library**
-  - extend stdlib to allow import of more packages
-  - replace master/slave terminology with appropriate alternatives (MOSI->SDO
-    etc)
-  - `internal/bytealg`: reimplement bytealg in pure Go
-  - `internal/task`: fix nil panic in (*internal/task.Stack).Pop
-  - `os`: add Args and stub it with mock data
-  - `os`: implement virtual filesystem support
-  - `reflect`: add Cap and Len support for map and chan
-  - `runtime`: fix return address in scheduler on RISC-V
-  - `runtime`: avoid recursion in printuint64 function
-  - `runtime`: replace ReadRegister with AsmFull inline assembly
-  - `runtime`: fix compilation errors when using gc.extalloc
-  - `runtime`: add cap and len support for chans
-  - `runtime`: refactor time handling (improving accuracy)
-  - `runtime`: make channels work in interrupts
-  - `runtime/interrupt`: add cross-chip disable/restore interrupt support
-  - `sync`: implement `sync.Cond`
-  - `sync`: add WaitGroup
-* **targets**
-  - `arm`: allow nesting in DisableInterrupts and EnableInterrupts
-  - `arm`: make FPU configuraton consistent
-  - `arm`: do not mask fault handlers in critical sections
-  - `atmega2560`: fix pin mapping for pins D2, D5 and the L port
-  - `atsamd`: return an error when an incorrect PWM pin is used
-  - `atsamd`: add support for pin change interrupts
-  - `atsamd`: add DAC support
-  - `atsamd21`: add more ADC pins
-  - `atsamd51`: fix ROM / RAM size on atsamd51j20
-  - `atsamd51`: add more pins
-  - `atsamd51`: add more ADC pins
-  - `atsamd51`: add pin change interrupt settings
-  - `atsamd51`: extend pinPadMapping
-  - `arduino-nano33`: use (U)SB flag to ensure that device can be found when
-     not on default port
-  - `arduino-nano33`: remove (d)ebug flag to reduce console noise when flashing
-  - `avr`: use standard pin numbering
-  - `avr`: unify GPIO pin/port code
-  - `avr`: add support for PinInputPullup
-  - `avr`: work around codegen bug in LLVM 10
-  - `avr`: fix target triple
-  - `fe310`: remove extra println left in by mistake
-  - `feather-nrf52840`: add support for the Feather nRF52840
-  - `maixbit`: add board definition and dummy runtime
-  - `nintendoswitch`: Add experimental Nintendo Switch support without CRT
-  - `nrf`: expose the RAM base address
-  - `nrf`: add support for pin change interrupts
-  - `nrf`: add microbit-s110v8 target
-  - `nrf`: fix bug in SPI.Tx
-  - `nrf`: support debugging the PCA10056
-  - `pygamer`: add Adafruit PyGamer suport
-  - `riscv`: fix interrupt configuration bug
-  - `riscv`: disable linker relaxations during gp init
-  - `stm32f4disco`: add new target with ST-Link v2.1 debugger
-  - `teensy36`: add Teensy 3.6 support
-  - `wasm`: fix event handling
-  - `wasm`: add --no-demangle linker option
-  - `wioterminal`: add support for the Seeed Wio Terminal
-  - `xiao`: add support for the Seeed XIAO
-
 0.13.1
 ---
 * **standard library**
@@ -32,7 +32,7 @@ Microcontrollers have lots of peripherals (I2C, SPI, ADC, etc.) and many don't h

 ## How to use our Github repository

-The `release` branch of this repo will always have the latest released version of TinyGo. All of the active development work for the next release will take place in the `dev` branch. TinyGo will use semantic versioning and will create a tag/release for each release.
+The `master` branch of this repo will always have the latest released version of TinyGo. All of the active development work for the next release will take place in the `dev` branch. TinyGo will use semantic versioning and will create a tag/release for each release.

 Here is how to contribute back some code or documentation:

@@ -15,4 +15,4 @@ Ayke van Laethem <aykevanlaethem@gmail.com>
 Daniel Esteban <conejo@conejo.me>
 Loon, LLC.
 Ron Evans <ron@hybridgroup.com>
-Nia Weiss <niaow1234@gmail.com>
+Jaden Weiss <jaden@jadendw.dev>
@@ -1,10 +1,10 @@
-# TinyGo base stage installs the most recent Go 1.15.x, LLVM 11 and the TinyGo compiler itself.
-FROM golang:1.15 AS tinygo-base
+# TinyGo base stage installs Go 1.14, LLVM 10 and the TinyGo compiler itself.
+FROM golang:1.14 AS tinygo-base

 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
-    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-11 main" >> /etc/apt/sources.list && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main" >> /etc/apt/sources.list && \
    apt-get update && \
-    apt-get install -y llvm-11-dev libclang-11-dev lld-11 git
+    apt-get install -y llvm-10-dev libclang-10-dev git

 COPY . /tinygo

@@ -27,10 +27,10 @@ COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
 COPY --from=tinygo-base /tinygo/src /tinygo/src
 COPY --from=tinygo-base /tinygo/targets /tinygo/targets

-RUN cd /tinygo/ && \
+RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main" >> /etc/apt/sources.list && \
    apt-get update && \
-    apt-get install -y make clang-11 libllvm11 lld-11 && \
-    make wasi-libc
+    apt-get install -y libllvm10 lld-10

 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
 FROM tinygo-base AS tinygo-avr
@@ -61,7 +61,7 @@ COPY --from=tinygo-base /tinygo/lib /tinygo/lib

 RUN cd /tinygo/ && \
    apt-get update && \
-    apt-get install -y apt-utils make clang-11 && \
+    apt-get install -y apt-utils make clang-10 && \
    make gen-device-nrf && make gen-device-stm32

 # tinygo-all stage installs the needed dependencies to compile TinyGo programs for all platforms.
@@ -73,7 +73,7 @@ COPY --from=tinygo-base /tinygo/lib /tinygo/lib

 RUN cd /tinygo/ && \
    apt-get update && \
-    apt-get install -y apt-utils make clang-11 binutils-avr gcc-avr avr-libc && \
+    apt-get install -y apt-utils make clang-10 binutils-avr gcc-avr avr-libc && \
    make gen-device

 CMD ["tinygo"]
@@ -1,7 +1,7 @@
-Copyright (c) 2018-2021 TinyGo Authors. All rights reserved.
+Copyright (c) 2018-2020 TinyGo Authors. All rights reserved.

 TinyGo includes portions of the Go standard library.
-Copyright (c) 2009-2021 The Go Authors. All rights reserved.
+Copyright (c) 2009-2020 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.
@@ -9,10 +9,25 @@ CLANG_SRC ?= $(LLVM_PROJECTDIR)/clang
 LLD_SRC ?= $(LLVM_PROJECTDIR)/lld

 # Try to autodetect LLVM build tools.
-detect = $(shell command -v $(1) 2> /dev/null && echo $(1))
-CLANG ?= $(word 1,$(abspath $(call detect,llvm-build/bin/clang))$(call detect,clang-11)$(call detect,clang-10)$(call detect,clang))
-LLVM_AR ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-ar))$(call detect,llvm-ar-11)$(call detect,llvm-ar-10)$(call detect,llvm-ar))
-LLVM_NM ?= $(word 1,$(abspath $(call detect,llvm-build/bin/llvm-nm))$(call detect,llvm-nm-11)$(call detect,llvm-nm-10)$(call detect,llvm-nm))
+ifneq (, $(shell command -v llvm-build/bin/clang 2> /dev/null))
+    CLANG ?= $(abspath llvm-build/bin/clang)
+else
+    CLANG ?= clang-10
+endif
+ifneq (, $(shell command -v llvm-build/bin/llvm-ar 2> /dev/null))
+    LLVM_AR ?= $(abspath llvm-build/bin/llvm-ar)
+else ifneq (, $(shell command -v llvm-ar-10 2> /dev/null))
+    LLVM_AR ?= llvm-ar-10
+else
+    LLVM_AR ?= llvm-ar
+endif
+ifneq (, $(shell command -v llvm-build/bin/llvm-nm 2> /dev/null))
+    LLVM_NM ?= $(abspath llvm-build/bin/llvm-nm)
+else ifneq (, $(shell command -v llvm-nm-10 2> /dev/null))
+    LLVM_NM ?= llvm-nm-10
+else
+    LLVM_NM ?= llvm-nm
+endif

 # Go binary and GOROOT to select
 GO ?= go
@@ -22,7 +37,7 @@ export GOROOT = $(shell $(GO) env GOROOT)
 MD5SUM = md5sum

 # tinygo binary for tests
-TINYGO ?= $(word 1,$(call detect,tinygo)$(call detect,build/tinygo))
+TINYGO ?= tinygo

 # Use CCACHE for LLVM if possible
 ifneq (, $(shell command -v ccache 2> /dev/null))
@@ -36,7 +51,7 @@ else
    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=OFF'
 endif

-.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-nxp gen-device-avr
+.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-avr

 LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines coverage debuginfodwarf executionengine frontendopenmp instrumentation interpreter ipo irreader linker lto mc mcjit objcarcopts option profiledata scalaropts support target

@@ -48,72 +63,64 @@ ifeq ($(OS),Windows_NT)
    # 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 -DLLVM_ENABLE_PIC=OFF
+    LLVM_OPTION += -DLLVM_ENABLE_THREADS=OFF

-    CGO_CPPFLAGS += -DCINDEX_NO_EXPORTS
    CGO_LDFLAGS += -static -static-libgcc -static-libstdc++
    CGO_LDFLAGS_EXTRA += -lversion

-    LIBCLANG_NAME = libclang
+    # 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_NAME = clang
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
 else ifeq ($(shell uname -s),FreeBSD)
    MD5SUM = md5
-    LIBCLANG_NAME = clang
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
    START_GROUP = -Wl,--start-group
    END_GROUP = -Wl,--end-group
 else
-    LIBCLANG_NAME = clang
+    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
    START_GROUP = -Wl,--start-group
    END_GROUP = -Wl,--end-group
 endif

-# Libraries that should be linked in for the statically linked Clang.
-CLANG_LIB_NAMES = clangAnalysis clangARCMigrate clangAST clangASTMatchers clangBasic clangCodeGen clangCrossTU clangDriver clangDynamicASTMatchers clangEdit clangFormat clangFrontend clangFrontendTool clangHandleCXX clangHandleLLVM clangIndex clangLex clangParse clangRewrite clangRewriteFrontend clangSema clangSerialization clangStaticAnalyzerCheckers clangStaticAnalyzerCore clangStaticAnalyzerFrontend clangTooling clangToolingASTDiff clangToolingCore clangToolingInclusions
-CLANG_LIBS = $(START_GROUP) $(addprefix -l,$(CLANG_LIB_NAMES)) $(END_GROUP) -lstdc++
+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++

-# Libraries that should be linked in for the statically linked LLD.
-LLD_LIB_NAMES = lldCOFF lldCommon lldCore lldDriver lldELF lldMachO lldMinGW lldReaderWriter lldWasm lldYAML
-LLD_LIBS = $(START_GROUP) $(addprefix -l,$(LLD_LIB_NAMES)) $(END_GROUP)
+LLD_LIBS = $(START_GROUP) -llldCOFF -llldCommon -llldCore -llldDriver -llldELF -llldMachO -llldMinGW -llldReaderWriter -llldWasm -llldYAML $(END_GROUP)

-# Other libraries that are needed to link TinyGo.
-EXTRA_LIB_NAMES = LLVMInterpreter
-
-# These build targets appear to be the only ones necessary to build all TinyGo
-# dependencies. Only building a subset significantly speeds up rebuilding LLVM.
-# The Makefile rules convert a name like lldELF to lib/liblldELF.a to match the
-# library path (for ninja).
-# This list also includes a few tools that are necessary as part of the full
-# TinyGo build.
-NINJA_BUILD_TARGETS = clang llvm-config llvm-ar llvm-nm $(addprefix lib/lib,$(addsuffix .a,$(LIBCLANG_NAME) $(CLANG_LIB_NAMES) $(LLD_LIB_NAMES) $(EXTRA_LIB_NAMES)))

 # For static linking.
 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 $(LLD_SRC))/include
+    CGO_CPPFLAGS=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
    CGO_CXXFLAGS=-std=c++14
-    CGO_LDFLAGS+=$(abspath $(LLVM_BUILDDIR))/lib/lib$(LIBCLANG_NAME).a -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
+    CGO_LDFLAGS+=$(LIBCLANG_PATH) -std=c++14 -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 loader src/device/arm src/examples src/machine src/os src/reflect src/runtime src/sync src/syscall src/internal/reflectlite transform
+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:
 	@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


-gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-kendryte gen-device-nxp
-ifneq ($(STM32), 0)
-gen-device: gen-device-stm32
-endif
+gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32

 gen-device-avr:
-	@if [ ! -e lib/avr/README.md ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	$(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/
@@ -122,18 +129,10 @@ gen-device-avr:
 build/gen-device-svd: ./tools/gen-device-svd/*.go
 	$(GO) build -o $@ ./tools/gen-device-svd/

-gen-device-esp: build/gen-device-svd
-	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Espressif-Community -interrupts=software lib/cmsis-svd/data/Espressif-Community/ src/device/esp/
-	GO111MODULE=off $(GO) fmt ./src/device/esp
-
 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-nxp: build/gen-device-svd
-	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/NXP lib/cmsis-svd/data/NXP/ src/device/nxp/
-	GO111MODULE=off $(GO) fmt ./src/device/nxp
-
 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
@@ -142,73 +141,48 @@ 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-kendryte: build/gen-device-svd
-	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Kendryte-Community -interrupts=software lib/cmsis-svd/data/Kendryte-Community/ src/device/kendryte/
-	GO111MODULE=off $(GO) fmt ./src/device/kendryte
-
 gen-device-stm32: build/gen-device-svd
-	./build/gen-device-svd -source=https://github.com/tinygo-org/stm32-svd lib/stm32-svd/svd src/device/stm32/
+	./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_PROJECTDIR)/llvm:
-	git clone -b xtensa_release_11.0.0 --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
-llvm-source: $(LLVM_PROJECTDIR)/llvm
+$(LLVM_PROJECTDIR)/README.md:
+	git clone -b release/10.x https://github.com/llvm/llvm-project $(LLVM_PROJECTDIR)
+llvm-source: $(LLVM_PROJECTDIR)/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_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR;Xtensa" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_LIBEDIT=OFF -DLLVM_ENABLE_Z3_SOLVER=OFF -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
+	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/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 $(NINJA_BUILD_TARGETS)
+	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:
-	@if [ ! -e lib/wasi-libc/Makefile ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	cd lib/wasi-libc && make -j4 WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)


 # Build the Go compiler.
 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)" $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X main.gitSha1=`git rev-parse --short HEAD`" .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -o build/tinygo$(EXE) -tags byollvm .

 test: wasi-libc
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./builder ./cgo ./compileopts ./compiler ./interp ./transform .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -tags byollvm ./cgo ./compileopts ./interp ./transform .

-TEST_PACKAGES = \
-	container/heap \
-	container/list \
-	container/ring \
-	crypto/des \
-	encoding \
-	encoding/ascii85 \
-	encoding/base32 \
-	encoding/hex \
-	hash/adler32 \
-	hash/fnv \
-	hash/crc64 \
-	math \
-	math/cmplx \
-	text/scanner \
-	unicode/utf8 \
-
-# Test known-working standard library packages.
-# TODO: parallelize, and only show failing tests (no implied -v flag).
-.PHONY: tinygo-test
 tinygo-test:
-	$(TINYGO) test $(TEST_PACKAGES)
+	cd tests/tinygotest && tinygo test

 .PHONY: smoketest
 smoketest:
 	$(TINYGO) version
-	# test all examples (except pwm)
+	# test all examples
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/adc
@@ -229,7 +203,7 @@ smoketest:
 	@$(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/pininterrupt
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pwm
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial
 	@$(MD5SUM) test.hex
@@ -240,6 +214,8 @@ smoketest:
 	# test simulated boards on play.tinygo.org
 	$(TINYGO) build             -o test.wasm -tags=arduino              examples/blinky1
 	@$(MD5SUM) test.wasm
+	$(TINYGO) build             -o test.wasm -tags=hifive1-qemu         examples/serial
+	@$(MD5SUM) test.wasm
 	$(TINYGO) build             -o test.wasm -tags=hifive1b             examples/blinky1
 	@$(MD5SUM) test.wasm
 	$(TINYGO) build             -o test.wasm -tags=reelboard            examples/blinky1
@@ -255,16 +231,12 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=microbit            examples/echo
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=microbit-s110v8     examples/echo
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=microbit-v2         examples/microbit-blink
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=microbit-v2-s113v7  examples/microbit-blink
-	@$(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
 	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky2
@@ -273,10 +245,6 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10056            examples/blinky2
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pca10059            examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pca10059            examples/blinky2
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-m0          examples/blinky1
@@ -285,16 +253,18 @@ smoketest:
 	@$(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.hex -target=clue-alpha          examples/blinky1
+	$(TINYGO) build -size short -o test.hex -target=clue_alpha          examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.gba -target=gameboy-advance     examples/gba-display
 	@$(MD5SUM) test.gba
-	$(TINYGO) build -size short -o test.hex -target=grandcentral-m4     examples/blinky1
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/blinky1
@@ -311,6 +281,8 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=particle-xenon      examples/blinky1
 	@$(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
 	$(TINYGO) build -size short -o test.hex -target=x9pro               examples/blinky1
@@ -319,116 +291,26 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=reelboard-s140v7    examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=wioterminal         examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pygamer             examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=xiao                examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/dac
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/dac
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-nrf52840  	examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=itsybitsy-nrf52840  examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=qtpy  				examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=teensy40            examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=teensy36            examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=p1am-100            examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=atsame54-xpro       examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=atsame54-xpro       examples/can
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-m4-can      examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-m4-can      examples/caninterrupt
-	@$(MD5SUM) test.hex
-	# test pwm
-	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/pwm
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/pwm
-	@$(MD5SUM) test.hex
-ifneq ($(STM32), 0)
-	$(TINYGO) build -size short -o test.hex -target=bluepill            examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-stm32f405   examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=lgt92               examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-f103rb       examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-f722ze       examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-l031k6       examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-l432kc       examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-l552ze       examples/blinky1
-	@$(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
-	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1      examples/blinky1
-	@$(MD5SUM) test.hex
-endif
 ifneq ($(AVR), 0)
 	$(TINYGO) build -size short -o test.hex -target=atmega1284p         examples/serial
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino             examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino             examples/pwm
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino -scheduler=tasks  examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino-mega1280    examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=arduino-mega1280    examples/pwm
-	@$(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
-ifneq ($(XTENSA), 0)
-	$(TINYGO) build -size short -o test.bin -target=esp32-mini32      	examples/blinky1
-	@$(MD5SUM) test.bin
-	$(TINYGO) build -size short -o test.bin -target=nodemcu             examples/blinky1
-	@$(MD5SUM) test.bin
 endif
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=hifive1-qemu        examples/serial
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1
-	@$(MD5SUM) test.hex
 	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/export
 	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/main
-	# test various compiler flags
-	$(TINYGO) build -size short -o test.hex -target=pca10040 -gc=none -scheduler=none examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=1     examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build             -o test.nro -target=nintendoswitch      examples/serial
-	@$(MD5SUM) test.nro
-	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=0     ./testdata/stdlib.go
-	@$(MD5SUM) test.hex

-
-wasmtest:
-	$(GO) test ./tests/wasm
-
-build/release: tinygo gen-device wasi-libc
+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
@@ -463,13 +345,4 @@ build/release: tinygo gen-device wasi-libc
 	./build/tinygo build-library -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/picolibc.a picolibc
 	./build/tinygo build-library -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/picolibc.a picolibc
 	./build/tinygo build-library -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/picolibc.a picolibc
-
-release: build/release
 	tar -czf build/release.tar.gz -C build/release tinygo
-
-deb: build/release
-	@mkdir -p build/release-deb/usr/local/bin
-	@mkdir -p build/release-deb/usr/local/lib
-	cp -ar build/release/tinygo build/release-deb/usr/local/lib/tinygo
-	ln -sf ../lib/tinygo/bin/tinygo build/release-deb/usr/local/bin/tinygo
-	fpm -f -s dir -t deb -n tinygo -v $(shell grep "const Version = " goenv/version.go | awk '{print $$NF}') -m '@tinygo-org' --description='TinyGo is a Go compiler for small places.' --license='BSD 3-Clause' --url=https://tinygo.org/ --deb-changelog CHANGELOG.md -p build/release.deb -C ./build/release-deb
@@ -43,68 +43,38 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for

 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.

-The following 62 microcontroller boards are currently supported:
+The following 32 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 CLUE](https://www.adafruit.com/product/4500)
+* [Adafruit CLUE Alpha](https://www.adafruit.com/product/4500)
 * [Adafruit Feather M0](https://www.adafruit.com/product/2772)
 * [Adafruit Feather M4](https://www.adafruit.com/product/3857)
-* [Adafruit Feather M4 CAN](https://www.adafruit.com/product/4759)
-* [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062)
-* [Adafruit Feather STM32F405 Express](https://www.adafruit.com/product/4382)
-* [Adafruit Grand Central M4](https://www.adafruit.com/product/4064)
 * [Adafruit ItsyBitsy M0](https://www.adafruit.com/product/3727)
 * [Adafruit ItsyBitsy M4](https://www.adafruit.com/product/3800)
-* [Adafruit ItsyBitsy nRF52840](https://www.adafruit.com/product/4481)
-* [Adafruit Matrix Portal M4](https://www.adafruit.com/product/4745)
 * [Adafruit Metro M4 Express Airlift](https://www.adafruit.com/product/4000)
 * [Adafruit PyBadge](https://www.adafruit.com/product/4200)
-* [Adafruit PyGamer](https://www.adafruit.com/product/4242)
 * [Adafruit PyPortal](https://www.adafruit.com/product/4116)
-* [Adafruit QT Py](https://www.adafruit.com/product/4600)
 * [Adafruit Trinket M0](https://www.adafruit.com/product/3500)
-* [Arduino Mega 1280](https://www.arduino.cc/en/Main/arduinoBoardMega/)
 * [Arduino Mega 2560](https://store.arduino.cc/arduino-mega-2560-rev3)
-* [Arduino MKR1000](https://store.arduino.cc/arduino-mkr1000-wifi)
 * [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)
-* [Arduino Zero](https://store.arduino.cc/usa/arduino-zero)
 * [BBC micro:bit](https://microbit.org/)
-* [BBC micro:bit v2](https://microbit.org/new-microbit/)
 * [Digispark](http://digistump.com/products/1)
-* [Dragino LoRaWAN GPS Tracker LGT-92](http://www.dragino.com/products/lora-lorawan-end-node/item/142-lgt-92.html)
-* [ESP32](https://www.espressif.com/en/products/socs/esp32)
-* [ESP8266](https://www.espressif.com/en/products/socs/esp8266)
 * [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
 * [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
-* [Makerdiary nRF52840-MDK USB Dongle](https://wiki.makerdiary.com/nrf52840-mdk-usb-dongle/)
-* [Microchip SAM E54 Xplained Pro](https://www.microchip.com/developmenttools/productdetails/atsame54-xpro)
-* [nice!nano](https://docs.nicekeyboards.com/#/nice!nano/)
-* [Nintendo Switch](https://www.nintendo.com/switch/)
 * [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)
-* [Nordic Semiconductor pca10059](https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52840-Dongle)
 * [Particle Argon](https://docs.particle.io/datasheets/wi-fi/argon-datasheet/)
 * [Particle Boron](https://docs.particle.io/datasheets/cellular/boron-datasheet/)
 * [Particle Xenon](https://docs.particle.io/datasheets/discontinued/xenon-datasheet/)
 * [Phytec reel board](https://www.phytec.eu/product-eu/internet-of-things/reelboard/)
 * [PineTime DevKit](https://www.pine64.org/pinetime/)
-* [PJRC Teensy 3.6](https://www.pjrc.com/store/teensy36.html)
-* [PJRC Teensy 4.0](https://www.pjrc.com/store/teensy40.html)
-* [ProductivityOpen P1AM-100](https://facts-engineering.github.io/modules/P1AM-100/P1AM-100.html)
-* [Seeed Wio Terminal](https://www.seeedstudio.com/Wio-Terminal-p-4509.html)
-* [Seeed Seeeduino XIAO](https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html)
-* [Seeed Sipeed MAix BiT](https://www.seeedstudio.com/Sipeed-MAix-BiT-for-RISC-V-AI-IoT-p-2872.html)
 * [SiFIve HiFive1](https://www.sifive.com/boards/hifive1)
-* [ST Micro "Nucleo" F103RB](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
-* [ST Micro "Nucleo" F722ZE](https://www.st.com/en/evaluation-tools/nucleo-f722ze.html)
-* [ST Micro "Nucleo" L031K6](https://www.st.com/ja/evaluation-tools/nucleo-l031k6.html)
-* [ST Micro "Nucleo" L432KC](https://www.st.com/ja/evaluation-tools/nucleo-l432kc.html)
-* [ST Micro "Nucleo" L552ZE](https://www.st.com/en/evaluation-tools/nucleo-l552ze-q.html)
-* [ST Micro STM32F103XX "Bluepill"](https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill)
+* [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/)

@@ -166,6 +136,4 @@ The original reasoning was: if [Python](https://micropython.org/) can run on mic

 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/11.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.
-
-Some code has been copied and/or ported from Paul Stoffregen's Teensy libraries and is therefore licensed under PJRC's license. This has been clearly indicated in the header of these files.
+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/10.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.
@@ -1,7 +1,7 @@
 # Avoid lengthy LLVM rebuilds on each newly pushed branch. Pull requests will
 # be built anyway.
 trigger:
- release
+- master
 - dev

 jobs:
@@ -12,13 +12,12 @@ jobs:
  steps:
    - task: GoTool@0
      inputs:
-        version: '1.16'
+        version: '1.14.1'
    - checkout: self
-      fetchDepth: 1
-    - task: Cache@2
+    - task: CacheBeta@0
      displayName: Cache LLVM source
      inputs:
-        key: llvm-source-11-windows-v1
+        key: llvm-source-10-windows-v0
        path: llvm-project
    - task: Bash@3
      displayName: Download LLVM source
@@ -28,7 +27,7 @@ jobs:
    - task: CacheBeta@0
      displayName: Cache LLVM build
      inputs:
-        key: llvm-build-11-windows-v4
+        key: llvm-build-10-windows-v0
        path: llvm-build
    - task: Bash@3
      displayName: Build LLVM
@@ -37,22 +36,18 @@ jobs:
        script: |
          if [ ! -f llvm-build/lib/liblldELF.a ]
          then
-            # install dependencies
            choco install ninja
-            # hack ninja to use fewer jobs
-            echo -e 'C:\\ProgramData\\Chocolatey\\bin\\ninja -j4 %*' > /usr/bin/ninja.bat
-            # build!
            make llvm-build
          fi
    - task: Bash@3
      displayName: Install QEMU
      inputs:
        targetType: inline
-        script: choco install qemu --version=2020.06.12
+        script: choco install qemu
    - task: CacheBeta@0
      displayName: Cache wasi-libc sysroot
      inputs:
-        key: wasi-libc-sysroot-v4
+        key: wasi-libc-sysroot-v2
        path: lib/wasi-libc/sysroot
    - task: Bash@3
      displayName: Build wasi-libc
@@ -74,7 +69,7 @@ jobs:
        script: |
          export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
          unset GOROOT
-          make build/release -j4
+          make release -j4
    - publish: $(System.DefaultWorkingDirectory)/build/release/tinygo
      displayName: Publish zip as artifact
      artifact: tinygo
@@ -85,4 +80,4 @@ jobs:
        script: |
          export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
          unset GOROOT
-          make smoketest TINYGO=build/tinygo AVR=0 XTENSA=0
+          make smoketest TINYGO=build/tinygo AVR=0
@@ -30,7 +30,10 @@ func cacheTimestamp(paths []string) (time.Time, error) {
 // Try to load a given file from the cache. Return "", nil if no cached file can
 // be found (or the file is stale), return the absolute path if there is a cache
 // and return an error on I/O errors.
-func cacheLoad(name string, sourceFiles []string) (string, 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) {
 	cachepath := filepath.Join(goenv.Get("GOCACHE"), name)
 	cacheStat, err := os.Stat(cachepath)
 	if os.IsNotExist(err) {
@@ -55,7 +58,9 @@ func cacheLoad(name string, sourceFiles []string) (string, error) {

 // Store the file located at tmppath in the cache with the given name. The
 // tmppath may or may not be gone afterwards.
-func cacheStore(tmppath, name string, sourceFiles []string) (string, error) {
+//
+// Note: the configKey is ignored, see cacheLoad.
+func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string, error) {
 	// get the last modified time
 	if len(sourceFiles) == 0 {
 		panic("cache: no source files")
@@ -69,16 +74,24 @@ func cacheStore(tmppath, name string, sourceFiles []string) (string, error) {
 		return "", err
 	}
 	cachepath := filepath.Join(dir, name)
-	err = copyFile(tmppath, cachepath)
+	err = moveFile(tmppath, cachepath)
 	if err != nil {
 		return "", err
 	}
 	return cachepath, nil
 }

-// copyFile copies the given file from src to dst. It can copy over
-// a possibly already existing file at the destination.
-func copyFile(src, dst string) error {
+// moveFile renames the file from src to dst. If renaming doesn't work (for
+// example, the rename crosses a filesystem boundary), the file is copied and
+// the old file is removed.
+func moveFile(src, dst string) error {
+	err := os.Rename(src, dst)
+	if err == nil {
+		// Success!
+		return nil
+	}
+	// Failed to move, probably a different filesystem.
+	// Do a copy + remove.
 	inf, err := os.Open(src)
 	if err != nil {
 		return err
@@ -1,309 +0,0 @@
-package builder
-
-// This file implements a wrapper around the C compiler (Clang) which uses a
-// build cache.
-
-import (
-	"crypto/sha512"
-	"encoding/hex"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"sort"
-	"strings"
-	"unicode"
-
-	"github.com/tinygo-org/tinygo/goenv"
-	"tinygo.org/x/go-llvm"
-)
-
-// compileAndCacheCFile compiles a C or assembly file using a build cache.
-// Compiling the same file again (if nothing changed, including included header
-// files) the output is loaded from the build cache instead.
-//
-// Its operation is a bit complex (more complex than Go package build caching)
-// because the list of file dependencies is only known after the file is
-// compiled. However, luckily compilers have a flag to write a list of file
-// dependencies in Makefile syntax which can be used for caching.
-//
-// Because of this complexity, every file has in fact two cached build outputs:
-// the file itself, and the list of dependencies. Its operation is as follows:
-//
-//   depfile = hash(path, compiler, cflags, ...)
-//   if depfile exists:
-//     outfile = hash of all files and depfile name
-//     if outfile exists:
-//       # cache hit
-//       return outfile
-//   # cache miss
-//   tmpfile = compile file
-//   read dependencies (side effect of compile)
-//   write depfile
-//   outfile = hash of all files and depfile name
-//   rename tmpfile to outfile
-//
-// There are a few edge cases that are not handled:
-// - If a file is added to an include path, that file may be included instead of
-//   some other file. This would be fixed by also including lookup failures in the
-//   dependencies file, but I'm not aware of a compiler which does that.
-// - The Makefile syntax that compilers output has issues, see readDepFile for
-//   details.
-// - A header file may be changed to add/remove an include. This invalidates the
-//   depfile but without invalidating its name. For this reason, the depfile is
-//   written on each new compilation (even when it seems unnecessary). However, it
-//   could in rare cases lead to a stale file fetched from the cache.
-func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands bool) (string, error) {
-	// Hash input file.
-	fileHash, err := hashFile(abspath)
-	if err != nil {
-		return "", err
-	}
-
-	// Create cache key for the dependencies file.
-	buf, err := json.Marshal(struct {
-		Path        string
-		Hash        string
-		Flags       []string
-		LLVMVersion string
-	}{
-		Path:        abspath,
-		Hash:        fileHash,
-		Flags:       cflags,
-		LLVMVersion: llvm.Version,
-	})
-	if err != nil {
-		panic(err) // shouldn't happen
-	}
-	depfileNameHashBuf := sha512.Sum512_224(buf)
-	depfileNameHash := hex.EncodeToString(depfileNameHashBuf[:])
-
-	// Load dependencies file, if possible.
-	depfileName := "dep-" + depfileNameHash + ".json"
-	depfileCachePath := filepath.Join(goenv.Get("GOCACHE"), depfileName)
-	depfileBuf, err := ioutil.ReadFile(depfileCachePath)
-	var dependencies []string // sorted list of dependency paths
-	if err == nil {
-		// There is a dependency file, that's great!
-		// Parse it first.
-		err := json.Unmarshal(depfileBuf, &dependencies)
-		if err != nil {
-			return "", fmt.Errorf("could not parse dependencies JSON: %w", err)
-		}
-
-		// Obtain hashes of all the files listed as a dependency.
-		outpath, err := makeCFileCachePath(dependencies, depfileNameHash)
-		if err == nil {
-			if _, err := os.Stat(outpath); err == nil {
-				return outpath, nil
-			} else if !os.IsNotExist(err) {
-				return "", err
-			}
-		}
-	} else if !os.IsNotExist(err) {
-		// expected either nil or IsNotExist
-		return "", err
-	}
-
-	objTmpFile, err := ioutil.TempFile(goenv.Get("GOCACHE"), "tmp-*.o")
-	if err != nil {
-		return "", err
-	}
-	objTmpFile.Close()
-	depTmpFile, err := ioutil.TempFile(tmpdir, "dep-*.d")
-	if err != nil {
-		return "", err
-	}
-	depTmpFile.Close()
-	flags := append([]string{}, cflags...)                                   // copy cflags
-	flags = append(flags, "-MD", "-MV", "-MTdeps", "-MF", depTmpFile.Name()) // autogenerate dependencies
-	flags = append(flags, "-c", "-o", objTmpFile.Name(), abspath)
-	if strings.ToLower(filepath.Ext(abspath)) == ".s" {
-		// If this is an assembly file (.s or .S, lowercase or uppercase), then
-		// we'll need to add -Qunused-arguments because many parameters are
-		// relevant to C, not assembly. And with -Werror, having meaningless
-		// flags (for the assembler) is a compiler error.
-		flags = append(flags, "-Qunused-arguments")
-	}
-	if printCommands {
-		fmt.Printf("clang %s\n", strings.Join(flags, " "))
-	}
-	err = runCCompiler(flags...)
-	if err != nil {
-		return "", &commandError{"failed to build", abspath, err}
-	}
-
-	// Create sorted and uniqued slice of dependencies.
-	dependencyPaths, err := readDepFile(depTmpFile.Name())
-	if err != nil {
-		return "", err
-	}
-	dependencyPaths = append(dependencyPaths, abspath) // necessary for .s files
-	dependencySet := make(map[string]struct{}, len(dependencyPaths))
-	var dependencySlice []string
-	for _, path := range dependencyPaths {
-		if _, ok := dependencySet[path]; ok {
-			continue
-		}
-		dependencySet[path] = struct{}{}
-		dependencySlice = append(dependencySlice, path)
-	}
-	sort.Strings(dependencySlice)
-
-	// Write dependencies file.
-	f, err := ioutil.TempFile(filepath.Dir(depfileCachePath), depfileName)
-	buf, err = json.MarshalIndent(dependencySlice, "", "\t")
-	if err != nil {
-		panic(err) // shouldn't happen
-	}
-	_, err = f.Write(buf)
-	if err != nil {
-		return "", err
-	}
-	err = f.Close()
-	if err != nil {
-		return "", err
-	}
-	err = os.Rename(f.Name(), depfileCachePath)
-	if err != nil {
-		return "", err
-	}
-
-	// Move temporary object file to final location.
-	outpath, err := makeCFileCachePath(dependencySlice, depfileNameHash)
-	if err != nil {
-		return "", err
-	}
-	err = os.Rename(objTmpFile.Name(), outpath)
-	if err != nil {
-		return "", err
-	}
-
-	return outpath, nil
-}
-
-// Create a cache path (a path in GOCACHE) to store the output of a compiler
-// job. This path is based on the dep file name (which is a hash of metadata
-// including compiler flags) and the hash of all input files in the paths slice.
-func makeCFileCachePath(paths []string, depfileNameHash string) (string, error) {
-	// Hash all input files.
-	fileHashes := make(map[string]string, len(paths))
-	for _, path := range paths {
-		hash, err := hashFile(path)
-		if err != nil {
-			return "", err
-		}
-		fileHashes[path] = hash
-	}
-
-	// Calculate a cache key based on the above hashes.
-	buf, err := json.Marshal(struct {
-		DepfileHash string
-		FileHashes  map[string]string
-	}{
-		DepfileHash: depfileNameHash,
-		FileHashes:  fileHashes,
-	})
-	if err != nil {
-		panic(err) // shouldn't happen
-	}
-	outFileNameBuf := sha512.Sum512_224(buf)
-	cacheKey := hex.EncodeToString(outFileNameBuf[:])
-
-	outpath := filepath.Join(goenv.Get("GOCACHE"), "obj-"+cacheKey+".o")
-	return outpath, nil
-}
-
-// hashFile hashes the given file path and returns the hash as a hex string.
-func hashFile(path string) (string, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return "", fmt.Errorf("failed to hash file: %w", err)
-	}
-	defer f.Close()
-	fileHasher := sha512.New512_224()
-	_, err = io.Copy(fileHasher, f)
-	if err != nil {
-		return "", fmt.Errorf("failed to hash file: %w", err)
-	}
-	return hex.EncodeToString(fileHasher.Sum(nil)), nil
-}
-
-// readDepFile reads a dependency file in NMake (Visual Studio make) format. The
-// file is assumed to have a single target named deps.
-//
-// There are roughly three make syntax variants:
-// - BSD make, which doesn't support any escaping. This means that many special
-//   characters are not supported in file names.
-// - GNU make, which supports escaping using a backslash but when it fails to
-//   find a file it tries to fall back with the literal path name (to match BSD
-//   make).
-// - NMake (Visual Studio) and Jom, which simply quote the string if there are
-//   any weird characters.
-// Clang supports two variants: a format that's a compromise between BSD and GNU
-// make (and is buggy to match GCC which is equally buggy), and NMake/Jom, which
-// is at least somewhat sane. This last format isn't perfect either: it does not
-// correctly handle filenames with quote marks in them. Those are generally not
-// allowed on Windows, but of course can be used on POSIX like systems. Still,
-// it's the most sane of any of the formats so readDepFile will use that format.
-func readDepFile(filename string) ([]string, error) {
-	buf, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return nil, err
-	}
-	if len(buf) == 0 {
-		return nil, nil
-	}
-	return parseDepFile(string(buf))
-}
-
-func parseDepFile(s string) ([]string, error) {
-	// This function makes no attempt at parsing anything other than Clang -MD
-	// -MV output.
-
-	// For Windows: replace CRLF with LF to make the logic below simpler.
-	s = strings.ReplaceAll(s, "\r\n", "\n")
-
-	// Collapse all lines ending in a backslash. These backslashes are really
-	// just a way to continue a line without making very long lines.
-	s = strings.ReplaceAll(s, "\\\n", " ")
-
-	// Only use the first line, which is expected to begin with "deps:".
-	line := strings.SplitN(s, "\n", 2)[0]
-	if !strings.HasPrefix(line, "deps:") {
-		return nil, errors.New("readDepFile: expected 'deps:' prefix")
-	}
-	line = strings.TrimSpace(line[len("deps:"):])
-
-	var deps []string
-	for line != "" {
-		if line[0] == '"' {
-			// File path is quoted. Path ends with double quote.
-			// This does not handle double quotes in path names, which is a
-			// problem on non-Windows systems.
-			line = line[1:]
-			end := strings.IndexByte(line, '"')
-			if end < 0 {
-				return nil, errors.New("readDepFile: path is incorrectly quoted")
-			}
-			dep := line[:end]
-			line = strings.TrimSpace(line[end+1:])
-			deps = append(deps, dep)
-		} else {
-			// File path is not quoted. Path ends in space or EOL.
-			end := strings.IndexFunc(line, unicode.IsSpace)
-			if end < 0 {
-				// last dependency
-				deps = append(deps, line)
-				break
-			}
-			dep := line[:end]
-			line = strings.TrimSpace(line[end:])
-			deps = append(deps, dep)
-		}
-	}
-	return deps, nil
-}
@@ -101,7 +101,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,

