SemaExprCXX.cpp revision 76458501a8963fa11b91c9337a487de6871169b4
1//===--- SemaExprCXX.cpp - Semantic Analysis for 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 C++ expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "SemaInherit.h" 15#include "Sema.h" 16#include "clang/AST/ExprCXX.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/Parse/DeclSpec.h" 19#include "clang/Lex/Preprocessor.h" 20#include "clang/Basic/TargetInfo.h" 21#include "llvm/ADT/STLExtras.h" 22using namespace clang; 23 24/// ActOnCXXConversionFunctionExpr - Parse a C++ conversion function 25/// name (e.g., operator void const *) as an expression. This is 26/// very similar to ActOnIdentifierExpr, except that instead of 27/// providing an identifier the parser provides the type of the 28/// conversion function. 29Sema::OwningExprResult 30Sema::ActOnCXXConversionFunctionExpr(Scope *S, SourceLocation OperatorLoc, 31 TypeTy *Ty, bool HasTrailingLParen, 32 const CXXScopeSpec &SS, 33 bool isAddressOfOperand) { 34 QualType ConvType = QualType::getFromOpaquePtr(Ty); 35 QualType ConvTypeCanon = Context.getCanonicalType(ConvType); 36 DeclarationName ConvName 37 = Context.DeclarationNames.getCXXConversionFunctionName(ConvTypeCanon); 38 return ActOnDeclarationNameExpr(S, OperatorLoc, ConvName, HasTrailingLParen, 39 &SS, isAddressOfOperand); 40} 41 42/// ActOnCXXOperatorFunctionIdExpr - Parse a C++ overloaded operator 43/// name (e.g., @c operator+ ) as an expression. This is very 44/// similar to ActOnIdentifierExpr, except that instead of providing 45/// an identifier the parser provides the kind of overloaded 46/// operator that was parsed. 47Sema::OwningExprResult 48Sema::ActOnCXXOperatorFunctionIdExpr(Scope *S, SourceLocation OperatorLoc, 49 OverloadedOperatorKind Op, 50 bool HasTrailingLParen, 51 const CXXScopeSpec &SS, 52 bool isAddressOfOperand) { 53 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(Op); 54 return ActOnDeclarationNameExpr(S, OperatorLoc, Name, HasTrailingLParen, &SS, 55 isAddressOfOperand); 56} 57 58/// ActOnCXXTypeidOfType - Parse typeid( type-id ). 59Action::OwningExprResult 60Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 61 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 62 NamespaceDecl *StdNs = GetStdNamespace(); 63 if (!StdNs) 64 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 65 66 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 67 Decl *TypeInfoDecl = LookupQualifiedName(StdNs, TypeInfoII, LookupTagName); 68 RecordDecl *TypeInfoRecordDecl = dyn_cast_or_null<RecordDecl>(TypeInfoDecl); 69 if (!TypeInfoRecordDecl) 70 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 71 72 QualType TypeInfoType = Context.getTypeDeclType(TypeInfoRecordDecl); 73 74 return Owned(new (Context) CXXTypeidExpr(isType, TyOrExpr, 75 TypeInfoType.withConst(), 76 SourceRange(OpLoc, RParenLoc))); 77} 78 79/// ActOnCXXBoolLiteral - Parse {true,false} literals. 80Action::OwningExprResult 81Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 82 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 83 "Unknown C++ Boolean value!"); 84 return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true, 85 Context.BoolTy, OpLoc)); 86} 87 88/// ActOnCXXThrow - Parse throw expressions. 89Action::OwningExprResult 90Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprArg E) { 91 return Owned(new (Context) CXXThrowExpr((Expr*)E.release(), Context.VoidTy, 92 OpLoc)); 93} 94 95Action::OwningExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) { 96 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 97 /// is a non-lvalue expression whose value is the address of the object for 98 /// which the function is called. 99 100 if (!isa<FunctionDecl>(CurContext)) 101 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use)); 102 103 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) 104 if (MD->isInstance()) 105 return Owned(new (Context) CXXThisExpr(ThisLoc, 106 MD->getThisType(Context))); 107 108 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use)); 109} 110 111/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 112/// Can be interpreted either as function-style casting ("int(x)") 113/// or class type construction ("ClassType(x,y,z)") 114/// or creation of a value-initialized type ("int()"). 115Action::OwningExprResult 116Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep, 117 SourceLocation LParenLoc, 118 MultiExprArg exprs, 119 SourceLocation *CommaLocs, 120 SourceLocation RParenLoc) { 121 assert(TypeRep && "Missing type!"); 122 QualType Ty = QualType::getFromOpaquePtr(TypeRep); 123 unsigned NumExprs = exprs.size(); 124 Expr **Exprs = (Expr**)exprs.get(); 125 SourceLocation TyBeginLoc = TypeRange.getBegin(); 126 SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc); 127 128 if (Ty->isDependentType() || 129 CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) { 130 exprs.release(); 131 return Owned(new (Context) CXXTemporaryObjectExpr(0, Ty, TyBeginLoc, 132 Exprs, NumExprs, 133 RParenLoc)); 134 } 135 136 137 // C++ [expr.type.conv]p1: 138 // If the expression list is a single expression, the type conversion 139 // expression is equivalent (in definedness, and if defined in meaning) to the 140 // corresponding cast expression. 141 // 142 if (NumExprs == 1) { 143 if (CheckCastTypes(TypeRange, Ty, Exprs[0])) 144 return ExprError(); 145 exprs.release(); 146 return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(), 147 Ty, TyBeginLoc, Exprs[0], 148 RParenLoc)); 149 } 150 151 if (const RecordType *RT = Ty->getAsRecordType()) { 152 CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl()); 153 154 if (NumExprs > 1 || Record->hasUserDeclaredConstructor()) { 155 CXXConstructorDecl *Constructor 156 = PerformInitializationByConstructor(Ty, Exprs, NumExprs, 157 TypeRange.getBegin(), 158 SourceRange(TypeRange.getBegin(), 159 RParenLoc), 160 DeclarationName(), 161 IK_Direct); 162 163 if (!Constructor) 164 return ExprError(); 165 166 exprs.release(); 167 return Owned(new (Context) CXXTemporaryObjectExpr(Constructor, Ty, 168 TyBeginLoc, Exprs, 169 NumExprs, RParenLoc)); 170 } 171 172 // Fall through to value-initialize an object of class type that 173 // doesn't have a user-declared default constructor. 174 } 175 176 // C++ [expr.type.conv]p1: 177 // If the expression list specifies more than a single value, the type shall 178 // be a class with a suitably declared constructor. 