//===- ExtractAPI/API.h -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines the APIRecord-based structs and the APISet class.
///
/// Clang ExtractAPI is a tool to collect API information from a given set of
/// header files. The structures in this file describe data representations of
/// the API information collected for various kinds of symbols.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_EXTRACTAPI_API_H
#define LLVM_CLANG_EXTRACTAPI_API_H

#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RawCommentList.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/Specifiers.h"
#include "clang/ExtractAPI/AvailabilityInfo.h"
#include "clang/ExtractAPI/DeclarationFragments.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/TargetParser/Triple.h"
#include <memory>
#include <type_traits>

namespace clang {
namespace extractapi {

class Template {
  struct TemplateParameter {
    // "class", "typename", or concept name
    std::string Type;
    std::string Name;
    unsigned int Index;
    unsigned int Depth;
    bool IsParameterPack;

    TemplateParameter(std::string Type, std::string Name, unsigned int Index,
                      unsigned int Depth, bool IsParameterPack)
        : Type(Type), Name(Name), Index(Index), Depth(Depth),
          IsParameterPack(IsParameterPack) {}
  };

  struct TemplateConstraint {
    // type name of the constraint, if it has one
    std::string Type;
    std::string Kind;
    std::string LHS, RHS;
  };
  llvm::SmallVector<TemplateParameter> Parameters;
  llvm::SmallVector<TemplateConstraint> Constraints;

public:
  Template() = default;

  Template(const TemplateDecl *Decl) {
    for (auto *const Parameter : *Decl->getTemplateParameters()) {
      const auto *Param = dyn_cast<TemplateTypeParmDecl>(Parameter);
      if (!Param) // some params are null
        continue;
      std::string Type;
      if (Param->hasTypeConstraint())
        Type = Param->getTypeConstraint()->getNamedConcept()->getName().str();
      else if (Param->wasDeclaredWithTypename())
        Type = "typename";
      else
        Type = "class";

      addTemplateParameter(Type, Param->getName().str(), Param->getIndex(),
                           Param->getDepth(), Param->isParameterPack());
    }
  }

  Template(const ClassTemplatePartialSpecializationDecl *Decl) {
    for (auto *const Parameter : *Decl->getTemplateParameters()) {
      const auto *Param = dyn_cast<TemplateTypeParmDecl>(Parameter);
      if (!Param) // some params are null
        continue;
      std::string Type;
      if (Param->hasTypeConstraint())
        Type = Param->getTypeConstraint()->getNamedConcept()->getName().str();
      else if (Param->wasDeclaredWithTypename())
        Type = "typename";
      else
        Type = "class";

      addTemplateParameter(Type, Param->getName().str(), Param->getIndex(),
                           Param->getDepth(), Param->isParameterPack());
    }
  }

  Template(const VarTemplatePartialSpecializationDecl *Decl) {
    for (auto *const Parameter : *Decl->getTemplateParameters()) {
      const auto *Param = dyn_cast<TemplateTypeParmDecl>(Parameter);
      if (!Param) // some params are null
        continue;
      std::string Type;
      if (Param->hasTypeConstraint())
        Type = Param->getTypeConstraint()->getNamedConcept()->getName().str();
      else if (Param->wasDeclaredWithTypename())
        Type = "typename";
      else
        Type = "class";

      addTemplateParameter(Type, Param->getName().str(), Param->getIndex(),
                           Param->getDepth(), Param->isParameterPack());
    }
  }

  const llvm::SmallVector<TemplateParameter> &getParameters() const {
    return Parameters;
  }

  const llvm::SmallVector<TemplateConstraint> &getConstraints() const {
    return Constraints;
  }

  void addTemplateParameter(std::string Type, std::string Name,
                            unsigned int Index, unsigned int Depth,
                            bool IsParameterPack) {
    Parameters.emplace_back(Type, Name, Index, Depth, IsParameterPack);
  }

  bool empty() const { return Parameters.empty() && Constraints.empty(); }
};

/// DocComment is a vector of RawComment::CommentLine.
///
/// Each line represents one line of striped documentation comment,
/// with source range information. This simplifies calculating the source
/// location of a character in the doc comment for pointing back to the source
/// file.
/// e.g.
/// \code
///   /// This is a documentation comment
///       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'  First line.
///   ///     with multiple lines.
///       ^~~~~~~~~~~~~~~~~~~~~~~'         Second line.
/// \endcode
using DocComment = std::vector<RawComment::CommentLine>;

// Classes deriving from APIRecord need to have USR be the first constructor
// argument. This is so that they are compatible with `addTopLevelRecord`
// defined in API.cpp
/// The base representation of an API record. Holds common symbol information.
struct APIRecord {
  /// Discriminator for LLVM-style RTTI (dyn_cast<> et al.)
  enum RecordKind {
    RK_Unknown,
    RK_Namespace,
    RK_GlobalFunction,
    RK_GlobalFunctionTemplate,
    RK_GlobalFunctionTemplateSpecialization,
    RK_GlobalVariable,
    RK_GlobalVariableTemplate,
    RK_GlobalVariableTemplateSpecialization,
    RK_GlobalVariableTemplatePartialSpecialization,
    RK_EnumConstant,
    RK_Enum,
    RK_StructField,
    RK_Struct,
    RK_UnionField,
    RK_Union,
    RK_StaticField,
    RK_CXXField,
    RK_CXXFieldTemplate,
    RK_CXXClass,
    RK_ClassTemplate,
    RK_ClassTemplateSpecialization,
    RK_ClassTemplatePartialSpecialization,
    RK_Concept,
    RK_CXXStaticMethod,
    RK_CXXInstanceMethod,
    RK_CXXConstructorMethod,
    RK_CXXDestructorMethod,
    RK_CXXMethodTemplate,
    RK_CXXMethodTemplateSpecialization,
    RK_ObjCInstanceProperty,
    RK_ObjCClassProperty,
    RK_ObjCIvar,
    RK_ObjCClassMethod,
    RK_ObjCInstanceMethod,
    RK_ObjCInterface,
    RK_ObjCCategory,
    RK_ObjCCategoryModule,
    RK_ObjCProtocol,
    RK_MacroDefinition,
    RK_Typedef,
  };

  /// Stores information about the context of the declaration of this API.
  /// This is roughly analogous to the DeclContext hierarchy for an AST Node.
  struct HierarchyInformation {
    /// The USR of the parent API.
    StringRef ParentUSR;
    /// The name of the parent API.
    StringRef ParentName;
    /// The record kind of the parent API.
    RecordKind ParentKind = RK_Unknown;
    /// A pointer to the parent APIRecord if known.
    APIRecord *ParentRecord = nullptr;

