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merged 1 commit into from
Aug 15, 2025

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Zalathar
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The data structures in coverage::mappings were historically very useful for isolating the details of mapping-extraction from the details of how coverage mappings are stored in MIR.

But because of various changes that have taken place over time, they now provide little value, and cause difficulty for the coordinated changes that will be needed for introducing expansion mapping support.

In the future, the pendulum might eventually swing back towards these being useful again, but we can always reintroduce suitable intermediate data structures if and when that happens. For now, the simplicity of not having this intermediate layer is a higher priority.

There should be no changes to compiler output.

@Zalathar Zalathar added the A-code-coverage Area: Source-based code coverage (-Cinstrument-coverage) label Aug 14, 2025
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rustbot commented Aug 14, 2025

r? @petrochenkov

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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. labels Aug 14, 2025
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rustbot commented Aug 14, 2025

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

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@bors r+

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bors commented Aug 14, 2025

📌 Commit ecce90b has been approved by petrochenkov

It is now in the queue for this repository.

@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 Aug 14, 2025
Zalathar added a commit to Zalathar/rust that referenced this pull request Aug 15, 2025
…henkov

coverage: Remove intermediate data structures from mapping creation

The data structures in `coverage::mappings` were historically very useful for isolating the details of mapping-extraction from the details of how coverage mappings are stored in MIR.

But because of various changes that have taken place over time, they now provide little value, and cause difficulty for the coordinated changes that will be needed for introducing expansion mapping support.

In the future, the pendulum might eventually swing back towards these being useful again, but we can always reintroduce suitable intermediate data structures if and when that happens. For now, the simplicity of not having this intermediate layer is a higher priority.

There should be no changes to compiler output.
bors added a commit that referenced this pull request Aug 15, 2025
Rollup of 22 pull requests

Successful merges:

 - #118087 (Add Ref/RefMut try_map method)
 - #122661 (Change the desugaring of `assert!` for better error output)
 - #140740 (Add `-Zindirect-branch-cs-prefix`)
 - #142640 (Implement autodiff using intrinsics)
 - #143075 (compiler: Allow `extern "interrupt" fn() -> !`)
 - #144865 (Fix tail calls to `#[track_caller]` functions)
 - #144944 (E0793: Clarify that it applies to unions as well)
 - #144947 (Fix description of unsigned `checked_exact_div`)
 - #145004 (Couple of minor cleanups)
 - #145005 (strip prefix of temporary file names when it exceeds filesystem name length limit)
 - #145012 (Tail call diagnostics to include lifetime info)
 - #145065 (resolve: Introduce `RibKind::Block`)
 - #145120 (llvm: Accept new LLVM lifetime format)
 - #145189 (Weekly `cargo update`)
 - #145235 (Minor `[const]` tweaks)
 - #145275 (fix(compiler/rustc_codegen_llvm): apply `target-cpu` attribute)
 - #145322 (Resolve the prelude import in `build_reduced_graph`)
 - #145331 (Make std use the edition 2024 prelude)
 - #145369 (Do not ICE on private type in field of unresolved struct)
 - #145378 (Add `FnContext` in parser for diagnostic)
 - #145389 ([rustdoc] Revert "rustdoc search: prefer stable items in search results")
 - #145392 (coverage: Remove intermediate data structures from mapping creation)

r? `@ghost`
`@rustbot` modify labels: rollup
bors added a commit that referenced this pull request Aug 15, 2025
Rollup of 21 pull requests

Successful merges:

 - #118087 (Add Ref/RefMut try_map method)
 - #122661 (Change the desugaring of `assert!` for better error output)
 - #142640 (Implement autodiff using intrinsics)
 - #143075 (compiler: Allow `extern "interrupt" fn() -> !`)
 - #144865 (Fix tail calls to `#[track_caller]` functions)
 - #144944 (E0793: Clarify that it applies to unions as well)
 - #144947 (Fix description of unsigned `checked_exact_div`)
 - #145004 (Couple of minor cleanups)
 - #145005 (strip prefix of temporary file names when it exceeds filesystem name length limit)
 - #145012 (Tail call diagnostics to include lifetime info)
 - #145065 (resolve: Introduce `RibKind::Block`)
 - #145120 (llvm: Accept new LLVM lifetime format)
 - #145189 (Weekly `cargo update`)
 - #145235 (Minor `[const]` tweaks)
 - #145275 (fix(compiler/rustc_codegen_llvm): apply `target-cpu` attribute)
 - #145322 (Resolve the prelude import in `build_reduced_graph`)
 - #145331 (Make std use the edition 2024 prelude)
 - #145369 (Do not ICE on private type in field of unresolved struct)
 - #145378 (Add `FnContext` in parser for diagnostic)
 - #145389 ([rustdoc] Revert "rustdoc search: prefer stable items in search results")
 - #145392 (coverage: Remove intermediate data structures from mapping creation)

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 02efea5 into rust-lang:master Aug 15, 2025
10 checks passed
rust-timer added a commit that referenced this pull request Aug 15, 2025
Rollup merge of #145392 - Zalathar:create-mappings, r=petrochenkov

coverage: Remove intermediate data structures from mapping creation

The data structures in `coverage::mappings` were historically very useful for isolating the details of mapping-extraction from the details of how coverage mappings are stored in MIR.

But because of various changes that have taken place over time, they now provide little value, and cause difficulty for the coordinated changes that will be needed for introducing expansion mapping support.

In the future, the pendulum might eventually swing back towards these being useful again, but we can always reintroduce suitable intermediate data structures if and when that happens. For now, the simplicity of not having this intermediate layer is a higher priority.

There should be no changes to compiler output.
@rustbot rustbot added this to the 1.91.0 milestone Aug 15, 2025
@Zalathar Zalathar deleted the create-mappings branch August 15, 2025 12:38
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4 participants