Model type attributes as regular Attrs

[rsmith]

Summary

Specifically, AttributedType now tracks a regular attr::Kind rather than having its own parallel Kind enumeration, and AttributedTypeLoc now holds an Attr* instead of holding an ad-hoc collection of fields mirroring those that would be present in the corresponding Attr subclass.

This aims to simplify and unify the modeling of attributes, both to make tooling simpler and to avoid code duplication for attributes that can be both type and declaration attributes.

[aaron.ballman]

Thank you for working on this -- the approach you've taken looks good, and I mostly have little nits here and there. I think this is a great refactoring overall though -- much needed!

include/clang/AST/Type.h

1856

Typo: MRC should be ARC (typo was present in the original code).

include/clang/Basic/Attr.td

1510

I don't suppose you can throw in some quick docs for this keyword? Or is this not really user-facing? If it's not user-facing, perhaps it should have no spellings and only ever be created implicitly?

lib/AST/Type.cpp

1624

const auto *

3215

Probably need to keep this to prevent MSVC from barking about not all control paths returning a value.

3652

Update the identifiers for coding standards since you're basically rewriting the function?

3652–3655

const auto *

lib/AST/TypeLoc.cpp

407–411

Might as well go with const Attr * here, the auto gets us nothing.

lib/Sema/SemaDecl.cpp

6024

const auto *

lib/Sema/SemaType.cpp

178–180

"We use the keep the attributes" isn't grammatical. Should it be, "We keep the attributes in creation order" instead?

181

It's unfortunate to use the name TypeAttr here -- unqualified uses of the type name, like below, makes it look like it might be the TypeAttr from Attr.h

3884

Did clang-format do this? It seems like it's not formatted how I'd expect.

6360

MSVC may complain about not all control paths returning a value here.

lib/Serialization/ASTReaderDecl.cpp

2695

This could use a comment to explain why the -1 is required. Also, do we have a preference for C-style vs static_cast here?

2709–2710

Identifiers don't meet coding style rules.

lib/Serialization/ASTWriter.cpp

4485–4486

llvm::for_each(Attrs, AddAttr); ?

[rsmith]

include/clang/Basic/Attr.td

1510

This isn't actually the primary representation of __unsafe_unretained, this is an internal placeholder for "the user wrote __unsafe_unretained but we're not in ARC mode so it's meaningless (hence "inert")". So I don't think this is where we should attach the documentation (the right place is the ObjCOwnership attribute, which is also currently Undocumented, sadly). I'll at least add a comment to the .td file to explain that.

lib/AST/Type.cpp

1624

Done, but...

The pointee type is deduced as const anyway, so the const doesn't give any extra type safety. So the only benefit would be to the reader, and I don't think a reader of this code would care whether *AT is mutable, so the const seems like a distraction to me (and hence the explicit const is a minor harm to readability rather than a minor improvement). I can see how a reader trained to think that absence-of-const implies that mutation is intended would find the explicit const clearer, but (for better or probably worse) that's not the style we generally use in Clang (for instance, I didn't mark the AK parameter as const, but there is no implication that I intend to modify it).

That said, I don't feel strongly about this, and I certainly have no objection to making the change here. If we generally want to move to a style where auto is always accompanied by an explicit const when const would be deduced (in much the same way that we already expect that auto be accompanied by an explicit * when a pointer type would be deduced), I'd be OK with that -- but we should discuss that somewhere more visible than this review thread and include it in our general coding guidelines.

3215

There's a default: case now, so that shouldn't be a problem. (Removing the exhaustive list is intended to be temporary; I'd like to move to generating this with TableGen sooner rather than later.)

lib/Sema/SemaType.cpp

178–180

Hah, oops, yes.

181

Good point. I went with TypeAttrPair here, and AttrsForTypes in the vector.

3884

How would you expect it? clang-format puts a space after the template keyword, unfortunately, and IIRC can't be configured to not do so. Though as a consequence, it looks like the space is now more common in clang code by a 2:1 ratio despite being "clearly wrong" ;-(

6360

I'm confident that this pattern is fine; we use it all over the place. MSVC knows that control flow cannot leave an llvm_unreachable(...).

lib/Serialization/ASTReaderDecl.cpp

2709–2710

Fixed. (This was pre-existing, but I changed everything else in the function.)

lib/Serialization/ASTWriter.cpp

4485–4486

AddAttr is a non-static member function, so that doesn't work; the closest we can get would be something like llvm::for_each(Attrs, [&](const Attr *A) { AddAttr(A); }); -- but that seems unnecessarily circumlocutory to me.

[aaron.ballman]

LGTM! Thank you for this fantastic work!

include/clang/Basic/Attr.td

1510

Ah, thank you for the explanation; I agree.

lib/AST/Type.cpp

1624

That said, I don't feel strongly about this, and I certainly have no objection to making the change here. If we generally want to move to a style where auto is always accompanied by an explicit const when const would be deduced (in much the same way that we already expect that auto be accompanied by an explicit * when a pointer type would be deduced), I'd be OK with that -- but we should discuss that somewhere more visible than this review thread and include it in our general coding guidelines.

Yeah, I actually thought this already was part of the coding guidelines, truth be told. But I went and looked again and realized we only talk about * and & being deduced, not qualifiers. I guess my preference has always been to explicitly spell out pertinent information about the type beyond the name, such as whether it's const, whether it's a pointer, etc. Basically, things that aren't immediately obvious from the context.

I prefer being explicit about spelling out the const here because it makes it obvious that the type is not intended to be mutated, but I only really care about it in cases where the type is deduced to a pointer or reference (and so mutating operations might be hidden behind a function call that looks harmless).

Perhaps this is worth starting a coding guideline discussion over?

lib/Sema/SemaType.cpp

3884

I was expecting to see a space after template as I thought that was the most common form of it in the code base. :-D

6360

Yeah, I think I was mis-remembering a pattern that caused warnings in MSVC here.

lib/Serialization/ASTWriter.cpp

4485–4486

Yeah, that's a bridge too far. The current form is preferable.

[rnk]

I suspect that somehow this change broke compiling ATL:
https://ci.chromium.org/buildbot/chromium.clang/ToTWin64%28dbg%29/993
https://logs.chromium.org/v/?s=chromium%2Fbb%2Fchromium.clang%2FToTWin64_dbg_%2F995%2F%2B%2Frecipes%2Fsteps%2Fcompile%2F0%2Flogs%2Fraw_io.output_failure_summary_%2F0

Now we get these diagnostics:

[1011/50166] CXX obj/chrome/chrome_cleaner/http/http/error_utils.obj
FAILED: obj/chrome/chrome_cleaner/http/http/error_utils.obj
...
In file included from ../../chrome/chrome_cleaner/http/error_utils.cc:11:
In file included from ../..\base/win/atl.h:18:
In file included from ..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlctl.h:33:
In file included from ..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlwin.h:5107:
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2777,9):  error: no matching function for call to 'AtlAxDialogCreateT'
return AtlAxDialogCreateT<LPCWSTR, _AtlDialogBoxIndirectParamHelper, ::DialogBoxIndirectParamW>(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2715,29):  note: candidate template ignored: invalid explicitly-specified argument for template parameter 'pFunc'
typename Helper::ReturnType AtlAxDialogCreateT(
^
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2788,9):  error: no matching function for call to 'AtlAxDialogCreateT'
return AtlAxDialogCreateT<LPCSTR, _AtlDialogBoxIndirectParamHelper, ::DialogBoxIndirectParamA>(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2715,29):  note: candidate template ignored: invalid explicitly-specified argument for template parameter 'pFunc'
typename Helper::ReturnType AtlAxDialogCreateT(
^
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2799,9):  error: no matching function for call to 'AtlAxDialogCreateT'
return AtlAxDialogCreateT<LPCWSTR, _AtlCreateDialogIndirectParamHelper, CreateDialogIndirectParamW>(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2715,29):  note: candidate template ignored: invalid explicitly-specified argument for template parameter 'pFunc'
typename Helper::ReturnType AtlAxDialogCreateT(
^
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2810,9):  error: no matching function for call to 'AtlAxDialogCreateT'
return AtlAxDialogCreateT<LPCSTR, _AtlCreateDialogIndirectParamHelper, CreateDialogIndirectParamA>(hInstance, lpTemplateName, hWndParent, lpDialogProc, dwInitParam);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..\..\third_party\depot_tools\win_toolchain\vs_files\3bc0ec615cf20ee342f3bc29bc991b5ad66d8d2c\VC\Tools\MSVC\14.14.26428\atlmfc\include\atlhost.h(2715,29):  note: candidate template ignored: invalid explicitly-specified argument for template parameter 'pFunc'
typename Helper::ReturnType AtlAxDialogCreateT(
^
4 errors generated.

[rnk]

I went ahead and reverted this in rC339638, and will produce a reduction soon.

[rnk]

The issue was related to ignored calling convention attributes on Win64:

int a(int, const int *, int, int, __int64);
class b {
public:
  typedef int c;
};
template <class d, class e,
          typename e::c(__stdcall f)(int, const int *, int, int, __int64)>
void AtlAxDialogCreateT(int, d, int, int, __int64);
int g, i, j, k;
char *h;
void l() { AtlAxDialogCreateT<char *, b, a>(g, h, i, j, k); }

Compiled with:
clang -c -fms-extensions -fms-compatibility --target=x86_64-windows-msvc

include/clang/AST/ASTContext.h

 #include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/AddressSpaces.h"
+#include "clang/Basic/AttrKinds.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/Linkage.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/SanitizerBlacklist.h"
 #include "clang/Basic/SourceLocation.h"
QualType getTypedefType(const TypedefNameDecl *Decl,
                           QualType Canon = QualType()) const;
 
   QualType getRecordType(const RecordDecl *Decl) const;
 
   QualType getEnumType(const EnumDecl *Decl) const;
 
   QualType getInjectedClassNameType(CXXRecordDecl *Decl, QualType TST) const;
 
-  QualType getAttributedType(AttributedType::Kind attrKind,
+  QualType getAttributedType(attr::Kind attrKind,
                              QualType modifiedType,
                              QualType equivalentType);
 
   QualType getSubstTemplateTypeParmType(const TemplateTypeParmType *Replaced,
                                         QualType Replacement) const;
   QualType getSubstTemplateTypeParmPackType(
                                           const TemplateTypeParmType *Replaced,
                                             const TemplateArgument &ArgPack);

include/clang/AST/Attr.h

public:
   Attr *clone(ASTContext &C) const;
 
   bool isLateParsed() const { return IsLateParsed; }
 
   // Pretty print this attribute.
   void printPretty(raw_ostream &OS, const PrintingPolicy &Policy) const;
 };
 
+class TypeAttr : public Attr {
+protected:
+  TypeAttr(attr::Kind AK, SourceRange R, unsigned SpellingListIndex,
+           bool IsLateParsed)
+      : Attr(AK, R, SpellingListIndex, IsLateParsed) {}
+
+public:
+  static bool classof(const Attr *A) {
+    return A->getKind() >= attr::FirstTypeAttr &&
+           A->getKind() <= attr::LastTypeAttr;
+  }
+};
+
 class StmtAttr : public Attr {
 protected:
   StmtAttr(attr::Kind AK, SourceRange R, unsigned SpellingListIndex,
                   bool IsLateParsed)
       : Attr(AK, R, SpellingListIndex, IsLateParsed) {}
 
 public:
   static bool classof(const Attr *A) {

include/clang/AST/Type.h

 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_AST_TYPE_H
 #define LLVM_CLANG_AST_TYPE_H
 
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/Basic/AddressSpaces.h"
+#include "clang/Basic/AttrKinds.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/ExceptionSpecificationType.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/Linkage.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/Visibility.h"
public:
   // FIXME: change this to 'raw' interface type, so we can used 'interface' type
   // for the common case.
   bool isObjCObjectType() const;                // NSString or typeof(*(id)0)
   bool isObjCQualifiedInterfaceType() const;    // NSString<foo>
   bool isObjCQualifiedIdType() const;           // id<foo>
   bool isObjCQualifiedClassType() const;        // Class<foo>
   bool isObjCObjectOrInterfaceType() const;
   bool isObjCIdType() const;                    // id
-  bool isObjCInertUnsafeUnretainedType() const;
+
+  /// Was this type written with the special inert-in-ARC __unsafe_unretained
+  /// qualifier?
+  ///
+  /// This approximates the answer to the following question: if this
+  /// translation unit were compiled in ARC, would this type be qualified
+  /// with __unsafe_unretained?
+  bool isObjCInertUnsafeUnretainedType() const {
+    return hasAttr(attr::ObjCInertUnsafeUnretained);
+  }
 
   /// Whether the type is Objective-C 'id' or a __kindof type of an
   /// object type, e.g., __kindof NSView * or __kindof id
   /// <NSCopying>.
   ///
   /// \param bound Will be set to the bound on non-id subtype types,
   /// which will be (possibly specialized) Objective-C class type, or
   /// null for 'id.
#include "clang/Basic/OpenCLImageTypes.def"
   /// to dyn_cast<T>; which is to say, the underlying type *must*
   /// have the intended type, and this method will never return null.
   template <typename T> const T *castAs() const;
 
   /// A variant of castAs<> for array type which silently discards
   /// qualifiers from the outermost type.
   const ArrayType *castAsArrayTypeUnsafe() const;
 
+  /// Determine whether this type had the specified attribute applied to it
+  /// (looking through top-level type sugar).
+  bool hasAttr(attr::Kind AK) const;
+
   /// Get the base element type of this type, potentially discarding type
   /// qualifiers.  This should never be used when type qualifiers
   /// are meaningful.
   const Type *getBaseElementTypeUnsafe() const;
 
   /// If this is an array type, return the element type of the array,
   /// potentially with type qualifiers missing.
   /// This should never be used when type qualifiers are meaningful.

