python: wildcard case is not default case - #22526
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Copilot review overview
🟡 Changes recommended
Regression coverage is needed for a guarded wildcard followed by another case.
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Review tier: Balanced
Findings: 1
New issues introduced by this change (1)
| Severity | Finding |
|---|---|
 |
python/ql/lib/semmle/python/controlflow/internal/AstNodeImpl.qll — Add regression coverage for guarded wildcard ordering |
What changed in this PR
Corrects Python wildcard-case CFG ordering by treating case _: as match-all rather than default.
Changes:
- Makes
DefaultCaseempty. - Classifies wildcard cases through
matchAll.
| File | Description |
|---|---|
python/ql/lib/semmle/python/controlflow/internal/AstNodeImpl.qll |
Corrects wildcard-case CFG classification. |
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| /** A wildcard case (`case _:`). */ | ||
| class DefaultCase extends Case { | ||
| DefaultCase() { this.isWildcard() } | ||
| DefaultCase() { none() } |
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Reclassifying should be caught by the consistency checks. The test code you propose would leave dead code. Still, it is a valid suggestion, perhaps case _ if cond: then case _: would be even better.
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A wildcard case (
case _:) should not be considered default as the CFG library will then order it last.Instead it is a
matchAll. Revealed by #22510.