/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/CodeGen/CGObjCGNU.cpp

Bug Summary

File:	clang/lib/CodeGen/CGObjCGNU.cpp
Warning:	line 2426, column 33 Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGObjCGNU.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/CodeGen -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/CodeGen/CGObjCGNU.cpp

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/lib/CodeGen/CGObjCGNU.cpp

→

1//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This provides Objective-C code generation targeting the GNU runtime.  The
10// class in this file generates structures used by the GNU Objective-C runtime
11// library.  These structures are defined in objc/objc.h and objc/objc-api.h in
12// the GNU runtime distribution.
13//
14//===----------------------------------------------------------------------===//

16#include "CGCXXABI.h"
17#include "CGCleanup.h"
18#include "CGObjCRuntime.h"
19#include "CodeGenFunction.h"
20#include "CodeGenModule.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/Attr.h"
23#include "clang/AST/Decl.h"
24#include "clang/AST/DeclObjC.h"
25#include "clang/AST/RecordLayout.h"
26#include "clang/AST/StmtObjC.h"
27#include "clang/Basic/FileManager.h"
28#include "clang/Basic/SourceManager.h"
29#include "clang/CodeGen/ConstantInitBuilder.h"
30#include "llvm/ADT/SmallVector.h"
31#include "llvm/ADT/StringMap.h"
32#include "llvm/IR/DataLayout.h"
33#include "llvm/IR/Intrinsics.h"
34#include "llvm/IR/LLVMContext.h"
35#include "llvm/IR/Module.h"
36#include "llvm/Support/Compiler.h"
37#include "llvm/Support/ConvertUTF.h"
38#include <cctype>

40using namespace clang;
41using namespace CodeGen;

43namespace {

45/// Class that lazily initialises the runtime function.  Avoids inserting the
46/// types and the function declaration into a module if they're not used, and
47/// avoids constructing the type more than once if it's used more than once.
48class LazyRuntimeFunction {
CodeGenModule *CGM;
llvm::FunctionType *FTy;
const char *FunctionName;
llvm::FunctionCallee Function;

54public:
/// Constructor leaves this class uninitialized, because it is intended to
/// be used as a field in another class and not all of the types that are
/// used as arguments will necessarily be available at construction time.
LazyRuntimeFunction()
    : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}

/// Initialises the lazy function with the name, return type, and the types
/// of the arguments.
template <typename... Tys>
void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy,
          Tys *... Types) {
  CGM = Mod;
  FunctionName = name;
  Function = nullptr;
  if(sizeof...(Tys)) {
    SmallVector<llvm::Type *, 8> ArgTys({Types...});
    FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
  }
  else {
    FTy = llvm::FunctionType::get(RetTy, None, false);
  }
}

llvm::FunctionType *getType() { return FTy; }

/// Overloaded cast operator, allows the class to be implicitly cast to an
/// LLVM constant.
operator llvm::FunctionCallee() {
  if (!Function) {
    if (!FunctionName)
      return nullptr;
    Function = CGM->CreateRuntimeFunction(FTy, FunctionName);
  }
  return Function;
}
90};


93/// GNU Objective-C runtime code generation.  This class implements the parts of
94/// Objective-C support that are specific to the GNU family of runtimes (GCC,
95/// GNUstep and ObjFW).
96class CGObjCGNU : public CGObjCRuntime {
97protected:
/// The LLVM module into which output is inserted
llvm::Module &TheModule;
/// strut objc_super.  Used for sending messages to super.  This structure
/// contains the receiver (object) and the expected class.
llvm::StructType *ObjCSuperTy;
/// struct objc_super*.  The type of the argument to the superclass message
/// lookup functions.
llvm::PointerType *PtrToObjCSuperTy;
/// LLVM type for selectors.  Opaque pointer (i8*) unless a header declaring
/// SEL is included in a header somewhere, in which case it will be whatever
/// type is declared in that header, most likely {i8*, i8*}.
llvm::PointerType *SelectorTy;
/// LLVM i8 type.  Cached here to avoid repeatedly getting it in all of the
/// places where it's used
llvm::IntegerType *Int8Ty;
/// Pointer to i8 - LLVM type of char*, for all of the places where the
/// runtime needs to deal with C strings.
llvm::PointerType *PtrToInt8Ty;
/// struct objc_protocol type
llvm::StructType *ProtocolTy;
/// Protocol * type.
llvm::PointerType *ProtocolPtrTy;
/// Instance Method Pointer type.  This is a pointer to a function that takes,
/// at a minimum, an object and a selector, and is the generic type for
/// Objective-C methods.  Due to differences between variadic / non-variadic
/// calling conventions, it must always be cast to the correct type before
/// actually being used.
llvm::PointerType *IMPTy;
/// Type of an untyped Objective-C object.  Clang treats id as a built-in type
/// when compiling Objective-C code, so this may be an opaque pointer (i8*),
/// but if the runtime header declaring it is included then it may be a
/// pointer to a structure.
llvm::PointerType *IdTy;
/// Pointer to a pointer to an Objective-C object.  Used in the new ABI
/// message lookup function and some GC-related functions.
llvm::PointerType *PtrToIdTy;
/// The clang type of id.  Used when using the clang CGCall infrastructure to
/// call Objective-C methods.
CanQualType ASTIdTy;
/// LLVM type for C int type.
llvm::IntegerType *IntTy;
/// LLVM type for an opaque pointer.  This is identical to PtrToInt8Ty, but is
/// used in the code to document the difference between i8* meaning a pointer
/// to a C string and i8* meaning a pointer to some opaque type.
llvm::PointerType *PtrTy;
/// LLVM type for C long type.  The runtime uses this in a lot of places where
/// it should be using intptr_t, but we can't fix this without breaking
/// compatibility with GCC...
llvm::IntegerType *LongTy;
/// LLVM type for C size_t.  Used in various runtime data structures.
llvm::IntegerType *SizeTy;
/// LLVM type for C intptr_t.
llvm::IntegerType *IntPtrTy;
/// LLVM type for C ptrdiff_t.  Mainly used in property accessor functions.
llvm::IntegerType *PtrDiffTy;
/// LLVM type for C int*.  Used for GCC-ABI-compatible non-fragile instance
/// variables.
llvm::PointerType *PtrToIntTy;
/// LLVM type for Objective-C BOOL type.
llvm::Type *BoolTy;
/// 32-bit integer type, to save us needing to look it up every time it's used.
llvm::IntegerType *Int32Ty;
/// 64-bit integer type, to save us needing to look it up every time it's used.
llvm::IntegerType *Int64Ty;
/// The type of struct objc_property.
llvm::StructType *PropertyMetadataTy;
/// Metadata kind used to tie method lookups to message sends.  The GNUstep
/// runtime provides some LLVM passes that can use this to do things like
/// automatic IMP caching and speculative inlining.
unsigned msgSendMDKind;
/// Does the current target use SEH-based exceptions? False implies
/// Itanium-style DWARF unwinding.
bool usesSEHExceptions;

/// Helper to check if we are targeting a specific runtime version or later.
bool isRuntime(ObjCRuntime::Kind kind, unsigned major, unsigned minor=0) {
  const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
  return (R.getKind() == kind) &&
    (R.getVersion() >= VersionTuple(major, minor));
}

std::string ManglePublicSymbol(StringRef Name) {
  return (StringRef(CGM.getTriple().isOSBinFormatCOFF() ? "$_" : "._") + Name).str();
}

std::string SymbolForProtocol(Twine Name) {
  return (ManglePublicSymbol("OBJC_PROTOCOL_") + Name).str();
}

std::string SymbolForProtocolRef(StringRef Name) {
  return (ManglePublicSymbol("OBJC_REF_PROTOCOL_") + Name).str();
}


/// Helper function that generates a constant string and returns a pointer to
/// the start of the string.  The result of this function can be used anywhere
/// where the C code specifies const char*.
llvm::Constant *MakeConstantString(StringRef Str, const char *Name = "") {
  ConstantAddress Array =
      CGM.GetAddrOfConstantCString(std::string(Str), Name);
  return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
                                              Array.getPointer(), Zeros);
}

/// Emits a linkonce_odr string, whose name is the prefix followed by the
/// string value.  This allows the linker to combine the strings between
/// different modules.  Used for EH typeinfo names, selector strings, and a
/// few other things.
llvm::Constant *ExportUniqueString(const std::string &Str,
                                   const std::string &prefix,
                                   bool Private=false) {
  std::string name = prefix + Str;
  auto *ConstStr = TheModule.getGlobalVariable(name);
  if (!ConstStr) {
    llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
    auto *GV = new llvm::GlobalVariable(TheModule, value->getType(), true,
            llvm::GlobalValue::LinkOnceODRLinkage, value, name);
    GV->setComdat(TheModule.getOrInsertComdat(name));
    if (Private)
      GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
    ConstStr = GV;
  }
  return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
                                              ConstStr, Zeros);
}

/// Returns a property name and encoding string.
llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
                                           const Decl *Container) {
  assert(!isRuntime(ObjCRuntime::GNUstep, 2))(static_cast<void> (0));
  if (isRuntime(ObjCRuntime::GNUstep, 1, 6)) {
    std::string NameAndAttributes;
    std::string TypeStr =
      CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container);
    NameAndAttributes += '\0';
    NameAndAttributes += TypeStr.length() + 3;
    NameAndAttributes += TypeStr;
    NameAndAttributes += '\0';
    NameAndAttributes += PD->getNameAsString();
    return MakeConstantString(NameAndAttributes);
  }
  return MakeConstantString(PD->getNameAsString());
}

/// Push the property attributes into two structure fields.
void PushPropertyAttributes(ConstantStructBuilder &Fields,
    const ObjCPropertyDecl *property, bool isSynthesized=true, bool
    isDynamic=true) {
  int attrs = property->getPropertyAttributes();
  // For read-only properties, clear the copy and retain flags
  if (attrs & ObjCPropertyAttribute::kind_readonly) {
    attrs &= ~ObjCPropertyAttribute::kind_copy;
    attrs &= ~ObjCPropertyAttribute::kind_retain;
    attrs &= ~ObjCPropertyAttribute::kind_weak;
    attrs &= ~ObjCPropertyAttribute::kind_strong;
  }
  // The first flags field has the same attribute values as clang uses internally
  Fields.addInt(Int8Ty, attrs & 0xff);
  attrs >>= 8;
  attrs <<= 2;
  // For protocol properties, synthesized and dynamic have no meaning, so we
  // reuse these flags to indicate that this is a protocol property (both set
  // has no meaning, as a property can't be both synthesized and dynamic)
  attrs |= isSynthesized ? (1<<0) : 0;
  attrs |= isDynamic ? (1<<1) : 0;
  // The second field is the next four fields left shifted by two, with the
  // low bit set to indicate whether the field is synthesized or dynamic.
  Fields.addInt(Int8Ty, attrs & 0xff);
  // Two padding fields
  Fields.addInt(Int8Ty, 0);
  Fields.addInt(Int8Ty, 0);
}

virtual llvm::Constant *GenerateCategoryProtocolList(const
    ObjCCategoryDecl *OCD);
virtual ConstantArrayBuilder PushPropertyListHeader(ConstantStructBuilder &Fields,
    int count) {
    // int count;
    Fields.addInt(IntTy, count);
    // int size; (only in GNUstep v2 ABI.
    if (isRuntime(ObjCRuntime::GNUstep, 2)) {
      llvm::DataLayout td(&TheModule);
      Fields.addInt(IntTy, td.getTypeSizeInBits(PropertyMetadataTy) /
          CGM.getContext().getCharWidth());
    }
    // struct objc_property_list *next;
    Fields.add(NULLPtr);
    // struct objc_property properties[]
    return Fields.beginArray(PropertyMetadataTy);
}
virtual void PushProperty(ConstantArrayBuilder &PropertiesArray,
          const ObjCPropertyDecl *property,
          const Decl *OCD,
          bool isSynthesized=true, bool
          isDynamic=true) {
  auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
  ASTContext &Context = CGM.getContext();
  Fields.add(MakePropertyEncodingString(property, OCD));
  PushPropertyAttributes(Fields, property, isSynthesized, isDynamic);
  auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
    if (accessor) {
      std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
      llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
      Fields.add(MakeConstantString(accessor->getSelector().getAsString()));
      Fields.add(TypeEncoding);
    } else {
      Fields.add(NULLPtr);
      Fields.add(NULLPtr);
    }
  };
  addPropertyMethod(property->getGetterMethodDecl());
  addPropertyMethod(property->getSetterMethodDecl());
  Fields.finishAndAddTo(PropertiesArray);
}

/// Ensures that the value has the required type, by inserting a bitcast if
/// required.  This function lets us avoid inserting bitcasts that are
/// redundant.
llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
  if (V->getType() == Ty) return V;
  return B.CreateBitCast(V, Ty);
}
Address EnforceType(CGBuilderTy &B, Address V, llvm::Type *Ty) {
  if (V.getType() == Ty) return V;
  return B.CreateBitCast(V, Ty);
}

// Some zeros used for GEPs in lots of places.
llvm::Constant *Zeros[2];
/// Null pointer value.  Mainly used as a terminator in various arrays.
llvm::Constant *NULLPtr;
/// LLVM context.
llvm::LLVMContext &VMContext;

332protected:

/// Placeholder for the class.  Lots of things refer to the class before we've
/// actually emitted it.  We use this alias as a placeholder, and then replace
/// it with a pointer to the class structure before finally emitting the
/// module.
llvm::GlobalAlias *ClassPtrAlias;
/// Placeholder for the metaclass.  Lots of things refer to the class before
/// we've / actually emitted it.  We use this alias as a placeholder, and then
/// replace / it with a pointer to the metaclass structure before finally
/// emitting the / module.
llvm::GlobalAlias *MetaClassPtrAlias;
/// All of the classes that have been generated for this compilation units.
std::vector<llvm::Constant*> Classes;
/// All of the categories that have been generated for this compilation units.
std::vector<llvm::Constant*> Categories;
/// All of the Objective-C constant strings that have been generated for this
/// compilation units.
std::vector<llvm::Constant*> ConstantStrings;
/// Map from string values to Objective-C constant strings in the output.
/// Used to prevent emitting Objective-C strings more than once.  This should
/// not be required at all - CodeGenModule should manage this list.
llvm::StringMap<llvm::Constant*> ObjCStrings;
/// All of the protocols that have been declared.
llvm::StringMap<llvm::Constant*> ExistingProtocols;
/// For each variant of a selector, we store the type encoding and a
/// placeholder value.  For an untyped selector, the type will be the empty
/// string.  Selector references are all done via the module's selector table,
/// so we create an alias as a placeholder and then replace it with the real
/// value later.
typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
/// Type of the selector map.  This is roughly equivalent to the structure
/// used in the GNUstep runtime, which maintains a list of all of the valid
/// types for a selector in a table.
typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
  SelectorMap;
/// A map from selectors to selector types.  This allows us to emit all
/// selectors of the same name and type together.
SelectorMap SelectorTable;

/// Selectors related to memory management.  When compiling in GC mode, we
/// omit these.
Selector RetainSel, ReleaseSel, AutoreleaseSel;
/// Runtime functions used for memory management in GC mode.  Note that clang
/// supports code generation for calling these functions, but neither GNU
/// runtime actually supports this API properly yet.
LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
  WeakAssignFn, GlobalAssignFn;

typedef std::pair<std::string, std::string> ClassAliasPair;
/// All classes that have aliases set for them.
std::vector<ClassAliasPair> ClassAliases;

385protected:
/// Function used for throwing Objective-C exceptions.
LazyRuntimeFunction ExceptionThrowFn;
/// Function used for rethrowing exceptions, used at the end of \@finally or
/// \@synchronize blocks.
LazyRuntimeFunction ExceptionReThrowFn;
/// Function called when entering a catch function.  This is required for
/// differentiating Objective-C exceptions and foreign exceptions.
LazyRuntimeFunction EnterCatchFn;
/// Function called when exiting from a catch block.  Used to do exception
/// cleanup.
LazyRuntimeFunction ExitCatchFn;
/// Function called when entering an \@synchronize block.  Acquires the lock.
LazyRuntimeFunction SyncEnterFn;
/// Function called when exiting an \@synchronize block.  Releases the lock.
LazyRuntimeFunction SyncExitFn;

402private:
/// Function called if fast enumeration detects that the collection is
/// modified during the update.
LazyRuntimeFunction EnumerationMutationFn;
/// Function for implementing synthesized property getters that return an
/// object.
LazyRuntimeFunction GetPropertyFn;
/// Function for implementing synthesized property setters that return an
/// object.
LazyRuntimeFunction SetPropertyFn;
/// Function used for non-object declared property getters.
LazyRuntimeFunction GetStructPropertyFn;
/// Function used for non-object declared property setters.
LazyRuntimeFunction SetStructPropertyFn;

417protected:
/// The version of the runtime that this class targets.  Must match the
/// version in the runtime.
int RuntimeVersion;
/// The version of the protocol class.  Used to differentiate between ObjC1
/// and ObjC2 protocols.  Objective-C 1 protocols can not contain optional
/// components and can not contain declared properties.  We always emit
/// Objective-C 2 property structures, but we have to pretend that they're
/// Objective-C 1 property structures when targeting the GCC runtime or it
/// will abort.
const int ProtocolVersion;
/// The version of the class ABI.  This value is used in the class structure
/// and indicates how various fields should be interpreted.
const int ClassABIVersion;
/// Generates an instance variable list structure.  This is a structure
/// containing a size and an array of structures containing instance variable
/// metadata.  This is used purely for introspection in the fragile ABI.  In
/// the non-fragile ABI, it's used for instance variable fixup.
virtual llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
                           ArrayRef<llvm::Constant *> IvarTypes,
                           ArrayRef<llvm::Constant *> IvarOffsets,
                           ArrayRef<llvm::Constant *> IvarAlign,
                           ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership);

/// Generates a method list structure.  This is a structure containing a size
/// and an array of structures containing method metadata.
///
/// This structure is used by both classes and categories, and contains a next
/// pointer allowing them to be chained together in a linked list.
llvm::Constant *GenerateMethodList(StringRef ClassName,
    StringRef CategoryName,
    ArrayRef<const ObjCMethodDecl*> Methods,
    bool isClassMethodList);

/// Emits an empty protocol.  This is used for \@protocol() where no protocol
/// is found.  The runtime will (hopefully) fix up the pointer to refer to the
/// real protocol.
virtual llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName);

/// Generates a list of property metadata structures.  This follows the same
/// pattern as method and instance variable metadata lists.
llvm::Constant *GeneratePropertyList(const Decl *Container,
    const ObjCContainerDecl *OCD,
    bool isClassProperty=false,
    bool protocolOptionalProperties=false);

/// Generates a list of referenced protocols.  Classes, categories, and
/// protocols all use this structure.
llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);

/// To ensure that all protocols are seen by the runtime, we add a category on
/// a class defined in the runtime, declaring no methods, but adopting the
/// protocols.  This is a horribly ugly hack, but it allows us to collect all
/// of the protocols without changing the ABI.
void GenerateProtocolHolderCategory();

/// Generates a class structure.
llvm::Constant *GenerateClassStructure(
    llvm::Constant *MetaClass,
    llvm::Constant *SuperClass,
    unsigned info,
    const char *Name,
    llvm::Constant *Version,
    llvm::Constant *InstanceSize,
    llvm::Constant *IVars,
    llvm::Constant *Methods,
    llvm::Constant *Protocols,
    llvm::Constant *IvarOffsets,
    llvm::Constant *Properties,
    llvm::Constant *StrongIvarBitmap,
    llvm::Constant *WeakIvarBitmap,
    bool isMeta=false);

/// Generates a method list.  This is used by protocols to define the required
/// and optional methods.
virtual llvm::Constant *GenerateProtocolMethodList(
    ArrayRef<const ObjCMethodDecl*> Methods);
/// Emits optional and required method lists.
template<class T>
void EmitProtocolMethodList(T &&Methods, llvm::Constant *&Required,
    llvm::Constant *&Optional) {
  SmallVector<const ObjCMethodDecl*, 16> RequiredMethods;
  SmallVector<const ObjCMethodDecl*, 16> OptionalMethods;
  for (const auto *I : Methods)
    if (I->isOptional())
      OptionalMethods.push_back(I);
    else
      RequiredMethods.push_back(I);
  Required = GenerateProtocolMethodList(RequiredMethods);
  Optional = GenerateProtocolMethodList(OptionalMethods);
}

/// Returns a selector with the specified type encoding.  An empty string is
/// used to return an untyped selector (with the types field set to NULL).
virtual llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
                                      const std::string &TypeEncoding);

/// Returns the name of ivar offset variables.  In the GNUstep v1 ABI, this
/// contains the class and ivar names, in the v2 ABI this contains the type
/// encoding as well.
virtual std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
                                              const ObjCIvarDecl *Ivar) {
  const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
    + '.' + Ivar->getNameAsString();
  return Name;
}
/// Returns the variable used to store the offset of an instance variable.
llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
    const ObjCIvarDecl *Ivar);
/// Emits a reference to a class.  This allows the linker to object if there
/// is no class of the matching name.
void EmitClassRef(const std::string &className);

/// Emits a pointer to the named class
virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
                                   const std::string &Name, bool isWeak);

/// Looks up the method for sending a message to the specified object.  This
/// mechanism differs between the GCC and GNU runtimes, so this method must be
/// overridden in subclasses.
virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
                               llvm::Value *&Receiver,
                               llvm::Value *cmd,
                               llvm::MDNode *node,
                               MessageSendInfo &MSI) = 0;

/// Looks up the method for sending a message to a superclass.  This
/// mechanism differs between the GCC and GNU runtimes, so this method must
/// be overridden in subclasses.
virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
                                    Address ObjCSuper,
                                    llvm::Value *cmd,
                                    MessageSendInfo &MSI) = 0;

/// Libobjc2 uses a bitfield representation where small(ish) bitfields are
/// stored in a 64-bit value with the low bit set to 1 and the remaining 63
/// bits set to their values, LSB first, while larger ones are stored in a
/// structure of this / form:
///
/// struct { int32_t length; int32_t values[length]; };
///
/// The values in the array are stored in host-endian format, with the least
/// significant bit being assumed to come first in the bitfield.  Therefore,
/// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
/// while a bitfield / with the 63rd bit set will be 1<<64.
llvm::Constant *MakeBitField(ArrayRef<bool> bits);

564public:
CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
    unsigned protocolClassVersion, unsigned classABI=1);

ConstantAddress GenerateConstantString(const StringLiteral *) override;

RValue
GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
                    QualType ResultType, Selector Sel,
                    llvm::Value *Receiver, const CallArgList &CallArgs,
                    const ObjCInterfaceDecl *Class,
                    const ObjCMethodDecl *Method) override;
RValue
GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
                         QualType ResultType, Selector Sel,
                         const ObjCInterfaceDecl *Class,
                         bool isCategoryImpl, llvm::Value *Receiver,
                         bool IsClassMessage, const CallArgList &CallArgs,
                         const ObjCMethodDecl *Method) override;
llvm::Value *GetClass(CodeGenFunction &CGF,
                      const ObjCInterfaceDecl *OID) override;
llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override;
Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override;
llvm::Value *GetSelector(CodeGenFunction &CGF,
                         const ObjCMethodDecl *Method) override;
virtual llvm::Constant *GetConstantSelector(Selector Sel,
                                            const std::string &TypeEncoding) {
  llvm_unreachable("Runtime unable to generate constant selector")__builtin_unreachable();
}
llvm::Constant *GetConstantSelector(const ObjCMethodDecl *M) {
  return GetConstantSelector(M->getSelector(),
      CGM.getContext().getObjCEncodingForMethodDecl(M));
}
llvm::Constant *GetEHType(QualType T) override;

llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
                               const ObjCContainerDecl *CD) override;
void GenerateDirectMethodPrologue(CodeGenFunction &CGF, llvm::Function *Fn,
                                  const ObjCMethodDecl *OMD,
                                  const ObjCContainerDecl *CD) override;
void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
                                 const ObjCProtocolDecl *PD) override;
void GenerateProtocol(const ObjCProtocolDecl *PD) override;

virtual llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD);

llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) override {
  return GenerateProtocolRef(PD);
}

llvm::Function *ModuleInitFunction() override;
llvm::FunctionCallee GetPropertyGetFunction() override;
llvm::FunctionCallee GetPropertySetFunction() override;
llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
                                                     bool copy) override;
llvm::FunctionCallee GetSetStructFunction() override;
llvm::FunctionCallee GetGetStructFunction() override;
llvm::FunctionCallee GetCppAtomicObjectGetFunction() override;
llvm::FunctionCallee GetCppAtomicObjectSetFunction() override;
llvm::FunctionCallee EnumerationMutationFunction() override;

void EmitTryStmt(CodeGenFunction &CGF,
                 const ObjCAtTryStmt &S) override;
void EmitSynchronizedStmt(CodeGenFunction &CGF,
                          const ObjCAtSynchronizedStmt &S) override;
void EmitThrowStmt(CodeGenFunction &CGF,
                   const ObjCAtThrowStmt &S,
                   bool ClearInsertionPoint=true) override;
llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
                               Address AddrWeakObj) override;
void EmitObjCWeakAssign(CodeGenFunction &CGF,
                        llvm::Value *src, Address dst) override;
void EmitObjCGlobalAssign(CodeGenFunction &CGF,
                          llvm::Value *src, Address dest,
                          bool threadlocal=false) override;
void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
                        Address dest, llvm::Value *ivarOffset) override;
void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
                              llvm::Value *src, Address dest) override;
void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr,
                              Address SrcPtr,
                              llvm::Value *Size) override;
LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
                            llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
                            unsigned CVRQualifiers) override;
llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
                            const ObjCInterfaceDecl *Interface,
                            const ObjCIvarDecl *Ivar) override;
llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
                                   const CGBlockInfo &blockInfo) override {
  return NULLPtr;
}
llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
                                   const CGBlockInfo &blockInfo) override {
  return NULLPtr;
}

llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
  return NULLPtr;
}
668};

670/// Class representing the legacy GCC Objective-C ABI.  This is the default when
671/// -fobjc-nonfragile-abi is not specified.
672///
673/// The GCC ABI target actually generates code that is approximately compatible
674/// with the new GNUstep runtime ABI, but refrains from using any features that
675/// would not work with the GCC runtime.  For example, clang always generates
676/// the extended form of the class structure, and the extra fields are simply
677/// ignored by GCC libobjc.
678class CGObjCGCC : public CGObjCGNU {
/// The GCC ABI message lookup function.  Returns an IMP pointing to the
/// method implementation for this message.
LazyRuntimeFunction MsgLookupFn;
/// The GCC ABI superclass message lookup function.  Takes a pointer to a
/// structure describing the receiver and the class, and a selector as
/// arguments.  Returns the IMP for the corresponding method.
LazyRuntimeFunction MsgLookupSuperFn;

687protected:
llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
                       llvm::Value *cmd, llvm::MDNode *node,
                       MessageSendInfo &MSI) override {
  CGBuilderTy &Builder = CGF.Builder;
  llvm::Value *args[] = {
          EnforceType(Builder, Receiver, IdTy),
          EnforceType(Builder, cmd, SelectorTy) };
  llvm::CallBase *imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
  imp->setMetadata(msgSendMDKind, node);
  return imp;
}

llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                            llvm::Value *cmd, MessageSendInfo &MSI) override {
  CGBuilderTy &Builder = CGF.Builder;
  llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
      PtrToObjCSuperTy).getPointer(), cmd};
  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
}

708public:
CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
  // IMP objc_msg_lookup(id, SEL);
  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
                        PtrToObjCSuperTy, SelectorTy);
}
716};

718/// Class used when targeting the new GNUstep runtime ABI.
719class CGObjCGNUstep : public CGObjCGNU {
  /// The slot lookup function.  Returns a pointer to a cacheable structure
  /// that contains (among other things) the IMP.
  LazyRuntimeFunction SlotLookupFn;
  /// The GNUstep ABI superclass message lookup function.  Takes a pointer to
  /// a structure describing the receiver and the class, and a selector as
  /// arguments.  Returns the slot for the corresponding method.  Superclass
  /// message lookup rarely changes, so this is a good caching opportunity.
  LazyRuntimeFunction SlotLookupSuperFn;
  /// Specialised function for setting atomic retain properties
  LazyRuntimeFunction SetPropertyAtomic;
  /// Specialised function for setting atomic copy properties
  LazyRuntimeFunction SetPropertyAtomicCopy;
  /// Specialised function for setting nonatomic retain properties
  LazyRuntimeFunction SetPropertyNonAtomic;
  /// Specialised function for setting nonatomic copy properties
  LazyRuntimeFunction SetPropertyNonAtomicCopy;
  /// Function to perform atomic copies of C++ objects with nontrivial copy
  /// constructors from Objective-C ivars.
  LazyRuntimeFunction CxxAtomicObjectGetFn;
  /// Function to perform atomic copies of C++ objects with nontrivial copy
  /// constructors to Objective-C ivars.
  LazyRuntimeFunction CxxAtomicObjectSetFn;
  /// Type of a slot structure pointer.  This is returned by the various
  /// lookup functions.
  llvm::Type *SlotTy;
  /// Type of a slot structure.
  llvm::Type *SlotStructTy;

public:
  llvm::Constant *GetEHType(QualType T) override;

protected:
  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
                         llvm::Value *cmd, llvm::MDNode *node,
                         MessageSendInfo &MSI) override {
    CGBuilderTy &Builder = CGF.Builder;
    llvm::FunctionCallee LookupFn = SlotLookupFn;

    // Store the receiver on the stack so that we can reload it later
    Address ReceiverPtr =
      CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign());
    Builder.CreateStore(Receiver, ReceiverPtr);

    llvm::Value *self;

    if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
      self = CGF.LoadObjCSelf();
    } else {
      self = llvm::ConstantPointerNull::get(IdTy);
    }

    // The lookup function is guaranteed not to capture the receiver pointer.
    if (auto *LookupFn2 = dyn_cast<llvm::Function>(LookupFn.getCallee()))
      LookupFn2->addParamAttr(0, llvm::Attribute::NoCapture);

    llvm::Value *args[] = {
            EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy),
            EnforceType(Builder, cmd, SelectorTy),
            EnforceType(Builder, self, IdTy) };
    llvm::CallBase *slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
    slot->setOnlyReadsMemory();
    slot->setMetadata(msgSendMDKind, node);

    // Load the imp from the slot
    llvm::Value *imp = Builder.CreateAlignedLoad(
        IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
        CGF.getPointerAlign());

    // The lookup function may have changed the receiver, so make sure we use
    // the new one.
    Receiver = Builder.CreateLoad(ReceiverPtr, true);
    return imp;
  }

  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                              llvm::Value *cmd,
                              MessageSendInfo &MSI) override {
    CGBuilderTy &Builder = CGF.Builder;
    llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd};

    llvm::CallInst *slot =
      CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
    slot->setOnlyReadsMemory();

    return Builder.CreateAlignedLoad(
        IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
        CGF.getPointerAlign());
  }

public:
  CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 9, 3, 1) {}
  CGObjCGNUstep(CodeGenModule &Mod, unsigned ABI, unsigned ProtocolABI,
      unsigned ClassABI) :
    CGObjCGNU(Mod, ABI, ProtocolABI, ClassABI) {
    const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;

    SlotStructTy = llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
    SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
    // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
    SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
                      SelectorTy, IdTy);
    // Slot_t objc_slot_lookup_super(struct objc_super*, SEL);
    SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
                           PtrToObjCSuperTy, SelectorTy);
    // If we're in ObjC++ mode, then we want to make
    if (usesSEHExceptions) {
        llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
        // void objc_exception_rethrow(void)
        ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
    } else if (CGM.getLangOpts().CPlusPlus) {
      llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
      // void *__cxa_begin_catch(void *e)
      EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
      // void __cxa_end_catch(void)
      ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
      // void _Unwind_Resume_or_Rethrow(void*)
      ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
                              PtrTy);
    } else if (R.getVersion() >= VersionTuple(1, 7)) {
      llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
      // id objc_begin_catch(void *e)
      EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
      // void objc_end_catch(void)
      ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
      // void _Unwind_Resume_or_Rethrow(void*)
      ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
    }
    llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
    SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
                           SelectorTy, IdTy, PtrDiffTy);
    SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
                               IdTy, SelectorTy, IdTy, PtrDiffTy);
    SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
                              IdTy, SelectorTy, IdTy, PtrDiffTy);
    SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
                                  VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy);
    // void objc_setCppObjectAtomic(void *dest, const void *src, void
    // *helper);
    CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
                              PtrTy, PtrTy);
    // void objc_getCppObjectAtomic(void *dest, const void *src, void
    // *helper);
    CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
                              PtrTy, PtrTy);
  }

  llvm::FunctionCallee GetCppAtomicObjectGetFunction() override {
    // The optimised functions were added in version 1.7 of the GNUstep
    // runtime.
    assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=(static_cast<void> (0))
        VersionTuple(1, 7))(static_cast<void> (0));
    return CxxAtomicObjectGetFn;
  }

  llvm::FunctionCallee GetCppAtomicObjectSetFunction() override {
    // The optimised functions were added in version 1.7 of the GNUstep
    // runtime.
    assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=(static_cast<void> (0))
        VersionTuple(1, 7))(static_cast<void> (0));
    return CxxAtomicObjectSetFn;
  }

  llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
                                                       bool copy) override {
    // The optimised property functions omit the GC check, and so are not
    // safe to use in GC mode.  The standard functions are fast in GC mode,
    // so there is less advantage in using them.
    assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC))(static_cast<void> (0));
    // The optimised functions were added in version 1.7 of the GNUstep
    // runtime.
    assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=(static_cast<void> (0))
        VersionTuple(1, 7))(static_cast<void> (0));

    if (atomic) {
      if (copy) return SetPropertyAtomicCopy;
      return SetPropertyAtomic;
    }

    return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
  }
900};

902/// GNUstep Objective-C ABI version 2 implementation.
903/// This is the ABI that provides a clean break with the legacy GCC ABI and
904/// cleans up a number of things that were added to work around 1980s linkers.
905class CGObjCGNUstep2 : public CGObjCGNUstep {
enum SectionKind
{
  SelectorSection = 0,
  ClassSection,
  ClassReferenceSection,
  CategorySection,
  ProtocolSection,
  ProtocolReferenceSection,
  ClassAliasSection,
  ConstantStringSection
};
static const char *const SectionsBaseNames[8];
static const char *const PECOFFSectionsBaseNames[8];
template<SectionKind K>
std::string sectionName() {
  if (CGM.getTriple().isOSBinFormatCOFF()) {
    std::string name(PECOFFSectionsBaseNames[K]);
    name += "$m";
    return name;
  }
  return SectionsBaseNames[K];
}
/// The GCC ABI superclass message lookup function.  Takes a pointer to a
/// structure describing the receiver and the class, and a selector as
/// arguments.  Returns the IMP for the corresponding method.
LazyRuntimeFunction MsgLookupSuperFn;
/// A flag indicating if we've emitted at least one protocol.
/// If we haven't, then we need to emit an empty protocol, to ensure that the
/// __start__objc_protocols and __stop__objc_protocols sections exist.
bool EmittedProtocol = false;
/// A flag indicating if we've emitted at least one protocol reference.
/// If we haven't, then we need to emit an empty protocol, to ensure that the
/// __start__objc_protocol_refs and __stop__objc_protocol_refs sections
/// exist.
bool EmittedProtocolRef = false;
/// A flag indicating if we've emitted at least one class.
/// If we haven't, then we need to emit an empty protocol, to ensure that the
/// __start__objc_classes and __stop__objc_classes sections / exist.
bool EmittedClass = false;
/// Generate the name of a symbol for a reference to a class.  Accesses to
/// classes should be indirected via this.

typedef std::pair<std::string, std::pair<llvm::GlobalVariable*, int>>
    EarlyInitPair;
std::vector<EarlyInitPair> EarlyInitList;

std::string SymbolForClassRef(StringRef Name, bool isWeak) {
  if (isWeak)
    return (ManglePublicSymbol("OBJC_WEAK_REF_CLASS_") + Name).str();
  else
    return (ManglePublicSymbol("OBJC_REF_CLASS_") + Name).str();
}
/// Generate the name of a class symbol.
std::string SymbolForClass(StringRef Name) {
  return (ManglePublicSymbol("OBJC_CLASS_") + Name).str();
}
void CallRuntimeFunction(CGBuilderTy &B, StringRef FunctionName,
    ArrayRef<llvm::Value*> Args) {
  SmallVector<llvm::Type *,8> Types;
  for (auto *Arg : Args)
    Types.push_back(Arg->getType());
  llvm::FunctionType *FT = llvm::FunctionType::get(B.getVoidTy(), Types,
      false);
  llvm::FunctionCallee Fn = CGM.CreateRuntimeFunction(FT, FunctionName);
  B.CreateCall(Fn, Args);
}

ConstantAddress GenerateConstantString(const StringLiteral *SL) override {

  auto Str = SL->getString();
  CharUnits Align = CGM.getPointerAlign();

  // Look for an existing one
  llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
  if (old != ObjCStrings.end())
    return ConstantAddress(old->getValue(), Align);

  bool isNonASCII = SL->containsNonAscii();

  auto LiteralLength = SL->getLength();

  if ((CGM.getTarget().getPointerWidth(0) == 64) &&
      (LiteralLength < 9) && !isNonASCII) {
    // Tiny strings are only used on 64-bit platforms.  They store 8 7-bit
    // ASCII characters in the high 56 bits, followed by a 4-bit length and a
    // 3-bit tag (which is always 4).
    uint64_t str = 0;
    // Fill in the characters
    for (unsigned i=0 ; i<LiteralLength ; i++)
      str |= ((uint64_t)SL->getCodeUnit(i)) << ((64 - 4 - 3) - (i*7));
    // Fill in the length
    str |= LiteralLength << 3;
    // Set the tag
    str |= 4;
    auto *ObjCStr = llvm::ConstantExpr::getIntToPtr(
        llvm::ConstantInt::get(Int64Ty, str), IdTy);
    ObjCStrings[Str] = ObjCStr;
    return ConstantAddress(ObjCStr, Align);
  }

  StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;

  if (StringClass.empty()) StringClass = "NSConstantString";

  std::string Sym = SymbolForClass(StringClass);

  llvm::Constant *isa = TheModule.getNamedGlobal(Sym);

  if (!isa) {
    isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
            llvm::GlobalValue::ExternalLinkage, nullptr, Sym);
    if (CGM.getTriple().isOSBinFormatCOFF()) {
      cast<llvm::GlobalValue>(isa)->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
    }
  } else if (isa->getType() != PtrToIdTy)
    isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);

  //  struct
  //  {
  //    Class isa;
  //    uint32_t flags;
  //    uint32_t length; // Number of codepoints
  //    uint32_t size; // Number of bytes
  //    uint32_t hash;
  //    const char *data;
  //  };

  ConstantInitBuilder Builder(CGM);
  auto Fields = Builder.beginStruct();
  if (!CGM.getTriple().isOSBinFormatCOFF()) {
    Fields.add(isa);
  } else {
    Fields.addNullPointer(PtrTy);
  }
  // For now, all non-ASCII strings are represented as UTF-16.  As such, the
  // number of bytes is simply double the number of UTF-16 codepoints.  In
  // ASCII strings, the number of bytes is equal to the number of non-ASCII
  // codepoints.
  if (isNonASCII) {
    unsigned NumU8CodeUnits = Str.size();
    // A UTF-16 representation of a unicode string contains at most the same
    // number of code units as a UTF-8 representation.  Allocate that much
    // space, plus one for the final null character.
    SmallVector<llvm::UTF16, 128> ToBuf(NumU8CodeUnits + 1);
    const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)Str.data();
    llvm::UTF16 *ToPtr = &ToBuf[0];
    (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumU8CodeUnits,
        &ToPtr, ToPtr + NumU8CodeUnits, llvm::strictConversion);
    uint32_t StringLength = ToPtr - &ToBuf[0];
    // Add null terminator
    *ToPtr = 0;
    // Flags: 2 indicates UTF-16 encoding
    Fields.addInt(Int32Ty, 2);
    // Number of UTF-16 codepoints
    Fields.addInt(Int32Ty, StringLength);
    // Number of bytes
    Fields.addInt(Int32Ty, StringLength * 2);
    // Hash.  Not currently initialised by the compiler.
    Fields.addInt(Int32Ty, 0);
    // pointer to the data string.
    auto Arr = llvm::makeArrayRef(&ToBuf[0], ToPtr+1);
    auto *C = llvm::ConstantDataArray::get(VMContext, Arr);
    auto *Buffer = new llvm::GlobalVariable(TheModule, C->getType(),
        /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, C, ".str");
    Buffer->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
    Fields.add(Buffer);
  } else {
    // Flags: 0 indicates ASCII encoding
    Fields.addInt(Int32Ty, 0);
    // Number of UTF-16 codepoints, each ASCII byte is a UTF-16 codepoint
    Fields.addInt(Int32Ty, Str.size());
    // Number of bytes
    Fields.addInt(Int32Ty, Str.size());
    // Hash.  Not currently initialised by the compiler.
    Fields.addInt(Int32Ty, 0);
    // Data pointer
    Fields.add(MakeConstantString(Str));
  }
  std::string StringName;
  bool isNamed = !isNonASCII;
  if (isNamed) {
    StringName = ".objc_str_";
    for (int i=0,e=Str.size() ; i<e ; ++i) {
      unsigned char c = Str[i];
      if (isalnum(c))
        StringName += c;
      else if (c == ' ')
        StringName += '_';
      else {
        isNamed = false;
        break;
      }
    }
  }
  llvm::GlobalVariable *ObjCStrGV =
    Fields.finishAndCreateGlobal(
        isNamed ? StringRef(StringName) : ".objc_string",
        Align, false, isNamed ? llvm::GlobalValue::LinkOnceODRLinkage
                              : llvm::GlobalValue::PrivateLinkage);
  ObjCStrGV->setSection(sectionName<ConstantStringSection>());
  if (isNamed) {
    ObjCStrGV->setComdat(TheModule.getOrInsertComdat(StringName));
    ObjCStrGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
  }
  if (CGM.getTriple().isOSBinFormatCOFF()) {
    std::pair<llvm::GlobalVariable*, int> v{ObjCStrGV, 0};
    EarlyInitList.emplace_back(Sym, v);
  }
  llvm::Constant *ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStrGV, IdTy);
  ObjCStrings[Str] = ObjCStr;
  ConstantStrings.push_back(ObjCStr);
  return ConstantAddress(ObjCStr, Align);
}

void PushProperty(ConstantArrayBuilder &PropertiesArray,
          const ObjCPropertyDecl *property,
          const Decl *OCD,
          bool isSynthesized=true, bool
          isDynamic=true) override {
  // struct objc_property
  // {
  //   const char *name;
  //   const char *attributes;
  //   const char *type;
  //   SEL getter;
  //   SEL setter;
  // };
  auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
  ASTContext &Context = CGM.getContext();
  Fields.add(MakeConstantString(property->getNameAsString()));
  std::string TypeStr =
    CGM.getContext().getObjCEncodingForPropertyDecl(property, OCD);
  Fields.add(MakeConstantString(TypeStr));
  std::string typeStr;
  Context.getObjCEncodingForType(property->getType(), typeStr);
  Fields.add(MakeConstantString(typeStr));
  auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
    if (accessor) {
      std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
      Fields.add(GetConstantSelector(accessor->getSelector(), TypeStr));
    } else {
      Fields.add(NULLPtr);
    }
  };
  addPropertyMethod(property->getGetterMethodDecl());
  addPropertyMethod(property->getSetterMethodDecl());
  Fields.finishAndAddTo(PropertiesArray);
}

llvm::Constant *
GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) override {
  // struct objc_protocol_method_description
  // {
  //   SEL selector;
  //   const char *types;
  // };
  llvm::StructType *ObjCMethodDescTy =
    llvm::StructType::get(CGM.getLLVMContext(),
        { PtrToInt8Ty, PtrToInt8Ty });
  ASTContext &Context = CGM.getContext();
  ConstantInitBuilder Builder(CGM);
  // struct objc_protocol_method_description_list
  // {
  //   int count;
  //   int size;
  //   struct objc_protocol_method_description methods[];
  // };
  auto MethodList = Builder.beginStruct();
  // int count;
  MethodList.addInt(IntTy, Methods.size());
  // int size; // sizeof(struct objc_method_description)
  llvm::DataLayout td(&TheModule);
  MethodList.addInt(IntTy, td.getTypeSizeInBits(ObjCMethodDescTy) /
      CGM.getContext().getCharWidth());
  // struct objc_method_description[]
  auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
  for (auto *M : Methods) {
    auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
    Method.add(CGObjCGNU::GetConstantSelector(M));
    Method.add(GetTypeString(Context.getObjCEncodingForMethodDecl(M, true)));
    Method.finishAndAddTo(MethodArray);
  }
  MethodArray.finishAndAddTo(MethodList);
  return MethodList.finishAndCreateGlobal(".objc_protocol_method_list",
                                          CGM.getPointerAlign());
}
llvm::Constant *GenerateCategoryProtocolList(const ObjCCategoryDecl *OCD)
  override {
  const auto &ReferencedProtocols = OCD->getReferencedProtocols();
  auto RuntimeProtocols = GetRuntimeProtocolList(ReferencedProtocols.begin(),
                                                 ReferencedProtocols.end());
  SmallVector<llvm::Constant *, 16> Protocols;
  for (const auto *PI : RuntimeProtocols)
    Protocols.push_back(
        llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
          ProtocolPtrTy));
  return GenerateProtocolList(Protocols);
}

llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                            llvm::Value *cmd, MessageSendInfo &MSI) override {
  // Don't access the slot unless we're trying to cache the result.
  CGBuilderTy &Builder = CGF.Builder;
  llvm::Value *lookupArgs[] = {CGObjCGNU::EnforceType(Builder, ObjCSuper,
      PtrToObjCSuperTy).getPointer(), cmd};
  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
}

llvm::GlobalVariable *GetClassVar(StringRef Name, bool isWeak=false) {
  std::string SymbolName = SymbolForClassRef(Name, isWeak);
  auto *ClassSymbol = TheModule.getNamedGlobal(SymbolName);
  if (ClassSymbol)
    return ClassSymbol;
  ClassSymbol = new llvm::GlobalVariable(TheModule,
      IdTy, false, llvm::GlobalValue::ExternalLinkage,
      nullptr, SymbolName);
  // If this is a weak symbol, then we are creating a valid definition for
  // the symbol, pointing to a weak definition of the real class pointer.  If
  // this is not a weak reference, then we are expecting another compilation
  // unit to provide the real indirection symbol.
  if (isWeak)
    ClassSymbol->setInitializer(new llvm::GlobalVariable(TheModule,
        Int8Ty, false, llvm::GlobalValue::ExternalWeakLinkage,
        nullptr, SymbolForClass(Name)));
  else {
    if (CGM.getTriple().isOSBinFormatCOFF()) {
      IdentifierInfo &II = CGM.getContext().Idents.get(Name);
      TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
      DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);

      const ObjCInterfaceDecl *OID = nullptr;
      for (const auto *Result : DC->lookup(&II))
        if ((OID = dyn_cast<ObjCInterfaceDecl>(Result)))
          break;

