builder: fixed a problem with multiple process build cases

Signed-off-by: deadprogram <ron@hybridgroup.com>

.circleci/config.yml

@@ -68,24 +68,27 @@ commands:
     steps:
       - restore_cache:
           keys:
-            - llvm-source-11-v1
+            - llvm-source-11-v2
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-11-v1
+          key: llvm-source-11-v2
           paths:
-            - llvm-project
+            - llvm-project/clang/lib/Headers
+            - llvm-project/clang/include
+            - llvm-project/lld/include
+            - llvm-project/llvm/include
   build-wasi-libc:
     steps:
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-v3
+            - wasi-libc-sysroot-v4
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-v3
+          key: wasi-libc-sysroot-v4
           paths:
             - lib/wasi-libc/sysroot
   test-linux:
@@ -108,10 +111,10 @@ commands:
       - run: go install -tags=llvm<<parameters.llvm>> .
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-systemclang-v2
+            - wasi-libc-sysroot-systemclang-v3
       - run: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-systemclang-v2
+          key: wasi-libc-sysroot-systemclang-v3
           paths:
             - lib/wasi-libc/sysroot
       - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./compiler ./interp ./transform .
@@ -132,6 +135,7 @@ commands:
       - run:
           name: "Install apt dependencies"
           command: |
+            sudo apt-get update
             sudo apt-get install \
                 gcc-arm-linux-gnueabihf \
                 libc6-dev-armel-cross \
@@ -153,12 +157,15 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-11-linux-v1-assert
+            - llvm-build-11-linux-v3-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
               # hack ninja to use less jobs
@@ -166,9 +173,10 @@ commands:
               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-v1-assert
+          key: llvm-build-11-linux-v3-assert
           paths:
             llvm-build
       - run: make ASSERT=1
@@ -176,6 +184,11 @@ 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:
@@ -190,6 +203,7 @@ commands:
       - run:
           name: "Install apt dependencies"
           command: |
+            sudo apt-get update
             sudo apt-get install \
                 gcc-arm-linux-gnueabihf \
                 libc6-dev-armel-cross \
@@ -211,12 +225,15 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-11-linux-v1-noassert
+            - llvm-build-11-linux-v3-noassert
       - 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
               # hack ninja to use less jobs
@@ -224,9 +241,10 @@ commands:
               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-v1-noassert
+          key: llvm-build-11-linux-v3-noassert
           paths:
             llvm-build
       - build-wasi-libc
@@ -268,8 +286,8 @@ commands:
       - run:
           name: "Install dependencies"
           command: |
-            curl https://dl.google.com/go/go1.15.5.darwin-amd64.tar.gz -o go1.15.5.darwin-amd64.tar.gz
-            sudo tar -C /usr/local -xzf go1.15.5.darwin-amd64.tar.gz
+            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
             ln -s /usr/local/go/bin/go /usr/local/bin/go
             HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
       - install-xtensa-toolchain:
@@ -280,39 +298,46 @@ commands:
             - go-cache-macos-v2-{{ checksum "go.mod" }}
       - restore_cache:
           keys:
-            - llvm-source-11-macos-v1
+            - llvm-source-11-macos-v2
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-11-macos-v1
+          key: llvm-source-11-macos-v2
           paths:
-            - llvm-project
+            - llvm-project/clang/lib/Headers
+            - llvm-project/clang/include
+            - llvm-project/lld/include
+            - llvm-project/llvm/include
       - restore_cache:
           keys:
-            - llvm-build-11-macos-v1
+            - llvm-build-11-macos-v3
       - 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-v1
+          key: llvm-build-11-macos-v3
           paths:
             llvm-build
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-macos-v2
+            - wasi-libc-sysroot-macos-v3
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-macos-v2
+          key: wasi-libc-sysroot-macos-v3
           paths:
             - lib/wasi-libc/sysroot
       - run:
@@ -340,18 +365,6 @@ commands:
             - /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
@@ -370,6 +383,12 @@ jobs:
     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
@@ -391,11 +410,10 @@ jobs:
 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

.gitignore

@@ -19,3 +19,10 @@ src/device/kendryte/*.s
 vendor
 llvm-build
 llvm-project
+
+# Ignore files generated by smoketest
+test.gba
+test.hex
+test.nro
+test.wasm
+wasm.wasm

BUILDING.md

@@ -23,7 +23,7 @@ different guide:
 LLVM, Clang and LLD are quite light on dependencies, requiring only standard
 build tools to be built. Go is of course necessary to build TinyGo itself.
 
-  * Go (1.11+)
+  * Go (1.13+)
   * Standard build tools (gcc/clang)
   * git
   * CMake
@@ -43,11 +43,6 @@ 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

CHANGELOG.md

@@ -1,3 +1,93 @@
+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
 ---
 

Dockerfile

@@ -1,10 +1,10 @@
-# TinyGo base stage installs the most recent Go 1.15.x, LLVM 10 and the TinyGo compiler itself.
+# 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
 
 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 && \
+    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-11 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y llvm-10-dev libclang-10-dev lld-10 git
+    apt-get install -y llvm-11-dev libclang-11-dev lld-11 git
 
 COPY . /tinygo
 
@@ -29,7 +29,7 @@ COPY --from=tinygo-base /tinygo/targets /tinygo/targets
 
 RUN cd /tinygo/ && \
     apt-get update && \
-    apt-get install -y make clang-10 libllvm10 lld-10 && \
+    apt-get install -y make clang-11 libllvm11 lld-11 && \
     make wasi-libc
 
 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
@@ -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-10 && \
+    apt-get install -y apt-utils make clang-11 && \
     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-10 binutils-avr gcc-avr avr-libc && \
+    apt-get install -y apt-utils make clang-11 binutils-avr gcc-avr avr-libc && \
     make gen-device
 
 CMD ["tinygo"]

LICENSE

@@ -1,7 +1,7 @@
-Copyright (c) 2018-2020 TinyGo Authors. All rights reserved.
+Copyright (c) 2018-2021 TinyGo Authors. All rights reserved.
 
 TinyGo includes portions of the Go standard library.
-Copyright (c) 2009-2020 The Go Authors. All rights reserved.
+Copyright (c) 2009-2021 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.

Makefile

@@ -54,46 +54,63 @@ ifeq ($(OS),Windows_NT)
     CGO_LDFLAGS += -static -static-libgcc -static-libstdc++
     CGO_LDFLAGS_EXTRA += -lversion
 
-    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/liblibclang.a
+    LIBCLANG_NAME = libclang
 
 else ifeq ($(shell uname -s),Darwin)
     MD5SUM = md5
-    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+    LIBCLANG_NAME = clang
 else ifeq ($(shell uname -s),FreeBSD)
     MD5SUM = md5
-    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+    LIBCLANG_NAME = clang
     START_GROUP = -Wl,--start-group
     END_GROUP = -Wl,--end-group
 else
-    LIBCLANG_PATH = $(abspath $(LLVM_BUILDDIR))/lib/libclang.a
+    LIBCLANG_NAME = clang
     START_GROUP = -Wl,--start-group
     END_GROUP = -Wl,--end-group
 endif
 
-CLANG_LIBS = $(START_GROUP) -lclangAnalysis -lclangARCMigrate -lclangAST -lclangASTMatchers -lclangBasic -lclangCodeGen -lclangCrossTU -lclangDriver -lclangDynamicASTMatchers -lclangEdit -lclangFormat -lclangFrontend -lclangFrontendTool -lclangHandleCXX -lclangHandleLLVM -lclangIndex -lclangLex -lclangParse -lclangRewrite -lclangRewriteFrontend -lclangSema -lclangSerialization -lclangStaticAnalyzerCheckers -lclangStaticAnalyzerCore -lclangStaticAnalyzerFrontend -lclangTooling -lclangToolingASTDiff -lclangToolingCore -lclangToolingInclusions $(END_GROUP) -lstdc++
+# 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++
 
-LLD_LIBS = $(START_GROUP) -llldCOFF -llldCommon -llldCore -llldDriver -llldELF -llldMachO -llldMinGW -llldReaderWriter -llldWasm -llldYAML $(END_GROUP)
+# 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)
 
+# 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 $(LLD_SRC))/include
     CGO_CXXFLAGS=-std=c++14
-    CGO_LDFLAGS+=$(LIBCLANG_PATH) -L$(abspath $(LLVM_BUILDDIR)/lib) $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
+    CGO_LDFLAGS+=$(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)
 endif
 
 
 clean:
 	@rm -rf build
 
-FMT_PATHS = ./*.go builder cgo compiler interp ir loader src/device/arm src/examples src/machine src/os src/reflect src/runtime src/sync src/syscall src/internal/reflectlite transform
+FMT_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:
 	@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-stm32 gen-device-kendryte gen-device-nxp
+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-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
@@ -135,18 +152,18 @@ gen-device-stm32: build/gen-device-svd
 
 
 # Get LLVM sources.
-$(LLVM_PROJECTDIR)/README.md:
+$(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)/README.md
+llvm-source: $(LLVM_PROJECTDIR)/llvm
 
 # 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_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;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)
 
 # Build LLVM.
 $(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
-	cd $(LLVM_BUILDDIR); ninja
+	cd $(LLVM_BUILDDIR); ninja $(NINJA_BUILD_TARGETS)
 
 
 # Build wasi-libc sysroot
@@ -163,7 +180,7 @@ tinygo:
 	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`" .
 
 test: wasi-libc
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./cgo ./compileopts ./compiler ./interp ./transform .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./builder ./cgo ./compileopts ./compiler ./interp ./transform .
 
 # Test known-working standard library packages.
 # TODO: do this in one command, parallelize, and only show failing tests (no
@@ -209,8 +226,6 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=microbit            examples/microbit-blink
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=microbit-v2         examples/microbit-blink
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pininterrupt
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial
@@ -239,12 +254,14 @@ smoketest:
 	@$(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
 	$(TINYGO) build -size short -o test.hex -target=reelboard           examples/blinky2
@@ -253,6 +270,10 @@ smoketest:
 	@$(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
 	$(TINYGO) build -size short -o test.hex -target=feather-m0          examples/blinky1
@@ -261,14 +282,6 @@ smoketest:
 	@$(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
-	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1      examples/blinky1
-	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=feather-stm32f405   examples/blinky1
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
@@ -277,6 +290,8 @@ smoketest:
 	@$(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
 	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/blinky1
@@ -293,12 +308,8 @@ smoketest:
 	@$(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
-	$(TINYGO) build -size short -o test.hex -target=lgt92    examples/blinky1
-	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=x9pro               examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10056-s140v7     examples/blinky1
@@ -325,10 +336,12 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=teensy36            examples/blinky1
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=nucleo-f722ze       examples/blinky1
-	@$(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
+	$(TINYGO) build -size short -o test.hex -target=feather-m4-can      examples/blinky1
+	@$(MD5SUM) test.hex
 	# test pwm
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
 	@$(MD5SUM) test.hex
@@ -336,8 +349,30 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/pwm
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/pwm
+ifneq ($(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
@@ -347,6 +382,10 @@ ifneq ($(AVR), 0)
 	@$(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
 	$(TINYGO) build -size short -o test.hex -target=digispark           examples/blinky1
@@ -375,6 +414,9 @@ endif
 	@$(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

README.md

@@ -43,34 +43,43 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-The following 44 microcontroller boards are currently supported:
+The following 57 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 Alpha](https://www.adafruit.com/product/4500)
+* [Adafruit CLUE](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 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 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)
@@ -81,11 +90,15 @@ The following 44 microcontroller boards are currently supported:
 * [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" 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" 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 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/)

azure-pipelines.yml

@@ -12,7 +12,7 @@ jobs:
   steps:
     - task: GoTool@0
       inputs:
-        version: '1.15'
+        version: '1.16'
     - checkout: self
       fetchDepth: 1
     - task: Cache@2
@@ -24,15 +24,11 @@ jobs:
       displayName: Download LLVM source
       inputs:
         targetType: inline
-        script: |
-          make llvm-source
-          # Workaround for bad symlinks:
-          # https://github.com/microsoft/azure-pipelines-tasks/issues/13418
-          rm -f llvm-project/libcxx/test/std/input.output/filesystems/Inputs/static_test_env/bad_symlink
+        script: make llvm-source
     - task: CacheBeta@0
       displayName: Cache LLVM build
       inputs:
-        key: llvm-build-11-windows-v3
+        key: llvm-build-11-windows-v4
         path: llvm-build
     - task: Bash@3
       displayName: Build LLVM
@@ -56,7 +52,7 @@ jobs:
     - task: CacheBeta@0
       displayName: Cache wasi-libc sysroot
       inputs:
-        key: wasi-libc-sysroot-v3
+        key: wasi-libc-sysroot-v4
         path: lib/wasi-libc/sysroot
     - task: Bash@3
       displayName: Build wasi-libc

builder/build.go

@@ -4,16 +4,19 @@
 package builder
 
 import (
+	"crypto/sha512"
 	"debug/elf"
 	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"go/types"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
 	"sort"
-	"strconv"
 	"strings"
 
 	"github.com/tinygo-org/tinygo/compileopts"
@@ -38,6 +41,30 @@ type BuildResult struct {
 	MainDir string
 }
 
+// packageAction is the struct that is serialized to JSON and hashed, to work as
+// a cache key of compiled packages. It should contain all the information that
+// goes into a compiled package to avoid using stale data.
+//
+// Right now it's still important to include a hash of every import, because a
+// dependency might have a public constant that this package uses and thus this
+// package will need to be recompiled if that constant changes. In the future,
+// the type data should be serialized to disk which can then be used as cache
+// key, avoiding the need for recompiling all dependencies when only the
+// implementation of an imported package changes.
+type packageAction struct {
+	ImportPath       string
+	CompilerVersion  int // compiler.Version
+	InterpVersion    int // interp.Version
+	LLVMVersion      string
+	Config           *compiler.Config
+	CFlags           []string
+	FileHashes       map[string]string // hash of every file that's part of the package
+	Imports          map[string]string // map from imported package to action ID hash
+	OptLevel         int               // LLVM optimization level (0-3)
+	SizeLevel        int               // LLVM optimization for size level (0-2)
+	UndefinedGlobals []string          // globals that are left as external globals (no initializer)
+}
+
 // Build performs a single package to executable Go build. It takes in a package
 // name, an output path, and set of compile options and from that it manages the
 // whole compilation process.
@@ -45,10 +72,34 @@ type BuildResult struct {
 // The error value may be of type *MultiError. Callers will likely want to check
 // for this case and print such errors individually.
 func Build(pkgName, outpath string, config *compileopts.Config, action func(BuildResult) error) error {
+	// Create a temporary directory for intermediary files.
+	dir, err := ioutil.TempDir("", "tinygo")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(dir)
+
+	compilerConfig := &compiler.Config{
+		Triple:          config.Triple(),
+		CPU:             config.CPU(),
+		Features:        config.Features(),
+		GOOS:            config.GOOS(),
+		GOARCH:          config.GOARCH(),
+		CodeModel:       config.CodeModel(),
+		RelocationModel: config.RelocationModel(),
+
+		Scheduler:          config.Scheduler(),
+		FuncImplementation: config.FuncImplementation(),
+		AutomaticStackSize: config.AutomaticStackSize(),
+		DefaultStackSize:   config.Target.DefaultStackSize,
+		NeedsStackObjects:  config.NeedsStackObjects(),
+		Debug:              config.Debug(),
+	}
+
 	// Load the target machine, which is the LLVM object that contains all
 	// details of a target (alignment restrictions, pointer size, default
 	// address spaces, etc).
-	machine, err := compiler.NewTargetMachine(config)
+	machine, err := compiler.NewTargetMachine(compilerConfig)
 	if err != nil {
 		return err
 	}
@@ -65,32 +116,569 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 		return err
 	}
 
-	// Compile AST to IR.
-	mod, errs := compiler.CompileProgram(pkgName, lprogram, machine, config)
-	if errs != nil {
-		return newMultiError(errs)
+	// The slice of jobs that orchestrates most of the build.
+	// This is somewhat like an in-memory Makefile with each job being a
+	// Makefile target.
+	var jobs []*compileJob
+
+	// Create the *ssa.Program. This does not yet build the entire SSA of the
+	// program so it's pretty fast and doesn't need to be parallelized.
+	program := lprogram.LoadSSA()
+
+	// Add jobs to compile each package.
+	// Packages that have a cache hit will not be compiled again.
+	var packageJobs []*compileJob
+	packageBitcodePaths := make(map[string]string)
+	packageActionIDs := make(map[string]string)
+	optLevel, sizeLevel, _ := config.OptLevels()
+	for _, pkg := range lprogram.Sorted() {
+		pkg := pkg // necessary to avoid a race condition
+
+		var undefinedGlobals []string
+		for name := range config.Options.GlobalValues[pkg.Pkg.Path()] {
+			undefinedGlobals = append(undefinedGlobals, name)
+		}
+		sort.Strings(undefinedGlobals)
+
+		// Create a cache key: a hash from the action ID below that contains all
+		// the parameters for the build.
+		actionID := packageAction{
+			ImportPath:       pkg.ImportPath,
+			CompilerVersion:  compiler.Version,
+			InterpVersion:    interp.Version,
+			LLVMVersion:      llvm.Version,
+			Config:           compilerConfig,
+			CFlags:           pkg.CFlags,
+			FileHashes:       make(map[string]string, len(pkg.FileHashes)),
+			Imports:          make(map[string]string, len(pkg.Pkg.Imports())),
+			OptLevel:         optLevel,
+			SizeLevel:        sizeLevel,
+			UndefinedGlobals: undefinedGlobals,
+		}
+		for filePath, hash := range pkg.FileHashes {
+			actionID.FileHashes[filePath] = hex.EncodeToString(hash)
+		}
+		for _, imported := range pkg.Pkg.Imports() {
+			hash, ok := packageActionIDs[imported.Path()]
+			if !ok {
+				return fmt.Errorf("package %s imports %s but couldn't find dependency", pkg.ImportPath, imported.Path())
+			}
+			actionID.Imports[imported.Path()] = hash
+		}
+		buf, err := json.Marshal(actionID)
+		if err != nil {
+			panic(err) // shouldn't happen
+		}
+		hash := sha512.Sum512_224(buf)
+		packageActionIDs[pkg.ImportPath] = hex.EncodeToString(hash[:])
+
+		// Determine the path of the bitcode file (which is a serialized version
+		// of a LLVM module).
+		cacheDir := goenv.Get("GOCACHE")
+		if cacheDir == "off" {
+			// Use temporary build directory instead, effectively disabling the
+			// build cache.
+			cacheDir = dir
+		}
+		bitcodePath := filepath.Join(cacheDir, "pkg-"+hex.EncodeToString(hash[:])+".bc")
+		packageBitcodePaths[pkg.ImportPath] = bitcodePath
+
+		// Check whether this package has been compiled before, and if so don't
+		// compile it again.
+		if _, err := os.Stat(bitcodePath); err == nil {
+			// Already cached, don't recreate this package.
+			continue
+		}
+
+		// The package has not yet been compiled, so create a job to do so.
+		job := &compileJob{
+			description: "compile package " + pkg.ImportPath,
+			run: func(*compileJob) error {
+				// Compile AST to IR. The compiler.CompilePackage function will
+				// build the SSA as needed.
+				mod, errs := compiler.CompilePackage(pkg.ImportPath, pkg, program.Package(pkg.Pkg), machine, compilerConfig, config.DumpSSA())
+				if errs != nil {
+					return newMultiError(errs)
+				}
+				if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+					return errors.New("verification error after compiling package " + pkg.ImportPath)
+				}
+
+				// Erase all globals that are part of the undefinedGlobals list.
+				// This list comes from the -ldflags="-X pkg.foo=val" option.
+				// Instead of setting the value directly in the AST (which would
+				// mean the value, which may be a secret, is stored in the build
+				// cache), the global itself is left external (undefined) and is
+				// only set at the end of the compilation.
+				for _, name := range undefinedGlobals {
+					globalName := pkg.Pkg.Path() + "." + name
+					global := mod.NamedGlobal(globalName)
+					if global.IsNil() {
+						return errors.New("global not found: " + globalName)
+					}
+					name := global.Name()
+					newGlobal := llvm.AddGlobal(mod, global.Type().ElementType(), name+".tmp")
+					global.ReplaceAllUsesWith(newGlobal)
+					global.EraseFromParentAsGlobal()
+					newGlobal.SetName(name)
+				}
+
+				// Try to interpret package initializers at compile time.
+				// It may only be possible to do this partially, in which case
+				// it is completed after all IR files are linked.
+				pkgInit := mod.NamedFunction(pkg.Pkg.Path() + ".init")
+				if pkgInit.IsNil() {
+					panic("init not found for " + pkg.Pkg.Path())
+				}
+				err := interp.RunFunc(pkgInit, config.DumpSSA())
+				if err != nil {
+					return err
+				}
+				if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+					return errors.New("verification error after interpreting " + pkgInit.Name())
+				}
+
+				if sizeLevel >= 2 {
+					// Set the "optsize" attribute to make slightly smaller
+					// binaries at the cost of some performance.
+					kind := llvm.AttributeKindID("optsize")
+					attr := mod.Context().CreateEnumAttribute(kind, 0)
+					for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+						fn.AddFunctionAttr(attr)
+					}
+				}
+
+				// Run function passes for each function in the module.
+				// These passes are intended to be run on each function right
+				// after they're created to reduce IR size (and maybe also for
+				// cache locality to improve performance), but for now they're
+				// run here for each function in turn. Maybe this can be
+				// improved in the future.
+				builder := llvm.NewPassManagerBuilder()
+				defer builder.Dispose()
+				builder.SetOptLevel(optLevel)
+				builder.SetSizeLevel(sizeLevel)
+				funcPasses := llvm.NewFunctionPassManagerForModule(mod)
+				defer funcPasses.Dispose()
+				builder.PopulateFunc(funcPasses)
+				funcPasses.InitializeFunc()
+				for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+					if fn.IsDeclaration() {
+						continue
+					}
+					funcPasses.RunFunc(fn)
+				}
+				funcPasses.FinalizeFunc()
+
+				// Serialize the LLVM module as a bitcode file.
+				// Write to a temporary path that is renamed to the destination
+				// file to avoid race conditions with other TinyGo invocatiosn
+				// that might also be compiling this package at the same time.
+				f, err := ioutil.TempFile(filepath.Dir(bitcodePath), filepath.Base(bitcodePath))
+				if err != nil {
+					return err
+				}
+				if runtime.GOOS == "windows" {
+					// Work around a problem on Windows.
+					// For some reason, WriteBitcodeToFile causes TinyGo to
+					// exit with the following message:
+					//   LLVM ERROR: IO failure on output stream: Bad file descriptor
+					buf := llvm.WriteBitcodeToMemoryBuffer(mod)
+					defer buf.Dispose()
+					_, err = f.Write(buf.Bytes())
+				} else {
+					// Otherwise, write bitcode directly to the file (probably
+					// faster).
+					err = llvm.WriteBitcodeToFile(mod, f)
+				}
+				if err != nil {
+					// WriteBitcodeToFile doesn't produce a useful error on its
+					// own, so create a somewhat useful error message here.
+					return fmt.Errorf("failed to write bitcode for package %s to file %s", pkg.ImportPath, bitcodePath)
+				}
+				err = f.Close()
+				if err != nil {
+					return err
+				}
+
+				// Rename may fail if another process is trying to write to
+				// the same file.  However, in this case, the failure is
+				// acceptable because the result of the other process can be
+				// used.
+				os.Rename(f.Name(), bitcodePath)
+				return nil
+			},
+		}
+		jobs = append(jobs, job)
+		packageJobs = append(packageJobs, job)
 	}
 
-	if config.Options.PrintIR {
-		fmt.Println("; Generated LLVM IR:")
-		fmt.Println(mod.String())
+	// Add job that links and optimizes all packages together.
+	var mod llvm.Module
+	var stackSizeLoads []string
+	programJob := &compileJob{
+		description:  "link+optimize packages (LTO)",
+		dependencies: packageJobs,
+		run: func(*compileJob) error {
+			// Load and link all the bitcode files. This does not yet optimize
+			// anything, it only links the bitcode files together.
+			ctx := llvm.NewContext()
+			mod = ctx.NewModule("")
+			for _, pkg := range lprogram.Sorted() {
+				pkgMod, err := ctx.ParseBitcodeFile(packageBitcodePaths[pkg.ImportPath])
+				if err != nil {
+					return fmt.Errorf("failed to load bitcode file: %w", err)
+				}
+				err = llvm.LinkModules(mod, pkgMod)
+				if err != nil {
+					return fmt.Errorf("failed to link module: %w", err)
+				}
+			}
+
+			// Create runtime.initAll function that calls the runtime
+			// initializer of each package.
+			llvmInitFn := mod.NamedFunction("runtime.initAll")
+			llvmInitFn.SetLinkage(llvm.InternalLinkage)
+			llvmInitFn.SetUnnamedAddr(true)
+			llvmInitFn.Param(0).SetName("context")
+			llvmInitFn.Param(1).SetName("parentHandle")
+			block := mod.Context().AddBasicBlock(llvmInitFn, "entry")
+			irbuilder := mod.Context().NewBuilder()
+			defer irbuilder.Dispose()
+			irbuilder.SetInsertPointAtEnd(block)
+			i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
+			for _, pkg := range lprogram.Sorted() {
+				pkgInit := mod.NamedFunction(pkg.Pkg.Path() + ".init")
+				if pkgInit.IsNil() {
+					panic("init not found for " + pkg.Pkg.Path())
+				}
+				irbuilder.CreateCall(pkgInit, []llvm.Value{llvm.Undef(i8ptrType), llvm.Undef(i8ptrType)}, "")
+			}
+			irbuilder.CreateRetVoid()
+
+			// After linking, functions should (as far as possible) be set to
+			// private linkage or internal linkage. The compiler package marks
+			// non-exported functions by setting the visibility to hidden or
+			// (for thunks) to linkonce_odr linkage. Change the linkage here to
+			// internal to benefit much more from interprocedural optimizations.
+			for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+				if fn.Visibility() == llvm.HiddenVisibility {
+					fn.SetVisibility(llvm.DefaultVisibility)
+					fn.SetLinkage(llvm.InternalLinkage)
+				} else if fn.Linkage() == llvm.LinkOnceODRLinkage {
+					fn.SetLinkage(llvm.InternalLinkage)
+				}
+			}
+
+			// Do the same for globals.
+			for global := mod.FirstGlobal(); !global.IsNil(); global = llvm.NextGlobal(global) {
+				if global.Visibility() == llvm.HiddenVisibility {
+					global.SetVisibility(llvm.DefaultVisibility)
+					global.SetLinkage(llvm.InternalLinkage)
+				} else if global.Linkage() == llvm.LinkOnceODRLinkage {
+					global.SetLinkage(llvm.InternalLinkage)
+				}
+			}
+
+			if config.Options.PrintIR {
+				fmt.Println("; Generated LLVM IR:")
+				fmt.Println(mod.String())
+			}
+
+			// Run all optimization passes, which are much more effective now
+			// that the optimizer can see the whole program at once.
+			err := optimizeProgram(mod, config)
+			if err != nil {
+				return err
+			}
+
+			// Make sure stack sizes are loaded from a separate section so they can be
+			// modified after linking.
+			if config.AutomaticStackSize() {
+				stackSizeLoads = transform.CreateStackSizeLoads(mod, config)
+			}
+			return nil
+		},
 	}
-	if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
-		return errors.New("verification error after IR construction")
+	jobs = append(jobs, programJob)
+
+	// Check whether we only need to create an object file.
+	// If so, we don't need to link anything and will be finished quickly.
+	outext := filepath.Ext(outpath)
+	if outext == ".o" || outext == ".bc" || outext == ".ll" {
+		// Run jobs to produce the LLVM module.
+		err := runJobs(jobs)
+		if err != nil {
+			return err
+		}
+		// Generate output.
+		switch outext {
+		case ".o":
+			llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
+			if err != nil {
+				return err
+			}
+			return ioutil.WriteFile(outpath, llvmBuf.Bytes(), 0666)
+		case ".bc":
+			data := llvm.WriteBitcodeToMemoryBuffer(mod).Bytes()
+			return ioutil.WriteFile(outpath, data, 0666)
+		case ".ll":
+			data := []byte(mod.String())
+			return ioutil.WriteFile(outpath, data, 0666)
+		default:
+			panic("unreachable")
+		}
 	}
 
