This release adds support for the recently released Go 1.18, although not for all language features yet. We have also added support for LLVM 14 which is the latest release of the compiler framework. Lots of improvements to the runtime and standard library support, especially when running in WASM/WASI environments. Also a whole bunch of bugfixes and improvements to our hardware support, in particular for the RP2040 processor.

The following new boards have been added this release:

• esp32-c3-12f
• macropad-rp2040
• teensy41
• thingplus-rp2040
• xiao-ble

Here is the complete list of changes:

• command line
  • add -work flag
  • add Go 1.18 support
  • add LLVM 14 support
  • run: add support for command-line parameters
  • build: calculate default output path if -o is not specified
  • build: add JSON output
  • test: support multiple test binaries with -c
  • test: support flags like -v on all targets (including emulated firmware)
• compiler
  • add support for ThinLTO
  • use compiler-rt from LLVM
  • builder: prefer GNU build ID over Go build ID for caching
  • builder: add support for cross compiling to Darwin
  • builder: support machine outlining pass in stacksize calculation
  • builder: disable asynchronous unwind tables
  • compileopts: fix emulator configuration on non-amd64 Linux architectures
  • compiler: move allocations > 256 bytes to the heap
  • compiler: fix incorrect unsafe.Alignof on some 32-bit architectures
  • compiler: accept alias for slice cap builtin
  • compiler: allow slices of empty structs
  • compiler: fix difference in aliases in interface methods
  • compiler: make RawSyscall an alias for Syscall
  • compiler: remove support for memory references in AsmFull
  • loader: only add Clang header path for CGo
  • transform: fix poison value in heap-to-stack transform
• standard library
  • internal/fuzz: add this package as a shim
  • os: implement readdir for darwin and linux
  • os: add DirFS, which is used by many programs to access readdir.
  • os: isWine: be compatible with older versions of wine, too
  • os: implement RemoveAll
  • os: Use a uintptr for NewFile
  • os: add stubs for exec.ExitError and ProcessState.ExitCode
  • os: export correct values for DevNull for each OS
  • os: improve support for Signal by fixing various bugs
  • os: implement File.Fd method
  • os: implement UserHomeDir
  • os: add exec.ProcessState stub
  • os: implement Pipe for darwin
  • os: define stub ErrDeadlineExceeded
  • reflect: add stubs for more missing methods
  • reflect: rename reflect.Ptr to reflect.Pointer
  • reflect: add Value.FieldByIndexErr stub
  • runtime: fix various small GC bugs
  • runtime: use memzero for leaking collector instead of manually zeroing objects
  • runtime: implement memhash
  • runtime: implement fastrand
  • runtime: add stub for debug.ReadBuildInfo
  • runtime: add stub for NumCPU
  • runtime: don't inline runtime.alloc with -gc=leaking
  • runtime: add Version
  • runtime: add stubs for NumCgoCall and NumGoroutine
  • runtime: stub {Lock,Unlock}OSThread on Windows
  • runtime: be able to deal with a very small heap
  • syscall: make Environ return a copy of the environment
  • syscall: implement getpagesize and munmap
  • syscall: wasi: define MAP_SHARED and PROT_READ
  • syscall: stub mmap(), munmap(), MAP_SHARED, PROT_READ, SIGBUS, etc. on nonhosted targets
  • syscall: darwin: more complete list of signals
  • syscall: wasi: more complete list of signals
  • syscall: stub WaitStatus
  • syscall/js: allow copyBytesTo(Go|JS) to use Uint8ClampedArray
  • testing: implement TempDir
  • testing: nudge type TB closer to upstream; should be a no-op change.
  • testing: on baremetal platforms, use simpler test matcher
• targets
  • atsamd: fix usbcdc initialization when -serial=uart
  • atsamd51: allow higher frequency when using SPI
  • esp: support CGo
  • esp32c3: add support for input pin
  • esp32c3: add support for GPIO interrupts
  • esp32c3: add support to receive UART data
  • rp2040: fix PWM bug at high frequency
  • rp2040: fix some minor I2C bugs
  • rp2040: fix incorrect inline assembly
  • rp2040: fix spurious i2c STOP during write+read transaction
  • rp2040: improve ADC support
  • wasi: remove --export-dynamic linker flag
  • wasm: remove heap allocator from wasi-libc
• boards
  • circuitplay-bluefruit: move pin mappings so board can be compiled for WASM use in Playground
  • esp32-c3-12f: add the ESP32-C3-12f Kit
  • m5stamp-c3: add pin setting of UART
  • macropad-rp2040: add the Adafruit MacroPad RP2040 board
  • nano-33-ble: typo in LPS22HB peripheral definition and documentation (#2579)
  • teensy41: add the Teensy 4.1 board
  • teensy40: add ADC support
  • teensy40: add SPI support
  • thingplus-rp2040: add the SparkFun Thing Plus RP2040 board
  • wioterminal: add DefaultUART
  • wioterminal: verify written data when flashing through OpenOCD
  • xiao-ble: add XIAO BLE nRF52840 support