Prepare for 0.15.0 release

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

.circleci/config.yml

@@ -37,28 +37,47 @@ commands:
             sudo tar -C /usr/local -xf node-v10.15.1-linux-x64.tar.xz
             sudo ln -s /usr/local/node-v10.15.1-linux-x64/bin/node /usr/bin/node
             rm node-v10.15.1-linux-x64.tar.xz
+  install-chrome:
+    steps:
+      - run:
+          name: "Install Chrome"
+          command: |
+            wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
+            sudo apt install ./google-chrome-stable_current_amd64.deb
+  install-xtensa-toolchain:
+    parameters:
+      variant:
+        type: string
+    steps:
+      - run:
+          name: "Install Xtensa toolchain"
+          command: |
+            curl -L https://github.com/espressif/crosstool-NG/releases/download/esp-2020r2/xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz -o xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo tar -C /usr/local -xf xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
+            sudo ln -s /usr/local/xtensa-esp32-elf/bin/xtensa-esp32-elf-ld /usr/local/bin/xtensa-esp32-elf-ld
+            rm xtensa-esp32-elf-gcc8_2_0-esp-2020r2-<<parameters.variant>>.tar.gz
   llvm-source-linux:
     steps:
       - restore_cache:
           keys:
-            - llvm-source-10-v0
+            - llvm-source-10-v1
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-10-v0
+          key: llvm-source-10-v1
           paths:
             - llvm-project
   build-wasi-libc:
     steps:
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-v2
+            - wasi-libc-sysroot-v3
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-v2
+          key: wasi-libc-sysroot-v3
           paths:
             - lib/wasi-libc/sysroot
   test-linux:
@@ -71,6 +90,7 @@ commands:
       - apt-dependencies:
           llvm: "<<parameters.llvm>>"
       - install-node
+      - install-chrome
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -79,20 +99,21 @@ commands:
       - run: go install -tags=llvm<<parameters.llvm>> .
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-systemclang-v1
+            - wasi-libc-sysroot-systemclang-v2
       - run: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-systemclang-v1
+          key: wasi-libc-sysroot-systemclang-v2
           paths:
             - lib/wasi-libc/sysroot
       - run: go test -v -tags=llvm<<parameters.llvm>> ./cgo ./compileopts ./interp ./transform .
       - run: make gen-device -j4
-      - run: make smoketest
+      - run: make smoketest XTENSA=0
+      - run: make tinygo-test
+      - run: make wasmtest
       - save_cache:
           key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
           paths:
             - ~/.cache/go-build
-            - ~/.cache/tinygo
             - /go/pkg/mod
       - run: make fmt-check
   assert-test-linux:
@@ -113,6 +134,8 @@ commands:
                 gcc-avr \
                 avr-libc
       - install-node
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -120,7 +143,7 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-10-linux-v0-assert
+            - llvm-build-10-linux-v1-assert
       - run:
           name: "Build LLVM"
           command: |
@@ -138,7 +161,7 @@ commands:
               make ASSERT=1 llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-linux-v0-assert
+          key: llvm-build-10-linux-v1-assert
           paths:
             llvm-build
       - run: make ASSERT=1
@@ -150,7 +173,6 @@ commands:
           key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
           paths:
             - ~/.cache/go-build
-            - ~/.cache/tinygo
             - /go/pkg/mod
       - run: make gen-device -j4
       - run: make smoketest TINYGO=build/tinygo
@@ -172,6 +194,8 @@ commands:
                 gcc-avr \
                 avr-libc
       - install-node
+      - install-xtensa-toolchain:
+          variant: "linux-amd64"
       - restore_cache:
           keys:
             - go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
@@ -179,7 +203,7 @@ commands:
       - llvm-source-linux
       - restore_cache:
           keys:
-            - llvm-build-10-linux-v0
+            - llvm-build-10-linux-v1
       - run:
           name: "Build LLVM"
           command: |
@@ -197,25 +221,32 @@ commands:
               make llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-linux-v0
+          key: llvm-build-10-linux-v1
           paths:
             llvm-build
       - build-wasi-libc
       - run:
           name: "Test TinyGo"
           command: make test
+      - run:
+          name: "Install fpm"
+          command: |
+            sudo apt-get install ruby ruby-dev
+            sudo gem install --no-document fpm
       - run:
           name: "Build TinyGo release"
           command: |
-            make release -j3
+            make release deb -j3
             cp -p build/release.tar.gz /tmp/tinygo.linux-amd64.tar.gz
+            cp -p build/release.deb    /tmp/tinygo_amd64.deb
       - store_artifacts:
           path: /tmp/tinygo.linux-amd64.tar.gz
+      - store_artifacts:
+          path: /tmp/tinygo_amd64.deb
       - save_cache:
           key: go-cache-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
           paths:
             - ~/.cache/go-build
-            - ~/.cache/tinygo
             - /go/pkg/mod
       - run:
           name: "Extract release tarball"
@@ -236,23 +267,25 @@ commands:
             sudo tar -C /usr/local -xzf go1.14.darwin-amd64.tar.gz
             ln -s /usr/local/go/bin/go /usr/local/bin/go
             HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu
+      - install-xtensa-toolchain:
+          variant: "macos"
       - restore_cache:
           keys:
             - go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_PREVIOUS_BUILD_NUM }}
             - go-cache-macos-v2-{{ checksum "go.mod" }}
       - restore_cache:
           keys:
-            - llvm-source-10-macos-v0
+            - llvm-source-10-macos-v1
       - run:
           name: "Fetch LLVM source"
           command: make llvm-source
       - save_cache:
-          key: llvm-source-10-macos-v0
+          key: llvm-source-10-macos-v1
           paths:
             - llvm-project
       - restore_cache:
           keys:
-            - llvm-build-10-macos-v0
+            - llvm-build-10-macos-v1
       - run:
           name: "Build LLVM"
           command: |
@@ -264,17 +297,17 @@ commands:
               make llvm-build
             fi
       - save_cache:
-          key: llvm-build-10-macos-v0
+          key: llvm-build-10-macos-v1
           paths:
             llvm-build
       - restore_cache:
           keys:
-            - wasi-libc-sysroot-macos-v1
+            - wasi-libc-sysroot-macos-v2
       - run:
           name: "Build wasi-libc"
           command: make wasi-libc
       - save_cache:
-          key: wasi-libc-sysroot-macos-v1
+          key: wasi-libc-sysroot-macos-v2
           paths:
             - lib/wasi-libc/sysroot
       - run:
@@ -294,19 +327,66 @@ commands:
             tar -C /usr/local/opt -xf /tmp/tinygo.darwin-amd64.tar.gz
             ln -s /usr/local/opt/tinygo/bin/tinygo /usr/local/bin/tinygo
             tinygo version
-      - run:
-          name: "Download SiFive GNU toolchain"
-          command: |
-            curl -O https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.2.0-2019.05.3-x86_64-apple-darwin.tar.gz
-            sudo tar -C /usr/local --strip-components=1 -xf riscv64-unknown-elf-gcc-8.2.0-2019.05.3-x86_64-apple-darwin.tar.gz
       - run: make smoketest AVR=0
       - save_cache:
           key: go-cache-macos-v2-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}
           paths:
             - ~/.cache/go-build
-            - ~/.cache/tinygo
             - /go/pkg/mod
-
+  arch-release:
+    steps:
+      - run:
+          name: Install dependencies
+          command: pacman -Sy --noconfirm openssh git pacman-contrib binutils
+      - run:
+          name: Create TinyGo user
+          command: useradd -m tinygo
+      - run:
+          name: Start SSH Agent
+          user: tinygo
+          command: eval $(ssh-agent -s)
+      - run:
+          name: Add ARCH_RELEASE_SSH_PRIVATE_KEY identity
+          user: tinygo
+          command: echo "${ARCH_RELEASE_SSH_PRIVATE_KEY}" | tr -d '\r' | ssh-add -
+      - run:
+          name: Create SSH directory
+          user: tinygo
+          command: mkdir -p ~/.ssh && chmod 700 ~/.ssh
+      - run:
+          name: Add aur.archlinux.org to known hosts
+          user: tinygo
+          command: ssh-keyscan aur.archlinux.org >> ~/.ssh/known_hosts
+      - run:
+          name: Clone tinygo-bin repo
+          user: tinygo
+          command: git clone ssh://aur@aur.archlinux.org/tinygo-bin.git ~/tinygo-bin
+      - run:
+          name: Update package version
+          user: tinygo
+          command: sed -i -E "s/(pkgver=)(.*)$/\1${CIRCLE_TAG}/" ~/tinygo-bin/PKGBUILD
+      - run:
+          name: Update file checksums
+          user: tinygo
+          command: cd ~/tinygo-bin && updpkgsums
+      - run:
+          name: Update .SRCINFO
+          user: tinygo
+          command: cd ~/tinygo-bin && makepkg --printsrcinfo > .SRCINFO
+      # Commit the update
+      - run:
+          name: Set git commit config
+          user: tinygo
+          command: |
+            git config --global user.email "tinygo-bot@tinygo.org" &&
+            git config --global user.name "TinyGo Release Bot"
+      - run:
+          name: Commit and push changes
+          user: tinygo
+          command: |
+            cd ~/tinygo-bin &&
+            git commit -a -m "Update tinygo-bin to v${CIRCLE_TAG}" &&
+            git push origin master
 
 jobs:
   test-llvm9-go111:
@@ -333,6 +413,12 @@ jobs:
     steps:
       - test-linux:
           llvm: "10"
+  test-llvm10-go115:
+    docker:
+      - image: circleci/golang:1.15-buster
+    steps:
+      - test-linux:
+          llvm: "10"        
   assert-test-linux:
     docker:
       - image: circleci/golang:1.14-stretch
@@ -348,6 +434,11 @@ jobs:
       xcode: "10.1.0"
     steps:
       - build-macos
+  arch-release:
+    docker:
+      - image: archlinux:latest
+    steps:
+      - arch-release
 
 
 
@@ -359,6 +450,16 @@ workflows:
       - test-llvm10-go112
       - test-llvm10-go113
       - test-llvm10-go114
+      - test-llvm10-go115
       - build-linux
       - build-macos
       - assert-test-linux
+  release:
+    jobs:
+      - arch-release:
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              # Runs on every semver release
+              only: /v[0-9]+(\.[0-9]+)*(-.*)*/

.gitignore

@@ -3,14 +3,19 @@ docs/_build
 src/device/avr/*.go
 src/device/avr/*.ld
 src/device/avr/*.s
+src/device/esp/*.go
 src/device/nrf/*.go
 src/device/nrf/*.s
+src/device/nxp/*.go
+src/device/nxp/*.s
 src/device/sam/*.go
 src/device/sam/*.s
 src/device/sifive/*.go
 src/device/sifive/*.s
 src/device/stm32/*.go
 src/device/stm32/*.s
+src/device/kendryte/*.go
+src/device/kendryte/*.s
 vendor
 llvm-build
 llvm-project

.gitmodules

@@ -9,7 +9,7 @@
 	url = https://github.com/avr-rust/avr-mcu.git
 [submodule "lib/cmsis-svd"]
 	path = lib/cmsis-svd
-	url = https://github.com/posborne/cmsis-svd
+	url = https://github.com/tinygo-org/cmsis-svd
 [submodule "lib/compiler-rt"]
 	path = lib/compiler-rt
 	url = https://github.com/llvm-mirror/compiler-rt.git

BUILDING.md

@@ -10,6 +10,14 @@ This guide describes how to statically link TinyGo against LLVM, libclang and
 lld so that the binary can be easily moved between systems. It also shows how to
 build a release tarball that includes this binary and all necessary extra files.
 
+**Note**: this documentation describes how to build a statically linked release
+tarball. If you want to develop TinyGo, you will probably want to follow a
+different guide:
+
+  * [Linux](https://tinygo.org/getting-started/linux/#source-install)
+  * [macOS](https://tinygo.org/getting-started/macos/#source-install)
+  * [Windows](https://tinygo.org/getting-started/windows/#source-install)
+
 ## Dependencies
 
 LLVM, Clang and LLD are quite light on dependencies, requiring only standard
@@ -84,6 +92,10 @@ Now that we have a working static build, it's time to make a release tarball:
 
     make release
 
+If you did not clone the repository with the `--recursive` option, you will get errors until you initialize the project submodules:
+
+    git submodule update --init
+
 The release tarball is stored in build/release.tar.gz, and can be extracted with
 the following command (for example in ~/lib):
 

CHANGELOG.md

@@ -1,3 +1,172 @@
+0.15.0
+---
+
+* **command-line**
+  - add cached GOROOT to info subcommand
+  - embed git-hash in tinygo-dev executable
+  - implement tinygo targets to list usable targets
+  - use simpler file copy instead of file renaming to avoid issues on nrf52840 UF2 bootloaders
+  - use ToSlash() to specify program path
+  - support flashing esp32/esp8266 directly from tinygo
+  - when flashing call PortReset only on other than openocd
+* **compiler**
+  - `compileopts`: add support for custom binary formats
+  - `compiler`: improve display of goroutine wrappers
+  - `interp`: don't panic in the Store method
+  - `interp`: replace some panics with error messages
+  - `interp`: show error line in first line of the traceback
+  - `loader`: be more robust when creating the cached GOROOT
+  - `loader`: rewrite/refactor much of the code to use go list directly
+  - `loader`: use ioutil.TempDir to create a temporary directory
+  - `stacksize`: deal with DW_CFA_advance_loc1
+* **standard library**
+  - `runtime`: use waitForEvents when appropriate
+* **wasm**
+  - `wasm`: Remove --no-threads from wasm-ld calls.
+  - `wasm`: update wasi-libc dependency
+* **targets**
+  - `arduino-mega2560`: fix flashing on Windows
+  - `arm`: automatically determine stack sizes
+  - `arm64`: make dynamic loader structs and constants private
+  - `avr`: configure emulator in board files
+  - `cortexm`: fix stack size calculation with interrupts
+  - `flash`: add openocd settings to atsamd21 / atsamd51
+  - `flash`: add openocd settings to nrf5
+  - `microbit`: reelboard: flash using OpenOCD when needed
+  - `nintendoswitch`: Add dynamic loader for runtime loading PIE sections
+  - `nintendoswitch`: fix import cycle on dynamic_arm64.go
+  - `nintendoswitch`: Fix invalid memory read / write in print calls
+  - `nintendoswitch`: simplified assembly code
+  - `nintendoswitch`: support outputting .nro files directly
+* **boards**
+  - `arduino-zero`: Adding support for the Arduino Zero (#1365)
+  - `atsamd2x`: fix BAUD value
+  - `atsamd5x`: fix BAUD value
+  - `bluepill`: Enable stm32's USART2 for the board and map it to UART1 tinygo's device
+  - `device/atsamd51x`: add all remaining bitfield values for PCHCTRLm Mapping
+  - `esp32`: add libgcc ROM functions to linker script
+  - `esp32`: add SPI support
+  - `esp32`: add support for basic GPIO
+  - `esp32`: add support for the Espressif ESP32 chip
+  - `esp32`: configure the I/O matrix for GPIO pins
+  - `esp32`: export machine.PortMask* for bitbanging implementations
+  - `esp8266`: add support for this chip
+  - `machine/atsamd51x,runtime/atsamd51x`: fixes needed for full support for all PWM pins. Also adds some useful constants to clarify peripheral clock usage
+  - `machine/itsybitsy-nrf52840`: add support for Adafruit Itsybitsy nrf52840 (#1243)
+  - `machine/stm32f4`: refactor common code and add new build tag stm32f4 (#1332)
+  - `nrf`: add SoftDevice support for the Circuit Playground Bluefruit
+  - `nrf`: call sd_app_evt_wait when the SoftDevice is enabled
+  - `nrf52840`: add build tags for SoftDevice support
+  - `nrf52840`: use higher priority for USB-CDC code
+  - `runtime/atsamd51x`: use PCHCTRL_GCLK_SERCOMX_SLOW for setting clocks on all SERCOM ports
+  - `stm32f405`: add basic UART handler
+  - `stm32f405`: add STM32F405 machine/runtime, and new board/target feather-stm32f405
+* **build**
+  - `all`: run test binaries in the correct directory
+  - `build`: Fix arch release job
+  - `ci`: run `tinygo test` for known-working packages
+  - `ci`: set git-fetch-depth to 1
+  - `docker`: fix the problem with the wasm build (#1357)
+  - `Makefile`: check whether submodules have been downloaded in some common cases
+* **docs**
+  - add ESP32, ESP8266, and Adafruit Feather STM32F405 to list of supported boards
+
+0.14.1
+---
+* **command-line**
+  - support for Go 1.15
+* **compiler**
+  - loader:  work around Windows symlink limitation
+
+0.14.0
+---
+* **command-line**
+  - fix `getDefaultPort()` on non-English Windows locales
+  - compileopts: improve error reporting of unsupported flags
+  - fix test subcommand
+  - use auto-retry to locate MSD for UF2 and HEX flashing
+  - fix touchSerialPortAt1200bps on Windows
+  - support package names with backslashes on Windows
+* **compiler**
+  - fix a few crashes due to named types
+  - add support for atomic operations
+  - move the channel blocked list onto the stack
+  - fix -gc=none
+  - fix named string to `[]byte` slice conversion
+  - implement func value and builtin defers
+  - add proper parameter names to runtime.initAll, to fix a panic
+  - builder: fix picolibc include path
+  - builder: use newer version of gohex
+  - builder: try to determine stack size information at compile time
+  - builder: remove -opt=0
+  - interp: fix sync/atomic.Value load/store methods
+  - loader: add Go module support
+  - transform: fix debug information in func lowering pass
+  - transform: do not special-case zero or one implementations of a method call
+  - transform: introduce check for method calls on nil interfaces
+  - transform: gc: track 0-index GEPs to fix miscompilation
+* **cgo**
+  - Add LDFlags support
+* **standard library**
+  - extend stdlib to allow import of more packages
+  - replace master/slave terminology with appropriate alternatives (MOSI->SDO
+    etc)
+  - `internal/bytealg`: reimplement bytealg in pure Go
+  - `internal/task`: fix nil panic in (*internal/task.Stack).Pop
+  - `os`: add Args and stub it with mock data
+  - `os`: implement virtual filesystem support
+  - `reflect`: add Cap and Len support for map and chan
+  - `runtime`: fix return address in scheduler on RISC-V
+  - `runtime`: avoid recursion in printuint64 function
+  - `runtime`: replace ReadRegister with AsmFull inline assembly
+  - `runtime`: fix compilation errors when using gc.extalloc
+  - `runtime`: add cap and len support for chans
+  - `runtime`: refactor time handling (improving accuracy)
+  - `runtime`: make channels work in interrupts
+  - `runtime/interrupt`: add cross-chip disable/restore interrupt support
+  - `sync`: implement `sync.Cond`
+  - `sync`: add WaitGroup
+* **targets**
+  - `arm`: allow nesting in DisableInterrupts and EnableInterrupts
+  - `arm`: make FPU configuraton consistent
+  - `arm`: do not mask fault handlers in critical sections
+  - `atmega2560`: fix pin mapping for pins D2, D5 and the L port
+  - `atsamd`: return an error when an incorrect PWM pin is used
+  - `atsamd`: add support for pin change interrupts
+  - `atsamd`: add DAC support
+  - `atsamd21`: add more ADC pins
+  - `atsamd51`: fix ROM / RAM size on atsamd51j20
+  - `atsamd51`: add more pins
+  - `atsamd51`: add more ADC pins
+  - `atsamd51`: add pin change interrupt settings
+  - `atsamd51`: extend pinPadMapping
+  - `arduino-nano33`: use (U)SB flag to ensure that device can be found when
+     not on default port
+  - `arduino-nano33`: remove (d)ebug flag to reduce console noise when flashing
+  - `avr`: use standard pin numbering
+  - `avr`: unify GPIO pin/port code
+  - `avr`: add support for PinInputPullup
+  - `avr`: work around codegen bug in LLVM 10
+  - `avr`: fix target triple
+  - `fe310`: remove extra println left in by mistake
+  - `feather-nrf52840`: add support for the Feather nRF52840
+  - `maixbit`: add board definition and dummy runtime
+  - `nintendoswitch`: Add experimental Nintendo Switch support without CRT
+  - `nrf`: expose the RAM base address
+  - `nrf`: add support for pin change interrupts
+  - `nrf`: add microbit-s110v8 target
+  - `nrf`: fix bug in SPI.Tx
+  - `nrf`: support debugging the PCA10056
+  - `pygamer`: add Adafruit PyGamer suport
+  - `riscv`: fix interrupt configuration bug
+  - `riscv`: disable linker relaxations during gp init
+  - `stm32f4disco`: add new target with ST-Link v2.1 debugger
+  - `teensy36`: add Teensy 3.6 support
+  - `wasm`: fix event handling
+  - `wasm`: add --no-demangle linker option
+  - `wioterminal`: add support for the Seeed Wio Terminal
+  - `xiao`: add support for the Seeed XIAO
+
 0.13.1
 ---
 * **standard library**

CONTRIBUTING.md

@@ -32,7 +32,7 @@ Microcontrollers have lots of peripherals (I2C, SPI, ADC, etc.) and many don't h
 
 ## How to use our Github repository
 
-The `master` branch of this repo will always have the latest released version of TinyGo. All of the active development work for the next release will take place in the `dev` branch. TinyGo will use semantic versioning and will create a tag/release for each release.
+The `release` branch of this repo will always have the latest released version of TinyGo. All of the active development work for the next release will take place in the `dev` branch. TinyGo will use semantic versioning and will create a tag/release for each release.
 
 Here is how to contribute back some code or documentation:
 

CONTRIBUTORS

@@ -15,4 +15,4 @@ Ayke van Laethem <aykevanlaethem@gmail.com>
 Daniel Esteban <conejo@conejo.me>
 Loon, LLC.
 Ron Evans <ron@hybridgroup.com>
-Jaden Weiss <jaden@jadendw.dev>
+Nia Weiss <niaow1234@gmail.com>

Dockerfile

@@ -4,7 +4,7 @@ FROM golang:1.14 AS tinygo-base
 RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
     echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y llvm-10-dev libclang-10-dev git
+    apt-get install -y llvm-10-dev libclang-10-dev lld-10 git
 
 COPY . /tinygo
 
@@ -27,10 +27,10 @@ COPY --from=tinygo-base /go/bin/tinygo /go/bin/tinygo
 COPY --from=tinygo-base /tinygo/src /tinygo/src
 COPY --from=tinygo-base /tinygo/targets /tinygo/targets
 
-RUN wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key| apt-key add - && \
+RUN cd /tinygo/ && \
-    echo "deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main" >> /etc/apt/sources.list && \
     apt-get update && \
-    apt-get install -y libllvm10 lld-10
+    apt-get install -y make clang-10 libllvm10 lld-10 && \
+    make wasi-libc
 
 # tinygo-avr stage installs the needed dependencies to compile TinyGo programs for AVR microcontrollers.
 FROM tinygo-base AS tinygo-avr

Makefile

@@ -51,7 +51,7 @@ else
     LLVM_OPTION += '-DLLVM_ENABLE_ASSERTIONS=OFF'
 endif
 
-.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-avr
+.PHONY: all tinygo test $(LLVM_BUILDDIR) llvm-source clean fmt gen-device gen-device-nrf gen-device-nxp gen-device-avr
 
 LLVM_COMPONENTS = all-targets analysis asmparser asmprinter bitreader bitwriter codegen core coroutines coverage debuginfodwarf executionengine frontendopenmp instrumentation interpreter ipo irreader linker lto mc mcjit objcarcopts option profiledata scalaropts support target
 
@@ -118,9 +118,10 @@ fmt-check:
 	@unformatted=$$(gofmt -l $(FMT_PATHS)); [ -z "$$unformatted" ] && exit 0; echo "Unformatted:"; for fn in $$unformatted; do echo "  $$fn"; done; exit 1
 
 
-gen-device: gen-device-avr gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32
+gen-device: gen-device-avr gen-device-esp gen-device-nrf gen-device-sam gen-device-sifive gen-device-stm32 gen-device-kendryte gen-device-nxp
 
 gen-device-avr:
+	@if [ ! -e lib/avr/README.md ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	$(GO) build -o ./build/gen-device-avr ./tools/gen-device-avr/
 	./build/gen-device-avr lib/avr/packs/atmega src/device/avr/
 	./build/gen-device-avr lib/avr/packs/tiny src/device/avr/
@@ -129,10 +130,18 @@ gen-device-avr:
 build/gen-device-svd: ./tools/gen-device-svd/*.go
 	$(GO) build -o $@ ./tools/gen-device-svd/
 
+gen-device-esp: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Espressif-Community -interrupts=software lib/cmsis-svd/data/Espressif-Community/ src/device/esp/
+	GO111MODULE=off $(GO) fmt ./src/device/esp
+
 gen-device-nrf: build/gen-device-svd
 	./build/gen-device-svd -source=https://github.com/NordicSemiconductor/nrfx/tree/master/mdk lib/nrfx/mdk/ src/device/nrf/
 	GO111MODULE=off $(GO) fmt ./src/device/nrf
 
+gen-device-nxp: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/NXP lib/cmsis-svd/data/NXP/ src/device/nxp/
+	GO111MODULE=off $(GO) fmt ./src/device/nxp
+
 gen-device-sam: build/gen-device-svd
 	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Atmel lib/cmsis-svd/data/Atmel/ src/device/sam/
 	GO111MODULE=off $(GO) fmt ./src/device/sam
@@ -141,6 +150,10 @@ gen-device-sifive: build/gen-device-svd
 	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/SiFive-Community -interrupts=software lib/cmsis-svd/data/SiFive-Community/ src/device/sifive/
 	GO111MODULE=off $(GO) fmt ./src/device/sifive
 
+gen-device-kendryte: build/gen-device-svd
+	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/Kendryte-Community -interrupts=software lib/cmsis-svd/data/Kendryte-Community/ src/device/kendryte/
+	GO111MODULE=off $(GO) fmt ./src/device/kendryte
+
 gen-device-stm32: build/gen-device-svd
 	./build/gen-device-svd -source=https://github.com/posborne/cmsis-svd/tree/master/data/STMicro lib/cmsis-svd/data/STMicro/ src/device/stm32/
 	GO111MODULE=off $(GO) fmt ./src/device/stm32
@@ -148,13 +161,13 @@ gen-device-stm32: build/gen-device-svd
 
 # Get LLVM sources.
 $(LLVM_PROJECTDIR)/README.md:
-	git clone -b release/10.x https://github.com/llvm/llvm-project $(LLVM_PROJECTDIR)
+	git clone -b xtensa_release_10.0.1 --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
 llvm-source: $(LLVM_PROJECTDIR)/README.md
 
 # Configure LLVM.
 TINYGO_SOURCE_DIR=$(shell pwd)
 $(LLVM_BUILDDIR)/build.ninja: llvm-source
-	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
+	mkdir -p $(LLVM_BUILDDIR); cd $(LLVM_BUILDDIR); cmake -G Ninja $(TINYGO_SOURCE_DIR)/$(LLVM_PROJECTDIR)/llvm "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64;RISCV;WebAssembly" "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=AVR;Xtensa" -DCMAKE_BUILD_TYPE=Release -DLIBCLANG_BUILD_STATIC=ON -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_LIBEDIT=OFF -DLLVM_ENABLE_Z3_SOLVER=OFF -DLLVM_ENABLE_OCAMLDOC=OFF -DLLVM_ENABLE_PROJECTS="clang;lld" -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF $(LLVM_OPTION)
 
 # Build LLVM.
 $(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
@@ -165,24 +178,31 @@ $(LLVM_BUILDDIR): $(LLVM_BUILDDIR)/build.ninja
 .PHONY: wasi-libc
 wasi-libc: lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a
 lib/wasi-libc/sysroot/lib/wasm32-wasi/libc.a:
+	@if [ ! -e lib/wasi-libc/Makefile ]; then echo "Submodules have not been downloaded. Please download them using:\n  git submodule update --init"; exit 1; fi
 	cd lib/wasi-libc && make -j4 WASM_CC=$(CLANG) WASM_AR=$(LLVM_AR) WASM_NM=$(LLVM_NM)
 
 
 # Build the Go compiler.
 tinygo:
 	@if [ ! -f "$(LLVM_BUILDDIR)/bin/llvm-config" ]; then echo "Fetch and build LLVM first by running:"; echo "  make llvm-source"; echo "  make $(LLVM_BUILDDIR)"; exit 1; fi
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -o build/tinygo$(EXE) -tags byollvm .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) build -buildmode exe -o build/tinygo$(EXE) -tags byollvm -ldflags="-X main.gitSha1=`git rev-parse --short HEAD`" .
 
 test: wasi-libc
-	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -tags byollvm ./cgo ./compileopts ./interp ./transform .
+	CGO_CPPFLAGS="$(CGO_CPPFLAGS)" CGO_CXXFLAGS="$(CGO_CXXFLAGS)" CGO_LDFLAGS="$(CGO_LDFLAGS)" $(GO) test -v -buildmode exe -tags byollvm ./cgo ./compileopts ./interp ./transform .
 
+# Test known-working standard library packages.
+# TODO: do this in one command, parallelize, and only show failing tests (no
+# implied -v flag).
+.PHONY: tinygo-test
 tinygo-test:
-	cd tests/tinygotest && tinygo test
+	$(TINYGO) test container/list
+	$(TINYGO) test container/ring
+	$(TINYGO) test text/scanner
 
 .PHONY: smoketest
 smoketest:
 	$(TINYGO) version
-	# test all examples
+	# test all examples (except pwm)
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/adc
@@ -203,7 +223,7 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=microbit            examples/microbit-blink
 	@$(MD5SUM) test.hex
-	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pwm
+	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/pininterrupt
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10040            examples/serial
 	@$(MD5SUM) test.hex
@@ -231,6 +251,8 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=microbit            examples/echo
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=microbit-s110v8     examples/echo
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=nrf52840-mdk        examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pca10031            examples/blinky1
@@ -257,6 +279,10 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=stm32f4disco        examples/blinky2
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=stm32f4disco-1      examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-stm32f405   examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/i2s
@@ -291,11 +317,36 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=reelboard-s140v7    examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=wioterminal         examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pygamer             examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=xiao                examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/dac
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/dac
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-nrf52840  	examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-nrf52840  examples/blinky1
+	@$(MD5SUM) test.hex
+	# test pwm
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m4        examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4          examples/pwm
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pyportal            examples/pwm
+	@$(MD5SUM) test.hex
 ifneq ($(AVR), 0)
 	$(TINYGO) build -size short -o test.hex -target=atmega1284p         examples/serial
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino             examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=arduino             examples/pwm
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino -scheduler=tasks  examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=arduino-nano        examples/blinky1
@@ -304,13 +355,31 @@ ifneq ($(AVR), 0)
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=digispark -gc=leaking examples/blinky1
 	@$(MD5SUM) test.hex
+endif
+ifneq ($(XTENSA), 0)
+	$(TINYGO) build -size short -o test.bin -target=esp32-wroom-32      examples/blinky1
+	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=nodemcu             examples/blinky1
+	@$(MD5SUM) test.bin
 endif
 	$(TINYGO) build -size short -o test.hex -target=hifive1b            examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=maixbit             examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/export
 	$(TINYGO) build             -o wasm.wasm -target=wasm               examples/wasm/main
+	# test various compiler flags
+	$(TINYGO) build -size short -o test.hex -target=pca10040 -gc=none -scheduler=none examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pca10040 -opt=1     examples/blinky1
+	@$(MD5SUM) test.hex
+	$(TINYGO) build             -o test.nro -target=nintendoswitch      examples/serial
+	@$(MD5SUM) test.nro
 
-release: tinygo gen-device wasi-libc
+wasmtest:
+	$(GO) test ./tests/wasm
+
+build/release: tinygo gen-device wasi-libc
 	@mkdir -p build/release/tinygo/bin
 	@mkdir -p build/release/tinygo/lib/clang/include
 	@mkdir -p build/release/tinygo/lib/CMSIS/CMSIS
@@ -345,4 +414,13 @@ release: tinygo gen-device wasi-libc
 	./build/tinygo build-library -target=armv6m-none-eabi  -o build/release/tinygo/pkg/armv6m-none-eabi/picolibc.a picolibc
 	./build/tinygo build-library -target=armv7m-none-eabi  -o build/release/tinygo/pkg/armv7m-none-eabi/picolibc.a picolibc
 	./build/tinygo build-library -target=armv7em-none-eabi -o build/release/tinygo/pkg/armv7em-none-eabi/picolibc.a picolibc
+
+release: build/release
 	tar -czf build/release.tar.gz -C build/release tinygo
+
+deb: build/release
+	@mkdir -p build/release-deb/usr/local/bin
+	@mkdir -p build/release-deb/usr/local/lib
+	cp -ar build/release/tinygo build/release-deb/usr/local/lib/tinygo
+	ln -sf ../lib/tinygo/bin/tinygo build/release-deb/usr/local/bin/tinygo
+	fpm -f -s dir -t deb -n tinygo -v $(shell grep "const Version = " goenv/version.go | awk '{print $$NF}') -m '@tinygo-org' --description='TinyGo is a Go compiler for small places.' --license='BSD 3-Clause' --url=https://tinygo.org/ --deb-changelog CHANGELOG.md -p build/release.deb -C ./build/release-deb

README.md

@@ -43,27 +43,35 @@ See the [getting started instructions](https://tinygo.org/getting-started/) for
 
 You can compile TinyGo programs for microcontrollers, WebAssembly and Linux.
 