-	err = interp.Run(mod, config.DumpSSA())
+	// Act as a compiler driver, as we need to produce a complete executable.
+	// First add all jobs necessary to build this object file, then afterwards
+	// run all jobs in parallel as far as possible.
+
+	// Add job to write the output object file.
+	objfile := filepath.Join(dir, "main.o")
+	outputObjectFileJob := &compileJob{
+		description:  "generate output file",
+		dependencies: []*compileJob{programJob},
+		result:       objfile,
+		run: func(*compileJob) error {
+			llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
+			if err != nil {
+				return err
+			}
+			return ioutil.WriteFile(objfile, llvmBuf.Bytes(), 0666)
+		},
+	}
+	jobs = append(jobs, outputObjectFileJob)
+
+	// Prepare link command.
+	linkerDependencies := []*compileJob{outputObjectFileJob}
+	executable := filepath.Join(dir, "main")
+	tmppath := executable // final file
+	ldflags := append(config.LDFlags(), "-o", executable)
+
+	// Add compiler-rt dependency if needed. Usually this is a simple load from
+	// a cache.
+	if config.Target.RTLib == "compiler-rt" {
+		job, err := CompilerRT.load(config.Triple(), config.CPU(), dir)
+		if err != nil {
+			return err
+		}
+		jobs = append(jobs, job.dependencies...)
+		jobs = append(jobs, job)
+		linkerDependencies = append(linkerDependencies, job)
+	}
+
+	// Add libc dependency if needed.
+	root := goenv.Get("TINYGOROOT")
+	switch config.Target.Libc {
+	case "picolibc":
+		job, err := Picolibc.load(config.Triple(), config.CPU(), dir)
+		if err != nil {
+			return err
+		}
+		// The library needs to be compiled (cache miss).
+		jobs = append(jobs, job.dependencies...)
+		jobs = append(jobs, job)
+		linkerDependencies = append(linkerDependencies, job)
+	case "wasi-libc":
+		path := filepath.Join(root, "lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a")
+		if _, err := os.Stat(path); os.IsNotExist(err) {
+			return errors.New("could not find wasi-libc, perhaps you need to run `make wasi-libc`?")
+		}
+		ldflags = append(ldflags, path)
+	case "":
+		// no library specified, so nothing to do
+	default:
+		return fmt.Errorf("unknown libc: %s", config.Target.Libc)
+	}
+
+	// Add jobs to compile extra files. These files are in C or assembly and
+	// contain things like the interrupt vector table and low level operations
+	// such as stack switching.
+	for _, path := range config.ExtraFiles() {
+		abspath := filepath.Join(root, path)
+		job := &compileJob{
+			description: "compile extra file " + path,
+			run: func(job *compileJob) error {
+				result, err := compileAndCacheCFile(abspath, dir, config.CFlags(), config.Options.PrintCommands)
+				job.result = result
+				return err
+			},
+		}
+		jobs = append(jobs, job)
+		linkerDependencies = append(linkerDependencies, job)
+	}
+
+	// Add jobs to compile C files in all packages. This is part of CGo.
+	// TODO: do this as part of building the package to be able to link the
+	// bitcode files together.
+	for _, pkg := range lprogram.Sorted() {
+		pkg := pkg
+		for _, filename := range pkg.CFiles {
+			abspath := filepath.Join(pkg.Dir, filename)
+			job := &compileJob{
+				description: "compile CGo file " + abspath,
+				run: func(job *compileJob) error {
+					result, err := compileAndCacheCFile(abspath, dir, pkg.CFlags, config.Options.PrintCommands)
+					job.result = result
+					return err
+				},
+			}
+			jobs = append(jobs, job)
+			linkerDependencies = append(linkerDependencies, job)
+		}
+	}
+
+	// Linker flags from CGo lines:
+	//     #cgo LDFLAGS: foo
+	if len(lprogram.LDFlags) > 0 {
+		ldflags = append(ldflags, lprogram.LDFlags...)
+	}
+
+	// Create a linker job, which links all object files together and does some
+	// extra stuff that can only be done after linking.
+	jobs = append(jobs, &compileJob{
+		description:  "link",
+		dependencies: linkerDependencies,
+		run: func(job *compileJob) error {
+			for _, dependency := range job.dependencies {
+				if dependency.result == "" {
+					return errors.New("dependency without result: " + dependency.description)
+				}
+				ldflags = append(ldflags, dependency.result)
+			}
+			if config.Options.PrintCommands {
+				fmt.Printf("%s %s\n", config.Target.Linker, strings.Join(ldflags, " "))
+			}
+			err = link(config.Target.Linker, ldflags...)
+			if err != nil {
+				return &commandError{"failed to link", executable, err}
+			}
+
+			var calculatedStacks []string
+			var stackSizes map[string]functionStackSize
+			if config.Options.PrintStacks || config.AutomaticStackSize() {
+				// Try to determine stack sizes at compile time.
+				// Don't do this by default as it usually doesn't work on
+				// unsupported architectures.
+				calculatedStacks, stackSizes, err = determineStackSizes(mod, executable)
+				if err != nil {
+					return err
+				}
+			}
+			if config.AutomaticStackSize() {
+				// Modify the .tinygo_stacksizes section that contains a stack size
+				// for each goroutine.
+				err = modifyStackSizes(executable, stackSizeLoads, stackSizes)
+				if err != nil {
+					return fmt.Errorf("could not modify stack sizes: %w", err)
+				}
+			}
+
+			if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
+				sizes, err := loadProgramSize(executable)
+				if err != nil {
+					return err
+				}
+				if config.Options.PrintSizes == "short" {
+					fmt.Printf("   code    data     bss |   flash     ram\n")
+					fmt.Printf("%7d %7d %7d | %7d %7d\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+				} else {
+					fmt.Printf("   code  rodata    data     bss |   flash     ram | package\n")
+					for _, name := range sizes.sortedPackageNames() {
+						pkgSize := sizes.Packages[name]
+						fmt.Printf("%7d %7d %7d %7d | %7d %7d | %s\n", pkgSize.Code, pkgSize.ROData, pkgSize.Data, pkgSize.BSS, pkgSize.Flash(), pkgSize.RAM(), name)
+					}
+					fmt.Printf("%7d %7d %7d %7d | %7d %7d | (sum)\n", sizes.Sum.Code, sizes.Sum.ROData, sizes.Sum.Data, sizes.Sum.BSS, sizes.Sum.Flash(), sizes.Sum.RAM())
+					fmt.Printf("%7d       - %7d %7d | %7d %7d | (all)\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
+				}
+			}
+
+			// Print goroutine stack sizes, as far as possible.
+			if config.Options.PrintStacks {
+				printStacks(calculatedStacks, stackSizes)
+			}
+
+			return nil
+		},
+	})
+
+	// Run all jobs to compile and link the program.
+	// Do this now (instead of after elf-to-hex and similar conversions) as it
+	// is simpler and cannot be parallelized.
+	err = runJobs(jobs)
 	if err != nil {
 		return err
 	}
-	if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
-		return errors.New("verification error after interpreting runtime.initAll")
+
+	// Get an Intel .hex file or .bin file from the .elf file.
+	outputBinaryFormat := config.BinaryFormat(outext)
+	switch outputBinaryFormat {
+	case "elf":
+		// do nothing, file is already in ELF format
+	case "hex", "bin":
+		// Extract raw binary, either encoding it as a hex file or as a raw
+		// firmware file.
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := objcopy(executable, tmppath, outputBinaryFormat)
+		if err != nil {
+			return err
+		}
+	case "uf2":
+		// Get UF2 from the .elf file.
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
+		if err != nil {
+			return err
+		}
+	case "esp32", "esp8266":
+		// Special format for the ESP family of chips (parsed by the ROM
+		// bootloader).
+		tmppath = filepath.Join(dir, "main"+outext)
+		err := makeESPFirmareImage(executable, tmppath, outputBinaryFormat)
+		if err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("unknown output binary format: %s", outputBinaryFormat)
+	}
+	return action(BuildResult{
+		Binary:  tmppath,
+		MainDir: lprogram.MainPkg().Dir,
+	})
+}
+
+// optimizeProgram runs a series of optimizations and transformations that are
+// needed to convert a program to its final form. Some transformations are not
+// optional and must be run as the compiler expects them to run.
+func optimizeProgram(mod llvm.Module, config *compileopts.Config) error {
+	err := interp.Run(mod, config.DumpSSA())
+	if err != nil {
+		return err
+	}
+	if config.VerifyIR() {
+		// Only verify if we really need it.
+		// The IR has already been verified before writing the bitcode to disk
+		// and the interp function above doesn't need to do a lot as most of the
+		// package initializers have already run. Additionally, verifying this
+		// linked IR is _expensive_ because dead code hasn't been removed yet,
+		// easily costing a few hundred milliseconds. Therefore, only do it when
+		// specifically requested.
+		if err := llvm.VerifyModule(mod, llvm.PrintMessageAction); err != nil {
+			return errors.New("verification error after interpreting runtime.initAll")
+		}
 	}
 
 	if config.GOOS() != "darwin" {
 		transform.ApplyFunctionSections(mod) // -ffunction-sections
 	}
 
+	// Insert values from -ldflags="-X ..." into the IR.
+	err = setGlobalValues(mod, config.Options.GlobalValues)
+	if err != nil {
+		return err
+	}
+
 	// Browsers cannot handle external functions that have type i64 because it
 	// cannot be represented exactly in JavaScript (JS only has doubles). To
 	// keep functions interoperable, pass int64 types as pointers to
@@ -105,28 +693,8 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 
 	// Optimization levels here are roughly the same as Clang, but probably not
 	// exactly.
-	errs = nil
-	switch config.Options.Opt {
-	/*
-		Currently, turning optimizations off causes compile failures.
-		We rely on the optimizer removing some dead symbols.
-		Avoid providing an option that does not work right now.
-		In the future once everything has been fixed we can re-enable this.
-
-		case "none", "0":
-			errs = transform.Optimize(mod, config, 0, 0, 0) // -O0
-	*/
-	case "1":
-		errs = transform.Optimize(mod, config, 1, 0, 0) // -O1
-	case "2":
-		errs = transform.Optimize(mod, config, 2, 0, 225) // -O2
-	case "s":
-		errs = transform.Optimize(mod, config, 2, 1, 225) // -Os
-	case "z":
-		errs = transform.Optimize(mod, config, 2, 2, 5) // -Oz, default
-	default:
-		errs = []error{errors.New("unknown optimization level: -opt=" + config.Options.Opt)}
-	}
+	optLevel, sizeLevel, inlinerThreshold := config.OptLevels()
+	errs := transform.Optimize(mod, config, optLevel, sizeLevel, inlinerThreshold)
 	if len(errs) > 0 {
 		return newMultiError(errs)
 	}
@@ -145,189 +713,72 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 		transform.DisableTailCalls(mod)
 	}
 
-	// Make sure stack sizes are loaded from a separate section so they can be
-	// modified after linking.
-	var stackSizeLoads []string
-	if config.AutomaticStackSize() {
-		stackSizeLoads = transform.CreateStackSizeLoads(mod, config)
+	return nil
+}
+
+// setGlobalValues sets the global values from the -ldflags="-X ..." compiler
+// option in the given module. An error may be returned if the global is not of
+// the expected type.
+func setGlobalValues(mod llvm.Module, globals map[string]map[string]string) error {
+	var pkgPaths []string
+	for pkgPath := range globals {
+		pkgPaths = append(pkgPaths, pkgPath)
 	}
-
-	// Generate output.
-	outext := filepath.Ext(outpath)
-	switch outext {
-	case ".o":
-		llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
-		if err != nil {
-			return err
+	sort.Strings(pkgPaths)
+	for _, pkgPath := range pkgPaths {
+		pkg := globals[pkgPath]
+		var names []string
+		for name := range pkg {
+			names = append(names, name)
 		}
-		return ioutil.WriteFile(outpath, llvmBuf.Bytes(), 0666)
-	case ".bc":
-		data := llvm.WriteBitcodeToMemoryBuffer(mod).Bytes()
-		return ioutil.WriteFile(outpath, data, 0666)
-	case ".ll":
-		data := []byte(mod.String())
-		return ioutil.WriteFile(outpath, data, 0666)
-	default:
-		// Act as a compiler driver.
-
-		// Create a temporary directory for intermediary files.
-		dir, err := ioutil.TempDir("", "tinygo")
-		if err != nil {
-			return err
-		}
-		defer os.RemoveAll(dir)
-
-		// Write the object file.
-		objfile := filepath.Join(dir, "main.o")
-		llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
-		if err != nil {
-			return err
-		}
-		err = ioutil.WriteFile(objfile, llvmBuf.Bytes(), 0666)
-		if err != nil {
-			return err
-		}
-
-		// Prepare link command.
-		executable := filepath.Join(dir, "main")
-		tmppath := executable // final file
-		ldflags := append(config.LDFlags(), "-o", executable, objfile)
-
-		// Load builtins library from the cache, possibly compiling it on the
-		// fly.
-		if config.Target.RTLib == "compiler-rt" {
-			librt, err := CompilerRT.Load(config.Triple())
-			if err != nil {
-				return err
+		sort.Strings(names)
+		for _, name := range names {
+			value := pkg[name]
+			globalName := pkgPath + "." + name
+			global := mod.NamedGlobal(globalName)
+			if global.IsNil() || !global.Initializer().IsNil() {
+				// The global either does not exist (optimized away?) or has
+				// some value, in which case it has already been initialized at
+				// package init time.
+				continue
 			}
-			ldflags = append(ldflags, librt)
-		}
 
-		// Add libc.
-		if config.Target.Libc == "picolibc" {
-			libc, err := Picolibc.Load(config.Triple())
-			if err != nil {
-				return err
+			// A strin is a {ptr, len} pair. We need these types to build the
+			// initializer.
+			initializerType := global.Type().ElementType()
+			if initializerType.TypeKind() != llvm.StructTypeKind || initializerType.StructName() == "" {
+				return fmt.Errorf("%s: not a string", globalName)
+			}
+			elementTypes := initializerType.StructElementTypes()
+			if len(elementTypes) != 2 {
+				return fmt.Errorf("%s: not a string", globalName)
 			}
-			ldflags = append(ldflags, libc)
-		}
 
-		// Compile extra files.
-		root := goenv.Get("TINYGOROOT")
-		for i, path := range config.ExtraFiles() {
-			abspath := filepath.Join(root, path)
-			outpath := filepath.Join(dir, "extra-"+strconv.Itoa(i)+"-"+filepath.Base(path)+".o")
-			err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, abspath)...)
-			if err != nil {
-				return &commandError{"failed to build", path, err}
-			}
-			ldflags = append(ldflags, outpath)
-		}
+			// Create a buffer for the string contents.
+			bufInitializer := mod.Context().ConstString(value, false)
+			buf := llvm.AddGlobal(mod, bufInitializer.Type(), ".string")
+			buf.SetInitializer(bufInitializer)
+			buf.SetAlignment(1)
+			buf.SetUnnamedAddr(true)
+			buf.SetLinkage(llvm.PrivateLinkage)
 
-		// Compile C files in packages.
-		// Gather the list of (C) file paths that should be included in the build.
-		for i, pkg := range lprogram.Sorted() {
-			for j, filename := range pkg.CFiles {
-				file := filepath.Join(pkg.Dir, filename)
-				outpath := filepath.Join(dir, "pkg"+strconv.Itoa(i)+"."+strconv.Itoa(j)+"-"+filepath.Base(file)+".o")
-				err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, file)...)
-				if err != nil {
-					return &commandError{"failed to build", file, err}
-				}
-				ldflags = append(ldflags, outpath)
+			// Create the string value, which is a {ptr, len} pair.
+			zero := llvm.ConstInt(mod.Context().Int32Type(), 0, false)
+			ptr := llvm.ConstGEP(buf, []llvm.Value{zero, zero})
+			if ptr.Type() != elementTypes[0] {
+				return fmt.Errorf("%s: not a string", globalName)
 			}
-		}
+			length := llvm.ConstInt(elementTypes[1], uint64(len(value)), false)
+			initializer := llvm.ConstNamedStruct(initializerType, []llvm.Value{
+				ptr,
+				length,
+			})
 
-		if len(lprogram.LDFlags) > 0 {
-			ldflags = append(ldflags, lprogram.LDFlags...)
+			// Set the initializer. No initializer should be set at this point.
+			global.SetInitializer(initializer)
 		}
-
-		// Link the object files together.
-		err = link(config.Target.Linker, ldflags...)
-		if err != nil {
-			return &commandError{"failed to link", executable, err}
-		}
-
-		var calculatedStacks []string
-		var stackSizes map[string]functionStackSize
-		if config.Options.PrintStacks || config.AutomaticStackSize() {
-			// Try to determine stack sizes at compile time.
-			// Don't do this by default as it usually doesn't work on
-			// unsupported architectures.
-			calculatedStacks, stackSizes, err = determineStackSizes(mod, executable)
-			if err != nil {
-				return err
-			}
-		}
-		if config.AutomaticStackSize() {
-			// Modify the .tinygo_stacksizes section that contains a stack size
-			// for each goroutine.
-			err = modifyStackSizes(executable, stackSizeLoads, stackSizes)
-			if err != nil {
-				return fmt.Errorf("could not modify stack sizes: %w", err)
-			}
-		}
-
-		if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
-			sizes, err := loadProgramSize(executable)
-			if err != nil {
-				return err
-			}
-			if config.Options.PrintSizes == "short" {
-				fmt.Printf("   code    data     bss |   flash     ram\n")
-				fmt.Printf("%7d %7d %7d | %7d %7d\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
-			} else {
-				fmt.Printf("   code  rodata    data     bss |   flash     ram | package\n")
-				for _, name := range sizes.sortedPackageNames() {
-					pkgSize := sizes.Packages[name]
-					fmt.Printf("%7d %7d %7d %7d | %7d %7d | %s\n", pkgSize.Code, pkgSize.ROData, pkgSize.Data, pkgSize.BSS, pkgSize.Flash(), pkgSize.RAM(), name)
-				}
-				fmt.Printf("%7d %7d %7d %7d | %7d %7d | (sum)\n", sizes.Sum.Code, sizes.Sum.ROData, sizes.Sum.Data, sizes.Sum.BSS, sizes.Sum.Flash(), sizes.Sum.RAM())
-				fmt.Printf("%7d       - %7d %7d | %7d %7d | (all)\n", sizes.Code, sizes.Data, sizes.BSS, sizes.Code+sizes.Data, sizes.Data+sizes.BSS)
-			}
-		}
-
-		// Print goroutine stack sizes, as far as possible.
-		if config.Options.PrintStacks {
-			printStacks(calculatedStacks, stackSizes)
-		}
-
-		// Get an Intel .hex file or .bin file from the .elf file.
-		outputBinaryFormat := config.BinaryFormat(outext)
-		switch outputBinaryFormat {
-		case "elf":
-			// do nothing, file is already in ELF format
-		case "hex", "bin":
-			// Extract raw binary, either encoding it as a hex file or as a raw
-			// firmware file.
-			tmppath = filepath.Join(dir, "main"+outext)
-			err := objcopy(executable, tmppath, outputBinaryFormat)
-			if err != nil {
-				return err
-			}
-		case "uf2":
-			// Get UF2 from the .elf file.
-			tmppath = filepath.Join(dir, "main"+outext)
-			err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
-			if err != nil {
-				return err
-			}
-		case "esp32", "esp8266":
-			// Special format for the ESP family of chips (parsed by the ROM
-			// bootloader).
-			tmppath = filepath.Join(dir, "main"+outext)
-			err := makeESPFirmareImage(executable, tmppath, outputBinaryFormat)
-			if err != nil {
-				return err
-			}
-		default:
-			return fmt.Errorf("unknown output binary format: %s", outputBinaryFormat)
-		}
-		return action(BuildResult{
-			Binary:  tmppath,
-			MainDir: lprogram.MainPkg().Dir,
-		})
 	}
+	return nil
 }
 
 // functionStackSizes keeps stack size information about a single function

builder/buildcache.go

@@ -30,10 +30,7 @@ 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.
-//
-// 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) {
+func cacheLoad(name string, sourceFiles []string) (string, error) {
 	cachepath := filepath.Join(goenv.Get("GOCACHE"), name)
 	cacheStat, err := os.Stat(cachepath)
 	if os.IsNotExist(err) {
@@ -58,9 +55,7 @@ func cacheLoad(name, configKey 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.
-//
-// Note: the configKey is ignored, see cacheLoad.
-func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string, error) {
+func cacheStore(tmppath, name string, sourceFiles []string) (string, error) {
 	// get the last modified time
 	if len(sourceFiles) == 0 {
 		panic("cache: no source files")
@@ -74,24 +69,16 @@ func cacheStore(tmppath, name, configKey string, sourceFiles []string) (string,
 		return "", err
 	}
 	cachepath := filepath.Join(dir, name)
-	err = moveFile(tmppath, cachepath)
+	err = copyFile(tmppath, cachepath)
 	if err != nil {
 		return "", err
 	}
 	return cachepath, nil
 }
 
-// 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.
+// 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 {
 	inf, err := os.Open(src)
 	if err != nil {
 		return err

builder/cc.go

@@ -0,0 +1,309 @@
+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
+}

builder/cc_test.go

@@ -0,0 +1,33 @@
+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
+		}
+	}
+}

builder/config.go

@@ -25,8 +25,8 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
 	}
-	if major != 1 || minor < 11 || minor > 15 {
-		return nil, fmt.Errorf("requires go version 1.11 through 1.15, got go%d.%d", major, minor)
+	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)
 	}
 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
 	return &compileopts.Config{

builder/jobs.go

@@ -0,0 +1,173 @@
+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
+	}
+}

builder/library.go

@@ -1,7 +1,6 @@
 package builder
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -40,34 +39,62 @@ func (l *Library) sourcePaths(target string) []string {
 }
 
 // Load the library archive, possibly generating and caching it if needed.
-func (l *Library) Load(target string) (path string, err error) {
+// 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) {
 	// 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 precompiledPath, nil
+		return dummyCompileJob(precompiledPath), nil
 	}
 
-	outfile := l.name + "-" + target + ".a"
+	var outfile string
+	if cpu != "" {
+		outfile = l.name + "-" + target + "-" + cpu + ".a"
+	} else {
+		outfile = l.name + "-" + target + ".a"
+	}
 
 	// Try to fetch this library from the cache.
-	if path, err := cacheLoad(outfile, commands["clang"][0], l.sourcePaths(target)); path != "" || err != nil {
+	if path, err := cacheLoad(outfile, l.sourcePaths(target)); path != "" || err != nil {
 		// Cache hit.
-		return path, err
+		return dummyCompileJob(path), nil
 	}
 	// Cache miss, build it now.
 
