[OpenCL][PR42033] Fix addr space deduction with template parameters

If dependent types appear in pointers or references we allow addr
space deduction because the addr space in template argument will
belong to the pointee and not the pointer or reference itself.

We also don't diagnose addr space on a function return type after
template instantiation. If any addr space for the return type was
provided on a template parameter this will be diagnosed during the
parsing of template definition.

Differential Revision: https://reviews.llvm.org/D62584

llvm-svn: 366417

clang/lib/Sema/SemaDecl.cpp

@@ -7491,7 +7491,10 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
             return;
           }
         }
-      } else if (T.getAddressSpace() != LangAS::opencl_private) {
+      } else if (T.getAddressSpace() != LangAS::opencl_private &&
+                 // If we are parsing a template we didn't deduce an addr
+                 // space yet.
+                 T.getAddressSpace() != LangAS::Default) {
         // Do not allow other address spaces on automatic variable.
         Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;
         NewVD->setInvalidDecl();

clang/lib/Sema/SemaType.cpp

@@ -7419,7 +7419,9 @@ static void deduceOpenCLImplicitAddrSpace(TypeProcessingState &State,
       (T->isVoidType() && !IsPointee) ||
       // Do not deduce addr spaces for dependent types because they might end
       // up instantiating to a type with an explicit address space qualifier.
-      T->isDependentType() ||
+      // Except for pointer or reference types because the addr space in
+      // template argument can only belong to a pointee.
+      (T->isDependentType() && !T->isPointerType() && !T->isReferenceType()) ||
       // Do not deduce addr space of decltype because it will be taken from
       // its argument.
       T->isDecltypeType() ||

clang/lib/Sema/TreeTransform.h

@@ -5392,13 +5392,6 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
     if (ResultType.isNull())
       return QualType();
 
-    // Return type can not be qualified with an address space.
-    if (ResultType.getAddressSpace() != LangAS::Default) {
-      SemaRef.Diag(TL.getReturnLoc().getBeginLoc(),
-                   diag::err_attribute_address_function_type);
-      return QualType();
-    }
-
     if (getDerived().TransformFunctionTypeParams(
             TL.getBeginLoc(), TL.getParams(),
             TL.getTypePtr()->param_type_begin(),

clang/test/SemaOpenCLCXX/address-space-deduction.cl

@@ -63,3 +63,18 @@ public:
 //CHECK: -CXXConstructorDecl {{.*}} x3<T> 'void (const x3<T> &){{( __attribute__.*)?}} __generic'
 template <typename T>
 x3<T>::x3(const x3<T> &t) {}
+
+template <class T>
+T xxx(T *in) {
+  // This pointer can't be deduced to generic because addr space
+  // will be taken from the template argument.
+  //CHECK: `-VarDecl {{.*}} i 'T *' cinit
+  T *i = in;
+  T ii;
+  return *i;
+}
+
+__kernel void test() {
+  int foo[10];
+  xxx(&foo[0]);
+}

clang/test/SemaOpenCLCXX/address-space-templates.cl

@@ -3,7 +3,7 @@
 template <typename T>
 struct S {
   T a;        // expected-error{{field may not be qualified with an address space}}
-  T f1();     // expected-error{{function type may not be qualified with an address space}}
+  T f1();     // we ignore address space on a return types.
   void f2(T); // expected-error{{parameter may not be qualified with an address space}}
 };