-The following 32 microcontroller boards are currently supported:
+The following 44 microcontroller boards are currently supported:
 
 * [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
 * [Adafruit Circuit Playground Express](https://www.adafruit.com/product/3333)
 * [Adafruit CLUE Alpha](https://www.adafruit.com/product/4500)
 * [Adafruit Feather M0](https://www.adafruit.com/product/2772)
 * [Adafruit Feather M4](https://www.adafruit.com/product/3857)
+* [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062)
+* [Adafruit Feather STM32F405 Express](https://www.adafruit.com/product/4382)
 * [Adafruit ItsyBitsy M0](https://www.adafruit.com/product/3727)
 * [Adafruit ItsyBitsy M4](https://www.adafruit.com/product/3800)
+* [Adafruit ItsyBitsy nRF52840](https://www.adafruit.com/product/4481)
 * [Adafruit Metro M4 Express Airlift](https://www.adafruit.com/product/4000)
 * [Adafruit PyBadge](https://www.adafruit.com/product/4200)
+* [Adafruit PyGamer](https://www.adafruit.com/product/4242)
 * [Adafruit PyPortal](https://www.adafruit.com/product/4116)
 * [Adafruit Trinket M0](https://www.adafruit.com/product/3500)
 * [Arduino Mega 2560](https://store.arduino.cc/arduino-mega-2560-rev3)
 * [Arduino Nano](https://store.arduino.cc/arduino-nano)
 * [Arduino Nano33 IoT](https://store.arduino.cc/nano-33-iot)
 * [Arduino Uno](https://store.arduino.cc/arduino-uno-rev3)
+* [Arduino Zero](https://store.arduino.cc/usa/arduino-zero)
 * [BBC micro:bit](https://microbit.org/)
 * [Digispark](http://digistump.com/products/1)
+* [ESP32](https://www.espressif.com/en/products/socs/esp32)
+* [ESP8266](https://www.espressif.com/en/products/socs/esp8266)
 * [Game Boy Advance](https://en.wikipedia.org/wiki/Game_Boy_Advance)
 * [Makerdiary nRF52840-MDK](https://wiki.makerdiary.com/nrf52840-mdk/)
+* [Nintendo Switch](https://www.nintendo.com/switch/)
 * [Nordic Semiconductor PCA10031](https://www.nordicsemi.com/eng/Products/nRF51-Dongle)
 * [Nordic Semiconductor PCA10040](https://www.nordicsemi.com/eng/Products/Bluetooth-low-energy/nRF52-DK)
 * [Nordic Semiconductor PCA10056](https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-DK)
@@ -72,6 +80,10 @@ The following 32 microcontroller boards are currently supported:
 * [Particle Xenon](https://docs.particle.io/datasheets/discontinued/xenon-datasheet/)
 * [Phytec reel board](https://www.phytec.eu/product-eu/internet-of-things/reelboard/)
 * [PineTime DevKit](https://www.pine64.org/pinetime/)
+* [PJRC Teensy 3.6](https://www.pjrc.com/store/teensy36.html)
+* [Seeed Wio Terminal](https://www.seeedstudio.com/Wio-Terminal-p-4509.html)
+* [Seeed Seeeduino XIAO](https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html)
+* [Seeed Sipeed MAix BiT](https://www.seeedstudio.com/Sipeed-MAix-BiT-for-RISC-V-AI-IoT-p-2872.html)
 * [SiFIve HiFive1](https://www.sifive.com/boards/hifive1)
 * [ST Micro "Nucleo F103RB"](https://www.st.com/en/evaluation-tools/nucleo-f103rb.html)
 * [ST Micro STM32F103XX "Bluepill"](http://wiki.stm32duino.com/index.php?title=Blue_Pill)
@@ -137,3 +149,5 @@ The original reasoning was: if [Python](https://micropython.org/) can run on mic
 This project is licensed under the BSD 3-clause license, just like the [Go project](https://golang.org/LICENSE) itself.
 
 Some code has been copied from the LLVM project and is therefore licensed under [a variant of the Apache 2.0 license](http://releases.llvm.org/10.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.
+
+Some code has been copied and/or ported from Paul Stoffregen's Teensy libraries and is therefore licensed under PJRC's license. This has been clearly indicated in the header of these files.

azure-pipelines.yml

@@ -1,7 +1,7 @@
 # Avoid lengthy LLVM rebuilds on each newly pushed branch. Pull requests will
 # be built anyway.
 trigger:
-- master
+- release
 - dev
 
 jobs:
@@ -12,22 +12,27 @@ jobs:
   steps:
     - task: GoTool@0
       inputs:
-        version: '1.14.1'
+        version: '1.15'
     - checkout: self
-    - task: CacheBeta@0
+      fetchDepth: 1
+    - task: Cache@2
       displayName: Cache LLVM source
       inputs:
-        key: llvm-source-10-windows-v0
+        key: llvm-source-10-windows-v1
         path: llvm-project
     - task: Bash@3
       displayName: Download LLVM source
       inputs:
         targetType: inline
-        script: make llvm-source
+        script: |
+          make llvm-source
+          # Workaround for bad symlinks:
+          # https://github.com/microsoft/azure-pipelines-tasks/issues/13418
+          rm -f llvm-project/libcxx/test/std/input.output/filesystems/Inputs/static_test_env/bad_symlink
     - task: CacheBeta@0
       displayName: Cache LLVM build
       inputs:
-        key: llvm-build-10-windows-v0
+        key: llvm-build-10-windows-v1
         path: llvm-build
     - task: Bash@3
       displayName: Build LLVM
@@ -43,11 +48,11 @@ jobs:
       displayName: Install QEMU
       inputs:
         targetType: inline
-        script: choco install qemu
+        script: choco install qemu --version=2020.06.12
     - task: CacheBeta@0
       displayName: Cache wasi-libc sysroot
       inputs:
-        key: wasi-libc-sysroot-v2
+        key: wasi-libc-sysroot-v3
         path: lib/wasi-libc/sysroot
     - task: Bash@3
       displayName: Build wasi-libc
@@ -69,7 +74,7 @@ jobs:
         script: |
           export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
           unset GOROOT
-          make release -j4
+          make build/release -j4
     - publish: $(System.DefaultWorkingDirectory)/build/release/tinygo
       displayName: Publish zip as artifact
       artifact: tinygo
@@ -80,4 +85,4 @@ jobs:
         script: |
           export PATH="$PATH:./llvm-build/bin:/c/Program Files/qemu"
           unset GOROOT
-          make smoketest TINYGO=build/tinygo AVR=0
+          make smoketest TINYGO=build/tinygo AVR=0 XTENSA=0

builder/build.go

@@ -4,11 +4,14 @@
 package builder
 
 import (
+	"debug/elf"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -16,26 +19,40 @@ import (
 	"github.com/tinygo-org/tinygo/compiler"
 	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/interp"
+	"github.com/tinygo-org/tinygo/stacksize"
 	"github.com/tinygo-org/tinygo/transform"
 	"tinygo.org/x/go-llvm"
 )
 
+// 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 {
+	// 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.
+	Binary string
+
+	// The directory of the main package. This is useful for testing as the test
+	// binary must be run in the directory of the tested package.
+	MainDir string
+}
+
 // Build performs a single package to executable Go build. It takes in a package
 // name, an output path, and set of compile options and from that it manages the
 // whole compilation process.
 //
 // The error value may be of type *MultiError. Callers will likely want to check
 // for this case and print such errors individually.
-func Build(pkgName, outpath string, config *compileopts.Config, action func(string) error) error {
+func Build(pkgName, outpath string, config *compileopts.Config, action func(BuildResult) error) error {
 	// Compile Go code to IR.
 	machine, err := compiler.NewTargetMachine(config)
 	if err != nil {
 		return err
 	}
-	mod, extraFiles, errs := compiler.Compile(pkgName, machine, config)
+	buildOutput, errs := compiler.Compile(pkgName, machine, config)
 	if errs != nil {
 		return newMultiError(errs)
 	}
+	mod := buildOutput.Mod
 
 	if config.Options.PrintIR {
 		fmt.Println("; Generated LLVM IR:")
@@ -73,8 +90,15 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 	// exactly.
 	errs = nil
 	switch config.Options.Opt {
-	case "none", "0":
+	/*
-		errs = transform.Optimize(mod, config, 0, 0, 0) // -O0
+		Currently, turning optimizations off causes compile failures.
+		We rely on the optimizer removing some dead symbols.
+		Avoid providing an option that does not work right now.
+		In the future once everything has been fixed we can re-enable this.
+
+		case "none", "0":
+			errs = transform.Optimize(mod, config, 0, 0, 0) // -O0
+	*/
 	case "1":
 		errs = transform.Optimize(mod, config, 1, 0, 0) // -O1
 	case "2":
@@ -105,6 +129,13 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 		}
 	}
 
+	// Make sure stack sizes are loaded from a separate section so they can be
+	// modified after linking.
+	var stackSizeLoads []string
+	if config.AutomaticStackSize() {
+		stackSizeLoads = transform.CreateStackSizeLoads(mod, config)
+	}
+
 	// Generate output.
 	outext := filepath.Ext(outpath)
 	switch outext {
@@ -178,7 +209,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 		}
 
 		// Compile C files in packages.
-		for i, file := range extraFiles {
+		for i, file := range buildOutput.ExtraFiles {
 			outpath := filepath.Join(dir, "pkg"+strconv.Itoa(i)+"-"+filepath.Base(file)+".o")
 			err := runCCompiler(config.Target.Compiler, append(config.CFlags(), "-c", "-o", outpath, file)...)
 			if err != nil {
@@ -187,12 +218,36 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 			ldflags = append(ldflags, outpath)
 		}
 
+		if len(buildOutput.ExtraLDFlags) > 0 {
+			ldflags = append(ldflags, buildOutput.ExtraLDFlags...)
+		}
+
 		// Link the object files together.
 		err = link(config.Target.Linker, ldflags...)
 		if err != nil {
 			return &commandError{"failed to link", executable, err}
 		}
 
+		var calculatedStacks []string
+		var stackSizes map[string]functionStackSize
+		if config.Options.PrintStacks || config.AutomaticStackSize() {
+			// Try to determine stack sizes at compile time.
+			// Don't do this by default as it usually doesn't work on
+			// unsupported architectures.
+			calculatedStacks, stackSizes, err = determineStackSizes(mod, executable)
+			if err != nil {
+				return err
+			}
+		}
+		if config.AutomaticStackSize() {
+			// Modify the .tinygo_stacksizes section that contains a stack size
+			// for each goroutine.
+			err = modifyStackSizes(executable, stackSizeLoads, stackSizes)
+			if err != nil {
+				return fmt.Errorf("could not modify stack sizes: %w", err)
+			}
+		}
+
 		if config.Options.PrintSizes == "short" || config.Options.PrintSizes == "full" {
 			sizes, err := loadProgramSize(executable)
 			if err != nil {
@@ -212,21 +267,278 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(stri
 			}
 		}
 
+		// Print goroutine stack sizes, as far as possible.
+		if config.Options.PrintStacks {
+			printStacks(calculatedStacks, stackSizes)
+		}
+
 		// Get an Intel .hex file or .bin file from the .elf file.
-		if outext == ".hex" || outext == ".bin" || outext == ".gba" {
+		outputBinaryFormat := config.BinaryFormat(outext)
+		switch outputBinaryFormat {
+		case "elf":
+			// do nothing, file is already in ELF format
+		case "hex", "bin":
+			// Extract raw binary, either encoding it as a hex file or as a raw
+			// firmware file.
 			tmppath = filepath.Join(dir, "main"+outext)
-			err := objcopy(executable, tmppath)
+			err := objcopy(executable, tmppath, outputBinaryFormat)
 			if err != nil {
 				return err
 			}
-		} else if outext == ".uf2" {
+		case "uf2":
 			// Get UF2 from the .elf file.
 			tmppath = filepath.Join(dir, "main"+outext)
 			err := convertELFFileToUF2File(executable, tmppath, config.Target.UF2FamilyID)
 			if err != nil {
 				return err
 			}
+		case "esp32", "esp8266":
+			// Special format for the ESP family of chips (parsed by the ROM
+			// bootloader).
+			tmppath = filepath.Join(dir, "main"+outext)
+			err := makeESPFirmareImage(executable, tmppath, outputBinaryFormat)
+			if err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("unknown output binary format: %s", outputBinaryFormat)
+		}
+		return action(BuildResult{
+			Binary:  tmppath,
+			MainDir: buildOutput.MainDir,
+		})
+	}
+}
+
+// functionStackSizes keeps stack size information about a single function
+// (usually a goroutine).
+type functionStackSize struct {
+	humanName        string
+	stackSize        uint64
+	stackSizeType    stacksize.SizeType
+	missingStackSize *stacksize.CallNode
+}
+
+// determineStackSizes tries to determine the stack sizes of all started
+// goroutines and of the reset vector. The LLVM module is necessary to find
+// functions that call a function pointer.
+func determineStackSizes(mod llvm.Module, executable string) ([]string, map[string]functionStackSize, error) {
+	var callsIndirectFunction []string
+	gowrappers := []string{}
+	gowrapperNames := make(map[string]string)
+	for fn := mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
+		// Determine which functions call a function pointer.
+		for bb := fn.FirstBasicBlock(); !bb.IsNil(); bb = llvm.NextBasicBlock(bb) {
+			for inst := bb.FirstInstruction(); !inst.IsNil(); inst = llvm.NextInstruction(inst) {
+				if inst.IsACallInst().IsNil() {
+					continue
+				}
+				if callee := inst.CalledValue(); callee.IsAFunction().IsNil() && callee.IsAInlineAsm().IsNil() {
+					callsIndirectFunction = append(callsIndirectFunction, fn.Name())
+				}
+			}
+		}
+
+		// Get a list of "go wrappers", small wrapper functions that decode
+		// parameters when starting a new goroutine.
+		attr := fn.GetStringAttributeAtIndex(-1, "tinygo-gowrapper")
+		if !attr.IsNil() {
+			gowrappers = append(gowrappers, fn.Name())
+			gowrapperNames[fn.Name()] = attr.GetStringValue()
+		}
+	}
+	sort.Strings(gowrappers)
+
+	// Load the ELF binary.
+	f, err := elf.Open(executable)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not load executable for stack size analysis: %w", err)
+	}
+	defer f.Close()
+
+	// Determine the frame size of each function (if available) and the callgraph.
+	functions, err := stacksize.CallGraph(f, callsIndirectFunction)
+	if err != nil {
+		return nil, nil, fmt.Errorf("could not parse executable for stack size analysis: %w", err)
+	}
+
+	// Goroutines need to be started and finished and take up some stack space
+	// that way. This can be measured by measuing the stack size of
+	// tinygo_startTask.
+	if numFuncs := len(functions["tinygo_startTask"]); numFuncs != 1 {
+		return nil, nil, fmt.Errorf("expected exactly one definition of tinygo_startTask, got %d", numFuncs)
+	}
+	baseStackSize, baseStackSizeType, baseStackSizeFailedAt := functions["tinygo_startTask"][0].StackSize()
+
+	sizes := make(map[string]functionStackSize)
+
+	// Add the reset handler function, for convenience. The reset handler runs
+	// startup code and the scheduler. The listed stack size is not the full
+	// stack size: interrupts are not counted.
+	var resetFunction string
+	switch f.Machine {
+	case elf.EM_ARM:
+		// Note: all interrupts happen on this stack so the real size is bigger.
+		resetFunction = "Reset_Handler"
+	}
+	if resetFunction != "" {
+		funcs := functions[resetFunction]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", resetFunction, len(funcs))
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		sizes[resetFunction] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        resetFunction,
+		}
+	}
+
+	// Add all goroutine wrapper functions.
+	for _, name := range gowrappers {
+		funcs := functions[name]
+		if len(funcs) != 1 {
+			return nil, nil, fmt.Errorf("expected exactly one definition of %s in the callgraph, found %d", name, len(funcs))
+		}
+		humanName := gowrapperNames[name]
+		if humanName == "" {
+			humanName = name // fallback
+		}
+		stackSize, stackSizeType, missingStackSize := funcs[0].StackSize()
+		if baseStackSizeType != stacksize.Bounded {
+			// It was not possible to determine the stack size at compile time
+			// because tinygo_startTask does not have a fixed stack size. This
+			// can happen when using -opt=1.
+			stackSizeType = baseStackSizeType
+			missingStackSize = baseStackSizeFailedAt
+		} else if stackSize < baseStackSize {
+			// This goroutine has a very small stack, but still needs to fit all
+			// registers to start and suspend the goroutine. Otherwise a stack
+			// overflow will occur even before the goroutine is started.
+			stackSize = baseStackSize
+		}
+		sizes[name] = functionStackSize{
+			stackSize:        stackSize,
+			stackSizeType:    stackSizeType,
+			missingStackSize: missingStackSize,
+			humanName:        humanName,
+		}
+	}
+
+	if resetFunction != "" {
+		return append([]string{resetFunction}, gowrappers...), sizes, nil
+	}
+	return gowrappers, sizes, nil
+}
+
+// modifyStackSizes modifies the .tinygo_stacksizes section with the updated
+// stack size information. Before this modification, all stack sizes in the
+// section assume the default stack size (which is relatively big).
+func modifyStackSizes(executable string, stackSizeLoads []string, stackSizes map[string]functionStackSize) error {
+	fp, err := os.OpenFile(executable, os.O_RDWR, 0)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+
+	elfFile, err := elf.NewFile(fp)
+	if err != nil {
+		return err
+	}
+
+	section := elfFile.Section(".tinygo_stacksizes")
+	if section == nil {
+		return errors.New("could not find .tinygo_stacksizes section")
+	}
+
+	if section.Size != section.FileSize {
+		// Sanity check.
+		return fmt.Errorf("expected .tinygo_stacksizes to have identical size and file size, got %d and %d", section.Size, section.FileSize)
+	}
+
+	// Read all goroutine stack sizes.
+	data := make([]byte, section.Size)
+	_, err = fp.ReadAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	if len(stackSizeLoads)*4 != len(data) {
+		// Note: while AVR should use 2 byte stack sizes, even 64-bit platforms
+		// should probably stick to 4 byte stack sizes as a larger than 4GB
+		// stack doesn't make much sense.
+		return errors.New("expected 4 byte stack sizes")
+	}
+
+	// Modify goroutine stack sizes with a compile-time known worst case stack
+	// size.
+	for i, name := range stackSizeLoads {
+		fn, ok := stackSizes[name]
+		if !ok {
+			return fmt.Errorf("could not find symbol %s in ELF file", name)
+		}
+		if fn.stackSizeType == stacksize.Bounded {
+			stackSize := uint32(fn.stackSize)
+
+			// Adding 4 for the stack canary. Even though the size may be
+			// automatically determined, stack overflow checking is still
+			// important as the stack size cannot be determined for all
+			// goroutines.
+			stackSize += 4
+
+			// Add stack size used by interrupts.
+			switch elfFile.Machine {
+			case elf.EM_ARM:
+				// On Cortex-M (assumed here), this stack size is 8 words or 32
+				// bytes. This is only to store the registers that the interrupt
+				// may modify, the interrupt will switch to the interrupt stack
+				// (MSP).
+				// Some background:
+				// https://interrupt.memfault.com/blog/cortex-m-rtos-context-switching
+				stackSize += 32
+			}
+
+			// Finally write the stack size to the binary.
+			binary.LittleEndian.PutUint32(data[i*4:], stackSize)
+		}
+	}
+
+	// Write back the modified stack sizes.
+	_, err = fp.WriteAt(data, int64(section.Offset))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// printStacks prints the maximum stack depth for functions that are started as
+// goroutines. Stack sizes cannot always be determined statically, in particular
+// recursive functions and functions that call interface methods or function
+// pointers may have an unknown stack depth (depending on what the optimizer
+// manages to optimize away).
+//
+// It might print something like the following:
+//
+//     function                         stack usage (in bytes)
+//     Reset_Handler                    316
+//     examples/blinky2.led1            92
+//     runtime.run$1                    300
+func printStacks(calculatedStacks []string, stackSizes map[string]functionStackSize) {
+	// Print the sizes of all stacks.
+	fmt.Printf("%-32s %s\n", "function", "stack usage (in bytes)")
+	for _, name := range calculatedStacks {
+		fn := stackSizes[name]
+		switch fn.stackSizeType {
+		case stacksize.Bounded:
+			fmt.Printf("%-32s %d\n", fn.humanName, fn.stackSize)
+		case stacksize.Unknown:
+			fmt.Printf("%-32s unknown, %s does not have stack frame information\n", fn.humanName, fn.missingStackSize)
+		case stacksize.Recursive:
+			fmt.Printf("%-32s recursive, %s may call itself\n", fn.humanName, fn.missingStackSize)
+		case stacksize.IndirectCall:
+			fmt.Printf("%-32s unknown, %s calls a function pointer\n", fn.humanName, fn.missingStackSize)
 		}
-		return action(tmppath)
 	}
 }

builder/config.go

@@ -21,12 +21,12 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if goroot == "" {
 		return nil, errors.New("cannot locate $GOROOT, please set it manually")
 	}
-	major, minor, err := getGorootVersion(goroot)
+	major, minor, err := goenv.GetGorootVersion(goroot)
 	if err != nil {
 		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
 	}
-	if major != 1 || minor < 11 || minor > 14 {
+	if major != 1 || minor < 11 || minor > 15 {
-		return nil, fmt.Errorf("requires go version 1.11, 1.12, 1.13, or 1.14, got go%d.%d", major, minor)
+		return nil, fmt.Errorf("requires go version 1.11 through 1.15, got go%d.%d", major, minor)
 	}
 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))
 	return &compileopts.Config{

builder/env.go

@@ -1,71 +1,13 @@
 package builder
 
 import (
-	"errors"
-	"fmt"
-	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
-	"regexp"
 	"sort"
-	"strings"
 )
 
-// getGorootVersion returns the major and minor version for a given GOROOT path.
-// If the goroot cannot be determined, (0, 0) is returned.
-func getGorootVersion(goroot string) (major, minor int, err error) {
-	s, err := GorootVersionString(goroot)
-	if err != nil {
-		return 0, 0, err
-	}
-
-	if s == "" || s[:2] != "go" {
-		return 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
-	}
-
-	parts := strings.Split(s[2:], ".")
-	if len(parts) < 2 {
-		return 0, 0, errors.New("could not parse Go version: version has less than two parts")
-	}
-
-	// Ignore the errors, we don't really handle errors here anyway.
-	var trailing string
-	n, err := fmt.Sscanf(s, "go%d.%d%s", &major, &minor, &trailing)
-	if n == 2 && err == io.EOF {
-		// Means there were no trailing characters (i.e., not an alpha/beta)
-		err = nil
-	}
-	if err != nil {
-		return 0, 0, fmt.Errorf("failed to parse version: %s", err)
-	}
-	return
-}
-
-// GorootVersionString returns the version string as reported by the Go
-// toolchain for the given GOROOT path. It is usually of the form `go1.x.y` but
-// can have some variations (for beta releases, for example).
-func GorootVersionString(goroot string) (string, error) {
-	if data, err := ioutil.ReadFile(filepath.Join(
-		goroot, "src", "runtime", "internal", "sys", "zversion.go")); err == nil {
-
-		r := regexp.MustCompile("const TheVersion = `(.*)`")
-		matches := r.FindSubmatch(data)
-		if len(matches) != 2 {
-			return "", errors.New("Invalid go version output:\n" + string(data))
-		}
-
-		return string(matches[1]), nil
-
-	} else if data, err := ioutil.ReadFile(filepath.Join(goroot, "VERSION")); err == nil {
-		return string(data), nil
-
-	} else {
-		return "", err
-	}
-}
-
 // getClangHeaderPath returns the path to the built-in Clang headers. It tries
 // multiple locations, which should make it find the directory when installed in
 // various ways.

builder/esp.go

@@ -0,0 +1,153 @@
+package builder
+
+// This file implements support for writing ESP image files. These image files
+// are read by the ROM bootloader so have to be in a particular format.
+//
+// In the future, it may be necessary to implement support for other image
+// formats, such as the ESP8266 image formats (again, used by the ROM bootloader
+// to load the firmware).
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"debug/elf"
+	"encoding/binary"
+	"fmt"
+	"io/ioutil"
+	"sort"
+)
+
+type espImageSegment struct {
+	addr uint32
+	data []byte
+}
+
+// makeESPFirmare converts an input ELF file to an image file for an ESP32 or
+// ESP8266 chip. This is a special purpose image format just for the ESP chip
+// family, and is parsed by the on-chip mask ROM bootloader.
+//
+// The following documentation has been used:
+// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+// https://github.com/espressif/esp-idf/blob/8fbb63c2a701c22ccf4ce249f43aded73e134a34/components/bootloader_support/include/esp_image_format.h#L58
+// https://github.com/espressif/esptool/blob/master/esptool.py
+func makeESPFirmareImage(infile, outfile, format string) error {
+	inf, err := elf.Open(infile)
+	if err != nil {
+		return err
+	}
+	defer inf.Close()
+
+	// Load all segments to be written to the image. These are actually ELF
+	// sections, not true ELF segments (similar to how esptool does it).
+	var segments []*espImageSegment
+	for _, section := range inf.Sections {
+		if section.Type != elf.SHT_PROGBITS || section.Size == 0 || section.Flags&elf.SHF_ALLOC == 0 {
+			continue
+		}
+		data, err := section.Data()
+		if err != nil {
+			return fmt.Errorf("failed to read section data: %w", err)
+		}
+		for len(data)%4 != 0 {
+			// Align segment to 4 bytes.
+			data = append(data, 0)
+		}
+		if uint64(uint32(section.Addr)) != section.Addr {
+			return fmt.Errorf("section address too big: 0x%x", section.Addr)
+		}
+		segments = append(segments, &espImageSegment{
+			addr: uint32(section.Addr),
+			data: data,
+		})
+	}
+
+	// Sort the segments by address. This is what esptool does too.
+	sort.SliceStable(segments, func(i, j int) bool { return segments[i].addr < segments[j].addr })
+
+	// Calculate checksum over the segment data. This is used in the image
+	// footer.
+	checksum := uint8(0xef)
+	for _, segment := range segments {
+		for _, b := range segment.data {
+			checksum ^= b
+		}
+	}
+
+	// Write first to an in-memory buffer, primarily so that we can easily
+	// calculate a hash over the entire image.
+	// An added benefit is that we don't need to check for errors all the time.
+	outf := &bytes.Buffer{}
+
+	// Image header.
+	switch format {
+	case "esp32":
+		// Header format:
+		// https://github.com/espressif/esp-idf/blob/8fbb63c2/components/bootloader_support/include/esp_image_format.h#L58
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+			wp_pin         uint8
+			spi_pin_drv    [3]uint8
+			reserved       [11]uint8
+			hash_appended  bool
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0, // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+			wp_pin:         0xEE, // disable WP pin
+			hash_appended:  true, // add a SHA256 hash
+		})
+	case "esp8266":
+		// Header format:
+		// https://github.com/espressif/esptool/wiki/Firmware-Image-Format
+		// Basically a truncated version of the ESP32 header.
+		binary.Write(outf, binary.LittleEndian, struct {
+			magic          uint8
+			segment_count  uint8
+			spi_mode       uint8
+			spi_speed_size uint8
+			entry_addr     uint32
+		}{
+			magic:          0xE9,
+			segment_count:  byte(len(segments)),
+			spi_mode:       0,    // irrelevant, replaced by esptool when flashing
+			spi_speed_size: 0x20, // spi_speed, spi_size: replaced by esptool when flashing
+			entry_addr:     uint32(inf.Entry),
+		})
+	default:
+		return fmt.Errorf("builder: unknown binary format %#v, expected esp32 or esp8266", format)
+	}
+
+	// Write all segments to the image.
+	// https://github.com/espressif/esptool/wiki/Firmware-Image-Format#segment
+	for _, segment := range segments {
+		binary.Write(outf, binary.LittleEndian, struct {
+			addr   uint32
+			length uint32
+		}{
+			addr:   segment.addr,
+			length: uint32(len(segment.data)),
+		})
+		outf.Write(segment.data)
+	}
+
+	// Footer, including checksum.
+	// The entire image size must be a multiple of 16, so pad the image to one
+	// byte less than that before writing the checksum.
+	outf.Write(make([]byte, 15-outf.Len()%16))
+	outf.WriteByte(checksum)
+
+	if format == "esp32" {
+		// SHA256 hash (to protect against image corruption, not for security).
+		hash := sha256.Sum256(outf.Bytes())
+		outf.Write(hash[:])
+	}
+
+	// Write the image to the output file.
+	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
+}

builder/library.go

@@ -69,11 +69,14 @@ func (l *Library) Load(target string) (path string, err error) {
 	// Precalculate the flags to the compiler invocation.
 	args := append(l.cflags(), "-c", "-Oz", "-g", "-ffunction-sections", "-fdata-sections", "-Wno-macro-redefined", "--target="+target, "-fdebug-prefix-map="+dir+"="+remapDir)
 	if strings.HasPrefix(target, "arm") || strings.HasPrefix(target, "thumb") {
-		args = append(args, "-fshort-enums", "-fomit-frame-pointer")
+		args = append(args, "-fshort-enums", "-fomit-frame-pointer", "-mfloat-abi=soft")
 	}
 	if strings.HasPrefix(target, "riscv32-") {
 		args = append(args, "-march=rv32imac", "-mabi=ilp32", "-fforce-enable-int128")
 	}
+	if strings.HasPrefix(target, "riscv64-") {
+		args = append(args, "-march=rv64gc", "-mabi=lp64")
+	}
 
 	// Compile all sources.
 	var objs []string

builder/objcopy.go

@@ -4,12 +4,15 @@ import (
 	"debug/elf"
 	"io/ioutil"
 	"os"
-	"path/filepath"
 	"sort"
 
 	"github.com/marcinbor85/gohex"
 )
 
+// maxPadBytes is the maximum allowed bytes to be padded in a rom extraction
+// this value is currently defined by Nintendo Switch Page Alignment (4096 bytes)
+const maxPadBytes = 4095
+
 // objcopyError is an error returned by functions that act like objcopy.
 type objcopyError struct {
 	Op  string
@@ -71,7 +74,12 @@ func extractROM(path string) (uint64, []byte, error) {
 	var rom []byte
 	for _, prog := range progs {
 		if prog.Paddr != progs[0].Paddr+uint64(len(rom)) {
-			return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+			diff := prog.Paddr - (progs[0].Paddr + uint64(len(rom)))
+			if diff > maxPadBytes {
+				return 0, nil, objcopyError{"ROM segments are non-contiguous: " + path, nil}
+			}
+			// Pad the difference
+			rom = append(rom, make([]byte, diff)...)
 		}
 		data, err := ioutil.ReadAll(prog.Open())
 		if err != nil {
@@ -93,7 +101,7 @@ func extractROM(path string) (uint64, []byte, error) {
 
 // objcopy converts an ELF file to a different (simpler) output file format:
 // .bin or .hex. It extracts only the .text section.
-func objcopy(infile, outfile string) error {
+func objcopy(infile, outfile, binaryFormat string) error {
 	f, err := os.OpenFile(outfile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
 	if err != nil {
 		return err
@@ -107,24 +115,20 @@ func objcopy(infile, outfile string) error {
 	}
 
 	// Write to the file, in the correct format.
-	switch filepath.Ext(outfile) {
+	switch binaryFormat {
-	case ".gba":
+	case "hex":
-		// The address is not stored in a .gba file.
+		// Intel hex file, includes the firmware start address.
-		_, err := f.Write(data)
-		return err
-	case ".bin":
-		// The address is not stored in a .bin file (therefore you
-		// should use .hex files in most cases).
-		_, err := f.Write(data)
-		return err
-	case ".hex":
 		mem := gohex.NewMemory()
 		err := mem.AddBinary(uint32(addr), data)
 		if err != nil {
 			return objcopyError{"failed to create .hex file", err}
 		}
-		mem.DumpIntelHex(f, 16) // TODO: handle error
+		return mem.DumpIntelHex(f, 16)
-		return nil
+	case "bin":
+		// The start address is not stored in raw firmware files (therefore you
+		// should use .hex files in most cases).
+		_, err := f.Write(data)
+		return err
 	default:
 		panic("unreachable")
 	}

cgo/cgo.go

@@ -41,6 +41,7 @@ type cgoPackage struct {
 	elaboratedTypes map[string]*elaboratedTypeInfo
 	enums           map[string]enumInfo
 	anonStructNum   int
+	ldflags         []string
 }
 
 // constantInfo stores some information about a CGo constant found by libclang
@@ -156,7 +157,7 @@ typedef unsigned long long  _Cgo_ulonglong;
 // newly created *ast.File that should be added to the list of to-be-parsed
 // files. If there is one or more error, it returns these in the []error slice
 // but still modifies the AST.
-func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string) (*ast.File, []error) {
+func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string) (*ast.File, []string, []error) {
 	p := &cgoPackage{
 		dir:             dir,
 		fset:            fset,
@@ -183,7 +184,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// Find the absolute path for this package.
 	packagePath, err := filepath.Abs(fset.File(files[0].Pos()).Name())
 	if err != nil {
-		return nil, []error{
+		return nil, nil, []error{
 			scanner.Error{
 				Pos: fset.Position(files[0].Pos()),
 				Msg: "cgo: cannot find absolute path: " + err.Error(), // TODO: wrap this error
@@ -359,6 +360,19 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 					}
 					makePathsAbsolute(flags, packagePath)
 					cflags = append(cflags, flags...)
+				case "LDFLAGS":
+					flags, err := shlex.Split(value)
+					if err != nil {
+						// TODO: find the exact location where the error happened.
+						p.addErrorAfter(comment.Slash, comment.Text[:lineStart+colon+1], "failed to parse flags in #cgo line: "+err.Error())
+						continue
+					}
+					if err := checkLinkerFlags(name, flags); err != nil {
+						p.addErrorAfter(comment.Slash, comment.Text[:lineStart+colon+1], err.Error())
+						continue
+					}
+					makePathsAbsolute(flags, packagePath)
+					p.ldflags = append(p.ldflags, flags...)
 				default:
 					startPos := strings.LastIndex(line[4:colon], name) + 4
 					p.addErrorAfter(comment.Slash, comment.Text[:lineStart+startPos], "invalid #cgo line: "+name)
@@ -412,7 +426,7 @@ func Process(files []*ast.File, dir string, fset *token.FileSet, cflags []string
 	// Print the newly generated in-memory AST, for debugging.
 	//ast.Print(fset, p.generated)
 