  // Target Options
  Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
-  Opts.CPU = std::string(Args.getLastArgValue(OPT_target_cpu));
+  Opts.CPU = Args.getLastArgValue(OPT_target_cpu);
  Opts.Features = Args.getAllArgValues(OPT_target_feature);

  // Use the default target triple if unspecified.
@@ -132,19 +132,13 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,

  Opts.RelaxELFRelocations = Args.hasArg(OPT_mrelax_relocations);
  Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
-  Opts.DwarfDebugFlags =
-      std::string(Args.getLastArgValue(OPT_dwarf_debug_flags));
-  Opts.DwarfDebugProducer =
-      std::string(Args.getLastArgValue(OPT_dwarf_debug_producer));
-  Opts.DebugCompilationDir =
-      std::string(Args.getLastArgValue(OPT_fdebug_compilation_dir));
-  Opts.MainFileName = std::string(Args.getLastArgValue(OPT_main_file_name));
+  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)) {
-    auto Split = StringRef(Arg).split('=');
-    Opts.DebugPrefixMap.insert(
-        {std::string(Split.first), std::string(Split.second)});
-  }
+  for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ))
+    Opts.DebugPrefixMap.insert(StringRef(Arg).split('='));

  // Frontend Options
  if (Args.hasArg(OPT_INPUT)) {
@@ -160,9 +154,8 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
    }
  }
  Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
-  Opts.OutputPath = std::string(Args.getLastArgValue(OPT_o));
-  Opts.SplitDwarfOutput =
-      std::string(Args.getLastArgValue(OPT_split_dwarf_output));
+  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)
@@ -190,9 +183,8 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
  Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
  Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
  Opts.NoWarn = Args.hasArg(OPT_massembler_no_warn);
-  Opts.RelocationModel =
-      std::string(Args.getLastArgValue(OPT_mrelocation_model, "pic"));
-  Opts.TargetABI = std::string(Args.getLastArgValue(OPT_target_abi));
+  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);
@@ -322,7 +314,12 @@ bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags) {
                            SrcMgr.getMemoryBuffer(BufferIndex)->getBuffer());

  // Build up the feature string from the target feature list.
-  std::string FS = llvm::join(Opts.Features, ",");
+  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;

@@ -386,7 +383,7 @@ bool ExecuteAssembler(AssemblerInvocation &Opts, DiagnosticsEngine &Diags) {
    MCSection *AsmLabel = Ctx.getMachOSection(
        "__LLVM", "__asm", MachO::S_REGULAR, 4, SectionKind::getReadOnly());
    Str.get()->SwitchSection(AsmLabel);
-    Str.get()->emitZeros(1);
+    Str.get()->EmitZeros(1);
  }

  // Assembly to object compilation should leverage assembly info.
@@ -1,33 +0,0 @@
-package builder
-
-import (
-	"reflect"
-	"testing"
-)
-
-func TestSplitDepFile(t *testing.T) {
-	for i, tc := range []struct {
-		in  string
-		out []string
-	}{
-		{`deps: foo bar`, []string{"foo", "bar"}},
-		{`deps: foo "bar"`, []string{"foo", "bar"}},
-		{`deps: "foo" bar`, []string{"foo", "bar"}},
-		{`deps: "foo bar"`, []string{"foo bar"}},
-		{`deps: "foo bar" `, []string{"foo bar"}},
-		{"deps: foo\nbar", []string{"foo"}},
-		{"deps: foo \\\nbar", []string{"foo", "bar"}},
-		{"deps: foo\\bar \\\nbaz", []string{"foo\\bar", "baz"}},
-		{"deps: foo\\bar \\\r\n baz", []string{"foo\\bar", "baz"}}, // Windows uses CRLF line endings
-	} {
-		out, err := parseDepFile(tc.in)
-		if err != nil {
-			t.Errorf("test #%d failed: %v", i, err)
-			continue
-		}
-		if !reflect.DeepEqual(out, tc.out) {
-			t.Errorf("test #%d failed: expected %#v but got %#v", i, tc.out, out)
-			continue
-		}
-	}
-}
@@ -11,7 +11,6 @@
 #include <clang/FrontendTool/Utils.h>
 #include <llvm/ADT/IntrusiveRefCntPtr.h>
 #include <llvm/Option/Option.h>
-#include <llvm/Support/Host.h>

 using namespace llvm;
 using namespace clang;
@@ -17,28 +17,18 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, err
 	}
-
-	if options.OpenOCDCommands != nil {
-		// Override the OpenOCDCommands from the target spec if specified on
-		// the command-line
-		spec.OpenOCDCommands = options.OpenOCDCommands
-	}
-
 	goroot := goenv.Get("GOROOT")
 	if goroot == "" {
 		return nil, errors.New("cannot locate $GOROOT, please set it manually")
 	}
-
 	major, minor, err := goenv.GetGorootVersion(goroot)
 	if err != nil {
 		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
 	}
-	if major != 1 || minor < 13 || minor > 16 {
-		return nil, fmt.Errorf("requires go version 1.13 through 1.16, got go%d.%d", major, minor)
+	if major != 1 || minor < 11 || minor > 14 {
+		return nil, fmt.Errorf("requires go version 1.11, 1.12, 1.13, or 1.14, got go%d.%d", major, minor)
 	}
-
 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
-
 	return &compileopts.Config{
 		Options:        options,
 		Target:         spec,
@@ -6,9 +6,6 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sort"
-	"strings"
-
-	"tinygo.org/x/go-llvm"
 )

 // getClangHeaderPath returns the path to the built-in Clang headers. It tries
@@ -29,7 +26,6 @@ func getClangHeaderPath(TINYGOROOT string) string {

 	// 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.
-	llvmMajor := strings.Split(llvm.Version, ".")[0]
 	for _, cmdName := range commands["clang"] {
 		binpath, err := exec.LookPath(cmdName)
 		if err == nil {
@@ -44,38 +40,22 @@ func getClangHeaderPath(TINYGOROOT string) string {
 			// Example executable:
 			//     /usr/lib/llvm-9/bin/clang
 			// Example include path:
-			//     /usr/lib/llvm-9/lib64/clang/9.0.1/include/
-			llvmRoot := filepath.Dir(filepath.Dir(binpath))
-			clangVersionRoot := filepath.Join(llvmRoot, "lib64", "clang")
-			dirs64, err64 := ioutil.ReadDir(clangVersionRoot)
-			// Example include path:
 			//     /usr/lib/llvm-9/lib/clang/9.0.1/include/
-			clangVersionRoot = filepath.Join(llvmRoot, "lib", "clang")
-			dirs32, err32 := ioutil.ReadDir(clangVersionRoot)
-			if err64 != nil && err32 != nil {
+			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(dirs64)+len(dirs32))
-			dirCount := 0
-			for _, d := range dirs32 {
-				name := d.Name()
-				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
-					dirnames[dirCount] = filepath.Join(llvmRoot, "lib", "clang", name)
-					dirCount++
-				}
-			}
-			for _, d := range dirs64 {
-				name := d.Name()
-				if name == llvmMajor || strings.HasPrefix(name, llvmMajor+".") {
-					dirnames[dirCount] = filepath.Join(llvmRoot, "lib64", "clang", name)
-					dirCount++
-				}
+			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 := dirCount - 1; i >= 0; i-- {
-				path := filepath.Join(dirnames[i], "include")
+			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
@@ -1,153 +0,0 @@
-package builder
-
-// This file implements support for writing ESP image files. These image files
-// are read by the ROM bootloader so have to be in a particular format.
-//
-// In the future, it may be necessary to implement support for other image
-// formats, such as the ESP8266 image formats (again, used by the ROM bootloader
-// to load the firmware).
-
-import (
-	"bytes"
-	"crypto/sha256"
-	"debug/elf"
-	"encoding/binary"
-	"fmt"
-	"io/ioutil"
-	"sort"
-)
-
-type espImageSegment struct {
-	addr uint32
-	data []byte
-}
-
-// makeESPFirmare converts an input ELF file to an image file for an ESP32 or
-// ESP8266 chip. This is a special purpose image format just for the ESP chip
-// family, and is parsed by the on-chip mask ROM bootloader.
-//
-// The following documentation has been used:
-// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
-// https://github.com/espressif/esp-idf/blob/8fbb63c2a701c22ccf4ce249f43aded73e134a34/components/bootloader_support/include/esp_image_format.h#L58
-// https://github.com/espressif/esptool/blob/master/esptool.py
-func makeESPFirmareImage(infile, outfile, format string) error {
-	inf, err := elf.Open(infile)
-	if err != nil {
-		return err
-	}
-	defer inf.Close()
-
-	// Load all segments to be written to the image. These are actually ELF
-	// sections, not true ELF segments (similar to how esptool does it).
-	var segments []*espImageSegment
-	for _, section := range inf.Sections {
-		if section.Type != elf.SHT_PROGBITS || section.Size == 0 || section.Flags&elf.SHF_ALLOC == 0 {
-			continue
-		}
-		data, err := section.Data()
-		if err != nil {
-			return fmt.Errorf("failed to read section data: %w", err)
-		}
-		for len(data)%4 != 0 {
-			// Align segment to 4 bytes.
-			data = append(data, 0)
-		}
-		if uint64(uint32(section.Addr)) != section.Addr {
-			return fmt.Errorf("section address too big: 0x%x", section.Addr)
-		}
-		segments = append(segments, &espImageSegment{
-			addr: uint32(section.Addr),
-			data: data,
-		})
-	}
-
-	// Sort the segments by address. This is what esptool does too.
-	sort.SliceStable(segments, func(i, j int) bool { return segments[i].addr < segments[j].addr })
-
-	// Calculate checksum over the segment data. This is used in the image
-	// footer.
-	checksum := uint8(0xef)
-	for _, segment := range segments {
-		for _, b := range segment.data {
-			checksum ^= b
-		}
-	}
-
-	// Write first to an in-memory buffer, primarily so that we can easily
-	// calculate a hash over the entire image.
-	// An added benefit is that we don't need to check for errors all the time.
-	outf := &bytes.Buffer{}
-
-	// Image header.
-	switch format {
-	case "esp32":
-		// Header format:
-		// https://github.com/espressif/esp-idf/blob/8fbb63c2/components/bootloader_support/include/esp_image_format.h#L58
-		binary.Write(outf, binary.LittleEndian, struct {
-			magic          uint8
-			segment_count  uint8
-			spi_mode       uint8
-			spi_speed_size uint8
-			entry_addr     uint32
-			wp_pin         uint8
-			spi_pin_drv    [3]uint8
-			reserved       [11]uint8
-			hash_appended  bool
-		}{
-			magic:          0xE9,
-			segment_count:  byte(len(segments)),
-			spi_mode:       0, // irrelevant, replaced by esptool when flashing
-			spi_speed_size: 0, // spi_speed, spi_size: replaced by esptool when flashing
-			entry_addr:     uint32(inf.Entry),
-			wp_pin:         0xEE, // disable WP pin
-			hash_appended:  true, // add a SHA256 hash
-		})
-	case "esp8266":
-		// Header format:
-		// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
-		// Basically a truncated version of the ESP32 header.
-		binary.Write(outf, binary.LittleEndian, struct {
-			magic          uint8
-			segment_count  uint8
-			spi_mode       uint8
-			spi_speed_size uint8
-			entry_addr     uint32
-		}{
-			magic:          0xE9,
-			segment_count:  byte(len(segments)),
-			spi_mode:       0,    // irrelevant, replaced by esptool when flashing
-			spi_speed_size: 0x20, // spi_speed, spi_size: replaced by esptool when flashing
-			entry_addr:     uint32(inf.Entry),
-		})
-	default:
-		return fmt.Errorf("builder: unknown binary format %#v, expected esp32 or esp8266", format)
-	}
-
-	// Write all segments to the image.
-	// https://github.com/espressif/esptool/wiki/Firmware-Image-Format#segment
-	for _, segment := range segments {
-		binary.Write(outf, binary.LittleEndian, struct {
-			addr   uint32
-			length uint32
-		}{
-			addr:   segment.addr,
-			length: uint32(len(segment.data)),
-		})
-		outf.Write(segment.data)
-	}
-
-	// Footer, including checksum.
-	// The entire image size must be a multiple of 16, so pad the image to one
-	// byte less than that before writing the checksum.
-	outf.Write(make([]byte, 15-outf.Len()%16))
-	outf.WriteByte(checksum)
-
-	if format == "esp32" {
-		// SHA256 hash (to protect against image corruption, not for security).
-		hash := sha256.Sum256(outf.Bytes())
-		outf.Write(hash[:])
-	}
-
-	// Write the image to the output file.
-	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
-}
@@ -1,173 +0,0 @@
-package builder
-
-// This file implements a job runner for the compiler, which runs jobs in
-// parallel while taking care of dependencies.
-
-import (
-	"fmt"
-	"runtime"
-	"time"
-)
-
-// Set to true to enable logging in the job runner. This may help to debug
-// concurrency or performance issues.
-const jobRunnerDebug = false
-
-type jobState uint8
-
-const (
-	jobStateQueued   jobState = iota // not yet running
-	jobStateRunning                  // running
-	jobStateFinished                 // finished running
-)
-
-// compileJob is a single compiler job, comparable to a single Makefile target.
-// It is used to orchestrate various compiler tasks that can be run in parallel
-// but that have dependencies and thus have limitations in how they can be run.
-type compileJob struct {
-	description  string // description, only used for logging
-	dependencies []*compileJob
-	result       string // result (path)
-	run          func(*compileJob) (err error)
-	state        jobState
-	err          error         // error if finished
-	duration     time.Duration // how long it took to run this job (only set after finishing)
-}
-
-// dummyCompileJob returns a new *compileJob that produces an output without
-// doing anything. This can be useful where a *compileJob producing an output is
-// expected but nothing needs to be done, for example for a load from a cache.
-func dummyCompileJob(result string) *compileJob {
-	return &compileJob{
-		description: "<dummy>",
-		result:      result,
-	}
-}
-
-// readyToRun returns whether this job is ready to run: it is itself not yet
-// started and all dependencies are finished.
-func (job *compileJob) readyToRun() bool {
-	if job.state != jobStateQueued {
-		// Already running or finished, so shouldn't be run again.
-		return false
-	}
-
-	// Check dependencies.
-	for _, dep := range job.dependencies {
-		if dep.state != jobStateFinished {
-			// A dependency is not finished, so this job has to wait until it
-			// is.
-			return false
-		}
-	}
-
-	// All conditions are satisfied.
-	return true
-}
-
-// runJobs runs all the jobs indicated in the jobs slice and returns the error
-// of the first job that fails to run.
-// It runs all jobs in the order of the slice, as long as all dependencies have
-// already run. Therefore, if some jobs are preferred to run before others, they
-// should be ordered as such in this slice.
-func runJobs(jobs []*compileJob) error {
-	// Create channels to communicate with the workers.
-	doneChan := make(chan *compileJob)
-	workerChan := make(chan *compileJob)
-	defer close(workerChan)
-
-	// Start a number of workers.
-	for i := 0; i < runtime.NumCPU(); i++ {
-		if jobRunnerDebug {
-			fmt.Println("## starting worker", i)
-		}
-		go jobWorker(workerChan, doneChan)
-	}
-
-	// Send each job in the jobs slice to a worker, taking care of job
-	// dependencies.
-	numRunningJobs := 0
-	var totalTime time.Duration
-	start := time.Now()
-	for {
-		// If there are free workers, try starting a new job (if one is
-		// available). If it succeeds, try again to fill the entire worker pool.
-		if numRunningJobs < runtime.NumCPU() {
-			jobToRun := nextJob(jobs)
-			if jobToRun != nil {
-				// Start job.
-				if jobRunnerDebug {
-					fmt.Println("## start:   ", jobToRun.description)
-				}
-				jobToRun.state = jobStateRunning
-				workerChan <- jobToRun
-				numRunningJobs++
-				continue
-			}
-		}
-
-		// When there are no jobs running, all jobs in the jobs slice must have
-		// been finished. Therefore, the work is done.
-		if numRunningJobs == 0 {
-			break
-		}
-
-		// Wait until a job is finished.
-		job := <-doneChan
-		job.state = jobStateFinished
-		numRunningJobs--
-		totalTime += job.duration
-		if jobRunnerDebug {
-			fmt.Println("## finished:", job.description, "(time "+job.duration.String()+")")
-		}
-		if job.err != nil {
-			// Wait for running jobs to finish.
-			for numRunningJobs != 0 {
-				<-doneChan
-				numRunningJobs--
-			}
-			// Return error of first failing job.
-			return job.err
-		}
-	}
-
-	// Some statistics, if debugging.
-	if jobRunnerDebug {
-		// Total duration of running all jobs.
-		duration := time.Since(start)
-		fmt.Println("## total:   ", duration)
-
-		// The individual time of each job combined. On a multicore system, this
-		// should be lower than the total above.
-		fmt.Println("## job sum: ", totalTime)
-	}
-
-	return nil
-}
-
-// nextJob returns the first ready-to-run job.
-// This is an implementation detail of runJobs.
-func nextJob(jobs []*compileJob) *compileJob {
-	for _, job := range jobs {
-		if job.readyToRun() {
-			return job
-		}
-	}
-	return nil
-}
-
-// jobWorker is the goroutine that runs received jobs.
-// This is an implementation detail of runJobs.
-func jobWorker(workerChan, doneChan chan *compileJob) {
-	for job := range workerChan {
-		start := time.Now()
-		if job.run != nil {
-			err := job.run(job)
-			if err != nil {
-				job.err = err
-			}
-		}
-		job.duration = time.Since(start)
-		doneChan <- job
-	}
-}
@@ -1,6 +1,7 @@
 package builder

 import (
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -39,111 +40,63 @@ func (l *Library) sourcePaths(target string) []string {
 }

 // Load the library archive, possibly generating and caching it if needed.
-// The resulting file is stored in the provided tmpdir, which is expected to be
-// removed after the Load call.
-func (l *Library) Load(target, tmpdir string) (path string, err error) {
-	job, err := l.load(target, "", tmpdir)
-	if err != nil {
-		return "", err
-	}
-	jobs := append([]*compileJob{job}, job.dependencies...)
-	err = runJobs(jobs)
-	return job.result, err
-}
-
-// load returns a compile job to build this library file for the given target
-// and CPU. It may return a dummy compileJob if the library build is already
-// cached. The path is stored as job.result but is only valid if the job and
-// job.dependencies have been run.
-// The provided tmpdir will be used to store intermediary files and possibly the
-// output archive file, it is expected to be removed after use.
-func (l *Library) load(target, cpu, tmpdir string) (job *compileJob, err error) {
+func (l *Library) Load(target string) (path string, err error) {
 	// Try to load a precompiled library.
 	precompiledPath := filepath.Join(goenv.Get("TINYGOROOT"), "pkg", target, l.name+".a")
 	if _, err := os.Stat(precompiledPath); err == nil {
 		// Found a precompiled library for this OS/architecture. Return the path
 		// directly.
-		return dummyCompileJob(precompiledPath), nil
+		return precompiledPath, nil
 	}

-	var outfile string
-	if cpu != "" {
-		outfile = l.name + "-" + target + "-" + cpu + ".a"
-	} else {
-		outfile = l.name + "-" + target + ".a"
-	}
+	outfile := l.name + "-" + target + ".a"

 	// Try to fetch this library from the cache.
-	if path, err := cacheLoad(outfile, l.sourcePaths(target)); path != "" || err != nil {
+	if path, err := cacheLoad(outfile, commands["clang"][0], l.sourcePaths(target)); path != "" || err != nil {
 		// Cache hit.
-		return dummyCompileJob(path), nil
+		return path, err
 	}
 	// Cache miss, build it now.

-	remapDir := filepath.Join(os.TempDir(), "tinygo-"+l.name)
-	dir := filepath.Join(tmpdir, "build-lib-"+l.name)
-	err = os.Mkdir(dir, 0777)
+	dirPrefix := "tinygo-" + l.name
+	remapDir := filepath.Join(os.TempDir(), dirPrefix)
+	dir, err := ioutil.TempDir(os.TempDir(), dirPrefix)
 	if err != nil {
-		return nil, err
+		return "", err
 	}
+	defer os.RemoveAll(dir)

 	// Precalculate the flags to the compiler invocation.
-	// 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.
 	args := append(l.cflags(), "-c", "-Oz", "-g", "-ffunction-sections", "-fdata-sections", "-Wno-macro-redefined", "--target="+target, "-fdebug-prefix-map="+dir+"="+remapDir)
-	if cpu != "" {
-		args = append(args, "-mcpu="+cpu)
-	}
 	if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
-		args = append(args, "-fshort-enums", "-fomit-frame-pointer", "-mfloat-abi=soft")
+		args = append(args, "-fshort-enums", "-fomit-frame-pointer")
 	}
 	if strings.HasPrefix(target, "riscv32-") {
 		args = append(args, "-march=rv32imac", "-mabi=ilp32", "-fforce-enable-int128")
 	}
-	if strings.HasPrefix(target, "riscv64-") {
-		args = append(args, "-march=rv64gc", "-mabi=lp64")
-	}

-	// Create job to put all the object files in a single archive. This archive
-	// file is the (static) library file.
+	// Compile all sources.
 	var objs []string
-	arpath := filepath.Join(dir, l.name+".a")
-	job = &compileJob{
-		description: "ar " + l.name + ".a",
-		result:      arpath,
-		run: func(*compileJob) error {
-			// Create an archive of all object files.
-			err := makeArchive(arpath, objs)
-			if err != nil {
-				return err
-			}
-			// Store this archive in the cache.
-			_, err = cacheStore(arpath, outfile, l.sourcePaths(target))
-			return err
-		},
-	}
-
-	// Create jobs to compile all sources. These jobs are depended upon by the
-	// archive job above, so must be run first.
 	for _, srcpath := range l.sourcePaths(target) {
-		srcpath := srcpath // avoid concurrency issues by redefining inside the loop
 		objpath := filepath.Join(dir, filepath.Base(srcpath)+".o")
 		objs = append(objs, objpath)
-		job.dependencies = append(job.dependencies, &compileJob{
-			description: "compile " + srcpath,
-			run: func(*compileJob) error {
-				var compileArgs []string
-				compileArgs = append(compileArgs, args...)
-				compileArgs = append(compileArgs, "-o", objpath, srcpath)
-				err := runCCompiler(compileArgs...)
-				if err != nil {
-					return &commandError{"failed to build", srcpath, err}
-				}
-				return nil
-			},
-		})
+		// 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.
+		err := runCCompiler("clang", append(args, "-o", objpath, srcpath)...)
+		if err != nil {
+			return "", &commandError{"failed to build", srcpath, err}
+		}
 	}

-	return job, nil
+	// Put all the object files in a single archive. This archive file will be
+	// used to statically link this library.
+	arpath := filepath.Join(dir, l.name+".a")
+	err = makeArchive(arpath, objs)
+	if err != nil {
+		return "", err
+	}
+
+	// Store this archive in the cache.
+	return cacheStore(arpath, outfile, commands["clang"][0], l.sourcePaths(target))
 }
@@ -4,15 +4,12 @@ import (
 	"debug/elf"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"sort"

 	"github.com/marcinbor85/gohex"
 )

-// maxPadBytes is the maximum allowed bytes to be padded in a rom extraction
-// this value is currently defined by Nintendo Switch Page Alignment (4096 bytes)
-const maxPadBytes = 4095
-
 // objcopyError is an error returned by functions that act like objcopy.
 type objcopyError struct {
 	Op  string
@@ -61,7 +58,7 @@ func extractROM(path string) (uint64, []byte, error) {

 	progs := make(progSlice, 0, 2)
 	for _, prog := range f.Progs {
-		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 || prog.Off == 0 {
+		if prog.Type != elf.PT_LOAD || prog.Filesz == 0 {
 			continue
 		}
 		progs = append(progs, prog)
@@ -73,19 +70,8 @@ func extractROM(path string) (uint64, []byte, error) {

 	var rom []byte
 	for _, prog := range progs {
-		romEnd := progs[0].Paddr + uint64(len(rom))
-		if prog.Paddr > romEnd && prog.Paddr < romEnd+16 {
-			// Sometimes, the linker seems to insert a bit of padding between
-			// segments. Simply zero-fill these parts.
-			rom = append(rom, make([]byte, prog.Paddr-romEnd)...)
-		}
 		if prog.Paddr != progs[0].Paddr+uint64(len(rom)) {
-			diff := prog.Paddr - (progs[0].Paddr + uint64(len(rom)))
-			if diff > maxPadBytes {
-				return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
-			}
-			// Pad the difference
-			rom = append(rom, make([]byte, diff)...)
+			return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
 		}
 		data, err := ioutil.ReadAll(prog.Open())
 		if err != nil {
@@ -107,7 +93,7 @@ func extractROM(path string) (uint64, []byte, error) {

 // 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, binaryFormat string) error {
+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
@@ -121,20 +107,24 @@ func objcopy(infile, outfile, binaryFormat string) error {
 	}

 	// Write to the file, in the correct format.
-	switch binaryFormat {
-	case "hex":
-		// Intel hex file, includes the firmware start address.
+	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}
 		}
-		return mem.DumpIntelHex(f, 16)
-	case "bin":
-		// The start address is not stored in raw firmware files (therefore you
-		// should use .hex files in most cases).
-		_, err := f.Write(data)
-		return err
+		mem.DumpIntelHex(f, 16) // TODO: handle error
+		return nil
 	default:
 		panic("unreachable")
 	}
@@ -9,8 +9,8 @@ import (
 )

 // runCCompiler invokes a C compiler with the given arguments.
-func runCCompiler(flags ...string) error {
-	if hasBuiltinTools {
+func runCCompiler(command string, flags ...string) error {
+	if hasBuiltinTools && command == "clang" {
 		// Compile this with the internal Clang compiler.
 		headerPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
 		if headerPath == "" {
@@ -23,8 +23,17 @@ func runCCompiler(flags ...string) error {
 		return cmd.Run()
 	}

-	// Compile this with an external invocation of the Clang compiler.
-	return execCommand(commands["clang"], flags...)
+	// 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()
 }

 // link invokes a linker with the given name and flags.
@@ -41,9 +41,6 @@ type cgoPackage struct {
 	elaboratedTypes map[string]*elaboratedTypeInfo
 	enums           map[string]enumInfo
 	anonStructNum   int
-	cflags          []string // CFlags from #cgo lines
-	ldflags         []string // LDFlags from #cgo lines
-	visitedFiles    map[string][]byte
 }

 // constantInfo stores some information about a CGo constant found by libclang
@@ -56,10 +53,9 @@ type constantInfo struct {
 // functionInfo stores some information about a CGo function found by libclang
 // and declared in the AST.
 type functionInfo struct {
-	args     []paramInfo
-	results  *ast.FieldList
-	pos      token.Pos
-	variadic bool
+	args    []paramInfo
+	results *ast.FieldList
+	pos     token.Pos
 }

 // paramInfo is a parameter of a CGo function (see functionInfo).
@@ -158,10 +154,9 @@ typedef unsigned long long  _Cgo_ulonglong;
 // Process extracts `import "C"` statements from the AST, parses the comment
 // with libclang, and modifies the AST to use this information. It returns a
 // newly created *ast.File that should be added to the list of to-be-parsed
-// files, the CFLAGS and LDFLAGS found in #cgo lines, and a map of file hashes
-// of the accessed C header files. If there is one or more error, it returns
-// these in the []error slice but still modifies the AST.
-func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string) (*ast.File, []string, []string, map[string][]byte, []error) {
+// files. If there is one or more error, it returns these in the []error slice
+// but still modifies the AST.
+func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string) (*ast.File, []error) {
 	p := &cgoPackage{
 		dir:             dir,
 		fset:            fset,
@@ -173,9 +168,13 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 		typedefs:        map[string]*typedefInfo{},
 		elaboratedTypes: map[string]*elaboratedTypeInfo{},
 		enums:           map[string]enumInfo{},
-		visitedFiles:    map[string][]byte{},
 	}

+	// Disable _FORTIFY_SOURCE as it causes problems on macOS.
+	// Note that it is only disabled for memcpy (etc) calls made from Go, which
+	// have better alternatives anyway.
+	cflags = append(cflags, "-D_FORTIFY_SOURCE=0")
+
 	// Add a new location for the following file.
 	generatedTokenPos := p.fset.AddFile(dir+"/!cgo.go", -1, 0)
 	generatedTokenPos.SetLines([]int{0})
@@ -184,7 +183,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// Find the absolute path for this package.
 	packagePath, err := filepath.Abs(fset.File(files[0].Pos()).Name())
 	if err != nil {
-		return nil, nil, nil, nil, []error{
+		return nil, []error{
 			scanner.Error{
 				Pos: fset.Position(files[0].Pos()),
 				Msg: "cgo: cannot find absolute path: " + err.Error(), // TODO: wrap this error
@@ -359,20 +358,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 						continue
 					}
 					makePathsAbsolute(flags, packagePath)
-					p.cflags = append(p.cflags, flags...)
-				case "LDFLAGS":
-					flags, err := shlex.Split(value)
-					if err != nil {
-						// TODO: find the exact location where the error happened.
-						p.addErrorAfter(comment.Slash, comment.Text[:lineStart+colon+1], "failed to parse flags in #cgo line: "+err.Error())
-						continue
-					}
-					if err := checkLinkerFlags(name, flags); err != nil {
-						p.addErrorAfter(comment.Slash, comment.Text[:lineStart+colon+1], err.Error())
-						continue
-					}
-					makePathsAbsolute(flags, packagePath)
-					p.ldflags = append(p.ldflags, flags...)
+					cflags = append(cflags, flags...)
 				default:
 					startPos := strings.LastIndex(line[4:colon], name) + 4
 					p.addErrorAfter(comment.Slash, comment.Text[:lineStart+startPos], "invalid #cgo line: "+name)
@@ -382,13 +368,6 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 		}
 	}

-	// Define CFlags that will be used while parsing the package.
-	// Disable _FORTIFY_SOURCE as it causes problems on macOS.
-	// Note that it is only disabled for memcpy (etc) calls made from Go, which
-	// have better alternatives anyway.
-	cflagsForCGo := append([]string{"-D_FORTIFY_SOURCE=0"}, cflags...)
-	cflagsForCGo = append(cflagsForCGo, p.cflags...)
-
 	// Process all CGo imports.
 	for _, genDecl := range statements {
 		cgoComment := genDecl.Doc.Text()
@@ -398,7 +377,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 			pos = genDecl.Doc.Pos()
 		}
 		position := fset.PositionFor(pos, true)
-		p.parseFragment(cgoComment+cgoTypes, cflagsForCGo, position.Filename, position.Line)
+		p.parseFragment(cgoComment+cgoTypes, cflags, position.Filename, position.Line)
 	}

 	// Declare functions found by libclang.
@@ -433,7 +412,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// Print the newly generated in-memory AST, for debugging.
 	//ast.Print(fset, p.generated)

-	return p.generated, p.cflags, p.ldflags, p.visitedFiles, p.errors
+	return p.generated, p.errors
 }

 // makePathsAbsolute converts some common path compiler flags (-I, -L) from
@@ -491,16 +470,6 @@ func (p *cgoPackage) addFuncDecls() {
 				Results: fn.results,
 			},
 		}
-		if fn.variadic {
-			decl.Doc = &ast.CommentGroup{
-				List: []*ast.Comment{
-					&ast.Comment{
-						Slash: fn.pos,
-						Text:  "//go:variadic",
-					},
-				},
-			}
-		}
 		obj.Decl = decl
 		for i, arg := range fn.args {
 			args[i] = &ast.Field{
@@ -5,7 +5,6 @@ import (
 	"flag"
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/format"
 	"go/parser"
 	"go/token"
@@ -24,7 +23,7 @@ var flagUpdate = flag.Bool("update", false, "Update images based on test output.
 // normalizeResult normalizes Go source code that comes out of tests across
 // platforms and Go versions.
 func normalizeResult(result string) string {
-	actual := strings.ReplaceAll(result, "\r\n", "\n")
+	actual := strings.Replace(result, "\r\n", "\n", -1)

 	// Make sure all functions are wrapped, even those that would otherwise be
 	// single-line functions. This is necessary because Go 1.14 changed the way
@@ -42,20 +41,6 @@ func TestCGo(t *testing.T) {
 	for _, name := range []string{"basic", "errors", "types", "flags", "const"} {
 		name := name // avoid a race condition
 		t.Run(name, func(t *testing.T) {
-			// Skip tests that require specific Go version.
-			if name == "errors" {
-				ok := false
-				for _, version := range build.Default.ReleaseTags {
-					if version == "go1.16" {
-						ok = true
-						break
-					}
-				}
-				if !ok {
-					t.Skip("Results for errors test are only valid for Go 1.16+")
-				}
-			}
-
 			// Read the AST in memory.
 			path := filepath.Join("testdata", name+".go")
 			fset := token.NewFileSet()
@@ -65,7 +50,7 @@ func TestCGo(t *testing.T) {
 			}

 			// Process the AST with CGo.
-			cgoAST, _, _, _, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)
+			cgoAST, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)

 			// Check the AST for type errors.
 			var typecheckErrors []error
@@ -113,7 +98,7 @@ func TestCGo(t *testing.T) {
 			if err != nil {
 				t.Fatalf("could not read expected output: %v", err)
 			}
-			expected := strings.ReplaceAll(string(expectedBytes), "\r\n", "\n")
+			expected := strings.Replace(string(expectedBytes), "\r\n", "\n", -1)

 			// Check whether the output is as expected.
 			if expected != actual {
@@ -154,7 +139,7 @@ func formatDiagnostic(err error) string {
 	msg := err.Error()
 	if runtime.GOOS == "windows" {
 		// Fix Windows path slashes.
-		msg = strings.ReplaceAll(msg, "testdata\\", "testdata/")
+		msg = strings.Replace(msg, "testdata\\", "testdata/", -1)
 	}
 	return "//     " + msg + "\n"
 }
@@ -4,7 +4,6 @@ package cgo
 // modification. It does not touch the AST itself.

 import (
-	"crypto/sha512"
 	"fmt"
 	"go/ast"
 	"go/scanner"
@@ -57,7 +56,6 @@ 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);
-void tinygo_clang_inclusion_visitor(CXFile included_file, CXSourceLocation *inclusion_stack, unsigned include_len, CXClientData client_data);
 */
 import "C"

@@ -116,7 +114,6 @@ func (p *cgoPackage) parseFragment(fragment string, cflags []string, posFilename
 	}
 	defer C.clang_disposeTranslationUnit(unit)

-	// Report parser and type errors.
 	if numDiagnostics := int(C.clang_getNumDiagnostics(unit)); numDiagnostics != 0 {
 		addDiagnostic := func(diagnostic C.CXDiagnostic) {
 			spelling := getString(C.clang_getDiagnosticSpelling(diagnostic))
@@ -137,36 +134,10 @@ func (p *cgoPackage) parseFragment(fragment string, cflags []string, posFilename
 		}
 	}

-	// Extract information required by CGo.
 	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))
-
-	// Determine files read during CGo processing, for caching.
-	inclusionCallback := func(includedFile C.CXFile) {
-		// Get full file path.
-		path := getString(C.clang_getFileName(includedFile))
-
-		// Get contents of file (that should be in-memory).
-		size := C.size_t(0)
-		rawData := C.clang_getFileContents(unit, includedFile, &size)
-		if rawData == nil {
-			// Sanity check. This should (hopefully) never trigger.
-			panic("libclang: file contents was not loaded")
-		}
-		data := (*[1 << 24]byte)(unsafe.Pointer(rawData))[:size]
-
-		// Hash the contents if it isn't hashed yet.
-		if _, ok := p.visitedFiles[path]; !ok {
-			// already stored
-			sum := sha512.Sum512_224(data)
-			p.visitedFiles[path] = sum[:]
-		}
-	}
-	inclusionCallbackRef := storedRefs.Put(inclusionCallback)
-	defer storedRefs.Remove(inclusionCallbackRef)
-	C.clang_getInclusions(unit, C.CXInclusionVisitor(C.tinygo_clang_inclusion_visitor), C.CXClientData(inclusionCallbackRef))
 }

