RequirementMachine: Don't crash if we cannot desugar a same-shape requirement

slavapestov · slavapestov · commit 4fa2e979fad6 · 2025-06-17T09:52:02.000-04:00
diff --git a/lib/AST/RequirementMachine/RequirementLowering.cpp b/lib/AST/RequirementMachine/RequirementLowering.cpp
@@ -451,6 +451,7 @@ static void desugarSameShapeRequirement(
       !req.getSecondType()->isParameterPack()) {
     errors.push_back(RequirementError::forInvalidShapeRequirement(
         req, loc));
+    return;
   }
 
   result.emplace_back(RequirementKind::SameShape,
diff --git a/validation-test/compiler_crashers_2_fixed/d48def542970cfa.swift b/validation-test/compiler_crashers_2_fixed/d48def542970cfa.swift
@@ -1,4 +1,4 @@
 // {"signature":"swift::rewriting::performConcreteContraction(llvm::ArrayRef<swift::StructuralRequirement>, llvm::SmallVectorImpl<swift::StructuralRequirement>&, llvm::SmallVectorImpl<swift::rewriting::RequirementError>&, bool)"}
-// RUN: not --crash %target-swift-frontend -typecheck %s
+// RUN: not %target-swift-frontend -typecheck %s
 func a < each b, each c where(repeat(each c each b)) : {
   typealias d<each b> = () func e where d<repeat each b> ==

Original file line number	Diff line number	Diff line change
`@@ -451,6 +451,7 @@ static void desugarSameShapeRequirement(`
`451`	`451`	`!req.getSecondType()->isParameterPack()) {`
`452`	`452`	`errors.push_back(RequirementError::forInvalidShapeRequirement(`
`453`	`453`	`req, loc));`
	`454`	`+ return;`
`454`	`455`	`}`
`455`	`456`
`456`	`457`	`result.emplace_back(RequirementKind::SameShape,`