all: release v0.23.0

testdata: move map growth test to map.go
src/runtime: return a nil pointer for compiler bugs in hashmap code
2026-07-30 08:38:41 +00:00 · 2022-04-28 17:51:09 +02:00 · 2022-04-28 09:14:45 +02:00 · 2022-04-28 09:14:45 +02:00 · 2022-04-28 09:14:45 +02:00 · 2022-04-28 09:14:45 +02:00
454 changed files with 7646 additions and 1140 deletions
@@ -22,15 +22,16 @@ commands:
    steps:
      - restore_cache:
          keys:
-            - llvm-source-13-v1
+            - llvm-source-14-v1
      - run:
          name: "Fetch LLVM source"
          command: make llvm-source
      - save_cache:
-          key: llvm-source-13-v1
+          key: llvm-source-14-v1
          paths:
            - llvm-project/clang/lib/Headers
            - llvm-project/clang/include
+            - llvm-project/compiler-rt
            - llvm-project/lld/include
            - llvm-project/llvm/include
  hack-ninja-jobs:
@@ -85,10 +86,10 @@ commands:
      - run: go install -tags=llvm<<parameters.llvm>> .
      - restore_cache:
          keys:
-            - wasi-libc-sysroot-systemclang-v3
+            - wasi-libc-sysroot-systemclang-v5
      - run: make wasi-libc
      - save_cache:
-          key: wasi-libc-sysroot-systemclang-v3
+          key: wasi-libc-sysroot-systemclang-v5
          paths:
            - lib/wasi-libc/sysroot
      - run: make gen-device -j4
@@ -107,9 +108,9 @@ jobs:
    steps:
      - test-linux:
          llvm: "11"
-  test-llvm12-go116:
+  test-llvm12-go117:
    docker:
-      - image: circleci/golang:1.16-buster
+      - image: circleci/golang:1.17-buster
    steps:
      - test-linux:
          llvm: "12"
@@ -118,4 +119,4 @@ workflows:
  test-all:
    jobs:
      - test-llvm11-go115
-      - test-llvm12-go116
+      - test-llvm12-go117
@@ -10,12 +10,12 @@ on:
 jobs:
  build-macos:
    name: build-macos
-    runs-on: macos-10.15
+    runs-on: macos-11
    steps:
      - name: Install Go
        uses: actions/setup-go@v2
        with:
-          go-version: '1.17'
+          go-version: '1.18.1'
      - name: Install Dependencies
        shell: bash
        run: |
@@ -35,10 +35,11 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-source
        with:
-          key: llvm-source-13-macos-v1
+          key: llvm-source-14-macos-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
+            llvm-project/compiler-rt
            llvm-project/lld/include
            llvm-project/llvm/include
      - name: Download LLVM source
@@ -48,7 +49,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-build
        with:
-          key: llvm-build-13-macos-v2
+          key: llvm-build-14-macos-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -66,7 +67,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-wasi-libc
        with:
-          key: wasi-libc-sysroot-v1
+          key: wasi-libc-sysroot-v3
          path: lib/wasi-libc/sysroot
      - name: Build wasi-libc
        if: steps.cache-wasi-libc.outputs.cache-hit != 'true'
@@ -76,6 +77,8 @@ jobs:
        run: make test GOTESTFLAGS="-v -short"
      - name: Build TinyGo release tarball
        run: make release -j3
+      - name: Test stdlib packages
+        run: make tinygo-test
      - name: Make release artifact
        shell: bash
        run: cp -p build/release.tar.gz build/tinygo.darwin-amd64.tar.gz 
@@ -57,3 +57,27 @@ jobs:
            --header 'Content-Type: application/json' \
            -d '{"branch": "dev"}' \
            -u "${{ secrets.CIRCLECI_API_TOKEN }}"
+      - name: Trigger Bluetooth repo build on CircleCI
+        run: |
+          curl --location --request POST 'https://circleci.com/api/v2/project/github/tinygo-org/bluetooth/pipeline' \
+            --header 'Content-Type: application/json' \
+            -d '{"branch": "dev"}' \
+            -u "${{ secrets.CIRCLECI_API_TOKEN }}"
+      - name: Trigger TinyFS repo build on CircleCI
+        run: |
+          curl --location --request POST 'https://circleci.com/api/v2/project/github/tinygo-org/tinyfs/pipeline' \
+            --header 'Content-Type: application/json' \
+            -d '{"branch": "dev"}' \
+            -u "${{ secrets.CIRCLECI_API_TOKEN }}"
+      - name: Trigger TinyFont repo build on CircleCI
+        run: |
+          curl --location --request POST 'https://circleci.com/api/v2/project/github/tinygo-org/tinyfont/pipeline' \
+            --header 'Content-Type: application/json' \
+            -d '{"branch": "dev"}' \
+            -u "${{ secrets.CIRCLECI_API_TOKEN }}"
+      - name: Trigger TinyDraw repo build on CircleCI
+        run: |
+          curl --location --request POST 'https://circleci.com/api/v2/project/github/tinygo-org/tinydraw/pipeline' \
+            --header 'Content-Type: application/json' \
+            -d '{"branch": "dev"}' \
+            -u "${{ secrets.CIRCLECI_API_TOKEN }}"
@@ -26,7 +26,7 @@ jobs:
      - name: Install Go
        uses: actions/setup-go@v2
        with:
-          go-version: '1.17'
+          go-version: '1.18.1'
      - name: Cache Go
        uses: actions/cache@v2
        with:
@@ -38,10 +38,11 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-source
        with:
-          key: llvm-source-13-linux-v1
+          key: llvm-source-14-linux-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
+            llvm-project/compiler-rt
            llvm-project/lld/include
            llvm-project/llvm/include
      - name: Download LLVM source
@@ -51,7 +52,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-build
        with:
-          key: llvm-build-13-linux-v1
+          key: llvm-build-14-linux-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -76,14 +77,13 @@ jobs:
        uses: actions/cache@v2
        id: cache-wasi-libc
        with:
-          key: wasi-libc-sysroot-linux-asserts-v2
+          key: wasi-libc-sysroot-linux-asserts-v4
          path: lib/wasi-libc/sysroot
      - name: Build wasi-libc
        if: steps.cache-wasi-libc.outputs.cache-hit != 'true'
        run: make wasi-libc
      - name: Install fpm
        run: |
-          sudo apt-get install ruby ruby-dev
          sudo gem install --no-document fpm
      - name: Build TinyGo release
        run: |
@@ -93,7 +93,7 @@ jobs:
      - name: Publish release artifact
        uses: actions/upload-artifact@v2
        with:
-          name: release-double-zipped
+          name: linux-amd64-double-zipped
          path: |
            /tmp/tinygo.linux-amd64.tar.gz
            /tmp/tinygo_amd64.deb
@@ -107,7 +107,7 @@ jobs:
      - name: Install Go
        uses: actions/setup-go@v2
        with:
-          go-version: '1.17'
+          go-version: '1.18.1'
      - name: Install wasmtime
        run: |
          curl https://wasmtime.dev/install.sh -sSf | bash
@@ -115,7 +115,7 @@ jobs:
      - name: Download release artifact
        uses: actions/download-artifact@v2
        with:
-          name: release-double-zipped
+          name: linux-amd64-double-zipped
      - name: Extract release tarball
        run: |
          mkdir -p ~/lib
@@ -159,7 +159,7 @@ jobs:
      - name: Install Go
        uses: actions/setup-go@v2
        with:
-          go-version: '1.17'
+          go-version: '1.18.1'
      - name: Install Node.js
        uses: actions/setup-node@v2
        with:
@@ -179,10 +179,11 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-source
        with:
-          key: llvm-source-13-linux-asserts-v1
+          key: llvm-source-14-linux-asserts-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
+            llvm-project/compiler-rt
            llvm-project/lld/include
            llvm-project/llvm/include
      - name: Download LLVM source
@@ -192,7 +193,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-build
        with:
-          key: llvm-build-13-linux-asserts-v1
+          key: llvm-build-14-linux-asserts-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -217,7 +218,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-wasi-libc
        with:
-          key: wasi-libc-sysroot-linux-asserts-v2
+          key: wasi-libc-sysroot-linux-asserts-v4
          path: lib/wasi-libc/sysroot
      - name: Build wasi-libc
        if: steps.cache-wasi-libc.outputs.cache-hit != 'true'
@@ -239,3 +240,109 @@ jobs:
          rm xtensa-esp32-elf-gcc8_2_0-esp-2020r2-linux-amd64.tar.gz
      - run: make smoketest
      - run: make wasmtest
+      - run: make tinygo-baremetal
+  build-linux-arm:
+    # Build ARM Linux binaries, ready for release.
+    # This intentionally uses an older Linux image, so that we compile against
+    # an older glibc version and therefore are compatible with a wide range of
+    # Linux distributions.
+    # It is set to "needs: build-linux" because it modifies the release created
+    # in that process to avoid doing lots of duplicate work and to avoid
+    # complications around precompiled libraries such as compiler-rt shipped as
+    # part of the release tarball.
+    runs-on: ubuntu-18.04
+    needs: build-linux
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install apt dependencies
+        run: |
+          sudo apt-get install --no-install-recommends \
+              qemu-user \
+              g++-arm-linux-gnueabihf \
+              libc6-dev-armhf-cross
+      - name: Install Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: '1.17'
+      - name: Cache Go
+        uses: actions/cache@v2
+        with:
+          key: go-cache-linux-arm-v2-${{ hashFiles('go.mod') }}
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+      - name: Cache LLVM source
+        uses: actions/cache@v2
+        id: cache-llvm-source
+        with:
+          key: llvm-source-14-linux-v1
+          path: |
+            llvm-project/clang/lib/Headers
+            llvm-project/clang/include
+            llvm-project/compiler-rt
+            llvm-project/lld/include
+            llvm-project/llvm/include
+      - name: Download LLVM source
+        if: steps.cache-llvm-source.outputs.cache-hit != 'true'
+        run: make llvm-source
+      - name: Cache LLVM build
+        uses: actions/cache@v2
+        id: cache-llvm-build
+        with:
+          key: llvm-build-14-linux-arm-v1
+          path: llvm-build
+      - name: Build LLVM
+        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
+        run: |
+          # fetch LLVM source
+          rm -rf llvm-project
+          make llvm-source
+          # Install build dependencies.
+          sudo apt-get install --no-install-recommends ninja-build
+          # build!
+          make llvm-build CROSS=arm-linux-gnueabihf
+          # Remove unnecessary object files (to reduce cache size).
+          find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
+      - name: Cache Binaryen
+        uses: actions/cache@v2
+        id: cache-binaryen
+        with:
+          key: binaryen-linux-arm-v1
+          path: build/wasm-opt
+      - name: Build Binaryen
+        if: steps.cache-binaryen.outputs.cache-hit != 'true'
+        run: |
+          sudo apt-get install --no-install-recommends ninja-build
+          git submodule update --init lib/binaryen
+          make CROSS=arm-linux-gnueabihf binaryen
+      - name: Install fpm
+        run: |
+          sudo gem install --no-document fpm
+      - name: Build TinyGo binary
+        run: |
+          make CROSS=arm-linux-gnueabihf
+      - name: Download amd64 release
+        uses: actions/download-artifact@v2
+        with:
+          name: linux-amd64-double-zipped
+      - name: Extract amd64 release
+        run: |
+          mkdir -p build/release
+          tar -xf tinygo.linux-amd64.tar.gz -C build/release tinygo
+      - name: Modify release
+        run: |
+          cp -p build/tinygo   build/release/tinygo/bin
+          cp -p build/wasm-opt build/release/tinygo/bin
+      - name: Create arm release
+        run: |
+          make release deb RELEASEONLY=1 DEB_ARCH=armhf
+          cp -p build/release.tar.gz /tmp/tinygo.linux-arm.tar.gz
+          cp -p build/release.deb    /tmp/tinygo_armhf.deb
+      - name: Publish release artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: linux-arm-double-zipped
+          path: |
+            /tmp/tinygo.linux-arm.tar.gz
+            /tmp/tinygo_armhf.deb
@@ -9,13 +9,13 @@ on:

 jobs:
  build-windows:
-    runs-on: windows-2019
+    runs-on: windows-2022
    steps:
      - name: Install Go
        uses: actions/setup-go@v2
        with:
-          go-version: '1.17'
-      - uses: MinoruSekine/setup-scoop@v1
+          go-version: '1.18.1'
+      - uses: brechtm/setup-scoop@v2
      - name: Install Dependencies
        shell: bash
        run: |
@@ -35,10 +35,11 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-source
        with:
-          key: llvm-source-13-windows-v1
+          key: llvm-source-14-windows-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
+            llvm-project/compiler-rt
            llvm-project/lld/include
            llvm-project/llvm/include
      - name: Download LLVM source
@@ -48,7 +49,7 @@ jobs:
        uses: actions/cache@v2
        id: cache-llvm-build
        with:
-          key: llvm-build-13-windows-v1
+          key: llvm-build-14-windows-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -65,11 +66,14 @@ jobs:
        uses: actions/cache@v2
        id: cache-wasi-libc
        with:
-          key: wasi-libc-sysroot-v1
+          key: wasi-libc-sysroot-v3
          path: lib/wasi-libc/sysroot
      - name: Build wasi-libc
        if: steps.cache-wasi-libc.outputs.cache-hit != 'true'
        run: make wasi-libc
+      - name: Install wasmtime
+        run: |
+          scoop install wasmtime
      - name: Test TinyGo
        shell: bash
        run: make test GOTESTFLAGS="-v -short"
@@ -95,3 +99,5 @@ jobs:
        run: make smoketest TINYGO=$(PWD)/build/tinygo AVR=0 XTENSA=0
      - name: Test stdlib packages
        run: make tinygo-test
+      - name: Test stdlib packages on wasi
+        run: make tinygo-test-wasi-fast
@@ -10,10 +10,6 @@
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
 	url = https://github.com/tinygo-org/cmsis-svd
-[submodule "lib/compiler-rt"]
-	path = lib/compiler-rt
-	url = https://github.com/llvm-mirror/compiler-rt.git
-	branch = release_80
 [submodule "lib/wasi-libc"]
 	path = lib/wasi-libc
 	url = https://github.com/CraneStation/wasi-libc
@@ -32,3 +28,6 @@
 [submodule "lib/mingw-w64"]
 	path = lib/mingw-w64
 	url = https://github.com/mingw-w64/mingw-w64.git
+[submodule "lib/macos-minimal-sdk"]
+	path = lib/macos-minimal-sdk
+	url = https://github.com/aykevl/macos-minimal-sdk.git
@@ -1,3 +1,101 @@
+0.23.0
+---
+
+* **command line**
+  - add `-work` flag
+  - add Go 1.18 support
+  - add LLVM 14 support
+  - `run`: add support for command-line parameters
+  - `build`: calculate default output path if `-o` is not specified
+  - `build`: add JSON output
+  - `test`: support multiple test binaries with `-c`
+  - `test`: support flags like `-v` on all targets (including emulated firmware)
+* **compiler**
+  - add support for ThinLTO
+  - use compiler-rt from LLVM
+  - `builder`: prefer GNU build ID over Go build ID for caching
+  - `builder`: add support for cross compiling to Darwin
+  - `builder`: support machine outlining pass in stacksize calculation
+  - `builder`: disable asynchronous unwind tables
+  - `compileopts`: fix emulator configuration on non-amd64 Linux architectures
+  - `compiler`: move allocations > 256  bytes to the heap
+  - `compiler`: fix incorrect `unsafe.Alignof` on some 32-bit architectures
+  - `compiler`: accept alias for slice `cap` builtin
+  - `compiler`: allow slices of empty structs
+  - `compiler`: fix difference in aliases in interface methods
+  - `compiler`: make `RawSyscall` an alias for `Syscall`
+  - `compiler`: remove support for memory references in `AsmFull`
+  - `loader`: only add Clang header path for CGo
+  - `transform`: fix poison value in heap-to-stack transform
+* **standard library**
+  - `internal/fuzz`: add this package as a shim
+  - `os`: implement readdir for darwin and linux
+  - `os`: add `DirFS`, which is used by many programs to access readdir.
+  - `os`: isWine: be compatible with older versions of wine, too
+  - `os`: implement `RemoveAll`
+  - `os`: Use a `uintptr` for `NewFile`
+  - `os`: add stubs for `exec.ExitError` and `ProcessState.ExitCode`
+  - `os`: export correct values for `DevNull` for each OS
+  - `os`: improve support for `Signal` by fixing various bugs
+  - `os`: implement `File.Fd` method
+  - `os`: implement `UserHomeDir`
+  - `os`: add `exec.ProcessState` stub
+  - `os`: implement `Pipe` for darwin
+  - `os`: define stub `ErrDeadlineExceeded`
+  - `reflect`: add stubs for more missing methods
+  - `reflect`: rename `reflect.Ptr` to `reflect.Pointer`
+  - `reflect`: add `Value.FieldByIndexErr` stub
+  - `runtime`: fix various small GC bugs
+  - `runtime`: use memzero for leaking collector instead of manually zeroing objects
+  - `runtime`: implement `memhash`
+  - `runtime`: implement `fastrand`
+  - `runtime`: add stub for `debug.ReadBuildInfo`
+  - `runtime`: add stub for `NumCPU`
+  - `runtime`: don't inline `runtime.alloc` with `-gc=leaking`
+  - `runtime`: add `Version`
+  - `runtime`: add stubs for `NumCgoCall` and `NumGoroutine`
+  - `runtime`: stub {Lock,Unlock}OSThread on Windows
+  - `runtime`: be able to deal with a very small heap
+  - `syscall`: make `Environ` return a copy of the environment
+  - `syscall`: implement getpagesize and munmap
+  - `syscall`: `wasi`: define `MAP_SHARED` and `PROT_READ`
+  - `syscall`: stub mmap(), munmap(), MAP_SHARED, PROT_READ, SIGBUS, etc. on nonhosted targets
+  - `syscall`: darwin: more complete list of signals
+  - `syscall`: `wasi`: more complete list of signals
+  - `syscall`: stub `WaitStatus`
+  - `syscall/js`: allow copyBytesTo(Go|JS) to use `Uint8ClampedArray`
+  - `testing`: implement `TempDir`
+  - `testing`: nudge type TB closer to upstream; should be a no-op change.
+  - `testing`: on baremetal platforms, use simpler test matcher
+* **targets**
+  - `atsamd`: fix usbcdc initialization when `-serial=uart`
+  - `atsamd51`: allow higher frequency when using SPI
+  - `esp`: support CGo
+  - `esp32c3`: add support for input pin
+  - `esp32c3`: add support for GPIO interrupts
+  - `esp32c3`: add support to receive UART data
+  - `rp2040`: fix PWM bug at high frequency
+  - `rp2040`: fix some minor I2C bugs
+  - `rp2040`: fix incorrect inline assembly
+  - `rp2040`: fix spurious i2c STOP during write+read transaction
+  - `rp2040`: improve ADC support
+  - `wasi`: remove `--export-dynamic` linker flag
+  - `wasm`: remove heap allocator from wasi-libc
+* **boards**
+  - `circuitplay-bluefruit`: move pin mappings so board can be compiled for WASM use in Playground
+  - `esp32-c3-12f`: add the ESP32-C3-12f Kit
+  - `m5stamp-c3`: add pin setting of UART
+  - `macropad-rp2040`: add the Adafruit MacroPad RP2040 board
+  - `nano-33-ble`: typo in LPS22HB peripheral definition and documentation (#2579)
+  - `teensy41`: add the Teensy 4.1 board
+  - `teensy40`: add ADC support
+  - `teensy40`: add SPI support
+  - `thingplus-rp2040`: add the SparkFun Thing Plus RP2040 board
+  - `wioterminal`: add DefaultUART
+  - `wioterminal`: verify written data when flashing through OpenOCD
+  - `xiao-ble`: add XIAO BLE nRF52840 support
+
+
 0.22.0
 ---

