contrib/llvm/tools/clang/lib/Sema/SemaExprObjC.cpp

   1 //===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  This file implements semantic analysis for Objective-C expressions.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Sema/SemaInternal.h"
  15 #include "clang/AST/ASTContext.h"
  16 #include "clang/AST/DeclObjC.h"
  17 #include "clang/AST/ExprObjC.h"
  18 #include "clang/AST/StmtVisitor.h"
  19 #include "clang/AST/TypeLoc.h"
  20 #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
  21 #include "clang/Edit/Commit.h"
  22 #include "clang/Edit/Rewriters.h"
  23 #include "clang/Lex/Preprocessor.h"
  24 #include "clang/Sema/Initialization.h"
  25 #include "clang/Sema/Lookup.h"
  26 #include "clang/Sema/Scope.h"
  27 #include "clang/Sema/ScopeInfo.h"
  28 #include "llvm/ADT/SmallString.h"
  29
  30 using namespace clang;
  31 using namespace sema;
  32 using llvm::makeArrayRef;
  33
  34 ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
  35                                         ArrayRef<Expr *> Strings) {
  36   // Most ObjC strings are formed out of a single piece.  However, we *can*
  37   // have strings formed out of multiple @ strings with multiple pptokens in
  38   // each one, e.g. @"foo" "bar" @"baz" "qux"   which need to be turned into one
  39   // StringLiteral for ObjCStringLiteral to hold onto.
  40   StringLiteral *S = cast<StringLiteral>(Strings[0]);
  41
  42   // If we have a multi-part string, merge it all together.
  43   if (Strings.size() != 1) {
  44     // Concatenate objc strings.
  45     SmallString<128> StrBuf;
  46     SmallVector<SourceLocation, 8> StrLocs;
  47
  48     for (Expr *E : Strings) {
  49       S = cast<StringLiteral>(E);
  50
  51       // ObjC strings can't be wide or UTF.
  52       if (!S->isAscii()) {
  53         Diag(S->getLocStart(), diag::err_cfstring_literal_not_string_constant)
  54           << S->getSourceRange();
  55         return true;
  56       }
  57
  58       // Append the string.
  59       StrBuf += S->getString();
  60
  61       // Get the locations of the string tokens.
  62       StrLocs.append(S->tokloc_begin(), S->tokloc_end());
  63     }
  64
  65     // Create the aggregate string with the appropriate content and location
  66     // information.
  67     const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType());
  68     assert(CAT && "String literal not of constant array type!");
  69     QualType StrTy = Context.getConstantArrayType(
  70         CAT->getElementType(), llvm::APInt(32, StrBuf.size() + 1),
  71         CAT->getSizeModifier(), CAT->getIndexTypeCVRQualifiers());
  72     S = StringLiteral::Create(Context, StrBuf, StringLiteral::Ascii,
  73                               /*Pascal=*/false, StrTy, &StrLocs[0],
  74                               StrLocs.size());
  75   }
  76
  77   return BuildObjCStringLiteral(AtLocs[0], S);
  78 }
  79
  80 ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
  81   // Verify that this composite string is acceptable for ObjC strings.
  82   if (CheckObjCString(S))
  83     return true;
  84
  85   // Initialize the constant string interface lazily. This assumes
  86   // the NSString interface is seen in this translation unit. Note: We
  87   // don't use NSConstantString, since the runtime team considers this
  88   // interface private (even though it appears in the header files).
  89   QualType Ty = Context.getObjCConstantStringInterface();
  90   if (!Ty.isNull()) {
  91     Ty = Context.getObjCObjectPointerType(Ty);
  92   } else if (getLangOpts().NoConstantCFStrings) {
  93     IdentifierInfo *NSIdent=nullptr;
  94     std::string StringClass(getLangOpts().ObjCConstantStringClass);
  95
  96     if (StringClass.empty())
  97       NSIdent = &Context.Idents.get("NSConstantString");
  98     else
  99       NSIdent = &Context.Idents.get(StringClass);
 100
 101     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
 102                                      LookupOrdinaryName);
 103     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
 104       Context.setObjCConstantStringInterface(StrIF);
 105       Ty = Context.getObjCConstantStringInterface();
 106       Ty = Context.getObjCObjectPointerType(Ty);
 107     } else {
 108       // If there is no NSConstantString interface defined then treat this
 109       // as error and recover from it.
 110       Diag(S->getLocStart(), diag::err_no_nsconstant_string_class) << NSIdent
 111         << S->getSourceRange();
 112       Ty = Context.getObjCIdType();
 113     }
 114   } else {
 115     IdentifierInfo *NSIdent = NSAPIObj->getNSClassId(NSAPI::ClassId_NSString);
 116     NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
 117                                      LookupOrdinaryName);
 118     if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
 119       Context.setObjCConstantStringInterface(StrIF);
 120       Ty = Context.getObjCConstantStringInterface();
 121       Ty = Context.getObjCObjectPointerType(Ty);
 122     } else {
 123       // If there is no NSString interface defined, implicitly declare
 124       // a @class NSString; and use that instead. This is to make sure
 125       // type of an NSString literal is represented correctly, instead of
 126       // being an 'id' type.
 127       Ty = Context.getObjCNSStringType();
 128       if (Ty.isNull()) {
 129         ObjCInterfaceDecl *NSStringIDecl =
 130           ObjCInterfaceDecl::Create (Context,
 131                                      Context.getTranslationUnitDecl(),
 132                                      SourceLocation(), NSIdent,
 133                                      nullptr, nullptr, SourceLocation());
 134         Ty = Context.getObjCInterfaceType(NSStringIDecl);
 135         Context.setObjCNSStringType(Ty);
 136       }
 137       Ty = Context.getObjCObjectPointerType(Ty);
 138     }
 139   }
 140
 141   return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
 142 }
 143
 144 /// \brief Emits an error if the given method does not exist, or if the return
 145 /// type is not an Objective-C object.
 146 static bool validateBoxingMethod(Sema &S, SourceLocation Loc,
 147                                  const ObjCInterfaceDecl *Class,
 148                                  Selector Sel, const ObjCMethodDecl *Method) {
 149   if (!Method) {
 150     // FIXME: Is there a better way to avoid quotes than using getName()?
 151     S.Diag(Loc, diag::err_undeclared_boxing_method) << Sel << Class->getName();
 152     return false;
 153   }
 154
 155   // Make sure the return type is reasonable.
 156   QualType ReturnType = Method->getReturnType();
 157   if (!ReturnType->isObjCObjectPointerType()) {
 158     S.Diag(Loc, diag::err_objc_literal_method_sig)
 159       << Sel;
 160     S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
 161       << ReturnType;
 162     return false;
 163   }
 164
 165   return true;
 166 }
 167
 168 /// \brief Maps ObjCLiteralKind to NSClassIdKindKind
 169 static NSAPI::NSClassIdKindKind ClassKindFromLiteralKind(
 170                                             Sema::ObjCLiteralKind LiteralKind) {
 171   switch (LiteralKind) {
 172     case Sema::LK_Array:
 173       return NSAPI::ClassId_NSArray;
 174     case Sema::LK_Dictionary:
 175       return NSAPI::ClassId_NSDictionary;
 176     case Sema::LK_Numeric:
 177       return NSAPI::ClassId_NSNumber;
 178     case Sema::LK_String:
 179       return NSAPI::ClassId_NSString;
 180     case Sema::LK_Boxed:
 181       return NSAPI::ClassId_NSValue;
 182
 183     // there is no corresponding matching
 184     // between LK_None/LK_Block and NSClassIdKindKind
 185     case Sema::LK_Block:
 186     case Sema::LK_None:
 187       break;
 188   }
 189   llvm_unreachable("LiteralKind can't be converted into a ClassKind");
 190 }
 191
 192 /// \brief Validates ObjCInterfaceDecl availability.
 193 /// ObjCInterfaceDecl, used to create ObjC literals, should be defined
 194 /// if clang not in a debugger mode.
 195 static bool ValidateObjCLiteralInterfaceDecl(Sema &S, ObjCInterfaceDecl *Decl,
 196                                             SourceLocation Loc,
 197                                             Sema::ObjCLiteralKind LiteralKind) {
 198   if (!Decl) {
 199     NSAPI::NSClassIdKindKind Kind = ClassKindFromLiteralKind(LiteralKind);
 200     IdentifierInfo *II = S.NSAPIObj->getNSClassId(Kind);
 201     S.Diag(Loc, diag::err_undeclared_objc_literal_class)
 202       << II->getName() << LiteralKind;
 203     return false;
 204   } else if (!Decl->hasDefinition() && !S.getLangOpts().DebuggerObjCLiteral) {
 205     S.Diag(Loc, diag::err_undeclared_objc_literal_class)
 206       << Decl->getName() << LiteralKind;
 207     S.Diag(Decl->getLocation(), diag::note_forward_class);
 208     return false;
 209   }
 210
 211   return true;
 212 }
 213
 214 /// \brief Looks up ObjCInterfaceDecl of a given NSClassIdKindKind.
 215 /// Used to create ObjC literals, such as NSDictionary (@{}),
 216 /// NSArray (@[]) and Boxed Expressions (@())
 217 static ObjCInterfaceDecl *LookupObjCInterfaceDeclForLiteral(Sema &S,
 218                                             SourceLocation Loc,
 219                                             Sema::ObjCLiteralKind LiteralKind) {
 220   NSAPI::NSClassIdKindKind ClassKind = ClassKindFromLiteralKind(LiteralKind);
 221   IdentifierInfo *II = S.NSAPIObj->getNSClassId(ClassKind);
 222   NamedDecl *IF = S.LookupSingleName(S.TUScope, II, Loc,
 223                                      Sema::LookupOrdinaryName);
 224   ObjCInterfaceDecl *ID = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
 225   if (!ID && S.getLangOpts().DebuggerObjCLiteral) {
 226     ASTContext &Context = S.Context;
 227     TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
 228     ID = ObjCInterfaceDecl::Create (Context, TU, SourceLocation(), II,
 229                                     nullptr, nullptr, SourceLocation());
 230   }
 231
 232   if (!ValidateObjCLiteralInterfaceDecl(S, ID, Loc, LiteralKind)) {
 233     ID = nullptr;
 234   }
 235
 236   return ID;
 237 }
 238
 239 /// \brief Retrieve the NSNumber factory method that should be used to create
 240 /// an Objective-C literal for the given type.
 241 static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
 242                                                 QualType NumberType,
 243                                                 bool isLiteral = false,
 244                                                 SourceRange R = SourceRange()) {
 245   Optional<NSAPI::NSNumberLiteralMethodKind> Kind =
 246       S.NSAPIObj->getNSNumberFactoryMethodKind(NumberType);
 247
 248   if (!Kind) {
 249     if (isLiteral) {
 250       S.Diag(Loc, diag::err_invalid_nsnumber_type)
 251         << NumberType << R;
 252     }
 253     return nullptr;
 254   }
 255
 256   // If we already looked up this method, we're done.
 257   if (S.NSNumberLiteralMethods[*Kind])
 258     return S.NSNumberLiteralMethods[*Kind];
 259
 260   Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
 261                                                         /*Instance=*/false);
 262
 263   ASTContext &CX = S.Context;
 264
 265   // Look up the NSNumber class, if we haven't done so already. It's cached
 266   // in the Sema instance.
 267   if (!S.NSNumberDecl) {
 268     S.NSNumberDecl = LookupObjCInterfaceDeclForLiteral(S, Loc,
 269                                                        Sema::LK_Numeric);
 270     if (!S.NSNumberDecl) {
 271       return nullptr;
 272     }
 273   }
 274
 275   if (S.NSNumberPointer.isNull()) {
 276     // generate the pointer to NSNumber type.
 277     QualType NSNumberObject = CX.getObjCInterfaceType(S.NSNumberDecl);
 278     S.NSNumberPointer = CX.getObjCObjectPointerType(NSNumberObject);
 279   }
 280
 281   // Look for the appropriate method within NSNumber.
 282   ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);
 283   if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
 284     // create a stub definition this NSNumber factory method.
 285     TypeSourceInfo *ReturnTInfo = nullptr;
 286     Method =
 287         ObjCMethodDecl::Create(CX, SourceLocation(), SourceLocation(), Sel,
 288                                S.NSNumberPointer, ReturnTInfo, S.NSNumberDecl,
 289                                /*isInstance=*/false, /*isVariadic=*/false,
 290                                /*isPropertyAccessor=*/false,
 291                                /*isImplicitlyDeclared=*/true,
 292                                /*isDefined=*/false, ObjCMethodDecl::Required,
 293                                /*HasRelatedResultType=*/false);
 294     ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
 295                                              SourceLocation(), SourceLocation(),
 296                                              &CX.Idents.get("value"),
 297                                              NumberType, /*TInfo=*/nullptr,
 298                                              SC_None, nullptr);
 299     Method->setMethodParams(S.Context, value, None);
 300   }
 301
 302   if (!validateBoxingMethod(S, Loc, S.NSNumberDecl, Sel, Method))
 303     return nullptr;
 304
 305   // Note: if the parameter type is out-of-line, we'll catch it later in the
 306   // implicit conversion.
 307
 308   S.NSNumberLiteralMethods[*Kind] = Method;
 309   return Method;
 310 }
 311
 312 /// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
 313 /// numeric literal expression. Type of the expression will be "NSNumber *".
 314 ExprResult Sema::BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number) {
 315   // Determine the type of the literal.
 316   QualType NumberType = Number->getType();
 317   if (CharacterLiteral *Char = dyn_cast<CharacterLiteral>(Number)) {
 318     // In C, character literals have type 'int'. That's not the type we want
 319     // to use to determine the Objective-c literal kind.
 320     switch (Char->getKind()) {
 321     case CharacterLiteral::Ascii:
 322     case CharacterLiteral::UTF8:
 323       NumberType = Context.CharTy;
 324       break;
 325
 326     case CharacterLiteral::Wide:
 327       NumberType = Context.getWideCharType();
 328       break;
 329
 330     case CharacterLiteral::UTF16:
 331       NumberType = Context.Char16Ty;
 332       break;
 333
 334     case CharacterLiteral::UTF32:
 335       NumberType = Context.Char32Ty;
 336       break;
 337     }
 338   }
 339
 340   // Look for the appropriate method within NSNumber.
 341   // Construct the literal.
 342   SourceRange NR(Number->getSourceRange());
 343   ObjCMethodDecl *Method = getNSNumberFactoryMethod(*this, AtLoc, NumberType,
 344                                                     true, NR);
 345   if (!Method)
 346     return ExprError();
 347
 348   // Convert the number to the type that the parameter expects.
 349   ParmVarDecl *ParamDecl = Method->parameters()[0];
 350   InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
 351                                                                     ParamDecl);
 352   ExprResult ConvertedNumber = PerformCopyInitialization(Entity,
 353                                                          SourceLocation(),
 354                                                          Number);
 355   if (ConvertedNumber.isInvalid())
 356     return ExprError();
 357   Number = ConvertedNumber.get();
 358
 359   // Use the effective source range of the literal, including the leading '@'.
 360   return MaybeBindToTemporary(
 361            new (Context) ObjCBoxedExpr(Number, NSNumberPointer, Method,
 362                                        SourceRange(AtLoc, NR.getEnd())));
 363 }
 364
 365 ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation AtLoc,
 366                                       SourceLocation ValueLoc,
 367                                       bool Value) {
 368   ExprResult Inner;
 369   if (getLangOpts().CPlusPlus) {
 370     Inner = ActOnCXXBoolLiteral(ValueLoc, Value? tok::kw_true : tok::kw_false);
 371   } else {
 372     // C doesn't actually have a way to represent literal values of type
 373     // _Bool. So, we'll use 0/1 and implicit cast to _Bool.
 374     Inner = ActOnIntegerConstant(ValueLoc, Value? 1 : 0);
 375     Inner = ImpCastExprToType(Inner.get(), Context.BoolTy,
 376                               CK_IntegralToBoolean);
 377   }
 378
 379   return BuildObjCNumericLiteral(AtLoc, Inner.get());
 380 }
 381
 382 /// \brief Check that the given expression is a valid element of an Objective-C
 383 /// collection literal.
 384 static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element,
 385                                                     QualType T,
 386                                                     bool ArrayLiteral = false) {
 387   // If the expression is type-dependent, there's nothing for us to do.
 388   if (Element->isTypeDependent())
 389     return Element;
 390
 391   ExprResult Result = S.CheckPlaceholderExpr(Element);
 392   if (Result.isInvalid())
 393     return ExprError();
 394   Element = Result.get();
 395
 396   // In C++, check for an implicit conversion to an Objective-C object pointer
 397   // type.
 398   if (S.getLangOpts().CPlusPlus && Element->getType()->isRecordType()) {
 399     InitializedEntity Entity
 400       = InitializedEntity::InitializeParameter(S.Context, T,
 401                                                /*Consumed=*/false);
 402     InitializationKind Kind
 403       = InitializationKind::CreateCopy(Element->getLocStart(),
 404                                        SourceLocation());
 405     InitializationSequence Seq(S, Entity, Kind, Element);
 406     if (!Seq.Failed())
 407       return Seq.Perform(S, Entity, Kind, Element);
 408   }
 409
 410   Expr *OrigElement = Element;
 411
 412   // Perform lvalue-to-rvalue conversion.
 413   Result = S.DefaultLvalueConversion(Element);
 414   if (Result.isInvalid())
 415     return ExprError();
 416   Element = Result.get();
 417
 418   // Make sure that we have an Objective-C pointer type or block.
 419   if (!Element->getType()->isObjCObjectPointerType() &&
 420       !Element->getType()->isBlockPointerType()) {
 421     bool Recovered = false;
 422
 423     // If this is potentially an Objective-C numeric literal, add the '@'.
 424     if (isa<IntegerLiteral>(OrigElement) ||
 425         isa<CharacterLiteral>(OrigElement) ||
 426         isa<FloatingLiteral>(OrigElement) ||
 427         isa<ObjCBoolLiteralExpr>(OrigElement) ||
 428         isa<CXXBoolLiteralExpr>(OrigElement)) {
 429       if (S.NSAPIObj->getNSNumberFactoryMethodKind(OrigElement->getType())) {
 430         int Which = isa<CharacterLiteral>(OrigElement) ? 1
 431                   : (isa<CXXBoolLiteralExpr>(OrigElement) ||
 432                      isa<ObjCBoolLiteralExpr>(OrigElement)) ? 2
 433                   : 3;
 434
 435         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
 436           << Which << OrigElement->getSourceRange()
 437           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
 438
 439         Result = S.BuildObjCNumericLiteral(OrigElement->getLocStart(),
 440                                            OrigElement);
 441         if (Result.isInvalid())
 442           return ExprError();
 443
 444         Element = Result.get();
 445         Recovered = true;
 446       }
 447     }
 448     // If this is potentially an Objective-C string literal, add the '@'.
 449     else if (StringLiteral *String = dyn_cast<StringLiteral>(OrigElement)) {
 450       if (String->isAscii()) {
 451         S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
 452           << 0 << OrigElement->getSourceRange()
 453           << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
 454
 455         Result = S.BuildObjCStringLiteral(OrigElement->getLocStart(), String);
 456         if (Result.isInvalid())
 457           return ExprError();
 458
 459         Element = Result.get();
 460         Recovered = true;
 461       }
 462     }
 463
 464     if (!Recovered) {
 465       S.Diag(Element->getLocStart(), diag::err_invalid_collection_element)
 466         << Element->getType();
 467       return ExprError();
 468     }
 469   }
 470   if (ArrayLiteral)
 471     if (ObjCStringLiteral *getString =
 472           dyn_cast<ObjCStringLiteral>(OrigElement)) {
 473       if (StringLiteral *SL = getString->getString()) {
 474         unsigned numConcat = SL->getNumConcatenated();
 475         if (numConcat > 1) {
 476           // Only warn if the concatenated string doesn't come from a macro.
 477           bool hasMacro = false;
 478           for (unsigned i = 0; i < numConcat ; ++i)
 479             if (SL->getStrTokenLoc(i).isMacroID()) {
 480               hasMacro = true;
 481               break;
 482             }
 483           if (!hasMacro)
 484             S.Diag(Element->getLocStart(),
 485                    diag::warn_concatenated_nsarray_literal)
 486               << Element->getType();
 487         }
 488       }
 489     }
 490
 491   // Make sure that the element has the type that the container factory
 492   // function expects.
 493   return S.PerformCopyInitialization(
 494            InitializedEntity::InitializeParameter(S.Context, T,
 495                                                   /*Consumed=*/false),
 496            Element->getLocStart(), Element);
 497 }
 498
 499 ExprResult Sema::BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr) {
 500   if (ValueExpr->isTypeDependent()) {
 501     ObjCBoxedExpr *BoxedExpr =
 502       new (Context) ObjCBoxedExpr(ValueExpr, Context.DependentTy, nullptr, SR);
 503     return BoxedExpr;
 504   }
 505   ObjCMethodDecl *BoxingMethod = nullptr;
 506   QualType BoxedType;
 507   // Convert the expression to an RValue, so we can check for pointer types...