 ///
 /// For example, in the following attributed type:
 ///     int32_t __attribute__((vector_size(16)))
 ///   - the modified type is the TypedefType for int32_t
 ///   - the equivalent type is VectorType(16, int32_t)
 ///   - the canonical type is VectorType(16, int)
 class AttributedType : public Type, public llvm::FoldingSetNode {
 public:
-  // It is really silly to have yet another attribute-kind enum, but
-  // clang::attr::Kind doesn't currently cover the pure type attrs.
-  enum Kind {
-    // Expression operand.
-    attr_address_space,
-    attr_regparm,
-    attr_vector_size,
-    attr_neon_vector_type,
-    attr_neon_polyvector_type,
-
-    FirstExprOperandKind = attr_address_space,
-    LastExprOperandKind = attr_neon_polyvector_type,
-
-    // Enumerated operand (string or keyword).
-    attr_objc_gc,
-    attr_objc_ownership,
-    attr_pcs,
-    attr_pcs_vfp,
-
-    FirstEnumOperandKind = attr_objc_gc,
-    LastEnumOperandKind = attr_pcs_vfp,
-
-    // No operand.
-    attr_noreturn,
-    attr_nocf_check,
-    attr_cdecl,
-    attr_fastcall,
-    attr_stdcall,
-    attr_thiscall,
-    attr_regcall,
-    attr_pascal,
-    attr_swiftcall,
-    attr_vectorcall,
-    attr_inteloclbicc,
-    attr_ms_abi,
-    attr_sysv_abi,
-    attr_preserve_most,
-    attr_preserve_all,
-    attr_ptr32,
-    attr_ptr64,
-    attr_sptr,
-    attr_uptr,
-    attr_nonnull,
-    attr_ns_returns_retained,
-    attr_nullable,
-    attr_null_unspecified,
-    attr_objc_kindof,
-    attr_objc_inert_unsafe_unretained,
-    attr_lifetimebound,
-  };
+  using Kind = attr::Kind;
 
 private:
   friend class ASTContext; // ASTContext creates these
 
   QualType ModifiedType;
   QualType EquivalentType;
 
-  AttributedType(QualType canon, Kind attrKind, QualType modified,
+  AttributedType(QualType canon, attr::Kind attrKind, QualType modified,
                  QualType equivalent)
       : Type(Attributed, canon, equivalent->isDependentType(),
              equivalent->isInstantiationDependentType(),
              equivalent->isVariablyModifiedType(),
              equivalent->containsUnexpandedParameterPack()),
         ModifiedType(modified), EquivalentType(equivalent) {
     AttributedTypeBits.AttrKind = attrKind;
   }
public:
 
   llvm::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_nonnull;
+      return attr::TypeNonNull;
 
     case NullabilityKind::Nullable:
-      return attr_nullable;
+      return attr::TypeNullable;
 
     case NullabilityKind::Unspecified:
-      return attr_null_unspecified;
+      return attr::TypeNullUnspecified;
     }
     llvm_unreachable("Unknown nullability kind.");
   }
 
   /// Strip off the top-level nullability annotation on the given
   /// type, if it's there.
   ///
   /// \param T The type to strip. If the type is exactly an

include/clang/AST/TypeLoc.h

 /// \file
 /// Defines the clang::TypeLoc interface and its subclasses.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_AST_TYPELOC_H
 #define LLVM_CLANG_AST_TYPELOC_H
 
+#include "clang/AST/Attr.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "llvm/ADT/ArrayRef.h"
class SubstTemplateTypeParmTypeLoc :
   /// Wrapper for substituted template type parameters.
 class SubstTemplateTypeParmPackTypeLoc :
     public InheritingConcreteTypeLoc<TypeSpecTypeLoc,
                                      SubstTemplateTypeParmPackTypeLoc,
                                      SubstTemplateTypeParmPackType> {
 };
 
 struct AttributedLocInfo {
-  union {
-    Expr *ExprOperand;
-
-    /// A raw SourceLocation.
-    unsigned EnumOperandLoc;
-  };
-
-  SourceRange OperandParens;
-
-  SourceLocation AttrLoc;
+  const Attr *TypeAttr;
 };
 
 /// Type source information for an attributed type.
 class AttributedTypeLoc : public ConcreteTypeLoc<UnqualTypeLoc,
                                                  AttributedTypeLoc,
                                                  AttributedType,
                                                  AttributedLocInfo> {
 public:
-  AttributedType::Kind getAttrKind() const {
+  attr::Kind getAttrKind() const {
     return getTypePtr()->getAttrKind();
   }
 
-  bool hasAttrExprOperand() const {
-    return (getAttrKind() >= AttributedType::FirstExprOperandKind &&
-            getAttrKind() <= AttributedType::LastExprOperandKind);
-  }
-
-  bool hasAttrEnumOperand() const {
-    return (getAttrKind() >= AttributedType::FirstEnumOperandKind &&
-            getAttrKind() <= AttributedType::LastEnumOperandKind);
-  }
-
-  bool hasAttrOperand() const {
-    return hasAttrExprOperand() || hasAttrEnumOperand();
-  }
-
   bool isQualifier() const {
     return getTypePtr()->isQualifier();
   }
 
   /// The modified type, which is generally canonically different from
   /// the attribute type.
   ///    int main(int, char**) __attribute__((noreturn))
   ///    ~~~     ~~~~~~~~~~~~~
   TypeLoc getModifiedLoc() const {
     return getInnerTypeLoc();
   }
 
-  /// The location of the attribute name, i.e.
-  ///    __attribute__((regparm(1000)))
-  ///                   ^~~~~~~
-  SourceLocation getAttrNameLoc() const {
-    return getLocalData()->AttrLoc;
-  }
-  void setAttrNameLoc(SourceLocation loc) {
-    getLocalData()->AttrLoc = loc;
-  }
-
-  /// The attribute's expression operand, if it has one.
-  ///    void *cur_thread __attribute__((address_space(21)))
-  ///                                                  ^~
-  Expr *getAttrExprOperand() const {
-    assert(hasAttrExprOperand());
-    return getLocalData()->ExprOperand;
+  /// The type attribute.
+  const Attr *getAttr() const {
+    return getLocalData()->TypeAttr;
   }
-  void setAttrExprOperand(Expr *e) {
-    assert(hasAttrExprOperand());
-    getLocalData()->ExprOperand = e;
+  void setAttr(const Attr *A) {
+    getLocalData()->TypeAttr = A;
   }
 
-  /// The location of the attribute's enumerated operand, if it has one.
-  ///    void * __attribute__((objc_gc(weak)))
-  ///                                  ^~~~
-  SourceLocation getAttrEnumOperandLoc() const {
-    assert(hasAttrEnumOperand());
-    return SourceLocation::getFromRawEncoding(getLocalData()->EnumOperandLoc);
-  }
-  void setAttrEnumOperandLoc(SourceLocation loc) {
-    assert(hasAttrEnumOperand());
-    getLocalData()->EnumOperandLoc = loc.getRawEncoding();
-  }
-
-  /// The location of the parentheses around the operand, if there is
-  /// an operand.
-  ///    void * __attribute__((objc_gc(weak)))
-  ///                                 ^    ^
-  SourceRange getAttrOperandParensRange() const {
-    assert(hasAttrOperand());
-    return getLocalData()->OperandParens;
-  }
-  void setAttrOperandParensRange(SourceRange range) {
-    assert(hasAttrOperand());
-    getLocalData()->OperandParens = range;
+  template<typename T> const T *getAttrAs() {
+    return dyn_cast_or_null<T>(getAttr());
   }
 
   SourceRange getLocalSourceRange() const {
     // Note that this does *not* include the range of the attribute
     // enclosure, e.g.:
     //    __attribute__((foo(bar)))
     //    ^~~~~~~~~~~~~~~        ~~
     // or
     //    [[foo(bar)]]
     //    ^~        ~~
     // That enclosure doesn't necessarily belong to a single attribute
     // anyway.
-    SourceRange range(getAttrNameLoc());
-    if (hasAttrOperand())
-      range.setEnd(getAttrOperandParensRange().getEnd());
-    return range;
+    return getAttr() ? getAttr()->getRange() : SourceRange();
   }
 
   void initializeLocal(ASTContext &Context, SourceLocation loc) {
-    setAttrNameLoc(loc);
-    if (hasAttrExprOperand()) {
-      setAttrOperandParensRange(SourceRange(loc));
-      setAttrExprOperand(nullptr);
-    } else if (hasAttrEnumOperand()) {
-      setAttrOperandParensRange(SourceRange(loc));
-      setAttrEnumOperandLoc(loc);
-    }
+    setAttr(nullptr);
   }
 
   QualType getInnerType() const {
     return getTypePtr()->getModifiedType();
   }
 };
 
 struct ObjCObjectTypeLocInfo {

include/clang/Basic/Attr.td

class Attr {
   code AdditionalMembers = [{}];
   // Any documentation that should be associated with the attribute. Since an
   // attribute may be documented under multiple categories, more than one
   // Documentation entry may be listed.
   list<Documentation> Documentation;
 }
 
 /// A type attribute is not processed on a declaration or a statement.
-class TypeAttr : Attr {
-  // By default, type attributes do not get an AST node.
-  let ASTNode = 0;
-}
+class TypeAttr : Attr;
 
 /// A stmt attribute is not processed on a declaration or a type.
 class StmtAttr : Attr;
 
 /// An inheritable attribute is inherited by later redeclarations.
 class InheritableAttr : Attr {
   // Set to true if this attribute can be duplicated on a subject when inheriting
   // attributes from prior declarations.
def AbiTag : Attr {
   let MeaningfulToClassTemplateDefinition = 1;
   let Documentation = [AbiTagsDocs];
 }
 
 def AddressSpace : TypeAttr {
   let Spellings = [Clang<"address_space">];
   let Args = [IntArgument<"AddressSpace">];
   let Documentation = [Undocumented];
+  // Represented as a qualifier or DependentAddressSpaceType instead.
+  let ASTNode = 0;
 }
 
 def Alias : Attr {
   let Spellings = [GCC<"alias">];
   let Args = [StringArgument<"Aliasee">];
   let Subjects = SubjectList<[Function, GlobalVar], ErrorDiag>;
   let Documentation = [Undocumented];
 }

 
 def LayoutVersion : InheritableAttr, TargetSpecificAttr<TargetMicrosoftCXXABI> {
   let Spellings = [Declspec<"layout_version">];
   let Args = [UnsignedArgument<"Version">];
   let Subjects = SubjectList<[CXXRecord]>;
   let Documentation = [LayoutVersionDocs];
 }
 
-def LifetimeBound : InheritableAttr {
+def LifetimeBound : DeclOrTypeAttr {
   let Spellings = [Clang<"lifetimebound", 0>];
   let Subjects = SubjectList<[ParmVar, ImplicitObjectParameter], ErrorDiag>;
   let Documentation = [LifetimeBoundDocs];
   let LangOpts = [CPlusPlus];
 }
 
 def TrivialABI : InheritableAttr {
   // This attribute does not have a C [[]] spelling because it requires the
def Naked : InheritableAttr {
   let Subjects = SubjectList<[Function]>;
   let Documentation = [Undocumented];
 }
 
 def NeonPolyVectorType : TypeAttr {
   let Spellings = [Clang<"neon_polyvector_type">];
   let Args = [IntArgument<"NumElements">];
   let Documentation = [Undocumented];
+  // Represented as VectorType instead.
+  let ASTNode = 0;
 }
 
 def NeonVectorType : TypeAttr {
   let Spellings = [Clang<"neon_vector_type">];
   let Args = [IntArgument<"NumElements">];
   let Documentation = [Undocumented];
+  // Represented as VectorType instead.
+  let ASTNode = 0;
 }
 
 def ReturnsTwice : InheritableAttr {
   let Spellings = [GCC<"returns_twice">];
   let Subjects = SubjectList<[Function]>;
   let Documentation = [Undocumented];
 }
 
def TypeNullable : TypeAttr {
   let Documentation = [TypeNullableDocs];
 }
 
 def TypeNullUnspecified : TypeAttr {
   let Spellings = [Keyword<"_Null_unspecified">];
   let Documentation = [TypeNullUnspecifiedDocs];
 }
 
+// This is a marker used to indicate that an __unsafe_unretained qualifier was
+// ignored because ARC is not enabled. The usual representation for this
+// qualifier is as an ObjCOwnership attribute with Kind == "none".
+def ObjCInertUnsafeUnretained : TypeAttr {
+  let Spellings = [Keyword<"__unsafe_unretained">];
+  let Documentation = [Undocumented];
+}
+
 def ObjCKindOf : TypeAttr {
   let Spellings = [Keyword<"__kindof">];
   let Documentation = [Undocumented];
 }
 
 def NoEscape : Attr {
   let Spellings = [Clang<"noescape">];
   let Subjects = SubjectList<[ParmVar]>;
def ObjCBridgeRelated : InheritableAttr {
   let Subjects = SubjectList<[Record], ErrorDiag>;
   let Args = [IdentifierArgument<"RelatedClass">,
           IdentifierArgument<"ClassMethod">,
           IdentifierArgument<"InstanceMethod">];
   let HasCustomParsing = 1;
   let Documentation = [Undocumented];
 }
 
-def NSReturnsRetained : InheritableAttr {
+def NSReturnsRetained : DeclOrTypeAttr {
   let Spellings = [Clang<"ns_returns_retained">];
 //  let Subjects = SubjectList<[ObjCMethod, ObjCProperty, Function]>;
   let Documentation = [Undocumented];
 }
 
 def NSReturnsNotRetained : InheritableAttr {
   let Spellings = [Clang<"ns_returns_not_retained">];
 //  let Subjects = SubjectList<[ObjCMethod, ObjCProperty, Function]>;
def Pure : InheritableAttr {
   let Spellings = [GCC<"pure">];
   let Documentation = [Undocumented];
 }
 
 def Regparm : TypeAttr {
   let Spellings = [GCC<"regparm">];
   let Args = [UnsignedArgument<"NumParams">];
   let Documentation = [RegparmDocs];
+  // Represented as part of the enclosing function type.
+  let ASTNode = 0;
 }
 
 def ReqdWorkGroupSize : InheritableAttr {
   // Does not have a [[]] spelling because it is an OpenCL-related attribute.
   let Spellings = [GNU<"reqd_work_group_size">];
   let Args = [UnsignedArgument<"XDim">, UnsignedArgument<"YDim">,
               UnsignedArgument<"ZDim">];
   let Subjects = SubjectList<[Function], ErrorDiag>;

 }
 
 def ObjCGC : TypeAttr {
   let Spellings = [Clang<"objc_gc">];
   let Args = [IdentifierArgument<"Kind">];
   let Documentation = [Undocumented];
 }
 
-def ObjCOwnership : InheritableAttr {
+def ObjCOwnership : DeclOrTypeAttr {
   let Spellings = [Clang<"objc_ownership">];
   let Args = [IdentifierArgument<"Kind">];
-  let ASTNode = 0;
   let Documentation = [Undocumented];
 }
 
 def ObjCRequiresPropertyDefs : InheritableAttr {
   let Spellings = [Clang<"objc_requires_property_definitions">];
   let Subjects = SubjectList<[ObjCInterface], ErrorDiag>;
   let Documentation = [Undocumented];
 }
def Uuid : InheritableAttr {
   let LangOpts = [MicrosoftExt, Borland];
   let Documentation = [Undocumented];
 }
 
 def VectorSize : TypeAttr {
   let Spellings = [GCC<"vector_size">];
   let Args = [ExprArgument<"NumBytes">];
   let Documentation = [Undocumented];
+  // Represented as VectorType instead.
+  let ASTNode = 0;
 }
 
 def VecTypeHint : InheritableAttr {
   // Does not have a [[]] spelling because it is an OpenCL-related attribute.
   let Spellings = [GNU<"vec_type_hint">];
   let Args = [TypeArgument<"TypeHint">];
   let Subjects = SubjectList<[Function], ErrorDiag>;
   let Documentation = [Undocumented];

 }
 
 def AnyX86NoCallerSavedRegisters : InheritableAttr,
                                    TargetSpecificAttr<TargetAnyX86> {
   let Spellings = [GCC<"no_caller_saved_registers">];
   let Documentation = [AnyX86NoCallerSavedRegistersDocs];
 }
 
-def AnyX86NoCfCheck : InheritableAttr, TargetSpecificAttr<TargetAnyX86>{
+def AnyX86NoCfCheck : DeclOrTypeAttr, TargetSpecificAttr<TargetAnyX86>{
   let Spellings = [GCC<"nocf_check">];
   let Subjects = SubjectList<[FunctionLike]>;
   let Documentation = [AnyX86NoCfCheckDocs];
 }
 
 def X86ForceAlignArgPointer : InheritableAttr, TargetSpecificAttr<TargetAnyX86> {
   let Spellings = [GCC<"force_align_arg_pointer">];
   // Technically, this appertains to a FunctionDecl, but the target-specific

include/clang/Sema/Sema.h

public:
   QualType BuildAtomicType(QualType T, SourceLocation Loc);
   QualType BuildReadPipeType(QualType T,
                          SourceLocation Loc);
   QualType BuildWritePipeType(QualType T,
                          SourceLocation Loc);
 
   TypeSourceInfo *GetTypeForDeclarator(Declarator &D, Scope *S);
   TypeSourceInfo *GetTypeForDeclaratorCast(Declarator &D, QualType FromTy);
-  TypeSourceInfo *GetTypeSourceInfoForDeclarator(Declarator &D, QualType T,
-                                               TypeSourceInfo *ReturnTypeInfo);
 
   /// Package the given type and TSI into a ParsedType.
   ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo);
   DeclarationNameInfo GetNameForDeclarator(Declarator &D);
   DeclarationNameInfo GetNameFromUnqualifiedId(const UnqualifiedId &Name);
   static QualType GetTypeFromParser(ParsedType Ty,
                                     TypeSourceInfo **TInfo = nullptr);
   CanThrowResult canThrow(const Expr *E);
public:
   // The intent is to look for an attribute on the current declarator, but not
   // one that came from a typedef.
   bool hasExplicitCallingConv(QualType &T);
 
