/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprObjC.cpp

Bug Summary

File:	src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprObjC.cpp
Warning:	line 2617, column 7 Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaExprObjC.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 -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include/clang/Sema -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../include -I /usr/src/gnu/usr.bin/clang/libclangSema/obj -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprObjC.cpp

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprObjC.cpp

→

1//===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
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 file implements semantic analysis for Objective-C expressions.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/AST/ASTContext.h"
14#include "clang/AST/DeclObjC.h"
15#include "clang/AST/ExprObjC.h"
16#include "clang/AST/StmtVisitor.h"
17#include "clang/AST/TypeLoc.h"
18#include "clang/Analysis/DomainSpecific/CocoaConventions.h"
19#include "clang/Basic/Builtins.h"
20#include "clang/Edit/Commit.h"
21#include "clang/Edit/Rewriters.h"
22#include "clang/Lex/Preprocessor.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Lookup.h"
25#include "clang/Sema/Scope.h"
26#include "clang/Sema/ScopeInfo.h"
27#include "clang/Sema/SemaInternal.h"
28#include "llvm/ADT/SmallString.h"
29#include "llvm/Support/ConvertUTF.h"

31using namespace clang;
32using namespace sema;
33using llvm::makeArrayRef;

35ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
                                      ArrayRef<Expr *> Strings) {
// Most ObjC strings are formed out of a single piece.  However, we *can*
// have strings formed out of multiple @ strings with multiple pptokens in
// each one, e.g. @"foo" "bar" @"baz" "qux"   which need to be turned into one
// StringLiteral for ObjCStringLiteral to hold onto.
StringLiteral *S = cast<StringLiteral>(Strings[0]);

// If we have a multi-part string, merge it all together.
if (Strings.size() != 1) {
  // Concatenate objc strings.
  SmallString<128> StrBuf;
  SmallVector<SourceLocation, 8> StrLocs;

  for (Expr *E : Strings) {
    S = cast<StringLiteral>(E);

    // ObjC strings can't be wide or UTF.
    if (!S->isAscii()) {
      Diag(S->getBeginLoc(), diag::err_cfstring_literal_not_string_constant)
          << S->getSourceRange();
      return true;
    }

    // Append the string.
    StrBuf += S->getString();

    // Get the locations of the string tokens.
    StrLocs.append(S->tokloc_begin(), S->tokloc_end());
  }

  // Create the aggregate string with the appropriate content and location
  // information.
  const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType());
  assert(CAT && "String literal not of constant array type!")((void)0);
  QualType StrTy = Context.getConstantArrayType(
      CAT->getElementType(), llvm::APInt(32, StrBuf.size() + 1), nullptr,
      CAT->getSizeModifier(), CAT->getIndexTypeCVRQualifiers());
  S = StringLiteral::Create(Context, StrBuf, StringLiteral::Ascii,
                            /*Pascal=*/false, StrTy, &StrLocs[0],
                            StrLocs.size());
}

return BuildObjCStringLiteral(AtLocs[0], S);
79}

81ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
// Verify that this composite string is acceptable for ObjC strings.
if (CheckObjCString(S))
  return true;

// Initialize the constant string interface lazily. This assumes
// the NSString interface is seen in this translation unit. Note: We
// don't use NSConstantString, since the runtime team considers this
// interface private (even though it appears in the header files).
QualType Ty = Context.getObjCConstantStringInterface();
if (!Ty.isNull()) {
  Ty = Context.getObjCObjectPointerType(Ty);
} else if (getLangOpts().NoConstantCFStrings) {
  IdentifierInfo *NSIdent=nullptr;
  std::string StringClass(getLangOpts().ObjCConstantStringClass);

  if (StringClass.empty())
    NSIdent = &Context.Idents.get("NSConstantString");
  else
    NSIdent = &Context.Idents.get(StringClass);

  NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
                                   LookupOrdinaryName);
  if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
    Context.setObjCConstantStringInterface(StrIF);
    Ty = Context.getObjCConstantStringInterface();
    Ty = Context.getObjCObjectPointerType(Ty);
  } else {
    // If there is no NSConstantString interface defined then treat this
    // as error and recover from it.
    Diag(S->getBeginLoc(), diag::err_no_nsconstant_string_class)
        << NSIdent << S->getSourceRange();
    Ty = Context.getObjCIdType();
  }
} else {
  IdentifierInfo *NSIdent = NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
  NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
                                   LookupOrdinaryName);
  if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
    Context.setObjCConstantStringInterface(StrIF);
    Ty = Context.getObjCConstantStringInterface();
    Ty = Context.getObjCObjectPointerType(Ty);
  } else {
    // If there is no NSString interface defined, implicitly declare
    // a @class NSString; and use that instead. This is to make sure
    // type of an NSString literal is represented correctly, instead of
    // being an 'id' type.
    Ty = Context.getObjCNSStringType();
    if (Ty.isNull()) {
      ObjCInterfaceDecl *NSStringIDecl =
        ObjCInterfaceDecl::Create (Context,
                                   Context.getTranslationUnitDecl(),
                                   SourceLocation(), NSIdent,
                                   nullptr, nullptr, SourceLocation());
      Ty = Context.getObjCInterfaceType(NSStringIDecl);
      Context.setObjCNSStringType(Ty);
    }
    Ty = Context.getObjCObjectPointerType(Ty);
  }
}

return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
143}

145/// Emits an error if the given method does not exist, or if the return
146/// type is not an Objective-C object.
147static bool validateBoxingMethod(Sema &S, SourceLocation Loc,
                               const ObjCInterfaceDecl *Class,
                               Selector Sel, const ObjCMethodDecl *Method) {
if (!Method) {
  // FIXME: Is there a better way to avoid quotes than using getName()?
  S.Diag(Loc, diag::err_undeclared_boxing_method) << Sel << Class->getName();
  return false;
}

// Make sure the return type is reasonable.
QualType ReturnType = Method->getReturnType();
if (!ReturnType->isObjCObjectPointerType()) {
  S.Diag(Loc, diag::err_objc_literal_method_sig)
    << Sel;
  S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
    << ReturnType;
  return false;
}

return true;
167}

169/// Maps ObjCLiteralKind to NSClassIdKindKind
170static NSAPI::NSClassIdKindKind ClassKindFromLiteralKind(
                                          Sema::ObjCLiteralKind LiteralKind) {
switch (LiteralKind) {
  case Sema::LK_Array:
    return NSAPI::ClassId_NSArray;
  case Sema::LK_Dictionary:
    return NSAPI::ClassId_NSDictionary;
  case Sema::LK_Numeric:
    return NSAPI::ClassId_NSNumber;
  case Sema::LK_String:
    return NSAPI::ClassId_NSString;
  case Sema::LK_Boxed:
    return NSAPI::ClassId_NSValue;

  // there is no corresponding matching
  // between LK_None/LK_Block and NSClassIdKindKind
  case Sema::LK_Block:
  case Sema::LK_None:
    break;
}
llvm_unreachable("LiteralKind can't be converted into a ClassKind")__builtin_unreachable();
191}

193/// Validates ObjCInterfaceDecl availability.
194/// ObjCInterfaceDecl, used to create ObjC literals, should be defined
195/// if clang not in a debugger mode.
196static bool ValidateObjCLiteralInterfaceDecl(Sema &S, ObjCInterfaceDecl *Decl,
                                          SourceLocation Loc,
                                          Sema::ObjCLiteralKind LiteralKind) {
if (!Decl) {
  NSAPI::NSClassIdKindKind Kind = ClassKindFromLiteralKind(LiteralKind);
  IdentifierInfo *II = S.NSAPIObj->getNSClassId(Kind);
  S.Diag(Loc, diag::err_undeclared_objc_literal_class)
    << II->getName() << LiteralKind;
  return false;
} else if (!Decl->hasDefinition() && !S.getLangOpts().DebuggerObjCLiteral) {
  S.Diag(Loc, diag::err_undeclared_objc_literal_class)
    << Decl->getName() << LiteralKind;
  S.Diag(Decl->getLocation(), diag::note_forward_class);
  return false;
}

return true;
213}

215/// Looks up ObjCInterfaceDecl of a given NSClassIdKindKind.
216/// Used to create ObjC literals, such as NSDictionary (@{}),
217/// NSArray (@[]) and Boxed Expressions (@())
218static ObjCInterfaceDecl *LookupObjCInterfaceDeclForLiteral(Sema &S,
                                          SourceLocation Loc,
                                          Sema::ObjCLiteralKind LiteralKind) {
NSAPI::NSClassIdKindKind ClassKind = ClassKindFromLiteralKind(LiteralKind);
IdentifierInfo *II = S.NSAPIObj->getNSClassId(ClassKind);
NamedDecl *IF = S.LookupSingleName(S.TUScope, II, Loc,
                                   Sema::LookupOrdinaryName);
ObjCInterfaceDecl *ID = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
if (!ID && S.getLangOpts().DebuggerObjCLiteral) {
  ASTContext &Context = S.Context;
  TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
  ID = ObjCInterfaceDecl::Create (Context, TU, SourceLocation(), II,
                                  nullptr, nullptr, SourceLocation());
}

if (!ValidateObjCLiteralInterfaceDecl(S, ID, Loc, LiteralKind)) {
  ID = nullptr;
}

return ID;
238}

240/// Retrieve the NSNumber factory method that should be used to create
241/// an Objective-C literal for the given type.
242static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
                                              QualType NumberType,
                                              bool isLiteral = false,
                                              SourceRange R = SourceRange()) {
Optional<NSAPI::NSNumberLiteralMethodKind> Kind =
    S.NSAPIObj->getNSNumberFactoryMethodKind(NumberType);

if (!Kind) {
  if (isLiteral) {
    S.Diag(Loc, diag::err_invalid_nsnumber_type)
      << NumberType << R;
  }
  return nullptr;
}

// If we already looked up this method, we're done.
if (S.NSNumberLiteralMethods[*Kind])
  return S.NSNumberLiteralMethods[*Kind];

Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
                                                      /*Instance=*/false);

ASTContext &CX = S.Context;

// Look up the NSNumber class, if we haven't done so already. It's cached
// in the Sema instance.
if (!S.NSNumberDecl) {
  S.NSNumberDecl = LookupObjCInterfaceDeclForLiteral(S, Loc,
                                                     Sema::LK_Numeric);
  if (!S.NSNumberDecl) {
    return nullptr;
  }
}

if (S.NSNumberPointer.isNull()) {
  // generate the pointer to NSNumber type.
  QualType NSNumberObject = CX.getObjCInterfaceType(S.NSNumberDecl);
  S.NSNumberPointer = CX.getObjCObjectPointerType(NSNumberObject);
}

// Look for the appropriate method within NSNumber.
ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);
if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
  // create a stub definition this NSNumber factory method.
  TypeSourceInfo *ReturnTInfo = nullptr;
  Method =
      ObjCMethodDecl::Create(CX, SourceLocation(), SourceLocation(), Sel,
                             S.NSNumberPointer, ReturnTInfo, S.NSNumberDecl,
                             /*isInstance=*/false, /*isVariadic=*/false,
                             /*isPropertyAccessor=*/false,
                             /*isSynthesizedAccessorStub=*/false,
                             /*isImplicitlyDeclared=*/true,
                             /*isDefined=*/false, ObjCMethodDecl::Required,
                             /*HasRelatedResultType=*/false);
  ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
                                           SourceLocation(), SourceLocation(),
                                           &CX.Idents.get("value"),
                                           NumberType, /*TInfo=*/nullptr,
                                           SC_None, nullptr);
  Method->setMethodParams(S.Context, value, None);
}

if (!validateBoxingMethod(S, Loc, S.NSNumberDecl, Sel, Method))
  return nullptr;

// Note: if the parameter type is out-of-line, we'll catch it later in the
// implicit conversion.

S.NSNumberLiteralMethods[*Kind] = Method;
return Method;
312}

314/// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
315/// numeric literal expression. Type of the expression will be "NSNumber *".
316ExprResult Sema::BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number) {
// Determine the type of the literal.
QualType NumberType = Number->getType();
if (CharacterLiteral *Char = dyn_cast<CharacterLiteral>(Number)) {
  // In C, character literals have type 'int'. That's not the type we want
  // to use to determine the Objective-c literal kind.
  switch (Char->getKind()) {
  case CharacterLiteral::Ascii:
  case CharacterLiteral::UTF8:
    NumberType = Context.CharTy;
    break;

  case CharacterLiteral::Wide:
    NumberType = Context.getWideCharType();
    break;

  case CharacterLiteral::UTF16:
    NumberType = Context.Char16Ty;
    break;

  case CharacterLiteral::UTF32:
    NumberType = Context.Char32Ty;
    break;
  }
}

// Look for the appropriate method within NSNumber.
// Construct the literal.
SourceRange NR(Number->getSourceRange());
ObjCMethodDecl *Method = getNSNumberFactoryMethod(*this, AtLoc, NumberType,
                                                  true, NR);
if (!Method)
  return ExprError();

// Convert the number to the type that the parameter expects.
ParmVarDecl *ParamDecl = Method->parameters()[0];
InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
                                                                  ParamDecl);
ExprResult ConvertedNumber = PerformCopyInitialization(Entity,
                                                       SourceLocation(),
                                                       Number);
if (ConvertedNumber.isInvalid())
  return ExprError();
Number = ConvertedNumber.get();

// Use the effective source range of the literal, including the leading '@'.
return MaybeBindToTemporary(
         new (Context) ObjCBoxedExpr(Number, NSNumberPointer, Method,
                                     SourceRange(AtLoc, NR.getEnd())));
365}

367ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation AtLoc,
                                    SourceLocation ValueLoc,
                                    bool Value) {
ExprResult Inner;
if (getLangOpts().CPlusPlus) {
  Inner = ActOnCXXBoolLiteral(ValueLoc, Value? tok::kw_true : tok::kw_false);
} else {
  // C doesn't actually have a way to represent literal values of type
  // _Bool. So, we'll use 0/1 and implicit cast to _Bool.
  Inner = ActOnIntegerConstant(ValueLoc, Value? 1 : 0);
  Inner = ImpCastExprToType(Inner.get(), Context.BoolTy,
                            CK_IntegralToBoolean);
}

return BuildObjCNumericLiteral(AtLoc, Inner.get());
382}

384/// Check that the given expression is a valid element of an Objective-C
385/// collection literal.
386static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element,
                                                  QualType T,
                                                  bool ArrayLiteral = false) {
// If the expression is type-dependent, there's nothing for us to do.
if (Element->isTypeDependent())
  return Element;

ExprResult Result = S.CheckPlaceholderExpr(Element);
if (Result.isInvalid())
  return ExprError();
Element = Result.get();

// In C++, check for an implicit conversion to an Objective-C object pointer
// type.
if (S.getLangOpts().CPlusPlus && Element->getType()->isRecordType()) {
  InitializedEntity Entity
    = InitializedEntity::InitializeParameter(S.Context, T,
                                             /*Consumed=*/false);
  InitializationKind Kind = InitializationKind::CreateCopy(
      Element->getBeginLoc(), SourceLocation());
  InitializationSequence Seq(S, Entity, Kind, Element);
  if (!Seq.Failed())
    return Seq.Perform(S, Entity, Kind, Element);
}

Expr *OrigElement = Element;

// Perform lvalue-to-rvalue conversion.
Result = S.DefaultLvalueConversion(Element);
if (Result.isInvalid())
  return ExprError();
Element = Result.get();

// Make sure that we have an Objective-C pointer type or block.
if (!Element->getType()->isObjCObjectPointerType() &&
    !Element->getType()->isBlockPointerType()) {
  bool Recovered = false;

  // If this is potentially an Objective-C numeric literal, add the '@'.
  if (isa<IntegerLiteral>(OrigElement) ||
      isa<CharacterLiteral>(OrigElement) ||
      isa<FloatingLiteral>(OrigElement) ||
      isa<ObjCBoolLiteralExpr>(OrigElement) ||
      isa<CXXBoolLiteralExpr>(OrigElement)) {
    if (S.NSAPIObj->getNSNumberFactoryMethodKind(OrigElement->getType())) {
      int Which = isa<CharacterLiteral>(OrigElement) ? 1
                : (isa<CXXBoolLiteralExpr>(OrigElement) ||
                   isa<ObjCBoolLiteralExpr>(OrigElement)) ? 2
                : 3;

      S.Diag(OrigElement->getBeginLoc(), diag::err_box_literal_collection)
          << Which << OrigElement->getSourceRange()
          << FixItHint::CreateInsertion(OrigElement->getBeginLoc(), "@");

      Result =
          S.BuildObjCNumericLiteral(OrigElement->getBeginLoc(), OrigElement);
      if (Result.isInvalid())
        return ExprError();

      Element = Result.get();
      Recovered = true;
    }
  }
  // If this is potentially an Objective-C string literal, add the '@'.
  else if (StringLiteral *String = dyn_cast<StringLiteral>(OrigElement)) {
    if (String->isAscii()) {
      S.Diag(OrigElement->getBeginLoc(), diag::err_box_literal_collection)
          << 0 << OrigElement->getSourceRange()
          << FixItHint::CreateInsertion(OrigElement->getBeginLoc(), "@");

      Result = S.BuildObjCStringLiteral(OrigElement->getBeginLoc(), String);
      if (Result.isInvalid())
        return ExprError();

      Element = Result.get();
      Recovered = true;
    }
  }

  if (!Recovered) {
    S.Diag(Element->getBeginLoc(), diag::err_invalid_collection_element)
        << Element->getType();
    return ExprError();
  }
}
if (ArrayLiteral)
  if (ObjCStringLiteral *getString =
        dyn_cast<ObjCStringLiteral>(OrigElement)) {
    if (StringLiteral *SL = getString->getString()) {
      unsigned numConcat = SL->getNumConcatenated();
      if (numConcat > 1) {
        // Only warn if the concatenated string doesn't come from a macro.
        bool hasMacro = false;
        for (unsigned i = 0; i < numConcat ; ++i)
          if (SL->getStrTokenLoc(i).isMacroID()) {
            hasMacro = true;
            break;
          }
        if (!hasMacro)
          S.Diag(Element->getBeginLoc(),
                 diag::warn_concatenated_nsarray_literal)
              << Element->getType();
      }
    }
  }

// Make sure that the element has the type that the container factory
// function expects.
return S.PerformCopyInitialization(
    InitializedEntity::InitializeParameter(S.Context, T,
                                           /*Consumed=*/false),
    Element->getBeginLoc(), Element);
498}

500ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
if (ValueExpr->isTypeDependent()) {
  ObjCBoxedExpr *BoxedExpr =
    new (Context) ObjCBoxedExpr(ValueExpr, Context.DependentTy, nullptr, SR);
  return BoxedExpr;
}
ObjCMethodDecl *BoxingMethod = nullptr;
QualType BoxedType;
// Convert the expression to an RValue, so we can check for pointer types...
ExprResult RValue = DefaultFunctionArrayLvalueConversion(ValueExpr);
if (RValue.isInvalid()) {
  return ExprError();
}
SourceLocation Loc = SR.getBegin();
ValueExpr = RValue.get();
QualType ValueType(ValueExpr->getType());
if (const PointerType *PT = ValueType->getAs<PointerType>()) {
  QualType PointeeType = PT->getPointeeType();
  if (Context.hasSameUnqualifiedType(PointeeType, Context.CharTy)) {

    if (!NSStringDecl) {
      NSStringDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
                                                       Sema::LK_String);
      if (!NSStringDecl) {
        return ExprError();
      }
      QualType NSStringObject = Context.getObjCInterfaceType(NSStringDecl);
      NSStringPointer = Context.getObjCObjectPointerType(NSStringObject);
    }

    // The boxed expression can be emitted as a compile time constant if it is
    // a string literal whose character encoding is compatible with UTF-8.
    if (auto *CE = dyn_cast<ImplicitCastExpr>(ValueExpr))
      if (CE->getCastKind() == CK_ArrayToPointerDecay)
        if (auto *SL =
                dyn_cast<StringLiteral>(CE->getSubExpr()->IgnoreParens())) {
          assert((SL->isAscii() || SL->isUTF8()) &&((void)0)
                 "unexpected character encoding")((void)0);
          StringRef Str = SL->getString();
          const llvm::UTF8 *StrBegin = Str.bytes_begin();
          const llvm::UTF8 *StrEnd = Str.bytes_end();
          // Check that this is a valid UTF-8 string.
          if (llvm::isLegalUTF8String(&StrBegin, StrEnd)) {
            BoxedType = Context.getAttributedType(
                AttributedType::getNullabilityAttrKind(
                    NullabilityKind::NonNull),
                NSStringPointer, NSStringPointer);
            return new (Context) ObjCBoxedExpr(CE, BoxedType, nullptr, SR);
          }

          Diag(SL->getBeginLoc(), diag::warn_objc_boxing_invalid_utf8_string)
              << NSStringPointer << SL->getSourceRange();
        }

    if (!StringWithUTF8StringMethod) {
      IdentifierInfo *II = &Context.Idents.get("stringWithUTF8String");
      Selector stringWithUTF8String = Context.Selectors.getUnarySelector(II);

      // Look for the appropriate method within NSString.
      BoxingMethod = NSStringDecl->lookupClassMethod(stringWithUTF8String);
      if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
        // Debugger needs to work even if NSString hasn't been defined.
        TypeSourceInfo *ReturnTInfo = nullptr;
        ObjCMethodDecl *M = ObjCMethodDecl::Create(
            Context, SourceLocation(), SourceLocation(), stringWithUTF8String,
            NSStringPointer, ReturnTInfo, NSStringDecl,
            /*isInstance=*/false, /*isVariadic=*/false,
            /*isPropertyAccessor=*/false,
            /*isSynthesizedAccessorStub=*/false,
            /*isImplicitlyDeclared=*/true,
            /*isDefined=*/false, ObjCMethodDecl::Required,
            /*HasRelatedResultType=*/false);
        QualType ConstCharType = Context.CharTy.withConst();
        ParmVarDecl *value =
          ParmVarDecl::Create(Context, M,
                              SourceLocation(), SourceLocation(),
                              &Context.Idents.get("value"),
                              Context.getPointerType(ConstCharType),
                              /*TInfo=*/nullptr,
                              SC_None, nullptr);
        M->setMethodParams(Context, value, None);
        BoxingMethod = M;
      }

      if (!validateBoxingMethod(*this, Loc, NSStringDecl,
                                stringWithUTF8String, BoxingMethod))
         return ExprError();

      StringWithUTF8StringMethod = BoxingMethod;
    }

    BoxingMethod = StringWithUTF8StringMethod;
    BoxedType = NSStringPointer;
    // Transfer the nullability from method's return type.
    Optional<NullabilityKind> Nullability =
        BoxingMethod->getReturnType()->getNullability(Context);
    if (Nullability)
      BoxedType = Context.getAttributedType(
          AttributedType::getNullabilityAttrKind(*Nullability), BoxedType,
          BoxedType);
  }
} else if (ValueType->isBuiltinType()) {
  // The other types we support are numeric, char and BOOL/bool. We could also
  // provide limited support for structure types, such as NSRange, NSRect, and
  // NSSize. See NSValue (NSValueGeometryExtensions) in <Foundation/NSGeometry.h>
  // for more details.