 508   ExprResult RValue = DefaultFunctionArrayLvalueConversion(ValueExpr);
 509   if (RValue.isInvalid()) {
 510     return ExprError();
 511   }
 512   SourceLocation Loc = SR.getBegin();
 513   ValueExpr = RValue.get();
 514   QualType ValueType(ValueExpr->getType());
 515   if (const PointerType *PT = ValueType->getAs<PointerType>()) {
 516     QualType PointeeType = PT->getPointeeType();
 517     if (Context.hasSameUnqualifiedType(PointeeType, Context.CharTy)) {
 518
 519       if (!NSStringDecl) {
 520         NSStringDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
 521                                                          Sema::LK_String);
 522         if (!NSStringDecl) {
 523           return ExprError();
 524         }
 525         QualType NSStringObject = Context.getObjCInterfaceType(NSStringDecl);
 526         NSStringPointer = Context.getObjCObjectPointerType(NSStringObject);
 527       }
 528
 529       if (!StringWithUTF8StringMethod) {
 530         IdentifierInfo *II = &Context.Idents.get("stringWithUTF8String");
 531         Selector stringWithUTF8String = Context.Selectors.getUnarySelector(II);
 532
 533         // Look for the appropriate method within NSString.
 534         BoxingMethod = NSStringDecl->lookupClassMethod(stringWithUTF8String);
 535         if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
 536           // Debugger needs to work even if NSString hasn't been defined.
 537           TypeSourceInfo *ReturnTInfo = nullptr;
 538           ObjCMethodDecl *M = ObjCMethodDecl::Create(
 539               Context, SourceLocation(), SourceLocation(), stringWithUTF8String,
 540               NSStringPointer, ReturnTInfo, NSStringDecl,
 541               /*isInstance=*/false, /*isVariadic=*/false,
 542               /*isPropertyAccessor=*/false,
 543               /*isImplicitlyDeclared=*/true,
 544               /*isDefined=*/false, ObjCMethodDecl::Required,
 545               /*HasRelatedResultType=*/false);
 546           QualType ConstCharType = Context.CharTy.withConst();
 547           ParmVarDecl *value =
 548             ParmVarDecl::Create(Context, M,
 549                                 SourceLocation(), SourceLocation(),
 550                                 &Context.Idents.get("value"),
 551                                 Context.getPointerType(ConstCharType),
 552                                 /*TInfo=*/nullptr,
 553                                 SC_None, nullptr);
 554           M->setMethodParams(Context, value, None);
 555           BoxingMethod = M;
 556         }
 557
 558         if (!validateBoxingMethod(*this, Loc, NSStringDecl,
 559                                   stringWithUTF8String, BoxingMethod))
 560            return ExprError();
 561
 562         StringWithUTF8StringMethod = BoxingMethod;
 563       }
 564
 565       BoxingMethod = StringWithUTF8StringMethod;
 566       BoxedType = NSStringPointer;
 567     }
 568   } else if (ValueType->isBuiltinType()) {
 569     // The other types we support are numeric, char and BOOL/bool. We could also
 570     // provide limited support for structure types, such as NSRange, NSRect, and
 571     // NSSize. See NSValue (NSValueGeometryExtensions) in <Foundation/NSGeometry.h>
 572     // for more details.
 573
 574     // Check for a top-level character literal.
 575     if (const CharacterLiteral *Char =
 576         dyn_cast<CharacterLiteral>(ValueExpr->IgnoreParens())) {
 577       // In C, character literals have type 'int'. That's not the type we want
 578       // to use to determine the Objective-c literal kind.
 579       switch (Char->getKind()) {
 580       case CharacterLiteral::Ascii:
 581       case CharacterLiteral::UTF8:
 582         ValueType = Context.CharTy;
 583         break;
 584
 585       case CharacterLiteral::Wide:
 586         ValueType = Context.getWideCharType();
 587         break;
 588
 589       case CharacterLiteral::UTF16:
 590         ValueType = Context.Char16Ty;
 591         break;
 592
 593       case CharacterLiteral::UTF32:
 594         ValueType = Context.Char32Ty;
 595         break;
 596       }
 597     }
 598     CheckForIntOverflow(ValueExpr);
 599     // FIXME:  Do I need to do anything special with BoolTy expressions?
 600
 601     // Look for the appropriate method within NSNumber.
 602     BoxingMethod = getNSNumberFactoryMethod(*this, Loc, ValueType);
 603     BoxedType = NSNumberPointer;
 604   } else if (const EnumType *ET = ValueType->getAs<EnumType>()) {
 605     if (!ET->getDecl()->isComplete()) {
 606       Diag(Loc, diag::err_objc_incomplete_boxed_expression_type)
 607         << ValueType << ValueExpr->getSourceRange();
 608       return ExprError();
 609     }
 610
 611     BoxingMethod = getNSNumberFactoryMethod(*this, Loc,
 612                                             ET->getDecl()->getIntegerType());
 613     BoxedType = NSNumberPointer;
 614   } else if (ValueType->isObjCBoxableRecordType()) {
 615     // Support for structure types, that marked as objc_boxable
 616     // struct __attribute__((objc_boxable)) s { ... };
 617
 618     // Look up the NSValue class, if we haven't done so already. It's cached
 619     // in the Sema instance.
 620     if (!NSValueDecl) {
 621       NSValueDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
 622                                                       Sema::LK_Boxed);
 623       if (!NSValueDecl) {
 624         return ExprError();
 625       }
 626
 627       // generate the pointer to NSValue type.
 628       QualType NSValueObject = Context.getObjCInterfaceType(NSValueDecl);
 629       NSValuePointer = Context.getObjCObjectPointerType(NSValueObject);
 630     }
 631
 632     if (!ValueWithBytesObjCTypeMethod) {
 633       IdentifierInfo *II[] = {
 634         &Context.Idents.get("valueWithBytes"),
 635         &Context.Idents.get("objCType")
 636       };
 637       Selector ValueWithBytesObjCType = Context.Selectors.getSelector(2, II);
 638
 639       // Look for the appropriate method within NSValue.
 640       BoxingMethod = NSValueDecl->lookupClassMethod(ValueWithBytesObjCType);
 641       if (!BoxingMethod && getLangOpts().DebuggerObjCLiteral) {
 642         // Debugger needs to work even if NSValue hasn't been defined.
 643         TypeSourceInfo *ReturnTInfo = nullptr;
 644         ObjCMethodDecl *M = ObjCMethodDecl::Create(
 645                                                Context,
 646                                                SourceLocation(),
 647                                                SourceLocation(),
 648                                                ValueWithBytesObjCType,
 649                                                NSValuePointer,
 650                                                ReturnTInfo,
 651                                                NSValueDecl,
 652                                                /*isInstance=*/false,
 653                                                /*isVariadic=*/false,
 654                                                /*isPropertyAccessor=*/false,
 655                                                /*isImplicitlyDeclared=*/true,
 656                                                /*isDefined=*/false,
 657                                                ObjCMethodDecl::Required,
 658                                                /*HasRelatedResultType=*/false);
 659
 660         SmallVector<ParmVarDecl *, 2> Params;
 661
 662         ParmVarDecl *bytes =
 663         ParmVarDecl::Create(Context, M,
 664                             SourceLocation(), SourceLocation(),
 665                             &Context.Idents.get("bytes"),
 666                             Context.VoidPtrTy.withConst(),
 667                             /*TInfo=*/nullptr,
 668                             SC_None, nullptr);
 669         Params.push_back(bytes);
 670
 671         QualType ConstCharType = Context.CharTy.withConst();
 672         ParmVarDecl *type =
 673         ParmVarDecl::Create(Context, M,
 674                             SourceLocation(), SourceLocation(),
 675                             &Context.Idents.get("type"),
 676                             Context.getPointerType(ConstCharType),
 677                             /*TInfo=*/nullptr,
 678                             SC_None, nullptr);
 679         Params.push_back(type);
 680
 681         M->setMethodParams(Context, Params, None);
 682         BoxingMethod = M;
 683       }
 684
 685       if (!validateBoxingMethod(*this, Loc, NSValueDecl,
 686                                 ValueWithBytesObjCType, BoxingMethod))
 687         return ExprError();
 688
 689       ValueWithBytesObjCTypeMethod = BoxingMethod;
 690     }
 691
 692     if (!ValueType.isTriviallyCopyableType(Context)) {
 693       Diag(Loc, diag::err_objc_non_trivially_copyable_boxed_expression_type)
 694         << ValueType << ValueExpr->getSourceRange();
 695       return ExprError();
 696     }
 697
 698     BoxingMethod = ValueWithBytesObjCTypeMethod;
 699     BoxedType = NSValuePointer;
 700   }
 701
 702   if (!BoxingMethod) {
 703     Diag(Loc, diag::err_objc_illegal_boxed_expression_type)
 704       << ValueType << ValueExpr->getSourceRange();
 705     return ExprError();
 706   }
 707
 708   DiagnoseUseOfDecl(BoxingMethod, Loc);
 709
 710   ExprResult ConvertedValueExpr;
 711   if (ValueType->isObjCBoxableRecordType()) {
 712     InitializedEntity IE = InitializedEntity::InitializeTemporary(ValueType);
 713     ConvertedValueExpr = PerformCopyInitialization(IE, ValueExpr->getExprLoc(),
 714                                                    ValueExpr);
 715   } else {
 716     // Convert the expression to the type that the parameter requires.
 717     ParmVarDecl *ParamDecl = BoxingMethod->parameters()[0];
 718     InitializedEntity IE = InitializedEntity::InitializeParameter(Context,
 719                                                                   ParamDecl);
 720     ConvertedValueExpr = PerformCopyInitialization(IE, SourceLocation(),
 721                                                    ValueExpr);
 722   }
 723
 724   if (ConvertedValueExpr.isInvalid())
 725     return ExprError();
 726   ValueExpr = ConvertedValueExpr.get();
 727
 728   ObjCBoxedExpr *BoxedExpr =
 729     new (Context) ObjCBoxedExpr(ValueExpr, BoxedType,
 730                                       BoxingMethod, SR);
 731   return MaybeBindToTemporary(BoxedExpr);
 732 }
 733
 734 /// Build an ObjC subscript pseudo-object expression, given that
 735 /// that's supported by the runtime.
 736 ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
 737                                         Expr *IndexExpr,
 738                                         ObjCMethodDecl *getterMethod,
 739                                         ObjCMethodDecl *setterMethod) {
 740   assert(!LangOpts.isSubscriptPointerArithmetic());
 741
 742   // We can't get dependent types here; our callers should have
 743   // filtered them out.
 744   assert((!BaseExpr->isTypeDependent() && !IndexExpr->isTypeDependent()) &&
 745          "base or index cannot have dependent type here");
 746
 747   // Filter out placeholders in the index.  In theory, overloads could
 748   // be preserved here, although that might not actually work correctly.
 749   ExprResult Result = CheckPlaceholderExpr(IndexExpr);
 750   if (Result.isInvalid())
 751     return ExprError();
 752   IndexExpr = Result.get();
 753
 754   // Perform lvalue-to-rvalue conversion on the base.
 755   Result = DefaultLvalueConversion(BaseExpr);
 756   if (Result.isInvalid())
 757     return ExprError();
 758   BaseExpr = Result.get();
 759
 760   // Build the pseudo-object expression.
 761   return new (Context) ObjCSubscriptRefExpr(
 762       BaseExpr, IndexExpr, Context.PseudoObjectTy, VK_LValue, OK_ObjCSubscript,
 763       getterMethod, setterMethod, RB);
 764 }
 765
 766 ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
 767   SourceLocation Loc = SR.getBegin();
 768
 769   if (!NSArrayDecl) {
 770     NSArrayDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
 771                                                     Sema::LK_Array);
 772     if (!NSArrayDecl) {
 773       return ExprError();
 774     }
 775   }
 776
 777   // Find the arrayWithObjects:count: method, if we haven't done so already.
 778   QualType IdT = Context.getObjCIdType();
 779   if (!ArrayWithObjectsMethod) {
 780     Selector
 781       Sel = NSAPIObj->getNSArraySelector(NSAPI::NSArr_arrayWithObjectsCount);
 782     ObjCMethodDecl *Method = NSArrayDecl->lookupClassMethod(Sel);
 783     if (!Method && getLangOpts().DebuggerObjCLiteral) {
 784       TypeSourceInfo *ReturnTInfo = nullptr;
 785       Method = ObjCMethodDecl::Create(
 786           Context, SourceLocation(), SourceLocation(), Sel, IdT, ReturnTInfo,
 787           Context.getTranslationUnitDecl(), false /*Instance*/,
 788           false /*isVariadic*/,
 789           /*isPropertyAccessor=*/false,
 790           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
 791           ObjCMethodDecl::Required, false);
 792       SmallVector<ParmVarDecl *, 2> Params;
 793       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
 794                                                  SourceLocation(),
 795                                                  SourceLocation(),
 796                                                  &Context.Idents.get("objects"),
 797                                                  Context.getPointerType(IdT),
 798                                                  /*TInfo=*/nullptr,
 799                                                  SC_None, nullptr);
 800       Params.push_back(objects);
 801       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
 802                                              SourceLocation(),
 803                                              SourceLocation(),
 804                                              &Context.Idents.get("cnt"),
 805                                              Context.UnsignedLongTy,
 806                                              /*TInfo=*/nullptr, SC_None,
 807                                              nullptr);
 808       Params.push_back(cnt);
 809       Method->setMethodParams(Context, Params, None);
 810     }
 811
 812     if (!validateBoxingMethod(*this, Loc, NSArrayDecl, Sel, Method))
 813       return ExprError();
 814
 815     // Dig out the type that all elements should be converted to.
 816     QualType T = Method->parameters()[0]->getType();
 817     const PointerType *PtrT = T->getAs<PointerType>();
 818     if (!PtrT ||
 819         !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
 820       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
 821         << Sel;
 822       Diag(Method->parameters()[0]->getLocation(),
 823            diag::note_objc_literal_method_param)
 824         << 0 << T
 825         << Context.getPointerType(IdT.withConst());
 826       return ExprError();
 827     }
 828
 829     // Check that the 'count' parameter is integral.
 830     if (!Method->parameters()[1]->getType()->isIntegerType()) {
 831       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
 832         << Sel;
 833       Diag(Method->parameters()[1]->getLocation(),
 834            diag::note_objc_literal_method_param)
 835         << 1
 836         << Method->parameters()[1]->getType()
 837         << "integral";
 838       return ExprError();
 839     }
 840
 841     // We've found a good +arrayWithObjects:count: method. Save it!
 842     ArrayWithObjectsMethod = Method;
 843   }
 844
 845   QualType ObjectsType = ArrayWithObjectsMethod->parameters()[0]->getType();
 846   QualType RequiredType = ObjectsType->castAs<PointerType>()->getPointeeType();
 847
 848   // Check that each of the elements provided is valid in a collection literal,
 849   // performing conversions as necessary.
 850   Expr **ElementsBuffer = Elements.data();
 851   for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
 852     ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
 853                                                              ElementsBuffer[I],
 854                                                              RequiredType, true);
 855     if (Converted.isInvalid())
 856       return ExprError();
 857
 858     ElementsBuffer[I] = Converted.get();
 859   }
 860
 861   QualType Ty
 862     = Context.getObjCObjectPointerType(
 863                                     Context.getObjCInterfaceType(NSArrayDecl));
 864
 865   return MaybeBindToTemporary(
 866            ObjCArrayLiteral::Create(Context, Elements, Ty,
 867                                     ArrayWithObjectsMethod, SR));
 868 }
 869
 870 ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR,
 871                               MutableArrayRef<ObjCDictionaryElement> Elements) {
 872   SourceLocation Loc = SR.getBegin();
 873
 874   if (!NSDictionaryDecl) {
 875     NSDictionaryDecl = LookupObjCInterfaceDeclForLiteral(*this, Loc,
 876                                                          Sema::LK_Dictionary);
 877     if (!NSDictionaryDecl) {
 878       return ExprError();
 879     }
 880   }
 881
 882   // Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
 883   // so already.
 884   QualType IdT = Context.getObjCIdType();
 885   if (!DictionaryWithObjectsMethod) {
 886     Selector Sel = NSAPIObj->getNSDictionarySelector(
 887                                NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
 888     ObjCMethodDecl *Method = NSDictionaryDecl->lookupClassMethod(Sel);
 889     if (!Method && getLangOpts().DebuggerObjCLiteral) {
 890       Method = ObjCMethodDecl::Create(Context,
 891                            SourceLocation(), SourceLocation(), Sel,
 892                            IdT,
 893                            nullptr /*TypeSourceInfo */,
 894                            Context.getTranslationUnitDecl(),
 895                            false /*Instance*/, false/*isVariadic*/,
 896                            /*isPropertyAccessor=*/false,
 897                            /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
 898                            ObjCMethodDecl::Required,
 899                            false);
 900       SmallVector<ParmVarDecl *, 3> Params;
 901       ParmVarDecl *objects = ParmVarDecl::Create(Context, Method,
 902                                                  SourceLocation(),
 903                                                  SourceLocation(),
 904                                                  &Context.Idents.get("objects"),
 905                                                  Context.getPointerType(IdT),
 906                                                  /*TInfo=*/nullptr, SC_None,
 907                                                  nullptr);
 908       Params.push_back(objects);
 909       ParmVarDecl *keys = ParmVarDecl::Create(Context, Method,
 910                                               SourceLocation(),
 911                                               SourceLocation(),
 912                                               &Context.Idents.get("keys"),
 913                                               Context.getPointerType(IdT),
 914                                               /*TInfo=*/nullptr, SC_None,
 915                                               nullptr);
 916       Params.push_back(keys);
 917       ParmVarDecl *cnt = ParmVarDecl::Create(Context, Method,
 918                                              SourceLocation(),
 919                                              SourceLocation(),
 920                                              &Context.Idents.get("cnt"),
 921                                              Context.UnsignedLongTy,
 922                                              /*TInfo=*/nullptr, SC_None,
 923                                              nullptr);
 924       Params.push_back(cnt);
 925       Method->setMethodParams(Context, Params, None);
 926     }
 927
 928     if (!validateBoxingMethod(*this, SR.getBegin(), NSDictionaryDecl, Sel,
 929                               Method))
 930        return ExprError();
 931
 932     // Dig out the type that all values should be converted to.
 933     QualType ValueT = Method->parameters()[0]->getType();
 934     const PointerType *PtrValue = ValueT->getAs<PointerType>();
 935     if (!PtrValue ||
 936         !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
 937       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
 938         << Sel;
 939       Diag(Method->parameters()[0]->getLocation(),
 940            diag::note_objc_literal_method_param)
 941         << 0 << ValueT
 942         << Context.getPointerType(IdT.withConst());
 943       return ExprError();
 944     }
 945
 946     // Dig out the type that all keys should be converted to.
 947     QualType KeyT = Method->parameters()[1]->getType();
 948     const PointerType *PtrKey = KeyT->getAs<PointerType>();
 949     if (!PtrKey ||
 950         !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
 951                                         IdT)) {
 952       bool err = true;
 953       if (PtrKey) {
 954         if (QIDNSCopying.isNull()) {
 955           // key argument of selector is id<NSCopying>?
 956           if (ObjCProtocolDecl *NSCopyingPDecl =
 957               LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
 958             ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
 959             QIDNSCopying =
 960               Context.getObjCObjectType(Context.ObjCBuiltinIdTy, { },
 961                                         llvm::makeArrayRef(
 962                                           (ObjCProtocolDecl**) PQ,
 963                                           1),
 964                                         false);
 965             QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
 966           }
 967         }
 968         if (!QIDNSCopying.isNull())
 969           err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
 970                                                 QIDNSCopying);
 971       }
 972
 973       if (err) {
 974         Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
 975           << Sel;
 976         Diag(Method->parameters()[1]->getLocation(),
 977              diag::note_objc_literal_method_param)
 978           << 1 << KeyT
 979           << Context.getPointerType(IdT.withConst());
 980         return ExprError();
 981       }
 982     }
 983
 984     // Check that the 'count' parameter is integral.
 985     QualType CountType = Method->parameters()[2]->getType();
 986     if (!CountType->isIntegerType()) {
 987       Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
 988         << Sel;
 989       Diag(Method->parameters()[2]->getLocation(),
 990            diag::note_objc_literal_method_param)
 991         << 2 << CountType
 992         << "integral";
 993       return ExprError();
 994     }
 995
 996     // We've found a good +dictionaryWithObjects:keys:count: method; save it!
 997     DictionaryWithObjectsMethod = Method;
 998   }
 999
1000   QualType ValuesT = DictionaryWithObjectsMethod->parameters()[0]->getType();
1001   QualType ValueT = ValuesT->castAs<PointerType>()->getPointeeType();
1002   QualType KeysT = DictionaryWithObjectsMethod->parameters()[1]->getType();
1003   QualType KeyT = KeysT->castAs<PointerType>()->getPointeeType();
1004
1005   // Check that each of the keys and values provided is valid in a collection
1006   // literal, performing conversions as necessary.
1007   bool HasPackExpansions = false;
1008   for (ObjCDictionaryElement &Element : Elements) {
1009     // Check the key.
1010     ExprResult Key = CheckObjCCollectionLiteralElement(*this, Element.Key,
1011                                                        KeyT);
1012     if (Key.isInvalid())
1013       return ExprError();
1014
1015     // Check the value.