      // The first Interface we find may be a @class,
      // which should only be treated as the source of
      // truth in the absence of a true declaration.
      assert(OID && "Failed to find ObjCInterfaceDecl")(static_cast<void> (0));
      const ObjCInterfaceDecl *OIDDef = OID->getDefinition();
      if (OIDDef != nullptr)
        OID = OIDDef;

      auto Storage = llvm::GlobalValue::DefaultStorageClass;
      if (OID->hasAttr<DLLImportAttr>())
        Storage = llvm::GlobalValue::DLLImportStorageClass;
      else if (OID->hasAttr<DLLExportAttr>())
        Storage = llvm::GlobalValue::DLLExportStorageClass;

      cast<llvm::GlobalValue>(ClassSymbol)->setDLLStorageClass(Storage);
    }
  }
  assert(ClassSymbol->getName() == SymbolName)(static_cast<void> (0));
  return ClassSymbol;
}
llvm::Value *GetClassNamed(CodeGenFunction &CGF,
                           const std::string &Name,
                           bool isWeak) override {
  return CGF.Builder.CreateLoad(Address(GetClassVar(Name, isWeak),
        CGM.getPointerAlign()));
}
int32_t FlagsForOwnership(Qualifiers::ObjCLifetime Ownership) {
  // typedef enum {
  //   ownership_invalid = 0,
  //   ownership_strong  = 1,
  //   ownership_weak    = 2,
  //   ownership_unsafe  = 3
  // } ivar_ownership;
  int Flag;
  switch (Ownership) {
    case Qualifiers::OCL_Strong:
        Flag = 1;
        break;
    case Qualifiers::OCL_Weak:
        Flag = 2;
        break;
    case Qualifiers::OCL_ExplicitNone:
        Flag = 3;
        break;
    case Qualifiers::OCL_None:
    case Qualifiers::OCL_Autoreleasing:
      assert(Ownership != Qualifiers::OCL_Autoreleasing)(static_cast<void> (0));
      Flag = 0;
  }
  return Flag;
}
llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
                 ArrayRef<llvm::Constant *> IvarTypes,
                 ArrayRef<llvm::Constant *> IvarOffsets,
                 ArrayRef<llvm::Constant *> IvarAlign,
                 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) override {
  llvm_unreachable("Method should not be called!")__builtin_unreachable();
}

llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName) override {
  std::string Name = SymbolForProtocol(ProtocolName);
  auto *GV = TheModule.getGlobalVariable(Name);
  if (!GV) {
    // Emit a placeholder symbol.
    GV = new llvm::GlobalVariable(TheModule, ProtocolTy, false,
        llvm::GlobalValue::ExternalLinkage, nullptr, Name);
    GV->setAlignment(CGM.getPointerAlign().getAsAlign());
  }
  return llvm::ConstantExpr::getBitCast(GV, ProtocolPtrTy);
}

/// Existing protocol references.
llvm::StringMap<llvm::Constant*> ExistingProtocolRefs;

llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
                                 const ObjCProtocolDecl *PD) override {
  auto Name = PD->getNameAsString();
  auto *&Ref = ExistingProtocolRefs[Name];
  if (!Ref) {
    auto *&Protocol = ExistingProtocols[Name];
    if (!Protocol)
      Protocol = GenerateProtocolRef(PD);
    std::string RefName = SymbolForProtocolRef(Name);
    assert(!TheModule.getGlobalVariable(RefName))(static_cast<void> (0));
    // Emit a reference symbol.
    auto GV = new llvm::GlobalVariable(TheModule, ProtocolPtrTy,
        false, llvm::GlobalValue::LinkOnceODRLinkage,
        llvm::ConstantExpr::getBitCast(Protocol, ProtocolPtrTy), RefName);
    GV->setComdat(TheModule.getOrInsertComdat(RefName));
    GV->setSection(sectionName<ProtocolReferenceSection>());
    GV->setAlignment(CGM.getPointerAlign().getAsAlign());
    Ref = GV;
  }
  EmittedProtocolRef = true;
  return CGF.Builder.CreateAlignedLoad(ProtocolPtrTy, Ref,
                                       CGM.getPointerAlign());
}

llvm::Constant *GenerateProtocolList(ArrayRef<llvm::Constant*> Protocols) {
  llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(ProtocolPtrTy,
      Protocols.size());
  llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
      Protocols);
  ConstantInitBuilder builder(CGM);
  auto ProtocolBuilder = builder.beginStruct();
  ProtocolBuilder.addNullPointer(PtrTy);
  ProtocolBuilder.addInt(SizeTy, Protocols.size());
  ProtocolBuilder.add(ProtocolArray);
  return ProtocolBuilder.finishAndCreateGlobal(".objc_protocol_list",
      CGM.getPointerAlign(), false, llvm::GlobalValue::InternalLinkage);
}

void GenerateProtocol(const ObjCProtocolDecl *PD) override {
  // Do nothing - we only emit referenced protocols.
}
llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD) override {
  std::string ProtocolName = PD->getNameAsString();
  auto *&Protocol = ExistingProtocols[ProtocolName];
  if (Protocol)
    return Protocol;

  EmittedProtocol = true;

  auto SymName = SymbolForProtocol(ProtocolName);
  auto *OldGV = TheModule.getGlobalVariable(SymName);

  // Use the protocol definition, if there is one.
  if (const ObjCProtocolDecl *Def = PD->getDefinition())
    PD = Def;
  else {
    // If there is no definition, then create an external linkage symbol and
    // hope that someone else fills it in for us (and fail to link if they
    // don't).
    assert(!OldGV)(static_cast<void> (0));
    Protocol = new llvm::GlobalVariable(TheModule, ProtocolTy,
      /*isConstant*/false,
      llvm::GlobalValue::ExternalLinkage, nullptr, SymName);
    return Protocol;
  }

  SmallVector<llvm::Constant*, 16> Protocols;
  auto RuntimeProtocols =
      GetRuntimeProtocolList(PD->protocol_begin(), PD->protocol_end());
  for (const auto *PI : RuntimeProtocols)
    Protocols.push_back(
        llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
          ProtocolPtrTy));
  llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);

  // Collect information about methods
  llvm::Constant *InstanceMethodList, *OptionalInstanceMethodList;
  llvm::Constant *ClassMethodList, *OptionalClassMethodList;
  EmitProtocolMethodList(PD->instance_methods(), InstanceMethodList,
      OptionalInstanceMethodList);
  EmitProtocolMethodList(PD->class_methods(), ClassMethodList,
      OptionalClassMethodList);

  // The isa pointer must be set to a magic number so the runtime knows it's
  // the correct layout.
  ConstantInitBuilder builder(CGM);
  auto ProtocolBuilder = builder.beginStruct();
  ProtocolBuilder.add(llvm::ConstantExpr::getIntToPtr(
        llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
  ProtocolBuilder.add(MakeConstantString(ProtocolName));
  ProtocolBuilder.add(ProtocolList);
  ProtocolBuilder.add(InstanceMethodList);
  ProtocolBuilder.add(ClassMethodList);
  ProtocolBuilder.add(OptionalInstanceMethodList);
  ProtocolBuilder.add(OptionalClassMethodList);
  // Required instance properties
  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, false));
  // Optional instance properties
  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, true));
  // Required class properties
  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, false));
  // Optional class properties
  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, true));

  auto *GV = ProtocolBuilder.finishAndCreateGlobal(SymName,
      CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);
  GV->setSection(sectionName<ProtocolSection>());
  GV->setComdat(TheModule.getOrInsertComdat(SymName));
  if (OldGV) {
    OldGV->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GV,
          OldGV->getType()));
    OldGV->removeFromParent();
    GV->setName(SymName);
  }
  Protocol = GV;
  return GV;
}
llvm::Constant *EnforceType(llvm::Constant *Val, llvm::Type *Ty) {
  if (Val->getType() == Ty)
    return Val;
  return llvm::ConstantExpr::getBitCast(Val, Ty);
}
llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
                              const std::string &TypeEncoding) override {
  return GetConstantSelector(Sel, TypeEncoding);
}
llvm::Constant  *GetTypeString(llvm::StringRef TypeEncoding) {
  if (TypeEncoding.empty())
    return NULLPtr;
  std::string MangledTypes = std::string(TypeEncoding);
  std::replace(MangledTypes.begin(), MangledTypes.end(),
    '@', '\1');
  std::string TypesVarName = ".objc_sel_types_" + MangledTypes;
  auto *TypesGlobal = TheModule.getGlobalVariable(TypesVarName);
  if (!TypesGlobal) {
    llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
        TypeEncoding);
    auto *GV = new llvm::GlobalVariable(TheModule, Init->getType(),
        true, llvm::GlobalValue::LinkOnceODRLinkage, Init, TypesVarName);
    GV->setComdat(TheModule.getOrInsertComdat(TypesVarName));
    GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
    TypesGlobal = GV;
  }
  return llvm::ConstantExpr::getGetElementPtr(TypesGlobal->getValueType(),
      TypesGlobal, Zeros);
}
llvm::Constant *GetConstantSelector(Selector Sel,
                                    const std::string &TypeEncoding) override {
  // @ is used as a special character in symbol names (used for symbol
  // versioning), so mangle the name to not include it.  Replace it with a
  // character that is not a valid type encoding character (and, being
  // non-printable, never will be!)
  std::string MangledTypes = TypeEncoding;
  std::replace(MangledTypes.begin(), MangledTypes.end(),
    '@', '\1');
  auto SelVarName = (StringRef(".objc_selector_") + Sel.getAsString() + "_" +
    MangledTypes).str();
  if (auto *GV = TheModule.getNamedGlobal(SelVarName))
    return EnforceType(GV, SelectorTy);
  ConstantInitBuilder builder(CGM);
  auto SelBuilder = builder.beginStruct();
  SelBuilder.add(ExportUniqueString(Sel.getAsString(), ".objc_sel_name_",
        true));
  SelBuilder.add(GetTypeString(TypeEncoding));
  auto *GV = SelBuilder.finishAndCreateGlobal(SelVarName,
      CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
  GV->setComdat(TheModule.getOrInsertComdat(SelVarName));
  GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
  GV->setSection(sectionName<SelectorSection>());
  auto *SelVal = EnforceType(GV, SelectorTy);
  return SelVal;
}
llvm::StructType *emptyStruct = nullptr;

/// Return pointers to the start and end of a section.  On ELF platforms, we
/// use the __start_ and __stop_ symbols that GNU-compatible linkers will set
/// to the start and end of section names, as long as those section names are
/// valid identifiers and the symbols are referenced but not defined.  On
/// Windows, we use the fact that MSVC-compatible linkers will lexically sort
/// by subsections and place everything that we want to reference in a middle
/// subsection and then insert zero-sized symbols in subsections a and z.
std::pair<llvm::Constant*,llvm::Constant*>
GetSectionBounds(StringRef Section) {
  if (CGM.getTriple().isOSBinFormatCOFF()) {
    if (emptyStruct == nullptr) {
      emptyStruct = llvm::StructType::create(VMContext, ".objc_section_sentinel");
      emptyStruct->setBody({}, /*isPacked*/true);
    }
    auto ZeroInit = llvm::Constant::getNullValue(emptyStruct);
    auto Sym = [&](StringRef Prefix, StringRef SecSuffix) {
      auto *Sym = new llvm::GlobalVariable(TheModule, emptyStruct,
          /*isConstant*/false,
          llvm::GlobalValue::LinkOnceODRLinkage, ZeroInit, Prefix +
          Section);
      Sym->setVisibility(llvm::GlobalValue::HiddenVisibility);
      Sym->setSection((Section + SecSuffix).str());
      Sym->setComdat(TheModule.getOrInsertComdat((Prefix +
          Section).str()));
      Sym->setAlignment(CGM.getPointerAlign().getAsAlign());
      return Sym;
    };
    return { Sym("__start_", "$a"), Sym("__stop", "$z") };
  }
  auto *Start = new llvm::GlobalVariable(TheModule, PtrTy,
      /*isConstant*/false,
      llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__start_") +
      Section);
  Start->setVisibility(llvm::GlobalValue::HiddenVisibility);
  auto *Stop = new llvm::GlobalVariable(TheModule, PtrTy,
      /*isConstant*/false,
      llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__stop_") +
      Section);
  Stop->setVisibility(llvm::GlobalValue::HiddenVisibility);
  return { Start, Stop };
}
CatchTypeInfo getCatchAllTypeInfo() override {
  return CGM.getCXXABI().getCatchAllTypeInfo();
}
llvm::Function *ModuleInitFunction() override {
  llvm::Function *LoadFunction = llvm::Function::Create(
    llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
    llvm::GlobalValue::LinkOnceODRLinkage, ".objcv2_load_function",
    &TheModule);
  LoadFunction->setVisibility(llvm::GlobalValue::HiddenVisibility);
  LoadFunction->setComdat(TheModule.getOrInsertComdat(".objcv2_load_function"));

  llvm::BasicBlock *EntryBB =
      llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
  CGBuilderTy B(CGM, VMContext);
  B.SetInsertPoint(EntryBB);
  ConstantInitBuilder builder(CGM);
  auto InitStructBuilder = builder.beginStruct();
  InitStructBuilder.addInt(Int64Ty, 0);
  auto &sectionVec = CGM.getTriple().isOSBinFormatCOFF() ? PECOFFSectionsBaseNames : SectionsBaseNames;
  for (auto *s : sectionVec) {
    auto bounds = GetSectionBounds(s);
    InitStructBuilder.add(bounds.first);
    InitStructBuilder.add(bounds.second);
  }
  auto *InitStruct = InitStructBuilder.finishAndCreateGlobal(".objc_init",
      CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
  InitStruct->setVisibility(llvm::GlobalValue::HiddenVisibility);
  InitStruct->setComdat(TheModule.getOrInsertComdat(".objc_init"));

  CallRuntimeFunction(B, "__objc_load", {InitStruct});;
  B.CreateRetVoid();
  // Make sure that the optimisers don't delete this function.
  CGM.addCompilerUsedGlobal(LoadFunction);
  // FIXME: Currently ELF only!
  // We have to do this by hand, rather than with @llvm.ctors, so that the
  // linker can remove the duplicate invocations.
  auto *InitVar = new llvm::GlobalVariable(TheModule, LoadFunction->getType(),
      /*isConstant*/false, llvm::GlobalValue::LinkOnceAnyLinkage,
      LoadFunction, ".objc_ctor");
  // Check that this hasn't been renamed.  This shouldn't happen, because
  // this function should be called precisely once.
  assert(InitVar->getName() == ".objc_ctor")(static_cast<void> (0));
  // In Windows, initialisers are sorted by the suffix.  XCL is for library
  // initialisers, which run before user initialisers.  We are running
  // Objective-C loads at the end of library load.  This means +load methods
  // will run before any other static constructors, but that static
  // constructors can see a fully initialised Objective-C state.
  if (CGM.getTriple().isOSBinFormatCOFF())
      InitVar->setSection(".CRT$XCLz");
  else
  {
    if (CGM.getCodeGenOpts().UseInitArray)
      InitVar->setSection(".init_array");
    else
      InitVar->setSection(".ctors");
  }
  InitVar->setVisibility(llvm::GlobalValue::HiddenVisibility);
  InitVar->setComdat(TheModule.getOrInsertComdat(".objc_ctor"));
  CGM.addUsedGlobal(InitVar);
  for (auto *C : Categories) {
    auto *Cat = cast<llvm::GlobalVariable>(C->stripPointerCasts());
    Cat->setSection(sectionName<CategorySection>());
    CGM.addUsedGlobal(Cat);
  }
  auto createNullGlobal = [&](StringRef Name, ArrayRef<llvm::Constant*> Init,
      StringRef Section) {
    auto nullBuilder = builder.beginStruct();
    for (auto *F : Init)
      nullBuilder.add(F);
    auto GV = nullBuilder.finishAndCreateGlobal(Name, CGM.getPointerAlign(),
        false, llvm::GlobalValue::LinkOnceODRLinkage);
    GV->setSection(Section);
    GV->setComdat(TheModule.getOrInsertComdat(Name));
    GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
    CGM.addUsedGlobal(GV);
    return GV;
  };
  for (auto clsAlias : ClassAliases)
    createNullGlobal(std::string(".objc_class_alias") +
        clsAlias.second, { MakeConstantString(clsAlias.second),
        GetClassVar(clsAlias.first) }, sectionName<ClassAliasSection>());
  // On ELF platforms, add a null value for each special section so that we
  // can always guarantee that the _start and _stop symbols will exist and be
  // meaningful.  This is not required on COFF platforms, where our start and
  // stop symbols will create the section.
  if (!CGM.getTriple().isOSBinFormatCOFF()) {
    createNullGlobal(".objc_null_selector", {NULLPtr, NULLPtr},
        sectionName<SelectorSection>());
    if (Categories.empty())
      createNullGlobal(".objc_null_category", {NULLPtr, NULLPtr,
                    NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr},
          sectionName<CategorySection>());
    if (!EmittedClass) {
      createNullGlobal(".objc_null_cls_init_ref", NULLPtr,
          sectionName<ClassSection>());
      createNullGlobal(".objc_null_class_ref", { NULLPtr, NULLPtr },
          sectionName<ClassReferenceSection>());
    }
    if (!EmittedProtocol)
      createNullGlobal(".objc_null_protocol", {NULLPtr, NULLPtr, NULLPtr,
          NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr,
          NULLPtr}, sectionName<ProtocolSection>());
    if (!EmittedProtocolRef)
      createNullGlobal(".objc_null_protocol_ref", {NULLPtr},
          sectionName<ProtocolReferenceSection>());
    if (ClassAliases.empty())
      createNullGlobal(".objc_null_class_alias", { NULLPtr, NULLPtr },
          sectionName<ClassAliasSection>());
    if (ConstantStrings.empty()) {
      auto i32Zero = llvm::ConstantInt::get(Int32Ty, 0);
      createNullGlobal(".objc_null_constant_string", { NULLPtr, i32Zero,
          i32Zero, i32Zero, i32Zero, NULLPtr },
          sectionName<ConstantStringSection>());
    }
  }
  ConstantStrings.clear();
  Categories.clear();
  Classes.clear();

  if (EarlyInitList.size() > 0) {
    auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
          {}), llvm::GlobalValue::InternalLinkage, ".objc_early_init",
        &CGM.getModule());
    llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
          Init));
    for (const auto &lateInit : EarlyInitList) {
      auto *global = TheModule.getGlobalVariable(lateInit.first);
      if (global) {
        llvm::GlobalVariable *GV = lateInit.second.first;
        b.CreateAlignedStore(
            global,
            b.CreateStructGEP(GV->getValueType(), GV, lateInit.second.second),
            CGM.getPointerAlign().getAsAlign());
      }
    }
    b.CreateRetVoid();
    // We can't use the normal LLVM global initialisation array, because we
    // need to specify that this runs early in library initialisation.
    auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
        /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
        Init, ".objc_early_init_ptr");
    InitVar->setSection(".CRT$XCLb");
    CGM.addUsedGlobal(InitVar);
  }
  return nullptr;
}
/// In the v2 ABI, ivar offset variables use the type encoding in their name
/// to trigger linker failures if the types don't match.
std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
                                      const ObjCIvarDecl *Ivar) override {
  std::string TypeEncoding;
  CGM.getContext().getObjCEncodingForType(Ivar->getType(), TypeEncoding);
  // Prevent the @ from being interpreted as a symbol version.
  std::replace(TypeEncoding.begin(), TypeEncoding.end(),
    '@', '\1');
  const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
    + '.' + Ivar->getNameAsString() + '.' + TypeEncoding;
  return Name;
}
llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
                            const ObjCInterfaceDecl *Interface,
                            const ObjCIvarDecl *Ivar) override {
  const std::string Name = GetIVarOffsetVariableName(Ivar->getContainingInterface(), Ivar);
  llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
  if (!IvarOffsetPointer)
    IvarOffsetPointer = new llvm::GlobalVariable(TheModule, IntTy, false,
            llvm::GlobalValue::ExternalLinkage, nullptr, Name);
  CharUnits Align = CGM.getIntAlign();
  llvm::Value *Offset =
      CGF.Builder.CreateAlignedLoad(IntTy, IvarOffsetPointer, Align);
  if (Offset->getType() != PtrDiffTy)
    Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
  return Offset;
}
void GenerateClass(const ObjCImplementationDecl *OID) override {
  ASTContext &Context = CGM.getContext();
  bool IsCOFF = CGM.getTriple().isOSBinFormatCOFF();

  // Get the class name
  ObjCInterfaceDecl *classDecl =
      const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
  std::string className = classDecl->getNameAsString();
  auto *classNameConstant = MakeConstantString(className);

  ConstantInitBuilder builder(CGM);
  auto metaclassFields = builder.beginStruct();
  // struct objc_class *isa;
  metaclassFields.addNullPointer(PtrTy);
  // struct objc_class *super_class;
  metaclassFields.addNullPointer(PtrTy);
  // const char *name;
  metaclassFields.add(classNameConstant);
  // long version;
  metaclassFields.addInt(LongTy, 0);
  // unsigned long info;
  // objc_class_flag_meta
  metaclassFields.addInt(LongTy, 1);
  // long instance_size;
  // Setting this to zero is consistent with the older ABI, but it might be
  // more sensible to set this to sizeof(struct objc_class)
  metaclassFields.addInt(LongTy, 0);
  // struct objc_ivar_list *ivars;
  metaclassFields.addNullPointer(PtrTy);
  // struct objc_method_list *methods
  // FIXME: Almost identical code is copied and pasted below for the
  // class, but refactoring it cleanly requires C++14 generic lambdas.
  if (OID->classmeth_begin() == OID->classmeth_end())
    metaclassFields.addNullPointer(PtrTy);
  else {
    SmallVector<ObjCMethodDecl*, 16> ClassMethods;
    ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
        OID->classmeth_end());
    metaclassFields.addBitCast(
            GenerateMethodList(className, "", ClassMethods, true),
            PtrTy);
  }
  // void *dtable;
  metaclassFields.addNullPointer(PtrTy);
  // IMP cxx_construct;
  metaclassFields.addNullPointer(PtrTy);
  // IMP cxx_destruct;
  metaclassFields.addNullPointer(PtrTy);
  // struct objc_class *subclass_list
  metaclassFields.addNullPointer(PtrTy);
  // struct objc_class *sibling_class
  metaclassFields.addNullPointer(PtrTy);
  // struct objc_protocol_list *protocols;
  metaclassFields.addNullPointer(PtrTy);
  // struct reference_list *extra_data;
  metaclassFields.addNullPointer(PtrTy);
  // long abi_version;
  metaclassFields.addInt(LongTy, 0);
  // struct objc_property_list *properties
  metaclassFields.add(GeneratePropertyList(OID, classDecl, /*isClassProperty*/true));

  auto *metaclass = metaclassFields.finishAndCreateGlobal(
      ManglePublicSymbol("OBJC_METACLASS_") + className,
      CGM.getPointerAlign());

  auto classFields = builder.beginStruct();
  // struct objc_class *isa;
  classFields.add(metaclass);
  // struct objc_class *super_class;
  // Get the superclass name.
  const ObjCInterfaceDecl * SuperClassDecl =
    OID->getClassInterface()->getSuperClass();
  llvm::Constant *SuperClass = nullptr;
  if (SuperClassDecl) {
    auto SuperClassName = SymbolForClass(SuperClassDecl->getNameAsString());
    SuperClass = TheModule.getNamedGlobal(SuperClassName);
    if (!SuperClass)
    {
      SuperClass = new llvm::GlobalVariable(TheModule, PtrTy, false,
          llvm::GlobalValue::ExternalLinkage, nullptr, SuperClassName);
      if (IsCOFF) {
        auto Storage = llvm::GlobalValue::DefaultStorageClass;
        if (SuperClassDecl->hasAttr<DLLImportAttr>())
          Storage = llvm::GlobalValue::DLLImportStorageClass;
        else if (SuperClassDecl->hasAttr<DLLExportAttr>())
          Storage = llvm::GlobalValue::DLLExportStorageClass;

        cast<llvm::GlobalValue>(SuperClass)->setDLLStorageClass(Storage);
      }
    }
    if (!IsCOFF)
      classFields.add(llvm::ConstantExpr::getBitCast(SuperClass, PtrTy));
    else
      classFields.addNullPointer(PtrTy);
  } else
    classFields.addNullPointer(PtrTy);
  // const char *name;
  classFields.add(classNameConstant);
  // long version;
  classFields.addInt(LongTy, 0);
  // unsigned long info;
  // !objc_class_flag_meta
  classFields.addInt(LongTy, 0);
  // long instance_size;
  int superInstanceSize = !SuperClassDecl ? 0 :
    Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
  // Instance size is negative for classes that have not yet had their ivar
  // layout calculated.
  classFields.addInt(LongTy,
    0 - (Context.getASTObjCImplementationLayout(OID).getSize().getQuantity() -
    superInstanceSize));

  if (classDecl->all_declared_ivar_begin() == nullptr)
    classFields.addNullPointer(PtrTy);
  else {
    int ivar_count = 0;
    for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
         IVD = IVD->getNextIvar()) ivar_count++;
    llvm::DataLayout td(&TheModule);
    // struct objc_ivar_list *ivars;
    ConstantInitBuilder b(CGM);
    auto ivarListBuilder = b.beginStruct();
    // int count;
    ivarListBuilder.addInt(IntTy, ivar_count);
    // size_t size;
    llvm::StructType *ObjCIvarTy = llvm::StructType::get(
      PtrToInt8Ty,
      PtrToInt8Ty,
      PtrToInt8Ty,
      Int32Ty,
      Int32Ty);
    ivarListBuilder.addInt(SizeTy, td.getTypeSizeInBits(ObjCIvarTy) /
        CGM.getContext().getCharWidth());
    // struct objc_ivar ivars[]
    auto ivarArrayBuilder = ivarListBuilder.beginArray();
    for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
         IVD = IVD->getNextIvar()) {
      auto ivarTy = IVD->getType();
      auto ivarBuilder = ivarArrayBuilder.beginStruct();
      // const char *name;
      ivarBuilder.add(MakeConstantString(IVD->getNameAsString()));
      // const char *type;
      std::string TypeStr;
      //Context.getObjCEncodingForType(ivarTy, TypeStr, IVD, true);
      Context.getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None, ivarTy, TypeStr, true);
      ivarBuilder.add(MakeConstantString(TypeStr));
      // int *offset;
      uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
      uint64_t Offset = BaseOffset - superInstanceSize;
      llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
      std::string OffsetName = GetIVarOffsetVariableName(classDecl, IVD);
      llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
      if (OffsetVar)
        OffsetVar->setInitializer(OffsetValue);
      else
        OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
          false, llvm::GlobalValue::ExternalLinkage,
          OffsetValue, OffsetName);
      auto ivarVisibility =
          (IVD->getAccessControl() == ObjCIvarDecl::Private ||
           IVD->getAccessControl() == ObjCIvarDecl::Package ||
           classDecl->getVisibility() == HiddenVisibility) ?
                  llvm::GlobalValue::HiddenVisibility :
                  llvm::GlobalValue::DefaultVisibility;
      OffsetVar->setVisibility(ivarVisibility);
      ivarBuilder.add(OffsetVar);
      // Ivar size
      ivarBuilder.addInt(Int32Ty,
          CGM.getContext().getTypeSizeInChars(ivarTy).getQuantity());
      // Alignment will be stored as a base-2 log of the alignment.
      unsigned align =
          llvm::Log2_32(Context.getTypeAlignInChars(ivarTy).getQuantity());
      // Objects that require more than 2^64-byte alignment should be impossible!
      assert(align < 64)(static_cast<void> (0));
      // uint32_t flags;
      // Bits 0-1 are ownership.
      // Bit 2 indicates an extended type encoding
      // Bits 3-8 contain log2(aligment)
      ivarBuilder.addInt(Int32Ty,
          (align << 3) | (1<<2) |
          FlagsForOwnership(ivarTy.getQualifiers().getObjCLifetime()));
      ivarBuilder.finishAndAddTo(ivarArrayBuilder);
    }
    ivarArrayBuilder.finishAndAddTo(ivarListBuilder);
    auto ivarList = ivarListBuilder.finishAndCreateGlobal(".objc_ivar_list",
        CGM.getPointerAlign(), /*constant*/ false,
        llvm::GlobalValue::PrivateLinkage);
    classFields.add(ivarList);
  }
  // struct objc_method_list *methods
  SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
  InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
      OID->instmeth_end());
  for (auto *propImpl : OID->property_impls())
    if (propImpl->getPropertyImplementation() ==
        ObjCPropertyImplDecl::Synthesize) {
      auto addIfExists = [&](const ObjCMethodDecl *OMD) {
        if (OMD && OMD->hasBody())
          InstanceMethods.push_back(OMD);
      };
      addIfExists(propImpl->getGetterMethodDecl());
      addIfExists(propImpl->getSetterMethodDecl());
    }

  if (InstanceMethods.size() == 0)
    classFields.addNullPointer(PtrTy);
  else
    classFields.addBitCast(
            GenerateMethodList(className, "", InstanceMethods, false),
            PtrTy);
  // void *dtable;
  classFields.addNullPointer(PtrTy);
  // IMP cxx_construct;
  classFields.addNullPointer(PtrTy);
  // IMP cxx_destruct;
  classFields.addNullPointer(PtrTy);
  // struct objc_class *subclass_list
  classFields.addNullPointer(PtrTy);
  // struct objc_class *sibling_class
  classFields.addNullPointer(PtrTy);
  // struct objc_protocol_list *protocols;
  auto RuntimeProtocols = GetRuntimeProtocolList(classDecl->protocol_begin(),
                                                 classDecl->protocol_end());
  SmallVector<llvm::Constant *, 16> Protocols;
  for (const auto *I : RuntimeProtocols)
    Protocols.push_back(
        llvm::ConstantExpr::getBitCast(GenerateProtocolRef(I),
          ProtocolPtrTy));
  if (Protocols.empty())
    classFields.addNullPointer(PtrTy);
  else
    classFields.add(GenerateProtocolList(Protocols));
  // struct reference_list *extra_data;
  classFields.addNullPointer(PtrTy);
  // long abi_version;
  classFields.addInt(LongTy, 0);
  // struct objc_property_list *properties
  classFields.add(GeneratePropertyList(OID, classDecl));

  llvm::GlobalVariable *classStruct =
    classFields.finishAndCreateGlobal(SymbolForClass(className),
      CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);

  auto *classRefSymbol = GetClassVar(className);
  classRefSymbol->setSection(sectionName<ClassReferenceSection>());
  classRefSymbol->setInitializer(llvm::ConstantExpr::getBitCast(classStruct, IdTy));

  if (IsCOFF) {
    // we can't import a class struct.
    if (OID->getClassInterface()->hasAttr<DLLExportAttr>()) {
      classStruct->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
      cast<llvm::GlobalValue>(classRefSymbol)->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
    }

    if (SuperClass) {
      std::pair<llvm::GlobalVariable*, int> v{classStruct, 1};
      EarlyInitList.emplace_back(std::string(SuperClass->getName()),
                                 std::move(v));
    }

  }


  // Resolve the class aliases, if they exist.
  // FIXME: Class pointer aliases shouldn't exist!
  if (ClassPtrAlias) {
    ClassPtrAlias->replaceAllUsesWith(
        llvm::ConstantExpr::getBitCast(classStruct, IdTy));
    ClassPtrAlias->eraseFromParent();
    ClassPtrAlias = nullptr;
  }
  if (auto Placeholder =
      TheModule.getNamedGlobal(SymbolForClass(className)))
    if (Placeholder != classStruct) {
      Placeholder->replaceAllUsesWith(
          llvm::ConstantExpr::getBitCast(classStruct, Placeholder->getType()));
      Placeholder->eraseFromParent();
      classStruct->setName(SymbolForClass(className));
    }
  if (MetaClassPtrAlias) {
    MetaClassPtrAlias->replaceAllUsesWith(
        llvm::ConstantExpr::getBitCast(metaclass, IdTy));
    MetaClassPtrAlias->eraseFromParent();
    MetaClassPtrAlias = nullptr;
  }
  assert(classStruct->getName() == SymbolForClass(className))(static_cast<void> (0));

  auto classInitRef = new llvm::GlobalVariable(TheModule,
      classStruct->getType(), false, llvm::GlobalValue::ExternalLinkage,
      classStruct, ManglePublicSymbol("OBJC_INIT_CLASS_") + className);
  classInitRef->setSection(sectionName<ClassSection>());
  CGM.addUsedGlobal(classInitRef);

  EmittedClass = true;
}
public:
  CGObjCGNUstep2(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 10, 4, 2) {
    MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
                          PtrToObjCSuperTy, SelectorTy);
    // struct objc_property
    // {
    //   const char *name;
    //   const char *attributes;
    //   const char *type;
    //   SEL getter;
    //   SEL setter;
    // }
    PropertyMetadataTy =
      llvm::StructType::get(CGM.getLLVMContext(),
          { PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
  }

2016};

2018const char *const CGObjCGNUstep2::SectionsBaseNames[8] =
2019{
2020"__objc_selectors",
2021"__objc_classes",
2022"__objc_class_refs",
2023"__objc_cats",
2024"__objc_protocols",
2025"__objc_protocol_refs",
2026"__objc_class_aliases",
2027"__objc_constant_string"
2028};

2030const char *const CGObjCGNUstep2::PECOFFSectionsBaseNames[8] =
2031{
2032".objcrt$SEL",
2033".objcrt$CLS",
2034".objcrt$CLR",
2035".objcrt$CAT",
2036".objcrt$PCL",
2037".objcrt$PCR",
2038".objcrt$CAL",
2039".objcrt$STR"
2040};

2042/// Support for the ObjFW runtime.
2043class CGObjCObjFW: public CGObjCGNU {
2044protected:
/// The GCC ABI message lookup function.  Returns an IMP pointing to the
/// method implementation for this message.
LazyRuntimeFunction MsgLookupFn;
/// stret lookup function.  While this does not seem to make sense at the
/// first look, this is required to call the correct forwarding function.
LazyRuntimeFunction MsgLookupFnSRet;
/// The GCC ABI superclass message lookup function.  Takes a pointer to a
/// structure describing the receiver and the class, and a selector as
/// arguments.  Returns the IMP for the corresponding method.
LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;

llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
                       llvm::Value *cmd, llvm::MDNode *node,
                       MessageSendInfo &MSI) override {
  CGBuilderTy &Builder = CGF.Builder;
  llvm::Value *args[] = {
          EnforceType(Builder, Receiver, IdTy),
          EnforceType(Builder, cmd, SelectorTy) };

  llvm::CallBase *imp;
  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
    imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
  else
    imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);

  imp->setMetadata(msgSendMDKind, node);
  return imp;
}

llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
                            llvm::Value *cmd, MessageSendInfo &MSI) override {
  CGBuilderTy &Builder = CGF.Builder;
  llvm::Value *lookupArgs[] = {
      EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
  };

  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
    return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
  else
    return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
}

llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
                           bool isWeak) override {
  if (isWeak)
    return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);

  EmitClassRef(Name);
  std::string SymbolName = "_OBJC_CLASS_" + Name;
  llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
  if (!ClassSymbol)
    ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
                                           llvm::GlobalValue::ExternalLinkage,
                                           nullptr, SymbolName);
  return ClassSymbol;
}

2102public:
CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
  // IMP objc_msg_lookup(id, SEL);
  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
  MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
                       SelectorTy);
  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
                        PtrToObjCSuperTy, SelectorTy);
  MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
                            PtrToObjCSuperTy, SelectorTy);
}
2114};
2115} // end anonymous namespace

2117/// Emits a reference to a dummy variable which is emitted with each class.
2118/// This ensures that a linker error will be generated when trying to link
2119/// together modules where a referenced class is not defined.
2120void CGObjCGNU::EmitClassRef(const std::string &className) {
std::string symbolRef = "__objc_class_ref_" + className;
// Don't emit two copies of the same symbol
if (TheModule.getGlobalVariable(symbolRef))
  return;
std::string symbolName = "__objc_class_name_" + className;
llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
if (!ClassSymbol) {
  ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
                                         llvm::GlobalValue::ExternalLinkage,
                                         nullptr, symbolName);
}
new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
  llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
2134}

2136CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
                   unsigned protocolClassVersion, unsigned classABI)
: CGObjCRuntime(cgm), TheModule(CGM.getModule()),
  VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
  MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
  ProtocolVersion(protocolClassVersion), ClassABIVersion(classABI) {

msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
usesSEHExceptions =
    cgm.getContext().getTargetInfo().getTriple().isWindowsMSVCEnvironment();

CodeGenTypes &Types = CGM.getTypes();
IntTy = cast<llvm::IntegerType>(
    Types.ConvertType(CGM.getContext().IntTy));
LongTy = cast<llvm::IntegerType>(
    Types.ConvertType(CGM.getContext().LongTy));
SizeTy = cast<llvm::IntegerType>(
    Types.ConvertType(CGM.getContext().getSizeType()));
PtrDiffTy = cast<llvm::IntegerType>(
    Types.ConvertType(CGM.getContext().getPointerDiffType()));
BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);

Int8Ty = llvm::Type::getInt8Ty(VMContext);
// C string type.  Used in lots of places.
PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
ProtocolPtrTy = llvm::PointerType::getUnqual(
    Types.ConvertType(CGM.getContext().getObjCProtoType()));

Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
Zeros[1] = Zeros[0];
NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
// Get the selector Type.
QualType selTy = CGM.getContext().getObjCSelType();
if (QualType() == selTy) {
  SelectorTy = PtrToInt8Ty;
} else {
  SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
}

PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
PtrTy = PtrToInt8Ty;

Int32Ty = llvm::Type::getInt32Ty(VMContext);
Int64Ty = llvm::Type::getInt64Ty(VMContext);

IntPtrTy =
    CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;

// Object type
QualType UnqualIdTy = CGM.getContext().getObjCIdType();
ASTIdTy = CanQualType();
if (UnqualIdTy != QualType()) {
  ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
  IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
} else {
  IdTy = PtrToInt8Ty;
}
PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
ProtocolTy = llvm::StructType::get(IdTy,
    PtrToInt8Ty, // name
    PtrToInt8Ty, // protocols
    PtrToInt8Ty, // instance methods
    PtrToInt8Ty, // class methods
    PtrToInt8Ty, // optional instance methods
    PtrToInt8Ty, // optional class methods
    PtrToInt8Ty, // properties
    PtrToInt8Ty);// optional properties

// struct objc_property_gsv1
// {
//   const char *name;
//   char attributes;
//   char attributes2;
//   char unused1;
//   char unused2;
//   const char *getter_name;
//   const char *getter_types;
//   const char *setter_name;
//   const char *setter_types;
// }
PropertyMetadataTy = llvm::StructType::get(CGM.getLLVMContext(), {
    PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty,
    PtrToInt8Ty, PtrToInt8Ty });

ObjCSuperTy = llvm::StructType::get(IdTy, IdTy);
PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);

llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);

// void objc_exception_throw(id);
ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
// int objc_sync_enter(id);
SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
// int objc_sync_exit(id);
SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy);

// void objc_enumerationMutation (id)
EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, IdTy);

// id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
                   PtrDiffTy, BoolTy);
// void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
                   PtrDiffTy, IdTy, BoolTy, BoolTy);
// void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
                         PtrDiffTy, BoolTy, BoolTy);
// void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
                         PtrDiffTy, BoolTy, BoolTy);

// IMP type
llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
            true));

const LangOptions &Opts = CGM.getLangOpts();
if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
  RuntimeVersion = 10;

// Don't bother initialising the GC stuff unless we're compiling in GC mode
if (Opts.getGC() != LangOptions::NonGC) {
  // This is a bit of an hack.  We should sort this out by having a proper
  // CGObjCGNUstep subclass for GC, but we may want to really support the old
  // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
  // Get selectors needed in GC mode
  RetainSel = GetNullarySelector("retain", CGM.getContext());
  ReleaseSel = GetNullarySelector("release", CGM.getContext());
  AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());

  // Get functions needed in GC mode

  // id objc_assign_ivar(id, id, ptrdiff_t);
  IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy);
  // id objc_assign_strongCast (id, id*)
  StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
                          PtrToIdTy);
  // id objc_assign_global(id, id*);
  GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy);
  // id objc_assign_weak(id, id*);
  WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy);
  // id objc_read_weak(id*);
  WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy);
  // void *objc_memmove_collectable(void*, void *, size_t);
  MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
                 SizeTy);
}
2285}

2287llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
                                    const std::string &Name, bool isWeak) {
llvm::Constant *ClassName = MakeConstantString(Name);
// With the incompatible ABI, this will need to be replaced with a direct
// reference to the class symbol.  For the compatible nonfragile ABI we are
// still performing this lookup at run time but emitting the symbol for the
// class externally so that we can make the switch later.
//
// Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
// with memoized versions or with static references if it's safe to do so.
if (!isWeak)
  EmitClassRef(Name);

llvm::FunctionCallee ClassLookupFn = CGM.CreateRuntimeFunction(
    llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), "objc_lookup_class");
return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
2303}

2305// This has to perform the lookup every time, since posing and related
2306// techniques can modify the name -> class mapping.
2307llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
                               const ObjCInterfaceDecl *OID) {
auto *Value =
    GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value))
  CGM.setGVProperties(ClassSymbol, OID);
return Value;
2314}

2316llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
auto *Value  = GetClassNamed(CGF, "NSAutoreleasePool", false);
if (CGM.getTriple().isOSBinFormatCOFF()) {
  if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
    IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
    TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
    DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);

    const VarDecl *VD = nullptr;
    for (const auto *Result : DC->lookup(&II))
      if ((VD = dyn_cast<VarDecl>(Result)))
        break;

    CGM.setGVProperties(ClassSymbol, VD);
  }
}
return Value;
2333}

2335llvm::Value *CGObjCGNU::GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
                                       const std::string &TypeEncoding) {
SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
llvm::GlobalAlias *SelValue = nullptr;

for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
    e = Types.end() ; i!=e ; i++) {
  if (i->first == TypeEncoding) {
    SelValue = i->second;
    break;
  }
}
if (!SelValue) {
  SelValue = llvm::GlobalAlias::create(
      SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage,
      ".objc_selector_" + Sel.getAsString(), &TheModule);
  Types.emplace_back(TypeEncoding, SelValue);
}

return SelValue;
2355}

2357Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) {
llvm::Value *SelValue = GetSelector(CGF, Sel);

// Store it to a temporary.  Does this satisfy the semantics of
// GetAddrOfSelector?  Hopefully.
Address tmp = CGF.CreateTempAlloca(SelValue->getType(),
                                   CGF.getPointerAlign());
CGF.Builder.CreateStore(SelValue, tmp);
return tmp;
2366}

2368llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) {
return GetTypedSelector(CGF, Sel, std::string());
2370}

2372llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
                                  const ObjCMethodDecl *Method) {
std::string SelTypes = CGM.getContext().getObjCEncodingForMethodDecl(Method);
return GetTypedSelector(CGF, Method->getSelector(), SelTypes);
2376}

2378llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
  // With the old ABI, there was only one kind of catchall, which broke
  // foreign exceptions.  With the new ABI, we use __objc_id_typeinfo as
  // a pointer indicating object catchalls, and NULL to indicate real
  // catchalls
  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
    return MakeConstantString("@id");
  } else {
    return nullptr;
  }
}

// All other types should be Objective-C interface pointer types.
const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>();
assert(OPT && "Invalid @catch type.")(static_cast<void> (0));
const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
assert(IDecl && "Invalid @catch type.")(static_cast<void> (0));
return MakeConstantString(IDecl->getIdentifier()->getName());
2397}

2399llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
if (usesSEHExceptions)
1
Assuming field 'usesSEHExceptions' is false→
2
←
Taking false branch→
  return CGM.getCXXABI().getAddrOfRTTIDescriptor(T);

if (!CGM.getLangOpts().CPlusPlus)
3
←
Assuming field 'CPlusPlus' is not equal to 0→
  return CGObjCGNU::GetEHType(T);

// For Objective-C++, we want to provide the ability to catch both C++ and
// Objective-C objects in the same function.

// There's a particular fixed type info for 'id'.
if (T->isObjCIdType() ||
4
←
Calling 'Type::isObjCIdType'→
8
←
Returning from 'Type::isObjCIdType'→
14
←
Taking false branch→
    T->isObjCQualifiedIdType()) {
9
←
Calling 'Type::isObjCQualifiedIdType'→
13
←
Returning from 'Type::isObjCQualifiedIdType'→
  llvm::Constant *IDEHType =
    CGM.getModule().getGlobalVariable("__objc_id_type_info");
  if (!IDEHType)
    IDEHType =
      new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
                               false,
                               llvm::GlobalValue::ExternalLinkage,
                               nullptr, "__objc_id_type_info");
  return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
}

const ObjCObjectPointerType *PT =
16
←
'PT' initialized to a null pointer value→
  T->getAs<ObjCObjectPointerType>();
15
←
Assuming the object is not a 'ObjCObjectPointerType'→
assert(PT && "Invalid @catch type.")(static_cast<void> (0));
const ObjCInterfaceType *IT = PT->getInterfaceType();
17
←
Called C++ object pointer is null
assert(IT && "Invalid @catch type.")(static_cast<void> (0));
std::string className =
    std::string(IT->getDecl()->getIdentifier()->getName());

std::string typeinfoName = "__objc_eh_typeinfo_" + className;

// Return the existing typeinfo if it exists
llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
if (typeinfo)
  return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);

// Otherwise create it.

