[swiftsrc2cpg] De-sugar tuple patterns in switch-case statements#5913
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max-leuthaeuser merged 2 commits intomasterfrom Apr 1, 2026
Merged
[swiftsrc2cpg] De-sugar tuple patterns in switch-case statements#5913max-leuthaeuser merged 2 commits intomasterfrom
max-leuthaeuser merged 2 commits intomasterfrom
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When a switch-case contains tuple patterns, the subject expression is assigned to a temporary variable evaluated once: - Expression tuple patterns (e.g. `case (1, 2):`) are de-sugared into component-wise equality chains (`<subject>.0 == 1 && <subject>.1 == 2`) - Binding tuple patterns (e.g. `case let (a, b):` or `case (var a, var b):`) are de-sugared into component-wise assignments (`a = <subject>.0`) - `is Type` patterns in tuples (e.g. `case (is String, 42):`) produce `instanceOf` checks - Enum case patterns (e.g. `case (.min, 0):`) produce equality checks - Mixed binding and non-binding elements (e.g. `case (var a, .min):`) are handled correctly - Nested tuples are handled recursively Tuple elements are accessed using Swift's 0-based numeric labels (`.0`, `.1`, ...) rather than Scala-style `._1`, `._2`.
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- Add data-flow tests for equality chain (source flows through equals checks and into sink) in DataFlowTests - Replace .size shouldBe X assertions with content checks in SwitchTests - Set typeFullName of subject temp local/identifiers to Defines.Tuple - Fix missing scope.addVariable for subject temp (prevented spurious second local from being created by createVariableReferenceLinks) - Add type assertions for subject temp
ml86
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Mar 31, 2026
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When a switch-case contains tuple patterns, the subject expression is
assigned to a temporary variable evaluated once:
case (1, 2):) are de-sugared intocomponent-wise equality chains (
<subject>.0 == 1 && <subject>.1 == 2)case let (a, b):orcase (var a, var b):)are de-sugared into component-wise assignments (
a = <subject>.0)is Typepatterns in tuples (e.g.case (is String, 42):) produceinstanceOfcheckscase (.min, 0):) produce equality checkscase (var a, .min):)are handled correctly
.0,.1, etc.