-	return p.generated, p.errors
+	return p.generated, p.ldflags, p.errors
 }
 
 // makePathsAbsolute converts some common path compiler flags (-I, -L) from

cgo/cgo_test.go

@@ -50,7 +50,7 @@ func TestCGo(t *testing.T) {
 			}
 
 			// Process the AST with CGo.
-			cgoAST, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)
+			cgoAST, _, cgoErrors := Process([]*ast.File{f}, "testdata", fset, cflags)
 
 			// Check the AST for type errors.
 			var typecheckErrors []error

cgo/libclang.go

@@ -246,9 +246,9 @@ func tinygo_clang_globals_visitor(c, parent C.GoCXCursor, client_data C.CXClient
 		}
 		value := source[len(name):]
 		// Try to convert this #define into a Go constant expression.
-		expr, err := parseConst(pos+token.Pos(len(name)), p.fset, value)
+		expr, scannerError := parseConst(pos+token.Pos(len(name)), p.fset, value)
-		if err != nil {
+		if scannerError != nil {
-			p.errors = append(p.errors, err)
+			p.errors = append(p.errors, *scannerError)
 		}
 		if expr != nil {
 			// Parsing was successful.

cgo/testdata/flags.go

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

cgo/testdata/flags.out.go

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

compileopts/config.go

@@ -129,8 +129,8 @@ func (c *Config) NeedsStackObjects() bool {
 	}
 }
 
-// Scheduler returns the scheduler implementation. Valid values are "coroutines"
+// Scheduler returns the scheduler implementation. Valid values are "none",
-// and "tasks".
+//"coroutines" and "tasks".
 func (c *Config) Scheduler() string {
 	if c.Options.Scheduler != "" {
 		return c.Options.Scheduler
@@ -164,6 +164,16 @@ func (c *Config) PanicStrategy() string {
 	return c.Options.PanicStrategy
 }
 
+// AutomaticStackSize returns whether goroutine stack sizes should be determined
+// automatically at compile time, if possible. If it is false, no attempt is
+// made.
+func (c *Config) AutomaticStackSize() bool {
+	if c.Target.AutoStackSize != nil && c.Scheduler() == "tasks" {
+		return *c.Target.AutoStackSize
+	}
+	return false
+}
+
 // CFlags returns the flags to pass to the C compiler. This is necessary for CGo
 // preprocessing.
 func (c *Config) CFlags() []string {
@@ -176,6 +186,9 @@ func (c *Config) CFlags() []string {
 		cflags = append(cflags, "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", filepath.Join(root, "lib", "picolibc", "newlib", "libc", "include"))
 		cflags = append(cflags, "-I"+filepath.Join(root, "lib/picolibc-include"))
 	}
+	if c.Debug() {
+		cflags = append(cflags, "-g")
+	}
 	return cflags
 }
 
@@ -226,6 +239,31 @@ func (c *Config) Debug() bool {
 	return c.Options.Debug
 }
 
+// BinaryFormat returns an appropriate binary format, based on the file
+// extension and the configured binary format in the target JSON file.
+func (c *Config) BinaryFormat(ext string) string {
+	switch ext {
+	case ".bin", ".gba", ".nro":
+		// The simplest format possible: dump everything in a raw binary file.
+		if c.Target.BinaryFormat != "" {
+			return c.Target.BinaryFormat
+		}
+		return "bin"
+	case ".hex":
+		// Similar to bin, but includes the start address and is thus usually a
+		// better format.
+		return "hex"
+	case ".uf2":
+		// Special purpose firmware format, mainly used on Adafruit boards.
+		// More information:
+		// https://github.com/Microsoft/uf2
+		return "uf2"
+	default:
+		// Use the ELF format for unrecognized file formats.
+		return "elf"
+	}
+}
+
 // Programmer returns the flash method and OpenOCD interface name given a
 // particular configuration. It may either be all configured in the target JSON
 // file or be modified using the -programmmer command-line option.
@@ -272,6 +310,25 @@ func (c *Config) OpenOCDConfiguration() (args []string, err error) {
 	return args, nil
 }
 
+// CodeModel returns the code model used on this platform.
+func (c *Config) CodeModel() string {
+	if c.Target.CodeModel != "" {
+		return c.Target.CodeModel
+	}
+
+	return "default"
+}
+
+// RelocationModel returns the relocation model in use on this platform. Valid
+// values are "static", "pic", "dynamicnopic".
+func (c *Config) RelocationModel() string {
+	if c.Target.RelocationModel != "" {
+		return c.Target.RelocationModel
+	}
+
+	return "static"
+}
+
 type TestConfig struct {
 	CompileTestBinary bool
 	// TODO: Filter the test functions to run, include verbose flag, etc

compileopts/options.go

@@ -1,5 +1,17 @@
 package compileopts
 
+import (
+	"fmt"
+	"strings"
+)
+
+var (
+	validGCOptions            = []string{"none", "leaking", "extalloc", "conservative"}
+	validSchedulerOptions     = []string{"none", "tasks", "coroutines"}
+	validPrintSizeOptions     = []string{"none", "short", "full"}
+	validPanicStrategyOptions = []string{"print", "trap"}
+)
+
 // Options contains extra options to give to the compiler. These options are
 // usually passed from the command line.
 type Options struct {
@@ -13,6 +25,7 @@ type Options struct {
 	VerifyIR      bool
 	Debug         bool
 	PrintSizes    string
+	PrintStacks   bool
 	CFlags        []string
 	LDFlags       []string
 	Tags          string
@@ -21,3 +34,53 @@ type Options struct {
 	TestConfig    TestConfig
 	Programmer    string
 }
+
+// Verify performs a validation on the given options, raising an error if options are not valid.
+func (o *Options) Verify() error {
+	if o.GC != "" {
+		valid := isInArray(validGCOptions, o.GC)
+		if !valid {
+			return fmt.Errorf(`invalid gc option '%s': valid values are %s`,
+				o.GC,
+				strings.Join(validGCOptions, ", "))
+		}
+	}
+
+	if o.Scheduler != "" {
+		valid := isInArray(validSchedulerOptions, o.Scheduler)
+		if !valid {
+			return fmt.Errorf(`invalid scheduler option '%s': valid values are %s`,
+				o.Scheduler,
+				strings.Join(validSchedulerOptions, ", "))
+		}
+	}
+
+	if o.PrintSizes != "" {
+		valid := isInArray(validPrintSizeOptions, o.PrintSizes)
+		if !valid {
+			return fmt.Errorf(`invalid size option '%s': valid values are %s`,
+				o.PrintSizes,
+				strings.Join(validPrintSizeOptions, ", "))
+		}
+	}
+
+	if o.PanicStrategy != "" {
+		valid := isInArray(validPanicStrategyOptions, o.PanicStrategy)
+		if !valid {
+			return fmt.Errorf(`invalid panic option '%s': valid values are %s`,
+				o.PanicStrategy,
+				strings.Join(validPanicStrategyOptions, ", "))
+		}
+	}
+
+	return nil
+}
+
+func isInArray(arr []string, item string) bool {
+	for _, i := range arr {
+		if i == item {
+			return true
+		}
+	}
+	return false
+}

compileopts/options_test.go

@@ -0,0 +1,138 @@
+package compileopts_test
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+)
+
+func TestVerifyOptions(t *testing.T) {
+
+	expectedGCError := errors.New(`invalid gc option 'incorrect': valid values are none, leaking, extalloc, conservative`)
+	expectedSchedulerError := errors.New(`invalid scheduler option 'incorrect': valid values are none, tasks, coroutines`)
+	expectedPrintSizeError := errors.New(`invalid size option 'incorrect': valid values are none, short, full`)
+	expectedPanicStrategyError := errors.New(`invalid panic option 'incorrect': valid values are print, trap`)
+
+	testCases := []struct {
+		name          string
+		opts          compileopts.Options
+		expectedError error
+	}{
+		{
+			name: "OptionsEmpty",
+			opts: compileopts.Options{},
+		},
+		{
+			name: "InvalidGCOption",
+			opts: compileopts.Options{
+				GC: "incorrect",
+			},
+			expectedError: expectedGCError,
+		},
+		{
+			name: "GCOptionNone",
+			opts: compileopts.Options{
+				GC: "none",
+			},
+		},
+		{
+			name: "GCOptionLeaking",
+			opts: compileopts.Options{
+				GC: "leaking",
+			},
+		},
+		{
+			name: "GCOptionExtalloc",
+			opts: compileopts.Options{
+				GC: "extalloc",
+			},
+		},
+		{
+			name: "GCOptionConservative",
+			opts: compileopts.Options{
+				GC: "conservative",
+			},
+		},
+		{
+			name: "InvalidSchedulerOption",
+			opts: compileopts.Options{
+				Scheduler: "incorrect",
+			},
+			expectedError: expectedSchedulerError,
+		},
+		{
+			name: "SchedulerOptionNone",
+			opts: compileopts.Options{
+				Scheduler: "none",
+			},
+		},
+		{
+			name: "SchedulerOptionTasks",
+			opts: compileopts.Options{
+				Scheduler: "tasks",
+			},
+		},
+		{
+			name: "SchedulerOptionCoroutines",
+			opts: compileopts.Options{
+				Scheduler: "coroutines",
+			},
+		},
+		{
+			name: "InvalidPrintSizeOption",
+			opts: compileopts.Options{
+				PrintSizes: "incorrect",
+			},
+			expectedError: expectedPrintSizeError,
+		},
+		{
+			name: "PrintSizeOptionNone",
+			opts: compileopts.Options{
+				PrintSizes: "none",
+			},
+		},
+		{
+			name: "PrintSizeOptionShort",
+			opts: compileopts.Options{
+				PrintSizes: "short",
+			},
+		},
+		{
+			name: "PrintSizeOptionFull",
+			opts: compileopts.Options{
+				PrintSizes: "full",
+			},
+		},
+		{
+			name: "InvalidPanicOption",
+			opts: compileopts.Options{
+				PanicStrategy: "incorrect",
+			},
+			expectedError: expectedPanicStrategyError,
+		},
+		{
+			name: "PanicOptionPrint",
+			opts: compileopts.Options{
+				PanicStrategy: "print",
+			},
+		},
+		{
+			name: "PanicOptionTrap",
+			opts: compileopts.Options{
+				PanicStrategy: "trap",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := tc.opts.Verify()
+			if tc.expectedError != err {
+				if tc.expectedError.Error() != err.Error() {
+					t.Errorf("expected %v, got %v", tc.expectedError, err)
+				}
+			}
+		})
+	}
+}

compileopts/target.go

@@ -33,6 +33,8 @@ type TargetSpec struct {
 	Linker           string   `json:"linker"`
 	RTLib            string   `json:"rtlib"` // compiler runtime library (libgcc, compiler-rt)
 	Libc             string   `json:"libc"`
+	AutoStackSize    *bool    `json:"automatic-stack-size"` // Determine stack size automatically at compile time.
+	DefaultStackSize uint64   `json:"default-stack-size"`   // Default stack size if the size couldn't be determined at compile time.
 	CFlags           []string `json:"cflags"`
 	LDFlags          []string `json:"ldflags"`
 	LinkerScript     string   `json:"linkerscript"`
@@ -45,10 +47,13 @@ type TargetSpec struct {
 	FlashVolume      string   `json:"msd-volume-name"`
 	FlashFilename    string   `json:"msd-firmware-name"`
 	UF2FamilyID      string   `json:"uf2-family-id"`
+	BinaryFormat     string   `json:"binary-format"`
 	OpenOCDInterface string   `json:"openocd-interface"`
 	OpenOCDTarget    string   `json:"openocd-target"`
 	OpenOCDTransport string   `json:"openocd-transport"`
 	JLinkDevice      string   `json:"jlink-device"`
+	CodeModel        string   `json:"code-model"`
+	RelocationModel  string   `json:"relocation-model"`
 }
 
 // copyProperties copies all properties that are set in spec2 into itself.
@@ -88,6 +93,12 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	if spec2.Libc != "" {
 		spec.Libc = spec2.Libc
 	}
+	if spec2.AutoStackSize != nil {
+		spec.AutoStackSize = spec2.AutoStackSize
+	}
+	if spec2.DefaultStackSize != 0 {
+		spec.DefaultStackSize = spec2.DefaultStackSize
+	}
 	spec.CFlags = append(spec.CFlags, spec2.CFlags...)
 	spec.LDFlags = append(spec.LDFlags, spec2.LDFlags...)
 	if spec2.LinkerScript != "" {
@@ -118,6 +129,9 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	if spec2.UF2FamilyID != "" {
 		spec.UF2FamilyID = spec2.UF2FamilyID
 	}
+	if spec2.BinaryFormat != "" {
+		spec.BinaryFormat = spec2.BinaryFormat
+	}
 	if spec2.OpenOCDInterface != "" {
 		spec.OpenOCDInterface = spec2.OpenOCDInterface
 	}
@@ -130,6 +144,13 @@ func (spec *TargetSpec) copyProperties(spec2 *TargetSpec) {
 	if spec2.JLinkDevice != "" {
 		spec.JLinkDevice = spec2.JLinkDevice
 	}
+	if spec2.CodeModel != "" {
+		spec.CodeModel = spec2.CodeModel
+	}
+
+	if spec2.RelocationModel != "" {
+		spec.RelocationModel = spec2.RelocationModel
+	}
 }
 
 // load reads a target specification from the JSON in the given io.Reader. It

compiler/atomic.go

@@ -0,0 +1,57 @@
+package compiler
+
+import (
+	"golang.org/x/tools/go/ssa"
+	"tinygo.org/x/go-llvm"
+)
+
+// createAtomicOp lowers an atomic library call by lowering it as an LLVM atomic
+// operation. It returns the result of the operation and true if the call could
+// be lowered inline, and false otherwise.
+func (b *builder) createAtomicOp(call *ssa.CallCommon) (llvm.Value, bool) {
+	name := call.Value.(*ssa.Function).Name()
+	switch name {
+	case "AddInt32", "AddInt64", "AddUint32", "AddUint64", "AddUintptr":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpAdd, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
+		// Return the new value, not the original value returned by atomicrmw.
+		return b.CreateAdd(oldVal, val, ""), true
+	case "SwapInt32", "SwapInt64", "SwapUint32", "SwapUint64", "SwapUintptr", "SwapPointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		isPointer := val.Type().TypeKind() == llvm.PointerTypeKind
+		if isPointer {
+			// atomicrmw only supports integers, so cast to an integer.
+			val = b.CreatePtrToInt(val, b.uintptrType, "")
+			ptr = b.CreateBitCast(ptr, llvm.PointerType(val.Type(), 0), "")
+		}
+		oldVal := b.CreateAtomicRMW(llvm.AtomicRMWBinOpXchg, ptr, val, llvm.AtomicOrderingSequentiallyConsistent, true)
+		if isPointer {
+			oldVal = b.CreateIntToPtr(oldVal, b.i8ptrType, "")
+		}
+		return oldVal, true
+	case "CompareAndSwapInt32", "CompareAndSwapInt64", "CompareAndSwapUint32", "CompareAndSwapUint64", "CompareAndSwapUintptr", "CompareAndSwapPointer":
+		ptr := b.getValue(call.Args[0])
+		old := b.getValue(call.Args[1])
+		newVal := b.getValue(call.Args[2])
+		tuple := b.CreateAtomicCmpXchg(ptr, old, newVal, llvm.AtomicOrderingSequentiallyConsistent, llvm.AtomicOrderingSequentiallyConsistent, true)
+		swapped := b.CreateExtractValue(tuple, 1, "")
+		return swapped, true
+	case "LoadInt32", "LoadInt64", "LoadUint32", "LoadUint64", "LoadUintptr", "LoadPointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.CreateLoad(ptr, "")
+		val.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
+		val.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
+		return val, true
+	case "StoreInt32", "StoreInt64", "StoreUint32", "StoreUint64", "StoreUintptr", "StorePointer":
+		ptr := b.getValue(call.Args[0])
+		val := b.getValue(call.Args[1])
+		store := b.CreateStore(val, ptr)
+		store.SetOrdering(llvm.AtomicOrderingSequentiallyConsistent)
+		store.SetAlignment(b.targetData.PrefTypeAlignment(val.Type())) // required
+		return store, true
+	default:
+		return llvm.Value{}, false
+	}
+}

compiler/channel.go

@@ -12,7 +12,7 @@ import (
 )
 
 func (b *builder) createMakeChan(expr *ssa.MakeChan) llvm.Value {
-	elementSize := b.targetData.TypeAllocSize(b.getLLVMType(expr.Type().(*types.Chan).Elem()))
+	elementSize := b.targetData.TypeAllocSize(b.getLLVMType(expr.Type().Underlying().(*types.Chan).Elem()))
 	elementSizeValue := llvm.ConstInt(b.uintptrType, elementSize, false)
 	bufSize := b.getValue(expr.Size)
 	b.createChanBoundsCheck(elementSize, bufSize, expr.Size.Type().Underlying().(*types.Basic), expr.Pos())
@@ -35,27 +35,37 @@ func (b *builder) createChanSend(instr *ssa.Send) {
 	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")
 	b.CreateStore(chanValue, valueAlloca)
 
-	// Do the send.
+	// Allocate blockedlist buffer.
-	b.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast}, "")
+	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
+	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
 
-	// End the lifetime of the alloca.
+	// Do the send.
+	b.createRuntimeCall("chanSend", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
+
+	// End the lifetime of the allocas.
 	// This also works around a bug in CoroSplit, at least in LLVM 8:
 	// https://bugs.llvm.org/show_bug.cgi?id=41742
+	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
 	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
 }
 
 // createChanRecv emits a pseudo chan receive operation. It is lowered to the
 // actual channel receive operation during goroutine lowering.
 func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
-	valueType := b.getLLVMType(unop.X.Type().(*types.Chan).Elem())
+	valueType := b.getLLVMType(unop.X.Type().Underlying().(*types.Chan).Elem())
 	ch := b.getValue(unop.X)
 
 	// Allocate memory to receive into.
 	valueAlloca, valueAllocaCast, valueAllocaSize := b.createTemporaryAlloca(valueType, "chan.value")
 
+	// Allocate blockedlist buffer.
+	channelBlockedList := b.mod.GetTypeByName("runtime.channelBlockedList")
+	channelBlockedListAlloca, channelBlockedListAllocaCast, channelBlockedListAllocaSize := b.createTemporaryAlloca(channelBlockedList, "chan.blockedList")
+
 	// Do the receive.
-	commaOk := b.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast}, "")
+	commaOk := b.createRuntimeCall("chanRecv", []llvm.Value{ch, valueAllocaCast, channelBlockedListAlloca}, "")
 	received := b.CreateLoad(valueAlloca, "chan.received")
+	b.emitLifetimeEnd(channelBlockedListAllocaCast, channelBlockedListAllocaSize)
 	b.emitLifetimeEnd(valueAllocaCast, valueAllocaSize)
 
 	if unop.CommaOk {
@@ -117,7 +127,7 @@ func (b *builder) createSelect(expr *ssa.Select) llvm.Value {
 		switch state.Dir {
 		case types.RecvOnly:
 			// Make sure the receive buffer is big enough and has the correct alignment.
-			llvmType := b.getLLVMType(state.Chan.Type().(*types.Chan).Elem())
+			llvmType := b.getLLVMType(state.Chan.Type().Underlying().(*types.Chan).Elem())
 			if size := b.targetData.TypeAllocSize(llvmType); size > recvbufSize {
 				recvbufSize = size
 			}

compiler/compiler.go

@@ -5,18 +5,15 @@ import (
 	"errors"
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/constant"
 	"go/token"
 	"go/types"
-	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
 
 	"github.com/tinygo-org/tinygo/compileopts"
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
-	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/ir"
 	"github.com/tinygo-org/tinygo/loader"
 	"golang.org/x/tools/go/ssa"
@@ -74,7 +71,14 @@ type builder struct {
 	deferFuncs        map[*ir.Function]int
 	deferInvokeFuncs  map[string]int
 	deferClosureFuncs map[*ir.Function]int
+	deferExprFuncs    map[ssa.Value]int
 	selectRecvBuf     map[*ssa.Select]llvm.Value
+	deferBuiltinFuncs map[ssa.Value]deferBuiltin
+}
+
+type deferBuiltin struct {
+	funcName string
+	callback int
 }
 
 type phiNode struct {
@@ -91,10 +95,60 @@ func NewTargetMachine(config *compileopts.Config) (llvm.TargetMachine, error) {
 		return llvm.TargetMachine{}, err
 	}
 	features := strings.Join(config.Features(), ",")
-	machine := target.CreateTargetMachine(config.Triple(), config.CPU(), features, llvm.CodeGenLevelDefault, llvm.RelocStatic, llvm.CodeModelDefault)
+
+	var codeModel llvm.CodeModel
+	var relocationModel llvm.RelocMode
+
+	switch config.CodeModel() {
+	case "default":
+		codeModel = llvm.CodeModelDefault
+	case "tiny":
+		codeModel = llvm.CodeModelTiny
+	case "small":
+		codeModel = llvm.CodeModelSmall
+	case "kernel":
+		codeModel = llvm.CodeModelKernel
+	case "medium":
+		codeModel = llvm.CodeModelMedium
+	case "large":
+		codeModel = llvm.CodeModelLarge
+	}
+
+	switch config.RelocationModel() {
+	case "static":
+		relocationModel = llvm.RelocStatic
+	case "pic":
+		relocationModel = llvm.RelocPIC
+	case "dynamicnopic":
+		relocationModel = llvm.RelocDynamicNoPic
+	}
+
+	machine := target.CreateTargetMachine(config.Triple(), config.CPU(), features, llvm.CodeGenLevelDefault, relocationModel, codeModel)
 	return machine, nil
 }
 
+// CompilerOutput is returned from the Compile() call. It contains the compile
+// output and information necessary to continue to compile and link the program.
+type CompilerOutput struct {
+	// The LLVM module that contains the compiled but not optimized LLVM module
+	// for all the Go code in the program.
+	Mod llvm.Module
+
+	// ExtraFiles is a list of C source files included in packages that should
+	// be built and linked together with the main executable to form one
+	// program. They can be used from CGo, for example.
+	ExtraFiles []string
+
+	// ExtraLDFlags are linker flags obtained during CGo processing. These flags
+	// must be passed to the linker which links the entire executable.
+	ExtraLDFlags []string
+
+	// MainDir is the absolute directory path to the directory of the main
+	// package. This is useful for testing: tests must be run in the package
+	// directory that is being tested.
+	MainDir string
+}
+
 // Compile the given package path or .go file path. Return an error when this
 // fails (in any stage). If successful it returns the LLVM module and a list of
 // extra C files to be compiled. If not, one or more errors will be returned.
@@ -103,7 +157,7 @@ func NewTargetMachine(config *compileopts.Config) (llvm.TargetMachine, error) {
 // violation. Eventually, this Compile function should only compile a single
 // package and not the whole program, and loading of the program (including CGo
 // processing) should be moved outside the compiler package.
-func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Config) (llvm.Module, []string, []error) {
+func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Config) (output CompilerOutput, errors []error) {
 	c := &compilerContext{
 		Config:     config,
 		difiles:    make(map[string]llvm.Metadata),
@@ -119,6 +173,7 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	if c.Debug() {
 		c.dibuilder = llvm.NewDIBuilder(c.mod)
 	}
+	output.Mod = c.mod
 
 	c.uintptrType = c.ctx.IntType(c.targetData.PointerSize() * 8)
 	if c.targetData.PointerSize() <= 4 {
@@ -137,109 +192,29 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	c.funcPtrAddrSpace = dummyFunc.Type().PointerAddressSpace()
 	dummyFunc.EraseFromParentAsFunction()
 
-	// Prefix the GOPATH with the system GOROOT, as GOROOT is already set to
+	lprogram, err := loader.Load(c.Config, []string{pkgName}, c.ClangHeaders, types.Config{
-	// the TinyGo root.
+		Sizes: &stdSizes{
-	overlayGopath := goenv.Get("GOPATH")
+			IntSize:  int64(c.targetData.TypeAllocSize(c.intType)),
-	if overlayGopath == "" {
+			PtrSize:  int64(c.targetData.PointerSize()),
-		overlayGopath = goenv.Get("GOROOT")
+			MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
-	} else {
+		}})
-		overlayGopath = goenv.Get("GOROOT") + string(filepath.ListSeparator) + overlayGopath
-	}
-
-	wd, err := os.Getwd()
 	if err != nil {
-		return c.mod, nil, []error{err}
+		return output, []error{err}
-	}
-	lprogram := &loader.Program{
-		Build: &build.Context{
-			GOARCH:      c.GOARCH(),
-			GOOS:        c.GOOS(),
-			GOROOT:      goenv.Get("GOROOT"),
-			GOPATH:      goenv.Get("GOPATH"),
-			CgoEnabled:  c.CgoEnabled(),
-			UseAllFiles: false,
-			Compiler:    "gc", // must be one of the recognized compilers
-			BuildTags:   c.BuildTags(),
-		},
-		OverlayBuild: &build.Context{
-			GOARCH:      c.GOARCH(),
-			GOOS:        c.GOOS(),
-			GOROOT:      goenv.Get("TINYGOROOT"),
-			GOPATH:      overlayGopath,
-			CgoEnabled:  c.CgoEnabled(),
-			UseAllFiles: false,
-			Compiler:    "gc", // must be one of the recognized compilers
-			BuildTags:   c.BuildTags(),
-		},
-		OverlayPath: func(path string) string {
-			// Return the (overlay) import path when it should be overlaid, and
-			// "" if it should not.
-			if strings.HasPrefix(path, tinygoPath+"/src/") {
-				// Avoid issues with packages that are imported twice, one from
-				// GOPATH and one from TINYGOPATH.
-				path = path[len(tinygoPath+"/src/"):]
-			}
-			switch path {
-			case "machine", "os", "reflect", "runtime", "runtime/interrupt", "runtime/volatile", "sync", "testing", "internal/reflectlite", "internal/task":
-				return path
-			default:
-				if strings.HasPrefix(path, "device/") || strings.HasPrefix(path, "examples/") {
-					return path
-				} else if path == "syscall" {
-					for _, tag := range c.BuildTags() {
-						if tag == "baremetal" || tag == "darwin" {
-							return path
-						}
-					}
-				}
-			}
-			return ""
-		},
-		TypeChecker: types.Config{
-			Sizes: &stdSizes{
-				IntSize:  int64(c.targetData.TypeAllocSize(c.intType)),
-				PtrSize:  int64(c.targetData.PointerSize()),
-				MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
-			},
-		},
-		Dir:          wd,
-		TINYGOROOT:   goenv.Get("TINYGOROOT"),
-		CFlags:       c.CFlags(),
-		ClangHeaders: c.ClangHeaders,
 	}
 
-	if strings.HasSuffix(pkgName, ".go") {
+	err = lprogram.Parse()
-		_, err = lprogram.ImportFile(pkgName)
-		if err != nil {
-			return c.mod, nil, []error{err}
-		}
-	} else {
-		_, err = lprogram.Import(pkgName, wd, token.Position{
-			Filename: "build command-line-arguments",
-		})
-		if err != nil {
-			return c.mod, nil, []error{err}
-		}
-	}
-
-	_, err = lprogram.Import("runtime", "", token.Position{
-		Filename: "build default import",
-	})
 	if err != nil {
-		return c.mod, nil, []error{err}
+		return output, []error{err}
 	}
+	output.ExtraLDFlags = lprogram.LDFlags
+	output.MainDir = lprogram.MainPkg().Dir
 
-	err = lprogram.Parse(c.TestConfig.CompileTestBinary)
+	c.ir = ir.NewProgram(lprogram)
-	if err != nil {
-		return c.mod, nil, []error{err}
-	}
-
-	c.ir = ir.NewProgram(lprogram, pkgName)
 
 	// Run a simple dead code elimination pass.
 	err = c.ir.SimpleDCE()
 	if err != nil {
-		return c.mod, nil, []error{err}
+		return output, []error{err}
 	}
 
 	// Initialize debug information.
@@ -312,6 +287,8 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 		pos := c.ir.Program.Fset.Position(initFn.Pos())
 		irbuilder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
 	}
+	initFn.LLVMFn.Param(0).SetName("context")
+	initFn.LLVMFn.Param(1).SetName("parentHandle")
 	block := c.ctx.AddBasicBlock(initFn.LLVMFn, "entry")
 	irbuilder.SetInsertPointAtEnd(block)
 	for _, fn := range initFuncs {
@@ -376,14 +353,13 @@ func Compile(pkgName string, machine llvm.TargetMachine, config *compileopts.Con
 	}
 
 	// Gather the list of (C) file paths that should be included in the build.
-	var extraFiles []string
 	for _, pkg := range c.ir.LoaderProgram.Sorted() {
-		for _, file := range pkg.CFiles {
+		for _, filename := range pkg.CFiles {
-			extraFiles = append(extraFiles, filepath.Join(pkg.Package.Dir, file))
+			output.ExtraFiles = append(output.ExtraFiles, filepath.Join(pkg.Dir, filename))
 		}
 	}
 
-	return c.mod, extraFiles, c.diagnostics
+	return output, c.diagnostics
 }
 
 // getLLVMRuntimeType obtains a named type from the runtime package and returns
@@ -1104,7 +1080,7 @@ func (b *builder) createInstruction(instr ssa.Instruction) {
 			// goroutine:
 			//   * The function context, for closures.
 			//   * The function pointer (for tasks).
-			funcPtr, context := b.decodeFuncValue(b.getValue(instr.Call.Value), instr.Call.Value.Type().(*types.Signature))
+			funcPtr, context := b.decodeFuncValue(b.getValue(instr.Call.Value), instr.Call.Value.Type().Underlying().(*types.Signature))
 			params = append(params, context) // context parameter
 			switch b.Scheduler() {
 			case "none", "coroutines":
@@ -1201,9 +1177,7 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		var llvmCap llvm.Value
 		switch args[0].Type().(type) {
 		case *types.Chan:
-			// Channel. Buffered channels haven't been implemented yet so always
+			llvmCap = b.createRuntimeCall("chanCap", []llvm.Value{value}, "cap")
-			// return 0.
-			llvmCap = llvm.ConstInt(b.intType, 0, false)
 		case *types.Slice:
 			llvmCap = b.CreateExtractValue(value, 2, "cap")
 		default:
@@ -1259,9 +1233,7 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 			// string or slice
 			llvmLen = b.CreateExtractValue(value, 1, "len")
 		case *types.Chan:
-			// Channel. Buffered channels haven't been implemented yet so always
+			llvmLen = b.createRuntimeCall("chanLen", []llvm.Value{value}, "len")
-			// return 0.
-			llvmLen = llvm.ConstInt(b.intType, 0, false)
 		case *types.Map:
 			llvmLen = b.createRuntimeCall("hashmapLen", []llvm.Value{value}, "len")
 		default:
@@ -1364,9 +1336,9 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.createMemoryCopyCall(fn, instr.Args)
 		case name == "runtime.memzero":
 			return b.createMemoryZeroCall(instr.Args)
-		case name == "device/arm.Asm" || name == "device/avr.Asm" || name == "device/riscv.Asm":
+		case name == "device.Asm" || name == "device/arm.Asm" || name == "device/avr.Asm" || name == "device/riscv.Asm":
 			return b.createInlineAsm(instr.Args)
-		case name == "device/arm.AsmFull" || name == "device/avr.AsmFull" || name == "device/riscv.AsmFull":
+		case name == "device.AsmFull" || name == "device/arm.AsmFull" || name == "device/avr.AsmFull" || name == "device/riscv.AsmFull":
 			return b.createInlineAsmFull(instr)
 		case strings.HasPrefix(name, "device/arm.SVCall"):
 			return b.emitSVCall(instr.Args)
@@ -1378,6 +1350,14 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.createVolatileLoad(instr)
 		case strings.HasPrefix(name, "runtime/volatile.Store"):
 			return b.createVolatileStore(instr)
+		case strings.HasPrefix(name, "sync/atomic."):
+			val, ok := b.createAtomicOp(instr)
+			if ok {
+				// This call could be lowered as an atomic operation.
+				return val, nil
+			}
+			// This call couldn't be lowered as an atomic operation, it's
+			// probably something else. Continue as usual.
 		case name == "runtime/interrupt.New":
 			return b.createInterruptGlobal(instr)
 		}
@@ -1571,7 +1551,7 @@ func (b *builder) createExpr(expr ssa.Value) (llvm.Value, error) {
 		index := b.getValue(expr.Index)
 
 		// Check bounds.
-		arrayLen := expr.X.Type().(*types.Array).Len()
+		arrayLen := expr.X.Type().Underlying().(*types.Array).Len()
 		arrayLenLLVM := llvm.ConstInt(b.uintptrType, uint64(arrayLen), false)
 		b.createLookupBoundsCheck(arrayLenLLVM, index, expr.Index.Type())
 
@@ -1683,8 +1663,8 @@ func (b *builder) createExpr(expr ssa.Value) (llvm.Value, error) {
 		}
 
 		// Bounds checking.
-		lenType := expr.Len.Type().(*types.Basic)
+		lenType := expr.Len.Type().Underlying().(*types.Basic)
-		capType := expr.Cap.Type().(*types.Basic)
+		capType := expr.Cap.Type().Underlying().(*types.Basic)
 		b.createSliceBoundsCheck(maxSize, sliceLen, sliceCap, sliceCap, lenType, capType, capType)
 
