SemaExpr.cpp revision e5e113a803072ec06d440c882c4f2f67f45c93f1
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 "clang/Sema/Sema.h" 15#include "clang/Sema/Initialization.h" 16#include "clang/Sema/Lookup.h" 17#include "clang/Sema/AnalysisBasedWarnings.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/CXXInheritance.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/ExprObjC.h" 25#include "clang/AST/RecursiveASTVisitor.h" 26#include "clang/AST/TypeLoc.h" 27#include "clang/Basic/PartialDiagnostic.h" 28#include "clang/Basic/SourceManager.h" 29#include "clang/Basic/TargetInfo.h" 30#include "clang/Lex/LiteralSupport.h" 31#include "clang/Lex/Preprocessor.h" 32#include "clang/Sema/DeclSpec.h" 33#include "clang/Sema/Designator.h" 34#include "clang/Sema/Scope.h" 35#include "clang/Sema/ParsedTemplate.h" 36using namespace clang; 37 38 39/// \brief Determine whether the use of this declaration is valid, and 40/// emit any corresponding diagnostics. 41/// 42/// This routine diagnoses various problems with referencing 43/// declarations that can occur when using a declaration. For example, 44/// it might warn if a deprecated or unavailable declaration is being 45/// used, or produce an error (and return true) if a C++0x deleted 46/// function is being used. 47/// 48/// If IgnoreDeprecated is set to true, this should not want about deprecated 49/// decls. 50/// 51/// \returns true if there was an error (this declaration cannot be 52/// referenced), false otherwise. 53/// 54bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) { 55 // See if the decl is deprecated. 56 if (D->getAttr<DeprecatedAttr>()) { 57 EmitDeprecationWarning(D, Loc); 58 } 59 60 // See if the decl is unavailable 61 if (D->getAttr<UnavailableAttr>()) { 62 Diag(Loc, diag::err_unavailable) << D->getDeclName(); 63 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 64 } 65 66 // See if this is a deleted function. 67 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 68 if (FD->isDeleted()) { 69 Diag(Loc, diag::err_deleted_function_use); 70 Diag(D->getLocation(), diag::note_unavailable_here) << true; 71 return true; 72 } 73 } 74 75 return false; 76} 77 78/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 79/// (and other functions in future), which have been declared with sentinel 80/// attribute. It warns if call does not have the sentinel argument. 81/// 82void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 83 Expr **Args, unsigned NumArgs) { 84 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 85 if (!attr) 86 return; 87 88 // FIXME: In C++0x, if any of the arguments are parameter pack 89 // expansions, we can't check for the sentinel now. 90 int sentinelPos = attr->getSentinel(); 91 int nullPos = attr->getNullPos(); 92 93 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 94 // base class. Then we won't be needing two versions of the same code. 95 unsigned int i = 0; 96 bool warnNotEnoughArgs = false; 97 int isMethod = 0; 98 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 99 // skip over named parameters. 100 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 101 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 102 if (nullPos) 103 --nullPos; 104 else 105 ++i; 106 } 107 warnNotEnoughArgs = (P != E || i >= NumArgs); 108 isMethod = 1; 109 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 110 // skip over named parameters. 111 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 112 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 113 if (nullPos) 114 --nullPos; 115 else 116 ++i; 117 } 118 warnNotEnoughArgs = (P != E || i >= NumArgs); 119 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 120 // block or function pointer call. 121 QualType Ty = V->getType(); 122 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 123 const FunctionType *FT = Ty->isFunctionPointerType() 124 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 125 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 126 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 127 unsigned NumArgsInProto = Proto->getNumArgs(); 128 unsigned k; 129 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 130 if (nullPos) 131 --nullPos; 132 else 133 ++i; 134 } 135 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 136 } 137 if (Ty->isBlockPointerType()) 138 isMethod = 2; 139 } else 140 return; 141 } else 142 return; 143 144 if (warnNotEnoughArgs) { 145 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 146 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 147 return; 148 } 149 int sentinel = i; 150 while (sentinelPos > 0 && i < NumArgs-1) { 151 --sentinelPos; 152 ++i; 153 } 154 if (sentinelPos > 0) { 155 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 156 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 157 return; 158 } 159 while (i < NumArgs-1) { 160 ++i; 161 ++sentinel; 162 } 163 Expr *sentinelExpr = Args[sentinel]; 164 if (!sentinelExpr) return; 165 if (sentinelExpr->isTypeDependent()) return; 166 if (sentinelExpr->isValueDependent()) return; 167 if (sentinelExpr->getType()->isAnyPointerType() && 168 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 169 Expr::NPC_ValueDependentIsNull)) 170 return; 171 172 // Unfortunately, __null has type 'int'. 173 if (isa<GNUNullExpr>(sentinelExpr)) return; 174 175 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 176 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 177} 178 179SourceRange Sema::getExprRange(ExprTy *E) const { 180 Expr *Ex = (Expr *)E; 181 return Ex? Ex->getSourceRange() : SourceRange(); 182} 183 184//===----------------------------------------------------------------------===// 185// Standard Promotions and Conversions 186//===----------------------------------------------------------------------===// 187 188/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 189void Sema::DefaultFunctionArrayConversion(Expr *&E) { 190 QualType Ty = E->getType(); 191 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 192 193 if (Ty->isFunctionType()) 194 ImpCastExprToType(E, Context.getPointerType(Ty), 195 CastExpr::CK_FunctionToPointerDecay); 196 else if (Ty->isArrayType()) { 197 // In C90 mode, arrays only promote to pointers if the array expression is 198 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 199 // type 'array of type' is converted to an expression that has type 'pointer 200 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 201 // that has type 'array of type' ...". The relevant change is "an lvalue" 202 // (C90) to "an expression" (C99). 203 // 204 // C++ 4.2p1: 205 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 206 // T" can be converted to an rvalue of type "pointer to T". 207 // 208 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 209 E->isLvalue(Context) == Expr::LV_Valid) 210 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 211 CastExpr::CK_ArrayToPointerDecay); 212 } 213} 214 215void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 216 DefaultFunctionArrayConversion(E); 217 218 QualType Ty = E->getType(); 219 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 220 if (!Ty->isDependentType() && Ty.hasQualifiers() && 221 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 222 E->isLvalue(Context) == Expr::LV_Valid) { 223 // C++ [conv.lval]p1: 224 // [...] If T is a non-class type, the type of the rvalue is the 225 // cv-unqualified version of T. Otherwise, the type of the 226 // rvalue is T 227 // 228 // C99 6.3.2.1p2: 229 // If the lvalue has qualified type, the value has the unqualified 230 // version of the type of the lvalue; otherwise, the value has the 231 // type of the lvalue. 232 ImpCastExprToType(E, Ty.getUnqualifiedType(), CastExpr::CK_NoOp); 233 } 234} 235 236 237/// UsualUnaryConversions - Performs various conversions that are common to most 238/// operators (C99 6.3). The conversions of array and function types are 239/// sometimes surpressed. For example, the array->pointer conversion doesn't 240/// apply if the array is an argument to the sizeof or address (&) operators. 241/// In these instances, this routine should *not* be called. 242Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 243 QualType Ty = Expr->getType(); 244 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 245 246 // C99 6.3.1.1p2: 247 // 248 // The following may be used in an expression wherever an int or 249 // unsigned int may be used: 250 // - an object or expression with an integer type whose integer 251 // conversion rank is less than or equal to the rank of int 252 // and unsigned int. 253 // - A bit-field of type _Bool, int, signed int, or unsigned int. 254 // 255 // If an int can represent all values of the original type, the 256 // value is converted to an int; otherwise, it is converted to an 257 // unsigned int. These are called the integer promotions. All 258 // other types are unchanged by the integer promotions. 259 QualType PTy = Context.isPromotableBitField(Expr); 260 if (!PTy.isNull()) { 261 ImpCastExprToType(Expr, PTy, CastExpr::CK_IntegralCast); 262 return Expr; 263 } 264 if (Ty->isPromotableIntegerType()) { 265 QualType PT = Context.getPromotedIntegerType(Ty); 266 ImpCastExprToType(Expr, PT, CastExpr::CK_IntegralCast); 267 return Expr; 268 } 269 270 DefaultFunctionArrayLvalueConversion(Expr); 271 return Expr; 272} 273 274/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 275/// do not have a prototype. Arguments that have type float are promoted to 276/// double. All other argument types are converted by UsualUnaryConversions(). 277void Sema::DefaultArgumentPromotion(Expr *&Expr) { 278 QualType Ty = Expr->getType(); 279 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 280 281 // If this is a 'float' (CVR qualified or typedef) promote to double. 282 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 283 return ImpCastExprToType(Expr, Context.DoubleTy, 284 CastExpr::CK_FloatingCast); 285 286 UsualUnaryConversions(Expr); 287} 288 289/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 290/// will warn if the resulting type is not a POD type, and rejects ObjC 291/// interfaces passed by value. This returns true if the argument type is 292/// completely illegal. 293bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 294 FunctionDecl *FDecl) { 295 DefaultArgumentPromotion(Expr); 296 297 // __builtin_va_start takes the second argument as a "varargs" argument, but 298 // it doesn't actually do anything with it. It doesn't need to be non-pod 299 // etc. 300 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 301 return false; 302 303 if (Expr->getType()->isObjCObjectType() && 304 DiagRuntimeBehavior(Expr->getLocStart(), 305 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 306 << Expr->getType() << CT)) 307 return true; 308 309 if (!Expr->getType()->isPODType() && 310 DiagRuntimeBehavior(Expr->getLocStart(), 311 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 312 << Expr->getType() << CT)) 313 return true; 314 315 return false; 316} 317 318 319/// UsualArithmeticConversions - Performs various conversions that are common to 320/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 321/// routine returns the first non-arithmetic type found. The client is 322/// responsible for emitting appropriate error diagnostics. 323/// FIXME: verify the conversion rules for "complex int" are consistent with 324/// GCC. 325QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 326 bool isCompAssign) { 327 if (!isCompAssign) 328 UsualUnaryConversions(lhsExpr); 329 330 UsualUnaryConversions(rhsExpr); 331 332 // For conversion purposes, we ignore any qualifiers. 333 // For example, "const float" and "float" are equivalent. 334 QualType lhs = 335 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 336 QualType rhs = 337 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 338 339 // If both types are identical, no conversion is needed. 340 if (lhs == rhs) 341 return lhs; 342 343 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 344 // The caller can deal with this (e.g. pointer + int). 345 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 346 return lhs; 347 348 // Perform bitfield promotions. 349 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 350 if (!LHSBitfieldPromoteTy.isNull()) 351 lhs = LHSBitfieldPromoteTy; 352 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 353 if (!RHSBitfieldPromoteTy.isNull()) 354 rhs = RHSBitfieldPromoteTy; 355 356 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 357 if (!isCompAssign) 358 ImpCastExprToType(lhsExpr, destType, CastExpr::CK_Unknown); 359 ImpCastExprToType(rhsExpr, destType, CastExpr::CK_Unknown); 360 return destType; 361} 362 363//===----------------------------------------------------------------------===// 364// Semantic Analysis for various Expression Types 365//===----------------------------------------------------------------------===// 366 367 368/// ActOnStringLiteral - The specified tokens were lexed as pasted string 369/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 370/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 371/// multiple tokens. However, the common case is that StringToks points to one 372/// string. 373/// 374Action::OwningExprResult 375Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 376 assert(NumStringToks && "Must have at least one string!"); 377 378 StringLiteralParser Literal(StringToks, NumStringToks, PP); 379 if (Literal.hadError) 380 return ExprError(); 381 382 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 383 for (unsigned i = 0; i != NumStringToks; ++i) 384 StringTokLocs.push_back(StringToks[i].getLocation()); 385 386 QualType StrTy = Context.CharTy; 387 if (Literal.AnyWide) StrTy = Context.getWCharType(); 388 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 389 390 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 391 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 392 StrTy.addConst(); 393 394 // Get an array type for the string, according to C99 6.4.5. This includes 395 // the nul terminator character as well as the string length for pascal 396 // strings. 397 StrTy = Context.getConstantArrayType(StrTy, 398 llvm::APInt(32, Literal.GetNumStringChars()+1), 399 ArrayType::Normal, 0); 400 401 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 402 return Owned(StringLiteral::Create(Context, Literal.GetString(), 403 Literal.GetStringLength(), 404 Literal.AnyWide, StrTy, 405 &StringTokLocs[0], 406 StringTokLocs.size())); 407} 408 409/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 410/// CurBlock to VD should cause it to be snapshotted (as we do for auto 411/// variables defined outside the block) or false if this is not needed (e.g. 412/// for values inside the block or for globals). 413/// 414/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 415/// up-to-date. 416/// 417static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 418 ValueDecl *VD) { 419 // If the value is defined inside the block, we couldn't snapshot it even if 420 // we wanted to. 421 if (CurBlock->TheDecl == VD->getDeclContext()) 422 return false; 423 424 // If this is an enum constant or function, it is constant, don't snapshot. 425 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 426 return false; 427 428 // If this is a reference to an extern, static, or global variable, no need to 429 // snapshot it. 430 // FIXME: What about 'const' variables in C++? 431 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 432 if (!Var->hasLocalStorage()) 433 return false; 434 435 // Blocks that have these can't be constant. 436 CurBlock->hasBlockDeclRefExprs = true; 437 438 // If we have nested blocks, the decl may be declared in an outer block (in 439 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 440 // be defined outside all of the current blocks (in which case the blocks do 441 // all get the bit). Walk the nesting chain. 442 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 443 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 444 445 if (!NextBlock) 446 continue; 447 448 // If we found the defining block for the variable, don't mark the block as 449 // having a reference outside it. 450 if (NextBlock->TheDecl == VD->getDeclContext()) 451 break; 452 453 // Otherwise, the DeclRef from the inner block causes the outer one to need 454 // a snapshot as well. 455 NextBlock->hasBlockDeclRefExprs = true; 456 } 457 458 return true; 459} 460 461 462Sema::OwningExprResult 463Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, SourceLocation Loc, 464 const CXXScopeSpec *SS) { 465 DeclarationNameInfo NameInfo(D->getDeclName(), Loc); 466 return BuildDeclRefExpr(D, Ty, NameInfo, SS); 467} 468 469/// BuildDeclRefExpr - Build a DeclRefExpr. 470Sema::OwningExprResult 471Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, 472 const DeclarationNameInfo &NameInfo, 473 const CXXScopeSpec *SS) { 474 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 475 Diag(NameInfo.getLoc(), 476 diag::err_auto_variable_cannot_appear_in_own_initializer) 477 << D->getDeclName(); 478 return ExprError(); 479 } 480 481 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 482 if (isa<NonTypeTemplateParmDecl>(VD)) { 483 // Non-type template parameters can be referenced anywhere they are 484 // visible. 485 Ty = Ty.getNonLValueExprType(Context); 486 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 487 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 488 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 489 Diag(NameInfo.getLoc(), 490 diag::err_reference_to_local_var_in_enclosing_function) 491 << D->getIdentifier() << FD->getDeclName(); 492 Diag(D->getLocation(), diag::note_local_variable_declared_here) 493 << D->getIdentifier(); 494 return ExprError(); 495 } 496 } 497 } 498 } 499 500 MarkDeclarationReferenced(NameInfo.getLoc(), D); 501 502 return Owned(DeclRefExpr::Create(Context, 503 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 504 SS? SS->getRange() : SourceRange(), 505 D, NameInfo, Ty)); 506} 507 508/// \brief Given a field that represents a member of an anonymous 509/// struct/union, build the path from that field's context to the 510/// actual member. 511/// 512/// Construct the sequence of field member references we'll have to 513/// perform to get to the field in the anonymous union/struct. The 514/// list of members is built from the field outward, so traverse it 515/// backwards to go from an object in the current context to the field 516/// we found. 517/// 518/// \returns The variable from which the field access should begin, 519/// for an anonymous struct/union that is not a member of another 520/// class. Otherwise, returns NULL. 521VarDecl *Sema::BuildAnonymousStructUnionMemberPath(FieldDecl *Field, 522 llvm::SmallVectorImpl<FieldDecl *> &Path) { 523 assert(Field->getDeclContext()->isRecord() && 524 cast<RecordDecl>(Field->getDeclContext())->isAnonymousStructOrUnion() 525 && "Field must be stored inside an anonymous struct or union"); 526 527 Path.push_back(Field); 528 VarDecl *BaseObject = 0; 529 DeclContext *Ctx = Field->getDeclContext(); 530 do { 531 RecordDecl *Record = cast<RecordDecl>(Ctx); 532 ValueDecl *AnonObject = Record->getAnonymousStructOrUnionObject(); 533 if (FieldDecl *AnonField = dyn_cast<FieldDecl>(AnonObject)) 534 Path.push_back(AnonField); 535 else { 536 BaseObject = cast<VarDecl>(AnonObject); 537 break; 538 } 539 Ctx = Ctx->getParent(); 540 } while (Ctx->isRecord() && 541 cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()); 542 543 return BaseObject; 544} 545 546Sema::OwningExprResult 547Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 548 FieldDecl *Field, 549 Expr *BaseObjectExpr, 550 SourceLocation OpLoc) { 551 llvm::SmallVector<FieldDecl *, 4> AnonFields; 552 VarDecl *BaseObject = BuildAnonymousStructUnionMemberPath(Field, 553 AnonFields); 554 555 // Build the expression that refers to the base object, from 556 // which we will build a sequence of member references to each 557 // of the anonymous union objects and, eventually, the field we 558 // found via name lookup. 559 bool BaseObjectIsPointer = false; 560 Qualifiers BaseQuals; 561 if (BaseObject) { 562 // BaseObject is an anonymous struct/union variable (and is, 563 // therefore, not part of another non-anonymous record). 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 DeclContext *DC = getFunctionLevelDeclContext(); 585 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 586 if (!MD->isStatic()) { 587 QualType AnonFieldType 588 = Context.getTagDeclType( 589 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 590 QualType ThisType = Context.getTagDeclType(MD->getParent()); 591 if ((Context.getCanonicalType(AnonFieldType) 592 == Context.getCanonicalType(ThisType)) || 593 IsDerivedFrom(ThisType, AnonFieldType)) { 594 // Our base object expression is "this". 595 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 596 MD->getThisType(Context), 597 /*isImplicit=*/true); 598 BaseObjectIsPointer = true; 599 } 600 } else { 601 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 602 << Field->getDeclName()); 603 } 604 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 605 } 606 607 if (!BaseObjectExpr) 608 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 609 << Field->getDeclName()); 610 } 611 612 // Build the implicit member references to the field of the 613 // anonymous struct/union. 614 Expr *Result = BaseObjectExpr; 615 Qualifiers ResultQuals = BaseQuals; 616 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 617 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 618 FI != FIEnd; ++FI) { 619 QualType MemberType = (*FI)->getType(); 620 Qualifiers MemberTypeQuals = 621 Context.getCanonicalType(MemberType).getQualifiers(); 622 623 // CVR attributes from the base are picked up by members, 624 // except that 'mutable' members don't pick up 'const'. 625 if ((*FI)->isMutable()) 626 ResultQuals.removeConst(); 627 628 // GC attributes are never picked up by members. 629 ResultQuals.removeObjCGCAttr(); 630 631 // TR 18037 does not allow fields to be declared with address spaces. 632 assert(!MemberTypeQuals.hasAddressSpace()); 633 634 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 635 if (NewQuals != MemberTypeQuals) 636 MemberType = Context.getQualifiedType(MemberType, NewQuals); 637 638 MarkDeclarationReferenced(Loc, *FI); 639 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 640 // FIXME: Might this end up being a qualified name? 641 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 642 OpLoc, MemberType); 643 BaseObjectIsPointer = false; 644 ResultQuals = NewQuals; 645 } 646 647 return Owned(Result); 648} 649 650/// Decomposes the given name into a DeclarationNameInfo, its location, and 651/// possibly a list of template arguments. 652/// 653/// If this produces template arguments, it is permitted to call 654/// DecomposeTemplateName. 655/// 656/// This actually loses a lot of source location information for 657/// non-standard name kinds; we should consider preserving that in 658/// some way. 659static void DecomposeUnqualifiedId(Sema &SemaRef, 660 const UnqualifiedId &Id, 661 TemplateArgumentListInfo &Buffer, 662 DeclarationNameInfo &NameInfo, 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 = Id.TemplateId->Template.get(); 675 SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; 676 NameInfo = SemaRef.Context.getNameForTemplate(TName, TNameLoc); 677 TemplateArgs = &Buffer; 678 } else { 679 NameInfo = SemaRef.GetNameFromUnqualifiedId(Id); 680 TemplateArgs = 0; 681 } 682} 683 684/// Determines whether the given record is "fully-formed" at the given 685/// location, i.e. whether a qualified lookup into it is assured of 686/// getting consistent results already. 687static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 688 if (!Record->hasDefinition()) 689 return false; 690 691 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 692 E = Record->bases_end(); I != E; ++I) { 693 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 694 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 695 if (!BaseRT) return false; 696 697 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 698 if (!BaseRecord->hasDefinition() || 699 !IsFullyFormedScope(SemaRef, BaseRecord)) 700 return false; 701 } 702 703 return true; 704} 705 706/// Determines if the given class is provably not derived from all of 707/// the prospective base classes. 708static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 709 CXXRecordDecl *Record, 710 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 711 if (Bases.count(Record->getCanonicalDecl())) 712 return false; 713 714 RecordDecl *RD = Record->getDefinition(); 715 if (!RD) return false; 716 Record = cast<CXXRecordDecl>(RD); 717 718 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 719 E = Record->bases_end(); I != E; ++I) { 720 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 721 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 722 if (!BaseRT) return false; 723 724 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 725 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 726 return false; 727 } 728 729 return true; 730} 731 732enum IMAKind { 733 /// The reference is definitely not an instance member access. 734 IMA_Static, 735 736 /// The reference may be an implicit instance member access. 737 IMA_Mixed, 738 739 /// The reference may be to an instance member, but it is invalid if 740 /// so, because the context is not an instance method. 741 IMA_Mixed_StaticContext, 742 743 /// The reference may be to an instance member, but it is invalid if 744 /// so, because the context is from an unrelated class. 745 IMA_Mixed_Unrelated, 746 747 /// The reference is definitely an implicit instance member access. 748 IMA_Instance, 749 750 /// The reference may be to an unresolved using declaration. 751 IMA_Unresolved, 752 753 /// The reference may be to an unresolved using declaration and the 754 /// context is not an instance method. 755 IMA_Unresolved_StaticContext, 756 757 /// The reference is to a member of an anonymous structure in a 758 /// non-class context. 759 IMA_AnonymousMember, 760 761 /// All possible referrents are instance members and the current 762 /// context is not an instance method. 763 IMA_Error_StaticContext, 764 765 /// All possible referrents are instance members of an unrelated 766 /// class. 767 IMA_Error_Unrelated 768}; 769 770/// The given lookup names class member(s) and is not being used for 771/// an address-of-member expression. Classify the type of access 772/// according to whether it's possible that this reference names an 773/// instance member. This is best-effort; it is okay to 774/// conservatively answer "yes", in which case some errors will simply 775/// not be caught until template-instantiation. 776static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 777 const LookupResult &R) { 778 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 779 780 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 781 bool isStaticContext = 782 (!isa<CXXMethodDecl>(DC) || 783 cast<CXXMethodDecl>(DC)->isStatic()); 784 785 if (R.isUnresolvableResult()) 786 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 787 788 // Collect all the declaring classes of instance members we find. 789 bool hasNonInstance = false; 790 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 791 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 792 NamedDecl *D = *I; 793 if (D->isCXXInstanceMember()) { 794 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 795 796 // If this is a member of an anonymous record, move out to the 797 // innermost non-anonymous struct or union. If there isn't one, 798 // that's a special case. 799 while (R->isAnonymousStructOrUnion()) { 800 R = dyn_cast<CXXRecordDecl>(R->getParent()); 801 if (!R) return IMA_AnonymousMember; 802 } 803 Classes.insert(R->getCanonicalDecl()); 804 } 805 else 806 hasNonInstance = true; 807 } 808 809 // If we didn't find any instance members, it can't be an implicit 810 // member reference. 811 if (Classes.empty()) 812 return IMA_Static; 813 814 // If the current context is not an instance method, it can't be 815 // an implicit member reference. 816 if (isStaticContext) 817 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 818 819 // If we can prove that the current context is unrelated to all the 820 // declaring classes, it can't be an implicit member reference (in 821 // which case it's an error if any of those members are selected). 822 if (IsProvablyNotDerivedFrom(SemaRef, 823 cast<CXXMethodDecl>(DC)->getParent(), 824 Classes)) 825 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 826 827 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 828} 829 830/// Diagnose a reference to a field with no object available. 831static void DiagnoseInstanceReference(Sema &SemaRef, 832 const CXXScopeSpec &SS, 833 const LookupResult &R) { 834 SourceLocation Loc = R.getNameLoc(); 835 SourceRange Range(Loc); 836 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 837 838 if (R.getAsSingle<FieldDecl>()) { 839 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 840 if (MD->isStatic()) { 841 // "invalid use of member 'x' in static member function" 842 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 843 << Range << R.getLookupName(); 844 return; 845 } 846 } 847 848 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 849 << R.getLookupName() << Range; 850 return; 851 } 852 853 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 854} 855 856/// Diagnose an empty lookup. 857/// 858/// \return false if new lookup candidates were found 859bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 860 CorrectTypoContext CTC) { 861 DeclarationName Name = R.getLookupName(); 862 863 unsigned diagnostic = diag::err_undeclared_var_use; 864 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 865 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 866 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 867 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 868 diagnostic = diag::err_undeclared_use; 869 diagnostic_suggest = diag::err_undeclared_use_suggest; 870 } 871 872 // If the original lookup was an unqualified lookup, fake an 873 // unqualified lookup. This is useful when (for example) the 874 // original lookup would not have found something because it was a 875 // dependent name. 876 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 877 DC; DC = DC->getParent()) { 878 if (isa<CXXRecordDecl>(DC)) { 879 LookupQualifiedName(R, DC); 880 881 if (!R.empty()) { 882 // Don't give errors about ambiguities in this lookup. 883 R.suppressDiagnostics(); 884 885 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 886 bool isInstance = CurMethod && 887 CurMethod->isInstance() && 888 DC == CurMethod->getParent(); 889 890 // Give a code modification hint to insert 'this->'. 891 // TODO: fixit for inserting 'Base<T>::' in the other cases. 892 // Actually quite difficult! 893 if (isInstance) { 894 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 895 CallsUndergoingInstantiation.back()->getCallee()); 896 CXXMethodDecl *DepMethod = cast_or_null<CXXMethodDecl>( 897 CurMethod->getInstantiatedFromMemberFunction()); 898 if (DepMethod) { 899 Diag(R.getNameLoc(), diagnostic) << Name 900 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 901 QualType DepThisType = DepMethod->getThisType(Context); 902 CXXThisExpr *DepThis = new (Context) CXXThisExpr( 903 R.getNameLoc(), DepThisType, false); 904 TemplateArgumentListInfo TList; 905 if (ULE->hasExplicitTemplateArgs()) 906 ULE->copyTemplateArgumentsInto(TList); 907 CXXDependentScopeMemberExpr *DepExpr = 908 CXXDependentScopeMemberExpr::Create( 909 Context, DepThis, DepThisType, true, SourceLocation(), 910 ULE->getQualifier(), ULE->getQualifierRange(), NULL, 911 R.getLookupNameInfo(), &TList); 912 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 913 } else { 914 // FIXME: we should be able to handle this case too. It is correct 915 // to add this-> here. This is a workaround for PR7947. 916 Diag(R.getNameLoc(), diagnostic) << Name; 917 } 918 } else { 919 Diag(R.getNameLoc(), diagnostic) << Name; 920 } 921 922 // Do we really want to note all of these? 923 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 924 Diag((*I)->getLocation(), diag::note_dependent_var_use); 925 926 // Tell the callee to try to recover. 927 return false; 928 } 929 930 R.clear(); 931 } 932 } 933 934 // We didn't find anything, so try to correct for a typo. 935 DeclarationName Corrected; 936 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 937 if (!R.empty()) { 938 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 939 if (SS.isEmpty()) 940 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 941 << FixItHint::CreateReplacement(R.getNameLoc(), 942 R.getLookupName().getAsString()); 943 else 944 Diag(R.getNameLoc(), diag::err_no_member_suggest) 945 << Name << computeDeclContext(SS, false) << R.getLookupName() 946 << SS.getRange() 947 << FixItHint::CreateReplacement(R.getNameLoc(), 948 R.getLookupName().getAsString()); 949 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 950 Diag(ND->getLocation(), diag::note_previous_decl) 951 << ND->getDeclName(); 952 953 // Tell the callee to try to recover. 954 return false; 955 } 956 957 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 958 // FIXME: If we ended up with a typo for a type name or 959 // Objective-C class name, we're in trouble because the parser 960 // is in the wrong place to recover. Suggest the typo 961 // correction, but don't make it a fix-it since we're not going 962 // to recover well anyway. 963 if (SS.isEmpty()) 964 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 965 else 966 Diag(R.getNameLoc(), diag::err_no_member_suggest) 967 << Name << computeDeclContext(SS, false) << R.getLookupName() 968 << SS.getRange(); 969 970 // Don't try to recover; it won't work. 971 return true; 972 } 973 } else { 974 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 975 // because we aren't able to recover. 976 if (SS.isEmpty()) 977 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 978 else 979 Diag(R.getNameLoc(), diag::err_no_member_suggest) 980 << Name << computeDeclContext(SS, false) << Corrected 981 << SS.getRange(); 982 return true; 983 } 984 R.clear(); 985 } 986 987 // Emit a special diagnostic for failed member lookups. 988 // FIXME: computing the declaration context might fail here (?) 989 if (!SS.isEmpty()) { 990 Diag(R.getNameLoc(), diag::err_no_member) 991 << Name << computeDeclContext(SS, false) 992 << SS.getRange(); 993 return true; 994 } 995 996 // Give up, we can't recover. 997 Diag(R.getNameLoc(), diagnostic) << Name; 998 return true; 999} 1000 1001static ObjCPropertyDecl *OkToSynthesizeProvisionalIvar(Sema &SemaRef, 1002 IdentifierInfo *II, 1003 SourceLocation NameLoc) { 1004 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1005 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1006 if (!IDecl) 1007 return 0; 1008 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1009 if (!ClassImpDecl) 1010 return 0; 1011 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1012 if (!property) 1013 return 0; 1014 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1015 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic) 1016 return 0; 1017 return property; 1018} 1019 1020static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1021 LookupResult &Lookup, 1022 IdentifierInfo *II, 1023 SourceLocation NameLoc) { 1024 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1025 bool LookForIvars; 1026 if (Lookup.empty()) 1027 LookForIvars = true; 1028 else if (CurMeth->isClassMethod()) 1029 LookForIvars = false; 1030 else 1031 LookForIvars = (Lookup.isSingleResult() && 1032 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1033 if (!LookForIvars) 1034 return 0; 1035 1036 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1037 if (!IDecl) 1038 return 0; 1039 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1040 if (!ClassImpDecl) 1041 return 0; 1042 bool DynamicImplSeen = false; 1043 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1044 if (!property) 1045 return 0; 1046 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1047 DynamicImplSeen = 1048 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1049 if (!DynamicImplSeen) { 1050 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1051 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1052 NameLoc, 1053 II, PropType, /*Dinfo=*/0, 1054 ObjCIvarDecl::Protected, 1055 (Expr *)0, true); 1056 ClassImpDecl->addDecl(Ivar); 1057 IDecl->makeDeclVisibleInContext(Ivar, false); 1058 property->setPropertyIvarDecl(Ivar); 1059 return Ivar; 1060 } 1061 return 0; 1062} 1063 1064Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S, 1065 CXXScopeSpec &SS, 1066 UnqualifiedId &Id, 1067 bool HasTrailingLParen, 1068 bool isAddressOfOperand) { 1069 assert(!