SemaExpr.cpp revision fb2200e50a2a0ad9ebe37487a7259579b059cc70
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/SemaInternal.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/EvaluatedExprVisitor.h" 23#include "clang/AST/Expr.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/ExprObjC.h" 26#include "clang/AST/RecursiveASTVisitor.h" 27#include "clang/AST/TypeLoc.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "clang/Basic/SourceManager.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Lex/LiteralSupport.h" 32#include "clang/Lex/Preprocessor.h" 33#include "clang/Sema/DeclSpec.h" 34#include "clang/Sema/Designator.h" 35#include "clang/Sema/Scope.h" 36#include "clang/Sema/ScopeInfo.h" 37#include "clang/Sema/ParsedTemplate.h" 38#include "clang/Sema/Template.h" 39using namespace clang; 40using namespace sema; 41 42 43/// \brief Determine whether the use of this declaration is valid, and 44/// emit any corresponding diagnostics. 45/// 46/// This routine diagnoses various problems with referencing 47/// declarations that can occur when using a declaration. For example, 48/// it might warn if a deprecated or unavailable declaration is being 49/// used, or produce an error (and return true) if a C++0x deleted 50/// function is being used. 51/// 52/// If IgnoreDeprecated is set to true, this should not want about deprecated 53/// decls. 54/// 55/// \returns true if there was an error (this declaration cannot be 56/// referenced), false otherwise. 57/// 58bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) { 59 // See if the decl is deprecated. 60 if (D->getAttr<DeprecatedAttr>()) { 61 EmitDeprecationWarning(D, Loc); 62 } 63 64 // See if the decl is unavailable 65 if (D->getAttr<UnavailableAttr>()) { 66 Diag(Loc, diag::err_unavailable) << D->getDeclName(); 67 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 68 } 69 70 // See if this is a deleted function. 71 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 72 if (FD->isDeleted()) { 73 Diag(Loc, diag::err_deleted_function_use); 74 Diag(D->getLocation(), diag::note_unavailable_here) << true; 75 return true; 76 } 77 } 78 79 return false; 80} 81 82/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 83/// (and other functions in future), which have been declared with sentinel 84/// attribute. It warns if call does not have the sentinel argument. 85/// 86void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 87 Expr **Args, unsigned NumArgs) { 88 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 89 if (!attr) 90 return; 91 92 // FIXME: In C++0x, if any of the arguments are parameter pack 93 // expansions, we can't check for the sentinel now. 94 int sentinelPos = attr->getSentinel(); 95 int nullPos = attr->getNullPos(); 96 97 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 98 // base class. Then we won't be needing two versions of the same code. 99 unsigned int i = 0; 100 bool warnNotEnoughArgs = false; 101 int isMethod = 0; 102 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 103 // skip over named parameters. 104 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 105 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 106 if (nullPos) 107 --nullPos; 108 else 109 ++i; 110 } 111 warnNotEnoughArgs = (P != E || i >= NumArgs); 112 isMethod = 1; 113 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 114 // skip over named parameters. 115 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 116 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 117 if (nullPos) 118 --nullPos; 119 else 120 ++i; 121 } 122 warnNotEnoughArgs = (P != E || i >= NumArgs); 123 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 124 // block or function pointer call. 125 QualType Ty = V->getType(); 126 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 127 const FunctionType *FT = Ty->isFunctionPointerType() 128 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 129 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 130 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 131 unsigned NumArgsInProto = Proto->getNumArgs(); 132 unsigned k; 133 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 134 if (nullPos) 135 --nullPos; 136 else 137 ++i; 138 } 139 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 140 } 141 if (Ty->isBlockPointerType()) 142 isMethod = 2; 143 } else 144 return; 145 } else 146 return; 147 148 if (warnNotEnoughArgs) { 149 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 150 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 151 return; 152 } 153 int sentinel = i; 154 while (sentinelPos > 0 && i < NumArgs-1) { 155 --sentinelPos; 156 ++i; 157 } 158 if (sentinelPos > 0) { 159 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 160 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 161 return; 162 } 163 while (i < NumArgs-1) { 164 ++i; 165 ++sentinel; 166 } 167 Expr *sentinelExpr = Args[sentinel]; 168 if (!sentinelExpr) return; 169 if (sentinelExpr->isTypeDependent()) return; 170 if (sentinelExpr->isValueDependent()) return; 171 if (sentinelExpr->getType()->isAnyPointerType() && 172 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 173 Expr::NPC_ValueDependentIsNull)) 174 return; 175 176 // Unfortunately, __null has type 'int'. 177 if (isa<GNUNullExpr>(sentinelExpr)) return; 178 179 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 180 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 181} 182 183SourceRange Sema::getExprRange(ExprTy *E) const { 184 Expr *Ex = (Expr *)E; 185 return Ex? Ex->getSourceRange() : SourceRange(); 186} 187 188//===----------------------------------------------------------------------===// 189// Standard Promotions and Conversions 190//===----------------------------------------------------------------------===// 191 192/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 193void Sema::DefaultFunctionArrayConversion(Expr *&E) { 194 QualType Ty = E->getType(); 195 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 196 197 if (Ty->isFunctionType()) 198 ImpCastExprToType(E, Context.getPointerType(Ty), 199 CK_FunctionToPointerDecay); 200 else if (Ty->isArrayType()) { 201 // In C90 mode, arrays only promote to pointers if the array expression is 202 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 203 // type 'array of type' is converted to an expression that has type 'pointer 204 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 205 // that has type 'array of type' ...". The relevant change is "an lvalue" 206 // (C90) to "an expression" (C99). 207 // 208 // C++ 4.2p1: 209 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 210 // T" can be converted to an rvalue of type "pointer to T". 211 // 212 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 213 E->isLvalue(Context) == Expr::LV_Valid) 214 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 215 CK_ArrayToPointerDecay); 216 } 217} 218 219void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 220 DefaultFunctionArrayConversion(E); 221 222 QualType Ty = E->getType(); 223 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 224 if (!Ty->isDependentType() && Ty.hasQualifiers() && 225 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 226 E->isLvalue(Context) == Expr::LV_Valid) { 227 // C++ [conv.lval]p1: 228 // [...] If T is a non-class type, the type of the rvalue is the 229 // cv-unqualified version of T. Otherwise, the type of the 230 // rvalue is T 231 // 232 // C99 6.3.2.1p2: 233 // If the lvalue has qualified type, the value has the unqualified 234 // version of the type of the lvalue; otherwise, the value has the 235 // type of the lvalue. 236 ImpCastExprToType(E, Ty.getUnqualifiedType(), CK_NoOp); 237 } 238} 239 240 241/// UsualUnaryConversions - Performs various conversions that are common to most 242/// operators (C99 6.3). The conversions of array and function types are 243/// sometimes surpressed. For example, the array->pointer conversion doesn't 244/// apply if the array is an argument to the sizeof or address (&) operators. 245/// In these instances, this routine should *not* be called. 246Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 247 QualType Ty = Expr->getType(); 248 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 249 250 // C99 6.3.1.1p2: 251 // 252 // The following may be used in an expression wherever an int or 253 // unsigned int may be used: 254 // - an object or expression with an integer type whose integer 255 // conversion rank is less than or equal to the rank of int 256 // and unsigned int. 257 // - A bit-field of type _Bool, int, signed int, or unsigned int. 258 // 259 // If an int can represent all values of the original type, the 260 // value is converted to an int; otherwise, it is converted to an 261 // unsigned int. These are called the integer promotions. All 262 // other types are unchanged by the integer promotions. 263 QualType PTy = Context.isPromotableBitField(Expr); 264 if (!PTy.isNull()) { 265 ImpCastExprToType(Expr, PTy, CK_IntegralCast); 266 return Expr; 267 } 268 if (Ty->isPromotableIntegerType()) { 269 QualType PT = Context.getPromotedIntegerType(Ty); 270 ImpCastExprToType(Expr, PT, CK_IntegralCast); 271 return Expr; 272 } 273 274 DefaultFunctionArrayLvalueConversion(Expr); 275 return Expr; 276} 277 278/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 279/// do not have a prototype. Arguments that have type float are promoted to 280/// double. All other argument types are converted by UsualUnaryConversions(). 281void Sema::DefaultArgumentPromotion(Expr *&Expr) { 282 QualType Ty = Expr->getType(); 283 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 284 285 // If this is a 'float' (CVR qualified or typedef) promote to double. 286 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 287 return ImpCastExprToType(Expr, Context.DoubleTy, 288 CK_FloatingCast); 289 290 UsualUnaryConversions(Expr); 291} 292 293/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 294/// will warn if the resulting type is not a POD type, and rejects ObjC 295/// interfaces passed by value. This returns true if the argument type is 296/// completely illegal. 297bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 298 FunctionDecl *FDecl) { 299 DefaultArgumentPromotion(Expr); 300 301 // __builtin_va_start takes the second argument as a "varargs" argument, but 302 // it doesn't actually do anything with it. It doesn't need to be non-pod 303 // etc. 304 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 305 return false; 306 307 if (Expr->getType()->isObjCObjectType() && 308 DiagRuntimeBehavior(Expr->getLocStart(), 309 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 310 << Expr->getType() << CT)) 311 return true; 312 313 if (!Expr->getType()->isPODType() && 314 DiagRuntimeBehavior(Expr->getLocStart(), 315 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 316 << Expr->getType() << CT)) 317 return true; 318 319 return false; 320} 321 322 323/// UsualArithmeticConversions - Performs various conversions that are common to 324/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 325/// routine returns the first non-arithmetic type found. The client is 326/// responsible for emitting appropriate error diagnostics. 327/// FIXME: verify the conversion rules for "complex int" are consistent with 328/// GCC. 329QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 330 bool isCompAssign) { 331 if (!isCompAssign) 332 UsualUnaryConversions(lhsExpr); 333 334 UsualUnaryConversions(rhsExpr); 335 336 // For conversion purposes, we ignore any qualifiers. 337 // For example, "const float" and "float" are equivalent. 338 QualType lhs = 339 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 340 QualType rhs = 341 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 342 343 // If both types are identical, no conversion is needed. 344 if (lhs == rhs) 345 return lhs; 346 347 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 348 // The caller can deal with this (e.g. pointer + int). 349 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 350 return lhs; 351 352 // Perform bitfield promotions. 353 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 354 if (!LHSBitfieldPromoteTy.isNull()) 355 lhs = LHSBitfieldPromoteTy; 356 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 357 if (!RHSBitfieldPromoteTy.isNull()) 358 rhs = RHSBitfieldPromoteTy; 359 360 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 361 if (!isCompAssign) 362 ImpCastExprToType(lhsExpr, destType, CK_Unknown); 363 ImpCastExprToType(rhsExpr, destType, CK_Unknown); 364 return destType; 365} 366 367//===----------------------------------------------------------------------===// 368// Semantic Analysis for various Expression Types 369//===----------------------------------------------------------------------===// 370 371 372/// ActOnStringLiteral - The specified tokens were lexed as pasted string 373/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 374/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 375/// multiple tokens. However, the common case is that StringToks points to one 376/// string. 377/// 378ExprResult 379Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 380 assert(NumStringToks && "Must have at least one string!"); 381 382 StringLiteralParser Literal(StringToks, NumStringToks, PP); 383 if (Literal.hadError) 384 return ExprError(); 385 386 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 387 for (unsigned i = 0; i != NumStringToks; ++i) 388 StringTokLocs.push_back(StringToks[i].getLocation()); 389 390 QualType StrTy = Context.CharTy; 391 if (Literal.AnyWide) StrTy = Context.getWCharType(); 392 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 393 394 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 395 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 396 StrTy.addConst(); 397 398 // Get an array type for the string, according to C99 6.4.5. This includes 399 // the nul terminator character as well as the string length for pascal 400 // strings. 401 StrTy = Context.getConstantArrayType(StrTy, 402 llvm::APInt(32, Literal.GetNumStringChars()+1), 403 ArrayType::Normal, 0); 404 405 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 406 return Owned(StringLiteral::Create(Context, Literal.GetString(), 407 Literal.GetStringLength(), 408 Literal.AnyWide, StrTy, 409 &StringTokLocs[0], 410 StringTokLocs.size())); 411} 412 413/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 414/// CurBlock to VD should cause it to be snapshotted (as we do for auto 415/// variables defined outside the block) or false if this is not needed (e.g. 416/// for values inside the block or for globals). 417/// 418/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 419/// up-to-date. 420/// 421static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 422 ValueDecl *VD) { 423 // If the value is defined inside the block, we couldn't snapshot it even if 424 // we wanted to. 425 if (CurBlock->TheDecl == VD->getDeclContext()) 426 return false; 427 428 // If this is an enum constant or function, it is constant, don't snapshot. 429 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 430 return false; 431 432 // If this is a reference to an extern, static, or global variable, no need to 433 // snapshot it. 434 // FIXME: What about 'const' variables in C++? 435 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 436 if (!Var->hasLocalStorage()) 437 return false; 438 439 // Blocks that have these can't be constant. 440 CurBlock->hasBlockDeclRefExprs = true; 441 442 // If we have nested blocks, the decl may be declared in an outer block (in 443 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 444 // be defined outside all of the current blocks (in which case the blocks do 445 // all get the bit). Walk the nesting chain. 446 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 447 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 448 449 if (!NextBlock) 450 continue; 451 452 // If we found the defining block for the variable, don't mark the block as 453 // having a reference outside it. 454 if (NextBlock->TheDecl == VD->getDeclContext()) 455 break; 456 457 // Otherwise, the DeclRef from the inner block causes the outer one to need 458 // a snapshot as well. 459 NextBlock->hasBlockDeclRefExprs = true; 460 } 461 462 return true; 463} 464 465 466ExprResult 467Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, SourceLocation Loc, 468 const CXXScopeSpec *SS) { 469 DeclarationNameInfo NameInfo(D->getDeclName(), Loc); 470 return BuildDeclRefExpr(D, Ty, NameInfo, SS); 471} 472 473/// BuildDeclRefExpr - Build a DeclRefExpr. 474ExprResult 475Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, 476 const DeclarationNameInfo &NameInfo, 477 const CXXScopeSpec *SS) { 478 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 479 Diag(NameInfo.getLoc(), 480 diag::err_auto_variable_cannot_appear_in_own_initializer) 481 << D->getDeclName(); 482 return ExprError(); 483 } 484 485 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 486 if (isa<NonTypeTemplateParmDecl>(VD)) { 487 // Non-type template parameters can be referenced anywhere they are 488 // visible. 489 Ty = Ty.getNonLValueExprType(Context); 490 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 491 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 492 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 493 Diag(NameInfo.getLoc(), 494 diag::err_reference_to_local_var_in_enclosing_function) 495 << D->getIdentifier() << FD->getDeclName(); 496 Diag(D->getLocation(), diag::note_local_variable_declared_here) 497 << D->getIdentifier(); 498 return ExprError(); 499 } 500 } 501 } 502 } 503 504 MarkDeclarationReferenced(NameInfo.getLoc(), D); 505 506 return Owned(DeclRefExpr::Create(Context, 507 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 508 SS? SS->getRange() : SourceRange(), 509 D, NameInfo, Ty)); 510} 511 512/// \brief Given a field that represents a member of an anonymous 513/// struct/union, build the path from that field's context to the 514/// actual member. 515/// 516/// Construct the sequence of field member references we'll have to 517/// perform to get to the field in the anonymous union/struct. The 518/// list of members is built from the field outward, so traverse it 519/// backwards to go from an object in the current context to the field 520/// we found. 521/// 522/// \returns The variable from which the field access should begin, 523/// for an anonymous struct/union that is not a member of another 524/// class. Otherwise, returns NULL. 525VarDecl *Sema::BuildAnonymousStructUnionMemberPath(FieldDecl *Field, 526 llvm::SmallVectorImpl<FieldDecl *> &Path) { 527 assert(Field->getDeclContext()->isRecord() && 528 cast<RecordDecl>(Field->getDeclContext())->isAnonymousStructOrUnion() 529 && "Field must be stored inside an anonymous struct or union"); 530 531 Path.push_back(Field); 532 VarDecl *BaseObject = 0; 533 DeclContext *Ctx = Field->getDeclContext(); 534 do { 535 RecordDecl *Record = cast<RecordDecl>(Ctx); 536 ValueDecl *AnonObject = Record->getAnonymousStructOrUnionObject(); 537 if (FieldDecl *AnonField = dyn_cast<FieldDecl>(AnonObject)) 538 Path.push_back(AnonField); 539 else { 540 BaseObject = cast<VarDecl>(AnonObject); 541 break; 542 } 543 Ctx = Ctx->getParent(); 544 } while (Ctx->isRecord() && 545 cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()); 546 547 return BaseObject; 548} 549 550ExprResult 551Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 552 FieldDecl *Field, 553 Expr *BaseObjectExpr, 554 SourceLocation OpLoc) { 555 llvm::SmallVector<FieldDecl *, 4> AnonFields; 556 VarDecl *BaseObject = BuildAnonymousStructUnionMemberPath(Field, 557 AnonFields); 558 559 // Build the expression that refers to the base object, from 560 // which we will build a sequence of member references to each 561 // of the anonymous union objects and, eventually, the field we 562 // found via name lookup. 563 bool BaseObjectIsPointer = false; 564 Qualifiers BaseQuals; 565 if (BaseObject) { 566 // BaseObject is an anonymous struct/union variable (and is, 567 // therefore, not part of another non-anonymous record). 568 MarkDeclarationReferenced(Loc, BaseObject); 569 BaseObjectExpr = new (Context) DeclRefExpr(BaseObject,BaseObject->getType(), 570 SourceLocation()); 571 BaseQuals 572 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 573 } else if (BaseObjectExpr) { 574 // The caller provided the base object expression. Determine 575 // whether its a pointer and whether it adds any qualifiers to the 576 // anonymous struct/union fields we're looking into. 577 QualType ObjectType = BaseObjectExpr->getType(); 578 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 579 BaseObjectIsPointer = true; 580 ObjectType = ObjectPtr->getPointeeType(); 581 } 582 BaseQuals 583 = Context.getCanonicalType(ObjectType).getQualifiers(); 584 } else { 585 // We've found a member of an anonymous struct/union that is 586 // inside a non-anonymous struct/union, so in a well-formed 587 // program our base object expression is "this". 588 DeclContext *DC = getFunctionLevelDeclContext(); 589 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 590 if (!MD->isStatic()) { 591 QualType AnonFieldType 592 = Context.getTagDeclType( 593 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 594 QualType ThisType = Context.getTagDeclType(MD->getParent()); 595 if ((Context.getCanonicalType(AnonFieldType) 596 == Context.getCanonicalType(ThisType)) || 597 IsDerivedFrom(ThisType, AnonFieldType)) { 598 // Our base object expression is "this". 599 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 600 MD->getThisType(Context), 601 /*isImplicit=*/true); 602 BaseObjectIsPointer = true; 603 } 604 } else { 605 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 606 << Field->getDeclName()); 607 } 608 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 609 } 610 611 if (!BaseObjectExpr) 612 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 613 << Field->getDeclName()); 614 } 615 616 // Build the implicit member references to the field of the 617 // anonymous struct/union. 618 Expr *Result = BaseObjectExpr; 619 Qualifiers ResultQuals = BaseQuals; 620 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 621 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 622 FI != FIEnd; ++FI) { 623 QualType MemberType = (*FI)->getType(); 624 Qualifiers MemberTypeQuals = 625 Context.getCanonicalType(MemberType).getQualifiers(); 626 627 // CVR attributes from the base are picked up by members, 628 // except that 'mutable' members don't pick up 'const'. 629 if ((*FI)->isMutable()) 630 ResultQuals.removeConst(); 631 632 // GC attributes are never picked up by members. 633 ResultQuals.removeObjCGCAttr(); 634 635 // TR 18037 does not allow fields to be declared with address spaces. 636 assert(!MemberTypeQuals.hasAddressSpace()); 637 638 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 639 if (NewQuals != MemberTypeQuals) 640 MemberType = Context.getQualifiedType(MemberType, NewQuals); 641 642 MarkDeclarationReferenced(Loc, *FI); 643 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 644 // FIXME: Might this end up being a qualified name? 645 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 646 OpLoc, MemberType); 647 BaseObjectIsPointer = false; 648 ResultQuals = NewQuals; 649 } 650 651 return Owned(Result); 652} 653 654/// Decomposes the given name into a DeclarationNameInfo, its location, and 655/// possibly a list of template arguments. 656/// 657/// If this produces template arguments, it is permitted to call 658/// DecomposeTemplateName. 659/// 660/// This actually loses a lot of source location information for 661/// non-standard name kinds; we should consider preserving that in 662/// some way. 663static void DecomposeUnqualifiedId(Sema &SemaRef, 664 const UnqualifiedId &Id, 665 TemplateArgumentListInfo &Buffer, 666 DeclarationNameInfo &NameInfo, 667 const TemplateArgumentListInfo *&TemplateArgs) { 668 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 669 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 670 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 671 672 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 673 Id.TemplateId->getTemplateArgs(), 674 Id.TemplateId->NumArgs); 675 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 676 TemplateArgsPtr.release(); 677 678 TemplateName TName = Id.TemplateId->Template.get(); 679 SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; 680 NameInfo = SemaRef.Context.getNameForTemplate(TName, TNameLoc); 681 TemplateArgs = &Buffer; 682 } else { 683 NameInfo = SemaRef.GetNameFromUnqualifiedId(Id); 684 TemplateArgs = 0; 685 } 686} 687 688/// Determines whether the given record is "fully-formed" at the given 689/// location, i.e. whether a qualified lookup into it is assured of 690/// getting consistent results already. 691static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 692 if (!Record->hasDefinition()) 693 return false; 694 695 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 696 E = Record->bases_end(); I != E; ++I) { 697 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 698 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 699 if (!BaseRT) return false; 700 701 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 702 if (!BaseRecord->hasDefinition() || 703 !IsFullyFormedScope(SemaRef, BaseRecord)) 704 return false; 705 } 706 707 return true; 708} 709 710/// Determines if the given class is provably not derived from all of 711/// the prospective base classes. 712static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 713 CXXRecordDecl *Record, 714 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 715 if (Bases.count(Record->getCanonicalDecl())) 716 return false; 717 718 RecordDecl *RD = Record->getDefinition(); 719 if (!RD) return false; 720 Record = cast<CXXRecordDecl>(RD); 721 722 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 723 E = Record->bases_end(); I != E; ++I) { 724 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 725 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 726 if (!BaseRT) return false; 727 728 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 729 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 730 return false; 731 } 732 733 return true; 734} 735 736enum IMAKind { 737 /// The reference is definitely not an instance member access. 738 IMA_Static, 739 740 /// The reference may be an implicit instance member access. 741 IMA_Mixed, 742 743 /// The reference may be to an instance member, but it is invalid if 744 /// so, because the context is not an instance method. 745 IMA_Mixed_StaticContext, 746 747 /// The reference may be to an instance member, but it is invalid if 748 /// so, because the context is from an unrelated class. 749 IMA_Mixed_Unrelated, 750 751 /// The reference is definitely an implicit instance member access. 752 IMA_Instance, 753 754 /// The reference may be to an unresolved using declaration. 755 IMA_Unresolved, 756 757 /// The reference may be to an unresolved using declaration and the 758 /// context is not an instance method. 759 IMA_Unresolved_StaticContext, 760 761 /// The reference is to a member of an anonymous structure in a 762 /// non-class context. 763 IMA_AnonymousMember, 764 765 /// All possible referrents are instance members and the current 766 /// context is not an instance method. 767 IMA_Error_StaticContext, 768 769 /// All possible referrents are instance members of an unrelated 770 /// class. 771 IMA_Error_Unrelated 772}; 773 774/// The given lookup names class member(s) and is not being used for 775/// an address-of-member expression. Classify the type of access 776/// according to whether it's possible that this reference names an 777/// instance member. This is best-effort; it is okay to 778/// conservatively answer "yes", in which case some errors will simply 779/// not be caught until template-instantiation. 780static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 781 const LookupResult &R) { 782 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 783 784 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 785 bool isStaticContext = 786 (!isa<CXXMethodDecl>(DC) || 787 cast<CXXMethodDecl>(DC)->isStatic()); 788 789 if (R.isUnresolvableResult()) 790 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 791 792 // Collect all the declaring classes of instance members we find. 793 bool hasNonInstance = false; 794 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 795 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 796 NamedDecl *D = *I; 797 if (D->isCXXInstanceMember()) { 798 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 799 800 // If this is a member of an anonymous record, move out to the 801 // innermost non-anonymous struct or union. If there isn't one, 802 // that's a special case. 803 while (R->isAnonymousStructOrUnion()) { 804 R = dyn_cast<CXXRecordDecl>(R->getParent()); 805 if (!R) return IMA_AnonymousMember; 806 } 807 Classes.insert(R->getCanonicalDecl()); 808 } 809 else 810 hasNonInstance = true; 811 } 812 813 // If we didn't find any instance members, it can't be an implicit 814 // member reference. 