 		// Allocate the backing array.
@@ -2565,7 +2545,7 @@ func (b *builder) createConvert(typeFrom, typeTo types.Type, value llvm.Value, p
 		return llvm.Value{}, b.makeError(pos, "todo: convert: basic non-integer type: "+typeFrom.String()+" -> "+typeTo.String())
 
 	case *types.Slice:
-		if basic, ok := typeFrom.(*types.Basic); !ok || basic.Info()&types.IsString == 0 {
+		if basic, ok := typeFrom.Underlying().(*types.Basic); !ok || basic.Info()&types.IsString == 0 {
 			panic("can only convert from a string to a slice")
 		}
 

compiler/defer.go

@@ -16,6 +16,7 @@ package compiler
 import (
 	"github.com/tinygo-org/tinygo/compiler/llvmutil"
 	"github.com/tinygo-org/tinygo/ir"
+	"go/types"
 	"golang.org/x/tools/go/ssa"
 	"tinygo.org/x/go-llvm"
 )
@@ -28,6 +29,8 @@ func (b *builder) deferInitFunc() {
 	b.deferFuncs = make(map[*ir.Function]int)
 	b.deferInvokeFuncs = make(map[string]int)
 	b.deferClosureFuncs = make(map[*ir.Function]int)
+	b.deferExprFuncs = make(map[ssa.Value]int)
+	b.deferBuiltinFuncs = make(map[ssa.Value]deferBuiltin)
 
 	// Create defer list pointer.
 	deferType := llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)
@@ -151,9 +154,54 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		values = append(values, context)
 		valueTypes = append(valueTypes, context.Type())
 
+	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
+		var funcName string
+		switch builtin.Name() {
+		case "close":
+			funcName = "chanClose"
+		default:
+			b.addError(instr.Pos(), "todo: Implement defer for "+builtin.Name())
+			return
+		}
+
+		if _, ok := b.deferBuiltinFuncs[instr.Call.Value]; !ok {
+			b.deferBuiltinFuncs[instr.Call.Value] = deferBuiltin{
+				funcName,
+				len(b.allDeferFuncs),
+			}
+			b.allDeferFuncs = append(b.allDeferFuncs, instr.Call.Value)
+		}
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferBuiltinFuncs[instr.Call.Value].callback), false)
+
+		// Collect all values to be put in the struct (starting with
+		// runtime._defer fields).
+		values = []llvm.Value{callback, next}
+		for _, param := range instr.Call.Args {
+			llvmParam := b.getValue(param)
+			values = append(values, llvmParam)
+			valueTypes = append(valueTypes, llvmParam.Type())
+		}
+
 	} else {
-		b.addError(instr.Pos(), "todo: defer on uncommon function call type")
+		funcValue := b.getValue(instr.Call.Value)
-		return
+
+		if _, ok := b.deferExprFuncs[instr.Call.Value]; !ok {
+			b.deferExprFuncs[instr.Call.Value] = len(b.allDeferFuncs)
+			b.allDeferFuncs = append(b.allDeferFuncs, &instr.Call)
+		}
+
+		callback := llvm.ConstInt(b.uintptrType, uint64(b.deferExprFuncs[instr.Call.Value]), false)
+
+		// Collect all values to be put in the struct (starting with
+		// runtime._defer fields, followed by all parameters including the
+		// context pointer).
+		values = []llvm.Value{callback, next, funcValue}
+		valueTypes = append(valueTypes, funcValue.Type())
+		for _, param := range instr.Call.Args {
+			llvmParam := b.getValue(param)
+			values = append(values, llvmParam)
+			valueTypes = append(valueTypes, llvmParam.Type())
+		}
 	}
 
 	// Make a struct out of the collected values to put in the defer frame.
@@ -243,16 +291,23 @@ func (b *builder) createRunDefers() {
 		b.SetInsertPointAtEnd(block)
 		switch callback := callback.(type) {
 		case *ssa.CallCommon:
-			// Call on an interface value.
+			// Call on an value or interface value.
-			if !callback.IsInvoke() {
-				panic("expected an invoke call, not a direct call")
-			}
 
 			// Get the real defer struct type and cast to it.
-			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0), b.uintptrType, b.i8ptrType}
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
+
+			if !callback.IsInvoke() {
+				//Expect funcValue to be passed through the defer frame.
+				valueTypes = append(valueTypes, b.getFuncType(callback.Signature()))
+			} else {
+				//Expect typecode
+				valueTypes = append(valueTypes, b.uintptrType, b.i8ptrType)
+			}
+
 			for _, arg := range callback.Args {
 				valueTypes = append(valueTypes, b.getLLVMType(arg.Type()))
 			}
+
 			deferFrameType := b.ctx.StructType(valueTypes, false)
 			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
@@ -265,18 +320,34 @@ func (b *builder) createRunDefers() {
 				forwardParams = append(forwardParams, forwardParam)
 			}
 
-			// Isolate the typecode.
+			var fnPtr llvm.Value
-			typecode, forwardParams := forwardParams[0], forwardParams[1:]
 
-			// Add the context parameter. An interface call cannot also be a
+			if !callback.IsInvoke() {
-			// closure but we have to supply the parameter anyway for platforms
+				// Isolate the func value.
-			// with a strict calling convention.
+				funcValue := forwardParams[0]
-			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
+				forwardParams = forwardParams[1:]
+
+				//Get function pointer and context
+				fp, context := b.decodeFuncValue(funcValue, callback.Signature())
+				fnPtr = fp
+
+				//Pass context
+				forwardParams = append(forwardParams, context)
+			} else {
+				// Isolate the typecode.
+				typecode := forwardParams[0]
+				forwardParams = forwardParams[1:]
+				fnPtr = b.getInvokePtr(callback, typecode)
+
+				// Add the context parameter. An interface call cannot also be a
+				// closure but we have to supply the parameter anyway for platforms
+				// with a strict calling convention.
+				forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
+			}
 
 			// Parent coroutine handle.
 			forwardParams = append(forwardParams, llvm.Undef(b.i8ptrType))
 
-			fnPtr := b.getInvokePtr(callback, typecode)
 			b.createCall(fnPtr, forwardParams, "")
 
 		case *ir.Function:
@@ -339,7 +410,31 @@ func (b *builder) createRunDefers() {
 
 			// Call deferred function.
 			b.createCall(fn.LLVMFn, forwardParams, "")
+		case *ssa.Builtin:
+			db := b.deferBuiltinFuncs[callback]
 
+			//Get parameter types
+			valueTypes := []llvm.Type{b.uintptrType, llvm.PointerType(b.getLLVMRuntimeType("_defer"), 0)}
+
+			//Get signature from call results
+			params := callback.Type().Underlying().(*types.Signature).Params()
+			for i := 0; i < params.Len(); i++ {
+				valueTypes = append(valueTypes, b.getLLVMType(params.At(i).Type()))
+			}
+
+			deferFrameType := b.ctx.StructType(valueTypes, false)
+			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
+
+			// Extract the params from the struct.
+			var forwardParams []llvm.Value
+			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
+			for i := 0; i < params.Len(); i++ {
+				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
+				forwardParam := b.CreateLoad(gep, "param")
+				forwardParams = append(forwardParams, forwardParam)
+			}
+
+			b.createRuntimeCall(db.funcName, forwardParams, "")
 		default:
 			panic("unknown deferred function type")
 		}

compiler/goroutine.go

@@ -19,16 +19,30 @@ import (
 // Because a go statement doesn't return anything, return undef.
 func (b *builder) createGoInstruction(funcPtr llvm.Value, params []llvm.Value, prefix string, pos token.Pos) llvm.Value {
 	paramBundle := b.emitPointerPack(params)
-	var callee llvm.Value
+	var callee, stackSize llvm.Value
 	switch b.Scheduler() {
 	case "none", "tasks":
 		callee = b.createGoroutineStartWrapper(funcPtr, prefix, pos)
+		if b.AutomaticStackSize() {
+			// The stack size is not known until after linking. Call a dummy
+			// function that will be replaced with a load from a special ELF
+			// section that contains the stack size (and is modified after
+			// linking).
+			stackSize = b.createCall(b.mod.NamedFunction("internal/task.getGoroutineStackSize"), []llvm.Value{callee, llvm.Undef(b.i8ptrType), llvm.Undef(b.i8ptrType)}, "stacksize")
+		} else {
+			// The stack size is fixed at compile time. By emitting it here as a
+			// constant, it can be optimized.
+			stackSize = llvm.ConstInt(b.uintptrType, b.Target.DefaultStackSize, false)
+		}
 	case "coroutines":
 		callee = b.CreatePtrToInt(funcPtr, b.uintptrType, "")
+		// There is no goroutine stack size: coroutines are used instead of
+		// stacks.
+		stackSize = llvm.Undef(b.uintptrType)
 	default:
 		panic("unreachable")
 	}
-	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
+	b.createCall(b.mod.NamedFunction("internal/task.start"), []llvm.Value{callee, paramBundle, stackSize, llvm.Undef(b.i8ptrType), llvm.ConstPointerNull(b.i8ptrType)}, "")
 	return llvm.Undef(funcPtr.Type().ElementType().ReturnType())
 }
 
@@ -67,8 +81,9 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		// Create the wrapper.
 		wrapperType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{c.i8ptrType}, false)
 		wrapper = llvm.AddFunction(c.mod, name+"$gowrapper", wrapperType)
-		wrapper.SetLinkage(llvm.PrivateLinkage)
+		wrapper.SetLinkage(llvm.InternalLinkage)
 		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", name))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)
 
@@ -125,6 +140,7 @@ func (c *compilerContext) createGoroutineStartWrapper(fn llvm.Value, prefix stri
 		wrapper = llvm.AddFunction(c.mod, prefix+".gowrapper", wrapperType)
 		wrapper.SetLinkage(llvm.InternalLinkage)
 		wrapper.SetUnnamedAddr(true)
+		wrapper.AddAttributeAtIndex(-1, c.ctx.CreateStringAttribute("tinygo-gowrapper", ""))
 		entry := c.ctx.AddBasicBlock(wrapper, "entry")
 		builder.SetInsertPointAtEnd(entry)
 

go.mod

@@ -4,10 +4,11 @@ go 1.11
 
 require (
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
+	github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac
+	github.com/chromedp/chromedp v0.5.3
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
-	github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46
+	github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892
 	go.bug.st/serial v1.0.0
 	golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2
-	google.golang.org/appengine v1.4.0 // indirect
+	tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d
-	tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a
 )

go.sum

@@ -1,13 +1,26 @@
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
+github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac h1:T7V5BXqnYd55Hj/g5uhDYumg9Fp3rMTS6bykYtTIFX4=
+github.com/chromedp/cdproto v0.0.0-20200116234248-4da64dd111ac/go.mod h1:PfAWWKJqjlGFYJEidUM6aVIWPr0EpobeyVWEEmplX7g=
+github.com/chromedp/chromedp v0.5.3 h1:F9LafxmYpsQhWQBdCs+6Sret1zzeeFyHS5LkRF//Ffg=
+github.com/chromedp/chromedp v0.5.3/go.mod h1:YLdPtndaHQ4rCpSpBG+IPpy9JvX0VD+7aaLxYgYj28w=
 github.com/creack/goselect v0.1.1 h1:tiSSgKE1eJtxs1h/VgGQWuXUP0YS4CDIFMp6vaI1ls0=
 github.com/creack/goselect v0.1.1/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee h1:s+21KNqlpePfkah2I+gwHF8xmJWRjooY+5248k6m4A0=
+github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
+github.com/gobwas/pool v0.2.0 h1:QEmUOlnSjWtnpRGHF3SauEiOsy82Cup83Vf2LcMlnc8=
+github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
+github.com/gobwas/ws v1.0.2 h1:CoAavW/wd/kulfZmSIBt6p24n4j7tHgNVCjsfHVNUbo=
+github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf h1:7+FW5aGwISbqUtkfmIpZJGRgNFg2ioYPvFaUxdqpDsg=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf/go.mod h1:RpwtwJQFrIEPstU94h88MWPXP2ektJZ8cZ0YntAmXiE=
-github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46 h1:wXG2bA8fO7Vv7lLk2PihFMTqmbT173Tje39oKzQ50Mo=
+github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08 h1:V0an7KRw92wmJysvFvtqtKMAPmvS5O0jtB0nYo6t+gs=
-github.com/marcinbor85/gohex v0.0.0-20180128172054-7a43cd876e46/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
+github.com/knq/sysutil v0.0.0-20191005231841-15668db23d08/go.mod h1:dFWs1zEqDjFtnBXsd1vPOZaLsESovai349994nHx3e0=
+github.com/mailru/easyjson v0.7.0 h1:aizVhC/NAAcKWb+5QsU1iNOZb4Yws5UO2I+aIprQITM=
+github.com/mailru/easyjson v0.7.0/go.mod h1:KAzv3t3aY1NaHWoQz1+4F1ccyAH66Jk7yos7ldAVICs=
+github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892 h1:6J+qramlHVLmiBOgRiBOnQkno8uprqG6YFFQTt6uYIw=
+github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
@@ -17,43 +30,21 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
 golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
-golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 h1:ZBzSG/7F4eNKz2L3GE9o300RX0Az1Bw5HF7PDraD+qU=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20190227180812-8dcc6e70cdef h1:ymc9FeDom3RIEA3coKokSllBB1hRcMT0tZ1W3Jf9Ids=
-golang.org/x/tools v0.0.0-20190227180812-8dcc6e70cdef/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2 h1:0sfSpGSa544Fwnbot3Oxq/U6SXqjty6Jy/3wRhVS7ig=
 golang.org/x/tools v0.0.0-20200216192241-b320d3a0f5a2/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-tinygo.org/x/go-llvm v0.0.0-20190224120431-7707ae5d1261 h1:rJS2Hga39YAnm7DE4qrPm6Dr/67EOojL0XPzvbEeBiw=
+tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d h1:hcX7vpB067GWM/EH4sGGOti0PMgIx+0bbZwUXctOIvE=
-tinygo.org/x/go-llvm v0.0.0-20190224120431-7707ae5d1261/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
+tinygo.org/x/go-llvm v0.0.0-20200503225853-345b2947b59d/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20190818154551-95bc4ffe1add h1:dFjMH1sLhYADg8UQm7DB56B7e+TfvAmWmEZLhyv3r/w=
-tinygo.org/x/go-llvm v0.0.0-20190818154551-95bc4ffe1add/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20191103182207-90b6e4bdc0b9 h1:d6rAX39a3C0pKrY5HcojEGyN8w9ocU0v7X28lC/TRKU=
-tinygo.org/x/go-llvm v0.0.0-20191103182207-90b6e4bdc0b9/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20191103200204-37e93e3f04e2 h1:Q5Hv3e5cLMGkiYwYgZL1Zrv6nb/EY+DJpRWrdO6ws6o=
-tinygo.org/x/go-llvm v0.0.0-20191103200204-37e93e3f04e2/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20191113125529-bad6d01809e8 h1:9Bfvso+tTVQg16UzOA614NaYA4x8vsRBNtd3eBrXwp0=
-tinygo.org/x/go-llvm v0.0.0-20191113125529-bad6d01809e8/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20191124211856-b2db3df3f257 h1:o8VDylrMN7gWemBMu8rEyuogKPhcLTdx5KrUAp9macc=
-tinygo.org/x/go-llvm v0.0.0-20191124211856-b2db3df3f257/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20191215173731-ad71f3d24aae h1:s8J5EyxCkHxXB08UI3gk9W9IS/ekizRvSX+PfZxnAB0=
-tinygo.org/x/go-llvm v0.0.0-20191215173731-ad71f3d24aae/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20200104190746-1ff21df33566 h1:a4y30bTf7U0zDA75v2PTL+XQ2OzJetj19gK8XwQpUNY=
-tinygo.org/x/go-llvm v0.0.0-20200104190746-1ff21df33566/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20200226165415-53522ab6713d h1:mtgZh/e8a3wxneQFuLXoQYO//1mvlki02yZ1JCwMKp4=
-tinygo.org/x/go-llvm v0.0.0-20200226165415-53522ab6713d/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=
-tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a h1:Ugje2Lxuv8CFncHzs5W+hWfJvPsM+W4K0zRvzFbLvoE=
-tinygo.org/x/go-llvm v0.0.0-20200401165421-8d120882fc7a/go.mod h1:fv1F0BSNpxMfCL0zF3M4OPFbgYHnhtB6ST0HvUtu/LE=

goenv/version.go

@@ -0,0 +1,68 @@
+package goenv
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+// Version of TinyGo.
+// Update this value before release of new version of software.
+const Version = "0.15.0"
+
+// GetGorootVersion returns the major and minor version for a given GOROOT path.
+// If the goroot cannot be determined, (0, 0) is returned.
+func GetGorootVersion(goroot string) (major, minor int, err error) {
+	s, err := GorootVersionString(goroot)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	if s == "" || s[:2] != "go" {
+		return 0, 0, errors.New("could not parse Go version: version does not start with 'go' prefix")
+	}
+
+	parts := strings.Split(s[2:], ".")
+	if len(parts) < 2 {
+		return 0, 0, errors.New("could not parse Go version: version has less than two parts")
+	}
+
+	// Ignore the errors, we don't really handle errors here anyway.
+	var trailing string
+	n, err := fmt.Sscanf(s, "go%d.%d%s", &major, &minor, &trailing)
+	if n == 2 && err == io.EOF {
+		// Means there were no trailing characters (i.e., not an alpha/beta)
+		err = nil
+	}
+	if err != nil {
+		return 0, 0, fmt.Errorf("failed to parse version: %s", err)
+	}
+	return
+}
+
+// GorootVersionString returns the version string as reported by the Go
+// toolchain for the given GOROOT path. It is usually of the form `go1.x.y` but
+// can have some variations (for beta releases, for example).
+func GorootVersionString(goroot string) (string, error) {
+	if data, err := ioutil.ReadFile(filepath.Join(
+		goroot, "src", "runtime", "internal", "sys", "zversion.go")); err == nil {
+
+		r := regexp.MustCompile("const TheVersion = `(.*)`")
+		matches := r.FindSubmatch(data)
+		if len(matches) != 2 {
+			return "", errors.New("Invalid go version output:\n" + string(data))
+		}
+
+		return string(matches[1]), nil
+
+	} else if data, err := ioutil.ReadFile(filepath.Join(goroot, "VERSION")); err == nil {
+		return string(data), nil
+
+	} else {
+		return "", err
+	}
+}

hooks/README.md

@@ -0,0 +1,5 @@
+# Hooks for Docker Hub
+
+Files in this directory are custom commands to be run during the different Docker Hub build phases.
+
+See https://docs.docker.com/docker-hub/builds/advanced/#custom-build-phase-hooks

hooks/post_checkout

@@ -0,0 +1,4 @@
+#!/bin/bash
+# Docker hub does a recursive clone, then checks the branch out,
+# so when a PR adds a submodule (or updates it), it fails.
+git submodule update --init

interp/errors.go

@@ -47,10 +47,12 @@ func (e *Error) Error() string {
 // location of the instruction. The location information may not be complete as
 // it depends on debug information in the IR.
 func (e *evalPackage) errorAt(inst llvm.Value, err error) *Error {
+	pos := getPosition(inst)
 	return &Error{
 		ImportPath: e.packagePath,
-		Pos:        getPosition(inst),
+		Pos:        pos,
 		Err:        err,
+		Traceback:  []ErrorLine{{pos, inst}},
 	}
 }
 

interp/frame.go

@@ -95,7 +95,11 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 			if !operand.IsConstant() || inst.IsVolatile() || (!operand.Underlying.IsAConstantExpr().IsNil() && operand.Underlying.Opcode() == llvm.BitCast) {
 				value = fr.builder.CreateLoad(operand.Value(), inst.Name())
 			} else {
-				value = operand.Load()
+				var err error
+				value, err = operand.Load()
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			}
 			if value.Type() != inst.Type() {
 				return nil, nil, fr.errorAt(inst, errors.New("interp: load: type does not match"))
@@ -107,7 +111,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 			if inst.IsVolatile() {
 				fr.builder.CreateStore(value.Value(), ptr.Value())
 			} else {
-				ptr.Store(value.Value())
+				err := ptr.Store(value.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			}
 		case !inst.IsAGetElementPtrInst().IsNil():
 			value := fr.getLocal(inst.Operand(0))
@@ -308,7 +315,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				}
 				// "key" is a Go string value, which in the TinyGo calling convention is split up
 				// into separate pointer and length parameters.
-				m.PutString(keyBuf, keyLen, valPtr)
+				err := m.PutString(keyBuf, keyLen, valPtr)
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			case callee.Name() == "runtime.hashmapBinarySet":
 				// set a binary (int etc.) key in the map
 				keyBuf := fr.getLocal(inst.Operand(1)).(*LocalValue)
@@ -329,15 +339,24 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					fr.builder.CreateCall(callee, llvmParams, "")
 					continue
 				}
-				m.PutBinary(keyBuf, valPtr)
+				err := m.PutBinary(keyBuf, valPtr)
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 			case callee.Name() == "runtime.stringConcat":
 				// adding two strings together
 				buf1Ptr := fr.getLocal(inst.Operand(0))
 				buf1Len := fr.getLocal(inst.Operand(1))
 				buf2Ptr := fr.getLocal(inst.Operand(2))
 				buf2Len := fr.getLocal(inst.Operand(3))
-				buf1 := getStringBytes(buf1Ptr, buf1Len.Value())
+				buf1, err := getStringBytes(buf1Ptr, buf1Len.Value())
-				buf2 := getStringBytes(buf2Ptr, buf2Len.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
+				buf2, err := getStringBytes(buf2Ptr, buf2Len.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 				result := []byte(string(buf1) + string(buf2))
 				vals := make([]llvm.Value, len(result))
 				for i := range vals {
@@ -401,9 +420,15 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 					return nil, nil, fr.errorAt(inst, errors.New("interp: trying to copy a slice with negative length?"))
 				}
 				for i := int64(0); i < length; i++ {
-					var err error
 					// *dst = *src
-					dstArray.Store(srcArray.Load())
+					val, err := srcArray.Load()
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
+					err = dstArray.Store(val)
+					if err != nil {
+						return nil, nil, fr.errorAt(inst, err)
+					}
 					// dst++
 					dstArrayValue, err := dstArray.GetElementPtr([]uint32{1})
 					if err != nil {
@@ -421,7 +446,10 @@ func (fr *frame) evalBasicBlock(bb, incoming llvm.BasicBlock, indent string) (re
 				// convert a string to a []byte
 				bufPtr := fr.getLocal(inst.Operand(0))
 				bufLen := fr.getLocal(inst.Operand(1))
-				result := getStringBytes(bufPtr, bufLen.Value())
+				result, err := getStringBytes(bufPtr, bufLen.Value())
+				if err != nil {
+					return nil, nil, fr.errorAt(inst, err)
+				}
 				vals := make([]llvm.Value, len(result))
 				for i := range vals {
 					vals[i] = llvm.ConstInt(fr.Mod.Context().Int8Type(), uint64(result[i]), false)

interp/scan.go

@@ -62,6 +62,10 @@ func (e *evalPackage) hasSideEffects(fn llvm.Value) (*sideEffectResult, *Error)
 		return &sideEffectResult{severity: sideEffectNone}, nil
 	case name == "llvm.dbg.value":
 		return &sideEffectResult{severity: sideEffectNone}, nil
+	case name == "(*sync/atomic.Value).Load" || name == "(*sync/atomic.Value).Store":
+		// These functions do some unsafe pointer loading/storing but are
+		// otherwise safe.
+		return &sideEffectResult{severity: sideEffectLimited}, nil
 	case strings.HasPrefix(name, "llvm.lifetime."):
 		return &sideEffectResult{severity: sideEffectNone}, nil
 	}
@@ -122,6 +126,8 @@ func (e *evalPackage) hasSideEffects(fn llvm.Value) (*sideEffectResult, *Error)
 					// External function call. Assume only limited side effects
 					// (no affected globals, etc.).
 					switch child.Name() {
+					case "runtime.alloc":
+						continue
 					case "runtime.typeAssert":
 						continue // implemented in interp
 					case "runtime.interfaceImplements":

interp/utils.go

@@ -1,6 +1,8 @@
 package interp
 
 import (
+	"errors"
+
 	"tinygo.org/x/go-llvm"
 )
 
@@ -18,20 +20,23 @@ func getUses(value llvm.Value) []llvm.Value {
 
 // getStringBytes loads the byte slice of a Go string represented as a
 // {ptr, len} pair.
-func getStringBytes(strPtr Value, strLen llvm.Value) []byte {
+func getStringBytes(strPtr Value, strLen llvm.Value) ([]byte, error) {
 	if !strLen.IsConstant() {
-		panic("getStringBytes with a non-constant length")
+		return nil, errors.New("getStringBytes with a non-constant length")
 	}
 	buf := make([]byte, strLen.ZExtValue())
 	for i := range buf {
 		gep, err := strPtr.GetElementPtr([]uint32{uint32(i)})
 		if err != nil {
-			panic(err) // TODO
+			return nil, err
+		}
+		c, err := gep.Load()
+		if err != nil {
+			return nil, err
 		}
-		c := gep.Load()
 		buf[i] = byte(c.ZExtValue())
 	}
-	return buf
+	return buf, nil
 }
 
 // getLLVMIndices converts an []uint32 into an []llvm.Value, for use in

interp/values.go

@@ -15,8 +15,8 @@ type Value interface {
 	Value() llvm.Value                     // returns a LLVM value
 	Type() llvm.Type                       // equal to Value().Type()
 	IsConstant() bool                      // returns true if this value is a constant value
-	Load() llvm.Value                      // dereference a pointer
+	Load() (llvm.Value, error)             // dereference a pointer
-	Store(llvm.Value)                      // store to a pointer
+	Store(llvm.Value) error                // store to a pointer
 	GetElementPtr([]uint32) (Value, error) // returns an interior pointer
 	String() string                        // string representation, for debugging
 }
@@ -44,29 +44,32 @@ func (v *LocalValue) IsConstant() bool {
 }
 
 // Load loads a constant value if this is a constant pointer.
-func (v *LocalValue) Load() llvm.Value {
+func (v *LocalValue) Load() (llvm.Value, error) {
 	if !v.Underlying.IsAGlobalVariable().IsNil() {
-		return v.Underlying.Initializer()
+		return v.Underlying.Initializer(), nil
 	}
 	switch v.Underlying.Opcode() {
 	case llvm.GetElementPtr:
 		indices := v.getConstGEPIndices()
 		if indices[0] != 0 {
-			panic("invalid GEP")
+			return llvm.Value{}, errors.New("invalid GEP")
 		}
 		global := v.Eval.getValue(v.Underlying.Operand(0))
-		agg := global.Load()
+		agg, err := global.Load()
-		return llvm.ConstExtractValue(agg, indices[1:])
+		if err != nil {
+			return llvm.Value{}, err
+		}
+		return llvm.ConstExtractValue(agg, indices[1:]), nil
 	case llvm.BitCast:
-		panic("interp: load from a bitcast")
+		return llvm.Value{}, errors.New("interp: load from a bitcast")
 	default:
-		panic("interp: load from a constant")
+		return llvm.Value{}, errors.New("interp: load from a constant")
 	}
 }
 
 // Store stores to the underlying value if the value type is a pointer type,
-// otherwise it panics.
+// otherwise it returns an error.
-func (v *LocalValue) Store(value llvm.Value) {
+func (v *LocalValue) Store(value llvm.Value) error {
 	if !v.Underlying.IsAGlobalVariable().IsNil() {
 		if !value.IsConstant() {
 			v.MarkDirty()
@@ -74,26 +77,28 @@ func (v *LocalValue) Store(value llvm.Value) {
 		} else {
 			v.Underlying.SetInitializer(value)
 		}
-		return
+		return nil
 	}
 	if !value.IsConstant() {
 		v.MarkDirty()
 		v.Eval.builder.CreateStore(value, v.Underlying)
-		return
+		return nil
 	}
 	switch v.Underlying.Opcode() {
 	case llvm.GetElementPtr:
 		indices := v.getConstGEPIndices()
 		if indices[0] != 0 {
-			panic("invalid GEP")
+			return errors.New("invalid GEP")
 		}
 		global := &LocalValue{v.Eval, v.Underlying.Operand(0)}
-		agg := global.Load()
+		agg, err := global.Load()
+		if err != nil {
+			return err
+		}
 		agg = llvm.ConstInsertValue(agg, value, indices[1:])
-		global.Store(agg)
+		return global.Store(agg)
-		return
 	default:
-		panic("interp: store on a constant")
+		return errors.New("interp: store on a constant")
 	}
 }
 
@@ -225,7 +230,11 @@ func (v *MapValue) Value() llvm.Value {
 			keyPtr := llvm.ConstExtractValue(llvmKey, []uint32{0})
 			keyLen := llvm.ConstExtractValue(llvmKey, []uint32{1})
 			keyPtrVal := v.Eval.getValue(keyPtr)
-			keyBuf = getStringBytes(keyPtrVal, keyLen)
+			var err error
+			keyBuf, err = getStringBytes(keyPtrVal, keyLen)
+			if err != nil {
+				panic(err) // TODO
+			}
 		} else if key.Type().TypeKind() == llvm.IntegerTypeKind {
 			keyBuf = make([]byte, v.Eval.TargetData.TypeAllocSize(key.Type()))
 			n := key.Value().ZExtValue()
@@ -299,13 +308,15 @@ func (v *MapValue) IsConstant() bool {
 }
 
 // Load panics: maps are of reference type so cannot be dereferenced.
-func (v *MapValue) Load() llvm.Value {
+func (v *MapValue) Load() (llvm.Value, error) {
 	panic("interp: load from a map")
 }
 
-// Store panics: maps are of reference type so cannot be stored to.
+// Store returns an error: maps are of reference type so cannot be stored to.
-func (v *MapValue) Store(value llvm.Value) {
+func (v *MapValue) Store(value llvm.Value) error {
-	panic("interp: store on a map")
+	// This must be a bug, but it might be helpful to indicate the location
+	// anyway.
+	return errors.New("interp: store on a map")
 }
 
 // GetElementPtr panics: maps are of reference type so their (interior)
@@ -316,23 +327,26 @@ func (v *MapValue) GetElementPtr(indices []uint32) (Value, error) {
 
 // PutString does a map assign operation, assuming that the map is of type
 // map[string]T.
-func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) {
+func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) error {
 	if !v.Underlying.IsNil() {
-		panic("map already created")
+		return errors.New("map already created")
 	}
 
 	if valPtr.Underlying.Opcode() == llvm.BitCast {
 		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
 	}
-	value := valPtr.Load()
+	value, err := valPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.ValueType.IsNil() {
 		v.ValueType = value.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
-			panic("interp: map store value type has the wrong size")
+			return errors.New("interp: map store value type has the wrong size")
 		}
 	} else {
 		if value.Type() != v.ValueType {
-			panic("interp: map store value type is inconsistent")
+			return errors.New("interp: map store value type is inconsistent")
 		}
 	}
 
@@ -345,26 +359,31 @@ func (v *MapValue) PutString(keyBuf, keyLen, valPtr *LocalValue) {
 	// TODO: avoid duplicate keys
 	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
 	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+
+	return nil
 }
 
 // PutBinary does a map assign operation.
-func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
+func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) error {
 	if !v.Underlying.IsNil() {
-		panic("map already created")
+		return errors.New("map already created")
 	}
 
 	if valPtr.Underlying.Opcode() == llvm.BitCast {
 		valPtr = &LocalValue{v.Eval, valPtr.Underlying.Operand(0)}
 	}
-	value := valPtr.Load()
+	value, err := valPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.ValueType.IsNil() {
 		v.ValueType = value.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.ValueType)) != v.ValueSize {
-			panic("interp: map store value type has the wrong size")
+			return errors.New("interp: map store value type has the wrong size")
 		}
 	} else {
 		if value.Type() != v.ValueType {
-			panic("interp: map store value type is inconsistent")
+			return errors.New("interp: map store value type is inconsistent")
 		}
 	}
 
@@ -375,21 +394,26 @@ func (v *MapValue) PutBinary(keyPtr, valPtr *LocalValue) {
 			keyPtr = &LocalValue{v.Eval, keyPtr.Underlying.Operand(0)}
 		}
 	}
-	key := keyPtr.Load()
+	key, err := keyPtr.Load()
+	if err != nil {
+		return err
+	}
 	if v.KeyType.IsNil() {
 		v.KeyType = key.Type()
 		if int(v.Eval.TargetData.TypeAllocSize(v.KeyType)) != v.KeySize {
-			panic("interp: map store key type has the wrong size")
+			return errors.New("interp: map store key type has the wrong size")
 		}
 	} else {
 		if key.Type() != v.KeyType {
-			panic("interp: map store key type is inconsistent")
+			return errors.New("interp: map store key type is inconsistent")
 		}
 	}
 
 	// TODO: avoid duplicate keys
 	v.Keys = append(v.Keys, &LocalValue{v.Eval, key})
 	v.Values = append(v.Values, &LocalValue{v.Eval, value})
+
+	return nil
 }
 
 // Get FNV-1a hash of this string.

ir/ir.go

@@ -63,73 +63,14 @@ const (
 )
 
 // Create and initialize a new *Program from a *ssa.Program.
-func NewProgram(lprogram *loader.Program, mainPath string) *Program {
+func NewProgram(lprogram *loader.Program) *Program {
 	program := lprogram.LoadSSA()
 	program.Build()
 
