Skip unknown entries in the custom name section

[athei]

twiggy uses an ancient version of wasmparser which errors out when encountering an "unknown" entry in the custom name section. The error looks like this:

error: WASM error: Invalid name type (at offset 276799)
  caused by: Invalid name type (at offset 276799)

This PR adds code to just skip any name entry which fails to parse. This is a short term solution to resolve one specific issue which is a blocker for me. I also started to port twiggy to the newest wasmparser version in order to increase compatibility with new wasm features. This is a lot of work, though. The API changed quite a bit.

fixes #574

[HCastano]

Looks like work to update wasmparser has already been started in #543, but it hasn't moved in a while 😞

[AlexEne]

This would be quite useful for wasm32-wasi cases.
Is there any work left that or help needed with in order needed to get this in a ready-to-merge state?

[athei]

From my point of view this could be just merged. But It seems that this project is abandoned.

[AlexEne]

I'll ask around in the rust-wasm discord. I'd gladly share some maintenance work on this as it's a really helpful tool

[AlexEne]

I've tested this locally and existing tests still pass.
It seems that this doesn't add a new test for the case, but I'll merge as-is for now as I really need this functionality too :D

Before I'll merge anything else, I'll first try to figure out what's up with the CI (maybe github actions may be easier to work with),

[Artoria2e5]

Will it be possible to prepare a new git tag? It's a bit annoying to manually tell cargo to use git...

[AlexEne]

Yes, I can do a release once I finish the current cleanup work. I think updating some of the wasmparser lib will take a while so maybe i'll do one before that.

[Manishearth]

@AlexEne Do you have an idea of how long that would take? We're stuck on an old Rust nightly because of this bug, would be great to update. As a bandaid I can install twiggy from git, so it's not a huge deal, but would be nice to have a rough timeline.

[AlexEne]

I think it's safe to publish, I'll either do it by the end of today, or early next week.

[Manishearth]

Awesome, thanks!

[AlexEne]

I tried publishing a new version, I'm getting a weird error. I will debug this on Tuesday:
Full logs https://gist.github.com/AlexEne/36311d128ec5ee67ec0c916c01c536e5
Only cargo publish fails. More exactly cargo package. cargo build or cargo build --release works just fine, and as the error shows, the import is there.

error[E0599]: no variant or associated item named `from_args` found for enum `Options` in the current scope
  --> twiggy.rs:17:33
   |
17 |     let options = opt::Options::from_args();
   |                                 ^^^^^^^^^ variant or associated item not found in `Options`
   |
   = help: items from traits can only be used if the trait is in scope
help: the following trait is implemented but not in scope; perhaps add a `use` for it:
   |
6  | use structopt::StructOpt;
   |

warning: unused import: `structopt::StructOpt`
 --> twiggy.rs:9:5
  |
9 | use structopt::StructOpt;
  |
  = note: `#[warn(unused_imports)]` on by default

error: aborting due to previous error; 1 warning emitted

[philipc]

The meaning of that error is that two different versions of structopt are in use.
You probably need to update these dependency versions:

twiggy/twiggy/Cargo.toml

Lines 22 to 26 in f2e5abb

	twiggy-analyze = { version = "=0.6.0", path = "../analyze" }
	twiggy-ir = { version = "=0.6.0", path = "../ir" }
	twiggy-opt = { version = "=0.6.0", path = "../opt", features = ["cli"] }
	twiggy-parser = { version = "=0.6.0", path = "../parser" }
	twiggy-traits = { version = "=0.6.0", path = "../traits" }

[AlexEne]

That's strange, both are at 0.3.22 when doing cargo tree but maybe cargo.lock has different things cached.
I'll check when i get home

[philipc]

You're still depending on twiggy-opt version 0.6.0 (instead of 0.7.0), which depends on structopt 0.2. When building in the workspace, the path attribute takes precedence.

[AlexEne]

@fitzgen Can I please get crates.io permissions for the other crates so i can publish a new twiggy release? (twiggy-ir, etc.)

[fitzgen]

Done

[AlexEne]

Thank you!