-	dirPrefix := "tinygo-" + l.name
-	remapDir := filepath.Join(os.TempDir(), dirPrefix)
-	dir, err := ioutil.TempDir(os.TempDir(), dirPrefix)
+	remapDir := filepath.Join(os.TempDir(), "tinygo-"+l.name)
+	dir := filepath.Join(tmpdir, "build-lib-"+l.name)
+	err = os.Mkdir(dir, 0777)
 	if err != nil {
-		return "", err
+		return nil, 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")
 	}
@@ -78,28 +105,45 @@ func (l *Library) Load(target string) (path string, err error) {
 		args = append(args, "-march=rv64gc", "-mabi=lp64")
 	}
 
-	// Compile all sources.
+	// Create job to put all the object files in a single archive. This archive
+	// file is the (static) library file.
 	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)
-		// 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}
-		}
+		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
+			},
+		})
 	}
 
-	// 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))
+	return job, nil
 }

builder/tools.go

@@ -9,8 +9,8 @@ import (
 )
 
 // runCCompiler invokes a C compiler with the given arguments.
-func runCCompiler(command string, flags ...string) error {
-	if hasBuiltinTools && command == "clang" {
+func runCCompiler(flags ...string) error {
+	if hasBuiltinTools {
 		// Compile this with the internal Clang compiler.
 		headerPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
 		if headerPath == "" {
@@ -23,17 +23,8 @@ func runCCompiler(command string, flags ...string) error {
 		return cmd.Run()
 	}
 
-	// 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()
+	// Compile this with an external invocation of the Clang compiler.
+	return execCommand(commands["clang"], flags...)
 }
 
 // link invokes a linker with the given name and flags.

cgo/cgo.go

@@ -41,7 +41,9 @@ type cgoPackage struct {
 	elaboratedTypes map[string]*elaboratedTypeInfo
 	enums           map[string]enumInfo
 	anonStructNum   int
-	ldflags         []string
+	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
@@ -54,9 +56,10 @@ 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
+	args     []paramInfo
+	results  *ast.FieldList
+	pos      token.Pos
+	variadic bool
 }
 
 // paramInfo is a parameter of a CGo function (see functionInfo).
@@ -155,9 +158,10 @@ 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. 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, []error) {
+// 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) {
 	p := &cgoPackage{
 		dir:             dir,
 		fset:            fset,
@@ -169,13 +173,9 @@ 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 +184,7 @@ 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, []error{
+		return nil, nil, nil, nil, []error{
 			scanner.Error{
 				Pos: fset.Position(files[0].Pos()),
 				Msg: "cgo: cannot find absolute path: " + err.Error(), // TODO: wrap this error
@@ -359,7 +359,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 						continue
 					}
 					makePathsAbsolute(flags, packagePath)
-					cflags = append(cflags, flags...)
+					p.cflags = append(p.cflags, flags...)
 				case "LDFLAGS":
 					flags, err := shlex.Split(value)
 					if err != nil {
@@ -382,6 +382,13 @@ 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()
@@ -391,7 +398,7 @@ 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, cflags, position.Filename, position.Line)
+		p.parseFragment(cgoComment+cgoTypes, cflagsForCGo, position.Filename, position.Line)
 	}
 
 	// Declare functions found by libclang.
@@ -426,7 +433,7 @@ 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.ldflags, p.errors
+	return p.generated, p.cflags, p.ldflags, p.visitedFiles, p.errors
 }
 
 // makePathsAbsolute converts some common path compiler flags (-I, -L) from
@@ -484,6 +491,16 @@ 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{

cgo/cgo_test.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"go/ast"
+	"go/build"
 	"go/format"
 	"go/parser"
 	"go/token"
@@ -23,7 +24,7 @@ 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.Replace(result, "\r\n", "\n", -1)
+	actual := strings.ReplaceAll(result, "\r\n", "\n")
 
 	// 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
@@ -41,6 +42,20 @@ 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()
@@ -50,7 +65,7 @@ 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
@@ -98,7 +113,7 @@ func TestCGo(t *testing.T) {
 			if err != nil {
 				t.Fatalf("could not read expected output: %v", err)
 			}
-			expected := strings.Replace(string(expectedBytes), "\r\n", "\n", -1)
+			expected := strings.ReplaceAll(string(expectedBytes), "\r\n", "\n")
 
 			// Check whether the output is as expected.
 			if expected != actual {
@@ -139,7 +154,7 @@ func formatDiagnostic(err error) string {
 	msg := err.Error()
 	if runtime.GOOS == "windows" {
 		// Fix Windows path slashes.
-		msg = strings.Replace(msg, "testdata\\", "testdata/", -1)
+		msg = strings.ReplaceAll(msg, "testdata\\", "testdata/")
 	}
 	return "//     " + msg + "\n"
 }

cgo/libclang.go

@@ -4,6 +4,7 @@ package cgo
 // modification. It does not touch the AST itself.
 
 import (
+	"crypto/sha512"
 	"fmt"
 	"go/ast"
 	"go/scanner"
@@ -56,6 +57,7 @@ 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"
 
@@ -114,6 +116,7 @@ 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))
@@ -134,10 +137,36 @@ 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
@@ -152,12 +181,10 @@ 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,
+			pos:      pos,
+			variadic: C.clang_isFunctionTypeVariadic(cursorType) != 0,
 		}
 		p.functions[name] = fn
 		for i := 0; i < numArgs; i++ {
@@ -774,3 +801,9 @@ 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)
+}

cgo/libclang_config.go

@@ -1,14 +1,14 @@
 // +build !byollvm
-// +build !llvm9,!llvm11
+// +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
+#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
 */
 import "C"

cgo/libclang_config_llvm10.go

@@ -0,0 +1,14 @@
+// +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"

cgo/libclang_config_llvm11.go

@@ -1,14 +0,0 @@
-// +build !byollvm
-// +build llvm11
-
-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
-*/
-import "C"

cgo/libclang_config_llvm9.go

@@ -1,14 +0,0 @@
-// +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"

cgo/testdata/errors.out.go

@@ -4,10 +4,10 @@
 //     testdata/errors.go:13:23: unexpected token )
 
 // Type checking errors after CGo processing:
-//     testdata/errors.go:102: 2 << 10 (untyped int constant 2048) overflows uint8
+//     testdata/errors.go:102: cannot use 2 << 10 (untyped int constant 2048) as uint8 value in variable declaration (overflows)
 //     testdata/errors.go:105: unknown field z in struct literal
 //     testdata/errors.go:108: undeclared name: C.SOME_CONST_1
-//     testdata/errors.go:110: C.SOME_CONST_3 (untyped int constant 1234) overflows byte
+//     testdata/errors.go:110: cannot use C.SOME_CONST_3 (untyped int constant 1234) as byte value in variable declaration (overflows)
 
 package main
 

cgo/testdata/types.go

@@ -104,6 +104,10 @@ 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"
 
@@ -163,3 +167,9 @@ 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)
+}

cgo/testdata/types.out.go

@@ -4,6 +4,11 @@ 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

compileopts/config.go

@@ -21,29 +21,6 @@ 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
@@ -141,16 +118,47 @@ 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() FuncValueImplementation {
-	// Always pick the switch implementation, as it allows the use of blocking
-	// inside a function that is used as a func value.
+func (c *Config) FuncImplementation() string {
 	switch c.Scheduler() {
-	case "none", "coroutines":
-		return FuncValueSwitch
 	case "tasks":
-		return FuncValueDoubleword
+		// 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"
 	default:
 		panic("unknown scheduler type")
 	}
@@ -176,9 +184,9 @@ func (c *Config) AutomaticStackSize() bool {
 // CFlags returns the flags to pass to the C compiler. This is necessary for CGo
 // preprocessing.
 func (c *Config) CFlags() []string {
-	cflags := append([]string{}, c.Options.CFlags...)
+	var cflags []string
 	for _, flag := range c.Target.CFlags {
-		cflags = append(cflags, strings.Replace(flag, "{root}", goenv.Get("TINYGOROOT"), -1))
+		cflags = append(cflags, strings.ReplaceAll(flag, "{root}", goenv.Get("TINYGOROOT")))
 	}
 	if c.Target.Libc == "picolibc" {
 		root := goenv.Get("TINYGOROOT")
@@ -197,9 +205,9 @@ func (c *Config) CFlags() []string {
 func (c *Config) LDFlags() []string {
 	root := goenv.Get("TINYGOROOT")
 	// Merge and adjust LDFlags.
-	ldflags := append([]string{}, c.Options.LDFlags...)
+	var ldflags []string
 	for _, flag := range c.Target.LDFlags {
-		ldflags = append(ldflags, strings.Replace(flag, "{root}", root, -1))
+		ldflags = append(ldflags, strings.ReplaceAll(flag, "{root}", root))
 	}
 	ldflags = append(ldflags, "-L", root)
 	if c.Target.LinkerScript != "" {

compileopts/options.go

@@ -2,6 +2,7 @@ package compileopts
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 )
 
@@ -10,6 +11,7 @@ var (
 	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
@@ -26,11 +28,11 @@ type Options struct {
 	PrintCommands bool
 	Debug         bool
 	PrintSizes    string
+	PrintAllocs   *regexp.Regexp // regexp string
 	PrintStacks   bool
-	CFlags        []string
-	LDFlags       []string
 	Tags          string
 	WasmAbi       string
+	GlobalValues  map[string]map[string]string // map[pkgpath]map[varname]value
 	TestConfig    TestConfig
 	Programmer    string
 }
@@ -73,6 +75,12 @@ func (o *Options) Verify() error {
 		}
 	}
 
+	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
 }
 

compileopts/target.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"io"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"reflect"
 	"runtime"
@@ -30,7 +31,6 @@ 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"`
@@ -42,7 +42,7 @@ type TargetSpec struct {
 	ExtraFiles       []string `json:"extra-files"`
 	Emulator         []string `json:"emulator" override:"copy"` // inherited Emulator must not be append
 	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"`
@@ -229,7 +229,13 @@ 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{
@@ -237,10 +243,9 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 		GOOS:      goos,
 		GOARCH:    goarch,
 		BuildTags: []string{goos, goarch},
-		Compiler:  "clang",
 		Linker:    "cc",
 		CFlags:    []string{"--target=" + triple},
-		GDB:       "gdb",
+		GDB:       []string{"gdb"},
 		PortReset: "false",
 	}
 	if goos == "darwin" {
@@ -253,7 +258,7 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	}
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
-		spec.GDB = "gdb-multiarch"
+		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"
@@ -271,3 +276,17 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	}
 	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, ", ") + ")")
+}

compiler/asserts.go

@@ -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.fn.IsNoBounds() {
+	if b.info.nobounds {
 		// 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.fn.IsNoBounds() {
+	if b.info.nobounds {
 		// 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.fn.IsNoBounds() {
+	if b.info.nobounds {
 		// The //go:nobounds pragma was added to the function to avoid bounds
 		// checking.
 		return
@@ -159,6 +159,9 @@ 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
@@ -189,7 +192,7 @@ 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.fn.IsNoBounds() {
+	if b.info.nobounds {
 		// Function disabled bounds checking - skip shift check.
 		return
 	}
@@ -212,8 +215,8 @@ func (b *builder) createRuntimeAssert(assert llvm.Value, blockPrefix, assertFunc
 		}
 	}
 
-	faultBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, blockPrefix+".throw")
-	nextBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, blockPrefix+".next")
+	faultBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".throw")
+	nextBlock := b.ctx.AddBasicBlock(b.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.

compiler/atomic.go

@@ -1,6 +1,8 @@
 package compiler
 
 import (
+	"strings"
+
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -35,6 +37,31 @@ func (b *builder) createAtomicOp(call *ssa.CallCommon) (llvm.Value, bool) {
 		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

compiler/calls.go

@@ -4,6 +4,7 @@ import (
 	"go/types"
 	"strconv"
 
+	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
 
@@ -34,14 +35,14 @@ 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 {
-	fullName := "runtime." + fnName
-	fn := b.mod.NamedFunction(fullName)
-	if fn.IsNil() {
-		panic("trying to call non-existent function: " + fullName)
+	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))
 	}
 	args = append(args, llvm.Undef(b.i8ptrType))            // unused context parameter
 	args = append(args, llvm.ConstPointerNull(b.i8ptrType)) // coroutine handle
-	return b.createCall(fn, args, name)
+	return b.createCall(llvmFn, args, name)
 }
 
 // createCall creates a call to the given function with the arguments possibly
@@ -57,10 +58,10 @@ 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 expandFormalParamType(t llvm.Type, name string, goType types.Type) []paramInfo {
+func (c *compilerContext) expandFormalParamType(t llvm.Type, name string, goType types.Type) []paramInfo {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		fieldInfos := flattenAggregateType(t, name, goType)
+		fieldInfos := c.flattenAggregateType(t, name, goType)
 		if len(fieldInfos) <= maxFieldsPerParam {
 			return fieldInfos
 		} else {
@@ -104,7 +105,7 @@ 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 := flattenAggregateType(v.Type(), "", nil)
+		fieldInfos := b.flattenAggregateType(v.Type(), "", nil)
 		if len(fieldInfos) <= maxFieldsPerParam {
 			fields := b.flattenAggregate(v)
 			if len(fields) != len(fieldInfos) {
@@ -123,12 +124,15 @@ 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 flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramInfo {
+func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramInfo {
 	typeFlags := getTypeFlags(goType)
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		paramInfos := make([]paramInfo, 0, t.StructElementTypesCount())
+		var paramInfos []paramInfo
 		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,
@@ -151,7 +155,7 @@ func flattenAggregateType(t llvm.Type, name string, goType types.Type) []paramIn
 					suffix = []string{"context", "funcptr"}[i]
 				}
 			}
-			subInfos := flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
+			subInfos := c.flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
 			for i := range subInfos {
 				subInfos[i].flags |= typeFlags
 			}
@@ -217,8 +221,11 @@ func extractSubfield(t types.Type, field int) types.Type {
 func (c *compilerContext) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
 	switch t.TypeKind() {
 	case llvm.StructTypeKind:
-		fields := make([]uint64, 0, t.StructElementTypesCount())
+		var fields []uint64
 		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 {
@@ -237,8 +244,11 @@ func (c *compilerContext) flattenAggregateTypeOffsets(t llvm.Type) []uint64 {
 func (b *builder) flattenAggregate(v llvm.Value) []llvm.Value {
 	switch v.Type().TypeKind() {
 	case llvm.StructTypeKind:
-		fields := make([]llvm.Value, 0, v.Type().StructElementTypesCount())
-		for i := range v.Type().StructElementTypes() {
+		var fields []llvm.Value
+		for i, field := range v.Type().StructElementTypes() {
+			if b.targetData.TypeAllocSize(field) == 0 {
+				continue
+			}
 			subfield := b.CreateExtractValue(v, i, "")
 			subfields := b.flattenAggregate(subfield)
 			fields = append(fields, subfields...)
@@ -265,10 +275,13 @@ 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 := flattenAggregateType(t, "", nil)
+		flattened := b.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, "")

compiler/channel.go

@@ -79,8 +79,7 @@ func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
 }
 
 // createChanClose closes the given channel.
-func (b *builder) createChanClose(param ssa.Value) {
-	ch := b.getValue(param)
+func (b *builder) createChanClose(ch llvm.Value) {
 	b.createRuntimeCall("chanClose", []llvm.Value{ch}, "")
 }
 

compiler/compiler_test.go

@@ -4,7 +4,6 @@ import (
 	"flag"
 	"go/types"
 	"io/ioutil"
-	"regexp"
 	"strconv"
 	"strings"
 	"testing"
@@ -20,6 +19,19 @@ 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("i686--linux")
 	if err != nil {
 		t.Fatal("failed to load target:", err)
@@ -28,7 +40,17 @@ func TestCompiler(t *testing.T) {
 		Options: &compileopts.Options{},
 		Target:  target,
 	}
-	machine, err := NewTargetMachine(config)
+	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)
 	}
@@ -37,6 +59,10 @@ func TestCompiler(t *testing.T) {
 		"basic.go",
 		"pointer.go",
 		"slice.go",
+		"string.go",
+		"float.go",
+		"interface.go",
+		"func.go",
 	}
 
 	for _, testCase := range tests {
@@ -54,15 +80,21 @@ func TestCompiler(t *testing.T) {
 			}
 
 			// Compile AST to IR.
+			program := lprogram.LoadSSA()
 			pkg := lprogram.MainPkg()
-			mod, errs := CompilePackage(testCase, pkg, machine, config)
+			mod, errs := CompilePackage(testCase, pkg, program.Package(pkg.Pkg), machine, compilerConfig, false)
 			if errs != nil {
 				for _, err := range errs {
-					t.Log("error:", err)
+					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()
@@ -96,8 +128,6 @@ func TestCompiler(t *testing.T) {
 	}
 }
 
-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.).
@@ -109,15 +139,6 @@ func fuzzyEqualIR(s1, s2 string) bool {
 	}
 	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 {
 			return false
 		}
@@ -131,12 +152,6 @@ func fuzzyEqualIR(s1, s2 string) bool {
 // stripped out.
 func filterIrrelevantIRLines(lines []string) []string {
 	var out []string
-	llvmVersion, err := strconv.Atoi(strings.Split(llvm.Version, ".")[0])
-	if err != nil {
-		// Note: this should never happen and if it does, it will always happen
-		// for a particular build because llvm.Version is a constant.
-		panic(err)
-	}
 	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
@@ -146,15 +161,6 @@ func filterIrrelevantIRLines(lines []string) []string {
 		if strings.HasPrefix(line, "source_filename = ") {
 			continue
 		}
-		if llvmVersion < 10 && strings.HasPrefix(line, "attributes ") {
-			// Ignore attribute groups. These may change between LLVM versions.
-			// Right now test outputs are for LLVM 10.
-			continue
-		}
-		if llvmVersion < 10 && strings.HasPrefix(line, "target datalayout ") {
-			// Ignore the target layout. This may change between LLVM versions.
-			continue
-		}
 		out = append(out, line)
 	}
 	return out

compiler/defer.go

@@ -14,9 +14,9 @@ package compiler
 //     frames.
 
 import (
-	"github.com/tinygo-org/tinygo/compiler/llvmutil"
-	"github.com/tinygo-org/tinygo/ir"
 	"go/types"
+
+	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -26,9 +26,9 @@ import (
 // calls.
 func (b *builder) deferInitFunc() {
 	// Some setup.
-	b.deferFuncs = make(map[*ir.Function]int)
+	b.deferFuncs = make(map[*ssa.Function]int)
 	b.deferInvokeFuncs = make(map[string]int)
-	b.deferClosureFuncs = make(map[*ir.Function]int)
+	b.deferClosureFuncs = make(map[*ssa.Function]int)
 	b.deferExprFuncs = make(map[ssa.Value]int)
 	b.deferBuiltinFuncs = make(map[ssa.Value]deferBuiltin)
 
@@ -107,13 +107,11 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 
 	} else if callee, ok := instr.Call.Value.(*ssa.Function); ok {
 		// Regular function call.
-		fn := b.ir.GetFunction(callee)
-
-		if _, ok := b.deferFuncs[fn]; !ok {
-			b.deferFuncs[fn] = len(b.allDeferFuncs)
-			b.allDeferFuncs = append(b.allDeferFuncs, fn)
+		if _, ok := b.deferFuncs[callee]; !ok {
+			b.deferFuncs[callee] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, callee)
 		}
-		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferFuncs[fn]), false)
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferFuncs[callee]), false)
 
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields).
@@ -135,7 +133,7 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		context := b.CreateExtractValue(closure, 0, "")
 
 		// Get the callback number.
-		fn := b.ir.GetFunction(makeClosure.Fn.(*ssa.Function))
+		fn := makeClosure.Fn.(*ssa.Function)
 		if _, ok := b.deferClosureFuncs[fn]; !ok {
 			b.deferClosureFuncs[fn] = len(b.allDeferFuncs)
 			b.allDeferFuncs = append(b.allDeferFuncs, makeClosure)
@@ -155,19 +153,19 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		valueTypes = append(valueTypes, context.Type())
 
 	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
-		var funcName string
-		switch builtin.Name() {
-		case "close":
-			funcName = "chanClose"
-		default:
-			b.addError(instr.Pos(), "todo: Implement defer for "+builtin.Name())
-			return
+		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{
-				funcName,
-				len(b.allDeferFuncs),
+				callName: builtin.Name(),
+				pos:      builtin.Pos(),
+				argTypes: argTypes,
+				callback: len(b.allDeferFuncs),
 			}
 			b.allDeferFuncs = append(b.allDeferFuncs, instr.Call.Value)
 		}
@@ -176,10 +174,9 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields).
 		values = []llvm.Value{callback, next}
-		for _, param := range instr.Call.Args {
-			llvmParam := b.getValue(param)
-			values = append(values, llvmParam)
-			valueTypes = append(valueTypes, llvmParam.Type())
+		for _, param := range argValues {
+			values = append(values, param)
+			valueTypes = append(valueTypes, param.Type())
 		}
 
 	} else {
@@ -223,7 +220,7 @@ 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)
@@ -251,10 +248,10 @@ func (b *builder) createRunDefers() {
 	//     }
 
 	// Create loop.
-	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")
+	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")
 	b.CreateBr(loophead)
 
 	// Create loop head:
@@ -286,7 +283,7 @@ func (b *builder) createRunDefers() {
 		// Create switch case, for example:
 		//     case 0:
 		//         // run first deferred call
-		block := b.ctx.AddBasicBlock(b.fn.LLVMFn, "rundefers.callback")
+		block := b.ctx.AddBasicBlock(b.llvmFn, "rundefers.callback")
 		sw.AddCase(llvm.ConstInt(b.uintptrType, uint64(i), false), block)
 		b.SetInsertPointAtEnd(block)
 		switch callback := callback.(type) {
@@ -350,12 +347,12 @@ func (b *builder) createRunDefers() {
 
 			b.createCall(fnPtr, forwardParams, "")
 
-		case *ir.Function:
+		case *ssa.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 callback.Params {
+			for _, param := range getParams(callback.Signature) {
 				valueTypes = append(valueTypes, b.getLLVMType(param.Type()))
 			}
 			deferFrameType := b.ctx.StructType(valueTypes, false)
@@ -364,7 +361,7 @@ func (b *builder) createRunDefers() {
 			// Extract the params from the struct.
 			forwardParams := []llvm.Value{}
 			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
-			for i := range callback.Params {
+			for i := range getParams(callback.Signature) {
 				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)
@@ -372,7 +369,7 @@ 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 !callback.IsExported() {
+			if !b.getFunctionInfo(callback).exported {
 				// 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))
@@ -382,11 +379,11 @@ func (b *builder) createRunDefers() {
 			}
 
 			// Call real function.
-			b.createCall(callback.LLVMFn, forwardParams, "")
+			b.createCall(b.getFunction(callback), forwardParams, "")
 
 		case *ssa.MakeClosure:
 			// Get the real defer struct type and cast to it.
-			fn := b.ir.GetFunction(callback.Fn.(*ssa.Function))
+			fn := 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++ {
@@ -409,7 +406,7 @@ func (b *builder) createRunDefers() {
 			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
 
 			// Call deferred function.
-			b.createCall(fn.LLVMFn, forwardParams, "")
+			b.createCall(b.getFunction(fn), forwardParams, "")
 		case *ssa.Builtin:
 			db := b.deferBuiltinFuncs[callback]
 
@@ -426,15 +423,18 @@ func (b *builder) createRunDefers() {
 			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
 			// Extract the params from the struct.
-			var forwardParams []llvm.Value
+			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")
-				forwardParams = append(forwardParams, forwardParam)
+				argValues = append(argValues, forwardParam)
 			}
 
-			b.createRuntimeCall(db.funcName, forwardParams, "")
+			_, 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")
 		}

compiler/errors.go

@@ -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.ir.Program.Fset,
+		Fset: c.program.Fset,
 		Pos:  pos,
 		Msg:  msg,
 	}

compiler/func.go

@@ -6,7 +6,6 @@ package compiler
 import (
 	"go/types"
 
-	"github.com/tinygo-org/tinygo/compileopts"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -21,24 +20,23 @@ 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 compileopts.FuncValueDoubleword:
+	switch c.FuncImplementation {
+	case "doubleword":
 		// Closure is: {context, function pointer}
 		funcValueScalar = funcPtr
-	case compileopts.FuncValueSwitch:
-		sigGlobal := c.getTypeCode(sig)
+	case "switch":
 		funcValueWithSignatureGlobalName := funcPtr.Name() + "$withSignature"
 		funcValueWithSignatureGlobal := c.mod.NamedGlobal(funcValueWithSignatureGlobalName)
 		if funcValueWithSignatureGlobal.IsNil() {
 			funcValueWithSignatureType := c.getLLVMRuntimeType("funcValueWithSignature")
 			funcValueWithSignature := llvm.ConstNamedStruct(funcValueWithSignatureType, []llvm.Value{
 				llvm.ConstPtrToInt(funcPtr, c.uintptrType),
-				sigGlobal,
+				c.getFuncSignatureID(sig),
 			})
 			funcValueWithSignatureGlobal = llvm.AddGlobal(c.mod, funcValueWithSignatureType, funcValueWithSignatureGlobalName)
 			funcValueWithSignatureGlobal.SetInitializer(funcValueWithSignature)
 			funcValueWithSignatureGlobal.SetGlobalConstant(true)
-			funcValueWithSignatureGlobal.SetLinkage(llvm.InternalLinkage)
+			funcValueWithSignatureGlobal.SetLinkage(llvm.LinkOnceODRLinkage)
 		}
 		funcValueScalar = llvm.ConstPtrToInt(funcValueWithSignatureGlobal, c.uintptrType)
 	default:
@@ -51,6 +49,19 @@ 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 {
@@ -67,12 +78,12 @@ 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 compileopts.FuncValueDoubleword:
+	switch b.FuncImplementation {
+	case "doubleword":
 		funcPtr = b.CreateExtractValue(funcValue, 1, "")
-	case compileopts.FuncValueSwitch:
+	case "switch":
 		llvmSig := b.getRawFuncType(sig)
-		sigGlobal := b.getTypeCode(sig)
+		sigGlobal := b.getFuncSignatureID(sig)
 		funcPtr = b.createRuntimeCall("getFuncPtr", []llvm.Value{funcValue, sigGlobal}, "")
 		funcPtr = b.CreateIntToPtr(funcPtr, llvmSig, "")
 	default:
@@ -83,11 +94,11 @@ 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 compileopts.FuncValueDoubleword:
+	switch c.FuncImplementation {
+	case "doubleword":
 		rawPtr := c.getRawFuncType(typ)
 		return c.ctx.StructType([]llvm.Type{c.i8ptrType, rawPtr}, false)
-	case compileopts.FuncValueSwitch:
+	case "switch":
 		return c.getLLVMRuntimeType("funcValue")
 	default:
 		panic("unimplemented func value variant")
@@ -125,13 +136,13 @@ 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 expandFormalParamType(recv, "", nil) {
+		for _, info := range c.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 expandFormalParamType(subType, "", nil) {
+		for _, info := range c.expandFormalParamType(subType, "", nil) {
 			paramTypes = append(paramTypes, info.llvmType)
 		}
 	}
@@ -149,7 +160,7 @@ func (b *builder) parseMakeClosure(expr *ssa.MakeClosure) (llvm.Value, error) {
 	if len(expr.Bindings) == 0 {
 		panic("unexpected: MakeClosure without bound variables")
 	}
-	f := b.ir.GetFunction(expr.Fn.(*ssa.Function))
+	f := expr.Fn.(*ssa.Function)
 
 	// Collect all bound variables.
 	boundVars := make([]llvm.Value, len(expr.Bindings))
@@ -164,5 +175,5 @@ func (b *builder) parseMakeClosure(expr *ssa.MakeClosure) (llvm.Value, error) {
 	context := b.emitPointerPack(boundVars)
 
 	// Create the closure.
-	return b.createFuncValue(f.LLVMFn, context, f.Signature), nil
+	return b.createFuncValue(b.getFunction(f), context, f.Signature), nil
 }

compiler/goroutine.go

@@ -7,6 +7,7 @@ import (
 	"go/token"
 
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
+	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
 
@@ -20,19 +21,20 @@ import (
 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() {
+	switch b.Scheduler {
 	case "none", "tasks":
 		callee = b.createGoroutineStartWrapper(funcPtr, prefix, pos)
-		if b.AutomaticStackSize() {
+		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).
-			stackSize = b.createCall(b.mod.NamedFunction("internal/task.getGoroutineStackSize"), []llvm.Value{callee, llvm.Undef(b.i8ptrType), llvm.Undef(b.i8ptrType)}, "stacksize")
+			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.
-			stackSize = llvm.ConstInt(b.uintptrType, b.Target.DefaultStackSize, false)
+			stackSize = llvm.ConstInt(b.uintptrType, b.DefaultStackSize, false)
 		}
 	case "coroutines":
 		callee = b.CreatePtrToInt(funcPtr, b.uintptrType, "")
@@ -42,7 +44,8 @@ func (b *builder) createGoInstruction(funcPtr llvm.Value, params []llvm.Value, p
 	default:
 		panic("unreachable")
 	}
-	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
+	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)}, "")
 	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
 }
 