  // Check for a top-level character literal.
  if (const CharacterLiteral *Char =
      dyn_cast<CharacterLiteral>(ValueExpr->IgnoreParens())) {
    // In C, character literals have type 'int'. That's not the type we want
    // to use to determine the Objective-c literal kind.
    switch (Char->getKind()) {
    case CharacterLiteral::Ascii:
    case CharacterLiteral::UTF8:
      ValueType = Context.CharTy;
      break;

    case CharacterLiteral::Wide:
      ValueType = Context.getWideCharType();
      break;

    case CharacterLiteral::UTF16:
      ValueType = Context.Char16Ty;
      break;

    case CharacterLiteral::UTF32:
      ValueType = Context.Char32Ty;
      break;
    }
  }
  // FIXME:  Do I need to do anything special with BoolTy expressions?

  // Look for the appropriate method within NSNumber.
  BoxingMethod = getNSNumberFactoryMethod(*this, Loc, ValueType);
  BoxedType = NSNumberPointer;
} else if (const EnumType *ET = ValueType->getAs<EnumType>()) {
  if (!ET->getDecl()->isComplete()) {
    Diag(Loc, diag::err_objc_incomplete_boxed_expression_type)
      << ValueType << ValueExpr->getSourceRange();
    return ExprError();
  }

  BoxingMethod = getNSNumberFactoryMethod(*this, Loc,
                                          ET->getDecl()->getIntegerType());
  BoxedType = NSNumberPointer;
} else if (ValueType->isObjCBoxableRecordType()) {
  // Support for structure types, that marked as objc_boxable
  // struct __attribute__((objc_boxable)) s { ... };

  // Look up the NSValue class, if we haven't done so already. It's cached
  // in the Sema instance.
  if (!NSValueDecl) {
    NSValueDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
                                                    Sema::LK_Boxed);
    if (!NSValueDecl) {
      return ExprError();
    }

    // generate the pointer to NSValue type.
    QualType NSValueObject = Context.getObjCInterfaceType(NSValueDecl);
    NSValuePointer = Context.getObjCObjectPointerType(NSValueObject);
  }

  if (!ValueWithBytesObjCTypeMethod) {
    IdentifierInfo *II[] = {
      &Context.Idents.get("valueWithBytes"),
      &Context.Idents.get("objCType")
    };
    Selector ValueWithBytesObjCType = Context.Selectors.getSelector(2, II);

    // Look for the appropriate method within NSValue.
    BoxingMethod = NSValueDecl->lookupClassMethod(ValueWithBytesObjCType);
    if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
      // Debugger needs to work even if NSValue hasn't been defined.
      TypeSourceInfo *ReturnTInfo = nullptr;
      ObjCMethodDecl *M = ObjCMethodDecl::Create(
          Context, SourceLocation(), SourceLocation(), ValueWithBytesObjCType,
          NSValuePointer, ReturnTInfo, NSValueDecl,
          /*isInstance=*/false,
          /*isVariadic=*/false,
          /*isPropertyAccessor=*/false,
          /*isSynthesizedAccessorStub=*/false,
          /*isImplicitlyDeclared=*/true,
          /*isDefined=*/false, ObjCMethodDecl::Required,
          /*HasRelatedResultType=*/false);

      SmallVector<ParmVarDecl *, 2> Params;

      ParmVarDecl *bytes =
      ParmVarDecl::Create(Context, M,
                          SourceLocation(), SourceLocation(),
                          &Context.Idents.get("bytes"),
                          Context.VoidPtrTy.withConst(),
                          /*TInfo=*/nullptr,
                          SC_None, nullptr);
      Params.push_back(bytes);

      QualType ConstCharType = Context.CharTy.withConst();
      ParmVarDecl *type =
      ParmVarDecl::Create(Context, M,
                          SourceLocation(), SourceLocation(),
                          &Context.Idents.get("type"),
                          Context.getPointerType(ConstCharType),
                          /*TInfo=*/nullptr,
                          SC_None, nullptr);
      Params.push_back(type);

      M->setMethodParams(Context, Params, None);
      BoxingMethod = M;
    }

    if (!validateBoxingMethod(*this, Loc, NSValueDecl,
                              ValueWithBytesObjCType, BoxingMethod))
      return ExprError();

    ValueWithBytesObjCTypeMethod = BoxingMethod;
  }

  if (!ValueType.isTriviallyCopyableType(Context)) {
    Diag(Loc, diag::err_objc_non_trivially_copyable_boxed_expression_type)
      << ValueType << ValueExpr->getSourceRange();
    return ExprError();
  }

  BoxingMethod = ValueWithBytesObjCTypeMethod;
  BoxedType = NSValuePointer;
}

if (!BoxingMethod) {
  Diag(Loc, diag::err_objc_illegal_boxed_expression_type)
    << ValueType << ValueExpr->getSourceRange();
  return ExprError();
}

DiagnoseUseOfDecl(BoxingMethod, Loc);

ExprResult ConvertedValueExpr;
if (ValueType->isObjCBoxableRecordType()) {
  InitializedEntity IE = InitializedEntity::InitializeTemporary(ValueType);
  ConvertedValueExpr = PerformCopyInitialization(IE, ValueExpr->getExprLoc(),
                                                 ValueExpr);
} else {
  // Convert the expression to the type that the parameter requires.
  ParmVarDecl *ParamDecl = BoxingMethod->parameters()[0];
  InitializedEntity IE = InitializedEntity::InitializeParameter(Context,
                                                                ParamDecl);
  ConvertedValueExpr = PerformCopyInitialization(IE, SourceLocation(),
                                                 ValueExpr);
}

if (ConvertedValueExpr.isInvalid())
  return ExprError();
ValueExpr = ConvertedValueExpr.get();

ObjCBoxedExpr *BoxedExpr =
  new (Context) ObjCBoxedExpr(ValueExpr, BoxedType,
                                    BoxingMethod, SR);
return MaybeBindToTemporary(BoxedExpr);
759}

761/// Build an ObjC subscript pseudo-object expression, given that
762/// that's supported by the runtime.
763ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
                                      Expr *IndexExpr,
                                      ObjCMethodDecl *getterMethod,
                                      ObjCMethodDecl *setterMethod) {
assert(!LangOpts.isSubscriptPointerArithmetic())((void)0);

// We can't get dependent types here; our callers should have
// filtered them out.
assert((!BaseExpr->isTypeDependent() && !IndexExpr->isTypeDependent()) &&((void)0)
       "base or index cannot have dependent type here")((void)0);

// Filter out placeholders in the index.  In theory, overloads could
// be preserved here, although that might not actually work correctly.
ExprResult Result = CheckPlaceholderExpr(IndexExpr);
if (Result.isInvalid())
  return ExprError();
IndexExpr = Result.get();

// Perform lvalue-to-rvalue conversion on the base.
Result = DefaultLvalueConversion(BaseExpr);
if (Result.isInvalid())
  return ExprError();
BaseExpr = Result.get();

// Build the pseudo-object expression.
return new (Context) ObjCSubscriptRefExpr(
    BaseExpr, IndexExpr, Context.PseudoObjectTy, VK_LValue, OK_ObjCSubscript,
    getterMethod, setterMethod, RB);
791}

793ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
SourceLocation Loc = SR.getBegin();

if (!NSArrayDecl) {
  NSArrayDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
                                                  Sema::LK_Array);
  if (!NSArrayDecl) {
    return ExprError();
  }
}

// Find the arrayWithObjects:count: method, if we haven't done so already.
QualType IdT = Context.getObjCIdType();
if (!ArrayWithObjectsMethod) {
  Selector
    Sel = NSAPIObj->getNSArraySelector(NSAPI::NSArr_arrayWithObjectsCount);
  ObjCMethodDecl *Method = NSArrayDecl->lookupClassMethod(Sel);
  if (!Method && getLangOpts().DebuggerObjCLiteral) {
    TypeSourceInfo *ReturnTInfo = nullptr;
    Method = ObjCMethodDecl::Create(
        Context, SourceLocation(), SourceLocation(), Sel, IdT, ReturnTInfo,
        Context.getTranslationUnitDecl(), false /*Instance*/,
        false /*isVariadic*/,
        /*isPropertyAccessor=*/false, /*isSynthesizedAccessorStub=*/false,
        /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
        ObjCMethodDecl::Required, false);
    SmallVector<ParmVarDecl *, 2> Params;
    ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
                                               SourceLocation(),
                                               SourceLocation(),
                                               &Context.Idents.get("objects"),
                                               Context.getPointerType(IdT),
                                               /*TInfo=*/nullptr,
                                               SC_None, nullptr);
    Params.push_back(objects);
    ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
                                           SourceLocation(),
                                           SourceLocation(),
                                           &Context.Idents.get("cnt"),
                                           Context.UnsignedLongTy,
                                           /*TInfo=*/nullptr, SC_None,
                                           nullptr);
    Params.push_back(cnt);
    Method->setMethodParams(Context, Params, None);
  }

  if (!validateBoxingMethod(*this, Loc, NSArrayDecl, Sel, Method))
    return ExprError();

  // Dig out the type that all elements should be converted to.
  QualType T = Method->parameters()[0]->getType();
  const PointerType *PtrT = T->getAs<PointerType>();
  if (!PtrT ||
      !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
      << Sel;
    Diag(Method->parameters()[0]->getLocation(),
         diag::note_objc_literal_method_param)
      << 0 << T
      << Context.getPointerType(IdT.withConst());
    return ExprError();
  }

  // Check that the 'count' parameter is integral.
  if (!Method->parameters()[1]->getType()->isIntegerType()) {
    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
      << Sel;
    Diag(Method->parameters()[1]->getLocation(),
         diag::note_objc_literal_method_param)
      << 1
      << Method->parameters()[1]->getType()
      << "integral";
    return ExprError();
  }

  // We've found a good +arrayWithObjects:count: method. Save it!
  ArrayWithObjectsMethod = Method;
}

QualType ObjectsType = ArrayWithObjectsMethod->parameters()[0]->getType();
QualType RequiredType = ObjectsType->castAs<PointerType>()->getPointeeType();

// Check that each of the elements provided is valid in a collection literal,
// performing conversions as necessary.
Expr **ElementsBuffer = Elements.data();
for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
  ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
                                                           ElementsBuffer[I],
                                                           RequiredType, true);
  if (Converted.isInvalid())
    return ExprError();

  ElementsBuffer[I] = Converted.get();
}

QualType Ty
  = Context.getObjCObjectPointerType(
                                  Context.getObjCInterfaceType(NSArrayDecl));

return MaybeBindToTemporary(
         ObjCArrayLiteral::Create(Context, Elements, Ty,
                                  ArrayWithObjectsMethod, SR));
895}

897/// Check for duplicate keys in an ObjC dictionary literal. For instance:
898///   NSDictionary *nd = @{ @"foo" : @"bar", @"foo" : @"baz" };
899static void
900CheckObjCDictionaryLiteralDuplicateKeys(Sema &S,
                                      ObjCDictionaryLiteral *Literal) {
if (Literal->isValueDependent() || Literal->isTypeDependent())
  return;

// NSNumber has quite relaxed equality semantics (for instance, @YES is
// considered equal to @1.0). For now, ignore floating points and just do a
// bit-width and sign agnostic integer compare.
struct APSIntCompare {
  bool operator()(const llvm::APSInt &LHS, const llvm::APSInt &RHS) const {
    return llvm::APSInt::compareValues(LHS, RHS) < 0;
  }
};

llvm::DenseMap<StringRef, SourceLocation> StringKeys;
std::map<llvm::APSInt, SourceLocation, APSIntCompare> IntegralKeys;

auto checkOneKey = [&](auto &Map, const auto &Key, SourceLocation Loc) {
  auto Pair = Map.insert({Key, Loc});
  if (!Pair.second) {
    S.Diag(Loc, diag::warn_nsdictionary_duplicate_key);
    S.Diag(Pair.first->second, diag::note_nsdictionary_duplicate_key_here);
  }
};

for (unsigned Idx = 0, End = Literal->getNumElements(); Idx != End; ++Idx) {
  Expr *Key = Literal->getKeyValueElement(Idx).Key->IgnoreParenImpCasts();

  if (auto *StrLit = dyn_cast<ObjCStringLiteral>(Key)) {
    StringRef Bytes = StrLit->getString()->getBytes();
    SourceLocation Loc = StrLit->getExprLoc();
    checkOneKey(StringKeys, Bytes, Loc);
  }

  if (auto *BE = dyn_cast<ObjCBoxedExpr>(Key)) {
    Expr *Boxed = BE->getSubExpr();
    SourceLocation Loc = BE->getExprLoc();

    // Check for @("foo").
    if (auto *Str = dyn_cast<StringLiteral>(Boxed->IgnoreParenImpCasts())) {
      checkOneKey(StringKeys, Str->getBytes(), Loc);
      continue;
    }

    Expr::EvalResult Result;
    if (Boxed->EvaluateAsInt(Result, S.getASTContext(),
                             Expr::SE_AllowSideEffects)) {
      checkOneKey(IntegralKeys, Result.Val.getInt(), Loc);
    }
  }
}
951}

953ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
                            MutableArrayRef<ObjCDictionaryElement> Elements) {
SourceLocation Loc = SR.getBegin();

if (!NSDictionaryDecl) {
  NSDictionaryDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
                                                       Sema::LK_Dictionary);
  if (!NSDictionaryDecl) {
    return ExprError();
  }
}

// Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
// so already.
QualType IdT = Context.getObjCIdType();
if (!DictionaryWithObjectsMethod) {
  Selector Sel = NSAPIObj->getNSDictionarySelector(
                             NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
  ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
  if (!Method && getLangOpts().DebuggerObjCLiteral) {
    Method = ObjCMethodDecl::Create(
        Context, SourceLocation(), SourceLocation(), Sel, IdT,
        nullptr /*TypeSourceInfo */, Context.getTranslationUnitDecl(),
        false /*Instance*/, false /*isVariadic*/,
        /*isPropertyAccessor=*/false,
        /*isSynthesizedAccessorStub=*/false,
        /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
        ObjCMethodDecl::Required, false);
    SmallVector<ParmVarDecl *, 3> Params;
    ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
                                               SourceLocation(),
                                               SourceLocation(),
                                               &Context.Idents.get("objects"),
                                               Context.getPointerType(IdT),
                                               /*TInfo=*/nullptr, SC_None,
                                               nullptr);
    Params.push_back(objects);
    ParmVarDecl *keys = ParmVarDecl::Create(Context, Method,
                                            SourceLocation(),
                                            SourceLocation(),
                                            &Context.Idents.get("keys"),
                                            Context.getPointerType(IdT),
                                            /*TInfo=*/nullptr, SC_None,
                                            nullptr);
    Params.push_back(keys);
    ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
                                           SourceLocation(),
                                           SourceLocation(),
                                           &Context.Idents.get("cnt"),
                                           Context.UnsignedLongTy,
                                           /*TInfo=*/nullptr, SC_None,
                                           nullptr);
    Params.push_back(cnt);
    Method->setMethodParams(Context, Params, None);
  }

  if (!validateBoxingMethod(*this, SR.getBegin(), NSDictionaryDecl, Sel,
                            Method))
     return ExprError();

  // Dig out the type that all values should be converted to.
  QualType ValueT = Method->parameters()[0]->getType();
  const PointerType *PtrValue = ValueT->getAs<PointerType>();
  if (!PtrValue ||
      !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
      << Sel;
    Diag(Method->parameters()[0]->getLocation(),
         diag::note_objc_literal_method_param)
      << 0 << ValueT
      << Context.getPointerType(IdT.withConst());
    return ExprError();
  }

  // Dig out the type that all keys should be converted to.
  QualType KeyT = Method->parameters()[1]->getType();
  const PointerType *PtrKey = KeyT->getAs<PointerType>();
  if (!PtrKey ||
      !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
                                      IdT)) {
    bool err = true;
    if (PtrKey) {
      if (QIDNSCopying.isNull()) {
        // key argument of selector is id<NSCopying>?
        if (ObjCProtocolDecl *NSCopyingPDecl =
            LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
          ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
          QIDNSCopying =
            Context.getObjCObjectType(Context.ObjCBuiltinIdTy, { },
                                      llvm::makeArrayRef(
                                        (ObjCProtocolDecl**) PQ,
                                        1),
                                      false);
          QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
        }
      }
      if (!QIDNSCopying.isNull())
        err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
                                              QIDNSCopying);
    }

    if (err) {
      Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
        << Sel;
      Diag(Method->parameters()[1]->getLocation(),
           diag::note_objc_literal_method_param)
        << 1 << KeyT
        << Context.getPointerType(IdT.withConst());
      return ExprError();
    }
  }

  // Check that the 'count' parameter is integral.
  QualType CountType = Method->parameters()[2]->getType();
  if (!CountType->isIntegerType()) {
    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
      << Sel;
    Diag(Method->parameters()[2]->getLocation(),
         diag::note_objc_literal_method_param)
      << 2 << CountType
      << "integral";
    return ExprError();
  }

  // We've found a good +dictionaryWithObjects:keys:count: method; save it!
  DictionaryWithObjectsMethod = Method;
}

QualType ValuesT = DictionaryWithObjectsMethod->parameters()[0]->getType();
QualType ValueT = ValuesT->castAs<PointerType>()->getPointeeType();
QualType KeysT = DictionaryWithObjectsMethod->parameters()[1]->getType();
QualType KeyT = KeysT->castAs<PointerType>()->getPointeeType();

// Check that each of the keys and values provided is valid in a collection
// literal, performing conversions as necessary.
bool HasPackExpansions = false;
for (ObjCDictionaryElement &Element : Elements) {
  // Check the key.
  ExprResult Key = CheckObjCCollectionLiteralElement(*this, Element.Key,
                                                     KeyT);
  if (Key.isInvalid())
    return ExprError();

  // Check the value.
  ExprResult Value
    = CheckObjCCollectionLiteralElement(*this, Element.Value, ValueT);
  if (Value.isInvalid())
    return ExprError();

  Element.Key = Key.get();
  Element.Value = Value.get();

  if (Element.EllipsisLoc.isInvalid())
    continue;

  if (!Element.Key->containsUnexpandedParameterPack() &&
      !Element.Value->containsUnexpandedParameterPack()) {
    Diag(Element.EllipsisLoc,
         diag::err_pack_expansion_without_parameter_packs)
        << SourceRange(Element.Key->getBeginLoc(),
                       Element.Value->getEndLoc());
    return ExprError();
  }

  HasPackExpansions = true;
}

QualType Ty = Context.getObjCObjectPointerType(
    Context.getObjCInterfaceType(NSDictionaryDecl));

auto *Literal =
    ObjCDictionaryLiteral::Create(Context, Elements, HasPackExpansions, Ty,
                                  DictionaryWithObjectsMethod, SR);
CheckObjCDictionaryLiteralDuplicateKeys(*this, Literal);
return MaybeBindToTemporary(Literal);
1128}

1130ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
                                    TypeSourceInfo *EncodedTypeInfo,
                                    SourceLocation RParenLoc) {
QualType EncodedType = EncodedTypeInfo->getType();
QualType StrTy;
if (EncodedType->isDependentType())
  StrTy = Context.DependentTy;
else {
  if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
      !EncodedType->isVoidType()) // void is handled too.
    if (RequireCompleteType(AtLoc, EncodedType,
                            diag::err_incomplete_type_objc_at_encode,
                            EncodedTypeInfo->getTypeLoc()))
      return ExprError();

  std::string Str;
  QualType NotEncodedT;
  Context.getObjCEncodingForType(EncodedType, Str, nullptr, &NotEncodedT);
  if (!NotEncodedT.isNull())
    Diag(AtLoc, diag::warn_incomplete_encoded_type)
      << EncodedType << NotEncodedT;

  // The type of @encode is the same as the type of the corresponding string,
  // which is an array type.
  StrTy = Context.getStringLiteralArrayType(Context.CharTy, Str.size());
}

return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
1158}

1160ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
                                         SourceLocation EncodeLoc,
                                         SourceLocation LParenLoc,
                                         ParsedType ty,
                                         SourceLocation RParenLoc) {
// FIXME: Preserve type source info ?
TypeSourceInfo *TInfo;
QualType EncodedType = GetTypeFromParser(ty, &TInfo);
if (!TInfo)
  TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
                                           getLocForEndOfToken(LParenLoc));

return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
1173}

1175static bool HelperToDiagnoseMismatchedMethodsInGlobalPool(Sema &S,
                                             SourceLocation AtLoc,
                                             SourceLocation LParenLoc,
                                             SourceLocation RParenLoc,
                                             ObjCMethodDecl *Method,
                                             ObjCMethodList &MethList) {
ObjCMethodList *M = &MethList;
bool Warned = false;
for (M = M->getNext(); M; M=M->getNext()) {
  ObjCMethodDecl *MatchingMethodDecl = M->getMethod();
  if (MatchingMethodDecl == Method ||
      isa<ObjCImplDecl>(MatchingMethodDecl->getDeclContext()) ||
      MatchingMethodDecl->getSelector() != Method->getSelector())
    continue;
  if (!S.MatchTwoMethodDeclarations(Method,
                                    MatchingMethodDecl, Sema::MMS_loose)) {
    if (!Warned) {
      Warned = true;
      S.Diag(AtLoc, diag::warn_multiple_selectors)
        << Method->getSelector() << FixItHint::CreateInsertion(LParenLoc, "(")
        << FixItHint::CreateInsertion(RParenLoc, ")");
      S.Diag(Method->getLocation(), diag::note_method_declared_at)
        << Method->getDeclName();
    }
    S.Diag(MatchingMethodDecl->getLocation(), diag::note_method_declared_at)
      << MatchingMethodDecl->getDeclName();
  }
}
return Warned;
1204}

1206static void DiagnoseMismatchedSelectors(Sema &S, SourceLocation AtLoc,
                                      ObjCMethodDecl *Method,
                                      SourceLocation LParenLoc,
                                      SourceLocation RParenLoc,
                                      bool WarnMultipleSelectors) {
if (!WarnMultipleSelectors ||
    S.Diags.isIgnored(diag::warn_multiple_selectors, SourceLocation()))
  return;
bool Warned = false;
for (Sema::GlobalMethodPool::iterator b = S.MethodPool.begin(),
     e = S.MethodPool.end(); b != e; b++) {
  // first, instance methods
  ObjCMethodList &InstMethList = b->second.first;
  if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
                                                    Method, InstMethList))
    Warned = true;

  // second, class methods
  ObjCMethodList &ClsMethList = b->second.second;
  if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
                                                    Method, ClsMethList) || Warned)
    return;
}
1229}