// vtable for gnustep::libobjc::__objc_class_type_info
// It's quite ugly hard-coding this.  Ideally we'd generate it using the host
// platform's name mangling.
const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
auto *Vtable = TheModule.getGlobalVariable(vtableName);
if (!Vtable) {
  Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
                                    llvm::GlobalValue::ExternalLinkage,
                                    nullptr, vtableName);
}
llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
auto *BVtable = llvm::ConstantExpr::getBitCast(
    llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
    PtrToInt8Ty);

llvm::Constant *typeName =
  ExportUniqueString(className, "__objc_eh_typename_");

ConstantInitBuilder builder(CGM);
auto fields = builder.beginStruct();
fields.add(BVtable);
fields.add(typeName);
llvm::Constant *TI =
  fields.finishAndCreateGlobal("__objc_eh_typeinfo_" + className,
                               CGM.getPointerAlign(),
                               /*constant*/ false,
                               llvm::GlobalValue::LinkOnceODRLinkage);
return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
2468}

2470/// Generate an NSConstantString object.
2471ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {

std::string Str = SL->getString().str();
CharUnits Align = CGM.getPointerAlign();

// Look for an existing one
llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
if (old != ObjCStrings.end())
  return ConstantAddress(old->getValue(), Align);

StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;

if (StringClass.empty()) StringClass = "NSConstantString";

std::string Sym = "_OBJC_CLASS_";
Sym += StringClass;

llvm::Constant *isa = TheModule.getNamedGlobal(Sym);

if (!isa)
  isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
          llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
else if (isa->getType() != PtrToIdTy)
  isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);

ConstantInitBuilder Builder(CGM);
auto Fields = Builder.beginStruct();
Fields.add(isa);
Fields.add(MakeConstantString(Str));
Fields.addInt(IntTy, Str.size());
llvm::Constant *ObjCStr =
  Fields.finishAndCreateGlobal(".objc_str", Align);
ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
ObjCStrings[Str] = ObjCStr;
ConstantStrings.push_back(ObjCStr);
return ConstantAddress(ObjCStr, Align);
2507}

2509///Generates a message send where the super is the receiver.  This is a message
2510///send to self with special delivery semantics indicating which class's method
2511///should be called.
2512RValue
2513CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
                                  ReturnValueSlot Return,
                                  QualType ResultType,
                                  Selector Sel,
                                  const ObjCInterfaceDecl *Class,
                                  bool isCategoryImpl,
                                  llvm::Value *Receiver,
                                  bool IsClassMessage,
                                  const CallArgList &CallArgs,
                                  const ObjCMethodDecl *Method) {
CGBuilderTy &Builder = CGF.Builder;
if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
  if (Sel == RetainSel || Sel == AutoreleaseSel) {
    return RValue::get(EnforceType(Builder, Receiver,
                CGM.getTypes().ConvertType(ResultType)));
  }
  if (Sel == ReleaseSel) {
    return RValue::get(nullptr);
  }
}

llvm::Value *cmd = GetSelector(CGF, Sel);
CallArgList ActualArgs;

ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
ActualArgs.addFrom(CallArgs);

MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);

llvm::Value *ReceiverClass = nullptr;
bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
if (isV2ABI) {
  ReceiverClass = GetClassNamed(CGF,
      Class->getSuperClass()->getNameAsString(), /*isWeak*/false);
  if (IsClassMessage)  {
    // Load the isa pointer of the superclass is this is a class method.
    ReceiverClass = Builder.CreateBitCast(ReceiverClass,
                                          llvm::PointerType::getUnqual(IdTy));
    ReceiverClass =
      Builder.CreateAlignedLoad(IdTy, ReceiverClass, CGF.getPointerAlign());
  }
  ReceiverClass = EnforceType(Builder, ReceiverClass, IdTy);
} else {
  if (isCategoryImpl) {
    llvm::FunctionCallee classLookupFunction = nullptr;
    if (IsClassMessage)  {
      classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
            IdTy, PtrTy, true), "objc_get_meta_class");
    } else {
      classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
            IdTy, PtrTy, true), "objc_get_class");
    }
    ReceiverClass = Builder.CreateCall(classLookupFunction,
        MakeConstantString(Class->getNameAsString()));
  } else {
    // Set up global aliases for the metaclass or class pointer if they do not
    // already exist.  These will are forward-references which will be set to
    // pointers to the class and metaclass structure created for the runtime
    // load function.  To send a message to super, we look up the value of the
    // super_class pointer from either the class or metaclass structure.
    if (IsClassMessage)  {
      if (!MetaClassPtrAlias) {
        MetaClassPtrAlias = llvm::GlobalAlias::create(
            IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
            ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
      }
      ReceiverClass = MetaClassPtrAlias;
    } else {
      if (!ClassPtrAlias) {
        ClassPtrAlias = llvm::GlobalAlias::create(
            IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
            ".objc_class_ref" + Class->getNameAsString(), &TheModule);
      }
      ReceiverClass = ClassPtrAlias;
    }
  }
  // Cast the pointer to a simplified version of the class structure
  llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy);
  ReceiverClass = Builder.CreateBitCast(ReceiverClass,
                                        llvm::PointerType::getUnqual(CastTy));
  // Get the superclass pointer
  ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1);
  // Load the superclass pointer
  ReceiverClass =
    Builder.CreateAlignedLoad(IdTy, ReceiverClass, CGF.getPointerAlign());
}
// Construct the structure used to look up the IMP
llvm::StructType *ObjCSuperTy =
    llvm::StructType::get(Receiver->getType(), IdTy);

Address ObjCSuper = CGF.CreateTempAlloca(ObjCSuperTy,
                            CGF.getPointerAlign());

Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0));
Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1));

ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);

// Get the IMP
llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
imp = EnforceType(Builder, imp, MSI.MessengerType);

llvm::Metadata *impMD[] = {
    llvm::MDString::get(VMContext, Sel.getAsString()),
    llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
    llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
        llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);

CGCallee callee(CGCalleeInfo(), imp);

llvm::CallBase *call;
RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
call->setMetadata(msgSendMDKind, node);
return msgRet;
2629}

2631/// Generate code for a message send expression.
2632RValue
2633CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
                             ReturnValueSlot Return,
                             QualType ResultType,
                             Selector Sel,
                             llvm::Value *Receiver,
                             const CallArgList &CallArgs,
                             const ObjCInterfaceDecl *Class,
                             const ObjCMethodDecl *Method) {
CGBuilderTy &Builder = CGF.Builder;

// Strip out message sends to retain / release in GC mode
if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
  if (Sel == RetainSel || Sel == AutoreleaseSel) {
    return RValue::get(EnforceType(Builder, Receiver,
                CGM.getTypes().ConvertType(ResultType)));
  }
  if (Sel == ReleaseSel) {
    return RValue::get(nullptr);
  }
}

// If the return type is something that goes in an integer register, the
// runtime will handle 0 returns.  For other cases, we fill in the 0 value
// ourselves.
//
// The language spec says the result of this kind of message send is
// undefined, but lots of people seem to have forgotten to read that
// paragraph and insist on sending messages to nil that have structure
// returns.  With GCC, this generates a random return value (whatever happens
// to be on the stack / in those registers at the time) on most platforms,
// and generates an illegal instruction trap on SPARC.  With LLVM it corrupts
// the stack.
bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
    ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());

llvm::BasicBlock *startBB = nullptr;
llvm::BasicBlock *messageBB = nullptr;
llvm::BasicBlock *continueBB = nullptr;

if (!isPointerSizedReturn) {
  startBB = Builder.GetInsertBlock();
  messageBB = CGF.createBasicBlock("msgSend");
  continueBB = CGF.createBasicBlock("continue");

  llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
          llvm::Constant::getNullValue(Receiver->getType()));
  Builder.CreateCondBr(isNil, continueBB, messageBB);
  CGF.EmitBlock(messageBB);
}

IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
llvm::Value *cmd;
if (Method)
  cmd = GetSelector(CGF, Method);
else
  cmd = GetSelector(CGF, Sel);
cmd = EnforceType(Builder, cmd, SelectorTy);
Receiver = EnforceType(Builder, Receiver, IdTy);

llvm::Metadata *impMD[] = {
    llvm::MDString::get(VMContext, Sel.getAsString()),
    llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
    llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
        llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);

CallArgList ActualArgs;
ActualArgs.add(RValue::get(Receiver), ASTIdTy);
ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
ActualArgs.addFrom(CallArgs);

MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);

// Get the IMP to call
llvm::Value *imp;

// If we have non-legacy dispatch specified, we try using the objc_msgSend()
// functions.  These are not supported on all platforms (or all runtimes on a
// given platform), so we
switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
  case CodeGenOptions::Legacy:
    imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
    break;
  case CodeGenOptions::Mixed:
  case CodeGenOptions::NonLegacy:
    if (CGM.ReturnTypeUsesFPRet(ResultType)) {
      imp =
          CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
                                    "objc_msgSend_fpret")
              .getCallee();
    } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
      // The actual types here don't matter - we're going to bitcast the
      // function anyway
      imp =
          CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
                                    "objc_msgSend_stret")
              .getCallee();
    } else {
      imp = CGM.CreateRuntimeFunction(
                   llvm::FunctionType::get(IdTy, IdTy, true), "objc_msgSend")
                .getCallee();
    }
}

// Reset the receiver in case the lookup modified it
ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy);

imp = EnforceType(Builder, imp, MSI.MessengerType);

llvm::CallBase *call;
CGCallee callee(CGCalleeInfo(), imp);
RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
call->setMetadata(msgSendMDKind, node);


if (!isPointerSizedReturn) {
  messageBB = CGF.Builder.GetInsertBlock();
  CGF.Builder.CreateBr(continueBB);
  CGF.EmitBlock(continueBB);
  if (msgRet.isScalar()) {
    llvm::Value *v = msgRet.getScalarVal();
    llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
    phi->addIncoming(v, messageBB);
    phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
    msgRet = RValue::get(phi);
  } else if (msgRet.isAggregate()) {
    Address v = msgRet.getAggregateAddress();
    llvm::PHINode *phi = Builder.CreatePHI(v.getType(), 2);
    llvm::Type *RetTy = v.getElementType();
    Address NullVal = CGF.CreateTempAlloca(RetTy, v.getAlignment(), "null");
    CGF.InitTempAlloca(NullVal, llvm::Constant::getNullValue(RetTy));
    phi->addIncoming(v.getPointer(), messageBB);
    phi->addIncoming(NullVal.getPointer(), startBB);
    msgRet = RValue::getAggregate(Address(phi, v.getAlignment()));
  } else /* isComplex() */ {
    std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
    llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
    phi->addIncoming(v.first, messageBB);
    phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
        startBB);
    llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
    phi2->addIncoming(v.second, messageBB);
    phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
        startBB);
    msgRet = RValue::getComplex(phi, phi2);
  }
}
return msgRet;
2781}

2783/// Generates a MethodList.  Used in construction of a objc_class and
2784/// objc_category structures.
2785llvm::Constant *CGObjCGNU::
2786GenerateMethodList(StringRef ClassName,
                 StringRef CategoryName,
                 ArrayRef<const ObjCMethodDecl*> Methods,
                 bool isClassMethodList) {
if (Methods.empty())
  return NULLPtr;

ConstantInitBuilder Builder(CGM);

auto MethodList = Builder.beginStruct();
MethodList.addNullPointer(CGM.Int8PtrTy);
MethodList.addInt(Int32Ty, Methods.size());

// Get the method structure type.
llvm::StructType *ObjCMethodTy =
  llvm::StructType::get(CGM.getLLVMContext(), {
    PtrToInt8Ty, // Really a selector, but the runtime creates it us.
    PtrToInt8Ty, // Method types
    IMPTy        // Method pointer
  });
bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
if (isV2ABI) {
  // size_t size;
  llvm::DataLayout td(&TheModule);
  MethodList.addInt(SizeTy, td.getTypeSizeInBits(ObjCMethodTy) /
      CGM.getContext().getCharWidth());
  ObjCMethodTy =
    llvm::StructType::get(CGM.getLLVMContext(), {
      IMPTy,       // Method pointer
      PtrToInt8Ty, // Selector
      PtrToInt8Ty  // Extended type encoding
    });
} else {
  ObjCMethodTy =
    llvm::StructType::get(CGM.getLLVMContext(), {
      PtrToInt8Ty, // Really a selector, but the runtime creates it us.
      PtrToInt8Ty, // Method types
      IMPTy        // Method pointer
    });
}
auto MethodArray = MethodList.beginArray();
ASTContext &Context = CGM.getContext();
for (const auto *OMD : Methods) {
  llvm::Constant *FnPtr =
    TheModule.getFunction(getSymbolNameForMethod(OMD));
  assert(FnPtr && "Can't generate metadata for method that doesn't exist")(static_cast<void> (0));
  auto Method = MethodArray.beginStruct(ObjCMethodTy);
  if (isV2ABI) {
    Method.addBitCast(FnPtr, IMPTy);
    Method.add(GetConstantSelector(OMD->getSelector(),
        Context.getObjCEncodingForMethodDecl(OMD)));
    Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD, true)));
  } else {
    Method.add(MakeConstantString(OMD->getSelector().getAsString()));
    Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD)));
    Method.addBitCast(FnPtr, IMPTy);
  }
  Method.finishAndAddTo(MethodArray);
}
MethodArray.finishAndAddTo(MethodList);

// Create an instance of the structure
return MethodList.finishAndCreateGlobal(".objc_method_list",
                                        CGM.getPointerAlign());
2850}

2852/// Generates an IvarList.  Used in construction of a objc_class.
2853llvm::Constant *CGObjCGNU::
2854GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
               ArrayRef<llvm::Constant *> IvarTypes,
               ArrayRef<llvm::Constant *> IvarOffsets,
               ArrayRef<llvm::Constant *> IvarAlign,
               ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) {
if (IvarNames.empty())
  return NULLPtr;

ConstantInitBuilder Builder(CGM);

// Structure containing array count followed by array.
auto IvarList = Builder.beginStruct();
IvarList.addInt(IntTy, (int)IvarNames.size());

// Get the ivar structure type.
llvm::StructType *ObjCIvarTy =
    llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy);

// Array of ivar structures.
auto Ivars = IvarList.beginArray(ObjCIvarTy);
for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
  auto Ivar = Ivars.beginStruct(ObjCIvarTy);
  Ivar.add(IvarNames[i]);
  Ivar.add(IvarTypes[i]);
  Ivar.add(IvarOffsets[i]);
  Ivar.finishAndAddTo(Ivars);
}
Ivars.finishAndAddTo(IvarList);

// Create an instance of the structure
return IvarList.finishAndCreateGlobal(".objc_ivar_list",
                                      CGM.getPointerAlign());
2886}

2888/// Generate a class structure
2889llvm::Constant *CGObjCGNU::GenerateClassStructure(
  llvm::Constant *MetaClass,
  llvm::Constant *SuperClass,
  unsigned info,
  const char *Name,
  llvm::Constant *Version,
  llvm::Constant *InstanceSize,
  llvm::Constant *IVars,
  llvm::Constant *Methods,
  llvm::Constant *Protocols,
  llvm::Constant *IvarOffsets,
  llvm::Constant *Properties,
  llvm::Constant *StrongIvarBitmap,
  llvm::Constant *WeakIvarBitmap,
  bool isMeta) {
// Set up the class structure
// Note:  Several of these are char*s when they should be ids.  This is
// because the runtime performs this translation on load.
//
// Fields marked New ABI are part of the GNUstep runtime.  We emit them
// anyway; the classes will still work with the GNU runtime, they will just
// be ignored.
llvm::StructType *ClassTy = llvm::StructType::get(
    PtrToInt8Ty,        // isa
    PtrToInt8Ty,        // super_class
    PtrToInt8Ty,        // name
    LongTy,             // version
    LongTy,             // info
    LongTy,             // instance_size
    IVars->getType(),   // ivars
    Methods->getType(), // methods
    // These are all filled in by the runtime, so we pretend
    PtrTy, // dtable
    PtrTy, // subclass_list
    PtrTy, // sibling_class
    PtrTy, // protocols
    PtrTy, // gc_object_type
    // New ABI:
    LongTy,                 // abi_version
    IvarOffsets->getType(), // ivar_offsets
    Properties->getType(),  // properties
    IntPtrTy,               // strong_pointers
    IntPtrTy                // weak_pointers
    );

ConstantInitBuilder Builder(CGM);
auto Elements = Builder.beginStruct(ClassTy);

// Fill in the structure

// isa
Elements.addBitCast(MetaClass, PtrToInt8Ty);
// super_class
Elements.add(SuperClass);
// name
Elements.add(MakeConstantString(Name, ".class_name"));
// version
Elements.addInt(LongTy, 0);
// info
Elements.addInt(LongTy, info);
// instance_size
if (isMeta) {
  llvm::DataLayout td(&TheModule);
  Elements.addInt(LongTy,
                  td.getTypeSizeInBits(ClassTy) /
                    CGM.getContext().getCharWidth());
} else
  Elements.add(InstanceSize);
// ivars
Elements.add(IVars);
// methods
Elements.add(Methods);
// These are all filled in by the runtime, so we pretend
// dtable
Elements.add(NULLPtr);
// subclass_list
Elements.add(NULLPtr);
// sibling_class
Elements.add(NULLPtr);
// protocols
Elements.addBitCast(Protocols, PtrTy);
// gc_object_type
Elements.add(NULLPtr);
// abi_version
Elements.addInt(LongTy, ClassABIVersion);
// ivar_offsets
Elements.add(IvarOffsets);
// properties
Elements.add(Properties);
// strong_pointers
Elements.add(StrongIvarBitmap);
// weak_pointers
Elements.add(WeakIvarBitmap);
// Create an instance of the structure
// This is now an externally visible symbol, so that we can speed up class
// messages in the next ABI.  We may already have some weak references to
// this, so check and fix them properly.
std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
        std::string(Name));
llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
llvm::Constant *Class =
  Elements.finishAndCreateGlobal(ClassSym, CGM.getPointerAlign(), false,
                                 llvm::GlobalValue::ExternalLinkage);
if (ClassRef) {
  ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
                ClassRef->getType()));
  ClassRef->removeFromParent();
  Class->setName(ClassSym);
}
return Class;
2999}

3001llvm::Constant *CGObjCGNU::
3002GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) {
// Get the method structure type.
llvm::StructType *ObjCMethodDescTy =
  llvm::StructType::get(CGM.getLLVMContext(), { PtrToInt8Ty, PtrToInt8Ty });
ASTContext &Context = CGM.getContext();
ConstantInitBuilder Builder(CGM);
auto MethodList = Builder.beginStruct();
MethodList.addInt(IntTy, Methods.size());
auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
for (auto *M : Methods) {
  auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
  Method.add(MakeConstantString(M->getSelector().getAsString()));
  Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(M)));
  Method.finishAndAddTo(MethodArray);
}
MethodArray.finishAndAddTo(MethodList);
return MethodList.finishAndCreateGlobal(".objc_method_list",
                                        CGM.getPointerAlign());
3020}

3022// Create the protocol list structure used in classes, categories and so on
3023llvm::Constant *
3024CGObjCGNU::GenerateProtocolList(ArrayRef<std::string> Protocols) {

ConstantInitBuilder Builder(CGM);
auto ProtocolList = Builder.beginStruct();
ProtocolList.add(NULLPtr);
ProtocolList.addInt(LongTy, Protocols.size());

auto Elements = ProtocolList.beginArray(PtrToInt8Ty);
for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
    iter != endIter ; iter++) {
  llvm::Constant *protocol = nullptr;
  llvm::StringMap<llvm::Constant*>::iterator value =
    ExistingProtocols.find(*iter);
  if (value == ExistingProtocols.end()) {
    protocol = GenerateEmptyProtocol(*iter);
  } else {
    protocol = value->getValue();
  }
  Elements.addBitCast(protocol, PtrToInt8Ty);
}
Elements.finishAndAddTo(ProtocolList);
return ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
                                          CGM.getPointerAlign());
3047}

3049llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF,
                                          const ObjCProtocolDecl *PD) {
auto protocol = GenerateProtocolRef(PD);
llvm::Type *T =
    CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
3055}

3057llvm::Constant *CGObjCGNU::GenerateProtocolRef(const ObjCProtocolDecl *PD) {
llvm::Constant *&protocol = ExistingProtocols[PD->getNameAsString()];
if (!protocol)
  GenerateProtocol(PD);
assert(protocol && "Unknown protocol")(static_cast<void> (0));
return protocol;
3063}

3065llvm::Constant *
3066CGObjCGNU::GenerateEmptyProtocol(StringRef ProtocolName) {
llvm::Constant *ProtocolList = GenerateProtocolList({});
llvm::Constant *MethodList = GenerateProtocolMethodList({});
MethodList = llvm::ConstantExpr::getBitCast(MethodList, PtrToInt8Ty);
// Protocols are objects containing lists of the methods implemented and
// protocols adopted.
ConstantInitBuilder Builder(CGM);
auto Elements = Builder.beginStruct();

// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
Elements.add(llvm::ConstantExpr::getIntToPtr(
        llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));

Elements.add(MakeConstantString(ProtocolName, ".objc_protocol_name"));
Elements.add(ProtocolList); /* .protocol_list */
Elements.add(MethodList);   /* .instance_methods */
Elements.add(MethodList);   /* .class_methods */
Elements.add(MethodList);   /* .optional_instance_methods */
Elements.add(MethodList);   /* .optional_class_methods */
Elements.add(NULLPtr);      /* .properties */
Elements.add(NULLPtr);      /* .optional_properties */
return Elements.finishAndCreateGlobal(SymbolForProtocol(ProtocolName),
                                      CGM.getPointerAlign());
3090}

3092void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
if (PD->isNonRuntimeProtocol())
  return;

std::string ProtocolName = PD->getNameAsString();

// Use the protocol definition, if there is one.
if (const ObjCProtocolDecl *Def = PD->getDefinition())
  PD = Def;

SmallVector<std::string, 16> Protocols;
for (const auto *PI : PD->protocols())
  Protocols.push_back(PI->getNameAsString());
SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
SmallVector<const ObjCMethodDecl*, 16> OptionalInstanceMethods;
for (const auto *I : PD->instance_methods())
  if (I->isOptional())
    OptionalInstanceMethods.push_back(I);
  else
    InstanceMethods.push_back(I);
// Collect information about class methods:
SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
SmallVector<const ObjCMethodDecl*, 16> OptionalClassMethods;
for (const auto *I : PD->class_methods())
  if (I->isOptional())
    OptionalClassMethods.push_back(I);
  else
    ClassMethods.push_back(I);

llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
llvm::Constant *InstanceMethodList =
  GenerateProtocolMethodList(InstanceMethods);
llvm::Constant *ClassMethodList =
  GenerateProtocolMethodList(ClassMethods);
llvm::Constant *OptionalInstanceMethodList =
  GenerateProtocolMethodList(OptionalInstanceMethods);
llvm::Constant *OptionalClassMethodList =
  GenerateProtocolMethodList(OptionalClassMethods);

// Property metadata: name, attributes, isSynthesized, setter name, setter
// types, getter name, getter types.
// The isSynthesized value is always set to 0 in a protocol.  It exists to
// simplify the runtime library by allowing it to use the same data
// structures for protocol metadata everywhere.

llvm::Constant *PropertyList =
  GeneratePropertyList(nullptr, PD, false, false);
llvm::Constant *OptionalPropertyList =
  GeneratePropertyList(nullptr, PD, false, true);

// Protocols are objects containing lists of the methods implemented and
// protocols adopted.
// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
ConstantInitBuilder Builder(CGM);
auto Elements = Builder.beginStruct();
Elements.add(
    llvm::ConstantExpr::getIntToPtr(
        llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
Elements.add(MakeConstantString(ProtocolName));
Elements.add(ProtocolList);
Elements.add(InstanceMethodList);
Elements.add(ClassMethodList);
Elements.add(OptionalInstanceMethodList);
Elements.add(OptionalClassMethodList);
Elements.add(PropertyList);
Elements.add(OptionalPropertyList);
ExistingProtocols[ProtocolName] =
  llvm::ConstantExpr::getBitCast(
    Elements.finishAndCreateGlobal(".objc_protocol", CGM.getPointerAlign()),
    IdTy);
3163}
3164void CGObjCGNU::GenerateProtocolHolderCategory() {
// Collect information about instance methods

ConstantInitBuilder Builder(CGM);
auto Elements = Builder.beginStruct();

const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
const std::string CategoryName = "AnotherHack";
Elements.add(MakeConstantString(CategoryName));
Elements.add(MakeConstantString(ClassName));
// Instance method list
Elements.addBitCast(GenerateMethodList(
        ClassName, CategoryName, {}, false), PtrTy);
// Class method list
Elements.addBitCast(GenerateMethodList(
        ClassName, CategoryName, {}, true), PtrTy);

// Protocol list
ConstantInitBuilder ProtocolListBuilder(CGM);
auto ProtocolList = ProtocolListBuilder.beginStruct();
ProtocolList.add(NULLPtr);
ProtocolList.addInt(LongTy, ExistingProtocols.size());
auto ProtocolElements = ProtocolList.beginArray(PtrTy);
for (auto iter = ExistingProtocols.begin(), endIter = ExistingProtocols.end();
     iter != endIter ; iter++) {
  ProtocolElements.addBitCast(iter->getValue(), PtrTy);
}
ProtocolElements.finishAndAddTo(ProtocolList);
Elements.addBitCast(
                 ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
                                                    CGM.getPointerAlign()),
                 PtrTy);
Categories.push_back(llvm::ConstantExpr::getBitCast(
      Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
      PtrTy));
3199}

3201/// Libobjc2 uses a bitfield representation where small(ish) bitfields are
3202/// stored in a 64-bit value with the low bit set to 1 and the remaining 63
3203/// bits set to their values, LSB first, while larger ones are stored in a
3204/// structure of this / form:
3205///
3206/// struct { int32_t length; int32_t values[length]; };
3207///
3208/// The values in the array are stored in host-endian format, with the least
3209/// significant bit being assumed to come first in the bitfield.  Therefore, a
3210/// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
3211/// bitfield / with the 63rd bit set will be 1<<64.
3212llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
int bitCount = bits.size();
int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
if (bitCount < ptrBits) {
  uint64_t val = 1;
  for (int i=0 ; i<bitCount ; ++i) {
    if (bits[i]) val |= 1ULL<<(i+1);
  }
  return llvm::ConstantInt::get(IntPtrTy, val);
}
SmallVector<llvm::Constant *, 8> values;
int v=0;
while (v < bitCount) {
  int32_t word = 0;
  for (int i=0 ; (i<32) && (v<bitCount)  ; ++i) {
    if (bits[v]) word |= 1<<i;
    v++;
  }
  values.push_back(llvm::ConstantInt::get(Int32Ty, word));
}

ConstantInitBuilder builder(CGM);
auto fields = builder.beginStruct();
fields.addInt(Int32Ty, values.size());
auto array = fields.beginArray();
for (auto v : values) array.add(v);
array.finishAndAddTo(fields);

llvm::Constant *GS =
  fields.finishAndCreateGlobal("", CharUnits::fromQuantity(4));
llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
return ptr;
3244}

3246llvm::Constant *CGObjCGNU::GenerateCategoryProtocolList(const
  ObjCCategoryDecl *OCD) {
const auto &RefPro = OCD->getReferencedProtocols();
const auto RuntimeProtos =
    GetRuntimeProtocolList(RefPro.begin(), RefPro.end());
SmallVector<std::string, 16> Protocols;
for (const auto *PD : RuntimeProtos)
  Protocols.push_back(PD->getNameAsString());
return GenerateProtocolList(Protocols);
3255}

3257void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
const ObjCInterfaceDecl *Class = OCD->getClassInterface();
std::string ClassName = Class->getNameAsString();
std::string CategoryName = OCD->getNameAsString();

// Collect the names of referenced protocols
const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();

ConstantInitBuilder Builder(CGM);
auto Elements = Builder.beginStruct();
Elements.add(MakeConstantString(CategoryName));
Elements.add(MakeConstantString(ClassName));
// Instance method list
SmallVector<ObjCMethodDecl*, 16> InstanceMethods;
InstanceMethods.insert(InstanceMethods.begin(), OCD->instmeth_begin(),
    OCD->instmeth_end());
Elements.addBitCast(
        GenerateMethodList(ClassName, CategoryName, InstanceMethods, false),
        PtrTy);
// Class method list

SmallVector<ObjCMethodDecl*, 16> ClassMethods;
ClassMethods.insert(ClassMethods.begin(), OCD->classmeth_begin(),
    OCD->classmeth_end());
Elements.addBitCast(
        GenerateMethodList(ClassName, CategoryName, ClassMethods, true),
        PtrTy);
// Protocol list
Elements.addBitCast(GenerateCategoryProtocolList(CatDecl), PtrTy);
if (isRuntime(ObjCRuntime::GNUstep, 2)) {
  const ObjCCategoryDecl *Category =
    Class->FindCategoryDeclaration(OCD->getIdentifier());
  if (Category) {
    // Instance properties
    Elements.addBitCast(GeneratePropertyList(OCD, Category, false), PtrTy);
    // Class properties
    Elements.addBitCast(GeneratePropertyList(OCD, Category, true), PtrTy);
  } else {
    Elements.addNullPointer(PtrTy);
    Elements.addNullPointer(PtrTy);
  }
}

Categories.push_back(llvm::ConstantExpr::getBitCast(
      Elements.finishAndCreateGlobal(
        std::string(".objc_category_")+ClassName+CategoryName,
        CGM.getPointerAlign()),
      PtrTy));
3305}

3307llvm::Constant *CGObjCGNU::GeneratePropertyList(const Decl *Container,
  const ObjCContainerDecl *OCD,
  bool isClassProperty,
  bool protocolOptionalProperties) {

SmallVector<const ObjCPropertyDecl *, 16> Properties;
llvm::SmallPtrSet<const IdentifierInfo*, 16> PropertySet;
bool isProtocol = isa<ObjCProtocolDecl>(OCD);
ASTContext &Context = CGM.getContext();

std::function<void(const ObjCProtocolDecl *Proto)> collectProtocolProperties
  = [&](const ObjCProtocolDecl *Proto) {
    for (const auto *P : Proto->protocols())
      collectProtocolProperties(P);
    for (const auto *PD : Proto->properties()) {
      if (isClassProperty != PD->isClassProperty())
        continue;
      // Skip any properties that are declared in protocols that this class
      // conforms to but are not actually implemented by this class.
      if (!isProtocol && !Context.getObjCPropertyImplDeclForPropertyDecl(PD, Container))
        continue;
      if (!PropertySet.insert(PD->getIdentifier()).second)
        continue;
      Properties.push_back(PD);
    }
  };

if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
  for (const ObjCCategoryDecl *ClassExt : OID->known_extensions())
    for (auto *PD : ClassExt->properties()) {
      if (isClassProperty != PD->isClassProperty())
        continue;
      PropertySet.insert(PD->getIdentifier());
      Properties.push_back(PD);
    }

for (const auto *PD : OCD->properties()) {
  if (isClassProperty != PD->isClassProperty())
    continue;
  // If we're generating a list for a protocol, skip optional / required ones
  // when generating the other list.
  if (isProtocol && (protocolOptionalProperties != PD->isOptional()))
    continue;
  // Don't emit duplicate metadata for properties that were already in a
  // class extension.
  if (!PropertySet.insert(PD->getIdentifier()).second)
    continue;

  Properties.push_back(PD);
}

if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
  for (const auto *P : OID->all_referenced_protocols())
    collectProtocolProperties(P);
else if (const ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(OCD))
  for (const auto *P : CD->protocols())
    collectProtocolProperties(P);

auto numProperties = Properties.size();

if (numProperties == 0)
  return NULLPtr;

ConstantInitBuilder builder(CGM);
auto propertyList = builder.beginStruct();
auto properties = PushPropertyListHeader(propertyList, numProperties);

// Add all of the property methods need adding to the method list and to the
// property metadata list.
for (auto *property : Properties) {
  bool isSynthesized = false;
  bool isDynamic = false;
  if (!isProtocol) {
    auto *propertyImpl = Context.getObjCPropertyImplDeclForPropertyDecl(property, Container);
    if (propertyImpl) {
      isSynthesized = (propertyImpl->getPropertyImplementation() ==
          ObjCPropertyImplDecl::Synthesize);
      isDynamic = (propertyImpl->getPropertyImplementation() ==
          ObjCPropertyImplDecl::Dynamic);
    }
  }
  PushProperty(properties, property, Container, isSynthesized, isDynamic);
}
properties.finishAndAddTo(propertyList);

return propertyList.finishAndCreateGlobal(".objc_property_list",
                                          CGM.getPointerAlign());
3394}

3396void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
// Get the class declaration for which the alias is specified.
ObjCInterfaceDecl *ClassDecl =
  const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
ClassAliases.emplace_back(ClassDecl->getNameAsString(),
                          OAD->getNameAsString());
3402}

3404void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
ASTContext &Context = CGM.getContext();

// Get the superclass name.
const ObjCInterfaceDecl * SuperClassDecl =
  OID->getClassInterface()->getSuperClass();
std::string SuperClassName;
if (SuperClassDecl) {
  SuperClassName = SuperClassDecl->getNameAsString();
  EmitClassRef(SuperClassName);
}

// Get the class name
ObjCInterfaceDecl *ClassDecl =
    const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
std::string ClassName = ClassDecl->getNameAsString();

// Emit the symbol that is used to generate linker errors if this class is
// referenced in other modules but not declared.
std::string classSymbolName = "__objc_class_name_" + ClassName;
if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
  symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
} else {
  new llvm::GlobalVariable(TheModule, LongTy, false,
                           llvm::GlobalValue::ExternalLinkage,
                           llvm::ConstantInt::get(LongTy, 0),
                           classSymbolName);
}

// Get the size of instances.
int instanceSize =
  Context.getASTObjCImplementationLayout(OID).getSize().getQuantity();

// Collect information about instance variables.
SmallVector<llvm::Constant*, 16> IvarNames;
SmallVector<llvm::Constant*, 16> IvarTypes;
SmallVector<llvm::Constant*, 16> IvarOffsets;
SmallVector<llvm::Constant*, 16> IvarAligns;
SmallVector<Qualifiers::ObjCLifetime, 16> IvarOwnership;

ConstantInitBuilder IvarOffsetBuilder(CGM);
auto IvarOffsetValues = IvarOffsetBuilder.beginArray(PtrToIntTy);
SmallVector<bool, 16> WeakIvars;
SmallVector<bool, 16> StrongIvars;

int superInstanceSize = !SuperClassDecl ? 0 :
  Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
// For non-fragile ivars, set the instance size to 0 - {the size of just this
// class}.  The runtime will then set this to the correct value on load.
if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
  instanceSize = 0 - (instanceSize - superInstanceSize);
}

for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
     IVD = IVD->getNextIvar()) {
    // Store the name
    IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
    // Get the type encoding for this ivar
    std::string TypeStr;
    Context.getObjCEncodingForType(IVD->getType(), TypeStr, IVD);
    IvarTypes.push_back(MakeConstantString(TypeStr));
    IvarAligns.push_back(llvm::ConstantInt::get(IntTy,
          Context.getTypeSize(IVD->getType())));
    // Get the offset
    uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
    uint64_t Offset = BaseOffset;
    if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
      Offset = BaseOffset - superInstanceSize;
    }
    llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
    // Create the direct offset value
    std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
        IVD->getNameAsString();

    llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
    if (OffsetVar) {
      OffsetVar->setInitializer(OffsetValue);
      // If this is the real definition, change its linkage type so that
      // different modules will use this one, rather than their private
      // copy.
      OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
    } else
      OffsetVar = new llvm::GlobalVariable(TheModule, Int32Ty,
        false, llvm::GlobalValue::ExternalLinkage,
        OffsetValue, OffsetName);
    IvarOffsets.push_back(OffsetValue);
    IvarOffsetValues.add(OffsetVar);
    Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
    IvarOwnership.push_back(lt);
    switch (lt) {
      case Qualifiers::OCL_Strong:
        StrongIvars.push_back(true);
        WeakIvars.push_back(false);
        break;
      case Qualifiers::OCL_Weak:
        StrongIvars.push_back(false);
        WeakIvars.push_back(true);
        break;
      default:
        StrongIvars.push_back(false);
        WeakIvars.push_back(false);
    }
}
llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
llvm::GlobalVariable *IvarOffsetArray =
  IvarOffsetValues.finishAndCreateGlobal(".ivar.offsets",
                                         CGM.getPointerAlign());

// Collect information about instance methods
SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
    OID->instmeth_end());

SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
    OID->classmeth_end());

llvm::Constant *Properties = GeneratePropertyList(OID, ClassDecl);

// Collect the names of referenced protocols
auto RefProtocols = ClassDecl->protocols();
auto RuntimeProtocols =
    GetRuntimeProtocolList(RefProtocols.begin(), RefProtocols.end());
SmallVector<std::string, 16> Protocols;
for (const auto *I : RuntimeProtocols)
  Protocols.push_back(I->getNameAsString());

// Get the superclass pointer.
llvm::Constant *SuperClass;
if (!SuperClassName.empty()) {
  SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
} else {
  SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
}
// Empty vector used to construct empty method lists
SmallVector<llvm::Constant*, 1>  empty;
// Generate the method and instance variable lists
llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
    InstanceMethods, false);
llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
    ClassMethods, true);
llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
    IvarOffsets, IvarAligns, IvarOwnership);
// Irrespective of whether we are compiling for a fragile or non-fragile ABI,
// we emit a symbol containing the offset for each ivar in the class.  This
// allows code compiled for the non-Fragile ABI to inherit from code compiled
// for the legacy ABI, without causing problems.  The converse is also
// possible, but causes all ivar accesses to be fragile.

// Offset pointer for getting at the correct field in the ivar list when
// setting up the alias.  These are: The base address for the global, the
// ivar array (second field), the ivar in this list (set for each ivar), and
// the offset (third field in ivar structure)
llvm::Type *IndexTy = Int32Ty;
llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
    llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 2 : 1), nullptr,
    llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 3 : 2) };

unsigned ivarIndex = 0;
for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
     IVD = IVD->getNextIvar()) {
    const std::string Name = GetIVarOffsetVariableName(ClassDecl, IVD);
    offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
    // Get the correct ivar field
    llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
        cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
        offsetPointerIndexes);
    // Get the existing variable, if one exists.
    llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
    if (offset) {
      offset->setInitializer(offsetValue);
      // If this is the real definition, change its linkage type so that
      // different modules will use this one, rather than their private
      // copy.
      offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
    } else
      // Add a new alias if there isn't one already.
      new llvm::GlobalVariable(TheModule, offsetValue->getType(),
              false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
    ++ivarIndex;
}
llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);

//Generate metaclass for class methods
llvm::Constant *MetaClassStruct = GenerateClassStructure(
    NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
    NULLPtr, ClassMethodList, NULLPtr, NULLPtr,
    GeneratePropertyList(OID, ClassDecl, true), ZeroPtr, ZeroPtr, true);
CGM.setGVProperties(cast<llvm::GlobalValue>(MetaClassStruct),
                    OID->getClassInterface());

// Generate the class structure
llvm::Constant *ClassStruct = GenerateClassStructure(
    MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
    llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
    GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
    StrongIvarBitmap, WeakIvarBitmap);
CGM.setGVProperties(cast<llvm::GlobalValue>(ClassStruct),
                    OID->getClassInterface());

// Resolve the class aliases, if they exist.
if (ClassPtrAlias) {
  ClassPtrAlias->replaceAllUsesWith(
      llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
  ClassPtrAlias->eraseFromParent();
  ClassPtrAlias = nullptr;
}
if (MetaClassPtrAlias) {
  MetaClassPtrAlias->replaceAllUsesWith(
      llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
  MetaClassPtrAlias->eraseFromParent();
  MetaClassPtrAlias = nullptr;
}

// Add class structure to list to be added to the symtab later
ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
Classes.push_back(ClassStruct);
3622}

3624llvm::Function *CGObjCGNU::ModuleInitFunction() {
// Only emit an ObjC load function if no Objective-C stuff has been called
if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
    ExistingProtocols.empty() && SelectorTable.empty())
  return nullptr;

// Add all referenced protocols to a category.
GenerateProtocolHolderCategory();

llvm::StructType *selStructTy =
  dyn_cast<llvm::StructType>(SelectorTy->getElementType());
llvm::Type *selStructPtrTy = SelectorTy;
if (!selStructTy) {
  selStructTy = llvm::StructType::get(CGM.getLLVMContext(),
                                      { PtrToInt8Ty, PtrToInt8Ty });
  selStructPtrTy = llvm::PointerType::getUnqual(selStructTy);
}

// Generate statics list:
llvm::Constant *statics = NULLPtr;
if (!ConstantStrings.empty()) {
  llvm::GlobalVariable *fileStatics = [&] {
    ConstantInitBuilder builder(CGM);
    auto staticsStruct = builder.beginStruct();

    StringRef stringClass = CGM.getLangOpts().ObjCConstantStringClass;
    if (stringClass.empty()) stringClass = "NXConstantString";
    staticsStruct.add(MakeConstantString(stringClass,
                                         ".objc_static_class_name"));

    auto array = staticsStruct.beginArray();
    array.addAll(ConstantStrings);
    array.add(NULLPtr);
    array.finishAndAddTo(staticsStruct);

    return staticsStruct.finishAndCreateGlobal(".objc_statics",
                                               CGM.getPointerAlign());
  }();

  ConstantInitBuilder builder(CGM);
  auto allStaticsArray = builder.beginArray(fileStatics->getType());
  allStaticsArray.add(fileStatics);
  allStaticsArray.addNullPointer(fileStatics->getType());

  statics = allStaticsArray.finishAndCreateGlobal(".objc_statics_ptr",
                                                  CGM.getPointerAlign());
  statics = llvm::ConstantExpr::getBitCast(statics, PtrTy);
}

// Array of classes, categories, and constant objects.

SmallVector<llvm::GlobalAlias*, 16> selectorAliases;
unsigned selectorCount;

// Pointer to an array of selectors used in this module.
llvm::GlobalVariable *selectorList = [&] {
  ConstantInitBuilder builder(CGM);
  auto selectors = builder.beginArray(selStructTy);
  auto &table = SelectorTable; // MSVC workaround
  std::vector<Selector> allSelectors;
  for (auto &entry : table)
    allSelectors.push_back(entry.first);
  llvm::sort(allSelectors);

  for (auto &untypedSel : allSelectors) {
    std::string selNameStr = untypedSel.getAsString();
    llvm::Constant *selName = ExportUniqueString(selNameStr, ".objc_sel_name");

    for (TypedSelector &sel : table[untypedSel]) {
      llvm::Constant *selectorTypeEncoding = NULLPtr;
      if (!sel.first.empty())
        selectorTypeEncoding =
          MakeConstantString(sel.first, ".objc_sel_types");

      auto selStruct = selectors.beginStruct(selStructTy);
      selStruct.add(selName);
      selStruct.add(selectorTypeEncoding);
      selStruct.finishAndAddTo(selectors);

      // Store the selector alias for later replacement
      selectorAliases.push_back(sel.second);
    }
  }

  // Remember the number of entries in the selector table.
  selectorCount = selectors.size();

  // NULL-terminate the selector list.  This should not actually be required,
  // because the selector list has a length field.  Unfortunately, the GCC
  // runtime decides to ignore the length field and expects a NULL terminator,
  // and GCC cooperates with this by always setting the length to 0.
  auto selStruct = selectors.beginStruct(selStructTy);
  selStruct.add(NULLPtr);
  selStruct.add(NULLPtr);
  selStruct.finishAndAddTo(selectors);

  return selectors.finishAndCreateGlobal(".objc_selector_list",
                                         CGM.getPointerAlign());
}();

// Now that all of the static selectors exist, create pointers to them.
for (unsigned i = 0; i < selectorCount; ++i) {
  llvm::Constant *idxs[] = {
    Zeros[0],
    llvm::ConstantInt::get(Int32Ty, i)
  };
  // FIXME: We're generating redundant loads and stores here!
  llvm::Constant *selPtr = llvm::ConstantExpr::getGetElementPtr(
      selectorList->getValueType(), selectorList, idxs);
  // If selectors are defined as an opaque type, cast the pointer to this
  // type.
  selPtr = llvm::ConstantExpr::getBitCast(selPtr, SelectorTy);
  selectorAliases[i]->replaceAllUsesWith(selPtr);
  selectorAliases[i]->eraseFromParent();
}

llvm::GlobalVariable *symtab = [&] {
  ConstantInitBuilder builder(CGM);
  auto symtab = builder.beginStruct();

  // Number of static selectors
  symtab.addInt(LongTy, selectorCount);

  symtab.addBitCast(selectorList, selStructPtrTy);

  // Number of classes defined.
  symtab.addInt(CGM.Int16Ty, Classes.size());
  // Number of categories defined
  symtab.addInt(CGM.Int16Ty, Categories.size());

  // Create an array of classes, then categories, then static object instances
  auto classList = symtab.beginArray(PtrToInt8Ty);
  classList.addAll(Classes);
  classList.addAll(Categories);
  //  NULL-terminated list of static object instances (mainly constant strings)
  classList.add(statics);
  classList.add(NULLPtr);
  classList.finishAndAddTo(symtab);

  // Construct the symbol table.
  return symtab.finishAndCreateGlobal("", CGM.getPointerAlign());
}();

// The symbol table is contained in a module which has some version-checking
// constants
llvm::Constant *module = [&] {
  llvm::Type *moduleEltTys[] = {
    LongTy, LongTy, PtrToInt8Ty, symtab->getType(), IntTy
  };
  llvm::StructType *moduleTy =
    llvm::StructType::get(CGM.getLLVMContext(),
       makeArrayRef(moduleEltTys).drop_back(unsigned(RuntimeVersion < 10)));

  ConstantInitBuilder builder(CGM);
  auto module = builder.beginStruct(moduleTy);
  // Runtime version, used for ABI compatibility checking.
  module.addInt(LongTy, RuntimeVersion);
  // sizeof(ModuleTy)
  module.addInt(LongTy, CGM.getDataLayout().getTypeStoreSize(moduleTy));

  // The path to the source file where this module was declared
  SourceManager &SM = CGM.getContext().getSourceManager();
  const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
  std::string path =
    (Twine(mainFile->getDir()->getName()) + "/" + mainFile->getName()).str();
  module.add(MakeConstantString(path, ".objc_source_file_name"));
  module.add(symtab);

  if (RuntimeVersion >= 10) {
    switch (CGM.getLangOpts().getGC()) {
    case LangOptions::GCOnly:
      module.addInt(IntTy, 2);
      break;
    case LangOptions::NonGC:
      if (CGM.getLangOpts().ObjCAutoRefCount)
        module.addInt(IntTy, 1);
      else
        module.addInt(IntTy, 0);
      break;
    case LangOptions::HybridGC:
      module.addInt(IntTy, 1);
      break;
    }
  }

  return module.finishAndCreateGlobal("", CGM.getPointerAlign());
}();

// Create the load function calling the runtime entry point with the module
// structure
llvm::Function * LoadFunction = llvm::Function::Create(
    llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
    llvm::GlobalValue::InternalLinkage, ".objc_load_function",
    &TheModule);
llvm::BasicBlock *EntryBB =
    llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
CGBuilderTy Builder(CGM, VMContext);
Builder.SetInsertPoint(EntryBB);

llvm::FunctionType *FT =
  llvm::FunctionType::get(Builder.getVoidTy(), module->getType(), true);
llvm::FunctionCallee Register =
    CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
Builder.CreateCall(Register, module);

if (!ClassAliases.empty()) {
  llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
  llvm::FunctionType *RegisterAliasTy =
    llvm::FunctionType::get(Builder.getVoidTy(),
                            ArgTypes, false);
  llvm::Function *RegisterAlias = llvm::Function::Create(
    RegisterAliasTy,
    llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
    &TheModule);
  llvm::BasicBlock *AliasBB =
    llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
  llvm::BasicBlock *NoAliasBB =
    llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);

  // Branch based on whether the runtime provided class_registerAlias_np()
  llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
          llvm::Constant::getNullValue(RegisterAlias->getType()));
  Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);

  // The true branch (has alias registration function):
  Builder.SetInsertPoint(AliasBB);
  // Emit alias registration calls:
  for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
     iter != ClassAliases.end(); ++iter) {
     llvm::Constant *TheClass =
        TheModule.getGlobalVariable("_OBJC_CLASS_" + iter->first, true);
     if (TheClass) {
       TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
       Builder.CreateCall(RegisterAlias,
                          {TheClass, MakeConstantString(iter->second)});
     }
  }
  // Jump to end:
  Builder.CreateBr(NoAliasBB);

  // Missing alias registration function, just return from the function:
  Builder.SetInsertPoint(NoAliasBB);
}
Builder.CreateRetVoid();

return LoadFunction;
3870}

3872llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
                                        const ObjCContainerDecl *CD) {
CodeGenTypes &Types = CGM.getTypes();
llvm::FunctionType *MethodTy =
  Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD));
std::string FunctionName = getSymbolNameForMethod(OMD);

llvm::Function *Method
  = llvm::Function::Create(MethodTy,
                           llvm::GlobalValue::InternalLinkage,
                           FunctionName,
                           &TheModule);
return Method;
3885}

3887void CGObjCGNU::GenerateDirectMethodPrologue(CodeGenFunction &CGF,
                                           llvm::Function *Fn,
                                           const ObjCMethodDecl *OMD,
                                           const ObjCContainerDecl *CD) {
// GNU runtime doesn't support direct calls at this time
3892}

3894llvm::FunctionCallee CGObjCGNU::GetPropertyGetFunction() {
return GetPropertyFn;
3896}

3898llvm::FunctionCallee CGObjCGNU::GetPropertySetFunction() {
return SetPropertyFn;
3900}

3902llvm::FunctionCallee CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
                                                              bool copy) {
return nullptr;
3905}

3907llvm::FunctionCallee CGObjCGNU::GetGetStructFunction() {
return GetStructPropertyFn;
3909}

3911llvm::FunctionCallee CGObjCGNU::GetSetStructFunction() {
return SetStructPropertyFn;
3913}

3915llvm::FunctionCallee CGObjCGNU::GetCppAtomicObjectGetFunction() {
return nullptr;
3917}

3919llvm::FunctionCallee CGObjCGNU::GetCppAtomicObjectSetFunction() {
return nullptr;
3921}

3923llvm::FunctionCallee CGObjCGNU::EnumerationMutationFunction() {
return EnumerationMutationFn;
3925}

3927void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
                                   const ObjCAtSynchronizedStmt &S) {
EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
3930}


3933void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
                          const ObjCAtTryStmt &S) {
// Unlike the Apple non-fragile runtimes, which also uses
// unwind-based zero cost exceptions, the GNU Objective C runtime's
// EH support isn't a veneer over C++ EH.  Instead, exception
// objects are created by objc_exception_throw and destroyed by
// the personality function; this avoids the need for bracketing
// catch handlers with calls to __blah_begin_catch/__blah_end_catch
// (or even _Unwind_DeleteException), but probably doesn't
// interoperate very well with foreign exceptions.
//
// In Objective-C++ mode, we actually emit something equivalent to the C++
// exception handler.
EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
3947}