    HierarchyInformation() = default;
    HierarchyInformation(StringRef ParentUSR, StringRef ParentName,
                         RecordKind Kind, APIRecord *ParentRecord = nullptr)
        : ParentUSR(ParentUSR), ParentName(ParentName), ParentKind(Kind),
          ParentRecord(ParentRecord) {}

    bool empty() const {
      return ParentUSR.empty() && ParentName.empty() &&
             ParentKind == RK_Unknown && ParentRecord == nullptr;
    }
  };

  StringRef USR;
  StringRef Name;
  PresumedLoc Location;
  AvailabilityInfo Availability;
  LinkageInfo Linkage;

  /// Documentation comment lines attached to this symbol declaration.
  DocComment Comment;

  /// Declaration fragments of this symbol declaration.
  DeclarationFragments Declaration;

  /// SubHeading provides a more detailed representation than the plain
  /// declaration name.
  ///
  /// SubHeading is an array of declaration fragments of tagged declaration
  /// name, with potentially more tokens (for example the \c +/- symbol for
  /// Objective-C class/instance methods).
  DeclarationFragments SubHeading;

  /// Information about the parent record of this record.
  HierarchyInformation ParentInformation;

  /// Whether the symbol was defined in a system header.
  bool IsFromSystemHeader;

private:
  const RecordKind Kind;

public:
  RecordKind getKind() const { return Kind; }

  APIRecord() = delete;

  APIRecord(RecordKind Kind, StringRef USR, StringRef Name,
            PresumedLoc Location, AvailabilityInfo Availability,
            LinkageInfo Linkage, const DocComment &Comment,
            DeclarationFragments Declaration, DeclarationFragments SubHeading,
            bool IsFromSystemHeader)
      : USR(USR), Name(Name), Location(Location),
        Availability(std::move(Availability)), Linkage(Linkage),
        Comment(Comment), Declaration(Declaration), SubHeading(SubHeading),
        IsFromSystemHeader(IsFromSystemHeader), Kind(Kind) {}

  APIRecord(RecordKind Kind, StringRef USR, StringRef Name)
      : USR(USR), Name(Name), Kind(Kind) {}

  // Pure virtual destructor to make APIRecord abstract
  virtual ~APIRecord() = 0;
};

struct NamespaceRecord : APIRecord {
  NamespaceRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                  AvailabilityInfo Availability, LinkageInfo Linkage,
                  const DocComment &Comment, DeclarationFragments Declaration,
                  DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : APIRecord(RK_Namespace, USR, Name, Loc, std::move(Availability),
                  Linkage, Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_Namespace;
  }
};

/// This holds information associated with global functions.
struct GlobalFunctionRecord : APIRecord {
  FunctionSignature Signature;

  GlobalFunctionRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                       AvailabilityInfo Availability, LinkageInfo Linkage,
                       const DocComment &Comment,
                       DeclarationFragments Declaration,
                       DeclarationFragments SubHeading,
                       FunctionSignature Signature, bool IsFromSystemHeader)
      : APIRecord(RK_GlobalFunction, USR, Name, Loc, std::move(Availability),
                  Linkage, Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Signature(Signature) {}

  GlobalFunctionRecord(RecordKind Kind, StringRef USR, StringRef Name,
                       PresumedLoc Loc, AvailabilityInfo Availability,
                       LinkageInfo Linkage, const DocComment &Comment,
                       DeclarationFragments Declaration,
                       DeclarationFragments SubHeading,
                       FunctionSignature Signature, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability), Linkage,
                  Comment, Declaration, SubHeading, IsFromSystemHeader),
        Signature(Signature) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalFunction;
  }

private:
  virtual void anchor();
};

struct GlobalFunctionTemplateRecord : GlobalFunctionRecord {
  Template Templ;

  GlobalFunctionTemplateRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                               AvailabilityInfo Availability,
                               LinkageInfo Linkage, const DocComment &Comment,
                               DeclarationFragments Declaration,
                               DeclarationFragments SubHeading,
                               FunctionSignature Signature, Template Template,
                               bool IsFromSystemHeader)
      : GlobalFunctionRecord(RK_GlobalFunctionTemplate, USR, Name, Loc,
                             std::move(Availability), Linkage, Comment,
                             Declaration, SubHeading, Signature,
                             IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalFunctionTemplate;
  }
};

struct GlobalFunctionTemplateSpecializationRecord : GlobalFunctionRecord {
  GlobalFunctionTemplateSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, FunctionSignature Signature,
      bool IsFromSystemHeader)
      : GlobalFunctionRecord(RK_GlobalFunctionTemplateSpecialization, USR, Name,
                             Loc, std::move(Availability), Linkage, Comment,
                             Declaration, SubHeading, Signature,
                             IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalFunctionTemplateSpecialization;
  }
};

/// This holds information associated with global functions.
struct GlobalVariableRecord : APIRecord {
  GlobalVariableRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                       AvailabilityInfo Availability, LinkageInfo Linkage,
                       const DocComment &Comment,
                       DeclarationFragments Declaration,
                       DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : APIRecord(RK_GlobalVariable, USR, Name, Loc, std::move(Availability),
                  Linkage, Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  GlobalVariableRecord(RecordKind Kind, StringRef USR, StringRef Name,
                       PresumedLoc Loc, AvailabilityInfo Availability,
                       LinkageInfo Linkage, const DocComment &Comment,
                       DeclarationFragments Declaration,
                       DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability), Linkage,
                  Comment, Declaration, SubHeading, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalVariable;
  }

private:
  virtual void anchor();
};

struct GlobalVariableTemplateRecord : GlobalVariableRecord {
  Template Templ;

  GlobalVariableTemplateRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                               AvailabilityInfo Availability,
                               LinkageInfo Linkage, const DocComment &Comment,
                               DeclarationFragments Declaration,
                               DeclarationFragments SubHeading,
                               class Template Template, bool IsFromSystemHeader)
      : GlobalVariableRecord(RK_GlobalVariableTemplate, USR, Name, Loc,
                             std::move(Availability), Linkage, Comment,
                             Declaration, SubHeading, IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalVariableTemplate;
  }
};

struct GlobalVariableTemplateSpecializationRecord : GlobalVariableRecord {
  GlobalVariableTemplateSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : GlobalVariableRecord(RK_GlobalVariableTemplateSpecialization, USR, Name,
                             Loc, std::move(Availability), Linkage, Comment,
                             Declaration, SubHeading, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalVariableTemplateSpecialization;
  }
};

struct GlobalVariableTemplatePartialSpecializationRecord
    : GlobalVariableRecord {
  Template Templ;

  GlobalVariableTemplatePartialSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, class Template Template,
      bool IsFromSystemHeader)
      : GlobalVariableRecord(RK_GlobalVariableTemplatePartialSpecialization,
                             USR, Name, Loc, std::move(Availability), Linkage,
                             Comment, Declaration, SubHeading,
                             IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_GlobalVariableTemplatePartialSpecialization;
  }
};