815 if (Classes.empty()) 816 return IMA_Static; 817 818 // If the current context is not an instance method, it can't be 819 // an implicit member reference. 820 if (isStaticContext) 821 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 822 823 // If we can prove that the current context is unrelated to all the 824 // declaring classes, it can't be an implicit member reference (in 825 // which case it's an error if any of those members are selected). 826 if (IsProvablyNotDerivedFrom(SemaRef, 827 cast<CXXMethodDecl>(DC)->getParent(), 828 Classes)) 829 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 830 831 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 832} 833 834/// Diagnose a reference to a field with no object available. 835static void DiagnoseInstanceReference(Sema &SemaRef, 836 const CXXScopeSpec &SS, 837 const LookupResult &R) { 838 SourceLocation Loc = R.getNameLoc(); 839 SourceRange Range(Loc); 840 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 841 842 if (R.getAsSingle<FieldDecl>()) { 843 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 844 if (MD->isStatic()) { 845 // "invalid use of member 'x' in static member function" 846 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 847 << Range << R.getLookupName(); 848 return; 849 } 850 } 851 852 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 853 << R.getLookupName() << Range; 854 return; 855 } 856 857 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 858} 859 860/// Diagnose an empty lookup. 861/// 862/// \return false if new lookup candidates were found 863bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 864 CorrectTypoContext CTC) { 865 DeclarationName Name = R.getLookupName(); 866 867 unsigned diagnostic = diag::err_undeclared_var_use; 868 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 869 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 870 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 871 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 872 diagnostic = diag::err_undeclared_use; 873 diagnostic_suggest = diag::err_undeclared_use_suggest; 874 } 875 876 // If the original lookup was an unqualified lookup, fake an 877 // unqualified lookup. This is useful when (for example) the 878 // original lookup would not have found something because it was a 879 // dependent name. 880 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 881 DC; DC = DC->getParent()) { 882 if (isa<CXXRecordDecl>(DC)) { 883 LookupQualifiedName(R, DC); 884 885 if (!R.empty()) { 886 // Don't give errors about ambiguities in this lookup. 887 R.suppressDiagnostics(); 888 889 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 890 bool isInstance = CurMethod && 891 CurMethod->isInstance() && 892 DC == CurMethod->getParent(); 893 894 // Give a code modification hint to insert 'this->'. 895 // TODO: fixit for inserting 'Base<T>::' in the other cases. 896 // Actually quite difficult! 897 if (isInstance) { 898 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 899 CallsUndergoingInstantiation.back()->getCallee()); 900 CXXMethodDecl *DepMethod = cast_or_null<CXXMethodDecl>( 901 CurMethod->getInstantiatedFromMemberFunction()); 902 if (DepMethod) { 903 Diag(R.getNameLoc(), diagnostic) << Name 904 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 905 QualType DepThisType = DepMethod->getThisType(Context); 906 CXXThisExpr *DepThis = new (Context) CXXThisExpr( 907 R.getNameLoc(), DepThisType, false); 908 TemplateArgumentListInfo TList; 909 if (ULE->hasExplicitTemplateArgs()) 910 ULE->copyTemplateArgumentsInto(TList); 911 CXXDependentScopeMemberExpr *DepExpr = 912 CXXDependentScopeMemberExpr::Create( 913 Context, DepThis, DepThisType, true, SourceLocation(), 914 ULE->getQualifier(), ULE->getQualifierRange(), NULL, 915 R.getLookupNameInfo(), &TList); 916 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 917 } else { 918 // FIXME: we should be able to handle this case too. It is correct 919 // to add this-> here. This is a workaround for PR7947. 920 Diag(R.getNameLoc(), diagnostic) << Name; 921 } 922 } else { 923 Diag(R.getNameLoc(), diagnostic) << Name; 924 } 925 926 // Do we really want to note all of these? 927 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 928 Diag((*I)->getLocation(), diag::note_dependent_var_use); 929 930 // Tell the callee to try to recover. 931 return false; 932 } 933 934 R.clear(); 935 } 936 } 937 938 // We didn't find anything, so try to correct for a typo. 939 DeclarationName Corrected; 940 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 941 if (!R.empty()) { 942 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 943 if (SS.isEmpty()) 944 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 945 << FixItHint::CreateReplacement(R.getNameLoc(), 946 R.getLookupName().getAsString()); 947 else 948 Diag(R.getNameLoc(), diag::err_no_member_suggest) 949 << Name << computeDeclContext(SS, false) << R.getLookupName() 950 << SS.getRange() 951 << FixItHint::CreateReplacement(R.getNameLoc(), 952 R.getLookupName().getAsString()); 953 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 954 Diag(ND->getLocation(), diag::note_previous_decl) 955 << ND->getDeclName(); 956 957 // Tell the callee to try to recover. 958 return false; 959 } 960 961 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 962 // FIXME: If we ended up with a typo for a type name or 963 // Objective-C class name, we're in trouble because the parser 964 // is in the wrong place to recover. Suggest the typo 965 // correction, but don't make it a fix-it since we're not going 966 // to recover well anyway. 967 if (SS.isEmpty()) 968 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 969 else 970 Diag(R.getNameLoc(), diag::err_no_member_suggest) 971 << Name << computeDeclContext(SS, false) << R.getLookupName() 972 << SS.getRange(); 973 974 // Don't try to recover; it won't work. 975 return true; 976 } 977 } else { 978 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 979 // because we aren't able to recover. 980 if (SS.isEmpty()) 981 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 982 else 983 Diag(R.getNameLoc(), diag::err_no_member_suggest) 984 << Name << computeDeclContext(SS, false) << Corrected 985 << SS.getRange(); 986 return true; 987 } 988 R.clear(); 989 } 990 991 // Emit a special diagnostic for failed member lookups. 992 // FIXME: computing the declaration context might fail here (?) 993 if (!SS.isEmpty()) { 994 Diag(R.getNameLoc(), diag::err_no_member) 995 << Name << computeDeclContext(SS, false) 996 << SS.getRange(); 997 return true; 998 } 999 1000 // Give up, we can't recover. 1001 Diag(R.getNameLoc(), diagnostic) << Name; 1002 return true; 1003} 1004 1005static ObjCPropertyDecl *OkToSynthesizeProvisionalIvar(Sema &SemaRef, 1006 IdentifierInfo *II, 1007 SourceLocation NameLoc) { 1008 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1009 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1010 if (!IDecl) 1011 return 0; 1012 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1013 if (!ClassImpDecl) 1014 return 0; 1015 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1016 if (!property) 1017 return 0; 1018 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1019 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic) 1020 return 0; 1021 return property; 1022} 1023 1024static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1025 LookupResult &Lookup, 1026 IdentifierInfo *II, 1027 SourceLocation NameLoc) { 1028 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1029 bool LookForIvars; 1030 if (Lookup.empty()) 1031 LookForIvars = true; 1032 else if (CurMeth->isClassMethod()) 1033 LookForIvars = false; 1034 else 1035 LookForIvars = (Lookup.isSingleResult() && 1036 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1037 if (!LookForIvars) 1038 return 0; 1039 1040 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1041 if (!IDecl) 1042 return 0; 1043 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1044 if (!ClassImpDecl) 1045 return 0; 1046 bool DynamicImplSeen = false; 1047 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1048 if (!property) 1049 return 0; 1050 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1051 DynamicImplSeen = 1052 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1053 if (!DynamicImplSeen) { 1054 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1055 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1056 NameLoc, 1057 II, PropType, /*Dinfo=*/0, 1058 ObjCIvarDecl::Protected, 1059 (Expr *)0, true); 1060 ClassImpDecl->addDecl(Ivar); 1061 IDecl->makeDeclVisibleInContext(Ivar, false); 1062 property->setPropertyIvarDecl(Ivar); 1063 return Ivar; 1064 } 1065 return 0; 1066} 1067 1068ExprResult Sema::ActOnIdExpression(Scope *S, 1069 CXXScopeSpec &SS, 1070 UnqualifiedId &Id, 1071 bool HasTrailingLParen, 1072 bool isAddressOfOperand) { 1073 assert(!(isAddressOfOperand && HasTrailingLParen) && 1074 "cannot be direct & operand and have a trailing lparen"); 1075 1076 if (SS.isInvalid()) 1077 return ExprError(); 1078 1079 TemplateArgumentListInfo TemplateArgsBuffer; 1080 1081 // Decompose the UnqualifiedId into the following data. 1082 DeclarationNameInfo NameInfo; 1083 const TemplateArgumentListInfo *TemplateArgs; 1084 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, NameInfo, TemplateArgs); 1085 1086 DeclarationName Name = NameInfo.getName(); 1087 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1088 SourceLocation NameLoc = NameInfo.getLoc(); 1089 1090 // C++ [temp.dep.expr]p3: 1091 // An id-expression is type-dependent if it contains: 1092 // -- an identifier that was declared with a dependent type, 1093 // (note: handled after lookup) 1094 // -- a template-id that is dependent, 1095 // (note: handled in BuildTemplateIdExpr) 1096 // -- a conversion-function-id that specifies a dependent type, 1097 // -- a nested-name-specifier that contains a class-name that 1098 // names a dependent type. 1099 // Determine whether this is a member of an unknown specialization; 1100 // we need to handle these differently. 1101 bool DependentID = false; 1102 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1103 Name.getCXXNameType()->isDependentType()) { 1104 DependentID = true; 1105 } else if (SS.isSet()) { 1106 DeclContext *DC = computeDeclContext(SS, false); 1107 if (DC) { 1108 if (RequireCompleteDeclContext(SS, DC)) 1109 return ExprError(); 1110 // FIXME: We should be checking whether DC is the current instantiation. 1111 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 1112 DependentID = !IsFullyFormedScope(*this, RD); 1113 } else { 1114 DependentID = true; 1115 } 1116 } 1117 1118 if (DependentID) { 1119 return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, 1120 TemplateArgs); 1121 } 1122 bool IvarLookupFollowUp = false; 1123 // Perform the required lookup. 1124 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1125 if (TemplateArgs) { 1126 // Lookup the template name again to correctly establish the context in 1127 // which it was found. This is really unfortunate as we already did the 1128 // lookup to determine that it was a template name in the first place. If 1129 // this becomes a performance hit, we can work harder to preserve those 1130 // results until we get here but it's likely not worth it. 1131 bool MemberOfUnknownSpecialization; 1132 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1133 MemberOfUnknownSpecialization); 1134 } else { 1135 IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1136 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1137 1138 // If this reference is in an Objective-C method, then we need to do 1139 // some special Objective-C lookup, too. 1140 if (IvarLookupFollowUp) { 1141 ExprResult E(LookupInObjCMethod(R, S, II, true)); 1142 if (E.isInvalid()) 1143 return ExprError(); 1144 1145 Expr *Ex = E.takeAs<Expr>(); 1146 if (Ex) return Owned(Ex); 1147 // Synthesize ivars lazily 1148 if (getLangOptions().ObjCNonFragileABI2) { 1149 if (SynthesizeProvisionalIvar(*this, R, II, NameLoc)) 1150 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1151 isAddressOfOperand); 1152 } 1153 // for further use, this must be set to false if in class method. 1154 IvarLookupFollowUp = getCurMethodDecl()->isInstanceMethod(); 1155 } 1156 } 1157 1158 if (R.isAmbiguous()) 1159 return ExprError(); 1160 1161 // Determine whether this name might be a candidate for 1162 // argument-dependent lookup. 1163 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1164 1165 if (R.empty() && !ADL) { 1166 // Otherwise, this could be an implicitly declared function reference (legal 1167 // in C90, extension in C99, forbidden in C++). 1168 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1169 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1170 if (D) R.addDecl(D); 1171 } 1172 1173 // If this name wasn't predeclared and if this is not a function 1174 // call, diagnose the problem. 1175 if (R.empty()) { 1176 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1177 return ExprError(); 1178 1179 assert(!R.empty() && 1180 "DiagnoseEmptyLookup returned false but added no results"); 1181 1182 // If we found an Objective-C instance variable, let 1183 // LookupInObjCMethod build the appropriate expression to 1184 // reference the ivar. 1185 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1186 R.clear(); 1187 ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1188 assert(E.isInvalid() || E.get()); 1189 return move(E); 1190 } 1191 } 1192 } 1193 1194 // This is guaranteed from this point on. 1195 assert(!R.empty() || ADL); 1196 1197 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1198 if (getLangOptions().ObjCNonFragileABI && IvarLookupFollowUp && 1199 !getLangOptions().ObjCNonFragileABI2 && 1200 Var->isFileVarDecl()) { 1201 ObjCPropertyDecl *Property = 1202 OkToSynthesizeProvisionalIvar(*this, II, NameLoc); 1203 if (Property) { 1204 Diag(NameLoc, diag::warn_ivar_variable_conflict) << Var->getDeclName(); 1205 Diag(Property->getLocation(), diag::note_property_declare); 1206 Diag(Var->getLocation(), diag::note_global_declared_at); 1207 } 1208 } 1209 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1210 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1211 // C99 DR 316 says that, if a function type comes from a 1212 // function definition (without a prototype), that type is only 1213 // used for checking compatibility. Therefore, when referencing 1214 // the function, we pretend that we don't have the full function 1215 // type. 1216 if (DiagnoseUseOfDecl(Func, NameLoc)) 1217 return ExprError(); 1218 1219 QualType T = Func->getType(); 1220 QualType NoProtoType = T; 1221 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1222 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1223 Proto->getExtInfo()); 1224 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1225 } 1226 } 1227 1228 // Check whether this might be a C++ implicit instance member access. 1229 // C++ [class.mfct.non-static]p3: 1230 // When an id-expression that is not part of a class member access 1231 // syntax and not used to form a pointer to member is used in the 1232 // body of a non-static member function of class X, if name lookup 1233 // resolves the name in the id-expression to a non-static non-type 1234 // member of some class C, the id-expression is transformed into a 1235 // class member access expression using (*this) as the 1236 // postfix-expression to the left of the . operator. 1237 // 1238 // But we don't actually need to do this for '&' operands if R 1239 // resolved to a function or overloaded function set, because the 1240 // expression is ill-formed if it actually works out to be a 1241 // non-static member function: 1242 // 1243 // C++ [expr.ref]p4: 1244 // Otherwise, if E1.E2 refers to a non-static member function. . . 1245 // [t]he expression can be used only as the left-hand operand of a 1246 // member function call. 1247 // 1248 // There are other safeguards against such uses, but it's important 1249 // to get this right here so that we don't end up making a 1250 // spuriously dependent expression if we're inside a dependent 1251 // instance method. 1252 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1253 bool MightBeImplicitMember; 1254 if (!isAddressOfOperand) 1255 MightBeImplicitMember = true; 1256 else if (!SS.isEmpty()) 1257 MightBeImplicitMember = false; 1258 else if (R.isOverloadedResult()) 1259 MightBeImplicitMember = false; 1260 else if (R.isUnresolvableResult()) 1261 MightBeImplicitMember = true; 1262 else 1263 MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()); 1264 1265 if (MightBeImplicitMember) 1266 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1267 } 1268 1269 if (TemplateArgs) 1270 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1271 1272 return BuildDeclarationNameExpr(SS, R, ADL); 1273} 1274 1275/// Builds an expression which might be an implicit member expression. 1276ExprResult 1277Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1278 LookupResult &R, 1279 const TemplateArgumentListInfo *TemplateArgs) { 1280 switch (ClassifyImplicitMemberAccess(*this, R)) { 1281 case IMA_Instance: 1282 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1283 1284 case IMA_AnonymousMember: 1285 assert(R.isSingleResult()); 1286 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1287 R.getAsSingle<FieldDecl>()); 1288 1289 case IMA_Mixed: 1290 case IMA_Mixed_Unrelated: 1291 case IMA_Unresolved: 1292 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1293 1294 case IMA_Static: 1295 case IMA_Mixed_StaticContext: 1296 case IMA_Unresolved_StaticContext: 1297 if (TemplateArgs) 1298 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1299 return BuildDeclarationNameExpr(SS, R, false); 1300 1301 case IMA_Error_StaticContext: 1302 case IMA_Error_Unrelated: 1303 DiagnoseInstanceReference(*this, SS, R); 1304 return ExprError(); 1305 } 1306 1307 llvm_unreachable("unexpected instance member access kind"); 1308 return ExprError(); 1309} 1310 1311/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1312/// declaration name, generally during template instantiation. 1313/// There's a large number of things which don't need to be done along 1314/// this path. 1315ExprResult 1316Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1317 const DeclarationNameInfo &NameInfo) { 1318 DeclContext *DC; 1319 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1320 return BuildDependentDeclRefExpr(SS, NameInfo, 0); 1321 1322 if (RequireCompleteDeclContext(SS, DC)) 1323 return ExprError(); 1324 1325 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1326 LookupQualifiedName(R, DC); 1327 1328 if (R.isAmbiguous()) 1329 return ExprError(); 1330 1331 if (R.empty()) { 1332 Diag(NameInfo.getLoc(), diag::err_no_member) 1333 << NameInfo.getName() << DC << SS.getRange(); 1334 return ExprError(); 1335 } 1336 1337 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1338} 1339 1340/// LookupInObjCMethod - The parser has read a name in, and Sema has 1341/// detected that we're currently inside an ObjC method. Perform some 1342/// additional lookup. 1343/// 1344/// Ideally, most of this would be done by lookup, but there's 1345/// actually quite a lot of extra work involved. 1346/// 1347/// Returns a null sentinel to indicate trivial success. 1348ExprResult 1349Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1350 IdentifierInfo *II, bool AllowBuiltinCreation) { 1351 SourceLocation Loc = Lookup.getNameLoc(); 1352 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1353 1354 // There are two cases to handle here. 1) scoped lookup could have failed, 1355 // in which case we should look for an ivar. 2) scoped lookup could have 1356 // found a decl, but that decl is outside the current instance method (i.e. 1357 // a global variable). In these two cases, we do a lookup for an ivar with 1358 // this name, if the lookup sucedes, we replace it our current decl. 1359 1360 // If we're in a class method, we don't normally want to look for 1361 // ivars. But if we don't find anything else, and there's an 1362 // ivar, that's an error. 1363 bool IsClassMethod = CurMethod->isClassMethod(); 1364 1365 bool LookForIvars; 1366 if (Lookup.empty()) 1367 LookForIvars = true; 1368 else if (IsClassMethod) 1369 LookForIvars = false; 1370 else 1371 LookForIvars = (Lookup.isSingleResult() && 1372 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1373 ObjCInterfaceDecl *IFace = 0; 1374 if (LookForIvars) { 1375 IFace = CurMethod->getClassInterface(); 1376 ObjCInterfaceDecl *ClassDeclared; 1377 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1378 // Diagnose using an ivar in a class method. 1379 if (IsClassMethod) 1380 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1381 << IV->getDeclName()); 1382 1383 // If we're referencing an invalid decl, just return this as a silent 1384 // error node. The error diagnostic was already emitted on the decl. 1385 if (IV->isInvalidDecl()) 1386 return ExprError(); 1387 1388 // Check if referencing a field with __attribute__((deprecated)). 1389 if (DiagnoseUseOfDecl(IV, Loc)) 1390 return ExprError(); 1391 1392 // Diagnose the use of an ivar outside of the declaring class. 1393 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1394 ClassDeclared != IFace) 1395 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1396 1397 // FIXME: This should use a new expr for a direct reference, don't 1398 // turn this into Self->ivar, just return a BareIVarExpr or something. 1399 IdentifierInfo &II = Context.Idents.get("self"); 1400 UnqualifiedId SelfName; 1401 SelfName.setIdentifier(&II, SourceLocation()); 1402 CXXScopeSpec SelfScopeSpec; 1403 ExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1404 SelfName, false, false); 1405 MarkDeclarationReferenced(Loc, IV); 1406 return Owned(new (Context) 1407 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1408 SelfExpr.takeAs<Expr>(), true, true)); 1409 } 1410 } else if (CurMethod->isInstanceMethod()) { 1411 // We should warn if a local variable hides an ivar. 1412 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1413 ObjCInterfaceDecl *ClassDeclared; 1414 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1415 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1416 IFace == ClassDeclared) 1417 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1418 } 1419 } 1420 1421 if (Lookup.empty() && II && AllowBuiltinCreation) { 1422 // FIXME. Consolidate this with similar code in LookupName. 1423 if (unsigned BuiltinID = II->getBuiltinID()) { 1424 if (!(getLangOptions().CPlusPlus && 1425 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1426 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1427 S, Lookup.isForRedeclaration(), 1428 Lookup.getNameLoc()); 1429 if (D) Lookup.addDecl(D); 1430 } 1431 } 1432 } 1433 // Sentinel value saying that we didn't do anything special. 1434 return Owned((Expr*) 0); 1435} 1436 1437/// \brief Cast a base object to a member's actual type. 1438/// 1439/// Logically this happens in three phases: 1440/// 1441/// * First we cast from the base type to the naming class. 1442/// The naming class is the class into which we were looking 1443/// when we found the member; it's the qualifier type if a 1444/// qualifier was provided, and otherwise it's the base type. 1445/// 1446/// * Next we cast from the naming class to the declaring class. 1447/// If the member we found was brought into a class's scope by 1448/// a using declaration, this is that class; otherwise it's 1449/// the class declaring the member. 1450/// 1451/// * Finally we cast from the declaring class to the "true" 1452/// declaring class of the member. This conversion does not 1453/// obey access control. 1454bool 1455Sema::PerformObjectMemberConversion(Expr *&From, 1456 NestedNameSpecifier *Qualifier, 1457 NamedDecl *FoundDecl, 1458 NamedDecl *Member) { 1459 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1460 if (!RD) 1461 return false; 1462 1463 QualType DestRecordType; 1464 QualType DestType; 1465 QualType FromRecordType; 1466 QualType FromType = From->getType(); 1467 bool PointerConversions = false; 1468 if (isa<FieldDecl>(Member)) { 1469 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1470 1471 if (FromType->getAs<PointerType>()) { 1472 DestType = Context.getPointerType(DestRecordType); 1473 FromRecordType = FromType->getPointeeType(); 1474 PointerConversions = true; 1475 } else { 1476 DestType = DestRecordType; 1477 FromRecordType = FromType; 1478 } 1479 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1480 if (Method->isStatic()) 1481 return false; 1482 1483 DestType = Method->getThisType(Context); 1484 DestRecordType = DestType->getPointeeType(); 1485 1486 if (FromType->getAs<PointerType>()) { 1487 FromRecordType = FromType->getPointeeType(); 1488 PointerConversions = true; 1489 } else { 1490 FromRecordType = FromType; 1491 DestType = DestRecordType; 1492 } 1493 } else { 1494 // No conversion necessary. 1495 return false; 1496 } 1497 1498 if (DestType->isDependentType() || FromType->isDependentType()) 1499 return false; 1500 1501 // If the unqualified types are the same, no conversion is necessary. 1502 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1503 return false; 1504 1505 SourceRange FromRange = From->getSourceRange(); 1506 SourceLocation FromLoc = FromRange.getBegin(); 1507 1508 ExprValueKind VK = CastCategory(From); 1509 1510 // C++ [class.member.lookup]p8: 1511 // [...] Ambiguities can often be resolved by qualifying a name with its 1512 // class name. 1513 // 1514 // If the member was a qualified name and the qualified referred to a 1515 // specific base subobject type, we'll cast to that intermediate type 1516 // first and then to the object in which the member is declared. That allows 1517 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1518 // 1519 // class Base { public: int x; }; 1520 // class Derived1 : public Base { }; 1521 // class Derived2 : public Base { }; 1522 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1523 // 1524 // void VeryDerived::f() { 1525 // x = 17; // error: ambiguous base subobjects 1526 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1527 // } 1528 if (Qualifier) { 1529 QualType QType = QualType(Qualifier->getAsType(), 0); 1530 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1531 assert(QType->isRecordType() && "lookup done with non-record type"); 1532 1533 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1534 1535 // In C++98, the qualifier type doesn't actually have to be a base 1536 // type of the object type, in which case we just ignore it. 1537 // Otherwise build the appropriate casts. 1538 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1539 CXXCastPath BasePath; 1540 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1541 FromLoc, FromRange, &BasePath)) 1542 return true; 1543 1544 if (PointerConversions) 1545 QType = Context.getPointerType(QType); 1546 ImpCastExprToType(From, QType, CK_UncheckedDerivedToBase, 1547 VK, &BasePath); 1548 1549 FromType = QType; 1550 FromRecordType = QRecordType; 1551 1552 // If the qualifier type was the same as the destination type, 1553 // we're done. 1554 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1555 return false; 1556 } 1557 } 1558 1559 bool IgnoreAccess = false; 1560 1561 // If we actually found the member through a using declaration, cast 1562 // down to the using declaration's type. 1563 // 1564 // Pointer equality is fine here because only one declaration of a 1565 // class ever has member declarations. 1566 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1567 assert(isa<UsingShadowDecl>(FoundDecl)); 1568 QualType URecordType = Context.getTypeDeclType( 1569 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1570 1571 // We only need to do this if the naming-class to declaring-class 1572 // conversion is non-trivial. 1573 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1574 assert(IsDerivedFrom(FromRecordType, URecordType)); 1575 CXXCastPath BasePath; 1576 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1577 FromLoc, FromRange, &BasePath)) 1578 return true; 1579 1580 QualType UType = URecordType; 1581 if (PointerConversions) 1582 UType = Context.getPointerType(UType); 1583 ImpCastExprToType(From, UType, CK_UncheckedDerivedToBase, 1584 VK, &BasePath); 1585 FromType = UType; 1586 FromRecordType = URecordType; 1587 } 1588 1589 // We don't do access control for the conversion from the 1590 // declaring class to the true declaring class. 