(isAddressOfOperand && HasTrailingLParen) && 1070 "cannot be direct & operand and have a trailing lparen"); 1071 1072 if (SS.isInvalid()) 1073 return ExprError(); 1074 1075 TemplateArgumentListInfo TemplateArgsBuffer; 1076 1077 // Decompose the UnqualifiedId into the following data. 1078 DeclarationNameInfo NameInfo; 1079 const TemplateArgumentListInfo *TemplateArgs; 1080 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, NameInfo, TemplateArgs); 1081 1082 DeclarationName Name = NameInfo.getName(); 1083 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1084 SourceLocation NameLoc = NameInfo.getLoc(); 1085 1086 // C++ [temp.dep.expr]p3: 1087 // An id-expression is type-dependent if it contains: 1088 // -- an identifier that was declared with a dependent type, 1089 // (note: handled after lookup) 1090 // -- a template-id that is dependent, 1091 // (note: handled in BuildTemplateIdExpr) 1092 // -- a conversion-function-id that specifies a dependent type, 1093 // -- a nested-name-specifier that contains a class-name that 1094 // names a dependent type. 1095 // Determine whether this is a member of an unknown specialization; 1096 // we need to handle these differently. 1097 bool DependentID = false; 1098 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1099 Name.getCXXNameType()->isDependentType()) { 1100 DependentID = true; 1101 } else if (SS.isSet()) { 1102 DeclContext *DC = computeDeclContext(SS, false); 1103 if (DC) { 1104 if (RequireCompleteDeclContext(SS, DC)) 1105 return ExprError(); 1106 // FIXME: We should be checking whether DC is the current instantiation. 1107 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 1108 DependentID = !IsFullyFormedScope(*this, RD); 1109 } else { 1110 DependentID = true; 1111 } 1112 } 1113 1114 if (DependentID) { 1115 return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, 1116 TemplateArgs); 1117 } 1118 bool IvarLookupFollowUp = false; 1119 // Perform the required lookup. 1120 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1121 if (TemplateArgs) { 1122 // Lookup the template name again to correctly establish the context in 1123 // which it was found. This is really unfortunate as we already did the 1124 // lookup to determine that it was a template name in the first place. If 1125 // this becomes a performance hit, we can work harder to preserve those 1126 // results until we get here but it's likely not worth it. 1127 bool MemberOfUnknownSpecialization; 1128 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1129 MemberOfUnknownSpecialization); 1130 } else { 1131 IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1132 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1133 1134 // If this reference is in an Objective-C method, then we need to do 1135 // some special Objective-C lookup, too. 1136 if (IvarLookupFollowUp) { 1137 OwningExprResult E(LookupInObjCMethod(R, S, II, true)); 1138 if (E.isInvalid()) 1139 return ExprError(); 1140 1141 Expr *Ex = E.takeAs<Expr>(); 1142 if (Ex) return Owned(Ex); 1143 // Synthesize ivars lazily 1144 if (getLangOptions().ObjCNonFragileABI2) { 1145 if (SynthesizeProvisionalIvar(*this, R, II, NameLoc)) 1146 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1147 isAddressOfOperand); 1148 } 1149 // for further use, this must be set to false if in class method. 1150 IvarLookupFollowUp = getCurMethodDecl()->isInstanceMethod(); 1151 } 1152 } 1153 1154 if (R.isAmbiguous()) 1155 return ExprError(); 1156 1157 // Determine whether this name might be a candidate for 1158 // argument-dependent lookup. 1159 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1160 1161 if (R.empty() && !ADL) { 1162 // Otherwise, this could be an implicitly declared function reference (legal 1163 // in C90, extension in C99, forbidden in C++). 1164 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1165 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1166 if (D) R.addDecl(D); 1167 } 1168 1169 // If this name wasn't predeclared and if this is not a function 1170 // call, diagnose the problem. 1171 if (R.empty()) { 1172 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1173 return ExprError(); 1174 1175 assert(!R.empty() && 1176 "DiagnoseEmptyLookup returned false but added no results"); 1177 1178 // If we found an Objective-C instance variable, let 1179 // LookupInObjCMethod build the appropriate expression to 1180 // reference the ivar. 1181 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1182 R.clear(); 1183 OwningExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1184 assert(E.isInvalid() || E.get()); 1185 return move(E); 1186 } 1187 } 1188 } 1189 1190 // This is guaranteed from this point on. 1191 assert(!R.empty() || ADL); 1192 1193 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1194 if (getLangOptions().ObjCNonFragileABI && IvarLookupFollowUp && 1195 !getLangOptions().ObjCNonFragileABI2 && 1196 Var->isFileVarDecl()) { 1197 ObjCPropertyDecl *Property = 1198 OkToSynthesizeProvisionalIvar(*this, II, NameLoc); 1199 if (Property) { 1200 Diag(NameLoc, diag::warn_ivar_variable_conflict) << Var->getDeclName(); 1201 Diag(Property->getLocation(), diag::note_property_declare); 1202 Diag(Var->getLocation(), diag::note_global_declared_at); 1203 } 1204 } 1205 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1206 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1207 // C99 DR 316 says that, if a function type comes from a 1208 // function definition (without a prototype), that type is only 1209 // used for checking compatibility. Therefore, when referencing 1210 // the function, we pretend that we don't have the full function 1211 // type. 1212 if (DiagnoseUseOfDecl(Func, NameLoc)) 1213 return ExprError(); 1214 1215 QualType T = Func->getType(); 1216 QualType NoProtoType = T; 1217 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1218 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1219 Proto->getExtInfo()); 1220 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1221 } 1222 } 1223 1224 // Check whether this might be a C++ implicit instance member access. 1225 // C++ [expr.prim.general]p6: 1226 // Within the definition of a non-static member function, an 1227 // identifier that names a non-static member is transformed to a 1228 // class member access expression. 1229 // But note that &SomeClass::foo is grammatically distinct, even 1230 // though we don't parse it that way. 1231 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1232 bool isAbstractMemberPointer = (isAddressOfOperand && !SS.isEmpty()); 1233 if (!isAbstractMemberPointer) 1234 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1235 } 1236 1237 if (TemplateArgs) 1238 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1239 1240 return BuildDeclarationNameExpr(SS, R, ADL); 1241} 1242 1243/// Builds an expression which might be an implicit member expression. 1244Sema::OwningExprResult 1245Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1246 LookupResult &R, 1247 const TemplateArgumentListInfo *TemplateArgs) { 1248 switch (ClassifyImplicitMemberAccess(*this, R)) { 1249 case IMA_Instance: 1250 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1251 1252 case IMA_AnonymousMember: 1253 assert(R.isSingleResult()); 1254 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1255 R.getAsSingle<FieldDecl>()); 1256 1257 case IMA_Mixed: 1258 case IMA_Mixed_Unrelated: 1259 case IMA_Unresolved: 1260 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1261 1262 case IMA_Static: 1263 case IMA_Mixed_StaticContext: 1264 case IMA_Unresolved_StaticContext: 1265 if (TemplateArgs) 1266 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1267 return BuildDeclarationNameExpr(SS, R, false); 1268 1269 case IMA_Error_StaticContext: 1270 case IMA_Error_Unrelated: 1271 DiagnoseInstanceReference(*this, SS, R); 1272 return ExprError(); 1273 } 1274 1275 llvm_unreachable("unexpected instance member access kind"); 1276 return ExprError(); 1277} 1278 1279/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1280/// declaration name, generally during template instantiation. 1281/// There's a large number of things which don't need to be done along 1282/// this path. 1283Sema::OwningExprResult 1284Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1285 const DeclarationNameInfo &NameInfo) { 1286 DeclContext *DC; 1287 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1288 return BuildDependentDeclRefExpr(SS, NameInfo, 0); 1289 1290 if (RequireCompleteDeclContext(SS, DC)) 1291 return ExprError(); 1292 1293 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1294 LookupQualifiedName(R, DC); 1295 1296 if (R.isAmbiguous()) 1297 return ExprError(); 1298 1299 if (R.empty()) { 1300 Diag(NameInfo.getLoc(), diag::err_no_member) 1301 << NameInfo.getName() << DC << SS.getRange(); 1302 return ExprError(); 1303 } 1304 1305 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1306} 1307 1308/// LookupInObjCMethod - The parser has read a name in, and Sema has 1309/// detected that we're currently inside an ObjC method. Perform some 1310/// additional lookup. 1311/// 1312/// Ideally, most of this would be done by lookup, but there's 1313/// actually quite a lot of extra work involved. 1314/// 1315/// Returns a null sentinel to indicate trivial success. 1316Sema::OwningExprResult 1317Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1318 IdentifierInfo *II, bool AllowBuiltinCreation) { 1319 SourceLocation Loc = Lookup.getNameLoc(); 1320 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1321 1322 // There are two cases to handle here. 1) scoped lookup could have failed, 1323 // in which case we should look for an ivar. 2) scoped lookup could have 1324 // found a decl, but that decl is outside the current instance method (i.e. 1325 // a global variable). In these two cases, we do a lookup for an ivar with 1326 // this name, if the lookup sucedes, we replace it our current decl. 1327 1328 // If we're in a class method, we don't normally want to look for 1329 // ivars. But if we don't find anything else, and there's an 1330 // ivar, that's an error. 1331 bool IsClassMethod = CurMethod->isClassMethod(); 1332 1333 bool LookForIvars; 1334 if (Lookup.empty()) 1335 LookForIvars = true; 1336 else if (IsClassMethod) 1337 LookForIvars = false; 1338 else 1339 LookForIvars = (Lookup.isSingleResult() && 1340 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1341 ObjCInterfaceDecl *IFace = 0; 1342 if (LookForIvars) { 1343 IFace = CurMethod->getClassInterface(); 1344 ObjCInterfaceDecl *ClassDeclared; 1345 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1346 // Diagnose using an ivar in a class method. 1347 if (IsClassMethod) 1348 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1349 << IV->getDeclName()); 1350 1351 // If we're referencing an invalid decl, just return this as a silent 1352 // error node. The error diagnostic was already emitted on the decl. 1353 if (IV->isInvalidDecl()) 1354 return ExprError(); 1355 1356 // Check if referencing a field with __attribute__((deprecated)). 1357 if (DiagnoseUseOfDecl(IV, Loc)) 1358 return ExprError(); 1359 1360 // Diagnose the use of an ivar outside of the declaring class. 1361 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1362 ClassDeclared != IFace) 1363 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1364 1365 // FIXME: This should use a new expr for a direct reference, don't 1366 // turn this into Self->ivar, just return a BareIVarExpr or something. 1367 IdentifierInfo &II = Context.Idents.get("self"); 1368 UnqualifiedId SelfName; 1369 SelfName.setIdentifier(&II, SourceLocation()); 1370 CXXScopeSpec SelfScopeSpec; 1371 OwningExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1372 SelfName, false, false); 1373 MarkDeclarationReferenced(Loc, IV); 1374 return Owned(new (Context) 1375 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1376 SelfExpr.takeAs<Expr>(), true, true)); 1377 } 1378 } else if (CurMethod->isInstanceMethod()) { 1379 // We should warn if a local variable hides an ivar. 1380 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1381 ObjCInterfaceDecl *ClassDeclared; 1382 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1383 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1384 IFace == ClassDeclared) 1385 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1386 } 1387 } 1388 1389 if (Lookup.empty() && II && AllowBuiltinCreation) { 1390 // FIXME. Consolidate this with similar code in LookupName. 1391 if (unsigned BuiltinID = II->getBuiltinID()) { 1392 if (!(getLangOptions().CPlusPlus && 1393 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1394 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1395 S, Lookup.isForRedeclaration(), 1396 Lookup.getNameLoc()); 1397 if (D) Lookup.addDecl(D); 1398 } 1399 } 1400 } 1401 // Sentinel value saying that we didn't do anything special. 1402 return Owned((Expr*) 0); 1403} 1404 1405/// \brief Cast a base object to a member's actual type. 1406/// 1407/// Logically this happens in three phases: 1408/// 1409/// * First we cast from the base type to the naming class. 1410/// The naming class is the class into which we were looking 1411/// when we found the member; it's the qualifier type if a 1412/// qualifier was provided, and otherwise it's the base type. 1413/// 1414/// * Next we cast from the naming class to the declaring class. 1415/// If the member we found was brought into a class's scope by 1416/// a using declaration, this is that class; otherwise it's 1417/// the class declaring the member. 1418/// 1419/// * Finally we cast from the declaring class to the "true" 1420/// declaring class of the member. This conversion does not 1421/// obey access control. 1422bool 1423Sema::PerformObjectMemberConversion(Expr *&From, 1424 NestedNameSpecifier *Qualifier, 1425 NamedDecl *FoundDecl, 1426 NamedDecl *Member) { 1427 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1428 if (!RD) 1429 return false; 1430 1431 QualType DestRecordType; 1432 QualType DestType; 1433 QualType FromRecordType; 1434 QualType FromType = From->getType(); 1435 bool PointerConversions = false; 1436 if (isa<FieldDecl>(Member)) { 1437 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1438 1439 if (FromType->getAs<PointerType>()) { 1440 DestType = Context.getPointerType(DestRecordType); 1441 FromRecordType = FromType->getPointeeType(); 1442 PointerConversions = true; 1443 } else { 1444 DestType = DestRecordType; 1445 FromRecordType = FromType; 1446 } 1447 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1448 if (Method->isStatic()) 1449 return false; 1450 1451 DestType = Method->getThisType(Context); 1452 DestRecordType = DestType->getPointeeType(); 1453 1454 if (FromType->getAs<PointerType>()) { 1455 FromRecordType = FromType->getPointeeType(); 1456 PointerConversions = true; 1457 } else { 1458 FromRecordType = FromType; 1459 DestType = DestRecordType; 1460 } 1461 } else { 1462 // No conversion necessary. 1463 return false; 1464 } 1465 1466 if (DestType->isDependentType() || FromType->isDependentType()) 1467 return false; 1468 1469 // If the unqualified types are the same, no conversion is necessary. 1470 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1471 return false; 1472 1473 SourceRange FromRange = From->getSourceRange(); 1474 SourceLocation FromLoc = FromRange.getBegin(); 1475 1476 ImplicitCastExpr::ResultCategory Category = CastCategory(From); 1477 1478 // C++ [class.member.lookup]p8: 1479 // [...] Ambiguities can often be resolved by qualifying a name with its 1480 // class name. 1481 // 1482 // If the member was a qualified name and the qualified referred to a 1483 // specific base subobject type, we'll cast to that intermediate type 1484 // first and then to the object in which the member is declared. That allows 1485 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1486 // 1487 // class Base { public: int x; }; 1488 // class Derived1 : public Base { }; 1489 // class Derived2 : public Base { }; 1490 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1491 // 1492 // void VeryDerived::f() { 1493 // x = 17; // error: ambiguous base subobjects 1494 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1495 // } 1496 if (Qualifier) { 1497 QualType QType = QualType(Qualifier->getAsType(), 0); 1498 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1499 assert(QType->isRecordType() && "lookup done with non-record type"); 1500 1501 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1502 1503 // In C++98, the qualifier type doesn't actually have to be a base 1504 // type of the object type, in which case we just ignore it. 1505 // Otherwise build the appropriate casts. 1506 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1507 CXXCastPath BasePath; 1508 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1509 FromLoc, FromRange, &BasePath)) 1510 return true; 1511 1512 if (PointerConversions) 1513 QType = Context.getPointerType(QType); 1514 ImpCastExprToType(From, QType, CastExpr::CK_UncheckedDerivedToBase, 1515 Category, &BasePath); 1516 1517 FromType = QType; 1518 FromRecordType = QRecordType; 1519 1520 // If the qualifier type was the same as the destination type, 1521 // we're done. 1522 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1523 return false; 1524 } 1525 } 1526 1527 bool IgnoreAccess = false; 1528 1529 // If we actually found the member through a using declaration, cast 1530 // down to the using declaration's type. 1531 // 1532 // Pointer equality is fine here because only one declaration of a 1533 // class ever has member declarations. 1534 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1535 assert(isa<UsingShadowDecl>(FoundDecl)); 1536 QualType URecordType = Context.getTypeDeclType( 1537 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1538 1539 // We only need to do this if the naming-class to declaring-class 1540 // conversion is non-trivial. 1541 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1542 assert(IsDerivedFrom(FromRecordType, URecordType)); 1543 CXXCastPath BasePath; 1544 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1545 FromLoc, FromRange, &BasePath)) 1546 return true; 1547 1548 QualType UType = URecordType; 1549 if (PointerConversions) 1550 UType = Context.getPointerType(UType); 1551 ImpCastExprToType(From, UType, CastExpr::CK_UncheckedDerivedToBase, 1552 Category, &BasePath); 1553 FromType = UType; 1554 FromRecordType = URecordType; 1555 } 1556 1557 // We don't do access control for the conversion from the 1558 // declaring class to the true declaring class. 1559 IgnoreAccess = true; 1560 } 1561 1562 CXXCastPath BasePath; 1563 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1564 FromLoc, FromRange, &BasePath, 1565 IgnoreAccess)) 1566 return true; 1567 1568 ImpCastExprToType(From, DestType, CastExpr::CK_UncheckedDerivedToBase, 1569 Category, &BasePath); 1570 return false; 1571} 1572 1573/// \brief Build a MemberExpr AST node. 1574static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1575 const CXXScopeSpec &SS, ValueDecl *Member, 1576 DeclAccessPair FoundDecl, 1577 const DeclarationNameInfo &MemberNameInfo, 1578 QualType Ty, 1579 const TemplateArgumentListInfo *TemplateArgs = 0) { 1580 NestedNameSpecifier *Qualifier = 0; 1581 SourceRange QualifierRange; 1582 if (SS.isSet()) { 1583 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1584 QualifierRange = SS.getRange(); 1585 } 1586 1587 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1588 Member, FoundDecl, MemberNameInfo, 1589 TemplateArgs, Ty); 1590} 1591 1592/// Builds an implicit member access expression. The current context 1593/// is known to be an instance method, and the given unqualified lookup 1594/// set is known to contain only instance members, at least one of which 1595/// is from an appropriate type. 1596Sema::OwningExprResult 1597Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1598 LookupResult &R, 1599 const TemplateArgumentListInfo *TemplateArgs, 1600 bool IsKnownInstance) { 1601 assert(!R.empty() && !R.isAmbiguous()); 1602 1603 SourceLocation Loc = R.getNameLoc(); 1604 1605 // We may have found a field within an anonymous union or struct 1606 // (C++ [class.union]). 1607 // FIXME: This needs to happen post-isImplicitMemberReference? 1608 // FIXME: template-ids inside anonymous structs? 1609 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1610 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1611 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1612 1613 // If this is known to be an instance access, go ahead and build a 1614 // 'this' expression now. 1615 DeclContext *DC = getFunctionLevelDeclContext(); 1616 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 1617 Expr *This = 0; // null signifies implicit access 1618 if (IsKnownInstance) { 1619 SourceLocation Loc = R.getNameLoc(); 1620 if (SS.getRange().isValid()) 1621 Loc = SS.getRange().getBegin(); 1622 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1623 } 1624 1625 return BuildMemberReferenceExpr(This, ThisType, 1626 /*OpLoc*/ SourceLocation(), 1627 /*IsArrow*/ true, 1628 SS, 1629 /*FirstQualifierInScope*/ 0, 1630 R, TemplateArgs); 1631} 1632 1633bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1634 const LookupResult &R, 1635 bool HasTrailingLParen) { 1636 // Only when used directly as the postfix-expression of a call. 1637 if (!HasTrailingLParen) 1638 return false; 1639 1640 // Never if a scope specifier was provided. 1641 if (SS.isSet()) 1642 return false; 1643 1644 // Only in C++ or ObjC++. 1645 if (!getLangOptions().CPlusPlus) 1646 return false; 1647 1648 // Turn off ADL when we find certain kinds of declarations during 1649 // normal lookup: 1650 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1651 NamedDecl *D = *I; 1652 1653 // C++0x [basic.lookup.argdep]p3: 1654 // -- a declaration of a class member 1655 // Since using decls preserve this property, we check this on the 1656 // original decl. 1657 if (D->isCXXClassMember()) 1658 return false; 1659 1660 // C++0x [basic.lookup.argdep]p3: 1661 // -- a block-scope function declaration that is not a 1662 // using-declaration 1663 // NOTE: we also trigger this for function templates (in fact, we 1664 // don't check the decl type at all, since all other decl types 1665 // turn off ADL anyway). 1666 if (isa<UsingShadowDecl>(D)) 1667 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1668 else if (D->getDeclContext()->isFunctionOrMethod()) 1669 return false; 1670 1671 // C++0x [basic.lookup.argdep]p3: 1672 // -- a declaration that is neither a function or a function 1673 // template 1674 // And also for builtin functions. 1675 if (isa<FunctionDecl>(D)) { 1676 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1677 1678 // But also builtin functions. 1679 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1680 return false; 1681 } else if (!isa<FunctionTemplateDecl>(D)) 1682 return false; 1683 } 1684 1685 return true; 1686} 1687 1688 1689/// Diagnoses obvious problems with the use of the given declaration 1690/// as an expression. This is only actually called for lookups that 1691/// were not overloaded, and it doesn't promise that the declaration 1692/// will in fact be used. 1693static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1694 if (isa<TypedefDecl>(D)) { 1695 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1696 return true; 1697 } 1698 1699 if (isa<ObjCInterfaceDecl>(D)) { 1700 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1701 return true; 1702 } 1703 1704 if (isa<NamespaceDecl>(D)) { 1705 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1706 return true; 1707 } 1708 1709 return false; 1710} 1711 1712Sema::OwningExprResult 1713Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1714 LookupResult &R, 1715 bool NeedsADL) { 1716 // If this is a single, fully-resolved result and we don't need ADL, 1717 // just build an ordinary singleton decl ref. 1718 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1719 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), 1720 R.getFoundDecl()); 1721 1722 // We only need to check the declaration if there's exactly one 1723 // result, because in the overloaded case the results can only be 1724 // functions and function templates. 1725 if (R.isSingleResult() && 1726 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1727 return ExprError(); 1728 1729 // Otherwise, just build an unresolved lookup expression. Suppress 1730 // any lookup-related diagnostics; we'll hash these out later, when 1731 // we've picked a target. 1732 R.suppressDiagnostics(); 1733 1734 bool Dependent 1735 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1736 UnresolvedLookupExpr *ULE 1737 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1738 (NestedNameSpecifier*) SS.getScopeRep(), 1739 SS.getRange(), R.getLookupNameInfo(), 1740 NeedsADL, R.isOverloadedResult(), 1741 R.begin(), R.end()); 1742 1743 return Owned(ULE); 1744} 1745 1746 1747/// \brief Complete semantic analysis for a reference to the given declaration. 1748Sema::OwningExprResult 1749Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1750 const DeclarationNameInfo &NameInfo, 1751 NamedDecl *D) { 1752 assert(D && "Cannot refer to a NULL declaration"); 1753 assert(!isa<FunctionTemplateDecl>(D) && 1754 "Cannot refer unambiguously to a function template"); 1755 1756 SourceLocation Loc = NameInfo.getLoc(); 1757 if (CheckDeclInExpr(*this, Loc, D)) 1758 return ExprError(); 1759 1760 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1761 // Specifically diagnose references to class templates that are missing 1762 // a template argument list. 1763 Diag(Loc, diag::err_template_decl_ref) 1764 << Template << SS.getRange(); 1765 Diag(Template->getLocation(), diag::note_template_decl_here); 1766 return ExprError(); 1767 } 1768 1769 // Make sure that we're referring to a value. 1770 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1771 if (!VD) { 1772 Diag(Loc, diag::err_ref_non_value) 1773 << D << SS.getRange(); 1774 Diag(D->getLocation(), diag::note_declared_at); 1775 return ExprError(); 1776 } 1777 1778 // Check whether this declaration can be used. Note that we suppress 1779 // this check when we're going to perform argument-dependent lookup 1780 // on this function name, because this might not be the function 1781 // that overload resolution actually selects. 1782 if (DiagnoseUseOfDecl(VD, Loc)) 1783 return ExprError(); 1784 1785 // Only create DeclRefExpr's for valid Decl's. 1786 if (VD->isInvalidDecl()) 1787 return ExprError(); 1788 1789 // If the identifier reference is inside a block, and it refers to a value 1790 // that is outside the block, create a BlockDeclRefExpr instead of a 1791 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1792 // the block is formed. 1793 // 1794 // We do not do this for things like enum constants, global variables, etc, 1795 // as they do not get snapshotted. 1796 // 1797 if (getCurBlock() && 1798 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1799 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1800 Diag(Loc, diag::err_ref_vm_type); 1801 Diag(D->getLocation(), diag::note_declared_at); 1802 return ExprError(); 1803 } 1804 1805 if (VD->getType()->isArrayType()) { 1806 Diag(Loc, diag::err_ref_array_type); 1807 Diag(D->getLocation(), diag::note_declared_at); 1808 return ExprError(); 1809 } 1810 1811 MarkDeclarationReferenced(Loc, VD); 1812 QualType ExprTy = VD->getType().getNonReferenceType(); 1813 // The BlocksAttr indicates the variable is bound by-reference. 1814 if (VD->getAttr<BlocksAttr>()) 1815 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1816 // This is to record that a 'const' was actually synthesize and added. 1817 bool constAdded = !ExprTy.isConstQualified(); 1818 // Variable will be bound by-copy, make it const within the closure. 1819 1820 ExprTy.addConst(); 1821 QualType T = VD->getType(); 1822 BlockDeclRefExpr *BDRE = new (Context) BlockDeclRefExpr(VD, 1823 ExprTy, Loc, false, 1824 constAdded); 1825 if (getLangOptions().CPlusPlus) { 1826 if (!T->isDependentType() && !T->isReferenceType()) { 1827 Expr *E = new (Context) 1828 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 1829 SourceLocation()); 1830 1831 OwningExprResult Res = PerformCopyInitialization( 1832 InitializedEntity::InitializeBlock(VD->getLocation(), 1833 T, false), 1834 SourceLocation(), 1835 Owned(E)); 1836 if (!Res.isInvalid()) { 1837 Res = MaybeCreateCXXExprWithTemporaries(Res.get()); 1838 Expr *Init = Res.takeAs<Expr>(); 1839 BDRE->setCopyConstructorExpr(Init); 1840 } 1841 } 1842 } 1843 return Owned(BDRE); 1844 } 1845 // If this reference is not in a block or if the referenced variable is 1846 // within the block, create a normal DeclRefExpr. 1847 1848 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), 1849 NameInfo, &SS); 1850} 1851 1852Sema::OwningExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1853 tok::TokenKind Kind) { 1854 PredefinedExpr::IdentType IT; 1855 1856 switch (Kind) { 1857 default: assert(0 && "Unknown simple primary expr!"); 1858 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1859 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1860 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1861 } 1862 1863 // Pre-defined identifiers are of type char[x], where x is the length of the 1864 // string. 1865 1866 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1867 if (!currentDecl && getCurBlock()) 1868 currentDecl = getCurBlock()->TheDecl; 1869 if (!currentDecl) { 1870 Diag(Loc, diag::ext_predef_outside_function); 1871 currentDecl = Context.getTranslationUnitDecl(); 1872 } 1873 1874 QualType ResTy; 1875 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1876 ResTy = Context.DependentTy; 1877 } else { 1878 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1879 1880 llvm::APInt LengthI(32, Length + 1); 1881 ResTy = Context.CharTy.withConst(); 1882 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1883 } 1884 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1885} 1886 1887Sema::OwningExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1888 llvm::SmallString<16> CharBuffer; 1889 bool Invalid = false; 1890 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1891 if (Invalid) 1892 return ExprError(); 1893 1894 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1895 PP); 1896 if (Literal.hadError()) 1897 return ExprError(); 1898 1899 QualType Ty; 1900 if (!getLangOptions().CPlusPlus) 1901 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1902 else if (Literal.isWide()) 1903 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1904 else if (Literal.isMultiChar()) 1905 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1906 else 1907 Ty = Context.CharTy; // 'x' -> char in C++ 1908 1909 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1910 Literal.isWide(), 1911 Ty, Tok.getLocation())); 1912} 1913 1914Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1915 // Fast path for a single digit (which is quite common). A single digit 1916 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1917 if (Tok.getLength() == 1) { 1918 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1919 unsigned IntSize = Context.Target.getIntWidth(); 1920 return Owned(new (Context) IntegerLiteral(llvm::APInt(IntSize, Val-'0'), 1921 Context.IntTy, Tok.getLocation())); 1922 } 1923 1924 llvm::SmallString<512> IntegerBuffer; 1925 // Add padding so that NumericLiteralParser can overread by one character. 1926 IntegerBuffer.resize(Tok.getLength()+1); 1927 const char *ThisTokBegin = &IntegerBuffer[0]; 1928 1929 // Get the spelling of the token, which eliminates trigraphs, etc. 1930 bool Invalid = false; 1931 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1932 if (Invalid) 1933 return ExprError(); 1934 1935 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1936 Tok.getLocation(), PP); 1937 if (Literal.hadError) 1938 return ExprError(); 1939 1940 Expr *Res; 1941 1942 if (Literal.isFloatingLiteral()) { 1943 QualType Ty; 1944 if (Literal.isFloat) 1945 Ty = Context.FloatTy; 1946 else if (!Literal.isLong) 1947 Ty = Context.DoubleTy; 1948 else 1949 Ty = Context.LongDoubleTy; 1950 1951 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1952 1953 using llvm::APFloat; 1954 APFloat Val(Format); 1955 1956 APFloat::opStatus result = Literal.GetFloatValue(Val); 1957 1958 // Overflow is always an error, but underflow is only an error if 1959 // we underflowed to zero (APFloat reports denormals as underflow). 1960 if ((result & APFloat::opOverflow) || 1961 ((result & APFloat::opUnderflow) && Val.isZero())) { 1962 unsigned diagnostic; 1963 llvm::SmallString<20> buffer; 1964 if (result & APFloat::opOverflow) { 1965 diagnostic = diag::warn_float_overflow; 1966 APFloat::getLargest(Format).toString(buffer); 1967 } else { 1968 diagnostic = diag::warn_float_underflow; 1969 APFloat::getSmallest(Format).toString(buffer); 1970 } 1971 1972 Diag(Tok.getLocation(), diagnostic) 1973 << Ty 1974 << llvm::StringRef(buffer.data(), buffer.size()); 1975 } 1976 1977 bool isExact = (result == APFloat::opOK); 1978 Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation()); 1979 1980 } else if (!Literal.isIntegerLiteral()) { 1981 return ExprError(); 1982 } else { 1983 QualType Ty; 1984 1985 // long long is a C99 feature. 1986 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 1987 Literal.isLongLong) 1988 Diag(Tok.getLocation(), diag::ext_longlong); 1989 1990 // Get the value in the widest-possible width. 1991 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 1992 1993 if (Literal.GetIntegerValue(ResultVal)) { 1994 // If this value didn't fit into uintmax_t, warn and force to ull. 1995 Diag(Tok.getLocation(), diag::warn_integer_too_large); 1996 Ty = Context.UnsignedLongLongTy; 1997 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 1998 "long long is not intmax_t?"); 1999 } else { 2000 // If this value fits into a ULL, try to figure out what else it fits into 2001 // according to the rules of C99 6.4.4.1p5. 2002 2003 // Octal, Hexadecimal, and integers with a U suffix are allowed to 2004 // be an unsigned int. 2005 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 2006 2007 // Check from smallest to largest, picking the smallest type we can. 2008 unsigned Width = 0; 2009 if (!Literal.isLong && !Literal.isLongLong) { 2010 // Are int/unsigned possibilities? 2011 unsigned IntSize = Context.Target.getIntWidth(); 2012 2013 // Does it fit in a unsigned int? 2014 if (ResultVal.isIntN(IntSize)) { 2015 // Does it fit in a signed int? 2016 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 2017 Ty = Context.IntTy; 2018 else if (AllowUnsigned) 2019 Ty = Context.UnsignedIntTy; 2020 Width = IntSize; 2021 } 2022 } 2023 2024 // Are long/unsigned long possibilities? 2025 if (Ty.isNull() && !Literal.isLongLong) { 2026 unsigned LongSize = Context.Target.getLongWidth(); 2027 2028 // Does it fit in a unsigned long? 2029 if (ResultVal.isIntN(LongSize)) { 2030 // Does it fit in a signed long? 2031 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 2032 Ty = Context.LongTy; 2033 else if (AllowUnsigned) 2034 Ty = Context.UnsignedLongTy; 2035 Width = LongSize; 2036 } 2037 } 2038 2039 // Finally, check long long if needed. 