[OpenCL] Improve diagnostics detecting implicit vector conversion.

[pekka.jaaskelainen]

Perhaps the assert() is unneccessary, but otherwise LGTM.

[bader]

Thanks! Committed at rev. 246393.

include/clang/Basic/DiagnosticSemaKinds.td

def err_opencl_global_invalid_addr_space : Error<
   "global variables must have a constant address space qualifier">;
 def err_opencl_no_main : Error<"%select{function|kernel}0 cannot be called 'main'">;
 def err_opencl_kernel_attr :
   Error<"attribute %0 can only be applied to a kernel function">;
 def err_opencl_return_value_with_address_space : Error<
   "return value cannot be qualified with address space">;
 def err_opencl_constant_no_init : Error<
   "variable in constant address space must be initialized">;
+def err_opencl_implicit_vector_conversion : Error<
+  "implicit conversions between vector types (%0 and %1) are not permitted">;
 } // end of sema category
 
 let CategoryName = "OpenMP Issue" in {
 // OpenMP support.
 def err_omp_expected_var_arg : Error<
   "%0 is not a global variable, static local variable or static data member">;
 def err_omp_expected_var_arg_suggest : Error<
   "%0 is not a global variable, static local variable or static data member; "

lib/Sema/SemaExpr.cpp

QualType Sema::CheckVectorOperands(ExprResult &LHS, ExprResult &RHS,
   if ((!RHSVecType && !RHSType->isRealType()) ||
       (!LHSVecType && !LHSType->isRealType())) {
     Diag(Loc, diag::err_typecheck_vector_not_convertable_non_scalar)
       << LHSType << RHSType
       << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
     return QualType();
   }
 
+  // OpenCL V1.1 6.2.6.p1:
+  // If the operands are of more than one vector type, then an error shall
+  // occur. Implicit conversions between vector types are not permitted, per
+  // section 6.2.1.
+  if (getLangOpts().OpenCL &&
+      RHSVecType && isa<ExtVectorType>(RHSVecType) &&
+      LHSVecType && isa<ExtVectorType>(LHSVecType)) {
+    assert(!Context.hasSameType(LHSType, RHSType));
+    Diag(Loc, diag::err_opencl_implicit_vector_conversion) << LHSType
+                                                           << RHSType;
+    return QualType();
+  }
+
   // Otherwise, use the generic diagnostic.
   Diag(Loc, diag::err_typecheck_vector_not_convertable)
     << LHSType << RHSType
     << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
   return QualType();
 }
 
 // checkArithmeticNull - Detect when a NULL constant is used improperly in an

test/SemaOpenCL/cond.cl

 
 uchar2 ntest03(int2 C, uchar X, uchar Y)
 {
   return C ? X : Y; // expected-error {{vector condition type 'int2' (vector of 2 'int' values) and result type (vector of 2 'unsigned char' values) do not have elements of the same size}}
 }
 
 float2 ntest04(int2 C, int2 X, float2 Y)
 {
-  return C ? X : Y; // expected-error {{cannot convert between vector values of different size ('int2' (vector of 2 'int' values) and 'float2' (vector of 2 'float' values))}}
+  return C ? X : Y; // expected-error {{implicit conversions between vector types ('int2' (vector of 2 'int' values) and 'float2' (vector of 2 'float' values)) are not permitted}}
 }
 
 float2 ntest05(int2 C, int2 X, float Y)
 {
   return C ? X : Y; // expected-error {{cannot convert between vector values of different size ('int2' (vector of 2 'int' values) and 'float')}}
 }
 
 char2 ntest06(int2 C, char2 X, char2 Y)

 // Trying to create a int2 vector out of pointers.
 int2 ntest09(int2 C, global int *X, global int *Y)
 {
   return C ? X : Y; // expected-error {{used type '__global int *' where integer or floating point type is required}}
 }
 
 char3 ntest10(char C, char3 X, char2 Y)
 {
-  return C ? X : Y; // expected-error {{cannot convert between vector values of different size ('char3' (vector of 3 'char' values) and 'char2' (vector of 2 'char' values))}}
+  return C ? X : Y; // expected-error {{implicit conversions between vector types ('char3' (vector of 3 'char' values) and 'char2' (vector of 2 'char' values)) are not permitted}}
 }
 
 char3 ntest11(char2 C, char3 X, char Y)
 {
   return C ? X : Y; // expected-error {{vector condition type 'char2' (vector of 2 'char' values) and result type 'char3' (vector of 3 'char' values) do not have the same number of elements}}
 }
 
 int foo1(int);
 int foo2(int);
 
 unsigned int ntest12(int2 C)
 {
   return (unsigned int)(C ? foo1 : foo2); // expected-error {{taking address of function is not allowed}}
 }