1591 IgnoreAccess = true; 1592 } 1593 1594 CXXCastPath BasePath; 1595 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1596 FromLoc, FromRange, &BasePath, 1597 IgnoreAccess)) 1598 return true; 1599 1600 ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase, 1601 VK, &BasePath); 1602 return false; 1603} 1604 1605/// \brief Build a MemberExpr AST node. 1606static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1607 const CXXScopeSpec &SS, ValueDecl *Member, 1608 DeclAccessPair FoundDecl, 1609 const DeclarationNameInfo &MemberNameInfo, 1610 QualType Ty, 1611 const TemplateArgumentListInfo *TemplateArgs = 0) { 1612 NestedNameSpecifier *Qualifier = 0; 1613 SourceRange QualifierRange; 1614 if (SS.isSet()) { 1615 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1616 QualifierRange = SS.getRange(); 1617 } 1618 1619 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1620 Member, FoundDecl, MemberNameInfo, 1621 TemplateArgs, Ty); 1622} 1623 1624/// Builds an implicit member access expression. The current context 1625/// is known to be an instance method, and the given unqualified lookup 1626/// set is known to contain only instance members, at least one of which 1627/// is from an appropriate type. 1628ExprResult 1629Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1630 LookupResult &R, 1631 const TemplateArgumentListInfo *TemplateArgs, 1632 bool IsKnownInstance) { 1633 assert(!R.empty() && !R.isAmbiguous()); 1634 1635 SourceLocation Loc = R.getNameLoc(); 1636 1637 // We may have found a field within an anonymous union or struct 1638 // (C++ [class.union]). 1639 // FIXME: This needs to happen post-isImplicitMemberReference? 1640 // FIXME: template-ids inside anonymous structs? 1641 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1642 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1643 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1644 1645 // If this is known to be an instance access, go ahead and build a 1646 // 'this' expression now. 1647 DeclContext *DC = getFunctionLevelDeclContext(); 1648 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 1649 Expr *This = 0; // null signifies implicit access 1650 if (IsKnownInstance) { 1651 SourceLocation Loc = R.getNameLoc(); 1652 if (SS.getRange().isValid()) 1653 Loc = SS.getRange().getBegin(); 1654 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1655 } 1656 1657 return BuildMemberReferenceExpr(This, ThisType, 1658 /*OpLoc*/ SourceLocation(), 1659 /*IsArrow*/ true, 1660 SS, 1661 /*FirstQualifierInScope*/ 0, 1662 R, TemplateArgs); 1663} 1664 1665bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1666 const LookupResult &R, 1667 bool HasTrailingLParen) { 1668 // Only when used directly as the postfix-expression of a call. 1669 if (!HasTrailingLParen) 1670 return false; 1671 1672 // Never if a scope specifier was provided. 1673 if (SS.isSet()) 1674 return false; 1675 1676 // Only in C++ or ObjC++. 1677 if (!getLangOptions().CPlusPlus) 1678 return false; 1679 1680 // Turn off ADL when we find certain kinds of declarations during 1681 // normal lookup: 1682 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1683 NamedDecl *D = *I; 1684 1685 // C++0x [basic.lookup.argdep]p3: 1686 // -- a declaration of a class member 1687 // Since using decls preserve this property, we check this on the 1688 // original decl. 1689 if (D->isCXXClassMember()) 1690 return false; 1691 1692 // C++0x [basic.lookup.argdep]p3: 1693 // -- a block-scope function declaration that is not a 1694 // using-declaration 1695 // NOTE: we also trigger this for function templates (in fact, we 1696 // don't check the decl type at all, since all other decl types 1697 // turn off ADL anyway). 1698 if (isa<UsingShadowDecl>(D)) 1699 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1700 else if (D->getDeclContext()->isFunctionOrMethod()) 1701 return false; 1702 1703 // C++0x [basic.lookup.argdep]p3: 1704 // -- a declaration that is neither a function or a function 1705 // template 1706 // And also for builtin functions. 1707 if (isa<FunctionDecl>(D)) { 1708 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1709 1710 // But also builtin functions. 1711 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1712 return false; 1713 } else if (!isa<FunctionTemplateDecl>(D)) 1714 return false; 1715 } 1716 1717 return true; 1718} 1719 1720 1721/// Diagnoses obvious problems with the use of the given declaration 1722/// as an expression. This is only actually called for lookups that 1723/// were not overloaded, and it doesn't promise that the declaration 1724/// will in fact be used. 1725static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1726 if (isa<TypedefDecl>(D)) { 1727 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1728 return true; 1729 } 1730 1731 if (isa<ObjCInterfaceDecl>(D)) { 1732 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1733 return true; 1734 } 1735 1736 if (isa<NamespaceDecl>(D)) { 1737 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1738 return true; 1739 } 1740 1741 return false; 1742} 1743 1744ExprResult 1745Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1746 LookupResult &R, 1747 bool NeedsADL) { 1748 // If this is a single, fully-resolved result and we don't need ADL, 1749 // just build an ordinary singleton decl ref. 1750 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1751 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), 1752 R.getFoundDecl()); 1753 1754 // We only need to check the declaration if there's exactly one 1755 // result, because in the overloaded case the results can only be 1756 // functions and function templates. 1757 if (R.isSingleResult() && 1758 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1759 return ExprError(); 1760 1761 // Otherwise, just build an unresolved lookup expression. Suppress 1762 // any lookup-related diagnostics; we'll hash these out later, when 1763 // we've picked a target. 1764 R.suppressDiagnostics(); 1765 1766 bool Dependent 1767 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1768 UnresolvedLookupExpr *ULE 1769 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1770 (NestedNameSpecifier*) SS.getScopeRep(), 1771 SS.getRange(), R.getLookupNameInfo(), 1772 NeedsADL, R.isOverloadedResult(), 1773 R.begin(), R.end()); 1774 1775 return Owned(ULE); 1776} 1777 1778 1779/// \brief Complete semantic analysis for a reference to the given declaration. 1780ExprResult 1781Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1782 const DeclarationNameInfo &NameInfo, 1783 NamedDecl *D) { 1784 assert(D && "Cannot refer to a NULL declaration"); 1785 assert(!isa<FunctionTemplateDecl>(D) && 1786 "Cannot refer unambiguously to a function template"); 1787 1788 SourceLocation Loc = NameInfo.getLoc(); 1789 if (CheckDeclInExpr(*this, Loc, D)) 1790 return ExprError(); 1791 1792 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1793 // Specifically diagnose references to class templates that are missing 1794 // a template argument list. 1795 Diag(Loc, diag::err_template_decl_ref) 1796 << Template << SS.getRange(); 1797 Diag(Template->getLocation(), diag::note_template_decl_here); 1798 return ExprError(); 1799 } 1800 1801 // Make sure that we're referring to a value. 1802 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1803 if (!VD) { 1804 Diag(Loc, diag::err_ref_non_value) 1805 << D << SS.getRange(); 1806 Diag(D->getLocation(), diag::note_declared_at); 1807 return ExprError(); 1808 } 1809 1810 // Check whether this declaration can be used. Note that we suppress 1811 // this check when we're going to perform argument-dependent lookup 1812 // on this function name, because this might not be the function 1813 // that overload resolution actually selects. 1814 if (DiagnoseUseOfDecl(VD, Loc)) 1815 return ExprError(); 1816 1817 // Only create DeclRefExpr's for valid Decl's. 1818 if (VD->isInvalidDecl()) 1819 return ExprError(); 1820 1821 // If the identifier reference is inside a block, and it refers to a value 1822 // that is outside the block, create a BlockDeclRefExpr instead of a 1823 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1824 // the block is formed. 1825 // 1826 // We do not do this for things like enum constants, global variables, etc, 1827 // as they do not get snapshotted. 1828 // 1829 if (getCurBlock() && 1830 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1831 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1832 Diag(Loc, diag::err_ref_vm_type); 1833 Diag(D->getLocation(), diag::note_declared_at); 1834 return ExprError(); 1835 } 1836 1837 if (VD->getType()->isArrayType()) { 1838 Diag(Loc, diag::err_ref_array_type); 1839 Diag(D->getLocation(), diag::note_declared_at); 1840 return ExprError(); 1841 } 1842 1843 MarkDeclarationReferenced(Loc, VD); 1844 QualType ExprTy = VD->getType().getNonReferenceType(); 1845 // The BlocksAttr indicates the variable is bound by-reference. 1846 if (VD->getAttr<BlocksAttr>()) 1847 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1848 // This is to record that a 'const' was actually synthesize and added. 1849 bool constAdded = !ExprTy.isConstQualified(); 1850 // Variable will be bound by-copy, make it const within the closure. 1851 1852 ExprTy.addConst(); 1853 QualType T = VD->getType(); 1854 BlockDeclRefExpr *BDRE = new (Context) BlockDeclRefExpr(VD, 1855 ExprTy, Loc, false, 1856 constAdded); 1857 if (getLangOptions().CPlusPlus) { 1858 if (!T->isDependentType() && !T->isReferenceType()) { 1859 Expr *E = new (Context) 1860 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 1861 SourceLocation()); 1862 1863 ExprResult Res = PerformCopyInitialization( 1864 InitializedEntity::InitializeBlock(VD->getLocation(), 1865 T, false), 1866 SourceLocation(), 1867 Owned(E)); 1868 if (!Res.isInvalid()) { 1869 Res = MaybeCreateCXXExprWithTemporaries(Res.get()); 1870 Expr *Init = Res.takeAs<Expr>(); 1871 BDRE->setCopyConstructorExpr(Init); 1872 } 1873 } 1874 } 1875 return Owned(BDRE); 1876 } 1877 // If this reference is not in a block or if the referenced variable is 1878 // within the block, create a normal DeclRefExpr. 1879 1880 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), 1881 NameInfo, &SS); 1882} 1883 1884ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1885 tok::TokenKind Kind) { 1886 PredefinedExpr::IdentType IT; 1887 1888 switch (Kind) { 1889 default: assert(0 && "Unknown simple primary expr!"); 1890 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1891 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1892 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1893 } 1894 1895 // Pre-defined identifiers are of type char[x], where x is the length of the 1896 // string. 1897 1898 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1899 if (!currentDecl && getCurBlock()) 1900 currentDecl = getCurBlock()->TheDecl; 1901 if (!currentDecl) { 1902 Diag(Loc, diag::ext_predef_outside_function); 1903 currentDecl = Context.getTranslationUnitDecl(); 1904 } 1905 1906 QualType ResTy; 1907 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1908 ResTy = Context.DependentTy; 1909 } else { 1910 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1911 1912 llvm::APInt LengthI(32, Length + 1); 1913 ResTy = Context.CharTy.withConst(); 1914 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1915 } 1916 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1917} 1918 1919ExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1920 llvm::SmallString<16> CharBuffer; 1921 bool Invalid = false; 1922 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1923 if (Invalid) 1924 return ExprError(); 1925 1926 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1927 PP); 1928 if (Literal.hadError()) 1929 return ExprError(); 1930 1931 QualType Ty; 1932 if (!getLangOptions().CPlusPlus) 1933 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1934 else if (Literal.isWide()) 1935 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1936 else if (Literal.isMultiChar()) 1937 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1938 else 1939 Ty = Context.CharTy; // 'x' -> char in C++ 1940 1941 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1942 Literal.isWide(), 1943 Ty, Tok.getLocation())); 1944} 1945 1946ExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1947 // Fast path for a single digit (which is quite common). A single digit 1948 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1949 if (Tok.getLength() == 1) { 1950 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1951 unsigned IntSize = Context.Target.getIntWidth(); 1952 return Owned(IntegerLiteral::Create(Context, llvm::APInt(IntSize, Val-'0'), 1953 Context.IntTy, Tok.getLocation())); 1954 } 1955 1956 llvm::SmallString<512> IntegerBuffer; 1957 // Add padding so that NumericLiteralParser can overread by one character. 1958 IntegerBuffer.resize(Tok.getLength()+1); 1959 const char *ThisTokBegin = &IntegerBuffer[0]; 1960 1961 // Get the spelling of the token, which eliminates trigraphs, etc. 1962 bool Invalid = false; 1963 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1964 if (Invalid) 1965 return ExprError(); 1966 1967 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1968 Tok.getLocation(), PP); 1969 if (Literal.hadError) 1970 return ExprError(); 1971 1972 Expr *Res; 1973 1974 if (Literal.isFloatingLiteral()) { 1975 QualType Ty; 1976 if (Literal.isFloat) 1977 Ty = Context.FloatTy; 1978 else if (!Literal.isLong) 1979 Ty = Context.DoubleTy; 1980 else 1981 Ty = Context.LongDoubleTy; 1982 1983 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1984 1985 using llvm::APFloat; 1986 APFloat Val(Format); 1987 1988 APFloat::opStatus result = Literal.GetFloatValue(Val); 1989 1990 // Overflow is always an error, but underflow is only an error if 1991 // we underflowed to zero (APFloat reports denormals as underflow). 1992 if ((result & APFloat::opOverflow) || 1993 ((result & APFloat::opUnderflow) && Val.isZero())) { 1994 unsigned diagnostic; 1995 llvm::SmallString<20> buffer; 1996 if (result & APFloat::opOverflow) { 1997 diagnostic = diag::warn_float_overflow; 1998 APFloat::getLargest(Format).toString(buffer); 1999 } else { 2000 diagnostic = diag::warn_float_underflow; 2001 APFloat::getSmallest(Format).toString(buffer); 2002 } 2003 2004 Diag(Tok.getLocation(), diagnostic) 2005 << Ty 2006 << llvm::StringRef(buffer.data(), buffer.size()); 2007 } 2008 2009 bool isExact = (result == APFloat::opOK); 2010 Res = FloatingLiteral::Create(Context, Val, isExact, Ty, Tok.getLocation()); 2011 2012 } else if (!Literal.isIntegerLiteral()) { 2013 return ExprError(); 2014 } else { 2015 QualType Ty; 2016 2017 // long long is a C99 feature. 2018 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 2019 Literal.isLongLong) 2020 Diag(Tok.getLocation(), diag::ext_longlong); 2021 2022 // Get the value in the widest-possible width. 2023 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 2024 2025 if (Literal.GetIntegerValue(ResultVal)) { 2026 // If this value didn't fit into uintmax_t, warn and force to ull. 2027 Diag(Tok.getLocation(), diag::warn_integer_too_large); 2028 Ty = Context.UnsignedLongLongTy; 2029 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 2030 "long long is not intmax_t?"); 2031 } else { 2032 // If this value fits into a ULL, try to figure out what else it fits into 2033 // according to the rules of C99 6.4.4.1p5. 2034 2035 // Octal, Hexadecimal, and integers with a U suffix are allowed to 2036 // be an unsigned int. 2037 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 2038 2039 // Check from smallest to largest, picking the smallest type we can. 2040 unsigned Width = 0; 2041 if (!Literal.isLong && !Literal.isLongLong) { 2042 // Are int/unsigned possibilities? 2043 unsigned IntSize = Context.Target.getIntWidth(); 2044 2045 // Does it fit in a unsigned int? 2046 if (ResultVal.isIntN(IntSize)) { 2047 // Does it fit in a signed int? 2048 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 2049 Ty = Context.IntTy; 2050 else if (AllowUnsigned) 2051 Ty = Context.UnsignedIntTy; 2052 Width = IntSize; 2053 } 2054 } 2055 2056 // Are long/unsigned long possibilities? 2057 if (Ty.isNull() && !Literal.isLongLong) { 2058 unsigned LongSize = Context.Target.getLongWidth(); 2059 2060 // Does it fit in a unsigned long? 2061 if (ResultVal.isIntN(LongSize)) { 2062 // Does it fit in a signed long? 2063 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 2064 Ty = Context.LongTy; 2065 else if (AllowUnsigned) 2066 Ty = Context.UnsignedLongTy; 2067 Width = LongSize; 2068 } 2069 } 2070 2071 // Finally, check long long if needed. 2072 if (Ty.isNull()) { 2073 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2074 2075 // Does it fit in a unsigned long long? 2076 if (ResultVal.isIntN(LongLongSize)) { 2077 // Does it fit in a signed long long? 2078 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 2079 Ty = Context.LongLongTy; 2080 else if (AllowUnsigned) 2081 Ty = Context.UnsignedLongLongTy; 2082 Width = LongLongSize; 2083 } 2084 } 2085 2086 // If we still couldn't decide a type, we probably have something that 2087 // does not fit in a signed long long, but has no U suffix. 2088 if (Ty.isNull()) { 2089 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2090 Ty = Context.UnsignedLongLongTy; 2091 Width = Context.Target.getLongLongWidth(); 2092 } 2093 2094 if (ResultVal.getBitWidth() != Width) 2095 ResultVal.trunc(Width); 2096 } 2097 Res = IntegerLiteral::Create(Context, ResultVal, Ty, Tok.getLocation()); 2098 } 2099 2100 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2101 if (Literal.isImaginary) 2102 Res = new (Context) ImaginaryLiteral(Res, 2103 Context.getComplexType(Res->getType())); 2104 2105 return Owned(Res); 2106} 2107 2108ExprResult Sema::ActOnParenExpr(SourceLocation L, 2109 SourceLocation R, Expr *E) { 2110 assert((E != 0) && "ActOnParenExpr() missing expr"); 2111 return Owned(new (Context) ParenExpr(L, R, E)); 2112} 2113 2114/// The UsualUnaryConversions() function is *not* called by this routine. 2115/// See C99 6.3.2.1p[2-4] for more details. 2116bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2117 SourceLocation OpLoc, 2118 const SourceRange &ExprRange, 2119 bool isSizeof) { 2120 if (exprType->isDependentType()) 2121 return false; 2122 2123 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2124 // the result is the size of the referenced type." 2125 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2126 // result shall be the alignment of the referenced type." 2127 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2128 exprType = Ref->getPointeeType(); 2129 2130 // C99 6.5.3.4p1: 2131 if (exprType->isFunctionType()) { 2132 // alignof(function) is allowed as an extension. 2133 if (isSizeof) 2134 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2135 return false; 2136 } 2137 2138 // Allow sizeof(void)/alignof(void) as an extension. 2139 if (exprType->isVoidType()) { 2140 Diag(OpLoc, diag::ext_sizeof_void_type) 2141 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2142 return false; 2143 } 2144 2145 if (RequireCompleteType(OpLoc, exprType, 2146 PDiag(diag::err_sizeof_alignof_incomplete_type) 2147 << int(!isSizeof) << ExprRange)) 2148 return true; 2149 2150 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2151 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2152 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2153 << exprType << isSizeof << ExprRange; 2154 return true; 2155 } 2156 2157 if (Context.hasSameUnqualifiedType(exprType, Context.OverloadTy)) { 2158 Diag(OpLoc, diag::err_sizeof_alignof_overloaded_function_type) 2159 << !isSizeof << ExprRange; 2160 return true; 2161 } 2162 2163 return false; 2164} 2165 2166bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2167 const SourceRange &ExprRange) { 2168 E = E->IgnoreParens(); 2169 2170 // alignof decl is always ok. 2171 if (isa<DeclRefExpr>(E)) 2172 return false; 2173 2174 // Cannot know anything else if the expression is dependent. 2175 if (E->isTypeDependent()) 2176 return false; 2177 2178 if (E->getBitField()) { 2179 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2180 return true; 2181 } 2182 2183 // Alignment of a field access is always okay, so long as it isn't a 2184 // bit-field. 2185 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2186 if (isa<FieldDecl>(ME->getMemberDecl())) 2187 return false; 2188 2189 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2190} 2191 2192/// \brief Build a sizeof or alignof expression given a type operand. 2193ExprResult 2194Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2195 SourceLocation OpLoc, 2196 bool isSizeOf, SourceRange R) { 2197 if (!TInfo) 2198 return ExprError(); 2199 2200 QualType T = TInfo->getType(); 2201 2202 if (!T->isDependentType() && 2203 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2204 return ExprError(); 2205 2206 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2207 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2208 Context.getSizeType(), OpLoc, 2209 R.getEnd())); 2210} 2211 2212/// \brief Build a sizeof or alignof expression given an expression 2213/// operand. 2214ExprResult 2215Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2216 bool isSizeOf, SourceRange R) { 2217 // Verify that the operand is valid. 2218 bool isInvalid = false; 2219 if (E->isTypeDependent()) { 2220 // Delay type-checking for type-dependent expressions. 2221 } else if (!isSizeOf) { 2222 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2223 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2224 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2225 isInvalid = true; 2226 } else { 2227 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2228 } 2229 2230 if (isInvalid) 2231 return ExprError(); 2232 2233 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2234 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2235 Context.getSizeType(), OpLoc, 2236 R.getEnd())); 2237} 2238 2239/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2240/// the same for @c alignof and @c __alignof 2241/// Note that the ArgRange is invalid if isType is false. 2242ExprResult 2243Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2244 void *TyOrEx, const SourceRange &ArgRange) { 2245 // If error parsing type, ignore. 2246 if (TyOrEx == 0) return ExprError(); 2247 2248 if (isType) { 2249 TypeSourceInfo *TInfo; 2250 (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); 2251 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2252 } 2253 2254 Expr *ArgEx = (Expr *)TyOrEx; 2255 ExprResult Result 2256 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2257 2258 return move(Result); 2259} 2260 2261QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2262 if (V->isTypeDependent()) 2263 return Context.DependentTy; 2264 2265 // These operators return the element type of a complex type. 2266 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2267 return CT->getElementType(); 2268 2269 // Otherwise they pass through real integer and floating point types here. 2270 if (V->getType()->isArithmeticType()) 2271 return V->getType(); 2272 2273 // Reject anything else. 2274 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2275 << (isReal ? "__real" : "__imag"); 2276 return QualType(); 2277} 2278 2279 2280 2281ExprResult 2282Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2283 tok::TokenKind Kind, Expr *Input) { 2284 UnaryOperatorKind Opc; 2285 switch (Kind) { 2286 default: assert(0 && "Unknown unary op!"); 2287 case tok::plusplus: Opc = UO_PostInc; break; 2288 case tok::minusminus: Opc = UO_PostDec; break; 2289 } 2290 2291 return BuildUnaryOp(S, OpLoc, Opc, Input); 2292} 2293 2294ExprResult 2295Sema::ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc, 2296 Expr *Idx, SourceLocation RLoc) { 2297 // Since this might be a postfix expression, get rid of ParenListExprs. 2298 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 2299 if (Result.isInvalid()) return ExprError(); 2300 Base = Result.take(); 2301 2302 Expr *LHSExp = Base, *RHSExp = Idx; 2303 2304 if (getLangOptions().CPlusPlus && 2305 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2306 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2307 Context.DependentTy, RLoc)); 2308 } 2309 2310 if (getLangOptions().CPlusPlus && 2311 (LHSExp->getType()->isRecordType() || 2312 LHSExp->getType()->isEnumeralType() || 2313 RHSExp->getType()->isRecordType() || 2314 RHSExp->getType()->isEnumeralType())) { 2315 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, Base, Idx); 2316 } 2317 2318 return CreateBuiltinArraySubscriptExpr(Base, LLoc, Idx, RLoc); 2319} 2320 2321 2322ExprResult 2323Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, 2324 Expr *Idx, SourceLocation RLoc) { 2325 Expr *LHSExp = Base; 2326 Expr *RHSExp = Idx; 2327 2328 // Perform default conversions. 2329 if (!LHSExp->getType()->getAs<VectorType>()) 2330 DefaultFunctionArrayLvalueConversion(LHSExp); 2331 DefaultFunctionArrayLvalueConversion(RHSExp); 2332 2333 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2334 2335 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2336 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2337 // in the subscript position. As a result, we need to derive the array base 2338 // and index from the expression types. 2339 Expr *BaseExpr, *IndexExpr; 2340 QualType ResultType; 2341 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2342 BaseExpr = LHSExp; 2343 IndexExpr = RHSExp; 2344 ResultType = Context.DependentTy; 2345 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2346 BaseExpr = LHSExp; 2347 IndexExpr = RHSExp; 2348 ResultType = PTy->getPointeeType(); 2349 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2350 // Handle the uncommon case of "123[Ptr]". 2351 BaseExpr = RHSExp; 2352 IndexExpr = LHSExp; 2353 ResultType = PTy->getPointeeType(); 2354 } else if (const ObjCObjectPointerType *PTy = 2355 LHSTy->getAs<ObjCObjectPointerType>()) { 2356 BaseExpr = LHSExp; 2357 IndexExpr = RHSExp; 2358 ResultType = PTy->getPointeeType(); 2359 } else if (const ObjCObjectPointerType *PTy = 2360 RHSTy->getAs<ObjCObjectPointerType>()) { 2361 // Handle the uncommon case of "123[Ptr]". 2362 BaseExpr = RHSExp; 2363 IndexExpr = LHSExp; 2364 ResultType = PTy->getPointeeType(); 2365 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2366 BaseExpr = LHSExp; // vectors: V[123] 2367 IndexExpr = RHSExp; 2368 2369 // FIXME: need to deal with const... 2370 ResultType = VTy->getElementType(); 2371 } else if (LHSTy->isArrayType()) { 2372 // If we see an array that wasn't promoted by 2373 // DefaultFunctionArrayLvalueConversion, it must be an array that 2374 // wasn't promoted because of the C90 rule that doesn't 2375 // allow promoting non-lvalue arrays. Warn, then 2376 // force the promotion here. 2377 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2378 LHSExp->getSourceRange(); 2379 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2380 CK_ArrayToPointerDecay); 2381 LHSTy = LHSExp->getType(); 2382 2383 BaseExpr = LHSExp; 2384 IndexExpr = RHSExp; 2385 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2386 } else if (RHSTy->isArrayType()) { 2387 // Same as previous, except for 123[f().a] case 2388 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2389 RHSExp->getSourceRange(); 2390 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2391 CK_ArrayToPointerDecay); 2392 RHSTy = RHSExp->getType(); 2393 2394 BaseExpr = RHSExp; 2395 IndexExpr = LHSExp; 2396 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2397 } else { 2398 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2399 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2400 } 2401 // C99 6.5.2.1p1 2402 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) 2403 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2404 << IndexExpr->getSourceRange()); 2405 2406 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2407 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2408 && !IndexExpr->isTypeDependent()) 2409 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2410 2411 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2412 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2413 // type. Note that Functions are not objects, and that (in C99 parlance) 2414 // incomplete types are not object types. 