179 // 180 if (NumExprs > 1) 181 return ExprError(Diag(CommaLocs[0], 182 diag::err_builtin_func_cast_more_than_one_arg) 183 << FullRange); 184 185 assert(NumExprs == 0 && "Expected 0 expressions"); 186 187 // C++ [expr.type.conv]p2: 188 // The expression T(), where T is a simple-type-specifier for a non-array 189 // complete object type or the (possibly cv-qualified) void type, creates an 190 // rvalue of the specified type, which is value-initialized. 191 // 192 if (Ty->isArrayType()) 193 return ExprError(Diag(TyBeginLoc, 194 diag::err_value_init_for_array_type) << FullRange); 195 if (!Ty->isDependentType() && !Ty->isVoidType() && 196 RequireCompleteType(TyBeginLoc, Ty, 197 diag::err_invalid_incomplete_type_use, FullRange)) 198 return ExprError(); 199 200 if (RequireNonAbstractType(TyBeginLoc, Ty, 201 diag::err_allocation_of_abstract_type)) 202 return ExprError(); 203 204 exprs.release(); 205 return Owned(new (Context) CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc)); 206} 207 208 209/// ActOnCXXNew - Parsed a C++ 'new' expression (C++ 5.3.4), as in e.g.: 210/// @code new (memory) int[size][4] @endcode 211/// or 212/// @code ::new Foo(23, "hello") @endcode 213/// For the interpretation of this heap of arguments, consult the base version. 214Action::OwningExprResult 215Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 216 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 217 SourceLocation PlacementRParen, bool ParenTypeId, 218 Declarator &D, SourceLocation ConstructorLParen, 219 MultiExprArg ConstructorArgs, 220 SourceLocation ConstructorRParen) 221{ 222 Expr *ArraySize = 0; 223 unsigned Skip = 0; 224 // If the specified type is an array, unwrap it and save the expression. 225 if (D.getNumTypeObjects() > 0 && 226 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 227 DeclaratorChunk &Chunk = D.getTypeObject(0); 228 if (Chunk.Arr.hasStatic) 229 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 230 << D.getSourceRange()); 231 if (!Chunk.Arr.NumElts) 232 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 233 << D.getSourceRange()); 234 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 235 Skip = 1; 236 } 237 238 QualType AllocType = GetTypeForDeclarator(D, /*Scope=*/0, Skip); 239 if (D.getInvalidType()) 240 return ExprError(); 241 242 if (CheckAllocatedType(AllocType, D)) 243 return ExprError(); 244 245 QualType ResultType = AllocType->isDependentType() 246 ? Context.DependentTy 247 : Context.getPointerType(AllocType); 248 249 // That every array dimension except the first is constant was already 250 // checked by the type check above. 251 252 // C++ 5.3.4p6: "The expression in a direct-new-declarator shall have integral 253 // or enumeration type with a non-negative value." 254 if (ArraySize && !ArraySize->isTypeDependent()) { 255 QualType SizeType = ArraySize->getType(); 256 if (!SizeType->isIntegralType() && !SizeType->isEnumeralType()) 257 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 258 diag::err_array_size_not_integral) 259 << SizeType << ArraySize->getSourceRange()); 260 // Let's see if this is a constant < 0. If so, we reject it out of hand. 261 // We don't care about special rules, so we tell the machinery it's not 262 // evaluated - it gives us a result in more cases. 263 if (!ArraySize->isValueDependent()) { 264 llvm::APSInt Value; 265 if (ArraySize->isIntegerConstantExpr(Value, Context, 0, false)) { 266 if (Value < llvm::APSInt( 267 llvm::APInt::getNullValue(Value.getBitWidth()), false)) 268 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 269 diag::err_typecheck_negative_array_size) 270 << ArraySize->getSourceRange()); 271 } 272 } 273 } 274 275 FunctionDecl *OperatorNew = 0; 276 FunctionDecl *OperatorDelete = 0; 277 Expr **PlaceArgs = (Expr**)PlacementArgs.get(); 278 unsigned NumPlaceArgs = PlacementArgs.size(); 279 if (!AllocType->isDependentType() && 280 !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) && 281 FindAllocationFunctions(StartLoc, 282 SourceRange(PlacementLParen, PlacementRParen), 283 UseGlobal, AllocType, ArraySize, PlaceArgs, 284 NumPlaceArgs, OperatorNew, OperatorDelete)) 285 return ExprError(); 286 287 bool Init = ConstructorLParen.isValid(); 288 // --- Choosing a constructor --- 289 // C++ 5.3.4p15 290 // 1) If T is a POD and there's no initializer (ConstructorLParen is invalid) 291 // the object is not initialized. If the object, or any part of it, is 292 // const-qualified, it's an error. 293 // 2) If T is a POD and there's an empty initializer, the object is value- 294 // initialized. 295 // 3) If T is a POD and there's one initializer argument, the object is copy- 296 // constructed. 297 // 4) If T is a POD and there's more initializer arguments, it's an error. 298 // 5) If T is not a POD, the initializer arguments are used as constructor 299 // arguments. 300 // 301 // Or by the C++0x formulation: 302 // 1) If there's no initializer, the object is default-initialized according 303 // to C++0x rules. 304 // 2) Otherwise, the object is direct-initialized. 305 CXXConstructorDecl *Constructor = 0; 306 Expr **ConsArgs = (Expr**)ConstructorArgs.get(); 307 unsigned NumConsArgs = ConstructorArgs.size(); 308 if (AllocType->isDependentType()) { 309 // Skip all the checks. 310 } 311 // FIXME: Should check for primitive/aggregate here, not record. 312 else if (const RecordType *RT = AllocType->getAsRecordType()) { 313 // FIXME: This is incorrect for when there is an empty initializer and 314 // no user-defined constructor. Must zero-initialize, not default-construct. 315 Constructor = PerformInitializationByConstructor( 316 AllocType, ConsArgs, NumConsArgs, 317 D.getSourceRange().getBegin(), 318 SourceRange(D.getSourceRange().getBegin(), 319 ConstructorRParen), 320 RT->getDecl()->getDeclName(), 321 NumConsArgs != 0 ? IK_Direct : IK_Default); 322 if (!Constructor) 323 return ExprError(); 324 } else { 325 if (!Init) { 326 // FIXME: Check that no subpart is const. 327 if (AllocType.isConstQualified()) 328 return ExprError(Diag(StartLoc, diag::err_new_uninitialized_const) 329 << D.getSourceRange()); 330 } else if (NumConsArgs == 0) { 331 // Object is value-initialized. Do nothing. 332 } else if (NumConsArgs == 1) { 333 // Object is direct-initialized. 