1231static ObjCMethodDecl *LookupDirectMethodInMethodList(Sema &S, Selector Sel,
                                                    ObjCMethodList &MethList,
                                                    bool &onlyDirect,
                                                    bool &anyDirect) {
(void)Sel;
ObjCMethodList *M = &MethList;
ObjCMethodDecl *DirectMethod = nullptr;
for (; M; M = M->getNext()) {
  ObjCMethodDecl *Method = M->getMethod();
  if (!Method)
    continue;
  assert(Method->getSelector() == Sel && "Method with wrong selector in method list")((void)0);
  if (Method->isDirectMethod()) {
    anyDirect = true;
    DirectMethod = Method;
  } else
    onlyDirect = false;
}

return DirectMethod;
1251}

1253// Search the global pool for (potentially) direct methods matching the given
1254// selector. If a non-direct method is found, set \param onlyDirect to false. If
1255// a direct method is found, set \param anyDirect to true. Returns a direct
1256// method, if any.
1257static ObjCMethodDecl *LookupDirectMethodInGlobalPool(Sema &S, Selector Sel,
                                                    bool &onlyDirect,
                                                    bool &anyDirect) {
auto Iter = S.MethodPool.find(Sel);
if (Iter == S.MethodPool.end())
  return nullptr;

ObjCMethodDecl *DirectInstance = LookupDirectMethodInMethodList(
    S, Sel, Iter->second.first, onlyDirect, anyDirect);
ObjCMethodDecl *DirectClass = LookupDirectMethodInMethodList(
    S, Sel, Iter->second.second, onlyDirect, anyDirect);

return DirectInstance ? DirectInstance : DirectClass;
1270}

1272static ObjCMethodDecl *findMethodInCurrentClass(Sema &S, Selector Sel) {
auto *CurMD = S.getCurMethodDecl();
if (!CurMD)
  return nullptr;
ObjCInterfaceDecl *IFace = CurMD->getClassInterface();

// The language enforce that only one direct method is present in a given
// class, so we just need to find one method in the current class to know
// whether Sel is potentially direct in this context.
if (ObjCMethodDecl *MD = IFace->lookupMethod(Sel, /*isInstance=*/true))
  return MD;
if (ObjCMethodDecl *MD = IFace->lookupPrivateMethod(Sel, /*isInstance=*/true))
  return MD;
if (ObjCMethodDecl *MD = IFace->lookupMethod(Sel, /*isInstance=*/false))
  return MD;
if (ObjCMethodDecl *MD = IFace->lookupPrivateMethod(Sel, /*isInstance=*/false))
  return MD;

return nullptr;
1291}

1293ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
                                           SourceLocation AtLoc,
                                           SourceLocation SelLoc,
                                           SourceLocation LParenLoc,
                                           SourceLocation RParenLoc,
                                           bool WarnMultipleSelectors) {
ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
                           SourceRange(LParenLoc, RParenLoc));
if (!Method)
  Method = LookupFactoryMethodInGlobalPool(Sel,
                                        SourceRange(LParenLoc, RParenLoc));
if (!Method) {
  if (const ObjCMethodDecl *OM = SelectorsForTypoCorrection(Sel)) {
    Selector MatchedSel = OM->getSelector();
    SourceRange SelectorRange(LParenLoc.getLocWithOffset(1),
                              RParenLoc.getLocWithOffset(-1));
    Diag(SelLoc, diag::warn_undeclared_selector_with_typo)
      << Sel << MatchedSel
      << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());

  } else
      Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
} else {
  DiagnoseMismatchedSelectors(*this, AtLoc, Method, LParenLoc, RParenLoc,
                              WarnMultipleSelectors);

  bool onlyDirect = true;
  bool anyDirect = false;
  ObjCMethodDecl *GlobalDirectMethod =
      LookupDirectMethodInGlobalPool(*this, Sel, onlyDirect, anyDirect);

  if (onlyDirect) {
    Diag(AtLoc, diag::err_direct_selector_expression)
        << Method->getSelector();
    Diag(Method->getLocation(), diag::note_direct_method_declared_at)
        << Method->getDeclName();
  } else if (anyDirect) {
    // If we saw any direct methods, see if we see a direct member of the
    // current class. If so, the @selector will likely be used to refer to
    // this direct method.
    ObjCMethodDecl *LikelyTargetMethod = findMethodInCurrentClass(*this, Sel);
    if (LikelyTargetMethod && LikelyTargetMethod->isDirectMethod()) {
      Diag(AtLoc, diag::warn_potentially_direct_selector_expression) << Sel;
      Diag(LikelyTargetMethod->getLocation(),
           diag::note_direct_method_declared_at)
          << LikelyTargetMethod->getDeclName();
    } else if (!LikelyTargetMethod) {
      // Otherwise, emit the "strict" variant of this diagnostic, unless
      // LikelyTargetMethod is non-direct.
      Diag(AtLoc, diag::warn_strict_potentially_direct_selector_expression)
          << Sel;
      Diag(GlobalDirectMethod->getLocation(),
           diag::note_direct_method_declared_at)
          << GlobalDirectMethod->getDeclName();
    }
  }
}

if (Method &&
    Method->getImplementationControl() != ObjCMethodDecl::Optional &&
    !getSourceManager().isInSystemHeader(Method->getLocation()))
  ReferencedSelectors.insert(std::make_pair(Sel, AtLoc));

// In ARC, forbid the user from using @selector for
// retain/release/autorelease/dealloc/retainCount.
if (getLangOpts().ObjCAutoRefCount) {
  switch (Sel.getMethodFamily()) {
  case OMF_retain:
  case OMF_release:
  case OMF_autorelease:
  case OMF_retainCount:
  case OMF_dealloc:
    Diag(AtLoc, diag::err_arc_illegal_selector) <<
      Sel << SourceRange(LParenLoc, RParenLoc);
    break;

  case OMF_None:
  case OMF_alloc:
  case OMF_copy:
  case OMF_finalize:
  case OMF_init:
  case OMF_mutableCopy:
  case OMF_new:
  case OMF_self:
  case OMF_initialize:
  case OMF_performSelector:
    break;
  }
}
QualType Ty = Context.getObjCSelType();
return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
1384}

1386ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
                                           SourceLocation AtLoc,
                                           SourceLocation ProtoLoc,
                                           SourceLocation LParenLoc,
                                           SourceLocation ProtoIdLoc,
                                           SourceLocation RParenLoc) {
ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoIdLoc);
if (!PDecl) {
  Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
  return true;
}
if (PDecl->isNonRuntimeProtocol())
  Diag(ProtoLoc, diag::err_objc_non_runtime_protocol_in_protocol_expr)
      << PDecl;
if (!PDecl->hasDefinition()) {
  Diag(ProtoLoc, diag::err_atprotocol_protocol) << PDecl;
  Diag(PDecl->getLocation(), diag::note_entity_declared_at) << PDecl;
} else {
  PDecl = PDecl->getDefinition();
}

QualType Ty = Context.getObjCProtoType();
if (Ty.isNull())
  return true;
Ty = Context.getObjCObjectPointerType(Ty);
return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, ProtoIdLoc, RParenLoc);
1412}

1414/// Try to capture an implicit reference to 'self'.
1415ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
DeclContext *DC = getFunctionLevelDeclContext();

// If we're not in an ObjC method, error out.  Note that, unlike the
// C++ case, we don't require an instance method --- class methods
// still have a 'self', and we really do still need to capture it!
ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
if (!method)
  return nullptr;

tryCaptureVariable(method->getSelfDecl(), Loc);

return method;
1428}

1430static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
QualType origType = T;
if (auto nullability = AttributedType::stripOuterNullability(T)) {
  if (T == Context.getObjCInstanceType()) {
    return Context.getAttributedType(
             AttributedType::getNullabilityAttrKind(*nullability),
             Context.getObjCIdType(),
             Context.getObjCIdType());
  }

  return origType;
}

if (T == Context.getObjCInstanceType())
  return Context.getObjCIdType();

return origType;
1447}

1449/// Determine the result type of a message send based on the receiver type,
1450/// method, and the kind of message send.
1451///
1452/// This is the "base" result type, which will still need to be adjusted
1453/// to account for nullability.
1454static QualType getBaseMessageSendResultType(Sema &S,
                                           QualType ReceiverType,
                                           ObjCMethodDecl *Method,
                                           bool isClassMessage,
                                           bool isSuperMessage) {
assert(Method && "Must have a method")((void)0);
if (!Method->hasRelatedResultType())
  return Method->getSendResultType(ReceiverType);

ASTContext &Context = S.Context;

// Local function that transfers the nullability of the method's
// result type to the returned result.
auto transferNullability = [&](QualType type) -> QualType {
  // If the method's result type has nullability, extract it.
  if (auto nullability = Method->getSendResultType(ReceiverType)
                           ->getNullability(Context)){
    // Strip off any outer nullability sugar from the provided type.
    (void)AttributedType::stripOuterNullability(type);

    // Form a new attributed type using the method result type's nullability.
    return Context.getAttributedType(
             AttributedType::getNullabilityAttrKind(*nullability),
             type,
             type);
  }

  return type;
};

// If a method has a related return type:
//   - if the method found is an instance method, but the message send
//     was a class message send, T is the declared return type of the method
//     found
if (Method->isInstanceMethod() && isClassMessage)
  return stripObjCInstanceType(Context,
                               Method->getSendResultType(ReceiverType));

//   - if the receiver is super, T is a pointer to the class of the
//     enclosing method definition
if (isSuperMessage) {
  if (ObjCMethodDecl *CurMethod = S.getCurMethodDecl())
    if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface()) {
      return transferNullability(
               Context.getObjCObjectPointerType(
                 Context.getObjCInterfaceType(Class)));
    }
}

//   - if the receiver is the name of a class U, T is a pointer to U
if (ReceiverType->getAsObjCInterfaceType())
  return transferNullability(Context.getObjCObjectPointerType(ReceiverType));
//   - if the receiver is of type Class or qualified Class type,
//     T is the declared return type of the method.
if (ReceiverType->isObjCClassType() ||
    ReceiverType->isObjCQualifiedClassType())
  return stripObjCInstanceType(Context,
                               Method->getSendResultType(ReceiverType));

//   - if the receiver is id, qualified id, Class, or qualified Class, T
//     is the receiver type, otherwise
//   - T is the type of the receiver expression.
return transferNullability(ReceiverType);
1517}

1519QualType Sema::getMessageSendResultType(const Expr *Receiver,
                                      QualType ReceiverType,
                                      ObjCMethodDecl *Method,
                                      bool isClassMessage,
                                      bool isSuperMessage) {
// Produce the result type.
QualType resultType = getBaseMessageSendResultType(*this, ReceiverType,
                                                   Method,
                                                   isClassMessage,
                                                   isSuperMessage);

// If this is a class message, ignore the nullability of the receiver.
if (isClassMessage) {
  // In a class method, class messages to 'self' that return instancetype can
  // be typed as the current class.  We can safely do this in ARC because self
  // can't be reassigned, and we do it unsafely outside of ARC because in
  // practice people never reassign self in class methods and there's some
  // virtue in not being aggressively pedantic.
  if (Receiver && Receiver->isObjCSelfExpr()) {
    assert(ReceiverType->isObjCClassType() && "expected a Class self")((void)0);
    QualType T = Method->getSendResultType(ReceiverType);
    AttributedType::stripOuterNullability(T);
    if (T == Context.getObjCInstanceType()) {
      const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(
          cast<ImplicitParamDecl>(
              cast<DeclRefExpr>(Receiver->IgnoreParenImpCasts())->getDecl())
              ->getDeclContext());
      assert(MD->isClassMethod() && "expected a class method")((void)0);
      QualType NewResultType = Context.getObjCObjectPointerType(
          Context.getObjCInterfaceType(MD->getClassInterface()));
      if (auto Nullability = resultType->getNullability(Context))
        NewResultType = Context.getAttributedType(
            AttributedType::getNullabilityAttrKind(*Nullability),
            NewResultType, NewResultType);
      return NewResultType;
    }
  }
  return resultType;
}

// There is nothing left to do if the result type cannot have a nullability
// specifier.
if (!resultType->canHaveNullability())
  return resultType;

// Map the nullability of the result into a table index.
unsigned receiverNullabilityIdx = 0;
if (Optional<NullabilityKind> nullability =
        ReceiverType->getNullability(Context)) {
  if (*nullability == NullabilityKind::NullableResult)
    nullability = NullabilityKind::Nullable;
  receiverNullabilityIdx = 1 + static_cast<unsigned>(*nullability);
}

unsigned resultNullabilityIdx = 0;
if (Optional<NullabilityKind> nullability =
        resultType->getNullability(Context)) {
  if (*nullability == NullabilityKind::NullableResult)
    nullability = NullabilityKind::Nullable;
  resultNullabilityIdx = 1 + static_cast<unsigned>(*nullability);
}

// The table of nullability mappings, indexed by the receiver's nullability
// and then the result type's nullability.
static const uint8_t None = 0;
static const uint8_t NonNull = 1;
static const uint8_t Nullable = 2;
static const uint8_t Unspecified = 3;
static const uint8_t nullabilityMap[4][4] = {
  //                  None        NonNull       Nullable    Unspecified
  /* None */        { None,       None,         Nullable,   None },
  /* NonNull */     { None,       NonNull,      Nullable,   Unspecified },
  /* Nullable */    { Nullable,   Nullable,     Nullable,   Nullable },
  /* Unspecified */ { None,       Unspecified,  Nullable,   Unspecified }
};

unsigned newResultNullabilityIdx
  = nullabilityMap[receiverNullabilityIdx][resultNullabilityIdx];
if (newResultNullabilityIdx == resultNullabilityIdx)
  return resultType;

// Strip off the existing nullability. This removes as little type sugar as
// possible.
do {
  if (auto attributed = dyn_cast<AttributedType>(resultType.getTypePtr())) {
    resultType = attributed->getModifiedType();
  } else {
    resultType = resultType.getDesugaredType(Context);
  }
} while (resultType->getNullability(Context));

// Add nullability back if needed.
if (newResultNullabilityIdx > 0) {
  auto newNullability
    = static_cast<NullabilityKind>(newResultNullabilityIdx-1);
  return Context.getAttributedType(
           AttributedType::getNullabilityAttrKind(newNullability),
           resultType, resultType);
}

return resultType;
1620}

1622/// Look for an ObjC method whose result type exactly matches the given type.
1623static const ObjCMethodDecl *
1624findExplicitInstancetypeDeclarer(const ObjCMethodDecl *MD,
                               QualType instancetype) {
if (MD->getReturnType() == instancetype)
  return MD;

// For these purposes, a method in an @implementation overrides a
// declaration in the @interface.
if (const ObjCImplDecl *impl =
      dyn_cast<ObjCImplDecl>(MD->getDeclContext())) {
  const ObjCContainerDecl *iface;
  if (const ObjCCategoryImplDecl *catImpl =
        dyn_cast<ObjCCategoryImplDecl>(impl)) {
    iface = catImpl->getCategoryDecl();
  } else {
    iface = impl->getClassInterface();
  }

  const ObjCMethodDecl *ifaceMD =
    iface->getMethod(MD->getSelector(), MD->isInstanceMethod());
  if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype);
}

SmallVector<const ObjCMethodDecl *, 4> overrides;
MD->getOverriddenMethods(overrides);
for (unsigned i = 0, e = overrides.size(); i != e; ++i) {
  if (const ObjCMethodDecl *result =
        findExplicitInstancetypeDeclarer(overrides[i], instancetype))
    return result;
}

return nullptr;
1655}

1657void Sema::EmitRelatedResultTypeNoteForReturn(QualType destType) {
// Only complain if we're in an ObjC method and the required return
// type doesn't match the method's declared return type.
ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurContext);
if (!MD || !MD->hasRelatedResultType() ||
    Context.hasSameUnqualifiedType(destType, MD->getReturnType()))
  return;

// Look for a method overridden by this method which explicitly uses
// 'instancetype'.
if (const ObjCMethodDecl *overridden =
      findExplicitInstancetypeDeclarer(MD, Context.getObjCInstanceType())) {
  SourceRange range = overridden->getReturnTypeSourceRange();
  SourceLocation loc = range.getBegin();
  if (loc.isInvalid())
    loc = overridden->getLocation();
  Diag(loc, diag::note_related_result_type_explicit)
    << /*current method*/ 1 << range;
  return;
}

// Otherwise, if we have an interesting method family, note that.
// This should always trigger if the above didn't.
if (ObjCMethodFamily family = MD->getMethodFamily())
  Diag(MD->getLocation(), diag::note_related_result_type_family)
    << /*current method*/ 1
    << family;
1684}

1686void Sema::EmitRelatedResultTypeNote(const Expr *E) {
E = E->IgnoreParenImpCasts();
const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
if (!MsgSend)
  return;

const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
if (!Method)
  return;

if (!Method->hasRelatedResultType())
  return;

if (Context.hasSameUnqualifiedType(
        Method->getReturnType().getNonReferenceType(), MsgSend->getType()))
  return;

if (!Context.hasSameUnqualifiedType(Method->getReturnType(),
                                    Context.getObjCInstanceType()))
  return;

Diag(Method->getLocation(), diag::note_related_result_type_inferred)
  << Method->isInstanceMethod() << Method->getSelector()
  << MsgSend->getType();
1710}

1712bool Sema::CheckMessageArgumentTypes(
  const Expr *Receiver, QualType ReceiverType, MultiExprArg Args,
  Selector Sel, ArrayRef<SourceLocation> SelectorLocs, ObjCMethodDecl *Method,
  bool isClassMessage, bool isSuperMessage, SourceLocation lbrac,
  SourceLocation rbrac, SourceRange RecRange, QualType &ReturnType,
  ExprValueKind &VK) {
SourceLocation SelLoc;
if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
  SelLoc = SelectorLocs.front();
else
  SelLoc = lbrac;

if (!Method) {
  // Apply default argument promotion as for (C99 6.5.2.2p6).
  for (unsigned i = 0, e = Args.size(); i != e; i++) {
    if (Args[i]->isTypeDependent())
      continue;

    ExprResult result;
    if (getLangOpts().DebuggerSupport) {
      QualType paramTy; // ignored
      result = checkUnknownAnyArg(SelLoc, Args[i], paramTy);
    } else {
      result = DefaultArgumentPromotion(Args[i]);
    }
    if (result.isInvalid())
      return true;
    Args[i] = result.get();
  }

  unsigned DiagID;
  if (getLangOpts().ObjCAutoRefCount)
    DiagID = diag::err_arc_method_not_found;
  else
    DiagID = isClassMessage ? diag::warn_class_method_not_found
                            : diag::warn_inst_method_not_found;
  if (!getLangOpts().DebuggerSupport) {
    const ObjCMethodDecl *OMD = SelectorsForTypoCorrection(Sel, ReceiverType);
    if (OMD && !OMD->isInvalidDecl()) {
      if (getLangOpts().ObjCAutoRefCount)
        DiagID = diag::err_method_not_found_with_typo;
      else
        DiagID = isClassMessage ? diag::warn_class_method_not_found_with_typo
                                : diag::warn_instance_method_not_found_with_typo;
      Selector MatchedSel = OMD->getSelector();
      SourceRange SelectorRange(SelectorLocs.front(), SelectorLocs.back());
      if (MatchedSel.isUnarySelector())
        Diag(SelLoc, DiagID)
          << Sel<< isClassMessage << MatchedSel
          << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
      else
        Diag(SelLoc, DiagID) << Sel<< isClassMessage << MatchedSel;
    }
    else
      Diag(SelLoc, DiagID)
        << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
                                              SelectorLocs.back());
    // Find the class to which we are sending this message.
    if (auto *ObjPT = ReceiverType->getAs<ObjCObjectPointerType>()) {
      if (ObjCInterfaceDecl *ThisClass = ObjPT->getInterfaceDecl()) {
        Diag(ThisClass->getLocation(), diag::note_receiver_class_declared);
        if (!RecRange.isInvalid())
          if (ThisClass->lookupClassMethod(Sel))
            Diag(RecRange.getBegin(), diag::note_receiver_expr_here)
                << FixItHint::CreateReplacement(RecRange,
                                                ThisClass->getNameAsString());
      }
    }
  }

  // In debuggers, we want to use __unknown_anytype for these
  // results so that clients can cast them.
  if (getLangOpts().DebuggerSupport) {
    ReturnType = Context.UnknownAnyTy;
  } else {
    ReturnType = Context.getObjCIdType();
  }
  VK = VK_PRValue;
  return false;
}

ReturnType = getMessageSendResultType(Receiver, ReceiverType, Method,
                                      isClassMessage, isSuperMessage);
VK = Expr::getValueKindForType(Method->getReturnType());

unsigned NumNamedArgs = Sel.getNumArgs();
// Method might have more arguments than selector indicates. This is due
// to addition of c-style arguments in method.
if (Method->param_size() > Sel.getNumArgs())
  NumNamedArgs = Method->param_size();
// FIXME. This need be cleaned up.
if (Args.size() < NumNamedArgs) {
  Diag(SelLoc, diag::err_typecheck_call_too_few_args)
    << 2 << NumNamedArgs << static_cast<unsigned>(Args.size());
  return false;
}

// Compute the set of type arguments to be substituted into each parameter
// type.
Optional<ArrayRef<QualType>> typeArgs
  = ReceiverType->getObjCSubstitutions(Method->getDeclContext());
bool IsError = false;
for (unsigned i = 0; i < NumNamedArgs; i++) {
  // We can't do any type-checking on a type-dependent argument.
  if (Args[i]->isTypeDependent())
    continue;

  Expr *argExpr = Args[i];

  ParmVarDecl *param = Method->parameters()[i];
  assert(argExpr && "CheckMessageArgumentTypes(): missing expression")((void)0);

  if (param->hasAttr<NoEscapeAttr>() &&
      param->getType()->isBlockPointerType())
    if (auto *BE = dyn_cast<BlockExpr>(
            argExpr->IgnoreParenNoopCasts(Context)))
      BE->getBlockDecl()->setDoesNotEscape();

  // Strip the unbridged-cast placeholder expression off unless it's
  // a consumed argument.
  if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
      !param->hasAttr<CFConsumedAttr>())
    argExpr = stripARCUnbridgedCast(argExpr);

  // If the parameter is __unknown_anytype, infer its type
  // from the argument.
  if (param->getType() == Context.UnknownAnyTy) {
    QualType paramType;
    ExprResult argE = checkUnknownAnyArg(SelLoc, argExpr, paramType);
    if (argE.isInvalid()) {
      IsError = true;
    } else {
      Args[i] = argE.get();

      // Update the parameter type in-place.
      param->setType(paramType);
    }
    continue;
  }

  QualType origParamType = param->getType();
  QualType paramType = param->getType();
  if (typeArgs)
    paramType = paramType.substObjCTypeArgs(
                  Context,
                  *typeArgs,
                  ObjCSubstitutionContext::Parameter);

  if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
                          paramType,
                          diag::err_call_incomplete_argument, argExpr))
    return true;