-	// Find the main package, which is a bit difficult when running a .go file
+	mainPkg := program.ImportedPackage(lprogram.MainPkg().ImportPath)
-	// directly.
-	mainPkg := program.ImportedPackage(mainPath)
-	if mainPkg == nil {
-		for _, pkgInfo := range program.AllPackages() {
-			if pkgInfo.Pkg.Name() == "main" {
-				if mainPkg != nil {
-					panic("more than one main package found")
-				}
-				mainPkg = pkgInfo
-			}
-		}
-	}
 	if mainPkg == nil {
 		panic("could not find main package")
 	}
-
-	// Make a list of packages in import order.
-	packageList := []*ssa.Package{}
-	packageSet := map[string]struct{}{}
-	worklist := []string{"runtime", mainPath}
-	for len(worklist) != 0 {
-		pkgPath := worklist[0]
-		var pkg *ssa.Package
-		if pkgPath == mainPath {
-			pkg = mainPkg // necessary for compiling individual .go files
-		} else {
-			pkg = program.ImportedPackage(pkgPath)
-		}
-		if pkg == nil {
-			// Non-SSA package (e.g. cgo).
-			packageSet[pkgPath] = struct{}{}
-			worklist = worklist[1:]
-			continue
-		}
-		if _, ok := packageSet[pkgPath]; ok {
-			// Package already in the final package list.
-			worklist = worklist[1:]
-			continue
-		}
-
-		unsatisfiedImports := make([]string, 0)
-		imports := pkg.Pkg.Imports()
-		for _, pkg := range imports {
-			if _, ok := packageSet[pkg.Path()]; ok {
-				continue
-			}
-			unsatisfiedImports = append(unsatisfiedImports, pkg.Path())
-		}
-		if len(unsatisfiedImports) == 0 {
-			// All dependencies of this package are satisfied, so add this
-			// package to the list.
-			packageList = append(packageList, pkg)
-			packageSet[pkgPath] = struct{}{}
-			worklist = worklist[1:]
-		} else {
-			// Prepend all dependencies to the worklist and reconsider this
-			// package (by not removing it from the worklist). At that point, it
-			// must be possible to add it to packageList.
-			worklist = append(unsatisfiedImports, worklist...)
-		}
-	}
-
 	p := &Program{
 		Program:       program,
 		LoaderProgram: lprogram,
@@ -137,8 +78,8 @@ func NewProgram(lprogram *loader.Program, mainPath string) *Program {
 		functionMap:   make(map[*ssa.Function]*Function),
 	}
 
-	for _, pkg := range packageList {
+	for _, pkg := range lprogram.Sorted() {
-		p.AddPackage(pkg)
+		p.AddPackage(program.ImportedPackage(pkg.ImportPath))
 	}
 
 	return p

loader/errors.go

@@ -1,9 +1,6 @@
 package loader
 
-import (
+import "go/scanner"
-	"go/token"
-	"strings"
-)
 
 // Errors contains a list of parser errors or a list of typechecker errors for
 // the given package.
@@ -16,24 +13,13 @@ func (e Errors) Error() string {
 	return "could not compile: " + e.Errs[0].Error()
 }
 
-// ImportCycleErrors is returned when encountering an import cycle. The list of
+// Error is a regular error but with an added import stack. This is especially
-// packages is a list from the root package to the leaf package that imports one
+// useful for debugging import cycle errors.
-// of the packages in the list.
+type Error struct {
-type ImportCycleError struct {
+	ImportStack []string
-	Packages        []string
+	Err         scanner.Error
-	ImportPositions []token.Position
 }
 
-func (e *ImportCycleError) Error() string {
+func (e Error) Error() string {
-	var msg strings.Builder
+	return e.Err.Error()
-	msg.WriteString("import cycle:\n\t")
-	msg.WriteString(strings.Join(e.Packages, "\n\t"))
-	msg.WriteString("\n at ")
-	for i, pos := range e.ImportPositions {
-		if i > 0 {
-			msg.WriteString(", ")
-		}
-		msg.WriteString(pos.String())
-	}
-	return msg.String()
 }

loader/goroot.go

@@ -0,0 +1,281 @@
+package loader
+
+// This file constructs a new temporary GOROOT directory by merging both the
+// standard Go GOROOT and the GOROOT from TinyGo using symlinks.
+
+import (
+	"crypto/sha512"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"runtime"
+	"sync"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/goenv"
+)
+
+var gorootCreateMutex sync.Mutex
+
+// GetCachedGoroot creates a new GOROOT by merging both the standard GOROOT and
+// the GOROOT from TinyGo using lots of symbolic links.
+func GetCachedGoroot(config *compileopts.Config) (string, error) {
+	goroot := goenv.Get("GOROOT")
+	if goroot == "" {
+		return "", errors.New("could not determine GOROOT")
+	}
+	tinygoroot := goenv.Get("TINYGOROOT")
+	if tinygoroot == "" {
+		return "", errors.New("could not determine TINYGOROOT")
+	}
+
+	// Determine the location of the cached GOROOT.
+	version, err := goenv.GorootVersionString(goroot)
+	if err != nil {
+		return "", err
+	}
+	// This hash is really a cache key, that contains (hopefully) enough
+	// information to make collisions unlikely during development.
+	// By including the Go version and TinyGo version, cache collisions should
+	// not happen outside of development.
+	hash := sha512.New512_256()
+	fmt.Fprintln(hash, goroot)
+	fmt.Fprintln(hash, version)
+	fmt.Fprintln(hash, goenv.Version)
+	fmt.Fprintln(hash, tinygoroot)
+	gorootsHash := hash.Sum(nil)
+	gorootsHashHex := hex.EncodeToString(gorootsHash[:])
+	cachedgorootName := "goroot-" + version + "-" + gorootsHashHex
+	cachedgoroot := filepath.Join(goenv.Get("GOCACHE"), cachedgorootName)
+	if needsSyscallPackage(config.BuildTags()) {
+		cachedgoroot += "-syscall"
+	}
+
+	// Do not try to create the cached GOROOT in parallel, that's only a waste
+	// of I/O bandwidth and thus speed. Instead, use a mutex to make sure only
+	// one goroutine does it at a time.
+	// This is not a way to ensure atomicity (a different TinyGo invocation
+	// could be creating the same directory), but instead a way to avoid
+	// creating it many times in parallel when running tests in parallel.
+	gorootCreateMutex.Lock()
+	defer gorootCreateMutex.Unlock()
+
+	if _, err := os.Stat(cachedgoroot); err == nil {
+		return cachedgoroot, nil
+	}
+	err = os.MkdirAll(goenv.Get("GOCACHE"), 0777)
+	if err != nil {
+		return "", err
+	}
+	tmpgoroot, err := ioutil.TempDir(goenv.Get("GOCACHE"), cachedgorootName+".tmp")
+	if err != nil {
+		return "", err
+	}
+
+	// Remove the temporary directory if it wasn't moved to the right place
+	// (for example, when there was an error).
+	defer os.RemoveAll(tmpgoroot)
+
+	for _, name := range []string{"bin", "lib", "pkg"} {
+		err = symlink(filepath.Join(goroot, name), filepath.Join(tmpgoroot, name))
+		if err != nil {
+			return "", err
+		}
+	}
+	err = mergeDirectory(goroot, tinygoroot, tmpgoroot, "", pathsToOverride(needsSyscallPackage(config.BuildTags())))
+	if err != nil {
+		return "", err
+	}
+	err = os.Rename(tmpgoroot, cachedgoroot)
+	if err != nil {
+		if os.IsExist(err) {
+			// Another invocation of TinyGo also seems to have created a GOROOT.
+			// Use that one instead. Our new GOROOT will be automatically
+			// deleted by the defer above.
+			return cachedgoroot, nil
+		}
+		if runtime.GOOS == "windows" && os.IsPermission(err) {
+			// On Windows, a rename with a destination directory that already
+			// exists does not result in an IsExist error, but rather in an
+			// access denied error. To be sure, check for this case by checking
+			// whether the target directory exists.
+			if _, err := os.Stat(cachedgoroot); err == nil {
+				return cachedgoroot, nil
+			}
+		}
+		return "", err
+	}
+	return cachedgoroot, nil
+}
+
+// mergeDirectory merges two roots recursively. The tmpgoroot is the directory
+// that will be created by this call by either symlinking the directory from
+// goroot or tinygoroot, or by creating the directory and merging the contents.
+func mergeDirectory(goroot, tinygoroot, tmpgoroot, importPath string, overrides map[string]bool) error {
+	if mergeSubdirs, ok := overrides[importPath+"/"]; ok {
+		if !mergeSubdirs {
+			// This directory and all subdirectories should come from the TinyGo
+			// root, so simply make a symlink.
+			newname := filepath.Join(tmpgoroot, "src", importPath)
+			oldname := filepath.Join(tinygoroot, "src", importPath)
+			return symlink(oldname, newname)
+		}
+
+		// Merge subdirectories. Start by making the directory to merge.
+		err := os.Mkdir(filepath.Join(tmpgoroot, "src", importPath), 0777)
+		if err != nil {
+			return err
+		}
+
+		// Symlink all files from TinyGo, and symlink directories from TinyGo
+		// that need to be overridden.
+		tinygoEntries, err := ioutil.ReadDir(filepath.Join(tinygoroot, "src", importPath))
+		if err != nil {
+			return err
+		}
+		for _, e := range tinygoEntries {
+			if e.IsDir() {
+				// A directory, so merge this thing.
+				err := mergeDirectory(goroot, tinygoroot, tmpgoroot, path.Join(importPath, e.Name()), overrides)
+				if err != nil {
+					return err
+				}
+			} else {
+				// A file, so symlink this.
+				newname := filepath.Join(tmpgoroot, "src", importPath, e.Name())
+				oldname := filepath.Join(tinygoroot, "src", importPath, e.Name())
+				err := symlink(oldname, newname)
+				if err != nil {
+					return err
+				}
+			}
+		}
+
+		// Symlink all directories from $GOROOT that are not part of the TinyGo
+		// overrides.
+		gorootEntries, err := ioutil.ReadDir(filepath.Join(goroot, "src", importPath))
+		if err != nil {
+			return err
+		}
+		for _, e := range gorootEntries {
+			if !e.IsDir() {
+				// Don't merge in files from Go. Otherwise we'd end up with a
+				// weird syscall package with files from both roots.
+				continue
+			}
+			if _, ok := overrides[path.Join(importPath, e.Name())+"/"]; ok {
+				// Already included above, so don't bother trying to create this
+				// symlink.
+				continue
+			}
+			newname := filepath.Join(tmpgoroot, "src", importPath, e.Name())
+			oldname := filepath.Join(goroot, "src", importPath, e.Name())
+			err := symlink(oldname, newname)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// needsSyscallPackage returns whether the syscall package should be overriden
+// with the TinyGo version. This is the case on some targets.
+func needsSyscallPackage(buildTags []string) bool {
+	for _, tag := range buildTags {
+		if tag == "baremetal" || tag == "darwin" || tag == "nintendoswitch" {
+			return true
+		}
+	}
+	return false
+}
+
+// The boolean indicates whether to merge the subdirs. True means merge, false
+// means use the TinyGo version.
+func pathsToOverride(needsSyscallPackage bool) map[string]bool {
+	paths := map[string]bool{
+		"/":                     true,
+		"device/":               false,
+		"examples/":             false,
+		"internal/":             true,
+		"internal/bytealg/":     false,
+		"internal/reflectlite/": false,
+		"internal/task/":        false,
+		"machine/":              false,
+		"os/":                   true,
+		"reflect/":              false,
+		"runtime/":              false,
+		"sync/":                 true,
+		"testing/":              true,
+	}
+	if needsSyscallPackage {
+		paths["syscall/"] = true // include syscall/js
+	}
+	return paths
+}
+
+// symlink creates a symlink or something similar. On Unix-like systems, it
+// always creates a symlink. On Windows, it tries to create a symlink and if
+// that fails, creates a hardlink or directory junction instead.
+//
+// Note that while Windows 10 does support symlinks and allows them to be
+// created using os.Symlink, it requires developer mode to be enabled.
+// Therefore provide a fallback for when symlinking is not possible.
+// Unfortunately this fallback only works when TinyGo is installed on the same
+// filesystem as the TinyGo cache and the Go installation (which is usually the
+// C drive).
+func symlink(oldname, newname string) error {
+	symlinkErr := os.Symlink(oldname, newname)
+	if runtime.GOOS == "windows" && symlinkErr != nil {
+		// Fallback for when developer mode is disabled.
+		// Note that we return the symlink error even if something else fails
+		// later on. This is because symlinks are the easiest to support
+		// (they're also used on Linux and MacOS) and enabling them is easy:
+		// just enable developer mode.
+		st, err := os.Stat(oldname)
+		if err != nil {
+			return symlinkErr
+		}
+		if st.IsDir() {
+			// Make a directory junction. There may be a way to do this
+			// programmatically, but it involves a lot of magic. Use the mklink
+			// command built into cmd instead (mklink is a builtin, not an
+			// external command).
+			err := exec.Command("cmd", "/k", "mklink", "/J", newname, oldname).Run()
+			if err != nil {
+				return symlinkErr
+			}
+		} else {
+			// Try making a hard link.
+			err := os.Link(oldname, newname)
+			if err != nil {
+				// Making a hardlink failed. Try copying the file as a last
+				// fallback.
+				inf, err := os.Open(oldname)
+				if err != nil {
+					return err
+				}
+				defer inf.Close()
+				outf, err := os.Create(newname)
+				if err != nil {
+					return err
+				}
+				defer outf.Close()
+				_, err = io.Copy(outf, inf)
+				if err != nil {
+					os.Remove(newname)
+					return err
+				}
+				// File was copied.
+			}
+		}
+		return nil // success
+	}
+	return symlinkErr
+}

loader/list.go

@@ -0,0 +1,30 @@
+package loader
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/tinygo-org/tinygo/compileopts"
+)
+
+// List returns a ready-to-run *exec.Cmd for running the `go list` command with
+// the configuration used for TinyGo.
+func List(config *compileopts.Config, extraArgs, pkgs []string) (*exec.Cmd, error) {
+	goroot, err := GetCachedGoroot(config)
+	if err != nil {
+		return nil, err
+	}
+	args := append([]string{"list"}, extraArgs...)
+	if len(config.BuildTags()) != 0 {
+		args = append(args, "-tags", strings.Join(config.BuildTags(), " "))
+	}
+	args = append(args, pkgs...)
+	cgoEnabled := "0"
+	if config.CgoEnabled() {
+		cgoEnabled = "1"
+	}
+	cmd := exec.Command("go", args...)
+	cmd.Env = append(os.Environ(), "GOROOT="+goroot, "GOOS="+config.GOOS(), "GOARCH="+config.GOARCH(), "CGO_ENABLED="+cgoEnabled)
+	return cmd, nil
+}

loader/loader.go

@@ -2,226 +2,239 @@ package loader
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
+	"fmt"
 	"go/ast"
-	"go/build"
 	"go/parser"
 	"go/scanner"
 	"go/token"
 	"go/types"
+	"io"
 	"os"
+	"os/exec"
 	"path/filepath"
-	"sort"
+	"strconv"
 	"strings"
-	"text/template"
+	"syscall"
 
 	"github.com/tinygo-org/tinygo/cgo"
+	"github.com/tinygo-org/tinygo/compileopts"
+	"github.com/tinygo-org/tinygo/goenv"
 )
 
 // Program holds all packages and some metadata about the program as a whole.
 type Program struct {
-	mainPkg      string
+	config       *compileopts.Config
-	Build        *build.Context
+	clangHeaders string
-	OverlayBuild *build.Context
+	typeChecker  types.Config
-	OverlayPath  func(path string) string
+	goroot       string // synthetic GOROOT
-	Packages     map[string]*Package
+	workingDir   string
-	sorted       []*Package
+
-	fset         *token.FileSet
+	Packages map[string]*Package
-	TypeChecker  types.Config
+	sorted   []*Package
-	Dir          string // current working directory (for error reporting)
+	fset     *token.FileSet
-	TINYGOROOT   string // root of the TinyGo installation or root of the source code
+
-	CFlags       []string
+	// Information obtained during parsing.
-	ClangHeaders string
+	LDFlags []string
+}
+
+// PackageJSON is a subset of the JSON struct returned from `go list`.
+type PackageJSON struct {
+	Dir        string
+	ImportPath string
+	ForTest    string
+
+	// Source files
+	GoFiles  []string
+	CgoFiles []string
+	CFiles   []string
+
+	// Dependency information
+	Imports   []string
+	ImportMap map[string]string
+
+	// Error information
+	Error *struct {
+		ImportStack []string
+		Pos         string
+		Err         string
+	}
 }
 
 // Package holds a loaded package, its imports, and its parsed files.
 type Package struct {
-	*Program
+	PackageJSON
-	*build.Package
+
-	Imports   map[string]*Package
+	program *Program
-	Importing bool
+	Files   []*ast.File
-	Files     []*ast.File
+	Pkg     *types.Package
-	Pkg       *types.Package
+	info    types.Info
-	types.Info
 }
 
-// Import loads the given package relative to srcDir (for the vendor directory).
+// Load loads the given package with all dependencies (including the runtime
-// It only loads the current package without recursion.
+// package). Call .Parse() afterwards to parse all Go files (including CGo
-func (p *Program) Import(path, srcDir string, pos token.Position) (*Package, error) {
+// processing, if necessary).
-	if p.Packages == nil {
+func Load(config *compileopts.Config, inputPkgs []string, clangHeaders string, typeChecker types.Config) (*Program, error) {
-		p.Packages = make(map[string]*Package)
+	goroot, err := GetCachedGoroot(config)
-	}
-
-	// Load this package.
-	ctx := p.Build
-	if newPath := p.OverlayPath(path); newPath != "" {
-		ctx = p.OverlayBuild
-		path = newPath
-	}
-	buildPkg, err := ctx.Import(path, srcDir, build.ImportComment)
-	if err != nil {
-		return nil, scanner.Error{
-			Pos: pos,
-			Msg: err.Error(), // TODO: define a new error type that will wrap the inner error
-		}
-	}
-	if existingPkg, ok := p.Packages[buildPkg.ImportPath]; ok {
-		// Already imported, or at least started the import.
-		return existingPkg, nil
-	}
-	p.sorted = nil // invalidate the sorted order of packages
-	pkg := p.newPackage(buildPkg)
-	p.Packages[buildPkg.ImportPath] = pkg
-
-	if p.mainPkg == "" {
-		p.mainPkg = buildPkg.ImportPath
-	}
-
-	return pkg, nil
-}
-
-// ImportFile loads and parses the import statements in the given path and
-// creates a pseudo-package out of it.
-func (p *Program) ImportFile(path string) (*Package, error) {
-	if p.Packages == nil {
-		p.Packages = make(map[string]*Package)
-	}
-	if _, ok := p.Packages[path]; ok {
-		// unlikely
-		return nil, errors.New("loader: cannot import file that is already imported as package: " + path)
-	}
-
-	file, err := p.parseFile(path, parser.ImportsOnly)
 	if err != nil {
 		return nil, err
 	}
-	buildPkg := &build.Package{
+	wd, err := os.Getwd()
-		Dir:        filepath.Dir(path),
+	if err != nil {
-		ImportPath: path,
+		return nil, err
-		GoFiles:    []string{filepath.Base(path)},
 	}
-	for _, importSpec := range file.Imports {
+	p := &Program{
-		buildPkg.Imports = append(buildPkg.Imports, importSpec.Path.Value[1:len(importSpec.Path.Value)-1])
+		config:       config,
-	}
+		clangHeaders: clangHeaders,
-	p.sorted = nil // invalidate the sorted order of packages
+		typeChecker:  typeChecker,
-	pkg := p.newPackage(buildPkg)
+		goroot:       goroot,
-	p.Packages[buildPkg.ImportPath] = pkg
+		workingDir:   wd,
-
+		Packages:     make(map[string]*Package),
-	if p.mainPkg == "" {
+		fset:         token.NewFileSet(),
-		p.mainPkg = buildPkg.ImportPath
 	}
 
-	return pkg, nil
+	// List the dependencies of this package, in raw JSON format.
+	extraArgs := []string{"-json", "-deps"}
+	if config.TestConfig.CompileTestBinary {
+		extraArgs = append(extraArgs, "-test")
+	}
+	cmd, err := List(config, extraArgs, inputPkgs)
+	if err != nil {
+		return nil, err
+	}
+	buf := &bytes.Buffer{}
+	cmd.Stdout = buf
+	cmd.Stderr = os.Stderr
+	err = cmd.Run()
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+				os.Exit(status.ExitStatus())
+			}
+			os.Exit(1)
+		}
+		return nil, fmt.Errorf("failed to run `go list`: %s", err)
+	}
+
+	// Parse the returned json from `go list`.
+	decoder := json.NewDecoder(buf)
+	for {
+		pkg := &Package{
+			program: p,
+			info: types.Info{
+				Types:      make(map[ast.Expr]types.TypeAndValue),
+				Defs:       make(map[*ast.Ident]types.Object),
+				Uses:       make(map[*ast.Ident]types.Object),
+				Implicits:  make(map[ast.Node]types.Object),
+				Scopes:     make(map[ast.Node]*types.Scope),
+				Selections: make(map[*ast.SelectorExpr]*types.Selection),
+			},
+		}
+		err := decoder.Decode(&pkg.PackageJSON)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
+		if pkg.Error != nil {
+			// There was an error while importing (for example, a circular
+			// dependency).
+			pos := token.Position{}
+			fields := strings.Split(pkg.Error.Pos, ":")
+			if len(fields) >= 2 {
+				// There is some file/line/column information.
+				if n, err := strconv.Atoi(fields[len(fields)-2]); err == nil {
+					// Format: filename.go:line:colum
+					pos.Filename = strings.Join(fields[:len(fields)-2], ":")
+					pos.Line = n
+					pos.Column, _ = strconv.Atoi(fields[len(fields)-1])
+				} else {
+					// Format: filename.go:line
+					pos.Filename = strings.Join(fields[:len(fields)-1], ":")
+					pos.Line, _ = strconv.Atoi(fields[len(fields)-1])
+				}
+				pos.Filename = p.getOriginalPath(pos.Filename)
+			}
+			err := scanner.Error{
+				Pos: pos,
+				Msg: pkg.Error.Err,
+			}
+			if len(pkg.Error.ImportStack) != 0 {
+				return nil, Error{
+					ImportStack: pkg.Error.ImportStack,
+					Err:         err,
+				}
+			}
+			return nil, err
+		}
+		p.sorted = append(p.sorted, pkg)
+		p.Packages[pkg.ImportPath] = pkg
+	}
+
+	return p, nil
 }
 
-// newPackage instantiates a new *Package object with initialized members.
+// getOriginalPath looks whether this path is in the generated GOROOT and if so,
-func (p *Program) newPackage(pkg *build.Package) *Package {
+// replaces the path with the original path (in GOROOT or TINYGOROOT). Otherwise
-	return &Package{
+// the input path is returned.
-		Program: p,
+func (p *Program) getOriginalPath(path string) string {
-		Package: pkg,
+	originalPath := path
-		Imports: make(map[string]*Package, len(pkg.Imports)),
+	if strings.HasPrefix(path, p.goroot+string(filepath.Separator)) {
-		Info: types.Info{
+		// If this file is part of the synthetic GOROOT, try to infer the
-			Types:      make(map[ast.Expr]types.TypeAndValue),
+		// original path.
-			Defs:       make(map[*ast.Ident]types.Object),
+		relpath := path[len(filepath.Join(p.goroot, "src"))+1:]
-			Uses:       make(map[*ast.Ident]types.Object),
+		realgorootPath := filepath.Join(goenv.Get("GOROOT"), "src", relpath)
-			Implicits:  make(map[ast.Node]types.Object),
+		if _, err := os.Stat(realgorootPath); err == nil {
-			Scopes:     make(map[ast.Node]*types.Scope),
+			originalPath = realgorootPath
-			Selections: make(map[*ast.SelectorExpr]*types.Selection),
+		}
-		},
+		maybeInTinyGoRoot := false
+		for prefix := range pathsToOverride(needsSyscallPackage(p.config.BuildTags())) {
+			if !strings.HasPrefix(relpath, prefix) {
+				continue
+			}
+			maybeInTinyGoRoot = true
+		}
+		if maybeInTinyGoRoot {
+			tinygoPath := filepath.Join(goenv.Get("TINYGOROOT"), "src", relpath)
+			if _, err := os.Stat(tinygoPath); err == nil {
+				originalPath = tinygoPath
+			}
+		}
 	}
+	return originalPath
 }
 
 // Sorted returns a list of all packages, sorted in a way that no packages come
 // before the packages they depend upon.
 func (p *Program) Sorted() []*Package {
-	if p.sorted == nil {
-		p.sort()
-	}
 	return p.sorted
 }
 
-func (p *Program) sort() {
+// MainPkg returns the last package in the Sorted() slice. This is the main
-	p.sorted = nil
+// package of the program.
-	packageList := make([]*Package, 0, len(p.Packages))
+func (p *Program) MainPkg() *Package {
-	packageSet := make(map[string]struct{}, len(p.Packages))
+	return p.sorted[len(p.sorted)-1]
-	worklist := make([]string, 0, len(p.Packages))
-	for path := range p.Packages {
-		worklist = append(worklist, path)
-	}
-	sort.Strings(worklist)
-	for len(worklist) != 0 {
-		pkgPath := worklist[0]
-		pkg := p.Packages[pkgPath]
-
-		if _, ok := packageSet[pkgPath]; ok {
-			// Package already in the final package list.
-			worklist = worklist[1:]
-			continue
-		}
-
-		unsatisfiedImports := make([]string, 0)
-		for _, pkg := range pkg.Imports {
-			if _, ok := packageSet[pkg.ImportPath]; ok {
-				continue
-			}
-			unsatisfiedImports = append(unsatisfiedImports, pkg.ImportPath)
-		}
-		sort.Strings(unsatisfiedImports)
-		if len(unsatisfiedImports) == 0 {
-			// All dependencies of this package are satisfied, so add this
-			// package to the list.
-			packageList = append(packageList, pkg)
-			packageSet[pkgPath] = struct{}{}
-			worklist = worklist[1:]
-		} else {
-			// Prepend all dependencies to the worklist and reconsider this
-			// package (by not removing it from the worklist). At that point, it
-			// must be possible to add it to packageList.
-			worklist = append(unsatisfiedImports, worklist...)
-		}
-	}
-
-	p.sorted = packageList
 }
 
-// Parse recursively imports all packages, parses them, and typechecks them.
+// Parse parses all packages and typechecks them.
 //
 // The returned error may be an Errors error, which contains a list of errors.
 //
 // Idempotent.
-func (p *Program) Parse(compileTestBinary bool) error {
+func (p *Program) Parse() error {
-	includeTests := compileTestBinary
-
-	// Load all imports
-	for _, pkg := range p.Sorted() {
-		err := pkg.importRecursively(includeTests)
-		if err != nil {
-			if err, ok := err.(*ImportCycleError); ok {
-				if pkg.ImportPath != err.Packages[0] {
-					err.Packages = append([]string{pkg.ImportPath}, err.Packages...)
-				}
-			}
-			return err
-		}
-	}
-
 	// Parse all packages.
-	for _, pkg := range p.Sorted() {
+	// TODO: do this in parallel.
-		err := pkg.Parse(includeTests)
+	for _, pkg := range p.sorted {
-		if err != nil {
+		err := pkg.Parse()
-			return err
-		}
-	}
-
-	if compileTestBinary {
-		err := p.SwapTestMain()
 		if err != nil {
 			return err
 		}
 	}
 
 	// Typecheck all packages.
-	for _, pkg := range p.Sorted() {
+	for _, pkg := range p.sorted {
 		err := pkg.Check()
 		if err != nil {
 			return err
@@ -231,83 +244,6 @@ func (p *Program) Parse(compileTestBinary bool) error {
 	return nil
 }
 
-func (p *Program) SwapTestMain() error {
-	var tests []string
-
-	isTestFunc := func(f *ast.FuncDecl) bool {
-		// TODO: improve signature check
-		if strings.HasPrefix(f.Name.Name, "Test") && f.Name.Name != "TestMain" {
-			return true
-		}
-		return false
-	}
-	mainPkg := p.Packages[p.mainPkg]
-	for _, f := range mainPkg.Files {
-		for i, d := range f.Decls {
-			switch v := d.(type) {
-			case *ast.FuncDecl:
-				if isTestFunc(v) {
-					tests = append(tests, v.Name.Name)
-				}
-				if v.Name.Name == "main" {
-					// Remove main
-					if len(f.Decls) == 1 {
-						f.Decls = make([]ast.Decl, 0)
-					} else {
-						f.Decls[i] = f.Decls[len(f.Decls)-1]
-						f.Decls = f.Decls[:len(f.Decls)-1]
-					}
-				}
-			}
-		}
-	}
-
-	// TODO: Check if they defined a TestMain and call it instead of testing.TestMain
-	const mainBody = `package main
-
-import (
-	"testing"
-)
-
-func main () {
-	m := &testing.M{
-		Tests: []testing.TestToCall{
-{{range .TestFunctions}}
-			{Name: "{{.}}", Func: {{.}}},
-{{end}}
-		},
-	}
-
-	testing.TestMain(m)
-}
-`
-	tmpl := template.Must(template.New("testmain").Parse(mainBody))
-	b := bytes.Buffer{}
-	tmplData := struct {
-		TestFunctions []string
-	}{
-		TestFunctions: tests,
-	}
-
-	err := tmpl.Execute(&b, tmplData)
-	if err != nil {
-		return err
-	}
-	path := filepath.Join(p.mainPkg, "$testmain.go")
-
-	if p.fset == nil {
-		p.fset = token.NewFileSet()
-	}
-
-	newMain, err := parser.ParseFile(p.fset, path, b.Bytes(), parser.AllErrors)
-	if err != nil {
-		return err
-	}
-	mainPkg.Files = append(mainPkg.Files, newMain)
-
-	return nil
-}
-
 // parseFile is a wrapper around parser.ParseFile.
 func (p *Program) parseFile(path string, mode parser.Mode) (*ast.File, error) {
 	if p.fset == nil {
@@ -319,34 +255,26 @@ func (p *Program) parseFile(path string, mode parser.Mode) (*ast.File, error) {
 		return nil, err
 	}
 	defer rd.Close()
-	relpath := path
+	return parser.ParseFile(p.fset, p.getOriginalPath(path), rd, mode)
-	if filepath.IsAbs(path) {
-		rp, err := filepath.Rel(p.Dir, path)
-		if err == nil {
-			relpath = rp
-		}
-	}
-	return parser.ParseFile(p.fset, relpath, rd, mode)
 }
 
 // Parse parses and typechecks this package.
 //
 // Idempotent.
-func (p *Package) Parse(includeTests bool) error {
+func (p *Package) Parse() error {
 	if len(p.Files) != 0 {
-		return nil
+		return nil // nothing to do (?)
 	}
 
 	// Load the AST.
-	// TODO: do this in parallel.
 	if p.ImportPath == "unsafe" {
-		// Special case for the unsafe package. Don't even bother loading
+		// Special case for the unsafe package, which is defined internally by
-		// the files.
+		// the types package.
 		p.Pkg = types.Unsafe
 		return nil
 	}
 
-	files, err := p.parseFiles(includeTests)
+	files, err := p.parseFiles()
 	if err != nil {
 		return err
 	}
@@ -361,11 +289,11 @@ func (p *Package) Parse(includeTests bool) error {
 // Idempotent.
 func (p *Package) Check() error {
 	if p.Pkg != nil {
-		return nil
+		return nil // already typechecked
 	}
 
 	var typeErrors []error
-	checker := p.TypeChecker
+	checker := p.program.typeChecker // make a copy, because it will be modified
 	checker.Error = func(err error) {
 		typeErrors = append(typeErrors, err)
 	}
@@ -373,7 +301,7 @@ func (p *Package) Check() error {
 	// Do typechecking of the package.
 	checker.Importer = p
 
-	typesPkg, err := checker.Check(p.ImportPath, p.fset, p.Files, &p.Info)
+	typesPkg, err := checker.Check(p.ImportPath, p.program.fset, p.Files, &p.info)
 	if err != nil {
 		if err, ok := err.(Errors); ok {
 			return err
@@ -385,52 +313,47 @@ func (p *Package) Check() error {
 }
 
 // parseFiles parses the loaded list of files and returns this list.
-func (p *Package) parseFiles(includeTests bool) ([]*ast.File, error) {
+func (p *Package) parseFiles() ([]*ast.File, error) {
-	// TODO: do this concurrently.
 	var files []*ast.File
 	var fileErrs []error
 
