Fix types being marked as dead when they are inferred generic arguments #148262
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JonathanBrouwer force-pushed the dead-code-inference branch from 6d0e333 to 5af2270 Compare 
nnethercote approved these changes Oct 30, 2025
| r=me with the nit addressed, thanks! @bors delegate=JonathanBrouwer |
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Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>
JonathanBrouwer force-pushed the dead-code-inference branch from 5af2270 to a09c4fc Compare 
| @bors r=nnethercote rollup |
bors added S-waiting-on-bors GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request Oct 30, 2025
…e, r=nnethercote Fix types being marked as dead when they are inferred generic arguments Previously usages of a type in a pattern were ignored. This is incorrect, since if the type is in a pattern we're clearly producing it in the expression we're matching against. I think this `in_pat` check was meant to be only for variants, which we should indeed ignore since we can just remove the match arm that matches the pattern. Please double check my logic here since this is my first time touching the dead-code pass and I'm not 100% sure this is what the `self.in_pat` check was for. Fixes rust-lang#148144
bors added a commit that referenced this pull request Oct 30, 2025
Rollup of 4 pull requests Successful merges: - #139751 (Implement pin-project in pattern matching for `&pin mut|const T`) - #147633 (Add new `--bypass-ignore-backends` option) - #148262 (Fix types being marked as dead when they are inferred generic arguments) - #148268 (rustdoc: fix `--emit=dep-info` on scraped examples) r? `@ghost` `@rustbot` modify labels: rollup
GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request Oct 30, 2025
…e, r=nnethercote Fix types being marked as dead when they are inferred generic arguments Previously usages of a type in a pattern were ignored. This is incorrect, since if the type is in a pattern we're clearly producing it in the expression we're matching against. I think this `in_pat` check was meant to be only for variants, which we should indeed ignore since we can just remove the match arm that matches the pattern. Please double check my logic here since this is my first time touching the dead-code pass and I'm not 100% sure this is what the `self.in_pat` check was for. Fixes rust-lang#148144
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Previously usages of a type in a pattern were ignored. This is incorrect, since if the type is in a pattern we're clearly producing it in the expression we're matching against.
I think this
in_patcheck was meant to be only for variants, which we should indeed ignore since we can just remove the match arm that matches the pattern. Please double check my logic here since this is my first time touching the dead-code pass and I'm not 100% sure this is what theself.in_patcheck was for.Fixes #148144