2415 if (ResultType->isFunctionType()) { 2416 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2417 << ResultType << BaseExpr->getSourceRange(); 2418 return ExprError(); 2419 } 2420 2421 if (ResultType->isVoidType() && !getLangOptions().CPlusPlus) { 2422 // GNU extension: subscripting on pointer to void 2423 Diag(LLoc, diag::ext_gnu_void_ptr) 2424 << BaseExpr->getSourceRange(); 2425 } else if (!ResultType->isDependentType() && 2426 RequireCompleteType(LLoc, ResultType, 2427 PDiag(diag::err_subscript_incomplete_type) 2428 << BaseExpr->getSourceRange())) 2429 return ExprError(); 2430 2431 // Diagnose bad cases where we step over interface counts. 2432 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2433 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2434 << ResultType << BaseExpr->getSourceRange(); 2435 return ExprError(); 2436 } 2437 2438 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2439 ResultType, RLoc)); 2440} 2441 2442QualType Sema:: 2443CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2444 const IdentifierInfo *CompName, 2445 SourceLocation CompLoc) { 2446 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2447 // see FIXME there. 2448 // 2449 // FIXME: This logic can be greatly simplified by splitting it along 2450 // halving/not halving and reworking the component checking. 2451 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2452 2453 // The vector accessor can't exceed the number of elements. 2454 const char *compStr = CompName->getNameStart(); 2455 2456 // This flag determines whether or not the component is one of the four 2457 // special names that indicate a subset of exactly half the elements are 2458 // to be selected. 2459 bool HalvingSwizzle = false; 2460 2461 // This flag determines whether or not CompName has an 's' char prefix, 2462 // indicating that it is a string of hex values to be used as vector indices. 2463 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2464 2465 // Check that we've found one of the special components, or that the component 2466 // names must come from the same set. 2467 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2468 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2469 HalvingSwizzle = true; 2470 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2471 do 2472 compStr++; 2473 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2474 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2475 do 2476 compStr++; 2477 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2478 } 2479 2480 if (!HalvingSwizzle && *compStr) { 2481 // We didn't get to the end of the string. This means the component names 2482 // didn't come from the same set *or* we encountered an illegal name. 2483 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2484 << llvm::StringRef(compStr, 1) << SourceRange(CompLoc); 2485 return QualType(); 2486 } 2487 2488 // Ensure no component accessor exceeds the width of the vector type it 2489 // operates on. 2490 if (!HalvingSwizzle) { 2491 compStr = CompName->getNameStart(); 2492 2493 if (HexSwizzle) 2494 compStr++; 2495 2496 while (*compStr) { 2497 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2498 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2499 << baseType << SourceRange(CompLoc); 2500 return QualType(); 2501 } 2502 } 2503 } 2504 2505 // The component accessor looks fine - now we need to compute the actual type. 2506 // The vector type is implied by the component accessor. For example, 2507 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2508 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2509 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2510 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2511 : CompName->getLength(); 2512 if (HexSwizzle) 2513 CompSize--; 2514 2515 if (CompSize == 1) 2516 return vecType->getElementType(); 2517 2518 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2519 // Now look up the TypeDefDecl from the vector type. Without this, 2520 // diagostics look bad. We want extended vector types to appear built-in. 2521 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2522 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2523 return Context.getTypedefType(ExtVectorDecls[i]); 2524 } 2525 return VT; // should never get here (a typedef type should always be found). 2526} 2527 2528static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2529 IdentifierInfo *Member, 2530 const Selector &Sel, 2531 ASTContext &Context) { 2532 2533 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2534 return PD; 2535 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2536 return OMD; 2537 2538 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2539 E = PDecl->protocol_end(); I != E; ++I) { 2540 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2541 Context)) 2542 return D; 2543 } 2544 return 0; 2545} 2546 2547static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2548 IdentifierInfo *Member, 2549 const Selector &Sel, 2550 ASTContext &Context) { 2551 // Check protocols on qualified interfaces. 2552 Decl *GDecl = 0; 2553 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2554 E = QIdTy->qual_end(); I != E; ++I) { 2555 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2556 GDecl = PD; 2557 break; 2558 } 2559 // Also must look for a getter name which uses property syntax. 2560 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2561 GDecl = OMD; 2562 break; 2563 } 2564 } 2565 if (!GDecl) { 2566 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2567 E = QIdTy->qual_end(); I != E; ++I) { 2568 // Search in the protocol-qualifier list of current protocol. 2569 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2570 if (GDecl) 2571 return GDecl; 2572 } 2573 } 2574 return GDecl; 2575} 2576 2577ExprResult 2578Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, 2579 bool IsArrow, SourceLocation OpLoc, 2580 const CXXScopeSpec &SS, 2581 NamedDecl *FirstQualifierInScope, 2582 const DeclarationNameInfo &NameInfo, 2583 const TemplateArgumentListInfo *TemplateArgs) { 2584 // Even in dependent contexts, try to diagnose base expressions with 2585 // obviously wrong types, e.g.: 2586 // 2587 // T* t; 2588 // t.f; 2589 // 2590 // In Obj-C++, however, the above expression is valid, since it could be 2591 // accessing the 'f' property if T is an Obj-C interface. The extra check 2592 // allows this, while still reporting an error if T is a struct pointer. 2593 if (!IsArrow) { 2594 const PointerType *PT = BaseType->getAs<PointerType>(); 2595 if (PT && (!getLangOptions().ObjC1 || 2596 PT->getPointeeType()->isRecordType())) { 2597 assert(BaseExpr && "cannot happen with implicit member accesses"); 2598 Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) 2599 << BaseType << BaseExpr->getSourceRange(); 2600 return ExprError(); 2601 } 2602 } 2603 2604 assert(BaseType->isDependentType() || 2605 NameInfo.getName().isDependentName() || 2606 isDependentScopeSpecifier(SS)); 2607 2608 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2609 // must have pointer type, and the accessed type is the pointee. 2610 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2611 IsArrow, OpLoc, 2612 SS.getScopeRep(), 2613 SS.getRange(), 2614 FirstQualifierInScope, 2615 NameInfo, TemplateArgs)); 2616} 2617 2618/// We know that the given qualified member reference points only to 2619/// declarations which do not belong to the static type of the base 2620/// expression. Diagnose the problem. 2621static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2622 Expr *BaseExpr, 2623 QualType BaseType, 2624 const CXXScopeSpec &SS, 2625 const LookupResult &R) { 2626 // If this is an implicit member access, use a different set of 2627 // diagnostics. 2628 if (!BaseExpr) 2629 return DiagnoseInstanceReference(SemaRef, SS, R); 2630 2631 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 2632 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 2633} 2634 2635// Check whether the declarations we found through a nested-name 2636// specifier in a member expression are actually members of the base 2637// type. The restriction here is: 2638// 2639// C++ [expr.ref]p2: 2640// ... In these cases, the id-expression shall name a 2641// member of the class or of one of its base classes. 2642// 2643// So it's perfectly legitimate for the nested-name specifier to name 2644// an unrelated class, and for us to find an overload set including 2645// decls from classes which are not superclasses, as long as the decl 2646// we actually pick through overload resolution is from a superclass. 2647bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2648 QualType BaseType, 2649 const CXXScopeSpec &SS, 2650 const LookupResult &R) { 2651 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2652 if (!BaseRT) { 2653 // We can't check this yet because the base type is still 2654 // dependent. 2655 assert(BaseType->isDependentType()); 2656 return false; 2657 } 2658 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2659 2660 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2661 // If this is an implicit member reference and we find a 2662 // non-instance member, it's not an error. 2663 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2664 return false; 2665 2666 // Note that we use the DC of the decl, not the underlying decl. 2667 DeclContext *DC = (*I)->getDeclContext(); 2668 while (DC->isTransparentContext()) 2669 DC = DC->getParent(); 2670 2671 if (!DC->isRecord()) 2672 continue; 2673 2674 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2675 MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); 2676 2677 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2678 return false; 2679 } 2680 2681 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2682 return true; 2683} 2684 2685static bool 2686LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2687 SourceRange BaseRange, const RecordType *RTy, 2688 SourceLocation OpLoc, CXXScopeSpec &SS, 2689 bool HasTemplateArgs) { 2690 RecordDecl *RDecl = RTy->getDecl(); 2691 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2692 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2693 << BaseRange)) 2694 return true; 2695 2696 if (HasTemplateArgs) { 2697 // LookupTemplateName doesn't expect these both to exist simultaneously. 2698 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 2699 2700 bool MOUS; 2701 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 2702 return false; 2703 } 2704 2705 DeclContext *DC = RDecl; 2706 if (SS.isSet()) { 2707 // If the member name was a qualified-id, look into the 2708 // nested-name-specifier. 2709 DC = SemaRef.computeDeclContext(SS, false); 2710 2711 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 2712 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2713 << SS.getRange() << DC; 2714 return true; 2715 } 2716 2717 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2718 2719 if (!isa<TypeDecl>(DC)) { 2720 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2721 << DC << SS.getRange(); 2722 return true; 2723 } 2724 } 2725 2726 // The record definition is complete, now look up the member. 2727 SemaRef.LookupQualifiedName(R, DC); 2728 2729 if (!R.empty()) 2730 return false; 2731 2732 // We didn't find anything with the given name, so try to correct 2733 // for typos. 2734 DeclarationName Name = R.getLookupName(); 2735 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 2736 !R.empty() && 2737 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2738 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2739 << Name << DC << R.getLookupName() << SS.getRange() 2740 << FixItHint::CreateReplacement(R.getNameLoc(), 2741 R.getLookupName().getAsString()); 2742 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2743 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2744 << ND->getDeclName(); 2745 return false; 2746 } else { 2747 R.clear(); 2748 R.setLookupName(Name); 2749 } 2750 2751 return false; 2752} 2753 2754ExprResult 2755Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, 2756 SourceLocation OpLoc, bool IsArrow, 2757 CXXScopeSpec &SS, 2758 NamedDecl *FirstQualifierInScope, 2759 const DeclarationNameInfo &NameInfo, 2760 const TemplateArgumentListInfo *TemplateArgs) { 2761 if (BaseType->isDependentType() || 2762 (SS.isSet() && isDependentScopeSpecifier(SS))) 2763 return ActOnDependentMemberExpr(Base, BaseType, 2764 IsArrow, OpLoc, 2765 SS, FirstQualifierInScope, 2766 NameInfo, TemplateArgs); 2767 2768 LookupResult R(*this, NameInfo, LookupMemberName); 2769 2770 // Implicit member accesses. 2771 if (!Base) { 2772 QualType RecordTy = BaseType; 2773 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2774 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2775 RecordTy->getAs<RecordType>(), 2776 OpLoc, SS, TemplateArgs != 0)) 2777 return ExprError(); 2778 2779 // Explicit member accesses. 2780 } else { 2781 ExprResult Result = 2782 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2783 SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); 2784 2785 if (Result.isInvalid()) { 2786 Owned(Base); 2787 return ExprError(); 2788 } 2789 2790 if (Result.get()) 2791 return move(Result); 2792 2793 // LookupMemberExpr can modify Base, and thus change BaseType 2794 BaseType = Base->getType(); 2795 } 2796 2797 return BuildMemberReferenceExpr(Base, BaseType, 2798 OpLoc, IsArrow, SS, FirstQualifierInScope, 2799 R, TemplateArgs); 2800} 2801 2802ExprResult 2803Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, 2804 SourceLocation OpLoc, bool IsArrow, 2805 const CXXScopeSpec &SS, 2806 NamedDecl *FirstQualifierInScope, 2807 LookupResult &R, 2808 const TemplateArgumentListInfo *TemplateArgs, 2809 bool SuppressQualifierCheck) { 2810 QualType BaseType = BaseExprType; 2811 if (IsArrow) { 2812 assert(BaseType->isPointerType()); 2813 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2814 } 2815 R.setBaseObjectType(BaseType); 2816 2817 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 2818 const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); 2819 DeclarationName MemberName = MemberNameInfo.getName(); 2820 SourceLocation MemberLoc = MemberNameInfo.getLoc(); 2821 2822 if (R.isAmbiguous()) 2823 return ExprError(); 2824 2825 if (R.empty()) { 2826 // Rederive where we looked up. 2827 DeclContext *DC = (SS.isSet() 2828 ? computeDeclContext(SS, false) 2829 : BaseType->getAs<RecordType>()->getDecl()); 2830 2831 Diag(R.getNameLoc(), diag::err_no_member) 2832 << MemberName << DC 2833 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2834 return ExprError(); 2835 } 2836 2837 // Diagnose lookups that find only declarations from a non-base 2838 // type. This is possible for either qualified lookups (which may 2839 // have been qualified with an unrelated type) or implicit member 2840 // expressions (which were found with unqualified lookup and thus 2841 // may have come from an enclosing scope). Note that it's okay for 2842 // lookup to find declarations from a non-base type as long as those 2843 // aren't the ones picked by overload resolution. 2844 if ((SS.isSet() || !BaseExpr || 2845 (isa<CXXThisExpr>(BaseExpr) && 2846 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2847 !SuppressQualifierCheck && 2848 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2849 return ExprError(); 2850 2851 // Construct an unresolved result if we in fact got an unresolved 2852 // result. 2853 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2854 bool Dependent = 2855 BaseExprType->isDependentType() || 2856 R.isUnresolvableResult() || 2857 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2858 2859 // Suppress any lookup-related diagnostics; we'll do these when we 2860 // pick a member. 2861 R.suppressDiagnostics(); 2862 2863 UnresolvedMemberExpr *MemExpr 2864 = UnresolvedMemberExpr::Create(Context, Dependent, 2865 R.isUnresolvableResult(), 2866 BaseExpr, BaseExprType, 2867 IsArrow, OpLoc, 2868 Qualifier, SS.getRange(), 2869 MemberNameInfo, 2870 TemplateArgs, R.begin(), R.end()); 2871 2872 return Owned(MemExpr); 2873 } 2874 2875 assert(R.isSingleResult()); 2876 DeclAccessPair FoundDecl = R.begin().getPair(); 2877 NamedDecl *MemberDecl = R.getFoundDecl(); 2878 2879 // FIXME: diagnose the presence of template arguments now. 2880 2881 // If the decl being referenced had an error, return an error for this 2882 // sub-expr without emitting another error, in order to avoid cascading 2883 // error cases. 2884 if (MemberDecl->isInvalidDecl()) 2885 return ExprError(); 2886 2887 // Handle the implicit-member-access case. 2888 if (!BaseExpr) { 2889 // If this is not an instance member, convert to a non-member access. 2890 if (!MemberDecl->isCXXInstanceMember()) 2891 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); 2892 2893 SourceLocation Loc = R.getNameLoc(); 2894 if (SS.getRange().isValid()) 2895 Loc = SS.getRange().getBegin(); 2896 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2897 } 2898 2899 bool ShouldCheckUse = true; 2900 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2901 // Don't diagnose the use of a virtual member function unless it's 2902 // explicitly qualified. 2903 if (MD->isVirtual() && !SS.isSet()) 2904 ShouldCheckUse = false; 2905 } 2906 2907 // Check the use of this member. 2908 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2909 Owned(BaseExpr); 2910 return ExprError(); 2911 } 2912 2913 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2914 // We may have found a field within an anonymous union or struct 2915 // (C++ [class.union]). 2916 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2917 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2918 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2919 BaseExpr, OpLoc); 2920 2921 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2922 QualType MemberType = FD->getType(); 2923 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2924 MemberType = Ref->getPointeeType(); 2925 else { 2926 Qualifiers BaseQuals = BaseType.getQualifiers(); 2927 BaseQuals.removeObjCGCAttr(); 2928 if (FD->isMutable()) BaseQuals.removeConst(); 2929 2930 Qualifiers MemberQuals 2931 = Context.getCanonicalType(MemberType).getQualifiers(); 2932 2933 Qualifiers Combined = BaseQuals + MemberQuals; 2934 if (Combined != MemberQuals) 2935 MemberType = Context.getQualifiedType(MemberType, Combined); 2936 } 2937 2938 MarkDeclarationReferenced(MemberLoc, FD); 2939 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2940 return ExprError(); 2941 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2942 FD, FoundDecl, MemberNameInfo, 2943 MemberType)); 2944 } 2945 2946 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2947 MarkDeclarationReferenced(MemberLoc, Var); 2948 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2949 Var, FoundDecl, MemberNameInfo, 2950 Var->getType().getNonReferenceType())); 2951 } 2952 2953 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2954 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2955 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2956 MemberFn, FoundDecl, MemberNameInfo, 2957 MemberFn->getType())); 2958 } 2959 2960 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2961 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2962 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2963 Enum, FoundDecl, MemberNameInfo, 2964 Enum->getType())); 2965 } 2966 2967 Owned(BaseExpr); 2968 2969 // We found something that we didn't expect. Complain. 2970 if (isa<TypeDecl>(MemberDecl)) 2971 Diag(MemberLoc, diag::err_typecheck_member_reference_type) 2972 << MemberName << BaseType << int(IsArrow); 2973 else 2974 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 2975 << MemberName << BaseType << int(IsArrow); 2976 2977 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 2978 << MemberName; 2979 R.suppressDiagnostics(); 2980 return ExprError(); 2981} 2982 2983/// Look up the given member of the given non-type-dependent 2984/// expression. This can return in one of two ways: 2985/// * If it returns a sentinel null-but-valid result, the caller will 2986/// assume that lookup was performed and the results written into 2987/// the provided structure. It will take over from there. 2988/// * Otherwise, the returned expression will be produced in place of 2989/// an ordinary member expression. 2990/// 2991/// The ObjCImpDecl bit is a gross hack that will need to be properly 2992/// fixed for ObjC++. 2993ExprResult 2994Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2995 bool &IsArrow, SourceLocation OpLoc, 2996 CXXScopeSpec &SS, 2997 Decl *ObjCImpDecl, bool HasTemplateArgs) { 2998 assert(BaseExpr && "no base expression"); 2999 3000 // Perform default conversions. 3001 DefaultFunctionArrayConversion(BaseExpr); 3002 3003 QualType BaseType = BaseExpr->getType(); 3004 assert(!BaseType->isDependentType()); 3005 3006 DeclarationName MemberName = R.getLookupName(); 3007 SourceLocation MemberLoc = R.getNameLoc(); 3008 3009 // If the user is trying to apply -> or . to a function pointer 3010 // type, it's probably because they forgot parentheses to call that 3011 // function. Suggest the addition of those parentheses, build the 3012 // call, and continue on. 3013 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 3014 if (const FunctionProtoType *Fun 3015 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 3016 QualType ResultTy = Fun->getResultType(); 3017 if (Fun->getNumArgs() == 0 && 3018 ((!IsArrow && ResultTy->isRecordType()) || 3019 (IsArrow && ResultTy->isPointerType() && 3020 ResultTy->getAs<PointerType>()->getPointeeType() 3021 ->isRecordType()))) { 3022 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 3023 Diag(Loc, diag::err_member_reference_needs_call) 3024 << QualType(Fun, 0) 3025 << FixItHint::CreateInsertion(Loc, "()"); 3026 3027 ExprResult NewBase 3028 = ActOnCallExpr(0, BaseExpr, Loc, MultiExprArg(*this, 0, 0), Loc); 3029 BaseExpr = 0; 3030 if (NewBase.isInvalid()) 3031 return ExprError(); 3032 3033 BaseExpr = NewBase.takeAs<Expr>(); 3034 DefaultFunctionArrayConversion(BaseExpr); 3035 BaseType = BaseExpr->getType(); 3036 } 3037 } 3038 } 3039 3040 // If this is an Objective-C pseudo-builtin and a definition is provided then 3041 // use that. 3042 if (BaseType->isObjCIdType()) { 3043 if (IsArrow) { 3044 // Handle the following exceptional case PObj->isa. 3045 if (const ObjCObjectPointerType *OPT = 3046 BaseType->getAs<ObjCObjectPointerType>()) { 3047 if (OPT->getObjectType()->isObjCId() && 3048 MemberName.getAsIdentifierInfo()->isStr("isa")) 3049 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 3050 Context.getObjCClassType())); 3051 } 3052 } 3053 // We have an 'id' type. Rather than fall through, we check if this 3054 // is a reference to 'isa'. 3055 if (BaseType != Context.ObjCIdRedefinitionType) { 3056 BaseType = Context.ObjCIdRedefinitionType; 3057 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3058 } 3059 } 3060 3061 // If this is an Objective-C pseudo-builtin and a definition is provided then 3062 // use that. 3063 if (Context.isObjCSelType(BaseType)) { 3064 // We have an 'SEL' type. Rather than fall through, we check if this 3065 // is a reference to 'sel_id'. 3066 if (BaseType != Context.ObjCSelRedefinitionType) { 3067 BaseType = Context.ObjCSelRedefinitionType; 3068 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3069 } 3070 } 3071 3072 assert(!BaseType.isNull() && "no type for member expression"); 3073 3074 // Handle properties on ObjC 'Class' types. 3075 if (!IsArrow && BaseType->isObjCClassType()) { 3076 // Also must look for a getter name which uses property syntax. 3077 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3078 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3079 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 3080 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3081 ObjCMethodDecl *Getter; 3082 // FIXME: need to also look locally in the implementation. 3083 if ((Getter = IFace->lookupClassMethod(Sel))) { 3084 // Check the use of this method. 3085 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3086 return ExprError(); 3087 } 3088 // If we found a getter then this may be a valid dot-reference, we 3089 // will look for the matching setter, in case it is needed. 3090 Selector SetterSel = 3091 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3092 PP.getSelectorTable(), Member); 3093 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3094 if (!Setter) { 3095 // If this reference is in an @implementation, also check for 'private' 3096 // methods. 3097 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3098 } 3099 // Look through local category implementations associated with the class. 3100 if (!Setter) 3101 Setter = IFace->getCategoryClassMethod(SetterSel); 3102 3103 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3104 return ExprError(); 3105 3106 if (Getter || Setter) { 3107 QualType PType; 3108 3109 if (Getter) 3110 PType = Getter->getSendResultType(); 3111 else 3112 // Get the expression type from Setter's incoming parameter. 3113 PType = (*(Setter->param_end() -1))->getType(); 3114 // FIXME: we must check that the setter has property type. 3115 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 3116 PType, 3117 Setter, MemberLoc, BaseExpr)); 3118 } 3119 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3120 << MemberName << BaseType); 3121 } 3122 } 3123 3124 if (BaseType->isObjCClassType() && 3125 BaseType != Context.ObjCClassRedefinitionType) { 3126 BaseType = Context.ObjCClassRedefinitionType; 3127 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3128 } 3129 3130 if (IsArrow) { 3131 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3132 BaseType = PT->getPointeeType(); 3133 else if (BaseType->isObjCObjectPointerType()) 3134 ; 3135 else if (BaseType->isRecordType()) { 3136 // Recover from arrow accesses to records, e.g.: 3137 // struct MyRecord foo; 3138 // foo->bar 3139 // This is actually well-formed in C++ if MyRecord has an 3140 // overloaded operator->, but that should have been dealt with 3141 // by now. 3142 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3143 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3144 << FixItHint::CreateReplacement(OpLoc, "."); 3145 IsArrow = false; 3146 } else { 3147 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3148 << BaseType << BaseExpr->getSourceRange(); 3149 return ExprError(); 3150 } 3151 } else { 3152 // Recover from dot accesses to pointers, e.g.: 3153 // type *foo; 3154 // foo.bar 3155 // This is actually well-formed in two cases: 3156 // - 'type' is an Objective C type 3157 // - 'bar' is a pseudo-destructor name which happens to refer to 3158 // the appropriate pointer type 3159 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3160 const PointerType *PT = BaseType->getAs<PointerType>(); 3161 if (PT && PT->getPointeeType()->isRecordType()) { 3162 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3163 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3164 << FixItHint::CreateReplacement(OpLoc, "->"); 3165 BaseType = PT->getPointeeType(); 3166 IsArrow = true; 3167 } 3168 } 3169 } 3170 3171 // Handle field access to simple records. 3172 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3173 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3174 RTy, OpLoc, SS, HasTemplateArgs)) 3175 return ExprError(); 3176 return Owned((Expr*) 0); 3177 } 3178 3179 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3180 // (*Obj).ivar. 3181 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3182 (!IsArrow && BaseType->isObjCObjectType())) { 3183 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3184 ObjCInterfaceDecl *IDecl = 3185 OPT ? OPT->getInterfaceDecl() 3186 : BaseType->getAs<ObjCObjectType>()->getInterface(); 3187 if (IDecl) { 3188 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3189 3190 ObjCInterfaceDecl *ClassDeclared; 3191 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3192 3193 if (!IV) { 3194 // Attempt to correct for typos in ivar names. 3195 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3196 LookupMemberName); 3197 if (CorrectTypo(Res, 0, 0, IDecl, false, CTC_MemberLookup) && 3198 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3199 Diag(R.getNameLoc(), 3200 diag::err_typecheck_member_reference_ivar_suggest) 3201 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3202 << FixItHint::CreateReplacement(R.getNameLoc(), 3203 IV->getNameAsString()); 3204 Diag(IV->getLocation(), diag::note_previous_decl) 3205 << IV->getDeclName(); 3206 } else { 3207 Res.clear(); 3208 Res.setLookupName(Member); 3209 } 3210 } 3211 3212 if (IV) { 3213 // If the decl being referenced had an error, return an error for this 3214 // sub-expr without emitting another error, in order to avoid cascading 3215 // error cases. 3216 if (IV->isInvalidDecl()) 3217 return ExprError(); 3218 3219 // Check whether we can reference this field. 