SemaExpr.cpp revision b28e006e904273e8215c3d51612fbbd5dfc14f92
1//===--- SemaExpr.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 expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInit.h" 16#include "Lookup.h" 17#include "AnalysisBasedWarnings.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/DeclTemplate.h" 21#include "clang/AST/ExprCXX.h" 22#include "clang/AST/ExprObjC.h" 23#include "clang/Basic/PartialDiagnostic.h" 24#include "clang/Basic/SourceManager.h" 25#include "clang/Basic/TargetInfo.h" 26#include "clang/Lex/LiteralSupport.h" 27#include "clang/Lex/Preprocessor.h" 28#include "clang/Parse/DeclSpec.h" 29#include "clang/Parse/Designator.h" 30#include "clang/Parse/Scope.h" 31#include "clang/Parse/Template.h" 32using namespace clang; 33 34 35/// \brief Determine whether the use of this declaration is valid, and 36/// emit any corresponding diagnostics. 37/// 38/// This routine diagnoses various problems with referencing 39/// declarations that can occur when using a declaration. For example, 40/// it might warn if a deprecated or unavailable declaration is being 41/// used, or produce an error (and return true) if a C++0x deleted 42/// function is being used. 43/// 44/// If IgnoreDeprecated is set to true, this should not want about deprecated 45/// decls. 46/// 47/// \returns true if there was an error (this declaration cannot be 48/// referenced), false otherwise. 49/// 50bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) { 51 // See if the decl is deprecated. 52 if (D->getAttr<DeprecatedAttr>()) { 53 EmitDeprecationWarning(D, Loc); 54 } 55 56 // See if the decl is unavailable 57 if (D->getAttr<UnavailableAttr>()) { 58 Diag(Loc, diag::warn_unavailable) << D->getDeclName(); 59 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 60 } 61 62 // See if this is a deleted function. 63 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 64 if (FD->isDeleted()) { 65 Diag(Loc, diag::err_deleted_function_use); 66 Diag(D->getLocation(), diag::note_unavailable_here) << true; 67 return true; 68 } 69 } 70 71 return false; 72} 73 74/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 75/// (and other functions in future), which have been declared with sentinel 76/// attribute. It warns if call does not have the sentinel argument. 77/// 78void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 79 Expr **Args, unsigned NumArgs) { 80 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 81 if (!attr) 82 return; 83 int sentinelPos = attr->getSentinel(); 84 int nullPos = attr->getNullPos(); 85 86 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 87 // base class. Then we won't be needing two versions of the same code. 88 unsigned int i = 0; 89 bool warnNotEnoughArgs = false; 90 int isMethod = 0; 91 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 92 // skip over named parameters. 93 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 94 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 95 if (nullPos) 96 --nullPos; 97 else 98 ++i; 99 } 100 warnNotEnoughArgs = (P != E || i >= NumArgs); 101 isMethod = 1; 102 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 103 // skip over named parameters. 104 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 105 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 106 if (nullPos) 107 --nullPos; 108 else 109 ++i; 110 } 111 warnNotEnoughArgs = (P != E || i >= NumArgs); 112 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 113 // block or function pointer call. 114 QualType Ty = V->getType(); 115 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 116 const FunctionType *FT = Ty->isFunctionPointerType() 117 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 118 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 119 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 120 unsigned NumArgsInProto = Proto->getNumArgs(); 121 unsigned k; 122 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 123 if (nullPos) 124 --nullPos; 125 else 126 ++i; 127 } 128 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 129 } 130 if (Ty->isBlockPointerType()) 131 isMethod = 2; 132 } else 133 return; 134 } else 135 return; 136 137 if (warnNotEnoughArgs) { 138 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 139 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 140 return; 141 } 142 int sentinel = i; 143 while (sentinelPos > 0 && i < NumArgs-1) { 144 --sentinelPos; 145 ++i; 146 } 147 if (sentinelPos > 0) { 148 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 149 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 150 return; 151 } 152 while (i < NumArgs-1) { 153 ++i; 154 ++sentinel; 155 } 156 Expr *sentinelExpr = Args[sentinel]; 157 if (sentinelExpr && (!isa<GNUNullExpr>(sentinelExpr) && 158 (!sentinelExpr->getType()->isPointerType() || 159 !sentinelExpr->isNullPointerConstant(Context, 160 Expr::NPC_ValueDependentIsNull)))) { 161 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 162 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 163 } 164 return; 165} 166 167SourceRange Sema::getExprRange(ExprTy *E) const { 168 Expr *Ex = (Expr *)E; 169 return Ex? Ex->getSourceRange() : SourceRange(); 170} 171 172//===----------------------------------------------------------------------===// 173// Standard Promotions and Conversions 174//===----------------------------------------------------------------------===// 175 176/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 177void Sema::DefaultFunctionArrayConversion(Expr *&E) { 178 QualType Ty = E->getType(); 179 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 180 181 if (Ty->isFunctionType()) 182 ImpCastExprToType(E, Context.getPointerType(Ty), 183 CastExpr::CK_FunctionToPointerDecay); 184 else if (Ty->isArrayType()) { 185 // In C90 mode, arrays only promote to pointers if the array expression is 186 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 187 // type 'array of type' is converted to an expression that has type 'pointer 188 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 189 // that has type 'array of type' ...". The relevant change is "an lvalue" 190 // (C90) to "an expression" (C99). 191 // 192 // C++ 4.2p1: 193 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 194 // T" can be converted to an rvalue of type "pointer to T". 195 // 196 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 197 E->isLvalue(Context) == Expr::LV_Valid) 198 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 199 CastExpr::CK_ArrayToPointerDecay); 200 } 201} 202 203void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 204 DefaultFunctionArrayConversion(E); 205 206 QualType Ty = E->getType(); 207 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 208 if (!Ty->isDependentType() && Ty.hasQualifiers() && 209 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 210 E->isLvalue(Context) == Expr::LV_Valid) { 211 // C++ [conv.lval]p1: 212 // [...] If T is a non-class type, the type of the rvalue is the 213 // cv-unqualified version of T. Otherwise, the type of the 214 // rvalue is T 215 // 216 // C99 6.3.2.1p2: 217 // If the lvalue has qualified type, the value has the unqualified 218 // version of the type of the lvalue; otherwise, the value has the 219 // type of the lvalue. 220 ImpCastExprToType(E, Ty.getUnqualifiedType(), CastExpr::CK_NoOp); 221 } 222} 223 224 225/// UsualUnaryConversions - Performs various conversions that are common to most 226/// operators (C99 6.3). The conversions of array and function types are 227/// sometimes surpressed. For example, the array->pointer conversion doesn't 228/// apply if the array is an argument to the sizeof or address (&) operators. 229/// In these instances, this routine should *not* be called. 230Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 231 QualType Ty = Expr->getType(); 232 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 233 234 // C99 6.3.1.1p2: 235 // 236 // The following may be used in an expression wherever an int or 237 // unsigned int may be used: 238 // - an object or expression with an integer type whose integer 239 // conversion rank is less than or equal to the rank of int 240 // and unsigned int. 241 // - A bit-field of type _Bool, int, signed int, or unsigned int. 242 // 243 // If an int can represent all values of the original type, the 244 // value is converted to an int; otherwise, it is converted to an 245 // unsigned int. These are called the integer promotions. All 246 // other types are unchanged by the integer promotions. 247 QualType PTy = Context.isPromotableBitField(Expr); 248 if (!PTy.isNull()) { 249 ImpCastExprToType(Expr, PTy, CastExpr::CK_IntegralCast); 250 return Expr; 251 } 252 if (Ty->isPromotableIntegerType()) { 253 QualType PT = Context.getPromotedIntegerType(Ty); 254 ImpCastExprToType(Expr, PT, CastExpr::CK_IntegralCast); 255 return Expr; 256 } 257 258 DefaultFunctionArrayLvalueConversion(Expr); 259 return Expr; 260} 261 262/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 263/// do not have a prototype. Arguments that have type float are promoted to 264/// double. All other argument types are converted by UsualUnaryConversions(). 265void Sema::DefaultArgumentPromotion(Expr *&Expr) { 266 QualType Ty = Expr->getType(); 267 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 268 269 // If this is a 'float' (CVR qualified or typedef) promote to double. 270 if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) 271 if (BT->getKind() == BuiltinType::Float) 272 return ImpCastExprToType(Expr, Context.DoubleTy, 273 CastExpr::CK_FloatingCast); 274 275 UsualUnaryConversions(Expr); 276} 277 278/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 279/// will warn if the resulting type is not a POD type, and rejects ObjC 280/// interfaces passed by value. This returns true if the argument type is 281/// completely illegal. 282bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT) { 283 DefaultArgumentPromotion(Expr); 284 285 if (Expr->getType()->isObjCInterfaceType() && 286 DiagRuntimeBehavior(Expr->getLocStart(), 287 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 288 << Expr->getType() << CT)) 289 return true; 290 291 if (!Expr->getType()->isPODType() && 292 DiagRuntimeBehavior(Expr->getLocStart(), 293 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 294 << Expr->getType() << CT)) 295 return true; 296 297 return false; 298} 299 300 301/// UsualArithmeticConversions - Performs various conversions that are common to 302/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 303/// routine returns the first non-arithmetic type found. The client is 304/// responsible for emitting appropriate error diagnostics. 305/// FIXME: verify the conversion rules for "complex int" are consistent with 306/// GCC. 307QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 308 bool isCompAssign) { 309 if (!isCompAssign) 310 UsualUnaryConversions(lhsExpr); 311 312 UsualUnaryConversions(rhsExpr); 313 314 // For conversion purposes, we ignore any qualifiers. 315 // For example, "const float" and "float" are equivalent. 316 QualType lhs = 317 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 318 QualType rhs = 319 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 320 321 // If both types are identical, no conversion is needed. 322 if (lhs == rhs) 323 return lhs; 324 325 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 326 // The caller can deal with this (e.g. pointer + int). 327 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 328 return lhs; 329 330 // Perform bitfield promotions. 331 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 332 if (!LHSBitfieldPromoteTy.isNull()) 333 lhs = LHSBitfieldPromoteTy; 334 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 335 if (!RHSBitfieldPromoteTy.isNull()) 336 rhs = RHSBitfieldPromoteTy; 337 338 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 339 if (!isCompAssign) 340 ImpCastExprToType(lhsExpr, destType, CastExpr::CK_Unknown); 341 ImpCastExprToType(rhsExpr, destType, CastExpr::CK_Unknown); 342 return destType; 343} 344 345//===----------------------------------------------------------------------===// 346// Semantic Analysis for various Expression Types 347//===----------------------------------------------------------------------===// 348 349 350/// ActOnStringLiteral - The specified tokens were lexed as pasted string 351/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 352/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 353/// multiple tokens. However, the common case is that StringToks points to one 354/// string. 355/// 356Action::OwningExprResult 357Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 358 assert(NumStringToks && "Must have at least one string!"); 359 360 StringLiteralParser Literal(StringToks, NumStringToks, PP); 361 if (Literal.hadError) 362 return ExprError(); 363 364 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 365 for (unsigned i = 0; i != NumStringToks; ++i) 366 StringTokLocs.push_back(StringToks[i].getLocation()); 367 368 QualType StrTy = Context.CharTy; 369 if (Literal.AnyWide) StrTy = Context.getWCharType(); 370 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 371 372 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 373 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings ) 374 StrTy.addConst(); 375 376 // Get an array type for the string, according to C99 6.4.5. This includes 377 // the nul terminator character as well as the string length for pascal 378 // strings. 379 StrTy = Context.getConstantArrayType(StrTy, 380 llvm::APInt(32, Literal.GetNumStringChars()+1), 381 ArrayType::Normal, 0); 382 383 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 384 return Owned(StringLiteral::Create(Context, Literal.GetString(), 385 Literal.GetStringLength(), 386 Literal.AnyWide, StrTy, 387 &StringTokLocs[0], 388 StringTokLocs.size())); 389} 390 391/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 392/// CurBlock to VD should cause it to be snapshotted (as we do for auto 393/// variables defined outside the block) or false if this is not needed (e.g. 394/// for values inside the block or for globals). 395/// 396/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 397/// up-to-date. 398/// 399static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 400 ValueDecl *VD) { 401 // If the value is defined inside the block, we couldn't snapshot it even if 402 // we wanted to. 403 if (CurBlock->TheDecl == VD->getDeclContext()) 404 return false; 405 406 // If this is an enum constant or function, it is constant, don't snapshot. 407 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 408 return false; 409 410 // If this is a reference to an extern, static, or global variable, no need to 411 // snapshot it. 412 // FIXME: What about 'const' variables in C++? 413 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 414 if (!Var->hasLocalStorage()) 415 return false; 416 417 // Blocks that have these can't be constant. 418 CurBlock->hasBlockDeclRefExprs = true; 419 420 // If we have nested blocks, the decl may be declared in an outer block (in 421 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 422 // be defined outside all of the current blocks (in which case the blocks do 423 // all get the bit). Walk the nesting chain. 424 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 425 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 426 427 if (!NextBlock) 428 continue; 429 430 // If we found the defining block for the variable, don't mark the block as 431 // having a reference outside it. 432 if (NextBlock->TheDecl == VD->getDeclContext()) 433 break; 434 435 // Otherwise, the DeclRef from the inner block causes the outer one to need 436 // a snapshot as well. 437 NextBlock->hasBlockDeclRefExprs = true; 438 } 439 440 return true; 441} 442 443 444 445/// BuildDeclRefExpr - Build a DeclRefExpr. 446Sema::OwningExprResult 447Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, SourceLocation Loc, 448 const CXXScopeSpec *SS) { 449 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 450 Diag(Loc, 451 diag::err_auto_variable_cannot_appear_in_own_initializer) 452 << D->getDeclName(); 453 return ExprError(); 454 } 455 456 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 457 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 458 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 459 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 460 Diag(Loc, diag::err_reference_to_local_var_in_enclosing_function) 461 << D->getIdentifier() << FD->getDeclName(); 462 Diag(D->getLocation(), diag::note_local_variable_declared_here) 463 << D->getIdentifier(); 464 return ExprError(); 465 } 466 } 467 } 468 } 469 470 MarkDeclarationReferenced(Loc, D); 471 472 return Owned(DeclRefExpr::Create(Context, 473 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 474 SS? SS->getRange() : SourceRange(), 475 D, Loc, Ty)); 476} 477 478/// getObjectForAnonymousRecordDecl - Retrieve the (unnamed) field or 479/// variable corresponding to the anonymous union or struct whose type 480/// is Record. 481static Decl *getObjectForAnonymousRecordDecl(ASTContext &Context, 482 RecordDecl *Record) { 483 assert(Record->isAnonymousStructOrUnion() && 484 "Record must be an anonymous struct or union!"); 485 486 // FIXME: Once Decls are directly linked together, this will be an O(1) 487 // operation rather than a slow walk through DeclContext's vector (which 488 // itself will be eliminated). DeclGroups might make this even better. 489 DeclContext *Ctx = Record->getDeclContext(); 490 for (DeclContext::decl_iterator D = Ctx->decls_begin(), 491 DEnd = Ctx->decls_end(); 492 D != DEnd; ++D) { 493 if (*D == Record) { 494 // The object for the anonymous struct/union directly 495 // follows its type in the list of declarations. 496 ++D; 497 assert(D != DEnd && "Missing object for anonymous record"); 498 assert(!cast<NamedDecl>(*D)->getDeclName() && "Decl should be unnamed"); 499 return *D; 500 } 501 } 502 503 assert(false && "Missing object for anonymous record"); 504 return 0; 505} 506 507/// \brief Given a field that represents a member of an anonymous 508/// struct/union, build the path from that field's context to the 509/// actual member. 510/// 511/// Construct the sequence of field member references we'll have to 512/// perform to get to the field in the anonymous union/struct. The 513/// list of members is built from the field outward, so traverse it 514/// backwards to go from an object in the current context to the field 515/// we found. 516/// 517/// \returns The variable from which the field access should begin, 518/// for an anonymous struct/union that is not a member of another 519/// class. Otherwise, returns NULL. 520VarDecl *Sema::BuildAnonymousStructUnionMemberPath(FieldDecl *Field, 521 llvm::SmallVectorImpl<FieldDecl *> &Path) { 522 assert(Field->getDeclContext()->isRecord() && 523 cast<RecordDecl>(Field->getDeclContext())->isAnonymousStructOrUnion() 524 && "Field must be stored inside an anonymous struct or union"); 525 526 Path.push_back(Field); 527 VarDecl *BaseObject = 0; 528 DeclContext *Ctx = Field->getDeclContext(); 529 do { 530 RecordDecl *Record = cast<RecordDecl>(Ctx); 531 Decl *AnonObject = getObjectForAnonymousRecordDecl(Context, Record); 532 if (FieldDecl *AnonField = dyn_cast<FieldDecl>(AnonObject)) 533 Path.push_back(AnonField); 534 else { 535 BaseObject = cast<VarDecl>(AnonObject); 536 break; 537 } 538 Ctx = Ctx->getParent(); 539 } while (Ctx->isRecord() && 540 cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()); 541 542 return BaseObject; 543} 544 545Sema::OwningExprResult 546Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 547 FieldDecl *Field, 548 Expr *BaseObjectExpr, 549 SourceLocation OpLoc) { 550 llvm::SmallVector<FieldDecl *, 4> AnonFields; 551 VarDecl *BaseObject = BuildAnonymousStructUnionMemberPath(Field, 552 AnonFields); 553 554 // Build the expression that refers to the base object, from 555 // which we will build a sequence of member references to each 556 // of the anonymous union objects and, eventually, the field we 557 // found via name lookup. 558 bool BaseObjectIsPointer = false; 559 Qualifiers BaseQuals; 560 if (BaseObject) { 561 // BaseObject is an anonymous struct/union variable (and is, 562 // therefore, not part of another non-anonymous record). 563 if (BaseObjectExpr) BaseObjectExpr->Destroy(Context); 564 MarkDeclarationReferenced(Loc, BaseObject); 565 BaseObjectExpr = new (Context) DeclRefExpr(BaseObject,BaseObject->getType(), 566 SourceLocation()); 567 BaseQuals 568 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 569 } else if (BaseObjectExpr) { 570 // The caller provided the base object expression. Determine 571 // whether its a pointer and whether it adds any qualifiers to the 572 // anonymous struct/union fields we're looking into. 573 QualType ObjectType = BaseObjectExpr->getType(); 574 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 575 BaseObjectIsPointer = true; 576 ObjectType = ObjectPtr->getPointeeType(); 577 } 578 BaseQuals 579 = Context.getCanonicalType(ObjectType).getQualifiers(); 580 } else { 581 // We've found a member of an anonymous struct/union that is 582 // inside a non-anonymous struct/union, so in a well-formed 583 // program our base object expression is "this". 584 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 585 if (!MD->isStatic()) { 586 QualType AnonFieldType 587 = Context.getTagDeclType( 588 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 589 QualType ThisType = Context.getTagDeclType(MD->getParent()); 590 if ((Context.getCanonicalType(AnonFieldType) 591 == Context.getCanonicalType(ThisType)) || 592 IsDerivedFrom(ThisType, AnonFieldType)) { 593 // Our base object expression is "this". 594 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 595 MD->getThisType(Context), 596 /*isImplicit=*/true); 597 BaseObjectIsPointer = true; 598 } 599 } else { 600 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 601 << Field->getDeclName()); 602 } 603 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 604 } 605 606 if (!BaseObjectExpr) 607 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 608 << Field->getDeclName()); 609 } 610 611 // Build the implicit member references to the field of the 612 // anonymous struct/union. 613 Expr *Result = BaseObjectExpr; 614 Qualifiers ResultQuals = BaseQuals; 615 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 616 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 617 FI != FIEnd; ++FI) { 618 QualType MemberType = (*FI)->getType(); 619 Qualifiers MemberTypeQuals = 620 Context.getCanonicalType(MemberType).getQualifiers(); 621 622 // CVR attributes from the base are picked up by members, 623 // except that 'mutable' members don't pick up 'const'. 624 if ((*FI)->isMutable()) 625 ResultQuals.removeConst(); 626 627 // GC attributes are never picked up by members. 628 ResultQuals.removeObjCGCAttr(); 629 630 // TR 18037 does not allow fields to be declared with address spaces. 631 assert(!MemberTypeQuals.hasAddressSpace()); 632 633 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 634 if (NewQuals != MemberTypeQuals) 635 MemberType = Context.getQualifiedType(MemberType, NewQuals); 636 637 MarkDeclarationReferenced(Loc, *FI); 638 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 639 // FIXME: Might this end up being a qualified name? 640 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 641 OpLoc, MemberType); 642 BaseObjectIsPointer = false; 643 ResultQuals = NewQuals; 644 } 645 646 return Owned(Result); 647} 648 649/// Decomposes the given name into a DeclarationName, its location, and 650/// possibly a list of template arguments. 651/// 652/// If this produces template arguments, it is permitted to call 653/// DecomposeTemplateName. 654/// 655/// This actually loses a lot of source location information for 656/// non-standard name kinds; we should consider preserving that in 657/// some way. 658static void DecomposeUnqualifiedId(Sema &SemaRef, 659 const UnqualifiedId &Id, 660 TemplateArgumentListInfo &Buffer, 661 DeclarationName &Name, 662 SourceLocation &NameLoc, 663 const TemplateArgumentListInfo *&TemplateArgs) { 664 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 665 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 666 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 667 668 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 669 Id.TemplateId->getTemplateArgs(), 670 Id.TemplateId->NumArgs); 671 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 672 TemplateArgsPtr.release(); 673 674 TemplateName TName = 675 Sema::TemplateTy::make(Id.TemplateId->Template).getAsVal<TemplateName>(); 676 677 Name = SemaRef.Context.getNameForTemplate(TName); 678 NameLoc = Id.TemplateId->TemplateNameLoc; 679 TemplateArgs = &Buffer; 680 } else { 681 Name = SemaRef.GetNameFromUnqualifiedId(Id); 682 NameLoc = Id.StartLocation; 683 TemplateArgs = 0; 684 } 685} 686 687/// Decompose the given template name into a list of lookup results. 688/// 689/// The unqualified ID must name a non-dependent template, which can 690/// be more easily tested by checking whether DecomposeUnqualifiedId 691/// found template arguments. 692static void DecomposeTemplateName(LookupResult &R, const UnqualifiedId &Id) { 693 assert(Id.getKind() == UnqualifiedId::IK_TemplateId); 694 TemplateName TName = 695 Sema::TemplateTy::make(Id.TemplateId->Template).getAsVal<TemplateName>(); 696 697 if (TemplateDecl *TD = TName.getAsTemplateDecl()) 698 R.addDecl(TD); 699 else if (OverloadedTemplateStorage *OT = TName.getAsOverloadedTemplate()) 700 for (OverloadedTemplateStorage::iterator I = OT->begin(), E = OT->end(); 701 I != E; ++I) 702 R.addDecl(*I); 703 704 R.resolveKind(); 705} 706 707/// Determines whether the given record is "fully-formed" at the given 708/// location, i.e. whether a qualified lookup into it is assured of 709/// getting consistent results already. 710static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 711 if (!Record->hasDefinition()) 712 return false; 713 714 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 715 E = Record->bases_end(); I != E; ++I) { 716 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 717 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 718 if (!BaseRT) return false; 719 720 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 721 if (!BaseRecord->hasDefinition() || 722 !IsFullyFormedScope(SemaRef, BaseRecord)) 723 return false; 724 } 725 726 return true; 727} 728 729/// Determines whether we can lookup this id-expression now or whether 730/// we have to wait until template instantiation is complete. 731static bool IsDependentIdExpression(Sema &SemaRef, const CXXScopeSpec &SS) { 732 DeclContext *DC = SemaRef.computeDeclContext(SS, false); 733 734 // If the qualifier scope isn't computable, it's definitely dependent. 735 if (!DC) return true; 736 737 // If the qualifier scope doesn't name a record, we can always look into it. 738 if (!isa<CXXRecordDecl>(DC)) return false; 739 740 // We can't look into record types unless they're fully-formed. 741 if (!IsFullyFormedScope(SemaRef, cast<CXXRecordDecl>(DC))) return true; 742 743 return false; 744} 745 746/// Determines if the given class is provably not derived from all of 747/// the prospective base classes. 748static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 749 CXXRecordDecl *Record, 750 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 751 if (Bases.count(Record->getCanonicalDecl())) 752 return false; 753 754 RecordDecl *RD = Record->getDefinition(); 755 if (!RD) return false; 756 Record = cast<CXXRecordDecl>(RD); 757 758 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 759 E = Record->bases_end(); I != E; ++I) { 760 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 761 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 762 if (!BaseRT) return false; 763 764 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 765 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 766 return false; 767 } 768 769 return true; 770} 771 772/// Determines if this is an instance member of a class. 773static bool IsInstanceMember(NamedDecl *D) { 774 assert(D->isCXXClassMember() && 775 "checking whether non-member is instance member"); 776 777 if (isa<FieldDecl>(D)) return true; 778 779 if (isa<CXXMethodDecl>(D)) 780 return !cast<CXXMethodDecl>(D)->isStatic(); 781 782 if (isa<FunctionTemplateDecl>(D)) { 783 D = cast<FunctionTemplateDecl>(D)->getTemplatedDecl(); 784 return !cast<CXXMethodDecl>(D)->isStatic(); 785 } 786 787 return false; 788} 789 790enum IMAKind { 791 /// The reference is definitely not an instance member access. 792 IMA_Static, 793 794 /// The reference may be an implicit instance member access. 795 IMA_Mixed, 796 797 /// The reference may be to an instance member, but it is invalid if 798 /// so, because the context is not an instance method. 799 IMA_Mixed_StaticContext, 800 801 /// The reference may be to an instance member, but it is invalid if 802 /// so, because the context is from an unrelated class. 803 IMA_Mixed_Unrelated, 804 805 /// The reference is definitely an implicit instance member access. 806 IMA_Instance, 807 808 /// The reference may be to an unresolved using declaration. 809 IMA_Unresolved, 810 811 /// The reference may be to an unresolved using declaration and the 812 /// context is not an instance method. 813 IMA_Unresolved_StaticContext, 814 815 /// The reference is to a member of an anonymous structure in a 816 /// non-class context. 817 IMA_AnonymousMember, 818 819 /// All possible referrents are instance members and the current 820 /// context is not an instance method. 821 IMA_Error_StaticContext, 822 823 /// All possible referrents are instance members of an unrelated 824 /// class. 825 IMA_Error_Unrelated 826}; 827 828/// The given lookup names class member(s) and is not being used for 829/// an address-of-member expression. Classify the type of access 830/// according to whether it's possible that this reference names an 831/// instance member. This is best-effort; it is okay to 832/// conservatively answer "yes", in which case some errors will simply 833/// not be caught until template-instantiation. 834static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 835 const LookupResult &R) { 836 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 837 838 bool isStaticContext = 839 (!isa<CXXMethodDecl>(SemaRef.CurContext) || 840 cast<CXXMethodDecl>(SemaRef.CurContext)->isStatic()); 841 842 if (R.isUnresolvableResult()) 843 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 844 845 // Collect all the declaring classes of instance members we find. 846 bool hasNonInstance = false; 847 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 848 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 849 NamedDecl *D = (*I)->getUnderlyingDecl(); 850 if (IsInstanceMember(D)) { 851 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 852 853 // If this is a member of an anonymous record, move out to the 854 // innermost non-anonymous struct or union. If there isn't one, 855 // that's a special case. 856 while (R->isAnonymousStructOrUnion()) { 857 R = dyn_cast<CXXRecordDecl>(R->getParent()); 858 if (!R) return IMA_AnonymousMember; 859 } 860 Classes.insert(R->getCanonicalDecl()); 861 } 862 else 863 hasNonInstance = true; 864 } 865 866 // If we didn't find any instance members, it can't be an implicit 867 // member reference. 868 if (Classes.empty()) 869 return IMA_Static; 870 871 // If the current context is not an instance method, it can't be 872 // an implicit member reference. 873 if (isStaticContext) 874 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 875 876 // If we can prove that the current context is unrelated to all the 877 // declaring classes, it can't be an implicit member reference (in 878 // which case it's an error if any of those members are selected). 879 if (IsProvablyNotDerivedFrom(SemaRef, 880 cast<CXXMethodDecl>(SemaRef.CurContext)->getParent(), 881 Classes)) 882 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 883 884 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 885} 886 887/// Diagnose a reference to a field with no object available. 888static void DiagnoseInstanceReference(Sema &SemaRef, 889 const CXXScopeSpec &SS, 890 const LookupResult &R) { 891 SourceLocation Loc = R.getNameLoc(); 892 SourceRange Range(Loc); 893 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 894 895 if (R.getAsSingle<FieldDecl>()) { 896 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 897 if (MD->isStatic()) { 898 // "invalid use of member 'x' in static member function" 899 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 900 << Range << R.getLookupName(); 901 return; 902 } 903 } 904 905 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 906 << R.getLookupName() << Range; 907 return; 908 } 909 910 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 911} 912 913/// Diagnose an empty lookup. 914/// 915/// \return false if new lookup candidates were found 916bool Sema::DiagnoseEmptyLookup(Scope *S, const CXXScopeSpec &SS, 917 LookupResult &R) { 918 DeclarationName Name = R.getLookupName(); 919 920 unsigned diagnostic = diag::err_undeclared_var_use; 921 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 922 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 923 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 924 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 925 diagnostic = diag::err_undeclared_use; 926 diagnostic_suggest = diag::err_undeclared_use_suggest; 927 } 928 929 // If the original lookup was an unqualified lookup, fake an 930 // unqualified lookup. This is useful when (for example) the 931 // original lookup would not have found something because it was a 932 // dependent name. 933 for (DeclContext *DC = SS.isEmpty()? CurContext : 0; 934 DC; DC = DC->getParent()) { 935 if (isa<CXXRecordDecl>(DC)) { 936 LookupQualifiedName(R, DC); 937 938 if (!R.empty()) { 939 // Don't give errors about ambiguities in this lookup. 940 R.suppressDiagnostics(); 941 942 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 943 bool isInstance = CurMethod && 944 CurMethod->isInstance() && 945 DC == CurMethod->getParent(); 946 947 // Give a code modification hint to insert 'this->'. 948 // TODO: fixit for inserting 'Base<T>::' in the other cases. 949 // Actually quite difficult! 950 if (isInstance) 951 Diag(R.getNameLoc(), diagnostic) << Name 952 << CodeModificationHint::CreateInsertion(R.getNameLoc(), 953 "this->"); 954 else 955 Diag(R.getNameLoc(), diagnostic) << Name; 956 957 // Do we really want to note all of these? 958 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 959 Diag((*I)->getLocation(), diag::note_dependent_var_use); 960 961 // Tell the callee to try to recover. 