   /// Get the outermost AttributedType node that sets a calling convention.
   /// Valid types should not have multiple attributes with different CCs.
   const AttributedType *getCallingConvAttributedType(QualType T) const;
 
-  /// Check whether a nullability type specifier can be added to the given
-  /// type.
-  ///
-  /// \param type The type to which the nullability specifier will be
-  /// added. On success, this type will be updated appropriately.
-  ///
-  /// \param nullability The nullability specifier to add.
-  ///
-  /// \param nullabilityLoc The location of the nullability specifier.
-  ///
-  /// \param isContextSensitive Whether this nullability specifier was
-  /// written as a context-sensitive keyword (in an Objective-C
-  /// method) or an Objective-C property attribute, rather than as an
-  /// underscored type specifier.
-  ///
-  /// \param allowArrayTypes Whether to accept nullability specifiers on an
-  /// array type (e.g., because it will decay to a pointer).
-  ///
-  /// \returns true if nullability cannot be applied, false otherwise.
-  bool checkNullabilityTypeSpecifier(QualType &type, NullabilityKind nullability,
-                                     SourceLocation nullabilityLoc,
-                                     bool isContextSensitive,
-                                     bool allowArrayTypes);
-
   /// Stmt attributes - this routine is the top level dispatcher.
   StmtResult ProcessStmtAttributes(Stmt *Stmt,
                                    const ParsedAttributesView &Attrs,
                                    SourceRange Range);
 
   void WarnConflictingTypedMethods(ObjCMethodDecl *Method,
                                    ObjCMethodDecl *MethodDecl,
                                    bool IsProtocolMethodDecl);
QualType BuildObjCObjectType(QualType BaseType,
                                ArrayRef<TypeSourceInfo *> TypeArgs,
                                SourceLocation TypeArgsRAngleLoc,
                                SourceLocation ProtocolLAngleLoc,
                                ArrayRef<ObjCProtocolDecl *> Protocols,
                                ArrayRef<SourceLocation> ProtocolLocs,
                                SourceLocation ProtocolRAngleLoc,
                                bool FailOnError = false);
 
-  /// Check the application of the Objective-C '__kindof' qualifier to
-  /// the given type.
-  bool checkObjCKindOfType(QualType &type, SourceLocation loc);
-
   /// Ensure attributes are consistent with type.
   /// \param [in, out] Attributes The attributes to check; they will
   /// be modified to be consistent with \p PropertyTy.
   void CheckObjCPropertyAttributes(Decl *PropertyPtrTy,
                                    SourceLocation Loc,
                                    unsigned &Attributes,
                                    bool propertyInPrimaryClass);
 

include/clang/Serialization/ASTReader.h

public:
   }
 
   /// Read a version tuple.
   static VersionTuple ReadVersionTuple(const RecordData &Record, unsigned &Idx);
 
   CXXTemporary *ReadCXXTemporary(ModuleFile &F, const RecordData &Record,
                                  unsigned &Idx);
 
+  /// Reads one attribute from the current stream position.
+  Attr *ReadAttr(ModuleFile &M, const RecordData &Record, unsigned &Idx);
+
   /// Reads attributes from the current stream position.
   void ReadAttributes(ASTRecordReader &Record, AttrVec &Attrs);
 
   /// Reads a statement.
   Stmt *ReadStmt(ModuleFile &F);
 
   /// Reads an expression.
   Expr *ReadExpr(ModuleFile &F);
std::string readPath() {
     return Reader->ReadPath(*F, Record, Idx);
   }
 
   /// Read a version tuple, advancing Idx.
   VersionTuple readVersionTuple() {
     return ASTReader::ReadVersionTuple(Record, Idx);
   }
 
+  /// Reads one attribute from the current stream position, advancing Idx.
+  Attr *readAttr() {
+    return Reader->ReadAttr(*F, Record, Idx);
+  }
+
   /// Reads attributes from the current stream position, advancing Idx.
   void readAttributes(AttrVec &Attrs) {
     return Reader->ReadAttributes(*this, Attrs);
   }
 
   /// Reads a token out of a record, advancing Idx.
   Token readToken() {
     return Reader->ReadToken(*F, Record, Idx);

include/clang/Serialization/ASTWriter.h

void AddPath(StringRef Path) {
     return Writer->AddPath(Path, *Record);
   }
 
   /// Emit a version tuple.
   void AddVersionTuple(const VersionTuple &Version) {
     return Writer->AddVersionTuple(Version, *Record);
   }
 
+  // Emit an attribute.
+  void AddAttr(const Attr *A);
+
   /// Emit a list of attributes.
   void AddAttributes(ArrayRef<const Attr*> Attrs);
 };
 
 /// AST and semantic-analysis consumer that generates a
 /// precompiled header from the parsed source code.
 class PCHGenerator : public SemaConsumer {
   const Preprocessor &PP;

lib/ARCMigrate/TransGCAttrs.cpp

while (TL) {
       } else if (ReferenceTypeLoc RT = TL.getAs<ReferenceTypeLoc>())
         TL = RT.getPointeeLoc();
       else
         break;
     }
   }
 
   bool handleAttr(AttributedTypeLoc TL, Decl *D = nullptr) {
-    if (TL.getAttrKind() != AttributedType::attr_objc_ownership)
+    auto *OwnershipAttr = TL.getAttrAs<ObjCOwnershipAttr>();
+    if (!OwnershipAttr)
       return false;
 
-    SourceLocation Loc = TL.getAttrNameLoc();
+    SourceLocation Loc = OwnershipAttr->getLocation();
     unsigned RawLoc = Loc.getRawEncoding();
     if (MigrateCtx.AttrSet.count(RawLoc))
       return true;
 
     ASTContext &Ctx = MigrateCtx.Pass.Ctx;
     SourceManager &SM = Ctx.getSourceManager();
     if (Loc.isMacroID())
       Loc = SM.getImmediateExpansionRange(Loc).getBegin();
-    SmallString<32> Buf;
-    bool Invalid = false;
-    StringRef Spell = Lexer::getSpelling(
-                                  SM.getSpellingLoc(TL.getAttrEnumOperandLoc()),
-                                  Buf, SM, Ctx.getLangOpts(), &Invalid);
-    if (Invalid)
-      return false;
+    StringRef Spell = OwnershipAttr->getKind()->getName();
     MigrationContext::GCAttrOccurrence::AttrKind Kind;
     if (Spell == "strong")
       Kind = MigrationContext::GCAttrOccurrence::Strong;
     else if (Spell == "weak")
       Kind = MigrationContext::GCAttrOccurrence::Weak;
     else
       return false;
 
if (GCAttrsCollector::hasObjCImpl(
     }
     if (Attrs & ObjCPropertyDecl::OBJC_PR_assign)
       MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
     else
       MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
   }
 
   for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
-    SourceLocation Loc = ATLs[i].first.getAttrNameLoc();
+    SourceLocation Loc = ATLs[i].first.getAttr()->getLocation();
     if (Loc.isMacroID())
       Loc = MigrateCtx.Pass.Ctx.getSourceManager()
                 .getImmediateExpansionRange(Loc)
                 .getBegin();
     TA.remove(Loc);
     TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
     TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
                        ATLs[i].second->getLocation());

lib/ARCMigrate/Transforms.cpp

MigrationContext::~MigrationContext() {
   for (traverser_iterator
          I = traversers_begin(), E = traversers_end(); I != E; ++I)
     delete *I;
 }
 
 bool MigrationContext::isGCOwnedNonObjC(QualType T) {
   while (!T.isNull()) {
     if (const AttributedType *AttrT = T->getAs<AttributedType>()) {
-      if (AttrT->getAttrKind() == AttributedType::attr_objc_ownership)
+      if (AttrT->getAttrKind() == attr::ObjCOwnership)
         return !AttrT->getModifiedType()->isObjCRetainableType();
     }
 
     if (T->isArrayType())
       T = Pass.Ctx.getBaseElementType(T);
     else if (const PointerType *PT = T->getAs<PointerType>())
       T = PT->getPointeeType();
     else if (const ReferenceType *RT = T->getAs<ReferenceType>())

lib/AST/ASTContext.cpp

if (PrevDecl->TypeForDecl)
       return QualType(Decl->TypeForDecl = PrevDecl->TypeForDecl, 0);
 
   auto *newType = new (*this, TypeAlignment) EnumType(Decl);
   Decl->TypeForDecl = newType;
   Types.push_back(newType);
   return QualType(newType, 0);
 }
 
-QualType ASTContext::getAttributedType(AttributedType::Kind attrKind,
+QualType ASTContext::getAttributedType(attr::Kind attrKind,
                                        QualType modifiedType,
                                        QualType equivalentType) {
   llvm::FoldingSetNodeID id;
   AttributedType::Profile(id, attrKind, modifiedType, equivalentType);
 
   void *insertPos = nullptr;
   AttributedType *type = AttributedTypes.FindNodeOrInsertPos(id, insertPos);
   if (type) return QualType(type, 0);

lib/AST/Type.cpp

bool Type::isObjCClassOrClassKindOfType() const {
   // If it's not a __kindof type, reject it now.
   if (!OPT->isKindOfType())
     return false;
 
   // If it's Class or qualified Class, it's a class __kindof type.
   return OPT->isObjCClassType() || OPT->isObjCQualifiedClassType();
 }
 
-/// Was this type written with the special inert-in-MRC __unsafe_unretained
-/// qualifier?
-///
-/// This approximates the answer to the following question: if this
-/// translation unit were compiled in ARC, would this type be qualified
-/// with __unsafe_unretained?
-bool Type::isObjCInertUnsafeUnretainedType() const {
-  const Type *cur = this;
-  while (true) {
-    if (const auto attributed = dyn_cast<AttributedType>(cur)) {
-      if (attributed->getAttrKind() ==
-            AttributedType::attr_objc_inert_unsafe_unretained)
-        return true;
-    }
-
-    // Single-step desugar until we run out of sugar.
-    QualType next = cur->getLocallyUnqualifiedSingleStepDesugaredType();
-    if (next.getTypePtr() == cur) return false;
-    cur = next.getTypePtr();
-  }
-}
-
 ObjCTypeParamType::ObjCTypeParamType(const ObjCTypeParamDecl *D,
                                      QualType can,
                                      ArrayRef<ObjCProtocolDecl *> protocols)
     : Type(ObjCTypeParam, can, can->isDependentType(),
            can->isInstantiationDependentType(),
            can->isVariablyModifiedType(),
            /*ContainsUnexpandedParameterPack=*/false),
       OTPDecl(const_cast<ObjCTypeParamDecl*>(D)) {
TagDecl *Type::getAsTagDecl() const {
   if (const auto *TT = getAs<TagType>())
     return TT->getDecl();
   if (const auto *Injected = getAs<InjectedClassNameType>())
     return Injected->getDecl();
 
   return nullptr;
 }
 
+bool Type::hasAttr(attr::Kind AK) const {
+  const Type *Cur = this;
+  while (const auto *AT = Cur->getAs<AttributedType>()) {
+    if (AT->getAttrKind() == AK)
+      return true;
+    Cur = AT->getEquivalentType().getTypePtr();
+  }
+  return false;
+}
+
 namespace {
 
   class GetContainedDeducedTypeVisitor :
     public TypeVisitor<GetContainedDeducedTypeVisitor, Type*> {
     bool Syntactic;
 
   public:
     GetContainedDeducedTypeVisitor(bool Syntactic = false)
for (FieldDecl *FD : getDecl()->fields()) {
     if (const auto *FieldRecTy = FieldTy->getAs<RecordType>())
       if (FieldRecTy->hasConstFields())
         return true;
   }
   return false;
 }
 
 bool AttributedType::isQualifier() const {
+  // FIXME: Generate this with TableGen.
   switch (getAttrKind()) {
   // These are type qualifiers in the traditional C sense: they annotate
   // something about a specific value/variable of a type.  (They aren't
   // always part of the canonical type, though.)
-  case AttributedType::attr_address_space:
-  case AttributedType::attr_objc_gc:
-  case AttributedType::attr_objc_ownership:
-  case AttributedType::attr_objc_inert_unsafe_unretained:
-  case AttributedType::attr_nonnull:
-  case AttributedType::attr_nullable:
-  case AttributedType::attr_null_unspecified:
-  case AttributedType::attr_lifetimebound:
-    return true;
-
-  // These aren't qualifiers; they rewrite the modified type to be a
-  // semantically different type.
-  case AttributedType::attr_regparm:
-  case AttributedType::attr_vector_size:
-  case AttributedType::attr_neon_vector_type:
-  case AttributedType::attr_neon_polyvector_type:
-  case AttributedType::attr_pcs:
-  case AttributedType::attr_pcs_vfp:
-  case AttributedType::attr_noreturn:
-  case AttributedType::attr_cdecl:
-  case AttributedType::attr_fastcall:
-  case AttributedType::attr_stdcall:
-  case AttributedType::attr_thiscall:
-  case AttributedType::attr_regcall:
-  case AttributedType::attr_pascal:
-  case AttributedType::attr_swiftcall:
-  case AttributedType::attr_vectorcall:
-  case AttributedType::attr_inteloclbicc:
-  case AttributedType::attr_preserve_most:
-  case AttributedType::attr_preserve_all:
-  case AttributedType::attr_ms_abi:
-  case AttributedType::attr_sysv_abi:
-  case AttributedType::attr_ptr32:
-  case AttributedType::attr_ptr64:
-  case AttributedType::attr_sptr:
-  case AttributedType::attr_uptr:
-  case AttributedType::attr_objc_kindof:
-  case AttributedType::attr_ns_returns_retained:
-  case AttributedType::attr_nocf_check:
+  case attr::ObjCGC:
+  case attr::ObjCOwnership:
+  case attr::ObjCInertUnsafeUnretained:
+  case attr::TypeNonNull:
+  case attr::TypeNullable:
+  case attr::TypeNullUnspecified:
+  case attr::LifetimeBound:
+    return true;
+
+  // All other type attributes aren't qualifiers; they rewrite the modified
+  // type to be a semantically different type.
+  default:
     return false;
   }
-  llvm_unreachable("bad attributed type kind");
 }
 
 bool AttributedType::isMSTypeSpec() const {
+  // FIXME: Generate this with TableGen?
   switch (getAttrKind()) {
-  default:  return false;
-  case attr_ptr32:
-  case attr_ptr64:
-  case attr_sptr:
-  case attr_uptr:
+  default: return false;
+  case attr::Ptr32:
+  case attr::Ptr64:
+  case attr::SPtr:
+  case attr::UPtr:
     return true;
   }
   llvm_unreachable("invalid attr kind");
 }
 
 bool AttributedType::isCallingConv() const {
+  // FIXME: Generate this with TableGen.
   switch (getAttrKind()) {
-  case attr_ptr32:
-  case attr_ptr64:
-  case attr_sptr:
-  case attr_uptr:
-  case attr_address_space:
-  case attr_regparm:
-  case attr_vector_size:
-  case attr_neon_vector_type:
-  case attr_neon_polyvector_type:
-  case attr_objc_gc:
-  case attr_objc_ownership:
-  case attr_objc_inert_unsafe_unretained:
-  case attr_noreturn:
-  case attr_nonnull:
-  case attr_ns_returns_retained:
-  case attr_nullable:
-  case attr_null_unspecified:
-  case attr_objc_kindof:
-  case attr_nocf_check:
-  case attr_lifetimebound:
-    return false;
-
-  case attr_pcs:
-  case attr_pcs_vfp:
-  case attr_cdecl:
-  case attr_fastcall:
-  case attr_stdcall:
-  case attr_thiscall:
-  case attr_regcall:
-  case attr_swiftcall:
-  case attr_vectorcall:
-  case attr_pascal:
-  case attr_ms_abi:
-  case attr_sysv_abi:
-  case attr_inteloclbicc:
-  case attr_preserve_most:
-  case attr_preserve_all:
+  default: return false;
+  case attr::Pcs:
+  case attr::CDecl:
+  case attr::FastCall:
+  case attr::StdCall:
+  case attr::ThisCall:
+  case attr::RegCall:
+  case attr::SwiftCall:
+  case attr::VectorCall:
+  case attr::Pascal:
+  case attr::MSABI:
+  case attr::SysVABI:
+  case attr::IntelOclBicc:
+  case attr::PreserveMost:
+  case attr::PreserveAll:
     return true;
   }
   llvm_unreachable("invalid attr kind");
 }
 