2040 if (Ty.isNull()) { 2041 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2042 2043 // Does it fit in a unsigned long long? 2044 if (ResultVal.isIntN(LongLongSize)) { 2045 // Does it fit in a signed long long? 2046 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 2047 Ty = Context.LongLongTy; 2048 else if (AllowUnsigned) 2049 Ty = Context.UnsignedLongLongTy; 2050 Width = LongLongSize; 2051 } 2052 } 2053 2054 // If we still couldn't decide a type, we probably have something that 2055 // does not fit in a signed long long, but has no U suffix. 2056 if (Ty.isNull()) { 2057 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2058 Ty = Context.UnsignedLongLongTy; 2059 Width = Context.Target.getLongLongWidth(); 2060 } 2061 2062 if (ResultVal.getBitWidth() != Width) 2063 ResultVal.trunc(Width); 2064 } 2065 Res = new (Context) IntegerLiteral(ResultVal, Ty, Tok.getLocation()); 2066 } 2067 2068 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2069 if (Literal.isImaginary) 2070 Res = new (Context) ImaginaryLiteral(Res, 2071 Context.getComplexType(Res->getType())); 2072 2073 return Owned(Res); 2074} 2075 2076Action::OwningExprResult Sema::ActOnParenExpr(SourceLocation L, 2077 SourceLocation R, Expr *E) { 2078 assert((E != 0) && "ActOnParenExpr() missing expr"); 2079 return Owned(new (Context) ParenExpr(L, R, E)); 2080} 2081 2082/// The UsualUnaryConversions() function is *not* called by this routine. 2083/// See C99 6.3.2.1p[2-4] for more details. 2084bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2085 SourceLocation OpLoc, 2086 const SourceRange &ExprRange, 2087 bool isSizeof) { 2088 if (exprType->isDependentType()) 2089 return false; 2090 2091 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2092 // the result is the size of the referenced type." 2093 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2094 // result shall be the alignment of the referenced type." 2095 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2096 exprType = Ref->getPointeeType(); 2097 2098 // C99 6.5.3.4p1: 2099 if (exprType->isFunctionType()) { 2100 // alignof(function) is allowed as an extension. 2101 if (isSizeof) 2102 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2103 return false; 2104 } 2105 2106 // Allow sizeof(void)/alignof(void) as an extension. 2107 if (exprType->isVoidType()) { 2108 Diag(OpLoc, diag::ext_sizeof_void_type) 2109 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2110 return false; 2111 } 2112 2113 if (RequireCompleteType(OpLoc, exprType, 2114 PDiag(diag::err_sizeof_alignof_incomplete_type) 2115 << int(!isSizeof) << ExprRange)) 2116 return true; 2117 2118 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2119 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2120 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2121 << exprType << isSizeof << ExprRange; 2122 return true; 2123 } 2124 2125 if (Context.hasSameUnqualifiedType(exprType, Context.OverloadTy)) { 2126 Diag(OpLoc, diag::err_sizeof_alignof_overloaded_function_type) 2127 << !isSizeof << ExprRange; 2128 return true; 2129 } 2130 2131 return false; 2132} 2133 2134bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2135 const SourceRange &ExprRange) { 2136 E = E->IgnoreParens(); 2137 2138 // alignof decl is always ok. 2139 if (isa<DeclRefExpr>(E)) 2140 return false; 2141 2142 // Cannot know anything else if the expression is dependent. 2143 if (E->isTypeDependent()) 2144 return false; 2145 2146 if (E->getBitField()) { 2147 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2148 return true; 2149 } 2150 2151 // Alignment of a field access is always okay, so long as it isn't a 2152 // bit-field. 2153 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2154 if (isa<FieldDecl>(ME->getMemberDecl())) 2155 return false; 2156 2157 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2158} 2159 2160/// \brief Build a sizeof or alignof expression given a type operand. 2161Action::OwningExprResult 2162Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2163 SourceLocation OpLoc, 2164 bool isSizeOf, SourceRange R) { 2165 if (!TInfo) 2166 return ExprError(); 2167 2168 QualType T = TInfo->getType(); 2169 2170 if (!T->isDependentType() && 2171 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2172 return ExprError(); 2173 2174 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2175 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2176 Context.getSizeType(), OpLoc, 2177 R.getEnd())); 2178} 2179 2180/// \brief Build a sizeof or alignof expression given an expression 2181/// operand. 2182Action::OwningExprResult 2183Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2184 bool isSizeOf, SourceRange R) { 2185 // Verify that the operand is valid. 2186 bool isInvalid = false; 2187 if (E->isTypeDependent()) { 2188 // Delay type-checking for type-dependent expressions. 2189 } else if (!isSizeOf) { 2190 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2191 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2192 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2193 isInvalid = true; 2194 } else { 2195 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2196 } 2197 2198 if (isInvalid) 2199 return ExprError(); 2200 2201 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2202 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2203 Context.getSizeType(), OpLoc, 2204 R.getEnd())); 2205} 2206 2207/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2208/// the same for @c alignof and @c __alignof 2209/// Note that the ArgRange is invalid if isType is false. 2210Action::OwningExprResult 2211Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2212 void *TyOrEx, const SourceRange &ArgRange) { 2213 // If error parsing type, ignore. 2214 if (TyOrEx == 0) return ExprError(); 2215 2216 if (isType) { 2217 TypeSourceInfo *TInfo; 2218 (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); 2219 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2220 } 2221 2222 Expr *ArgEx = (Expr *)TyOrEx; 2223 Action::OwningExprResult Result 2224 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2225 2226 if (Result.isInvalid()) 2227 DeleteExpr(ArgEx); 2228 2229 return move(Result); 2230} 2231 2232QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2233 if (V->isTypeDependent()) 2234 return Context.DependentTy; 2235 2236 // These operators return the element type of a complex type. 2237 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2238 return CT->getElementType(); 2239 2240 // Otherwise they pass through real integer and floating point types here. 2241 if (V->getType()->isArithmeticType()) 2242 return V->getType(); 2243 2244 // Reject anything else. 2245 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2246 << (isReal ? "__real" : "__imag"); 2247 return QualType(); 2248} 2249 2250 2251 2252Action::OwningExprResult 2253Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2254 tok::TokenKind Kind, Expr *Input) { 2255 UnaryOperator::Opcode Opc; 2256 switch (Kind) { 2257 default: assert(0 && "Unknown unary op!"); 2258 case tok::plusplus: Opc = UnaryOperator::PostInc; break; 2259 case tok::minusminus: Opc = UnaryOperator::PostDec; break; 2260 } 2261 2262 return BuildUnaryOp(S, OpLoc, Opc, Input); 2263} 2264 2265Action::OwningExprResult 2266Sema::ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc, 2267 Expr *Idx, SourceLocation RLoc) { 2268 // Since this might be a postfix expression, get rid of ParenListExprs. 2269 OwningExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 2270 if (Result.isInvalid()) return ExprError(); 2271 Base = Result.take(); 2272 2273 Expr *LHSExp = Base, *RHSExp = Idx; 2274 2275 if (getLangOptions().CPlusPlus && 2276 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2277 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2278 Context.DependentTy, RLoc)); 2279 } 2280 2281 if (getLangOptions().CPlusPlus && 2282 (LHSExp->getType()->isRecordType() || 2283 LHSExp->getType()->isEnumeralType() || 2284 RHSExp->getType()->isRecordType() || 2285 RHSExp->getType()->isEnumeralType())) { 2286 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, Base, Idx); 2287 } 2288 2289 return CreateBuiltinArraySubscriptExpr(Base, LLoc, Idx, RLoc); 2290} 2291 2292 2293Action::OwningExprResult 2294Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, 2295 Expr *Idx, SourceLocation RLoc) { 2296 Expr *LHSExp = Base; 2297 Expr *RHSExp = Idx; 2298 2299 // Perform default conversions. 2300 if (!LHSExp->getType()->getAs<VectorType>()) 2301 DefaultFunctionArrayLvalueConversion(LHSExp); 2302 DefaultFunctionArrayLvalueConversion(RHSExp); 2303 2304 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2305 2306 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2307 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2308 // in the subscript position. As a result, we need to derive the array base 2309 // and index from the expression types. 2310 Expr *BaseExpr, *IndexExpr; 2311 QualType ResultType; 2312 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2313 BaseExpr = LHSExp; 2314 IndexExpr = RHSExp; 2315 ResultType = Context.DependentTy; 2316 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2317 BaseExpr = LHSExp; 2318 IndexExpr = RHSExp; 2319 ResultType = PTy->getPointeeType(); 2320 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2321 // Handle the uncommon case of "123[Ptr]". 2322 BaseExpr = RHSExp; 2323 IndexExpr = LHSExp; 2324 ResultType = PTy->getPointeeType(); 2325 } else if (const ObjCObjectPointerType *PTy = 2326 LHSTy->getAs<ObjCObjectPointerType>()) { 2327 BaseExpr = LHSExp; 2328 IndexExpr = RHSExp; 2329 ResultType = PTy->getPointeeType(); 2330 } else if (const ObjCObjectPointerType *PTy = 2331 RHSTy->getAs<ObjCObjectPointerType>()) { 2332 // Handle the uncommon case of "123[Ptr]". 2333 BaseExpr = RHSExp; 2334 IndexExpr = LHSExp; 2335 ResultType = PTy->getPointeeType(); 2336 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2337 BaseExpr = LHSExp; // vectors: V[123] 2338 IndexExpr = RHSExp; 2339 2340 // FIXME: need to deal with const... 2341 ResultType = VTy->getElementType(); 2342 } else if (LHSTy->isArrayType()) { 2343 // If we see an array that wasn't promoted by 2344 // DefaultFunctionArrayLvalueConversion, it must be an array that 2345 // wasn't promoted because of the C90 rule that doesn't 2346 // allow promoting non-lvalue arrays. Warn, then 2347 // force the promotion here. 2348 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2349 LHSExp->getSourceRange(); 2350 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2351 CastExpr::CK_ArrayToPointerDecay); 2352 LHSTy = LHSExp->getType(); 2353 2354 BaseExpr = LHSExp; 2355 IndexExpr = RHSExp; 2356 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2357 } else if (RHSTy->isArrayType()) { 2358 // Same as previous, except for 123[f().a] case 2359 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2360 RHSExp->getSourceRange(); 2361 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2362 CastExpr::CK_ArrayToPointerDecay); 2363 RHSTy = RHSExp->getType(); 2364 2365 BaseExpr = RHSExp; 2366 IndexExpr = LHSExp; 2367 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2368 } else { 2369 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2370 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2371 } 2372 // C99 6.5.2.1p1 2373 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) 2374 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2375 << IndexExpr->getSourceRange()); 2376 2377 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2378 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2379 && !IndexExpr->isTypeDependent()) 2380 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2381 2382 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2383 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2384 // type. Note that Functions are not objects, and that (in C99 parlance) 2385 // incomplete types are not object types. 2386 if (ResultType->isFunctionType()) { 2387 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2388 << ResultType << BaseExpr->getSourceRange(); 2389 return ExprError(); 2390 } 2391 2392 if (!ResultType->isDependentType() && 2393 RequireCompleteType(LLoc, ResultType, 2394 PDiag(diag::err_subscript_incomplete_type) 2395 << BaseExpr->getSourceRange())) 2396 return ExprError(); 2397 2398 // Diagnose bad cases where we step over interface counts. 2399 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2400 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2401 << ResultType << BaseExpr->getSourceRange(); 2402 return ExprError(); 2403 } 2404 2405 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2406 ResultType, RLoc)); 2407} 2408 2409QualType Sema:: 2410CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2411 const IdentifierInfo *CompName, 2412 SourceLocation CompLoc) { 2413 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2414 // see FIXME there. 2415 // 2416 // FIXME: This logic can be greatly simplified by splitting it along 2417 // halving/not halving and reworking the component checking. 2418 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2419 2420 // The vector accessor can't exceed the number of elements. 2421 const char *compStr = CompName->getNameStart(); 2422 2423 // This flag determines whether or not the component is one of the four 2424 // special names that indicate a subset of exactly half the elements are 2425 // to be selected. 2426 bool HalvingSwizzle = false; 2427 2428 // This flag determines whether or not CompName has an 's' char prefix, 2429 // indicating that it is a string of hex values to be used as vector indices. 2430 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2431 2432 // Check that we've found one of the special components, or that the component 2433 // names must come from the same set. 2434 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2435 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2436 HalvingSwizzle = true; 2437 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2438 do 2439 compStr++; 2440 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2441 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2442 do 2443 compStr++; 2444 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2445 } 2446 2447 if (!HalvingSwizzle && *compStr) { 2448 // We didn't get to the end of the string. This means the component names 2449 // didn't come from the same set *or* we encountered an illegal name. 2450 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2451 << llvm::StringRef(compStr, 1) << SourceRange(CompLoc); 2452 return QualType(); 2453 } 2454 2455 // Ensure no component accessor exceeds the width of the vector type it 2456 // operates on. 2457 if (!HalvingSwizzle) { 2458 compStr = CompName->getNameStart(); 2459 2460 if (HexSwizzle) 2461 compStr++; 2462 2463 while (*compStr) { 2464 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2465 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2466 << baseType << SourceRange(CompLoc); 2467 return QualType(); 2468 } 2469 } 2470 } 2471 2472 // The component accessor looks fine - now we need to compute the actual type. 2473 // The vector type is implied by the component accessor. For example, 2474 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2475 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2476 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2477 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2478 : CompName->getLength(); 2479 if (HexSwizzle) 2480 CompSize--; 2481 2482 if (CompSize == 1) 2483 return vecType->getElementType(); 2484 2485 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2486 // Now look up the TypeDefDecl from the vector type. Without this, 2487 // diagostics look bad. We want extended vector types to appear built-in. 2488 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2489 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2490 return Context.getTypedefType(ExtVectorDecls[i]); 2491 } 2492 return VT; // should never get here (a typedef type should always be found). 2493} 2494 2495static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2496 IdentifierInfo *Member, 2497 const Selector &Sel, 2498 ASTContext &Context) { 2499 2500 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2501 return PD; 2502 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2503 return OMD; 2504 2505 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2506 E = PDecl->protocol_end(); I != E; ++I) { 2507 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2508 Context)) 2509 return D; 2510 } 2511 return 0; 2512} 2513 2514static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2515 IdentifierInfo *Member, 2516 const Selector &Sel, 2517 ASTContext &Context) { 2518 // Check protocols on qualified interfaces. 2519 Decl *GDecl = 0; 2520 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2521 E = QIdTy->qual_end(); I != E; ++I) { 2522 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2523 GDecl = PD; 2524 break; 2525 } 2526 // Also must look for a getter name which uses property syntax. 2527 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2528 GDecl = OMD; 2529 break; 2530 } 2531 } 2532 if (!GDecl) { 2533 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2534 E = QIdTy->qual_end(); I != E; ++I) { 2535 // Search in the protocol-qualifier list of current protocol. 2536 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2537 if (GDecl) 2538 return GDecl; 2539 } 2540 } 2541 return GDecl; 2542} 2543 2544Sema::OwningExprResult 2545Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, 2546 bool IsArrow, SourceLocation OpLoc, 2547 const CXXScopeSpec &SS, 2548 NamedDecl *FirstQualifierInScope, 2549 const DeclarationNameInfo &NameInfo, 2550 const TemplateArgumentListInfo *TemplateArgs) { 2551 // Even in dependent contexts, try to diagnose base expressions with 2552 // obviously wrong types, e.g.: 2553 // 2554 // T* t; 2555 // t.f; 2556 // 2557 // In Obj-C++, however, the above expression is valid, since it could be 2558 // accessing the 'f' property if T is an Obj-C interface. The extra check 2559 // allows this, while still reporting an error if T is a struct pointer. 2560 if (!IsArrow) { 2561 const PointerType *PT = BaseType->getAs<PointerType>(); 2562 if (PT && (!getLangOptions().ObjC1 || 2563 PT->getPointeeType()->isRecordType())) { 2564 assert(BaseExpr && "cannot happen with implicit member accesses"); 2565 Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) 2566 << BaseType << BaseExpr->getSourceRange(); 2567 return ExprError(); 2568 } 2569 } 2570 2571 assert(BaseType->isDependentType() || 2572 NameInfo.getName().isDependentName() || 2573 isDependentScopeSpecifier(SS)); 2574 2575 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2576 // must have pointer type, and the accessed type is the pointee. 2577 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2578 IsArrow, OpLoc, 2579 SS.getScopeRep(), 2580 SS.getRange(), 2581 FirstQualifierInScope, 2582 NameInfo, TemplateArgs)); 2583} 2584 2585/// We know that the given qualified member reference points only to 2586/// declarations which do not belong to the static type of the base 2587/// expression. Diagnose the problem. 2588static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2589 Expr *BaseExpr, 2590 QualType BaseType, 2591 const CXXScopeSpec &SS, 2592 const LookupResult &R) { 2593 // If this is an implicit member access, use a different set of 2594 // diagnostics. 2595 if (!BaseExpr) 2596 return DiagnoseInstanceReference(SemaRef, SS, R); 2597 2598 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 2599 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 2600} 2601 2602// Check whether the declarations we found through a nested-name 2603// specifier in a member expression are actually members of the base 2604// type. The restriction here is: 2605// 2606// C++ [expr.ref]p2: 2607// ... In these cases, the id-expression shall name a 2608// member of the class or of one of its base classes. 2609// 2610// So it's perfectly legitimate for the nested-name specifier to name 2611// an unrelated class, and for us to find an overload set including 2612// decls from classes which are not superclasses, as long as the decl 2613// we actually pick through overload resolution is from a superclass. 2614bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2615 QualType BaseType, 2616 const CXXScopeSpec &SS, 2617 const LookupResult &R) { 2618 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2619 if (!BaseRT) { 2620 // We can't check this yet because the base type is still 2621 // dependent. 2622 assert(BaseType->isDependentType()); 2623 return false; 2624 } 2625 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2626 2627 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2628 // If this is an implicit member reference and we find a 2629 // non-instance member, it's not an error. 2630 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2631 return false; 2632 2633 // Note that we use the DC of the decl, not the underlying decl. 2634 DeclContext *DC = (*I)->getDeclContext(); 2635 while (DC->isTransparentContext()) 2636 DC = DC->getParent(); 2637 2638 if (!DC->isRecord()) 2639 continue; 2640 2641 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2642 MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); 2643 2644 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2645 return false; 2646 } 2647 2648 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2649 return true; 2650} 2651 2652static bool 2653LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2654 SourceRange BaseRange, const RecordType *RTy, 2655 SourceLocation OpLoc, CXXScopeSpec &SS, 2656 bool HasTemplateArgs) { 2657 RecordDecl *RDecl = RTy->getDecl(); 2658 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2659 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2660 << BaseRange)) 2661 return true; 2662 2663 if (HasTemplateArgs) { 2664 // LookupTemplateName doesn't expect these both to exist simultaneously. 2665 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 2666 2667 bool MOUS; 2668 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 2669 return false; 2670 } 2671 2672 DeclContext *DC = RDecl; 2673 if (SS.isSet()) { 2674 // If the member name was a qualified-id, look into the 2675 // nested-name-specifier. 2676 DC = SemaRef.computeDeclContext(SS, false); 2677 2678 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 2679 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2680 << SS.getRange() << DC; 2681 return true; 2682 } 2683 2684 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2685 2686 if (!isa<TypeDecl>(DC)) { 2687 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2688 << DC << SS.getRange(); 2689 return true; 2690 } 2691 } 2692 2693 // The record definition is complete, now look up the member. 2694 SemaRef.LookupQualifiedName(R, DC); 2695 2696 if (!R.empty()) 2697 return false; 2698 2699 // We didn't find anything with the given name, so try to correct 2700 // for typos. 2701 DeclarationName Name = R.getLookupName(); 2702 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 2703 !R.empty() && 2704 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2705 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2706 << Name << DC << R.getLookupName() << SS.getRange() 2707 << FixItHint::CreateReplacement(R.getNameLoc(), 2708 R.getLookupName().getAsString()); 2709 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2710 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2711 << ND->getDeclName(); 2712 return false; 2713 } else { 2714 R.clear(); 2715 R.setLookupName(Name); 2716 } 2717 2718 return false; 2719} 2720 2721Sema::OwningExprResult 2722Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, 2723 SourceLocation OpLoc, bool IsArrow, 2724 CXXScopeSpec &SS, 2725 NamedDecl *FirstQualifierInScope, 2726 const DeclarationNameInfo &NameInfo, 2727 const TemplateArgumentListInfo *TemplateArgs) { 2728 if (BaseType->isDependentType() || 2729 (SS.isSet() && isDependentScopeSpecifier(SS))) 2730 return ActOnDependentMemberExpr(Base, BaseType, 2731 IsArrow, OpLoc, 2732 SS, FirstQualifierInScope, 2733 NameInfo, TemplateArgs); 2734 2735 LookupResult R(*this, NameInfo, LookupMemberName); 2736 2737 // Implicit member accesses. 2738 if (!Base) { 2739 QualType RecordTy = BaseType; 2740 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2741 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2742 RecordTy->getAs<RecordType>(), 2743 OpLoc, SS, TemplateArgs != 0)) 2744 return ExprError(); 2745 2746 // Explicit member accesses. 2747 } else { 2748 OwningExprResult Result = 2749 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2750 SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); 2751 2752 if (Result.isInvalid()) { 2753 Owned(Base); 2754 return ExprError(); 2755 } 2756 2757 if (Result.get()) 2758 return move(Result); 2759 2760 // LookupMemberExpr can modify Base, and thus change BaseType 2761 BaseType = Base->getType(); 2762 } 2763 2764 return BuildMemberReferenceExpr(Base, BaseType, 2765 OpLoc, IsArrow, SS, FirstQualifierInScope, 2766 R, TemplateArgs); 2767} 2768 2769Sema::OwningExprResult 2770Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, 2771 SourceLocation OpLoc, bool IsArrow, 2772 const CXXScopeSpec &SS, 2773 NamedDecl *FirstQualifierInScope, 2774 LookupResult &R, 2775 const TemplateArgumentListInfo *TemplateArgs, 2776 bool SuppressQualifierCheck) { 2777 QualType BaseType = BaseExprType; 2778 if (IsArrow) { 2779 assert(BaseType->isPointerType()); 2780 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2781 } 2782 R.setBaseObjectType(BaseType); 2783 2784 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 2785 const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); 2786 DeclarationName MemberName = MemberNameInfo.getName(); 2787 SourceLocation MemberLoc = MemberNameInfo.getLoc(); 2788 2789 if (R.isAmbiguous()) 2790 return ExprError(); 2791 2792 if (R.empty()) { 2793 // Rederive where we looked up. 2794 DeclContext *DC = (SS.isSet() 2795 ? computeDeclContext(SS, false) 2796 : BaseType->getAs<RecordType>()->getDecl()); 2797 2798 Diag(R.getNameLoc(), diag::err_no_member) 2799 << MemberName << DC 2800 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2801 return ExprError(); 2802 } 2803 2804 // Diagnose lookups that find only declarations from a non-base 2805 // type. This is possible for either qualified lookups (which may 2806 // have been qualified with an unrelated type) or implicit member 2807 // expressions (which were found with unqualified lookup and thus 2808 // may have come from an enclosing scope). Note that it's okay for 2809 // lookup to find declarations from a non-base type as long as those 2810 // aren't the ones picked by overload resolution. 2811 if ((SS.isSet() || !BaseExpr || 2812 (isa<CXXThisExpr>(BaseExpr) && 2813 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2814 !SuppressQualifierCheck && 2815 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2816 return ExprError(); 2817 2818 // Construct an unresolved result if we in fact got an unresolved 2819 // result. 2820 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2821 bool Dependent = 2822 BaseExprType->isDependentType() || 2823 R.isUnresolvableResult() || 2824 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2825 2826 // Suppress any lookup-related diagnostics; we'll do these when we 2827 // pick a member. 2828 R.suppressDiagnostics(); 2829 2830 UnresolvedMemberExpr *MemExpr 2831 = UnresolvedMemberExpr::Create(Context, Dependent, 2832 R.isUnresolvableResult(), 2833 BaseExpr, BaseExprType, 2834 IsArrow, OpLoc, 2835 Qualifier, SS.getRange(), 2836 MemberNameInfo, 2837 TemplateArgs, R.begin(), R.end()); 2838 2839 return Owned(MemExpr); 2840 } 2841 2842 assert(R.isSingleResult()); 2843 DeclAccessPair FoundDecl = R.begin().getPair(); 2844 NamedDecl *MemberDecl = R.getFoundDecl(); 2845 2846 // FIXME: diagnose the presence of template arguments now. 2847 2848 // If the decl being referenced had an error, return an error for this 2849 // sub-expr without emitting another error, in order to avoid cascading 2850 // error cases. 2851 if (MemberDecl->isInvalidDecl()) 2852 return ExprError(); 2853 2854 // Handle the implicit-member-access case. 2855 if (!BaseExpr) { 2856 // If this is not an instance member, convert to a non-member access. 2857 if (!MemberDecl->isCXXInstanceMember()) 2858 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); 2859 2860 SourceLocation Loc = R.getNameLoc(); 2861 if (SS.getRange().isValid()) 2862 Loc = SS.getRange().getBegin(); 2863 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2864 } 2865 2866 bool ShouldCheckUse = true; 2867 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2868 // Don't diagnose the use of a virtual member function unless it's 2869 // explicitly qualified. 2870 if (MD->isVirtual() && !SS.isSet()) 2871 ShouldCheckUse = false; 2872 } 2873 2874 // Check the use of this member. 2875 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2876 Owned(BaseExpr); 2877 return ExprError(); 2878 } 2879 2880 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2881 // We may have found a field within an anonymous union or struct 2882 // (C++ [class.union]). 2883 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2884 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2885 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2886 BaseExpr, OpLoc); 2887 2888 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2889 QualType MemberType = FD->getType(); 2890 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2891 MemberType = Ref->getPointeeType(); 2892 else { 2893 Qualifiers BaseQuals = BaseType.getQualifiers(); 2894 BaseQuals.removeObjCGCAttr(); 2895 if (FD->isMutable()) BaseQuals.removeConst(); 2896 2897 Qualifiers MemberQuals 2898 = Context.getCanonicalType(MemberType).getQualifiers(); 2899 2900 Qualifiers Combined = BaseQuals + MemberQuals; 2901 if (Combined != MemberQuals) 2902 MemberType = Context.getQualifiedType(MemberType, Combined); 2903 } 2904 2905 MarkDeclarationReferenced(MemberLoc, FD); 2906 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2907 return ExprError(); 2908 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2909 FD, FoundDecl, MemberNameInfo, 2910 MemberType)); 2911 } 2912 2913 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2914 MarkDeclarationReferenced(MemberLoc, Var); 2915 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2916 Var, FoundDecl, MemberNameInfo, 2917 Var->getType().getNonReferenceType())); 2918 } 2919 2920 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2921 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2922 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2923 MemberFn, FoundDecl, MemberNameInfo, 2924 MemberFn->getType())); 2925 } 2926 2927 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2928 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2929 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2930 Enum, FoundDecl, MemberNameInfo, 2931 Enum->getType())); 2932 } 2933 2934 Owned(BaseExpr); 2935 2936 // We found something that we didn't expect. Complain. 2937 if (isa<TypeDecl>(MemberDecl)) 2938 Diag(MemberLoc, diag::err_typecheck_member_reference_type) 2939 << MemberName << BaseType << int(IsArrow); 2940 else 2941 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 2942 << MemberName << BaseType << int(IsArrow); 2943 2944 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 2945 << MemberName; 2946 R.suppressDiagnostics(); 2947 return ExprError(); 2948} 2949 2950/// Look up the given member of the given non-type-dependent 2951/// expression. This can return in one of two ways: 2952/// * If it returns a sentinel null-but-valid result, the caller will 2953/// assume that lookup was performed and the results written into 2954/// the provided structure. It will take over from there. 2955/// * Otherwise, the returned expression will be produced in place of 2956/// an ordinary member expression. 2957/// 2958/// The ObjCImpDecl bit is a gross hack that will need to be properly 2959/// fixed for ObjC++. 2960Sema::OwningExprResult 2961Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2962 bool &IsArrow, SourceLocation OpLoc, 2963 CXXScopeSpec &SS, 2964 Decl *ObjCImpDecl, bool HasTemplateArgs) { 2965 assert(BaseExpr && "no base expression"); 2966 2967 // Perform default conversions. 2968 DefaultFunctionArrayConversion(BaseExpr); 2969 2970 QualType BaseType = BaseExpr->getType(); 2971 assert(!BaseType->isDependentType()); 2972 2973 DeclarationName MemberName = R.getLookupName(); 2974 SourceLocation MemberLoc = R.getNameLoc(); 2975 2976 // If the user is trying to apply -> or . to a function pointer 2977 // type, it's probably because they forgot parentheses to call that 2978 // function. Suggest the addition of those parentheses, build the 2979 // call, and continue on. 2980 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 2981 if (const FunctionProtoType *Fun 2982 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 2983 QualType ResultTy = Fun->getResultType(); 2984 if (Fun->getNumArgs() == 0 && 2985 ((!IsArrow && ResultTy->isRecordType()) || 2986 (IsArrow && ResultTy->isPointerType() && 2987 ResultTy->getAs<PointerType>()->getPointeeType() 2988 ->isRecordType()))) { 2989 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 2990 Diag(Loc, diag::err_member_reference_needs_call) 2991 << QualType(Fun, 0) 2992 << FixItHint::CreateInsertion(Loc, "()"); 2993 2994 OwningExprResult NewBase 2995 = ActOnCallExpr(0, BaseExpr, Loc, 2996 MultiExprArg(*this, 0, 0), 0, Loc); 2997 BaseExpr = 0; 2998 if (NewBase.isInvalid()) 2999 return ExprError(); 3000 3001 BaseExpr = NewBase.takeAs<Expr>(); 3002 DefaultFunctionArrayConversion(BaseExpr); 3003 BaseType = BaseExpr->getType(); 3004 } 3005 } 3006 } 3007 3008 // If this is an Objective-C pseudo-builtin and a definition is provided then 3009 // use that. 3010 if (BaseType->isObjCIdType()) { 3011 if (IsArrow) { 3012 // Handle the following exceptional case PObj->isa. 3013 if (const ObjCObjectPointerType *OPT = 3014 BaseType->getAs<ObjCObjectPointerType>()) { 3015 if (OPT->getObjectType()->isObjCId() && 3016 MemberName.getAsIdentifierInfo()->isStr("isa")) 3017 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 3018 Context.getObjCClassType())); 3019 } 3020 } 3021 // We have an 'id' type. Rather than fall through, we check if this 3022 // is a reference to 'isa'. 3023 if (BaseType != Context.ObjCIdRedefinitionType) { 3024 BaseType = Context.ObjCIdRedefinitionType; 3025 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3026 } 3027 } 3028 3029 // If this is an Objective-C pseudo-builtin and a definition is provided then 3030 // use that. 3031 if (Context.isObjCSelType(BaseType)) { 3032 // We have an 'SEL' type. Rather than fall through, we check if this 3033 // is a reference to 'sel_id'. 3034 if (BaseType != Context.ObjCSelRedefinitionType) { 3035 BaseType = Context.ObjCSelRedefinitionType; 3036 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3037 } 3038 } 3039 3040 assert(!BaseType.isNull() && "no type for member expression"); 3041 3042 // Handle properties on ObjC 'Class' types. 3043 if (!IsArrow && BaseType->isObjCClassType()) { 3044 // Also must look for a getter name which uses property syntax. 3045 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3046 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3047 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 3048 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3049 ObjCMethodDecl *Getter; 3050 // FIXME: need to also look locally in the implementation. 3051 if ((Getter = IFace->lookupClassMethod(Sel))) { 3052 // Check the use of this method. 