@@ -1,5 +1,5 @@
 # tinygo-llvm stage obtains the llvm source for TinyGo
-FROM golang:1.17 AS tinygo-llvm
+FROM golang:1.18 AS tinygo-llvm

 RUN apt-get update && \
    apt-get install -y apt-utils make cmake clang-11 binutils-avr gcc-avr avr-libc ninja-build
@@ -10,7 +10,7 @@ LLD_SRC ?= $(LLVM_PROJECTDIR)/lld

 # Try to autodetect LLVM build tools.
 # Versions are listed here in descending priority order.
-LLVM_VERSIONS = 13 12 11
+LLVM_VERSIONS = 14 13 12 11
 errifempty = $(if $(1),$(1),$(error $(2)))
 detect = $(shell which $(call errifempty,$(firstword $(foreach p,$(2),$(shell command -v $(p) 2> /dev/null && echo $(p)))),failed to locate $(1) at any of: $(2)))
 toolSearchPathsVersion = $(1)-$(2)
@@ -50,6 +50,29 @@ else
    LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=OFF'
 endif

+# Cross compiling support.
+ifneq ($(CROSS),)
+    CC = $(CROSS)-gcc
+    CXX = $(CROSS)-g++
+    LLVM_OPTION += \
+        -DCMAKE_C_COMPILER=$(CC) \
+        -DCMAKE_CXX_COMPILER=$(CXX) \
+        -DLLVM_DEFAULT_TARGET_TRIPLE=$(CROSS) \
+        -DCROSS_TOOLCHAIN_FLAGS_NATIVE="-UCMAKE_C_COMPILER;-UCMAKE_CXX_COMPILER"
+    ifeq ($(CROSS), arm-linux-gnueabihf)
+        # Assume we're building on a Debian-like distro, with QEMU installed.
+        LLVM_CONFIG_PREFIX = qemu-arm -L /usr/arm-linux-gnueabihf/
+        # The CMAKE_SYSTEM_NAME flag triggers cross compilation mode.
+        LLVM_OPTION += \
+            -DCMAKE_SYSTEM_NAME=Linux \
+            -DLLVM_TARGET_ARCH=ARM
+        GOENVFLAGS = GOARCH=arm CC=$(CC) CXX=$(CXX) CGO_ENABLED=1
+        BINARYEN_OPTION += -DCMAKE_C_COMPILER=$(CC) -DCMAKE_CXX_COMPILER=$(CXX)
+    else
+        $(error Unknown cross compilation target: $(CROSS))
+    endif
+endif
+
 .PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-nxp gen-device-avr gen-device-rp

 LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines coverage debuginfodwarf debuginfopdb executionengine frontendopenmp instrumentation interpreter ipo irreader libdriver linker lto mc mcjit objcarcopts option profiledata scalaropts support target windowsmanifest
@@ -73,6 +96,8 @@ ifeq ($(OS),Windows_NT)
 else ifeq ($(shell uname -s),Darwin)
    MD5SUM = md5

+    CGO_LDFLAGS += -lxar
+
    USE_SYSTEM_BINARYEN ?= 1

 else ifeq ($(shell uname -s),FreeBSD)
@@ -89,11 +114,11 @@ CLANG_LIB_NAMES = clangAnalysis clangAST clangASTMatchers clangBasic clangCodeGe
 CLANG_LIBS = $(START_GROUP) $(addprefix -l,$(CLANG_LIB_NAMES)) $(END_GROUP) -lstdc++

 # Libraries that should be linked in for the statically linked LLD.
-LLD_LIB_NAMES = lldCOFF lldCommon lldCore lldDriver lldELF lldMachO lldMinGW lldReaderWriter lldWasm lldYAML
+LLD_LIB_NAMES = lldCOFF lldCommon lldELF lldMachO lldMinGW lldWasm
 LLD_LIBS = $(START_GROUP) $(addprefix -l,$(LLD_LIB_NAMES)) $(END_GROUP)

 # Other libraries that are needed to link TinyGo.
-EXTRA_LIB_NAMES = LLVMInterpreter
+EXTRA_LIB_NAMES = LLVMInterpreter LLVMMCA LLVMX86TargetMCA

 # All libraries to be built and linked with the tinygo binary (lib/lib*.a).
 LIB_NAMES = clang $(CLANG_LIB_NAMES) $(LLD_LIB_NAMES) $(EXTRA_LIB_NAMES)
@@ -108,9 +133,9 @@ NINJA_BUILD_TARGETS = clang llvm-config llvm-ar llvm-nm $(addprefix lib/lib,$(ad

 # For static linking.
 ifneq ("$(wildcard $(LLVM_BUILDDIR)/bin/llvm-config*)","")
-    CGO_CPPFLAGS+=$(shell $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
+    CGO_CPPFLAGS+=$(shell $(LLVM_CONFIG_PREFIX) $(LLVM_BUILDDIR)/bin/llvm-config --cppflags) -I$(abspath $(LLVM_BUILDDIR))/tools/clang/include -I$(abspath $(CLANG_SRC))/include -I$(abspath $(LLD_SRC))/include
    CGO_CXXFLAGS=-std=c++14
-    CGO_LDFLAGS+=-L$(abspath $(LLVM_BUILDDIR)/lib) -lclang $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
+    CGO_LDFLAGS+=-L$(abspath $(LLVM_BUILDDIR)/lib) -lclang $(CLANG_LIBS) $(LLD_LIBS) $(shell $(LLVM_CONFIG_PREFIX) $(LLVM_BUILDDIR)/bin/llvm-config --ldflags --libs --system-libs $(LLVM_COMPONENTS)) -lstdc++ $(CGO_LDFLAGS_EXTRA)
 endif

 clean:
@@ -173,7 +198,7 @@ gen-device-rp: build/gen-device-svd

 # Get LLVM sources.
 $(LLVM_PROJECTDIR)/llvm:
-	git clone -b xtensa_release_13.0.0 --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
+	git clone -b xtensa_release_14.0.0-patched --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
 llvm-source: $(LLVM_PROJECTDIR)/llvm

 # Configure LLVM.
@@ -200,25 +225,24 @@ endif
 wasi-libc: lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a
 lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
 	@if [ ! -e lib/wasi-libc/Makefile ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
-	cd lib/wasi-libc && make -j4 WASM_CFLAGS="-O2 -g -DNDEBUG" WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)
+	cd lib/wasi-libc && make -j4 WASM_CFLAGS="-O2 -g -DNDEBUG" MALLOC_IMPL=none WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)


 # Build the Go compiler.
 tinygo:
 	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  make llvm-source"; echo "  make $(LLVM_BUILDDIR)"; exit 1; fi
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X main.gitSha1=`git rev-parse --short HEAD`" .
-
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GOENVFLAGS) $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X github.com/tinygo-org/tinygo/goenv.GitSha1=`git rev-parse --short HEAD`" .
 test: wasi-libc
 	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test $(GOTESTFLAGS) -timeout=20m -buildmode exe -tags byollvm ./builder ./cgo ./compileopts ./compiler ./interp ./transform .

-# Tests that take over a minute in wasi
+# Standard library packages that pass tests on darwin, linux, wasi, and windows, but take over a minute in wasi
 TEST_PACKAGES_SLOW = \
 	compress/bzip2 \
-	compress/flate \
 	crypto/dsa \
 	index/suffixarray \

-TEST_PACKAGES_BASE = \
+# Standard library packages that pass tests quickly on darwin, linux, wasi, and windows
+TEST_PACKAGES_FAST = \
 	compress/zlib \
 	container/heap \
 	container/list \
@@ -247,6 +271,7 @@ TEST_PACKAGES_BASE = \
 	internal/profile \
 	math \
 	math/cmplx \
+	net \
 	net/http/internal/ascii \
 	net/mail \
 	os \
@@ -260,40 +285,70 @@ TEST_PACKAGES_BASE = \
 	unicode/utf16 \
 	unicode/utf8 \

-# Standard library packages that pass tests natively
-TEST_PACKAGES := \
-	$(TEST_PACKAGES_BASE)
+# archive/zip requires os.ReadAt, which is not yet supported on windows
+# debug/plan9obj requires os.ReadAt, which is not yet supported on windows
+# io/fs requires os.ReadDir, which is not yet supported on windows or wasi
+# testing/fstest requires os.ReadDir, which is not yet supported on windows or wasi
+# compress/flate fails windows go 1.18, https://github.com/tinygo-org/tinygo/issues/2762
+# compress/lzw fails windows go 1.18 wasi, https://github.com/tinygo-org/tinygo/issues/2762

-# archive/zip requires ReadAt, which is not yet supported on windows
-ifneq ($(OS),Windows_NT)
-TEST_PACKAGES := \
-	$(TEST_PACKAGES) \
-	archive/zip
+# Additional standard library packages that pass tests on individual platforms
+TEST_PACKAGES_LINUX := \
+	archive/zip \
+	compress/flate \
+	compress/lzw \
+	debug/dwarf \
+	debug/plan9obj \
+	io/fs \
+	testing/fstest
+
+TEST_PACKAGES_DARWIN := $(TEST_PACKAGES_LINUX)
+
+TEST_PACKAGES_WINDOWS := \
+	compress/lzw
+
+# Report platforms on which each standard library package is known to pass tests
+jointmp := $(shell echo /tmp/join.$$$$)
+report-stdlib-tests-pass:
+	@for t in $(TEST_PACKAGES_DARWIN); do echo "$$t darwin"; done | sort > $(jointmp).darwin
+	@for t in $(TEST_PACKAGES_LINUX); do echo "$$t linux"; done | sort > $(jointmp).linux
+	@for t in $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW); do echo "$$t darwin linux wasi windows"; done | sort > $(jointmp).portable
+	@join -a1 -a2 $(jointmp).darwin $(jointmp).linux | \
+	join -a1 -a2 - $(jointmp).portable
+	@rm $(jointmp).*
+
+# Standard library packages that pass tests quickly on the current platform
+ifeq ($(shell uname),Darwin)
+TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_DARWIN)
+endif
+ifeq ($(shell uname),Linux)
+TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_LINUX)
+endif
+ifeq ($(OS),Windows_NT)
+TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
 endif
-
-# Standard library packages that pass tests on wasi
-TEST_PACKAGES_WASI = \
-	$(TEST_PACKAGES_BASE)

 # Test known-working standard library packages.
 # TODO: parallelize, and only show failing tests (no implied -v flag).
 .PHONY: tinygo-test
 tinygo-test:
-	$(TINYGO) test $(TEST_PACKAGES) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
 tinygo-test-fast:
-	$(TINYGO) test $(TEST_PACKAGES)
+	$(TINYGO) test $(TEST_PACKAGES_HOST)
 tinygo-bench:
-	$(TINYGO) test -bench . $(TEST_PACKAGES) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test -bench . $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
 tinygo-bench-fast:
-	$(TINYGO) test -bench . $(TEST_PACKAGES)
+	$(TINYGO) test -bench . $(TEST_PACKAGES_HOST)
+
+# Same thing, except for wasi rather than the current platform.
 tinygo-test-wasi:
-	$(TINYGO) test -target wasi $(TEST_PACKAGES_WASI) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW)
 tinygo-test-wasi-fast:
-	$(TINYGO) test -target wasi $(TEST_PACKAGES_WASI)
+	$(TINYGO) test -target wasi $(TEST_PACKAGES_FAST)
 tinygo-bench-wasi:
-	$(TINYGO) test -target wasi -bench . $(TEST_PACKAGES_WASI) $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test -target wasi -bench . $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW)
 tinygo-bench-wasi-fast:
-	$(TINYGO) test -target wasi -bench . $(TEST_PACKAGES_WASI)
+	$(TINYGO) test -target wasi -bench . $(TEST_PACKAGES_FAST)

 # Test external packages in a large corpus.
 test-corpus:
@@ -303,10 +358,16 @@ test-corpus-fast:
 test-corpus-wasi: wasi-libc
 	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test $(GOTESTFLAGS) -timeout=1h -buildmode exe -tags byollvm -run TestCorpus . -corpus=testdata/corpus.yaml -target=wasi

+tinygo-baremetal:
+	# Regression tests that run on a baremetal target and don't fit in either main_test.go or smoketest.
+	# regression test for #2666: e.g. encoding/hex must pass on baremetal
+	$(TINYGO) test -target cortex-m-qemu encoding/hex

 .PHONY: smoketest
 smoketest:
 	$(TINYGO) version
+	# compile-only platform-independent examples
+	cd tests/text/template/smoke && $(TINYGO) test -c && rm -f smoke.test
 	# regression test for #2563
 	cd tests/os/smoke && $(TINYGO) test -c -target=pybadge && rm smoke.test
 	# test all examples (except pwm)
@@ -354,6 +415,8 @@ ifneq ($(WASM), 0)
 	@$(MD5SUM) test.wasm
 	$(TINYGO) build -size short -o test.wasm -tags=circuitplay_express  examples/blinky1
 	@$(MD5SUM) test.wasm
+	$(TINYGO) build -size short -o test.wasm -tags=circuitplay_bluefruit examples/blinky1
+	@$(MD5SUM) test.wasm
 endif
 	# test all targets/boards
 	$(TINYGO) build -size short -o test.hex -target=pca10040-s132v6     examples/blinky1
@@ -442,6 +505,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=qtpy                examples/serial
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=teensy41            examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=teensy40            examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=teensy36            examples/blinky1
@@ -468,6 +533,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-rp2040 		examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=macropad-rp2040 	examples/blinky1
+	@$(MD5SUM) test.hex
 	# test pwm
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
 	@$(MD5SUM) test.hex
@@ -566,6 +633,7 @@ endif
 	@$(MD5SUM) test.hex
 	GOOS=linux GOARCH=arm $(TINYGO) build -size short -o test.elf       ./testdata/cgo
 	GOOS=windows GOARCH=amd64 $(TINYGO) build -size short -o test.exe   ./testdata/cgo
+	GOOS=darwin GOARCH=amd64 $(TINYGO) build              -o test       ./testdata/cgo
 ifneq ($(OS),Windows_NT)
 	# TODO: this does not yet work on Windows. Somehow, unused functions are
 	# not garbage collected.
@@ -580,7 +648,7 @@ build/release: tinygo gen-device wasi-libc $(if $(filter 1,$(USE_SYSTEM_BINARYEN
 	@mkdir -p build/release/tinygo/bin
 	@mkdir -p build/release/tinygo/lib/clang/include
 	@mkdir -p build/release/tinygo/lib/CMSIS/CMSIS
-	@mkdir -p build/release/tinygo/lib/compiler-rt/lib
+	@mkdir -p build/release/tinygo/lib/macos-minimal-sdk
 	@mkdir -p build/release/tinygo/lib/mingw-w64/mingw-w64-crt/lib-common
 	@mkdir -p build/release/tinygo/lib/mingw-w64/mingw-w64-headers/defaults
 	@mkdir -p build/release/tinygo/lib/musl/arch
@@ -601,9 +669,7 @@ endif
 	@cp -p $(abspath $(CLANG_SRC))/lib/Headers/*.h build/release/tinygo/lib/clang/include
 	@cp -rp lib/CMSIS/CMSIS/Include      build/release/tinygo/lib/CMSIS/CMSIS
 	@cp -rp lib/CMSIS/README.md          build/release/tinygo/lib/CMSIS
-	@cp -rp lib/compiler-rt/lib/builtins build/release/tinygo/lib/compiler-rt/lib
-	@cp -rp lib/compiler-rt/LICENSE.TXT  build/release/tinygo/lib/compiler-rt
-	@cp -rp lib/compiler-rt/README.txt   build/release/tinygo/lib/compiler-rt
+	@cp -rp lib/macos-minimal-sdk/*      build/release/tinygo/lib/macos-minimal-sdk
 	@cp -rp lib/musl/arch/aarch64        build/release/tinygo/lib/musl/arch
 	@cp -rp lib/musl/arch/arm            build/release/tinygo/lib/musl/arch
 	@cp -rp lib/musl/arch/generic        build/release/tinygo/lib/musl/arch
@@ -639,6 +705,8 @@ endif
 	@cp -rp lib/picolibc/newlib/libm/common      build/release/tinygo/lib/picolibc/newlib/libm
 	@cp -rp lib/picolibc-stdio.c         build/release/tinygo/lib
 	@cp -rp lib/wasi-libc/sysroot        build/release/tinygo/lib/wasi-libc/sysroot
+	@cp -rp llvm-project/compiler-rt/lib/builtins build/release/tinygo/lib/compiler-rt-builtins
+	@cp -rp llvm-project/compiler-rt/LICENSE.TXT  build/release/tinygo/lib/compiler-rt-builtins
 	@cp -rp src                          build/release/tinygo/src
 	@cp -rp targets                      build/release/tinygo/targets
 	./build/tinygo build-library -target=cortex-m0     -o build/release/tinygo/pkg/thumbv6m-unknown-unknown-eabi-cortex-m0/compiler-rt     compiler-rt
@@ -648,12 +716,18 @@ endif
 	./build/tinygo build-library -target=cortex-m0plus -o build/release/tinygo/pkg/thumbv6m-unknown-unknown-eabi-cortex-m0plus/picolibc picolibc
 	./build/tinygo build-library -target=cortex-m4     -o build/release/tinygo/pkg/thumbv7em-unknown-unknown-eabi-cortex-m4/picolibc    picolibc

-release: build/release
+release:
 	tar -czf build/release.tar.gz -C build/release tinygo

-deb: build/release
+DEB_ARCH ?= native
+deb:
 	@mkdir -p build/release-deb/usr/local/bin
 	@mkdir -p build/release-deb/usr/local/lib
 	cp -ar build/release/tinygo build/release-deb/usr/local/lib/tinygo
 	ln -sf ../lib/tinygo/bin/tinygo build/release-deb/usr/local/bin/tinygo
-	fpm -f -s dir -t deb -n tinygo -v $(shell grep "const Version = " goenv/version.go | awk '{print $$NF}') -m '@tinygo-org' --description='TinyGo is a Go compiler for small places.' --license='BSD 3-Clause' --url=https://tinygo.org/ --deb-changelog CHANGELOG.md -p build/release.deb -C ./build/release-deb
+	fpm -f -s dir -t deb -n tinygo -a $(DEB_ARCH) -v $(shell grep "const Version = " goenv/version.go | awk '{print $$NF}') -m '@tinygo-org' --description='TinyGo is a Go compiler for small places.' --license='BSD 3-Clause' --url=https://tinygo.org/ --deb-changelog CHANGELOG.md -p build/release.deb -C ./build/release-deb
+
+ifneq ($(RELEASEONLY), 1)
+release: build/release
+deb: build/release
+endif
@@ -43,7 +43,7 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for

