[clang/AST] Make it possible to use SwiftAttr in type context

clang/include/clang/AST/ASTContext.h

@@ -1615,8 +1615,15 @@ class ASTContext : public RefCountedBase<ASTContext> {
   QualType getInjectedClassNameType(CXXRecordDecl *Decl, QualType TST) const;
 
   QualType getAttributedType(attr::Kind attrKind, QualType modifiedType,
+                             QualType equivalentType,
+                             const Attr *attr = nullptr) const;
+
+  QualType getAttributedType(const Attr *attr, QualType modifiedType,
                              QualType equivalentType) const;
 
+  QualType getAttributedType(NullabilityKind nullability, QualType modifiedType,
+                             QualType equivalentType);
+
   QualType getBTFTagAttributedType(const BTFTypeTagAttr *BTFAttr,
                                    QualType Wrapped);
 

clang/include/clang/AST/PropertiesBase.td

@@ -76,6 +76,7 @@ def APValue : PropertyType { let PassByReference = 1; }
 def APValueKind : EnumPropertyType<"APValue::ValueKind">;
 def ArraySizeModifier : EnumPropertyType<"ArrayType::ArraySizeModifier">;
 def AttrKind : EnumPropertyType<"attr::Kind">;
+def Attr : PropertyType<"const Attr *">;
 def AutoTypeKeyword : EnumPropertyType;
 def Bool : PropertyType<"bool">;
 def BuiltinTypeKind : EnumPropertyType<"BuiltinType::Kind">;

clang/include/clang/AST/Type.h

@@ -63,6 +63,7 @@ class ConceptDecl;
 class TagDecl;
 class TemplateParameterList;
 class Type;
+class Attr;
 
 enum {
   TypeAlignmentInBits = 4,
@@ -5073,13 +5074,24 @@ class AttributedType : public Type, public llvm::FoldingSetNode {
 private:
   friend class ASTContext; // ASTContext creates these
 
+  const Attr *Attribute;
+
   QualType ModifiedType;
   QualType EquivalentType;
 
   AttributedType(QualType canon, attr::Kind attrKind, QualType modified,
                  QualType equivalent)
+      : AttributedType(canon, attrKind, nullptr, modified, equivalent) {}
+
+  AttributedType(QualType canon, const Attr *attr, QualType modified,
+                 QualType equivalent);
+
+private:
+  AttributedType(QualType canon, attr::Kind attrKind, const Attr *attr,
+                 QualType modified, QualType equivalent)
       : Type(Attributed, canon, equivalent->getDependence()),
-        ModifiedType(modified), EquivalentType(equivalent) {
+        Attribute(attr), ModifiedType(modified),
+        EquivalentType(equivalent) {
     AttributedTypeBits.AttrKind = attrKind;
   }
 
@@ -5088,6 +5100,8 @@ class AttributedType : public Type, public llvm::FoldingSetNode {
     return static_cast<Kind>(AttributedTypeBits.AttrKind);
   }
 
+  const Attr *getAttr() const { return Attribute; }
+
   QualType getModifiedType() const { return ModifiedType; }
   QualType getEquivalentType() const { return EquivalentType; }
 
@@ -5119,25 +5133,6 @@ class AttributedType : public Type, public llvm::FoldingSetNode {
 
   std::optional<NullabilityKind> getImmediateNullability() const;
 
-  /// Retrieve the attribute kind corresponding to the given
-  /// nullability kind.
-  static Kind getNullabilityAttrKind(NullabilityKind kind) {
-    switch (kind) {
-    case NullabilityKind::NonNull:
-      return attr::TypeNonNull;
-
-    case NullabilityKind::Nullable:
-      return attr::TypeNullable;
-
-    case NullabilityKind::NullableResult:
-      return attr::TypeNullableResult;
-
-    case NullabilityKind::Unspecified:
-      return attr::TypeNullUnspecified;
-    }
-    llvm_unreachable("Unknown nullability kind.");
-  }
-
   /// Strip off the top-level nullability annotation on the given
   /// type, if it's there.
   ///

clang/include/clang/AST/TypeProperties.td

@@ -614,12 +614,16 @@ let Class = AttributedType in {
   def : Property<"equivalentType", QualType> {
     let Read = [{ node->getEquivalentType() }];
   }
-  def : Property<"attribute", AttrKind> {
+  def : Property<"attrKind", AttrKind> {
     let Read = [{ node->getAttrKind() }];
   }
+  def : Property<"attribute", Attr> {
+    let Read = [{ node->getAttr() }];
+  }
 