/// This holds information associated with enum constants.
struct EnumConstantRecord : APIRecord {
  EnumConstantRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                     AvailabilityInfo Availability, const DocComment &Comment,
                     DeclarationFragments Declaration,
                     DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : APIRecord(RK_EnumConstant, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_EnumConstant;
  }

private:
  virtual void anchor();
};

/// This holds information associated with enums.
struct EnumRecord : APIRecord {
  SmallVector<std::unique_ptr<EnumConstantRecord>> Constants;

  EnumRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
             AvailabilityInfo Availability, const DocComment &Comment,
             DeclarationFragments Declaration, DeclarationFragments SubHeading,
             bool IsFromSystemHeader)
      : APIRecord(RK_Enum, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_Enum;
  }

private:
  virtual void anchor();
};

/// This holds information associated with struct fields.
struct RecordFieldRecord : APIRecord {
  RecordFieldRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                    AvailabilityInfo Availability, const DocComment &Comment,
                    DeclarationFragments Declaration,
                    DeclarationFragments SubHeading, RecordKind Kind,
                    bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_StructField ||
           Record->getKind() == RK_UnionField;
  }

private:
  virtual void anchor();
};

/// This holds information associated with structs.
struct RecordRecord : APIRecord {
  SmallVector<std::unique_ptr<RecordFieldRecord>> Fields;

  RecordRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
               AvailabilityInfo Availability, const DocComment &Comment,
               DeclarationFragments Declaration,
               DeclarationFragments SubHeading, RecordKind Kind,
               bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_Struct || Record->getKind() == RK_Union;
  }

private:
  virtual void anchor();
};

struct CXXFieldRecord : APIRecord {
  AccessControl Access;

  CXXFieldRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                 AvailabilityInfo Availability, const DocComment &Comment,
                 DeclarationFragments Declaration,
                 DeclarationFragments SubHeading, AccessControl Access,
                 bool IsFromSystemHeader)
      : APIRecord(RK_CXXField, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Access(Access) {}

  CXXFieldRecord(RecordKind Kind, StringRef USR, StringRef Name,
                 PresumedLoc Loc, AvailabilityInfo Availability,
                 const DocComment &Comment, DeclarationFragments Declaration,
                 DeclarationFragments SubHeading, AccessControl Access,
                 bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Access(Access) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXField;
  }

private:
  virtual void anchor();
};

struct CXXFieldTemplateRecord : CXXFieldRecord {
  Template Templ;

  CXXFieldTemplateRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                         AvailabilityInfo Availability,
                         const DocComment &Comment,
                         DeclarationFragments Declaration,
                         DeclarationFragments SubHeading, AccessControl Access,
                         Template Template, bool IsFromSystemHeader)
      : CXXFieldRecord(RK_CXXFieldTemplate, USR, Name, Loc,
                       std::move(Availability), Comment, Declaration,
                       SubHeading, Access, IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXFieldTemplate;
  }
};

struct CXXMethodRecord : APIRecord {
  FunctionSignature Signature;
  AccessControl Access;

  CXXMethodRecord() = delete;

  CXXMethodRecord(RecordKind Kind, StringRef USR, StringRef Name,
                  PresumedLoc Loc, AvailabilityInfo Availability,
                  const DocComment &Comment, DeclarationFragments Declaration,
                  DeclarationFragments SubHeading, FunctionSignature Signature,
                  AccessControl Access, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Signature(Signature), Access(Access) {}

  virtual ~CXXMethodRecord() = 0;
};

struct CXXConstructorRecord : CXXMethodRecord {
  CXXConstructorRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                       AvailabilityInfo Availability, const DocComment &Comment,
                       DeclarationFragments Declaration,
                       DeclarationFragments SubHeading,
                       FunctionSignature Signature, AccessControl Access,
                       bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXConstructorMethod, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader) {}
  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXConstructorMethod;
  }

private:
  virtual void anchor();
};

struct CXXDestructorRecord : CXXMethodRecord {
  CXXDestructorRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                      AvailabilityInfo Availability, const DocComment &Comment,
                      DeclarationFragments Declaration,
                      DeclarationFragments SubHeading,
                      FunctionSignature Signature, AccessControl Access,
                      bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXDestructorMethod, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader) {}
  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXDestructorMethod;
  }

private:
  virtual void anchor();
};

struct CXXStaticMethodRecord : CXXMethodRecord {
  CXXStaticMethodRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                        AvailabilityInfo Availability,
                        const DocComment &Comment,
                        DeclarationFragments Declaration,
                        DeclarationFragments SubHeading,
                        FunctionSignature Signature, AccessControl Access,
                        bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXStaticMethod, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader) {}
  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXStaticMethod;
  }

private:
  virtual void anchor();
};

struct CXXInstanceMethodRecord : CXXMethodRecord {
  CXXInstanceMethodRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                          AvailabilityInfo Availability,
                          const DocComment &Comment,
                          DeclarationFragments Declaration,
                          DeclarationFragments SubHeading,
                          FunctionSignature Signature, AccessControl Access,
                          bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXInstanceMethod, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXInstanceMethod;
  }

private:
  virtual void anchor();
};

struct CXXMethodTemplateRecord : CXXMethodRecord {
  Template Templ;

  CXXMethodTemplateRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                          AvailabilityInfo Availability,
                          const DocComment &Comment,
                          DeclarationFragments Declaration,
                          DeclarationFragments SubHeading,
                          FunctionSignature Signature, AccessControl Access,
                          Template Template, bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXMethodTemplate, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXMethodTemplate;
  }
};

struct CXXMethodTemplateSpecializationRecord : CXXMethodRecord {
  CXXMethodTemplateSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access,
      bool IsFromSystemHeader)
      : CXXMethodRecord(RK_CXXMethodTemplateSpecialization, USR, Name, Loc,
                        std::move(Availability), Comment, Declaration,
                        SubHeading, Signature, Access, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_CXXMethodTemplateSpecialization;
  }
};

/// This holds information associated with Objective-C properties.
struct ObjCPropertyRecord : APIRecord {
  /// The attributes associated with an Objective-C property.
  enum AttributeKind : unsigned {
    NoAttr = 0,
    ReadOnly = 1,
    Dynamic = 1 << 2,
  };

  AttributeKind Attributes;
  StringRef GetterName;
  StringRef SetterName;
  bool IsOptional;

