[SYCL] Replace hardcoded namespaces with attribute (#6674)

Namespaces were hardcoded and used in compiler to
check for various SYCL types including accessors,
spec_constants, etc. This patch implements an
attribute to uniquely identify the types instead.
Attribute argument is an Identifier which denotes
 each type.

E.g. __attribute__((sycl_type(accessor)) is used 
to mark accessor class.

The attribute has been implemented as with an
accepted list of arguments via EnumArg. The attribute
definition should be updated to support any new types.

The attribute takes 1 argument.

Fixes: #5186

Signed-off-by: Elizabeth Andrews <[email protected]>

Author: elizabethandrews

clang/include/clang/Basic/Attr.td

@@ -1281,6 +1281,23 @@ def SYCLSpecialClass: InheritableAttr {
   let Documentation = [SYCLSpecialClassDocs];
 }
 
+def SYCLType: InheritableAttr {
+  let Spellings = [CXX11<"__sycl_detail__", "sycl_type">];
+  let Subjects = SubjectList<[CXXRecord, Enum], ErrorDiag>;
+  let LangOpts = [SYCLIsDevice, SYCLIsHost];
+  let Args = [EnumArgument<"Type", "SYCLType",
+                           ["accessor", "local_accessor", "spec_constant",
+                            "specialization_id", "kernel_handler", "buffer_location",
+                            "no_alias", "accessor_property_list", "group",
+                            "private_memory", "aspect"],
+                           ["accessor", "local_accessor", "spec_constant",
+                            "specialization_id", "kernel_handler", "buffer_location",
+                            "no_alias", "accessor_property_list", "group",
+                            "private_memory", "aspect"]>];
+  // Only used internally by SYCL implementation
+  let Documentation = [InternalOnly];
+}
+
 def SYCLDeviceHas : InheritableAttr {
   let Spellings = [CXX11<"sycl", "device_has">];
   let Subjects = SubjectList<[Function], ErrorDiag>;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -4098,6 +4098,8 @@ def warn_transparent_union_attribute_zero_fields : Warning<
 def warn_attribute_type_not_supported : Warning<
   "%0 attribute argument not supported: %1">,
   InGroup<IgnoredAttributes>;
+def err_attribute_argument_not_supported : Error<
+  "%0 attribute argument %1 is not supported">;
 def warn_attribute_unknown_visibility : Warning<"unknown visibility %0">,
   InGroup<IgnoredAttributes>;
 def warn_attribute_protected_visibility :

clang/include/clang/Sema/Sema.h

@@ -10858,6 +10858,9 @@ class Sema final {
   ReqdWorkGroupSizeAttr *
   MergeReqdWorkGroupSizeAttr(Decl *D, const ReqdWorkGroupSizeAttr &A);
 
+  SYCLTypeAttr *MergeSYCLTypeAttr(Decl *D, const AttributeCommonInfo &CI,
+                                  SYCLTypeAttr::SYCLType TypeName);
+
   /// Only called on function definitions; if there is a MSVC #pragma optimize
   /// in scope, consider changing the function's attributes based on the
   /// optimization list passed to the pragma.
@@ -13546,12 +13549,16 @@ class Sema final {
     const CXXRecordDecl *RecTy = Ty->getAsCXXRecordDecl();
     if (!RecTy)
       return false;
+
+    if (RecTy->hasAttr<AttrTy>())
+      return true;
+
     if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RecTy)) {
       ClassTemplateDecl *Template = CTSD->getSpecializedTemplate();
       if (CXXRecordDecl *RD = Template->getTemplatedDecl())
         return RD->hasAttr<AttrTy>();
     }
-    return RecTy->hasAttr<AttrTy>();
+    return false;
   }
 
 private:

clang/lib/Sema/SemaDecl.cpp

@@ -2918,6 +2918,8 @@ static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
     NewAttr = S.MergeSYCLDeviceHasAttr(D, *A);
   else if (const auto *A = dyn_cast<SYCLUsesAspectsAttr>(Attr))
     NewAttr = S.MergeSYCLUsesAspectsAttr(D, *A);
+  else if (const auto *A = dyn_cast<SYCLTypeAttr>(Attr))
+    NewAttr = S.MergeSYCLTypeAttr(D, *A, A->getType());
   else if (const auto *A = dyn_cast<SYCLIntelPipeIOAttr>(Attr))
     NewAttr = S.MergeSYCLIntelPipeIOAttr(D, *A);
   else if (const auto *A = dyn_cast<SYCLIntelMaxWorkGroupSizeAttr>(Attr))

clang/lib/Sema/SemaDeclAttr.cpp

@@ -10426,46 +10426,15 @@ static void handleFunctionReturnThunksAttr(Sema &S, Decl *D,
   D->addAttr(FunctionReturnThunksAttr::Create(S.Context, Kind, AL));
 }
 