1016     ExprResult Value
1017       = CheckObjCCollectionLiteralElement(*this, Element.Value, ValueT);
1018     if (Value.isInvalid())
1019       return ExprError();
1020
1021     Element.Key = Key.get();
1022     Element.Value = Value.get();
1023
1024     if (Element.EllipsisLoc.isInvalid())
1025       continue;
1026
1027     if (!Element.Key->containsUnexpandedParameterPack() &&
1028         !Element.Value->containsUnexpandedParameterPack()) {
1029       Diag(Element.EllipsisLoc,
1030            diag::err_pack_expansion_without_parameter_packs)
1031         << SourceRange(Element.Key->getLocStart(),
1032                        Element.Value->getLocEnd());
1033       return ExprError();
1034     }
1035
1036     HasPackExpansions = true;
1037   }
1038
1039
1040   QualType Ty
1041     = Context.getObjCObjectPointerType(
1042                                 Context.getObjCInterfaceType(NSDictionaryDecl));
1043   return MaybeBindToTemporary(ObjCDictionaryLiteral::Create(
1044       Context, Elements, HasPackExpansions, Ty,
1045       DictionaryWithObjectsMethod, SR));
1046 }
1047
1048 ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
1049                                       TypeSourceInfo *EncodedTypeInfo,
1050                                       SourceLocation RParenLoc) {
1051   QualType EncodedType = EncodedTypeInfo->getType();
1052   QualType StrTy;
1053   if (EncodedType->isDependentType())
1054     StrTy = Context.DependentTy;
1055   else {
1056     if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
1057         !EncodedType->isVoidType()) // void is handled too.
1058       if (RequireCompleteType(AtLoc, EncodedType,
1059                               diag::err_incomplete_type_objc_at_encode,
1060                               EncodedTypeInfo->getTypeLoc()))
1061         return ExprError();
1062
1063     std::string Str;
1064     QualType NotEncodedT;
1065     Context.getObjCEncodingForType(EncodedType, Str, nullptr, &NotEncodedT);
1066     if (!NotEncodedT.isNull())
1067       Diag(AtLoc, diag::warn_incomplete_encoded_type)
1068         << EncodedType << NotEncodedT;
1069
1070     // The type of @encode is the same as the type of the corresponding string,
1071     // which is an array type.
1072     StrTy = Context.CharTy;
1073     // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
1074     if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings)
1075       StrTy.addConst();
1076     StrTy = Context.getConstantArrayType(StrTy, llvm::APInt(32, Str.size()+1),
1077                                          ArrayType::Normal, 0);
1078   }
1079
1080   return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
1081 }
1082
1083 ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
1084                                            SourceLocation EncodeLoc,
1085                                            SourceLocation LParenLoc,
1086                                            ParsedType ty,
1087                                            SourceLocation RParenLoc) {
1088   // FIXME: Preserve type source info ?
1089   TypeSourceInfo *TInfo;
1090   QualType EncodedType = GetTypeFromParser(ty, &TInfo);
1091   if (!TInfo)
1092     TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
1093                                              getLocForEndOfToken(LParenLoc));
1094
1095   return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
1096 }
1097
1098 static bool HelperToDiagnoseMismatchedMethodsInGlobalPool(Sema &S,
1099                                                SourceLocation AtLoc,
1100                                                SourceLocation LParenLoc,
1101                                                SourceLocation RParenLoc,
1102                                                ObjCMethodDecl *Method,
1103                                                ObjCMethodList &MethList) {
1104   ObjCMethodList *M = &MethList;
1105   bool Warned = false;
1106   for (M = M->getNext(); M; M=M->getNext()) {
1107     ObjCMethodDecl *MatchingMethodDecl = M->getMethod();
1108     if (MatchingMethodDecl == Method ||
1109         isa<ObjCImplDecl>(MatchingMethodDecl->getDeclContext()) ||
1110         MatchingMethodDecl->getSelector() != Method->getSelector())
1111       continue;
1112     if (!S.MatchTwoMethodDeclarations(Method,
1113                                       MatchingMethodDecl, Sema::MMS_loose)) {
1114       if (!Warned) {
1115         Warned = true;
1116         S.Diag(AtLoc, diag::warning_multiple_selectors)
1117           << Method->getSelector() << FixItHint::CreateInsertion(LParenLoc, "(")
1118           << FixItHint::CreateInsertion(RParenLoc, ")");
1119         S.Diag(Method->getLocation(), diag::note_method_declared_at)
1120           << Method->getDeclName();
1121       }
1122       S.Diag(MatchingMethodDecl->getLocation(), diag::note_method_declared_at)
1123         << MatchingMethodDecl->getDeclName();
1124     }
1125   }
1126   return Warned;
1127 }
1128
1129 static void DiagnoseMismatchedSelectors(Sema &S, SourceLocation AtLoc,
1130                                         ObjCMethodDecl *Method,
1131                                         SourceLocation LParenLoc,
1132                                         SourceLocation RParenLoc,
1133                                         bool WarnMultipleSelectors) {
1134   if (!WarnMultipleSelectors ||
1135       S.Diags.isIgnored(diag::warning_multiple_selectors, SourceLocation()))
1136     return;
1137   bool Warned = false;
1138   for (Sema::GlobalMethodPool::iterator b = S.MethodPool.begin(),
1139        e = S.MethodPool.end(); b != e; b++) {
1140     // first, instance methods
1141     ObjCMethodList &InstMethList = b->second.first;
1142     if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
1143                                                       Method, InstMethList))
1144       Warned = true;
1145
1146     // second, class methods
1147     ObjCMethodList &ClsMethList = b->second.second;
1148     if (HelperToDiagnoseMismatchedMethodsInGlobalPool(S, AtLoc, LParenLoc, RParenLoc,
1149                                                       Method, ClsMethList) || Warned)
1150       return;
1151   }
1152 }
1153
1154 ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
1155                                              SourceLocation AtLoc,
1156                                              SourceLocation SelLoc,
1157                                              SourceLocation LParenLoc,
1158                                              SourceLocation RParenLoc,
1159                                              bool WarnMultipleSelectors) {
1160   ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
1161                              SourceRange(LParenLoc, RParenLoc));
1162   if (!Method)
1163     Method = LookupFactoryMethodInGlobalPool(Sel,
1164                                           SourceRange(LParenLoc, RParenLoc));
1165   if (!Method) {
1166     if (const ObjCMethodDecl *OM = SelectorsForTypoCorrection(Sel)) {
1167       Selector MatchedSel = OM->getSelector();
1168       SourceRange SelectorRange(LParenLoc.getLocWithOffset(1),
1169                                 RParenLoc.getLocWithOffset(-1));
1170       Diag(SelLoc, diag::warn_undeclared_selector_with_typo)
1171         << Sel << MatchedSel
1172         << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
1173
1174     } else
1175         Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
1176   } else
1177     DiagnoseMismatchedSelectors(*this, AtLoc, Method, LParenLoc, RParenLoc,
1178                                 WarnMultipleSelectors);
1179
1180   if (Method &&
1181       Method->getImplementationControl() != ObjCMethodDecl::Optional &&
1182       !getSourceManager().isInSystemHeader(Method->getLocation()))
1183     ReferencedSelectors.insert(std::make_pair(Sel, AtLoc));
1184
1185   // In ARC, forbid the user from using @selector for
1186   // retain/release/autorelease/dealloc/retainCount.
1187   if (getLangOpts().ObjCAutoRefCount) {
1188     switch (Sel.getMethodFamily()) {
1189     case OMF_retain:
1190     case OMF_release:
1191     case OMF_autorelease:
1192     case OMF_retainCount:
1193     case OMF_dealloc:
1194       Diag(AtLoc, diag::err_arc_illegal_selector) <<
1195         Sel << SourceRange(LParenLoc, RParenLoc);
1196       break;
1197
1198     case OMF_None:
1199     case OMF_alloc:
1200     case OMF_copy:
1201     case OMF_finalize:
1202     case OMF_init:
1203     case OMF_mutableCopy:
1204     case OMF_new:
1205     case OMF_self:
1206     case OMF_initialize:
1207     case OMF_performSelector:
1208       break;
1209     }
1210   }
1211   QualType Ty = Context.getObjCSelType();
1212   return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
1213 }
1214
1215 ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
1216                                              SourceLocation AtLoc,
1217                                              SourceLocation ProtoLoc,
1218                                              SourceLocation LParenLoc,
1219                                              SourceLocation ProtoIdLoc,
1220                                              SourceLocation RParenLoc) {
1221   ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoIdLoc);
1222   if (!PDecl) {
1223     Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
1224     return true;
1225   }
1226   if (PDecl->hasDefinition())
1227     PDecl = PDecl->getDefinition();
1228
1229   QualType Ty = Context.getObjCProtoType();
1230   if (Ty.isNull())
1231     return true;
1232   Ty = Context.getObjCObjectPointerType(Ty);
1233   return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, ProtoIdLoc, RParenLoc);
1234 }
1235
1236 /// Try to capture an implicit reference to 'self'.
1237 ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
1238   DeclContext *DC = getFunctionLevelDeclContext();
1239
1240   // If we're not in an ObjC method, error out.  Note that, unlike the
1241   // C++ case, we don't require an instance method --- class methods
1242   // still have a 'self', and we really do still need to capture it!
1243   ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
1244   if (!method)
1245     return nullptr;
1246
1247   tryCaptureVariable(method->getSelfDecl(), Loc);
1248
1249   return method;
1250 }
1251
1252 static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
1253   QualType origType = T;
1254   if (auto nullability = AttributedType::stripOuterNullability(T)) {
1255     if (T == Context.getObjCInstanceType()) {
1256       return Context.getAttributedType(
1257                AttributedType::getNullabilityAttrKind(*nullability),
1258                Context.getObjCIdType(),
1259                Context.getObjCIdType());
1260     }
1261
1262     return origType;
1263   }
1264
1265   if (T == Context.getObjCInstanceType())
1266     return Context.getObjCIdType();
1267
1268   return origType;
1269 }
1270
1271 /// Determine the result type of a message send based on the receiver type,
1272 /// method, and the kind of message send.
1273 ///
1274 /// This is the "base" result type, which will still need to be adjusted
1275 /// to account for nullability.
1276 static QualType getBaseMessageSendResultType(Sema &S,
1277                                              QualType ReceiverType,
1278                                              ObjCMethodDecl *Method,
1279                                              bool isClassMessage,
1280                                              bool isSuperMessage) {
1281   assert(Method && "Must have a method");
1282   if (!Method->hasRelatedResultType())
1283     return Method->getSendResultType(ReceiverType);
1284
1285   ASTContext &Context = S.Context;
1286
1287   // Local function that transfers the nullability of the method's
1288   // result type to the returned result.
1289   auto transferNullability = [&](QualType type) -> QualType {
1290     // If the method's result type has nullability, extract it.
1291     if (auto nullability = Method->getSendResultType(ReceiverType)
1292                              ->getNullability(Context)){
1293       // Strip off any outer nullability sugar from the provided type.
1294       (void)AttributedType::stripOuterNullability(type);
1295
1296       // Form a new attributed type using the method result type's nullability.
1297       return Context.getAttributedType(
1298                AttributedType::getNullabilityAttrKind(*nullability),
1299                type,
1300                type);
1301     }
1302
1303     return type;
1304   };
1305
1306   // If a method has a related return type:
1307   //   - if the method found is an instance method, but the message send
1308   //     was a class message send, T is the declared return type of the method
1309   //     found
1310   if (Method->isInstanceMethod() && isClassMessage)
1311     return stripObjCInstanceType(Context,
1312                                  Method->getSendResultType(ReceiverType));
1313
1314   //   - if the receiver is super, T is a pointer to the class of the
1315   //     enclosing method definition
1316   if (isSuperMessage) {
1317     if (ObjCMethodDecl *CurMethod = S.getCurMethodDecl())
1318       if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface()) {
1319         return transferNullability(
1320                  Context.getObjCObjectPointerType(
1321                    Context.getObjCInterfaceType(Class)));
1322       }
1323   }
1324
1325   //   - if the receiver is the name of a class U, T is a pointer to U
1326   if (ReceiverType->getAsObjCInterfaceType())
1327     return transferNullability(Context.getObjCObjectPointerType(ReceiverType));
1328   //   - if the receiver is of type Class or qualified Class type,
1329   //     T is the declared return type of the method.
1330   if (ReceiverType->isObjCClassType() ||
1331       ReceiverType->isObjCQualifiedClassType())
1332     return stripObjCInstanceType(Context,
1333                                  Method->getSendResultType(ReceiverType));
1334
1335   //   - if the receiver is id, qualified id, Class, or qualified Class, T
1336   //     is the receiver type, otherwise
1337   //   - T is the type of the receiver expression.
1338   return transferNullability(ReceiverType);
1339 }
1340
1341 QualType Sema::getMessageSendResultType(QualType ReceiverType,
1342                                         ObjCMethodDecl *Method,
1343                                         bool isClassMessage,
1344                                         bool isSuperMessage) {
1345   // Produce the result type.
1346   QualType resultType = getBaseMessageSendResultType(*this, ReceiverType,
1347                                                      Method,
1348                                                      isClassMessage,
1349                                                      isSuperMessage);
1350
1351   // If this is a class message, ignore the nullability of the receiver.
1352   if (isClassMessage)
1353     return resultType;
1354
1355   // Map the nullability of the result into a table index.
1356   unsigned receiverNullabilityIdx = 0;
1357   if (auto nullability = ReceiverType->getNullability(Context))
1358     receiverNullabilityIdx = 1 + static_cast<unsigned>(*nullability);
1359
1360   unsigned resultNullabilityIdx = 0;
1361   if (auto nullability = resultType->getNullability(Context))
1362     resultNullabilityIdx = 1 + static_cast<unsigned>(*nullability);
1363
1364   // The table of nullability mappings, indexed by the receiver's nullability
1365   // and then the result type's nullability.
1366   static const uint8_t None = 0;
1367   static const uint8_t NonNull = 1;
1368   static const uint8_t Nullable = 2;
1369   static const uint8_t Unspecified = 3;
1370   static const uint8_t nullabilityMap[4][4] = {
1371     //                  None        NonNull       Nullable    Unspecified
1372     /* None */        { None,       None,         Nullable,   None },
1373     /* NonNull */     { None,       NonNull,      Nullable,   Unspecified },
1374     /* Nullable */    { Nullable,   Nullable,     Nullable,   Nullable },
1375     /* Unspecified */ { None,       Unspecified,  Nullable,   Unspecified }
1376   };
1377
1378   unsigned newResultNullabilityIdx
1379     = nullabilityMap[receiverNullabilityIdx][resultNullabilityIdx];
1380   if (newResultNullabilityIdx == resultNullabilityIdx)
1381     return resultType;
1382
1383   // Strip off the existing nullability. This removes as little type sugar as
1384   // possible.
1385   do {
1386     if (auto attributed = dyn_cast<AttributedType>(resultType.getTypePtr())) {
1387       resultType = attributed->getModifiedType();
1388     } else {
1389       resultType = resultType.getDesugaredType(Context);
1390     }
1391   } while (resultType->getNullability(Context));
1392
1393   // Add nullability back if needed.
1394   if (newResultNullabilityIdx > 0) {
1395     auto newNullability
1396       = static_cast<NullabilityKind>(newResultNullabilityIdx-1);
1397     return Context.getAttributedType(
1398              AttributedType::getNullabilityAttrKind(newNullability),
1399              resultType, resultType);
1400   }
1401
1402   return resultType;
1403 }
1404
1405 /// Look for an ObjC method whose result type exactly matches the given type.
1406 static const ObjCMethodDecl *
1407 findExplicitInstancetypeDeclarer(const ObjCMethodDecl *MD,
1408                                  QualType instancetype) {
1409   if (MD->getReturnType() == instancetype)
1410     return MD;
1411
1412   // For these purposes, a method in an @implementation overrides a
1413   // declaration in the @interface.
1414   if (const ObjCImplDecl *impl =
1415         dyn_cast<ObjCImplDecl>(MD->getDeclContext())) {
1416     const ObjCContainerDecl *iface;
1417     if (const ObjCCategoryImplDecl *catImpl =
1418           dyn_cast<ObjCCategoryImplDecl>(impl)) {
1419       iface = catImpl->getCategoryDecl();
1420     } else {
1421       iface = impl->getClassInterface();
1422     }
1423
1424     const ObjCMethodDecl *ifaceMD =
1425       iface->getMethod(MD->getSelector(), MD->isInstanceMethod());
1426     if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype);
1427   }
1428
1429   SmallVector<const ObjCMethodDecl *, 4> overrides;
1430   MD->getOverriddenMethods(overrides);
1431   for (unsigned i = 0, e = overrides.size(); i != e; ++i) {
1432     if (const ObjCMethodDecl *result =
1433           findExplicitInstancetypeDeclarer(overrides[i], instancetype))
1434       return result;
1435   }
1436
1437   return nullptr;
1438 }
1439
1440 void Sema::EmitRelatedResultTypeNoteForReturn(QualType destType) {
1441   // Only complain if we're in an ObjC method and the required return
1442   // type doesn't match the method's declared return type.
1443   ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurContext);
1444   if (!MD || !MD->hasRelatedResultType() ||
1445       Context.hasSameUnqualifiedType(destType, MD->getReturnType()))
1446     return;
1447
1448   // Look for a method overridden by this method which explicitly uses
1449   // 'instancetype'.
1450   if (const ObjCMethodDecl *overridden =
1451         findExplicitInstancetypeDeclarer(MD, Context.getObjCInstanceType())) {
1452     SourceRange range = overridden->getReturnTypeSourceRange();
1453     SourceLocation loc = range.getBegin();
1454     if (loc.isInvalid())
1455       loc = overridden->getLocation();
1456     Diag(loc, diag::note_related_result_type_explicit)
1457       << /*current method*/ 1 << range;
1458     return;
1459   }
1460
1461   // Otherwise, if we have an interesting method family, note that.
1462   // This should always trigger if the above didn't.
1463   if (ObjCMethodFamily family = MD->getMethodFamily())
1464     Diag(MD->getLocation(), diag::note_related_result_type_family)
1465       << /*current method*/ 1
1466       << family;
1467 }
1468
1469 void Sema::EmitRelatedResultTypeNote(const Expr *E) {
1470   E = E->IgnoreParenImpCasts();
1471   const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
1472   if (!MsgSend)
1473     return;
1474
1475   const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
1476   if (!Method)
1477     return;
1478
1479   if (!Method->hasRelatedResultType())
1480     return;
1481
1482   if (Context.hasSameUnqualifiedType(
1483           Method->getReturnType().getNonReferenceType(), MsgSend->getType()))
1484     return;
1485
1486   if (!Context.hasSameUnqualifiedType(Method->getReturnType(),
1487                                       Context.getObjCInstanceType()))
1488     return;
1489
1490   Diag(Method->getLocation(), diag::note_related_result_type_inferred)
1491     << Method->isInstanceMethod() << Method->getSelector()
1492     << MsgSend->getType();
1493 }
1494
1495 bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
1496                                      MultiExprArg Args,
1497                                      Selector Sel,
1498                                      ArrayRef<SourceLocation> SelectorLocs,
1499                                      ObjCMethodDecl *Method,
1500                                      bool isClassMessage, bool isSuperMessage,
1501                                      SourceLocation lbrac, SourceLocation rbrac,
1502                                      SourceRange RecRange,
1503                                      QualType &ReturnType, ExprValueKind &VK) {
1504   SourceLocation SelLoc;
1505   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
1506     SelLoc = SelectorLocs.front();
1507   else
1508     SelLoc = lbrac;
1509
1510   if (!Method) {
1511     // Apply default argument promotion as for (C99 6.5.2.2p6).
1512     for (unsigned i = 0, e = Args.size(); i != e; i++) {
1513       if (Args[i]->isTypeDependent())
1514         continue;
1515
1516       ExprResult result;
1517       if (getLangOpts().DebuggerSupport) {
1518         QualType paramTy; // ignored
1519         result = checkUnknownAnyArg(SelLoc, Args[i], paramTy);
1520       } else {
1521         result = DefaultArgumentPromotion(Args[i]);
1522       }
1523       if (result.isInvalid())
1524         return true;
1525       Args[i] = result.get();
1526     }
1527
1528     unsigned DiagID;
1529     if (getLangOpts().ObjCAutoRefCount)
1530       DiagID = diag::err_arc_method_not_found;
1531     else
1532       DiagID = isClassMessage ? diag::warn_class_method_not_found
1533                               : diag::warn_inst_method_not_found;
1534     if (!getLangOpts().DebuggerSupport) {
1535       const ObjCMethodDecl *OMD = SelectorsForTypoCorrection(Sel, ReceiverType);
1536       if (OMD && !OMD->isInvalidDecl()) {
1537         if (getLangOpts().ObjCAutoRefCount)
1538           DiagID = diag::error_method_not_found_with_typo;
1539         else
1540           DiagID = isClassMessage ? diag::warn_class_method_not_found_with_typo
1541                                   : diag::warn_instance_method_not_found_with_typo;
1542         Selector MatchedSel = OMD->getSelector();
1543         SourceRange SelectorRange(SelectorLocs.front(), SelectorLocs.back());
1544         if (MatchedSel.isUnarySelector())
1545           Diag(SelLoc, DiagID)
1546             << Sel<< isClassMessage << MatchedSel
1547             << FixItHint::CreateReplacement(SelectorRange, MatchedSel.getAsString());
1548         else
1549           Diag(SelLoc, DiagID) << Sel<< isClassMessage << MatchedSel;
1550       }
1551       else
1552         Diag(SelLoc, DiagID)
1553           << Sel << isClassMessage << SourceRange(SelectorLocs.front(),
1554                                                 SelectorLocs.back());
1555       // Find the class to which we are sending this message.
