[libclang] Check for a record declaration before a template specialization.

[emilio]

Summary

This allows us to get the default template parameters too.

Fixes bug 32539.

[emilio]

Guy, perhaps you could also review this? (Just from looking at the blame log).

Thanks in advance!

[emilio]

Ping?

[emilio]

Closing per advice in cfe-commits@.

clang/test/Index/print-type.cpp

 Specialization<Specialization<bool>& > templRefParam;
 auto autoTemplRefParam = templRefParam;
 
+template<typename T, typename U = int>
+struct DefaultedTypeExample {};
+
+typedef DefaultedTypeExample<int> DefaultedTypeAlias;
+
 // 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: TemplateRef=Baz:9:8 [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: IntegerLiteral= [type=int] [typekind=Int] [isPOD=1]
 // CHECK: TemplateRef=Foo:4:8 [type=] [typekind=Invalid] [isPOD=0]
-// CHECK: FieldDecl=qux:29:38 (Definition) [type=Qux<int, char *, Foo<int>, outer::inner::Bar::FooType>] [typekind=Unexposed] [templateargs/4= [type=int] [typekind=Int] [type=char *] [typekind=Pointer] [type=Foo<int>] [typekind=Unexposed] [type=outer::inner::Bar::FooType] [typekind=Typedef]] [canonicaltype=outer::Qux<int, char *, outer::Foo<int>, int>] [canonicaltypekind=Record] [canonicaltemplateargs/4= [type=int] [typekind=Int] [type=char *] [typekind=Pointer] [type=outer::Foo<int>] [typekind=Record] [type=int] [typekind=Int]] [isPOD=1]
+// CHECK: FieldDecl=qux:29:38 (Definition) [type=Qux<int, char *, Foo<int>, outer::inner::Bar::FooType>] [typekind=Unexposed] [templateargs/4= [type=int] [typekind=Int] [type=char *] [typekind=Pointer] [type=outer::Foo<int>] [typekind=Record] [type=int] [typekind=Int]] [canonicaltype=outer::Qux<int, char *, outer::Foo<int>, int>] [canonicaltypekind=Record] [canonicaltemplateargs/4= [type=int] [typekind=Int] [type=char *] [typekind=Pointer] [type=outer::Foo<int>] [typekind=Record] [type=int] [typekind=Int]] [isPOD=1]
 // CHECK: TemplateRef=Qux:12:8 [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: TemplateRef=Foo:4:8 [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: FunctionTemplate=tbar:36:3 [type=T (int)] [typekind=FunctionProto] [canonicaltype=type-parameter-0-0 (int)] [canonicaltypekind=FunctionProto] [resulttype=T] [resulttypekind=Unexposed] [isPOD=0]

 // 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: TypedefDecl=DefaultedTypeAlias:77:35 (Definition) [type=DefaultedTypeAlias] [typekind=Typedef] [templateargs/2= [type=int] [typekind=Int] [type=int] [typekind=Int]] [canonicaltype=DefaultedTypeExample<int, int>] [canonicaltypekind=Record] [canonicaltemplateargs/2= [type=int] [typekind=Int] [type=int] [typekind=Int]] [isPOD=0]

clang/tools/libclang/CXType.cpp

 static Optional<ArrayRef<TemplateArgument>>
 GetTemplateArguments(QualType Type) {
   assert(!Type.isNull());
-  if (const auto *Specialization = Type->getAs<TemplateSpecializationType>())
-    return Specialization->template_arguments();
-
   if (const auto *RecordDecl = Type->getAsCXXRecordDecl()) {
     const auto *TemplateDecl =
       dyn_cast<ClassTemplateSpecializationDecl>(RecordDecl);

       return TemplateDecl->getTemplateArgs().asArray();
   }
 
+  if (const auto *Specialization = Type->getAs<TemplateSpecializationType>())
+    return Specialization->template_arguments();
+
   return None;
 }