3053 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3054 return ExprError(); 3055 } 3056 // If we found a getter then this may be a valid dot-reference, we 3057 // will look for the matching setter, in case it is needed. 3058 Selector SetterSel = 3059 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3060 PP.getSelectorTable(), Member); 3061 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3062 if (!Setter) { 3063 // If this reference is in an @implementation, also check for 'private' 3064 // methods. 3065 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3066 } 3067 // Look through local category implementations associated with the class. 3068 if (!Setter) 3069 Setter = IFace->getCategoryClassMethod(SetterSel); 3070 3071 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3072 return ExprError(); 3073 3074 if (Getter || Setter) { 3075 QualType PType; 3076 3077 if (Getter) 3078 PType = Getter->getSendResultType(); 3079 else 3080 // Get the expression type from Setter's incoming parameter. 3081 PType = (*(Setter->param_end() -1))->getType(); 3082 // FIXME: we must check that the setter has property type. 3083 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 3084 PType, 3085 Setter, MemberLoc, BaseExpr)); 3086 } 3087 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3088 << MemberName << BaseType); 3089 } 3090 } 3091 3092 if (BaseType->isObjCClassType() && 3093 BaseType != Context.ObjCClassRedefinitionType) { 3094 BaseType = Context.ObjCClassRedefinitionType; 3095 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3096 } 3097 3098 if (IsArrow) { 3099 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3100 BaseType = PT->getPointeeType(); 3101 else if (BaseType->isObjCObjectPointerType()) 3102 ; 3103 else if (BaseType->isRecordType()) { 3104 // Recover from arrow accesses to records, e.g.: 3105 // struct MyRecord foo; 3106 // foo->bar 3107 // This is actually well-formed in C++ if MyRecord has an 3108 // overloaded operator->, but that should have been dealt with 3109 // by now. 3110 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3111 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3112 << FixItHint::CreateReplacement(OpLoc, "."); 3113 IsArrow = false; 3114 } else { 3115 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3116 << BaseType << BaseExpr->getSourceRange(); 3117 return ExprError(); 3118 } 3119 } else { 3120 // Recover from dot accesses to pointers, e.g.: 3121 // type *foo; 3122 // foo.bar 3123 // This is actually well-formed in two cases: 3124 // - 'type' is an Objective C type 3125 // - 'bar' is a pseudo-destructor name which happens to refer to 3126 // the appropriate pointer type 3127 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3128 const PointerType *PT = BaseType->getAs<PointerType>(); 3129 if (PT && PT->getPointeeType()->isRecordType()) { 3130 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3131 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3132 << FixItHint::CreateReplacement(OpLoc, "->"); 3133 BaseType = PT->getPointeeType(); 3134 IsArrow = true; 3135 } 3136 } 3137 } 3138 3139 // Handle field access to simple records. 3140 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3141 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3142 RTy, OpLoc, SS, HasTemplateArgs)) 3143 return ExprError(); 3144 return Owned((Expr*) 0); 3145 } 3146 3147 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3148 // (*Obj).ivar. 3149 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3150 (!IsArrow && BaseType->isObjCObjectType())) { 3151 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3152 ObjCInterfaceDecl *IDecl = 3153 OPT ? OPT->getInterfaceDecl() 3154 : BaseType->getAs<ObjCObjectType>()->getInterface(); 3155 if (IDecl) { 3156 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3157 3158 ObjCInterfaceDecl *ClassDeclared; 3159 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3160 3161 if (!IV) { 3162 // Attempt to correct for typos in ivar names. 3163 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3164 LookupMemberName); 3165 if (CorrectTypo(Res, 0, 0, IDecl, false, CTC_MemberLookup) && 3166 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3167 Diag(R.getNameLoc(), 3168 diag::err_typecheck_member_reference_ivar_suggest) 3169 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3170 << FixItHint::CreateReplacement(R.getNameLoc(), 3171 IV->getNameAsString()); 3172 Diag(IV->getLocation(), diag::note_previous_decl) 3173 << IV->getDeclName(); 3174 } else { 3175 Res.clear(); 3176 Res.setLookupName(Member); 3177 } 3178 } 3179 3180 if (IV) { 3181 // If the decl being referenced had an error, return an error for this 3182 // sub-expr without emitting another error, in order to avoid cascading 3183 // error cases. 3184 if (IV->isInvalidDecl()) 3185 return ExprError(); 3186 3187 // Check whether we can reference this field. 3188 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3189 return ExprError(); 3190 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3191 IV->getAccessControl() != ObjCIvarDecl::Package) { 3192 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3193 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3194 ClassOfMethodDecl = MD->getClassInterface(); 3195 else if (ObjCImpDecl && getCurFunctionDecl()) { 3196 // Case of a c-function declared inside an objc implementation. 3197 // FIXME: For a c-style function nested inside an objc implementation 3198 // class, there is no implementation context available, so we pass 3199 // down the context as argument to this routine. Ideally, this context 3200 // need be passed down in the AST node and somehow calculated from the 3201 // AST for a function decl. 3202 if (ObjCImplementationDecl *IMPD = 3203 dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) 3204 ClassOfMethodDecl = IMPD->getClassInterface(); 3205 else if (ObjCCategoryImplDecl* CatImplClass = 3206 dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) 3207 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3208 } 3209 3210 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3211 if (ClassDeclared != IDecl || 3212 ClassOfMethodDecl != ClassDeclared) 3213 Diag(MemberLoc, diag::error_private_ivar_access) 3214 << IV->getDeclName(); 3215 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3216 // @protected 3217 Diag(MemberLoc, diag::error_protected_ivar_access) 3218 << IV->getDeclName(); 3219 } 3220 3221 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3222 MemberLoc, BaseExpr, 3223 IsArrow)); 3224 } 3225 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3226 << IDecl->getDeclName() << MemberName 3227 << BaseExpr->getSourceRange()); 3228 } 3229 } 3230 // Handle properties on 'id' and qualified "id". 3231 if (!IsArrow && (BaseType->isObjCIdType() || 3232 BaseType->isObjCQualifiedIdType())) { 3233 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3234 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3235 3236 // Check protocols on qualified interfaces. 3237 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3238 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3239 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3240 // Check the use of this declaration 3241 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3242 return ExprError(); 3243 3244 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3245 MemberLoc, BaseExpr)); 3246 } 3247 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3248 // Check the use of this method. 3249 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3250 return ExprError(); 3251 3252 return Owned(ObjCMessageExpr::Create(Context, 3253 OMD->getSendResultType(), 3254 OpLoc, BaseExpr, Sel, 3255 OMD, NULL, 0, MemberLoc)); 3256 } 3257 } 3258 3259 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3260 << MemberName << BaseType); 3261 } 3262 3263 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3264 // pointer to a (potentially qualified) interface type. 3265 if (!IsArrow) 3266 if (const ObjCObjectPointerType *OPT = 3267 BaseType->getAsObjCInterfacePointerType()) 3268 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc); 3269 3270 // Handle the following exceptional case (*Obj).isa. 3271 if (!IsArrow && 3272 BaseType->isObjCObjectType() && 3273 BaseType->getAs<ObjCObjectType>()->isObjCId() && 3274 MemberName.getAsIdentifierInfo()->isStr("isa")) 3275 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3276 Context.getObjCClassType())); 3277 3278 // Handle 'field access' to vectors, such as 'V.xx'. 3279 if (BaseType->isExtVectorType()) { 3280 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3281 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3282 if (ret.isNull()) 3283 return ExprError(); 3284 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3285 MemberLoc)); 3286 } 3287 3288 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3289 << BaseType << BaseExpr->getSourceRange(); 3290 3291 return ExprError(); 3292} 3293 3294/// The main callback when the parser finds something like 3295/// expression . [nested-name-specifier] identifier 3296/// expression -> [nested-name-specifier] identifier 3297/// where 'identifier' encompasses a fairly broad spectrum of 3298/// possibilities, including destructor and operator references. 3299/// 3300/// \param OpKind either tok::arrow or tok::period 3301/// \param HasTrailingLParen whether the next token is '(', which 3302/// is used to diagnose mis-uses of special members that can 3303/// only be called 3304/// \param ObjCImpDecl the current ObjC @implementation decl; 3305/// this is an ugly hack around the fact that ObjC @implementations 3306/// aren't properly put in the context chain 3307Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, 3308 SourceLocation OpLoc, 3309 tok::TokenKind OpKind, 3310 CXXScopeSpec &SS, 3311 UnqualifiedId &Id, 3312 Decl *ObjCImpDecl, 3313 bool HasTrailingLParen) { 3314 if (SS.isSet() && SS.isInvalid()) 3315 return ExprError(); 3316 3317 TemplateArgumentListInfo TemplateArgsBuffer; 3318 3319 // Decompose the name into its component parts. 3320 DeclarationNameInfo NameInfo; 3321 const TemplateArgumentListInfo *TemplateArgs; 3322 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3323 NameInfo, TemplateArgs); 3324 3325 DeclarationName Name = NameInfo.getName(); 3326 bool IsArrow = (OpKind == tok::arrow); 3327 3328 NamedDecl *FirstQualifierInScope 3329 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3330 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3331 3332 // This is a postfix expression, so get rid of ParenListExprs. 3333 OwningExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 3334 if (Result.isInvalid()) return ExprError(); 3335 Base = Result.take(); 3336 3337 if (Base->getType()->isDependentType() || Name.isDependentName() || 3338 isDependentScopeSpecifier(SS)) { 3339 Result = ActOnDependentMemberExpr(Base, Base->getType(), 3340 IsArrow, OpLoc, 3341 SS, FirstQualifierInScope, 3342 NameInfo, TemplateArgs); 3343 } else { 3344 LookupResult R(*this, NameInfo, LookupMemberName); 3345 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3346 SS, ObjCImpDecl, TemplateArgs != 0); 3347 3348 if (Result.isInvalid()) { 3349 Owned(Base); 3350 return ExprError(); 3351 } 3352 3353 if (Result.get()) { 3354 // The only way a reference to a destructor can be used is to 3355 // immediately call it, which falls into this case. If the 3356 // next token is not a '(', produce a diagnostic and build the 3357 // call now. 3358 if (!HasTrailingLParen && 3359 Id.getKind() == UnqualifiedId::IK_DestructorName) 3360 return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); 3361 3362 return move(Result); 3363 } 3364 3365 Result = BuildMemberReferenceExpr(Base, Base->getType(), 3366 OpLoc, IsArrow, SS, FirstQualifierInScope, 3367 R, TemplateArgs); 3368 } 3369 3370 return move(Result); 3371} 3372 3373Sema::OwningExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3374 FunctionDecl *FD, 3375 ParmVarDecl *Param) { 3376 if (Param->hasUnparsedDefaultArg()) { 3377 Diag (CallLoc, 3378 diag::err_use_of_default_argument_to_function_declared_later) << 3379 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3380 Diag(UnparsedDefaultArgLocs[Param], 3381 diag::note_default_argument_declared_here); 3382 } else { 3383 if (Param->hasUninstantiatedDefaultArg()) { 3384 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3385 3386 // Instantiate the expression. 3387 MultiLevelTemplateArgumentList ArgList 3388 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3389 3390 std::pair<const TemplateArgument *, unsigned> Innermost 3391 = ArgList.getInnermost(); 3392 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3393 Innermost.second); 3394 3395 OwningExprResult Result = SubstExpr(UninstExpr, ArgList); 3396 if (Result.isInvalid()) 3397 return ExprError(); 3398 3399 // Check the expression as an initializer for the parameter. 3400 InitializedEntity Entity 3401 = InitializedEntity::InitializeParameter(Param); 3402 InitializationKind Kind 3403 = InitializationKind::CreateCopy(Param->getLocation(), 3404 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3405 Expr *ResultE = Result.takeAs<Expr>(); 3406 3407 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3408 Result = InitSeq.Perform(*this, Entity, Kind, 3409 MultiExprArg(*this, &ResultE, 1)); 3410 if (Result.isInvalid()) 3411 return ExprError(); 3412 3413 // Build the default argument expression. 3414 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3415 Result.takeAs<Expr>())); 3416 } 3417 3418 // If the default expression creates temporaries, we need to 3419 // push them to the current stack of expression temporaries so they'll 3420 // be properly destroyed. 3421 // FIXME: We should really be rebuilding the default argument with new 3422 // bound temporaries; see the comment in PR5810. 3423 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3424 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3425 } 3426 3427 // We already type-checked the argument, so we know it works. 3428 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3429} 3430 3431/// ConvertArgumentsForCall - Converts the arguments specified in 3432/// Args/NumArgs to the parameter types of the function FDecl with 3433/// function prototype Proto. Call is the call expression itself, and 3434/// Fn is the function expression. For a C++ member function, this 3435/// routine does not attempt to convert the object argument. Returns 3436/// true if the call is ill-formed. 3437bool 3438Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3439 FunctionDecl *FDecl, 3440 const FunctionProtoType *Proto, 3441 Expr **Args, unsigned NumArgs, 3442 SourceLocation RParenLoc) { 3443 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3444 // assignment, to the types of the corresponding parameter, ... 3445 unsigned NumArgsInProto = Proto->getNumArgs(); 3446 bool Invalid = false; 3447 3448 // If too few arguments are available (and we don't have default 3449 // arguments for the remaining parameters), don't make the call. 3450 if (NumArgs < NumArgsInProto) { 3451 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3452 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3453 << Fn->getType()->isBlockPointerType() 3454 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 3455 Call->setNumArgs(Context, NumArgsInProto); 3456 } 3457 3458 // If too many are passed and not variadic, error on the extras and drop 3459 // them. 3460 if (NumArgs > NumArgsInProto) { 3461 if (!Proto->isVariadic()) { 3462 Diag(Args[NumArgsInProto]->getLocStart(), 3463 diag::err_typecheck_call_too_many_args) 3464 << Fn->getType()->isBlockPointerType() 3465 << NumArgsInProto << NumArgs << Fn->getSourceRange() 3466 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3467 Args[NumArgs-1]->getLocEnd()); 3468 // This deletes the extra arguments. 3469 Call->setNumArgs(Context, NumArgsInProto); 3470 return true; 3471 } 3472 } 3473 llvm::SmallVector<Expr *, 8> AllArgs; 3474 VariadicCallType CallType = 3475 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3476 if (Fn->getType()->isBlockPointerType()) 3477 CallType = VariadicBlock; // Block 3478 else if (isa<MemberExpr>(Fn)) 3479 CallType = VariadicMethod; 3480 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3481 Proto, 0, Args, NumArgs, AllArgs, CallType); 3482 if (Invalid) 3483 return true; 3484 unsigned TotalNumArgs = AllArgs.size(); 3485 for (unsigned i = 0; i < TotalNumArgs; ++i) 3486 Call->setArg(i, AllArgs[i]); 3487 3488 return false; 3489} 3490 3491bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3492 FunctionDecl *FDecl, 3493 const FunctionProtoType *Proto, 3494 unsigned FirstProtoArg, 3495 Expr **Args, unsigned NumArgs, 3496 llvm::SmallVector<Expr *, 8> &AllArgs, 3497 VariadicCallType CallType) { 3498 unsigned NumArgsInProto = Proto->getNumArgs(); 3499 unsigned NumArgsToCheck = NumArgs; 3500 bool Invalid = false; 3501 if (NumArgs != NumArgsInProto) 3502 // Use default arguments for missing arguments 3503 NumArgsToCheck = NumArgsInProto; 3504 unsigned ArgIx = 0; 3505 // Continue to check argument types (even if we have too few/many args). 3506 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3507 QualType ProtoArgType = Proto->getArgType(i); 3508 3509 Expr *Arg; 3510 if (ArgIx < NumArgs) { 3511 Arg = Args[ArgIx++]; 3512 3513 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3514 ProtoArgType, 3515 PDiag(diag::err_call_incomplete_argument) 3516 << Arg->getSourceRange())) 3517 return true; 3518 3519 // Pass the argument 3520 ParmVarDecl *Param = 0; 3521 if (FDecl && i < FDecl->getNumParams()) 3522 Param = FDecl->getParamDecl(i); 3523 3524 3525 InitializedEntity Entity = 3526 Param? InitializedEntity::InitializeParameter(Param) 3527 : InitializedEntity::InitializeParameter(ProtoArgType); 3528 OwningExprResult ArgE = PerformCopyInitialization(Entity, 3529 SourceLocation(), 3530 Owned(Arg)); 3531 if (ArgE.isInvalid()) 3532 return true; 3533 3534 Arg = ArgE.takeAs<Expr>(); 3535 } else { 3536 ParmVarDecl *Param = FDecl->getParamDecl(i); 3537 3538 OwningExprResult ArgExpr = 3539 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3540 if (ArgExpr.isInvalid()) 3541 return true; 3542 3543 Arg = ArgExpr.takeAs<Expr>(); 3544 } 3545 AllArgs.push_back(Arg); 3546 } 3547 3548 // If this is a variadic call, handle args passed through "...". 3549 if (CallType != VariadicDoesNotApply) { 3550 // Promote the arguments (C99 6.5.2.2p7). 3551 for (unsigned i = ArgIx; i != NumArgs; ++i) { 3552 Expr *Arg = Args[i]; 3553 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 3554 AllArgs.push_back(Arg); 3555 } 3556 } 3557 return Invalid; 3558} 3559 3560/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3561/// This provides the location of the left/right parens and a list of comma 3562/// locations. 3563Action::OwningExprResult 3564Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, 3565 MultiExprArg args, 3566 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3567 unsigned NumArgs = args.size(); 3568 3569 // Since this might be a postfix expression, get rid of ParenListExprs. 3570 OwningExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); 3571 if (Result.isInvalid()) return ExprError(); 3572 Fn = Result.take(); 3573 3574 Expr **Args = args.release(); 3575 3576 if (getLangOptions().CPlusPlus) { 3577 // If this is a pseudo-destructor expression, build the call immediately. 3578 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3579 if (NumArgs > 0) { 3580 // Pseudo-destructor calls should not have any arguments. 3581 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3582 << FixItHint::CreateRemoval( 3583 SourceRange(Args[0]->getLocStart(), 3584 Args[NumArgs-1]->getLocEnd())); 3585 3586 NumArgs = 0; 3587 } 3588 3589 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3590 RParenLoc)); 3591 } 3592 3593 // Determine whether this is a dependent call inside a C++ template, 3594 // in which case we won't do any semantic analysis now. 3595 // FIXME: Will need to cache the results of name lookup (including ADL) in 3596 // Fn. 3597 bool Dependent = false; 3598 if (Fn->isTypeDependent()) 3599 Dependent = true; 3600 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3601 Dependent = true; 3602 3603 if (Dependent) 3604 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3605 Context.DependentTy, RParenLoc)); 3606 3607 // Determine whether this is a call to an object (C++ [over.call.object]). 3608 if (Fn->getType()->isRecordType()) 3609 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3610 CommaLocs, RParenLoc)); 3611 3612 Expr *NakedFn = Fn->IgnoreParens(); 3613 3614 // Determine whether this is a call to an unresolved member function. 3615 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3616 // If lookup was unresolved but not dependent (i.e. didn't find 3617 // an unresolved using declaration), it has to be an overloaded 3618 // function set, which means it must contain either multiple 3619 // declarations (all methods or method templates) or a single 3620 // method template. 3621 assert((MemE->getNumDecls() > 1) || 3622 isa<FunctionTemplateDecl>( 3623 (*MemE->decls_begin())->getUnderlyingDecl())); 3624 (void)MemE; 3625 3626 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3627 CommaLocs, RParenLoc); 3628 } 3629 3630 // Determine whether this is a call to a member function. 3631 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3632 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3633 if (isa<CXXMethodDecl>(MemDecl)) 3634 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3635 CommaLocs, RParenLoc); 3636 } 3637 3638 // Determine whether this is a call to a pointer-to-member function. 3639 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3640 if (BO->getOpcode() == BinaryOperator::PtrMemD || 3641 BO->getOpcode() == BinaryOperator::PtrMemI) { 3642 if (const FunctionProtoType *FPT 3643 = BO->getType()->getAs<FunctionProtoType>()) { 3644 QualType ResultTy = FPT->getCallResultType(Context); 3645 3646 CXXMemberCallExpr *TheCall 3647 = new (Context) CXXMemberCallExpr(Context, BO, Args, 3648 NumArgs, ResultTy, 3649 RParenLoc); 3650 3651 if (CheckCallReturnType(FPT->getResultType(), 3652 BO->getRHS()->getSourceRange().getBegin(), 3653 TheCall, 0)) 3654 return ExprError(); 3655 3656 if (ConvertArgumentsForCall(TheCall, BO, 0, FPT, Args, NumArgs, 3657 RParenLoc)) 3658 return ExprError(); 3659 3660 return MaybeBindToTemporary(TheCall); 3661 } 3662 return ExprError(Diag(Fn->getLocStart(), 3663 diag::err_typecheck_call_not_function) 3664 << Fn->getType() << Fn->getSourceRange()); 3665 } 3666 } 3667 } 3668 3669 // If we're directly calling a function, get the appropriate declaration. 3670 // Also, in C++, keep track of whether we should perform argument-dependent 3671 // lookup and whether there were any explicitly-specified template arguments. 3672 3673 Expr *NakedFn = Fn->IgnoreParens(); 3674 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3675 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3676 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 3677 CommaLocs, RParenLoc); 3678 } 3679 3680 NamedDecl *NDecl = 0; 3681 if (isa<DeclRefExpr>(NakedFn)) 3682 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3683 3684 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3685} 3686 3687/// BuildResolvedCallExpr - Build a call to a resolved expression, 3688/// i.e. an expression not of \p OverloadTy. The expression should 3689/// unary-convert to an expression of function-pointer or 3690/// block-pointer type. 3691/// 3692/// \param NDecl the declaration being called, if available 3693Sema::OwningExprResult 3694Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3695 SourceLocation LParenLoc, 3696 Expr **Args, unsigned NumArgs, 3697 SourceLocation RParenLoc) { 3698 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3699 3700 // Promote the function operand. 3701 UsualUnaryConversions(Fn); 3702 3703 // Make the call expr early, before semantic checks. This guarantees cleanup 3704 // of arguments and function on error. 3705 CallExpr *TheCall = new (Context) CallExpr(Context, Fn, 3706 Args, NumArgs, 3707 Context.BoolTy, 3708 RParenLoc); 3709 3710 const FunctionType *FuncT; 3711 if (!Fn->getType()->isBlockPointerType()) { 3712 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3713 // have type pointer to function". 3714 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3715 if (PT == 0) 3716 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3717 << Fn->getType() << Fn->getSourceRange()); 3718 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3719 } else { // This is a block call. 3720 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3721 getAs<FunctionType>(); 3722 } 3723 if (FuncT == 0) 3724 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3725 << Fn->getType() << Fn->getSourceRange()); 3726 3727 // Check for a valid return type 3728 if (CheckCallReturnType(FuncT->getResultType(), 3729 Fn->getSourceRange().getBegin(), TheCall, 3730 FDecl)) 3731 return ExprError(); 3732 3733 // We know the result type of the call, set it. 3734 TheCall->setType(FuncT->getCallResultType(Context)); 3735 3736 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3737 if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, NumArgs, 3738 RParenLoc)) 3739 return ExprError(); 3740 } else { 3741 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3742 3743 if (FDecl) { 3744 // Check if we have too few/too many template arguments, based 3745 // on our knowledge of the function definition. 3746 const FunctionDecl *Def = 0; 3747 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 3748 const FunctionProtoType *Proto = 3749 Def->getType()->getAs<FunctionProtoType>(); 3750 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3751 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3752 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3753 } 3754 } 3755 } 3756 3757 // Promote the arguments (C99 6.5.2.2p6). 3758 for (unsigned i = 0; i != NumArgs; i++) { 3759 Expr *Arg = Args[i]; 3760 DefaultArgumentPromotion(Arg); 3761 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3762 Arg->getType(), 3763 PDiag(diag::err_call_incomplete_argument) 3764 << Arg->getSourceRange())) 3765 return ExprError(); 3766 TheCall->setArg(i, Arg); 3767 } 3768 } 3769 3770 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3771 if (!Method->isStatic()) 3772 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3773 << Fn->getSourceRange()); 3774 3775 // Check for sentinels 3776 if (NDecl) 3777 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3778 3779 // Do special checking on direct calls to functions. 3780 if (FDecl) { 3781 if (CheckFunctionCall(FDecl, TheCall)) 3782 return ExprError(); 3783 3784 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3785 return CheckBuiltinFunctionCall(BuiltinID, TheCall); 3786 } else if (NDecl) { 3787 if (CheckBlockCall(NDecl, TheCall)) 3788 return ExprError(); 3789 } 3790 3791 return MaybeBindToTemporary(TheCall); 3792} 3793 3794Action::OwningExprResult 3795Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, 3796 SourceLocation RParenLoc, Expr *InitExpr) { 3797 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3798 // FIXME: put back this assert when initializers are worked out. 3799 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3800 3801 TypeSourceInfo *TInfo; 3802 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3803 if (!TInfo) 3804 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3805 3806 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); 3807} 3808 3809Action::OwningExprResult 3810Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3811 SourceLocation RParenLoc, Expr *literalExpr) { 3812 QualType literalType = TInfo->getType(); 3813 3814 if (literalType->isArrayType()) { 3815 if (literalType->isVariableArrayType()) 3816 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3817 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3818 } else if (!literalType->isDependentType() && 3819 RequireCompleteType(LParenLoc, literalType, 3820 PDiag(diag::err_typecheck_decl_incomplete_type) 3821 << SourceRange(LParenLoc, 3822 literalExpr->getSourceRange().getEnd()))) 3823 return ExprError(); 3824 3825 InitializedEntity Entity 3826 = InitializedEntity::InitializeTemporary(literalType); 3827 InitializationKind Kind 3828 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3829 /*IsCStyleCast=*/true); 3830 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3831 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3832 MultiExprArg(*this, &literalExpr, 1), 3833 &literalType); 3834 if (Result.isInvalid()) 3835 return ExprError(); 3836 literalExpr = Result.get(); 3837 3838 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3839 if (isFileScope) { // 6.5.2.5p3 3840 if (CheckForConstantInitializer(literalExpr, literalType)) 3841 return ExprError(); 3842 } 3843 3844 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3845 literalExpr, isFileScope)); 3846} 3847 3848Action::OwningExprResult 3849Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3850 SourceLocation RBraceLoc) { 3851 unsigned NumInit = initlist.size(); 3852 Expr **InitList = initlist.release(); 3853 3854 // Semantic analysis for initializers is done by ActOnDeclarator() and 3855 // CheckInitializer() - it requires knowledge of the object being intialized. 3856 3857 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 3858 NumInit, RBraceLoc); 3859 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3860 return Owned(E); 3861} 3862 3863static CastExpr::CastKind getScalarCastKind(ASTContext &Context, 3864 QualType SrcTy, QualType DestTy) { 3865 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3866 return CastExpr::CK_NoOp; 3867 3868 if (SrcTy->hasPointerRepresentation()) { 3869 if (DestTy->hasPointerRepresentation()) 3870 return DestTy->isObjCObjectPointerType() ? 3871 CastExpr::CK_AnyPointerToObjCPointerCast : 3872 CastExpr::CK_BitCast; 3873 if (DestTy->isIntegerType()) 3874 return CastExpr::CK_PointerToIntegral; 3875 } 3876 3877 if (SrcTy->isIntegerType()) { 3878 if (DestTy->isIntegerType()) 3879 return CastExpr::CK_IntegralCast; 3880 if (DestTy->hasPointerRepresentation()) 3881 return CastExpr::CK_IntegralToPointer; 3882 if (DestTy->isRealFloatingType()) 3883 return CastExpr::CK_IntegralToFloating; 3884 } 3885 3886 if (SrcTy->isRealFloatingType()) { 3887 if (DestTy->isRealFloatingType()) 3888 return CastExpr::CK_FloatingCast; 3889 if (DestTy->isIntegerType()) 3890 return CastExpr::CK_FloatingToIntegral; 3891 } 3892 3893 // FIXME: Assert here. 3894 // assert(false && "Unhandled cast combination!"); 3895 return CastExpr::CK_Unknown; 3896} 3897 3898/// CheckCastTypes - Check type constraints for casting between types. 3899bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3900 CastExpr::CastKind& Kind, 3901 CXXCastPath &BasePath, 3902 bool FunctionalStyle) { 3903 if (getLangOptions().CPlusPlus) 3904 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, BasePath, 3905 FunctionalStyle); 3906 3907 DefaultFunctionArrayLvalueConversion(castExpr); 3908 3909 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3910 // type needs to be scalar. 3911 if (castType->isVoidType()) { 3912 // Cast to void allows any expr type. 3913 Kind = CastExpr::CK_ToVoid; 3914 return false; 3915 } 3916 3917 if (RequireCompleteType(TyR.getBegin(), castType, 3918 diag::err_typecheck_cast_to_incomplete)) 3919 return true; 3920 3921 if (!castType->isScalarType() && !castType->isVectorType()) { 3922 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3923 (castType->isStructureType() || castType->isUnionType())) { 3924 // GCC struct/union extension: allow cast to self. 3925 // FIXME: Check that the cast destination type is complete. 3926 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3927 << castType << castExpr->getSourceRange(); 3928 Kind = CastExpr::CK_NoOp; 3929 return false; 3930 } 3931 3932 if (castType->isUnionType()) { 3933 // GCC cast to union extension 3934 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3935 RecordDecl::field_iterator Field, FieldEnd; 3936 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3937 Field != FieldEnd; ++Field) { 3938 if (Context.hasSameUnqualifiedType(Field->getType(), 3939 castExpr->getType())) { 3940 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3941 << castExpr->getSourceRange(); 3942 break; 3943 } 3944 } 3945 if (Field == FieldEnd) 3946 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3947 << castExpr->getType() << castExpr->getSourceRange(); 3948 Kind = CastExpr::CK_ToUnion; 3949 return false; 3950 } 3951 3952 // Reject any other conversions to non-scalar types. 3953 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3954 << castType << castExpr->getSourceRange(); 3955 } 3956 3957 if (!castExpr->getType()->isScalarType() && 3958 !castExpr->getType()->isVectorType()) { 3959 return Diag(castExpr->getLocStart(), 3960 diag::err_typecheck_expect_scalar_operand) 3961 << castExpr->getType() << castExpr->getSourceRange(); 3962 } 3963 3964 if (castType->isExtVectorType()) 3965 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3966 3967 if (castType->isVectorType()) 3968 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 3969 if (castExpr->getType()->isVectorType()) 3970 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 3971 3972 if (isa<ObjCSelectorExpr>(castExpr)) 3973 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 3974 3975 if (!castType->isArithmeticType()) { 3976 QualType castExprType = castExpr->getType(); 3977 if (!castExprType->isIntegralType(Context) && 3978 castExprType->isArithmeticType()) 3979 return Diag(castExpr->getLocStart(), 3980 diag::err_cast_pointer_from_non_pointer_int) 3981 << castExprType << castExpr->getSourceRange(); 3982 } else if (!castExpr->getType()->isArithmeticType()) { 3983 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 3984 return Diag(castExpr->getLocStart(), 3985 diag::err_cast_pointer_to_non_pointer_int) 3986 << castType << castExpr->getSourceRange(); 3987 } 3988 3989 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 3990 3991 if (Kind == CastExpr::CK_Unknown || Kind == CastExpr::CK_BitCast) 3992 CheckCastAlign(castExpr, castType, TyR); 3993 3994 return false; 3995} 3996 3997bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 3998 CastExpr::CastKind &Kind) { 3999 assert(VectorTy->isVectorType() && "Not a vector type!"); 4000 4001 if (Ty->isVectorType() || Ty->isIntegerType()) { 4002 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 4003 return Diag(R.getBegin(), 4004 Ty->isVectorType() ? 4005 diag::err_invalid_conversion_between_vectors : 4006 diag::err_invalid_conversion_between_vector_and_integer) 4007 << VectorTy << Ty << R; 4008 } else 4009 return Diag(R.getBegin(), 4010 diag::err_invalid_conversion_between_vector_and_scalar) 4011 << VectorTy << Ty << R; 4012 4013 Kind = CastExpr::CK_BitCast; 4014 return false; 4015} 4016 4017bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4018 CastExpr::CastKind &Kind) { 4019 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4020 4021 QualType SrcTy = CastExpr->getType(); 4022 4023 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4024 // an ExtVectorType. 4025 if (SrcTy->isVectorType()) { 4026 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4027 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4028 << DestTy << SrcTy << R; 4029 Kind = CastExpr::CK_BitCast; 4030 return false; 4031 } 4032 4033 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4034 // conversion will take place first from scalar to elt type, and then 4035 // splat from elt type to vector. 