  InitializedEntity Entity
    = InitializedEntity::InitializeParameter(Context, param, paramType);
  ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), argExpr);
  if (ArgE.isInvalid())
    IsError = true;
  else {
    Args[i] = ArgE.getAs<Expr>();

    // If we are type-erasing a block to a block-compatible
    // Objective-C pointer type, we may need to extend the lifetime
    // of the block object.
    if (typeArgs && Args[i]->isPRValue() && paramType->isBlockPointerType() &&
        Args[i]->getType()->isBlockPointerType() &&
        origParamType->isObjCObjectPointerType()) {
      ExprResult arg = Args[i];
      maybeExtendBlockObject(arg);
      Args[i] = arg.get();
    }
  }
}

// Promote additional arguments to variadic methods.
if (Method->isVariadic()) {
  for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
    if (Args[i]->isTypeDependent())
      continue;

    ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
                                                      nullptr);
    IsError |= Arg.isInvalid();
    Args[i] = Arg.get();
  }
} else {
  // Check for extra arguments to non-variadic methods.
  if (Args.size() != NumNamedArgs) {
    Diag(Args[NumNamedArgs]->getBeginLoc(),
         diag::err_typecheck_call_too_many_args)
        << 2 /*method*/ << NumNamedArgs << static_cast<unsigned>(Args.size())
        << Method->getSourceRange()
        << SourceRange(Args[NumNamedArgs]->getBeginLoc(),
                       Args.back()->getEndLoc());
  }
}

DiagnoseSentinelCalls(Method, SelLoc, Args);

// Do additional checkings on method.
IsError |= CheckObjCMethodCall(
    Method, SelLoc, makeArrayRef(Args.data(), Args.size()));

return IsError;
1916}

1918bool Sema::isSelfExpr(Expr *RExpr) {
// 'self' is objc 'self' in an objc method only.
ObjCMethodDecl *Method =
    dyn_cast_or_null<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
return isSelfExpr(RExpr, Method);
1923}

1925bool Sema::isSelfExpr(Expr *receiver, const ObjCMethodDecl *method) {
if (!method) return false;

receiver = receiver->IgnoreParenLValueCasts();
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
  if (DRE->getDecl() == method->getSelfDecl())
    return true;
return false;
1933}

1935/// LookupMethodInType - Look up a method in an ObjCObjectType.
1936ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
                                             bool isInstance) {
const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
if (ObjCInterfaceDecl *iface = objType->getInterface()) {
  // Look it up in the main interface (and categories, etc.)
  if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
    return method;

  // Okay, look for "private" methods declared in any
  // @implementations we've seen.
  if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
    return method;
}

// Check qualifiers.
for (const auto *I : objType->quals())
  if (ObjCMethodDecl *method = I->lookupMethod(sel, isInstance))
    return method;

return nullptr;
1956}

1958/// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1959/// list of a qualified objective pointer type.
1960ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
                                            const ObjCObjectPointerType *OPT,
                                            bool Instance)
1963{
ObjCMethodDecl *MD = nullptr;
for (const auto *PROTO : OPT->quals()) {
  if ((MD = PROTO->lookupMethod(Sel, Instance))) {
    return MD;
  }
}
return nullptr;
1971}

1973/// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1974/// objective C interface.  This is a property reference expression.
1975ExprResult Sema::
1976HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
                        Expr *BaseExpr, SourceLocation OpLoc,
                        DeclarationName MemberName,
                        SourceLocation MemberLoc,
                        SourceLocation SuperLoc, QualType SuperType,
                        bool Super) {
const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
ObjCInterfaceDecl *IFace = IFaceT->getDecl();

if (!MemberName.isIdentifier()) {
  Diag(MemberLoc, diag::err_invalid_property_name)
    << MemberName << QualType(OPT, 0);
  return ExprError();
}

IdentifierInfo *Member = MemberName.getAsIdentifierInfo();

SourceRange BaseRange = Super? SourceRange(SuperLoc)
                             : BaseExpr->getSourceRange();
if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
                        diag::err_property_not_found_forward_class,
                        MemberName, BaseRange))
  return ExprError();

if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(
        Member, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
  // Check whether we can reference this property.
  if (DiagnoseUseOfDecl(PD, MemberLoc))
    return ExprError();
  if (Super)
    return new (Context)
        ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
                            OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
  else
    return new (Context)
        ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
                            OK_ObjCProperty, MemberLoc, BaseExpr);
}
// Check protocols on qualified interfaces.
for (const auto *I : OPT->quals())
  if (ObjCPropertyDecl *PD = I->FindPropertyDeclaration(
          Member, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
    // Check whether we can reference this property.
    if (DiagnoseUseOfDecl(PD, MemberLoc))
      return ExprError();

    if (Super)
      return new (Context) ObjCPropertyRefExpr(
          PD, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc,
          SuperLoc, SuperType);
    else
      return new (Context)
          ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
                              OK_ObjCProperty, MemberLoc, BaseExpr);
  }
// If that failed, look for an "implicit" property by seeing if the nullary
// selector is implemented.

// FIXME: The logic for looking up nullary and unary selectors should be
// shared with the code in ActOnInstanceMessage.

Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);

// May be found in property's qualified list.
if (!Getter)
  Getter = LookupMethodInQualifiedType(Sel, OPT, true);

// If this reference is in an @implementation, check for 'private' methods.
if (!Getter)
  Getter = IFace->lookupPrivateMethod(Sel);

if (Getter) {
  // Check if we can reference this property.
  if (DiagnoseUseOfDecl(Getter, MemberLoc))
    return ExprError();
}
// If we found a getter then this may be a valid dot-reference, we
// will look for the matching setter, in case it is needed.
Selector SetterSel =
  SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
                                         PP.getSelectorTable(), Member);
ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);

// May be found in property's qualified list.
if (!Setter)
  Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);

if (!Setter) {
  // If this reference is in an @implementation, also check for 'private'
  // methods.
  Setter = IFace->lookupPrivateMethod(SetterSel);
}

if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
  return ExprError();

// Special warning if member name used in a property-dot for a setter accessor
// does not use a property with same name; e.g. obj.X = ... for a property with
// name 'x'.
if (Setter && Setter->isImplicit() && Setter->isPropertyAccessor() &&
    !IFace->FindPropertyDeclaration(
        Member, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
    if (const ObjCPropertyDecl *PDecl = Setter->findPropertyDecl()) {
      // Do not warn if user is using property-dot syntax to make call to
      // user named setter.
      if (!(PDecl->getPropertyAttributes() &
            ObjCPropertyAttribute::kind_setter))
        Diag(MemberLoc,
             diag::warn_property_access_suggest)
        << MemberName << QualType(OPT, 0) << PDecl->getName()
        << FixItHint::CreateReplacement(MemberLoc, PDecl->getName());
    }
}

if (Getter || Setter) {
  if (Super)
    return new (Context)
        ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
                            OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
  else
    return new (Context)
        ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
                            OK_ObjCProperty, MemberLoc, BaseExpr);

}

// Attempt to correct for typos in property names.
DeclFilterCCC<ObjCPropertyDecl> CCC{};
if (TypoCorrection Corrected = CorrectTypo(
        DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName,
        nullptr, nullptr, CCC, CTK_ErrorRecovery, IFace, false, OPT)) {
  DeclarationName TypoResult = Corrected.getCorrection();
  if (TypoResult.isIdentifier() &&
      TypoResult.getAsIdentifierInfo() == Member) {
    // There is no need to try the correction if it is the same.
    NamedDecl *ChosenDecl =
      Corrected.isKeyword() ? nullptr : Corrected.getFoundDecl();
    if (ChosenDecl && isa<ObjCPropertyDecl>(ChosenDecl))
      if (cast<ObjCPropertyDecl>(ChosenDecl)->isClassProperty()) {
        // This is a class property, we should not use the instance to
        // access it.
        Diag(MemberLoc, diag::err_class_property_found) << MemberName
        << OPT->getInterfaceDecl()->getName()
        << FixItHint::CreateReplacement(BaseExpr->getSourceRange(),
                                        OPT->getInterfaceDecl()->getName());
        return ExprError();
      }
  } else {
    diagnoseTypo(Corrected, PDiag(diag::err_property_not_found_suggest)
                              << MemberName << QualType(OPT, 0));
    return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
                                     TypoResult, MemberLoc,
                                     SuperLoc, SuperType, Super);
  }
}
ObjCInterfaceDecl *ClassDeclared;
if (ObjCIvarDecl *Ivar =
    IFace->lookupInstanceVariable(Member, ClassDeclared)) {
  QualType T = Ivar->getType();
  if (const ObjCObjectPointerType * OBJPT =
      T->getAsObjCInterfacePointerType()) {
    if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
                            diag::err_property_not_as_forward_class,
                            MemberName, BaseExpr))
      return ExprError();
  }
  Diag(MemberLoc,
       diag::err_ivar_access_using_property_syntax_suggest)
  << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
  << FixItHint::CreateReplacement(OpLoc, "->");
  return ExprError();
}

Diag(MemberLoc, diag::err_property_not_found)
  << MemberName << QualType(OPT, 0);
if (Setter)
  Diag(Setter->getLocation(), diag::note_getter_unavailable)
        << MemberName << BaseExpr->getSourceRange();
return ExprError();
2156}

2158ExprResult Sema::
2159ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
                        IdentifierInfo &propertyName,
                        SourceLocation receiverNameLoc,
                        SourceLocation propertyNameLoc) {

IdentifierInfo *receiverNamePtr = &receiverName;
ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
                                                receiverNameLoc);

QualType SuperType;
if (!IFace) {
  // If the "receiver" is 'super' in a method, handle it as an expression-like
  // property reference.
  if (receiverNamePtr->isStr("super")) {
    if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
      if (auto classDecl = CurMethod->getClassInterface()) {
        SuperType = QualType(classDecl->getSuperClassType(), 0);
        if (CurMethod->isInstanceMethod()) {
          if (SuperType.isNull()) {
            // The current class does not have a superclass.
            Diag(receiverNameLoc, diag::err_root_class_cannot_use_super)
              << CurMethod->getClassInterface()->getIdentifier();
            return ExprError();
          }
          QualType T = Context.getObjCObjectPointerType(SuperType);

          return HandleExprPropertyRefExpr(T->castAs<ObjCObjectPointerType>(),
                                           /*BaseExpr*/nullptr,
                                           SourceLocation()/*OpLoc*/,
                                           &propertyName,
                                           propertyNameLoc,
                                           receiverNameLoc, T, true);
        }

        // Otherwise, if this is a class method, try dispatching to our
        // superclass.
        IFace = CurMethod->getClassInterface()->getSuperClass();
      }
    }
  }

  if (!IFace) {
    Diag(receiverNameLoc, diag::err_expected_either) << tok::identifier
                                                     << tok::l_paren;
    return ExprError();
  }
}

Selector GetterSel;
Selector SetterSel;
if (auto PD = IFace->FindPropertyDeclaration(
        &propertyName, ObjCPropertyQueryKind::OBJC_PR_query_class)) {
  GetterSel = PD->getGetterName();
  SetterSel = PD->getSetterName();
} else {
  GetterSel = PP.getSelectorTable().getNullarySelector(&propertyName);
  SetterSel = SelectorTable::constructSetterSelector(
      PP.getIdentifierTable(), PP.getSelectorTable(), &propertyName);
}

// Search for a declared property first.
ObjCMethodDecl *Getter = IFace->lookupClassMethod(GetterSel);

// If this reference is in an @implementation, check for 'private' methods.
if (!Getter)
  Getter = IFace->lookupPrivateClassMethod(GetterSel);

if (Getter) {
  // FIXME: refactor/share with ActOnMemberReference().
  // Check if we can reference this property.
  if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
    return ExprError();
}

// Look for the matching setter, in case it is needed.
ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
if (!Setter) {
  // If this reference is in an @implementation, also check for 'private'
  // methods.
  Setter = IFace->lookupPrivateClassMethod(SetterSel);
}
// Look through local category implementations associated with the class.
if (!Setter)
  Setter = IFace->getCategoryClassMethod(SetterSel);

if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
  return ExprError();

if (Getter || Setter) {
  if (!SuperType.isNull())
    return new (Context)
        ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
                            OK_ObjCProperty, propertyNameLoc, receiverNameLoc,
                            SuperType);

  return new (Context) ObjCPropertyRefExpr(
      Getter, Setter, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty,
      propertyNameLoc, receiverNameLoc, IFace);
}
return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
                   << &propertyName << Context.getObjCInterfaceType(IFace));
2260}

2262namespace {

2264class ObjCInterfaceOrSuperCCC final : public CorrectionCandidateCallback {
public:
ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
  // Determine whether "super" is acceptable in the current context.
  if (Method && Method->getClassInterface())
    WantObjCSuper = Method->getClassInterface()->getSuperClass();
}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
      candidate.isKeyword("super");
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<ObjCInterfaceOrSuperCCC>(*this);
}
2280};

2282} // end anonymous namespace

2284Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
                                             IdentifierInfo *Name,
                                             SourceLocation NameLoc,
                                             bool IsSuper,
                                             bool HasTrailingDot,
                                             ParsedType &ReceiverType) {
ReceiverType = nullptr;

// If the identifier is "super" and there is no trailing dot, we're
// messaging super. If the identifier is "super" and there is a
// trailing dot, it's an instance message.
if (IsSuper && S->isInObjcMethodScope())
  return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;

LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
LookupName(Result, S);

switch (Result.getResultKind()) {
case LookupResult::NotFound:
  // Normal name lookup didn't find anything. If we're in an
  // Objective-C method, look for ivars. If we find one, we're done!
  // FIXME: This is a hack. Ivar lookup should be part of normal
  // lookup.
  if (ObjCMethodDecl *Method = getCurMethodDecl()) {
    if (!Method->getClassInterface()) {
      // Fall back: let the parser try to parse it as an instance message.
      return ObjCInstanceMessage;
    }

    ObjCInterfaceDecl *ClassDeclared;
    if (Method->getClassInterface()->lookupInstanceVariable(Name,
                                                            ClassDeclared))
      return ObjCInstanceMessage;
  }

  // Break out; we'll perform typo correction below.
  break;

case LookupResult::NotFoundInCurrentInstantiation:
case LookupResult::FoundOverloaded:
case LookupResult::FoundUnresolvedValue:
case LookupResult::Ambiguous:
  Result.suppressDiagnostics();
  return ObjCInstanceMessage;

case LookupResult::Found: {
  // If the identifier is a class or not, and there is a trailing dot,
  // it's an instance message.
  if (HasTrailingDot)
    return ObjCInstanceMessage;
  // We found something. If it's a type, then we have a class
  // message. Otherwise, it's an instance message.
  NamedDecl *ND = Result.getFoundDecl();
  QualType T;
  if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
    T = Context.getObjCInterfaceType(Class);
  else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND)) {
    T = Context.getTypeDeclType(Type);
    DiagnoseUseOfDecl(Type, NameLoc);
  }
  else
    return ObjCInstanceMessage;

  //  We have a class message, and T is the type we're
  //  messaging. Build source-location information for it.
  TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
  ReceiverType = CreateParsedType(T, TSInfo);
  return ObjCClassMessage;
}
}

ObjCInterfaceOrSuperCCC CCC(getCurMethodDecl());
if (TypoCorrection Corrected = CorrectTypo(
        Result.getLookupNameInfo(), Result.getLookupKind(), S, nullptr, CCC,
        CTK_ErrorRecovery, nullptr, false, nullptr, false)) {
  if (Corrected.isKeyword()) {
    // If we've found the keyword "super" (the only keyword that would be
    // returned by CorrectTypo), this is a send to super.
    diagnoseTypo(Corrected,
                 PDiag(diag::err_unknown_receiver_suggest) << Name);
    return ObjCSuperMessage;
  } else if (ObjCInterfaceDecl *Class =
                 Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
    // If we found a declaration, correct when it refers to an Objective-C
    // class.
    diagnoseTypo(Corrected,
                 PDiag(diag::err_unknown_receiver_suggest) << Name);
    QualType T = Context.getObjCInterfaceType(Class);
    TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
    ReceiverType = CreateParsedType(T, TSInfo);
    return ObjCClassMessage;
  }
}

// Fall back: let the parser try to parse it as an instance message.
return ObjCInstanceMessage;
2380}

2382ExprResult Sema::ActOnSuperMessage(Scope *S,
                                 SourceLocation SuperLoc,
                                 Selector Sel,
                                 SourceLocation LBracLoc,
                                 ArrayRef<SourceLocation> SelectorLocs,
                                 SourceLocation RBracLoc,
                                 MultiExprArg Args) {
// Determine whether we are inside a method or not.
ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
if (!Method0.1
'Method' is non-null
1
'Method' is non-null
) {
1
Taking false branch→
  Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
  return ExprError();
}

ObjCInterfaceDecl *Class = Method->getClassInterface();
if (!Class) {
2
←
Assuming 'Class' is non-null→
3
←
Taking false branch→
  Diag(SuperLoc, diag::err_no_super_class_message)
    << Method->getDeclName();
  return ExprError();
}

QualType SuperTy(Class->getSuperClassType(), 0);
if (SuperTy.isNull()) {
4
←
Taking false branch→
  // The current class does not have a superclass.
  Diag(SuperLoc, diag::err_root_class_cannot_use_super)
    << Class->getIdentifier();
  return ExprError();
}

// We are in a method whose class has a superclass, so 'super'
// is acting as a keyword.
if (Method->getSelector() == Sel)
5
←
Taking false branch→
  getCurFunction()->ObjCShouldCallSuper = false;

if (Method->isInstanceMethod()) {
6
←
Assuming the condition is false→
7
←
Taking false branch→
  // Since we are in an instance method, this is an instance
  // message to the superclass instance.
  SuperTy = Context.getObjCObjectPointerType(SuperTy);
  return BuildInstanceMessage(nullptr, SuperTy, SuperLoc,
                              Sel, /*Method=*/nullptr,
                              LBracLoc, SelectorLocs, RBracLoc, Args);
}

// Since we are in a class method, this is a class message to
// the superclass.
return BuildClassMessage(/*ReceiverTypeInfo=*/nullptr,
8
←
Passing null pointer value via 1st parameter 'ReceiverTypeInfo'→
9
←
Calling 'Sema::BuildClassMessage'→
                         SuperTy,
                         SuperLoc, Sel, /*Method=*/nullptr,
                         LBracLoc, SelectorLocs, RBracLoc, Args);
2431}

2433ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
                                         bool isSuperReceiver,
                                         SourceLocation Loc,
                                         Selector Sel,
                                         ObjCMethodDecl *Method,
                                         MultiExprArg Args) {
TypeSourceInfo *receiverTypeInfo = nullptr;
if (!ReceiverType.isNull())
  receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);

return BuildClassMessage(receiverTypeInfo, ReceiverType,
                        /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
                         Sel, Method, Loc, Loc, Loc, Args,
                         /*isImplicit=*/true);
2447}

2449static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
                             unsigned DiagID,
                             bool (*refactor)(const ObjCMessageExpr *,
                                            const NSAPI &, edit::Commit &)) {
SourceLocation MsgLoc = Msg->getExprLoc();
if (S.Diags.isIgnored(DiagID, MsgLoc))
  return;

SourceManager &SM = S.SourceMgr;
edit::Commit ECommit(SM, S.LangOpts);
if (refactor(Msg,*S.NSAPIObj, ECommit)) {
  auto Builder = S.Diag(MsgLoc, DiagID)
                 << Msg->getSelector() << Msg->getSourceRange();
  // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
  if (!ECommit.isCommitable())
    return;
  for (edit::Commit::edit_iterator
         I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
    const edit::Commit::Edit &Edit = *I;
    switch (Edit.Kind) {
    case edit::Commit::Act_Insert:
      Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
                                                      Edit.Text,
                                                      Edit.BeforePrev));
      break;
    case edit::Commit::Act_InsertFromRange:
      Builder.AddFixItHint(
          FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
                                              Edit.getInsertFromRange(SM),
                                              Edit.BeforePrev));
      break;
    case edit::Commit::Act_Remove:
      Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
      break;
    }
  }
}
2486}

2488static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
                   edit::rewriteObjCRedundantCallWithLiteral);
2491}

2493static void checkFoundationAPI(Sema &S, SourceLocation Loc,
                             const ObjCMethodDecl *Method,
                             ArrayRef<Expr *> Args, QualType ReceiverType,
                             bool IsClassObjectCall) {
// Check if this is a performSelector method that uses a selector that returns
// a record or a vector type.
if (Method->getSelector().getMethodFamily() != OMF_performSelector ||
    Args.empty())
  return;
const auto *SE = dyn_cast<ObjCSelectorExpr>(Args[0]->IgnoreParens());
if (!SE)
  return;
ObjCMethodDecl *ImpliedMethod;
if (!IsClassObjectCall) {
  const auto *OPT = ReceiverType->getAs<ObjCObjectPointerType>();
  if (!OPT || !OPT->getInterfaceDecl())
    return;
  ImpliedMethod =
      OPT->getInterfaceDecl()->lookupInstanceMethod(SE->getSelector());
  if (!ImpliedMethod)
    ImpliedMethod =
        OPT->getInterfaceDecl()->lookupPrivateMethod(SE->getSelector());
} else {
  const auto *IT = ReceiverType->getAs<ObjCInterfaceType>();
  if (!IT)
    return;
  ImpliedMethod = IT->getDecl()->lookupClassMethod(SE->getSelector());
  if (!ImpliedMethod)
    ImpliedMethod =
        IT->getDecl()->lookupPrivateClassMethod(SE->getSelector());
}
if (!ImpliedMethod)
  return;
QualType Ret = ImpliedMethod->getReturnType();
if (Ret->isRecordType() || Ret->isVectorType() || Ret->isExtVectorType()) {
  S.Diag(Loc, diag::warn_objc_unsafe_perform_selector)
      << Method->getSelector()
      << (!Ret->isRecordType()
              ? /*Vector*/ 2
              : Ret->isUnionType() ? /*Union*/ 1 : /*Struct*/ 0);
  S.Diag(ImpliedMethod->getBeginLoc(),
         diag::note_objc_unsafe_perform_selector_method_declared_here)
      << ImpliedMethod->getSelector() << Ret;
}
2537}

2539/// Diagnose use of %s directive in an NSString which is being passed
2540/// as formatting string to formatting method.
2541static void
2542DiagnoseCStringFormatDirectiveInObjCAPI(Sema &S,
                                      ObjCMethodDecl *Method,
                                      Selector Sel,
                                      Expr **Args, unsigned NumArgs) {
unsigned Idx = 0;
bool Format = false;
ObjCStringFormatFamily SFFamily = Sel.getStringFormatFamily();
if (SFFamily == ObjCStringFormatFamily::SFF_NSString) {
  Idx = 0;
  Format = true;
}
else if (Method) {
  for (const auto *I : Method->specific_attrs<FormatAttr>()) {
    if (S.GetFormatNSStringIdx(I, Idx)) {
      Format = true;
      break;
    }
  }
}
if (!Format || NumArgs <= Idx)
  return;

Expr *FormatExpr = Args[Idx];
if (ObjCStringLiteral *OSL =
    dyn_cast<ObjCStringLiteral>(FormatExpr->IgnoreParenImpCasts())) {
  StringLiteral *FormatString = OSL->getString();
  if (S.FormatStringHasSArg(FormatString)) {
    S.Diag(FormatExpr->getExprLoc(), diag::warn_objc_cdirective_format_string)
      << "%s" << 0 << 0;
    if (Method)
      S.Diag(Method->getLocation(), diag::note_method_declared_at)
        << Method->getDeclName();
  }
}
2576}

2578/// Build an Objective-C class message expression.
2579///
2580/// This routine takes care of both normal class messages and
2581/// class messages to the superclass.
2582///
2583/// \param ReceiverTypeInfo Type source information that describes the
2584/// receiver of this message. This may be NULL, in which case we are
2585/// sending to the superclass and \p SuperLoc must be a valid source
2586/// location.

