SemaExpr.cpp revision e86dd3e5c6ee1ad0d406d6d3a7fb0782a5eedbf1
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 772enum IMAKind { 773 /// The reference is definitely not an instance member access. 774 IMA_Static, 775 776 /// The reference may be an implicit instance member access. 777 IMA_Mixed, 778 779 /// The reference may be to an instance member, but it is invalid if 780 /// so, because the context is not an instance method. 781 IMA_Mixed_StaticContext, 782 783 /// The reference may be to an instance member, but it is invalid if 784 /// so, because the context is from an unrelated class. 785 IMA_Mixed_Unrelated, 786 787 /// The reference is definitely an implicit instance member access. 788 IMA_Instance, 789 790 /// The reference may be to an unresolved using declaration. 791 IMA_Unresolved, 792 793 /// The reference may be to an unresolved using declaration and the 794 /// context is not an instance method. 795 IMA_Unresolved_StaticContext, 796 797 /// The reference is to a member of an anonymous structure in a 798 /// non-class context. 799 IMA_AnonymousMember, 800 801 /// All possible referrents are instance members and the current 802 /// context is not an instance method. 803 IMA_Error_StaticContext, 804 805 /// All possible referrents are instance members of an unrelated 806 /// class. 807 IMA_Error_Unrelated 808}; 809 810/// The given lookup names class member(s) and is not being used for 811/// an address-of-member expression. Classify the type of access 812/// according to whether it's possible that this reference names an 813/// instance member. This is best-effort; it is okay to 814/// conservatively answer "yes", in which case some errors will simply 815/// not be caught until template-instantiation. 816static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 817 const LookupResult &R) { 818 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 819 820 bool isStaticContext = 821 (!isa<CXXMethodDecl>(SemaRef.CurContext) || 822 cast<CXXMethodDecl>(SemaRef.CurContext)->isStatic()); 823 824 if (R.isUnresolvableResult()) 825 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 826 827 // Collect all the declaring classes of instance members we find. 828 bool hasNonInstance = false; 829 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 830 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 831 NamedDecl *D = *I; 832 if (D->isCXXInstanceMember()) { 833 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 834 835 // If this is a member of an anonymous record, move out to the 836 // innermost non-anonymous struct or union. If there isn't one, 837 // that's a special case. 838 while (R->isAnonymousStructOrUnion()) { 839 R = dyn_cast<CXXRecordDecl>(R->getParent()); 840 if (!R) return IMA_AnonymousMember; 841 } 842 Classes.insert(R->getCanonicalDecl()); 843 } 844 else 845 hasNonInstance = true; 846 } 847 848 // If we didn't find any instance members, it can't be an implicit 849 // member reference. 850 if (Classes.empty()) 851 return IMA_Static; 852 853 // If the current context is not an instance method, it can't be 854 // an implicit member reference. 855 if (isStaticContext) 856 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 857 858 // If we can prove that the current context is unrelated to all the 859 // declaring classes, it can't be an implicit member reference (in 860 // which case it's an error if any of those members are selected). 861 if (IsProvablyNotDerivedFrom(SemaRef, 862 cast<CXXMethodDecl>(SemaRef.CurContext)->getParent(), 863 Classes)) 864 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 865 866 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 867} 868 869/// Diagnose a reference to a field with no object available. 870static void DiagnoseInstanceReference(Sema &SemaRef, 871 const CXXScopeSpec &SS, 872 const LookupResult &R) { 873 SourceLocation Loc = R.getNameLoc(); 874 SourceRange Range(Loc); 875 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 876 877 if (R.getAsSingle<FieldDecl>()) { 878 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 879 if (MD->isStatic()) { 880 // "invalid use of member 'x' in static member function" 881 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 882 << Range << R.getLookupName(); 883 return; 884 } 885 } 886 887 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 888 << R.getLookupName() << Range; 889 return; 890 } 891 892 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 893} 894 895/// Diagnose an empty lookup. 896/// 897/// \return false if new lookup candidates were found 898bool Sema::DiagnoseEmptyLookup(Scope *S, const CXXScopeSpec &SS, 899 LookupResult &R) { 900 DeclarationName Name = R.getLookupName(); 901 902 unsigned diagnostic = diag::err_undeclared_var_use; 903 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 904 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 905 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 906 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 907 diagnostic = diag::err_undeclared_use; 908 diagnostic_suggest = diag::err_undeclared_use_suggest; 909 } 910 911 // If the original lookup was an unqualified lookup, fake an 912 // unqualified lookup. This is useful when (for example) the 913 // original lookup would not have found something because it was a 914 // dependent name. 915 for (DeclContext *DC = SS.isEmpty()? CurContext : 0; 916 DC; DC = DC->getParent()) { 917 if (isa<CXXRecordDecl>(DC)) { 918 LookupQualifiedName(R, DC); 919 920 if (!R.empty()) { 921 // Don't give errors about ambiguities in this lookup. 922 R.suppressDiagnostics(); 923 924 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 925 bool isInstance = CurMethod && 926 CurMethod->isInstance() && 927 DC == CurMethod->getParent(); 928 929 // Give a code modification hint to insert 'this->'. 930 // TODO: fixit for inserting 'Base<T>::' in the other cases. 931 // Actually quite difficult! 932 if (isInstance) 933 Diag(R.getNameLoc(), diagnostic) << Name 934 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 935 else 936 Diag(R.getNameLoc(), diagnostic) << Name; 937 938 // Do we really want to note all of these? 939 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 940 Diag((*I)->getLocation(), diag::note_dependent_var_use); 941 942 // Tell the callee to try to recover. 943 return false; 944 } 945 } 946 } 947 948 // We didn't find anything, so try to correct for a typo. 949 if (S && CorrectTypo(R, S, &SS)) { 950 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 951 if (SS.isEmpty()) 952 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 953 << FixItHint::CreateReplacement(R.getNameLoc(), 954 R.getLookupName().getAsString()); 955 else 956 Diag(R.getNameLoc(), diag::err_no_member_suggest) 957 << Name << computeDeclContext(SS, false) << R.getLookupName() 958 << SS.getRange() 959 << FixItHint::CreateReplacement(R.getNameLoc(), 960 R.getLookupName().getAsString()); 961 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 962 Diag(ND->getLocation(), diag::note_previous_decl) 963 << ND->getDeclName(); 964 965 // Tell the callee to try to recover. 966 return false; 967 } 968 969 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 970 // FIXME: If we ended up with a typo for a type name or 971 // Objective-C class name, we're in trouble because the parser 972 // is in the wrong place to recover. Suggest the typo 973 // correction, but don't make it a fix-it since we're not going 974 // to recover well anyway. 975 if (SS.isEmpty()) 976 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 977 else 978 Diag(R.getNameLoc(), diag::err_no_member_suggest) 979 << Name << computeDeclContext(SS, false) << R.getLookupName() 980 << SS.getRange(); 981 982 // Don't try to recover; it won't work. 983 return true; 984 } 985 986 R.clear(); 987 } 988 989 // Emit a special diagnostic for failed member lookups. 990 // FIXME: computing the declaration context might fail here (?) 991 if (!SS.isEmpty()) { 992 Diag(R.getNameLoc(), diag::err_no_member) 993 << Name << computeDeclContext(SS, false) 994 << SS.getRange(); 995 return true; 996 } 997 998 // Give up, we can't recover. 999 Diag(R.getNameLoc(), diagnostic) << Name; 1000 return true; 1001} 1002 1003Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S, 1004 const CXXScopeSpec &SS, 1005 UnqualifiedId &Id, 1006 bool HasTrailingLParen, 1007 bool isAddressOfOperand) { 1008 assert(!(isAddressOfOperand && HasTrailingLParen) && 1009 "cannot be direct & operand and have a trailing lparen"); 1010 1011 if (SS.isInvalid()) 1012 return ExprError(); 1013 1014 TemplateArgumentListInfo TemplateArgsBuffer; 1015 1016 // Decompose the UnqualifiedId into the following data. 1017 DeclarationName Name; 1018 SourceLocation NameLoc; 1019 const TemplateArgumentListInfo *TemplateArgs; 1020 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 1021 Name, NameLoc, TemplateArgs); 1022 1023 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1024 1025 // C++ [temp.dep.expr]p3: 1026 // An id-expression is type-dependent if it contains: 1027 // -- an identifier that was declared with a dependent type, 1028 // (note: handled after lookup) 1029 // -- a template-id that is dependent, 1030 // (note: handled in BuildTemplateIdExpr) 1031 // -- a conversion-function-id that specifies a dependent type, 1032 // -- a nested-name-specifier that contains a class-name that 1033 // names a dependent type. 1034 // Determine whether this is a member of an unknown specialization; 1035 // we need to handle these differently. 1036 if ((Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1037 Name.getCXXNameType()->isDependentType()) || 1038 (SS.isSet() && IsDependentIdExpression(*this, SS))) { 1039 return ActOnDependentIdExpression(SS, Name, NameLoc, 1040 isAddressOfOperand, 1041 TemplateArgs); 1042 } 1043 1044 // Perform the required lookup. 1045 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1046 if (TemplateArgs) { 1047 // Just re-use the lookup done by isTemplateName. 1048 DecomposeTemplateName(R, Id); 1049 } else { 1050 bool IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1051 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1052 1053 // If this reference is in an Objective-C method, then we need to do 1054 // some special Objective-C lookup, too. 1055 if (IvarLookupFollowUp) { 1056 OwningExprResult E(LookupInObjCMethod(R, S, II, true)); 1057 if (E.isInvalid()) 1058 return ExprError(); 1059 1060 Expr *Ex = E.takeAs<Expr>(); 1061 if (Ex) return Owned(Ex); 1062 } 1063 } 1064 1065 if (R.isAmbiguous()) 1066 return ExprError(); 1067 1068 // Determine whether this name might be a candidate for 1069 // argument-dependent lookup. 1070 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1071 1072 if (R.empty() && !ADL) { 1073 // Otherwise, this could be an implicitly declared function reference (legal 1074 // in C90, extension in C99, forbidden in C++). 1075 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1076 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1077 if (D) R.addDecl(D); 1078 } 1079 1080 // If this name wasn't predeclared and if this is not a function 1081 // call, diagnose the problem. 1082 if (R.empty()) { 1083 if (DiagnoseEmptyLookup(S, SS, R)) 1084 return ExprError(); 1085 1086 assert(!R.empty() && 1087 "DiagnoseEmptyLookup returned false but added no results"); 1088 1089 // If we found an Objective-C instance variable, let 1090 // LookupInObjCMethod build the appropriate expression to 1091 // reference the ivar. 1092 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1093 R.clear(); 1094 OwningExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1095 assert(E.isInvalid() || E.get()); 1096 return move(E); 1097 } 1098 } 1099 } 1100 1101 // This is guaranteed from this point on. 1102 assert(!R.empty() || ADL); 1103 1104 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1105 // Warn about constructs like: 1106 // if (void *X = foo()) { ... } else { X }. 1107 // In the else block, the pointer is always false. 1108 1109 if (Var->isDeclaredInCondition() && Var->getType()->isScalarType()) { 1110 Scope *CheckS = S; 1111 while (CheckS && CheckS->getControlParent()) { 1112 if (CheckS->isWithinElse() && 1113 CheckS->getControlParent()->isDeclScope(DeclPtrTy::make(Var))) { 1114 ExprError(Diag(NameLoc, diag::warn_value_always_zero) 1115 << Var->getDeclName() 1116 << (Var->getType()->isPointerType()? 2 : 1117 Var->getType()->isBooleanType()? 1 : 0)); 1118 break; 1119 } 1120 1121 // Move to the parent of this scope. 1122 CheckS = CheckS->getParent(); 1123 } 1124 } 1125 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1126 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1127 // C99 DR 316 says that, if a function type comes from a 1128 // function definition (without a prototype), that type is only 1129 // used for checking compatibility. Therefore, when referencing 1130 // the function, we pretend that we don't have the full function 1131 // type. 1132 if (DiagnoseUseOfDecl(Func, NameLoc)) 1133 return ExprError(); 1134 1135 QualType T = Func->getType(); 1136 QualType NoProtoType = T; 1137 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1138 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType()); 1139 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1140 } 1141 } 1142 1143 // Check whether this might be a C++ implicit instance member access. 1144 // C++ [expr.prim.general]p6: 1145 // Within the definition of a non-static member function, an 1146 // identifier that names a non-static member is transformed to a 1147 // class member access expression. 1148 // But note that &SomeClass::foo is grammatically distinct, even 1149 // though we don't parse it that way. 1150 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1151 bool isAbstractMemberPointer = (isAddressOfOperand && !SS.isEmpty()); 1152 if (!isAbstractMemberPointer) 1153 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1154 } 1155 1156 if (TemplateArgs) 1157 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1158 1159 return BuildDeclarationNameExpr(SS, R, ADL); 1160} 1161 1162/// Builds an expression which might be an implicit member expression. 1163Sema::OwningExprResult 1164Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1165 LookupResult &R, 1166 const TemplateArgumentListInfo *TemplateArgs) { 1167 switch (ClassifyImplicitMemberAccess(*this, R)) { 1168 case IMA_Instance: 1169 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1170 1171 case IMA_AnonymousMember: 1172 assert(R.isSingleResult()); 1173 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1174 R.getAsSingle<FieldDecl>()); 1175 1176 case IMA_Mixed: 1177 case IMA_Mixed_Unrelated: 1178 case IMA_Unresolved: 1179 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1180 1181 case IMA_Static: 1182 case IMA_Mixed_StaticContext: 1183 case IMA_Unresolved_StaticContext: 1184 if (TemplateArgs) 1185 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1186 return BuildDeclarationNameExpr(SS, R, false); 1187 1188 case IMA_Error_StaticContext: 1189 case IMA_Error_Unrelated: 1190 DiagnoseInstanceReference(*this, SS, R); 1191 return ExprError(); 1192 } 1193 1194 llvm_unreachable("unexpected instance member access kind"); 1195 return ExprError(); 1196} 1197 1198/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1199/// declaration name, generally during template instantiation. 1200/// There's a large number of things which don't need to be done along 1201/// this path. 1202Sema::OwningExprResult 1203Sema::BuildQualifiedDeclarationNameExpr(const CXXScopeSpec &SS, 1204 DeclarationName Name, 1205 SourceLocation NameLoc) { 1206 DeclContext *DC; 1207 if (!(DC = computeDeclContext(SS, false)) || 1208 DC->isDependentContext() || 1209 RequireCompleteDeclContext(SS)) 1210 return BuildDependentDeclRefExpr(SS, Name, NameLoc, 0); 1211 1212 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1213 LookupQualifiedName(R, DC); 1214 1215 if (R.isAmbiguous()) 1216 return ExprError(); 1217 1218 if (R.empty()) { 1219 Diag(NameLoc, diag::err_no_member) << Name << DC << SS.getRange(); 1220 return ExprError(); 1221 } 1222 1223 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1224} 1225 1226/// LookupInObjCMethod - The parser has read a name in, and Sema has 1227/// detected that we're currently inside an ObjC method. Perform some 1228/// additional lookup. 1229/// 1230/// Ideally, most of this would be done by lookup, but there's 1231/// actually quite a lot of extra work involved. 1232/// 1233/// Returns a null sentinel to indicate trivial success. 1234Sema::OwningExprResult 1235Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1236 IdentifierInfo *II, 1237 bool AllowBuiltinCreation) { 1238 SourceLocation Loc = Lookup.getNameLoc(); 1239 1240 // There are two cases to handle here. 1) scoped lookup could have failed, 1241 // in which case we should look for an ivar. 2) scoped lookup could have 1242 // found a decl, but that decl is outside the current instance method (i.e. 1243 // a global variable). In these two cases, we do a lookup for an ivar with 1244 // this name, if the lookup sucedes, we replace it our current decl. 1245 1246 // If we're in a class method, we don't normally want to look for 1247 // ivars. But if we don't find anything else, and there's an 1248 // ivar, that's an error. 1249 bool IsClassMethod = getCurMethodDecl()->isClassMethod(); 1250 1251 bool LookForIvars; 1252 if (Lookup.empty()) 1253 LookForIvars = true; 1254 else if (IsClassMethod) 1255 LookForIvars = false; 1256 else 1257 LookForIvars = (Lookup.isSingleResult() && 1258 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1259 ObjCInterfaceDecl *IFace = 0; 1260 if (LookForIvars) { 1261 IFace = getCurMethodDecl()->getClassInterface(); 1262 ObjCInterfaceDecl *ClassDeclared; 1263 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1264 // Diagnose using an ivar in a class method. 1265 if (IsClassMethod) 1266 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1267 << IV->getDeclName()); 1268 1269 // If we're referencing an invalid decl, just return this as a silent 1270 // error node. The error diagnostic was already emitted on the decl. 1271 if (IV->isInvalidDecl()) 1272 return ExprError(); 1273 1274 // Check if referencing a field with __attribute__((deprecated)). 1275 if (DiagnoseUseOfDecl(IV, Loc)) 1276 return ExprError(); 1277 1278 // Diagnose the use of an ivar outside of the declaring class. 1279 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1280 ClassDeclared != IFace) 1281 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1282 1283 // FIXME: This should use a new expr for a direct reference, don't 1284 // turn this into Self->ivar, just return a BareIVarExpr or something. 1285 IdentifierInfo &II = Context.Idents.get("self"); 1286 UnqualifiedId SelfName; 1287 SelfName.setIdentifier(&II, SourceLocation()); 1288 CXXScopeSpec SelfScopeSpec; 1289 OwningExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1290 SelfName, false, false); 1291 MarkDeclarationReferenced(Loc, IV); 1292 return Owned(new (Context) 1293 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1294 SelfExpr.takeAs<Expr>(), true, true)); 1295 } 1296 } else if (getCurMethodDecl()->isInstanceMethod()) { 1297 // We should warn if a local variable hides an ivar. 1298 ObjCInterfaceDecl *IFace = getCurMethodDecl()->getClassInterface(); 1299 ObjCInterfaceDecl *ClassDeclared; 1300 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1301 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1302 IFace == ClassDeclared) 1303 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1304 } 1305 } 1306 1307 // Needed to implement property "super.method" notation. 1308 if (Lookup.empty() && II->isStr("super")) { 1309 QualType T; 1310 1311 if (getCurMethodDecl()->isInstanceMethod()) 1312 T = Context.getObjCObjectPointerType(Context.getObjCInterfaceType( 1313 getCurMethodDecl()->getClassInterface())); 1314 else 1315 T = Context.getObjCClassType(); 1316 return Owned(new (Context) ObjCSuperExpr(Loc, T)); 1317 } 1318 if (Lookup.empty() && II && AllowBuiltinCreation) { 1319 // FIXME. Consolidate this with similar code in LookupName. 1320 if (unsigned BuiltinID = II->getBuiltinID()) { 1321 if (!(getLangOptions().CPlusPlus && 1322 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1323 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1324 S, Lookup.isForRedeclaration(), 1325 Lookup.getNameLoc()); 1326 if (D) Lookup.addDecl(D); 1327 } 1328 } 1329 } 1330 // Sentinel value saying that we didn't do anything special. 1331 return Owned((Expr*) 0); 1332} 1333 1334/// \brief Cast a base object to a member's actual type. 1335/// 1336/// Logically this happens in three phases: 1337/// 1338/// * First we cast from the base type to the naming class. 1339/// The naming class is the class into which we were looking 1340/// when we found the member; it's the qualifier type if a 1341/// qualifier was provided, and otherwise it's the base type. 1342/// 1343/// * Next we cast from the naming class to the declaring class. 1344/// If the member we found was brought into a class's scope by 1345/// a using declaration, this is that class; otherwise it's 1346/// the class declaring the member. 1347/// 1348/// * Finally we cast from the declaring class to the "true" 1349/// declaring class of the member. This conversion does not 1350/// obey access control. 1351bool 1352Sema::PerformObjectMemberConversion(Expr *&From, 1353 NestedNameSpecifier *Qualifier, 1354 NamedDecl *FoundDecl, 1355 NamedDecl *Member) { 1356 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1357 if (!RD) 1358 return false; 1359 1360 QualType DestRecordType; 1361 QualType DestType; 1362 QualType FromRecordType; 1363 QualType FromType = From->getType(); 1364 bool PointerConversions = false; 1365 if (isa<FieldDecl>(Member)) { 1366 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1367 1368 if (FromType->getAs<PointerType>()) { 1369 DestType = Context.getPointerType(DestRecordType); 1370 FromRecordType = FromType->getPointeeType(); 1371 PointerConversions = true; 1372 } else { 1373 DestType = DestRecordType; 1374 FromRecordType = FromType; 1375 } 1376 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1377 if (Method->isStatic()) 1378 return false; 1379 1380 DestType = Method->getThisType(Context); 1381 DestRecordType = DestType->getPointeeType(); 1382 1383 if (FromType->getAs<PointerType>()) { 1384 FromRecordType = FromType->getPointeeType(); 1385 PointerConversions = true; 1386 } else { 1387 FromRecordType = FromType; 1388 DestType = DestRecordType; 1389 } 1390 } else { 1391 // No conversion necessary. 1392 return false; 1393 } 1394 1395 if (DestType->isDependentType() || FromType->isDependentType()) 1396 return false; 1397 1398 // If the unqualified types are the same, no conversion is necessary. 1399 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1400 return false; 1401 1402 SourceRange FromRange = From->getSourceRange(); 1403 SourceLocation FromLoc = FromRange.getBegin(); 1404 1405 // C++ [class.member.lookup]p8: 1406 // [...] Ambiguities can often be resolved by qualifying a name with its 1407 // class name. 1408 // 1409 // If the member was a qualified name and the qualified referred to a 1410 // specific base subobject type, we'll cast to that intermediate type 1411 // first and then to the object in which the member is declared. That allows 1412 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1413 // 1414 // class Base { public: int x; }; 1415 // class Derived1 : public Base { }; 1416 // class Derived2 : public Base { }; 1417 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1418 // 1419 // void VeryDerived::f() { 1420 // x = 17; // error: ambiguous base subobjects 1421 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1422 // } 1423 if (Qualifier) { 1424 QualType QType = QualType(Qualifier->getAsType(), 0); 1425 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1426 assert(QType->isRecordType() && "lookup done with non-record type"); 1427 1428 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1429 1430 // In C++98, the qualifier type doesn't actually have to be a base 1431 // type of the object type, in which case we just ignore it. 1432 // Otherwise build the appropriate casts. 1433 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1434 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1435 FromLoc, FromRange)) 1436 return true; 1437 1438 if (PointerConversions) 1439 QType = Context.getPointerType(QType); 1440 ImpCastExprToType(From, QType, CastExpr::CK_UncheckedDerivedToBase, 1441 /*isLvalue*/ !PointerConversions); 1442 1443 FromType = QType; 1444 FromRecordType = QRecordType; 1445 1446 // If the qualifier type was the same as the destination type, 1447 // we're done. 1448 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1449 return false; 1450 } 1451 } 1452 1453 bool IgnoreAccess = false; 1454 1455 // If we actually found the member through a using declaration, cast 1456 // down to the using declaration's type. 1457 // 1458 // Pointer equality is fine here because only one declaration of a 1459 // class ever has member declarations. 1460 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1461 assert(isa<UsingShadowDecl>(FoundDecl)); 1462 QualType URecordType = Context.getTypeDeclType( 1463 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1464 1465 // We only need to do this if the naming-class to declaring-class 1466 // conversion is non-trivial. 1467 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1468 assert(IsDerivedFrom(FromRecordType, URecordType)); 1469 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1470 FromLoc, FromRange)) 1471 return true; 1472 1473 QualType UType = URecordType; 1474 if (PointerConversions) 1475 UType = Context.getPointerType(UType); 1476 ImpCastExprToType(From, UType, CastExpr::CK_UncheckedDerivedToBase, 1477 /*isLvalue*/ !PointerConversions); 1478 FromType = UType; 1479 FromRecordType = URecordType; 1480 } 1481 1482 // We don't do access control for the conversion from the 1483 // declaring class to the true declaring class. 1484 IgnoreAccess = true; 1485 } 1486 1487 if (CheckDerivedToBaseConversion(FromRecordType, 1488 DestRecordType, 1489 FromLoc, 1490 FromRange, 1491 IgnoreAccess)) 1492 return true; 1493 1494 ImpCastExprToType(From, DestType, CastExpr::CK_UncheckedDerivedToBase, 1495 /*isLvalue=*/ !PointerConversions); 1496 return false; 1497} 1498 1499/// \brief Build a MemberExpr AST node. 1500static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1501 const CXXScopeSpec &SS, ValueDecl *Member, 1502 DeclAccessPair FoundDecl, 1503 SourceLocation Loc, QualType Ty, 1504 const TemplateArgumentListInfo *TemplateArgs = 0) { 1505 NestedNameSpecifier *Qualifier = 0; 1506 SourceRange QualifierRange; 1507 if (SS.isSet()) { 1508 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1509 QualifierRange = SS.getRange(); 1510 } 1511 1512 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1513 Member, FoundDecl, Loc, TemplateArgs, Ty); 1514} 1515 1516/// Builds an implicit member access expression. The current context 1517/// is known to be an instance method, and the given unqualified lookup 1518/// set is known to contain only instance members, at least one of which 1519/// is from an appropriate type. 1520Sema::OwningExprResult 1521Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1522 LookupResult &R, 1523 const TemplateArgumentListInfo *TemplateArgs, 1524 bool IsKnownInstance) { 1525 assert(!R.empty() && !R.isAmbiguous()); 1526 1527 SourceLocation Loc = R.getNameLoc(); 1528 1529 // We may have found a field within an anonymous union or struct 1530 // (C++ [class.union]). 1531 // FIXME: This needs to happen post-isImplicitMemberReference? 1532 // FIXME: template-ids inside anonymous structs? 1533 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1534 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1535 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1536 1537 // If this is known to be an instance access, go ahead and build a 1538 // 'this' expression now. 1539 QualType ThisType = cast<CXXMethodDecl>(CurContext)->getThisType(Context); 1540 Expr *This = 0; // null signifies implicit access 1541 if (IsKnownInstance) { 1542 SourceLocation Loc = R.getNameLoc(); 1543 if (SS.getRange().isValid()) 1544 Loc = SS.getRange().getBegin(); 1545 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1546 } 1547 1548 return BuildMemberReferenceExpr(ExprArg(*this, This), ThisType, 1549 /*OpLoc*/ SourceLocation(), 1550 /*IsArrow*/ true, 1551 SS, 1552 /*FirstQualifierInScope*/ 0, 1553 R, TemplateArgs); 1554} 1555 1556bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1557 const LookupResult &R, 1558 bool HasTrailingLParen) { 1559 // Only when used directly as the postfix-expression of a call. 1560 if (!HasTrailingLParen) 1561 return false; 1562 1563 // Never if a scope specifier was provided. 1564 if (SS.isSet()) 1565 return false; 1566 1567 // Only in C++ or ObjC++. 1568 if (!getLangOptions().CPlusPlus) 1569 return false; 1570 1571 // Turn off ADL when we find certain kinds of declarations during 1572 // normal lookup: 1573 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1574 NamedDecl *D = *I; 1575 1576 // C++0x [basic.lookup.argdep]p3: 1577 // -- a declaration of a class member 1578 // Since using decls preserve this property, we check this on the 1579 // original decl. 1580 if (D->isCXXClassMember()) 1581 return false; 1582 1583 // C++0x [basic.lookup.argdep]p3: 1584 // -- a block-scope function declaration that is not a 1585 // using-declaration 1586 // NOTE: we also trigger this for function templates (in fact, we 1587 // don't check the decl type at all, since all other decl types 1588 // turn off ADL anyway). 1589 if (isa<UsingShadowDecl>(D)) 1590 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1591 else if (D->getDeclContext()->isFunctionOrMethod()) 1592 return false; 1593 1594 // C++0x [basic.lookup.argdep]p3: 1595 // -- a declaration that is neither a function or a function 1596 // template 1597 // And also for builtin functions. 1598 if (isa<FunctionDecl>(D)) { 1599 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1600 1601 // But also builtin functions. 1602 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1603 return false; 1604 } else if (!isa<FunctionTemplateDecl>(D)) 1605 return false; 1606 } 1607 1608 return true; 1609} 1610 1611 1612/// Diagnoses obvious problems with the use of the given declaration 1613/// as an expression. This is only actually called for lookups that 1614/// were not overloaded, and it doesn't promise that the declaration 1615/// will in fact be used. 1616static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1617 if (isa<TypedefDecl>(D)) { 1618 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1619 return true; 1620 } 1621 1622 if (isa<ObjCInterfaceDecl>(D)) { 1623 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1624 return true; 1625 } 1626 1627 if (isa<NamespaceDecl>(D)) { 1628 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1629 return true; 1630 } 1631 1632 return false; 1633} 1634 1635Sema::OwningExprResult 1636Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1637 LookupResult &R, 1638 bool NeedsADL) { 1639 // If this is a single, fully-resolved result and we don't need ADL, 1640 // just build an ordinary singleton decl ref. 1641 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1642 return BuildDeclarationNameExpr(SS, R.getNameLoc(), R.getFoundDecl()); 1643 1644 // We only need to check the declaration if there's exactly one 1645 // result, because in the overloaded case the results can only be 1646 // functions and function templates. 