[libclang] Fix the type of 'int (Foo);'

[strager]

Summary

libclang exposes the type of 'int (Foo);' (a global variable of type int
called Foo) as CXType_Unexposed. This is because Clang represents Foo's
type as ParenType{BuiltinType{Int}}, and libclang does not handle
ParenType.

Make libclang return CXType_Int as the type of 'int (Foo);' by
unwrapping ParenType transparently.

[strager]

Ping! I'd like a code review for this bug fix.

cfe/trunk/test/Index/paren-type.c

+// RUN: c-index-test -test-print-type %s | FileCheck --check-prefix=CHECK-TYPE %s
+// RUN: c-index-test -test-print-type-declaration %s | FileCheck --check-prefix=CHECK-TYPEDECL %s
+
+// CHECK-TYPE: VarDecl=VariableWithParentheses:
+// CHECK-TYPE-SAME: [type=int] [typekind=Int]
+// CHECK-TYPE-NOT: canonicaltype
+// CHECK-TYPE-SAME: isPOD
+extern int (VariableWithParentheses);
+
+typedef int MyTypedef;
+// CHECK-TYPE: VarDecl=VariableWithParentheses2:
+// CHECK-TYPE-SAME: [type=MyTypedef] [typekind=Typedef]
+// CHECK-TYPE-SAME: [canonicaltype=int] [canonicaltypekind=Int]
+// CHECK-TYPEDECL: VarDecl=VariableWithParentheses2
+// CHECK-TYPEDECL-SAME: [typedeclaration=MyTypedef] [typekind=Typedef]
+extern MyTypedef (VariableWithParentheses2);

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

 // RUN: c-index-test -test-print-type %s | FileCheck %s
 // CHECK: FunctionDecl=f:3:6 (Definition) [type=int *(int *, char *, FooType, int *, void (*)(int))] [typekind=FunctionProto] [canonicaltype=int *(int *, char *, int, int *, void (*)(int))] [canonicaltypekind=FunctionProto] [resulttype=int *] [resulttypekind=Pointer] [args= [int *] [Pointer] [char *] [Pointer] [FooType] [Typedef] [int [5]] [ConstantArray] [void (*)(int)] [Pointer]] [isPOD=0]
 // CHECK: ParmDecl=p:3:13 (Definition) [type=int *] [typekind=Pointer] [isPOD=1] [pointeetype=int] [pointeekind=Int]
 // CHECK: ParmDecl=x:3:22 (Definition) [type=char *] [typekind=Pointer] [isPOD=1] [pointeetype=char] [pointeekind=Char_{{[US]}}]
 // CHECK: ParmDecl=z:3:33 (Definition) [type=FooType] [typekind=Typedef] [canonicaltype=int] [canonicaltypekind=Int] [isPOD=1]
 // CHECK: TypeRef=FooType:1:13 [type=FooType] [typekind=Typedef] [canonicaltype=int] [canonicaltypekind=Int] [isPOD=1]
 // CHECK: ParmDecl=arr:3:40 (Definition) [type=int [5]] [typekind=ConstantArray] [isPOD=1]
 // CHECK: IntegerLiteral= [type=int] [typekind=Int] [isPOD=1]
-// CHECK: ParmDecl=fn:3:55 (Definition) [type=void (*)(int)] [typekind=Pointer] [canonicaltype=void (*)(int)] [canonicaltypekind=Pointer] [isPOD=1] [pointeetype=void (int)] [pointeekind=Unexposed]
+// CHECK: ParmDecl=fn:3:55 (Definition) [type=void (*)(int)] [typekind=Pointer] [canonicaltype=void (*)(int)] [canonicaltypekind=Pointer] [isPOD=1] [pointeetype=void (int)] [pointeekind=FunctionProto]
 // CHECK: ParmDecl=:3:62 (Definition) [type=int] [typekind=Int] [isPOD=1]
 // CHECK: CompoundStmt= [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: CallExpr=fn:3:55 [type=void] [typekind=Void] [args= [int] [Int]] [isPOD=0]
-// CHECK: DeclRefExpr=fn:3:55 [type=void (*)(int)] [typekind=Pointer] [canonicaltype=void (*)(int)] [canonicaltypekind=Pointer] [isPOD=1] [pointeetype=void (int)] [pointeekind=Unexposed]
+// CHECK: DeclRefExpr=fn:3:55 [type=void (*)(int)] [typekind=Pointer] [canonicaltype=void (*)(int)] [canonicaltypekind=Pointer] [isPOD=1] [pointeetype=void (int)] [pointeekind=FunctionProto]
 // CHECK: UnaryOperator= [type=int] [typekind=Int] [isPOD=1]
 // CHECK: DeclRefExpr=p:3:13 [type=int *] [typekind=Pointer] [isPOD=1] [pointeetype=int] [pointeekind=Int]
 // CHECK: DeclStmt= [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: VarDecl=w:5:17 (Definition) [type=const FooType] [typekind=Typedef] const [canonicaltype=const int] [canonicaltypekind=Int] [isPOD=1]
 // CHECK: TypeRef=FooType:1:13 [type=FooType] [typekind=Typedef] [canonicaltype=int] [canonicaltypekind=Int] [isPOD=1]
 // CHECK: DeclRefExpr=z:3:33 [type=FooType] [typekind=Typedef] [canonicaltype=int] [canonicaltypekind=Int] [isPOD=1]
 // CHECK: ReturnStmt= [type=] [typekind=Invalid] [isPOD=0]
 // CHECK: BinaryOperator= [type=int *] [typekind=Pointer] [isPOD=1] [pointeetype=int] [pointeekind=Int]

cfe/trunk/tools/libclang/CXType.cpp

 CXType cxtype::MakeCXType(QualType T, CXTranslationUnit TU) {
   CXTypeKind TK = CXType_Invalid;
 
   if (TU && !T.isNull()) {
     // Handle attributed types as the original type
     if (auto *ATT = T->getAs<AttributedType>()) {
       return MakeCXType(ATT->getModifiedType(), TU);
     }
+    // Handle paren types as the original type
+    if (auto *PTT = T->getAs<ParenType>()) {
+      return MakeCXType(PTT->getInnerType(), TU);
+    }
 
     ASTContext &Ctx = cxtu::getASTUnit(TU)->getASTContext();
     if (Ctx.getLangOpts().ObjC1) {
       QualType UnqualT = T.getUnqualifiedType();
       if (Ctx.isObjCIdType(UnqualT))
         TK = CXType_ObjCId;
       else if (Ctx.isObjCClassType(UnqualT))
         TK = CXType_ObjCClass;