0.34.0

This release adds support for //go:wasmexport that is a standardized way to export WebAssembly functions to the host, improves garbage collection performance (especially on wasm), adds big-endian MIPS support (GOOS=mips), and adds two new boards! It also contains a number of smaller improvements and bug fixes.

• general
  • fix GOOS=wasip1 for tinygo test
  • add -C DIR flag
  • add initial documentation for project governance
  • add -ldflags='-extldflags=...' support
  • improve usage message with tinygo help and when passing invalid parameters
• compiler
  • builder: remove environment variables when invoking Clang, to avoid the environment changing the behavior
  • builder: check for the Go toolchain version used to compile TinyGo
  • cgo: add C.CBytes implementation
  • compiler: fix passing weirdly-padded structs as parameters to new goroutines
  • compiler: support pragmas on generic functions
  • compiler: do not let the slice buffer escape when casting a []byte or []rune to a string, to help escape analysis
  • compiler: conform to the latest iteration of the wasm types proposal
  • loader: don't panic when main package is not named 'main'
  • loader: make sure we always return type checker errors even without type errors
  • transform: optimize range over []byte(string)
• standard library
  • crypto/x509: add package stub to build crypto/x509 on macOS
  • machine/usb/adc/midi: fix PitchBend
  • os: add Truncate stub for baremetal
  • os: add stubs for os.File deadlines
  • os: add internal net.newUnixFile for the net package
  • runtime: stub runtime_{Before,After}Exec for linkage
  • runtime: randomize map accesses
  • runtime: support maps.Clone
  • runtime: add more fields to MemStats
  • runtime: implement newcoro, coroswitch to support package iter
  • runtime: disallow defer in interrupts
  • runtime: add support for os/signal on Linux and MacOS
  • runtime: add gc layout info for some basic types to help the precise GC
  • runtime: bump GC mark stack size to avoid excessive heap rescans
• targets
  • darwin: use Go standard library syscall package instead of a custom one
  • fe310: support GPIO PinInput
  • mips: fix compiler crash with GOMIPS=softfloat and defer
  • mips: add big-endian (GOARCH=mips) support
  • mips: use MIPS32 (instead of MIPS32R2) as the instruction set for wider compatibility
  • wasi: add relative and absolute --dir options to wasmtime args
  • wasip2: add wasmtime -S args to support network interfaces
  • wasm: add //go:wasmexport support (for all WebAssembly targets)
  • wasm: use precise instead of conservative GC for WebAssembly (including WASI)
  • wasm-unknown: add bulk memory flags since basically every runtime has it now
• boards
  • add RAKwireless RAK4631
  • add WaveShare ESP-C3-32S-Kit