-	var gofiles []string
+	// Parse all files (incuding CgoFiles).
-	if includeTests {
+	parseFile := func(file string) {
-		gofiles = make([]string, 0, len(p.GoFiles)+len(p.TestGoFiles))
+		if !filepath.IsAbs(file) {
-		gofiles = append(gofiles, p.GoFiles...)
+			file = filepath.Join(p.Dir, file)
-		gofiles = append(gofiles, p.TestGoFiles...)
-	} else {
-		gofiles = p.GoFiles
-	}
-
-	for _, file := range gofiles {
-		f, err := p.parseFile(filepath.Join(p.Package.Dir, file), parser.ParseComments)
-		if err != nil {
-			fileErrs = append(fileErrs, err)
-			continue
 		}
+		f, err := p.program.parseFile(file, parser.ParseComments)
 		if err != nil {
 			fileErrs = append(fileErrs, err)
-			continue
+			return
 		}
 		files = append(files, f)
 	}
+	for _, file := range p.GoFiles {
+		parseFile(file)
+	}
 	for _, file := range p.CgoFiles {
-		path := filepath.Join(p.Package.Dir, file)
+		parseFile(file)
-		f, err := p.parseFile(path, parser.ParseComments)
-		if err != nil {
-			fileErrs = append(fileErrs, err)
-			continue
-		}
-		files = append(files, f)
 	}
+
+	// Do CGo processing.
 	if len(p.CgoFiles) != 0 {
-		cflags := append(p.CFlags, "-I"+p.Package.Dir)
+		var cflags []string
-		if p.ClangHeaders != "" {
+		cflags = append(cflags, p.program.config.CFlags()...)
-			cflags = append(cflags, "-Xclang", "-internal-isystem", "-Xclang", p.ClangHeaders)
+		cflags = append(cflags, "-I"+p.Dir)
+		if p.program.clangHeaders != "" {
+			cflags = append(cflags, "-Xclang", "-internal-isystem", "-Xclang", p.program.clangHeaders)
 		}
-		generated, errs := cgo.Process(files, p.Program.Dir, p.fset, cflags)
+		generated, ldflags, errs := cgo.Process(files, p.program.workingDir, p.program.fset, cflags)
 		if errs != nil {
 			fileErrs = append(fileErrs, errs...)
 		}
 		files = append(files, generated)
+		p.program.LDFlags = append(p.program.LDFlags, ldflags...)
 	}
+
+	// Only return an error after CGo processing, so that errors in parsing and
+	// CGo can be reported together.
 	if len(fileErrs) != 0 {
 		return nil, Errors{p, fileErrs}
 	}
@@ -444,59 +367,14 @@ func (p *Package) Import(to string) (*types.Package, error) {
 	if to == "unsafe" {
 		return types.Unsafe, nil
 	}
-	if _, ok := p.Imports[to]; ok {
+	if replace, ok := p.ImportMap[to]; ok {
-		return p.Imports[to].Pkg, nil
+		// This import path should be replaced by another import path, according
+		// to `go list`.
+		to = replace
+	}
+	if imported, ok := p.program.Packages[to]; ok {
+		return imported.Pkg, nil
 	} else {
 		return nil, errors.New("package not imported: " + to)
 	}
 }
-
-// importRecursively calls Program.Import() on all imported packages, and calls
-// importRecursively() on the imported packages as well.
-//
-// Idempotent.
-func (p *Package) importRecursively(includeTests bool) error {
-	p.Importing = true
-
-	imports := p.Package.Imports
-	if includeTests {
-		imports = append(imports, p.Package.TestImports...)
-	}
-
-	for _, to := range imports {
-		if to == "C" {
-			// Do CGo processing in a later stage.
-			continue
-		}
-		if _, ok := p.Imports[to]; ok {
-			continue
-		}
-		// Find error location.
-		var pos token.Position
-		if len(p.Package.ImportPos[to]) > 0 {
-			pos = p.Package.ImportPos[to][0]
-		} else {
-			pos = token.Position{Filename: p.Package.ImportPath}
-		}
-		importedPkg, err := p.Program.Import(to, p.Package.Dir, pos)
-		if err != nil {
-			if err, ok := err.(*ImportCycleError); ok {
-				err.Packages = append([]string{p.ImportPath}, err.Packages...)
-			}
-			return err
-		}
-		if importedPkg.Importing {
-			return &ImportCycleError{[]string{p.ImportPath, importedPkg.ImportPath}, p.ImportPos[to]}
-		}
-		err = importedPkg.importRecursively(false)
-		if err != nil {
-			if err, ok := err.(*ImportCycleError); ok {
-				err.Packages = append([]string{p.ImportPath}, err.Packages...)
-			}
-			return err
-		}
-		p.Imports[to] = importedPkg
-	}
-	p.Importing = false
-	return nil
-}

loader/ssa.go

@@ -10,8 +10,8 @@ import (
 func (p *Program) LoadSSA() *ssa.Program {
 	prog := ssa.NewProgram(p.fset, ssa.SanityCheckFunctions|ssa.BareInits|ssa.GlobalDebug)
 
-	for _, pkg := range p.Sorted() {
+	for _, pkg := range p.sorted {
-		prog.CreatePackage(pkg.Pkg, pkg.Files, &pkg.Info, true)
+		prog.CreatePackage(pkg.Pkg, pkg.Files, &pkg.info, true)
 	}
 
 	return prog

main.go

@@ -8,6 +8,7 @@ import (
 	"go/scanner"
 	"go/types"
 	"io"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -28,6 +29,12 @@ import (
 	"go.bug.st/serial"
 )
 
+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 {
@@ -58,33 +65,23 @@ func moveFile(src, dst string) error {
 	return os.Remove(src)
 }
 
-// copyFile copies the given file from src to dst. It copies first to a .tmp
+// copyFile copies the given file from src to dst. It can copy over
-// file which is then moved over a possibly already existing file at the
+// a possibly already existing file at the destination.
-// destination.
 func copyFile(src, dst string) error {
-	inf, err := os.Open(src)
+	source, err := os.Open(src)
-	if err != nil {
-		return err
-	}
-	defer inf.Close()
-	outpath := dst + ".tmp"
-	outf, err := os.Create(outpath)
 	if err != nil {
 		return err
 	}
+	defer source.Close()
 
-	_, err = io.Copy(outf, inf)
+	destination, err := os.Create(dst)
-	if err != nil {
-		os.Remove(outpath)
-		return err
-	}
-
-	err = outf.Close()
 	if err != nil {
 		return err
 	}
+	defer destination.Close()
 
-	return os.Rename(dst+".tmp", dst)
+	_, err = io.Copy(destination, source)
+	return err
 }
 
 // Build compiles and links the given package and writes it to outpath.
@@ -94,10 +91,10 @@ func Build(pkgName, outpath string, options *compileopts.Options) error {
 		return err
 	}
 
-	return builder.Build(pkgName, outpath, config, func(tmppath string) error {
+	return builder.Build(pkgName, outpath, config, func(result builder.BuildResult) error {
-		if err := os.Rename(tmppath, outpath); err != nil {
+		if err := os.Rename(result.Binary, outpath); err != nil {
 			// Moving failed. Do a file copy.
-			inf, err := os.Open(tmppath)
+			inf, err := os.Open(result.Binary)
 			if err != nil {
 				return err
 			}
@@ -124,22 +121,17 @@ func Build(pkgName, outpath string, options *compileopts.Options) error {
 
 // Test runs the tests in the given package.
 func Test(pkgName string, options *compileopts.Options) error {
+	options.TestConfig.CompileTestBinary = true
 	config, err := builder.NewConfig(options)
 	if err != nil {
 		return err
 	}
 
-	// Add test build tag. This is incorrect: `go test` only looks at the
+	return builder.Build(pkgName, ".elf", config, func(result builder.BuildResult) error {
-	// _test.go file suffix but does not add the test build tag in the process.
+		cmd := exec.Command(result.Binary)
-	// However, it's a simple fix right now.
-	// For details: https://github.com/golang/go/issues/21360
-	config.Target.BuildTags = append(config.Target.BuildTags, "test")
-
-	options.TestConfig.CompileTestBinary = true
-	return builder.Build(pkgName, ".elf", config, func(tmppath string) error {
-		cmd := exec.Command(tmppath)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
+		cmd.Dir = result.MainDir
 		err := cmd.Run()
 		if err != nil {
 			// Propagate the exit code
@@ -149,7 +141,7 @@ func Test(pkgName string, options *compileopts.Options) error {
 				}
 				os.Exit(1)
 			}
-			return &commandError{"failed to run compiled binary", tmppath, err}
+			return &commandError{"failed to run compiled binary", result.Binary, err}
 		}
 		return nil
 	})
@@ -193,9 +185,9 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 		return errors.New("unknown flash method: " + flashMethod)
 	}
 
-	return builder.Build(pkgName, fileExt, config, func(tmppath string) error {
+	return builder.Build(pkgName, fileExt, config, func(result builder.BuildResult) error {
 		// do we need port reset to put MCU into bootloader mode?
-		if config.Target.PortReset == "true" {
+		if config.Target.PortReset == "true" && flashMethod != "openocd" {
 			if port == "" {
 				var err error
 				port, err = getDefaultPort()
@@ -206,7 +198,7 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 
 			err := touchSerialPortAt1200bps(port)
 			if err != nil {
-				return &commandError{"failed to reset port", tmppath, err}
+				return &commandError{"failed to reset port", result.Binary, err}
 			}
 			// give the target MCU a chance to restart into bootloader
 			time.Sleep(3 * time.Second)
@@ -218,7 +210,7 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			// Create the command.
 			flashCmd := config.Target.FlashCommand
 			fileToken := "{" + fileExt[1:] + "}"
-			flashCmd = strings.Replace(flashCmd, fileToken, tmppath, -1)
+			flashCmd = strings.Replace(flashCmd, fileToken, result.Binary, -1)
 
 			if port == "" && strings.Contains(flashCmd, "{port}") {
 				var err error
@@ -248,21 +240,21 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			cmd.Dir = goenv.Get("TINYGOROOT")
 			err := cmd.Run()
 			if err != nil {
-				return &commandError{"failed to flash", tmppath, err}
+				return &commandError{"failed to flash", result.Binary, err}
 			}
 			return nil
 		case "msd":
 			switch fileExt {
 			case ".uf2":
-				err := flashUF2UsingMSD(config.Target.FlashVolume, tmppath)
+				err := flashUF2UsingMSD(config.Target.FlashVolume, result.Binary)
 				if err != nil {
-					return &commandError{"failed to flash", tmppath, err}
+					return &commandError{"failed to flash", result.Binary, err}
 				}
 				return nil
 			case ".hex":
-				err := flashHexUsingMSD(config.Target.FlashVolume, tmppath)
+				err := flashHexUsingMSD(config.Target.FlashVolume, result.Binary)
 				if err != nil {
-					return &commandError{"failed to flash", tmppath, err}
+					return &commandError{"failed to flash", result.Binary, err}
 				}
 				return nil
 			default:
@@ -273,13 +265,13 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 			if err != nil {
 				return err
 			}
-			args = append(args, "-c", "program "+tmppath+" reset exit")
+			args = append(args, "-c", "program "+filepath.ToSlash(result.Binary)+" reset exit")
 			cmd := exec.Command("openocd", args...)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
 			err = cmd.Run()
 			if err != nil {
-				return &commandError{"failed to flash", tmppath, err}
+				return &commandError{"failed to flash", result.Binary, err}
 			}
 			return nil
 		default:
@@ -304,7 +296,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		return errors.New("gdb not configured in the target specification")
 	}
 
-	return builder.Build(pkgName, "", config, func(tmppath string) error {
+	return builder.Build(pkgName, "", config, func(result builder.BuildResult) error {
 		// Find a good way to run GDB.
 		gdbInterface, openocdInterface := config.Programmer()
 		switch gdbInterface {
@@ -367,7 +359,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			gdbCommands = append(gdbCommands, "target remote :1234")
 
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath, "-s", "-S")
+			args := append(config.Target.Emulator[1:], result.Binary, "-s", "-S")
 			daemon = exec.Command(config.Target.Emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
@@ -375,7 +367,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 			gdbCommands = append(gdbCommands, "target remote :2345")
 
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath, "-g")
+			args := append(config.Target.Emulator[1:], result.Binary, "-g")
 			daemon = exec.Command(config.Target.Emulator[0], args...)
 			daemon.Stdout = os.Stdout
 			daemon.Stderr = os.Stderr
@@ -413,7 +405,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		// Construct and execute a gdb command.
 		// By default: gdb -ex run <binary>
 		// Exit GDB with Ctrl-D.
-		params := []string{tmppath}
+		params := []string{result.Binary}
 		for _, cmd := range gdbCommands {
 			params = append(params, "-ex", cmd)
 		}
@@ -423,7 +415,7 @@ func FlashGDB(pkgName string, ocdOutput bool, options *compileopts.Options) erro
 		cmd.Stderr = os.Stderr
 		err := cmd.Run()
 		if err != nil {
-			return &commandError{"failed to run gdb with", tmppath, err}
+			return &commandError{"failed to run gdb with", result.Binary, err}
 		}
 		return nil
 	})
@@ -439,10 +431,10 @@ func Run(pkgName string, options *compileopts.Options) error {
 		return err
 	}
 
-	return builder.Build(pkgName, ".elf", config, func(tmppath string) error {
+	return builder.Build(pkgName, ".elf", config, func(result builder.BuildResult) error {
 		if len(config.Target.Emulator) == 0 {
 			// Run directly.
-			cmd := exec.Command(tmppath)
+			cmd := exec.Command(result.Binary)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
 			err := cmd.Run()
@@ -451,12 +443,12 @@ func Run(pkgName string, options *compileopts.Options) error {
 					// Workaround for QEMU which always exits with an error.
 					return nil
 				}
-				return &commandError{"failed to run compiled binary", tmppath, err}
+				return &commandError{"failed to run compiled binary", result.Binary, err}
 			}
 			return nil
 		} else {
 			// Run in an emulator.
-			args := append(config.Target.Emulator[1:], tmppath)
+			args := append(config.Target.Emulator[1:], result.Binary)
 			cmd := exec.Command(config.Target.Emulator[0], args...)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
@@ -466,7 +458,7 @@ func Run(pkgName string, options *compileopts.Options) error {
 					// Workaround for QEMU which always exits with an error.
 					return nil
 				}
-				return &commandError{"failed to run emulator with", tmppath, err}
+				return &commandError{"failed to run emulator with", result.Binary, err}
 			}
 			return nil
 		}
@@ -479,6 +471,13 @@ func touchSerialPortAt1200bps(port string) (err error) {
 		// Open port
 		p, e := serial.Open(port, &serial.Mode{BaudRate: 1200})
 		if e != nil {
+			if runtime.GOOS == `windows` {
+				se, ok := e.(*serial.PortError)
+				if ok && se.Code() == serial.InvalidSerialPort {
+					// InvalidSerialPort error occurs when transitioning to boot
+					return nil
+				}
+			}
 			time.Sleep(1 * time.Second)
 			err = e
 			continue
@@ -491,6 +490,8 @@ func touchSerialPortAt1200bps(port string) (err error) {
 	return fmt.Errorf("opening port: %s", err)
 }
 
+const maxMSDRetries = 10
+
 func flashUF2UsingMSD(volume, tmppath string) error {
 	// find standard UF2 info path
 	var infoPath string
@@ -507,15 +508,12 @@ func flashUF2UsingMSD(volume, tmppath string) error {
 		infoPath = path + "/INFO_UF2.TXT"
 	}
 
-	d, err := filepath.Glob(infoPath)
+	d, err := locateDevice(volume, infoPath)
 	if err != nil {
 		return err
 	}
-	if d == nil {
-		return errors.New("unable to locate UF2 device: " + volume)
-	}
 
-	return moveFile(tmppath, filepath.Dir(d[0])+"/flash.uf2")
+	return moveFile(tmppath, filepath.Dir(d)+"/flash.uf2")
 }
 
 func flashHexUsingMSD(volume, tmppath string) error {
@@ -534,15 +532,31 @@ func flashHexUsingMSD(volume, tmppath string) error {
 		destPath = path + "/"
 	}
 
-	d, err := filepath.Glob(destPath)
+	d, err := locateDevice(volume, destPath)
 	if err != nil {
 		return err
 	}
-	if d == nil {
-		return errors.New("unable to locate device: " + volume)
-	}
 
-	return moveFile(tmppath, d[0]+"/flash.hex")
+	return moveFile(tmppath, d+"/flash.hex")
+}
+
+func locateDevice(volume, path string) (string, error) {
+	var d []string
+	var err error
+	for i := 0; i < maxMSDRetries; i++ {
+		d, err = filepath.Glob(path)
+		if err != nil {
+			return "", err
+		}
+		if d != nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if d == nil {
+		return "", errors.New("unable to locate device: " + volume)
+	}
+	return d[0], nil
 }
 
 func windowsFindUSBDrive(volume string) (string, error) {
@@ -603,29 +617,18 @@ func getDefaultPort() (port string, err error) {
 	case "freebsd":
 		portPath = "/dev/cuaU*"
 	case "windows":
-		cmd := exec.Command("wmic",
+		ports, err := serial.GetPortsList()
-			"PATH", "Win32_SerialPort", "WHERE", "Caption LIKE 'USB Serial%'", "GET", "DeviceID")
-
-		var out bytes.Buffer
-		cmd.Stdout = &out
-		err := cmd.Run()
 		if err != nil {
 			return "", err
 		}
 
-		if out.String() == "No Instance(s) Available." {
+		if len(ports) == 0 {
 			return "", errors.New("no serial ports available")
+		} else if len(ports) > 1 {
+			return "", errors.New("multiple serial ports available - use -port flag")
 		}
 
-		for _, line := range strings.Split(out.String(), "\n") {
+		return ports[0], nil
-			words := strings.Fields(line)
-			if len(words) == 1 {
-				if strings.Contains(words[0], "COM") {
-					return words[0], nil
-				}
-			}
-		}
-		return "", errors.New("unable to locate a serial port")
 	default:
 		return "", errors.New("unable to search for a default USB device to be flashed on this OS")
 	}
@@ -643,7 +646,7 @@ func getDefaultPort() (port string, err error) {
 
 func usage() {
 	fmt.Fprintln(os.Stderr, "TinyGo is a Go compiler for small places.")
-	fmt.Fprintln(os.Stderr, "version:", version)
+	fmt.Fprintln(os.Stderr, "version:", goenv.Version)
 	fmt.Fprintf(os.Stderr, "usage: %s command [-printir] [-target=<target>] -o <output> <input>\n", os.Args[0])
 	fmt.Fprintln(os.Stderr, "\ncommands:")
 	fmt.Fprintln(os.Stderr, "  build: compile packages and dependencies")
@@ -652,12 +655,27 @@ func usage() {
 	fmt.Fprintln(os.Stderr, "  flash: compile and flash to the device")
 	fmt.Fprintln(os.Stderr, "  gdb:   run/flash and immediately enter GDB")
 	fmt.Fprintln(os.Stderr, "  env:   list environment variables used during build")
+	fmt.Fprintln(os.Stderr, "  list:  run go list using the TinyGo root")
 	fmt.Fprintln(os.Stderr, "  clean: empty cache directory ("+goenv.Get("GOCACHE")+")")
 	fmt.Fprintln(os.Stderr, "  help:  print this help text")
 	fmt.Fprintln(os.Stderr, "\nflags:")
 	flag.PrintDefaults()
 }
 
+// try to make the path relative to the current working directory. If any error
+// occurs, this error is ignored and the absolute path is returned instead.
+func tryToMakePathRelative(dir string) string {
+	wd, err := os.Getwd()
+	if err != nil {
+		return dir
+	}
+	relpath, err := filepath.Rel(wd, dir)
+	if err != nil {
+		return dir
+	}
+	return relpath
+}
+
 // printCompilerError prints compiler errors using the provided logger function
 // (similar to fmt.Println).
 //
@@ -665,8 +683,24 @@ func usage() {
 // to limitations in the LLVM bindings.
 func printCompilerError(logln func(...interface{}), err error) {
 	switch err := err.(type) {
-	case types.Error, scanner.Error:
+	case types.Error:
+		printCompilerError(logln, scanner.Error{
+			Pos: err.Fset.Position(err.Pos),
+			Msg: err.Msg,
+		})
+	case scanner.Error:
+		if !strings.HasPrefix(err.Pos.Filename, filepath.Join(goenv.Get("GOROOT"), "src")) && !strings.HasPrefix(err.Pos.Filename, filepath.Join(goenv.Get("TINYGOROOT"), "src")) {
+			// This file is not from the standard library (either the GOROOT or
+			// the TINYGOROOT). Make the path relative, for easier reading.
+			// Ignore any errors in the process (falling back to the absolute
+			// path).
+			err.Pos.Filename = tryToMakePathRelative(err.Pos.Filename)
+		}
 		logln(err)
+	case scanner.ErrorList:
+		for _, scannerErr := range err {
+			printCompilerError(logln, *scannerErr)
+		}
 	case *interp.Error:
 		logln("#", err.ImportPath)
 		logln(err.Error())
@@ -685,11 +719,17 @@ func printCompilerError(logln func(...interface{}), err error) {
 	case loader.Errors:
 		logln("#", err.Pkg.ImportPath)
 		for _, err := range err.Errs {
-			logln(err)
+			printCompilerError(logln, err)
+		}
+	case loader.Error:
+		logln(err.Err.Error())
+		logln("package", err.ImportStack[0])
+		for _, pkgPath := range err.ImportStack[1:] {
+			logln("\timports", pkgPath)
 		}
 	case *builder.MultiError:
 		for _, err := range err.Errs {
-			logln(err)
+			printCompilerError(logln, err)
 		}
 	default:
 		logln("error:", err)
@@ -706,17 +746,25 @@ func handleCompilerError(err error) {
 }
 
 func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, "No command-line arguments supplied.")
+		usage()
+		os.Exit(1)
+	}
+	command := os.Args[1]
+
 	outpath := flag.String("o", "", "output filename")
 	opt := flag.String("opt", "z", "optimization level: 0, 1, 2, s, z")
 	gc := flag.String("gc", "", "garbage collector to use (none, leaking, extalloc, conservative)")
 	panicStrategy := flag.String("panic", "print", "panic strategy (print, trap)")
-	scheduler := flag.String("scheduler", "", "which scheduler to use (coroutines, tasks)")
+	scheduler := flag.String("scheduler", "", "which scheduler to use (none, coroutines, tasks)")
 	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")
 	tags := flag.String("tags", "", "a space-separated list of extra build tags")
 	target := flag.String("target", "", "LLVM target | .json file with TargetSpec")
 	printSize := flag.String("size", "", "print sizes (none, short, full)")
+	printStacks := flag.Bool("print-stacks", false, "print stack sizes of goroutines")
 	nodebug := flag.Bool("no-debug", false, "disable DWARF debug symbol generation")
 	ocdOutput := flag.Bool("ocd-output", false, "print OCD daemon output during debug")
 	port := flag.String("port", "", "flash port")
@@ -726,12 +774,11 @@ func main() {
 	wasmAbi := flag.String("wasm-abi", "js", "WebAssembly ABI conventions: js (no i64 params) or generic")
 	heapSize := flag.String("heap-size", "1M", "default heap size in bytes (only supported by WebAssembly)")
 
-	if len(os.Args) < 2 {
+	var flagJSON, flagDeps *bool
-		fmt.Fprintln(os.Stderr, "No command-line arguments supplied.")
+	if command == "list" {
-		usage()
+		flagJSON = flag.Bool("json", false, "print data in JSON format")
-		os.Exit(1)
+		flagDeps = flag.Bool("deps", false, "")
 	}
-	command := os.Args[1]
 
 	// Early command processing, before commands are interpreted by the Go flag
 	// library.
@@ -757,6 +804,7 @@ func main() {
 		VerifyIR:      *verifyIR,
 		Debug:         !*nodebug,
 		PrintSizes:    *printSize,
+		PrintStacks:   *printStacks,
 		Tags:          *tags,
 		WasmAbi:       *wasmAbi,
 		Programmer:    *programmer,
@@ -770,12 +818,6 @@ func main() {
 		options.LDFlags = strings.Split(*ldFlags, " ")
 	}
 
-	if *panicStrategy != "print" && *panicStrategy != "trap" {
-		fmt.Fprintln(os.Stderr, "Panic strategy must be either print or trap.")
-		usage()
-		os.Exit(1)
-	}
-
 	var err error
 	if options.HeapSize, err = parseSize(*heapSize); err != nil {
 		fmt.Fprintln(os.Stderr, "Could not read heap size:", *heapSize)
@@ -785,6 +827,13 @@ func main() {
 
 	os.Setenv("CC", "clang -target="+*target)
 
+	err = options.Verify()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		usage()
+		os.Exit(1)
+	}
+
 	switch command {
 	case "build":
 		if *outpath == "" {
@@ -794,7 +843,7 @@ func main() {
 		}
 		pkgName := "."
 		if flag.NArg() == 1 {
-			pkgName = flag.Arg(0)
+			pkgName = filepath.ToSlash(flag.Arg(0))
 		} else if flag.NArg() > 1 {
 			fmt.Fprintln(os.Stderr, "build only accepts a single positional argument: package name, but multiple were specified")
 			usage()
@@ -803,6 +852,7 @@ func main() {
 		if options.Target == "" && filepath.Ext(*outpath) == ".wasm" {
 			options.Target = "wasm"
 		}
+
 		err := Build(pkgName, *outpath, options)
 		handleCompilerError(err)
 	case "build-library":
@@ -839,8 +889,9 @@ func main() {
 			usage()
 			os.Exit(1)
 		}
+		pkgName := filepath.ToSlash(flag.Arg(0))
 		if command == "flash" {
-			err := Flash(flag.Arg(0), *port, options)
+			err := Flash(pkgName, *port, options)
 			handleCompilerError(err)
 		} else {
 			if !options.Debug {
@@ -848,7 +899,7 @@ func main() {
 				usage()
 				os.Exit(1)
 			}
-			err := FlashGDB(flag.Arg(0), *ocdOutput, options)
+			err := FlashGDB(pkgName, *ocdOutput, options)
 			handleCompilerError(err)
 		}
 	case "run":
@@ -857,12 +908,13 @@ func main() {
 			usage()
 			os.Exit(1)
 		}
-		err := Run(flag.Arg(0), options)
+		pkgName := filepath.ToSlash(flag.Arg(0))
+		err := Run(pkgName, options)
 		handleCompilerError(err)
 	case "test":
 		pkgName := "."
 		if flag.NArg() == 1 {
-			pkgName = flag.Arg(0)
+			pkgName = filepath.ToSlash(flag.Arg(0))
 		} else if flag.NArg() > 1 {
 			fmt.Fprintln(os.Stderr, "test only accepts a single positional argument: package name, but multiple were specified")
 			usage()
@@ -870,6 +922,35 @@ func main() {
 		}
 		err := Test(pkgName, options)
 		handleCompilerError(err)
+	case "targets":
+		dir := filepath.Join(goenv.Get("TINYGOROOT"), "targets")
+		entries, err := ioutil.ReadDir(dir)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "could not list targets:", err)
+			os.Exit(1)
+			return
+		}
+		for _, entry := range entries {
+			if !entry.Mode().IsRegular() || !strings.HasSuffix(entry.Name(), ".json") {
+				// Only inspect JSON files.
+				continue
+			}
+			path := filepath.Join(dir, entry.Name())
+			spec, err := compileopts.LoadTarget(path)
+			if err != nil {
+				fmt.Fprintln(os.Stderr, "could not list target:", err)
+				os.Exit(1)
+				return
+			}
+			if spec.FlashMethod == "" && spec.FlashCommand == "" && spec.Emulator == nil {
+				// This doesn't look like a regular target file, but rather like
+				// a parent target (such as targets/cortex-m.json).
+				continue
+			}
+			name := entry.Name()
+			name = name[:len(name)-5]
+			fmt.Println(name)
+		}
 	case "info":
 		if flag.NArg() == 1 {
 			options.Target = flag.Arg(0)
@@ -889,12 +970,50 @@ func main() {
 			fmt.Fprintln(os.Stderr, err)
 			os.Exit(1)
 		}
+		cachedGOROOT, err := loader.GetCachedGoroot(config)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
 		fmt.Printf("LLVM triple:       %s\n", config.Triple())
 		fmt.Printf("GOOS:              %s\n", config.GOOS())
 		fmt.Printf("GOARCH:            %s\n", config.GOARCH())
 		fmt.Printf("build tags:        %s\n", strings.Join(config.BuildTags(), " "))
 		fmt.Printf("garbage collector: %s\n", config.GC())
 		fmt.Printf("scheduler:         %s\n", config.Scheduler())
+		fmt.Printf("cached GOROOT:     %s\n", cachedGOROOT)
+	case "list":
+		config, err := builder.NewConfig(options)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			usage()
+			os.Exit(1)
+		}
+		var extraArgs []string
+		if *flagJSON {
+			extraArgs = append(extraArgs, "-json")
+		}
+		if *flagDeps {
+			extraArgs = append(extraArgs, "-deps")
+		}
+		cmd, err := loader.List(config, extraArgs, flag.Args())
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "failed to run `go list`:", err)
+			os.Exit(1)
+		}
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err = cmd.Run()
+		if err != nil {
+			if exitErr, ok := err.(*exec.ExitError); ok {
+				if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+					os.Exit(status.ExitStatus())
+				}
+				os.Exit(1)
+			}
+			fmt.Fprintln(os.Stderr, "failed to run `go list`:", err)
+			os.Exit(1)
+		}
 	case "clean":
 		// remove cache directory
 		err := os.RemoveAll(goenv.Get("GOCACHE"))
@@ -906,9 +1025,13 @@ func main() {
 		usage()
 	case "version":
 		goversion := "<unknown>"
-		if s, err := builder.GorootVersionString(goenv.Get("GOROOT")); err == nil {
+		if s, err := goenv.GorootVersionString(goenv.Get("GOROOT")); err == nil {
 			goversion = s
 		}
+		version := goenv.Version
+		if strings.HasSuffix(goenv.Version, "-dev") && gitSha1 != "" {
+			version += "-" + 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":
 		if flag.NArg() == 0 {

main_test.go

@@ -6,6 +6,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"flag"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -25,6 +26,8 @@ import (
 
 const TESTDATA = "testdata"
 
+var testTarget = flag.String("target", "", "override test target")
+
 func TestCompiler(t *testing.T) {
 	matches, err := filepath.Glob(filepath.Join(TESTDATA, "*.go"))
 	if err != nil {
@@ -44,6 +47,14 @@ func TestCompiler(t *testing.T) {
 
 	sort.Strings(matches)
 
+	if *testTarget != "" {
+		// This makes it possible to run one specific test (instead of all),
+		// which is especially useful to quickly check whether some changes
+		// affect a particular target architecture.
+		runPlatTests(*testTarget, matches, t)
+		return
+	}
+
 	if runtime.GOOS != "windows" {
 		t.Run("Host", func(t *testing.T) {
 			runPlatTests("", matches, t)
@@ -73,7 +84,7 @@ func TestCompiler(t *testing.T) {
 		t.Run("ARM64Linux", func(t *testing.T) {
 			runPlatTests("aarch64--linux-gnu", matches, t)
 		})
-		goVersion, err := builder.GorootVersionString(goenv.Get("GOROOT"))
+		goVersion, err := goenv.GorootVersionString(goenv.Get("GOROOT"))
 		if err != nil {
 			t.Error("could not get Go version:", err)
 			return
@@ -146,7 +157,7 @@ func runTest(path, target string, t *testing.T) {
 		PrintIR:    false,
 		DumpSSA:    false,
 		VerifyIR:   true,
-		Debug:      false,
+		Debug:      true,
 		PrintSizes: "",
 		WasmAbi:    "js",
 	}

src/device/arm/arm.go

@@ -174,6 +174,11 @@ func EnableIRQ(irq uint32) {
 	NVIC.ISER[irq>>5].Set(1 << (irq & 0x1F))
 }
 
+// Disable the given interrupt number.
+func DisableIRQ(irq uint32) {
+	NVIC.ICER[irq>>5].Set(1 << (irq & 0x1F))
+}
+
 // Set the priority of the given interrupt number.
 // Note that the priority is given as a 0-255 number, where some of the lower
 // bits are not implemented by the hardware. For example, to set a low interrupt
@@ -196,7 +201,7 @@ func SetPriority(irq uint32, priority uint32) {
 func DisableInterrupts() uintptr {
 	return AsmFull(`
 		mrs {}, PRIMASK
-		cpsid if
+		cpsid i
 	`, nil)
 }
 

src/device/arm/cortexm.s

@@ -1,9 +1,11 @@
 .syntax unified
+.cfi_sections .debug_frame
 
 .section .text.HardFault_Handler
 .global  HardFault_Handler
 .type    HardFault_Handler, %function
 HardFault_Handler:
+    .cfi_startproc
     // Put the old stack pointer in the first argument, for easy debugging. This
     // is especially useful on Cortex-M0, which supports far fewer debug
     // facilities.
@@ -19,6 +21,8 @@ HardFault_Handler:
 
     // Continue handling this error in Go.
     bl handleHardFault
+    .cfi_endproc
+.size HardFault_Handler, .-HardFault_Handler
 