1556       if (ReceiverType->isObjCObjectPointerType()) {
1557         if (ObjCInterfaceDecl *ThisClass =
1558             ReceiverType->getAs<ObjCObjectPointerType>()->getInterfaceDecl()) {
1559           Diag(ThisClass->getLocation(), diag::note_receiver_class_declared);
1560           if (!RecRange.isInvalid())
1561             if (ThisClass->lookupClassMethod(Sel))
1562               Diag(RecRange.getBegin(),diag::note_receiver_expr_here)
1563                 << FixItHint::CreateReplacement(RecRange,
1564                                                 ThisClass->getNameAsString());
1565         }
1566       }
1567     }
1568
1569     // In debuggers, we want to use __unknown_anytype for these
1570     // results so that clients can cast them.
1571     if (getLangOpts().DebuggerSupport) {
1572       ReturnType = Context.UnknownAnyTy;
1573     } else {
1574       ReturnType = Context.getObjCIdType();
1575     }
1576     VK = VK_RValue;
1577     return false;
1578   }
1579
1580   ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage,
1581                                         isSuperMessage);
1582   VK = Expr::getValueKindForType(Method->getReturnType());
1583
1584   unsigned NumNamedArgs = Sel.getNumArgs();
1585   // Method might have more arguments than selector indicates. This is due
1586   // to addition of c-style arguments in method.
1587   if (Method->param_size() > Sel.getNumArgs())
1588     NumNamedArgs = Method->param_size();
1589   // FIXME. This need be cleaned up.
1590   if (Args.size() < NumNamedArgs) {
1591     Diag(SelLoc, diag::err_typecheck_call_too_few_args)
1592       << 2 << NumNamedArgs << static_cast<unsigned>(Args.size());
1593     return false;
1594   }
1595
1596   // Compute the set of type arguments to be substituted into each parameter
1597   // type.
1598   Optional<ArrayRef<QualType>> typeArgs
1599     = ReceiverType->getObjCSubstitutions(Method->getDeclContext());
1600   bool IsError = false;
1601   for (unsigned i = 0; i < NumNamedArgs; i++) {
1602     // We can't do any type-checking on a type-dependent argument.
1603     if (Args[i]->isTypeDependent())
1604       continue;
1605
1606     Expr *argExpr = Args[i];
1607
1608     ParmVarDecl *param = Method->parameters()[i];
1609     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
1610
1611     // Strip the unbridged-cast placeholder expression off unless it's
1612     // a consumed argument.
1613     if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
1614         !param->hasAttr<CFConsumedAttr>())
1615       argExpr = stripARCUnbridgedCast(argExpr);
1616
1617     // If the parameter is __unknown_anytype, infer its type
1618     // from the argument.
1619     if (param->getType() == Context.UnknownAnyTy) {
1620       QualType paramType;
1621       ExprResult argE = checkUnknownAnyArg(SelLoc, argExpr, paramType);
1622       if (argE.isInvalid()) {
1623         IsError = true;
1624       } else {
1625         Args[i] = argE.get();
1626
1627         // Update the parameter type in-place.
1628         param->setType(paramType);
1629       }
1630       continue;
1631     }
1632
1633     QualType origParamType = param->getType();
1634     QualType paramType = param->getType();
1635     if (typeArgs)
1636       paramType = paramType.substObjCTypeArgs(
1637                     Context,
1638                     *typeArgs,
1639                     ObjCSubstitutionContext::Parameter);
1640
1641     if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
1642                             paramType,
1643                             diag::err_call_incomplete_argument, argExpr))
1644       return true;
1645
1646     InitializedEntity Entity
1647       = InitializedEntity::InitializeParameter(Context, param, paramType);
1648     ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), argExpr);
1649     if (ArgE.isInvalid())
1650       IsError = true;
1651     else {
1652       Args[i] = ArgE.getAs<Expr>();
1653
1654       // If we are type-erasing a block to a block-compatible
1655       // Objective-C pointer type, we may need to extend the lifetime
1656       // of the block object.
1657       if (typeArgs && Args[i]->isRValue() && paramType->isBlockPointerType() &&
1658           Args[i]->getType()->isBlockPointerType() &&
1659           origParamType->isObjCObjectPointerType()) {
1660         ExprResult arg = Args[i];
1661         maybeExtendBlockObject(arg);
1662         Args[i] = arg.get();
1663       }
1664     }
1665   }
1666
1667   // Promote additional arguments to variadic methods.
1668   if (Method->isVariadic()) {
1669     for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
1670       if (Args[i]->isTypeDependent())
1671         continue;
1672
1673       ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
1674                                                         nullptr);
1675       IsError |= Arg.isInvalid();
1676       Args[i] = Arg.get();
1677     }
1678   } else {
1679     // Check for extra arguments to non-variadic methods.
1680     if (Args.size() != NumNamedArgs) {
1681       Diag(Args[NumNamedArgs]->getLocStart(),
1682            diag::err_typecheck_call_too_many_args)
1683         << 2 /*method*/ << NumNamedArgs << static_cast<unsigned>(Args.size())
1684         << Method->getSourceRange()
1685         << SourceRange(Args[NumNamedArgs]->getLocStart(),
1686                        Args.back()->getLocEnd());
1687     }
1688   }
1689
1690   DiagnoseSentinelCalls(Method, SelLoc, Args);
1691
1692   // Do additional checkings on method.
1693   IsError |= CheckObjCMethodCall(
1694       Method, SelLoc, makeArrayRef(Args.data(), Args.size()));
1695
1696   return IsError;
1697 }
1698
1699 bool Sema::isSelfExpr(Expr *RExpr) {
1700   // 'self' is objc 'self' in an objc method only.
1701   ObjCMethodDecl *Method =
1702       dyn_cast_or_null<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
1703   return isSelfExpr(RExpr, Method);
1704 }
1705
1706 bool Sema::isSelfExpr(Expr *receiver, const ObjCMethodDecl *method) {
1707   if (!method) return false;
1708
1709   receiver = receiver->IgnoreParenLValueCasts();
1710   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
1711     if (DRE->getDecl() == method->getSelfDecl())
1712       return true;
1713   return false;
1714 }
1715
1716 /// LookupMethodInType - Look up a method in an ObjCObjectType.
1717 ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
1718                                                bool isInstance) {
1719   const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
1720   if (ObjCInterfaceDecl *iface = objType->getInterface()) {
1721     // Look it up in the main interface (and categories, etc.)
1722     if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
1723       return method;
1724
1725     // Okay, look for "private" methods declared in any
1726     // @implementations we've seen.
1727     if (ObjCMethodDecl *method = iface->lookupPrivateMethod(sel, isInstance))
1728       return method;
1729   }
1730
1731   // Check qualifiers.
1732   for (const auto *I : objType->quals())
1733     if (ObjCMethodDecl *method = I->lookupMethod(sel, isInstance))
1734       return method;
1735
1736   return nullptr;
1737 }
1738
1739 /// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier
1740 /// list of a qualified objective pointer type.
1741 ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
1742                                               const ObjCObjectPointerType *OPT,
1743                                               bool Instance)
1744 {
1745   ObjCMethodDecl *MD = nullptr;
1746   for (const auto *PROTO : OPT->quals()) {
1747     if ((MD = PROTO->lookupMethod(Sel, Instance))) {
1748       return MD;
1749     }
1750   }
1751   return nullptr;
1752 }
1753
1754 /// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
1755 /// objective C interface.  This is a property reference expression.
1756 ExprResult Sema::
1757 HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
1758                           Expr *BaseExpr, SourceLocation OpLoc,
1759                           DeclarationName MemberName,
1760                           SourceLocation MemberLoc,
1761                           SourceLocation SuperLoc, QualType SuperType,
1762                           bool Super) {
1763   const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
1764   ObjCInterfaceDecl *IFace = IFaceT->getDecl();
1765
1766   if (!MemberName.isIdentifier()) {
1767     Diag(MemberLoc, diag::err_invalid_property_name)
1768       << MemberName << QualType(OPT, 0);
1769     return ExprError();
1770   }
1771
1772   IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1773
1774   SourceRange BaseRange = Super? SourceRange(SuperLoc)
1775                                : BaseExpr->getSourceRange();
1776   if (RequireCompleteType(MemberLoc, OPT->getPointeeType(),
1777                           diag::err_property_not_found_forward_class,
1778                           MemberName, BaseRange))
1779     return ExprError();
1780
1781   if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
1782     // Check whether we can reference this property.
1783     if (DiagnoseUseOfDecl(PD, MemberLoc))
1784       return ExprError();
1785     if (Super)
1786       return new (Context)
1787           ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1788                               OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
1789     else
1790       return new (Context)
1791           ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1792                               OK_ObjCProperty, MemberLoc, BaseExpr);
1793   }
1794   // Check protocols on qualified interfaces.
1795   for (const auto *I : OPT->quals())
1796     if (ObjCPropertyDecl *PD = I->FindPropertyDeclaration(Member)) {
1797       // Check whether we can reference this property.
1798       if (DiagnoseUseOfDecl(PD, MemberLoc))
1799         return ExprError();
1800
1801       if (Super)
1802         return new (Context) ObjCPropertyRefExpr(
1803             PD, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty, MemberLoc,
1804             SuperLoc, SuperType);
1805       else
1806         return new (Context)
1807             ObjCPropertyRefExpr(PD, Context.PseudoObjectTy, VK_LValue,
1808                                 OK_ObjCProperty, MemberLoc, BaseExpr);
1809     }
1810   // If that failed, look for an "implicit" property by seeing if the nullary
1811   // selector is implemented.
1812
1813   // FIXME: The logic for looking up nullary and unary selectors should be
1814   // shared with the code in ActOnInstanceMessage.
1815
1816   Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
1817   ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
1818
1819   // May be founf in property's qualified list.
1820   if (!Getter)
1821     Getter = LookupMethodInQualifiedType(Sel, OPT, true);
1822
1823   // If this reference is in an @implementation, check for 'private' methods.
1824   if (!Getter)
1825     Getter = IFace->lookupPrivateMethod(Sel);
1826
1827   if (Getter) {
1828     // Check if we can reference this property.
1829     if (DiagnoseUseOfDecl(Getter, MemberLoc))
1830       return ExprError();
1831   }
1832   // If we found a getter then this may be a valid dot-reference, we
1833   // will look for the matching setter, in case it is needed.
1834   Selector SetterSel =
1835     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1836                                            PP.getSelectorTable(), Member);
1837   ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
1838
1839   // May be founf in property's qualified list.
1840   if (!Setter)
1841     Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
1842
1843   if (!Setter) {
1844     // If this reference is in an @implementation, also check for 'private'
1845     // methods.
1846     Setter = IFace->lookupPrivateMethod(SetterSel);
1847   }
1848
1849   if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
1850     return ExprError();
1851
1852   // Special warning if member name used in a property-dot for a setter accessor
1853   // does not use a property with same name; e.g. obj.X = ... for a property with
1854   // name 'x'.
1855   if (Setter && Setter->isImplicit() && Setter->isPropertyAccessor()
1856       && !IFace->FindPropertyDeclaration(Member)) {
1857       if (const ObjCPropertyDecl *PDecl = Setter->findPropertyDecl()) {
1858         // Do not warn if user is using property-dot syntax to make call to
1859         // user named setter.
1860         if (!(PDecl->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_setter))
1861           Diag(MemberLoc,
1862                diag::warn_property_access_suggest)
1863           << MemberName << QualType(OPT, 0) << PDecl->getName()
1864           << FixItHint::CreateReplacement(MemberLoc, PDecl->getName());
1865       }
1866   }
1867
1868   if (Getter || Setter) {
1869     if (Super)
1870       return new (Context)
1871           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
1872                               OK_ObjCProperty, MemberLoc, SuperLoc, SuperType);
1873     else
1874       return new (Context)
1875           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
1876                               OK_ObjCProperty, MemberLoc, BaseExpr);
1877
1878   }
1879
1880   // Attempt to correct for typos in property names.
1881   if (TypoCorrection Corrected =
1882           CorrectTypo(DeclarationNameInfo(MemberName, MemberLoc),
1883                       LookupOrdinaryName, nullptr, nullptr,
1884                       llvm::make_unique<DeclFilterCCC<ObjCPropertyDecl>>(),
1885                       CTK_ErrorRecovery, IFace, false, OPT)) {
1886     diagnoseTypo(Corrected, PDiag(diag::err_property_not_found_suggest)
1887                               << MemberName << QualType(OPT, 0));
1888     DeclarationName TypoResult = Corrected.getCorrection();
1889     return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
1890                                      TypoResult, MemberLoc,
1891                                      SuperLoc, SuperType, Super);
1892   }
1893   ObjCInterfaceDecl *ClassDeclared;
1894   if (ObjCIvarDecl *Ivar =
1895       IFace->lookupInstanceVariable(Member, ClassDeclared)) {
1896     QualType T = Ivar->getType();
1897     if (const ObjCObjectPointerType * OBJPT =
1898         T->getAsObjCInterfacePointerType()) {
1899       if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(),
1900                               diag::err_property_not_as_forward_class,
1901                               MemberName, BaseExpr))
1902         return ExprError();
1903     }
1904     Diag(MemberLoc,
1905          diag::err_ivar_access_using_property_syntax_suggest)
1906     << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
1907     << FixItHint::CreateReplacement(OpLoc, "->");
1908     return ExprError();
1909   }
1910
1911   Diag(MemberLoc, diag::err_property_not_found)
1912     << MemberName << QualType(OPT, 0);
1913   if (Setter)
1914     Diag(Setter->getLocation(), diag::note_getter_unavailable)
1915           << MemberName << BaseExpr->getSourceRange();
1916   return ExprError();
1917 }
1918
1919
1920
1921 ExprResult Sema::
1922 ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
1923                           IdentifierInfo &propertyName,
1924                           SourceLocation receiverNameLoc,
1925                           SourceLocation propertyNameLoc) {
1926
1927   IdentifierInfo *receiverNamePtr = &receiverName;
1928   ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
1929                                                   receiverNameLoc);
1930
1931   QualType SuperType;
1932   if (!IFace) {
1933     // If the "receiver" is 'super' in a method, handle it as an expression-like
1934     // property reference.
1935     if (receiverNamePtr->isStr("super")) {
1936       if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
1937         if (auto classDecl = CurMethod->getClassInterface()) {
1938           SuperType = QualType(classDecl->getSuperClassType(), 0);
1939           if (CurMethod->isInstanceMethod()) {
1940             if (SuperType.isNull()) {
1941               // The current class does not have a superclass.
1942               Diag(receiverNameLoc, diag::error_root_class_cannot_use_super)
1943                 << CurMethod->getClassInterface()->getIdentifier();
1944               return ExprError();
1945             }
1946             QualType T = Context.getObjCObjectPointerType(SuperType);
1947
1948             return HandleExprPropertyRefExpr(T->castAs<ObjCObjectPointerType>(),
1949                                              /*BaseExpr*/nullptr,
1950                                              SourceLocation()/*OpLoc*/,
1951                                              &propertyName,
1952                                              propertyNameLoc,
1953                                              receiverNameLoc, T, true);
1954           }
1955
1956           // Otherwise, if this is a class method, try dispatching to our
1957           // superclass.
1958           IFace = CurMethod->getClassInterface()->getSuperClass();
1959         }
1960       }
1961     }
1962
1963     if (!IFace) {
1964       Diag(receiverNameLoc, diag::err_expected_either) << tok::identifier
1965                                                        << tok::l_paren;
1966       return ExprError();
1967     }
1968   }
1969
1970   // Search for a declared property first.
1971   Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
1972   ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
1973
1974   // If this reference is in an @implementation, check for 'private' methods.
1975   if (!Getter)
1976     Getter = IFace->lookupPrivateClassMethod(Sel);
1977
1978   if (Getter) {
1979     // FIXME: refactor/share with ActOnMemberReference().
1980     // Check if we can reference this property.
1981     if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
1982       return ExprError();
1983   }
1984
1985   // Look for the matching setter, in case it is needed.
1986   Selector SetterSel =
1987     SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
1988                                             PP.getSelectorTable(),
1989                                            &propertyName);
1990
1991   ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1992   if (!Setter) {
1993     // If this reference is in an @implementation, also check for 'private'
1994     // methods.
1995     Setter = IFace->lookupPrivateClassMethod(SetterSel);
1996   }
1997   // Look through local category implementations associated with the class.
1998   if (!Setter)
1999     Setter = IFace->getCategoryClassMethod(SetterSel);
2000
2001   if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
2002     return ExprError();
2003
2004   if (Getter || Setter) {
2005     if (!SuperType.isNull())
2006       return new (Context)
2007           ObjCPropertyRefExpr(Getter, Setter, Context.PseudoObjectTy, VK_LValue,
2008                               OK_ObjCProperty, propertyNameLoc, receiverNameLoc,
2009                               SuperType);
2010
2011     return new (Context) ObjCPropertyRefExpr(
2012         Getter, Setter, Context.PseudoObjectTy, VK_LValue, OK_ObjCProperty,
2013         propertyNameLoc, receiverNameLoc, IFace);
2014   }
2015   return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
2016                      << &propertyName << Context.getObjCInterfaceType(IFace));
2017 }
2018
2019 namespace {
2020
2021 class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
2022  public:
2023   ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
2024     // Determine whether "super" is acceptable in the current context.
2025     if (Method && Method->getClassInterface())
2026       WantObjCSuper = Method->getClassInterface()->getSuperClass();
2027   }
2028
2029   bool ValidateCandidate(const TypoCorrection &candidate) override {
2030     return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
2031         candidate.isKeyword("super");
2032   }
2033 };
2034
2035 }
2036
2037 Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
2038                                                IdentifierInfo *Name,
2039                                                SourceLocation NameLoc,
2040                                                bool IsSuper,
2041                                                bool HasTrailingDot,
2042                                                ParsedType &ReceiverType) {
2043   ReceiverType = ParsedType();
2044
2045   // If the identifier is "super" and there is no trailing dot, we're
2046   // messaging super. If the identifier is "super" and there is a
2047   // trailing dot, it's an instance message.
2048   if (IsSuper && S->isInObjcMethodScope())
2049     return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
2050
2051   LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
2052   LookupName(Result, S);
2053
2054   switch (Result.getResultKind()) {
2055   case LookupResult::NotFound:
2056     // Normal name lookup didn't find anything. If we're in an
2057     // Objective-C method, look for ivars. If we find one, we're done!
2058     // FIXME: This is a hack. Ivar lookup should be part of normal
2059     // lookup.
2060     if (ObjCMethodDecl *Method = getCurMethodDecl()) {
2061       if (!Method->getClassInterface()) {
2062         // Fall back: let the parser try to parse it as an instance message.
2063         return ObjCInstanceMessage;
2064       }
2065
2066       ObjCInterfaceDecl *ClassDeclared;
2067       if (Method->getClassInterface()->lookupInstanceVariable(Name,
2068                                                               ClassDeclared))
2069         return ObjCInstanceMessage;
2070     }
2071
2072     // Break out; we'll perform typo correction below.
2073     break;
2074
2075   case LookupResult::NotFoundInCurrentInstantiation:
2076   case LookupResult::FoundOverloaded:
2077   case LookupResult::FoundUnresolvedValue:
2078   case LookupResult::Ambiguous:
2079     Result.suppressDiagnostics();
2080     return ObjCInstanceMessage;
2081
2082   case LookupResult::Found: {
2083     // If the identifier is a class or not, and there is a trailing dot,
2084     // it's an instance message.
2085     if (HasTrailingDot)
2086       return ObjCInstanceMessage;
2087     // We found something. If it's a type, then we have a class
2088     // message. Otherwise, it's an instance message.
2089     NamedDecl *ND = Result.getFoundDecl();
2090     QualType T;
2091     if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
2092       T = Context.getObjCInterfaceType(Class);
2093     else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND)) {
2094       T = Context.getTypeDeclType(Type);
2095       DiagnoseUseOfDecl(Type, NameLoc);
2096     }
2097     else
2098       return ObjCInstanceMessage;
2099
2100     //  We have a class message, and T is the type we're
2101     //  messaging. Build source-location information for it.
2102     TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
2103     ReceiverType = CreateParsedType(T, TSInfo);
2104     return ObjCClassMessage;
2105   }
2106   }
2107
2108   if (TypoCorrection Corrected = CorrectTypo(
2109           Result.getLookupNameInfo(), Result.getLookupKind(), S, nullptr,
2110           llvm::make_unique<ObjCInterfaceOrSuperCCC>(getCurMethodDecl()),
2111           CTK_ErrorRecovery, nullptr, false, nullptr, false)) {
2112     if (Corrected.isKeyword()) {
2113       // If we've found the keyword "super" (the only keyword that would be
2114       // returned by CorrectTypo), this is a send to super.
2115       diagnoseTypo(Corrected,
2116                    PDiag(diag::err_unknown_receiver_suggest) << Name);
2117       return ObjCSuperMessage;
2118     } else if (ObjCInterfaceDecl *Class =
2119                    Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
2120       // If we found a declaration, correct when it refers to an Objective-C
2121       // class.
2122       diagnoseTypo(Corrected,
2123                    PDiag(diag::err_unknown_receiver_suggest) << Name);
2124       QualType T = Context.getObjCInterfaceType(Class);
2125       TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
2126       ReceiverType = CreateParsedType(T, TSInfo);
2127       return ObjCClassMessage;
2128     }
2129   }
2130
2131   // Fall back: let the parser try to parse it as an instance message.
