[libclang] Return the proper pointee type for 'auto' deduced to pointer

[yvvan]

Summary

Currently the resulting type is always invalid in such case.

[michaelwu]

It shouldn't be too hard to make a test using c-index-test. -test-print-type will print out the pointee type if it's valid.

tools/libclang/CXType.cpp

448 ↗

(On Diff #162617)

Seems like this might make sense for Type::DeducedTemplateSpecialization too.

[yvvan]

You are completely right! Thanks!
I did not think that -test-print-type also checks for the pointee.

[yvvan]

Comments addressed

[michaelwu]

LGTM

cfe/trunk/test/Index/print-type.cpp

 
 Specialization<Specialization<bool>& > templRefParam;
 auto autoTemplRefParam = templRefParam;
 
 template<typename T> struct A {};
 template<typename T> using C = T;
 using baz = C<A<void>>;
 
+auto autoTemplPointer = &autoTemplRefParam;
+
 // RUN: c-index-test -test-print-type %s -std=c++14 | FileCheck %s
 // CHECK: Namespace=outer:1:11 (Definition) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: ClassTemplate=Foo:4:8 (Definition) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: TemplateTypeParameter=T:3:19 (Definition) [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]
 // CHECK: FieldDecl=t:5:5 (Definition) [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]
 // CHECK: TypeRef=T:3:19 [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]
 // CHECK: ClassTemplate=Baz:9:8 (Definition) [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: TemplateTypeParameter=T:8:20 (Definition) [type=T] [typekind=Unexposed] [canonicaltype=type-parameter-0-0] [canonicaltypekind=Unexposed] [isPOD=0]

 // CHECK: StructDecl=Specialization:69:8 [Specialization of Specialization:66:8] [type=Specialization<int>] [typekind=Record] [templateargs/1= [type=int] [typekind=Int]] [isPOD=0]
 // CHECK: VarDecl=templRefParam:71:40 (Definition) [type=Specialization<Specialization<bool> &>] [typekind=Unexposed] [templateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [canonicaltype=Specialization<Specialization<bool> &>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [isPOD=1]
 // CHECK: TemplateRef=Specialization:66:8 [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: CallExpr=Specialization:66:8 [type=Specialization<Specialization<bool> &>] [typekind=Unexposed] [templateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [canonicaltype=Specialization<Specialization<bool> &>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [isPOD=1]
 // CHECK: VarDecl=autoTemplRefParam:72:6 (Definition) [type=Specialization<Specialization<bool> &>] [typekind=Auto] [templateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [canonicaltype=Specialization<Specialization<bool> &>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [isPOD=1]
 // CHECK: UnexposedExpr=templRefParam:71:40 [type=const Specialization<Specialization<bool> &>] [typekind=Unexposed] const [templateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [canonicaltype=const Specialization<Specialization<bool> &>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [isPOD=1]
 // CHECK: DeclRefExpr=templRefParam:71:40 [type=Specialization<Specialization<bool> &>] [typekind=Unexposed] [templateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [canonicaltype=Specialization<Specialization<bool> &>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=Specialization<bool> &] [typekind=LValueReference]] [isPOD=1]
 // CHECK: TypeAliasDecl=baz:76:7 (Definition) [type=baz] [typekind=Typedef] [templateargs/1= [type=A<void>] [typekind=Unexposed]] [canonicaltype=A<void>] [canonicaltypekind=Record] [canonicaltemplateargs/1= [type=void] [typekind=Void]] [isPOD=0]
+// CHECK: VarDecl=autoTemplPointer:78:6 (Definition) [type=Specialization<Specialization<bool> &> *] [typekind=Auto] [canonicaltype=Specialization<Specialization<bool> &> *] [canonicaltypekind=Pointer] [isPOD=1] [pointeetype=Specialization<Specialization<bool> &>] [pointeekind=Record]

cfe/trunk/tools/libclang/CXType.cpp

 
 CXType clang_getPointeeType(CXType CT) {
   QualType T = GetQualType(CT);
   const Type *TP = T.getTypePtrOrNull();
 
   if (!TP)
     return MakeCXType(QualType(), GetTU(CT));
 
+try_again:
   switch (TP->getTypeClass()) {
     case Type::Pointer:
       T = cast<PointerType>(TP)->getPointeeType();
       break;
     case Type::BlockPointer:
       T = cast<BlockPointerType>(TP)->getPointeeType();
       break;
     case Type::LValueReference:
     case Type::RValueReference:
       T = cast<ReferenceType>(TP)->getPointeeType();
       break;
     case Type::ObjCObjectPointer:
       T = cast<ObjCObjectPointerType>(TP)->getPointeeType();
       break;
     case Type::MemberPointer:
       T = cast<MemberPointerType>(TP)->getPointeeType();
       break;
+    case Type::Auto:
+    case Type::DeducedTemplateSpecialization:
+      TP = cast<DeducedType>(TP)->getDeducedType().getTypePtrOrNull();
+      if (TP)
+        goto try_again;
+      break;
     default:
       T = QualType();
       break;
   }
   return MakeCXType(T, GetTU(CT));
 }
 
 CXCursor clang_getTypeDeclaration(CXType CT) {