334 // FIXME: WHAT DeclarationName do we pass in here? 335 if (CheckInitializerTypes(ConsArgs[0], AllocType, StartLoc, 336 DeclarationName() /*AllocType.getAsString()*/, 337 /*DirectInit=*/true)) 338 return ExprError(); 339 } else { 340 return ExprError(Diag(StartLoc, 341 diag::err_builtin_direct_init_more_than_one_arg) 342 << SourceRange(ConstructorLParen, ConstructorRParen)); 343 } 344 } 345 346 // FIXME: Also check that the destructor is accessible. (C++ 5.3.4p16) 347 348 PlacementArgs.release(); 349 ConstructorArgs.release(); 350 return Owned(new (Context) CXXNewExpr(UseGlobal, OperatorNew, PlaceArgs, 351 NumPlaceArgs, ParenTypeId, ArraySize, Constructor, Init, 352 ConsArgs, NumConsArgs, OperatorDelete, ResultType, 353 StartLoc, Init ? ConstructorRParen : SourceLocation())); 354} 355 356/// CheckAllocatedType - Checks that a type is suitable as the allocated type 357/// in a new-expression. 358/// dimension off and stores the size expression in ArraySize. 359bool Sema::CheckAllocatedType(QualType AllocType, const Declarator &D) 360{ 361 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 362 // abstract class type or array thereof. 363 if (AllocType->isFunctionType()) 364 return Diag(D.getSourceRange().getBegin(), diag::err_bad_new_type) 365 << AllocType << 0 << D.getSourceRange(); 366 else if (AllocType->isReferenceType()) 367 return Diag(D.getSourceRange().getBegin(), diag::err_bad_new_type) 368 << AllocType << 1 << D.getSourceRange(); 369 else if (!AllocType->isDependentType() && 370 RequireCompleteType(D.getSourceRange().getBegin(), AllocType, 371 diag::err_new_incomplete_type, 372 D.getSourceRange())) 373 return true; 374 else if (RequireNonAbstractType(D.getSourceRange().getBegin(), AllocType, 375 diag::err_allocation_of_abstract_type)) 376 return true; 377 378 // Every dimension shall be of constant size. 379 unsigned i = 1; 380 while (const ArrayType *Array = Context.getAsArrayType(AllocType)) { 381 if (!Array->isConstantArrayType()) { 382 Diag(D.getTypeObject(i).Loc, diag::err_new_array_nonconst) 383 << static_cast<Expr*>(D.getTypeObject(i).Arr.NumElts)->getSourceRange(); 384 return true; 385 } 386 AllocType = Array->getElementType(); 387 ++i; 388 } 389 390 return false; 391} 392 393/// FindAllocationFunctions - Finds the overloads of operator new and delete 394/// that are appropriate for the allocation. 395bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 396 bool UseGlobal, QualType AllocType, 397 bool IsArray, Expr **PlaceArgs, 398 unsigned NumPlaceArgs, 399 FunctionDecl *&OperatorNew, 400 FunctionDecl *&OperatorDelete) 401{ 402 // --- Choosing an allocation function --- 403 // C++ 5.3.4p8 - 14 & 18 404 // 1) If UseGlobal is true, only look in the global scope. Else, also look 405 // in the scope of the allocated class. 406 // 2) If an array size is given, look for operator new[], else look for 407 // operator new. 408 // 3) The first argument is always size_t. Append the arguments from the 409 // placement form. 410 // FIXME: Also find the appropriate delete operator. 411 412 llvm::SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs); 413 // We don't care about the actual value of this argument. 414 // FIXME: Should the Sema create the expression and embed it in the syntax 415 // tree? Or should the consumer just recalculate the value? 416 AllocArgs[0] = new (Context) IntegerLiteral(llvm::APInt::getNullValue( 417 Context.Target.getPointerWidth(0)), 418 Context.getSizeType(), 419 SourceLocation()); 420 std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1); 421 422 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 423 IsArray ? OO_Array_New : OO_New); 424 if (AllocType->isRecordType() && !UseGlobal) { 425 CXXRecordDecl *Record 426 = cast<CXXRecordDecl>(AllocType->getAsRecordType()->getDecl()); 427 // FIXME: We fail to find inherited overloads. 428 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 429 AllocArgs.size(), Record, /*AllowMissing=*/true, 430 OperatorNew)) 431 return true; 432 } 433 if (!OperatorNew) { 434 // Didn't find a member overload. Look for a global one. 435 DeclareGlobalNewDelete(); 436 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 437 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 438 AllocArgs.size(), TUDecl, /*AllowMissing=*/false, 439 OperatorNew)) 440 return true; 441 } 442 443 // FIXME: This is leaked on error. But so much is currently in Sema that it's 444 // easier to clean it in one go. 445 AllocArgs[0]->Destroy(Context); 446 return false; 447} 448 449/// FindAllocationOverload - Find an fitting overload for the allocation 450/// function in the specified scope. 451bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 452 DeclarationName Name, Expr** Args, 453 unsigned NumArgs, DeclContext *Ctx, 454 bool AllowMissing, FunctionDecl *&Operator) 455{ 456 DeclContext::lookup_iterator Alloc, AllocEnd; 457 llvm::tie(Alloc, AllocEnd) = Ctx->lookup(Context, Name); 458 if (Alloc == AllocEnd) { 459 if (AllowMissing) 460 return false; 461 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 462 << Name << Range; 463 } 464 465 OverloadCandidateSet Candidates; 466 for (; Alloc != AllocEnd; ++Alloc) { 467 // Even member operator new/delete are implicitly treated as 468 // static, so don't use AddMemberCandidate. 469 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*Alloc)) 470 AddOverloadCandidate(Fn, Args, NumArgs, Candidates, 471 /*SuppressUserConversions=*/false); 472 } 473 474 // Do the resolution. 475 OverloadCandidateSet::iterator Best; 476 switch(BestViableFunction(Candidates, Best)) { 477 case OR_Success: { 478 // Got one! 479 FunctionDecl *FnDecl = Best->Function; 480 // The first argument is size_t, and the first parameter must be size_t, 481 // too. This is checked on declaration and can be assumed. (It can't be 482 // asserted on, though, since invalid decls are left in there.) 483 for (unsigned i = 1; i < NumArgs; ++i) { 484 // FIXME: Passing word to diagnostic. 