2588/// \param ReceiverType The type of the object receiving the
2589/// message. When \p ReceiverTypeInfo is non-NULL, this is the same
2590/// type as that refers to. For a superclass send, this is the type of
2591/// the superclass.
2592///
2593/// \param SuperLoc The location of the "super" keyword in a
2594/// superclass message.
2595///
2596/// \param Sel The selector to which the message is being sent.
2597///
2598/// \param Method The method that this class message is invoking, if
2599/// already known.
2600///
2601/// \param LBracLoc The location of the opening square bracket ']'.
2602///
2603/// \param RBracLoc The location of the closing square bracket ']'.
2604///
2605/// \param ArgsIn The message arguments.
2606ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
                                 QualType ReceiverType,
                                 SourceLocation SuperLoc,
                                 Selector Sel,
                                 ObjCMethodDecl *Method,
                                 SourceLocation LBracLoc,
                                 ArrayRef<SourceLocation> SelectorLocs,
                                 SourceLocation RBracLoc,
                                 MultiExprArg ArgsIn,
                                 bool isImplicit) {
SourceLocation Loc = SuperLoc.isValid()? SuperLoc
10
←
Calling 'SourceLocation::isValid'→
13
←
Returning from 'SourceLocation::isValid'→
14
←
'?' condition is false→
  : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
15
←
Called C++ object pointer is null
if (LBracLoc.isInvalid()) {
  Diag(Loc, diag::err_missing_open_square_message_send)
    << FixItHint::CreateInsertion(Loc, "[");
  LBracLoc = Loc;
}
ArrayRef<SourceLocation> SelectorSlotLocs;
if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
  SelectorSlotLocs = SelectorLocs;
else
  SelectorSlotLocs = Loc;
SourceLocation SelLoc = SelectorSlotLocs.front();

if (ReceiverType->isDependentType()) {
  // If the receiver type is dependent, we can't type-check anything
  // at this point. Build a dependent expression.
  unsigned NumArgs = ArgsIn.size();
  Expr **Args = ArgsIn.data();
  assert(SuperLoc.isInvalid() && "Message to super with dependent type")((void)0);
  return ObjCMessageExpr::Create(
      Context, ReceiverType, VK_PRValue, LBracLoc, ReceiverTypeInfo, Sel,
      SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs), RBracLoc,
      isImplicit);
}

// Find the class to which we are sending this message.
ObjCInterfaceDecl *Class = nullptr;
const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
if (!ClassType || !(Class = ClassType->getInterface())) {
  Diag(Loc, diag::err_invalid_receiver_class_message)
    << ReceiverType;
  return ExprError();
}
assert(Class && "We don't know which class we're messaging?")((void)0);
// objc++ diagnoses during typename annotation.
if (!getLangOpts().CPlusPlus)
  (void)DiagnoseUseOfDecl(Class, SelectorSlotLocs);
// Find the method we are messaging.
if (!Method) {
  SourceRange TypeRange
    = SuperLoc.isValid()? SourceRange(SuperLoc)
                        : ReceiverTypeInfo->getTypeLoc().getSourceRange();
  if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
                          (getLangOpts().ObjCAutoRefCount
                             ? diag::err_arc_receiver_forward_class
                             : diag::warn_receiver_forward_class),
                          TypeRange)) {
    // A forward class used in messaging is treated as a 'Class'
    Method = LookupFactoryMethodInGlobalPool(Sel,
                                             SourceRange(LBracLoc, RBracLoc));
    if (Method && !getLangOpts().ObjCAutoRefCount)
      Diag(Method->getLocation(), diag::note_method_sent_forward_class)
        << Method->getDeclName();
  }
  if (!Method)
    Method = Class->lookupClassMethod(Sel);

  // If we have an implementation in scope, check "private" methods.
  if (!Method)
    Method = Class->lookupPrivateClassMethod(Sel);

  if (Method && DiagnoseUseOfDecl(Method, SelectorSlotLocs,
                                  nullptr, false, false, Class))
    return ExprError();
}

// Check the argument types and determine the result type.
QualType ReturnType;
ExprValueKind VK = VK_PRValue;

unsigned NumArgs = ArgsIn.size();
Expr **Args = ArgsIn.data();
if (CheckMessageArgumentTypes(/*Receiver=*/nullptr, ReceiverType,
                              MultiExprArg(Args, NumArgs), Sel, SelectorLocs,
                              Method, true, SuperLoc.isValid(), LBracLoc,
                              RBracLoc, SourceRange(), ReturnType, VK))
  return ExprError();

if (Method && !Method->getReturnType()->isVoidType() &&
    RequireCompleteType(LBracLoc, Method->getReturnType(),
                        diag::err_illegal_message_expr_incomplete_type))
  return ExprError();

if (Method && Method->isDirectMethod() && SuperLoc.isValid()) {
  Diag(SuperLoc, diag::err_messaging_super_with_direct_method)
      << FixItHint::CreateReplacement(
             SuperLoc, getLangOpts().ObjCAutoRefCount
                           ? "self"
                           : Method->getClassInterface()->getName());
  Diag(Method->getLocation(), diag::note_direct_method_declared_at)
      << Method->getDeclName();
}

// Warn about explicit call of +initialize on its own class. But not on 'super'.
if (Method && Method->getMethodFamily() == OMF_initialize) {
  if (!SuperLoc.isValid()) {
    const ObjCInterfaceDecl *ID =
      dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext());
    if (ID == Class) {
      Diag(Loc, diag::warn_direct_initialize_call);
      Diag(Method->getLocation(), diag::note_method_declared_at)
        << Method->getDeclName();
    }
  }
  else if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
    // [super initialize] is allowed only within an +initialize implementation
    if (CurMeth->getMethodFamily() != OMF_initialize) {
      Diag(Loc, diag::warn_direct_super_initialize_call);
      Diag(Method->getLocation(), diag::note_method_declared_at)
        << Method->getDeclName();
      Diag(CurMeth->getLocation(), diag::note_method_declared_at)
      << CurMeth->getDeclName();
    }
  }
}

DiagnoseCStringFormatDirectiveInObjCAPI(*this, Method, Sel, Args, NumArgs);

// Construct the appropriate ObjCMessageExpr.
ObjCMessageExpr *Result;
if (SuperLoc.isValid())
  Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
                                   SuperLoc, /*IsInstanceSuper=*/false,
                                   ReceiverType, Sel, SelectorLocs,
                                   Method, makeArrayRef(Args, NumArgs),
                                   RBracLoc, isImplicit);
else {
  Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
                                   ReceiverTypeInfo, Sel, SelectorLocs,
                                   Method, makeArrayRef(Args, NumArgs),
                                   RBracLoc, isImplicit);
  if (!isImplicit)
    checkCocoaAPI(*this, Result);
}
if (Method)
  checkFoundationAPI(*this, SelLoc, Method, makeArrayRef(Args, NumArgs),
                     ReceiverType, /*IsClassObjectCall=*/true);
return MaybeBindToTemporary(Result);
2755}

2757// ActOnClassMessage - used for both unary and keyword messages.
2758// ArgExprs is optional - if it is present, the number of expressions
2759// is obtained from Sel.getNumArgs().
2760ExprResult Sema::ActOnClassMessage(Scope *S,
                                 ParsedType Receiver,
                                 Selector Sel,
                                 SourceLocation LBracLoc,
                                 ArrayRef<SourceLocation> SelectorLocs,
                                 SourceLocation RBracLoc,
                                 MultiExprArg Args) {
TypeSourceInfo *ReceiverTypeInfo;
QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
if (ReceiverType.isNull())
  return ExprError();

if (!ReceiverTypeInfo)
  ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);

return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
                         /*SuperLoc=*/SourceLocation(), Sel,
                         /*Method=*/nullptr, LBracLoc, SelectorLocs, RBracLoc,
                         Args);
2779}

2781ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
                                            QualType ReceiverType,
                                            SourceLocation Loc,
                                            Selector Sel,
                                            ObjCMethodDecl *Method,
                                            MultiExprArg Args) {
return BuildInstanceMessage(Receiver, ReceiverType,
                            /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
                            Sel, Method, Loc, Loc, Loc, Args,
                            /*isImplicit=*/true);
2791}

2793static bool isMethodDeclaredInRootProtocol(Sema &S, const ObjCMethodDecl *M) {
if (!S.NSAPIObj)
  return false;
const auto *Protocol = dyn_cast<ObjCProtocolDecl>(M->getDeclContext());
if (!Protocol)
  return false;
const IdentifierInfo *II = S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject);
if (const auto *RootClass = dyn_cast_or_null<ObjCInterfaceDecl>(
        S.LookupSingleName(S.TUScope, II, Protocol->getBeginLoc(),
                           Sema::LookupOrdinaryName))) {
  for (const ObjCProtocolDecl *P : RootClass->all_referenced_protocols()) {
    if (P->getCanonicalDecl() == Protocol->getCanonicalDecl())
      return true;
  }
}
return false;
2809}

2811/// Build an Objective-C instance message expression.
2812///
2813/// This routine takes care of both normal instance messages and
2814/// instance messages to the superclass instance.
2815///
2816/// \param Receiver The expression that computes the object that will
2817/// receive this message. This may be empty, in which case we are
2818/// sending to the superclass instance and \p SuperLoc must be a valid
2819/// source location.
2820///
2821/// \param ReceiverType The (static) type of the object receiving the
2822/// message. When a \p Receiver expression is provided, this is the
2823/// same type as that expression. For a superclass instance send, this
2824/// is a pointer to the type of the superclass.
2825///
2826/// \param SuperLoc The location of the "super" keyword in a
2827/// superclass instance message.
2828///
2829/// \param Sel The selector to which the message is being sent.
2830///
2831/// \param Method The method that this instance message is invoking, if
2832/// already known.
2833///
2834/// \param LBracLoc The location of the opening square bracket ']'.
2835///
2836/// \param RBracLoc The location of the closing square bracket ']'.
2837///
2838/// \param ArgsIn The message arguments.
2839ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
                                    QualType ReceiverType,
                                    SourceLocation SuperLoc,
                                    Selector Sel,
                                    ObjCMethodDecl *Method,
                                    SourceLocation LBracLoc,
                                    ArrayRef<SourceLocation> SelectorLocs,
                                    SourceLocation RBracLoc,
                                    MultiExprArg ArgsIn,
                                    bool isImplicit) {
assert((Receiver || SuperLoc.isValid()) && "If the Receiver is null, the "((void)0)
                                           "SuperLoc must be valid so we can "((void)0)
                                           "use it instead.")((void)0);

// The location of the receiver.
SourceLocation Loc = SuperLoc.isValid() ? SuperLoc : Receiver->getBeginLoc();
SourceRange RecRange =
    SuperLoc.isValid()? SuperLoc : Receiver->getSourceRange();
ArrayRef<SourceLocation> SelectorSlotLocs;
if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
  SelectorSlotLocs = SelectorLocs;
else
  SelectorSlotLocs = Loc;
SourceLocation SelLoc = SelectorSlotLocs.front();

if (LBracLoc.isInvalid()) {
  Diag(Loc, diag::err_missing_open_square_message_send)
    << FixItHint::CreateInsertion(Loc, "[");
  LBracLoc = Loc;
}

// If we have a receiver expression, perform appropriate promotions
// and determine receiver type.
if (Receiver) {
  if (Receiver->hasPlaceholderType()) {
    ExprResult Result;
    if (Receiver->getType() == Context.UnknownAnyTy)
      Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
    else
      Result = CheckPlaceholderExpr(Receiver);
    if (Result.isInvalid()) return ExprError();
    Receiver = Result.get();
  }

  if (Receiver->isTypeDependent()) {
    // If the receiver is type-dependent, we can't type-check anything
    // at this point. Build a dependent expression.
    unsigned NumArgs = ArgsIn.size();
    Expr **Args = ArgsIn.data();
    assert(SuperLoc.isInvalid() && "Message to super with dependent type")((void)0);
    return ObjCMessageExpr::Create(
        Context, Context.DependentTy, VK_PRValue, LBracLoc, Receiver, Sel,
        SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs),
        RBracLoc, isImplicit);
  }

  // If necessary, apply function/array conversion to the receiver.
  // C99 6.7.5.3p[7,8].
  ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
  if (Result.isInvalid())
    return ExprError();
  Receiver = Result.get();
  ReceiverType = Receiver->getType();

  // If the receiver is an ObjC pointer, a block pointer, or an
  // __attribute__((NSObject)) pointer, we don't need to do any
  // special conversion in order to look up a receiver.
  if (ReceiverType->isObjCRetainableType()) {
    // do nothing
  } else if (!getLangOpts().ObjCAutoRefCount &&
             !Context.getObjCIdType().isNull() &&
             (ReceiverType->isPointerType() ||
              ReceiverType->isIntegerType())) {
    // Implicitly convert integers and pointers to 'id' but emit a warning.
    // But not in ARC.
    Diag(Loc, diag::warn_bad_receiver_type) << ReceiverType << RecRange;
    if (ReceiverType->isPointerType()) {
      Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
                                   CK_CPointerToObjCPointerCast).get();
    } else {
      // TODO: specialized warning on null receivers?
      bool IsNull = Receiver->isNullPointerConstant(Context,
                                            Expr::NPC_ValueDependentIsNull);
      CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
      Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
                                   Kind).get();
    }
    ReceiverType = Receiver->getType();
  } else if (getLangOpts().CPlusPlus) {
    // The receiver must be a complete type.
    if (RequireCompleteType(Loc, Receiver->getType(),
                            diag::err_incomplete_receiver_type))
      return ExprError();

    ExprResult result = PerformContextuallyConvertToObjCPointer(Receiver);
    if (result.isUsable()) {
      Receiver = result.get();
      ReceiverType = Receiver->getType();
    }
  }
}

// There's a somewhat weird interaction here where we assume that we
// won't actually have a method unless we also don't need to do some
// of the more detailed type-checking on the receiver.

if (!Method) {
  // Handle messages to id and __kindof types (where we use the
  // global method pool).
  const ObjCObjectType *typeBound = nullptr;
  bool receiverIsIdLike = ReceiverType->isObjCIdOrObjectKindOfType(Context,
                                                                   typeBound);
  if (receiverIsIdLike || ReceiverType->isBlockPointerType() ||
      (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
    SmallVector<ObjCMethodDecl*, 4> Methods;
    // If we have a type bound, further filter the methods.
    CollectMultipleMethodsInGlobalPool(Sel, Methods, true/*InstanceFirst*/,
                                       true/*CheckTheOther*/, typeBound);
    if (!Methods.empty()) {
      // We choose the first method as the initial candidate, then try to
      // select a better one.
      Method = Methods[0];

      if (ObjCMethodDecl *BestMethod =
          SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod(), Methods))
        Method = BestMethod;

      if (!AreMultipleMethodsInGlobalPool(Sel, Method,
                                          SourceRange(LBracLoc, RBracLoc),
                                          receiverIsIdLike, Methods))
        DiagnoseUseOfDecl(Method, SelectorSlotLocs);
    }
  } else if (ReceiverType->isObjCClassOrClassKindOfType() ||
             ReceiverType->isObjCQualifiedClassType()) {
    // Handle messages to Class.
    // We allow sending a message to a qualified Class ("Class<foo>"), which
    // is ok as long as one of the protocols implements the selector (if not,
    // warn).
    if (!ReceiverType->isObjCClassOrClassKindOfType()) {
      const ObjCObjectPointerType *QClassTy
        = ReceiverType->getAsObjCQualifiedClassType();
      // Search protocols for class methods.
      Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
      if (!Method) {
        Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
        // warn if instance method found for a Class message.
        if (Method && !isMethodDeclaredInRootProtocol(*this, Method)) {
          Diag(SelLoc, diag::warn_instance_method_on_class_found)
            << Method->getSelector() << Sel;
          Diag(Method->getLocation(), diag::note_method_declared_at)
            << Method->getDeclName();
        }
      }
    } else {
      if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
        if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
          // As a guess, try looking for the method in the current interface.
          // This very well may not produce the "right" method.

          // First check the public methods in the class interface.
          Method = ClassDecl->lookupClassMethod(Sel);

          if (!Method)
            Method = ClassDecl->lookupPrivateClassMethod(Sel);

          if (Method && DiagnoseUseOfDecl(Method, SelectorSlotLocs))
            return ExprError();
        }
      }
      if (!Method) {
        // If not messaging 'self', look for any factory method named 'Sel'.
        if (!Receiver || !isSelfExpr(Receiver)) {
          // If no class (factory) method was found, check if an _instance_
          // method of the same name exists in the root class only.
          SmallVector<ObjCMethodDecl*, 4> Methods;
          CollectMultipleMethodsInGlobalPool(Sel, Methods,
                                             false/*InstanceFirst*/,
                                             true/*CheckTheOther*/);
          if (!Methods.empty()) {
            // We choose the first method as the initial candidate, then try
            // to select a better one.
            Method = Methods[0];

            // If we find an instance method, emit warning.
            if (Method->isInstanceMethod()) {
              if (const ObjCInterfaceDecl *ID =
                  dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
                if (ID->getSuperClass())
                  Diag(SelLoc, diag::warn_root_inst_method_not_found)
                      << Sel << SourceRange(LBracLoc, RBracLoc);
              }
            }

           if (ObjCMethodDecl *BestMethod =
               SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod(),
                                Methods))
             Method = BestMethod;
          }
        }
      }
    }
  } else {
    ObjCInterfaceDecl *ClassDecl = nullptr;

    // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
    // long as one of the protocols implements the selector (if not, warn).
    // And as long as message is not deprecated/unavailable (warn if it is).
    if (const ObjCObjectPointerType *QIdTy
                                 = ReceiverType->getAsObjCQualifiedIdType()) {
      // Search protocols for instance methods.
      Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
      if (!Method)
        Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
      if (Method && DiagnoseUseOfDecl(Method, SelectorSlotLocs))
        return ExprError();
    } else if (const ObjCObjectPointerType *OCIType
                 = ReceiverType->getAsObjCInterfacePointerType()) {
      // We allow sending a message to a pointer to an interface (an object).
      ClassDecl = OCIType->getInterfaceDecl();

      // Try to complete the type. Under ARC, this is a hard error from which
      // we don't try to recover.
      // FIXME: In the non-ARC case, this will still be a hard error if the
      // definition is found in a module that's not visible.
      const ObjCInterfaceDecl *forwardClass = nullptr;
      if (RequireCompleteType(Loc, OCIType->getPointeeType(),
                              getLangOpts().ObjCAutoRefCount
                                  ? diag::err_arc_receiver_forward_instance
                                  : diag::warn_receiver_forward_instance,
                              RecRange)) {
        if (getLangOpts().ObjCAutoRefCount)
          return ExprError();

        forwardClass = OCIType->getInterfaceDecl();
        Diag(Receiver ? Receiver->getBeginLoc() : SuperLoc,
             diag::note_receiver_is_id);
        Method = nullptr;
      } else {
        Method = ClassDecl->lookupInstanceMethod(Sel);
      }

      if (!Method)
        // Search protocol qualifiers.
        Method = LookupMethodInQualifiedType(Sel, OCIType, true);

      if (!Method) {
        // If we have implementations in scope, check "private" methods.
        Method = ClassDecl->lookupPrivateMethod(Sel);

        if (!Method && getLangOpts().ObjCAutoRefCount) {
          Diag(SelLoc, diag::err_arc_may_not_respond)
            << OCIType->getPointeeType() << Sel << RecRange
            << SourceRange(SelectorLocs.front(), SelectorLocs.back());
          return ExprError();
        }

        if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
          // If we still haven't found a method, look in the global pool. This
          // behavior isn't very desirable, however we need it for GCC
          // compatibility. FIXME: should we deviate??
          if (OCIType->qual_empty()) {
            SmallVector<ObjCMethodDecl*, 4> Methods;
            CollectMultipleMethodsInGlobalPool(Sel, Methods,
                                               true/*InstanceFirst*/,
                                               false/*CheckTheOther*/);
            if (!Methods.empty()) {
              // We choose the first method as the initial candidate, then try
              // to select a better one.
              Method = Methods[0];

              if (ObjCMethodDecl *BestMethod =
                  SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod(),
                                   Methods))
                Method = BestMethod;

              AreMultipleMethodsInGlobalPool(Sel, Method,
                                             SourceRange(LBracLoc, RBracLoc),
                                             true/*receiverIdOrClass*/,
                                             Methods);
            }
            if (Method && !forwardClass)
              Diag(SelLoc, diag::warn_maynot_respond)
                << OCIType->getInterfaceDecl()->getIdentifier()
                << Sel << RecRange;
          }
        }
      }
      if (Method && DiagnoseUseOfDecl(Method, SelectorSlotLocs, forwardClass))
        return ExprError();
    } else {
      // Reject other random receiver types (e.g. structs).
      Diag(Loc, diag::err_bad_receiver_type) << ReceiverType << RecRange;
      return ExprError();
    }
  }
}

FunctionScopeInfo *DIFunctionScopeInfo =
  (Method && Method->getMethodFamily() == OMF_init)
    ? getEnclosingFunction() : nullptr;

if (Method && Method->isDirectMethod()) {
  if (ReceiverType->isObjCIdType() && !isImplicit) {
    Diag(Receiver->getExprLoc(),
         diag::err_messaging_unqualified_id_with_direct_method);
    Diag(Method->getLocation(), diag::note_direct_method_declared_at)
        << Method->getDeclName();
  }

