Add wasm32-wasi-musl target

[rockwotj]

I would like to be able to compile wasm/wasi with zig + bazel. This adds
a toolchain to be able to do so. Wasm/wasi is a pretty rapidly changing
space, but I've choosen the most specific naming that I could (WASI
preview 1).

I've confirmed this works by running the compiled binary with wasmtime,
a popular wasm/wasi runtime.

bazel run --run_under=wasmtime //test/c:which_libc_wasip1_wasm

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[motiejus]

Since you are changing the final archive, you will need to add this here:

hermetic_cc_toolchain/tools/releaser/main.go

Line 47 in 361dbd1

"v2.2.1": "3b8107de0d017fe32e6434086a9568f97c60a111b49dc34fc7001e139c30fdea",

"v3.0.0": "a6dd921a52e40efb88d816d7d0bc79fd2501a2a1de219f69fbfd546fe4044fd1"

[rockwotj]

"v3.0.0": "a6dd921a52e40efb88d816d7d0bc79fd2501a2a1de219f69fbfd546fe4044fd1"

Ah thanks! I see what's happening now. That was non obvious 😄

[motiejus]

This is good, but we need a way to run and verify that the binary runs at least on one platform.

I see the following options:

1. Use a system package and run with --run_under. MacOS and Windows seems to be available, or curl <...> | bash on Ubuntu.
2. Get a "lightweight" runtime and use it. The most lightweight I found and was able to quickly run was from zig itself:

code/zig/stage1$ zig cc -O3 -target x86_64-linux-musl wasm2c.c -o wasm2c
code/zig/stage1$ ./wasm2c ~/code/hermetic_cc_toolchain/bazel-bin/test/c/which_libc-__platform_wasip1_wasm hello.c
code/zig/stage1$ zig cc -O3 -target x86_64-linux-musl hello.c wasi.c -o hello
code/zig/stage1$ ./hello foo
wasi non-glibc

This one should work on all platforms. You are welcome to explore any options.

[rockwotj]

This is good, but we need a way to run and verify that the binary runs at least on one platform.

I have used a go based wasm runtime to verify this within Bazel. PTAL

[rockwotj]

I see snyk is unhappy. Please advise 😄

[motiejus]

wazero is a great find!

This is coming together pretty nicely. I am replacing test/c/test.sh with a Go version, which will:

1. replace the dependency on system shell.
2. be a good place to add wazero as an optional executor. That way, wasm tests can be executed on any platform.

My WIP branch is in https://github.com/motiejus/hermetic_cc_toolchain/tree/test_go , feel free to keep an eye for a PR here too.

[motiejus]

I landed #166, which opens up a path for you to add a WASI runner to https://github.com/uber/hermetic_cc_toolchain/blob/a5dcb8c486ecbbbbf82f70f189a35fe85a0a9810/test/c/c_test.go .

Can you rebase and move your executor there? That way we will be able to test WASI on all platforms (via c_runner.go) and avoid adding tests/wasi.

[rockwotj]

@motiejus updated - thanks!

[motiejus]

This is good. Consider updating https://github.com/uber/hermetic_cc_toolchain/?tab=readme-ov-file#use-case-always-compile-with-zig-cc and https://github.com/uber/hermetic_cc_toolchain/?tab=readme-ov-file#note-naming.

[rockwotj]

Consider updating

Good callout. Done thanks!

[motiejus]

Thanks!