1647 if (R.isSingleResult() && 1648 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1649 return ExprError(); 1650 1651 // Otherwise, just build an unresolved lookup expression. Suppress 1652 // any lookup-related diagnostics; we'll hash these out later, when 1653 // we've picked a target. 1654 R.suppressDiagnostics(); 1655 1656 bool Dependent 1657 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1658 UnresolvedLookupExpr *ULE 1659 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1660 (NestedNameSpecifier*) SS.getScopeRep(), 1661 SS.getRange(), 1662 R.getLookupName(), R.getNameLoc(), 1663 NeedsADL, R.isOverloadedResult()); 1664 ULE->addDecls(R.begin(), R.end()); 1665 1666 return Owned(ULE); 1667} 1668 1669 1670/// \brief Complete semantic analysis for a reference to the given declaration. 1671Sema::OwningExprResult 1672Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1673 SourceLocation Loc, NamedDecl *D) { 1674 assert(D && "Cannot refer to a NULL declaration"); 1675 assert(!isa<FunctionTemplateDecl>(D) && 1676 "Cannot refer unambiguously to a function template"); 1677 1678 if (CheckDeclInExpr(*this, Loc, D)) 1679 return ExprError(); 1680 1681 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1682 // Specifically diagnose references to class templates that are missing 1683 // a template argument list. 1684 Diag(Loc, diag::err_template_decl_ref) 1685 << Template << SS.getRange(); 1686 Diag(Template->getLocation(), diag::note_template_decl_here); 1687 return ExprError(); 1688 } 1689 1690 // Make sure that we're referring to a value. 1691 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1692 if (!VD) { 1693 Diag(Loc, diag::err_ref_non_value) 1694 << D << SS.getRange(); 1695 Diag(D->getLocation(), diag::note_declared_at); 1696 return ExprError(); 1697 } 1698 1699 // Check whether this declaration can be used. Note that we suppress 1700 // this check when we're going to perform argument-dependent lookup 1701 // on this function name, because this might not be the function 1702 // that overload resolution actually selects. 1703 if (DiagnoseUseOfDecl(VD, Loc)) 1704 return ExprError(); 1705 1706 // Only create DeclRefExpr's for valid Decl's. 1707 if (VD->isInvalidDecl()) 1708 return ExprError(); 1709 1710 // If the identifier reference is inside a block, and it refers to a value 1711 // that is outside the block, create a BlockDeclRefExpr instead of a 1712 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1713 // the block is formed. 1714 // 1715 // We do not do this for things like enum constants, global variables, etc, 1716 // as they do not get snapshotted. 1717 // 1718 if (getCurBlock() && 1719 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1720 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1721 Diag(Loc, diag::err_ref_vm_type); 1722 Diag(D->getLocation(), diag::note_declared_at); 1723 return ExprError(); 1724 } 1725 1726 if (VD->getType()->isArrayType()) { 1727 Diag(Loc, diag::err_ref_array_type); 1728 Diag(D->getLocation(), diag::note_declared_at); 1729 return ExprError(); 1730 } 1731 1732 MarkDeclarationReferenced(Loc, VD); 1733 QualType ExprTy = VD->getType().getNonReferenceType(); 1734 // The BlocksAttr indicates the variable is bound by-reference. 1735 if (VD->getAttr<BlocksAttr>()) 1736 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1737 // This is to record that a 'const' was actually synthesize and added. 1738 bool constAdded = !ExprTy.isConstQualified(); 1739 // Variable will be bound by-copy, make it const within the closure. 1740 1741 ExprTy.addConst(); 1742 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, false, 1743 constAdded)); 1744 } 1745 // If this reference is not in a block or if the referenced variable is 1746 // within the block, create a normal DeclRefExpr. 1747 1748 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), Loc, &SS); 1749} 1750 1751Sema::OwningExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1752 tok::TokenKind Kind) { 1753 PredefinedExpr::IdentType IT; 1754 1755 switch (Kind) { 1756 default: assert(0 && "Unknown simple primary expr!"); 1757 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1758 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1759 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1760 } 1761 1762 // Pre-defined identifiers are of type char[x], where x is the length of the 1763 // string. 1764 1765 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1766 if (!currentDecl) { 1767 Diag(Loc, diag::ext_predef_outside_function); 1768 currentDecl = Context.getTranslationUnitDecl(); 1769 } 1770 1771 QualType ResTy; 1772 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1773 ResTy = Context.DependentTy; 1774 } else { 1775 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1776 1777 llvm::APInt LengthI(32, Length + 1); 1778 ResTy = Context.CharTy.withConst(); 1779 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1780 } 1781 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1782} 1783 1784Sema::OwningExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1785 llvm::SmallString<16> CharBuffer; 1786 bool Invalid = false; 1787 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1788 if (Invalid) 1789 return ExprError(); 1790 1791 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1792 PP); 1793 if (Literal.hadError()) 1794 return ExprError(); 1795 1796 QualType Ty; 1797 if (!getLangOptions().CPlusPlus) 1798 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1799 else if (Literal.isWide()) 1800 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1801 else if (Literal.isMultiChar()) 1802 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1803 else 1804 Ty = Context.CharTy; // 'x' -> char in C++ 1805 1806 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1807 Literal.isWide(), 1808 Ty, Tok.getLocation())); 1809} 1810 1811Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1812 // Fast path for a single digit (which is quite common). A single digit 1813 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1814 if (Tok.getLength() == 1) { 1815 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1816 unsigned IntSize = Context.Target.getIntWidth(); 1817 return Owned(new (Context) IntegerLiteral(llvm::APInt(IntSize, Val-'0'), 1818 Context.IntTy, Tok.getLocation())); 1819 } 1820 1821 llvm::SmallString<512> IntegerBuffer; 1822 // Add padding so that NumericLiteralParser can overread by one character. 1823 IntegerBuffer.resize(Tok.getLength()+1); 1824 const char *ThisTokBegin = &IntegerBuffer[0]; 1825 1826 // Get the spelling of the token, which eliminates trigraphs, etc. 1827 bool Invalid = false; 1828 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1829 if (Invalid) 1830 return ExprError(); 1831 1832 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1833 Tok.getLocation(), PP); 1834 if (Literal.hadError) 1835 return ExprError(); 1836 1837 Expr *Res; 1838 1839 if (Literal.isFloatingLiteral()) { 1840 QualType Ty; 1841 if (Literal.isFloat) 1842 Ty = Context.FloatTy; 1843 else if (!Literal.isLong) 1844 Ty = Context.DoubleTy; 1845 else 1846 Ty = Context.LongDoubleTy; 1847 1848 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1849 1850 using llvm::APFloat; 1851 APFloat Val(Format); 1852 1853 APFloat::opStatus result = Literal.GetFloatValue(Val); 1854 1855 // Overflow is always an error, but underflow is only an error if 1856 // we underflowed to zero (APFloat reports denormals as underflow). 1857 if ((result & APFloat::opOverflow) || 1858 ((result & APFloat::opUnderflow) && Val.isZero())) { 1859 unsigned diagnostic; 1860 llvm::SmallString<20> buffer; 1861 if (result & APFloat::opOverflow) { 1862 diagnostic = diag::warn_float_overflow; 1863 APFloat::getLargest(Format).toString(buffer); 1864 } else { 1865 diagnostic = diag::warn_float_underflow; 1866 APFloat::getSmallest(Format).toString(buffer); 1867 } 1868 1869 Diag(Tok.getLocation(), diagnostic) 1870 << Ty 1871 << llvm::StringRef(buffer.data(), buffer.size()); 1872 } 1873 1874 bool isExact = (result == APFloat::opOK); 1875 Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation()); 1876 1877 } else if (!Literal.isIntegerLiteral()) { 1878 return ExprError(); 1879 } else { 1880 QualType Ty; 1881 1882 // long long is a C99 feature. 1883 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 1884 Literal.isLongLong) 1885 Diag(Tok.getLocation(), diag::ext_longlong); 1886 1887 // Get the value in the widest-possible width. 1888 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 1889 1890 if (Literal.GetIntegerValue(ResultVal)) { 1891 // If this value didn't fit into uintmax_t, warn and force to ull. 1892 Diag(Tok.getLocation(), diag::warn_integer_too_large); 1893 Ty = Context.UnsignedLongLongTy; 1894 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 1895 "long long is not intmax_t?"); 1896 } else { 1897 // If this value fits into a ULL, try to figure out what else it fits into 1898 // according to the rules of C99 6.4.4.1p5. 1899 1900 // Octal, Hexadecimal, and integers with a U suffix are allowed to 1901 // be an unsigned int. 1902 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 1903 1904 // Check from smallest to largest, picking the smallest type we can. 1905 unsigned Width = 0; 1906 if (!Literal.isLong && !Literal.isLongLong) { 1907 // Are int/unsigned possibilities? 1908 unsigned IntSize = Context.Target.getIntWidth(); 1909 1910 // Does it fit in a unsigned int? 1911 if (ResultVal.isIntN(IntSize)) { 1912 // Does it fit in a signed int? 1913 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 1914 Ty = Context.IntTy; 1915 else if (AllowUnsigned) 1916 Ty = Context.UnsignedIntTy; 1917 Width = IntSize; 1918 } 1919 } 1920 1921 // Are long/unsigned long possibilities? 1922 if (Ty.isNull() && !Literal.isLongLong) { 1923 unsigned LongSize = Context.Target.getLongWidth(); 1924 1925 // Does it fit in a unsigned long? 1926 if (ResultVal.isIntN(LongSize)) { 1927 // Does it fit in a signed long? 1928 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 1929 Ty = Context.LongTy; 1930 else if (AllowUnsigned) 1931 Ty = Context.UnsignedLongTy; 1932 Width = LongSize; 1933 } 1934 } 1935 1936 // Finally, check long long if needed. 1937 if (Ty.isNull()) { 1938 unsigned LongLongSize = Context.Target.getLongLongWidth(); 1939 1940 // Does it fit in a unsigned long long? 1941 if (ResultVal.isIntN(LongLongSize)) { 1942 // Does it fit in a signed long long? 1943 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 1944 Ty = Context.LongLongTy; 1945 else if (AllowUnsigned) 1946 Ty = Context.UnsignedLongLongTy; 1947 Width = LongLongSize; 1948 } 1949 } 1950 1951 // If we still couldn't decide a type, we probably have something that 1952 // does not fit in a signed long long, but has no U suffix. 1953 if (Ty.isNull()) { 1954 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 1955 Ty = Context.UnsignedLongLongTy; 1956 Width = Context.Target.getLongLongWidth(); 1957 } 1958 1959 if (ResultVal.getBitWidth() != Width) 1960 ResultVal.trunc(Width); 1961 } 1962 Res = new (Context) IntegerLiteral(ResultVal, Ty, Tok.getLocation()); 1963 } 1964 1965 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 1966 if (Literal.isImaginary) 1967 Res = new (Context) ImaginaryLiteral(Res, 1968 Context.getComplexType(Res->getType())); 1969 1970 return Owned(Res); 1971} 1972 1973Action::OwningExprResult Sema::ActOnParenExpr(SourceLocation L, 1974 SourceLocation R, ExprArg Val) { 1975 Expr *E = Val.takeAs<Expr>(); 1976 assert((E != 0) && "ActOnParenExpr() missing expr"); 1977 return Owned(new (Context) ParenExpr(L, R, E)); 1978} 1979 1980/// The UsualUnaryConversions() function is *not* called by this routine. 1981/// See C99 6.3.2.1p[2-4] for more details. 1982bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 1983 SourceLocation OpLoc, 1984 const SourceRange &ExprRange, 1985 bool isSizeof) { 1986 if (exprType->isDependentType()) 1987 return false; 1988 1989 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 1990 // the result is the size of the referenced type." 1991 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 1992 // result shall be the alignment of the referenced type." 1993 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 1994 exprType = Ref->getPointeeType(); 1995 1996 // C99 6.5.3.4p1: 1997 if (exprType->isFunctionType()) { 1998 // alignof(function) is allowed as an extension. 1999 if (isSizeof) 2000 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2001 return false; 2002 } 2003 2004 // Allow sizeof(void)/alignof(void) as an extension. 2005 if (exprType->isVoidType()) { 2006 Diag(OpLoc, diag::ext_sizeof_void_type) 2007 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2008 return false; 2009 } 2010 2011 if (RequireCompleteType(OpLoc, exprType, 2012 PDiag(diag::err_sizeof_alignof_incomplete_type) 2013 << int(!isSizeof) << ExprRange)) 2014 return true; 2015 2016 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2017 if (LangOpts.ObjCNonFragileABI && exprType->isObjCInterfaceType()) { 2018 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2019 << exprType << isSizeof << ExprRange; 2020 return true; 2021 } 2022 2023 return false; 2024} 2025 2026bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2027 const SourceRange &ExprRange) { 2028 E = E->IgnoreParens(); 2029 2030 // alignof decl is always ok. 2031 if (isa<DeclRefExpr>(E)) 2032 return false; 2033 2034 // Cannot know anything else if the expression is dependent. 2035 if (E->isTypeDependent()) 2036 return false; 2037 2038 if (E->getBitField()) { 2039 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2040 return true; 2041 } 2042 2043 // Alignment of a field access is always okay, so long as it isn't a 2044 // bit-field. 2045 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2046 if (isa<FieldDecl>(ME->getMemberDecl())) 2047 return false; 2048 2049 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2050} 2051 2052/// \brief Build a sizeof or alignof expression given a type operand. 2053Action::OwningExprResult 2054Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2055 SourceLocation OpLoc, 2056 bool isSizeOf, SourceRange R) { 2057 if (!TInfo) 2058 return ExprError(); 2059 2060 QualType T = TInfo->getType(); 2061 2062 if (!T->isDependentType() && 2063 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2064 return ExprError(); 2065 2066 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2067 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2068 Context.getSizeType(), OpLoc, 2069 R.getEnd())); 2070} 2071 2072/// \brief Build a sizeof or alignof expression given an expression 2073/// operand. 2074Action::OwningExprResult 2075Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2076 bool isSizeOf, SourceRange R) { 2077 // Verify that the operand is valid. 2078 bool isInvalid = false; 2079 if (E->isTypeDependent()) { 2080 // Delay type-checking for type-dependent expressions. 2081 } else if (!isSizeOf) { 2082 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2083 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2084 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2085 isInvalid = true; 2086 } else { 2087 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2088 } 2089 2090 if (isInvalid) 2091 return ExprError(); 2092 2093 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2094 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2095 Context.getSizeType(), OpLoc, 2096 R.getEnd())); 2097} 2098 2099/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2100/// the same for @c alignof and @c __alignof 2101/// Note that the ArgRange is invalid if isType is false. 2102Action::OwningExprResult 2103Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2104 void *TyOrEx, const SourceRange &ArgRange) { 2105 // If error parsing type, ignore. 2106 if (TyOrEx == 0) return ExprError(); 2107 2108 if (isType) { 2109 TypeSourceInfo *TInfo; 2110 (void) GetTypeFromParser(TyOrEx, &TInfo); 2111 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2112 } 2113 2114 Expr *ArgEx = (Expr *)TyOrEx; 2115 Action::OwningExprResult Result 2116 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2117 2118 if (Result.isInvalid()) 2119 DeleteExpr(ArgEx); 2120 2121 return move(Result); 2122} 2123 2124QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2125 if (V->isTypeDependent()) 2126 return Context.DependentTy; 2127 2128 // These operators return the element type of a complex type. 2129 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2130 return CT->getElementType(); 2131 2132 // Otherwise they pass through real integer and floating point types here. 2133 if (V->getType()->isArithmeticType()) 2134 return V->getType(); 2135 2136 // Reject anything else. 2137 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2138 << (isReal ? "__real" : "__imag"); 2139 return QualType(); 2140} 2141 2142 2143 2144Action::OwningExprResult 2145Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2146 tok::TokenKind Kind, ExprArg Input) { 2147 UnaryOperator::Opcode Opc; 2148 switch (Kind) { 2149 default: assert(0 && "Unknown unary op!"); 2150 case tok::plusplus: Opc = UnaryOperator::PostInc; break; 2151 case tok::minusminus: Opc = UnaryOperator::PostDec; break; 2152 } 2153 2154 return BuildUnaryOp(S, OpLoc, Opc, move(Input)); 2155} 2156 2157Action::OwningExprResult 2158Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc, 2159 ExprArg Idx, SourceLocation RLoc) { 2160 // Since this might be a postfix expression, get rid of ParenListExprs. 2161 Base = MaybeConvertParenListExprToParenExpr(S, move(Base)); 2162 2163 Expr *LHSExp = static_cast<Expr*>(Base.get()), 2164 *RHSExp = static_cast<Expr*>(Idx.get()); 2165 2166 if (getLangOptions().CPlusPlus && 2167 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2168 Base.release(); 2169 Idx.release(); 2170 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2171 Context.DependentTy, RLoc)); 2172 } 2173 2174 if (getLangOptions().CPlusPlus && 2175 (LHSExp->getType()->isRecordType() || 2176 LHSExp->getType()->isEnumeralType() || 2177 RHSExp->getType()->isRecordType() || 2178 RHSExp->getType()->isEnumeralType())) { 2179 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, move(Base),move(Idx)); 2180 } 2181 2182 return CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 2183} 2184 2185 2186Action::OwningExprResult 2187Sema::CreateBuiltinArraySubscriptExpr(ExprArg Base, SourceLocation LLoc, 2188 ExprArg Idx, SourceLocation RLoc) { 2189 Expr *LHSExp = static_cast<Expr*>(Base.get()); 2190 Expr *RHSExp = static_cast<Expr*>(Idx.get()); 2191 2192 // Perform default conversions. 2193 if (!LHSExp->getType()->getAs<VectorType>()) 2194 DefaultFunctionArrayLvalueConversion(LHSExp); 2195 DefaultFunctionArrayLvalueConversion(RHSExp); 2196 2197 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2198 2199 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2200 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2201 // in the subscript position. As a result, we need to derive the array base 2202 // and index from the expression types. 2203 Expr *BaseExpr, *IndexExpr; 2204 QualType ResultType; 2205 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2206 BaseExpr = LHSExp; 2207 IndexExpr = RHSExp; 2208 ResultType = Context.DependentTy; 2209 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2210 BaseExpr = LHSExp; 2211 IndexExpr = RHSExp; 2212 ResultType = PTy->getPointeeType(); 2213 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2214 // Handle the uncommon case of "123[Ptr]". 2215 BaseExpr = RHSExp; 2216 IndexExpr = LHSExp; 2217 ResultType = PTy->getPointeeType(); 2218 } else if (const ObjCObjectPointerType *PTy = 2219 LHSTy->getAs<ObjCObjectPointerType>()) { 2220 BaseExpr = LHSExp; 2221 IndexExpr = RHSExp; 2222 ResultType = PTy->getPointeeType(); 2223 } else if (const ObjCObjectPointerType *PTy = 2224 RHSTy->getAs<ObjCObjectPointerType>()) { 2225 // Handle the uncommon case of "123[Ptr]". 2226 BaseExpr = RHSExp; 2227 IndexExpr = LHSExp; 2228 ResultType = PTy->getPointeeType(); 2229 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2230 BaseExpr = LHSExp; // vectors: V[123] 2231 IndexExpr = RHSExp; 2232 2233 // FIXME: need to deal with const... 2234 ResultType = VTy->getElementType(); 2235 } else if (LHSTy->isArrayType()) { 2236 // If we see an array that wasn't promoted by 2237 // DefaultFunctionArrayLvalueConversion, it must be an array that 2238 // wasn't promoted because of the C90 rule that doesn't 2239 // allow promoting non-lvalue arrays. Warn, then 2240 // force the promotion here. 2241 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2242 LHSExp->getSourceRange(); 2243 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2244 CastExpr::CK_ArrayToPointerDecay); 2245 LHSTy = LHSExp->getType(); 2246 2247 BaseExpr = LHSExp; 2248 IndexExpr = RHSExp; 2249 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2250 } else if (RHSTy->isArrayType()) { 2251 // Same as previous, except for 123[f().a] case 2252 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2253 RHSExp->getSourceRange(); 2254 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2255 CastExpr::CK_ArrayToPointerDecay); 2256 RHSTy = RHSExp->getType(); 2257 2258 BaseExpr = RHSExp; 2259 IndexExpr = LHSExp; 2260 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2261 } else { 2262 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2263 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2264 } 2265 // C99 6.5.2.1p1 2266 if (!(IndexExpr->getType()->isIntegerType() && 2267 IndexExpr->getType()->isScalarType()) && !IndexExpr->isTypeDependent()) 2268 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2269 << IndexExpr->getSourceRange()); 2270 2271 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2272 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2273 && !IndexExpr->isTypeDependent()) 2274 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2275 2276 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2277 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2278 // type. Note that Functions are not objects, and that (in C99 parlance) 2279 // incomplete types are not object types. 2280 if (ResultType->isFunctionType()) { 2281 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2282 << ResultType << BaseExpr->getSourceRange(); 2283 return ExprError(); 2284 } 2285 2286 if (!ResultType->isDependentType() && 2287 RequireCompleteType(LLoc, ResultType, 2288 PDiag(diag::err_subscript_incomplete_type) 2289 << BaseExpr->getSourceRange())) 2290 return ExprError(); 2291 2292 // Diagnose bad cases where we step over interface counts. 2293 if (ResultType->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 2294 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2295 << ResultType << BaseExpr->getSourceRange(); 2296 return ExprError(); 2297 } 2298 2299 Base.release(); 2300 Idx.release(); 2301 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2302 ResultType, RLoc)); 2303} 2304 2305QualType Sema:: 2306CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2307 const IdentifierInfo *CompName, 2308 SourceLocation CompLoc) { 2309 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2310 // see FIXME there. 2311 // 2312 // FIXME: This logic can be greatly simplified by splitting it along 2313 // halving/not halving and reworking the component checking. 2314 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2315 2316 // The vector accessor can't exceed the number of elements. 2317 const char *compStr = CompName->getNameStart(); 2318 2319 // This flag determines whether or not the component is one of the four 2320 // special names that indicate a subset of exactly half the elements are 2321 // to be selected. 2322 bool HalvingSwizzle = false; 2323 2324 // This flag determines whether or not CompName has an 's' char prefix, 2325 // indicating that it is a string of hex values to be used as vector indices. 2326 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2327 2328 // Check that we've found one of the special components, or that the component 2329 // names must come from the same set. 2330 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2331 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2332 HalvingSwizzle = true; 2333 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2334 do 2335 compStr++; 2336 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2337 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2338 do 2339 compStr++; 2340 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2341 } 2342 2343 if (!HalvingSwizzle && *compStr) { 2344 // We didn't get to the end of the string. This means the component names 2345 // didn't come from the same set *or* we encountered an illegal name. 2346 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2347 << std::string(compStr,compStr+1) << SourceRange(CompLoc); 2348 return QualType(); 2349 } 2350 2351 // Ensure no component accessor exceeds the width of the vector type it 2352 // operates on. 2353 if (!HalvingSwizzle) { 2354 compStr = CompName->getNameStart(); 2355 2356 if (HexSwizzle) 2357 compStr++; 2358 2359 while (*compStr) { 2360 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2361 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2362 << baseType << SourceRange(CompLoc); 2363 return QualType(); 2364 } 2365 } 2366 } 2367 2368 // The component accessor looks fine - now we need to compute the actual type. 2369 // The vector type is implied by the component accessor. For example, 2370 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2371 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2372 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2373 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2374 : CompName->getLength(); 2375 if (HexSwizzle) 2376 CompSize--; 2377 2378 if (CompSize == 1) 2379 return vecType->getElementType(); 2380 2381 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2382 // Now look up the TypeDefDecl from the vector type. Without this, 2383 // diagostics look bad. We want extended vector types to appear built-in. 2384 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2385 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2386 return Context.getTypedefType(ExtVectorDecls[i]); 2387 } 2388 return VT; // should never get here (a typedef type should always be found). 2389} 2390 2391static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2392 IdentifierInfo *Member, 2393 const Selector &Sel, 2394 ASTContext &Context) { 2395 2396 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2397 return PD; 2398 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2399 return OMD; 2400 2401 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2402 E = PDecl->protocol_end(); I != E; ++I) { 2403 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2404 Context)) 2405 return D; 2406 } 2407 return 0; 2408} 2409 2410static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2411 IdentifierInfo *Member, 2412 const Selector &Sel, 2413 ASTContext &Context) { 2414 // Check protocols on qualified interfaces. 2415 Decl *GDecl = 0; 2416 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2417 E = QIdTy->qual_end(); I != E; ++I) { 2418 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2419 GDecl = PD; 2420 break; 2421 } 2422 // Also must look for a getter name which uses property syntax. 2423 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2424 GDecl = OMD; 2425 break; 2426 } 2427 } 2428 if (!GDecl) { 2429 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2430 E = QIdTy->qual_end(); I != E; ++I) { 2431 // Search in the protocol-qualifier list of current protocol. 2432 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2433 if (GDecl) 2434 return GDecl; 2435 } 2436 } 2437 return GDecl; 2438} 2439 2440Sema::OwningExprResult 2441Sema::ActOnDependentMemberExpr(ExprArg Base, QualType BaseType, 2442 bool IsArrow, SourceLocation OpLoc, 2443 const CXXScopeSpec &SS, 2444 NamedDecl *FirstQualifierInScope, 2445 DeclarationName Name, SourceLocation NameLoc, 2446 const TemplateArgumentListInfo *TemplateArgs) { 2447 Expr *BaseExpr = Base.takeAs<Expr>(); 2448 2449 // Even in dependent contexts, try to diagnose base expressions with 2450 // obviously wrong types, e.g.: 2451 // 2452 // T* t; 2453 // t.f; 2454 // 2455 // In Obj-C++, however, the above expression is valid, since it could be 2456 // accessing the 'f' property if T is an Obj-C interface. The extra check 2457 // allows this, while still reporting an error if T is a struct pointer. 2458 if (!IsArrow) { 2459 const PointerType *PT = BaseType->getAs<PointerType>(); 2460 if (PT && (!getLangOptions().ObjC1 || 2461 PT->getPointeeType()->isRecordType())) { 2462 assert(BaseExpr && "cannot happen with implicit member accesses"); 2463 Diag(NameLoc, diag::err_typecheck_member_reference_struct_union) 2464 << BaseType << BaseExpr->getSourceRange(); 2465 return ExprError(); 2466 } 2467 } 2468 2469 assert(BaseType->isDependentType() || Name.isDependentName()); 2470 2471 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2472 // must have pointer type, and the accessed type is the pointee. 2473 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2474 IsArrow, OpLoc, 2475 static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 2476 SS.getRange(), 2477 FirstQualifierInScope, 2478 Name, NameLoc, 2479 TemplateArgs)); 2480} 2481 2482/// We know that the given qualified member reference points only to 2483/// declarations which do not belong to the static type of the base 2484/// expression. Diagnose the problem. 2485static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2486 Expr *BaseExpr, 2487 QualType BaseType, 2488 const CXXScopeSpec &SS, 2489 const LookupResult &R) { 2490 // If this is an implicit member access, use a different set of 2491 // diagnostics. 2492 if (!BaseExpr) 2493 return DiagnoseInstanceReference(SemaRef, SS, R); 2494 2495 // FIXME: this is an exceedingly lame diagnostic for some of the more 2496 // complicated cases here. 2497 DeclContext *DC = R.getRepresentativeDecl()->getDeclContext(); 2498 SemaRef.Diag(R.getNameLoc(), diag::err_not_direct_base_or_virtual) 2499 << SS.getRange() << DC << BaseType; 2500} 2501 2502// Check whether the declarations we found through a nested-name 2503// specifier in a member expression are actually members of the base 2504// type. The restriction here is: 2505// 2506// C++ [expr.ref]p2: 2507// ... In these cases, the id-expression shall name a 2508// member of the class or of one of its base classes. 2509// 2510// So it's perfectly legitimate for the nested-name specifier to name 2511// an unrelated class, and for us to find an overload set including 2512// decls from classes which are not superclasses, as long as the decl 2513// we actually pick through overload resolution is from a superclass. 2514bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2515 QualType BaseType, 2516 const CXXScopeSpec &SS, 2517 const LookupResult &R) { 2518 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2519 if (!BaseRT) { 2520 // We can't check this yet because the base type is still 2521 // dependent. 2522 assert(BaseType->isDependentType()); 2523 return false; 2524 } 2525 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2526 2527 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2528 // If this is an implicit member reference and we find a 2529 // non-instance member, it's not an error. 