@@ -81,14 +84,14 @@ 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.InternalLinkage)
+		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
 		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.ir.Program.Fset.Position(pos)
+		if c.Debug {
+			pos := c.program.Fset.Position(pos)
 			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
 				File:       c.getDIFile(pos.Filename),
 				Parameters: nil, // do not show parameters in debugger
@@ -138,14 +141,14 @@ 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.InternalLinkage)
+		wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
 		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.ir.Program.Fset.Position(pos)
+		if c.Debug {
+			pos := c.program.Fset.Position(pos)
 			diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
 				File:       c.getDIFile(pos.Filename),
 				Parameters: nil, // do not show parameters in debugger

compiler/interface.go

@@ -11,7 +11,6 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/tinygo-org/tinygo/ir"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -25,16 +24,7 @@ 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)
-	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, "")
+	itfTypeCode := b.CreatePtrToInt(itfTypeCodeGlobal, b.uintptrType, "")
 	itf := llvm.Undef(b.getLLVMRuntimeType("_interface"))
 	itf = b.CreateInsertValue(itf, itfTypeCode, 0, "")
 	itf = b.CreateInsertValue(itf, itfValue, 1, "")
@@ -55,6 +45,8 @@ 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())
@@ -71,18 +63,32 @@ 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
@@ -104,8 +110,8 @@ func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
 		fieldName.SetLinkage(llvm.PrivateLinkage)
 		fieldName.SetUnnamedAddr(true)
 		fieldName = llvm.ConstGEP(fieldName, []llvm.Value{
-			llvm.ConstInt(llvm.Int32Type(), 0, false),
-			llvm.ConstInt(llvm.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+			llvm.ConstInt(c.ctx.Int32Type(), 0, false),
 		})
 		fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldName, []uint32{1})
 		if typ.Tag(i) != "" {
@@ -113,8 +119,8 @@ func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
 			fieldTag.SetLinkage(llvm.PrivateLinkage)
 			fieldTag.SetUnnamedAddr(true)
 			fieldTag = llvm.ConstGEP(fieldTag, []llvm.Value{
-				llvm.ConstInt(llvm.Int32Type(), 0, false),
-				llvm.ConstInt(llvm.Int32Type(), 0, false),
+				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
+				llvm.ConstInt(c.ctx.Int32Type(), 0, false),
 			})
 			fieldGlobalValue = llvm.ConstInsertValue(fieldGlobalValue, fieldTag, []uint32{2})
 		}
@@ -187,7 +193,7 @@ func getTypeCodeName(t types.Type) string {
 	case *types.Interface:
 		methods := make([]string, t.NumMethods())
 		for i := 0; i < t.NumMethods(); i++ {
-			methods[i] = getTypeCodeName(t.Method(i).Type())
+			methods[i] = t.Method(i).Name() + ":" + getTypeCodeName(t.Method(i).Type())
 		}
 		return "interface:" + "{" + strings.Join(methods, ",") + "}"
 	case *types.Map:
@@ -236,7 +242,7 @@ func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 		return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 	}
 
-	ms := c.ir.Program.MethodSets.MethodSet(typ)
+	ms := c.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))
@@ -247,15 +253,16 @@ 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))
-		f := c.ir.GetFunction(c.ir.Program.MethodValue(method))
-		if f.LLVMFn.IsNil() {
+		fn := c.program.MethodValue(method)
+		llvmFn := c.getFunction(fn)
+		if llvmFn.IsNil() {
 			// compiler error, so panic
-			panic("cannot find function: " + f.LinkName())
+			panic("cannot find function: " + c.getFunctionInfo(fn).linkName)
 		}
-		fn := c.getInterfaceInvokeWrapper(f)
+		wrapper := c.getInterfaceInvokeWrapper(fn, llvmFn)
 		methodInfo := llvm.ConstNamedStruct(interfaceMethodInfoType, []llvm.Value{
 			signatureGlobal,
-			llvm.ConstPtrToInt(fn, c.uintptrType),
+			llvm.ConstPtrToInt(wrapper, c.uintptrType),
 		})
 		methods[i] = methodInfo
 	}
@@ -264,7 +271,7 @@ 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.PrivateLinkage)
+	global.SetLinkage(llvm.LinkOnceODRLinkage)
 	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }
 
@@ -295,7 +302,7 @@ 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.PrivateLinkage)
+	global.SetLinkage(llvm.LinkOnceODRLinkage)
 	return llvm.ConstGEP(global, []llvm.Value{zero, zero})
 }
 
@@ -303,7 +310,7 @@ 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 := ir.MethodSignature(method)
+	signature := methodSignature(method)
 	signatureGlobal := c.mod.NamedGlobal("func " + signature)
 	if signatureGlobal.IsNil() {
 		signatureGlobal = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), "func "+signature)
@@ -338,10 +345,16 @@ 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")
 	}
 
@@ -357,8 +370,8 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 	// value.
 
 	prevBlock := b.GetInsertBlock()
-	okBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, "typeassert.ok")
-	nextBlock := b.ctx.AddBasicBlock(b.fn.LLVMFn, "typeassert.next")
+	okBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.ok")
+	nextBlock := b.ctx.AddBasicBlock(b.llvmFn, "typeassert.next")
 	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
 	b.CreateCondBr(commaOk, okBlock, nextBlock)
 
@@ -436,8 +449,8 @@ 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(f *ir.Function) llvm.Value {
-	wrapperName := f.LinkName() + "$invoke"
+func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFn llvm.Value) llvm.Value {
+	wrapperName := llvmFn.Name() + "$invoke"
 	wrapper := c.mod.NamedFunction(wrapperName)
 	if !wrapper.IsNil() {
 		// Wrapper already created. Return it directly.
@@ -445,9 +458,9 @@ func (c *compilerContext) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
 	}
 
 	// Get the expanded receiver type.
-	receiverType := c.getLLVMType(f.Params[0].Type())
+	receiverType := c.getLLVMType(fn.Signature.Recv().Type())
 	var expandedReceiverType []llvm.Type
-	for _, info := range expandFormalParamType(receiverType, "", nil) {
+	for _, info := range c.expandFormalParamType(receiverType, "", nil) {
 		expandedReceiverType = append(expandedReceiverType, info.llvmType)
 	}
 
@@ -457,17 +470,17 @@ func (c *compilerContext) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
 		// Casting a function signature to a different signature and calling it
 		// with a receiver pointer bitcasted to *i8 (as done in calls on an
 		// interface) is hopefully a safe (defined) operation.
-		return f.LLVMFn
+		return llvmFn
 	}
 
 	// create wrapper function
-	fnType := f.LLVMFn.Type().ElementType()
+	fnType := 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")
 
-	wrapper.SetLinkage(llvm.InternalLinkage)
+	wrapper.SetLinkage(llvm.LinkOnceODRLinkage)
 	wrapper.SetUnnamedAddr(true)
 
 	// Create a new builder just to create this wrapper.
@@ -478,9 +491,9 @@ func (c *compilerContext) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
 	defer b.Builder.Dispose()
 
 	// add debug info if needed
-	if c.Debug() {
-		pos := c.ir.Program.Fset.Position(f.Pos())
-		difunc := c.attachDebugInfoRaw(f, wrapper, "$invoke", pos.Filename, pos.Line)
+	if c.Debug {
+		pos := c.program.Fset.Position(fn.Pos())
+		difunc := c.attachDebugInfoRaw(fn, wrapper, "$invoke", pos.Filename, pos.Line)
 		b.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 	}
 
@@ -490,13 +503,60 @@ func (c *compilerContext) getInterfaceInvokeWrapper(f *ir.Function) llvm.Value {
 
 	receiverValue := b.emitPointerUnpack(wrapper.Param(0), []llvm.Type{receiverType})[0]
 	params := append(b.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
-	if f.LLVMFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
-		b.CreateCall(f.LLVMFn, params, "")
+	if llvmFn.Type().ElementType().ReturnType().TypeKind() == llvm.VoidTypeKind {
+		b.CreateCall(llvmFn, params, "")
 		b.CreateRetVoid()
 	} else {
-		ret := b.CreateCall(f.LLVMFn, params, "ret")
+		ret := b.CreateCall(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
+}

compiler/interrupt.go

@@ -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.ir.Program.ImportedPackage("runtime/interrupt").Type("handle").Type()
+	globalType := b.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.SetLinkage(llvm.PrivateLinkage)
+	global.SetVisibility(llvm.HiddenVisibility)
 	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.ir.Program.Fset.Position(instr.Pos())
+	if b.Debug {
+		pos := b.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)

compiler/llvm.go

@@ -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.Config, values)
+	return llvmutil.EmitPointerPack(b.Builder, b.mod, b.NeedsStackObjects, values)
 }
 
 // emitPointerUnpack extracts a list of values packed using emitPointerPack.

compiler/llvmutil/wordpack.go

@@ -5,7 +5,6 @@ package llvmutil
 // itself if possible and legal.
 
 import (
-	"github.com/tinygo-org/tinygo/compileopts"
 	"tinygo.org/x/go-llvm"
 )
 
@@ -13,7 +12,7 @@ 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, config *compileopts.Config, values []llvm.Value) llvm.Value {
+func EmitPointerPack(builder llvm.Builder, mod llvm.Module, needsStackObjects bool, values []llvm.Value) llvm.Value {
 	ctx := mod.Context()
 	targetData := llvm.NewTargetData(mod.DataLayout())
 	i8ptrType := llvm.PointerType(mod.Context().Int8Type(), 0)
@@ -101,7 +100,7 @@ func EmitPointerPack(builder llvm.Builder, mod llvm.Module, config *compileopts.
 			llvm.Undef(i8ptrType),            // unused context parameter
 			llvm.ConstPointerNull(i8ptrType), // coroutine handle
 		}, "")
-		if config.NeedsStackObjects() {
+		if needsStackObjects {
 			trackPointer := mod.NamedFunction("runtime.trackPointer")
 			builder.CreateCall(trackPointer, []llvm.Value{
 				packedHeapAlloc,

compiler/sizes.go

@@ -150,6 +150,9 @@ 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())
 	}

compiler/symbol.go

@@ -15,6 +15,309 @@ 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).
@@ -26,25 +329,22 @@ 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(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
-								}
+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
 							}
 						}
 					}
@@ -63,30 +363,26 @@ 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
-		if info.align < 0 || info.align&(info.align-1) != 0 {
+		alignment := c.targetData.ABITypeAlignment(llvmType)
+		if info.align > alignment {
+			alignment = info.align
+		}
+		if alignment <= 0 || alignment&(alignment-1) != 0 {
 			// Check for power-of-two (or 0).
 			// See: https://stackoverflow.com/a/108360
 			c.addError(g.Pos(), "global variable alignment must be a positive power of two")
 		} else {
 			// Set the alignment only when it is a power of two.
-			alignInBits = uint32(info.align) ^ uint32(info.align-1)
-			if info.align > c.targetData.ABITypeAlignment(llvmType) {
-				llvmGlobal.SetAlignment(info.align)
-			}
+			alignInBits = uint32(alignment) ^ uint32(alignment-1)
+			llvmGlobal.SetAlignment(alignment)
 		}
 
-		if c.Debug() && !info.extern {
+		if c.Debug && !info.extern {
 			// Add debug info.
-			// TODO: this should be done for every global in the program, not just
-			// the ones that are referenced from some code.
-			pos := c.ir.Program.Fset.Position(g.Pos())
+			pos := c.program.Fset.Position(g.Pos())
 			diglobal := c.dibuilder.CreateGlobalVariableExpression(c.difiles[pos.Filename], llvm.DIGlobalVariableExpression{
 				Name:        g.RelString(nil),
 				LinkageName: info.linkName,
@@ -145,3 +441,23 @@ 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
+}

compiler/syscall.go

@@ -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)
 	}
 }

compiler/testdata/basic.ll

@@ -3,70 +3,72 @@ source_filename = "basic.go"
 target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
 target triple = "i686--linux"
 
-define internal void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret void
 }
 
-define internal i32 @main.addInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.equalInt(i32 %x, i32 %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatEQ(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatNE(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatLower(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatLowerEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatGreater(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i1 @main.floatGreaterEqual(float %x, float %y, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal float @main.complexReal(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
+define hidden float @main.complexReal(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret float %x.r
 }
 
-define internal float @main.complexImag(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
+define hidden float @main.complexImag(float %x.r, float %x.i, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret float %x.i
 }
 
-define internal { float, float } @main.complexAdd(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+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
@@ -75,7 +77,7 @@ entry:
   ret { float, float } %3
 }
 
-define internal { float, float } @main.complexSub(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+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
@@ -84,7 +86,7 @@ entry:
   ret { float, float } %3
 }
 
-define internal { float, float } @main.complexMul(float %x.r, float %x.i, float %y.r, float %y.i, i8* %context, i8* %parentHandle) unnamed_addr {
+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

compiler/testdata/float.go

@@ -0,0 +1,39 @@
+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)
+}

compiler/testdata/float.ll

@@ -0,0 +1,82 @@
+; ModuleID = 'float.go'
+source_filename = "float.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+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
+}

compiler/testdata/func.go

@@ -0,0 +1,12 @@
+package main
+
+func foo(callback func(int)) {
+	callback(3)
+}
+
+func bar() {
+	foo(someFunc)
+}
+
+func someFunc(int) {
+}

compiler/testdata/func.ll

@@ -0,0 +1,47 @@
+; ModuleID = 'func.go'
+source_filename = "func.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+%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
+}

compiler/testdata/interface.go

@@ -0,0 +1,54 @@
+// 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()
+}

compiler/testdata/interface.ll

@@ -0,0 +1,101 @@
+; ModuleID = 'interface.go'
+source_filename = "interface.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+%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*)

compiler/testdata/pointer.ll

@@ -3,46 +3,48 @@ source_filename = "pointer.go"
 target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
 target triple = "i686--linux"
 
-define internal void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret void
 }
 
-define internal [0 x i32] @main.pointerDerefZero([0 x i32]* %x, i8* %context, i8* %parentHandle) unnamed_addr {
+define hidden [0 x i32] @main.pointerDerefZero([0 x i32]* %x, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret [0 x i32] zeroinitializer
 }
 
-define internal i32* @main.pointerCastFromUnsafe(i8* %x, i8* %context, i8* %parentHandle) unnamed_addr {
+define hidden i32* @main.pointerCastFromUnsafe(i8* %x, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   %0 = bitcast i8* %x to i32*
   ret i32* %0
 }
 
-define internal i8* @main.pointerCastToUnsafe(i32* dereferenceable_or_null(4) %x, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i8* @main.pointerCastToUnsafeNoop(i8* dereferenceable_or_null(1) %x, i8* %context, i8* %parentHandle) unnamed_addr {
+define hidden i8* @main.pointerCastToUnsafeNoop(i8* dereferenceable_or_null(1) %x, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret i8* %x
 }
 
-define internal i8* @main.pointerUnsafeGEPFixedOffset(i8* dereferenceable_or_null(1) %ptr, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i8* @main.pointerUnsafeGEPByteOffset(i8* dereferenceable_or_null(1) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i32* @main.pointerUnsafeGEPIntOffset(i32* dereferenceable_or_null(4) %ptr, i32 %offset, i8* %context, i8* %parentHandle) unnamed_addr {
+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

compiler/testdata/slice.go

@@ -7,3 +7,19 @@ func sliceLen(ints []int) int {
 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)
+}

compiler/testdata/slice.ll

@@ -3,17 +3,86 @@ source_filename = "slice.go"
 target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
 target triple = "i686--linux"
 
-define internal void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
+declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
+
+define hidden void @main.init(i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
   ret void
 }
 
-define internal i32 @main.sliceLen(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+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 internal i32 @main.sliceCap(i32* %ints.data, i32 %ints.len, i32 %ints.cap, i8* %context, i8* %parentHandle) unnamed_addr {
+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*)

compiler/testdata/string.go

@@ -0,0 +1,29 @@
+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
+}

compiler/testdata/string.ll

@@ -0,0 +1,71 @@
+; ModuleID = 'string.go'
+source_filename = "string.go"
+target datalayout = "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i686--linux"
+
+%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*)

go.mod

@@ -1,14 +1,16 @@
 module github.com/tinygo-org/tinygo
 
-go 1.11
+go 1.13
 
 require (
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
-	github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b
-	github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e
+	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
-	go.bug.st/serial v1.0.0
+	github.com/mattn/go-colorable v0.1.8
+	go.bug.st/serial v1.1.2
+	golang.org/x/sys v0.0.0-20210113181707-4bcb84eeeb78
 	golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2
-	tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9
+	tinygo.org/x/go-llvm v0.0.0-20210325115028-e7b85195e81c
 )

go.sum

@@ -1,33 +1,39 @@
 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 v0.0.0-20200116234248-4da64dd111ac/go.mod h1:PfAWWKJqjlGFYJEidUM6aVIWPr0EpobeyVWEEmplX7g=
-github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b h1:LF+GRwyzxrO3MUzPvejv+yBup0lNG+/QdIRrkxOPseA=
-github.com/chromedp/cdproto v0.0.0-20200709115526-d1f6fc58448b/go.mod h1:E6LPWRdIJc11h/di5p0rwvRmUYbhGpBEH7ZbPfzDIOE=
-github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e h1:Hv0JVyHhbIXb9NiYQe4NsrfgrSofAp0q2FnhhJOXgi8=
-github.com/chromedp/chromedp v0.5.4-0.20200303084119-2bb39134ab9e/go.mod h1:vmQMRHFZrY3T+Jv51T0n87OK/i6bK+5P9a+Fg5jPwgQ=
+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 v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah2I+gwHF8xmJWRjooY+5248k6m4A0=
-github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
-github.com/gobwas/pool v0.2.0 h1:QEmUOlnSjWtnpRGHF3SauEiOsy82Cup83Vf2LcMlnc8=
-github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
-github.com/gobwas/ws v1.0.3 h1:ZOigqf7iBxkA4jdQ3am7ATzdlOFp9YzA6NmuvEEZc9g=
-github.com/gobwas/ws v1.0.3/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
+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=
+github.com/gobwas/ws v1.0.4 h1:5eXU1CZhpQdq5kXbKb+sECH5Ia5KiO6CYzIzdlVx6Bs=
+github.com/gobwas/ws v1.0.4/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf h1:7+FW5aGwISbqUtkfmIpZJGRgNFg2ioYPvFaUxdqpDsg=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf/go.mod h1:RpwtwJQFrIEPstU94h88MWPXP2ektJZ8cZ0YntAmXiE=
-github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08 h1:V0an7KRw92wmJysvFvtqtKMAPmvS5O0jtB0nYo6t+gs=
-github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08/go.mod h1:dFWs1zEqDjFtnBXsd1vPOZaLsESovai349994nHx3e0=
-github.com/mailru/easyjson v0.7.0/go.mod h1:KAzv3t3aY1NaHWoQz1+4F1ccyAH66Jk7yos7ldAVICs=
-github.com/mailru/easyjson v0.7.1 h1:mdxE1MF9o53iCb2Ghj1VfWvh7ZOwHpnVG/xwXrV90U8=
-github.com/mailru/easyjson v0.7.1/go.mod h1:KAzv3t3aY1NaHWoQz1+4F1ccyAH66Jk7yos7ldAVICs=
+github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
+github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
+github.com/mailru/easyjson v0.7.6 h1:8yTIVnZgCoiM1TgqoeTl+LfU5Jg6/xL3QhGQnimLYnA=
+github.com/mailru/easyjson v0.7.6/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892 h1:6J+qramlHVLmiBOgRiBOnQkno8uprqG6YFFQTt6uYIw=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
+github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
+github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 go.bug.st/serial v1.0.0 h1:ogEPzrllCsnG00EqKRjeYvPRsO7NJW6DqykzkdD6E/k=
 go.bug.st/serial v1.0.0/go.mod h1:rpXPISGjuNjPTRTcMlxi9lN6LoIPxd1ixVjBd8aSk/Q=
+go.bug.st/serial v1.1.2 h1:6xDpbta8KJ+VLRTeM8ghhxXRMLE/Lr8h9iDKwydarAY=
+go.bug.st/serial v1.1.2/go.mod h1:VmYBeyJWp5BnJ0tw2NUJHZdJTGl2ecBGABHlzRK1knY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
@@ -39,8 +45,11 @@ golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 h1:ZBzSG/7F4eNKz2L3GE9o300RX0Az1Bw5HF7PDraD+qU=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200909081042-eff7692f9009/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210113181707-4bcb84eeeb78 h1:nVuTkr9L6Bq62qpUqKo/RnZCFfzDBL0bYo6w9OJUqZY=
+golang.org/x/sys v0.0.0-20210113181707-4bcb84eeeb78/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2 h1:0sfSpGSa544Fwnbot3Oxq/U6SXqjty6Jy/3wRhVS7ig=
 golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
@@ -48,5 +57,7 @@ golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbO
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9 h1:l2kTQOhqEoeDTK3ckUnwReOQwMPUmURMIdjJbeAuDT4=
-tinygo.org/x/go-llvm v0.0.0-20201104183921-570e7a6841d9/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20210308112806-9ef958b6bed4 h1:CMUHxVTb+UuUePuMf8vkWjZ3gTp9BBK91KrgOCwoNHs=
+tinygo.org/x/go-llvm v0.0.0-20210308112806-9ef958b6bed4/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20210325115028-e7b85195e81c h1:vn9IPshzYmzZis10UEVrsIBRv9FpykADw6M3/tHHROg=
+tinygo.org/x/go-llvm v0.0.0-20210325115028-e7b85195e81c/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=

goenv/goenv.go

@@ -142,10 +142,11 @@ 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 != "" {
-		// An explicitly set GOROOT always has preference.
-		return goroot
+		// Convert to the standard GOROOT being referenced, if it's a TinyGo cache.
+		return getStandardGoroot(goroot)
 	}
 
 	// Check for the location of the 'go' binary and base GOROOT on that.
@@ -170,8 +171,9 @@ func getGoroot() string {
 	switch runtime.GOOS {
 	case "linux":
 		candidates = []string{
-			"/usr/local/go", // manually installed
-			"/usr/lib/go",   // from the distribution
+			"/usr/local/go",     // manually installed
+			"/usr/lib/go",       // from the distribution
+			"/snap/go/current/", // installed using snap
 		}
 	case "darwin":
 		candidates = []string{
@@ -195,3 +197,21 @@ 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
+}

goenv/version.go

@@ -12,7 +12,7 @@ import (
 
 // Version of TinyGo.
 // Update this value before release of new version of software.
-const Version = "0.17.0-dev"
+const Version = "0.18.0-dev"
 
 // GetGorootVersion returns the major and minor version for a given GOROOT path.
 // If the goroot cannot be determined, (0, 0) is returned.

interp/compiler.go

@@ -25,6 +25,7 @@ type function struct {
 // 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
 }
 
@@ -135,6 +136,15 @@ func (r *runner) compileFunction(llvmFn llvm.Value) *function {
 				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()
@@ -337,7 +347,13 @@ func (r *runner) compileFunction(llvmFn llvm.Value) *function {
 				// This error is handled when actually trying to interpret this
 				// instruction (to not trigger on code that won't be executed).
 			}
-			bb.instructions = append(bb.instructions, inst)
+			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

interp/errors.go

@@ -11,19 +11,22 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
-var errLiteralToPointer = errors.New("interp: trying to convert literal value to pointer")
-
 // These errors are expected during normal execution and can be recovered from
 // by running the affected function at runtime instead of compile time.
 var (
-	errExpectedPointer        = errors.New("interp: trying to use an integer as a pointer (memory-mapped I/O?)")
+	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")
 )
 
+// 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 == errExpectedPointer || err == errUnsupportedInst || err == errUnsupportedRuntimeInst || err == errMapAlreadyCreated
+	return err == errIntegerAsPointer || err == errUnsupportedInst || err == errUnsupportedRuntimeInst || err == errMapAlreadyCreated
 }
 
 // ErrorLine is one line in a traceback. The position may be missing.

interp/interp.go

@@ -11,6 +11,12 @@ import (
 	"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
@@ -32,9 +38,7 @@ type runner struct {
 	callsExecuted uint64
 }
 
-// Run evaluates runtime.initAll function as much as possible at compile time.
-// Set debug to true if it should print output while running.
-func Run(mod llvm.Module, debug bool) error {
+func newRunner(mod llvm.Module, debug bool) *runner {
 	r := runner{
 		mod:           mod,
 		targetData:    llvm.NewTargetData(mod.DataLayout()),
@@ -47,6 +51,13 @@ func Run(mod llvm.Module, debug bool) error {
 	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
+}
+
+// Run evaluates runtime.initAll function as much as possible at compile time.
+// Set debug to true if it should print output while running.
+func Run(mod llvm.Module, debug bool) error {
+	r := newRunner(mod, debug)
 
 	initAll := mod.NamedFunction("runtime.initAll")
 	bb := initAll.EntryBasicBlock()
@@ -102,7 +113,7 @@ func Run(mod llvm.Module, debug bool) error {
 		if callErr != nil {
 			if isRecoverableError(callErr.Err) {
 				if r.debug {
-					fmt.Fprintln(os.Stderr, "not interpretring", r.pkgName, "because of error:", callErr.Err)
+					fmt.Fprintln(os.Stderr, "not interpreting", r.pkgName, "because of error:", callErr.Error())
 				}
 				mem.revert()
 				continue
@@ -117,7 +128,7 @@ func Run(mod llvm.Module, debug bool) error {
 	r.pkgName = ""
 