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

-The following 80 microcontroller boards are currently supported:
+The following 85 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)
@@ -59,6 +59,7 @@ The following 80 microcontroller boards are currently supported:
 * [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 MacroPad RP2040](https://www.adafruit.com/product/5100)
 * [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)
@@ -84,6 +85,7 @@ The following 80 microcontroller boards are currently supported:
 * [Dragino LoRaWAN GPS Tracker LGT-92](http://www.dragino.com/products/lora-lorawan-end-node/item/142-lgt-92.html)
 * [ESP32 - Core board](https://www.espressif.com/en/products/socs/esp32)
 * [ESP32 - mini32](https://www.espressif.com/en/products/socs/esp32)
+* [ESP32-C3-12f](https://www.espressif.com/en/products/socs/esp32-c3)
 * [ESP8266 - d1mini](https://www.espressif.com/en/products/socs/esp8266)
 * [ESP8266 - NodeMCU](https://www.espressif.com/en/products/socs/esp8266)
 * [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
@@ -106,14 +108,17 @@ The following 80 microcontroller boards are currently supported:
 * [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)
+* [PJRC Teensy 4.1](https://www.pjrc.com/store/teensy41.html)
 * [ProductivityOpen P1AM-100](https://facts-engineering.github.io/modules/P1AM-100/P1AM-100.html)
 * [Raspberry Pi Pico](https://www.raspberrypi.org/products/raspberry-pi-pico/)
 * [Raytac MDBT50Q-RX Dongle (with TinyUF2 bootloader)](https://www.adafruit.com/product/5199)
 * [Seeed Seeeduino XIAO](https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html)
+* [Seeed XIAO BLE](https://www.seeedstudio.com/Seeed-XIAO-BLE-nRF52840-p-5201.html)
 * [Seeed LoRa-E5 Development Kit](https://www.seeedstudio.com/LoRa-E5-Dev-Kit-p-4868.html)
 * [Seeed Sipeed MAix BiT](https://www.seeedstudio.com/Sipeed-MAix-BiT-for-RISC-V-AI-IoT-p-2872.html)
 * [Seeed Wio Terminal](https://www.seeedstudio.com/Wio-Terminal-p-4509.html)
 * [SiFIve HiFive1 Rev B](https://www.sifive.com/boards/hifive1)
+* [Sparkfun Thing Plus RP2040](https://www.sparkfun.com/products/17745)
 * [ST Micro "Nucleo" F103RB](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
 * [ST Micro "Nucleo" F722ZE](https://www.st.com/en/evaluation-tools/nucleo-f722ze.html)
 * [ST Micro "Nucleo" L031K6](https://www.st.com/ja/evaluation-tools/nucleo-l031k6.html)
@@ -37,8 +37,14 @@ import (
 // BuildResult is the output of a build. This includes the binary itself and
 // some other metadata that is obtained while building the binary.
 type BuildResult struct {
+	// The executable directly from the linker, usually including debug
+	// information. Used for GDB for example.
+	Executable string
+
 	// A path to the output binary. It will be removed after Build returns, so
 	// if it should be kept it must be copied or moved away.
+	// It is often the same as Executable, but differs if the output format is
+	// .hex for example (instead of the usual ELF).
 	Binary string

 	// The directory of the main package. This is useful for testing as the test
@@ -99,7 +105,20 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 	if err != nil {
 		return err
 	}
-	defer os.RemoveAll(dir)
+	if config.Options.Work {
+		fmt.Printf("WORK=%s\n", dir)
+	} else {
+		defer os.RemoveAll(dir)
+	}
+
+	// Look up the build cache directory, which is used to speed up incremental
+	// builds.
+	cacheDir := goenv.Get("GOCACHE")
+	if cacheDir == "off" {
+		// Use temporary build directory instead, effectively disabling the
+		// build cache.
+		cacheDir = dir
+	}

 	// Check for a libc dependency.
 	// As a side effect, this also creates the headers for the given libc, if
@@ -107,6 +126,9 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 	root := goenv.Get("TINYGOROOT")
 	var libcDependencies []*compileJob
 	switch config.Target.Libc {
+	case "darwin-libSystem":
+		job := makeDarwinLibSystemJob(config, dir)
+		libcDependencies = append(libcDependencies, job)
 	case "musl":
 		job, unlock, err := Musl.load(config, dir)
 		if err != nil {
@@ -188,6 +210,21 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 	var packageJobs []*compileJob
 	packageBitcodePaths := make(map[string]string)
 	packageActionIDs := make(map[string]string)
+
+	if config.Options.GlobalValues["runtime"]["buildVersion"] == "" {
+		version := goenv.Version
+		if strings.HasSuffix(goenv.Version, "-dev") && goenv.GitSha1 != "" {
+			version += "-" + goenv.GitSha1
+		}
+		if config.Options.GlobalValues == nil {
+			config.Options.GlobalValues = make(map[string]map[string]string)
+		}
+		if config.Options.GlobalValues["runtime"] == nil {
+			config.Options.GlobalValues["runtime"] = make(map[string]string)
+		}
+		config.Options.GlobalValues["runtime"]["buildVersion"] = version
+	}
+
 	for _, pkg := range lprogram.Sorted() {
 		pkg := pkg // necessary to avoid a race condition

@@ -231,12 +268,6 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil

 		// 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

@@ -409,7 +440,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 			// 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("")
+			mod = ctx.NewModule("main")
 			for _, pkg := range lprogram.Sorted() {
 				pkgMod, err := ctx.ParseBitcodeFile(packageBitcodePaths[pkg.ImportPath])
 				if err != nil {
@@ -505,8 +536,14 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 			}
 			return ioutil.WriteFile(outpath, llvmBuf.Bytes(), 0666)
 		case ".bc":
-			data := llvm.WriteBitcodeToMemoryBuffer(mod).Bytes()
-			return ioutil.WriteFile(outpath, data, 0666)
+			var buf llvm.MemoryBuffer
+			if config.UseThinLTO() {
+				buf = llvm.WriteThinLTOBitcodeToMemoryBuffer(mod)
+			} else {
+				buf = llvm.WriteBitcodeToMemoryBuffer(mod)
+			}
+			defer buf.Dispose()
+			return ioutil.WriteFile(outpath, buf.Bytes(), 0666)
 		case ".ll":
 			data := []byte(mod.String())
 			return ioutil.WriteFile(outpath, data, 0666)
@@ -526,10 +563,17 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 		dependencies: []*compileJob{programJob},
 		result:       objfile,
 		run: func(*compileJob) error {
-			llvmBuf, err := machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
-			if err != nil {
-				return err
+			var llvmBuf llvm.MemoryBuffer
+			if config.UseThinLTO() {
+				llvmBuf = llvm.WriteThinLTOBitcodeToMemoryBuffer(mod)
+			} else {
+				var err error
+				llvmBuf, err = machine.EmitToMemoryBuffer(mod, llvm.ObjectFile)
+				if err != nil {
+					return err
+				}
 			}
+			defer llvmBuf.Dispose()
 			return ioutil.WriteFile(objfile, llvmBuf.Bytes(), 0666)
 		},
 	}
@@ -562,7 +606,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 		job := &compileJob{
 			description: "compile extra file " + path,
 			run: func(job *compileJob) error {
-				result, err := compileAndCacheCFile(abspath, dir, config.CFlags(), config.Options.PrintCommands)
+				result, err := compileAndCacheCFile(abspath, dir, config.CFlags(), config.UseThinLTO(), config.Options.PrintCommands)
 				job.result = result
 				return err
 			},
@@ -580,7 +624,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 			job := &compileJob{
 				description: "compile CGo file " + abspath,
 				run: func(job *compileJob) error {
-					result, err := compileAndCacheCFile(abspath, dir, pkg.CFlags, config.Options.PrintCommands)
+					result, err := compileAndCacheCFile(abspath, dir, pkg.CFlags, config.UseThinLTO(), config.Options.PrintCommands)
 					job.result = result
 					return err
 				},
@@ -649,6 +693,24 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 			if config.Options.PrintCommands != nil {
 				config.Options.PrintCommands(config.Target.Linker, ldflags...)
 			}
+			if config.UseThinLTO() {
+				ldflags = append(ldflags,
+					"--thinlto-cache-dir="+filepath.Join(cacheDir, "thinlto"),
+					"-plugin-opt=mcpu="+config.CPU(),
+					"-plugin-opt=O"+strconv.Itoa(optLevel),
+					"-plugin-opt=thinlto")
+				if config.CodeModel() != "default" {
+					ldflags = append(ldflags,
+						"-mllvm", "-code-model="+config.CodeModel())
+				}
+				if sizeLevel >= 2 {
+					// Workaround with roughly the same effect as
+					// https://reviews.llvm.org/D119342.
+					// Can hopefully be removed in LLVM 15.
+					ldflags = append(ldflags,
+						"-mllvm", "--rotation-max-header-size=0")
+				}
+			}
 			err = link(config.Target.Linker, ldflags...)
 			if err != nil {
 				return &commandError{"failed to link", executable, err}
@@ -779,7 +841,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 		if err != nil {
 			return err
 		}
-	case "esp32", "esp32c3", "esp8266":
+	case "esp32", "esp32-img", "esp32c3", "esp8266":
 		// Special format for the ESP family of chips (parsed by the ROM
 		// bootloader).
 		tmppath = filepath.Join(dir, "main"+outext)
@@ -811,6 +873,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 	}

 	return action(BuildResult{
+		Executable: executable,
 		Binary:     tmppath,
 		MainDir:    lprogram.MainPkg().Dir,
 		ModuleRoot: moduleroot,
@@ -839,7 +902,7 @@ func optimizeProgram(mod llvm.Module, config *compileopts.Config) error {
 		}
 	}

-	if config.GOOS() != "darwin" {
+	if config.GOOS() != "darwin" && !config.UseThinLTO() {
 		transform.ApplyFunctionSections(mod) // -ffunction-sections
 	}

@@ -30,6 +30,7 @@ func ReadBuildID() ([]byte, error) {
 		if err != nil {
 			return nil, err
 		}
+		var gnuID, goID []byte
 		for _, section := range file.Sections {
 			if section.Type != elf.SHT_NOTE ||
 				(section.Name != ".note.gnu.build-id" && section.Name != ".note.go.buildid") {
@@ -40,7 +41,16 @@ func ReadBuildID() ([]byte, error) {
 			if uint64(n) != section.Size || err != nil {
 				return nil, fmt.Errorf("could not read build id: %w", err)
 			}
-			return buf, nil
+			if section.Name == ".note.gnu.build-id" {
+				gnuID = buf
+			} else {
+				goID = buf
+			}
+		}
+		if gnuID != nil {
+			return gnuID, nil
+		} else if goID != nil {
+			return goID, nil
 		}
 	case "darwin":
 		// Read the LC_UUID load command, which contains the equivalent of a
@@ -1,7 +1,11 @@
 package builder

 import (
+	"os"
+	"path/filepath"
 	"strings"
+
+	"github.com/tinygo-org/tinygo/goenv"
 )

 // These are the GENERIC_SOURCES according to CMakeList.txt.
@@ -72,6 +76,7 @@ var genericBuiltins = []string{
 	"floatunsisf.c",
 	"floatuntidf.c",
 	"floatuntisf.c",
+	"fp_mode.c",
 	//"int_util.c",
 	"lshrdi3.c",
 	"lshrti3.c",
@@ -161,7 +166,15 @@ var CompilerRT = Library{
 	cflags: func(target, headerPath string) []string {
 		return []string{"-Werror", "-Wall", "-std=c11", "-nostdlibinc"}
 	},
-	sourceDir: "lib/compiler-rt/lib/builtins",
+	sourceDir: func() string {
+		llvmDir := filepath.Join(goenv.Get("TINYGOROOT"), "llvm-project/compiler-rt/lib/builtins")
+		if _, err := os.Stat(llvmDir); err == nil {
+			// Release build.
+			return llvmDir
+		}
+		// Development build.
+		return filepath.Join(goenv.Get("TINYGOROOT"), "lib/compiler-rt-builtins")
+	},
 	librarySources: func(target string) []string {
 		builtins := append([]string{}, genericBuiltins...) // copy genericBuiltins
 		if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
@@ -56,7 +56,7 @@ import (
 //   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 func(string, ...string)) (string, error) {
+func compileAndCacheCFile(abspath, tmpdir string, cflags []string, thinlto bool, printCommands func(string, ...string)) (string, error) {
 	// Hash input file.
 	fileHash, err := hashFile(abspath)
 	if err != nil {
@@ -67,6 +67,11 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 	unlock := lock(filepath.Join(goenv.Get("GOCACHE"), fileHash+".c.lock"))
 	defer unlock()

+	ext := ".o"
+	if thinlto {
+		ext = ".bc"
+	}
+
 	// Create cache key for the dependencies file.
 	buf, err := json.Marshal(struct {
 		Path        string
@@ -99,7 +104,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 		}

 		// Obtain hashes of all the files listed as a dependency.
-		outpath, err := makeCFileCachePath(dependencies, depfileNameHash)
+		outpath, err := makeCFileCachePath(dependencies, depfileNameHash, ext)
 		if err == nil {
 			if _, err := os.Stat(outpath); err == nil {
 				return outpath, nil
@@ -112,7 +117,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 		return "", err
 	}

-	objTmpFile, err := ioutil.TempFile(goenv.Get("GOCACHE"), "tmp-*.o")
+	objTmpFile, err := ioutil.TempFile(goenv.Get("GOCACHE"), "tmp-*"+ext)
 	if err != nil {
 		return "", err
 	}
@@ -124,6 +129,9 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 	depTmpFile.Close()
 	flags := append([]string{}, cflags...)                                   // copy cflags
 	flags = append(flags, "-MD", "-MV", "-MTdeps", "-MF", depTmpFile.Name()) // autogenerate dependencies
+	if thinlto {
+		flags = append(flags, "-flto=thin")
+	}
 	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
@@ -181,7 +189,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 	}

 	// Move temporary object file to final location.
-	outpath, err := makeCFileCachePath(dependencySlice, depfileNameHash)
+	outpath, err := makeCFileCachePath(dependencySlice, depfileNameHash, ext)
 	if err != nil {
 		return "", err
 	}
@@ -196,7 +204,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, printCommands
 // 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) {
+func makeCFileCachePath(paths []string, depfileNameHash, ext string) (string, error) {
 	// Hash all input files.
 	fileHashes := make(map[string]string, len(paths))
 	for _, path := range paths {
@@ -221,7 +229,7 @@ func makeCFileCachePath(paths []string, depfileNameHash string) (string, error)
 	outFileNameBuf := sha512.Sum512_224(buf)
 	cacheKey := hex.EncodeToString(outFileNameBuf[:])

-	outpath := filepath.Join(goenv.Get("GOCACHE"), "obj-"+cacheKey+".o")
+	outpath := filepath.Join(goenv.Get("GOCACHE"), "obj-"+cacheKey+ext)
 	return outpath, nil
 }

@@ -38,6 +38,7 @@
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCTargetOptions.h"
+#include "llvm/MC/TargetRegistry.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/OptTable.h"
@@ -51,7 +52,6 @@
 #include "llvm/Support/Process.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/SourceMgr.h"
-#include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
@@ -120,7 +120,6 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
        llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue())
            .Case("none", llvm::DebugCompressionType::None)
            .Case("zlib", llvm::DebugCompressionType::Z)
-            .Case("zlib-gnu", llvm::DebugCompressionType::GNU)
            .Default(llvm::DebugCompressionType::None);
  }

@@ -382,7 +381,7 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
        T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI,
        Opts.RelaxAll, Opts.IncrementalLinkerCompatible,
        /*DWARFMustBeAtTheEnd*/ true));
-    Str.get()->InitSections(Opts.NoExecStack);
+    Str.get()->initSections(Opts.NoExecStack, *STI);
  }

  // When -fembed-bitcode is passed to clang_as, a 1-byte marker
@@ -442,7 +441,7 @@ bool ExecuteAssembler(AssemblerInvocation &Opts,
  return Failed;
 }

-static void LLVMErrorHandler(void *UserData, const std::string &Message,
+static void LLVMErrorHandler(void *UserData, const char *Message,
                             bool GenCrashDiag) {
  DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);

@@ -33,8 +33,8 @@ 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 < 15 || minor > 17 {
-		return nil, fmt.Errorf("requires go version 1.15 through 1.17, got go%d.%d", major, minor)
+	if major != 1 || minor < 15 || minor > 18 {
+		return nil, fmt.Errorf("requires go version 1.15 through 1.18, got go%d.%d", major, minor)
 	}

 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
@@ -0,0 +1,63 @@
+package builder
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/goenv"
+	"tinygo.org/x/go-llvm"
+)
+
+// Create a job that builds a Darwin libSystem.dylib stub library. This library
+// contains all the symbols needed so that we can link against it, but it
+// doesn't contain any real symbol implementations.
+func makeDarwinLibSystemJob(config *compileopts.Config, tmpdir string) *compileJob {
+	return &compileJob{
+		description: "compile Darwin libSystem.dylib",
+		run: func(job *compileJob) (err error) {
+			arch := strings.Split(config.Triple(), "-")[0]
+			job.result = filepath.Join(tmpdir, "libSystem.dylib")
+			objpath := filepath.Join(tmpdir, "libSystem.o")
+			inpath := filepath.Join(goenv.Get("TINYGOROOT"), "lib/macos-minimal-sdk/src", arch, "libSystem.s")
+
+			// Compile assembly file to object file.
+			flags := []string{
+				"-nostdlib",
+				"--target=" + config.Triple(),
+				"-c",
+				"-o", objpath,
+				inpath,
+			}
+			if config.Options.PrintCommands != nil {
+				config.Options.PrintCommands("clang", flags...)
+			}
+			err = runCCompiler(flags...)
+			if err != nil {
+				return err
+			}
+
+			// Link object file to dynamic library.
+			platformVersion := strings.TrimPrefix(strings.Split(config.Triple(), "-")[2], "macosx")
+			flavor := "darwin"
+			if strings.Split(llvm.Version, ".")[0] < "13" {
+				flavor = "darwinnew" // needed on LLVM 12 and below
+			}
+			flags = []string{
+				"-flavor", flavor,
+				"-demangle",
+				"-dynamic",
+				"-dylib",
+				"-arch", arch,
+				"-platform_version", "macos", platformVersion, platformVersion,
+				"-install_name", "/usr/lib/libSystem.B.dylib",
+				"-o", job.result,
+				objpath,
+			}
+			if config.Options.PrintCommands != nil {
+				config.Options.PrintCommands("ld.lld", flags...)
+			}
+			return link("ld.lld", flags...)
+		},
+	}
+}
@@ -15,6 +15,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"sort"
+	"strings"
 )

 type espImageSegment struct {
@@ -78,15 +79,31 @@ func makeESPFirmareImage(infile, outfile, format string) error {
 	// An added benefit is that we don't need to check for errors all the time.
 	outf := &bytes.Buffer{}