 CXXRecordDecl *InjectedClassNameType::getDecl() const {
   return cast<CXXRecordDecl>(getInterestingTagDecl(Decl));
 }
LinkageInfo LinkageComputer::getTypeLinkageAndVisibility(const Type *T) {
   assert(LV.getLinkage() == T->getLinkage());
   return LV;
 }
 
 LinkageInfo Type::getLinkageAndVisibility() const {
   return LinkageComputer{}.getTypeLinkageAndVisibility(this);
 }
 
-Optional<NullabilityKind> Type::getNullability(const ASTContext &context) const {
-  QualType type(this, 0);
-  do {
+Optional<NullabilityKind>
+Type::getNullability(const ASTContext &Context) const {
+  QualType Type(this, 0);
+  while (const auto *AT = Type->getAs<AttributedType>()) {
     // Check whether this is an attributed type with nullability
     // information.
-    if (auto attributed = dyn_cast<AttributedType>(type.getTypePtr())) {
-      if (auto nullability = attributed->getImmediateNullability())
-        return nullability;
-    }
+    if (auto Nullability = AT->getImmediateNullability())
+      return Nullability;
 
-    // Desugar the type. If desugaring does nothing, we're done.
-    QualType desugared = type.getSingleStepDesugaredType(context);
-    if (desugared.getTypePtr() == type.getTypePtr())
-      return None;
-
-    type = desugared;
-  } while (true);
+    Type = AT->getEquivalentType();
+  }
 }
 
 bool Type::canHaveNullability(bool ResultIfUnknown) const {
   QualType type = getCanonicalTypeInternal();
 
   switch (type->getTypeClass()) {
   // We'll only see canonical types here.
 #define NON_CANONICAL_TYPE(Class, Parent)       \
#include "clang/Basic/OpenCLImageTypes.def"
   case Type::ObjCInterface:
   case Type::Atomic:
   case Type::Pipe:
     return false;
   }
   llvm_unreachable("bad type kind!");
 }
 
-llvm::Optional<NullabilityKind> AttributedType::getImmediateNullability() const {
-  if (getAttrKind() == AttributedType::attr_nonnull)
+llvm::Optional<NullabilityKind>
+AttributedType::getImmediateNullability() const {
+  if (getAttrKind() == attr::TypeNonNull)
     return NullabilityKind::NonNull;
-  if (getAttrKind() == AttributedType::attr_nullable)
+  if (getAttrKind() == attr::TypeNullable)
     return NullabilityKind::Nullable;
-  if (getAttrKind() == AttributedType::attr_null_unspecified)
+  if (getAttrKind() == attr::TypeNullUnspecified)
     return NullabilityKind::Unspecified;
   return None;
 }
 
 Optional<NullabilityKind> AttributedType::stripOuterNullability(QualType &T) {
   if (auto attributed = dyn_cast<AttributedType>(T.getTypePtr())) {
     if (auto nullability = attributed->getImmediateNullability()) {
       T = attributed->getModifiedType();

lib/AST/TypeLoc.cpp

 
 TypeLoc TypeLoc::IgnoreParensImpl(TypeLoc TL) {
   while (ParenTypeLoc PTL = TL.getAs<ParenTypeLoc>())
     TL = PTL.getInnerLoc();
   return TL;
 }
 
 SourceLocation TypeLoc::findNullabilityLoc() const {
-  if (auto attributedLoc = getAs<AttributedTypeLoc>()) {
-    if (attributedLoc.getAttrKind() == AttributedType::attr_nullable ||
-        attributedLoc.getAttrKind() == AttributedType::attr_nonnull ||
-        attributedLoc.getAttrKind() == AttributedType::attr_null_unspecified)
-      return attributedLoc.getAttrNameLoc();
+  if (auto ATL = getAs<AttributedTypeLoc>()) {
+    const Attr *A = ATL.getAttr();
+    if (A && (isa<TypeNullableAttr>(A) || isa<TypeNonNullAttr>(A) ||
+              isa<TypeNullUnspecifiedAttr>(A)))
+      return A->getLocation();
   }
 
   return {};
 }
 
 TypeLoc TypeLoc::findExplicitQualifierLoc() const {
   // Qualified types.
   if (auto qual = getAs<QualifiedTypeLoc>())

lib/AST/TypePrinter.cpp

 void TypePrinter::printPackExpansionAfter(const PackExpansionType *T,
                                           raw_ostream &OS) {
   printAfter(T->getPattern(), OS);
   OS << "...";
 }
 
 void TypePrinter::printAttributedBefore(const AttributedType *T,
                                         raw_ostream &OS) {
+  // FIXME: Generate this with TableGen.
+
   // Prefer the macro forms of the GC and ownership qualifiers.
-  if (T->getAttrKind() == AttributedType::attr_objc_gc ||
-      T->getAttrKind() == AttributedType::attr_objc_ownership)
+  if (T->getAttrKind() == attr::ObjCGC ||
+      T->getAttrKind() == attr::ObjCOwnership)
     return printBefore(T->getEquivalentType(), OS);
 
-  if (T->getAttrKind() == AttributedType::attr_objc_kindof)
+  if (T->getAttrKind() == attr::ObjCKindOf)
     OS << "__kindof ";
 
   printBefore(T->getModifiedType(), OS);
 
   if (T->isMSTypeSpec()) {
     switch (T->getAttrKind()) {
     default: return;
-    case AttributedType::attr_ptr32: OS << " __ptr32"; break;
-    case AttributedType::attr_ptr64: OS << " __ptr64"; break;
-    case AttributedType::attr_sptr: OS << " __sptr"; break;
-    case AttributedType::attr_uptr: OS << " __uptr"; break;
+    case attr::Ptr32: OS << " __ptr32"; break;
+    case attr::Ptr64: OS << " __ptr64"; break;
+    case attr::SPtr: OS << " __sptr"; break;
+    case attr::UPtr: OS << " __uptr"; break;
     }
     spaceBeforePlaceHolder(OS);
   }
 
   // Print nullability type specifiers.
-  if (T->getAttrKind() == AttributedType::attr_nonnull ||
-      T->getAttrKind() == AttributedType::attr_nullable ||
-      T->getAttrKind() == AttributedType::attr_null_unspecified) {
-    if (T->getAttrKind() == AttributedType::attr_nonnull)
+  if (T->getImmediateNullability()) {
+    if (T->getAttrKind() == attr::TypeNonNull)
       OS << " _Nonnull";
-    else if (T->getAttrKind() == AttributedType::attr_nullable)
+    else if (T->getAttrKind() == attr::TypeNullable)
       OS << " _Nullable";
-    else if (T->getAttrKind() == AttributedType::attr_null_unspecified)
+    else if (T->getAttrKind() == attr::TypeNullUnspecified)
       OS << " _Null_unspecified";
     else
       llvm_unreachable("unhandled nullability");
     spaceBeforePlaceHolder(OS);
   }
 }
 
 void TypePrinter::printAttributedAfter(const AttributedType *T,
                                        raw_ostream &OS) {
+  // FIXME: Generate this with TableGen.
+
   // Prefer the macro forms of the GC and ownership qualifiers.
-  if (T->getAttrKind() == AttributedType::attr_objc_gc ||
-      T->getAttrKind() == AttributedType::attr_objc_ownership)
+  if (T->getAttrKind() == attr::ObjCGC ||
+      T->getAttrKind() == attr::ObjCOwnership)
     return printAfter(T->getEquivalentType(), OS);
 
   // If this is a calling convention attribute, don't print the implicit CC from
   // the modified type.
   SaveAndRestore<bool> MaybeSuppressCC(InsideCCAttribute, T->isCallingConv());
 
   printAfter(T->getModifiedType(), OS);
 
   // Some attributes are printed as qualifiers before the type, so we have
   // nothing left to do.
-  if (T->getAttrKind() == AttributedType::attr_objc_kindof ||
-      T->isMSTypeSpec() ||
-      T->getAttrKind() == AttributedType::attr_nonnull ||
-      T->getAttrKind() == AttributedType::attr_nullable ||
-      T->getAttrKind() == AttributedType::attr_null_unspecified)
+  if (T->getAttrKind() == attr::ObjCKindOf ||
+      T->isMSTypeSpec() || T->getImmediateNullability())
     return;
 
   // Don't print the inert __unsafe_unretained attribute at all.
-  if (T->getAttrKind() == AttributedType::attr_objc_inert_unsafe_unretained)
+  if (T->getAttrKind() == attr::ObjCInertUnsafeUnretained)
     return;
 
   // Don't print ns_returns_retained unless it had an effect.
-  if (T->getAttrKind() == AttributedType::attr_ns_returns_retained &&
+  if (T->getAttrKind() == attr::NSReturnsRetained &&
       !T->getEquivalentType()->castAs<FunctionType>()
                              ->getExtInfo().getProducesResult())
     return;
 
-  if (T->getAttrKind() == AttributedType::attr_lifetimebound) {
+  if (T->getAttrKind() == attr::LifetimeBound) {
     OS << " [[clang::lifetimebound]]";
     return;
   }
 
   OS << " __attribute__((";
   switch (T->getAttrKind()) {
-  case AttributedType::attr_lifetimebound:
-  case AttributedType::attr_nonnull:
-  case AttributedType::attr_nullable:
-  case AttributedType::attr_null_unspecified:
-  case AttributedType::attr_objc_gc:
-  case AttributedType::attr_objc_inert_unsafe_unretained:
-  case AttributedType::attr_objc_kindof:
-  case AttributedType::attr_objc_ownership:
-  case AttributedType::attr_ptr32:
-  case AttributedType::attr_ptr64:
-  case AttributedType::attr_sptr:
-  case AttributedType::attr_uptr:
+#define TYPE_ATTR(NAME)
+#define DECL_OR_TYPE_ATTR(NAME)
+#define ATTR(NAME) case attr::NAME:
+#include "clang/Basic/AttrList.inc"
+    llvm_unreachable("non-type attribute attached to type");
+
+  case attr::OpenCLPrivateAddressSpace:
+  case attr::OpenCLGlobalAddressSpace:
+  case attr::OpenCLLocalAddressSpace:
+  case attr::OpenCLConstantAddressSpace:
+  case attr::OpenCLGenericAddressSpace:
+    // FIXME: Update printAttributedBefore to print these once we generate
+    // AttributedType nodes for them.
+    break;
+
+  case attr::LifetimeBound:
+  case attr::TypeNonNull:
+  case attr::TypeNullable:
+  case attr::TypeNullUnspecified:
+  case attr::ObjCGC:
+  case attr::ObjCInertUnsafeUnretained:
+  case attr::ObjCKindOf:
+  case attr::ObjCOwnership:
+  case attr::Ptr32:
+  case attr::Ptr64:
+  case attr::SPtr:
+  case attr::UPtr:
     llvm_unreachable("This attribute should have been handled already");
 
-  case AttributedType::attr_address_space:
-    OS << "address_space(";
-    // FIXME: printing the raw LangAS value is wrong. This should probably
-    // use the same code as Qualifiers::print()
-    OS << (unsigned)T->getEquivalentType().getAddressSpace();
-    OS << ')';
-    break;
-
-  case AttributedType::attr_vector_size:
-    OS << "__vector_size__(";
-    if (const auto *vector = T->getEquivalentType()->getAs<VectorType>()) {
-      OS << vector->getNumElements();
-      OS << " * sizeof(";
-      print(vector->getElementType(), OS, StringRef());
-      OS << ')';
-    }
-    OS << ')';
-    break;
-
-  case AttributedType::attr_neon_vector_type:
-  case AttributedType::attr_neon_polyvector_type: {
-    if (T->getAttrKind() == AttributedType::attr_neon_vector_type)
-      OS << "neon_vector_type(";
-    else
-      OS << "neon_polyvector_type(";
-    const auto *vector = T->getEquivalentType()->getAs<VectorType>();
-    OS << vector->getNumElements();
-    OS << ')';
-    break;
-  }
-
-  case AttributedType::attr_regparm: {
-    // FIXME: When Sema learns to form this AttributedType, avoid printing the
-    // attribute again in printFunctionProtoAfter.
-    OS << "regparm(";
-    QualType t = T->getEquivalentType();
-    while (!t->isFunctionType())
-      t = t->getPointeeType();
-    OS << t->getAs<FunctionType>()->getRegParmType();
-    OS << ')';
-    break;
-  }
-
-  case AttributedType::attr_ns_returns_retained:
+  case attr::NSReturnsRetained:
     OS << "ns_returns_retained";
     break;
 
   // FIXME: When Sema learns to form this AttributedType, avoid printing the
   // attribute again in printFunctionProtoAfter.
-  case AttributedType::attr_noreturn: OS << "noreturn"; break;
-  case AttributedType::attr_nocf_check: OS << "nocf_check"; break;
-  case AttributedType::attr_cdecl: OS << "cdecl"; break;
-  case AttributedType::attr_fastcall: OS << "fastcall"; break;
-  case AttributedType::attr_stdcall: OS << "stdcall"; break;
-  case AttributedType::attr_thiscall: OS << "thiscall"; break;
-  case AttributedType::attr_swiftcall: OS << "swiftcall"; break;
-  case AttributedType::attr_vectorcall: OS << "vectorcall"; break;
-  case AttributedType::attr_pascal: OS << "pascal"; break;
-  case AttributedType::attr_ms_abi: OS << "ms_abi"; break;
-  case AttributedType::attr_sysv_abi: OS << "sysv_abi"; break;
-  case AttributedType::attr_regcall: OS << "regcall"; break;
-  case AttributedType::attr_pcs:
-  case AttributedType::attr_pcs_vfp: {
+  case attr::AnyX86NoCfCheck: OS << "nocf_check"; break;
+  case attr::CDecl: OS << "cdecl"; break;
+  case attr::FastCall: OS << "fastcall"; break;
+  case attr::StdCall: OS << "stdcall"; break;
+  case attr::ThisCall: OS << "thiscall"; break;
+  case attr::SwiftCall: OS << "swiftcall"; break;
+  case attr::VectorCall: OS << "vectorcall"; break;
+  case attr::Pascal: OS << "pascal"; break;
+  case attr::MSABI: OS << "ms_abi"; break;
+  case attr::SysVABI: OS << "sysv_abi"; break;
+  case attr::RegCall: OS << "regcall"; break;
+  case attr::Pcs: {
     OS << "pcs(";
    QualType t = T->getEquivalentType();
    while (!t->isFunctionType())
      t = t->getPointeeType();
    OS << (t->getAs<FunctionType>()->getCallConv() == CC_AAPCS ?
          "\"aapcs\"" : "\"aapcs-vfp\"");
    OS << ')';
    break;
   }
 
-  case AttributedType::attr_inteloclbicc: OS << "inteloclbicc"; break;
-  case AttributedType::attr_preserve_most:
+  case attr::IntelOclBicc: OS << "inteloclbicc"; break;
+  case attr::PreserveMost:
     OS << "preserve_most";
     break;
 