  ObjCPropertyRecord(RecordKind Kind, StringRef USR, StringRef Name,
                     PresumedLoc Loc, AvailabilityInfo Availability,
                     const DocComment &Comment,
                     DeclarationFragments Declaration,
                     DeclarationFragments SubHeading, AttributeKind Attributes,
                     StringRef GetterName, StringRef SetterName,
                     bool IsOptional, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Attributes(Attributes), GetterName(GetterName), SetterName(SetterName),
        IsOptional(IsOptional) {}

  bool isReadOnly() const { return Attributes & ReadOnly; }
  bool isDynamic() const { return Attributes & Dynamic; }

  virtual ~ObjCPropertyRecord() = 0;
};

struct ObjCInstancePropertyRecord : ObjCPropertyRecord {
  ObjCInstancePropertyRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                             AvailabilityInfo Availability,
                             const DocComment &Comment,
                             DeclarationFragments Declaration,
                             DeclarationFragments SubHeading,
                             AttributeKind Attributes, StringRef GetterName,
                             StringRef SetterName, bool IsOptional,
                             bool IsFromSystemHeader)
      : ObjCPropertyRecord(RK_ObjCInstanceProperty, USR, Name, Loc,
                           std::move(Availability), Comment, Declaration,
                           SubHeading, Attributes, GetterName, SetterName,
                           IsOptional, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCInstanceProperty;
  }

private:
  virtual void anchor();
};

struct ObjCClassPropertyRecord : ObjCPropertyRecord {
  ObjCClassPropertyRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                          AvailabilityInfo Availability,
                          const DocComment &Comment,
                          DeclarationFragments Declaration,
                          DeclarationFragments SubHeading,
                          AttributeKind Attributes, StringRef GetterName,
                          StringRef SetterName, bool IsOptional,
                          bool IsFromSystemHeader)
      : ObjCPropertyRecord(RK_ObjCClassProperty, USR, Name, Loc,
                           std::move(Availability), Comment, Declaration,
                           SubHeading, Attributes, GetterName, SetterName,
                           IsOptional, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCClassProperty;
  }

private:
  virtual void anchor();
};

/// This holds information associated with Objective-C instance variables.
struct ObjCInstanceVariableRecord : APIRecord {
  using AccessControl = ObjCIvarDecl::AccessControl;
  AccessControl Access;

  ObjCInstanceVariableRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                             AvailabilityInfo Availability,
                             const DocComment &Comment,
                             DeclarationFragments Declaration,
                             DeclarationFragments SubHeading,
                             AccessControl Access, bool IsFromSystemHeader)
      : APIRecord(RK_ObjCIvar, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Access(Access) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCIvar;
  }

private:
  virtual void anchor();
};

/// This holds information associated with Objective-C methods.
struct ObjCMethodRecord : APIRecord {
  FunctionSignature Signature;

  ObjCMethodRecord() = delete;

  ObjCMethodRecord(RecordKind Kind, StringRef USR, StringRef Name,
                   PresumedLoc Loc, AvailabilityInfo Availability,
                   const DocComment &Comment, DeclarationFragments Declaration,
                   DeclarationFragments SubHeading, FunctionSignature Signature,
                   bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Signature(Signature) {}

  virtual ~ObjCMethodRecord() = 0;
};

struct ObjCInstanceMethodRecord : ObjCMethodRecord {
  ObjCInstanceMethodRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                           AvailabilityInfo Availability,
                           const DocComment &Comment,
                           DeclarationFragments Declaration,
                           DeclarationFragments SubHeading,
                           FunctionSignature Signature, bool IsFromSystemHeader)
      : ObjCMethodRecord(RK_ObjCInstanceMethod, USR, Name, Loc,
                         std::move(Availability), Comment, Declaration,
                         SubHeading, Signature, IsFromSystemHeader) {}
  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCInstanceMethod;
  }

private:
  virtual void anchor();
};

struct ObjCClassMethodRecord : ObjCMethodRecord {
  ObjCClassMethodRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                        AvailabilityInfo Availability,
                        const DocComment &Comment,
                        DeclarationFragments Declaration,
                        DeclarationFragments SubHeading,
                        FunctionSignature Signature, bool IsFromSystemHeader)
      : ObjCMethodRecord(RK_ObjCClassMethod, USR, Name, Loc,
                         std::move(Availability), Comment, Declaration,
                         SubHeading, Signature, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCClassMethod;
  }

private:
  virtual void anchor();
};

/// This represents a reference to another symbol that might come from external
/// sources.
struct SymbolReference {
  StringRef Name;
  StringRef USR;

  /// The source project/module/product of the referred symbol.
  StringRef Source;

  SymbolReference() = default;
  SymbolReference(StringRef Name, StringRef USR = "", StringRef Source = "")
      : Name(Name), USR(USR), Source(Source) {}
  SymbolReference(const APIRecord &Record)
      : Name(Record.Name), USR(Record.USR) {}
  SymbolReference(const APIRecord *Record)
      : Name(Record->Name), USR(Record->USR) {}

  /// Determine if this SymbolReference is empty.
  ///
  /// \returns true if and only if all \c Name, \c USR, and \c Source is empty.
  bool empty() const { return Name.empty() && USR.empty() && Source.empty(); }
};

struct StaticFieldRecord : CXXFieldRecord {
  SymbolReference Context;

  StaticFieldRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                    AvailabilityInfo Availability, LinkageInfo Linkage,
                    const DocComment &Comment, DeclarationFragments Declaration,
                    DeclarationFragments SubHeading, SymbolReference Context,
                    AccessControl Access, bool IsFromSystemHeader)
      : CXXFieldRecord(RK_StaticField, USR, Name, Loc, std::move(Availability),
                       Comment, Declaration, SubHeading, Access,
                       IsFromSystemHeader),
        Context(Context) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_StaticField;
  }
};

/// The base representation of an Objective-C container record. Holds common
/// information associated with Objective-C containers.
struct ObjCContainerRecord : APIRecord {
  SmallVector<std::unique_ptr<ObjCMethodRecord>> Methods;
  SmallVector<std::unique_ptr<ObjCPropertyRecord>> Properties;
  SmallVector<std::unique_ptr<ObjCInstanceVariableRecord>> Ivars;
  SmallVector<SymbolReference> Protocols;

  ObjCContainerRecord() = delete;

  ObjCContainerRecord(RecordKind Kind, StringRef USR, StringRef Name,
                      PresumedLoc Loc, AvailabilityInfo Availability,
                      LinkageInfo Linkage, const DocComment &Comment,
                      DeclarationFragments Declaration,
                      DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability), Linkage,
                  Comment, Declaration, SubHeading, IsFromSystemHeader) {}

  virtual ~ObjCContainerRecord() = 0;
};

struct CXXClassRecord : APIRecord {
  SmallVector<std::unique_ptr<CXXFieldRecord>> Fields;
  SmallVector<std::unique_ptr<CXXMethodRecord>> Methods;
  SmallVector<SymbolReference> Bases;
  AccessControl Access;

  CXXClassRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                 AvailabilityInfo Availability, const DocComment &Comment,
                 DeclarationFragments Declaration,
                 DeclarationFragments SubHeading, RecordKind Kind,
                 AccessControl Access, bool IsFromSystemHeader)
      : APIRecord(Kind, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Access(Access) {}

  static bool classof(const APIRecord *Record) {
    return (Record->getKind() == RK_CXXClass);
  }

private:
  virtual void anchor();
};

struct ClassTemplateRecord : CXXClassRecord {
  Template Templ;

  ClassTemplateRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                      AvailabilityInfo Availability, const DocComment &Comment,
                      DeclarationFragments Declaration,
                      DeclarationFragments SubHeading, Template Template,
                      AccessControl Access, bool IsFromSystemHeader)
      : CXXClassRecord(USR, Name, Loc, std::move(Availability), Comment,
                       Declaration, SubHeading, RK_ClassTemplate, Access,
                       IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ClassTemplate;
  }
};

struct ClassTemplateSpecializationRecord : CXXClassRecord {
  ClassTemplateSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      AccessControl Access, bool IsFromSystemHeader)
      : CXXClassRecord(USR, Name, Loc, std::move(Availability), Comment,
                       Declaration, SubHeading, RK_ClassTemplateSpecialization,
                       Access, IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ClassTemplateSpecialization;
  }
};

struct ClassTemplatePartialSpecializationRecord : CXXClassRecord {
  Template Templ;
  ClassTemplatePartialSpecializationRecord(
      StringRef USR, StringRef Name, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      Template Template, AccessControl Access, bool IsFromSystemHeader)
      : CXXClassRecord(USR, Name, Loc, std::move(Availability), Comment,
                       Declaration, SubHeading, RK_ClassTemplateSpecialization,
                       Access, IsFromSystemHeader),
        Templ(Template) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ClassTemplatePartialSpecialization;
  }
};

struct ConceptRecord : APIRecord {
  Template Templ;

  ConceptRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                AvailabilityInfo Availability, const DocComment &Comment,
                DeclarationFragments Declaration,
                DeclarationFragments SubHeading, Template Template,
                bool IsFromSystemHeader)
      : APIRecord(RK_Concept, USR, Name, Loc, std::move(Availability),
                  LinkageInfo::none(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        Templ(Template) {}
};

/// This holds information associated with Objective-C categories.
struct ObjCCategoryRecord : ObjCContainerRecord {
  SymbolReference Interface;
  /// Determine whether the Category is derived from external class interface.
  bool IsFromExternalModule = false;

  ObjCCategoryRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                     AvailabilityInfo Availability, const DocComment &Comment,
                     DeclarationFragments Declaration,
                     DeclarationFragments SubHeading, SymbolReference Interface,
                     bool IsFromSystemHeader)
      : ObjCContainerRecord(RK_ObjCCategory, USR, Name, Loc,
                            std::move(Availability), LinkageInfo::none(),
                            Comment, Declaration, SubHeading,
                            IsFromSystemHeader),
        Interface(Interface) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCCategory;
  }

private:
  virtual void anchor();
};

/// This holds information associated with Objective-C interfaces/classes.
struct ObjCInterfaceRecord : ObjCContainerRecord {
  SymbolReference SuperClass;
  // ObjCCategoryRecord%s are stored in and owned by APISet.
  SmallVector<ObjCCategoryRecord *> Categories;

  ObjCInterfaceRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                      AvailabilityInfo Availability, LinkageInfo Linkage,
                      const DocComment &Comment,
                      DeclarationFragments Declaration,
                      DeclarationFragments SubHeading,
                      SymbolReference SuperClass, bool IsFromSystemHeader)
      : ObjCContainerRecord(RK_ObjCInterface, USR, Name, Loc,
                            std::move(Availability), Linkage, Comment,
                            Declaration, SubHeading, IsFromSystemHeader),
        SuperClass(SuperClass) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCInterface;
  }

private:
  virtual void anchor();
};

/// This holds information associated with Objective-C protocols.
struct ObjCProtocolRecord : ObjCContainerRecord {
  ObjCProtocolRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                     AvailabilityInfo Availability, const DocComment &Comment,
                     DeclarationFragments Declaration,
                     DeclarationFragments SubHeading, bool IsFromSystemHeader)
      : ObjCContainerRecord(RK_ObjCProtocol, USR, Name, Loc,
                            std::move(Availability), LinkageInfo::none(),
                            Comment, Declaration, SubHeading,
                            IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_ObjCProtocol;
  }

private:
  virtual void anchor();
};

/// This holds information associated with macro definitions.
struct MacroDefinitionRecord : APIRecord {
  MacroDefinitionRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                        DeclarationFragments Declaration,
                        DeclarationFragments SubHeading,
                        bool IsFromSystemHeader)
      : APIRecord(RK_MacroDefinition, USR, Name, Loc, AvailabilityInfo(),
                  LinkageInfo(), {}, Declaration, SubHeading,
                  IsFromSystemHeader) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_MacroDefinition;
  }

private:
  virtual void anchor();
};

/// This holds information associated with typedefs.
///
/// Note: Typedefs for anonymous enums and structs typically don't get emitted
/// by the serializers but still get a TypedefRecord. Instead we use the
/// typedef name as a name for the underlying anonymous struct or enum.
struct TypedefRecord : APIRecord {
  SymbolReference UnderlyingType;

  TypedefRecord(StringRef USR, StringRef Name, PresumedLoc Loc,
                AvailabilityInfo Availability, const DocComment &Comment,
                DeclarationFragments Declaration,
                DeclarationFragments SubHeading, SymbolReference UnderlyingType,
                bool IsFromSystemHeader)
      : APIRecord(RK_Typedef, USR, Name, Loc, std::move(Availability),
                  LinkageInfo(), Comment, Declaration, SubHeading,
                  IsFromSystemHeader),
        UnderlyingType(UnderlyingType) {}

  static bool classof(const APIRecord *Record) {
    return Record->getKind() == RK_Typedef;
  }

private:
  virtual void anchor();
};