 //export tinygo_clang_globals_visitor
@@ -181,10 +152,12 @@ func tinygo_clang_globals_visitor(c, parent C.GoCXCursor, client_data C.CXClient
 			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,
-			variadic: C.clang_isFunctionTypeVariadic(cursorType) != 0,
+			pos: pos,
 		}
 		p.functions[name] = fn
 		for i := 0; i < numArgs; i++ {
@@ -273,9 +246,9 @@ func tinygo_clang_globals_visitor(c, parent C.GoCXCursor, client_data C.CXClient
 		}
 		value := source[len(name):]
 		// Try to convert this #define into a Go constant expression.
-		expr, scannerError := parseConst(pos+token.Pos(len(name)), p.fset, value)
-		if scannerError != nil {
-			p.errors = append(p.errors, *scannerError)
+		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.
@@ -801,9 +774,3 @@ func tinygo_clang_enum_visitor(c, parent C.GoCXCursor, client_data C.CXClientDat
 	}
 	return C.CXChildVisit_Continue
 }
-
-//export tinygo_clang_inclusion_visitor
-func tinygo_clang_inclusion_visitor(includedFile C.CXFile, inclusionStack *C.CXSourceLocation, includeLen C.unsigned, clientData C.CXClientData) {
-	callback := storedRefs.Get(unsafe.Pointer(clientData)).(func(C.CXFile))
-	callback(includedFile)
-}
@@ -1,14 +1,14 @@
 // +build !byollvm
-// +build !llvm10
+// +build !llvm9

 package cgo

 /*
-#cgo linux   CFLAGS:  -I/usr/lib/llvm-11/include
-#cgo darwin  CFLAGS:  -I/usr/local/opt/llvm@11/include
-#cgo freebsd CFLAGS:  -I/usr/local/llvm11/include
-#cgo linux   LDFLAGS: -L/usr/lib/llvm-11/lib -lclang
-#cgo darwin  LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
-#cgo freebsd LDFLAGS: -L/usr/local/llvm11/lib -lclang
+#cgo linux  CFLAGS: -I/usr/lib/llvm-10/include
+#cgo darwin CFLAGS: -I/usr/local/opt/llvm@10/include
+#cgo freebsd CFLAGS: -I/usr/local/llvm10/include
+#cgo linux  LDFLAGS: -L/usr/lib/llvm-10/lib -lclang
+#cgo darwin LDFLAGS: -L/usr/local/opt/llvm@10/lib -lclang -lffi
+#cgo freebsd LDFLAGS: -L/usr/local/llvm10/lib -lclang
 */
 import "C"
@@ -1,14 +0,0 @@
-// +build !byollvm
-// +build llvm10
-
-package cgo
-
-/*
-#cgo linux  CFLAGS: -I/usr/lib/llvm-10/include
-#cgo darwin CFLAGS: -I/usr/local/opt/llvm@10/include
-#cgo freebsd CFLAGS: -I/usr/local/llvm10/include
-#cgo linux  LDFLAGS: -L/usr/lib/llvm-10/lib -lclang
-#cgo darwin LDFLAGS: -L/usr/local/opt/llvm@10/lib -lclang -lffi
-#cgo freebsd LDFLAGS: -L/usr/local/llvm10/lib -lclang
-*/
-import "C"
@@ -0,0 +1,14 @@
+// +build !byollvm
+// +build llvm9
+
+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/llvm9/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/llvm9/lib -lclang
+*/
+import "C"
@@ -4,10 +4,10 @@
 //     testdata/errors.go:13:23: unexpected token )

 // Type checking errors after CGo processing:
-//     testdata/errors.go:102: cannot use 2 << 10 (untyped int constant 2048) as uint8 value in variable declaration (overflows)
+//     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: cannot use C.SOME_CONST_3 (untyped int constant 1234) as byte value in variable declaration (overflows)
+//     testdata/errors.go:110: C.SOME_CONST_3 (untyped int constant 1234) overflows byte

 package main

@@ -21,13 +21,6 @@ package main
 #if defined(NOTDEFINED)
 #warning flag must not be defined
 #endif
-
-// Check Compiler flags
-#cgo LDFLAGS: -lc
-
-// This flag is not valid ldflags
-#cgo LDFLAGS: -does-not-exists
-
 */
 import "C"

@@ -1,7 +1,6 @@
 // CGo errors:
 //     testdata/flags.go:5:7: invalid #cgo line: NOFLAGS
 //     testdata/flags.go:8:13: invalid flag: -fdoes-not-exist
-//     testdata/flags.go:29:14: invalid flag: -does-not-exists

 package main

@@ -104,10 +104,6 @@ typedef struct {
 	unsigned char e : 3;
 	// Note that C++ allows bitfields bigger than the underlying type.
 } bitfield_t;
-
-// Function signatures.
-void variadic0();
-void variadic2(int x, int y, ...);
 */
 import "C"

@@ -167,9 +163,3 @@ func accessUnion() {
 	var _ *C.int = union2d.unionfield_i()
 	var _ *[2]float64 = union2d.unionfield_d()
 }
-
-// Test function signatures.
-func accessFunctions() {
-	C.variadic0()
-	C.variadic2(3, 5)
-}
@@ -4,11 +4,6 @@ import "unsafe"

 var _ unsafe.Pointer

-func C.variadic0() //go:variadic
-func C.variadic2(x C.int, y C.int) //go:variadic
-var C.variadic0$funcaddr unsafe.Pointer
-var C.variadic2$funcaddr unsafe.Pointer
-
 const C.option2A = 20
 const C.optionA = 0
 const C.optionB = 1
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"path/filepath"
 	"regexp"
+	"strconv"
 	"strings"

 	"github.com/tinygo-org/tinygo/goenv"
@@ -21,6 +22,29 @@ type Config struct {
 	TestConfig     TestConfig
 }

+// FuncValueImplementation is an enum for the particular implementations of Go
+// func values.
+type FuncValueImplementation int
+
+// These constants describe the various possible implementations of Go func
+// values.
+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
+)
+
 // Triple returns the LLVM target triple, like armv6m-none-eabi.
 func (c *Config) Triple() string {
 	return c.Target.Triple
@@ -80,7 +104,12 @@ func (c *Config) GC() string {
 	if c.Target.GC != "" {
 		return c.Target.GC
 	}
-	return "conservative"
+	for _, tag := range c.Target.BuildTags {
+		if tag == "baremetal" || tag == "wasm" {
+			return "conservative"
+		}
+	}
+	return "extalloc"
 }

 // NeedsStackObjects returns true if the compiler should insert stack objects
@@ -89,19 +118,19 @@ func (c *Config) NeedsStackObjects() bool {
 	switch c.GC() {
 	case "conservative", "extalloc":
 		for _, tag := range c.BuildTags() {
-			if tag == "wasm" {
-				return true
+			if tag == "baremetal" {
+				return false
 			}
 		}

-		return false
+		return true
 	default:
 		return false
 	}
 }

-// Scheduler returns the scheduler implementation. Valid values are "none",
-//"coroutines" and "tasks".
+// Scheduler returns the scheduler implementation. Valid values are "coroutines"
+// and "tasks".
 func (c *Config) Scheduler() string {
 	if c.Options.Scheduler != "" {
 		return c.Options.Scheduler
@@ -113,47 +142,16 @@ func (c *Config) Scheduler() string {
 	return "coroutines"
 }

-// OptLevels returns the optimization level (0-2), size level (0-2), and inliner
-// threshold as used in the LLVM optimization pipeline.
-func (c *Config) OptLevels() (optLevel, sizeLevel int, inlinerThreshold uint) {
-	switch c.Options.Opt {
-	case "none", "0":
-		return 0, 0, 0 // -O0
-	case "1":
-		return 1, 0, 0 // -O1
-	case "2":
-		return 2, 0, 225 // -O2
-	case "s":
-		return 2, 1, 225 // -Os
-	case "z":
-		return 2, 2, 5 // -Oz, default
-	default:
-		// This is not shown to the user: valid choices are already checked as
-		// part of Options.Verify(). It is here as a sanity check.
-		panic("unknown optimization level: -opt=" + c.Options.Opt)
-	}
-}
-
 // FuncImplementation picks an appropriate func value implementation for the
 // target.
-func (c *Config) FuncImplementation() string {
+func (c *Config) 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 "tasks":
-		// 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.
-		return "doubleword"
 	case "none", "coroutines":
-		// As "doubleword", 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.
-		// Pick the switch implementation with the coroutines scheduler, as it
-		// allows the use of blocking inside a function that is used as a func
-		// value.
-		return "switch"
+		return FuncValueSwitch
+	case "tasks":
+		return FuncValueDoubleword
 	default:
 		panic("unknown scheduler type")
 	}
@@ -166,31 +164,18 @@ func (c *Config) PanicStrategy() string {
 	return c.Options.PanicStrategy
 }

-// AutomaticStackSize returns whether goroutine stack sizes should be determined
-// automatically at compile time, if possible. If it is false, no attempt is
-// made.
-func (c *Config) AutomaticStackSize() bool {
-	if c.Target.AutoStackSize != nil && c.Scheduler() == "tasks" {
-		return *c.Target.AutoStackSize
-	}
-	return false
-}
-
 // CFlags returns the flags to pass to the C compiler. This is necessary for CGo
 // preprocessing.
 func (c *Config) CFlags() []string {
-	var cflags []string
+	cflags := append([]string{}, c.Options.CFlags...)
 	for _, flag := range c.Target.CFlags {
-		cflags = append(cflags, strings.ReplaceAll(flag, "{root}", goenv.Get("TINYGOROOT")))
+		cflags = append(cflags, strings.Replace(flag, "{root}", goenv.Get("TINYGOROOT"), -1))
 	}
 	if c.Target.Libc == "picolibc" {
 		root := goenv.Get("TINYGOROOT")
 		cflags = append(cflags, "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", filepath.Join(root, "lib", "picolibc", "newlib", "libc", "include"))
 		cflags = append(cflags, "-I"+filepath.Join(root, "lib/picolibc-include"))
 	}
-	if c.Debug() {
-		cflags = append(cflags, "-g")
-	}
 	return cflags
 }

@@ -200,11 +185,17 @@ func (c *Config) CFlags() []string {
 func (c *Config) LDFlags() []string {
 	root := goenv.Get("TINYGOROOT")
 	// Merge and adjust LDFlags.
-	var ldflags []string
+	ldflags := append([]string{}, c.Options.LDFlags...)
 	for _, flag := range c.Target.LDFlags {
-		ldflags = append(ldflags, strings.ReplaceAll(flag, "{root}", root))
+		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)
 	}
@@ -235,31 +226,6 @@ func (c *Config) Debug() bool {
 	return c.Options.Debug
 }

-// BinaryFormat returns an appropriate binary format, based on the file
-// extension and the configured binary format in the target JSON file.
-func (c *Config) BinaryFormat(ext string) string {
-	switch ext {
-	case ".bin", ".gba", ".nro":
-		// The simplest format possible: dump everything in a raw binary file.
-		if c.Target.BinaryFormat != "" {
-			return c.Target.BinaryFormat
-		}
-		return "bin"
-	case ".hex":
-		// Similar to bin, but includes the start address and is thus usually a
-		// better format.
-		return "hex"
-	case ".uf2":
-		// Special purpose firmware format, mainly used on Adafruit boards.
-		// More information:
-		// https://github.com/Microsoft/uf2
-		return "uf2"
-	default:
-		// Use the ELF format for unrecognized file formats.
-		return "elf"
-	}
-}
-
 // 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.
@@ -299,9 +265,6 @@ func (c *Config) OpenOCDConfiguration() (args []string, err error) {
 		return nil, fmt.Errorf("unknown OpenOCD transport: %#v", c.Target.OpenOCDTransport)
 	}
 	args = []string{"-f", "interface/" + openocdInterface + ".cfg"}
-	for _, cmd := range c.Target.OpenOCDCommands {
-		args = append(args, "-c", cmd)
-	}
 	if c.Target.OpenOCDTransport != "" {
 		args = append(args, "-c", "transport select "+c.Target.OpenOCDTransport)
 	}
@@ -309,38 +272,6 @@ func (c *Config) OpenOCDConfiguration() (args []string, err error) {
 	return args, nil
 }

-// CodeModel returns the code model used on this platform.
-func (c *Config) CodeModel() string {
-	if c.Target.CodeModel != "" {
-		return c.Target.CodeModel
-	}
-
-	return "default"
-}
-
-// RelocationModel returns the relocation model in use on this platform. Valid
-// values are "static", "pic", "dynamicnopic".
-func (c *Config) RelocationModel() string {
-	if c.Target.RelocationModel != "" {
-		return c.Target.RelocationModel
-	}
-
-	return "static"
-}
-
-// WasmAbi returns the WASM ABI which is specified in the target JSON file, and
-// the value is overridden by `-wasm-abi` flag if it is provided
-func (c *Config) WasmAbi() string {
-	if c.Options.WasmAbi != "" {
-		return c.Options.WasmAbi
-	}
-	return c.Target.WasmAbi
-}
-
-func (c *Config) LLVMFeatures() string {
-	return c.Options.LLVMFeatures
-}
-
 type TestConfig struct {
 	CompileTestBinary bool
 	// TODO: Filter the test functions to run, include verbose flag, etc
@@ -1,96 +1,23 @@
 package compileopts

-import (
-	"fmt"
-	"regexp"
-	"strings"
-)
-
-var (
-	validGCOptions            = []string{"none", "leaking", "extalloc", "conservative"}
-	validSchedulerOptions     = []string{"none", "tasks", "coroutines"}
-	validPrintSizeOptions     = []string{"none", "short", "full"}
-	validPanicStrategyOptions = []string{"print", "trap"}
-	validOptOptions           = []string{"none", "0", "1", "2", "s", "z"}
-)
-
 // 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
-	PrintCommands   bool
-	Debug           bool
-	PrintSizes      string
-	PrintAllocs     *regexp.Regexp // regexp string
-	PrintStacks     bool
-	Tags            string
-	WasmAbi         string
-	GlobalValues    map[string]map[string]string // map[pkgpath]map[varname]value
-	TestConfig      TestConfig
-	Programmer      string
-	OpenOCDCommands []string
-	LLVMFeatures    string
-}
-
-// Verify performs a validation on the given options, raising an error if options are not valid.
-func (o *Options) Verify() error {
-	if o.GC != "" {
-		valid := isInArray(validGCOptions, o.GC)
-		if !valid {
-			return fmt.Errorf(`invalid gc option '%s': valid values are %s`,
-				o.GC,
-				strings.Join(validGCOptions, ", "))
-		}
-	}
-
-	if o.Scheduler != "" {
-		valid := isInArray(validSchedulerOptions, o.Scheduler)
-		if !valid {
-			return fmt.Errorf(`invalid scheduler option '%s': valid values are %s`,
-				o.Scheduler,
-				strings.Join(validSchedulerOptions, ", "))
-		}
-	}
-
-	if o.PrintSizes != "" {
-		valid := isInArray(validPrintSizeOptions, o.PrintSizes)
-		if !valid {
-			return fmt.Errorf(`invalid size option '%s': valid values are %s`,
-				o.PrintSizes,
-				strings.Join(validPrintSizeOptions, ", "))
-		}
-	}
-
-	if o.PanicStrategy != "" {
-		valid := isInArray(validPanicStrategyOptions, o.PanicStrategy)
-		if !valid {
-			return fmt.Errorf(`invalid panic option '%s': valid values are %s`,
-				o.PanicStrategy,
-				strings.Join(validPanicStrategyOptions, ", "))
-		}
-	}
-
-	if o.Opt != "" {
-		if !isInArray(validOptOptions, o.Opt) {
-			return fmt.Errorf("invalid -opt=%s: valid values are %s", o.Opt, strings.Join(validOptOptions, ", "))
-		}
-	}
-
-	return nil
-}
-
-func isInArray(arr []string, item string) bool {
-	for _, i := range arr {
-		if i == item {
-			return true
-		}
-	}
-	return false
+	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
 }
@@ -1,138 +0,0 @@
-package compileopts_test
-
-import (
-	"errors"
-	"testing"
-
-	"github.com/tinygo-org/tinygo/compileopts"
-)
-
-func TestVerifyOptions(t *testing.T) {
-
-	expectedGCError := errors.New(`invalid gc option 'incorrect': valid values are none, leaking, extalloc, conservative`)
-	expectedSchedulerError := errors.New(`invalid scheduler option 'incorrect': valid values are none, tasks, coroutines`)
-	expectedPrintSizeError := errors.New(`invalid size option 'incorrect': valid values are none, short, full`)
-	expectedPanicStrategyError := errors.New(`invalid panic option 'incorrect': valid values are print, trap`)
-
-	testCases := []struct {
-		name          string
-		opts          compileopts.Options
-		expectedError error
-	}{
-		{
-			name: "OptionsEmpty",
-			opts: compileopts.Options{},
-		},
-		{
-			name: "InvalidGCOption",
-			opts: compileopts.Options{
-				GC: "incorrect",
-			},
-			expectedError: expectedGCError,
-		},
-		{
-			name: "GCOptionNone",
-			opts: compileopts.Options{
-				GC: "none",
-			},
-		},
-		{
-			name: "GCOptionLeaking",
-			opts: compileopts.Options{
-				GC: "leaking",
-			},
-		},
-		{
-			name: "GCOptionExtalloc",
-			opts: compileopts.Options{
-				GC: "extalloc",
-			},
-		},
-		{
-			name: "GCOptionConservative",
-			opts: compileopts.Options{
-				GC: "conservative",
-			},
-		},
-		{
-			name: "InvalidSchedulerOption",
-			opts: compileopts.Options{
-				Scheduler: "incorrect",
-			},
-			expectedError: expectedSchedulerError,
-		},
-		{
-			name: "SchedulerOptionNone",
-			opts: compileopts.Options{
-				Scheduler: "none",
-			},
-		},
-		{
-			name: "SchedulerOptionTasks",
-			opts: compileopts.Options{
-				Scheduler: "tasks",
-			},
-		},
-		{
-			name: "SchedulerOptionCoroutines",
-			opts: compileopts.Options{
-				Scheduler: "coroutines",
-			},
-		},
-		{
-			name: "InvalidPrintSizeOption",
-			opts: compileopts.Options{
-				PrintSizes: "incorrect",
-			},
-			expectedError: expectedPrintSizeError,
-		},
-		{
-			name: "PrintSizeOptionNone",
-			opts: compileopts.Options{
-				PrintSizes: "none",
-			},
-		},
-		{
-			name: "PrintSizeOptionShort",
-			opts: compileopts.Options{
-				PrintSizes: "short",
-			},
-		},
-		{
-			name: "PrintSizeOptionFull",
-			opts: compileopts.Options{
-				PrintSizes: "full",
-			},
-		},
-		{
-			name: "InvalidPanicOption",
-			opts: compileopts.Options{
-				PanicStrategy: "incorrect",
-			},
-			expectedError: expectedPanicStrategyError,
-		},
-		{
-			name: "PanicOptionPrint",
-			opts: compileopts.Options{
-				PanicStrategy: "print",
-			},
-		},
-		{
-			name: "PanicOptionTrap",
-			opts: compileopts.Options{
-				PanicStrategy: "trap",
-			},
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			err := tc.opts.Verify()
-			if tc.expectedError != err {
-				if tc.expectedError.Error() != err.Error() {
-					t.Errorf("expected %v, got %v", tc.expectedError, err)
-				}
-			}
-		})
-	}
-}
@@ -7,9 +7,7 @@ import (
 	"errors"
 	"io"
 	"os"
-	"os/exec"
 	"path/filepath"
-	"reflect"
 	"runtime"
 	"strings"

@@ -31,74 +29,106 @@ type TargetSpec struct {
 	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)
 	Libc             string   `json:"libc"`
-	AutoStackSize    *bool    `json:"automatic-stack-size"` // Determine stack size automatically at compile time.
-	DefaultStackSize uint64   `json:"default-stack-size"`   // Default stack size if the size couldn't be determined at compile time.
 	CFlags           []string `json:"cflags"`
 	LDFlags          []string `json:"ldflags"`
 	LinkerScript     string   `json:"linkerscript"`
 	ExtraFiles       []string `json:"extra-files"`
-	Emulator         []string `json:"emulator" override:"copy"` // inherited Emulator must not be append
+	Emulator         []string `json:"emulator"`
 	FlashCommand     string   `json:"flash-command"`
-	GDB              []string `json:"gdb"`
+	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"`
-	BinaryFormat     string   `json:"binary-format"`
 	OpenOCDInterface string   `json:"openocd-interface"`
 	OpenOCDTarget    string   `json:"openocd-target"`
 	OpenOCDTransport string   `json:"openocd-transport"`
-	OpenOCDCommands  []string `json:"openocd-commands"`
 	JLinkDevice      string   `json:"jlink-device"`
-	CodeModel        string   `json:"code-model"`
-	RelocationModel  string   `json:"relocation-model"`
-	WasmAbi          string   `json:"wasm-abi"`
 }

-// overrideProperties overrides all properties that are set in child into itself using reflection.
-func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
-	specType := reflect.TypeOf(spec).Elem()
-	specValue := reflect.ValueOf(spec).Elem()
-	childValue := reflect.ValueOf(child).Elem()
-
-	for i := 0; i < specType.NumField(); i++ {
-		field := specType.Field(i)
-		src := childValue.Field(i)
-		dst := specValue.Field(i)
-
-		switch kind := field.Type.Kind(); kind {
-		case reflect.String: // for strings, just copy the field of child to spec if not empty
-			if src.Len() > 0 {
-				dst.Set(src)
-			}
-		case reflect.Uint, reflect.Uint32, reflect.Uint64: // for Uint, copy if not zero
-			if src.Uint() != 0 {
-				dst.Set(src)
-			}
-		case reflect.Ptr: // for pointers, copy if not nil
-			if !src.IsNil() {
-				dst.Set(src)
-			}
-		case reflect.Slice: // for slices...
-			if src.Len() > 0 { // ... if not empty ...
-				switch tag := field.Tag.Get("override"); tag {
-				case "copy":
-					// copy the field of child to spec
-					dst.Set(src)
-				case "append", "":
-					// or append the field of child to spec
-					dst.Set(reflect.AppendSlice(src, dst))
-				default:
-					panic("override mode must be 'copy' or 'append' (default). I don't know how to '" + tag + "'.")
-				}
-			}
-		default:
-			panic("unknown field type : " + kind.String())
-		}
+// copyProperties copies all properties that are set in spec2 into itself.
+func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
+	// TODO: simplify this using reflection? Inherits and BuildTags are special
+	// cases, but the rest can simply be copied if set.
+	spec.Inherits = append(spec.Inherits, spec2.Inherits...)
+	if spec2.Triple != "" {
+		spec.Triple = spec2.Triple
+	}
+	if spec2.CPU != "" {
+		spec.CPU = spec2.CPU
+	}
+	spec.Features = append(spec.Features, spec2.Features...)
+	if spec2.GOOS != "" {
+		spec.GOOS = spec2.GOOS
+	}
+	if spec2.GOARCH != "" {
+		spec.GOARCH = spec2.GOARCH
+	}
+	spec.BuildTags = append(spec.BuildTags, spec2.BuildTags...)
+	if spec2.GC != "" {
+		spec.GC = spec2.GC
+	}
+	if spec2.Scheduler != "" {
+		spec.Scheduler = spec2.Scheduler
+	}
+	if spec2.Compiler != "" {
+		spec.Compiler = spec2.Compiler
+	}
+	if spec2.Linker != "" {
+		spec.Linker = spec2.Linker
+	}
+	if spec2.RTLib != "" {
+		spec.RTLib = spec2.RTLib
+	}
+	if spec2.Libc != "" {
+		spec.Libc = spec2.Libc
+	}
+	spec.CFlags = append(spec.CFlags, spec2.CFlags...)
+	spec.LDFlags = append(spec.LDFlags, spec2.LDFlags...)
+	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.FlashCommand != "" {
+		spec.FlashCommand = spec2.FlashCommand
+	}
+	if spec2.GDB != "" {
+		spec.GDB = spec2.GDB
+	}
+	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
 	}
 }

@@ -147,11 +177,11 @@ func (spec *TargetSpec) resolveInherits() error {
 		if err != nil {
 			return err
 		}
-		newSpec.overrideProperties(subtarget)
+		newSpec.copyProperties(subtarget)
 	}

 	// When all properties are loaded, make sure they are properly inherited.
-	newSpec.overrideProperties(spec)
+	newSpec.copyProperties(spec)
 	*spec = *newSpec

 	return nil
@@ -217,7 +247,6 @@ func LoadTarget(target string) (*TargetSpec, error) {
 		}
 		goarch := map[string]string{ // map from LLVM arch to Go arch
 			"i386":    "386",
-			"i686":    "386",
 			"x86_64":  "amd64",
 			"aarch64": "arm64",
 			"armv7":   "arm",
@@ -229,68 +258,44 @@ func LoadTarget(target string) (*TargetSpec, error) {
 	}
 }

-// WindowsBuildNotSupportedErr is being thrown, when goos is windows and no target has been specified.
-var WindowsBuildNotSupportedErr = errors.New("Building Windows binaries is currently not supported. Try specifying a different target")
-
 func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
-	if goos == "windows" {
-		return nil, WindowsBuildNotSupportedErr
-	}
 	// 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},
-		Scheduler:        "tasks",
-		Linker:           "cc",
-		DefaultStackSize: 1024 * 64, // 64kB
-		CFlags:           []string{"--target=" + triple},
-		GDB:              []string{"gdb"},
-		PortReset:        "false",
+		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.CFlags = append(spec.CFlags, "-isysroot", "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk")
 		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 != "wasm" {
-		spec.ExtraFiles = append(spec.ExtraFiles, "src/runtime/gc_"+goarch+".S")
-		spec.ExtraFiles = append(spec.ExtraFiles, "src/internal/task/task_stack_"+goarch+".S")
-	}
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
-		spec.GDB = []string{"gdb-multiarch"}
 		if goarch == "arm" && goos == "linux" {
 			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.GDB = "aarch64-linux-gnu-gdb"
 			spec.Emulator = []string{"qemu-aarch64", "-L", "/usr/aarch64-linux-gnu"}
 		}
-		if goarch == "386" && runtime.GOARCH == "amd64" {
-			spec.CFlags = append(spec.CFlags, "-m32")
-			spec.LDFlags = append(spec.LDFlags, "-m32")
+		if goarch == "386" {
+			spec.CFlags = []string{"-m32"}
+			spec.LDFlags = []string{"-m32"}
 		}
 	}
 	return &spec, nil
 }
-
-// LookupGDB looks up a gdb executable.
-func (spec *TargetSpec) LookupGDB() (string, error) {
-	if len(spec.GDB) == 0 {
-		return "", errors.New("gdb not configured in the target specification")
-	}
-	for _, d := range spec.GDB {
-		_, err := exec.LookPath(d)
-		if err == nil {
-			return d, nil
-		}
-	}
-	return "", errors.New("no gdb found configured in the target specification (" + strings.Join(spec.GDB, ", ") + ")")
-}
@@ -1,9 +1,6 @@
 package compileopts

-import (
-	"reflect"
-	"testing"
-)
+import "testing"

 func TestLoadTarget(t *testing.T) {
 	_, err := LoadTarget("arduino")
@@ -20,67 +17,3 @@ func TestLoadTarget(t *testing.T) {
 		t.Error("LoadTarget failed for wrong reason:", err)
 	}
 }
-
-func TestOverrideProperties(t *testing.T) {
-	baseAutoStackSize := true
-	base := &TargetSpec{
-		GOOS:             "baseGoos",
-		CPU:              "baseCpu",
-		Features:         []string{"bf1", "bf2"},
-		BuildTags:        []string{"bt1", "bt2"},
-		Emulator:         []string{"be1", "be2"},
-		DefaultStackSize: 42,
-		AutoStackSize:    &baseAutoStackSize,
-	}
-	childAutoStackSize := false
-	child := &TargetSpec{
-		GOOS:             "",
-		CPU:              "chlidCpu",
-		Features:         []string{"cf1", "cf2"},
-		Emulator:         []string{"ce1", "ce2"},
-		AutoStackSize:    &childAutoStackSize,
-		DefaultStackSize: 64,
-	}
-
-	base.overrideProperties(child)
-
-	if base.GOOS != "baseGoos" {
-		t.Errorf("Overriding failed : got %v", base.GOOS)
-	}
-	if base.CPU != "chlidCpu" {
-		t.Errorf("Overriding failed : got %v", base.CPU)
-	}
-	if !reflect.DeepEqual(base.Features, []string{"cf1", "cf2", "bf1", "bf2"}) {
-		t.Errorf("Overriding failed : got %v", base.Features)
-	}
-	if !reflect.DeepEqual(base.BuildTags, []string{"bt1", "bt2"}) {
-		t.Errorf("Overriding failed : got %v", base.BuildTags)
-	}
-	if !reflect.DeepEqual(base.Emulator, []string{"ce1", "ce2"}) {
-		t.Errorf("Overriding failed : got %v", base.Emulator)
-	}
-	if *base.AutoStackSize != false {
-		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
-	}
-	if base.DefaultStackSize != 64 {
-		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
-	}
-
-	baseAutoStackSize = true
-	base = &TargetSpec{
-		AutoStackSize:    &baseAutoStackSize,
-		DefaultStackSize: 42,
-	}
-	child = &TargetSpec{
-		AutoStackSize:    nil,
-		DefaultStackSize: 0,
-	}
-	base.overrideProperties(child)
-	if *base.AutoStackSize != true {
-		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
-	}
-	if base.DefaultStackSize != 42 {
-		t.Errorf("Overriding failed : got %v", base.DefaultStackSize)
-	}
-
-}
@@ -16,7 +16,7 @@ import (
 // slice. This is required by the Go language spec: an index out of bounds must
 // cause a panic.
 func (b *builder) createLookupBoundsCheck(arrayLen, index llvm.Value, indexType types.Type) {
-	if b.info.nobounds {
+	if b.fn.IsNoBounds() {
 		// The //go:nobounds pragma was added to the function to avoid bounds
 		// checking.
 		return
@@ -48,7 +48,7 @@ func (b *builder) createLookupBoundsCheck(arrayLen, index llvm.Value, indexType
 // biggest possible slice capacity, 'low' means len and 'high' means cap. The
 // logic is the same in both cases.
 func (b *builder) createSliceBoundsCheck(capacity, low, high, max llvm.Value, lowType, highType, maxType *types.Basic) {
-	if b.info.nobounds {
+	if b.fn.IsNoBounds() {
 		// The //go:nobounds pragma was added to the function to avoid bounds
 		// checking.
 		return
@@ -104,7 +104,7 @@ func (b *builder) createSliceBoundsCheck(capacity, low, high, max llvm.Value, lo
 // createChanBoundsCheck creates a bounds check before creating a new channel to
 // check that the value is not too big for runtime.chanMake.
 func (b *builder) createChanBoundsCheck(elementSize uint64, bufSize llvm.Value, bufSizeType *types.Basic, pos token.Pos) {
-	if b.info.nobounds {
+	if b.fn.IsNoBounds() {
 		// The //go:nobounds pragma was added to the function to avoid bounds
 		// checking.
 		return
@@ -159,9 +159,6 @@ func (b *builder) createNilCheck(inst ssa.Value, ptr llvm.Value, blockPrefix str
 	}

 	switch inst := inst.(type) {
-	case *ssa.Alloc:
-		// An alloc is never nil.
-		return
 	case *ssa.IndexAddr:
 		// This pointer is the result of an index operation into a slice or
 		// array. Such slices/arrays are already bounds checked so the pointer
@@ -192,7 +189,7 @@ func (b *builder) createNilCheck(inst ssa.Value, ptr llvm.Value, blockPrefix str
 // createNegativeShiftCheck creates an assertion that panics if the given shift value is negative.
 // This function assumes that the shift value is signed.
 func (b *builder) createNegativeShiftCheck(shift llvm.Value) {
-	if b.info.nobounds {
+	if b.fn.IsNoBounds() {
 		// Function disabled bounds checking - skip shift check.
 		return
 	}
@@ -215,8 +212,8 @@ func (b *builder) createRuntimeAssert(assert llvm.Value, blockPrefix, assertFunc
 		}
 	}

-	faultBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".throw")
-	nextBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".next")
+	faultBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, blockPrefix+".throw")
+	nextBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, blockPrefix+".next")
 	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes

 	// Now branch to the out-of-bounds or the regular block.
@@ -1,84 +0,0 @@
-package compiler
-
-import (
-	"strings"
-
-	"golang.org/x/tools/go/ssa"
-	"tinygo.org/x/go-llvm"
-)
-
-// createAtomicOp lowers an atomic library call by lowering it as an LLVM atomic
-// operation. It returns the result of the operation and true if the call could
-// be lowered inline, and false otherwise.
-func (b *builder) createAtomicOp(call *ssa.CallCommon) (llvm.Value, bool) {
-	name := call.Value.(*ssa.Function).Name()
-	switch name {
-	case "AddInt32", "AddInt64", "AddUint32", "AddUint64", "AddUintptr":
-		ptr := b.getValue(call.Args[0])
-		val := b.getValue(call.Args[1])
-		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpAdd, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
-		// Return the new value, not the original value returned by atomicrmw.
-		return b.CreateAdd(oldVal, val, ""), true
-	case "SwapInt32", "SwapInt64", "SwapUint32", "SwapUint64", "SwapUintptr", "SwapPointer":
-		ptr := b.getValue(call.Args[0])
-		val := b.getValue(call.Args[1])
-		isPointer := val.Type().TypeKind() == llvm.PointerTypeKind
-		if isPointer {
-			// atomicrmw only supports integers, so cast to an integer.
-			val = b.CreatePtrToInt(val, b.uintptrType, "")
-			ptr = b.CreateBitCast(ptr, llvm.PointerType(val.Type(), 0), "")
-		}
-		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpXchg, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
-		if isPointer {
-			oldVal = b.CreateIntToPtr(oldVal, b.i8ptrType, "")
-		}
-		return oldVal, true
-	case "CompareAndSwapInt32", "CompareAndSwapInt64", "CompareAndSwapUint32", "CompareAndSwapUint64", "CompareAndSwapUintptr", "CompareAndSwapPointer":
-		ptr := b.getValue(call.Args[0])
-		old := b.getValue(call.Args[1])
-		newVal := b.getValue(call.Args[2])
-		if strings.HasSuffix(name, "64") {
-			arch := strings.Split(b.Triple, "-")[0]
-			if strings.HasPrefix(arch, "arm") && strings.HasSuffix(arch, "m") {
-				// Work around a bug in LLVM, at least LLVM 11:
-				// https://reviews.llvm.org/D95891
-				// Check for armv6m, armv7, armv7em, and perhaps others.
-				// See also: https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html
-				compareAndSwap := b.mod.NamedFunction("__sync_val_compare_and_swap_8")
-				if compareAndSwap.IsNil() {
-					// Declare the function if it isn't already declared.
-					i64Type := b.ctx.Int64Type()
-					fnType := llvm.FunctionType(i64Type, []llvm.Type{llvm.PointerType(i64Type, 0), i64Type, i64Type}, false)
-					compareAndSwap = llvm.AddFunction(b.mod, "__sync_val_compare_and_swap_8", fnType)
-				}
-				actualOldValue := b.CreateCall(compareAndSwap, []llvm.Value{ptr, old, newVal}, "")
-				// The __sync_val_compare_and_swap_8 function returns the old
-				// value. However, we shouldn't return the old value, we should
-				// return whether the compare/exchange was successful. This is
-				// easily done by comparing the returned (actual) old value with
-				// the expected old value passed to
-				// __sync_val_compare_and_swap_8.
-				swapped := b.CreateICmp(llvm.IntEQ, old, actualOldValue, "")
-				return swapped, true
-			}
-		}
-		tuple := b.CreateAtomicCmpXchg(ptr, old, newVal, llvm.AtomicOrderingSequentiallyConsistent, llvm.AtomicOrderingSequentiallyConsistent, true)
-		swapped := b.CreateExtractValue(tuple, 1, "")
-		return swapped, true
-	case "LoadInt32", "LoadInt64", "LoadUint32", "LoadUint64", "LoadUintptr", "LoadPointer":
-		ptr := b.getValue(call.Args[0])
-		val := b.CreateLoad(ptr, "")
-		val.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
-		val.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
-		return val, true
-	case "StoreInt32", "StoreInt64", "StoreUint32", "StoreUint64", "StoreUintptr", "StorePointer":
-		ptr := b.getValue(call.Args[0])
-		val := b.getValue(call.Args[1])
-		store := b.CreateStore(val, ptr)
-		store.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
-		store.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
-		return store, true
-	default:
-		return llvm.Value{}, false
-	}
-}
@@ -4,7 +4,6 @@ import (
 	"go/types"
 	"strconv"

-	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )

@@ -35,14 +34,14 @@ const (

 // createCall creates a new call to runtime.<fnName> with the given arguments.
 func (b *builder) createRuntimeCall(fnName string, args []llvm.Value, name string) llvm.Value {
-	fn := b.program.ImportedPackage("runtime").Members[fnName].(*ssa.Function)
-	llvmFn := b.getFunction(fn)
-	if llvmFn.IsNil() {
-		panic("trying to call non-existent function: " + fn.RelString(nil))
+	fullName := "runtime." + fnName
+	fn := b.mod.NamedFunction(fullName)
+	if fn.IsNil() {
+		panic("trying to call non-existent function: " + fullName)
 	}
 	args = append(args, llvm.Undef(b.i8ptrType))            // unused context parameter
 	args = append(args, llvm.ConstPointerNull(b.i8ptrType)) // coroutine handle
-	return b.createCall(llvmFn, args, name)
+	return b.createCall(fn, args, name)
 }

 // createCall creates a call to the given function with the arguments possibly
@@ -58,10 +57,10 @@ func (b *builder) createCall(fn llvm.Value, args []llvm.Value, name string) llvm