-  case AttributedType::attr_preserve_all:
+  case attr::PreserveAll:
     OS << "preserve_all";
     break;
   }
   OS << "))";
 }
 
 void TypePrinter::printObjCInterfaceBefore(const ObjCInterfaceType *T,
                                            raw_ostream &OS) {

lib/Sema/SemaDecl.cpp

if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
     // third operand. See gcc.gnu.org/PR86769.
     AttributedTypeLoc ATL;
     for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
          (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
          TL = ATL.getModifiedLoc()) {
       // The [[lifetimebound]] attribute can be applied to the implicit object
       // parameter of a non-static member function (other than a ctor or dtor)
       // by applying it to the function type.
-      if (ATL.getAttrKind() == AttributedType::attr_lifetimebound) {
+      if (const auto *A = ATL.getAttrAs<LifetimeBoundAttr>()) {
         const auto *MD = dyn_cast<CXXMethodDecl>(FD);
         if (!MD || MD->isStatic()) {
-          S.Diag(ATL.getAttrNameLoc(), diag::err_lifetimebound_no_object_param)
-              << !MD << ATL.getLocalSourceRange();
+          S.Diag(A->getLocation(), diag::err_lifetimebound_no_object_param)
+              << !MD << A->getRange();
         } else if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD)) {
-          S.Diag(ATL.getAttrNameLoc(), diag::err_lifetimebound_ctor_dtor)
-              << isa<CXXDestructorDecl>(MD) << ATL.getLocalSourceRange();
+          S.Diag(A->getLocation(), diag::err_lifetimebound_ctor_dtor)
+              << isa<CXXDestructorDecl>(MD) << A->getRange();
         }
       }
     }
   }
 }
 
 static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
                                            NamedDecl *NewDecl,

lib/Sema/SemaExpr.cpp

         << Var->getDeclName();
     }
     return false;
   }
 
   // Warn about implicitly autoreleasing indirect parameters captured by blocks.
   if (const auto *PT = CaptureType->getAs<PointerType>()) {
     // This function finds out whether there is an AttributedType of kind
-    // attr_objc_ownership in Ty. The existence of AttributedType of kind
-    // attr_objc_ownership implies __autoreleasing was explicitly specified
+    // attr::ObjCOwnership in Ty. The existence of AttributedType of kind
+    // attr::ObjCOwnership implies __autoreleasing was explicitly specified
     // rather than being added implicitly by the compiler.
     auto IsObjCOwnershipAttributedType = [](QualType Ty) {
       while (const auto *AttrTy = Ty->getAs<AttributedType>()) {
-        if (AttrTy->getAttrKind() == AttributedType::attr_objc_ownership)
+        if (AttrTy->getAttrKind() == attr::ObjCOwnership)
           return true;
 
-        // Peel off AttributedTypes that are not of kind objc_ownership.
+        // Peel off AttributedTypes that are not of kind ObjCOwnership.
         Ty = AttrTy->getModifiedType();
       }
 
       return false;
     };
 
     QualType PointeeTy = PT->getPointeeType();
 

lib/Sema/SemaInit.cpp

if (!TSI)
     return false;
   // Don't declare this variable in the second operand of the for-statement;
   // GCC miscompiles that by ending its lifetime before evaluating the
   // third operand. See gcc.gnu.org/PR86769.
   AttributedTypeLoc ATL;
   for (TypeLoc TL = TSI->getTypeLoc();
        (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
        TL = ATL.getModifiedLoc()) {
-    if (ATL.getAttrKind() == AttributedType::attr_lifetimebound)
+    if (ATL.getAttrAs<LifetimeBoundAttr>())
       return true;
   }
   return false;
 }
 
 static void visitLifetimeBoundArguments(IndirectLocalPath &Path, Expr *Call,
                                         LocalVisitor Visit) {
   const FunctionDecl *Callee;

lib/Sema/SemaObjCProperty.cpp

if (!GetterMethod) {
     QualType resultTy = property->getType().getAtomicUnqualifiedType();
 
     // If the property is null_resettable, the getter returns nonnull.
     if (property->getPropertyAttributes() &
         ObjCPropertyDecl::OBJC_PR_null_resettable) {
       QualType modifiedTy = resultTy;
       if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)) {
         if (*nullability == NullabilityKind::Unspecified)
-          resultTy = Context.getAttributedType(AttributedType::attr_nonnull,
+          resultTy = Context.getAttributedType(attr::TypeNonNull,
                                                modifiedTy, modifiedTy);
       }
     }
 
     GetterMethod = ObjCMethodDecl::Create(Context, Loc, Loc,
                              property->getGetterName(),
                              resultTy, nullptr, CD,
                              !IsClassProperty, /*isVariadic=*/false,
if (!SetterMethod) {
 
       // If the property is null_resettable, the setter accepts a
       // nullable value.
       if (property->getPropertyAttributes() &
           ObjCPropertyDecl::OBJC_PR_null_resettable) {
         QualType modifiedTy = paramTy;
         if (auto nullability = AttributedType::stripOuterNullability(modifiedTy)){
           if (*nullability == NullabilityKind::Unspecified)
-            paramTy = Context.getAttributedType(AttributedType::attr_nullable,
+            paramTy = Context.getAttributedType(attr::TypeNullable,
                                                 modifiedTy, modifiedTy);
         }
       }
 
       // Invent the arguments for the setter. We don't bother making a
       // nice name for the argument.
       ParmVarDecl *Argument = ParmVarDecl::Create(Context, SetterMethod,
                                                   Loc, Loc,

lib/Sema/SemaType.cpp

class TypeProcessingState {
 
     /// The original set of attributes on the DeclSpec.
     SmallVector<ParsedAttr *, 2> savedAttrs;
 
     /// A list of attributes to diagnose the uselessness of when the
     /// processing is complete.
     SmallVector<ParsedAttr *, 2> ignoredTypeAttrs;
 
+    /// Attributes corresponding to AttributedTypeLocs that we have not yet
+    /// populated.
+    // FIXME: The two-phase mechanism by which we construct Types and fill
+    // their TypeLocs makes it hard to correctly assign these. We keep the
+    // attributes in creation order as an attempt to make them line up
+    // properly.
+    using TypeAttrPair = std::pair<const AttributedType*, const Attr*>;
+    SmallVector<TypeAttrPair, 8> AttrsForTypes;
+    bool AttrsForTypesSorted = true;
+
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
       : sema(sema), declarator(declarator),
         chunkIndex(declarator.getNumTypeObjects()),
         trivial(true), hasSavedAttrs(false) {}
 
     Sema &getSema() const {
       return sema;
public:
 
     /// Diagnose all the ignored type attributes, given that the
     /// declarator worked out to the given type.
     void diagnoseIgnoredTypeAttrs(QualType type) const {
       for (auto *Attr : ignoredTypeAttrs)
         diagnoseBadTypeAttribute(getSema(), *Attr, type);
     }
 
+    /// Get an attributed type for the given attribute, and remember the Attr
+    /// object so that we can attach it to the AttributedTypeLoc.
+    QualType getAttributedType(Attr *A, QualType ModifiedType,
+                               QualType EquivType) {
+      QualType T =
+          sema.Context.getAttributedType(A->getKind(), ModifiedType, EquivType);
+      AttrsForTypes.push_back({cast<AttributedType>(T.getTypePtr()), A});
+      AttrsForTypesSorted = false;
+      return T;
+    }
+
+    /// Extract and remove the Attr* for a given attributed type.
+    const Attr *takeAttrForAttributedType(const AttributedType *AT) {
+      if (!AttrsForTypesSorted) {
+        std::stable_sort(AttrsForTypes.begin(), AttrsForTypes.end(),
+                         [](const TypeAttrPair &A, const TypeAttrPair &B) {
+                           return A.first < B.first;
+                         });
+        AttrsForTypesSorted = true;
+      }
+
+      // FIXME: This is quadratic if we have lots of reuses of the same
+      // attributed type.
+      for (auto It = std::partition_point(
+               AttrsForTypes.begin(), AttrsForTypes.end(),
+               [=](const TypeAttrPair &A) { return A.first < AT; });
+           It != AttrsForTypes.end() && It->first == AT; ++It) {
+        if (It->second) {
+          const Attr *Result = It->second;
+          It->second = nullptr;
+          return Result;
+        }
+      }
+
+      llvm_unreachable("no Attr* for AttributedType*");
+    }
+
     ~TypeProcessingState() {
       if (trivial) return;
 
       restoreDeclSpecAttrs();
     }
 
   private:
     DeclSpec &getMutableDeclSpec() const {
while (i != 0) {
     case DeclaratorChunk::Pipe:
       // These are invalid anyway, so just ignore.
       break;
     }
   }
   return false;
 }
 
+template<typename AttrT>
+static AttrT *createSimpleAttr(ASTContext &Ctx, ParsedAttr &Attr) {
+  Attr.setUsedAsTypeAttr();
+  return ::new (Ctx)
+      AttrT(Attr.getRange(), Ctx, Attr.getAttributeSpellingListIndex());
+}
+
+static Attr *createNullabilityAttr(ASTContext &Ctx, ParsedAttr &Attr,
+                                   NullabilityKind NK) {
+  switch (NK) {
+  case NullabilityKind::NonNull:
+    return createSimpleAttr<TypeNonNullAttr>(Ctx, Attr);
+
+  case NullabilityKind::Nullable:
+    return createSimpleAttr<TypeNullableAttr>(Ctx, Attr);
+
+  case NullabilityKind::Unspecified:
+    return createSimpleAttr<TypeNullUnspecifiedAttr>(Ctx, Attr);
+  }
+  llvm_unreachable("unknown NullabilityKind");
+}
+
+static TypeSourceInfo *
+GetTypeSourceInfoForDeclarator(TypeProcessingState &State,
+                               QualType T, TypeSourceInfo *ReturnTypeInfo);
+
 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
                                                 QualType declSpecType,
                                                 TypeSourceInfo *TInfo) {
   // The TypeSourceInfo that this function returns will not be a null type.
   // If there is an error, this function will fill in a dummy type as fallback.
   QualType T = declSpecType;
   Declarator &D = state.getDeclarator();
   Sema &S = state.getSema();
if (T->canHaveNullability(/*ResultIfUnknown*/false) &&
           pointerKind = SimplePointerKind::BlockPointer;
         else if (T->isMemberPointerType())
           pointerKind = SimplePointerKind::MemberPointer;
 
         if (auto *attr = inferPointerNullability(
                 pointerKind, D.getDeclSpec().getTypeSpecTypeLoc(),
                 D.getDeclSpec().getLocEnd(),
                 D.getMutableDeclSpec().getAttributes())) {
-          T = Context.getAttributedType(
-                AttributedType::getNullabilityAttrKind(*inferNullability),T,T);
-          attr->setUsedAsTypeAttr();
+          T = state.getAttributedType(
+              createNullabilityAttr(Context, *attr, *inferNullability), T, T);
         }
       }
     }
 
     if (complainAboutMissingNullability == CAMN_Yes &&
         T->isArrayType() && !T->getNullability(S.Context) && !isVaList(T) &&
         D.isPrototypeContext() &&
         !hasOuterPointerLikeChunk(D, D.getNumTypeObjects())) {
case DeclaratorContext::TemplateTypeArgContext:
       break;
     }
   }
 
   assert(!T.isNull() && "T must not be null at the end of this function");
   if (D.isInvalidType())
     return Context.getTrivialTypeSourceInfo(T);
 
-  return S.GetTypeSourceInfoForDeclarator(D, T, TInfo);
+  return GetTypeSourceInfoForDeclarator(state, T, TInfo);
 }
 
 /// GetTypeForDeclarator - Convert the type for the specified
 /// declarator to Type instances.
 ///
 /// The result of this call will never be null, but the associated
 /// type may be a null type if there's an unrecoverable error.
 TypeSourceInfo *Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
if (getLangOpts().ObjC1) {
     Qualifiers::ObjCLifetime ownership = Context.getInnerObjCOwnership(FromTy);
     if (ownership != Qualifiers::OCL_None)
       transferARCOwnership(state, declSpecTy, ownership);
   }
 
   return GetFullTypeForDeclarator(state, declSpecTy, ReturnTypeInfo);
 }
 
-/// Map an AttributedType::Kind to an ParsedAttr::Kind.
-static ParsedAttr::Kind getAttrListKind(AttributedType::Kind kind) {
-  switch (kind) {
-  case AttributedType::attr_address_space:
-    return ParsedAttr::AT_AddressSpace;
-  case AttributedType::attr_regparm:
-    return ParsedAttr::AT_Regparm;
-  case AttributedType::attr_vector_size:
-    return ParsedAttr::AT_VectorSize;
-  case AttributedType::attr_neon_vector_type:
-    return ParsedAttr::AT_NeonVectorType;
-  case AttributedType::attr_neon_polyvector_type:
-    return ParsedAttr::AT_NeonPolyVectorType;
-  case AttributedType::attr_objc_gc:
-    return ParsedAttr::AT_ObjCGC;
-  case AttributedType::attr_objc_ownership:
-  case AttributedType::attr_objc_inert_unsafe_unretained:
-    return ParsedAttr::AT_ObjCOwnership;
-  case AttributedType::attr_noreturn:
-    return ParsedAttr::AT_NoReturn;
-  case AttributedType::attr_nocf_check:
-    return ParsedAttr::AT_AnyX86NoCfCheck;
-  case AttributedType::attr_cdecl:
-    return ParsedAttr::AT_CDecl;
-  case AttributedType::attr_fastcall:
-    return ParsedAttr::AT_FastCall;
-  case AttributedType::attr_stdcall:
-    return ParsedAttr::AT_StdCall;
-  case AttributedType::attr_thiscall:
-    return ParsedAttr::AT_ThisCall;
-  case AttributedType::attr_regcall:
-    return ParsedAttr::AT_RegCall;
-  case AttributedType::attr_pascal:
-    return ParsedAttr::AT_Pascal;
-  case AttributedType::attr_swiftcall:
-    return ParsedAttr::AT_SwiftCall;
-  case AttributedType::attr_vectorcall:
-    return ParsedAttr::AT_VectorCall;
-  case AttributedType::attr_pcs:
-  case AttributedType::attr_pcs_vfp:
-    return ParsedAttr::AT_Pcs;
-  case AttributedType::attr_inteloclbicc:
-    return ParsedAttr::AT_IntelOclBicc;
-  case AttributedType::attr_ms_abi:
-    return ParsedAttr::AT_MSABI;
-  case AttributedType::attr_sysv_abi:
-    return ParsedAttr::AT_SysVABI;
-  case AttributedType::attr_preserve_most:
-    return ParsedAttr::AT_PreserveMost;
-  case AttributedType::attr_preserve_all:
-    return ParsedAttr::AT_PreserveAll;
-  case AttributedType::attr_ptr32:
-    return ParsedAttr::AT_Ptr32;
-  case AttributedType::attr_ptr64:
-    return ParsedAttr::AT_Ptr64;
-  case AttributedType::attr_sptr:
-    return ParsedAttr::AT_SPtr;
-  case AttributedType::attr_uptr:
-    return ParsedAttr::AT_UPtr;
-  case AttributedType::attr_nonnull:
-    return ParsedAttr::AT_TypeNonNull;
-  case AttributedType::attr_nullable:
-    return ParsedAttr::AT_TypeNullable;
-  case AttributedType::attr_null_unspecified:
-    return ParsedAttr::AT_TypeNullUnspecified;
-  case AttributedType::attr_objc_kindof:
-    return ParsedAttr::AT_ObjCKindOf;
-  case AttributedType::attr_ns_returns_retained:
-    return ParsedAttr::AT_NSReturnsRetained;
-  case AttributedType::attr_lifetimebound:
-    return ParsedAttr::AT_LifetimeBound;
-  }
-  llvm_unreachable("unexpected attribute kind!");
-}
-
-static void setAttributedTypeLoc(AttributedTypeLoc TL, const ParsedAttr &attr) {
-  TL.setAttrNameLoc(attr.getLoc());
-  if (TL.hasAttrExprOperand()) {
-    assert(attr.isArgExpr(0) && "mismatched attribute operand kind");
-    TL.setAttrExprOperand(attr.getArgAsExpr(0));
-  } else if (TL.hasAttrEnumOperand()) {
-    assert((attr.isArgIdent(0) || attr.isArgExpr(0)) &&
-           "unexpected attribute operand kind");
-    if (attr.isArgIdent(0))
-      TL.setAttrEnumOperandLoc(attr.getArgAsIdent(0)->Loc);
-    else
-      TL.setAttrEnumOperandLoc(attr.getArgAsExpr(0)->getExprLoc());
-  }
-
-  // FIXME: preserve this information to here.
-  if (TL.hasAttrOperand())
-    TL.setAttrOperandParensRange(SourceRange());
-}
-
 static void fillAttributedTypeLoc(AttributedTypeLoc TL,
-                                  const ParsedAttributesView &Attrs,
-                                  const ParsedAttributesView &DeclAttrs) {
-  // DeclAttrs and Attrs cannot be both empty.
-  assert((!Attrs.empty() || !DeclAttrs.empty()) &&
-         "no type attributes in the expected location!");
-
-  ParsedAttr::Kind parsedKind = getAttrListKind(TL.getAttrKind());
-  // Try to search for an attribute of matching kind in Attrs list.
-  for (const ParsedAttr &AL : Attrs)
-    if (AL.getKind() == parsedKind)
-      return setAttributedTypeLoc(TL, AL);
-
-  for (const ParsedAttr &AL : DeclAttrs)
-    if (AL.isCXX11Attribute() || AL.getKind() == parsedKind)
-      return setAttributedTypeLoc(TL, AL);
-  llvm_unreachable("no matching type attribute in expected location!");
+                                  TypeProcessingState &State) {
+  TL.setAttr(State.takeAttrForAttributedType(TL.getTypePtr()));
 }
 
