rust-lang / rust-lang/rustfmt

format_macro_matchers deletes comments

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#3,960 1 comment 0 reactions 0 assignees View on GitHub

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A-macros C-bug only-with-option P-low
Dominant language
Rust
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Description

When I just have a .rustfmt.toml with:

unstable_features = true
format_macro_matchers = true

Rustfmt 1.4.9 will the delete the comment in this:

macro_rules! m {
    (
        $arg0:ident, // comment
    ) => {};
}

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Research direction

Reproduce the report with a .rustfmt.toml enabling unstable_features and format_macro_matchers, then format the shown macro_rules! example. Trace the formatter path handling macro matchers and verify that the inline comment remains present after formatting.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
tooling
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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