[OpenCL] Harden function pointer diagnostics.

[bader]

Summary

Improve OpenCL type checking by rejecting function pointer types.

[yaxunl]

LGTM. Thanks.

[Anastasia]

LGTM!

include/clang/Basic/DiagnosticSemaKinds.td

 
 def err_invalid_conversion_between_vectors : Error<
   "invalid conversion between vector type%diff{ $ and $|}0,1 of different "
   "size">;
 def err_invalid_conversion_between_vector_and_integer : Error<
   "invalid conversion between vector type %0 and integer type %1 "
   "of different size">;
 
-def err_opencl_function_pointer_variable : Error<
+def err_opencl_function_pointer : Error<
   "pointers to functions are not allowed">;
 
 def err_opencl_taking_function_address : Error<
   "taking address of function is not allowed">;
 
 def err_invalid_conversion_between_vector_and_scalar : Error<
   "invalid conversion between vector type %0 and scalar type %1">;
 

lib/Sema/SemaDecl.cpp

if (NULL == S->getParent()) {
         return nullptr;
       }
     }
 
     // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
     QualType NR = R;
     while (NR->isPointerType()) {
       if (NR->isFunctionPointerType()) {
-        Diag(D.getIdentifierLoc(), diag::err_opencl_function_pointer_variable);
+        Diag(D.getIdentifierLoc(), diag::err_opencl_function_pointer);
         D.setInvalidType();
         break;
       }
       NR = NR->getPointeeType();
     }
 
     if (!getOpenCLOptions().isEnabled("cl_khr_fp16")) {
       // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and

lib/Sema/SemaType.cpp

QualType Sema::BuildPointerType(QualType T,
                                 SourceLocation Loc, DeclarationName Entity) {
   if (T->isReferenceType()) {
     // C++ 8.3.2p4: There shall be no ... pointers to references ...
     Diag(Loc, diag::err_illegal_decl_pointer_to_reference)
       << getPrintableNameForEntity(Entity) << T;
     return QualType();
   }
 
+  if (T->isFunctionType() && getLangOpts().OpenCL) {
+    Diag(Loc, diag::err_opencl_function_pointer);
+    return QualType();
+  }
+
   if (checkQualifiedFunction(*this, T, Loc, QFK_Pointer))
     return QualType();
 
   assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
 
   // In ARC, it is forbidden to build pointers to unqualified pointers.
   if (getLangOpts().ObjCAutoRefCount)
     T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ false);

test/SemaOpenCL/func.cl

 // RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only
 
 // Variadic functions
 void vararg_f(int, ...);                    // expected-error {{invalid prototype, variadic arguments are not allowed in OpenCL}}
 void __vararg_f(int, ...);
 typedef void (*vararg_fptr_t)(int, ...);    // expected-error {{invalid prototype, variadic arguments are not allowed in OpenCL}}
+                                            // expected-error@-1{{pointers to functions are not allowed}}
 int printf(__constant const char *st, ...); // expected-error {{invalid prototype, variadic arguments are not allowed in OpenCL}}
 
+// Struct type with function pointer field
+typedef struct s
+{
+   void (*f)(struct s *self, int *i);       // expected-error{{pointers to functions are not allowed}}
+} s_t;
+
 //Function pointer
 void foo(void*);
 
 void bar()
 {
   // declaring a function pointer is an error
   void (*fptr)(int); // expected-error{{pointers to functions are not allowed}}