962 return false; 963 } 964 } 965 } 966 967 // We didn't find anything, so try to correct for a typo. 968 if (S && CorrectTypo(R, S, &SS)) { 969 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 970 if (SS.isEmpty()) 971 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 972 << CodeModificationHint::CreateReplacement(R.getNameLoc(), 973 R.getLookupName().getAsString()); 974 else 975 Diag(R.getNameLoc(), diag::err_no_member_suggest) 976 << Name << computeDeclContext(SS, false) << R.getLookupName() 977 << SS.getRange() 978 << CodeModificationHint::CreateReplacement(R.getNameLoc(), 979 R.getLookupName().getAsString()); 980 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 981 Diag(ND->getLocation(), diag::note_previous_decl) 982 << ND->getDeclName(); 983 984 // Tell the callee to try to recover. 985 return false; 986 } 987 988 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 989 // FIXME: If we ended up with a typo for a type name or 990 // Objective-C class name, we're in trouble because the parser 991 // is in the wrong place to recover. Suggest the typo 992 // correction, but don't make it a fix-it since we're not going 993 // to recover well anyway. 994 if (SS.isEmpty()) 995 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 996 else 997 Diag(R.getNameLoc(), diag::err_no_member_suggest) 998 << Name << computeDeclContext(SS, false) << R.getLookupName() 999 << SS.getRange(); 1000 1001 // Don't try to recover; it won't work. 1002 return true; 1003 } 1004 1005 R.clear(); 1006 } 1007 1008 // Emit a special diagnostic for failed member lookups. 1009 // FIXME: computing the declaration context might fail here (?) 1010 if (!SS.isEmpty()) { 1011 Diag(R.getNameLoc(), diag::err_no_member) 1012 << Name << computeDeclContext(SS, false) 1013 << SS.getRange(); 1014 return true; 1015 } 1016 1017 // Give up, we can't recover. 1018 Diag(R.getNameLoc(), diagnostic) << Name; 1019 return true; 1020} 1021 1022Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S, 1023 const CXXScopeSpec &SS, 1024 UnqualifiedId &Id, 1025 bool HasTrailingLParen, 1026 bool isAddressOfOperand) { 1027 assert(!(isAddressOfOperand && HasTrailingLParen) && 1028 "cannot be direct & operand and have a trailing lparen"); 1029 1030 if (SS.isInvalid()) 1031 return ExprError(); 1032 1033 TemplateArgumentListInfo TemplateArgsBuffer; 1034 1035 // Decompose the UnqualifiedId into the following data. 1036 DeclarationName Name; 1037 SourceLocation NameLoc; 1038 const TemplateArgumentListInfo *TemplateArgs; 1039 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 1040 Name, NameLoc, TemplateArgs); 1041 1042 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1043 1044 // C++ [temp.dep.expr]p3: 1045 // An id-expression is type-dependent if it contains: 1046 // -- an identifier that was declared with a dependent type, 1047 // (note: handled after lookup) 1048 // -- a template-id that is dependent, 1049 // (note: handled in BuildTemplateIdExpr) 1050 // -- a conversion-function-id that specifies a dependent type, 1051 // -- a nested-name-specifier that contains a class-name that 1052 // names a dependent type. 1053 // Determine whether this is a member of an unknown specialization; 1054 // we need to handle these differently. 1055 if ((Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1056 Name.getCXXNameType()->isDependentType()) || 1057 (SS.isSet() && IsDependentIdExpression(*this, SS))) { 1058 return ActOnDependentIdExpression(SS, Name, NameLoc, 1059 isAddressOfOperand, 1060 TemplateArgs); 1061 } 1062 1063 // Perform the required lookup. 1064 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1065 if (TemplateArgs) { 1066 // Just re-use the lookup done by isTemplateName. 1067 DecomposeTemplateName(R, Id); 1068 } else { 1069 bool IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1070 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1071 1072 // If this reference is in an Objective-C method, then we need to do 1073 // some special Objective-C lookup, too. 1074 if (IvarLookupFollowUp) { 1075 OwningExprResult E(LookupInObjCMethod(R, S, II, true)); 1076 if (E.isInvalid()) 1077 return ExprError(); 1078 1079 Expr *Ex = E.takeAs<Expr>(); 1080 if (Ex) return Owned(Ex); 1081 } 1082 } 1083 1084 if (R.isAmbiguous()) 1085 return ExprError(); 1086 1087 // Determine whether this name might be a candidate for 1088 // argument-dependent lookup. 1089 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1090 1091 if (R.empty() && !ADL) { 1092 // Otherwise, this could be an implicitly declared function reference (legal 1093 // in C90, extension in C99, forbidden in C++). 1094 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1095 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1096 if (D) R.addDecl(D); 1097 } 1098 1099 // If this name wasn't predeclared and if this is not a function 1100 // call, diagnose the problem. 1101 if (R.empty()) { 1102 if (DiagnoseEmptyLookup(S, SS, R)) 1103 return ExprError(); 1104 1105 assert(!R.empty() && 1106 "DiagnoseEmptyLookup returned false but added no results"); 1107 1108 // If we found an Objective-C instance variable, let 1109 // LookupInObjCMethod build the appropriate expression to 1110 // reference the ivar. 1111 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1112 R.clear(); 1113 OwningExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1114 assert(E.isInvalid() || E.get()); 1115 return move(E); 1116 } 1117 } 1118 } 1119 1120 // This is guaranteed from this point on. 1121 assert(!R.empty() || ADL); 1122 1123 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1124 // Warn about constructs like: 1125 // if (void *X = foo()) { ... } else { X }. 1126 // In the else block, the pointer is always false. 1127 1128 if (Var->isDeclaredInCondition() && Var->getType()->isScalarType()) { 1129 Scope *CheckS = S; 1130 while (CheckS && CheckS->getControlParent()) { 1131 if (CheckS->isWithinElse() && 1132 CheckS->getControlParent()->isDeclScope(DeclPtrTy::make(Var))) { 1133 ExprError(Diag(NameLoc, diag::warn_value_always_zero) 1134 << Var->getDeclName() 1135 << (Var->getType()->isPointerType()? 2 : 1136 Var->getType()->isBooleanType()? 1 : 0)); 1137 break; 1138 } 1139 1140 // Move to the parent of this scope. 1141 CheckS = CheckS->getParent(); 1142 } 1143 } 1144 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1145 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1146 // C99 DR 316 says that, if a function type comes from a 1147 // function definition (without a prototype), that type is only 1148 // used for checking compatibility. Therefore, when referencing 1149 // the function, we pretend that we don't have the full function 1150 // type. 1151 if (DiagnoseUseOfDecl(Func, NameLoc)) 1152 return ExprError(); 1153 1154 QualType T = Func->getType(); 1155 QualType NoProtoType = T; 1156 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1157 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType()); 1158 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1159 } 1160 } 1161 1162 // Check whether this might be a C++ implicit instance member access. 1163 // C++ [expr.prim.general]p6: 1164 // Within the definition of a non-static member function, an 1165 // identifier that names a non-static member is transformed to a 1166 // class member access expression. 1167 // But note that &SomeClass::foo is grammatically distinct, even 1168 // though we don't parse it that way. 1169 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1170 bool isAbstractMemberPointer = (isAddressOfOperand && !SS.isEmpty()); 1171 if (!isAbstractMemberPointer) 1172 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1173 } 1174 1175 if (TemplateArgs) 1176 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1177 1178 return BuildDeclarationNameExpr(SS, R, ADL); 1179} 1180 1181/// Builds an expression which might be an implicit member expression. 1182Sema::OwningExprResult 1183Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1184 LookupResult &R, 1185 const TemplateArgumentListInfo *TemplateArgs) { 1186 switch (ClassifyImplicitMemberAccess(*this, R)) { 1187 case IMA_Instance: 1188 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1189 1190 case IMA_AnonymousMember: 1191 assert(R.isSingleResult()); 1192 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1193 R.getAsSingle<FieldDecl>()); 1194 1195 case IMA_Mixed: 1196 case IMA_Mixed_Unrelated: 1197 case IMA_Unresolved: 1198 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1199 1200 case IMA_Static: 1201 case IMA_Mixed_StaticContext: 1202 case IMA_Unresolved_StaticContext: 1203 if (TemplateArgs) 1204 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1205 return BuildDeclarationNameExpr(SS, R, false); 1206 1207 case IMA_Error_StaticContext: 1208 case IMA_Error_Unrelated: 1209 DiagnoseInstanceReference(*this, SS, R); 1210 return ExprError(); 1211 } 1212 1213 llvm_unreachable("unexpected instance member access kind"); 1214 return ExprError(); 1215} 1216 1217/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1218/// declaration name, generally during template instantiation. 1219/// There's a large number of things which don't need to be done along 1220/// this path. 1221Sema::OwningExprResult 1222Sema::BuildQualifiedDeclarationNameExpr(const CXXScopeSpec &SS, 1223 DeclarationName Name, 1224 SourceLocation NameLoc) { 1225 DeclContext *DC; 1226 if (!(DC = computeDeclContext(SS, false)) || 1227 DC->isDependentContext() || 1228 RequireCompleteDeclContext(SS)) 1229 return BuildDependentDeclRefExpr(SS, Name, NameLoc, 0); 1230 1231 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1232 LookupQualifiedName(R, DC); 1233 1234 if (R.isAmbiguous()) 1235 return ExprError(); 1236 1237 if (R.empty()) { 1238 Diag(NameLoc, diag::err_no_member) << Name << DC << SS.getRange(); 1239 return ExprError(); 1240 } 1241 1242 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1243} 1244 1245/// LookupInObjCMethod - The parser has read a name in, and Sema has 1246/// detected that we're currently inside an ObjC method. Perform some 1247/// additional lookup. 1248/// 1249/// Ideally, most of this would be done by lookup, but there's 1250/// actually quite a lot of extra work involved. 1251/// 1252/// Returns a null sentinel to indicate trivial success. 1253Sema::OwningExprResult 1254Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1255 IdentifierInfo *II, 1256 bool AllowBuiltinCreation) { 1257 SourceLocation Loc = Lookup.getNameLoc(); 1258 1259 // There are two cases to handle here. 1) scoped lookup could have failed, 1260 // in which case we should look for an ivar. 2) scoped lookup could have 1261 // found a decl, but that decl is outside the current instance method (i.e. 1262 // a global variable). In these two cases, we do a lookup for an ivar with 1263 // this name, if the lookup sucedes, we replace it our current decl. 1264 1265 // If we're in a class method, we don't normally want to look for 1266 // ivars. But if we don't find anything else, and there's an 1267 // ivar, that's an error. 1268 bool IsClassMethod = getCurMethodDecl()->isClassMethod(); 1269 1270 bool LookForIvars; 1271 if (Lookup.empty()) 1272 LookForIvars = true; 1273 else if (IsClassMethod) 1274 LookForIvars = false; 1275 else 1276 LookForIvars = (Lookup.isSingleResult() && 1277 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1278 ObjCInterfaceDecl *IFace = 0; 1279 if (LookForIvars) { 1280 IFace = getCurMethodDecl()->getClassInterface(); 1281 ObjCInterfaceDecl *ClassDeclared; 1282 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1283 // Diagnose using an ivar in a class method. 1284 if (IsClassMethod) 1285 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1286 << IV->getDeclName()); 1287 1288 // If we're referencing an invalid decl, just return this as a silent 1289 // error node. The error diagnostic was already emitted on the decl. 1290 if (IV->isInvalidDecl()) 1291 return ExprError(); 1292 1293 // Check if referencing a field with __attribute__((deprecated)). 1294 if (DiagnoseUseOfDecl(IV, Loc)) 1295 return ExprError(); 1296 1297 // Diagnose the use of an ivar outside of the declaring class. 1298 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1299 ClassDeclared != IFace) 1300 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1301 1302 // FIXME: This should use a new expr for a direct reference, don't 1303 // turn this into Self->ivar, just return a BareIVarExpr or something. 1304 IdentifierInfo &II = Context.Idents.get("self"); 1305 UnqualifiedId SelfName; 1306 SelfName.setIdentifier(&II, SourceLocation()); 1307 CXXScopeSpec SelfScopeSpec; 1308 OwningExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1309 SelfName, false, false); 1310 MarkDeclarationReferenced(Loc, IV); 1311 return Owned(new (Context) 1312 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1313 SelfExpr.takeAs<Expr>(), true, true)); 1314 } 1315 } else if (getCurMethodDecl()->isInstanceMethod()) { 1316 // We should warn if a local variable hides an ivar. 1317 ObjCInterfaceDecl *IFace = getCurMethodDecl()->getClassInterface(); 1318 ObjCInterfaceDecl *ClassDeclared; 1319 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1320 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1321 IFace == ClassDeclared) 1322 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1323 } 1324 } 1325 1326 // Needed to implement property "super.method" notation. 1327 if (Lookup.empty() && II->isStr("super")) { 1328 QualType T; 1329 1330 if (getCurMethodDecl()->isInstanceMethod()) 1331 T = Context.getObjCObjectPointerType(Context.getObjCInterfaceType( 1332 getCurMethodDecl()->getClassInterface())); 1333 else 1334 T = Context.getObjCClassType(); 1335 return Owned(new (Context) ObjCSuperExpr(Loc, T)); 1336 } 1337 if (Lookup.empty() && II && AllowBuiltinCreation) { 1338 // FIXME. Consolidate this with similar code in LookupName. 1339 if (unsigned BuiltinID = II->getBuiltinID()) { 1340 if (!(getLangOptions().CPlusPlus && 1341 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1342 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1343 S, Lookup.isForRedeclaration(), 1344 Lookup.getNameLoc()); 1345 if (D) Lookup.addDecl(D); 1346 } 1347 } 1348 } 1349 if (LangOpts.ObjCNonFragileABI2 && LookForIvars && Lookup.empty()) { 1350 ObjCIvarDecl *Ivar = SynthesizeNewPropertyIvar(IFace, II); 1351 if (Ivar) 1352 return LookupInObjCMethod(Lookup, S, II, AllowBuiltinCreation); 1353 } 1354 // Sentinel value saying that we didn't do anything special. 1355 return Owned((Expr*) 0); 1356} 1357 1358/// \brief Cast a base object to a member's actual type. 1359/// 1360/// Logically this happens in three phases: 1361/// 1362/// * First we cast from the base type to the naming class. 1363/// The naming class is the class into which we were looking 1364/// when we found the member; it's the qualifier type if a 1365/// qualifier was provided, and otherwise it's the base type. 1366/// 1367/// * Next we cast from the naming class to the declaring class. 1368/// If the member we found was brought into a class's scope by 1369/// a using declaration, this is that class; otherwise it's 1370/// the class declaring the member. 1371/// 1372/// * Finally we cast from the declaring class to the "true" 1373/// declaring class of the member. This conversion does not 1374/// obey access control. 1375bool 1376Sema::PerformObjectMemberConversion(Expr *&From, 1377 NestedNameSpecifier *Qualifier, 1378 NamedDecl *FoundDecl, 1379 NamedDecl *Member) { 1380 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1381 if (!RD) 1382 return false; 1383 1384 QualType DestRecordType; 1385 QualType DestType; 1386 QualType FromRecordType; 1387 QualType FromType = From->getType(); 1388 bool PointerConversions = false; 1389 if (isa<FieldDecl>(Member)) { 1390 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1391 1392 if (FromType->getAs<PointerType>()) { 1393 DestType = Context.getPointerType(DestRecordType); 1394 FromRecordType = FromType->getPointeeType(); 1395 PointerConversions = true; 1396 } else { 1397 DestType = DestRecordType; 1398 FromRecordType = FromType; 1399 } 1400 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1401 if (Method->isStatic()) 1402 return false; 1403 1404 DestType = Method->getThisType(Context); 1405 DestRecordType = DestType->getPointeeType(); 1406 1407 if (FromType->getAs<PointerType>()) { 1408 FromRecordType = FromType->getPointeeType(); 1409 PointerConversions = true; 1410 } else { 1411 FromRecordType = FromType; 1412 DestType = DestRecordType; 1413 } 1414 } else { 1415 // No conversion necessary. 1416 return false; 1417 } 1418 1419 if (DestType->isDependentType() || FromType->isDependentType()) 1420 return false; 1421 1422 // If the unqualified types are the same, no conversion is necessary. 1423 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1424 return false; 1425 1426 SourceRange FromRange = From->getSourceRange(); 1427 SourceLocation FromLoc = FromRange.getBegin(); 1428 1429 // C++ [class.member.lookup]p8: 1430 // [...] Ambiguities can often be resolved by qualifying a name with its 1431 // class name. 1432 // 1433 // If the member was a qualified name and the qualified referred to a 1434 // specific base subobject type, we'll cast to that intermediate type 1435 // first and then to the object in which the member is declared. That allows 1436 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1437 // 1438 // class Base { public: int x; }; 1439 // class Derived1 : public Base { }; 1440 // class Derived2 : public Base { }; 1441 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1442 // 1443 // void VeryDerived::f() { 1444 // x = 17; // error: ambiguous base subobjects 1445 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1446 // } 1447 if (Qualifier) { 1448 QualType QType = QualType(Qualifier->getAsType(), 0); 1449 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1450 assert(QType->isRecordType() && "lookup done with non-record type"); 1451 1452 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1453 1454 // In C++98, the qualifier type doesn't actually have to be a base 1455 // type of the object type, in which case we just ignore it. 1456 // Otherwise build the appropriate casts. 1457 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1458 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1459 FromLoc, FromRange)) 1460 return true; 1461 1462 if (PointerConversions) 1463 QType = Context.getPointerType(QType); 1464 ImpCastExprToType(From, QType, CastExpr::CK_UncheckedDerivedToBase, 1465 /*isLvalue*/ !PointerConversions); 1466 1467 FromType = QType; 1468 FromRecordType = QRecordType; 1469 1470 // If the qualifier type was the same as the destination type, 1471 // we're done. 1472 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1473 return false; 1474 } 1475 } 1476 1477 bool IgnoreAccess = false; 1478 1479 // If we actually found the member through a using declaration, cast 1480 // down to the using declaration's type. 1481 // 1482 // Pointer equality is fine here because only one declaration of a 1483 // class ever has member declarations. 1484 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1485 assert(isa<UsingShadowDecl>(FoundDecl)); 1486 QualType URecordType = Context.getTypeDeclType( 1487 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1488 1489 // We only need to do this if the naming-class to declaring-class 1490 // conversion is non-trivial. 1491 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1492 assert(IsDerivedFrom(FromRecordType, URecordType)); 1493 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1494 FromLoc, FromRange)) 1495 return true; 1496 1497 QualType UType = URecordType; 1498 if (PointerConversions) 1499 UType = Context.getPointerType(UType); 1500 ImpCastExprToType(From, UType, CastExpr::CK_UncheckedDerivedToBase, 1501 /*isLvalue*/ !PointerConversions); 1502 FromType = UType; 1503 FromRecordType = URecordType; 1504 } 1505 1506 // We don't do access control for the conversion from the 1507 // declaring class to the true declaring class. 1508 IgnoreAccess = true; 1509 } 1510 1511 if (CheckDerivedToBaseConversion(FromRecordType, 1512 DestRecordType, 1513 FromLoc, 1514 FromRange, 1515 IgnoreAccess)) 1516 return true; 1517 1518 ImpCastExprToType(From, DestType, CastExpr::CK_UncheckedDerivedToBase, 1519 /*isLvalue=*/ !PointerConversions); 1520 return false; 1521} 1522 1523/// \brief Build a MemberExpr AST node. 1524static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1525 const CXXScopeSpec &SS, ValueDecl *Member, 1526 NamedDecl *FoundDecl, SourceLocation Loc, 1527 QualType Ty, 1528 const TemplateArgumentListInfo *TemplateArgs = 0) { 1529 NestedNameSpecifier *Qualifier = 0; 1530 SourceRange QualifierRange; 1531 if (SS.isSet()) { 1532 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1533 QualifierRange = SS.getRange(); 1534 } 1535 1536 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1537 Member, FoundDecl, Loc, TemplateArgs, Ty); 1538} 1539 1540/// Builds an implicit member access expression. The current context 1541/// is known to be an instance method, and the given unqualified lookup 1542/// set is known to contain only instance members, at least one of which 1543/// is from an appropriate type. 1544Sema::OwningExprResult 1545Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1546 LookupResult &R, 1547 const TemplateArgumentListInfo *TemplateArgs, 1548 bool IsKnownInstance) { 1549 assert(!R.empty() && !R.isAmbiguous()); 1550 1551 SourceLocation Loc = R.getNameLoc(); 1552 1553 // We may have found a field within an anonymous union or struct 1554 // (C++ [class.union]). 1555 // FIXME: This needs to happen post-isImplicitMemberReference? 1556 // FIXME: template-ids inside anonymous structs? 1557 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1558 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1559 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1560 1561 // If this is known to be an instance access, go ahead and build a 1562 // 'this' expression now. 1563 QualType ThisType = cast<CXXMethodDecl>(CurContext)->getThisType(Context); 1564 Expr *This = 0; // null signifies implicit access 1565 if (IsKnownInstance) { 1566 SourceLocation Loc = R.getNameLoc(); 1567 if (SS.getRange().isValid()) 1568 Loc = SS.getRange().getBegin(); 1569 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1570 } 1571 1572 return BuildMemberReferenceExpr(ExprArg(*this, This), ThisType, 1573 /*OpLoc*/ SourceLocation(), 1574 /*IsArrow*/ true, 1575 SS, 1576 /*FirstQualifierInScope*/ 0, 1577 R, TemplateArgs); 1578} 1579 1580bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1581 const LookupResult &R, 1582 bool HasTrailingLParen) { 1583 // Only when used directly as the postfix-expression of a call. 1584 if (!HasTrailingLParen) 1585 return false; 1586 1587 // Never if a scope specifier was provided. 1588 if (SS.isSet()) 1589 return false; 1590 1591 // Only in C++ or ObjC++. 1592 if (!getLangOptions().CPlusPlus) 1593 return false; 1594 1595 // Turn off ADL when we find certain kinds of declarations during 1596 // normal lookup: 1597 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1598 NamedDecl *D = *I; 1599 1600 // C++0x [basic.lookup.argdep]p3: 1601 // -- a declaration of a class member 1602 // Since using decls preserve this property, we check this on the 1603 // original decl. 1604 if (D->isCXXClassMember()) 1605 return false; 1606 1607 // C++0x [basic.lookup.argdep]p3: 1608 // -- a block-scope function declaration that is not a 1609 // using-declaration 1610 // NOTE: we also trigger this for function templates (in fact, we 1611 // don't check the decl type at all, since all other decl types 1612 // turn off ADL anyway). 1613 if (isa<UsingShadowDecl>(D)) 1614 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1615 else if (D->getDeclContext()->isFunctionOrMethod()) 1616 return false; 1617 1618 // C++0x [basic.lookup.argdep]p3: 1619 // -- a declaration that is neither a function or a function 1620 // template 1621 // And also for builtin functions. 1622 if (isa<FunctionDecl>(D)) { 1623 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1624 1625 // But also builtin functions. 1626 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1627 return false; 1628 } else if (!isa<FunctionTemplateDecl>(D)) 1629 return false; 1630 } 1631 1632 return true; 1633} 1634 1635 1636/// Diagnoses obvious problems with the use of the given declaration 1637/// as an expression. This is only actually called for lookups that 1638/// were not overloaded, and it doesn't promise that the declaration 1639/// will in fact be used. 1640static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1641 if (isa<TypedefDecl>(D)) { 1642 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1643 return true; 1644 } 1645 1646 if (isa<ObjCInterfaceDecl>(D)) { 1647 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1648 return true; 1649 } 1650 1651 if (isa<NamespaceDecl>(D)) { 1652 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1653 return true; 1654 } 1655 1656 return false; 1657} 1658 1659Sema::OwningExprResult 1660Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1661 LookupResult &R, 1662 bool NeedsADL) { 1663 // If this is a single, fully-resolved result and we don't need ADL, 1664 // just build an ordinary singleton decl ref. 1665 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1666 return BuildDeclarationNameExpr(SS, R.getNameLoc(), R.getFoundDecl()); 1667 1668 // We only need to check the declaration if there's exactly one 1669 // result, because in the overloaded case the results can only be 1670 // functions and function templates. 1671 if (R.isSingleResult() && 1672 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1673 return ExprError(); 1674 1675 // Otherwise, just build an unresolved lookup expression. Suppress 1676 // any lookup-related diagnostics; we'll hash these out later, when 1677 // we've picked a target. 1678 R.suppressDiagnostics(); 1679 1680 bool Dependent 1681 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1682 UnresolvedLookupExpr *ULE 1683 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1684 (NestedNameSpecifier*) SS.getScopeRep(), 1685 SS.getRange(), 1686 R.getLookupName(), R.getNameLoc(), 1687 NeedsADL, R.isOverloadedResult()); 1688 ULE->addDecls(R.begin(), R.end()); 1689 1690 return Owned(ULE); 1691} 1692 1693 1694/// \brief Complete semantic analysis for a reference to the given declaration. 1695Sema::OwningExprResult 1696Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1697 SourceLocation Loc, NamedDecl *D) { 1698 assert(D && "Cannot refer to a NULL declaration"); 1699 assert(!isa<FunctionTemplateDecl>(D) && 1700 "Cannot refer unambiguously to a function template"); 1701 1702 if (CheckDeclInExpr(*this, Loc, D)) 1703 return ExprError(); 1704 1705 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1706 // Specifically diagnose references to class templates that are missing 1707 // a template argument list. 1708 Diag(Loc, diag::err_template_decl_ref) 1709 << Template << SS.getRange(); 1710 Diag(Template->getLocation(), diag::note_template_decl_here); 1711 return ExprError(); 1712 } 1713 1714 // Make sure that we're referring to a value. 1715 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1716 if (!VD) { 1717 Diag(Loc, diag::err_ref_non_value) 1718 << D << SS.getRange(); 1719 Diag(D->getLocation(), diag::note_declared_at); 1720 return ExprError(); 1721 } 1722 1723 // Check whether this declaration can be used. Note that we suppress 1724 // this check when we're going to perform argument-dependent lookup 1725 // on this function name, because this might not be the function 1726 // that overload resolution actually selects. 1727 if (DiagnoseUseOfDecl(VD, Loc)) 1728 return ExprError(); 1729 1730 // Only create DeclRefExpr's for valid Decl's. 1731 if (VD->isInvalidDecl()) 1732 return ExprError(); 1733 1734 // If the identifier reference is inside a block, and it refers to a value 1735 // that is outside the block, create a BlockDeclRefExpr instead of a 1736 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1737 // the block is formed. 1738 // 1739 // We do not do this for things like enum constants, global variables, etc, 1740 // as they do not get snapshotted. 1741 // 1742 if (getCurBlock() && 1743 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1744 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1745 Diag(Loc, diag::err_ref_vm_type); 1746 Diag(D->getLocation(), diag::note_declared_at); 1747 return ExprError(); 1748 } 1749 1750 if (VD->getType()->isArrayType()) { 1751 Diag(Loc, diag::err_ref_array_type); 1752 Diag(D->getLocation(), diag::note_declared_at); 1753 return ExprError(); 1754 } 1755 1756 MarkDeclarationReferenced(Loc, VD); 1757 QualType ExprTy = VD->getType().getNonReferenceType(); 1758 // The BlocksAttr indicates the variable is bound by-reference. 1759 if (VD->getAttr<BlocksAttr>()) 1760 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1761 // This is to record that a 'const' was actually synthesize and added. 1762 bool constAdded = !ExprTy.isConstQualified(); 1763 // Variable will be bound by-copy, make it const within the closure. 1764 1765 ExprTy.addConst(); 1766 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, false, 1767 constAdded)); 1768 } 1769 // If this reference is not in a block or if the referenced variable is 1770 // within the block, create a normal DeclRefExpr. 1771 1772 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), Loc, &SS); 1773} 1774 1775Sema::OwningExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1776 tok::TokenKind Kind) { 1777 PredefinedExpr::IdentType IT; 1778 1779 switch (Kind) { 1780 default: assert(0 && "Unknown simple primary expr!"); 1781 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1782 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1783 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1784 } 1785 1786 // Pre-defined identifiers are of type char[x], where x is the length of the 1787 // string. 1788 1789 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1790 if (!currentDecl) { 1791 Diag(Loc, diag::ext_predef_outside_function); 1792 currentDecl = Context.getTranslationUnitDecl(); 1793 } 1794 1795 QualType ResTy; 1796 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1797 ResTy = Context.DependentTy; 1798 } else { 1799 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1800 1801 llvm::APInt LengthI(32, Length + 1); 1802 ResTy = Context.CharTy.withConst(); 1803 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1804 } 1805 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1806} 1807 1808Sema::OwningExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1809 llvm::SmallString<16> CharBuffer; 1810 bool Invalid = false; 1811 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1812 if (Invalid) 1813 return ExprError(); 1814 1815 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1816 PP); 1817 if (Literal.hadError()) 1818 return ExprError(); 1819 1820 QualType Ty; 1821 if (!getLangOptions().CPlusPlus) 1822 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1823 else if (Literal.isWide()) 1824 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1825 else if (Literal.isMultiChar()) 1826 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1827 else 1828 Ty = Context.CharTy; // 'x' -> char in C++ 1829 1830 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1831 Literal.isWide(), 1832 Ty, Tok.getLocation())); 1833} 1834 1835Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1836 // Fast path for a single digit (which is quite common). A single digit 1837 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1838 if (Tok.getLength() == 1) { 1839 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1840 unsigned IntSize = Context.Target.getIntWidth(); 1841 return Owned(new (Context) IntegerLiteral(llvm::APInt(IntSize, Val-'0'), 1842 Context.IntTy, Tok.getLocation())); 1843 } 1844 1845 llvm::SmallString<512> IntegerBuffer; 1846 // Add padding so that NumericLiteralParser can overread by one character. 1847 IntegerBuffer.resize(Tok.getLength()+1); 1848 const char *ThisTokBegin = &IntegerBuffer[0]; 1849 1850 // Get the spelling of the token, which eliminates trigraphs, etc. 1851 bool Invalid = false; 1852 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1853 if (Invalid) 1854 return ExprError(); 1855 1856 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1857 Tok.getLocation(), PP); 1858 if (Literal.hadError) 1859 return ExprError(); 1860 1861 Expr *Res; 1862 1863 if (Literal.isFloatingLiteral()) { 1864 QualType Ty; 1865 if (Literal.isFloat) 1866 Ty = Context.FloatTy; 1867 else if (!Literal.isLong) 1868 Ty = Context.DoubleTy; 1869 else 1870 Ty = Context.LongDoubleTy; 1871 1872 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1873 1874 using llvm::APFloat; 1875 APFloat Val(Format); 1876 1877 APFloat::opStatus result = Literal.GetFloatValue(Val); 1878 1879 // Overflow is always an error, but underflow is only an error if 1880 // we underflowed to zero (APFloat reports denormals as underflow). 1881 if ((result & APFloat::opOverflow) || 1882 ((result & APFloat::opUnderflow) && Val.isZero())) { 1883 unsigned diagnostic; 1884 llvm::SmallString<20> buffer; 1885 if (result & APFloat::opOverflow) { 1886 diagnostic = diag::warn_float_overflow; 1887 APFloat::getLargest(Format).toString(buffer); 1888 } else { 1889 diagnostic = diag::warn_float_underflow; 1890 APFloat::getSmallest(Format).toString(buffer); 1891 } 1892 1893 Diag(Tok.getLocation(), diagnostic) 1894 << Ty 1895 << llvm::StringRef(buffer.data(), buffer.size()); 1896 } 1897 1898 bool isExact = (result == APFloat::opOK); 1899 Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation()); 1900 1901 } else if (!Literal.isIntegerLiteral()) { 1902 return ExprError(); 1903 } else { 1904 QualType Ty; 1905 1906 // long long is a C99 feature. 1907 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 1908 Literal.isLongLong) 1909 Diag(Tok.getLocation(), diag::ext_longlong); 1910 1911 // Get the value in the widest-possible width. 1912 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 1913 1914 if (Literal.GetIntegerValue(ResultVal)) { 1915 // If this value didn't fit into uintmax_t, warn and force to ull. 1916 Diag(Tok.getLocation(), diag::warn_integer_too_large); 1917 Ty = Context.UnsignedLongLongTy; 1918 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 1919 "long long is not intmax_t?"); 1920 } else { 1921 // If this value fits into a ULL, try to figure out what else it fits into 1922 // according to the rules of C99 6.4.4.1p5. 1923 1924 // Octal, Hexadecimal, and integers with a U suffix are allowed to 1925 // be an unsigned int. 1926 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 1927 1928 // Check from smallest to largest, picking the smallest type we can. 1929 unsigned Width = 0; 1930 if (!Literal.isLong && !Literal.isLongLong) { 1931 // Are int/unsigned possibilities? 1932 unsigned IntSize = Context.Target.getIntWidth(); 1933 1934 // Does it fit in a unsigned int? 1935 if (ResultVal.isIntN(IntSize)) { 1936 // Does it fit in a signed int? 1937 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 1938 Ty = Context.IntTy; 1939 else if (AllowUnsigned) 1940 Ty = Context.UnsignedIntTy; 1941 Width = IntSize; 1942 } 1943 } 1944 1945 // Are long/unsigned long possibilities? 