3220 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3221 return ExprError(); 3222 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3223 IV->getAccessControl() != ObjCIvarDecl::Package) { 3224 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3225 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3226 ClassOfMethodDecl = MD->getClassInterface(); 3227 else if (ObjCImpDecl && getCurFunctionDecl()) { 3228 // Case of a c-function declared inside an objc implementation. 3229 // FIXME: For a c-style function nested inside an objc implementation 3230 // class, there is no implementation context available, so we pass 3231 // down the context as argument to this routine. Ideally, this context 3232 // need be passed down in the AST node and somehow calculated from the 3233 // AST for a function decl. 3234 if (ObjCImplementationDecl *IMPD = 3235 dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) 3236 ClassOfMethodDecl = IMPD->getClassInterface(); 3237 else if (ObjCCategoryImplDecl* CatImplClass = 3238 dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) 3239 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3240 } 3241 3242 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3243 if (ClassDeclared != IDecl || 3244 ClassOfMethodDecl != ClassDeclared) 3245 Diag(MemberLoc, diag::error_private_ivar_access) 3246 << IV->getDeclName(); 3247 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3248 // @protected 3249 Diag(MemberLoc, diag::error_protected_ivar_access) 3250 << IV->getDeclName(); 3251 } 3252 3253 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3254 MemberLoc, BaseExpr, 3255 IsArrow)); 3256 } 3257 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3258 << IDecl->getDeclName() << MemberName 3259 << BaseExpr->getSourceRange()); 3260 } 3261 } 3262 // Handle properties on 'id' and qualified "id". 3263 if (!IsArrow && (BaseType->isObjCIdType() || 3264 BaseType->isObjCQualifiedIdType())) { 3265 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3266 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3267 3268 // Check protocols on qualified interfaces. 3269 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3270 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3271 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3272 // Check the use of this declaration 3273 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3274 return ExprError(); 3275 3276 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3277 MemberLoc, BaseExpr)); 3278 } 3279 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3280 // Check the use of this method. 3281 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3282 return ExprError(); 3283 3284 return Owned(ObjCMessageExpr::Create(Context, 3285 OMD->getSendResultType(), 3286 OpLoc, BaseExpr, Sel, 3287 OMD, NULL, 0, MemberLoc)); 3288 } 3289 } 3290 3291 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3292 << MemberName << BaseType); 3293 } 3294 3295 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3296 // pointer to a (potentially qualified) interface type. 3297 if (!IsArrow) 3298 if (const ObjCObjectPointerType *OPT = 3299 BaseType->getAsObjCInterfacePointerType()) 3300 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc); 3301 3302 // Handle the following exceptional case (*Obj).isa. 3303 if (!IsArrow && 3304 BaseType->isObjCObjectType() && 3305 BaseType->getAs<ObjCObjectType>()->isObjCId() && 3306 MemberName.getAsIdentifierInfo()->isStr("isa")) 3307 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3308 Context.getObjCClassType())); 3309 3310 // Handle 'field access' to vectors, such as 'V.xx'. 3311 if (BaseType->isExtVectorType()) { 3312 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3313 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3314 if (ret.isNull()) 3315 return ExprError(); 3316 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3317 MemberLoc)); 3318 } 3319 3320 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3321 << BaseType << BaseExpr->getSourceRange(); 3322 3323 return ExprError(); 3324} 3325 3326/// The main callback when the parser finds something like 3327/// expression . [nested-name-specifier] identifier 3328/// expression -> [nested-name-specifier] identifier 3329/// where 'identifier' encompasses a fairly broad spectrum of 3330/// possibilities, including destructor and operator references. 3331/// 3332/// \param OpKind either tok::arrow or tok::period 3333/// \param HasTrailingLParen whether the next token is '(', which 3334/// is used to diagnose mis-uses of special members that can 3335/// only be called 3336/// \param ObjCImpDecl the current ObjC @implementation decl; 3337/// this is an ugly hack around the fact that ObjC @implementations 3338/// aren't properly put in the context chain 3339ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, 3340 SourceLocation OpLoc, 3341 tok::TokenKind OpKind, 3342 CXXScopeSpec &SS, 3343 UnqualifiedId &Id, 3344 Decl *ObjCImpDecl, 3345 bool HasTrailingLParen) { 3346 if (SS.isSet() && SS.isInvalid()) 3347 return ExprError(); 3348 3349 TemplateArgumentListInfo TemplateArgsBuffer; 3350 3351 // Decompose the name into its component parts. 3352 DeclarationNameInfo NameInfo; 3353 const TemplateArgumentListInfo *TemplateArgs; 3354 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3355 NameInfo, TemplateArgs); 3356 3357 DeclarationName Name = NameInfo.getName(); 3358 bool IsArrow = (OpKind == tok::arrow); 3359 3360 NamedDecl *FirstQualifierInScope 3361 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3362 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3363 3364 // This is a postfix expression, so get rid of ParenListExprs. 3365 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 3366 if (Result.isInvalid()) return ExprError(); 3367 Base = Result.take(); 3368 3369 if (Base->getType()->isDependentType() || Name.isDependentName() || 3370 isDependentScopeSpecifier(SS)) { 3371 Result = ActOnDependentMemberExpr(Base, Base->getType(), 3372 IsArrow, OpLoc, 3373 SS, FirstQualifierInScope, 3374 NameInfo, TemplateArgs); 3375 } else { 3376 LookupResult R(*this, NameInfo, LookupMemberName); 3377 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3378 SS, ObjCImpDecl, TemplateArgs != 0); 3379 3380 if (Result.isInvalid()) { 3381 Owned(Base); 3382 return ExprError(); 3383 } 3384 3385 if (Result.get()) { 3386 // The only way a reference to a destructor can be used is to 3387 // immediately call it, which falls into this case. If the 3388 // next token is not a '(', produce a diagnostic and build the 3389 // call now. 3390 if (!HasTrailingLParen && 3391 Id.getKind() == UnqualifiedId::IK_DestructorName) 3392 return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); 3393 3394 return move(Result); 3395 } 3396 3397 Result = BuildMemberReferenceExpr(Base, Base->getType(), 3398 OpLoc, IsArrow, SS, FirstQualifierInScope, 3399 R, TemplateArgs); 3400 } 3401 3402 return move(Result); 3403} 3404 3405ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3406 FunctionDecl *FD, 3407 ParmVarDecl *Param) { 3408 if (Param->hasUnparsedDefaultArg()) { 3409 Diag(CallLoc, 3410 diag::err_use_of_default_argument_to_function_declared_later) << 3411 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3412 Diag(UnparsedDefaultArgLocs[Param], 3413 diag::note_default_argument_declared_here); 3414 return ExprError(); 3415 } 3416 3417 if (Param->hasUninstantiatedDefaultArg()) { 3418 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3419 3420 // Instantiate the expression. 3421 MultiLevelTemplateArgumentList ArgList 3422 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3423 3424 std::pair<const TemplateArgument *, unsigned> Innermost 3425 = ArgList.getInnermost(); 3426 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3427 Innermost.second); 3428 3429 ExprResult Result = SubstExpr(UninstExpr, ArgList); 3430 if (Result.isInvalid()) 3431 return ExprError(); 3432 3433 // Check the expression as an initializer for the parameter. 3434 InitializedEntity Entity 3435 = InitializedEntity::InitializeParameter(Param); 3436 InitializationKind Kind 3437 = InitializationKind::CreateCopy(Param->getLocation(), 3438 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3439 Expr *ResultE = Result.takeAs<Expr>(); 3440 3441 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3442 Result = InitSeq.Perform(*this, Entity, Kind, 3443 MultiExprArg(*this, &ResultE, 1)); 3444 if (Result.isInvalid()) 3445 return ExprError(); 3446 3447 // Build the default argument expression. 3448 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3449 Result.takeAs<Expr>())); 3450 } 3451 3452 // If the default expression creates temporaries, we need to 3453 // push them to the current stack of expression temporaries so they'll 3454 // be properly destroyed. 3455 // FIXME: We should really be rebuilding the default argument with new 3456 // bound temporaries; see the comment in PR5810. 3457 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) { 3458 CXXTemporary *Temporary = Param->getDefaultArgTemporary(i); 3459 MarkDeclarationReferenced(Param->getDefaultArg()->getLocStart(), 3460 const_cast<CXXDestructorDecl*>(Temporary->getDestructor())); 3461 ExprTemporaries.push_back(Temporary); 3462 } 3463 3464 // We already type-checked the argument, so we know it works. 3465 // Just mark all of the declarations in this potentially-evaluated expression 3466 // as being "referenced". 3467 MarkDeclarationsReferencedInExpr(Param->getDefaultArg()); 3468 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3469} 3470 3471/// ConvertArgumentsForCall - Converts the arguments specified in 3472/// Args/NumArgs to the parameter types of the function FDecl with 3473/// function prototype Proto. Call is the call expression itself, and 3474/// Fn is the function expression. For a C++ member function, this 3475/// routine does not attempt to convert the object argument. Returns 3476/// true if the call is ill-formed. 3477bool 3478Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3479 FunctionDecl *FDecl, 3480 const FunctionProtoType *Proto, 3481 Expr **Args, unsigned NumArgs, 3482 SourceLocation RParenLoc) { 3483 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3484 // assignment, to the types of the corresponding parameter, ... 3485 unsigned NumArgsInProto = Proto->getNumArgs(); 3486 bool Invalid = false; 3487 3488 // If too few arguments are available (and we don't have default 3489 // arguments for the remaining parameters), don't make the call. 3490 if (NumArgs < NumArgsInProto) { 3491 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3492 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3493 << Fn->getType()->isBlockPointerType() 3494 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 3495 Call->setNumArgs(Context, NumArgsInProto); 3496 } 3497 3498 // If too many are passed and not variadic, error on the extras and drop 3499 // them. 3500 if (NumArgs > NumArgsInProto) { 3501 if (!Proto->isVariadic()) { 3502 Diag(Args[NumArgsInProto]->getLocStart(), 3503 diag::err_typecheck_call_too_many_args) 3504 << Fn->getType()->isBlockPointerType() 3505 << NumArgsInProto << NumArgs << Fn->getSourceRange() 3506 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3507 Args[NumArgs-1]->getLocEnd()); 3508 // This deletes the extra arguments. 3509 Call->setNumArgs(Context, NumArgsInProto); 3510 return true; 3511 } 3512 } 3513 llvm::SmallVector<Expr *, 8> AllArgs; 3514 VariadicCallType CallType = 3515 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3516 if (Fn->getType()->isBlockPointerType()) 3517 CallType = VariadicBlock; // Block 3518 else if (isa<MemberExpr>(Fn)) 3519 CallType = VariadicMethod; 3520 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3521 Proto, 0, Args, NumArgs, AllArgs, CallType); 3522 if (Invalid) 3523 return true; 3524 unsigned TotalNumArgs = AllArgs.size(); 3525 for (unsigned i = 0; i < TotalNumArgs; ++i) 3526 Call->setArg(i, AllArgs[i]); 3527 3528 return false; 3529} 3530 3531bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3532 FunctionDecl *FDecl, 3533 const FunctionProtoType *Proto, 3534 unsigned FirstProtoArg, 3535 Expr **Args, unsigned NumArgs, 3536 llvm::SmallVector<Expr *, 8> &AllArgs, 3537 VariadicCallType CallType) { 3538 unsigned NumArgsInProto = Proto->getNumArgs(); 3539 unsigned NumArgsToCheck = NumArgs; 3540 bool Invalid = false; 3541 if (NumArgs != NumArgsInProto) 3542 // Use default arguments for missing arguments 3543 NumArgsToCheck = NumArgsInProto; 3544 unsigned ArgIx = 0; 3545 // Continue to check argument types (even if we have too few/many args). 3546 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3547 QualType ProtoArgType = Proto->getArgType(i); 3548 3549 Expr *Arg; 3550 if (ArgIx < NumArgs) { 3551 Arg = Args[ArgIx++]; 3552 3553 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3554 ProtoArgType, 3555 PDiag(diag::err_call_incomplete_argument) 3556 << Arg->getSourceRange())) 3557 return true; 3558 3559 // Pass the argument 3560 ParmVarDecl *Param = 0; 3561 if (FDecl && i < FDecl->getNumParams()) 3562 Param = FDecl->getParamDecl(i); 3563 3564 3565 InitializedEntity Entity = 3566 Param? InitializedEntity::InitializeParameter(Param) 3567 : InitializedEntity::InitializeParameter(ProtoArgType); 3568 ExprResult ArgE = PerformCopyInitialization(Entity, 3569 SourceLocation(), 3570 Owned(Arg)); 3571 if (ArgE.isInvalid()) 3572 return true; 3573 3574 Arg = ArgE.takeAs<Expr>(); 3575 } else { 3576 ParmVarDecl *Param = FDecl->getParamDecl(i); 3577 3578 ExprResult ArgExpr = 3579 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3580 if (ArgExpr.isInvalid()) 3581 return true; 3582 3583 Arg = ArgExpr.takeAs<Expr>(); 3584 } 3585 AllArgs.push_back(Arg); 3586 } 3587 3588 // If this is a variadic call, handle args passed through "...". 3589 if (CallType != VariadicDoesNotApply) { 3590 // Promote the arguments (C99 6.5.2.2p7). 3591 for (unsigned i = ArgIx; i != NumArgs; ++i) { 3592 Expr *Arg = Args[i]; 3593 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 3594 AllArgs.push_back(Arg); 3595 } 3596 } 3597 return Invalid; 3598} 3599 3600/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3601/// This provides the location of the left/right parens and a list of comma 3602/// locations. 3603ExprResult 3604Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, 3605 MultiExprArg args, SourceLocation RParenLoc) { 3606 unsigned NumArgs = args.size(); 3607 3608 // Since this might be a postfix expression, get rid of ParenListExprs. 3609 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); 3610 if (Result.isInvalid()) return ExprError(); 3611 Fn = Result.take(); 3612 3613 Expr **Args = args.release(); 3614 3615 if (getLangOptions().CPlusPlus) { 3616 // If this is a pseudo-destructor expression, build the call immediately. 3617 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3618 if (NumArgs > 0) { 3619 // Pseudo-destructor calls should not have any arguments. 3620 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3621 << FixItHint::CreateRemoval( 3622 SourceRange(Args[0]->getLocStart(), 3623 Args[NumArgs-1]->getLocEnd())); 3624 3625 NumArgs = 0; 3626 } 3627 3628 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3629 RParenLoc)); 3630 } 3631 3632 // Determine whether this is a dependent call inside a C++ template, 3633 // in which case we won't do any semantic analysis now. 3634 // FIXME: Will need to cache the results of name lookup (including ADL) in 3635 // Fn. 3636 bool Dependent = false; 3637 if (Fn->isTypeDependent()) 3638 Dependent = true; 3639 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3640 Dependent = true; 3641 3642 if (Dependent) 3643 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3644 Context.DependentTy, RParenLoc)); 3645 3646 // Determine whether this is a call to an object (C++ [over.call.object]). 3647 if (Fn->getType()->isRecordType()) 3648 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3649 RParenLoc)); 3650 3651 Expr *NakedFn = Fn->IgnoreParens(); 3652 3653 // Determine whether this is a call to an unresolved member function. 3654 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3655 // If lookup was unresolved but not dependent (i.e. didn't find 3656 // an unresolved using declaration), it has to be an overloaded 3657 // function set, which means it must contain either multiple 3658 // declarations (all methods or method templates) or a single 3659 // method template. 3660 assert((MemE->getNumDecls() > 1) || 3661 isa<FunctionTemplateDecl>( 3662 (*MemE->decls_begin())->getUnderlyingDecl())); 3663 (void)MemE; 3664 3665 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3666 RParenLoc); 3667 } 3668 3669 // Determine whether this is a call to a member function. 3670 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3671 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3672 if (isa<CXXMethodDecl>(MemDecl)) 3673 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3674 RParenLoc); 3675 } 3676 3677 // Determine whether this is a call to a pointer-to-member function. 3678 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3679 if (BO->getOpcode() == BO_PtrMemD || 3680 BO->getOpcode() == BO_PtrMemI) { 3681 if (const FunctionProtoType *FPT 3682 = BO->getType()->getAs<FunctionProtoType>()) { 3683 QualType ResultTy = FPT->getCallResultType(Context); 3684 3685 CXXMemberCallExpr *TheCall 3686 = new (Context) CXXMemberCallExpr(Context, BO, Args, 3687 NumArgs, ResultTy, 3688 RParenLoc); 3689 3690 if (CheckCallReturnType(FPT->getResultType(), 3691 BO->getRHS()->getSourceRange().getBegin(), 3692 TheCall, 0)) 3693 return ExprError(); 3694 3695 if (ConvertArgumentsForCall(TheCall, BO, 0, FPT, Args, NumArgs, 3696 RParenLoc)) 3697 return ExprError(); 3698 3699 return MaybeBindToTemporary(TheCall); 3700 } 3701 return ExprError(Diag(Fn->getLocStart(), 3702 diag::err_typecheck_call_not_function) 3703 << Fn->getType() << Fn->getSourceRange()); 3704 } 3705 } 3706 } 3707 3708 // If we're directly calling a function, get the appropriate declaration. 3709 // Also, in C++, keep track of whether we should perform argument-dependent 3710 // lookup and whether there were any explicitly-specified template arguments. 3711 3712 Expr *NakedFn = Fn->IgnoreParens(); 3713 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3714 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3715 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 3716 RParenLoc); 3717 } 3718 3719 NamedDecl *NDecl = 0; 3720 if (isa<DeclRefExpr>(NakedFn)) 3721 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3722 3723 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3724} 3725 3726/// BuildResolvedCallExpr - Build a call to a resolved expression, 3727/// i.e. an expression not of \p OverloadTy. The expression should 3728/// unary-convert to an expression of function-pointer or 3729/// block-pointer type. 3730/// 3731/// \param NDecl the declaration being called, if available 3732ExprResult 3733Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3734 SourceLocation LParenLoc, 3735 Expr **Args, unsigned NumArgs, 3736 SourceLocation RParenLoc) { 3737 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3738 3739 // Promote the function operand. 3740 UsualUnaryConversions(Fn); 3741 3742 // Make the call expr early, before semantic checks. This guarantees cleanup 3743 // of arguments and function on error. 3744 CallExpr *TheCall = new (Context) CallExpr(Context, Fn, 3745 Args, NumArgs, 3746 Context.BoolTy, 3747 RParenLoc); 3748 3749 const FunctionType *FuncT; 3750 if (!Fn->getType()->isBlockPointerType()) { 3751 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3752 // have type pointer to function". 3753 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3754 if (PT == 0) 3755 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3756 << Fn->getType() << Fn->getSourceRange()); 3757 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3758 } else { // This is a block call. 3759 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3760 getAs<FunctionType>(); 3761 } 3762 if (FuncT == 0) 3763 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3764 << Fn->getType() << Fn->getSourceRange()); 3765 3766 // Check for a valid return type 3767 if (CheckCallReturnType(FuncT->getResultType(), 3768 Fn->getSourceRange().getBegin(), TheCall, 3769 FDecl)) 3770 return ExprError(); 3771 3772 // We know the result type of the call, set it. 3773 TheCall->setType(FuncT->getCallResultType(Context)); 3774 3775 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3776 if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, NumArgs, 3777 RParenLoc)) 3778 return ExprError(); 3779 } else { 3780 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3781 3782 if (FDecl) { 3783 // Check if we have too few/too many template arguments, based 3784 // on our knowledge of the function definition. 3785 const FunctionDecl *Def = 0; 3786 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 3787 const FunctionProtoType *Proto = 3788 Def->getType()->getAs<FunctionProtoType>(); 3789 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3790 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3791 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3792 } 3793 } 3794 } 3795 3796 // Promote the arguments (C99 6.5.2.2p6). 3797 for (unsigned i = 0; i != NumArgs; i++) { 3798 Expr *Arg = Args[i]; 3799 DefaultArgumentPromotion(Arg); 3800 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3801 Arg->getType(), 3802 PDiag(diag::err_call_incomplete_argument) 3803 << Arg->getSourceRange())) 3804 return ExprError(); 3805 TheCall->setArg(i, Arg); 3806 } 3807 } 3808 3809 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3810 if (!Method->isStatic()) 3811 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3812 << Fn->getSourceRange()); 3813 3814 // Check for sentinels 3815 if (NDecl) 3816 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3817 3818 // Do special checking on direct calls to functions. 3819 if (FDecl) { 3820 if (CheckFunctionCall(FDecl, TheCall)) 3821 return ExprError(); 3822 3823 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3824 return CheckBuiltinFunctionCall(BuiltinID, TheCall); 3825 } else if (NDecl) { 3826 if (CheckBlockCall(NDecl, TheCall)) 3827 return ExprError(); 3828 } 3829 3830 return MaybeBindToTemporary(TheCall); 3831} 3832 3833ExprResult 3834Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, 3835 SourceLocation RParenLoc, Expr *InitExpr) { 3836 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3837 // FIXME: put back this assert when initializers are worked out. 3838 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3839 3840 TypeSourceInfo *TInfo; 3841 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3842 if (!TInfo) 3843 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3844 3845 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); 3846} 3847 3848ExprResult 3849Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3850 SourceLocation RParenLoc, Expr *literalExpr) { 3851 QualType literalType = TInfo->getType(); 3852 3853 if (literalType->isArrayType()) { 3854 if (literalType->isVariableArrayType()) 3855 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3856 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3857 } else if (!literalType->isDependentType() && 3858 RequireCompleteType(LParenLoc, literalType, 3859 PDiag(diag::err_typecheck_decl_incomplete_type) 3860 << SourceRange(LParenLoc, 3861 literalExpr->getSourceRange().getEnd()))) 3862 return ExprError(); 3863 3864 InitializedEntity Entity 3865 = InitializedEntity::InitializeTemporary(literalType); 3866 InitializationKind Kind 3867 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3868 /*IsCStyleCast=*/true); 3869 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3870 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3871 MultiExprArg(*this, &literalExpr, 1), 3872 &literalType); 3873 if (Result.isInvalid()) 3874 return ExprError(); 3875 literalExpr = Result.get(); 3876 3877 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3878 if (isFileScope) { // 6.5.2.5p3 3879 if (CheckForConstantInitializer(literalExpr, literalType)) 3880 return ExprError(); 3881 } 3882 3883 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3884 literalExpr, isFileScope)); 3885} 3886 3887ExprResult 3888Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3889 SourceLocation RBraceLoc) { 3890 unsigned NumInit = initlist.size(); 3891 Expr **InitList = initlist.release(); 3892 3893 // Semantic analysis for initializers is done by ActOnDeclarator() and 3894 // CheckInitializer() - it requires knowledge of the object being intialized. 3895 3896 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 3897 NumInit, RBraceLoc); 3898 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3899 return Owned(E); 3900} 3901 3902static CastKind getScalarCastKind(ASTContext &Context, 3903 QualType SrcTy, QualType DestTy) { 3904 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3905 return CK_NoOp; 3906 3907 if (SrcTy->hasPointerRepresentation()) { 3908 if (DestTy->hasPointerRepresentation()) 3909 return DestTy->isObjCObjectPointerType() ? 3910 CK_AnyPointerToObjCPointerCast : 3911 CK_BitCast; 3912 if (DestTy->isIntegerType()) 3913 return CK_PointerToIntegral; 3914 } 3915 3916 if (SrcTy->isIntegerType()) { 3917 if (DestTy->isIntegerType()) 3918 return CK_IntegralCast; 3919 if (DestTy->hasPointerRepresentation()) 3920 return CK_IntegralToPointer; 3921 if (DestTy->isRealFloatingType()) 3922 return CK_IntegralToFloating; 3923 } 3924 3925 if (SrcTy->isRealFloatingType()) { 3926 if (DestTy->isRealFloatingType()) 3927 return CK_FloatingCast; 3928 if (DestTy->isIntegerType()) 3929 return CK_FloatingToIntegral; 3930 } 3931 3932 // FIXME: Assert here. 3933 // assert(false && "Unhandled cast combination!"); 3934 return CK_Unknown; 3935} 3936 3937/// CheckCastTypes - Check type constraints for casting between types. 3938bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3939 CastKind& Kind, 3940 CXXCastPath &BasePath, 3941 bool FunctionalStyle) { 3942 if (getLangOptions().CPlusPlus) 3943 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, BasePath, 3944 FunctionalStyle); 3945 3946 DefaultFunctionArrayLvalueConversion(castExpr); 3947 3948 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3949 // type needs to be scalar. 3950 if (castType->isVoidType()) { 3951 // Cast to void allows any expr type. 3952 Kind = CK_ToVoid; 3953 return false; 3954 } 3955 3956 if (RequireCompleteType(TyR.getBegin(), castType, 3957 diag::err_typecheck_cast_to_incomplete)) 3958 return true; 3959 3960 if (!castType->isScalarType() && !castType->isVectorType()) { 3961 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3962 (castType->isStructureType() || castType->isUnionType())) { 3963 // GCC struct/union extension: allow cast to self. 3964 // FIXME: Check that the cast destination type is complete. 3965 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3966 << castType << castExpr->getSourceRange(); 3967 Kind = CK_NoOp; 3968 return false; 3969 } 3970 3971 if (castType->isUnionType()) { 3972 // GCC cast to union extension 3973 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3974 RecordDecl::field_iterator Field, FieldEnd; 3975 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3976 Field != FieldEnd; ++Field) { 3977 if (Context.hasSameUnqualifiedType(Field->getType(), 3978 castExpr->getType())) { 3979 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3980 << castExpr->getSourceRange(); 3981 break; 3982 } 3983 } 3984 if (Field == FieldEnd) 3985 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3986 << castExpr->getType() << castExpr->getSourceRange(); 3987 Kind = CK_ToUnion; 3988 return false; 3989 } 3990 3991 // Reject any other conversions to non-scalar types. 3992 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3993 << castType << castExpr->getSourceRange(); 3994 } 3995 3996 if (!castExpr->getType()->isScalarType() && 3997 !castExpr->getType()->isVectorType()) { 3998 return Diag(castExpr->getLocStart(), 3999 diag::err_typecheck_expect_scalar_operand) 4000 << castExpr->getType() << castExpr->getSourceRange(); 4001 } 4002 4003 if (castType->isExtVectorType()) 4004 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 4005 4006 if (castType->isVectorType()) 4007 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 4008 if (castExpr->getType()->isVectorType()) 4009 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 4010 4011 if (isa<ObjCSelectorExpr>(castExpr)) 4012 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 4013 4014 if (!castType->isArithmeticType()) { 4015 QualType castExprType = castExpr->getType(); 4016 if (!castExprType->isIntegralType(Context) && 4017 castExprType->isArithmeticType()) 4018 return Diag(castExpr->getLocStart(), 4019 diag::err_cast_pointer_from_non_pointer_int) 4020 << castExprType << castExpr->getSourceRange(); 4021 } else if (!castExpr->getType()->isArithmeticType()) { 4022 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 4023 return Diag(castExpr->getLocStart(), 4024 diag::err_cast_pointer_to_non_pointer_int) 4025 << castType << castExpr->getSourceRange(); 4026 } 4027 4028 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 4029 4030 if (Kind == CK_Unknown || Kind == CK_BitCast) 4031 CheckCastAlign(castExpr, castType, TyR); 4032 4033 return false; 4034} 4035 4036bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 4037 CastKind &Kind) { 4038 assert(VectorTy->isVectorType() && "Not a vector type!"); 4039 4040 if (Ty->isVectorType() || Ty->isIntegerType()) { 4041 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 4042 return Diag(R.getBegin(), 4043 Ty->isVectorType() ? 