2530 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2531 return false; 2532 2533 // Note that we use the DC of the decl, not the underlying decl. 2534 CXXRecordDecl *RecordD = cast<CXXRecordDecl>((*I)->getDeclContext()); 2535 while (RecordD->isAnonymousStructOrUnion()) 2536 RecordD = cast<CXXRecordDecl>(RecordD->getParent()); 2537 2538 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2539 MemberRecord.insert(RecordD->getCanonicalDecl()); 2540 2541 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2542 return false; 2543 } 2544 2545 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2546 return true; 2547} 2548 2549static bool 2550LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2551 SourceRange BaseRange, const RecordType *RTy, 2552 SourceLocation OpLoc, const CXXScopeSpec &SS) { 2553 RecordDecl *RDecl = RTy->getDecl(); 2554 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2555 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2556 << BaseRange)) 2557 return true; 2558 2559 DeclContext *DC = RDecl; 2560 if (SS.isSet()) { 2561 // If the member name was a qualified-id, look into the 2562 // nested-name-specifier. 2563 DC = SemaRef.computeDeclContext(SS, false); 2564 2565 if (SemaRef.RequireCompleteDeclContext(SS)) { 2566 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2567 << SS.getRange() << DC; 2568 return true; 2569 } 2570 2571 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2572 2573 if (!isa<TypeDecl>(DC)) { 2574 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2575 << DC << SS.getRange(); 2576 return true; 2577 } 2578 } 2579 2580 // The record definition is complete, now look up the member. 2581 SemaRef.LookupQualifiedName(R, DC); 2582 2583 if (!R.empty()) 2584 return false; 2585 2586 // We didn't find anything with the given name, so try to correct 2587 // for typos. 2588 DeclarationName Name = R.getLookupName(); 2589 if (SemaRef.CorrectTypo(R, 0, &SS, DC) && 2590 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2591 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2592 << Name << DC << R.getLookupName() << SS.getRange() 2593 << FixItHint::CreateReplacement(R.getNameLoc(), 2594 R.getLookupName().getAsString()); 2595 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2596 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2597 << ND->getDeclName(); 2598 return false; 2599 } else { 2600 R.clear(); 2601 } 2602 2603 return false; 2604} 2605 2606Sema::OwningExprResult 2607Sema::BuildMemberReferenceExpr(ExprArg BaseArg, QualType BaseType, 2608 SourceLocation OpLoc, bool IsArrow, 2609 const CXXScopeSpec &SS, 2610 NamedDecl *FirstQualifierInScope, 2611 DeclarationName Name, SourceLocation NameLoc, 2612 const TemplateArgumentListInfo *TemplateArgs) { 2613 Expr *Base = BaseArg.takeAs<Expr>(); 2614 2615 if (BaseType->isDependentType() || 2616 (SS.isSet() && isDependentScopeSpecifier(SS))) 2617 return ActOnDependentMemberExpr(ExprArg(*this, Base), BaseType, 2618 IsArrow, OpLoc, 2619 SS, FirstQualifierInScope, 2620 Name, NameLoc, 2621 TemplateArgs); 2622 2623 LookupResult R(*this, Name, NameLoc, LookupMemberName); 2624 2625 // Implicit member accesses. 2626 if (!Base) { 2627 QualType RecordTy = BaseType; 2628 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2629 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2630 RecordTy->getAs<RecordType>(), 2631 OpLoc, SS)) 2632 return ExprError(); 2633 2634 // Explicit member accesses. 2635 } else { 2636 OwningExprResult Result = 2637 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2638 SS, /*ObjCImpDecl*/ DeclPtrTy()); 2639 2640 if (Result.isInvalid()) { 2641 Owned(Base); 2642 return ExprError(); 2643 } 2644 2645 if (Result.get()) 2646 return move(Result); 2647 } 2648 2649 return BuildMemberReferenceExpr(ExprArg(*this, Base), BaseType, 2650 OpLoc, IsArrow, SS, FirstQualifierInScope, 2651 R, TemplateArgs); 2652} 2653 2654Sema::OwningExprResult 2655Sema::BuildMemberReferenceExpr(ExprArg Base, QualType BaseExprType, 2656 SourceLocation OpLoc, bool IsArrow, 2657 const CXXScopeSpec &SS, 2658 NamedDecl *FirstQualifierInScope, 2659 LookupResult &R, 2660 const TemplateArgumentListInfo *TemplateArgs) { 2661 Expr *BaseExpr = Base.takeAs<Expr>(); 2662 QualType BaseType = BaseExprType; 2663 if (IsArrow) { 2664 assert(BaseType->isPointerType()); 2665 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2666 } 2667 R.setBaseObjectType(BaseType); 2668 2669 NestedNameSpecifier *Qualifier = 2670 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 2671 DeclarationName MemberName = R.getLookupName(); 2672 SourceLocation MemberLoc = R.getNameLoc(); 2673 2674 if (R.isAmbiguous()) 2675 return ExprError(); 2676 2677 if (R.empty()) { 2678 // Rederive where we looked up. 2679 DeclContext *DC = (SS.isSet() 2680 ? computeDeclContext(SS, false) 2681 : BaseType->getAs<RecordType>()->getDecl()); 2682 2683 Diag(R.getNameLoc(), diag::err_no_member) 2684 << MemberName << DC 2685 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2686 return ExprError(); 2687 } 2688 2689 // Diagnose lookups that find only declarations from a non-base 2690 // type. This is possible for either qualified lookups (which may 2691 // have been qualified with an unrelated type) or implicit member 2692 // expressions (which were found with unqualified lookup and thus 2693 // may have come from an enclosing scope). Note that it's okay for 2694 // lookup to find declarations from a non-base type as long as those 2695 // aren't the ones picked by overload resolution. 2696 if ((SS.isSet() || !BaseExpr || 2697 (isa<CXXThisExpr>(BaseExpr) && 2698 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2699 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2700 return ExprError(); 2701 2702 // Construct an unresolved result if we in fact got an unresolved 2703 // result. 2704 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2705 bool Dependent = 2706 BaseExprType->isDependentType() || 2707 R.isUnresolvableResult() || 2708 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2709 2710 // Suppress any lookup-related diagnostics; we'll do these when we 2711 // pick a member. 2712 R.suppressDiagnostics(); 2713 2714 UnresolvedMemberExpr *MemExpr 2715 = UnresolvedMemberExpr::Create(Context, Dependent, 2716 R.isUnresolvableResult(), 2717 BaseExpr, BaseExprType, 2718 IsArrow, OpLoc, 2719 Qualifier, SS.getRange(), 2720 MemberName, MemberLoc, 2721 TemplateArgs); 2722 MemExpr->addDecls(R.begin(), R.end()); 2723 2724 return Owned(MemExpr); 2725 } 2726 2727 assert(R.isSingleResult()); 2728 DeclAccessPair FoundDecl = R.begin().getPair(); 2729 NamedDecl *MemberDecl = R.getFoundDecl(); 2730 2731 // FIXME: diagnose the presence of template arguments now. 2732 2733 // If the decl being referenced had an error, return an error for this 2734 // sub-expr without emitting another error, in order to avoid cascading 2735 // error cases. 2736 if (MemberDecl->isInvalidDecl()) 2737 return ExprError(); 2738 2739 // Handle the implicit-member-access case. 2740 if (!BaseExpr) { 2741 // If this is not an instance member, convert to a non-member access. 2742 if (!MemberDecl->isCXXInstanceMember()) 2743 return BuildDeclarationNameExpr(SS, R.getNameLoc(), MemberDecl); 2744 2745 SourceLocation Loc = R.getNameLoc(); 2746 if (SS.getRange().isValid()) 2747 Loc = SS.getRange().getBegin(); 2748 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2749 } 2750 2751 bool ShouldCheckUse = true; 2752 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2753 // Don't diagnose the use of a virtual member function unless it's 2754 // explicitly qualified. 2755 if (MD->isVirtual() && !SS.isSet()) 2756 ShouldCheckUse = false; 2757 } 2758 2759 // Check the use of this member. 2760 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2761 Owned(BaseExpr); 2762 return ExprError(); 2763 } 2764 2765 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2766 // We may have found a field within an anonymous union or struct 2767 // (C++ [class.union]). 2768 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2769 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2770 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2771 BaseExpr, OpLoc); 2772 2773 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2774 QualType MemberType = FD->getType(); 2775 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2776 MemberType = Ref->getPointeeType(); 2777 else { 2778 Qualifiers BaseQuals = BaseType.getQualifiers(); 2779 BaseQuals.removeObjCGCAttr(); 2780 if (FD->isMutable()) BaseQuals.removeConst(); 2781 2782 Qualifiers MemberQuals 2783 = Context.getCanonicalType(MemberType).getQualifiers(); 2784 2785 Qualifiers Combined = BaseQuals + MemberQuals; 2786 if (Combined != MemberQuals) 2787 MemberType = Context.getQualifiedType(MemberType, Combined); 2788 } 2789 2790 MarkDeclarationReferenced(MemberLoc, FD); 2791 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2792 return ExprError(); 2793 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2794 FD, FoundDecl, MemberLoc, MemberType)); 2795 } 2796 2797 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2798 MarkDeclarationReferenced(MemberLoc, Var); 2799 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2800 Var, FoundDecl, MemberLoc, 2801 Var->getType().getNonReferenceType())); 2802 } 2803 2804 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2805 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2806 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2807 MemberFn, FoundDecl, MemberLoc, 2808 MemberFn->getType())); 2809 } 2810 2811 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2812 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2813 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2814 Enum, FoundDecl, MemberLoc, Enum->getType())); 2815 } 2816 2817 Owned(BaseExpr); 2818 2819 if (isa<TypeDecl>(MemberDecl)) 2820 return ExprError(Diag(MemberLoc,diag::err_typecheck_member_reference_type) 2821 << MemberName << int(IsArrow)); 2822 2823 // We found a declaration kind that we didn't expect. This is a 2824 // generic error message that tells the user that she can't refer 2825 // to this member with '.' or '->'. 2826 return ExprError(Diag(MemberLoc, 2827 diag::err_typecheck_member_reference_unknown) 2828 << MemberName << int(IsArrow)); 2829} 2830 2831/// Look up the given member of the given non-type-dependent 2832/// expression. This can return in one of two ways: 2833/// * If it returns a sentinel null-but-valid result, the caller will 2834/// assume that lookup was performed and the results written into 2835/// the provided structure. It will take over from there. 2836/// * Otherwise, the returned expression will be produced in place of 2837/// an ordinary member expression. 2838/// 2839/// The ObjCImpDecl bit is a gross hack that will need to be properly 2840/// fixed for ObjC++. 2841Sema::OwningExprResult 2842Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2843 bool &IsArrow, SourceLocation OpLoc, 2844 const CXXScopeSpec &SS, 2845 DeclPtrTy ObjCImpDecl) { 2846 assert(BaseExpr && "no base expression"); 2847 2848 // Perform default conversions. 2849 DefaultFunctionArrayConversion(BaseExpr); 2850 2851 QualType BaseType = BaseExpr->getType(); 2852 assert(!BaseType->isDependentType()); 2853 2854 DeclarationName MemberName = R.getLookupName(); 2855 SourceLocation MemberLoc = R.getNameLoc(); 2856 2857 // If the user is trying to apply -> or . to a function pointer 2858 // type, it's probably because they forgot parentheses to call that 2859 // function. Suggest the addition of those parentheses, build the 2860 // call, and continue on. 2861 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 2862 if (const FunctionProtoType *Fun 2863 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 2864 QualType ResultTy = Fun->getResultType(); 2865 if (Fun->getNumArgs() == 0 && 2866 ((!IsArrow && ResultTy->isRecordType()) || 2867 (IsArrow && ResultTy->isPointerType() && 2868 ResultTy->getAs<PointerType>()->getPointeeType() 2869 ->isRecordType()))) { 2870 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 2871 Diag(Loc, diag::err_member_reference_needs_call) 2872 << QualType(Fun, 0) 2873 << FixItHint::CreateInsertion(Loc, "()"); 2874 2875 OwningExprResult NewBase 2876 = ActOnCallExpr(0, ExprArg(*this, BaseExpr), Loc, 2877 MultiExprArg(*this, 0, 0), 0, Loc); 2878 if (NewBase.isInvalid()) 2879 return ExprError(); 2880 2881 BaseExpr = NewBase.takeAs<Expr>(); 2882 DefaultFunctionArrayConversion(BaseExpr); 2883 BaseType = BaseExpr->getType(); 2884 } 2885 } 2886 } 2887 2888 // If this is an Objective-C pseudo-builtin and a definition is provided then 2889 // use that. 2890 if (BaseType->isObjCIdType()) { 2891 if (IsArrow) { 2892 // Handle the following exceptional case PObj->isa. 2893 if (const ObjCObjectPointerType *OPT = 2894 BaseType->getAs<ObjCObjectPointerType>()) { 2895 if (OPT->getPointeeType()->isSpecificBuiltinType(BuiltinType::ObjCId) && 2896 MemberName.getAsIdentifierInfo()->isStr("isa")) 2897 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 2898 Context.getObjCClassType())); 2899 } 2900 } 2901 // We have an 'id' type. Rather than fall through, we check if this 2902 // is a reference to 'isa'. 2903 if (BaseType != Context.ObjCIdRedefinitionType) { 2904 BaseType = Context.ObjCIdRedefinitionType; 2905 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2906 } 2907 } 2908 2909 // If this is an Objective-C pseudo-builtin and a definition is provided then 2910 // use that. 2911 if (Context.isObjCSelType(BaseType)) { 2912 // We have an 'SEL' type. Rather than fall through, we check if this 2913 // is a reference to 'sel_id'. 2914 if (BaseType != Context.ObjCSelRedefinitionType) { 2915 BaseType = Context.ObjCSelRedefinitionType; 2916 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2917 } 2918 } 2919 2920 assert(!BaseType.isNull() && "no type for member expression"); 2921 2922 // Handle properties on ObjC 'Class' types. 2923 if (!IsArrow && BaseType->isObjCClassType()) { 2924 // Also must look for a getter name which uses property syntax. 2925 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 2926 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 2927 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2928 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 2929 ObjCMethodDecl *Getter; 2930 // FIXME: need to also look locally in the implementation. 2931 if ((Getter = IFace->lookupClassMethod(Sel))) { 2932 // Check the use of this method. 2933 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 2934 return ExprError(); 2935 } 2936 // If we found a getter then this may be a valid dot-reference, we 2937 // will look for the matching setter, in case it is needed. 2938 Selector SetterSel = 2939 SelectorTable::constructSetterName(PP.getIdentifierTable(), 2940 PP.getSelectorTable(), Member); 2941 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 2942 if (!Setter) { 2943 // If this reference is in an @implementation, also check for 'private' 2944 // methods. 2945 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 2946 } 2947 // Look through local category implementations associated with the class. 2948 if (!Setter) 2949 Setter = IFace->getCategoryClassMethod(SetterSel); 2950 2951 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 2952 return ExprError(); 2953 2954 if (Getter || Setter) { 2955 QualType PType; 2956 2957 if (Getter) 2958 PType = Getter->getResultType(); 2959 else 2960 // Get the expression type from Setter's incoming parameter. 2961 PType = (*(Setter->param_end() -1))->getType(); 2962 // FIXME: we must check that the setter has property type. 2963 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 2964 PType, 2965 Setter, MemberLoc, BaseExpr)); 2966 } 2967 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 2968 << MemberName << BaseType); 2969 } 2970 } 2971 2972 if (BaseType->isObjCClassType() && 2973 BaseType != Context.ObjCClassRedefinitionType) { 2974 BaseType = Context.ObjCClassRedefinitionType; 2975 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2976 } 2977 2978 if (IsArrow) { 2979 if (const PointerType *PT = BaseType->getAs<PointerType>()) 2980 BaseType = PT->getPointeeType(); 2981 else if (BaseType->isObjCObjectPointerType()) 2982 ; 2983 else if (BaseType->isRecordType()) { 2984 // Recover from arrow accesses to records, e.g.: 2985 // struct MyRecord foo; 2986 // foo->bar 2987 // This is actually well-formed in C++ if MyRecord has an 2988 // overloaded operator->, but that should have been dealt with 2989 // by now. 2990 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 2991 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 2992 << FixItHint::CreateReplacement(OpLoc, "."); 2993 IsArrow = false; 2994 } else { 2995 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 2996 << BaseType << BaseExpr->getSourceRange(); 2997 return ExprError(); 2998 } 2999 } else { 3000 // Recover from dot accesses to pointers, e.g.: 3001 // type *foo; 3002 // foo.bar 3003 // This is actually well-formed in two cases: 3004 // - 'type' is an Objective C type 3005 // - 'bar' is a pseudo-destructor name which happens to refer to 3006 // the appropriate pointer type 3007 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3008 const PointerType *PT = BaseType->getAs<PointerType>(); 3009 if (PT && PT->getPointeeType()->isRecordType()) { 3010 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3011 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3012 << FixItHint::CreateReplacement(OpLoc, "->"); 3013 BaseType = PT->getPointeeType(); 3014 IsArrow = true; 3015 } 3016 } 3017 } 3018 3019 // Handle field access to simple records. This also handles access 3020 // to fields of the ObjC 'id' struct. 3021 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3022 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3023 RTy, OpLoc, SS)) 3024 return ExprError(); 3025 return Owned((Expr*) 0); 3026 } 3027 3028 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3029 // (*Obj).ivar. 3030 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3031 (!IsArrow && BaseType->isObjCInterfaceType())) { 3032 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3033 const ObjCInterfaceType *IFaceT = 3034 OPT ? OPT->getInterfaceType() : BaseType->getAs<ObjCInterfaceType>(); 3035 if (IFaceT) { 3036 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3037 3038 ObjCInterfaceDecl *IDecl = IFaceT->getDecl(); 3039 ObjCInterfaceDecl *ClassDeclared; 3040 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3041 3042 if (!IV) { 3043 // Attempt to correct for typos in ivar names. 3044 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3045 LookupMemberName); 3046 if (CorrectTypo(Res, 0, 0, IDecl) && 3047 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3048 Diag(R.getNameLoc(), 3049 diag::err_typecheck_member_reference_ivar_suggest) 3050 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3051 << FixItHint::CreateReplacement(R.getNameLoc(), 3052 IV->getNameAsString()); 3053 Diag(IV->getLocation(), diag::note_previous_decl) 3054 << IV->getDeclName(); 3055 } 3056 } 3057 3058 if (IV) { 3059 // If the decl being referenced had an error, return an error for this 3060 // sub-expr without emitting another error, in order to avoid cascading 3061 // error cases. 3062 if (IV->isInvalidDecl()) 3063 return ExprError(); 3064 3065 // Check whether we can reference this field. 3066 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3067 return ExprError(); 3068 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3069 IV->getAccessControl() != ObjCIvarDecl::Package) { 3070 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3071 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3072 ClassOfMethodDecl = MD->getClassInterface(); 3073 else if (ObjCImpDecl && getCurFunctionDecl()) { 3074 // Case of a c-function declared inside an objc implementation. 3075 // FIXME: For a c-style function nested inside an objc implementation 3076 // class, there is no implementation context available, so we pass 3077 // down the context as argument to this routine. Ideally, this context 3078 // need be passed down in the AST node and somehow calculated from the 3079 // AST for a function decl. 3080 Decl *ImplDecl = ObjCImpDecl.getAs<Decl>(); 3081 if (ObjCImplementationDecl *IMPD = 3082 dyn_cast<ObjCImplementationDecl>(ImplDecl)) 3083 ClassOfMethodDecl = IMPD->getClassInterface(); 3084 else if (ObjCCategoryImplDecl* CatImplClass = 3085 dyn_cast<ObjCCategoryImplDecl>(ImplDecl)) 3086 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3087 } 3088 3089 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3090 if (ClassDeclared != IDecl || 3091 ClassOfMethodDecl != ClassDeclared) 3092 Diag(MemberLoc, diag::error_private_ivar_access) 3093 << IV->getDeclName(); 3094 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3095 // @protected 3096 Diag(MemberLoc, diag::error_protected_ivar_access) 3097 << IV->getDeclName(); 3098 } 3099 3100 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3101 MemberLoc, BaseExpr, 3102 IsArrow)); 3103 } 3104 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3105 << IDecl->getDeclName() << MemberName 3106 << BaseExpr->getSourceRange()); 3107 } 3108 } 3109 // Handle properties on 'id' and qualified "id". 3110 if (!IsArrow && (BaseType->isObjCIdType() || 3111 BaseType->isObjCQualifiedIdType())) { 3112 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3113 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3114 3115 // Check protocols on qualified interfaces. 3116 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3117 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3118 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3119 // Check the use of this declaration 3120 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3121 return ExprError(); 3122 3123 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3124 MemberLoc, BaseExpr)); 3125 } 3126 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3127 // Check the use of this method. 3128 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3129 return ExprError(); 3130 3131 return Owned(new (Context) ObjCMessageExpr(Context, BaseExpr, Sel, 3132 OMD->getResultType(), 3133 OMD, OpLoc, MemberLoc, 3134 NULL, 0)); 3135 } 3136 } 3137 3138 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3139 << MemberName << BaseType); 3140 } 3141 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3142 // pointer to a (potentially qualified) interface type. 3143 const ObjCObjectPointerType *OPT; 3144 if (!IsArrow && (OPT = BaseType->getAsObjCInterfacePointerType())) { 3145 const ObjCInterfaceType *IFaceT = OPT->getInterfaceType(); 3146 ObjCInterfaceDecl *IFace = IFaceT->getDecl(); 3147 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3148 3149 // Search for a declared property first. 3150 if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) { 3151 // Check whether we can reference this property. 3152 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3153 return ExprError(); 3154 QualType ResTy = PD->getType(); 3155 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3156 ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel); 3157 if (DiagnosePropertyAccessorMismatch(PD, Getter, MemberLoc)) 3158 ResTy = Getter->getResultType(); 3159 return Owned(new (Context) ObjCPropertyRefExpr(PD, ResTy, 3160 MemberLoc, BaseExpr)); 3161 } 3162 // Check protocols on qualified interfaces. 3163 for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(), 3164 E = OPT->qual_end(); I != E; ++I) 3165 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 3166 // Check whether we can reference this property. 3167 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3168 return ExprError(); 3169 3170 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3171 MemberLoc, BaseExpr)); 3172 } 3173 // If that failed, look for an "implicit" property by seeing if the nullary 3174 // selector is implemented. 3175 3176 // FIXME: The logic for looking up nullary and unary selectors should be 3177 // shared with the code in ActOnInstanceMessage. 3178 3179 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3180 ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel); 3181 3182 // If this reference is in an @implementation, check for 'private' methods. 3183 if (!Getter) 3184 Getter = IFace->lookupPrivateInstanceMethod(Sel); 3185 3186 // Look through local category implementations associated with the class. 3187 if (!Getter) 3188 Getter = IFace->getCategoryInstanceMethod(Sel); 3189 if (Getter) { 3190 // Check if we can reference this property. 3191 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3192 return ExprError(); 3193 } 3194 // If we found a getter then this may be a valid dot-reference, we 3195 // will look for the matching setter, in case it is needed. 3196 Selector SetterSel = 3197 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3198 PP.getSelectorTable(), Member); 3199 ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel); 3200 if (!Setter) { 3201 // If this reference is in an @implementation, also check for 'private' 3202 // methods. 3203 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3204 } 3205 // Look through local category implementations associated with the class. 3206 if (!Setter) 3207 Setter = IFace->getCategoryInstanceMethod(SetterSel); 3208 3209 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3210 return ExprError(); 3211 3212 if (Getter) { 3213 QualType PType; 3214 PType = Getter->getResultType(); 3215 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, PType, 3216 Setter, MemberLoc, BaseExpr)); 3217 } 3218 3219 // Attempt to correct for typos in property names. 3220 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3221 LookupOrdinaryName); 3222 if (CorrectTypo(Res, 0, 0, IFace, false, OPT) && 3223 Res.getAsSingle<ObjCPropertyDecl>()) { 3224 Diag(R.getNameLoc(), diag::err_property_not_found_suggest) 3225 << MemberName << BaseType << Res.getLookupName() 3226 << FixItHint::CreateReplacement(R.getNameLoc(), 3227 Res.getLookupName().getAsString()); 3228 ObjCPropertyDecl *Property = Res.getAsSingle<ObjCPropertyDecl>(); 3229 Diag(Property->getLocation(), diag::note_previous_decl) 3230 << Property->getDeclName(); 3231 3232 return LookupMemberExpr(Res, BaseExpr, IsArrow, OpLoc, SS, 3233 ObjCImpDecl); 3234 } 3235 Diag(MemberLoc, diag::err_property_not_found) 3236 << MemberName << BaseType; 3237 if (Setter && !Getter) 3238 Diag(Setter->getLocation(), diag::note_getter_unavailable) 3239 << MemberName << BaseExpr->getSourceRange(); 3240 return ExprError(); 3241 } 3242 3243 // Handle the following exceptional case (*Obj).isa. 3244 if (!IsArrow && 3245 BaseType->isSpecificBuiltinType(BuiltinType::ObjCId) && 3246 MemberName.getAsIdentifierInfo()->isStr("isa")) 3247 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3248 Context.getObjCClassType())); 3249 3250 // Handle 'field access' to vectors, such as 'V.xx'. 3251 if (BaseType->isExtVectorType()) { 3252 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3253 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3254 if (ret.isNull()) 3255 return ExprError(); 3256 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3257 MemberLoc)); 3258 } 3259 3260 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3261 << BaseType << BaseExpr->getSourceRange(); 3262 3263 return ExprError(); 3264} 3265 3266/// The main callback when the parser finds something like 3267/// expression . [nested-name-specifier] identifier 3268/// expression -> [nested-name-specifier] identifier 3269/// where 'identifier' encompasses a fairly broad spectrum of 3270/// possibilities, including destructor and operator references. 3271/// 3272/// \param OpKind either tok::arrow or tok::period 3273/// \param HasTrailingLParen whether the next token is '(', which 3274/// is used to diagnose mis-uses of special members that can 3275/// only be called 3276/// \param ObjCImpDecl the current ObjC @implementation decl; 3277/// this is an ugly hack around the fact that ObjC @implementations 3278/// aren't properly put in the context chain 3279Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, ExprArg BaseArg, 3280 SourceLocation OpLoc, 3281 tok::TokenKind OpKind, 3282 const CXXScopeSpec &SS, 3283 UnqualifiedId &Id, 3284 DeclPtrTy ObjCImpDecl, 3285 bool HasTrailingLParen) { 3286 if (SS.isSet() && SS.isInvalid()) 3287 return ExprError(); 3288 3289 TemplateArgumentListInfo TemplateArgsBuffer; 3290 3291 // Decompose the name into its component parts. 3292 DeclarationName Name; 3293 SourceLocation NameLoc; 3294 const TemplateArgumentListInfo *TemplateArgs; 3295 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3296 Name, NameLoc, TemplateArgs); 3297 3298 bool IsArrow = (OpKind == tok::arrow); 3299 3300 NamedDecl *FirstQualifierInScope 3301 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3302 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3303 3304 // This is a postfix expression, so get rid of ParenListExprs. 3305 BaseArg = MaybeConvertParenListExprToParenExpr(S, move(BaseArg)); 3306 3307 Expr *Base = BaseArg.takeAs<Expr>(); 3308 OwningExprResult Result(*this); 3309 if (Base->getType()->isDependentType() || Name.isDependentName()) { 3310 Result = ActOnDependentMemberExpr(ExprArg(*this, Base), Base->getType(), 3311 IsArrow, OpLoc, 3312 SS, FirstQualifierInScope, 3313 Name, NameLoc, 3314 TemplateArgs); 3315 } else { 3316 LookupResult R(*this, Name, NameLoc, LookupMemberName); 3317 if (TemplateArgs) { 3318 // Re-use the lookup done for the template name. 3319 DecomposeTemplateName(R, Id); 3320 } else { 3321 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3322 SS, ObjCImpDecl); 3323 3324 if (Result.isInvalid()) { 3325 Owned(Base); 3326 return ExprError(); 3327 } 3328 3329 if (Result.get()) { 3330 // The only way a reference to a destructor can be used is to 3331 // immediately call it, which falls into this case. If the 3332 // next token is not a '(', produce a diagnostic and build the 3333 // call now. 3334 if (!HasTrailingLParen && 3335 Id.getKind() == UnqualifiedId::IK_DestructorName) 3336 return DiagnoseDtorReference(NameLoc, move(Result)); 3337 3338 return move(Result); 3339 } 3340 } 3341 3342 Result = BuildMemberReferenceExpr(ExprArg(*this, Base), Base->getType(), 3343 OpLoc, IsArrow, SS, FirstQualifierInScope, 3344 R, TemplateArgs); 3345 } 3346 3347 return move(Result); 3348} 3349 3350Sema::OwningExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3351 FunctionDecl *FD, 3352 ParmVarDecl *Param) { 3353 if (Param->hasUnparsedDefaultArg()) { 3354 Diag (CallLoc, 3355 diag::err_use_of_default_argument_to_function_declared_later) << 3356 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3357 Diag(UnparsedDefaultArgLocs[Param], 3358 diag::note_default_argument_declared_here); 3359 } else { 3360 if (Param->hasUninstantiatedDefaultArg()) { 3361 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3362 3363 // Instantiate the expression. 3364 MultiLevelTemplateArgumentList ArgList 3365 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3366 3367 InstantiatingTemplate Inst(*this, CallLoc, Param, 3368 ArgList.getInnermost().getFlatArgumentList(), 3369 ArgList.getInnermost().flat_size()); 3370 3371 OwningExprResult Result = SubstExpr(UninstExpr, ArgList); 3372 if (Result.isInvalid()) 3373 return ExprError(); 3374 3375 // Check the expression as an initializer for the parameter. 