  // Under ARC, self can't be assigned, and doing a direct call to `self`
  // when it's a Class is hence safe.  For other cases, we can't trust `self`
  // is what we think it is, so we reject it.
  if (ReceiverType->isObjCClassType() && !isImplicit &&
      !(Receiver->isObjCSelfExpr() && getLangOpts().ObjCAutoRefCount)) {
    {
      auto Builder = Diag(Receiver->getExprLoc(),
                          diag::err_messaging_class_with_direct_method);
      if (Receiver->isObjCSelfExpr()) {
        Builder.AddFixItHint(FixItHint::CreateReplacement(
            RecRange, Method->getClassInterface()->getName()));
      }
    }
    Diag(Method->getLocation(), diag::note_direct_method_declared_at)
        << Method->getDeclName();
  }

  if (SuperLoc.isValid()) {
    {
      auto Builder =
          Diag(SuperLoc, diag::err_messaging_super_with_direct_method);
      if (ReceiverType->isObjCClassType()) {
        Builder.AddFixItHint(FixItHint::CreateReplacement(
            SuperLoc, Method->getClassInterface()->getName()));
      } else {
        Builder.AddFixItHint(FixItHint::CreateReplacement(SuperLoc, "self"));
      }
    }
    Diag(Method->getLocation(), diag::note_direct_method_declared_at)
        << Method->getDeclName();
  }
} else if (ReceiverType->isObjCIdType() && !isImplicit) {
  Diag(Receiver->getExprLoc(), diag::warn_messaging_unqualified_id);
}

if (DIFunctionScopeInfo &&
    DIFunctionScopeInfo->ObjCIsDesignatedInit &&
    (SuperLoc.isValid() || isSelfExpr(Receiver))) {
  bool isDesignatedInitChain = false;
  if (SuperLoc.isValid()) {
    if (const ObjCObjectPointerType *
          OCIType = ReceiverType->getAsObjCInterfacePointerType()) {
      if (const ObjCInterfaceDecl *ID = OCIType->getInterfaceDecl()) {
        // Either we know this is a designated initializer or we
        // conservatively assume it because we don't know for sure.
        if (!ID->declaresOrInheritsDesignatedInitializers() ||
            ID->isDesignatedInitializer(Sel)) {
          isDesignatedInitChain = true;
          DIFunctionScopeInfo->ObjCWarnForNoDesignatedInitChain = false;
        }
      }
    }
  }
  if (!isDesignatedInitChain) {
    const ObjCMethodDecl *InitMethod = nullptr;
    bool isDesignated =
      getCurMethodDecl()->isDesignatedInitializerForTheInterface(&InitMethod);
    assert(isDesignated && InitMethod)((void)0);
    (void)isDesignated;
    Diag(SelLoc, SuperLoc.isValid() ?
           diag::warn_objc_designated_init_non_designated_init_call :
           diag::warn_objc_designated_init_non_super_designated_init_call);
    Diag(InitMethod->getLocation(),
         diag::note_objc_designated_init_marked_here);
  }
}

if (DIFunctionScopeInfo &&
    DIFunctionScopeInfo->ObjCIsSecondaryInit &&
    (SuperLoc.isValid() || isSelfExpr(Receiver))) {
  if (SuperLoc.isValid()) {
    Diag(SelLoc, diag::warn_objc_secondary_init_super_init_call);
  } else {
    DIFunctionScopeInfo->ObjCWarnForNoInitDelegation = false;
  }
}

// Check the message arguments.
unsigned NumArgs = ArgsIn.size();
Expr **Args = ArgsIn.data();
QualType ReturnType;
ExprValueKind VK = VK_PRValue;
bool ClassMessage = (ReceiverType->isObjCClassType() ||
                     ReceiverType->isObjCQualifiedClassType());
if (CheckMessageArgumentTypes(Receiver, ReceiverType,
                              MultiExprArg(Args, NumArgs), Sel, SelectorLocs,
                              Method, ClassMessage, SuperLoc.isValid(),
                              LBracLoc, RBracLoc, RecRange, ReturnType, VK))
  return ExprError();

if (Method && !Method->getReturnType()->isVoidType() &&
    RequireCompleteType(LBracLoc, Method->getReturnType(),
                        diag::err_illegal_message_expr_incomplete_type))
  return ExprError();

// In ARC, forbid the user from sending messages to
// retain/release/autorelease/dealloc/retainCount explicitly.
if (getLangOpts().ObjCAutoRefCount) {
  ObjCMethodFamily family =
    (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
  switch (family) {
  case OMF_init:
    if (Method)
      checkInitMethod(Method, ReceiverType);
    break;

  case OMF_None:
  case OMF_alloc:
  case OMF_copy:
  case OMF_finalize:
  case OMF_mutableCopy:
  case OMF_new:
  case OMF_self:
  case OMF_initialize:
    break;

  case OMF_dealloc:
  case OMF_retain:
  case OMF_release:
  case OMF_autorelease:
  case OMF_retainCount:
    Diag(SelLoc, diag::err_arc_illegal_explicit_message)
      << Sel << RecRange;
    break;

  case OMF_performSelector:
    if (Method && NumArgs >= 1) {
      if (const auto *SelExp =
              dyn_cast<ObjCSelectorExpr>(Args[0]->IgnoreParens())) {
        Selector ArgSel = SelExp->getSelector();
        ObjCMethodDecl *SelMethod =
          LookupInstanceMethodInGlobalPool(ArgSel,
                                           SelExp->getSourceRange());
        if (!SelMethod)
          SelMethod =
            LookupFactoryMethodInGlobalPool(ArgSel,
                                            SelExp->getSourceRange());
        if (SelMethod) {
          ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
          switch (SelFamily) {
            case OMF_alloc:
            case OMF_copy:
            case OMF_mutableCopy:
            case OMF_new:
            case OMF_init:
              // Issue error, unless ns_returns_not_retained.
              if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
                // selector names a +1 method
                Diag(SelLoc,
                     diag::err_arc_perform_selector_retains);
                Diag(SelMethod->getLocation(), diag::note_method_declared_at)
                  << SelMethod->getDeclName();
              }
              break;
            default:
              // +0 call. OK. unless ns_returns_retained.
              if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
                // selector names a +1 method
                Diag(SelLoc,
                     diag::err_arc_perform_selector_retains);
                Diag(SelMethod->getLocation(), diag::note_method_declared_at)
                  << SelMethod->getDeclName();
              }
              break;
          }
        }
      } else {
        // error (may leak).
        Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
        Diag(Args[0]->getExprLoc(), diag::note_used_here);
      }
    }
    break;
  }
}

DiagnoseCStringFormatDirectiveInObjCAPI(*this, Method, Sel, Args, NumArgs);

// Construct the appropriate ObjCMessageExpr instance.
ObjCMessageExpr *Result;
if (SuperLoc.isValid())
  Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
                                   SuperLoc,  /*IsInstanceSuper=*/true,
                                   ReceiverType, Sel, SelectorLocs, Method,
                                   makeArrayRef(Args, NumArgs), RBracLoc,
                                   isImplicit);
else {
  Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
                                   Receiver, Sel, SelectorLocs, Method,
                                   makeArrayRef(Args, NumArgs), RBracLoc,
                                   isImplicit);
  if (!isImplicit)
    checkCocoaAPI(*this, Result);
}
if (Method) {
  bool IsClassObjectCall = ClassMessage;
  // 'self' message receivers in class methods should be treated as message
  // sends to the class object in order for the semantic checks to be
  // performed correctly. Messages to 'super' already count as class messages,
  // so they don't need to be handled here.
  if (Receiver && isSelfExpr(Receiver)) {
    if (const auto *OPT = ReceiverType->getAs<ObjCObjectPointerType>()) {
      if (OPT->getObjectType()->isObjCClass()) {
        if (const auto *CurMeth = getCurMethodDecl()) {
          IsClassObjectCall = true;
          ReceiverType =
              Context.getObjCInterfaceType(CurMeth->getClassInterface());
        }
      }
    }
  }
  checkFoundationAPI(*this, SelLoc, Method, makeArrayRef(Args, NumArgs),
                     ReceiverType, IsClassObjectCall);
}

if (getLangOpts().ObjCAutoRefCount) {
  // In ARC, annotate delegate init calls.
  if (Result->getMethodFamily() == OMF_init &&
      (SuperLoc.isValid() || isSelfExpr(Receiver))) {
    // Only consider init calls *directly* in init implementations,
    // not within blocks.
    ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
    if (method && method->getMethodFamily() == OMF_init) {
      // The implicit assignment to self means we also don't want to
      // consume the result.
      Result->setDelegateInitCall(true);
      return Result;
    }
  }

  // In ARC, check for message sends which are likely to introduce
  // retain cycles.
  checkRetainCycles(Result);
}

if (getLangOpts().ObjCWeak) {
  if (!isImplicit && Method) {
    if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
      bool IsWeak =
          Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_weak;
      if (!IsWeak && Sel.isUnarySelector())
        IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
      if (IsWeak && !isUnevaluatedContext() &&
          !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, LBracLoc))
        getCurFunction()->recordUseOfWeak(Result, Prop);
    }
  }
}

CheckObjCCircularContainer(Result);

return MaybeBindToTemporary(Result);
3400}

3402static void RemoveSelectorFromWarningCache(Sema &S, Expr* Arg) {
if (ObjCSelectorExpr *OSE =
    dyn_cast<ObjCSelectorExpr>(Arg->IgnoreParenCasts())) {
  Selector Sel = OSE->getSelector();
  SourceLocation Loc = OSE->getAtLoc();
  auto Pos = S.ReferencedSelectors.find(Sel);
  if (Pos != S.ReferencedSelectors.end() && Pos->second == Loc)
    S.ReferencedSelectors.erase(Pos);
}
3411}

3413// ActOnInstanceMessage - used for both unary and keyword messages.
3414// ArgExprs is optional - if it is present, the number of expressions
3415// is obtained from Sel.getNumArgs().
3416ExprResult Sema::ActOnInstanceMessage(Scope *S,
                                    Expr *Receiver,
                                    Selector Sel,
                                    SourceLocation LBracLoc,
                                    ArrayRef<SourceLocation> SelectorLocs,
                                    SourceLocation RBracLoc,
                                    MultiExprArg Args) {
if (!Receiver)
  return ExprError();

// A ParenListExpr can show up while doing error recovery with invalid code.
if (isa<ParenListExpr>(Receiver)) {
  ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Receiver);
  if (Result.isInvalid()) return ExprError();
  Receiver = Result.get();
}

if (RespondsToSelectorSel.isNull()) {
  IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
  RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
}
if (Sel == RespondsToSelectorSel)
  RemoveSelectorFromWarningCache(*this, Args[0]);

return BuildInstanceMessage(Receiver, Receiver->getType(),
                            /*SuperLoc=*/SourceLocation(), Sel,
                            /*Method=*/nullptr, LBracLoc, SelectorLocs,
                            RBracLoc, Args);
3444}

3446enum ARCConversionTypeClass {
/// int, void, struct A
ACTC_none,

/// id, void (^)()
ACTC_retainable,

/// id*, id***, void (^*)(),
ACTC_indirectRetainable,

/// void* might be a normal C type, or it might a CF type.
ACTC_voidPtr,

/// struct A*
ACTC_coreFoundation
3461};

3463static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
return (ACTC == ACTC_retainable ||
        ACTC == ACTC_coreFoundation ||
        ACTC == ACTC_voidPtr);
3467}

3469static bool isAnyCLike(ARCConversionTypeClass ACTC) {
return ACTC == ACTC_none ||
       ACTC == ACTC_voidPtr ||
       ACTC == ACTC_coreFoundation;
3473}

3475static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
bool isIndirect = false;

// Ignore an outermost reference type.
if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
  type = ref->getPointeeType();
  isIndirect = true;
}

// Drill through pointers and arrays recursively.
while (true) {
  if (const PointerType *ptr = type->getAs<PointerType>()) {
    type = ptr->getPointeeType();

    // The first level of pointer may be the innermost pointer on a CF type.
    if (!isIndirect) {
      if (type->isVoidType()) return ACTC_voidPtr;
      if (type->isRecordType()) return ACTC_coreFoundation;
    }
  } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
    type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
  } else {
    break;
  }
  isIndirect = true;
}

if (isIndirect) {
  if (type->isObjCARCBridgableType())
    return ACTC_indirectRetainable;
  return ACTC_none;
}

if (type->isObjCARCBridgableType())
  return ACTC_retainable;

return ACTC_none;
3512}

3514namespace {
/// A result from the cast checker.
enum ACCResult {
  /// Cannot be casted.
  ACC_invalid,

  /// Can be safely retained or not retained.
  ACC_bottom,

  /// Can be casted at +0.
  ACC_plusZero,

  /// Can be casted at +1.
  ACC_plusOne
};
ACCResult merge(ACCResult left, ACCResult right) {
  if (left == right) return left;
  if (left == ACC_bottom) return right;
  if (right == ACC_bottom) return left;
  return ACC_invalid;
}

/// A checker which white-lists certain expressions whose conversion
/// to or from retainable type would otherwise be forbidden in ARC.
class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
  typedef StmtVisitor<ARCCastChecker, ACCResult> super;

  ASTContext &Context;
  ARCConversionTypeClass SourceClass;
  ARCConversionTypeClass TargetClass;
  bool Diagnose;

  static bool isCFType(QualType type) {
    // Someday this can use ns_bridged.  For now, it has to do this.
    return type->isCARCBridgableType();
  }

public:
  ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
                 ARCConversionTypeClass target, bool diagnose)
    : Context(Context), SourceClass(source), TargetClass(target),
      Diagnose(diagnose) {}

  using super::Visit;
  ACCResult Visit(Expr *e) {
    return super::Visit(e->IgnoreParens());
  }

  ACCResult VisitStmt(Stmt *s) {
    return ACC_invalid;
  }

  /// Null pointer constants can be casted however you please.
  ACCResult VisitExpr(Expr *e) {
    if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
      return ACC_bottom;
    return ACC_invalid;
  }

  /// Objective-C string literals can be safely casted.
  ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
    // If we're casting to any retainable type, go ahead.  Global
    // strings are immune to retains, so this is bottom.
    if (isAnyRetainable(TargetClass)) return ACC_bottom;

    return ACC_invalid;
  }

  /// Look through certain implicit and explicit casts.
  ACCResult VisitCastExpr(CastExpr *e) {
    switch (e->getCastKind()) {
      case CK_NullToPointer:
        return ACC_bottom;

      case CK_NoOp:
      case CK_LValueToRValue:
      case CK_BitCast:
      case CK_CPointerToObjCPointerCast:
      case CK_BlockPointerToObjCPointerCast:
      case CK_AnyPointerToBlockPointerCast:
        return Visit(e->getSubExpr());

      default:
        return ACC_invalid;
    }
  }

  /// Look through unary extension.
  ACCResult VisitUnaryExtension(UnaryOperator *e) {
    return Visit(e->getSubExpr());
  }

  /// Ignore the LHS of a comma operator.
  ACCResult VisitBinComma(BinaryOperator *e) {
    return Visit(e->getRHS());
  }

  /// Conditional operators are okay if both sides are okay.
  ACCResult VisitConditionalOperator(ConditionalOperator *e) {
    ACCResult left = Visit(e->getTrueExpr());
    if (left == ACC_invalid) return ACC_invalid;
    return merge(left, Visit(e->getFalseExpr()));
  }

  /// Look through pseudo-objects.
  ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
    // If we're getting here, we should always have a result.
    return Visit(e->getResultExpr());
  }

  /// Statement expressions are okay if their result expression is okay.
  ACCResult VisitStmtExpr(StmtExpr *e) {
    return Visit(e->getSubStmt()->body_back());
  }

  /// Some declaration references are okay.
  ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
    VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
    // References to global constants are okay.
    if (isAnyRetainable(TargetClass) &&
        isAnyRetainable(SourceClass) &&
        var &&
        !var->hasDefinition(Context) &&
        var->getType().isConstQualified()) {

      // In system headers, they can also be assumed to be immune to retains.
      // These are things like 'kCFStringTransformToLatin'.
      if (Context.getSourceManager().isInSystemHeader(var->getLocation()))
        return ACC_bottom;

      return ACC_plusZero;
    }

    // Nothing else.
    return ACC_invalid;
  }

  /// Some calls are okay.
  ACCResult VisitCallExpr(CallExpr *e) {
    if (FunctionDecl *fn = e->getDirectCallee())
      if (ACCResult result = checkCallToFunction(fn))
        return result;

    return super::VisitCallExpr(e);
  }

  ACCResult checkCallToFunction(FunctionDecl *fn) {
    // Require a CF*Ref return type.
    if (!isCFType(fn->getReturnType()))
      return ACC_invalid;

    if (!isAnyRetainable(TargetClass))
      return ACC_invalid;

    // Honor an explicit 'not retained' attribute.
    if (fn->hasAttr<CFReturnsNotRetainedAttr>())
      return ACC_plusZero;

    // Honor an explicit 'retained' attribute, except that for
    // now we're not going to permit implicit handling of +1 results,
    // because it's a bit frightening.
    if (fn->hasAttr<CFReturnsRetainedAttr>())
      return Diagnose ? ACC_plusOne
                      : ACC_invalid; // ACC_plusOne if we start accepting this

    // Recognize this specific builtin function, which is used by CFSTR.
    unsigned builtinID = fn->getBuiltinID();
    if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
      return ACC_bottom;

    // Otherwise, don't do anything implicit with an unaudited function.
    if (!fn->hasAttr<CFAuditedTransferAttr>())
      return ACC_invalid;

    // Otherwise, it's +0 unless it follows the create convention.
    if (ento::coreFoundation::followsCreateRule(fn))
      return Diagnose ? ACC_plusOne
                      : ACC_invalid; // ACC_plusOne if we start accepting this

    return ACC_plusZero;
  }

  ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
    return checkCallToMethod(e->getMethodDecl());
  }

  ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
    ObjCMethodDecl *method;
    if (e->isExplicitProperty())
      method = e->getExplicitProperty()->getGetterMethodDecl();
    else
      method = e->getImplicitPropertyGetter();
    return checkCallToMethod(method);
  }

  ACCResult checkCallToMethod(ObjCMethodDecl *method) {
    if (!method) return ACC_invalid;

    // Check for message sends to functions returning CF types.  We
    // just obey the Cocoa conventions with these, even though the
    // return type is CF.
    if (!isAnyRetainable(TargetClass) || !isCFType(method->getReturnType()))
      return ACC_invalid;

    // If the method is explicitly marked not-retained, it's +0.
    if (method->hasAttr<CFReturnsNotRetainedAttr>())
      return ACC_plusZero;

    // If the method is explicitly marked as returning retained, or its
    // selector follows a +1 Cocoa convention, treat it as +1.
    if (method->hasAttr<CFReturnsRetainedAttr>())
      return ACC_plusOne;

    switch (method->getSelector().getMethodFamily()) {
    case OMF_alloc:
    case OMF_copy:
    case OMF_mutableCopy:
    case OMF_new:
      return ACC_plusOne;

    default:
      // Otherwise, treat it as +0.
      return ACC_plusZero;
    }
  }
};
3740} // end anonymous namespace

3742bool Sema::isKnownName(StringRef name) {
if (name.empty())
  return false;
LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
               Sema::LookupOrdinaryName);
return LookupName(R, TUScope, false);
3748}

3750template <typename DiagBuilderT>
3751static void addFixitForObjCARCConversion(
  Sema &S, DiagBuilderT &DiagB, Sema::CheckedConversionKind CCK,
  SourceLocation afterLParen, QualType castType, Expr *castExpr,
  Expr *realCast, const char *bridgeKeyword, const char *CFBridgeName) {
// We handle C-style and implicit casts here.
switch (CCK) {
case Sema::CCK_ImplicitConversion:
case Sema::CCK_ForBuiltinOverloadedOp:
case Sema::CCK_CStyleCast:
case Sema::CCK_OtherCast:
  break;
case Sema::CCK_FunctionalCast:
  return;
}

if (CFBridgeName) {
  if (CCK == Sema::CCK_OtherCast) {
    if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
      SourceRange range(NCE->getOperatorLoc(),
                        NCE->getAngleBrackets().getEnd());
      SmallString<32> BridgeCall;

      SourceManager &SM = S.getSourceManager();
      char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
      if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
        BridgeCall += ' ';

      BridgeCall += CFBridgeName;
      DiagB.AddFixItHint(FixItHint::CreateReplacement(range, BridgeCall));
    }
    return;
  }
  Expr *castedE = castExpr;
  if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
    castedE = CCE->getSubExpr();
  castedE = castedE->IgnoreImpCasts();
  SourceRange range = castedE->getSourceRange();

  SmallString<32> BridgeCall;

  SourceManager &SM = S.getSourceManager();
  char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
  if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
    BridgeCall += ' ';

  BridgeCall += CFBridgeName;

  if (isa<ParenExpr>(castedE)) {
    DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
                       BridgeCall));
  } else {
    BridgeCall += '(';
    DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
                                                  BridgeCall));
    DiagB.AddFixItHint(FixItHint::CreateInsertion(
                                     S.getLocForEndOfToken(range.getEnd()),
                                     ")"));
  }
  return;
}

if (CCK == Sema::CCK_CStyleCast) {
  DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
} else if (CCK == Sema::CCK_OtherCast) {
  if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
    std::string castCode = "(";
    castCode += bridgeKeyword;
    castCode += castType.getAsString();
    castCode += ")";
    SourceRange Range(NCE->getOperatorLoc(),
                      NCE->getAngleBrackets().getEnd());
    DiagB.AddFixItHint(FixItHint::CreateReplacement(Range, castCode));
  }
} else {
  std::string castCode = "(";
  castCode += bridgeKeyword;
  castCode += castType.getAsString();
  castCode += ")";
  Expr *castedE = castExpr->IgnoreImpCasts();
  SourceRange range = castedE->getSourceRange();
  if (isa<ParenExpr>(castedE)) {
    DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
                       castCode));
  } else {
    castCode += "(";
    DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
                                                  castCode));
    DiagB.AddFixItHint(FixItHint::CreateInsertion(
                                     S.getLocForEndOfToken(range.getEnd()),
                                     ")"));
  }
}
3843}

3845template <typename T>
3846static inline T *getObjCBridgeAttr(const TypedefType *TD) {
TypedefNameDecl *TDNDecl = TD->getDecl();
QualType QT = TDNDecl->getUnderlyingType();
if (QT->isPointerType()) {
  QT = QT->getPointeeType();
  if (const RecordType *RT = QT->getAs<RecordType>()) {
    for (auto *Redecl : RT->getDecl()->getMostRecentDecl()->redecls()) {
      if (auto *attr = Redecl->getAttr<T>())
        return attr;
    }
  }
}
return nullptr;
3859}

3861static ObjCBridgeRelatedAttr *ObjCBridgeRelatedAttrFromType(QualType T,
                                                          TypedefNameDecl *&TDNDecl) {
while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
  TDNDecl = TD->getDecl();
  if (ObjCBridgeRelatedAttr *ObjCBAttr =
      getObjCBridgeAttr<ObjCBridgeRelatedAttr>(TD))
    return ObjCBAttr;
  T = TDNDecl->getUnderlyingType();
}
return nullptr;
3871}

3873static void
3874diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
                        QualType castType, ARCConversionTypeClass castACTC,
                        Expr *castExpr, Expr *realCast,
                        ARCConversionTypeClass exprACTC,
                        Sema::CheckedConversionKind CCK) {
SourceLocation loc =
  (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());

if (S.makeUnavailableInSystemHeader(loc,
                               UnavailableAttr::IR_ARCForbiddenConversion))
  return;