3949void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
                            const ObjCAtThrowStmt &S,
                            bool ClearInsertionPoint) {
llvm::Value *ExceptionAsObject;
bool isRethrow = false;

if (const Expr *ThrowExpr = S.getThrowExpr()) {
  llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr);
  ExceptionAsObject = Exception;
} else {
  assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&(static_cast<void> (0))
         "Unexpected rethrow outside @catch block.")(static_cast<void> (0));
  ExceptionAsObject = CGF.ObjCEHValueStack.back();
  isRethrow = true;
}
if (isRethrow && usesSEHExceptions) {
  // For SEH, ExceptionAsObject may be undef, because the catch handler is
  // not passed it for catchalls and so it is not visible to the catch
  // funclet.  The real thrown object will still be live on the stack at this
  // point and will be rethrown.  If we are explicitly rethrowing the object
  // that was passed into the `@catch` block, then this code path is not
  // reached and we will instead call `objc_exception_throw` with an explicit
  // argument.
  llvm::CallBase *Throw = CGF.EmitRuntimeCallOrInvoke(ExceptionReThrowFn);
  Throw->setDoesNotReturn();
}
else {
  ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
  llvm::CallBase *Throw =
      CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
  Throw->setDoesNotReturn();
}
CGF.Builder.CreateUnreachable();
if (ClearInsertionPoint)
  CGF.Builder.ClearInsertionPoint();
3984}

3986llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
                                        Address AddrWeakObj) {
CGBuilderTy &B = CGF.Builder;
AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
return B.CreateCall(WeakReadFn, AddrWeakObj.getPointer());
3991}

3993void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
                                 llvm::Value *src, Address dst) {
CGBuilderTy &B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
B.CreateCall(WeakAssignFn, {src, dst.getPointer()});
3999}

4001void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
                                   llvm::Value *src, Address dst,
                                   bool threadlocal) {
CGBuilderTy &B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
// FIXME. Add threadloca assign API
assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI")(static_cast<void> (0));
B.CreateCall(GlobalAssignFn, {src, dst.getPointer()});
4010}

4012void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
                                 llvm::Value *src, Address dst,
                                 llvm::Value *ivarOffset) {
CGBuilderTy &B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, IdTy);
B.CreateCall(IvarAssignFn, {src, dst.getPointer(), ivarOffset});
4019}

4021void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
                                       llvm::Value *src, Address dst) {
CGBuilderTy &B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
B.CreateCall(StrongCastAssignFn, {src, dst.getPointer()});
4027}

4029void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
                                       Address DestPtr,
                                       Address SrcPtr,
                                       llvm::Value *Size) {
CGBuilderTy &B = CGF.Builder;
DestPtr = EnforceType(B, DestPtr, PtrTy);
SrcPtr = EnforceType(B, SrcPtr, PtrTy);

B.CreateCall(MemMoveFn, {DestPtr.getPointer(), SrcPtr.getPointer(), Size});
4038}

4040llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
                            const ObjCInterfaceDecl *ID,
                            const ObjCIvarDecl *Ivar) {
const std::string Name = GetIVarOffsetVariableName(ID, Ivar);
// Emit the variable and initialize it with what we think the correct value
// is.  This allows code compiled with non-fragile ivars to work correctly
// when linked against code which isn't (most of the time).
llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
if (!IvarOffsetPointer)
  IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
          llvm::Type::getInt32PtrTy(VMContext), false,
          llvm::GlobalValue::ExternalLinkage, nullptr, Name);
return IvarOffsetPointer;
4053}

4055LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
                                     QualType ObjectTy,
                                     llvm::Value *BaseValue,
                                     const ObjCIvarDecl *Ivar,
                                     unsigned CVRQualifiers) {
const ObjCInterfaceDecl *ID =
  ObjectTy->castAs<ObjCObjectType>()->getInterface();
return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
                                EmitIvarOffset(CGF, ID, Ivar));
4064}

4066static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context,
                                                const ObjCInterfaceDecl *OID,
                                                const ObjCIvarDecl *OIVD) {
for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
     next = next->getNextIvar()) {
  if (OIVD == next)
    return OID;
}

// Otherwise check in the super class.
if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
  return FindIvarInterface(Context, Super, OIVD);

return nullptr;
4080}

4082llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
                       const ObjCInterfaceDecl *Interface,
                       const ObjCIvarDecl *Ivar) {
if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
  Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);

  // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
  // and ExternalLinkage, so create a reference to the ivar global and rely on
  // the definition being created as part of GenerateClass.
  if (RuntimeVersion < 10 ||
      CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
    return CGF.Builder.CreateZExtOrBitCast(
        CGF.Builder.CreateAlignedLoad(
            Int32Ty, CGF.Builder.CreateAlignedLoad(
                         llvm::Type::getInt32PtrTy(VMContext),
                         ObjCIvarOffsetVariable(Interface, Ivar),
                         CGF.getPointerAlign(), "ivar"),
            CharUnits::fromQuantity(4)),
        PtrDiffTy);
  std::string name = "__objc_ivar_offset_value_" +
    Interface->getNameAsString() +"." + Ivar->getNameAsString();
  CharUnits Align = CGM.getIntAlign();
  llvm::Value *Offset = TheModule.getGlobalVariable(name);
  if (!Offset) {
    auto GV = new llvm::GlobalVariable(TheModule, IntTy,
        false, llvm::GlobalValue::LinkOnceAnyLinkage,
        llvm::Constant::getNullValue(IntTy), name);
    GV->setAlignment(Align.getAsAlign());
    Offset = GV;
  }
  Offset = CGF.Builder.CreateAlignedLoad(IntTy, Offset, Align);
  if (Offset->getType() != PtrDiffTy)
    Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
  return Offset;
}
uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
4119}

4121CGObjCRuntime *
4122clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) {
auto Runtime = CGM.getLangOpts().ObjCRuntime;
switch (Runtime.getKind()) {
case ObjCRuntime::GNUstep:
  if (Runtime.getVersion() >= VersionTuple(2, 0))
    return new CGObjCGNUstep2(CGM);
  return new CGObjCGNUstep(CGM);

case ObjCRuntime::GCC:
  return new CGObjCGCC(CGM);

case ObjCRuntime::ObjFW:
  return new CGObjCObjFW(CGM);

case ObjCRuntime::FragileMacOSX:
case ObjCRuntime::MacOSX:
case ObjCRuntime::iOS:
case ObjCRuntime::WatchOS:
  llvm_unreachable("these runtimes are not GNU runtimes")__builtin_unreachable();
}
llvm_unreachable("bad runtime")__builtin_unreachable();
4143}

←

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/clang/include/clang/AST/Type.h

1//===- Type.h - C Language Family Type Representation -----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// C Language Family Type Representation
11///
12/// This file defines the clang::Type interface and subclasses, used to
13/// represent types for languages in the C family.
14//
15//===----------------------------------------------------------------------===//

17#ifndef LLVM_CLANG_AST_TYPE_H
18#define LLVM_CLANG_AST_TYPE_H

20#include "clang/AST/DependenceFlags.h"
21#include "clang/AST/NestedNameSpecifier.h"
22#include "clang/AST/TemplateName.h"
23#include "clang/Basic/AddressSpaces.h"
24#include "clang/Basic/AttrKinds.h"
25#include "clang/Basic/Diagnostic.h"
26#include "clang/Basic/ExceptionSpecificationType.h"
27#include "clang/Basic/LLVM.h"
28#include "clang/Basic/Linkage.h"
29#include "clang/Basic/PartialDiagnostic.h"
30#include "clang/Basic/SourceLocation.h"
31#include "clang/Basic/Specifiers.h"
32#include "clang/Basic/Visibility.h"
33#include "llvm/ADT/APInt.h"
34#include "llvm/ADT/APSInt.h"
35#include "llvm/ADT/ArrayRef.h"
36#include "llvm/ADT/FoldingSet.h"
37#include "llvm/ADT/None.h"
38#include "llvm/ADT/Optional.h"
39#include "llvm/ADT/PointerIntPair.h"
40#include "llvm/ADT/PointerUnion.h"
41#include "llvm/ADT/StringRef.h"
42#include "llvm/ADT/Twine.h"
43#include "llvm/ADT/iterator_range.h"
44#include "llvm/Support/Casting.h"
45#include "llvm/Support/Compiler.h"
46#include "llvm/Support/ErrorHandling.h"
47#include "llvm/Support/PointerLikeTypeTraits.h"
48#include "llvm/Support/TrailingObjects.h"
49#include "llvm/Support/type_traits.h"
50#include <cassert>
51#include <cstddef>
52#include <cstdint>
53#include <cstring>
54#include <string>
55#include <type_traits>
56#include <utility>

58namespace clang {

60class ExtQuals;
61class QualType;
62class ConceptDecl;
63class TagDecl;
64class TemplateParameterList;
65class Type;

67enum {
TypeAlignmentInBits = 4,
TypeAlignment = 1 << TypeAlignmentInBits
70};

72namespace serialization {
template <class T> class AbstractTypeReader;
template <class T> class AbstractTypeWriter;
75}

77} // namespace clang

79namespace llvm {

template <typename T>
struct PointerLikeTypeTraits;
template<>
struct PointerLikeTypeTraits< ::clang::Type*> {
  static inline void *getAsVoidPointer(::clang::Type *P) { return P; }

  static inline ::clang::Type *getFromVoidPointer(void *P) {
    return static_cast< ::clang::Type*>(P);
  }

  static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
};

template<>
struct PointerLikeTypeTraits< ::clang::ExtQuals*> {
  static inline void *getAsVoidPointer(::clang::ExtQuals *P) { return P; }

  static inline ::clang::ExtQuals *getFromVoidPointer(void *P) {
    return static_cast< ::clang::ExtQuals*>(P);
  }

  static constexpr int NumLowBitsAvailable = clang::TypeAlignmentInBits;
};

105} // namespace llvm

107namespace clang {

109class ASTContext;
110template <typename> class CanQual;
111class CXXRecordDecl;
112class DeclContext;
113class EnumDecl;
114class Expr;
115class ExtQualsTypeCommonBase;
116class FunctionDecl;
117class IdentifierInfo;
118class NamedDecl;
119class ObjCInterfaceDecl;
120class ObjCProtocolDecl;
121class ObjCTypeParamDecl;
122struct PrintingPolicy;
123class RecordDecl;
124class Stmt;
125class TagDecl;
126class TemplateArgument;
127class TemplateArgumentListInfo;
128class TemplateArgumentLoc;
129class TemplateTypeParmDecl;
130class TypedefNameDecl;
131class UnresolvedUsingTypenameDecl;

133using CanQualType = CanQual<Type>;

135// Provide forward declarations for all of the *Type classes.
136#define TYPE(Class, Base) class Class##Type;
137#include "clang/AST/TypeNodes.inc"

139/// The collection of all-type qualifiers we support.
140/// Clang supports five independent qualifiers:
141/// * C99: const, volatile, and restrict
142/// * MS: __unaligned
143/// * Embedded C (TR18037): address spaces
144/// * Objective C: the GC attributes (none, weak, or strong)
145class Qualifiers {
146public:
enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
  Const    = 0x1,
  Restrict = 0x2,
  Volatile = 0x4,
  CVRMask = Const | Volatile | Restrict
};

enum GC {
  GCNone = 0,
  Weak,
  Strong
};

enum ObjCLifetime {
  /// There is no lifetime qualification on this type.
  OCL_None,

  /// This object can be modified without requiring retains or
  /// releases.
  OCL_ExplicitNone,

  /// Assigning into this object requires the old value to be
  /// released and the new value to be retained.  The timing of the
  /// release of the old value is inexact: it may be moved to
  /// immediately after the last known point where the value is
  /// live.
  OCL_Strong,

  /// Reading or writing from this object requires a barrier call.
  OCL_Weak,

  /// Assigning into this object requires a lifetime extension.
  OCL_Autoreleasing
};

enum {
  /// The maximum supported address space number.
  /// 23 bits should be enough for anyone.
  MaxAddressSpace = 0x7fffffu,

  /// The width of the "fast" qualifier mask.
  FastWidth = 3,

  /// The fast qualifier mask.
  FastMask = (1 << FastWidth) - 1
};

/// Returns the common set of qualifiers while removing them from
/// the given sets.
static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
  // If both are only CVR-qualified, bit operations are sufficient.
  if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
    Qualifiers Q;
    Q.Mask = L.Mask & R.Mask;
    L.Mask &= ~Q.Mask;
    R.Mask &= ~Q.Mask;
    return Q;
  }

  Qualifiers Q;
  unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
  Q.addCVRQualifiers(CommonCRV);
  L.removeCVRQualifiers(CommonCRV);
  R.removeCVRQualifiers(CommonCRV);

  if (L.getObjCGCAttr() == R.getObjCGCAttr()) {
    Q.setObjCGCAttr(L.getObjCGCAttr());
    L.removeObjCGCAttr();
    R.removeObjCGCAttr();
  }

  if (L.getObjCLifetime() == R.getObjCLifetime()) {
    Q.setObjCLifetime(L.getObjCLifetime());
    L.removeObjCLifetime();
    R.removeObjCLifetime();
  }

  if (L.getAddressSpace() == R.getAddressSpace()) {
    Q.setAddressSpace(L.getAddressSpace());
    L.removeAddressSpace();
    R.removeAddressSpace();
  }
  return Q;
}

static Qualifiers fromFastMask(unsigned Mask) {
  Qualifiers Qs;
  Qs.addFastQualifiers(Mask);
  return Qs;
}

static Qualifiers fromCVRMask(unsigned CVR) {
  Qualifiers Qs;
  Qs.addCVRQualifiers(CVR);
  return Qs;
}

static Qualifiers fromCVRUMask(unsigned CVRU) {
  Qualifiers Qs;
  Qs.addCVRUQualifiers(CVRU);
  return Qs;
}

// Deserialize qualifiers from an opaque representation.
static Qualifiers fromOpaqueValue(unsigned opaque) {
  Qualifiers Qs;
  Qs.Mask = opaque;
  return Qs;
}

// Serialize these qualifiers into an opaque representation.
unsigned getAsOpaqueValue() const {
  return Mask;
}

bool hasConst() const { return Mask & Const; }
bool hasOnlyConst() const { return Mask == Const; }
void removeConst() { Mask &= ~Const; }
void addConst() { Mask |= Const; }

bool hasVolatile() const { return Mask & Volatile; }
bool hasOnlyVolatile() const { return Mask == Volatile; }
void removeVolatile() { Mask &= ~Volatile; }
void addVolatile() { Mask |= Volatile; }

bool hasRestrict() const { return Mask & Restrict; }
bool hasOnlyRestrict() const { return Mask == Restrict; }
void removeRestrict() { Mask &= ~Restrict; }
void addRestrict() { Mask |= Restrict; }

bool hasCVRQualifiers() const { return getCVRQualifiers(); }
unsigned getCVRQualifiers() const { return Mask & CVRMask; }
unsigned getCVRUQualifiers() const { return Mask & (CVRMask | UMask); }

void setCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask = (Mask & ~CVRMask) | mask;
}
void removeCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask &= ~mask;
}
void removeCVRQualifiers() {
  removeCVRQualifiers(CVRMask);
}
void addCVRQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits")(static_cast<void> (0));
  Mask |= mask;
}
void addCVRUQualifiers(unsigned mask) {
  assert(!(mask & ~CVRMask & ~UMask) && "bitmask contains non-CVRU bits")(static_cast<void> (0));
  Mask |= mask;
}

bool hasUnaligned() const { return Mask & UMask; }
void setUnaligned(bool flag) {
  Mask = (Mask & ~UMask) | (flag ? UMask : 0);
}
void removeUnaligned() { Mask &= ~UMask; }
void addUnaligned() { Mask |= UMask; }

bool hasObjCGCAttr() const { return Mask & GCAttrMask; }
GC getObjCGCAttr() const { return GC((Mask & GCAttrMask) >> GCAttrShift); }
void setObjCGCAttr(GC type) {
  Mask = (Mask & ~GCAttrMask) | (type << GCAttrShift);
}
void removeObjCGCAttr() { setObjCGCAttr(GCNone); }
void addObjCGCAttr(GC type) {
  assert(type)(static_cast<void> (0));
  setObjCGCAttr(type);
}
Qualifiers withoutObjCGCAttr() const {
  Qualifiers qs = *this;
  qs.removeObjCGCAttr();
  return qs;
}
Qualifiers withoutObjCLifetime() const {
  Qualifiers qs = *this;
  qs.removeObjCLifetime();
  return qs;
}
Qualifiers withoutAddressSpace() const {
  Qualifiers qs = *this;
  qs.removeAddressSpace();
  return qs;
}

bool hasObjCLifetime() const { return Mask & LifetimeMask; }
ObjCLifetime getObjCLifetime() const {
  return ObjCLifetime((Mask & LifetimeMask) >> LifetimeShift);
}
void setObjCLifetime(ObjCLifetime type) {
  Mask = (Mask & ~LifetimeMask) | (type << LifetimeShift);
}
void removeObjCLifetime() { setObjCLifetime(OCL_None); }
void addObjCLifetime(ObjCLifetime type) {
  assert(type)(static_cast<void> (0));
  assert(!hasObjCLifetime())(static_cast<void> (0));
  Mask |= (type << LifetimeShift);
}

/// True if the lifetime is neither None or ExplicitNone.
bool hasNonTrivialObjCLifetime() const {
  ObjCLifetime lifetime = getObjCLifetime();
  return (lifetime > OCL_ExplicitNone);
}

/// True if the lifetime is either strong or weak.
bool hasStrongOrWeakObjCLifetime() const {
  ObjCLifetime lifetime = getObjCLifetime();
  return (lifetime == OCL_Strong || lifetime == OCL_Weak);
}

bool hasAddressSpace() const { return Mask & AddressSpaceMask; }
LangAS getAddressSpace() const {
  return static_cast<LangAS>(Mask >> AddressSpaceShift);
}
bool hasTargetSpecificAddressSpace() const {
  return isTargetAddressSpace(getAddressSpace());
}
/// Get the address space attribute value to be printed by diagnostics.
unsigned getAddressSpaceAttributePrintValue() const {
  auto Addr = getAddressSpace();
  // This function is not supposed to be used with language specific
  // address spaces. If that happens, the diagnostic message should consider
  // printing the QualType instead of the address space value.
  assert(Addr == LangAS::Default || hasTargetSpecificAddressSpace())(static_cast<void> (0));
  if (Addr != LangAS::Default)
    return toTargetAddressSpace(Addr);
  // TODO: The diagnostic messages where Addr may be 0 should be fixed
  // since it cannot differentiate the situation where 0 denotes the default
  // address space or user specified __attribute__((address_space(0))).
  return 0;
}
void setAddressSpace(LangAS space) {
  assert((unsigned)space <= MaxAddressSpace)(static_cast<void> (0));
  Mask = (Mask & ~AddressSpaceMask)
       | (((uint32_t) space) << AddressSpaceShift);
}
void removeAddressSpace() { setAddressSpace(LangAS::Default); }
void addAddressSpace(LangAS space) {
  assert(space != LangAS::Default)(static_cast<void> (0));
  setAddressSpace(space);
}

// Fast qualifiers are those that can be allocated directly
// on a QualType object.
bool hasFastQualifiers() const { return getFastQualifiers(); }
unsigned getFastQualifiers() const { return Mask & FastMask; }
void setFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask = (Mask & ~FastMask) | mask;
}
void removeFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask &= ~mask;
}
void removeFastQualifiers() {
  removeFastQualifiers(FastMask);
}
void addFastQualifiers(unsigned mask) {
  assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits")(static_cast<void> (0));
  Mask |= mask;
}

/// Return true if the set contains any qualifiers which require an ExtQuals
/// node to be allocated.
bool hasNonFastQualifiers() const { return Mask & ~FastMask; }
Qualifiers getNonFastQualifiers() const {
  Qualifiers Quals = *this;
  Quals.setFastQualifiers(0);
  return Quals;
}

/// Return true if the set contains any qualifiers.
bool hasQualifiers() const { return Mask; }
bool empty() const { return !Mask; }

/// Add the qualifiers from the given set to this set.
void addQualifiers(Qualifiers Q) {
  // If the other set doesn't have any non-boolean qualifiers, just
  // bit-or it in.
  if (!(Q.Mask & ~CVRMask))
    Mask |= Q.Mask;
  else {
    Mask |= (Q.Mask & CVRMask);
    if (Q.hasAddressSpace())
      addAddressSpace(Q.getAddressSpace());
    if (Q.hasObjCGCAttr())
      addObjCGCAttr(Q.getObjCGCAttr());
    if (Q.hasObjCLifetime())
      addObjCLifetime(Q.getObjCLifetime());
  }
}

/// Remove the qualifiers from the given set from this set.
void removeQualifiers(Qualifiers Q) {
  // If the other set doesn't have any non-boolean qualifiers, just
  // bit-and the inverse in.
  if (!(Q.Mask & ~CVRMask))
    Mask &= ~Q.Mask;
  else {
    Mask &= ~(Q.Mask & CVRMask);
    if (getObjCGCAttr() == Q.getObjCGCAttr())
      removeObjCGCAttr();
    if (getObjCLifetime() == Q.getObjCLifetime())
      removeObjCLifetime();
    if (getAddressSpace() == Q.getAddressSpace())
      removeAddressSpace();
  }
}

/// Add the qualifiers from the given set to this set, given that
/// they don't conflict.
void addConsistentQualifiers(Qualifiers qs) {
  assert(getAddressSpace() == qs.getAddressSpace() ||(static_cast<void> (0))
         !hasAddressSpace() || !qs.hasAddressSpace())(static_cast<void> (0));
  assert(getObjCGCAttr() == qs.getObjCGCAttr() ||(static_cast<void> (0))
         !hasObjCGCAttr() || !qs.hasObjCGCAttr())(static_cast<void> (0));
  assert(getObjCLifetime() == qs.getObjCLifetime() ||(static_cast<void> (0))
         !hasObjCLifetime() || !qs.hasObjCLifetime())(static_cast<void> (0));
  Mask |= qs.Mask;
}

/// Returns true if address space A is equal to or a superset of B.
/// OpenCL v2.0 defines conversion rules (OpenCLC v2.0 s6.5.5) and notion of
/// overlapping address spaces.
/// CL1.1 or CL1.2:
///   every address space is a superset of itself.
/// CL2.0 adds:
///   __generic is a superset of any address space except for __constant.
static bool isAddressSpaceSupersetOf(LangAS A, LangAS B) {
  // Address spaces must match exactly.
  return A == B ||
         // Otherwise in OpenCLC v2.0 s6.5.5: every address space except
         // for __constant can be used as __generic.
         (A == LangAS::opencl_generic && B != LangAS::opencl_constant) ||
         // We also define global_device and global_host address spaces,
         // to distinguish global pointers allocated on host from pointers
         // allocated on device, which are a subset of __global.
         (A == LangAS::opencl_global && (B == LangAS::opencl_global_device ||
                                         B == LangAS::opencl_global_host)) ||
         (A == LangAS::sycl_global && (B == LangAS::sycl_global_device ||
                                       B == LangAS::sycl_global_host)) ||
         // Consider pointer size address spaces to be equivalent to default.
         ((isPtrSizeAddressSpace(A) || A == LangAS::Default) &&
          (isPtrSizeAddressSpace(B) || B == LangAS::Default)) ||
         // Default is a superset of SYCL address spaces.
         (A == LangAS::Default &&
          (B == LangAS::sycl_private || B == LangAS::sycl_local ||
           B == LangAS::sycl_global || B == LangAS::sycl_global_device ||
           B == LangAS::sycl_global_host)) ||
         // In HIP device compilation, any cuda address space is allowed
         // to implicitly cast into the default address space.
         (A == LangAS::Default &&
          (B == LangAS::cuda_constant || B == LangAS::cuda_device ||
           B == LangAS::cuda_shared));
}

/// Returns true if the address space in these qualifiers is equal to or
/// a superset of the address space in the argument qualifiers.
bool isAddressSpaceSupersetOf(Qualifiers other) const {
  return isAddressSpaceSupersetOf(getAddressSpace(), other.getAddressSpace());
}

/// Determines if these qualifiers compatibly include another set.
/// Generally this answers the question of whether an object with the other
/// qualifiers can be safely used as an object with these qualifiers.
bool compatiblyIncludes(Qualifiers other) const {
  return isAddressSpaceSupersetOf(other) &&
         // ObjC GC qualifiers can match, be added, or be removed, but can't
         // be changed.
         (getObjCGCAttr() == other.getObjCGCAttr() || !hasObjCGCAttr() ||
          !other.hasObjCGCAttr()) &&
         // ObjC lifetime qualifiers must match exactly.
         getObjCLifetime() == other.getObjCLifetime() &&
         // CVR qualifiers may subset.
         (((Mask & CVRMask) | (other.Mask & CVRMask)) == (Mask & CVRMask)) &&
         // U qualifier may superset.
         (!other.hasUnaligned() || hasUnaligned());
}

/// Determines if these qualifiers compatibly include another set of
/// qualifiers from the narrow perspective of Objective-C ARC lifetime.
///
/// One set of Objective-C lifetime qualifiers compatibly includes the other
/// if the lifetime qualifiers match, or if both are non-__weak and the
/// including set also contains the 'const' qualifier, or both are non-__weak
/// and one is None (which can only happen in non-ARC modes).
bool compatiblyIncludesObjCLifetime(Qualifiers other) const {
  if (getObjCLifetime() == other.getObjCLifetime())
    return true;

  if (getObjCLifetime() == OCL_Weak || other.getObjCLifetime() == OCL_Weak)
    return false;

  if (getObjCLifetime() == OCL_None || other.getObjCLifetime() == OCL_None)
    return true;

  return hasConst();
}

/// Determine whether this set of qualifiers is a strict superset of
/// another set of qualifiers, not considering qualifier compatibility.
bool isStrictSupersetOf(Qualifiers Other) const;

bool operator==(Qualifiers Other) const { return Mask == Other.Mask; }
bool operator!=(Qualifiers Other) const { return Mask != Other.Mask; }

explicit operator bool() const { return hasQualifiers(); }

Qualifiers &operator+=(Qualifiers R) {
  addQualifiers(R);
  return *this;
}

// Union two qualifier sets.  If an enumerated qualifier appears
// in both sets, use the one from the right.
friend Qualifiers operator+(Qualifiers L, Qualifiers R) {
  L += R;
  return L;
}

Qualifiers &operator-=(Qualifiers R) {
  removeQualifiers(R);
  return *this;
}

/// Compute the difference between two qualifier sets.
friend Qualifiers operator-(Qualifiers L, Qualifiers R) {
  L -= R;
  return L;
}

std::string getAsString() const;
std::string getAsString(const PrintingPolicy &Policy) const;

static std::string getAddrSpaceAsString(LangAS AS);

bool isEmptyWhenPrinted(const PrintingPolicy &Policy) const;
void print(raw_ostream &OS, const PrintingPolicy &Policy,
           bool appendSpaceIfNonEmpty = false) const;

void Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddInteger(Mask);
}

594private:
// bits:     |0 1 2|3|4 .. 5|6  ..  8|9   ...   31|
//           |C R V|U|GCAttr|Lifetime|AddressSpace|
uint32_t Mask = 0;

static const uint32_t UMask = 0x8;
static const uint32_t UShift = 3;
static const uint32_t GCAttrMask = 0x30;
static const uint32_t GCAttrShift = 4;
static const uint32_t LifetimeMask = 0x1C0;
static const uint32_t LifetimeShift = 6;
static const uint32_t AddressSpaceMask =
    ~(CVRMask | UMask | GCAttrMask | LifetimeMask);
static const uint32_t AddressSpaceShift = 9;
608};

610/// A std::pair-like structure for storing a qualified type split
611/// into its local qualifiers and its locally-unqualified type.
612struct SplitQualType {
/// The locally-unqualified type.
const Type *Ty = nullptr;

/// The local qualifiers.
Qualifiers Quals;

SplitQualType() = default;
SplitQualType(const Type *ty, Qualifiers qs) : Ty(ty), Quals(qs) {}

SplitQualType getSingleStepDesugaredType() const; // end of this file

// Make std::tie work.
std::pair<const Type *,Qualifiers> asPair() const {
  return std::pair<const Type *, Qualifiers>(Ty, Quals);
}

friend bool operator==(SplitQualType a, SplitQualType b) {
  return a.Ty == b.Ty && a.Quals == b.Quals;
}
friend bool operator!=(SplitQualType a, SplitQualType b) {
  return a.Ty != b.Ty || a.Quals != b.Quals;
}
635};

637/// The kind of type we are substituting Objective-C type arguments into.
638///
639/// The kind of substitution affects the replacement of type parameters when
640/// no concrete type information is provided, e.g., when dealing with an
641/// unspecialized type.
642enum class ObjCSubstitutionContext {
/// An ordinary type.
Ordinary,

/// The result type of a method or function.
Result,

/// The parameter type of a method or function.
Parameter,

/// The type of a property.
Property,

/// The superclass of a type.
Superclass,
657};

659/// A (possibly-)qualified type.
660///
661/// For efficiency, we don't store CV-qualified types as nodes on their
662/// own: instead each reference to a type stores the qualifiers.  This
663/// greatly reduces the number of nodes we need to allocate for types (for
664/// example we only need one for 'int', 'const int', 'volatile int',
665/// 'const volatile int', etc).
666///
667/// As an added efficiency bonus, instead of making this a pair, we
668/// just store the two bits we care about in the low bits of the
669/// pointer.  To handle the packing/unpacking, we make QualType be a
670/// simple wrapper class that acts like a smart pointer.  A third bit
671/// indicates whether there are extended qualifiers present, in which
672/// case the pointer points to a special structure.
673class QualType {
friend class QualifierCollector;

// Thankfully, these are efficiently composable.
llvm::PointerIntPair<llvm::PointerUnion<const Type *, const ExtQuals *>,
                     Qualifiers::FastWidth> Value;

const ExtQuals *getExtQualsUnsafe() const {
  return Value.getPointer().get<const ExtQuals*>();
}

const Type *getTypePtrUnsafe() const {
  return Value.getPointer().get<const Type*>();
}

const ExtQualsTypeCommonBase *getCommonPtr() const {
  assert(!isNull() && "Cannot retrieve a NULL type pointer")(static_cast<void> (0));
  auto CommonPtrVal = reinterpret_cast<uintptr_t>(Value.getOpaqueValue());
  CommonPtrVal &= ~(uintptr_t)((1 << TypeAlignmentInBits) - 1);
  return reinterpret_cast<ExtQualsTypeCommonBase*>(CommonPtrVal);
}

695public:
QualType() = default;
QualType(const Type *Ptr, unsigned Quals) : Value(Ptr, Quals) {}
QualType(const ExtQuals *Ptr, unsigned Quals) : Value(Ptr, Quals) {}

unsigned getLocalFastQualifiers() const { return Value.getInt(); }
void setLocalFastQualifiers(unsigned Quals) { Value.setInt(Quals); }

/// Retrieves a pointer to the underlying (unqualified) type.
///
/// This function requires that the type not be NULL. If the type might be
/// NULL, use the (slightly less efficient) \c getTypePtrOrNull().
const Type *getTypePtr() const;

const Type *getTypePtrOrNull() const;

/// Retrieves a pointer to the name of the base type.
const IdentifierInfo *getBaseTypeIdentifier() const;

/// Divides a QualType into its unqualified type and a set of local
/// qualifiers.
SplitQualType split() const;

void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }

static QualType getFromOpaquePtr(const void *Ptr) {
  QualType T;
  T.Value.setFromOpaqueValue(const_cast<void*>(Ptr));
  return T;
}

const Type &operator*() const {
  return *getTypePtr();
}

const Type *operator->() const {
  return getTypePtr();
}

bool isCanonical() const;
bool isCanonicalAsParam() const;

/// Return true if this QualType doesn't point to a type yet.
bool isNull() const {
  return Value.getPointer().isNull();
}

/// Determine whether this particular QualType instance has the
/// "const" qualifier set, without looking through typedefs that may have
/// added "const" at a different level.
bool isLocalConstQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Const);
}

/// Determine whether this type is const-qualified.
bool isConstQualified() const;

/// Determine whether this particular QualType instance has the
/// "restrict" qualifier set, without looking through typedefs that may have
/// added "restrict" at a different level.
bool isLocalRestrictQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Restrict);
}

/// Determine whether this type is restrict-qualified.
bool isRestrictQualified() const;

/// Determine whether this particular QualType instance has the
/// "volatile" qualifier set, without looking through typedefs that may have
/// added "volatile" at a different level.
bool isLocalVolatileQualified() const {
  return (getLocalFastQualifiers() & Qualifiers::Volatile);
}

/// Determine whether this type is volatile-qualified.
bool isVolatileQualified() const;

/// Determine whether this particular QualType instance has any
/// qualifiers, without looking through any typedefs that might add
/// qualifiers at a different level.
bool hasLocalQualifiers() const {
  return getLocalFastQualifiers() || hasLocalNonFastQualifiers();
}

/// Determine whether this type has any qualifiers.
bool hasQualifiers() const;

/// Determine whether this particular QualType instance has any
/// "non-fast" qualifiers, e.g., those that are stored in an ExtQualType
/// instance.
bool hasLocalNonFastQualifiers() const {
  return Value.getPointer().is<const ExtQuals*>();
}

/// Retrieve the set of qualifiers local to this particular QualType
/// instance, not including any qualifiers acquired through typedefs or
/// other sugar.
Qualifiers getLocalQualifiers() const;

/// Retrieve the set of qualifiers applied to this type.
Qualifiers getQualifiers() const;

/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
/// local to this particular QualType instance, not including any qualifiers
/// acquired through typedefs or other sugar.
unsigned getLocalCVRQualifiers() const {
  return getLocalFastQualifiers();
}

/// Retrieve the set of CVR (const-volatile-restrict) qualifiers
/// applied to this type.
unsigned getCVRQualifiers() const;

bool isConstant(const ASTContext& Ctx) const {
  return QualType::isConstant(*this, Ctx);
}

/// Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
bool isPODType(const ASTContext &Context) const;

/// Return true if this is a POD type according to the rules of the C++98
/// standard, regardless of the current compilation's language.
bool isCXX98PODType(const ASTContext &Context) const;

/// Return true if this is a POD type according to the more relaxed rules
/// of the C++11 standard, regardless of the current compilation's language.
/// (C++0x [basic.types]p9). Note that, unlike
/// CXXRecordDecl::isCXX11StandardLayout, this takes DRs into account.
bool isCXX11PODType(const ASTContext &Context) const;

/// Return true if this is a trivial type per (C++0x [basic.types]p9)
bool isTrivialType(const ASTContext &Context) const;

/// Return true if this is a trivially copyable type (C++0x [basic.types]p9)
bool isTriviallyCopyableType(const ASTContext &Context) const;


/// Returns true if it is a class and it might be dynamic.
bool mayBeDynamicClass() const;

/// Returns true if it is not a class or if the class might not be dynamic.
bool mayBeNotDynamicClass() const;

// Don't promise in the API that anything besides 'const' can be
// easily added.

/// Add the `const` type qualifier to this QualType.
void addConst() {
  addFastQualifiers(Qualifiers::Const);
}
QualType withConst() const {
  return withFastQualifiers(Qualifiers::Const);
}

/// Add the `volatile` type qualifier to this QualType.
void addVolatile() {
  addFastQualifiers(Qualifiers::Volatile);
}
QualType withVolatile() const {
  return withFastQualifiers(Qualifiers::Volatile);
}

/// Add the `restrict` qualifier to this QualType.
void addRestrict() {
  addFastQualifiers(Qualifiers::Restrict);
}
QualType withRestrict() const {
  return withFastQualifiers(Qualifiers::Restrict);
}

QualType withCVRQualifiers(unsigned CVR) const {
  return withFastQualifiers(CVR);
}

void addFastQualifiers(unsigned TQs) {
  assert(!(TQs & ~Qualifiers::FastMask)(static_cast<void> (0))
         && "non-fast qualifier bits set in mask!")(static_cast<void> (0));
  Value.setInt(Value.getInt() | TQs);
}

void removeLocalConst();
void removeLocalVolatile();
void removeLocalRestrict();
void removeLocalCVRQualifiers(unsigned Mask);

void removeLocalFastQualifiers() { Value.setInt(0); }
void removeLocalFastQualifiers(unsigned Mask) {
  assert(!(Mask & ~Qualifiers::FastMask) && "mask has non-fast qualifiers")(static_cast<void> (0));
  Value.setInt(Value.getInt() & ~Mask);
}

// Creates a type with the given qualifiers in addition to any
// qualifiers already on this type.
QualType withFastQualifiers(unsigned TQs) const {
  QualType T = *this;
  T.addFastQualifiers(TQs);
  return T;
}

// Creates a type with exactly the given fast qualifiers, removing
// any existing fast qualifiers.
QualType withExactLocalFastQualifiers(unsigned TQs) const {
  return withoutLocalFastQualifiers().withFastQualifiers(TQs);
}

// Removes fast qualifiers, but leaves any extended qualifiers in place.
QualType withoutLocalFastQualifiers() const {
  QualType T = *this;
  T.removeLocalFastQualifiers();
  return T;
}

QualType getCanonicalType() const;

/// Return this type with all of the instance-specific qualifiers
/// removed, but without removing any qualifiers that may have been applied
/// through typedefs.
QualType getLocalUnqualifiedType() const { return QualType(getTypePtr(), 0); }

/// Retrieve the unqualified variant of the given type,
/// removing as little sugar as possible.
///
/// This routine looks through various kinds of sugar to find the
/// least-desugared type that is unqualified. For example, given:
///
/// \code
/// typedef int Integer;
/// typedef const Integer CInteger;
/// typedef CInteger DifferenceType;
/// \endcode
///
/// Executing \c getUnqualifiedType() on the type \c DifferenceType will
/// desugar until we hit the type \c Integer, which has no qualifiers on it.
///
/// The resulting type might still be qualified if it's sugar for an array
/// type.  To strip qualifiers even from within a sugared array type, use
/// ASTContext::getUnqualifiedArrayType.
inline QualType getUnqualifiedType() const;

/// Retrieve the unqualified variant of the given type, removing as little
/// sugar as possible.
///
/// Like getUnqualifiedType(), but also returns the set of
/// qualifiers that were built up.
///
/// The resulting type might still be qualified if it's sugar for an array
/// type.  To strip qualifiers even from within a sugared array type, use
/// ASTContext::getUnqualifiedArrayType.
inline SplitQualType getSplitUnqualifiedType() const;

/// Determine whether this type is more qualified than the other
/// given type, requiring exact equality for non-CVR qualifiers.
bool isMoreQualifiedThan(QualType Other) const;

/// Determine whether this type is at least as qualified as the other
/// given type, requiring exact equality for non-CVR qualifiers.
bool isAtLeastAsQualifiedAs(QualType Other) const;

QualType getNonReferenceType() const;

/// Determine the type of a (typically non-lvalue) expression with the
/// specified result type.
///
/// This routine should be used for expressions for which the return type is
/// explicitly specified (e.g., in a cast or call) and isn't necessarily
/// an lvalue. It removes a top-level reference (since there are no
/// expressions of reference type) and deletes top-level cvr-qualifiers
/// from non-class types (in C++) or all types (in C).
QualType getNonLValueExprType(const ASTContext &Context) const;

/// Remove an outer pack expansion type (if any) from this type. Used as part
/// of converting the type of a declaration to the type of an expression that
/// references that expression. It's meaningless for an expression to have a
/// pack expansion type.
QualType getNonPackExpansionType() const;

/// Return the specified type with any "sugar" removed from
/// the type.  This takes off typedefs, typeof's etc.  If the outer level of
/// the type is already concrete, it returns it unmodified.  This is similar
/// to getting the canonical type, but it doesn't remove *all* typedefs.  For
/// example, it returns "T*" as "T*", (not as "int*"), because the pointer is
/// concrete.
///
/// Qualifiers are left in place.
QualType getDesugaredType(const ASTContext &Context) const {
  return getDesugaredType(*this, Context);
}

SplitQualType getSplitDesugaredType() const {
  return getSplitDesugaredType(*this);
}

/// Return the specified type with one level of "sugar" removed from
/// the type.
///
/// This routine takes off the first typedef, typeof, etc. If the outer level
/// of the type is already concrete, it returns it unmodified.
QualType getSingleStepDesugaredType(const ASTContext &Context) const {
  return getSingleStepDesugaredTypeImpl(*this, Context);
}

/// Returns the specified type after dropping any
/// outer-level parentheses.
QualType IgnoreParens() const {
  if (isa<ParenType>(*this))
    return QualType::IgnoreParens(*this);
  return *this;
}

/// Indicate whether the specified types and qualifiers are identical.
friend bool operator==(const QualType &LHS, const QualType &RHS) {
  return LHS.Value == RHS.Value;
}
friend bool operator!=(const QualType &LHS, const QualType &RHS) {
  return LHS.Value != RHS.Value;
}
friend bool operator<(const QualType &LHS, const QualType &RHS) {
  return LHS.Value < RHS.Value;
}

static std::string getAsString(SplitQualType split,
                               const PrintingPolicy &Policy) {
  return getAsString(split.Ty, split.Quals, Policy);
}
static std::string getAsString(const Type *ty, Qualifiers qs,
                               const PrintingPolicy &Policy);

std::string getAsString() const;
std::string getAsString(const PrintingPolicy &Policy) const;

void print(raw_ostream &OS, const PrintingPolicy &Policy,
           const Twine &PlaceHolder = Twine(),
           unsigned Indentation = 0) const;

static void print(SplitQualType split, raw_ostream &OS,
                  const PrintingPolicy &policy, const Twine &PlaceHolder,
                  unsigned Indentation = 0) {
  return print(split.Ty, split.Quals, OS, policy, PlaceHolder, Indentation);
}

static void print(const Type *ty, Qualifiers qs,
                  raw_ostream &OS, const PrintingPolicy &policy,
                  const Twine &PlaceHolder,
                  unsigned Indentation = 0);

void getAsStringInternal(std::string &Str,
                         const PrintingPolicy &Policy) const;

static void getAsStringInternal(SplitQualType split, std::string &out,
                                const PrintingPolicy &policy) {
  return getAsStringInternal(split.Ty, split.Quals, out, policy);
}

static void getAsStringInternal(const Type *ty, Qualifiers qs,
                                std::string &out,
                                const PrintingPolicy &policy);

class StreamedQualTypeHelper {
  const QualType &T;
  const PrintingPolicy &Policy;
  const Twine &PlaceHolder;
  unsigned Indentation;

public:
  StreamedQualTypeHelper(const QualType &T, const PrintingPolicy &Policy,
                         const Twine &PlaceHolder, unsigned Indentation)
      : T(T), Policy(Policy), PlaceHolder(PlaceHolder),
        Indentation(Indentation) {}

  friend raw_ostream &operator<<(raw_ostream &OS,
                                 const StreamedQualTypeHelper &SQT) {
    SQT.T.print(OS, SQT.Policy, SQT.PlaceHolder, SQT.Indentation);
    return OS;
  }
};

StreamedQualTypeHelper stream(const PrintingPolicy &Policy,
                              const Twine &PlaceHolder = Twine(),
                              unsigned Indentation = 0) const {
  return StreamedQualTypeHelper(*this, Policy, PlaceHolder, Indentation);
}

void dump(const char *s) const;
void dump() const;
void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;

void Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddPointer(getAsOpaquePtr());
}

/// Check if this type has any address space qualifier.
inline bool hasAddressSpace() const;

/// Return the address space of this type.
inline LangAS getAddressSpace() const;

/// Returns true if address space qualifiers overlap with T address space
/// qualifiers.
/// OpenCL C defines conversion rules for pointers to different address spaces
/// and notion of overlapping address spaces.
/// CL1.1 or CL1.2:
///   address spaces overlap iff they are they same.
/// OpenCL C v2.0 s6.5.5 adds:
///   __generic overlaps with any address space except for __constant.
bool isAddressSpaceOverlapping(QualType T) const {
  Qualifiers Q = getQualifiers();
  Qualifiers TQ = T.getQualifiers();
  // Address spaces overlap if at least one of them is a superset of another
  return Q.isAddressSpaceSupersetOf(TQ) || TQ.isAddressSpaceSupersetOf(Q);
}

/// Returns gc attribute of this type.
inline Qualifiers::GC getObjCGCAttr() const;

/// true when Type is objc's weak.
bool isObjCGCWeak() const {
  return getObjCGCAttr() == Qualifiers::Weak;
}

/// true when Type is objc's strong.
bool isObjCGCStrong() const {
  return getObjCGCAttr() == Qualifiers::Strong;
}

/// Returns lifetime attribute of this type.
Qualifiers::ObjCLifetime getObjCLifetime() const {
  return getQualifiers().getObjCLifetime();
}

bool hasNonTrivialObjCLifetime() const {
  return getQualifiers().hasNonTrivialObjCLifetime();
}

bool hasStrongOrWeakObjCLifetime() const {
  return getQualifiers().hasStrongOrWeakObjCLifetime();
}

// true when Type is objc's weak and weak is enabled but ARC isn't.
bool isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const;

enum PrimitiveDefaultInitializeKind {
  /// The type does not fall into any of the following categories. Note that
  /// this case is zero-valued so that values of this enum can be used as a
  /// boolean condition for non-triviality.
  PDIK_Trivial,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __strong qualifier.
  PDIK_ARCStrong,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __weak qualifier.
  PDIK_ARCWeak,

  /// The type is a struct containing a field whose type is not PCK_Trivial.
  PDIK_Struct
};

/// Functions to query basic properties of non-trivial C struct types.

