[OpenCL] Fix checking of vector type casting

[yaxunl]

Summary

Currently clang allows the following code

int a;
int b = (const int) a;

However it does not the following code

int4 a;
int4 b = (const int4) a;

This is because Clang compares the qualified types instead of unqualified types for vector type casting, which causes the inconsistency.

This patch fixes that.

[bader]

LGTM.

cfe/trunk/lib/Sema/SemaExpr.cpp

ExprResult Sema::CheckExtVectorCast(SourceRange R, QualType DestTy,
 
   QualType SrcTy = CastExpr->getType();
 
   // If SrcTy is a VectorType, the total size must match to explicitly cast to
   // an ExtVectorType.
   // In OpenCL, casts between vectors of different types are not allowed.
   // (See OpenCL 6.2).
   if (SrcTy->isVectorType()) {
-    if (!areLaxCompatibleVectorTypes(SrcTy, DestTy)
-        || (getLangOpts().OpenCL &&
-            (DestTy.getCanonicalType() != SrcTy.getCanonicalType()))) {
+    if (!areLaxCompatibleVectorTypes(SrcTy, DestTy) ||
+        (getLangOpts().OpenCL &&
+         !Context.hasSameUnqualifiedType(DestTy, SrcTy))) {
       Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors)
         << DestTy << SrcTy << R;
       return ExprError();
     }
     Kind = CK_BitCast;
     return CastExpr;
   }
 

cfe/trunk/test/SemaOpenCL/vector_conv_invalid.cl

 // RUN: %clang_cc1 -verify %s
 
 typedef unsigned int uint4 __attribute((ext_vector_type(4)));
 typedef int int4 __attribute((ext_vector_type(4)));
 typedef int int3 __attribute((ext_vector_type(3)));
 typedef unsigned uint3 __attribute((ext_vector_type(3)));
 
-void vector_conv_invalid() {
+void vector_conv_invalid(const global int4 *const_global_ptr) {
   uint4 u = (uint4)(1);
   int4 i = u; // expected-error{{initializing 'int4' (vector of 4 'int' values) with an expression of incompatible type 'uint4' (vector of 4 'unsigned int' values)}}
   int4 e = (int4)u; // expected-error{{invalid conversion between ext-vector type 'int4' (vector of 4 'int' values) and 'uint4' (vector of 4 'unsigned int' values)}}
 
   uint3 u4 = (uint3)u; // expected-error{{invalid conversion between ext-vector type 'uint3' (vector of 3 'unsigned int' values) and 'uint4' (vector of 4 'unsigned int' values)}}
+
+  e = (const int4)i;
+  e = (constant int4)i;
+  e = (private int4)i;
+
+  private int4 *private_ptr = (const private int4 *)const_global_ptr; // expected-error{{casting 'const __global int4 *' to type 'const int4 *' changes address space of pointer}}
+  global int4 *global_ptr = const_global_ptr;                 // expected-warning {{initializing '__global int4 *' with an expression of type 'const __global int4 *' discards qualifiers}}
+  global_ptr = (global int4 *)const_global_ptr;
 }