1946 if (Ty.isNull() && !Literal.isLongLong) { 1947 unsigned LongSize = Context.Target.getLongWidth(); 1948 1949 // Does it fit in a unsigned long? 1950 if (ResultVal.isIntN(LongSize)) { 1951 // Does it fit in a signed long? 1952 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 1953 Ty = Context.LongTy; 1954 else if (AllowUnsigned) 1955 Ty = Context.UnsignedLongTy; 1956 Width = LongSize; 1957 } 1958 } 1959 1960 // Finally, check long long if needed. 1961 if (Ty.isNull()) { 1962 unsigned LongLongSize = Context.Target.getLongLongWidth(); 1963 1964 // Does it fit in a unsigned long long? 1965 if (ResultVal.isIntN(LongLongSize)) { 1966 // Does it fit in a signed long long? 1967 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 1968 Ty = Context.LongLongTy; 1969 else if (AllowUnsigned) 1970 Ty = Context.UnsignedLongLongTy; 1971 Width = LongLongSize; 1972 } 1973 } 1974 1975 // If we still couldn't decide a type, we probably have something that 1976 // does not fit in a signed long long, but has no U suffix. 1977 if (Ty.isNull()) { 1978 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 1979 Ty = Context.UnsignedLongLongTy; 1980 Width = Context.Target.getLongLongWidth(); 1981 } 1982 1983 if (ResultVal.getBitWidth() != Width) 1984 ResultVal.trunc(Width); 1985 } 1986 Res = new (Context) IntegerLiteral(ResultVal, Ty, Tok.getLocation()); 1987 } 1988 1989 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 1990 if (Literal.isImaginary) 1991 Res = new (Context) ImaginaryLiteral(Res, 1992 Context.getComplexType(Res->getType())); 1993 1994 return Owned(Res); 1995} 1996 1997Action::OwningExprResult Sema::ActOnParenExpr(SourceLocation L, 1998 SourceLocation R, ExprArg Val) { 1999 Expr *E = Val.takeAs<Expr>(); 2000 assert((E != 0) && "ActOnParenExpr() missing expr"); 2001 return Owned(new (Context) ParenExpr(L, R, E)); 2002} 2003 2004/// The UsualUnaryConversions() function is *not* called by this routine. 2005/// See C99 6.3.2.1p[2-4] for more details. 2006bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2007 SourceLocation OpLoc, 2008 const SourceRange &ExprRange, 2009 bool isSizeof) { 2010 if (exprType->isDependentType()) 2011 return false; 2012 2013 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2014 // the result is the size of the referenced type." 2015 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2016 // result shall be the alignment of the referenced type." 2017 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2018 exprType = Ref->getPointeeType(); 2019 2020 // C99 6.5.3.4p1: 2021 if (exprType->isFunctionType()) { 2022 // alignof(function) is allowed as an extension. 2023 if (isSizeof) 2024 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2025 return false; 2026 } 2027 2028 // Allow sizeof(void)/alignof(void) as an extension. 2029 if (exprType->isVoidType()) { 2030 Diag(OpLoc, diag::ext_sizeof_void_type) 2031 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2032 return false; 2033 } 2034 2035 if (RequireCompleteType(OpLoc, exprType, 2036 PDiag(diag::err_sizeof_alignof_incomplete_type) 2037 << int(!isSizeof) << ExprRange)) 2038 return true; 2039 2040 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2041 if (LangOpts.ObjCNonFragileABI && exprType->isObjCInterfaceType()) { 2042 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2043 << exprType << isSizeof << ExprRange; 2044 return true; 2045 } 2046 2047 return false; 2048} 2049 2050bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2051 const SourceRange &ExprRange) { 2052 E = E->IgnoreParens(); 2053 2054 // alignof decl is always ok. 2055 if (isa<DeclRefExpr>(E)) 2056 return false; 2057 2058 // Cannot know anything else if the expression is dependent. 2059 if (E->isTypeDependent()) 2060 return false; 2061 2062 if (E->getBitField()) { 2063 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2064 return true; 2065 } 2066 2067 // Alignment of a field access is always okay, so long as it isn't a 2068 // bit-field. 2069 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2070 if (isa<FieldDecl>(ME->getMemberDecl())) 2071 return false; 2072 2073 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2074} 2075 2076/// \brief Build a sizeof or alignof expression given a type operand. 2077Action::OwningExprResult 2078Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2079 SourceLocation OpLoc, 2080 bool isSizeOf, SourceRange R) { 2081 if (!TInfo) 2082 return ExprError(); 2083 2084 QualType T = TInfo->getType(); 2085 2086 if (!T->isDependentType() && 2087 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2088 return ExprError(); 2089 2090 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2091 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2092 Context.getSizeType(), OpLoc, 2093 R.getEnd())); 2094} 2095 2096/// \brief Build a sizeof or alignof expression given an expression 2097/// operand. 2098Action::OwningExprResult 2099Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2100 bool isSizeOf, SourceRange R) { 2101 // Verify that the operand is valid. 2102 bool isInvalid = false; 2103 if (E->isTypeDependent()) { 2104 // Delay type-checking for type-dependent expressions. 2105 } else if (!isSizeOf) { 2106 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2107 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2108 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2109 isInvalid = true; 2110 } else { 2111 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2112 } 2113 2114 if (isInvalid) 2115 return ExprError(); 2116 2117 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2118 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2119 Context.getSizeType(), OpLoc, 2120 R.getEnd())); 2121} 2122 2123/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2124/// the same for @c alignof and @c __alignof 2125/// Note that the ArgRange is invalid if isType is false. 2126Action::OwningExprResult 2127Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2128 void *TyOrEx, const SourceRange &ArgRange) { 2129 // If error parsing type, ignore. 2130 if (TyOrEx == 0) return ExprError(); 2131 2132 if (isType) { 2133 TypeSourceInfo *TInfo; 2134 (void) GetTypeFromParser(TyOrEx, &TInfo); 2135 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2136 } 2137 2138 Expr *ArgEx = (Expr *)TyOrEx; 2139 Action::OwningExprResult Result 2140 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2141 2142 if (Result.isInvalid()) 2143 DeleteExpr(ArgEx); 2144 2145 return move(Result); 2146} 2147 2148QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2149 if (V->isTypeDependent()) 2150 return Context.DependentTy; 2151 2152 // These operators return the element type of a complex type. 2153 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2154 return CT->getElementType(); 2155 2156 // Otherwise they pass through real integer and floating point types here. 2157 if (V->getType()->isArithmeticType()) 2158 return V->getType(); 2159 2160 // Reject anything else. 2161 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2162 << (isReal ? "__real" : "__imag"); 2163 return QualType(); 2164} 2165 2166 2167 2168Action::OwningExprResult 2169Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2170 tok::TokenKind Kind, ExprArg Input) { 2171 UnaryOperator::Opcode Opc; 2172 switch (Kind) { 2173 default: assert(0 && "Unknown unary op!"); 2174 case tok::plusplus: Opc = UnaryOperator::PostInc; break; 2175 case tok::minusminus: Opc = UnaryOperator::PostDec; break; 2176 } 2177 2178 return BuildUnaryOp(S, OpLoc, Opc, move(Input)); 2179} 2180 2181Action::OwningExprResult 2182Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc, 2183 ExprArg Idx, SourceLocation RLoc) { 2184 // Since this might be a postfix expression, get rid of ParenListExprs. 2185 Base = MaybeConvertParenListExprToParenExpr(S, move(Base)); 2186 2187 Expr *LHSExp = static_cast<Expr*>(Base.get()), 2188 *RHSExp = static_cast<Expr*>(Idx.get()); 2189 2190 if (getLangOptions().CPlusPlus && 2191 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2192 Base.release(); 2193 Idx.release(); 2194 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2195 Context.DependentTy, RLoc)); 2196 } 2197 2198 if (getLangOptions().CPlusPlus && 2199 (LHSExp->getType()->isRecordType() || 2200 LHSExp->getType()->isEnumeralType() || 2201 RHSExp->getType()->isRecordType() || 2202 RHSExp->getType()->isEnumeralType())) { 2203 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, move(Base),move(Idx)); 2204 } 2205 2206 return CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 2207} 2208 2209 2210Action::OwningExprResult 2211Sema::CreateBuiltinArraySubscriptExpr(ExprArg Base, SourceLocation LLoc, 2212 ExprArg Idx, SourceLocation RLoc) { 2213 Expr *LHSExp = static_cast<Expr*>(Base.get()); 2214 Expr *RHSExp = static_cast<Expr*>(Idx.get()); 2215 2216 // Perform default conversions. 2217 if (!LHSExp->getType()->getAs<VectorType>()) 2218 DefaultFunctionArrayLvalueConversion(LHSExp); 2219 DefaultFunctionArrayLvalueConversion(RHSExp); 2220 2221 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2222 2223 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2224 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2225 // in the subscript position. As a result, we need to derive the array base 2226 // and index from the expression types. 2227 Expr *BaseExpr, *IndexExpr; 2228 QualType ResultType; 2229 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2230 BaseExpr = LHSExp; 2231 IndexExpr = RHSExp; 2232 ResultType = Context.DependentTy; 2233 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2234 BaseExpr = LHSExp; 2235 IndexExpr = RHSExp; 2236 ResultType = PTy->getPointeeType(); 2237 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2238 // Handle the uncommon case of "123[Ptr]". 2239 BaseExpr = RHSExp; 2240 IndexExpr = LHSExp; 2241 ResultType = PTy->getPointeeType(); 2242 } else if (const ObjCObjectPointerType *PTy = 2243 LHSTy->getAs<ObjCObjectPointerType>()) { 2244 BaseExpr = LHSExp; 2245 IndexExpr = RHSExp; 2246 ResultType = PTy->getPointeeType(); 2247 } else if (const ObjCObjectPointerType *PTy = 2248 RHSTy->getAs<ObjCObjectPointerType>()) { 2249 // Handle the uncommon case of "123[Ptr]". 2250 BaseExpr = RHSExp; 2251 IndexExpr = LHSExp; 2252 ResultType = PTy->getPointeeType(); 2253 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2254 BaseExpr = LHSExp; // vectors: V[123] 2255 IndexExpr = RHSExp; 2256 2257 // FIXME: need to deal with const... 2258 ResultType = VTy->getElementType(); 2259 } else if (LHSTy->isArrayType()) { 2260 // If we see an array that wasn't promoted by 2261 // DefaultFunctionArrayLvalueConversion, it must be an array that 2262 // wasn't promoted because of the C90 rule that doesn't 2263 // allow promoting non-lvalue arrays. Warn, then 2264 // force the promotion here. 2265 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2266 LHSExp->getSourceRange(); 2267 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2268 CastExpr::CK_ArrayToPointerDecay); 2269 LHSTy = LHSExp->getType(); 2270 2271 BaseExpr = LHSExp; 2272 IndexExpr = RHSExp; 2273 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2274 } else if (RHSTy->isArrayType()) { 2275 // Same as previous, except for 123[f().a] case 2276 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2277 RHSExp->getSourceRange(); 2278 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2279 CastExpr::CK_ArrayToPointerDecay); 2280 RHSTy = RHSExp->getType(); 2281 2282 BaseExpr = RHSExp; 2283 IndexExpr = LHSExp; 2284 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2285 } else { 2286 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2287 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2288 } 2289 // C99 6.5.2.1p1 2290 if (!(IndexExpr->getType()->isIntegerType() && 2291 IndexExpr->getType()->isScalarType()) && !IndexExpr->isTypeDependent()) 2292 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2293 << IndexExpr->getSourceRange()); 2294 2295 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2296 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2297 && !IndexExpr->isTypeDependent()) 2298 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2299 2300 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2301 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2302 // type. Note that Functions are not objects, and that (in C99 parlance) 2303 // incomplete types are not object types. 2304 if (ResultType->isFunctionType()) { 2305 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2306 << ResultType << BaseExpr->getSourceRange(); 2307 return ExprError(); 2308 } 2309 2310 if (!ResultType->isDependentType() && 2311 RequireCompleteType(LLoc, ResultType, 2312 PDiag(diag::err_subscript_incomplete_type) 2313 << BaseExpr->getSourceRange())) 2314 return ExprError(); 2315 2316 // Diagnose bad cases where we step over interface counts. 2317 if (ResultType->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 2318 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2319 << ResultType << BaseExpr->getSourceRange(); 2320 return ExprError(); 2321 } 2322 2323 Base.release(); 2324 Idx.release(); 2325 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2326 ResultType, RLoc)); 2327} 2328 2329QualType Sema:: 2330CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2331 const IdentifierInfo *CompName, 2332 SourceLocation CompLoc) { 2333 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2334 // see FIXME there. 2335 // 2336 // FIXME: This logic can be greatly simplified by splitting it along 2337 // halving/not halving and reworking the component checking. 2338 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2339 2340 // The vector accessor can't exceed the number of elements. 2341 const char *compStr = CompName->getNameStart(); 2342 2343 // This flag determines whether or not the component is one of the four 2344 // special names that indicate a subset of exactly half the elements are 2345 // to be selected. 2346 bool HalvingSwizzle = false; 2347 2348 // This flag determines whether or not CompName has an 's' char prefix, 2349 // indicating that it is a string of hex values to be used as vector indices. 2350 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2351 2352 // Check that we've found one of the special components, or that the component 2353 // names must come from the same set. 2354 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2355 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2356 HalvingSwizzle = true; 2357 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2358 do 2359 compStr++; 2360 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2361 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2362 do 2363 compStr++; 2364 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2365 } 2366 2367 if (!HalvingSwizzle && *compStr) { 2368 // We didn't get to the end of the string. This means the component names 2369 // didn't come from the same set *or* we encountered an illegal name. 2370 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2371 << std::string(compStr,compStr+1) << SourceRange(CompLoc); 2372 return QualType(); 2373 } 2374 2375 // Ensure no component accessor exceeds the width of the vector type it 2376 // operates on. 2377 if (!HalvingSwizzle) { 2378 compStr = CompName->getNameStart(); 2379 2380 if (HexSwizzle) 2381 compStr++; 2382 2383 while (*compStr) { 2384 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2385 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2386 << baseType << SourceRange(CompLoc); 2387 return QualType(); 2388 } 2389 } 2390 } 2391 2392 // The component accessor looks fine - now we need to compute the actual type. 2393 // The vector type is implied by the component accessor. For example, 2394 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2395 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2396 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2397 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2398 : CompName->getLength(); 2399 if (HexSwizzle) 2400 CompSize--; 2401 2402 if (CompSize == 1) 2403 return vecType->getElementType(); 2404 2405 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2406 // Now look up the TypeDefDecl from the vector type. Without this, 2407 // diagostics look bad. We want extended vector types to appear built-in. 2408 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2409 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2410 return Context.getTypedefType(ExtVectorDecls[i]); 2411 } 2412 return VT; // should never get here (a typedef type should always be found). 2413} 2414 2415static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2416 IdentifierInfo *Member, 2417 const Selector &Sel, 2418 ASTContext &Context) { 2419 2420 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2421 return PD; 2422 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2423 return OMD; 2424 2425 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2426 E = PDecl->protocol_end(); I != E; ++I) { 2427 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2428 Context)) 2429 return D; 2430 } 2431 return 0; 2432} 2433 2434static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2435 IdentifierInfo *Member, 2436 const Selector &Sel, 2437 ASTContext &Context) { 2438 // Check protocols on qualified interfaces. 2439 Decl *GDecl = 0; 2440 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2441 E = QIdTy->qual_end(); I != E; ++I) { 2442 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2443 GDecl = PD; 2444 break; 2445 } 2446 // Also must look for a getter name which uses property syntax. 2447 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2448 GDecl = OMD; 2449 break; 2450 } 2451 } 2452 if (!GDecl) { 2453 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2454 E = QIdTy->qual_end(); I != E; ++I) { 2455 // Search in the protocol-qualifier list of current protocol. 2456 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2457 if (GDecl) 2458 return GDecl; 2459 } 2460 } 2461 return GDecl; 2462} 2463 2464Sema::OwningExprResult 2465Sema::ActOnDependentMemberExpr(ExprArg Base, QualType BaseType, 2466 bool IsArrow, SourceLocation OpLoc, 2467 const CXXScopeSpec &SS, 2468 NamedDecl *FirstQualifierInScope, 2469 DeclarationName Name, SourceLocation NameLoc, 2470 const TemplateArgumentListInfo *TemplateArgs) { 2471 Expr *BaseExpr = Base.takeAs<Expr>(); 2472 2473 // Even in dependent contexts, try to diagnose base expressions with 2474 // obviously wrong types, e.g.: 2475 // 2476 // T* t; 2477 // t.f; 2478 // 2479 // In Obj-C++, however, the above expression is valid, since it could be 2480 // accessing the 'f' property if T is an Obj-C interface. The extra check 2481 // allows this, while still reporting an error if T is a struct pointer. 2482 if (!IsArrow) { 2483 const PointerType *PT = BaseType->getAs<PointerType>(); 2484 if (PT && (!getLangOptions().ObjC1 || 2485 PT->getPointeeType()->isRecordType())) { 2486 assert(BaseExpr && "cannot happen with implicit member accesses"); 2487 Diag(NameLoc, diag::err_typecheck_member_reference_struct_union) 2488 << BaseType << BaseExpr->getSourceRange(); 2489 return ExprError(); 2490 } 2491 } 2492 2493 assert(BaseType->isDependentType() || Name.isDependentName()); 2494 2495 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2496 // must have pointer type, and the accessed type is the pointee. 2497 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2498 IsArrow, OpLoc, 2499 static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 2500 SS.getRange(), 2501 FirstQualifierInScope, 2502 Name, NameLoc, 2503 TemplateArgs)); 2504} 2505 2506/// We know that the given qualified member reference points only to 2507/// declarations which do not belong to the static type of the base 2508/// expression. Diagnose the problem. 2509static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2510 Expr *BaseExpr, 2511 QualType BaseType, 2512 const CXXScopeSpec &SS, 2513 const LookupResult &R) { 2514 // If this is an implicit member access, use a different set of 2515 // diagnostics. 2516 if (!BaseExpr) 2517 return DiagnoseInstanceReference(SemaRef, SS, R); 2518 2519 // FIXME: this is an exceedingly lame diagnostic for some of the more 2520 // complicated cases here. 2521 DeclContext *DC = R.getRepresentativeDecl()->getDeclContext(); 2522 SemaRef.Diag(R.getNameLoc(), diag::err_not_direct_base_or_virtual) 2523 << SS.getRange() << DC << BaseType; 2524} 2525 2526// Check whether the declarations we found through a nested-name 2527// specifier in a member expression are actually members of the base 2528// type. The restriction here is: 2529// 2530// C++ [expr.ref]p2: 2531// ... In these cases, the id-expression shall name a 2532// member of the class or of one of its base classes. 2533// 2534// So it's perfectly legitimate for the nested-name specifier to name 2535// an unrelated class, and for us to find an overload set including 2536// decls from classes which are not superclasses, as long as the decl 2537// we actually pick through overload resolution is from a superclass. 2538bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2539 QualType BaseType, 2540 const CXXScopeSpec &SS, 2541 const LookupResult &R) { 2542 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2543 if (!BaseRT) { 2544 // We can't check this yet because the base type is still 2545 // dependent. 2546 assert(BaseType->isDependentType()); 2547 return false; 2548 } 2549 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2550 2551 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2552 // If this is an implicit member reference and we find a 2553 // non-instance member, it's not an error. 2554 if (!BaseExpr && !IsInstanceMember((*I)->getUnderlyingDecl())) 2555 return false; 2556 2557 // Note that we use the DC of the decl, not the underlying decl. 2558 CXXRecordDecl *RecordD = cast<CXXRecordDecl>((*I)->getDeclContext()); 2559 while (RecordD->isAnonymousStructOrUnion()) 2560 RecordD = cast<CXXRecordDecl>(RecordD->getParent()); 2561 2562 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2563 MemberRecord.insert(RecordD->getCanonicalDecl()); 2564 2565 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2566 return false; 2567 } 2568 2569 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2570 return true; 2571} 2572 2573static bool 2574LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2575 SourceRange BaseRange, const RecordType *RTy, 2576 SourceLocation OpLoc, const CXXScopeSpec &SS) { 2577 RecordDecl *RDecl = RTy->getDecl(); 2578 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2579 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2580 << BaseRange)) 2581 return true; 2582 2583 DeclContext *DC = RDecl; 2584 if (SS.isSet()) { 2585 // If the member name was a qualified-id, look into the 2586 // nested-name-specifier. 2587 DC = SemaRef.computeDeclContext(SS, false); 2588 2589 if (SemaRef.RequireCompleteDeclContext(SS)) { 2590 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2591 << SS.getRange() << DC; 2592 return true; 2593 } 2594 2595 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2596 2597 if (!isa<TypeDecl>(DC)) { 2598 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2599 << DC << SS.getRange(); 2600 return true; 2601 } 2602 } 2603 2604 // The record definition is complete, now look up the member. 2605 SemaRef.LookupQualifiedName(R, DC); 2606 2607 if (!R.empty()) 2608 return false; 2609 2610 // We didn't find anything with the given name, so try to correct 2611 // for typos. 2612 DeclarationName Name = R.getLookupName(); 2613 if (SemaRef.CorrectTypo(R, 0, &SS, DC) && 2614 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2615 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2616 << Name << DC << R.getLookupName() << SS.getRange() 2617 << CodeModificationHint::CreateReplacement(R.getNameLoc(), 2618 R.getLookupName().getAsString()); 2619 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2620 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2621 << ND->getDeclName(); 2622 return false; 2623 } else { 2624 R.clear(); 2625 } 2626 2627 return false; 2628} 2629 2630Sema::OwningExprResult 2631Sema::BuildMemberReferenceExpr(ExprArg BaseArg, QualType BaseType, 2632 SourceLocation OpLoc, bool IsArrow, 2633 const CXXScopeSpec &SS, 2634 NamedDecl *FirstQualifierInScope, 2635 DeclarationName Name, SourceLocation NameLoc, 2636 const TemplateArgumentListInfo *TemplateArgs) { 2637 Expr *Base = BaseArg.takeAs<Expr>(); 2638 2639 if (BaseType->isDependentType() || 2640 (SS.isSet() && isDependentScopeSpecifier(SS))) 2641 return ActOnDependentMemberExpr(ExprArg(*this, Base), BaseType, 2642 IsArrow, OpLoc, 2643 SS, FirstQualifierInScope, 2644 Name, NameLoc, 2645 TemplateArgs); 2646 2647 LookupResult R(*this, Name, NameLoc, LookupMemberName); 2648 2649 // Implicit member accesses. 2650 if (!Base) { 2651 QualType RecordTy = BaseType; 2652 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2653 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2654 RecordTy->getAs<RecordType>(), 2655 OpLoc, SS)) 2656 return ExprError(); 2657 2658 // Explicit member accesses. 2659 } else { 2660 OwningExprResult Result = 2661 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2662 SS, /*ObjCImpDecl*/ DeclPtrTy()); 2663 2664 if (Result.isInvalid()) { 2665 Owned(Base); 2666 return ExprError(); 2667 } 2668 2669 if (Result.get()) 2670 return move(Result); 2671 } 2672 2673 return BuildMemberReferenceExpr(ExprArg(*this, Base), BaseType, 2674 OpLoc, IsArrow, SS, FirstQualifierInScope, 2675 R, TemplateArgs); 2676} 2677 2678Sema::OwningExprResult 2679Sema::BuildMemberReferenceExpr(ExprArg Base, QualType BaseExprType, 2680 SourceLocation OpLoc, bool IsArrow, 2681 const CXXScopeSpec &SS, 2682 NamedDecl *FirstQualifierInScope, 2683 LookupResult &R, 2684 const TemplateArgumentListInfo *TemplateArgs) { 2685 Expr *BaseExpr = Base.takeAs<Expr>(); 2686 QualType BaseType = BaseExprType; 2687 if (IsArrow) { 2688 assert(BaseType->isPointerType()); 2689 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2690 } 2691 2692 NestedNameSpecifier *Qualifier = 2693 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 2694 DeclarationName MemberName = R.getLookupName(); 2695 SourceLocation MemberLoc = R.getNameLoc(); 2696 2697 if (R.isAmbiguous()) 2698 return ExprError(); 2699 2700 if (R.empty()) { 2701 // Rederive where we looked up. 2702 DeclContext *DC = (SS.isSet() 2703 ? computeDeclContext(SS, false) 2704 : BaseType->getAs<RecordType>()->getDecl()); 2705 2706 Diag(R.getNameLoc(), diag::err_no_member) 2707 << MemberName << DC 2708 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2709 return ExprError(); 2710 } 2711 2712 // Diagnose lookups that find only declarations from a non-base 2713 // type. This is possible for either qualified lookups (which may 2714 // have been qualified with an unrelated type) or implicit member 2715 // expressions (which were found with unqualified lookup and thus 2716 // may have come from an enclosing scope). Note that it's okay for 2717 // lookup to find declarations from a non-base type as long as those 2718 // aren't the ones picked by overload resolution. 2719 if ((SS.isSet() || !BaseExpr || 2720 (isa<CXXThisExpr>(BaseExpr) && 2721 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2722 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2723 return ExprError(); 2724 2725 // Construct an unresolved result if we in fact got an unresolved 2726 // result. 2727 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2728 bool Dependent = 2729 BaseExprType->isDependentType() || 2730 R.isUnresolvableResult() || 2731 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2732 2733 // Suppress any lookup-related diagnostics; we'll do these when we 2734 // pick a member. 2735 R.suppressDiagnostics(); 2736 2737 UnresolvedMemberExpr *MemExpr 2738 = UnresolvedMemberExpr::Create(Context, Dependent, 2739 R.isUnresolvableResult(), 2740 BaseExpr, BaseExprType, 2741 IsArrow, OpLoc, 2742 Qualifier, SS.getRange(), 2743 MemberName, MemberLoc, 2744 TemplateArgs); 2745 MemExpr->addDecls(R.begin(), R.end()); 2746 2747 return Owned(MemExpr); 2748 } 2749 2750 assert(R.isSingleResult()); 2751 NamedDecl *FoundDecl = *R.begin(); 2752 NamedDecl *MemberDecl = R.getFoundDecl(); 2753 2754 // FIXME: diagnose the presence of template arguments now. 2755 2756 // If the decl being referenced had an error, return an error for this 2757 // sub-expr without emitting another error, in order to avoid cascading 2758 // error cases. 2759 if (MemberDecl->isInvalidDecl()) 2760 return ExprError(); 2761 2762 // Handle the implicit-member-access case. 2763 if (!BaseExpr) { 2764 // If this is not an instance member, convert to a non-member access. 2765 if (!IsInstanceMember(MemberDecl)) 2766 return BuildDeclarationNameExpr(SS, R.getNameLoc(), MemberDecl); 2767 2768 SourceLocation Loc = R.getNameLoc(); 2769 if (SS.getRange().isValid()) 2770 Loc = SS.getRange().getBegin(); 2771 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2772 } 2773 2774 bool ShouldCheckUse = true; 2775 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2776 // Don't diagnose the use of a virtual member function unless it's 2777 // explicitly qualified. 2778 if (MD->isVirtual() && !SS.isSet()) 2779 ShouldCheckUse = false; 2780 } 2781 2782 // Check the use of this member. 2783 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2784 Owned(BaseExpr); 2785 return ExprError(); 2786 } 2787 2788 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2789 // We may have found a field within an anonymous union or struct 2790 // (C++ [class.union]). 2791 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2792 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2793 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2794 BaseExpr, OpLoc); 2795 2796 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2797 QualType MemberType = FD->getType(); 2798 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2799 MemberType = Ref->getPointeeType(); 2800 else { 2801 Qualifiers BaseQuals = BaseType.getQualifiers(); 2802 BaseQuals.removeObjCGCAttr(); 2803 if (FD->isMutable()) BaseQuals.removeConst(); 2804 2805 Qualifiers MemberQuals 2806 = Context.getCanonicalType(MemberType).getQualifiers(); 2807 2808 Qualifiers Combined = BaseQuals + MemberQuals; 2809 if (Combined != MemberQuals) 2810 MemberType = Context.getQualifiedType(MemberType, Combined); 2811 } 2812 2813 MarkDeclarationReferenced(MemberLoc, FD); 2814 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2815 return ExprError(); 2816 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2817 FD, FoundDecl, MemberLoc, MemberType)); 2818 } 2819 2820 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2821 MarkDeclarationReferenced(MemberLoc, Var); 2822 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2823 Var, FoundDecl, MemberLoc, 2824 Var->getType().getNonReferenceType())); 2825 } 2826 2827 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2828 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2829 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2830 MemberFn, FoundDecl, MemberLoc, 2831 MemberFn->getType())); 2832 } 2833 2834 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2835 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2836 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2837 Enum, FoundDecl, MemberLoc, Enum->getType())); 2838 } 2839 2840 Owned(BaseExpr); 2841 2842 if (isa<TypeDecl>(MemberDecl)) 2843 return ExprError(Diag(MemberLoc,diag::err_typecheck_member_reference_type) 2844 << MemberName << int(IsArrow)); 2845 2846 // We found a declaration kind that we didn't expect. This is a 2847 // generic error message that tells the user that she can't refer 2848 // to this member with '.' or '->'. 2849 return ExprError(Diag(MemberLoc, 2850 diag::err_typecheck_member_reference_unknown) 2851 << MemberName << int(IsArrow)); 2852} 2853 2854/// Look up the given member of the given non-type-dependent 2855/// expression. This can return in one of two ways: 2856/// * If it returns a sentinel null-but-valid result, the caller will 2857/// assume that lookup was performed and the results written into 2858/// the provided structure. It will take over from there. 2859/// * Otherwise, the returned expression will be produced in place of 2860/// an ordinary member expression. 2861/// 2862/// The ObjCImpDecl bit is a gross hack that will need to be properly 2863/// fixed for ObjC++. 2864Sema::OwningExprResult 2865Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2866 bool &IsArrow, SourceLocation OpLoc, 2867 const CXXScopeSpec &SS, 2868 DeclPtrTy ObjCImpDecl) { 2869 assert(BaseExpr && "no base expression"); 2870 2871 // Perform default conversions. 2872 DefaultFunctionArrayConversion(BaseExpr); 2873 2874 QualType BaseType = BaseExpr->getType(); 2875 assert(!BaseType->isDependentType()); 2876 2877 DeclarationName MemberName = R.getLookupName(); 2878 SourceLocation MemberLoc = R.getNameLoc(); 2879 2880 // If the user is trying to apply -> or . to a function pointer 2881 // type, it's probably because they forgot parentheses to call that 2882 // function. Suggest the addition of those parentheses, build the 2883 // call, and continue on. 2884 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 2885 if (const FunctionProtoType *Fun 2886 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 2887 QualType ResultTy = Fun->getResultType(); 2888 if (Fun->getNumArgs() == 0 && 2889 ((!IsArrow && ResultTy->isRecordType()) || 2890 (IsArrow && ResultTy->isPointerType() && 2891 ResultTy->getAs<PointerType>()->getPointeeType() 2892 ->isRecordType()))) { 2893 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 2894 Diag(Loc, diag::err_member_reference_needs_call) 2895 << QualType(Fun, 0) 2896 << CodeModificationHint::CreateInsertion(Loc, "()"); 2897 2898 OwningExprResult NewBase 2899 = ActOnCallExpr(0, ExprArg(*this, BaseExpr), Loc, 2900 MultiExprArg(*this, 0, 0), 0, Loc); 2901 if (NewBase.isInvalid()) 2902 return ExprError(); 2903 2904 BaseExpr = NewBase.takeAs<Expr>(); 2905 DefaultFunctionArrayConversion(BaseExpr); 2906 BaseType = BaseExpr->getType(); 2907 } 2908 } 2909 } 2910 2911 // If this is an Objective-C pseudo-builtin and a definition is provided then 2912 // use that. 2913 if (BaseType->isObjCIdType()) { 2914 if (IsArrow) { 2915 // Handle the following exceptional case PObj->isa. 2916 if (const ObjCObjectPointerType *OPT = 2917 BaseType->getAs<ObjCObjectPointerType>()) { 2918 if (OPT->getPointeeType()->isSpecificBuiltinType(BuiltinType::ObjCId) && 2919 MemberName.getAsIdentifierInfo()->isStr("isa")) 2920 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 2921 Context.getObjCClassType())); 2922 } 2923 } 2924 // We have an 'id' type. Rather than fall through, we check if this 2925 // is a reference to 'isa'. 2926 if (BaseType != Context.ObjCIdRedefinitionType) { 2927 BaseType = Context.ObjCIdRedefinitionType; 2928 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2929 } 2930 } 2931 2932 // If this is an Objective-C pseudo-builtin and a definition is provided then 2933 // use that. 2934 if (Context.isObjCSelType(BaseType)) { 2935 // We have an 'SEL' type. Rather than fall through, we check if this 2936 // is a reference to 'sel_id'. 