+	// Separate esp32 and esp32-img. The -img suffix indicates we should make an
+	// image, not just a binary to be flashed at 0x1000 for example.
+	chip := format
+	makeImage := false
+	if strings.HasSuffix(format, "-img") {
+		makeImage = true
+		chip = format[:len(format)-len("-img")]
+	}
+
+	if makeImage {
+		// The bootloader starts at 0x1000, or 4096.
+		// TinyGo doesn't use a separate bootloader and runs the entire
+		// application in the bootloader location.
+		outf.Write(make([]byte, 4096))
+	}
+
 	// Chip IDs. Source:
 	// https://github.com/espressif/esp-idf/blob/v4.3/components/bootloader_support/include/esp_app_format.h#L22
 	chip_id := map[string]uint16{
 		"esp32":   0x0000,
 		"esp32c3": 0x0005,
-	}[format]
+	}[chip]

 	// Image header.
-	switch format {
+	switch chip {
 	case "esp32", "esp32c3":
 		// Header format:
 		// https://github.com/espressif/esp-idf/blob/v4.3/components/bootloader_support/include/esp_app_format.h#L71
@@ -155,12 +172,22 @@ func makeESPFirmareImage(infile, outfile, format string) error {
 	outf.Write(make([]byte, 15-outf.Len()%16))
 	outf.WriteByte(checksum)

-	if format != "esp8266" {
+	if chip != "esp8266" {
 		// SHA256 hash (to protect against image corruption, not for security).
 		hash := sha256.Sum256(outf.Bytes())
 		outf.Write(hash[:])
 	}

+	// QEMU (or more precisely, qemu-system-xtensa from Espressif) expects the
+	// image to be a certain size.
+	if makeImage {
+		// Use a default image size of 4MB.
+		grow := 4096*1024 - outf.Len()
+		if grow > 0 {
+			outf.Write(make([]byte, grow))
+		}
+	}
+
 	// Write the image to the output file.
 	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
 }
@@ -24,8 +24,8 @@ type Library struct {
 	// cflags returns the C flags specific to this library
 	cflags func(target, headerPath string) []string

-	// The source directory, relative to TINYGOROOT.
-	sourceDir string
+	// The source directory.
+	sourceDir func() string

 	// The source files, relative to sourceDir.
 	librarySources func(target string) []string
@@ -103,6 +103,10 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 			if err != nil {
 				return nil, nil, err
 			}
+			err = os.Chmod(temporaryHeaderPath, 0o755) // TempDir uses 0o700 by default
+			if err != nil {
+				return nil, nil, err
+			}
 			err = os.Rename(temporaryHeaderPath, headerPath)
 			if err != nil {
 				switch {
@@ -149,7 +153,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 		}
 	}
 	if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
-		args = append(args, "-fshort-enums", "-fomit-frame-pointer", "-mfloat-abi=soft", "-fno-unwind-tables")
+		args = append(args, "-fshort-enums", "-fomit-frame-pointer", "-mfloat-abi=soft", "-fno-unwind-tables", "-fno-asynchronous-unwind-tables")
 	}
 	if strings.HasPrefix(target, "riscv32-") {
 		args = append(args, "-march=rv32imac", "-mabi=ilp32", "-fforce-enable-int128")
@@ -157,6 +161,12 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 	if strings.HasPrefix(target, "riscv64-") {
 		args = append(args, "-march=rv64gc", "-mabi=lp64")
 	}
+	if strings.HasPrefix(target, "xtensa") {
+		// Hack to work around an issue in the Xtensa port:
+		// https://github.com/espressif/llvm-project/issues/52
+		// Hopefully this will be fixed soon (LLVM 14).
+		args = append(args, "-D__ELF__")
+	}

 	var once sync.Once

@@ -182,11 +192,17 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 			if err != nil {
 				return err
 			}
+			err = os.Chmod(f.Name(), 0o644) // TempFile uses 0o600 by default
+			if err != nil {
+				return err
+			}
 			// Store this archive in the cache.
 			return os.Rename(f.Name(), archiveFilePath)
 		},
 	}

+	sourceDir := l.sourceDir()
+
 	// Create jobs to compile all sources. These jobs are depended upon by the
 	// archive job above, so must be run first.
 	for _, path := range l.librarySources(target) {
@@ -195,7 +211,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 		for strings.HasPrefix(cleanpath, "../") {
 			cleanpath = cleanpath[3:]
 		}
-		srcpath := filepath.Join(goenv.Get("TINYGOROOT"), l.sourceDir, path)
+		srcpath := filepath.Join(sourceDir, path)
 		objpath := filepath.Join(dir, cleanpath+".o")
 		os.MkdirAll(filepath.Dir(objpath), 0o777)
 		objs = append(objs, objpath)
@@ -219,7 +235,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 	// (It could be done in parallel with creating the ar file, but it probably
 	// won't make much of a difference in speed).
 	if l.crt1Source != "" {
-		srcpath := filepath.Join(goenv.Get("TINYGOROOT"), l.sourceDir, l.crt1Source)
+		srcpath := filepath.Join(sourceDir, l.crt1Source)
 		job.dependencies = append(job.dependencies, &compileJob{
 			description: "compile " + srcpath,
 			run: func(*compileJob) error {
@@ -8,17 +8,22 @@ extern "C" {

 bool tinygo_link_elf(int argc, char **argv) {
 	std::vector<const char*> args(argv, argv + argc);
-	return lld::elf::link(args, false, llvm::outs(), llvm::errs());
+	return lld::elf::link(args, llvm::outs(), llvm::errs(), false, false);
+}
+
+bool tinygo_link_macho(int argc, char **argv) {
+	std::vector<const char*> args(argv, argv + argc);
+	return lld::macho::link(args, llvm::outs(), llvm::errs(), false, false);
 }

 bool tinygo_link_mingw(int argc, char **argv) {
 	std::vector<const char*> args(argv, argv + argc);
-	return lld::mingw::link(args, false, llvm::outs(), llvm::errs());
+	return lld::mingw::link(args, llvm::outs(), llvm::errs(), false, false);
 }

 bool tinygo_link_wasm(int argc, char **argv) {
 	std::vector<const char*> args(argv, argv + argc);
-	return lld::wasm::link(args, false, llvm::outs(), llvm::errs());
+	return lld::wasm::link(args, llvm::outs(), llvm::errs(), false, false);
 }

 } // external "C"
@@ -26,6 +26,7 @@ var MinGW = Library{
 		_, err = io.Copy(outf, inf)
 		return err
 	},
+	sourceDir: func() string { return "" }, // unused
 	cflags: func(target, headerPath string) []string {
 		// No flags necessary because there are no files to compile.
 		return nil
@@ -104,7 +104,7 @@ var Musl = Library{
 			"-fno-stack-protector",
 		}
 	},
-	sourceDir: "lib/musl/src",
+	sourceDir: func() string { return filepath.Join(goenv.Get("TINYGOROOT"), "lib/musl/src") },
 	librarySources: func(target string) []string {
 		arch := compileopts.MuslArchitecture(target)
 		globs := []string{
@@ -33,7 +33,7 @@ var Picolibc = Library{
 			"-I" + headerPath,
 		}
 	},
-	sourceDir: "lib/picolibc/newlib/libc",
+	sourceDir: func() string { return filepath.Join(goenv.Get("TINYGOROOT"), "lib/picolibc/newlib/libc") },
 	librarySources: func(target string) []string {
 		return picolibcSources
 	},
@@ -1,3 +1,4 @@
+//go:build byollvm
 // +build byollvm

 package builder
@@ -13,6 +14,7 @@ import (
 #include <stdlib.h>
 bool tinygo_clang_driver(int argc, char **argv);
 bool tinygo_link_elf(int argc, char **argv);
+bool tinygo_link_macho(int argc, char **argv);
 bool tinygo_link_mingw(int argc, char **argv);
 bool tinygo_link_wasm(int argc, char **argv);
 */
@@ -26,8 +28,13 @@ const hasBuiltinTools = true
 // linking statically with LLVM (with the byollvm build tag).
 func RunTool(tool string, args ...string) error {
 	linker := "elf"
-	if tool == "ld.lld" && len(args) >= 2 && args[0] == "-m" && args[1] == "i386pep" {
-		linker = "mingw"
+	if tool == "ld.lld" && len(args) >= 2 {
+		if args[0] == "-m" && args[1] == "i386pep" {
+			linker = "mingw"
+		} else if args[0] == "-flavor" {
+			linker = args[1]
+			args = args[2:]
+		}
 	}
 	args = append([]string{"tinygo:" + tool}, args...)

@@ -47,6 +54,8 @@ func RunTool(tool string, args ...string) error {
 		ok = C.tinygo_clang_driver(C.int(len(args)), (**C.char)(buf))
 	case "ld.lld":
 		switch linker {
+		case "darwin", "darwinnew": // darwinnew is only needed for LLVM 12 and below
+			ok = C.tinygo_link_macho(C.int(len(args)), (**C.char)(buf))
 		case "elf":
 			ok = C.tinygo_link_elf(C.int(len(args)), (**C.char)(buf))
 		case "mingw":
@@ -1,3 +1,4 @@
+//go:build !byollvm
 // +build !byollvm

 package builder
@@ -197,7 +197,7 @@ func GoBytes(ptr unsafe.Pointer, length C.int) []byte {
 // functions), 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, []string, map[string][]byte, []error) {
+func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string, clangHeaders string) (*ast.File, []string, []string, []string, map[string][]byte, []error) {
 	p := &cgoPackage{
 		currentDir:      dir,
 		fset:            fset,
@@ -333,6 +333,9 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// have better alternatives anyway.
 	cflagsForCGo := append([]string{"-D_FORTIFY_SOURCE=0"}, cflags...)
 	cflagsForCGo = append(cflagsForCGo, p.cflags...)
+	if clangHeaders != "" {
+		cflagsForCGo = append(cflagsForCGo, "-isystem", clangHeaders)
+	}

 	// Process CGo imports for each file.
 	for i, f := range files {
@@ -63,7 +63,7 @@ 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
@@ -16,7 +16,7 @@ import (
 )

 /*
-#include <clang-c/Index.h> // if this fails, install libclang-11-dev
+#include <clang-c/Index.h> // If this fails, libclang headers aren't available. Please take a look here: https://tinygo.org/docs/guides/build/
 #include <stdlib.h>
 #include <stdint.h>

@@ -5,12 +5,12 @@ package cgo

 /*
 #cgo linux        CFLAGS:  -I/usr/lib/llvm-11/include
-#cgo darwin amd64 CFLAGS:  -I/usr/local/opt/llvm@11/include
-#cgo darwin arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@11/include
+#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@11/include
+#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@11/include
 #cgo freebsd      CFLAGS:  -I/usr/local/llvm11/include
 #cgo linux        LDFLAGS: -L/usr/lib/llvm-11/lib -lclang
-#cgo darwin amd64 LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
-#cgo darwin arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@11/lib -lclang -lffi
+#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@11/lib -lclang -lffi
+#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@11/lib -lclang -lffi
 #cgo freebsd      LDFLAGS: -L/usr/local/llvm11/lib -lclang
 */
 import "C"
@@ -5,12 +5,12 @@ package cgo

 /*
 #cgo linux        CFLAGS:  -I/usr/lib/llvm-12/include
-#cgo darwin amd64 CFLAGS:  -I/usr/local/opt/llvm@12/include
-#cgo darwin arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@12/include
+#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@12/include
+#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@12/include
 #cgo freebsd      CFLAGS:  -I/usr/local/llvm12/include
 #cgo linux        LDFLAGS: -L/usr/lib/llvm-12/lib -lclang
-#cgo darwin amd64 LDFLAGS: -L/usr/local/opt/llvm@12/lib -lclang -lffi
-#cgo darwin arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@12/lib -lclang -lffi
+#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@12/lib -lclang -lffi
+#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@12/lib -lclang -lffi
 #cgo freebsd      LDFLAGS: -L/usr/local/llvm12/lib -lclang
 */
 import "C"
@@ -1,16 +1,16 @@
-//go:build !byollvm && !llvm11 && !llvm12
-// +build !byollvm,!llvm11,!llvm12
+//go:build !byollvm && !llvm11 && !llvm12 && !llvm14
+// +build !byollvm,!llvm11,!llvm12,!llvm14

 package cgo

 /*
 #cgo linux        CFLAGS:  -I/usr/lib/llvm-13/include
-#cgo darwin amd64 CFLAGS:  -I/usr/local/opt/llvm@13/include
-#cgo darwin arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@13/include
+#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@13/include
+#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@13/include
 #cgo freebsd      CFLAGS:  -I/usr/local/llvm13/include
 #cgo linux        LDFLAGS: -L/usr/lib/llvm-13/lib -lclang
-#cgo darwin amd64 LDFLAGS: -L/usr/local/opt/llvm@13/lib -lclang -lffi
-#cgo darwin arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@13/lib -lclang -lffi
+#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@13/lib -lclang -lffi
+#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@13/lib -lclang -lffi
 #cgo freebsd      LDFLAGS: -L/usr/local/llvm13/lib -lclang
 */
 import "C"
@@ -0,0 +1,16 @@
+//go:build !byollvm && llvm14
+// +build !byollvm,llvm14
+
+package cgo
+
+/*
+#cgo linux        CFLAGS:  -I/usr/lib/llvm-14/include
+#cgo darwin,amd64 CFLAGS:  -I/usr/local/opt/llvm@14/include
+#cgo darwin,arm64 CFLAGS:  -I/opt/homebrew/opt/llvm@14/include
+#cgo freebsd      CFLAGS:  -I/usr/local/llvm14/include
+#cgo linux        LDFLAGS: -L/usr/lib/llvm-14/lib -lclang
+#cgo darwin,amd64 LDFLAGS: -L/usr/local/opt/llvm@14/lib -lclang -lffi
+#cgo darwin,arm64 LDFLAGS: -L/opt/homebrew/opt/llvm@14/lib -lclang -lffi
+#cgo freebsd      LDFLAGS: -L/usr/local/llvm14/lib -lclang
+*/
+import "C"
@@ -3,7 +3,7 @@
 // are slightly different from the ones defined in libclang.go, but they
 // should be ABI compatible.

-#include <clang-c/Index.h> // if this fails, install libclang-11-dev
+#include <clang-c/Index.h> // If this fails, libclang headers aren't available. Please take a look here: https://tinygo.org/docs/guides/build/

 CXCursor tinygo_clang_getTranslationUnitCursor(CXTranslationUnit tu) {
 	return clang_getTranslationUnitCursor(tu);
@@ -10,6 +10,7 @@ import (
 	"regexp"
 	"strings"

+	"github.com/google/shlex"
 	"github.com/tinygo-org/tinygo/goenv"
 )

@@ -176,6 +177,34 @@ func (c *Config) AutomaticStackSize() bool {
 	return false
 }

+// UseThinLTO returns whether ThinLTO should be used for the given target. Some
+// targets (such as wasm) are not yet supported.
+// We should try and remove as many exceptions as possible in the future, so
+// that this optimization can be applied in more places.
+func (c *Config) UseThinLTO() bool {
+	parts := strings.Split(c.Triple(), "-")
+	if parts[0] == "wasm32" {
+		// wasm-ld doesn't seem to support ThinLTO yet.
+		return false
+	}
+	if parts[0] == "avr" || parts[0] == "xtensa" {
+		// These use external (GNU) linkers which might perhaps support ThinLTO
+		// through a plugin, but it's too much hassle to set up.
+		return false
+	}
+	if len(parts) >= 2 && strings.HasPrefix(parts[2], "macos") {
+		// We use an external linker here at the moment.
+		return false
+	}
+	if len(parts) >= 2 && parts[2] == "windows" {
+		// Linker error (undefined runtime.trackedGlobalsBitmap) when linking
+		// for Windows. Disable it for now until that's figured out and fixed.
+		return false
+	}
+	// Other architectures support ThinLTO.
+	return true
+}
+
 // RP2040BootPatch returns whether the RP2040 boot patch should be applied that
 // calculates and patches in the checksum for the 2nd stage bootloader.
 func (c *Config) RP2040BootPatch() bool {
@@ -217,6 +246,29 @@ func (c *Config) LibcPath(name string) (path string, precompiled bool) {
 	return filepath.Join(goenv.Get("GOCACHE"), name+"-"+archname), false
 }

+// DefaultBinaryExtension returns the default extension for binaries, such as
+// .exe, .wasm, or no extension (depending on the target).
+func (c *Config) DefaultBinaryExtension() string {
+	parts := strings.Split(c.Triple(), "-")
+	if parts[0] == "wasm32" {
+		// WebAssembly files always have the .wasm file extension.
+		return ".wasm"
+	}
+	if len(parts) >= 3 && parts[2] == "windows" {
+		// Windows uses .exe.
+		return ".exe"
+	}
+	if len(parts) >= 3 && parts[2] == "unknown" {
+		// There appears to be a convention to use the .elf file extension for
+		// ELF files intended for microcontrollers. I'm not aware of the origin
+		// of this, it's just something that is used by many projects.
+		// I think it's a good tradition, so let's keep it.
+		return ".elf"
+	}
+	// Linux, MacOS, etc, don't use a file extension. Use it as a fallback.
+	return ""
+}
+
 // CFlags returns the flags to pass to the C compiler. This is necessary for CGo
 // preprocessing.
 func (c *Config) CFlags() []string {
@@ -225,12 +277,18 @@ func (c *Config) CFlags() []string {
 		cflags = append(cflags, strings.ReplaceAll(flag, "{root}", goenv.Get("TINYGOROOT")))
 	}
 	switch c.Target.Libc {
+	case "darwin-libSystem":
+		root := goenv.Get("TINYGOROOT")
+		cflags = append(cflags,
+			"--sysroot="+filepath.Join(root, "lib/macos-minimal-sdk/src"),
+		)
 	case "picolibc":
 		root := goenv.Get("TINYGOROOT")
 		picolibcDir := filepath.Join(root, "lib", "picolibc", "newlib", "libc")
 		path, _ := c.LibcPath("picolibc")
 		cflags = append(cflags,
 			"--sysroot="+path,
+			"-isystem", filepath.Join(path, "include"), // necessary for Xtensa
 			"-isystem", filepath.Join(picolibcDir, "include"),
 			"-isystem", filepath.Join(picolibcDir, "tinystdio"),
 		)
@@ -337,6 +395,13 @@ func (c *Config) BinaryFormat(ext string) string {
 			return c.Target.BinaryFormat
 		}
 		return "bin"
+	case ".img":
+		// Image file. Only defined for the ESP32 at the moment, where it is a
+		// full (runnable) image that can be used in the Espressif QEMU fork.
+		if c.Target.BinaryFormat != "" {
+			return c.Target.BinaryFormat + "-img"
+		}
+		return "bin"
 	case ".hex":
 		// Similar to bin, but includes the start address and is thus usually a
 		// better format.
@@ -437,13 +502,43 @@ func (c *Config) WasmAbi() string {
 	return c.Target.WasmAbi
 }