3376 InitializedEntity Entity 3377 = InitializedEntity::InitializeParameter(Param); 3378 InitializationKind Kind 3379 = InitializationKind::CreateCopy(Param->getLocation(), 3380 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3381 Expr *ResultE = Result.takeAs<Expr>(); 3382 3383 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3384 Result = InitSeq.Perform(*this, Entity, Kind, 3385 MultiExprArg(*this, (void**)&ResultE, 1)); 3386 if (Result.isInvalid()) 3387 return ExprError(); 3388 3389 // Build the default argument expression. 3390 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3391 Result.takeAs<Expr>())); 3392 } 3393 3394 // If the default expression creates temporaries, we need to 3395 // push them to the current stack of expression temporaries so they'll 3396 // be properly destroyed. 3397 // FIXME: We should really be rebuilding the default argument with new 3398 // bound temporaries; see the comment in PR5810. 3399 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3400 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3401 } 3402 3403 // We already type-checked the argument, so we know it works. 3404 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3405} 3406 3407/// ConvertArgumentsForCall - Converts the arguments specified in 3408/// Args/NumArgs to the parameter types of the function FDecl with 3409/// function prototype Proto. Call is the call expression itself, and 3410/// Fn is the function expression. For a C++ member function, this 3411/// routine does not attempt to convert the object argument. Returns 3412/// true if the call is ill-formed. 3413bool 3414Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3415 FunctionDecl *FDecl, 3416 const FunctionProtoType *Proto, 3417 Expr **Args, unsigned NumArgs, 3418 SourceLocation RParenLoc) { 3419 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3420 // assignment, to the types of the corresponding parameter, ... 3421 unsigned NumArgsInProto = Proto->getNumArgs(); 3422 bool Invalid = false; 3423 3424 // If too few arguments are available (and we don't have default 3425 // arguments for the remaining parameters), don't make the call. 3426 if (NumArgs < NumArgsInProto) { 3427 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3428 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3429 << Fn->getType()->isBlockPointerType() << Fn->getSourceRange(); 3430 Call->setNumArgs(Context, NumArgsInProto); 3431 } 3432 3433 // If too many are passed and not variadic, error on the extras and drop 3434 // them. 3435 if (NumArgs > NumArgsInProto) { 3436 if (!Proto->isVariadic()) { 3437 Diag(Args[NumArgsInProto]->getLocStart(), 3438 diag::err_typecheck_call_too_many_args) 3439 << Fn->getType()->isBlockPointerType() << Fn->getSourceRange() 3440 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3441 Args[NumArgs-1]->getLocEnd()); 3442 // This deletes the extra arguments. 3443 Call->setNumArgs(Context, NumArgsInProto); 3444 return true; 3445 } 3446 } 3447 llvm::SmallVector<Expr *, 8> AllArgs; 3448 VariadicCallType CallType = 3449 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3450 if (Fn->getType()->isBlockPointerType()) 3451 CallType = VariadicBlock; // Block 3452 else if (isa<MemberExpr>(Fn)) 3453 CallType = VariadicMethod; 3454 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3455 Proto, 0, Args, NumArgs, AllArgs, CallType); 3456 if (Invalid) 3457 return true; 3458 unsigned TotalNumArgs = AllArgs.size(); 3459 for (unsigned i = 0; i < TotalNumArgs; ++i) 3460 Call->setArg(i, AllArgs[i]); 3461 3462 return false; 3463} 3464 3465bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3466 FunctionDecl *FDecl, 3467 const FunctionProtoType *Proto, 3468 unsigned FirstProtoArg, 3469 Expr **Args, unsigned NumArgs, 3470 llvm::SmallVector<Expr *, 8> &AllArgs, 3471 VariadicCallType CallType) { 3472 unsigned NumArgsInProto = Proto->getNumArgs(); 3473 unsigned NumArgsToCheck = NumArgs; 3474 bool Invalid = false; 3475 if (NumArgs != NumArgsInProto) 3476 // Use default arguments for missing arguments 3477 NumArgsToCheck = NumArgsInProto; 3478 unsigned ArgIx = 0; 3479 // Continue to check argument types (even if we have too few/many args). 3480 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3481 QualType ProtoArgType = Proto->getArgType(i); 3482 3483 Expr *Arg; 3484 if (ArgIx < NumArgs) { 3485 Arg = Args[ArgIx++]; 3486 3487 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3488 ProtoArgType, 3489 PDiag(diag::err_call_incomplete_argument) 3490 << Arg->getSourceRange())) 3491 return true; 3492 3493 // Pass the argument 3494 ParmVarDecl *Param = 0; 3495 if (FDecl && i < FDecl->getNumParams()) 3496 Param = FDecl->getParamDecl(i); 3497 3498 3499 InitializedEntity Entity = 3500 Param? InitializedEntity::InitializeParameter(Param) 3501 : InitializedEntity::InitializeParameter(ProtoArgType); 3502 OwningExprResult ArgE = PerformCopyInitialization(Entity, 3503 SourceLocation(), 3504 Owned(Arg)); 3505 if (ArgE.isInvalid()) 3506 return true; 3507 3508 Arg = ArgE.takeAs<Expr>(); 3509 } else { 3510 ParmVarDecl *Param = FDecl->getParamDecl(i); 3511 3512 OwningExprResult ArgExpr = 3513 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3514 if (ArgExpr.isInvalid()) 3515 return true; 3516 3517 Arg = ArgExpr.takeAs<Expr>(); 3518 } 3519 AllArgs.push_back(Arg); 3520 } 3521 3522 // If this is a variadic call, handle args passed through "...". 3523 if (CallType != VariadicDoesNotApply) { 3524 // Promote the arguments (C99 6.5.2.2p7). 3525 for (unsigned i = ArgIx; i < NumArgs; i++) { 3526 Expr *Arg = Args[i]; 3527 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType); 3528 AllArgs.push_back(Arg); 3529 } 3530 } 3531 return Invalid; 3532} 3533 3534/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3535/// This provides the location of the left/right parens and a list of comma 3536/// locations. 3537Action::OwningExprResult 3538Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc, 3539 MultiExprArg args, 3540 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3541 unsigned NumArgs = args.size(); 3542 3543 // Since this might be a postfix expression, get rid of ParenListExprs. 3544 fn = MaybeConvertParenListExprToParenExpr(S, move(fn)); 3545 3546 Expr *Fn = fn.takeAs<Expr>(); 3547 Expr **Args = reinterpret_cast<Expr**>(args.release()); 3548 assert(Fn && "no function call expression"); 3549 3550 if (getLangOptions().CPlusPlus) { 3551 // If this is a pseudo-destructor expression, build the call immediately. 3552 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3553 if (NumArgs > 0) { 3554 // Pseudo-destructor calls should not have any arguments. 3555 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3556 << FixItHint::CreateRemoval( 3557 SourceRange(Args[0]->getLocStart(), 3558 Args[NumArgs-1]->getLocEnd())); 3559 3560 for (unsigned I = 0; I != NumArgs; ++I) 3561 Args[I]->Destroy(Context); 3562 3563 NumArgs = 0; 3564 } 3565 3566 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3567 RParenLoc)); 3568 } 3569 3570 // Determine whether this is a dependent call inside a C++ template, 3571 // in which case we won't do any semantic analysis now. 3572 // FIXME: Will need to cache the results of name lookup (including ADL) in 3573 // Fn. 3574 bool Dependent = false; 3575 if (Fn->isTypeDependent()) 3576 Dependent = true; 3577 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3578 Dependent = true; 3579 3580 if (Dependent) 3581 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3582 Context.DependentTy, RParenLoc)); 3583 3584 // Determine whether this is a call to an object (C++ [over.call.object]). 3585 if (Fn->getType()->isRecordType()) 3586 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3587 CommaLocs, RParenLoc)); 3588 3589 Expr *NakedFn = Fn->IgnoreParens(); 3590 3591 // Determine whether this is a call to an unresolved member function. 3592 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3593 // If lookup was unresolved but not dependent (i.e. didn't find 3594 // an unresolved using declaration), it has to be an overloaded 3595 // function set, which means it must contain either multiple 3596 // declarations (all methods or method templates) or a single 3597 // method template. 3598 assert((MemE->getNumDecls() > 1) || 3599 isa<FunctionTemplateDecl>(*MemE->decls_begin())); 3600 (void)MemE; 3601 3602 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3603 CommaLocs, RParenLoc); 3604 } 3605 3606 // Determine whether this is a call to a member function. 3607 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3608 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3609 if (isa<CXXMethodDecl>(MemDecl)) 3610 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3611 CommaLocs, RParenLoc); 3612 } 3613 3614 // Determine whether this is a call to a pointer-to-member function. 3615 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3616 if (BO->getOpcode() == BinaryOperator::PtrMemD || 3617 BO->getOpcode() == BinaryOperator::PtrMemI) { 3618 if (const FunctionProtoType *FPT = 3619 dyn_cast<FunctionProtoType>(BO->getType())) { 3620 QualType ResultTy = FPT->getResultType().getNonReferenceType(); 3621 3622 ExprOwningPtr<CXXMemberCallExpr> 3623 TheCall(this, new (Context) CXXMemberCallExpr(Context, BO, Args, 3624 NumArgs, ResultTy, 3625 RParenLoc)); 3626 3627 if (CheckCallReturnType(FPT->getResultType(), 3628 BO->getRHS()->getSourceRange().getBegin(), 3629 TheCall.get(), 0)) 3630 return ExprError(); 3631 3632 if (ConvertArgumentsForCall(&*TheCall, BO, 0, FPT, Args, NumArgs, 3633 RParenLoc)) 3634 return ExprError(); 3635 3636 return Owned(MaybeBindToTemporary(TheCall.release()).release()); 3637 } 3638 return ExprError(Diag(Fn->getLocStart(), 3639 diag::err_typecheck_call_not_function) 3640 << Fn->getType() << Fn->getSourceRange()); 3641 } 3642 } 3643 } 3644 3645 // If we're directly calling a function, get the appropriate declaration. 3646 // Also, in C++, keep track of whether we should perform argument-dependent 3647 // lookup and whether there were any explicitly-specified template arguments. 3648 3649 Expr *NakedFn = Fn->IgnoreParens(); 3650 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3651 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3652 return BuildOverloadedCallExpr(Fn, ULE, LParenLoc, Args, NumArgs, 3653 CommaLocs, RParenLoc); 3654 } 3655 3656 NamedDecl *NDecl = 0; 3657 if (isa<DeclRefExpr>(NakedFn)) 3658 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3659 3660 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3661} 3662 3663/// BuildResolvedCallExpr - Build a call to a resolved expression, 3664/// i.e. an expression not of \p OverloadTy. The expression should 3665/// unary-convert to an expression of function-pointer or 3666/// block-pointer type. 3667/// 3668/// \param NDecl the declaration being called, if available 3669Sema::OwningExprResult 3670Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3671 SourceLocation LParenLoc, 3672 Expr **Args, unsigned NumArgs, 3673 SourceLocation RParenLoc) { 3674 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3675 3676 // Promote the function operand. 3677 UsualUnaryConversions(Fn); 3678 3679 // Make the call expr early, before semantic checks. This guarantees cleanup 3680 // of arguments and function on error. 3681 ExprOwningPtr<CallExpr> TheCall(this, new (Context) CallExpr(Context, Fn, 3682 Args, NumArgs, 3683 Context.BoolTy, 3684 RParenLoc)); 3685 3686 const FunctionType *FuncT; 3687 if (!Fn->getType()->isBlockPointerType()) { 3688 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3689 // have type pointer to function". 3690 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3691 if (PT == 0) 3692 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3693 << Fn->getType() << Fn->getSourceRange()); 3694 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3695 } else { // This is a block call. 3696 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3697 getAs<FunctionType>(); 3698 } 3699 if (FuncT == 0) 3700 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3701 << Fn->getType() << Fn->getSourceRange()); 3702 3703 // Check for a valid return type 3704 if (CheckCallReturnType(FuncT->getResultType(), 3705 Fn->getSourceRange().getBegin(), TheCall.get(), 3706 FDecl)) 3707 return ExprError(); 3708 3709 // We know the result type of the call, set it. 3710 TheCall->setType(FuncT->getResultType().getNonReferenceType()); 3711 3712 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3713 if (ConvertArgumentsForCall(&*TheCall, Fn, FDecl, Proto, Args, NumArgs, 3714 RParenLoc)) 3715 return ExprError(); 3716 } else { 3717 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3718 3719 if (FDecl) { 3720 // Check if we have too few/too many template arguments, based 3721 // on our knowledge of the function definition. 3722 const FunctionDecl *Def = 0; 3723 if (FDecl->getBody(Def) && NumArgs != Def->param_size()) { 3724 const FunctionProtoType *Proto = 3725 Def->getType()->getAs<FunctionProtoType>(); 3726 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3727 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3728 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3729 } 3730 } 3731 } 3732 3733 // Promote the arguments (C99 6.5.2.2p6). 3734 for (unsigned i = 0; i != NumArgs; i++) { 3735 Expr *Arg = Args[i]; 3736 DefaultArgumentPromotion(Arg); 3737 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3738 Arg->getType(), 3739 PDiag(diag::err_call_incomplete_argument) 3740 << Arg->getSourceRange())) 3741 return ExprError(); 3742 TheCall->setArg(i, Arg); 3743 } 3744 } 3745 3746 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3747 if (!Method->isStatic()) 3748 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3749 << Fn->getSourceRange()); 3750 3751 // Check for sentinels 3752 if (NDecl) 3753 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3754 3755 // Do special checking on direct calls to functions. 3756 if (FDecl) { 3757 if (CheckFunctionCall(FDecl, TheCall.get())) 3758 return ExprError(); 3759 3760 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3761 return CheckBuiltinFunctionCall(BuiltinID, TheCall.take()); 3762 } else if (NDecl) { 3763 if (CheckBlockCall(NDecl, TheCall.get())) 3764 return ExprError(); 3765 } 3766 3767 return MaybeBindToTemporary(TheCall.take()); 3768} 3769 3770Action::OwningExprResult 3771Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, TypeTy *Ty, 3772 SourceLocation RParenLoc, ExprArg InitExpr) { 3773 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3774 // FIXME: put back this assert when initializers are worked out. 3775 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3776 3777 TypeSourceInfo *TInfo; 3778 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3779 if (!TInfo) 3780 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3781 3782 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, move(InitExpr)); 3783} 3784 3785Action::OwningExprResult 3786Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3787 SourceLocation RParenLoc, ExprArg InitExpr) { 3788 QualType literalType = TInfo->getType(); 3789 Expr *literalExpr = static_cast<Expr*>(InitExpr.get()); 3790 3791 if (literalType->isArrayType()) { 3792 if (literalType->isVariableArrayType()) 3793 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3794 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3795 } else if (!literalType->isDependentType() && 3796 RequireCompleteType(LParenLoc, literalType, 3797 PDiag(diag::err_typecheck_decl_incomplete_type) 3798 << SourceRange(LParenLoc, 3799 literalExpr->getSourceRange().getEnd()))) 3800 return ExprError(); 3801 3802 InitializedEntity Entity 3803 = InitializedEntity::InitializeTemporary(literalType); 3804 InitializationKind Kind 3805 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3806 /*IsCStyleCast=*/true); 3807 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3808 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3809 MultiExprArg(*this, (void**)&literalExpr, 1), 3810 &literalType); 3811 if (Result.isInvalid()) 3812 return ExprError(); 3813 InitExpr.release(); 3814 literalExpr = static_cast<Expr*>(Result.get()); 3815 3816 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3817 if (isFileScope) { // 6.5.2.5p3 3818 if (CheckForConstantInitializer(literalExpr, literalType)) 3819 return ExprError(); 3820 } 3821 3822 Result.release(); 3823 3824 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3825 literalExpr, isFileScope)); 3826} 3827 3828Action::OwningExprResult 3829Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3830 SourceLocation RBraceLoc) { 3831 unsigned NumInit = initlist.size(); 3832 Expr **InitList = reinterpret_cast<Expr**>(initlist.release()); 3833 3834 // Semantic analysis for initializers is done by ActOnDeclarator() and 3835 // CheckInitializer() - it requires knowledge of the object being intialized. 3836 3837 InitListExpr *E = new (Context) InitListExpr(LBraceLoc, InitList, NumInit, 3838 RBraceLoc); 3839 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3840 return Owned(E); 3841} 3842 3843static CastExpr::CastKind getScalarCastKind(ASTContext &Context, 3844 QualType SrcTy, QualType DestTy) { 3845 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3846 return CastExpr::CK_NoOp; 3847 3848 if (SrcTy->hasPointerRepresentation()) { 3849 if (DestTy->hasPointerRepresentation()) 3850 return DestTy->isObjCObjectPointerType() ? 3851 CastExpr::CK_AnyPointerToObjCPointerCast : 3852 CastExpr::CK_BitCast; 3853 if (DestTy->isIntegerType()) 3854 return CastExpr::CK_PointerToIntegral; 3855 } 3856 3857 if (SrcTy->isIntegerType()) { 3858 if (DestTy->isIntegerType()) 3859 return CastExpr::CK_IntegralCast; 3860 if (DestTy->hasPointerRepresentation()) 3861 return CastExpr::CK_IntegralToPointer; 3862 if (DestTy->isRealFloatingType()) 3863 return CastExpr::CK_IntegralToFloating; 3864 } 3865 3866 if (SrcTy->isRealFloatingType()) { 3867 if (DestTy->isRealFloatingType()) 3868 return CastExpr::CK_FloatingCast; 3869 if (DestTy->isIntegerType()) 3870 return CastExpr::CK_FloatingToIntegral; 3871 } 3872 3873 // FIXME: Assert here. 3874 // assert(false && "Unhandled cast combination!"); 3875 return CastExpr::CK_Unknown; 3876} 3877 3878/// CheckCastTypes - Check type constraints for casting between types. 3879bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3880 CastExpr::CastKind& Kind, 3881 CXXMethodDecl *& ConversionDecl, 3882 bool FunctionalStyle) { 3883 if (getLangOptions().CPlusPlus) 3884 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, FunctionalStyle, 3885 ConversionDecl); 3886 3887 DefaultFunctionArrayLvalueConversion(castExpr); 3888 3889 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3890 // type needs to be scalar. 3891 if (castType->isVoidType()) { 3892 // Cast to void allows any expr type. 3893 Kind = CastExpr::CK_ToVoid; 3894 return false; 3895 } 3896 3897 if (!castType->isScalarType() && !castType->isVectorType()) { 3898 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3899 (castType->isStructureType() || castType->isUnionType())) { 3900 // GCC struct/union extension: allow cast to self. 3901 // FIXME: Check that the cast destination type is complete. 3902 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3903 << castType << castExpr->getSourceRange(); 3904 Kind = CastExpr::CK_NoOp; 3905 return false; 3906 } 3907 3908 if (castType->isUnionType()) { 3909 // GCC cast to union extension 3910 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3911 RecordDecl::field_iterator Field, FieldEnd; 3912 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3913 Field != FieldEnd; ++Field) { 3914 if (Context.hasSameUnqualifiedType(Field->getType(), 3915 castExpr->getType())) { 3916 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3917 << castExpr->getSourceRange(); 3918 break; 3919 } 3920 } 3921 if (Field == FieldEnd) 3922 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3923 << castExpr->getType() << castExpr->getSourceRange(); 3924 Kind = CastExpr::CK_ToUnion; 3925 return false; 3926 } 3927 3928 // Reject any other conversions to non-scalar types. 3929 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3930 << castType << castExpr->getSourceRange(); 3931 } 3932 3933 if (!castExpr->getType()->isScalarType() && 3934 !castExpr->getType()->isVectorType()) { 3935 return Diag(castExpr->getLocStart(), 3936 diag::err_typecheck_expect_scalar_operand) 3937 << castExpr->getType() << castExpr->getSourceRange(); 3938 } 3939 3940 if (castType->isExtVectorType()) 3941 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3942 3943 if (castType->isVectorType()) 3944 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 3945 if (castExpr->getType()->isVectorType()) 3946 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 3947 3948 if (getLangOptions().ObjC1 && isa<ObjCSuperExpr>(castExpr)) 3949 return Diag(castExpr->getLocStart(), diag::err_illegal_super_cast) << TyR; 3950 3951 if (isa<ObjCSelectorExpr>(castExpr)) 3952 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 3953 3954 if (!castType->isArithmeticType()) { 3955 QualType castExprType = castExpr->getType(); 3956 if (!castExprType->isIntegralType() && castExprType->isArithmeticType()) 3957 return Diag(castExpr->getLocStart(), 3958 diag::err_cast_pointer_from_non_pointer_int) 3959 << castExprType << castExpr->getSourceRange(); 3960 } else if (!castExpr->getType()->isArithmeticType()) { 3961 if (!castType->isIntegralType() && castType->isArithmeticType()) 3962 return Diag(castExpr->getLocStart(), 3963 diag::err_cast_pointer_to_non_pointer_int) 3964 << castType << castExpr->getSourceRange(); 3965 } 3966 3967 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 3968 return false; 3969} 3970 3971bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 3972 CastExpr::CastKind &Kind) { 3973 assert(VectorTy->isVectorType() && "Not a vector type!"); 3974 3975 if (Ty->isVectorType() || Ty->isIntegerType()) { 3976 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 3977 return Diag(R.getBegin(), 3978 Ty->isVectorType() ? 3979 diag::err_invalid_conversion_between_vectors : 3980 diag::err_invalid_conversion_between_vector_and_integer) 3981 << VectorTy << Ty << R; 3982 } else 3983 return Diag(R.getBegin(), 3984 diag::err_invalid_conversion_between_vector_and_scalar) 3985 << VectorTy << Ty << R; 3986 3987 Kind = CastExpr::CK_BitCast; 3988 return false; 3989} 3990 3991bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 3992 CastExpr::CastKind &Kind) { 3993 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 3994 3995 QualType SrcTy = CastExpr->getType(); 3996 3997 // If SrcTy is a VectorType, the total size must match to explicitly cast to 3998 // an ExtVectorType. 3999 if (SrcTy->isVectorType()) { 4000 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4001 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4002 << DestTy << SrcTy << R; 4003 Kind = CastExpr::CK_BitCast; 4004 return false; 4005 } 4006 4007 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4008 // conversion will take place first from scalar to elt type, and then 4009 // splat from elt type to vector. 4010 if (SrcTy->isPointerType()) 4011 return Diag(R.getBegin(), 4012 diag::err_invalid_conversion_between_vector_and_scalar) 4013 << DestTy << SrcTy << R; 4014 4015 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4016 ImpCastExprToType(CastExpr, DestElemTy, 4017 getScalarCastKind(Context, SrcTy, DestElemTy)); 4018 4019 Kind = CastExpr::CK_VectorSplat; 4020 return false; 4021} 4022 4023Action::OwningExprResult 4024Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, TypeTy *Ty, 4025 SourceLocation RParenLoc, ExprArg Op) { 4026 assert((Ty != 0) && (Op.get() != 0) && 4027 "ActOnCastExpr(): missing type or expr"); 4028 4029 TypeSourceInfo *castTInfo; 4030 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4031 if (!castTInfo) 4032 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4033 4034 // If the Expr being casted is a ParenListExpr, handle it specially. 4035 Expr *castExpr = (Expr *)Op.get(); 4036 if (isa<ParenListExpr>(castExpr)) 4037 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, move(Op), 4038 castTInfo); 4039 4040 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, move(Op)); 4041} 4042 4043Action::OwningExprResult 4044Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4045 SourceLocation RParenLoc, ExprArg Op) { 4046 Expr *castExpr = static_cast<Expr*>(Op.get()); 4047 4048 CXXMethodDecl *Method = 0; 4049 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 4050 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4051 Kind, Method)) 4052 return ExprError(); 4053 4054 if (Method) { 4055 // FIXME: preserve type source info here 4056 OwningExprResult CastArg = BuildCXXCastArgument(LParenLoc, Ty->getType(), 4057 Kind, Method, move(Op)); 4058 4059 if (CastArg.isInvalid()) 4060 return ExprError(); 4061 4062 castExpr = CastArg.takeAs<Expr>(); 4063 } else { 4064 Op.release(); 4065 } 4066 4067 return Owned(new (Context) CStyleCastExpr(Ty->getType().getNonReferenceType(), 4068 Kind, castExpr, Ty, 4069 LParenLoc, RParenLoc)); 4070} 4071 4072/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4073/// of comma binary operators. 4074Action::OwningExprResult 4075Sema::MaybeConvertParenListExprToParenExpr(Scope *S, ExprArg EA) { 4076 Expr *expr = EA.takeAs<Expr>(); 4077 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4078 if (!E) 4079 return Owned(expr); 4080 4081 OwningExprResult Result(*this, E->getExpr(0)); 4082 4083 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4084 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, move(Result), 4085 Owned(E->getExpr(i))); 4086 4087 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), move(Result)); 4088} 4089 4090Action::OwningExprResult 4091Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4092 SourceLocation RParenLoc, ExprArg Op, 4093 TypeSourceInfo *TInfo) { 4094 ParenListExpr *PE = (ParenListExpr *)Op.get(); 4095 QualType Ty = TInfo->getType(); 4096 4097 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4098 // then handle it as such. 4099 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4100 if (PE->getNumExprs() == 0) { 4101 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4102 return ExprError(); 4103 } 4104 4105 llvm::SmallVector<Expr *, 8> initExprs; 4106 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4107 initExprs.push_back(PE->getExpr(i)); 4108 4109 // FIXME: This means that pretty-printing the final AST will produce curly 4110 // braces instead of the original commas. 4111 Op.release(); 4112 InitListExpr *E = new (Context) InitListExpr(LParenLoc, &initExprs[0], 4113 initExprs.size(), RParenLoc); 4114 E->setType(Ty); 4115 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, Owned(E)); 4116 } else { 4117 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4118 // sequence of BinOp comma operators. 4119 Op = MaybeConvertParenListExprToParenExpr(S, move(Op)); 4120 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, move(Op)); 4121 } 4122} 4123 4124Action::OwningExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4125 SourceLocation R, 4126 MultiExprArg Val, 4127 TypeTy *TypeOfCast) { 4128 unsigned nexprs = Val.size(); 4129 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4130 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4131 Expr *expr; 4132 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4133 expr = new (Context) ParenExpr(L, R, exprs[0]); 4134 else 4135 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4136 return Owned(expr); 4137} 4138 4139/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4140/// In that case, lhs = cond. 4141/// C99 6.5.15 4142QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4143 SourceLocation QuestionLoc) { 4144 // C++ is sufficiently different to merit its own checker. 4145 if (getLangOptions().CPlusPlus) 4146 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4147 4148 CheckSignCompare(LHS, RHS, QuestionLoc); 4149 4150 UsualUnaryConversions(Cond); 4151 UsualUnaryConversions(LHS); 4152 UsualUnaryConversions(RHS); 4153 QualType CondTy = Cond->getType(); 4154 QualType LHSTy = LHS->getType(); 4155 QualType RHSTy = RHS->getType(); 4156 4157 // first, check the condition. 4158 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4159 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4160 << CondTy; 4161 return QualType(); 4162 } 4163 4164 // Now check the two expressions. 4165 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4166 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4167 4168 // If both operands have arithmetic type, do the usual arithmetic conversions 4169 // to find a common type: C99 6.5.15p3,5. 4170 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4171 UsualArithmeticConversions(LHS, RHS); 4172 return LHS->getType(); 4173 } 4174 4175 // If both operands are the same structure or union type, the result is that 4176 // type. 4177 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4178 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4179 if (LHSRT->getDecl() == RHSRT->getDecl()) 4180 // "If both the operands have structure or union type, the result has 4181 // that type." This implies that CV qualifiers are dropped. 4182 return LHSTy.getUnqualifiedType(); 4183 // FIXME: Type of conditional expression must be complete in C mode. 4184 } 4185 4186 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4187 // The following || allows only one side to be void (a GCC-ism). 4188 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4189 if (!LHSTy->isVoidType()) 4190 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4191 << RHS->getSourceRange(); 4192 if (!RHSTy->isVoidType()) 4193 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4194 << LHS->getSourceRange(); 4195 ImpCastExprToType(LHS, Context.VoidTy, CastExpr::CK_ToVoid); 4196 ImpCastExprToType(RHS, Context.VoidTy, CastExpr::CK_ToVoid); 4197 return Context.VoidTy; 4198 } 4199 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4200 // the type of the other operand." 4201 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4202 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4203 // promote the null to a pointer. 4204 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_Unknown); 4205 return LHSTy; 4206 } 4207 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4208 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4209 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_Unknown); 4210 return RHSTy; 4211 } 4212 4213 // All objective-c pointer type analysis is done here. 4214 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4215 QuestionLoc); 4216 if (!compositeType.isNull()) 4217 return compositeType; 4218 4219 4220 // Handle block pointer types. 4221 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4222 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4223 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4224 QualType destType = Context.getPointerType(Context.VoidTy); 4225 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4226 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4227 return destType; 4228 } 4229 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4230 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4231 return QualType(); 4232 } 4233 // We have 2 block pointer types. 4234 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4235 // Two identical block pointer types are always compatible. 4236 return LHSTy; 4237 } 4238 // The block pointer types aren't identical, continue checking. 