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to default initialize
/// and return the kind.
PrimitiveDefaultInitializeKind
isNonTrivialToPrimitiveDefaultInitialize() const;

enum PrimitiveCopyKind {
  /// The type does not fall into any of the following categories. Note that
  /// this case is zero-valued so that values of this enum can be used as a
  /// boolean condition for non-triviality.
  PCK_Trivial,

  /// The type would be trivial except that it is volatile-qualified. Types
  /// that fall into one of the other non-trivial cases may additionally be
  /// volatile-qualified.
  PCK_VolatileTrivial,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __strong qualifier.
  PCK_ARCStrong,

  /// The type is an Objective-C retainable pointer type that is qualified
  /// with the ARC __weak qualifier.
  PCK_ARCWeak,

  /// The type is a struct containing a field whose type is neither
  /// PCK_Trivial nor PCK_VolatileTrivial.
  /// Note that a C++ struct type does not necessarily match this; C++ copying
  /// semantics are too complex to express here, in part because they depend
  /// on the exact constructor or assignment operator that is chosen by
  /// overload resolution to do the copy.
  PCK_Struct
};

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to copy and return the
/// kind.
PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const;

/// Check if this is a non-trivial type that would cause a C struct
/// transitively containing this type to be non-trivial to destructively
/// move and return the kind. Destructive move in this context is a C++-style
/// move in which the source object is placed in a valid but unspecified state
/// after it is moved, as opposed to a truly destructive move in which the
/// source object is placed in an uninitialized state.
PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const;

enum DestructionKind {
  DK_none,
  DK_cxx_destructor,
  DK_objc_strong_lifetime,
  DK_objc_weak_lifetime,
  DK_nontrivial_c_struct
};

/// Returns a nonzero value if objects of this type require
/// non-trivial work to clean up after.  Non-zero because it's
/// conceivable that qualifiers (objc_gc(weak)?) could make
/// something require destruction.
DestructionKind isDestructedType() const {
  return isDestructedTypeImpl(*this);
}

/// Check if this is or contains a C union that is non-trivial to
/// default-initialize, which is a union that has a member that is non-trivial
/// to default-initialize. If this returns true,
/// isNonTrivialToPrimitiveDefaultInitialize returns PDIK_Struct.
bool hasNonTrivialToPrimitiveDefaultInitializeCUnion() const;

/// Check if this is or contains a C union that is non-trivial to destruct,
/// which is a union that has a member that is non-trivial to destruct. If
/// this returns true, isDestructedType returns DK_nontrivial_c_struct.
bool hasNonTrivialToPrimitiveDestructCUnion() const;

/// Check if this is or contains a C union that is non-trivial to copy, which
/// is a union that has a member that is non-trivial to copy. If this returns
/// true, isNonTrivialToPrimitiveCopy returns PCK_Struct.
bool hasNonTrivialToPrimitiveCopyCUnion() const;

/// Determine whether expressions of the given type are forbidden
/// from being lvalues in C.
///
/// The expression types that are forbidden to be lvalues are:
///   - 'void', but not qualified void
///   - function types
///
/// The exact rule here is C99 6.3.2.1:
///   An lvalue is an expression with an object type or an incomplete
///   type other than void.
bool isCForbiddenLValueType() const;

/// Substitute type arguments for the Objective-C type parameters used in the
/// subject type.
///
/// \param ctx ASTContext in which the type exists.
///
/// \param typeArgs The type arguments that will be substituted for the
/// Objective-C type parameters in the subject type, which are generally
/// computed via \c Type::getObjCSubstitutions. If empty, the type
/// parameters will be replaced with their bounds or id/Class, as appropriate
/// for the context.
///
/// \param context The context in which the subject type was written.
///
/// \returns the resulting type.
QualType substObjCTypeArgs(ASTContext &ctx,
                           ArrayRef<QualType> typeArgs,
                           ObjCSubstitutionContext context) const;

/// Substitute type arguments from an object type for the Objective-C type
/// parameters used in the subject type.
///
/// This operation combines the computation of type arguments for
/// substitution (\c Type::getObjCSubstitutions) with the actual process of
/// substitution (\c QualType::substObjCTypeArgs) for the convenience of
/// callers that need to perform a single substitution in isolation.
///
/// \param objectType The type of the object whose member type we're
/// substituting into. For example, this might be the receiver of a message
/// or the base of a property access.
///
/// \param dc The declaration context from which the subject type was
/// retrieved, which indicates (for example) which type parameters should
/// be substituted.
///
/// \param context The context in which the subject type was written.
///
/// \returns the subject type after replacing all of the Objective-C type
/// parameters with their corresponding arguments.
QualType substObjCMemberType(QualType objectType,
                             const DeclContext *dc,
                             ObjCSubstitutionContext context) const;

/// Strip Objective-C "__kindof" types from the given type.
QualType stripObjCKindOfType(const ASTContext &ctx) const;

/// Remove all qualifiers including _Atomic.
QualType getAtomicUnqualifiedType() const;

1294private:
// These methods are implemented in a separate translation unit;
// "static"-ize them to avoid creating temporary QualTypes in the
// caller.
static bool isConstant(QualType T, const ASTContext& Ctx);
static QualType getDesugaredType(QualType T, const ASTContext &Context);
static SplitQualType getSplitDesugaredType(QualType T);
static SplitQualType getSplitUnqualifiedTypeImpl(QualType type);
static QualType getSingleStepDesugaredTypeImpl(QualType type,
                                               const ASTContext &C);
static QualType IgnoreParens(QualType T);
static DestructionKind isDestructedTypeImpl(QualType type);

/// Check if \param RD is or contains a non-trivial C union.
static bool hasNonTrivialToPrimitiveDefaultInitializeCUnion(const RecordDecl *RD);
static bool hasNonTrivialToPrimitiveDestructCUnion(const RecordDecl *RD);
static bool hasNonTrivialToPrimitiveCopyCUnion(const RecordDecl *RD);
1311};

1313} // namespace clang

1315namespace llvm {

1317/// Implement simplify_type for QualType, so that we can dyn_cast from QualType
1318/// to a specific Type class.
1319template<> struct simplify_type< ::clang::QualType> {
using SimpleType = const ::clang::Type *;

static SimpleType getSimplifiedValue(::clang::QualType Val) {
  return Val.getTypePtr();
}
1325};

1327// Teach SmallPtrSet that QualType is "basically a pointer".
1328template<>
1329struct PointerLikeTypeTraits<clang::QualType> {
static inline void *getAsVoidPointer(clang::QualType P) {
  return P.getAsOpaquePtr();
}

static inline clang::QualType getFromVoidPointer(void *P) {
  return clang::QualType::getFromOpaquePtr(P);
}

// Various qualifiers go in low bits.
static constexpr int NumLowBitsAvailable = 0;
1340};

1342} // namespace llvm

1344namespace clang {

1346/// Base class that is common to both the \c ExtQuals and \c Type
1347/// classes, which allows \c QualType to access the common fields between the
1348/// two.
1349class ExtQualsTypeCommonBase {
friend class ExtQuals;
friend class QualType;
friend class Type;

/// The "base" type of an extended qualifiers type (\c ExtQuals) or
/// a self-referential pointer (for \c Type).
///
/// This pointer allows an efficient mapping from a QualType to its
/// underlying type pointer.
const Type *const BaseType;

/// The canonical type of this type.  A QualType.
QualType CanonicalType;

ExtQualsTypeCommonBase(const Type *baseType, QualType canon)
    : BaseType(baseType), CanonicalType(canon) {}
1366};

1368/// We can encode up to four bits in the low bits of a
1369/// type pointer, but there are many more type qualifiers that we want
1370/// to be able to apply to an arbitrary type.  Therefore we have this
1371/// struct, intended to be heap-allocated and used by QualType to
1372/// store qualifiers.
1373///
1374/// The current design tags the 'const', 'restrict', and 'volatile' qualifiers
1375/// in three low bits on the QualType pointer; a fourth bit records whether
1376/// the pointer is an ExtQuals node. The extended qualifiers (address spaces,
1377/// Objective-C GC attributes) are much more rare.
1378class ExtQuals : public ExtQualsTypeCommonBase, public llvm::FoldingSetNode {
// NOTE: changing the fast qualifiers should be straightforward as
// long as you don't make 'const' non-fast.
// 1. Qualifiers:
//    a) Modify the bitmasks (Qualifiers::TQ and DeclSpec::TQ).
//       Fast qualifiers must occupy the low-order bits.
//    b) Update Qualifiers::FastWidth and FastMask.
// 2. QualType:
//    a) Update is{Volatile,Restrict}Qualified(), defined inline.
//    b) Update remove{Volatile,Restrict}, defined near the end of
//       this header.
// 3. ASTContext:
//    a) Update get{Volatile,Restrict}Type.

/// The immutable set of qualifiers applied by this node. Always contains
/// extended qualifiers.
Qualifiers Quals;

ExtQuals *this_() { return this; }

1398public:
ExtQuals(const Type *baseType, QualType canon, Qualifiers quals)
    : ExtQualsTypeCommonBase(baseType,
                             canon.isNull() ? QualType(this_(), 0) : canon),
      Quals(quals) {
  assert(Quals.hasNonFastQualifiers()(static_cast<void> (0))
         && "ExtQuals created with no fast qualifiers")(static_cast<void> (0));
  assert(!Quals.hasFastQualifiers()(static_cast<void> (0))
         && "ExtQuals created with fast qualifiers")(static_cast<void> (0));
}

Qualifiers getQualifiers() const { return Quals; }

bool hasObjCGCAttr() const { return Quals.hasObjCGCAttr(); }
Qualifiers::GC getObjCGCAttr() const { return Quals.getObjCGCAttr(); }

bool hasObjCLifetime() const { return Quals.hasObjCLifetime(); }
Qualifiers::ObjCLifetime getObjCLifetime() const {
  return Quals.getObjCLifetime();
}

bool hasAddressSpace() const { return Quals.hasAddressSpace(); }
LangAS getAddressSpace() const { return Quals.getAddressSpace(); }

const Type *getBaseType() const { return BaseType; }

1424public:
void Profile(llvm::FoldingSetNodeID &ID) const {
  Profile(ID, getBaseType(), Quals);
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const Type *BaseType,
                    Qualifiers Quals) {
  assert(!Quals.hasFastQualifiers() && "fast qualifiers in ExtQuals hash!")(static_cast<void> (0));
  ID.AddPointer(BaseType);
  Quals.Profile(ID);
}
1436};

1438/// The kind of C++11 ref-qualifier associated with a function type.
1439/// This determines whether a member function's "this" object can be an
1440/// lvalue, rvalue, or neither.
1441enum RefQualifierKind {
/// No ref-qualifier was provided.
RQ_None = 0,

/// An lvalue ref-qualifier was provided (\c &).
RQ_LValue,

/// An rvalue ref-qualifier was provided (\c &&).
RQ_RValue
1450};

1452/// Which keyword(s) were used to create an AutoType.
1453enum class AutoTypeKeyword {
/// auto
Auto,

/// decltype(auto)
DecltypeAuto,

/// __auto_type (GNU extension)
GNUAutoType
1462};

1464/// The base class of the type hierarchy.
1465///
1466/// A central concept with types is that each type always has a canonical
1467/// type.  A canonical type is the type with any typedef names stripped out
1468/// of it or the types it references.  For example, consider:
1469///
1470///  typedef int  foo;
1471///  typedef foo* bar;
1472///    'int *'    'foo *'    'bar'
1473///
1474/// There will be a Type object created for 'int'.  Since int is canonical, its
1475/// CanonicalType pointer points to itself.  There is also a Type for 'foo' (a
1476/// TypedefType).  Its CanonicalType pointer points to the 'int' Type.  Next
1477/// there is a PointerType that represents 'int*', which, like 'int', is
1478/// canonical.  Finally, there is a PointerType type for 'foo*' whose canonical
1479/// type is 'int*', and there is a TypedefType for 'bar', whose canonical type
1480/// is also 'int*'.
1481///
1482/// Non-canonical types are useful for emitting diagnostics, without losing
1483/// information about typedefs being used.  Canonical types are useful for type
1484/// comparisons (they allow by-pointer equality tests) and useful for reasoning
1485/// about whether something has a particular form (e.g. is a function type),
1486/// because they implicitly, recursively, strip all typedefs out of a type.
1487///
1488/// Types, once created, are immutable.
1489///
1490class alignas(8) Type : public ExtQualsTypeCommonBase {
1491public:
enum TypeClass {
1493#define TYPE(Class, Base) Class,
1494#define LAST_TYPE(Class) TypeLast = Class
1495#define ABSTRACT_TYPE(Class, Base)
1496#include "clang/AST/TypeNodes.inc"
};

1499private:
/// Bitfields required by the Type class.
class TypeBitfields {
  friend class Type;
  template <class T> friend class TypePropertyCache;

  /// TypeClass bitfield - Enum that specifies what subclass this belongs to.
  unsigned TC : 8;

  /// Store information on the type dependency.
  unsigned Dependence : llvm::BitWidth<TypeDependence>;

  /// True if the cache (i.e. the bitfields here starting with
  /// 'Cache') is valid.
  mutable unsigned CacheValid : 1;

  /// Linkage of this type.
  mutable unsigned CachedLinkage : 3;

  /// Whether this type involves and local or unnamed types.
  mutable unsigned CachedLocalOrUnnamed : 1;

  /// Whether this type comes from an AST file.
  mutable unsigned FromAST : 1;

  bool isCacheValid() const {
    return CacheValid;
  }

  Linkage getLinkage() const {
    assert(isCacheValid() && "getting linkage from invalid cache")(static_cast<void> (0));
    return static_cast<Linkage>(CachedLinkage);
  }

  bool hasLocalOrUnnamedType() const {
    assert(isCacheValid() && "getting linkage from invalid cache")(static_cast<void> (0));
    return CachedLocalOrUnnamed;
  }
};
enum { NumTypeBits = 8 + llvm::BitWidth<TypeDependence> + 6 };

1540protected:
// These classes allow subclasses to somewhat cleanly pack bitfields
// into Type.

class ArrayTypeBitfields {
  friend class ArrayType;

  unsigned : NumTypeBits;

  /// CVR qualifiers from declarations like
  /// 'int X[static restrict 4]'. For function parameters only.
  unsigned IndexTypeQuals : 3;

  /// Storage class qualifiers from declarations like
  /// 'int X[static restrict 4]'. For function parameters only.
  /// Actually an ArrayType::ArraySizeModifier.
  unsigned SizeModifier : 3;
};

class ConstantArrayTypeBitfields {
  friend class ConstantArrayType;

  unsigned : NumTypeBits + 3 + 3;

  /// Whether we have a stored size expression.
  unsigned HasStoredSizeExpr : 1;
};

class BuiltinTypeBitfields {
  friend class BuiltinType;

  unsigned : NumTypeBits;

  /// The kind (BuiltinType::Kind) of builtin type this is.
  unsigned Kind : 8;
};

/// FunctionTypeBitfields store various bits belonging to FunctionProtoType.
/// Only common bits are stored here. Additional uncommon bits are stored
/// in a trailing object after FunctionProtoType.
class FunctionTypeBitfields {
  friend class FunctionProtoType;
  friend class FunctionType;

  unsigned : NumTypeBits;

  /// Extra information which affects how the function is called, like
  /// regparm and the calling convention.
  unsigned ExtInfo : 13;

  /// The ref-qualifier associated with a \c FunctionProtoType.
  ///
  /// This is a value of type \c RefQualifierKind.
  unsigned RefQualifier : 2;

  /// Used only by FunctionProtoType, put here to pack with the
  /// other bitfields.
  /// The qualifiers are part of FunctionProtoType because...
  ///
  /// C++ 8.3.5p4: The return type, the parameter type list and the
  /// cv-qualifier-seq, [...], are part of the function type.
  unsigned FastTypeQuals : Qualifiers::FastWidth;
  /// Whether this function has extended Qualifiers.
  unsigned HasExtQuals : 1;

  /// The number of parameters this function has, not counting '...'.
  /// According to [implimits] 8 bits should be enough here but this is
  /// somewhat easy to exceed with metaprogramming and so we would like to
  /// keep NumParams as wide as reasonably possible.
  unsigned NumParams : 16;

  /// The type of exception specification this function has.
  unsigned ExceptionSpecType : 4;

  /// Whether this function has extended parameter information.
  unsigned HasExtParameterInfos : 1;

  /// Whether the function is variadic.
  unsigned Variadic : 1;

  /// Whether this function has a trailing return type.
  unsigned HasTrailingReturn : 1;
};

class ObjCObjectTypeBitfields {
  friend class ObjCObjectType;

  unsigned : NumTypeBits;

  /// The number of type arguments stored directly on this object type.
  unsigned NumTypeArgs : 7;

  /// The number of protocols stored directly on this object type.
  unsigned NumProtocols : 6;

  /// Whether this is a "kindof" type.
  unsigned IsKindOf : 1;
};

class ReferenceTypeBitfields {
  friend class ReferenceType;

  unsigned : NumTypeBits;

  /// True if the type was originally spelled with an lvalue sigil.
  /// This is never true of rvalue references but can also be false
  /// on lvalue references because of C++0x [dcl.typedef]p9,
  /// as follows:
  ///
  ///   typedef int &ref;    // lvalue, spelled lvalue
  ///   typedef int &&rvref; // rvalue
  ///   ref &a;              // lvalue, inner ref, spelled lvalue
  ///   ref &&a;             // lvalue, inner ref
  ///   rvref &a;            // lvalue, inner ref, spelled lvalue
  ///   rvref &&a;           // rvalue, inner ref
  unsigned SpelledAsLValue : 1;

  /// True if the inner type is a reference type.  This only happens
  /// in non-canonical forms.
  unsigned InnerRef : 1;
};

class TypeWithKeywordBitfields {
  friend class TypeWithKeyword;

  unsigned : NumTypeBits;

  /// An ElaboratedTypeKeyword.  8 bits for efficient access.
  unsigned Keyword : 8;
};

enum { NumTypeWithKeywordBits = 8 };

class ElaboratedTypeBitfields {
  friend class ElaboratedType;

  unsigned : NumTypeBits;
  unsigned : NumTypeWithKeywordBits;

  /// Whether the ElaboratedType has a trailing OwnedTagDecl.
  unsigned HasOwnedTagDecl : 1;
};

class VectorTypeBitfields {
  friend class VectorType;
  friend class DependentVectorType;

  unsigned : NumTypeBits;

  /// The kind of vector, either a generic vector type or some
  /// target-specific vector type such as for AltiVec or Neon.
  unsigned VecKind : 3;
  /// The number of elements in the vector.
  uint32_t NumElements;
};

class AttributedTypeBitfields {
  friend class AttributedType;

  unsigned : NumTypeBits;

  /// An AttributedType::Kind
  unsigned AttrKind : 32 - NumTypeBits;
};

class AutoTypeBitfields {
  friend class AutoType;

  unsigned : NumTypeBits;

  /// Was this placeholder type spelled as 'auto', 'decltype(auto)',
  /// or '__auto_type'?  AutoTypeKeyword value.
  unsigned Keyword : 2;

  /// The number of template arguments in the type-constraints, which is
  /// expected to be able to hold at least 1024 according to [implimits].
  /// However as this limit is somewhat easy to hit with template
  /// metaprogramming we'd prefer to keep it as large as possible.
  /// At the moment it has been left as a non-bitfield since this type
  /// safely fits in 64 bits as an unsigned, so there is no reason to
  /// introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class SubstTemplateTypeParmPackTypeBitfields {
  friend class SubstTemplateTypeParmPackType;

  unsigned : NumTypeBits;

  /// The number of template arguments in \c Arguments, which is
  /// expected to be able to hold at least 1024 according to [implimits].
  /// However as this limit is somewhat easy to hit with template
  /// metaprogramming we'd prefer to keep it as large as possible.
  /// At the moment it has been left as a non-bitfield since this type
  /// safely fits in 64 bits as an unsigned, so there is no reason to
  /// introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class TemplateSpecializationTypeBitfields {
  friend class TemplateSpecializationType;

  unsigned : NumTypeBits;

  /// Whether this template specialization type is a substituted type alias.
  unsigned TypeAlias : 1;

  /// The number of template arguments named in this class template
  /// specialization, which is expected to be able to hold at least 1024
  /// according to [implimits]. However, as this limit is somewhat easy to
  /// hit with template metaprogramming we'd prefer to keep it as large
  /// as possible. At the moment it has been left as a non-bitfield since
  /// this type safely fits in 64 bits as an unsigned, so there is no reason
  /// to introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class DependentTemplateSpecializationTypeBitfields {
  friend class DependentTemplateSpecializationType;

  unsigned : NumTypeBits;
  unsigned : NumTypeWithKeywordBits;

  /// The number of template arguments named in this class template
  /// specialization, which is expected to be able to hold at least 1024
  /// according to [implimits]. However, as this limit is somewhat easy to
  /// hit with template metaprogramming we'd prefer to keep it as large
  /// as possible. At the moment it has been left as a non-bitfield since
  /// this type safely fits in 64 bits as an unsigned, so there is no reason
  /// to introduce the performance impact of a bitfield.
  unsigned NumArgs;
};

class PackExpansionTypeBitfields {
  friend class PackExpansionType;

  unsigned : NumTypeBits;

  /// The number of expansions that this pack expansion will
  /// generate when substituted (+1), which is expected to be able to
  /// hold at least 1024 according to [implimits]. However, as this limit
  /// is somewhat easy to hit with template metaprogramming we'd prefer to
  /// keep it as large as possible. At the moment it has been left as a
  /// non-bitfield since this type safely fits in 64 bits as an unsigned, so
  /// there is no reason to introduce the performance impact of a bitfield.
  ///
  /// This field will only have a non-zero value when some of the parameter
  /// packs that occur within the pattern have been substituted but others
  /// have not.
  unsigned NumExpansions;
};

union {
  TypeBitfields TypeBits;
  ArrayTypeBitfields ArrayTypeBits;
  ConstantArrayTypeBitfields ConstantArrayTypeBits;
  AttributedTypeBitfields AttributedTypeBits;
  AutoTypeBitfields AutoTypeBits;
  BuiltinTypeBitfields BuiltinTypeBits;
  FunctionTypeBitfields FunctionTypeBits;
  ObjCObjectTypeBitfields ObjCObjectTypeBits;
  ReferenceTypeBitfields ReferenceTypeBits;
  TypeWithKeywordBitfields TypeWithKeywordBits;
  ElaboratedTypeBitfields ElaboratedTypeBits;
  VectorTypeBitfields VectorTypeBits;
  SubstTemplateTypeParmPackTypeBitfields SubstTemplateTypeParmPackTypeBits;
  TemplateSpecializationTypeBitfields TemplateSpecializationTypeBits;
  DependentTemplateSpecializationTypeBitfields
    DependentTemplateSpecializationTypeBits;
  PackExpansionTypeBitfields PackExpansionTypeBits;
};

1812private:
template <class T> friend class TypePropertyCache;

/// Set whether this type comes from an AST file.
void setFromAST(bool V = true) const {
  TypeBits.FromAST = V;
}

1820protected:
friend class ASTContext;

Type(TypeClass tc, QualType canon, TypeDependence Dependence)
    : ExtQualsTypeCommonBase(this,
                             canon.isNull() ? QualType(this_(), 0) : canon) {
  static_assert(sizeof(*this) <= 8 + sizeof(ExtQualsTypeCommonBase),
                "changing bitfields changed sizeof(Type)!");
  static_assert(alignof(decltype(*this)) % sizeof(void *) == 0,
                "Insufficient alignment!");
  TypeBits.TC = tc;
  TypeBits.Dependence = static_cast<unsigned>(Dependence);
  TypeBits.CacheValid = false;
  TypeBits.CachedLocalOrUnnamed = false;
  TypeBits.CachedLinkage = NoLinkage;
  TypeBits.FromAST = false;
}

// silence VC++ warning C4355: 'this' : used in base member initializer list
Type *this_() { return this; }

void setDependence(TypeDependence D) {
  TypeBits.Dependence = static_cast<unsigned>(D);
}

void addDependence(TypeDependence D) { setDependence(getDependence() | D); }

1847public:
friend class ASTReader;
friend class ASTWriter;
template <class T> friend class serialization::AbstractTypeReader;
template <class T> friend class serialization::AbstractTypeWriter;

Type(const Type &) = delete;
Type(Type &&) = delete;
Type &operator=(const Type &) = delete;
Type &operator=(Type &&) = delete;

TypeClass getTypeClass() const { return static_cast<TypeClass>(TypeBits.TC); }

/// Whether this type comes from an AST file.
bool isFromAST() const { return TypeBits.FromAST; }

/// Whether this type is or contains an unexpanded parameter
/// pack, used to support C++0x variadic templates.
///
/// A type that contains a parameter pack shall be expanded by the
/// ellipsis operator at some point. For example, the typedef in the
/// following example contains an unexpanded parameter pack 'T':
///
/// \code
/// template<typename ...T>
/// struct X {
///   typedef T* pointer_types; // ill-formed; T is a parameter pack.
/// };
/// \endcode
///
/// Note that this routine does not specify which
bool containsUnexpandedParameterPack() const {
  return getDependence() & TypeDependence::UnexpandedPack;
}

/// Determines if this type would be canonical if it had no further
/// qualification.
bool isCanonicalUnqualified() const {
  return CanonicalType == QualType(this, 0);
}

/// Pull a single level of sugar off of this locally-unqualified type.
/// Users should generally prefer SplitQualType::getSingleStepDesugaredType()
/// or QualType::getSingleStepDesugaredType(const ASTContext&).
QualType getLocallyUnqualifiedSingleStepDesugaredType() const;

/// As an extension, we classify types as one of "sized" or "sizeless";
/// every type is one or the other.  Standard types are all sized;
/// sizeless types are purely an extension.
///
/// Sizeless types contain data with no specified size, alignment,
/// or layout.
bool isSizelessType() const;
bool isSizelessBuiltinType() const;

/// Determines if this is a sizeless type supported by the
/// 'arm_sve_vector_bits' type attribute, which can be applied to a single
/// SVE vector or predicate, excluding tuple types such as svint32x4_t.
bool isVLSTBuiltinType() const;

/// Returns the representative type for the element of an SVE builtin type.
/// This is used to represent fixed-length SVE vectors created with the
/// 'arm_sve_vector_bits' type attribute as VectorType.
QualType getSveEltType(const ASTContext &Ctx) const;

/// Types are partitioned into 3 broad categories (C99 6.2.5p1):
/// object types, function types, and incomplete types.

/// Return true if this is an incomplete type.
/// A type that can describe objects, but which lacks information needed to
/// determine its size (e.g. void, or a fwd declared struct). Clients of this
/// routine will need to determine if the size is actually required.
///
/// Def If non-null, and the type refers to some kind of declaration
/// that can be completed (such as a C struct, C++ class, or Objective-C
/// class), will be set to the declaration.
bool isIncompleteType(NamedDecl **Def = nullptr) const;

/// Return true if this is an incomplete or object
/// type, in other words, not a function type.
bool isIncompleteOrObjectType() const {
  return !isFunctionType();
}

/// Determine whether this type is an object type.
bool isObjectType() const {
  // C++ [basic.types]p8:
  //   An object type is a (possibly cv-qualified) type that is not a
  //   function type, not a reference type, and not a void type.
  return !isReferenceType() && !isFunctionType() && !isVoidType();
}

/// Return true if this is a literal type
/// (C++11 [basic.types]p10)
bool isLiteralType(const ASTContext &Ctx) const;

/// Determine if this type is a structural type, per C++20 [temp.param]p7.
bool isStructuralType() const;

/// Test if this type is a standard-layout type.
/// (C++0x [basic.type]p9)
bool isStandardLayoutType() const;

/// Helper methods to distinguish type categories. All type predicates
/// operate on the canonical type, ignoring typedefs and qualifiers.

/// Returns true if the type is a builtin type.
bool isBuiltinType() const;

/// Test for a particular builtin type.
bool isSpecificBuiltinType(unsigned K) const;

/// Test for a type which does not represent an actual type-system type but
/// is instead used as a placeholder for various convenient purposes within
/// Clang.  All such types are BuiltinTypes.
bool isPlaceholderType() const;
const BuiltinType *getAsPlaceholderType() const;

/// Test for a specific placeholder type.
bool isSpecificPlaceholderType(unsigned K) const;

/// Test for a placeholder type other than Overload; see
/// BuiltinType::isNonOverloadPlaceholderType.
bool isNonOverloadPlaceholderType() const;

/// isIntegerType() does *not* include complex integers (a GCC extension).
/// isComplexIntegerType() can be used to test for complex integers.
bool isIntegerType() const;     // C99 6.2.5p17 (int, char, bool, enum)
bool isEnumeralType() const;

/// Determine whether this type is a scoped enumeration type.
bool isScopedEnumeralType() const;
bool isBooleanType() const;
bool isCharType() const;
bool isWideCharType() const;
bool isChar8Type() const;
bool isChar16Type() const;
bool isChar32Type() const;
bool isAnyCharacterType() const;
bool isIntegralType(const ASTContext &Ctx) const;

/// Determine whether this type is an integral or enumeration type.
bool isIntegralOrEnumerationType() const;

/// Determine whether this type is an integral or unscoped enumeration type.
bool isIntegralOrUnscopedEnumerationType() const;
bool isUnscopedEnumerationType() const;

/// Floating point categories.
bool isRealFloatingType() const; // C99 6.2.5p10 (float, double, long double)
/// isComplexType() does *not* include complex integers (a GCC extension).
/// isComplexIntegerType() can be used to test for complex integers.
bool isComplexType() const;      // C99 6.2.5p11 (complex)
bool isAnyComplexType() const;   // C99 6.2.5p11 (complex) + Complex Int.
bool isFloatingType() const;     // C99 6.2.5p11 (real floating + complex)
bool isHalfType() const;         // OpenCL 6.1.1.1, NEON (IEEE 754-2008 half)
bool isFloat16Type() const;      // C11 extension ISO/IEC TS 18661
bool isBFloat16Type() const;
bool isFloat128Type() const;
bool isRealType() const;         // C99 6.2.5p17 (real floating + integer)
bool isArithmeticType() const;   // C99 6.2.5p18 (integer + floating)
bool isVoidType() const;         // C99 6.2.5p19
bool isScalarType() const;       // C99 6.2.5p21 (arithmetic + pointers)
bool isAggregateType() const;
bool isFundamentalType() const;
bool isCompoundType() const;

// Type Predicates: Check to see if this type is structurally the specified
// type, ignoring typedefs and qualifiers.
bool isFunctionType() const;
bool isFunctionNoProtoType() const { return getAs<FunctionNoProtoType>(); }
bool isFunctionProtoType() const { return getAs<FunctionProtoType>(); }
bool isPointerType() const;
bool isAnyPointerType() const;   // Any C pointer or ObjC object pointer
bool isBlockPointerType() const;
bool isVoidPointerType() const;
bool isReferenceType() const;
bool isLValueReferenceType() const;
bool isRValueReferenceType() const;
bool isObjectPointerType() const;
bool isFunctionPointerType() const;
bool isFunctionReferenceType() const;
bool isMemberPointerType() const;
bool isMemberFunctionPointerType() const;
bool isMemberDataPointerType() const;
bool isArrayType() const;
bool isConstantArrayType() const;
bool isIncompleteArrayType() const;
bool isVariableArrayType() const;
bool isDependentSizedArrayType() const;
bool isRecordType() const;
bool isClassType() const;
bool isStructureType() const;
bool isObjCBoxableRecordType() const;
bool isInterfaceType() const;
bool isStructureOrClassType() const;
bool isUnionType() const;
bool isComplexIntegerType() const;            // GCC _Complex integer type.
bool isVectorType() const;                    // GCC vector type.
bool isExtVectorType() const;                 // Extended vector type.
bool isMatrixType() const;                    // Matrix type.
bool isConstantMatrixType() const;            // Constant matrix type.
bool isDependentAddressSpaceType() const;     // value-dependent address space qualifier
bool isObjCObjectPointerType() const;         // pointer to ObjC object
bool isObjCRetainableType() const;            // ObjC object or block pointer
bool isObjCLifetimeType() const;              // (array of)* retainable type
bool isObjCIndirectLifetimeType() const;      // (pointer to)* lifetime type
bool isObjCNSObjectType() const;              // __attribute__((NSObject))
bool isObjCIndependentClassType() const;      // __attribute__((objc_independent_class))
// 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 isDecltypeType() 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.
bool isObjCIdOrObjectKindOfType(const ASTContext &ctx,
                                const ObjCObjectType *&bound) const;

bool isObjCClassType() const;                 // Class

/// Whether the type is Objective-C 'Class' or a __kindof type of an
/// Class type, e.g., __kindof Class <NSCopying>.
///
/// Unlike \c isObjCIdOrObjectKindOfType, there is no relevant bound
/// here because Objective-C's type system cannot express "a class
/// object for a subclass of NSFoo".
bool isObjCClassOrClassKindOfType() const;

bool isBlockCompatibleObjCPointerType(ASTContext &ctx) const;
bool isObjCSelType() const;                 // Class
bool isObjCBuiltinType() const;               // 'id' or 'Class'
bool isObjCARCBridgableType() const;
bool isCARCBridgableType() const;
bool isTemplateTypeParmType() const;          // C++ template type parameter
bool isNullPtrType() const;                   // C++11 std::nullptr_t
bool isNothrowT() const;                      // C++   std::nothrow_t
bool isAlignValT() const;                     // C++17 std::align_val_t
bool isStdByteType() const;                   // C++17 std::byte
bool isAtomicType() const;                    // C11 _Atomic()
bool isUndeducedAutoType() const;             // C++11 auto or
                                              // C++14 decltype(auto)
bool isTypedefNameType() const;               // typedef or alias template

2110#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
bool is##Id##Type() const;
2112#include "clang/Basic/OpenCLImageTypes.def"

bool isImageType() const;                     // Any OpenCL image type

bool isSamplerT() const;                      // OpenCL sampler_t
bool isEventT() const;                        // OpenCL event_t
bool isClkEventT() const;                     // OpenCL clk_event_t
bool isQueueT() const;                        // OpenCL queue_t
bool isReserveIDT() const;                    // OpenCL reserve_id_t

2122#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
bool is##Id##Type() const;
2124#include "clang/Basic/OpenCLExtensionTypes.def"
// Type defined in cl_intel_device_side_avc_motion_estimation OpenCL extension
bool isOCLIntelSubgroupAVCType() const;
bool isOCLExtOpaqueType() const;              // Any OpenCL extension type

bool isPipeType() const;                      // OpenCL pipe type
bool isExtIntType() const;                    // Extended Int Type
bool isOpenCLSpecificType() const;            // Any OpenCL specific type

/// Determines if this type, which must satisfy
/// isObjCLifetimeType(), is implicitly __unsafe_unretained rather
/// than implicitly __strong.
bool isObjCARCImplicitlyUnretainedType() const;

/// Check if the type is the CUDA device builtin surface type.
bool isCUDADeviceBuiltinSurfaceType() const;
/// Check if the type is the CUDA device builtin texture type.
bool isCUDADeviceBuiltinTextureType() const;

/// Return the implicit lifetime for this type, which must not be dependent.
Qualifiers::ObjCLifetime getObjCARCImplicitLifetime() const;

enum ScalarTypeKind {
  STK_CPointer,
  STK_BlockPointer,
  STK_ObjCObjectPointer,
  STK_MemberPointer,
  STK_Bool,
  STK_Integral,
  STK_Floating,
  STK_IntegralComplex,
  STK_FloatingComplex,
  STK_FixedPoint
};

/// Given that this is a scalar type, classify it.
ScalarTypeKind getScalarTypeKind() const;

TypeDependence getDependence() const {
  return static_cast<TypeDependence>(TypeBits.Dependence);
}

/// Whether this type is an error type.
bool containsErrors() const {
  return getDependence() & TypeDependence::Error;
}

/// Whether this type is a dependent type, meaning that its definition
/// somehow depends on a template parameter (C++ [temp.dep.type]).
bool isDependentType() const {
  return getDependence() & TypeDependence::Dependent;
}

/// Determine whether this type is an instantiation-dependent type,
/// meaning that the type involves a template parameter (even if the
/// definition does not actually depend on the type substituted for that
/// template parameter).
bool isInstantiationDependentType() const {
  return getDependence() & TypeDependence::Instantiation;
}

/// Determine whether this type is an undeduced type, meaning that
/// it somehow involves a C++11 'auto' type or similar which has not yet been
/// deduced.
bool isUndeducedType() const;

/// Whether this type is a variably-modified type (C99 6.7.5).
bool isVariablyModifiedType() const {
  return getDependence() & TypeDependence::VariablyModified;
}

/// Whether this type involves a variable-length array type
/// with a definite size.
bool hasSizedVLAType() const;

/// Whether this type is or contains a local or unnamed type.
bool hasUnnamedOrLocalType() const;

bool isOverloadableType() const;

/// Determine wither this type is a C++ elaborated-type-specifier.
bool isElaboratedTypeSpecifier() const;

bool canDecayToPointerType() const;

/// Whether this type is represented natively as a pointer.  This includes
/// pointers, references, block pointers, and Objective-C interface,
/// qualified id, and qualified interface types, as well as nullptr_t.
bool hasPointerRepresentation() const;

/// Whether this type can represent an objective pointer type for the
/// purpose of GC'ability
bool hasObjCPointerRepresentation() const;

/// Determine whether this type has an integer representation
/// of some sort, e.g., it is an integer type or a vector.
bool hasIntegerRepresentation() const;

/// Determine whether this type has an signed integer representation
/// of some sort, e.g., it is an signed integer type or a vector.
bool hasSignedIntegerRepresentation() const;

/// Determine whether this type has an unsigned integer representation
/// of some sort, e.g., it is an unsigned integer type or a vector.
bool hasUnsignedIntegerRepresentation() const;

/// Determine whether this type has a floating-point representation
/// of some sort, e.g., it is a floating-point type or a vector thereof.
bool hasFloatingRepresentation() const;

// Type Checking Functions: Check to see if this type is structurally the
// specified type, ignoring typedefs and qualifiers, and return a pointer to
// the best type we can.
const RecordType *getAsStructureType() const;
/// NOTE: getAs*ArrayType are methods on ASTContext.
const RecordType *getAsUnionType() const;
const ComplexType *getAsComplexIntegerType() const; // GCC complex int type.
const ObjCObjectType *getAsObjCInterfaceType() const;

// The following is a convenience method that returns an ObjCObjectPointerType
// for object declared using an interface.
const ObjCObjectPointerType *getAsObjCInterfacePointerType() const;
const ObjCObjectPointerType *getAsObjCQualifiedIdType() const;
const ObjCObjectPointerType *getAsObjCQualifiedClassType() const;
const ObjCObjectType *getAsObjCQualifiedInterfaceType() const;

/// Retrieves the CXXRecordDecl that this type refers to, either
/// because the type is a RecordType or because it is the injected-class-name
/// type of a class template or class template partial specialization.
CXXRecordDecl *getAsCXXRecordDecl() const;

/// Retrieves the RecordDecl this type refers to.
RecordDecl *getAsRecordDecl() const;

/// Retrieves the TagDecl that this type refers to, either
/// because the type is a TagType or because it is the injected-class-name
/// type of a class template or class template partial specialization.
TagDecl *getAsTagDecl() const;

/// If this is a pointer or reference to a RecordType, return the
/// CXXRecordDecl that the type refers to.
///
/// If this is not a pointer or reference, or the type being pointed to does
/// not refer to a CXXRecordDecl, returns NULL.
const CXXRecordDecl *getPointeeCXXRecordDecl() const;

/// Get the DeducedType whose type will be deduced for a variable with
/// an initializer of this type. This looks through declarators like pointer
/// types, but not through decltype or typedefs.
DeducedType *getContainedDeducedType() const;

/// Get the AutoType whose type will be deduced for a variable with
/// an initializer of this type. This looks through declarators like pointer
/// types, but not through decltype or typedefs.
AutoType *getContainedAutoType() const {
  return dyn_cast_or_null<AutoType>(getContainedDeducedType());
}

/// Determine whether this type was written with a leading 'auto'
/// corresponding to a trailing return type (possibly for a nested
/// function type within a pointer to function type or similar).
bool hasAutoForTrailingReturnType() const;

/// Member-template getAs<specific type>'.  Look through sugar for
/// an instance of \<specific type>.   This scheme will eventually
/// replace the specific getAsXXXX methods above.
///
/// There are some specializations of this member template listed
/// immediately following this class.
template <typename T> const T *getAs() const;

/// Member-template getAsAdjusted<specific type>. Look through specific kinds
/// of sugar (parens, attributes, etc) for an instance of \<specific type>.
/// This is used when you need to walk over sugar nodes that represent some
/// kind of type adjustment from a type that was written as a \<specific type>
/// to another type that is still canonically a \<specific type>.
template <typename T> const T *getAsAdjusted() const;

/// A variant of getAs<> for array types which silently discards
/// qualifiers from the outermost type.
const ArrayType *getAsArrayTypeUnsafe() const;

/// Member-template castAs<specific type>.  Look through sugar for
/// the underlying instance of \<specific type>.
///
/// This method has the same relationship to getAs<T> as cast<T> has
/// 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.
const Type *getArrayElementTypeNoTypeQual() const;

/// If this is a pointer type, return the pointee type.
/// If this is an array type, return the array element type.
/// This should never be used when type qualifiers are meaningful.
const Type *getPointeeOrArrayElementType() const;

/// If this is a pointer, ObjC object pointer, or block
/// pointer, this returns the respective pointee.
QualType getPointeeType() const;

/// Return the specified type with any "sugar" removed from the type,
/// removing any typedefs, typeofs, etc., as well as any qualifiers.
const Type *getUnqualifiedDesugaredType() const;

/// More type predicates useful for type checking/promotion
bool isPromotableIntegerType() const; // C99 6.3.1.1p2

/// Return true if this is an integer type that is
/// signed, according to C99 6.2.5p4 [char, signed char, short, int, long..],
/// or an enum decl which has a signed representation.
bool isSignedIntegerType() const;

/// Return true if this is an integer type that is
/// unsigned, according to C99 6.2.5p6 [which returns true for _Bool],
/// or an enum decl which has an unsigned representation.
bool isUnsignedIntegerType() const;

/// Determines whether this is an integer type that is signed or an
/// enumeration types whose underlying type is a signed integer type.
bool isSignedIntegerOrEnumerationType() const;

/// Determines whether this is an integer type that is unsigned or an
/// enumeration types whose underlying type is a unsigned integer type.
bool isUnsignedIntegerOrEnumerationType() const;

/// Return true if this is a fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169.
bool isFixedPointType() const;

/// Return true if this is a fixed point or integer type.
bool isFixedPointOrIntegerType() const;

/// Return true if this is a saturated fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
bool isSaturatedFixedPointType() const;

/// Return true if this is a saturated fixed point type according to
/// ISO/IEC JTC1 SC22 WG14 N1169. This type can be signed or unsigned.
bool isUnsaturatedFixedPointType() const;

/// Return true if this is a fixed point type that is signed according
/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
bool isSignedFixedPointType() const;

/// Return true if this is a fixed point type that is unsigned according
/// to ISO/IEC JTC1 SC22 WG14 N1169. This type can also be saturated.
bool isUnsignedFixedPointType() const;

/// Return true if this is not a variable sized type,
/// according to the rules of C99 6.7.5p3.  It is not legal to call this on
/// incomplete types.
bool isConstantSizeType() const;

/// Returns true if this type can be represented by some
/// set of type specifiers.
bool isSpecifierType() const;

/// Determine the linkage of this type.
Linkage getLinkage() const;

/// Determine the visibility of this type.
Visibility getVisibility() const {
  return getLinkageAndVisibility().getVisibility();
}

/// Return true if the visibility was explicitly set is the code.
bool isVisibilityExplicit() const {
  return getLinkageAndVisibility().isVisibilityExplicit();
}

/// Determine the linkage and visibility of this type.
LinkageInfo getLinkageAndVisibility() const;

/// True if the computed linkage is valid. Used for consistency
/// checking. Should always return true.
bool isLinkageValid() const;

/// Determine the nullability of the given type.
///
/// Note that nullability is only captured as sugar within the type
/// system, not as part of the canonical type, so nullability will
/// be lost by canonicalization and desugaring.
Optional<NullabilityKind> getNullability(const ASTContext &context) const;

/// Determine whether the given type can have a nullability
/// specifier applied to it, i.e., if it is any kind of pointer type.
///
/// \param ResultIfUnknown The value to return if we don't yet know whether
///        this type can have nullability because it is dependent.
bool canHaveNullability(bool ResultIfUnknown = true) const;

/// Retrieve the set of substitutions required when accessing a member
/// of the Objective-C receiver type that is declared in the given context.
///
/// \c *this is the type of the object we're operating on, e.g., the
/// receiver for a message send or the base of a property access, and is
/// expected to be of some object or object pointer type.
///
/// \param dc The declaration context for which we are building up a
/// substitution mapping, which should be an Objective-C class, extension,
/// category, or method within.
///
/// \returns an array of type arguments that can be substituted for
/// the type parameters of the given declaration context in any type described
/// within that context, or an empty optional to indicate that no
/// substitution is required.
Optional<ArrayRef<QualType>>
getObjCSubstitutions(const DeclContext *dc) const;

/// Determines if this is an ObjC interface type that may accept type
/// parameters.
bool acceptsObjCTypeParams() const;

const char *getTypeClassName() const;

QualType getCanonicalTypeInternal() const {
  return CanonicalType;
}

CanQualType getCanonicalTypeUnqualified() const; // in CanonicalType.h
void dump() const;
void dump(llvm::raw_ostream &OS, const ASTContext &Context) const;
2463};

2465/// This will check for a TypedefType by removing any existing sugar
2466/// until it reaches a TypedefType or a non-sugared type.
2467template <> const TypedefType *Type::getAs() const;

2469/// This will check for a TemplateSpecializationType by removing any
2470/// existing sugar until it reaches a TemplateSpecializationType or a
2471/// non-sugared type.
2472template <> const TemplateSpecializationType *Type::getAs() const;

2474/// This will check for an AttributedType by removing any existing sugar
2475/// until it reaches an AttributedType or a non-sugared type.
2476template <> const AttributedType *Type::getAs() const;

2478// We can do canonical leaf types faster, because we don't have to
2479// worry about preserving child type decoration.
2480#define TYPE(Class, Base)
2481#define LEAF_TYPE(Class) \
2482template <> inline const Class##Type *Type::getAs() const { \
return dyn_cast<Class##Type>(CanonicalType); \
2484} \
2485template <> inline const Class##Type *Type::castAs() const { \
return cast<Class##Type>(CanonicalType); \
2487}
2488#include "clang/AST/TypeNodes.inc"

2490/// This class is used for builtin types like 'int'.  Builtin
2491/// types are always canonical and have a literal name field.
2492class BuiltinType : public Type {
2493public:
enum Kind {
2495// OpenCL image types
2496#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) Id,
2497#include "clang/Basic/OpenCLImageTypes.def"
2498// OpenCL extension types
2499#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) Id,
2500#include "clang/Basic/OpenCLExtensionTypes.def"
2501// SVE Types
2502#define SVE_TYPE(Name, Id, SingletonId) Id,
2503#include "clang/Basic/AArch64SVEACLETypes.def"
2504// PPC MMA Types
2505#define PPC_VECTOR_TYPE(Name, Id, Size) Id,
2506#include "clang/Basic/PPCTypes.def"
2507// RVV Types
2508#define RVV_TYPE(Name, Id, SingletonId) Id,
2509#include "clang/Basic/RISCVVTypes.def"
2510// All other builtin types
2511#define BUILTIN_TYPE(Id, SingletonId) Id,
2512#define LAST_BUILTIN_TYPE(Id) LastKind = Id
2513#include "clang/AST/BuiltinTypes.def"
};

2516private:
friend class ASTContext; // ASTContext creates these.

BuiltinType(Kind K)
    : Type(Builtin, QualType(),
           K == Dependent ? TypeDependence::DependentInstantiation
                          : TypeDependence::None) {
  BuiltinTypeBits.Kind = K;
}

2526public:
Kind getKind() const { return static_cast<Kind>(BuiltinTypeBits.Kind); }
StringRef getName(const PrintingPolicy &Policy) const;

const char *getNameAsCString(const PrintingPolicy &Policy) const {
  // The StringRef is null-terminated.
  StringRef str = getName(Policy);
  assert(!str.empty() && str.data()[str.size()] == '\0')(static_cast<void> (0));
  return str.data();
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

bool isInteger() const {
  return getKind() >= Bool && getKind() <= Int128;
}

bool isSignedInteger() const {
  return getKind() >= Char_S && getKind() <= Int128;
}

bool isUnsignedInteger() const {
  return getKind() >= Bool && getKind() <= UInt128;
}

bool isFloatingPoint() const {
  return getKind() >= Half && getKind() <= Float128;
}

/// Determines whether the given kind corresponds to a placeholder type.
static bool isPlaceholderTypeKind(Kind K) {
  return K >= Overload;
}

/// Determines whether this type is a placeholder type, i.e. a type
/// which cannot appear in arbitrary positions in a fully-formed
/// expression.
bool isPlaceholderType() const {
  return isPlaceholderTypeKind(getKind());
}

/// Determines whether this type is a placeholder type other than
/// Overload.  Most placeholder types require only syntactic
/// information about their context in order to be resolved (e.g.
/// whether it is a call expression), which means they can (and
/// should) be resolved in an earlier "phase" of analysis.
/// Overload expressions sometimes pick up further information
/// from their context, like whether the context expects a
/// specific function-pointer type, and so frequently need
/// special treatment.
bool isNonOverloadPlaceholderType() const {
  return getKind() > Overload;
}

static bool classof(const Type *T) { return T->getTypeClass() == Builtin; }
2582};

2584/// Complex values, per C99 6.2.5p11.  This supports the C99 complex
2585/// types (_Complex float etc) as well as the GCC integer complex extensions.
2586class ComplexType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ElementType;

ComplexType(QualType Element, QualType CanonicalPtr)
    : Type(Complex, CanonicalPtr, Element->getDependence()),
      ElementType(Element) {}

2595public:
QualType getElementType() const { return ElementType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Element) {
  ID.AddPointer(Element.getAsOpaquePtr());
}

static bool classof(const Type *T) { return T->getTypeClass() == Complex; }
2610};

2612/// Sugar for parentheses used when specifying types.
2613class ParenType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType Inner;

ParenType(QualType InnerType, QualType CanonType)
    : Type(Paren, CanonType, InnerType->getDependence()), Inner(InnerType) {}

2621public:
QualType getInnerType() const { return Inner; }

bool isSugared() const { return true; }
QualType desugar() const { return getInnerType(); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getInnerType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Inner) {
  Inner.Profile(ID);
}

static bool classof(const Type *T) { return T->getTypeClass() == Paren; }
2636};

2638/// PointerType - C99 6.7.5.1 - Pointer Declarators.
2639class PointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

PointerType(QualType Pointee, QualType CanonicalPtr)
    : Type(Pointer, CanonicalPtr, Pointee->getDependence()),
      PointeeType(Pointee) {}

2648public:
QualType getPointeeType() const { return PointeeType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
  ID.AddPointer(Pointee.getAsOpaquePtr());
}

static bool classof(const Type *T) { return T->getTypeClass() == Pointer; }
2663};

2665/// Represents a type which was implicitly adjusted by the semantic
2666/// engine for arbitrary reasons.  For example, array and function types can
2667/// decay, and function types can have their calling conventions adjusted.
2668class AdjustedType : public Type, public llvm::FoldingSetNode {
QualType OriginalTy;
QualType AdjustedTy;

2672protected:
friend class ASTContext; // ASTContext creates these.