2937 if (BaseType != Context.ObjCSelRedefinitionType) { 2938 BaseType = Context.ObjCSelRedefinitionType; 2939 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2940 } 2941 } 2942 2943 assert(!BaseType.isNull() && "no type for member expression"); 2944 2945 // Handle properties on ObjC 'Class' types. 2946 if (!IsArrow && BaseType->isObjCClassType()) { 2947 // Also must look for a getter name which uses property syntax. 2948 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 2949 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 2950 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2951 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 2952 ObjCMethodDecl *Getter; 2953 // FIXME: need to also look locally in the implementation. 2954 if ((Getter = IFace->lookupClassMethod(Sel))) { 2955 // Check the use of this method. 2956 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 2957 return ExprError(); 2958 } 2959 // If we found a getter then this may be a valid dot-reference, we 2960 // will look for the matching setter, in case it is needed. 2961 Selector SetterSel = 2962 SelectorTable::constructSetterName(PP.getIdentifierTable(), 2963 PP.getSelectorTable(), Member); 2964 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 2965 if (!Setter) { 2966 // If this reference is in an @implementation, also check for 'private' 2967 // methods. 2968 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 2969 } 2970 // Look through local category implementations associated with the class. 2971 if (!Setter) 2972 Setter = IFace->getCategoryClassMethod(SetterSel); 2973 2974 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 2975 return ExprError(); 2976 2977 if (Getter || Setter) { 2978 QualType PType; 2979 2980 if (Getter) 2981 PType = Getter->getResultType(); 2982 else 2983 // Get the expression type from Setter's incoming parameter. 2984 PType = (*(Setter->param_end() -1))->getType(); 2985 // FIXME: we must check that the setter has property type. 2986 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 2987 PType, 2988 Setter, MemberLoc, BaseExpr)); 2989 } 2990 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 2991 << MemberName << BaseType); 2992 } 2993 } 2994 2995 if (BaseType->isObjCClassType() && 2996 BaseType != Context.ObjCClassRedefinitionType) { 2997 BaseType = Context.ObjCClassRedefinitionType; 2998 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2999 } 3000 3001 if (IsArrow) { 3002 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3003 BaseType = PT->getPointeeType(); 3004 else if (BaseType->isObjCObjectPointerType()) 3005 ; 3006 else if (BaseType->isRecordType()) { 3007 // Recover from arrow accesses to records, e.g.: 3008 // struct MyRecord foo; 3009 // foo->bar 3010 // This is actually well-formed in C++ if MyRecord has an 3011 // overloaded operator->, but that should have been dealt with 3012 // by now. 3013 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3014 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3015 << CodeModificationHint::CreateReplacement(OpLoc, "."); 3016 IsArrow = false; 3017 } else { 3018 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3019 << BaseType << BaseExpr->getSourceRange(); 3020 return ExprError(); 3021 } 3022 } else { 3023 // Recover from dot accesses to pointers, e.g.: 3024 // type *foo; 3025 // foo.bar 3026 // This is actually well-formed in two cases: 3027 // - 'type' is an Objective C type 3028 // - 'bar' is a pseudo-destructor name which happens to refer to 3029 // the appropriate pointer type 3030 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3031 const PointerType *PT = BaseType->getAs<PointerType>(); 3032 if (PT && PT->getPointeeType()->isRecordType()) { 3033 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3034 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3035 << CodeModificationHint::CreateReplacement(OpLoc, "->"); 3036 BaseType = PT->getPointeeType(); 3037 IsArrow = true; 3038 } 3039 } 3040 } 3041 3042 // Handle field access to simple records. This also handles access 3043 // to fields of the ObjC 'id' struct. 3044 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3045 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3046 RTy, OpLoc, SS)) 3047 return ExprError(); 3048 return Owned((Expr*) 0); 3049 } 3050 3051 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3052 // (*Obj).ivar. 3053 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3054 (!IsArrow && BaseType->isObjCInterfaceType())) { 3055 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3056 const ObjCInterfaceType *IFaceT = 3057 OPT ? OPT->getInterfaceType() : BaseType->getAs<ObjCInterfaceType>(); 3058 if (IFaceT) { 3059 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3060 3061 ObjCInterfaceDecl *IDecl = IFaceT->getDecl(); 3062 ObjCInterfaceDecl *ClassDeclared; 3063 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3064 3065 if (!IV) { 3066 // Attempt to correct for typos in ivar names. 3067 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3068 LookupMemberName); 3069 if (CorrectTypo(Res, 0, 0, IDecl) && 3070 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3071 Diag(R.getNameLoc(), 3072 diag::err_typecheck_member_reference_ivar_suggest) 3073 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3074 << CodeModificationHint::CreateReplacement(R.getNameLoc(), 3075 IV->getNameAsString()); 3076 Diag(IV->getLocation(), diag::note_previous_decl) 3077 << IV->getDeclName(); 3078 } 3079 } 3080 3081 if (IV) { 3082 // If the decl being referenced had an error, return an error for this 3083 // sub-expr without emitting another error, in order to avoid cascading 3084 // error cases. 3085 if (IV->isInvalidDecl()) 3086 return ExprError(); 3087 3088 // Check whether we can reference this field. 3089 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3090 return ExprError(); 3091 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3092 IV->getAccessControl() != ObjCIvarDecl::Package) { 3093 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3094 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3095 ClassOfMethodDecl = MD->getClassInterface(); 3096 else if (ObjCImpDecl && getCurFunctionDecl()) { 3097 // Case of a c-function declared inside an objc implementation. 3098 // FIXME: For a c-style function nested inside an objc implementation 3099 // class, there is no implementation context available, so we pass 3100 // down the context as argument to this routine. Ideally, this context 3101 // need be passed down in the AST node and somehow calculated from the 3102 // AST for a function decl. 3103 Decl *ImplDecl = ObjCImpDecl.getAs<Decl>(); 3104 if (ObjCImplementationDecl *IMPD = 3105 dyn_cast<ObjCImplementationDecl>(ImplDecl)) 3106 ClassOfMethodDecl = IMPD->getClassInterface(); 3107 else if (ObjCCategoryImplDecl* CatImplClass = 3108 dyn_cast<ObjCCategoryImplDecl>(ImplDecl)) 3109 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3110 } 3111 3112 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3113 if (ClassDeclared != IDecl || 3114 ClassOfMethodDecl != ClassDeclared) 3115 Diag(MemberLoc, diag::error_private_ivar_access) 3116 << IV->getDeclName(); 3117 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3118 // @protected 3119 Diag(MemberLoc, diag::error_protected_ivar_access) 3120 << IV->getDeclName(); 3121 } 3122 3123 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3124 MemberLoc, BaseExpr, 3125 IsArrow)); 3126 } 3127 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3128 << IDecl->getDeclName() << MemberName 3129 << BaseExpr->getSourceRange()); 3130 } 3131 } 3132 // Handle properties on 'id' and qualified "id". 3133 if (!IsArrow && (BaseType->isObjCIdType() || 3134 BaseType->isObjCQualifiedIdType())) { 3135 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3136 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3137 3138 // Check protocols on qualified interfaces. 3139 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3140 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3141 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3142 // Check the use of this declaration 3143 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3144 return ExprError(); 3145 3146 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3147 MemberLoc, BaseExpr)); 3148 } 3149 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3150 // Check the use of this method. 3151 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3152 return ExprError(); 3153 3154 return Owned(new (Context) ObjCMessageExpr(Context, BaseExpr, Sel, 3155 OMD->getResultType(), 3156 OMD, OpLoc, MemberLoc, 3157 NULL, 0)); 3158 } 3159 } 3160 3161 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3162 << MemberName << BaseType); 3163 } 3164 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3165 // pointer to a (potentially qualified) interface type. 3166 const ObjCObjectPointerType *OPT; 3167 if (!IsArrow && (OPT = BaseType->getAsObjCInterfacePointerType())) { 3168 const ObjCInterfaceType *IFaceT = OPT->getInterfaceType(); 3169 ObjCInterfaceDecl *IFace = IFaceT->getDecl(); 3170 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3171 3172 // Search for a declared property first. 3173 if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) { 3174 // Check whether we can reference this property. 3175 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3176 return ExprError(); 3177 QualType ResTy = PD->getType(); 3178 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3179 ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel); 3180 if (DiagnosePropertyAccessorMismatch(PD, Getter, MemberLoc)) 3181 ResTy = Getter->getResultType(); 3182 return Owned(new (Context) ObjCPropertyRefExpr(PD, ResTy, 3183 MemberLoc, BaseExpr)); 3184 } 3185 // Check protocols on qualified interfaces. 3186 for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(), 3187 E = OPT->qual_end(); I != E; ++I) 3188 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 3189 // Check whether we can reference this property. 3190 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3191 return ExprError(); 3192 3193 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3194 MemberLoc, BaseExpr)); 3195 } 3196 // If that failed, look for an "implicit" property by seeing if the nullary 3197 // selector is implemented. 3198 3199 // FIXME: The logic for looking up nullary and unary selectors should be 3200 // shared with the code in ActOnInstanceMessage. 3201 3202 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3203 ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel); 3204 3205 // If this reference is in an @implementation, check for 'private' methods. 3206 if (!Getter) 3207 Getter = IFace->lookupPrivateInstanceMethod(Sel); 3208 3209 // Look through local category implementations associated with the class. 3210 if (!Getter) 3211 Getter = IFace->getCategoryInstanceMethod(Sel); 3212 if (Getter) { 3213 // Check if we can reference this property. 3214 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3215 return ExprError(); 3216 } 3217 // If we found a getter then this may be a valid dot-reference, we 3218 // will look for the matching setter, in case it is needed. 3219 Selector SetterSel = 3220 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3221 PP.getSelectorTable(), Member); 3222 ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel); 3223 if (!Setter) { 3224 // If this reference is in an @implementation, also check for 'private' 3225 // methods. 3226 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3227 } 3228 // Look through local category implementations associated with the class. 3229 if (!Setter) 3230 Setter = IFace->getCategoryInstanceMethod(SetterSel); 3231 3232 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3233 return ExprError(); 3234 3235 if (Getter) { 3236 QualType PType; 3237 PType = Getter->getResultType(); 3238 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, PType, 3239 Setter, MemberLoc, BaseExpr)); 3240 } 3241 3242 // Attempt to correct for typos in property names. 3243 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3244 LookupOrdinaryName); 3245 if (CorrectTypo(Res, 0, 0, IFace, false, OPT) && 3246 Res.getAsSingle<ObjCPropertyDecl>()) { 3247 Diag(R.getNameLoc(), diag::err_property_not_found_suggest) 3248 << MemberName << BaseType << Res.getLookupName() 3249 << CodeModificationHint::CreateReplacement(R.getNameLoc(), 3250 Res.getLookupName().getAsString()); 3251 ObjCPropertyDecl *Property = Res.getAsSingle<ObjCPropertyDecl>(); 3252 Diag(Property->getLocation(), diag::note_previous_decl) 3253 << Property->getDeclName(); 3254 3255 return LookupMemberExpr(Res, BaseExpr, IsArrow, OpLoc, SS, 3256 ObjCImpDecl); 3257 } 3258 Diag(MemberLoc, diag::err_property_not_found) 3259 << MemberName << BaseType; 3260 if (Setter && !Getter) 3261 Diag(Setter->getLocation(), diag::note_getter_unavailable) 3262 << MemberName << BaseExpr->getSourceRange(); 3263 return ExprError(); 3264 } 3265 3266 // Handle the following exceptional case (*Obj).isa. 3267 if (!IsArrow && 3268 BaseType->isSpecificBuiltinType(BuiltinType::ObjCId) && 3269 MemberName.getAsIdentifierInfo()->isStr("isa")) 3270 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3271 Context.getObjCClassType())); 3272 3273 // Handle 'field access' to vectors, such as 'V.xx'. 3274 if (BaseType->isExtVectorType()) { 3275 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3276 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3277 if (ret.isNull()) 3278 return ExprError(); 3279 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3280 MemberLoc)); 3281 } 3282 3283 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3284 << BaseType << BaseExpr->getSourceRange(); 3285 3286 return ExprError(); 3287} 3288 3289/// The main callback when the parser finds something like 3290/// expression . [nested-name-specifier] identifier 3291/// expression -> [nested-name-specifier] identifier 3292/// where 'identifier' encompasses a fairly broad spectrum of 3293/// possibilities, including destructor and operator references. 3294/// 3295/// \param OpKind either tok::arrow or tok::period 3296/// \param HasTrailingLParen whether the next token is '(', which 3297/// is used to diagnose mis-uses of special members that can 3298/// only be called 3299/// \param ObjCImpDecl the current ObjC @implementation decl; 3300/// this is an ugly hack around the fact that ObjC @implementations 3301/// aren't properly put in the context chain 3302Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, ExprArg BaseArg, 3303 SourceLocation OpLoc, 3304 tok::TokenKind OpKind, 3305 const CXXScopeSpec &SS, 3306 UnqualifiedId &Id, 3307 DeclPtrTy ObjCImpDecl, 3308 bool HasTrailingLParen) { 3309 if (SS.isSet() && SS.isInvalid()) 3310 return ExprError(); 3311 3312 TemplateArgumentListInfo TemplateArgsBuffer; 3313 3314 // Decompose the name into its component parts. 3315 DeclarationName Name; 3316 SourceLocation NameLoc; 3317 const TemplateArgumentListInfo *TemplateArgs; 3318 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3319 Name, NameLoc, TemplateArgs); 3320 3321 bool IsArrow = (OpKind == tok::arrow); 3322 3323 NamedDecl *FirstQualifierInScope 3324 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3325 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3326 3327 // This is a postfix expression, so get rid of ParenListExprs. 3328 BaseArg = MaybeConvertParenListExprToParenExpr(S, move(BaseArg)); 3329 3330 Expr *Base = BaseArg.takeAs<Expr>(); 3331 OwningExprResult Result(*this); 3332 if (Base->getType()->isDependentType() || Name.isDependentName()) { 3333 Result = ActOnDependentMemberExpr(ExprArg(*this, Base), Base->getType(), 3334 IsArrow, OpLoc, 3335 SS, FirstQualifierInScope, 3336 Name, NameLoc, 3337 TemplateArgs); 3338 } else { 3339 LookupResult R(*this, Name, NameLoc, LookupMemberName); 3340 if (TemplateArgs) { 3341 // Re-use the lookup done for the template name. 3342 DecomposeTemplateName(R, Id); 3343 } else { 3344 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3345 SS, ObjCImpDecl); 3346 3347 if (Result.isInvalid()) { 3348 Owned(Base); 3349 return ExprError(); 3350 } 3351 3352 if (Result.get()) { 3353 // The only way a reference to a destructor can be used is to 3354 // immediately call it, which falls into this case. If the 3355 // next token is not a '(', produce a diagnostic and build the 3356 // call now. 3357 if (!HasTrailingLParen && 3358 Id.getKind() == UnqualifiedId::IK_DestructorName) 3359 return DiagnoseDtorReference(NameLoc, move(Result)); 3360 3361 return move(Result); 3362 } 3363 } 3364 3365 Result = BuildMemberReferenceExpr(ExprArg(*this, Base), Base->getType(), 3366 OpLoc, IsArrow, SS, FirstQualifierInScope, 3367 R, TemplateArgs); 3368 } 3369 3370 return move(Result); 3371} 3372 3373Sema::OwningExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3374 FunctionDecl *FD, 3375 ParmVarDecl *Param) { 3376 if (Param->hasUnparsedDefaultArg()) { 3377 Diag (CallLoc, 3378 diag::err_use_of_default_argument_to_function_declared_later) << 3379 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3380 Diag(UnparsedDefaultArgLocs[Param], 3381 diag::note_default_argument_declared_here); 3382 } else { 3383 if (Param->hasUninstantiatedDefaultArg()) { 3384 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3385 3386 // Instantiate the expression. 3387 MultiLevelTemplateArgumentList ArgList 3388 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3389 3390 InstantiatingTemplate Inst(*this, CallLoc, Param, 3391 ArgList.getInnermost().getFlatArgumentList(), 3392 ArgList.getInnermost().flat_size()); 3393 3394 OwningExprResult Result = SubstExpr(UninstExpr, ArgList); 3395 if (Result.isInvalid()) 3396 return ExprError(); 3397 3398 // Check the expression as an initializer for the parameter. 3399 InitializedEntity Entity 3400 = InitializedEntity::InitializeParameter(Param); 3401 InitializationKind Kind 3402 = InitializationKind::CreateCopy(Param->getLocation(), 3403 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3404 Expr *ResultE = Result.takeAs<Expr>(); 3405 3406 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3407 Result = InitSeq.Perform(*this, Entity, Kind, 3408 MultiExprArg(*this, (void**)&ResultE, 1)); 3409 if (Result.isInvalid()) 3410 return ExprError(); 3411 3412 // Build the default argument expression. 3413 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3414 Result.takeAs<Expr>())); 3415 } 3416 3417 // If the default expression creates temporaries, we need to 3418 // push them to the current stack of expression temporaries so they'll 3419 // be properly destroyed. 3420 // FIXME: We should really be rebuilding the default argument with new 3421 // bound temporaries; see the comment in PR5810. 3422 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3423 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3424 } 3425 3426 // We already type-checked the argument, so we know it works. 3427 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3428} 3429 3430/// ConvertArgumentsForCall - Converts the arguments specified in 3431/// Args/NumArgs to the parameter types of the function FDecl with 3432/// function prototype Proto. Call is the call expression itself, and 3433/// Fn is the function expression. For a C++ member function, this 3434/// routine does not attempt to convert the object argument. Returns 3435/// true if the call is ill-formed. 3436bool 3437Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3438 FunctionDecl *FDecl, 3439 const FunctionProtoType *Proto, 3440 Expr **Args, unsigned NumArgs, 3441 SourceLocation RParenLoc) { 3442 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3443 // assignment, to the types of the corresponding parameter, ... 3444 unsigned NumArgsInProto = Proto->getNumArgs(); 3445 bool Invalid = false; 3446 3447 // If too few arguments are available (and we don't have default 3448 // arguments for the remaining parameters), don't make the call. 3449 if (NumArgs < NumArgsInProto) { 3450 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3451 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3452 << Fn->getType()->isBlockPointerType() << Fn->getSourceRange(); 3453 Call->setNumArgs(Context, NumArgsInProto); 3454 } 3455 3456 // If too many are passed and not variadic, error on the extras and drop 3457 // them. 3458 if (NumArgs > NumArgsInProto) { 3459 if (!Proto->isVariadic()) { 3460 Diag(Args[NumArgsInProto]->getLocStart(), 3461 diag::err_typecheck_call_too_many_args) 3462 << Fn->getType()->isBlockPointerType() << Fn->getSourceRange() 3463 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3464 Args[NumArgs-1]->getLocEnd()); 3465 // This deletes the extra arguments. 3466 Call->setNumArgs(Context, NumArgsInProto); 3467 return true; 3468 } 3469 } 3470 llvm::SmallVector<Expr *, 8> AllArgs; 3471 VariadicCallType CallType = 3472 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3473 if (Fn->getType()->isBlockPointerType()) 3474 CallType = VariadicBlock; // Block 3475 else if (isa<MemberExpr>(Fn)) 3476 CallType = VariadicMethod; 3477 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3478 Proto, 0, Args, NumArgs, AllArgs, CallType); 3479 if (Invalid) 3480 return true; 3481 unsigned TotalNumArgs = AllArgs.size(); 3482 for (unsigned i = 0; i < TotalNumArgs; ++i) 3483 Call->setArg(i, AllArgs[i]); 3484 3485 return false; 3486} 3487 3488bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3489 FunctionDecl *FDecl, 3490 const FunctionProtoType *Proto, 3491 unsigned FirstProtoArg, 3492 Expr **Args, unsigned NumArgs, 3493 llvm::SmallVector<Expr *, 8> &AllArgs, 3494 VariadicCallType CallType) { 3495 unsigned NumArgsInProto = Proto->getNumArgs(); 3496 unsigned NumArgsToCheck = NumArgs; 3497 bool Invalid = false; 3498 if (NumArgs != NumArgsInProto) 3499 // Use default arguments for missing arguments 3500 NumArgsToCheck = NumArgsInProto; 3501 unsigned ArgIx = 0; 3502 // Continue to check argument types (even if we have too few/many args). 3503 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3504 QualType ProtoArgType = Proto->getArgType(i); 3505 3506 Expr *Arg; 3507 if (ArgIx < NumArgs) { 3508 Arg = Args[ArgIx++]; 3509 3510 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3511 ProtoArgType, 3512 PDiag(diag::err_call_incomplete_argument) 3513 << Arg->getSourceRange())) 3514 return true; 3515 3516 // Pass the argument 3517 ParmVarDecl *Param = 0; 3518 if (FDecl && i < FDecl->getNumParams()) 3519 Param = FDecl->getParamDecl(i); 3520 3521 3522 InitializedEntity Entity = 3523 Param? InitializedEntity::InitializeParameter(Param) 3524 : InitializedEntity::InitializeParameter(ProtoArgType); 3525 OwningExprResult ArgE = PerformCopyInitialization(Entity, 3526 SourceLocation(), 3527 Owned(Arg)); 3528 if (ArgE.isInvalid()) 3529 return true; 3530 3531 Arg = ArgE.takeAs<Expr>(); 3532 } else { 3533 ParmVarDecl *Param = FDecl->getParamDecl(i); 3534 3535 OwningExprResult ArgExpr = 3536 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3537 if (ArgExpr.isInvalid()) 3538 return true; 3539 3540 Arg = ArgExpr.takeAs<Expr>(); 3541 } 3542 AllArgs.push_back(Arg); 3543 } 3544 3545 // If this is a variadic call, handle args passed through "...". 3546 if (CallType != VariadicDoesNotApply) { 3547 // Promote the arguments (C99 6.5.2.2p7). 3548 for (unsigned i = ArgIx; i < NumArgs; i++) { 3549 Expr *Arg = Args[i]; 3550 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType); 3551 AllArgs.push_back(Arg); 3552 } 3553 } 3554 return Invalid; 3555} 3556 3557/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3558/// This provides the location of the left/right parens and a list of comma 3559/// locations. 3560Action::OwningExprResult 3561Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc, 3562 MultiExprArg args, 3563 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3564 unsigned NumArgs = args.size(); 3565 3566 // Since this might be a postfix expression, get rid of ParenListExprs. 3567 fn = MaybeConvertParenListExprToParenExpr(S, move(fn)); 3568 3569 Expr *Fn = fn.takeAs<Expr>(); 3570 Expr **Args = reinterpret_cast<Expr**>(args.release()); 3571 assert(Fn && "no function call expression"); 3572 3573 if (getLangOptions().CPlusPlus) { 3574 // If this is a pseudo-destructor expression, build the call immediately. 3575 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3576 if (NumArgs > 0) { 3577 // Pseudo-destructor calls should not have any arguments. 3578 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3579 << CodeModificationHint::CreateRemoval( 3580 SourceRange(Args[0]->getLocStart(), 3581 Args[NumArgs-1]->getLocEnd())); 3582 3583 for (unsigned I = 0; I != NumArgs; ++I) 3584 Args[I]->Destroy(Context); 3585 3586 NumArgs = 0; 3587 } 3588 3589 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3590 RParenLoc)); 3591 } 3592 3593 // Determine whether this is a dependent call inside a C++ template, 3594 // in which case we won't do any semantic analysis now. 3595 // FIXME: Will need to cache the results of name lookup (including ADL) in 3596 // Fn. 3597 bool Dependent = false; 3598 if (Fn->isTypeDependent()) 3599 Dependent = true; 3600 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3601 Dependent = true; 3602 3603 if (Dependent) 3604 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3605 Context.DependentTy, RParenLoc)); 3606 3607 // Determine whether this is a call to an object (C++ [over.call.object]). 3608 if (Fn->getType()->isRecordType()) 3609 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3610 CommaLocs, RParenLoc)); 3611 3612 Expr *NakedFn = Fn->IgnoreParens(); 3613 3614 // Determine whether this is a call to an unresolved member function. 3615 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3616 // If lookup was unresolved but not dependent (i.e. didn't find 3617 // an unresolved using declaration), it has to be an overloaded 3618 // function set, which means it must contain either multiple 3619 // declarations (all methods or method templates) or a single 3620 // method template. 3621 assert((MemE->getNumDecls() > 1) || 3622 isa<FunctionTemplateDecl>(*MemE->decls_begin())); 3623 (void)MemE; 3624 3625 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3626 CommaLocs, RParenLoc); 3627 } 3628 3629 // Determine whether this is a call to a member function. 3630 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3631 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3632 if (isa<CXXMethodDecl>(MemDecl)) 3633 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3634 CommaLocs, RParenLoc); 3635 } 3636 3637 // Determine whether this is a call to a pointer-to-member function. 3638 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3639 if (BO->getOpcode() == BinaryOperator::PtrMemD || 3640 BO->getOpcode() == BinaryOperator::PtrMemI) { 3641 if (const FunctionProtoType *FPT = 3642 dyn_cast<FunctionProtoType>(BO->getType())) { 3643 QualType ResultTy = FPT->getResultType().getNonReferenceType(); 3644 3645 ExprOwningPtr<CXXMemberCallExpr> 3646 TheCall(this, new (Context) CXXMemberCallExpr(Context, BO, Args, 3647 NumArgs, ResultTy, 3648 RParenLoc)); 3649 3650 if (CheckCallReturnType(FPT->getResultType(), 3651 BO->getRHS()->getSourceRange().getBegin(), 3652 TheCall.get(), 0)) 3653 return ExprError(); 3654 3655 if (ConvertArgumentsForCall(&*TheCall, BO, 0, FPT, Args, NumArgs, 3656 RParenLoc)) 3657 return ExprError(); 3658 3659 return Owned(MaybeBindToTemporary(TheCall.release()).release()); 3660 } 3661 return ExprError(Diag(Fn->getLocStart(), 3662 diag::err_typecheck_call_not_function) 3663 << Fn->getType() << Fn->getSourceRange()); 3664 } 3665 } 3666 } 3667 3668 // If we're directly calling a function, get the appropriate declaration. 3669 // Also, in C++, keep track of whether we should perform argument-dependent 3670 // lookup and whether there were any explicitly-specified template arguments. 3671 3672 Expr *NakedFn = Fn->IgnoreParens(); 3673 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3674 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3675 return BuildOverloadedCallExpr(Fn, ULE, LParenLoc, Args, NumArgs, 3676 CommaLocs, RParenLoc); 3677 } 3678 3679 NamedDecl *NDecl = 0; 3680 if (isa<DeclRefExpr>(NakedFn)) 3681 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3682 3683 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3684} 3685 3686/// BuildResolvedCallExpr - Build a call to a resolved expression, 3687/// i.e. an expression not of \p OverloadTy. The expression should 3688/// unary-convert to an expression of function-pointer or 3689/// block-pointer type. 3690/// 3691/// \param NDecl the declaration being called, if available 3692Sema::OwningExprResult 3693Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3694 SourceLocation LParenLoc, 3695 Expr **Args, unsigned NumArgs, 3696 SourceLocation RParenLoc) { 3697 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3698 3699 // Promote the function operand. 3700 UsualUnaryConversions(Fn); 3701 3702 // Make the call expr early, before semantic checks. This guarantees cleanup 3703 // of arguments and function on error. 3704 ExprOwningPtr<CallExpr> TheCall(this, new (Context) CallExpr(Context, Fn, 3705 Args, NumArgs, 3706 Context.BoolTy, 3707 RParenLoc)); 3708 3709 const FunctionType *FuncT; 3710 if (!Fn->getType()->isBlockPointerType()) { 3711 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3712 // have type pointer to function". 3713 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3714 if (PT == 0) 3715 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3716 << Fn->getType() << Fn->getSourceRange()); 3717 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3718 } else { // This is a block call. 3719 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3720 getAs<FunctionType>(); 3721 } 3722 if (FuncT == 0) 3723 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3724 << Fn->getType() << Fn->getSourceRange()); 3725 3726 // Check for a valid return type 3727 if (CheckCallReturnType(FuncT->getResultType(), 3728 Fn->getSourceRange().getBegin(), TheCall.get(), 3729 FDecl)) 3730 return ExprError(); 3731 3732 // We know the result type of the call, set it. 3733 TheCall->setType(FuncT->getResultType().getNonReferenceType()); 3734 3735 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3736 if (ConvertArgumentsForCall(&*TheCall, Fn, FDecl, Proto, Args, NumArgs, 3737 RParenLoc)) 3738 return ExprError(); 3739 } else { 3740 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3741 3742 if (FDecl) { 3743 // Check if we have too few/too many template arguments, based 3744 // on our knowledge of the function definition. 3745 const FunctionDecl *Def = 0; 3746 if (FDecl->getBody(Def) && NumArgs != Def->param_size()) { 3747 const FunctionProtoType *Proto = 3748 Def->getType()->getAs<FunctionProtoType>(); 3749 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3750 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3751 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3752 } 3753 } 3754 } 3755 3756 // Promote the arguments (C99 6.5.2.2p6). 3757 for (unsigned i = 0; i != NumArgs; i++) { 3758 Expr *Arg = Args[i]; 3759 DefaultArgumentPromotion(Arg); 3760 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3761 Arg->getType(), 3762 PDiag(diag::err_call_incomplete_argument) 3763 << Arg->getSourceRange())) 3764 return ExprError(); 3765 TheCall->setArg(i, Arg); 3766 } 3767 } 3768 3769 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3770 if (!Method->isStatic()) 3771 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3772 << Fn->getSourceRange()); 3773 3774 // Check for sentinels 3775 if (NDecl) 3776 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3777 3778 // Do special checking on direct calls to functions. 3779 if (FDecl) { 3780 if (CheckFunctionCall(FDecl, TheCall.get())) 3781 return ExprError(); 3782 3783 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3784 return CheckBuiltinFunctionCall(BuiltinID, TheCall.take()); 3785 } else if (NDecl) { 3786 if (CheckBlockCall(NDecl, TheCall.get())) 3787 return ExprError(); 3788 } 3789 3790 return MaybeBindToTemporary(TheCall.take()); 3791} 3792 3793Action::OwningExprResult 3794Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, TypeTy *Ty, 3795 SourceLocation RParenLoc, ExprArg InitExpr) { 3796 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3797 // FIXME: put back this assert when initializers are worked out. 3798 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3799 3800 TypeSourceInfo *TInfo; 3801 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3802 if (!TInfo) 3803 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3804 3805 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, move(InitExpr)); 3806} 3807 3808Action::OwningExprResult 3809Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3810 SourceLocation RParenLoc, ExprArg InitExpr) { 3811 QualType literalType = TInfo->getType(); 3812 Expr *literalExpr = static_cast<Expr*>(InitExpr.get()); 3813 3814 if (literalType->isArrayType()) { 3815 if (literalType->isVariableArrayType()) 3816 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3817 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3818 } else if (!literalType->isDependentType() && 3819 RequireCompleteType(LParenLoc, literalType, 3820 PDiag(diag::err_typecheck_decl_incomplete_type) 3821 << SourceRange(LParenLoc, 3822 literalExpr->getSourceRange().getEnd()))) 3823 return ExprError(); 3824 3825 InitializedEntity Entity 3826 = InitializedEntity::InitializeTemporary(literalType); 3827 InitializationKind Kind 3828 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3829 /*IsCStyleCast=*/true); 3830 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3831 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3832 MultiExprArg(*this, (void**)&literalExpr, 1), 3833 &literalType); 3834 if (Result.isInvalid()) 3835 return ExprError(); 3836 InitExpr.release(); 3837 literalExpr = static_cast<Expr*>(Result.get()); 3838 3839 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3840 if (isFileScope) { // 6.5.2.5p3 3841 if (CheckForConstantInitializer(literalExpr, literalType)) 3842 return ExprError(); 3843 } 3844 3845 Result.release(); 3846 3847 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3848 literalExpr, isFileScope)); 3849} 3850 3851Action::OwningExprResult 3852Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3853 SourceLocation RBraceLoc) { 3854 unsigned NumInit = initlist.size(); 3855 Expr **InitList = reinterpret_cast<Expr**>(initlist.release()); 3856 3857 // Semantic analysis for initializers is done by ActOnDeclarator() and 3858 // CheckInitializer() - it requires knowledge of the object being intialized. 3859 3860 InitListExpr *E = new (Context) InitListExpr(LBraceLoc, InitList, NumInit, 3861 RBraceLoc); 3862 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3863 return Owned(E); 3864} 3865 3866static CastExpr::CastKind getScalarCastKind(ASTContext &Context, 3867 QualType SrcTy, QualType DestTy) { 3868 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3869 return CastExpr::CK_NoOp; 3870 3871 if (SrcTy->hasPointerRepresentation()) { 3872 if (DestTy->hasPointerRepresentation()) 3873 return DestTy->isObjCObjectPointerType() ? 