 // This is a convenience function for semihosting support.
 // At some point, this should be replaced by inline assembly.
@@ -26,5 +30,8 @@ HardFault_Handler:
 .global  SemihostingCall
 .type    SemihostingCall, %function
 SemihostingCall:
+    .cfi_startproc
     bkpt 0xab
     bx   lr
+    .cfi_endproc
+.size SemihostingCall, .-SemihostingCall

src/device/asm.go

@@ -0,0 +1,21 @@
+package device
+
+// Run the given assembly code. The code will be marked as having side effects,
+// as it doesn't produce output and thus would normally be eliminated by the
+// optimizer.
+func Asm(asm string)
+
+// Run the given inline assembly. The code will be marked as having side
+// effects, as it would otherwise be optimized away. The inline assembly string
+// recognizes template values in the form {name}, like so:
+//
+//     arm.AsmFull(
+//         "str {value}, {result}",
+//         map[string]interface{}{
+//             "value":  1
+//             "result": &dest,
+//         })
+//
+// You can use {} in the asm string (which expands to a register) to set the
+// return value.
+func AsmFull(asm string, regs map[string]interface{}) uintptr

src/device/esp/esp32.S

@@ -0,0 +1,52 @@
+
+// The following definitions were copied from:
+// esp-idf/components/xtensa/include/xtensa/corebits.h
+#define PS_WOE_MASK                0x00040000
+#define PS_OWB_MASK                0x00000F00
+#define PS_CALLINC_MASK            0x00030000
+#define PS_WOE                     PS_WOE_MASK
+
+// Only calling it call_start_cpu0 for consistency with ESP-IDF.
+.section .text.call_start_cpu0
+1:
+    .long _stack_top
+.global call_start_cpu0
+call_start_cpu0:
+    // We need to set the stack pointer to a different value. This is somewhat
+    // complicated in the Xtensa architecture. The code below is a modified
+    // version of the following code:
+    // https://github.com/espressif/esp-idf/blob/c77c4ccf/components/xtensa/include/xt_instr_macros.h#L47
+
+    // Disable WOE.
+    rsr.ps a2
+    movi a3, ~(PS_WOE_MASK)
+    and a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Set WINDOWBASE to 1 << WINDOWSTART.
+    rsr.windowbase  a2
+    ssl  a2
+    movi a2, 1
+    sll  a2, a2
+    wsr.windowstart a2
+    rsync
+
+    // Load new stack pointer.
+    l32r sp, 1b
+
+    // Re-enable WOE.
+    rsr.ps a2
+    movi a3, PS_WOE
+    or a2, a2, a3
+    wsr.ps a2
+    rsync
+
+    // Jump to the runtime start function written in Go.
+    j main
+
+.section .text.tinygo_scanCurrentStack
+.global tinygo_scanCurrentStack
+tinygo_scanCurrentStack:
+    // TODO: save callee saved registers on the stack
+    j tinygo_scanstack

src/device/esp/esp8266.S

@@ -0,0 +1,6 @@
+
+.section .text.tinygo_scanCurrentStack
+.global tinygo_scanCurrentStack
+tinygo_scanCurrentStack:
+    // TODO: save callee saved registers on the stack
+    j tinygo_scanstack

src/device/riscv/handleinterrupt.S

@@ -0,0 +1,130 @@
+#ifdef __riscv_flen
+#define NREG 48
+#define LFREG flw
+#define SFREG fsw
+#else
+#define NREG 16
+#endif
+
+#if __riscv_xlen==64
+#define REGSIZE 8
+#define SREG sd
+#define LREG ld
+#else
+#define REGSIZE 4
+#define SREG sw
+#define LREG lw
+#endif
+
+.section .text.handleInterruptASM
+.global handleInterruptASM
+.type handleInterruptASM,@function
+handleInterruptASM:
+    // Save and restore all registers, because the hardware only saves/restores
+    // the pc.
+    // Note: we have to do this in assembly because the "interrupt"="machine"
+    // attribute is broken in LLVM: https://bugs.llvm.org/show_bug.cgi?id=42984
+    addi    sp, sp, -NREG*REGSIZE
+    SREG    ra, 0*REGSIZE(sp)
+    SREG    t0, 1*REGSIZE(sp)
+    SREG    t1, 2*REGSIZE(sp)
+    SREG    t2, 3*REGSIZE(sp)
+    SREG    a0, 4*REGSIZE(sp)
+    SREG    a1, 5*REGSIZE(sp)
+    SREG    a2, 6*REGSIZE(sp)
+    SREG    a3, 7*REGSIZE(sp)
+    SREG    a4, 8*REGSIZE(sp)
+    SREG    a5, 9*REGSIZE(sp)
+    SREG    a6, 10*REGSIZE(sp)
+    SREG    a7, 11*REGSIZE(sp)
+    SREG    t3, 12*REGSIZE(sp)
+    SREG    t4, 13*REGSIZE(sp)
+    SREG    t5, 14*REGSIZE(sp)
+    SREG    t6, 15*REGSIZE(sp)
+#ifdef __riscv_flen
+    SFREG   f0, (0  + 16)*REGSIZE(sp)
+    SFREG   f1, (1  + 16)*REGSIZE(sp)
+    SFREG   f2, (2  + 16)*REGSIZE(sp)
+    SFREG   f3, (3  + 16)*REGSIZE(sp)
+    SFREG   f4, (4  + 16)*REGSIZE(sp)
+    SFREG   f5, (5  + 16)*REGSIZE(sp)
+    SFREG   f6, (6  + 16)*REGSIZE(sp)
+    SFREG   f7, (7  + 16)*REGSIZE(sp)
+    SFREG   f8, (8  + 16)*REGSIZE(sp)
+    SFREG   f9, (9  + 16)*REGSIZE(sp)
+    SFREG   f10,(10 + 16)*REGSIZE(sp)
+    SFREG   f11,(11 + 16)*REGSIZE(sp)
+    SFREG   f12,(12 + 16)*REGSIZE(sp)
+    SFREG   f13,(13 + 16)*REGSIZE(sp)
+    SFREG   f14,(14 + 16)*REGSIZE(sp)
+    SFREG   f15,(15 + 16)*REGSIZE(sp)
+    SFREG   f16,(16 + 16)*REGSIZE(sp)
+    SFREG   f17,(17 + 16)*REGSIZE(sp)
+    SFREG   f18,(18 + 16)*REGSIZE(sp)
+    SFREG   f19,(19 + 16)*REGSIZE(sp)
+    SFREG   f20,(20 + 16)*REGSIZE(sp)
+    SFREG   f21,(21 + 16)*REGSIZE(sp)
+    SFREG   f22,(22 + 16)*REGSIZE(sp)
+    SFREG   f23,(23 + 16)*REGSIZE(sp)
+    SFREG   f24,(24 + 16)*REGSIZE(sp)
+    SFREG   f25,(25 + 16)*REGSIZE(sp)
+    SFREG   f26,(26 + 16)*REGSIZE(sp)
+    SFREG   f27,(27 + 16)*REGSIZE(sp)
+    SFREG   f28,(28 + 16)*REGSIZE(sp)
+    SFREG   f29,(29 + 16)*REGSIZE(sp)
+    SFREG   f30,(30 + 16)*REGSIZE(sp)
+    SFREG   f31,(31 + 16)*REGSIZE(sp)
+#endif
+    call    handleInterrupt
+#ifdef __riscv_flen
+    LFREG   f0, (31 + 16)*REGSIZE(sp)
+    LFREG   f1, (30 + 16)*REGSIZE(sp)
+    LFREG   f2, (29 + 16)*REGSIZE(sp)
+    LFREG   f3, (28 + 16)*REGSIZE(sp)
+    LFREG   f4, (27 + 16)*REGSIZE(sp)
+    LFREG   f5, (26 + 16)*REGSIZE(sp)
+    LFREG   f6, (25 + 16)*REGSIZE(sp)
+    LFREG   f7, (24 + 16)*REGSIZE(sp)
+    LFREG   f8, (23 + 16)*REGSIZE(sp)
+    LFREG   f9, (22 + 16)*REGSIZE(sp)
+    LFREG   f10,(21 + 16)*REGSIZE(sp)
+    LFREG   f11,(20 + 16)*REGSIZE(sp)
+    LFREG   f12,(19 + 16)*REGSIZE(sp)
+    LFREG   f13,(18 + 16)*REGSIZE(sp)
+    LFREG   f14,(17 + 16)*REGSIZE(sp)
+    LFREG   f15,(16 + 16)*REGSIZE(sp)
+    LFREG   f16,(15 + 16)*REGSIZE(sp)
+    LFREG   f17,(14 + 16)*REGSIZE(sp)
+    LFREG   f18,(13 + 16)*REGSIZE(sp)
+    LFREG   f19,(12 + 16)*REGSIZE(sp)
+    LFREG   f20,(11 + 16)*REGSIZE(sp)
+    LFREG   f21,(10 + 16)*REGSIZE(sp)
+    LFREG   f22,(9 + 16)*REGSIZE(sp)
+    LFREG   f23,(8 + 16)*REGSIZE(sp)
+    LFREG   f24,(7 + 16)*REGSIZE(sp)
+    LFREG   f25,(6 + 16)*REGSIZE(sp)
+    LFREG   f26,(5 + 16)*REGSIZE(sp)
+    LFREG   f27,(4 + 16)*REGSIZE(sp)
+    LFREG   f28,(3 + 16)*REGSIZE(sp)
+    LFREG   f29,(2 + 16)*REGSIZE(sp)
+    LFREG   f30,(1 + 16)*REGSIZE(sp)
+    LFREG   f31,(0 + 16)*REGSIZE(sp)
+#endif
+    LREG    t6, 15*REGSIZE(sp)
+    LREG    t5, 14*REGSIZE(sp)
+    LREG    t4, 13*REGSIZE(sp)
+    LREG    t3, 12*REGSIZE(sp)
+    LREG    a7, 11*REGSIZE(sp)
+    LREG    a6, 10*REGSIZE(sp)
+    LREG    a5, 9*REGSIZE(sp)
+    LREG    a4, 8*REGSIZE(sp)
+    LREG    a3, 7*REGSIZE(sp)
+    LREG    a2, 6*REGSIZE(sp)
+    LREG    a1, 5*REGSIZE(sp)
+    LREG    a0, 4*REGSIZE(sp)
+    LREG    t2, 3*REGSIZE(sp)
+    LREG    t1, 2*REGSIZE(sp)
+    LREG    t0, 1*REGSIZE(sp)
+    LREG    ra, 0*REGSIZE(sp)
+    addi    sp, sp, NREG*REGSIZE
+    mret

src/device/riscv/riscv.go

@@ -19,3 +19,19 @@ func Asm(asm string)
 // You can use {} in the asm string (which expands to a register) to set the
 // return value.
 func AsmFull(asm string, regs map[string]interface{}) uintptr
+
+// DisableInterrupts disables all interrupts, and returns the old interrupt
+// state.
+func DisableInterrupts() uintptr {
+	// Note: this can be optimized with a CSRRW instruction, which atomically
+	// swaps the value and returns the old value.
+	mask := MIE.Get()
+	MIE.Set(0)
+	return mask
+}
+
+// EnableInterrupts enables all interrupts again. The value passed in must be
+// the mask returned by DisableInterrupts.
+func EnableInterrupts(mask uintptr) {
+	MIE.Set(mask)
+}

src/device/riscv/start.S

@@ -9,52 +9,12 @@ _start:
     // Load the globals pointer. The program will load pointers relative to this
     // register, so it must be set to the right value on startup.
     // See: https://gnu-mcu-eclipse.github.io/arch/riscv/programmer/#the-gp-global-pointer-register
+    // Linker relaxations must be disabled to avoid the initialization beign
+    // relaxed with an uninitialized global pointer: mv gp, gp
+    .option push
+    .option norelax
     la gp,      __global_pointer$
+    .option pop
 
     // Jump to runtime.main
     call main
-
-.section .text.handleInterruptASM
-.global handleInterruptASM
-.type handleInterruptASM,@function
-handleInterruptASM:
-    // Save and restore all registers, because the hardware only saves/restores
-    // the pc.
-    // Note: we have to do this in assembly because the "interrupt"="machine"
-    // attribute is broken in LLVM: https://bugs.llvm.org/show_bug.cgi?id=42984
-    addi    sp, sp, -64
-    sw      ra, 60(sp)
-    sw      t0, 56(sp)
-    sw      t1, 52(sp)
-    sw      t2, 48(sp)
-    sw      a0, 44(sp)
-    sw      a1, 40(sp)
-    sw      a2, 36(sp)
-    sw      a3, 32(sp)
-    sw      a4, 28(sp)
-    sw      a5, 24(sp)
-    sw      a6, 20(sp)
-    sw      a7, 16(sp)
-    sw      t3, 12(sp)
-    sw      t4, 8(sp)
-    sw      t5, 4(sp)
-    sw      t6, 0(sp)
-    call    handleInterrupt
-    lw      t6, 0(sp)
-    lw      t5, 4(sp)
-    lw      t4, 8(sp)
-    lw      t3, 12(sp)
-    lw      a7, 16(sp)
-    lw      a6, 20(sp)
-    lw      a5, 24(sp)
-    lw      a4, 28(sp)
-    lw      a3, 32(sp)
-    lw      a2, 36(sp)
-    lw      a1, 40(sp)
-    lw      a0, 44(sp)
-    lw      t2, 48(sp)
-    lw      t1, 52(sp)
-    lw      t0, 56(sp)
-    lw      ra, 60(sp)
-    addi    sp, sp, 64
-    mret

src/device/sam/atsamd51x-bitfields.go

@@ -0,0 +1,71 @@
+// Hand created file. DO NOT DELETE.
+// atsamd51x bitfield definitions that are not auto-generated by gen-device-svd.go
+
+// +build sam,atsamd51
+
+// These are the supported pchctrl function numberings on the atsamd51x
+// See http://ww1.microchip.com/downloads/en/DeviceDoc/SAM_D5xE5x_Family_Data_Sheet_DS60001507F.pdf
+// table 14-9
+
+package sam
+
+const (
+	PCHCTRL_GCLK_OSCCTRL_DFLL48     = 0 // DFLL48 input clock source
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0     = 1 // Reference clock for FDPLL0
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1     = 2 // Reference clock for FDPLL1
+	PCHCTRL_GCLK_OSCCTRL_FDPLL0_32K = 3 // FDPLL0 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_OSCCTRL_FDPLL1_32K = 3 // FDPLL1 = 3 // 32KHz clock for internal lock timer
+	PCHCTRL_GCLK_SDHC0_SLOW         = 3 // SDHC0 = 3 // Slow
+	PCHCTRL_GCLK_SDHC1_SLOW         = 3 // SDHC1 = 3 // Slow
+	PCHCTRL_GCLK_SERCOMX_SLOW       = 3 // GCLK_SERCOM[0..7]_SLOW = 3
+	PCHCTRL_GCLK_EIC                = 4
+	PCHCTRL_GCLK_FREQM_MSR          = 5 // FREQM Measure
+	PCHCTRL_GCLK_FREQM_REF          = 6 // FREQM Reference
+	PCHCTRL_GCLK_SERCOM0_CORE       = 7 // SERCOM0 Core
+	PCHCTRL_GCLK_SERCOM1_CORE       = 8 // SERCOM1 Core
+	PCHCTRL_GCLK_TC0                = 9
+	PCHCTRL_GCLK_TC1                = 9  // TC0, TC1
+	PCHCTRL_GCLK_USB                = 10 // USB
+	PCHCTRL_GCLK_EVSYS0             = 11
+	PCHCTRL_GCLK_EVSYS1             = 12
+	PCHCTRL_GCLK_EVSYS2             = 13
+	PCHCTRL_GCLK_EVSYS3             = 14
+	PCHCTRL_GCLK_EVSYS4             = 15
+	PCHCTRL_GCLK_EVSYS5             = 16
+	PCHCTRL_GCLK_EVSYS6             = 17
+	PCHCTRL_GCLK_EVSYS7             = 18
+	PCHCTRL_GCLK_EVSYS8             = 19
+	PCHCTRL_GCLK_EVSYS9             = 20
+	PCHCTRL_GCLK_EVSYS10            = 21
+	PCHCTRL_GCLK_EVSYS11            = 22
+	PCHCTRL_GCLK_SERCOM2_CORE       = 23 // SERCOM2 Core
+	PCHCTRL_GCLK_SERCOM3_CORE       = 24 // SERCOM3 Core
+	PCHCTRL_GCLK_TCC0               = 25
+	PCHCTRL_GCLK_TCC1               = 25 // TCC0, TCC1
+	PCHCTRL_GCLK_TC2                = 26
+	PCHCTRL_GCLK_TC3                = 26 // TC2, TC3
+	PCHCTRL_GCLK_CAN0               = 27 // CAN0
+	PCHCTRL_GCLK_CAN1               = 28 // CAN1
+	PCHCTRL_GCLK_TCC2               = 29
+	PCHCTRL_GCLK_TCC3               = 29 // TCC2, TCC3
+	PCHCTRL_GCLK_TC4                = 30
+	PCHCTRL_GCLK_TC5                = 30 // TC4, TC5
+	PCHCTRL_GCLK_PDEC               = 31 // PDEC
+	PCHCTRL_GCLK_AC                 = 32 // AC
+	PCHCTRL_GCLK_CCL                = 33 // CCL
+	PCHCTRL_GCLK_SERCOM4_CORE       = 34 // SERCOM4 Core
+	PCHCTRL_GCLK_SERCOM5_CORE       = 35 // SERCOM5 Core
+	PCHCTRL_GCLK_SERCOM6_CORE       = 36 // SERCOM6 Core
+	PCHCTRL_GCLK_SERCOM7_CORE       = 37 // SERCOM7 Core
+	PCHCTRL_GCLK_TCC4               = 38 // TCC4
+	PCHCTRL_GCLK_TC6                = 39
+	PCHCTRL_GCLK_TC7                = 39 // TC6, TC7
+	PCHCTRL_GCLK_ADC0               = 40 // ADC0
+	PCHCTRL_GCLK_ADC1               = 41 // ADC1
+	PCHCTRL_GCLK_DAC                = 42 // DAC
+	PCHCTRL_GCLK_I2S0               = 43
+	PCHCTRL_GCLK_I2S1               = 44
+	PCHCTRL_GCLK_SDHC0              = 45 // SDHC0
+	PCHCTRL_GCLK_SDHC1              = 46 // SDHC1
+	PCHCTRL_GCLK_CM4_TRACE          = 47 // CM4 Trace
+)

src/device/stm32/stm32f4-altfunc-bitfields.go

@@ -1,7 +1,9 @@
-// These are the supported alternate function numberings on the stm32f407
+// Hand created file. DO NOT DELETE.
-// +build stm32,stm32f407
+// STM32FXXX (except stm32f1xx) bitfield definitions that are not
+//  auto-generated by gen-device-svd.go
+// +build stm32f4
 
-// Alternate function settings on the stm32f4xx series
+// Alternate function settings on the stm32f4 series
 
 package stm32
 

src/examples/button/button.go

@@ -5,16 +5,14 @@ import (
 	"time"
 )
 
-// This example assumes that the button is connected to pin 8. Change the value
-// below to use a different pin.
 const (
 	led    = machine.LED
-	button = machine.Pin(8)
+	button = machine.BUTTON
 )
 
 func main() {
 	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	button.Configure(machine.PinConfig{Mode: machine.PinInput})
+	button.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 
 	for {
 		if button.Get() {

src/examples/dac/circuitplay_express.go

@@ -0,0 +1,13 @@
+// +build circuitplay_express
+
+package main
+
+import (
+	"machine"
+)
+
+func init() {
+	enable := machine.PA30
+	enable.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	enable.Set(true)
+}

src/examples/dac/dac.go

@@ -0,0 +1,36 @@
+// Simplistic example using the DAC on the Circuit Playground Express.
+//
+// To actually use the DAC for producing complex waveforms or samples requires a DMA
+// timer-based playback mechanism which is beyond the scope of this example.
+package main
+
+import (
+	"machine"
+	"time"
+)
+
+func main() {
+	speaker := machine.A0
+	speaker.Configure(machine.PinConfig{Mode: machine.PinOutput})
+
+	machine.DAC0.Configure(machine.DACConfig{})
+
+	data := []uint16{0xFFFF, 0x8000, 0x4000, 0x2000, 0x1000, 0x0000}
+
+	for {
+		for _, val := range data {
+			play(val)
+			time.Sleep(500 * time.Millisecond)
+		}
+	}
+}
+
+func play(val uint16) {
+	for i := 0; i < 100; i++ {
+		machine.DAC0.Set(val)
+		time.Sleep(2 * time.Millisecond)
+
+		machine.DAC0.Set(0)
+		time.Sleep(2 * time.Millisecond)
+	}
+}

src/examples/dac/pyportal.go

@@ -0,0 +1,13 @@
+// +build pyportal
+
+package main
+
+import (
+	"machine"
+)
+
+func init() {
+	enable := machine.SPK_SD
+	enable.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	enable.Set(true)
+}

src/examples/pininterrupt/circuitplay-express.go

@@ -0,0 +1,10 @@
+// +build circuitplay_express
+
+package main
+
+import "machine"
+
+const (
+	buttonMode      = machine.PinInputPulldown
+	buttonPinChange = machine.PinFalling
+)

src/examples/pininterrupt/pca10040.go

@@ -0,0 +1,10 @@
+// +build pca10040
+
+package main
+
+import "machine"
+
+const (
+	buttonMode      = machine.PinInputPullup
+	buttonPinChange = machine.PinRising
+)

src/examples/pininterrupt/pininterrupt.go

@@ -0,0 +1,52 @@
+package main
+
+// This example demonstrates how to use pin change interrupts.
+//
+// This is only an example and should not be copied directly in any serious
+// circuit, because it lacks an important feature: debouncing.
+// See: https://en.wikipedia.org/wiki/Switch#Contact_bounce
+
+import (
+	"machine"
+	"runtime/volatile"
+	"time"
+)
+
+const (
+	button = machine.BUTTON
+	led    = machine.LED
+)
+
+func main() {
+	var lightLed volatile.Register8
+	lightLed.Set(0)
+
+	// Configure the LED, defaulting to on (usually setting the pin to low will
+	// turn the LED on).
+	led.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	led.Low()
+
+	// Make sure the pin is configured as a pullup to avoid floating inputs.
+	// Pullup works for most buttons, as most buttons short to ground when
+	// pressed.
+	button.Configure(machine.PinConfig{Mode: buttonMode})
+
+	// Set an interrupt on this pin.
+	err := button.SetInterrupt(buttonPinChange, func(machine.Pin) {
+		if lightLed.Get() != 0 {
+			lightLed.Set(0)
+			led.Low()
+		} else {
+			lightLed.Set(1)
+			led.High()
+		}
+	})
+	if err != nil {
+		println("could not configure pin interrupt:", err.Error())
+	}
+
+	// Make sure the program won't exit.
+	for {
+		time.Sleep(time.Hour)
+	}
+}

src/examples/pininterrupt/wioterminal.go

@@ -0,0 +1,10 @@
+// +build wioterminal
+
+package main
+
+import "machine"
+
+const (
+	buttonMode      = machine.PinInput
+	buttonPinChange = machine.PinFalling
+)

src/examples/pwm/pwm.go

@@ -8,9 +8,9 @@ import (
 // This example assumes that an RGB LED is connected to pins 3, 5 and 6 on an Arduino.
 // Change the values below to use different pins.
 const (
-	redPin   = 3
+	redPin   = machine.D4
-	greenPin = 5
+	greenPin = machine.D5
-	bluePin  = 6
+	bluePin  = machine.D6
 )
 
 // cycleColor is just a placeholder until math/rand or some equivalent is working.
@@ -28,13 +28,16 @@ func main() {
 	machine.InitPWM()
 
 	red := machine.PWM{redPin}
-	red.Configure()
+	err := red.Configure()
+	checkError(err, "failed to configure red pin")
 
 	green := machine.PWM{greenPin}
-	green.Configure()
+	err = green.Configure()
+	checkError(err, "failed to configure green pin")
 
 	blue := machine.PWM{bluePin}
-	blue.Configure()
+	err = blue.Configure()
+	checkError(err, "failed to configure blue pin")
 
 	var rc uint8
 	var gc uint8 = 20
@@ -52,3 +55,10 @@ func main() {
 		time.Sleep(time.Millisecond * 500)
 	}
 }
+
+func checkError(err error, msg string) {
+	if err != nil {
+		print(msg, ": ", err.Error())
+		println()
+	}
+}

src/examples/systick/systick.go

@@ -5,6 +5,8 @@ import (
 	"machine"
 )
 
+var timerCh = make(chan struct{}, 1)
+
 func main() {
 	machine.LED.Configure(machine.PinConfig{Mode: machine.PinOutput})
 
@@ -12,17 +14,18 @@ func main() {
 	arm.SetupSystemTimer(machine.CPUFrequency() / 10)
 
 	for {
+		machine.LED.Low()
+		<-timerCh
+		machine.LED.High()
+		<-timerCh
 	}
 }
 
-var led_state bool
-
 //export SysTick_Handler
 func timer_isr() {
-	if led_state {
+	select {
-		machine.LED.Low()
+	case timerCh <- struct{}{}:
-	} else {
+	default:
-		machine.LED.High()
+		// The consumer is running behind.
 	}
-	led_state = !led_state
 }

src/internal/bytealg/bytealg.go

@@ -0,0 +1,253 @@
+package bytealg
+
+const (
+	// Index can search any valid length of string.
+
+	MaxLen        = int(-1) >> 31
+	MaxBruteForce = MaxLen
+)
+
+// Compare two byte slices.
+// Returns -1 if the first differing byte is lower in a, or 1 if the first differing byte is greater in b.
+// If the byte slices are equal, returns 0.
+// If the lengths are different and there are no differing bytes, compares based on length.
+func Compare(a, b []byte) int {
+	// Compare for differing bytes.
+	for i := 0; i < len(a) && i < len(b); i++ {
+		switch {
+		case a[0] < b[0]:
+			return -1
+		case a[0] > b[0]:
+			return 1
+		}
+	}
+
+	// Compare lengths.
+	switch {
+	case len(a) > len(b):
+		return 1
+	case len(a) < len(b):
+		return -1
+	default:
+		return 0
+	}
+}
+
+// Count the number of instances of a byte in a slice.
+func Count(b []byte, c byte) int {
+	// Use a simple implementation, as there is no intrinsic that does this like we want.
+	n := 0
+	for _, v := range b {
+		if v == c {
+			n++
+		}
+	}
+	return n
+}
+
+// Count the number of instances of a byte in a string.
+func CountString(s string, c byte) int {
+	// Use a simple implementation, as there is no intrinsic that does this like we want.
+	// Currently, the compiler does not generate zero-copy byte-string conversions, so this needs to be seperate from Count.
+	n := 0
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			n++
+		}
+	}
+	return n
+}
+
+// Cutover is not reachable in TinyGo, but must exist as it is referenced.
+func Cutover(n int) int {
+	// Setting MaxLen and MaxBruteForce should force a different path to be taken.
+	// This should never be called.
+	panic("cutover is unreachable")
+}
+
+// Equal checks if two byte slices are equal.
+// It is equivalent to bytes.Equal.
+func Equal(a, b []byte) bool {
+	if len(a) != len(b) {
+		return false
+	}
+
+	for i, v := range a {
+		if v != b[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Index finds the base index of the first instance of the byte sequence b in a.
+// If a does not contain b, this returns -1.
+func Index(a, b []byte) int {
+	for i := 0; i <= len(a)-len(b); i++ {
+		if Equal(a[i:i+len(b)], b) {
+			return i
+		}
+	}
+	return -1
+}
+
+// Index finds the index of the first instance of the specified byte in the slice.
+// If the byte is not found, this returns -1.
+func IndexByte(b []byte, c byte) int {
+	for i, v := range b {
+		if v == c {
+			return i
+		}
+	}
+	return -1
+}
+
+// Index finds the index of the first instance of the specified byte in the string.
+// If the byte is not found, this returns -1.
+func IndexByteString(s string, c byte) int {
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			return i
+		}
+	}
+	return -1
+}
+
+// Index finds the base index of the first instance of a substring in a string.
+// If the substring is not found, this returns -1.
+func IndexString(str, sub string) int {
+	for i := 0; i <= len(str)-len(sub); i++ {
+		if str[i:i+len(sub)] == sub {
+			return i
+		}
+	}
+	return -1
+}
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The following code has been copied from the Go 1.15 release tree.
+
+// PrimeRK is the prime base used in Rabin-Karp algorithm.
+const PrimeRK = 16777619
+
+// HashStrBytes returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStrBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStr returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStr(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRevBytes returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRevBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRev returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRev(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// IndexRabinKarpBytes uses the Rabin-Karp search algorithm to return the index of the
+// first occurence of substr in s, or -1 if not present.
+func IndexRabinKarpBytes(s, sep []byte) int {
+	// Rabin-Karp search
+	hashsep, pow := HashStrBytes(sep)
+	n := len(sep)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashsep && Equal(s[:n], sep) {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashsep && Equal(s[i-n:i], sep) {
+			return i - n
+		}
+	}
+	return -1
+}
+
+// IndexRabinKarp uses the Rabin-Karp search algorithm to return the index of the
+// first occurence of substr in s, or -1 if not present.
+func IndexRabinKarp(s, substr string) int {
+	// Rabin-Karp search
+	hashss, pow := HashStr(substr)
+	n := len(substr)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashss && s[:n] == substr {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashss && s[i-n:i] == substr {
+			return i - n
+		}
+	}
+	return -1
+}

src/internal/task/queue.go

@@ -1,5 +1,7 @@
 package task
 
+import "runtime/interrupt"
+
 const asserts = false
 
 // Queue is a FIFO container of tasks.
@@ -10,7 +12,9 @@ type Queue struct {
 
 // Push a task onto the queue.
 func (q *Queue) Push(t *Task) {
+	i := interrupt.Disable()
 	if asserts && t.Next != nil {
+		interrupt.Restore(i)
 		panic("runtime: pushing a task to a queue with a non-nil Next pointer")
 	}
 	if q.tail != nil {
@@ -21,12 +25,15 @@ func (q *Queue) Push(t *Task) {
 	if q.head == nil {
 		q.head = t
 	}
+	interrupt.Restore(i)
 }
 
 // Pop a task off of the queue.
 func (q *Queue) Pop() *Task {
+	i := interrupt.Disable()
 	t := q.head
 	if t == nil {
+		interrupt.Restore(i)
 		return nil
 	}
 	q.head = t.Next
@@ -34,11 +41,13 @@ func (q *Queue) Pop() *Task {
 		q.tail = nil
 	}
 	t.Next = nil
+	interrupt.Restore(i)
 	return t
 }
 
 // Append pops the contents of another queue and pushes them onto the end of this queue.
 func (q *Queue) Append(other *Queue) {
+	i := interrupt.Disable()
 	if q.head == nil {
 		q.head = other.head
 	} else {
@@ -46,6 +55,15 @@ func (q *Queue) Append(other *Queue) {
 	}
 	q.tail = other.tail
 	other.head, other.tail = nil, nil
+	interrupt.Restore(i)
+}
+
+// Empty checks if the queue is empty.
+func (q *Queue) Empty() bool {
+	i := interrupt.Disable()
+	empty := q.head == nil
+	interrupt.Restore(i)
+	return empty
 }
 
 // Stack is a LIFO container of tasks.
@@ -57,19 +75,24 @@ type Stack struct {
 
 // Push a task onto the stack.
 func (s *Stack) Push(t *Task) {
+	i := interrupt.Disable()
 	if asserts && t.Next != nil {
+		interrupt.Restore(i)
 		panic("runtime: pushing a task to a stack with a non-nil Next pointer")
 	}
 	s.top, t.Next = t, s.top
+	interrupt.Restore(i)
 }
 
 // Pop a task off of the stack.
 func (s *Stack) Pop() *Task {
+	i := interrupt.Disable()
 	t := s.top
 	if t != nil {
 		s.top = t.Next
+		t.Next = nil
 	}
-	t.Next = nil
+	interrupt.Restore(i)
 	return t
 }
 
@@ -89,10 +112,13 @@ func (t *Task) tail() *Task {
 // Queue moves the contents of the stack into a queue.
 // Elements can be popped from the queue in the same order that they would be popped from the stack.
 func (s *Stack) Queue() Queue {
+	i := interrupt.Disable()
 	head := s.top
 	s.top = nil
-	return Queue{
+	q := Queue{
 		head: head,
 		tail: head.tail(),
 	}
+	interrupt.Restore(i)
+	return q
 }

src/internal/task/task.go

@@ -18,3 +18,8 @@ type Task struct {
 	// state is the underlying running state of the task.
 	state state
 }
+
+// getGoroutineStackSize is a compiler intrinsic that returns the stack size for
+// the given function and falls back to the default stack size. It is replaced
+// with a load from a special section just before codegen.
+func getGoroutineStackSize(fn uintptr) uintptr

src/internal/task/task_coroutine.go

@@ -67,7 +67,7 @@ func createTask() *Task {
 // start invokes a function in a new goroutine. Calls to this are inserted by the compiler.
 // The created goroutine starts running immediately.
 // This is implemented inside the compiler.
-func start(fn uintptr, args unsafe.Pointer)
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr)
 
 // Current returns the current active task.
 // This is implemented inside the compiler.

src/internal/task/task_none.go

@@ -17,7 +17,7 @@ func Current() *Task {
 }
 
 //go:noinline
-func start(fn uintptr, args unsafe.Pointer) {
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	// The compiler will error if this is reachable.
 	runtimePanic("scheduler is disabled")
 }

src/internal/task/task_stack.go

@@ -54,7 +54,7 @@ func (t *Task) Resume() {
 }
 
 // initialize the state and prepare to call the specified function with the specified argument bundle.
-func (s *state) initialize(fn uintptr, args unsafe.Pointer) {
+func (s *state) initialize(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	// Create a stack.
 	stack := make([]uintptr, stackSize/unsafe.Sizeof(uintptr(0)))
 
@@ -67,9 +67,9 @@ func runqueuePushBack(*Task)
 
 // start creates and starts a new goroutine with the given function and arguments.
 // The new goroutine is scheduled to run later.
-func start(fn uintptr, args unsafe.Pointer) {
+func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	t := &Task{}
-	t.state.initialize(fn, args)
+	t.state.initialize(fn, args, stackSize)
 	runqueuePushBack(t)
 }
 

src/internal/task/task_stack_avr.go

@@ -4,8 +4,6 @@ package task
 
 import "unsafe"
 
-const stackSize = 256
-
 // calleeSavedRegs is the list of registers that must be saved and restored when
 // switching between tasks. Also see scheduler_avr.S that relies on the
 // exact layout of this struct.

src/internal/task/task_stack_cortexm.go

@@ -4,8 +4,6 @@ package task
 
 import "unsafe"
 
-const stackSize = 1024
-
 // calleeSavedRegs is the list of registers that must be saved and restored when
 // switching between tasks. Also see scheduler_cortexm.S that relies on the
 // exact layout of this struct.

src/machine/board_arduino.go

@@ -7,21 +7,39 @@ func CPUFrequency() uint32 {
 	return 16000000
 }
 
+// Digital pins, marked as plain numbers on the board.
+const (
+	D0  = PD0 // RX
+	D1  = PD1 // TX
+	D2  = PD2
+	D3  = PD3
+	D4  = PD4
+	D5  = PD5
+	D6  = PD6
+	D7  = PD7
+	D8  = PB0
+	D9  = PB1
+	D10 = PB2
+	D11 = PB3
+	D12 = PB4
+	D13 = PB5
+)
+
 // LED on the Arduino
-const LED Pin = 13
+const LED Pin = D13
 
 // ADC on the Arduino
 const (
-	ADC0 Pin = 0
+	ADC0 Pin = PC0
-	ADC1 Pin = 1
+	ADC1 Pin = PC1
-	ADC2 Pin = 2
+	ADC2 Pin = PC2
-	ADC3 Pin = 3
+	ADC3 Pin = PC3
-	ADC4 Pin = 4 // Used by TWI for SDA
+	ADC4 Pin = PC4 // Used by TWI for SDA
-	ADC5 Pin = 5 // Used by TWI for SCL
+	ADC5 Pin = PC5 // Used by TWI for SCL
 )
 