4239 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4240 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4241 4242 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4243 rhptee.getUnqualifiedType())) { 4244 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4245 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4246 // In this situation, we assume void* type. No especially good 4247 // reason, but this is what gcc does, and we do have to pick 4248 // to get a consistent AST. 4249 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4250 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4251 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4252 return incompatTy; 4253 } 4254 // The block pointer types are compatible. 4255 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4256 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4257 return LHSTy; 4258 } 4259 4260 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4261 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4262 // get the "pointed to" types 4263 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4264 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4265 4266 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4267 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4268 // Figure out necessary qualifiers (C99 6.5.15p6) 4269 QualType destPointee 4270 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4271 QualType destType = Context.getPointerType(destPointee); 4272 // Add qualifiers if necessary. 4273 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4274 // Promote to void*. 4275 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4276 return destType; 4277 } 4278 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4279 QualType destPointee 4280 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4281 QualType destType = Context.getPointerType(destPointee); 4282 // Add qualifiers if necessary. 4283 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4284 // Promote to void*. 4285 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4286 return destType; 4287 } 4288 4289 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4290 // Two identical pointer types are always compatible. 4291 return LHSTy; 4292 } 4293 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4294 rhptee.getUnqualifiedType())) { 4295 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4296 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4297 // In this situation, we assume void* type. No especially good 4298 // reason, but this is what gcc does, and we do have to pick 4299 // to get a consistent AST. 4300 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4301 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4302 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4303 return incompatTy; 4304 } 4305 // The pointer types are compatible. 4306 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4307 // differently qualified versions of compatible types, the result type is 4308 // a pointer to an appropriately qualified version of the *composite* 4309 // type. 4310 // FIXME: Need to calculate the composite type. 4311 // FIXME: Need to add qualifiers 4312 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4313 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4314 return LHSTy; 4315 } 4316 4317 // GCC compatibility: soften pointer/integer mismatch. 4318 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4319 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4320 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4321 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_IntegralToPointer); 4322 return RHSTy; 4323 } 4324 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4325 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4326 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4327 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_IntegralToPointer); 4328 return LHSTy; 4329 } 4330 4331 // Otherwise, the operands are not compatible. 4332 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4333 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4334 return QualType(); 4335} 4336 4337/// FindCompositeObjCPointerType - Helper method to find composite type of 4338/// two objective-c pointer types of the two input expressions. 4339QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4340 SourceLocation QuestionLoc) { 4341 QualType LHSTy = LHS->getType(); 4342 QualType RHSTy = RHS->getType(); 4343 4344 // Handle things like Class and struct objc_class*. Here we case the result 4345 // to the pseudo-builtin, because that will be implicitly cast back to the 4346 // redefinition type if an attempt is made to access its fields. 4347 if (LHSTy->isObjCClassType() && 4348 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4349 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4350 return LHSTy; 4351 } 4352 if (RHSTy->isObjCClassType() && 4353 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4354 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4355 return RHSTy; 4356 } 4357 // And the same for struct objc_object* / id 4358 if (LHSTy->isObjCIdType() && 4359 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4360 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4361 return LHSTy; 4362 } 4363 if (RHSTy->isObjCIdType() && 4364 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4365 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4366 return RHSTy; 4367 } 4368 // And the same for struct objc_selector* / SEL 4369 if (Context.isObjCSelType(LHSTy) && 4370 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4371 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4372 return LHSTy; 4373 } 4374 if (Context.isObjCSelType(RHSTy) && 4375 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4376 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4377 return RHSTy; 4378 } 4379 // Check constraints for Objective-C object pointers types. 4380 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4381 4382 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4383 // Two identical object pointer types are always compatible. 4384 return LHSTy; 4385 } 4386 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4387 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4388 QualType compositeType = LHSTy; 4389 4390 // If both operands are interfaces and either operand can be 4391 // assigned to the other, use that type as the composite 4392 // type. This allows 4393 // xxx ? (A*) a : (B*) b 4394 // where B is a subclass of A. 4395 // 4396 // Additionally, as for assignment, if either type is 'id' 4397 // allow silent coercion. Finally, if the types are 4398 // incompatible then make sure to use 'id' as the composite 4399 // type so the result is acceptable for sending messages to. 4400 4401 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4402 // It could return the composite type. 4403 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4404 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4405 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4406 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4407 } else if ((LHSTy->isObjCQualifiedIdType() || 4408 RHSTy->isObjCQualifiedIdType()) && 4409 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4410 // Need to handle "id<xx>" explicitly. 4411 // GCC allows qualified id and any Objective-C type to devolve to 4412 // id. Currently localizing to here until clear this should be 4413 // part of ObjCQualifiedIdTypesAreCompatible. 4414 compositeType = Context.getObjCIdType(); 4415 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4416 compositeType = Context.getObjCIdType(); 4417 } else if (!(compositeType = 4418 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4419 ; 4420 else { 4421 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4422 << LHSTy << RHSTy 4423 << LHS->getSourceRange() << RHS->getSourceRange(); 4424 QualType incompatTy = Context.getObjCIdType(); 4425 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4426 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4427 return incompatTy; 4428 } 4429 // The object pointer types are compatible. 4430 ImpCastExprToType(LHS, compositeType, CastExpr::CK_BitCast); 4431 ImpCastExprToType(RHS, compositeType, CastExpr::CK_BitCast); 4432 return compositeType; 4433 } 4434 // Check Objective-C object pointer types and 'void *' 4435 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4436 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4437 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4438 QualType destPointee 4439 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4440 QualType destType = Context.getPointerType(destPointee); 4441 // Add qualifiers if necessary. 4442 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4443 // Promote to void*. 4444 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4445 return destType; 4446 } 4447 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4448 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4449 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4450 QualType destPointee 4451 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4452 QualType destType = Context.getPointerType(destPointee); 4453 // Add qualifiers if necessary. 4454 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4455 // Promote to void*. 4456 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4457 return destType; 4458 } 4459 return QualType(); 4460} 4461 4462/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4463/// in the case of a the GNU conditional expr extension. 4464Action::OwningExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4465 SourceLocation ColonLoc, 4466 ExprArg Cond, ExprArg LHS, 4467 ExprArg RHS) { 4468 Expr *CondExpr = (Expr *) Cond.get(); 4469 Expr *LHSExpr = (Expr *) LHS.get(), *RHSExpr = (Expr *) RHS.get(); 4470 4471 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4472 // was the condition. 4473 bool isLHSNull = LHSExpr == 0; 4474 if (isLHSNull) 4475 LHSExpr = CondExpr; 4476 4477 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4478 RHSExpr, QuestionLoc); 4479 if (result.isNull()) 4480 return ExprError(); 4481 4482 Cond.release(); 4483 LHS.release(); 4484 RHS.release(); 4485 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4486 isLHSNull ? 0 : LHSExpr, 4487 ColonLoc, RHSExpr, result)); 4488} 4489 4490// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4491// being closely modeled after the C99 spec:-). The odd characteristic of this 4492// routine is it effectively iqnores the qualifiers on the top level pointee. 4493// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4494// FIXME: add a couple examples in this comment. 4495Sema::AssignConvertType 4496Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4497 QualType lhptee, rhptee; 4498 4499 if ((lhsType->isObjCClassType() && 4500 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4501 (rhsType->isObjCClassType() && 4502 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4503 return Compatible; 4504 } 4505 4506 // get the "pointed to" type (ignoring qualifiers at the top level) 4507 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4508 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4509 4510 // make sure we operate on the canonical type 4511 lhptee = Context.getCanonicalType(lhptee); 4512 rhptee = Context.getCanonicalType(rhptee); 4513 4514 AssignConvertType ConvTy = Compatible; 4515 4516 // C99 6.5.16.1p1: This following citation is common to constraints 4517 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4518 // qualifiers of the type *pointed to* by the right; 4519 // FIXME: Handle ExtQualType 4520 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4521 ConvTy = CompatiblePointerDiscardsQualifiers; 4522 4523 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4524 // incomplete type and the other is a pointer to a qualified or unqualified 4525 // version of void... 4526 if (lhptee->isVoidType()) { 4527 if (rhptee->isIncompleteOrObjectType()) 4528 return ConvTy; 4529 4530 // As an extension, we allow cast to/from void* to function pointer. 4531 assert(rhptee->isFunctionType()); 4532 return FunctionVoidPointer; 4533 } 4534 4535 if (rhptee->isVoidType()) { 4536 if (lhptee->isIncompleteOrObjectType()) 4537 return ConvTy; 4538 4539 // As an extension, we allow cast to/from void* to function pointer. 4540 assert(lhptee->isFunctionType()); 4541 return FunctionVoidPointer; 4542 } 4543 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4544 // unqualified versions of compatible types, ... 4545 lhptee = lhptee.getUnqualifiedType(); 4546 rhptee = rhptee.getUnqualifiedType(); 4547 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4548 // Check if the pointee types are compatible ignoring the sign. 4549 // We explicitly check for char so that we catch "char" vs 4550 // "unsigned char" on systems where "char" is unsigned. 4551 if (lhptee->isCharType()) 4552 lhptee = Context.UnsignedCharTy; 4553 else if (lhptee->isSignedIntegerType()) 4554 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4555 4556 if (rhptee->isCharType()) 4557 rhptee = Context.UnsignedCharTy; 4558 else if (rhptee->isSignedIntegerType()) 4559 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4560 4561 if (lhptee == rhptee) { 4562 // Types are compatible ignoring the sign. Qualifier incompatibility 4563 // takes priority over sign incompatibility because the sign 4564 // warning can be disabled. 4565 if (ConvTy != Compatible) 4566 return ConvTy; 4567 return IncompatiblePointerSign; 4568 } 4569 4570 // If we are a multi-level pointer, it's possible that our issue is simply 4571 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4572 // the eventual target type is the same and the pointers have the same 4573 // level of indirection, this must be the issue. 4574 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4575 do { 4576 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4577 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4578 4579 lhptee = Context.getCanonicalType(lhptee); 4580 rhptee = Context.getCanonicalType(rhptee); 4581 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4582 4583 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4584 return IncompatibleNestedPointerQualifiers; 4585 } 4586 4587 // General pointer incompatibility takes priority over qualifiers. 4588 return IncompatiblePointer; 4589 } 4590 return ConvTy; 4591} 4592 4593/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4594/// block pointer types are compatible or whether a block and normal pointer 4595/// are compatible. It is more restrict than comparing two function pointer 4596// types. 4597Sema::AssignConvertType 4598Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4599 QualType rhsType) { 4600 QualType lhptee, rhptee; 4601 4602 // get the "pointed to" type (ignoring qualifiers at the top level) 4603 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4604 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4605 4606 // make sure we operate on the canonical type 4607 lhptee = Context.getCanonicalType(lhptee); 4608 rhptee = Context.getCanonicalType(rhptee); 4609 4610 AssignConvertType ConvTy = Compatible; 4611 4612 // For blocks we enforce that qualifiers are identical. 4613 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4614 ConvTy = CompatiblePointerDiscardsQualifiers; 4615 4616 if (!getLangOptions().CPlusPlus) { 4617 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4618 return IncompatibleBlockPointer; 4619 } 4620 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4621 return IncompatibleBlockPointer; 4622 return ConvTy; 4623} 4624 4625/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4626/// for assignment compatibility. 4627Sema::AssignConvertType 4628Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4629 if (lhsType->isObjCBuiltinType()) { 4630 // Class is not compatible with ObjC object pointers. 4631 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4632 !rhsType->isObjCQualifiedClassType()) 4633 return IncompatiblePointer; 4634 return Compatible; 4635 } 4636 if (rhsType->isObjCBuiltinType()) { 4637 // Class is not compatible with ObjC object pointers. 4638 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4639 !lhsType->isObjCQualifiedClassType()) 4640 return IncompatiblePointer; 4641 return Compatible; 4642 } 4643 QualType lhptee = 4644 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4645 QualType rhptee = 4646 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4647 // make sure we operate on the canonical type 4648 lhptee = Context.getCanonicalType(lhptee); 4649 rhptee = Context.getCanonicalType(rhptee); 4650 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4651 return CompatiblePointerDiscardsQualifiers; 4652 4653 if (Context.typesAreCompatible(lhsType, rhsType)) 4654 return Compatible; 4655 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4656 return IncompatibleObjCQualifiedId; 4657 return IncompatiblePointer; 4658} 4659 4660/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4661/// has code to accommodate several GCC extensions when type checking 4662/// pointers. Here are some objectionable examples that GCC considers warnings: 4663/// 4664/// int a, *pint; 4665/// short *pshort; 4666/// struct foo *pfoo; 4667/// 4668/// pint = pshort; // warning: assignment from incompatible pointer type 4669/// a = pint; // warning: assignment makes integer from pointer without a cast 4670/// pint = a; // warning: assignment makes pointer from integer without a cast 4671/// pint = pfoo; // warning: assignment from incompatible pointer type 4672/// 4673/// As a result, the code for dealing with pointers is more complex than the 4674/// C99 spec dictates. 4675/// 4676Sema::AssignConvertType 4677Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4678 // Get canonical types. We're not formatting these types, just comparing 4679 // them. 4680 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4681 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4682 4683 if (lhsType == rhsType) 4684 return Compatible; // Common case: fast path an exact match. 4685 4686 if ((lhsType->isObjCClassType() && 4687 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4688 (rhsType->isObjCClassType() && 4689 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4690 return Compatible; 4691 } 4692 4693 // If the left-hand side is a reference type, then we are in a 4694 // (rare!) case where we've allowed the use of references in C, 4695 // e.g., as a parameter type in a built-in function. In this case, 4696 // just make sure that the type referenced is compatible with the 4697 // right-hand side type. The caller is responsible for adjusting 4698 // lhsType so that the resulting expression does not have reference 4699 // type. 4700 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4701 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4702 return Compatible; 4703 return Incompatible; 4704 } 4705 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4706 // to the same ExtVector type. 4707 if (lhsType->isExtVectorType()) { 4708 if (rhsType->isExtVectorType()) 4709 return lhsType == rhsType ? Compatible : Incompatible; 4710 if (!rhsType->isVectorType() && rhsType->isArithmeticType()) 4711 return Compatible; 4712 } 4713 4714 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4715 // If we are allowing lax vector conversions, and LHS and RHS are both 4716 // vectors, the total size only needs to be the same. This is a bitcast; 4717 // no bits are changed but the result type is different. 4718 if (getLangOptions().LaxVectorConversions && 4719 lhsType->isVectorType() && rhsType->isVectorType()) { 4720 if (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType)) 4721 return IncompatibleVectors; 4722 } 4723 return Incompatible; 4724 } 4725 4726 if (lhsType->isArithmeticType() && rhsType->isArithmeticType()) 4727 return Compatible; 4728 4729 if (isa<PointerType>(lhsType)) { 4730 if (rhsType->isIntegerType()) 4731 return IntToPointer; 4732 4733 if (isa<PointerType>(rhsType)) 4734 return CheckPointerTypesForAssignment(lhsType, rhsType); 4735 4736 // In general, C pointers are not compatible with ObjC object pointers. 4737 if (isa<ObjCObjectPointerType>(rhsType)) { 4738 if (lhsType->isVoidPointerType()) // an exception to the rule. 4739 return Compatible; 4740 return IncompatiblePointer; 4741 } 4742 if (rhsType->getAs<BlockPointerType>()) { 4743 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4744 return Compatible; 4745 4746 // Treat block pointers as objects. 4747 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4748 return Compatible; 4749 } 4750 return Incompatible; 4751 } 4752 4753 if (isa<BlockPointerType>(lhsType)) { 4754 if (rhsType->isIntegerType()) 4755 return IntToBlockPointer; 4756 4757 // Treat block pointers as objects. 4758 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4759 return Compatible; 4760 4761 if (rhsType->isBlockPointerType()) 4762 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4763 4764 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4765 if (RHSPT->getPointeeType()->isVoidType()) 4766 return Compatible; 4767 } 4768 return Incompatible; 4769 } 4770 4771 if (isa<ObjCObjectPointerType>(lhsType)) { 4772 if (rhsType->isIntegerType()) 4773 return IntToPointer; 4774 4775 // In general, C pointers are not compatible with ObjC object pointers. 4776 if (isa<PointerType>(rhsType)) { 4777 if (rhsType->isVoidPointerType()) // an exception to the rule. 4778 return Compatible; 4779 return IncompatiblePointer; 4780 } 4781 if (rhsType->isObjCObjectPointerType()) { 4782 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4783 } 4784 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4785 if (RHSPT->getPointeeType()->isVoidType()) 4786 return Compatible; 4787 } 4788 // Treat block pointers as objects. 4789 if (rhsType->isBlockPointerType()) 4790 return Compatible; 4791 return Incompatible; 4792 } 4793 if (isa<PointerType>(rhsType)) { 4794 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4795 if (lhsType == Context.BoolTy) 4796 return Compatible; 4797 4798 if (lhsType->isIntegerType()) 4799 return PointerToInt; 4800 4801 if (isa<PointerType>(lhsType)) 4802 return CheckPointerTypesForAssignment(lhsType, rhsType); 4803 4804 if (isa<BlockPointerType>(lhsType) && 4805 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4806 return Compatible; 4807 return Incompatible; 4808 } 4809 if (isa<ObjCObjectPointerType>(rhsType)) { 4810 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4811 if (lhsType == Context.BoolTy) 4812 return Compatible; 4813 4814 if (lhsType->isIntegerType()) 4815 return PointerToInt; 4816 4817 // In general, C pointers are not compatible with ObjC object pointers. 4818 if (isa<PointerType>(lhsType)) { 4819 if (lhsType->isVoidPointerType()) // an exception to the rule. 4820 return Compatible; 4821 return IncompatiblePointer; 4822 } 4823 if (isa<BlockPointerType>(lhsType) && 4824 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4825 return Compatible; 4826 return Incompatible; 4827 } 4828 4829 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4830 if (Context.typesAreCompatible(lhsType, rhsType)) 4831 return Compatible; 4832 } 4833 return Incompatible; 4834} 4835 4836/// \brief Constructs a transparent union from an expression that is 4837/// used to initialize the transparent union. 4838static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4839 QualType UnionType, FieldDecl *Field) { 4840 // Build an initializer list that designates the appropriate member 4841 // of the transparent union. 4842 InitListExpr *Initializer = new (C) InitListExpr(SourceLocation(), 4843 &E, 1, 4844 SourceLocation()); 4845 Initializer->setType(UnionType); 4846 Initializer->setInitializedFieldInUnion(Field); 4847 4848 // Build a compound literal constructing a value of the transparent 4849 // union type from this initializer list. 4850 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4851 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4852 Initializer, false); 4853} 4854 4855Sema::AssignConvertType 4856Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4857 QualType FromType = rExpr->getType(); 4858 4859 // If the ArgType is a Union type, we want to handle a potential 4860 // transparent_union GCC extension. 4861 const RecordType *UT = ArgType->getAsUnionType(); 4862 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4863 return Incompatible; 4864 4865 // The field to initialize within the transparent union. 4866 RecordDecl *UD = UT->getDecl(); 4867 FieldDecl *InitField = 0; 4868 // It's compatible if the expression matches any of the fields. 4869 for (RecordDecl::field_iterator it = UD->field_begin(), 4870 itend = UD->field_end(); 4871 it != itend; ++it) { 4872 if (it->getType()->isPointerType()) { 4873 // If the transparent union contains a pointer type, we allow: 4874 // 1) void pointer 4875 // 2) null pointer constant 4876 if (FromType->isPointerType()) 4877 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4878 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_BitCast); 4879 InitField = *it; 4880 break; 4881 } 4882 4883 if (rExpr->isNullPointerConstant(Context, 4884 Expr::NPC_ValueDependentIsNull)) { 4885 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_IntegralToPointer); 4886 InitField = *it; 4887 break; 4888 } 4889 } 4890 4891 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4892 == Compatible) { 4893 InitField = *it; 4894 break; 4895 } 4896 } 4897 4898 if (!InitField) 4899 return Incompatible; 4900 4901 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4902 return Compatible; 4903} 4904 4905Sema::AssignConvertType 4906Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4907 if (getLangOptions().CPlusPlus) { 4908 if (!lhsType->isRecordType()) { 4909 // C++ 5.17p3: If the left operand is not of class type, the 4910 // expression is implicitly converted (C++ 4) to the 4911 // cv-unqualified type of the left operand. 4912 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4913 AA_Assigning)) 4914 return Incompatible; 4915 return Compatible; 4916 } 4917 4918 // FIXME: Currently, we fall through and treat C++ classes like C 4919 // structures. 4920 } 4921 4922 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4923 // a null pointer constant. 4924 if ((lhsType->isPointerType() || 4925 lhsType->isObjCObjectPointerType() || 4926 lhsType->isBlockPointerType()) 4927 && rExpr->isNullPointerConstant(Context, 4928 Expr::NPC_ValueDependentIsNull)) { 4929 ImpCastExprToType(rExpr, lhsType, CastExpr::CK_Unknown); 4930 return Compatible; 4931 } 4932 4933 // This check seems unnatural, however it is necessary to ensure the proper 4934 // conversion of functions/arrays. If the conversion were done for all 4935 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4936 // expressions that surpress this implicit conversion (&, sizeof). 4937 // 4938 // Suppress this for references: C++ 8.5.3p5. 4939 if (!lhsType->isReferenceType()) 4940 DefaultFunctionArrayLvalueConversion(rExpr); 4941 4942 Sema::AssignConvertType result = 4943 CheckAssignmentConstraints(lhsType, rExpr->getType()); 4944 4945 // C99 6.5.16.1p2: The value of the right operand is converted to the 4946 // type of the assignment expression. 4947 // CheckAssignmentConstraints allows the left-hand side to be a reference, 4948 // so that we can use references in built-in functions even in C. 4949 // The getNonReferenceType() call makes sure that the resulting expression 4950 // does not have reference type. 4951 if (result != Incompatible && rExpr->getType() != lhsType) 4952 ImpCastExprToType(rExpr, lhsType.getNonReferenceType(), 4953 CastExpr::CK_Unknown); 4954 return result; 4955} 4956 4957QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4958 Diag(Loc, diag::err_typecheck_invalid_operands) 4959 << lex->getType() << rex->getType() 4960 << lex->getSourceRange() << rex->getSourceRange(); 4961 return QualType(); 4962} 4963 4964QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4965 // For conversion purposes, we ignore any qualifiers. 4966 // For example, "const float" and "float" are equivalent. 4967 QualType lhsType = 4968 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 4969 QualType rhsType = 4970 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 4971 4972 // If the vector types are identical, return. 4973 if (lhsType == rhsType) 4974 return lhsType; 4975 4976 // Handle the case of a vector & extvector type of the same size and element 4977 // type. It would be nice if we only had one vector type someday. 4978 if (getLangOptions().LaxVectorConversions) { 4979 // FIXME: Should we warn here? 4980 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 4981 if (const VectorType *RV = rhsType->getAs<VectorType>()) 4982 if (LV->getElementType() == RV->getElementType() && 4983 LV->getNumElements() == RV->getNumElements()) { 4984 return lhsType->isExtVectorType() ? lhsType : rhsType; 4985 } 4986 } 4987 } 4988 4989 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 4990 // swap back (so that we don't reverse the inputs to a subtract, for instance. 4991 bool swapped = false; 4992 if (rhsType->isExtVectorType()) { 4993 swapped = true; 4994 std::swap(rex, lex); 4995 std::swap(rhsType, lhsType); 4996 } 4997 4998 // Handle the case of an ext vector and scalar. 4999 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5000 QualType EltTy = LV->getElementType(); 5001 if (EltTy->isIntegralType() && rhsType->isIntegralType()) { 5002 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5003 ImpCastExprToType(rex, lhsType, CastExpr::CK_IntegralCast); 5004 if (swapped) std::swap(rex, lex); 5005 return lhsType; 5006 } 5007 } 5008 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5009 rhsType->isRealFloatingType()) { 5010 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5011 ImpCastExprToType(rex, lhsType, CastExpr::CK_FloatingCast); 5012 if (swapped) std::swap(rex, lex); 5013 return lhsType; 5014 } 5015 } 5016 } 5017 5018 // Vectors of different size or scalar and non-ext-vector are errors. 5019 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5020 << lex->getType() << rex->getType() 5021 << lex->getSourceRange() << rex->getSourceRange(); 5022 return QualType(); 5023} 5024 5025QualType Sema::CheckMultiplyDivideOperands( 5026 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5027 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5028 return CheckVectorOperands(Loc, lex, rex); 5029 5030 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5031 5032 if (!lex->getType()->isArithmeticType() || 5033 !rex->getType()->isArithmeticType()) 5034 return InvalidOperands(Loc, lex, rex); 5035 5036 // Check for division by zero. 5037 if (isDiv && 5038 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5039 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5040 << rex->getSourceRange()); 5041 5042 return compType; 5043} 5044 5045QualType Sema::CheckRemainderOperands( 5046 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5047 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5048 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5049 return CheckVectorOperands(Loc, lex, rex); 5050 return InvalidOperands(Loc, lex, rex); 5051 } 5052 5053 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5054 5055 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5056 return InvalidOperands(Loc, lex, rex); 5057 5058 // Check for remainder by zero. 5059 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5060 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5061 << rex->getSourceRange()); 5062 5063 return compType; 5064} 5065 5066QualType Sema::CheckAdditionOperands( // C99 6.5.6 5067 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5068 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5069 QualType compType = CheckVectorOperands(Loc, lex, rex); 5070 if (CompLHSTy) *CompLHSTy = compType; 5071 return compType; 5072 } 5073 5074 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5075 5076 // handle the common case first (both operands are arithmetic). 