Sema: Fix spurious diagnostic about move-only tuples

slavapestov · slavapestov · commit 21214bea3ca1 · 2025-10-03T14:24:10.000-04:00
diff --git a/lib/Sema/TypeCheckType.cpp b/lib/Sema/TypeCheckType.cpp
@@ -5992,7 +5992,7 @@ NeverNullType TypeResolver::resolveTupleType(TupleTypeRepr *repr,
         !isa<TupleTypeRepr>(tyR)) {
       auto contextTy = GenericEnvironment::mapTypeIntoContext(
           resolution.getGenericSignature().getGenericEnvironment(), ty);
-      if (contextTy->isNoncopyable())
+      if (!contextTy->hasError() && contextTy->isNoncopyable())
         moveOnlyElementIndex = i;
     }
 
diff --git a/test/Constraints/moveonly_tuples.swift b/test/Constraints/moveonly_tuples.swift
@@ -23,3 +23,7 @@ func inferredTuples<T>(x: Int, y: borrowing Butt, z: T) {
     _ = b
     _ = c
 }
+
+// Avoid spurious diagnostic with the tuple here
+func bogus<T>(_: T, _: (T, T)) where T == DoesNotExist {}
+// expected-error@-1 {{cannot find type 'DoesNotExist' in scope}}

Original file line number	Diff line number	Diff line change
`@@ -5992,7 +5992,7 @@ NeverNullType TypeResolver::resolveTupleType(TupleTypeRepr *repr,`
`5992`	`5992`	`!isa<TupleTypeRepr>(tyR)) {`
`5993`	`5993`	`auto contextTy = GenericEnvironment::mapTypeIntoContext(`
`5994`	`5994`	`resolution.getGenericSignature().getGenericEnvironment(), ty);`
`5995`		`- if (contextTy->isNoncopyable())`
	`5995`	`+ if (!contextTy->hasError() && contextTy->isNoncopyable())`
`5996`	`5996`	`moveOnlyElementIndex = i;`
`5997`	`5997`	`}`
`5998`	`5998`
Original file line number	Diff line number	Diff line change
`@@ -23,3 +23,7 @@ func inferredTuples<T>(x: Int, y: borrowing Butt, z: T) {`
`23`	`23`	`_ = b`
`24`	`24`	`_ = c`
`25`	`25`	`}`
	`26`	`+`
	`27`	`+// Avoid spurious diagnostic with the tuple here`
	`28`	`+func bogus<T>(_: T, _: (T, T)) where T == DoesNotExist {}`
	`29`	`+// expected-error@-1 {{cannot find type 'DoesNotExist' in scope}}`