QualType castExprType = castExpr->getType();
// Defer emitting a diagnostic for bridge-related casts; that will be
// handled by CheckObjCBridgeRelatedConversions.
TypedefNameDecl *TDNDecl = nullptr;
if ((castACTC == ACTC_coreFoundation &&  exprACTC == ACTC_retainable &&
     ObjCBridgeRelatedAttrFromType(castType, TDNDecl)) ||
    (exprACTC == ACTC_coreFoundation && castACTC == ACTC_retainable &&
     ObjCBridgeRelatedAttrFromType(castExprType, TDNDecl)))
  return;

unsigned srcKind = 0;
switch (exprACTC) {
case ACTC_none:
case ACTC_coreFoundation:
case ACTC_voidPtr:
  srcKind = (castExprType->isPointerType() ? 1 : 0);
  break;
case ACTC_retainable:
  srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
  break;
case ACTC_indirectRetainable:
  srcKind = 4;
  break;
}

// Check whether this could be fixed with a bridge cast.
SourceLocation afterLParen = S.getLocForEndOfToken(castRange.getBegin());
SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;

unsigned convKindForDiag = Sema::isCast(CCK) ? 0 : 1;

// Bridge from an ARC type to a CF type.
if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {

  S.Diag(loc, diag::err_arc_cast_requires_bridge)
    << convKindForDiag
    << 2 // of C pointer type
    << castExprType
    << unsigned(castType->isBlockPointerType()) // to ObjC|block type
    << castType
    << castRange
    << castExpr->getSourceRange();
  bool br = S.isKnownName("CFBridgingRelease");
  ACCResult CreateRule =
    ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
  assert(CreateRule != ACC_bottom && "This cast should already be accepted.")((void)0);
  if (CreateRule != ACC_plusOne)
  {
    auto DiagB = (CCK != Sema::CCK_OtherCast)
                     ? S.Diag(noteLoc, diag::note_arc_bridge)
                     : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);

    addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
                                 castType, castExpr, realCast, "__bridge ",
                                 nullptr);
  }
  if (CreateRule != ACC_plusZero)
  {
    auto DiagB = (CCK == Sema::CCK_OtherCast && !br)
                     ? S.Diag(noteLoc, diag::note_arc_cstyle_bridge_transfer)
                           << castExprType
                     : S.Diag(br ? castExpr->getExprLoc() : noteLoc,
                              diag::note_arc_bridge_transfer)
                           << castExprType << br;

    addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
                                 castType, castExpr, realCast, "__bridge_transfer ",
                                 br ? "CFBridgingRelease" : nullptr);
  }

  return;
}

// Bridge from a CF type to an ARC type.
if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
  bool br = S.isKnownName("CFBridgingRetain");
  S.Diag(loc, diag::err_arc_cast_requires_bridge)
    << convKindForDiag
    << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
    << castExprType
    << 2 // to C pointer type
    << castType
    << castRange
    << castExpr->getSourceRange();
  ACCResult CreateRule =
    ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
  assert(CreateRule != ACC_bottom && "This cast should already be accepted.")((void)0);
  if (CreateRule != ACC_plusOne)
  {
    auto DiagB = (CCK != Sema::CCK_OtherCast)
                     ? S.Diag(noteLoc, diag::note_arc_bridge)
                     : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
    addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
                                 castType, castExpr, realCast, "__bridge ",
                                 nullptr);
  }
  if (CreateRule != ACC_plusZero)
  {
    auto DiagB = (CCK == Sema::CCK_OtherCast && !br)
                     ? S.Diag(noteLoc, diag::note_arc_cstyle_bridge_retained)
                           << castType
                     : S.Diag(br ? castExpr->getExprLoc() : noteLoc,
                              diag::note_arc_bridge_retained)
                           << castType << br;

    addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
                                 castType, castExpr, realCast, "__bridge_retained ",
                                 br ? "CFBridgingRetain" : nullptr);
  }

  return;
}

S.Diag(loc, diag::err_arc_mismatched_cast)
  << !convKindForDiag
  << srcKind << castExprType << castType
  << castRange << castExpr->getSourceRange();
4003}

4005template <typename TB>
4006static bool CheckObjCBridgeNSCast(Sema &S, QualType castType, Expr *castExpr,
                                bool &HadTheAttribute, bool warn) {
QualType T = castExpr->getType();
HadTheAttribute = false;
while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
  TypedefNameDecl *TDNDecl = TD->getDecl();
  if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
    if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
      HadTheAttribute = true;
      if (Parm->isStr("id"))
        return true;

      NamedDecl *Target = nullptr;
      // Check for an existing type with this name.
      LookupResult R(S, DeclarationName(Parm), SourceLocation(),
                     Sema::LookupOrdinaryName);
      if (S.LookupName(R, S.TUScope)) {
        Target = R.getFoundDecl();
        if (Target && isa<ObjCInterfaceDecl>(Target)) {
          ObjCInterfaceDecl *ExprClass = cast<ObjCInterfaceDecl>(Target);
          if (const ObjCObjectPointerType *InterfacePointerType =
                castType->getAsObjCInterfacePointerType()) {
            ObjCInterfaceDecl *CastClass
              = InterfacePointerType->getObjectType()->getInterface();
            if ((CastClass == ExprClass) ||
                (CastClass && CastClass->isSuperClassOf(ExprClass)))
              return true;
            if (warn)
              S.Diag(castExpr->getBeginLoc(), diag::warn_objc_invalid_bridge)
                  << T << Target->getName() << castType->getPointeeType();
            return false;
          } else if (castType->isObjCIdType() ||
                     (S.Context.ObjCObjectAdoptsQTypeProtocols(
                        castType, ExprClass)))
            // ok to cast to 'id'.
            // casting to id<p-list> is ok if bridge type adopts all of
            // p-list protocols.
            return true;
          else {
            if (warn) {
              S.Diag(castExpr->getBeginLoc(), diag::warn_objc_invalid_bridge)
                  << T << Target->getName() << castType;
              S.Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
              S.Diag(Target->getBeginLoc(), diag::note_declared_at);
            }
            return false;
         }
        }
      } else if (!castType->isObjCIdType()) {
        S.Diag(castExpr->getBeginLoc(),
               diag::err_objc_cf_bridged_not_interface)
            << castExpr->getType() << Parm;
        S.Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
        if (Target)
          S.Diag(Target->getBeginLoc(), diag::note_declared_at);
      }
      return true;
    }
    return false;
  }
  T = TDNDecl->getUnderlyingType();
}
return true;
4069}

4071template <typename TB>
4072static bool CheckObjCBridgeCFCast(Sema &S, QualType castType, Expr *castExpr,
                                bool &HadTheAttribute, bool warn) {
QualType T = castType;
HadTheAttribute = false;
while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
  TypedefNameDecl *TDNDecl = TD->getDecl();
  if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
    if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
      HadTheAttribute = true;
      if (Parm->isStr("id"))
        return true;

      NamedDecl *Target = nullptr;
      // Check for an existing type with this name.
      LookupResult R(S, DeclarationName(Parm), SourceLocation(),
                     Sema::LookupOrdinaryName);
      if (S.LookupName(R, S.TUScope)) {
        Target = R.getFoundDecl();
        if (Target && isa<ObjCInterfaceDecl>(Target)) {
          ObjCInterfaceDecl *CastClass = cast<ObjCInterfaceDecl>(Target);
          if (const ObjCObjectPointerType *InterfacePointerType =
                castExpr->getType()->getAsObjCInterfacePointerType()) {
            ObjCInterfaceDecl *ExprClass
              = InterfacePointerType->getObjectType()->getInterface();
            if ((CastClass == ExprClass) ||
                (ExprClass && CastClass->isSuperClassOf(ExprClass)))
              return true;
            if (warn) {
              S.Diag(castExpr->getBeginLoc(),
                     diag::warn_objc_invalid_bridge_to_cf)
                  << castExpr->getType()->getPointeeType() << T;
              S.Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
            }
            return false;
          } else if (castExpr->getType()->isObjCIdType() ||
                     (S.Context.QIdProtocolsAdoptObjCObjectProtocols(
                        castExpr->getType(), CastClass)))
            // ok to cast an 'id' expression to a CFtype.
            // ok to cast an 'id<plist>' expression to CFtype provided plist
            // adopts all of CFtype's ObjetiveC's class plist.
            return true;
          else {
            if (warn) {
              S.Diag(castExpr->getBeginLoc(),
                     diag::warn_objc_invalid_bridge_to_cf)
                  << castExpr->getType() << castType;
              S.Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
              S.Diag(Target->getBeginLoc(), diag::note_declared_at);
            }
            return false;
          }
        }
      }
      S.Diag(castExpr->getBeginLoc(),
             diag::err_objc_ns_bridged_invalid_cfobject)
          << castExpr->getType() << castType;
      S.Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
      if (Target)
        S.Diag(Target->getBeginLoc(), diag::note_declared_at);
      return true;
    }
    return false;
  }
  T = TDNDecl->getUnderlyingType();
}
return true;
4138}

4140void Sema::CheckTollFreeBridgeCast(QualType castType, Expr *castExpr) {
if (!getLangOpts().ObjC)
  return;
// warn in presence of __bridge casting to or from a toll free bridge cast.
ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExpr->getType());
ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
if (castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) {
  bool HasObjCBridgeAttr;
  bool ObjCBridgeAttrWillNotWarn =
    CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
                                          false);
  if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
    return;
  bool HasObjCBridgeMutableAttr;
  bool ObjCBridgeMutableAttrWillNotWarn =
    CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
                                                 HasObjCBridgeMutableAttr, false);
  if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
    return;

  if (HasObjCBridgeAttr)
    CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
                                          true);
  else if (HasObjCBridgeMutableAttr)
    CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
                                                 HasObjCBridgeMutableAttr, true);
}
else if (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable) {
  bool HasObjCBridgeAttr;
  bool ObjCBridgeAttrWillNotWarn =
    CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
                                          false);
  if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
    return;
  bool HasObjCBridgeMutableAttr;
  bool ObjCBridgeMutableAttrWillNotWarn =
    CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
                                                 HasObjCBridgeMutableAttr, false);
  if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
    return;

  if (HasObjCBridgeAttr)
    CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
                                          true);
  else if (HasObjCBridgeMutableAttr)
    CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
                                                 HasObjCBridgeMutableAttr, true);
}
4188}

4190void Sema::CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr) {
QualType SrcType = castExpr->getType();
if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(castExpr)) {
  if (PRE->isExplicitProperty()) {
    if (ObjCPropertyDecl *PDecl = PRE->getExplicitProperty())
      SrcType = PDecl->getType();
  }
  else if (PRE->isImplicitProperty()) {
    if (ObjCMethodDecl *Getter = PRE->getImplicitPropertyGetter())
      SrcType = Getter->getReturnType();
  }
}

ARCConversionTypeClass srcExprACTC = classifyTypeForARCConversion(SrcType);
ARCConversionTypeClass castExprACTC = classifyTypeForARCConversion(castType);
if (srcExprACTC != ACTC_retainable || castExprACTC != ACTC_coreFoundation)
  return;
CheckObjCBridgeRelatedConversions(castExpr->getBeginLoc(), castType, SrcType,
                                  castExpr);
4209}

4211bool Sema::CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
                                       CastKind &Kind) {
if (!getLangOpts().ObjC)
  return false;
ARCConversionTypeClass exprACTC =
  classifyTypeForARCConversion(castExpr->getType());
ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
if ((castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) ||
    (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable)) {
  CheckTollFreeBridgeCast(castType, castExpr);
  Kind = (castACTC == ACTC_coreFoundation) ? CK_BitCast
                                           : CK_CPointerToObjCPointerCast;
  return true;
}
return false;
4226}

4228bool Sema::checkObjCBridgeRelatedComponents(SourceLocation Loc,
                                          QualType DestType, QualType SrcType,
                                          ObjCInterfaceDecl *&RelatedClass,
                                          ObjCMethodDecl *&ClassMethod,
                                          ObjCMethodDecl *&InstanceMethod,
                                          TypedefNameDecl *&TDNDecl,
                                          bool CfToNs, bool Diagnose) {
QualType T = CfToNs ? SrcType : DestType;
ObjCBridgeRelatedAttr *ObjCBAttr = ObjCBridgeRelatedAttrFromType(T, TDNDecl);
if (!ObjCBAttr)
  return false;

IdentifierInfo *RCId = ObjCBAttr->getRelatedClass();
IdentifierInfo *CMId = ObjCBAttr->getClassMethod();
IdentifierInfo *IMId = ObjCBAttr->getInstanceMethod();
if (!RCId)
  return false;
NamedDecl *Target = nullptr;
// Check for an existing type with this name.
LookupResult R(*this, DeclarationName(RCId), SourceLocation(),
               Sema::LookupOrdinaryName);
if (!LookupName(R, TUScope)) {
  if (Diagnose) {
    Diag(Loc, diag::err_objc_bridged_related_invalid_class) << RCId
          << SrcType << DestType;
    Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
  }
  return false;
}
Target = R.getFoundDecl();
if (Target && isa<ObjCInterfaceDecl>(Target))
  RelatedClass = cast<ObjCInterfaceDecl>(Target);
else {
  if (Diagnose) {
    Diag(Loc, diag::err_objc_bridged_related_invalid_class_name) << RCId
          << SrcType << DestType;
    Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
    if (Target)
      Diag(Target->getBeginLoc(), diag::note_declared_at);
  }
  return false;
}

// Check for an existing class method with the given selector name.
if (CfToNs && CMId) {
  Selector Sel = Context.Selectors.getUnarySelector(CMId);
  ClassMethod = RelatedClass->lookupMethod(Sel, false);
  if (!ClassMethod) {
    if (Diagnose) {
      Diag(Loc, diag::err_objc_bridged_related_known_method)
            << SrcType << DestType << Sel << false;
      Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
    }
    return false;
  }
}

// Check for an existing instance method with the given selector name.
if (!CfToNs && IMId) {
  Selector Sel = Context.Selectors.getNullarySelector(IMId);
  InstanceMethod = RelatedClass->lookupMethod(Sel, true);
  if (!InstanceMethod) {
    if (Diagnose) {
      Diag(Loc, diag::err_objc_bridged_related_known_method)
            << SrcType << DestType << Sel << true;
      Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);
    }
    return false;
  }
}
return true;
4299}

4301bool
4302Sema::CheckObjCBridgeRelatedConversions(SourceLocation Loc,
                                      QualType DestType, QualType SrcType,
                                      Expr *&SrcExpr, bool Diagnose) {
ARCConversionTypeClass rhsExprACTC = classifyTypeForARCConversion(SrcType);
ARCConversionTypeClass lhsExprACTC = classifyTypeForARCConversion(DestType);
bool CfToNs = (rhsExprACTC == ACTC_coreFoundation && lhsExprACTC == ACTC_retainable);
bool NsToCf = (rhsExprACTC == ACTC_retainable && lhsExprACTC == ACTC_coreFoundation);
if (!CfToNs && !NsToCf)
  return false;

ObjCInterfaceDecl *RelatedClass;
ObjCMethodDecl *ClassMethod = nullptr;
ObjCMethodDecl *InstanceMethod = nullptr;
TypedefNameDecl *TDNDecl = nullptr;
if (!checkObjCBridgeRelatedComponents(Loc, DestType, SrcType, RelatedClass,
                                      ClassMethod, InstanceMethod, TDNDecl,
                                      CfToNs, Diagnose))
  return false;

if (CfToNs) {
  // Implicit conversion from CF to ObjC object is needed.
  if (ClassMethod) {
    if (Diagnose) {
      std::string ExpressionString = "[";
      ExpressionString += RelatedClass->getNameAsString();
      ExpressionString += " ";
      ExpressionString += ClassMethod->getSelector().getAsString();
      SourceLocation SrcExprEndLoc =
          getLocForEndOfToken(SrcExpr->getEndLoc());
      // Provide a fixit: [RelatedClass ClassMethod SrcExpr]
      Diag(Loc, diag::err_objc_bridged_related_known_method)
          << SrcType << DestType << ClassMethod->getSelector() << false
          << FixItHint::CreateInsertion(SrcExpr->getBeginLoc(),
                                        ExpressionString)
          << FixItHint::CreateInsertion(SrcExprEndLoc, "]");
      Diag(RelatedClass->getBeginLoc(), diag::note_declared_at);
      Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);

      QualType receiverType = Context.getObjCInterfaceType(RelatedClass);
      // Argument.
      Expr *args[] = { SrcExpr };
      ExprResult msg = BuildClassMessageImplicit(receiverType, false,
                                    ClassMethod->getLocation(),
                                    ClassMethod->getSelector(), ClassMethod,
                                    MultiExprArg(args, 1));
      SrcExpr = msg.get();
    }
    return true;
  }
}
else {
  // Implicit conversion from ObjC type to CF object is needed.
  if (InstanceMethod) {
    if (Diagnose) {
      std::string ExpressionString;
      SourceLocation SrcExprEndLoc =
          getLocForEndOfToken(SrcExpr->getEndLoc());
      if (InstanceMethod->isPropertyAccessor())
        if (const ObjCPropertyDecl *PDecl =
                InstanceMethod->findPropertyDecl()) {
          // fixit: ObjectExpr.propertyname when it is  aproperty accessor.
          ExpressionString = ".";
          ExpressionString += PDecl->getNameAsString();
          Diag(Loc, diag::err_objc_bridged_related_known_method)
              << SrcType << DestType << InstanceMethod->getSelector() << true
              << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
        }
      if (ExpressionString.empty()) {
        // Provide a fixit: [ObjectExpr InstanceMethod]
        ExpressionString = " ";
        ExpressionString += InstanceMethod->getSelector().getAsString();
        ExpressionString += "]";

        Diag(Loc, diag::err_objc_bridged_related_known_method)
            << SrcType << DestType << InstanceMethod->getSelector() << true
            << FixItHint::CreateInsertion(SrcExpr->getBeginLoc(), "[")
            << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
      }
      Diag(RelatedClass->getBeginLoc(), diag::note_declared_at);
      Diag(TDNDecl->getBeginLoc(), diag::note_declared_at);

      ExprResult msg =
        BuildInstanceMessageImplicit(SrcExpr, SrcType,
                                     InstanceMethod->getLocation(),
                                     InstanceMethod->getSelector(),
                                     InstanceMethod, None);
      SrcExpr = msg.get();
    }
    return true;
  }
}
return false;
4394}

4396Sema::ARCConversionResult
4397Sema::CheckObjCConversion(SourceRange castRange, QualType castType,
                        Expr *&castExpr, CheckedConversionKind CCK,
                        bool Diagnose, bool DiagnoseCFAudited,
                        BinaryOperatorKind Opc) {
QualType castExprType = castExpr->getType();

// For the purposes of the classification, we assume reference types
// will bind to temporaries.
QualType effCastType = castType;
if (const ReferenceType *ref = castType->getAs<ReferenceType>())
  effCastType = ref->getPointeeType();

ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
if (exprACTC == castACTC) {
  // Check for viability and report error if casting an rvalue to a
  // life-time qualifier.
  if (castACTC == ACTC_retainable &&
      (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
      castType != castExprType) {
    const Type *DT = castType.getTypePtr();
    QualType QDT = castType;
    // We desugar some types but not others. We ignore those
    // that cannot happen in a cast; i.e. auto, and those which
    // should not be de-sugared; i.e typedef.
    if (const ParenType *PT = dyn_cast<ParenType>(DT))
      QDT = PT->desugar();
    else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
      QDT = TP->desugar();
    else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
      QDT = AT->desugar();
    if (QDT != castType &&
        QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
      if (Diagnose) {
        SourceLocation loc = (castRange.isValid() ? castRange.getBegin()
                                                  : castExpr->getExprLoc());
        Diag(loc, diag::err_arc_nolifetime_behavior);
      }
      return ACR_error;
    }
  }
  return ACR_okay;
}

// The life-time qualifier cast check above is all we need for ObjCWeak.
// ObjCAutoRefCount has more restrictions on what is legal.
if (!getLangOpts().ObjCAutoRefCount)
  return ACR_okay;

if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;

// Allow all of these types to be cast to integer types (but not
// vice-versa).
if (castACTC == ACTC_none && castType->isIntegralType(Context))
  return ACR_okay;

// Allow casts between pointers to lifetime types (e.g., __strong id*)
// and pointers to void (e.g., cv void *). Casting from void* to lifetime*
// must be explicit.
if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
  return ACR_okay;
if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
    isCast(CCK))
  return ACR_okay;

switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
// For invalid casts, fall through.
case ACC_invalid:
  break;

// Do nothing for both bottom and +0.
case ACC_bottom:
case ACC_plusZero:
  return ACR_okay;

// If the result is +1, consume it here.
case ACC_plusOne:
  castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
                                      CK_ARCConsumeObject, castExpr, nullptr,
                                      VK_PRValue, FPOptionsOverride());
  Cleanup.setExprNeedsCleanups(true);
  return ACR_okay;
}

// If this is a non-implicit cast from id or block type to a
// CoreFoundation type, delay complaining in case the cast is used
// in an acceptable context.
if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) && isCast(CCK))
  return ACR_unbridged;

// Issue a diagnostic about a missing @-sign when implicit casting a cstring
// to 'NSString *', instead of falling through to report a "bridge cast"
// diagnostic.
if (castACTC == ACTC_retainable && exprACTC == ACTC_none &&
    CheckConversionToObjCLiteral(castType, castExpr, Diagnose))
  return ACR_error;

// Do not issue "bridge cast" diagnostic when implicit casting
// a retainable object to a CF type parameter belonging to an audited
// CF API function. Let caller issue a normal type mismatched diagnostic
// instead.
if ((!DiagnoseCFAudited || exprACTC != ACTC_retainable ||
     castACTC != ACTC_coreFoundation) &&
    !(exprACTC == ACTC_voidPtr && castACTC == ACTC_retainable &&
      (Opc == BO_NE || Opc == BO_EQ))) {
  if (Diagnose)
    diagnoseObjCARCConversion(*this, castRange, castType, castACTC, castExpr,
                              castExpr, exprACTC, CCK);
  return ACR_error;
}
return ACR_okay;
4508}

4510/// Given that we saw an expression with the ARCUnbridgedCastTy
4511/// placeholder type, complain bitterly.
4512void Sema::diagnoseARCUnbridgedCast(Expr *e) {
// We expect the spurious ImplicitCastExpr to already have been stripped.
assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((void)0);
CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());

SourceRange castRange;
QualType castType;
CheckedConversionKind CCK;

if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
  castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
  castType = cast->getTypeAsWritten();
  CCK = CCK_CStyleCast;
} else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
  castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
  castType = cast->getTypeAsWritten();
  CCK = CCK_OtherCast;
} else {
  llvm_unreachable("Unexpected ImplicitCastExpr")__builtin_unreachable();
}

ARCConversionTypeClass castACTC =
  classifyTypeForARCConversion(castType.getNonReferenceType());

Expr *castExpr = realCast->getSubExpr();
assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable)((void)0);

diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
                          castExpr, realCast, ACTC_retainable, CCK);
4541}