/// Check if a record type has a function signature mixin.
///
/// This is denoted by the record type having a ``Signature`` field of type
/// FunctionSignature.
template <typename RecordTy>
struct has_function_signature : public std::false_type {};
template <>
struct has_function_signature<GlobalFunctionRecord> : public std::true_type {};
template <>
struct has_function_signature<ObjCMethodRecord> : public std::true_type {};
template <>
struct has_function_signature<ObjCInstanceMethodRecord>
    : public std::true_type {};
template <>
struct has_function_signature<ObjCClassMethodRecord> : public std::true_type {};
template <>
struct has_function_signature<CXXInstanceMethodRecord> : public std::true_type {};
template <>
struct has_function_signature<CXXStaticMethodRecord> : public std::true_type {};
template <>
struct has_function_signature<CXXMethodTemplateRecord> : public std::true_type {
};
template <>
struct has_function_signature<CXXMethodTemplateSpecializationRecord>
    : public std::true_type {};

template <typename RecordTy> struct has_access : public std::false_type {};
template <> struct has_access<CXXInstanceMethodRecord> : public std::true_type {};
template <> struct has_access<CXXStaticMethodRecord> : public std::true_type {};
template <> struct has_access<CXXFieldRecord> : public std::true_type {};
template <>
struct has_access<CXXMethodTemplateRecord> : public std::true_type {};
template <>
struct has_access<CXXMethodTemplateSpecializationRecord>
    : public std::true_type {};
template <>
struct has_access<CXXFieldTemplateRecord> : public std::true_type {};
template <> struct has_access<CXXClassRecord> : public std::true_type {};
template <> struct has_access<ClassTemplateRecord> : public std::true_type {};
template <>
struct has_access<ClassTemplateSpecializationRecord> : public std::true_type {};
template <>
struct has_access<ClassTemplatePartialSpecializationRecord>
    : public std::true_type {};

template <typename RecordTy> struct has_template : public std::false_type {};
template <> struct has_template<ClassTemplateRecord> : public std::true_type {};
template <>
struct has_template<ClassTemplatePartialSpecializationRecord>
    : public std::true_type {};
template <> struct has_template<ConceptRecord> : public std::true_type {};
template <>
struct has_template<GlobalVariableTemplateRecord> : public std::true_type {};
template <>
struct has_template<GlobalVariableTemplatePartialSpecializationRecord>
    : public std::true_type {};
template <>
struct has_template<CXXMethodTemplateRecord> : public std::true_type {};
template <>
struct has_template<CXXFieldTemplateRecord> : public std::true_type {};

template <>
struct has_template<GlobalFunctionTemplateRecord> : public std::true_type {};
template <>
struct has_function_signature<GlobalFunctionTemplateRecord>
    : public std::true_type {};
template <>
struct has_function_signature<GlobalFunctionTemplateSpecializationRecord>
    : public std::true_type {};

/// APISet holds the set of API records collected from given inputs.
class APISet {
public:
  NamespaceRecord *addNamespace(APIRecord *Parent, StringRef Name,
                                StringRef USR, PresumedLoc Loc,
                                AvailabilityInfo Availability,
                                LinkageInfo Linkage, const DocComment &Comment,
                                DeclarationFragments Declaration,
                                DeclarationFragments SubHeading,
                                bool IsFromSystemHeaderg);
  /// Create and add a global variable record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  GlobalVariableRecord *
  addGlobalVar(StringRef Name, StringRef USR, PresumedLoc Loc,
               AvailabilityInfo Availability, LinkageInfo Linkage,
               const DocComment &Comment, DeclarationFragments Declaration,
               DeclarationFragments SubHeadin, bool IsFromSystemHeaderg);

  GlobalVariableTemplateRecord *
  addGlobalVariableTemplate(StringRef Name, StringRef USR, PresumedLoc Loc,
                            AvailabilityInfo Availability, LinkageInfo Linkage,
                            const DocComment &Comment,
                            DeclarationFragments Declaration,
                            DeclarationFragments SubHeading, Template Template,
                            bool IsFromSystemHeader);

  /// Create and add a function record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  GlobalFunctionRecord *
  addGlobalFunction(StringRef Name, StringRef USR, PresumedLoc Loc,
                    AvailabilityInfo Availability, LinkageInfo Linkage,
                    const DocComment &Comment, DeclarationFragments Declaration,
                    DeclarationFragments SubHeading,
                    FunctionSignature Signature, bool IsFromSystemHeader);

  GlobalFunctionTemplateRecord *addGlobalFunctionTemplate(
      StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, FunctionSignature Signature,
      Template Template, bool IsFromSystemHeader);

  GlobalFunctionTemplateSpecializationRecord *
  addGlobalFunctionTemplateSpecialization(
      StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, FunctionSignature Signature,
      bool IsFromSystemHeader);

  /// Create and add an enum constant record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  EnumConstantRecord *
  addEnumConstant(EnumRecord *Enum, StringRef Name, StringRef USR,
                  PresumedLoc Loc, AvailabilityInfo Availability,
                  const DocComment &Comment, DeclarationFragments Declaration,
                  DeclarationFragments SubHeading, bool IsFromSystemHeader);

  /// Create and add an enum record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  EnumRecord *addEnum(StringRef Name, StringRef USR, PresumedLoc Loc,
                      AvailabilityInfo Availability, const DocComment &Comment,
                      DeclarationFragments Declaration,
                      DeclarationFragments SubHeading, bool IsFromSystemHeader);

  /// Create and add a record field record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  RecordFieldRecord *
  addRecordField(RecordRecord *Record, StringRef Name, StringRef USR,
                 PresumedLoc Loc, AvailabilityInfo Availability,
                 const DocComment &Comment, DeclarationFragments Declaration,
                 DeclarationFragments SubHeading, APIRecord::RecordKind Kind,
                 bool IsFromSystemHeader);

  /// Create and add a record record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  RecordRecord *addRecord(StringRef Name, StringRef USR, PresumedLoc Loc,
                          AvailabilityInfo Availability,
                          const DocComment &Comment,
                          DeclarationFragments Declaration,
                          DeclarationFragments SubHeading,
                          APIRecord::RecordKind Kind, bool IsFromSystemHeader);

  StaticFieldRecord *
  addStaticField(StringRef Name, StringRef USR, PresumedLoc Loc,
                 AvailabilityInfo Availability, LinkageInfo Linkage,
                 const DocComment &Comment, DeclarationFragments Declaration,
                 DeclarationFragments SubHeading, SymbolReference Context,
                 AccessControl Access, bool IsFromSystemHeaderg);

  CXXFieldRecord *addCXXField(APIRecord *CXXClass, StringRef Name,
                              StringRef USR, PresumedLoc Loc,
                              AvailabilityInfo Availability,
                              const DocComment &Comment,
                              DeclarationFragments Declaration,
                              DeclarationFragments SubHeading,
                              AccessControl Access, bool IsFromSystemHeader);

  CXXFieldTemplateRecord *addCXXFieldTemplate(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      AccessControl Access, Template Template, bool IsFromSystemHeader);

  CXXClassRecord *addCXXClass(APIRecord *Parent, StringRef Name, StringRef USR,
                              PresumedLoc Loc, AvailabilityInfo Availability,
                              const DocComment &Comment,
                              DeclarationFragments Declaration,
                              DeclarationFragments SubHeading,
                              APIRecord::RecordKind Kind, AccessControl Access,
                              bool IsFromSystemHeader);

