rustc: Flag metadata compatible with multiple CGUs #60270
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It looks like the `OutputType::Metadata` kind in the compiler was misclassified in rust-lang#38571 long ago by accident as incompatible with codegen units and a single output file. This means that if you emit both a linkable artifact and metadata it silently turns off multiple codegen units unintentionally! This commit corrects the situation to ensure that if `--emit metadata` is used it doesn't implicitly disable multiple codegen units. This will ensure we don't accidentally regress compiler performance when striving to implement pipelined compilation!
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r? @oli-obk (rust_highfive has picked a reviewer for you, use r? to override) |
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Note that I haven't written a test here because I can't think of a great way to test this, but if others have suggestions I'm all for adding a test! This was added as a precursor to rust-lang/cargo#6864 where it was discovered that there were funny compiler performance characteristics in the initial testing. |
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@bors r+ rollup |
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📌 Commit 955f283 has been approved by |
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…oli-obk rustc: Flag metadata compatible with multiple CGUs It looks like the `OutputType::Metadata` kind in the compiler was misclassified in rust-lang#38571 long ago by accident as incompatible with codegen units and a single output file. This means that if you emit both a linkable artifact and metadata it silently turns off multiple codegen units unintentionally! This commit corrects the situation to ensure that if `--emit metadata` is used it doesn't implicitly disable multiple codegen units. This will ensure we don't accidentally regress compiler performance when striving to implement pipelined compilation!
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Rollup of 4 pull requests Successful merges: - #60022 (Document `Item` type in `std::env::SplitPaths` iterator.) - #60270 (rustc: Flag metadata compatible with multiple CGUs) - #60325 (Document ast::ExprKind::Type) - #60347 (Remove `-Z two-phase-borrows` and `-Z two-phase-beyond-autoref`) Failed merges: r? @ghost
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It looks like the
OutputType::Metadatakind in the compiler wasmisclassified in #38571 long ago by accident as incompatible with
codegen units and a single output file. This means that if you emit both
a linkable artifact and metadata it silently turns off multiple codegen
units unintentionally!
This commit corrects the situation to ensure that if
--emit metadatais used it doesn't implicitly disable multiple codegen units. This will
ensure we don't accidentally regress compiler performance when striving
to implement pipelined compilation!