[clang] [clang-tools-extra] [clang] [Sema] Preserve nested name specifier prefix in MemberPointerType (PR #118236)

[Nathan Ridge via cfe-commits]

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@@ -5347,13 +5347,16 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
 
         case NestedNameSpecifier::TypeSpec:
         case NestedNameSpecifier::TypeSpecWithTemplate:
-          ClsType = QualType(NNS->getAsType(), 0);
+          const Type *NNSType = NNS->getAsType();
+          ClsType = QualType(NNSType, 0);
           // Note: if the NNS has a prefix and ClsType is a nondependent
-          // TemplateSpecializationType, then the NNS prefix is NOT included
-          // in ClsType; hence we wrap ClsType into an ElaboratedType.
-          // NOTE: in particular, no wrap occurs if ClsType already is an
-          // Elaborated, DependentName, or DependentTemplateSpecialization.
-          if (isa<TemplateSpecializationType>(NNS->getAsType()))
+          // TemplateSpecializationType or a RecordType, then the NNS prefix is
+          // NOT included in ClsType; hence we wrap ClsType into an
+          // ElaboratedType. NOTE: in particular, no wrap occurs if ClsType
+          // already is an Elaborated, DependentName, or
+          // DependentTemplateSpecialization.
+          if (isa<TemplateSpecializationType>(NNSType) ||
+              (NNSPrefix && isa<RecordType>(NNSType)))
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HighCommander4 wrote:

> The assert is still viable and would be helpful

FWIW, I did try adding back the assert to see what other sorts of types we get in this codepath. I found the following:

 * `TemplateTypeParmType` (seen in SemaCXX/err_init_conversion_failed.cpp)
 * `TypedefType` (seen in CXX/drs/cwg3xx.cpp)
 * `DecltypeType` (seen in CXX/expr/expr_prim/expr_prim_general/p8-0x.cpp)
 * `InjectedClassNameType` (seen in CXX/temp/temp_decls/temp_variadic/p5.cpp)
 * `UsingType` (seen in Modules/using-decl.cpp)

It's not clear to me what sort of handling we'd want for these various types.

https://github.com/llvm/llvm-project/pull/118236