3874 CastExpr::CK_AnyPointerToObjCPointerCast : 3875 CastExpr::CK_BitCast; 3876 if (DestTy->isIntegerType()) 3877 return CastExpr::CK_PointerToIntegral; 3878 } 3879 3880 if (SrcTy->isIntegerType()) { 3881 if (DestTy->isIntegerType()) 3882 return CastExpr::CK_IntegralCast; 3883 if (DestTy->hasPointerRepresentation()) 3884 return CastExpr::CK_IntegralToPointer; 3885 if (DestTy->isRealFloatingType()) 3886 return CastExpr::CK_IntegralToFloating; 3887 } 3888 3889 if (SrcTy->isRealFloatingType()) { 3890 if (DestTy->isRealFloatingType()) 3891 return CastExpr::CK_FloatingCast; 3892 if (DestTy->isIntegerType()) 3893 return CastExpr::CK_FloatingToIntegral; 3894 } 3895 3896 // FIXME: Assert here. 3897 // assert(false && "Unhandled cast combination!"); 3898 return CastExpr::CK_Unknown; 3899} 3900 3901/// CheckCastTypes - Check type constraints for casting between types. 3902bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3903 CastExpr::CastKind& Kind, 3904 CXXMethodDecl *& ConversionDecl, 3905 bool FunctionalStyle) { 3906 if (getLangOptions().CPlusPlus) 3907 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, FunctionalStyle, 3908 ConversionDecl); 3909 3910 DefaultFunctionArrayLvalueConversion(castExpr); 3911 3912 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3913 // type needs to be scalar. 3914 if (castType->isVoidType()) { 3915 // Cast to void allows any expr type. 3916 Kind = CastExpr::CK_ToVoid; 3917 return false; 3918 } 3919 3920 if (!castType->isScalarType() && !castType->isVectorType()) { 3921 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3922 (castType->isStructureType() || castType->isUnionType())) { 3923 // GCC struct/union extension: allow cast to self. 3924 // FIXME: Check that the cast destination type is complete. 3925 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3926 << castType << castExpr->getSourceRange(); 3927 Kind = CastExpr::CK_NoOp; 3928 return false; 3929 } 3930 3931 if (castType->isUnionType()) { 3932 // GCC cast to union extension 3933 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3934 RecordDecl::field_iterator Field, FieldEnd; 3935 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3936 Field != FieldEnd; ++Field) { 3937 if (Context.hasSameUnqualifiedType(Field->getType(), 3938 castExpr->getType())) { 3939 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3940 << castExpr->getSourceRange(); 3941 break; 3942 } 3943 } 3944 if (Field == FieldEnd) 3945 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3946 << castExpr->getType() << castExpr->getSourceRange(); 3947 Kind = CastExpr::CK_ToUnion; 3948 return false; 3949 } 3950 3951 // Reject any other conversions to non-scalar types. 3952 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3953 << castType << castExpr->getSourceRange(); 3954 } 3955 3956 if (!castExpr->getType()->isScalarType() && 3957 !castExpr->getType()->isVectorType()) { 3958 return Diag(castExpr->getLocStart(), 3959 diag::err_typecheck_expect_scalar_operand) 3960 << castExpr->getType() << castExpr->getSourceRange(); 3961 } 3962 3963 if (castType->isExtVectorType()) 3964 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3965 3966 if (castType->isVectorType()) 3967 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 3968 if (castExpr->getType()->isVectorType()) 3969 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 3970 3971 if (getLangOptions().ObjC1 && isa<ObjCSuperExpr>(castExpr)) 3972 return Diag(castExpr->getLocStart(), diag::err_illegal_super_cast) << TyR; 3973 3974 if (isa<ObjCSelectorExpr>(castExpr)) 3975 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 3976 3977 if (!castType->isArithmeticType()) { 3978 QualType castExprType = castExpr->getType(); 3979 if (!castExprType->isIntegralType() && castExprType->isArithmeticType()) 3980 return Diag(castExpr->getLocStart(), 3981 diag::err_cast_pointer_from_non_pointer_int) 3982 << castExprType << castExpr->getSourceRange(); 3983 } else if (!castExpr->getType()->isArithmeticType()) { 3984 if (!castType->isIntegralType() && castType->isArithmeticType()) 3985 return Diag(castExpr->getLocStart(), 3986 diag::err_cast_pointer_to_non_pointer_int) 3987 << castType << castExpr->getSourceRange(); 3988 } 3989 3990 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 3991 return false; 3992} 3993 3994bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 3995 CastExpr::CastKind &Kind) { 3996 assert(VectorTy->isVectorType() && "Not a vector type!"); 3997 3998 if (Ty->isVectorType() || Ty->isIntegerType()) { 3999 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 4000 return Diag(R.getBegin(), 4001 Ty->isVectorType() ? 4002 diag::err_invalid_conversion_between_vectors : 4003 diag::err_invalid_conversion_between_vector_and_integer) 4004 << VectorTy << Ty << R; 4005 } else 4006 return Diag(R.getBegin(), 4007 diag::err_invalid_conversion_between_vector_and_scalar) 4008 << VectorTy << Ty << R; 4009 4010 Kind = CastExpr::CK_BitCast; 4011 return false; 4012} 4013 4014bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4015 CastExpr::CastKind &Kind) { 4016 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4017 4018 QualType SrcTy = CastExpr->getType(); 4019 4020 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4021 // an ExtVectorType. 4022 if (SrcTy->isVectorType()) { 4023 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4024 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4025 << DestTy << SrcTy << R; 4026 Kind = CastExpr::CK_BitCast; 4027 return false; 4028 } 4029 4030 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4031 // conversion will take place first from scalar to elt type, and then 4032 // splat from elt type to vector. 4033 if (SrcTy->isPointerType()) 4034 return Diag(R.getBegin(), 4035 diag::err_invalid_conversion_between_vector_and_scalar) 4036 << DestTy << SrcTy << R; 4037 4038 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4039 ImpCastExprToType(CastExpr, DestElemTy, 4040 getScalarCastKind(Context, SrcTy, DestElemTy)); 4041 4042 Kind = CastExpr::CK_VectorSplat; 4043 return false; 4044} 4045 4046Action::OwningExprResult 4047Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, TypeTy *Ty, 4048 SourceLocation RParenLoc, ExprArg Op) { 4049 assert((Ty != 0) && (Op.get() != 0) && 4050 "ActOnCastExpr(): missing type or expr"); 4051 4052 TypeSourceInfo *castTInfo; 4053 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4054 if (!castTInfo) 4055 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4056 4057 // If the Expr being casted is a ParenListExpr, handle it specially. 4058 Expr *castExpr = (Expr *)Op.get(); 4059 if (isa<ParenListExpr>(castExpr)) 4060 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, move(Op), 4061 castTInfo); 4062 4063 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, move(Op)); 4064} 4065 4066Action::OwningExprResult 4067Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4068 SourceLocation RParenLoc, ExprArg Op) { 4069 Expr *castExpr = static_cast<Expr*>(Op.get()); 4070 4071 CXXMethodDecl *Method = 0; 4072 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 4073 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4074 Kind, Method)) 4075 return ExprError(); 4076 4077 if (Method) { 4078 // FIXME: preserve type source info here 4079 OwningExprResult CastArg = BuildCXXCastArgument(LParenLoc, Ty->getType(), 4080 Kind, Method, move(Op)); 4081 4082 if (CastArg.isInvalid()) 4083 return ExprError(); 4084 4085 castExpr = CastArg.takeAs<Expr>(); 4086 } else { 4087 Op.release(); 4088 } 4089 4090 return Owned(new (Context) CStyleCastExpr(Ty->getType().getNonReferenceType(), 4091 Kind, castExpr, Ty, 4092 LParenLoc, RParenLoc)); 4093} 4094 4095/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4096/// of comma binary operators. 4097Action::OwningExprResult 4098Sema::MaybeConvertParenListExprToParenExpr(Scope *S, ExprArg EA) { 4099 Expr *expr = EA.takeAs<Expr>(); 4100 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4101 if (!E) 4102 return Owned(expr); 4103 4104 OwningExprResult Result(*this, E->getExpr(0)); 4105 4106 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4107 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, move(Result), 4108 Owned(E->getExpr(i))); 4109 4110 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), move(Result)); 4111} 4112 4113Action::OwningExprResult 4114Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4115 SourceLocation RParenLoc, ExprArg Op, 4116 TypeSourceInfo *TInfo) { 4117 ParenListExpr *PE = (ParenListExpr *)Op.get(); 4118 QualType Ty = TInfo->getType(); 4119 4120 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4121 // then handle it as such. 4122 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4123 if (PE->getNumExprs() == 0) { 4124 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4125 return ExprError(); 4126 } 4127 4128 llvm::SmallVector<Expr *, 8> initExprs; 4129 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4130 initExprs.push_back(PE->getExpr(i)); 4131 4132 // FIXME: This means that pretty-printing the final AST will produce curly 4133 // braces instead of the original commas. 4134 Op.release(); 4135 InitListExpr *E = new (Context) InitListExpr(LParenLoc, &initExprs[0], 4136 initExprs.size(), RParenLoc); 4137 E->setType(Ty); 4138 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, Owned(E)); 4139 } else { 4140 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4141 // sequence of BinOp comma operators. 4142 Op = MaybeConvertParenListExprToParenExpr(S, move(Op)); 4143 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, move(Op)); 4144 } 4145} 4146 4147Action::OwningExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4148 SourceLocation R, 4149 MultiExprArg Val, 4150 TypeTy *TypeOfCast) { 4151 unsigned nexprs = Val.size(); 4152 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4153 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4154 Expr *expr; 4155 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4156 expr = new (Context) ParenExpr(L, R, exprs[0]); 4157 else 4158 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4159 return Owned(expr); 4160} 4161 4162/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4163/// In that case, lhs = cond. 4164/// C99 6.5.15 4165QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4166 SourceLocation QuestionLoc) { 4167 // C++ is sufficiently different to merit its own checker. 4168 if (getLangOptions().CPlusPlus) 4169 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4170 4171 CheckSignCompare(LHS, RHS, QuestionLoc); 4172 4173 UsualUnaryConversions(Cond); 4174 UsualUnaryConversions(LHS); 4175 UsualUnaryConversions(RHS); 4176 QualType CondTy = Cond->getType(); 4177 QualType LHSTy = LHS->getType(); 4178 QualType RHSTy = RHS->getType(); 4179 4180 // first, check the condition. 4181 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4182 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4183 << CondTy; 4184 return QualType(); 4185 } 4186 4187 // Now check the two expressions. 4188 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4189 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4190 4191 // If both operands have arithmetic type, do the usual arithmetic conversions 4192 // to find a common type: C99 6.5.15p3,5. 4193 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4194 UsualArithmeticConversions(LHS, RHS); 4195 return LHS->getType(); 4196 } 4197 4198 // If both operands are the same structure or union type, the result is that 4199 // type. 4200 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4201 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4202 if (LHSRT->getDecl() == RHSRT->getDecl()) 4203 // "If both the operands have structure or union type, the result has 4204 // that type." This implies that CV qualifiers are dropped. 4205 return LHSTy.getUnqualifiedType(); 4206 // FIXME: Type of conditional expression must be complete in C mode. 4207 } 4208 4209 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4210 // The following || allows only one side to be void (a GCC-ism). 4211 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4212 if (!LHSTy->isVoidType()) 4213 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4214 << RHS->getSourceRange(); 4215 if (!RHSTy->isVoidType()) 4216 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4217 << LHS->getSourceRange(); 4218 ImpCastExprToType(LHS, Context.VoidTy, CastExpr::CK_ToVoid); 4219 ImpCastExprToType(RHS, Context.VoidTy, CastExpr::CK_ToVoid); 4220 return Context.VoidTy; 4221 } 4222 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4223 // the type of the other operand." 4224 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4225 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4226 // promote the null to a pointer. 4227 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_Unknown); 4228 return LHSTy; 4229 } 4230 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4231 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4232 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_Unknown); 4233 return RHSTy; 4234 } 4235 4236 // All objective-c pointer type analysis is done here. 4237 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4238 QuestionLoc); 4239 if (!compositeType.isNull()) 4240 return compositeType; 4241 4242 4243 // Handle block pointer types. 4244 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4245 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4246 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4247 QualType destType = Context.getPointerType(Context.VoidTy); 4248 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4249 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4250 return destType; 4251 } 4252 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4253 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4254 return QualType(); 4255 } 4256 // We have 2 block pointer types. 4257 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4258 // Two identical block pointer types are always compatible. 4259 return LHSTy; 4260 } 4261 // The block pointer types aren't identical, continue checking. 4262 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4263 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4264 4265 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4266 rhptee.getUnqualifiedType())) { 4267 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4268 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4269 // In this situation, we assume void* type. No especially good 4270 // reason, but this is what gcc does, and we do have to pick 4271 // to get a consistent AST. 4272 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4273 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4274 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4275 return incompatTy; 4276 } 4277 // The block pointer types are compatible. 4278 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4279 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4280 return LHSTy; 4281 } 4282 4283 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4284 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4285 // get the "pointed to" types 4286 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4287 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4288 4289 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4290 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4291 // Figure out necessary qualifiers (C99 6.5.15p6) 4292 QualType destPointee 4293 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4294 QualType destType = Context.getPointerType(destPointee); 4295 // Add qualifiers if necessary. 4296 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4297 // Promote to void*. 4298 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4299 return destType; 4300 } 4301 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4302 QualType destPointee 4303 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4304 QualType destType = Context.getPointerType(destPointee); 4305 // Add qualifiers if necessary. 4306 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4307 // Promote to void*. 4308 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4309 return destType; 4310 } 4311 4312 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4313 // Two identical pointer types are always compatible. 4314 return LHSTy; 4315 } 4316 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4317 rhptee.getUnqualifiedType())) { 4318 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4319 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4320 // In this situation, we assume void* type. No especially good 4321 // reason, but this is what gcc does, and we do have to pick 4322 // to get a consistent AST. 4323 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4324 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4325 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4326 return incompatTy; 4327 } 4328 // The pointer types are compatible. 4329 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4330 // differently qualified versions of compatible types, the result type is 4331 // a pointer to an appropriately qualified version of the *composite* 4332 // type. 4333 // FIXME: Need to calculate the composite type. 4334 // FIXME: Need to add qualifiers 4335 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4336 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4337 return LHSTy; 4338 } 4339 4340 // GCC compatibility: soften pointer/integer mismatch. 4341 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4342 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4343 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4344 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_IntegralToPointer); 4345 return RHSTy; 4346 } 4347 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4348 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4349 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4350 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_IntegralToPointer); 4351 return LHSTy; 4352 } 4353 4354 // Otherwise, the operands are not compatible. 4355 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4356 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4357 return QualType(); 4358} 4359 4360/// FindCompositeObjCPointerType - Helper method to find composite type of 4361/// two objective-c pointer types of the two input expressions. 4362QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4363 SourceLocation QuestionLoc) { 4364 QualType LHSTy = LHS->getType(); 4365 QualType RHSTy = RHS->getType(); 4366 4367 // Handle things like Class and struct objc_class*. Here we case the result 4368 // to the pseudo-builtin, because that will be implicitly cast back to the 4369 // redefinition type if an attempt is made to access its fields. 4370 if (LHSTy->isObjCClassType() && 4371 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4372 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4373 return LHSTy; 4374 } 4375 if (RHSTy->isObjCClassType() && 4376 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4377 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4378 return RHSTy; 4379 } 4380 // And the same for struct objc_object* / id 4381 if (LHSTy->isObjCIdType() && 4382 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4383 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4384 return LHSTy; 4385 } 4386 if (RHSTy->isObjCIdType() && 4387 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4388 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4389 return RHSTy; 4390 } 4391 // And the same for struct objc_selector* / SEL 4392 if (Context.isObjCSelType(LHSTy) && 4393 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4394 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4395 return LHSTy; 4396 } 4397 if (Context.isObjCSelType(RHSTy) && 4398 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4399 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4400 return RHSTy; 4401 } 4402 // Check constraints for Objective-C object pointers types. 4403 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4404 4405 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4406 // Two identical object pointer types are always compatible. 4407 return LHSTy; 4408 } 4409 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4410 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4411 QualType compositeType = LHSTy; 4412 4413 // If both operands are interfaces and either operand can be 4414 // assigned to the other, use that type as the composite 4415 // type. This allows 4416 // xxx ? (A*) a : (B*) b 4417 // where B is a subclass of A. 4418 // 4419 // Additionally, as for assignment, if either type is 'id' 4420 // allow silent coercion. Finally, if the types are 4421 // incompatible then make sure to use 'id' as the composite 4422 // type so the result is acceptable for sending messages to. 4423 4424 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4425 // It could return the composite type. 4426 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4427 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4428 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4429 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4430 } else if ((LHSTy->isObjCQualifiedIdType() || 4431 RHSTy->isObjCQualifiedIdType()) && 4432 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4433 // Need to handle "id<xx>" explicitly. 4434 // GCC allows qualified id and any Objective-C type to devolve to 4435 // id. Currently localizing to here until clear this should be 4436 // part of ObjCQualifiedIdTypesAreCompatible. 4437 compositeType = Context.getObjCIdType(); 4438 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4439 compositeType = Context.getObjCIdType(); 4440 } else if (!(compositeType = 4441 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4442 ; 4443 else { 4444 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4445 << LHSTy << RHSTy 4446 << LHS->getSourceRange() << RHS->getSourceRange(); 4447 QualType incompatTy = Context.getObjCIdType(); 4448 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4449 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4450 return incompatTy; 4451 } 4452 // The object pointer types are compatible. 4453 ImpCastExprToType(LHS, compositeType, CastExpr::CK_BitCast); 4454 ImpCastExprToType(RHS, compositeType, CastExpr::CK_BitCast); 4455 return compositeType; 4456 } 4457 // Check Objective-C object pointer types and 'void *' 4458 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4459 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4460 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4461 QualType destPointee 4462 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4463 QualType destType = Context.getPointerType(destPointee); 4464 // Add qualifiers if necessary. 4465 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4466 // Promote to void*. 4467 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4468 return destType; 4469 } 4470 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4471 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4472 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4473 QualType destPointee 4474 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4475 QualType destType = Context.getPointerType(destPointee); 4476 // Add qualifiers if necessary. 4477 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4478 // Promote to void*. 4479 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4480 return destType; 4481 } 4482 return QualType(); 4483} 4484 4485/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4486/// in the case of a the GNU conditional expr extension. 4487Action::OwningExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4488 SourceLocation ColonLoc, 4489 ExprArg Cond, ExprArg LHS, 4490 ExprArg RHS) { 4491 Expr *CondExpr = (Expr *) Cond.get(); 4492 Expr *LHSExpr = (Expr *) LHS.get(), *RHSExpr = (Expr *) RHS.get(); 4493 4494 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4495 // was the condition. 4496 bool isLHSNull = LHSExpr == 0; 4497 if (isLHSNull) 4498 LHSExpr = CondExpr; 4499 4500 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4501 RHSExpr, QuestionLoc); 4502 if (result.isNull()) 4503 return ExprError(); 4504 4505 Cond.release(); 4506 LHS.release(); 4507 RHS.release(); 4508 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4509 isLHSNull ? 0 : LHSExpr, 4510 ColonLoc, RHSExpr, result)); 4511} 4512 4513// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4514// being closely modeled after the C99 spec:-). The odd characteristic of this 4515// routine is it effectively iqnores the qualifiers on the top level pointee. 4516// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4517// FIXME: add a couple examples in this comment. 4518Sema::AssignConvertType 4519Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4520 QualType lhptee, rhptee; 4521 4522 if ((lhsType->isObjCClassType() && 4523 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4524 (rhsType->isObjCClassType() && 4525 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4526 return Compatible; 4527 } 4528 4529 // get the "pointed to" type (ignoring qualifiers at the top level) 4530 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4531 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4532 4533 // make sure we operate on the canonical type 4534 lhptee = Context.getCanonicalType(lhptee); 4535 rhptee = Context.getCanonicalType(rhptee); 4536 4537 AssignConvertType ConvTy = Compatible; 4538 4539 // C99 6.5.16.1p1: This following citation is common to constraints 4540 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4541 // qualifiers of the type *pointed to* by the right; 4542 // FIXME: Handle ExtQualType 4543 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4544 ConvTy = CompatiblePointerDiscardsQualifiers; 4545 4546 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4547 // incomplete type and the other is a pointer to a qualified or unqualified 4548 // version of void... 4549 if (lhptee->isVoidType()) { 4550 if (rhptee->isIncompleteOrObjectType()) 4551 return ConvTy; 4552 4553 // As an extension, we allow cast to/from void* to function pointer. 4554 assert(rhptee->isFunctionType()); 4555 return FunctionVoidPointer; 4556 } 4557 4558 if (rhptee->isVoidType()) { 4559 if (lhptee->isIncompleteOrObjectType()) 4560 return ConvTy; 4561 4562 // As an extension, we allow cast to/from void* to function pointer. 4563 assert(lhptee->isFunctionType()); 4564 return FunctionVoidPointer; 4565 } 4566 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4567 // unqualified versions of compatible types, ... 4568 lhptee = lhptee.getUnqualifiedType(); 4569 rhptee = rhptee.getUnqualifiedType(); 4570 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4571 // Check if the pointee types are compatible ignoring the sign. 4572 // We explicitly check for char so that we catch "char" vs 4573 // "unsigned char" on systems where "char" is unsigned. 4574 if (lhptee->isCharType()) 4575 lhptee = Context.UnsignedCharTy; 4576 else if (lhptee->isSignedIntegerType()) 4577 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4578 4579 if (rhptee->isCharType()) 4580 rhptee = Context.UnsignedCharTy; 4581 else if (rhptee->isSignedIntegerType()) 4582 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4583 4584 if (lhptee == rhptee) { 4585 // Types are compatible ignoring the sign. Qualifier incompatibility 4586 // takes priority over sign incompatibility because the sign 4587 // warning can be disabled. 4588 if (ConvTy != Compatible) 4589 return ConvTy; 4590 return IncompatiblePointerSign; 4591 } 4592 4593 // If we are a multi-level pointer, it's possible that our issue is simply 4594 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4595 // the eventual target type is the same and the pointers have the same 4596 // level of indirection, this must be the issue. 4597 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4598 do { 4599 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4600 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4601 4602 lhptee = Context.getCanonicalType(lhptee); 4603 rhptee = Context.getCanonicalType(rhptee); 4604 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4605 4606 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4607 return IncompatibleNestedPointerQualifiers; 4608 } 4609 4610 // General pointer incompatibility takes priority over qualifiers. 4611 return IncompatiblePointer; 4612 } 4613 return ConvTy; 4614} 4615 4616/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4617/// block pointer types are compatible or whether a block and normal pointer 4618/// are compatible. It is more restrict than comparing two function pointer 4619// types. 4620Sema::AssignConvertType 4621Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4622 QualType rhsType) { 4623 QualType lhptee, rhptee; 4624 4625 // get the "pointed to" type (ignoring qualifiers at the top level) 4626 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4627 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4628 4629 // make sure we operate on the canonical type 4630 lhptee = Context.getCanonicalType(lhptee); 4631 rhptee = Context.getCanonicalType(rhptee); 4632 4633 AssignConvertType ConvTy = Compatible; 4634 4635 // For blocks we enforce that qualifiers are identical. 4636 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4637 ConvTy = CompatiblePointerDiscardsQualifiers; 4638 4639 if (!getLangOptions().CPlusPlus) { 4640 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4641 return IncompatibleBlockPointer; 4642 } 4643 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4644 return IncompatibleBlockPointer; 4645 return ConvTy; 4646} 4647 4648/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4649/// for assignment compatibility. 4650Sema::AssignConvertType 4651Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4652 if (lhsType->isObjCBuiltinType()) { 4653 // Class is not compatible with ObjC object pointers. 4654 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4655 !rhsType->isObjCQualifiedClassType()) 4656 return IncompatiblePointer; 4657 return Compatible; 4658 } 4659 if (rhsType->isObjCBuiltinType()) { 4660 // Class is not compatible with ObjC object pointers. 4661 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4662 !lhsType->isObjCQualifiedClassType()) 4663 return IncompatiblePointer; 4664 return Compatible; 4665 } 4666 QualType lhptee = 4667 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4668 QualType rhptee = 4669 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4670 // make sure we operate on the canonical type 4671 lhptee = Context.getCanonicalType(lhptee); 4672 rhptee = Context.getCanonicalType(rhptee); 4673 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4674 return CompatiblePointerDiscardsQualifiers; 4675 4676 if (Context.typesAreCompatible(lhsType, rhsType)) 4677 return Compatible; 4678 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4679 return IncompatibleObjCQualifiedId; 4680 return IncompatiblePointer; 4681} 4682 4683/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4684/// has code to accommodate several GCC extensions when type checking 4685/// pointers. Here are some objectionable examples that GCC considers warnings: 4686/// 4687/// int a, *pint; 4688/// short *pshort; 4689/// struct foo *pfoo; 4690/// 4691/// pint = pshort; // warning: assignment from incompatible pointer type 4692/// a = pint; // warning: assignment makes integer from pointer without a cast 4693/// pint = a; // warning: assignment makes pointer from integer without a cast 4694/// pint = pfoo; // warning: assignment from incompatible pointer type 4695/// 4696/// As a result, the code for dealing with pointers is more complex than the 4697/// C99 spec dictates. 4698/// 4699Sema::AssignConvertType 4700Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4701 // Get canonical types. We're not formatting these types, just comparing 4702 // them. 4703 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4704 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4705 4706 if (lhsType == rhsType) 4707 return Compatible; // Common case: fast path an exact match. 4708 4709 if ((lhsType->isObjCClassType() && 4710 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4711 (rhsType->isObjCClassType() && 4712 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4713 return Compatible; 4714 } 4715 4716 // If the left-hand side is a reference type, then we are in a 4717 // (rare!) case where we've allowed the use of references in C, 4718 // e.g., as a parameter type in a built-in function. In this case, 4719 // just make sure that the type referenced is compatible with the 4720 // right-hand side type. The caller is responsible for adjusting 4721 // lhsType so that the resulting expression does not have reference 4722 // type. 4723 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4724 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4725 return Compatible; 4726 return Incompatible; 4727 } 4728 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4729 // to the same ExtVector type. 4730 if (lhsType->isExtVectorType()) { 4731 if (rhsType->isExtVectorType()) 4732 return lhsType == rhsType ? Compatible : Incompatible; 4733 if (!rhsType->isVectorType() && rhsType->isArithmeticType()) 4734 return Compatible; 4735 } 4736 4737 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4738 // If we are allowing lax vector conversions, and LHS and RHS are both 4739 // vectors, the total size only needs to be the same. This is a bitcast; 4740 // no bits are changed but the result type is different. 4741 if (getLangOptions().LaxVectorConversions && 4742 lhsType->isVectorType() && rhsType->isVectorType()) { 4743 if (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType)) 4744 return IncompatibleVectors; 4745 } 4746 return Incompatible; 4747 } 4748 4749 if (lhsType->isArithmeticType() && rhsType->isArithmeticType()) 4750 return Compatible; 4751 4752 if (isa<PointerType>(lhsType)) { 4753 if (rhsType->isIntegerType()) 4754 return IntToPointer; 4755 4756 if (isa<PointerType>(rhsType)) 4757 return CheckPointerTypesForAssignment(lhsType, rhsType); 4758 4759 // In general, C pointers are not compatible with ObjC object pointers. 4760 if (isa<ObjCObjectPointerType>(rhsType)) { 4761 if (lhsType->isVoidPointerType()) // an exception to the rule. 4762 return Compatible; 4763 return IncompatiblePointer; 4764 } 4765 if (rhsType->getAs<BlockPointerType>()) { 4766 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4767 return Compatible; 4768 4769 // Treat block pointers as objects. 4770 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4771 return Compatible; 4772 } 4773 return Incompatible; 4774 } 4775 4776 if (isa<BlockPointerType>(lhsType)) { 4777 if (rhsType->isIntegerType()) 4778 return IntToBlockPointer; 4779 4780 // Treat block pointers as objects. 