Using a raw identifier as the name of an op2 getter does not work as might be expected

[andyleiserson]

Using a raw identifier as the name of an op2 getter, e.g. (from here):

    #[getter]
    #[string]
    fn r#type(&self) -> &'static str {
        self.r#type.as_str()
    }

It seems like the codegen does not un-escape the identifier, resulting in a property named r#type, and not a property named type, which is what was intended in the above example.

After gfx-rs/wgpu#7736 is merged, this can be reproduced in the wgpu tree by renaming the GPUCompilationMessage.ty getter to r#type and running cargo xtask cts 'webgpu:shader,validation,statement,statement_behavior:invalid_statements:body="for5"'. The test will fail with (note undefined on the line following "VALIDATION FAILED", this is the message type, which should be error):

[fail] webgpu:shader,validation,statement,statement_behavior:invalid_statements:body="for5" (48ms). Log:
  - VALIDATION FAILED: Missing expected compilationInfo 'error' message.
    2:22: undefined:
    Shader '' parsing error: expected assignment or increment/decrement, found ")"
      ┌─ wgsl:2:22
      │
    2 │       for (;; return ) { };
      │                      ^ expected assignment or increment/decrement

[bartlomieju]

You can use #[rename("type")], see https://github.com/denoland/deno/blob/ebbe435f301bc5c923325ed1c3f5472c4cfa29e7/ext/node/ops/sqlite/statement.rs#L786-L789 for examples.

[andyleiserson]

I think I tried that and it didn't help, but I will double-check. Possibly it renames the function in the proc macro output, resulting in a reserved word error?

[andyleiserson]

Yes, that is the issue. This definition:

    #[getter]
    #[rename("type")]
    #[string]
    fn ty(&self) -> &'static str {
        self.r#type.as_str()
    }

Results in:

error: expected identifier, found keyword `type`
  --> deno_webgpu/shader.rs:76:1
   |
76 | #[op2]
   | ^^^^^^ expected identifier, found keyword
   |
   = note: this error originates in the attribute macro `op2` (in Nightly builds, run with -Z macro-backtrace for more info)
help: escape `type` to use it as an identifier
   |
76 | r##[op2]
   | ++

[petamoriken]

It was tackled by #1175, but after trying it in denoland/deno#30352 it still does not seem sufficient.

[littledivy]

Looks like it's caused by ref_ but works if the method is called ref_method:

  #[fast]
  #[rename("ref")]
  fn ref_method(&self) {}

[petamoriken]

The build was successful! denoland/deno#30352

[andyleiserson]

gfx-rs/wgpu#8262 updated the wgpu copy of deno_webgpu to use #[rename(...)].