 	// Update all global variables in the LLVM module.
-	mem := memoryView{r: &r}
+	mem := memoryView{r: r}
 	for _, obj := range r.objects {
 		if obj.llvmGlobal.IsNil() {
 			continue
@@ -125,7 +136,34 @@ func Run(mod llvm.Module, debug bool) error {
 		if obj.buffer == nil {
 			continue
 		}
-		initializer := obj.buffer.toLLVMValue(obj.llvmGlobal.Type().ElementType(), &mem)
+		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
+		}
+		if err != nil {
+			return err
+		}
 		if checks && initializer.Type() != obj.llvmGlobal.Type().ElementType() {
 			panic("initializer type mismatch")
 		}
@@ -135,6 +173,87 @@ func Run(mod llvm.Module, debug bool) error {
 	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)")
+	}
+	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{})
+	}
+
+	// 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
+		}
+		return callErr
+	}
+	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 {

interp/interp_test.go

@@ -13,9 +13,9 @@ 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

interp/interpreter.go

@@ -33,6 +33,50 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 	lastBB := -1 // last basic block is undefined, only defined after a branch
 	var operands []value
 	for instIndex := 0; instIndex < len(bb.instructions); instIndex++ {
+		if instIndex == 0 {
+			// This is the start of a new basic block.
+			// There may be PHI nodes that need to be resolved. Resolve all PHI
+			// nodes before continuing with regular instructions.
+			// PHI nodes need to be treated specially because they can have a
+			// mutual dependency:
+			//   for.loop:
+			//     %a = phi i8 [ 1, %entry ], [ %b, %for.loop ]
+			//     %b = phi i8 [ 3, %entry ], [ %a, %for.loop ]
+			// If these PHI nodes are processed like a regular instruction, %a
+			// and %b are both 3 on the second iteration of the loop because %b
+			// loads the value of %a from the second iteration, while it should
+			// load the value from the previous iteration. The correct behavior
+			// is that these two values swap each others place on each
+			// iteration.
+			var phiValues []value
+			var phiIndices []int
+			for _, inst := range bb.phiNodes {
+				var result value
+				for i := 0; i < len(inst.operands); i += 2 {
+					if int(inst.operands[i].(literalValue).value.(uint32)) == lastBB {
+						incoming := inst.operands[i+1]
+						if local, ok := incoming.(localValue); ok {
+							result = locals[fn.locals[local.value]]
+						} else {
+							result = incoming
+						}
+						break
+					}
+				}
+				if r.debug {
+					fmt.Fprintln(os.Stderr, indent+"phi", inst.operands, "->", result)
+				}
+				if result == nil {
+					panic("could not find PHI input")
+				}
+				phiValues = append(phiValues, result)
+				phiIndices = append(phiIndices, inst.localIndex)
+			}
+			for i, value := range phiValues {
+				locals[phiIndices[i]] = value
+			}
+		}
+
 		inst := bb.instructions[instIndex]
 		operands = operands[:0]
 		isRuntimeInst := false
@@ -103,27 +147,24 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			default:
 				panic("unknown operands length")
 			}
-			break // continue with next block
-		case llvm.PHI:
-			var result value
-			for i := 0; i < len(inst.operands); i += 2 {
-				if int(inst.operands[i].(literalValue).value.(uint32)) == lastBB {
-					incoming := inst.operands[i+1]
-					if local, ok := incoming.(localValue); ok {
-						result = locals[fn.locals[local.value]]
-					} else {
-						result = incoming
-					}
+		case llvm.Switch:
+			// Switch statement: [value, defaultLabel, case0, label0, case1, label1, ...]
+			value := operands[0].Uint()
+			targetLabel := operands[1].Uint() // default label
+			// Do a lazy switch by iterating over all cases.
+			for i := 2; i < len(operands); i += 2 {
+				if value == operands[i].Uint() {
+					targetLabel = operands[i+1].Uint()
 					break
 				}
 			}
+			lastBB = currentBB
+			currentBB = int(targetLabel)
+			bb = fn.blocks[currentBB]
+			instIndex = -1 // start at 0 the next cycle
 			if r.debug {
-				fmt.Fprintln(os.Stderr, indent+"phi", inst.operands, "->", result)
+				fmt.Fprintln(os.Stderr, indent+"switch", operands, "->", currentBB)
 			}
-			if result == nil {
-				panic("could not find PHI input")
-			}
-			locals[inst.localIndex] = result
 		case llvm.Select:
 			// Select is much like a ternary operator: it picks a result from
 			// the second and third operand based on the boolean first operand.
@@ -155,17 +196,17 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				// which case this call won't even get to this point but will
 				// already be emitted in initAll.
 				continue
-			case callFn.name == "(reflect.Type).Elem" || strings.HasPrefix(callFn.name, "runtime.print") || callFn.name == "runtime._panic" || callFn.name == "runtime.hashmapGet":
+			case strings.HasPrefix(callFn.name, "runtime.print") || callFn.name == "runtime._panic" || callFn.name == "runtime.hashmapGet" || callFn.name == "os.runtime_args":
 				// These functions should be run at runtime. Specifically:
-				//   * (reflect.Type).Elem is a special function. It should
-				//     eventually be interpreted, but fall back to a runtime call
-				//     for now.
 				//   * Print and panic functions are best emitted directly without
 				//     interpreting them, otherwise we get a ton of putchar (etc.)
 				//     calls.
 				//   * runtime.hashmapGet tries to access the map value directly.
 				//     This is not possible as the map value is treated as a special
 				//     kind of object in this package.
+				//   * os.runtime_args reads globals that are initialized outside
+				//     the view of the interp package so it always needs to be run
+				//     at runtime.
 				err := r.runAtRuntime(fn, inst, locals, &mem, indent)
 				if err != nil {
 					return nil, mem, err
@@ -280,26 +321,58 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				copy(dstBuf.buf[dst.offset():dst.offset()+nBytes], srcBuf.buf[src.offset():])
 				dstObj.buffer = dstBuf
 				mem.put(dst.index(), dstObj)
+			case callFn.name == "(reflect.rawType).elem":
+				if r.debug {
+					fmt.Fprintln(os.Stderr, indent+"call (reflect.rawType).elem:", operands[1:])
+				}
+				// Extract the type code global from the first parameter.
+				typecodeIDPtrToInt, err := operands[1].toLLVMValue(inst.llvmInst.Operand(0).Type(), &mem)
+				if err != nil {
+					return nil, mem, r.errorAt(inst, err)
+				}
+				typecodeID := typecodeIDPtrToInt.Operand(0)
+
+				// Get the type class.
+				// See also: getClassAndValueFromTypeCode in transform/reflect.go.
+				typecodeName := typecodeID.Name()
+				const prefix = "reflect/types.type:"
+				if !strings.HasPrefix(typecodeName, prefix) {
+					panic("unexpected typecode name: " + typecodeName)
+				}
+				id := typecodeName[len(prefix):]
+				class := id[:strings.IndexByte(id, ':')]
+				value := id[len(class)+1:]
+				if class == "named" {
+					// Get the underlying type.
+					class = value[:strings.IndexByte(value, ':')]
+					value = value[len(class)+1:]
+				}
+
+				// Elem() is only valid for certain type classes.
+				switch class {
+				case "chan", "pointer", "slice", "array":
+					elementType := llvm.ConstExtractValue(typecodeID.Initializer(), []uint32{0})
+					uintptrType := r.mod.Context().IntType(int(mem.r.pointerSize) * 8)
+					locals[inst.localIndex] = r.getValue(llvm.ConstPtrToInt(elementType, uintptrType))
+				default:
+					return nil, mem, r.errorAt(inst, fmt.Errorf("(reflect.Type).Elem() called on %s type", class))
+				}
 			case callFn.name == "runtime.typeAssert":
 				// This function must be implemented manually as it is normally
 				// implemented by the interface lowering pass.
 				if r.debug {
 					fmt.Fprintln(os.Stderr, indent+"typeassert:", operands[1:])
 				}
-				typeInInterfacePtr, err := operands[1].asPointer(r)
+				assertedType, err := operands[2].toLLVMValue(inst.llvmInst.Operand(1).Type(), &mem)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				actualType, err := mem.load(typeInInterfacePtr, r.pointerSize).asPointer(r)
+				actualTypePtrToInt, err := operands[1].toLLVMValue(inst.llvmInst.Operand(0).Type(), &mem)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				assertedType, err := operands[2].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				result := assertedType.asRawValue(r).equal(actualType.asRawValue(r))
-				if result {
+				actualType := actualTypePtrToInt.Operand(0)
+				if strings.TrimPrefix(actualType.Name(), "reflect/types.type:") == strings.TrimPrefix(assertedType.Name(), "reflect/types.typeid:") {
 					locals[inst.localIndex] = literalValue{uint8(1)}
 				} else {
 					locals[inst.localIndex] = literalValue{uint8(0)}
@@ -310,11 +383,11 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				}
 
 				// Load various values for the interface implements check below.
-				typeInInterfacePtr, err := operands[1].asPointer(r)
+				typecodePtr, err := operands[1].asPointer(r)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				methodSetPtr, err := mem.load(typeInInterfacePtr.addOffset(r.pointerSize), r.pointerSize).asPointer(r)
+				methodSetPtr, err := mem.load(typecodePtr.addOffset(r.pointerSize*2), r.pointerSize).asPointer(r)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
@@ -349,74 +422,43 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				}
 				// If assertOk is still 1, the assertion succeeded.
 				locals[inst.localIndex] = literalValue{assertOk}
-			case callFn.name == "runtime.hashmapMake":
-				// Create a new map.
-				hashmapPointerType := inst.llvmInst.Type()
-				keySize := uint32(operands[1].Uint())
-				valueSize := uint32(operands[2].Uint())
-				m := newMapValue(r, hashmapPointerType, keySize, valueSize)
-				alloc := object{
-					llvmType:   hashmapPointerType,
-					globalName: r.pkgName + "$map",
-					buffer:     m,
-					size:       m.len(r),
+			case callFn.name == "runtime.interfaceMethod":
+				// This builtin returns the function (which may be a thunk) to
+				// invoke a method on an interface. It does not call the method.
+				if r.debug {
+					fmt.Fprintln(os.Stderr, indent+"interface method:", operands[1:])
 				}
-				index := len(r.objects)
-				r.objects = append(r.objects, alloc)
 
-				// Create a pointer to this map. Maps are reference types, so
-				// are implemented as pointers.
-				ptr := newPointerValue(r, index, 0)
-				if r.debug {
-					fmt.Fprintln(os.Stderr, indent+"runtime.hashmapMake:", keySize, valueSize, "->", ptr)
-				}
-				locals[inst.localIndex] = ptr
-			case callFn.name == "runtime.hashmapBinarySet":
-				// Do a mapassign operation with a binary key (that is, without
-				// a string key).
-				if r.debug {
-					fmt.Fprintln(os.Stderr, indent+"runtime.hashmapBinarySet:", operands[1:])
-				}
-				mapPtr, err := operands[1].asPointer(r)
+				// Load the first param, which is the type code (ptrtoint of the
+				// type code global).
+				typecodeIDPtrToInt, err := operands[1].toLLVMValue(inst.llvmInst.Operand(0).Type(), &mem)
 				if err != nil {
 					return nil, mem, r.errorAt(inst, err)
 				}
-				m := mem.getWritable(mapPtr.index()).buffer.(*mapValue)
-				keyPtr, err := operands[2].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
+				typecodeID := typecodeIDPtrToInt.Operand(0).Initializer()
+
+				// Load the method set, which is part of the typecodeID object.
+				methodSet := llvm.ConstExtractValue(typecodeID, []uint32{2}).Operand(0).Initializer()
+
+				// We don't need to load the interface method set.
+
+				// Load the signature of the to-be-called function.
+				signature := inst.llvmInst.Operand(2)
+
+				// Iterate through all methods, looking for the one method that
+				// should be returned.
+				numMethods := methodSet.Type().ArrayLength()
+				var method llvm.Value
+				for i := 0; i < numMethods; i++ {
+					methodSignature := llvm.ConstExtractValue(methodSet, []uint32{uint32(i), 0})
+					if methodSignature == signature {
+						method = llvm.ConstExtractValue(methodSet, []uint32{uint32(i), 1}).Operand(0)
+					}
 				}
-				valuePtr, err := operands[3].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				err = m.putBinary(&mem, keyPtr, valuePtr)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-			case callFn.name == "runtime.hashmapStringSet":
-				// Do a mapassign operation with a string key.
-				if r.debug {
-					fmt.Fprintln(os.Stderr, indent+"runtime.hashmapBinarySet:", operands[1:])
-				}
-				mapPtr, err := operands[1].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				m := mem.getWritable(mapPtr.index()).buffer.(*mapValue)
-				stringPtr, err := operands[2].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				stringLen := operands[3].Uint()
-				valuePtr, err := operands[4].asPointer(r)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
-				}
-				err = m.putString(&mem, stringPtr, stringLen, valuePtr)
-				if err != nil {
-					return nil, mem, r.errorAt(inst, err)
+				if method.IsNil() {
+					return nil, mem, r.errorAt(inst, errors.New("could not find method: "+signature.Name()))
 				}
+				locals[inst.localIndex] = r.getValue(method)
 			default:
 				if len(callFn.blocks) == 0 {
 					// Call to a function declaration without a definition
@@ -482,6 +524,13 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				continue
 			}
 			result := mem.load(ptr, uint32(size))
+			if result == nil {
+				err := r.runAtRuntime(fn, inst, locals, &mem, indent)
+				if err != nil {
+					return nil, mem, err
+				}
+				continue
+			}
 			if r.debug {
 				fmt.Fprintln(os.Stderr, indent+"load:", ptr, "->", result)
 			}
@@ -504,7 +553,14 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			if r.debug {
 				fmt.Fprintln(os.Stderr, indent+"store:", val, ptr)
 			}
-			mem.store(val, ptr)
+			ok := mem.store(val, ptr)
+			if !ok {
+				// Could not store the value, do it at runtime.
+				err := r.runAtRuntime(fn, inst, locals, &mem, indent)
+				if err != nil {
+					return nil, mem, err
+				}
+			}
 		case llvm.Alloca:
 			// Alloca normally allocates some stack memory. In the interpreter,
 			// it allocates a global instead.
@@ -550,7 +606,22 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 			}
 			ptr, err := operands[0].asPointer(r)
 			if err != nil {
-				return nil, mem, r.errorAt(inst, err)
+				if err != errIntegerAsPointer {
+					return nil, mem, r.errorAt(inst, err)
+				}
+				// GEP on fixed pointer value (for example, memory-mapped I/O).
+				ptrValue := operands[0].Uint() + offset
+				switch operands[0].len(r) {
+				case 8:
+					locals[inst.localIndex] = literalValue{uint64(ptrValue)}
+				case 4:
+					locals[inst.localIndex] = literalValue{uint32(ptrValue)}
+				case 2:
+					locals[inst.localIndex] = literalValue{uint16(ptrValue)}
+				default:
+					panic("pointer operand is not of a known pointer size")
+				}
+				continue
 			}
 			ptr = ptr.addOffset(uint32(offset))
 			locals[inst.localIndex] = ptr
@@ -821,7 +892,11 @@ func (r *runner) runAtRuntime(fn *function, inst instruction, locals []value, me
 	for i := 0; i < numOperands; i++ {
 		operand := inst.llvmInst.Operand(i)
 		if !operand.IsAInstruction().IsNil() || !operand.IsAArgument().IsNil() {
-			operand = locals[fn.locals[operand]].toLLVMValue(operand.Type(), mem)
+			var err error
+			operand, err = locals[fn.locals[operand]].toLLVMValue(operand.Type(), mem)
+			if err != nil {
+				return r.errorAt(inst, err)
+			}
 		}
 		operands[i] = operand
 	}

interp/memory.go

@@ -259,12 +259,17 @@ func (mv *memoryView) put(index uint32, obj object) {
 	mv.objects[index] = obj
 }
 
-// Load the value behind the given pointer.
+// Load the value behind the given pointer. Returns nil if the pointer points to
+// an external global.
 func (mv *memoryView) load(p pointerValue, size uint32) value {
 	if checks && mv.hasExternalStore(p) {
 		panic("interp: load from object with external store")
 	}
 	obj := mv.get(p.index())
+	if obj.buffer == nil {
+		// External global, return nil.
+		return nil
+	}
 	if p.offset() == 0 && size == obj.size {
 		return obj.buffer.clone()
 	}
@@ -280,12 +285,17 @@ func (mv *memoryView) load(p pointerValue, size uint32) value {
 
 // Store to the value behind the given pointer. This overwrites the value in the
 // memory view, so that the changed value is discarded when the memory view is
-// reverted.
-func (mv *memoryView) store(v value, p pointerValue) {
+// reverted. Returns true on success, false if the object to store to is
+// external.
+func (mv *memoryView) store(v value, p pointerValue) bool {
 	if checks && mv.hasExternalLoadOrStore(p) {
 		panic("interp: store to object with external load/store")
 	}
 	obj := mv.get(p.index())
+	if obj.buffer == nil {
+		// External global, return false (for a failure).
+		return false
+	}
 	if checks && p.offset()+v.len(mv.r) > obj.size {
 		panic("interp: store out of bounds")
 	}
@@ -301,6 +311,7 @@ func (mv *memoryView) store(v value, p pointerValue) {
 		}
 	}
 	mv.put(p.index(), obj)
+	return true // success
 }
 
 // value is some sort of value, comparable to a LLVM constant. It can be
@@ -314,7 +325,7 @@ type value interface {
 	asRawValue(*runner) rawValue
 	Uint() uint64
 	Int() int64
-	toLLVMValue(llvm.Type, *memoryView) llvm.Value
+	toLLVMValue(llvm.Type, *memoryView) (llvm.Value, error)
 	String() string
 }
 
@@ -348,7 +359,7 @@ func (v literalValue) clone() value {
 }
 
 func (v literalValue) asPointer(r *runner) (pointerValue, error) {
-	return pointerValue{}, errLiteralToPointer
+	return pointerValue{}, errIntegerAsPointer
 }
 
 func (v literalValue) asRawValue(r *runner) rawValue {
@@ -405,25 +416,25 @@ func (v literalValue) Int() int64 {
 	}
 }
 
-func (v literalValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
+func (v literalValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value, error) {
 	switch llvmType.TypeKind() {
 	case llvm.IntegerTypeKind:
 		switch value := v.value.(type) {
 		case uint64:
-			return llvm.ConstInt(llvmType, value, false)
+			return llvm.ConstInt(llvmType, value, false), nil
 		case uint32:
-			return llvm.ConstInt(llvmType, uint64(value), false)
+			return llvm.ConstInt(llvmType, uint64(value), false), nil
 		case uint16:
-			return llvm.ConstInt(llvmType, uint64(value), false)
+			return llvm.ConstInt(llvmType, uint64(value), false), nil
 		case uint8:
-			return llvm.ConstInt(llvmType, uint64(value), false)
+			return llvm.ConstInt(llvmType, uint64(value), false), nil
 		default:
-			panic("inpterp: unknown literal type")
+			return llvm.Value{}, errors.New("interp: unknown literal type")
 		}
 	case llvm.DoubleTypeKind:
-		return llvm.ConstFloat(llvmType, math.Float64frombits(v.value.(uint64)))
+		return llvm.ConstFloat(llvmType, math.Float64frombits(v.value.(uint64))), nil
 	case llvm.FloatTypeKind:
-		return llvm.ConstFloat(llvmType, float64(math.Float32frombits(v.value.(uint32))))
+		return llvm.ConstFloat(llvmType, float64(math.Float32frombits(v.value.(uint32)))), nil
 	default:
 		return v.asRawValue(mem.r).toLLVMValue(llvmType, mem)
 	}
@@ -507,7 +518,7 @@ func (v pointerValue) llvmValue(mem *memoryView) llvm.Value {
 // toLLVMValue returns the LLVM value for this pointer, which may be a GEP or
 // bitcast. The llvm.Type parameter is optional, if omitted the pointer type may
 // be different than expected.
-func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
+func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value, error) {
 	// Obtain the llvmValue, creating it if it doesn't exist yet.
 	llvmValue := v.llvmValue(mem)
 	if llvmValue.IsNil() {
@@ -518,7 +529,10 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 		if obj.llvmType.IsNil() {
 			// Create an initializer without knowing the global type.
 			// This is probably the result of a runtime.alloc call.
-			initializer := obj.buffer.asRawValue(mem.r).rawLLVMValue(mem)
+			initializer, err := obj.buffer.asRawValue(mem.r).rawLLVMValue(mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 			globalType := initializer.Type()
 			llvmValue = llvm.AddGlobal(mem.r.mod, globalType, obj.globalName)
 			llvmValue.SetInitializer(initializer)
@@ -537,9 +551,12 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 			// Set the initializer for the global. Do this after creation to avoid
 			// infinite recursion between creating the global and creating the
 			// contents of the global (if the global contains itself).
-			initializer := obj.buffer.toLLVMValue(globalType, mem)
+			initializer, err := obj.buffer.toLLVMValue(globalType, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 			if checks && initializer.Type() != globalType {
-				panic("allocated value does not match allocated type")
+				return llvm.Value{}, errors.New("interp: allocated value does not match allocated type")
 			}
 			llvmValue.SetInitializer(initializer)
 		}
@@ -552,7 +569,7 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 	}
 
 	if llvmType.IsNil() {
-		return llvmValue
+		return llvmValue, nil
 	}
 
 	if llvmType.TypeKind() != llvm.PointerTypeKind {
@@ -564,7 +581,7 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 		// This can be worked around by simply converting to a raw value,
 		// rawValue knows how to create such structs.
 		if v.offset() != 0 {
-			panic("offset set without known pointer type")
+			return llvm.Value{}, errors.New("interp: offset set without known pointer type")
 		}
 		return v.asRawValue(mem.r).toLLVMValue(llvmType, mem)
 	}
@@ -575,14 +592,14 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 		if v.offset() != 0 {
 			// This should never happen, if offset is non-zero, the types
 			// shouldn't match.
-			panic("offset set while there is no way to convert the type")
+			return llvm.Value{}, errors.New("interp: offset set while there is no way to convert the type")
 		}
-		return llvmValue
+		return llvmValue, nil
 	}
 
 	if v.offset() == 0 {
 		// Offset is zero, so we can just bitcast to get a correct pointer.
-		return llvm.ConstBitCast(llvmValue, llvmType)
+		return llvm.ConstBitCast(llvmValue, llvmType), nil
 	}
 
 	// We need to make a constant GEP for pointer arithmetic.
@@ -606,11 +623,11 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 			offset -= int64(mem.r.targetData.ElementOffset(objectElementType, element))
 			objectElementType = objectElementType.StructElementTypes()[element]
 		default:
-			panic("pointer index with something other than a struct or array?")
+			return llvm.Value{}, errors.New("interp: pointer index with something other than a struct or array?")
 		}
 	}
 	if offset < 0 {
-		panic("offset has somehow gone negative, this should be impossible")
+		return llvm.Value{}, errors.New("interp: offset has somehow gone negative, this should be impossible")
 	}
 
 	// Finally do the gep, using the above computed indices.
@@ -618,283 +635,9 @@ func (v pointerValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Valu
 	// the bits of the pointer are now correct, just not the type).
 	gep := llvm.ConstInBoundsGEP(llvmValue, indices)
 	if gep.Type() != llvmType {
-		return llvm.ConstBitCast(gep, llvmType)
+		return llvm.ConstBitCast(gep, llvmType), nil
 	}
-	return gep
-}
-
-// mapValue implements a Go map which is created at compile time and stored as a
-// global variable.
-// The value itself is only used as part of an object (object.buffer). Maps are
-// reference types aka pointers, so it can only be used as a pointerValue, not
-// directly.
-type mapValue struct {
-	r           *runner
-	pkgName     string
-	size        uint32 // byte size of runtime.hashmap
-	hashmap     llvm.Value
-	keyIsString bool
-	keys        []interface{} // either rawValue (for binary key) or mapStringKey (for string key)
-	values      []rawValue
-	keySize     uint32
-	valueSize   uint32
-}
-
-type mapStringKey struct {
-	buf  pointerValue
-	size uint64
-	data []uint64
-}
-
-func newMapValue(r *runner, hashmapPointerType llvm.Type, keySize, valueSize uint32) *mapValue {
-	size := uint32(r.targetData.TypeAllocSize(hashmapPointerType.ElementType()))
-	return &mapValue{
-		r:         r,
-		pkgName:   r.pkgName,
-		size:      size,
-		keySize:   keySize,
-		valueSize: valueSize,
-	}
-}
-
-func (v *mapValue) len(r *runner) uint32 {
-	return v.size
-}
-
-func (v *mapValue) clone() value {
-	// Return a copy of mapValue.
-	clone := *v
-	clone.keys = append([]interface{}{}, clone.keys...)
-	clone.values = append([]rawValue{}, clone.values...)
-	return &clone
-}
-
-func (v *mapValue) asPointer(r *runner) (pointerValue, error) {
-	panic("interp: mapValue.asPointer")
-}
-
-func (v *mapValue) asRawValue(r *runner) rawValue {
-	panic("interp: mapValue.asRawValue")
-}
-
-func (v *mapValue) Uint() uint64 {
-	panic("interp: mapValue.Uint")
-}
-
-func (v *mapValue) Int() int64 {
-	panic("interp: mapValue.Int")
-}
-
-// Temporary struct to collect data before turning this into a hashmap bucket
-// LLVM value.
-type mapBucket struct {
-	m       *mapValue
-	tophash [8]uint8
-	keys    []rawValue // can have up to 8 keys
-	values  []rawValue // can have up to 8 values, len(keys) == len(values)
-}
-
-// create returns a (pointer to a) buffer structurally equivalent to
-// runtime.hashmapBucket.
-func (b *mapBucket) create(ctx llvm.Context, nextBucket llvm.Value, mem *memoryView) llvm.Value {
-	// Create tophash array.
-	int8Type := ctx.Int8Type()
-	tophashValues := make([]llvm.Value, 8)
-	for i := range tophashValues {
-		tophashValues[i] = llvm.ConstInt(int8Type, uint64(b.tophash[i]), false)
-	}
-	tophash := llvm.ConstArray(int8Type, tophashValues)
-
-	// Create next pointer (if not set).
-	if nextBucket.IsNil() {
-		nextBucket = llvm.ConstNull(llvm.PointerType(int8Type, 0))
-	}
-
-	// Create data for keys.
-	var keyValues []llvm.Value
-	for _, key := range b.keys {
-		keyValues = append(keyValues, key.rawLLVMValue(mem))
-	}
-	if len(b.keys) < 8 {
-		keyValues = append(keyValues, llvm.ConstNull(llvm.ArrayType(int8Type, int(b.m.keySize)*(8-len(b.keys)))))
-	}
-	keyValue := ctx.ConstStruct(keyValues, false)
-	if checks && uint32(b.m.r.targetData.TypeAllocSize(keyValue.Type())) != b.m.keySize*8 {
-		panic("key size invalid")
-	}
-
-	// Create data for values.
-	var valueValues []llvm.Value
-	for _, value := range b.values {
-		valueValues = append(valueValues, value.rawLLVMValue(mem))
-	}
-	if len(b.values) < 8 {
-		valueValues = append(valueValues, llvm.ConstNull(llvm.ArrayType(int8Type, int(b.m.valueSize)*(8-len(b.values)))))
-	}
-	valueValue := ctx.ConstStruct(valueValues, false)
-	if checks && uint32(b.m.r.targetData.TypeAllocSize(valueValue.Type())) != b.m.valueSize*8 {
-		panic("value size invalid")
-	}
-
-	// Create the bucket.
-	bucketInitializer := ctx.ConstStruct([]llvm.Value{
-		tophash,
-		nextBucket,
-		keyValue,
-		valueValue,
-	}, false)
-	bucket := llvm.AddGlobal(b.m.r.mod, bucketInitializer.Type(), b.m.pkgName+"$mapbucket")
-	bucket.SetInitializer(bucketInitializer)
-	bucket.SetLinkage(llvm.InternalLinkage)
-	bucket.SetUnnamedAddr(true)
-	return bucket
-}
-
-func (v *mapValue) toLLVMValue(hashmapType llvm.Type, mem *memoryView) llvm.Value {
-	if !v.hashmap.IsNil() {
-		return v.hashmap
-	}
-
-	// Create a slice of buckets with all the keys and values in the hashmap.
-	var buckets []*mapBucket
-	var bucket *mapBucket
-	for i, key := range v.keys {
-		var data []uint64
-		var keyValue rawValue
-		switch key := key.(type) {
-		case mapStringKey:
-			data = key.data
-			keyValue = newRawValue(v.keySize)
-			// runtime._string is {ptr, length}
-			for i := uint32(0); i < v.keySize/2; i++ {
-				keyValue.buf[i] = key.buf.pointer
-			}
-			copy(keyValue.buf[v.keySize/2:], literalValue{key.size}.asRawValue(v.r).buf)
-		case rawValue:
-			if key.hasPointer() {
-				panic("todo: map key with pointer")
-			}
-			data = key.buf
-			keyValue = key
-		default:
-			panic("unknown map key type")
-		}
-		buf := make([]byte, len(data))
-		for i, p := range data {
-			buf[i] = byte(p)
-		}
-		hash := v.hash(buf)
-
-		if i%8 == 0 {
-			bucket = &mapBucket{m: v}
-			buckets = append(buckets, bucket)
-		}
-		bucket.tophash[i%8] = v.topHash(hash)
-		bucket.keys = append(bucket.keys, keyValue)
-		bucket.values = append(bucket.values, v.values[i])
-	}
-
-	// Convert these buckets into LLVM global variables.
-	ctx := v.r.mod.Context()
-	var nextBucket llvm.Value
-	for i := len(buckets) - 1; i >= 0; i-- {
-		bucket = buckets[i]
-		bucketValue := bucket.create(ctx, nextBucket, mem)
-		nextBucket = bucketValue
-	}
-	firstBucket := nextBucket
-	if firstBucket.IsNil() {
-		firstBucket = llvm.ConstNull(mem.r.i8ptrType)
-	} else {
-		firstBucket = llvm.ConstBitCast(firstBucket, mem.r.i8ptrType)
-	}
-
-	// Create the hashmap itself, pointing to these buckets.
-	hashmapPointerType := llvm.PointerType(hashmapType, 0)
-	hashmap := llvm.ConstNamedStruct(hashmapType, []llvm.Value{
-		llvm.ConstPointerNull(hashmapPointerType), // next
-		firstBucket, // 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
-	})
-
-	v.hashmap = hashmap
-	return v.hashmap
-}
-
-// putString does a map assign operation, assuming that the map is of type
-// map[string]T.
-func (v *mapValue) putString(mem *memoryView, stringBuf pointerValue, stringLen uint64, valuePtr pointerValue) error {
-	if !v.hashmap.IsNil() {
-		return errMapAlreadyCreated
-	}
-
-	value := mem.load(valuePtr, v.valueSize)
-	stringValue := mem.load(stringBuf, uint32(stringLen)).asRawValue(v.r)
-	if stringValue.hasPointer() {
-		panic("interp: string contains pointer")
-	}
-
-	// TODO: avoid duplicate keys
-	v.keys = append(v.keys, mapStringKey{stringBuf, stringLen, stringValue.buf})
-	v.values = append(v.values, value.asRawValue(v.r))
-	v.keyIsString = true
-
-	return nil
-}
-
-// putBinary does a map assign operation for binary data (e.g. [3]int etc). The
-// key must not contain pointer values.
-func (v *mapValue) putBinary(mem *memoryView, keyPtr, valuePtr pointerValue) error {
-	if !v.hashmap.IsNil() {
-		return errMapAlreadyCreated
-	}
-
-	key := mem.load(keyPtr, v.keySize)
-	value := mem.load(valuePtr, v.valueSize)
-
-	// Sanity checks.
-	if v.keySize != key.len(mem.r) || v.valueSize != value.len(mem.r) {
-		// This is a bug (not unhandled input), so panic.
-		panic("interp: key or value size mismatch")
-	}
-	if v.keyIsString {
-		panic("cannot put binary keys in string map")
-	}
-
-	// TODO: avoid duplicate keys
-	v.keys = append(v.keys, key.asRawValue(v.r))
-	v.values = append(v.values, value.asRawValue(v.r))
-
-	return nil
-}
-
-// Get FNV-1a hash of this string.
-//
-// https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash
-func (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++
-	}
-	return tophash
-}
-
-func (v *mapValue) String() string {
-	return "<map keySize=" + strconv.Itoa(int(v.keySize)) + " valueSize=" + strconv.Itoa(int(v.valueSize)) + ">"
+	return gep, nil
 }
 
