[HLSL] Implement SpirvType and SpirvOpaqueType

This implements the design proposed by [Representing SpirvType in
Clang's Type System](llvm/wg-hlsl#181). It
creates `HLSLInlineSpirvType` as a new `Type` subclass, and
`__hlsl_spirv_type` as a new builtin type template to create such a
type.

This new type is lowered to the `spirv.Type` target extension type, as
described in [Target Extension Types for Inline SPIR-V and Decorated
Types](https://github.com/llvm/wg-hlsl/blob/main/proposals/0017-inline-spirv-and-decorated-types.md).

Author: cassiebeckley

clang/include/clang-c/Index.h

@@ -3034,7 +3034,8 @@ enum CXTypeKind {
 
   /* HLSL Types */
   CXType_HLSLResource = 179,
-  CXType_HLSLAttributedResource = 180
+  CXType_HLSLAttributedResource = 180,
+  CXType_HLSLInlineSpirv = 181
 };
 
 /**

clang/include/clang/AST/ASTContext.h

@@ -260,6 +260,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
       DependentBitIntTypes;
   mutable llvm::FoldingSet<BTFTagAttributedType> BTFTagAttributedTypes;
   llvm::FoldingSet<HLSLAttributedResourceType> HLSLAttributedResourceTypes;
+  llvm::FoldingSet<HLSLInlineSpirvType> HLSLInlineSpirvTypes;
 
   mutable llvm::FoldingSet<CountAttributedType> CountAttributedTypes;
 
@@ -1795,6 +1796,10 @@ class ASTContext : public RefCountedBase<ASTContext> {
       QualType Wrapped, QualType Contained,
       const HLSLAttributedResourceType::Attributes &Attrs);
 
+  QualType getHLSLInlineSpirvType(uint32_t Opcode, uint32_t Size,
+                                  uint32_t Alignment,
+                                  ArrayRef<SpirvOperand> Operands);
+
   QualType
   getSubstTemplateTypeParmType(QualType Replacement, Decl *AssociatedDecl,
                                unsigned Index,

clang/include/clang/AST/ASTNodeTraverser.h

@@ -450,6 +450,24 @@ class ASTNodeTraverser
     if (!Contained.isNull())
       Visit(Contained);
   }
+  void VisitHLSLInlineSpirvType(const HLSLInlineSpirvType *T) {
+    for (auto &Operand : T->getOperands()) {
+      using SpirvOperandKind = SpirvOperand::SpirvOperandKind;
+
+      switch (Operand.getKind()) {
+      case SpirvOperandKind::kConstantId:
+      case SpirvOperandKind::kLiteral:
+        break;
+
+      case SpirvOperandKind::kTypeId:
+        Visit(Operand.getResultType());
+        break;
+
+      default:
+        llvm_unreachable("Invalid SpirvOperand kind!");
+      }
+    }
+  }
   void VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *) {}
   void
   VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {

clang/include/clang/AST/PropertiesBase.td

@@ -147,6 +147,7 @@ def UInt64 : CountPropertyType<"uint64_t">;
 def UnaryTypeTransformKind : EnumPropertyType<"UnaryTransformType::UTTKind">;
 def VectorKind : EnumPropertyType<"VectorKind">;
 def TypeCoupledDeclRefInfo : PropertyType;
+def HLSLSpirvOperand : PropertyType<"SpirvOperand"> { let PassByReference = 1; }
 
 def ExceptionSpecInfo : PropertyType<"FunctionProtoType::ExceptionSpecInfo"> {
   let BufferElementTypes = [ QualType ];

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -1154,6 +1154,14 @@ DEF_TRAVERSE_TYPE(BTFTagAttributedType,
 DEF_TRAVERSE_TYPE(HLSLAttributedResourceType,
                   { TRY_TO(TraverseType(T->getWrappedType())); })
 
+DEF_TRAVERSE_TYPE(HLSLInlineSpirvType, {
+  for (auto &Operand : T->getOperands()) {
+    if (Operand.isConstant() || Operand.isType()) {
+      TRY_TO(TraverseType(Operand.getResultType()));
+    }
+  }
+})
+
 DEF_TRAVERSE_TYPE(ParenType, { TRY_TO(TraverseType(T->getInnerType())); })
 
