[Clang] Ensure correct parameters are in the scope for constraint equivalence checking

clang/docs/ReleaseNotes.rst

@@ -808,6 +808,7 @@ Bug Fixes in This Version
   nested scopes. (#GH147495)
 - Fixed a failed assertion with an operator call expression which comes from a
   macro expansion when performing analysis for nullability attributes. (#GH138371)
+- Fixed a concept equivalent checking crash due to untransformed constraint expressions. (#GH146614)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Sema/SemaConcept.cpp

@@ -925,7 +925,12 @@ static const Expr *SubstituteConstraintExpressionWithoutSatisfaction(
       ND && ND->isFunctionOrFunctionTemplate()) {
     ScopeForParameters.emplace(S, /*CombineWithOuterScope=*/true);
     const FunctionDecl *FD = ND->getAsFunction();
+    if (FunctionTemplateDecl *Template = FD->getDescribedFunctionTemplate();
+        Template && Template->getInstantiatedFromMemberTemplate())
+      FD = Template->getInstantiatedFromMemberTemplate()->getTemplatedDecl();
     for (auto *PVD : FD->parameters()) {
+      if (ScopeForParameters->getInstantiationOfIfExists(PVD))
+        continue;
       if (!PVD->isParameterPack()) {
         ScopeForParameters->InstantiatedLocal(PVD, PVD);
         continue;

clang/test/SemaTemplate/concepts-using-decl.cpp

@@ -176,3 +176,24 @@ void func() {
   f.foo<10, 10>(); // expected-error {{no matching member function for call to 'foo'}}
 }
 } // namespace heads_without_concepts.
+
+namespace GH146614 {
+
+template <typename T>
+struct base {
+    template <typename A>
+    void foo(A x)
+        requires (requires{x;})
+    {}
+};
+
+
+struct child : base<int> {
+  using base<int>::foo;
+  template <typename A>
+  void foo(A x)
+      requires (false)
+  {}
+};
+
+}