[libclang] [OpenCL] Expose half type

[svenvh]

Summary

Expose the half type (fp16) through libclang and the python bindings.

It seems CXType_LastBuiltin was not updated in b2ea6d9 ("Enable
support for __float128 in Clang", 2016-04-13), so update it now.

Add an Index test for OpenCL types; in the future we will add other
OpenCL types such as images to this test.

[yaxunl]

LGTM. Thanks!

bindings/python/clang/cindex.py

 TypeKind.LONGDOUBLE = TypeKind(23)
 TypeKind.NULLPTR = TypeKind(24)
 TypeKind.OVERLOAD = TypeKind(25)
 TypeKind.DEPENDENT = TypeKind(26)
 TypeKind.OBJCID = TypeKind(27)
 TypeKind.OBJCCLASS = TypeKind(28)
 TypeKind.OBJCSEL = TypeKind(29)
 TypeKind.FLOAT128 = TypeKind(30)
+TypeKind.HALF = TypeKind(31)
 TypeKind.COMPLEX = TypeKind(100)
 TypeKind.POINTER = TypeKind(101)
 TypeKind.BLOCKPOINTER = TypeKind(102)
 TypeKind.LVALUEREFERENCE = TypeKind(103)
 TypeKind.RVALUEREFERENCE = TypeKind(104)
 TypeKind.RECORD = TypeKind(105)
 TypeKind.ENUM = TypeKind(106)
 TypeKind.TYPEDEF = TypeKind(107)

include/clang-c/Index.h

enum CXTypeKind {
   CXType_LongDouble = 23,
   CXType_NullPtr = 24,
   CXType_Overload = 25,
   CXType_Dependent = 26,
   CXType_ObjCId = 27,
   CXType_ObjCClass = 28,
   CXType_ObjCSel = 29,
   CXType_Float128 = 30,
+  CXType_Half = 31,
   CXType_FirstBuiltin = CXType_Void,
-  CXType_LastBuiltin  = CXType_ObjCSel,
+  CXType_LastBuiltin  = CXType_Half,
 
   CXType_Complex = 100,
   CXType_Pointer = 101,
   CXType_BlockPointer = 102,
   CXType_LValueReference = 103,
   CXType_RValueReference = 104,
   CXType_Record = 105,
   CXType_Enum = 106,

test/Index/opencl-types.cl

+// RUN: c-index-test -test-print-type %s | FileCheck %s
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+typedef half half4 __attribute__((ext_vector_type(4)));
+typedef float float4 __attribute__((ext_vector_type(4)));
+typedef double double4 __attribute__((ext_vector_type(4)));
+
+void kernel testFloatTypes() {
+  half scalarHalf;
+  half4 vectorHalf;
+  float scalarFloat;
+  float4 vectorFloat;
+  double scalarDouble;
+  double4 vectorDouble;
+}
+
+// CHECK: VarDecl=scalarHalf:11:8 (Definition) [type=half] [typekind=Half] [isPOD=1]
+// CHECK: VarDecl=vectorHalf:12:9 (Definition) [type=half4] [typekind=Typedef] [canonicaltype=half __attribute__((ext_vector_type(4)))] [canonicaltypekind=Unexposed] [isPOD=1]
+// CHECK: VarDecl=scalarFloat:13:9 (Definition) [type=float] [typekind=Float] [isPOD=1]
+// CHECK: VarDecl=vectorFloat:14:10 (Definition) [type=float4] [typekind=Typedef] [canonicaltype=float __attribute__((ext_vector_type(4)))] [canonicaltypekind=Unexposed] [isPOD=1]
+// CHECK: VarDecl=scalarDouble:15:10 (Definition) [type=double] [typekind=Double] [isPOD=1]
+// CHECK: VarDecl=vectorDouble:16:11 (Definition) [type=double4] [typekind=Typedef] [canonicaltype=double __attribute__((ext_vector_type(4)))] [canonicaltypekind=Unexposed] [isPOD=1]

tools/libclang/CXType.cpp

switch (BT->getKind()) {
     BTCASE(SChar);
     case BuiltinType::WChar_S: return CXType_WChar;
     case BuiltinType::WChar_U: return CXType_WChar;
     BTCASE(Short);
     BTCASE(Int);
     BTCASE(Long);
     BTCASE(LongLong);
     BTCASE(Int128);
+    BTCASE(Half);
     BTCASE(Float);
     BTCASE(Double);
     BTCASE(LongDouble);
     BTCASE(Float128);
     BTCASE(NullPtr);
     BTCASE(Overload);
     BTCASE(Dependent);
     BTCASE(ObjCId);
switch (K) {
     TKIND(Char_S);
     TKIND(SChar);
     case CXType_WChar: s = "WChar"; break;
     TKIND(Short);
     TKIND(Int);
     TKIND(Long);
     TKIND(LongLong);
     TKIND(Int128);
+    TKIND(Half);
     TKIND(Float);
     TKIND(Double);
     TKIND(LongDouble);
     TKIND(Float128);
     TKIND(NullPtr);
     TKIND(Overload);
     TKIND(Dependent);
     TKIND(ObjCId);