 namespace {
   class TypeSpecLocFiller : public TypeLocVisitor<TypeSpecLocFiller> {
     ASTContext &Context;
+    TypeProcessingState &State;
     const DeclSpec &DS;
 
   public:
-    TypeSpecLocFiller(ASTContext &Context, const DeclSpec &DS)
-      : Context(Context), DS(DS) {}
+    TypeSpecLocFiller(ASTContext &Context, TypeProcessingState &State,
+                      const DeclSpec &DS)
+        : Context(Context), State(State), DS(DS) {}
 
     void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
-      fillAttributedTypeLoc(TL, DS.getAttributes(), ParsedAttributesView{});
       Visit(TL.getModifiedLoc());
+      fillAttributedTypeLoc(TL, State);
     }
     void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
       Visit(TL.getUnqualifiedLoc());
     }
     void VisitTypedefTypeLoc(TypedefTypeLoc TL) {
       TL.setNameLoc(DS.getTypeSpecTypeLoc());
     }
     void VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
public:
     void VisitTypeLoc(TypeLoc TL) {
       // FIXME: add other typespec types and change this to an assert.
       TL.initialize(Context, DS.getTypeSpecTypeLoc());
     }
   };
 
   class DeclaratorLocFiller : public TypeLocVisitor<DeclaratorLocFiller> {
     ASTContext &Context;
+    TypeProcessingState &State;
     const DeclaratorChunk &Chunk;
 
   public:
-    DeclaratorLocFiller(ASTContext &Context, const DeclaratorChunk &Chunk)
-      : Context(Context), Chunk(Chunk) {}
+    DeclaratorLocFiller(ASTContext &Context, TypeProcessingState &State,
+                        const DeclaratorChunk &Chunk)
+        : Context(Context), State(State), Chunk(Chunk) {}
 
     void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
       llvm_unreachable("qualified type locs not expected here!");
     }
     void VisitDecayedTypeLoc(DecayedTypeLoc TL) {
       llvm_unreachable("decayed type locs not expected here!");
     }
 
     void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
-      fillAttributedTypeLoc(TL, Chunk.getAttrs(), ParsedAttributesView{});
+      fillAttributedTypeLoc(TL, State);
     }
     void VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
       // nothing
     }
     void VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
       assert(Chunk.Kind == DeclaratorChunk::BlockPointer);
       TL.setCaretLoc(Chunk.Loc);
     }

 /// Create and instantiate a TypeSourceInfo with type source information.
 ///
 /// \param T QualType referring to the type as written in source code.
 ///
 /// \param ReturnTypeInfo For declarators whose return type does not show
 /// up in the normal place in the declaration specifiers (such as a C++
 /// conversion function), this pointer will refer to a type source information
 /// for that return type.
-TypeSourceInfo *
-Sema::GetTypeSourceInfoForDeclarator(Declarator &D, QualType T,
-                                     TypeSourceInfo *ReturnTypeInfo) {
-  TypeSourceInfo *TInfo = Context.CreateTypeSourceInfo(T);
+static TypeSourceInfo *
+GetTypeSourceInfoForDeclarator(TypeProcessingState &State,
+                               QualType T, TypeSourceInfo *ReturnTypeInfo) {
+  Sema &S = State.getSema();
+  Declarator &D = State.getDeclarator();
+
+  TypeSourceInfo *TInfo = S.Context.CreateTypeSourceInfo(T);
   UnqualTypeLoc CurrTL = TInfo->getTypeLoc().getUnqualifiedLoc();
 
   // Handle parameter packs whose type is a pack expansion.
   if (isa<PackExpansionType>(T)) {
     CurrTL.castAs<PackExpansionTypeLoc>().setEllipsisLoc(D.getEllipsisLoc());
     CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
   }
 
   for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
-
     if (DependentAddressSpaceTypeLoc DASTL =
         CurrTL.getAs<DependentAddressSpaceTypeLoc>()) {
       fillDependentAddressSpaceTypeLoc(DASTL, D.getTypeObject(i).getAttrs());
       CurrTL = DASTL.getPointeeTypeLoc().getUnqualifiedLoc();
     }
 
     // An AtomicTypeLoc might be produced by an atomic qualifier in this
     // declarator chunk.
     if (AtomicTypeLoc ATL = CurrTL.getAs<AtomicTypeLoc>()) {
       fillAtomicQualLoc(ATL, D.getTypeObject(i));
       CurrTL = ATL.getValueLoc().getUnqualifiedLoc();
     }
 
     while (AttributedTypeLoc TL = CurrTL.getAs<AttributedTypeLoc>()) {
-      fillAttributedTypeLoc(TL, D.getTypeObject(i).getAttrs(),
-                            D.getAttributes());
+      fillAttributedTypeLoc(TL, State);
       CurrTL = TL.getNextTypeLoc().getUnqualifiedLoc();
     }
 
     // FIXME: Ordering here?
     while (AdjustedTypeLoc TL = CurrTL.getAs<AdjustedTypeLoc>())
       CurrTL = TL.getNextTypeLoc().getUnqualifiedLoc();
 
-    DeclaratorLocFiller(Context, D.getTypeObject(i)).Visit(CurrTL);
+    DeclaratorLocFiller(S.Context, State, D.getTypeObject(i)).Visit(CurrTL);
     CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
   }
 
   // If we have different source information for the return type, use
   // that.  This really only applies to C++ conversion functions.
   if (ReturnTypeInfo) {
     TypeLoc TL = ReturnTypeInfo->getTypeLoc();
     assert(TL.getFullDataSize() == CurrTL.getFullDataSize());
     memcpy(CurrTL.getOpaqueData(), TL.getOpaqueData(), TL.getFullDataSize());
   } else {
-    TypeSpecLocFiller(Context, D.getDeclSpec()).Visit(CurrTL);
+    TypeSpecLocFiller(S.Context, State, D.getDeclSpec()).Visit(CurrTL);
   }
 
   return TInfo;
 }
 
 /// Create a LocInfoType to hold the given QualType and TypeSourceInfo.
 ParsedType Sema::CreateParsedType(QualType T, TypeSourceInfo *TInfo) {
   // FIXME: LocInfoTypes are "transient", only needed for passing to/from Parser

 /// "typeof(foo)", where that happens to be strong?
 static bool hasDirectOwnershipQualifier(QualType type) {
   // Fast path: no qualifier at all.
   assert(type.getQualifiers().hasObjCLifetime());
 
   while (true) {
     // __strong id
     if (const AttributedType *attr = dyn_cast<AttributedType>(type)) {
-      if (attr->getAttrKind() == AttributedType::attr_objc_ownership)
+      if (attr->getAttrKind() == attr::ObjCOwnership)
         return true;
 
       type = attr->getModifiedType();
 
     // X *__strong (...)
     } else if (const ParenType *paren = dyn_cast<ParenType>(type)) {
       type = paren->getInnerType();
 
static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
   // but it's easier to just not add the qualifier and instead sniff it out
   // in specific places using isObjCInertUnsafeUnretainedType().
   //
   // Doing this does means we miss some trivial consistency checks that
   // would've triggered in ARC, but that's better than trying to solve all
   // the coexistence problems with __unsafe_unretained.
   if (!S.getLangOpts().ObjCAutoRefCount &&
       lifetime == Qualifiers::OCL_ExplicitNone) {
-    type = S.Context.getAttributedType(
-                             AttributedType::attr_objc_inert_unsafe_unretained,
-                                       type, type);
+    type = state.getAttributedType(
+        createSimpleAttr<ObjCInertUnsafeUnretainedAttr>(S.Context, attr),
     return true;
   }
 
   QualType origType = type;
   if (!NonObjCPointer)
     type = S.Context.getQualifiedType(underlyingType);
 
   // If we have a valid source location for the attribute, use an
   // AttributedType instead.
-  if (AttrLoc.isValid())
-    type = S.Context.getAttributedType(AttributedType::attr_objc_ownership,
-                                       origType, type);
+  if (AttrLoc.isValid()) {
+    type = state.getAttributedType(::new (S.Context) ObjCOwnershipAttr(
+                                       attr.getRange(), S.Context, II,
+                                       attr.getAttributeSpellingListIndex()),
+  }
 
   auto diagnoseOrDelay = [](Sema &S, SourceLocation loc,
                             unsigned diagnostic, QualType type) {
     if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
       S.DelayedDiagnostics.add(
           sema::DelayedDiagnostic::makeForbiddenType(
               S.getSourceManager().getExpansionLoc(loc),
               diagnostic, type, /*ignored*/ 0));
else {
     return true;
   }
 
   QualType origType = type;
   type = S.Context.getObjCGCQualType(origType, GCAttr);
 
   // Make an attributed type to preserve the source information.
   if (attr.getLoc().isValid())
-    type = S.Context.getAttributedType(AttributedType::attr_objc_gc,
-                                       origType, type);
+    type = state.getAttributedType(
+        ::new (S.Context) ObjCGCAttr(attr.getRange(), S.Context, II,
+                                     attr.getAttributeSpellingListIndex()),
 
   return true;
 }
 
 namespace {
   /// A helper class to unwrap a type down to a function for the
   /// purposes of applying attributes there.
   ///
QualType wrap(ASTContext &C, const Type *Old, unsigned I) {
       }
 
       llvm_unreachable("unknown wrapping kind");
     }
   };
 } // end anonymous namespace
 
 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &State,
-                                             ParsedAttr &Attr, QualType &Type) {
+                                             ParsedAttr &PAttr, QualType &Type) {
   Sema &S = State.getSema();
 
-  ParsedAttr::Kind Kind = Attr.getKind();
+  Attr *A;
+  switch (PAttr.getKind()) {
+  default: llvm_unreachable("Unknown attribute kind");
+  case ParsedAttr::AT_Ptr32:
+    A = createSimpleAttr<Ptr32Attr>(S.Context, PAttr);
+    break;
+  case ParsedAttr::AT_Ptr64:
+    A = createSimpleAttr<Ptr64Attr>(S.Context, PAttr);
+    break;
+  case ParsedAttr::AT_SPtr:
+    A = createSimpleAttr<SPtrAttr>(S.Context, PAttr);
+    break;
+  case ParsedAttr::AT_UPtr:
+    A = createSimpleAttr<UPtrAttr>(S.Context, PAttr);
+    break;
+  }
+
+  attr::Kind NewAttrKind = A->getKind();
   QualType Desugared = Type;
   const AttributedType *AT = dyn_cast<AttributedType>(Type);
   while (AT) {
-    AttributedType::Kind CurAttrKind = AT->getAttrKind();
+    attr::Kind CurAttrKind = AT->getAttrKind();
 
     // You cannot specify duplicate type attributes, so if the attribute has
     // already been applied, flag it.
-    if (getAttrListKind(CurAttrKind) == Kind) {
-      S.Diag(Attr.getLoc(), diag::warn_duplicate_attribute_exact)
-        << Attr.getName();
+    if (NewAttrKind == CurAttrKind) {
+      S.Diag(PAttr.getLoc(), diag::warn_duplicate_attribute_exact)
+        << PAttr.getName();
       return true;
     }
 
     // You cannot have both __sptr and __uptr on the same type, nor can you
     // have __ptr32 and __ptr64.
-    if ((CurAttrKind == AttributedType::attr_ptr32 &&
-         Kind == ParsedAttr::AT_Ptr64) ||
-        (CurAttrKind == AttributedType::attr_ptr64 &&
-         Kind == ParsedAttr::AT_Ptr32)) {
-      S.Diag(Attr.getLoc(), diag::err_attributes_are_not_compatible)
+    if ((CurAttrKind == attr::Ptr32 && NewAttrKind == attr::Ptr64) ||
+        (CurAttrKind == attr::Ptr64 && NewAttrKind == attr::Ptr32)) {
+      S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
         << "'__ptr32'" << "'__ptr64'";
       return true;
-    } else if ((CurAttrKind == AttributedType::attr_sptr &&
-                Kind == ParsedAttr::AT_UPtr) ||
-               (CurAttrKind == AttributedType::attr_uptr &&
-                Kind == ParsedAttr::AT_SPtr)) {
-      S.Diag(Attr.getLoc(), diag::err_attributes_are_not_compatible)
+    } else if ((CurAttrKind == attr::SPtr && NewAttrKind == attr::UPtr) ||
+               (CurAttrKind == attr::UPtr && NewAttrKind == attr::SPtr)) {
+      S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
         << "'__sptr'" << "'__uptr'";
       return true;
     }
 
     Desugared = AT->getEquivalentType();
     AT = dyn_cast<AttributedType>(Desugared);
   }
 
   // Pointer type qualifiers can only operate on pointer types, but not
   // pointer-to-member types.
+  //
+  // FIXME: Should we really be disallowing this attribute if there is any
+  // type sugar between it and the pointer (other than attributes)? Eg, this
+  // disallows the attribute on a parenthesized pointer.
+  // And if so, should we really allow *any* type attribute?
   if (!isa<PointerType>(Desugared)) {
     if (Type->isMemberPointerType())
-      S.Diag(Attr.getLoc(), diag::err_attribute_no_member_pointers)
-          << Attr.getName();
+      S.Diag(PAttr.getLoc(), diag::err_attribute_no_member_pointers)
+          << PAttr.getName();
     else
-      S.Diag(Attr.getLoc(), diag::err_attribute_pointers_only)
-          << Attr.getName() << 0;
+      S.Diag(PAttr.getLoc(), diag::err_attribute_pointers_only)
+          << PAttr.getName() << 0;
     return true;
   }
 
-  AttributedType::Kind TAK;
-  switch (Kind) {
-  default: llvm_unreachable("Unknown attribute kind");
-  case ParsedAttr::AT_Ptr32:
-    TAK = AttributedType::attr_ptr32;
-    break;
-  case ParsedAttr::AT_Ptr64:
-    TAK = AttributedType::attr_ptr64;
-    break;
-  case ParsedAttr::AT_SPtr:
-    TAK = AttributedType::attr_sptr;
-    break;
-  case ParsedAttr::AT_UPtr:
-    TAK = AttributedType::attr_uptr;
-    break;
-  }
+  Type = State.getAttributedType(A, Type, Type);
+  return false;
 