 // Expand an argument type to a list that can be used in a function call
 // parameter list.
-func (c *compilerContext) expandFormalParamType(t llvm.Type, name string, goType types.Type) []paramInfo {
+func expandFormalParamType(t llvm.Type, name string, goType types.Type) []paramInfo {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		fieldInfos := c.flattenAggregateType(t, name, goType)
+		fieldInfos := flattenAggregateType(t, name, goType)
 		if len(fieldInfos) <= maxFieldsPerParam {
 			return fieldInfos
 		} else {
@@ -105,7 +104,7 @@ func (b *builder) expandFormalParamOffsets(t llvm.Type) []uint64 {
 func (b *builder) expandFormalParam(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
 	case llvm.StructTypeKind:
-		fieldInfos := b.flattenAggregateType(v.Type(), "", nil)
+		fieldInfos := flattenAggregateType(v.Type(), "", nil)
 		if len(fieldInfos) <= maxFieldsPerParam {
 			fields := b.flattenAggregate(v)
 			if len(fields) != len(fieldInfos) {
@@ -124,15 +123,12 @@ func (b *builder) expandFormalParam(v llvm.Value) []llvm.Value {

 // Try to flatten a struct type to a list of types. Returns a 1-element slice
 // with the passed in type if this is not possible.
-func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramInfo {
+func flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramInfo {
 	typeFlags := getTypeFlags(goType)
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		var paramInfos []paramInfo
+		paramInfos := make([]paramInfo, 0, t.StructElementTypesCount())
 		for i, subfield := range t.StructElementTypes() {
-			if c.targetData.TypeAllocSize(subfield) == 0 {
-				continue
-			}
 			suffix := strconv.Itoa(i)
 			if goType != nil {
 				// Try to come up with a good suffix for this struct field,
@@ -155,7 +151,7 @@ func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType
 					suffix = []string{"context", "funcptr"}[i]
 				}
 			}
-			subInfos := c.flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
+			subInfos := flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
 			for i := range subInfos {
 				subInfos[i].flags |= typeFlags
 			}
@@ -221,11 +217,8 @@ func extractSubfield(t types.Type, field int) types.Type {
 func (c *compilerContext) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		var fields []uint64
+		fields := make([]uint64, 0, t.StructElementTypesCount())
 		for fieldIndex, field := range t.StructElementTypes() {
-			if c.targetData.TypeAllocSize(field) == 0 {
-				continue
-			}
 			suboffsets := c.flattenAggregateTypeOffsets(field)
 			offset := c.targetData.ElementOffset(t, fieldIndex)
 			for i := range suboffsets {
@@ -244,11 +237,8 @@ func (c *compilerContext) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
 func (b *builder) flattenAggregate(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
 	case llvm.StructTypeKind:
-		var fields []llvm.Value
-		for i, field := range v.Type().StructElementTypes() {
-			if b.targetData.TypeAllocSize(field) == 0 {
-				continue
-			}
+		fields := make([]llvm.Value, 0, v.Type().StructElementTypesCount())
+		for i := range v.Type().StructElementTypes() {
 			subfield := b.CreateExtractValue(v, i, "")
 			subfields := b.flattenAggregate(subfield)
 			fields = append(fields, subfields...)
@@ -275,13 +265,10 @@ func (b *builder) collapseFormalParam(t llvm.Type, fields []llvm.Value) llvm.Val
 func (b *builder) collapseFormalParamInternal(t llvm.Type, fields []llvm.Value) (llvm.Value, []llvm.Value) {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		flattened := b.flattenAggregateType(t, "", nil)
+		flattened := flattenAggregateType(t, "", nil)
 		if len(flattened) <= maxFieldsPerParam {
 			value := llvm.ConstNull(t)
 			for i, subtyp := range t.StructElementTypes() {
-				if b.targetData.TypeAllocSize(subtyp) == 0 {
-					continue
-				}
 				structField, remaining := b.collapseFormalParamInternal(subtyp, fields)
 				fields = remaining
 				value = b.CreateInsertValue(value, structField, i, "")
@@ -12,7 +12,7 @@ import (
 )

 func (b *builder) createMakeChan(expr *ssa.MakeChan) llvm.Value {
-	elementSize := b.targetData.TypeAllocSize(b.getLLVMType(expr.Type().Underlying().(*types.Chan).Elem()))
+	elementSize := b.targetData.TypeAllocSize(b.getLLVMType(expr.Type().(*types.Chan).Elem()))
 	elementSizeValue := llvm.ConstInt(b.uintptrType, elementSize, false)
 	bufSize := b.getValue(expr.Size)
 	b.createChanBoundsCheck(elementSize, bufSize, expr.Size.Type().Underlying().(*types.Basic), expr.Pos())
@@ -35,37 +35,27 @@ func (b *builder) createChanSend(instr *ssa.Send) {
 	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")
 	b.CreateStore(chanValue, valueAlloca)

-	// Allocate blockedlist buffer.
-	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
-	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
-
 	// Do the send.
-	b.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
+	b.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast}, "")

-	// End the lifetime of the allocas.
+	// 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
-	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
 	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
 }

 // createChanRecv emits a pseudo chan receive operation. It is lowered to the
 // actual channel receive operation during goroutine lowering.
 func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
-	valueType := b.getLLVMType(unop.X.Type().Underlying().(*types.Chan).Elem())
+	valueType := b.getLLVMType(unop.X.Type().(*types.Chan).Elem())
 	ch := b.getValue(unop.X)

 	// Allocate memory to receive into.
 	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")

-	// Allocate blockedlist buffer.
-	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
-	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
-
 	// Do the receive.
-	commaOk := b.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
+	commaOk := b.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast}, "")
 	received := b.CreateLoad(valueAlloca, "chan.received")
-	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
 	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)

 	if unop.CommaOk {
@@ -79,7 +69,8 @@ func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
 }

 // createChanClose closes the given channel.
-func (b *builder) createChanClose(ch llvm.Value) {
+func (b *builder) createChanClose(param ssa.Value) {
+	ch := b.getValue(param)
 	b.createRuntimeCall("chanClose", []llvm.Value{ch}, "")
 }

@@ -126,7 +117,7 @@ func (b *builder) createSelect(expr *ssa.Select) llvm.Value {
 		switch state.Dir {
 		case types.RecvOnly:
 			// Make sure the receive buffer is big enough and has the correct alignment.
-			llvmType := b.getLLVMType(state.Chan.Type().Underlying().(*types.Chan).Elem())
+			llvmType := b.getLLVMType(state.Chan.Type().(*types.Chan).Elem())
 			if size := b.targetData.TypeAllocSize(llvmType); size > recvbufSize {
 				recvbufSize = size
 			}
@@ -1,167 +0,0 @@
-package compiler
-
-import (
-	"flag"
-	"go/types"
-	"io/ioutil"
-	"strconv"
-	"strings"
-	"testing"
-
-	"github.com/tinygo-org/tinygo/compileopts"
-	"github.com/tinygo-org/tinygo/loader"
-	"tinygo.org/x/go-llvm"
-)
-
-// Pass -update to go test to update the output of the test files.
-var flagUpdate = flag.Bool("update", false, "update tests based on test output")
-
-// Basic tests for the compiler. Build some Go files and compare the output with
-// the expected LLVM IR for regression testing.
-func TestCompiler(t *testing.T) {
-	// Check LLVM version.
-	llvmMajor, err := strconv.Atoi(strings.SplitN(llvm.Version, ".", 2)[0])
-	if err != nil {
-		t.Fatal("could not parse LLVM version:", llvm.Version)
-	}
-	if llvmMajor < 11 {
-		// It is likely this version needs to be bumped in the future.
-		// The goal is to at least test the LLVM version that's used by default
-		// in TinyGo and (if possible without too many workarounds) also some
-		// previous versions.
-		t.Skip("compiler tests require LLVM 11 or above, got LLVM ", llvm.Version)
-	}
-
-	target, err := compileopts.LoadTarget("wasm")
-	if err != nil {
-		t.Fatal("failed to load target:", err)
-	}
-	config := &compileopts.Config{
-		Options: &compileopts.Options{},
-		Target:  target,
-	}
-	compilerConfig := &Config{
-		Triple:             config.Triple(),
-		GOOS:               config.GOOS(),
-		GOARCH:             config.GOARCH(),
-		CodeModel:          config.CodeModel(),
-		RelocationModel:    config.RelocationModel(),
-		Scheduler:          config.Scheduler(),
-		FuncImplementation: config.FuncImplementation(),
-		AutomaticStackSize: config.AutomaticStackSize(),
-	}
-	machine, err := NewTargetMachine(compilerConfig)
-	if err != nil {
-		t.Fatal("failed to create target machine:", err)
-	}
-
-	tests := []string{
-		"basic.go",
-		"pointer.go",
-		"slice.go",
-		"string.go",
-		"float.go",
-		"interface.go",
-		"func.go",
-	}
-
-	for _, testCase := range tests {
-		t.Run(testCase, func(t *testing.T) {
-			// Load entire program AST into memory.
-			lprogram, err := loader.Load(config, []string{"./testdata/" + testCase}, config.ClangHeaders, types.Config{
-				Sizes: Sizes(machine),
-			})
-			if err != nil {
-				t.Fatal("failed to create target machine:", err)
-			}
-			err = lprogram.Parse()
-			if err != nil {
-				t.Fatalf("could not parse test case %s: %s", testCase, err)
-			}
-
-			// Compile AST to IR.
-			program := lprogram.LoadSSA()
-			pkg := lprogram.MainPkg()
-			mod, errs := CompilePackage(testCase, pkg, program.Package(pkg.Pkg), machine, compilerConfig, false)
-			if errs != nil {
-				for _, err := range errs {
-					t.Error(err)
-				}
-				return
-			}
-
-			err = llvm.VerifyModule(mod, llvm.PrintMessageAction)
-			if err != nil {
-				t.Error(err)
-			}
-
-			// Optimize IR a little.
-			funcPasses := llvm.NewFunctionPassManagerForModule(mod)
-			defer funcPasses.Dispose()
-			funcPasses.AddInstructionCombiningPass()
-			funcPasses.InitializeFunc()
-			for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
-				funcPasses.RunFunc(fn)
-			}
-			funcPasses.FinalizeFunc()
-
-			outfile := "./testdata/" + testCase[:len(testCase)-3] + ".ll"
-
-			// Update test if needed. Do not check the result.
-			if *flagUpdate {
-				err := ioutil.WriteFile(outfile, []byte(mod.String()), 0666)
-				if err != nil {
-					t.Error("failed to write updated output file:", err)
-				}
-				return
-			}
-
-			expected, err := ioutil.ReadFile(outfile)
-			if err != nil {
-				t.Fatal("failed to read golden file:", err)
-			}
-
-			if !fuzzyEqualIR(mod.String(), string(expected)) {
-				t.Errorf("output does not match expected output:\n%s", mod.String())
-			}
-		})
-	}
-}
-
-// 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, line1 := range lines1 {
-		line2 := lines2[i]
-		if line1 != line2 {
-			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.Split(line, ";")[0]    // strip out comments/info
-		line = strings.TrimRight(line, "\r ") // drop '\r' on Windows and remove trailing spaces from comments
-		if line == "" {
-			continue
-		}
-		if strings.HasPrefix(line, "source_filename = ") {
-			continue
-		}
-		out = append(out, line)
-	}
-	return out
-}
@@ -14,9 +14,8 @@ package compiler
 //     frames.

 import (
-	"go/types"
-
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"github.com/tinygo-org/tinygo/ir"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -26,11 +25,9 @@ import (
 // calls.
 func (b *builder) deferInitFunc() {
 	// Some setup.
-	b.deferFuncs = make(map[*ssa.Function]int)
+	b.deferFuncs = make(map[*ir.Function]int)
 	b.deferInvokeFuncs = make(map[string]int)
-	b.deferClosureFuncs = make(map[*ssa.Function]int)
-	b.deferExprFuncs = make(map[ssa.Value]int)
-	b.deferBuiltinFuncs = make(map[ssa.Value]deferBuiltin)
+	b.deferClosureFuncs = make(map[*ir.Function]int)

 	// Create defer list pointer.
 	deferType := llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)
@@ -107,11 +104,13 @@ func (b *builder) createDefer(instr *ssa.Defer) {

 	} else if callee, ok := instr.Call.Value.(*ssa.Function); ok {
 		// Regular function call.
-		if _, ok := b.deferFuncs[callee]; !ok {
-			b.deferFuncs[callee] = len(b.allDeferFuncs)
-			b.allDeferFuncs = append(b.allDeferFuncs, callee)
+		fn := b.ir.GetFunction(callee)
+
+		if _, ok := b.deferFuncs[fn]; !ok {
+			b.deferFuncs[fn] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, fn)
 		}
-		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferFuncs[callee]), false)
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferFuncs[fn]), false)

 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields).
@@ -133,7 +132,7 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		context := b.CreateExtractValue(closure, 0, "")

 		// Get the callback number.
-		fn := makeClosure.Fn.(*ssa.Function)
+		fn := b.ir.GetFunction(makeClosure.Fn.(*ssa.Function))
 		if _, ok := b.deferClosureFuncs[fn]; !ok {
 			b.deferClosureFuncs[fn] = len(b.allDeferFuncs)
 			b.allDeferFuncs = append(b.allDeferFuncs, makeClosure)
@@ -152,53 +151,9 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		values = append(values, context)
 		valueTypes = append(valueTypes, context.Type())

-	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
-		var argTypes []types.Type
-		var argValues []llvm.Value
-		for _, arg := range instr.Call.Args {
-			argTypes = append(argTypes, arg.Type())
-			argValues = append(argValues, b.getValue(arg))
-		}
-
-		if _, ok := b.deferBuiltinFuncs[instr.Call.Value]; !ok {
-			b.deferBuiltinFuncs[instr.Call.Value] = deferBuiltin{
-				callName: builtin.Name(),
-				pos:      builtin.Pos(),
-				argTypes: argTypes,
-				callback: len(b.allDeferFuncs),
-			}
-			b.allDeferFuncs = append(b.allDeferFuncs, instr.Call.Value)
-		}
-		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferBuiltinFuncs[instr.Call.Value].callback), false)
-
-		// Collect all values to be put in the struct (starting with
-		// runtime._defer fields).
-		values = []llvm.Value{callback, next}
-		for _, param := range argValues {
-			values = append(values, param)
-			valueTypes = append(valueTypes, param.Type())
-		}
-
 	} else {
-		funcValue := b.getValue(instr.Call.Value)
-
-		if _, ok := b.deferExprFuncs[instr.Call.Value]; !ok {
-			b.deferExprFuncs[instr.Call.Value] = len(b.allDeferFuncs)
-			b.allDeferFuncs = append(b.allDeferFuncs, &instr.Call)
-		}
-
-		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferExprFuncs[instr.Call.Value]), false)
-
-		// Collect all values to be put in the struct (starting with
-		// runtime._defer fields, followed by all parameters including the
-		// context pointer).
-		values = []llvm.Value{callback, next, funcValue}
-		valueTypes = append(valueTypes, funcValue.Type())
-		for _, param := range instr.Call.Args {
-			llvmParam := b.getValue(param)
-			values = append(values, llvmParam)
-			valueTypes = append(valueTypes, llvmParam.Type())
-		}
+		b.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.
@@ -220,7 +175,7 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		allocCall := b.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "defer.alloc.call")
 		alloca = b.CreateBitCast(allocCall, llvm.PointerType(deferFrameType, 0), "defer.alloc")
 	}
-	if b.NeedsStackObjects {
+	if b.NeedsStackObjects() {
 		b.trackPointer(alloca)
 	}
 	b.CreateStore(deferFrame, alloca)
@@ -248,10 +203,10 @@ func (b *builder) createRunDefers() {
 	//     }

 	// Create loop.
-	loophead := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.loophead")
-	loop := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.loop")
-	unreachable := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.default")
-	end := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.end")
+	loophead := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.loophead")
+	loop := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.loop")
+	unreachable := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.default")
+	end := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.end")
 	b.CreateBr(loophead)

 	// Create loop head:
@@ -283,28 +238,21 @@ func (b *builder) createRunDefers() {
 		// Create switch case, for example:
 		//     case 0:
 		//         // run first deferred call
-		block := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.callback")
+		block := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.callback")
 		sw.AddCase(llvm.ConstInt(b.uintptrType, uint64(i), false), block)
 		b.SetInsertPointAtEnd(block)
 		switch callback := callback.(type) {
 		case *ssa.CallCommon:
-			// Call on an value or interface value.
-
-			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
-
+			// Call on an interface value.
 			if !callback.IsInvoke() {
-				//Expect funcValue to be passed through the defer frame.
-				valueTypes = append(valueTypes, b.getFuncType(callback.Signature()))
-			} else {
-				//Expect typecode
-				valueTypes = append(valueTypes, b.uintptrType, b.i8ptrType)
+				panic("expected an invoke call, not a direct call")
 			}

+			// Get the real defer struct type and cast to it.
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0), b.uintptrType, b.i8ptrType}
 			for _, arg := range callback.Args {
 				valueTypes = append(valueTypes, b.getLLVMType(arg.Type()))
 			}
-
 			deferFrameType := b.ctx.StructType(valueTypes, false)
 			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")

@@ -317,42 +265,26 @@ func (b *builder) createRunDefers() {
 				forwardParams = append(forwardParams, forwardParam)
 			}

-			var fnPtr llvm.Value
+			// Isolate the typecode.
+			typecode, forwardParams := forwardParams[0], forwardParams[1:]

-			if !callback.IsInvoke() {
-				// Isolate the func value.
-				funcValue := forwardParams[0]
-				forwardParams = forwardParams[1:]
-
-				//Get function pointer and context
-				fp, context := b.decodeFuncValue(funcValue, callback.Signature())
-				fnPtr = fp
-
-				//Pass context
-				forwardParams = append(forwardParams, context)
-			} else {
-				// Isolate the typecode.
-				typecode := forwardParams[0]
-				forwardParams = forwardParams[1:]
-				fnPtr = b.getInvokePtr(callback, typecode)
-
-				// Add the context parameter. An interface call cannot also be a
-				// closure but we have to supply the parameter anyway for platforms
-				// with a strict calling convention.
-				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
-			}
+			// Add the context parameter. An interface call cannot also be a
+			// closure but we have to supply the parameter anyway for platforms
+			// with a strict calling convention.
+			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))

 			// Parent coroutine handle.
 			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))

+			fnPtr := b.getInvokePtr(callback, typecode)
 			b.createCall(fnPtr, forwardParams, "")

-		case *ssa.Function:
+		case *ir.Function:
 			// Direct call.

 			// Get the real defer struct type and cast to it.
 			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
-			for _, param := range getParams(callback.Signature) {
+			for _, param := range callback.Params {
 				valueTypes = append(valueTypes, b.getLLVMType(param.Type()))
 			}
 			deferFrameType := b.ctx.StructType(valueTypes, false)
@@ -361,7 +293,7 @@ func (b *builder) createRunDefers() {
 			// Extract the params from the struct.
 			forwardParams := []llvm.Value{}
 			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
-			for i := range getParams(callback.Signature) {
+			for i := range callback.Params {
 				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
 				forwardParam := b.CreateLoad(gep, "param")
 				forwardParams = append(forwardParams, forwardParam)
@@ -369,7 +301,7 @@ func (b *builder) createRunDefers() {

 			// Plain TinyGo functions add some extra parameters to implement async functionality and function recievers.
 			// These parameters should not be supplied when calling into an external C/ASM function.
-			if !b.getFunctionInfo(callback).exported {
+			if !callback.IsExported() {
 				// Add the context parameter. We know it is ignored by the receiving
 				// function, but we have to pass one anyway.
 				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
@@ -379,11 +311,11 @@ func (b *builder) createRunDefers() {
 			}

 			// Call real function.
-			b.createCall(b.getFunction(callback), forwardParams, "")
+			b.createCall(callback.LLVMFn, forwardParams, "")

 		case *ssa.MakeClosure:
 			// Get the real defer struct type and cast to it.
-			fn := callback.Fn.(*ssa.Function)
+			fn := b.ir.GetFunction(callback.Fn.(*ssa.Function))
 			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
 			params := fn.Signature.Params()
 			for i := 0; i < params.Len(); i++ {
@@ -406,35 +338,8 @@ func (b *builder) createRunDefers() {
 			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))

 			// Call deferred function.
-			b.createCall(b.getFunction(fn), forwardParams, "")
-		case *ssa.Builtin:
-			db := b.deferBuiltinFuncs[callback]
+			b.createCall(fn.LLVMFn, forwardParams, "")

-			//Get parameter types
-			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
-
-			//Get signature from call results
-			params := callback.Type().Underlying().(*types.Signature).Params()
-			for i := 0; i < params.Len(); i++ {
-				valueTypes = append(valueTypes, b.getLLVMType(params.At(i).Type()))
-			}
-
-			deferFrameType := b.ctx.StructType(valueTypes, false)
-			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
-
-			// Extract the params from the struct.
-			var argValues []llvm.Value
-			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
-			for i := 0; i < params.Len(); i++ {
-				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
-				forwardParam := b.CreateLoad(gep, "param")
-				argValues = append(argValues, forwardParam)
-			}
-
-			_, err := b.createBuiltin(db.argTypes, argValues, db.callName, db.pos)
-			if err != nil {
-				b.diagnostics = append(b.diagnostics, err)
-			}
 		default:
 			panic("unknown deferred function type")
 		}
@@ -14,7 +14,7 @@ import (
 // makeError makes it easy to create an error from a token.Pos with a message.
 func (c *compilerContext) makeError(pos token.Pos, msg string) types.Error {
 	return types.Error{
-		Fset: c.program.Fset,
+		Fset: c.ir.Program.Fset,
 		Pos:  pos,
 		Msg:  msg,
 	}
@@ -6,6 +6,7 @@ package compiler
 import (
 	"go/types"

+	"github.com/tinygo-org/tinygo/compileopts"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -20,23 +21,24 @@ func (b *builder) createFuncValue(funcPtr, context llvm.Value, sig *types.Signat
 // context.
 func (c *compilerContext) createFuncValue(builder llvm.Builder, funcPtr, context llvm.Value, sig *types.Signature) llvm.Value {
 	var funcValueScalar llvm.Value
-	switch c.FuncImplementation {
-	case "doubleword":
+	switch c.FuncImplementation() {
+	case compileopts.FuncValueDoubleword:
 		// Closure is: {context, function pointer}
 		funcValueScalar = funcPtr
-	case "switch":
+	case compileopts.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),
-				c.getFuncSignatureID(sig),
+				sigGlobal,
 			})
 			funcValueWithSignatureGlobal = llvm.AddGlobal(c.mod, funcValueWithSignatureType, funcValueWithSignatureGlobalName)
 			funcValueWithSignatureGlobal.SetInitializer(funcValueWithSignature)
 			funcValueWithSignatureGlobal.SetGlobalConstant(true)
-			funcValueWithSignatureGlobal.SetLinkage(llvm.LinkOnceODRLinkage)
+			funcValueWithSignatureGlobal.SetLinkage(llvm.InternalLinkage)
 		}
 		funcValueScalar = llvm.ConstPtrToInt(funcValueWithSignatureGlobal, c.uintptrType)
 	default:
@@ -49,19 +51,6 @@ func (c *compilerContext) createFuncValue(builder llvm.Builder, funcPtr, context
 	return funcValue
 }

-// getFuncSignatureID returns a new external global for a given signature. This
-// global reference is not real, it is only used during func lowering to assign
-// signature types to functions and will then be removed.
-func (c *compilerContext) getFuncSignatureID(sig *types.Signature) llvm.Value {
-	sigGlobalName := "reflect/types.funcid:" + getTypeCodeName(sig)
-	sigGlobal := c.mod.NamedGlobal(sigGlobalName)
-	if sigGlobal.IsNil() {
-		sigGlobal = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), sigGlobalName)
-		sigGlobal.SetGlobalConstant(true)
-	}
-	return sigGlobal
-}
-
 // extractFuncScalar returns some scalar that can be used in comparisons. It is
 // a cheap operation.
 func (b *builder) extractFuncScalar(funcValue llvm.Value) llvm.Value {
@@ -78,12 +67,12 @@ func (b *builder) extractFuncContext(funcValue llvm.Value) llvm.Value {
 // value. This may be an expensive operation.
 func (b *builder) decodeFuncValue(funcValue llvm.Value, sig *types.Signature) (funcPtr, context llvm.Value) {
 	context = b.CreateExtractValue(funcValue, 0, "")
-	switch b.FuncImplementation {
-	case "doubleword":
+	switch b.FuncImplementation() {
+	case compileopts.FuncValueDoubleword:
 		funcPtr = b.CreateExtractValue(funcValue, 1, "")
-	case "switch":
+	case compileopts.FuncValueSwitch:
 		llvmSig := b.getRawFuncType(sig)
-		sigGlobal := b.getFuncSignatureID(sig)
+		sigGlobal := b.getTypeCode(sig)
 		funcPtr = b.createRuntimeCall("getFuncPtr", []llvm.Value{funcValue, sigGlobal}, "")
 		funcPtr = b.CreateIntToPtr(funcPtr, llvmSig, "")
 	default:
@@ -94,11 +83,11 @@ func (b *builder) decodeFuncValue(funcValue llvm.Value, sig *types.Signature) (f

 // getFuncType returns the type of a func value given a signature.
 func (c *compilerContext) getFuncType(typ *types.Signature) llvm.Type {
-	switch c.FuncImplementation {
-	case "doubleword":
+	switch c.FuncImplementation() {
+	case compileopts.FuncValueDoubleword:
 		rawPtr := c.getRawFuncType(typ)
 		return c.ctx.StructType([]llvm.Type{c.i8ptrType, rawPtr}, false)
-	case "switch":
+	case compileopts.FuncValueSwitch:
 		return c.getLLVMRuntimeType("funcValue")
 	default:
 		panic("unimplemented func value variant")
@@ -136,13 +125,13 @@ func (c *compilerContext) getRawFuncType(typ *types.Signature) llvm.Type {
 			// The receiver is not an interface, but a i8* type.
 			recv = c.i8ptrType
 		}
-		for _, info := range c.expandFormalParamType(recv, "", nil) {
+		for _, info := range expandFormalParamType(recv, "", nil) {
 			paramTypes = append(paramTypes, info.llvmType)
 		}
 	}
 	for i := 0; i < typ.Params().Len(); i++ {
 		subType := c.getLLVMType(typ.Params().At(i).Type())
-		for _, info := range c.expandFormalParamType(subType, "", nil) {
+		for _, info := range expandFormalParamType(subType, "", nil) {
 			paramTypes = append(paramTypes, info.llvmType)
 		}
 	}
@@ -160,7 +149,7 @@ func (b *builder) parseMakeClosure(expr *ssa.MakeClosure) (llvm.Value, error) {
 	if len(expr.Bindings) == 0 {
 		panic("unexpected: MakeClosure without bound variables")
 	}
-	f := expr.Fn.(*ssa.Function)
+	f := b.ir.GetFunction(expr.Fn.(*ssa.Function))

 	// Collect all bound variables.
 	boundVars := make([]llvm.Value, len(expr.Bindings))
@@ -175,5 +164,5 @@ func (b *builder) parseMakeClosure(expr *ssa.MakeClosure) (llvm.Value, error) {
 	context := b.emitPointerPack(boundVars)

 	// Create the closure.
-	return b.createFuncValue(b.getFunction(f), context, f.Signature), nil
+	return b.createFuncValue(f.LLVMFn, context, f.Signature), nil
 }
@@ -7,7 +7,6 @@ import (
 	"go/token"

 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
-	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )

@@ -20,35 +19,16 @@ import (
 // Because a go statement doesn't return anything, return undef.
 func (b *builder) createGoInstruction(funcPtr llvm.Value, params []llvm.Value, prefix string, pos token.Pos) llvm.Value {
 	paramBundle := b.emitPointerPack(params)
-	var callee, stackSize llvm.Value
-	switch b.Scheduler {
+	var callee llvm.Value
+	switch b.Scheduler() {
 	case "none", "tasks":
 		callee = b.createGoroutineStartWrapper(funcPtr, prefix, pos)
-		if b.AutomaticStackSize {
-			// The stack size is not known until after linking. Call a dummy
-			// function that will be replaced with a load from a special ELF
-			// section that contains the stack size (and is modified after
-			// linking).
-			stackSizeFn := b.getFunction(b.program.ImportedPackage("internal/task").Members["getGoroutineStackSize"].(*ssa.Function))
-			stackSize = b.createCall(stackSizeFn, []llvm.Value{callee, llvm.Undef(b.i8ptrType), llvm.Undef(b.i8ptrType)}, "stacksize")
-		} else {
-			// The stack size is fixed at compile time. By emitting it here as a
-			// constant, it can be optimized.
-			if b.Scheduler == "tasks" && b.DefaultStackSize == 0 {
-				b.addError(pos, "default stack size for goroutines is not set")
-			}
-			stackSize = llvm.ConstInt(b.uintptrType, b.DefaultStackSize, false)
-		}
 	case "coroutines":
 		callee = b.CreatePtrToInt(funcPtr, b.uintptrType, "")
-		// There is no goroutine stack size: coroutines are used instead of
-		// stacks.
-		stackSize = llvm.Undef(b.uintptrType)
 	default:
 		panic("unreachable")
 	}
-	start := b.getFunction(b.program.ImportedPackage("internal/task").Members["start"].(*ssa.Function))
-	b.createCall(start, []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
+	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
 	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
 }

@@ -87,14 +67,13 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		// 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.LinkOnceODRLinkage)
+		wrapper.SetLinkage(llvm.PrivateLinkage)
 		wrapper.SetUnnamedAddr(true)
-		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", name))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)

-		if c.Debug {
-			pos := c.program.Fset.Position(pos)
+		if c.Debug() {
+			pos := c.ir.Program.Fset.Position(pos)
 			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
 				File:       c.getDIFile(pos.Filename),
 				Parameters: nil, // do not show parameters in debugger
@@ -144,14 +123,13 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		// Create the wrapper.
 		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
 		wrapper = llvm.AddFunction(c.mod, prefix+".gowrapper", wrapperType)
-		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
+		wrapper.SetLinkage(llvm.InternalLinkage)
 		wrapper.SetUnnamedAddr(true)
-		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", ""))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)

-		if c.Debug {
-			pos := c.program.Fset.Position(pos)
+		if c.Debug() {
+			pos := c.ir.Program.Fset.Position(pos)
 			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
 				File:       c.getDIFile(pos.Filename),
 				Parameters: nil, // do not show parameters in debugger
@@ -163,44 +163,6 @@ func (b *builder) emitSVCall(args []ssa.Value) (llvm.Value, error) {
 	return b.CreateCall(target, llvmArgs, ""), 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.
-// Same as emitSVCall but for AArch64
-func (b *builder) emitSV64Call(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 := "={x0}"
-	for i, arg := range args[1:] {
-		arg = arg.(*ssa.MakeInterface).X
-		if i == 0 {
-			constraints += ",0"
-		} else {
-			constraints += ",{x" + strconv.Itoa(i) + "}"
-		}
-		llvmValue := b.getValue(arg)
-		llvmArgs = append(llvmArgs, llvmValue)
-		argTypes = append(argTypes, llvmValue.Type())
-	}
-	// Implement the ARM64 calling convention by marking x1-x7 as
-	// clobbered. x0 is used as an output register so doesn't have to be
-	// marked as clobbered.
-	constraints += ",~{x1},~{x2},~{x3},~{x4},~{x5},~{x6},~{x7}"
-	fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
-	target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
-	return b.CreateCall(target, llvmArgs, ""), nil
-}
-
 // This is a compiler builtin which emits CSR instructions. It can be one of:
 //
 //     func (csr CSR) Get() uintptr
@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"

+	"github.com/tinygo-org/tinygo/ir"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -24,7 +25,16 @@ import (
 func (b *builder) createMakeInterface(val llvm.Value, typ types.Type, pos token.Pos) llvm.Value {
 	itfValue := b.emitPointerPack([]llvm.Value{val})
 	itfTypeCodeGlobal := b.getTypeCode(typ)
-	itfTypeCode := b.CreatePtrToInt(itfTypeCodeGlobal, b.uintptrType, "")
+	itfMethodSetGlobal := b.getTypeMethodSet(typ)
+	itfConcreteTypeGlobal := b.mod.NamedGlobal("typeInInterface:" + itfTypeCodeGlobal.Name())
+	if itfConcreteTypeGlobal.IsNil() {
+		typeInInterface := b.getLLVMRuntimeType("typeInInterface")
+		itfConcreteTypeGlobal = llvm.AddGlobal(b.mod, typeInInterface, "typeInInterface:"+itfTypeCodeGlobal.Name())
+		itfConcreteTypeGlobal.SetInitializer(llvm.ConstNamedStruct(typeInInterface, []llvm.Value{itfTypeCodeGlobal, itfMethodSetGlobal}))
+		itfConcreteTypeGlobal.SetGlobalConstant(true)
+		itfConcreteTypeGlobal.SetLinkage(llvm.PrivateLinkage)
+	}
+	itfTypeCode := b.CreatePtrToInt(itfConcreteTypeGlobal, b.uintptrType, "")
 	itf := llvm.Undef(b.getLLVMRuntimeType("_interface"))
 	itf = b.CreateInsertValue(itf, itfTypeCode, 0, "")
 	itf = b.CreateInsertValue(itf, itfValue, 1, "")
@@ -45,8 +55,6 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		// reflect lowering simpler.
 		var references llvm.Value
 		var length int64
-		var methodSet llvm.Value
-		var ptrTo llvm.Value
 		switch typ := typ.(type) {
 		case *types.Named:
 			references = c.getTypeCode(typ.Underlying())
@@ -63,32 +71,18 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 			// Take a pointer to the typecodeID of the first field (if it exists).
 			structGlobal := c.makeStructTypeFields(typ)
 			references = llvm.ConstBitCast(structGlobal, global.Type())
-		case *types.Interface:
-			methodSetGlobal := c.getInterfaceMethodSet(typ)
-			references = llvm.ConstBitCast(methodSetGlobal, global.Type())
 		}
-		if _, ok := typ.Underlying().(*types.Interface); !ok {
-			methodSet = c.getTypeMethodSet(typ)
-		}
-		if _, ok := typ.Underlying().(*types.Pointer); !ok {
-			ptrTo = c.getTypeCode(types.NewPointer(typ))
-		}
-		globalValue := llvm.ConstNull(global.Type().ElementType())
 		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)
 		}
-		if length != 0 {
-			lengthValue := llvm.ConstInt(c.uintptrType, uint64(length), false)
-			globalValue = llvm.ConstInsertValue(globalValue, lengthValue, []uint32{1})
-		}
-		if !methodSet.IsNil() {
-			globalValue = llvm.ConstInsertValue(globalValue, methodSet, []uint32{2})
-		}
-		if !ptrTo.IsNil() {
-			globalValue = llvm.ConstInsertValue(globalValue, ptrTo, []uint32{3})
-		}
-		global.SetInitializer(globalValue)
-		global.SetLinkage(llvm.LinkOnceODRLinkage)
 		global.SetGlobalConstant(true)
 	}
 	return global
@@ -110,8 +104,8 @@ func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
 		fieldName.SetLinkage(llvm.PrivateLinkage)
 		fieldName.SetUnnamedAddr(true)
 		fieldName = llvm.ConstGEP(fieldName, []llvm.Value{
-			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
-			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(llvm.Int32Type(), 0, false),
+			llvm.ConstInt(llvm.Int32Type(), 0, false),
 		})
 		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldName, []uint32{1})
 		if typ.Tag(i) != "" {
@@ -119,8 +113,8 @@ func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
 			fieldTag.SetLinkage(llvm.PrivateLinkage)
 			fieldTag.SetUnnamedAddr(true)
 			fieldTag = llvm.ConstGEP(fieldTag, []llvm.Value{
-				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
-				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(llvm.Int32Type(), 0, false),
+				llvm.ConstInt(llvm.Int32Type(), 0, false),
 			})
 			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldTag, []uint32{2})
 		}
@@ -193,7 +187,7 @@ func getTypeCodeName(t types.Type) string {
 	case *types.Interface:
 		methods := make([]string, t.NumMethods())
 		for i := 0; i < t.NumMethods(); i++ {
-			methods[i] = t.Method(i).Name() + ":" + getTypeCodeName(t.Method(i).Type())
+			methods[i] = getTypeCodeName(t.Method(i).Type())
 		}
 		return "interface:" + "{" + strings.Join(methods, ",") + "}"
 	case *types.Map:
@@ -242,7 +236,7 @@ func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}

-	ms := c.program.MethodSets.MethodSet(typ)
+	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.getLLVMRuntimeType("interfaceMethodInfo"), 0))
@@ -253,16 +247,15 @@ func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 	for i := 0; i < ms.Len(); i++ {
 		method := ms.At(i)
 		signatureGlobal := c.getMethodSignature(method.Obj().(*types.Func))
-		fn := c.program.MethodValue(method)
-		llvmFn := c.getFunction(fn)
-		if llvmFn.IsNil() {
+		f := c.ir.GetFunction(c.ir.Program.MethodValue(method))
+		if f.LLVMFn.IsNil() {
 			// compiler error, so panic
-			panic("cannot find function: " + c.getFunctionInfo(fn).linkName)
+			panic("cannot find function: " + f.LinkName())
 		}
-		wrapper := c.getInterfaceInvokeWrapper(fn, llvmFn)
+		fn := c.getInterfaceInvokeWrapper(f)
 		methodInfo := llvm.ConstNamedStruct(interfaceMethodInfoType, []llvm.Value{
 			signatureGlobal,
-			llvm.ConstPtrToInt(wrapper, c.uintptrType),
+			llvm.ConstPtrToInt(fn, c.uintptrType),
 		})
 		methods[i] = methodInfo
 	}
@@ -271,7 +264,7 @@ func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 	global = llvm.AddGlobal(c.mod, arrayType, typ.String()+"$methodset")
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
-	global.SetLinkage(llvm.LinkOnceODRLinkage)
+	global.SetLinkage(llvm.PrivateLinkage)
 	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }

