1878779 - [rustc-1.77] error: field `0` is never read

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Mike Hommey [:glandium]]

[task 2024-02-05T21:56:30.403Z] 21:56:30    ERROR -  error: field `0` is never read
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -     --> gfx/wr/webrender/src/device/gl.rs:937:28
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -  937 | pub struct UniformLocation(gl::GLint);
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      |            --------------- ^^^^^^^^^
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      |            |
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      |            field in this struct
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.403Z] 21:56:30     INFO -      = note: `UniformLocation` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -      = note: `-D dead-code` implied by `-D warnings`
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -      = help: to override `-D warnings` add `#[allow(dead_code)]`
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -  help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -  937 | pub struct UniformLocation(());
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -      |                            ~~
[task 2024-02-05T21:56:30.404Z] 21:56:30    ERROR -  error: field `0` is never read
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -     --> gfx/wr/webrender/src/device/query_gl.rs:316:25
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.404Z] 21:56:30     INFO -  316 | pub struct GpuTimeQuery(GpuMarker);
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |            ------------ ^^^^^^^^^
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |            |
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |            field in this struct
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -  help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -  316 | pub struct GpuTimeQuery(());
[task 2024-02-05T21:56:30.405Z] 21:56:30     INFO -      |                         ~~
[task 2024-02-05T21:56:30.405Z] 21:56:30    ERROR -  error: could not compile `webrender` (lib) due to 2 previous errors

Comment 1

[Mike Hommey [:glandium]]

pub struct UniformLocation(gl::GLint);

This one is never read from Rust, but it's used on the C++ side. It should be marked with #[allow(dead_code)]

pub struct GpuTimeQuery(GpuMarker);

This one is never used at all, which is ironic since it's marked as #[must_use]. The type could be removed entirely, and start_timer could be made to return nothing.

Comment 2

[Mike Hommey [:glandium]]

(In reply to Mike Hommey [:glandium] from comment #1)

pub struct UniformLocation(gl::GLint);

This one is never read from Rust, but it's used on the C++ side. It should be marked with #[allow(dead_code)]

pub struct GpuTimeQuery(GpuMarker);

This one is never used at all, which is ironic since it's marked as #[must_use]. The type could be removed entirely, and start_timer could be made to return nothing.

Oh, the impl Drop on GpuMarker actually makes it relevant. That seems to be a diagnostic problem in rustc...

Comment 3

[Mike Hommey [:glandium]]

Pinged the relevant upstream issue. https://github.com/rust-lang/rust/issues/119645#issuecomment-1928443484

Comment 4

[Mike Hommey [:glandium]]

Attachment: Bug 1878779 - Mark fields rust 1.77 thinks are dead code as being allowed.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/35ef255a54bd
Mark fields rust 1.77 thinks are dead code as being allowed. r=gfx-reviewers,aosmond

Comment 6

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/35ef255a54bd