  ClassTemplateRecord *
  addClassTemplate(APIRecord *Parent, StringRef Name, StringRef USR,
                   PresumedLoc Loc, AvailabilityInfo Availability,
                   const DocComment &Comment, DeclarationFragments Declaration,
                   DeclarationFragments SubHeading, Template Template,
                   AccessControl Access, bool IsFromSystemHeader);

  ClassTemplateSpecializationRecord *addClassTemplateSpecialization(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      AccessControl Access, bool IsFromSystemHeader);

  ClassTemplatePartialSpecializationRecord *
  addClassTemplatePartialSpecialization(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      Template Template, AccessControl Access, bool IsFromSystemHeader);

  GlobalVariableTemplateSpecializationRecord *
  addGlobalVariableTemplateSpecialization(
      StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, bool IsFromSystemHeader);

  GlobalVariableTemplatePartialSpecializationRecord *
  addGlobalVariableTemplatePartialSpecialization(
      StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, LinkageInfo Linkage,
      const DocComment &Comment, DeclarationFragments Declaration,
      DeclarationFragments SubHeading, Template Template,
      bool IsFromSystemHeader);

  CXXMethodRecord *addCXXInstanceMethod(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access,
      bool IsFromSystemHeader);

  CXXMethodRecord *addCXXStaticMethod(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access,
      bool IsFromSystemHeader);

  CXXMethodRecord *addCXXSpecialMethod(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access,
      bool IsFromSystemHeader);

  CXXMethodTemplateRecord *addCXXMethodTemplate(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access, Template Template,
      bool IsFromSystemHeader);

  CXXMethodTemplateSpecializationRecord *addCXXMethodTemplateSpec(
      APIRecord *Parent, StringRef Name, StringRef USR, PresumedLoc Loc,
      AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      FunctionSignature Signature, AccessControl Access,
      bool IsFromSystemHeader);

  ConceptRecord *addConcept(StringRef Name, StringRef USR, PresumedLoc Loc,
                            AvailabilityInfo Availability,
                            const DocComment &Comment,
                            DeclarationFragments Declaration,
                            DeclarationFragments SubHeading, Template Template,
                            bool IsFromSystemHeader);

  /// Create and add an Objective-C category record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCCategoryRecord *
  addObjCCategory(StringRef Name, StringRef USR, PresumedLoc Loc,
                  AvailabilityInfo Availability, const DocComment &Comment,
                  DeclarationFragments Declaration,
                  DeclarationFragments SubHeading, SymbolReference Interface,
                  bool IsFromSystemHeader, bool IsFromExternalModule);

  /// Create and add an Objective-C interface record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCInterfaceRecord *
  addObjCInterface(StringRef Name, StringRef USR, PresumedLoc Loc,
                   AvailabilityInfo Availability, LinkageInfo Linkage,
                   const DocComment &Comment, DeclarationFragments Declaration,
                   DeclarationFragments SubHeading, SymbolReference SuperClass,
                   bool IsFromSystemHeader);

  /// Create and add an Objective-C method record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCMethodRecord *
  addObjCMethod(ObjCContainerRecord *Container, StringRef Name, StringRef USR,
                PresumedLoc Loc, AvailabilityInfo Availability,
                const DocComment &Comment, DeclarationFragments Declaration,
                DeclarationFragments SubHeading, FunctionSignature Signature,
                bool IsInstanceMethod, bool IsFromSystemHeader);

  /// Create and add an Objective-C property record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCPropertyRecord *
  addObjCProperty(ObjCContainerRecord *Container, StringRef Name, StringRef USR,
                  PresumedLoc Loc, AvailabilityInfo Availability,
                  const DocComment &Comment, DeclarationFragments Declaration,
                  DeclarationFragments SubHeading,
                  ObjCPropertyRecord::AttributeKind Attributes,
                  StringRef GetterName, StringRef SetterName, bool IsOptional,
                  bool IsInstanceProperty, bool IsFromSystemHeader);

  /// Create and add an Objective-C instance variable record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCInstanceVariableRecord *addObjCInstanceVariable(
      ObjCContainerRecord *Container, StringRef Name, StringRef USR,
      PresumedLoc Loc, AvailabilityInfo Availability, const DocComment &Comment,
      DeclarationFragments Declaration, DeclarationFragments SubHeading,
      ObjCInstanceVariableRecord::AccessControl Access,
      bool IsFromSystemHeader);

  /// Create and add an Objective-C protocol record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  ObjCProtocolRecord *
  addObjCProtocol(StringRef Name, StringRef USR, PresumedLoc Loc,
                  AvailabilityInfo Availability, const DocComment &Comment,
                  DeclarationFragments Declaration,
                  DeclarationFragments SubHeading, bool IsFromSystemHeader);

  /// Create a macro definition record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSRForMacro(StringRef Name,
  /// SourceLocation SL, const SourceManager &SM) is a helper method to generate
  /// the USR for the macro and keep it alive in APISet.
  MacroDefinitionRecord *addMacroDefinition(StringRef Name, StringRef USR,
                                            PresumedLoc Loc,
                                            DeclarationFragments Declaration,
                                            DeclarationFragments SubHeading,
                                            bool IsFromSystemHeader);

  /// Create a typedef record into the API set.
  ///
  /// Note: the caller is responsible for keeping the StringRef \p Name and
  /// \p USR alive. APISet::copyString provides a way to copy strings into
  /// APISet itself, and APISet::recordUSR(const Decl *D) is a helper method
  /// to generate the USR for \c D and keep it alive in APISet.
  TypedefRecord *
  addTypedef(StringRef Name, StringRef USR, PresumedLoc Loc,
             AvailabilityInfo Availability, const DocComment &Comment,
             DeclarationFragments Declaration, DeclarationFragments SubHeading,
             SymbolReference UnderlyingType, bool IsFromSystemHeader);

  /// A mapping type to store a set of APIRecord%s with the USR as the key.
  template <typename RecordTy,
            typename =
                std::enable_if_t<std::is_base_of<APIRecord, RecordTy>::value>>
  using RecordMap = llvm::MapVector<StringRef, std::unique_ptr<RecordTy>>;

  /// Get the target triple for the ExtractAPI invocation.
  const llvm::Triple &getTarget() const { return Target; }