@@ -302,7 +295,7 @@ func (c *compilerContext) getInterfaceMethodSet(typ types.Type) llvm.Value {
 	global = llvm.AddGlobal(c.mod, value.Type(), name+"$interface")
 	global.SetInitializer(value)
 	global.SetGlobalConstant(true)
-	global.SetLinkage(llvm.LinkOnceODRLinkage)
+	global.SetLinkage(llvm.PrivateLinkage)
 	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }

@@ -310,7 +303,7 @@ func (c *compilerContext) getInterfaceMethodSet(typ types.Type) llvm.Value {
 // external *i8 indicating the indicating the signature of this method. It is
 // used during the interface lowering pass.
 func (c *compilerContext) getMethodSignature(method *types.Func) llvm.Value {
-	signature := methodSignature(method)
+	signature := ir.MethodSignature(method)
 	signatureGlobal := c.mod.NamedGlobal("func " + signature)
 	if signatureGlobal.IsNil() {
 		signatureGlobal = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), "func "+signature)
@@ -345,16 +338,10 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 		commaOk = b.createRuntimeCall("interfaceImplements", []llvm.Value{actualTypeNum, methodSet}, "")

 	} else {
-		globalName := "reflect/types.typeid:" + getTypeCodeName(expr.AssertedType)
-		assertedTypeCodeGlobal := b.mod.NamedGlobal(globalName)
-		if assertedTypeCodeGlobal.IsNil() {
-			// Create a new typecode global.
-			assertedTypeCodeGlobal = llvm.AddGlobal(b.mod, b.ctx.Int8Type(), globalName)
-			assertedTypeCodeGlobal.SetGlobalConstant(true)
-		}
 		// Type assert on concrete type.
 		// Call runtime.typeAssert, which will be lowered to a simple icmp or
 		// const false in the interface lowering pass.
+		assertedTypeCodeGlobal := b.getTypeCode(expr.AssertedType)
 		commaOk = b.createRuntimeCall("typeAssert", []llvm.Value{actualTypeNum, assertedTypeCodeGlobal}, "typecode")
 	}

@@ -370,8 +357,8 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 	// value.

 	prevBlock := b.GetInsertBlock()
-	okBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.ok")
-	nextBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.next")
+	okBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, "typeassert.ok")
+	nextBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, "typeassert.next")
 	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
 	b.CreateCondBr(commaOk, okBlock, nextBlock)

@@ -449,8 +436,8 @@ func (b *builder) getInvokeCall(instr *ssa.CallCommon) (llvm.Value, []llvm.Value
 // value, dereferences or unpacks it if necessary, and calls the real method.
 // If the method to wrap has a pointer receiver, no wrapping is necessary and
 // the function is returned directly.
-func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llvm.Value) llvm.Value {
-	wrapperName := llvmFn.Name() + "$invoke"
+func (c *compilerContext) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
+	wrapperName := f.LinkName() + "$invoke"
 	wrapper := c.mod.NamedFunction(wrapperName)
 	if !wrapper.IsNil() {
 		// Wrapper already created. Return it directly.
@@ -458,9 +445,9 @@ func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llv
 	}

 	// Get the expanded receiver type.
-	receiverType := c.getLLVMType(fn.Signature.Recv().Type())
+	receiverType := c.getLLVMType(f.Params[0].Type())
 	var expandedReceiverType []llvm.Type
-	for _, info := range c.expandFormalParamType(receiverType, "", nil) {
+	for _, info := range expandFormalParamType(receiverType, "", nil) {
 		expandedReceiverType = append(expandedReceiverType, info.llvmType)
 	}

@@ -470,17 +457,19 @@ func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llv
 		// 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 llvmFn
+		return f.LLVMFn
 	}

 	// create wrapper function
-	fnType := llvmFn.Type().ElementType()
+	fnType := f.LLVMFn.Type().ElementType()
 	paramTypes := append([]llvm.Type{c.i8ptrType}, fnType.ParamTypes()[len(expandedReceiverType):]...)
 	wrapFnType := llvm.FunctionType(fnType.ReturnType(), paramTypes, false)
 	wrapper = llvm.AddFunction(c.mod, wrapperName, wrapFnType)
-	wrapper.LastParam().SetName("parentHandle")
+	if f.LLVMFn.LastParam().Name() == "parentHandle" {
+		wrapper.LastParam().SetName("parentHandle")
+	}

-	wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
+	wrapper.SetLinkage(llvm.InternalLinkage)
 	wrapper.SetUnnamedAddr(true)

 	// Create a new builder just to create this wrapper.
@@ -491,9 +480,9 @@ func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llv
 	defer b.Builder.Dispose()

 	// add debug info if needed
-	if c.Debug {
-		pos := c.program.Fset.Position(fn.Pos())
-		difunc := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
+	if c.Debug() {
+		pos := c.ir.Program.Fset.Position(f.Pos())
+		difunc := c.attachDebugInfoRaw(f, wrapper, "$invoke", pos.Filename, pos.Line)
 		b.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 	}

@@ -503,60 +492,13 @@ func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llv

 	receiverValue := b.emitPointerUnpack(wrapper.Param(0), []llvm.Type{receiverType})[0]
 	params := append(b.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
-	if llvmFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
-		b.CreateCall(llvmFn, params, "")
+	if f.LLVMFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
+		b.CreateCall(f.LLVMFn, params, "")
 		b.CreateRetVoid()
 	} else {
-		ret := b.CreateCall(llvmFn, params, "ret")
+		ret := b.CreateCall(f.LLVMFn, params, "ret")
 		b.CreateRet(ret)
 	}

 	return wrapper
 }
-
-// methodSignature creates a readable version of a method signature (including
-// the function name, excluding the receiver name). This string is used
-// internally to match interfaces and to call the correct method on an
-// interface. Examples:
-//
-//     String() string
-//     Read([]byte) (int, error)
-func methodSignature(method *types.Func) string {
-	return method.Name() + signature(method.Type().(*types.Signature))
-}
-
-// Make a readable version of a function (pointer) signature.
-// Examples:
-//
-//     () string
-//     (string, int) (int, error)
-func signature(sig *types.Signature) string {
-	s := ""
-	if sig.Params().Len() == 0 {
-		s += "()"
-	} else {
-		s += "("
-		for i := 0; i < sig.Params().Len(); i++ {
-			if i > 0 {
-				s += ", "
-			}
-			s += sig.Params().At(i).Type().String()
-		}
-		s += ")"
-	}
-	if sig.Results().Len() == 0 {
-		// keep as-is
-	} else if sig.Results().Len() == 1 {
-		s += " " + sig.Results().At(0).Type().String()
-	} else {
-		s += " ("
-		for i := 0; i < sig.Results().Len(); i++ {
-			if i > 0 {
-				s += ", "
-			}
-			s += sig.Results().At(i).Type().String()
-		}
-		s += ")"
-	}
-	return s
-}
@@ -39,14 +39,14 @@ func (b *builder) createInterruptGlobal(instr *ssa.CallCommon) (llvm.Value, erro

 	// Create a new global of type runtime/interrupt.handle. Globals of this
 	// type are lowered in the interrupt lowering pass.
-	globalType := b.program.ImportedPackage("runtime/interrupt").Type("handle").Type()
+	globalType := b.ir.Program.ImportedPackage("runtime/interrupt").Type("handle").Type()
 	globalLLVMType := b.getLLVMType(globalType)
 	globalName := "runtime/interrupt.$interrupt" + strconv.FormatInt(id.Int64(), 10)
 	if global := b.mod.NamedGlobal(globalName); !global.IsNil() {
 		return llvm.Value{}, b.makeError(instr.Pos(), "interrupt redeclared in this program")
 	}
 	global := llvm.AddGlobal(b.mod, globalLLVMType, globalName)
-	global.SetVisibility(llvm.HiddenVisibility)
+	global.SetLinkage(llvm.PrivateLinkage)
 	global.SetGlobalConstant(true)
 	global.SetUnnamedAddr(true)
 	initializer := llvm.ConstNull(globalLLVMType)
@@ -55,8 +55,8 @@ func (b *builder) createInterruptGlobal(instr *ssa.CallCommon) (llvm.Value, erro
 	global.SetInitializer(initializer)

 	// Add debug info to the interrupt global.
-	if b.Debug {
-		pos := b.program.Fset.Position(instr.Pos())
+	if b.Debug() {
+		pos := b.ir.Program.Fset.Position(instr.Pos())
 		diglobal := b.dibuilder.CreateGlobalVariableExpression(b.getDIFile(pos.Filename), llvm.DIGlobalVariableExpression{
 			Name:        "interrupt" + strconv.FormatInt(id.Int64(), 10),
 			LinkageName: globalName,
@@ -79,7 +79,7 @@ func (b *builder) createInterruptGlobal(instr *ssa.CallCommon) (llvm.Value, erro
 	// 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(b.Triple, "avr") {
+	if strings.HasPrefix(b.Triple(), "avr") {
 		useFn := b.mod.NamedFunction("runtime/interrupt.use")
 		if useFn.IsNil() {
 			useFnType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{interrupt.Type()}, false)
@@ -44,7 +44,7 @@ func (b *builder) emitLifetimeEnd(ptr, size llvm.Value) {
 // 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 (b *builder) emitPointerPack(values []llvm.Value) llvm.Value {
-	return llvmutil.EmitPointerPack(b.Builder, b.mod, b.NeedsStackObjects, values)
+	return llvmutil.EmitPointerPack(b.Builder, b.mod, b.Config, values)
 }

 // emitPointerUnpack extracts a list of values packed using emitPointerPack.
@@ -5,6 +5,7 @@ package llvmutil
 // itself if possible and legal.

 import (
+	"github.com/tinygo-org/tinygo/compileopts"
 	"tinygo.org/x/go-llvm"
 )

@@ -12,7 +13,7 @@ import (
 // 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.
 // If the values are all constants, they are be stored in a constant global and deduplicated.
-func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bool, values []llvm.Value) llvm.Value {
+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)
@@ -25,6 +26,7 @@ func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bo
 	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)
@@ -37,39 +39,9 @@ func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bo
 			// 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 a *i8 alloca first and load the *i8 value from there. This is
-		// effectively a bitcast.
-		packedAlloc, _, _ := CreateTemporaryAlloca(builder, mod, i8ptrType, "")
-
-		if size < targetData.TypeAllocSize(i8ptrType) {
-			// The alloca is bigger than the value that will be stored in it.
-			// To avoid having some bits undefined, zero the alloca first.
-			// Hopefully this will get optimized away.
-			builder.CreateStore(llvm.ConstNull(i8ptrType), packedAlloc)
-		}
-
-		// Store all values in the alloca.
-		packedAllocCast := builder.CreateBitCast(packedAlloc, llvm.PointerType(packedType, 0), "")
-		for i, value := range values {
-			indices := []llvm.Value{
-				llvm.ConstInt(ctx.Int32Type(), 0, false),
-				llvm.ConstInt(ctx.Int32Type(), uint64(i), false),
-			}
-			gep := builder.CreateInBoundsGEP(packedAllocCast, indices, "")
-			builder.CreateStore(value, gep)
-		}
-
-		// Load value (the *i8) from the alloca.
-		result := builder.CreateLoad(packedAlloc, "")
-
-		// End the lifetime of the alloca, to help the optimizer.
-		packedPtr := builder.CreateBitCast(packedAlloc, i8ptrType, "")
-		packedSize := llvm.ConstInt(ctx.Int64Type(), targetData.TypeAllocSize(packedAlloc.Type()), false)
-		EmitLifetimeEnd(builder, mod, packedPtr, packedSize)
-
-		return result
+		// it in an alloca first for bitcasting (store+bitcast+load).
+		packedAlloc, _, _ = CreateTemporaryAlloca(builder, mod, packedType, "")
 	} else {
 		// Check if the values are all constants.
 		constant := true
@@ -95,12 +67,12 @@ func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bo
 		// 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{
+		packedHeapAlloc = builder.CreateCall(alloc, []llvm.Value{
 			sizeValue,
 			llvm.Undef(i8ptrType),            // unused context parameter
 			llvm.ConstPointerNull(i8ptrType), // coroutine handle
 		}, "")
-		if needsStackObjects {
+		if config.NeedsStackObjects() {
 			trackPointer := mod.NamedFunction("runtime.trackPointer")
 			builder.CreateCall(trackPointer, []llvm.Value{
 				packedHeapAlloc,
@@ -108,19 +80,28 @@ func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bo
 				llvm.ConstPointerNull(i8ptrType), // coroutine handle
 			}, "")
 		}
-		packedAlloc := builder.CreateBitCast(packedHeapAlloc, llvm.PointerType(packedType, 0), "")
-
-		// Store all values in the 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)
+		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)
+	}

-		// Return the original heap allocation pointer, which already is an *i8.
+	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
 	}
 }
@@ -150,9 +150,6 @@ func (s *stdSizes) Sizeof(T types.Type) int64 {
 		return s.PtrSize * 2
 	case *types.Pointer:
 		return s.PtrSize
-	case *types.Signature:
-		// Func values in TinyGo are two words in size.
-		return s.PtrSize * 2
 	default:
 		panic("unknown type: " + t.String())
 	}
@@ -15,309 +15,6 @@ import (
 	"tinygo.org/x/go-llvm"
 )

-// functionInfo contains some information about a function or method. In
-// particular, it contains information obtained from pragmas.
-//
-// The linkName value contains a valid link name, even if //go:linkname is not
-// present.
-type functionInfo struct {
-	module     string     // go:wasm-module
-	importName string     // go:linkname, go:export - The name the developer assigns
-	linkName   string     // go:linkname, go:export - The name that we map for the particular module -> importName
-	exported   bool       // go:export, CGo
-	nobounds   bool       // go:nobounds
-	variadic   bool       // go:variadic (CGo only)
-	inline     inlineType // go:inline
-}
-
-type inlineType int
-
-// How much to inline.
-const (
-	// Default behavior. The compiler decides for itself whether any given
-	// function will be inlined. Whether any function is inlined depends on the
-	// optimization level.
-	inlineDefault inlineType = iota
-
-	// Inline hint, just like the C inline keyword (signalled using
-	// //go:inline). The compiler will be more likely to inline this function,
-	// but it is not a guarantee.
-	inlineHint
-
-	// Don't inline, just like the GCC noinline attribute. Signalled using
-	// //go:noinline.
-	inlineNone
-)
-
-// getFunction returns the LLVM function for the given *ssa.Function, creating
-// it if needed. It can later be filled with compilerContext.createFunction().
-func (c *compilerContext) getFunction(fn *ssa.Function) llvm.Value {
-	info := c.getFunctionInfo(fn)
-	llvmFn := c.mod.NamedFunction(info.linkName)
-	if !llvmFn.IsNil() {
-		return llvmFn
-	}
-
-	var retType llvm.Type
-	if fn.Signature.Results() == nil {
-		retType = c.ctx.VoidType()
-	} else if fn.Signature.Results().Len() == 1 {
-		retType = c.getLLVMType(fn.Signature.Results().At(0).Type())
-	} else {
-		results := make([]llvm.Type, 0, fn.Signature.Results().Len())
-		for i := 0; i < fn.Signature.Results().Len(); i++ {
-			results = append(results, c.getLLVMType(fn.Signature.Results().At(i).Type()))
-		}
-		retType = c.ctx.StructType(results, false)
-	}
-
-	var paramInfos []paramInfo
-	for _, param := range getParams(fn.Signature) {
-		paramType := c.getLLVMType(param.Type())
-		paramFragmentInfos := c.expandFormalParamType(paramType, param.Name(), param.Type())
-		paramInfos = append(paramInfos, paramFragmentInfos...)
-	}
-
-	// Add an extra parameter as the function context. This context is used in
-	// closures and bound methods, but should be optimized away when not used.
-	if !info.exported {
-		paramInfos = append(paramInfos, paramInfo{llvmType: c.i8ptrType, name: "context", flags: 0})
-		paramInfos = append(paramInfos, paramInfo{llvmType: c.i8ptrType, name: "parentHandle", flags: 0})
-	}
-
-	var paramTypes []llvm.Type
-	for _, info := range paramInfos {
-		paramTypes = append(paramTypes, info.llvmType)
-	}
-
-	fnType := llvm.FunctionType(retType, paramTypes, info.variadic)
-	llvmFn = llvm.AddFunction(c.mod, info.linkName, fnType)
-	if strings.HasPrefix(c.Triple, "wasm") {
-		// C functions without prototypes like this:
-		//   void foo();
-		// are actually variadic functions. However, it appears that it has been
-		// decided in WebAssembly that such prototype-less functions are not
-		// allowed in WebAssembly.
-		// In C, this can only happen when there are zero parameters, hence this
-		// check here. For more information:
-		// https://reviews.llvm.org/D48443
-		// https://github.com/WebAssembly/tool-conventions/issues/16
-		if info.variadic && len(fn.Params) == 0 {
-			attr := c.ctx.CreateStringAttribute("no-prototype", "")
-			llvmFn.AddFunctionAttr(attr)
-		}
-	}
-
-	dereferenceableOrNullKind := llvm.AttributeKindID("dereferenceable_or_null")
-	for i, info := range paramInfos {
-		if info.flags&paramIsDeferenceableOrNull == 0 {
-			continue
-		}
-		if info.llvmType.TypeKind() == llvm.PointerTypeKind {
-			el := info.llvmType.ElementType()
-			size := c.targetData.TypeAllocSize(el)
-			if size == 0 {
-				// dereferenceable_or_null(0) appears to be illegal in LLVM.
-				continue
-			}
-			dereferenceableOrNull := c.ctx.CreateEnumAttribute(dereferenceableOrNullKind, size)
-			llvmFn.AddAttributeAtIndex(i+1, dereferenceableOrNull)
-		}
-	}
-
-	// Set a number of function or parameter attributes, depending on the
-	// function. These functions are runtime functions that are known to have
-	// certain attributes that might not be inferred by the compiler.
-	switch info.linkName {
-	case "abort":
-		// On *nix systems, the "abort" functuion in libc is used to handle fatal panics.
-		// Mark it as noreturn so LLVM can optimize away code.
-		llvmFn.AddFunctionAttr(c.ctx.CreateEnumAttribute(llvm.AttributeKindID("noreturn"), 0))
-	case "runtime.alloc":
-		// Tell the optimizer that runtime.alloc is an allocator, meaning that it
-		// returns values that are never null and never alias to an existing value.
-		for _, attrName := range []string{"noalias", "nonnull"} {
-			llvmFn.AddAttributeAtIndex(0, c.ctx.CreateEnumAttribute(llvm.AttributeKindID(attrName), 0))
-		}
-	case "runtime.sliceAppend":
-		// Appending a slice will only read the to-be-appended slice, it won't
-		// be modified.
-		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
-		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
-	case "runtime.sliceCopy":
-		// Copying a slice won't capture any of the parameters.
-		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("writeonly"), 0))
-		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
-		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
-		llvmFn.AddAttributeAtIndex(2, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
-	case "runtime.trackPointer":
-		// This function is necessary for tracking pointers on the stack in a
-		// portable way (see gc_stack_portable.go). Indicate to the optimizer
-		// that the only thing we'll do is read the pointer.
-		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
-		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0))
-	}
-
-	// External/exported functions may not retain pointer values.
-	// https://golang.org/cmd/cgo/#hdr-Passing_pointers
-	if info.exported {
-		// Set the wasm-import-module attribute if the function's module is set.
-		if info.module != "" {
-
-			// We need to add the wasm-import-module and the wasm-import-name
-			wasmImportModuleAttr := c.ctx.CreateStringAttribute("wasm-import-module", info.module)
-			llvmFn.AddFunctionAttr(wasmImportModuleAttr)
-
-			// Add the Wasm Import Name, if we are a named wasm import
-			if info.importName != "" {
-				wasmImportNameAttr := c.ctx.CreateStringAttribute("wasm-import-name", info.importName)
-				llvmFn.AddFunctionAttr(wasmImportNameAttr)
-			}
-		}
-		nocaptureKind := llvm.AttributeKindID("nocapture")
-		nocapture := c.ctx.CreateEnumAttribute(nocaptureKind, 0)
-		for i, typ := range paramTypes {
-			if typ.TypeKind() == llvm.PointerTypeKind {
-				llvmFn.AddAttributeAtIndex(i+1, nocapture)
-			}
-		}
-	}
-
-	// Synthetic functions are functions that do not appear in the source code,
-	// they are artificially constructed. Usually they are wrapper functions
-	// that are not referenced anywhere except in a SSA call instruction so
-	// should be created right away.
-	// The exception is the package initializer, which does appear in the
-	// *ssa.Package members and so shouldn't be created here.
-	if fn.Synthetic != "" && fn.Synthetic != "package initializer" {
-		irbuilder := c.ctx.NewBuilder()
-		b := newBuilder(c, irbuilder, fn)
-		b.createFunction()
-		irbuilder.Dispose()
-		llvmFn.SetLinkage(llvm.LinkOnceODRLinkage)
-		llvmFn.SetUnnamedAddr(true)
-	}
-
-	return llvmFn
-}
-
-// getFunctionInfo returns information about a function that is not directly
-// present in *ssa.Function, such as the link name and whether it should be
-// exported.
-func (c *compilerContext) getFunctionInfo(f *ssa.Function) functionInfo {
-	info := functionInfo{}
-	if strings.HasPrefix(f.Name(), "C.") {
-		// Created by CGo: such a name cannot be created by regular C code.
-		info.linkName = f.Name()[2:]
-		info.exported = true
-	} else {
-		// Pick the default linkName.
-		info.linkName = f.RelString(nil)
-	}
-	// Check for //go: pragmas, which may change the link name (among others).
-	info.parsePragmas(f)
-	return info
-}
-
-// parsePragmas is used by getFunctionInfo to parse function pragmas such as
-// //export or //go:noinline.
-func (info *functionInfo) parsePragmas(f *ssa.Function) {
-	if f.Syntax() == nil {
-		return
-	}
-	if decl, ok := f.Syntax().(*ast.FuncDecl); ok && decl.Doc != nil {
-
-		// Our importName for a wasm module (if we are compiling to wasm), or llvm link name
-		var importName string
-
-		for _, comment := range decl.Doc.List {
-			text := comment.Text
-			if strings.HasPrefix(text, "//export ") {
-				// Rewrite '//export' to '//go:export' for compatibility with
-				// gc.
-				text = "//go:" + text[2:]
-			}
-			if !strings.HasPrefix(text, "//go:") {
-				continue
-			}
-			parts := strings.Fields(text)
-			switch parts[0] {
-			case "//go:export":
-				if len(parts) != 2 {
-					continue
-				}
-
-				importName = parts[1]
-				info.exported = true
-			case "//go:wasm-module":
-				// Alternative comment for setting the import module.
-				if len(parts) != 2 {
-					continue
-				}
-				info.module = parts[1]
-			case "//go:inline":
-				info.inline = inlineHint
-			case "//go:noinline":
-				info.inline = inlineNone
-			case "//go:linkname":
-				if len(parts) != 3 || parts[1] != f.Name() {
-					continue
-				}
-				// Only enable go:linkname when the package imports "unsafe".
-				// This is a slightly looser requirement than what gc uses: gc
-				// requires the file to import "unsafe", not the package as a
-				// whole.
-				if hasUnsafeImport(f.Pkg.Pkg) {
-					info.linkName = parts[2]
-				}
-			case "//go:nobounds":
-				// Skip bounds checking in this function. Useful for some
-				// runtime functions.
-				// This is somewhat dangerous and thus only imported in packages
-				// that import unsafe.
-				if hasUnsafeImport(f.Pkg.Pkg) {
-					info.nobounds = true
-				}
-			case "//go:variadic":
-				// The //go:variadic pragma is emitted by the CGo preprocessing
-				// pass for C variadic functions. This includes both explicit
-				// (with ...) and implicit (no parameters in signature)
-				// functions.
-				if strings.HasPrefix(f.Name(), "C.") {
-					// This prefix cannot naturally be created, it must have
-					// been created as a result of CGo preprocessing.
-					info.variadic = true
-				}
-			}
-		}
-
-		// Set the importName for our exported function if we have one
-		if importName != "" {
-			if info.module == "" {
-				info.linkName = importName
-			} else {
-				// WebAssembly import
-				info.importName = importName
-			}
-		}
-
-	}
-}
-
-// getParams returns the function parameters, including the receiver at the
-// start. This is an alternative to the Params member of *ssa.Function, which is
-// not yet populated when the package has not yet been built.
-func getParams(sig *types.Signature) []*types.Var {
-	params := []*types.Var{}
-	if sig.Recv() != nil {
-		params = append(params, sig.Recv())
-	}
-	for i := 0; i < sig.Params().Len(); i++ {
-		params = append(params, sig.Params().At(i))
-	}
-	return params
-}
-
 // 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).
@@ -329,22 +26,25 @@ type globalInfo struct {

 // 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 *compilerContext) loadASTComments(pkg *loader.Package) {
-	for _, file := range pkg.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 := pkg.Pkg.Path() + "." + name.Name
-								c.astComments[id] = decl.Doc
+func (c *compilerContext) 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
+								}
 							}
 						}
 					}
@@ -363,26 +63,30 @@ func (c *compilerContext) getGlobal(g *ssa.Global) llvm.Value {
 		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
-		alignment := c.targetData.ABITypeAlignment(llvmType)
-		if info.align > alignment {
-			alignment = info.align
-		}
-		if alignment <= 0 || alignment&(alignment-1) != 0 {
+		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(alignment) ^ uint32(alignment-1)
-			llvmGlobal.SetAlignment(alignment)
+			alignInBits = uint32(info.align) ^ uint32(info.align-1)
+			if info.align > c.targetData.ABITypeAlignment(llvmType) {
+				llvmGlobal.SetAlignment(info.align)
+			}
 		}