 // UART pins
 const (
-	UART_TX_PIN Pin = 1
+	UART_TX_PIN Pin = PD1
-	UART_RX_PIN Pin = 0
+	UART_RX_PIN Pin = PD0
 )

src/machine/board_arduino_mega2560.go

@@ -49,7 +49,7 @@ const (
 	// Digital pins
 	D0  Pin = PE0
 	D1  Pin = PE1
-	D2  Pin = PE6
+	D2  Pin = PE4
 	D3  Pin = PE5
 	D4  Pin = PG5
 	D5  Pin = PE3

src/machine/board_arduino_nano.go

@@ -7,21 +7,39 @@ func CPUFrequency() uint32 {
 	return 16000000
 }
 
+// Digital pins.
+const (
+	D0  = PD0 // RX0
+	D1  = PD1 // TX1
+	D2  = PD2
+	D3  = PD3
+	D4  = PD4
+	D5  = PD5
+	D6  = PD6
+	D7  = PD7
+	D8  = PB0
+	D9  = PB1
+	D10 = PB2
+	D11 = PB3
+	D12 = PB4
+	D13 = PB5
+)
+
 // LED on the Arduino
-const LED Pin = 13
+const LED Pin = D13
 
 // ADC on the Arduino
 const (
-	ADC0 Pin = 0
+	ADC0 Pin = PC0
-	ADC1 Pin = 1
+	ADC1 Pin = PC1
-	ADC2 Pin = 2
+	ADC2 Pin = PC2
-	ADC3 Pin = 3
+	ADC3 Pin = PC3
-	ADC4 Pin = 4 // Used by TWI for SDA
+	ADC4 Pin = PC4 // Used by TWI for SDA
-	ADC5 Pin = 5 // Used by TWI for SCL
+	ADC5 Pin = PC5 // Used by TWI for SCL
 )
 
 // UART pins
 const (
-	UART_TX_PIN Pin = 1
+	UART_TX_PIN Pin = PD1
-	UART_RX_PIN Pin = 0
+	UART_RX_PIN Pin = PD0
 )

src/machine/board_arduino_nano33.go

@@ -66,15 +66,15 @@ const (
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  Pin = D13 // SCK: SERCOM1/PAD[1]
+	SPI0_SCK_PIN Pin = D13 // SCK: SERCOM1/PAD[1]
-	SPI0_MOSI_PIN Pin = D11 // MOSI: SERCOM1/PAD[0]
+	SPI0_SDO_PIN Pin = D11 // SDO: SERCOM1/PAD[0]
-	SPI0_MISO_PIN Pin = D12 // MISO: SERCOM1/PAD[3]
+	SPI0_SDI_PIN Pin = D12 // SDI: SERCOM1/PAD[3]
 )
 
 // NINA-W102 Pins
 const (
-	NINA_MOSI   Pin = PA12
+	NINA_SDO    Pin = PA12
-	NINA_MISO   Pin = PA13
+	NINA_SDI    Pin = PA13
 	NINA_CS     Pin = PA14
 	NINA_SCK    Pin = PA15
 	NINA_GPIO0  Pin = PA27

src/machine/board_arduino_zero.go

@@ -0,0 +1,101 @@
+// +build sam,atsamd21,arduino_zero
+
+package machine
+
+// used to reset into bootloader
+const RESET_MAGIC_VALUE = 0x07738135
+
+// GPIO Pins - Digital Low
+const (
+	D0 = PA11 // RX
+	D1 = PA10 // TX
+	D2 = PA14
+	D3 = PA09 // PWM available
+	D4 = PA08 // PWM available
+	D5 = PA15 // PWM available
+	D6 = PA20 // PWM available
+	D7 = PA21
+)
+
+// GPIO Pins - Digital High
+const (
+	D8  = PA06 // PWM available
+	D9  = PA07 // PWM available
+	D10 = PA18 // PWM available
+	D11 = PA16 // PWM available
+	D12 = PA19 // PWM available
+	D13 = PA17 // PWM available
+)
+
+// LEDs on the Arduino Zero
+const (
+	LED      = LED1
+	LED1 Pin = D13
+	LED2 Pin = PA27 // TX LED
+	LED3 Pin = PB03 // RX LED
+)
+
+// ADC pins
+const (
+	AREF Pin = PA03
+	ADC0 Pin = PA02
+	ADC1 Pin = PB08
+	ADC2 Pin = PB09
+	ADC3 Pin = PA04
+	ADC4 Pin = PA05
+	ADC5 Pin = PB02
+)
+
+// SPI pins - EDBG connected
+const (
+	SPI0_SDO_PIN Pin = PA16 // MOSI: SERCOM1/PAD[0]
+	SPI0_SDI_PIN Pin = PA19 // MISO: SERCOM1/PAD[2]
+	SPI0_SCK_PIN Pin = PA17 // SCK:  SERCOM1/PAD[3]
+)
+
+// SPI pins (Legacy ICSP)
+const (
+	SPI1_SDO_PIN Pin = PB10 // MOSI: SERCOM4/PAD[2] - Pin 4
+	SPI1_SDI_PIN Pin = PA12 // MISO: SERCOM4/PAD[0] - Pin 1
+	SPI1_SCK_PIN Pin = PB11 // SCK:  SERCOM4/PAD[3] - Pin 3
+)
+
+// I2C pins - EDBG connected
+const (
+	SDA_PIN Pin = PA22 // SDA: SERCOM3/PAD[0] - Pin 20
+	SCL_PIN Pin = PA23 // SCL: SERCOM3/PAD[1] - Pin 21
+)
+
+// I2S pins - might not be exposed
+const (
+	I2S_SCK_PIN Pin = PA10
+	I2S_SD_PIN  Pin = PA07
+	I2S_WS_PIN  Pin = PA11
+)
+
+// UART0 pins - EDBG connected
+const (
+	UART_RX_PIN Pin = D0
+	UART_TX_PIN Pin = D1
+)
+
+// 'native' USB port pins
+const (
+	USBCDC_DM_PIN Pin = PA24
+	USBCDC_DP_PIN Pin = PA25
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Arduino Zero"
+	usb_STRING_MANUFACTURER = "Arduino LLC"
+
+	usb_VID uint16 = 0x2341
+	usb_PID uint16 = 0x804d
+)
+
+// 32.768 KHz Crystal
+const (
+	XIN32  Pin = PA00
+	XOUT32 Pin = PA01
+)

src/machine/board_atmega328p.go

@@ -0,0 +1,37 @@
+// +build avr,atmega328p arduino arduino_nano
+
+package machine
+
+const (
+	// Note: start at port B because there is no port A.
+	portB Pin = iota * 8
+	portC
+	portD
+)
+
+const (
+	PB0 = portB + 0
+	PB1 = portB + 1
+	PB2 = portB + 2
+	PB3 = portB + 3
+	PB4 = portB + 4
+	PB5 = portB + 5
+	PB6 = portB + 6
+	PB7 = portB + 7
+	PC0 = portC + 0
+	PC1 = portC + 1
+	PC2 = portC + 2
+	PC3 = portC + 3
+	PC4 = portC + 4
+	PC5 = portC + 5
+	PC6 = portC + 6
+	PC7 = portC + 7
+	PD0 = portD + 0
+	PD1 = portD + 1
+	PD2 = portD + 2
+	PD3 = portD + 3
+	PD4 = portD + 4
+	PD5 = portD + 5
+	PD6 = portD + 6
+	PD7 = portD + 7
+)

src/machine/board_bluepill.go

@@ -65,18 +65,22 @@ var (
 		Buffer: NewRingBuffer(),
 		Bus:    stm32.USART1,
 	}
-	UART1 = &UART0
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    stm32.USART2,
+	}
 )
 
 func init() {
 	UART0.Interrupt = interrupt.New(stm32.IRQ_USART1, UART0.handleInterrupt)
+	UART1.Interrupt = interrupt.New(stm32.IRQ_USART2, UART1.handleInterrupt)
 }
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  = PA5
+	SPI0_SCK_PIN = PA5
-	SPI0_MOSI_PIN = PA7
+	SPI0_SDO_PIN = PA7
-	SPI0_MISO_PIN = PA6
+	SPI0_SDI_PIN = PA6
 )
 
 // I2C pins

src/machine/board_circuitplay_bluefruit.go

@@ -2,7 +2,7 @@
 
 package machine
 
-const HasLowFrequencyCrystal = true
+const HasLowFrequencyCrystal = false
 
 // GPIO Pins
 const (
@@ -72,9 +72,9 @@ const (
 
 // SPI pins (internal flash)
 const (
-	SPI0_SCK_PIN  = P0_19 // SCK
+	SPI0_SCK_PIN = P0_19 // SCK
-	SPI0_MOSI_PIN = P0_21 // MOSI
+	SPI0_SDO_PIN = P0_21 // SDO
-	SPI0_MISO_PIN = P0_23 // MISO
+	SPI0_SDI_PIN = P0_23 // SDI
 )
 
 // USB CDC identifiers

src/machine/board_circuitplay_express.go

@@ -77,9 +77,9 @@ const (
 
 // SPI pins (internal flash)
 const (
-	SPI0_SCK_PIN  = PA21 // SCK: SERCOM3/PAD[3]
+	SPI0_SCK_PIN = PA21 // SCK: SERCOM3/PAD[3]
-	SPI0_MOSI_PIN = PA20 // MOSI: SERCOM3/PAD[2]
+	SPI0_SDO_PIN = PA20 // SDO: SERCOM3/PAD[2]
-	SPI0_MISO_PIN = PA16 // MISO: SERCOM3/PAD[0]
+	SPI0_SDI_PIN = PA16 // SDI: SERCOM3/PAD[0]
 )
 
 // I2S pins

src/machine/board_clue_alpha.go

@@ -78,7 +78,7 @@ const (
 
 	// 240x240 ST7789 display is connected to these pins (use RowOffset = 80)
 	TFT_SCK   = D29
-	TFT_MOSI  = D30
+	TFT_SDO   = D30
 	TFT_CS    = D31
 	TFT_DC    = D32
 	TFT_RESET = D33
@@ -116,9 +116,9 @@ const (
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  = D13 // SCK
+	SPI0_SCK_PIN = D13 // SCK
-	SPI0_MOSI_PIN = D15 // MOSI
+	SPI0_SDO_PIN = D15 // SDO
-	SPI0_MISO_PIN = D14 // MISO
+	SPI0_SDI_PIN = D14 // SDI
 )
 
 // USB CDC identifiers

src/machine/board_esp32-wroom-32.go

@@ -0,0 +1,6 @@
+// +build esp32_wroom_32
+
+package machine
+
+// Blue LED on the ESP32-WROOM-32 module.
+const LED = Pin(2)

src/machine/board_feather-m0.go

@@ -83,9 +83,9 @@ var (
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  = PB11 // SCK: SERCOM4/PAD[3]
+	SPI0_SCK_PIN = PB11 // SCK: SERCOM4/PAD[3]
-	SPI0_MOSI_PIN = PB10 // MOSI: SERCOM4/PAD[2]
+	SPI0_SDO_PIN = PB10 // SDO: SERCOM4/PAD[2]
-	SPI0_MISO_PIN = PA12 // MISO: SERCOM4/PAD[0]
+	SPI0_SDI_PIN = PA12 // SDI: SERCOM4/PAD[0]
 )
 
 // SPI on the Feather M0.

src/machine/board_feather-m4.go

@@ -1,9 +1,7 @@
-// +build sam,atsamd51,feather_m4
+// +build feather_m4
 
 package machine
 
-import "device/sam"
-
 // used to reset into bootloader
 const RESET_MAGIC_VALUE = 0xf01669ef
 
@@ -47,13 +45,11 @@ const (
 	USBCDC_DP_PIN = PA25
 )
 
-// UART1 pins
 const (
 	UART_TX_PIN = D1
 	UART_RX_PIN = D0
 )
 
-// UART2 pins
 const (
 	UART2_TX_PIN = A4
 	UART2_RX_PIN = A5
@@ -65,27 +61,11 @@ const (
 	SCL_PIN = D21 // SCL: SERCOM2/PAD[1]
 )
 
-// I2C on the Feather M4.
-var (
-	I2C0 = I2C{
-		Bus:    sam.SERCOM2_I2CM,
-		SERCOM: 2,
-	}
-)
-
 // SPI pins
 const (
-	SPI0_SCK_PIN  = D25 // SCK: SERCOM1/PAD[1]
+	SPI0_SCK_PIN = D25 // SCK: SERCOM1/PAD[1]
-	SPI0_MOSI_PIN = D24 // MOSI: SERCOM1/PAD[3]
+	SPI0_SDO_PIN = D24 // SDO: SERCOM1/PAD[3]
-	SPI0_MISO_PIN = D23 // MISO: SERCOM1/PAD[2]
+	SPI0_SDI_PIN = D23 // SDI: SERCOM1/PAD[2]
-)
-
-// SPI on the Feather M4.
-var (
-	SPI0 = SPI{
-		Bus:    sam.SERCOM1_SPIM,
-		SERCOM: 1,
-	}
 )
 
 // USB CDC identifiers

src/machine/board_feather-m4_baremetal.go

@@ -0,0 +1,43 @@
+// +build sam,atsamd51,feather_m4
+
+package machine
+
+import (
+	"device/sam"
+	"runtime/interrupt"
+)
+
+var (
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM5_USART_INT,
+		SERCOM: 5,
+	}
+
+	UART2 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM0_USART_INT,
+		SERCOM: 0,
+	}
+)
+
+func init() {
+	UART1.Interrupt = interrupt.New(sam.IRQ_SERCOM5_2, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, UART2.handleInterrupt)
+}
+
+// I2C on the Feather M4.
+var (
+	I2C0 = I2C{
+		Bus:    sam.SERCOM2_I2CM,
+		SERCOM: 2,
+	}
+)
+
+// SPI on the Feather M4.
+var (
+	SPI0 = SPI{
+		Bus:    sam.SERCOM1_SPIM,
+		SERCOM: 1,
+	}
+)

src/machine/board_feather-nrf52840.go

@@ -0,0 +1,105 @@
+// +build feather_nrf52840
+
+package machine
+
+const HasLowFrequencyCrystal = true
+
+// GPIO Pins
+const (
+	D0  = P0_25 // UART TX
+	D1  = P0_24 // UART RX
+	D2  = P0_10 // NFC2
+	D3  = P1_15 // LED1
+	D4  = P1_10 // LED2
+	D5  = P1_08
+	D6  = P0_07
+	D7  = P1_02 // Button
+	D8  = P0_16 // NeoPixel
+	D9  = P0_26
+	D10 = P0_27
+	D11 = P0_06
+	D12 = P0_08
+	D13 = P1_09
+	D14 = P0_04 // A0
+	D15 = P0_05 // A1
+	D16 = P0_30 // A2
+	D17 = P0_28 // A3
+	D18 = P0_02 // A4
+	D19 = P0_03 // A5
+	D20 = P0_29 // Battery
+	D21 = P0_31 // AREF
+	D22 = P0_12 // I2C SDA
+	D23 = P0_11 // I2C SCL
+	D24 = P0_15 // SPI MISO
+	D25 = P0_13 // SPI MOSI
+	D26 = P0_14 // SPI SCK
+	D27 = P0_19 // QSPI CLK
+	D28 = P0_20 // QSPI CS
+	D29 = P0_17 // QSPI Data 0
+	D30 = P0_22 // QSPI Data 1
+	D31 = P0_23 // QSPI Data 2
+	D32 = P0_21 // QSPI Data 3
+	D33 = P0_09 // NFC1 (test point on bottom of board)
+)
+
+// Analog Pins
+const (
+	A0 = D14
+	A1 = D15
+	A2 = D16
+	A3 = D17
+	A4 = D18
+	A5 = D19
+	A6 = D20 // Battery
+	A7 = D21 // ARef
+)
+
+const (
+	LED      = D3
+	LED1     = LED
+	LED2     = D4
+	NEOPIXEL = D8
+	BUTTON   = D7
+
+	QSPI_SCK   = D27
+	QSPI_CS    = D28
+	QSPI_DATA0 = D29
+	QSPI_DATA1 = D30
+	QSPI_DATA2 = D31
+	QSPI_DATA3 = D32
+)
+
+// UART0 pins (logical UART1)
+const (
+	UART_RX_PIN = D0
+	UART_TX_PIN = D1
+)
+
+// UART0 is the USB device
+var (
+	UART0 = USB
+)
+
+// I2C pins
+const (
+	SDA_PIN = D22 // I2C0 external
+	SCL_PIN = D23 // I2C0 external
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = D26 // SCK
+	SPI0_SDO_PIN = D25 // SDO
+	SPI0_SDI_PIN = D24 // SDI
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Feather nRF52840 Express"
+	usb_STRING_MANUFACTURER = "Adafruit Industries LLC"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x802A
+)

src/machine/board_feather-stm32f405.go

@@ -0,0 +1,213 @@
+// +build feather_stm32f405
+
+package machine
+
+import (
+	"device/stm32"
+	"runtime/interrupt"
+)
+
+const (
+	NUM_DIGITAL_IO_PINS = 39
+	NUM_ANALOG_IO_PINS  = 7
+)
+
+// Digital pins
+const (
+	// Arduino pin = MCU port pin // primary functions (alternate functions)
+	D0  = PB11 // USART3 RX, PWM TIM2_CH4 (I2C2 SDA)
+	D1  = PB10 // USART3 TX, PWM TIM2_CH3 (I2C2 SCL, I2S2 BCK)
+	D2  = PB3  // GPIO, SPI3 FLASH SCK
+	D3  = PB4  // GPIO, SPI3 FLASH MISO
+	D4  = PB5  // GPIO, SPI3 FLASH MOSI
+	D5  = PC7  // GPIO, PWM TIM3_CH2 (USART6 RX, I2S3 MCK)
+	D6  = PC6  // GPIO, PWM TIM3_CH1 (USART6 TX, I2S2 MCK)
+	D7  = PA15 // GPIO, SPI3 FLASH CS
+	D8  = PC0  // GPIO, Neopixel
+	D9  = PB8  // GPIO, PWM TIM4_CH3 (CAN1 RX, I2C1 SCL)
+	D10 = PB9  // GPIO, PWM TIM4_CH4 (CAN1 TX, I2C1 SDA, I2S2 WSL)
+	D11 = PC3  // GPIO (I2S2 SD, SPI2 MOSI)
+	D12 = PC2  // GPIO (I2S2ext SD, SPI2 MISO)
+	D13 = PC1  // GPIO, Builtin LED
+	D14 = PB7  // I2C1 SDA, PWM TIM4_CH2 (USART1 RX)
+	D15 = PB6  // I2C1 SCL, PWM TIM4_CH1 (USART1 TX, CAN2 TX)
+	D16 = PA4  // A0 (DAC OUT1)
+	D17 = PA5  // A1 (DAC OUT2, SPI1 SCK)
+	D18 = PA6  // A2, PWM TIM3_CH1 (SPI1 MISO)
+	D19 = PA7  // A3, PWM TIM3_CH2 (SPI1 MOSI)
+	D20 = PC4  // A4
+	D21 = PC5  // A5
+	D22 = PA3  // A6
+	D23 = PB13 // SPI2 SCK, PWM TIM1_CH1N (I2S2 BCK, CAN2 TX)
+	D24 = PB14 // SPI2 MISO, PWM TIM1_CH2N (I2S2ext SD)
+	D25 = PB15 // SPI2 MOSI, PWM TIM1_CH3N (I2S2 SD)
+	D26 = PC8  // SDIO
+	D27 = PC9  // SDIO
+	D28 = PC10 // SDIO
+	D29 = PC11 // SDIO
+	D30 = PC12 // SDIO
+	D31 = PD2  // SDIO
+	D32 = PB12 // SD Detect
+	D33 = PC14 // OSC32
+	D34 = PC15 // OSC32
+	D35 = PA11 // USB D+
+	D36 = PA12 // USB D-
+	D37 = PA13 // SWDIO
+	D38 = PA14 // SWCLK
+)
+
+// Analog pins
+const (
+	A0 = D16 // ADC12 IN4
+	A1 = D17 // ADC12 IN5
+	A2 = D18 // ADC12 IN6
+	A3 = D19 // ADC12 IN7
+	A4 = D20 // ADC12 IN14
+	A5 = D21 // ADC12 IN15
+	A6 = D22 // VBAT
+)
+
+func init() {
+	initLED()
+	initUART()
+	initSPI()
+	initI2C()
+}
+
+// -- LEDs ---------------------------------------------------------------------
+
+const (
+	NUM_BOARD_LED      = 1
+	NUM_BOARD_NEOPIXEL = 1
+
+	LED_RED      = D13
+	LED_NEOPIXEL = D8
+	LED_BUILTIN  = LED_RED
+	LED          = LED_BUILTIN
+)
+
+func initLED() {}
+
+// -- UART ---------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#============#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | RX/TX Pins | AltFn | Alias |
+	// #===========#==========#==============#============#=======#=======#
+	// |   UART1   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   |   ~   |
+	// |   UART2   |  USART6  | APB2(84 MHz) |   D5/D6    |   8   |   ~   |
+	// |   UART3   |  USART1  | APB2(84 MHz) |  D14/D15   |   7   |   ~   |
+	// | --------- | -------- | ------------ | ---------- | ----- | ----- |
+	// |   UART0   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   | UART1 |
+	// #===========#==========#==============#============#=======#=======#
+	NUM_UART_INTERFACES = 3
+
+	UART1_RX_PIN = D0 // UART1 = hardware: USART3
+	UART1_TX_PIN = D1 //
+
+	UART2_RX_PIN = D5 // UART2 = hardware: USART6
+	UART2_TX_PIN = D6 //
+
+	UART3_RX_PIN = D14 // UART3 = hardware: USART1
+	UART3_TX_PIN = D15 //
+
+	UART0_RX_PIN = UART1_RX_PIN // UART0 = alias: UART1
+	UART0_TX_PIN = UART1_TX_PIN //
+
+	UART_RX_PIN = UART0_RX_PIN // default/primary UART pins
+	UART_TX_PIN = UART0_TX_PIN //
+)
+
+var (
+	UART1 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART3,
+		AltFuncSelector: stm32.AF7_USART1_2_3,
+	}
+	UART2 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART6,
+		AltFuncSelector: stm32.AF8_USART4_5_6,
+	}
+	UART3 = UART{
+		Buffer:          NewRingBuffer(),
+		Bus:             stm32.USART1,
+		AltFuncSelector: stm32.AF7_USART1_2_3,
+	}
+	UART0 = UART1
+)
+
+func initUART() {
+	UART1.Interrupt = interrupt.New(stm32.IRQ_USART3, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(stm32.IRQ_USART6, UART2.handleInterrupt)
+	UART3.Interrupt = interrupt.New(stm32.IRQ_USART1, UART3.handleInterrupt)
+}
+
+// -- SPI ----------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#==================#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | SCK/SDI/SDO Pins | AltFn | Alias |
+	// #===========#==========#==============#==================#=======#=======#
+	// |   SPI1    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   |   ~   |
+	// |   SPI2    |   SPI3   | APB1(42 MHz) |     D2/D3/D4     |   6   |   ~   |
+	// |   SPI3    |   SPI1   | APB2(84 MHz) |    D17/D18/D19   |   5   |   ~   |
+	// | --------- | -------- | ------------ | ---------------- | ----- | ----- |
+	// |   SPI0    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   | SPI1  |
+	// #===========#==========#==============#==================#=======#=======#
+	NUM_SPI_INTERFACES = 3
+
+	SPI1_SCK_PIN = D23 //
+	SPI1_SDI_PIN = D24 // SPI1 = hardware: SPI2
+	SPI1_SDO_PIN = D25 //
+
+	SPI2_SCK_PIN = D2 //
+	SPI2_SDI_PIN = D3 // SPI2 = hardware: SPI3
+	SPI2_SDO_PIN = D4 //
+
+	SPI3_SCK_PIN = D17 //
+	SPI3_SDI_PIN = D18 // SPI3 = hardware: SPI1
+	SPI3_SDO_PIN = D19 //
+
+	SPI0_SCK_PIN = SPI1_SCK_PIN //
+	SPI0_SDI_PIN = SPI1_SDI_PIN // SPI0 = alias: SPI1
+	SPI0_SDO_PIN = SPI1_SDO_PIN //
+
+	SPI_SCK_PIN = SPI0_SCK_PIN //
+	SPI_SDI_PIN = SPI0_SDI_PIN // default/primary SPI pins
+	SPI_SDO_PIN = SPI0_SDO_PIN //
+)
+
+func initSPI() {}
+
+// -- I2C ----------------------------------------------------------------------
+
+const (
+	// #===========#==========#==============#==============#=======#=======#
+	// | Interface | Hardware |  Bus(Freq)   | SDA/SCL Pins | AltFn | Alias |
+	// #===========#==========#==============#==============#=======#=======#
+	// |   I2C1    |   I2C1   |              |   D14/D15    |       |   ~   |
+	// |   I2C2    |   I2C2   |              |    D0/D1     |       |   ~   |
+	// |   I2C3    |   I2C1   |              |    D9/D10    |       |   ~   |
+	// | --------- | -------- | ------------ | ------------ | ----- | ----- |
+	// |   I2C0    |   I2C1   |              |   D14/D15    |       | I2C1  |
+	// #===========#==========#==============#==============#=======#=======#
+	NUM_I2C_INTERFACES = 3
+
+	I2C1_SDA_PIN = D14 // I2C1 = hardware: I2C1
+	I2C1_SCL_PIN = D15 //
+
+	I2C2_SDA_PIN = D0 // I2C2 = hardware: I2C2
+	I2C2_SCL_PIN = D1 //
+
+	I2C3_SDA_PIN = D9  // I2C3 = hardware: I2C1
+	I2C3_SCL_PIN = D10 //   (interface duplicated on second pair of pins)
+
+	I2C0_SDA_PIN = I2C1_SDA_PIN // I2C0 = alias: I2C1
+	I2C0_SCL_PIN = I2C1_SCL_PIN //
+
+	I2C_SDA_PIN = I2C0_SDA_PIN // default/primary I2C pins
+	I2C_SCL_PIN = I2C0_SCL_PIN //
+)
+
+func initI2C() {}

src/machine/board_hifive1b.go

@@ -37,19 +37,19 @@ const (
 
 const (
 	// TODO: figure out the pin numbers for these.
-	UART_TX_PIN = NoPin
+	UART_TX_PIN = D1
-	UART_RX_PIN = NoPin
+	UART_RX_PIN = D0
 )
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  = NoPin
+	SPI0_SCK_PIN = NoPin
-	SPI0_MOSI_PIN = NoPin
+	SPI0_SDO_PIN = NoPin
-	SPI0_MISO_PIN = NoPin
+	SPI0_SDI_PIN = NoPin
 
-	SPI1_SCK_PIN  = D13
+	SPI1_SCK_PIN = D13
-	SPI1_MOSI_PIN = D11
+	SPI1_SDO_PIN = D11
-	SPI1_MISO_PIN = D12
+	SPI1_SDI_PIN = D12
 )
 
 // I2C pins

src/machine/board_itsybitsy-m0.go

@@ -83,9 +83,9 @@ var (
 
 // SPI pins
 const (
-	SPI0_SCK_PIN  = PB11 // SCK: SERCOM4/PAD[3]
+	SPI0_SCK_PIN = PB11 // SCK: SERCOM4/PAD[3]
-	SPI0_MOSI_PIN = PB10 // MOSI: SERCOM4/PAD[2]
+	SPI0_SDO_PIN = PB10 // SDO: SERCOM4/PAD[2]
-	SPI0_MISO_PIN = PA12 // MISO: SERCOM4/PAD[0]
+	SPI0_SDI_PIN = PA12 // SDI: SERCOM4/PAD[0]
 )
 
 // SPI on the ItsyBitsy M0.
@@ -98,10 +98,10 @@ var (
 
 // "Internal" SPI pins; SPI flash is attached to these on ItsyBitsy M0
 const (
-	SPI1_CS_PIN   = PA27
+	SPI1_CS_PIN  = PA27
-	SPI1_SCK_PIN  = PB23
+	SPI1_SCK_PIN = PB23
-	SPI1_MOSI_PIN = PB22
+	SPI1_SDO_PIN = PB22
-	SPI1_MISO_PIN = PB03
+	SPI1_SDI_PIN = PB03
 )
 
 // "Internal" SPI on Sercom 5

src/machine/board_itsybitsy-m4.go

@@ -1,9 +1,7 @@
-// +build sam,atsamd51,itsybitsy_m4
+// +build itsybitsy_m4
 
 package machine
 
-import "device/sam"
-
 // used to reset into bootloader
 const RESET_MAGIC_VALUE = 0xf01669ef
 
@@ -51,43 +49,22 @@ const (
 	UART_RX_PIN = D0
 )
 
-// UART1 var is on SERCOM3, defined in atsamd51.go
-
-// UART2 pins
 const (
 	UART2_TX_PIN = A4
 	UART2_RX_PIN = D2
 )
 
-// UART2 var is on SERCOM0, defined in atsamd51.go
-
 // I2C pins
 const (
 	SDA_PIN = PA12 // SDA: SERCOM2/PAD[0]
 	SCL_PIN = PA13 // SCL: SERCOM2/PAD[1]
 )
 
-// I2C on the ItsyBitsy M4.
-var (
-	I2C0 = I2C{
-		Bus:    sam.SERCOM2_I2CM,
-		SERCOM: 2,
-	}
-)
-
 // SPI pins
 const (
-	SPI0_SCK_PIN  = PA01 // SCK: SERCOM1/PAD[1]
+	SPI0_SCK_PIN = PA01 // SCK: SERCOM1/PAD[1]
-	SPI0_MOSI_PIN = PA00 // MOSI: SERCOM1/PAD[0]
+	SPI0_SDO_PIN = PA00 // SDO: SERCOM1/PAD[0]
-	SPI0_MISO_PIN = PB23 // MISO: SERCOM1/PAD[3]
+	SPI0_SDI_PIN = PB23 // SDI: SERCOM1/PAD[3]
-)
-
-// SPI on the ItsyBitsy M4.
-var (
-	SPI0 = SPI{
-		Bus:    sam.SERCOM1_SPIM,
-		SERCOM: 1,
-	}
 )
 
 // USB CDC identifiers

src/machine/board_itsybitsy-m4_baremetal.go

@@ -0,0 +1,43 @@
+// +build sam,atsamd51,itsybitsy_m4
+
+package machine
+
+import (
+	"device/sam"
+	"runtime/interrupt"
+)
+
+var (
+	UART1 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM3_USART_INT,
+		SERCOM: 3,
+	}
+
+	UART2 = UART{
+		Buffer: NewRingBuffer(),
+		Bus:    sam.SERCOM0_USART_INT,
+		SERCOM: 0,
+	}
+)
+
+func init() {
+	UART1.Interrupt = interrupt.New(sam.IRQ_SERCOM3_2, UART1.handleInterrupt)
+	UART2.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, UART2.handleInterrupt)
+}
+
+// I2C on the ItsyBitsy M4.
+var (
+	I2C0 = I2C{
+		Bus:    sam.SERCOM2_I2CM,
+		SERCOM: 2,
+	}
+)
+
+// SPI on the ItsyBitsy M4.
+var (
+	SPI0 = SPI{
+		Bus:    sam.SERCOM1_SPIM,
+		SERCOM: 1,
+	}
+)

src/machine/board_itsybitsy-nrf52840.go

@@ -0,0 +1,100 @@
+// +build itsybitsy_nrf52840
+
+package machine
+
+const HasLowFrequencyCrystal = true
+
+// GPIO Pins
+const (
+	D0  = P0_25 // UART TX
+	D1  = P0_24 // UART RX
+	D2  = P1_02
+	D3  = P0_06 // LED1
+	D4  = P0_29 // Button
+	D5  = P0_27
+	D6  = P1_09 // DotStar Clock
+	D7  = P1_08
+	D8  = P0_08 // DotStar Data
+	D9  = P0_07
+	D10 = P0_05
+	D11 = P0_26
+	D12 = P0_11
+	D13 = P0_12
+	D14 = P0_04 // A0
+	D15 = P0_30 // A1
+	D16 = P0_28 // A2
+	D17 = P0_31 // A3
+	D18 = P0_02 // A4
+	D19 = P0_03 // A5
+	D20 = P0_05 // A6
+	D21 = P0_16 // I2C SDA
+	D22 = P0_14 // I2C SCL
+	D23 = P0_20 // SPI SDI
+	D24 = P0_15 // SPI SDO
+	D25 = P0_13 // SPI SCK
+	D26 = P0_19 // QSPI SCK
+	D27 = P0_23 // QSPI CS
+	D28 = P0_21 // QSPI Data 0
+	D29 = P0_22 // QSPI Data 1
+	D30 = P1_00 // QSPI Data 2
+	D31 = P0_17 // QSPI Data 3
+)
+
+// Analog Pins
+const (
+	A0 = D14
+	A1 = D15
+	A2 = D16
+	A3 = D17
+	A4 = D18
+	A5 = D19
+	A6 = D20
+)
+
+const (
+	LED    = D3
+	LED1   = LED
+	BUTTON = D4
+
+	QSPI_SCK   = D26
+	QSPI_CS    = D27
+	QSPI_DATA0 = D28
+	QSPI_DATA1 = D29
+	QSPI_DATA2 = D30
+	QSPI_DATA3 = D31
+)
+
+// UART0 pins (logical UART1)
+const (
+	UART_RX_PIN = D0
+	UART_TX_PIN = D1
+)
+
+// UART0 is the USB device
+var (
+	UART0 = USB
+)
+
+// I2C pins
+const (
+	SDA_PIN = D21 // I2C0 external
+	SCL_PIN = D22 // I2C0 external
+)
+
+// SPI pins
+const (
+	SPI0_SCK_PIN = D25
+	SPI0_SDO_PIN = D24
+	SPI0_SDI_PIN = D23
+)
+
+// USB CDC identifiers
+const (
+	usb_STRING_PRODUCT      = "Adafruit ItsyBitsy nRF52840 Express"
+	usb_STRING_MANUFACTURER = "Adafruit"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x8051
+)