[PAC][clang] Correct handling of ptrauth queries of incomplete types

clang/lib/AST/ASTContext.cpp

@@ -1648,6 +1648,9 @@ ASTContext::findPointerAuthContent(QualType T) const {
   if (!RD)
     return PointerAuthContent::None;
 
+  if (RD->isInvalidDecl())
+    return PointerAuthContent::None;
+
   if (auto Existing = RecordContainsAddressDiscriminatedPointerAuth.find(RD);
       Existing != RecordContainsAddressDiscriminatedPointerAuth.end())
     return Existing->second;
@@ -3517,7 +3520,6 @@ static void encodeTypeForFunctionPointerAuth(const ASTContext &Ctx,
 uint16_t ASTContext::getPointerAuthTypeDiscriminator(QualType T) {
   assert(!T->isDependentType() &&
          "cannot compute type discriminator of a dependent type");
-
   SmallString<256> Str;
   llvm::raw_svector_ostream Out(Str);
 

clang/test/SemaCXX/ptrauth-nested-incomplete-types.cpp

@@ -0,0 +1,46 @@
+// RUN: %clang_cc1 -fptrauth-intrinsics -fsyntax-only -ferror-limit 1 -verify -std=c++26 %s
+// RUN: %clang_cc1 -fptrauth-intrinsics -fsyntax-only -ferror-limit 1 -verify -std=c++03 %s
+// RUN: %clang_cc1                      -fsyntax-only -ferror-limit 1 -verify -std=c++03 %s
+
+/// Force two errors so we hit the error limit leading to skip of template instantiation
+# "" // expected-error {{invalid preprocessing directive}}
+# ""
+// expected-error@* {{too many errors emitted}}
+
+template <typename>
+struct a {};
+struct test_polymorphic {
+  virtual ~test_polymorphic();
+  a<int> field;
+};
+static_assert(__is_trivially_relocatable(test_polymorphic));
+
+struct test_struct {
+  test_struct(int) {}
+  void test_instantiate() {
+    test_struct d(0);
+  }
+  void test_type_trait_query() {
+    __is_trivially_relocatable(test_struct);
+  }
+  a<int> e;
+};
+
+struct test_struct2 {
+  test_struct member;
+  void test() {
+    test_struct2 t{.member = {0}};
+  }
+};
+
+struct test_subclass : test_struct {
+   test_subclass() : test_struct(0) {
+   }
+
+   void test_subclass_instantiation() {
+    test_subclass subclass{};
+   }
+  void test_subclass_type_trait_query() {
+    __is_trivially_relocatable(test_subclass);
+  }
+};