-		if c.Debug && !info.extern {
+		if c.Debug() && !info.extern {
 			// Add debug info.
-			pos := c.program.Fset.Position(g.Pos())
+			// 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,
@@ -441,23 +145,3 @@ func (info *globalInfo) parsePragmas(doc *ast.CommentGroup) {
 		}
 	}
 }
-
-// Get all methods of a type.
-func getAllMethods(prog *ssa.Program, typ types.Type) []*types.Selection {
-	ms := prog.MethodSets.MethodSet(typ)
-	methods := make([]*types.Selection, ms.Len())
-	for i := 0; i < ms.Len(); i++ {
-		methods[i] = ms.At(i)
-	}
-	return methods
-}
-
-// Return true if this package imports "unsafe", false otherwise.
-func hasUnsafeImport(pkg *types.Package) bool {
-	for _, imp := range pkg.Imports() {
-		if imp == types.Unsafe {
-			return true
-		}
-	}
-	return false
-}
@@ -16,8 +16,8 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 	num := b.getValue(call.Args[0])
 	var syscallResult llvm.Value
 	switch {
-	case b.GOARCH == "amd64":
-		if b.GOOS == "darwin" {
+	case b.GOARCH() == "amd64":
+		if b.GOOS() == "darwin" {
 			// Darwin adds this magic number to system call numbers:
 			//
 			// > Syscall classes for 64-bit system call entry.
@@ -58,7 +58,7 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
 		target := llvm.InlineAsm(fnType, "syscall", constraints, true, false, llvm.InlineAsmDialectIntel)
 		syscallResult = b.CreateCall(target, args, "")
-	case b.GOARCH == "386" && b.GOOS == "linux":
+	case b.GOARCH() == "386" && b.GOOS() == "linux":
 		// Sources:
 		//   syscall(2) man page
 		//   https://stackoverflow.com/a/2538212
@@ -84,7 +84,7 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
 		target := llvm.InlineAsm(fnType, "int 0x80", constraints, true, false, llvm.InlineAsmDialectIntel)
 		syscallResult = b.CreateCall(target, args, "")
-	case b.GOARCH == "arm" && b.GOOS == "linux":
+	case b.GOARCH() == "arm" && b.GOOS() == "linux":
 		// Implement the EABI system call convention for Linux.
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}
@@ -116,7 +116,7 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
 		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
 		syscallResult = b.CreateCall(target, args, "")
-	case b.GOARCH == "arm64" && b.GOOS == "linux":
+	case b.GOARCH() == "arm64" && b.GOOS() == "linux":
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}
 		argTypes := []llvm.Type{}
@@ -149,9 +149,9 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0)
 		syscallResult = b.CreateCall(target, args, "")
 	default:
-		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
+		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS()+"/"+b.GOARCH())
 	}
-	switch b.GOOS {
+	switch b.GOOS() {
 	case "linux", "freebsd":
 		// Return values: r0, r1 uintptr, err Errno
 		// Pseudocode:
@@ -187,6 +187,6 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		retval = b.CreateInsertValue(retval, errResult, 2, "")
 		return retval, nil
 	default:
-		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
+		return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS()+"/"+b.GOARCH())
 	}
 }
@@ -1,57 +0,0 @@
-package main
-
-// Basic tests that don't need to be split into a separate file.
-
-func addInt(x, y int) int {
-	return x + y
-}
-
-func equalInt(x, y int) bool {
-	return x == y
-}
-
-func floatEQ(x, y float32) bool {
-	return x == y
-}
-
-func floatNE(x, y float32) bool {
-	return x != y
-}
-
-func floatLower(x, y float32) bool {
-	return x < y
-}
-
-func floatLowerEqual(x, y float32) bool {
-	return x <= y
-}
-
-func floatGreater(x, y float32) bool {
-	return x > y
-}
-
-func floatGreaterEqual(x, y float32) bool {
-	return x >= y
-}
-
-func complexReal(x complex64) float32 {
-	return real(x)
-}
-
-func complexImag(x complex64) float32 {
-	return imag(x)
-}
-
-func complexAdd(x, y complex64) complex64 {
-	return x + y
-}
-
-func complexSub(x, y complex64) complex64 {
-	return x - y
-}
-
-func complexMul(x, y complex64) complex64 {
-	return x * y
-}
-
-// TODO: complexDiv (requires runtime call)
@@ -1,100 +0,0 @@
-; ModuleID = 'basic.go'
-source_filename = "basic.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden i32 @main.addInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = add i32 %x, %y
-  ret i32 %0
-}
-
-define hidden i1 @main.equalInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = icmp eq i32 %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatEQ(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp oeq float %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatNE(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp une float %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatLower(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp olt float %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatLowerEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp ole float %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatGreater(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp ogt float %x, %y
-  ret i1 %0
-}
-
-define hidden i1 @main.floatGreaterEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fcmp oge float %x, %y
-  ret i1 %0
-}
-
-define hidden float @main.complexReal(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret float %x.r
-}
-
-define hidden float @main.complexImag(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret float %x.i
-}
-
-define hidden { float, float } @main.complexAdd(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fadd float %x.r, %y.r
-  %1 = fadd float %x.i, %y.i
-  %2 = insertvalue { float, float } undef, float %0, 0
-  %3 = insertvalue { float, float } %2, float %1, 1
-  ret { float, float } %3
-}
-
-define hidden { float, float } @main.complexSub(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fsub float %x.r, %y.r
-  %1 = fsub float %x.i, %y.i
-  %2 = insertvalue { float, float } undef, float %0, 0
-  %3 = insertvalue { float, float } %2, float %1, 1
-  ret { float, float } %3
-}
-
-define hidden { float, float } @main.complexMul(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = fmul float %x.r, %y.r
-  %1 = fmul float %x.i, %y.i
-  %2 = fsub float %0, %1
-  %3 = fmul float %x.r, %y.i
-  %4 = fmul float %x.i, %y.r
-  %5 = fadd float %3, %4
-  %6 = insertvalue { float, float } undef, float %2, 0
-  %7 = insertvalue { float, float } %6, float %5, 1
-  ret { float, float } %7
-}
@@ -1,39 +0,0 @@
-package main
-
-// Test converting floats to ints.
-
-func f32tou32(v float32) uint32 {
-	return uint32(v)
-}
-
-func maxu32f() float32 {
-	return float32(^uint32(0))
-}
-
-func maxu32tof32() uint32 {
-	f := float32(^uint32(0))
-	return uint32(f)
-}
-
-func inftoi32() (uint32, uint32, int32, int32) {
-	inf := 1.0
-	inf /= 0.0
-
-	return uint32(inf), uint32(-inf), int32(inf), int32(-inf)
-}
-
-func u32tof32tou32(v uint32) uint32 {
-	return uint32(float32(v))
-}
-
-func f32tou32tof32(v float32) float32 {
-	return float32(uint32(v))
-}
-
-func f32tou8(v float32) uint8 {
-	return uint8(v)
-}
-
-func f32toi8(v float32) int8 {
-	return int8(v)
-}
@@ -1,82 +0,0 @@
-; ModuleID = 'float.go'
-source_filename = "float.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden i32 @main.f32tou32(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %positive = fcmp oge float %v, 0.000000e+00
-  %withinmax = fcmp ole float %v, 0x41EFFFFFC0000000
-  %inbounds = and i1 %positive, %withinmax
-  %saturated = sext i1 %positive to i32
-  %normal = fptoui float %v to i32
-  %0 = select i1 %inbounds, i32 %normal, i32 %saturated
-  ret i32 %0
-}
-
-define hidden float @main.maxu32f(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret float 0x41F0000000000000
-}
-
-define hidden i32 @main.maxu32tof32(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret i32 -1
-}
-
-define hidden { i32, i32, i32, i32 } @main.inftoi32(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret { i32, i32, i32, i32 } { i32 -1, i32 0, i32 2147483647, i32 -2147483648 }
-}
-
-define hidden i32 @main.u32tof32tou32(i32 %v, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = uitofp i32 %v to float
-  %withinmax = fcmp ole float %0, 0x41EFFFFFC0000000
-  %normal = fptoui float %0 to i32
-  %1 = select i1 %withinmax, i32 %normal, i32 -1
-  ret i32 %1
-}
-
-define hidden float @main.f32tou32tof32(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %positive = fcmp oge float %v, 0.000000e+00
-  %withinmax = fcmp ole float %v, 0x41EFFFFFC0000000
-  %inbounds = and i1 %positive, %withinmax
-  %saturated = sext i1 %positive to i32
-  %normal = fptoui float %v to i32
-  %0 = select i1 %inbounds, i32 %normal, i32 %saturated
-  %1 = uitofp i32 %0 to float
-  ret float %1
-}
-
-define hidden i8 @main.f32tou8(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %positive = fcmp oge float %v, 0.000000e+00
-  %withinmax = fcmp ole float %v, 2.550000e+02
-  %inbounds = and i1 %positive, %withinmax
-  %saturated = sext i1 %positive to i8
-  %normal = fptoui float %v to i8
-  %0 = select i1 %inbounds, i8 %normal, i8 %saturated
-  ret i8 %0
-}
-
-define hidden i8 @main.f32toi8(float %v, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %abovemin = fcmp oge float %v, -1.280000e+02
-  %belowmax = fcmp ole float %v, 1.270000e+02
-  %inbounds = and i1 %abovemin, %belowmax
-  %saturated = select i1 %abovemin, i8 127, i8 -128
-  %isnan = fcmp uno float %v, 0.000000e+00
-  %remapped = select i1 %isnan, i8 0, i8 %saturated
-  %normal = fptosi float %v to i8
-  %0 = select i1 %inbounds, i8 %normal, i8 %remapped
-  ret i8 %0
-}
@@ -1,12 +0,0 @@
-package main
-
-func foo(callback func(int)) {
-	callback(3)
-}
-
-func bar() {
-	foo(someFunc)
-}
-
-func someFunc(int) {
-}
@@ -1,47 +0,0 @@
-; ModuleID = 'func.go'
-source_filename = "func.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-%runtime.funcValueWithSignature = type { i32, i8* }
-
-@"reflect/types.funcid:func:{basic:int}{}" = external constant i8
-@"main.someFunc$withSignature" = linkonce_odr constant %runtime.funcValueWithSignature { i32 ptrtoint (void (i32, i8*, i8*)* @main.someFunc to i32), i8* @"reflect/types.funcid:func:{basic:int}{}" }
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden void @main.foo(i8* %callback.context, i32 %callback.funcptr, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i32 @runtime.getFuncPtr(i8* %callback.context, i32 %callback.funcptr, i8* nonnull @"reflect/types.funcid:func:{basic:int}{}", i8* undef, i8* null)
-  %1 = icmp eq i32 %0, 0
-  br i1 %1, label %fpcall.throw, label %fpcall.next
-
-fpcall.throw:                                     ; preds = %entry
-  call void @runtime.nilPanic(i8* undef, i8* null)
-  unreachable
-
-fpcall.next:                                      ; preds = %entry
-  %2 = inttoptr i32 %0 to void (i32, i8*, i8*)*
-  call void %2(i32 3, i8* %callback.context, i8* undef)
-  ret void
-}
-
-declare i32 @runtime.getFuncPtr(i8*, i32, i8* dereferenceable_or_null(1), i8*, i8*)
-
-declare void @runtime.nilPanic(i8*, i8*)
-
-define hidden void @main.bar(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  call void @main.foo(i8* undef, i32 ptrtoint (%runtime.funcValueWithSignature* @"main.someFunc$withSignature" to i32), i8* undef, i8* undef)
-  ret void
-}
-
-define hidden void @main.someFunc(i32 %arg0, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
@@ -1,54 +0,0 @@
-// This file tests interface types and interface builtins.
-
-package main
-
-// Test interface construction.
-
-func simpleType() interface{} {
-	return 0
-}
-
-func pointerType() interface{} {
-	// Pointers have an element type, in this case int.
-	var v *int
-	return v
-}
-
-func interfaceType() interface{} {
-	// Interfaces can exist in interfaces, but only indirectly (through
-	// pointers).
-	var v *error
-	return v
-}
-
-func anonymousInterfaceType() interface{} {
-	var v *interface {
-		String() string
-	}
-	return v
-}
-
-// Test interface builtins.
-
-func isInt(itf interface{}) bool {
-	_, ok := itf.(int)
-	return ok
-}
-
-func isError(itf interface{}) bool {
-	// Interface assert on (builtin) named interface type.
-	_, ok := itf.(error)
-	return ok
-}
-
-func isStringer(itf interface{}) bool {
-	// Interface assert on anonymous interface type.
-	_, ok := itf.(interface {
-		String() string
-	})
-	return ok
-}
-
-func callErrorMethod(itf error) string {
-	return itf.Error()
-}
@@ -1,101 +0,0 @@
-; ModuleID = 'interface.go'
-source_filename = "interface.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-%runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo*, %runtime.typecodeID* }
-%runtime.interfaceMethodInfo = type { i8*, i32 }
-%runtime._interface = type { i32, i8* }
-%runtime._string = type { i8*, i32 }
-
-@"reflect/types.type:basic:int" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* null, i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* @"reflect/types.type:pointer:basic:int" }
-@"reflect/types.type:pointer:basic:int" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* null }
-@"reflect/types.type:pointer:named:error" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:named:error", i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* null }
-@"reflect/types.type:named:error" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:interface:{Error:func:{}{basic:string}}", i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* @"reflect/types.type:pointer:named:error" }
-@"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* bitcast ([1 x i8*]* @"reflect/types.interface:interface{Error() string}$interface" to %runtime.typecodeID*), i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" }
-@"func Error() string" = external constant i8
-@"reflect/types.interface:interface{Error() string}$interface" = linkonce_odr constant [1 x i8*] [i8* @"func Error() string"]
-@"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:interface:{Error:func:{}{basic:string}}", i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* null }
-@"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:interface:{String:func:{}{basic:string}}", i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* null }
-@"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* bitcast ([1 x i8*]* @"reflect/types.interface:interface{String() string}$interface" to %runtime.typecodeID*), i32 0, %runtime.interfaceMethodInfo* null, %runtime.typecodeID* @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" }
-@"func String() string" = external constant i8
-@"reflect/types.interface:interface{String() string}$interface" = linkonce_odr constant [1 x i8*] [i8* @"func String() string"]
-@"reflect/types.typeid:basic:int" = external constant i8
-@"error$interface" = linkonce_odr constant [1 x i8*] [i8* @"func Error() string"]
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden %runtime._interface @main.simpleType(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:basic:int" to i32), i8* null }
-}
-
-define hidden %runtime._interface @main.pointerType(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:basic:int" to i32), i8* null }
-}
-
-define hidden %runtime._interface @main.interfaceType(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:named:error" to i32), i8* null }
-}
-
-define hidden %runtime._interface @main.anonymousInterfaceType(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._interface { i32 ptrtoint (%runtime.typecodeID* @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" to i32), i8* null }
-}
-
-define hidden i1 @main.isInt(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %typecode = call i1 @runtime.typeAssert(i32 %itf.typecode, i8* nonnull @"reflect/types.typeid:basic:int", i8* undef, i8* null)
-  br i1 %typecode, label %typeassert.ok, label %typeassert.next
-
-typeassert.ok:                                    ; preds = %entry
-  br label %typeassert.next
-
-typeassert.next:                                  ; preds = %typeassert.ok, %entry
-  ret i1 %typecode
-}
-
-declare i1 @runtime.typeAssert(i32, i8* dereferenceable_or_null(1), i8*, i8*)
-
-define hidden i1 @main.isError(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i1 @runtime.interfaceImplements(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"error$interface", i32 0, i32 0), i8* undef, i8* null)
-  br i1 %0, label %typeassert.ok, label %typeassert.next
-
-typeassert.ok:                                    ; preds = %entry
-  br label %typeassert.next
-
-typeassert.next:                                  ; preds = %typeassert.ok, %entry
-  ret i1 %0
-}
-
-declare i1 @runtime.interfaceImplements(i32, i8** dereferenceable_or_null(4), i8*, i8*)
-
-define hidden i1 @main.isStringer(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i1 @runtime.interfaceImplements(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"reflect/types.interface:interface{String() string}$interface", i32 0, i32 0), i8* undef, i8* null)
-  br i1 %0, label %typeassert.ok, label %typeassert.next
-
-typeassert.ok:                                    ; preds = %entry
-  br label %typeassert.next
-
-typeassert.next:                                  ; preds = %typeassert.ok, %entry
-  ret i1 %0
-}
-
-define hidden %runtime._string @main.callErrorMethod(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %invoke.func = call i32 @runtime.interfaceMethod(i32 %itf.typecode, i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"error$interface", i32 0, i32 0), i8* nonnull @"func Error() string", i8* undef, i8* null)
-  %invoke.func.cast = inttoptr i32 %invoke.func to %runtime._string (i8*, i8*, i8*)*
-  %0 = call %runtime._string %invoke.func.cast(i8* %itf.value, i8* undef, i8* undef)
-  ret %runtime._string %0
-}
-
-declare i32 @runtime.interfaceMethod(i32, i8** dereferenceable_or_null(4), i8* dereferenceable_or_null(1), i8*, i8*)
@@ -1,41 +0,0 @@
-package main
-
-// This file tests various operations on pointers, such as pointer arithmetic
-// and dereferencing pointers.
-
-import "unsafe"
-
-// Dereference pointers.
-
-func pointerDerefZero(x *[0]int) [0]int {
-	return *x // This is a no-op, there is nothing to load.
-}
-
-// Unsafe pointer casts, they are sometimes a no-op.
-
-func pointerCastFromUnsafe(x unsafe.Pointer) *int {
-	return (*int)(x)
-}
-
-func pointerCastToUnsafe(x *int) unsafe.Pointer {
-	return unsafe.Pointer(x)
-}
-
-func pointerCastToUnsafeNoop(x *byte) unsafe.Pointer {
-	return unsafe.Pointer(x)
-}
-
-// The compiler has support for a few special cast+add patterns that are
-// transformed into a single GEP.
-
-func pointerUnsafeGEPFixedOffset(ptr *byte) *byte {
-	return (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + 10))
-}
-
-func pointerUnsafeGEPByteOffset(ptr *byte, offset uintptr) *byte {
-	return (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + offset))
-}
-
-func pointerUnsafeGEPIntOffset(ptr *int32, offset uintptr) *int32 {
-	return (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(ptr)) + offset*4))
-}
@@ -1,51 +0,0 @@
-; ModuleID = 'pointer.go'
-source_filename = "pointer.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden [0 x i32] @main.pointerDerefZero([0 x i32]* %x, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret [0 x i32] zeroinitializer
-}
-
-define hidden i32* @main.pointerCastFromUnsafe(i8* %x, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = bitcast i8* %x to i32*
-  ret i32* %0
-}
-
-define hidden i8* @main.pointerCastToUnsafe(i32* dereferenceable_or_null(4) %x, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = bitcast i32* %x to i8*
-  ret i8* %0
-}
-
-define hidden i8* @main.pointerCastToUnsafeNoop(i8* dereferenceable_or_null(1) %x, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret i8* %x
-}
-
-define hidden i8* @main.pointerUnsafeGEPFixedOffset(i8* dereferenceable_or_null(1) %ptr, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = getelementptr inbounds i8, i8* %ptr, i32 10
-  ret i8* %0
-}
-
-define hidden i8* @main.pointerUnsafeGEPByteOffset(i8* dereferenceable_or_null(1) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = getelementptr inbounds i8, i8* %ptr, i32 %offset
-  ret i8* %0
-}
-
-define hidden i32* @main.pointerUnsafeGEPIntOffset(i32* dereferenceable_or_null(4) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = getelementptr i32, i32* %ptr, i32 %offset
-  ret i32* %0
-}
@@ -1,25 +0,0 @@
-package main
-
-func sliceLen(ints []int) int {
-	return len(ints)
-}
-
-func sliceCap(ints []int) int {
-	return cap(ints)
-}
-
-func sliceElement(ints []int, index int) int {
-	return ints[index]
-}
-
-func sliceAppendValues(ints []int) []int {
-	return append(ints, 1, 2, 3)
-}
-
-func sliceAppendSlice(ints, added []int) []int {
-	return append(ints, added...)
-}
-
-func sliceCopy(dst, src []int) int {
-	return copy(dst, src)
-}
@@ -1,88 +0,0 @@
-; ModuleID = 'slice.go'
-source_filename = "slice.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden i32 @main.sliceLen(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret i32 %ints.len
-}
-
-define hidden i32 @main.sliceCap(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret i32 %ints.cap
-}
-
-define hidden i32 @main.sliceElement(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i32 %index, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %.not = icmp ult i32 %index, %ints.len
-  br i1 %.not, label %lookup.next, label %lookup.throw
-
-lookup.throw:                                     ; preds = %entry
-  call void @runtime.lookupPanic(i8* undef, i8* null)
-  unreachable
-
-lookup.next:                                      ; preds = %entry
-  %0 = getelementptr inbounds i32, i32* %ints.data, i32 %index
-  %1 = load i32, i32* %0, align 4
-  ret i32 %1
-}
-
-declare void @runtime.lookupPanic(i8*, i8*)
-
-define hidden { i32*, i32, i32 } @main.sliceAppendValues(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %varargs = call i8* @runtime.alloc(i32 12, i8* undef, i8* null)
-  %0 = bitcast i8* %varargs to i32*
-  store i32 1, i32* %0, align 4
-  %1 = getelementptr inbounds i8, i8* %varargs, i32 4
-  %2 = bitcast i8* %1 to i32*
-  store i32 2, i32* %2, align 4
-  %3 = getelementptr inbounds i8, i8* %varargs, i32 8
-  %4 = bitcast i8* %3 to i32*
-  store i32 3, i32* %4, align 4
-  %append.srcPtr = bitcast i32* %ints.data to i8*
-  %append.new = call { i8*, i32, i32 } @runtime.sliceAppend(i8* %append.srcPtr, i8* nonnull %varargs, i32 %ints.len, i32 %ints.cap, i32 3, i32 4, i8* undef, i8* null)
-  %append.newPtr = extractvalue { i8*, i32, i32 } %append.new, 0
-  %append.newBuf = bitcast i8* %append.newPtr to i32*
-  %append.newLen = extractvalue { i8*, i32, i32 } %append.new, 1
-  %append.newCap = extractvalue { i8*, i32, i32 } %append.new, 2
-  %5 = insertvalue { i32*, i32, i32 } undef, i32* %append.newBuf, 0
-  %6 = insertvalue { i32*, i32, i32 } %5, i32 %append.newLen, 1
-  %7 = insertvalue { i32*, i32, i32 } %6, i32 %append.newCap, 2
-  ret { i32*, i32, i32 } %7
-}
-
-declare { i8*, i32, i32 } @runtime.sliceAppend(i8*, i8* nocapture readonly, i32, i32, i32, i32, i8*, i8*)
-
-define hidden { i32*, i32, i32 } @main.sliceAppendSlice(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i32* %added.data, i32 %added.len, i32 %added.cap, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %append.srcPtr = bitcast i32* %ints.data to i8*
-  %append.srcPtr1 = bitcast i32* %added.data to i8*
-  %append.new = call { i8*, i32, i32 } @runtime.sliceAppend(i8* %append.srcPtr, i8* %append.srcPtr1, i32 %ints.len, i32 %ints.cap, i32 %added.len, i32 4, i8* undef, i8* null)
-  %append.newPtr = extractvalue { i8*, i32, i32 } %append.new, 0
-  %append.newBuf = bitcast i8* %append.newPtr to i32*
-  %append.newLen = extractvalue { i8*, i32, i32 } %append.new, 1
-  %append.newCap = extractvalue { i8*, i32, i32 } %append.new, 2
-  %0 = insertvalue { i32*, i32, i32 } undef, i32* %append.newBuf, 0
-  %1 = insertvalue { i32*, i32, i32 } %0, i32 %append.newLen, 1
-  %2 = insertvalue { i32*, i32, i32 } %1, i32 %append.newCap, 2
-  ret { i32*, i32, i32 } %2
-}
-
-define hidden i32 @main.sliceCopy(i32* %dst.data, i32 %dst.len, i32 %dst.cap, i32* %src.data, i32 %src.len, i32 %src.cap, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %copy.dstPtr = bitcast i32* %dst.data to i8*
-  %copy.srcPtr = bitcast i32* %src.data to i8*
-  %copy.n = call i32 @runtime.sliceCopy(i8* %copy.dstPtr, i8* %copy.srcPtr, i32 %dst.len, i32 %src.len, i32 4, i8* undef, i8* null)
-  ret i32 %copy.n
-}
-
-declare i32 @runtime.sliceCopy(i8* nocapture writeonly, i8* nocapture readonly, i32, i32, i32, i8*, i8*)
@@ -1,29 +0,0 @@
-package main
-
-func someString() string {
-	return "foo"
-}
-
-func zeroLengthString() string {
-	return ""
-}
-
-func stringLen(s string) int {
-	return len(s)
-}
-
-func stringIndex(s string, index int) byte {
-	return s[index]
-}
-
-func stringCompareEqual(s1, s2 string) bool {
-	return s1 == s2
-}
-
-func stringCompareUnequal(s1, s2 string) bool {
-	return s1 != s2
-}
-
-func stringCompareLarger(s1, s2 string) bool {
-	return s1 > s2
-}
@@ -1,71 +0,0 @@
-; ModuleID = 'string.go'
-source_filename = "string.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
-target triple = "wasm32--wasi"
-
-%runtime._string = type { i8*, i32 }
-
-@"main.someString$string" = internal unnamed_addr constant [3 x i8] c"foo", align 1
-
-declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
-
-define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret void
-}
-
-define hidden %runtime._string @main.someString(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._string { i8* getelementptr inbounds ([3 x i8], [3 x i8]* @"main.someString$string", i32 0, i32 0), i32 3 }
-}
-
-define hidden %runtime._string @main.zeroLengthString(i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret %runtime._string zeroinitializer
-}
-
-define hidden i32 @main.stringLen(i8* %s.data, i32 %s.len, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  ret i32 %s.len
-}
-
-define hidden i8 @main.stringIndex(i8* %s.data, i32 %s.len, i32 %index, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %.not = icmp ult i32 %index, %s.len
-  br i1 %.not, label %lookup.next, label %lookup.throw
-
-lookup.throw:                                     ; preds = %entry
-  call void @runtime.lookupPanic(i8* undef, i8* null)
-  unreachable
-
-lookup.next:                                      ; preds = %entry
-  %0 = getelementptr inbounds i8, i8* %s.data, i32 %index
-  %1 = load i8, i8* %0, align 1
-  ret i8 %1
-}
-
-declare void @runtime.lookupPanic(i8*, i8*)
-
-define hidden i1 @main.stringCompareEqual(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i1 @runtime.stringEqual(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* undef, i8* null)
-  ret i1 %0
-}
-
-declare i1 @runtime.stringEqual(i8*, i32, i8*, i32, i8*, i8*)
-
-define hidden i1 @main.stringCompareUnequal(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i1 @runtime.stringEqual(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* undef, i8* null)
-  %1 = xor i1 %0, true
-  ret i1 %1
-}
-
-define hidden i1 @main.stringCompareLarger(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* %context, i8* %parentHandle) unnamed_addr {
-entry:
-  %0 = call i1 @runtime.stringLess(i8* %s1.data, i32 %s1.len, i8* %s2.data, i32 %s2.len, i8* undef, i8* null)
-  %1 = xor i1 %0, true
-  ret i1 %1
-}
-
-declare i1 @runtime.stringLess(i8*, i32, i8*, i32, i8*, i8*)
@@ -1,16 +1,13 @@
 module github.com/tinygo-org/tinygo

-go 1.13
+go 1.11

 require (
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
-	github.com/chromedp/cdproto v0.0.0-20210113043257-dabd2f2e7693
-	github.com/chromedp/chromedp v0.6.4
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
-	github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892
-	github.com/mattn/go-colorable v0.1.8
-	go.bug.st/serial v1.1.2
-	golang.org/x/sys v0.0.0-20210113181707-4bcb84eeeb78
+	github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46
+	go.bug.st/serial v1.0.0
 	golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2
-	tinygo.org/x/go-llvm v0.0.0-20210325115028-e7b85195e81c
+	google.golang.org/appengine v1.4.0 // indirect
+	tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a
 )
@@ -1,63 +1,59 @@
 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/chromedp/cdproto v0.0.0-20210113043257-dabd2f2e7693 h1:11eq/RkpaotwdF6b1TRMcdgQUPNmyFEJOB7zLvh0O/Y=
-github.com/chromedp/cdproto v0.0.0-20210113043257-dabd2f2e7693/go.mod h1:55pim6Ht4LJKdVLlyFJV/g++HsEA1hQxPbB5JyNdZC0=
-github.com/chromedp/chromedp v0.6.4 h1:Gx7ZkRyrSVmbbDDja/ieNgNGJIvElroPOyeqYQGVDSY=
-github.com/chromedp/chromedp v0.6.4/go.mod h1:vodUdJf5dF/b8n0UBJv6NeM/QK28RjP3j+eM7fq4+84=
-github.com/chromedp/sysutil v1.0.0 h1:+ZxhTpfpZlmchB58ih/LBHX52ky7w2VhQVKQMucy3Ic=
-github.com/chromedp/sysutil v1.0.0/go.mod h1:kgWmDdq8fTzXYcKIBqIYvRRTnYb9aNS9moAV0xufSww=
 github.com/creack/goselect v0.1.1 h1:tiSSgKE1eJtxs1h/VgGQWuXUP0YS4CDIFMp6vaI1ls0=
 github.com/creack/goselect v0.1.1/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
-github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
-github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
-github.com/gobwas/pool v0.2.1/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
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 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
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+tinygo.org/x/go-llvm v0.0.0-20200226165415-53522ab6713d h1:mtgZh/e8a3wxneQFuLXoQYO//1mvlki02yZ1JCwMKp4=
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+tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a h1:Ugje2Lxuv8CFncHzs5W+hWfJvPsM+W4K0zRvzFbLvoE=
+tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
@@ -142,11 +142,10 @@ func getHomeDir() string {
 // getGoroot returns an appropriate GOROOT from various sources. If it can't be
 // found, it returns an empty string.
 func getGoroot() string {
-	// An explicitly set GOROOT always has preference.
 	goroot := os.Getenv("GOROOT")
 	if goroot != "" {
-		// Convert to the standard GOROOT being referenced, if it's a TinyGo cache.
-		return getStandardGoroot(goroot)
+		// An explicitly set GOROOT always has preference.
+		return goroot
 	}

 	// Check for the location of the 'go' binary and base GOROOT on that.
@@ -171,9 +170,8 @@ func getGoroot() string {
 	switch runtime.GOOS {
 	case "linux":
 		candidates = []string{
-			"/usr/local/go",     // manually installed
-			"/usr/lib/go",       // from the distribution
-			"/snap/go/current/", // installed using snap
+			"/usr/local/go", // manually installed
+			"/usr/lib/go",   // from the distribution
 		}
 	case "darwin":
 		candidates = []string{
@@ -197,21 +195,3 @@ func isGoroot(goroot string) bool {
 	_, err := os.Stat(filepath.Join(goroot, "src", "runtime", "internal", "sys", "zversion.go"))
 	return err == nil
 }
-
-// getStandardGoroot returns the physical path to a real, standard Go GOROOT
-// implied by the given path.
-// If the given path appears to be a TinyGo cached GOROOT, it returns the path
-// referenced by symlinks contained in the cache. Otherwise, it returns the
-// given path as-is.
-func getStandardGoroot(path string) string {
-	// Check if the "bin" subdirectory of our given GOROOT is a symlink, and then
-	// return the _parent_ directory of its destination.
-	if dest, err := os.Readlink(filepath.Join(path, "bin")); nil == err {
-		// Clean the destination to remove any trailing slashes, so that
-		// filepath.Dir will always return the parent.
-		//   (because both "/foo" and "/foo/" are valid symlink destinations,
-		//   but filepath.Dir would return "/" and "/foo", respectively)
-		return filepath.Dir(filepath.Clean(dest))
-	}
-	return path
-}
@@ -10,10 +10,6 @@ import (
 	"strings"
 )

-// Version of TinyGo.
-// Update this value before release of new version of software.
-const Version = "0.18.0"
-
 // 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) {
@@ -1,5 +0,0 @@
-# Hooks for Docker Hub
-
-Files in this directory are custom commands to be run during the different Docker Hub build phases.
-
-See https://docs.docker.com/docker-hub/builds/advanced/#custom-build-phase-hooks
@@ -1,4 +0,0 @@
-#!/bin/bash
-# Docker hub does a recursive clone, then checks the branch out,
-# so when a PR adds a submodule (or updates it), it fails.
-git submodule update --init
@@ -6,81 +6,50 @@ possible and only run unknown expressions (e.g. external calls) at runtime. This
 is in practice a partial evaluator of the `runtime.initAll` function, which
 calls each package initializer.

-This package is a rewrite of a previous partial evaluator that worked
-directly on LLVM IR and used the module and LLVM constants as intermediate
-values. This newer version instead uses a mostly Go intermediate form. It
-compiles functions and extracts relevant data first (compiler.go), then
-executes those functions (interpreter.go) in a memory space that can be
-rolled back per function (memory.go). This means that it is not necessary to
-scan functions to see whether they can be run at compile time, which was very
-error prone. Instead it just tries to execute everything and if it hits
-something it cannot interpret (such as a store to memory-mapped I/O) it rolls
-back the execution of that function and runs the function at runtime instead.
-All in all, this design provides several benefits:
+It works by directly interpreting LLVM IR:

-  * Much better error handling. By being able to revert to runtime execution
-    without the need for scanning functions, this version is able to
-    automatically work around many bugs in the previous implementation.
-  * More correct memory model. This is not inherent to the new design, but the
-    new design also made the memory model easier to reason about.
-  * Faster execution of initialization code. While it is not much faster for
-    normal interpretation (maybe 25% or so) due to the compilation overhead,
-    it should be a whole lot faster for loops as it doesn't have to call into
-    LLVM (via CGo) for every operation.
-
-As mentioned, this partial evaulator comes in three parts: a compiler, an
-interpreter, and a memory manager.
-
-## Compiler
-
-The main task of the compiler is that it extracts all necessary data from
-every instruction in a function so that when this instruction is interpreted,
-no additional CGo calls are necessary. This is not currently done for all
-instructions (`runtime.alloc` is a notable exception), but at least it does
-so for the vast majority of instructions.
-
-## Interpreter
-
-The interpreter runs an instruction just like it would if it were executed
-'for real'. The vast majority of instructions can be executed at compile
-time. As indicated above, some instructions need to be executed at runtime
-instead.
-
-## Memory
-
-Memory is represented as objects (the `object` type) that contains data that
-will eventually be stored in a global and values (the `value` interface) that
-can be worked with while running the interpreter. Values therefore are only
-used locally and are always passed by value (just like most LLVM constants)
-while objects represent the backing storage (like LLVM globals). Some values
-are pointer values, and point to an object.
-
-Importantly, this partial evaluator can roll back the execution of a
-function. This is implemented by creating a new memory view per function
-activation, which makes sure that any change to a global (such as a store
-instruction) is stored in the memory view. It creates a copy of the object
-and stores that in the memory view to be modified. Once the function has
-executed successfully, all these modified objects are then copied into the
-parent function, up to the root function invocation which (on successful
-execution) writes the values back into the LLVM module. This way, function
-invocations can be rolled back without leaving a trace.
-
-Pointer values point to memory objects, but not to a particular memory
-object. Every memory object is given an index, and pointers use that index to
-look up the current active object for the pointer to load from or to copy
-when storing to it.
-
-Rolling back a function should roll back everyting, including the few
-instructions emitted at runtime. This is done by treating instructions much
-like memory objects and removing the created instructions when necessary.
+  * Almost all operations work directly on constants, and are implemented using
+    the llvm.Const* set of functions that are evaluated directly.
+  * External function calls and some other operations (inline assembly, volatile
+    load, volatile store) are seen as having limited side effects. Limited in
+    the sense that it is known at compile time which globals it affects, which
+    then are marked 'dirty' (meaning, further operations on it must be done at
+    runtime). These operations are emitted directly in the `runtime.initAll`
+    function. Return values are also considered 'dirty'.
+  * Such 'dirty' objects and local values must be executed at runtime instead of
+    at compile time. This dirtyness propagates further through the IR, for
+    example storing a dirty local value to a global also makes the global dirty,
+    meaning that the global may not be read or written at compile time as it's
+    contents at that point during interpretation is unknown.
+  * There are some heuristics in place to avoid doing too much with dirty
+    values. For example, a branch based on a dirty local marks the whole
+    function itself as having side effect (as if it is an external function).
+    However, all globals it touches are still taken into account and when a call
+    is inserted in `runtime.initAll`, all globals it references are also marked
+    dirty.
+  * Heap allocation (`runtime.alloc`) is emulated by creating new objects. The
+    value in the allocation is the initializer of the global, the zero value is
+    the zero initializer.
+  * Stack allocation (`alloca`) is often emulated using a fake alloca object,
+    until the address of the alloca is taken in which case it is also created as
+    a real `alloca` in `runtime.initAll` and marked dirty. This may be necessary
+    when calling an external function with the given alloca as paramter.

 ## Why is this necessary?

 A partial evaluator is hard to get right, so why go through all the trouble of
 writing one?

-The answer is that globals with initializers are much easier to optimize by
-LLVM than initialization code. Also, there are a few other benefits:
+The main reason is that the previous attempt wasn't complete and wasn't sound.
+It simply tried to evaluate Go SSA directly, which was good but more difficult
+than necessary. An IR based interpreter needs to understand fewer instructions
+as the LLVM IR simply has less (complex) instructions than Go SSA. Also, LLVM
+provides some useful tools like easily getting all uses of a function or global,
+which Go SSA does not provide.
+
+But why is it necessary at all? The answer is that globals with initializers are
+much easier to optimize by LLVM than initialization code. Also, there are a few
+other benefits:

  * Dead globals are trivial to optimize away.
  * Constant globals are easier to detect. Remember that Go does not have global
@@ -91,29 +60,5 @@ LLVM than initialization code. Also, there are a few other benefits:
  * Constants are much more efficent on microcontrollers, as they can be
    allocated in flash instead of RAM.

-The Go SSA package does not create constant initializers for globals.
-Instead, it emits initialization functions, so if you write the following:
-
-```go
-var foo = []byte{1, 2, 3, 4}
-```
-
-It would generate something like this:
-
-```go
-var foo []byte
-
-func init() {
-    foo = make([]byte, 4)
-    foo[0] = 1
-    foo[1] = 2
-    foo[2] = 3
-    foo[3] = 4
-}
-```
-
-This is of course hugely wasteful, it's much better to create `foo` as a
-global array instead of initializing it at runtime.
-
 For more details, see [this section of the
 documentation](https://tinygo.org/compiler-internals/differences-from-go/).
@@ -1,426 +0,0 @@
-package interp
-
-// This file compiles the LLVM IR to a form that's easy to efficiently
-// interpret.
-
-import (
-	"strings"
-
-	"tinygo.org/x/go-llvm"
-)
-
-// A function is a compiled LLVM function, which means that interpreting it
-// avoids most CGo calls necessary. This is done in a separate step so the
-// result can be cached.
-// Functions are in SSA form, just like the LLVM version if it. The first block
-// (blocks[0]) is the entry block.
-type function struct {
-	llvmFn llvm.Value
-	name   string       // precalculated llvmFn.Name()
-	params []llvm.Value // precalculated llvmFn.Params()
-	blocks []*basicBlock
-	locals map[llvm.Value]int
-}
-
-// basicBlock represents a LLVM basic block and contains a slice of
-// instructions. The last instruction must be a terminator instruction.
-type basicBlock struct {
-	phiNodes     []instruction
-	instructions []instruction
-}
-
-// instruction is a precompiled LLVM IR instruction. The operands can be either
-// an already known value (such as literalValue or pointerValue) but can also be
-// the special localValue, which means that the value is a function parameter or
-// is produced by another instruction in the function. In that case, the
-// interpreter will replace the operand with that local value.
-type instruction struct {
-	opcode     llvm.Opcode
-	localIndex int
-	operands   []value
-	llvmInst   llvm.Value
-	name       string
-}
-
-// String returns a nice human-readable version of this instruction.
-func (inst *instruction) String() string {
-	operands := make([]string, len(inst.operands))
-	for i, op := range inst.operands {
-		operands[i] = op.String()
-	}
-
-	name := instructionNameMap[inst.opcode]
-	if name == "" {
-		name = "<unknown op>"
-	}
-	return name + " " + strings.Join(operands, " ")
-}
-
-// compileFunction compiles a given LLVM function to an easier to interpret
-// version of the function. As far as possible, all operands are preprocessed so
-// that the interpreter doesn't have to call into LLVM.
-func (r *runner) compileFunction(llvmFn llvm.Value) *function {
-	fn := &function{
-		llvmFn: llvmFn,
-		name:   llvmFn.Name(),
-		params: llvmFn.Params(),
-		locals: make(map[llvm.Value]int),
-	}
-	if llvmFn.IsDeclaration() {
-		// Nothing to do.
-		return fn
-	}
-
-	for i, param := range fn.params {
-		fn.locals[param] = i
-	}
-
-	// Make a map of all the blocks, to quickly find the block number for a
-	// given branch instruction.
-	blockIndices := make(map[llvm.Value]int)
-	for llvmBB := llvmFn.FirstBasicBlock(); !llvmBB.IsNil(); llvmBB = llvm.NextBasicBlock(llvmBB) {
-		index := len(blockIndices)
-		blockIndices[llvmBB.AsValue()] = index
-	}
-
-	// Compile every block.
-	for llvmBB := llvmFn.FirstBasicBlock(); !llvmBB.IsNil(); llvmBB = llvm.NextBasicBlock(llvmBB) {
-		bb := &basicBlock{}
-		fn.blocks = append(fn.blocks, bb)
-
-		// Compile every instruction in the block.
-		for llvmInst := llvmBB.FirstInstruction(); !llvmInst.IsNil(); llvmInst = llvm.NextInstruction(llvmInst) {
-			// Create instruction skeleton.
-			opcode := llvmInst.InstructionOpcode()
-			inst := instruction{
-				opcode:     opcode,
-				localIndex: len(fn.locals),
-				llvmInst:   llvmInst,
-			}
-			fn.locals[llvmInst] = len(fn.locals)
-
-			// Add operands specific for this instruction.
-			switch opcode {
-			case llvm.Ret:
-				// Return instruction, which can either be a `ret void` (no
-				// return value) or return a value.
-				numOperands := llvmInst.OperandsCount()
-				if numOperands != 0 {
-					inst.operands = []value{
-						r.getValue(llvmInst.Operand(0)),
-					}
-				}
-			case llvm.Br:
-				// Branch instruction. Can be either a conditional branch (with
-				// 3 operands) or unconditional branch (with just one basic
-				// block operand).
-				numOperands := llvmInst.OperandsCount()
-				switch numOperands {
-				case 3:
-					// Conditional jump to one of two blocks. Comparable to an
-					// if/else in procedural languages.
-					thenBB := llvmInst.Operand(2)
-					elseBB := llvmInst.Operand(1)
-					inst.operands = []value{
-						r.getValue(llvmInst.Operand(0)),
-						literalValue{uint32(blockIndices[thenBB])},
-						literalValue{uint32(blockIndices[elseBB])},
-					}
-				case 1:
-					// Unconditional jump to a target basic block. Comparable to
-					// a jump in C and Go.
-					jumpBB := llvmInst.Operand(0)
-					inst.operands = []value{
-						literalValue{uint32(blockIndices[jumpBB])},
-					}
-				default:
-					panic("unknown number of operands")
-				}
-			case llvm.Switch:
-				// A switch is an array of (value, label) pairs, of which the
-				// first one indicates the to-switch value and the default
-				// label.
-				numOperands := llvmInst.OperandsCount()
-				for i := 0; i < numOperands; i += 2 {
-					inst.operands = append(inst.operands, r.getValue(llvmInst.Operand(i)))
-					inst.operands = append(inst.operands, literalValue{uint32(blockIndices[llvmInst.Operand(i+1)])})
-				}
-			case llvm.PHI:
-				inst.name = llvmInst.Name()
-				incomingCount := inst.llvmInst.IncomingCount()
-				for i := 0; i < incomingCount; i++ {
-					incomingBB := inst.llvmInst.IncomingBlock(i)
-					incomingValue := inst.llvmInst.IncomingValue(i)
-					inst.operands = append(inst.operands,
-						literalValue{uint32(blockIndices[incomingBB.AsValue()])},
-						r.getValue(incomingValue),
-					)
-				}
-			case llvm.Select:
-				// Select is a special instruction that is much like a ternary
-				// operator. It produces operand 1 or 2 based on the boolean
-				// that is operand 0.
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					r.getValue(llvmInst.Operand(1)),
-					r.getValue(llvmInst.Operand(2)),
-				}
-			case llvm.Call:
-				// Call is a regular function call but could also be a runtime
-				// intrinsic. Some runtime intrinsics are treated specially by
-				// the interpreter, such as runtime.alloc. We don't
-				// differentiate between them here because these calls may also
-				// need to be run at runtime, in which case they should all be
-				// created in the same way.
-				llvmCalledValue := llvmInst.CalledValue()
-				if !llvmCalledValue.IsAFunction().IsNil() {
-					name := llvmCalledValue.Name()
-					if name == "llvm.dbg.value" || strings.HasPrefix(name, "llvm.lifetime.") {
-						// These intrinsics should not be interpreted, they are not
-						// relevant to the execution of this function.
-						continue
-					}
-				}
-				inst.name = llvmInst.Name()
-				numOperands := llvmInst.OperandsCount()
-				inst.operands = append(inst.operands, r.getValue(llvmCalledValue))
-				for i := 0; i < numOperands-1; i++ {
-					inst.operands = append(inst.operands, r.getValue(llvmInst.Operand(i)))
-				}
-			case llvm.Load:
-				// Load instruction. The interpreter will load from the
-				// appropriate memory view.
-				// Also provide the memory size to be loaded, which is necessary
-				// with a lack of type information.
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					literalValue{r.targetData.TypeAllocSize(llvmInst.Type())},
-				}
-			case llvm.Store:
-				// Store instruction. The interpreter will create a new object
-				// in the memory view of the function invocation and store to
-				// that, to make it possible to roll back this store.
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					r.getValue(llvmInst.Operand(1)),
-				}
-			case llvm.Alloca:
-				// Alloca allocates stack space for local variables.
-				numElements := r.getValue(inst.llvmInst.Operand(0)).(literalValue).value.(uint32)
-				elementSize := r.targetData.TypeAllocSize(inst.llvmInst.Type().ElementType())
-				inst.operands = []value{
-					literalValue{elementSize * uint64(numElements)},
-				}
-			case llvm.GetElementPtr:
-				// GetElementPtr does pointer arithmetic.
-				inst.name = llvmInst.Name()
-				ptr := llvmInst.Operand(0)
-				n := llvmInst.OperandsCount()
-				elementType := ptr.Type().ElementType()
-				// gep: [source ptr, dest value size, pairs of indices...]
-				inst.operands = []value{
-					r.getValue(ptr),
-					literalValue{r.targetData.TypeAllocSize(llvmInst.Type().ElementType())},
-					r.getValue(llvmInst.Operand(1)),
-					literalValue{r.targetData.TypeAllocSize(elementType)},
-				}
-				for i := 2; i < n; i++ {
-					operand := r.getValue(llvmInst.Operand(i))
-					if elementType.TypeKind() == llvm.StructTypeKind {
-						index := operand.(literalValue).value.(uint32)
-						elementOffset := r.targetData.ElementOffset(elementType, int(index))
-						// Encode operands in a special way. The elementOffset
-						// is just the offset in bytes. The elementSize is a
-						// negative number (when cast to a int64) by flipping
-						// all the bits. This allows the interpreter to detect
-						// this is a struct field and that it should not
-						// multiply it with the elementOffset to get the offset.
-						// It is important for the interpreter to know the
-						// struct field index for when the GEP must be done at
-						// runtime.
-						inst.operands = append(inst.operands, literalValue{elementOffset}, literalValue{^uint64(index)})
-						elementType = elementType.StructElementTypes()[index]
-					} else {
-						elementType = elementType.ElementType()
-						elementSize := r.targetData.TypeAllocSize(elementType)
-						elementSizeOperand := literalValue{elementSize}
-						// Add operand * elementSizeOperand bytes to the pointer.
-						inst.operands = append(inst.operands, operand, elementSizeOperand)
-					}
-				}
-			case llvm.BitCast, llvm.IntToPtr, llvm.PtrToInt:
-				// Bitcasts are ususally used to cast a pointer from one type to
-				// another leaving the pointer itself intact.
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-				}
-			case llvm.ExtractValue:
-				inst.name = llvmInst.Name()
-				agg := llvmInst.Operand(0)
-				var offset uint64
-				indexingType := agg.Type()
-				for _, index := range inst.llvmInst.Indices() {
-					switch indexingType.TypeKind() {
-					case llvm.StructTypeKind:
-						offset += r.targetData.ElementOffset(indexingType, int(index))
-						indexingType = indexingType.StructElementTypes()[index]
-					default: // ArrayTypeKind
-						indexingType = indexingType.ElementType()
-						elementSize := r.targetData.TypeAllocSize(indexingType)
-						offset += elementSize * uint64(index)
-					}
-				}
-				size := r.targetData.TypeAllocSize(inst.llvmInst.Type())
-				// extractvalue [agg, byteOffset, byteSize]
-				inst.operands = []value{
-					r.getValue(agg),
-					literalValue{offset},
-					literalValue{size},
-				}
-			case llvm.InsertValue:
-				inst.name = llvmInst.Name()
-				agg := llvmInst.Operand(0)
-				var offset uint64
-				indexingType := agg.Type()
-				for _, index := range inst.llvmInst.Indices() {
-					switch indexingType.TypeKind() {
-					case llvm.StructTypeKind:
-						offset += r.targetData.ElementOffset(indexingType, int(index))
-						indexingType = indexingType.StructElementTypes()[index]
-					default: // ArrayTypeKind
-						indexingType = indexingType.ElementType()
-						elementSize := r.targetData.TypeAllocSize(indexingType)
-						offset += elementSize * uint64(index)
-					}
-				}
-				// insertvalue [agg, elt, byteOffset]
-				inst.operands = []value{
-					r.getValue(agg),
-					r.getValue(llvmInst.Operand(1)),
-					literalValue{offset},
-				}
-			case llvm.ICmp:
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					r.getValue(llvmInst.Operand(1)),
-					literalValue{uint8(llvmInst.IntPredicate())},
-				}
-			case llvm.FCmp:
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					r.getValue(llvmInst.Operand(1)),
-					literalValue{uint8(llvmInst.FloatPredicate())},
-				}
-			case llvm.Add, llvm.Sub, llvm.Mul, llvm.UDiv, llvm.SDiv, llvm.URem, llvm.SRem, llvm.Shl, llvm.LShr, llvm.AShr, llvm.And, llvm.Or, llvm.Xor:
-				// Integer binary operations.
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					r.getValue(llvmInst.Operand(1)),
-				}
-			case llvm.SExt, llvm.ZExt, llvm.Trunc:
-				// Extend or shrink an integer size.
-				// No sign extension going on so easy to do.
-				// zext: [value, bitwidth]
-				// trunc: [value, bitwidth]
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					literalValue{uint64(llvmInst.Type().IntTypeWidth())},
-				}
-			case llvm.SIToFP, llvm.UIToFP:
-				// Convert an integer to a floating point instruction.
-				// opcode: [value, bitwidth]
-				inst.name = llvmInst.Name()
-				inst.operands = []value{
-					r.getValue(llvmInst.Operand(0)),
-					literalValue{uint64(r.targetData.TypeAllocSize(llvmInst.Type()) * 8)},
-				}
-			default:
-				// Unknown instruction, which is already set in inst.opcode so
-				// is detectable.
-				// This error is handled when actually trying to interpret this
-				// instruction (to not trigger on code that won't be executed).
-			}
-			if inst.opcode == llvm.PHI {
-				// PHI nodes need to be treated specially, see the comment in
-				// interpreter.go for an explanation.
-				bb.phiNodes = append(bb.phiNodes, inst)
-			} else {
-				bb.instructions = append(bb.instructions, inst)
-			}
-		}
-	}
-	return fn
-}
-
-// instructionNameMap maps from instruction opcodes to instruction names. This
-// can be useful for debug logging.
-var instructionNameMap = [...]string{
-	llvm.Ret:         "ret",
-	llvm.Br:          "br",
-	llvm.Switch:      "switch",
-	llvm.IndirectBr:  "indirectbr",
-	llvm.Invoke:      "invoke",
-	llvm.Unreachable: "unreachable",
-
-	// Standard Binary Operators
-	llvm.Add:  "add",
-	llvm.FAdd: "fadd",
-	llvm.Sub:  "sub",
-	llvm.FSub: "fsub",
-	llvm.Mul:  "mul",
-	llvm.FMul: "fmul",
-	llvm.UDiv: "udiv",
-	llvm.SDiv: "sdiv",
-	llvm.FDiv: "fdiv",
-	llvm.URem: "urem",
-	llvm.SRem: "srem",
-	llvm.FRem: "frem",
-
-	// Logical Operators
-	llvm.Shl:  "shl",
-	llvm.LShr: "lshr",
-	llvm.AShr: "ashr",
-	llvm.And:  "and",
-	llvm.Or:   "or",
-	llvm.Xor:  "xor",
-
-	// Memory Operators
-	llvm.Alloca:        "alloca",
-	llvm.Load:          "load",
-	llvm.Store:         "store",
-	llvm.GetElementPtr: "getelementptr",
-
-	// Cast Operators
-	llvm.Trunc:    "trunc",
-	llvm.ZExt:     "zext",
-	llvm.SExt:     "sext",
-	llvm.FPToUI:   "fptoui",
-	llvm.FPToSI:   "fptosi",
-	llvm.UIToFP:   "uitofp",
-	llvm.SIToFP:   "sitofp",
-	llvm.FPTrunc:  "fptrunc",
-	llvm.FPExt:    "fpext",
-	llvm.PtrToInt: "ptrtoint",
-	llvm.IntToPtr: "inttoptr",
-	llvm.BitCast:  "bitcast",
-
-	// Other Operators
-	llvm.ICmp:           "icmp",
-	llvm.FCmp:           "fcmp",
-	llvm.PHI:            "phi",
-	llvm.Call:           "call",
-	llvm.Select:         "select",
-	llvm.VAArg:          "vaarg",
-	llvm.ExtractElement: "extractelement",
-	llvm.InsertElement:  "insertelement",
-	llvm.ShuffleVector:  "shufflevector",
-	llvm.ExtractValue:   "extractvalue",
-	llvm.InsertValue:    "insertvalue",
-}
@@ -11,22 +11,15 @@ import (
 	"tinygo.org/x/go-llvm"
 )