   def : Creator<[{
-    return ctx.getAttributedType(attribute, modifiedType, equivalentType);
+    return ctx.getAttributedType(attrKind, modifiedType,
+                                 equivalentType, attribute);
   }]>;
 }
 

clang/include/clang/Basic/Attr.td

@@ -2519,7 +2519,7 @@ def SwiftAsyncName : InheritableAttr {
   let Documentation = [SwiftAsyncNameDocs];
 }
 
-def SwiftAttr : InheritableAttr {
+def SwiftAttr : DeclOrTypeAttr {
   let Spellings = [GNU<"swift_attr">];
   let Args = [StringArgument<"Attribute">];
   let Documentation = [SwiftAttrDocs];

clang/include/clang/Basic/AttrDocs.td

@@ -4372,8 +4372,8 @@ def SwiftAttrDocs : Documentation {
   let Heading = "swift_attr";
   let Content = [{
 The ``swift_attr`` provides a Swift-specific annotation for the declaration
-to which the attribute appertains to. It can be used on any declaration
-in Clang. This kind of annotation is ignored by Clang as it doesn't have any
+or type to which the attribute appertains to. It can be used on any declaration
+or type in Clang. This kind of annotation is ignored by Clang as it doesn't have any
 semantic meaning in languages supported by Clang. The Swift compiler can
 interpret these annotations according to its own rules when importing C or
 Objective-C declarations.

clang/include/clang/Serialization/ASTRecordWriter.h

@@ -126,6 +126,8 @@ class ASTRecordWriter
     AddStmt(const_cast<Stmt*>(S));
   }
 
+  void writeAttr(const Attr *A) { AddAttr(A); }
+
   /// Write an BTFTypeTagAttr object.
   void writeBTFTypeTagAttr(const BTFTypeTagAttr *A) { AddAttr(A); }
 

clang/lib/AST/ASTContext.cpp

@@ -3147,11 +3147,13 @@ QualType ASTContext::getFunctionTypeWithExceptionSpec(
         MQT->getMacroIdentifier());
 
   // Might have a calling-convention attribute.
-  if (const auto *AT = dyn_cast<AttributedType>(Orig))
+  if (const auto *AT = dyn_cast<AttributedType>(Orig)) {
     return getAttributedType(
         AT->getAttrKind(),
         getFunctionTypeWithExceptionSpec(AT->getModifiedType(), ESI),
-        getFunctionTypeWithExceptionSpec(AT->getEquivalentType(), ESI));
+        getFunctionTypeWithExceptionSpec(AT->getEquivalentType(), ESI),
+        AT->getAttr());
+  }
 
   // Anything else must be a function type. Rebuild it with the new exception
   // specification.
@@ -4730,24 +4732,54 @@ QualType ASTContext::getUnresolvedUsingType(
 
 QualType ASTContext::getAttributedType(attr::Kind attrKind,
                                        QualType modifiedType,
-                                       QualType equivalentType) const {
+                                       QualType equivalentType,
+                                       const Attr *attr) const {
   llvm::FoldingSetNodeID id;
   AttributedType::Profile(id, attrKind, modifiedType, equivalentType);
 
   void *insertPos = nullptr;
   AttributedType *type = AttributedTypes.FindNodeOrInsertPos(id, insertPos);
   if (type) return QualType(type, 0);
 
+  assert(!attr || attr->getKind() == attrKind);
+
   QualType canon = getCanonicalType(equivalentType);
   type = new (*this, TypeAlignment)
-      AttributedType(canon, attrKind, modifiedType, equivalentType);
+      AttributedType(canon, attrKind, attr, modifiedType, equivalentType);
 