 // rawValue is a raw memory buffer that can store either pointers or regular
@@ -949,7 +692,7 @@ func (v rawValue) clone() value {
 func (v rawValue) asPointer(r *runner) (pointerValue, error) {
 	if v.buf[0] <= 255 {
 		// Probably a null pointer or memory-mapped I/O.
-		return pointerValue{}, errExpectedPointer
+		return pointerValue{}, errIntegerAsPointer
 	}
 	return pointerValue{v.buf[0]}, nil
 }
@@ -1018,7 +761,7 @@ func (v rawValue) equal(rhs rawValue) bool {
 // goes. The resulting value does not have a specified type, but it will be the
 // same size and have the same bytes if it was created with a provided LLVM type
 // (through toLLVMValue).
-func (v rawValue) rawLLVMValue(mem *memoryView) llvm.Value {
+func (v rawValue) rawLLVMValue(mem *memoryView) (llvm.Value, error) {
 	var structFields []llvm.Value
 	ctx := mem.r.mod.Context()
 	int8Type := ctx.Int8Type()
@@ -1042,13 +785,16 @@ func (v rawValue) rawLLVMValue(mem *memoryView) llvm.Value {
 	for i := uint32(0); i < uint32(len(v.buf)); {
 		if v.buf[i] > 255 {
 			addBytes()
-			field := pointerValue{v.buf[i]}.toLLVMValue(llvm.Type{}, mem)
+			field, err := pointerValue{v.buf[i]}.toLLVMValue(llvm.Type{}, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 			elementType := field.Type().ElementType()
 			if elementType.TypeKind() == llvm.StructTypeKind {
 				// There are some special pointer types that should be used as a
 				// ptrtoint, so that they can be used in certain optimizations.
 				name := elementType.StructName()
-				if name == "runtime.typeInInterface" || name == "runtime.funcValueWithSignature" {
+				if name == "runtime.typecodeID" || name == "runtime.funcValueWithSignature" {
 					uintptrType := ctx.IntType(int(mem.r.pointerSize) * 8)
 					field = llvm.ConstPtrToInt(field, uintptrType)
 				}
@@ -1065,12 +811,12 @@ func (v rawValue) rawLLVMValue(mem *memoryView) llvm.Value {
 
 	// Return the created data.
 	if len(structFields) == 1 {
-		return structFields[0]
+		return structFields[0], nil
 	}
-	return ctx.ConstStruct(structFields, false)
+	return ctx.ConstStruct(structFields, false), nil
 }
 
-func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
+func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value, error) {
 	isZero := true
 	for _, p := range v.buf {
 		if p != 0 {
@@ -1079,7 +825,7 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 		}
 	}
 	if isZero {
-		return llvm.ConstNull(llvmType)
+		return llvm.ConstNull(llvmType), nil
 	}
 	switch llvmType.TypeKind() {
 	case llvm.IntegerTypeKind:
@@ -1088,7 +834,17 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 			if err != nil {
 				panic(err)
 			}
-			return llvm.ConstPtrToInt(ptr.toLLVMValue(llvm.Type{}, mem), llvmType)
+			if checks && mem.r.targetData.TypeAllocSize(llvmType) != mem.r.targetData.TypeAllocSize(mem.r.i8ptrType) {
+				// Probably trying to serialize a pointer to a byte array,
+				// perhaps as a result of rawLLVMValue() in a previous interp
+				// run.
+				return llvm.Value{}, errInvalidPtrToIntSize
+			}
+			v, err := ptr.toLLVMValue(llvm.Type{}, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
+			return llvm.ConstPtrToInt(v, llvmType), nil
 		}
 		var n uint64
 		switch llvmType.IntTypeWidth() {
@@ -1108,7 +864,7 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 		default:
 			panic("unknown integer size")
 		}
-		return llvm.ConstInt(llvmType, n, false)
+		return llvm.ConstInt(llvmType, n, false), nil
 	case llvm.StructTypeKind:
 		fieldTypes := llvmType.StructElementTypes()
 		fields := make([]llvm.Value, len(fieldTypes))
@@ -1117,12 +873,16 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 			field := rawValue{
 				buf: v.buf[offset:],
 			}
-			fields[i] = field.toLLVMValue(fieldType, mem)
+			var err error
+			fields[i], err = field.toLLVMValue(fieldType, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 		}
 		if llvmType.StructName() != "" {
-			return llvm.ConstNamedStruct(llvmType, fields)
+			return llvm.ConstNamedStruct(llvmType, fields), nil
 		}
-		return llvmType.Context().ConstStruct(fields, false)
+		return llvmType.Context().ConstStruct(fields, false), nil
 	case llvm.ArrayTypeKind:
 		numElements := llvmType.ArrayLength()
 		childType := llvmType.ElementType()
@@ -1133,27 +893,34 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 			field := rawValue{
 				buf: v.buf[offset:],
 			}
-			fields[i] = field.toLLVMValue(childType, mem)
+			var err error
+			fields[i], err = field.toLLVMValue(childType, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 			if checks && fields[i].Type() != childType {
 				panic("child type doesn't match")
 			}
 		}
-		return llvm.ConstArray(childType, fields)
+		return llvm.ConstArray(childType, fields), nil
 	case llvm.PointerTypeKind:
 		if v.buf[0] > 255 {
 			// This is a regular pointer.
-			llvmValue := pointerValue{v.buf[0]}.toLLVMValue(llvm.Type{}, mem)
+			llvmValue, err := pointerValue{v.buf[0]}.toLLVMValue(llvm.Type{}, mem)
+			if err != nil {
+				return llvm.Value{}, err
+			}
 			if llvmValue.Type() != llvmType {
 				llvmValue = llvm.ConstBitCast(llvmValue, llvmType)
 			}
-			return llvmValue
+			return llvmValue, nil
 		}
 		// This is either a null pointer or a raw pointer for memory-mapped I/O
 		// (such as 0xe000ed00).
 		ptr := rawValue{v.buf[:mem.r.pointerSize]}.Uint()
 		if ptr == 0 {
 			// Null pointer.
-			return llvm.ConstNull(llvmType)
+			return llvm.ConstNull(llvmType), nil
 		}
 		var ptrValue llvm.Value // the underlying int
 		switch mem.r.pointerSize {
@@ -1164,19 +931,19 @@ func (v rawValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
 		case 2:
 			ptrValue = llvm.ConstInt(llvmType.Context().Int16Type(), ptr, false)
 		default:
-			panic("unknown pointer size")
+			return llvm.Value{}, errors.New("interp: unknown pointer size")
 		}
-		return llvm.ConstIntToPtr(ptrValue, llvmType)
+		return llvm.ConstIntToPtr(ptrValue, llvmType), nil
 	case llvm.DoubleTypeKind:
 		b := rawValue{v.buf[:8]}.Uint()
 		f := math.Float64frombits(b)
-		return llvm.ConstFloat(llvmType, f)
+		return llvm.ConstFloat(llvmType, f), nil
 	case llvm.FloatTypeKind:
 		b := uint32(rawValue{v.buf[:4]}.Uint())
 		f := math.Float32frombits(b)
-		return llvm.ConstFloat(llvmType, float64(f))
+		return llvm.ConstFloat(llvmType, float64(f)), nil
 	default:
-		panic("todo: raw value to LLVM value: " + llvmType.String())
+		return llvm.Value{}, errors.New("interp: todo: raw value to LLVM value: " + llvmType.String())
 	}
 }
 
@@ -1365,8 +1132,8 @@ func (v localValue) Int() int64 {
 	panic("interp: localValue.Int")
 }
 
-func (v localValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) llvm.Value {
-	return v.value
+func (v localValue) toLLVMValue(llvmType llvm.Type, mem *memoryView) (llvm.Value, error) {
+	return v.value, nil
 }
 
 func (r *runner) getValue(llvmValue llvm.Value) value {

interp/testdata/basic.ll

@@ -65,6 +65,12 @@ entry:
   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)
+
   ret void
 }
 
@@ -87,3 +93,22 @@ 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
+}

interp/testdata/basic.out.ll

@@ -25,6 +25,8 @@ entry:
   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)
   ret void
 }
 
@@ -44,3 +46,24 @@ 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
+}

interp/testdata/interface.ll

@@ -1,17 +1,16 @@
 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.typecodeID = type { %runtime.typecodeID*, i64, %runtime.interfaceMethodInfo* }
 %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 }
+@"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: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, %runtime.typecodeID*, i8*, i8*)
+declare i1 @runtime.typeAssert(i64, i8*, i8*, i8*)
 
 define void @runtime.initAll() unnamed_addr {
 entry:
@@ -22,7 +21,7 @@ entry:
 define internal void @main.init() unnamed_addr {
 entry:
   ; Test type asserts.
-  %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)
+  %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)
   store i1 %typecode, i1* @main.v1
   ret void
 }

interp/testdata/map.ll

@@ -1,74 +0,0 @@
-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.
-  %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.
-  %map.new = call %runtime.hashmap* @runtime.hashmapMake(i8 8, i8 1, i32 1, i8* undef, i8* null)
-  store %runtime.hashmap* %map.new, %runtime.hashmap** @main.stringMap
-  %map = load %runtime.hashmap*, %runtime.hashmap** @main.stringMap
-  ; Do the string set to the newly loaded map.
-  store i8 2, i8* %hashmap.value
-  call void @runtime.hashmapStringSet(%runtime.hashmap* %map, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @main.init.string, i32 0, i32 0), i32 7, i8* %hashmap.value, i8* undef, i8* null)
-  ret void
-}

interp/testdata/map.out.ll

@@ -1,20 +0,0 @@
-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 }
-
-@main.m = local_unnamed_addr global %runtime.hashmap* @"main$map"
-@main.binaryMap = local_unnamed_addr global %runtime.hashmap* @"main$map.1"
-@main.stringMap = local_unnamed_addr global %runtime.hashmap* @"main$map.3"
-@main.init.string = internal unnamed_addr constant [7 x i8] c"CONNECT"
-@"main$map" = internal global %runtime.hashmap { %runtime.hashmap* null, i8* getelementptr inbounds ({ [8 x i8], i8*, { i8, [7 x i8] }, { { [7 x i8]*, [4 x i8] }, [56 x i8] } }, { [8 x i8], i8*, { i8, [7 x i8] }, { { [7 x i8]*, [4 x i8] }, [56 x i8] } }* @"main$mapbucket", i32 0, i32 0, i32 0), i32 1, i8 1, i8 8, i8 0 }
-@"main$mapbucket" = internal unnamed_addr global { [8 x i8], i8*, { i8, [7 x i8] }, { { [7 x i8]*, [4 x i8] }, [56 x i8] } } { [8 x i8] c"\04\00\00\00\00\00\00\00", i8* null, { i8, [7 x i8] } { i8 1, [7 x i8] zeroinitializer }, { { [7 x i8]*, [4 x i8] }, [56 x i8] } { { [7 x i8]*, [4 x i8] } { [7 x i8]* @main.init.string, [4 x i8] c"\07\00\00\00" }, [56 x i8] zeroinitializer } }
-@"main$map.1" = internal global %runtime.hashmap { %runtime.hashmap* null, i8* getelementptr inbounds ({ [8 x i8], i8*, { i8, [7 x i8] }, { i8, [7 x i8] } }, { [8 x i8], i8*, { i8, [7 x i8] }, { i8, [7 x i8] } }* @"main$mapbucket.2", i32 0, i32 0, i32 0), i32 1, i8 1, i8 1, i8 0 }
-@"main$mapbucket.2" = internal unnamed_addr global { [8 x i8], i8*, { i8, [7 x i8] }, { i8, [7 x i8] } } { [8 x i8] c"\04\00\00\00\00\00\00\00", i8* null, { i8, [7 x i8] } { i8 1, [7 x i8] zeroinitializer }, { i8, [7 x i8] } { i8 2, [7 x i8] zeroinitializer } }
-@"main$map.3" = internal global %runtime.hashmap { %runtime.hashmap* null, i8* getelementptr inbounds ({ [8 x i8], i8*, { { [7 x i8]*, [4 x i8] }, [56 x i8] }, { i8, [7 x i8] } }, { [8 x i8], i8*, { { [7 x i8]*, [4 x i8] }, [56 x i8] }, { i8, [7 x i8] } }* @"main$mapbucket.4", i32 0, i32 0, i32 0), i32 1, i8 8, i8 1, i8 0 }
-@"main$mapbucket.4" = internal unnamed_addr global { [8 x i8], i8*, { { [7 x i8]*, [4 x i8] }, [56 x i8] }, { i8, [7 x i8] } } { [8 x i8] c"x\00\00\00\00\00\00\00", i8* null, { { [7 x i8]*, [4 x i8] }, [56 x i8] } { { [7 x i8]*, [4 x i8] } { [7 x i8]* @main.init.string, [4 x i8] c"\07\00\00\00" }, [56 x i8] zeroinitializer }, { i8, [7 x i8] } { i8 2, [7 x i8] zeroinitializer } }
-
-define void @runtime.initAll() unnamed_addr {
-entry:
-  ret void
-}

interp/testdata/phi.ll

@@ -0,0 +1,31 @@
+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
+}

interp/testdata/phi.out.ll

@@ -0,0 +1,9 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux"
+
+@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
+}

ir/ir.go

@@ -1,271 +0,0 @@
-package ir
-
-import (
-	"go/ast"
-	"go/types"
-	"sort"
-	"strings"
-
-	"github.com/tinygo-org/tinygo/loader"
-	"golang.org/x/tools/go/ssa"
-	"tinygo.org/x/go-llvm"
-)
-
-// This file provides a wrapper around go/ssa values and adds extra
-// functionality to them.
-
-// View on all functions, types, and globals in a program, with analysis
-// results.
-type Program struct {
-	Program       *ssa.Program
-	LoaderProgram *loader.Program
-	mainPkg       *ssa.Package
-	Functions     []*Function
-	functionMap   map[*ssa.Function]*Function
-}
-
-// Function or method.
-type Function struct {
-	*ssa.Function
-	LLVMFn   llvm.Value
-	module   string     // go:wasm-module
-	linkName string     // go:linkname, go:export
-	exported bool       // go:export
-	nobounds bool       // go:nobounds
-	flag     bool       // used by dead code elimination
-	inline   InlineType // go:inline
-}
-
-// Interface type that is at some point used in a type assert (to check whether
-// it implements another interface).
-type Interface struct {
-	Num  int
-	Type *types.Interface
-}
-
-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
-)
-
-// Create and initialize a new *Program from a *ssa.Program.
-func NewProgram(lprogram *loader.Program) *Program {
-	program := lprogram.LoadSSA()
-	program.Build()
-
-	mainPkg := program.Package(lprogram.MainPkg().Pkg)
-	if mainPkg == nil {
-		panic("could not find main package")
-	}
-	p := &Program{
-		Program:       program,
-		LoaderProgram: lprogram,
-		mainPkg:       mainPkg,
-		functionMap:   make(map[*ssa.Function]*Function),
-	}
-
-	for _, pkg := range lprogram.Sorted() {
-		p.AddPackage(program.Package(pkg.Pkg))
-	}
-
-	return p
-}
-
-// Add a package to this Program. All packages need to be added first before any
-// analysis is done for correct results.
-func (p *Program) AddPackage(pkg *ssa.Package) {
-	memberNames := make([]string, 0)
-	for name := range pkg.Members {
-		memberNames = append(memberNames, name)
-	}
-	sort.Strings(memberNames)
-
-	for _, name := range memberNames {
-		member := pkg.Members[name]
-		switch member := member.(type) {
-		case *ssa.Function:
-			p.addFunction(member)
-		case *ssa.Type:
-			methods := getAllMethods(pkg.Prog, member.Type())
-			if !types.IsInterface(member.Type()) {
-				// named type
-				for _, method := range methods {
-					p.addFunction(pkg.Prog.MethodValue(method))
-				}
-			}
-		case *ssa.Global:
-			// Ignore. Globals are not handled here.
-		case *ssa.NamedConst:
-			// Ignore: these are already resolved.
-		default:
-			panic("unknown member type: " + member.String())
-		}
-	}
-}
-
-func (p *Program) addFunction(ssaFn *ssa.Function) {
-	if _, ok := p.functionMap[ssaFn]; ok {
-		return
-	}
-	f := &Function{Function: ssaFn}
-	f.parsePragmas()
-	p.Functions = append(p.Functions, f)
-	p.functionMap[ssaFn] = f
-
-	for _, anon := range ssaFn.AnonFuncs {
-		p.addFunction(anon)
-	}
-}
-
-// 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
-}
-
-func (p *Program) GetFunction(ssaFn *ssa.Function) *Function {
-	return p.functionMap[ssaFn]
-}
-
-func (p *Program) MainPkg() *ssa.Package {
-	return p.mainPkg
-}
-
-// Parse compiler directives in the preceding comments.
-func (f *Function) parsePragmas() {
-	if f.Syntax() == nil {
-		return
-	}
-	if decl, ok := f.Syntax().(*ast.FuncDecl); ok && decl.Doc != nil {
-		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
-				}
-				f.linkName = parts[1]
-				f.exported = true
-			case "//go:wasm-module":
-				// Alternative comment for setting the import module.
-				if len(parts) != 2 {
-					continue
-				}
-				f.module = parts[1]
-			case "//go:inline":
-				f.inline = InlineHint
-			case "//go:noinline":
-				f.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) {
-					f.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) {
-					f.nobounds = true
-				}
-			}
-		}
-	}
-}
-
-func (f *Function) IsNoBounds() bool {
-	return f.nobounds
-}
-
-// Return true iff this function is externally visible.
-func (f *Function) IsExported() bool {
-	return f.exported || f.CName() != ""
-}
-
-// Return the inline directive of this function.
-func (f *Function) Inline() InlineType {
-	return f.inline
-}
-
-// Return the module name if not the default.
-func (f *Function) Module() string {
-	return f.module
-}
-
-// Return the link name for this function.
-func (f *Function) LinkName() string {
-	if f.linkName != "" {
-		return f.linkName
-	}
-	if f.Signature.Recv() != nil {
-		// Method on a defined type (which may be a pointer).
-		return f.RelString(nil)
-	} else {
-		// Bare function.
-		if name := f.CName(); name != "" {
-			// Name CGo functions directly.
-			return name
-		} else {
-			return f.RelString(nil)
-		}
-	}
-}
-
-// Return the name of the C function if this is a CGo wrapper. Otherwise, return
-// a zero-length string.
-func (f *Function) CName() string {
-	name := f.Name()
-	if strings.HasPrefix(name, "_Cfunc_") {
-		// emitted by `go tool cgo`
-		return name[len("_Cfunc_"):]
-	}
-	if strings.HasPrefix(name, "C.") {
-		// created by ../loader/cgo.go
-		return name[2:]
-	}
-	return ""
-}
-
-// 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
-}

ir/passes.go

@@ -1,149 +0,0 @@
-package ir
-
-import (
-	"errors"
-	"go/types"
-
-	"golang.org/x/tools/go/ssa"
-)
-
-// This file implements several optimization passes (analysis + transform) to
-// optimize code in SSA form before it is compiled to LLVM IR. It is based on
-// the IR defined in ir.go.
-
-// Make 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
-}
-
-// Simple pass that removes dead code. This pass makes later analysis passes
-// more useful.
-func (p *Program) SimpleDCE() error {
-	// Unmark all functions.
-	for _, f := range p.Functions {
-		f.flag = false
-	}
-
-	// Initial set of live functions. Include main.main, *.init and runtime.*
-	// functions.
-	main, ok := p.mainPkg.Members["main"].(*ssa.Function)
-	if !ok {
-		if p.mainPkg.Members["main"] == nil {
-			return errors.New("function main is undeclared in the main package")
-		} else {
-			return errors.New("cannot declare main - must be func")
-		}
-	}
-	runtimePkg := p.Program.ImportedPackage("runtime")
-	mathPkg := p.Program.ImportedPackage("math")
-	taskPkg := p.Program.ImportedPackage("internal/task")
-	p.GetFunction(main).flag = true
-	worklist := []*ssa.Function{main}
-	for _, f := range p.Functions {
-		if f.exported || f.Synthetic == "package initializer" || f.Pkg == runtimePkg || f.Pkg == taskPkg || (f.Pkg == mathPkg && f.Pkg != nil) {
-			if f.flag {
-				continue
-			}
-			f.flag = true
-			worklist = append(worklist, f.Function)
-		}
-	}
-
-	// Mark all called functions recursively.
-	for len(worklist) != 0 {
-		f := worklist[len(worklist)-1]
-		worklist = worklist[:len(worklist)-1]
-		for _, block := range f.Blocks {
-			for _, instr := range block.Instrs {
-				if instr, ok := instr.(*ssa.MakeInterface); ok {
-					for _, sel := range getAllMethods(p.Program, instr.X.Type()) {
-						fn := p.Program.MethodValue(sel)
-						callee := p.GetFunction(fn)
-						if callee == nil {
-							// TODO: why is this necessary?
-							p.addFunction(fn)
-							callee = p.GetFunction(fn)
-						}
-						if !callee.flag {
-							callee.flag = true
-							worklist = append(worklist, callee.Function)
-						}
-					}
-				}
-				for _, operand := range instr.Operands(nil) {
-					if operand == nil || *operand == nil {
-						continue
-					}
-					switch operand := (*operand).(type) {
-					case *ssa.Function:
-						f := p.GetFunction(operand)
-						if f == nil {
-							// FIXME HACK: this function should have been
-							// discovered already. It is not for bound methods.
-							p.addFunction(operand)
-							f = p.GetFunction(operand)
-						}
-						if !f.flag {
-							f.flag = true
-							worklist = append(worklist, operand)
-						}
-					}
-				}
-			}
-		}
-	}
-
-	// Remove unmarked functions.
-	livefunctions := []*Function{}
-	for _, f := range p.Functions {
-		if f.flag {
-			livefunctions = append(livefunctions, f)
-		} else {
-			delete(p.functionMap, f.Function)
-		}
-	}
-	p.Functions = livefunctions
-
-	return nil
-}

loader/loader.go

@@ -2,6 +2,7 @@ package loader
 
 import (
 	"bytes"
+	"crypto/sha512"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -11,12 +12,12 @@ import (
 	"go/token"
 	"go/types"
 	"io"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strconv"
 	"strings"
-	"syscall"
 
 	"github.com/tinygo-org/tinygo/cgo"
 	"github.com/tinygo-org/tinygo/compileopts"
@@ -52,7 +53,8 @@ type PackageJSON struct {
 	CFiles   []string
 
 	// Dependency information
-	Imports []string
+	Imports   []string
+	ImportMap map[string]string
 
 	// Error information
 	Error *struct {
@@ -66,10 +68,12 @@ type PackageJSON struct {
 type Package struct {
 	PackageJSON
 
-	program *Program
-	Files   []*ast.File
-	Pkg     *types.Package
-	info    types.Info
+	program    *Program
+	Files      []*ast.File
+	FileHashes map[string][]byte
+	CFlags     []string // CFlags used during CGo preprocessing (only set if CGo is used)
+	Pkg        *types.Package
+	info       types.Info
 }
 
 // Load loads the given package with all dependencies (including the runtime
@@ -109,10 +113,7 @@ func Load(config *compileopts.Config, inputPkgs []string, clangHeaders string, t
 	err = cmd.Run()
 	if err != nil {
 		if exitErr, ok := err.(*exec.ExitError); ok {
-			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
-				os.Exit(status.ExitStatus())
-			}
-			os.Exit(1)
+			os.Exit(exitErr.ExitCode())
 		}
 		return nil, fmt.Errorf("failed to run `go list`: %s", err)
 	}
@@ -121,7 +122,8 @@ func Load(config *compileopts.Config, inputPkgs []string, clangHeaders string, t
 	decoder := json.NewDecoder(buf)
 	for {
 		pkg := &Package{
-			program: p,
+			program:    p,
+			FileHashes: make(map[string][]byte),
 			info: types.Info{
 				Types:      make(map[ast.Expr]types.TypeAndValue),
 				Defs:       make(map[*ast.Ident]types.Object),
@@ -280,17 +282,15 @@ func (p *Program) Parse() error {
 }
 
 // parseFile is a wrapper around parser.ParseFile.
-func (p *Program) parseFile(path string, mode parser.Mode) (*ast.File, error) {
-	if p.fset == nil {
-		p.fset = token.NewFileSet()
-	}
-
-	rd, err := os.Open(path)
+func (p *Package) parseFile(path string, mode parser.Mode) (*ast.File, error) {
+	originalPath := p.program.getOriginalPath(path)
+	data, err := ioutil.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}
-	defer rd.Close()
-	return parser.ParseFile(p.fset, p.getOriginalPath(path), rd, mode)
+	sum := sha512.Sum512_224(data)
+	p.FileHashes[originalPath] = sum[:]
+	return parser.ParseFile(p.program.fset, originalPath, data, mode)
 }
 
