Rust: Fix variable access overlap #20727
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Pull Request Overview
This PR fixes a bug in variable access resolution where a single variable access could incorrectly resolve to multiple variable declarations. The fix adjusts the scope resolution logic to prevent this overlap by ensuring that if a candidate is itself a VariableScope, it's not also treated as being enclosed by a scope.
Key Changes
- Modified scope resolution logic in
VariableImpl.qllto prevent double-counting of variable scopes - Added a new test case (
match_pattern15) demonstrating the fix - Added consistency query infrastructure to detect variable resolution issues
Reviewed Changes
Copilot reviewed 6 out of 7 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| rust/ql/lib/codeql/rust/elements/internal/VariableImpl.qll | Fixed scope resolution to prevent a variable access from resolving to multiple variables |
| rust/ql/test/library-tests/variables/main.rs | Added test case match_pattern15 demonstrating the overlap issue |
| rust/ql/test/library-tests/variables/variables.expected | Updated test expectations with new variable declarations and accesses |
| rust/ql/test/library-tests/variables/Ssa.expected | Updated SSA analysis expectations following the fix |
| rust/ql/lib/codeql/rust/internal/VariableConsistency.qll | Added query predicate to detect multiple variable targets |
| rust/ql/consistency-queries/VariableConsistency.ql | Added consistency query to list variable inconsistencies |
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geoffw0
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Oct 31, 2025
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LGTM, quick question about the consistency query...
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Fixes an issue where a variable access could resolve to multiple variables (see test code for example).
DCA looks good.