-// These errors are expected during normal execution and can be recovered from
-// by running the affected function at runtime instead of compile time.
-var (
-	errIntegerAsPointer       = errors.New("interp: trying to use an integer as a pointer (memory-mapped I/O?)")
-	errUnsupportedInst        = errors.New("interp: unsupported instruction")
-	errUnsupportedRuntimeInst = errors.New("interp: unsupported instruction (to be emitted at runtime)")
-	errMapAlreadyCreated      = errors.New("interp: map already created")
-)
+// errUnreachable is returned when an unreachable instruction is executed. This
+// error should not be visible outside of the interp package.
+var errUnreachable = &Error{Err: errors.New("interp: unreachable executed")}

-// This is one of the errors that can be returned from toLLVMValue when the
-// passed type does not fit the data to serialize. It is recoverable by
-// serializing without a type (using rawValue.rawLLVMValue).
-var errInvalidPtrToIntSize = errors.New("interp: ptrtoint integer size does not equal pointer size")
-
-func isRecoverableError(err error) bool {
-	return err == errIntegerAsPointer || err == errUnsupportedInst || err == errUnsupportedRuntimeInst || err == errMapAlreadyCreated
+// 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) *Error {
+	return e.errorAt(inst, errors.New("interp: unsupported instruction"))
 }

 // ErrorLine is one line in a traceback. The position may be missing.
@@ -53,13 +46,11 @@ func (e *Error) Error() string {
 // 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 (r *runner) errorAt(inst instruction, err error) *Error {
-	pos := getPosition(inst.llvmInst)
+func (e *evalPackage) errorAt(inst llvm.Value, err error) *Error {
 	return &Error{
-		ImportPath: r.pkgName,
-		Pos:        pos,
+		ImportPath: e.packagePath,
+		Pos:        getPosition(inst),
 		Err:        err,
-		Traceback:  []ErrorLine{{pos, inst.llvmInst}},
 	}
 }

@@ -0,0 +1,680 @@
+package interp
+
+// This file implements the core interpretation routines, interpreting single
+// functions.
+
+import (
+	"errors"
+	"strings"
+
+	"tinygo.org/x/go-llvm"
+)
+
+type frame struct {
+	*evalPackage
+	fn     llvm.Value
+	locals map[llvm.Value]Value
+}
+
+// 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.
+// Most of it works at compile time. Some calls get translated into calls to be
+// executed at runtime: calls to functions with side effects, external calls,
+// and operations on the result of such instructions.
+func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (retval Value, outgoing []llvm.Value, err *Error) {
+	for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+		if fr.Debug {
+			print(indent)
+			inst.Dump()
+			println()
+		}
+		switch {
+		case !inst.IsABinaryOperator().IsNil():
+			lhs := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
+			rhs := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
+
+			switch inst.InstructionOpcode() {
+			// Standard binary operators
+			case llvm.Add:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateAdd(lhs, rhs, "")}
+			case llvm.FAdd:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFAdd(lhs, rhs, "")}
+			case llvm.Sub:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSub(lhs, rhs, "")}
+			case llvm.FSub:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFSub(lhs, rhs, "")}
+			case llvm.Mul:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateMul(lhs, rhs, "")}
+			case llvm.FMul:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFMul(lhs, rhs, "")}
+			case llvm.UDiv:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateUDiv(lhs, rhs, "")}
+			case llvm.SDiv:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSDiv(lhs, rhs, "")}
+			case llvm.FDiv:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFDiv(lhs, rhs, "")}
+			case llvm.URem:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateURem(lhs, rhs, "")}
+			case llvm.SRem:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSRem(lhs, rhs, "")}
+			case llvm.FRem:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFRem(lhs, rhs, "")}
+
+			// Logical operators
+			case llvm.Shl:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateShl(lhs, rhs, "")}
+			case llvm.LShr:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateLShr(lhs, rhs, "")}
+			case llvm.AShr:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateAShr(lhs, rhs, "")}
+			case llvm.And:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateAnd(lhs, rhs, "")}
+			case llvm.Or:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateOr(lhs, rhs, "")}
+			case llvm.Xor:
+				fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateXor(lhs, rhs, "")}
+
+			default:
+				return nil, nil, fr.unsupportedInstructionError(inst)
+			}
+
+		// Memory operators
+		case !inst.IsAAllocaInst().IsNil():
+			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)).(*LocalValue)
+			var value llvm.Value
+			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() {
+				return nil, nil, fr.errorAt(inst, errors.New("interp: load: type does not match"))
+			}
+			fr.locals[inst] = fr.getValue(value)
+		case !inst.IsAStoreInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			ptr := fr.getLocal(inst.Operand(1))
+			if inst.IsVolatile() {
+				fr.builder.CreateStore(value.Value(), ptr.Value())
+			} else {
+				ptr.Store(value.Value())
+			}
+		case !inst.IsAGetElementPtrInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			llvmIndices := make([]llvm.Value, inst.OperandsCount()-1)
+			for i := range llvmIndices {
+				llvmIndices[i] = inst.Operand(i + 1)
+			}
+			indices := make([]uint32, len(llvmIndices))
+			for i, llvmIndex := range llvmIndices {
+				operand := fr.getLocal(llvmIndex)
+				if !operand.IsConstant() {
+					// Not a constant operation.
+					// This should be detected by the scanner, but isn't at the
+					// moment.
+					return nil, nil, fr.errorAt(inst, errors.New("todo: non-const gep"))
+				}
+				indices[i] = uint32(operand.Value().ZExtValue())
+			}
+			result, err := value.GetElementPtr(indices)
+			if err != nil {
+				return nil, nil, fr.errorAt(inst, err)
+			}
+			if result.Type() != inst.Type() {
+				return nil, nil, fr.errorAt(inst, errors.New("interp: gep: type does not match"))
+			}
+			fr.locals[inst] = result
+
+		// Cast operators
+		case !inst.IsATruncInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateTrunc(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAZExtInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateZExt(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsASExtInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSExt(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAFPToUIInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFPToUI(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAFPToSIInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFPToSI(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAUIToFPInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateUIToFP(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsASIToFPInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSIToFP(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAFPTruncInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFPTrunc(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAFPExtInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFPExt(value.(*LocalValue).Value(), inst.Type(), "")}
+		case !inst.IsAPtrToIntInst().IsNil():
+			value := fr.getLocal(inst.Operand(0))
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreatePtrToInt(value.Value(), inst.Type(), "")}
+		case !inst.IsABitCastInst().IsNil() && inst.Type().TypeKind() == llvm.PointerTypeKind:
+			operand := inst.Operand(0)
+			if !operand.IsACallInst().IsNil() {
+				fn := operand.CalledValue()
+				if !fn.IsAFunction().IsNil() && fn.Name() == "runtime.alloc" {
+					continue // special case: bitcast of alloc
+				}
+			}
+			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, errors.New("unimplemented: bitcast of map"))
+			}
+			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
+			rhs := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
+			predicate := inst.FloatPredicate()
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateFCmp(predicate, lhs, rhs, "")}
+		case !inst.IsAPHINode().IsNil():
+			for i := 0; i < inst.IncomingCount(); i++ {
+				if inst.IncomingBlock(i) == incoming {
+					fr.locals[inst] = fr.getLocal(inst.IncomingValue(i))
+				}
+			}
+		case !inst.IsACallInst().IsNil():
+			callee := inst.CalledValue()
+			switch {
+			case callee.Name() == "runtime.alloc":
+				// heap allocation
+				users := getUses(inst)
+				var resultInst = inst
+				if len(users) == 1 && !users[0].IsABitCastInst().IsNil() {
+					// happens when allocating something other than i8*
+					resultInst = users[0]
+				}
+				size := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying.ZExtValue()
+				allocType := resultInst.Type().ElementType()
+				typeSize := fr.TargetData.TypeAllocSize(allocType)
+				elementCount := 1
+				if size != typeSize {
+					// allocate an array
+					if size%typeSize != 0 {
+						return nil, nil, fr.unsupportedInstructionError(inst)
+					}
+					elementCount = int(size / typeSize)
+					allocType = llvm.ArrayType(allocType, elementCount)
+				}
+				alloc := llvm.AddGlobal(fr.Mod, allocType, fr.packagePath+"$alloc")
+				alloc.SetInitializer(llvm.ConstNull(allocType))
+				alloc.SetLinkage(llvm.InternalLinkage)
+				result := &LocalValue{
+					Underlying: alloc,
+					Eval:       fr.Eval,
+				}
+				if elementCount == 1 {
+					fr.locals[resultInst] = result
+				} else {
+					result, err := result.GetElementPtr([]uint32{0, 0})
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
+					fr.locals[resultInst] = result
+				}
+			case callee.Name() == "runtime.hashmapMake":
+				// create a map
+				keySize := inst.Operand(0).ZExtValue()
+				valueSize := inst.Operand(1).ZExtValue()
+				fr.locals[inst] = &MapValue{
+					Eval:      fr.Eval,
+					PkgName:   fr.packagePath,
+					KeySize:   int(keySize),
+					ValueSize: int(valueSize),
+				}
+			case callee.Name() == "runtime.hashmapStringSet":
+				// set a string key in the map
+				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.
+				m.PutString(keyBuf, keyLen, valPtr)
+			case callee.Name() == "runtime.hashmapBinarySet":
+				// set a binary (int etc.) key in the map
+				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
+				buf1Ptr := fr.getLocal(inst.Operand(0))
+				buf1Len := fr.getLocal(inst.Operand(1))
+				buf2Ptr := fr.getLocal(inst.Operand(2))
+				buf2Len := fr.getLocal(inst.Operand(3))
+				buf1 := getStringBytes(buf1Ptr, buf1Len.Value())
+				buf2 := getStringBytes(buf2Ptr, buf2Len.Value())
+				result := []byte(string(buf1) + string(buf2))
+				vals := make([]llvm.Value, len(result))
+				for i := range vals {
+					vals[i] = llvm.ConstInt(fr.Mod.Context().Int8Type(), uint64(result[i]), false)
+				}
+				globalType := llvm.ArrayType(fr.Mod.Context().Int8Type(), len(result))
+				globalValue := llvm.ConstArray(fr.Mod.Context().Int8Type(), vals)
+				global := llvm.AddGlobal(fr.Mod, globalType, fr.packagePath+"$stringconcat")
+				global.SetInitializer(globalValue)
+				global.SetLinkage(llvm.InternalLinkage)
+				global.SetGlobalConstant(true)
+				global.SetUnnamedAddr(true)
+				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 := 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, fr.errorAt(inst, err)
+					}
+					dstArray = dstArrayValue.(*LocalValue)
+					srcArrayValue, err := srcArray.GetElementPtr([]uint32{0, 0})
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
+					srcArray = srcArrayValue.(*LocalValue)
+				}
+				if fr.Eval.TargetData.TypeAllocSize(dstArray.Type().ElementType()) != elementSize {
+					return nil, nil, fr.errorAt(inst, errors.New("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, errors.New("interp: slice src element size does not match pointer type"))
+				}
+				if dstArray.Type() != srcArray.Type() {
+					return nil, nil, fr.errorAt(inst, errors.New("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, errors.New("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, fr.errorAt(inst, err)
+					}
+					dstArray = dstArrayValue.(*LocalValue)
+					// src++
+					srcArrayValue, err := srcArray.GetElementPtr([]uint32{1})
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
+					srcArray = srcArrayValue.(*LocalValue)
+				}
+			case callee.Name() == "runtime.stringToBytes":
+				// convert a string to a []byte
+				bufPtr := fr.getLocal(inst.Operand(0))
+				bufLen := fr.getLocal(inst.Operand(1))
+				result := getStringBytes(bufPtr, bufLen.Value())
+				vals := make([]llvm.Value, len(result))
+				for i := range vals {
+					vals[i] = llvm.ConstInt(fr.Mod.Context().Int8Type(), uint64(result[i]), false)
+				}
+				globalType := llvm.ArrayType(fr.Mod.Context().Int8Type(), len(result))
+				globalValue := llvm.ConstArray(fr.Mod.Context().Int8Type(), vals)
+				global := llvm.AddGlobal(fr.Mod, globalType, fr.packagePath+"$bytes")
+				global.SetInitializer(globalValue)
+				global.SetLinkage(llvm.InternalLinkage)
+				global.SetGlobalConstant(true)
+				global.SetUnnamedAddr(true)
+				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 := 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.typeAssert":
+				actualTypeInt := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
+				assertedType := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
+				if actualTypeInt.IsAConstantExpr().IsNil() || actualTypeInt.Opcode() != llvm.PtrToInt {
+					return nil, nil, fr.errorAt(inst, errors.New("interp: expected typecode in runtime.typeAssert to be a ptrtoint"))
+				}
+				actualType := actualTypeInt.Operand(0)
+				if actualType.IsAConstant().IsNil() || assertedType.IsAConstant().IsNil() {
+					return nil, nil, fr.errorAt(inst, errors.New("interp: unimplemented: type assert with non-constant interface value"))
+				}
+				assertOk := uint64(0)
+				if llvm.ConstExtractValue(actualType.Initializer(), []uint32{0}) == assertedType {
+					assertOk = 1
+				}
+				fr.locals[inst] = &LocalValue{fr.Eval, llvm.ConstInt(fr.Mod.Context().Int1Type(), assertOk, false)}
+			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, errors.New("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, errors.New("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, errors.New("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.
+				// TODO: print an error when executing runtime._panic (with the
+				// exact error message it would print at runtime).
+				var params []llvm.Value
+				for i := 0; i < inst.OperandsCount()-1; i++ {
+					operand := fr.getLocal(inst.Operand(i)).Value()
+					fr.markDirty(operand)
+					params = append(params, operand)
+				}
+				// TODO: accurate debug info, including call chain
+				fr.builder.CreateCall(callee, params, inst.Name())
+			case !callee.IsAFunction().IsNil() && callee.IsDeclaration():
+				// external functions
+				var params []llvm.Value
+				for i := 0; i < inst.OperandsCount()-1; i++ {
+					operand := fr.getLocal(inst.Operand(i)).Value()
+					fr.markDirty(operand)
+					params = append(params, operand)
+				}
+				// TODO: accurate debug info, including call chain
+				result := fr.builder.CreateCall(callee, params, inst.Name())
+				if inst.Type().TypeKind() != llvm.VoidTypeKind {
+					fr.markDirty(result)
+					fr.locals[inst] = &LocalValue{fr.Eval, result}
+				}
+			case !callee.IsAFunction().IsNil():
+				// regular function
+				var params []Value
+				dirtyParams := false
+				for i := 0; i < inst.OperandsCount()-1; i++ {
+					local := fr.getLocal(inst.Operand(i))
+					if !local.IsConstant() {
+						dirtyParams = true
+					}
+					params = append(params, local)
+				}
+				var ret Value
+				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
+					// is known at compile time which side effects it invokes.
+					// This means the function can be called at runtime and the
+					// affected globals can be marked dirty at compile time.
+					llvmParams := make([]llvm.Value, len(params))
+					for i, param := range params {
+						llvmParams[i] = param.Value()
+					}
+					result := fr.builder.CreateCall(callee, llvmParams, inst.Name())
+					ret = &LocalValue{fr.Eval, result}
+					// mark all mentioned globals as dirty
+					for global := range scanResult.mentionsGlobals {
+						fr.markDirty(global)
+					}
+				} else {
+					// Side effect is one of:
+					//   * None: no side effects, can be fully interpreted at
+					//     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, indent+"    ")
+					if err != nil {
+						// Record this function call in the backtrace.
+						err.Traceback = append(err.Traceback, ErrorLine{
+							Pos:  getPosition(inst),
+							Inst: inst,
+						})
+						return nil, nil, err
+					}
+				}
+				if inst.Type().TypeKind() != llvm.VoidTypeKind {
+					fr.locals[inst] = ret
+				}
+			default:
+				// function pointers, etc.
+				return nil, nil, fr.unsupportedInstructionError(inst)
+			}
+		case !inst.IsAExtractValueInst().IsNil():
+			agg := fr.getLocal(inst.Operand(0)).(*LocalValue) // must be constant
+			indices := inst.Indices()
+			if agg.Underlying.IsConstant() {
+				newValue := llvm.ConstExtractValue(agg.Underlying, indices)
+				fr.locals[inst] = fr.getValue(newValue)
+			} else {
+				if len(indices) != 1 {
+					return nil, nil, fr.errorAt(inst, errors.New("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())}
+			}
+		case !inst.IsAInsertValueInst().IsNil():
+			agg := fr.getLocal(inst.Operand(0)).(*LocalValue) // must be constant
+			val := fr.getLocal(inst.Operand(1))
+			indices := inst.Indices()
+			if agg.IsConstant() && val.IsConstant() {
+				newValue := llvm.ConstInsertValue(agg.Underlying, val.Value(), indices)
+				fr.locals[inst] = &LocalValue{fr.Eval, newValue}
+			} else {
+				if len(indices) != 1 {
+					return nil, nil, fr.errorAt(inst, errors.New("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())}
+			}
+		case !inst.IsASelectInst().IsNil():
+			// var result T
+			// if cond {
+			//   result = x
+			// } else {
+			//   result = y
+			// }
+			// return result
+			cond := fr.getLocal(inst.Operand(0)).(*LocalValue).Underlying
+			x := fr.getLocal(inst.Operand(1)).(*LocalValue).Underlying
+			y := fr.getLocal(inst.Operand(2)).(*LocalValue).Underlying
+			fr.locals[inst] = &LocalValue{fr.Eval, fr.builder.CreateSelect(cond, x, y, "")}
+
+		case !inst.IsAReturnInst().IsNil() && inst.OperandsCount() == 0:
+			return nil, nil, nil // ret void
+		case !inst.IsAReturnInst().IsNil() && inst.OperandsCount() == 1:
+			return fr.getLocal(inst.Operand(0)), nil, nil
+		case !inst.IsABranchInst().IsNil() && inst.OperandsCount() == 3:
+			// conditional branch (if/then/else)
+			cond := fr.getLocal(inst.Operand(0)).Value()
+			if cond.Type() != fr.Mod.Context().Int1Type() {
+				return nil, nil, fr.errorAt(inst, errors.New("expected an i1 in a branch instruction"))
+			}
+			thenBB := inst.Operand(1)
+			elseBB := inst.Operand(2)
+			if !cond.IsAInstruction().IsNil() {
+				return nil, nil, fr.errorAt(inst, errors.New("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, errors.New("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, errors.New("branch was not true or false"))
+			}
+		case !inst.IsABranchInst().IsNil() && inst.OperandsCount() == 1:
+			// unconditional branch (goto)
+			return nil, []llvm.Value{inst.Operand(0)}, nil
+		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.
+			// This is a sentinel error value.
+			return nil, nil, errUnreachable
+
+		default:
+			return nil, nil, fr.unsupportedInstructionError(inst)
+		}
+	}
+
+	panic("interp: reached end of basic block without terminator")
+}
+
+// Get the Value for an operand, which is a constant value of some sort.
+func (fr *frame) getLocal(v llvm.Value) Value {
+	if ret, ok := fr.locals[v]; ok {
+		return ret
+	} else if value := fr.getValue(v); value != nil {
+		return value
+	} else {
+		// This should not happen under normal circumstances.
+		panic("cannot find value")
+	}
+}
@@ -1,88 +1,59 @@
-// Package interp is a partial evaluator of code run at package init time. See
-// the README in this package for details.
+// Package interp interprets Go package initializers as much as possible. This
+// avoid running them at runtime, improving code size and making other
+// optimizations possible.
 package interp

+// This file provides the overarching Eval object with associated (utility)
+// methods.
+
 import (
-	"fmt"
-	"os"
 	"strings"
-	"time"

 	"tinygo.org/x/go-llvm"
 )

-// Version of the interp package. It must be incremented whenever the interp
-// package is changed in a way that affects the output so that cached package
-// builds will be invalidated.
-// This version is independent of the TinyGo version number.
-const Version = 1
-
-// Enable extra checks, which should be disabled by default.
-// This may help track down bugs by adding a few more sanity checks.
-const checks = true
-
-// runner contains all state related to one interp run.
-type runner struct {
-	mod           llvm.Module
-	targetData    llvm.TargetData
-	builder       llvm.Builder
-	pointerSize   uint32                   // cached pointer size from the TargetData
-	i8ptrType     llvm.Type                // often used type so created in advance
-	maxAlign      int                      // maximum alignment of an object, alignment of runtime.alloc() result
-	debug         bool                     // log debug messages
-	pkgName       string                   // package name of the currently executing package
-	functionCache map[llvm.Value]*function // cache of compiled functions
-	objects       []object                 // slice of objects in memory
-	globals       map[llvm.Value]int       // map from global to index in objects slice
-	start         time.Time
-	callsExecuted uint64
+type Eval struct {
+	Mod             llvm.Module
+	TargetData      llvm.TargetData
+	Debug           bool
+	builder         llvm.Builder
+	dirtyGlobals    map[llvm.Value]struct{}
+	sideEffectFuncs map[llvm.Value]*sideEffectResult // cache of side effect scan results
 }

-func newRunner(mod llvm.Module, debug bool) *runner {
-	r := runner{
-		mod:           mod,
-		targetData:    llvm.NewTargetData(mod.DataLayout()),
-		debug:         debug,
-		functionCache: make(map[llvm.Value]*function),
-		objects:       []object{{}},
-		globals:       make(map[llvm.Value]int),
-		start:         time.Now(),
-	}
-	r.pointerSize = uint32(r.targetData.PointerSize())
-	r.i8ptrType = llvm.PointerType(mod.Context().Int8Type(), 0)
-	r.maxAlign = r.targetData.PrefTypeAlignment(r.i8ptrType) // assume pointers are maximally aligned (this is not always the case)
-	return &r
+// 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 runtime.initAll function as much as possible at compile time.
-// Set debug to true if it should print output while running.
+// Run evaluates the function with the given name and then eliminates all
+// callers.
 func Run(mod llvm.Module, debug bool) error {
-	r := newRunner(mod, debug)
+	if debug {
+		println("\ncompile-time evaluation:")
+	}

-	initAll := mod.NamedFunction("runtime.initAll")
+	name := "runtime.initAll"
+	e := &Eval{
+		Mod:          mod,
+		TargetData:   llvm.NewTargetData(mod.DataLayout()),
+		Debug:        debug,
+		dirtyGlobals: map[llvm.Value]struct{}{},
+	}
+	e.builder = mod.Context().NewBuilder()
+
+	initAll := mod.NamedFunction(name)
 	bb := initAll.EntryBasicBlock()
-
-	// Create a builder, to insert instructions that could not be evaluated at
-	// compile time.
-	r.builder = mod.Context().NewBuilder()
-	defer r.builder.Dispose()
-
 	// 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.
-	r.builder.SetInsertPointBefore(bb.FirstInstruction())
-	dummy := r.builder.CreateAlloca(r.mod.Context().Int8Type(), "dummy")
-	r.builder.SetInsertPointBefore(dummy)
-	defer dummy.EraseFromParentAsInstruction()
-
-	// Get a list if init calls. A runtime.initAll might look something like this:
-	// func initAll() {
-	//     unsafe.init()
-	//     machine.init()
-	//     runtime.init()
-	// }
-	// This function gets a list of these call instructions.
+	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 {
@@ -92,175 +63,99 @@ func Run(mod llvm.Module, debug bool) error {
 			break // ret void
 		}
 		if inst.IsACallInst().IsNil() || inst.CalledValue().IsAFunction().IsNil() {
-			return errorAt(inst, "interp: expected all instructions in "+initAll.Name()+" to be direct calls")
+			return errorAt(inst, "interp: expected all instructions in "+name+" to be direct calls")
 		}
 		initCalls = append(initCalls, inst)
 	}

-	// Run initializers for each package. Once the package initializer is
-	// finished, the call to the package initializer can be removed.
+	// Do this in a separate step to avoid corrupting the iterator above.
+	undefPtr := llvm.Undef(llvm.PointerType(mod.Context().Int8Type(), 0))
 	for _, call := range initCalls {
 		initName := call.CalledValue().Name()
 		if !strings.HasSuffix(initName, ".init") {
-			return errorAt(call, "interp: expected all instructions in "+initAll.Name()+" to be *.init() calls")
+			return errorAt(call, "interp: expected all instructions in "+name+" to be *.init() calls")
 		}
-		r.pkgName = initName[:len(initName)-len(".init")]
+		pkgName := initName[:len(initName)-5]
 		fn := call.CalledValue()
-		if r.debug {
-			fmt.Fprintln(os.Stderr, "call:", fn.Name())
-		}
-		_, mem, callErr := r.run(r.getFunction(fn), nil, nil, "    ")
-		if callErr != nil {
-			if isRecoverableError(callErr.Err) {
-				if r.debug {
-					fmt.Fprintln(os.Stderr, "not interpreting", r.pkgName, "because of error:", callErr.Error())
-				}
-				mem.revert()
-				continue
-			}
-			return callErr
-		}
 		call.EraseFromParentAsInstruction()
-		for index, obj := range mem.objects {
-			r.objects[index] = obj
+		evalPkg := evalPackage{
+			Eval:        e,
+			packagePath: pkgName,
 		}
-	}
-	r.pkgName = ""
-
-	// Update all global variables in the LLVM module.
-	mem := memoryView{r: r}
-	for _, obj := range r.objects {
-		if obj.llvmGlobal.IsNil() {
-			continue
-		}
-		if obj.buffer == nil {
-			continue
-		}
-		initializer, err := obj.buffer.toLLVMValue(obj.llvmGlobal.Type().ElementType(), &mem)
-		if err == errInvalidPtrToIntSize {
-			// This can happen when a previous interp run did not have the
-			// correct LLVM type for a global and made something up. In that
-			// case, some fields could be written out as a series of (null)
-			// bytes even though they actually contain a pointer value.
-			// As a fallback, use asRawValue to get something of the correct
-			// memory layout.
-			initializer, err := obj.buffer.asRawValue(r).rawLLVMValue(&mem)
-			if err != nil {
-				return err
-			}
-			initializerType := initializer.Type()
-			newGlobal := llvm.AddGlobal(mod, initializerType, obj.llvmGlobal.Name()+".tmp")
-			newGlobal.SetInitializer(initializer)
-			newGlobal.SetLinkage(obj.llvmGlobal.Linkage())
-			newGlobal.SetAlignment(obj.llvmGlobal.Alignment())
-			// TODO: copy debug info, unnamed_addr, ...
-			bitcast := llvm.ConstBitCast(newGlobal, obj.llvmGlobal.Type())
-			obj.llvmGlobal.ReplaceAllUsesWith(bitcast)
-			name := obj.llvmGlobal.Name()
-			obj.llvmGlobal.EraseFromParentAsGlobal()
-			newGlobal.SetName(name)
-			continue
+		_, err := evalPkg.function(fn, []Value{&LocalValue{e, undefPtr}, &LocalValue{e, undefPtr}}, "")
+		if err == errUnreachable {
+			break
 		}
 		if err != nil {
 			return err
 		}
-		if checks && initializer.Type() != obj.llvmGlobal.Type().ElementType() {
-			panic("initializer type mismatch")
-		}
-		obj.llvmGlobal.SetInitializer(initializer)
 	}

 	return nil
 }

-// RunFunc evaluates a single package initializer at compile time.
-// Set debug to true if it should print output while running.
-func RunFunc(fn llvm.Value, debug bool) error {
-	// Create and initialize *runner object.
-	mod := fn.GlobalParent()
-	r := newRunner(mod, debug)
-	initName := fn.Name()
-	if !strings.HasSuffix(initName, ".init") {
-		return errorAt(fn, "interp: unexpected function name (expected *.init)")
+// 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{
+		evalPackage: e,
+		fn:          fn,
+		locals:      make(map[llvm.Value]Value),
 	}
-	r.pkgName = initName[:len(initName)-len(".init")]
-
-	// Create new function with the interp result.
-	newFn := llvm.AddFunction(mod, fn.Name()+".tmp", fn.Type().ElementType())
-	newFn.SetLinkage(fn.Linkage())
-	newFn.SetVisibility(fn.Visibility())
-	entry := mod.Context().AddBasicBlock(newFn, "entry")
-
-	// Create a builder, to insert instructions that could not be evaluated at
-	// compile time.
-	r.builder = mod.Context().NewBuilder()
-	defer r.builder.Dispose()
-	r.builder.SetInsertPointAtEnd(entry)
-
-	// Copy debug information.
-	subprogram := fn.Subprogram()
-	if !subprogram.IsNil() {
-		newFn.SetSubprogram(subprogram)
-		r.builder.SetCurrentDebugLocation(subprogram.SubprogramLine(), 0, subprogram, llvm.Metadata{})
+	for i, param := range fn.Params() {
+		fr.locals[param] = params[i]
 	}

-	// Run the initializer, filling the .init.tmp function.
-	if r.debug {
-		fmt.Fprintln(os.Stderr, "interp:", fn.Name())
-	}
-	_, pkgMem, callErr := r.run(r.getFunction(fn), nil, nil, "    ")
-	if callErr != nil {
-		if isRecoverableError(callErr.Err) {
-			// Could not finish, but could recover from it.
-			if r.debug {
-				fmt.Fprintln(os.Stderr, "not interpreting", r.pkgName, "because of error:", callErr.Error())
-			}
-			newFn.EraseFromParentAsFunction()
-			return nil
+	bb := fn.EntryBasicBlock()
+	var lastBB llvm.BasicBlock
+	for {
+		retval, outgoing, err := fr.evalBasicBlock(bb, lastBB, indent)
+		if outgoing == nil {
+			// returned something (a value or void, or an error)
+			return retval, err
 		}
-		return callErr
+		if len(outgoing) > 1 {
+			panic("unimplemented: multiple outgoing blocks")
+		}
+		next := outgoing[0]
+		if next.IsABasicBlock().IsNil() {
+			panic("did not switch to a basic block")
+		}
+		lastBB = bb
+		bb = next.AsBasicBlock()
 	}
-	for index, obj := range pkgMem.objects {
-		r.objects[index] = obj
-	}
-
-	// Update globals with values determined while running the initializer above.
-	mem := memoryView{r: r}
-	for _, obj := range r.objects {
-		if obj.llvmGlobal.IsNil() {
-			continue
-		}
-		if obj.buffer == nil {
-			continue
-		}
-		initializer, err := obj.buffer.toLLVMValue(obj.llvmGlobal.Type().ElementType(), &mem)
-		if err != nil {
-			return err
-		}
-		if checks && initializer.Type() != obj.llvmGlobal.Type().ElementType() {
-			panic("initializer type mismatch")
-		}
-		obj.llvmGlobal.SetInitializer(initializer)
-	}
-
-	// Finalize: remove the old init function and replace it with the new
-	// (.init.tmp) function.
-	r.builder.CreateRetVoid()
-	fnName := fn.Name()
-	fn.ReplaceAllUsesWith(newFn)
-	fn.EraseFromParentAsFunction()
-	newFn.SetName(fnName)
-
-	return nil
 }

-// getFunction returns the compiled version of the given LLVM function. It
-// compiles the function if necessary and caches the result.
-func (r *runner) getFunction(llvmFn llvm.Value) *function {
-	if fn, ok := r.functionCache[llvmFn]; ok {
-		return fn
-	}
-	fn := r.compileFunction(llvmFn)
-	r.functionCache[llvmFn] = fn
-	return fn
+// getValue determines what kind of LLVM value it gets and returns the
+// appropriate Value type.
+func (e *Eval) getValue(v llvm.Value) Value {
+	return &LocalValue{e, v}
+}
+
+// markDirty marks the passed-in LLVM value dirty, recursively. For example,
+// when it encounters a constant GEP on a global, it marks the global dirty.
+func (e *Eval) markDirty(v llvm.Value) {
+	if !v.IsAGlobalVariable().IsNil() {
+		if v.IsGlobalConstant() {
+			return
+		}
+		if _, ok := e.dirtyGlobals[v]; !ok {
+			e.dirtyGlobals[v] = struct{}{}
+			e.sideEffectFuncs = nil // re-calculate all side effects
+		}
+	} else if v.IsConstant() {
+		if v.OperandsCount() >= 2 && !v.Operand(0).IsAGlobalVariable().IsNil() {
+			// looks like a constant getelementptr of a global.
+			// TODO: find a way to make sure it really is: v.Opcode() returns 0.
+			e.markDirty(v.Operand(0))
+			return
+		}
+		return // nothing to mark
+	} else if !v.IsAGetElementPtrInst().IsNil() {
+		panic("interp: todo: GEP")
+	} else {
+		// Not constant and not a global or GEP so doesn't have to be marked
+		// non-constant.
+	}
 }
@@ -3,7 +3,6 @@ package interp
 import (
 	"io/ioutil"
 	"os"
-	"regexp"
 	"strings"
 	"testing"

@@ -13,9 +12,9 @@ import (
 func TestInterp(t *testing.T) {
 	for _, name := range []string{
 		"basic",
-		"phi",
 		"slice-copy",
 		"consteval",
+		"map",
 		"interface",
 	} {
 		name := name // make tc local to this closure
@@ -42,29 +41,9 @@ func runTest(t *testing.T, pathPrefix string) {
 	// Perform the transform.
 	err = Run(mod, false)
 	if err != nil {
-		if err, match := err.(*Error); match {
-			println(err.Error())
-			if !err.Inst.IsNil() {
-				err.Inst.Dump()
-				println()
-			}
-			if len(err.Traceback) > 0 {
-				println("\ntraceback:")
-				for _, line := range err.Traceback {
-					println(line.Pos.String() + ":")
-					line.Inst.Dump()
-					println()
-				}
-			}
-		}
 		t.Fatal(err)
 	}

-	// To be sure, verify that the module is still valid.
-	if llvm.VerifyModule(mod, llvm.PrintMessageAction) != nil {
-		t.FailNow()
-	}
-
 	// Run some cleanup passes to get easy-to-read outputs.
 	pm := llvm.NewPassManager()
 	defer pm.Dispose()
@@ -87,8 +66,6 @@ func runTest(t *testing.T, pathPrefix string) {
 	}
 }