  /// Get the language used by the APIs.
  Language getLanguage() const { return Lang; }

  const RecordMap<NamespaceRecord> &getNamespaces() const { return Namespaces; }
  const RecordMap<GlobalFunctionRecord> &getGlobalFunctions() const {
    return GlobalFunctions;
  }
  const RecordMap<GlobalFunctionTemplateRecord> &
  getGlobalFunctionTemplates() const {
    return GlobalFunctionTemplates;
  }
  const RecordMap<GlobalFunctionTemplateSpecializationRecord> &
  getGlobalFunctionTemplateSpecializations() const {
    return GlobalFunctionTemplateSpecializations;
  }
  const RecordMap<GlobalVariableRecord> &getGlobalVariables() const {
    return GlobalVariables;
  }
  const RecordMap<GlobalVariableTemplateRecord> &
  getGlobalVariableTemplates() const {
    return GlobalVariableTemplates;
  }
  const RecordMap<StaticFieldRecord> &getStaticFields() const {
    return StaticFields;
  }
  const RecordMap<GlobalVariableTemplateSpecializationRecord> &
  getGlobalVariableTemplateSpecializations() const {
    return GlobalVariableTemplateSpecializations;
  }
  const RecordMap<GlobalVariableTemplatePartialSpecializationRecord> &
  getGlobalVariableTemplatePartialSpecializations() const {
    return GlobalVariableTemplatePartialSpecializations;
  }
  const RecordMap<EnumRecord> &getEnums() const { return Enums; }
  const RecordMap<RecordRecord> &getRecords() const { return Records; }
  const RecordMap<CXXClassRecord> &getCXXClasses() const { return CXXClasses; }
  const RecordMap<CXXMethodTemplateRecord> &getCXXMethodTemplates() const {
    return CXXMethodTemplates;
  }
  const RecordMap<CXXInstanceMethodRecord> &getCXXInstanceMethods() const {
    return CXXInstanceMethods;
  }
  const RecordMap<CXXStaticMethodRecord> &getCXXStaticMethods() const {
    return CXXStaticMethods;
  }
  const RecordMap<CXXFieldRecord> &getCXXFields() const { return CXXFields; }
  const RecordMap<CXXMethodTemplateSpecializationRecord> &
  getCXXMethodTemplateSpecializations() const {
    return CXXMethodTemplateSpecializations;
  }
  const RecordMap<CXXFieldTemplateRecord> &getCXXFieldTemplates() const {
    return CXXFieldTemplates;
  }
  const RecordMap<ClassTemplateRecord> &getClassTemplates() const {
    return ClassTemplates;
  }
  const RecordMap<ClassTemplateSpecializationRecord> &
  getClassTemplateSpecializations() const {
    return ClassTemplateSpecializations;
  }
  const RecordMap<ClassTemplatePartialSpecializationRecord> &
  getClassTemplatePartialSpecializations() const {
    return ClassTemplatePartialSpecializations;
  }
  const RecordMap<ConceptRecord> &getConcepts() const { return Concepts; }
  const RecordMap<ObjCCategoryRecord> &getObjCCategories() const {
    return ObjCCategories;
  }
  const RecordMap<ObjCInterfaceRecord> &getObjCInterfaces() const {
    return ObjCInterfaces;
  }
  const RecordMap<ObjCProtocolRecord> &getObjCProtocols() const {
    return ObjCProtocols;
  }
  const RecordMap<MacroDefinitionRecord> &getMacros() const { return Macros; }
  const RecordMap<TypedefRecord> &getTypedefs() const { return Typedefs; }

  /// Finds the APIRecord for a given USR.
  ///
  /// \returns a pointer to the APIRecord associated with that USR or nullptr.
  APIRecord *findRecordForUSR(StringRef USR) const;

  /// Generate and store the USR of declaration \p D.
  ///
  /// Note: The USR string is stored in and owned by Allocator.
  ///
  /// \returns a StringRef of the generated USR string.
  StringRef recordUSR(const Decl *D);

  /// Generate and store the USR for a macro \p Name.
  ///
  /// Note: The USR string is stored in and owned by Allocator.
  ///
  /// \returns a StringRef to the generate USR string.
  StringRef recordUSRForMacro(StringRef Name, SourceLocation SL,
                              const SourceManager &SM);

  /// Copy \p String into the Allocator in this APISet.
  ///
  /// \returns a StringRef of the copied string in APISet::Allocator.
  StringRef copyString(StringRef String);

  APISet(const llvm::Triple &Target, Language Lang,
         const std::string &ProductName)
      : Target(Target), Lang(Lang), ProductName(ProductName) {}

private:
  /// BumpPtrAllocator to store generated/copied strings.
  ///
  /// Note: The main use for this is being able to deduplicate strings.
  llvm::BumpPtrAllocator StringAllocator;

  const llvm::Triple Target;
  const Language Lang;

  llvm::DenseMap<StringRef, APIRecord *> USRBasedLookupTable;
  RecordMap<NamespaceRecord> Namespaces;
  RecordMap<GlobalFunctionRecord> GlobalFunctions;
  RecordMap<GlobalFunctionTemplateRecord> GlobalFunctionTemplates;
  RecordMap<GlobalFunctionTemplateSpecializationRecord>
      GlobalFunctionTemplateSpecializations;
  RecordMap<GlobalVariableRecord> GlobalVariables;
  RecordMap<GlobalVariableTemplateRecord> GlobalVariableTemplates;
  RecordMap<GlobalVariableTemplateSpecializationRecord>
      GlobalVariableTemplateSpecializations;
  RecordMap<GlobalVariableTemplatePartialSpecializationRecord>
      GlobalVariableTemplatePartialSpecializations;
  RecordMap<ConceptRecord> Concepts;
  RecordMap<StaticFieldRecord> StaticFields;
  RecordMap<EnumRecord> Enums;
  RecordMap<RecordRecord> Records;
  RecordMap<CXXClassRecord> CXXClasses;
  RecordMap<CXXFieldRecord> CXXFields;
  RecordMap<CXXMethodRecord> CXXMethods;
  RecordMap<CXXInstanceMethodRecord> CXXInstanceMethods;
  RecordMap<CXXStaticMethodRecord> CXXStaticMethods;
  RecordMap<CXXMethodTemplateRecord> CXXMethodTemplates;
  RecordMap<CXXMethodTemplateSpecializationRecord>
      CXXMethodTemplateSpecializations;
  RecordMap<CXXFieldTemplateRecord> CXXFieldTemplates;
  RecordMap<ClassTemplateRecord> ClassTemplates;
  RecordMap<ClassTemplateSpecializationRecord> ClassTemplateSpecializations;
  RecordMap<ClassTemplatePartialSpecializationRecord>
      ClassTemplatePartialSpecializations;
  RecordMap<ObjCCategoryRecord> ObjCCategories;
  RecordMap<ObjCInterfaceRecord> ObjCInterfaces;
  RecordMap<ObjCProtocolRecord> ObjCProtocols;
  RecordMap<MacroDefinitionRecord> Macros;
  RecordMap<TypedefRecord> Typedefs;

public:
  const std::string ProductName;
};

} // namespace extractapi
} // namespace clang

#endif // LLVM_CLANG_EXTRACTAPI_API_H