   Types.push_back(type);
   AttributedTypes.InsertNode(type, insertPos);
 
   return QualType(type, 0);
 }
 
+QualType ASTContext::getAttributedType(const Attr *attr, QualType modifiedType,
+                                       QualType equivalentType) const {
+  return getAttributedType(attr->getKind(), modifiedType, equivalentType, attr);
+}
+
+QualType ASTContext::getAttributedType(NullabilityKind nullability,
+                                       QualType modifiedType,
+                                       QualType equivalentType) {
+  switch (nullability) {
+  case NullabilityKind::NonNull:
+    return getAttributedType(attr::TypeNonNull, modifiedType, equivalentType);
+
+  case NullabilityKind::Nullable:
+    return getAttributedType(attr::TypeNullable, modifiedType, equivalentType);
+
+  case NullabilityKind::NullableResult:
+    return getAttributedType(attr::TypeNullableResult, modifiedType,
+                             equivalentType);
+
+  case NullabilityKind::Unspecified:
+    return getAttributedType(attr::TypeNullUnspecified, modifiedType,
+                             equivalentType);
+  }
+
+  llvm_unreachable("Unknown nullability kind");
+}
+
 QualType ASTContext::getBTFTagAttributedType(const BTFTypeTagAttr *BTFAttr,
                                              QualType Wrapped) {
   llvm::FoldingSetNodeID ID;
@@ -6916,8 +6948,8 @@ QualType ASTContext::getArrayDecayedType(QualType Ty) const {
 
   // int x[_Nullable] -> int * _Nullable
   if (auto Nullability = Ty->getNullability()) {
-    Result = const_cast<ASTContext *>(this)->getAttributedType(
-        AttributedType::getNullabilityAttrKind(*Nullability), Result, Result);
+    Result = const_cast<ASTContext *>(this)->getAttributedType(*Nullability,
+                                                               Result, Result);
   }
   return Result;
 }
@@ -12996,7 +13028,8 @@ static QualType getCommonSugarTypeNode(ASTContext &Ctx, const Type *X,
       return QualType();
     // FIXME: It's inefficient to have to unify the modified types.
     return Ctx.getAttributedType(Kind, Ctx.getCommonSugaredType(MX, MY),
-                                 Ctx.getQualifiedType(Underlying));
+                                 Ctx.getQualifiedType(Underlying),
+                                 AX->getAttr());
   }
   case Type::BTFTagAttributed: {
     const auto *BX = cast<BTFTagAttributedType>(X);

clang/lib/AST/ASTDiagnostic.cpp

@@ -85,8 +85,7 @@ QualType clang::desugarForDiagnostic(ASTContext &Context, QualType QT,
       QualType SugarRT = FT->getReturnType();
       QualType RT = desugarForDiagnostic(Context, SugarRT, DesugarReturn);
       if (auto nullability = AttributedType::stripOuterNullability(SugarRT)) {
-        RT = Context.getAttributedType(
-            AttributedType::getNullabilityAttrKind(*nullability), RT, RT);
+        RT = Context.getAttributedType(*nullability, RT, RT);
       }
 
       bool DesugarArgument = false;
@@ -97,8 +96,7 @@ QualType clang::desugarForDiagnostic(ASTContext &Context, QualType QT,
           QualType PT = desugarForDiagnostic(Context, SugarPT, DesugarArgument);
           if (auto nullability =
                   AttributedType::stripOuterNullability(SugarPT)) {
-            PT = Context.getAttributedType(
-                AttributedType::getNullabilityAttrKind(*nullability), PT, PT);
+            PT = Context.getAttributedType(*nullability, PT, PT);
           }
           Args.push_back(PT);
         }

clang/lib/AST/ASTImporter.cpp

@@ -1505,8 +1505,9 @@ ExpectedType ASTNodeImporter::VisitAttributedType(const AttributedType *T) {
   if (!ToEquivalentTypeOrErr)
     return ToEquivalentTypeOrErr.takeError();
 
-  return Importer.getToContext().getAttributedType(T->getAttrKind(),
-      *ToModifiedTypeOrErr, *ToEquivalentTypeOrErr);
+  return Importer.getToContext().getAttributedType(
+      T->getAttrKind(), *ToModifiedTypeOrErr, *ToEquivalentTypeOrErr,
+      T->getAttr());
 }
 
 ExpectedType ASTNodeImporter::VisitTemplateTypeParmType(

clang/lib/AST/Type.cpp

@@ -1159,8 +1159,8 @@ struct SimpleTransformVisitor : public TypeVisitor<Derived, QualType> {
           == T->getEquivalentType().getAsOpaquePtr())
       return QualType(T, 0);
 