4781 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4782 return Compatible; 4783 4784 if (rhsType->isBlockPointerType()) 4785 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4786 4787 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4788 if (RHSPT->getPointeeType()->isVoidType()) 4789 return Compatible; 4790 } 4791 return Incompatible; 4792 } 4793 4794 if (isa<ObjCObjectPointerType>(lhsType)) { 4795 if (rhsType->isIntegerType()) 4796 return IntToPointer; 4797 4798 // In general, C pointers are not compatible with ObjC object pointers. 4799 if (isa<PointerType>(rhsType)) { 4800 if (rhsType->isVoidPointerType()) // an exception to the rule. 4801 return Compatible; 4802 return IncompatiblePointer; 4803 } 4804 if (rhsType->isObjCObjectPointerType()) { 4805 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4806 } 4807 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4808 if (RHSPT->getPointeeType()->isVoidType()) 4809 return Compatible; 4810 } 4811 // Treat block pointers as objects. 4812 if (rhsType->isBlockPointerType()) 4813 return Compatible; 4814 return Incompatible; 4815 } 4816 if (isa<PointerType>(rhsType)) { 4817 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4818 if (lhsType == Context.BoolTy) 4819 return Compatible; 4820 4821 if (lhsType->isIntegerType()) 4822 return PointerToInt; 4823 4824 if (isa<PointerType>(lhsType)) 4825 return CheckPointerTypesForAssignment(lhsType, rhsType); 4826 4827 if (isa<BlockPointerType>(lhsType) && 4828 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4829 return Compatible; 4830 return Incompatible; 4831 } 4832 if (isa<ObjCObjectPointerType>(rhsType)) { 4833 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4834 if (lhsType == Context.BoolTy) 4835 return Compatible; 4836 4837 if (lhsType->isIntegerType()) 4838 return PointerToInt; 4839 4840 // In general, C pointers are not compatible with ObjC object pointers. 4841 if (isa<PointerType>(lhsType)) { 4842 if (lhsType->isVoidPointerType()) // an exception to the rule. 4843 return Compatible; 4844 return IncompatiblePointer; 4845 } 4846 if (isa<BlockPointerType>(lhsType) && 4847 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4848 return Compatible; 4849 return Incompatible; 4850 } 4851 4852 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4853 if (Context.typesAreCompatible(lhsType, rhsType)) 4854 return Compatible; 4855 } 4856 return Incompatible; 4857} 4858 4859/// \brief Constructs a transparent union from an expression that is 4860/// used to initialize the transparent union. 4861static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4862 QualType UnionType, FieldDecl *Field) { 4863 // Build an initializer list that designates the appropriate member 4864 // of the transparent union. 4865 InitListExpr *Initializer = new (C) InitListExpr(SourceLocation(), 4866 &E, 1, 4867 SourceLocation()); 4868 Initializer->setType(UnionType); 4869 Initializer->setInitializedFieldInUnion(Field); 4870 4871 // Build a compound literal constructing a value of the transparent 4872 // union type from this initializer list. 4873 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4874 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4875 Initializer, false); 4876} 4877 4878Sema::AssignConvertType 4879Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4880 QualType FromType = rExpr->getType(); 4881 4882 // If the ArgType is a Union type, we want to handle a potential 4883 // transparent_union GCC extension. 4884 const RecordType *UT = ArgType->getAsUnionType(); 4885 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4886 return Incompatible; 4887 4888 // The field to initialize within the transparent union. 4889 RecordDecl *UD = UT->getDecl(); 4890 FieldDecl *InitField = 0; 4891 // It's compatible if the expression matches any of the fields. 4892 for (RecordDecl::field_iterator it = UD->field_begin(), 4893 itend = UD->field_end(); 4894 it != itend; ++it) { 4895 if (it->getType()->isPointerType()) { 4896 // If the transparent union contains a pointer type, we allow: 4897 // 1) void pointer 4898 // 2) null pointer constant 4899 if (FromType->isPointerType()) 4900 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4901 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_BitCast); 4902 InitField = *it; 4903 break; 4904 } 4905 4906 if (rExpr->isNullPointerConstant(Context, 4907 Expr::NPC_ValueDependentIsNull)) { 4908 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_IntegralToPointer); 4909 InitField = *it; 4910 break; 4911 } 4912 } 4913 4914 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4915 == Compatible) { 4916 InitField = *it; 4917 break; 4918 } 4919 } 4920 4921 if (!InitField) 4922 return Incompatible; 4923 4924 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4925 return Compatible; 4926} 4927 4928Sema::AssignConvertType 4929Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4930 if (getLangOptions().CPlusPlus) { 4931 if (!lhsType->isRecordType()) { 4932 // C++ 5.17p3: If the left operand is not of class type, the 4933 // expression is implicitly converted (C++ 4) to the 4934 // cv-unqualified type of the left operand. 4935 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4936 AA_Assigning)) 4937 return Incompatible; 4938 return Compatible; 4939 } 4940 4941 // FIXME: Currently, we fall through and treat C++ classes like C 4942 // structures. 4943 } 4944 4945 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4946 // a null pointer constant. 4947 if ((lhsType->isPointerType() || 4948 lhsType->isObjCObjectPointerType() || 4949 lhsType->isBlockPointerType()) 4950 && rExpr->isNullPointerConstant(Context, 4951 Expr::NPC_ValueDependentIsNull)) { 4952 ImpCastExprToType(rExpr, lhsType, CastExpr::CK_Unknown); 4953 return Compatible; 4954 } 4955 4956 // This check seems unnatural, however it is necessary to ensure the proper 4957 // conversion of functions/arrays. If the conversion were done for all 4958 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4959 // expressions that surpress this implicit conversion (&, sizeof). 4960 // 4961 // Suppress this for references: C++ 8.5.3p5. 4962 if (!lhsType->isReferenceType()) 4963 DefaultFunctionArrayLvalueConversion(rExpr); 4964 4965 Sema::AssignConvertType result = 4966 CheckAssignmentConstraints(lhsType, rExpr->getType()); 4967 4968 // C99 6.5.16.1p2: The value of the right operand is converted to the 4969 // type of the assignment expression. 4970 // CheckAssignmentConstraints allows the left-hand side to be a reference, 4971 // so that we can use references in built-in functions even in C. 4972 // The getNonReferenceType() call makes sure that the resulting expression 4973 // does not have reference type. 4974 if (result != Incompatible && rExpr->getType() != lhsType) 4975 ImpCastExprToType(rExpr, lhsType.getNonReferenceType(), 4976 CastExpr::CK_Unknown); 4977 return result; 4978} 4979 4980QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4981 Diag(Loc, diag::err_typecheck_invalid_operands) 4982 << lex->getType() << rex->getType() 4983 << lex->getSourceRange() << rex->getSourceRange(); 4984 return QualType(); 4985} 4986 4987QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4988 // For conversion purposes, we ignore any qualifiers. 4989 // For example, "const float" and "float" are equivalent. 4990 QualType lhsType = 4991 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 4992 QualType rhsType = 4993 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 4994 4995 // If the vector types are identical, return. 4996 if (lhsType == rhsType) 4997 return lhsType; 4998 4999 // Handle the case of a vector & extvector type of the same size and element 5000 // type. It would be nice if we only had one vector type someday. 5001 if (getLangOptions().LaxVectorConversions) { 5002 // FIXME: Should we warn here? 5003 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5004 if (const VectorType *RV = rhsType->getAs<VectorType>()) 5005 if (LV->getElementType() == RV->getElementType() && 5006 LV->getNumElements() == RV->getNumElements()) { 5007 return lhsType->isExtVectorType() ? lhsType : rhsType; 5008 } 5009 } 5010 } 5011 5012 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5013 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5014 bool swapped = false; 5015 if (rhsType->isExtVectorType()) { 5016 swapped = true; 5017 std::swap(rex, lex); 5018 std::swap(rhsType, lhsType); 5019 } 5020 5021 // Handle the case of an ext vector and scalar. 5022 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5023 QualType EltTy = LV->getElementType(); 5024 if (EltTy->isIntegralType() && rhsType->isIntegralType()) { 5025 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5026 ImpCastExprToType(rex, lhsType, CastExpr::CK_IntegralCast); 5027 if (swapped) std::swap(rex, lex); 5028 return lhsType; 5029 } 5030 } 5031 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5032 rhsType->isRealFloatingType()) { 5033 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5034 ImpCastExprToType(rex, lhsType, CastExpr::CK_FloatingCast); 5035 if (swapped) std::swap(rex, lex); 5036 return lhsType; 5037 } 5038 } 5039 } 5040 5041 // Vectors of different size or scalar and non-ext-vector are errors. 5042 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5043 << lex->getType() << rex->getType() 5044 << lex->getSourceRange() << rex->getSourceRange(); 5045 return QualType(); 5046} 5047 5048QualType Sema::CheckMultiplyDivideOperands( 5049 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5050 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5051 return CheckVectorOperands(Loc, lex, rex); 5052 5053 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5054 5055 if (!lex->getType()->isArithmeticType() || 5056 !rex->getType()->isArithmeticType()) 5057 return InvalidOperands(Loc, lex, rex); 5058 5059 // Check for division by zero. 5060 if (isDiv && 5061 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5062 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5063 << rex->getSourceRange()); 5064 5065 return compType; 5066} 5067 5068QualType Sema::CheckRemainderOperands( 5069 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5070 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5071 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5072 return CheckVectorOperands(Loc, lex, rex); 5073 return InvalidOperands(Loc, lex, rex); 5074 } 5075 5076 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5077 5078 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5079 return InvalidOperands(Loc, lex, rex); 5080 5081 // Check for remainder by zero. 5082 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5083 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5084 << rex->getSourceRange()); 5085 5086 return compType; 5087} 5088 5089QualType Sema::CheckAdditionOperands( // C99 6.5.6 5090 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5091 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5092 QualType compType = CheckVectorOperands(Loc, lex, rex); 5093 if (CompLHSTy) *CompLHSTy = compType; 5094 return compType; 5095 } 5096 5097 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5098 5099 // handle the common case first (both operands are arithmetic). 5100 if (lex->getType()->isArithmeticType() && 5101 rex->getType()->isArithmeticType()) { 5102 if (CompLHSTy) *CompLHSTy = compType; 5103 return compType; 5104 } 5105 5106 // Put any potential pointer into PExp 5107 Expr* PExp = lex, *IExp = rex; 5108 if (IExp->getType()->isAnyPointerType()) 5109 std::swap(PExp, IExp); 5110 5111 if (PExp->getType()->isAnyPointerType()) { 5112 5113 if (IExp->getType()->isIntegerType()) { 5114 QualType PointeeTy = PExp->getType()->getPointeeType(); 5115 5116 // Check for arithmetic on pointers to incomplete types. 5117 if (PointeeTy->isVoidType()) { 5118 if (getLangOptions().CPlusPlus) { 5119 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5120 << lex->getSourceRange() << rex->getSourceRange(); 5121 return QualType(); 5122 } 5123 5124 // GNU extension: arithmetic on pointer to void 5125 Diag(Loc, diag::ext_gnu_void_ptr) 5126 << lex->getSourceRange() << rex->getSourceRange(); 5127 } else if (PointeeTy->isFunctionType()) { 5128 if (getLangOptions().CPlusPlus) { 5129 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5130 << lex->getType() << lex->getSourceRange(); 5131 return QualType(); 5132 } 5133 5134 // GNU extension: arithmetic on pointer to function 5135 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5136 << lex->getType() << lex->getSourceRange(); 5137 } else { 5138 // Check if we require a complete type. 5139 if (((PExp->getType()->isPointerType() && 5140 !PExp->getType()->isDependentType()) || 5141 PExp->getType()->isObjCObjectPointerType()) && 5142 RequireCompleteType(Loc, PointeeTy, 5143 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5144 << PExp->getSourceRange() 5145 << PExp->getType())) 5146 return QualType(); 5147 } 5148 // Diagnose bad cases where we step over interface counts. 5149 if (PointeeTy->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 5150 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5151 << PointeeTy << PExp->getSourceRange(); 5152 return QualType(); 5153 } 5154 5155 if (CompLHSTy) { 5156 QualType LHSTy = Context.isPromotableBitField(lex); 5157 if (LHSTy.isNull()) { 5158 LHSTy = lex->getType(); 5159 if (LHSTy->isPromotableIntegerType()) 5160 LHSTy = Context.getPromotedIntegerType(LHSTy); 5161 } 5162 *CompLHSTy = LHSTy; 5163 } 5164 return PExp->getType(); 5165 } 5166 } 5167 5168 return InvalidOperands(Loc, lex, rex); 5169} 5170 5171// C99 6.5.6 5172QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5173 SourceLocation Loc, QualType* CompLHSTy) { 5174 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5175 QualType compType = CheckVectorOperands(Loc, lex, rex); 5176 if (CompLHSTy) *CompLHSTy = compType; 5177 return compType; 5178 } 5179 5180 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5181 5182 // Enforce type constraints: C99 6.5.6p3. 5183 5184 // Handle the common case first (both operands are arithmetic). 5185 if (lex->getType()->isArithmeticType() 5186 && rex->getType()->isArithmeticType()) { 5187 if (CompLHSTy) *CompLHSTy = compType; 5188 return compType; 5189 } 5190 5191 // Either ptr - int or ptr - ptr. 5192 if (lex->getType()->isAnyPointerType()) { 5193 QualType lpointee = lex->getType()->getPointeeType(); 5194 5195 // The LHS must be an completely-defined object type. 5196 5197 bool ComplainAboutVoid = false; 5198 Expr *ComplainAboutFunc = 0; 5199 if (lpointee->isVoidType()) { 5200 if (getLangOptions().CPlusPlus) { 5201 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5202 << lex->getSourceRange() << rex->getSourceRange(); 5203 return QualType(); 5204 } 5205 5206 // GNU C extension: arithmetic on pointer to void 5207 ComplainAboutVoid = true; 5208 } else if (lpointee->isFunctionType()) { 5209 if (getLangOptions().CPlusPlus) { 5210 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5211 << lex->getType() << lex->getSourceRange(); 5212 return QualType(); 5213 } 5214 5215 // GNU C extension: arithmetic on pointer to function 5216 ComplainAboutFunc = lex; 5217 } else if (!lpointee->isDependentType() && 5218 RequireCompleteType(Loc, lpointee, 5219 PDiag(diag::err_typecheck_sub_ptr_object) 5220 << lex->getSourceRange() 5221 << lex->getType())) 5222 return QualType(); 5223 5224 // Diagnose bad cases where we step over interface counts. 5225 if (lpointee->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 5226 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5227 << lpointee << lex->getSourceRange(); 5228 return QualType(); 5229 } 5230 5231 // The result type of a pointer-int computation is the pointer type. 5232 if (rex->getType()->isIntegerType()) { 5233 if (ComplainAboutVoid) 5234 Diag(Loc, diag::ext_gnu_void_ptr) 5235 << lex->getSourceRange() << rex->getSourceRange(); 5236 if (ComplainAboutFunc) 5237 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5238 << ComplainAboutFunc->getType() 5239 << ComplainAboutFunc->getSourceRange(); 5240 5241 if (CompLHSTy) *CompLHSTy = lex->getType(); 5242 return lex->getType(); 5243 } 5244 5245 // Handle pointer-pointer subtractions. 5246 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5247 QualType rpointee = RHSPTy->getPointeeType(); 5248 5249 // RHS must be a completely-type object type. 5250 // Handle the GNU void* extension. 5251 if (rpointee->isVoidType()) { 5252 if (getLangOptions().CPlusPlus) { 5253 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5254 << lex->getSourceRange() << rex->getSourceRange(); 5255 return QualType(); 5256 } 5257 5258 ComplainAboutVoid = true; 5259 } else if (rpointee->isFunctionType()) { 5260 if (getLangOptions().CPlusPlus) { 5261 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5262 << rex->getType() << rex->getSourceRange(); 5263 return QualType(); 5264 } 5265 5266 // GNU extension: arithmetic on pointer to function 5267 if (!ComplainAboutFunc) 5268 ComplainAboutFunc = rex; 5269 } else if (!rpointee->isDependentType() && 5270 RequireCompleteType(Loc, rpointee, 5271 PDiag(diag::err_typecheck_sub_ptr_object) 5272 << rex->getSourceRange() 5273 << rex->getType())) 5274 return QualType(); 5275 5276 if (getLangOptions().CPlusPlus) { 5277 // Pointee types must be the same: C++ [expr.add] 5278 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5279 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5280 << lex->getType() << rex->getType() 5281 << lex->getSourceRange() << rex->getSourceRange(); 5282 return QualType(); 5283 } 5284 } else { 5285 // Pointee types must be compatible C99 6.5.6p3 5286 if (!Context.typesAreCompatible( 5287 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5288 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5289 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5290 << lex->getType() << rex->getType() 5291 << lex->getSourceRange() << rex->getSourceRange(); 5292 return QualType(); 5293 } 5294 } 5295 5296 if (ComplainAboutVoid) 5297 Diag(Loc, diag::ext_gnu_void_ptr) 5298 << lex->getSourceRange() << rex->getSourceRange(); 5299 if (ComplainAboutFunc) 5300 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5301 << ComplainAboutFunc->getType() 5302 << ComplainAboutFunc->getSourceRange(); 5303 5304 if (CompLHSTy) *CompLHSTy = lex->getType(); 5305 return Context.getPointerDiffType(); 5306 } 5307 } 5308 5309 return InvalidOperands(Loc, lex, rex); 5310} 5311 5312// C99 6.5.7 5313QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5314 bool isCompAssign) { 5315 // C99 6.5.7p2: Each of the operands shall have integer type. 5316 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5317 return InvalidOperands(Loc, lex, rex); 5318 5319 // Vector shifts promote their scalar inputs to vector type. 5320 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5321 return CheckVectorOperands(Loc, lex, rex); 5322 5323 // Shifts don't perform usual arithmetic conversions, they just do integer 5324 // promotions on each operand. C99 6.5.7p3 5325 QualType LHSTy = Context.isPromotableBitField(lex); 5326 if (LHSTy.isNull()) { 5327 LHSTy = lex->getType(); 5328 if (LHSTy->isPromotableIntegerType()) 5329 LHSTy = Context.getPromotedIntegerType(LHSTy); 5330 } 5331 if (!isCompAssign) 5332 ImpCastExprToType(lex, LHSTy, CastExpr::CK_IntegralCast); 5333 5334 UsualUnaryConversions(rex); 5335 5336 // Sanity-check shift operands 5337 llvm::APSInt Right; 5338 // Check right/shifter operand 5339 if (!rex->isValueDependent() && 5340 rex->isIntegerConstantExpr(Right, Context)) { 5341 if (Right.isNegative()) 5342 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5343 else { 5344 llvm::APInt LeftBits(Right.getBitWidth(), 5345 Context.getTypeSize(lex->getType())); 5346 if (Right.uge(LeftBits)) 5347 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5348 } 5349 } 5350 5351 // "The type of the result is that of the promoted left operand." 5352 return LHSTy; 5353} 5354 5355// C99 6.5.8, C++ [expr.rel] 5356QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5357 unsigned OpaqueOpc, bool isRelational) { 5358 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)OpaqueOpc; 5359 5360 // Handle vector comparisons separately. 5361 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5362 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5363 5364 CheckSignCompare(lex, rex, Loc, &Opc); 5365 5366 // C99 6.5.8p3 / C99 6.5.9p4 5367 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5368 UsualArithmeticConversions(lex, rex); 5369 else { 5370 UsualUnaryConversions(lex); 5371 UsualUnaryConversions(rex); 5372 } 5373 QualType lType = lex->getType(); 5374 QualType rType = rex->getType(); 5375 5376 if (!lType->isFloatingType() 5377 && !(lType->isBlockPointerType() && isRelational)) { 5378 // For non-floating point types, check for self-comparisons of the form 5379 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5380 // often indicate logic errors in the program. 5381 // NOTE: Don't warn about comparisons of enum constants. These can arise 5382 // from macro expansions, and are usually quite deliberate. 5383 Expr *LHSStripped = lex->IgnoreParens(); 5384 Expr *RHSStripped = rex->IgnoreParens(); 5385 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) 5386 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) 5387 if (DRL->getDecl() == DRR->getDecl() && 5388 !isa<EnumConstantDecl>(DRL->getDecl())) 5389 DiagRuntimeBehavior(Loc, PDiag(diag::warn_selfcomparison)); 5390 5391 if (isa<CastExpr>(LHSStripped)) 5392 LHSStripped = LHSStripped->IgnoreParenCasts(); 5393 if (isa<CastExpr>(RHSStripped)) 5394 RHSStripped = RHSStripped->IgnoreParenCasts(); 5395 5396 // Warn about comparisons against a string constant (unless the other 5397 // operand is null), the user probably wants strcmp. 5398 Expr *literalString = 0; 5399 Expr *literalStringStripped = 0; 5400 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5401 !RHSStripped->isNullPointerConstant(Context, 5402 Expr::NPC_ValueDependentIsNull)) { 5403 literalString = lex; 5404 literalStringStripped = LHSStripped; 5405 } else if ((isa<StringLiteral>(RHSStripped) || 5406 isa<ObjCEncodeExpr>(RHSStripped)) && 5407 !LHSStripped->isNullPointerConstant(Context, 5408 Expr::NPC_ValueDependentIsNull)) { 5409 literalString = rex; 5410 literalStringStripped = RHSStripped; 5411 } 5412 5413 if (literalString) { 5414 std::string resultComparison; 5415 switch (Opc) { 5416 case BinaryOperator::LT: resultComparison = ") < 0"; break; 5417 case BinaryOperator::GT: resultComparison = ") > 0"; break; 5418 case BinaryOperator::LE: resultComparison = ") <= 0"; break; 5419 case BinaryOperator::GE: resultComparison = ") >= 0"; break; 5420 case BinaryOperator::EQ: resultComparison = ") == 0"; break; 5421 case BinaryOperator::NE: resultComparison = ") != 0"; break; 5422 default: assert(false && "Invalid comparison operator"); 5423 } 5424 5425 DiagRuntimeBehavior(Loc, 5426 PDiag(diag::warn_stringcompare) 5427 << isa<ObjCEncodeExpr>(literalStringStripped) 5428 << literalString->getSourceRange() 5429 << CodeModificationHint::CreateReplacement(SourceRange(Loc), ", ") 5430 << CodeModificationHint::CreateInsertion(lex->getLocStart(), 5431 "strcmp(") 5432 << CodeModificationHint::CreateInsertion( 5433 PP.getLocForEndOfToken(rex->getLocEnd()), 5434 resultComparison)); 5435 } 5436 } 5437 5438 // The result of comparisons is 'bool' in C++, 'int' in C. 5439 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5440 5441 if (isRelational) { 5442 if (lType->isRealType() && rType->isRealType()) 5443 return ResultTy; 5444 } else { 5445 // Check for comparisons of floating point operands using != and ==. 5446 if (lType->isFloatingType() && rType->isFloatingType()) 5447 CheckFloatComparison(Loc,lex,rex); 5448 5449 if (lType->isArithmeticType() && rType->isArithmeticType()) 5450 return ResultTy; 5451 } 5452 5453 bool LHSIsNull = lex->isNullPointerConstant(Context, 5454 Expr::NPC_ValueDependentIsNull); 5455 bool RHSIsNull = rex->isNullPointerConstant(Context, 5456 Expr::NPC_ValueDependentIsNull); 5457 5458 // All of the following pointer related warnings are GCC extensions, except 5459 // when handling null pointer constants. One day, we can consider making them 5460 // errors (when -pedantic-errors is enabled). 5461 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5462 QualType LCanPointeeTy = 5463 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5464 QualType RCanPointeeTy = 5465 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5466 5467 if (getLangOptions().CPlusPlus) { 5468 if (LCanPointeeTy == RCanPointeeTy) 5469 return ResultTy; 5470 if (!isRelational && 5471 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5472 // Valid unless comparison between non-null pointer and function pointer 5473 // This is a gcc extension compatibility comparison. 5474 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5475 && !LHSIsNull && !RHSIsNull) { 5476 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5477 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5478 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5479 return ResultTy; 5480 } 5481 } 5482 // C++ [expr.rel]p2: 5483 // [...] Pointer conversions (4.10) and qualification 5484 // conversions (4.4) are performed on pointer operands (or on 5485 // a pointer operand and a null pointer constant) to bring 5486 // them to their composite pointer type. [...] 5487 // 5488 // C++ [expr.eq]p1 uses the same notion for (in)equality 5489 // comparisons of pointers. 5490 bool NonStandardCompositeType = false; 5491 QualType T = FindCompositePointerType(lex, rex, 5492 isSFINAEContext()? 0 : &NonStandardCompositeType); 5493 if (T.isNull()) { 5494 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5495 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5496 return QualType(); 5497 } else if (NonStandardCompositeType) { 5498 Diag(Loc, 5499 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5500 << lType << rType << T 5501 << lex->getSourceRange() << rex->getSourceRange(); 5502 } 5503 5504 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5505 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5506 return ResultTy; 5507 } 5508 // C99 6.5.9p2 and C99 6.5.8p2 5509 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5510 RCanPointeeTy.getUnqualifiedType())) { 5511 // Valid unless a relational comparison of function pointers 5512 if (isRelational && LCanPointeeTy->isFunctionType()) { 5513 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5514 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5515 } 5516 } else if (!isRelational && 5517 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5518 // Valid unless comparison between non-null pointer and function pointer 5519 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5520 && !LHSIsNull && !RHSIsNull) { 5521 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5522 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5523 } 5524 } else { 5525 // Invalid 5526 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5527 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5528 } 5529 if (LCanPointeeTy != RCanPointeeTy) 5530 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5531 return ResultTy; 5532 } 5533 5534 if (getLangOptions().CPlusPlus) { 5535 // Comparison of pointers with null pointer constants and equality 5536 // comparisons of member pointers to null pointer constants. 5537 if (RHSIsNull && 5538 (lType->isPointerType() || 5539 (!isRelational && lType->isMemberPointerType()))) { 5540 ImpCastExprToType(rex, lType, CastExpr::CK_NullToMemberPointer); 5541 return ResultTy; 5542 } 5543 if (LHSIsNull && 5544 (rType->isPointerType() || 5545 (!isRelational && rType->isMemberPointerType()))) { 5546 ImpCastExprToType(lex, rType, CastExpr::CK_NullToMemberPointer); 5547 return ResultTy; 5548 } 5549 5550 // Comparison of member pointers. 5551 if (!isRelational && 5552 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5553 // C++ [expr.eq]p2: 5554 // In addition, pointers to members can be compared, or a pointer to 5555 // member and a null pointer constant. Pointer to member conversions 5556 // (4.11) and qualification conversions (4.4) are performed to bring 5557 // them to a common type. If one operand is a null pointer constant, 5558 // the common type is the type of the other operand. Otherwise, the 5559 // common type is a pointer to member type similar (4.4) to the type 5560 // of one of the operands, with a cv-qualification signature (4.4) 5561 // that is the union of the cv-qualification signatures of the operand 5562 // types. 5563 bool NonStandardCompositeType = false; 5564 QualType T = FindCompositePointerType(lex, rex, 5565 isSFINAEContext()? 0 : &NonStandardCompositeType); 5566 if (T.isNull()) { 5567 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5568 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5569 return QualType(); 5570 } else if (NonStandardCompositeType) { 5571 Diag(Loc, 5572 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5573 << lType << rType << T 5574 << lex->getSourceRange() << rex->getSourceRange(); 5575 } 5576 5577 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5578 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5579 return ResultTy; 5580 } 5581 5582 // Comparison of nullptr_t with itself. 5583 if (lType->isNullPtrType() && rType->isNullPtrType()) 5584 return ResultTy; 5585 } 5586 5587 // Handle block pointer types. 5588 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5589 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5590 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5591 5592 if (!LHSIsNull && !RHSIsNull && 5593 !Context.typesAreCompatible(lpointee, rpointee)) { 5594 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5595 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5596 } 5597 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5598 return ResultTy; 5599 } 5600 // Allow block pointers to be compared with null pointer constants. 5601 if (!isRelational 5602 && ((lType->isBlockPointerType() && rType->isPointerType()) 5603 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5604 if (!LHSIsNull && !RHSIsNull) { 5605 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5606 ->getPointeeType()->isVoidType()) 5607 || (lType->isPointerType() && lType->getAs<PointerType>() 5608 ->getPointeeType()->isVoidType()))) 5609 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5610 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5611 } 5612 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5613 return ResultTy; 5614 } 5615 5616 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5617 if (lType->isPointerType() || rType->isPointerType()) { 5618 const PointerType *LPT = lType->getAs<PointerType>(); 5619 const PointerType *RPT = rType->getAs<PointerType>(); 5620 bool LPtrToVoid = LPT ? 5621 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5622 bool RPtrToVoid = RPT ? 5623 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5624 5625 if (!LPtrToVoid && !RPtrToVoid && 5626 !Context.typesAreCompatible(lType, rType)) { 5627 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5628 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5629 } 5630 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5631 return ResultTy; 5632 } 5633 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5634 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5635 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5636 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5637 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5638 return ResultTy; 5639 } 5640 } 5641 if (lType->isAnyPointerType() && rType->isIntegerType()) { 5642 unsigned DiagID = 0; 5643 if (RHSIsNull) { 5644 if (isRelational) 5645 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5646 } else if (isRelational) 5647 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5648 else 5649 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5650 5651 if (DiagID) { 5652 Diag(Loc, DiagID) 5653 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5654 } 5655 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5656 return ResultTy; 5657 } 5658 if (lType->isIntegerType() && rType->isAnyPointerType()) { 5659 unsigned DiagID = 0; 5660 if (LHSIsNull) { 5661 if (isRelational) 5662 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5663 } else if (isRelational) 5664 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5665 else 5666 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5667 5668 if (DiagID) { 5669 Diag(Loc, DiagID) 5670 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5671 } 5672 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5673 return ResultTy; 5674 } 5675 // Handle block pointers. 5676 if (!isRelational && RHSIsNull 5677 && lType->isBlockPointerType() && rType->isIntegerType()) { 5678 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5679 return ResultTy; 5680 } 5681 if (!isRelational && LHSIsNull 5682 && lType->isIntegerType() && rType->isBlockPointerType()) { 5683 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5684 return ResultTy; 5685 } 5686 return InvalidOperands(Loc, lex, rex); 5687} 5688 5689/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5690/// operates on extended vector types. Instead of producing an IntTy result, 5691/// like a scalar comparison, a vector comparison produces a vector of integer 5692/// types. 5693QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5694 SourceLocation Loc, 5695 bool isRelational) { 5696 // Check to make sure we're operating on vectors of the same type and width, 5697 // Allowing one side to be a scalar of element type. 5698 QualType vType = CheckVectorOperands(Loc, lex, rex); 5699 if (vType.isNull()) 5700 return vType; 5701 5702 QualType lType = lex->getType(); 5703 QualType rType = rex->getType(); 5704 5705 // For non-floating point types, check for self-comparisons of the form 5706 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5707 // often indicate logic errors in the program. 5708 if (!lType->isFloatingType()) { 5709 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5710 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5711 if (DRL->getDecl() == DRR->getDecl()) 5712 DiagRuntimeBehavior(Loc, PDiag(diag::warn_selfcomparison)); 5713 } 5714 5715 // Check for comparisons of floating point operands using != and ==. 5716 if (!isRelational && lType->isFloatingType()) { 5717 assert (rType->isFloatingType()); 5718 CheckFloatComparison(Loc,lex,rex); 5719 } 5720 5721 // Return the type for the comparison, which is the same as vector type for 5722 // integer vectors, or an integer type of identical size and number of 5723 // elements for floating point vectors. 