2132   return ObjCInstanceMessage;
2133 }
2134
2135 ExprResult Sema::ActOnSuperMessage(Scope *S,
2136                                    SourceLocation SuperLoc,
2137                                    Selector Sel,
2138                                    SourceLocation LBracLoc,
2139                                    ArrayRef<SourceLocation> SelectorLocs,
2140                                    SourceLocation RBracLoc,
2141                                    MultiExprArg Args) {
2142   // Determine whether we are inside a method or not.
2143   ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
2144   if (!Method) {
2145     Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
2146     return ExprError();
2147   }
2148
2149   ObjCInterfaceDecl *Class = Method->getClassInterface();
2150   if (!Class) {
2151     Diag(SuperLoc, diag::error_no_super_class_message)
2152       << Method->getDeclName();
2153     return ExprError();
2154   }
2155
2156   QualType SuperTy(Class->getSuperClassType(), 0);
2157   if (SuperTy.isNull()) {
2158     // The current class does not have a superclass.
2159     Diag(SuperLoc, diag::error_root_class_cannot_use_super)
2160       << Class->getIdentifier();
2161     return ExprError();
2162   }
2163
2164   // We are in a method whose class has a superclass, so 'super'
2165   // is acting as a keyword.
2166   if (Method->getSelector() == Sel)
2167     getCurFunction()->ObjCShouldCallSuper = false;
2168
2169   if (Method->isInstanceMethod()) {
2170     // Since we are in an instance method, this is an instance
2171     // message to the superclass instance.
2172     SuperTy = Context.getObjCObjectPointerType(SuperTy);
2173     return BuildInstanceMessage(nullptr, SuperTy, SuperLoc,
2174                                 Sel, /*Method=*/nullptr,
2175                                 LBracLoc, SelectorLocs, RBracLoc, Args);
2176   }
2177
2178   // Since we are in a class method, this is a class message to
2179   // the superclass.
2180   return BuildClassMessage(/*ReceiverTypeInfo=*/nullptr,
2181                            SuperTy,
2182                            SuperLoc, Sel, /*Method=*/nullptr,
2183                            LBracLoc, SelectorLocs, RBracLoc, Args);
2184 }
2185
2186
2187 ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
2188                                            bool isSuperReceiver,
2189                                            SourceLocation Loc,
2190                                            Selector Sel,
2191                                            ObjCMethodDecl *Method,
2192                                            MultiExprArg Args) {
2193   TypeSourceInfo *receiverTypeInfo = nullptr;
2194   if (!ReceiverType.isNull())
2195     receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
2196
2197   return BuildClassMessage(receiverTypeInfo, ReceiverType,
2198                           /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
2199                            Sel, Method, Loc, Loc, Loc, Args,
2200                            /*isImplicit=*/true);
2201
2202 }
2203
2204 static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
2205                                unsigned DiagID,
2206                                bool (*refactor)(const ObjCMessageExpr *,
2207                                               const NSAPI &, edit::Commit &)) {
2208   SourceLocation MsgLoc = Msg->getExprLoc();
2209   if (S.Diags.isIgnored(DiagID, MsgLoc))
2210     return;
2211
2212   SourceManager &SM = S.SourceMgr;
2213   edit::Commit ECommit(SM, S.LangOpts);
2214   if (refactor(Msg,*S.NSAPIObj, ECommit)) {
2215     DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
2216                         << Msg->getSelector() << Msg->getSourceRange();
2217     // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
2218     if (!ECommit.isCommitable())
2219       return;
2220     for (edit::Commit::edit_iterator
2221            I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
2222       const edit::Commit::Edit &Edit = *I;
2223       switch (Edit.Kind) {
2224       case edit::Commit::Act_Insert:
2225         Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
2226                                                         Edit.Text,
2227                                                         Edit.BeforePrev));
2228         break;
2229       case edit::Commit::Act_InsertFromRange:
2230         Builder.AddFixItHint(
2231             FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
2232                                                 Edit.getInsertFromRange(SM),
2233                                                 Edit.BeforePrev));
2234         break;
2235       case edit::Commit::Act_Remove:
2236         Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
2237         break;
2238       }
2239     }
2240   }
2241 }
2242
2243 static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
2244   applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
2245                      edit::rewriteObjCRedundantCallWithLiteral);
2246 }
2247
2248 /// \brief Diagnose use of %s directive in an NSString which is being passed
2249 /// as formatting string to formatting method.
2250 static void
2251 DiagnoseCStringFormatDirectiveInObjCAPI(Sema &S,
2252                                         ObjCMethodDecl *Method,
2253                                         Selector Sel,
2254                                         Expr **Args, unsigned NumArgs) {
2255   unsigned Idx = 0;
2256   bool Format = false;
2257   ObjCStringFormatFamily SFFamily = Sel.getStringFormatFamily();
2258   if (SFFamily == ObjCStringFormatFamily::SFF_NSString) {
2259     Idx = 0;
2260     Format = true;
2261   }
2262   else if (Method) {
2263     for (const auto *I : Method->specific_attrs<FormatAttr>()) {
2264       if (S.GetFormatNSStringIdx(I, Idx)) {
2265         Format = true;
2266         break;
2267       }
2268     }
2269   }
2270   if (!Format || NumArgs <= Idx)
2271     return;
2272
2273   Expr *FormatExpr = Args[Idx];
2274   if (ObjCStringLiteral *OSL =
2275       dyn_cast<ObjCStringLiteral>(FormatExpr->IgnoreParenImpCasts())) {
2276     StringLiteral *FormatString = OSL->getString();
2277     if (S.FormatStringHasSArg(FormatString)) {
2278       S.Diag(FormatExpr->getExprLoc(), diag::warn_objc_cdirective_format_string)
2279         << "%s" << 0 << 0;
2280       if (Method)
2281         S.Diag(Method->getLocation(), diag::note_method_declared_at)
2282           << Method->getDeclName();
2283     }
2284   }
2285 }
2286
2287 /// \brief Build an Objective-C class message expression.
2288 ///
2289 /// This routine takes care of both normal class messages and
2290 /// class messages to the superclass.
2291 ///
2292 /// \param ReceiverTypeInfo Type source information that describes the
2293 /// receiver of this message. This may be NULL, in which case we are
2294 /// sending to the superclass and \p SuperLoc must be a valid source
2295 /// location.
2296
2297 /// \param ReceiverType The type of the object receiving the
2298 /// message. When \p ReceiverTypeInfo is non-NULL, this is the same
2299 /// type as that refers to. For a superclass send, this is the type of
2300 /// the superclass.
2301 ///
2302 /// \param SuperLoc The location of the "super" keyword in a
2303 /// superclass message.
2304 ///
2305 /// \param Sel The selector to which the message is being sent.
2306 ///
2307 /// \param Method The method that this class message is invoking, if
2308 /// already known.
2309 ///
2310 /// \param LBracLoc The location of the opening square bracket ']'.
2311 ///
2312 /// \param RBracLoc The location of the closing square bracket ']'.
2313 ///
2314 /// \param ArgsIn The message arguments.
2315 ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
2316                                    QualType ReceiverType,
2317                                    SourceLocation SuperLoc,
2318                                    Selector Sel,
2319                                    ObjCMethodDecl *Method,
2320                                    SourceLocation LBracLoc,
2321                                    ArrayRef<SourceLocation> SelectorLocs,
2322                                    SourceLocation RBracLoc,
2323                                    MultiExprArg ArgsIn,
2324                                    bool isImplicit) {
2325   SourceLocation Loc = SuperLoc.isValid()? SuperLoc
2326     : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
2327   if (LBracLoc.isInvalid()) {
2328     Diag(Loc, diag::err_missing_open_square_message_send)
2329       << FixItHint::CreateInsertion(Loc, "[");
2330     LBracLoc = Loc;
2331   }
2332   SourceLocation SelLoc;
2333   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2334     SelLoc = SelectorLocs.front();
2335   else
2336     SelLoc = Loc;
2337
2338   if (ReceiverType->isDependentType()) {
2339     // If the receiver type is dependent, we can't type-check anything
2340     // at this point. Build a dependent expression.
2341     unsigned NumArgs = ArgsIn.size();
2342     Expr **Args = ArgsIn.data();
2343     assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2344     return ObjCMessageExpr::Create(
2345         Context, ReceiverType, VK_RValue, LBracLoc, ReceiverTypeInfo, Sel,
2346         SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs), RBracLoc,
2347         isImplicit);
2348   }
2349
2350   // Find the class to which we are sending this message.
2351   ObjCInterfaceDecl *Class = nullptr;
2352   const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
2353   if (!ClassType || !(Class = ClassType->getInterface())) {
2354     Diag(Loc, diag::err_invalid_receiver_class_message)
2355       << ReceiverType;
2356     return ExprError();
2357   }
2358   assert(Class && "We don't know which class we're messaging?");
2359   // objc++ diagnoses during typename annotation.
2360   if (!getLangOpts().CPlusPlus)
2361     (void)DiagnoseUseOfDecl(Class, SelLoc);
2362   // Find the method we are messaging.
2363   if (!Method) {
2364     SourceRange TypeRange
2365       = SuperLoc.isValid()? SourceRange(SuperLoc)
2366                           : ReceiverTypeInfo->getTypeLoc().getSourceRange();
2367     if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class),
2368                             (getLangOpts().ObjCAutoRefCount
2369                                ? diag::err_arc_receiver_forward_class
2370                                : diag::warn_receiver_forward_class),
2371                             TypeRange)) {
2372       // A forward class used in messaging is treated as a 'Class'
2373       Method = LookupFactoryMethodInGlobalPool(Sel,
2374                                                SourceRange(LBracLoc, RBracLoc));
2375       if (Method && !getLangOpts().ObjCAutoRefCount)
2376         Diag(Method->getLocation(), diag::note_method_sent_forward_class)
2377           << Method->getDeclName();
2378     }
2379     if (!Method)
2380       Method = Class->lookupClassMethod(Sel);
2381
2382     // If we have an implementation in scope, check "private" methods.
2383     if (!Method)
2384       Method = Class->lookupPrivateClassMethod(Sel);
2385
2386     if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2387       return ExprError();
2388   }
2389
2390   // Check the argument types and determine the result type.
2391   QualType ReturnType;
2392   ExprValueKind VK = VK_RValue;
2393
2394   unsigned NumArgs = ArgsIn.size();
2395   Expr **Args = ArgsIn.data();
2396   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2397                                 Sel, SelectorLocs,
2398                                 Method, true,
2399                                 SuperLoc.isValid(), LBracLoc, RBracLoc,
2400                                 SourceRange(),
2401                                 ReturnType, VK))
2402     return ExprError();
2403
2404   if (Method && !Method->getReturnType()->isVoidType() &&
2405       RequireCompleteType(LBracLoc, Method->getReturnType(),
2406                           diag::err_illegal_message_expr_incomplete_type))
2407     return ExprError();
2408
2409   // Warn about explicit call of +initialize on its own class. But not on 'super'.
2410   if (Method && Method->getMethodFamily() == OMF_initialize) {
2411     if (!SuperLoc.isValid()) {
2412       const ObjCInterfaceDecl *ID =
2413         dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext());
2414       if (ID == Class) {
2415         Diag(Loc, diag::warn_direct_initialize_call);
2416         Diag(Method->getLocation(), diag::note_method_declared_at)
2417           << Method->getDeclName();
2418       }
2419     }
2420     else if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2421       // [super initialize] is allowed only within an +initialize implementation
2422       if (CurMeth->getMethodFamily() != OMF_initialize) {
2423         Diag(Loc, diag::warn_direct_super_initialize_call);
2424         Diag(Method->getLocation(), diag::note_method_declared_at)
2425           << Method->getDeclName();
2426         Diag(CurMeth->getLocation(), diag::note_method_declared_at)
2427         << CurMeth->getDeclName();
2428       }
2429     }
2430   }
2431
2432   DiagnoseCStringFormatDirectiveInObjCAPI(*this, Method, Sel, Args, NumArgs);
2433
2434   // Construct the appropriate ObjCMessageExpr.
2435   ObjCMessageExpr *Result;
2436   if (SuperLoc.isValid())
2437     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2438                                      SuperLoc, /*IsInstanceSuper=*/false,
2439                                      ReceiverType, Sel, SelectorLocs,
2440                                      Method, makeArrayRef(Args, NumArgs),
2441                                      RBracLoc, isImplicit);
2442   else {
2443     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2444                                      ReceiverTypeInfo, Sel, SelectorLocs,
2445                                      Method, makeArrayRef(Args, NumArgs),
2446                                      RBracLoc, isImplicit);
2447     if (!isImplicit)
2448       checkCocoaAPI(*this, Result);
2449   }
2450   return MaybeBindToTemporary(Result);
2451 }
2452
2453 // ActOnClassMessage - used for both unary and keyword messages.
2454 // ArgExprs is optional - if it is present, the number of expressions
2455 // is obtained from Sel.getNumArgs().
2456 ExprResult Sema::ActOnClassMessage(Scope *S,
2457                                    ParsedType Receiver,
2458                                    Selector Sel,
2459                                    SourceLocation LBracLoc,
2460                                    ArrayRef<SourceLocation> SelectorLocs,
2461                                    SourceLocation RBracLoc,
2462                                    MultiExprArg Args) {
2463   TypeSourceInfo *ReceiverTypeInfo;
2464   QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
2465   if (ReceiverType.isNull())
2466     return ExprError();
2467
2468
2469   if (!ReceiverTypeInfo)
2470     ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
2471
2472   return BuildClassMessage(ReceiverTypeInfo, ReceiverType,
2473                            /*SuperLoc=*/SourceLocation(), Sel,
2474                            /*Method=*/nullptr, LBracLoc, SelectorLocs, RBracLoc,
2475                            Args);
2476 }
2477
2478 ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
2479                                               QualType ReceiverType,
2480                                               SourceLocation Loc,
2481                                               Selector Sel,
2482                                               ObjCMethodDecl *Method,
2483                                               MultiExprArg Args) {
2484   return BuildInstanceMessage(Receiver, ReceiverType,
2485                               /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
2486                               Sel, Method, Loc, Loc, Loc, Args,
2487                               /*isImplicit=*/true);
2488 }
2489
2490 /// \brief Build an Objective-C instance message expression.
2491 ///
2492 /// This routine takes care of both normal instance messages and
2493 /// instance messages to the superclass instance.
2494 ///
2495 /// \param Receiver The expression that computes the object that will
2496 /// receive this message. This may be empty, in which case we are
2497 /// sending to the superclass instance and \p SuperLoc must be a valid
2498 /// source location.
2499 ///
2500 /// \param ReceiverType The (static) type of the object receiving the
2501 /// message. When a \p Receiver expression is provided, this is the
2502 /// same type as that expression. For a superclass instance send, this
2503 /// is a pointer to the type of the superclass.
2504 ///
2505 /// \param SuperLoc The location of the "super" keyword in a
2506 /// superclass instance message.
2507 ///
2508 /// \param Sel The selector to which the message is being sent.
2509 ///
2510 /// \param Method The method that this instance message is invoking, if
2511 /// already known.
2512 ///
2513 /// \param LBracLoc The location of the opening square bracket ']'.
2514 ///
2515 /// \param RBracLoc The location of the closing square bracket ']'.
2516 ///
2517 /// \param ArgsIn The message arguments.
2518 ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
2519                                       QualType ReceiverType,
2520                                       SourceLocation SuperLoc,
2521                                       Selector Sel,
2522                                       ObjCMethodDecl *Method,
2523                                       SourceLocation LBracLoc,
2524                                       ArrayRef<SourceLocation> SelectorLocs,
2525                                       SourceLocation RBracLoc,
2526                                       MultiExprArg ArgsIn,
2527                                       bool isImplicit) {
2528   // The location of the receiver.
2529   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
2530   SourceRange RecRange =
2531       SuperLoc.isValid()? SuperLoc : Receiver->getSourceRange();
2532   SourceLocation SelLoc;
2533   if (!SelectorLocs.empty() && SelectorLocs.front().isValid())
2534     SelLoc = SelectorLocs.front();
2535   else
2536     SelLoc = Loc;
2537
2538   if (LBracLoc.isInvalid()) {
2539     Diag(Loc, diag::err_missing_open_square_message_send)
2540       << FixItHint::CreateInsertion(Loc, "[");
2541     LBracLoc = Loc;
2542   }
2543
2544   // If we have a receiver expression, perform appropriate promotions
2545   // and determine receiver type.
2546   if (Receiver) {
2547     if (Receiver->hasPlaceholderType()) {
2548       ExprResult Result;
2549       if (Receiver->getType() == Context.UnknownAnyTy)
2550         Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
2551       else
2552         Result = CheckPlaceholderExpr(Receiver);
2553       if (Result.isInvalid()) return ExprError();
2554       Receiver = Result.get();
2555     }
2556
2557     if (Receiver->isTypeDependent()) {
2558       // If the receiver is type-dependent, we can't type-check anything
2559       // at this point. Build a dependent expression.
2560       unsigned NumArgs = ArgsIn.size();
2561       Expr **Args = ArgsIn.data();
2562       assert(SuperLoc.isInvalid() && "Message to super with dependent type");
2563       return ObjCMessageExpr::Create(
2564           Context, Context.DependentTy, VK_RValue, LBracLoc, Receiver, Sel,
2565           SelectorLocs, /*Method=*/nullptr, makeArrayRef(Args, NumArgs),
2566           RBracLoc, isImplicit);
2567     }
2568
2569     // If necessary, apply function/array conversion to the receiver.
2570     // C99 6.7.5.3p[7,8].
2571     ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
2572     if (Result.isInvalid())
2573       return ExprError();
2574     Receiver = Result.get();
2575     ReceiverType = Receiver->getType();
2576
2577     // If the receiver is an ObjC pointer, a block pointer, or an
2578     // __attribute__((NSObject)) pointer, we don't need to do any
2579     // special conversion in order to look up a receiver.
2580     if (ReceiverType->isObjCRetainableType()) {
2581       // do nothing
2582     } else if (!getLangOpts().ObjCAutoRefCount &&
2583                !Context.getObjCIdType().isNull() &&
2584                (ReceiverType->isPointerType() ||
2585                 ReceiverType->isIntegerType())) {
2586       // Implicitly convert integers and pointers to 'id' but emit a warning.
2587       // But not in ARC.
2588       Diag(Loc, diag::warn_bad_receiver_type)
2589         << ReceiverType
2590         << Receiver->getSourceRange();
2591       if (ReceiverType->isPointerType()) {
2592         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2593                                      CK_CPointerToObjCPointerCast).get();
2594       } else {
2595         // TODO: specialized warning on null receivers?
2596         bool IsNull = Receiver->isNullPointerConstant(Context,
2597                                               Expr::NPC_ValueDependentIsNull);
2598         CastKind Kind = IsNull ? CK_NullToPointer : CK_IntegralToPointer;
2599         Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
2600                                      Kind).get();
2601       }
2602       ReceiverType = Receiver->getType();
2603     } else if (getLangOpts().CPlusPlus) {
2604       // The receiver must be a complete type.
2605       if (RequireCompleteType(Loc, Receiver->getType(),
2606                               diag::err_incomplete_receiver_type))
2607         return ExprError();
2608
2609       ExprResult result = PerformContextuallyConvertToObjCPointer(Receiver);
2610       if (result.isUsable()) {
2611         Receiver = result.get();
2612         ReceiverType = Receiver->getType();
2613       }
2614     }
2615   }
2616
2617   // There's a somewhat weird interaction here where we assume that we
2618   // won't actually have a method unless we also don't need to do some
2619   // of the more detailed type-checking on the receiver.
2620
2621   if (!Method) {
2622     // Handle messages to id and __kindof types (where we use the
2623     // global method pool).
2624     // FIXME: The type bound is currently ignored by lookup in the
2625     // global pool.
2626     const ObjCObjectType *typeBound = nullptr;
2627     bool receiverIsIdLike = ReceiverType->isObjCIdOrObjectKindOfType(Context,
2628                                                                      typeBound);
2629     if (receiverIsIdLike || ReceiverType->isBlockPointerType() ||
2630         (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
2631       Method = LookupInstanceMethodInGlobalPool(Sel,
2632                                                 SourceRange(LBracLoc, RBracLoc),
2633                                                 receiverIsIdLike);
2634       if (!Method)
2635         Method = LookupFactoryMethodInGlobalPool(Sel,
2636                                                  SourceRange(LBracLoc,RBracLoc),
2637                                                  receiverIsIdLike);
2638       if (Method) {
2639         if (ObjCMethodDecl *BestMethod =
2640               SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod()))
2641           Method = BestMethod;
2642         if (!AreMultipleMethodsInGlobalPool(Sel, Method,
2643                                             SourceRange(LBracLoc, RBracLoc),
2644                                             receiverIsIdLike)) {
2645           DiagnoseUseOfDecl(Method, SelLoc);
2646         }
2647       }
2648     } else if (ReceiverType->isObjCClassOrClassKindOfType() ||
2649                ReceiverType->isObjCQualifiedClassType()) {
2650       // Handle messages to Class.
2651       // We allow sending a message to a qualified Class ("Class<foo>"), which
2652       // is ok as long as one of the protocols implements the selector (if not,
2653       // warn).
2654       if (!ReceiverType->isObjCClassOrClassKindOfType()) {
2655         const ObjCObjectPointerType *QClassTy
2656           = ReceiverType->getAsObjCQualifiedClassType();
2657         // Search protocols for class methods.