4044 diag::err_invalid_conversion_between_vectors : 4045 diag::err_invalid_conversion_between_vector_and_integer) 4046 << VectorTy << Ty << R; 4047 } else 4048 return Diag(R.getBegin(), 4049 diag::err_invalid_conversion_between_vector_and_scalar) 4050 << VectorTy << Ty << R; 4051 4052 Kind = CK_BitCast; 4053 return false; 4054} 4055 4056bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4057 CastKind &Kind) { 4058 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4059 4060 QualType SrcTy = CastExpr->getType(); 4061 4062 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4063 // an ExtVectorType. 4064 if (SrcTy->isVectorType()) { 4065 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4066 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4067 << DestTy << SrcTy << R; 4068 Kind = CK_BitCast; 4069 return false; 4070 } 4071 4072 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4073 // conversion will take place first from scalar to elt type, and then 4074 // splat from elt type to vector. 4075 if (SrcTy->isPointerType()) 4076 return Diag(R.getBegin(), 4077 diag::err_invalid_conversion_between_vector_and_scalar) 4078 << DestTy << SrcTy << R; 4079 4080 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4081 ImpCastExprToType(CastExpr, DestElemTy, 4082 getScalarCastKind(Context, SrcTy, DestElemTy)); 4083 4084 Kind = CK_VectorSplat; 4085 return false; 4086} 4087 4088ExprResult 4089Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, ParsedType Ty, 4090 SourceLocation RParenLoc, Expr *castExpr) { 4091 assert((Ty != 0) && (castExpr != 0) && 4092 "ActOnCastExpr(): missing type or expr"); 4093 4094 TypeSourceInfo *castTInfo; 4095 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4096 if (!castTInfo) 4097 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4098 4099 // If the Expr being casted is a ParenListExpr, handle it specially. 4100 if (isa<ParenListExpr>(castExpr)) 4101 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, castExpr, 4102 castTInfo); 4103 4104 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, castExpr); 4105} 4106 4107ExprResult 4108Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4109 SourceLocation RParenLoc, Expr *castExpr) { 4110 CastKind Kind = CK_Unknown; 4111 CXXCastPath BasePath; 4112 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4113 Kind, BasePath)) 4114 return ExprError(); 4115 4116 return Owned(CStyleCastExpr::Create(Context, 4117 Ty->getType().getNonLValueExprType(Context), 4118 Kind, castExpr, &BasePath, Ty, 4119 LParenLoc, RParenLoc)); 4120} 4121 4122/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4123/// of comma binary operators. 4124ExprResult 4125Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *expr) { 4126 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4127 if (!E) 4128 return Owned(expr); 4129 4130 ExprResult Result(E->getExpr(0)); 4131 4132 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4133 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), 4134 E->getExpr(i)); 4135 4136 if (Result.isInvalid()) return ExprError(); 4137 4138 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); 4139} 4140 4141ExprResult 4142Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4143 SourceLocation RParenLoc, Expr *Op, 4144 TypeSourceInfo *TInfo) { 4145 ParenListExpr *PE = cast<ParenListExpr>(Op); 4146 QualType Ty = TInfo->getType(); 4147 bool isAltiVecLiteral = false; 4148 4149 // Check for an altivec literal, 4150 // i.e. all the elements are integer constants. 4151 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4152 if (PE->getNumExprs() == 0) { 4153 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4154 return ExprError(); 4155 } 4156 if (PE->getNumExprs() == 1) { 4157 if (!PE->getExpr(0)->getType()->isVectorType()) 4158 isAltiVecLiteral = true; 4159 } 4160 else 4161 isAltiVecLiteral = true; 4162 } 4163 4164 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4165 // then handle it as such. 4166 if (isAltiVecLiteral) { 4167 llvm::SmallVector<Expr *, 8> initExprs; 4168 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4169 initExprs.push_back(PE->getExpr(i)); 4170 4171 // FIXME: This means that pretty-printing the final AST will produce curly 4172 // braces instead of the original commas. 4173 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4174 &initExprs[0], 4175 initExprs.size(), RParenLoc); 4176 E->setType(Ty); 4177 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, E); 4178 } else { 4179 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4180 // sequence of BinOp comma operators. 4181 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Op); 4182 if (Result.isInvalid()) return ExprError(); 4183 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Result.take()); 4184 } 4185} 4186 4187ExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4188 SourceLocation R, 4189 MultiExprArg Val, 4190 ParsedType TypeOfCast) { 4191 unsigned nexprs = Val.size(); 4192 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4193 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4194 Expr *expr; 4195 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4196 expr = new (Context) ParenExpr(L, R, exprs[0]); 4197 else 4198 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4199 return Owned(expr); 4200} 4201 4202/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4203/// In that case, lhs = cond. 4204/// C99 6.5.15 4205QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4206 SourceLocation QuestionLoc) { 4207 // C++ is sufficiently different to merit its own checker. 4208 if (getLangOptions().CPlusPlus) 4209 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4210 4211 UsualUnaryConversions(Cond); 4212 UsualUnaryConversions(LHS); 4213 UsualUnaryConversions(RHS); 4214 QualType CondTy = Cond->getType(); 4215 QualType LHSTy = LHS->getType(); 4216 QualType RHSTy = RHS->getType(); 4217 4218 // first, check the condition. 4219 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4220 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4221 << CondTy; 4222 return QualType(); 4223 } 4224 4225 // Now check the two expressions. 4226 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4227 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4228 4229 // If both operands have arithmetic type, do the usual arithmetic conversions 4230 // to find a common type: C99 6.5.15p3,5. 4231 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4232 UsualArithmeticConversions(LHS, RHS); 4233 return LHS->getType(); 4234 } 4235 4236 // If both operands are the same structure or union type, the result is that 4237 // type. 4238 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4239 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4240 if (LHSRT->getDecl() == RHSRT->getDecl()) 4241 // "If both the operands have structure or union type, the result has 4242 // that type." This implies that CV qualifiers are dropped. 4243 return LHSTy.getUnqualifiedType(); 4244 // FIXME: Type of conditional expression must be complete in C mode. 4245 } 4246 4247 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4248 // The following || allows only one side to be void (a GCC-ism). 4249 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4250 if (!LHSTy->isVoidType()) 4251 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4252 << RHS->getSourceRange(); 4253 if (!RHSTy->isVoidType()) 4254 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4255 << LHS->getSourceRange(); 4256 ImpCastExprToType(LHS, Context.VoidTy, CK_ToVoid); 4257 ImpCastExprToType(RHS, Context.VoidTy, CK_ToVoid); 4258 return Context.VoidTy; 4259 } 4260 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4261 // the type of the other operand." 4262 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4263 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4264 // promote the null to a pointer. 4265 ImpCastExprToType(RHS, LHSTy, CK_Unknown); 4266 return LHSTy; 4267 } 4268 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4269 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4270 ImpCastExprToType(LHS, RHSTy, CK_Unknown); 4271 return RHSTy; 4272 } 4273 4274 // All objective-c pointer type analysis is done here. 4275 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4276 QuestionLoc); 4277 if (!compositeType.isNull()) 4278 return compositeType; 4279 4280 4281 // Handle block pointer types. 4282 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4283 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4284 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4285 QualType destType = Context.getPointerType(Context.VoidTy); 4286 ImpCastExprToType(LHS, destType, CK_BitCast); 4287 ImpCastExprToType(RHS, destType, CK_BitCast); 4288 return destType; 4289 } 4290 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4291 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4292 return QualType(); 4293 } 4294 // We have 2 block pointer types. 4295 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4296 // Two identical block pointer types are always compatible. 4297 return LHSTy; 4298 } 4299 // The block pointer types aren't identical, continue checking. 4300 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4301 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4302 4303 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4304 rhptee.getUnqualifiedType())) { 4305 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4306 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4307 // In this situation, we assume void* type. No especially good 4308 // reason, but this is what gcc does, and we do have to pick 4309 // to get a consistent AST. 4310 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4311 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4312 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4313 return incompatTy; 4314 } 4315 // The block pointer types are compatible. 4316 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 4317 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4318 return LHSTy; 4319 } 4320 4321 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4322 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4323 // get the "pointed to" types 4324 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4325 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4326 4327 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4328 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4329 // Figure out necessary qualifiers (C99 6.5.15p6) 4330 QualType destPointee 4331 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4332 QualType destType = Context.getPointerType(destPointee); 4333 // Add qualifiers if necessary. 4334 ImpCastExprToType(LHS, destType, CK_NoOp); 4335 // Promote to void*. 4336 ImpCastExprToType(RHS, destType, CK_BitCast); 4337 return destType; 4338 } 4339 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4340 QualType destPointee 4341 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4342 QualType destType = Context.getPointerType(destPointee); 4343 // Add qualifiers if necessary. 4344 ImpCastExprToType(RHS, destType, CK_NoOp); 4345 // Promote to void*. 4346 ImpCastExprToType(LHS, destType, CK_BitCast); 4347 return destType; 4348 } 4349 4350 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4351 // Two identical pointer types are always compatible. 4352 return LHSTy; 4353 } 4354 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4355 rhptee.getUnqualifiedType())) { 4356 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4357 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4358 // In this situation, we assume void* type. No especially good 4359 // reason, but this is what gcc does, and we do have to pick 4360 // to get a consistent AST. 4361 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4362 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4363 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4364 return incompatTy; 4365 } 4366 // The pointer types are compatible. 4367 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4368 // differently qualified versions of compatible types, the result type is 4369 // a pointer to an appropriately qualified version of the *composite* 4370 // type. 4371 // FIXME: Need to calculate the composite type. 4372 // FIXME: Need to add qualifiers 4373 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 4374 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4375 return LHSTy; 4376 } 4377 4378 // GCC compatibility: soften pointer/integer mismatch. 4379 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4380 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4381 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4382 ImpCastExprToType(LHS, RHSTy, CK_IntegralToPointer); 4383 return RHSTy; 4384 } 4385 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4386 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4387 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4388 ImpCastExprToType(RHS, LHSTy, CK_IntegralToPointer); 4389 return LHSTy; 4390 } 4391 4392 // Otherwise, the operands are not compatible. 4393 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4394 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4395 return QualType(); 4396} 4397 4398/// FindCompositeObjCPointerType - Helper method to find composite type of 4399/// two objective-c pointer types of the two input expressions. 4400QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4401 SourceLocation QuestionLoc) { 4402 QualType LHSTy = LHS->getType(); 4403 QualType RHSTy = RHS->getType(); 4404 4405 // Handle things like Class and struct objc_class*. Here we case the result 4406 // to the pseudo-builtin, because that will be implicitly cast back to the 4407 // redefinition type if an attempt is made to access its fields. 4408 if (LHSTy->isObjCClassType() && 4409 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4410 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4411 return LHSTy; 4412 } 4413 if (RHSTy->isObjCClassType() && 4414 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4415 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4416 return RHSTy; 4417 } 4418 // And the same for struct objc_object* / id 4419 if (LHSTy->isObjCIdType() && 4420 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4421 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4422 return LHSTy; 4423 } 4424 if (RHSTy->isObjCIdType() && 4425 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4426 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4427 return RHSTy; 4428 } 4429 // And the same for struct objc_selector* / SEL 4430 if (Context.isObjCSelType(LHSTy) && 4431 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4432 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4433 return LHSTy; 4434 } 4435 if (Context.isObjCSelType(RHSTy) && 4436 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4437 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4438 return RHSTy; 4439 } 4440 // Check constraints for Objective-C object pointers types. 4441 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4442 4443 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4444 // Two identical object pointer types are always compatible. 4445 return LHSTy; 4446 } 4447 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4448 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4449 QualType compositeType = LHSTy; 4450 4451 // If both operands are interfaces and either operand can be 4452 // assigned to the other, use that type as the composite 4453 // type. This allows 4454 // xxx ? (A*) a : (B*) b 4455 // where B is a subclass of A. 4456 // 4457 // Additionally, as for assignment, if either type is 'id' 4458 // allow silent coercion. Finally, if the types are 4459 // incompatible then make sure to use 'id' as the composite 4460 // type so the result is acceptable for sending messages to. 4461 4462 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4463 // It could return the composite type. 4464 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4465 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4466 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4467 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4468 } else if ((LHSTy->isObjCQualifiedIdType() || 4469 RHSTy->isObjCQualifiedIdType()) && 4470 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4471 // Need to handle "id<xx>" explicitly. 4472 // GCC allows qualified id and any Objective-C type to devolve to 4473 // id. Currently localizing to here until clear this should be 4474 // part of ObjCQualifiedIdTypesAreCompatible. 4475 compositeType = Context.getObjCIdType(); 4476 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4477 compositeType = Context.getObjCIdType(); 4478 } else if (!(compositeType = 4479 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4480 ; 4481 else { 4482 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4483 << LHSTy << RHSTy 4484 << LHS->getSourceRange() << RHS->getSourceRange(); 4485 QualType incompatTy = Context.getObjCIdType(); 4486 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4487 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4488 return incompatTy; 4489 } 4490 // The object pointer types are compatible. 4491 ImpCastExprToType(LHS, compositeType, CK_BitCast); 4492 ImpCastExprToType(RHS, compositeType, CK_BitCast); 4493 return compositeType; 4494 } 4495 // Check Objective-C object pointer types and 'void *' 4496 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4497 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4498 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4499 QualType destPointee 4500 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4501 QualType destType = Context.getPointerType(destPointee); 4502 // Add qualifiers if necessary. 4503 ImpCastExprToType(LHS, destType, CK_NoOp); 4504 // Promote to void*. 4505 ImpCastExprToType(RHS, destType, CK_BitCast); 4506 return destType; 4507 } 4508 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4509 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4510 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4511 QualType destPointee 4512 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4513 QualType destType = Context.getPointerType(destPointee); 4514 // Add qualifiers if necessary. 4515 ImpCastExprToType(RHS, destType, CK_NoOp); 4516 // Promote to void*. 4517 ImpCastExprToType(LHS, destType, CK_BitCast); 4518 return destType; 4519 } 4520 return QualType(); 4521} 4522 4523/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4524/// in the case of a the GNU conditional expr extension. 4525ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4526 SourceLocation ColonLoc, 4527 Expr *CondExpr, Expr *LHSExpr, 4528 Expr *RHSExpr) { 4529 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4530 // was the condition. 4531 bool isLHSNull = LHSExpr == 0; 4532 Expr *SAVEExpr = 0; 4533 if (isLHSNull) { 4534 LHSExpr = SAVEExpr = CondExpr; 4535 } 4536 4537 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4538 RHSExpr, QuestionLoc); 4539 if (result.isNull()) 4540 return ExprError(); 4541 4542 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4543 LHSExpr, ColonLoc, 4544 RHSExpr, SAVEExpr, 4545 result)); 4546} 4547 4548// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4549// being closely modeled after the C99 spec:-). The odd characteristic of this 4550// routine is it effectively iqnores the qualifiers on the top level pointee. 4551// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4552// FIXME: add a couple examples in this comment. 4553Sema::AssignConvertType 4554Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4555 QualType lhptee, rhptee; 4556 4557 if ((lhsType->isObjCClassType() && 4558 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4559 (rhsType->isObjCClassType() && 4560 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4561 return Compatible; 4562 } 4563 4564 // get the "pointed to" type (ignoring qualifiers at the top level) 4565 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4566 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4567 4568 // make sure we operate on the canonical type 4569 lhptee = Context.getCanonicalType(lhptee); 4570 rhptee = Context.getCanonicalType(rhptee); 4571 4572 AssignConvertType ConvTy = Compatible; 4573 4574 // C99 6.5.16.1p1: This following citation is common to constraints 4575 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4576 // qualifiers of the type *pointed to* by the right; 4577 // FIXME: Handle ExtQualType 4578 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4579 ConvTy = CompatiblePointerDiscardsQualifiers; 4580 4581 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4582 // incomplete type and the other is a pointer to a qualified or unqualified 4583 // version of void... 4584 if (lhptee->isVoidType()) { 4585 if (rhptee->isIncompleteOrObjectType()) 4586 return ConvTy; 4587 4588 // As an extension, we allow cast to/from void* to function pointer. 4589 assert(rhptee->isFunctionType()); 4590 return FunctionVoidPointer; 4591 } 4592 4593 if (rhptee->isVoidType()) { 4594 if (lhptee->isIncompleteOrObjectType()) 4595 return ConvTy; 4596 4597 // As an extension, we allow cast to/from void* to function pointer. 4598 assert(lhptee->isFunctionType()); 4599 return FunctionVoidPointer; 4600 } 4601 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4602 // unqualified versions of compatible types, ... 4603 lhptee = lhptee.getUnqualifiedType(); 4604 rhptee = rhptee.getUnqualifiedType(); 4605 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4606 // Check if the pointee types are compatible ignoring the sign. 4607 // We explicitly check for char so that we catch "char" vs 4608 // "unsigned char" on systems where "char" is unsigned. 4609 if (lhptee->isCharType()) 4610 lhptee = Context.UnsignedCharTy; 4611 else if (lhptee->hasSignedIntegerRepresentation()) 4612 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4613 4614 if (rhptee->isCharType()) 4615 rhptee = Context.UnsignedCharTy; 4616 else if (rhptee->hasSignedIntegerRepresentation()) 4617 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4618 4619 if (lhptee == rhptee) { 4620 // Types are compatible ignoring the sign. Qualifier incompatibility 4621 // takes priority over sign incompatibility because the sign 4622 // warning can be disabled. 4623 if (ConvTy != Compatible) 4624 return ConvTy; 4625 return IncompatiblePointerSign; 4626 } 4627 4628 // If we are a multi-level pointer, it's possible that our issue is simply 4629 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4630 // the eventual target type is the same and the pointers have the same 4631 // level of indirection, this must be the issue. 4632 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4633 do { 4634 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4635 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4636 4637 lhptee = Context.getCanonicalType(lhptee); 4638 rhptee = Context.getCanonicalType(rhptee); 4639 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4640 4641 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4642 return IncompatibleNestedPointerQualifiers; 4643 } 4644 4645 // General pointer incompatibility takes priority over qualifiers. 4646 return IncompatiblePointer; 4647 } 4648 return ConvTy; 4649} 4650 4651/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4652/// block pointer types are compatible or whether a block and normal pointer 4653/// are compatible. It is more restrict than comparing two function pointer 4654// types. 4655Sema::AssignConvertType 4656Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4657 QualType rhsType) { 4658 QualType lhptee, rhptee; 4659 4660 // get the "pointed to" type (ignoring qualifiers at the top level) 4661 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4662 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4663 4664 // make sure we operate on the canonical type 4665 lhptee = Context.getCanonicalType(lhptee); 4666 rhptee = Context.getCanonicalType(rhptee); 4667 4668 AssignConvertType ConvTy = Compatible; 4669 4670 // For blocks we enforce that qualifiers are identical. 4671 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4672 ConvTy = CompatiblePointerDiscardsQualifiers; 4673 4674 if (!getLangOptions().CPlusPlus) { 4675 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4676 return IncompatibleBlockPointer; 4677 } 4678 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4679 return IncompatibleBlockPointer; 4680 return ConvTy; 4681} 4682 4683/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4684/// for assignment compatibility. 4685Sema::AssignConvertType 4686Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4687 if (lhsType->isObjCBuiltinType()) { 4688 // Class is not compatible with ObjC object pointers. 4689 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4690 !rhsType->isObjCQualifiedClassType()) 4691 return IncompatiblePointer; 4692 return Compatible; 4693 } 4694 if (rhsType->isObjCBuiltinType()) { 4695 // Class is not compatible with ObjC object pointers. 4696 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4697 !lhsType->isObjCQualifiedClassType()) 4698 return IncompatiblePointer; 4699 return Compatible; 4700 } 4701 QualType lhptee = 4702 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4703 QualType rhptee = 4704 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4705 // make sure we operate on the canonical type 4706 lhptee = Context.getCanonicalType(lhptee); 4707 rhptee = Context.getCanonicalType(rhptee); 4708 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4709 return CompatiblePointerDiscardsQualifiers; 4710 4711 if (Context.typesAreCompatible(lhsType, rhsType)) 4712 return Compatible; 4713 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4714 return IncompatibleObjCQualifiedId; 4715 return IncompatiblePointer; 4716} 4717 4718/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4719/// has code to accommodate several GCC extensions when type checking 4720/// pointers. Here are some objectionable examples that GCC considers warnings: 4721/// 4722/// int a, *pint; 4723/// short *pshort; 4724/// struct foo *pfoo; 4725/// 4726/// pint = pshort; // warning: assignment from incompatible pointer type 4727/// a = pint; // warning: assignment makes integer from pointer without a cast 4728/// pint = a; // warning: assignment makes pointer from integer without a cast 4729/// pint = pfoo; // warning: assignment from incompatible pointer type 4730/// 4731/// As a result, the code for dealing with pointers is more complex than the 4732/// C99 spec dictates. 4733/// 4734Sema::AssignConvertType 4735Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4736 // Get canonical types. We're not formatting these types, just comparing 4737 // them. 4738 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4739 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4740 4741 if (lhsType == rhsType) 4742 return Compatible; // Common case: fast path an exact match. 