-// Emulator returns the emulator target config
-func (c *Config) Emulator() []string {
-	var emulator []string
-	for _, s := range c.Target.Emulator {
-		emulator = append(emulator, strings.ReplaceAll(s, "{root}", goenv.Get("TINYGOROOT")))
+// EmulatorName is a shorthand to get the command for this emulator, something
+// like qemu-system-arm or simavr.
+func (c *Config) EmulatorName() string {
+	parts := strings.SplitN(c.Target.Emulator, " ", 2)
+	if len(parts) > 1 {
+		return parts[0]
 	}
-	return emulator
+	return ""
+}
+
+// EmulatorFormat returns the binary format for the emulator and the associated
+// file extension. An empty string means to pass directly whatever the linker
+// produces directly without conversion (usually ELF format).
+func (c *Config) EmulatorFormat() (format, fileExt string) {
+	switch {
+	case strings.Contains(c.Target.Emulator, "{img}"):
+		return "img", ".img"
+	default:
+		return "", ""
+	}
+}
+
+// Emulator returns a ready-to-run command to run the given binary in an
+// emulator. Give it the format (returned by EmulatorFormat()) and the path to
+// the compiled binary.
+func (c *Config) Emulator(format, binary string) ([]string, error) {
+	parts, err := shlex.Split(c.Target.Emulator)
+	if err != nil {
+		return nil, fmt.Errorf("could not parse emulator command: %w", err)
+	}
+	var emulator []string
+	for _, s := range parts {
+		s = strings.ReplaceAll(s, "{root}", goenv.Get("TINYGOROOT"))
+		s = strings.ReplaceAll(s, "{"+format+"}", binary)
+		emulator = append(emulator, s)
+	}
+	return emulator, nil
 }

 type TestConfig struct {
@@ -28,11 +28,12 @@ type Options struct {
 	PanicStrategy   string
 	Scheduler       string
 	Serial          string
+	Work            bool // -work flag to print temporary build directory
 	PrintIR         bool
 	DumpSSA         bool
 	VerifyIR        bool
-	PrintCommands   func(cmd string, args ...string)
-	Semaphore       chan struct{} // -p flag controls cap
+	PrintCommands   func(cmd string, args ...string) `json:"-"`
+	Semaphore       chan struct{}                    `json:"-"` // -p flag controls cap
 	Debug           bool
 	PrintSizes      string
 	PrintAllocs     *regexp.Regexp // regexp string
@@ -45,6 +46,7 @@ type Options struct {
 	OpenOCDCommands []string
 	LLVMFeatures    string
 	Directory       string
+	PrintJSON       bool
 }

 // Verify performs a validation on the given options, raising an error if options are not valid.
@@ -44,8 +44,8 @@ type TargetSpec struct {
 	LDFlags          []string `json:"ldflags"`
 	LinkerScript     string   `json:"linkerscript"`
 	ExtraFiles       []string `json:"extra-files"`
-	RP2040BootPatch  *bool    `json:"rp2040-boot-patch"`        // Patch RP2040 2nd stage bootloader checksum
-	Emulator         []string `json:"emulator" override:"copy"` // inherited Emulator must not be append
+	RP2040BootPatch  *bool    `json:"rp2040-boot-patch"` // Patch RP2040 2nd stage bootloader checksum
+	Emulator         string   `json:"emulator"`
 	FlashCommand     string   `json:"flash-command"`
 	GDB              []string `json:"gdb"`
 	PortReset        string   `json:"flash-1200-bps-reset"`
@@ -59,6 +59,7 @@ type TargetSpec struct {
 	OpenOCDTarget    string   `json:"openocd-target"`
 	OpenOCDTransport string   `json:"openocd-transport"`
 	OpenOCDCommands  []string `json:"openocd-commands"`
+	OpenOCDVerify    *bool    `json:"openocd-verify"` // enable verify when flashing with openocd
 	JLinkDevice      string   `json:"jlink-device"`
 	CodeModel        string   `json:"code-model"`
 	RelocationModel  string   `json:"relocation-model"`
@@ -89,19 +90,8 @@ func (spec *TargetSpec) overrideProperties(child *TargetSpec) {
 			if !src.IsNil() {
 				dst.Set(src)
 			}
-		case reflect.Slice: // for slices...
-			if src.Len() > 0 { // ... if not empty ...
-				switch tag := field.Tag.Get("override"); tag {
-				case "copy":
-					// copy the field of child to spec
-					dst.Set(src)
-				case "append", "":
-					// or append the field of child to spec
-					dst.Set(reflect.AppendSlice(dst, src))
-				default:
-					panic("override mode must be 'copy' or 'append' (default). I don't know how to '" + tag + "'.")
-				}
-			}
+		case reflect.Slice: // for slices, append the field
+			dst.Set(reflect.AppendSlice(dst, src))
 		default:
 			panic("unknown field type : " + kind.String())
 		}
@@ -258,7 +248,7 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 		spec.Features = "+cx8,+fxsr,+mmx,+sse,+sse2,+x87"
 	case "arm":
 		spec.CPU = "generic"
-		spec.CFlags = append(spec.CFlags, "-fno-unwind-tables")
+		spec.CFlags = append(spec.CFlags, "-fno-unwind-tables", "-fno-asynchronous-unwind-tables")
 		switch strings.Split(triple, "-")[0] {
 		case "armv5":
 			spec.Features = "+armv5t,+strict-align,-aes,-bf16,-d32,-dotprod,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-mve.fp,-neon,-sha2,-thumb-mode,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp"
@@ -272,8 +262,20 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 		spec.Features = "+neon"
 	}
 	if goos == "darwin" {
-		spec.CFlags = append(spec.CFlags, "-isysroot", "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk")
-		spec.LDFlags = append(spec.LDFlags, "-Wl,-dead_strip")
+		spec.Linker = "ld.lld"
+		spec.Libc = "darwin-libSystem"
+		arch := strings.Split(triple, "-")[0]
+		platformVersion := strings.TrimPrefix(strings.Split(triple, "-")[2], "macosx")
+		flavor := "darwin"
+		if strings.Split(llvm.Version, ".")[0] < "13" {
+			flavor = "darwinnew" // needed on LLVM 12 and below
+		}
+		spec.LDFlags = append(spec.LDFlags,
+			"-flavor", flavor,
+			"-dead_strip",
+			"-arch", arch,
+			"-platform_version", "macos", platformVersion, platformVersion,
+		)
 	} else if goos == "linux" {
 		spec.Linker = "ld.lld"
 		spec.RTLib = "compiler-rt"
@@ -317,16 +319,25 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 	if goarch != runtime.GOARCH {
 		// Some educated guesses as to how to invoke helper programs.
 		spec.GDB = []string{"gdb-multiarch"}
-		if goarch == "arm" && goos == "linux" {
-			spec.Emulator = []string{"qemu-arm"}
-		}
-		if goarch == "arm64" && goos == "linux" {
-			spec.Emulator = []string{"qemu-aarch64"}
+		if goos == "linux" {
+			switch goarch {
+			case "386":
+				// amd64 can _usually_ run 32-bit programs, so skip the emulator in that case.
+				if runtime.GOARCH != "amd64" {
+					spec.Emulator = "qemu-i386 {}"
+				}
+			case "amd64":
+				spec.Emulator = "qemu-x86_64 {}"
+			case "arm":
+				spec.Emulator = "qemu-arm {}"
+			case "arm64":
+				spec.Emulator = "qemu-aarch64 {}"
+			}
 		}
 	}
 	if goos != runtime.GOOS {
 		if goos == "windows" {
-			spec.Emulator = []string{"wine"}
+			spec.Emulator = "wine {}"
 		}
 	}
 	return &spec, nil
@@ -29,7 +29,6 @@ func TestOverrideProperties(t *testing.T) {
 		CPU:              "baseCpu",
 		CFlags:           []string{"-base-foo", "-base-bar"},
 		BuildTags:        []string{"bt1", "bt2"},
-		Emulator:         []string{"be1", "be2"},
 		DefaultStackSize: 42,
 		AutoStackSize:    &baseAutoStackSize,
 	}
@@ -38,7 +37,6 @@ func TestOverrideProperties(t *testing.T) {
 		GOOS:             "",
 		CPU:              "chlidCpu",
 		CFlags:           []string{"-child-foo", "-child-bar"},
-		Emulator:         []string{"ce1", "ce2"},
 		AutoStackSize:    &childAutoStackSize,
 		DefaultStackSize: 64,
 	}
@@ -57,9 +55,6 @@ func TestOverrideProperties(t *testing.T) {
 	if !reflect.DeepEqual(base.BuildTags, []string{"bt1", "bt2"}) {
 		t.Errorf("Overriding failed : got %v", base.BuildTags)
 	}
-	if !reflect.DeepEqual(base.Emulator, []string{"ce1", "ce2"}) {
-		t.Errorf("Overriding failed : got %v", base.Emulator)
-	}
 	if *base.AutoStackSize != false {
 		t.Errorf("Overriding failed : got %v", base.AutoStackSize)
 	}
@@ -234,10 +234,15 @@ func Sizes(machine llvm.TargetMachine) types.Sizes {
 		panic("unknown pointer size")
 	}

+	// Construct a complex128 type because that's likely the type with the
+	// biggest alignment on most/all ABIs.
+	ctx := llvm.NewContext()
+	defer ctx.Dispose()
+	complex128Type := ctx.StructType([]llvm.Type{ctx.DoubleType(), ctx.DoubleType()}, false)
 	return &stdSizes{
 		IntSize:  int64(intWidth / 8),
 		PtrSize:  int64(targetData.PointerSize()),
-		MaxAlign: int64(targetData.PrefTypeAlignment(targetData.IntPtrType())),
+		MaxAlign: int64(targetData.ABITypeAlignment(complex128Type)),
 	}
 }

@@ -952,10 +957,10 @@ func (b *builder) createFunction() {
 			} else {
 				fieldOffsets := b.expandFormalParamOffsets(llvmType)
 				for i, field := range fields {
-					expr := b.dibuilder.CreateExpression([]int64{
-						0x1000,                     // DW_OP_LLVM_fragment
-						int64(fieldOffsets[i]) * 8, // offset in bits
-						int64(b.targetData.TypeAllocSize(field.Type())) * 8, // size in bits
+					expr := b.dibuilder.CreateExpression([]uint64{
+						0x1000,              // DW_OP_LLVM_fragment
+						fieldOffsets[i] * 8, // offset in bits
+						b.targetData.TypeAllocSize(field.Type()) * 8, // size in bits
 					})
 					b.dibuilder.InsertValueAtEnd(field, dbgParam, expr, loc, entryBlock)
 				}
@@ -1228,7 +1233,7 @@ func (b *builder) createBuiltin(argTypes []types.Type, argValues []llvm.Value, c
 	case "cap":
 		value := argValues[0]
 		var llvmCap llvm.Value
-		switch argTypes[0].(type) {
+		switch argTypes[0].Underlying().(type) {
 		case *types.Chan:
 			llvmCap = b.createRuntimeCall("chanCap", []llvm.Value{value}, "cap")
 		case *types.Slice:
@@ -1435,7 +1440,7 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.emitSV64Call(instr.Args)
 		case strings.HasPrefix(name, "(device/riscv.CSR)."):
 			return b.emitCSROperation(instr)
-		case strings.HasPrefix(name, "syscall.Syscall"):
+		case strings.HasPrefix(name, "syscall.Syscall") || strings.HasPrefix(name, "syscall.RawSyscall"):
 			return b.createSyscall(instr)
 		case strings.HasPrefix(name, "syscall.rawSyscallNoError"):
 			return b.createRawSyscallNoError(instr)
@@ -1464,6 +1469,14 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 		case *ssa.Function:
 			// Regular function call. No context is necessary.
 			context = llvm.Undef(b.i8ptrType)
+			if info.variadic && len(fn.Params) == 0 {
+				// This matches Clang, see: https://godbolt.org/z/Gqv49xKMq
+				// Eventually we might be able to eliminate this special case
+				// entirely. For details, see:
+				// https://discourse.llvm.org/t/rfc-enabling-wstrict-prototypes-by-default-in-c/60521
+				fnType := llvm.FunctionType(callee.Type().ElementType().ReturnType(), nil, false)
+				callee = llvm.ConstBitCast(callee, llvm.PointerType(fnType, b.funcPtrAddrSpace))
+			}
 		case *ssa.MakeClosure:
 			// A call on a func value, but the callee is trivial to find. For
 			// example: immediately applied functions.
@@ -1549,7 +1562,11 @@ func (c *compilerContext) maxSliceSize(elementType llvm.Type) uint64 {
 	// Determine the maximum allowed size for a slice. The biggest possible
 	// pointer (starting from 0) would be maxPointerValue*sizeof(elementType) so
 	// divide by the element type to get the real maximum size.
-	maxSize := maxPointerValue / c.targetData.TypeAllocSize(elementType)
+	elementSize := c.targetData.TypeAllocSize(elementType)
+	if elementSize == 0 {
+		elementSize = 1
+	}
+	maxSize := maxPointerValue / elementSize

 	// len(slice) is an int. Make sure the length remains small enough to fit in
 	// an int.
@@ -1571,8 +1588,9 @@ func (b *builder) createExpr(expr ssa.Value) (llvm.Value, error) {
 	switch expr := expr.(type) {
 	case *ssa.Alloc:
 		typ := b.getLLVMType(expr.Type().Underlying().(*types.Pointer).Elem())
-		if expr.Heap {
-			size := b.targetData.TypeAllocSize(typ)
+		size := b.targetData.TypeAllocSize(typ)
+		// Move all "large" allocations to the heap.  This value is also transform.maxStackAlloc.
+		if expr.Heap || size > 256 {
 			// Calculate ^uintptr(0)
 			maxSize := llvm.ConstNot(llvm.ConstInt(b.uintptrType, 0, false)).ZExtValue()
 			if size > maxSize {
@@ -226,9 +226,9 @@ func filterIrrelevantIRLines(lines []string) []string {
 			// Right now test outputs are for LLVM 12 and higher.
 			continue
 		}
-		if llvmVersion < 13 && strings.HasPrefix(line, "target datalayout = ") {
+		if llvmVersion < 14 && strings.HasPrefix(line, "target datalayout = ") {
 			// The datalayout string may vary betewen LLVM versions.
-			// Right now test outputs are for LLVM 13 and higher.
+			// Right now test outputs are for LLVM 14 and higher.
 			continue
 		}
 		out = append(out, line)
@@ -98,7 +98,10 @@ func (b *builder) createInlineAsmFull(instr *ssa.CallCommon) (llvm.Value, error)
 			case llvm.IntegerTypeKind:
 				constraints = append(constraints, "r")
 			case llvm.PointerTypeKind:
-				constraints = append(constraints, "*m")
+				// Memory references require a type in LLVM 14, probably as a
+				// preparation for opaque pointers.
+				err = b.makeError(instr.Pos(), "support for pointer operands was dropped in TinyGo 0.23")
+				return s
 			default:
 				err = b.makeError(instr.Pos(), "unknown type in inline assembly for value: "+name)
 				return s
@@ -152,6 +152,27 @@ func (c *compilerContext) makeStructTypeFields(typ *types.Struct) llvm.Value {
 	return structGlobal
 }

+var basicTypes = [...]string{
+	types.Bool:          "bool",
+	types.Int:           "int",
+	types.Int8:          "int8",
+	types.Int16:         "int16",
+	types.Int32:         "int32",
+	types.Int64:         "int64",
+	types.Uint:          "uint",
+	types.Uint8:         "uint8",
+	types.Uint16:        "uint16",
+	types.Uint32:        "uint32",
+	types.Uint64:        "uint64",
+	types.Uintptr:       "uintptr",
+	types.Float32:       "float32",
+	types.Float64:       "float64",
+	types.Complex64:     "complex64",
+	types.Complex128:    "complex128",
+	types.String:        "string",
+	types.UnsafePointer: "unsafe.Pointer",
+}
+
 // getTypeCodeName returns a name for this type that can be used in the
 // interface lowering pass to assign type codes as expected by the reflect
 // package. See getTypeCodeNum.
@@ -162,48 +183,7 @@ func getTypeCodeName(t types.Type) string {
 	case *types.Array:
 		return "array:" + strconv.FormatInt(t.Len(), 10) + ":" + getTypeCodeName(t.Elem())
 	case *types.Basic:
-		var kind string
-		switch t.Kind() {
-		case types.Bool:
-			kind = "bool"
-		case types.Int:
-			kind = "int"
-		case types.Int8:
-			kind = "int8"
-		case types.Int16:
-			kind = "int16"
-		case types.Int32:
-			kind = "int32"
-		case types.Int64:
-			kind = "int64"
-		case types.Uint:
-			kind = "uint"
-		case types.Uint8:
-			kind = "uint8"
-		case types.Uint16:
-			kind = "uint16"
-		case types.Uint32:
-			kind = "uint32"
-		case types.Uint64:
-			kind = "uint64"
-		case types.Uintptr:
-			kind = "uintptr"
-		case types.Float32:
-			kind = "float32"
-		case types.Float64:
-			kind = "float64"
-		case types.Complex64:
-			kind = "complex64"
-		case types.Complex128:
-			kind = "complex128"
-		case types.String:
-			kind = "string"
-		case types.UnsafePointer:
-			kind = "unsafeptr"
-		default:
-			panic("unknown basic type: " + t.Name())
-		}
-		return "basic:" + kind
+		return "basic:" + basicTypes[t.Kind()]
 	case *types.Chan:
 		return "chan:" + getTypeCodeName(t.Elem())
 	case *types.Interface:
@@ -591,23 +571,77 @@ func signature(sig *types.Signature) string {
 			if i > 0 {
 				s += ", "
 			}
-			s += sig.Params().At(i).Type().String()
+			s += typestring(sig.Params().At(i).Type())
 		}
 		s += ")"
 	}
 	if sig.Results().Len() == 0 {
 		// keep as-is
 	} else if sig.Results().Len() == 1 {
-		s += " " + sig.Results().At(0).Type().String()
+		s += " " + typestring(sig.Results().At(0).Type())
 	} else {
 		s += " ("
 		for i := 0; i < sig.Results().Len(); i++ {
 			if i > 0 {
 				s += ", "
 			}
-			s += sig.Results().At(i).Type().String()
+			s += typestring(sig.Results().At(i).Type())
 		}
 		s += ")"
 	}
 	return s
 }
+
+// typestring returns a stable (human-readable) type string for the given type
+// that can be used for interface equality checks. It is almost (but not
+// exactly) the same as calling t.String(). The main difference is some
+// normalization around `byte` vs `uint8` for example.
+func typestring(t types.Type) string {
+	// See: https://github.com/golang/go/blob/master/src/go/types/typestring.go
+	switch t := t.(type) {
+	case *types.Array:
+		return "[" + strconv.FormatInt(t.Len(), 10) + "]" + typestring(t.Elem())
+	case *types.Basic:
+		return basicTypes[t.Kind()]
+	case *types.Chan:
+		switch t.Dir() {
+		case types.SendRecv:
+			return "chan (" + typestring(t.Elem()) + ")"
+		case types.SendOnly:
+			return "chan<- (" + typestring(t.Elem()) + ")"
+		case types.RecvOnly:
+			return "<-chan (" + typestring(t.Elem()) + ")"
+		default:
+			panic("unknown channel direction")
+		}
+	case *types.Interface:
+		methods := make([]string, t.NumMethods())
+		for i := range methods {
+			method := t.Method(i)
+			methods[i] = method.Name() + signature(method.Type().(*types.Signature))
+		}
+		return "interface{" + strings.Join(methods, ";") + "}"
+	case *types.Map:
+		return "map[" + typestring(t.Key()) + "]" + typestring(t.Elem())
+	case *types.Named:
+		return t.String()
+	case *types.Pointer:
+		return "*" + typestring(t.Elem())
+	case *types.Signature:
+		return "func" + signature(t)
+	case *types.Slice:
+		return "[]" + typestring(t.Elem())
+	case *types.Struct:
+		fields := make([]string, t.NumFields())
+		for i := range fields {
+			field := t.Field(i)
+			fields[i] = field.Name() + " " + typestring(field.Type())
+			if tag := t.Tag(i); tag != "" {
+				fields[i] += " " + strconv.Quote(tag)
+			}
+		}
+		return "struct{" + strings.Join(fields, ";") + "}"
+	default:
+		panic("unknown type: " + t.String())
+	}
+}
@@ -31,7 +31,7 @@ func (c *checker) checkType(t llvm.Type, checked map[llvm.Type]struct{}, special
 		return fmt.Errorf("type %q uses global context", t.String())
 	default:
 		// we used some other context by accident
-		return fmt.Errorf("type %q uses context %v instead of the main context %v", t.Context(), c.ctx)
+		return fmt.Errorf("type %q uses context %v instead of the main context %v", t.String(), t.Context(), c.ctx)
 	}