4543/// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
4544/// type, remove the placeholder cast.
4545Expr *Sema::stripARCUnbridgedCast(Expr *e) {
assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((void)0);

if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
  Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
  return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
} else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
  assert(uo->getOpcode() == UO_Extension)((void)0);
  Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
  return UnaryOperator::Create(Context, sub, UO_Extension, sub->getType(),
                               sub->getValueKind(), sub->getObjectKind(),
                               uo->getOperatorLoc(), false,
                               CurFPFeatureOverrides());
} else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
  assert(!gse->isResultDependent())((void)0);

  unsigned n = gse->getNumAssocs();
  SmallVector<Expr *, 4> subExprs;
  SmallVector<TypeSourceInfo *, 4> subTypes;
  subExprs.reserve(n);
  subTypes.reserve(n);
  for (const GenericSelectionExpr::Association assoc : gse->associations()) {
    subTypes.push_back(assoc.getTypeSourceInfo());
    Expr *sub = assoc.getAssociationExpr();
    if (assoc.isSelected())
      sub = stripARCUnbridgedCast(sub);
    subExprs.push_back(sub);
  }

  return GenericSelectionExpr::Create(
      Context, gse->getGenericLoc(), gse->getControllingExpr(), subTypes,
      subExprs, gse->getDefaultLoc(), gse->getRParenLoc(),
      gse->containsUnexpandedParameterPack(), gse->getResultIndex());
} else {
  assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!")((void)0);
  return cast<ImplicitCastExpr>(e)->getSubExpr();
}
4582}

4584bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
                                               QualType exprType) {
QualType canCastType =
  Context.getCanonicalType(castType).getUnqualifiedType();
QualType canExprType =
  Context.getCanonicalType(exprType).getUnqualifiedType();
if (isa<ObjCObjectPointerType>(canCastType) &&
    castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
    canExprType->isObjCObjectPointerType()) {
  if (const ObjCObjectPointerType *ObjT =
      canExprType->getAs<ObjCObjectPointerType>())
    if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
      return !ObjI->isArcWeakrefUnavailable();
}
return true;
4599}

4601/// Look for an ObjCReclaimReturnedObject cast and destroy it.
4602static Expr *maybeUndoReclaimObject(Expr *e) {
Expr *curExpr = e, *prevExpr = nullptr;

// Walk down the expression until we hit an implicit cast of kind
// ARCReclaimReturnedObject or an Expr that is neither a Paren nor a Cast.
while (true) {
  if (auto *pe = dyn_cast<ParenExpr>(curExpr)) {
    prevExpr = curExpr;
    curExpr = pe->getSubExpr();
    continue;
  }

  if (auto *ce = dyn_cast<CastExpr>(curExpr)) {
    if (auto *ice = dyn_cast<ImplicitCastExpr>(ce))
      if (ice->getCastKind() == CK_ARCReclaimReturnedObject) {
        if (!prevExpr)
          return ice->getSubExpr();
        if (auto *pe = dyn_cast<ParenExpr>(prevExpr))
          pe->setSubExpr(ice->getSubExpr());
        else
          cast<CastExpr>(prevExpr)->setSubExpr(ice->getSubExpr());
        return e;
      }

    prevExpr = curExpr;
    curExpr = ce->getSubExpr();
    continue;
  }

  // Break out of the loop if curExpr is neither a Paren nor a Cast.
  break;
}

return e;
4636}

4638ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
                                    ObjCBridgeCastKind Kind,
                                    SourceLocation BridgeKeywordLoc,
                                    TypeSourceInfo *TSInfo,
                                    Expr *SubExpr) {
ExprResult SubResult = UsualUnaryConversions(SubExpr);
if (SubResult.isInvalid()) return ExprError();
SubExpr = SubResult.get();

QualType T = TSInfo->getType();
QualType FromType = SubExpr->getType();

CastKind CK;

bool MustConsume = false;
if (T->isDependentType() || SubExpr->isTypeDependent()) {
  // Okay: we'll build a dependent expression type.
  CK = CK_Dependent;
} else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
  // Casting CF -> id
  CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
                                : CK_CPointerToObjCPointerCast);
  switch (Kind) {
  case OBC_Bridge:
    break;

  case OBC_BridgeRetained: {
    bool br = isKnownName("CFBridgingRelease");
    Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
      << 2
      << FromType
      << (T->isBlockPointerType()? 1 : 0)
      << T
      << SubExpr->getSourceRange()
      << Kind;
    Diag(BridgeKeywordLoc, diag::note_arc_bridge)
      << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
    Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
      << FromType << br
      << FixItHint::CreateReplacement(BridgeKeywordLoc,
                                      br ? "CFBridgingRelease "
                                         : "__bridge_transfer ");

    Kind = OBC_Bridge;
    break;
  }

  case OBC_BridgeTransfer:
    // We must consume the Objective-C object produced by the cast.
    MustConsume = true;
    break;
  }
} else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
  // Okay: id -> CF
  CK = CK_BitCast;
  switch (Kind) {
  case OBC_Bridge:
    // Reclaiming a value that's going to be __bridge-casted to CF
    // is very dangerous, so we don't do it.
    SubExpr = maybeUndoReclaimObject(SubExpr);
    break;

  case OBC_BridgeRetained:
    // Produce the object before casting it.
    SubExpr = ImplicitCastExpr::Create(Context, FromType, CK_ARCProduceObject,
                                       SubExpr, nullptr, VK_PRValue,
                                       FPOptionsOverride());
    break;

  case OBC_BridgeTransfer: {
    bool br = isKnownName("CFBridgingRetain");
    Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
      << (FromType->isBlockPointerType()? 1 : 0)
      << FromType
      << 2
      << T
      << SubExpr->getSourceRange()
      << Kind;

    Diag(BridgeKeywordLoc, diag::note_arc_bridge)
      << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
    Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
      << T << br
      << FixItHint::CreateReplacement(BridgeKeywordLoc,
                        br ? "CFBridgingRetain " : "__bridge_retained");

    Kind = OBC_Bridge;
    break;
  }
  }
} else {
  Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
    << FromType << T << Kind
    << SubExpr->getSourceRange()
    << TSInfo->getTypeLoc().getSourceRange();
  return ExprError();
}

Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
                                                 BridgeKeywordLoc,
                                                 TSInfo, SubExpr);

if (MustConsume) {
  Cleanup.setExprNeedsCleanups(true);
  Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
                                    nullptr, VK_PRValue, FPOptionsOverride());
}

return Result;
4747}

4749ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
                                    SourceLocation LParenLoc,
                                    ObjCBridgeCastKind Kind,
                                    SourceLocation BridgeKeywordLoc,
                                    ParsedType Type,
                                    SourceLocation RParenLoc,
                                    Expr *SubExpr) {
TypeSourceInfo *TSInfo = nullptr;
QualType T = GetTypeFromParser(Type, &TSInfo);
if (Kind == OBC_Bridge)
  CheckTollFreeBridgeCast(T, SubExpr);
if (!TSInfo)
  TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
                            SubExpr);
4764}

←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/Basic/SourceLocation.h

1//===- SourceLocation.h - Compact identifier for Source Files ---*- 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/// Defines the clang::SourceLocation class and associated facilities.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_CLANG_BASIC_SOURCELOCATION_H
15#define LLVM_CLANG_BASIC_SOURCELOCATION_H

17#include "clang/Basic/LLVM.h"
18#include "llvm/ADT/StringRef.h"
19#include <cassert>
20#include <cstdint>
21#include <string>
22#include <utility>

24namespace llvm {

26template <typename T> struct DenseMapInfo;

28class FoldingSetNodeID;
29template <typename T> struct FoldingSetTrait;

31} // namespace llvm

33namespace clang {

35class SourceManager;

37/// An opaque identifier used by SourceManager which refers to a
38/// source file (MemoryBuffer) along with its \#include path and \#line data.
39///
40class FileID {
/// A mostly-opaque identifier, where 0 is "invalid", >0 is
/// this module, and <-1 is something loaded from another module.
int ID = 0;

45public:
bool isValid() const { return ID != 0; }
bool isInvalid() const { return ID == 0; }

bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
bool operator>(const FileID &RHS) const { return RHS < *this; }
bool operator>=(const FileID &RHS) const { return RHS <= *this; }

static FileID getSentinel() { return get(-1); }
unsigned getHashValue() const { return static_cast<unsigned>(ID); }

59private:
friend class ASTWriter;
friend class ASTReader;
friend class SourceManager;

static FileID get(int V) {
  FileID F;
  F.ID = V;
  return F;
}

int getOpaqueValue() const { return ID; }
71};

73/// Encodes a location in the source. The SourceManager can decode this
74/// to get at the full include stack, line and column information.
75///
76/// Technically, a source location is simply an offset into the manager's view
77/// of the input source, which is all input buffers (including macro
78/// expansions) concatenated in an effectively arbitrary order. The manager
79/// actually maintains two blocks of input buffers. One, starting at offset
80/// 0 and growing upwards, contains all buffers from this module. The other,
81/// starting at the highest possible offset and growing downwards, contains
82/// buffers of loaded modules.
83///
84/// In addition, one bit of SourceLocation is used for quick access to the
85/// information whether the location is in a file or a macro expansion.
86///
87/// It is important that this type remains small. It is currently 32 bits wide.
88class SourceLocation {
friend class ASTReader;
friend class ASTWriter;
friend class SourceManager;
friend struct llvm::FoldingSetTrait<SourceLocation>;

94public:
using UIntTy = uint32_t;
using IntTy = int32_t;

98private:
UIntTy ID = 0;

enum : UIntTy { MacroIDBit = 1ULL << (8 * sizeof(UIntTy) - 1) };

103public:
bool isFileID() const  { return (ID & MacroIDBit) == 0; }
bool isMacroID() const { return (ID & MacroIDBit) != 0; }

/// Return true if this is a valid SourceLocation object.
///
/// Invalid SourceLocations are often used when events have no corresponding
/// location in the source (e.g. a diagnostic is required for a command line
/// option).
bool isValid() const { return ID != 0; }
11
←
Assuming field 'ID' is equal to 0→
12
←
Returning zero, which participates in a condition later→
bool isInvalid() const { return ID == 0; }

115private:
/// Return the offset into the manager's global input view.
UIntTy getOffset() const { return ID & ~MacroIDBit; }

static SourceLocation getFileLoc(UIntTy ID) {
  assert((ID & MacroIDBit) == 0 && "Ran out of source locations!")((void)0);
  SourceLocation L;
  L.ID = ID;
  return L;
}

static SourceLocation getMacroLoc(UIntTy ID) {
  assert((ID & MacroIDBit) == 0 && "Ran out of source locations!")((void)0);
  SourceLocation L;
  L.ID = MacroIDBit | ID;
  return L;
}

133public:
/// Return a source location with the specified offset from this
/// SourceLocation.
SourceLocation getLocWithOffset(IntTy Offset) const {
  assert(((getOffset()+Offset) & MacroIDBit) == 0 && "offset overflow")((void)0);
  SourceLocation L;
  L.ID = ID+Offset;
  return L;
}

/// When a SourceLocation itself cannot be used, this returns
/// an (opaque) 32-bit integer encoding for it.
///
/// This should only be passed to SourceLocation::getFromRawEncoding, it
/// should not be inspected directly.
UIntTy getRawEncoding() const { return ID; }

/// Turn a raw encoding of a SourceLocation object into
/// a real SourceLocation.
///
/// \see getRawEncoding.
static SourceLocation getFromRawEncoding(UIntTy Encoding) {
  SourceLocation X;
  X.ID = Encoding;
  return X;
}

/// When a SourceLocation itself cannot be used, this returns
/// an (opaque) pointer encoding for it.
///
/// This should only be passed to SourceLocation::getFromPtrEncoding, it
/// should not be inspected directly.
void* getPtrEncoding() const {
  // Double cast to avoid a warning "cast to pointer from integer of different
  // size".
  return (void*)(uintptr_t)getRawEncoding();
}

/// Turn a pointer encoding of a SourceLocation object back
/// into a real SourceLocation.
static SourceLocation getFromPtrEncoding(const void *Encoding) {
  return getFromRawEncoding((SourceLocation::UIntTy)(uintptr_t)Encoding);
}

static bool isPairOfFileLocations(SourceLocation Start, SourceLocation End) {
  return Start.isValid() && Start.isFileID() && End.isValid() &&
         End.isFileID();
}

unsigned getHashValue() const;
void print(raw_ostream &OS, const SourceManager &SM) const;
std::string printToString(const SourceManager &SM) const;
void dump(const SourceManager &SM) const;
186};

188inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
return LHS.getRawEncoding() == RHS.getRawEncoding();
190}

192inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
return !(LHS == RHS);
194}

196// Ordering is meaningful only if LHS and RHS have the same FileID!
197// Otherwise use SourceManager::isBeforeInTranslationUnit().
198inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
return LHS.getRawEncoding() < RHS.getRawEncoding();
200}
201inline bool operator>(const SourceLocation &LHS, const SourceLocation &RHS) {
return LHS.getRawEncoding() > RHS.getRawEncoding();
203}
204inline bool operator<=(const SourceLocation &LHS, const SourceLocation &RHS) {
return LHS.getRawEncoding() <= RHS.getRawEncoding();
206}
207inline bool operator>=(const SourceLocation &LHS, const SourceLocation &RHS) {
return LHS.getRawEncoding() >= RHS.getRawEncoding();
209}

211/// A trivial tuple used to represent a source range.
212class SourceRange {
SourceLocation B;
SourceLocation E;

216public:
SourceRange() = default;
SourceRange(SourceLocation loc) : B(loc), E(loc) {}
SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}

SourceLocation getBegin() const { return B; }
SourceLocation getEnd() const { return E; }

void setBegin(SourceLocation b) { B = b; }
void setEnd(SourceLocation e) { E = e; }

bool isValid() const { return B.isValid() && E.isValid(); }
bool isInvalid() const { return !isValid(); }

bool operator==(const SourceRange &X) const {
  return B == X.B && E == X.E;
}

bool operator!=(const SourceRange &X) const {
  return B != X.B || E != X.E;
}

// Returns true iff other is wholly contained within this range.
bool fullyContains(const SourceRange &other) const {
  return B <= other.B && E >= other.E;
}

void print(raw_ostream &OS, const SourceManager &SM) const;
std::string printToString(const SourceManager &SM) const;
void dump(const SourceManager &SM) const;
246};

248/// Represents a character-granular source range.
249///
250/// The underlying SourceRange can either specify the starting/ending character
251/// of the range, or it can specify the start of the range and the start of the
252/// last token of the range (a "token range").  In the token range case, the
253/// size of the last token must be measured to determine the actual end of the
254/// range.
255class CharSourceRange {
SourceRange Range;
bool IsTokenRange = false;

259public:
CharSourceRange() = default;
CharSourceRange(SourceRange R, bool ITR) : Range(R), IsTokenRange(ITR) {}

static CharSourceRange getTokenRange(SourceRange R) {
  return CharSourceRange(R, true);
}

static CharSourceRange getCharRange(SourceRange R) {
  return CharSourceRange(R, false);
}

static CharSourceRange getTokenRange(SourceLocation B, SourceLocation E) {
  return getTokenRange(SourceRange(B, E));
}

static CharSourceRange getCharRange(SourceLocation B, SourceLocation E) {
  return getCharRange(SourceRange(B, E));
}

/// Return true if the end of this range specifies the start of
/// the last token.  Return false if the end of this range specifies the last
/// character in the range.
bool isTokenRange() const { return IsTokenRange; }
bool isCharRange() const { return !IsTokenRange; }

SourceLocation getBegin() const { return Range.getBegin(); }
SourceLocation getEnd() const { return Range.getEnd(); }
SourceRange getAsRange() const { return Range; }

void setBegin(SourceLocation b) { Range.setBegin(b); }
void setEnd(SourceLocation e) { Range.setEnd(e); }
void setTokenRange(bool TR) { IsTokenRange = TR; }

bool isValid() const { return Range.isValid(); }
bool isInvalid() const { return !isValid(); }
295};

297/// Represents an unpacked "presumed" location which can be presented
298/// to the user.
299///
300/// A 'presumed' location can be modified by \#line and GNU line marker
301/// directives and is always the expansion point of a normal location.
302///
303/// You can get a PresumedLoc from a SourceLocation with SourceManager.
304class PresumedLoc {
const char *Filename = nullptr;
FileID ID;
unsigned Line, Col;
SourceLocation IncludeLoc;

310public:
PresumedLoc() = default;
PresumedLoc(const char *FN, FileID FID, unsigned Ln, unsigned Co,
            SourceLocation IL)
    : Filename(FN), ID(FID), Line(Ln), Col(Co), IncludeLoc(IL) {}

/// Return true if this object is invalid or uninitialized.
///
/// This occurs when created with invalid source locations or when walking
/// off the top of a \#include stack.
bool isInvalid() const { return Filename == nullptr; }
bool isValid() const { return Filename != nullptr; }

/// Return the presumed filename of this location.
///
/// This can be affected by \#line etc.
const char *getFilename() const {
  assert(isValid())((void)0);
  return Filename;
}

FileID getFileID() const {
  assert(isValid())((void)0);
  return ID;
}

/// Return the presumed line number of this location.
///
/// This can be affected by \#line etc.
unsigned getLine() const {
  assert(isValid())((void)0);
  return Line;
}

/// Return the presumed column number of this location.
///
/// This cannot be affected by \#line, but is packaged here for convenience.
unsigned getColumn() const {
  assert(isValid())((void)0);
  return Col;
}

/// Return the presumed include location of this location.
///
/// This can be affected by GNU linemarker directives.
SourceLocation getIncludeLoc() const {
  assert(isValid())((void)0);
  return IncludeLoc;
}
359};

361class FileEntry;

363/// A SourceLocation and its associated SourceManager.
364///
365/// This is useful for argument passing to functions that expect both objects.
366class FullSourceLoc : public SourceLocation {
const SourceManager *SrcMgr = nullptr;

369public:
/// Creates a FullSourceLoc where isValid() returns \c false.
FullSourceLoc() = default;

explicit FullSourceLoc(SourceLocation Loc, const SourceManager &SM)
    : SourceLocation(Loc), SrcMgr(&SM) {}

bool hasManager() const {
    bool hasSrcMgr =  SrcMgr != nullptr;
    assert(hasSrcMgr == isValid() && "FullSourceLoc has location but no manager")((void)0);
    return hasSrcMgr;
}

/// \pre This FullSourceLoc has an associated SourceManager.
const SourceManager &getManager() const {
  assert(SrcMgr && "SourceManager is NULL.")((void)0);
  return *SrcMgr;
}

FileID getFileID() const;

FullSourceLoc getExpansionLoc() const;
FullSourceLoc getSpellingLoc() const;
FullSourceLoc getFileLoc() const;
PresumedLoc getPresumedLoc(bool UseLineDirectives = true) const;
bool isMacroArgExpansion(FullSourceLoc *StartLoc = nullptr) const;
FullSourceLoc getImmediateMacroCallerLoc() const;
std::pair<FullSourceLoc, StringRef> getModuleImportLoc() const;
unsigned getFileOffset() const;

unsigned getExpansionLineNumber(bool *Invalid = nullptr) const;
unsigned getExpansionColumnNumber(bool *Invalid = nullptr) const;

unsigned getSpellingLineNumber(bool *Invalid = nullptr) const;
unsigned getSpellingColumnNumber(bool *Invalid = nullptr) const;

const char *getCharacterData(bool *Invalid = nullptr) const;

unsigned getLineNumber(bool *Invalid = nullptr) const;
unsigned getColumnNumber(bool *Invalid = nullptr) const;

const FileEntry *getFileEntry() const;

/// Return a StringRef to the source buffer data for the
/// specified FileID.
StringRef getBufferData(bool *Invalid = nullptr) const;

/// Decompose the specified location into a raw FileID + Offset pair.
///
/// The first element is the FileID, the second is the offset from the
/// start of the buffer of the location.
std::pair<FileID, unsigned> getDecomposedLoc() const;

bool isInSystemHeader() const;

/// Determines the order of 2 source locations in the translation unit.
///
/// \returns true if this source location comes before 'Loc', false otherwise.
bool isBeforeInTranslationUnitThan(SourceLocation Loc) const;

/// Determines the order of 2 source locations in the translation unit.
///
/// \returns true if this source location comes before 'Loc', false otherwise.
bool isBeforeInTranslationUnitThan(FullSourceLoc Loc) const {
  assert(Loc.isValid())((void)0);
  assert(SrcMgr == Loc.SrcMgr && "Loc comes from another SourceManager!")((void)0);
  return isBeforeInTranslationUnitThan((SourceLocation)Loc);
}

/// Comparison function class, useful for sorting FullSourceLocs.
struct BeforeThanCompare {
  bool operator()(const FullSourceLoc& lhs, const FullSourceLoc& rhs) const {
    return lhs.isBeforeInTranslationUnitThan(rhs);
  }
};

/// Prints information about this FullSourceLoc to stderr.
///
/// This is useful for debugging.
void dump() const;

friend bool
operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
  return LHS.getRawEncoding() == RHS.getRawEncoding() &&
        LHS.SrcMgr == RHS.SrcMgr;
}

friend bool
operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
  return !(LHS == RHS);
}
460};

462} // namespace clang

464namespace llvm {

/// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
/// DenseSets.
template <>
struct DenseMapInfo<clang::FileID> {
  static clang::FileID getEmptyKey() {
    return {};
  }

  static clang::FileID getTombstoneKey() {
    return clang::FileID::getSentinel();
  }

  static unsigned getHashValue(clang::FileID S) {
    return S.getHashValue();
  }

  static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
    return LHS == RHS;
  }
};

/// Define DenseMapInfo so that SourceLocation's can be used as keys in
/// DenseMap and DenseSet. This trait class is eqivalent to
/// DenseMapInfo<unsigned> which uses SourceLocation::ID is used as a key.
template <> struct DenseMapInfo<clang::SourceLocation> {
  static clang::SourceLocation getEmptyKey() {
    constexpr clang::SourceLocation::UIntTy Zero = 0;
    return clang::SourceLocation::getFromRawEncoding(~Zero);
  }

  static clang::SourceLocation getTombstoneKey() {
    constexpr clang::SourceLocation::UIntTy Zero = 0;
    return clang::SourceLocation::getFromRawEncoding(~Zero - 1);
  }

  static unsigned getHashValue(clang::SourceLocation Loc) {
    return Loc.getHashValue();
  }

  static bool isEqual(clang::SourceLocation LHS, clang::SourceLocation RHS) {
    return LHS == RHS;
  }
};

// Allow calling FoldingSetNodeID::Add with SourceLocation object as parameter
template <> struct FoldingSetTrait<clang::SourceLocation> {
  static void Profile(const clang::SourceLocation &X, FoldingSetNodeID &ID);
};

515} // namespace llvm

517#endif // LLVM_CLANG_BASIC_SOURCELOCATION_H