5724 if (lType->isIntegerType()) 5725 return lType; 5726 5727 const VectorType *VTy = lType->getAs<VectorType>(); 5728 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5729 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5730 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5731 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5732 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5733 5734 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5735 "Unhandled vector element size in vector compare"); 5736 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5737} 5738 5739inline QualType Sema::CheckBitwiseOperands( 5740 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5741 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5742 return CheckVectorOperands(Loc, lex, rex); 5743 5744 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5745 5746 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5747 return compType; 5748 return InvalidOperands(Loc, lex, rex); 5749} 5750 5751inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5752 Expr *&lex, Expr *&rex, SourceLocation Loc) { 5753 if (!Context.getLangOptions().CPlusPlus) { 5754 UsualUnaryConversions(lex); 5755 UsualUnaryConversions(rex); 5756 5757 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5758 return InvalidOperands(Loc, lex, rex); 5759 5760 return Context.IntTy; 5761 } 5762 5763 // C++ [expr.log.and]p1 5764 // C++ [expr.log.or]p1 5765 // The operands are both implicitly converted to type bool (clause 4). 5766 StandardConversionSequence LHS; 5767 if (!IsStandardConversion(lex, Context.BoolTy, 5768 /*InOverloadResolution=*/false, LHS)) 5769 return InvalidOperands(Loc, lex, rex); 5770 5771 if (PerformImplicitConversion(lex, Context.BoolTy, LHS, 5772 AA_Passing, /*IgnoreBaseAccess=*/false)) 5773 return InvalidOperands(Loc, lex, rex); 5774 5775 StandardConversionSequence RHS; 5776 if (!IsStandardConversion(rex, Context.BoolTy, 5777 /*InOverloadResolution=*/false, RHS)) 5778 return InvalidOperands(Loc, lex, rex); 5779 5780 if (PerformImplicitConversion(rex, Context.BoolTy, RHS, 5781 AA_Passing, /*IgnoreBaseAccess=*/false)) 5782 return InvalidOperands(Loc, lex, rex); 5783 5784 // C++ [expr.log.and]p2 5785 // C++ [expr.log.or]p2 5786 // The result is a bool. 5787 return Context.BoolTy; 5788} 5789 5790/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5791/// is a read-only property; return true if so. A readonly property expression 5792/// depends on various declarations and thus must be treated specially. 5793/// 5794static bool IsReadonlyProperty(Expr *E, Sema &S) { 5795 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5796 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5797 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5798 QualType BaseType = PropExpr->getBase()->getType(); 5799 if (const ObjCObjectPointerType *OPT = 5800 BaseType->getAsObjCInterfacePointerType()) 5801 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5802 if (S.isPropertyReadonly(PDecl, IFace)) 5803 return true; 5804 } 5805 } 5806 return false; 5807} 5808 5809/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5810/// emit an error and return true. If so, return false. 5811static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5812 SourceLocation OrigLoc = Loc; 5813 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5814 &Loc); 5815 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5816 IsLV = Expr::MLV_ReadonlyProperty; 5817 if (IsLV == Expr::MLV_Valid) 5818 return false; 5819 5820 unsigned Diag = 0; 5821 bool NeedType = false; 5822 switch (IsLV) { // C99 6.5.16p2 5823 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5824 case Expr::MLV_ArrayType: 5825 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5826 NeedType = true; 5827 break; 5828 case Expr::MLV_NotObjectType: 5829 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5830 NeedType = true; 5831 break; 5832 case Expr::MLV_LValueCast: 5833 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5834 break; 5835 case Expr::MLV_Valid: 5836 llvm_unreachable("did not take early return for MLV_Valid"); 5837 case Expr::MLV_InvalidExpression: 5838 case Expr::MLV_MemberFunction: 5839 case Expr::MLV_ClassTemporary: 5840 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5841 break; 5842 case Expr::MLV_IncompleteType: 5843 case Expr::MLV_IncompleteVoidType: 5844 return S.RequireCompleteType(Loc, E->getType(), 5845 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5846 << E->getSourceRange()); 5847 case Expr::MLV_DuplicateVectorComponents: 5848 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5849 break; 5850 case Expr::MLV_NotBlockQualified: 5851 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5852 break; 5853 case Expr::MLV_ReadonlyProperty: 5854 Diag = diag::error_readonly_property_assignment; 5855 break; 5856 case Expr::MLV_NoSetterProperty: 5857 Diag = diag::error_nosetter_property_assignment; 5858 break; 5859 case Expr::MLV_SubObjCPropertySetting: 5860 Diag = diag::error_no_subobject_property_setting; 5861 break; 5862 } 5863 5864 SourceRange Assign; 5865 if (Loc != OrigLoc) 5866 Assign = SourceRange(OrigLoc, OrigLoc); 5867 if (NeedType) 5868 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5869 else 5870 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5871 return true; 5872} 5873 5874 5875 5876// C99 6.5.16.1 5877QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5878 SourceLocation Loc, 5879 QualType CompoundType) { 5880 // Verify that LHS is a modifiable lvalue, and emit error if not. 5881 if (CheckForModifiableLvalue(LHS, Loc, *this)) 5882 return QualType(); 5883 5884 QualType LHSType = LHS->getType(); 5885 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 5886 5887 AssignConvertType ConvTy; 5888 if (CompoundType.isNull()) { 5889 // Simple assignment "x = y". 5890 ConvTy = CheckSingleAssignmentConstraints(LHSType, RHS); 5891 // Special case of NSObject attributes on c-style pointer types. 5892 if (ConvTy == IncompatiblePointer && 5893 ((Context.isObjCNSObjectType(LHSType) && 5894 RHSType->isObjCObjectPointerType()) || 5895 (Context.isObjCNSObjectType(RHSType) && 5896 LHSType->isObjCObjectPointerType()))) 5897 ConvTy = Compatible; 5898 5899 // If the RHS is a unary plus or minus, check to see if they = and + are 5900 // right next to each other. If so, the user may have typo'd "x =+ 4" 5901 // instead of "x += 4". 5902 Expr *RHSCheck = RHS; 5903 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 5904 RHSCheck = ICE->getSubExpr(); 5905 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 5906 if ((UO->getOpcode() == UnaryOperator::Plus || 5907 UO->getOpcode() == UnaryOperator::Minus) && 5908 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 5909 // Only if the two operators are exactly adjacent. 5910 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 5911 // And there is a space or other character before the subexpr of the 5912 // unary +/-. We don't want to warn on "x=-1". 5913 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 5914 UO->getSubExpr()->getLocStart().isFileID()) { 5915 Diag(Loc, diag::warn_not_compound_assign) 5916 << (UO->getOpcode() == UnaryOperator::Plus ? "+" : "-") 5917 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 5918 } 5919 } 5920 } else { 5921 // Compound assignment "x += y" 5922 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 5923 } 5924 5925 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 5926 RHS, AA_Assigning)) 5927 return QualType(); 5928 5929 // C99 6.5.16p3: The type of an assignment expression is the type of the 5930 // left operand unless the left operand has qualified type, in which case 5931 // it is the unqualified version of the type of the left operand. 5932 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 5933 // is converted to the type of the assignment expression (above). 5934 // C++ 5.17p1: the type of the assignment expression is that of its left 5935 // operand. 5936 return LHSType.getUnqualifiedType(); 5937} 5938 5939// C99 6.5.17 5940QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 5941 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 5942 // C++ does not perform this conversion (C++ [expr.comma]p1). 5943 if (!getLangOptions().CPlusPlus) 5944 DefaultFunctionArrayLvalueConversion(RHS); 5945 5946 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 5947 // incomplete in C++). 5948 5949 return RHS->getType(); 5950} 5951 5952/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 5953/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 5954QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 5955 bool isInc) { 5956 if (Op->isTypeDependent()) 5957 return Context.DependentTy; 5958 5959 QualType ResType = Op->getType(); 5960 assert(!ResType.isNull() && "no type for increment/decrement expression"); 5961 5962 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 5963 // Decrement of bool is not allowed. 5964 if (!isInc) { 5965 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 5966 return QualType(); 5967 } 5968 // Increment of bool sets it to true, but is deprecated. 5969 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 5970 } else if (ResType->isRealType()) { 5971 // OK! 5972 } else if (ResType->isAnyPointerType()) { 5973 QualType PointeeTy = ResType->getPointeeType(); 5974 5975 // C99 6.5.2.4p2, 6.5.6p2 5976 if (PointeeTy->isVoidType()) { 5977 if (getLangOptions().CPlusPlus) { 5978 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 5979 << Op->getSourceRange(); 5980 return QualType(); 5981 } 5982 5983 // Pointer to void is a GNU extension in C. 5984 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 5985 } else if (PointeeTy->isFunctionType()) { 5986 if (getLangOptions().CPlusPlus) { 5987 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 5988 << Op->getType() << Op->getSourceRange(); 5989 return QualType(); 5990 } 5991 5992 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 5993 << ResType << Op->getSourceRange(); 5994 } else if (RequireCompleteType(OpLoc, PointeeTy, 5995 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5996 << Op->getSourceRange() 5997 << ResType)) 5998 return QualType(); 5999 // Diagnose bad cases where we step over interface counts. 6000 else if (PointeeTy->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 6001 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6002 << PointeeTy << Op->getSourceRange(); 6003 return QualType(); 6004 } 6005 } else if (ResType->isAnyComplexType()) { 6006 // C99 does not support ++/-- on complex types, we allow as an extension. 6007 Diag(OpLoc, diag::ext_integer_increment_complex) 6008 << ResType << Op->getSourceRange(); 6009 } else { 6010 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6011 << ResType << int(isInc) << Op->getSourceRange(); 6012 return QualType(); 6013 } 6014 // At this point, we know we have a real, complex or pointer type. 6015 // Now make sure the operand is a modifiable lvalue. 6016 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6017 return QualType(); 6018 return ResType; 6019} 6020 6021/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6022/// This routine allows us to typecheck complex/recursive expressions 6023/// where the declaration is needed for type checking. We only need to 6024/// handle cases when the expression references a function designator 6025/// or is an lvalue. Here are some examples: 6026/// - &(x) => x 6027/// - &*****f => f for f a function designator. 6028/// - &s.xx => s 6029/// - &s.zz[1].yy -> s, if zz is an array 6030/// - *(x + 1) -> x, if x is an array 6031/// - &"123"[2] -> 0 6032/// - & __real__ x -> x 6033static NamedDecl *getPrimaryDecl(Expr *E) { 6034 switch (E->getStmtClass()) { 6035 case Stmt::DeclRefExprClass: 6036 return cast<DeclRefExpr>(E)->getDecl(); 6037 case Stmt::MemberExprClass: 6038 // If this is an arrow operator, the address is an offset from 6039 // the base's value, so the object the base refers to is 6040 // irrelevant. 6041 if (cast<MemberExpr>(E)->isArrow()) 6042 return 0; 6043 // Otherwise, the expression refers to a part of the base 6044 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6045 case Stmt::ArraySubscriptExprClass: { 6046 // FIXME: This code shouldn't be necessary! We should catch the implicit 6047 // promotion of register arrays earlier. 6048 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6049 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6050 if (ICE->getSubExpr()->getType()->isArrayType()) 6051 return getPrimaryDecl(ICE->getSubExpr()); 6052 } 6053 return 0; 6054 } 6055 case Stmt::UnaryOperatorClass: { 6056 UnaryOperator *UO = cast<UnaryOperator>(E); 6057 6058 switch(UO->getOpcode()) { 6059 case UnaryOperator::Real: 6060 case UnaryOperator::Imag: 6061 case UnaryOperator::Extension: 6062 return getPrimaryDecl(UO->getSubExpr()); 6063 default: 6064 return 0; 6065 } 6066 } 6067 case Stmt::ParenExprClass: 6068 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6069 case Stmt::ImplicitCastExprClass: 6070 // If the result of an implicit cast is an l-value, we care about 6071 // the sub-expression; otherwise, the result here doesn't matter. 6072 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6073 default: 6074 return 0; 6075 } 6076} 6077 6078/// CheckAddressOfOperand - The operand of & must be either a function 6079/// designator or an lvalue designating an object. If it is an lvalue, the 6080/// object cannot be declared with storage class register or be a bit field. 6081/// Note: The usual conversions are *not* applied to the operand of the & 6082/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6083/// In C++, the operand might be an overloaded function name, in which case 6084/// we allow the '&' but retain the overloaded-function type. 6085QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) { 6086 // Make sure to ignore parentheses in subsequent checks 6087 op = op->IgnoreParens(); 6088 6089 if (op->isTypeDependent()) 6090 return Context.DependentTy; 6091 6092 if (getLangOptions().C99) { 6093 // Implement C99-only parts of addressof rules. 6094 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6095 if (uOp->getOpcode() == UnaryOperator::Deref) 6096 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6097 // (assuming the deref expression is valid). 6098 return uOp->getSubExpr()->getType(); 6099 } 6100 // Technically, there should be a check for array subscript 6101 // expressions here, but the result of one is always an lvalue anyway. 6102 } 6103 NamedDecl *dcl = getPrimaryDecl(op); 6104 Expr::isLvalueResult lval = op->isLvalue(Context); 6105 6106 MemberExpr *ME = dyn_cast<MemberExpr>(op); 6107 if (lval == Expr::LV_MemberFunction && ME && 6108 isa<CXXMethodDecl>(ME->getMemberDecl())) { 6109 ValueDecl *dcl = cast<MemberExpr>(op)->getMemberDecl(); 6110 // &f where f is a member of the current object, or &o.f, or &p->f 6111 // All these are not allowed, and we need to catch them before the dcl 6112 // branch of the if, below. 6113 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6114 << dcl; 6115 // FIXME: Improve this diagnostic and provide a fixit. 6116 6117 // Now recover by acting as if the function had been accessed qualified. 6118 return Context.getMemberPointerType(op->getType(), 6119 Context.getTypeDeclType(cast<RecordDecl>(dcl->getDeclContext())) 6120 .getTypePtr()); 6121 } else if (lval == Expr::LV_ClassTemporary) { 6122 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6123 : diag::ext_typecheck_addrof_class_temporary) 6124 << op->getType() << op->getSourceRange(); 6125 if (isSFINAEContext()) 6126 return QualType(); 6127 } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6128 // C99 6.5.3.2p1 6129 // The operand must be either an l-value or a function designator 6130 if (!op->getType()->isFunctionType()) { 6131 // FIXME: emit more specific diag... 6132 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6133 << op->getSourceRange(); 6134 return QualType(); 6135 } 6136 } else if (op->getBitField()) { // C99 6.5.3.2p1 6137 // The operand cannot be a bit-field 6138 Diag(OpLoc, diag::err_typecheck_address_of) 6139 << "bit-field" << op->getSourceRange(); 6140 return QualType(); 6141 } else if (op->refersToVectorElement()) { 6142 // The operand cannot be an element of a vector 6143 Diag(OpLoc, diag::err_typecheck_address_of) 6144 << "vector element" << op->getSourceRange(); 6145 return QualType(); 6146 } else if (isa<ObjCPropertyRefExpr>(op)) { 6147 // cannot take address of a property expression. 6148 Diag(OpLoc, diag::err_typecheck_address_of) 6149 << "property expression" << op->getSourceRange(); 6150 return QualType(); 6151 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6152 // FIXME: Can LHS ever be null here? 6153 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6154 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6155 } else if (isa<UnresolvedLookupExpr>(op)) { 6156 return Context.OverloadTy; 6157 } else if (dcl) { // C99 6.5.3.2p1 6158 // We have an lvalue with a decl. Make sure the decl is not declared 6159 // with the register storage-class specifier. 6160 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6161 if (vd->getStorageClass() == VarDecl::Register) { 6162 Diag(OpLoc, diag::err_typecheck_address_of) 6163 << "register variable" << op->getSourceRange(); 6164 return QualType(); 6165 } 6166 } else if (isa<FunctionTemplateDecl>(dcl)) { 6167 return Context.OverloadTy; 6168 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6169 // Okay: we can take the address of a field. 6170 // Could be a pointer to member, though, if there is an explicit 6171 // scope qualifier for the class. 6172 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6173 DeclContext *Ctx = dcl->getDeclContext(); 6174 if (Ctx && Ctx->isRecord()) { 6175 if (FD->getType()->isReferenceType()) { 6176 Diag(OpLoc, 6177 diag::err_cannot_form_pointer_to_member_of_reference_type) 6178 << FD->getDeclName() << FD->getType(); 6179 return QualType(); 6180 } 6181 6182 return Context.getMemberPointerType(op->getType(), 6183 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6184 } 6185 } 6186 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(dcl)) { 6187 // Okay: we can take the address of a function. 6188 // As above. 6189 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier() && 6190 MD->isInstance()) 6191 return Context.getMemberPointerType(op->getType(), 6192 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6193 } else if (!isa<FunctionDecl>(dcl)) 6194 assert(0 && "Unknown/unexpected decl type"); 6195 } 6196 6197 if (lval == Expr::LV_IncompleteVoidType) { 6198 // Taking the address of a void variable is technically illegal, but we 6199 // allow it in cases which are otherwise valid. 6200 // Example: "extern void x; void* y = &x;". 6201 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6202 } 6203 6204 // If the operand has type "type", the result has type "pointer to type". 6205 return Context.getPointerType(op->getType()); 6206} 6207 6208QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6209 if (Op->isTypeDependent()) 6210 return Context.DependentTy; 6211 6212 UsualUnaryConversions(Op); 6213 QualType Ty = Op->getType(); 6214 6215 // Note that per both C89 and C99, this is always legal, even if ptype is an 6216 // incomplete type or void. It would be possible to warn about dereferencing 6217 // a void pointer, but it's completely well-defined, and such a warning is 6218 // unlikely to catch any mistakes. 6219 if (const PointerType *PT = Ty->getAs<PointerType>()) 6220 return PT->getPointeeType(); 6221 6222 if (const ObjCObjectPointerType *OPT = Ty->getAs<ObjCObjectPointerType>()) 6223 return OPT->getPointeeType(); 6224 6225 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6226 << Ty << Op->getSourceRange(); 6227 return QualType(); 6228} 6229 6230static inline BinaryOperator::Opcode ConvertTokenKindToBinaryOpcode( 6231 tok::TokenKind Kind) { 6232 BinaryOperator::Opcode Opc; 6233 switch (Kind) { 6234 default: assert(0 && "Unknown binop!"); 6235 case tok::periodstar: Opc = BinaryOperator::PtrMemD; break; 6236 case tok::arrowstar: Opc = BinaryOperator::PtrMemI; break; 6237 case tok::star: Opc = BinaryOperator::Mul; break; 6238 case tok::slash: Opc = BinaryOperator::Div; break; 6239 case tok::percent: Opc = BinaryOperator::Rem; break; 6240 case tok::plus: Opc = BinaryOperator::Add; break; 6241 case tok::minus: Opc = BinaryOperator::Sub; break; 6242 case tok::lessless: Opc = BinaryOperator::Shl; break; 6243 case tok::greatergreater: Opc = BinaryOperator::Shr; break; 6244 case tok::lessequal: Opc = BinaryOperator::LE; break; 6245 case tok::less: Opc = BinaryOperator::LT; break; 6246 case tok::greaterequal: Opc = BinaryOperator::GE; break; 6247 case tok::greater: Opc = BinaryOperator::GT; break; 6248 case tok::exclaimequal: Opc = BinaryOperator::NE; break; 6249 case tok::equalequal: Opc = BinaryOperator::EQ; break; 6250 case tok::amp: Opc = BinaryOperator::And; break; 6251 case tok::caret: Opc = BinaryOperator::Xor; break; 6252 case tok::pipe: Opc = BinaryOperator::Or; break; 6253 case tok::ampamp: Opc = BinaryOperator::LAnd; break; 6254 case tok::pipepipe: Opc = BinaryOperator::LOr; break; 6255 case tok::equal: Opc = BinaryOperator::Assign; break; 6256 case tok::starequal: Opc = BinaryOperator::MulAssign; break; 6257 case tok::slashequal: Opc = BinaryOperator::DivAssign; break; 6258 case tok::percentequal: Opc = BinaryOperator::RemAssign; break; 6259 case tok::plusequal: Opc = BinaryOperator::AddAssign; break; 6260 case tok::minusequal: Opc = BinaryOperator::SubAssign; break; 6261 case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break; 6262 case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break; 6263 case tok::ampequal: Opc = BinaryOperator::AndAssign; break; 6264 case tok::caretequal: Opc = BinaryOperator::XorAssign; break; 6265 case tok::pipeequal: Opc = BinaryOperator::OrAssign; break; 6266 case tok::comma: Opc = BinaryOperator::Comma; break; 6267 } 6268 return Opc; 6269} 6270 6271static inline UnaryOperator::Opcode ConvertTokenKindToUnaryOpcode( 6272 tok::TokenKind Kind) { 6273 UnaryOperator::Opcode Opc; 6274 switch (Kind) { 6275 default: assert(0 && "Unknown unary op!"); 6276 case tok::plusplus: Opc = UnaryOperator::PreInc; break; 6277 case tok::minusminus: Opc = UnaryOperator::PreDec; break; 6278 case tok::amp: Opc = UnaryOperator::AddrOf; break; 6279 case tok::star: Opc = UnaryOperator::Deref; break; 6280 case tok::plus: Opc = UnaryOperator::Plus; break; 6281 case tok::minus: Opc = UnaryOperator::Minus; break; 6282 case tok::tilde: Opc = UnaryOperator::Not; break; 6283 case tok::exclaim: Opc = UnaryOperator::LNot; break; 6284 case tok::kw___real: Opc = UnaryOperator::Real; break; 6285 case tok::kw___imag: Opc = UnaryOperator::Imag; break; 6286 case tok::kw___extension__: Opc = UnaryOperator::Extension; break; 6287 } 6288 return Opc; 6289} 6290 6291/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6292/// operator @p Opc at location @c TokLoc. This routine only supports 6293/// built-in operations; ActOnBinOp handles overloaded operators. 6294Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6295 unsigned Op, 6296 Expr *lhs, Expr *rhs) { 6297 QualType ResultTy; // Result type of the binary operator. 6298 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)Op; 6299 // The following two variables are used for compound assignment operators 6300 QualType CompLHSTy; // Type of LHS after promotions for computation 6301 QualType CompResultTy; // Type of computation result 6302 6303 switch (Opc) { 6304 case BinaryOperator::Assign: 6305 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6306 break; 6307 case BinaryOperator::PtrMemD: 6308 case BinaryOperator::PtrMemI: 6309 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6310 Opc == BinaryOperator::PtrMemI); 6311 break; 6312 case BinaryOperator::Mul: 6313 case BinaryOperator::Div: 6314 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6315 Opc == BinaryOperator::Div); 6316 break; 6317 case BinaryOperator::Rem: 6318 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6319 break; 6320 case BinaryOperator::Add: 6321 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6322 break; 6323 case BinaryOperator::Sub: 6324 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6325 break; 6326 case BinaryOperator::Shl: 6327 case BinaryOperator::Shr: 6328 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6329 break; 6330 case BinaryOperator::LE: 6331 case BinaryOperator::LT: 6332 case BinaryOperator::GE: 6333 case BinaryOperator::GT: 6334 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6335 break; 6336 case BinaryOperator::EQ: 6337 case BinaryOperator::NE: 6338 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6339 break; 6340 case BinaryOperator::And: 6341 case BinaryOperator::Xor: 6342 case BinaryOperator::Or: 6343 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6344 break; 6345 case BinaryOperator::LAnd: 6346 case BinaryOperator::LOr: 6347 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc); 6348 break; 6349 case BinaryOperator::MulAssign: 6350 case BinaryOperator::DivAssign: 6351 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6352 Opc == BinaryOperator::DivAssign); 6353 CompLHSTy = CompResultTy; 6354 if (!CompResultTy.isNull()) 6355 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6356 break; 6357 case BinaryOperator::RemAssign: 6358 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6359 CompLHSTy = CompResultTy; 6360 if (!CompResultTy.isNull()) 6361 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6362 break; 6363 case BinaryOperator::AddAssign: 6364 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6365 if (!CompResultTy.isNull()) 6366 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6367 break; 6368 case BinaryOperator::SubAssign: 6369 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6370 if (!CompResultTy.isNull()) 6371 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6372 break; 6373 case BinaryOperator::ShlAssign: 6374 case BinaryOperator::ShrAssign: 6375 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6376 CompLHSTy = CompResultTy; 6377 if (!CompResultTy.isNull()) 6378 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6379 break; 6380 case BinaryOperator::AndAssign: 6381 case BinaryOperator::XorAssign: 6382 case BinaryOperator::OrAssign: 6383 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6384 CompLHSTy = CompResultTy; 6385 if (!CompResultTy.isNull()) 6386 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6387 break; 6388 case BinaryOperator::Comma: 6389 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6390 break; 6391 } 6392 if (ResultTy.isNull()) 6393 return ExprError(); 6394 if (CompResultTy.isNull()) 6395 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6396 else 6397 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6398 CompLHSTy, CompResultTy, 6399 OpLoc)); 6400} 6401 6402/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6403/// ParenRange in parentheses. 6404static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6405 const PartialDiagnostic &PD, 6406 SourceRange ParenRange, 6407 const PartialDiagnostic &SecondPD, 6408 SourceRange SecondParenRange) { 6409 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(ParenRange.getEnd()); 6410 if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6411 // We can't display the parentheses, so just dig the 6412 // warning/error and return. 6413 Self.Diag(Loc, PD); 6414 return; 6415 } 6416 6417 Self.Diag(Loc, PD) 6418 << CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(") 6419 << CodeModificationHint::CreateInsertion(EndLoc, ")"); 6420 6421 if (!SecondPD.getDiagID()) 6422 return; 6423 6424 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6425 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6426 // We can't display the parentheses, so just dig the 6427 // warning/error and return. 6428 Self.Diag(Loc, SecondPD); 6429 return; 6430 } 6431 6432 Self.Diag(Loc, SecondPD) 6433 << CodeModificationHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6434 << CodeModificationHint::CreateInsertion(EndLoc, ")"); 6435} 6436 6437/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6438/// operators are mixed in a way that suggests that the programmer forgot that 6439/// comparison operators have higher precedence. The most typical example of 6440/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6441static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6442 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6443 typedef BinaryOperator BinOp; 6444 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6445 rhsopc = static_cast<BinOp::Opcode>(-1); 6446 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6447 lhsopc = BO->getOpcode(); 6448 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6449 rhsopc = BO->getOpcode(); 6450 6451 // Subs are not binary operators. 6452 if (lhsopc == -1 && rhsopc == -1) 6453 return; 6454 6455 // Bitwise operations are sometimes used as eager logical ops. 6456 // Don't diagnose this. 6457 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6458 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6459 return; 6460 6461 if (BinOp::isComparisonOp(lhsopc)) 6462 SuggestParentheses(Self, OpLoc, 6463 Self.PDiag(diag::warn_precedence_bitwise_rel) 6464 << SourceRange(lhs->getLocStart(), OpLoc) 6465 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6466 lhs->getSourceRange(), 6467 Self.PDiag(diag::note_precedence_bitwise_first) 6468 << BinOp::getOpcodeStr(Opc), 6469 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd())); 6470 else if (BinOp::isComparisonOp(rhsopc)) 6471 SuggestParentheses(Self, OpLoc, 6472 Self.PDiag(diag::warn_precedence_bitwise_rel) 6473 << SourceRange(OpLoc, rhs->getLocEnd()) 6474 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6475 rhs->getSourceRange(), 6476 Self.PDiag(diag::note_precedence_bitwise_first) 6477 << BinOp::getOpcodeStr(Opc), 6478 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart())); 6479} 6480 6481/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6482/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6483/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6484static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6485 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6486 if (BinaryOperator::isBitwiseOp(Opc)) 6487 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6488} 6489 6490// Binary Operators. 'Tok' is the token for the operator. 6491Action::OwningExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6492 tok::TokenKind Kind, 6493 ExprArg LHS, ExprArg RHS) { 6494 BinaryOperator::Opcode Opc = ConvertTokenKindToBinaryOpcode(Kind); 6495 Expr *lhs = LHS.takeAs<Expr>(), *rhs = RHS.takeAs<Expr>(); 6496 6497 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6498 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6499 6500 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6501 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6502 6503 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6504} 6505 6506Action::OwningExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6507 BinaryOperator::Opcode Opc, 6508 Expr *lhs, Expr *rhs) { 6509 if (getLangOptions().CPlusPlus && 6510 (lhs->getType()->isOverloadableType() || 6511 rhs->getType()->isOverloadableType())) { 6512 // Find all of the overloaded operators visible from this 6513 // point. We perform both an operator-name lookup from the local 6514 // scope and an argument-dependent lookup based on the types of 6515 // the arguments. 6516 UnresolvedSet<16> Functions; 6517 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6518 if (S && OverOp != OO_None) 6519 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6520 Functions); 6521 6522 // Build the (potentially-overloaded, potentially-dependent) 6523 // binary operation. 6524 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6525 } 6526 6527 // Build a built-in binary operation. 6528 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6529} 6530 6531Action::OwningExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6532 unsigned OpcIn, 6533 ExprArg InputArg) { 6534 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6535 6536 // FIXME: Input is modified below, but InputArg is not updated appropriately. 6537 Expr *Input = (Expr *)InputArg.get(); 6538 QualType resultType; 6539 switch (Opc) { 6540 case UnaryOperator::OffsetOf: 6541 assert(false && "Invalid unary operator"); 6542 break; 6543 6544 case UnaryOperator::PreInc: 6545 case UnaryOperator::PreDec: 6546 case UnaryOperator::PostInc: 6547 case UnaryOperator::PostDec: 6548 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6549 Opc == UnaryOperator::PreInc || 6550 Opc == UnaryOperator::PostInc); 6551 break; 6552 case UnaryOperator::AddrOf: 6553 resultType = CheckAddressOfOperand(Input, OpLoc); 6554 break; 6555 case UnaryOperator::Deref: 6556 DefaultFunctionArrayLvalueConversion(Input); 6557 resultType = CheckIndirectionOperand(Input, OpLoc); 6558 break; 6559 case UnaryOperator::Plus: 6560 case UnaryOperator::Minus: 6561 UsualUnaryConversions(Input); 6562 resultType = Input->getType(); 6563 if (resultType->isDependentType()) 6564 break; 6565 if (resultType->isArithmeticType()) // C99 6.5.3.3p1 6566 break; 6567 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6568 resultType->isEnumeralType()) 6569 break; 6570 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6571 Opc == UnaryOperator::Plus && 6572 resultType->isPointerType()) 6573 break; 6574 6575 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6576 << resultType << Input->getSourceRange()); 6577 case UnaryOperator::Not: // bitwise complement 6578 UsualUnaryConversions(Input); 6579 resultType = Input->getType(); 6580 if (resultType->isDependentType()) 6581 break; 6582 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6583 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6584 // C99 does not support '~' for complex conjugation. 6585 Diag(OpLoc, diag::ext_integer_complement_complex) 6586 << resultType << Input->getSourceRange(); 6587 else if (!resultType->isIntegerType()) 6588 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6589 << resultType << Input->getSourceRange()); 6590 break; 6591 case UnaryOperator::LNot: // logical negation 6592 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6593 DefaultFunctionArrayLvalueConversion(Input); 6594 resultType = Input->getType(); 6595 if (resultType->isDependentType()) 6596 break; 6597 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6598 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6599 << resultType << Input->getSourceRange()); 6600 // LNot always has type int. C99 6.5.3.3p5. 6601 // In C++, it's bool. C++ 5.3.1p8 6602 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6603 break; 6604 case UnaryOperator::Real: 6605 case UnaryOperator::Imag: 6606 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UnaryOperator::Real); 6607 break; 6608 case UnaryOperator::Extension: 6609 resultType = Input->getType(); 6610 break; 6611 } 6612 if (resultType.isNull()) 6613 return ExprError(); 6614 6615 InputArg.release(); 6616 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6617} 6618 6619Action::OwningExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6620 UnaryOperator::Opcode Opc, 6621 ExprArg input) { 6622 Expr *Input = (Expr*)input.get(); 6623 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6624 Opc != UnaryOperator::Extension) { 6625 // Find all of the overloaded operators visible from this 6626 // point. We perform both an operator-name lookup from the local 6627 // scope and an argument-dependent lookup based on the types of 6628 // the arguments. 