5077 if (lex->getType()->isArithmeticType() && 5078 rex->getType()->isArithmeticType()) { 5079 if (CompLHSTy) *CompLHSTy = compType; 5080 return compType; 5081 } 5082 5083 // Put any potential pointer into PExp 5084 Expr* PExp = lex, *IExp = rex; 5085 if (IExp->getType()->isAnyPointerType()) 5086 std::swap(PExp, IExp); 5087 5088 if (PExp->getType()->isAnyPointerType()) { 5089 5090 if (IExp->getType()->isIntegerType()) { 5091 QualType PointeeTy = PExp->getType()->getPointeeType(); 5092 5093 // Check for arithmetic on pointers to incomplete types. 5094 if (PointeeTy->isVoidType()) { 5095 if (getLangOptions().CPlusPlus) { 5096 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5097 << lex->getSourceRange() << rex->getSourceRange(); 5098 return QualType(); 5099 } 5100 5101 // GNU extension: arithmetic on pointer to void 5102 Diag(Loc, diag::ext_gnu_void_ptr) 5103 << lex->getSourceRange() << rex->getSourceRange(); 5104 } else if (PointeeTy->isFunctionType()) { 5105 if (getLangOptions().CPlusPlus) { 5106 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5107 << lex->getType() << lex->getSourceRange(); 5108 return QualType(); 5109 } 5110 5111 // GNU extension: arithmetic on pointer to function 5112 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5113 << lex->getType() << lex->getSourceRange(); 5114 } else { 5115 // Check if we require a complete type. 5116 if (((PExp->getType()->isPointerType() && 5117 !PExp->getType()->isDependentType()) || 5118 PExp->getType()->isObjCObjectPointerType()) && 5119 RequireCompleteType(Loc, PointeeTy, 5120 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5121 << PExp->getSourceRange() 5122 << PExp->getType())) 5123 return QualType(); 5124 } 5125 // Diagnose bad cases where we step over interface counts. 5126 if (PointeeTy->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 5127 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5128 << PointeeTy << PExp->getSourceRange(); 5129 return QualType(); 5130 } 5131 5132 if (CompLHSTy) { 5133 QualType LHSTy = Context.isPromotableBitField(lex); 5134 if (LHSTy.isNull()) { 5135 LHSTy = lex->getType(); 5136 if (LHSTy->isPromotableIntegerType()) 5137 LHSTy = Context.getPromotedIntegerType(LHSTy); 5138 } 5139 *CompLHSTy = LHSTy; 5140 } 5141 return PExp->getType(); 5142 } 5143 } 5144 5145 return InvalidOperands(Loc, lex, rex); 5146} 5147 5148// C99 6.5.6 5149QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5150 SourceLocation Loc, QualType* CompLHSTy) { 5151 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5152 QualType compType = CheckVectorOperands(Loc, lex, rex); 5153 if (CompLHSTy) *CompLHSTy = compType; 5154 return compType; 5155 } 5156 5157 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5158 5159 // Enforce type constraints: C99 6.5.6p3. 5160 5161 // Handle the common case first (both operands are arithmetic). 5162 if (lex->getType()->isArithmeticType() 5163 && rex->getType()->isArithmeticType()) { 5164 if (CompLHSTy) *CompLHSTy = compType; 5165 return compType; 5166 } 5167 5168 // Either ptr - int or ptr - ptr. 5169 if (lex->getType()->isAnyPointerType()) { 5170 QualType lpointee = lex->getType()->getPointeeType(); 5171 5172 // The LHS must be an completely-defined object type. 5173 5174 bool ComplainAboutVoid = false; 5175 Expr *ComplainAboutFunc = 0; 5176 if (lpointee->isVoidType()) { 5177 if (getLangOptions().CPlusPlus) { 5178 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5179 << lex->getSourceRange() << rex->getSourceRange(); 5180 return QualType(); 5181 } 5182 5183 // GNU C extension: arithmetic on pointer to void 5184 ComplainAboutVoid = true; 5185 } else if (lpointee->isFunctionType()) { 5186 if (getLangOptions().CPlusPlus) { 5187 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5188 << lex->getType() << lex->getSourceRange(); 5189 return QualType(); 5190 } 5191 5192 // GNU C extension: arithmetic on pointer to function 5193 ComplainAboutFunc = lex; 5194 } else if (!lpointee->isDependentType() && 5195 RequireCompleteType(Loc, lpointee, 5196 PDiag(diag::err_typecheck_sub_ptr_object) 5197 << lex->getSourceRange() 5198 << lex->getType())) 5199 return QualType(); 5200 5201 // Diagnose bad cases where we step over interface counts. 5202 if (lpointee->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 5203 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5204 << lpointee << lex->getSourceRange(); 5205 return QualType(); 5206 } 5207 5208 // The result type of a pointer-int computation is the pointer type. 5209 if (rex->getType()->isIntegerType()) { 5210 if (ComplainAboutVoid) 5211 Diag(Loc, diag::ext_gnu_void_ptr) 5212 << lex->getSourceRange() << rex->getSourceRange(); 5213 if (ComplainAboutFunc) 5214 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5215 << ComplainAboutFunc->getType() 5216 << ComplainAboutFunc->getSourceRange(); 5217 5218 if (CompLHSTy) *CompLHSTy = lex->getType(); 5219 return lex->getType(); 5220 } 5221 5222 // Handle pointer-pointer subtractions. 5223 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5224 QualType rpointee = RHSPTy->getPointeeType(); 5225 5226 // RHS must be a completely-type object type. 5227 // Handle the GNU void* extension. 5228 if (rpointee->isVoidType()) { 5229 if (getLangOptions().CPlusPlus) { 5230 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5231 << lex->getSourceRange() << rex->getSourceRange(); 5232 return QualType(); 5233 } 5234 5235 ComplainAboutVoid = true; 5236 } else if (rpointee->isFunctionType()) { 5237 if (getLangOptions().CPlusPlus) { 5238 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5239 << rex->getType() << rex->getSourceRange(); 5240 return QualType(); 5241 } 5242 5243 // GNU extension: arithmetic on pointer to function 5244 if (!ComplainAboutFunc) 5245 ComplainAboutFunc = rex; 5246 } else if (!rpointee->isDependentType() && 5247 RequireCompleteType(Loc, rpointee, 5248 PDiag(diag::err_typecheck_sub_ptr_object) 5249 << rex->getSourceRange() 5250 << rex->getType())) 5251 return QualType(); 5252 5253 if (getLangOptions().CPlusPlus) { 5254 // Pointee types must be the same: C++ [expr.add] 5255 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5256 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5257 << lex->getType() << rex->getType() 5258 << lex->getSourceRange() << rex->getSourceRange(); 5259 return QualType(); 5260 } 5261 } else { 5262 // Pointee types must be compatible C99 6.5.6p3 5263 if (!Context.typesAreCompatible( 5264 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5265 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5266 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5267 << lex->getType() << rex->getType() 5268 << lex->getSourceRange() << rex->getSourceRange(); 5269 return QualType(); 5270 } 5271 } 5272 5273 if (ComplainAboutVoid) 5274 Diag(Loc, diag::ext_gnu_void_ptr) 5275 << lex->getSourceRange() << rex->getSourceRange(); 5276 if (ComplainAboutFunc) 5277 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5278 << ComplainAboutFunc->getType() 5279 << ComplainAboutFunc->getSourceRange(); 5280 5281 if (CompLHSTy) *CompLHSTy = lex->getType(); 5282 return Context.getPointerDiffType(); 5283 } 5284 } 5285 5286 return InvalidOperands(Loc, lex, rex); 5287} 5288 5289// C99 6.5.7 5290QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5291 bool isCompAssign) { 5292 // C99 6.5.7p2: Each of the operands shall have integer type. 5293 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5294 return InvalidOperands(Loc, lex, rex); 5295 5296 // Vector shifts promote their scalar inputs to vector type. 5297 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5298 return CheckVectorOperands(Loc, lex, rex); 5299 5300 // Shifts don't perform usual arithmetic conversions, they just do integer 5301 // promotions on each operand. C99 6.5.7p3 5302 QualType LHSTy = Context.isPromotableBitField(lex); 5303 if (LHSTy.isNull()) { 5304 LHSTy = lex->getType(); 5305 if (LHSTy->isPromotableIntegerType()) 5306 LHSTy = Context.getPromotedIntegerType(LHSTy); 5307 } 5308 if (!isCompAssign) 5309 ImpCastExprToType(lex, LHSTy, CastExpr::CK_IntegralCast); 5310 5311 UsualUnaryConversions(rex); 5312 5313 // Sanity-check shift operands 5314 llvm::APSInt Right; 5315 // Check right/shifter operand 5316 if (!rex->isValueDependent() && 5317 rex->isIntegerConstantExpr(Right, Context)) { 5318 if (Right.isNegative()) 5319 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5320 else { 5321 llvm::APInt LeftBits(Right.getBitWidth(), 5322 Context.getTypeSize(lex->getType())); 5323 if (Right.uge(LeftBits)) 5324 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5325 } 5326 } 5327 5328 // "The type of the result is that of the promoted left operand." 5329 return LHSTy; 5330} 5331 5332// C99 6.5.8, C++ [expr.rel] 5333QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5334 unsigned OpaqueOpc, bool isRelational) { 5335 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)OpaqueOpc; 5336 5337 // Handle vector comparisons separately. 5338 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5339 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5340 5341 CheckSignCompare(lex, rex, Loc, &Opc); 5342 5343 // C99 6.5.8p3 / C99 6.5.9p4 5344 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5345 UsualArithmeticConversions(lex, rex); 5346 else { 5347 UsualUnaryConversions(lex); 5348 UsualUnaryConversions(rex); 5349 } 5350 QualType lType = lex->getType(); 5351 QualType rType = rex->getType(); 5352 5353 if (!lType->isFloatingType() 5354 && !(lType->isBlockPointerType() && isRelational)) { 5355 // For non-floating point types, check for self-comparisons of the form 5356 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5357 // often indicate logic errors in the program. 5358 // NOTE: Don't warn about comparisons of enum constants. These can arise 5359 // from macro expansions, and are usually quite deliberate. 5360 Expr *LHSStripped = lex->IgnoreParens(); 5361 Expr *RHSStripped = rex->IgnoreParens(); 5362 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) 5363 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) 5364 if (DRL->getDecl() == DRR->getDecl() && 5365 !isa<EnumConstantDecl>(DRL->getDecl())) 5366 DiagRuntimeBehavior(Loc, PDiag(diag::warn_selfcomparison)); 5367 5368 if (isa<CastExpr>(LHSStripped)) 5369 LHSStripped = LHSStripped->IgnoreParenCasts(); 5370 if (isa<CastExpr>(RHSStripped)) 5371 RHSStripped = RHSStripped->IgnoreParenCasts(); 5372 5373 // Warn about comparisons against a string constant (unless the other 5374 // operand is null), the user probably wants strcmp. 5375 Expr *literalString = 0; 5376 Expr *literalStringStripped = 0; 5377 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5378 !RHSStripped->isNullPointerConstant(Context, 5379 Expr::NPC_ValueDependentIsNull)) { 5380 literalString = lex; 5381 literalStringStripped = LHSStripped; 5382 } else if ((isa<StringLiteral>(RHSStripped) || 5383 isa<ObjCEncodeExpr>(RHSStripped)) && 5384 !LHSStripped->isNullPointerConstant(Context, 5385 Expr::NPC_ValueDependentIsNull)) { 5386 literalString = rex; 5387 literalStringStripped = RHSStripped; 5388 } 5389 5390 if (literalString) { 5391 std::string resultComparison; 5392 switch (Opc) { 5393 case BinaryOperator::LT: resultComparison = ") < 0"; break; 5394 case BinaryOperator::GT: resultComparison = ") > 0"; break; 5395 case BinaryOperator::LE: resultComparison = ") <= 0"; break; 5396 case BinaryOperator::GE: resultComparison = ") >= 0"; break; 5397 case BinaryOperator::EQ: resultComparison = ") == 0"; break; 5398 case BinaryOperator::NE: resultComparison = ") != 0"; break; 5399 default: assert(false && "Invalid comparison operator"); 5400 } 5401 5402 DiagRuntimeBehavior(Loc, 5403 PDiag(diag::warn_stringcompare) 5404 << isa<ObjCEncodeExpr>(literalStringStripped) 5405 << literalString->getSourceRange() 5406 << FixItHint::CreateReplacement(SourceRange(Loc), ", ") 5407 << FixItHint::CreateInsertion(lex->getLocStart(), "strcmp(") 5408 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(rex->getLocEnd()), 5409 resultComparison)); 5410 } 5411 } 5412 5413 // The result of comparisons is 'bool' in C++, 'int' in C. 5414 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5415 5416 if (isRelational) { 5417 if (lType->isRealType() && rType->isRealType()) 5418 return ResultTy; 5419 } else { 5420 // Check for comparisons of floating point operands using != and ==. 5421 if (lType->isFloatingType() && rType->isFloatingType()) 5422 CheckFloatComparison(Loc,lex,rex); 5423 5424 if (lType->isArithmeticType() && rType->isArithmeticType()) 5425 return ResultTy; 5426 } 5427 5428 bool LHSIsNull = lex->isNullPointerConstant(Context, 5429 Expr::NPC_ValueDependentIsNull); 5430 bool RHSIsNull = rex->isNullPointerConstant(Context, 5431 Expr::NPC_ValueDependentIsNull); 5432 5433 // All of the following pointer related warnings are GCC extensions, except 5434 // when handling null pointer constants. One day, we can consider making them 5435 // errors (when -pedantic-errors is enabled). 5436 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5437 QualType LCanPointeeTy = 5438 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5439 QualType RCanPointeeTy = 5440 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5441 5442 if (getLangOptions().CPlusPlus) { 5443 if (LCanPointeeTy == RCanPointeeTy) 5444 return ResultTy; 5445 if (!isRelational && 5446 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5447 // Valid unless comparison between non-null pointer and function pointer 5448 // This is a gcc extension compatibility comparison. 5449 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5450 && !LHSIsNull && !RHSIsNull) { 5451 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5452 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5453 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5454 return ResultTy; 5455 } 5456 } 5457 // C++ [expr.rel]p2: 5458 // [...] Pointer conversions (4.10) and qualification 5459 // conversions (4.4) are performed on pointer operands (or on 5460 // a pointer operand and a null pointer constant) to bring 5461 // them to their composite pointer type. [...] 5462 // 5463 // C++ [expr.eq]p1 uses the same notion for (in)equality 5464 // comparisons of pointers. 5465 bool NonStandardCompositeType = false; 5466 QualType T = FindCompositePointerType(lex, rex, 5467 isSFINAEContext()? 0 : &NonStandardCompositeType); 5468 if (T.isNull()) { 5469 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5470 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5471 return QualType(); 5472 } else if (NonStandardCompositeType) { 5473 Diag(Loc, 5474 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5475 << lType << rType << T 5476 << lex->getSourceRange() << rex->getSourceRange(); 5477 } 5478 5479 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5480 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5481 return ResultTy; 5482 } 5483 // C99 6.5.9p2 and C99 6.5.8p2 5484 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5485 RCanPointeeTy.getUnqualifiedType())) { 5486 // Valid unless a relational comparison of function pointers 5487 if (isRelational && LCanPointeeTy->isFunctionType()) { 5488 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5489 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5490 } 5491 } else if (!isRelational && 5492 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5493 // Valid unless comparison between non-null pointer and function pointer 5494 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5495 && !LHSIsNull && !RHSIsNull) { 5496 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5497 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5498 } 5499 } else { 5500 // Invalid 5501 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5502 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5503 } 5504 if (LCanPointeeTy != RCanPointeeTy) 5505 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5506 return ResultTy; 5507 } 5508 5509 if (getLangOptions().CPlusPlus) { 5510 // Comparison of pointers with null pointer constants and equality 5511 // comparisons of member pointers to null pointer constants. 5512 if (RHSIsNull && 5513 (lType->isPointerType() || 5514 (!isRelational && lType->isMemberPointerType()))) { 5515 ImpCastExprToType(rex, lType, CastExpr::CK_NullToMemberPointer); 5516 return ResultTy; 5517 } 5518 if (LHSIsNull && 5519 (rType->isPointerType() || 5520 (!isRelational && rType->isMemberPointerType()))) { 5521 ImpCastExprToType(lex, rType, CastExpr::CK_NullToMemberPointer); 5522 return ResultTy; 5523 } 5524 5525 // Comparison of member pointers. 5526 if (!isRelational && 5527 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5528 // C++ [expr.eq]p2: 5529 // In addition, pointers to members can be compared, or a pointer to 5530 // member and a null pointer constant. Pointer to member conversions 5531 // (4.11) and qualification conversions (4.4) are performed to bring 5532 // them to a common type. If one operand is a null pointer constant, 5533 // the common type is the type of the other operand. Otherwise, the 5534 // common type is a pointer to member type similar (4.4) to the type 5535 // of one of the operands, with a cv-qualification signature (4.4) 5536 // that is the union of the cv-qualification signatures of the operand 5537 // types. 5538 bool NonStandardCompositeType = false; 5539 QualType T = FindCompositePointerType(lex, rex, 5540 isSFINAEContext()? 0 : &NonStandardCompositeType); 5541 if (T.isNull()) { 5542 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5543 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5544 return QualType(); 5545 } else if (NonStandardCompositeType) { 5546 Diag(Loc, 5547 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5548 << lType << rType << T 5549 << lex->getSourceRange() << rex->getSourceRange(); 5550 } 5551 5552 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5553 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5554 return ResultTy; 5555 } 5556 5557 // Comparison of nullptr_t with itself. 5558 if (lType->isNullPtrType() && rType->isNullPtrType()) 5559 return ResultTy; 5560 } 5561 5562 // Handle block pointer types. 5563 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5564 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5565 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5566 5567 if (!LHSIsNull && !RHSIsNull && 5568 !Context.typesAreCompatible(lpointee, rpointee)) { 5569 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5570 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5571 } 5572 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5573 return ResultTy; 5574 } 5575 // Allow block pointers to be compared with null pointer constants. 5576 if (!isRelational 5577 && ((lType->isBlockPointerType() && rType->isPointerType()) 5578 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5579 if (!LHSIsNull && !RHSIsNull) { 5580 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5581 ->getPointeeType()->isVoidType()) 5582 || (lType->isPointerType() && lType->getAs<PointerType>() 5583 ->getPointeeType()->isVoidType()))) 5584 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5585 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5586 } 5587 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5588 return ResultTy; 5589 } 5590 5591 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5592 if (lType->isPointerType() || rType->isPointerType()) { 5593 const PointerType *LPT = lType->getAs<PointerType>(); 5594 const PointerType *RPT = rType->getAs<PointerType>(); 5595 bool LPtrToVoid = LPT ? 5596 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5597 bool RPtrToVoid = RPT ? 5598 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5599 5600 if (!LPtrToVoid && !RPtrToVoid && 5601 !Context.typesAreCompatible(lType, rType)) { 5602 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5603 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5604 } 5605 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5606 return ResultTy; 5607 } 5608 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5609 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5610 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5611 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5612 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5613 return ResultTy; 5614 } 5615 } 5616 if (lType->isAnyPointerType() && rType->isIntegerType()) { 5617 unsigned DiagID = 0; 5618 if (RHSIsNull) { 5619 if (isRelational) 5620 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5621 } else if (isRelational) 5622 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5623 else 5624 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5625 5626 if (DiagID) { 5627 Diag(Loc, DiagID) 5628 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5629 } 5630 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5631 return ResultTy; 5632 } 5633 if (lType->isIntegerType() && rType->isAnyPointerType()) { 5634 unsigned DiagID = 0; 5635 if (LHSIsNull) { 5636 if (isRelational) 5637 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5638 } else if (isRelational) 5639 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5640 else 5641 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5642 5643 if (DiagID) { 5644 Diag(Loc, DiagID) 5645 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5646 } 5647 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5648 return ResultTy; 5649 } 5650 // Handle block pointers. 5651 if (!isRelational && RHSIsNull 5652 && lType->isBlockPointerType() && rType->isIntegerType()) { 5653 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5654 return ResultTy; 5655 } 5656 if (!isRelational && LHSIsNull 5657 && lType->isIntegerType() && rType->isBlockPointerType()) { 5658 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5659 return ResultTy; 5660 } 5661 return InvalidOperands(Loc, lex, rex); 5662} 5663 5664/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5665/// operates on extended vector types. Instead of producing an IntTy result, 5666/// like a scalar comparison, a vector comparison produces a vector of integer 5667/// types. 5668QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5669 SourceLocation Loc, 5670 bool isRelational) { 5671 // Check to make sure we're operating on vectors of the same type and width, 5672 // Allowing one side to be a scalar of element type. 5673 QualType vType = CheckVectorOperands(Loc, lex, rex); 5674 if (vType.isNull()) 5675 return vType; 5676 5677 QualType lType = lex->getType(); 5678 QualType rType = rex->getType(); 5679 5680 // For non-floating point types, check for self-comparisons of the form 5681 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5682 // often indicate logic errors in the program. 5683 if (!lType->isFloatingType()) { 5684 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5685 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5686 if (DRL->getDecl() == DRR->getDecl()) 5687 DiagRuntimeBehavior(Loc, PDiag(diag::warn_selfcomparison)); 5688 } 5689 5690 // Check for comparisons of floating point operands using != and ==. 5691 if (!isRelational && lType->isFloatingType()) { 5692 assert (rType->isFloatingType()); 5693 CheckFloatComparison(Loc,lex,rex); 5694 } 5695 5696 // Return the type for the comparison, which is the same as vector type for 5697 // integer vectors, or an integer type of identical size and number of 5698 // elements for floating point vectors. 5699 if (lType->isIntegerType()) 5700 return lType; 5701 5702 const VectorType *VTy = lType->getAs<VectorType>(); 5703 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5704 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5705 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5706 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5707 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5708 5709 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5710 "Unhandled vector element size in vector compare"); 5711 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5712} 5713 5714inline QualType Sema::CheckBitwiseOperands( 5715 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5716 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5717 return CheckVectorOperands(Loc, lex, rex); 5718 5719 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5720 5721 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5722 return compType; 5723 return InvalidOperands(Loc, lex, rex); 5724} 5725 5726inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5727 Expr *&lex, Expr *&rex, SourceLocation Loc) { 5728 if (!Context.getLangOptions().CPlusPlus) { 5729 UsualUnaryConversions(lex); 5730 UsualUnaryConversions(rex); 5731 5732 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5733 return InvalidOperands(Loc, lex, rex); 5734 5735 return Context.IntTy; 5736 } 5737 5738 // C++ [expr.log.and]p1 5739 // C++ [expr.log.or]p1 5740 // The operands are both implicitly converted to type bool (clause 4). 5741 StandardConversionSequence LHS; 5742 if (!IsStandardConversion(lex, Context.BoolTy, 5743 /*InOverloadResolution=*/false, LHS)) 5744 return InvalidOperands(Loc, lex, rex); 5745 5746 if (PerformImplicitConversion(lex, Context.BoolTy, LHS, 5747 AA_Passing, /*IgnoreBaseAccess=*/false)) 5748 return InvalidOperands(Loc, lex, rex); 5749 5750 StandardConversionSequence RHS; 5751 if (!IsStandardConversion(rex, Context.BoolTy, 5752 /*InOverloadResolution=*/false, RHS)) 5753 return InvalidOperands(Loc, lex, rex); 5754 5755 if (PerformImplicitConversion(rex, Context.BoolTy, RHS, 5756 AA_Passing, /*IgnoreBaseAccess=*/false)) 5757 return InvalidOperands(Loc, lex, rex); 5758 5759 // C++ [expr.log.and]p2 5760 // C++ [expr.log.or]p2 5761 // The result is a bool. 5762 return Context.BoolTy; 5763} 5764 5765/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5766/// is a read-only property; return true if so. A readonly property expression 5767/// depends on various declarations and thus must be treated specially. 5768/// 5769static bool IsReadonlyProperty(Expr *E, Sema &S) { 5770 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5771 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5772 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5773 QualType BaseType = PropExpr->getBase()->getType(); 5774 if (const ObjCObjectPointerType *OPT = 5775 BaseType->getAsObjCInterfacePointerType()) 5776 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5777 if (S.isPropertyReadonly(PDecl, IFace)) 5778 return true; 5779 } 5780 } 5781 return false; 5782} 5783 5784/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5785/// emit an error and return true. If so, return false. 5786static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5787 SourceLocation OrigLoc = Loc; 5788 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5789 &Loc); 5790 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5791 IsLV = Expr::MLV_ReadonlyProperty; 5792 if (IsLV == Expr::MLV_Valid) 5793 return false; 5794 5795 unsigned Diag = 0; 5796 bool NeedType = false; 5797 switch (IsLV) { // C99 6.5.16p2 5798 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5799 case Expr::MLV_ArrayType: 5800 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5801 NeedType = true; 5802 break; 5803 case Expr::MLV_NotObjectType: 5804 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5805 NeedType = true; 5806 break; 5807 case Expr::MLV_LValueCast: 5808 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5809 break; 5810 case Expr::MLV_Valid: 5811 llvm_unreachable("did not take early return for MLV_Valid"); 5812 case Expr::MLV_InvalidExpression: 5813 case Expr::MLV_MemberFunction: 5814 case Expr::MLV_ClassTemporary: 5815 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5816 break; 5817 case Expr::MLV_IncompleteType: 5818 case Expr::MLV_IncompleteVoidType: 5819 return S.RequireCompleteType(Loc, E->getType(), 5820 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5821 << E->getSourceRange()); 5822 case Expr::MLV_DuplicateVectorComponents: 5823 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5824 break; 5825 case Expr::MLV_NotBlockQualified: 5826 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5827 break; 5828 case Expr::MLV_ReadonlyProperty: 5829 Diag = diag::error_readonly_property_assignment; 5830 break; 5831 case Expr::MLV_NoSetterProperty: 5832 Diag = diag::error_nosetter_property_assignment; 5833 break; 5834 case Expr::MLV_SubObjCPropertySetting: 5835 Diag = diag::error_no_subobject_property_setting; 5836 break; 5837 } 5838 5839 SourceRange Assign; 5840 if (Loc != OrigLoc) 5841 Assign = SourceRange(OrigLoc, OrigLoc); 5842 if (NeedType) 5843 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5844 else 5845 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5846 return true; 5847} 5848 5849 5850 5851// C99 6.5.16.1 5852QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5853 SourceLocation Loc, 5854 QualType CompoundType) { 5855 // Verify that LHS is a modifiable lvalue, and emit error if not. 5856 if (CheckForModifiableLvalue(LHS, Loc, *this)) 5857 return QualType(); 5858 5859 QualType LHSType = LHS->getType(); 5860 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 5861 5862 AssignConvertType ConvTy; 5863 if (CompoundType.isNull()) { 5864 // Simple assignment "x = y". 5865 ConvTy = CheckSingleAssignmentConstraints(LHSType, RHS); 5866 // Special case of NSObject attributes on c-style pointer types. 5867 if (ConvTy == IncompatiblePointer && 5868 ((Context.isObjCNSObjectType(LHSType) && 5869 RHSType->isObjCObjectPointerType()) || 5870 (Context.isObjCNSObjectType(RHSType) && 5871 LHSType->isObjCObjectPointerType()))) 5872 ConvTy = Compatible; 5873 5874 // If the RHS is a unary plus or minus, check to see if they = and + are 5875 // right next to each other. If so, the user may have typo'd "x =+ 4" 5876 // instead of "x += 4". 5877 Expr *RHSCheck = RHS; 5878 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 5879 RHSCheck = ICE->getSubExpr(); 5880 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 5881 if ((UO->getOpcode() == UnaryOperator::Plus || 5882 UO->getOpcode() == UnaryOperator::Minus) && 5883 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 5884 // Only if the two operators are exactly adjacent. 5885 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 5886 // And there is a space or other character before the subexpr of the 5887 // unary +/-. We don't want to warn on "x=-1". 5888 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 5889 UO->getSubExpr()->getLocStart().isFileID()) { 5890 Diag(Loc, diag::warn_not_compound_assign) 5891 << (UO->getOpcode() == UnaryOperator::Plus ? "+" : "-") 5892 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 5893 } 5894 } 5895 } else { 5896 // Compound assignment "x += y" 5897 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 5898 } 5899 5900 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 5901 RHS, AA_Assigning)) 5902 return QualType(); 5903 5904 // C99 6.5.16p3: The type of an assignment expression is the type of the 5905 // left operand unless the left operand has qualified type, in which case 5906 // it is the unqualified version of the type of the left operand. 