4036 if (SrcTy->isPointerType()) 4037 return Diag(R.getBegin(), 4038 diag::err_invalid_conversion_between_vector_and_scalar) 4039 << DestTy << SrcTy << R; 4040 4041 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4042 ImpCastExprToType(CastExpr, DestElemTy, 4043 getScalarCastKind(Context, SrcTy, DestElemTy)); 4044 4045 Kind = CastExpr::CK_VectorSplat; 4046 return false; 4047} 4048 4049Action::OwningExprResult 4050Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, ParsedType Ty, 4051 SourceLocation RParenLoc, Expr *castExpr) { 4052 assert((Ty != 0) && (castExpr != 0) && 4053 "ActOnCastExpr(): missing type or expr"); 4054 4055 TypeSourceInfo *castTInfo; 4056 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4057 if (!castTInfo) 4058 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4059 4060 // If the Expr being casted is a ParenListExpr, handle it specially. 4061 if (isa<ParenListExpr>(castExpr)) 4062 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, castExpr, 4063 castTInfo); 4064 4065 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, castExpr); 4066} 4067 4068Action::OwningExprResult 4069Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4070 SourceLocation RParenLoc, Expr *castExpr) { 4071 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 4072 CXXCastPath BasePath; 4073 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4074 Kind, BasePath)) 4075 return ExprError(); 4076 4077 return Owned(CStyleCastExpr::Create(Context, 4078 Ty->getType().getNonLValueExprType(Context), 4079 Kind, castExpr, &BasePath, Ty, 4080 LParenLoc, RParenLoc)); 4081} 4082 4083/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4084/// of comma binary operators. 4085OwningExprResult 4086Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *expr) { 4087 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4088 if (!E) 4089 return Owned(expr); 4090 4091 OwningExprResult Result(E->getExpr(0)); 4092 4093 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4094 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), 4095 E->getExpr(i)); 4096 4097 if (Result.isInvalid()) return ExprError(); 4098 4099 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); 4100} 4101 4102Action::OwningExprResult 4103Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4104 SourceLocation RParenLoc, Expr *Op, 4105 TypeSourceInfo *TInfo) { 4106 ParenListExpr *PE = cast<ParenListExpr>(Op); 4107 QualType Ty = TInfo->getType(); 4108 bool isAltiVecLiteral = false; 4109 4110 // Check for an altivec literal, 4111 // i.e. all the elements are integer constants. 4112 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4113 if (PE->getNumExprs() == 0) { 4114 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4115 return ExprError(); 4116 } 4117 if (PE->getNumExprs() == 1) { 4118 if (!PE->getExpr(0)->getType()->isVectorType()) 4119 isAltiVecLiteral = true; 4120 } 4121 else 4122 isAltiVecLiteral = true; 4123 } 4124 4125 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4126 // then handle it as such. 4127 if (isAltiVecLiteral) { 4128 llvm::SmallVector<Expr *, 8> initExprs; 4129 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4130 initExprs.push_back(PE->getExpr(i)); 4131 4132 // FIXME: This means that pretty-printing the final AST will produce curly 4133 // braces instead of the original commas. 4134 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4135 &initExprs[0], 4136 initExprs.size(), RParenLoc); 4137 E->setType(Ty); 4138 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, E); 4139 } else { 4140 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4141 // sequence of BinOp comma operators. 4142 OwningExprResult Result = MaybeConvertParenListExprToParenExpr(S, Op); 4143 if (Result.isInvalid()) return ExprError(); 4144 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Result.take()); 4145 } 4146} 4147 4148Action::OwningExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4149 SourceLocation R, 4150 MultiExprArg Val, 4151 ParsedType TypeOfCast) { 4152 unsigned nexprs = Val.size(); 4153 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4154 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4155 Expr *expr; 4156 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4157 expr = new (Context) ParenExpr(L, R, exprs[0]); 4158 else 4159 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4160 return Owned(expr); 4161} 4162 4163/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4164/// In that case, lhs = cond. 4165/// C99 6.5.15 4166QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4167 SourceLocation QuestionLoc) { 4168 // C++ is sufficiently different to merit its own checker. 4169 if (getLangOptions().CPlusPlus) 4170 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4171 4172 UsualUnaryConversions(Cond); 4173 UsualUnaryConversions(LHS); 4174 UsualUnaryConversions(RHS); 4175 QualType CondTy = Cond->getType(); 4176 QualType LHSTy = LHS->getType(); 4177 QualType RHSTy = RHS->getType(); 4178 4179 // first, check the condition. 4180 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4181 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4182 << CondTy; 4183 return QualType(); 4184 } 4185 4186 // Now check the two expressions. 4187 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4188 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4189 4190 // If both operands have arithmetic type, do the usual arithmetic conversions 4191 // to find a common type: C99 6.5.15p3,5. 4192 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4193 UsualArithmeticConversions(LHS, RHS); 4194 return LHS->getType(); 4195 } 4196 4197 // If both operands are the same structure or union type, the result is that 4198 // type. 4199 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4200 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4201 if (LHSRT->getDecl() == RHSRT->getDecl()) 4202 // "If both the operands have structure or union type, the result has 4203 // that type." This implies that CV qualifiers are dropped. 4204 return LHSTy.getUnqualifiedType(); 4205 // FIXME: Type of conditional expression must be complete in C mode. 4206 } 4207 4208 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4209 // The following || allows only one side to be void (a GCC-ism). 4210 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4211 if (!LHSTy->isVoidType()) 4212 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4213 << RHS->getSourceRange(); 4214 if (!RHSTy->isVoidType()) 4215 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4216 << LHS->getSourceRange(); 4217 ImpCastExprToType(LHS, Context.VoidTy, CastExpr::CK_ToVoid); 4218 ImpCastExprToType(RHS, Context.VoidTy, CastExpr::CK_ToVoid); 4219 return Context.VoidTy; 4220 } 4221 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4222 // the type of the other operand." 4223 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4224 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4225 // promote the null to a pointer. 4226 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_Unknown); 4227 return LHSTy; 4228 } 4229 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4230 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4231 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_Unknown); 4232 return RHSTy; 4233 } 4234 4235 // All objective-c pointer type analysis is done here. 4236 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4237 QuestionLoc); 4238 if (!compositeType.isNull()) 4239 return compositeType; 4240 4241 4242 // Handle block pointer types. 4243 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4244 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4245 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4246 QualType destType = Context.getPointerType(Context.VoidTy); 4247 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4248 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4249 return destType; 4250 } 4251 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4252 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4253 return QualType(); 4254 } 4255 // We have 2 block pointer types. 4256 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4257 // Two identical block pointer types are always compatible. 4258 return LHSTy; 4259 } 4260 // The block pointer types aren't identical, continue checking. 4261 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4262 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4263 4264 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4265 rhptee.getUnqualifiedType())) { 4266 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4267 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4268 // In this situation, we assume void* type. No especially good 4269 // reason, but this is what gcc does, and we do have to pick 4270 // to get a consistent AST. 4271 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4272 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4273 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4274 return incompatTy; 4275 } 4276 // The block pointer types are compatible. 4277 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4278 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4279 return LHSTy; 4280 } 4281 4282 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4283 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4284 // get the "pointed to" types 4285 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4286 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4287 4288 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4289 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4290 // Figure out necessary qualifiers (C99 6.5.15p6) 4291 QualType destPointee 4292 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4293 QualType destType = Context.getPointerType(destPointee); 4294 // Add qualifiers if necessary. 4295 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4296 // Promote to void*. 4297 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4298 return destType; 4299 } 4300 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4301 QualType destPointee 4302 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4303 QualType destType = Context.getPointerType(destPointee); 4304 // Add qualifiers if necessary. 4305 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4306 // Promote to void*. 4307 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4308 return destType; 4309 } 4310 4311 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4312 // Two identical pointer types are always compatible. 4313 return LHSTy; 4314 } 4315 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4316 rhptee.getUnqualifiedType())) { 4317 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4318 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4319 // In this situation, we assume void* type. No especially good 4320 // reason, but this is what gcc does, and we do have to pick 4321 // to get a consistent AST. 4322 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4323 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4324 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4325 return incompatTy; 4326 } 4327 // The pointer types are compatible. 4328 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4329 // differently qualified versions of compatible types, the result type is 4330 // a pointer to an appropriately qualified version of the *composite* 4331 // type. 4332 // FIXME: Need to calculate the composite type. 4333 // FIXME: Need to add qualifiers 4334 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4335 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4336 return LHSTy; 4337 } 4338 4339 // GCC compatibility: soften pointer/integer mismatch. 4340 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4341 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4342 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4343 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_IntegralToPointer); 4344 return RHSTy; 4345 } 4346 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4347 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4348 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4349 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_IntegralToPointer); 4350 return LHSTy; 4351 } 4352 4353 // Otherwise, the operands are not compatible. 4354 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4355 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4356 return QualType(); 4357} 4358 4359/// FindCompositeObjCPointerType - Helper method to find composite type of 4360/// two objective-c pointer types of the two input expressions. 4361QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4362 SourceLocation QuestionLoc) { 4363 QualType LHSTy = LHS->getType(); 4364 QualType RHSTy = RHS->getType(); 4365 4366 // Handle things like Class and struct objc_class*. Here we case the result 4367 // to the pseudo-builtin, because that will be implicitly cast back to the 4368 // redefinition type if an attempt is made to access its fields. 4369 if (LHSTy->isObjCClassType() && 4370 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4371 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4372 return LHSTy; 4373 } 4374 if (RHSTy->isObjCClassType() && 4375 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4376 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4377 return RHSTy; 4378 } 4379 // And the same for struct objc_object* / id 4380 if (LHSTy->isObjCIdType() && 4381 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4382 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4383 return LHSTy; 4384 } 4385 if (RHSTy->isObjCIdType() && 4386 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4387 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4388 return RHSTy; 4389 } 4390 // And the same for struct objc_selector* / SEL 4391 if (Context.isObjCSelType(LHSTy) && 4392 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4393 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4394 return LHSTy; 4395 } 4396 if (Context.isObjCSelType(RHSTy) && 4397 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4398 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4399 return RHSTy; 4400 } 4401 // Check constraints for Objective-C object pointers types. 4402 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4403 4404 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4405 // Two identical object pointer types are always compatible. 4406 return LHSTy; 4407 } 4408 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4409 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4410 QualType compositeType = LHSTy; 4411 4412 // If both operands are interfaces and either operand can be 4413 // assigned to the other, use that type as the composite 4414 // type. This allows 4415 // xxx ? (A*) a : (B*) b 4416 // where B is a subclass of A. 4417 // 4418 // Additionally, as for assignment, if either type is 'id' 4419 // allow silent coercion. Finally, if the types are 4420 // incompatible then make sure to use 'id' as the composite 4421 // type so the result is acceptable for sending messages to. 4422 4423 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4424 // It could return the composite type. 4425 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4426 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4427 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4428 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4429 } else if ((LHSTy->isObjCQualifiedIdType() || 4430 RHSTy->isObjCQualifiedIdType()) && 4431 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4432 // Need to handle "id<xx>" explicitly. 4433 // GCC allows qualified id and any Objective-C type to devolve to 4434 // id. Currently localizing to here until clear this should be 4435 // part of ObjCQualifiedIdTypesAreCompatible. 4436 compositeType = Context.getObjCIdType(); 4437 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4438 compositeType = Context.getObjCIdType(); 4439 } else if (!(compositeType = 4440 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4441 ; 4442 else { 4443 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4444 << LHSTy << RHSTy 4445 << LHS->getSourceRange() << RHS->getSourceRange(); 4446 QualType incompatTy = Context.getObjCIdType(); 4447 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4448 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4449 return incompatTy; 4450 } 4451 // The object pointer types are compatible. 4452 ImpCastExprToType(LHS, compositeType, CastExpr::CK_BitCast); 4453 ImpCastExprToType(RHS, compositeType, CastExpr::CK_BitCast); 4454 return compositeType; 4455 } 4456 // Check Objective-C object pointer types and 'void *' 4457 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4458 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4459 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4460 QualType destPointee 4461 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4462 QualType destType = Context.getPointerType(destPointee); 4463 // Add qualifiers if necessary. 4464 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4465 // Promote to void*. 4466 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4467 return destType; 4468 } 4469 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4470 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4471 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4472 QualType destPointee 4473 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4474 QualType destType = Context.getPointerType(destPointee); 4475 // Add qualifiers if necessary. 4476 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4477 // Promote to void*. 4478 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4479 return destType; 4480 } 4481 return QualType(); 4482} 4483 4484/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4485/// in the case of a the GNU conditional expr extension. 4486Action::OwningExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4487 SourceLocation ColonLoc, 4488 Expr *CondExpr, Expr *LHSExpr, 4489 Expr *RHSExpr) { 4490 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4491 // was the condition. 4492 bool isLHSNull = LHSExpr == 0; 4493 if (isLHSNull) 4494 LHSExpr = CondExpr; 4495 4496 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4497 RHSExpr, QuestionLoc); 4498 if (result.isNull()) 4499 return ExprError(); 4500 4501 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4502 isLHSNull ? 0 : LHSExpr, 4503 ColonLoc, RHSExpr, result)); 4504} 4505 4506// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4507// being closely modeled after the C99 spec:-). The odd characteristic of this 4508// routine is it effectively iqnores the qualifiers on the top level pointee. 4509// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4510// FIXME: add a couple examples in this comment. 4511Sema::AssignConvertType 4512Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4513 QualType lhptee, rhptee; 4514 4515 if ((lhsType->isObjCClassType() && 4516 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4517 (rhsType->isObjCClassType() && 4518 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4519 return Compatible; 4520 } 4521 4522 // get the "pointed to" type (ignoring qualifiers at the top level) 4523 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4524 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4525 4526 // make sure we operate on the canonical type 4527 lhptee = Context.getCanonicalType(lhptee); 4528 rhptee = Context.getCanonicalType(rhptee); 4529 4530 AssignConvertType ConvTy = Compatible; 4531 4532 // C99 6.5.16.1p1: This following citation is common to constraints 4533 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4534 // qualifiers of the type *pointed to* by the right; 4535 // FIXME: Handle ExtQualType 4536 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4537 ConvTy = CompatiblePointerDiscardsQualifiers; 4538 4539 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4540 // incomplete type and the other is a pointer to a qualified or unqualified 4541 // version of void... 4542 if (lhptee->isVoidType()) { 4543 if (rhptee->isIncompleteOrObjectType()) 4544 return ConvTy; 4545 4546 // As an extension, we allow cast to/from void* to function pointer. 4547 assert(rhptee->isFunctionType()); 4548 return FunctionVoidPointer; 4549 } 4550 4551 if (rhptee->isVoidType()) { 4552 if (lhptee->isIncompleteOrObjectType()) 4553 return ConvTy; 4554 4555 // As an extension, we allow cast to/from void* to function pointer. 4556 assert(lhptee->isFunctionType()); 4557 return FunctionVoidPointer; 4558 } 4559 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4560 // unqualified versions of compatible types, ... 4561 lhptee = lhptee.getUnqualifiedType(); 4562 rhptee = rhptee.getUnqualifiedType(); 4563 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4564 // Check if the pointee types are compatible ignoring the sign. 4565 // We explicitly check for char so that we catch "char" vs 4566 // "unsigned char" on systems where "char" is unsigned. 4567 if (lhptee->isCharType()) 4568 lhptee = Context.UnsignedCharTy; 4569 else if (lhptee->hasSignedIntegerRepresentation()) 4570 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4571 4572 if (rhptee->isCharType()) 4573 rhptee = Context.UnsignedCharTy; 4574 else if (rhptee->hasSignedIntegerRepresentation()) 4575 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4576 4577 if (lhptee == rhptee) { 4578 // Types are compatible ignoring the sign. Qualifier incompatibility 4579 // takes priority over sign incompatibility because the sign 4580 // warning can be disabled. 4581 if (ConvTy != Compatible) 4582 return ConvTy; 4583 return IncompatiblePointerSign; 4584 } 4585 4586 // If we are a multi-level pointer, it's possible that our issue is simply 4587 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4588 // the eventual target type is the same and the pointers have the same 4589 // level of indirection, this must be the issue. 4590 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4591 do { 4592 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4593 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4594 4595 lhptee = Context.getCanonicalType(lhptee); 4596 rhptee = Context.getCanonicalType(rhptee); 4597 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4598 4599 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4600 return IncompatibleNestedPointerQualifiers; 4601 } 4602 4603 // General pointer incompatibility takes priority over qualifiers. 4604 return IncompatiblePointer; 4605 } 4606 return ConvTy; 4607} 4608 4609/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4610/// block pointer types are compatible or whether a block and normal pointer 4611/// are compatible. It is more restrict than comparing two function pointer 4612// types. 4613Sema::AssignConvertType 4614Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4615 QualType rhsType) { 4616 QualType lhptee, rhptee; 4617 4618 // get the "pointed to" type (ignoring qualifiers at the top level) 4619 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4620 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4621 4622 // make sure we operate on the canonical type 4623 lhptee = Context.getCanonicalType(lhptee); 4624 rhptee = Context.getCanonicalType(rhptee); 4625 4626 AssignConvertType ConvTy = Compatible; 4627 4628 // For blocks we enforce that qualifiers are identical. 4629 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4630 ConvTy = CompatiblePointerDiscardsQualifiers; 4631 4632 if (!getLangOptions().CPlusPlus) { 4633 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4634 return IncompatibleBlockPointer; 4635 } 4636 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4637 return IncompatibleBlockPointer; 4638 return ConvTy; 4639} 4640 4641/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4642/// for assignment compatibility. 4643Sema::AssignConvertType 4644Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4645 if (lhsType->isObjCBuiltinType()) { 4646 // Class is not compatible with ObjC object pointers. 4647 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4648 !rhsType->isObjCQualifiedClassType()) 4649 return IncompatiblePointer; 4650 return Compatible; 4651 } 4652 if (rhsType->isObjCBuiltinType()) { 4653 // Class is not compatible with ObjC object pointers. 4654 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4655 !lhsType->isObjCQualifiedClassType()) 4656 return IncompatiblePointer; 4657 return Compatible; 4658 } 4659 QualType lhptee = 4660 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4661 QualType rhptee = 4662 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4663 // make sure we operate on the canonical type 4664 lhptee = Context.getCanonicalType(lhptee); 4665 rhptee = Context.getCanonicalType(rhptee); 4666 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4667 return CompatiblePointerDiscardsQualifiers; 4668 4669 if (Context.typesAreCompatible(lhsType, rhsType)) 4670 return Compatible; 4671 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4672 return IncompatibleObjCQualifiedId; 4673 return IncompatiblePointer; 4674} 4675 4676/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4677/// has code to accommodate several GCC extensions when type checking 4678/// pointers. Here are some objectionable examples that GCC considers warnings: 4679/// 4680/// int a, *pint; 4681/// short *pshort; 4682/// struct foo *pfoo; 4683/// 4684/// pint = pshort; // warning: assignment from incompatible pointer type 4685/// a = pint; // warning: assignment makes integer from pointer without a cast 4686/// pint = a; // warning: assignment makes pointer from integer without a cast 4687/// pint = pfoo; // warning: assignment from incompatible pointer type 4688/// 4689/// As a result, the code for dealing with pointers is more complex than the 4690/// C99 spec dictates. 4691/// 4692Sema::AssignConvertType 4693Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4694 // Get canonical types. We're not formatting these types, just comparing 4695 // them. 4696 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4697 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4698 4699 if (lhsType == rhsType) 4700 return Compatible; // Common case: fast path an exact match. 4701 4702 if ((lhsType->isObjCClassType() && 4703 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4704 (rhsType->isObjCClassType() && 4705 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4706 return Compatible; 4707 } 4708 4709 // If the left-hand side is a reference type, then we are in a 4710 // (rare!) case where we've allowed the use of references in C, 4711 // e.g., as a parameter type in a built-in function. In this case, 4712 // just make sure that the type referenced is compatible with the 4713 // right-hand side type. The caller is responsible for adjusting 4714 // lhsType so that the resulting expression does not have reference 4715 // type. 4716 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4717 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4718 return Compatible; 4719 return Incompatible; 4720 } 4721 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4722 // to the same ExtVector type. 4723 if (lhsType->isExtVectorType()) { 4724 if (rhsType->isExtVectorType()) 4725 return lhsType == rhsType ? Compatible : Incompatible; 4726 if (rhsType->isArithmeticType()) 4727 return Compatible; 4728 } 4729 4730 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4731 if (lhsType->isVectorType() && rhsType->isVectorType()) { 4732 // If we are allowing lax vector conversions, and LHS and RHS are both 4733 // vectors, the total size only needs to be the same. This is a bitcast; 4734 // no bits are changed but the result type is different. 4735 if (getLangOptions().LaxVectorConversions && 4736 (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) 4737 return IncompatibleVectors; 4738 4739 // Allow assignments of an AltiVec vector type to an equivalent GCC 4740 // vector type and vice versa 4741 if (Context.areCompatibleVectorTypes(lhsType, rhsType)) 4742 return Compatible; 4743 } 4744 return Incompatible; 4745 } 4746 4747 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 4748 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) 4749 return Compatible; 4750 4751 if (isa<PointerType>(lhsType)) { 4752 if (rhsType->isIntegerType()) 4753 return IntToPointer; 4754 4755 if (isa<PointerType>(rhsType)) 4756 return CheckPointerTypesForAssignment(lhsType, rhsType); 4757 4758 // In general, C pointers are not compatible with ObjC object pointers. 4759 if (isa<ObjCObjectPointerType>(rhsType)) { 4760 if (lhsType->isVoidPointerType()) // an exception to the rule. 4761 return Compatible; 4762 return IncompatiblePointer; 4763 } 4764 if (rhsType->getAs<BlockPointerType>()) { 4765 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4766 return Compatible; 4767 4768 // Treat block pointers as objects. 4769 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4770 return Compatible; 4771 } 4772 return Incompatible; 4773 } 4774 4775 if (isa<BlockPointerType>(lhsType)) { 4776 if (rhsType->isIntegerType()) 4777 return IntToBlockPointer; 4778 4779 // Treat block pointers as objects. 4780 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4781 return Compatible; 4782 4783 if (rhsType->isBlockPointerType()) 4784 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4785 4786 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4787 if (RHSPT->getPointeeType()->isVoidType()) 4788 return Compatible; 4789 } 4790 return Incompatible; 4791 } 4792 4793 if (isa<ObjCObjectPointerType>(lhsType)) { 4794 if (rhsType->isIntegerType()) 4795 return IntToPointer; 4796 4797 // In general, C pointers are not compatible with ObjC object pointers. 4798 if (isa<PointerType>(rhsType)) { 4799 if (rhsType->isVoidPointerType()) // an exception to the rule. 4800 return Compatible; 4801 return IncompatiblePointer; 4802 } 4803 if (rhsType->isObjCObjectPointerType()) { 4804 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4805 } 4806 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4807 if (RHSPT->getPointeeType()->isVoidType()) 4808 return Compatible; 4809 } 4810 // Treat block pointers as objects. 4811 if (rhsType->isBlockPointerType()) 4812 return Compatible; 4813 return Incompatible; 4814 } 4815 if (isa<PointerType>(rhsType)) { 4816 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4817 if (lhsType == Context.BoolTy) 4818 return Compatible; 4819 4820 if (lhsType->isIntegerType()) 4821 return PointerToInt; 4822 4823 if (isa<PointerType>(lhsType)) 4824 return CheckPointerTypesForAssignment(lhsType, rhsType); 4825 4826 if (isa<BlockPointerType>(lhsType) && 4827 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4828 return Compatible; 4829 return Incompatible; 4830 } 4831 if (isa<ObjCObjectPointerType>(rhsType)) { 4832 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4833 if (lhsType == Context.BoolTy) 4834 return Compatible; 4835 4836 if (lhsType->isIntegerType()) 4837 return PointerToInt; 4838 4839 // In general, C pointers are not compatible with ObjC object pointers. 4840 if (isa<PointerType>(lhsType)) { 4841 if (lhsType->isVoidPointerType()) // an exception to the rule. 4842 return Compatible; 4843 return IncompatiblePointer; 4844 } 4845 if (isa<BlockPointerType>(lhsType) && 4846 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4847 return Compatible; 4848 return Incompatible; 4849 } 4850 4851 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4852 if (Context.typesAreCompatible(lhsType, rhsType)) 4853 return Compatible; 4854 } 4855 return Incompatible; 4856} 4857 4858/// \brief Constructs a transparent union from an expression that is 4859/// used to initialize the transparent union. 4860static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4861 QualType UnionType, FieldDecl *Field) { 4862 // Build an initializer list that designates the appropriate member 4863 // of the transparent union. 4864 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 4865 &E, 1, 4866 SourceLocation()); 4867 Initializer->setType(UnionType); 4868 Initializer->setInitializedFieldInUnion(Field); 4869 4870 // Build a compound literal constructing a value of the transparent 4871 // union type from this initializer list. 4872 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4873 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4874 Initializer, false); 4875} 4876 4877Sema::AssignConvertType 4878Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4879 QualType FromType = rExpr->getType(); 4880 4881 // If the ArgType is a Union type, we want to handle a potential 4882 // transparent_union GCC extension. 4883 const RecordType *UT = ArgType->getAsUnionType(); 4884 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4885 return Incompatible; 4886 4887 // The field to initialize within the transparent union. 4888 RecordDecl *UD = UT->getDecl(); 4889 FieldDecl *InitField = 0; 4890 // It's compatible if the expression matches any of the fields. 4891 for (RecordDecl::field_iterator it = UD->field_begin(), 4892 itend = UD->field_end(); 4893 it != itend; ++it) { 4894 if (it->getType()->isPointerType()) { 4895 // If the transparent union contains a pointer type, we allow: 4896 // 1) void pointer 4897 // 2) null pointer constant 4898 if (FromType->isPointerType()) 4899 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4900 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_BitCast); 4901 InitField = *it; 4902 break; 4903 } 4904 4905 if (rExpr->isNullPointerConstant(Context, 4906 Expr::NPC_ValueDependentIsNull)) { 4907 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_IntegralToPointer); 4908 InitField = *it; 4909 break; 4910 } 4911 } 4912 4913 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4914 == Compatible) { 4915 InitField = *it; 4916 break; 4917 } 4918 } 4919 4920 if (!InitField) 4921 return Incompatible; 4922 4923 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4924 return Compatible; 4925} 4926 4927Sema::AssignConvertType 4928Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4929 if (getLangOptions().CPlusPlus) { 4930 if (!lhsType->isRecordType()) { 4931 // C++ 5.17p3: If the left operand is not of class type, the 4932 // expression is implicitly converted (C++ 4) to the 4933 // cv-unqualified type of the left operand. 4934 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4935 AA_Assigning)) 4936 return Incompatible; 4937 return Compatible; 4938 } 4939 4940 // FIXME: Currently, we fall through and treat C++ classes like C 4941 // structures. 4942 } 4943 4944 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4945 // a null pointer constant. 4946 if ((lhsType->isPointerType() || 4947 lhsType->isObjCObjectPointerType() || 4948 lhsType->isBlockPointerType()) 4949 && rExpr->isNullPointerConstant(Context, 4950 Expr::NPC_ValueDependentIsNull)) { 4951 ImpCastExprToType(rExpr, lhsType, CastExpr::CK_Unknown); 4952 return Compatible; 4953 } 4954 4955 // This check seems unnatural, however it is necessary to ensure the proper 4956 // conversion of functions/arrays. If the conversion were done for all 4957 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4958 // expressions that suppress this implicit conversion (&, sizeof). 4959 // 4960 // Suppress this for references: C++ 8.5.3p5. 4961 if (!lhsType->isReferenceType()) 4962 DefaultFunctionArrayLvalueConversion(rExpr); 4963 4964 Sema::AssignConvertType result = 4965 CheckAssignmentConstraints(lhsType, rExpr->getType()); 4966 4967 // C99 6.5.16.1p2: The value of the right operand is converted to the 4968 // type of the assignment expression. 4969 // CheckAssignmentConstraints allows the left-hand side to be a reference, 4970 // so that we can use references in built-in functions even in C. 4971 // The getNonReferenceType() call makes sure that the resulting expression 4972 // does not have reference type. 4973 if (result != Incompatible && rExpr->getType() != lhsType) 4974 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), 4975 CastExpr::CK_Unknown); 4976 return result; 4977} 4978 4979QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4980 Diag(Loc, diag::err_typecheck_invalid_operands) 4981 << lex->getType() << rex->getType() 4982 << lex->getSourceRange() << rex->getSourceRange(); 4983 return QualType(); 4984} 4985 4986QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4987 // For conversion purposes, we ignore any qualifiers. 