4743 4744 if ((lhsType->isObjCClassType() && 4745 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4746 (rhsType->isObjCClassType() && 4747 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4748 return Compatible; 4749 } 4750 4751 // If the left-hand side is a reference type, then we are in a 4752 // (rare!) case where we've allowed the use of references in C, 4753 // e.g., as a parameter type in a built-in function. In this case, 4754 // just make sure that the type referenced is compatible with the 4755 // right-hand side type. The caller is responsible for adjusting 4756 // lhsType so that the resulting expression does not have reference 4757 // type. 4758 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4759 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4760 return Compatible; 4761 return Incompatible; 4762 } 4763 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4764 // to the same ExtVector type. 4765 if (lhsType->isExtVectorType()) { 4766 if (rhsType->isExtVectorType()) 4767 return lhsType == rhsType ? Compatible : Incompatible; 4768 if (rhsType->isArithmeticType()) 4769 return Compatible; 4770 } 4771 4772 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4773 if (lhsType->isVectorType() && rhsType->isVectorType()) { 4774 // If we are allowing lax vector conversions, and LHS and RHS are both 4775 // vectors, the total size only needs to be the same. This is a bitcast; 4776 // no bits are changed but the result type is different. 4777 if (getLangOptions().LaxVectorConversions && 4778 (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) 4779 return IncompatibleVectors; 4780 4781 // Allow assignments of an AltiVec vector type to an equivalent GCC 4782 // vector type and vice versa 4783 if (Context.areCompatibleVectorTypes(lhsType, rhsType)) 4784 return Compatible; 4785 } 4786 return Incompatible; 4787 } 4788 4789 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 4790 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) 4791 return Compatible; 4792 4793 if (isa<PointerType>(lhsType)) { 4794 if (rhsType->isIntegerType()) 4795 return IntToPointer; 4796 4797 if (isa<PointerType>(rhsType)) 4798 return CheckPointerTypesForAssignment(lhsType, rhsType); 4799 4800 // In general, C pointers are not compatible with ObjC object pointers. 4801 if (isa<ObjCObjectPointerType>(rhsType)) { 4802 if (lhsType->isVoidPointerType()) // an exception to the rule. 4803 return Compatible; 4804 return IncompatiblePointer; 4805 } 4806 if (rhsType->getAs<BlockPointerType>()) { 4807 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4808 return Compatible; 4809 4810 // Treat block pointers as objects. 4811 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4812 return Compatible; 4813 } 4814 return Incompatible; 4815 } 4816 4817 if (isa<BlockPointerType>(lhsType)) { 4818 if (rhsType->isIntegerType()) 4819 return IntToBlockPointer; 4820 4821 // Treat block pointers as objects. 4822 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4823 return Compatible; 4824 4825 if (rhsType->isBlockPointerType()) 4826 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4827 4828 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4829 if (RHSPT->getPointeeType()->isVoidType()) 4830 return Compatible; 4831 } 4832 return Incompatible; 4833 } 4834 4835 if (isa<ObjCObjectPointerType>(lhsType)) { 4836 if (rhsType->isIntegerType()) 4837 return IntToPointer; 4838 4839 // In general, C pointers are not compatible with ObjC object pointers. 4840 if (isa<PointerType>(rhsType)) { 4841 if (rhsType->isVoidPointerType()) // an exception to the rule. 4842 return Compatible; 4843 return IncompatiblePointer; 4844 } 4845 if (rhsType->isObjCObjectPointerType()) { 4846 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4847 } 4848 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4849 if (RHSPT->getPointeeType()->isVoidType()) 4850 return Compatible; 4851 } 4852 // Treat block pointers as objects. 4853 if (rhsType->isBlockPointerType()) 4854 return Compatible; 4855 return Incompatible; 4856 } 4857 if (isa<PointerType>(rhsType)) { 4858 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4859 if (lhsType == Context.BoolTy) 4860 return Compatible; 4861 4862 if (lhsType->isIntegerType()) 4863 return PointerToInt; 4864 4865 if (isa<PointerType>(lhsType)) 4866 return CheckPointerTypesForAssignment(lhsType, rhsType); 4867 4868 if (isa<BlockPointerType>(lhsType) && 4869 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4870 return Compatible; 4871 return Incompatible; 4872 } 4873 if (isa<ObjCObjectPointerType>(rhsType)) { 4874 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4875 if (lhsType == Context.BoolTy) 4876 return Compatible; 4877 4878 if (lhsType->isIntegerType()) 4879 return PointerToInt; 4880 4881 // In general, C pointers are not compatible with ObjC object pointers. 4882 if (isa<PointerType>(lhsType)) { 4883 if (lhsType->isVoidPointerType()) // an exception to the rule. 4884 return Compatible; 4885 return IncompatiblePointer; 4886 } 4887 if (isa<BlockPointerType>(lhsType) && 4888 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4889 return Compatible; 4890 return Incompatible; 4891 } 4892 4893 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4894 if (Context.typesAreCompatible(lhsType, rhsType)) 4895 return Compatible; 4896 } 4897 return Incompatible; 4898} 4899 4900/// \brief Constructs a transparent union from an expression that is 4901/// used to initialize the transparent union. 4902static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4903 QualType UnionType, FieldDecl *Field) { 4904 // Build an initializer list that designates the appropriate member 4905 // of the transparent union. 4906 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 4907 &E, 1, 4908 SourceLocation()); 4909 Initializer->setType(UnionType); 4910 Initializer->setInitializedFieldInUnion(Field); 4911 4912 // Build a compound literal constructing a value of the transparent 4913 // union type from this initializer list. 4914 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4915 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4916 Initializer, false); 4917} 4918 4919Sema::AssignConvertType 4920Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4921 QualType FromType = rExpr->getType(); 4922 4923 // If the ArgType is a Union type, we want to handle a potential 4924 // transparent_union GCC extension. 4925 const RecordType *UT = ArgType->getAsUnionType(); 4926 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4927 return Incompatible; 4928 4929 // The field to initialize within the transparent union. 4930 RecordDecl *UD = UT->getDecl(); 4931 FieldDecl *InitField = 0; 4932 // It's compatible if the expression matches any of the fields. 4933 for (RecordDecl::field_iterator it = UD->field_begin(), 4934 itend = UD->field_end(); 4935 it != itend; ++it) { 4936 if (it->getType()->isPointerType()) { 4937 // If the transparent union contains a pointer type, we allow: 4938 // 1) void pointer 4939 // 2) null pointer constant 4940 if (FromType->isPointerType()) 4941 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4942 ImpCastExprToType(rExpr, it->getType(), CK_BitCast); 4943 InitField = *it; 4944 break; 4945 } 4946 4947 if (rExpr->isNullPointerConstant(Context, 4948 Expr::NPC_ValueDependentIsNull)) { 4949 ImpCastExprToType(rExpr, it->getType(), CK_IntegralToPointer); 4950 InitField = *it; 4951 break; 4952 } 4953 } 4954 4955 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4956 == Compatible) { 4957 ImpCastExprToType(rExpr, it->getType(), CK_Unknown); 4958 InitField = *it; 4959 break; 4960 } 4961 } 4962 4963 if (!InitField) 4964 return Incompatible; 4965 4966 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4967 return Compatible; 4968} 4969 4970Sema::AssignConvertType 4971Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4972 if (getLangOptions().CPlusPlus) { 4973 if (!lhsType->isRecordType()) { 4974 // C++ 5.17p3: If the left operand is not of class type, the 4975 // expression is implicitly converted (C++ 4) to the 4976 // cv-unqualified type of the left operand. 4977 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4978 AA_Assigning)) 4979 return Incompatible; 4980 return Compatible; 4981 } 4982 4983 // FIXME: Currently, we fall through and treat C++ classes like C 4984 // structures. 4985 } 4986 4987 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4988 // a null pointer constant. 4989 if ((lhsType->isPointerType() || 4990 lhsType->isObjCObjectPointerType() || 4991 lhsType->isBlockPointerType()) 4992 && rExpr->isNullPointerConstant(Context, 4993 Expr::NPC_ValueDependentIsNull)) { 4994 ImpCastExprToType(rExpr, lhsType, CK_Unknown); 4995 return Compatible; 4996 } 4997 4998 // This check seems unnatural, however it is necessary to ensure the proper 4999 // conversion of functions/arrays. If the conversion were done for all 5000 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 5001 // expressions that suppress this implicit conversion (&, sizeof). 5002 // 5003 // Suppress this for references: C++ 8.5.3p5. 5004 if (!lhsType->isReferenceType()) 5005 DefaultFunctionArrayLvalueConversion(rExpr); 5006 5007 Sema::AssignConvertType result = 5008 CheckAssignmentConstraints(lhsType, rExpr->getType()); 5009 5010 // C99 6.5.16.1p2: The value of the right operand is converted to the 5011 // type of the assignment expression. 5012 // CheckAssignmentConstraints allows the left-hand side to be a reference, 5013 // so that we can use references in built-in functions even in C. 5014 // The getNonReferenceType() call makes sure that the resulting expression 5015 // does not have reference type. 5016 if (result != Incompatible && rExpr->getType() != lhsType) 5017 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), 5018 CK_Unknown); 5019 return result; 5020} 5021 5022QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5023 Diag(Loc, diag::err_typecheck_invalid_operands) 5024 << lex->getType() << rex->getType() 5025 << lex->getSourceRange() << rex->getSourceRange(); 5026 return QualType(); 5027} 5028 5029QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5030 // For conversion purposes, we ignore any qualifiers. 5031 // For example, "const float" and "float" are equivalent. 5032 QualType lhsType = 5033 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 5034 QualType rhsType = 5035 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 5036 5037 // If the vector types are identical, return. 5038 if (lhsType == rhsType) 5039 return lhsType; 5040 5041 // Handle the case of a vector & extvector type of the same size and element 5042 // type. It would be nice if we only had one vector type someday. 5043 if (getLangOptions().LaxVectorConversions) { 5044 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5045 if (const VectorType *RV = rhsType->getAs<VectorType>()) { 5046 if (LV->getElementType() == RV->getElementType() && 5047 LV->getNumElements() == RV->getNumElements()) { 5048 if (lhsType->isExtVectorType()) { 5049 ImpCastExprToType(rex, lhsType, CK_BitCast); 5050 return lhsType; 5051 } 5052 5053 ImpCastExprToType(lex, rhsType, CK_BitCast); 5054 return rhsType; 5055 } else if (Context.getTypeSize(lhsType) ==Context.getTypeSize(rhsType)){ 5056 // If we are allowing lax vector conversions, and LHS and RHS are both 5057 // vectors, the total size only needs to be the same. This is a 5058 // bitcast; no bits are changed but the result type is different. 5059 ImpCastExprToType(rex, lhsType, CK_BitCast); 5060 return lhsType; 5061 } 5062 } 5063 } 5064 } 5065 5066 // Handle the case of equivalent AltiVec and GCC vector types 5067 if (lhsType->isVectorType() && rhsType->isVectorType() && 5068 Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5069 ImpCastExprToType(lex, rhsType, CK_BitCast); 5070 return rhsType; 5071 } 5072 5073 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5074 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5075 bool swapped = false; 5076 if (rhsType->isExtVectorType()) { 5077 swapped = true; 5078 std::swap(rex, lex); 5079 std::swap(rhsType, lhsType); 5080 } 5081 5082 // Handle the case of an ext vector and scalar. 5083 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5084 QualType EltTy = LV->getElementType(); 5085 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5086 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5087 ImpCastExprToType(rex, lhsType, CK_IntegralCast); 5088 if (swapped) std::swap(rex, lex); 5089 return lhsType; 5090 } 5091 } 5092 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5093 rhsType->isRealFloatingType()) { 5094 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5095 ImpCastExprToType(rex, lhsType, CK_FloatingCast); 5096 if (swapped) std::swap(rex, lex); 5097 return lhsType; 5098 } 5099 } 5100 } 5101 5102 // Vectors of different size or scalar and non-ext-vector are errors. 5103 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5104 << lex->getType() << rex->getType() 5105 << lex->getSourceRange() << rex->getSourceRange(); 5106 return QualType(); 5107} 5108 5109QualType Sema::CheckMultiplyDivideOperands( 5110 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5111 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5112 return CheckVectorOperands(Loc, lex, rex); 5113 5114 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5115 5116 if (!lex->getType()->isArithmeticType() || 5117 !rex->getType()->isArithmeticType()) 5118 return InvalidOperands(Loc, lex, rex); 5119 5120 // Check for division by zero. 5121 if (isDiv && 5122 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5123 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5124 << rex->getSourceRange()); 5125 5126 return compType; 5127} 5128 5129QualType Sema::CheckRemainderOperands( 5130 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5131 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5132 if (lex->getType()->hasIntegerRepresentation() && 5133 rex->getType()->hasIntegerRepresentation()) 5134 return CheckVectorOperands(Loc, lex, rex); 5135 return InvalidOperands(Loc, lex, rex); 5136 } 5137 5138 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5139 5140 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5141 return InvalidOperands(Loc, lex, rex); 5142 5143 // Check for remainder by zero. 5144 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5145 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5146 << rex->getSourceRange()); 5147 5148 return compType; 5149} 5150 5151QualType Sema::CheckAdditionOperands( // C99 6.5.6 5152 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5153 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5154 QualType compType = CheckVectorOperands(Loc, lex, rex); 5155 if (CompLHSTy) *CompLHSTy = compType; 5156 return compType; 5157 } 5158 5159 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5160 5161 // handle the common case first (both operands are arithmetic). 5162 if (lex->getType()->isArithmeticType() && 5163 rex->getType()->isArithmeticType()) { 5164 if (CompLHSTy) *CompLHSTy = compType; 5165 return compType; 5166 } 5167 5168 // Put any potential pointer into PExp 5169 Expr* PExp = lex, *IExp = rex; 5170 if (IExp->getType()->isAnyPointerType()) 5171 std::swap(PExp, IExp); 5172 5173 if (PExp->getType()->isAnyPointerType()) { 5174 5175 if (IExp->getType()->isIntegerType()) { 5176 QualType PointeeTy = PExp->getType()->getPointeeType(); 5177 5178 // Check for arithmetic on pointers to incomplete types. 5179 if (PointeeTy->isVoidType()) { 5180 if (getLangOptions().CPlusPlus) { 5181 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5182 << lex->getSourceRange() << rex->getSourceRange(); 5183 return QualType(); 5184 } 5185 5186 // GNU extension: arithmetic on pointer to void 5187 Diag(Loc, diag::ext_gnu_void_ptr) 5188 << lex->getSourceRange() << rex->getSourceRange(); 5189 } else if (PointeeTy->isFunctionType()) { 5190 if (getLangOptions().CPlusPlus) { 5191 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5192 << lex->getType() << lex->getSourceRange(); 5193 return QualType(); 5194 } 5195 5196 // GNU extension: arithmetic on pointer to function 5197 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5198 << lex->getType() << lex->getSourceRange(); 5199 } else { 5200 // Check if we require a complete type. 5201 if (((PExp->getType()->isPointerType() && 5202 !PExp->getType()->isDependentType()) || 5203 PExp->getType()->isObjCObjectPointerType()) && 5204 RequireCompleteType(Loc, PointeeTy, 5205 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5206 << PExp->getSourceRange() 5207 << PExp->getType())) 5208 return QualType(); 5209 } 5210 // Diagnose bad cases where we step over interface counts. 5211 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5212 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5213 << PointeeTy << PExp->getSourceRange(); 5214 return QualType(); 5215 } 5216 5217 if (CompLHSTy) { 5218 QualType LHSTy = Context.isPromotableBitField(lex); 5219 if (LHSTy.isNull()) { 5220 LHSTy = lex->getType(); 5221 if (LHSTy->isPromotableIntegerType()) 5222 LHSTy = Context.getPromotedIntegerType(LHSTy); 5223 } 5224 *CompLHSTy = LHSTy; 5225 } 5226 return PExp->getType(); 5227 } 5228 } 5229 5230 return InvalidOperands(Loc, lex, rex); 5231} 5232 5233// C99 6.5.6 5234QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5235 SourceLocation Loc, QualType* CompLHSTy) { 5236 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5237 QualType compType = CheckVectorOperands(Loc, lex, rex); 5238 if (CompLHSTy) *CompLHSTy = compType; 5239 return compType; 5240 } 5241 5242 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5243 5244 // Enforce type constraints: C99 6.5.6p3. 5245 5246 // Handle the common case first (both operands are arithmetic). 5247 if (lex->getType()->isArithmeticType() 5248 && rex->getType()->isArithmeticType()) { 5249 if (CompLHSTy) *CompLHSTy = compType; 5250 return compType; 5251 } 5252 5253 // Either ptr - int or ptr - ptr. 5254 if (lex->getType()->isAnyPointerType()) { 5255 QualType lpointee = lex->getType()->getPointeeType(); 5256 5257 // The LHS must be an completely-defined object type. 5258 5259 bool ComplainAboutVoid = false; 5260 Expr *ComplainAboutFunc = 0; 5261 if (lpointee->isVoidType()) { 5262 if (getLangOptions().CPlusPlus) { 5263 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5264 << lex->getSourceRange() << rex->getSourceRange(); 5265 return QualType(); 5266 } 5267 5268 // GNU C extension: arithmetic on pointer to void 5269 ComplainAboutVoid = true; 5270 } else if (lpointee->isFunctionType()) { 5271 if (getLangOptions().CPlusPlus) { 5272 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5273 << lex->getType() << lex->getSourceRange(); 5274 return QualType(); 5275 } 5276 5277 // GNU C extension: arithmetic on pointer to function 5278 ComplainAboutFunc = lex; 5279 } else if (!lpointee->isDependentType() && 5280 RequireCompleteType(Loc, lpointee, 5281 PDiag(diag::err_typecheck_sub_ptr_object) 5282 << lex->getSourceRange() 5283 << lex->getType())) 5284 return QualType(); 5285 5286 // Diagnose bad cases where we step over interface counts. 5287 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5288 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5289 << lpointee << lex->getSourceRange(); 5290 return QualType(); 5291 } 5292 5293 // The result type of a pointer-int computation is the pointer type. 5294 if (rex->getType()->isIntegerType()) { 5295 if (ComplainAboutVoid) 5296 Diag(Loc, diag::ext_gnu_void_ptr) 5297 << lex->getSourceRange() << rex->getSourceRange(); 5298 if (ComplainAboutFunc) 5299 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5300 << ComplainAboutFunc->getType() 5301 << ComplainAboutFunc->getSourceRange(); 5302 5303 if (CompLHSTy) *CompLHSTy = lex->getType(); 5304 return lex->getType(); 5305 } 5306 5307 // Handle pointer-pointer subtractions. 5308 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5309 QualType rpointee = RHSPTy->getPointeeType(); 5310 5311 // RHS must be a completely-type object type. 5312 // Handle the GNU void* extension. 5313 if (rpointee->isVoidType()) { 5314 if (getLangOptions().CPlusPlus) { 5315 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5316 << lex->getSourceRange() << rex->getSourceRange(); 5317 return QualType(); 5318 } 5319 5320 ComplainAboutVoid = true; 5321 } else if (rpointee->isFunctionType()) { 5322 if (getLangOptions().CPlusPlus) { 5323 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5324 << rex->getType() << rex->getSourceRange(); 5325 return QualType(); 5326 } 5327 5328 // GNU extension: arithmetic on pointer to function 5329 if (!ComplainAboutFunc) 5330 ComplainAboutFunc = rex; 5331 } else if (!rpointee->isDependentType() && 5332 RequireCompleteType(Loc, rpointee, 5333 PDiag(diag::err_typecheck_sub_ptr_object) 5334 << rex->getSourceRange() 5335 << rex->getType())) 5336 return QualType(); 5337 5338 if (getLangOptions().CPlusPlus) { 5339 // Pointee types must be the same: C++ [expr.add] 5340 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5341 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5342 << lex->getType() << rex->getType() 5343 << lex->getSourceRange() << rex->getSourceRange(); 5344 return QualType(); 5345 } 5346 } else { 5347 // Pointee types must be compatible C99 6.5.6p3 5348 if (!Context.typesAreCompatible( 5349 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5350 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5351 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5352 << lex->getType() << rex->getType() 5353 << lex->getSourceRange() << rex->getSourceRange(); 5354 return QualType(); 5355 } 5356 } 5357 5358 if (ComplainAboutVoid) 5359 Diag(Loc, diag::ext_gnu_void_ptr) 5360 << lex->getSourceRange() << rex->getSourceRange(); 5361 if (ComplainAboutFunc) 5362 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5363 << ComplainAboutFunc->getType() 5364 << ComplainAboutFunc->getSourceRange(); 5365 5366 if (CompLHSTy) *CompLHSTy = lex->getType(); 5367 return Context.getPointerDiffType(); 5368 } 5369 } 5370 5371 return InvalidOperands(Loc, lex, rex); 5372} 5373 5374// C99 6.5.7 5375QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5376 bool isCompAssign) { 5377 // C99 6.5.7p2: Each of the operands shall have integer type. 5378 if (!lex->getType()->hasIntegerRepresentation() || 5379 !rex->getType()->hasIntegerRepresentation()) 5380 return InvalidOperands(Loc, lex, rex); 5381 5382 // Vector shifts promote their scalar inputs to vector type. 5383 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5384 return CheckVectorOperands(Loc, lex, rex); 5385 5386 // Shifts don't perform usual arithmetic conversions, they just do integer 5387 // promotions on each operand. C99 6.5.7p3 5388 QualType LHSTy = Context.isPromotableBitField(lex); 5389 if (LHSTy.isNull()) { 5390 LHSTy = lex->getType(); 5391 if (LHSTy->isPromotableIntegerType()) 5392 LHSTy = Context.getPromotedIntegerType(LHSTy); 5393 } 5394 if (!isCompAssign) 5395 ImpCastExprToType(lex, LHSTy, CK_IntegralCast); 5396 5397 UsualUnaryConversions(rex); 5398 5399 // Sanity-check shift operands 5400 llvm::APSInt Right; 5401 // Check right/shifter operand 5402 if (!rex->isValueDependent() && 5403 rex->isIntegerConstantExpr(Right, Context)) { 5404 if (Right.isNegative()) 5405 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5406 else { 5407 llvm::APInt LeftBits(Right.getBitWidth(), 5408 Context.getTypeSize(lex->getType())); 5409 if (Right.uge(LeftBits)) 5410 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5411 } 5412 } 5413 5414 // "The type of the result is that of the promoted left operand." 5415 return LHSTy; 5416} 5417 5418static bool IsWithinTemplateSpecialization(Decl *D) { 5419 if (DeclContext *DC = D->getDeclContext()) { 5420 if (isa<ClassTemplateSpecializationDecl>(DC)) 5421 return true; 5422 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 5423 return FD->isFunctionTemplateSpecialization(); 5424 } 5425 return false; 5426} 5427 5428// C99 6.5.8, C++ [expr.rel] 5429QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5430 unsigned OpaqueOpc, bool isRelational) { 5431 BinaryOperatorKind Opc = (BinaryOperatorKind) OpaqueOpc; 5432 5433 // Handle vector comparisons separately. 5434 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5435 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5436 5437 QualType lType = lex->getType(); 5438 QualType rType = rex->getType(); 5439 5440 if (!lType->hasFloatingRepresentation() && 5441 !(lType->isBlockPointerType() && isRelational) && 5442 !lex->getLocStart().isMacroID() && 5443 !rex->getLocStart().isMacroID()) { 5444 // For non-floating point types, check for self-comparisons of the form 5445 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5446 // often indicate logic errors in the program. 5447 // 5448 // NOTE: Don't warn about comparison expressions resulting from macro 5449 // expansion. Also don't warn about comparisons which are only self 5450 // comparisons within a template specialization. The warnings should catch 5451 // obvious cases in the definition of the template anyways. The idea is to 5452 // warn when the typed comparison operator will always evaluate to the same 5453 // result. 5454 Expr *LHSStripped = lex->IgnoreParens(); 5455 Expr *RHSStripped = rex->IgnoreParens(); 5456 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 5457 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 5458 if (DRL->getDecl() == DRR->getDecl() && 5459 !IsWithinTemplateSpecialization(DRL->getDecl())) { 5460 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5461 << 0 // self- 5462 << (Opc == BO_EQ 5463 || Opc == BO_LE 5464 || Opc == BO_GE)); 5465 } else if (lType->isArrayType() && rType->isArrayType() && 5466 !DRL->getDecl()->getType()->isReferenceType() && 5467 !DRR->getDecl()->getType()->isReferenceType()) { 5468 // what is it always going to eval to? 5469 char always_evals_to; 5470 switch(Opc) { 5471 case BO_EQ: // e.g. array1 == array2 5472 always_evals_to = 0; // false 5473 break; 5474 case BO_NE: // e.g. array1 != array2 5475 always_evals_to = 1; // true 5476 break; 5477 default: 5478 // best we can say is 'a constant' 5479 always_evals_to = 2; // e.g. array1 <= array2 5480 break; 5481 } 5482 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5483 << 1 // array 5484 << always_evals_to); 5485 } 5486 } 5487 } 5488 5489 if (isa<CastExpr>(LHSStripped)) 5490 LHSStripped = LHSStripped->IgnoreParenCasts(); 5491 if (isa<CastExpr>(RHSStripped)) 5492 RHSStripped = RHSStripped->IgnoreParenCasts(); 5493 5494 // Warn about comparisons against a string constant (unless the other 5495 // operand is null), the user probably wants strcmp. 5496 Expr *literalString = 0; 5497 Expr *literalStringStripped = 0; 5498 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5499 !RHSStripped->isNullPointerConstant(Context, 5500 Expr::NPC_ValueDependentIsNull)) { 5501 literalString = lex; 5502 literalStringStripped = LHSStripped; 5503 } else if ((isa<StringLiteral>(RHSStripped) || 5504 isa<ObjCEncodeExpr>(RHSStripped)) && 5505 !LHSStripped->isNullPointerConstant(Context, 5506 Expr::NPC_ValueDependentIsNull)) { 5507 literalString = rex; 5508 literalStringStripped = RHSStripped; 5509 } 5510 5511 if (literalString) { 5512 std::string resultComparison; 5513 switch (Opc) { 5514 case BO_LT: resultComparison = ") < 0"; break; 5515 case BO_GT: resultComparison = ") > 0"; break; 5516 case BO_LE: resultComparison = ") <= 0"; break; 5517 case BO_GE: resultComparison = ") >= 0"; break; 5518 case BO_EQ: resultComparison = ") == 0"; break; 5519 case BO_NE: resultComparison = ") != 0"; break; 5520 default: assert(false && "Invalid comparison operator"); 5521 } 5522 5523 DiagRuntimeBehavior(Loc, 5524 PDiag(diag::warn_stringcompare) 5525 << isa<ObjCEncodeExpr>(literalStringStripped) 5526 << literalString->getSourceRange()); 5527 } 5528 } 5529 5530 // C99 6.5.8p3 / C99 6.5.9p4 5531 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5532 UsualArithmeticConversions(lex, rex); 5533 else { 5534 UsualUnaryConversions(lex); 5535 UsualUnaryConversions(rex); 5536 } 5537 5538 lType = lex->getType(); 5539 rType = rex->getType(); 5540 5541 // The result of comparisons is 'bool' in C++, 'int' in C. 5542 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5543 5544 if (isRelational) { 5545 if (lType->isRealType() && rType->isRealType()) 5546 return ResultTy; 5547 } else { 5548 // Check for comparisons of floating point operands using != and ==. 5549 if (lType->hasFloatingRepresentation()) 5550 CheckFloatComparison(Loc,lex,rex); 5551 5552 if (lType->isArithmeticType() && rType->isArithmeticType()) 5553 return ResultTy; 5554 } 5555 5556 bool LHSIsNull = lex->isNullPointerConstant(Context, 5557 Expr::NPC_ValueDependentIsNull); 5558 bool RHSIsNull = rex->isNullPointerConstant(Context, 5559 Expr::NPC_ValueDependentIsNull); 5560 5561 // All of the following pointer-related warnings are GCC extensions, except 5562 // when handling null pointer constants. 5563 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5564 QualType LCanPointeeTy = 5565 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5566 QualType RCanPointeeTy = 5567 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5568 5569 if (getLangOptions().CPlusPlus) { 5570 if (LCanPointeeTy == RCanPointeeTy) 5571 return ResultTy; 5572 if (!isRelational && 5573 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5574 // Valid unless comparison between non-null pointer and function pointer 5575 // This is a gcc extension compatibility comparison. 