5907 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 5908 // is converted to the type of the assignment expression (above). 5909 // C++ 5.17p1: the type of the assignment expression is that of its left 5910 // operand. 5911 return LHSType.getUnqualifiedType(); 5912} 5913 5914// C99 6.5.17 5915QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 5916 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 5917 // C++ does not perform this conversion (C++ [expr.comma]p1). 5918 if (!getLangOptions().CPlusPlus) 5919 DefaultFunctionArrayLvalueConversion(RHS); 5920 5921 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 5922 // incomplete in C++). 5923 5924 return RHS->getType(); 5925} 5926 5927/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 5928/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 5929QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 5930 bool isInc) { 5931 if (Op->isTypeDependent()) 5932 return Context.DependentTy; 5933 5934 QualType ResType = Op->getType(); 5935 assert(!ResType.isNull() && "no type for increment/decrement expression"); 5936 5937 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 5938 // Decrement of bool is not allowed. 5939 if (!isInc) { 5940 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 5941 return QualType(); 5942 } 5943 // Increment of bool sets it to true, but is deprecated. 5944 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 5945 } else if (ResType->isRealType()) { 5946 // OK! 5947 } else if (ResType->isAnyPointerType()) { 5948 QualType PointeeTy = ResType->getPointeeType(); 5949 5950 // C99 6.5.2.4p2, 6.5.6p2 5951 if (PointeeTy->isVoidType()) { 5952 if (getLangOptions().CPlusPlus) { 5953 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 5954 << Op->getSourceRange(); 5955 return QualType(); 5956 } 5957 5958 // Pointer to void is a GNU extension in C. 5959 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 5960 } else if (PointeeTy->isFunctionType()) { 5961 if (getLangOptions().CPlusPlus) { 5962 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 5963 << Op->getType() << Op->getSourceRange(); 5964 return QualType(); 5965 } 5966 5967 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 5968 << ResType << Op->getSourceRange(); 5969 } else if (RequireCompleteType(OpLoc, PointeeTy, 5970 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5971 << Op->getSourceRange() 5972 << ResType)) 5973 return QualType(); 5974 // Diagnose bad cases where we step over interface counts. 5975 else if (PointeeTy->isObjCInterfaceType() && LangOpts.ObjCNonFragileABI) { 5976 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 5977 << PointeeTy << Op->getSourceRange(); 5978 return QualType(); 5979 } 5980 } else if (ResType->isAnyComplexType()) { 5981 // C99 does not support ++/-- on complex types, we allow as an extension. 5982 Diag(OpLoc, diag::ext_integer_increment_complex) 5983 << ResType << Op->getSourceRange(); 5984 } else { 5985 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 5986 << ResType << int(isInc) << Op->getSourceRange(); 5987 return QualType(); 5988 } 5989 // At this point, we know we have a real, complex or pointer type. 5990 // Now make sure the operand is a modifiable lvalue. 5991 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 5992 return QualType(); 5993 return ResType; 5994} 5995 5996/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 5997/// This routine allows us to typecheck complex/recursive expressions 5998/// where the declaration is needed for type checking. We only need to 5999/// handle cases when the expression references a function designator 6000/// or is an lvalue. Here are some examples: 6001/// - &(x) => x 6002/// - &*****f => f for f a function designator. 6003/// - &s.xx => s 6004/// - &s.zz[1].yy -> s, if zz is an array 6005/// - *(x + 1) -> x, if x is an array 6006/// - &"123"[2] -> 0 6007/// - & __real__ x -> x 6008static NamedDecl *getPrimaryDecl(Expr *E) { 6009 switch (E->getStmtClass()) { 6010 case Stmt::DeclRefExprClass: 6011 return cast<DeclRefExpr>(E)->getDecl(); 6012 case Stmt::MemberExprClass: 6013 // If this is an arrow operator, the address is an offset from 6014 // the base's value, so the object the base refers to is 6015 // irrelevant. 6016 if (cast<MemberExpr>(E)->isArrow()) 6017 return 0; 6018 // Otherwise, the expression refers to a part of the base 6019 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6020 case Stmt::ArraySubscriptExprClass: { 6021 // FIXME: This code shouldn't be necessary! We should catch the implicit 6022 // promotion of register arrays earlier. 6023 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6024 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6025 if (ICE->getSubExpr()->getType()->isArrayType()) 6026 return getPrimaryDecl(ICE->getSubExpr()); 6027 } 6028 return 0; 6029 } 6030 case Stmt::UnaryOperatorClass: { 6031 UnaryOperator *UO = cast<UnaryOperator>(E); 6032 6033 switch(UO->getOpcode()) { 6034 case UnaryOperator::Real: 6035 case UnaryOperator::Imag: 6036 case UnaryOperator::Extension: 6037 return getPrimaryDecl(UO->getSubExpr()); 6038 default: 6039 return 0; 6040 } 6041 } 6042 case Stmt::ParenExprClass: 6043 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6044 case Stmt::ImplicitCastExprClass: 6045 // If the result of an implicit cast is an l-value, we care about 6046 // the sub-expression; otherwise, the result here doesn't matter. 6047 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6048 default: 6049 return 0; 6050 } 6051} 6052 6053/// CheckAddressOfOperand - The operand of & must be either a function 6054/// designator or an lvalue designating an object. If it is an lvalue, the 6055/// object cannot be declared with storage class register or be a bit field. 6056/// Note: The usual conversions are *not* applied to the operand of the & 6057/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6058/// In C++, the operand might be an overloaded function name, in which case 6059/// we allow the '&' but retain the overloaded-function type. 6060QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) { 6061 // Make sure to ignore parentheses in subsequent checks 6062 op = op->IgnoreParens(); 6063 6064 if (op->isTypeDependent()) 6065 return Context.DependentTy; 6066 6067 if (getLangOptions().C99) { 6068 // Implement C99-only parts of addressof rules. 6069 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6070 if (uOp->getOpcode() == UnaryOperator::Deref) 6071 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6072 // (assuming the deref expression is valid). 6073 return uOp->getSubExpr()->getType(); 6074 } 6075 // Technically, there should be a check for array subscript 6076 // expressions here, but the result of one is always an lvalue anyway. 6077 } 6078 NamedDecl *dcl = getPrimaryDecl(op); 6079 Expr::isLvalueResult lval = op->isLvalue(Context); 6080 6081 MemberExpr *ME = dyn_cast<MemberExpr>(op); 6082 if (lval == Expr::LV_MemberFunction && ME && 6083 isa<CXXMethodDecl>(ME->getMemberDecl())) { 6084 ValueDecl *dcl = cast<MemberExpr>(op)->getMemberDecl(); 6085 // &f where f is a member of the current object, or &o.f, or &p->f 6086 // All these are not allowed, and we need to catch them before the dcl 6087 // branch of the if, below. 6088 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6089 << dcl; 6090 // FIXME: Improve this diagnostic and provide a fixit. 6091 6092 // Now recover by acting as if the function had been accessed qualified. 6093 return Context.getMemberPointerType(op->getType(), 6094 Context.getTypeDeclType(cast<RecordDecl>(dcl->getDeclContext())) 6095 .getTypePtr()); 6096 } else if (lval == Expr::LV_ClassTemporary) { 6097 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6098 : diag::ext_typecheck_addrof_class_temporary) 6099 << op->getType() << op->getSourceRange(); 6100 if (isSFINAEContext()) 6101 return QualType(); 6102 } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6103 // C99 6.5.3.2p1 6104 // The operand must be either an l-value or a function designator 6105 if (!op->getType()->isFunctionType()) { 6106 // FIXME: emit more specific diag... 6107 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6108 << op->getSourceRange(); 6109 return QualType(); 6110 } 6111 } else if (op->getBitField()) { // C99 6.5.3.2p1 6112 // The operand cannot be a bit-field 6113 Diag(OpLoc, diag::err_typecheck_address_of) 6114 << "bit-field" << op->getSourceRange(); 6115 return QualType(); 6116 } else if (op->refersToVectorElement()) { 6117 // The operand cannot be an element of a vector 6118 Diag(OpLoc, diag::err_typecheck_address_of) 6119 << "vector element" << op->getSourceRange(); 6120 return QualType(); 6121 } else if (isa<ObjCPropertyRefExpr>(op)) { 6122 // cannot take address of a property expression. 6123 Diag(OpLoc, diag::err_typecheck_address_of) 6124 << "property expression" << op->getSourceRange(); 6125 return QualType(); 6126 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6127 // FIXME: Can LHS ever be null here? 6128 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6129 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6130 } else if (isa<UnresolvedLookupExpr>(op)) { 6131 return Context.OverloadTy; 6132 } else if (dcl) { // C99 6.5.3.2p1 6133 // We have an lvalue with a decl. Make sure the decl is not declared 6134 // with the register storage-class specifier. 6135 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6136 if (vd->getStorageClass() == VarDecl::Register) { 6137 Diag(OpLoc, diag::err_typecheck_address_of) 6138 << "register variable" << op->getSourceRange(); 6139 return QualType(); 6140 } 6141 } else if (isa<FunctionTemplateDecl>(dcl)) { 6142 return Context.OverloadTy; 6143 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6144 // Okay: we can take the address of a field. 6145 // Could be a pointer to member, though, if there is an explicit 6146 // scope qualifier for the class. 6147 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6148 DeclContext *Ctx = dcl->getDeclContext(); 6149 if (Ctx && Ctx->isRecord()) { 6150 if (FD->getType()->isReferenceType()) { 6151 Diag(OpLoc, 6152 diag::err_cannot_form_pointer_to_member_of_reference_type) 6153 << FD->getDeclName() << FD->getType(); 6154 return QualType(); 6155 } 6156 6157 return Context.getMemberPointerType(op->getType(), 6158 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6159 } 6160 } 6161 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(dcl)) { 6162 // Okay: we can take the address of a function. 6163 // As above. 6164 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier() && 6165 MD->isInstance()) 6166 return Context.getMemberPointerType(op->getType(), 6167 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6168 } else if (!isa<FunctionDecl>(dcl)) 6169 assert(0 && "Unknown/unexpected decl type"); 6170 } 6171 6172 if (lval == Expr::LV_IncompleteVoidType) { 6173 // Taking the address of a void variable is technically illegal, but we 6174 // allow it in cases which are otherwise valid. 6175 // Example: "extern void x; void* y = &x;". 6176 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6177 } 6178 6179 // If the operand has type "type", the result has type "pointer to type". 6180 return Context.getPointerType(op->getType()); 6181} 6182 6183QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6184 if (Op->isTypeDependent()) 6185 return Context.DependentTy; 6186 6187 UsualUnaryConversions(Op); 6188 QualType Ty = Op->getType(); 6189 6190 // Note that per both C89 and C99, this is always legal, even if ptype is an 6191 // incomplete type or void. It would be possible to warn about dereferencing 6192 // a void pointer, but it's completely well-defined, and such a warning is 6193 // unlikely to catch any mistakes. 6194 if (const PointerType *PT = Ty->getAs<PointerType>()) 6195 return PT->getPointeeType(); 6196 6197 if (const ObjCObjectPointerType *OPT = Ty->getAs<ObjCObjectPointerType>()) 6198 return OPT->getPointeeType(); 6199 6200 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6201 << Ty << Op->getSourceRange(); 6202 return QualType(); 6203} 6204 6205static inline BinaryOperator::Opcode ConvertTokenKindToBinaryOpcode( 6206 tok::TokenKind Kind) { 6207 BinaryOperator::Opcode Opc; 6208 switch (Kind) { 6209 default: assert(0 && "Unknown binop!"); 6210 case tok::periodstar: Opc = BinaryOperator::PtrMemD; break; 6211 case tok::arrowstar: Opc = BinaryOperator::PtrMemI; break; 6212 case tok::star: Opc = BinaryOperator::Mul; break; 6213 case tok::slash: Opc = BinaryOperator::Div; break; 6214 case tok::percent: Opc = BinaryOperator::Rem; break; 6215 case tok::plus: Opc = BinaryOperator::Add; break; 6216 case tok::minus: Opc = BinaryOperator::Sub; break; 6217 case tok::lessless: Opc = BinaryOperator::Shl; break; 6218 case tok::greatergreater: Opc = BinaryOperator::Shr; break; 6219 case tok::lessequal: Opc = BinaryOperator::LE; break; 6220 case tok::less: Opc = BinaryOperator::LT; break; 6221 case tok::greaterequal: Opc = BinaryOperator::GE; break; 6222 case tok::greater: Opc = BinaryOperator::GT; break; 6223 case tok::exclaimequal: Opc = BinaryOperator::NE; break; 6224 case tok::equalequal: Opc = BinaryOperator::EQ; break; 6225 case tok::amp: Opc = BinaryOperator::And; break; 6226 case tok::caret: Opc = BinaryOperator::Xor; break; 6227 case tok::pipe: Opc = BinaryOperator::Or; break; 6228 case tok::ampamp: Opc = BinaryOperator::LAnd; break; 6229 case tok::pipepipe: Opc = BinaryOperator::LOr; break; 6230 case tok::equal: Opc = BinaryOperator::Assign; break; 6231 case tok::starequal: Opc = BinaryOperator::MulAssign; break; 6232 case tok::slashequal: Opc = BinaryOperator::DivAssign; break; 6233 case tok::percentequal: Opc = BinaryOperator::RemAssign; break; 6234 case tok::plusequal: Opc = BinaryOperator::AddAssign; break; 6235 case tok::minusequal: Opc = BinaryOperator::SubAssign; break; 6236 case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break; 6237 case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break; 6238 case tok::ampequal: Opc = BinaryOperator::AndAssign; break; 6239 case tok::caretequal: Opc = BinaryOperator::XorAssign; break; 6240 case tok::pipeequal: Opc = BinaryOperator::OrAssign; break; 6241 case tok::comma: Opc = BinaryOperator::Comma; break; 6242 } 6243 return Opc; 6244} 6245 6246static inline UnaryOperator::Opcode ConvertTokenKindToUnaryOpcode( 6247 tok::TokenKind Kind) { 6248 UnaryOperator::Opcode Opc; 6249 switch (Kind) { 6250 default: assert(0 && "Unknown unary op!"); 6251 case tok::plusplus: Opc = UnaryOperator::PreInc; break; 6252 case tok::minusminus: Opc = UnaryOperator::PreDec; break; 6253 case tok::amp: Opc = UnaryOperator::AddrOf; break; 6254 case tok::star: Opc = UnaryOperator::Deref; break; 6255 case tok::plus: Opc = UnaryOperator::Plus; break; 6256 case tok::minus: Opc = UnaryOperator::Minus; break; 6257 case tok::tilde: Opc = UnaryOperator::Not; break; 6258 case tok::exclaim: Opc = UnaryOperator::LNot; break; 6259 case tok::kw___real: Opc = UnaryOperator::Real; break; 6260 case tok::kw___imag: Opc = UnaryOperator::Imag; break; 6261 case tok::kw___extension__: Opc = UnaryOperator::Extension; break; 6262 } 6263 return Opc; 6264} 6265 6266/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6267/// operator @p Opc at location @c TokLoc. This routine only supports 6268/// built-in operations; ActOnBinOp handles overloaded operators. 6269Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6270 unsigned Op, 6271 Expr *lhs, Expr *rhs) { 6272 QualType ResultTy; // Result type of the binary operator. 6273 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)Op; 6274 // The following two variables are used for compound assignment operators 6275 QualType CompLHSTy; // Type of LHS after promotions for computation 6276 QualType CompResultTy; // Type of computation result 6277 6278 switch (Opc) { 6279 case BinaryOperator::Assign: 6280 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6281 break; 6282 case BinaryOperator::PtrMemD: 6283 case BinaryOperator::PtrMemI: 6284 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6285 Opc == BinaryOperator::PtrMemI); 6286 break; 6287 case BinaryOperator::Mul: 6288 case BinaryOperator::Div: 6289 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6290 Opc == BinaryOperator::Div); 6291 break; 6292 case BinaryOperator::Rem: 6293 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6294 break; 6295 case BinaryOperator::Add: 6296 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6297 break; 6298 case BinaryOperator::Sub: 6299 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6300 break; 6301 case BinaryOperator::Shl: 6302 case BinaryOperator::Shr: 6303 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6304 break; 6305 case BinaryOperator::LE: 6306 case BinaryOperator::LT: 6307 case BinaryOperator::GE: 6308 case BinaryOperator::GT: 6309 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6310 break; 6311 case BinaryOperator::EQ: 6312 case BinaryOperator::NE: 6313 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6314 break; 6315 case BinaryOperator::And: 6316 case BinaryOperator::Xor: 6317 case BinaryOperator::Or: 6318 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6319 break; 6320 case BinaryOperator::LAnd: 6321 case BinaryOperator::LOr: 6322 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc); 6323 break; 6324 case BinaryOperator::MulAssign: 6325 case BinaryOperator::DivAssign: 6326 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6327 Opc == BinaryOperator::DivAssign); 6328 CompLHSTy = CompResultTy; 6329 if (!CompResultTy.isNull()) 6330 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6331 break; 6332 case BinaryOperator::RemAssign: 6333 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6334 CompLHSTy = CompResultTy; 6335 if (!CompResultTy.isNull()) 6336 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6337 break; 6338 case BinaryOperator::AddAssign: 6339 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6340 if (!CompResultTy.isNull()) 6341 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6342 break; 6343 case BinaryOperator::SubAssign: 6344 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6345 if (!CompResultTy.isNull()) 6346 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6347 break; 6348 case BinaryOperator::ShlAssign: 6349 case BinaryOperator::ShrAssign: 6350 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6351 CompLHSTy = CompResultTy; 6352 if (!CompResultTy.isNull()) 6353 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6354 break; 6355 case BinaryOperator::AndAssign: 6356 case BinaryOperator::XorAssign: 6357 case BinaryOperator::OrAssign: 6358 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6359 CompLHSTy = CompResultTy; 6360 if (!CompResultTy.isNull()) 6361 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6362 break; 6363 case BinaryOperator::Comma: 6364 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6365 break; 6366 } 6367 if (ResultTy.isNull()) 6368 return ExprError(); 6369 if (CompResultTy.isNull()) 6370 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6371 else 6372 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6373 CompLHSTy, CompResultTy, 6374 OpLoc)); 6375} 6376 6377/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6378/// ParenRange in parentheses. 6379static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6380 const PartialDiagnostic &PD, 6381 SourceRange ParenRange, 6382 const PartialDiagnostic &SecondPD, 6383 SourceRange SecondParenRange) { 6384 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(ParenRange.getEnd()); 6385 if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6386 // We can't display the parentheses, so just dig the 6387 // warning/error and return. 6388 Self.Diag(Loc, PD); 6389 return; 6390 } 6391 6392 Self.Diag(Loc, PD) 6393 << FixItHint::CreateInsertion(ParenRange.getBegin(), "(") 6394 << FixItHint::CreateInsertion(EndLoc, ")"); 6395 6396 if (!SecondPD.getDiagID()) 6397 return; 6398 6399 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6400 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6401 // We can't display the parentheses, so just dig the 6402 // warning/error and return. 6403 Self.Diag(Loc, SecondPD); 6404 return; 6405 } 6406 6407 Self.Diag(Loc, SecondPD) 6408 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6409 << FixItHint::CreateInsertion(EndLoc, ")"); 6410} 6411 6412/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6413/// operators are mixed in a way that suggests that the programmer forgot that 6414/// comparison operators have higher precedence. The most typical example of 6415/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6416static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6417 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6418 typedef BinaryOperator BinOp; 6419 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6420 rhsopc = static_cast<BinOp::Opcode>(-1); 6421 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6422 lhsopc = BO->getOpcode(); 6423 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6424 rhsopc = BO->getOpcode(); 6425 6426 // Subs are not binary operators. 6427 if (lhsopc == -1 && rhsopc == -1) 6428 return; 6429 6430 // Bitwise operations are sometimes used as eager logical ops. 6431 // Don't diagnose this. 6432 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6433 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6434 return; 6435 6436 if (BinOp::isComparisonOp(lhsopc)) 6437 SuggestParentheses(Self, OpLoc, 6438 Self.PDiag(diag::warn_precedence_bitwise_rel) 6439 << SourceRange(lhs->getLocStart(), OpLoc) 6440 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6441 lhs->getSourceRange(), 6442 Self.PDiag(diag::note_precedence_bitwise_first) 6443 << BinOp::getOpcodeStr(Opc), 6444 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd())); 6445 else if (BinOp::isComparisonOp(rhsopc)) 6446 SuggestParentheses(Self, OpLoc, 6447 Self.PDiag(diag::warn_precedence_bitwise_rel) 6448 << SourceRange(OpLoc, rhs->getLocEnd()) 6449 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6450 rhs->getSourceRange(), 6451 Self.PDiag(diag::note_precedence_bitwise_first) 6452 << BinOp::getOpcodeStr(Opc), 6453 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart())); 6454} 6455 6456/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6457/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6458/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6459static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6460 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6461 if (BinaryOperator::isBitwiseOp(Opc)) 6462 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6463} 6464 6465// Binary Operators. 'Tok' is the token for the operator. 6466Action::OwningExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6467 tok::TokenKind Kind, 6468 ExprArg LHS, ExprArg RHS) { 6469 BinaryOperator::Opcode Opc = ConvertTokenKindToBinaryOpcode(Kind); 6470 Expr *lhs = LHS.takeAs<Expr>(), *rhs = RHS.takeAs<Expr>(); 6471 6472 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6473 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6474 6475 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6476 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6477 6478 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6479} 6480 6481Action::OwningExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6482 BinaryOperator::Opcode Opc, 6483 Expr *lhs, Expr *rhs) { 6484 if (getLangOptions().CPlusPlus && 6485 (lhs->getType()->isOverloadableType() || 6486 rhs->getType()->isOverloadableType())) { 6487 // Find all of the overloaded operators visible from this 6488 // point. We perform both an operator-name lookup from the local 6489 // scope and an argument-dependent lookup based on the types of 6490 // the arguments. 6491 UnresolvedSet<16> Functions; 6492 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6493 if (S && OverOp != OO_None) 6494 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6495 Functions); 6496 6497 // Build the (potentially-overloaded, potentially-dependent) 6498 // binary operation. 6499 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6500 } 6501 6502 // Build a built-in binary operation. 6503 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6504} 6505 6506Action::OwningExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6507 unsigned OpcIn, 6508 ExprArg InputArg) { 6509 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6510 6511 // FIXME: Input is modified below, but InputArg is not updated appropriately. 6512 Expr *Input = (Expr *)InputArg.get(); 6513 QualType resultType; 6514 switch (Opc) { 6515 case UnaryOperator::OffsetOf: 6516 assert(false && "Invalid unary operator"); 6517 break; 6518 6519 case UnaryOperator::PreInc: 6520 case UnaryOperator::PreDec: 6521 case UnaryOperator::PostInc: 6522 case UnaryOperator::PostDec: 6523 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6524 Opc == UnaryOperator::PreInc || 6525 Opc == UnaryOperator::PostInc); 6526 break; 6527 case UnaryOperator::AddrOf: 6528 resultType = CheckAddressOfOperand(Input, OpLoc); 6529 break; 6530 case UnaryOperator::Deref: 6531 DefaultFunctionArrayLvalueConversion(Input); 6532 resultType = CheckIndirectionOperand(Input, OpLoc); 6533 break; 6534 case UnaryOperator::Plus: 6535 case UnaryOperator::Minus: 6536 UsualUnaryConversions(Input); 6537 resultType = Input->getType(); 6538 if (resultType->isDependentType()) 6539 break; 6540 if (resultType->isArithmeticType()) // C99 6.5.3.3p1 6541 break; 6542 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6543 resultType->isEnumeralType()) 6544 break; 6545 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6546 Opc == UnaryOperator::Plus && 6547 resultType->isPointerType()) 6548 break; 6549 6550 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6551 << resultType << Input->getSourceRange()); 6552 case UnaryOperator::Not: // bitwise complement 6553 UsualUnaryConversions(Input); 6554 resultType = Input->getType(); 6555 if (resultType->isDependentType()) 6556 break; 6557 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6558 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6559 // C99 does not support '~' for complex conjugation. 6560 Diag(OpLoc, diag::ext_integer_complement_complex) 6561 << resultType << Input->getSourceRange(); 6562 else if (!resultType->isIntegerType()) 6563 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6564 << resultType << Input->getSourceRange()); 6565 break; 6566 case UnaryOperator::LNot: // logical negation 6567 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6568 DefaultFunctionArrayLvalueConversion(Input); 6569 resultType = Input->getType(); 6570 if (resultType->isDependentType()) 6571 break; 6572 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6573 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6574 << resultType << Input->getSourceRange()); 6575 // LNot always has type int. C99 6.5.3.3p5. 6576 // In C++, it's bool. C++ 5.3.1p8 6577 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6578 break; 6579 case UnaryOperator::Real: 6580 case UnaryOperator::Imag: 6581 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UnaryOperator::Real); 6582 break; 6583 case UnaryOperator::Extension: 6584 resultType = Input->getType(); 6585 break; 6586 } 6587 if (resultType.isNull()) 6588 return ExprError(); 6589 6590 InputArg.release(); 6591 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6592} 6593 6594Action::OwningExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6595 UnaryOperator::Opcode Opc, 6596 ExprArg input) { 6597 Expr *Input = (Expr*)input.get(); 6598 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6599 Opc != UnaryOperator::Extension) { 6600 // Find all of the overloaded operators visible from this 6601 // point. We perform both an operator-name lookup from the local 6602 // scope and an argument-dependent lookup based on the types of 6603 // the arguments. 6604 UnresolvedSet<16> Functions; 6605 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6606 if (S && OverOp != OO_None) 6607 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6608 Functions); 6609 6610 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, move(input)); 6611 } 6612 6613 return CreateBuiltinUnaryOp(OpLoc, Opc, move(input)); 6614} 6615 6616// Unary Operators. 'Tok' is the token for the operator. 6617Action::OwningExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6618 tok::TokenKind Op, ExprArg input) { 6619 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), move(input)); 6620} 6621 6622/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6623Sema::OwningExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6624 SourceLocation LabLoc, 6625 IdentifierInfo *LabelII) { 6626 // Look up the record for this label identifier. 6627 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 6628 6629 // If we haven't seen this label yet, create a forward reference. It 6630 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6631 if (LabelDecl == 0) 6632 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6633 6634 // Create the AST node. The address of a label always has type 'void*'. 6635 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6636 Context.getPointerType(Context.VoidTy))); 6637} 6638 6639Sema::OwningExprResult 6640Sema::ActOnStmtExpr(SourceLocation LPLoc, StmtArg substmt, 6641 SourceLocation RPLoc) { // "({..})" 6642 Stmt *SubStmt = static_cast<Stmt*>(substmt.get()); 6643 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6644 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6645 6646 bool isFileScope 6647 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6648 if (isFileScope) 6649 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6650 6651 // FIXME: there are a variety of strange constraints to enforce here, for 6652 // example, it is not possible to goto into a stmt expression apparently. 6653 // More semantic analysis is needed. 6654 6655 // If there are sub stmts in the compound stmt, take the type of the last one 6656 // as the type of the stmtexpr. 6657 QualType Ty = Context.VoidTy; 6658 6659 if (!Compound->body_empty()) { 6660 Stmt *LastStmt = Compound->body_back(); 6661 // If LastStmt is a label, skip down through into the body. 6662 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6663 LastStmt = Label->getSubStmt(); 6664 6665 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6666 Ty = LastExpr->getType(); 6667 } 6668 6669 // FIXME: Check that expression type is complete/non-abstract; statement 6670 // expressions are not lvalues. 6671 6672 substmt.release(); 6673 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6674} 6675 6676Sema::OwningExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 6677 SourceLocation BuiltinLoc, 6678 SourceLocation TypeLoc, 6679 TypeTy *argty, 6680 OffsetOfComponent *CompPtr, 6681 unsigned NumComponents, 6682 SourceLocation RPLoc) { 6683 // FIXME: This function leaks all expressions in the offset components on 6684 // error. 