 // Parse parses and typechecks this package.
@@ -366,7 +366,7 @@ func (p *Package) parseFiles() ([]*ast.File, error) {
 		if !filepath.IsAbs(file) {
 			file = filepath.Join(p.Dir, file)
 		}
-		f, err := p.program.parseFile(file, parser.ParseComments)
+		f, err := p.parseFile(file, parser.ParseComments)
 		if err != nil {
 			fileErrs = append(fileErrs, err)
 			return
@@ -382,13 +382,17 @@ func (p *Package) parseFiles() ([]*ast.File, error) {
 
 	// Do CGo processing.
 	if len(p.CgoFiles) != 0 {
-		var cflags []string
-		cflags = append(cflags, p.program.config.CFlags()...)
-		cflags = append(cflags, "-I"+p.Dir)
+		var initialCFlags []string
+		initialCFlags = append(initialCFlags, p.program.config.CFlags()...)
+		initialCFlags = append(initialCFlags, "-I"+p.Dir)
 		if p.program.clangHeaders != "" {
-			cflags = append(cflags, "-Xclang", "-internal-isystem", "-Xclang", p.program.clangHeaders)
+			initialCFlags = append(initialCFlags, "-Xclang", "-internal-isystem", "-Xclang", p.program.clangHeaders)
+		}
+		generated, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.program.fset, initialCFlags)
+		p.CFlags = append(initialCFlags, cflags...)
+		for path, hash := range accessedFiles {
+			p.FileHashes[path] = hash
 		}
-		generated, ldflags, errs := cgo.Process(files, p.program.workingDir, p.program.fset, cflags)
 		if errs != nil {
 			fileErrs = append(fileErrs, errs...)
 		}
@@ -411,6 +415,9 @@ func (p *Package) Import(to string) (*types.Package, error) {
 	if to == "unsafe" {
 		return types.Unsafe, nil
 	}
+	if newTo, ok := p.ImportMap[to]; ok && !strings.HasSuffix(newTo, ".test]") {
+		to = newTo
+	}
 	if imported, ok := p.program.Packages[to]; ok {
 		return imported.Pkg, nil
 	} else {

main.go

@@ -13,19 +13,24 @@ import (
 	"os/exec"
 	"os/signal"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strings"
-	"syscall"
+	"sync/atomic"
 	"time"
 
+	"github.com/google/shlex"
+	"github.com/mattn/go-colorable"
 	"github.com/tinygo-org/tinygo/builder"
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/interp"
 	"github.com/tinygo-org/tinygo/loader"
+	"github.com/tinygo-org/tinygo/transform"
 	"tinygo.org/x/go-llvm"
 
 	"go.bug.st/serial"
+	"go.bug.st/serial/enumerator"
 )
 
 var (
@@ -91,7 +96,7 @@ func copyFile(src, dst string) error {
 // executeCommand is a simple wrapper to exec.Cmd
 func executeCommand(options *compileopts.Options, name string, arg ...string) *exec.Cmd {
 	if options.PrintCommands {
-		fmt.Printf("%s %s\n ", name, strings.Join(arg, " "))
+		fmt.Printf("%s %s\n", name, strings.Join(arg, " "))
 	}
 	return exec.Command(name, arg...)
 }
@@ -163,10 +168,7 @@ func Test(pkgName string, options *compileopts.Options, testCompileOnly bool, ou
 			if err != nil {
 				// Propagate the exit code
 				if err, ok := err.(*exec.ExitError); ok {
-					if status, ok := err.Sys().(syscall.WaitStatus); ok {
-						os.Exit(status.ExitStatus())
-					}
-					os.Exit(1)
+					os.Exit(err.ExitCode())
 				}
 				return &commandError{"failed to run compiled binary", result.Binary, err}
 			}
@@ -241,15 +243,12 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 	return builder.Build(pkgName, fileExt, config, func(result builder.BuildResult) error {
 		// do we need port reset to put MCU into bootloader mode?
 		if config.Target.PortReset == "true" && flashMethod != "openocd" {
-			if port == "" {
-				var err error
-				port, err = getDefaultPort()
-				if err != nil {
-					return err
-				}
+			port, err := getDefaultPort(strings.FieldsFunc(port, func(c rune) bool { return c == ',' }))
+			if err != nil {
+				return err
 			}
 
-			err := touchSerialPortAt1200bps(port)
+			err = touchSerialPortAt1200bps(port)
 			if err != nil {
 				return &commandError{"failed to reset port", result.Binary, err}
 			}
@@ -263,17 +262,17 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			// Create the command.
 			flashCmd := config.Target.FlashCommand
 			fileToken := "{" + fileExt[1:] + "}"
-			flashCmd = strings.Replace(flashCmd, fileToken, result.Binary, -1)
+			flashCmd = strings.ReplaceAll(flashCmd, fileToken, result.Binary)
 
-			if port == "" && strings.Contains(flashCmd, "{port}") {
+			if strings.Contains(flashCmd, "{port}") {
 				var err error
-				port, err = getDefaultPort()
+				port, err = getDefaultPort(strings.FieldsFunc(port, func(c rune) bool { return c == ',' }))
 				if err != nil {
 					return err
 				}
 			}
 
-			flashCmd = strings.Replace(flashCmd, "{port}", port, -1)
+			flashCmd = strings.ReplaceAll(flashCmd, "{port}", port)
 
 			// Execute the command.
 			var cmd *exec.Cmd
@@ -345,8 +344,9 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 	if err != nil {
 		return err
 	}
-	if config.Target.GDB == "" {
-		return errors.New("gdb not configured in the target specification")
+	gdb, err := config.Target.LookupGDB()
+	if err != nil {
+		return err
 	}
 
 	return builder.Build(pkgName, "", config, func(result builder.BuildResult) error {
@@ -392,7 +392,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			if ocdOutput {
 				// Make it clear which output is from the daemon.
 				w := &ColorWriter{
-					Out:    os.Stderr,
+					Out:    colorable.NewColorableStderr(),
 					Prefix: "openocd: ",
 					Color:  TermColorYellow,
 				}
@@ -407,7 +407,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			if ocdOutput {
 				// Make it clear which output is from the daemon.
 				w := &ColorWriter{
-					Out:    os.Stderr,
+					Out:    colorable.NewColorableStderr(),
 					Prefix: "jlink: ",
 					Color:  TermColorYellow,
 				}
@@ -464,8 +464,15 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			}
 			defer func() {
 				daemon.Process.Signal(os.Interrupt)
-				// Maybe we should send a .Kill() after x seconds?
+				var stopped uint32
+				go func() {
+					time.Sleep(time.Millisecond * 100)
+					if atomic.LoadUint32(&stopped) == 0 {
+						daemon.Process.Kill()
+					}
+				}()
 				daemon.Wait()
+				atomic.StoreUint32(&stopped, 1)
 			}()
 		}
 
@@ -484,7 +491,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		for _, cmd := range gdbCommands {
 			params = append(params, "-ex", cmd)
 		}
-		cmd := executeCommand(config.Options, config.Target.GDB, params...)
+		cmd := executeCommand(config.Options, gdb, params...)
 		cmd.Stdin = os.Stdin
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
@@ -658,41 +665,66 @@ func windowsFindUSBDrive(volume string, options *compileopts.Options) (string, e
 }
 
 // getDefaultPort returns the default serial port depending on the operating system.
-func getDefaultPort() (port string, err error) {
-	var portPath string
+func getDefaultPort(portCandidates []string) (port string, err error) {
+	if len(portCandidates) == 1 {
+		return portCandidates[0], nil
+	}
+
+	var ports []string
 	switch runtime.GOOS {
-	case "darwin":
-		portPath = "/dev/cu.usb*"
-	case "linux":
-		portPath = "/dev/ttyACM*"
 	case "freebsd":
-		portPath = "/dev/cuaU*"
-	case "windows":
-		ports, err := serial.GetPortsList()
+		ports, err = filepath.Glob("/dev/cuaU*")
+	case "darwin", "linux", "windows":
+		var portsList []*enumerator.PortDetails
+		portsList, err = enumerator.GetDetailedPortsList()
 		if err != nil {
 			return "", err
 		}
 
-		if len(ports) == 0 {
-			return "", errors.New("no serial ports available")
-		} else if len(ports) > 1 {
-			return "", errors.New("multiple serial ports available - use -port flag")
+		for _, p := range portsList {
+			ports = append(ports, p.Name)
 		}
 
-		return ports[0], nil
+		if ports == nil || len(ports) == 0 {
+			// fallback
+			switch runtime.GOOS {
+			case "darwin":
+				ports, err = filepath.Glob("/dev/cu.usb*")
+			case "linux":
+				ports, err = filepath.Glob("/dev/ttyACM*")
+			case "windows":
+				ports, err = serial.GetPortsList()
+			}
+		}
 	default:
 		return "", errors.New("unable to search for a default USB device to be flashed on this OS")
 	}
 
-	d, err := filepath.Glob(portPath)
 	if err != nil {
 		return "", err
-	}
-	if d == nil {
+	} else if ports == nil {
 		return "", errors.New("unable to locate a serial port")
+	} else if len(ports) == 0 {
+		return "", errors.New("no serial ports available")
 	}
 
-	return d[0], nil
+	if len(portCandidates) == 0 {
+		if len(ports) == 1 {
+			return ports[0], nil
+		} else {
+			return "", errors.New("multiple serial ports available - use -port flag, available ports are " + strings.Join(ports, ", "))
+		}
+	}
+
+	for _, ps := range portCandidates {
+		for _, p := range ports {
+			if p == ps {
+				return p, nil
+			}
+		}
+	}
+
+	return "", errors.New("port you specified '" + strings.Join(portCandidates, ",") + "' does not exist, available ports are " + strings.Join(ports, ", "))
 }
 
 func usage() {
@@ -767,6 +799,15 @@ func printCompilerError(logln func(...interface{}), err error) {
 				logln()
 			}
 		}
+	case transform.CoroutinesError:
+		logln(err.Pos.String() + ": " + err.Msg)
+		logln("\ntraceback:")
+		for _, line := range err.Traceback {
+			logln(line.Name)
+			if line.Position.IsValid() {
+				logln("\t" + line.Position.String())
+			}
+		}
 	case loader.Errors:
 		logln("#", err.Pkg.ImportPath)
 		for _, err := range err.Errs {
@@ -796,6 +837,52 @@ func handleCompilerError(err error) {
 	}
 }
 
+// This is a special type for the -X flag to parse the pkgpath.Var=stringVal
+// format. It has to be a special type to allow multiple variables to be defined
+// this way.
+type globalValuesFlag map[string]map[string]string
+
+func (m globalValuesFlag) String() string {
+	return "pkgpath.Var=value"
+}
+
+func (m globalValuesFlag) Set(value string) error {
+	equalsIndex := strings.IndexByte(value, '=')
+	if equalsIndex < 0 {
+		return errors.New("expected format pkgpath.Var=value")
+	}
+	pathAndName := value[:equalsIndex]
+	pointIndex := strings.LastIndexByte(pathAndName, '.')
+	if pointIndex < 0 {
+		return errors.New("expected format pkgpath.Var=value")
+	}
+	path := pathAndName[:pointIndex]
+	name := pathAndName[pointIndex+1:]
+	stringValue := value[equalsIndex+1:]
+	if m[path] == nil {
+		m[path] = make(map[string]string)
+	}
+	m[path][name] = stringValue
+	return nil
+}
+
+// parseGoLinkFlag parses the -ldflags parameter. Its primary purpose right now
+// is the -X flag, for setting the value of global string variables.
+func parseGoLinkFlag(flagsString string) (map[string]map[string]string, error) {
+	set := flag.NewFlagSet("link", flag.ExitOnError)
+	globalVarValues := make(globalValuesFlag)
+	set.Var(globalVarValues, "X", "Set the value of the string variable to the given value.")
+	flags, err := shlex.Split(flagsString)
+	if err != nil {
+		return nil, err
+	}
+	err = set.Parse(flags)
+	if err != nil {
+		return nil, err
+	}
+	return map[string]map[string]string(globalVarValues), nil
+}
+
 func main() {
 	if len(os.Args) < 2 {
 		fmt.Fprintln(os.Stderr, "No command-line arguments supplied.")
@@ -815,13 +902,13 @@ func main() {
 	target := flag.String("target", "", "LLVM target | .json file with TargetSpec")
 	printSize := flag.String("size", "", "print sizes (none, short, full)")
 	printStacks := flag.Bool("print-stacks", false, "print stack sizes of goroutines")
+	printAllocsString := flag.String("print-allocs", "", "regular expression of functions for which heap allocations should be printed")
 	printCommands := flag.Bool("x", false, "Print commands")
 	nodebug := flag.Bool("no-debug", false, "disable DWARF debug symbol generation")
 	ocdOutput := flag.Bool("ocd-output", false, "print OCD daemon output during debug")
-	port := flag.String("port", "", "flash port")
+	port := flag.String("port", "", "flash port (can specify multiple candidates separated by commas)")
 	programmer := flag.String("programmer", "", "which hardware programmer to use")
-	cFlags := flag.String("cflags", "", "additional cflags for compiler")
-	ldFlags := flag.String("ldflags", "", "additional ldflags for linker")
+	ldflags := flag.String("ldflags", "", "Go link tool compatible ldflags")
 	wasmAbi := flag.String("wasm-abi", "", "WebAssembly ABI conventions: js (no i64 params) or generic")
 
 	var flagJSON, flagDeps *bool
@@ -851,6 +938,19 @@ func main() {
 	}
 
 	flag.CommandLine.Parse(os.Args[2:])
+	globalVarValues, err := parseGoLinkFlag(*ldflags)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	var printAllocs *regexp.Regexp
+	if *printAllocsString != "" {
+		printAllocs, err = regexp.Compile(*printAllocsString)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+	}
 	options := &compileopts.Options{
 		Target:        *target,
 		Opt:           *opt,
@@ -863,23 +963,17 @@ func main() {
 		Debug:         !*nodebug,
 		PrintSizes:    *printSize,
 		PrintStacks:   *printStacks,
+		PrintAllocs:   printAllocs,
 		PrintCommands: *printCommands,
 		Tags:          *tags,
+		GlobalValues:  globalVarValues,
 		WasmAbi:       *wasmAbi,
 		Programmer:    *programmer,
 	}
 
-	if *cFlags != "" {
-		options.CFlags = strings.Split(*cFlags, " ")
-	}
-
-	if *ldFlags != "" {
-		options.LDFlags = strings.Split(*ldFlags, " ")
-	}
-
 	os.Setenv("CC", "clang -target="+*target)
 
-	err := options.Verify()
+	err = options.Verify()
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err.Error())
 		usage()
@@ -932,9 +1026,17 @@ func main() {
 			fmt.Fprintf(os.Stderr, "Unknown library: %s\n", name)
 			os.Exit(1)
 		}
-		path, err := lib.Load(*target)
+		tmpdir, err := ioutil.TempDir("", "tinygo*")
+		if err != nil {
+			handleCompilerError(err)
+		}
+		defer os.RemoveAll(tmpdir)
+		path, err := lib.Load(*target, tmpdir)
 		handleCompilerError(err)
-		copyFile(path, outpath)
+		err = copyFile(path, outpath)
+		if err != nil {
+			handleCompilerError(err)
+		}
 	case "flash", "gdb":
 		pkgName := filepath.ToSlash(flag.Arg(0))
 		if command == "flash" {
@@ -1053,10 +1155,7 @@ func main() {
 		err = cmd.Run()
 		if err != nil {
 			if exitErr, ok := err.(*exec.ExitError); ok {
-				if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
-					os.Exit(status.ExitStatus())
-				}
-				os.Exit(1)
+				os.Exit(exitErr.ExitCode())
 			}
 			fmt.Fprintln(os.Stderr, "failed to run `go list`:", err)
 			os.Exit(1)

main_test.go

@@ -13,7 +13,6 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
-	"sort"
 	"strings"
 	"sync"
 	"testing"
@@ -29,35 +28,43 @@ const TESTDATA = "testdata"
 var testTarget = flag.String("target", "", "override test target")
 
 func TestCompiler(t *testing.T) {
-	matches, err := filepath.Glob(filepath.Join(TESTDATA, "*.go"))
-	if err != nil {
-		t.Fatal("could not read test files:", err)
+	tests := []string{
+		"alias.go",
+		"atomic.go",
+		"binop.go",
+		"calls.go",
+		"cgo/",
+		"channel.go",
+		"coroutines.go",
+		"float.go",
+		"gc.go",
+		"init.go",
+		"init_multi.go",
+		"interface.go",
+		"json.go",
+		"map.go",
+		"math.go",
+		"print.go",
+		"reflect.go",
+		"slice.go",
+		"sort.go",
+		"stdlib.go",
+		"string.go",
+		"structs.go",
+		"zeroalloc.go",
 	}
 
-	dirMatches, err := filepath.Glob(filepath.Join(TESTDATA, "*", "main.go"))
-	if err != nil {
-		t.Fatal("could not read test packages:", err)
-	}
-	if len(matches) == 0 || len(dirMatches) == 0 {
-		t.Fatal("no test files found")
-	}
-	for _, m := range dirMatches {
-		matches = append(matches, filepath.Dir(m)+string(filepath.Separator))
-	}
-
-	sort.Strings(matches)
-
 	if *testTarget != "" {
 		// This makes it possible to run one specific test (instead of all),
 		// which is especially useful to quickly check whether some changes
 		// affect a particular target architecture.
-		runPlatTests(*testTarget, matches, t)
+		runPlatTests(*testTarget, tests, t)
 		return
 	}
 
 	if runtime.GOOS != "windows" {
 		t.Run("Host", func(t *testing.T) {
-			runPlatTests("", matches, t)
+			runPlatTests("", tests, t)
 		})
 	}
 
@@ -66,26 +73,26 @@ func TestCompiler(t *testing.T) {
 	}
 
 	t.Run("EmulatedCortexM3", func(t *testing.T) {
-		runPlatTests("cortex-m-qemu", matches, t)
+		runPlatTests("cortex-m-qemu", tests, t)
 	})
 
 	if runtime.GOOS == "windows" || runtime.GOOS == "darwin" {
 		// Note: running only on Windows and macOS because Linux (as of 2020)
 		// usually has an outdated QEMU version that doesn't support RISC-V yet.
 		t.Run("EmulatedRISCV", func(t *testing.T) {
-			runPlatTests("riscv-qemu", matches, t)
+			runPlatTests("riscv-qemu", tests, t)
 		})
 	}
 
 	if runtime.GOOS == "linux" {
 		t.Run("X86Linux", func(t *testing.T) {
-			runPlatTests("i386--linux-gnu", matches, t)
+			runPlatTests("i386--linux-gnu", tests, t)
 		})
 		t.Run("ARMLinux", func(t *testing.T) {
-			runPlatTests("arm--linux-gnueabihf", matches, t)
+			runPlatTests("arm--linux-gnueabihf", tests, t)
 		})
 		t.Run("ARM64Linux", func(t *testing.T) {
-			runPlatTests("aarch64--linux-gnu", matches, t)
+			runPlatTests("aarch64--linux-gnu", tests, t)
 		})
 		goVersion, err := goenv.GorootVersionString(goenv.Get("GOROOT"))
 		if err != nil {
@@ -98,25 +105,72 @@ func TestCompiler(t *testing.T) {
 			// below that are also not supported but still seem to pass, so
 			// include them in the tests for now.
 			t.Run("WebAssembly", func(t *testing.T) {
-				runPlatTests("wasm", matches, t)
+				runPlatTests("wasm", tests, t)
 			})
 		}
 
 		t.Run("WASI", func(t *testing.T) {
-			runPlatTests("wasi", matches, t)
+			runPlatTests("wasi", tests, t)
 		})
 	}
+
+	// Test a few build options.
+	t.Run("build-options", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			// These tests assume a host that is supported by TinyGo.
+			t.Skip("can't test build options on Windows")
+		}
+		t.Parallel()
+
+		// Test with few optimizations enabled (no inlining, etc).
+		t.Run("opt=1", func(t *testing.T) {
+			t.Parallel()
+			runTestWithConfig("stdlib.go", "", t, &compileopts.Options{
+				Opt: "1",
+			}, nil, nil)
+		})
+
+		// Test with only the bare minimum of optimizations enabled.
+		// TODO: fix this for stdlib.go, which currently fails.
+		t.Run("opt=0", func(t *testing.T) {
+			t.Parallel()
+			runTestWithConfig("print.go", "", t, &compileopts.Options{
+				Opt: "0",
+			}, nil, nil)
+		})
+
+		t.Run("ldflags", func(t *testing.T) {
+			t.Parallel()
+			runTestWithConfig("ldflags.go", "", t, &compileopts.Options{
+				Opt: "z",
+				GlobalValues: map[string]map[string]string{
+					"main": {
+						"someGlobal": "foobar",
+					},
+				},
+			}, nil, nil)
+		})
+	})
 }
 
-func runPlatTests(target string, matches []string, t *testing.T) {
+func runPlatTests(target string, tests []string, t *testing.T) {
 	t.Parallel()
 
-	for _, path := range matches {
-		path := path // redefine to avoid race condition
-
-		t.Run(filepath.Base(path), func(t *testing.T) {
+	for _, name := range tests {
+		name := name // redefine to avoid race condition
+		t.Run(name, func(t *testing.T) {
 			t.Parallel()
-			runTest(path, target, t)
+			runTest(name, target, t, nil, nil)
+		})
+	}
+	if target == "wasi" || target == "" {
+		t.Run("filesystem.go", func(t *testing.T) {
+			t.Parallel()
+			runTest("filesystem.go", target, t, nil, nil)
+		})
+		t.Run("env.go", func(t *testing.T) {
+			t.Parallel()
+			runTest("env.go", target, t, []string{"first", "second"}, []string{"ENV1=VALUE1", "ENV2=VALUE2"})
 		})
 	}
 }
@@ -133,10 +187,28 @@ func runBuild(src, out string, opts *compileopts.Options) error {
 	return Build(src, out, opts)
 }
 
-func runTest(path, target string, t *testing.T) {
+func runTest(name, target string, t *testing.T, cmdArgs, environmentVars []string) {
+	options := &compileopts.Options{
+		Target:     target,
+		Opt:        "z",
+		PrintIR:    false,
+		DumpSSA:    false,
+		VerifyIR:   true,
+		Debug:      true,
+		PrintSizes: "",
+		WasmAbi:    "",
+	}
+	runTestWithConfig(name, target, t, options, cmdArgs, environmentVars)
+}
+
+func runTestWithConfig(name, target string, t *testing.T, options *compileopts.Options, cmdArgs, environmentVars []string) {
+	// Get the expected output for this test.
+	// Note: not using filepath.Join as it strips the path separator at the end
+	// of the path.
+	path := TESTDATA + "/" + name
 	// Get the expected output for this test.
 	txtpath := path[:len(path)-3] + ".txt"
-	if path[len(path)-1] == os.PathSeparator {
+	if path[len(path)-1] == '/' {
 		txtpath = path + "out.txt"
 	}
 	expected, err := ioutil.ReadFile(txtpath)
@@ -157,19 +229,8 @@ func runTest(path, target string, t *testing.T) {
 	}()
 
 	// Build the test binary.
-	config := &compileopts.Options{
-		Target:     target,
-		Opt:        "z",
-		PrintIR:    false,
-		DumpSSA:    false,
-		VerifyIR:   true,
-		Debug:      true,
-		PrintSizes: "",
-		WasmAbi:    "",
-	}
-
 	binary := filepath.Join(tmpdir, "test")
-	err = runBuild("./"+path, binary, config)
+	err = runBuild("./"+path, binary, options)
 	if err != nil {
 		printCompilerError(t.Log, err)
 		t.Fail()
@@ -182,6 +243,8 @@ func runTest(path, target string, t *testing.T) {
 	ranTooLong := false
 	if target == "" {
 		cmd = exec.Command(binary)
+		cmd.Env = append(cmd.Env, environmentVars...)
+		cmd.Args = append(cmd.Args, cmdArgs...)
 	} else {
 		spec, err := compileopts.LoadTarget(target)
 		if err != nil {
@@ -193,6 +256,17 @@ func runTest(path, target string, t *testing.T) {
 			args := append(spec.Emulator[1:], binary)
 			cmd = exec.Command(spec.Emulator[0], args...)
 		}
+
+		if len(spec.Emulator) != 0 && spec.Emulator[0] == "wasmtime" {
+			// Allow reading from the current directory.
+			cmd.Args = append(cmd.Args, "--dir=.")
+			for _, v := range environmentVars {
+				cmd.Args = append(cmd.Args, "--env", v)
+			}
+			cmd.Args = append(cmd.Args, cmdArgs...)
+		} else {
+			cmd.Env = append(cmd.Env, environmentVars...)
+		}
 	}
 	stdout := &bytes.Buffer{}
 	cmd.Stdout = stdout

src/device/sam/atsame5x-bitfields.go

@@ -0,0 +1,71 @@
+// Hand created file. DO NOT DELETE.
+// atsamd51x bitfield definitions that are not auto-generated by gen-device-svd.go
+
+// +build sam,atsame5x
+
+// These are the supported pchctrl function numberings on the atsamd51x
+// See http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D5xE5x_Family_Data_Sheet_DS60001507F.pdf
+// table 14-9
+
+package sam
+
+const (
+	PCHCTRL_GCLK_OSCCTRL_DFLL48     = 0 // DFLL48 input clock source
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0     = 1 // Reference clock for FDPLL0
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1     = 2 // Reference clock for FDPLL1
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0_32K = 3 // FDPLL0 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1_32K = 3 // FDPLL1 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_SDHC0_SLOW         = 3 // SDHC0 = 3 // Slow
+	PCHCTRL_GCLK_SDHC1_SLOW         = 3 // SDHC1 = 3 // Slow
+	PCHCTRL_GCLK_SERCOMX_SLOW       = 3 // GCLK_SERCOM[0..7]_SLOW = 3
+	PCHCTRL_GCLK_EIC                = 4
+	PCHCTRL_GCLK_FREQM_MSR          = 5 // FREQM Measure
+	PCHCTRL_GCLK_FREQM_REF          = 6 // FREQM Reference
+	PCHCTRL_GCLK_SERCOM0_CORE       = 7 // SERCOM0 Core
+	PCHCTRL_GCLK_SERCOM1_CORE       = 8 // SERCOM1 Core
+	PCHCTRL_GCLK_TC0                = 9
+	PCHCTRL_GCLK_TC1                = 9  // TC0, TC1
+	PCHCTRL_GCLK_USB                = 10 // USB
+	PCHCTRL_GCLK_EVSYS0             = 11
+	PCHCTRL_GCLK_EVSYS1             = 12
+	PCHCTRL_GCLK_EVSYS2             = 13
+	PCHCTRL_GCLK_EVSYS3             = 14
+	PCHCTRL_GCLK_EVSYS4             = 15
+	PCHCTRL_GCLK_EVSYS5             = 16
+	PCHCTRL_GCLK_EVSYS6             = 17
+	PCHCTRL_GCLK_EVSYS7             = 18
+	PCHCTRL_GCLK_EVSYS8             = 19
+	PCHCTRL_GCLK_EVSYS9             = 20
+	PCHCTRL_GCLK_EVSYS10            = 21
+	PCHCTRL_GCLK_EVSYS11            = 22
+	PCHCTRL_GCLK_SERCOM2_CORE       = 23 // SERCOM2 Core
+	PCHCTRL_GCLK_SERCOM3_CORE       = 24 // SERCOM3 Core
+	PCHCTRL_GCLK_TCC0               = 25
+	PCHCTRL_GCLK_TCC1               = 25 // TCC0, TCC1
+	PCHCTRL_GCLK_TC2                = 26
+	PCHCTRL_GCLK_TC3                = 26 // TC2, TC3
+	PCHCTRL_GCLK_CAN0               = 27 // CAN0
+	PCHCTRL_GCLK_CAN1               = 28 // CAN1
+	PCHCTRL_GCLK_TCC2               = 29
+	PCHCTRL_GCLK_TCC3               = 29 // TCC2, TCC3
+	PCHCTRL_GCLK_TC4                = 30
+	PCHCTRL_GCLK_TC5                = 30 // TC4, TC5
+	PCHCTRL_GCLK_PDEC               = 31 // PDEC
+	PCHCTRL_GCLK_AC                 = 32 // AC
+	PCHCTRL_GCLK_CCL                = 33 // CCL
+	PCHCTRL_GCLK_SERCOM4_CORE       = 34 // SERCOM4 Core
+	PCHCTRL_GCLK_SERCOM5_CORE       = 35 // SERCOM5 Core
+	PCHCTRL_GCLK_SERCOM6_CORE       = 36 // SERCOM6 Core
+	PCHCTRL_GCLK_SERCOM7_CORE       = 37 // SERCOM7 Core
+	PCHCTRL_GCLK_TCC4               = 38 // TCC4
+	PCHCTRL_GCLK_TC6                = 39
+	PCHCTRL_GCLK_TC7                = 39 // TC6, TC7
+	PCHCTRL_GCLK_ADC0               = 40 // ADC0
+	PCHCTRL_GCLK_ADC1               = 41 // ADC1
+	PCHCTRL_GCLK_DAC                = 42 // DAC
+	PCHCTRL_GCLK_I2S0               = 43
+	PCHCTRL_GCLK_I2S1               = 44
+	PCHCTRL_GCLK_SDHC0              = 45 // SDHC0
+	PCHCTRL_GCLK_SDHC1              = 46 // SDHC1
+	PCHCTRL_GCLK_CM4_TRACE          = 47 // CM4 Trace
+)