-var alignRegexp = regexp.MustCompile(", align [0-9]+$")
-
 // fuzzyEqualIR returns true if the two LLVM IR strings passed in are roughly
 // equal. That means, only relevant lines are compared (excluding comments
 // etc.).
@@ -98,18 +75,8 @@ func fuzzyEqualIR(s1, s2 string) bool {
 	if len(lines1) != len(lines2) {
 		return false
 	}
-	for i, line1 := range lines1 {
-		line2 := lines2[i]
-		match1 := alignRegexp.MatchString(line1)
-		match2 := alignRegexp.MatchString(line2)
-		if match1 != match2 {
-			// Only one of the lines has the align keyword. Remove it.
-			// This is a change to make the test work in both LLVM 10 and LLVM
-			// 11 (LLVM 11 appears to automatically add alignment everywhere).
-			line1 = alignRegexp.ReplaceAllString(line1, "")
-			line2 = alignRegexp.ReplaceAllString(line2, "")
-		}
-		if line1 != line2 {
+	for i, line := range lines1 {
+		if line != lines2[i] {
 			return false
 		}
 	}
@@ -0,0 +1,253 @@
+package interp
+
+import (
+	"errors"
+	"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)
+	sideEffectLimited                              // has side effects, but the effects are known
+	sideEffectAll                                  // has unknown side effects
+)
+
+// sideEffectResult contains the scan results after scanning a function for side
+// effects (recursively).
+type sideEffectResult struct {
+	severity        sideEffectSeverity
+	mentionsGlobals map[llvm.Value]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 *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}, 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.typeAssert":
+		return &sideEffectResult{severity: sideEffectNone}, 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, nil
+	}
+	result := &sideEffectResult{
+		severity:        sideEffectInProgress,
+		mentionsGlobals: map[llvm.Value]struct{}{},
+	}
+	e.sideEffectFuncs[fn] = result
+	dirtyLocals := map[llvm.Value]struct{}{}
+	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")
+			}
+
+			// Check for any globals mentioned anywhere in the function. Assume
+			// any mentioned globals may be read from or written to when
+			// executed, thus must be marked dirty with a call.
+			for i := 0; i < inst.OperandsCount(); i++ {
+				operand := inst.Operand(i)
+				if !operand.IsAGlobalVariable().IsNil() {
+					result.mentionsGlobals[operand] = struct{}{}
+				}
+			}
+
+			switch inst.InstructionOpcode() {
+			case llvm.IndirectBr, llvm.Invoke:
+				// Not emitted by the compiler.
+				return nil, e.errorAt(inst, errors.New("unknown instructions"))
+			case llvm.Call:
+				child := inst.CalledValue()
+				if !child.IsAInlineAsm().IsNil() {
+					// Inline assembly. This most likely has side effects.
+					// Assume they're only limited side effects, similar to
+					// external function calls.
+					result.updateSeverity(sideEffectLimited)
+					continue
+				}
+				if child.IsAFunction().IsNil() {
+					// Indirect call?
+					// In any case, we can't know anything here about what it
+					// affects exactly so mark this function as invoking all
+					// possible side effects.
+					result.updateSeverity(sideEffectAll)
+					continue
+				}
+				if child.IsDeclaration() {
+					// External function call. Assume only limited side effects
+					// (no affected globals, etc.).
+					switch child.Name() {
+					case "runtime.typeAssert":
+						continue // implemented in interp
+					case "runtime.interfaceImplements":
+						continue // implemented in interp
+					}
+					if e.hasLocalSideEffects(dirtyLocals, inst) {
+						result.updateSeverity(sideEffectLimited)
+					}
+					continue
+				}
+				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
+				case sideEffectLimited:
+					// The return value may be problematic.
+					if e.hasLocalSideEffects(dirtyLocals, inst) {
+						result.updateSeverity(sideEffectLimited)
+					}
+				case sideEffectAll:
+					result.updateSeverity(sideEffectAll)
+				default:
+					panic("unreachable")
+				}
+			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)
+				}
+			case llvm.IntToPtr:
+				// Pointer casts are not yet supported.
+				result.updateSeverity(sideEffectLimited)
+			default:
+				// Ignore most instructions.
+				// Check this list for completeness:
+				// https://godoc.org/github.com/llvm-mirror/llvm/bindings/go/llvm#Opcode
+			}
+		}
+	}
+
+	if result.severity == sideEffectInProgress {
+		// No side effect was reported for this function.
+		result.severity = sideEffectNone
+	}
+	return result, nil
+}
+
+// hasLocalSideEffects checks whether the given instruction flows into a branch
+// or return instruction, in which case the whole function must be marked as
+// having side effects and be called at runtime.
+func (e *Eval) hasLocalSideEffects(dirtyLocals map[llvm.Value]struct{}, inst llvm.Value) bool {
+	if _, ok := dirtyLocals[inst]; ok {
+		// It is already known that this local is dirty.
+		return true
+	}
+
+	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() {
+		case llvm.Br, llvm.Switch:
+			// A branch on a dirty value makes this function dirty: it cannot be
+			// interpreted at compile time so has to be run at runtime. It is
+			// marked as having side effects for this reason.
+			return true
+		case llvm.Ret:
+			// This function returns a dirty value so it is itself marked as
+			// dirty to make sure it is called at runtime.
+			return true
+		case llvm.Store:
+			ptr := user.Operand(1)
+			if !ptr.IsAGlobalVariable().IsNil() {
+				// Store to a global variable.
+				// Already handled in (*Eval).hasSideEffects.
+				continue
+			}
+			// 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.
+			// For a list:
+			// https://godoc.org/github.com/llvm-mirror/llvm/bindings/go/llvm#Opcode
+			dirtyLocals[user] = struct{}{}
+			if e.hasLocalSideEffects(dirtyLocals, user) {
+				return true
+			}
+		}
+	}
+
+	// No side effects found.
+	return false
+}
+
+// updateSeverity sets r.severity to the max of r.severity and severity,
+// conservatively assuming the worst severity.
+func (r *sideEffectResult) updateSeverity(severity sideEffectSeverity) {
+	if severity > r.severity {
+		r.severity = severity
+	}
+}
+
+// updateSeverity updates the severity with the severity of the child severity,
+// like in a function call. This means it also copies the mentioned globals.
+func (r *sideEffectResult) update(child *sideEffectResult) {
+	r.updateSeverity(child.severity)
+	for global := range child.mentionsGlobals {
+		r.mentionsGlobals[global] = struct{}{}
+	}
+}
@@ -0,0 +1,95 @@
+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},
+	{"callTypeAssert", sideEffectNone, nil},
+	{"callInterfaceImplements", sideEffectNone, 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)
+		}
+	}
+}
@@ -4,11 +4,6 @@ target triple = "x86_64--linux"
@main.v1 = internal global i64 0
@main.nonConst1 = global [4 x i64] zeroinitializer
@main.nonConst2 = global i64 0
-@main.someArray = global [8 x {i16, i32}] zeroinitializer
-@main.exportedValue = global [1 x i16*] [i16* @main.exposedValue1]
-@main.exposedValue1 = global i16 0
-@main.exposedValue2 = global i16 0
-@main.insertedValue = global {i8, i32, {float, {i64, i16}}} zeroinitializer

 declare void @runtime.printint64(i64) unnamed_addr

@@ -52,33 +47,6 @@ entry:
  %value2 = load i64, i64* %gep2
  store i64 %value2, i64* @main.nonConst2

-  ; Test that the following GEP works:
-  ;     var someArray
-  ;     modifyExternal(&someArray[3].field1)
-  %gep3 = getelementptr [8 x {i16, i32}], [8 x {i16, i32}]* @main.someArray, i32 0, i32 3, i32 1
-  call void @modifyExternal(i32* %gep3)
-
-  ; Test that marking a value as external also marks all referenced values.
-  call void @modifyExternal(i32* bitcast ([1 x i16*]* @main.exportedValue to i32*))
-  store i16 5, i16* @main.exposedValue1
-
-  ; Test that this even propagates through functions.
-  call void @modifyExternal(i32* bitcast (void ()* @willModifyGlobal to i32*))
-  store i16 7, i16* @main.exposedValue2
-
-  ; Test switch statement.
-  %switch1 = call i64 @testSwitch(i64 1) ; 1 returns 6
-  %switch2 = call i64 @testSwitch(i64 9) ; 9 returns the default value -1
-  call void @runtime.printint64(i64 %switch1)
-  call void @runtime.printint64(i64 %switch2)
-
-  ; Test extractvalue/insertvalue with multiple operands.
-  %agg = call {i8, i32, {float, {i64, i16}}} @nestedStruct()
-  %elt = extractvalue {i8, i32, {float, {i64, i16}}} %agg, 2, 1, 0
-  call void @runtime.printint64(i64 %elt)
-  %agg2 = insertvalue {i8, i32, {float, {i64, i16}}} %agg, i64 5, 2, 1, 0
-  store {i8, i32, {float, {i64, i16}}} %agg2, {i8, i32, {float, {i64, i16}}}* @main.insertedValue
-
  ret void
 }

@@ -90,35 +58,3 @@ entry:
 }

 declare i64 @someValue()
-
-declare void @modifyExternal(i32*)
-
-; This function will modify an external value. By passing this function as a
-; function pointer to an external function, @main.exposedValue2 should be
-; marked as external.
-define void @willModifyGlobal() {
-entry:
-  store i16 8, i16* @main.exposedValue2
-  ret void
-}
-
-define i64 @testSwitch(i64 %val) {
-entry:
-  ; Test switch statement.
-  switch i64 %val, label %otherwise [ i64 0, label %zero
-                                      i64 1, label %one
-                                      i64 2, label %two ]
-zero:
-  ret i64 5
-
-one:
-  ret i64 6
-
-two:
-  ret i64 7
-
-otherwise:
-  ret i64 -1
-}
-
-declare {i8, i32, {float, {i64, i16}}} @nestedStruct()
@@ -3,11 +3,6 @@ target triple = "x86_64--linux"

@main.nonConst1 = local_unnamed_addr global [4 x i64] zeroinitializer
@main.nonConst2 = local_unnamed_addr global i64 0
-@main.someArray = global [8 x { i16, i32 }] zeroinitializer
-@main.exportedValue = global [1 x i16*] [i16* @main.exposedValue1]
-@main.exposedValue1 = global i16 0
-@main.exposedValue2 = local_unnamed_addr global i16 0
-@main.insertedValue = local_unnamed_addr global { i8, i32, { float, { i64, i16 } } } zeroinitializer

 declare void @runtime.printint64(i64) unnamed_addr

@@ -21,24 +16,6 @@ entry:
  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
-  call void @modifyExternal(i32* getelementptr inbounds ([8 x { i16, i32 }], [8 x { i16, i32 }]* @main.someArray, i32 0, i32 3, i32 1))
-  call void @modifyExternal(i32* bitcast ([1 x i16*]* @main.exportedValue to i32*))
-  store i16 5, i16* @main.exposedValue1
-  call void @modifyExternal(i32* bitcast (void ()* @willModifyGlobal to i32*))
-  store i16 7, i16* @main.exposedValue2
-  call void @runtime.printint64(i64 6)
-  call void @runtime.printint64(i64 -1)
-  %agg = call { i8, i32, { float, { i64, i16 } } } @nestedStruct()
-  %elt.agg = extractvalue { i8, i32, { float, { i64, i16 } } } %agg, 2
-  %elt.agg1 = extractvalue { float, { i64, i16 } } %elt.agg, 1
-  %elt = extractvalue { i64, i16 } %elt.agg1, 0
-  call void @runtime.printint64(i64 %elt)
-  %agg2.agg0 = extractvalue { i8, i32, { float, { i64, i16 } } } %agg, 2
-  %agg2.agg1 = extractvalue { float, { i64, i16 } } %agg2.agg0, 1
-  %agg2.insertvalue2 = insertvalue { i64, i16 } %agg2.agg1, i64 5, 0
-  %agg2.insertvalue1 = insertvalue { float, { i64, i16 } } %agg2.agg0, { i64, i16 } %agg2.insertvalue2, 1
-  %agg2.insertvalue0 = insertvalue { i8, i32, { float, { i64, i16 } } } %agg, { float, { i64, i16 } } %agg2.insertvalue1, 2
-  store { i8, i32, { float, { i64, i16 } } } %agg2.insertvalue0, { i8, i32, { float, { i64, i16 } } }* @main.insertedValue
  ret void
 }

@@ -50,34 +27,3 @@ entry:
 }

 declare i64 @someValue() local_unnamed_addr
-
-declare void @modifyExternal(i32*) local_unnamed_addr
-
-define void @willModifyGlobal() {
-entry:
-  store i16 8, i16* @main.exposedValue2
-  ret void
-}
-
-define i64 @testSwitch(i64 %val) local_unnamed_addr {
-entry:
-  switch i64 %val, label %otherwise [
-    i64 0, label %zero
-    i64 1, label %one
-    i64 2, label %two
-  ]
-
-zero:                                             ; preds = %entry
-  ret i64 5
-
-one:                                              ; preds = %entry
-  ret i64 6
-
-two:                                              ; preds = %entry
-  ret i64 7
-
-otherwise:                                        ; preds = %entry
-  ret i64 -1
-}
-
-declare { i8, i32, { float, { i64, i16 } } } @nestedStruct() local_unnamed_addr
@@ -1,16 +1,17 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64--linux"

-%runtime.typecodeID = type { %runtime.typecodeID*, i64, %runtime.interfaceMethodInfo* }
+%runtime.typecodeID = type { %runtime.typecodeID*, i64 }
 %runtime.interfaceMethodInfo = type { i8*, i64 }
+%runtime.typeInInterface = type { %runtime.typecodeID*, %runtime.interfaceMethodInfo* }

@main.v1 = global i1 0
-@"reflect/types.type:named:main.foo" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i64 0, %runtime.interfaceMethodInfo* null }
-@"reflect/types.typeid:named:main.foo" = external constant i8
+@"reflect/types.type:named:main.foo" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i64 0 }
@"reflect/types.type:basic:int" = external constant %runtime.typecodeID
+@"typeInInterface:reflect/types.type:named:main.foo" = private constant %runtime.typeInInterface { %runtime.typecodeID* @"reflect/types.type:named:main.foo", %runtime.interfaceMethodInfo* null }


-declare i1 @runtime.typeAssert(i64, i8*, i8*, i8*)
+declare i1 @runtime.typeAssert(i64, %runtime.typecodeID*, i8*, i8*)

 define void @runtime.initAll() unnamed_addr {
 entry:
@@ -21,7 +22,7 @@ entry:
 define internal void @main.init() unnamed_addr {
 entry:
  ; Test type asserts.
-  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typecodeID* @"reflect/types.type:named:main.foo" to i64), i8* @"reflect/types.typeid:named:main.foo", i8* undef, i8* null)
+  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:named:main.foo" to i64), %runtime.typecodeID* @"reflect/types.type:named:main.foo", i8* undef, i8* null)
  store i1 %typecode, i1* @main.v1
  ret void
 }
@@ -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
+}
@@ -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
+}
@@ -1,31 +0,0 @@
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64--linux"
-
-@main.phiNodesResultA = global i8 0
-@main.phiNodesResultB = global i8 0
-
-define void @runtime.initAll() {
-  call void @main.init()
-  ret void
-}
-
-; PHI nodes always use the value from the previous block, even in a loop. This
-; means that the loop below should swap the values %a and %b on each iteration.
-; Previously there was a bug which resulted in %b getting the value 3 on the
-; second iteration while it should have gotten 1 (from the first iteration of
-; %for.loop).
-define internal void @main.init() {
-entry:
-  br label %for.loop
-
-for.loop:
-  %a = phi i8 [ 1, %entry ], [ %b, %for.loop ]
-  %b = phi i8 [ 3, %entry ], [ %a, %for.loop ]
-  %icmp = icmp eq i8 %a, 3
-  br i1 %icmp, label %for.done, label %for.loop
-
-for.done:
-  store i8 %a, i8* @main.phiNodesResultA
-  store i8 %b, i8* @main.phiNodesResultB
-  ret void
-}
@@ -1,9 +0,0 @@
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64--linux"
-
-@main.phiNodesResultA = local_unnamed_addr global i8 3
-@main.phiNodesResultB = local_unnamed_addr global i8 1
-
-define void @runtime.initAll() local_unnamed_addr {
-  ret void
-}
@@ -0,0 +1,78 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+%runtime.typecodeID = type { %runtime.typecodeID*, i64 }
+
+declare i1 @runtime.typeAssert(i64, %runtime.typecodeID*, i8*, i8*)
+declare i1 @runtime.interfaceImplements(i64, i8**)
+
+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
+}
+
+define i1 @callTypeAssert() {
+  ; Note: parameters are not realistic.
+  %ok = call i1 @runtime.typeAssert(i64 0, %runtime.typecodeID* null, i8* undef, i8* null)
+  ret i1 %ok
+}
+
+define i1 @callInterfaceImplements() {
+  ; Note: parameters are not realistic.
+  %ok = call i1 @runtime.interfaceImplements(i64 0, i8** null)
+  ret i1 %ok
+}
@@ -1,8 +1,6 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64--linux"

-@"main$alloc.1" = internal unnamed_addr constant [6 x i8] c"\05\00{\00\00\04"
-
 declare void @runtime.printuint8(i8) local_unnamed_addr

 declare void @runtime.printint16(i16) local_unnamed_addr
@@ -17,7 +15,6 @@ entry:
  call void @runtime.printuint8(i8 3)
  call void @runtime.printuint8(i8 3)
  call void @runtime.printint16(i16 5)
-  %int16SliceDst.val = load i16, i16* bitcast ([6 x i8]* @"main$alloc.1" to i16*)
-  call void @runtime.printint16(i16 %int16SliceDst.val)
+  call void @runtime.printint16(i16 5)
  ret void
 }
@@ -0,0 +1,121 @@
+package interp
+
+import (
+	"tinygo.org/x/go-llvm"
+)
+
+// Return a list of values (actually, instructions) where this value is used as
+// an operand.
+func getUses(value llvm.Value) []llvm.Value {
+	var uses []llvm.Value
+	use := value.FirstUse()
+	for !use.IsNil() {
+		uses = append(uses, use.User())
+		use = use.NextUse()
+	}
+	return uses
+}
+
+// getStringBytes loads the byte slice of a Go string represented as a
+// {ptr, len} pair.
+func getStringBytes(strPtr Value, strLen llvm.Value) []byte {
+	if !strLen.IsConstant() {
+		panic("getStringBytes with a non-constant length")
+	}
+	buf := make([]byte, strLen.ZExtValue())
+	for i := range buf {
+		gep, err := strPtr.GetElementPtr([]uint32{uint32(i)})
+		if err != nil {
+			panic(err) // TODO
+		}
+		c := gep.Load()
+		buf[i] = byte(c.ZExtValue())
+	}
+	return buf
+}
+
+// getLLVMIndices converts an []uint32 into an []llvm.Value, for use in
+// llvm.ConstGEP.
+func getLLVMIndices(int32Type llvm.Type, indices []uint32) []llvm.Value {
+	llvmIndices := make([]llvm.Value, len(indices))
+	for i, index := range indices {
+		llvmIndices[i] = llvm.ConstInt(int32Type, uint64(index), false)
+	}
+	return llvmIndices
+}
+
+// Return true if this type is a scalar value (integer or floating point), false
+// otherwise.
+func isScalar(t llvm.Type) bool {
+	switch t.TypeKind() {
+	case llvm.IntegerTypeKind, llvm.FloatTypeKind, llvm.DoubleTypeKind:
+		return true
+	default:
+		return false
+	}
+}
+
+// isPointerNil returns whether this is a nil pointer or not. The ok value
+// indicates whether the result is certain: if it is false the result boolean is
+// not valid.
+func isPointerNil(v llvm.Value) (result bool, ok bool) {
+	if !v.IsAConstantExpr().IsNil() {
+		switch v.Opcode() {
+		case llvm.IntToPtr:
+			// Whether a constant inttoptr is nil is easy to
+			// determine.
+			result, ok = isZero(v.Operand(0))
+			if ok {
+				return
+			}
+		case llvm.BitCast, llvm.GetElementPtr:
+			// These const instructions are just a kind of wrappers for the
+			// underlying pointer.
+			return isPointerNil(v.Operand(0))
+		}
+	}
+	if !v.IsAConstantPointerNull().IsNil() {
+		// A constant pointer null is always null, of course.
+		return true, true
+	}
+	if !v.IsAGlobalValue().IsNil() {
+		// A global value is never null.
+		return false, true
+	}
+	return false, false // not valid
+}
+
+// isZero returns whether the value in v is the integer zero, and whether that
+// can be known right now.
+func isZero(v llvm.Value) (result bool, ok bool) {
+	if !v.IsAConstantExpr().IsNil() {
+		switch v.Opcode() {
+		case llvm.PtrToInt:
+			return isPointerNil(v.Operand(0))
+		}
+	}
+	if !v.IsAConstantInt().IsNil() {
+		val := v.ZExtValue()
+		return val == 0, true
+	}
+	return false, false // not valid
+}
+
+// unwrap returns the underlying value, with GEPs removed. This can be useful to
+// get the underlying global of a GEP pointer.
+func unwrap(value llvm.Value) llvm.Value {
+	for {
+		if !value.IsAConstantExpr().IsNil() {
+			switch value.Opcode() {
+			case llvm.GetElementPtr:
+				value = value.Operand(0)
+				continue
+			}
+		} else if !value.IsAGetElementPtrInst().IsNil() {
+			value = value.Operand(0)
+			continue
+		}
+		break
+	}
+	return value
+}
@@ -0,0 +1,419 @@
+package interp
+
+// This file provides a litte bit of abstraction around LLVM values.
+
+import (
+	"errors"
+	"strconv"
+
+	"tinygo.org/x/go-llvm"
+)
+
+// A Value is a LLVM value with some extra methods attached for easier
+// interpretation.
+type Value interface {
+	Value() llvm.Value                     // returns a LLVM value
+	Type() llvm.Type                       // equal to Value().Type()
+	IsConstant() bool                      // returns true if this value is a constant value
+	Load() llvm.Value                      // dereference a pointer
+	Store(llvm.Value)                      // store to a pointer
+	GetElementPtr([]uint32) (Value, error) // returns an interior pointer
+	String() string                        // string representation, for debugging
+}
+
+// A type that simply wraps a LLVM constant value.
+type LocalValue struct {
+	Eval       *Eval
+	Underlying llvm.Value
+}
+
+// Value implements Value by returning the constant value itself.
+func (v *LocalValue) Value() llvm.Value {
+	return v.Underlying
+}
+
+func (v *LocalValue) Type() llvm.Type {
+	return v.Underlying.Type()
+}
+
+func (v *LocalValue) IsConstant() bool {
+	if _, ok := v.Eval.dirtyGlobals[unwrap(v.Underlying)]; ok {
+		return false
+	}
+	return v.Underlying.IsConstant()
+}
+
+// Load loads a constant value if this is a constant pointer.
+func (v *LocalValue) Load() llvm.Value {
+	if !v.Underlying.IsAGlobalVariable().IsNil() {
+		return v.Underlying.Initializer()
+	}
+	switch v.Underlying.Opcode() {
+	case llvm.GetElementPtr:
+		indices := v.getConstGEPIndices()
+		if indices[0] != 0 {
+			panic("invalid GEP")
+		}
+		global := v.Eval.getValue(v.Underlying.Operand(0))
+		agg := global.Load()
+		return llvm.ConstExtractValue(agg, indices[1:])
+	case llvm.BitCast:
+		panic("interp: load from a bitcast")
+	default:
+		panic("interp: load from a constant")
+	}
+}
+
+// Store stores to the underlying value if the value type is a pointer type,
+// otherwise it panics.
+func (v *LocalValue) Store(value llvm.Value) {
+	if !v.Underlying.IsAGlobalVariable().IsNil() {
+		if !value.IsConstant() {
+			v.MarkDirty()
+			v.Eval.builder.CreateStore(value, v.Underlying)
+		} else {
+			v.Underlying.SetInitializer(value)
+		}
+		return
+	}
+	if !value.IsConstant() {
+		v.MarkDirty()
+		v.Eval.builder.CreateStore(value, v.Underlying)
+		return
+	}
+	switch v.Underlying.Opcode() {
+	case llvm.GetElementPtr:
+		indices := v.getConstGEPIndices()
+		if indices[0] != 0 {
+			panic("invalid GEP")
+		}
+		global := &LocalValue{v.Eval, v.Underlying.Operand(0)}
+		agg := global.Load()
+		agg = llvm.ConstInsertValue(agg, value, indices[1:])
+		global.Store(agg)
+		return
+	default:
+		panic("interp: store on a constant")
+	}
+}
+
+// GetElementPtr returns a GEP when the underlying value is of pointer type.
+func (v *LocalValue) GetElementPtr(indices []uint32) (Value, error) {
+	if !v.Underlying.IsAGlobalVariable().IsNil() {
+		int32Type := v.Underlying.Type().Context().Int32Type()
+		gep := llvm.ConstGEP(v.Underlying, getLLVMIndices(int32Type, indices))
+		return &LocalValue{v.Eval, gep}, nil
+	}
+	if !v.Underlying.IsAConstantExpr().IsNil() {
+		switch v.Underlying.Opcode() {
+		case llvm.GetElementPtr, llvm.IntToPtr, llvm.BitCast:
+			int32Type := v.Underlying.Type().Context().Int32Type()
+			llvmIndices := getLLVMIndices(int32Type, indices)
+			return &LocalValue{v.Eval, llvm.ConstGEP(v.Underlying, llvmIndices)}, nil
+		}
+	}
+	return nil, errors.New("interp: unknown GEP")
+}
+
+// stripPointerCasts removes all const bitcasts from pointer values, if there
+// are any.
+func (v *LocalValue) stripPointerCasts() *LocalValue {
+	value := v.Underlying
+	for {
+		if !value.IsAConstantExpr().IsNil() {
+			switch value.Opcode() {
+			case llvm.BitCast:
+				value = value.Operand(0)
+				continue
+			}
+		}
+		return &LocalValue{
+			Eval:       v.Eval,
+			Underlying: value,
+		}
+	}
+}
+
+func (v *LocalValue) String() string {
+	isConstant := "false"
+	if v.IsConstant() {
+		isConstant = "true"
+	}
+	return "&LocalValue{Type: " + v.Type().String() + ", IsConstant: " + isConstant + "}"
+}
+
+// getConstGEPIndices returns indices of this constant GEP, if this is a GEP
+// instruction. If it is not, the behavior is undefined.
+func (v *LocalValue) getConstGEPIndices() []uint32 {
+	indices := make([]uint32, v.Underlying.OperandsCount()-1)
+	for i := range indices {
+		operand := v.Underlying.Operand(i + 1)
+		indices[i] = uint32(operand.ZExtValue())
+	}
+	return indices
+}
+
+// MarkDirty marks this global as dirty, meaning that every load from and store
+// to this global (from now on) must be performed at runtime.
+func (v *LocalValue) MarkDirty() {
+	underlying := unwrap(v.Underlying)
+	if underlying.IsAGlobalVariable().IsNil() {
+		panic("trying to mark a non-global as dirty")
+	}
+	if !v.IsConstant() {
+		return // already dirty
+	}
+	v.Eval.dirtyGlobals[underlying] = struct{}{}
+}
+
+// MapValue implements a Go map which is created at compile time and stored as a
+// global variable.
+type MapValue struct {
+	Eval       *Eval
+	PkgName    string
+	Underlying llvm.Value
+	Keys       []Value
+	Values     []Value
+	KeySize    int
+	ValueSize  int
+	KeyType    llvm.Type
+	ValueType  llvm.Type
+}
+
+func (v *MapValue) newBucket() llvm.Value {
+	ctx := v.Eval.Mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+	bucketType := ctx.StructType([]llvm.Type{
+		llvm.ArrayType(ctx.Int8Type(), 8), // tophash
+		i8ptrType,                         // next bucket
+		llvm.ArrayType(v.KeyType, 8),      // key type
+		llvm.ArrayType(v.ValueType, 8),    // value type
+	}, false)
+	bucketValue := llvm.ConstNull(bucketType)
+	bucket := llvm.AddGlobal(v.Eval.Mod, bucketType, v.PkgName+"$mapbucket")
+	bucket.SetInitializer(bucketValue)
+	bucket.SetLinkage(llvm.InternalLinkage)
+	bucket.SetUnnamedAddr(true)
+	return bucket
+}
+
+// Value returns a global variable which is a pointer to the actual hashmap.
+func (v *MapValue) Value() llvm.Value {
+	if !v.Underlying.IsNil() {
+		return v.Underlying
+	}
+
+	ctx := v.Eval.Mod.Context()
+	i8ptrType := llvm.PointerType(ctx.Int8Type(), 0)
+
+	var firstBucketGlobal llvm.Value
+	if len(v.Keys) == 0 {
+		// there are no buckets
+		firstBucketGlobal = llvm.ConstPointerNull(i8ptrType)
+	} else {
+		// create initial bucket
+		firstBucketGlobal = v.newBucket()
+	}
+
+	// Insert each key/value pair in the hashmap.
+	bucketGlobal := firstBucketGlobal
+	for i, key := range v.Keys {
+		var keyBuf []byte
+		llvmKey := key.Value()
+		llvmValue := v.Values[i].Value()
+		if key.Type().TypeKind() == llvm.StructTypeKind && key.Type().StructName() == "runtime._string" {
+			keyPtr := llvm.ConstExtractValue(llvmKey, []uint32{0})
+			keyLen := llvm.ConstExtractValue(llvmKey, []uint32{1})
+			keyPtrVal := v.Eval.getValue(keyPtr)
+			keyBuf = getStringBytes(keyPtrVal, keyLen)
+		} else if key.Type().TypeKind() == llvm.IntegerTypeKind {
+			keyBuf = make([]byte, v.Eval.TargetData.TypeAllocSize(key.Type()))
+			n := key.Value().ZExtValue()
+			for i := range keyBuf {
+				keyBuf[i] = byte(n)
+				n >>= 8
+			}
+		} else if key.Type().TypeKind() == llvm.ArrayTypeKind &&
+			key.Type().ElementType().TypeKind() == llvm.IntegerTypeKind &&
+			key.Type().ElementType().IntTypeWidth() == 8 {
+			keyBuf = make([]byte, v.Eval.TargetData.TypeAllocSize(key.Type()))
+			for i := range keyBuf {
+				keyBuf[i] = byte(llvm.ConstExtractValue(llvmKey, []uint32{uint32(i)}).ZExtValue())
+			}
+		} else {
+			panic("interp: map key type not implemented: " + key.Type().String())
+		}
+		hash := v.hash(keyBuf)
+
+		if i%8 == 0 && i != 0 {
+			// Bucket is full, create a new one.
+			newBucketGlobal := v.newBucket()
+			zero := llvm.ConstInt(ctx.Int32Type(), 0, false)
+			newBucketPtr := llvm.ConstInBoundsGEP(newBucketGlobal, []llvm.Value{zero})
+			newBucketPtrCast := llvm.ConstBitCast(newBucketPtr, i8ptrType)
+			// insert pointer into old bucket
+			bucket := bucketGlobal.Initializer()
+			bucket = llvm.ConstInsertValue(bucket, newBucketPtrCast, []uint32{1})
+			bucketGlobal.SetInitializer(bucket)
+			// switch to next bucket
+			bucketGlobal = newBucketGlobal
+		}
+
+		tophashValue := llvm.ConstInt(ctx.Int8Type(), uint64(v.topHash(hash)), false)
+		bucket := bucketGlobal.Initializer()
+		bucket = llvm.ConstInsertValue(bucket, tophashValue, []uint32{0, uint32(i % 8)})
+		bucket = llvm.ConstInsertValue(bucket, llvmKey, []uint32{2, uint32(i % 8)})
+		bucket = llvm.ConstInsertValue(bucket, llvmValue, []uint32{3, uint32(i % 8)})
+		bucketGlobal.SetInitializer(bucket)
+	}
+
+	// Create the hashmap itself.
+	zero := llvm.ConstInt(ctx.Int32Type(), 0, false)
+	bucketPtr := llvm.ConstInBoundsGEP(firstBucketGlobal, []llvm.Value{zero})
+	hashmapType := v.Type()
+	hashmap := llvm.ConstNamedStruct(hashmapType, []llvm.Value{
+		llvm.ConstPointerNull(llvm.PointerType(hashmapType, 0)),                        // next
+		llvm.ConstBitCast(bucketPtr, i8ptrType),                                        // buckets
+		llvm.ConstInt(hashmapType.StructElementTypes()[2], uint64(len(v.Keys)), false), // count
+		llvm.ConstInt(ctx.Int8Type(), uint64(v.KeySize), false),                        // keySize
+		llvm.ConstInt(ctx.Int8Type(), uint64(v.ValueSize), false),                      // valueSize
+		llvm.ConstInt(ctx.Int8Type(), 0, false),                                        // bucketBits
+	})
+
+	// Create a pointer to this hashmap.
+	hashmapPtr := llvm.AddGlobal(v.Eval.Mod, hashmap.Type(), v.PkgName+"$map")
+	hashmapPtr.SetInitializer(hashmap)
+	hashmapPtr.SetLinkage(llvm.InternalLinkage)
+	hashmapPtr.SetUnnamedAddr(true)
+	v.Underlying = llvm.ConstInBoundsGEP(hashmapPtr, []llvm.Value{zero})
+	return v.Underlying
+}
+
+// Type returns type runtime.hashmap, which is the actual hashmap type.
+func (v *MapValue) Type() llvm.Type {
+	return v.Eval.Mod.GetTypeByName("runtime.hashmap")
+}
+
+func (v *MapValue) IsConstant() bool {
+	return true // TODO: dirty maps
+}
+
+// Load panics: maps are of reference type so cannot be dereferenced.
+func (v *MapValue) Load() llvm.Value {
+	panic("interp: load from a map")
+}
+
+// Store panics: maps are of reference type so cannot be stored to.
+func (v *MapValue) Store(value llvm.Value) {
+	panic("interp: store on a map")
+}
+
+// GetElementPtr panics: maps are of reference type so their (interior)
+// addresses cannot be calculated.
+func (v *MapValue) GetElementPtr(indices []uint32) (Value, error) {
+	return nil, errors.New("interp: GEP on a map")
+}
+
+// PutString does a map assign operation, assuming that the map is of type
+// map[string]T.
+func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) {
+	if !v.Underlying.IsNil() {
+		panic("map already created")
+	}
+
+	if valPtr.Underlying.Opcode() == llvm.BitCast {
+		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
+	}
+	value := valPtr.Load()
+	if v.ValueType.IsNil() {
+		v.ValueType = value.Type()
+		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
+			panic("interp: map store value type has the wrong size")
+		}
+	} else {
+		if value.Type() != v.ValueType {
+			panic("interp: map store value type is inconsistent")
+		}
+	}
+
+	keyType := v.Eval.Mod.GetTypeByName("runtime._string")
+	v.KeyType = keyType
+	key := llvm.ConstNull(keyType)
+	key = llvm.ConstInsertValue(key, keyBuf.Value(), []uint32{0})
+	key = llvm.ConstInsertValue(key, keyLen.Value(), []uint32{1})
+
+	// TODO: avoid duplicate keys
+	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
+	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+}
+
+// PutBinary does a map assign operation.
+func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
+	if !v.Underlying.IsNil() {
+		panic("map already created")
+	}
+
+	if valPtr.Underlying.Opcode() == llvm.BitCast {
+		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
+	}
+	value := valPtr.Load()
+	if v.ValueType.IsNil() {
+		v.ValueType = value.Type()
+		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
+			panic("interp: map store value type has the wrong size")
+		}
+	} else {
+		if value.Type() != v.ValueType {
+			panic("interp: map store value type is inconsistent")
+		}
+	}
+
+	if !keyPtr.Underlying.IsAConstantExpr().IsNil() {
+		if keyPtr.Underlying.Opcode() == llvm.BitCast {
+			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
+		} else if keyPtr.Underlying.Opcode() == llvm.GetElementPtr {
+			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
+		}
+	}
+	key := keyPtr.Load()
+	if v.KeyType.IsNil() {
+		v.KeyType = key.Type()
+		if int(v.Eval.TargetData.TypeAllocSize(v.KeyType)) != v.KeySize {
+			panic("interp: map store key type has the wrong size")
+		}
+	} else {
+		if key.Type() != v.KeyType {
+			panic("interp: map store key type is inconsistent")
+		}
+	}
+
+	// TODO: avoid duplicate keys
+	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
+	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+}
+
+// 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 (v *MapValue) hash(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 (v *MapValue) topHash(hash uint32) uint8 {
+	tophash := uint8(hash >> 24)
+	if tophash < 1 {
+		// 0 means empty slot, so make it bigger.
+		tophash += 1
+	}
+	return tophash
+}
+
+func (v *MapValue) String() string {
+	return "&MapValue{KeySize: " + strconv.Itoa(v.KeySize) + ", ValueSize: " + strconv.Itoa(v.ValueSize) + "}"
+}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Ayke van Laethem	4e07fc569c	main: add -json flag support to go env This is needed for VS Code support.	2020-05-08 14:50:37 +02:00
Ayke van Laethem	25e13d887f	loader: load packages using Go modules This commit replaces the existing ad-hoc package loader with a package loader that uses the x/tools/go/packages package to find all to-be-loaded packages.	2020-05-08 14:50:26 +02:00
Ayke van Laethem	51daa2a044	main: fix test subcommand It was broken for quite some time without anybody noticing...	2020-05-08 14:50:26 +02:00
Ayke van Laethem	f70dc70247	loader: merge roots from both Go and TinyGo in a cached directory This commit changes the way that packages are looked up. Instead of working around the loader package by modifying the GOROOT variable for specific packages, create a new GOROOT using symlinks. This GOROOT is cached for the specified configuration (Go version, underlying GOROOT path, TinyGo path, whether to override the syscall package). This will also enable go module support in the future.	2020-05-05 00:06:53 +02:00
Ayke van Laethem	f24bb1ceda	builder: move Go version code to goenv package This is necessary to avoid a circular dependency in the loader (which soon will need to read the Go version) and because it seems like a better place anyway.	2020-05-04 21:58:27 +02:00