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Merged
merged 1 commit into from
Jan 16, 2025
Merged

[cfg_match] Adjust syntax #133720

merged 1 commit into from
Jan 16, 2025
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c410-f3r
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@c410-f3r c410-f3r commented Dec 1, 2024 •
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A year has passed since the creation of #115585 and the feature, as expected, is not moving forward. Let's change that.

This PR proposes changing the arm's syntax from cfg(SOME_CONDITION) => { ... } to SOME_CODITION => {}.

match_cfg! {
   unix => {
        fn foo() { /* unix specific functionality */ }
    }
    target_pointer_width = "32" => {
        fn foo() { /* non-unix, 32-bit functionality */ }
    }
    _ => {
        fn foo() { /* fallback implementation */ }
    }
}

Why? Because after several manual migrations in #116342 it became clear, at least for me, that cfg prefixes are unnecessary, verbose and redundant.

Again, everything is just a proposal to move things forward. If the shown syntax isn't ideal, feel free to close this PR or suggest other alternatives.

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r? @davidtwco

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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Dec 1, 2024
@c410-f3r c410-f3r changed the title [macro_metavar_expr_concat] Adjust syntax [cfg_match] Adjust syntax Dec 1, 2024
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c410-f3r commented Dec 1, 2024

@rustbot modify labels: +T-libs-api -T-compiler

@rustbot rustbot added T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. and removed T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Dec 1, 2024
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@c410-f3r c410-f3r force-pushed the cfg-match-foo-bar-baz branch from d3bc54d to 7087e0d Compare December 1, 2024 23:58
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@c410-f3r c410-f3r force-pushed the cfg-match-foo-bar-baz branch from 7087e0d to bf503ec Compare December 2, 2024 00:11
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@c410-f3r c410-f3r force-pushed the cfg-match-foo-bar-baz branch from 6a107c8 to 5c363b1 Compare December 2, 2024 01:31
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r? libs-api

@rustbot rustbot assigned m-ou-se and unassigned davidtwco Dec 2, 2024
danielhenrymantilla
danielhenrymantilla reviewed Dec 3, 2024
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@c410-f3r c410-f3r force-pushed the cfg-match-foo-bar-baz branch from 5c363b1 to c635f0d Compare December 4, 2024 13:18
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r? libs-api

@rustbot rustbot assigned joshtriplett and unassigned m-ou-se Dec 11, 2024
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This looks great. Let's ship it.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jan 16, 2025
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@bors bors merged commit fca1481 into rust-lang:master Jan 16, 2025
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@rustbot rustbot added this to the 1.86.0 milestone Jan 16, 2025
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Noratrieb
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compiler/rustc_span/src/analyze_source_file.rs
}

#[cfg(not(bootstrap))]
cfg_match! {
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Please don't duplicate such large amounts of complicated code next time, it causes headaches when someone is trying to change it (which happened here). Instead it would have been nicer if you had reverted this back to use cfg_if or just plain cfg until the bootstrap compiler had the new cfg_match syntax.

@jieyouxu jieyouxu added the F-cfg_select `#![feature(cfg_select)]` label Aug 14, 2025
@jieyouxu jieyouxu mentioned this pull request Aug 14, 2025
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