AdjustedType(TypeClass TC, QualType OriginalTy, QualType AdjustedTy,
             QualType CanonicalPtr)
    : Type(TC, CanonicalPtr, OriginalTy->getDependence()),
      OriginalTy(OriginalTy), AdjustedTy(AdjustedTy) {}

2680public:
QualType getOriginalType() const { return OriginalTy; }
QualType getAdjustedType() const { return AdjustedTy; }

bool isSugared() const { return true; }
QualType desugar() const { return AdjustedTy; }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, OriginalTy, AdjustedTy);
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Orig, QualType New) {
  ID.AddPointer(Orig.getAsOpaquePtr());
  ID.AddPointer(New.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Adjusted || T->getTypeClass() == Decayed;
}
2699};

2701/// Represents a pointer type decayed from an array or function type.
2702class DecayedType : public AdjustedType {
friend class ASTContext; // ASTContext creates these.

inline
DecayedType(QualType OriginalType, QualType Decayed, QualType Canonical);

2708public:
QualType getDecayedType() const { return getAdjustedType(); }

inline QualType getPointeeType() const;

static bool classof(const Type *T) { return T->getTypeClass() == Decayed; }
2714};

2716/// Pointer to a block type.
2717/// This type is to represent types syntactically represented as
2718/// "void (^)(int)", etc. Pointee is required to always be a function type.
2719class BlockPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

// Block is some kind of pointer type
QualType PointeeType;

BlockPointerType(QualType Pointee, QualType CanonicalCls)
    : Type(BlockPointer, CanonicalCls, Pointee->getDependence()),
      PointeeType(Pointee) {}

2729public:
// Get the pointee type. Pointee is required to always be a function type.
QualType getPointeeType() const { return PointeeType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
    Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee) {
    ID.AddPointer(Pointee.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == BlockPointer;
}
2747};

2749/// Base for LValueReferenceType and RValueReferenceType
2750class ReferenceType : public Type, public llvm::FoldingSetNode {
QualType PointeeType;

2753protected:
ReferenceType(TypeClass tc, QualType Referencee, QualType CanonicalRef,
              bool SpelledAsLValue)
    : Type(tc, CanonicalRef, Referencee->getDependence()),
      PointeeType(Referencee) {
  ReferenceTypeBits.SpelledAsLValue = SpelledAsLValue;
  ReferenceTypeBits.InnerRef = Referencee->isReferenceType();
}

2762public:
bool isSpelledAsLValue() const { return ReferenceTypeBits.SpelledAsLValue; }
bool isInnerRef() const { return ReferenceTypeBits.InnerRef; }

QualType getPointeeTypeAsWritten() const { return PointeeType; }

QualType getPointeeType() const {
  // FIXME: this might strip inner qualifiers; okay?
  const ReferenceType *T = this;
  while (T->isInnerRef())
    T = T->PointeeType->castAs<ReferenceType>();
  return T->PointeeType;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, PointeeType, isSpelledAsLValue());
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    QualType Referencee,
                    bool SpelledAsLValue) {
  ID.AddPointer(Referencee.getAsOpaquePtr());
  ID.AddBoolean(SpelledAsLValue);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == LValueReference ||
         T->getTypeClass() == RValueReference;
}
2791};

2793/// An lvalue reference type, per C++11 [dcl.ref].
2794class LValueReferenceType : public ReferenceType {
friend class ASTContext; // ASTContext creates these

LValueReferenceType(QualType Referencee, QualType CanonicalRef,
                    bool SpelledAsLValue)
    : ReferenceType(LValueReference, Referencee, CanonicalRef,
                    SpelledAsLValue) {}

2802public:
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == LValueReference;
}
2809};

2811/// An rvalue reference type, per C++11 [dcl.ref].
2812class RValueReferenceType : public ReferenceType {
friend class ASTContext; // ASTContext creates these

RValueReferenceType(QualType Referencee, QualType CanonicalRef)
     : ReferenceType(RValueReference, Referencee, CanonicalRef, false) {}

2818public:
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == RValueReference;
}
2825};

2827/// A pointer to member type per C++ 8.3.3 - Pointers to members.
2828///
2829/// This includes both pointers to data members and pointer to member functions.
2830class MemberPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

/// The class of which the pointee is a member. Must ultimately be a
/// RecordType, but could be a typedef or a template parameter too.
const Type *Class;

MemberPointerType(QualType Pointee, const Type *Cls, QualType CanonicalPtr)
    : Type(MemberPointer, CanonicalPtr,
           (Cls->getDependence() & ~TypeDependence::VariablyModified) |
               Pointee->getDependence()),
      PointeeType(Pointee), Class(Cls) {}

2845public:
QualType getPointeeType() const { return PointeeType; }

/// Returns true if the member type (i.e. the pointee type) is a
/// function type rather than a data-member type.
bool isMemberFunctionPointer() const {
  return PointeeType->isFunctionProtoType();
}

/// Returns true if the member type (i.e. the pointee type) is a
/// data type rather than a function type.
bool isMemberDataPointer() const {
  return !PointeeType->isFunctionProtoType();
}

const Type *getClass() const { return Class; }
CXXRecordDecl *getMostRecentCXXRecordDecl() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType(), getClass());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pointee,
                    const Type *Class) {
  ID.AddPointer(Pointee.getAsOpaquePtr());
  ID.AddPointer(Class);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == MemberPointer;
}
2879};

2881/// Represents an array type, per C99 6.7.5.2 - Array Declarators.
2882class ArrayType : public Type, public llvm::FoldingSetNode {
2883public:
/// Capture whether this is a normal array (e.g. int X[4])
/// an array with a static size (e.g. int X[static 4]), or an array
/// with a star size (e.g. int X[*]).
/// 'static' is only allowed on function parameters.
enum ArraySizeModifier {
  Normal, Static, Star
};

2892private:
/// The element type of the array.
QualType ElementType;

2896protected:
friend class ASTContext; // ASTContext creates these.

ArrayType(TypeClass tc, QualType et, QualType can, ArraySizeModifier sm,
          unsigned tq, const Expr *sz = nullptr);

2902public:
QualType getElementType() const { return ElementType; }

ArraySizeModifier getSizeModifier() const {
  return ArraySizeModifier(ArrayTypeBits.SizeModifier);
}

Qualifiers getIndexTypeQualifiers() const {
  return Qualifiers::fromCVRMask(getIndexTypeCVRQualifiers());
}

unsigned getIndexTypeCVRQualifiers() const {
  return ArrayTypeBits.IndexTypeQuals;
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantArray ||
         T->getTypeClass() == VariableArray ||
         T->getTypeClass() == IncompleteArray ||
         T->getTypeClass() == DependentSizedArray;
}
2923};

2925/// Represents the canonical version of C arrays with a specified constant size.
2926/// For example, the canonical type for 'int A[4 + 4*100]' is a
2927/// ConstantArrayType where the element type is 'int' and the size is 404.
2928class ConstantArrayType final
  : public ArrayType,
    private llvm::TrailingObjects<ConstantArrayType, const Expr *> {
friend class ASTContext; // ASTContext creates these.
friend TrailingObjects;

llvm::APInt Size; // Allows us to unique the type.

ConstantArrayType(QualType et, QualType can, const llvm::APInt &size,
                  const Expr *sz, ArraySizeModifier sm, unsigned tq)
    : ArrayType(ConstantArray, et, can, sm, tq, sz), Size(size) {
  ConstantArrayTypeBits.HasStoredSizeExpr = sz != nullptr;
  if (ConstantArrayTypeBits.HasStoredSizeExpr) {
    assert(!can.isNull() && "canonical constant array should not have size")(static_cast<void> (0));
    *getTrailingObjects<const Expr*>() = sz;
  }
}

unsigned numTrailingObjects(OverloadToken<const Expr*>) const {
  return ConstantArrayTypeBits.HasStoredSizeExpr;
}

2950public:
const llvm::APInt &getSize() const { return Size; }
const Expr *getSizeExpr() const {
  return ConstantArrayTypeBits.HasStoredSizeExpr
             ? *getTrailingObjects<const Expr *>()
             : nullptr;
}
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

/// Determine the number of bits required to address a member of
// an array with the given element type and number of elements.
static unsigned getNumAddressingBits(const ASTContext &Context,
                                     QualType ElementType,
                                     const llvm::APInt &NumElements);

/// Determine the maximum number of active bits that an array's size
/// can require, which limits the maximum size of the array.
static unsigned getMaxSizeBits(const ASTContext &Context);

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
  Profile(ID, Ctx, getElementType(), getSize(), getSizeExpr(),
          getSizeModifier(), getIndexTypeCVRQualifiers());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx,
                    QualType ET, const llvm::APInt &ArraySize,
                    const Expr *SizeExpr, ArraySizeModifier SizeMod,
                    unsigned TypeQuals);

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantArray;
}
2983};

2985/// Represents a C array with an unspecified size.  For example 'int A[]' has
2986/// an IncompleteArrayType where the element type is 'int' and the size is
2987/// unspecified.
2988class IncompleteArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

IncompleteArrayType(QualType et, QualType can,
                    ArraySizeModifier sm, unsigned tq)
    : ArrayType(IncompleteArray, et, can, sm, tq) {}

2995public:
friend class StmtIteratorBase;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == IncompleteArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getSizeModifier(),
          getIndexTypeCVRQualifiers());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ET,
                    ArraySizeModifier SizeMod, unsigned TypeQuals) {
  ID.AddPointer(ET.getAsOpaquePtr());
  ID.AddInteger(SizeMod);
  ID.AddInteger(TypeQuals);
}
3016};

3018/// Represents a C array with a specified size that is not an
3019/// integer-constant-expression.  For example, 'int s[x+foo()]'.
3020/// Since the size expression is an arbitrary expression, we store it as such.
3021///
3022/// Note: VariableArrayType's aren't uniqued (since the expressions aren't) and
3023/// should not be: two lexically equivalent variable array types could mean
3024/// different things, for example, these variables do not have the same type
3025/// dynamically:
3026///
3027/// void foo(int x) {
3028///   int Y[x];
3029///   ++x;
3030///   int Z[x];
3031/// }
3032class VariableArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

/// An assignment-expression. VLA's are only permitted within
/// a function block.
Stmt *SizeExpr;

/// The range spanned by the left and right array brackets.
SourceRange Brackets;

VariableArrayType(QualType et, QualType can, Expr *e,
                  ArraySizeModifier sm, unsigned tq,
                  SourceRange brackets)
    : ArrayType(VariableArray, et, can, sm, tq, e),
      SizeExpr((Stmt*) e), Brackets(brackets) {}

3048public:
friend class StmtIteratorBase;

Expr *getSizeExpr() const {
  // We use C-style casts instead of cast<> here because we do not wish
  // to have a dependency of Type.h on Stmt.h/Expr.h.
  return (Expr*) SizeExpr;
}

SourceRange getBracketsRange() const { return Brackets; }
SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == VariableArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  llvm_unreachable("Cannot unique VariableArrayTypes.")__builtin_unreachable();
}
3071};

3073/// Represents an array type in C++ whose size is a value-dependent expression.
3074///
3075/// For example:
3076/// \code
3077/// template<typename T, int Size>
3078/// class array {
3079///   T data[Size];
3080/// };
3081/// \endcode
3082///
3083/// For these types, we won't actually know what the array bound is
3084/// until template instantiation occurs, at which point this will
3085/// become either a ConstantArrayType or a VariableArrayType.
3086class DependentSizedArrayType : public ArrayType {
friend class ASTContext; // ASTContext creates these.

const ASTContext &Context;

/// An assignment expression that will instantiate to the
/// size of the array.
///
/// The expression itself might be null, in which case the array
/// type will have its size deduced from an initializer.
Stmt *SizeExpr;

/// The range spanned by the left and right array brackets.
SourceRange Brackets;

DependentSizedArrayType(const ASTContext &Context, QualType et, QualType can,
                        Expr *e, ArraySizeModifier sm, unsigned tq,
                        SourceRange brackets);

3105public:
friend class StmtIteratorBase;

Expr *getSizeExpr() const {
  // We use C-style casts instead of cast<> here because we do not wish
  // to have a dependency of Type.h on Stmt.h/Expr.h.
  return (Expr*) SizeExpr;
}

SourceRange getBracketsRange() const { return Brackets; }
SourceLocation getLBracketLoc() const { return Brackets.getBegin(); }
SourceLocation getRBracketLoc() const { return Brackets.getEnd(); }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedArray;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(),
          getSizeModifier(), getIndexTypeCVRQualifiers(), getSizeExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ET, ArraySizeModifier SizeMod,
                    unsigned TypeQuals, Expr *E);
3133};

3135/// Represents an extended address space qualifier where the input address space
3136/// value is dependent. Non-dependent address spaces are not represented with a
3137/// special Type subclass; they are stored on an ExtQuals node as part of a QualType.
3138///
3139/// For example:
3140/// \code
3141/// template<typename T, int AddrSpace>
3142/// class AddressSpace {
3143///   typedef T __attribute__((address_space(AddrSpace))) type;
3144/// }
3145/// \endcode
3146class DependentAddressSpaceType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
Expr *AddrSpaceExpr;
QualType PointeeType;
SourceLocation loc;

DependentAddressSpaceType(const ASTContext &Context, QualType PointeeType,
                          QualType can, Expr *AddrSpaceExpr,
                          SourceLocation loc);

3158public:
Expr *getAddrSpaceExpr() const { return AddrSpaceExpr; }
QualType getPointeeType() const { return PointeeType; }
SourceLocation getAttributeLoc() const { return loc; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentAddressSpace;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getPointeeType(), getAddrSpaceExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType PointeeType, Expr *AddrSpaceExpr);
3176};

3178/// Represents an extended vector type where either the type or size is
3179/// dependent.
3180///
3181/// For example:
3182/// \code
3183/// template<typename T, int Size>
3184/// class vector {
3185///   typedef T __attribute__((ext_vector_type(Size))) type;
3186/// }
3187/// \endcode
3188class DependentSizedExtVectorType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
Expr *SizeExpr;

/// The element type of the array.
QualType ElementType;

SourceLocation loc;

DependentSizedExtVectorType(const ASTContext &Context, QualType ElementType,
                            QualType can, Expr *SizeExpr, SourceLocation loc);

3202public:
Expr *getSizeExpr() const { return SizeExpr; }
QualType getElementType() const { return ElementType; }
SourceLocation getAttributeLoc() const { return loc; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedExtVector;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getSizeExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, Expr *SizeExpr);
3220};


3223/// Represents a GCC generic vector type. This type is created using
3224/// __attribute__((vector_size(n)), where "n" specifies the vector size in
3225/// bytes; or from an Altivec __vector or vector declaration.
3226/// Since the constructor takes the number of vector elements, the
3227/// client is responsible for converting the size into the number of elements.
3228class VectorType : public Type, public llvm::FoldingSetNode {
3229public:
enum VectorKind {
  /// not a target-specific vector type
  GenericVector,

  /// is AltiVec vector
  AltiVecVector,

  /// is AltiVec 'vector Pixel'
  AltiVecPixel,

  /// is AltiVec 'vector bool ...'
  AltiVecBool,

  /// is ARM Neon vector
  NeonVector,

  /// is ARM Neon polynomial vector
  NeonPolyVector,

  /// is AArch64 SVE fixed-length data vector
  SveFixedLengthDataVector,

  /// is AArch64 SVE fixed-length predicate vector
  SveFixedLengthPredicateVector
};

3256protected:
friend class ASTContext; // ASTContext creates these.

/// The element type of the vector.
QualType ElementType;

VectorType(QualType vecType, unsigned nElements, QualType canonType,
           VectorKind vecKind);

VectorType(TypeClass tc, QualType vecType, unsigned nElements,
           QualType canonType, VectorKind vecKind);

3268public:
QualType getElementType() const { return ElementType; }
unsigned getNumElements() const { return VectorTypeBits.NumElements; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

VectorKind getVectorKind() const {
  return VectorKind(VectorTypeBits.VecKind);
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getNumElements(),
          getTypeClass(), getVectorKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
                    unsigned NumElements, TypeClass TypeClass,
                    VectorKind VecKind) {
  ID.AddPointer(ElementType.getAsOpaquePtr());
  ID.AddInteger(NumElements);
  ID.AddInteger(TypeClass);
  ID.AddInteger(VecKind);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Vector || T->getTypeClass() == ExtVector;
}
3296};

3298/// Represents a vector type where either the type or size is dependent.
3299////
3300/// For example:
3301/// \code
3302/// template<typename T, int Size>
3303/// class vector {
3304///   typedef T __attribute__((vector_size(Size))) type;
3305/// }
3306/// \endcode
3307class DependentVectorType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

const ASTContext &Context;
QualType ElementType;
Expr *SizeExpr;
SourceLocation Loc;

DependentVectorType(const ASTContext &Context, QualType ElementType,
                         QualType CanonType, Expr *SizeExpr,
                         SourceLocation Loc, VectorType::VectorKind vecKind);

3319public:
Expr *getSizeExpr() const { return SizeExpr; }
QualType getElementType() const { return ElementType; }
SourceLocation getAttributeLoc() const { return Loc; }
VectorType::VectorKind getVectorKind() const {
  return VectorType::VectorKind(VectorTypeBits.VecKind);
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentVector;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getSizeExpr(), getVectorKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, const Expr *SizeExpr,
                    VectorType::VectorKind VecKind);
3341};

3343/// ExtVectorType - Extended vector type. This type is created using
3344/// __attribute__((ext_vector_type(n)), where "n" is the number of elements.
3345/// Unlike vector_size, ext_vector_type is only allowed on typedef's. This
3346/// class enables syntactic extensions, like Vector Components for accessing
3347/// points (as .xyzw), colors (as .rgba), and textures (modeled after OpenGL
3348/// Shading Language).
3349class ExtVectorType : public VectorType {
friend class ASTContext; // ASTContext creates these.

ExtVectorType(QualType vecType, unsigned nElements, QualType canonType)
    : VectorType(ExtVector, vecType, nElements, canonType, GenericVector) {}

3355public:
static int getPointAccessorIdx(char c) {
  switch (c) {
  default: return -1;
  case 'x': case 'r': return 0;
  case 'y': case 'g': return 1;
  case 'z': case 'b': return 2;
  case 'w': case 'a': return 3;
  }
}

static int getNumericAccessorIdx(char c) {
  switch (c) {
    default: return -1;
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    case 'A':
    case 'a': return 10;
    case 'B':
    case 'b': return 11;
    case 'C':
    case 'c': return 12;
    case 'D':
    case 'd': return 13;
    case 'E':
    case 'e': return 14;
    case 'F':
    case 'f': return 15;
  }
}

static int getAccessorIdx(char c, bool isNumericAccessor) {
  if (isNumericAccessor)
    return getNumericAccessorIdx(c);
  else
    return getPointAccessorIdx(c);
}

bool isAccessorWithinNumElements(char c, bool isNumericAccessor) const {
  if (int idx = getAccessorIdx(c, isNumericAccessor)+1)
    return unsigned(idx-1) < getNumElements();
  return false;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ExtVector;
}
3413};

3415/// Represents a matrix type, as defined in the Matrix Types clang extensions.
3416/// __attribute__((matrix_type(rows, columns))), where "rows" specifies
3417/// number of rows and "columns" specifies the number of columns.
3418class MatrixType : public Type, public llvm::FoldingSetNode {
3419protected:
friend class ASTContext;

/// The element type of the matrix.
QualType ElementType;

MatrixType(QualType ElementTy, QualType CanonElementTy);

MatrixType(TypeClass TypeClass, QualType ElementTy, QualType CanonElementTy,
           const Expr *RowExpr = nullptr, const Expr *ColumnExpr = nullptr);

3430public:
/// Returns type of the elements being stored in the matrix
QualType getElementType() const { return ElementType; }

/// Valid elements types are the following:
/// * an integer type (as in C2x 6.2.5p19), but excluding enumerated types
///   and _Bool
/// * the standard floating types float or double
/// * a half-precision floating point type, if one is supported on the target
static bool isValidElementType(QualType T) {
  return T->isDependentType() ||
         (T->isRealType() && !T->isBooleanType() && !T->isEnumeralType());
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantMatrix ||
         T->getTypeClass() == DependentSizedMatrix;
}
3451};

3453/// Represents a concrete matrix type with constant number of rows and columns
3454class ConstantMatrixType final : public MatrixType {
3455protected:
friend class ASTContext;

/// Number of rows and columns.
unsigned NumRows;
unsigned NumColumns;

static constexpr unsigned MaxElementsPerDimension = (1 << 20) - 1;

ConstantMatrixType(QualType MatrixElementType, unsigned NRows,
                   unsigned NColumns, QualType CanonElementType);

ConstantMatrixType(TypeClass typeClass, QualType MatrixType, unsigned NRows,
                   unsigned NColumns, QualType CanonElementType);

3470public:
/// Returns the number of rows in the matrix.
unsigned getNumRows() const { return NumRows; }

/// Returns the number of columns in the matrix.
unsigned getNumColumns() const { return NumColumns; }

/// Returns the number of elements required to embed the matrix into a vector.
unsigned getNumElementsFlattened() const {
  return getNumRows() * getNumColumns();
}

/// Returns true if \p NumElements is a valid matrix dimension.
static constexpr bool isDimensionValid(size_t NumElements) {
  return NumElements > 0 && NumElements <= MaxElementsPerDimension;
}

/// Returns the maximum number of elements per dimension.
static constexpr unsigned getMaxElementsPerDimension() {
  return MaxElementsPerDimension;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), getNumRows(), getNumColumns(),
          getTypeClass());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ElementType,
                    unsigned NumRows, unsigned NumColumns,
                    TypeClass TypeClass) {
  ID.AddPointer(ElementType.getAsOpaquePtr());
  ID.AddInteger(NumRows);
  ID.AddInteger(NumColumns);
  ID.AddInteger(TypeClass);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ConstantMatrix;
}
3509};

3511/// Represents a matrix type where the type and the number of rows and columns
3512/// is dependent on a template.
3513class DependentSizedMatrixType final : public MatrixType {
friend class ASTContext;

const ASTContext &Context;
Expr *RowExpr;
Expr *ColumnExpr;

SourceLocation loc;

DependentSizedMatrixType(const ASTContext &Context, QualType ElementType,
                         QualType CanonicalType, Expr *RowExpr,
                         Expr *ColumnExpr, SourceLocation loc);

3526public:
Expr *getRowExpr() const { return RowExpr; }
Expr *getColumnExpr() const { return ColumnExpr; }
SourceLocation getAttributeLoc() const { return loc; }

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentSizedMatrix;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getElementType(), getRowExpr(), getColumnExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType ElementType, Expr *RowExpr, Expr *ColumnExpr);
3541};

3543/// FunctionType - C99 6.7.5.3 - Function Declarators.  This is the common base
3544/// class of FunctionNoProtoType and FunctionProtoType.
3545class FunctionType : public Type {
// The type returned by the function.
QualType ResultType;

3549public:
/// Interesting information about a specific parameter that can't simply
/// be reflected in parameter's type. This is only used by FunctionProtoType
/// but is in FunctionType to make this class available during the
/// specification of the bases of FunctionProtoType.
///
/// It makes sense to model language features this way when there's some
/// sort of parameter-specific override (such as an attribute) that
/// affects how the function is called.  For example, the ARC ns_consumed
/// attribute changes whether a parameter is passed at +0 (the default)
/// or +1 (ns_consumed).  This must be reflected in the function type,
/// but isn't really a change to the parameter type.
///
/// One serious disadvantage of modelling language features this way is
/// that they generally do not work with language features that attempt
/// to destructure types.  For example, template argument deduction will
/// not be able to match a parameter declared as
///   T (*)(U)
/// against an argument of type
///   void (*)(__attribute__((ns_consumed)) id)
/// because the substitution of T=void, U=id into the former will
/// not produce the latter.
class ExtParameterInfo {
  enum {
    ABIMask = 0x0F,
    IsConsumed = 0x10,
    HasPassObjSize = 0x20,
    IsNoEscape = 0x40,
  };
  unsigned char Data = 0;

public:
  ExtParameterInfo() = default;

  /// Return the ABI treatment of this parameter.
  ParameterABI getABI() const { return ParameterABI(Data & ABIMask); }
  ExtParameterInfo withABI(ParameterABI kind) const {
    ExtParameterInfo copy = *this;
    copy.Data = (copy.Data & ~ABIMask) | unsigned(kind);
    return copy;
  }

  /// Is this parameter considered "consumed" by Objective-C ARC?
  /// Consumed parameters must have retainable object type.
  bool isConsumed() const { return (Data & IsConsumed); }
  ExtParameterInfo withIsConsumed(bool consumed) const {
    ExtParameterInfo copy = *this;
    if (consumed)
      copy.Data |= IsConsumed;
    else
      copy.Data &= ~IsConsumed;
    return copy;
  }

  bool hasPassObjectSize() const { return Data & HasPassObjSize; }
  ExtParameterInfo withHasPassObjectSize() const {
    ExtParameterInfo Copy = *this;
    Copy.Data |= HasPassObjSize;
    return Copy;
  }

  bool isNoEscape() const { return Data & IsNoEscape; }
  ExtParameterInfo withIsNoEscape(bool NoEscape) const {
    ExtParameterInfo Copy = *this;
    if (NoEscape)
      Copy.Data |= IsNoEscape;
    else
      Copy.Data &= ~IsNoEscape;
    return Copy;
  }

  unsigned char getOpaqueValue() const { return Data; }
  static ExtParameterInfo getFromOpaqueValue(unsigned char data) {
    ExtParameterInfo result;
    result.Data = data;
    return result;
  }

  friend bool operator==(ExtParameterInfo lhs, ExtParameterInfo rhs) {
    return lhs.Data == rhs.Data;
  }

  friend bool operator!=(ExtParameterInfo lhs, ExtParameterInfo rhs) {
    return lhs.Data != rhs.Data;
  }
};

/// A class which abstracts out some details necessary for
/// making a call.
///
/// It is not actually used directly for storing this information in
/// a FunctionType, although FunctionType does currently use the
/// same bit-pattern.
///
// If you add a field (say Foo), other than the obvious places (both,
// constructors, compile failures), what you need to update is
// * Operator==
// * getFoo
// * withFoo
// * functionType. Add Foo, getFoo.
// * ASTContext::getFooType
// * ASTContext::mergeFunctionTypes
// * FunctionNoProtoType::Profile
// * FunctionProtoType::Profile
// * TypePrinter::PrintFunctionProto
// * AST read and write
// * Codegen
class ExtInfo {
  friend class FunctionType;

  // Feel free to rearrange or add bits, but if you go over 16, you'll need to
  // adjust the Bits field below, and if you add bits, you'll need to adjust
  // Type::FunctionTypeBitfields::ExtInfo as well.

  // |  CC  |noreturn|produces|nocallersavedregs|regparm|nocfcheck|cmsenscall|
  // |0 .. 4|   5    |    6   |       7         |8 .. 10|    11   |    12    |
  //
  // regparm is either 0 (no regparm attribute) or the regparm value+1.
  enum { CallConvMask = 0x1F };
  enum { NoReturnMask = 0x20 };
  enum { ProducesResultMask = 0x40 };
  enum { NoCallerSavedRegsMask = 0x80 };
  enum {
    RegParmMask =  0x700,
    RegParmOffset = 8
  };
  enum { NoCfCheckMask = 0x800 };
  enum { CmseNSCallMask = 0x1000 };
  uint16_t Bits = CC_C;

  ExtInfo(unsigned Bits) : Bits(static_cast<uint16_t>(Bits)) {}

public:
  // Constructor with no defaults. Use this when you know that you
  // have all the elements (when reading an AST file for example).
  ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
          bool producesResult, bool noCallerSavedRegs, bool NoCfCheck,
          bool cmseNSCall) {
    assert((!hasRegParm || regParm < 7) && "Invalid regparm value")(static_cast<void> (0));
    Bits = ((unsigned)cc) | (noReturn ? NoReturnMask : 0) |
           (producesResult ? ProducesResultMask : 0) |
           (noCallerSavedRegs ? NoCallerSavedRegsMask : 0) |
           (hasRegParm ? ((regParm + 1) << RegParmOffset) : 0) |
           (NoCfCheck ? NoCfCheckMask : 0) |
           (cmseNSCall ? CmseNSCallMask : 0);
  }

  // Constructor with all defaults. Use when for example creating a
  // function known to use defaults.
  ExtInfo() = default;

  // Constructor with just the calling convention, which is an important part
  // of the canonical type.
  ExtInfo(CallingConv CC) : Bits(CC) {}

  bool getNoReturn() const { return Bits & NoReturnMask; }
  bool getProducesResult() const { return Bits & ProducesResultMask; }
  bool getCmseNSCall() const { return Bits & CmseNSCallMask; }
  bool getNoCallerSavedRegs() const { return Bits & NoCallerSavedRegsMask; }
  bool getNoCfCheck() const { return Bits & NoCfCheckMask; }
  bool getHasRegParm() const { return ((Bits & RegParmMask) >> RegParmOffset) != 0; }

  unsigned getRegParm() const {
    unsigned RegParm = (Bits & RegParmMask) >> RegParmOffset;
    if (RegParm > 0)
      --RegParm;
    return RegParm;
  }

  CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }

  bool operator==(ExtInfo Other) const {
    return Bits == Other.Bits;
  }
  bool operator!=(ExtInfo Other) const {
    return Bits != Other.Bits;
  }

  // Note that we don't have setters. That is by design, use
  // the following with methods instead of mutating these objects.

  ExtInfo withNoReturn(bool noReturn) const {
    if (noReturn)
      return ExtInfo(Bits | NoReturnMask);
    else
      return ExtInfo(Bits & ~NoReturnMask);
  }

  ExtInfo withProducesResult(bool producesResult) const {
    if (producesResult)
      return ExtInfo(Bits | ProducesResultMask);
    else
      return ExtInfo(Bits & ~ProducesResultMask);
  }

  ExtInfo withCmseNSCall(bool cmseNSCall) const {
    if (cmseNSCall)
      return ExtInfo(Bits | CmseNSCallMask);
    else
      return ExtInfo(Bits & ~CmseNSCallMask);
  }

  ExtInfo withNoCallerSavedRegs(bool noCallerSavedRegs) const {
    if (noCallerSavedRegs)
      return ExtInfo(Bits | NoCallerSavedRegsMask);
    else
      return ExtInfo(Bits & ~NoCallerSavedRegsMask);
  }

  ExtInfo withNoCfCheck(bool noCfCheck) const {
    if (noCfCheck)
      return ExtInfo(Bits | NoCfCheckMask);
    else
      return ExtInfo(Bits & ~NoCfCheckMask);
  }

  ExtInfo withRegParm(unsigned RegParm) const {
    assert(RegParm < 7 && "Invalid regparm value")(static_cast<void> (0));
    return ExtInfo((Bits & ~RegParmMask) |
                   ((RegParm + 1) << RegParmOffset));
  }

  ExtInfo withCallingConv(CallingConv cc) const {
    return ExtInfo((Bits & ~CallConvMask) | (unsigned) cc);
  }

  void Profile(llvm::FoldingSetNodeID &ID) const {
    ID.AddInteger(Bits);
  }
};

/// A simple holder for a QualType representing a type in an
/// exception specification. Unfortunately needed by FunctionProtoType
/// because TrailingObjects cannot handle repeated types.
struct ExceptionType { QualType Type; };

/// A simple holder for various uncommon bits which do not fit in
/// FunctionTypeBitfields. Aligned to alignof(void *) to maintain the
/// alignment of subsequent objects in TrailingObjects. You must update
/// hasExtraBitfields in FunctionProtoType after adding extra data here.
struct alignas(void *) FunctionTypeExtraBitfields {
  /// The number of types in the exception specification.
  /// A whole unsigned is not needed here and according to
  /// [implimits] 8 bits would be enough here.
  unsigned NumExceptionType;
};

3796protected:
FunctionType(TypeClass tc, QualType res, QualType Canonical,
             TypeDependence Dependence, ExtInfo Info)
    : Type(tc, Canonical, Dependence), ResultType(res) {
  FunctionTypeBits.ExtInfo = Info.Bits;
}

Qualifiers getFastTypeQuals() const {
  return Qualifiers::fromFastMask(FunctionTypeBits.FastTypeQuals);
}

3807public:
QualType getReturnType() const { return ResultType; }

bool getHasRegParm() const { return getExtInfo().getHasRegParm(); }
unsigned getRegParmType() const { return getExtInfo().getRegParm(); }

/// Determine whether this function type includes the GNU noreturn
/// attribute. The C++11 [[noreturn]] attribute does not affect the function
/// type.
bool getNoReturnAttr() const { return getExtInfo().getNoReturn(); }

bool getCmseNSCallAttr() const { return getExtInfo().getCmseNSCall(); }
CallingConv getCallConv() const { return getExtInfo().getCC(); }
ExtInfo getExtInfo() const { return ExtInfo(FunctionTypeBits.ExtInfo); }

static_assert((~Qualifiers::FastMask & Qualifiers::CVRMask) == 0,
              "Const, volatile and restrict are assumed to be a subset of "
              "the fast qualifiers.");

bool isConst() const { return getFastTypeQuals().hasConst(); }
bool isVolatile() const { return getFastTypeQuals().hasVolatile(); }
bool isRestrict() const { return getFastTypeQuals().hasRestrict(); }

/// Determine the type of an expression that calls a function of
/// this type.
QualType getCallResultType(const ASTContext &Context) const {
  return getReturnType().getNonLValueExprType(Context);
}

static StringRef getNameForCallConv(CallingConv CC);

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionNoProto ||
         T->getTypeClass() == FunctionProto;
}
3842};

3844/// Represents a K&R-style 'int foo()' function, which has
3845/// no information available about its arguments.
3846class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

FunctionNoProtoType(QualType Result, QualType Canonical, ExtInfo Info)
    : FunctionType(FunctionNoProto, Result, Canonical,
                   Result->getDependence() &
                       ~(TypeDependence::DependentInstantiation |
                         TypeDependence::UnexpandedPack),
                   Info) {}

3856public:
// No additional state past what FunctionType provides.

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getReturnType(), getExtInfo());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType ResultType,
                    ExtInfo Info) {
  Info.Profile(ID);
  ID.AddPointer(ResultType.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionNoProto;
}
3875};

3877/// Represents a prototype with parameter type info, e.g.
3878/// 'int foo(int)' or 'int foo(void)'.  'void' is represented as having no
3879/// parameters, not as having a single void parameter. Such a type can have
3880/// an exception specification, but this specification is not part of the
3881/// canonical type. FunctionProtoType has several trailing objects, some of
3882/// which optional. For more information about the trailing objects see
3883/// the first comment inside FunctionProtoType.
3884class FunctionProtoType final
  : public FunctionType,
    public llvm::FoldingSetNode,
    private llvm::TrailingObjects<
        FunctionProtoType, QualType, SourceLocation,
        FunctionType::FunctionTypeExtraBitfields, FunctionType::ExceptionType,
        Expr *, FunctionDecl *, FunctionType::ExtParameterInfo, Qualifiers> {
friend class ASTContext; // ASTContext creates these.
friend TrailingObjects;

// FunctionProtoType is followed by several trailing objects, some of
// which optional. They are in order:
//
// * An array of getNumParams() QualType holding the parameter types.
//   Always present. Note that for the vast majority of FunctionProtoType,
//   these will be the only trailing objects.
//
// * Optionally if the function is variadic, the SourceLocation of the
//   ellipsis.
//
// * Optionally if some extra data is stored in FunctionTypeExtraBitfields
//   (see FunctionTypeExtraBitfields and FunctionTypeBitfields):
//   a single FunctionTypeExtraBitfields. Present if and only if
//   hasExtraBitfields() is true.
//
// * Optionally exactly one of:
//   * an array of getNumExceptions() ExceptionType,
//   * a single Expr *,
//   * a pair of FunctionDecl *,
//   * a single FunctionDecl *
//   used to store information about the various types of exception
//   specification. See getExceptionSpecSize for the details.
//
// * Optionally an array of getNumParams() ExtParameterInfo holding
//   an ExtParameterInfo for each of the parameters. Present if and
//   only if hasExtParameterInfos() is true.
//
// * Optionally a Qualifiers object to represent extra qualifiers that can't
//   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
//   if hasExtQualifiers() is true.
//
// The optional FunctionTypeExtraBitfields has to be before the data
// related to the exception specification since it contains the number
// of exception types.
//
// We put the ExtParameterInfos last.  If all were equal, it would make
// more sense to put these before the exception specification, because
// it's much easier to skip past them compared to the elaborate switch
// required to skip the exception specification.  However, all is not
// equal; ExtParameterInfos are used to model very uncommon features,
// and it's better not to burden the more common paths.

3936public:
/// Holds information about the various types of exception specification.
/// ExceptionSpecInfo is not stored as such in FunctionProtoType but is
/// used to group together the various bits of information about the
/// exception specification.
struct ExceptionSpecInfo {
  /// The kind of exception specification this is.
  ExceptionSpecificationType Type = EST_None;

  /// Explicitly-specified list of exception types.
  ArrayRef<QualType> Exceptions;

  /// Noexcept expression, if this is a computed noexcept specification.
  Expr *NoexceptExpr = nullptr;

  /// The function whose exception specification this is, for
  /// EST_Unevaluated and EST_Uninstantiated.
  FunctionDecl *SourceDecl = nullptr;

  /// The function template whose exception specification this is instantiated
  /// from, for EST_Uninstantiated.
  FunctionDecl *SourceTemplate = nullptr;

  ExceptionSpecInfo() = default;

  ExceptionSpecInfo(ExceptionSpecificationType EST) : Type(EST) {}
};

/// Extra information about a function prototype. ExtProtoInfo is not
/// stored as such in FunctionProtoType but is used to group together
/// the various bits of extra information about a function prototype.
struct ExtProtoInfo {
  FunctionType::ExtInfo ExtInfo;
  bool Variadic : 1;
  bool HasTrailingReturn : 1;
  Qualifiers TypeQuals;
  RefQualifierKind RefQualifier = RQ_None;
  ExceptionSpecInfo ExceptionSpec;
  const ExtParameterInfo *ExtParameterInfos = nullptr;
  SourceLocation EllipsisLoc;

  ExtProtoInfo() : Variadic(false), HasTrailingReturn(false) {}

  ExtProtoInfo(CallingConv CC)
      : ExtInfo(CC), Variadic(false), HasTrailingReturn(false) {}

  ExtProtoInfo withExceptionSpec(const ExceptionSpecInfo &ESI) {
    ExtProtoInfo Result(*this);
    Result.ExceptionSpec = ESI;
    return Result;
  }
};

3989private:
unsigned numTrailingObjects(OverloadToken<QualType>) const {
  return getNumParams();
}

unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
  return isVariadic();
}

unsigned numTrailingObjects(OverloadToken<FunctionTypeExtraBitfields>) const {
  return hasExtraBitfields();
}

unsigned numTrailingObjects(OverloadToken<ExceptionType>) const {
  return getExceptionSpecSize().NumExceptionType;
}

unsigned numTrailingObjects(OverloadToken<Expr *>) const {
  return getExceptionSpecSize().NumExprPtr;
}

unsigned numTrailingObjects(OverloadToken<FunctionDecl *>) const {
  return getExceptionSpecSize().NumFunctionDeclPtr;
}

unsigned numTrailingObjects(OverloadToken<ExtParameterInfo>) const {
  return hasExtParameterInfos() ? getNumParams() : 0;
}

/// Determine whether there are any argument types that
/// contain an unexpanded parameter pack.
static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
                                               unsigned numArgs) {
  for (unsigned Idx = 0; Idx < numArgs; ++Idx)
    if (ArgArray[Idx]->containsUnexpandedParameterPack())
      return true;

  return false;
}

FunctionProtoType(QualType result, ArrayRef<QualType> params,
                  QualType canonical, const ExtProtoInfo &epi);

/// This struct is returned by getExceptionSpecSize and is used to
/// translate an ExceptionSpecificationType to the number and kind
/// of trailing objects related to the exception specification.
struct ExceptionSpecSizeHolder {
  unsigned NumExceptionType;
  unsigned NumExprPtr;
  unsigned NumFunctionDeclPtr;
};

/// Return the number and kind of trailing objects
/// related to the exception specification.
static ExceptionSpecSizeHolder
getExceptionSpecSize(ExceptionSpecificationType EST, unsigned NumExceptions) {
  switch (EST) {
  case EST_None:
  case EST_DynamicNone:
  case EST_MSAny:
  case EST_BasicNoexcept:
  case EST_Unparsed:
  case EST_NoThrow:
    return {0, 0, 0};

  case EST_Dynamic:
    return {NumExceptions, 0, 0};

  case EST_DependentNoexcept:
  case EST_NoexceptFalse:
  case EST_NoexceptTrue:
    return {0, 1, 0};

  case EST_Uninstantiated:
    return {0, 0, 2};

  case EST_Unevaluated:
    return {0, 0, 1};
  }
  llvm_unreachable("bad exception specification kind")__builtin_unreachable();
}

/// Return the number and kind of trailing objects
/// related to the exception specification.
ExceptionSpecSizeHolder getExceptionSpecSize() const {
  return getExceptionSpecSize(getExceptionSpecType(), getNumExceptions());
}

/// Whether the trailing FunctionTypeExtraBitfields is present.
static bool hasExtraBitfields(ExceptionSpecificationType EST) {
  // If the exception spec type is EST_Dynamic then we have > 0 exception
  // types and the exact number is stored in FunctionTypeExtraBitfields.
  return EST == EST_Dynamic;
}

/// Whether the trailing FunctionTypeExtraBitfields is present.
bool hasExtraBitfields() const {
  return hasExtraBitfields(getExceptionSpecType());
}

bool hasExtQualifiers() const {
  return FunctionTypeBits.HasExtQuals;
}

4093public:
unsigned getNumParams() const { return FunctionTypeBits.NumParams; }

QualType getParamType(unsigned i) const {
  assert(i < getNumParams() && "invalid parameter index")(static_cast<void> (0));
  return param_type_begin()[i];
}

ArrayRef<QualType> getParamTypes() const {
  return llvm::makeArrayRef(param_type_begin(), param_type_end());
}

ExtProtoInfo getExtProtoInfo() const {
  ExtProtoInfo EPI;
  EPI.ExtInfo = getExtInfo();
  EPI.Variadic = isVariadic();
  EPI.EllipsisLoc = getEllipsisLoc();
  EPI.HasTrailingReturn = hasTrailingReturn();
  EPI.ExceptionSpec = getExceptionSpecInfo();
  EPI.TypeQuals = getMethodQuals();
  EPI.RefQualifier = getRefQualifier();
  EPI.ExtParameterInfos = getExtParameterInfosOrNull();
  return EPI;
}

/// Get the kind of exception specification on this function.
ExceptionSpecificationType getExceptionSpecType() const {
  return static_cast<ExceptionSpecificationType>(
      FunctionTypeBits.ExceptionSpecType);
}

/// Return whether this function has any kind of exception spec.
bool hasExceptionSpec() const { return getExceptionSpecType() != EST_None; }

/// Return whether this function has a dynamic (throw) exception spec.
bool hasDynamicExceptionSpec() const {
  return isDynamicExceptionSpec(getExceptionSpecType());
}

/// Return whether this function has a noexcept exception spec.
bool hasNoexceptExceptionSpec() const {
  return isNoexceptExceptionSpec(getExceptionSpecType());
}

/// Return whether this function has a dependent exception spec.
bool hasDependentExceptionSpec() const;

/// Return whether this function has an instantiation-dependent exception
/// spec.
bool hasInstantiationDependentExceptionSpec() const;

/// Return all the available information about this type's exception spec.
ExceptionSpecInfo getExceptionSpecInfo() const {
  ExceptionSpecInfo Result;
  Result.Type = getExceptionSpecType();
  if (Result.Type == EST_Dynamic) {
    Result.Exceptions = exceptions();
  } else if (isComputedNoexcept(Result.Type)) {
    Result.NoexceptExpr = getNoexceptExpr();
  } else if (Result.Type == EST_Uninstantiated) {
    Result.SourceDecl = getExceptionSpecDecl();
    Result.SourceTemplate = getExceptionSpecTemplate();
  } else if (Result.Type == EST_Unevaluated) {
    Result.SourceDecl = getExceptionSpecDecl();
  }
  return Result;
}

/// Return the number of types in the exception specification.
unsigned getNumExceptions() const {
  return getExceptionSpecType() == EST_Dynamic
             ? getTrailingObjects<FunctionTypeExtraBitfields>()
                   ->NumExceptionType
             : 0;
}

/// Return the ith exception type, where 0 <= i < getNumExceptions().
QualType getExceptionType(unsigned i) const {
  assert(i < getNumExceptions() && "Invalid exception number!")(static_cast<void> (0));
  return exception_begin()[i];
}

/// Return the expression inside noexcept(expression), or a null pointer
/// if there is none (because the exception spec is not of this form).
Expr *getNoexceptExpr() const {
  if (!isComputedNoexcept(getExceptionSpecType()))
    return nullptr;
  return *getTrailingObjects<Expr *>();
}

/// If this function type has an exception specification which hasn't
/// been determined yet (either because it has not been evaluated or because
/// it has not been instantiated), this is the function whose exception
/// specification is represented by this type.
FunctionDecl *getExceptionSpecDecl() const {
  if (getExceptionSpecType() != EST_Uninstantiated &&
      getExceptionSpecType() != EST_Unevaluated)
    return nullptr;
  return getTrailingObjects<FunctionDecl *>()[0];
}

/// If this function type has an uninstantiated exception
/// specification, this is the function whose exception specification
/// should be instantiated to find the exception specification for
/// this type.
FunctionDecl *getExceptionSpecTemplate() const {
  if (getExceptionSpecType() != EST_Uninstantiated)
    return nullptr;
  return getTrailingObjects<FunctionDecl *>()[1];
}

/// Determine whether this function type has a non-throwing exception
/// specification.
CanThrowResult canThrow() const;

/// Determine whether this function type has a non-throwing exception
/// specification. If this depends on template arguments, returns
/// \c ResultIfDependent.
bool isNothrow(bool ResultIfDependent = false) const {
  return ResultIfDependent ? canThrow() != CT_Can : canThrow() == CT_Cannot;
}

/// Whether this function prototype is variadic.
bool isVariadic() const { return FunctionTypeBits.Variadic; }

SourceLocation getEllipsisLoc() const {
  return isVariadic() ? *getTrailingObjects<SourceLocation>()
                      : SourceLocation();
}

/// Determines whether this function prototype contains a
/// parameter pack at the end.
///
/// A function template whose last parameter is a parameter pack can be
/// called with an arbitrary number of arguments, much like a variadic
/// function.
bool isTemplateVariadic() const;

/// Whether this function prototype has a trailing return type.
bool hasTrailingReturn() const { return FunctionTypeBits.HasTrailingReturn; }

Qualifiers getMethodQuals() const {
  if (hasExtQualifiers())
    return *getTrailingObjects<Qualifiers>();
  else
    return getFastTypeQuals();
}

/// Retrieve the ref-qualifier associated with this function type.
RefQualifierKind getRefQualifier() const {
  return static_cast<RefQualifierKind>(FunctionTypeBits.RefQualifier);
}

using param_type_iterator = const QualType *;
using param_type_range = llvm::iterator_range<param_type_iterator>;

param_type_range param_types() const {
  return param_type_range(param_type_begin(), param_type_end());
}

param_type_iterator param_type_begin() const {
  return getTrailingObjects<QualType>();
}

param_type_iterator param_type_end() const {
  return param_type_begin() + getNumParams();
}

using exception_iterator = const QualType *;

ArrayRef<QualType> exceptions() const {
  return llvm::makeArrayRef(exception_begin(), exception_end());
}

exception_iterator exception_begin() const {
  return reinterpret_cast<exception_iterator>(
      getTrailingObjects<ExceptionType>());
}

exception_iterator exception_end() const {
  return exception_begin() + getNumExceptions();
}

/// Is there any interesting extra information for any of the parameters
/// of this function type?
bool hasExtParameterInfos() const {
  return FunctionTypeBits.HasExtParameterInfos;
}

ArrayRef<ExtParameterInfo> getExtParameterInfos() const {
  assert(hasExtParameterInfos())(static_cast<void> (0));
  return ArrayRef<ExtParameterInfo>(getTrailingObjects<ExtParameterInfo>(),
                                    getNumParams());
}

/// Return a pointer to the beginning of the array of extra parameter
/// information, if present, or else null if none of the parameters
/// carry it.  This is equivalent to getExtProtoInfo().ExtParameterInfos.
const ExtParameterInfo *getExtParameterInfosOrNull() const {
  if (!hasExtParameterInfos())
    return nullptr;
  return getTrailingObjects<ExtParameterInfo>();
}

ExtParameterInfo getExtParameterInfo(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I];
  return ExtParameterInfo();
}

ParameterABI getParameterABI(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I].getABI();
  return ParameterABI::Ordinary;
}

bool isParamConsumed(unsigned I) const {
  assert(I < getNumParams() && "parameter index out of range")(static_cast<void> (0));
  if (hasExtParameterInfos())
    return getTrailingObjects<ExtParameterInfo>()[I].isConsumed();
  return false;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void printExceptionSpecification(raw_ostream &OS,
                                 const PrintingPolicy &Policy) const;

static bool classof(const Type *T) {
  return T->getTypeClass() == FunctionProto;
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx);
static void Profile(llvm::FoldingSetNodeID &ID, QualType Result,
                    param_type_iterator ArgTys, unsigned NumArgs,
                    const ExtProtoInfo &EPI, const ASTContext &Context,
                    bool Canonical);
4333};

4335/// Represents the dependent type named by a dependently-scoped
4336/// typename using declaration, e.g.
4337///   using typename Base<T>::foo;
4338///
4339/// Template instantiation turns these into the underlying type.
4340class UnresolvedUsingType : public Type {
friend class ASTContext; // ASTContext creates these.