6685 // FIXME: Preserve type source info. 6686 QualType ArgTy = GetTypeFromParser(argty); 6687 assert(!ArgTy.isNull() && "Missing type argument!"); 6688 6689 bool Dependent = ArgTy->isDependentType(); 6690 6691 // We must have at least one component that refers to the type, and the first 6692 // one is known to be a field designator. Verify that the ArgTy represents 6693 // a struct/union/class. 6694 if (!Dependent && !ArgTy->isRecordType()) 6695 return ExprError(Diag(TypeLoc, diag::err_offsetof_record_type) << ArgTy); 6696 6697 // FIXME: Type must be complete per C99 7.17p3 because a declaring a variable 6698 // with an incomplete type would be illegal. 6699 6700 // Otherwise, create a null pointer as the base, and iteratively process 6701 // the offsetof designators. 6702 QualType ArgTyPtr = Context.getPointerType(ArgTy); 6703 Expr* Res = new (Context) ImplicitValueInitExpr(ArgTyPtr); 6704 Res = new (Context) UnaryOperator(Res, UnaryOperator::Deref, 6705 ArgTy, SourceLocation()); 6706 6707 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6708 // GCC extension, diagnose them. 6709 // FIXME: This diagnostic isn't actually visible because the location is in 6710 // a system header! 6711 if (NumComponents != 1) 6712 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6713 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6714 6715 if (!Dependent) { 6716 bool DidWarnAboutNonPOD = false; 6717 6718 if (RequireCompleteType(TypeLoc, Res->getType(), 6719 diag::err_offsetof_incomplete_type)) 6720 return ExprError(); 6721 6722 // FIXME: Dependent case loses a lot of information here. And probably 6723 // leaks like a sieve. 6724 for (unsigned i = 0; i != NumComponents; ++i) { 6725 const OffsetOfComponent &OC = CompPtr[i]; 6726 if (OC.isBrackets) { 6727 // Offset of an array sub-field. TODO: Should we allow vector elements? 6728 const ArrayType *AT = Context.getAsArrayType(Res->getType()); 6729 if (!AT) { 6730 Res->Destroy(Context); 6731 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6732 << Res->getType()); 6733 } 6734 6735 // FIXME: C++: Verify that operator[] isn't overloaded. 6736 6737 // Promote the array so it looks more like a normal array subscript 6738 // expression. 6739 DefaultFunctionArrayLvalueConversion(Res); 6740 6741 // C99 6.5.2.1p1 6742 Expr *Idx = static_cast<Expr*>(OC.U.E); 6743 // FIXME: Leaks Res 6744 if (!Idx->isTypeDependent() && !Idx->getType()->isIntegerType()) 6745 return ExprError(Diag(Idx->getLocStart(), 6746 diag::err_typecheck_subscript_not_integer) 6747 << Idx->getSourceRange()); 6748 6749 Res = new (Context) ArraySubscriptExpr(Res, Idx, AT->getElementType(), 6750 OC.LocEnd); 6751 continue; 6752 } 6753 6754 const RecordType *RC = Res->getType()->getAs<RecordType>(); 6755 if (!RC) { 6756 Res->Destroy(Context); 6757 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6758 << Res->getType()); 6759 } 6760 6761 // Get the decl corresponding to this. 6762 RecordDecl *RD = RC->getDecl(); 6763 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6764 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6765 DiagRuntimeBehavior(BuiltinLoc, 6766 PDiag(diag::warn_offsetof_non_pod_type) 6767 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6768 << Res->getType())) 6769 DidWarnAboutNonPOD = true; 6770 } 6771 6772 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6773 LookupQualifiedName(R, RD); 6774 6775 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6776 // FIXME: Leaks Res 6777 if (!MemberDecl) 6778 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6779 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, OC.LocEnd)); 6780 6781 // FIXME: C++: Verify that MemberDecl isn't a static field. 6782 // FIXME: Verify that MemberDecl isn't a bitfield. 6783 if (cast<RecordDecl>(MemberDecl->getDeclContext())->isAnonymousStructOrUnion()) { 6784 Res = BuildAnonymousStructUnionMemberReference( 6785 OC.LocEnd, MemberDecl, Res, OC.LocEnd).takeAs<Expr>(); 6786 } else { 6787 PerformObjectMemberConversion(Res, /*Qualifier=*/0, 6788 *R.begin(), MemberDecl); 6789 // MemberDecl->getType() doesn't get the right qualifiers, but it 6790 // doesn't matter here. 6791 Res = new (Context) MemberExpr(Res, false, MemberDecl, OC.LocEnd, 6792 MemberDecl->getType().getNonReferenceType()); 6793 } 6794 } 6795 } 6796 6797 return Owned(new (Context) UnaryOperator(Res, UnaryOperator::OffsetOf, 6798 Context.getSizeType(), BuiltinLoc)); 6799} 6800 6801 6802Sema::OwningExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 6803 TypeTy *arg1,TypeTy *arg2, 6804 SourceLocation RPLoc) { 6805 // FIXME: Preserve type source info. 6806 QualType argT1 = GetTypeFromParser(arg1); 6807 QualType argT2 = GetTypeFromParser(arg2); 6808 6809 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 6810 6811 if (getLangOptions().CPlusPlus) { 6812 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 6813 << SourceRange(BuiltinLoc, RPLoc); 6814 return ExprError(); 6815 } 6816 6817 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 6818 argT1, argT2, RPLoc)); 6819} 6820 6821Sema::OwningExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 6822 ExprArg cond, 6823 ExprArg expr1, ExprArg expr2, 6824 SourceLocation RPLoc) { 6825 Expr *CondExpr = static_cast<Expr*>(cond.get()); 6826 Expr *LHSExpr = static_cast<Expr*>(expr1.get()); 6827 Expr *RHSExpr = static_cast<Expr*>(expr2.get()); 6828 6829 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 6830 6831 QualType resType; 6832 bool ValueDependent = false; 6833 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 6834 resType = Context.DependentTy; 6835 ValueDependent = true; 6836 } else { 6837 // The conditional expression is required to be a constant expression. 6838 llvm::APSInt condEval(32); 6839 SourceLocation ExpLoc; 6840 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 6841 return ExprError(Diag(ExpLoc, 6842 diag::err_typecheck_choose_expr_requires_constant) 6843 << CondExpr->getSourceRange()); 6844 6845 // If the condition is > zero, then the AST type is the same as the LSHExpr. 6846 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 6847 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 6848 : RHSExpr->isValueDependent(); 6849 } 6850 6851 cond.release(); expr1.release(); expr2.release(); 6852 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 6853 resType, RPLoc, 6854 resType->isDependentType(), 6855 ValueDependent)); 6856} 6857 6858//===----------------------------------------------------------------------===// 6859// Clang Extensions. 6860//===----------------------------------------------------------------------===// 6861 6862/// ActOnBlockStart - This callback is invoked when a block literal is started. 6863void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 6864 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 6865 PushBlockScope(BlockScope, Block); 6866 CurContext->addDecl(Block); 6867 PushDeclContext(BlockScope, Block); 6868} 6869 6870void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 6871 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 6872 BlockScopeInfo *CurBlock = getCurBlock(); 6873 6874 if (ParamInfo.getNumTypeObjects() == 0 6875 || ParamInfo.getTypeObject(0).Kind != DeclaratorChunk::Function) { 6876 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 6877 QualType T = GetTypeForDeclarator(ParamInfo, CurScope); 6878 6879 if (T->isArrayType()) { 6880 Diag(ParamInfo.getSourceRange().getBegin(), 6881 diag::err_block_returns_array); 6882 return; 6883 } 6884 6885 // The parameter list is optional, if there was none, assume (). 6886 if (!T->isFunctionType()) 6887 T = Context.getFunctionType(T, 0, 0, false, 0, false, false, 0, 0, 6888 FunctionType::ExtInfo()); 6889 6890 CurBlock->hasPrototype = true; 6891 CurBlock->isVariadic = false; 6892 // Check for a valid sentinel attribute on this block. 6893 if (CurBlock->TheDecl->getAttr<SentinelAttr>()) { 6894 Diag(ParamInfo.getAttributes()->getLoc(), 6895 diag::warn_attribute_sentinel_not_variadic) << 1; 6896 // FIXME: remove the attribute. 6897 } 6898 QualType RetTy = T.getTypePtr()->getAs<FunctionType>()->getResultType(); 6899 6900 // Do not allow returning a objc interface by-value. 6901 if (RetTy->isObjCInterfaceType()) { 6902 Diag(ParamInfo.getSourceRange().getBegin(), 6903 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 6904 return; 6905 } 6906 6907 CurBlock->ReturnType = RetTy; 6908 return; 6909 } 6910 6911 // Analyze arguments to block. 6912 assert(ParamInfo.getTypeObject(0).Kind == DeclaratorChunk::Function && 6913 "Not a function declarator!"); 6914 DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getTypeObject(0).Fun; 6915 6916 CurBlock->hasPrototype = FTI.hasPrototype; 6917 CurBlock->isVariadic = true; 6918 6919 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs function that takes 6920 // no arguments, not a function that takes a single void argument. 6921 if (FTI.hasPrototype && 6922 FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && 6923 (!FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType().getCVRQualifiers()&& 6924 FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType())) { 6925 // empty arg list, don't push any params. 6926 CurBlock->isVariadic = false; 6927 } else if (FTI.hasPrototype) { 6928 for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) { 6929 ParmVarDecl *Param = FTI.ArgInfo[i].Param.getAs<ParmVarDecl>(); 6930 if (Param->getIdentifier() == 0 && 6931 !Param->isImplicit() && 6932 !Param->isInvalidDecl() && 6933 !getLangOptions().CPlusPlus) 6934 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 6935 CurBlock->Params.push_back(Param); 6936 } 6937 CurBlock->isVariadic = FTI.isVariadic; 6938 } 6939 CurBlock->TheDecl->setParams(CurBlock->Params.data(), 6940 CurBlock->Params.size()); 6941 CurBlock->TheDecl->setIsVariadic(CurBlock->isVariadic); 6942 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 6943 6944 bool ShouldCheckShadow = 6945 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 6946 6947 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 6948 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 6949 (*AI)->setOwningFunction(CurBlock->TheDecl); 6950 6951 // If this has an identifier, add it to the scope stack. 6952 if ((*AI)->getIdentifier()) { 6953 if (ShouldCheckShadow) 6954 CheckShadow(CurBlock->TheScope, *AI); 6955 6956 PushOnScopeChains(*AI, CurBlock->TheScope); 6957 } 6958 } 6959 6960 // Check for a valid sentinel attribute on this block. 6961 if (!CurBlock->isVariadic && 6962 CurBlock->TheDecl->getAttr<SentinelAttr>()) { 6963 Diag(ParamInfo.getAttributes()->getLoc(), 6964 diag::warn_attribute_sentinel_not_variadic) << 1; 6965 // FIXME: remove the attribute. 6966 } 6967 6968 // Analyze the return type. 6969 QualType T = GetTypeForDeclarator(ParamInfo, CurScope); 6970 QualType RetTy = T->getAs<FunctionType>()->getResultType(); 6971 6972 // Do not allow returning a objc interface by-value. 6973 if (RetTy->isObjCInterfaceType()) { 6974 Diag(ParamInfo.getSourceRange().getBegin(), 6975 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 6976 } else if (!RetTy->isDependentType()) 6977 CurBlock->ReturnType = RetTy; 6978} 6979 6980/// ActOnBlockError - If there is an error parsing a block, this callback 6981/// is invoked to pop the information about the block from the action impl. 6982void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 6983 // Pop off CurBlock, handle nested blocks. 6984 PopDeclContext(); 6985 PopFunctionOrBlockScope(); 6986 // FIXME: Delete the ParmVarDecl objects as well??? 6987} 6988 6989/// ActOnBlockStmtExpr - This is called when the body of a block statement 6990/// literal was successfully completed. ^(int x){...} 6991Sema::OwningExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 6992 StmtArg body, Scope *CurScope) { 6993 // If blocks are disabled, emit an error. 6994 if (!LangOpts.Blocks) 6995 Diag(CaretLoc, diag::err_blocks_disable); 6996 6997 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 6998 6999 PopDeclContext(); 7000 7001 QualType RetTy = Context.VoidTy; 7002 if (!BSI->ReturnType.isNull()) 7003 RetTy = BSI->ReturnType; 7004 7005 llvm::SmallVector<QualType, 8> ArgTypes; 7006 for (unsigned i = 0, e = BSI->Params.size(); i != e; ++i) 7007 ArgTypes.push_back(BSI->Params[i]->getType()); 7008 7009 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7010 QualType BlockTy; 7011 if (!BSI->hasPrototype) 7012 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, false, false, 0, 0, 7013 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7014 else 7015 BlockTy = Context.getFunctionType(RetTy, ArgTypes.data(), ArgTypes.size(), 7016 BSI->isVariadic, 0, false, false, 0, 0, 7017 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7018 7019 // FIXME: Check that return/parameter types are complete/non-abstract 7020 DiagnoseUnusedParameters(BSI->Params.begin(), BSI->Params.end()); 7021 BlockTy = Context.getBlockPointerType(BlockTy); 7022 7023 // If needed, diagnose invalid gotos and switches in the block. 7024 if (FunctionNeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7025 DiagnoseInvalidJumps(static_cast<CompoundStmt*>(body.get())); 7026 7027 BSI->TheDecl->setBody(body.takeAs<CompoundStmt>()); 7028 7029 bool Good = true; 7030 // Check goto/label use. 7031 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7032 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7033 LabelStmt *L = I->second; 7034 7035 // Verify that we have no forward references left. If so, there was a goto 7036 // or address of a label taken, but no definition of it. 7037 if (L->getSubStmt() != 0) 7038 continue; 7039 7040 // Emit error. 7041 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7042 Good = false; 7043 } 7044 if (!Good) { 7045 PopFunctionOrBlockScope(); 7046 return ExprError(); 7047 } 7048 7049 // Issue any analysis-based warnings. 7050 const sema::AnalysisBasedWarnings::Policy &WP = 7051 AnalysisWarnings.getDefaultPolicy(); 7052 AnalysisWarnings.IssueWarnings(WP, BSI->TheDecl, BlockTy); 7053 7054 Expr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7055 BSI->hasBlockDeclRefExprs); 7056 PopFunctionOrBlockScope(); 7057 return Owned(Result); 7058} 7059 7060Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7061 ExprArg expr, TypeTy *type, 7062 SourceLocation RPLoc) { 7063 QualType T = GetTypeFromParser(type); 7064 Expr *E = static_cast<Expr*>(expr.get()); 7065 Expr *OrigExpr = E; 7066 7067 InitBuiltinVaListType(); 7068 7069 // Get the va_list type 7070 QualType VaListType = Context.getBuiltinVaListType(); 7071 if (VaListType->isArrayType()) { 7072 // Deal with implicit array decay; for example, on x86-64, 7073 // va_list is an array, but it's supposed to decay to 7074 // a pointer for va_arg. 7075 VaListType = Context.getArrayDecayedType(VaListType); 7076 // Make sure the input expression also decays appropriately. 7077 UsualUnaryConversions(E); 7078 } else { 7079 // Otherwise, the va_list argument must be an l-value because 7080 // it is modified by va_arg. 7081 if (!E->isTypeDependent() && 7082 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7083 return ExprError(); 7084 } 7085 7086 if (!E->isTypeDependent() && 7087 !Context.hasSameType(VaListType, E->getType())) { 7088 return ExprError(Diag(E->getLocStart(), 7089 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7090 << OrigExpr->getType() << E->getSourceRange()); 7091 } 7092 7093 // FIXME: Check that type is complete/non-abstract 7094 // FIXME: Warn if a non-POD type is passed in. 7095 7096 expr.release(); 7097 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, T.getNonReferenceType(), 7098 RPLoc)); 7099} 7100 7101Sema::OwningExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7102 // The type of __null will be int or long, depending on the size of 7103 // pointers on the target. 7104 QualType Ty; 7105 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7106 Ty = Context.IntTy; 7107 else 7108 Ty = Context.LongTy; 7109 7110 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7111} 7112 7113static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7114 Expr *SrcExpr, FixItHint &Hint) { 7115 if (!SemaRef.getLangOptions().ObjC1) 7116 return; 7117 7118 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7119 if (!PT) 7120 return; 7121 7122 // Check if the destination is of type 'id'. 7123 if (!PT->isObjCIdType()) { 7124 // Check if the destination is the 'NSString' interface. 7125 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7126 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7127 return; 7128 } 7129 7130 // Strip off any parens and casts. 7131 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7132 if (!SL || SL->isWide()) 7133 return; 7134 7135 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7136} 7137 7138bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7139 SourceLocation Loc, 7140 QualType DstType, QualType SrcType, 7141 Expr *SrcExpr, AssignmentAction Action) { 7142 // Decode the result (notice that AST's are still created for extensions). 7143 bool isInvalid = false; 7144 unsigned DiagKind; 7145 FixItHint Hint; 7146 7147 switch (ConvTy) { 7148 default: assert(0 && "Unknown conversion type"); 7149 case Compatible: return false; 7150 case PointerToInt: 7151 DiagKind = diag::ext_typecheck_convert_pointer_int; 7152 break; 7153 case IntToPointer: 7154 DiagKind = diag::ext_typecheck_convert_int_pointer; 7155 break; 7156 case IncompatiblePointer: 7157 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7158 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7159 break; 7160 case IncompatiblePointerSign: 7161 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7162 break; 7163 case FunctionVoidPointer: 7164 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7165 break; 7166 case CompatiblePointerDiscardsQualifiers: 7167 // If the qualifiers lost were because we were applying the 7168 // (deprecated) C++ conversion from a string literal to a char* 7169 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7170 // Ideally, this check would be performed in 7171 // CheckPointerTypesForAssignment. However, that would require a 7172 // bit of refactoring (so that the second argument is an 7173 // expression, rather than a type), which should be done as part 7174 // of a larger effort to fix CheckPointerTypesForAssignment for 7175 // C++ semantics. 7176 if (getLangOptions().CPlusPlus && 7177 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7178 return false; 7179 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7180 break; 7181 case IncompatibleNestedPointerQualifiers: 7182 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7183 break; 7184 case IntToBlockPointer: 7185 DiagKind = diag::err_int_to_block_pointer; 7186 break; 7187 case IncompatibleBlockPointer: 7188 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7189 break; 7190 case IncompatibleObjCQualifiedId: 7191 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7192 // it can give a more specific diagnostic. 7193 DiagKind = diag::warn_incompatible_qualified_id; 7194 break; 7195 case IncompatibleVectors: 7196 DiagKind = diag::warn_incompatible_vectors; 7197 break; 7198 case Incompatible: 7199 DiagKind = diag::err_typecheck_convert_incompatible; 7200 isInvalid = true; 7201 break; 7202 } 7203 7204 Diag(Loc, DiagKind) << DstType << SrcType << Action 7205 << SrcExpr->getSourceRange() << Hint; 7206 return isInvalid; 7207} 7208 7209bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7210 llvm::APSInt ICEResult; 7211 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7212 if (Result) 7213 *Result = ICEResult; 7214 return false; 7215 } 7216 7217 Expr::EvalResult EvalResult; 7218 7219 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7220 EvalResult.HasSideEffects) { 7221 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7222 7223 if (EvalResult.Diag) { 7224 // We only show the note if it's not the usual "invalid subexpression" 7225 // or if it's actually in a subexpression. 7226 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7227 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7228 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7229 } 7230 7231 return true; 7232 } 7233 7234 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7235 E->getSourceRange(); 7236 7237 if (EvalResult.Diag && 7238 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7239 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7240 7241 if (Result) 7242 *Result = EvalResult.Val.getInt(); 7243 return false; 7244} 7245 7246void 7247Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7248 ExprEvalContexts.push_back( 7249 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7250} 7251 7252void 7253Sema::PopExpressionEvaluationContext() { 7254 // Pop the current expression evaluation context off the stack. 7255 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7256 ExprEvalContexts.pop_back(); 7257 7258 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7259 if (Rec.PotentiallyReferenced) { 7260 // Mark any remaining declarations in the current position of the stack 7261 // as "referenced". If they were not meant to be referenced, semantic 7262 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7263 for (PotentiallyReferencedDecls::iterator 7264 I = Rec.PotentiallyReferenced->begin(), 7265 IEnd = Rec.PotentiallyReferenced->end(); 7266 I != IEnd; ++I) 7267 MarkDeclarationReferenced(I->first, I->second); 7268 } 7269 7270 if (Rec.PotentiallyDiagnosed) { 7271 // Emit any pending diagnostics. 7272 for (PotentiallyEmittedDiagnostics::iterator 7273 I = Rec.PotentiallyDiagnosed->begin(), 7274 IEnd = Rec.PotentiallyDiagnosed->end(); 7275 I != IEnd; ++I) 7276 Diag(I->first, I->second); 7277 } 7278 } 7279 7280 // When are coming out of an unevaluated context, clear out any 7281 // temporaries that we may have created as part of the evaluation of 7282 // the expression in that context: they aren't relevant because they 7283 // will never be constructed. 7284 if (Rec.Context == Unevaluated && 7285 ExprTemporaries.size() > Rec.NumTemporaries) 7286 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7287 ExprTemporaries.end()); 7288 7289 // Destroy the popped expression evaluation record. 7290 Rec.Destroy(); 7291} 7292 7293/// \brief Note that the given declaration was referenced in the source code. 7294/// 7295/// This routine should be invoke whenever a given declaration is referenced 7296/// in the source code, and where that reference occurred. If this declaration 7297/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7298/// C99 6.9p3), then the declaration will be marked as used. 7299/// 7300/// \param Loc the location where the declaration was referenced. 7301/// 7302/// \param D the declaration that has been referenced by the source code. 7303void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7304 assert(D && "No declaration?"); 7305 7306 if (D->isUsed()) 7307 return; 7308 7309 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7310 // template or not. The reason for this is that unevaluated expressions 7311 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7312 // -Wunused-parameters) 7313 if (isa<ParmVarDecl>(D) || 7314 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7315 D->setUsed(true); 7316 return; 7317 } 7318 7319 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7320 return; 7321 7322 // Do not mark anything as "used" within a dependent context; wait for 7323 // an instantiation. 7324 if (CurContext->isDependentContext()) 7325 return; 7326 7327 switch (ExprEvalContexts.back().Context) { 7328 case Unevaluated: 7329 // We are in an expression that is not potentially evaluated; do nothing. 7330 return; 7331 7332 case PotentiallyEvaluated: 7333 // We are in a potentially-evaluated expression, so this declaration is 7334 // "used"; handle this below. 7335 break; 7336 7337 case PotentiallyPotentiallyEvaluated: 7338 // We are in an expression that may be potentially evaluated; queue this 7339 // declaration reference until we know whether the expression is 7340 // potentially evaluated. 7341 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7342 return; 7343 } 7344 7345 // Note that this declaration has been used. 7346 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7347 unsigned TypeQuals; 7348 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7349 if (!Constructor->isUsed()) 7350 DefineImplicitDefaultConstructor(Loc, Constructor); 7351 } else if (Constructor->isImplicit() && 7352 Constructor->isCopyConstructor(TypeQuals)) { 7353 if (!Constructor->isUsed()) 7354 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7355 } 7356 7357 MaybeMarkVirtualMembersReferenced(Loc, Constructor); 7358 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7359 if (Destructor->isImplicit() && !Destructor->isUsed()) 7360 DefineImplicitDestructor(Loc, Destructor); 7361 7362 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7363 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7364 MethodDecl->getOverloadedOperator() == OO_Equal) { 7365 if (!MethodDecl->isUsed()) 7366 DefineImplicitOverloadedAssign(Loc, MethodDecl); 7367 } 7368 } 7369 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7370 // Implicit instantiation of function templates and member functions of 7371 // class templates. 7372 if (!Function->getBody() && Function->isImplicitlyInstantiable()) { 7373 bool AlreadyInstantiated = false; 7374 if (FunctionTemplateSpecializationInfo *SpecInfo 7375 = Function->getTemplateSpecializationInfo()) { 7376 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7377 SpecInfo->setPointOfInstantiation(Loc); 7378 else if (SpecInfo->getTemplateSpecializationKind() 7379 == TSK_ImplicitInstantiation) 7380 AlreadyInstantiated = true; 7381 } else if (MemberSpecializationInfo *MSInfo 7382 = Function->getMemberSpecializationInfo()) { 7383 if (MSInfo->getPointOfInstantiation().isInvalid()) 7384 MSInfo->setPointOfInstantiation(Loc); 7385 else if (MSInfo->getTemplateSpecializationKind() 7386 == TSK_ImplicitInstantiation) 7387 AlreadyInstantiated = true; 7388 } 7389 7390 if (!AlreadyInstantiated) { 7391 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7392 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7393 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7394 Loc)); 7395 else 7396 PendingImplicitInstantiations.push_back(std::make_pair(Function, 7397 Loc)); 7398 } 7399 } 7400 7401 // FIXME: keep track of references to static functions 7402 Function->setUsed(true); 7403 7404 return; 7405 } 7406 7407 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7408 // Implicit instantiation of static data members of class templates. 7409 if (Var->isStaticDataMember() && 7410 Var->getInstantiatedFromStaticDataMember()) { 7411 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7412 assert(MSInfo && "Missing member specialization information?"); 7413 if (MSInfo->getPointOfInstantiation().isInvalid() && 7414 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7415 MSInfo->setPointOfInstantiation(Loc); 7416 PendingImplicitInstantiations.push_back(std::make_pair(Var, Loc)); 7417 } 7418 } 7419 7420 // FIXME: keep track of references to static data? 7421 7422 D->setUsed(true); 7423 return; 7424 } 7425} 7426 7427/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7428/// of the program being compiled. 7429/// 7430/// This routine emits the given diagnostic when the code currently being 7431/// type-checked is "potentially evaluated", meaning that there is a 7432/// possibility that the code will actually be executable. Code in sizeof() 7433/// expressions, code used only during overload resolution, etc., are not 7434/// potentially evaluated. This routine will suppress such diagnostics or, 7435/// in the absolutely nutty case of potentially potentially evaluated 7436/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7437/// later. 7438/// 7439/// This routine should be used for all diagnostics that describe the run-time 7440/// behavior of a program, such as passing a non-POD value through an ellipsis. 7441/// Failure to do so will likely result in spurious diagnostics or failures 7442/// during overload resolution or within sizeof/alignof/typeof/typeid. 7443bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7444 const PartialDiagnostic &PD) { 7445 switch (ExprEvalContexts.back().Context ) { 7446 case Unevaluated: 7447 // The argument will never be evaluated, so don't complain. 7448 break; 7449 7450 case PotentiallyEvaluated: 7451 Diag(Loc, PD); 7452 return true; 7453 7454 case PotentiallyPotentiallyEvaluated: 7455 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7456 break; 7457 } 7458 7459 return false; 7460} 7461 7462bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7463 CallExpr *CE, FunctionDecl *FD) { 7464 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7465 return false; 7466 7467 PartialDiagnostic Note = 7468 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7469 << FD->getDeclName() : PDiag(); 7470 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7471 7472 if (RequireCompleteType(Loc, ReturnType, 7473 FD ? 7474 PDiag(diag::err_call_function_incomplete_return) 7475 << CE->getSourceRange() << FD->getDeclName() : 7476 PDiag(diag::err_call_incomplete_return) 7477 << CE->getSourceRange(), 7478 std::make_pair(NoteLoc, Note))) 7479 return true; 7480 7481 return false; 7482} 7483 7484// Diagnose the common s/=/==/ typo. Note that adding parentheses 7485// will prevent this condition from triggering, which is what we want. 7486void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7487 SourceLocation Loc; 7488 7489 unsigned diagnostic = diag::warn_condition_is_assignment; 7490 7491 if (isa<BinaryOperator>(E)) { 7492 BinaryOperator *Op = cast<BinaryOperator>(E); 7493 if (Op->getOpcode() != BinaryOperator::Assign) 7494 return; 7495 7496 // Greylist some idioms by putting them into a warning subcategory. 7497 if (ObjCMessageExpr *ME 7498 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7499 Selector Sel = ME->getSelector(); 7500 7501 // self = [<foo> init...] 7502 if (isSelfExpr(Op->getLHS()) 7503 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7504 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7505 7506 // <foo> = [<bar> nextObject] 7507 else if (Sel.isUnarySelector() && 7508 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7509 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7510 } 7511 7512 Loc = Op->getOperatorLoc(); 7513 } else if (isa<CXXOperatorCallExpr>(E)) { 7514 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7515 if (Op->getOperator() != OO_Equal) 7516 return; 7517 7518 Loc = Op->getOperatorLoc(); 7519 } else { 7520 // Not an assignment. 7521 return; 7522 } 7523 7524 SourceLocation Open = E->getSourceRange().getBegin(); 7525 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7526 7527 Diag(Loc, diagnostic) 7528 << E->getSourceRange() 7529 << FixItHint::CreateInsertion(Open, "(") 7530 << FixItHint::CreateInsertion(Close, ")"); 7531 Diag(Loc, diag::note_condition_assign_to_comparison) 7532 << FixItHint::CreateReplacement(Loc, "=="); 7533} 7534 7535bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7536 DiagnoseAssignmentAsCondition(E); 7537 7538 if (!E->isTypeDependent()) { 7539 DefaultFunctionArrayLvalueConversion(E); 7540 7541 QualType T = E->getType(); 7542 7543 if (getLangOptions().CPlusPlus) { 7544 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7545 return true; 7546 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7547 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7548 << T << E->getSourceRange(); 7549 return true; 7550 } 7551 } 7552 7553 return false; 7554} 7555