4988 // For example, "const float" and "float" are equivalent. 4989 QualType lhsType = 4990 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 4991 QualType rhsType = 4992 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 4993 4994 // If the vector types are identical, return. 4995 if (lhsType == rhsType) 4996 return lhsType; 4997 4998 // Handle the case of a vector & extvector type of the same size and element 4999 // type. It would be nice if we only had one vector type someday. 5000 if (getLangOptions().LaxVectorConversions) { 5001 // FIXME: Should we warn here? 5002 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5003 if (const VectorType *RV = rhsType->getAs<VectorType>()) 5004 if (LV->getElementType() == RV->getElementType() && 5005 LV->getNumElements() == RV->getNumElements()) { 5006 if (lhsType->isExtVectorType()) { 5007 ImpCastExprToType(rex, lhsType, CastExpr::CK_BitCast); 5008 return lhsType; 5009 } 5010 5011 ImpCastExprToType(lex, rhsType, CastExpr::CK_BitCast); 5012 return rhsType; 5013 } 5014 } 5015 } 5016 5017 // Handle the case of equivalent AltiVec and GCC vector types 5018 if (lhsType->isVectorType() && rhsType->isVectorType() && 5019 Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5020 ImpCastExprToType(lex, rhsType, CastExpr::CK_BitCast); 5021 return rhsType; 5022 } 5023 5024 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5025 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5026 bool swapped = false; 5027 if (rhsType->isExtVectorType()) { 5028 swapped = true; 5029 std::swap(rex, lex); 5030 std::swap(rhsType, lhsType); 5031 } 5032 5033 // Handle the case of an ext vector and scalar. 5034 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5035 QualType EltTy = LV->getElementType(); 5036 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5037 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5038 ImpCastExprToType(rex, lhsType, CastExpr::CK_IntegralCast); 5039 if (swapped) std::swap(rex, lex); 5040 return lhsType; 5041 } 5042 } 5043 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5044 rhsType->isRealFloatingType()) { 5045 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5046 ImpCastExprToType(rex, lhsType, CastExpr::CK_FloatingCast); 5047 if (swapped) std::swap(rex, lex); 5048 return lhsType; 5049 } 5050 } 5051 } 5052 5053 // Vectors of different size or scalar and non-ext-vector are errors. 5054 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5055 << lex->getType() << rex->getType() 5056 << lex->getSourceRange() << rex->getSourceRange(); 5057 return QualType(); 5058} 5059 5060QualType Sema::CheckMultiplyDivideOperands( 5061 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5062 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5063 return CheckVectorOperands(Loc, lex, rex); 5064 5065 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5066 5067 if (!lex->getType()->isArithmeticType() || 5068 !rex->getType()->isArithmeticType()) 5069 return InvalidOperands(Loc, lex, rex); 5070 5071 // Check for division by zero. 5072 if (isDiv && 5073 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5074 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5075 << rex->getSourceRange()); 5076 5077 return compType; 5078} 5079 5080QualType Sema::CheckRemainderOperands( 5081 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5082 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5083 if (lex->getType()->hasIntegerRepresentation() && 5084 rex->getType()->hasIntegerRepresentation()) 5085 return CheckVectorOperands(Loc, lex, rex); 5086 return InvalidOperands(Loc, lex, rex); 5087 } 5088 5089 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5090 5091 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5092 return InvalidOperands(Loc, lex, rex); 5093 5094 // Check for remainder by zero. 5095 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5096 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5097 << rex->getSourceRange()); 5098 5099 return compType; 5100} 5101 5102QualType Sema::CheckAdditionOperands( // C99 6.5.6 5103 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5104 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5105 QualType compType = CheckVectorOperands(Loc, lex, rex); 5106 if (CompLHSTy) *CompLHSTy = compType; 5107 return compType; 5108 } 5109 5110 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5111 5112 // handle the common case first (both operands are arithmetic). 5113 if (lex->getType()->isArithmeticType() && 5114 rex->getType()->isArithmeticType()) { 5115 if (CompLHSTy) *CompLHSTy = compType; 5116 return compType; 5117 } 5118 5119 // Put any potential pointer into PExp 5120 Expr* PExp = lex, *IExp = rex; 5121 if (IExp->getType()->isAnyPointerType()) 5122 std::swap(PExp, IExp); 5123 5124 if (PExp->getType()->isAnyPointerType()) { 5125 5126 if (IExp->getType()->isIntegerType()) { 5127 QualType PointeeTy = PExp->getType()->getPointeeType(); 5128 5129 // Check for arithmetic on pointers to incomplete types. 5130 if (PointeeTy->isVoidType()) { 5131 if (getLangOptions().CPlusPlus) { 5132 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5133 << lex->getSourceRange() << rex->getSourceRange(); 5134 return QualType(); 5135 } 5136 5137 // GNU extension: arithmetic on pointer to void 5138 Diag(Loc, diag::ext_gnu_void_ptr) 5139 << lex->getSourceRange() << rex->getSourceRange(); 5140 } else if (PointeeTy->isFunctionType()) { 5141 if (getLangOptions().CPlusPlus) { 5142 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5143 << lex->getType() << lex->getSourceRange(); 5144 return QualType(); 5145 } 5146 5147 // GNU extension: arithmetic on pointer to function 5148 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5149 << lex->getType() << lex->getSourceRange(); 5150 } else { 5151 // Check if we require a complete type. 5152 if (((PExp->getType()->isPointerType() && 5153 !PExp->getType()->isDependentType()) || 5154 PExp->getType()->isObjCObjectPointerType()) && 5155 RequireCompleteType(Loc, PointeeTy, 5156 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5157 << PExp->getSourceRange() 5158 << PExp->getType())) 5159 return QualType(); 5160 } 5161 // Diagnose bad cases where we step over interface counts. 5162 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5163 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5164 << PointeeTy << PExp->getSourceRange(); 5165 return QualType(); 5166 } 5167 5168 if (CompLHSTy) { 5169 QualType LHSTy = Context.isPromotableBitField(lex); 5170 if (LHSTy.isNull()) { 5171 LHSTy = lex->getType(); 5172 if (LHSTy->isPromotableIntegerType()) 5173 LHSTy = Context.getPromotedIntegerType(LHSTy); 5174 } 5175 *CompLHSTy = LHSTy; 5176 } 5177 return PExp->getType(); 5178 } 5179 } 5180 5181 return InvalidOperands(Loc, lex, rex); 5182} 5183 5184// C99 6.5.6 5185QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5186 SourceLocation Loc, QualType* CompLHSTy) { 5187 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5188 QualType compType = CheckVectorOperands(Loc, lex, rex); 5189 if (CompLHSTy) *CompLHSTy = compType; 5190 return compType; 5191 } 5192 5193 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5194 5195 // Enforce type constraints: C99 6.5.6p3. 5196 5197 // Handle the common case first (both operands are arithmetic). 5198 if (lex->getType()->isArithmeticType() 5199 && rex->getType()->isArithmeticType()) { 5200 if (CompLHSTy) *CompLHSTy = compType; 5201 return compType; 5202 } 5203 5204 // Either ptr - int or ptr - ptr. 5205 if (lex->getType()->isAnyPointerType()) { 5206 QualType lpointee = lex->getType()->getPointeeType(); 5207 5208 // The LHS must be an completely-defined object type. 5209 5210 bool ComplainAboutVoid = false; 5211 Expr *ComplainAboutFunc = 0; 5212 if (lpointee->isVoidType()) { 5213 if (getLangOptions().CPlusPlus) { 5214 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5215 << lex->getSourceRange() << rex->getSourceRange(); 5216 return QualType(); 5217 } 5218 5219 // GNU C extension: arithmetic on pointer to void 5220 ComplainAboutVoid = true; 5221 } else if (lpointee->isFunctionType()) { 5222 if (getLangOptions().CPlusPlus) { 5223 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5224 << lex->getType() << lex->getSourceRange(); 5225 return QualType(); 5226 } 5227 5228 // GNU C extension: arithmetic on pointer to function 5229 ComplainAboutFunc = lex; 5230 } else if (!lpointee->isDependentType() && 5231 RequireCompleteType(Loc, lpointee, 5232 PDiag(diag::err_typecheck_sub_ptr_object) 5233 << lex->getSourceRange() 5234 << lex->getType())) 5235 return QualType(); 5236 5237 // Diagnose bad cases where we step over interface counts. 5238 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5239 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5240 << lpointee << lex->getSourceRange(); 5241 return QualType(); 5242 } 5243 5244 // The result type of a pointer-int computation is the pointer type. 5245 if (rex->getType()->isIntegerType()) { 5246 if (ComplainAboutVoid) 5247 Diag(Loc, diag::ext_gnu_void_ptr) 5248 << lex->getSourceRange() << rex->getSourceRange(); 5249 if (ComplainAboutFunc) 5250 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5251 << ComplainAboutFunc->getType() 5252 << ComplainAboutFunc->getSourceRange(); 5253 5254 if (CompLHSTy) *CompLHSTy = lex->getType(); 5255 return lex->getType(); 5256 } 5257 5258 // Handle pointer-pointer subtractions. 5259 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5260 QualType rpointee = RHSPTy->getPointeeType(); 5261 5262 // RHS must be a completely-type object type. 5263 // Handle the GNU void* extension. 5264 if (rpointee->isVoidType()) { 5265 if (getLangOptions().CPlusPlus) { 5266 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5267 << lex->getSourceRange() << rex->getSourceRange(); 5268 return QualType(); 5269 } 5270 5271 ComplainAboutVoid = true; 5272 } else if (rpointee->isFunctionType()) { 5273 if (getLangOptions().CPlusPlus) { 5274 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5275 << rex->getType() << rex->getSourceRange(); 5276 return QualType(); 5277 } 5278 5279 // GNU extension: arithmetic on pointer to function 5280 if (!ComplainAboutFunc) 5281 ComplainAboutFunc = rex; 5282 } else if (!rpointee->isDependentType() && 5283 RequireCompleteType(Loc, rpointee, 5284 PDiag(diag::err_typecheck_sub_ptr_object) 5285 << rex->getSourceRange() 5286 << rex->getType())) 5287 return QualType(); 5288 5289 if (getLangOptions().CPlusPlus) { 5290 // Pointee types must be the same: C++ [expr.add] 5291 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5292 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5293 << lex->getType() << rex->getType() 5294 << lex->getSourceRange() << rex->getSourceRange(); 5295 return QualType(); 5296 } 5297 } else { 5298 // Pointee types must be compatible C99 6.5.6p3 5299 if (!Context.typesAreCompatible( 5300 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5301 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5302 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5303 << lex->getType() << rex->getType() 5304 << lex->getSourceRange() << rex->getSourceRange(); 5305 return QualType(); 5306 } 5307 } 5308 5309 if (ComplainAboutVoid) 5310 Diag(Loc, diag::ext_gnu_void_ptr) 5311 << lex->getSourceRange() << rex->getSourceRange(); 5312 if (ComplainAboutFunc) 5313 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5314 << ComplainAboutFunc->getType() 5315 << ComplainAboutFunc->getSourceRange(); 5316 5317 if (CompLHSTy) *CompLHSTy = lex->getType(); 5318 return Context.getPointerDiffType(); 5319 } 5320 } 5321 5322 return InvalidOperands(Loc, lex, rex); 5323} 5324 5325// C99 6.5.7 5326QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5327 bool isCompAssign) { 5328 // C99 6.5.7p2: Each of the operands shall have integer type. 5329 if (!lex->getType()->hasIntegerRepresentation() || 5330 !rex->getType()->hasIntegerRepresentation()) 5331 return InvalidOperands(Loc, lex, rex); 5332 5333 // Vector shifts promote their scalar inputs to vector type. 5334 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5335 return CheckVectorOperands(Loc, lex, rex); 5336 5337 // Shifts don't perform usual arithmetic conversions, they just do integer 5338 // promotions on each operand. C99 6.5.7p3 5339 QualType LHSTy = Context.isPromotableBitField(lex); 5340 if (LHSTy.isNull()) { 5341 LHSTy = lex->getType(); 5342 if (LHSTy->isPromotableIntegerType()) 5343 LHSTy = Context.getPromotedIntegerType(LHSTy); 5344 } 5345 if (!isCompAssign) 5346 ImpCastExprToType(lex, LHSTy, CastExpr::CK_IntegralCast); 5347 5348 UsualUnaryConversions(rex); 5349 5350 // Sanity-check shift operands 5351 llvm::APSInt Right; 5352 // Check right/shifter operand 5353 if (!rex->isValueDependent() && 5354 rex->isIntegerConstantExpr(Right, Context)) { 5355 if (Right.isNegative()) 5356 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5357 else { 5358 llvm::APInt LeftBits(Right.getBitWidth(), 5359 Context.getTypeSize(lex->getType())); 5360 if (Right.uge(LeftBits)) 5361 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5362 } 5363 } 5364 5365 // "The type of the result is that of the promoted left operand." 5366 return LHSTy; 5367} 5368 5369static bool IsWithinTemplateSpecialization(Decl *D) { 5370 if (DeclContext *DC = D->getDeclContext()) { 5371 if (isa<ClassTemplateSpecializationDecl>(DC)) 5372 return true; 5373 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 5374 return FD->isFunctionTemplateSpecialization(); 5375 } 5376 return false; 5377} 5378 5379// C99 6.5.8, C++ [expr.rel] 5380QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5381 unsigned OpaqueOpc, bool isRelational) { 5382 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)OpaqueOpc; 5383 5384 // Handle vector comparisons separately. 5385 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5386 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5387 5388 QualType lType = lex->getType(); 5389 QualType rType = rex->getType(); 5390 5391 if (!lType->hasFloatingRepresentation() && 5392 !(lType->isBlockPointerType() && isRelational)) { 5393 // For non-floating point types, check for self-comparisons of the form 5394 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5395 // often indicate logic errors in the program. 5396 // 5397 // NOTE: Don't warn about comparison expressions resulting from macro 5398 // expansion. Also don't warn about comparisons which are only self 5399 // comparisons within a template specialization. The warnings should catch 5400 // obvious cases in the definition of the template anyways. The idea is to 5401 // warn when the typed comparison operator will always evaluate to the same 5402 // result. 5403 Expr *LHSStripped = lex->IgnoreParens(); 5404 Expr *RHSStripped = rex->IgnoreParens(); 5405 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 5406 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 5407 if (DRL->getDecl() == DRR->getDecl() && !Loc.isMacroID() && 5408 !IsWithinTemplateSpecialization(DRL->getDecl())) { 5409 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5410 << 0 // self- 5411 << (Opc == BinaryOperator::EQ 5412 || Opc == BinaryOperator::LE 5413 || Opc == BinaryOperator::GE)); 5414 } else if (lType->isArrayType() && rType->isArrayType() && 5415 !DRL->getDecl()->getType()->isReferenceType() && 5416 !DRR->getDecl()->getType()->isReferenceType()) { 5417 // what is it always going to eval to? 5418 char always_evals_to; 5419 switch(Opc) { 5420 case BinaryOperator::EQ: // e.g. array1 == array2 5421 always_evals_to = 0; // false 5422 break; 5423 case BinaryOperator::NE: // e.g. array1 != array2 5424 always_evals_to = 1; // true 5425 break; 5426 default: 5427 // best we can say is 'a constant' 5428 always_evals_to = 2; // e.g. array1 <= array2 5429 break; 5430 } 5431 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5432 << 1 // array 5433 << always_evals_to); 5434 } 5435 } 5436 } 5437 5438 if (isa<CastExpr>(LHSStripped)) 5439 LHSStripped = LHSStripped->IgnoreParenCasts(); 5440 if (isa<CastExpr>(RHSStripped)) 5441 RHSStripped = RHSStripped->IgnoreParenCasts(); 5442 5443 // Warn about comparisons against a string constant (unless the other 5444 // operand is null), the user probably wants strcmp. 5445 Expr *literalString = 0; 5446 Expr *literalStringStripped = 0; 5447 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5448 !RHSStripped->isNullPointerConstant(Context, 5449 Expr::NPC_ValueDependentIsNull)) { 5450 literalString = lex; 5451 literalStringStripped = LHSStripped; 5452 } else if ((isa<StringLiteral>(RHSStripped) || 5453 isa<ObjCEncodeExpr>(RHSStripped)) && 5454 !LHSStripped->isNullPointerConstant(Context, 5455 Expr::NPC_ValueDependentIsNull)) { 5456 literalString = rex; 5457 literalStringStripped = RHSStripped; 5458 } 5459 5460 if (literalString) { 5461 std::string resultComparison; 5462 switch (Opc) { 5463 case BinaryOperator::LT: resultComparison = ") < 0"; break; 5464 case BinaryOperator::GT: resultComparison = ") > 0"; break; 5465 case BinaryOperator::LE: resultComparison = ") <= 0"; break; 5466 case BinaryOperator::GE: resultComparison = ") >= 0"; break; 5467 case BinaryOperator::EQ: resultComparison = ") == 0"; break; 5468 case BinaryOperator::NE: resultComparison = ") != 0"; break; 5469 default: assert(false && "Invalid comparison operator"); 5470 } 5471 5472 DiagRuntimeBehavior(Loc, 5473 PDiag(diag::warn_stringcompare) 5474 << isa<ObjCEncodeExpr>(literalStringStripped) 5475 << literalString->getSourceRange()); 5476 } 5477 } 5478 5479 // C99 6.5.8p3 / C99 6.5.9p4 5480 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5481 UsualArithmeticConversions(lex, rex); 5482 else { 5483 UsualUnaryConversions(lex); 5484 UsualUnaryConversions(rex); 5485 } 5486 5487 lType = lex->getType(); 5488 rType = rex->getType(); 5489 5490 // The result of comparisons is 'bool' in C++, 'int' in C. 5491 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5492 5493 if (isRelational) { 5494 if (lType->isRealType() && rType->isRealType()) 5495 return ResultTy; 5496 } else { 5497 // Check for comparisons of floating point operands using != and ==. 5498 if (lType->hasFloatingRepresentation()) 5499 CheckFloatComparison(Loc,lex,rex); 5500 5501 if (lType->isArithmeticType() && rType->isArithmeticType()) 5502 return ResultTy; 5503 } 5504 5505 bool LHSIsNull = lex->isNullPointerConstant(Context, 5506 Expr::NPC_ValueDependentIsNull); 5507 bool RHSIsNull = rex->isNullPointerConstant(Context, 5508 Expr::NPC_ValueDependentIsNull); 5509 5510 // All of the following pointer-related warnings are GCC extensions, except 5511 // when handling null pointer constants. 5512 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5513 QualType LCanPointeeTy = 5514 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5515 QualType RCanPointeeTy = 5516 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5517 5518 if (getLangOptions().CPlusPlus) { 5519 if (LCanPointeeTy == RCanPointeeTy) 5520 return ResultTy; 5521 if (!isRelational && 5522 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5523 // Valid unless comparison between non-null pointer and function pointer 5524 // This is a gcc extension compatibility comparison. 5525 // In a SFINAE context, we treat this as a hard error to maintain 5526 // conformance with the C++ standard. 5527 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5528 && !LHSIsNull && !RHSIsNull) { 5529 Diag(Loc, 5530 isSFINAEContext()? 5531 diag::err_typecheck_comparison_of_fptr_to_void 5532 : diag::ext_typecheck_comparison_of_fptr_to_void) 5533 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5534 5535 if (isSFINAEContext()) 5536 return QualType(); 5537 5538 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5539 return ResultTy; 5540 } 5541 } 5542 // C++ [expr.rel]p2: 5543 // [...] Pointer conversions (4.10) and qualification 5544 // conversions (4.4) are performed on pointer operands (or on 5545 // a pointer operand and a null pointer constant) to bring 5546 // them to their composite pointer type. [...] 5547 // 5548 // C++ [expr.eq]p1 uses the same notion for (in)equality 5549 // comparisons of pointers. 5550 bool NonStandardCompositeType = false; 5551 QualType T = FindCompositePointerType(Loc, lex, rex, 5552 isSFINAEContext()? 0 : &NonStandardCompositeType); 5553 if (T.isNull()) { 5554 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5555 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5556 return QualType(); 5557 } else if (NonStandardCompositeType) { 5558 Diag(Loc, 5559 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5560 << lType << rType << T 5561 << lex->getSourceRange() << rex->getSourceRange(); 5562 } 5563 5564 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5565 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5566 return ResultTy; 5567 } 5568 // C99 6.5.9p2 and C99 6.5.8p2 5569 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5570 RCanPointeeTy.getUnqualifiedType())) { 5571 // Valid unless a relational comparison of function pointers 5572 if (isRelational && LCanPointeeTy->isFunctionType()) { 5573 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5574 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5575 } 5576 } else if (!isRelational && 5577 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5578 // Valid unless comparison between non-null pointer and function pointer 5579 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5580 && !LHSIsNull && !RHSIsNull) { 5581 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5582 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5583 } 5584 } else { 5585 // Invalid 5586 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5587 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5588 } 5589 if (LCanPointeeTy != RCanPointeeTy) 5590 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5591 return ResultTy; 5592 } 5593 5594 if (getLangOptions().CPlusPlus) { 5595 // Comparison of pointers with null pointer constants and equality 5596 // comparisons of member pointers to null pointer constants. 5597 if (RHSIsNull && 5598 (lType->isPointerType() || 5599 (!isRelational && lType->isMemberPointerType()))) { 5600 ImpCastExprToType(rex, lType, 5601 lType->isMemberPointerType() 5602 ? CastExpr::CK_NullToMemberPointer 5603 : CastExpr::CK_IntegralToPointer); 5604 return ResultTy; 5605 } 5606 if (LHSIsNull && 5607 (rType->isPointerType() || 5608 (!isRelational && rType->isMemberPointerType()))) { 5609 ImpCastExprToType(lex, rType, 5610 rType->isMemberPointerType() 5611 ? CastExpr::CK_NullToMemberPointer 5612 : CastExpr::CK_IntegralToPointer); 5613 return ResultTy; 5614 } 5615 5616 // Comparison of member pointers. 5617 if (!isRelational && 5618 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5619 // C++ [expr.eq]p2: 5620 // In addition, pointers to members can be compared, or a pointer to 5621 // member and a null pointer constant. Pointer to member conversions 5622 // (4.11) and qualification conversions (4.4) are performed to bring 5623 // them to a common type. If one operand is a null pointer constant, 5624 // the common type is the type of the other operand. Otherwise, the 5625 // common type is a pointer to member type similar (4.4) to the type 5626 // of one of the operands, with a cv-qualification signature (4.4) 5627 // that is the union of the cv-qualification signatures of the operand 5628 // types. 5629 bool NonStandardCompositeType = false; 5630 QualType T = FindCompositePointerType(Loc, lex, rex, 5631 isSFINAEContext()? 0 : &NonStandardCompositeType); 5632 if (T.isNull()) { 5633 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5634 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5635 return QualType(); 5636 } else if (NonStandardCompositeType) { 5637 Diag(Loc, 5638 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5639 << lType << rType << T 5640 << lex->getSourceRange() << rex->getSourceRange(); 5641 } 5642 5643 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5644 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5645 return ResultTy; 5646 } 5647 5648 // Comparison of nullptr_t with itself. 5649 if (lType->isNullPtrType() && rType->isNullPtrType()) 5650 return ResultTy; 5651 } 5652 5653 // Handle block pointer types. 5654 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5655 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5656 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5657 5658 if (!LHSIsNull && !RHSIsNull && 5659 !Context.typesAreCompatible(lpointee, rpointee)) { 5660 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5661 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5662 } 5663 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5664 return ResultTy; 5665 } 5666 // Allow block pointers to be compared with null pointer constants. 5667 if (!isRelational 5668 && ((lType->isBlockPointerType() && rType->isPointerType()) 5669 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5670 if (!LHSIsNull && !RHSIsNull) { 5671 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5672 ->getPointeeType()->isVoidType()) 5673 || (lType->isPointerType() && lType->getAs<PointerType>() 5674 ->getPointeeType()->isVoidType()))) 5675 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5676 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5677 } 5678 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5679 return ResultTy; 5680 } 5681 5682 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5683 if (lType->isPointerType() || rType->isPointerType()) { 5684 const PointerType *LPT = lType->getAs<PointerType>(); 5685 const PointerType *RPT = rType->getAs<PointerType>(); 5686 bool LPtrToVoid = LPT ? 5687 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5688 bool RPtrToVoid = RPT ? 5689 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5690 5691 if (!LPtrToVoid && !RPtrToVoid && 5692 !Context.typesAreCompatible(lType, rType)) { 5693 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5694 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5695 } 5696 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5697 return ResultTy; 5698 } 5699 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5700 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5701 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5702 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5703 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5704 return ResultTy; 5705 } 5706 } 5707 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 5708 (lType->isIntegerType() && rType->isAnyPointerType())) { 5709 unsigned DiagID = 0; 5710 bool isError = false; 5711 if ((LHSIsNull && lType->isIntegerType()) || 5712 (RHSIsNull && rType->isIntegerType())) { 5713 if (isRelational && !getLangOptions().CPlusPlus) 5714 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5715 } else if (isRelational && !getLangOptions().CPlusPlus) 5716 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5717 else if (getLangOptions().CPlusPlus) { 5718 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 5719 isError = true; 5720 } else 5721 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5722 5723 if (DiagID) { 5724 Diag(Loc, DiagID) 5725 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5726 if (isError) 5727 return QualType(); 5728 } 5729 5730 if (lType->isIntegerType()) 5731 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5732 else 5733 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5734 return ResultTy; 5735 } 5736 5737 // Handle block pointers. 5738 if (!isRelational && RHSIsNull 5739 && lType->isBlockPointerType() && rType->isIntegerType()) { 5740 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5741 return ResultTy; 5742 } 5743 if (!isRelational && LHSIsNull 5744 && lType->isIntegerType() && rType->isBlockPointerType()) { 5745 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5746 return ResultTy; 5747 } 5748 return InvalidOperands(Loc, lex, rex); 5749} 5750 5751/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5752/// operates on extended vector types. Instead of producing an IntTy result, 5753/// like a scalar comparison, a vector comparison produces a vector of integer 5754/// types. 5755QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5756 SourceLocation Loc, 5757 bool isRelational) { 5758 // Check to make sure we're operating on vectors of the same type and width, 5759 // Allowing one side to be a scalar of element type. 5760 QualType vType = CheckVectorOperands(Loc, lex, rex); 5761 if (vType.isNull()) 5762 return vType; 5763 5764 QualType lType = lex->getType(); 5765 QualType rType = rex->getType(); 5766 5767 // For non-floating point types, check for self-comparisons of the form 5768 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5769 // often indicate logic errors in the program. 5770 if (!lType->hasFloatingRepresentation()) { 5771 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5772 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5773 if (DRL->getDecl() == DRR->getDecl()) 5774 DiagRuntimeBehavior(Loc, 5775 PDiag(diag::warn_comparison_always) 5776 << 0 // self- 5777 << 2 // "a constant" 5778 ); 5779 } 5780 5781 // Check for comparisons of floating point operands using != and ==. 5782 if (!isRelational && lType->hasFloatingRepresentation()) { 5783 assert (rType->hasFloatingRepresentation()); 5784 CheckFloatComparison(Loc,lex,rex); 5785 } 5786 5787 // Return the type for the comparison, which is the same as vector type for 5788 // integer vectors, or an integer type of identical size and number of 5789 // elements for floating point vectors. 5790 if (lType->hasIntegerRepresentation()) 5791 return lType; 5792 5793 const VectorType *VTy = lType->getAs<VectorType>(); 5794 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5795 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5796 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5797 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5798 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5799 5800 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5801 "Unhandled vector element size in vector compare"); 5802 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5803} 5804 5805inline QualType Sema::CheckBitwiseOperands( 5806 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5807 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5808 if (lex->getType()->hasIntegerRepresentation() && 5809 rex->getType()->hasIntegerRepresentation()) 5810 return CheckVectorOperands(Loc, lex, rex); 5811 5812 return InvalidOperands(Loc, lex, rex); 5813 } 5814 5815 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5816 5817 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5818 return compType; 5819 return InvalidOperands(Loc, lex, rex); 5820} 5821 5822inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5823 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 5824 5825 // Diagnose cases where the user write a logical and/or but probably meant a 5826 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 5827 // is a constant. 5828 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 5829 rex->getType()->isIntegerType() && !rex->isValueDependent() && 5830 // Don't warn in macros. 5831 !Loc.isMacroID()) { 5832 // If the RHS can be constant folded, and if it constant folds to something 5833 // that isn't 0 or 1 (which indicate a potential logical operation that 5834 // happened to fold to true/false) then warn. 5835 Expr::EvalResult Result; 5836 if (rex->Evaluate(Result, Context) && !Result.HasSideEffects && 5837 Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { 5838 Diag(Loc, diag::warn_logical_instead_of_bitwise) 5839 << rex->getSourceRange() 5840 << (Opc == BinaryOperator::LAnd ? "&&" : "||") 5841 << (Opc == BinaryOperator::LAnd ? "&" : "|"); 5842 } 5843 } 5844 5845 if (!Context.getLangOptions().CPlusPlus) { 5846 UsualUnaryConversions(lex); 5847 UsualUnaryConversions(rex); 5848 5849 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5850 return InvalidOperands(Loc, lex, rex); 5851 5852 return Context.IntTy; 5853 } 5854 5855 // The following is safe because we only use this method for 5856 // non-overloadable operands. 5857 5858 // C++ [expr.log.and]p1 5859 // C++ [expr.log.or]p1 5860 // The operands are both contextually converted to type bool. 5861 if (PerformContextuallyConvertToBool(lex) || 5862 PerformContextuallyConvertToBool(rex)) 5863 return InvalidOperands(Loc, lex, rex); 5864 5865 // C++ [expr.log.and]p2 5866 // C++ [expr.log.or]p2 5867 // The result is a bool. 5868 return Context.BoolTy; 5869} 5870 5871/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5872/// is a read-only property; return true if so. A readonly property expression 5873/// depends on various declarations and thus must be treated specially. 5874/// 5875static bool IsReadonlyProperty(Expr *E, Sema &S) { 5876 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5877 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5878 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5879 QualType BaseType = PropExpr->getBase()->getType(); 5880 if (const ObjCObjectPointerType *OPT = 5881 BaseType->getAsObjCInterfacePointerType()) 5882 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5883 if (S.isPropertyReadonly(PDecl, IFace)) 5884 return true; 5885 } 5886 } 5887 return false; 5888} 5889 5890/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5891/// emit an error and return true. If so, return false. 5892static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5893 SourceLocation OrigLoc = Loc; 5894 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5895 &Loc); 5896 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5897 IsLV = Expr::MLV_ReadonlyProperty; 5898 if (IsLV == Expr::MLV_Valid) 5899 return false; 5900 5901 unsigned Diag = 0; 5902 bool NeedType = false; 5903 switch (IsLV) { // C99 6.5.16p2 5904 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5905 case Expr::MLV_ArrayType: 5906 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5907 NeedType = true; 5908 break; 5909 case Expr::MLV_NotObjectType: 5910 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5911 NeedType = true; 5912 break; 5913 case Expr::MLV_LValueCast: 5914 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5915 break; 5916 case Expr::MLV_Valid: 5917 llvm_unreachable("did not take early return for MLV_Valid"); 5918 case Expr::MLV_InvalidExpression: 5919 case Expr::MLV_MemberFunction: 5920 case Expr::MLV_ClassTemporary: 5921 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5922 break; 5923 case Expr::MLV_IncompleteType: 5924 case Expr::MLV_IncompleteVoidType: 5925 return S.RequireCompleteType(Loc, E->getType(), 5926 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5927 << E->getSourceRange()); 5928 case Expr::MLV_DuplicateVectorComponents: 5929 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5930 break; 5931 case Expr::MLV_NotBlockQualified: 5932 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5933 break; 5934 case Expr::MLV_ReadonlyProperty: 5935 Diag = diag::error_readonly_property_assignment; 5936 break; 5937 case Expr::MLV_NoSetterProperty: 5938 Diag = diag::error_nosetter_property_assignment; 5939 break; 5940 case Expr::MLV_SubObjCPropertySetting: 5941 Diag = diag::error_no_subobject_property_setting; 5942 break; 5943 } 5944 5945 SourceRange Assign; 5946 if (Loc != OrigLoc) 5947 Assign = SourceRange(OrigLoc, OrigLoc); 5948 if (NeedType) 5949 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5950 else 5951 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5952 return true; 5953} 5954 5955 5956 5957// C99 6.5.16.1 5958QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5959 SourceLocation Loc, 5960 QualType CompoundType) { 5961 // Verify that LHS is a modifiable lvalue, and emit error if not. 5962 if (CheckForModifiableLvalue(LHS, Loc, *this)) 5963 return QualType(); 5964 5965 QualType LHSType = LHS->getType(); 5966 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 5967 AssignConvertType ConvTy; 5968 if (CompoundType.isNull()) { 5969 QualType LHSTy(LHSType); 5970 // Simple assignment "x = y". 