 DEF_TRAVERSE_TYPE(MacroQualifiedType,
@@ -1457,6 +1465,9 @@ DEF_TRAVERSE_TYPELOC(BTFTagAttributedType,
 DEF_TRAVERSE_TYPELOC(HLSLAttributedResourceType,
                      { TRY_TO(TraverseTypeLoc(TL.getWrappedLoc())); })
 
+DEF_TRAVERSE_TYPELOC(HLSLInlineSpirvType,
+                     { TRY_TO(TraverseType(TL.getType())); })
+
 DEF_TRAVERSE_TYPELOC(ElaboratedType, {
   if (TL.getQualifierLoc()) {
     TRY_TO(TraverseNestedNameSpecifierLoc(TL.getQualifierLoc()));

clang/include/clang/AST/Type.h

@@ -2652,6 +2652,7 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
   bool isHLSLSpecificType() const; // Any HLSL specific type
   bool isHLSLBuiltinIntangibleType() const; // Any HLSL builtin intangible type
   bool isHLSLAttributedResourceType() const;
+  bool isHLSLInlineSpirvType() const;
   bool isHLSLResourceRecord() const;
   bool isHLSLIntangibleType()
       const; // Any HLSL intangible type (builtin, array, class)
@@ -6330,6 +6331,140 @@ class HLSLAttributedResourceType : public Type, public llvm::FoldingSetNode {
   findHandleTypeOnResource(const Type *RT);
 };
 
+/// Instances of this class represent operands to a SPIR-V type instruction.
+class SpirvOperand {
+public:
+  enum SpirvOperandKind : unsigned char {
+    kInvalid,    ///< Uninitialized.
+    kConstantId, ///< Integral value to represent as a SPIR-V OpConstant
+                 ///< instruction ID.
+    kLiteral,    ///< Integral value to represent as an immediate literal.
+    kTypeId,     ///< Type to represent as a SPIR-V type ID.
+
+    kMax,
+  };
+
+private:
+  SpirvOperandKind Kind = kInvalid;
+
+  QualType ResultType;
+  llvm::APInt Value; // Signedness of constants is represented by ResultType.
+
+public:
+  SpirvOperand() : Kind(kInvalid), ResultType() {}
+
+  SpirvOperand(SpirvOperandKind Kind, QualType ResultType, llvm::APInt Value)
+      : Kind(Kind), ResultType(ResultType), Value(Value) {}
+
+  SpirvOperand(const SpirvOperand &Other) { *this = Other; }
+  ~SpirvOperand() {}
+
+  SpirvOperand &operator=(const SpirvOperand &Other) {
+    this->Kind = Other.Kind;
+    this->ResultType = Other.ResultType;
+    this->Value = Other.Value;
+    return *this;
+  }
+
+  bool operator==(const SpirvOperand &Other) const {
+    return Kind == Other.Kind && ResultType == Other.ResultType &&
+           Value == Other.Value;
+  }
+
+  bool operator!=(const SpirvOperand &Other) const { return !(*this == Other); }
+
+  SpirvOperandKind getKind() const { return Kind; }
+
+  bool isValid() const { return Kind != kInvalid && Kind < kMax; }
+  bool isConstant() const { return Kind == kConstantId; }
+  bool isLiteral() const { return Kind == kLiteral; }
+  bool isType() const { return Kind == kTypeId; }
+
+  llvm::APInt getValue() const {
+    assert((isConstant() || isLiteral()) &&
+           "This is not an operand with a value!");
+    return Value;
+  }
+
+  QualType getResultType() const {
+    assert((isConstant() || isType()) &&
+           "This is not an operand with a result type!");
+    return ResultType;
+  }
+
+  static SpirvOperand createConstant(QualType ResultType, llvm::APInt Val) {
+    return SpirvOperand(kConstantId, ResultType, Val);
+  }
+
+  static SpirvOperand createLiteral(llvm::APInt Val) {
+    return SpirvOperand(kLiteral, QualType(), Val);
+  }
+
+  static SpirvOperand createType(QualType T) {
+    return SpirvOperand(kTypeId, T, llvm::APSInt());
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    ID.AddInteger(Kind);
+    ID.AddPointer(ResultType.getAsOpaquePtr());
+    Value.Profile(ID);
+  }
+};
+
+/// Represents an arbitrary, user-specified SPIR-V type instruction.
+class HLSLInlineSpirvType final
+    : public Type,
+      public llvm::FoldingSetNode,
+      private llvm::TrailingObjects<HLSLInlineSpirvType, SpirvOperand> {
+  friend class ASTContext; // ASTContext creates these
+  friend TrailingObjects;
+
+private:
+  uint32_t Opcode;
+  uint32_t Size;
+  uint32_t Alignment;
+  size_t NumOperands;
+
+  HLSLInlineSpirvType(uint32_t Opcode, uint32_t Size, uint32_t Alignment,
+                      ArrayRef<SpirvOperand> Operands)
+      : Type(HLSLInlineSpirv, QualType(), TypeDependence::None), Opcode(Opcode),
+        Size(Size), Alignment(Alignment), NumOperands(Operands.size()) {
+    for (size_t I = 0; I < NumOperands; I++) {
+      getTrailingObjects<SpirvOperand>()[I] = Operands[I];
+    }
+  }
+
+public:
+  uint32_t getOpcode() const { return Opcode; }
+  uint32_t getSize() const { return Size; }
+  uint32_t getAlignment() const { return Alignment; }
+  ArrayRef<SpirvOperand> getOperands() const {
+    return {getTrailingObjects<SpirvOperand>(), NumOperands};
+  }
+
+  bool isSugared() const { return false; }
+  QualType desugar() const { return QualType(this, 0); }
+
+  void Profile(llvm::FoldingSetNodeID &ID) {
+    Profile(ID, Opcode, Size, Alignment, getOperands());
+  }
+
+  static void Profile(llvm::FoldingSetNodeID &ID, uint32_t Opcode,
+                      uint32_t Size, uint32_t Alignment,
+                      ArrayRef<SpirvOperand> Operands) {
+    ID.AddInteger(Opcode);
+    ID.AddInteger(Size);
+    ID.AddInteger(Alignment);
+    for (auto &Operand : Operands) {
+      Operand.Profile(ID);
+    }
+  }
+
+  static bool classof(const Type *T) {
+    return T->getTypeClass() == HLSLInlineSpirv;
+  }
+};
+
 class TemplateTypeParmType : public Type, public llvm::FoldingSetNode {
   friend class ASTContext; // ASTContext creates these
 