485 if (PerformCopyInitialization(Args[i-1], 486 FnDecl->getParamDecl(i)->getType(), 487 "passing")) 488 return true; 489 } 490 Operator = FnDecl; 491 return false; 492 } 493 494 case OR_No_Viable_Function: 495 if (AllowMissing) 496 return false; 497 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 498 << Name << Range; 499 PrintOverloadCandidates(Candidates, /*OnlyViable=*/false); 500 return true; 501 502 case OR_Ambiguous: 503 Diag(StartLoc, diag::err_ovl_ambiguous_call) 504 << Name << Range; 505 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true); 506 return true; 507 508 case OR_Deleted: 509 Diag(StartLoc, diag::err_ovl_deleted_call) 510 << Best->Function->isDeleted() 511 << Name << Range; 512 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true); 513 return true; 514 } 515 assert(false && "Unreachable, bad result from BestViableFunction"); 516 return true; 517} 518 519 520/// DeclareGlobalNewDelete - Declare the global forms of operator new and 521/// delete. These are: 522/// @code 523/// void* operator new(std::size_t) throw(std::bad_alloc); 524/// void* operator new[](std::size_t) throw(std::bad_alloc); 525/// void operator delete(void *) throw(); 526/// void operator delete[](void *) throw(); 527/// @endcode 528/// Note that the placement and nothrow forms of new are *not* implicitly 529/// declared. Their use requires including \<new\>. 530void Sema::DeclareGlobalNewDelete() 531{ 532 if (GlobalNewDeleteDeclared) 533 return; 534 GlobalNewDeleteDeclared = true; 535 536 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 537 QualType SizeT = Context.getSizeType(); 538 539 // FIXME: Exception specifications are not added. 540 DeclareGlobalAllocationFunction( 541 Context.DeclarationNames.getCXXOperatorName(OO_New), 542 VoidPtr, SizeT); 543 DeclareGlobalAllocationFunction( 544 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 545 VoidPtr, SizeT); 546 DeclareGlobalAllocationFunction( 547 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 548 Context.VoidTy, VoidPtr); 549 DeclareGlobalAllocationFunction( 550 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 551 Context.VoidTy, VoidPtr); 552} 553 554/// DeclareGlobalAllocationFunction - Declares a single implicit global 555/// allocation function if it doesn't already exist. 556void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 557 QualType Return, QualType Argument) 558{ 559 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 560 561 // Check if this function is already declared. 562 { 563 DeclContext::lookup_iterator Alloc, AllocEnd; 564 for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Context, Name); 565 Alloc != AllocEnd; ++Alloc) { 566 // FIXME: Do we need to check for default arguments here? 567 FunctionDecl *Func = cast<FunctionDecl>(*Alloc); 568 if (Func->getNumParams() == 1 && 569 Context.getCanonicalType(Func->getParamDecl(0)->getType())==Argument) 570 return; 571 } 572 } 573 574 QualType FnType = Context.getFunctionType(Return, &Argument, 1, false, 0); 575 FunctionDecl *Alloc = 576 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name, 577 FnType, FunctionDecl::None, false, true, 578 SourceLocation()); 579 Alloc->setImplicit(); 580 ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 581 0, Argument, VarDecl::None, 0); 582 Alloc->setParams(Context, &Param, 1); 583 584 // FIXME: Also add this declaration to the IdentifierResolver, but 585 // make sure it is at the end of the chain to coincide with the 586 // global scope. 587 ((DeclContext *)TUScope->getEntity())->addDecl(Context, Alloc); 588} 589 590/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 591/// @code ::delete ptr; @endcode 592/// or 593/// @code delete [] ptr; @endcode 594Action::OwningExprResult 595Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 596 bool ArrayForm, ExprArg Operand) 597{ 598 // C++ 5.3.5p1: "The operand shall have a pointer type, or a class type 599 // having a single conversion function to a pointer type. The result has 600 // type void." 601 // DR599 amends "pointer type" to "pointer to object type" in both cases. 602 603 Expr *Ex = (Expr *)Operand.get(); 604 if (!Ex->isTypeDependent()) { 605 QualType Type = Ex->getType(); 606 607 if (Type->isRecordType()) { 608 // FIXME: Find that one conversion function and amend the type. 609 } 610 611 if (!Type->isPointerType()) 612 return ExprError(Diag(StartLoc, diag::err_delete_operand) 613 << Type << Ex->getSourceRange()); 614 615 QualType Pointee = Type->getAsPointerType()->getPointeeType(); 616 if (Pointee->isFunctionType() || Pointee->isVoidType()) 617 return ExprError(Diag(StartLoc, diag::err_delete_operand) 618 << Type << Ex->getSourceRange()); 619 else if (!Pointee->isDependentType() && 620 RequireCompleteType(StartLoc, Pointee, 621 diag::warn_delete_incomplete, 622 Ex->getSourceRange())) 623 return ExprError(); 624 625 // FIXME: Look up the correct operator delete overload and pass a pointer 626 // along. 627 // FIXME: Check access and ambiguity of operator delete and destructor. 628 } 629 630 Operand.release(); 631 return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm, 632 0, Ex, StartLoc)); 633} 634 635 636/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a 637/// C++ if/switch/while/for statement. 638/// e.g: "if (int x = f()) {...}" 639Action::OwningExprResult 640Sema::ActOnCXXConditionDeclarationExpr(Scope *S, SourceLocation StartLoc, 641 Declarator &D, 642 SourceLocation EqualLoc, 643 ExprArg AssignExprVal) { 644 assert(AssignExprVal.get() && "Null assignment expression"); 645 646 // C++ 6.4p2: 647 // The declarator shall not specify a function or an array. 648 // The type-specifier-seq shall not contain typedef and shall not declare a 649 // new class or enumeration. 650 651 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && 652 "Parser allowed 'typedef' as storage class of condition decl."); 653 654 QualType Ty = GetTypeForDeclarator(D, S); 655 656 if (Ty->isFunctionType()) { // The declarator shall not specify a function... 657 // We exit without creating a CXXConditionDeclExpr because a FunctionDecl 658 // would be created and CXXConditionDeclExpr wants a VarDecl. 659 return ExprError(Diag(StartLoc, diag::err_invalid_use_of_function_type) 660 << SourceRange(StartLoc, EqualLoc)); 661 } else if (Ty->isArrayType()) { // ...or an array. 662 Diag(StartLoc, diag::err_invalid_use_of_array_type) 663 << SourceRange(StartLoc, EqualLoc); 664 } else if (const RecordType *RT = Ty->getAsRecordType()) { 665 RecordDecl *RD = RT->getDecl(); 666 // The type-specifier-seq shall not declare a new class... 667 if (RD->isDefinition() && 668 (RD->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(RD)))) 669 Diag(RD->getLocation(), diag::err_type_defined_in_condition); 670 } else if (const EnumType *ET = Ty->getAsEnumType()) { 671 EnumDecl *ED = ET->getDecl(); 672 // ...or enumeration. 673 if (ED->isDefinition() && 674 (ED->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(ED)))) 675 Diag(ED->getLocation(), diag::err_type_defined_in_condition); 676 } 677 678 DeclPtrTy Dcl = ActOnDeclarator(S, D, DeclPtrTy()); 679 if (!Dcl) 680 return ExprError(); 681 AddInitializerToDecl(Dcl, move(AssignExprVal)); 682 683 // Mark this variable as one that is declared within a conditional. 