5971 if (const ObjCImplicitSetterGetterRefExpr *OISGE = 5972 dyn_cast<ObjCImplicitSetterGetterRefExpr>(LHS)) { 5973 // If using property-dot syntax notation for assignment, and there is a 5974 // setter, RHS expression is being passed to the setter argument. So, 5975 // type conversion (and comparison) is RHS to setter's argument type. 5976 if (const ObjCMethodDecl *SetterMD = OISGE->getSetterMethod()) { 5977 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 5978 LHSTy = (*P)->getType(); 5979 } 5980 } 5981 5982 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 5983 // Special case of NSObject attributes on c-style pointer types. 5984 if (ConvTy == IncompatiblePointer && 5985 ((Context.isObjCNSObjectType(LHSType) && 5986 RHSType->isObjCObjectPointerType()) || 5987 (Context.isObjCNSObjectType(RHSType) && 5988 LHSType->isObjCObjectPointerType()))) 5989 ConvTy = Compatible; 5990 5991 // If the RHS is a unary plus or minus, check to see if they = and + are 5992 // right next to each other. If so, the user may have typo'd "x =+ 4" 5993 // instead of "x += 4". 5994 Expr *RHSCheck = RHS; 5995 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 5996 RHSCheck = ICE->getSubExpr(); 5997 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 5998 if ((UO->getOpcode() == UnaryOperator::Plus || 5999 UO->getOpcode() == UnaryOperator::Minus) && 6000 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 6001 // Only if the two operators are exactly adjacent. 6002 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 6003 // And there is a space or other character before the subexpr of the 6004 // unary +/-. We don't want to warn on "x=-1". 6005 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 6006 UO->getSubExpr()->getLocStart().isFileID()) { 6007 Diag(Loc, diag::warn_not_compound_assign) 6008 << (UO->getOpcode() == UnaryOperator::Plus ? "+" : "-") 6009 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 6010 } 6011 } 6012 } else { 6013 // Compound assignment "x += y" 6014 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 6015 } 6016 6017 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 6018 RHS, AA_Assigning)) 6019 return QualType(); 6020 6021 6022 // Check to see if the destination operand is a dereferenced null pointer. If 6023 // so, and if not volatile-qualified, this is undefined behavior that the 6024 // optimizer will delete, so warn about it. People sometimes try to use this 6025 // to get a deterministic trap and are surprised by clang's behavior. This 6026 // only handles the pattern "*null = whatever", which is a very syntactic 6027 // check. 6028 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 6029 if (UO->getOpcode() == UnaryOperator::Deref && 6030 UO->getSubExpr()->IgnoreParenCasts()-> 6031 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 6032 !UO->getType().isVolatileQualified()) { 6033 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 6034 << UO->getSubExpr()->getSourceRange(); 6035 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 6036 } 6037 6038 // C99 6.5.16p3: The type of an assignment expression is the type of the 6039 // left operand unless the left operand has qualified type, in which case 6040 // it is the unqualified version of the type of the left operand. 6041 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 6042 // is converted to the type of the assignment expression (above). 6043 // C++ 5.17p1: the type of the assignment expression is that of its left 6044 // operand. 6045 return LHSType.getUnqualifiedType(); 6046} 6047 6048// C99 6.5.17 6049QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 6050 DiagnoseUnusedExprResult(LHS); 6051 6052 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 6053 // C++ does not perform this conversion (C++ [expr.comma]p1). 6054 if (!getLangOptions().CPlusPlus) 6055 DefaultFunctionArrayLvalueConversion(RHS); 6056 6057 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 6058 // incomplete in C++). 6059 6060 return RHS->getType(); 6061} 6062 6063/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 6064/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 6065QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 6066 bool isInc, bool isPrefix) { 6067 if (Op->isTypeDependent()) 6068 return Context.DependentTy; 6069 6070 QualType ResType = Op->getType(); 6071 assert(!ResType.isNull() && "no type for increment/decrement expression"); 6072 6073 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 6074 // Decrement of bool is not allowed. 6075 if (!isInc) { 6076 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 6077 return QualType(); 6078 } 6079 // Increment of bool sets it to true, but is deprecated. 6080 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 6081 } else if (ResType->isRealType()) { 6082 // OK! 6083 } else if (ResType->isAnyPointerType()) { 6084 QualType PointeeTy = ResType->getPointeeType(); 6085 6086 // C99 6.5.2.4p2, 6.5.6p2 6087 if (PointeeTy->isVoidType()) { 6088 if (getLangOptions().CPlusPlus) { 6089 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 6090 << Op->getSourceRange(); 6091 return QualType(); 6092 } 6093 6094 // Pointer to void is a GNU extension in C. 6095 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 6096 } else if (PointeeTy->isFunctionType()) { 6097 if (getLangOptions().CPlusPlus) { 6098 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 6099 << Op->getType() << Op->getSourceRange(); 6100 return QualType(); 6101 } 6102 6103 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 6104 << ResType << Op->getSourceRange(); 6105 } else if (RequireCompleteType(OpLoc, PointeeTy, 6106 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6107 << Op->getSourceRange() 6108 << ResType)) 6109 return QualType(); 6110 // Diagnose bad cases where we step over interface counts. 6111 else if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6112 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6113 << PointeeTy << Op->getSourceRange(); 6114 return QualType(); 6115 } 6116 } else if (ResType->isAnyComplexType()) { 6117 // C99 does not support ++/-- on complex types, we allow as an extension. 6118 Diag(OpLoc, diag::ext_integer_increment_complex) 6119 << ResType << Op->getSourceRange(); 6120 } else { 6121 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6122 << ResType << int(isInc) << Op->getSourceRange(); 6123 return QualType(); 6124 } 6125 // At this point, we know we have a real, complex or pointer type. 6126 // Now make sure the operand is a modifiable lvalue. 6127 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6128 return QualType(); 6129 // In C++, a prefix increment is the same type as the operand. Otherwise 6130 // (in C or with postfix), the increment is the unqualified type of the 6131 // operand. 6132 return isPrefix && getLangOptions().CPlusPlus 6133 ? ResType : ResType.getUnqualifiedType(); 6134} 6135 6136/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6137/// This routine allows us to typecheck complex/recursive expressions 6138/// where the declaration is needed for type checking. We only need to 6139/// handle cases when the expression references a function designator 6140/// or is an lvalue. Here are some examples: 6141/// - &(x) => x 6142/// - &*****f => f for f a function designator. 6143/// - &s.xx => s 6144/// - &s.zz[1].yy -> s, if zz is an array 6145/// - *(x + 1) -> x, if x is an array 6146/// - &"123"[2] -> 0 6147/// - & __real__ x -> x 6148static NamedDecl *getPrimaryDecl(Expr *E) { 6149 switch (E->getStmtClass()) { 6150 case Stmt::DeclRefExprClass: 6151 return cast<DeclRefExpr>(E)->getDecl(); 6152 case Stmt::MemberExprClass: 6153 // If this is an arrow operator, the address is an offset from 6154 // the base's value, so the object the base refers to is 6155 // irrelevant. 6156 if (cast<MemberExpr>(E)->isArrow()) 6157 return 0; 6158 // Otherwise, the expression refers to a part of the base 6159 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6160 case Stmt::ArraySubscriptExprClass: { 6161 // FIXME: This code shouldn't be necessary! We should catch the implicit 6162 // promotion of register arrays earlier. 6163 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6164 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6165 if (ICE->getSubExpr()->getType()->isArrayType()) 6166 return getPrimaryDecl(ICE->getSubExpr()); 6167 } 6168 return 0; 6169 } 6170 case Stmt::UnaryOperatorClass: { 6171 UnaryOperator *UO = cast<UnaryOperator>(E); 6172 6173 switch(UO->getOpcode()) { 6174 case UnaryOperator::Real: 6175 case UnaryOperator::Imag: 6176 case UnaryOperator::Extension: 6177 return getPrimaryDecl(UO->getSubExpr()); 6178 default: 6179 return 0; 6180 } 6181 } 6182 case Stmt::ParenExprClass: 6183 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6184 case Stmt::ImplicitCastExprClass: 6185 // If the result of an implicit cast is an l-value, we care about 6186 // the sub-expression; otherwise, the result here doesn't matter. 6187 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6188 default: 6189 return 0; 6190 } 6191} 6192 6193/// CheckAddressOfOperand - The operand of & must be either a function 6194/// designator or an lvalue designating an object. If it is an lvalue, the 6195/// object cannot be declared with storage class register or be a bit field. 6196/// Note: The usual conversions are *not* applied to the operand of the & 6197/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6198/// In C++, the operand might be an overloaded function name, in which case 6199/// we allow the '&' but retain the overloaded-function type. 6200QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) { 6201 // Make sure to ignore parentheses in subsequent checks 6202 op = op->IgnoreParens(); 6203 6204 if (op->isTypeDependent()) 6205 return Context.DependentTy; 6206 6207 if (getLangOptions().C99) { 6208 // Implement C99-only parts of addressof rules. 6209 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6210 if (uOp->getOpcode() == UnaryOperator::Deref) 6211 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6212 // (assuming the deref expression is valid). 6213 return uOp->getSubExpr()->getType(); 6214 } 6215 // Technically, there should be a check for array subscript 6216 // expressions here, but the result of one is always an lvalue anyway. 6217 } 6218 NamedDecl *dcl = getPrimaryDecl(op); 6219 Expr::isLvalueResult lval = op->isLvalue(Context); 6220 6221 MemberExpr *ME = dyn_cast<MemberExpr>(op); 6222 if (lval == Expr::LV_MemberFunction && ME && 6223 isa<CXXMethodDecl>(ME->getMemberDecl())) { 6224 ValueDecl *dcl = cast<MemberExpr>(op)->getMemberDecl(); 6225 // &f where f is a member of the current object, or &o.f, or &p->f 6226 // All these are not allowed, and we need to catch them before the dcl 6227 // branch of the if, below. 6228 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6229 << dcl; 6230 // FIXME: Improve this diagnostic and provide a fixit. 6231 6232 // Now recover by acting as if the function had been accessed qualified. 6233 return Context.getMemberPointerType(op->getType(), 6234 Context.getTypeDeclType(cast<RecordDecl>(dcl->getDeclContext())) 6235 .getTypePtr()); 6236 } 6237 6238 if (lval == Expr::LV_ClassTemporary) { 6239 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6240 : diag::ext_typecheck_addrof_class_temporary) 6241 << op->getType() << op->getSourceRange(); 6242 if (isSFINAEContext()) 6243 return QualType(); 6244 } else if (isa<ObjCSelectorExpr>(op)) 6245 return Context.getPointerType(op->getType()); 6246 else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6247 // C99 6.5.3.2p1 6248 // The operand must be either an l-value or a function designator 6249 if (!op->getType()->isFunctionType()) { 6250 // FIXME: emit more specific diag... 6251 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6252 << op->getSourceRange(); 6253 return QualType(); 6254 } 6255 } else if (op->getBitField()) { // C99 6.5.3.2p1 6256 // The operand cannot be a bit-field 6257 Diag(OpLoc, diag::err_typecheck_address_of) 6258 << "bit-field" << op->getSourceRange(); 6259 return QualType(); 6260 } else if (op->refersToVectorElement()) { 6261 // The operand cannot be an element of a vector 6262 Diag(OpLoc, diag::err_typecheck_address_of) 6263 << "vector element" << op->getSourceRange(); 6264 return QualType(); 6265 } else if (isa<ObjCPropertyRefExpr>(op)) { 6266 // cannot take address of a property expression. 6267 Diag(OpLoc, diag::err_typecheck_address_of) 6268 << "property expression" << op->getSourceRange(); 6269 return QualType(); 6270 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6271 // FIXME: Can LHS ever be null here? 6272 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6273 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6274 } else if (isa<OverloadExpr>(op)) { 6275 return Context.OverloadTy; 6276 } else if (dcl) { // C99 6.5.3.2p1 6277 // We have an lvalue with a decl. Make sure the decl is not declared 6278 // with the register storage-class specifier. 6279 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6280 if (vd->getStorageClass() == VarDecl::Register) { 6281 Diag(OpLoc, diag::err_typecheck_address_of) 6282 << "register variable" << op->getSourceRange(); 6283 return QualType(); 6284 } 6285 } else if (isa<FunctionTemplateDecl>(dcl)) { 6286 return Context.OverloadTy; 6287 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6288 // Okay: we can take the address of a field. 6289 // Could be a pointer to member, though, if there is an explicit 6290 // scope qualifier for the class. 6291 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6292 DeclContext *Ctx = dcl->getDeclContext(); 6293 if (Ctx && Ctx->isRecord()) { 6294 if (FD->getType()->isReferenceType()) { 6295 Diag(OpLoc, 6296 diag::err_cannot_form_pointer_to_member_of_reference_type) 6297 << FD->getDeclName() << FD->getType(); 6298 return QualType(); 6299 } 6300 6301 return Context.getMemberPointerType(op->getType(), 6302 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6303 } 6304 } 6305 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(dcl)) { 6306 // Okay: we can take the address of a function. 6307 // As above. 6308 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier() && 6309 MD->isInstance()) 6310 return Context.getMemberPointerType(op->getType(), 6311 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6312 } else if (!isa<FunctionDecl>(dcl)) 6313 assert(0 && "Unknown/unexpected decl type"); 6314 } 6315 6316 if (lval == Expr::LV_IncompleteVoidType) { 6317 // Taking the address of a void variable is technically illegal, but we 6318 // allow it in cases which are otherwise valid. 6319 // Example: "extern void x; void* y = &x;". 6320 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6321 } 6322 6323 // If the operand has type "type", the result has type "pointer to type". 6324 if (op->getType()->isObjCObjectType()) 6325 return Context.getObjCObjectPointerType(op->getType()); 6326 return Context.getPointerType(op->getType()); 6327} 6328 6329/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 6330QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6331 if (Op->isTypeDependent()) 6332 return Context.DependentTy; 6333 6334 UsualUnaryConversions(Op); 6335 QualType OpTy = Op->getType(); 6336 QualType Result; 6337 6338 // Note that per both C89 and C99, indirection is always legal, even if OpTy 6339 // is an incomplete type or void. It would be possible to warn about 6340 // dereferencing a void pointer, but it's completely well-defined, and such a 6341 // warning is unlikely to catch any mistakes. 6342 if (const PointerType *PT = OpTy->getAs<PointerType>()) 6343 Result = PT->getPointeeType(); 6344 else if (const ObjCObjectPointerType *OPT = 6345 OpTy->getAs<ObjCObjectPointerType>()) 6346 Result = OPT->getPointeeType(); 6347 6348 if (Result.isNull()) { 6349 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6350 << OpTy << Op->getSourceRange(); 6351 return QualType(); 6352 } 6353 6354 return Result; 6355} 6356 6357static inline BinaryOperator::Opcode ConvertTokenKindToBinaryOpcode( 6358 tok::TokenKind Kind) { 6359 BinaryOperator::Opcode Opc; 6360 switch (Kind) { 6361 default: assert(0 && "Unknown binop!"); 6362 case tok::periodstar: Opc = BinaryOperator::PtrMemD; break; 6363 case tok::arrowstar: Opc = BinaryOperator::PtrMemI; break; 6364 case tok::star: Opc = BinaryOperator::Mul; break; 6365 case tok::slash: Opc = BinaryOperator::Div; break; 6366 case tok::percent: Opc = BinaryOperator::Rem; break; 6367 case tok::plus: Opc = BinaryOperator::Add; break; 6368 case tok::minus: Opc = BinaryOperator::Sub; break; 6369 case tok::lessless: Opc = BinaryOperator::Shl; break; 6370 case tok::greatergreater: Opc = BinaryOperator::Shr; break; 6371 case tok::lessequal: Opc = BinaryOperator::LE; break; 6372 case tok::less: Opc = BinaryOperator::LT; break; 6373 case tok::greaterequal: Opc = BinaryOperator::GE; break; 6374 case tok::greater: Opc = BinaryOperator::GT; break; 6375 case tok::exclaimequal: Opc = BinaryOperator::NE; break; 6376 case tok::equalequal: Opc = BinaryOperator::EQ; break; 6377 case tok::amp: Opc = BinaryOperator::And; break; 6378 case tok::caret: Opc = BinaryOperator::Xor; break; 6379 case tok::pipe: Opc = BinaryOperator::Or; break; 6380 case tok::ampamp: Opc = BinaryOperator::LAnd; break; 6381 case tok::pipepipe: Opc = BinaryOperator::LOr; break; 6382 case tok::equal: Opc = BinaryOperator::Assign; break; 6383 case tok::starequal: Opc = BinaryOperator::MulAssign; break; 6384 case tok::slashequal: Opc = BinaryOperator::DivAssign; break; 6385 case tok::percentequal: Opc = BinaryOperator::RemAssign; break; 6386 case tok::plusequal: Opc = BinaryOperator::AddAssign; break; 6387 case tok::minusequal: Opc = BinaryOperator::SubAssign; break; 6388 case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break; 6389 case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break; 6390 case tok::ampequal: Opc = BinaryOperator::AndAssign; break; 6391 case tok::caretequal: Opc = BinaryOperator::XorAssign; break; 6392 case tok::pipeequal: Opc = BinaryOperator::OrAssign; break; 6393 case tok::comma: Opc = BinaryOperator::Comma; break; 6394 } 6395 return Opc; 6396} 6397 6398static inline UnaryOperator::Opcode ConvertTokenKindToUnaryOpcode( 6399 tok::TokenKind Kind) { 6400 UnaryOperator::Opcode Opc; 6401 switch (Kind) { 6402 default: assert(0 && "Unknown unary op!"); 6403 case tok::plusplus: Opc = UnaryOperator::PreInc; break; 6404 case tok::minusminus: Opc = UnaryOperator::PreDec; break; 6405 case tok::amp: Opc = UnaryOperator::AddrOf; break; 6406 case tok::star: Opc = UnaryOperator::Deref; break; 6407 case tok::plus: Opc = UnaryOperator::Plus; break; 6408 case tok::minus: Opc = UnaryOperator::Minus; break; 6409 case tok::tilde: Opc = UnaryOperator::Not; break; 6410 case tok::exclaim: Opc = UnaryOperator::LNot; break; 6411 case tok::kw___real: Opc = UnaryOperator::Real; break; 6412 case tok::kw___imag: Opc = UnaryOperator::Imag; break; 6413 case tok::kw___extension__: Opc = UnaryOperator::Extension; break; 6414 } 6415 return Opc; 6416} 6417 6418/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6419/// operator @p Opc at location @c TokLoc. This routine only supports 6420/// built-in operations; ActOnBinOp handles overloaded operators. 6421Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6422 unsigned Op, 6423 Expr *lhs, Expr *rhs) { 6424 QualType ResultTy; // Result type of the binary operator. 6425 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)Op; 6426 // The following two variables are used for compound assignment operators 6427 QualType CompLHSTy; // Type of LHS after promotions for computation 6428 QualType CompResultTy; // Type of computation result 6429 6430 switch (Opc) { 6431 case BinaryOperator::Assign: 6432 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6433 break; 6434 case BinaryOperator::PtrMemD: 6435 case BinaryOperator::PtrMemI: 6436 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6437 Opc == BinaryOperator::PtrMemI); 6438 break; 6439 case BinaryOperator::Mul: 6440 case BinaryOperator::Div: 6441 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6442 Opc == BinaryOperator::Div); 6443 break; 6444 case BinaryOperator::Rem: 6445 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6446 break; 6447 case BinaryOperator::Add: 6448 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6449 break; 6450 case BinaryOperator::Sub: 6451 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6452 break; 6453 case BinaryOperator::Shl: 6454 case BinaryOperator::Shr: 6455 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6456 break; 6457 case BinaryOperator::LE: 6458 case BinaryOperator::LT: 6459 case BinaryOperator::GE: 6460 case BinaryOperator::GT: 6461 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6462 break; 6463 case BinaryOperator::EQ: 6464 case BinaryOperator::NE: 6465 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6466 break; 6467 case BinaryOperator::And: 6468 case BinaryOperator::Xor: 6469 case BinaryOperator::Or: 6470 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6471 break; 6472 case BinaryOperator::LAnd: 6473 case BinaryOperator::LOr: 6474 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 6475 break; 6476 case BinaryOperator::MulAssign: 6477 case BinaryOperator::DivAssign: 6478 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6479 Opc == BinaryOperator::DivAssign); 6480 CompLHSTy = CompResultTy; 6481 if (!CompResultTy.isNull()) 6482 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6483 break; 6484 case BinaryOperator::RemAssign: 6485 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6486 CompLHSTy = CompResultTy; 6487 if (!CompResultTy.isNull()) 6488 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6489 break; 6490 case BinaryOperator::AddAssign: 6491 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6492 if (!CompResultTy.isNull()) 6493 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6494 break; 6495 case BinaryOperator::SubAssign: 6496 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6497 if (!CompResultTy.isNull()) 6498 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6499 break; 6500 case BinaryOperator::ShlAssign: 6501 case BinaryOperator::ShrAssign: 6502 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6503 CompLHSTy = CompResultTy; 6504 if (!CompResultTy.isNull()) 6505 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6506 break; 6507 case BinaryOperator::AndAssign: 6508 case BinaryOperator::XorAssign: 6509 case BinaryOperator::OrAssign: 6510 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6511 CompLHSTy = CompResultTy; 6512 if (!CompResultTy.isNull()) 6513 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6514 break; 6515 case BinaryOperator::Comma: 6516 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6517 break; 6518 } 6519 if (ResultTy.isNull()) 6520 return ExprError(); 6521 if (ResultTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6522 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) 6523 Diag(OpLoc, diag::err_assignment_requires_nonfragile_object) 6524 << ResultTy; 6525 } 6526 if (CompResultTy.isNull()) 6527 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6528 else 6529 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6530 CompLHSTy, CompResultTy, 6531 OpLoc)); 6532} 6533 6534/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6535/// ParenRange in parentheses. 6536static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6537 const PartialDiagnostic &PD, 6538 const PartialDiagnostic &FirstNote, 6539 SourceRange FirstParenRange, 6540 const PartialDiagnostic &SecondNote, 6541 SourceRange SecondParenRange) { 6542 Self.Diag(Loc, PD); 6543 6544 if (!FirstNote.getDiagID()) 6545 return; 6546 6547 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 6548 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6549 // We can't display the parentheses, so just return. 6550 return; 6551 } 6552 6553 Self.Diag(Loc, FirstNote) 6554 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 6555 << FixItHint::CreateInsertion(EndLoc, ")"); 6556 6557 if (!SecondNote.getDiagID()) 6558 return; 6559 6560 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6561 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6562 // We can't display the parentheses, so just dig the 6563 // warning/error and return. 6564 Self.Diag(Loc, SecondNote); 6565 return; 6566 } 6567 6568 Self.Diag(Loc, SecondNote) 6569 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6570 << FixItHint::CreateInsertion(EndLoc, ")"); 6571} 6572 6573/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6574/// operators are mixed in a way that suggests that the programmer forgot that 6575/// comparison operators have higher precedence. The most typical example of 6576/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6577static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6578 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6579 typedef BinaryOperator BinOp; 6580 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6581 rhsopc = static_cast<BinOp::Opcode>(-1); 6582 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6583 lhsopc = BO->getOpcode(); 6584 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6585 rhsopc = BO->getOpcode(); 6586 6587 // Subs are not binary operators. 6588 if (lhsopc == -1 && rhsopc == -1) 6589 return; 6590 6591 // Bitwise operations are sometimes used as eager logical ops. 6592 // Don't diagnose this. 6593 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6594 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6595 return; 6596 6597 if (BinOp::isComparisonOp(lhsopc)) 6598 SuggestParentheses(Self, OpLoc, 6599 Self.PDiag(diag::warn_precedence_bitwise_rel) 6600 << SourceRange(lhs->getLocStart(), OpLoc) 6601 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6602 Self.PDiag(diag::note_precedence_bitwise_first) 6603 << BinOp::getOpcodeStr(Opc), 6604 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 6605 Self.PDiag(diag::note_precedence_bitwise_silence) 6606 << BinOp::getOpcodeStr(lhsopc), 6607 lhs->getSourceRange()); 6608 else if (BinOp::isComparisonOp(rhsopc)) 6609 SuggestParentheses(Self, OpLoc, 6610 Self.PDiag(diag::warn_precedence_bitwise_rel) 6611 << SourceRange(OpLoc, rhs->getLocEnd()) 6612 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6613 Self.PDiag(diag::note_precedence_bitwise_first) 6614 << BinOp::getOpcodeStr(Opc), 6615 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 6616 Self.PDiag(diag::note_precedence_bitwise_silence) 6617 << BinOp::getOpcodeStr(rhsopc), 6618 rhs->getSourceRange()); 6619} 6620 6621/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6622/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6623/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6624static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6625 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6626 if (BinaryOperator::isBitwiseOp(Opc)) 6627 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6628} 6629 6630// Binary Operators. 'Tok' is the token for the operator. 6631Action::OwningExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6632 tok::TokenKind Kind, 6633 Expr *lhs, Expr *rhs) { 6634 BinaryOperator::Opcode Opc = ConvertTokenKindToBinaryOpcode(Kind); 6635 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6636 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6637 6638 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6639 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6640 6641 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6642} 6643 6644Action::OwningExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6645 BinaryOperator::Opcode Opc, 6646 Expr *lhs, Expr *rhs) { 6647 if (getLangOptions().CPlusPlus && 6648 (lhs->getType()->isOverloadableType() || 6649 rhs->getType()->isOverloadableType())) { 6650 // Find all of the overloaded operators visible from this 6651 // point. We perform both an operator-name lookup from the local 6652 // scope and an argument-dependent lookup based on the types of 6653 // the arguments. 6654 UnresolvedSet<16> Functions; 6655 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6656 if (S && OverOp != OO_None) 6657 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6658 Functions); 6659 6660 // Build the (potentially-overloaded, potentially-dependent) 6661 // binary operation. 6662 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6663 } 6664 6665 // Build a built-in binary operation. 6666 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6667} 6668 6669Action::OwningExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6670 unsigned OpcIn, 6671 Expr *Input) { 6672 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6673 6674 QualType resultType; 6675 switch (Opc) { 6676 case UnaryOperator::PreInc: 6677 case UnaryOperator::PreDec: 6678 case UnaryOperator::PostInc: 6679 case UnaryOperator::PostDec: 6680 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6681 Opc == UnaryOperator::PreInc || 6682 Opc == UnaryOperator::PostInc, 6683 Opc == UnaryOperator::PreInc || 6684 Opc == UnaryOperator::PreDec); 6685 break; 6686 case UnaryOperator::AddrOf: 6687 resultType = CheckAddressOfOperand(Input, OpLoc); 6688 break; 6689 case UnaryOperator::Deref: 6690 DefaultFunctionArrayLvalueConversion(Input); 6691 resultType = CheckIndirectionOperand(Input, OpLoc); 6692 break; 6693 case UnaryOperator::Plus: 6694 case UnaryOperator::Minus: 6695 UsualUnaryConversions(Input); 6696 resultType = Input->getType(); 6697 if (resultType->isDependentType()) 6698 break; 6699 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 6700 resultType->isVectorType()) 6701 break; 6702 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6703 resultType->isEnumeralType()) 6704 break; 6705 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6706 Opc == UnaryOperator::Plus && 6707 resultType->isPointerType()) 6708 break; 6709 6710 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6711 << resultType << Input->getSourceRange()); 6712 case UnaryOperator::Not: // bitwise complement 6713 UsualUnaryConversions(Input); 6714 resultType = Input->getType(); 6715 if (resultType->isDependentType()) 6716 break; 6717 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6718 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6719 // C99 does not support '~' for complex conjugation. 6720 Diag(OpLoc, diag::ext_integer_complement_complex) 6721 << resultType << Input->getSourceRange(); 6722 else if (!resultType->hasIntegerRepresentation()) 6723 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6724 << resultType << Input->getSourceRange()); 6725 break; 6726 case UnaryOperator::LNot: // logical negation 6727 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6728 DefaultFunctionArrayLvalueConversion(Input); 6729 resultType = Input->getType(); 6730 if (resultType->isDependentType()) 6731 break; 6732 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6733 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6734 << resultType << Input->getSourceRange()); 6735 // LNot always has type int. C99 6.5.3.3p5. 6736 // In C++, it's bool. C++ 5.3.1p8 6737 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6738 break; 6739 case UnaryOperator::Real: 6740 case UnaryOperator::Imag: 6741 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UnaryOperator::Real); 6742 break; 6743 case UnaryOperator::Extension: 6744 resultType = Input->getType(); 6745 break; 6746 } 6747 if (resultType.isNull()) 6748 return ExprError(); 6749 6750 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6751} 6752 6753Action::OwningExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6754 UnaryOperator::Opcode Opc, 6755 Expr *Input) { 6756 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6757 Opc != UnaryOperator::Extension) { 6758 // Find all of the overloaded operators visible from this 6759 // point. We perform both an operator-name lookup from the local 6760 // scope and an argument-dependent lookup based on the types of 6761 // the arguments. 6762 UnresolvedSet<16> Functions; 6763 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6764 if (S && OverOp != OO_None) 6765 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6766 Functions); 6767 6768 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); 6769 } 6770 6771 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6772} 6773 6774// Unary Operators. 'Tok' is the token for the operator. 6775Action::OwningExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6776 tok::TokenKind Op, Expr *Input) { 6777 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); 6778} 6779 6780/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6781Sema::OwningExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6782 SourceLocation LabLoc, 6783 IdentifierInfo *LabelII) { 6784 // Look up the record for this label identifier. 6785 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 6786 6787 // If we haven't seen this label yet, create a forward reference. It 6788 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6789 if (LabelDecl == 0) 6790 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6791 6792 // Create the AST node. The address of a label always has type 'void*'. 6793 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6794 Context.getPointerType(Context.VoidTy))); 6795} 6796 6797Sema::OwningExprResult 6798Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, 6799 SourceLocation RPLoc) { // "({..})" 6800 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6801 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6802 6803 bool isFileScope 6804 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6805 if (isFileScope) 6806 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6807 6808 // FIXME: there are a variety of strange constraints to enforce here, for 6809 // example, it is not possible to goto into a stmt expression apparently. 6810 // More semantic analysis is needed. 6811 6812 // If there are sub stmts in the compound stmt, take the type of the last one 6813 // as the type of the stmtexpr. 6814 QualType Ty = Context.VoidTy; 6815 6816 if (!Compound->body_empty()) { 6817 Stmt *LastStmt = Compound->body_back(); 6818 // If LastStmt is a label, skip down through into the body. 6819 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6820 LastStmt = Label->getSubStmt(); 6821 6822 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6823 Ty = LastExpr->getType(); 6824 } 6825 6826 // FIXME: Check that expression type is complete/non-abstract; statement 6827 // expressions are not lvalues. 6828 6829 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6830} 6831 6832Sema::OwningExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 6833 TypeSourceInfo *TInfo, 6834 OffsetOfComponent *CompPtr, 6835 unsigned NumComponents, 6836 SourceLocation RParenLoc) { 6837 QualType ArgTy = TInfo->getType(); 6838 bool Dependent = ArgTy->isDependentType(); 6839 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 6840 6841 // We must have at least one component that refers to the type, and the first 6842 // one is known to be a field designator. Verify that the ArgTy represents 6843 // a struct/union/class. 6844 if (!Dependent && !ArgTy->isRecordType()) 6845 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 6846 << ArgTy << TypeRange); 6847 6848 // Type must be complete per C99 7.17p3 because a declaring a variable 6849 // with an incomplete type would be ill-formed. 