@@ -8458,13 +8593,18 @@ inline bool Type::isHLSLBuiltinIntangibleType() const {
 }
 
 inline bool Type::isHLSLSpecificType() const {
-  return isHLSLBuiltinIntangibleType() || isHLSLAttributedResourceType();
+  return isHLSLBuiltinIntangibleType() || isHLSLAttributedResourceType() ||
+         isHLSLInlineSpirvType();
 }
 
 inline bool Type::isHLSLAttributedResourceType() const {
   return isa<HLSLAttributedResourceType>(this);
 }
 
+inline bool Type::isHLSLInlineSpirvType() const {
+  return isa<HLSLInlineSpirvType>(this);
+}
+
 inline bool Type::isTemplateTypeParmType() const {
   return isa<TemplateTypeParmType>(CanonicalType);
 }

clang/include/clang/AST/TypeLoc.h

@@ -973,6 +973,25 @@ class HLSLAttributedResourceTypeLoc
   }
 };
 
+struct HLSLInlineSpirvTypeLocInfo {
+  SourceLocation Loc;
+}; // Nothing.
+
+class HLSLInlineSpirvTypeLoc
+    : public ConcreteTypeLoc<UnqualTypeLoc, HLSLInlineSpirvTypeLoc,
+                             HLSLInlineSpirvType, HLSLInlineSpirvTypeLocInfo> {
+public:
+  SourceLocation getSpirvTypeLoc() const { return getLocalData()->Loc; }
+  void setSpirvTypeLoc(SourceLocation loc) const { getLocalData()->Loc = loc; }
+
+  SourceRange getLocalSourceRange() const {
+    return SourceRange(getSpirvTypeLoc(), getSpirvTypeLoc());
+  }
+  void initializeLocal(ASTContext &Context, SourceLocation loc) {
+    setSpirvTypeLoc(loc);
+  }
+};
+
 struct ObjCObjectTypeLocInfo {
   SourceLocation TypeArgsLAngleLoc;
   SourceLocation TypeArgsRAngleLoc;