6629 UnresolvedSet<16> Functions; 6630 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6631 if (S && OverOp != OO_None) 6632 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6633 Functions); 6634 6635 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, move(input)); 6636 } 6637 6638 return CreateBuiltinUnaryOp(OpLoc, Opc, move(input)); 6639} 6640 6641// Unary Operators. 'Tok' is the token for the operator. 6642Action::OwningExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6643 tok::TokenKind Op, ExprArg input) { 6644 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), move(input)); 6645} 6646 6647/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6648Sema::OwningExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6649 SourceLocation LabLoc, 6650 IdentifierInfo *LabelII) { 6651 // Look up the record for this label identifier. 6652 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 6653 6654 // If we haven't seen this label yet, create a forward reference. It 6655 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6656 if (LabelDecl == 0) 6657 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6658 6659 // Create the AST node. The address of a label always has type 'void*'. 6660 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6661 Context.getPointerType(Context.VoidTy))); 6662} 6663 6664Sema::OwningExprResult 6665Sema::ActOnStmtExpr(SourceLocation LPLoc, StmtArg substmt, 6666 SourceLocation RPLoc) { // "({..})" 6667 Stmt *SubStmt = static_cast<Stmt*>(substmt.get()); 6668 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6669 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6670 6671 bool isFileScope 6672 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6673 if (isFileScope) 6674 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6675 6676 // FIXME: there are a variety of strange constraints to enforce here, for 6677 // example, it is not possible to goto into a stmt expression apparently. 6678 // More semantic analysis is needed. 6679 6680 // If there are sub stmts in the compound stmt, take the type of the last one 6681 // as the type of the stmtexpr. 6682 QualType Ty = Context.VoidTy; 6683 6684 if (!Compound->body_empty()) { 6685 Stmt *LastStmt = Compound->body_back(); 6686 // If LastStmt is a label, skip down through into the body. 6687 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6688 LastStmt = Label->getSubStmt(); 6689 6690 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6691 Ty = LastExpr->getType(); 6692 } 6693 6694 // FIXME: Check that expression type is complete/non-abstract; statement 6695 // expressions are not lvalues. 6696 6697 substmt.release(); 6698 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6699} 6700 6701Sema::OwningExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 6702 SourceLocation BuiltinLoc, 6703 SourceLocation TypeLoc, 6704 TypeTy *argty, 6705 OffsetOfComponent *CompPtr, 6706 unsigned NumComponents, 6707 SourceLocation RPLoc) { 6708 // FIXME: This function leaks all expressions in the offset components on 6709 // error. 6710 // FIXME: Preserve type source info. 6711 QualType ArgTy = GetTypeFromParser(argty); 6712 assert(!ArgTy.isNull() && "Missing type argument!"); 6713 6714 bool Dependent = ArgTy->isDependentType(); 6715 6716 // We must have at least one component that refers to the type, and the first 6717 // one is known to be a field designator. Verify that the ArgTy represents 6718 // a struct/union/class. 6719 if (!Dependent && !ArgTy->isRecordType()) 6720 return ExprError(Diag(TypeLoc, diag::err_offsetof_record_type) << ArgTy); 6721 6722 // FIXME: Type must be complete per C99 7.17p3 because a declaring a variable 6723 // with an incomplete type would be illegal. 6724 6725 // Otherwise, create a null pointer as the base, and iteratively process 6726 // the offsetof designators. 6727 QualType ArgTyPtr = Context.getPointerType(ArgTy); 6728 Expr* Res = new (Context) ImplicitValueInitExpr(ArgTyPtr); 6729 Res = new (Context) UnaryOperator(Res, UnaryOperator::Deref, 6730 ArgTy, SourceLocation()); 6731 6732 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6733 // GCC extension, diagnose them. 6734 // FIXME: This diagnostic isn't actually visible because the location is in 6735 // a system header! 6736 if (NumComponents != 1) 6737 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6738 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6739 6740 if (!Dependent) { 6741 bool DidWarnAboutNonPOD = false; 6742 6743 if (RequireCompleteType(TypeLoc, Res->getType(), 6744 diag::err_offsetof_incomplete_type)) 6745 return ExprError(); 6746 6747 // FIXME: Dependent case loses a lot of information here. And probably 6748 // leaks like a sieve. 6749 for (unsigned i = 0; i != NumComponents; ++i) { 6750 const OffsetOfComponent &OC = CompPtr[i]; 6751 if (OC.isBrackets) { 6752 // Offset of an array sub-field. TODO: Should we allow vector elements? 6753 const ArrayType *AT = Context.getAsArrayType(Res->getType()); 6754 if (!AT) { 6755 Res->Destroy(Context); 6756 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6757 << Res->getType()); 6758 } 6759 6760 // FIXME: C++: Verify that operator[] isn't overloaded. 6761 6762 // Promote the array so it looks more like a normal array subscript 6763 // expression. 6764 DefaultFunctionArrayLvalueConversion(Res); 6765 6766 // C99 6.5.2.1p1 6767 Expr *Idx = static_cast<Expr*>(OC.U.E); 6768 // FIXME: Leaks Res 6769 if (!Idx->isTypeDependent() && !Idx->getType()->isIntegerType()) 6770 return ExprError(Diag(Idx->getLocStart(), 6771 diag::err_typecheck_subscript_not_integer) 6772 << Idx->getSourceRange()); 6773 6774 Res = new (Context) ArraySubscriptExpr(Res, Idx, AT->getElementType(), 6775 OC.LocEnd); 6776 continue; 6777 } 6778 6779 const RecordType *RC = Res->getType()->getAs<RecordType>(); 6780 if (!RC) { 6781 Res->Destroy(Context); 6782 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6783 << Res->getType()); 6784 } 6785 6786 // Get the decl corresponding to this. 6787 RecordDecl *RD = RC->getDecl(); 6788 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6789 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6790 DiagRuntimeBehavior(BuiltinLoc, 6791 PDiag(diag::warn_offsetof_non_pod_type) 6792 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6793 << Res->getType())) 6794 DidWarnAboutNonPOD = true; 6795 } 6796 6797 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6798 LookupQualifiedName(R, RD); 6799 6800 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6801 // FIXME: Leaks Res 6802 if (!MemberDecl) 6803 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6804 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, OC.LocEnd)); 6805 6806 // FIXME: C++: Verify that MemberDecl isn't a static field. 6807 // FIXME: Verify that MemberDecl isn't a bitfield. 6808 if (cast<RecordDecl>(MemberDecl->getDeclContext())->isAnonymousStructOrUnion()) { 6809 Res = BuildAnonymousStructUnionMemberReference( 6810 OC.LocEnd, MemberDecl, Res, OC.LocEnd).takeAs<Expr>(); 6811 } else { 6812 PerformObjectMemberConversion(Res, /*Qualifier=*/0, 6813 *R.begin(), MemberDecl); 6814 // MemberDecl->getType() doesn't get the right qualifiers, but it 6815 // doesn't matter here. 6816 Res = new (Context) MemberExpr(Res, false, MemberDecl, OC.LocEnd, 6817 MemberDecl->getType().getNonReferenceType()); 6818 } 6819 } 6820 } 6821 6822 return Owned(new (Context) UnaryOperator(Res, UnaryOperator::OffsetOf, 6823 Context.getSizeType(), BuiltinLoc)); 6824} 6825 6826 6827Sema::OwningExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 6828 TypeTy *arg1,TypeTy *arg2, 6829 SourceLocation RPLoc) { 6830 // FIXME: Preserve type source info. 6831 QualType argT1 = GetTypeFromParser(arg1); 6832 QualType argT2 = GetTypeFromParser(arg2); 6833 6834 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 6835 6836 if (getLangOptions().CPlusPlus) { 6837 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 6838 << SourceRange(BuiltinLoc, RPLoc); 6839 return ExprError(); 6840 } 6841 6842 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 6843 argT1, argT2, RPLoc)); 6844} 6845 6846Sema::OwningExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 6847 ExprArg cond, 6848 ExprArg expr1, ExprArg expr2, 6849 SourceLocation RPLoc) { 6850 Expr *CondExpr = static_cast<Expr*>(cond.get()); 6851 Expr *LHSExpr = static_cast<Expr*>(expr1.get()); 6852 Expr *RHSExpr = static_cast<Expr*>(expr2.get()); 6853 6854 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 6855 6856 QualType resType; 6857 bool ValueDependent = false; 6858 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 6859 resType = Context.DependentTy; 6860 ValueDependent = true; 6861 } else { 6862 // The conditional expression is required to be a constant expression. 6863 llvm::APSInt condEval(32); 6864 SourceLocation ExpLoc; 6865 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 6866 return ExprError(Diag(ExpLoc, 6867 diag::err_typecheck_choose_expr_requires_constant) 6868 << CondExpr->getSourceRange()); 6869 6870 // If the condition is > zero, then the AST type is the same as the LSHExpr. 6871 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 6872 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 6873 : RHSExpr->isValueDependent(); 6874 } 6875 6876 cond.release(); expr1.release(); expr2.release(); 6877 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 6878 resType, RPLoc, 6879 resType->isDependentType(), 6880 ValueDependent)); 6881} 6882 6883//===----------------------------------------------------------------------===// 6884// Clang Extensions. 6885//===----------------------------------------------------------------------===// 6886 6887/// ActOnBlockStart - This callback is invoked when a block literal is started. 6888void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 6889 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 6890 PushBlockScope(BlockScope, Block); 6891 CurContext->addDecl(Block); 6892 PushDeclContext(BlockScope, Block); 6893} 6894 6895void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 6896 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 6897 BlockScopeInfo *CurBlock = getCurBlock(); 6898 6899 if (ParamInfo.getNumTypeObjects() == 0 6900 || ParamInfo.getTypeObject(0).Kind != DeclaratorChunk::Function) { 6901 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 6902 QualType T = GetTypeForDeclarator(ParamInfo, CurScope); 6903 6904 if (T->isArrayType()) { 6905 Diag(ParamInfo.getSourceRange().getBegin(), 6906 diag::err_block_returns_array); 6907 return; 6908 } 6909 6910 // The parameter list is optional, if there was none, assume (). 6911 if (!T->isFunctionType()) 6912 T = Context.getFunctionType(T, 0, 0, false, 0, false, false, 0, 0, 6913 FunctionType::ExtInfo()); 6914 6915 CurBlock->hasPrototype = true; 6916 CurBlock->isVariadic = false; 6917 // Check for a valid sentinel attribute on this block. 6918 if (CurBlock->TheDecl->getAttr<SentinelAttr>()) { 6919 Diag(ParamInfo.getAttributes()->getLoc(), 6920 diag::warn_attribute_sentinel_not_variadic) << 1; 6921 // FIXME: remove the attribute. 6922 } 6923 QualType RetTy = T.getTypePtr()->getAs<FunctionType>()->getResultType(); 6924 6925 // Do not allow returning a objc interface by-value. 6926 if (RetTy->isObjCInterfaceType()) { 6927 Diag(ParamInfo.getSourceRange().getBegin(), 6928 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 6929 return; 6930 } 6931 6932 CurBlock->ReturnType = RetTy; 6933 return; 6934 } 6935 6936 // Analyze arguments to block. 6937 assert(ParamInfo.getTypeObject(0).Kind == DeclaratorChunk::Function && 6938 "Not a function declarator!"); 6939 DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getTypeObject(0).Fun; 6940 6941 CurBlock->hasPrototype = FTI.hasPrototype; 6942 CurBlock->isVariadic = true; 6943 6944 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs function that takes 6945 // no arguments, not a function that takes a single void argument. 6946 if (FTI.hasPrototype && 6947 FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 6948 (!FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType().getCVRQualifiers()&& 6949 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType())) { 6950 // empty arg list, don't push any params. 6951 CurBlock->isVariadic = false; 6952 } else if (FTI.hasPrototype) { 6953 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 6954 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 6955 if (Param->getIdentifier() == 0 && 6956 !Param->isImplicit() && 6957 !Param->isInvalidDecl() && 6958 !getLangOptions().CPlusPlus) 6959 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 6960 CurBlock->Params.push_back(Param); 6961 } 6962 CurBlock->isVariadic = FTI.isVariadic; 6963 } 6964 CurBlock->TheDecl->setParams(CurBlock->Params.data(), 6965 CurBlock->Params.size()); 6966 CurBlock->TheDecl->setIsVariadic(CurBlock->isVariadic); 6967 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 6968 6969 bool ShouldCheckShadow = 6970 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 6971 6972 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 6973 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 6974 (*AI)->setOwningFunction(CurBlock->TheDecl); 6975 6976 // If this has an identifier, add it to the scope stack. 6977 if ((*AI)->getIdentifier()) { 6978 if (ShouldCheckShadow) 6979 CheckShadow(CurBlock->TheScope, *AI); 6980 6981 PushOnScopeChains(*AI, CurBlock->TheScope); 6982 } 6983 } 6984 6985 // Check for a valid sentinel attribute on this block. 6986 if (!CurBlock->isVariadic && 6987 CurBlock->TheDecl->getAttr<SentinelAttr>()) { 6988 Diag(ParamInfo.getAttributes()->getLoc(), 6989 diag::warn_attribute_sentinel_not_variadic) << 1; 6990 // FIXME: remove the attribute. 6991 } 6992 6993 // Analyze the return type. 6994 QualType T = GetTypeForDeclarator(ParamInfo, CurScope); 6995 QualType RetTy = T->getAs<FunctionType>()->getResultType(); 6996 6997 // Do not allow returning a objc interface by-value. 6998 if (RetTy->isObjCInterfaceType()) { 6999 Diag(ParamInfo.getSourceRange().getBegin(), 7000 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7001 } else if (!RetTy->isDependentType()) 7002 CurBlock->ReturnType = RetTy; 7003} 7004 7005/// ActOnBlockError - If there is an error parsing a block, this callback 7006/// is invoked to pop the information about the block from the action impl. 7007void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7008 // Pop off CurBlock, handle nested blocks. 7009 PopDeclContext(); 7010 PopFunctionOrBlockScope(); 7011 // FIXME: Delete the ParmVarDecl objects as well??? 7012} 7013 7014/// ActOnBlockStmtExpr - This is called when the body of a block statement 7015/// literal was successfully completed. ^(int x){...} 7016Sema::OwningExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7017 StmtArg body, Scope *CurScope) { 7018 // If blocks are disabled, emit an error. 7019 if (!LangOpts.Blocks) 7020 Diag(CaretLoc, diag::err_blocks_disable); 7021 7022 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7023 7024 PopDeclContext(); 7025 7026 QualType RetTy = Context.VoidTy; 7027 if (!BSI->ReturnType.isNull()) 7028 RetTy = BSI->ReturnType; 7029 7030 llvm::SmallVector<QualType, 8> ArgTypes; 7031 for (unsigned i = 0, e = BSI->Params.size(); i != e; ++i) 7032 ArgTypes.push_back(BSI->Params[i]->getType()); 7033 7034 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7035 QualType BlockTy; 7036 if (!BSI->hasPrototype) 7037 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, false, false, 0, 0, 7038 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7039 else 7040 BlockTy = Context.getFunctionType(RetTy, ArgTypes.data(), ArgTypes.size(), 7041 BSI->isVariadic, 0, false, false, 0, 0, 7042 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7043 7044 // FIXME: Check that return/parameter types are complete/non-abstract 7045 DiagnoseUnusedParameters(BSI->Params.begin(), BSI->Params.end()); 7046 BlockTy = Context.getBlockPointerType(BlockTy); 7047 7048 // If needed, diagnose invalid gotos and switches in the block. 7049 if (FunctionNeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7050 DiagnoseInvalidJumps(static_cast<CompoundStmt*>(body.get())); 7051 7052 BSI->TheDecl->setBody(body.takeAs<CompoundStmt>()); 7053 7054 bool Good = true; 7055 // Check goto/label use. 7056 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7057 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7058 LabelStmt *L = I->second; 7059 7060 // Verify that we have no forward references left. If so, there was a goto 7061 // or address of a label taken, but no definition of it. 7062 if (L->getSubStmt() != 0) 7063 continue; 7064 7065 // Emit error. 7066 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7067 Good = false; 7068 } 7069 if (!Good) { 7070 PopFunctionOrBlockScope(); 7071 return ExprError(); 7072 } 7073 7074 // Issue any analysis-based warnings. 7075 const sema::AnalysisBasedWarnings::Policy &WP = 7076 AnalysisWarnings.getDefaultPolicy(); 7077 AnalysisWarnings.IssueWarnings(WP, BSI->TheDecl, BlockTy); 7078 7079 Expr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7080 BSI->hasBlockDeclRefExprs); 7081 PopFunctionOrBlockScope(); 7082 return Owned(Result); 7083} 7084 7085Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7086 ExprArg expr, TypeTy *type, 7087 SourceLocation RPLoc) { 7088 QualType T = GetTypeFromParser(type); 7089 Expr *E = static_cast<Expr*>(expr.get()); 7090 Expr *OrigExpr = E; 7091 7092 InitBuiltinVaListType(); 7093 7094 // Get the va_list type 7095 QualType VaListType = Context.getBuiltinVaListType(); 7096 if (VaListType->isArrayType()) { 7097 // Deal with implicit array decay; for example, on x86-64, 7098 // va_list is an array, but it's supposed to decay to 7099 // a pointer for va_arg. 7100 VaListType = Context.getArrayDecayedType(VaListType); 7101 // Make sure the input expression also decays appropriately. 7102 UsualUnaryConversions(E); 7103 } else { 7104 // Otherwise, the va_list argument must be an l-value because 7105 // it is modified by va_arg. 7106 if (!E->isTypeDependent() && 7107 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7108 return ExprError(); 7109 } 7110 7111 if (!E->isTypeDependent() && 7112 !Context.hasSameType(VaListType, E->getType())) { 7113 return ExprError(Diag(E->getLocStart(), 7114 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7115 << OrigExpr->getType() << E->getSourceRange()); 7116 } 7117 7118 // FIXME: Check that type is complete/non-abstract 7119 // FIXME: Warn if a non-POD type is passed in. 7120 7121 expr.release(); 7122 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, T.getNonReferenceType(), 7123 RPLoc)); 7124} 7125 7126Sema::OwningExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7127 // The type of __null will be int or long, depending on the size of 7128 // pointers on the target. 7129 QualType Ty; 7130 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7131 Ty = Context.IntTy; 7132 else 7133 Ty = Context.LongTy; 7134 7135 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7136} 7137 7138static void 7139MakeObjCStringLiteralCodeModificationHint(Sema& SemaRef, 7140 QualType DstType, 7141 Expr *SrcExpr, 7142 CodeModificationHint &Hint) { 7143 if (!SemaRef.getLangOptions().ObjC1) 7144 return; 7145 7146 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7147 if (!PT) 7148 return; 7149 7150 // Check if the destination is of type 'id'. 7151 if (!PT->isObjCIdType()) { 7152 // Check if the destination is the 'NSString' interface. 7153 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7154 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7155 return; 7156 } 7157 7158 // Strip off any parens and casts. 7159 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7160 if (!SL || SL->isWide()) 7161 return; 7162 7163 Hint = CodeModificationHint::CreateInsertion(SL->getLocStart(), "@"); 7164} 7165 7166bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7167 SourceLocation Loc, 7168 QualType DstType, QualType SrcType, 7169 Expr *SrcExpr, AssignmentAction Action) { 7170 // Decode the result (notice that AST's are still created for extensions). 7171 bool isInvalid = false; 7172 unsigned DiagKind; 7173 CodeModificationHint Hint; 7174 7175 switch (ConvTy) { 7176 default: assert(0 && "Unknown conversion type"); 7177 case Compatible: return false; 7178 case PointerToInt: 7179 DiagKind = diag::ext_typecheck_convert_pointer_int; 7180 break; 7181 case IntToPointer: 7182 DiagKind = diag::ext_typecheck_convert_int_pointer; 7183 break; 7184 case IncompatiblePointer: 7185 MakeObjCStringLiteralCodeModificationHint(*this, DstType, SrcExpr, Hint); 7186 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7187 break; 7188 case IncompatiblePointerSign: 7189 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7190 break; 7191 case FunctionVoidPointer: 7192 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7193 break; 7194 case CompatiblePointerDiscardsQualifiers: 7195 // If the qualifiers lost were because we were applying the 7196 // (deprecated) C++ conversion from a string literal to a char* 7197 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7198 // Ideally, this check would be performed in 7199 // CheckPointerTypesForAssignment. However, that would require a 7200 // bit of refactoring (so that the second argument is an 7201 // expression, rather than a type), which should be done as part 7202 // of a larger effort to fix CheckPointerTypesForAssignment for 7203 // C++ semantics. 7204 if (getLangOptions().CPlusPlus && 7205 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7206 return false; 7207 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7208 break; 7209 case IncompatibleNestedPointerQualifiers: 7210 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7211 break; 7212 case IntToBlockPointer: 7213 DiagKind = diag::err_int_to_block_pointer; 7214 break; 7215 case IncompatibleBlockPointer: 7216 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7217 break; 7218 case IncompatibleObjCQualifiedId: 7219 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7220 // it can give a more specific diagnostic. 7221 DiagKind = diag::warn_incompatible_qualified_id; 7222 break; 7223 case IncompatibleVectors: 7224 DiagKind = diag::warn_incompatible_vectors; 7225 break; 7226 case Incompatible: 7227 DiagKind = diag::err_typecheck_convert_incompatible; 7228 isInvalid = true; 7229 break; 7230 } 7231 7232 Diag(Loc, DiagKind) << DstType << SrcType << Action 7233 << SrcExpr->getSourceRange() << Hint; 7234 return isInvalid; 7235} 7236 7237bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7238 llvm::APSInt ICEResult; 7239 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7240 if (Result) 7241 *Result = ICEResult; 7242 return false; 7243 } 7244 7245 Expr::EvalResult EvalResult; 7246 7247 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7248 EvalResult.HasSideEffects) { 7249 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7250 7251 if (EvalResult.Diag) { 7252 // We only show the note if it's not the usual "invalid subexpression" 7253 // or if it's actually in a subexpression. 7254 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7255 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7256 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7257 } 7258 7259 return true; 7260 } 7261 7262 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7263 E->getSourceRange(); 7264 7265 if (EvalResult.Diag && 7266 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7267 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7268 7269 if (Result) 7270 *Result = EvalResult.Val.getInt(); 7271 return false; 7272} 7273 7274void 7275Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7276 ExprEvalContexts.push_back( 7277 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7278} 7279 7280void 7281Sema::PopExpressionEvaluationContext() { 7282 // Pop the current expression evaluation context off the stack. 7283 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7284 ExprEvalContexts.pop_back(); 7285 7286 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7287 if (Rec.PotentiallyReferenced) { 7288 // Mark any remaining declarations in the current position of the stack 7289 // as "referenced". If they were not meant to be referenced, semantic 7290 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7291 for (PotentiallyReferencedDecls::iterator 7292 I = Rec.PotentiallyReferenced->begin(), 7293 IEnd = Rec.PotentiallyReferenced->end(); 7294 I != IEnd; ++I) 7295 MarkDeclarationReferenced(I->first, I->second); 7296 } 7297 7298 if (Rec.PotentiallyDiagnosed) { 7299 // Emit any pending diagnostics. 7300 for (PotentiallyEmittedDiagnostics::iterator 7301 I = Rec.PotentiallyDiagnosed->begin(), 7302 IEnd = Rec.PotentiallyDiagnosed->end(); 7303 I != IEnd; ++I) 7304 Diag(I->first, I->second); 7305 } 7306 } 7307 7308 // When are coming out of an unevaluated context, clear out any 7309 // temporaries that we may have created as part of the evaluation of 7310 // the expression in that context: they aren't relevant because they 7311 // will never be constructed. 7312 if (Rec.Context == Unevaluated && 7313 ExprTemporaries.size() > Rec.NumTemporaries) 7314 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7315 ExprTemporaries.end()); 7316 7317 // Destroy the popped expression evaluation record. 7318 Rec.Destroy(); 7319} 7320 7321/// \brief Note that the given declaration was referenced in the source code. 7322/// 7323/// This routine should be invoke whenever a given declaration is referenced 7324/// in the source code, and where that reference occurred. If this declaration 7325/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7326/// C99 6.9p3), then the declaration will be marked as used. 7327/// 7328/// \param Loc the location where the declaration was referenced. 7329/// 7330/// \param D the declaration that has been referenced by the source code. 7331void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7332 assert(D && "No declaration?"); 7333 7334 if (D->isUsed()) 7335 return; 7336 7337 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7338 // template or not. The reason for this is that unevaluated expressions 7339 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7340 // -Wunused-parameters) 7341 if (isa<ParmVarDecl>(D) || 7342 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) 7343 D->setUsed(true); 7344 7345 // Do not mark anything as "used" within a dependent context; wait for 7346 // an instantiation. 7347 if (CurContext->isDependentContext()) 7348 return; 7349 7350 switch (ExprEvalContexts.back().Context) { 7351 case Unevaluated: 7352 // We are in an expression that is not potentially evaluated; do nothing. 7353 return; 7354 7355 case PotentiallyEvaluated: 7356 // We are in a potentially-evaluated expression, so this declaration is 7357 // "used"; handle this below. 7358 break; 7359 7360 case PotentiallyPotentiallyEvaluated: 7361 // We are in an expression that may be potentially evaluated; queue this 7362 // declaration reference until we know whether the expression is 7363 // potentially evaluated. 7364 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7365 return; 7366 } 7367 7368 // Note that this declaration has been used. 7369 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7370 unsigned TypeQuals; 7371 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7372 if (!Constructor->isUsed()) 7373 DefineImplicitDefaultConstructor(Loc, Constructor); 7374 } else if (Constructor->isImplicit() && 7375 Constructor->isCopyConstructor(TypeQuals)) { 7376 if (!Constructor->isUsed()) 7377 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7378 } 7379 7380 MaybeMarkVirtualMembersReferenced(Loc, Constructor); 7381 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7382 if (Destructor->isImplicit() && !Destructor->isUsed()) 7383 DefineImplicitDestructor(Loc, Destructor); 7384 7385 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7386 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7387 MethodDecl->getOverloadedOperator() == OO_Equal) { 7388 if (!MethodDecl->isUsed()) 7389 DefineImplicitOverloadedAssign(Loc, MethodDecl); 7390 } 7391 } 7392 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7393 // Implicit instantiation of function templates and member functions of 7394 // class templates. 7395 if (!Function->getBody() && Function->isImplicitlyInstantiable()) { 7396 bool AlreadyInstantiated = false; 7397 if (FunctionTemplateSpecializationInfo *SpecInfo 7398 = Function->getTemplateSpecializationInfo()) { 7399 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7400 SpecInfo->setPointOfInstantiation(Loc); 7401 else if (SpecInfo->getTemplateSpecializationKind() 7402 == TSK_ImplicitInstantiation) 7403 AlreadyInstantiated = true; 7404 } else if (MemberSpecializationInfo *MSInfo 7405 = Function->getMemberSpecializationInfo()) { 7406 if (MSInfo->getPointOfInstantiation().isInvalid()) 7407 MSInfo->setPointOfInstantiation(Loc); 7408 else if (MSInfo->getTemplateSpecializationKind() 7409 == TSK_ImplicitInstantiation) 7410 AlreadyInstantiated = true; 7411 } 7412 7413 if (!AlreadyInstantiated) { 7414 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7415 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7416 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7417 Loc)); 7418 else 7419 PendingImplicitInstantiations.push_back(std::make_pair(Function, 7420 Loc)); 7421 } 7422 } 7423 7424 // FIXME: keep track of references to static functions 7425 Function->setUsed(true); 7426 7427 return; 7428 } 7429 7430 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7431 // Implicit instantiation of static data members of class templates. 7432 if (Var->isStaticDataMember() && 7433 Var->getInstantiatedFromStaticDataMember()) { 7434 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7435 assert(MSInfo && "Missing member specialization information?"); 7436 if (MSInfo->getPointOfInstantiation().isInvalid() && 7437 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7438 MSInfo->setPointOfInstantiation(Loc); 7439 PendingImplicitInstantiations.push_back(std::make_pair(Var, Loc)); 7440 } 7441 } 7442 7443 // FIXME: keep track of references to static data? 7444 7445 D->setUsed(true); 7446 return; 7447 } 7448} 7449 7450/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7451/// of the program being compiled. 7452/// 7453/// This routine emits the given diagnostic when the code currently being 7454/// type-checked is "potentially evaluated", meaning that there is a 7455/// possibility that the code will actually be executable. Code in sizeof() 7456/// expressions, code used only during overload resolution, etc., are not 7457/// potentially evaluated. This routine will suppress such diagnostics or, 7458/// in the absolutely nutty case of potentially potentially evaluated 7459/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7460/// later. 7461/// 7462/// This routine should be used for all diagnostics that describe the run-time 7463/// behavior of a program, such as passing a non-POD value through an ellipsis. 7464/// Failure to do so will likely result in spurious diagnostics or failures 7465/// during overload resolution or within sizeof/alignof/typeof/typeid. 7466bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7467 const PartialDiagnostic &PD) { 7468 switch (ExprEvalContexts.back().Context ) { 7469 case Unevaluated: 7470 // The argument will never be evaluated, so don't complain. 7471 break; 7472 7473 case PotentiallyEvaluated: 7474 Diag(Loc, PD); 7475 return true; 7476 7477 case PotentiallyPotentiallyEvaluated: 7478 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7479 break; 7480 } 7481 7482 return false; 7483} 7484 7485bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7486 CallExpr *CE, FunctionDecl *FD) { 7487 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7488 return false; 7489 7490 PartialDiagnostic Note = 7491 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7492 << FD->getDeclName() : PDiag(); 7493 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7494 7495 if (RequireCompleteType(Loc, ReturnType, 7496 FD ? 7497 PDiag(diag::err_call_function_incomplete_return) 7498 << CE->getSourceRange() << FD->getDeclName() : 7499 PDiag(diag::err_call_incomplete_return) 7500 << CE->getSourceRange(), 7501 std::make_pair(NoteLoc, Note))) 7502 return true; 7503 7504 return false; 7505} 7506 7507// Diagnose the common s/=/==/ typo. Note that adding parentheses 7508// will prevent this condition from triggering, which is what we want. 7509void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7510 SourceLocation Loc; 7511 7512 unsigned diagnostic = diag::warn_condition_is_assignment; 7513 7514 if (isa<BinaryOperator>(E)) { 7515 BinaryOperator *Op = cast<BinaryOperator>(E); 7516 if (Op->getOpcode() != BinaryOperator::Assign) 7517 return; 7518 7519 // Greylist some idioms by putting them into a warning subcategory. 7520 if (ObjCMessageExpr *ME 7521 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7522 Selector Sel = ME->getSelector(); 7523 7524 // self = [<foo> init...] 7525 if (isSelfExpr(Op->getLHS()) 7526 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7527 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7528 7529 // <foo> = [<bar> nextObject] 7530 else if (Sel.isUnarySelector() && 7531 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7532 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7533 } 7534 7535 Loc = Op->getOperatorLoc(); 7536 } else if (isa<CXXOperatorCallExpr>(E)) { 7537 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7538 if (Op->getOperator() != OO_Equal) 7539 return; 7540 7541 Loc = Op->getOperatorLoc(); 7542 } else { 7543 // Not an assignment. 7544 return; 7545 } 7546 7547 SourceLocation Open = E->getSourceRange().getBegin(); 7548 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7549 7550 Diag(Loc, diagnostic) 7551 << E->getSourceRange() 7552 << CodeModificationHint::CreateInsertion(Open, "(") 7553 << CodeModificationHint::CreateInsertion(Close, ")"); 7554 Diag(Loc, diag::note_condition_assign_to_comparison) 7555 << CodeModificationHint::CreateReplacement(Loc, "=="); 7556} 7557 7558bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7559 DiagnoseAssignmentAsCondition(E); 7560 7561 if (!E->isTypeDependent()) { 7562 DefaultFunctionArrayLvalueConversion(E); 7563 7564 QualType T = E->getType(); 7565 7566 if (getLangOptions().CPlusPlus) { 7567 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7568 return true; 7569 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7570 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7571 << T << E->getSourceRange(); 7572 return true; 7573 } 7574 } 7575 7576 return false; 7577} 7578