UnresolvedUsingTypenameDecl *Decl;

UnresolvedUsingType(const UnresolvedUsingTypenameDecl *D)
    : Type(UnresolvedUsing, QualType(),
           TypeDependence::DependentInstantiation),
      Decl(const_cast<UnresolvedUsingTypenameDecl *>(D)) {}

4350public:
UnresolvedUsingTypenameDecl *getDecl() const { return Decl; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == UnresolvedUsing;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  return Profile(ID, Decl);
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    UnresolvedUsingTypenameDecl *D) {
  ID.AddPointer(D);
}
4368};

4370class TypedefType : public Type {
TypedefNameDecl *Decl;

4373private:
friend class ASTContext; // ASTContext creates these.

TypedefType(TypeClass tc, const TypedefNameDecl *D, QualType underlying,
            QualType can);

4379public:
TypedefNameDecl *getDecl() const { return Decl; }

bool isSugared() const { return true; }
QualType desugar() const;

static bool classof(const Type *T) { return T->getTypeClass() == Typedef; }
4386};

4388/// Sugar type that represents a type that was qualified by a qualifier written
4389/// as a macro invocation.
4390class MacroQualifiedType : public Type {
friend class ASTContext; // ASTContext creates these.

QualType UnderlyingTy;
const IdentifierInfo *MacroII;

MacroQualifiedType(QualType UnderlyingTy, QualType CanonTy,
                   const IdentifierInfo *MacroII)
    : Type(MacroQualified, CanonTy, UnderlyingTy->getDependence()),
      UnderlyingTy(UnderlyingTy), MacroII(MacroII) {
  assert(isa<AttributedType>(UnderlyingTy) &&(static_cast<void> (0))
         "Expected a macro qualified type to only wrap attributed types.")(static_cast<void> (0));
}

4404public:
const IdentifierInfo *getMacroIdentifier() const { return MacroII; }
QualType getUnderlyingType() const { return UnderlyingTy; }

/// Return this attributed type's modified type with no qualifiers attached to
/// it.
QualType getModifiedType() const;

bool isSugared() const { return true; }
QualType desugar() const;

static bool classof(const Type *T) {
  return T->getTypeClass() == MacroQualified;
}
4418};

4420/// Represents a `typeof` (or __typeof__) expression (a GCC extension).
4421class TypeOfExprType : public Type {
Expr *TOExpr;

4424protected:
friend class ASTContext; // ASTContext creates these.

TypeOfExprType(Expr *E, QualType can = QualType());

4429public:
Expr *getUnderlyingExpr() const { return TOExpr; }

/// Remove a single level of sugar.
QualType desugar() const;

/// Returns whether this type directly provides sugar.
bool isSugared() const;

static bool classof(const Type *T) { return T->getTypeClass() == TypeOfExpr; }
4439};

4441/// Internal representation of canonical, dependent
4442/// `typeof(expr)` types.
4443///
4444/// This class is used internally by the ASTContext to manage
4445/// canonical, dependent types, only. Clients will only see instances
4446/// of this class via TypeOfExprType nodes.
4447class DependentTypeOfExprType
: public TypeOfExprType, public llvm::FoldingSetNode {
const ASTContext &Context;

4451public:
DependentTypeOfExprType(const ASTContext &Context, Expr *E)
    : TypeOfExprType(E), Context(Context) {}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getUnderlyingExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    Expr *E);
4461};

4463/// Represents `typeof(type)`, a GCC extension.
4464class TypeOfType : public Type {
friend class ASTContext; // ASTContext creates these.

QualType TOType;

TypeOfType(QualType T, QualType can)
    : Type(TypeOf, can, T->getDependence()), TOType(T) {
  assert(!isa<TypedefType>(can) && "Invalid canonical type")(static_cast<void> (0));
}

4474public:
QualType getUnderlyingType() const { return TOType; }

/// Remove a single level of sugar.
QualType desugar() const { return getUnderlyingType(); }

/// Returns whether this type directly provides sugar.
bool isSugared() const { return true; }

static bool classof(const Type *T) { return T->getTypeClass() == TypeOf; }
4484};

4486/// Represents the type `decltype(expr)` (C++11).
4487class DecltypeType : public Type {
Expr *E;
QualType UnderlyingType;

4491protected:
friend class ASTContext; // ASTContext creates these.

DecltypeType(Expr *E, QualType underlyingType, QualType can = QualType());

4496public:
Expr *getUnderlyingExpr() const { return E; }
QualType getUnderlyingType() const { return UnderlyingType; }

/// Remove a single level of sugar.
QualType desugar() const;

/// Returns whether this type directly provides sugar.
bool isSugared() const;

static bool classof(const Type *T) { return T->getTypeClass() == Decltype; }
4507};

4509/// Internal representation of canonical, dependent
4510/// decltype(expr) types.
4511///
4512/// This class is used internally by the ASTContext to manage
4513/// canonical, dependent types, only. Clients will only see instances
4514/// of this class via DecltypeType nodes.
4515class DependentDecltypeType : public DecltypeType, public llvm::FoldingSetNode {
const ASTContext &Context;

4518public:
DependentDecltypeType(const ASTContext &Context, Expr *E);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, getUnderlyingExpr());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    Expr *E);
4527};

4529/// A unary type transform, which is a type constructed from another.
4530class UnaryTransformType : public Type {
4531public:
enum UTTKind {
  EnumUnderlyingType
};

4536private:
/// The untransformed type.
QualType BaseType;

/// The transformed type if not dependent, otherwise the same as BaseType.
QualType UnderlyingType;

UTTKind UKind;

4545protected:
friend class ASTContext;

UnaryTransformType(QualType BaseTy, QualType UnderlyingTy, UTTKind UKind,
                   QualType CanonicalTy);

4551public:
bool isSugared() const { return !isDependentType(); }
QualType desugar() const { return UnderlyingType; }

QualType getUnderlyingType() const { return UnderlyingType; }
QualType getBaseType() const { return BaseType; }

UTTKind getUTTKind() const { return UKind; }

static bool classof(const Type *T) {
  return T->getTypeClass() == UnaryTransform;
}
4563};

4565/// Internal representation of canonical, dependent
4566/// __underlying_type(type) types.
4567///
4568/// This class is used internally by the ASTContext to manage
4569/// canonical, dependent types, only. Clients will only see instances
4570/// of this class via UnaryTransformType nodes.
4571class DependentUnaryTransformType : public UnaryTransformType,
                                  public llvm::FoldingSetNode {
4573public:
DependentUnaryTransformType(const ASTContext &C, QualType BaseType,
                            UTTKind UKind);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getBaseType(), getUTTKind());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType BaseType,
                    UTTKind UKind) {
  ID.AddPointer(BaseType.getAsOpaquePtr());
  ID.AddInteger((unsigned)UKind);
}
4586};

4588class TagType : public Type {
friend class ASTReader;
template <class T> friend class serialization::AbstractTypeReader;

/// Stores the TagDecl associated with this type. The decl may point to any
/// TagDecl that declares the entity.
TagDecl *decl;

4596protected:
TagType(TypeClass TC, const TagDecl *D, QualType can);

4599public:
TagDecl *getDecl() const;

/// Determines whether this type is in the process of being defined.
bool isBeingDefined() const;

static bool classof(const Type *T) {
  return T->getTypeClass() == Enum || T->getTypeClass() == Record;
}
4608};

4610/// A helper class that allows the use of isa/cast/dyncast
4611/// to detect TagType objects of structs/unions/classes.
4612class RecordType : public TagType {
4613protected:
friend class ASTContext; // ASTContext creates these.

explicit RecordType(const RecordDecl *D)
    : TagType(Record, reinterpret_cast<const TagDecl*>(D), QualType()) {}
explicit RecordType(TypeClass TC, RecordDecl *D)
    : TagType(TC, reinterpret_cast<const TagDecl*>(D), QualType()) {}

4621public:
RecordDecl *getDecl() const {
  return reinterpret_cast<RecordDecl*>(TagType::getDecl());
}

/// Recursively check all fields in the record for const-ness. If any field
/// is declared const, return true. Otherwise, return false.
bool hasConstFields() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) { return T->getTypeClass() == Record; }
4634};

4636/// A helper class that allows the use of isa/cast/dyncast
4637/// to detect TagType objects of enums.
4638class EnumType : public TagType {
friend class ASTContext; // ASTContext creates these.

explicit EnumType(const EnumDecl *D)
    : TagType(Enum, reinterpret_cast<const TagDecl*>(D), QualType()) {}

4644public:
EnumDecl *getDecl() const {
  return reinterpret_cast<EnumDecl*>(TagType::getDecl());
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) { return T->getTypeClass() == Enum; }
4653};

4655/// An attributed type is a type to which a type attribute has been applied.
4656///
4657/// The "modified type" is the fully-sugared type to which the attributed
4658/// type was applied; generally it is not canonically equivalent to the
4659/// attributed type. The "equivalent type" is the minimally-desugared type
4660/// which the type is canonically equivalent to.
4661///
4662/// For example, in the following attributed type:
4663///     int32_t __attribute__((vector_size(16)))
4664///   - the modified type is the TypedefType for int32_t
4665///   - the equivalent type is VectorType(16, int32_t)
4666///   - the canonical type is VectorType(16, int)
4667class AttributedType : public Type, public llvm::FoldingSetNode {
4668public:
using Kind = attr::Kind;

4671private:
friend class ASTContext; // ASTContext creates these

QualType ModifiedType;
QualType EquivalentType;

AttributedType(QualType canon, attr::Kind attrKind, QualType modified,
               QualType equivalent)
    : Type(Attributed, canon, equivalent->getDependence()),
      ModifiedType(modified), EquivalentType(equivalent) {
  AttributedTypeBits.AttrKind = attrKind;
}

4684public:
Kind getAttrKind() const {
  return static_cast<Kind>(AttributedTypeBits.AttrKind);
}

QualType getModifiedType() const { return ModifiedType; }
QualType getEquivalentType() const { return EquivalentType; }

bool isSugared() const { return true; }
QualType desugar() const { return getEquivalentType(); }

/// Does this attribute behave like a type qualifier?
///
/// A type qualifier adjusts a type to provide specialized rules for
/// a specific object, like the standard const and volatile qualifiers.
/// This includes attributes controlling things like nullability,
/// address spaces, and ARC ownership.  The value of the object is still
/// largely described by the modified type.
///
/// In contrast, many type attributes "rewrite" their modified type to
/// produce a fundamentally different type, not necessarily related in any
/// formalizable way to the original type.  For example, calling convention
/// and vector attributes are not simple type qualifiers.
///
/// Type qualifiers are often, but not always, reflected in the canonical
/// type.
bool isQualifier() const;

bool isMSTypeSpec() const;

bool isCallingConv() const;

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::TypeNonNull;

  case NullabilityKind::Nullable:
    return attr::TypeNullable;

  case NullabilityKind::NullableResult:
    return attr::TypeNullableResult;

  case NullabilityKind::Unspecified:
    return attr::TypeNullUnspecified;
  }
  llvm_unreachable("Unknown nullability kind.")__builtin_unreachable();
}

/// 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
/// AttributedType specifying nullability (without looking through
/// type sugar), the nullability is returned and this type changed
/// to the underlying modified type.
///
/// \returns the top-level nullability, if present.
static Optional<NullabilityKind> stripOuterNullability(QualType &T);

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getAttrKind(), ModifiedType, EquivalentType);
}

static void Profile(llvm::FoldingSetNodeID &ID, Kind attrKind,
                    QualType modified, QualType equivalent) {
  ID.AddInteger(attrKind);
  ID.AddPointer(modified.getAsOpaquePtr());
  ID.AddPointer(equivalent.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Attributed;
}
4762};

4764class TemplateTypeParmType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

// Helper data collector for canonical types.
struct CanonicalTTPTInfo {
  unsigned Depth : 15;
  unsigned ParameterPack : 1;
  unsigned Index : 16;
};

union {
  // Info for the canonical type.
  CanonicalTTPTInfo CanTTPTInfo;

  // Info for the non-canonical type.
  TemplateTypeParmDecl *TTPDecl;
};

/// Build a non-canonical type.
TemplateTypeParmType(TemplateTypeParmDecl *TTPDecl, QualType Canon)
    : Type(TemplateTypeParm, Canon,
           TypeDependence::DependentInstantiation |
               (Canon->getDependence() & TypeDependence::UnexpandedPack)),
      TTPDecl(TTPDecl) {}

/// Build the canonical type.
TemplateTypeParmType(unsigned D, unsigned I, bool PP)
    : Type(TemplateTypeParm, QualType(this, 0),
           TypeDependence::DependentInstantiation |
               (PP ? TypeDependence::UnexpandedPack : TypeDependence::None)) {
  CanTTPTInfo.Depth = D;
  CanTTPTInfo.Index = I;
  CanTTPTInfo.ParameterPack = PP;
}

const CanonicalTTPTInfo& getCanTTPTInfo() const {
  QualType Can = getCanonicalTypeInternal();
  return Can->castAs<TemplateTypeParmType>()->CanTTPTInfo;
}

4804public:
unsigned getDepth() const { return getCanTTPTInfo().Depth; }
unsigned getIndex() const { return getCanTTPTInfo().Index; }
bool isParameterPack() const { return getCanTTPTInfo().ParameterPack; }

TemplateTypeParmDecl *getDecl() const {
  return isCanonicalUnqualified() ? nullptr : TTPDecl;
}

IdentifierInfo *getIdentifier() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getDepth(), getIndex(), isParameterPack(), getDecl());
}

static void Profile(llvm::FoldingSetNodeID &ID, unsigned Depth,
                    unsigned Index, bool ParameterPack,
                    TemplateTypeParmDecl *TTPDecl) {
  ID.AddInteger(Depth);
  ID.AddInteger(Index);
  ID.AddBoolean(ParameterPack);
  ID.AddPointer(TTPDecl);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == TemplateTypeParm;
}
4834};

4836/// Represents the result of substituting a type for a template
4837/// type parameter.
4838///
4839/// Within an instantiated template, all template type parameters have
4840/// been replaced with these.  They are used solely to record that a
4841/// type was originally written as a template type parameter;
4842/// therefore they are never canonical.
4843class SubstTemplateTypeParmType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

// The original type parameter.
const TemplateTypeParmType *Replaced;

SubstTemplateTypeParmType(const TemplateTypeParmType *Param, QualType Canon)
    : Type(SubstTemplateTypeParm, Canon, Canon->getDependence()),
      Replaced(Param) {}

4853public:
/// Gets the template parameter that was substituted for.
const TemplateTypeParmType *getReplacedParameter() const {
  return Replaced;
}

/// Gets the type that was substituted for the template
/// parameter.
QualType getReplacementType() const {
  return getCanonicalTypeInternal();
}

bool isSugared() const { return true; }
QualType desugar() const { return getReplacementType(); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getReplacedParameter(), getReplacementType());
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const TemplateTypeParmType *Replaced,
                    QualType Replacement) {
  ID.AddPointer(Replaced);
  ID.AddPointer(Replacement.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == SubstTemplateTypeParm;
}
4882};

4884/// Represents the result of substituting a set of types for a template
4885/// type parameter pack.
4886///
4887/// When a pack expansion in the source code contains multiple parameter packs
4888/// and those parameter packs correspond to different levels of template
4889/// parameter lists, this type node is used to represent a template type
4890/// parameter pack from an outer level, which has already had its argument pack
4891/// substituted but that still lives within a pack expansion that itself
4892/// could not be instantiated. When actually performing a substitution into
4893/// that pack expansion (e.g., when all template parameters have corresponding
4894/// arguments), this type will be replaced with the \c SubstTemplateTypeParmType
4895/// at the current pack substitution index.
4896class SubstTemplateTypeParmPackType : public Type, public llvm::FoldingSetNode {
friend class ASTContext;

/// The original type parameter.
const TemplateTypeParmType *Replaced;

/// A pointer to the set of template arguments that this
/// parameter pack is instantiated with.
const TemplateArgument *Arguments;

SubstTemplateTypeParmPackType(const TemplateTypeParmType *Param,
                              QualType Canon,
                              const TemplateArgument &ArgPack);

4910public:
IdentifierInfo *getIdentifier() const { return Replaced->getIdentifier(); }

/// Gets the template parameter that was substituted for.
const TemplateTypeParmType *getReplacedParameter() const {
  return Replaced;
}

unsigned getNumArgs() const {
  return SubstTemplateTypeParmPackTypeBits.NumArgs;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

TemplateArgument getArgumentPack() const;

void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    const TemplateTypeParmType *Replaced,
                    const TemplateArgument &ArgPack);

static bool classof(const Type *T) {
  return T->getTypeClass() == SubstTemplateTypeParmPack;
}
4935};

4937/// Common base class for placeholders for types that get replaced by
4938/// placeholder type deduction: C++11 auto, C++14 decltype(auto), C++17 deduced
4939/// class template types, and constrained type names.
4940///
4941/// These types are usually a placeholder for a deduced type. However, before
4942/// the initializer is attached, or (usually) if the initializer is
4943/// type-dependent, there is no deduced type and the type is canonical. In
4944/// the latter case, it is also a dependent type.
4945class DeducedType : public Type {
4946protected:
DeducedType(TypeClass TC, QualType DeducedAsType,
            TypeDependence ExtraDependence)
    : Type(TC,
           // FIXME: Retain the sugared deduced type?
           DeducedAsType.isNull() ? QualType(this, 0)
                                  : DeducedAsType.getCanonicalType(),
           ExtraDependence | (DeducedAsType.isNull()
                                  ? TypeDependence::None
                                  : DeducedAsType->getDependence() &
                                        ~TypeDependence::VariablyModified)) {}

4958public:
bool isSugared() const { return !isCanonicalUnqualified(); }
QualType desugar() const { return getCanonicalTypeInternal(); }

/// Get the type deduced for this placeholder type, or null if it's
/// either not been deduced or was deduced to a dependent type.
QualType getDeducedType() const {
  return !isCanonicalUnqualified() ? getCanonicalTypeInternal() : QualType();
}
bool isDeduced() const {
  return !isCanonicalUnqualified() || isDependentType();
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Auto ||
         T->getTypeClass() == DeducedTemplateSpecialization;
}
4975};

4977/// Represents a C++11 auto or C++14 decltype(auto) type, possibly constrained
4978/// by a type-constraint.
4979class alignas(8) AutoType : public DeducedType, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

ConceptDecl *TypeConstraintConcept;

AutoType(QualType DeducedAsType, AutoTypeKeyword Keyword,
         TypeDependence ExtraDependence, ConceptDecl *CD,
         ArrayRef<TemplateArgument> TypeConstraintArgs);

const TemplateArgument *getArgBuffer() const {
  return reinterpret_cast<const TemplateArgument*>(this+1);
}

TemplateArgument *getArgBuffer() {
  return reinterpret_cast<TemplateArgument*>(this+1);
}

4996public:
/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return getArgBuffer();
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return AutoTypeBits.NumArgs;
}

const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> getTypeConstraintArguments() const {
  return {getArgs(), getNumArgs()};
}

ConceptDecl *getTypeConstraintConcept() const {
  return TypeConstraintConcept;
}

bool isConstrained() const {
  return TypeConstraintConcept != nullptr;
}

bool isDecltypeAuto() const {
  return getKeyword() == AutoTypeKeyword::DecltypeAuto;
}

AutoTypeKeyword getKeyword() const {
  return (AutoTypeKeyword)AutoTypeBits.Keyword;
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
  Profile(ID, Context, getDeducedType(), getKeyword(), isDependentType(),
          getTypeConstraintConcept(), getTypeConstraintArguments());
}

static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    QualType Deduced, AutoTypeKeyword Keyword,
                    bool IsDependent, ConceptDecl *CD,
                    ArrayRef<TemplateArgument> Arguments);

static bool classof(const Type *T) {
  return T->getTypeClass() == Auto;
}
5042};

5044/// Represents a C++17 deduced template specialization type.
5045class DeducedTemplateSpecializationType : public DeducedType,
                                        public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The name of the template whose arguments will be deduced.
TemplateName Template;

DeducedTemplateSpecializationType(TemplateName Template,
                                  QualType DeducedAsType,
                                  bool IsDeducedAsDependent)
    : DeducedType(DeducedTemplateSpecialization, DeducedAsType,
                  toTypeDependence(Template.getDependence()) |
                      (IsDeducedAsDependent
                           ? TypeDependence::DependentInstantiation
                           : TypeDependence::None)),
      Template(Template) {}

5062public:
/// Retrieve the name of the template that we are deducing.
TemplateName getTemplateName() const { return Template;}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getTemplateName(), getDeducedType(), isDependentType());
}

static void Profile(llvm::FoldingSetNodeID &ID, TemplateName Template,
                    QualType Deduced, bool IsDependent) {
  Template.Profile(ID);
  ID.AddPointer(Deduced.getAsOpaquePtr());
  ID.AddBoolean(IsDependent);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == DeducedTemplateSpecialization;
}
5080};

5082/// Represents a type template specialization; the template
5083/// must be a class template, a type alias template, or a template
5084/// template parameter.  A template which cannot be resolved to one of
5085/// these, e.g. because it is written with a dependent scope
5086/// specifier, is instead represented as a
5087/// @c DependentTemplateSpecializationType.
5088///
5089/// A non-dependent template specialization type is always "sugar",
5090/// typically for a \c RecordType.  For example, a class template
5091/// specialization type of \c vector<int> will refer to a tag type for
5092/// the instantiation \c std::vector<int, std::allocator<int>>
5093///
5094/// Template specializations are dependent if either the template or
5095/// any of the template arguments are dependent, in which case the
5096/// type may also be canonical.
5097///
5098/// Instances of this type are allocated with a trailing array of
5099/// TemplateArguments, followed by a QualType representing the
5100/// non-canonical aliased type when the template is a type alias
5101/// template.
5102class alignas(8) TemplateSpecializationType
  : public Type,
    public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The name of the template being specialized.  This is
/// either a TemplateName::Template (in which case it is a
/// ClassTemplateDecl*, a TemplateTemplateParmDecl*, or a
/// TypeAliasTemplateDecl*), a
/// TemplateName::SubstTemplateTemplateParmPack, or a
/// TemplateName::SubstTemplateTemplateParm (in which case the
/// replacement must, recursively, be one of these).
TemplateName Template;

TemplateSpecializationType(TemplateName T,
                           ArrayRef<TemplateArgument> Args,
                           QualType Canon,
                           QualType Aliased);

5121public:
/// Determine whether any of the given template arguments are dependent.
///
/// The converted arguments should be supplied when known; whether an
/// argument is dependent can depend on the conversions performed on it
/// (for example, a 'const int' passed as a template argument might be
/// dependent if the parameter is a reference but non-dependent if the
/// parameter is an int).
///
/// Note that the \p Args parameter is unused: this is intentional, to remind
/// the caller that they need to pass in the converted arguments, not the
/// specified arguments.
static bool
anyDependentTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,
                              ArrayRef<TemplateArgument> Converted);
static bool
anyDependentTemplateArguments(const TemplateArgumentListInfo &,
                              ArrayRef<TemplateArgument> Converted);
static bool anyInstantiationDependentTemplateArguments(
    ArrayRef<TemplateArgumentLoc> Args);

/// True if this template specialization type matches a current
/// instantiation in the context in which it is found.
bool isCurrentInstantiation() const {
  return isa<InjectedClassNameType>(getCanonicalTypeInternal());
}

/// Determine if this template specialization type is for a type alias
/// template that has been substituted.
///
/// Nearly every template specialization type whose template is an alias
/// template will be substituted. However, this is not the case when
/// the specialization contains a pack expansion but the template alias
/// does not have a corresponding parameter pack, e.g.,
///
/// \code
/// template<typename T, typename U, typename V> struct S;
/// template<typename T, typename U> using A = S<T, int, U>;
/// template<typename... Ts> struct X {
///   typedef A<Ts...> type; // not a type alias
/// };
/// \endcode
bool isTypeAlias() const { return TemplateSpecializationTypeBits.TypeAlias; }

/// Get the aliased type, if this is a specialization of a type alias
/// template.
QualType getAliasedType() const {
  assert(isTypeAlias() && "not a type alias template specialization")(static_cast<void> (0));
  return *reinterpret_cast<const QualType*>(end());
}

using iterator = const TemplateArgument *;

iterator begin() const { return getArgs(); }
iterator end() const; // defined inline in TemplateBase.h

/// Retrieve the name of the template that we are specializing.
TemplateName getTemplateName() const { return Template; }

/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return reinterpret_cast<const TemplateArgument *>(this + 1);
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return TemplateSpecializationTypeBits.NumArgs;
}

/// Retrieve a specific template argument as a type.
/// \pre \c isArgType(Arg)
const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> template_arguments() const {
  return {getArgs(), getNumArgs()};
}

bool isSugared() const {
  return !isDependentType() || isCurrentInstantiation() || isTypeAlias();
}

QualType desugar() const {
  return isTypeAlias() ? getAliasedType() : getCanonicalTypeInternal();
}

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx) {
  Profile(ID, Template, template_arguments(), Ctx);
  if (isTypeAlias())
    getAliasedType().Profile(ID);
}

static void Profile(llvm::FoldingSetNodeID &ID, TemplateName T,
                    ArrayRef<TemplateArgument> Args,
                    const ASTContext &Context);

static bool classof(const Type *T) {
  return T->getTypeClass() == TemplateSpecialization;
}
5219};

5221/// Print a template argument list, including the '<' and '>'
5222/// enclosing the template arguments.
5223void printTemplateArgumentList(raw_ostream &OS,
                             ArrayRef<TemplateArgument> Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5228void printTemplateArgumentList(raw_ostream &OS,
                             ArrayRef<TemplateArgumentLoc> Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5233void printTemplateArgumentList(raw_ostream &OS,
                             const TemplateArgumentListInfo &Args,
                             const PrintingPolicy &Policy,
                             const TemplateParameterList *TPL = nullptr);

5238/// The injected class name of a C++ class template or class
5239/// template partial specialization.  Used to record that a type was
5240/// spelled with a bare identifier rather than as a template-id; the
5241/// equivalent for non-templated classes is just RecordType.
5242///
5243/// Injected class name types are always dependent.  Template
5244/// instantiation turns these into RecordTypes.
5245///
5246/// Injected class name types are always canonical.  This works
5247/// because it is impossible to compare an injected class name type
5248/// with the corresponding non-injected template type, for the same
5249/// reason that it is impossible to directly compare template
5250/// parameters from different dependent contexts: injected class name
5251/// types can only occur within the scope of a particular templated
5252/// declaration, and within that scope every template specialization
5253/// will canonicalize to the injected class name (when appropriate
5254/// according to the rules of the language).
5255class InjectedClassNameType : public Type {
friend class ASTContext; // ASTContext creates these.
friend class ASTNodeImporter;
friend class ASTReader; // FIXME: ASTContext::getInjectedClassNameType is not
                        // currently suitable for AST reading, too much
                        // interdependencies.
template <class T> friend class serialization::AbstractTypeReader;

CXXRecordDecl *Decl;

/// The template specialization which this type represents.
/// For example, in
///   template <class T> class A { ... };
/// this is A<T>, whereas in
///   template <class X, class Y> class A<B<X,Y> > { ... };
/// this is A<B<X,Y> >.
///
/// It is always unqualified, always a template specialization type,
/// and always dependent.
QualType InjectedType;

InjectedClassNameType(CXXRecordDecl *D, QualType TST)
    : Type(InjectedClassName, QualType(),
           TypeDependence::DependentInstantiation),
      Decl(D), InjectedType(TST) {
  assert(isa<TemplateSpecializationType>(TST))(static_cast<void> (0));
  assert(!TST.hasQualifiers())(static_cast<void> (0));
  assert(TST->isDependentType())(static_cast<void> (0));
}

5285public:
QualType getInjectedSpecializationType() const { return InjectedType; }

const TemplateSpecializationType *getInjectedTST() const {
  return cast<TemplateSpecializationType>(InjectedType.getTypePtr());
}

TemplateName getTemplateName() const {
  return getInjectedTST()->getTemplateName();
}

CXXRecordDecl *getDecl() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == InjectedClassName;
}
5304};

5306/// The kind of a tag type.
5307enum TagTypeKind {
/// The "struct" keyword.
TTK_Struct,

/// The "__interface" keyword.
TTK_Interface,

/// The "union" keyword.
TTK_Union,

/// The "class" keyword.
TTK_Class,

/// The "enum" keyword.
TTK_Enum
5322};

5324/// The elaboration keyword that precedes a qualified type name or
5325/// introduces an elaborated-type-specifier.
5326enum ElaboratedTypeKeyword {
/// The "struct" keyword introduces the elaborated-type-specifier.
ETK_Struct,

/// The "__interface" keyword introduces the elaborated-type-specifier.
ETK_Interface,

/// The "union" keyword introduces the elaborated-type-specifier.
ETK_Union,

/// The "class" keyword introduces the elaborated-type-specifier.
ETK_Class,

/// The "enum" keyword introduces the elaborated-type-specifier.
ETK_Enum,

/// The "typename" keyword precedes the qualified type name, e.g.,
/// \c typename T::type.
ETK_Typename,

/// No keyword precedes the qualified type name.
ETK_None
5348};

5350/// A helper class for Type nodes having an ElaboratedTypeKeyword.
5351/// The keyword in stored in the free bits of the base class.
5352/// Also provides a few static helpers for converting and printing
5353/// elaborated type keyword and tag type kind enumerations.
5354class TypeWithKeyword : public Type {
5355protected:
TypeWithKeyword(ElaboratedTypeKeyword Keyword, TypeClass tc,
                QualType Canonical, TypeDependence Dependence)
    : Type(tc, Canonical, Dependence) {
  TypeWithKeywordBits.Keyword = Keyword;
}

5362public:
ElaboratedTypeKeyword getKeyword() const {
  return static_cast<ElaboratedTypeKeyword>(TypeWithKeywordBits.Keyword);
}

/// Converts a type specifier (DeclSpec::TST) into an elaborated type keyword.
static ElaboratedTypeKeyword getKeywordForTypeSpec(unsigned TypeSpec);

/// Converts a type specifier (DeclSpec::TST) into a tag type kind.
/// It is an error to provide a type specifier which *isn't* a tag kind here.
static TagTypeKind getTagTypeKindForTypeSpec(unsigned TypeSpec);

/// Converts a TagTypeKind into an elaborated type keyword.
static ElaboratedTypeKeyword getKeywordForTagTypeKind(TagTypeKind Tag);

/// Converts an elaborated type keyword into a TagTypeKind.
/// It is an error to provide an elaborated type keyword
/// which *isn't* a tag kind here.
static TagTypeKind getTagTypeKindForKeyword(ElaboratedTypeKeyword Keyword);

static bool KeywordIsTagTypeKind(ElaboratedTypeKeyword Keyword);

static StringRef getKeywordName(ElaboratedTypeKeyword Keyword);

static StringRef getTagTypeKindName(TagTypeKind Kind) {
  return getKeywordName(getKeywordForTagTypeKind(Kind));
}

class CannotCastToThisType {};
static CannotCastToThisType classof(const Type *);
5392};

5394/// Represents a type that was referred to using an elaborated type
5395/// keyword, e.g., struct S, or via a qualified name, e.g., N::M::type,
5396/// or both.
5397///
5398/// This type is used to keep track of a type name as written in the
5399/// source code, including tag keywords and any nested-name-specifiers.
5400/// The type itself is always "sugar", used to express what was written
5401/// in the source code but containing no additional semantic information.
5402class ElaboratedType final
  : public TypeWithKeyword,
    public llvm::FoldingSetNode,
    private llvm::TrailingObjects<ElaboratedType, TagDecl *> {
friend class ASTContext; // ASTContext creates these
friend TrailingObjects;

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The type that this qualified name refers to.
QualType NamedType;

/// The (re)declaration of this tag type owned by this occurrence is stored
/// as a trailing object if there is one. Use getOwnedTagDecl to obtain
/// it, or obtain a null pointer if there is none.

ElaboratedType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
               QualType NamedType, QualType CanonType, TagDecl *OwnedTagDecl)
    : TypeWithKeyword(Keyword, Elaborated, CanonType,
                      // Any semantic dependence on the qualifier will have
                      // been incorporated into NamedType. We still need to
                      // track syntactic (instantiation / error / pack)
                      // dependence on the qualifier.
                      NamedType->getDependence() |
                          (NNS ? toSyntacticDependence(
                                     toTypeDependence(NNS->getDependence()))
                               : TypeDependence::None)),
      NNS(NNS), NamedType(NamedType) {
  ElaboratedTypeBits.HasOwnedTagDecl = false;
  if (OwnedTagDecl) {
    ElaboratedTypeBits.HasOwnedTagDecl = true;
    *getTrailingObjects<TagDecl *>() = OwnedTagDecl;
  }
  assert(!(Keyword == ETK_None && NNS == nullptr) &&(static_cast<void> (0))
         "ElaboratedType cannot have elaborated type keyword "(static_cast<void> (0))
         "and name qualifier both null.")(static_cast<void> (0));
}

5441public:
/// Retrieve the qualification on this type.
NestedNameSpecifier *getQualifier() const { return NNS; }

/// Retrieve the type named by the qualified-id.
QualType getNamedType() const { return NamedType; }

/// Remove a single level of sugar.
QualType desugar() const { return getNamedType(); }

/// Returns whether this type directly provides sugar.
bool isSugared() const { return true; }

/// Return the (re)declaration of this type owned by this occurrence of this
/// type, or nullptr if there is none.
TagDecl *getOwnedTagDecl() const {
  return ElaboratedTypeBits.HasOwnedTagDecl ? *getTrailingObjects<TagDecl *>()
                                            : nullptr;
}

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getKeyword(), NNS, NamedType, getOwnedTagDecl());
}

static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *NNS, QualType NamedType,
                    TagDecl *OwnedTagDecl) {
  ID.AddInteger(Keyword);
  ID.AddPointer(NNS);
  NamedType.Profile(ID);
  ID.AddPointer(OwnedTagDecl);
}

static bool classof(const Type *T) { return T->getTypeClass() == Elaborated; }
5475};

5477/// Represents a qualified type name for which the type name is
5478/// dependent.
5479///
5480/// DependentNameType represents a class of dependent types that involve a
5481/// possibly dependent nested-name-specifier (e.g., "T::") followed by a
5482/// name of a type. The DependentNameType may start with a "typename" (for a
5483/// typename-specifier), "class", "struct", "union", or "enum" (for a
5484/// dependent elaborated-type-specifier), or nothing (in contexts where we
5485/// know that we must be referring to a type, e.g., in a base class specifier).
5486/// Typically the nested-name-specifier is dependent, but in MSVC compatibility
5487/// mode, this type is used with non-dependent names to delay name lookup until
5488/// instantiation.
5489class DependentNameType : public TypeWithKeyword, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The type that this typename specifier refers to.
const IdentifierInfo *Name;

DependentNameType(ElaboratedTypeKeyword Keyword, NestedNameSpecifier *NNS,
                  const IdentifierInfo *Name, QualType CanonType)
    : TypeWithKeyword(Keyword, DependentName, CanonType,
                      TypeDependence::DependentInstantiation |
                          toTypeDependence(NNS->getDependence())),
      NNS(NNS), Name(Name) {}

5505public:
/// Retrieve the qualification on this type.
NestedNameSpecifier *getQualifier() const { return NNS; }

/// Retrieve the type named by the typename specifier as an identifier.
///
/// This routine will return a non-NULL identifier pointer when the
/// form of the original typename was terminated by an identifier,
/// e.g., "typename T::type".
const IdentifierInfo *getIdentifier() const {
  return Name;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getKeyword(), NNS, Name);
}

static void Profile(llvm::FoldingSetNodeID &ID, ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *NNS, const IdentifierInfo *Name) {
  ID.AddInteger(Keyword);
  ID.AddPointer(NNS);
  ID.AddPointer(Name);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentName;
}
5535};

5537/// Represents a template specialization type whose template cannot be
5538/// resolved, e.g.
5539///   A<T>::template B<T>
5540class alignas(8) DependentTemplateSpecializationType
  : public TypeWithKeyword,
    public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The nested name specifier containing the qualifier.
NestedNameSpecifier *NNS;

/// The identifier of the template.
const IdentifierInfo *Name;

DependentTemplateSpecializationType(ElaboratedTypeKeyword Keyword,
                                    NestedNameSpecifier *NNS,
                                    const IdentifierInfo *Name,
                                    ArrayRef<TemplateArgument> Args,
                                    QualType Canon);

const TemplateArgument *getArgBuffer() const {
  return reinterpret_cast<const TemplateArgument*>(this+1);
}

TemplateArgument *getArgBuffer() {
  return reinterpret_cast<TemplateArgument*>(this+1);
}

5565public:
NestedNameSpecifier *getQualifier() const { return NNS; }
const IdentifierInfo *getIdentifier() const { return Name; }

/// Retrieve the template arguments.
const TemplateArgument *getArgs() const {
  return getArgBuffer();
}

/// Retrieve the number of template arguments.
unsigned getNumArgs() const {
  return DependentTemplateSpecializationTypeBits.NumArgs;
}

const TemplateArgument &getArg(unsigned Idx) const; // in TemplateBase.h

ArrayRef<TemplateArgument> template_arguments() const {
  return {getArgs(), getNumArgs()};
}

using iterator = const TemplateArgument *;

iterator begin() const { return getArgs(); }
iterator end() const; // inline in TemplateBase.h

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
  Profile(ID, Context, getKeyword(), NNS, Name, {getArgs(), getNumArgs()});
}

static void Profile(llvm::FoldingSetNodeID &ID,
                    const ASTContext &Context,
                    ElaboratedTypeKeyword Keyword,
                    NestedNameSpecifier *Qualifier,
                    const IdentifierInfo *Name,
                    ArrayRef<TemplateArgument> Args);

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentTemplateSpecialization;
}
5607};

5609/// Represents a pack expansion of types.
5610///
5611/// Pack expansions are part of C++11 variadic templates. A pack
5612/// expansion contains a pattern, which itself contains one or more
5613/// "unexpanded" parameter packs. When instantiated, a pack expansion
5614/// produces a series of types, each instantiated from the pattern of
5615/// the expansion, where the Ith instantiation of the pattern uses the
5616/// Ith arguments bound to each of the unexpanded parameter packs. The
5617/// pack expansion is considered to "expand" these unexpanded
5618/// parameter packs.
5619///
5620/// \code
5621/// template<typename ...Types> struct tuple;
5622///
5623/// template<typename ...Types>
5624/// struct tuple_of_references {
5625///   typedef tuple<Types&...> type;
5626/// };
5627/// \endcode
5628///
5629/// Here, the pack expansion \c Types&... is represented via a
5630/// PackExpansionType whose pattern is Types&.
5631class PackExpansionType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these

/// The pattern of the pack expansion.
QualType Pattern;

PackExpansionType(QualType Pattern, QualType Canon,
                  Optional<unsigned> NumExpansions)
    : Type(PackExpansion, Canon,
           (Pattern->getDependence() | TypeDependence::Dependent |
            TypeDependence::Instantiation) &
               ~TypeDependence::UnexpandedPack),
      Pattern(Pattern) {
  PackExpansionTypeBits.NumExpansions =
      NumExpansions ? *NumExpansions + 1 : 0;
}

5648public:
/// Retrieve the pattern of this pack expansion, which is the
/// type that will be repeatedly instantiated when instantiating the
/// pack expansion itself.
QualType getPattern() const { return Pattern; }

/// Retrieve the number of expansions that this pack expansion will
/// generate, if known.
Optional<unsigned> getNumExpansions() const {
  if (PackExpansionTypeBits.NumExpansions)
    return PackExpansionTypeBits.NumExpansions - 1;
  return None;
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPattern(), getNumExpansions());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType Pattern,
                    Optional<unsigned> NumExpansions) {
  ID.AddPointer(Pattern.getAsOpaquePtr());
  ID.AddBoolean(NumExpansions.hasValue());
  if (NumExpansions)
    ID.AddInteger(*NumExpansions);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == PackExpansion;
}
5680};

5682/// This class wraps the list of protocol qualifiers. For types that can
5683/// take ObjC protocol qualifers, they can subclass this class.
5684template <class T>
5685class ObjCProtocolQualifiers {
5686protected:
ObjCProtocolQualifiers() = default;

ObjCProtocolDecl * const *getProtocolStorage() const {
  return const_cast<ObjCProtocolQualifiers*>(this)->getProtocolStorage();
}

ObjCProtocolDecl **getProtocolStorage() {
  return static_cast<T*>(this)->getProtocolStorageImpl();
}

void setNumProtocols(unsigned N) {
  static_cast<T*>(this)->setNumProtocolsImpl(N);
}

void initialize(ArrayRef<ObjCProtocolDecl *> protocols) {
  setNumProtocols(protocols.size());
  assert(getNumProtocols() == protocols.size() &&(static_cast<void> (0))
         "bitfield overflow in protocol count")(static_cast<void> (0));
  if (!protocols.empty())
    memcpy(getProtocolStorage(), protocols.data(),
           protocols.size() * sizeof(ObjCProtocolDecl*));
}

5710public:
using qual_iterator = ObjCProtocolDecl * const *;
using qual_range = llvm::iterator_range<qual_iterator>;

qual_range quals() const { return qual_range(qual_begin(), qual_end()); }
qual_iterator qual_begin() const { return getProtocolStorage(); }
qual_iterator qual_end() const { return qual_begin() + getNumProtocols(); }

bool qual_empty() const { return getNumProtocols() == 0; }

/// Return the number of qualifying protocols in this type, or 0 if
/// there are none.
unsigned getNumProtocols() const {
  return static_cast<const T*>(this)->getNumProtocolsImpl();
}

/// Fetch a protocol by index.
ObjCProtocolDecl *getProtocol(unsigned I) const {
  assert(I < getNumProtocols() && "Out-of-range protocol access")(static_cast<void> (0));
  return qual_begin()[I];
}

/// Retrieve all of the protocol qualifiers.
ArrayRef<ObjCProtocolDecl *> getProtocols() const {
  return ArrayRef<ObjCProtocolDecl *>(qual_begin(), getNumProtocols());
}
5736};

5738/// Represents a type parameter type in Objective C. It can take
5739/// a list of protocols.
5740class ObjCTypeParamType : public Type,
                        public ObjCProtocolQualifiers<ObjCTypeParamType>,
                        public llvm::FoldingSetNode {
friend class ASTContext;
friend class ObjCProtocolQualifiers<ObjCTypeParamType>;

/// The number of protocols stored on this type.
unsigned NumProtocols : 6;

ObjCTypeParamDecl *OTPDecl;

/// The protocols are stored after the ObjCTypeParamType node. In the
/// canonical type, the list of protocols are sorted alphabetically
/// and uniqued.
ObjCProtocolDecl **getProtocolStorageImpl();

/// Return the number of qualifying protocols in this interface type,
/// or 0 if there are none.
unsigned getNumProtocolsImpl() const {
  return NumProtocols;
}

void setNumProtocolsImpl(unsigned N) {
  NumProtocols = N;
}

ObjCTypeParamType(const ObjCTypeParamDecl *D,
                  QualType can,
                  ArrayRef<ObjCProtocolDecl *> protocols);

5770public:
bool isSugared() const { return true; }
QualType desugar() const { return getCanonicalTypeInternal(); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCTypeParam;
}

void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    const ObjCTypeParamDecl *OTPDecl,
                    QualType CanonicalType,
                    ArrayRef<ObjCProtocolDecl *> protocols);

ObjCTypeParamDecl *getDecl() const { return OTPDecl; }
5785};

5787/// Represents a class type in Objective C.
5788///
5789/// Every Objective C type is a combination of a base type, a set of
5790/// type arguments (optional, for parameterized classes) and a list of
5791/// protocols.
5792///
5793/// Given the following declarations:
5794/// \code
5795///   \@class C<T>;
5796///   \@protocol P;
5797/// \endcode
5798///
5799/// 'C' is an ObjCInterfaceType C.  It is sugar for an ObjCObjectType
5800/// with base C and no protocols.
5801///
5802/// 'C<P>' is an unspecialized ObjCObjectType with base C and protocol list [P].
5803/// 'C<C*>' is a specialized ObjCObjectType with type arguments 'C*' and no
5804/// protocol list.
5805/// 'C<C*><P>' is a specialized ObjCObjectType with base C, type arguments 'C*',
5806/// and protocol list [P].
5807///
5808/// 'id' is a TypedefType which is sugar for an ObjCObjectPointerType whose
5809/// pointee is an ObjCObjectType with base BuiltinType::ObjCIdType
5810/// and no protocols.
5811///
5812/// 'id<P>' is an ObjCObjectPointerType whose pointee is an ObjCObjectType
5813/// with base BuiltinType::ObjCIdType and protocol list [P].  Eventually
5814/// this should get its own sugar class to better represent the source.
5815class ObjCObjectType : public Type,
                     public ObjCProtocolQualifiers<ObjCObjectType> {
friend class ObjCProtocolQualifiers<ObjCObjectType>;

// ObjCObjectType.NumTypeArgs - the number of type arguments stored
// after the ObjCObjectPointerType node.
// ObjCObjectType.NumProtocols - the number of protocols stored
// after the type arguments of ObjCObjectPointerType node.
//
// These protocols are those written directly on the type.  If
// protocol qualifiers ever become additive, the iterators will need
// to get kindof complicated.
//
// In the canonical object type, these are sorted alphabetically
// and uniqued.

