coverage: Avoid a query stability hazard in function_coverage_map
#119514
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
When rust-lang#118865 started enforcing the `rustc::potential_query_instability` lint in `rustc_codegen_llvm`, it added an exemption for this site, arguing that the entries are only used to create a list of filenames that is later sorted. However, the list of entries also gets traversed when creating the function coverage records in LLVM IR, which may be sensitive to hash-based ordering. This patch therefore changes `function_coverage_map` to use `FxIndexMap`, which should avoid hash-based instability by iterating in insertion order.
|
r? @wesleywiser (rustbot has picked a reviewer for you, use r? to override) |
rustbot
added
S-waiting-on-review
|
The detailed comment was very helpful in this case, because I could immediately see that its reasoning was incorrect, which prompted me to do a proper audit of how the list of entries is actually used. |
wesleywiser
approved these changes
Jan 2, 2024
|
🌲 The tree is currently closed for pull requests below priority 100. This pull request will be tested once the tree is reopened. |
bors
added
S-waiting-on-bors
fmease
added a commit
to fmease/rust
that referenced
this pull request
Jan 3, 2024
…wiser coverage: Avoid a query stability hazard in `function_coverage_map` When rust-lang#118865 started enforcing the `rustc::potential_query_instability` lint in `rustc_codegen_llvm`, it added an exemption for this site, arguing that the entries are only used to create a list of filenames that is later sorted. However, the list of entries also gets traversed when creating the function coverage records in LLVM IR, which may be sensitive to hash-based ordering. This patch therefore changes `function_coverage_map` to use `FxIndexMap`, which should avoid hash-based instability by iterating in insertion order. cc `@Enselic`
This was referenced Jan 3, 2024
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Jan 3, 2024
Rollup of 21 pull requests Successful merges: - rust-lang#119086 (Query panic!() to useful diagnostic) - rust-lang#119239 (Remove unnecessary arm in `check_expr_yield`) - rust-lang#119298 (suppress change-tracker warnings in CI containers) - rust-lang#119319 (Document that File does not buffer reads/writes) - rust-lang#119434 (rc: Take *const T in is_dangling) - rust-lang#119444 (Rename `TyCtxt::is_closure` to `TyCtxt::is_closure_or_coroutine`) - rust-lang#119474 (Update tracking issue of naked_functions) - rust-lang#119476 (Pretty-print always-const trait predicates correctly) - rust-lang#119477 (rustdoc ui: adjust tooltip z-index to be above sidebar) - rust-lang#119479 (Remove two unused feature gates from rustc_query_impl) - rust-lang#119487 (Minor improvements in comment on `freshen.rs`) - rust-lang#119492 (Update books) - rust-lang#119494 (Deny defaults for higher-ranked generic parameters) - rust-lang#119498 (Update deadlinks of `strict_provenance` lints) - rust-lang#119505 (Don't synthesize host effect params for trait associated functions marked const) - rust-lang#119510 (Report I/O errors from rmeta encoding with emit_fatal) - rust-lang#119512 (Mark myself as back from leave) - rust-lang#119514 (coverage: Avoid a query stability hazard in `function_coverage_map`) - rust-lang#119523 (llvm: Allow `noundef` in codegen tests) - rust-lang#119534 (Update `thread_local` examples to use `local_key_cell_methods`) - rust-lang#119544 (Fix: Properly set vendor in i686-win7-windows-msvc target) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Jan 3, 2024
Rollup merge of rust-lang#119514 - Zalathar:query-stability, r=wesleywiser coverage: Avoid a query stability hazard in `function_coverage_map` When rust-lang#118865 started enforcing the `rustc::potential_query_instability` lint in `rustc_codegen_llvm`, it added an exemption for this site, arguing that the entries are only used to create a list of filenames that is later sorted. However, the list of entries also gets traversed when creating the function coverage records in LLVM IR, which may be sensitive to hash-based ordering. This patch therefore changes `function_coverage_map` to use `FxIndexMap`, which should avoid hash-based instability by iterating in insertion order. cc ``@Enselic``
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When #118865 started enforcing the
rustc::potential_query_instabilitylint inrustc_codegen_llvm, it added an exemption for this site, arguing that the entries are only used to create a list of filenames that is later sorted.However, the list of entries also gets traversed when creating the function coverage records in LLVM IR, which may be sensitive to hash-based ordering.
This patch therefore changes
function_coverage_mapto useFxIndexMap, which should avoid hash-based instability by iterating in insertion order.cc @Enselic