 	// if this is a composite type, check the components of the type
@@ -10,6 +10,13 @@ import (
 	"tinygo.org/x/go-llvm"
 )

+// constants for hashmap algorithms; must match src/runtime/hashmap.go
+const (
+	hashmapAlgorithmBinary = iota
+	hashmapAlgorithmString
+	hashmapAlgorithmInterface
+)
+
 // createMakeMap creates a new map object (runtime.hashmap) by allocating and
 // initializing an appropriately sized object.
 func (b *builder) createMakeMap(expr *ssa.MakeMap) (llvm.Value, error) {
@@ -17,22 +24,27 @@ func (b *builder) createMakeMap(expr *ssa.MakeMap) (llvm.Value, error) {
 	keyType := mapType.Key().Underlying()
 	llvmValueType := b.getLLVMType(mapType.Elem().Underlying())
 	var llvmKeyType llvm.Type
+	var alg uint64 // must match values in src/runtime/hashmap.go
 	if t, ok := keyType.(*types.Basic); ok && t.Info()&types.IsString != 0 {
 		// String keys.
 		llvmKeyType = b.getLLVMType(keyType)
+		alg = hashmapAlgorithmString
 	} else if hashmapIsBinaryKey(keyType) {
 		// Trivially comparable keys.
 		llvmKeyType = b.getLLVMType(keyType)
+		alg = hashmapAlgorithmBinary
 	} else {
 		// All other keys. Implemented as map[interface{}]valueType for ease of
 		// implementation.
 		llvmKeyType = b.getLLVMRuntimeType("_interface")
+		alg = hashmapAlgorithmInterface
 	}
 	keySize := b.targetData.TypeAllocSize(llvmKeyType)
 	valueSize := b.targetData.TypeAllocSize(llvmValueType)
 	llvmKeySize := llvm.ConstInt(b.ctx.Int8Type(), keySize, false)
 	llvmValueSize := llvm.ConstInt(b.ctx.Int8Type(), valueSize, false)
 	sizeHint := llvm.ConstInt(b.uintptrType, 8, false)
+	algEnum := llvm.ConstInt(b.ctx.Int8Type(), alg, false)
 	if expr.Reserve != nil {
 		sizeHint = b.getValue(expr.Reserve)
 		var err error
@@ -41,7 +53,7 @@ func (b *builder) createMakeMap(expr *ssa.MakeMap) (llvm.Value, error) {
 			return llvm.Value{}, err
 		}
 	}
-	hashmap := b.createRuntimeCall("hashmapMake", []llvm.Value{llvmKeySize, llvmValueSize, sizeHint}, "")
+	hashmap := b.createRuntimeCall("hashmapMake", []llvm.Value{llvmKeySize, llvmValueSize, sizeHint, algEnum}, "")
 	return hashmap, nil
 }

@@ -1,6 +1,6 @@
 ; ModuleID = 'basic.go'
 source_filename = "basic.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %main.kv = type { float }
@@ -1,6 +1,6 @@
 ; ModuleID = 'channel.go'
 source_filename = "channel.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime.channel = type { i32, i32, i8, %runtime.channelBlockedList*, i32, i32, i32, i8* }
@@ -1,6 +1,6 @@
 ; ModuleID = 'float.go'
 source_filename = "float.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'func.go'
 source_filename = "func.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'gc.go'
 source_filename = "gc.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo*, %runtime.typecodeID*, i32 }
@@ -1,6 +1,6 @@
 ; ModuleID = 'go1.17.go'
 source_filename = "go1.17.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'goroutine.go'
 source_filename = "goroutine.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime.channel = type { i32, i32, i8, %runtime.channelBlockedList*, i32, i32, i32, i8* }
@@ -1,6 +1,6 @@
 ; ModuleID = 'interface.go'
 source_filename = "interface.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime.typecodeID = type { %runtime.typecodeID*, i32, %runtime.interfaceMethodInfo*, %runtime.typecodeID*, i32 }
@@ -128,5 +128,5 @@ declare %runtime._string @"interface:{Error:func:{}{basic:string}}.Error$invoke"
 attributes #0 = { nounwind }
 attributes #1 = { "tinygo-methods"="reflect/methods.Error() string" }
 attributes #2 = { "tinygo-methods"="reflect/methods.String() string" }
-attributes #3 = { "tinygo-invoke"="main.$methods.foo(int) byte" "tinygo-methods"="reflect/methods.String() string; main.$methods.foo(int) byte" }
+attributes #3 = { "tinygo-invoke"="main.$methods.foo(int) uint8" "tinygo-methods"="reflect/methods.String() string; main.$methods.foo(int) uint8" }
 attributes #4 = { "tinygo-invoke"="reflect/methods.Error() string" "tinygo-methods"="reflect/methods.Error() string" }
@@ -1,6 +1,6 @@
 ; ModuleID = 'intrinsics.go'
 source_filename = "intrinsics.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'pointer.go'
 source_filename = "pointer.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'pragma.go'
 source_filename = "pragma.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

@extern_global = external global [0 x i8], align 1
@@ -1,6 +1,6 @@
 ; ModuleID = 'slice.go'
 source_filename = "slice.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -1,6 +1,6 @@
 ; ModuleID = 'string.go'
 source_filename = "string.go"
-target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._string = type { i8*, i32 }
@@ -15,5 +15,5 @@ require (
 	golang.org/x/sys v0.0.0-20220114195835-da31bd327af9
 	golang.org/x/tools v0.1.6-0.20210813165731-45389f592fe9
 	gopkg.in/yaml.v2 v2.4.0
-	tinygo.org/x/go-llvm v0.0.0-20220121152956-4fa2ab2718f3
+	tinygo.org/x/go-llvm v0.0.0-20220420140351-512c94c1e71f
 )
@@ -80,5 +80,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
-tinygo.org/x/go-llvm v0.0.0-20220121152956-4fa2ab2718f3 h1:vQSFy0kNQegAfL/F6iyWQa4bF941Xc1gyJUkGy2m448=
-tinygo.org/x/go-llvm v0.0.0-20220121152956-4fa2ab2718f3/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=
+tinygo.org/x/go-llvm v0.0.0-20220420140351-512c94c1e71f h1:9/J+NpFTpAhYcbh1mC4dr9W/aAPnwrUh8dmq21xWdSM=
+tinygo.org/x/go-llvm v0.0.0-20220420140351-512c94c1e71f/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=
@@ -12,7 +12,13 @@ import (

 // Version of TinyGo.
 // Update this value before release of new version of software.
-const Version = "0.22.0"
+const Version = "0.23.0"
+
+var (
+	// This variable is set at build time using -ldflags parameters.
+	// See: https://stackoverflow.com/a/11355611
+	GitSha1 string
+)

 // GetGorootVersion returns the major and minor version for a given GOROOT path.
 // If the goroot cannot be determined, (0, 0) is returned.
@@ -52,9 +58,9 @@ func GorootVersionString(goroot string) (string, error) {
 		return string(data), nil

 	} else if data, err := ioutil.ReadFile(filepath.Join(
-		goroot, "src", "runtime", "internal", "sys", "zversion.go")); err == nil {
+		goroot, "src", "internal", "buildcfg", "zbootstrap.go")); err == nil {

-		r := regexp.MustCompile("const TheVersion = `(.*)`")
+		r := regexp.MustCompile("const version = `(.*)`")
 		matches := r.FindSubmatch(data)
 		if len(matches) != 2 {
 			return "", errors.New("Invalid go version output:\n" + string(data))
@@ -492,9 +492,9 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 				// Call a function with a definition available. Run it as usual,
 				// possibly trying to recover from it if it failed to execute.
 				if r.debug {
-					argStrings := make([]string, len(operands))
-					for i := range argStrings {
-						argStrings[i] = operands[i+1].String()
+					argStrings := make([]string, len(operands)-1)
+					for i, v := range operands[1:] {
+						argStrings[i] = v.String()
 					}
 					fmt.Fprintln(os.Stderr, indent+"call:", callFn.name+"("+strings.Join(argStrings, ", ")+")")
 				}
@@ -1,8 +1,6 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64--linux"

-@"main$alloc.1" = internal unnamed_addr constant [6 x i8] c"\05\00{\00\00\04", align 8
-
 declare void @runtime.printuint8(i8) local_unnamed_addr

 declare void @runtime.printint16(i16) local_unnamed_addr
@@ -17,7 +15,6 @@ entry:
  call void @runtime.printuint8(i8 3)
  call void @runtime.printuint8(i8 3)
  call void @runtime.printint16(i16 5)
-  %int16SliceDst.val = load i16, i16* bitcast ([6 x i8]* @"main$alloc.1" to i16*), align 2
-  call void @runtime.printint16(i16 %int16SliceDst.val)
+  call void @runtime.printint16(i16 5)
  ret void
 }
@@ -230,6 +230,7 @@ func pathsToOverride(needsSyscallPackage bool) map[string]bool {
 		"device/":               false,
 		"examples/":             false,
 		"internal/":             true,
+		"internal/fuzz/":        false,
 		"internal/bytealg/":     false,
 		"internal/reflectlite/": false,
 		"internal/task/":        false,
@@ -418,10 +418,7 @@ func (p *Package) parseFiles() ([]*ast.File, error) {
 		var initialCFlags []string
 		initialCFlags = append(initialCFlags, p.program.config.CFlags()...)
 		initialCFlags = append(initialCFlags, "-I"+p.Dir)
-		if p.program.clangHeaders != "" {
-			initialCFlags = append(initialCFlags, "-isystem", p.program.clangHeaders)
-		}
-		generated, headerCode, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.program.fset, initialCFlags)
+		generated, headerCode, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.program.fset, initialCFlags, p.program.clangHeaders)
 		p.CFlags = append(initialCFlags, cflags...)
 		p.CGoHeaders = headerCode
 		for path, hash := range accessedFiles {
@@ -2,6 +2,7 @@ package main

 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"flag"
@@ -36,12 +37,6 @@ import (
 	"go.bug.st/serial/enumerator"
 )

-var (
-	// This variable is set at build time using -ldflags parameters.
-	// See: https://stackoverflow.com/a/11355611
-	gitSha1 string
-)
-
 // commandError is an error type to wrap os/exec.Command errors. This provides
 // some more information regarding what went wrong while running a command.
 type commandError struct {
@@ -148,7 +143,27 @@ func Build(pkgName, outpath string, options *compileopts.Options) error {
 		return err
 	}

+	if options.PrintJSON {
+		b, err := json.MarshalIndent(config, "", "  ")
+		if err != nil {
+			handleCompilerError(err)
+		}
+		fmt.Printf("%s\n", string(b))
+		return nil
+	}
+
 	return builder.Build(pkgName, outpath, config, func(result builder.BuildResult) error {
+		if outpath == "" {
+			if strings.HasSuffix(pkgName, ".go") {
+				// A Go file was specified directly on the command line.
+				// Base the binary name off of it.
+				outpath = filepath.Base(pkgName[:len(pkgName)-3]) + config.DefaultBinaryExtension()
+			} else {
+				// Pick a default output path based on the main directory.
+				outpath = filepath.Base(result.MainDir) + config.DefaultBinaryExtension()
+			}
+		}
+
 		if err := os.Rename(result.Binary, outpath); err != nil {
 			// Moving failed. Do a file copy.
 			inf, err := os.Open(result.Binary)
@@ -185,8 +200,26 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 		return false, err
 	}

+	// Pass test flags to the test binary.
+	var flags []string
+	if testVerbose {
+		flags = append(flags, "-test.v")
+	}
+	if testShort {
+		flags = append(flags, "-test.short")
+	}
+	if testRunRegexp != "" {
+		flags = append(flags, "-test.run="+testRunRegexp)
+	}
+	if testBenchRegexp != "" {
+		flags = append(flags, "-test.bench="+testBenchRegexp)
+	}
+	if testBenchTime != "" {
+		flags = append(flags, "-test.benchtime="+testBenchTime)
+	}
+
 	passed := false
-	err = builder.Build(pkgName, outpath, config, func(result builder.BuildResult) error {
+	err = buildAndRun(pkgName, config, os.Stdout, flags, nil, 0, func(cmd *exec.Cmd, result builder.BuildResult) error {
 		if testCompileOnly || outpath != "" {
 			// Write test binary to the specified file name.
 			if outpath == "" {
@@ -202,27 +235,52 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 			return nil
 		}

-		// Run the test.
-		config.Options.Semaphore <- struct{}{}
-		defer func() {
-			<-config.Options.Semaphore
-		}()
-		start := time.Now()
-		var err error
-		passed, err = runPackageTest(config, stdout, stderr, result, testVerbose, testShort, testRunRegexp, testBenchRegexp, testBenchTime)
-		if err != nil {
-			return err
+		// Tests are always run in the package directory.
+		cmd.Dir = result.MainDir
+
+		// Wasmtime needs a few extra flags to work.
+		if config.EmulatorName() == "wasmtime" {
+			// Add directories to the module root, but skip the current working
+			// directory which is already added by buildAndRun.
+			dirs := dirsToModuleRoot(result.MainDir, result.ModuleRoot)
+			var args []string
+			for _, d := range dirs[1:] {
+				args = append(args, "--dir="+d)
+			}
+
+			// create a new temp directory just for this run, announce it to os.TempDir() via TMPDIR
+			tmpdir, err := ioutil.TempDir("", "tinygotmp")
+			if err != nil {
+				return fmt.Errorf("failed to create temporary directory: %w", err)
+			}
+			args = append(args, "--dir="+tmpdir, "--env=TMPDIR="+tmpdir)
+			// TODO: add option to not delete temp dir for debugging?
+			defer os.RemoveAll(tmpdir)
+
+			// Insert new argments at the front of the command line argments.
+			args = append(args, cmd.Args[1:]...)
+			cmd.Args = append(cmd.Args[:1:1], args...)
 		}
+
+		// Run the test.
+		start := time.Now()
+		err = cmd.Run()
 		duration := time.Since(start)

 		// Print the result.
 		importPath := strings.TrimSuffix(result.ImportPath, ".test")
+		passed = err == nil
 		if passed {
 			fmt.Fprintf(stdout, "ok  \t%s\t%.3fs\n", importPath, duration.Seconds())
 		} else {
 			fmt.Fprintf(stdout, "FAIL\t%s\t%.3fs\n", importPath, duration.Seconds())
 		}
-		return nil
+		if _, ok := err.(*exec.ExitError); ok {
+			// Binary exited with a non-zero exit code, which means the test
+			// failed.
+			return nil
+		}
+		return err
 	})
 	if err, ok := err.(loader.NoTestFilesError); ok {
 		fmt.Fprintf(stdout, "?   \t%s\t[no test files]\n", err.ImportPath)
@@ -245,81 +303,6 @@ func dirsToModuleRoot(maindir, modroot string) []string {
 	return dirs
 }

-// runPackageTest runs a test binary that was previously built. The return
-// values are whether the test passed and any errors encountered while trying to
-// run the binary.
-func runPackageTest(config *compileopts.Config, stdout, stderr io.Writer, result builder.BuildResult, testVerbose, testShort bool, testRunRegexp string, testBenchRegexp string, testBenchTime string) (bool, error) {
-	var cmd *exec.Cmd
-	emulator := config.Emulator()
-	if len(emulator) == 0 {
-		// Run directly.
-		var flags []string
-		if testVerbose {
-			flags = append(flags, "-test.v")
-		}
-		if testShort {
-			flags = append(flags, "-test.short")
-		}
-		if testRunRegexp != "" {
-			flags = append(flags, "-test.run="+testRunRegexp)
-		}
-		if testBenchRegexp != "" {
-			flags = append(flags, "-test.bench="+testBenchRegexp)
-		}
-		if testBenchTime != "" {
-			flags = append(flags, "-test.benchtime="+testBenchTime)
-		}
-		cmd = executeCommand(config.Options, result.Binary, flags...)
-	} else {
-		// Run in an emulator.
-		args := append(emulator[1:], result.Binary)
-		if emulator[0] == "wasmtime" {
-			// create a new temp directory just for this run, announce it to os.TempDir() via TMPDIR
-			tmpdir, err := ioutil.TempDir("", "tinygotmp")
-			if err != nil {
-				return false, &commandError{"failed to create temporary directory", "tinygotmp", err}
-			}
-			args = append(args, "--dir="+tmpdir, "--env=TMPDIR="+tmpdir)
-			// TODO: add option to not delete temp dir for debugging?
-			defer os.RemoveAll(tmpdir)
-
-			// allow reading from directories up to module root
-			for _, d := range dirsToModuleRoot(result.MainDir, result.ModuleRoot) {
-				args = append(args, "--dir="+d)
-			}
-
-			// mark end of wasmtime arguments and start of program ones: --
-			args = append(args, "--")
-			if testVerbose {
-				args = append(args, "-test.v")
-			}
-			if testShort {
-				args = append(args, "-test.short")
-			}
-			if testRunRegexp != "" {
-				args = append(args, "-test.run="+testRunRegexp)
-			}
-			if testBenchRegexp != "" {
-				args = append(args, "-test.bench="+testBenchRegexp)
-			}
-		}
-		cmd = executeCommand(config.Options, emulator[0], args...)
-	}
-	cmd.Dir = result.MainDir
-	cmd.Stdout = stdout
-	cmd.Stderr = stderr
-	err := cmd.Run()
-	if err != nil {
-		if _, ok := err.(*exec.ExitError); ok {
-			// Binary exited with a non-zero exit code, which means the test
-			// failed.
-			return false, nil
-		}
-		return false, &commandError{"failed to run compiled binary", result.Binary, err}
-	}
-	return true, nil
-}
-
 // Flash builds and flashes the built binary to the given serial port.
 func Flash(pkgName, port string, options *compileopts.Options) error {
 	config, err := builder.NewConfig(options)
@@ -439,7 +422,11 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return err
 			}
-			args = append(args, "-c", "program "+filepath.ToSlash(result.Binary)+" reset exit")
+			exit := " reset exit"
+			if config.Target.OpenOCDVerify != nil && *config.Target.OpenOCDVerify {
+				exit = " verify" + exit
+			}
+			args = append(args, "-c", "program "+filepath.ToSlash(result.Binary)+exit)
 			cmd := executeCommand(config.Options, "openocd", args...)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
@@ -496,18 +483,19 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 		return err
 	}