src/examples/adc/adc.go

@@ -15,7 +15,7 @@ func main() {
 	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
 
 	sensor := machine.ADC{machine.ADC2}
-	sensor.Configure()
+	sensor.Configure(machine.ADCConfig{})
 
 	for {
 		val := sensor.Get()

src/examples/pwm/arduino-mega1280.go

@@ -0,0 +1,12 @@
+// +build arduino_mega1280
+
+package main
+
+import "machine"
+
+var (
+	// Configuration on an Arduino Uno.
+	pwm  = machine.Timer3
+	pinA = machine.PH3 // pin 6 on the Mega
+	pinB = machine.PH4 // pin 7 on the Mega
+)

src/examples/pwm/arduino.go

@@ -0,0 +1,12 @@
+// +build arduino
+
+package main
+
+import "machine"
+
+var (
+	// Configuration on an Arduino Uno.
+	pwm  = machine.Timer2
+	pinA = machine.PB3 // pin 11 on the Uno
+	pinB = machine.PD3 // pin 3 on the Uno
+)

src/examples/pwm/feather-m4.go

@@ -0,0 +1,11 @@
+// +build feather_m4
+
+package main
+
+import "machine"
+
+var (
+	pwm  = machine.TCC0
+	pinA = machine.D12
+	pinB = machine.D13
+)

src/examples/pwm/itsybitsy-m0.go

@@ -0,0 +1,11 @@
+// +build itsybitsy_m0
+
+package main
+
+import "machine"
+
+var (
+	pwm  = machine.TCC0
+	pinA = machine.D3
+	pinB = machine.D4
+)

src/examples/pwm/itsybitsy-m4.go

@@ -0,0 +1,11 @@
+// +build itsybitsy_m4
+
+package main
+
+import "machine"
+
+var (
+	pwm  = machine.TCC0
+	pinA = machine.D12
+	pinB = machine.D13
+)

src/examples/pwm/pwm.go

@@ -1,64 +1,74 @@
 package main
 
+// This example demonstrates some features of the PWM support.
+
 import (
 	"machine"
 	"time"
 )
 
-// This example assumes that an RGB LED is connected to pins 3, 5 and 6 on an Arduino.
-// Change the values below to use different pins.
-const (
-	redPin   = machine.D4
-	greenPin = machine.D5
-	bluePin  = machine.D6
-)
-
-// cycleColor is just a placeholder until math/rand or some equivalent is working.
-func cycleColor(color uint8) uint8 {
-	if color < 10 {
-		return color + 1
-	} else if color < 200 {
-		return color + 10
-	} else {
-		return 0
-	}
-}
+const delayBetweenPeriods = time.Second * 5
 
 func main() {
-	machine.InitPWM()
+	// Delay a bit on startup to easily catch the first messages.
+	time.Sleep(time.Second * 2)
 
-	red := machine.PWM{redPin}
-	err := red.Configure()
-	checkError(err, "failed to configure red pin")
+	// Configure the PWM with the given period.
+	err := pwm.Configure(machine.PWMConfig{
+		Period: 16384e3, // 16.384ms
+	})
+	if err != nil {
+		println("failed to configure PWM")
+		return
+	}
 
-	green := machine.PWM{greenPin}
-	err = green.Configure()
-	checkError(err, "failed to configure green pin")
+	// The top value is the highest value that can be passed to PWMChannel.Set.
+	// It is usually an even number.
+	println("top:", pwm.Top())
 
-	blue := machine.PWM{bluePin}
-	err = blue.Configure()
-	checkError(err, "failed to configure blue pin")
+	// Configure the two channels we'll use as outputs.
+	channelA, err := pwm.Channel(pinA)
+	if err != nil {
+		println("failed to configure channel A")
+		return
+	}
+	channelB, err := pwm.Channel(pinB)
+	if err != nil {
+		println("failed to configure channel B")
+		return
+	}
 
-	var rc uint8
-	var gc uint8 = 20
-	var bc uint8 = 30
+	// Invert one of the channels to demonstrate output polarity.
+	pwm.SetInverting(channelB, true)
+
+	// Test out various frequencies below, including some edge cases.
+
+	println("running at 0% duty cycle")
+	pwm.Set(channelA, 0)
+	pwm.Set(channelB, 0)
+	time.Sleep(delayBetweenPeriods)
+
+	println("running at 1")
+	pwm.Set(channelA, 1)
+	pwm.Set(channelB, 1)
+	time.Sleep(delayBetweenPeriods)
+
+	println("running at 25% duty cycle")
+	pwm.Set(channelA, pwm.Top()/4)
+	pwm.Set(channelB, pwm.Top()/4)
+	time.Sleep(delayBetweenPeriods)
+
+	println("running at top-1")
+	pwm.Set(channelA, pwm.Top()-1)
+	pwm.Set(channelB, pwm.Top()-1)
+	time.Sleep(delayBetweenPeriods)
+
+	println("running at 100% duty cycle")
+	pwm.Set(channelA, pwm.Top())
+	pwm.Set(channelB, pwm.Top())
+	time.Sleep(delayBetweenPeriods)
 
 	for {
-		rc = cycleColor(rc)
-		gc = cycleColor(gc)
-		bc = cycleColor(bc)
-
-		red.Set(uint16(rc) << 8)
-		green.Set(uint16(gc) << 8)
-		blue.Set(uint16(bc) << 8)
-
-		time.Sleep(time.Millisecond * 500)
-	}
-}
-
-func checkError(err error, msg string) {
-	if err != nil {
-		print(msg, ": ", err.Error())
-		println()
+		time.Sleep(time.Second)
 	}
 }

src/internal/task/task_coroutine.go

@@ -11,7 +11,7 @@ import (
 type rawState uint8
 
 //export llvm.coro.resume
-func (s *rawState) resume()
+func coroResume(*rawState)
 
 type state struct{ *rawState }
 
@@ -20,7 +20,7 @@ func noopState() *rawState
 
 // Resume the task until it pauses or completes.
 func (t *Task) Resume() {
-	t.state.resume()
+	coroResume(t.state.rawState)
 }
 
 // setState is used by the compiler to set the state of the function at the beginning of a function call.
@@ -77,22 +77,9 @@ func Current() *Task
 // This is implemented inside the compiler.
 func Pause()
 
-type taskHolder interface {
-	setState(*rawState) *rawState
-	returnTo(*rawState)
-	returnCurrent()
-	setReturnPtr(unsafe.Pointer)
-	getReturnPtr() unsafe.Pointer
-}
-
-// If there are no direct references to the task methods, they will not be discovered by the compiler, and this will trigger a compiler error.
-// Instantiating this interface forces discovery of these methods.
-var _ = taskHolder((*Task)(nil))
-
 func fake() {
 	// Hack to ensure intrinsics are discovered.
 	Current()
-	go func() {}()
 	Pause()
 }
 

src/machine/adc.go

@@ -0,0 +1,12 @@
+package machine
+
+// Hardware abstraction layer for the analog-to-digital conversion (ADC)
+// peripheral.
+
+// ADCConfig holds ADC configuration parameters. If left unspecified, the zero
+// value of each parameter will use the peripheral's default settings.
+type ADCConfig struct {
+	Reference  uint32 // analog reference voltage (AREF) in millivolts
+	Resolution uint32 // number of bits for a single conversion (e.g., 8, 10, 12)
+	Samples    uint32 // number of samples for a single conversion (e.g., 4, 8, 16, 32)
+}

src/machine/board_arduino_mega1280.go

@@ -0,0 +1,104 @@
+// +build arduino_mega1280
+
+package machine
+
+// Return the current CPU frequency in hertz.
+func CPUFrequency() uint32 {
+	return 16000000
+}
+
+const (
+	AREF Pin = NoPin
+	LED  Pin = PB7
+
+	A0  Pin = PF0
+	A1  Pin = PF1
+	A2  Pin = PF2
+	A3  Pin = PF3
+	A4  Pin = PF4
+	A5  Pin = PF5
+	A6  Pin = PF6
+	A7  Pin = PF7
+	A8  Pin = PK0
+	A9  Pin = PK1
+	A10 Pin = PK2
+	A11 Pin = PK3
+	A12 Pin = PK4
+	A13 Pin = PK5
+	A14 Pin = PK6
+	A15 Pin = PK7
+
+	// Analog Input
+	ADC0  Pin = PF0
+	ADC1  Pin = PF1
+	ADC2  Pin = PF2
+	ADC3  Pin = PF3
+	ADC4  Pin = PF4
+	ADC5  Pin = PF5
+	ADC6  Pin = PF6
+	ADC7  Pin = PF7
+	ADC8  Pin = PK0
+	ADC9  Pin = PK1
+	ADC10 Pin = PK2
+	ADC11 Pin = PK3
+	ADC12 Pin = PK4
+	ADC13 Pin = PK5
+	ADC14 Pin = PK6
+	ADC15 Pin = PK7
+
+	// Digital pins
+	D0  Pin = PE0
+	D1  Pin = PE1
+	D2  Pin = PE4
+	D3  Pin = PE5
+	D4  Pin = PG5
+	D5  Pin = PE3
+	D6  Pin = PH3
+	D7  Pin = PH4
+	D8  Pin = PH5
+	D9  Pin = PH6
+	D10 Pin = PB4
+	D11 Pin = PB5
+	D12 Pin = PB6
+	D13 Pin = PB7
+	D14 Pin = PJ1
+	D15 Pin = PJ0
+	D16 Pin = PH1
+	D17 Pin = PH0
+	D18 Pin = PD3
+	D19 Pin = PD2
+	D20 Pin = PD1
+	D21 Pin = PD0
+	D22 Pin = PA0
+	D23 Pin = PA1
+	D24 Pin = PA2
+	D25 Pin = PA3
+	D26 Pin = PA4
+	D27 Pin = PA5
+	D28 Pin = PA6
+	D29 Pin = PA7
+	D30 Pin = PC7
+	D31 Pin = PC6
+	D32 Pin = PC5
+	D33 Pin = PC4
+	D34 Pin = PC3
+	D35 Pin = PC2
+	D36 Pin = PC1
+	D37 Pin = PC0
+	D38 Pin = PD7
+	D39 Pin = PG2
+	D40 Pin = PG1
+	D41 Pin = PG0
+	D42 Pin = PL7
+	D43 Pin = PL6
+	D44 Pin = PL5
+	D45 Pin = PL4
+	D46 Pin = PL3
+	D47 Pin = PL2
+	D48 Pin = PL1
+	D49 Pin = PL0
+	D50 Pin = PB3
+	D51 Pin = PB2
+	D52 Pin = PB1
+	D53 Pin = PB0
+)

src/machine/board_arduino_nano33_baremetal.go

@@ -32,7 +32,7 @@ func init() {
 
 // I2C on the Arduino Nano 33.
 var (
-	I2C0 = I2C{
+	I2C0 = &I2C{
 		Bus:    sam.SERCOM4_I2CM,
 		SERCOM: 4,
 	}

src/machine/board_atsame54-xpro.go

@@ -0,0 +1,330 @@
+// +build atsame54_xpro
+
+package machine
+
+import (
+	"device/sam"
+	"runtime/interrupt"
+)
+
+// Definition for compatibility, but not used
+const RESET_MAGIC_VALUE = 0x00000000
+
+const (
+	LED    = PC18
+	BUTTON = PB31
+)
+
+const (
+	// https://ww1.microchip.com/downloads/en/DeviceDoc/70005321A.pdf
+
+	// Extension Header EXT1
+	EXT1_PIN3_ADC_P     = PB04
+	EXT1_PIN4_ADC_N     = PB05
+	EXT1_PIN5_GPIO1     = PA06
+	EXT1_PIN6_GPIO2     = PA07
+	EXT1_PIN7_PWM_P     = PB08
+	EXT1_PIN8_PWM_N     = PB09
+	EXT1_PIN9_IRQ       = PB07
+	EXT1_PIN9_GPIO      = PB07
+	EXT1_PIN10_SPI_SS_B = PA27
+	EXT1_PIN10_GPIO     = PA27
+	EXT1_PIN11_TWI_SDA  = PA22
+	EXT1_PIN12_TWI_SCL  = PA23
+	EXT1_PIN13_UART_RX  = PA05
+	EXT1_PIN14_UART_TX  = PA04
+	EXT1_PIN15_SPI_SS_A = PB28
+	EXT1_PIN16_SPI_SDO  = PB27
+	EXT1_PIN17_SPI_SDI  = PB29
+	EXT1_PIN18_SPI_SCK  = PB26
+
+	// Extension Header EXT2
+	EXT2_PIN3_ADC_P     = PB00
+	EXT2_PIN4_ADC_N     = PA03
+	EXT2_PIN5_GPIO1     = PB01
+	EXT2_PIN6_GPIO2     = PB06
+	EXT2_PIN7_PWM_P     = PB14
+	EXT2_PIN8_PWM_N     = PB15
+	EXT2_PIN9_IRQ       = PD00
+	EXT2_PIN9_GPIO      = PD00
+	EXT2_PIN10_SPI_SS_B = PB02
+	EXT2_PIN10_GPIO     = PB02
+	EXT2_PIN11_TWI_SDA  = PD08
+	EXT2_PIN12_TWI_SCL  = PD09
+	EXT2_PIN13_UART_RX  = PB17
+	EXT2_PIN14_UART_TX  = PB16
+	EXT2_PIN15_SPI_SS_A = PC06
+	EXT2_PIN16_SPI_SDO  = PC04
+	EXT2_PIN17_SPI_SDI  = PC07
+	EXT2_PIN18_SPI_SCK  = PC05
+
+	// Extension Header EXT3
+	EXT3_PIN3_ADC_P     = PC02
+	EXT3_PIN4_ADC_N     = PC03
+	EXT3_PIN5_GPIO1     = PC01
+	EXT3_PIN6_GPIO2     = PC10
+	EXT3_PIN7_PWM_P     = PD10
+	EXT3_PIN8_PWM_N     = PD11
+	EXT3_PIN9_IRQ       = PC30
+	EXT3_PIN9_GPIO      = PC30
+	EXT3_PIN10_SPI_SS_B = PC31
+	EXT3_PIN10_GPIO     = PC31
+	EXT3_PIN11_TWI_SDA  = PD08
+	EXT3_PIN12_TWI_SCL  = PD09
+	EXT3_PIN13_UART_RX  = PC23
+	EXT3_PIN14_UART_TX  = PC22
+	EXT3_PIN15_SPI_SS_A = PC14
+	EXT3_PIN16_SPI_SDO  = PC04
+	EXT3_PIN17_SPI_SDI  = PC07
+	EXT3_PIN18_SPI_SCK  = PC05
+
+	// SD_CARD
+	SD_CARD_MCDA0   = PB18
+	SD_CARD_MCDA1   = PB19
+	SD_CARD_MCDA2   = PB20
+	SD_CARD_MCDA3   = PB21
+	SD_CARD_MCCK    = PA21
+	SD_CARD_MCCDA   = PA20
+	SD_CARD_DETECT  = PD20
+	SD_CARD_PROTECT = PD21
+
+	// I2C
+	I2C_SDA = PD08
+	I2C_SCL = PD09
+
+	// CAN
+	CAN0_TX = PA22
+	CAN0_RX = PA23
+
+	CAN1_STANDBY = PC13
+	CAN1_TX      = PB12
+	CAN1_RX      = PB13
+
+	CAN_STANDBY = CAN1_STANDBY
+	CAN_TX      = CAN1_TX
+	CAN_RX      = CAN1_RX
+
+	// PDEC
+	PDEC_PHASE_A = PC16
+	PDEC_PHASE_B = PC17
+	PDEC_INDEX   = PC18
+
+	// PCC
+	PCC_I2C_SDA    = PD08
+	PCC_I2C_SCL    = PD09
+	PCC_VSYNC_DEN1 = PA12
+	PCC_HSYNC_DEN2 = PA13
+	PCC_CLK        = PA14
+	PCC_XCLK       = PA15
+	PCC_DATA00     = PA16
+	PCC_DATA01     = PA17
+	PCC_DATA02     = PA18
+	PCC_DATA03     = PA19
+	PCC_DATA04     = PA20
+	PCC_DATA05     = PA21
+	PCC_DATA06     = PA22
+	PCC_DATA07     = PA23
+	PCC_DATA08     = PB14
+	PCC_DATA09     = PB15
+	PCC_RESET      = PC12
+	PCC_PWDN       = PC11
+
+	// Ethernet
+	ETHERNET_TXCK  = PA14
+	ETHERNET_TXEN  = PA17
+	ETHERNET_TX0   = PA18
+	ETHERNET_TX1   = PA19
+	ETHERNET_RXER  = PA15
+	ETHERNET_RX0   = PA13
+	ETHERNET_RX1   = PA12
+	ETHERNET_RXDV  = PC20
+	ETHERNET_MDIO  = PC12
+	ETHERNET_MDC   = PC11
+	ETHERNET_INT   = PD12
+	ETHERNET_RESET = PC21
+
+	PIN_QT_BUTTON   = PA16
+	PIN_BTN0        = PB31
+	PIN_ETH_LED     = PC15
+	PIN_LED0        = PC18
+	PIN_ADC_DAC     = PA02
+	PIN_VBUS_DETECT = PC00
+	PIN_USB_ID      = PC19
+)
+
+// UART0 aka USBCDC pins
+const (
+	USBCDC_DM_PIN = PA24
+	USBCDC_DP_PIN = PA25
+)
+
+// UART pins
+const (
+	// Extension Header EXT1
+	UART_TX_PIN = PA04 // TX : SERCOM0/PAD[0]
+	UART_RX_PIN = PA05 // RX : SERCOM0/PAD[1]
+
+	// Extension Header EXT2
+	UART2_TX_PIN = PB16 // TX : SERCOM5/PAD[0]
+	UART2_RX_PIN = PB17 // RX : SERCOM5/PAD[1]
+
+	// Extension Header EXT3
+	UART3_TX_PIN = PC22 // TX : SERCOM1/PAD[0]
+	UART3_RX_PIN = PC23 // RX : SERCOM1/PAD[1]
+
+	// Virtual COM Port
+	UART4_TX_PIN = PB25 // TX : SERCOM2/PAD[0]
+	UART4_RX_PIN = PB24 // RX : SERCOM2/PAD[1]
+)
+
+// I2C pins
+const (
+	// Extension Header EXT1
+	SDA0_PIN = PA22 // SDA: SERCOM3/PAD[0]
+	SCL0_PIN = PA23 // SCL: SERCOM3/PAD[1]
+
+	// Extension Header EXT2
+	SDA1_PIN = PD08 // SDA: SERCOM7/PAD[0]
+	SCL1_PIN = PD09 // SCL: SERCOM7/PAD[1]
+
+	// Extension Header EXT3
+	SDA2_PIN = PD08 // SDA: SERCOM7/PAD[0]
+	SCL2_PIN = PD09 // SCL: SERCOM7/PAD[1]
+
+	// Data Gateway Interface
+	SDA_DGI_PIN = PD08 // SDA: SERCOM7/PAD[0]
+	SCL_DGI_PIN = PD09 // SCL: SERCOM7/PAD[1]
+
+	SDA_PIN = SDA0_PIN
+	SCL_PIN = SCL0_PIN
+)
+
+// SPI pins
+const (
+	// Extension Header EXT1
+	SPI0_SCK_PIN = PB26 // SCK: SERCOM4/PAD[1]
+	SPI0_SDO_PIN = PB27 // SDO: SERCOM4/PAD[0]
+	SPI0_SDI_PIN = PB29 // SDI: SERCOM4/PAD[3]
+	SPI0_SS_PIN  = PB28 // SS : SERCOM4/PAD[2]
+
+	// Extension Header EXT2
+	SPI1_SCK_PIN = PC05 // SCK: SERCOM6/PAD[1]
+	SPI1_SDO_PIN = PC04 // SDO: SERCOM6/PAD[0]
+	SPI1_SDI_PIN = PC07 // SDI: SERCOM6/PAD[3]
+	SPI1_SS_PIN  = PC06 // SS : SERCOM6/PAD[2]
+
+	// Extension Header EXT3
+	SPI2_SCK_PIN = PC05 // SCK: SERCOM6/PAD[1]
+	SPI2_SDO_PIN = PC04 // SDO: SERCOM6/PAD[0]
+	SPI2_SDI_PIN = PC07 // SDI: SERCOM6/PAD[3]
+	SPI2_SS_PIN  = PC14 // SS : GPIO
+
+	// Data Gateway Interface
+	SPI_DGI_SCK_PIN = PC05 // SCK: SERCOM6/PAD[1]
+	SPI_DGI_SDO_PIN = PC04 // SDO: SERCOM6/PAD[0]
+	SPI_DGI_SDI_PIN = PC07 // SDI: SERCOM6/PAD[3]
+	SPI_DGI_SS_PIN  = PD01 // SS : GPIO
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "SAM E54 Xplained Pro"
+	usb_STRING_MANUFACTURER = "Atmel"
+)
+
+var (
+	usb_VID uint16 = 0x03EB
+	usb_PID uint16 = 0x2404
+)
+
+// UART on the SAM E54 Xplained Pro
+var (
+	// Extension Header EXT1
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM0_USART_INT,
+		SERCOM: 0,
+	}
+
+	// Extension Header EXT2
+	UART2 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM5_USART_INT,
+		SERCOM: 5,
+	}
+
+	// Extension Header EXT3
+	UART3 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM1_USART_INT,
+		SERCOM: 1,
+	}
+
+	// EDBG Virtual COM Port
+	UART4 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM2_USART_INT,
+		SERCOM: 2,
+	}
+)
+
+func init() {
+	UART1.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(sam.IRQ_SERCOM5_2, UART2.handleInterrupt)
+	UART3.Interrupt = interrupt.New(sam.IRQ_SERCOM1_2, UART3.handleInterrupt)
+	UART4.Interrupt = interrupt.New(sam.IRQ_SERCOM2_2, UART4.handleInterrupt)
+}
+
+// I2C on the SAM E54 Xplained Pro
+var (
+	// Extension Header EXT1
+	I2C0 = I2C{
+		Bus:    sam.SERCOM3_I2CM,
+		SERCOM: 3,
+	}
+
+	// Extension Header EXT2
+	I2C1 = I2C{
+		Bus:    sam.SERCOM7_I2CM,
+		SERCOM: 7,
+	}
+
+	// Extension Header EXT3
+	I2C2 = I2C{
+		Bus:    sam.SERCOM7_I2CM,
+		SERCOM: 7,
+	}
+
+	// Data Gateway Interface
+	I2C3 = I2C{
+		Bus:    sam.SERCOM7_I2CM,
+		SERCOM: 7,
+	}
+)
+
+// SPI on the SAM E54 Xplained Pro
+var (
+	// Extension Header EXT1
+	SPI0 = SPI{
+		Bus:    sam.SERCOM4_SPIM,
+		SERCOM: 4,
+	}
+
+	// Extension Header EXT2
+	SPI1 = SPI{
+		Bus:    sam.SERCOM6_SPIM,
+		SERCOM: 6,
+	}
+
+	// Extension Header EXT3
+	SPI2 = SPI{
+		Bus:    sam.SERCOM6_SPIM,
+		SERCOM: 6,
+	}
+
+	// Data Gateway Interface
+	SPI3 = SPI{
+		Bus:    sam.SERCOM6_SPIM,
+		SERCOM: 6,
+	}
+)

src/machine/board_bluepill.go

@@ -85,6 +85,6 @@ const (
 
 // I2C pins
 const (
-	SDA_PIN = PB7
-	SCL_PIN = PB6
+	I2C0_SDA_PIN = PB7
+	I2C0_SCL_PIN = PB6
 )

src/machine/board_circuitplay_bluefruit.go

@@ -66,8 +66,8 @@ const (
 	SDA_PIN = P0_05 // I2C0 external
 	SCL_PIN = P0_04 // I2C0 external
 
-	SDA1_PIN = P0_00 // I2C1 internal
-	SCL1_PIN = P0_01 // I2C1 internal
+	SDA1_PIN = P1_10 // I2C1 internal
+	SCL1_PIN = P1_12 // I2C1 internal
 )
 
 // SPI pins (internal flash)

src/machine/board_circuitplay_express.go

@@ -25,8 +25,8 @@ const (
 
 // Analog Pins
 const (
-	A0  = PA02 // PWM available, also ADC/AIN[0]
-	A1  = PA05 // ADC/AIN[5]
+	A0  = PA02 // ADC/AIN[0]
+	A1  = PA05 // PWM available, also ADC/AIN[5]
 	A2  = PA06 // PWM available, also ADC/AIN[6]
 	A3  = PA07 // PWM available, also ADC/AIN[7]
 	A4  = PB03 // PORTB

src/machine/board_circuitplay_express_baremetal.go

@@ -23,12 +23,12 @@ func init() {
 // I2C on the Circuit Playground Express.
 var (
 	// external device
-	I2C0 = I2C{
+	I2C0 = &I2C{
 		Bus:    sam.SERCOM5_I2CM,
 		SERCOM: 5,
 	}
 	// internal device
-	I2C1 = I2C{
+	I2C1 = &I2C{
 		Bus:    sam.SERCOM1_I2CM,
 		SERCOM: 1,
 	}