684 // We know that the decl had to be a VarDecl because that is the only type of 685 // decl that can be assigned and the grammar requires an '='. 686 VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>()); 687 VD->setDeclaredInCondition(true); 688 return Owned(new (Context) CXXConditionDeclExpr(StartLoc, EqualLoc, VD)); 689} 690 691/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 692bool Sema::CheckCXXBooleanCondition(Expr *&CondExpr) { 693 // C++ 6.4p4: 694 // The value of a condition that is an initialized declaration in a statement 695 // other than a switch statement is the value of the declared variable 696 // implicitly converted to type bool. If that conversion is ill-formed, the 697 // program is ill-formed. 698 // The value of a condition that is an expression is the value of the 699 // expression, implicitly converted to bool. 700 // 701 return PerformContextuallyConvertToBool(CondExpr); 702} 703 704/// Helper function to determine whether this is the (deprecated) C++ 705/// conversion from a string literal to a pointer to non-const char or 706/// non-const wchar_t (for narrow and wide string literals, 707/// respectively). 708bool 709Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 710 // Look inside the implicit cast, if it exists. 711 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 712 From = Cast->getSubExpr(); 713 714 // A string literal (2.13.4) that is not a wide string literal can 715 // be converted to an rvalue of type "pointer to char"; a wide 716 // string literal can be converted to an rvalue of type "pointer 717 // to wchar_t" (C++ 4.2p2). 718 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From)) 719 if (const PointerType *ToPtrType = ToType->getAsPointerType()) 720 if (const BuiltinType *ToPointeeType 721 = ToPtrType->getPointeeType()->getAsBuiltinType()) { 722 // This conversion is considered only when there is an 723 // explicit appropriate pointer target type (C++ 4.2p2). 724 if (ToPtrType->getPointeeType().getCVRQualifiers() == 0 && 725 ((StrLit->isWide() && ToPointeeType->isWideCharType()) || 726 (!StrLit->isWide() && 727 (ToPointeeType->getKind() == BuiltinType::Char_U || 728 ToPointeeType->getKind() == BuiltinType::Char_S)))) 729 return true; 730 } 731 732 return false; 733} 734 735/// PerformImplicitConversion - Perform an implicit conversion of the 736/// expression From to the type ToType. Returns true if there was an 737/// error, false otherwise. The expression From is replaced with the 738/// converted expression. Flavor is the kind of conversion we're 739/// performing, used in the error message. If @p AllowExplicit, 740/// explicit user-defined conversions are permitted. @p Elidable should be true 741/// when called for copies which may be elided (C++ 12.8p15). C++0x overload 742/// resolution works differently in that case. 743bool 744Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 745 const char *Flavor, bool AllowExplicit, 746 bool Elidable) 747{ 748 ImplicitConversionSequence ICS; 749 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 750 if (Elidable && getLangOptions().CPlusPlus0x) { 751 ICS = TryImplicitConversion(From, ToType, /*SuppressUserConversions*/false, 752 AllowExplicit, /*ForceRValue*/true); 753 } 754 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) { 755 ICS = TryImplicitConversion(From, ToType, false, AllowExplicit); 756 } 757 return PerformImplicitConversion(From, ToType, ICS, Flavor); 758} 759 760/// PerformImplicitConversion - Perform an implicit conversion of the 761/// expression From to the type ToType using the pre-computed implicit 762/// conversion sequence ICS. Returns true if there was an error, false 763/// otherwise. The expression From is replaced with the converted 764/// expression. Flavor is the kind of conversion we're performing, 765/// used in the error message. 766bool 767Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 768 const ImplicitConversionSequence &ICS, 769 const char* Flavor) { 770 switch (ICS.ConversionKind) { 771 case ImplicitConversionSequence::StandardConversion: 772 if (PerformImplicitConversion(From, ToType, ICS.Standard, Flavor)) 773 return true; 774 break; 775 776 case ImplicitConversionSequence::UserDefinedConversion: 777 // FIXME: This is, of course, wrong. We'll need to actually call 778 // the constructor or conversion operator, and then cope with the 779 // standard conversions. 780 ImpCastExprToType(From, ToType.getNonReferenceType(), 781 ToType->isLValueReferenceType()); 782 return false; 783 784 case ImplicitConversionSequence::EllipsisConversion: 785 assert(false && "Cannot perform an ellipsis conversion"); 786 return false; 787 788 case ImplicitConversionSequence::BadConversion: 789 return true; 790 } 791 792 // Everything went well. 793 return false; 794} 795 796/// PerformImplicitConversion - Perform an implicit conversion of the 797/// expression From to the type ToType by following the standard 798/// conversion sequence SCS. Returns true if there was an error, false 799/// otherwise. The expression From is replaced with the converted 800/// expression. Flavor is the context in which we're performing this 801/// conversion, for use in error messages. 802bool 803Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 804 const StandardConversionSequence& SCS, 805 const char *Flavor) { 806 // Overall FIXME: we are recomputing too many types here and doing 807 // far too much extra work. What this means is that we need to keep 808 // track of more information that is computed when we try the 809 // implicit conversion initially, so that we don't need to recompute 810 // anything here. 811 QualType FromType = From->getType(); 812 813 if (SCS.CopyConstructor) { 814 // FIXME: Create a temporary object by calling the copy 815 // constructor. 816 ImpCastExprToType(From, ToType.getNonReferenceType(), 817 ToType->isLValueReferenceType()); 818 return false; 819 } 820 821 // Perform the first implicit conversion. 