6850 if (!Dependent 6851 && RequireCompleteType(BuiltinLoc, ArgTy, 6852 PDiag(diag::err_offsetof_incomplete_type) 6853 << TypeRange)) 6854 return ExprError(); 6855 6856 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6857 // GCC extension, diagnose them. 6858 // FIXME: This diagnostic isn't actually visible because the location is in 6859 // a system header! 6860 if (NumComponents != 1) 6861 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6862 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6863 6864 bool DidWarnAboutNonPOD = false; 6865 QualType CurrentType = ArgTy; 6866 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 6867 llvm::SmallVector<OffsetOfNode, 4> Comps; 6868 llvm::SmallVector<Expr*, 4> Exprs; 6869 for (unsigned i = 0; i != NumComponents; ++i) { 6870 const OffsetOfComponent &OC = CompPtr[i]; 6871 if (OC.isBrackets) { 6872 // Offset of an array sub-field. TODO: Should we allow vector elements? 6873 if (!CurrentType->isDependentType()) { 6874 const ArrayType *AT = Context.getAsArrayType(CurrentType); 6875 if(!AT) 6876 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6877 << CurrentType); 6878 CurrentType = AT->getElementType(); 6879 } else 6880 CurrentType = Context.DependentTy; 6881 6882 // The expression must be an integral expression. 6883 // FIXME: An integral constant expression? 6884 Expr *Idx = static_cast<Expr*>(OC.U.E); 6885 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 6886 !Idx->getType()->isIntegerType()) 6887 return ExprError(Diag(Idx->getLocStart(), 6888 diag::err_typecheck_subscript_not_integer) 6889 << Idx->getSourceRange()); 6890 6891 // Record this array index. 6892 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 6893 Exprs.push_back(Idx); 6894 continue; 6895 } 6896 6897 // Offset of a field. 6898 if (CurrentType->isDependentType()) { 6899 // We have the offset of a field, but we can't look into the dependent 6900 // type. Just record the identifier of the field. 6901 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 6902 CurrentType = Context.DependentTy; 6903 continue; 6904 } 6905 6906 // We need to have a complete type to look into. 6907 if (RequireCompleteType(OC.LocStart, CurrentType, 6908 diag::err_offsetof_incomplete_type)) 6909 return ExprError(); 6910 6911 // Look for the designated field. 6912 const RecordType *RC = CurrentType->getAs<RecordType>(); 6913 if (!RC) 6914 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6915 << CurrentType); 6916 RecordDecl *RD = RC->getDecl(); 6917 6918 // C++ [lib.support.types]p5: 6919 // The macro offsetof accepts a restricted set of type arguments in this 6920 // International Standard. type shall be a POD structure or a POD union 6921 // (clause 9). 6922 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6923 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6924 DiagRuntimeBehavior(BuiltinLoc, 6925 PDiag(diag::warn_offsetof_non_pod_type) 6926 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6927 << CurrentType)) 6928 DidWarnAboutNonPOD = true; 6929 } 6930 6931 // Look for the field. 6932 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6933 LookupQualifiedName(R, RD); 6934 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6935 if (!MemberDecl) 6936 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6937 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 6938 OC.LocEnd)); 6939 6940 // C99 7.17p3: 6941 // (If the specified member is a bit-field, the behavior is undefined.) 6942 // 6943 // We diagnose this as an error. 6944 if (MemberDecl->getBitWidth()) { 6945 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 6946 << MemberDecl->getDeclName() 6947 << SourceRange(BuiltinLoc, RParenLoc); 6948 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 6949 return ExprError(); 6950 } 6951 6952 RecordDecl *Parent = MemberDecl->getParent(); 6953 bool AnonStructUnion = Parent->isAnonymousStructOrUnion(); 6954 if (AnonStructUnion) { 6955 do { 6956 Parent = cast<RecordDecl>(Parent->getParent()); 6957 } while (Parent->isAnonymousStructOrUnion()); 6958 } 6959 6960 // If the member was found in a base class, introduce OffsetOfNodes for 6961 // the base class indirections. 6962 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 6963 /*DetectVirtual=*/false); 6964 if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { 6965 CXXBasePath &Path = Paths.front(); 6966 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 6967 B != BEnd; ++B) 6968 Comps.push_back(OffsetOfNode(B->Base)); 6969 } 6970 6971 if (AnonStructUnion) { 6972 llvm::SmallVector<FieldDecl*, 4> Path; 6973 BuildAnonymousStructUnionMemberPath(MemberDecl, Path); 6974 unsigned n = Path.size(); 6975 for (int j = n - 1; j > -1; --j) 6976 Comps.push_back(OffsetOfNode(OC.LocStart, Path[j], OC.LocEnd)); 6977 } else { 6978 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 6979 } 6980 CurrentType = MemberDecl->getType().getNonReferenceType(); 6981 } 6982 6983 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 6984 TInfo, Comps.data(), Comps.size(), 6985 Exprs.data(), Exprs.size(), RParenLoc)); 6986} 6987 6988Sema::OwningExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 6989 SourceLocation BuiltinLoc, 6990 SourceLocation TypeLoc, 6991 ParsedType argty, 6992 OffsetOfComponent *CompPtr, 6993 unsigned NumComponents, 6994 SourceLocation RPLoc) { 6995 6996 TypeSourceInfo *ArgTInfo; 6997 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 6998 if (ArgTy.isNull()) 6999 return ExprError(); 7000 7001 if (!ArgTInfo) 7002 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 7003 7004 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 7005 RPLoc); 7006} 7007 7008 7009Sema::OwningExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 7010 ParsedType arg1,ParsedType arg2, 7011 SourceLocation RPLoc) { 7012 TypeSourceInfo *argTInfo1; 7013 QualType argT1 = GetTypeFromParser(arg1, &argTInfo1); 7014 TypeSourceInfo *argTInfo2; 7015 QualType argT2 = GetTypeFromParser(arg2, &argTInfo2); 7016 7017 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 7018 7019 return BuildTypesCompatibleExpr(BuiltinLoc, argTInfo1, argTInfo2, RPLoc); 7020} 7021 7022Sema::OwningExprResult 7023Sema::BuildTypesCompatibleExpr(SourceLocation BuiltinLoc, 7024 TypeSourceInfo *argTInfo1, 7025 TypeSourceInfo *argTInfo2, 7026 SourceLocation RPLoc) { 7027 if (getLangOptions().CPlusPlus) { 7028 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 7029 << SourceRange(BuiltinLoc, RPLoc); 7030 return ExprError(); 7031 } 7032 7033 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 7034 argTInfo1, argTInfo2, RPLoc)); 7035} 7036 7037 7038Sema::OwningExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 7039 Expr *CondExpr, 7040 Expr *LHSExpr, Expr *RHSExpr, 7041 SourceLocation RPLoc) { 7042 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 7043 7044 QualType resType; 7045 bool ValueDependent = false; 7046 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 7047 resType = Context.DependentTy; 7048 ValueDependent = true; 7049 } else { 7050 // The conditional expression is required to be a constant expression. 7051 llvm::APSInt condEval(32); 7052 SourceLocation ExpLoc; 7053 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 7054 return ExprError(Diag(ExpLoc, 7055 diag::err_typecheck_choose_expr_requires_constant) 7056 << CondExpr->getSourceRange()); 7057 7058 // If the condition is > zero, then the AST type is the same as the LSHExpr. 7059 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 7060 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 7061 : RHSExpr->isValueDependent(); 7062 } 7063 7064 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 7065 resType, RPLoc, 7066 resType->isDependentType(), 7067 ValueDependent)); 7068} 7069 7070//===----------------------------------------------------------------------===// 7071// Clang Extensions. 7072//===----------------------------------------------------------------------===// 7073 7074/// ActOnBlockStart - This callback is invoked when a block literal is started. 7075void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 7076 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 7077 PushBlockScope(BlockScope, Block); 7078 CurContext->addDecl(Block); 7079 if (BlockScope) 7080 PushDeclContext(BlockScope, Block); 7081 else 7082 CurContext = Block; 7083} 7084 7085void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 7086 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 7087 BlockScopeInfo *CurBlock = getCurBlock(); 7088 7089 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 7090 CurBlock->TheDecl->setSignatureAsWritten(Sig); 7091 QualType T = Sig->getType(); 7092 7093 bool isVariadic; 7094 QualType RetTy; 7095 if (const FunctionType *Fn = T->getAs<FunctionType>()) { 7096 CurBlock->FunctionType = T; 7097 RetTy = Fn->getResultType(); 7098 isVariadic = 7099 !isa<FunctionProtoType>(Fn) || cast<FunctionProtoType>(Fn)->isVariadic(); 7100 } else { 7101 RetTy = T; 7102 isVariadic = false; 7103 } 7104 7105 CurBlock->TheDecl->setIsVariadic(isVariadic); 7106 7107 // Don't allow returning an array by value. 7108 if (RetTy->isArrayType()) { 7109 Diag(ParamInfo.getSourceRange().getBegin(), diag::err_block_returns_array); 7110 return; 7111 } 7112 7113 // Don't allow returning a objc interface by value. 7114 if (RetTy->isObjCObjectType()) { 7115 Diag(ParamInfo.getSourceRange().getBegin(), 7116 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7117 return; 7118 } 7119 7120 // Context.DependentTy is used as a placeholder for a missing block 7121 // return type. TODO: what should we do with declarators like: 7122 // ^ * { ... } 7123 // If the answer is "apply template argument deduction".... 7124 if (RetTy != Context.DependentTy) 7125 CurBlock->ReturnType = RetTy; 7126 7127 // Push block parameters from the declarator if we had them. 7128 llvm::SmallVector<ParmVarDecl*, 8> Params; 7129 if (isa<FunctionProtoType>(T)) { 7130 FunctionProtoTypeLoc TL = cast<FunctionProtoTypeLoc>(Sig->getTypeLoc()); 7131 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 7132 ParmVarDecl *Param = TL.getArg(I); 7133 if (Param->getIdentifier() == 0 && 7134 !Param->isImplicit() && 7135 !Param->isInvalidDecl() && 7136 !getLangOptions().CPlusPlus) 7137 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 7138 Params.push_back(Param); 7139 } 7140 7141 // Fake up parameter variables if we have a typedef, like 7142 // ^ fntype { ... } 7143 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 7144 for (FunctionProtoType::arg_type_iterator 7145 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 7146 ParmVarDecl *Param = 7147 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 7148 ParamInfo.getSourceRange().getBegin(), 7149 *I); 7150 Params.push_back(Param); 7151 } 7152 } 7153 7154 // Set the parameters on the block decl. 7155 if (!Params.empty()) 7156 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 7157 7158 // Finally we can process decl attributes. 7159 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 7160 7161 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 7162 Diag(ParamInfo.getAttributes()->getLoc(), 7163 diag::warn_attribute_sentinel_not_variadic) << 1; 7164 // FIXME: remove the attribute. 7165 } 7166 7167 // Put the parameter variables in scope. We can bail out immediately 7168 // if we don't have any. 7169 if (Params.empty()) 7170 return; 7171 7172 bool ShouldCheckShadow = 7173 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 7174 7175 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 7176 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 7177 (*AI)->setOwningFunction(CurBlock->TheDecl); 7178 7179 // If this has an identifier, add it to the scope stack. 7180 if ((*AI)->getIdentifier()) { 7181 if (ShouldCheckShadow) 7182 CheckShadow(CurBlock->TheScope, *AI); 7183 7184 PushOnScopeChains(*AI, CurBlock->TheScope); 7185 } 7186 } 7187} 7188 7189/// ActOnBlockError - If there is an error parsing a block, this callback 7190/// is invoked to pop the information about the block from the action impl. 7191void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7192 // Pop off CurBlock, handle nested blocks. 7193 PopDeclContext(); 7194 PopFunctionOrBlockScope(); 7195 // FIXME: Delete the ParmVarDecl objects as well??? 7196} 7197 7198/// ActOnBlockStmtExpr - This is called when the body of a block statement 7199/// literal was successfully completed. ^(int x){...} 7200Sema::OwningExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7201 Stmt *Body, Scope *CurScope) { 7202 // If blocks are disabled, emit an error. 7203 if (!LangOpts.Blocks) 7204 Diag(CaretLoc, diag::err_blocks_disable); 7205 7206 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7207 7208 PopDeclContext(); 7209 7210 QualType RetTy = Context.VoidTy; 7211 if (!BSI->ReturnType.isNull()) 7212 RetTy = BSI->ReturnType; 7213 7214 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7215 QualType BlockTy; 7216 7217 // If the user wrote a function type in some form, try to use that. 7218 if (!BSI->FunctionType.isNull()) { 7219 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 7220 7221 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 7222 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 7223 7224 // Turn protoless block types into nullary block types. 7225 if (isa<FunctionNoProtoType>(FTy)) { 7226 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7227 false, false, 0, 0, Ext); 7228 7229 // Otherwise, if we don't need to change anything about the function type, 7230 // preserve its sugar structure. 7231 } else if (FTy->getResultType() == RetTy && 7232 (!NoReturn || FTy->getNoReturnAttr())) { 7233 BlockTy = BSI->FunctionType; 7234 7235 // Otherwise, make the minimal modifications to the function type. 7236 } else { 7237 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 7238 BlockTy = Context.getFunctionType(RetTy, 7239 FPT->arg_type_begin(), 7240 FPT->getNumArgs(), 7241 FPT->isVariadic(), 7242 /*quals*/ 0, 7243 FPT->hasExceptionSpec(), 7244 FPT->hasAnyExceptionSpec(), 7245 FPT->getNumExceptions(), 7246 FPT->exception_begin(), 7247 Ext); 7248 } 7249 7250 // If we don't have a function type, just build one from nothing. 7251 } else { 7252 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7253 false, false, 0, 0, 7254 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7255 } 7256 7257 // FIXME: Check that return/parameter types are complete/non-abstract 7258 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 7259 BSI->TheDecl->param_end()); 7260 BlockTy = Context.getBlockPointerType(BlockTy); 7261 7262 // If needed, diagnose invalid gotos and switches in the block. 7263 if (FunctionNeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7264 DiagnoseInvalidJumps(cast<CompoundStmt>(Body)); 7265 7266 BSI->TheDecl->setBody(cast<CompoundStmt>(Body)); 7267 7268 bool Good = true; 7269 // Check goto/label use. 7270 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7271 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7272 LabelStmt *L = I->second; 7273 7274 // Verify that we have no forward references left. If so, there was a goto 7275 // or address of a label taken, but no definition of it. 7276 if (L->getSubStmt() != 0) 7277 continue; 7278 7279 // Emit error. 7280 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7281 Good = false; 7282 } 7283 if (!Good) { 7284 PopFunctionOrBlockScope(); 7285 return ExprError(); 7286 } 7287 7288 // Issue any analysis-based warnings. 7289 const sema::AnalysisBasedWarnings::Policy &WP = 7290 AnalysisWarnings.getDefaultPolicy(); 7291 AnalysisWarnings.IssueWarnings(WP, BSI->TheDecl, BlockTy); 7292 7293 Expr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7294 BSI->hasBlockDeclRefExprs); 7295 PopFunctionOrBlockScope(); 7296 return Owned(Result); 7297} 7298 7299Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7300 Expr *expr, ParsedType type, 7301 SourceLocation RPLoc) { 7302 TypeSourceInfo *TInfo; 7303 QualType T = GetTypeFromParser(type, &TInfo); 7304 return BuildVAArgExpr(BuiltinLoc, expr, TInfo, RPLoc); 7305} 7306 7307Sema::OwningExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, 7308 Expr *E, TypeSourceInfo *TInfo, 7309 SourceLocation RPLoc) { 7310 Expr *OrigExpr = E; 7311 7312 InitBuiltinVaListType(); 7313 7314 // Get the va_list type 7315 QualType VaListType = Context.getBuiltinVaListType(); 7316 if (VaListType->isArrayType()) { 7317 // Deal with implicit array decay; for example, on x86-64, 7318 // va_list is an array, but it's supposed to decay to 7319 // a pointer for va_arg. 7320 VaListType = Context.getArrayDecayedType(VaListType); 7321 // Make sure the input expression also decays appropriately. 7322 UsualUnaryConversions(E); 7323 } else { 7324 // Otherwise, the va_list argument must be an l-value because 7325 // it is modified by va_arg. 7326 if (!E->isTypeDependent() && 7327 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7328 return ExprError(); 7329 } 7330 7331 if (!E->isTypeDependent() && 7332 !Context.hasSameType(VaListType, E->getType())) { 7333 return ExprError(Diag(E->getLocStart(), 7334 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7335 << OrigExpr->getType() << E->getSourceRange()); 7336 } 7337 7338 // FIXME: Check that type is complete/non-abstract 7339 // FIXME: Warn if a non-POD type is passed in. 7340 7341 QualType T = TInfo->getType().getNonLValueExprType(Context); 7342 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T)); 7343} 7344 7345Sema::OwningExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7346 // The type of __null will be int or long, depending on the size of 7347 // pointers on the target. 7348 QualType Ty; 7349 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7350 Ty = Context.IntTy; 7351 else 7352 Ty = Context.LongTy; 7353 7354 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7355} 7356 7357static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7358 Expr *SrcExpr, FixItHint &Hint) { 7359 if (!SemaRef.getLangOptions().ObjC1) 7360 return; 7361 7362 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7363 if (!PT) 7364 return; 7365 7366 // Check if the destination is of type 'id'. 7367 if (!PT->isObjCIdType()) { 7368 // Check if the destination is the 'NSString' interface. 7369 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7370 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7371 return; 7372 } 7373 7374 // Strip off any parens and casts. 7375 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7376 if (!SL || SL->isWide()) 7377 return; 7378 7379 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7380} 7381 7382bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7383 SourceLocation Loc, 7384 QualType DstType, QualType SrcType, 7385 Expr *SrcExpr, AssignmentAction Action, 7386 bool *Complained) { 7387 if (Complained) 7388 *Complained = false; 7389 7390 // Decode the result (notice that AST's are still created for extensions). 7391 bool isInvalid = false; 7392 unsigned DiagKind; 7393 FixItHint Hint; 7394 7395 switch (ConvTy) { 7396 default: assert(0 && "Unknown conversion type"); 7397 case Compatible: return false; 7398 case PointerToInt: 7399 DiagKind = diag::ext_typecheck_convert_pointer_int; 7400 break; 7401 case IntToPointer: 7402 DiagKind = diag::ext_typecheck_convert_int_pointer; 7403 break; 7404 case IncompatiblePointer: 7405 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7406 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7407 break; 7408 case IncompatiblePointerSign: 7409 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7410 break; 7411 case FunctionVoidPointer: 7412 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7413 break; 7414 case CompatiblePointerDiscardsQualifiers: 7415 // If the qualifiers lost were because we were applying the 7416 // (deprecated) C++ conversion from a string literal to a char* 7417 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7418 // Ideally, this check would be performed in 7419 // CheckPointerTypesForAssignment. However, that would require a 7420 // bit of refactoring (so that the second argument is an 7421 // expression, rather than a type), which should be done as part 7422 // of a larger effort to fix CheckPointerTypesForAssignment for 7423 // C++ semantics. 7424 if (getLangOptions().CPlusPlus && 7425 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7426 return false; 7427 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7428 break; 7429 case IncompatibleNestedPointerQualifiers: 7430 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7431 break; 7432 case IntToBlockPointer: 7433 DiagKind = diag::err_int_to_block_pointer; 7434 break; 7435 case IncompatibleBlockPointer: 7436 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7437 break; 7438 case IncompatibleObjCQualifiedId: 7439 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7440 // it can give a more specific diagnostic. 7441 DiagKind = diag::warn_incompatible_qualified_id; 7442 break; 7443 case IncompatibleVectors: 7444 DiagKind = diag::warn_incompatible_vectors; 7445 break; 7446 case Incompatible: 7447 DiagKind = diag::err_typecheck_convert_incompatible; 7448 isInvalid = true; 7449 break; 7450 } 7451 7452 QualType FirstType, SecondType; 7453 switch (Action) { 7454 case AA_Assigning: 7455 case AA_Initializing: 7456 // The destination type comes first. 7457 FirstType = DstType; 7458 SecondType = SrcType; 7459 break; 7460 7461 case AA_Returning: 7462 case AA_Passing: 7463 case AA_Converting: 7464 case AA_Sending: 7465 case AA_Casting: 7466 // The source type comes first. 7467 FirstType = SrcType; 7468 SecondType = DstType; 7469 break; 7470 } 7471 7472 Diag(Loc, DiagKind) << FirstType << SecondType << Action 7473 << SrcExpr->getSourceRange() << Hint; 7474 if (Complained) 7475 *Complained = true; 7476 return isInvalid; 7477} 7478 7479bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7480 llvm::APSInt ICEResult; 7481 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7482 if (Result) 7483 *Result = ICEResult; 7484 return false; 7485 } 7486 7487 Expr::EvalResult EvalResult; 7488 7489 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7490 EvalResult.HasSideEffects) { 7491 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7492 7493 if (EvalResult.Diag) { 7494 // We only show the note if it's not the usual "invalid subexpression" 7495 // or if it's actually in a subexpression. 7496 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7497 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7498 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7499 } 7500 7501 return true; 7502 } 7503 7504 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7505 E->getSourceRange(); 7506 7507 if (EvalResult.Diag && 7508 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7509 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7510 7511 if (Result) 7512 *Result = EvalResult.Val.getInt(); 7513 return false; 7514} 7515 7516void 7517Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7518 ExprEvalContexts.push_back( 7519 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7520} 7521 7522void 7523Sema::PopExpressionEvaluationContext() { 7524 // Pop the current expression evaluation context off the stack. 7525 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7526 ExprEvalContexts.pop_back(); 7527 7528 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7529 if (Rec.PotentiallyReferenced) { 7530 // Mark any remaining declarations in the current position of the stack 7531 // as "referenced". If they were not meant to be referenced, semantic 7532 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7533 for (PotentiallyReferencedDecls::iterator 7534 I = Rec.PotentiallyReferenced->begin(), 7535 IEnd = Rec.PotentiallyReferenced->end(); 7536 I != IEnd; ++I) 7537 MarkDeclarationReferenced(I->first, I->second); 7538 } 7539 7540 if (Rec.PotentiallyDiagnosed) { 7541 // Emit any pending diagnostics. 7542 for (PotentiallyEmittedDiagnostics::iterator 7543 I = Rec.PotentiallyDiagnosed->begin(), 7544 IEnd = Rec.PotentiallyDiagnosed->end(); 7545 I != IEnd; ++I) 7546 Diag(I->first, I->second); 7547 } 7548 } 7549 7550 // When are coming out of an unevaluated context, clear out any 7551 // temporaries that we may have created as part of the evaluation of 7552 // the expression in that context: they aren't relevant because they 7553 // will never be constructed. 7554 if (Rec.Context == Unevaluated && 7555 ExprTemporaries.size() > Rec.NumTemporaries) 7556 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7557 ExprTemporaries.end()); 7558 7559 // Destroy the popped expression evaluation record. 7560 Rec.Destroy(); 7561} 7562 7563/// \brief Note that the given declaration was referenced in the source code. 7564/// 7565/// This routine should be invoke whenever a given declaration is referenced 7566/// in the source code, and where that reference occurred. If this declaration 7567/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7568/// C99 6.9p3), then the declaration will be marked as used. 7569/// 7570/// \param Loc the location where the declaration was referenced. 7571/// 7572/// \param D the declaration that has been referenced by the source code. 7573void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7574 assert(D && "No declaration?"); 7575 7576 if (D->isUsed(false)) 7577 return; 7578 7579 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7580 // template or not. The reason for this is that unevaluated expressions 7581 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7582 // -Wunused-parameters) 7583 if (isa<ParmVarDecl>(D) || 7584 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7585 D->setUsed(true); 7586 return; 7587 } 7588 7589 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7590 return; 7591 7592 // Do not mark anything as "used" within a dependent context; wait for 7593 // an instantiation. 7594 if (CurContext->isDependentContext()) 7595 return; 7596 7597 switch (ExprEvalContexts.back().Context) { 7598 case Unevaluated: 7599 // We are in an expression that is not potentially evaluated; do nothing. 7600 return; 7601 7602 case PotentiallyEvaluated: 7603 // We are in a potentially-evaluated expression, so this declaration is 7604 // "used"; handle this below. 7605 break; 7606 7607 case PotentiallyPotentiallyEvaluated: 7608 // We are in an expression that may be potentially evaluated; queue this 7609 // declaration reference until we know whether the expression is 7610 // potentially evaluated. 7611 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7612 return; 7613 } 7614 7615 // Note that this declaration has been used. 7616 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7617 unsigned TypeQuals; 7618 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7619 if (Constructor->getParent()->hasTrivialConstructor()) 7620 return; 7621 if (!Constructor->isUsed(false)) 7622 DefineImplicitDefaultConstructor(Loc, Constructor); 7623 } else if (Constructor->isImplicit() && 7624 Constructor->isCopyConstructor(TypeQuals)) { 7625 if (!Constructor->isUsed(false)) 7626 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7627 } 7628 7629 MarkVTableUsed(Loc, Constructor->getParent()); 7630 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7631 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 7632 DefineImplicitDestructor(Loc, Destructor); 7633 if (Destructor->isVirtual()) 7634 MarkVTableUsed(Loc, Destructor->getParent()); 7635 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7636 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7637 MethodDecl->getOverloadedOperator() == OO_Equal) { 7638 if (!MethodDecl->isUsed(false)) 7639 DefineImplicitCopyAssignment(Loc, MethodDecl); 7640 } else if (MethodDecl->isVirtual()) 7641 MarkVTableUsed(Loc, MethodDecl->getParent()); 7642 } 7643 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7644 // Implicit instantiation of function templates and member functions of 7645 // class templates. 7646 if (Function->isImplicitlyInstantiable()) { 7647 bool AlreadyInstantiated = false; 7648 if (FunctionTemplateSpecializationInfo *SpecInfo 7649 = Function->getTemplateSpecializationInfo()) { 7650 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7651 SpecInfo->setPointOfInstantiation(Loc); 7652 else if (SpecInfo->getTemplateSpecializationKind() 7653 == TSK_ImplicitInstantiation) 7654 AlreadyInstantiated = true; 7655 } else if (MemberSpecializationInfo *MSInfo 7656 = Function->getMemberSpecializationInfo()) { 7657 if (MSInfo->getPointOfInstantiation().isInvalid()) 7658 MSInfo->setPointOfInstantiation(Loc); 7659 else if (MSInfo->getTemplateSpecializationKind() 7660 == TSK_ImplicitInstantiation) 7661 AlreadyInstantiated = true; 7662 } 7663 7664 if (!AlreadyInstantiated) { 7665 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7666 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7667 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7668 Loc)); 7669 else 7670 PendingImplicitInstantiations.push_back(std::make_pair(Function, 7671 Loc)); 7672 } 7673 } 7674 7675 // FIXME: keep track of references to static functions 7676 Function->setUsed(true); 7677 7678 return; 7679 } 7680 7681 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7682 // Implicit instantiation of static data members of class templates. 7683 if (Var->isStaticDataMember() && 7684 Var->getInstantiatedFromStaticDataMember()) { 7685 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7686 assert(MSInfo && "Missing member specialization information?"); 7687 if (MSInfo->getPointOfInstantiation().isInvalid() && 7688 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7689 MSInfo->setPointOfInstantiation(Loc); 7690 PendingImplicitInstantiations.push_back(std::make_pair(Var, Loc)); 7691 } 7692 } 7693 7694 // FIXME: keep track of references to static data? 7695 7696 D->setUsed(true); 7697 return; 7698 } 7699} 7700 7701namespace { 7702 // Mark all of the declarations referenced 7703 // FIXME: Not fully implemented yet! We need to have a better understanding 7704 // of when we're entering 7705 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 7706 Sema &S; 7707 SourceLocation Loc; 7708 7709 public: 7710 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 7711 7712 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 7713 7714 bool TraverseTemplateArgument(const TemplateArgument &Arg); 7715 bool TraverseRecordType(RecordType *T); 7716 }; 7717} 7718 7719bool MarkReferencedDecls::TraverseTemplateArgument( 7720 const TemplateArgument &Arg) { 7721 if (Arg.getKind() == TemplateArgument::Declaration) { 7722 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 7723 } 7724 7725 return Inherited::TraverseTemplateArgument(Arg); 7726} 7727 7728bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 7729 if (ClassTemplateSpecializationDecl *Spec 7730 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 7731 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 7732 return TraverseTemplateArguments(Args.getFlatArgumentList(), 7733 Args.flat_size()); 7734 } 7735 7736 return true; 7737} 7738 7739void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 7740 MarkReferencedDecls Marker(*this, Loc); 7741 Marker.TraverseType(Context.getCanonicalType(T)); 7742} 7743 7744/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7745/// of the program being compiled. 7746/// 7747/// This routine emits the given diagnostic when the code currently being 7748/// type-checked is "potentially evaluated", meaning that there is a 7749/// possibility that the code will actually be executable. Code in sizeof() 7750/// expressions, code used only during overload resolution, etc., are not 7751/// potentially evaluated. This routine will suppress such diagnostics or, 7752/// in the absolutely nutty case of potentially potentially evaluated 7753/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7754/// later. 7755/// 7756/// This routine should be used for all diagnostics that describe the run-time 7757/// behavior of a program, such as passing a non-POD value through an ellipsis. 7758/// Failure to do so will likely result in spurious diagnostics or failures 7759/// during overload resolution or within sizeof/alignof/typeof/typeid. 7760bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7761 const PartialDiagnostic &PD) { 7762 switch (ExprEvalContexts.back().Context ) { 7763 case Unevaluated: 7764 // The argument will never be evaluated, so don't complain. 7765 break; 7766 7767 case PotentiallyEvaluated: 7768 Diag(Loc, PD); 7769 return true; 7770 7771 case PotentiallyPotentiallyEvaluated: 7772 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7773 break; 7774 } 7775 7776 return false; 7777} 7778 7779bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7780 CallExpr *CE, FunctionDecl *FD) { 7781 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7782 return false; 7783 7784 PartialDiagnostic Note = 7785 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7786 << FD->getDeclName() : PDiag(); 7787 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7788 7789 if (RequireCompleteType(Loc, ReturnType, 7790 FD ? 7791 PDiag(diag::err_call_function_incomplete_return) 7792 << CE->getSourceRange() << FD->getDeclName() : 7793 PDiag(diag::err_call_incomplete_return) 7794 << CE->getSourceRange(), 7795 std::make_pair(NoteLoc, Note))) 7796 return true; 7797 7798 return false; 7799} 7800 7801// Diagnose the common s/=/==/ typo. Note that adding parentheses 7802// will prevent this condition from triggering, which is what we want. 7803void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7804 SourceLocation Loc; 7805 7806 unsigned diagnostic = diag::warn_condition_is_assignment; 7807 7808 if (isa<BinaryOperator>(E)) { 7809 BinaryOperator *Op = cast<BinaryOperator>(E); 7810 if (Op->getOpcode() != BinaryOperator::Assign) 7811 return; 7812 7813 // Greylist some idioms by putting them into a warning subcategory. 7814 if (ObjCMessageExpr *ME 7815 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7816 Selector Sel = ME->getSelector(); 7817 7818 // self = [<foo> init...] 7819 if (isSelfExpr(Op->getLHS()) 7820 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7821 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7822 7823 // <foo> = [<bar> nextObject] 7824 else if (Sel.isUnarySelector() && 7825 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7826 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7827 } 7828 7829 Loc = Op->getOperatorLoc(); 7830 } else if (isa<CXXOperatorCallExpr>(E)) { 7831 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7832 if (Op->getOperator() != OO_Equal) 7833 return; 7834 7835 Loc = Op->getOperatorLoc(); 7836 } else { 7837 // Not an assignment. 7838 return; 7839 } 7840 7841 SourceLocation Open = E->getSourceRange().getBegin(); 7842 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7843 7844 Diag(Loc, diagnostic) << E->getSourceRange(); 7845 Diag(Loc, diag::note_condition_assign_to_comparison) 7846 << FixItHint::CreateReplacement(Loc, "=="); 7847 Diag(Loc, diag::note_condition_assign_silence) 7848 << FixItHint::CreateInsertion(Open, "(") 7849 << FixItHint::CreateInsertion(Close, ")"); 7850} 7851 7852bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7853 DiagnoseAssignmentAsCondition(E); 7854 7855 if (!E->isTypeDependent()) { 7856 DefaultFunctionArrayLvalueConversion(E); 7857 7858 QualType T = E->getType(); 7859 7860 if (getLangOptions().CPlusPlus) { 7861 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7862 return true; 7863 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7864 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7865 << T << E->getSourceRange(); 7866 return true; 7867 } 7868 } 7869 7870 return false; 7871} 7872 7873Sema::OwningExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 7874 Expr *Sub) { 7875 if (!Sub) 7876 return ExprError(); 7877 7878 if (CheckBooleanCondition(Sub, Loc)) 7879 return ExprError(); 7880 7881 return Owned(Sub); 7882} 7883