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jieyouxu opened this issue May 23, 2025 · 0 comments · Fixed by #141456
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Unexpected cfg condition name diagnostic is sometimes confusing #141440

jieyouxu opened this issue May 23, 2025 · 0 comments · Fixed by #141456
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A-cfg Area: `cfg` conditional compilation A-diagnostics Area: Messages for errors, warnings, and lints D-confusing Diagnostics: Confusing error or lint that should be reworked. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

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@jieyouxu
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Discussion (not in scope for this PR): Maybe this diagnostic is a bit misleading? version is a condition name, but just that the parenthesized name-value form (forgot what that form is called technically) is what's considered valid cfg, and not the version = ".." name-with-literal-value form.

Originally posted by @jieyouxu in #141413 (comment)

If a cfg by the name-with-parenthesized-value form exists (e.g. cfg(version(..))) and the user writes the meta literal(?) form e.g. cfg(version = ".."), we currently produce a diagnostic that says

warning: unexpected `cfg` condition name: `version`

This is technically true, because we don't expect the version = ".." form, we expect the version(..) form.

I wonder if we could clarify the diagnostic here if the version(..) form is a thing but not the version = ".." form.

(Picked version as an example, this is generally applicable.)
@rustbot rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label May 23, 2025
@jieyouxu jieyouxu added A-diagnostics Area: Messages for errors, warnings, and lints T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. A-cfg Area: `cfg` conditional compilation D-confusing Diagnostics: Confusing error or lint that should be reworked. and removed needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. labels May 23, 2025
@jieyouxu jieyouxu mentioned this issue May 23, 2025
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@Urgau Urgau mentioned this issue May 23, 2025
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matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue May 24, 2025
@matthiaskrgr
Rollup merge of rust-lang#141456 - Urgau:check-cfg-version-pred, r=ji…
8bd0ebd 
…eyouxu

Suggest correct `version("..")` predicate syntax in check-cfg

This PR specialize the `unexpected_cfgs` lint diagnostic to suggest correct `version("..")` predicate syntax when providing the key-value one, eg. `version = "1.27"`.

Fixes rust-lang#141440
r? `@jieyouxu`
@bors bors closed this as completed in 8019d08 May 24, 2025
rust-timer added a commit that referenced this issue May 24, 2025
@rust-timer
Unrolled build for #141456
69c6b88 
Rollup merge of #141456 - Urgau:check-cfg-version-pred, r=jieyouxu

Suggest correct `version("..")` predicate syntax in check-cfg

This PR specialize the `unexpected_cfgs` lint diagnostic to suggest correct `version("..")` predicate syntax when providing the key-value one, eg. `version = "1.27"`.

Fixes #141440
r? ``@jieyouxu``
github-actions bot pushed a commit to rust-lang/miri that referenced this issue May 25, 2025
@matthiaskrgr
Rollup merge of #141456 - Urgau:check-cfg-version-pred, r=jieyouxu
e6db84f 
Suggest correct `version("..")` predicate syntax in check-cfg

This PR specialize the `unexpected_cfgs` lint diagnostic to suggest correct `version("..")` predicate syntax when providing the key-value one, eg. `version = "1.27"`.

Fixes rust-lang/rust#141440
r? ``@jieyouxu``
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A-cfg Area: `cfg` conditional compilation A-diagnostics Area: Messages for errors, warnings, and lints D-confusing Diagnostics: Confusing error or lint that should be reworked. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
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Suggest correct version("..") predicate syntax in check-cfg Urgau/rust
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