2658         Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
2659         if (!Method) {
2660           Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
2661           // warn if instance method found for a Class message.
2662           if (Method) {
2663             Diag(SelLoc, diag::warn_instance_method_on_class_found)
2664               << Method->getSelector() << Sel;
2665             Diag(Method->getLocation(), diag::note_method_declared_at)
2666               << Method->getDeclName();
2667           }
2668         }
2669       } else {
2670         if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
2671           if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
2672             // First check the public methods in the class interface.
2673             Method = ClassDecl->lookupClassMethod(Sel);
2674
2675             if (!Method)
2676               Method = ClassDecl->lookupPrivateClassMethod(Sel);
2677           }
2678           if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2679             return ExprError();
2680         }
2681         if (!Method) {
2682           // If not messaging 'self', look for any factory method named 'Sel'.
2683           if (!Receiver || !isSelfExpr(Receiver)) {
2684             Method = LookupFactoryMethodInGlobalPool(Sel,
2685                                                 SourceRange(LBracLoc, RBracLoc));
2686             if (!Method) {
2687               // If no class (factory) method was found, check if an _instance_
2688               // method of the same name exists in the root class only.
2689               Method = LookupInstanceMethodInGlobalPool(Sel,
2690                                                SourceRange(LBracLoc, RBracLoc));
2691               if (Method)
2692                   if (const ObjCInterfaceDecl *ID =
2693                       dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
2694                     if (ID->getSuperClass())
2695                       Diag(SelLoc, diag::warn_root_inst_method_not_found)
2696                       << Sel << SourceRange(LBracLoc, RBracLoc);
2697                   }
2698             }
2699             if (Method)
2700               if (ObjCMethodDecl *BestMethod =
2701                   SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod()))
2702                 Method = BestMethod;
2703           }
2704         }
2705       }
2706     } else {
2707       ObjCInterfaceDecl *ClassDecl = nullptr;
2708
2709       // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
2710       // long as one of the protocols implements the selector (if not, warn).
2711       // And as long as message is not deprecated/unavailable (warn if it is).
2712       if (const ObjCObjectPointerType *QIdTy
2713                                    = ReceiverType->getAsObjCQualifiedIdType()) {
2714         // Search protocols for instance methods.
2715         Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
2716         if (!Method)
2717           Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
2718         if (Method && DiagnoseUseOfDecl(Method, SelLoc))
2719           return ExprError();
2720       } else if (const ObjCObjectPointerType *OCIType
2721                    = ReceiverType->getAsObjCInterfacePointerType()) {
2722         // We allow sending a message to a pointer to an interface (an object).
2723         ClassDecl = OCIType->getInterfaceDecl();
2724
2725         // Try to complete the type. Under ARC, this is a hard error from which
2726         // we don't try to recover.
2727         // FIXME: In the non-ARC case, this will still be a hard error if the
2728         // definition is found in a module that's not visible.
2729         const ObjCInterfaceDecl *forwardClass = nullptr;
2730         if (RequireCompleteType(Loc, OCIType->getPointeeType(),
2731               getLangOpts().ObjCAutoRefCount
2732                 ? diag::err_arc_receiver_forward_instance
2733                 : diag::warn_receiver_forward_instance,
2734                                 Receiver? Receiver->getSourceRange()
2735                                         : SourceRange(SuperLoc))) {
2736           if (getLangOpts().ObjCAutoRefCount)
2737             return ExprError();
2738
2739           forwardClass = OCIType->getInterfaceDecl();
2740           Diag(Receiver ? Receiver->getLocStart()
2741                         : SuperLoc, diag::note_receiver_is_id);
2742           Method = nullptr;
2743         } else {
2744           Method = ClassDecl->lookupInstanceMethod(Sel);
2745         }
2746
2747         if (!Method)
2748           // Search protocol qualifiers.
2749           Method = LookupMethodInQualifiedType(Sel, OCIType, true);
2750
2751         if (!Method) {
2752           // If we have implementations in scope, check "private" methods.
2753           Method = ClassDecl->lookupPrivateMethod(Sel);
2754
2755           if (!Method && getLangOpts().ObjCAutoRefCount) {
2756             Diag(SelLoc, diag::err_arc_may_not_respond)
2757               << OCIType->getPointeeType() << Sel << RecRange
2758               << SourceRange(SelectorLocs.front(), SelectorLocs.back());
2759             return ExprError();
2760           }
2761
2762           if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
2763             // If we still haven't found a method, look in the global pool. This
2764             // behavior isn't very desirable, however we need it for GCC
2765             // compatibility. FIXME: should we deviate??
2766             if (OCIType->qual_empty()) {
2767               Method = LookupInstanceMethodInGlobalPool(Sel,
2768                                               SourceRange(LBracLoc, RBracLoc));
2769               if (Method) {
2770                 if (auto BestMethod =
2771                       SelectBestMethod(Sel, ArgsIn, Method->isInstanceMethod()))
2772                   Method = BestMethod;
2773                 AreMultipleMethodsInGlobalPool(Sel, Method,
2774                                                SourceRange(LBracLoc, RBracLoc),
2775                                                true);
2776               }
2777               if (Method && !forwardClass)
2778                 Diag(SelLoc, diag::warn_maynot_respond)
2779                   << OCIType->getInterfaceDecl()->getIdentifier()
2780                   << Sel << RecRange;
2781             }
2782           }
2783         }
2784         if (Method && DiagnoseUseOfDecl(Method, SelLoc, forwardClass))
2785           return ExprError();
2786       } else {
2787         // Reject other random receiver types (e.g. structs).
2788         Diag(Loc, diag::err_bad_receiver_type)
2789           << ReceiverType << Receiver->getSourceRange();
2790         return ExprError();
2791       }
2792     }
2793   }
2794
2795   FunctionScopeInfo *DIFunctionScopeInfo =
2796     (Method && Method->getMethodFamily() == OMF_init)
2797       ? getEnclosingFunction() : nullptr;
2798
2799   if (DIFunctionScopeInfo &&
2800       DIFunctionScopeInfo->ObjCIsDesignatedInit &&
2801       (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2802     bool isDesignatedInitChain = false;
2803     if (SuperLoc.isValid()) {
2804       if (const ObjCObjectPointerType *
2805             OCIType = ReceiverType->getAsObjCInterfacePointerType()) {
2806         if (const ObjCInterfaceDecl *ID = OCIType->getInterfaceDecl()) {
2807           // Either we know this is a designated initializer or we
2808           // conservatively assume it because we don't know for sure.
2809           if (!ID->declaresOrInheritsDesignatedInitializers() ||
2810               ID->isDesignatedInitializer(Sel)) {
2811             isDesignatedInitChain = true;
2812             DIFunctionScopeInfo->ObjCWarnForNoDesignatedInitChain = false;
2813           }
2814         }
2815       }
2816     }
2817     if (!isDesignatedInitChain) {
2818       const ObjCMethodDecl *InitMethod = nullptr;
2819       bool isDesignated =
2820         getCurMethodDecl()->isDesignatedInitializerForTheInterface(&InitMethod);
2821       assert(isDesignated && InitMethod);
2822       (void)isDesignated;
2823       Diag(SelLoc, SuperLoc.isValid() ?
2824              diag::warn_objc_designated_init_non_designated_init_call :
2825              diag::warn_objc_designated_init_non_super_designated_init_call);
2826       Diag(InitMethod->getLocation(),
2827            diag::note_objc_designated_init_marked_here);
2828     }
2829   }
2830
2831   if (DIFunctionScopeInfo &&
2832       DIFunctionScopeInfo->ObjCIsSecondaryInit &&
2833       (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2834     if (SuperLoc.isValid()) {
2835       Diag(SelLoc, diag::warn_objc_secondary_init_super_init_call);
2836     } else {
2837       DIFunctionScopeInfo->ObjCWarnForNoInitDelegation = false;
2838     }
2839   }
2840
2841   // Check the message arguments.
2842   unsigned NumArgs = ArgsIn.size();
2843   Expr **Args = ArgsIn.data();
2844   QualType ReturnType;
2845   ExprValueKind VK = VK_RValue;
2846   bool ClassMessage = (ReceiverType->isObjCClassType() ||
2847                        ReceiverType->isObjCQualifiedClassType());
2848   if (CheckMessageArgumentTypes(ReceiverType, MultiExprArg(Args, NumArgs),
2849                                 Sel, SelectorLocs, Method,
2850                                 ClassMessage, SuperLoc.isValid(),
2851                                 LBracLoc, RBracLoc, RecRange, ReturnType, VK))
2852     return ExprError();
2853
2854   if (Method && !Method->getReturnType()->isVoidType() &&
2855       RequireCompleteType(LBracLoc, Method->getReturnType(),
2856                           diag::err_illegal_message_expr_incomplete_type))
2857     return ExprError();
2858
2859   // In ARC, forbid the user from sending messages to
2860   // retain/release/autorelease/dealloc/retainCount explicitly.
2861   if (getLangOpts().ObjCAutoRefCount) {
2862     ObjCMethodFamily family =
2863       (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
2864     switch (family) {
2865     case OMF_init:
2866       if (Method)
2867         checkInitMethod(Method, ReceiverType);
2868
2869     case OMF_None:
2870     case OMF_alloc:
2871     case OMF_copy:
2872     case OMF_finalize:
2873     case OMF_mutableCopy:
2874     case OMF_new:
2875     case OMF_self:
2876     case OMF_initialize:
2877       break;
2878
2879     case OMF_dealloc:
2880     case OMF_retain:
2881     case OMF_release:
2882     case OMF_autorelease:
2883     case OMF_retainCount:
2884       Diag(SelLoc, diag::err_arc_illegal_explicit_message)
2885         << Sel << RecRange;
2886       break;
2887
2888     case OMF_performSelector:
2889       if (Method && NumArgs >= 1) {
2890         if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
2891           Selector ArgSel = SelExp->getSelector();
2892           ObjCMethodDecl *SelMethod =
2893             LookupInstanceMethodInGlobalPool(ArgSel,
2894                                              SelExp->getSourceRange());
2895           if (!SelMethod)
2896             SelMethod =
2897               LookupFactoryMethodInGlobalPool(ArgSel,
2898                                               SelExp->getSourceRange());
2899           if (SelMethod) {
2900             ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
2901             switch (SelFamily) {
2902               case OMF_alloc:
2903               case OMF_copy:
2904               case OMF_mutableCopy:
2905               case OMF_new:
2906               case OMF_self:
2907               case OMF_init:
2908                 // Issue error, unless ns_returns_not_retained.
2909                 if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
2910                   // selector names a +1 method
2911                   Diag(SelLoc,
2912                        diag::err_arc_perform_selector_retains);
2913                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2914                     << SelMethod->getDeclName();
2915                 }
2916                 break;
2917               default:
2918                 // +0 call. OK. unless ns_returns_retained.
2919                 if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
2920                   // selector names a +1 method
2921                   Diag(SelLoc,
2922                        diag::err_arc_perform_selector_retains);
2923                   Diag(SelMethod->getLocation(), diag::note_method_declared_at)
2924                     << SelMethod->getDeclName();
2925                 }
2926                 break;
2927             }
2928           }
2929         } else {
2930           // error (may leak).
2931           Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
2932           Diag(Args[0]->getExprLoc(), diag::note_used_here);
2933         }
2934       }
2935       break;
2936     }
2937   }
2938
2939   DiagnoseCStringFormatDirectiveInObjCAPI(*this, Method, Sel, Args, NumArgs);
2940
2941   // Construct the appropriate ObjCMessageExpr instance.
2942   ObjCMessageExpr *Result;
2943   if (SuperLoc.isValid())
2944     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2945                                      SuperLoc,  /*IsInstanceSuper=*/true,
2946                                      ReceiverType, Sel, SelectorLocs, Method,
2947                                      makeArrayRef(Args, NumArgs), RBracLoc,
2948                                      isImplicit);
2949   else {
2950     Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
2951                                      Receiver, Sel, SelectorLocs, Method,
2952                                      makeArrayRef(Args, NumArgs), RBracLoc,
2953                                      isImplicit);
2954     if (!isImplicit)
2955       checkCocoaAPI(*this, Result);
2956   }
2957
2958   if (getLangOpts().ObjCAutoRefCount) {
2959     // In ARC, annotate delegate init calls.
2960     if (Result->getMethodFamily() == OMF_init &&
2961         (SuperLoc.isValid() || isSelfExpr(Receiver))) {
2962       // Only consider init calls *directly* in init implementations,
2963       // not within blocks.
2964       ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
2965       if (method && method->getMethodFamily() == OMF_init) {
2966         // The implicit assignment to self means we also don't want to
2967         // consume the result.
2968         Result->setDelegateInitCall(true);
2969         return Result;
2970       }
2971     }
2972
2973     // In ARC, check for message sends which are likely to introduce
2974     // retain cycles.
2975     checkRetainCycles(Result);
2976
2977     if (!isImplicit && Method) {
2978       if (const ObjCPropertyDecl *Prop = Method->findPropertyDecl()) {
2979         bool IsWeak =
2980           Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak;
2981         if (!IsWeak && Sel.isUnarySelector())
2982           IsWeak = ReturnType.getObjCLifetime() & Qualifiers::OCL_Weak;
2983         if (IsWeak &&
2984             !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, LBracLoc))
2985           getCurFunction()->recordUseOfWeak(Result, Prop);
2986       }
2987     }
2988   }
2989
2990   CheckObjCCircularContainer(Result);
2991
2992   return MaybeBindToTemporary(Result);
2993 }
2994
2995 static void RemoveSelectorFromWarningCache(Sema &S, Expr* Arg) {
2996   if (ObjCSelectorExpr *OSE =
2997       dyn_cast<ObjCSelectorExpr>(Arg->IgnoreParenCasts())) {
2998     Selector Sel = OSE->getSelector();
2999     SourceLocation Loc = OSE->getAtLoc();
3000     auto Pos = S.ReferencedSelectors.find(Sel);
3001     if (Pos != S.ReferencedSelectors.end() && Pos->second == Loc)
3002       S.ReferencedSelectors.erase(Pos);
3003   }
3004 }
3005
3006 // ActOnInstanceMessage - used for both unary and keyword messages.
3007 // ArgExprs is optional - if it is present, the number of expressions
3008 // is obtained from Sel.getNumArgs().
3009 ExprResult Sema::ActOnInstanceMessage(Scope *S,
3010                                       Expr *Receiver,
3011                                       Selector Sel,
3012                                       SourceLocation LBracLoc,
3013                                       ArrayRef<SourceLocation> SelectorLocs,
3014                                       SourceLocation RBracLoc,
3015                                       MultiExprArg Args) {
3016   if (!Receiver)
3017     return ExprError();
3018
3019   // A ParenListExpr can show up while doing error recovery with invalid code.
3020   if (isa<ParenListExpr>(Receiver)) {
3021     ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Receiver);
3022     if (Result.isInvalid()) return ExprError();
3023     Receiver = Result.get();
3024   }
3025
3026   if (RespondsToSelectorSel.isNull()) {
3027     IdentifierInfo *SelectorId = &Context.Idents.get("respondsToSelector");
3028     RespondsToSelectorSel = Context.Selectors.getUnarySelector(SelectorId);
3029   }
3030   if (Sel == RespondsToSelectorSel)
3031     RemoveSelectorFromWarningCache(*this, Args[0]);
3032
3033   return BuildInstanceMessage(Receiver, Receiver->getType(),
3034                               /*SuperLoc=*/SourceLocation(), Sel,
3035                               /*Method=*/nullptr, LBracLoc, SelectorLocs,
3036                               RBracLoc, Args);
3037 }
3038
3039 enum ARCConversionTypeClass {
3040   /// int, void, struct A
3041   ACTC_none,
3042
3043   /// id, void (^)()
3044   ACTC_retainable,
3045
3046   /// id*, id***, void (^*)(),
3047   ACTC_indirectRetainable,
3048
3049   /// void* might be a normal C type, or it might a CF type.
3050   ACTC_voidPtr,
3051
3052   /// struct A*
3053   ACTC_coreFoundation
3054 };
3055 static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
3056   return (ACTC == ACTC_retainable ||
3057           ACTC == ACTC_coreFoundation ||
3058           ACTC == ACTC_voidPtr);
3059 }
3060 static bool isAnyCLike(ARCConversionTypeClass ACTC) {
3061   return ACTC == ACTC_none ||
3062          ACTC == ACTC_voidPtr ||
3063          ACTC == ACTC_coreFoundation;
3064 }
3065
3066 static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
3067   bool isIndirect = false;
3068
3069   // Ignore an outermost reference type.
3070   if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
3071     type = ref->getPointeeType();
3072     isIndirect = true;
3073   }
3074
3075   // Drill through pointers and arrays recursively.
3076   while (true) {
3077     if (const PointerType *ptr = type->getAs<PointerType>()) {
3078       type = ptr->getPointeeType();
3079
3080       // The first level of pointer may be the innermost pointer on a CF type.
3081       if (!isIndirect) {
3082         if (type->isVoidType()) return ACTC_voidPtr;
3083         if (type->isRecordType()) return ACTC_coreFoundation;
3084       }
3085     } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
3086       type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
3087     } else {
3088       break;
3089     }
3090     isIndirect = true;
3091   }
3092
3093   if (isIndirect) {
3094     if (type->isObjCARCBridgableType())
3095       return ACTC_indirectRetainable;
3096     return ACTC_none;
3097   }
3098
3099   if (type->isObjCARCBridgableType())
3100     return ACTC_retainable;
3101
3102   return ACTC_none;
3103 }
3104
3105 namespace {
3106   /// A result from the cast checker.
3107   enum ACCResult {
3108     /// Cannot be casted.
3109     ACC_invalid,
3110
3111     /// Can be safely retained or not retained.
3112     ACC_bottom,
3113
3114     /// Can be casted at +0.
3115     ACC_plusZero,
3116
3117     /// Can be casted at +1.
3118     ACC_plusOne
3119   };
3120   ACCResult merge(ACCResult left, ACCResult right) {
3121     if (left == right) return left;
3122     if (left == ACC_bottom) return right;
3123     if (right == ACC_bottom) return left;
3124     return ACC_invalid;
3125   }
3126
3127   /// A checker which white-lists certain expressions whose conversion
3128   /// to or from retainable type would otherwise be forbidden in ARC.
3129   class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
3130     typedef StmtVisitor<ARCCastChecker, ACCResult> super;
3131
3132     ASTContext &Context;
3133     ARCConversionTypeClass SourceClass;
3134     ARCConversionTypeClass TargetClass;
3135     bool Diagnose;
3136
3137     static bool isCFType(QualType type) {
3138       // Someday this can use ns_bridged.  For now, it has to do this.
3139       return type->isCARCBridgableType();
3140     }
3141
3142   public:
3143     ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
3144                    ARCConversionTypeClass target, bool diagnose)
3145       : Context(Context), SourceClass(source), TargetClass(target),
3146         Diagnose(diagnose) {}
3147
3148     using super::Visit;
3149     ACCResult Visit(Expr *e) {
3150       return super::Visit(e->IgnoreParens());
3151     }
3152
3153     ACCResult VisitStmt(Stmt *s) {
3154       return ACC_invalid;
3155     }
3156
3157     /// Null pointer constants can be casted however you please.
3158     ACCResult VisitExpr(Expr *e) {
3159       if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
3160         return ACC_bottom;
3161       return ACC_invalid;
3162     }
3163
3164     /// Objective-C string literals can be safely casted.
3165     ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
3166       // If we're casting to any retainable type, go ahead.  Global
3167       // strings are immune to retains, so this is bottom.
3168       if (isAnyRetainable(TargetClass)) return ACC_bottom;
3169
3170       return ACC_invalid;
3171     }
3172
3173     /// Look through certain implicit and explicit casts.
3174     ACCResult VisitCastExpr(CastExpr *e) {
3175       switch (e->getCastKind()) {
3176         case CK_NullToPointer:
3177           return ACC_bottom;
3178
3179         case CK_NoOp:
3180         case CK_LValueToRValue:
3181         case CK_BitCast:
3182         case CK_CPointerToObjCPointerCast:
3183         case CK_BlockPointerToObjCPointerCast:
3184         case CK_AnyPointerToBlockPointerCast:
3185           return Visit(e->getSubExpr());
3186
3187         default:
3188           return ACC_invalid;
3189       }
3190     }
3191
3192     /// Look through unary extension.
3193     ACCResult VisitUnaryExtension(UnaryOperator *e) {
3194       return Visit(e->getSubExpr());
3195     }
3196
3197     /// Ignore the LHS of a comma operator.
3198     ACCResult VisitBinComma(BinaryOperator *e) {
3199       return Visit(e->getRHS());
3200     }
3201
3202     /// Conditional operators are okay if both sides are okay.
3203     ACCResult VisitConditionalOperator(ConditionalOperator *e) {
3204       ACCResult left = Visit(e->getTrueExpr());
3205       if (left == ACC_invalid) return ACC_invalid;
3206       return merge(left, Visit(e->getFalseExpr()));
3207     }
3208
3209     /// Look through pseudo-objects.
3210     ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
3211       // If we're getting here, we should always have a result.
3212       return Visit(e->getResultExpr());
3213     }
3214
3215     /// Statement expressions are okay if their result expression is okay.
3216     ACCResult VisitStmtExpr(StmtExpr *e) {
3217       return Visit(e->getSubStmt()->body_back());
3218     }
3219
3220     /// Some declaration references are okay.