822 switch (SCS.First) { 823 case ICK_Identity: 824 case ICK_Lvalue_To_Rvalue: 825 // Nothing to do. 826 break; 827 828 case ICK_Array_To_Pointer: 829 FromType = Context.getArrayDecayedType(FromType); 830 ImpCastExprToType(From, FromType); 831 break; 832 833 case ICK_Function_To_Pointer: 834 if (Context.getCanonicalType(FromType) == Context.OverloadTy) { 835 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true); 836 if (!Fn) 837 return true; 838 839 if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin())) 840 return true; 841 842 FixOverloadedFunctionReference(From, Fn); 843 FromType = From->getType(); 844 } 845 FromType = Context.getPointerType(FromType); 846 ImpCastExprToType(From, FromType); 847 break; 848 849 default: 850 assert(false && "Improper first standard conversion"); 851 break; 852 } 853 854 // Perform the second implicit conversion 855 switch (SCS.Second) { 856 case ICK_Identity: 857 // Nothing to do. 858 break; 859 860 case ICK_Integral_Promotion: 861 case ICK_Floating_Promotion: 862 case ICK_Complex_Promotion: 863 case ICK_Integral_Conversion: 864 case ICK_Floating_Conversion: 865 case ICK_Complex_Conversion: 866 case ICK_Floating_Integral: 867 case ICK_Complex_Real: 868 case ICK_Compatible_Conversion: 869 // FIXME: Go deeper to get the unqualified type! 870 FromType = ToType.getUnqualifiedType(); 871 ImpCastExprToType(From, FromType); 872 break; 873 874 case ICK_Pointer_Conversion: 875 if (SCS.IncompatibleObjC) { 876 // Diagnose incompatible Objective-C conversions 877 Diag(From->getSourceRange().getBegin(), 878 diag::ext_typecheck_convert_incompatible_pointer) 879 << From->getType() << ToType << Flavor 880 << From->getSourceRange(); 881 } 882 883 if (CheckPointerConversion(From, ToType)) 884 return true; 885 ImpCastExprToType(From, ToType); 886 break; 887 888 case ICK_Pointer_Member: 889 if (CheckMemberPointerConversion(From, ToType)) 890 return true; 891 ImpCastExprToType(From, ToType); 892 break; 893 894 case ICK_Boolean_Conversion: 895 FromType = Context.BoolTy; 896 ImpCastExprToType(From, FromType); 897 break; 898 899 default: 900 assert(false && "Improper second standard conversion"); 901 break; 902 } 903 904 switch (SCS.Third) { 905 case ICK_Identity: 906 // Nothing to do. 907 break; 908 909 case ICK_Qualification: 910 // FIXME: Not sure about lvalue vs rvalue here in the presence of 911 // rvalue references. 912 ImpCastExprToType(From, ToType.getNonReferenceType(), 913 ToType->isLValueReferenceType()); 914 break; 915 916 default: 917 assert(false && "Improper second standard conversion"); 918 break; 919 } 920 921 return false; 922} 923 924Sema::OwningExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait OTT, 925 SourceLocation KWLoc, 926 SourceLocation LParen, 927 TypeTy *Ty, 928 SourceLocation RParen) { 929 // FIXME: Some of the type traits have requirements. Interestingly, only the 930 // __is_base_of requirement is explicitly stated to be diagnosed. Indeed, 931 // G++ accepts __is_pod(Incomplete) without complaints, and claims that the 932 // type is indeed a POD. 933 934 // There is no point in eagerly computing the value. The traits are designed 935 // to be used from type trait templates, so Ty will be a template parameter 936 // 99% of the time. 937 return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, OTT, 938 QualType::getFromOpaquePtr(Ty), 939 RParen, Context.BoolTy)); 940} 941 942QualType Sema::CheckPointerToMemberOperands( 943 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isIndirect) 944{ 945 const char *OpSpelling = isIndirect ? "->*" : ".*"; 946 // C++ 5.5p2 947 // The binary operator .* [p3: ->*] binds its second operand, which shall 948 // be of type "pointer to member of T" (where T is a completely-defined 949 // class type) [...] 950 QualType RType = rex->getType(); 951 const MemberPointerType *MemPtr = RType->getAsMemberPointerType(); 952 if (!MemPtr) { 953 Diag(Loc, diag::err_bad_memptr_rhs) 954 << OpSpelling << RType << rex->getSourceRange(); 955 return QualType(); 956 } else if (RequireCompleteType(Loc, QualType(MemPtr->getClass(), 0), 957 diag::err_memptr_rhs_incomplete, 958 rex->getSourceRange())) 959 return QualType(); 960 961 QualType Class(MemPtr->getClass(), 0); 962 963 // C++ 5.5p2 964 // [...] to its first operand, which shall be of class T or of a class of 965 // which T is an unambiguous and accessible base class. [p3: a pointer to 966 // such a class] 967 QualType LType = lex->getType(); 968 if (isIndirect) { 969 if (const PointerType *Ptr = LType->getAsPointerType()) 970 LType = Ptr->getPointeeType().getNonReferenceType(); 971 else { 972 Diag(Loc, diag::err_bad_memptr_lhs) 973 << OpSpelling << 1 << LType << lex->getSourceRange(); 974 return QualType(); 975 } 976 } 977 978 if (Context.getCanonicalType(Class).getUnqualifiedType() != 979 Context.getCanonicalType(LType).getUnqualifiedType()) { 980 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 981 /*DetectVirtual=*/false); 982 // FIXME: Would it be useful to print full ambiguity paths, 983 // or is that overkill? 984 if (!IsDerivedFrom(LType, Class, Paths) || 985 Paths.isAmbiguous(Context.getCanonicalType(Class))) { 986 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 987 << (int)isIndirect << lex->getType() << lex->getSourceRange(); 988 return QualType(); 989 } 990 } 991 992 // C++ 5.5p2 993 // The result is an object or a function of the type specified by the 994 // second operand. 995 // The cv qualifiers are the union of those in the pointer and the left side, 996 // in accordance with 5.5p5 and 5.2.5. 997 // FIXME: This returns a dereferenced member function pointer as a normal 998 // function type. However, the only operation valid on such functions is 999 // calling them. There's also a GCC extension to get a function pointer to 1000 // the thing, which is another complication, because this type - unlike the 1001 // type that is the result of this expression - takes the class as the first 1002 // argument. 1003 // We probably need a "MemberFunctionClosureType" or something like that. 1004 QualType Result = MemPtr->getPointeeType(); 1005 if (LType.isConstQualified()) 1006 Result.addConst(); 1007 if (LType.isVolatileQualified()) 1008 Result.addVolatile(); 1009 return Result; 1010} 1011 1012/// \brief Get the target type of a standard or user-defined conversion. 1013static QualType TargetType(const ImplicitConversionSequence &ICS) { 1014 assert((ICS.ConversionKind == 1015 ImplicitConversionSequence::StandardConversion || 1016 ICS.ConversionKind == 1017 ImplicitConversionSequence::UserDefinedConversion) && 1018 "function only valid for standard or user-defined conversions"); 1019 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion) 1020 return QualType::getFromOpaquePtr(ICS.Standard.ToTypePtr); 1021 return QualType::getFromOpaquePtr(ICS.UserDefined.After.ToTypePtr); 1022} 1023 1024/// \brief Try to convert a type to another according to C++0x 5.16p3. 