-static constexpr std::pair<Decl::Kind, StringRef>
-MakeDeclContextDesc(Decl::Kind K, StringRef SR) {
-  return std::pair<Decl::Kind, StringRef>{K, SR};
-}
-
-// FIXME: Refactor Util class in SemaSYCL.cpp to avoid following
-// code duplication.
 bool isDeviceAspectType(const QualType Ty) {
   const EnumType *ET = Ty->getAs<EnumType>();
   if (!ET)
     return false;
 
-  std::array<std::pair<Decl::Kind, StringRef>, 3> Scopes = {
-      MakeDeclContextDesc(Decl::Kind::Namespace, "sycl"),
-      MakeDeclContextDesc(Decl::Kind::Namespace, "_V1"),
-      MakeDeclContextDesc(Decl::Kind::Enum, "aspect")};
-
-  const auto *Ctx = cast<DeclContext>(ET->getDecl());
-  StringRef Name = "";
-
-  for (const auto &Scope : llvm::reverse(Scopes)) {
-    Decl::Kind DK = Ctx->getDeclKind();
-    if (DK != Scope.first)
-      return false;
+  if (const auto *Attr = ET->getDecl()->getAttr<SYCLTypeAttr>())
+    return Attr->getType() == SYCLTypeAttr::aspect;
 
-    switch (DK) {
-    case Decl::Kind::Enum:
-      Name = cast<EnumDecl>(Ctx)->getName();
-      break;
-    case Decl::Kind::Namespace:
-      Name = cast<NamespaceDecl>(Ctx)->getName();
-      break;
-    default:
-      llvm_unreachable("isDeviceAspectType: decl kind not supported");
-    }
-    if (Name != Scope.second)
-      return false;
-    Ctx = Ctx->getParent();
-  }
-  return Ctx->isTranslationUnit();
+  return false;
 }
 
 SYCLDeviceHasAttr *Sema::MergeSYCLDeviceHasAttr(Decl *D,
@@ -10590,6 +10559,39 @@ static void handleSYCLKernelAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   handleSimpleAttribute<SYCLKernelAttr>(S, D, AL);
 }
 
+SYCLTypeAttr *Sema::MergeSYCLTypeAttr(Decl *D, const AttributeCommonInfo &CI,
+                                      SYCLTypeAttr::SYCLType TypeName) {
+  if (const auto *ExistingAttr = D->getAttr<SYCLTypeAttr>()) {
+    if (ExistingAttr->getType() != TypeName) {
+      Diag(ExistingAttr->getLoc(), diag::err_duplicate_attribute)
+          << ExistingAttr;
+      Diag(CI.getLoc(), diag::note_previous_attribute);
+    }
+    // Do not add duplicate attribute
+    return nullptr;
+  }
+  return ::new (Context) SYCLTypeAttr(Context, CI, TypeName);
+}
+
+static void handleSYCLTypeAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
+  if (!AL.isArgIdent(0)) {
+    S.Diag(AL.getLoc(), diag::err_attribute_argument_type)
+        << AL << AANT_ArgumentIdentifier;
+    return;
+  }
+
+  IdentifierInfo *II = AL.getArgAsIdent(0)->Ident;
+  SYCLTypeAttr::SYCLType Type;
+
+  if (!SYCLTypeAttr::ConvertStrToSYCLType(II->getName(), Type)) {
+    S.Diag(AL.getLoc(), diag::err_attribute_argument_not_supported) << AL << II;
+    return;
+  }
+
+  if (SYCLTypeAttr *NewAttr = S.MergeSYCLTypeAttr(D, AL, Type))
+    D->addAttr(NewAttr);
+}
+
 static void handleDestroyAttr(Sema &S, Decl *D, const ParsedAttr &A) {
   if (!cast<VarDecl>(D)->hasGlobalStorage()) {
     S.Diag(D->getLocation(), diag::err_destroy_attr_on_non_static_var)
@@ -11142,6 +11144,9 @@ ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, const ParsedAttr &AL,
   case ParsedAttr::AT_SYCLSpecialClass:
     handleSimpleAttribute<SYCLSpecialClassAttr>(S, D, AL);
     break;
+  case ParsedAttr::AT_SYCLType:
+    handleSYCLTypeAttr(S, D, AL);
+    break;
   case ParsedAttr::AT_SYCLDevice:
     handleSYCLDeviceAttr(S, D, AL);
     break;