3221     ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
3222       VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
3223       // References to global constants are okay.
3224       if (isAnyRetainable(TargetClass) &&
3225           isAnyRetainable(SourceClass) &&
3226           var &&
3227           var->getStorageClass() == SC_Extern &&
3228           var->getType().isConstQualified()) {
3229
3230         // In system headers, they can also be assumed to be immune to retains.
3231         // These are things like 'kCFStringTransformToLatin'.
3232         if (Context.getSourceManager().isInSystemHeader(var->getLocation()))
3233           return ACC_bottom;
3234
3235         return ACC_plusZero;
3236       }
3237
3238       // Nothing else.
3239       return ACC_invalid;
3240     }
3241
3242     /// Some calls are okay.
3243     ACCResult VisitCallExpr(CallExpr *e) {
3244       if (FunctionDecl *fn = e->getDirectCallee())
3245         if (ACCResult result = checkCallToFunction(fn))
3246           return result;
3247
3248       return super::VisitCallExpr(e);
3249     }
3250
3251     ACCResult checkCallToFunction(FunctionDecl *fn) {
3252       // Require a CF*Ref return type.
3253       if (!isCFType(fn->getReturnType()))
3254         return ACC_invalid;
3255
3256       if (!isAnyRetainable(TargetClass))
3257         return ACC_invalid;
3258
3259       // Honor an explicit 'not retained' attribute.
3260       if (fn->hasAttr<CFReturnsNotRetainedAttr>())
3261         return ACC_plusZero;
3262
3263       // Honor an explicit 'retained' attribute, except that for
3264       // now we're not going to permit implicit handling of +1 results,
3265       // because it's a bit frightening.
3266       if (fn->hasAttr<CFReturnsRetainedAttr>())
3267         return Diagnose ? ACC_plusOne
3268                         : ACC_invalid; // ACC_plusOne if we start accepting this
3269
3270       // Recognize this specific builtin function, which is used by CFSTR.
3271       unsigned builtinID = fn->getBuiltinID();
3272       if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
3273         return ACC_bottom;
3274
3275       // Otherwise, don't do anything implicit with an unaudited function.
3276       if (!fn->hasAttr<CFAuditedTransferAttr>())
3277         return ACC_invalid;
3278
3279       // Otherwise, it's +0 unless it follows the create convention.
3280       if (ento::coreFoundation::followsCreateRule(fn))
3281         return Diagnose ? ACC_plusOne
3282                         : ACC_invalid; // ACC_plusOne if we start accepting this
3283
3284       return ACC_plusZero;
3285     }
3286
3287     ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
3288       return checkCallToMethod(e->getMethodDecl());
3289     }
3290
3291     ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
3292       ObjCMethodDecl *method;
3293       if (e->isExplicitProperty())
3294         method = e->getExplicitProperty()->getGetterMethodDecl();
3295       else
3296         method = e->getImplicitPropertyGetter();
3297       return checkCallToMethod(method);
3298     }
3299
3300     ACCResult checkCallToMethod(ObjCMethodDecl *method) {
3301       if (!method) return ACC_invalid;
3302
3303       // Check for message sends to functions returning CF types.  We
3304       // just obey the Cocoa conventions with these, even though the
3305       // return type is CF.
3306       if (!isAnyRetainable(TargetClass) || !isCFType(method->getReturnType()))
3307         return ACC_invalid;
3308
3309       // If the method is explicitly marked not-retained, it's +0.
3310       if (method->hasAttr<CFReturnsNotRetainedAttr>())
3311         return ACC_plusZero;
3312
3313       // If the method is explicitly marked as returning retained, or its
3314       // selector follows a +1 Cocoa convention, treat it as +1.
3315       if (method->hasAttr<CFReturnsRetainedAttr>())
3316         return ACC_plusOne;
3317
3318       switch (method->getSelector().getMethodFamily()) {
3319       case OMF_alloc:
3320       case OMF_copy:
3321       case OMF_mutableCopy:
3322       case OMF_new:
3323         return ACC_plusOne;
3324
3325       default:
3326         // Otherwise, treat it as +0.
3327         return ACC_plusZero;
3328       }
3329     }
3330   };
3331 }
3332
3333 bool Sema::isKnownName(StringRef name) {
3334   if (name.empty())
3335     return false;
3336   LookupResult R(*this, &Context.Idents.get(name), SourceLocation(),
3337                  Sema::LookupOrdinaryName);
3338   return LookupName(R, TUScope, false);
3339 }
3340
3341 static void addFixitForObjCARCConversion(Sema &S,
3342                                          DiagnosticBuilder &DiagB,
3343                                          Sema::CheckedConversionKind CCK,
3344                                          SourceLocation afterLParen,
3345                                          QualType castType,
3346                                          Expr *castExpr,
3347                                          Expr *realCast,
3348                                          const char *bridgeKeyword,
3349                                          const char *CFBridgeName) {
3350   // We handle C-style and implicit casts here.
3351   switch (CCK) {
3352   case Sema::CCK_ImplicitConversion:
3353   case Sema::CCK_CStyleCast:
3354   case Sema::CCK_OtherCast:
3355     break;
3356   case Sema::CCK_FunctionalCast:
3357     return;
3358   }
3359
3360   if (CFBridgeName) {
3361     if (CCK == Sema::CCK_OtherCast) {
3362       if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
3363         SourceRange range(NCE->getOperatorLoc(),
3364                           NCE->getAngleBrackets().getEnd());
3365         SmallString<32> BridgeCall;
3366
3367         SourceManager &SM = S.getSourceManager();
3368         char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
3369         if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
3370           BridgeCall += ' ';
3371
3372         BridgeCall += CFBridgeName;
3373         DiagB.AddFixItHint(FixItHint::CreateReplacement(range, BridgeCall));
3374       }
3375       return;
3376     }
3377     Expr *castedE = castExpr;
3378     if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
3379       castedE = CCE->getSubExpr();
3380     castedE = castedE->IgnoreImpCasts();
3381     SourceRange range = castedE->getSourceRange();
3382
3383     SmallString<32> BridgeCall;
3384
3385     SourceManager &SM = S.getSourceManager();
3386     char PrevChar = *SM.getCharacterData(range.getBegin().getLocWithOffset(-1));
3387     if (Lexer::isIdentifierBodyChar(PrevChar, S.getLangOpts()))
3388       BridgeCall += ' ';
3389
3390     BridgeCall += CFBridgeName;
3391
3392     if (isa<ParenExpr>(castedE)) {
3393       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3394                          BridgeCall));
3395     } else {
3396       BridgeCall += '(';
3397       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3398                                                     BridgeCall));
3399       DiagB.AddFixItHint(FixItHint::CreateInsertion(
3400                                        S.getLocForEndOfToken(range.getEnd()),
3401                                        ")"));
3402     }
3403     return;
3404   }
3405
3406   if (CCK == Sema::CCK_CStyleCast) {
3407     DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
3408   } else if (CCK == Sema::CCK_OtherCast) {
3409     if (const CXXNamedCastExpr *NCE = dyn_cast<CXXNamedCastExpr>(realCast)) {
3410       std::string castCode = "(";
3411       castCode += bridgeKeyword;
3412       castCode += castType.getAsString();
3413       castCode += ")";
3414       SourceRange Range(NCE->getOperatorLoc(),
3415                         NCE->getAngleBrackets().getEnd());
3416       DiagB.AddFixItHint(FixItHint::CreateReplacement(Range, castCode));
3417     }
3418   } else {
3419     std::string castCode = "(";
3420     castCode += bridgeKeyword;
3421     castCode += castType.getAsString();
3422     castCode += ")";
3423     Expr *castedE = castExpr->IgnoreImpCasts();
3424     SourceRange range = castedE->getSourceRange();
3425     if (isa<ParenExpr>(castedE)) {
3426       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3427                          castCode));
3428     } else {
3429       castCode += "(";
3430       DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
3431                                                     castCode));
3432       DiagB.AddFixItHint(FixItHint::CreateInsertion(
3433                                        S.getLocForEndOfToken(range.getEnd()),
3434                                        ")"));
3435     }
3436   }
3437 }
3438
3439 template <typename T>
3440 static inline T *getObjCBridgeAttr(const TypedefType *TD) {
3441   TypedefNameDecl *TDNDecl = TD->getDecl();
3442   QualType QT = TDNDecl->getUnderlyingType();
3443   if (QT->isPointerType()) {
3444     QT = QT->getPointeeType();
3445     if (const RecordType *RT = QT->getAs<RecordType>())
3446       if (RecordDecl *RD = RT->getDecl()->getMostRecentDecl())
3447         return RD->getAttr<T>();
3448   }
3449   return nullptr;
3450 }
3451
3452 static ObjCBridgeRelatedAttr *ObjCBridgeRelatedAttrFromType(QualType T,
3453                                                             TypedefNameDecl *&TDNDecl) {
3454   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3455     TDNDecl = TD->getDecl();
3456     if (ObjCBridgeRelatedAttr *ObjCBAttr =
3457         getObjCBridgeAttr<ObjCBridgeRelatedAttr>(TD))
3458       return ObjCBAttr;
3459     T = TDNDecl->getUnderlyingType();
3460   }
3461   return nullptr;
3462 }
3463
3464 static void
3465 diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
3466                           QualType castType, ARCConversionTypeClass castACTC,
3467                           Expr *castExpr, Expr *realCast,
3468                           ARCConversionTypeClass exprACTC,
3469                           Sema::CheckedConversionKind CCK) {
3470   SourceLocation loc =
3471     (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
3472
3473   if (S.makeUnavailableInSystemHeader(loc,
3474                                  UnavailableAttr::IR_ARCForbiddenConversion))
3475     return;
3476
3477   QualType castExprType = castExpr->getType();
3478   TypedefNameDecl *TDNDecl = nullptr;
3479   if ((castACTC == ACTC_coreFoundation &&  exprACTC == ACTC_retainable &&
3480        ObjCBridgeRelatedAttrFromType(castType, TDNDecl)) ||
3481       (exprACTC == ACTC_coreFoundation && castACTC == ACTC_retainable &&
3482        ObjCBridgeRelatedAttrFromType(castExprType, TDNDecl)))
3483     return;
3484
3485   unsigned srcKind = 0;
3486   switch (exprACTC) {
3487   case ACTC_none:
3488   case ACTC_coreFoundation:
3489   case ACTC_voidPtr:
3490     srcKind = (castExprType->isPointerType() ? 1 : 0);
3491     break;
3492   case ACTC_retainable:
3493     srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
3494     break;
3495   case ACTC_indirectRetainable:
3496     srcKind = 4;
3497     break;
3498   }
3499
3500   // Check whether this could be fixed with a bridge cast.
3501   SourceLocation afterLParen = S.getLocForEndOfToken(castRange.getBegin());
3502   SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
3503
3504   // Bridge from an ARC type to a CF type.
3505   if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
3506
3507     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3508       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3509       << 2 // of C pointer type
3510       << castExprType
3511       << unsigned(castType->isBlockPointerType()) // to ObjC|block type
3512       << castType
3513       << castRange
3514       << castExpr->getSourceRange();
3515     bool br = S.isKnownName("CFBridgingRelease");
3516     ACCResult CreateRule =
3517       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3518     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3519     if (CreateRule != ACC_plusOne)
3520     {
3521       DiagnosticBuilder DiagB =
3522         (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3523                               : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3524
3525       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3526                                    castType, castExpr, realCast, "__bridge ",
3527                                    nullptr);
3528     }
3529     if (CreateRule != ACC_plusZero)
3530     {
3531       DiagnosticBuilder DiagB =
3532         (CCK == Sema::CCK_OtherCast && !br) ?
3533           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_transfer) << castExprType :
3534           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3535                  diag::note_arc_bridge_transfer)
3536             << castExprType << br;
3537
3538       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3539                                    castType, castExpr, realCast, "__bridge_transfer ",
3540                                    br ? "CFBridgingRelease" : nullptr);
3541     }
3542
3543     return;
3544   }
3545
3546   // Bridge from a CF type to an ARC type.
3547   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
3548     bool br = S.isKnownName("CFBridgingRetain");
3549     S.Diag(loc, diag::err_arc_cast_requires_bridge)
3550       << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
3551       << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
3552       << castExprType
3553       << 2 // to C pointer type
3554       << castType
3555       << castRange
3556       << castExpr->getSourceRange();
3557     ACCResult CreateRule =
3558       ARCCastChecker(S.Context, exprACTC, castACTC, true).Visit(castExpr);
3559     assert(CreateRule != ACC_bottom && "This cast should already be accepted.");
3560     if (CreateRule != ACC_plusOne)
3561     {
3562       DiagnosticBuilder DiagB =
3563       (CCK != Sema::CCK_OtherCast) ? S.Diag(noteLoc, diag::note_arc_bridge)
3564                                : S.Diag(noteLoc, diag::note_arc_cstyle_bridge);
3565       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3566                                    castType, castExpr, realCast, "__bridge ",
3567                                    nullptr);
3568     }
3569     if (CreateRule != ACC_plusZero)
3570     {
3571       DiagnosticBuilder DiagB =
3572         (CCK == Sema::CCK_OtherCast && !br) ?
3573           S.Diag(noteLoc, diag::note_arc_cstyle_bridge_retained) << castType :
3574           S.Diag(br ? castExpr->getExprLoc() : noteLoc,
3575                  diag::note_arc_bridge_retained)
3576             << castType << br;
3577
3578       addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
3579                                    castType, castExpr, realCast, "__bridge_retained ",
3580                                    br ? "CFBridgingRetain" : nullptr);
3581     }
3582
3583     return;
3584   }
3585
3586   S.Diag(loc, diag::err_arc_mismatched_cast)
3587     << (CCK != Sema::CCK_ImplicitConversion)
3588     << srcKind << castExprType << castType
3589     << castRange << castExpr->getSourceRange();
3590 }
3591
3592 template <typename TB>
3593 static bool CheckObjCBridgeNSCast(Sema &S, QualType castType, Expr *castExpr,
3594                                   bool &HadTheAttribute, bool warn) {
3595   QualType T = castExpr->getType();
3596   HadTheAttribute = false;
3597   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3598     TypedefNameDecl *TDNDecl = TD->getDecl();
3599     if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
3600       if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
3601         HadTheAttribute = true;
3602         if (Parm->isStr("id"))
3603           return true;
3604
3605         NamedDecl *Target = nullptr;
3606         // Check for an existing type with this name.
3607         LookupResult R(S, DeclarationName(Parm), SourceLocation(),
3608                        Sema::LookupOrdinaryName);
3609         if (S.LookupName(R, S.TUScope)) {
3610           Target = R.getFoundDecl();
3611           if (Target && isa<ObjCInterfaceDecl>(Target)) {
3612             ObjCInterfaceDecl *ExprClass = cast<ObjCInterfaceDecl>(Target);
3613             if (const ObjCObjectPointerType *InterfacePointerType =
3614                   castType->getAsObjCInterfacePointerType()) {
3615               ObjCInterfaceDecl *CastClass
3616                 = InterfacePointerType->getObjectType()->getInterface();
3617               if ((CastClass == ExprClass) ||
3618                   (CastClass && CastClass->isSuperClassOf(ExprClass)))
3619                 return true;
3620               if (warn)
3621                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge)
3622                   << T << Target->getName() << castType->getPointeeType();
3623               return false;
3624             } else if (castType->isObjCIdType() ||
3625                        (S.Context.ObjCObjectAdoptsQTypeProtocols(
3626                           castType, ExprClass)))
3627               // ok to cast to 'id'.
3628               // casting to id<p-list> is ok if bridge type adopts all of
3629               // p-list protocols.
3630               return true;
3631             else {
3632               if (warn) {
3633                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge)
3634                   << T << Target->getName() << castType;
3635                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3636                 S.Diag(Target->getLocStart(), diag::note_declared_at);
3637               }
3638               return false;
3639            }
3640           }
3641         } else if (!castType->isObjCIdType()) {
3642           S.Diag(castExpr->getLocStart(), diag::err_objc_cf_bridged_not_interface)
3643             << castExpr->getType() << Parm;
3644           S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3645           if (Target)
3646             S.Diag(Target->getLocStart(), diag::note_declared_at);
3647         }
3648         return true;
3649       }
3650       return false;
3651     }
3652     T = TDNDecl->getUnderlyingType();
3653   }
3654   return true;
3655 }
3656
3657 template <typename TB>
3658 static bool CheckObjCBridgeCFCast(Sema &S, QualType castType, Expr *castExpr,
3659                                   bool &HadTheAttribute, bool warn) {
3660   QualType T = castType;
3661   HadTheAttribute = false;
3662   while (const TypedefType *TD = dyn_cast<TypedefType>(T.getTypePtr())) {
3663     TypedefNameDecl *TDNDecl = TD->getDecl();
3664     if (TB *ObjCBAttr = getObjCBridgeAttr<TB>(TD)) {
3665       if (IdentifierInfo *Parm = ObjCBAttr->getBridgedType()) {
3666         HadTheAttribute = true;
3667         if (Parm->isStr("id"))
3668           return true;
3669
3670         NamedDecl *Target = nullptr;
3671         // Check for an existing type with this name.
3672         LookupResult R(S, DeclarationName(Parm), SourceLocation(),
3673                        Sema::LookupOrdinaryName);
3674         if (S.LookupName(R, S.TUScope)) {
3675           Target = R.getFoundDecl();
3676           if (Target && isa<ObjCInterfaceDecl>(Target)) {
3677             ObjCInterfaceDecl *CastClass = cast<ObjCInterfaceDecl>(Target);
3678             if (const ObjCObjectPointerType *InterfacePointerType =
3679                   castExpr->getType()->getAsObjCInterfacePointerType()) {
3680               ObjCInterfaceDecl *ExprClass
3681                 = InterfacePointerType->getObjectType()->getInterface();
3682               if ((CastClass == ExprClass) ||
3683                   (ExprClass && CastClass->isSuperClassOf(ExprClass)))
3684                 return true;
3685               if (warn) {
3686                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge_to_cf)
3687                   << castExpr->getType()->getPointeeType() << T;
3688                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3689               }
3690               return false;
3691             } else if (castExpr->getType()->isObjCIdType() ||
3692                        (S.Context.QIdProtocolsAdoptObjCObjectProtocols(
3693                           castExpr->getType(), CastClass)))
3694               // ok to cast an 'id' expression to a CFtype.
3695               // ok to cast an 'id<plist>' expression to CFtype provided plist
3696               // adopts all of CFtype's ObjetiveC's class plist.
3697               return true;
3698             else {
3699               if (warn) {
3700                 S.Diag(castExpr->getLocStart(), diag::warn_objc_invalid_bridge_to_cf)
3701                   << castExpr->getType() << castType;
3702                 S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3703                 S.Diag(Target->getLocStart(), diag::note_declared_at);
3704               }
3705               return false;
3706             }
3707           }
3708         }
3709         S.Diag(castExpr->getLocStart(), diag::err_objc_ns_bridged_invalid_cfobject)
3710         << castExpr->getType() << castType;
3711         S.Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3712         if (Target)
3713           S.Diag(Target->getLocStart(), diag::note_declared_at);
3714         return true;
3715       }
3716       return false;
3717     }
3718     T = TDNDecl->getUnderlyingType();
3719   }
3720   return true;
3721 }
3722
3723 void Sema::CheckTollFreeBridgeCast(QualType castType, Expr *castExpr) {
3724   if (!getLangOpts().ObjC1)
3725     return;
3726   // warn in presence of __bridge casting to or from a toll free bridge cast.