-  Type = S.Context.getAttributedType(TAK, Type, Type);
-  return false;
+/// Map a nullability attribute kind to a nullability kind.
+static NullabilityKind mapNullabilityAttrKind(ParsedAttr::Kind kind) {
+  switch (kind) {
+  case ParsedAttr::AT_TypeNonNull:
+    return NullabilityKind::NonNull;
+
+  case ParsedAttr::AT_TypeNullable:
+    return NullabilityKind::Nullable;
+
+  case ParsedAttr::AT_TypeNullUnspecified:
+    return NullabilityKind::Unspecified;
+
+  default:
+    llvm_unreachable("not a nullability attribute kind");
+  }
 }
 
-bool Sema::checkNullabilityTypeSpecifier(QualType &type,
-                                         NullabilityKind nullability,
-                                         SourceLocation nullabilityLoc,
-                                         bool isContextSensitive,
+/// Applies a nullability type specifier to the given type, if possible.
+///
+/// \param state The type processing state.
+///
+/// \param type The type to which the nullability specifier will be
+/// added. On success, this type will be updated appropriately.
+///
+/// \param attr The attribute as written on the type.
+///
+/// \param allowArrayTypes Whether to accept nullability specifiers on an
+/// array type (e.g., because it will decay to a pointer).
+///
+/// \returns true if a problem has been diagnosed, false on success.
+static bool checkNullabilityTypeSpecifier(TypeProcessingState &state,
+                                          QualType &type,
+                                          ParsedAttr &attr,
                                           bool allowOnArrayType) {
-  recordNullabilitySeen(*this, nullabilityLoc);
+  Sema &S = state.getSema();
+
+  NullabilityKind nullability = mapNullabilityAttrKind(attr.getKind());
+  SourceLocation nullabilityLoc = attr.getLoc();
+  bool isContextSensitive = attr.isContextSensitiveKeywordAttribute();
+
+  recordNullabilitySeen(S, nullabilityLoc);
 
   // Check for existing nullability attributes on the type.
   QualType desugared = type;
   while (auto attributed = dyn_cast<AttributedType>(desugared.getTypePtr())) {
     // Check whether there is already a null
     if (auto existingNullability = attributed->getImmediateNullability()) {
       // Duplicated nullability.
       if (nullability == *existingNullability) {
-        Diag(nullabilityLoc, diag::warn_nullability_duplicate)
+        S.Diag(nullabilityLoc, diag::warn_nullability_duplicate)
           << DiagNullabilityKind(nullability, isContextSensitive)
           << FixItHint::CreateRemoval(nullabilityLoc);
 
         break;
       }
 
       // Conflicting nullability.
-      Diag(nullabilityLoc, diag::err_nullability_conflicting)
+      S.Diag(nullabilityLoc, diag::err_nullability_conflicting)
         << DiagNullabilityKind(nullability, isContextSensitive)
         << DiagNullabilityKind(*existingNullability, false);
       return true;
     }
 
     desugared = attributed->getModifiedType();
   }
 
   // If there is already a different nullability specifier, complain.
   // This (unlike the code above) looks through typedefs that might
   // have nullability specifiers on them, which means we cannot
   // provide a useful Fix-It.
-  if (auto existingNullability = desugared->getNullability(Context)) {
+  if (auto existingNullability = desugared->getNullability(S.Context)) {
     if (nullability != *existingNullability) {
-      Diag(nullabilityLoc, diag::err_nullability_conflicting)
+      S.Diag(nullabilityLoc, diag::err_nullability_conflicting)
         << DiagNullabilityKind(nullability, isContextSensitive)
         << DiagNullabilityKind(*existingNullability, false);
 
       // Try to find the typedef with the existing nullability specifier.
       if (auto typedefType = desugared->getAs<TypedefType>()) {
         TypedefNameDecl *typedefDecl = typedefType->getDecl();
         QualType underlyingType = typedefDecl->getUnderlyingType();
         if (auto typedefNullability
               = AttributedType::stripOuterNullability(underlyingType)) {
           if (*typedefNullability == *existingNullability) {
-            Diag(typedefDecl->getLocation(), diag::note_nullability_here)
+            S.Diag(typedefDecl->getLocation(), diag::note_nullability_here)
               << DiagNullabilityKind(*existingNullability, false);
           }
         }
       }
 
       return true;
     }
   }
 
   // If this definitely isn't a pointer type, reject the specifier.
   if (!desugared->canHaveNullability() &&
       !(allowOnArrayType && desugared->isArrayType())) {
-    Diag(nullabilityLoc, diag::err_nullability_nonpointer)
+    S.Diag(nullabilityLoc, diag::err_nullability_nonpointer)
       << DiagNullabilityKind(nullability, isContextSensitive) << type;
     return true;
   }
 
   // For the context-sensitive keywords/Objective-C property
   // attributes, require that the type be a single-level pointer.
   if (isContextSensitive) {
     // Make sure that the pointee isn't itself a pointer type.
     const Type *pointeeType;
     if (desugared->isArrayType())
       pointeeType = desugared->getArrayElementTypeNoTypeQual();
     else
       pointeeType = desugared->getPointeeType().getTypePtr();
 
     if (pointeeType->isAnyPointerType() ||
         pointeeType->isObjCObjectPointerType() ||
         pointeeType->isMemberPointerType()) {
-      Diag(nullabilityLoc, diag::err_nullability_cs_multilevel)
+      S.Diag(nullabilityLoc, diag::err_nullability_cs_multilevel)
         << DiagNullabilityKind(nullability, true)
         << type;
-      Diag(nullabilityLoc, diag::note_nullability_type_specifier)
+      S.Diag(nullabilityLoc, diag::note_nullability_type_specifier)
         << DiagNullabilityKind(nullability, false)
         << type
         << FixItHint::CreateReplacement(nullabilityLoc,
                                         getNullabilitySpelling(nullability));
       return true;
     }
   }
 
   // Form the attributed type.
-  type = Context.getAttributedType(
-           AttributedType::getNullabilityAttrKind(nullability), type, type);
+  type = state.getAttributedType(
+      createNullabilityAttr(S.Context, attr, nullability), type, type);
   return false;
 }
 
-bool Sema::checkObjCKindOfType(QualType &type, SourceLocation loc) {
+/// Check the application of the Objective-C '__kindof' qualifier to
+/// the given type.
+static bool checkObjCKindOfType(TypeProcessingState &state, QualType &type,
+                                ParsedAttr &attr) {
+  Sema &S = state.getSema();
+
   if (isa<ObjCTypeParamType>(type)) {
     // Build the attributed type to record where __kindof occurred.
-    type = Context.getAttributedType(AttributedType::attr_objc_kindof,
-                                     type, type);
+    type = state.getAttributedType(
+        createSimpleAttr<ObjCKindOfAttr>(S.Context, attr), type, type);
     return false;
   }
 
   // Find out if it's an Objective-C object or object pointer type;
   const ObjCObjectPointerType *ptrType = type->getAs<ObjCObjectPointerType>();
   const ObjCObjectType *objType = ptrType ? ptrType->getObjectType()
                                           : type->getAs<ObjCObjectType>();
 
   // If not, we can't apply __kindof.
   if (!objType) {
     // FIXME: Handle dependent types that aren't yet object types.
-    Diag(loc, diag::err_objc_kindof_nonobject)
+    S.Diag(attr.getLoc(), diag::err_objc_kindof_nonobject)
       << type;
     return true;
   }
 
   // Rebuild the "equivalent" type, which pushes __kindof down into
   // the object type.
   // There is no need to apply kindof on an unqualified id type.
-  QualType equivType = Context.getObjCObjectType(
+  QualType equivType = S.Context.getObjCObjectType(
       objType->getBaseType(), objType->getTypeArgsAsWritten(),
       objType->getProtocols(),
       /*isKindOf=*/objType->isObjCUnqualifiedId() ? false : true);
 
   // If we started with an object pointer type, rebuild it.
   if (ptrType) {
-    equivType = Context.getObjCObjectPointerType(equivType);
-    if (auto nullability = type->getNullability(Context)) {
-      auto attrKind = AttributedType::getNullabilityAttrKind(*nullability);
-      equivType = Context.getAttributedType(attrKind, equivType, equivType);
+    equivType = S.Context.getObjCObjectPointerType(equivType);
+    if (auto nullability = type->getNullability(S.Context)) {
+      // We create a nullability attribute from the __kindof attribute.
+      // Make sure that will make sense.
+      assert(attr.getAttributeSpellingListIndex() == 0 &&
+             "multiple spellings for __kindof?");
+      Attr *A = createNullabilityAttr(S.Context, attr, *nullability);
+      A->setImplicit(true);
+      equivType = state.getAttributedType(A, equivType, equivType);
     }
   }
 
   // Build the attributed type to record where __kindof occurred.
-  type = Context.getAttributedType(AttributedType::attr_objc_kindof,
-                                   type,
-                                   equivType);
-
+  type = state.getAttributedType(
+      createSimpleAttr<ObjCKindOfAttr>(S.Context, attr), type, equivType);
   return false;
 }
 
-/// Map a nullability attribute kind to a nullability kind.
-static NullabilityKind mapNullabilityAttrKind(ParsedAttr::Kind kind) {
-  switch (kind) {
-  case ParsedAttr::AT_TypeNonNull:
-    return NullabilityKind::NonNull;
-
-  case ParsedAttr::AT_TypeNullable:
-    return NullabilityKind::Nullable;
-
-  case ParsedAttr::AT_TypeNullUnspecified:
-    return NullabilityKind::Unspecified;
-
-  default:
-    llvm_unreachable("not a nullability attribute kind");
-  }
-}
-
 /// Distribute a nullability type attribute that cannot be applied to
 /// the type specifier to a pointer, block pointer, or member pointer
 /// declarator, complaining if necessary.
 ///
 /// \returns true if the nullability annotation was distributed, false
 /// otherwise.
 static bool distributeNullabilityTypeAttr(TypeProcessingState &state,
                                           QualType type, ParsedAttr &attr) {
for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
     case DeclaratorChunk::Pipe:
       return false;
     }
   }
 
   return false;
 }
 
-static AttributedType::Kind getCCTypeAttrKind(ParsedAttr &Attr) {
+static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
   assert(!Attr.isInvalid());
   switch (Attr.getKind()) {
   default:
     llvm_unreachable("not a calling convention attribute");
   case ParsedAttr::AT_CDecl:
-    return AttributedType::attr_cdecl;
+    return createSimpleAttr<CDeclAttr>(Ctx, Attr);
   case ParsedAttr::AT_FastCall:
-    return AttributedType::attr_fastcall;
+    return createSimpleAttr<FastCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_StdCall:
-    return AttributedType::attr_stdcall;
+    return createSimpleAttr<StdCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_ThisCall:
-    return AttributedType::attr_thiscall;
+    return createSimpleAttr<ThisCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_RegCall:
-    return AttributedType::attr_regcall;
+    return createSimpleAttr<RegCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_Pascal:
-    return AttributedType::attr_pascal;
+    return createSimpleAttr<PascalAttr>(Ctx, Attr);
   case ParsedAttr::AT_SwiftCall:
-    return AttributedType::attr_swiftcall;
+    return createSimpleAttr<SwiftCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_VectorCall:
-    return AttributedType::attr_vectorcall;
+    return createSimpleAttr<VectorCallAttr>(Ctx, Attr);
   case ParsedAttr::AT_Pcs: {
     // The attribute may have had a fixit applied where we treated an
     // identifier as a string literal.  The contents of the string are valid,
     // but the form may not be.
     StringRef Str;
     if (Attr.isArgExpr(0))
       Str = cast<StringLiteral>(Attr.getArgAsExpr(0))->getString();
     else
       Str = Attr.getArgAsIdent(0)->Ident->getName();
-    return llvm::StringSwitch<AttributedType::Kind>(Str)
-        .Case("aapcs", AttributedType::attr_pcs)
-        .Case("aapcs-vfp", AttributedType::attr_pcs_vfp);
+    PcsAttr::PCSType Type;
+    if (!PcsAttr::ConvertStrToPCSType(Str, Type))
+      llvm_unreachable("already validated the attribute");
+    return ::new (Ctx) PcsAttr(Attr.getRange(), Ctx, Type,
+                               Attr.getAttributeSpellingListIndex());
   }
   case ParsedAttr::AT_IntelOclBicc:
-    return AttributedType::attr_inteloclbicc;
+    return createSimpleAttr<IntelOclBiccAttr>(Ctx, Attr);
   case ParsedAttr::AT_MSABI:
-    return AttributedType::attr_ms_abi;
+    return createSimpleAttr<MSABIAttr>(Ctx, Attr);
   case ParsedAttr::AT_SysVABI:
-    return AttributedType::attr_sysv_abi;
+    return createSimpleAttr<SysVABIAttr>(Ctx, Attr);
   case ParsedAttr::AT_PreserveMost:
-    return AttributedType::attr_preserve_most;
+    return createSimpleAttr<PreserveMostAttr>(Ctx, Attr);
   case ParsedAttr::AT_PreserveAll:
-    return AttributedType::attr_preserve_all;
+    return createSimpleAttr<PreserveAllAttr>(Ctx, Attr);
   }
   llvm_unreachable("unexpected attribute kind!");
 }
 
 /// Process an individual function attribute.  Returns true to
 /// indicate that the attribute was handled, false if it wasn't.
 static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
                                    QualType &type) {
if (attr.getKind() == ParsedAttr::AT_NSReturnsRetained) {
 
     // Only actually change the underlying type in ARC builds.
     QualType origType = type;
     if (state.getSema().getLangOpts().ObjCAutoRefCount) {
       FunctionType::ExtInfo EI
         = unwrapped.get()->getExtInfo().withProducesResult(true);
       type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
     }
-    type = S.Context.getAttributedType(AttributedType::attr_ns_returns_retained,
-                                       origType, type);
+    type = state.getAttributedType(
+        createSimpleAttr<NSReturnsRetainedAttr>(S.Context, attr),
     return true;
   }
 
   if (attr.getKind() == ParsedAttr::AT_AnyX86NoCallerSavedRegisters) {
     if (S.CheckAttrTarget(attr) || S.CheckAttrNoArgs(attr))
       return true;
 
     // Delay if this is not a function type.
static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
 
   // Otherwise, a calling convention.
   CallingConv CC;
   if (S.CheckCallingConvAttr(attr, CC))
     return true;
 
   const FunctionType *fn = unwrapped.get();
   CallingConv CCOld = fn->getCallConv();
-  AttributedType::Kind CCAttrKind = getCCTypeAttrKind(attr);
+  Attr *CCAttr = getCCTypeAttr(S.Context, attr);
 
   if (CCOld != CC) {
     // Error out on when there's already an attribute on the type
     // and the CCs don't match.
-    const AttributedType *AT = S.getCallingConvAttributedType(type);
-    if (AT && AT->getAttrKind() != CCAttrKind) {
+    if (const AttributedType *AT = S.getCallingConvAttributedType(type)) {
       S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
         << FunctionType::getNameForCallConv(CC)
         << FunctionType::getNameForCallConv(CCOld);
       attr.setInvalid();
       return true;
     }
   }
 
static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
   QualType Equivalent;
   if (CCOld == CC) {
     Equivalent = type;
   } else {
     auto EI = unwrapped.get()->getExtInfo().withCallingConv(CC);
     Equivalent =
       unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
   }
-  type = S.Context.getAttributedType(CCAttrKind, type, Equivalent);
+  type = state.getAttributedType(CCAttr, type, Equivalent);
   return true;
 }
 
 bool Sema::hasExplicitCallingConv(QualType &T) {
   QualType R = T.IgnoreParens();
   while (const AttributedType *AT = dyn_cast<AttributedType>(R)) {
     if (AT->isCallingConv())
       return true;
if (IsPointee) {
           ImpAddr = LangAS::opencl_private;
         }
       }
     }
   }
   T = State.getSema().Context.getAddrSpaceQualType(T, ImpAddr);
 }
 