1025/// 1026/// This is part of the parameter validation for the ? operator. If either 1027/// value operand is a class type, the two operands are attempted to be 1028/// converted to each other. This function does the conversion in one direction. 1029/// It emits a diagnostic and returns true only if it finds an ambiguous 1030/// conversion. 1031static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 1032 SourceLocation QuestionLoc, 1033 ImplicitConversionSequence &ICS) 1034{ 1035 // C++0x 5.16p3 1036 // The process for determining whether an operand expression E1 of type T1 1037 // can be converted to match an operand expression E2 of type T2 is defined 1038 // as follows: 1039 // -- If E2 is an lvalue: 1040 if (To->isLvalue(Self.Context) == Expr::LV_Valid) { 1041 // E1 can be converted to match E2 if E1 can be implicitly converted to 1042 // type "lvalue reference to T2", subject to the constraint that in the 1043 // conversion the reference must bind directly to E1. 1044 if (!Self.CheckReferenceInit(From, 1045 Self.Context.getLValueReferenceType(To->getType()), 1046 &ICS)) 1047 { 1048 assert((ICS.ConversionKind == 1049 ImplicitConversionSequence::StandardConversion || 1050 ICS.ConversionKind == 1051 ImplicitConversionSequence::UserDefinedConversion) && 1052 "expected a definite conversion"); 1053 bool DirectBinding = 1054 ICS.ConversionKind == ImplicitConversionSequence::StandardConversion ? 1055 ICS.Standard.DirectBinding : ICS.UserDefined.After.DirectBinding; 1056 if (DirectBinding) 1057 return false; 1058 } 1059 } 1060 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1061 // -- If E2 is an rvalue, or if the conversion above cannot be done: 1062 // -- if E1 and E2 have class type, and the underlying class types are 1063 // the same or one is a base class of the other: 1064 QualType FTy = From->getType(); 1065 QualType TTy = To->getType(); 1066 const RecordType *FRec = FTy->getAsRecordType(); 1067 const RecordType *TRec = TTy->getAsRecordType(); 1068 bool FDerivedFromT = FRec && TRec && Self.IsDerivedFrom(FTy, TTy); 1069 if (FRec && TRec && (FRec == TRec || 1070 FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 1071 // E1 can be converted to match E2 if the class of T2 is the 1072 // same type as, or a base class of, the class of T1, and 1073 // [cv2 > cv1]. 1074 if ((FRec == TRec || FDerivedFromT) && TTy.isAtLeastAsQualifiedAs(FTy)) { 1075 // Could still fail if there's no copy constructor. 1076 // FIXME: Is this a hard error then, or just a conversion failure? The 1077 // standard doesn't say. 1078 ICS = Self.TryCopyInitialization(From, TTy); 1079 } 1080 } else { 1081 // -- Otherwise: E1 can be converted to match E2 if E1 can be 1082 // implicitly converted to the type that expression E2 would have 1083 // if E2 were converted to an rvalue. 1084 // First find the decayed type. 1085 if (TTy->isFunctionType()) 1086 TTy = Self.Context.getPointerType(TTy); 1087 else if(TTy->isArrayType()) 1088 TTy = Self.Context.getArrayDecayedType(TTy); 1089 1090 // Now try the implicit conversion. 1091 // FIXME: This doesn't detect ambiguities. 1092 ICS = Self.TryImplicitConversion(From, TTy); 1093 } 1094 return false; 1095} 1096 1097/// \brief Try to find a common type for two according to C++0x 5.16p5. 1098/// 1099/// This is part of the parameter validation for the ? operator. If either 1100/// value operand is a class type, overload resolution is used to find a 1101/// conversion to a common type. 1102static bool FindConditionalOverload(Sema &Self, Expr *&LHS, Expr *&RHS, 1103 SourceLocation Loc) { 1104 Expr *Args[2] = { LHS, RHS }; 1105 OverloadCandidateSet CandidateSet; 1106 Self.AddBuiltinOperatorCandidates(OO_Conditional, Args, 2, CandidateSet); 1107 1108 OverloadCandidateSet::iterator Best; 1109 switch (Self.BestViableFunction(CandidateSet, Best)) { 1110 case Sema::OR_Success: 1111 // We found a match. Perform the conversions on the arguments and move on. 1112 if (Self.PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 1113 Best->Conversions[0], "converting") || 1114 Self.PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 1115 Best->Conversions[1], "converting")) 1116 break; 1117 return false; 1118 1119 case Sema::OR_No_Viable_Function: 1120 Self.Diag(Loc, diag::err_typecheck_cond_incompatible_operands) 1121 << LHS->getType() << RHS->getType() 1122 << LHS->getSourceRange() << RHS->getSourceRange(); 1123 return true; 1124 1125 case Sema::OR_Ambiguous: 1126 Self.Diag(Loc, diag::err_conditional_ambiguous_ovl) 1127 << LHS->getType() << RHS->getType() 1128 << LHS->getSourceRange() << RHS->getSourceRange(); 1129 // FIXME: Print the possible common types by printing the return types 1130 // of the viable candidates. 1131 break; 1132 1133 case Sema::OR_Deleted: 1134 assert(false && "Conditional operator has only built-in overloads"); 1135 break; 1136 } 1137 return true; 1138} 1139 1140/// \brief Perform an "extended" implicit conversion as returned by 1141/// TryClassUnification. 1142/// 1143/// TryClassUnification generates ICSs that include reference bindings. 1144/// PerformImplicitConversion is not suitable for this; it chokes if the 1145/// second part of a standard conversion is ICK_DerivedToBase. This function 1146/// handles the reference binding specially. 1147static bool ConvertForConditional(Sema &Self, Expr *&E, 1148 const ImplicitConversionSequence &ICS) 1149{ 1150 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion && 1151 ICS.Standard.ReferenceBinding) { 1152 assert(ICS.Standard.DirectBinding && 1153 "TryClassUnification should never generate indirect ref bindings"); 1154 Self.ImpCastExprToType(E, TargetType(ICS), true); 1155 return false; 1156 } 1157 if (ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion && 1158 ICS.UserDefined.After.ReferenceBinding) { 1159 assert(ICS.UserDefined.After.DirectBinding && 1160 "TryClassUnification should never generate indirect ref bindings"); 1161 Self.ImpCastExprToType(E, TargetType(ICS), true); 1162 return false; 1163 } 1164 if (Self.PerformImplicitConversion(E, TargetType(ICS), ICS, "converting")) 1165 return true; 1166 return false; 1167} 1168 1169/// \brief Check the operands of ?: under C++ semantics. 