3727   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExpr->getType());
3728   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
3729   if (castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) {
3730     bool HasObjCBridgeAttr;
3731     bool ObjCBridgeAttrWillNotWarn =
3732       CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3733                                             false);
3734     if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
3735       return;
3736     bool HasObjCBridgeMutableAttr;
3737     bool ObjCBridgeMutableAttrWillNotWarn =
3738       CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3739                                                    HasObjCBridgeMutableAttr, false);
3740     if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
3741       return;
3742
3743     if (HasObjCBridgeAttr)
3744       CheckObjCBridgeNSCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3745                                             true);
3746     else if (HasObjCBridgeMutableAttr)
3747       CheckObjCBridgeNSCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3748                                                    HasObjCBridgeMutableAttr, true);
3749   }
3750   else if (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable) {
3751     bool HasObjCBridgeAttr;
3752     bool ObjCBridgeAttrWillNotWarn =
3753       CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3754                                             false);
3755     if (ObjCBridgeAttrWillNotWarn && HasObjCBridgeAttr)
3756       return;
3757     bool HasObjCBridgeMutableAttr;
3758     bool ObjCBridgeMutableAttrWillNotWarn =
3759       CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3760                                                    HasObjCBridgeMutableAttr, false);
3761     if (ObjCBridgeMutableAttrWillNotWarn && HasObjCBridgeMutableAttr)
3762       return;
3763
3764     if (HasObjCBridgeAttr)
3765       CheckObjCBridgeCFCast<ObjCBridgeAttr>(*this, castType, castExpr, HasObjCBridgeAttr,
3766                                             true);
3767     else if (HasObjCBridgeMutableAttr)
3768       CheckObjCBridgeCFCast<ObjCBridgeMutableAttr>(*this, castType, castExpr,
3769                                                    HasObjCBridgeMutableAttr, true);
3770   }
3771 }
3772
3773 void Sema::CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr) {
3774   QualType SrcType = castExpr->getType();
3775   if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(castExpr)) {
3776     if (PRE->isExplicitProperty()) {
3777       if (ObjCPropertyDecl *PDecl = PRE->getExplicitProperty())
3778         SrcType = PDecl->getType();
3779     }
3780     else if (PRE->isImplicitProperty()) {
3781       if (ObjCMethodDecl *Getter = PRE->getImplicitPropertyGetter())
3782         SrcType = Getter->getReturnType();
3783
3784     }
3785   }
3786
3787   ARCConversionTypeClass srcExprACTC = classifyTypeForARCConversion(SrcType);
3788   ARCConversionTypeClass castExprACTC = classifyTypeForARCConversion(castType);
3789   if (srcExprACTC != ACTC_retainable || castExprACTC != ACTC_coreFoundation)
3790     return;
3791   CheckObjCBridgeRelatedConversions(castExpr->getLocStart(),
3792                                     castType, SrcType, castExpr);
3793   return;
3794 }
3795
3796 bool Sema::CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
3797                                          CastKind &Kind) {
3798   if (!getLangOpts().ObjC1)
3799     return false;
3800   ARCConversionTypeClass exprACTC =
3801     classifyTypeForARCConversion(castExpr->getType());
3802   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(castType);
3803   if ((castACTC == ACTC_retainable && exprACTC == ACTC_coreFoundation) ||
3804       (castACTC == ACTC_coreFoundation && exprACTC == ACTC_retainable)) {
3805     CheckTollFreeBridgeCast(castType, castExpr);
3806     Kind = (castACTC == ACTC_coreFoundation) ? CK_BitCast
3807                                              : CK_CPointerToObjCPointerCast;
3808     return true;
3809   }
3810   return false;
3811 }
3812
3813 bool Sema::checkObjCBridgeRelatedComponents(SourceLocation Loc,
3814                                             QualType DestType, QualType SrcType,
3815                                             ObjCInterfaceDecl *&RelatedClass,
3816                                             ObjCMethodDecl *&ClassMethod,
3817                                             ObjCMethodDecl *&InstanceMethod,
3818                                             TypedefNameDecl *&TDNDecl,
3819                                             bool CfToNs, bool Diagnose) {
3820   QualType T = CfToNs ? SrcType : DestType;
3821   ObjCBridgeRelatedAttr *ObjCBAttr = ObjCBridgeRelatedAttrFromType(T, TDNDecl);
3822   if (!ObjCBAttr)
3823     return false;
3824
3825   IdentifierInfo *RCId = ObjCBAttr->getRelatedClass();
3826   IdentifierInfo *CMId = ObjCBAttr->getClassMethod();
3827   IdentifierInfo *IMId = ObjCBAttr->getInstanceMethod();
3828   if (!RCId)
3829     return false;
3830   NamedDecl *Target = nullptr;
3831   // Check for an existing type with this name.
3832   LookupResult R(*this, DeclarationName(RCId), SourceLocation(),
3833                  Sema::LookupOrdinaryName);
3834   if (!LookupName(R, TUScope)) {
3835     if (Diagnose) {
3836       Diag(Loc, diag::err_objc_bridged_related_invalid_class) << RCId
3837             << SrcType << DestType;
3838       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3839     }
3840     return false;
3841   }
3842   Target = R.getFoundDecl();
3843   if (Target && isa<ObjCInterfaceDecl>(Target))
3844     RelatedClass = cast<ObjCInterfaceDecl>(Target);
3845   else {
3846     if (Diagnose) {
3847       Diag(Loc, diag::err_objc_bridged_related_invalid_class_name) << RCId
3848             << SrcType << DestType;
3849       Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3850       if (Target)
3851         Diag(Target->getLocStart(), diag::note_declared_at);
3852     }
3853     return false;
3854   }
3855
3856   // Check for an existing class method with the given selector name.
3857   if (CfToNs && CMId) {
3858     Selector Sel = Context.Selectors.getUnarySelector(CMId);
3859     ClassMethod = RelatedClass->lookupMethod(Sel, false);
3860     if (!ClassMethod) {
3861       if (Diagnose) {
3862         Diag(Loc, diag::err_objc_bridged_related_known_method)
3863               << SrcType << DestType << Sel << false;
3864         Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3865       }
3866       return false;
3867     }
3868   }
3869
3870   // Check for an existing instance method with the given selector name.
3871   if (!CfToNs && IMId) {
3872     Selector Sel = Context.Selectors.getNullarySelector(IMId);
3873     InstanceMethod = RelatedClass->lookupMethod(Sel, true);
3874     if (!InstanceMethod) {
3875       if (Diagnose) {
3876         Diag(Loc, diag::err_objc_bridged_related_known_method)
3877               << SrcType << DestType << Sel << true;
3878         Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3879       }
3880       return false;
3881     }
3882   }
3883   return true;
3884 }
3885
3886 bool
3887 Sema::CheckObjCBridgeRelatedConversions(SourceLocation Loc,
3888                                         QualType DestType, QualType SrcType,
3889                                         Expr *&SrcExpr, bool Diagnose) {
3890   ARCConversionTypeClass rhsExprACTC = classifyTypeForARCConversion(SrcType);
3891   ARCConversionTypeClass lhsExprACTC = classifyTypeForARCConversion(DestType);
3892   bool CfToNs = (rhsExprACTC == ACTC_coreFoundation && lhsExprACTC == ACTC_retainable);
3893   bool NsToCf = (rhsExprACTC == ACTC_retainable && lhsExprACTC == ACTC_coreFoundation);
3894   if (!CfToNs && !NsToCf)
3895     return false;
3896
3897   ObjCInterfaceDecl *RelatedClass;
3898   ObjCMethodDecl *ClassMethod = nullptr;
3899   ObjCMethodDecl *InstanceMethod = nullptr;
3900   TypedefNameDecl *TDNDecl = nullptr;
3901   if (!checkObjCBridgeRelatedComponents(Loc, DestType, SrcType, RelatedClass,
3902                                         ClassMethod, InstanceMethod, TDNDecl,
3903                                         CfToNs, Diagnose))
3904     return false;
3905
3906   if (CfToNs) {
3907     // Implicit conversion from CF to ObjC object is needed.
3908     if (ClassMethod) {
3909       if (Diagnose) {
3910         std::string ExpressionString = "[";
3911         ExpressionString += RelatedClass->getNameAsString();
3912         ExpressionString += " ";
3913         ExpressionString += ClassMethod->getSelector().getAsString();
3914         SourceLocation SrcExprEndLoc = getLocForEndOfToken(SrcExpr->getLocEnd());
3915         // Provide a fixit: [RelatedClass ClassMethod SrcExpr]
3916         Diag(Loc, diag::err_objc_bridged_related_known_method)
3917           << SrcType << DestType << ClassMethod->getSelector() << false
3918           << FixItHint::CreateInsertion(SrcExpr->getLocStart(), ExpressionString)
3919           << FixItHint::CreateInsertion(SrcExprEndLoc, "]");
3920         Diag(RelatedClass->getLocStart(), diag::note_declared_at);
3921         Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3922       }
3923
3924       QualType receiverType = Context.getObjCInterfaceType(RelatedClass);
3925       // Argument.
3926       Expr *args[] = { SrcExpr };
3927       ExprResult msg = BuildClassMessageImplicit(receiverType, false,
3928                                       ClassMethod->getLocation(),
3929                                       ClassMethod->getSelector(), ClassMethod,
3930                                       MultiExprArg(args, 1));
3931       SrcExpr = msg.get();
3932       return true;
3933     }
3934   }
3935   else {
3936     // Implicit conversion from ObjC type to CF object is needed.
3937     if (InstanceMethod) {
3938       if (Diagnose) {
3939         std::string ExpressionString;
3940         SourceLocation SrcExprEndLoc =
3941             getLocForEndOfToken(SrcExpr->getLocEnd());
3942         if (InstanceMethod->isPropertyAccessor())
3943           if (const ObjCPropertyDecl *PDecl =
3944                   InstanceMethod->findPropertyDecl()) {
3945             // fixit: ObjectExpr.propertyname when it is  aproperty accessor.
3946             ExpressionString = ".";
3947             ExpressionString += PDecl->getNameAsString();
3948             Diag(Loc, diag::err_objc_bridged_related_known_method)
3949                 << SrcType << DestType << InstanceMethod->getSelector() << true
3950                 << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
3951           }
3952         if (ExpressionString.empty()) {
3953           // Provide a fixit: [ObjectExpr InstanceMethod]
3954           ExpressionString = " ";
3955           ExpressionString += InstanceMethod->getSelector().getAsString();
3956           ExpressionString += "]";
3957
3958           Diag(Loc, diag::err_objc_bridged_related_known_method)
3959               << SrcType << DestType << InstanceMethod->getSelector() << true
3960               << FixItHint::CreateInsertion(SrcExpr->getLocStart(), "[")
3961               << FixItHint::CreateInsertion(SrcExprEndLoc, ExpressionString);
3962         }
3963         Diag(RelatedClass->getLocStart(), diag::note_declared_at);
3964         Diag(TDNDecl->getLocStart(), diag::note_declared_at);
3965       }
3966
3967       ExprResult msg =
3968         BuildInstanceMessageImplicit(SrcExpr, SrcType,
3969                                      InstanceMethod->getLocation(),
3970                                      InstanceMethod->getSelector(),
3971                                      InstanceMethod, None);
3972       SrcExpr = msg.get();
3973       return true;
3974     }
3975   }
3976   return false;
3977 }
3978
3979 Sema::ARCConversionResult
3980 Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
3981                              Expr *&castExpr, CheckedConversionKind CCK,
3982                              bool Diagnose,
3983                              bool DiagnoseCFAudited,
3984                              BinaryOperatorKind Opc) {
3985   QualType castExprType = castExpr->getType();
3986
3987   // For the purposes of the classification, we assume reference types
3988   // will bind to temporaries.
3989   QualType effCastType = castType;
3990   if (const ReferenceType *ref = castType->getAs<ReferenceType>())
3991     effCastType = ref->getPointeeType();
3992
3993   ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
3994   ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
3995   if (exprACTC == castACTC) {
3996     // check for viablity and report error if casting an rvalue to a
3997     // life-time qualifier.
3998     if (Diagnose && castACTC == ACTC_retainable &&
3999         (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
4000         castType != castExprType) {
4001       const Type *DT = castType.getTypePtr();
4002       QualType QDT = castType;
4003       // We desugar some types but not others. We ignore those
4004       // that cannot happen in a cast; i.e. auto, and those which
4005       // should not be de-sugared; i.e typedef.
4006       if (const ParenType *PT = dyn_cast<ParenType>(DT))
4007         QDT = PT->desugar();
4008       else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
4009         QDT = TP->desugar();
4010       else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
4011         QDT = AT->desugar();
4012       if (QDT != castType &&
4013           QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
4014         SourceLocation loc =
4015           (castRange.isValid() ? castRange.getBegin()
4016                               : castExpr->getExprLoc());
4017         Diag(loc, diag::err_arc_nolifetime_behavior);
4018       }
4019     }
4020     return ACR_okay;
4021   }
4022
4023   if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
4024
4025   // Allow all of these types to be cast to integer types (but not
4026   // vice-versa).
4027   if (castACTC == ACTC_none && castType->isIntegralType(Context))
4028     return ACR_okay;
4029
4030   // Allow casts between pointers to lifetime types (e.g., __strong id*)
4031   // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
4032   // must be explicit.
4033   if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
4034     return ACR_okay;
4035   if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
4036       CCK != CCK_ImplicitConversion)
4037     return ACR_okay;
4038
4039   switch (ARCCastChecker(Context, exprACTC, castACTC, false).Visit(castExpr)) {
4040   // For invalid casts, fall through.
4041   case ACC_invalid:
4042     break;
4043
4044   // Do nothing for both bottom and +0.
4045   case ACC_bottom:
4046   case ACC_plusZero:
4047     return ACR_okay;
4048
4049   // If the result is +1, consume it here.
4050   case ACC_plusOne:
4051     castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
4052                                         CK_ARCConsumeObject, castExpr,
4053                                         nullptr, VK_RValue);
4054     ExprNeedsCleanups = true;
4055     return ACR_okay;
4056   }
4057
4058   // If this is a non-implicit cast from id or block type to a
4059   // CoreFoundation type, delay complaining in case the cast is used
4060   // in an acceptable context.
4061   if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
4062       CCK != CCK_ImplicitConversion)
4063     return ACR_unbridged;
4064
4065   // Do not issue bridge cast" diagnostic when implicit casting a cstring
4066   // to 'NSString *'. Let caller issue a normal mismatched diagnostic with
4067   // suitable fix-it.
4068   if (castACTC == ACTC_retainable && exprACTC == ACTC_none &&
4069       ConversionToObjCStringLiteralCheck(castType, castExpr, Diagnose))
4070     return ACR_okay;
4071
4072   // Do not issue "bridge cast" diagnostic when implicit casting
4073   // a retainable object to a CF type parameter belonging to an audited
4074   // CF API function. Let caller issue a normal type mismatched diagnostic
4075   // instead.
4076   if (Diagnose &&
4077       (!DiagnoseCFAudited || exprACTC != ACTC_retainable ||
4078         castACTC != ACTC_coreFoundation))
4079     if (!(exprACTC == ACTC_voidPtr && castACTC == ACTC_retainable &&
4080           (Opc == BO_NE || Opc == BO_EQ)))
4081       diagnoseObjCARCConversion(*this, castRange, castType, castACTC, castExpr,
4082                                 castExpr, exprACTC, CCK);
4083   return ACR_okay;
4084 }
4085
4086 /// Given that we saw an expression with the ARCUnbridgedCastTy
4087 /// placeholder type, complain bitterly.
4088 void Sema::diagnoseARCUnbridgedCast(Expr *e) {
4089   // We expect the spurious ImplicitCastExpr to already have been stripped.
4090   assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
4091   CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
4092
4093   SourceRange castRange;
4094   QualType castType;
4095   CheckedConversionKind CCK;
4096
4097   if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
4098     castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
4099     castType = cast->getTypeAsWritten();
4100     CCK = CCK_CStyleCast;
4101   } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
4102     castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
4103     castType = cast->getTypeAsWritten();
4104     CCK = CCK_OtherCast;
4105   } else {
4106     castType = cast->getType();
4107     CCK = CCK_ImplicitConversion;
4108   }
4109
4110   ARCConversionTypeClass castACTC =
4111     classifyTypeForARCConversion(castType.getNonReferenceType());
4112
4113   Expr *castExpr = realCast->getSubExpr();
4114   assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
4115
4116   diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
4117                             castExpr, realCast, ACTC_retainable, CCK);
4118 }
4119
4120 /// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
4121 /// type, remove the placeholder cast.
4122 Expr *Sema::stripARCUnbridgedCast(Expr *e) {
4123   assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
4124
4125   if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
4126     Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
4127     return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
4128   } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
4129     assert(uo->getOpcode() == UO_Extension);
4130     Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
4131     return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
4132                                    sub->getValueKind(), sub->getObjectKind(),
4133                                        uo->getOperatorLoc());
4134   } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
4135     assert(!gse->isResultDependent());
4136
4137     unsigned n = gse->getNumAssocs();
4138     SmallVector<Expr*, 4> subExprs(n);
4139     SmallVector<TypeSourceInfo*, 4> subTypes(n);
4140     for (unsigned i = 0; i != n; ++i) {
4141       subTypes[i] = gse->getAssocTypeSourceInfo(i);
4142       Expr *sub = gse->getAssocExpr(i);
4143       if (i == gse->getResultIndex())
4144         sub = stripARCUnbridgedCast(sub);
4145       subExprs[i] = sub;
4146     }
4147
4148     return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
4149                                               gse->getControllingExpr(),
4150                                               subTypes, subExprs,
4151                                               gse->getDefaultLoc(),
4152                                               gse->getRParenLoc(),
4153                                        gse->containsUnexpandedParameterPack(),
4154                                               gse->getResultIndex());
4155   } else {
4156     assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
4157     return cast<ImplicitCastExpr>(e)->getSubExpr();
4158   }
4159 }
4160
4161 bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
4162                                                  QualType exprType) {
4163   QualType canCastType =
4164     Context.getCanonicalType(castType).getUnqualifiedType();
4165   QualType canExprType =
4166     Context.getCanonicalType(exprType).getUnqualifiedType();
4167   if (isa<ObjCObjectPointerType>(canCastType) &&
4168       castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
4169       canExprType->isObjCObjectPointerType()) {
4170     if (const ObjCObjectPointerType *ObjT =
4171         canExprType->getAs<ObjCObjectPointerType>())
4172       if (const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl())
4173         return !ObjI->isArcWeakrefUnavailable();
4174   }
4175   return true;
4176 }
4177
4178 /// Look for an ObjCReclaimReturnedObject cast and destroy it.
4179 static Expr *maybeUndoReclaimObject(Expr *e) {
4180   // For now, we just undo operands that are *immediately* reclaim
4181   // expressions, which prevents the vast majority of potential
4182   // problems here.  To catch them all, we'd need to rebuild arbitrary
4183   // value-propagating subexpressions --- we can't reliably rebuild
4184   // in-place because of expression sharing.
4185   if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
4186     if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
4187       return ice->getSubExpr();
4188
4189   return e;
4190 }
4191
4192 ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
4193                                       ObjCBridgeCastKind Kind,
4194                                       SourceLocation BridgeKeywordLoc,
4195                                       TypeSourceInfo *TSInfo,
4196                                       Expr *SubExpr) {
4197   ExprResult SubResult = UsualUnaryConversions(SubExpr);
4198   if (SubResult.isInvalid()) return ExprError();
4199   SubExpr = SubResult.get();
4200
4201   QualType T = TSInfo->getType();
4202   QualType FromType = SubExpr->getType();
4203
4204   CastKind CK;
4205
4206   bool MustConsume = false;
4207   if (T->isDependentType() || SubExpr->isTypeDependent()) {
4208     // Okay: we'll build a dependent expression type.
4209     CK = CK_Dependent;
4210   } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
4211     // Casting CF -> id
4212     CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
4213                                   : CK_CPointerToObjCPointerCast);
4214     switch (Kind) {
4215     case OBC_Bridge:
4216       break;
4217
4218     case OBC_BridgeRetained: {
4219       bool br = isKnownName("CFBridgingRelease");
4220       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
4221         << 2
4222         << FromType
4223         << (T->isBlockPointerType()? 1 : 0)
4224         << T
4225         << SubExpr->getSourceRange()
4226         << Kind;
4227       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
4228         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
4229       Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
4230         << FromType << br
4231         << FixItHint::CreateReplacement(BridgeKeywordLoc,
4232                                         br ? "CFBridgingRelease "
4233                                            : "__bridge_transfer ");
4234
4235       Kind = OBC_Bridge;
4236       break;
4237     }
4238
4239     case OBC_BridgeTransfer:
4240       // We must consume the Objective-C object produced by the cast.
4241       MustConsume = true;
4242       break;
4243     }
4244   } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
4245     // Okay: id -> CF
4246     CK = CK_BitCast;
4247     switch (Kind) {
4248     case OBC_Bridge:
4249       // Reclaiming a value that's going to be __bridge-casted to CF
4250       // is very dangerous, so we don't do it.
4251       SubExpr = maybeUndoReclaimObject(SubExpr);
4252       break;
4253
4254     case OBC_BridgeRetained:
4255       // Produce the object before casting it.
4256       SubExpr = ImplicitCastExpr::Create(Context, FromType,
4257                                          CK_ARCProduceObject,
4258                                          SubExpr, nullptr, VK_RValue);
4259       break;
4260
4261     case OBC_BridgeTransfer: {
4262       bool br = isKnownName("CFBridgingRetain");
4263       Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
4264         << (FromType->isBlockPointerType()? 1 : 0)
4265         << FromType
4266         << 2
4267         << T
4268         << SubExpr->getSourceRange()
4269         << Kind;
4270
4271       Diag(BridgeKeywordLoc, diag::note_arc_bridge)
4272         << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
4273       Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
4274         << T << br
4275         << FixItHint::CreateReplacement(BridgeKeywordLoc,
4276                           br ? "CFBridgingRetain " : "__bridge_retained");
4277
4278       Kind = OBC_Bridge;
4279       break;
4280     }
4281     }
4282   } else {
4283     Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
4284       << FromType << T << Kind
4285       << SubExpr->getSourceRange()
4286       << TSInfo->getTypeLoc().getSourceRange();
4287     return ExprError();
4288   }
4289
4290   Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
4291                                                    BridgeKeywordLoc,
4292                                                    TSInfo, SubExpr);
4293
4294   if (MustConsume) {
4295     ExprNeedsCleanups = true;
4296     Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result,
4297                                       nullptr, VK_RValue);
4298   }
4299
4300   return Result;
4301 }
4302
4303 ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
4304                                       SourceLocation LParenLoc,
4305                                       ObjCBridgeCastKind Kind,
4306                                       SourceLocation BridgeKeywordLoc,
4307                                       ParsedType Type,
4308                                       SourceLocation RParenLoc,
4309                                       Expr *SubExpr) {
4310   TypeSourceInfo *TSInfo = nullptr;
4311   QualType T = GetTypeFromParser(Type, &TSInfo);
4312   if (Kind == OBC_Bridge)
4313     CheckTollFreeBridgeCast(T, SubExpr);
4314   if (!TSInfo)
4315     TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
4316   return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo,
4317                               SubExpr);
4318 }