clang/include/clang/AST/TypeProperties.td

@@ -719,6 +719,24 @@ let Class = HLSLAttributedResourceType in {
   }]>;
 }
 
+let Class = HLSLInlineSpirvType in {
+  def : Property<"opcode", UInt32> {
+    let Read = [{ node->getOpcode() }];
+  }
+  def : Property<"size", UInt32> {
+    let Read = [{ node->getSize() }];
+  }
+  def : Property<"alignment", UInt32> {
+    let Read = [{ node->getAlignment() }];
+  }
+  def : Property<"operands", Array<HLSLSpirvOperand>> {
+    let Read = [{ node->getOperands() }];
+  }
+  def : Creator<[{
+    return ctx.getHLSLInlineSpirvType(opcode, size, alignment, operands);
+  }]>;
+}
+
 let Class = DependentAddressSpaceType in {
   def : Property<"pointeeType", QualType> {
     let Read = [{ node->getPointeeType() }];

clang/include/clang/Basic/BuiltinTemplates.td

@@ -28,25 +28,37 @@ class BuiltinNTTP<string type_name> : TemplateArg<""> {
 }
 
 def SizeT : BuiltinNTTP<"size_t"> {}
+def Uint32T: BuiltinNTTP<"uint32_t"> {}
 
 class BuiltinTemplate<list<TemplateArg> template_head> {
   list<TemplateArg> TemplateHead = template_head;
 }
 
+class CPlusPlusBuiltinTemplate<list<TemplateArg> template_head> : BuiltinTemplate<template_head>;
+
+class HLSLBuiltinTemplate<list<TemplateArg> template_head> : BuiltinTemplate<template_head>;
+
 // template <template <class T, T... Ints> IntSeq, class T, T N>
-def __make_integer_seq : BuiltinTemplate<
+def __make_integer_seq : CPlusPlusBuiltinTemplate<
   [Template<[Class<"T">, NTTP<"T", "Ints", /*is_variadic=*/1>], "IntSeq">, Class<"T">, NTTP<"T", "N">]>;
 
 // template <size_t, class... T>
-def __type_pack_element : BuiltinTemplate<
+def __type_pack_element : CPlusPlusBuiltinTemplate<
   [SizeT, Class<"T", /*is_variadic=*/1>]>;
 
 // template <template <class... Args> BaseTemplate,
 //           template <class TypeMember> HasTypeMember,
 //           class HasNoTypeMember
 //           class... Ts>
-def __builtin_common_type : BuiltinTemplate<
+def __builtin_common_type : CPlusPlusBuiltinTemplate<
   [Template<[Class<"Args", /*is_variadic=*/1>], "BaseTemplate">,
    Template<[Class<"TypeMember">], "HasTypeMember">,
    Class<"HasNoTypeMember">,
    Class<"Ts", /*is_variadic=*/1>]>;
+
+// template <uint32_t Opcode,
+//           uint32_t Size,
+//           uint32_t Alignment,
+//           typename ...Operands>
+def __hlsl_spirv_type : HLSLBuiltinTemplate<
+[Uint32T, Uint32T, Uint32T, Class<"Operands", /*is_variadic=*/1>]>;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -12709,6 +12709,9 @@ def err_hlsl_expect_arg_const_int_one_or_neg_one: Error<
 def err_invalid_hlsl_resource_type: Error<
   "invalid __hlsl_resource_t type attributes">;
 
+def err_hlsl_spirv_only: Error<"%0 is only available for the SPIR-V target">;
+def err_hlsl_vk_literal_must_contain_constant: Error<"the argument to vk::Literal must be a vk::integral_constant">;
+
 // Layout randomization diagnostics.
 def err_non_designated_init_used : Error<
   "a randomized struct can only be initialized with a designated initializer">;