GitHub - tsavola/wag: WebAssembly compiler implemented in Go

README.md

wag is a WebAssembly compiler implemented as a Go package.

• License: 3-clause BSD
• Author: Timo Savola [email protected]

Features

• Source is a wasm32 binary module. The application embedding the compiler decides what import functions it provides.

• Supports x86-64. Support for 64-bit ARM is planned. (Support for non-64-bit or non-little-endian CPU architectures isn't planned.)

• Single-pass, low-latency ahead-of-time compilation. Early functions can be executed while the latter functions are still being compiled, even while the source is still being downloaded.

• Generated code requires minimal runtime support. It may be run e.g. in a strict seccomp sandbox. Note: calling standard library ABIs is not supported.

• Supports snapshot-and-restore across compiler versions and CPU architectures.

Status

• WebAssembly binary encoding version 1.

• The Go package API hasn't been finalized.

• Cross-compilation will be supported once the backend interface stabilizes.

• Multithreading is not supported. (WebAssembly doesn't define it yet.)

• Much debugging remains to be done...

Testing

Requires Linux, Go, make, clang and libcapstone. About 75% of the WebAssembly spec testsuite is run, by first converting the tests to binary format:

1. go get -t github.com/tsavola/wag
2. make -C $GOPATH/src/github.com/tsavola/wag/testdata/wabt
3. go test -v github.com/tsavola/wag

The wag-toolchain repository tests input from a C/C++ compiler.

Screenshot

=== RUN   TestSnapshot
--- PASS: TestSnapshot (0.00s)
	snapshot_test.go:73: print output:
		10
		--- snapshotting ---
		current memory limit: 0x6a96051ca000
		current stack ptr:    0x6a960533ffc0
		globals+memory addr:  0x6a96051ba000
		stack addr:           0x6a960533f000
		globals+memory size:  65536
		memory size:          65536
		stack offset:         4032
		stacktrace:
		#1  func-3
		#2  func-2
		--- shot snapped ---
		20
	snapshot_test.go:81: resuming
	snapshot_test.go:93: print output:
		20
		30
		330
		40
		440