Implement the compact imports proposal

[bvisness]

The Compact Import Section proposal adds two new binary and text encodings to the import section that can express imports more concisely.

[bvisness]

I see there are a gazillion CI failures that I don't get locally when running cargo test. I tried running cargo test --all and cargo test --locked --all (no idea what --locked does) but I just get:

   Compiling artifacts v0.1.0 (/home/bvisness/Developer/wasm-tools/crates/wit-dylib/test-programs/artifacts)
error: failed to run custom build command for `artifacts v0.1.0 (/home/bvisness/Developer/wasm-tools/crates/wit-dylib/test-programs/artifacts)`

Caused by:
  process didn't exit successfully: `/home/bvisness/Developer/wasm-tools/target/debug/build/artifacts-00f7e71926824b33/build-script-build` (exit status: 101)
  --- stderr

  thread 'main' (224713) panicked at crates/wit-dylib/test-programs/artifacts/build.rs:7:70:
  called `Result::unwrap()` on an `Err` value: NotPresent
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Would appreciate guidance on how to actually run tests here.

[alexcrichton]

For testing cargo test --all should exercise almost all of CI yeah, it's mostly testing other packages in the workspace (cargo test only tests the top-level one). It's safe to ignore --locked as that's just a CI thing.

For the wit-dylib failure, that's a bad error message about the WASI_SDK_PATH env var being set -- I'll work on improving the error message there at least. In the meantime you can pass --exclude wit-dylib to Cargo to ignore that crate for now and it should get all the others building and such

[bvisness]

I am making good progress on the text parser, I think, but also, I have found myself in an absolute lifetime disaster here. I would really appreciate any guidance on how to resolve the errors I'm seeing. I am completely stumped. Surely I don't have to annotate the entire program with 'a just to be able to iterate over imports in the AST?

[bvisness]

As I mentioned on Zulip, I can't seem to use wasm-tools parse on the following file because I get an end-of-file error:

(module
  (import "foo" "bar" (func (param i32)))
  (import "foo" "baz" (func (param i32)))
  (import "foo"
    (item "beep" (func (param i64)))
    (item "boop" (func (param i64)))
  )
)

error: unexpected end-of-file (at offset 0x3f)

It seems to me like it's correctly parsing the text, but then blowing up when trying to do some kind of...validation run of the binary parser, except with no features enabled? Or maybe something else is wrong, since the compact encoding should trigger an "unexpected externtype" error.

[bvisness]

Ok, I think it's all pretty much working, except that there are WIT linking issues that I don't know how to resolve. Would appreciate any guidance on that. I'll leave this in a draft state for a bit while I add spec tests to the proposal repo and use them to validate both this PR and our SpiderMonkey implementation.

[alexcrichton]

Ah those are safe failures to ignore. That's from rustc nightly updates breaking things which I've resolved in #2402 by pinning nightly temporarily

[alexcrichton]

Code-wise everything looks good to me modulo TODO-docs 👍

[bvisness]

No idea what those test failures are...I don't think I changed that file.

If you'd like, I can wait to add spec tests for compact imports before merging this? But I'm not sure what you do for proposal spec tests in this repo.

[alexcrichton]

The failures here are related to Rust 1.92 being released, which should be fixed now with a rebase to pick up the changes from #2402.

Otherwise it's ok to defer the rigorous tests to the proposal testsuite, but it would be good to have at least a basic test in this repository for some of the textual forms and basic validation -- for example the binary format should be rejected if the feature is not enabled, and then accepted with the feature enabled.

[bvisness]

Well, I rebased, I added some tests, they work locally, and now I'm getting newly inscrutable build errors.

[alexcrichton]

> #3 ERROR: failed to authorize: failed to fetch oauth token: unexpected status from POST request to https://auth.docker.io/token: 500 Internal Server Error: an unknown error occurred during the request

just network errors, I'll retry