-    return Ctx.getAttributedType(T->getAttrKind(), modifiedType,
-                                 equivalentType);
+    return Ctx.getAttributedType(T->getAttrKind(), modifiedType, equivalentType,
+                                 T->getAttr());
   }
 
   QualType VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
@@ -1458,7 +1458,8 @@ struct SubstObjCTypeArgsVisitor
 
     // Rebuild the attributed type.
     return Ctx.getAttributedType(newAttrType->getAttrKind(),
-                                 newAttrType->getModifiedType(), newEquivType);
+                                 newAttrType->getModifiedType(), newEquivType,
+                                 newAttrType->getAttr());
   }
 };
 
@@ -3755,6 +3756,10 @@ bool RecordType::hasConstFields() const {
   return false;
 }
 
+AttributedType::AttributedType(QualType canon, const Attr *attr,
+                               QualType modified, QualType equivalent)
+    : AttributedType(canon, attr->getKind(), attr, modified, equivalent) {}
+
 bool AttributedType::isQualifier() const {
   // FIXME: Generate this with TableGen.
   switch (getAttrKind()) {

clang/lib/AST/TypePrinter.cpp

@@ -1784,6 +1784,14 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
     return;
   }
 
+  if (T->getAttrKind() == attr::SwiftAttr) {
+    if (auto *swiftAttr = dyn_cast_or_null<SwiftAttrAttr>(T->getAttr())) {
+      OS << " __attribute__((swift_attr(\"" << swiftAttr->getAttribute()
+         << "\")))";
+    }
+    return;
+  }
+
   OS << " __attribute__((";
   switch (T->getAttrKind()) {
 #define TYPE_ATTR(NAME)
@@ -1826,6 +1834,7 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::AnnotateType:
   case attr::WebAssemblyFuncref:
   case attr::ArmStreaming:
+  case attr::SwiftAttr:
     llvm_unreachable("This attribute should have been handled already");
 
   case attr::NSReturnsRetained:

clang/lib/Sema/SemaDecl.cpp

@@ -3430,9 +3430,7 @@ static void mergeParamDeclTypes(ParmVarDecl *NewParam,
       }
     } else {
       QualType NewT = NewParam->getType();
-      NewT = S.Context.getAttributedType(
-                         AttributedType::getNullabilityAttrKind(*Oldnullability),
-                         NewT, NewT);
+      NewT = S.Context.getAttributedType(*Oldnullability, NewT, NewT);
       NewParam->setType(NewT);
     }
   }

clang/lib/Sema/SemaDeclAttr.cpp

@@ -6347,11 +6347,16 @@ static void handleObjCPreciseLifetimeAttr(Sema &S, Decl *D,
 }
 
 static void handleSwiftAttrAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
+  if (AL.isInvalid() || AL.isUsedAsTypeAttr())
+    return;
+
   // Make sure that there is a string literal as the annotation's single
   // argument.
   StringRef Str;
-  if (!S.checkStringLiteralArgumentAttr(AL, 0, Str))
+  if (!S.checkStringLiteralArgumentAttr(AL, 0, Str)) {
+    AL.setInvalid();
     return;
+  }
 
   D->addAttr(::new (S.Context) SwiftAttrAttr(S.Context, AL, Str));
 }

clang/lib/Sema/SemaDeclObjC.cpp

@@ -4623,9 +4623,7 @@ static QualType mergeTypeNullabilityForRedecl(Sema &S, SourceLocation loc,
     return type;
 
   // Otherwise, provide the result with the same nullability.
-  return S.Context.getAttributedType(
-           AttributedType::getNullabilityAttrKind(*prevNullability),
-           type, type);
+  return S.Context.getAttributedType(*prevNullability, type, type);
 }
 
 /// Merge information from the declaration of a method in the \@interface

clang/lib/Sema/SemaExpr.cpp

@@ -9593,8 +9593,7 @@ static QualType computeConditionalNullability(QualType ResTy, bool IsBin,
     ResTy = ResTy.getSingleStepDesugaredType(Ctx);
 
   // Create a new AttributedType with the new nullability kind.
-  auto NewAttr = AttributedType::getNullabilityAttrKind(MergedKind);
-  return Ctx.getAttributedType(NewAttr, ResTy, ResTy);
+  return Ctx.getAttributedType(MergedKind, ResTy, ResTy);
 }
 
 /// ActOnConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null