[OpenCL] Defines helper function for OpenCL default address space

Helper function `getDefaultOpenCLPointeeAddrSpace()` introduced to
`ASTContext` class. It returns default OpenCL address space
depending on language version and enabled features. If generic
address space is supported, the helper function returns value
`LangAS::opencl_generic`. Otherwise, value `LangAS::opencl_private`
is returned. Code refactoring changes performed in several suitable
places.

Differential Revision: https://reviews.llvm.org/D109874

clang/include/clang/AST/ASTContext.h

@@ -1362,6 +1362,12 @@ public:
   /// Get address space for OpenCL type.
   LangAS getOpenCLTypeAddrSpace(const Type *T) const;
 
+  /// Returns default address space based on OpenCL version and enabled features
+  inline LangAS getDefaultOpenCLPointeeAddrSpace() {
+    return LangOpts.OpenCLGenericAddressSpace ? LangAS::opencl_generic
+                                              : LangAS::opencl_private;
+  }
+
   void setcudaConfigureCallDecl(FunctionDecl *FD) {
     cudaConfigureCallDecl = FD;
   }

clang/lib/AST/Expr.cpp

@@ -3779,11 +3779,8 @@ Expr::isNullPointerConstant(ASTContext &Ctx,
         // has non-default address space it is not treated as nullptr.
         // (__generic void*)0 in OpenCL 2.0 should not be treated as nullptr
         // since it cannot be assigned to a pointer to constant address space.
-        if ((Ctx.getLangOpts().OpenCLVersion >= 200 &&
-             Pointee.getAddressSpace() == LangAS::opencl_generic) ||
-            (Ctx.getLangOpts().OpenCL &&
-             Ctx.getLangOpts().OpenCLVersion < 200 &&
-             Pointee.getAddressSpace() == LangAS::opencl_private))
+        if (Ctx.getLangOpts().OpenCL &&
+            Pointee.getAddressSpace() == Ctx.getDefaultOpenCLPointeeAddrSpace())
           Qs.removeAddressSpace();
 
         if (Pointee->isVoidType() && Qs.empty() && // to void*

clang/lib/Sema/Sema.cpp

@@ -1430,7 +1430,7 @@ NamedDecl *Sema::getCurFunctionOrMethodDecl() {
 
 LangAS Sema::getDefaultCXXMethodAddrSpace() const {
   if (getLangOpts().OpenCL)
-    return LangAS::opencl_generic;
+    return getASTContext().getDefaultOpenCLPointeeAddrSpace();
   return LangAS::Default;
 }
 

clang/lib/Sema/SemaTemplateDeduction.cpp

@@ -3894,8 +3894,9 @@ static bool AdjustFunctionParmAndArgTypesForDeduction(
     //   "lvalue reference to A" is used in place of A for type deduction.
     if (isForwardingReference(QualType(ParamRefType, 0), FirstInnerIndex) &&
         Arg->isLValue()) {
-      if (S.getLangOpts().OpenCL  && !ArgType.hasAddressSpace())
-        ArgType = S.Context.getAddrSpaceQualType(ArgType, LangAS::opencl_generic);
+      if (S.getLangOpts().OpenCL && !ArgType.hasAddressSpace())
+        ArgType = S.Context.getAddrSpaceQualType(
+            ArgType, S.Context.getDefaultOpenCLPointeeAddrSpace());
       ArgType = S.Context.getLValueReferenceType(ArgType);
     }
   } else {

clang/lib/Sema/SemaType.cpp

@@ -2092,9 +2092,7 @@ static QualType deduceOpenCLPointeeAddrSpace(Sema &S, QualType PointeeType) {
       !PointeeType->isSamplerT() &&
       !PointeeType.hasAddressSpace())
     PointeeType = S.getASTContext().getAddrSpaceQualType(
-        PointeeType, S.getLangOpts().OpenCLGenericAddressSpace
-                         ? LangAS::opencl_generic
-                         : LangAS::opencl_private);
+        PointeeType, S.getASTContext().getDefaultOpenCLPointeeAddrSpace());
   return PointeeType;
 }