-	return builder.Build(pkgName, "", config, func(result builder.BuildResult) error {
+	format, fileExt := config.EmulatorFormat()
+	return builder.Build(pkgName, fileExt, config, func(result builder.BuildResult) error {
 		// Find a good way to run GDB.
 		gdbInterface, openocdInterface := config.Programmer()
 		switch gdbInterface {
 		case "msd", "command", "":
-			emulator := config.Emulator()
-			if len(emulator) != 0 {
-				if emulator[0] == "mgba" {
+			emulator := config.EmulatorName()
+			if emulator != "" {
+				if emulator == "mgba" {
 					gdbInterface = "mgba"
-				} else if emulator[0] == "simavr" {
+				} else if emulator == "simavr" {
 					gdbInterface = "simavr"
-				} else if strings.HasPrefix(emulator[0], "qemu-system-") {
+				} else if strings.HasPrefix(emulator, "qemu-system-") {
 					gdbInterface = "qemu"
 				} else {
 					// Assume QEMU as an emulator.
@@ -526,6 +514,10 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 		port := ""
 		var gdbCommands []string
 		var daemon *exec.Cmd
+		emulator, err := config.Emulator(format, result.Binary)
+		if err != nil {
+			return err
+		}
 		switch gdbInterface {
 		case "native":
 			// Run GDB directly.
@@ -575,33 +567,29 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 			}
 		case "qemu":
 			port = ":1234"
-			emulator := config.Emulator()
 			// Run in an emulator.
-			args := append(emulator[1:], result.Binary, "-s", "-S")
+			args := append(emulator[1:], "-s", "-S")
 			daemon = executeCommand(config.Options, emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
 		case "qemu-user":
 			port = ":1234"
-			emulator := config.Emulator()
 			// Run in an emulator.
-			args := append(emulator[1:], "-g", "1234", result.Binary)
+			args := append(emulator[1:], "-g", "1234")
 			daemon = executeCommand(config.Options, emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
 		case "mgba":
 			port = ":2345"
-			emulator := config.Emulator()
 			// Run in an emulator.
-			args := append(emulator[1:], result.Binary, "-g")
+			args := append(emulator[1:], "-g")
 			daemon = executeCommand(config.Options, emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
 		case "simavr":
 			port = ":1234"
-			emulator := config.Emulator()
 			// Run in an emulator.
-			args := append(emulator[1:], "-g", result.Binary)
+			args := append(emulator[1:], "-g")
 			daemon = executeCommand(config.Options, emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
@@ -646,7 +634,7 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 		// Construct and execute a gdb or lldb command.
 		// By default: gdb -ex run <binary>
 		// Exit the debugger with Ctrl-D.
-		params := []string{result.Binary}
+		params := []string{result.Executable}
 		switch debugger {
 		case "gdb":
 			if port != "" {
@@ -678,9 +666,9 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 		cmd.Stdin = os.Stdin
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
-		err := cmd.Run()
+		err = cmd.Run()
 		if err != nil {
-			return &commandError{"failed to run " + cmdName + " with", result.Binary, err}
+			return &commandError{"failed to run " + cmdName + " with", result.Executable, err}
 		}
 		return nil
 	})
@@ -690,44 +678,134 @@ func Debug(debugger, pkgName string, ocdOutput bool, options *compileopts.Option
 // the options, it will run the program directly on the host or will run it in
 // an emulator. For example, -target=wasm will cause the binary to be run inside
 // of a WebAssembly VM.
-func Run(pkgName string, options *compileopts.Options) error {
+func Run(pkgName string, options *compileopts.Options, cmdArgs []string) error {
 	config, err := builder.NewConfig(options)
 	if err != nil {
 		return err
 	}

-	return builder.Build(pkgName, ".elf", config, func(result builder.BuildResult) error {
-		emulator := config.Emulator()
-		if len(emulator) == 0 {
-			// Run directly.
-			cmd := executeCommand(config.Options, result.Binary)
-			cmd.Stdout = os.Stdout
-			cmd.Stderr = os.Stderr
-			err := cmd.Run()
-			if err != nil {
-				if err, ok := err.(*exec.ExitError); ok && err.Exited() {
-					// Workaround for QEMU which always exits with an error.
-					return nil
-				}
-				return &commandError{"failed to run compiled binary", result.Binary, err}
-			}
-			return nil
-		} else {
-			// Run in an emulator.
-			args := append(emulator[1:], result.Binary)
-			cmd := executeCommand(config.Options, emulator[0], args...)
-			cmd.Stdout = os.Stdout
-			cmd.Stderr = os.Stderr
-			err := cmd.Run()
-			if err != nil {
-				if err, ok := err.(*exec.ExitError); ok && err.Exited() {
-					// Workaround for QEMU which always exits with an error.
-					return nil
-				}
-				return &commandError{"failed to run emulator with", result.Binary, err}
-			}
-			return nil
+	return buildAndRun(pkgName, config, os.Stdout, cmdArgs, nil, 0, func(cmd *exec.Cmd, result builder.BuildResult) error {
+		return cmd.Run()
+	})
+}
+
+// buildAndRun builds and runs the given program, writing output to stdout and
+// errors to os.Stderr. It takes care of emulators (qemu, wasmtime, etc) and
+// passes command line arguments and evironment variables in a way appropriate
+// for the given emulator.
+func buildAndRun(pkgName string, config *compileopts.Config, stdout io.Writer, cmdArgs, environmentVars []string, timeout time.Duration, run func(cmd *exec.Cmd, result builder.BuildResult) error) error {
+	// Determine whether we're on a system that supports environment variables
+	// and command line parameters (operating systems, WASI) or not (baremetal,
+	// WebAssembly in the browser). If we're on a system without an environment,
+	// we need to pass command line arguments and environment variables through
+	// global variables (built into the binary directly) instead of the
+	// conventional way.
+	needsEnvInVars := config.GOOS() == "js"
+	for _, tag := range config.BuildTags() {
+		if tag == "baremetal" {
+			needsEnvInVars = true
 		}
+	}
+	var args, env []string
+	if needsEnvInVars {
+		runtimeGlobals := make(map[string]string)
+		if len(cmdArgs) != 0 {
+			runtimeGlobals["osArgs"] = strings.Join(cmdArgs, "\x00")
+		}
+		if len(environmentVars) != 0 {
+			runtimeGlobals["osEnv"] = strings.Join(environmentVars, "\x00")
+		}
+		if len(runtimeGlobals) != 0 {
+			// This sets the global variables like they would be set with
+			// `-ldflags="-X=runtime.osArgs=first\x00second`.
+			// The runtime package has two variables (osArgs and osEnv) that are
+			// both strings, from which the parameters and environment variables
+			// are read.
+			config.Options.GlobalValues = map[string]map[string]string{
+				"runtime": runtimeGlobals,
+			}
+		}
+	} else if config.EmulatorName() == "wasmtime" {
+		// Wasmtime needs some special flags to pass environment variables
+		// and allow reading from the current directory.
+		args = append(args, "--dir=.")
+		for _, v := range environmentVars {
+			args = append(args, "--env", v)
+		}
+		if len(cmdArgs) != 0 {
+			// mark end of wasmtime arguments and start of program ones: --
+			args = append(args, "--")
+			args = append(args, cmdArgs...)
+		}
+	} else {
+		// Pass environment variables and command line parameters as usual.
+		// This also works on qemu-aarch64 etc.
+		args = cmdArgs
+		env = environmentVars
+	}
+
+	format, fileExt := config.EmulatorFormat()
+	return builder.Build(pkgName, fileExt, config, func(result builder.BuildResult) error {
+		// If needed, set a timeout on the command. This is done in tests so
+		// they don't waste resources on a stalled test.
+		var ctx context.Context
+		if timeout != 0 {
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithTimeout(context.Background(), timeout)
+			defer cancel()
+		}
+
+		// Set up the command.
+		var name string
+		if config.Target.Emulator == "" {
+			name = result.Binary
+		} else {
+			emulator, err := config.Emulator(format, result.Binary)
+			if err != nil {
+				return err
+			}
+			name = emulator[0]
+			emuArgs := append([]string(nil), emulator[1:]...)
+			args = append(emuArgs, args...)
+		}
+		var cmd *exec.Cmd
+		if ctx != nil {
+			cmd = exec.CommandContext(ctx, name, args...)
+		} else {
+			cmd = exec.Command(name, args...)
+		}
+		cmd.Env = env
+
+		// Configure stdout/stderr. The stdout may go to a buffer, not a real
+		// stdout.
+		cmd.Stdout = stdout
+		cmd.Stderr = os.Stderr
+		if config.EmulatorName() == "simavr" {
+			cmd.Stdout = nil // don't print initial load commands
+			cmd.Stderr = stdout
+		}
+
+		// If this is a test, reserve CPU time for it so that increased
+		// parallelism doesn't blow up memory usage. If this isn't a test but
+		// simply `tinygo run`, then it is practically a no-op.
+		config.Options.Semaphore <- struct{}{}
+		defer func() {
+			<-config.Options.Semaphore
+		}()
+
+		// Run binary.
+		if config.Options.PrintCommands != nil {
+			config.Options.PrintCommands(cmd.Path, cmd.Args...)
+		}
+		err := run(cmd, result)
+		if err != nil {
+			if ctx != nil && ctx.Err() == context.DeadlineExceeded {
+				stdout.Write([]byte(fmt.Sprintf("--- timeout of %s exceeded, terminating...\n", timeout)))
+				err = ctx.Err()
+			}
+			return &commandError{"failed to run compiled binary", result.Binary, err}
+		}
+		return nil
 	})
 }

@@ -1012,8 +1090,8 @@ func getBMPPorts() (gdbPort, uartPort string, err error) {

 func usage(command string) {
 	version := goenv.Version
-	if strings.HasSuffix(version, "-dev") && gitSha1 != "" {
-		version += "-" + gitSha1
+	if strings.HasSuffix(version, "-dev") && goenv.GitSha1 != "" {
+		version += "-" + goenv.GitSha1
 	}

 	switch command {
@@ -1187,6 +1265,7 @@ func main() {
 	panicStrategy := flag.String("panic", "print", "panic strategy (print, trap)")
 	scheduler := flag.String("scheduler", "", "which scheduler to use (none, tasks, asyncify)")
 	serial := flag.String("serial", "", "which serial output to use (none, uart, usb)")
+	work := flag.Bool("work", false, "print the name of the temporary build directory and do not delete this directory on exit")
 	printIR := flag.Bool("printir", false, "print LLVM IR")
 	dumpSSA := flag.Bool("dumpssa", false, "dump internal Go SSA")
 	verifyIR := flag.Bool("verifyir", false, "run extra verification steps on LLVM IR")
@@ -1207,13 +1286,13 @@ func main() {
 	llvmFeatures := flag.String("llvm-features", "", "comma separated LLVM features to enable")
 	cpuprofile := flag.String("cpuprofile", "", "cpuprofile output")

-	var flagJSON, flagDeps, flagTest *bool
-	if command == "help" || command == "list" || command == "info" {
-		flagJSON = flag.Bool("json", false, "print data in JSON format")
+	var flagJSON, flagDeps, flagTest bool
+	if command == "help" || command == "list" || command == "info" || command == "build" {
+		flag.BoolVar(&flagJSON, "json", false, "print data in JSON format")
 	}
 	if command == "help" || command == "list" {
-		flagDeps = flag.Bool("deps", false, "supply -deps flag to go list")
-		flagTest = flag.Bool("test", false, "supply -test flag to go list")
+		flag.BoolVar(&flagDeps, "deps", false, "supply -deps flag to go list")
+		flag.BoolVar(&flagTest, "test", false, "supply -test flag to go list")
 	}
 	var outpath string
 	if command == "help" || command == "build" || command == "build-library" || command == "test" {
@@ -1275,6 +1354,7 @@ func main() {
 		PanicStrategy:   *panicStrategy,
 		Scheduler:       *scheduler,
 		Serial:          *serial,
+		Work:            *work,
 		PrintIR:         *printIR,
 		DumpSSA:         *dumpSSA,
 		VerifyIR:        *verifyIR,
@@ -1289,6 +1369,7 @@ func main() {
 		Programmer:      *programmer,
 		OpenOCDCommands: ocdCommands,
 		LLVMFeatures:    *llvmFeatures,
+		PrintJSON:       flagJSON,
 	}
 	if *printCommands {
 		options.PrintCommands = printCommand
@@ -1317,11 +1398,6 @@ func main() {

 	switch command {
 	case "build":
-		if outpath == "" {
-			fmt.Fprintln(os.Stderr, "No output filename supplied (-o).")
-			usage(command)
-			os.Exit(1)
-		}
 		pkgName := "."
 		if flag.NArg() == 1 {
 			pkgName = filepath.ToSlash(flag.Arg(0))
@@ -1395,13 +1471,13 @@ func main() {
 			handleCompilerError(err)
 		}
 	case "run":
-		if flag.NArg() != 1 {
+		if flag.NArg() < 1 {
 			fmt.Fprintln(os.Stderr, "No package specified.")
 			usage(command)
 			os.Exit(1)
 		}
 		pkgName := filepath.ToSlash(flag.Arg(0))
-		err := Run(pkgName, options)
+		err := Run(pkgName, options, flag.Args()[1:])
 		handleCompilerError(err)
 	case "test":
 		var pkgNames []string
@@ -1411,8 +1487,8 @@ func main() {
 		if len(pkgNames) == 0 {
 			pkgNames = []string{"."}
 		}
-		if *testCompileOnlyFlag && len(pkgNames) > 1 {
-			fmt.Println("cannot use -c flag with multiple packages")
+		if outpath != "" && len(pkgNames) > 1 {
+			fmt.Println("cannot use -o flag with multiple packages")
 			os.Exit(1)
 		}

@@ -1497,7 +1573,7 @@ func main() {
 				os.Exit(1)
 				return
 			}
-			if spec.FlashMethod == "" && spec.FlashCommand == "" && spec.Emulator == nil {
+			if spec.FlashMethod == "" && spec.FlashCommand == "" && spec.Emulator == "" {
 				// This doesn't look like a regular target file, but rather like
 				// a parent target (such as targets/cortex-m.json).
 				continue
@@ -1530,7 +1606,7 @@ func main() {
 			fmt.Fprintln(os.Stderr, err)
 			os.Exit(1)
 		}
-		if *flagJSON {
+		if flagJSON {
 			json, _ := json.MarshalIndent(struct {
 				GOROOT     string   `json:"goroot"`
 				GOOS       string   `json:"goos"`
@@ -1569,13 +1645,13 @@ func main() {
 			os.Exit(1)
 		}
 		var extraArgs []string
-		if *flagJSON {
+		if flagJSON {
 			extraArgs = append(extraArgs, "-json")
 		}
-		if *flagDeps {
+		if flagDeps {
 			extraArgs = append(extraArgs, "-deps")
 		}
-		if *flagTest {
+		if flagTest {
 			extraArgs = append(extraArgs, "-test")
 		}
 		cmd, err := loader.List(config, extraArgs, flag.Args())
@@ -1612,8 +1688,8 @@ func main() {
 			goversion = s
 		}
 		version := goenv.Version
-		if strings.HasSuffix(goenv.Version, "-dev") && gitSha1 != "" {
-			version += "-" + gitSha1
+		if strings.HasSuffix(goenv.Version, "-dev") && goenv.GitSha1 != "" {
+			version += "-" + goenv.GitSha1
 		}
 		fmt.Printf("tinygo version %s %s/%s (using go version %s and LLVM version %s)\n", version, runtime.GOOS, runtime.GOARCH, goversion, llvm.Version)
 	case "env":
@@ -6,7 +6,6 @@ package main
 import (
 	"bufio"
 	"bytes"
-	"context"
 	"errors"
 	"flag"
 	"fmt"
@@ -14,7 +13,6 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"regexp"
 	"runtime"
 	"strings"
@@ -31,6 +29,13 @@ const TESTDATA = "testdata"

 var testTarget = flag.String("target", "", "override test target")

+var supportedLinuxArches = map[string]string{
+	"AMD64Linux": "linux/amd64",
+	"X86Linux":   "linux/386",
+	"ARMLinux":   "linux/arm/6",
+	"ARM64Linux": "linux/arm64",
+}
+
 var sema = make(chan struct{}, runtime.NumCPU())

 func TestBuild(t *testing.T) {
@@ -59,7 +64,6 @@ func TestBuild(t *testing.T) {
 		"stdlib.go",
 		"string.go",
 		"structs.go",
-		"testing.go",
 		"zeroalloc.go",
 	}
 	_, minor, err := goenv.GetGorootVersion(goenv.Get("GOROOT"))
@@ -69,6 +73,11 @@ func TestBuild(t *testing.T) {
 	if minor >= 17 {
 		tests = append(tests, "go1.17.go")
 	}
+	if minor >= 18 {
+		tests = append(tests, "testing_go118.go")
+	} else {
+		tests = append(tests, "testing.go")
+	}

 	if *testTarget != "" {
 		// This makes it possible to run one specific test (instead of all),
@@ -180,18 +189,14 @@ func TestBuild(t *testing.T) {
 	})

 	if runtime.GOOS == "linux" {
-		t.Run("X86Linux", func(t *testing.T) {
-			t.Parallel()
-			runPlatTests(optionsFromOSARCH("linux/386", sema), tests, t)
-		})
-		t.Run("ARMLinux", func(t *testing.T) {
-			t.Parallel()
-			runPlatTests(optionsFromOSARCH("linux/arm/6", sema), tests, t)
-		})
-		t.Run("ARM64Linux", func(t *testing.T) {
-			t.Parallel()
-			runPlatTests(optionsFromOSARCH("linux/arm64", sema), tests, t)
-		})
+		for name, osArch := range supportedLinuxArches {
+			options := optionsFromOSARCH(osArch, sema)
+			if options.GOARCH != runtime.GOARCH { // Native architecture already run above.
+				t.Run(name, func(t *testing.T) {
+					runPlatTests(options, tests, t)
+				})
+			}
+		}
 		t.Run("WebAssembly", func(t *testing.T) {
 			t.Parallel()
 			runPlatTests(optionsFromTarget("wasm", sema), tests, t)
@@ -218,7 +223,7 @@ func runPlatTests(options compileopts.Options, tests []string, t *testing.T) {
 			runTest(name, options, t, nil, nil)
 		})
 	}
-	if len(spec.Emulator) == 0 || spec.Emulator[0] != "simavr" {
+	if !strings.HasPrefix(spec.Emulator, "simavr ") {
 		t.Run("env.go", func(t *testing.T) {
 			t.Parallel()
 			runTest("env.go", options, t, []string{"first", "second"}, []string{"ENV1=VALUE1", "ENV2=VALUE2"})
@@ -252,8 +257,8 @@ func emuCheck(t *testing.T, options compileopts.Options) {
 	if err != nil {
 		t.Fatal("failed to load target spec:", err)
 	}
-	if len(spec.Emulator) != 0 {
-		_, err := exec.LookPath(spec.Emulator[0])
+	if spec.Emulator != "" {
+		_, err := exec.LookPath(strings.SplitN(spec.Emulator, " ", 2)[0])
 		if err != nil {
 			if errors.Is(err, exec.ErrNotFound) {
 				t.Skipf("emulator not installed: %q", spec.Emulator[0])
@@ -317,117 +322,27 @@ func runTestWithConfig(name string, t *testing.T, options compileopts.Options, c
 		t.Fatal("could not read expected output file:", err)
 	}