/// Either a BuiltinType or an InterfaceType or sugar for either.
QualType BaseType;

/// Cached superclass type.
mutable llvm::PointerIntPair<const ObjCObjectType *, 1, bool>
  CachedSuperClassType;

QualType *getTypeArgStorage();
const QualType *getTypeArgStorage() const {
  return const_cast<ObjCObjectType *>(this)->getTypeArgStorage();
}

ObjCProtocolDecl **getProtocolStorageImpl();
/// Return the number of qualifying protocols in this interface type,
/// or 0 if there are none.
unsigned getNumProtocolsImpl() const {
  return ObjCObjectTypeBits.NumProtocols;
}
void setNumProtocolsImpl(unsigned N) {
  ObjCObjectTypeBits.NumProtocols = N;
}

5853protected:
enum Nonce_ObjCInterface { Nonce_ObjCInterface };

ObjCObjectType(QualType Canonical, QualType Base,
               ArrayRef<QualType> typeArgs,
               ArrayRef<ObjCProtocolDecl *> protocols,
               bool isKindOf);

ObjCObjectType(enum Nonce_ObjCInterface)
    : Type(ObjCInterface, QualType(), TypeDependence::None),
      BaseType(QualType(this_(), 0)) {
  ObjCObjectTypeBits.NumProtocols = 0;
  ObjCObjectTypeBits.NumTypeArgs = 0;
  ObjCObjectTypeBits.IsKindOf = 0;
}

void computeSuperClassTypeSlow() const;

5871public:
/// Gets the base type of this object type.  This is always (possibly
/// sugar for) one of:
///  - the 'id' builtin type (as opposed to the 'id' type visible to the
///    user, which is a typedef for an ObjCObjectPointerType)
///  - the 'Class' builtin type (same caveat)
///  - an ObjCObjectType (currently always an ObjCInterfaceType)
QualType getBaseType() const { return BaseType; }

bool isObjCId() const {
  return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCId);
}

bool isObjCClass() const {
  return getBaseType()->isSpecificBuiltinType(BuiltinType::ObjCClass);
}

bool isObjCUnqualifiedId() const { return qual_empty() && isObjCId(); }
bool isObjCUnqualifiedClass() const { return qual_empty() && isObjCClass(); }
bool isObjCUnqualifiedIdOrClass() const {
  if (!qual_empty()) return false;
  if (const BuiltinType *T = getBaseType()->getAs<BuiltinType>())
    return T->getKind() == BuiltinType::ObjCId ||
           T->getKind() == BuiltinType::ObjCClass;
  return false;
}
bool isObjCQualifiedId() const { return !qual_empty() && isObjCId(); }
bool isObjCQualifiedClass() const { return !qual_empty() && isObjCClass(); }

/// Gets the interface declaration for this object type, if the base type
/// really is an interface.
ObjCInterfaceDecl *getInterface() const;

/// Determine whether this object type is "specialized", meaning
/// that it has type arguments.
bool isSpecialized() const;

/// Determine whether this object type was written with type arguments.
bool isSpecializedAsWritten() const {
  return ObjCObjectTypeBits.NumTypeArgs > 0;
}

/// Determine whether this object type is "unspecialized", meaning
/// that it has no type arguments.
bool isUnspecialized() const { return !isSpecialized(); }

/// Determine whether this object type is "unspecialized" as
/// written, meaning that it has no type arguments.
bool isUnspecializedAsWritten() const { return !isSpecializedAsWritten(); }

/// Retrieve the type arguments of this object type (semantically).
ArrayRef<QualType> getTypeArgs() const;

/// Retrieve the type arguments of this object type as they were
/// written.
ArrayRef<QualType> getTypeArgsAsWritten() const {
  return llvm::makeArrayRef(getTypeArgStorage(),
                            ObjCObjectTypeBits.NumTypeArgs);
}

/// Whether this is a "__kindof" type as written.
bool isKindOfTypeAsWritten() const { return ObjCObjectTypeBits.IsKindOf; }

/// Whether this ia a "__kindof" type (semantically).
bool isKindOfType() const;

/// Retrieve the type of the superclass of this object type.
///
/// This operation substitutes any type arguments into the
/// superclass of the current class type, potentially producing a
/// specialization of the superclass type. Produces a null type if
/// there is no superclass.
QualType getSuperClassType() const {
  if (!CachedSuperClassType.getInt())
    computeSuperClassTypeSlow();

  assert(CachedSuperClassType.getInt() && "Superclass not set?")(static_cast<void> (0));
  return QualType(CachedSuperClassType.getPointer(), 0);
}

/// Strip off the Objective-C "kindof" type and (with it) any
/// protocol qualifiers.
QualType stripObjCKindOfTypeAndQuals(const ASTContext &ctx) const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCObject ||
         T->getTypeClass() == ObjCInterface;
}
5962};

5964/// A class providing a concrete implementation
5965/// of ObjCObjectType, so as to not increase the footprint of
5966/// ObjCInterfaceType.  Code outside of ASTContext and the core type
5967/// system should not reference this type.
5968class ObjCObjectTypeImpl : public ObjCObjectType, public llvm::FoldingSetNode {
friend class ASTContext;

// If anyone adds fields here, ObjCObjectType::getProtocolStorage()
// will need to be modified.

ObjCObjectTypeImpl(QualType Canonical, QualType Base,
                   ArrayRef<QualType> typeArgs,
                   ArrayRef<ObjCProtocolDecl *> protocols,
                   bool isKindOf)
    : ObjCObjectType(Canonical, Base, typeArgs, protocols, isKindOf) {}

5980public:
void Profile(llvm::FoldingSetNodeID &ID);
static void Profile(llvm::FoldingSetNodeID &ID,
                    QualType Base,
                    ArrayRef<QualType> typeArgs,
                    ArrayRef<ObjCProtocolDecl *> protocols,
                    bool isKindOf);
5987};

5989inline QualType *ObjCObjectType::getTypeArgStorage() {
return reinterpret_cast<QualType *>(static_cast<ObjCObjectTypeImpl*>(this)+1);
5991}

5993inline ObjCProtocolDecl **ObjCObjectType::getProtocolStorageImpl() {
  return reinterpret_cast<ObjCProtocolDecl**>(
           getTypeArgStorage() + ObjCObjectTypeBits.NumTypeArgs);
5996}

5998inline ObjCProtocolDecl **ObjCTypeParamType::getProtocolStorageImpl() {
  return reinterpret_cast<ObjCProtocolDecl**>(
           static_cast<ObjCTypeParamType*>(this)+1);
6001}

6003/// Interfaces are the core concept in Objective-C for object oriented design.
6004/// They basically correspond to C++ classes.  There are two kinds of interface
6005/// types: normal interfaces like `NSString`, and qualified interfaces, which
6006/// are qualified with a protocol list like `NSString<NSCopyable, NSAmazing>`.
6007///
6008/// ObjCInterfaceType guarantees the following properties when considered
6009/// as a subtype of its superclass, ObjCObjectType:
6010///   - There are no protocol qualifiers.  To reinforce this, code which
6011///     tries to invoke the protocol methods via an ObjCInterfaceType will
6012///     fail to compile.
6013///   - It is its own base type.  That is, if T is an ObjCInterfaceType*,
6014///     T->getBaseType() == QualType(T, 0).
6015class ObjCInterfaceType : public ObjCObjectType {
friend class ASTContext; // ASTContext creates these.
friend class ASTReader;
friend class ObjCInterfaceDecl;
template <class T> friend class serialization::AbstractTypeReader;

mutable ObjCInterfaceDecl *Decl;

ObjCInterfaceType(const ObjCInterfaceDecl *D)
    : ObjCObjectType(Nonce_ObjCInterface),
      Decl(const_cast<ObjCInterfaceDecl*>(D)) {}

6027public:
/// Get the declaration of this interface.
ObjCInterfaceDecl *getDecl() const { return Decl; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCInterface;
}

// Nonsense to "hide" certain members of ObjCObjectType within this
// class.  People asking for protocols on an ObjCInterfaceType are
// not going to get what they want: ObjCInterfaceTypes are
// guaranteed to have no protocols.
enum {
  qual_iterator,
  qual_begin,
  qual_end,
  getNumProtocols,
  getProtocol
};
6049};

6051inline ObjCInterfaceDecl *ObjCObjectType::getInterface() const {
QualType baseType = getBaseType();
while (const auto *ObjT = baseType->getAs<ObjCObjectType>()) {
  if (const auto *T = dyn_cast<ObjCInterfaceType>(ObjT))
    return T->getDecl();

  baseType = ObjT->getBaseType();
}

return nullptr;
6061}

6063/// Represents a pointer to an Objective C object.
6064///
6065/// These are constructed from pointer declarators when the pointee type is
6066/// an ObjCObjectType (or sugar for one).  In addition, the 'id' and 'Class'
6067/// types are typedefs for these, and the protocol-qualified types 'id<P>'
6068/// and 'Class<P>' are translated into these.
6069///
6070/// Pointers to pointers to Objective C objects are still PointerTypes;
6071/// only the first level of pointer gets it own type implementation.
6072class ObjCObjectPointerType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType PointeeType;

ObjCObjectPointerType(QualType Canonical, QualType Pointee)
    : Type(ObjCObjectPointer, Canonical, Pointee->getDependence()),
      PointeeType(Pointee) {}

6081public:
/// Gets the type pointed to by this ObjC pointer.
/// The result will always be an ObjCObjectType or sugar thereof.
QualType getPointeeType() const { return PointeeType; }

/// Gets the type pointed to by this ObjC pointer.  Always returns non-null.
///
/// This method is equivalent to getPointeeType() except that
/// it discards any typedefs (or other sugar) between this
/// type and the "outermost" object type.  So for:
/// \code
///   \@class A; \@protocol P; \@protocol Q;
///   typedef A<P> AP;
///   typedef A A1;
///   typedef A1<P> A1P;
///   typedef A1P<Q> A1PQ;
/// \endcode
/// For 'A*', getObjectType() will return 'A'.
/// For 'A<P>*', getObjectType() will return 'A<P>'.
/// For 'AP*', getObjectType() will return 'A<P>'.
/// For 'A1*', getObjectType() will return 'A'.
/// For 'A1<P>*', getObjectType() will return 'A1<P>'.
/// For 'A1P*', getObjectType() will return 'A1<P>'.
/// For 'A1PQ*', getObjectType() will return 'A1<Q>', because
///   adding protocols to a protocol-qualified base discards the
///   old qualifiers (for now).  But if it didn't, getObjectType()
///   would return 'A1P<Q>' (and we'd have to make iterating over
///   qualifiers more complicated).
const ObjCObjectType *getObjectType() const {
  return PointeeType->castAs<ObjCObjectType>();
}

/// If this pointer points to an Objective C
/// \@interface type, gets the type for that interface.  Any protocol
/// qualifiers on the interface are ignored.
///
/// \return null if the base type for this pointer is 'id' or 'Class'
const ObjCInterfaceType *getInterfaceType() const;

/// If this pointer points to an Objective \@interface
/// type, gets the declaration for that interface.
///
/// \return null if the base type for this pointer is 'id' or 'Class'
ObjCInterfaceDecl *getInterfaceDecl() const {
  return getObjectType()->getInterface();
}

/// True if this is equivalent to the 'id' type, i.e. if
/// its object type is the primitive 'id' type with no protocols.
bool isObjCIdType() const {
  return getObjectType()->isObjCUnqualifiedId();
}

/// True if this is equivalent to the 'Class' type,
/// i.e. if its object tive is the primitive 'Class' type with no protocols.
bool isObjCClassType() const {
  return getObjectType()->isObjCUnqualifiedClass();
}

/// True if this is equivalent to the 'id' or 'Class' type,
bool isObjCIdOrClassType() const {
  return getObjectType()->isObjCUnqualifiedIdOrClass();
}

/// True if this is equivalent to 'id<P>' for some non-empty set of
/// protocols.
bool isObjCQualifiedIdType() const {
  return getObjectType()->isObjCQualifiedId();
}

/// True if this is equivalent to 'Class<P>' for some non-empty set of
/// protocols.
bool isObjCQualifiedClassType() const {
  return getObjectType()->isObjCQualifiedClass();
}

/// Whether this is a "__kindof" type.
bool isKindOfType() const { return getObjectType()->isKindOfType(); }

/// Whether this type is specialized, meaning that it has type arguments.
bool isSpecialized() const { return getObjectType()->isSpecialized(); }

/// Whether this type is specialized, meaning that it has type arguments.
bool isSpecializedAsWritten() const {
  return getObjectType()->isSpecializedAsWritten();
}

/// Whether this type is unspecialized, meaning that is has no type arguments.
bool isUnspecialized() const { return getObjectType()->isUnspecialized(); }

/// Determine whether this object type is "unspecialized" as
/// written, meaning that it has no type arguments.
bool isUnspecializedAsWritten() const { return !isSpecializedAsWritten(); }

/// Retrieve the type arguments for this type.
ArrayRef<QualType> getTypeArgs() const {
  return getObjectType()->getTypeArgs();
}

/// Retrieve the type arguments for this type.
ArrayRef<QualType> getTypeArgsAsWritten() const {
  return getObjectType()->getTypeArgsAsWritten();
}

/// An iterator over the qualifiers on the object type.  Provided
/// for convenience.  This will always iterate over the full set of
/// protocols on a type, not just those provided directly.
using qual_iterator = ObjCObjectType::qual_iterator;
using qual_range = llvm::iterator_range<qual_iterator>;

qual_range quals() const { return qual_range(qual_begin(), qual_end()); }

qual_iterator qual_begin() const {
  return getObjectType()->qual_begin();
}

qual_iterator qual_end() const {
  return getObjectType()->qual_end();
}

bool qual_empty() const { return getObjectType()->qual_empty(); }

/// Return the number of qualifying protocols on the object type.
unsigned getNumProtocols() const {
  return getObjectType()->getNumProtocols();
}

/// Retrieve a qualifying protocol by index on the object type.
ObjCProtocolDecl *getProtocol(unsigned I) const {
  return getObjectType()->getProtocol(I);
}

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

/// Retrieve the type of the superclass of this object pointer type.
///
/// This operation substitutes any type arguments into the
/// superclass of the current class type, potentially producing a
/// pointer to a specialization of the superclass type. Produces a
/// null type if there is no superclass.
QualType getSuperClassType() const;

/// Strip off the Objective-C "kindof" type and (with it) any
/// protocol qualifiers.
const ObjCObjectPointerType *stripObjCKindOfTypeAndQuals(
                               const ASTContext &ctx) const;

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getPointeeType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
  ID.AddPointer(T.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == ObjCObjectPointer;
}
6240};

6242class AtomicType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ValueType;

AtomicType(QualType ValTy, QualType Canonical)
    : Type(Atomic, Canonical, ValTy->getDependence()), ValueType(ValTy) {}

6250public:
/// Gets the type contained by this atomic type, i.e.
/// the type returned by performing an atomic load of this atomic type.
QualType getValueType() const { return ValueType; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getValueType());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T) {
  ID.AddPointer(T.getAsOpaquePtr());
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Atomic;
}
6269};

6271/// PipeType - OpenCL20.
6272class PipeType : public Type, public llvm::FoldingSetNode {
friend class ASTContext; // ASTContext creates these.

QualType ElementType;
bool isRead;

PipeType(QualType elemType, QualType CanonicalPtr, bool isRead)
    : Type(Pipe, CanonicalPtr, elemType->getDependence()),
      ElementType(elemType), isRead(isRead) {}

6282public:
QualType getElementType() const { return ElementType; }

bool isSugared() const { return false; }

QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, getElementType(), isReadOnly());
}

static void Profile(llvm::FoldingSetNodeID &ID, QualType T, bool isRead) {
  ID.AddPointer(T.getAsOpaquePtr());
  ID.AddBoolean(isRead);
}

static bool classof(const Type *T) {
  return T->getTypeClass() == Pipe;
}

bool isReadOnly() const { return isRead; }
6303};

6305/// A fixed int type of a specified bitwidth.
6306class ExtIntType final : public Type, public llvm::FoldingSetNode {
friend class ASTContext;
unsigned IsUnsigned : 1;
unsigned NumBits : 24;

6311protected:
ExtIntType(bool isUnsigned, unsigned NumBits);

6314public:
bool isUnsigned() const { return IsUnsigned; }
bool isSigned() const { return !IsUnsigned; }
unsigned getNumBits() const { return NumBits; }

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, isUnsigned(), getNumBits());
}

static void Profile(llvm::FoldingSetNodeID &ID, bool IsUnsigned,
                    unsigned NumBits) {
  ID.AddBoolean(IsUnsigned);
  ID.AddInteger(NumBits);
}

static bool classof(const Type *T) { return T->getTypeClass() == ExtInt; }
6333};

6335class DependentExtIntType final : public Type, public llvm::FoldingSetNode {
friend class ASTContext;
const ASTContext &Context;
llvm::PointerIntPair<Expr*, 1, bool> ExprAndUnsigned;

6340protected:
DependentExtIntType(const ASTContext &Context, bool IsUnsigned,
                    Expr *NumBits);

6344public:
bool isUnsigned() const;
bool isSigned() const { return !isUnsigned(); }
Expr *getNumBitsExpr() const;

bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }

void Profile(llvm::FoldingSetNodeID &ID) {
  Profile(ID, Context, isUnsigned(), getNumBitsExpr());
}
static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context,
                    bool IsUnsigned, Expr *NumBitsExpr);

static bool classof(const Type *T) {
  return T->getTypeClass() == DependentExtInt;
}
6361};

6363/// A qualifier set is used to build a set of qualifiers.
6364class QualifierCollector : public Qualifiers {
6365public:
QualifierCollector(Qualifiers Qs = Qualifiers()) : Qualifiers(Qs) {}

/// Collect any qualifiers on the given type and return an
/// unqualified type.  The qualifiers are assumed to be consistent
/// with those already in the type.
const Type *strip(QualType type) {
  addFastQualifiers(type.getLocalFastQualifiers());
  if (!type.hasLocalNonFastQualifiers())
    return type.getTypePtrUnsafe();

  const ExtQuals *extQuals = type.getExtQualsUnsafe();
  addConsistentQualifiers(extQuals->getQualifiers());
  return extQuals->getBaseType();
}

/// Apply the collected qualifiers to the given type.
QualType apply(const ASTContext &Context, QualType QT) const;

/// Apply the collected qualifiers to the given type.
QualType apply(const ASTContext &Context, const Type* T) const;
6386};

6388/// A container of type source information.
6389///
6390/// A client can read the relevant info using TypeLoc wrappers, e.g:
6391/// @code
6392/// TypeLoc TL = TypeSourceInfo->getTypeLoc();
6393/// TL.getBeginLoc().print(OS, SrcMgr);
6394/// @endcode
6395class alignas(8) TypeSourceInfo {
// Contains a memory block after the class, used for type source information,
// allocated by ASTContext.
friend class ASTContext;

QualType Ty;

TypeSourceInfo(QualType ty) : Ty(ty) {}

6404public:
/// Return the type wrapped by this type source info.
QualType getType() const { return Ty; }

/// Return the TypeLoc wrapper for the type source info.
TypeLoc getTypeLoc() const; // implemented in TypeLoc.h

/// Override the type stored in this TypeSourceInfo. Use with caution!
void overrideType(QualType T) { Ty = T; }
6413};

6415// Inline function definitions.

6417inline SplitQualType SplitQualType::getSingleStepDesugaredType() const {
SplitQualType desugar =
  Ty->getLocallyUnqualifiedSingleStepDesugaredType().split();
desugar.Quals.addConsistentQualifiers(Quals);
return desugar;
6422}

6424inline const Type *QualType::getTypePtr() const {
return getCommonPtr()->BaseType;
6426}

6428inline const Type *QualType::getTypePtrOrNull() const {
return (isNull() ? nullptr : getCommonPtr()->BaseType);
6430}

6432inline SplitQualType QualType::split() const {
if (!hasLocalNonFastQualifiers())
  return SplitQualType(getTypePtrUnsafe(),
                       Qualifiers::fromFastMask(getLocalFastQualifiers()));

const ExtQuals *eq = getExtQualsUnsafe();
Qualifiers qs = eq->getQualifiers();
qs.addFastQualifiers(getLocalFastQualifiers());
return SplitQualType(eq->getBaseType(), qs);
6441}

6443inline Qualifiers QualType::getLocalQualifiers() const {
Qualifiers Quals;
if (hasLocalNonFastQualifiers())
  Quals = getExtQualsUnsafe()->getQualifiers();
Quals.addFastQualifiers(getLocalFastQualifiers());
return Quals;
6449}

6451inline Qualifiers QualType::getQualifiers() const {
Qualifiers quals = getCommonPtr()->CanonicalType.getLocalQualifiers();
quals.addFastQualifiers(getLocalFastQualifiers());
return quals;
6455}

6457inline unsigned QualType::getCVRQualifiers() const {
unsigned cvr = getCommonPtr()->CanonicalType.getLocalCVRQualifiers();
cvr |= getLocalCVRQualifiers();
return cvr;
6461}

6463inline QualType QualType::getCanonicalType() const {
QualType canon = getCommonPtr()->CanonicalType;
return canon.withFastQualifiers(getLocalFastQualifiers());
6466}

6468inline bool QualType::isCanonical() const {
return getTypePtr()->isCanonicalUnqualified();
6470}

6472inline bool QualType::isCanonicalAsParam() const {
if (!isCanonical()) return false;
if (hasLocalQualifiers()) return false;

const Type *T = getTypePtr();
if (T->isVariablyModifiedType() && T->hasSizedVLAType())
  return false;

return !isa<FunctionType>(T) && !isa<ArrayType>(T);
6481}

6483inline bool QualType::isConstQualified() const {
return isLocalConstQualified() ||
       getCommonPtr()->CanonicalType.isLocalConstQualified();
6486}

6488inline bool QualType::isRestrictQualified() const {
return isLocalRestrictQualified() ||
       getCommonPtr()->CanonicalType.isLocalRestrictQualified();
6491}


6494inline bool QualType::isVolatileQualified() const {
return isLocalVolatileQualified() ||
       getCommonPtr()->CanonicalType.isLocalVolatileQualified();
6497}

6499inline bool QualType::hasQualifiers() const {
return hasLocalQualifiers() ||
       getCommonPtr()->CanonicalType.hasLocalQualifiers();
6502}

6504inline QualType QualType::getUnqualifiedType() const {
if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
  return QualType(getTypePtr(), 0);

return QualType(getSplitUnqualifiedTypeImpl(*this).Ty, 0);
6509}

6511inline SplitQualType QualType::getSplitUnqualifiedType() const {
if (!getTypePtr()->getCanonicalTypeInternal().hasLocalQualifiers())
  return split();

return getSplitUnqualifiedTypeImpl(*this);
6516}

6518inline void QualType::removeLocalConst() {
removeLocalFastQualifiers(Qualifiers::Const);
6520}

6522inline void QualType::removeLocalRestrict() {
removeLocalFastQualifiers(Qualifiers::Restrict);
6524}

6526inline void QualType::removeLocalVolatile() {
removeLocalFastQualifiers(Qualifiers::Volatile);
6528}

6530inline void QualType::removeLocalCVRQualifiers(unsigned Mask) {
assert(!(Mask & ~Qualifiers::CVRMask) && "mask has non-CVR bits")(static_cast<void> (0));
static_assert((int)Qualifiers::CVRMask == (int)Qualifiers::FastMask,
              "Fast bits differ from CVR bits!");

// Fast path: we don't need to touch the slow qualifiers.
removeLocalFastQualifiers(Mask);
6537}

6539/// Check if this type has any address space qualifier.
6540inline bool QualType::hasAddressSpace() const {
return getQualifiers().hasAddressSpace();
6542}

6544/// Return the address space of this type.
6545inline LangAS QualType::getAddressSpace() const {
return getQualifiers().getAddressSpace();
6547}

6549/// Return the gc attribute of this type.
6550inline Qualifiers::GC QualType::getObjCGCAttr() const {
return getQualifiers().getObjCGCAttr();
6552}

6554inline bool QualType::hasNonTrivialToPrimitiveDefaultInitializeCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveDefaultInitializeCUnion(RD);
return false;
6558}

6560inline bool QualType::hasNonTrivialToPrimitiveDestructCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveDestructCUnion(RD);
return false;
6564}

6566inline bool QualType::hasNonTrivialToPrimitiveCopyCUnion() const {
if (auto *RD = getTypePtr()->getBaseElementTypeUnsafe()->getAsRecordDecl())
  return hasNonTrivialToPrimitiveCopyCUnion(RD);
return false;
6570}

6572inline FunctionType::ExtInfo getFunctionExtInfo(const Type &t) {
if (const auto *PT = t.getAs<PointerType>()) {
  if (const auto *FT = PT->getPointeeType()->getAs<FunctionType>())
    return FT->getExtInfo();
} else if (const auto *FT = t.getAs<FunctionType>())
  return FT->getExtInfo();

return FunctionType::ExtInfo();
6580}

6582inline FunctionType::ExtInfo getFunctionExtInfo(QualType t) {
return getFunctionExtInfo(*t);
6584}

6586/// Determine whether this type is more
6587/// qualified than the Other type. For example, "const volatile int"
6588/// is more qualified than "const int", "volatile int", and
6589/// "int". However, it is not more qualified than "const volatile
6590/// int".
6591inline bool QualType::isMoreQualifiedThan(QualType other) const {
Qualifiers MyQuals = getQualifiers();
Qualifiers OtherQuals = other.getQualifiers();
return (MyQuals != OtherQuals && MyQuals.compatiblyIncludes(OtherQuals));
6595}

6597/// Determine whether this type is at last
6598/// as qualified as the Other type. For example, "const volatile
6599/// int" is at least as qualified as "const int", "volatile int",
6600/// "int", and "const volatile int".
6601inline bool QualType::isAtLeastAsQualifiedAs(QualType other) const {
Qualifiers OtherQuals = other.getQualifiers();

// Ignore __unaligned qualifier if this type is a void.
if (getUnqualifiedType()->isVoidType())
  OtherQuals.removeUnaligned();

return getQualifiers().compatiblyIncludes(OtherQuals);
6609}

6611/// If Type is a reference type (e.g., const
6612/// int&), returns the type that the reference refers to ("const
6613/// int"). Otherwise, returns the type itself. This routine is used
6614/// throughout Sema to implement C++ 5p6:
6615///
6616///   If an expression initially has the type "reference to T" (8.3.2,
6617///   8.5.3), the type is adjusted to "T" prior to any further
6618///   analysis, the expression designates the object or function
6619///   denoted by the reference, and the expression is an lvalue.
6620inline QualType QualType::getNonReferenceType() const {
if (const auto *RefType = (*this)->getAs<ReferenceType>())
  return RefType->getPointeeType();
else
  return *this;
6625}

6627inline bool QualType::isCForbiddenLValueType() const {
return ((getTypePtr()->isVoidType() && !hasQualifiers()) ||
        getTypePtr()->isFunctionType());
6630}

6632/// Tests whether the type is categorized as a fundamental type.
6633///
6634/// \returns True for types specified in C++0x [basic.fundamental].
6635inline bool Type::isFundamentalType() const {
return isVoidType() ||
       isNullPtrType() ||
       // FIXME: It's really annoying that we don't have an
       // 'isArithmeticType()' which agrees with the standard definition.
       (isArithmeticType() && !isEnumeralType());
6641}

6643/// Tests whether the type is categorized as a compound type.
6644///
6645/// \returns True for types specified in C++0x [basic.compound].
6646inline bool Type::isCompoundType() const {
// C++0x [basic.compound]p1:
//   Compound types can be constructed in the following ways:
//    -- arrays of objects of a given type [...];
return isArrayType() ||
//    -- functions, which have parameters of given types [...];
       isFunctionType() ||
//    -- pointers to void or objects or functions [...];
       isPointerType() ||
//    -- references to objects or functions of a given type. [...]
       isReferenceType() ||
//    -- classes containing a sequence of objects of various types, [...];
       isRecordType() ||
//    -- unions, which are classes capable of containing objects of different
//               types at different times;
       isUnionType() ||
//    -- enumerations, which comprise a set of named constant values. [...];
       isEnumeralType() ||
//    -- pointers to non-static class members, [...].
       isMemberPointerType();
6666}

6668inline bool Type::isFunctionType() const {
return isa<FunctionType>(CanonicalType);
6670}

6672inline bool Type::isPointerType() const {
return isa<PointerType>(CanonicalType);
6674}

6676inline bool Type::isAnyPointerType() const {
return isPointerType() || isObjCObjectPointerType();
6678}

6680inline bool Type::isBlockPointerType() const {
return isa<BlockPointerType>(CanonicalType);
6682}

6684inline bool Type::isReferenceType() const {
return isa<ReferenceType>(CanonicalType);
6686}

6688inline bool Type::isLValueReferenceType() const {
return isa<LValueReferenceType>(CanonicalType);
6690}

6692inline bool Type::isRValueReferenceType() const {
return isa<RValueReferenceType>(CanonicalType);
6694}

6696inline bool Type::isObjectPointerType() const {
// Note: an "object pointer type" is not the same thing as a pointer to an
// object type; rather, it is a pointer to an object type or a pointer to cv
// void.
if (const auto *T = getAs<PointerType>())
  return !T->getPointeeType()->isFunctionType();
else
  return false;
6704}

6706inline bool Type::isFunctionPointerType() const {
if (const auto *T = getAs<PointerType>())
  return T->getPointeeType()->isFunctionType();
else
  return false;
6711}

6713inline bool Type::isFunctionReferenceType() const {
if (const auto *T = getAs<ReferenceType>())
  return T->getPointeeType()->isFunctionType();
else
  return false;
6718}

6720inline bool Type::isMemberPointerType() const {
return isa<MemberPointerType>(CanonicalType);
6722}

6724inline bool Type::isMemberFunctionPointerType() const {
if (const auto *T = getAs<MemberPointerType>())
  return T->isMemberFunctionPointer();
else
  return false;
6729}

6731inline bool Type::isMemberDataPointerType() const {
if (const auto *T = getAs<MemberPointerType>())
  return T->isMemberDataPointer();
else
  return false;
6736}

6738inline bool Type::isArrayType() const {
return isa<ArrayType>(CanonicalType);
6740}

6742inline bool Type::isConstantArrayType() const {
return isa<ConstantArrayType>(CanonicalType);
6744}

6746inline bool Type::isIncompleteArrayType() const {
return isa<IncompleteArrayType>(CanonicalType);
6748}

6750inline bool Type::isVariableArrayType() const {
return isa<VariableArrayType>(CanonicalType);
6752}

6754inline bool Type::isDependentSizedArrayType() const {
return isa<DependentSizedArrayType>(CanonicalType);
6756}

6758inline bool Type::isBuiltinType() const {
return isa<BuiltinType>(CanonicalType);
6760}

6762inline bool Type::isRecordType() const {
return isa<RecordType>(CanonicalType);
6764}

6766inline bool Type::isEnumeralType() const {
return isa<EnumType>(CanonicalType);
6768}

6770inline bool Type::isAnyComplexType() const {
return isa<ComplexType>(CanonicalType);
6772}

6774inline bool Type::isVectorType() const {
return isa<VectorType>(CanonicalType);
6776}

6778inline bool Type::isExtVectorType() const {
return isa<ExtVectorType>(CanonicalType);
6780}

6782inline bool Type::isMatrixType() const {
return isa<MatrixType>(CanonicalType);
6784}

6786inline bool Type::isConstantMatrixType() const {
return isa<ConstantMatrixType>(CanonicalType);
6788}

6790inline bool Type::isDependentAddressSpaceType() const {
return isa<DependentAddressSpaceType>(CanonicalType);
6792}

6794inline bool Type::isObjCObjectPointerType() const {
return isa<ObjCObjectPointerType>(CanonicalType);
6796}

6798inline bool Type::isObjCObjectType() const {
return isa<ObjCObjectType>(CanonicalType);
6800}

6802inline bool Type::isObjCObjectOrInterfaceType() const {
return isa<ObjCInterfaceType>(CanonicalType) ||
  isa<ObjCObjectType>(CanonicalType);
6805}

6807inline bool Type::isAtomicType() const {
return isa<AtomicType>(CanonicalType);
6809}

6811inline bool Type::isUndeducedAutoType() const {
return isa<AutoType>(CanonicalType);
6813}

6815inline bool Type::isObjCQualifiedIdType() const {
if (const auto *OPT10.1
'OPT' is null
1
'OPT' is null
 = getAs<ObjCObjectPointerType>())
10
←
Assuming the object is not a 'ObjCObjectPointerType'→
11
←
Taking false branch→
  return OPT->isObjCQualifiedIdType();
return false;
12
←
Returning zero, which participates in a condition later→
6819}

6821inline bool Type::isObjCQualifiedClassType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCQualifiedClassType();
return false;
6825}

6827inline bool Type::isObjCIdType() const {
if (const auto *OPT5.1
'OPT' is null
1
'OPT' is null
 = getAs<ObjCObjectPointerType>())
5
←
Assuming the object is not a 'ObjCObjectPointerType'→
6
←
Taking false branch→
  return OPT->isObjCIdType();
return false;
7
←
Returning zero, which participates in a condition later→
6831}

6833inline bool Type::isObjCClassType() const {
if (const auto *OPT = getAs<ObjCObjectPointerType>())
  return OPT->isObjCClassType();
return false;
6837}

6839inline bool Type::isObjCSelType() const {
if (const auto *OPT = getAs<PointerType>())
  return OPT->getPointeeType()->isSpecificBuiltinType(BuiltinType::ObjCSel);
return false;
6843}

6845inline bool Type::isObjCBuiltinType() const {
return isObjCIdType() || isObjCClassType() || isObjCSelType();
6847}

6849inline bool Type::isDecltypeType() const {
return isa<DecltypeType>(this);
6851}

6853#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
inline bool Type::is##Id##Type() const { \
  return isSpecificBuiltinType(BuiltinType::Id); \
}
6857#include "clang/Basic/OpenCLImageTypes.def"

6859inline bool Type::isSamplerT() const {
return isSpecificBuiltinType(BuiltinType::OCLSampler);
6861}

6863inline bool Type::isEventT() const {
return isSpecificBuiltinType(BuiltinType::OCLEvent);
6865}

6867inline bool Type::isClkEventT() const {
return isSpecificBuiltinType(BuiltinType::OCLClkEvent);
6869}

6871inline bool Type::isQueueT() const {
return isSpecificBuiltinType(BuiltinType::OCLQueue);
6873}

6875inline bool Type::isReserveIDT() const {
return isSpecificBuiltinType(BuiltinType::OCLReserveID);
6877}

6879inline bool Type::isImageType() const {
6880#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) is##Id##Type() ||
return
6882#include "clang/Basic/OpenCLImageTypes.def"
    false; // end boolean or operation
6884}

6886inline bool Type::isPipeType() const {
return isa<PipeType>(CanonicalType);
6888}

6890inline bool Type::isExtIntType() const {
return isa<ExtIntType>(CanonicalType);
6892}

6894#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
inline bool Type::is##Id##Type() const { \
  return isSpecificBuiltinType(BuiltinType::Id); \
}
6898#include "clang/Basic/OpenCLExtensionTypes.def"

6900inline bool Type::isOCLIntelSubgroupAVCType() const {
6901#define INTEL_SUBGROUP_AVC_TYPE(ExtType, Id) \
isOCLIntelSubgroupAVC##Id##Type() ||
return
6904#include "clang/Basic/OpenCLExtensionTypes.def"
  false; // end of boolean or operation
6906}

6908inline bool Type::isOCLExtOpaqueType() const {
6909#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) is##Id##Type() ||
return
6911#include "clang/Basic/OpenCLExtensionTypes.def"
  false; // end of boolean or operation
6913}

6915inline bool Type::isOpenCLSpecificType() const {
return isSamplerT() || isEventT() || isImageType() || isClkEventT() ||
       isQueueT() || isReserveIDT() || isPipeType() || isOCLExtOpaqueType();
6918}

6920inline bool Type::isTemplateTypeParmType() const {
return isa<TemplateTypeParmType>(CanonicalType);
6922}

6924inline bool Type::isSpecificBuiltinType(unsigned K) const {
if (const BuiltinType *BT = getAs<BuiltinType>()) {
  return BT->getKind() == static_cast<BuiltinType::Kind>(K);
}
return false;
6929}

6931inline bool Type::isPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  return BT->isPlaceholderType();
return false;
6935}

6937inline const BuiltinType *Type::getAsPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  if (BT->isPlaceholderType())
    return BT;
return nullptr;
6942}

6944inline bool Type::isSpecificPlaceholderType(unsigned K) const {
assert(BuiltinType::isPlaceholderTypeKind((BuiltinType::Kind) K))(static_cast<void> (0));
return isSpecificBuiltinType(K);
6947}

6949inline bool Type::isNonOverloadPlaceholderType() const {
if (const auto *BT = dyn_cast<BuiltinType>(this))
  return BT->isNonOverloadPlaceholderType();
return false;
6953}

6955inline bool Type::isVoidType() const {
return isSpecificBuiltinType(BuiltinType::Void);
6957}

6959inline bool Type::isHalfType() const {
// FIXME: Should we allow complex __fp16? Probably not.
return isSpecificBuiltinType(BuiltinType::Half);
6962}

6964inline bool Type::isFloat16Type() const {
return isSpecificBuiltinType(BuiltinType::Float16);
6966}

6968inline bool Type::isBFloat16Type() const {
return isSpecificBuiltinType(BuiltinType::BFloat16);
6970}

6972inline bool Type::isFloat128Type() const {
return isSpecificBuiltinType(BuiltinType::Float128);
6974}

6976inline bool Type::isNullPtrType() const {
return isSpecificBuiltinType(BuiltinType::NullPtr);
6978}

6980bool IsEnumDeclComplete(EnumDecl *);
6981bool IsEnumDeclScoped(EnumDecl *);

6983inline bool Type::isIntegerType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() >= BuiltinType::Bool &&
         BT->getKind() <= BuiltinType::Int128;
if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType)) {
  // Incomplete enum types are not treated as integer types.
  // FIXME: In C++, enum types are never integer types.
  return IsEnumDeclComplete(ET->getDecl()) &&
    !IsEnumDeclScoped(ET->getDecl());
}
return isExtIntType();
6994}

6996inline bool Type::isFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return BT->getKind() >= BuiltinType::ShortAccum &&
         BT->getKind() <= BuiltinType::SatULongFract;
}
return false;
7002}

7004inline bool Type::isFixedPointOrIntegerType() const {
return isFixedPointType() || isIntegerType();
7006}

7008inline bool Type::isSaturatedFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return BT->getKind() >= BuiltinType::SatShortAccum &&
         BT->getKind() <= BuiltinType::SatULongFract;
}
return false;
7014}

7016inline bool Type::isUnsaturatedFixedPointType() const {
return isFixedPointType() && !isSaturatedFixedPointType();
7018}

7020inline bool Type::isSignedFixedPointType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType)) {
  return ((BT->getKind() >= BuiltinType::ShortAccum &&
           BT->getKind() <= BuiltinType::LongAccum) ||
          (BT->getKind() >= BuiltinType::ShortFract &&
           BT->getKind() <= BuiltinType::LongFract) ||
          (BT->getKind() >= BuiltinType::SatShortAccum &&
           BT->getKind() <= BuiltinType::SatLongAccum) ||
          (BT->getKind() >= BuiltinType::SatShortFract &&
           BT->getKind() <= BuiltinType::SatLongFract));
}
return false;
7032}

7034inline bool Type::isUnsignedFixedPointType() const {
return isFixedPointType() && !isSignedFixedPointType();
7036}

7038inline bool Type::isScalarType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() > BuiltinType::Void &&
         BT->getKind() <= BuiltinType::NullPtr;
if (const EnumType *ET = dyn_cast<EnumType>(CanonicalType))
  // Enums are scalar types, but only if they are defined.  Incomplete enums
  // are not treated as scalar types.
  return IsEnumDeclComplete(ET->getDecl());
return isa<PointerType>(CanonicalType) ||
       isa<BlockPointerType>(CanonicalType) ||
       isa<MemberPointerType>(CanonicalType) ||
       isa<ComplexType>(CanonicalType) ||
       isa<ObjCObjectPointerType>(CanonicalType) ||
       isExtIntType();
7052}

7054inline bool Type::isIntegralOrEnumerationType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() >= BuiltinType::Bool &&
         BT->getKind() <= BuiltinType::Int128;

// Check for a complete enum type; incomplete enum types are not properly an
// enumeration type in the sense required here.
if (const auto *ET = dyn_cast<EnumType>(CanonicalType))
  return IsEnumDeclComplete(ET->getDecl());

return isExtIntType();
7065}

7067inline bool Type::isBooleanType() const {
if (const auto *BT = dyn_cast<BuiltinType>(CanonicalType))
  return BT->getKind() == BuiltinType::Bool;
return false;
7071}

7073inline bool Type::isUndeducedType() const {
auto *DT = getContainedDeducedType();
return DT && !DT->isDeduced();
7076}

7078/// Determines whether this is a type for which one can define
7079/// an overloaded operator.
7080inline bool Type::isOverloadableType() const {
return isDependentType() || isRecordType() || isEnumeralType();
7082}

7084/// Determines whether this type is written as a typedef-name.
7085inline bool Type::isTypedefNameType() const {
if (getAs<TypedefType>())
  return true;
if (auto *TST = getAs<TemplateSpecializationType>())
  return TST->isTypeAlias();
return false;
7091}

7093/// Determines whether this type can decay to a pointer type.
7094inline bool Type::canDecayToPointerType() const {
return isFunctionType() || isArrayType();
7096}

7098inline bool Type::hasPointerRepresentation() const {
return (isPointerType() || isReferenceType() || isBlockPointerType() ||
        isObjCObjectPointerType() || isNullPtrType());
7101}

7103inline bool Type::hasObjCPointerRepresentation() const {
return isObjCObjectPointerType();
7105}

7107inline const Type *Type::getBaseElementTypeUnsafe() const {
const Type *type = this;
while (const ArrayType *arrayType = type->getAsArrayTypeUnsafe())
  type = arrayType->getElementType().getTypePtr();
return type;
7112}

7114inline const Type *Type::getPointeeOrArrayElementType() const {
const Type *type = this;
if (type->isAnyPointerType())
  return type->getPointeeType().getTypePtr();
else if (type->isArrayType())
  return type->getBaseElementTypeUnsafe();
return type;
7121}
7122/// Insertion operator for partial diagnostics. This allows sending adress
7123/// spaces into a diagnostic with <<.
7124inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           LangAS AS) {
PD.AddTaggedVal(static_cast<std::underlying_type_t<LangAS>>(AS),
                DiagnosticsEngine::ArgumentKind::ak_addrspace);
return PD;
7129}

7131/// Insertion operator for partial diagnostics. This allows sending Qualifiers
7132/// into a diagnostic with <<.
7133inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           Qualifiers Q) {
PD.AddTaggedVal(Q.getAsOpaqueValue(),
                DiagnosticsEngine::ArgumentKind::ak_qual);
return PD;
7138}

7140/// Insertion operator for partial diagnostics.  This allows sending QualType's
7141/// into a diagnostic with <<.
7142inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           QualType T) {
PD.AddTaggedVal(reinterpret_cast<intptr_t>(T.getAsOpaquePtr()),
                DiagnosticsEngine::ak_qualtype);
return PD;
7147}

7149// Helper class template that is used by Type::getAs to ensure that one does
7150// not try to look through a qualified type to get to an array type.
7151template <typename T>
7152using TypeIsArrayType =
  std::integral_constant<bool, std::is_same<T, ArrayType>::value ||
                                   std::is_base_of<ArrayType, T>::value>;

7156// Member-template getAs<specific type>'.
7157template <typename T> const T *Type::getAs() const {
static_assert(!TypeIsArrayType<T>::value,
              "ArrayType cannot be used with getAs!");

// If this is directly a T type, return it.
if (const auto *Ty = dyn_cast<T>(this))
  return Ty;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<T>(CanonicalType))
  return nullptr;

// If this is a typedef for the type, strip the typedef off without
// losing all typedef information.
return cast<T>(getUnqualifiedDesugaredType());
7172}

7174template <typename T> const T *Type::getAsAdjusted() const {
static_assert(!TypeIsArrayType<T>::value, "ArrayType cannot be used with getAsAdjusted!");

// If this is directly a T type, return it.
if (const auto *Ty = dyn_cast<T>(this))
  return Ty;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<T>(CanonicalType))
  return nullptr;

// Strip off type adjustments that do not modify the underlying nature of the
// type.
const Type *Ty = this;
while (Ty) {
  if (const auto *A = dyn_cast<AttributedType>(Ty))
    Ty = A->getModifiedType().getTypePtr();
  else if (const auto *E = dyn_cast<ElaboratedType>(Ty))
    Ty = E->desugar().getTypePtr();
  else if (const auto *P = dyn_cast<ParenType>(Ty))
    Ty = P->desugar().getTypePtr();
  else if (const auto *A = dyn_cast<AdjustedType>(Ty))
    Ty = A->desugar().getTypePtr();
  else if (const auto *M = dyn_cast<MacroQualifiedType>(Ty))
    Ty = M->desugar().getTypePtr();
  else
    break;
}

// Just because the canonical type is correct does not mean we can use cast<>,
// since we may not have stripped off all the sugar down to the base type.
return dyn_cast<T>(Ty);
7206}

7208inline const ArrayType *Type::getAsArrayTypeUnsafe() const {
// If this is directly an array type, return it.
if (const auto *arr = dyn_cast<ArrayType>(this))
  return arr;

// If the canonical form of this type isn't the right kind, reject it.
if (!isa<ArrayType>(CanonicalType))
  return nullptr;

// If this is a typedef for the type, strip the typedef off without
// losing all typedef information.
return cast<ArrayType>(getUnqualifiedDesugaredType());
7220}

7222template <typename T> const T *Type::castAs() const {
static_assert(!TypeIsArrayType<T>::value,
              "ArrayType cannot be used with castAs!");

if (const auto *ty = dyn_cast<T>(this)) return ty;
assert(isa<T>(CanonicalType))(static_cast<void> (0));
return cast<T>(getUnqualifiedDesugaredType());
7229}

7231inline const ArrayType *Type::castAsArrayTypeUnsafe() const {
assert(isa<ArrayType>(CanonicalType))(static_cast<void> (0));
if (const auto *arr = dyn_cast<ArrayType>(this)) return arr;
return cast<ArrayType>(getUnqualifiedDesugaredType());
7235}

7237DecayedType::DecayedType(QualType OriginalType, QualType DecayedPtr,
                       QualType CanonicalPtr)
  : AdjustedType(Decayed, OriginalType, DecayedPtr, CanonicalPtr) {
7240#ifndef NDEBUG1
QualType Adjusted = getAdjustedType();
(void)AttributedType::stripOuterNullability(Adjusted);
assert(isa<PointerType>(Adjusted))(static_cast<void> (0));
7244#endif
7245}

7247QualType DecayedType::getPointeeType() const {
QualType Decayed = getDecayedType();
(void)AttributedType::stripOuterNullability(Decayed);
return cast<PointerType>(Decayed)->getPointeeType();
7251}

7253// Get the decimal string representation of a fixed point type, represented
7254// as a scaled integer.
7255// TODO: At some point, we should change the arguments to instead just accept an
7256// APFixedPoint instead of APSInt and scale.
7257void FixedPointValueToString(SmallVectorImpl<char> &Str, llvm::APSInt Val,
                           unsigned Scale);

7260} // namespace clang

7262#endif // LLVM_CLANG_AST_TYPE_H