1170/// 1171/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 1172/// extension. In this case, LHS == Cond. (But they're not aliases.) 1173QualType Sema::CXXCheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 1174 SourceLocation QuestionLoc) { 1175 // FIXME: Handle C99's complex types, vector types, block pointers and 1176 // Obj-C++ interface pointers. 1177 1178 // C++0x 5.16p1 1179 // The first expression is contextually converted to bool. 1180 if (!Cond->isTypeDependent()) { 1181 if (CheckCXXBooleanCondition(Cond)) 1182 return QualType(); 1183 } 1184 1185 // Either of the arguments dependent? 1186 if (LHS->isTypeDependent() || RHS->isTypeDependent()) 1187 return Context.DependentTy; 1188 1189 // C++0x 5.16p2 1190 // If either the second or the third operand has type (cv) void, ... 1191 QualType LTy = LHS->getType(); 1192 QualType RTy = RHS->getType(); 1193 bool LVoid = LTy->isVoidType(); 1194 bool RVoid = RTy->isVoidType(); 1195 if (LVoid || RVoid) { 1196 // ... then the [l2r] conversions are performed on the second and third 1197 // operands ... 1198 DefaultFunctionArrayConversion(LHS); 1199 DefaultFunctionArrayConversion(RHS); 1200 LTy = LHS->getType(); 1201 RTy = RHS->getType(); 1202 1203 // ... and one of the following shall hold: 1204 // -- The second or the third operand (but not both) is a throw- 1205 // expression; the result is of the type of the other and is an rvalue. 1206 bool LThrow = isa<CXXThrowExpr>(LHS); 1207 bool RThrow = isa<CXXThrowExpr>(RHS); 1208 if (LThrow && !RThrow) 1209 return RTy; 1210 if (RThrow && !LThrow) 1211 return LTy; 1212 1213 // -- Both the second and third operands have type void; the result is of 1214 // type void and is an rvalue. 1215 if (LVoid && RVoid) 1216 return Context.VoidTy; 1217 1218 // Neither holds, error. 1219 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 1220 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 1221 << LHS->getSourceRange() << RHS->getSourceRange(); 1222 return QualType(); 1223 } 1224 1225 // Neither is void. 1226 1227 // C++0x 5.16p3 1228 // Otherwise, if the second and third operand have different types, and 1229 // either has (cv) class type, and attempt is made to convert each of those 1230 // operands to the other. 1231 if (Context.getCanonicalType(LTy) != Context.getCanonicalType(RTy) && 1232 (LTy->isRecordType() || RTy->isRecordType())) { 1233 ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft; 1234 // These return true if a single direction is already ambiguous. 1235 if (TryClassUnification(*this, LHS, RHS, QuestionLoc, ICSLeftToRight)) 1236 return QualType(); 1237 if (TryClassUnification(*this, RHS, LHS, QuestionLoc, ICSRightToLeft)) 1238 return QualType(); 1239 1240 bool HaveL2R = ICSLeftToRight.ConversionKind != 1241 ImplicitConversionSequence::BadConversion; 1242 bool HaveR2L = ICSRightToLeft.ConversionKind != 1243 ImplicitConversionSequence::BadConversion; 1244 // If both can be converted, [...] the program is ill-formed. 1245 if (HaveL2R && HaveR2L) { 1246 Diag(QuestionLoc, diag::err_conditional_ambiguous) 1247 << LTy << RTy << LHS->getSourceRange() << RHS->getSourceRange(); 1248 return QualType(); 1249 } 1250 1251 // If exactly one conversion is possible, that conversion is applied to 1252 // the chosen operand and the converted operands are used in place of the 1253 // original operands for the remainder of this section. 1254 if (HaveL2R) { 1255 if (ConvertForConditional(*this, LHS, ICSLeftToRight)) 1256 return QualType(); 1257 LTy = LHS->getType(); 1258 } else if (HaveR2L) { 1259 if (ConvertForConditional(*this, RHS, ICSRightToLeft)) 1260 return QualType(); 1261 RTy = RHS->getType(); 1262 } 1263 } 1264 1265 // C++0x 5.16p4 1266 // If the second and third operands are lvalues and have the same type, 1267 // the result is of that type [...] 1268 bool Same = Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy); 1269 if (Same && LHS->isLvalue(Context) == Expr::LV_Valid && 1270 RHS->isLvalue(Context) == Expr::LV_Valid) 1271 return LTy; 1272 1273 // C++0x 5.16p5 1274 // Otherwise, the result is an rvalue. If the second and third operands 1275 // do not have the same type, and either has (cv) class type, ... 1276 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 1277 // ... overload resolution is used to determine the conversions (if any) 1278 // to be applied to the operands. If the overload resolution fails, the 1279 // program is ill-formed. 1280 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 1281 return QualType(); 1282 } 1283 1284 // C++0x 5.16p6 1285 // LValue-to-rvalue, array-to-pointer, and function-to-pointer standard 1286 // conversions are performed on the second and third operands. 1287 DefaultFunctionArrayConversion(LHS); 1288 DefaultFunctionArrayConversion(RHS); 1289 LTy = LHS->getType(); 1290 RTy = RHS->getType(); 1291 1292 // After those conversions, one of the following shall hold: 1293 // -- The second and third operands have the same type; the result 1294 // is of that type. 1295 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) 1296 return LTy; 1297 1298 // -- The second and third operands have arithmetic or enumeration type; 1299 // the usual arithmetic conversions are performed to bring them to a 1300 // common type, and the result is of that type. 1301 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 1302 UsualArithmeticConversions(LHS, RHS); 1303 return LHS->getType(); 1304 } 1305 1306 // -- The second and third operands have pointer type, or one has pointer 1307 // type and the other is a null pointer constant; pointer conversions 1308 // and qualification conversions are performed to bring them to their 1309 // composite pointer type. The result is of the composite pointer type. 1310 // Fourth bullet is same for pointers-to-member. 1311 if ((LTy->isPointerType() || LTy->isMemberPointerType()) && 1312 RHS->isNullPointerConstant(Context)) { 1313 ImpCastExprToType(RHS, LTy); // promote the null to a pointer. 1314 return LTy; 1315 } 1316 if ((RTy->isPointerType() || RTy->isMemberPointerType()) && 1317 LHS->isNullPointerConstant(Context)) { 1318 ImpCastExprToType(LHS, RTy); // promote the null to a pointer. 1319 return RTy; 1320 } 1321 1322 // FIXME: Handle the case where both are pointers. 1323 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 1324 << LHS->getType() << RHS->getType() 1325 << LHS->getSourceRange() << RHS->getSourceRange(); 1326 return QualType(); 1327} 1328