-	// Create a temporary directory for test output files.
-	tmpdir := t.TempDir()
-
-	// Determine whether we're on a system that supports environment variables
-	// and command line parameters (operating systems, WASI) or not (baremetal,
-	// WebAssembly in the browser). If we're on a system without an environment,
-	// we need to pass command line arguments and environment variables through
-	// global variables (built into the binary directly) instead of the
-	// conventional way.
-	spec, err := compileopts.LoadTarget(&options)
+	config, err := builder.NewConfig(&options)
 	if err != nil {
-		t.Fatal("failed to load target spec:", err)
-	}
-	needsEnvInVars := spec.GOOS == "js"
-	for _, tag := range spec.BuildTags {
-		if tag == "baremetal" {
-			needsEnvInVars = true
-		}
-	}
-	if needsEnvInVars {
-		runtimeGlobals := make(map[string]string)
-		if len(cmdArgs) != 0 {
-			runtimeGlobals["osArgs"] = strings.Join(cmdArgs, "\x00")
-		}
-		if len(environmentVars) != 0 {
-			runtimeGlobals["osEnv"] = strings.Join(environmentVars, "\x00")
-		}
-		if len(runtimeGlobals) != 0 {
-			// This sets the global variables like they would be set with
-			// `-ldflags="-X=runtime.osArgs=first\x00second`.
-			// The runtime package has two variables (osArgs and osEnv) that are
-			// both strings, from which the parameters and environment variables
-			// are read.
-			options.GlobalValues = map[string]map[string]string{
-				"runtime": runtimeGlobals,
-			}
-		}
+		t.Fatal(err)
 	}

 	// Build the test binary.
-	binary := filepath.Join(tmpdir, "test")
-	if spec.GOOS == "windows" {
-		binary += ".exe"
-	}
-	err = Build("./"+path, binary, &options)
+	stdout := &bytes.Buffer{}
+	err = buildAndRun("./"+path, config, stdout, cmdArgs, environmentVars, time.Minute, func(cmd *exec.Cmd, result builder.BuildResult) error {
+		return cmd.Run()
+	})
 	if err != nil {
 		printCompilerError(t.Log, err)
 		t.Fail()
 		return
 	}

-	// Reserve CPU time for the test to run.
-	// This attempts to ensure that the test is not CPU-starved.
-	options.Semaphore <- struct{}{}
-	defer func() { <-options.Semaphore }()
-
-	// Create the test command, taking care of emulators etc.
-	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-	defer cancel()
-	var cmd *exec.Cmd
-
-	// make sure any special vars in the emulator definition are rewritten
-	config := compileopts.Config{Target: spec}
-	emulator := config.Emulator()
-
-	if len(emulator) == 0 {
-		cmd = exec.CommandContext(ctx, binary)
-	} else {
-		args := append(emulator[1:], binary)
-		cmd = exec.CommandContext(ctx, emulator[0], args...)
-	}
-
-	if len(emulator) != 0 && 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 {
-		if !needsEnvInVars {
-			cmd.Args = append(cmd.Args, cmdArgs...) // works on qemu-aarch64 etc
-			cmd.Env = append(cmd.Env, environmentVars...)
-		}
-	}
-
-	// Run the test.
-	stdout := &bytes.Buffer{}
-	if len(emulator) != 0 && emulator[0] == "simavr" {
-		cmd.Stdout = os.Stderr
-		cmd.Stderr = stdout
-	} else {
-		cmd.Stdout = stdout
-		cmd.Stderr = os.Stderr
-	}
-	err = cmd.Start()
-	if err != nil {
-		t.Fatal("failed to start:", err)
-	}
-	err = cmd.Wait()
-
-	if cerr := ctx.Err(); cerr == context.DeadlineExceeded {
-		stdout.WriteString("--- test ran too long, terminating...\n")
-		err = cerr
-	}
-
 	// putchar() prints CRLF, convert it to LF.
 	actual := bytes.Replace(stdout.Bytes(), []byte{'\r', '\n'}, []byte{'\n'}, -1)
 	expected = bytes.Replace(expected, []byte{'\r', '\n'}, []byte{'\n'}, -1) // for Windows

-	if len(emulator) != 0 && emulator[0] == "simavr" {
+	if config.EmulatorName() == "simavr" {
 		// Strip simavr log formatting.
 		actual = bytes.Replace(actual, []byte{0x1b, '[', '3', '2', 'm'}, nil, -1)
 		actual = bytes.Replace(actual, []byte{0x1b, '[', '0', 'm'}, nil, -1)
@@ -475,12 +390,12 @@ func TestTest(t *testing.T) {
 	}
 	if !testing.Short() {
 		if runtime.GOOS == "linux" {
-			targs = append(targs,
-				// Linux
-				targ{"X86Linux", optionsFromOSARCH("linux/386", sema)},
-				targ{"ARMLinux", optionsFromOSARCH("linux/arm/6", sema)},
-				targ{"ARM64Linux", optionsFromOSARCH("linux/arm64", sema)},
-			)
+			for name, osArch := range supportedLinuxArches {
+				options := optionsFromOSARCH(osArch, sema)
+				if options.GOARCH != runtime.GOARCH { // Native architecture already run above.
+					targs = append(targs, targ{name, options})
+				}
+			}
 		}

 		targs = append(targs,
@@ -1,6 +1,7 @@
 // Hand created file. DO NOT DELETE.
 // Cortex-M System Control Block-related definitions.

+//go:build cortexm
 // +build cortexm

 package arm
@@ -142,18 +142,14 @@ func (mpu *MPU_Type) Enable(enable bool) {
 	if enable {
 		mpu.CTRL.Set(MPU_CTRL_PRIVDEFENA_Msk | MPU_CTRL_ENABLE_Msk)
 		SystemControl.SHCSR.SetBits(SCB_SHCSR_MEMFAULTENA_Msk)
-		arm.AsmFull(`
-      dsb 0xF
-      isb 0xF
-    `, nil)
+		arm.Asm("dsb 0xF")
+		arm.Asm("isb 0xF")
 		enableDcache(true)
 		enableIcache(true)
 	} else {
 		enableIcache(false)
 		enableDcache(false)
-		arm.AsmFull(`
-      dmb 0xF
-    `, nil)
+		arm.Asm("dmb 0xF")
 		SystemControl.SHCSR.ClearBits(SCB_SHCSR_MEMFAULTENA_Msk)
 		mpu.CTRL.ClearBits(MPU_CTRL_ENABLE_Msk)
 	}
@@ -188,31 +184,21 @@ func (mpu *MPU_Type) SetRASR(size RegionSize, access AccessPerms, ext Extension,
 func enableIcache(enable bool) {
 	if enable != SystemControl.CCR.HasBits(SCB_CCR_IC_Msk) {
 		if enable {
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
+			arm.Asm("isb 0xF")
 			SystemControl.ICIALLU.Set(0)
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
+			arm.Asm("isb 0xF")
 			SystemControl.CCR.SetBits(SCB_CCR_IC_Msk)
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
+			arm.Asm("isb 0xF")
 		} else {
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+		arm.Asm("dsb 0xF")
+		arm.Asm("isb 0xF")
 			SystemControl.CCR.ClearBits(SCB_CCR_IC_Msk)
 			SystemControl.ICIALLU.Set(0)
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+		arm.Asm("dsb 0xF")
+		arm.Asm("isb 0xF")
 		}
 	}
 }
@@ -227,9 +213,7 @@ func enableDcache(enable bool) {
 	if enable != SystemControl.CCR.HasBits(SCB_CCR_DC_Msk) {
 		if enable {
 			SystemControl.CSSELR.Set(0)
-			arm.AsmFull(`
-        dsb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
 			ccsidr := SystemControl.CCSIDR.Get()
 			sets := (ccsidr & SCB_CCSIDR_NUMSETS_Msk) >> SCB_CCSIDR_NUMSETS_Pos
 			for sets != 0 {
@@ -242,23 +226,15 @@ func enableDcache(enable bool) {
 				}
 				sets--
 			}
-			arm.AsmFull(`
-        dsb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
 			SystemControl.CCR.SetBits(SCB_CCR_DC_Msk)
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
+			arm.Asm("isb 0xF")
 		} else {
 			SystemControl.CSSELR.Set(0)
-			arm.AsmFull(`
-        dsb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
 			SystemControl.CCR.ClearBits(SCB_CCR_DC_Msk)
-			arm.AsmFull(`
-        dsb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
 			dcacheCcsidr.Set(SystemControl.CCSIDR.Get())
 			dcacheSets.Set((dcacheCcsidr.Get() & SCB_CCSIDR_NUMSETS_Msk) >> SCB_CCSIDR_NUMSETS_Pos)
 			for dcacheSets.Get() != 0 {
@@ -271,10 +247,8 @@ func enableDcache(enable bool) {
 				}
 				dcacheSets.Set(dcacheSets.Get() - 1)
 			}
-			arm.AsmFull(`
-        dsb 0xF
-        isb 0xF
-      `, nil)
+			arm.Asm("dsb 0xF")
+			arm.Asm("isb 0xF")
 		}
 	}
 }
@@ -0,0 +1,49 @@
+// Reads multiple rp2040 ADC channels concurrently. Including the internal temperature sensor
+
+package main
+
+import (
+	"fmt"
+	"machine"
+	"time"
+)
+
+type celsius float32
+
+func (c celsius) String() string {
+	return fmt.Sprintf("%4.1f℃", c)
+}
+
+// rp2040 ADC is 12 bits. Reading are shifted <<4 to fill the 16-bit range.
+var adcReading [3]uint16
+
+func readADC(a machine.ADC, w time.Duration, i int) {
+	for {
+		adcReading[i] = a.Get()
+		time.Sleep(w)
+	}
+}
+
+func main() {
+	machine.InitADC()
+	a0 := machine.ADC{machine.ADC0} // GPIO26 input
+	a1 := machine.ADC{machine.ADC1} // GPIO27 input
+	a2 := machine.ADC{machine.ADC2} // GPIO28 input
+	t := machine.ADC_TEMP_SENSOR    // Internal Temperature sensor
+	// Configure sets the GPIOs to PinAnalog mode
+	a0.Configure(machine.ADCConfig{})
+	a1.Configure(machine.ADCConfig{})
+	a2.Configure(machine.ADCConfig{})
+	// Configure powers on the temperature sensor
+	t.Configure(machine.ADCConfig{})
+
+	// Safe to read concurrently
+	go readADC(a0, 10*time.Millisecond, 0)
+	go readADC(a1, 17*time.Millisecond, 1)
+	go readADC(a2, 29*time.Millisecond, 2)
+
+	for {
+		fmt.Printf("ADC0: %5d ADC1: %5d ADC2: %5d Temp: %v\n\r", adcReading[0], adcReading[1], adcReading[2], celsius(float32(t.ReadTemperature())/1000))
+		time.Sleep(1000 * time.Millisecond)
+	}
+}
@@ -1,3 +1,4 @@
+//go:build feather_m4_can
 // +build feather_m4_can

 package main
@@ -1,3 +1,4 @@
+//go:build feather_m4_can
 // +build feather_m4_can

 package main
@@ -1,3 +1,4 @@
+//go:build circuitplay_express
 // +build circuitplay_express

 package main
@@ -1,3 +1,4 @@
+//go:build pyportal
 // +build pyportal

 package main
@@ -1,3 +1,4 @@
+//go:build circuitplay_express
 // +build circuitplay_express

 package main
@@ -1,3 +1,4 @@
+//go:build pca10040
 // +build pca10040

 package main
@@ -1,3 +1,4 @@
+//go:build stm32
 // +build stm32

 package main
@@ -1,3 +1,4 @@
+//go:build wioterminal
 // +build wioterminal

 package main
@@ -1,3 +1,4 @@
+//go:build arduino_mega1280
 // +build arduino_mega1280

 package main
@@ -1,3 +1,4 @@
+//go:build arduino
 // +build arduino

 package main
@@ -1,3 +1,4 @@
+//go:build bluepill
 // +build bluepill

 package main
@@ -1,3 +1,4 @@
+//go:build feather_m4
 // +build feather_m4

 package main
@@ -1,3 +1,4 @@
+//go:build itsybitsy_m0
 // +build itsybitsy_m0

 package main
@@ -1,3 +1,4 @@
+//go:build itsybitsy_m4
 // +build itsybitsy_m4

 package main
@@ -1,3 +1,4 @@
+//go:build stm32f7
 // +build stm32f7

 package main
@@ -1,3 +1,4 @@
+//go:build stm32l0
 // +build stm32l0

 package main
@@ -1,3 +1,4 @@
+//go:build stm32l4
 // +build stm32l4

 package main
@@ -1,3 +1,4 @@
+//go:build stm32l5
 // +build stm32l5

 package main
@@ -1,3 +1,4 @@
+//go:build pico
 // +build pico

 package main
@@ -1,3 +1,4 @@
+//go:build stm32f4disco
 // +build stm32f4disco

 package main
@@ -0,0 +1,133 @@
+// Package fuzz is a shim to allow compilation against Go 1.18.
+// It only defines a single type to work with testing/internal/testdeps,
+// and hide all the other new dependencies from this package.
+package fuzz
+
+import (
+	"context"
+	"errors"
+	"io"
+	"reflect"
+	"time"
+)
+
+// CorpusEntry represents an individual input for fuzzing.
+//
+// We must use an equivalent type in the testing and testing/internal/testdeps
+// packages, but testing can't import this package directly, and we don't want
+// to export this type from testing. Instead, we use the same struct type and
+// use a type alias (not a defined type) for convenience.
+type CorpusEntry = struct {
+	Parent string
+
+	// Path is the path of the corpus file, if the entry was loaded from disk.
+	// For other entries, including seed values provided by f.Add, Path is the
+	// name of the test, e.g. seed#0 or its hash.
+	Path string
+
+	// Data is the raw input data. Data should only be populated for seed
+	// values. For on-disk corpus files, Data will be nil, as it will be loaded
+	// from disk using Path.
+	Data []byte
+
+	// Values is the unmarshaled values from a corpus file.
+	Values []any
+
+	Generation int
+
+	// IsSeed indicates whether this entry is part of the seed corpus.
+	IsSeed bool
+}
+
+// CoordinateFuzzingOpts is a set of arguments for CoordinateFuzzing.
+// The zero value is valid for each field unless specified otherwise.
+type CoordinateFuzzingOpts struct {
+	// Log is a writer for logging progress messages and warnings.
+	// If nil, io.Discard will be used instead.
+	Log io.Writer
+
+	// Timeout is the amount of wall clock time to spend fuzzing after the corpus
+	// has loaded. If zero, there will be no time limit.
+	Timeout time.Duration
+
+	// Limit is the number of random values to generate and test. If zero,
+	// there will be no limit on the number of generated values.
+	Limit int64
+
+	// MinimizeTimeout is the amount of wall clock time to spend minimizing
+	// after discovering a crasher. If zero, there will be no time limit. If
+	// MinimizeTimeout and MinimizeLimit are both zero, then minimization will
+	// be disabled.
+	MinimizeTimeout time.Duration
+
+	// MinimizeLimit is the maximum number of calls to the fuzz function to be
+	// made while minimizing after finding a crash. If zero, there will be no
+	// limit. Calls to the fuzz function made when minimizing also count toward
+	// Limit. If MinimizeTimeout and MinimizeLimit are both zero, then
+	// minimization will be disabled.
+	MinimizeLimit int64
+
+	// parallel is the number of worker processes to run in parallel. If zero,
+	// CoordinateFuzzing will run GOMAXPROCS workers.
+	Parallel int
+
+	// Seed is a list of seed values added by the fuzz target with testing.F.Add
+	// and in testdata.
+	Seed []CorpusEntry
+
+	// Types is the list of types which make up a corpus entry.
+	// Types must be set and must match values in Seed.
+	Types []reflect.Type
+
+	// CorpusDir is a directory where files containing values that crash the
+	// code being tested may be written. CorpusDir must be set.
+	CorpusDir string
+
+	// CacheDir is a directory containing additional "interesting" values.
+	// The fuzzer may derive new values from these, and may write new values here.
+	CacheDir string
+}
+
+// CoordinateFuzzing creates several worker processes and communicates with
+// them to test random inputs that could trigger crashes and expose bugs.
+// The worker processes run the same binary in the same directory with the
+// same environment variables as the coordinator process. Workers also run
+// with the same arguments as the coordinator, except with the -test.fuzzworker
+// flag prepended to the argument list.
+//
+// If a crash occurs, the function will return an error containing information
+// about the crash, which can be reported to the user.
+func CoordinateFuzzing(ctx context.Context, opts CoordinateFuzzingOpts) (err error) {
+	return errors.New("not implemented")
+}
+
+// ReadCorpus reads the corpus from the provided dir. The returned corpus
+// entries are guaranteed to match the given types. Any malformed files will
+// be saved in a MalformedCorpusError and returned, along with the most recent
+// error.
+func ReadCorpus(dir string, types []reflect.Type) ([]CorpusEntry, error) {
+	return nil, errors.New("not implemented")
+}
+
+// CheckCorpus verifies that the types in vals match the expected types
+// provided.
+func CheckCorpus(vals []any, types []reflect.Type) error {
+	return errors.New("not implemented")
+}
+
+func ResetCoverage() {}
+func SnapshotCoverage() {}
+
+// RunFuzzWorker is called in a worker process to communicate with the
+// coordinator process in order to fuzz random inputs. RunFuzzWorker loops
+// until the coordinator tells it to stop.
+//
+// fn is a wrapper on the fuzz function. It may return an error to indicate
+// a given input "crashed". The coordinator will also record a crasher if
+// the function times out or terminates the process.
+//
+// RunFuzzWorker returns an error if it could not communicate with the
+// coordinator process.
+func RunFuzzWorker(ctx context.Context, fn func(CorpusEntry) error) error {
+	return errors.New("not implemented")
+}
@@ -1,3 +1,4 @@
+//go:build arduino
 // +build arduino

 package machine
@@ -1,3 +1,4 @@
+//go:build arduino_mega1280
 // +build arduino_mega1280

 package machine
@@ -1,3 +1,4 @@
+//go:build arduino_mega2560
 // +build arduino_mega2560

 package machine
@@ -1,3 +1,4 @@
+//go:build arduino_mkr1000
 // +build arduino_mkr1000

 // This contains the pin mappings for the Arduino MKR1000 board.
@@ -1,3 +1,4 @@
+//go:build arduino_mkrwifi1010
 // +build arduino_mkrwifi1010

 // This contains the pin mappings for the Arduino MKR WiFi 1010 board.
@@ -1,3 +1,4 @@
+//go:build arduino_nano
 // +build arduino_nano

 package machine
@@ -1,3 +1,4 @@
+//go:build arduino_nano33
 // +build arduino_nano33

 // This contains the pin mappings for the Arduino Nano33 IoT board.
@@ -1,3 +1,4 @@
+//go:build sam && atsamd21 && arduino_zero
 // +build sam,atsamd21,arduino_zero

 package machine
@@ -1,3 +1,4 @@
+//go:build (avr && atmega328p) || arduino || arduino_nano
 // +build avr,atmega328p arduino arduino_nano

 package machine
--- a/Show More
+++ b/Show More