-static void HandleLifetimeBoundAttr(QualType &CurType,
-                                    const ParsedAttr &Attr,
-                                    Sema &S, Declarator &D) {
-  if (D.isDeclarationOfFunction()) {
-    CurType = S.Context.getAttributedType(AttributedType::attr_lifetimebound,
-                                          CurType, CurType);
+static void HandleLifetimeBoundAttr(TypeProcessingState &State,
+                                    QualType &CurType,
+                                    ParsedAttr &Attr) {
+  if (State.getDeclarator().isDeclarationOfFunction()) {
+    CurType = State.getAttributedType(
+        createSimpleAttr<LifetimeBoundAttr>(State.getSema().Context, Attr),
   } else {
-    Attr.diagnoseAppertainsTo(S, nullptr);
+    Attr.diagnoseAppertainsTo(State.getSema(), nullptr);
   }
 }
 
 
 static void processTypeAttrs(TypeProcessingState &state, QualType &type,
                              TypeAttrLocation TAL,
                              ParsedAttributesView &attrs) {
   // Scan through and apply attributes to this type where it makes sense.  Some
case ParsedAttr::AT_NeonPolyVectorType:
                                VectorType::NeonPolyVector);
       attr.setUsedAsTypeAttr();
       break;
     case ParsedAttr::AT_OpenCLAccess:
       HandleOpenCLAccessAttr(type, attr, state.getSema());
       attr.setUsedAsTypeAttr();
       break;
     case ParsedAttr::AT_LifetimeBound:
-      if (TAL == TAL_DeclChunk) {
-        HandleLifetimeBoundAttr(type, attr, state.getSema(),
-                                state.getDeclarator());
-        attr.setUsedAsTypeAttr();
-      }
+      if (TAL == TAL_DeclChunk)
+        HandleLifetimeBoundAttr(state, type, attr);
       break;
 
     MS_TYPE_ATTRS_CASELIST:
       if (!handleMSPointerTypeQualifierAttr(state, attr, type))
         attr.setUsedAsTypeAttr();
       break;
 
 
     NULLABILITY_TYPE_ATTRS_CASELIST:
       // Either add nullability here or try to distribute it.  We
       // don't want to distribute the nullability specifier past any
       // dependent type, because that complicates the user model.
       if (type->canHaveNullability() || type->isDependentType() ||
           type->isArrayType() ||
           !distributeNullabilityTypeAttr(state, type, attr)) {
         unsigned endIndex;
         if (TAL == TAL_DeclChunk)
           endIndex = state.getCurrentChunkIndex();
         else
           endIndex = state.getDeclarator().getNumTypeObjects();
         bool allowOnArrayType =
             state.getDeclarator().isPrototypeContext() &&
             !hasOuterPointerLikeChunk(state.getDeclarator(), endIndex);
-        if (state.getSema().checkNullabilityTypeSpecifier(
+        if (checkNullabilityTypeSpecifier(
+              state, 
               type,
-              mapNullabilityAttrKind(attr.getKind()),
-              attr.getLoc(),
-              attr.isContextSensitiveKeywordAttribute(),
+              attr,
               allowOnArrayType)) {
           attr.setInvalid();
         }
 
         attr.setUsedAsTypeAttr();
       }
       break;
 
case ParsedAttr::AT_ObjCKindOf:
                              diag::err_objc_kindof_wrong_position)
           << FixItHint::CreateRemoval(attr.getLoc())
           << FixItHint::CreateInsertion(
                state.getDeclarator().getDeclSpec().getLocStart(), "__kindof ");
         break;
       }
 
       // Apply it regardless.
-      if (state.getSema().checkObjCKindOfType(type, attr.getLoc()))
+      if (checkObjCKindOfType(state, type, attr))
         attr.setInvalid();
-      attr.setUsedAsTypeAttr();
       break;
 
     FUNCTION_TYPE_ATTRS_CASELIST:
       attr.setUsedAsTypeAttr();
 
       // Never process function type attributes as part of the
       // declaration-specifiers.
       if (TAL == TAL_DeclSpec)

lib/Sema/TreeTransform.h

 QualType TreeTransform<Derived>::TransformAttributedType(
                                                 TypeLocBuilder &TLB,
                                                 AttributedTypeLoc TL) {
   const AttributedType *oldType = TL.getTypePtr();
   QualType modifiedType = getDerived().TransformType(TLB, TL.getModifiedLoc());
   if (modifiedType.isNull())
     return QualType();
 
+  const Attr *oldAttr = TL.getAttr();
+  const Attr *newAttr = getDerived().TransformAttr(oldAttr);
+  if (!newAttr)
+    return QualType();
+
   QualType result = TL.getType();
 
   // FIXME: dependent operand expressions?
   if (getDerived().AlwaysRebuild() ||
       modifiedType != oldType->getModifiedType()) {
     // TODO: this is really lame; we should really be rebuilding the
     // equivalent type from first principles.
     QualType equivalentType
       = getDerived().TransformType(oldType->getEquivalentType());
     if (equivalentType.isNull())
       return QualType();
 
     // Check whether we can add nullability; it is only represented as
     // type sugar, and therefore cannot be diagnosed in any other way.
     if (auto nullability = oldType->getImmediateNullability()) {
       if (!modifiedType->canHaveNullability()) {
-        SemaRef.Diag(TL.getAttrNameLoc(), diag::err_nullability_nonpointer)
+        SemaRef.Diag(TL.getAttr()->getLocation(),
+                     diag::err_nullability_nonpointer)
             << DiagNullabilityKind(*nullability, false) << modifiedType;
         return QualType();
       }
     }
 
-    result = SemaRef.Context.getAttributedType(oldType->getAttrKind(),
+    result = SemaRef.Context.getAttributedType(newAttr->getKind(),
                                                modifiedType,
                                                equivalentType);
   }
 
   AttributedTypeLoc newTL = TLB.push<AttributedTypeLoc>(result);
-  newTL.setAttrNameLoc(TL.getAttrNameLoc());
-  if (TL.hasAttrOperand())
-    newTL.setAttrOperandParensRange(TL.getAttrOperandParensRange());
-  if (TL.hasAttrExprOperand())
-    newTL.setAttrExprOperand(TL.getAttrExprOperand());
-  else if (TL.hasAttrEnumOperand())
-    newTL.setAttrEnumOperandLoc(TL.getAttrEnumOperandLoc());
-
+  newTL.setAttr(newAttr);
   return result;
 }
 
 template<typename Derived>
 QualType
 TreeTransform<Derived>::TransformParenType(TypeLocBuilder &TLB,
                                            ParenTypeLoc TL) {
   QualType Inner = getDerived().TransformType(TLB, TL.getInnerLoc());

lib/Serialization/ASTReader.cpp

class TypeLocReader : public TypeLocVisitor<TypeLocReader> {
   TypeSourceInfo *GetTypeSourceInfo() {
     return Reader->GetTypeSourceInfo(*F, Record, Idx);
   }
 
   NestedNameSpecifierLoc ReadNestedNameSpecifierLoc() {
     return Reader->ReadNestedNameSpecifierLoc(*F, Record, Idx);
   }
 
+  Attr *ReadAttr() {
+    return Reader->ReadAttr(*F, Record, Idx);
+  }
+
 public:
   TypeLocReader(ModuleFile &F, ASTReader &Reader,
                 const ASTReader::RecordData &Record, unsigned &Idx)
       : F(&F), Reader(&Reader), Record(Record), Idx(Idx) {}
 
   // We want compile-time assurance that we've enumerated all of
   // these, so unfortunately we have to declare them first, then
   // define them out-of-line.
void TypeLocReader::VisitRecordTypeLoc(RecordTypeLoc TL) {
   TL.setNameLoc(ReadSourceLocation());
 }
 
 void TypeLocReader::VisitEnumTypeLoc(EnumTypeLoc TL) {
   TL.setNameLoc(ReadSourceLocation());
 }
 
 void TypeLocReader::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
-  TL.setAttrNameLoc(ReadSourceLocation());
-  if (TL.hasAttrOperand()) {
-    SourceRange range;
-    range.setBegin(ReadSourceLocation());
-    range.setEnd(ReadSourceLocation());
-    TL.setAttrOperandParensRange(range);
-  }
-  if (TL.hasAttrExprOperand()) {
-    if (Record[Idx++])
-      TL.setAttrExprOperand(Reader->ReadExpr(*F));
-    else
-      TL.setAttrExprOperand(nullptr);
-  } else if (TL.hasAttrEnumOperand())
-    TL.setAttrEnumOperandLoc(ReadSourceLocation());
+  TL.setAttr(ReadAttr());
 }
 
 void TypeLocReader::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
   TL.setNameLoc(ReadSourceLocation());
 }
 
 void TypeLocReader::VisitSubstTemplateTypeParmTypeLoc(
                                             SubstTemplateTypeParmTypeLoc TL) {

lib/Serialization/ASTReaderDecl.cpp

 void ASTDeclReader::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
   VisitVarDecl(D);
 }
 
 //===----------------------------------------------------------------------===//
 // Attribute Reading
 //===----------------------------------------------------------------------===//
 
-/// Reads attributes from the current stream position.
-void ASTReader::ReadAttributes(ASTRecordReader &Record, AttrVec &Attrs) {
-  for (unsigned i = 0, e = Record.readInt(); i != e; ++i) {
-    Attr *New = nullptr;
-    auto Kind = (attr::Kind)Record.readInt();
-    SourceRange Range = Record.readSourceRange();
-    ASTContext &Context = getContext();
+namespace {
+class AttrReader {
+  ModuleFile *F;
+  ASTReader *Reader;
+  const ASTReader::RecordData &Record;
+  unsigned &Idx;
+
+public:
+  AttrReader(ModuleFile &F, ASTReader &Reader,
+             const ASTReader::RecordData &Record, unsigned &Idx)
+      : F(&F), Reader(&Reader), Record(Record), Idx(Idx) {}
+
+  const uint64_t &readInt() { return Record[Idx++]; }
+
+  SourceRange readSourceRange() {
+    return Reader->ReadSourceRange(*F, Record, Idx);
+  }
+
+  Expr *readExpr() { return Reader->ReadExpr(*F); }
+
+  std::string readString() {
+    return Reader->ReadString(Record, Idx);
+  }
+
+  TypeSourceInfo *getTypeSourceInfo() {
+    return Reader->GetTypeSourceInfo(*F, Record, Idx);
+  }
+
+  IdentifierInfo *getIdentifierInfo() {
+    return Reader->GetIdentifierInfo(*F, Record, Idx);
+  }
+
+  VersionTuple readVersionTuple() {
+    return ASTReader::ReadVersionTuple(Record, Idx);
+  }
+
+  template <typename T> T *GetLocalDeclAs(uint32_t LocalID) {
+    return cast_or_null<T>(Reader->GetLocalDecl(*F, LocalID));
+  }
+};
+}
+
+Attr *ASTReader::ReadAttr(ModuleFile &M, const RecordData &Rec,
+                          unsigned &Idx) {
+  AttrReader Record(M, *this, Rec, Idx);
+  auto V = Record.readInt();
+  if (!V)
+    return nullptr;
+
+  // Kind is stored as a 1-based integer because 0 is used to indicate a null
+  // Attr pointer.
+  auto Kind = static_cast<attr::Kind>(V - 1);
 
 #include "clang/Serialization/AttrPCHRead.inc"
 
-    assert(New && "Unable to decode attribute?");
-    Attrs.push_back(New);
-  }
+  return New;
+
+/// Reads attributes from the current stream position.
+void ASTReader::ReadAttributes(ASTRecordReader &Record, AttrVec &Attrs) {
+  for (unsigned I = 0, E = Record.readInt(); I != E; ++I)
+    Attrs.push_back(Record.readAttr());
 }
 
 //===----------------------------------------------------------------------===//
 // ASTReader Implementation
 //===----------------------------------------------------------------------===//
 
 /// Note that we have loaded the declaration with the given
 /// Index.

lib/Serialization/ASTWriter.cpp

void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
   Record.AddSourceLocation(TL.getNameLoc());
 }
 
 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
   Record.AddSourceLocation(TL.getNameLoc());
 }
 
 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
-  Record.AddSourceLocation(TL.getAttrNameLoc());
-  if (TL.hasAttrOperand()) {
-    SourceRange range = TL.getAttrOperandParensRange();
-    Record.AddSourceLocation(range.getBegin());
-    Record.AddSourceLocation(range.getEnd());
-  }
-  if (TL.hasAttrExprOperand()) {
-    Expr *operand = TL.getAttrExprOperand();
-    Record.push_back(operand ? 1 : 0);
-    if (operand) Record.AddStmt(operand);
-  } else if (TL.hasAttrEnumOperand()) {
-    Record.AddSourceLocation(TL.getAttrEnumOperandLoc());
-  }
+  Record.AddAttr(TL.getAttr());
 }
 
 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
   Record.AddSourceLocation(TL.getNameLoc());
 }
 
 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
                                             SubstTemplateTypeParmTypeLoc TL) {
void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
   // Exit the extension block.
   Stream.ExitBlock();
 }
 
 //===----------------------------------------------------------------------===//
 // General Serialization Routines
 //===----------------------------------------------------------------------===//
 
-/// Emit the list of attributes to the specified record.
-void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
+void ASTRecordWriter::AddAttr(const Attr *A) {
   auto &Record = *this;
-  Record.push_back(Attrs.size());
-  for (const auto *A : Attrs) {
-    Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
-    Record.AddSourceRange(A->getRange());
+  if (!A)
+    return Record.push_back(0);
+  Record.push_back(A->getKind() + 1); // FIXME: stable encoding, target attrs
 
 #include "clang/Serialization/AttrPCHWrite.inc"
-  }
+
+/// Emit the list of attributes to the specified record.
+void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
+  push_back(Attrs.size());
+  for (const auto *A : Attrs)
+    AddAttr(A);
 }
 
 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
   AddSourceLocation(Tok.getLocation(), Record);
   Record.push_back(Tok.getLength());
 
   // FIXME: When reading literal tokens, reconstruct the literal pointer
   // if it is needed.

lib/StaticAnalyzer/Core/CheckerHelpers.cpp

parseAssignment(const Stmt *S) {
 
   return std::make_pair(VD, RHS);
 }
 
 Nullability getNullabilityAnnotation(QualType Type) {
   const auto *AttrType = Type->getAs<AttributedType>();
   if (!AttrType)
     return Nullability::Unspecified;
-  if (AttrType->getAttrKind() == AttributedType::attr_nullable)
+  if (AttrType->getAttrKind() == attr::TypeNullable)
     return Nullability::Nullable;
-  else if (AttrType->getAttrKind() == AttributedType::attr_nonnull)
+  else if (AttrType->getAttrKind() == attr::TypeNonNull)
     return Nullability::Nonnull;
   return Nullability::Unspecified;
 }
 
 
 } // end namespace ento
 } // end namespace clang

utils/TableGen/ClangAttrEmitter.cpp

struct AttrClassDescriptor {
     const char * const MacroName;
     const char * const TableGenName;
   };
 
 } // end anonymous namespace
 
 static const AttrClassDescriptor AttrClassDescriptors[] = {
   { "ATTR", "Attr" },
+  { "TYPE_ATTR", "TypeAttr" },
   { "STMT_ATTR", "StmtAttr" },
   { "INHERITABLE_ATTR", "InheritableAttr" },
+  { "DECL_OR_TYPE_ATTR", "DeclOrTypeAttr" },
   { "INHERITABLE_PARAM_ATTR", "InheritableParamAttr" },
   { "PARAMETER_ABI_ATTR", "ParameterABIAttr" }
 };
 
 static void emitDefaultDefine(raw_ostream &OS, StringRef name,
                               const char *superName) {
   OS << "#ifndef " << name << "\n";
   OS << "#define " << name << "(NAME) ";