5576 // In a SFINAE context, we treat this as a hard error to maintain 5577 // conformance with the C++ standard. 5578 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5579 && !LHSIsNull && !RHSIsNull) { 5580 Diag(Loc, 5581 isSFINAEContext()? 5582 diag::err_typecheck_comparison_of_fptr_to_void 5583 : diag::ext_typecheck_comparison_of_fptr_to_void) 5584 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5585 5586 if (isSFINAEContext()) 5587 return QualType(); 5588 5589 ImpCastExprToType(rex, lType, CK_BitCast); 5590 return ResultTy; 5591 } 5592 } 5593 // C++ [expr.rel]p2: 5594 // [...] Pointer conversions (4.10) and qualification 5595 // conversions (4.4) are performed on pointer operands (or on 5596 // a pointer operand and a null pointer constant) to bring 5597 // them to their composite pointer type. [...] 5598 // 5599 // C++ [expr.eq]p1 uses the same notion for (in)equality 5600 // comparisons of pointers. 5601 bool NonStandardCompositeType = false; 5602 QualType T = FindCompositePointerType(Loc, lex, rex, 5603 isSFINAEContext()? 0 : &NonStandardCompositeType); 5604 if (T.isNull()) { 5605 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5606 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5607 return QualType(); 5608 } else if (NonStandardCompositeType) { 5609 Diag(Loc, 5610 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5611 << lType << rType << T 5612 << lex->getSourceRange() << rex->getSourceRange(); 5613 } 5614 5615 ImpCastExprToType(lex, T, CK_BitCast); 5616 ImpCastExprToType(rex, T, CK_BitCast); 5617 return ResultTy; 5618 } 5619 // C99 6.5.9p2 and C99 6.5.8p2 5620 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5621 RCanPointeeTy.getUnqualifiedType())) { 5622 // Valid unless a relational comparison of function pointers 5623 if (isRelational && LCanPointeeTy->isFunctionType()) { 5624 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5625 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5626 } 5627 } else if (!isRelational && 5628 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5629 // Valid unless comparison between non-null pointer and function pointer 5630 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5631 && !LHSIsNull && !RHSIsNull) { 5632 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5633 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5634 } 5635 } else { 5636 // Invalid 5637 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5638 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5639 } 5640 if (LCanPointeeTy != RCanPointeeTy) 5641 ImpCastExprToType(rex, lType, CK_BitCast); 5642 return ResultTy; 5643 } 5644 5645 if (getLangOptions().CPlusPlus) { 5646 // Comparison of pointers with null pointer constants and equality 5647 // comparisons of member pointers to null pointer constants. 5648 if (RHSIsNull && 5649 (lType->isPointerType() || 5650 (!isRelational && lType->isMemberPointerType()))) { 5651 ImpCastExprToType(rex, lType, 5652 lType->isMemberPointerType() 5653 ? CK_NullToMemberPointer 5654 : CK_IntegralToPointer); 5655 return ResultTy; 5656 } 5657 if (LHSIsNull && 5658 (rType->isPointerType() || 5659 (!isRelational && rType->isMemberPointerType()))) { 5660 ImpCastExprToType(lex, rType, 5661 rType->isMemberPointerType() 5662 ? CK_NullToMemberPointer 5663 : CK_IntegralToPointer); 5664 return ResultTy; 5665 } 5666 5667 // Comparison of member pointers. 5668 if (!isRelational && 5669 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5670 // C++ [expr.eq]p2: 5671 // In addition, pointers to members can be compared, or a pointer to 5672 // member and a null pointer constant. Pointer to member conversions 5673 // (4.11) and qualification conversions (4.4) are performed to bring 5674 // them to a common type. If one operand is a null pointer constant, 5675 // the common type is the type of the other operand. Otherwise, the 5676 // common type is a pointer to member type similar (4.4) to the type 5677 // of one of the operands, with a cv-qualification signature (4.4) 5678 // that is the union of the cv-qualification signatures of the operand 5679 // types. 5680 bool NonStandardCompositeType = false; 5681 QualType T = FindCompositePointerType(Loc, lex, rex, 5682 isSFINAEContext()? 0 : &NonStandardCompositeType); 5683 if (T.isNull()) { 5684 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5685 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5686 return QualType(); 5687 } else if (NonStandardCompositeType) { 5688 Diag(Loc, 5689 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5690 << lType << rType << T 5691 << lex->getSourceRange() << rex->getSourceRange(); 5692 } 5693 5694 ImpCastExprToType(lex, T, CK_BitCast); 5695 ImpCastExprToType(rex, T, CK_BitCast); 5696 return ResultTy; 5697 } 5698 5699 // Comparison of nullptr_t with itself. 5700 if (lType->isNullPtrType() && rType->isNullPtrType()) 5701 return ResultTy; 5702 } 5703 5704 // Handle block pointer types. 5705 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5706 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5707 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5708 5709 if (!LHSIsNull && !RHSIsNull && 5710 !Context.typesAreCompatible(lpointee, rpointee)) { 5711 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5712 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5713 } 5714 ImpCastExprToType(rex, lType, CK_BitCast); 5715 return ResultTy; 5716 } 5717 // Allow block pointers to be compared with null pointer constants. 5718 if (!isRelational 5719 && ((lType->isBlockPointerType() && rType->isPointerType()) 5720 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5721 if (!LHSIsNull && !RHSIsNull) { 5722 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5723 ->getPointeeType()->isVoidType()) 5724 || (lType->isPointerType() && lType->getAs<PointerType>() 5725 ->getPointeeType()->isVoidType()))) 5726 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5727 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5728 } 5729 ImpCastExprToType(rex, lType, CK_BitCast); 5730 return ResultTy; 5731 } 5732 5733 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5734 if (lType->isPointerType() || rType->isPointerType()) { 5735 const PointerType *LPT = lType->getAs<PointerType>(); 5736 const PointerType *RPT = rType->getAs<PointerType>(); 5737 bool LPtrToVoid = LPT ? 5738 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5739 bool RPtrToVoid = RPT ? 5740 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5741 5742 if (!LPtrToVoid && !RPtrToVoid && 5743 !Context.typesAreCompatible(lType, rType)) { 5744 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5745 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5746 } 5747 ImpCastExprToType(rex, lType, CK_BitCast); 5748 return ResultTy; 5749 } 5750 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5751 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5752 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5753 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5754 ImpCastExprToType(rex, lType, CK_BitCast); 5755 return ResultTy; 5756 } 5757 } 5758 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 5759 (lType->isIntegerType() && rType->isAnyPointerType())) { 5760 unsigned DiagID = 0; 5761 bool isError = false; 5762 if ((LHSIsNull && lType->isIntegerType()) || 5763 (RHSIsNull && rType->isIntegerType())) { 5764 if (isRelational && !getLangOptions().CPlusPlus) 5765 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5766 } else if (isRelational && !getLangOptions().CPlusPlus) 5767 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5768 else if (getLangOptions().CPlusPlus) { 5769 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 5770 isError = true; 5771 } else 5772 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5773 5774 if (DiagID) { 5775 Diag(Loc, DiagID) 5776 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5777 if (isError) 5778 return QualType(); 5779 } 5780 5781 if (lType->isIntegerType()) 5782 ImpCastExprToType(lex, rType, CK_IntegralToPointer); 5783 else 5784 ImpCastExprToType(rex, lType, CK_IntegralToPointer); 5785 return ResultTy; 5786 } 5787 5788 // Handle block pointers. 5789 if (!isRelational && RHSIsNull 5790 && lType->isBlockPointerType() && rType->isIntegerType()) { 5791 ImpCastExprToType(rex, lType, CK_IntegralToPointer); 5792 return ResultTy; 5793 } 5794 if (!isRelational && LHSIsNull 5795 && lType->isIntegerType() && rType->isBlockPointerType()) { 5796 ImpCastExprToType(lex, rType, CK_IntegralToPointer); 5797 return ResultTy; 5798 } 5799 return InvalidOperands(Loc, lex, rex); 5800} 5801 5802/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5803/// operates on extended vector types. Instead of producing an IntTy result, 5804/// like a scalar comparison, a vector comparison produces a vector of integer 5805/// types. 5806QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5807 SourceLocation Loc, 5808 bool isRelational) { 5809 // Check to make sure we're operating on vectors of the same type and width, 5810 // Allowing one side to be a scalar of element type. 5811 QualType vType = CheckVectorOperands(Loc, lex, rex); 5812 if (vType.isNull()) 5813 return vType; 5814 5815 QualType lType = lex->getType(); 5816 QualType rType = rex->getType(); 5817 5818 // For non-floating point types, check for self-comparisons of the form 5819 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5820 // often indicate logic errors in the program. 5821 if (!lType->hasFloatingRepresentation()) { 5822 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5823 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5824 if (DRL->getDecl() == DRR->getDecl()) 5825 DiagRuntimeBehavior(Loc, 5826 PDiag(diag::warn_comparison_always) 5827 << 0 // self- 5828 << 2 // "a constant" 5829 ); 5830 } 5831 5832 // Check for comparisons of floating point operands using != and ==. 5833 if (!isRelational && lType->hasFloatingRepresentation()) { 5834 assert (rType->hasFloatingRepresentation()); 5835 CheckFloatComparison(Loc,lex,rex); 5836 } 5837 5838 // Return the type for the comparison, which is the same as vector type for 5839 // integer vectors, or an integer type of identical size and number of 5840 // elements for floating point vectors. 5841 if (lType->hasIntegerRepresentation()) 5842 return lType; 5843 5844 const VectorType *VTy = lType->getAs<VectorType>(); 5845 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5846 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5847 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5848 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5849 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5850 5851 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5852 "Unhandled vector element size in vector compare"); 5853 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5854} 5855 5856inline QualType Sema::CheckBitwiseOperands( 5857 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5858 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5859 if (lex->getType()->hasIntegerRepresentation() && 5860 rex->getType()->hasIntegerRepresentation()) 5861 return CheckVectorOperands(Loc, lex, rex); 5862 5863 return InvalidOperands(Loc, lex, rex); 5864 } 5865 5866 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5867 5868 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5869 return compType; 5870 return InvalidOperands(Loc, lex, rex); 5871} 5872 5873inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5874 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 5875 5876 // Diagnose cases where the user write a logical and/or but probably meant a 5877 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 5878 // is a constant. 5879 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 5880 rex->getType()->isIntegerType() && !rex->isValueDependent() && 5881 // Don't warn in macros. 5882 !Loc.isMacroID()) { 5883 // If the RHS can be constant folded, and if it constant folds to something 5884 // that isn't 0 or 1 (which indicate a potential logical operation that 5885 // happened to fold to true/false) then warn. 5886 Expr::EvalResult Result; 5887 if (rex->Evaluate(Result, Context) && !Result.HasSideEffects && 5888 Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { 5889 Diag(Loc, diag::warn_logical_instead_of_bitwise) 5890 << rex->getSourceRange() 5891 << (Opc == BO_LAnd ? "&&" : "||") 5892 << (Opc == BO_LAnd ? "&" : "|"); 5893 } 5894 } 5895 5896 if (!Context.getLangOptions().CPlusPlus) { 5897 UsualUnaryConversions(lex); 5898 UsualUnaryConversions(rex); 5899 5900 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5901 return InvalidOperands(Loc, lex, rex); 5902 5903 return Context.IntTy; 5904 } 5905 5906 // The following is safe because we only use this method for 5907 // non-overloadable operands. 5908 5909 // C++ [expr.log.and]p1 5910 // C++ [expr.log.or]p1 5911 // The operands are both contextually converted to type bool. 5912 if (PerformContextuallyConvertToBool(lex) || 5913 PerformContextuallyConvertToBool(rex)) 5914 return InvalidOperands(Loc, lex, rex); 5915 5916 // C++ [expr.log.and]p2 5917 // C++ [expr.log.or]p2 5918 // The result is a bool. 5919 return Context.BoolTy; 5920} 5921 5922/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5923/// is a read-only property; return true if so. A readonly property expression 5924/// depends on various declarations and thus must be treated specially. 5925/// 5926static bool IsReadonlyProperty(Expr *E, Sema &S) { 5927 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5928 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5929 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5930 QualType BaseType = PropExpr->getBase()->getType(); 5931 if (const ObjCObjectPointerType *OPT = 5932 BaseType->getAsObjCInterfacePointerType()) 5933 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5934 if (S.isPropertyReadonly(PDecl, IFace)) 5935 return true; 5936 } 5937 } 5938 return false; 5939} 5940 5941/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5942/// emit an error and return true. If so, return false. 5943static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5944 SourceLocation OrigLoc = Loc; 5945 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5946 &Loc); 5947 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5948 IsLV = Expr::MLV_ReadonlyProperty; 5949 if (IsLV == Expr::MLV_Valid) 5950 return false; 5951 5952 unsigned Diag = 0; 5953 bool NeedType = false; 5954 switch (IsLV) { // C99 6.5.16p2 5955 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5956 case Expr::MLV_ArrayType: 5957 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5958 NeedType = true; 5959 break; 5960 case Expr::MLV_NotObjectType: 5961 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5962 NeedType = true; 5963 break; 5964 case Expr::MLV_LValueCast: 5965 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5966 break; 5967 case Expr::MLV_Valid: 5968 llvm_unreachable("did not take early return for MLV_Valid"); 5969 case Expr::MLV_InvalidExpression: 5970 case Expr::MLV_MemberFunction: 5971 case Expr::MLV_ClassTemporary: 5972 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5973 break; 5974 case Expr::MLV_IncompleteType: 5975 case Expr::MLV_IncompleteVoidType: 5976 return S.RequireCompleteType(Loc, E->getType(), 5977 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5978 << E->getSourceRange()); 5979 case Expr::MLV_DuplicateVectorComponents: 5980 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5981 break; 5982 case Expr::MLV_NotBlockQualified: 5983 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5984 break; 5985 case Expr::MLV_ReadonlyProperty: 5986 Diag = diag::error_readonly_property_assignment; 5987 break; 5988 case Expr::MLV_NoSetterProperty: 5989 Diag = diag::error_nosetter_property_assignment; 5990 break; 5991 case Expr::MLV_SubObjCPropertySetting: 5992 Diag = diag::error_no_subobject_property_setting; 5993 break; 5994 } 5995 5996 SourceRange Assign; 5997 if (Loc != OrigLoc) 5998 Assign = SourceRange(OrigLoc, OrigLoc); 5999 if (NeedType) 6000 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 6001 else 6002 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 6003 return true; 6004} 6005 6006 6007 6008// C99 6.5.16.1 6009QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 6010 SourceLocation Loc, 6011 QualType CompoundType) { 6012 // Verify that LHS is a modifiable lvalue, and emit error if not. 6013 if (CheckForModifiableLvalue(LHS, Loc, *this)) 6014 return QualType(); 6015 6016 QualType LHSType = LHS->getType(); 6017 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 6018 AssignConvertType ConvTy; 6019 if (CompoundType.isNull()) { 6020 QualType LHSTy(LHSType); 6021 // Simple assignment "x = y". 6022 ConvertPropertyAssignment(LHS, RHS, LHSTy); 6023 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 6024 // Special case of NSObject attributes on c-style pointer types. 6025 if (ConvTy == IncompatiblePointer && 6026 ((Context.isObjCNSObjectType(LHSType) && 6027 RHSType->isObjCObjectPointerType()) || 6028 (Context.isObjCNSObjectType(RHSType) && 6029 LHSType->isObjCObjectPointerType()))) 6030 ConvTy = Compatible; 6031 6032 // If the RHS is a unary plus or minus, check to see if they = and + are 6033 // right next to each other. If so, the user may have typo'd "x =+ 4" 6034 // instead of "x += 4". 6035 Expr *RHSCheck = RHS; 6036 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 6037 RHSCheck = ICE->getSubExpr(); 6038 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 6039 if ((UO->getOpcode() == UO_Plus || 6040 UO->getOpcode() == UO_Minus) && 6041 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 6042 // Only if the two operators are exactly adjacent. 6043 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 6044 // And there is a space or other character before the subexpr of the 6045 // unary +/-. We don't want to warn on "x=-1". 6046 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 6047 UO->getSubExpr()->getLocStart().isFileID()) { 6048 Diag(Loc, diag::warn_not_compound_assign) 6049 << (UO->getOpcode() == UO_Plus ? "+" : "-") 6050 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 6051 } 6052 } 6053 } else { 6054 // Compound assignment "x += y" 6055 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 6056 } 6057 6058 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 6059 RHS, AA_Assigning)) 6060 return QualType(); 6061 6062 6063 // Check to see if the destination operand is a dereferenced null pointer. If 6064 // so, and if not volatile-qualified, this is undefined behavior that the 6065 // optimizer will delete, so warn about it. People sometimes try to use this 6066 // to get a deterministic trap and are surprised by clang's behavior. This 6067 // only handles the pattern "*null = whatever", which is a very syntactic 6068 // check. 6069 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 6070 if (UO->getOpcode() == UO_Deref && 6071 UO->getSubExpr()->IgnoreParenCasts()-> 6072 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 6073 !UO->getType().isVolatileQualified()) { 6074 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 6075 << UO->getSubExpr()->getSourceRange(); 6076 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 6077 } 6078 6079 // C99 6.5.16p3: The type of an assignment expression is the type of the 6080 // left operand unless the left operand has qualified type, in which case 6081 // it is the unqualified version of the type of the left operand. 6082 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 6083 // is converted to the type of the assignment expression (above). 6084 // C++ 5.17p1: the type of the assignment expression is that of its left 6085 // operand. 6086 return LHSType.getUnqualifiedType(); 6087} 6088 6089// C99 6.5.17 6090QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 6091 DiagnoseUnusedExprResult(LHS); 6092 6093 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 6094 // C++ does not perform this conversion (C++ [expr.comma]p1). 6095 if (!getLangOptions().CPlusPlus) 6096 DefaultFunctionArrayLvalueConversion(RHS); 6097 6098 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 6099 // incomplete in C++). 6100 6101 return RHS->getType(); 6102} 6103 6104/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 6105/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 6106QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 6107 bool isInc, bool isPrefix) { 6108 if (Op->isTypeDependent()) 6109 return Context.DependentTy; 6110 6111 QualType ResType = Op->getType(); 6112 assert(!ResType.isNull() && "no type for increment/decrement expression"); 6113 6114 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 6115 // Decrement of bool is not allowed. 6116 if (!isInc) { 6117 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 6118 return QualType(); 6119 } 6120 // Increment of bool sets it to true, but is deprecated. 6121 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 6122 } else if (ResType->isRealType()) { 6123 // OK! 6124 } else if (ResType->isAnyPointerType()) { 6125 QualType PointeeTy = ResType->getPointeeType(); 6126 6127 // C99 6.5.2.4p2, 6.5.6p2 6128 if (PointeeTy->isVoidType()) { 6129 if (getLangOptions().CPlusPlus) { 6130 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 6131 << Op->getSourceRange(); 6132 return QualType(); 6133 } 6134 6135 // Pointer to void is a GNU extension in C. 6136 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 6137 } else if (PointeeTy->isFunctionType()) { 6138 if (getLangOptions().CPlusPlus) { 6139 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 6140 << Op->getType() << Op->getSourceRange(); 6141 return QualType(); 6142 } 6143 6144 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 6145 << ResType << Op->getSourceRange(); 6146 } else if (RequireCompleteType(OpLoc, PointeeTy, 6147 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6148 << Op->getSourceRange() 6149 << ResType)) 6150 return QualType(); 6151 // Diagnose bad cases where we step over interface counts. 6152 else if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6153 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6154 << PointeeTy << Op->getSourceRange(); 6155 return QualType(); 6156 } 6157 } else if (ResType->isAnyComplexType()) { 6158 // C99 does not support ++/-- on complex types, we allow as an extension. 6159 Diag(OpLoc, diag::ext_integer_increment_complex) 6160 << ResType << Op->getSourceRange(); 6161 } else { 6162 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6163 << ResType << int(isInc) << Op->getSourceRange(); 6164 return QualType(); 6165 } 6166 // At this point, we know we have a real, complex or pointer type. 6167 // Now make sure the operand is a modifiable lvalue. 6168 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6169 return QualType(); 6170 // In C++, a prefix increment is the same type as the operand. Otherwise 6171 // (in C or with postfix), the increment is the unqualified type of the 6172 // operand. 6173 return isPrefix && getLangOptions().CPlusPlus 6174 ? ResType : ResType.getUnqualifiedType(); 6175} 6176 6177void Sema::ConvertPropertyAssignment(Expr *LHS, Expr *&RHS, QualType& LHSTy) { 6178 bool copyInit = false; 6179 if (const ObjCImplicitSetterGetterRefExpr *OISGE = 6180 dyn_cast<ObjCImplicitSetterGetterRefExpr>(LHS)) { 6181 // If using property-dot syntax notation for assignment, and there is a 6182 // setter, RHS expression is being passed to the setter argument. So, 6183 // type conversion (and comparison) is RHS to setter's argument type. 6184 if (const ObjCMethodDecl *SetterMD = OISGE->getSetterMethod()) { 6185 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 6186 LHSTy = (*P)->getType(); 6187 } 6188 copyInit = (getLangOptions().CPlusPlus && LHSTy->isRecordType()); 6189 } 6190 else 6191 copyInit = (getLangOptions().CPlusPlus && isa<ObjCPropertyRefExpr>(LHS) && 6192 LHSTy->isRecordType()); 6193 if (copyInit) { 6194 InitializedEntity Entity = 6195 InitializedEntity::InitializeParameter(LHSTy); 6196 Expr *Arg = RHS; 6197 ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), 6198 Owned(Arg)); 6199 if (!ArgE.isInvalid()) 6200 RHS = ArgE.takeAs<Expr>(); 6201 } 6202} 6203 6204 6205/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6206/// This routine allows us to typecheck complex/recursive expressions 6207/// where the declaration is needed for type checking. We only need to 6208/// handle cases when the expression references a function designator 6209/// or is an lvalue. Here are some examples: 6210/// - &(x) => x 6211/// - &*****f => f for f a function designator. 6212/// - &s.xx => s 6213/// - &s.zz[1].yy -> s, if zz is an array 6214/// - *(x + 1) -> x, if x is an array 6215/// - &"123"[2] -> 0 6216/// - & __real__ x -> x 6217static NamedDecl *getPrimaryDecl(Expr *E) { 6218 switch (E->getStmtClass()) { 6219 case Stmt::DeclRefExprClass: 6220 return cast<DeclRefExpr>(E)->getDecl(); 6221 case Stmt::MemberExprClass: 6222 // If this is an arrow operator, the address is an offset from 6223 // the base's value, so the object the base refers to is 6224 // irrelevant. 6225 if (cast<MemberExpr>(E)->isArrow()) 6226 return 0; 6227 // Otherwise, the expression refers to a part of the base 6228 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6229 case Stmt::ArraySubscriptExprClass: { 6230 // FIXME: This code shouldn't be necessary! We should catch the implicit 6231 // promotion of register arrays earlier. 6232 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6233 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6234 if (ICE->getSubExpr()->getType()->isArrayType()) 6235 return getPrimaryDecl(ICE->getSubExpr()); 6236 } 6237 return 0; 6238 } 6239 case Stmt::UnaryOperatorClass: { 6240 UnaryOperator *UO = cast<UnaryOperator>(E); 6241 6242 switch(UO->getOpcode()) { 6243 case UO_Real: 6244 case UO_Imag: 6245 case UO_Extension: 6246 return getPrimaryDecl(UO->getSubExpr()); 6247 default: 6248 return 0; 6249 } 6250 } 6251 case Stmt::ParenExprClass: 6252 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6253 case Stmt::ImplicitCastExprClass: 6254 // If the result of an implicit cast is an l-value, we care about 6255 // the sub-expression; otherwise, the result here doesn't matter. 6256 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6257 default: 6258 return 0; 6259 } 6260} 6261 6262/// CheckAddressOfOperand - The operand of & must be either a function 6263/// designator or an lvalue designating an object. If it is an lvalue, the 6264/// object cannot be declared with storage class register or be a bit field. 6265/// Note: The usual conversions are *not* applied to the operand of the & 6266/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6267/// In C++, the operand might be an overloaded function name, in which case 6268/// we allow the '&' but retain the overloaded-function type. 6269QualType Sema::CheckAddressOfOperand(Expr *OrigOp, SourceLocation OpLoc) { 6270 if (OrigOp->isTypeDependent()) 6271 return Context.DependentTy; 6272 if (OrigOp->getType() == Context.OverloadTy) 6273 return Context.OverloadTy; 6274 6275 // Make sure to ignore parentheses in subsequent checks 6276 Expr *op = OrigOp->IgnoreParens(); 6277 6278 if (getLangOptions().C99) { 6279 // Implement C99-only parts of addressof rules. 6280 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6281 if (uOp->getOpcode() == UO_Deref) 6282 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6283 // (assuming the deref expression is valid). 6284 return uOp->getSubExpr()->getType(); 6285 } 6286 // Technically, there should be a check for array subscript 6287 // expressions here, but the result of one is always an lvalue anyway. 6288 } 6289 NamedDecl *dcl = getPrimaryDecl(op); 6290 Expr::isLvalueResult lval = op->isLvalue(Context); 6291 6292 if (lval == Expr::LV_ClassTemporary) { 6293 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6294 : diag::ext_typecheck_addrof_class_temporary) 6295 << op->getType() << op->getSourceRange(); 6296 if (isSFINAEContext()) 6297 return QualType(); 6298 } else if (isa<ObjCSelectorExpr>(op)) { 6299 return Context.getPointerType(op->getType()); 6300 } else if (lval == Expr::LV_MemberFunction) { 6301 // If it's an instance method, make a member pointer. 6302 // The expression must have exactly the form &A::foo. 6303 6304 // If the underlying expression isn't a decl ref, give up. 6305 if (!isa<DeclRefExpr>(op)) { 6306 Diag(OpLoc, diag::err_invalid_form_pointer_member_function) 6307 << OrigOp->getSourceRange(); 6308 return QualType(); 6309 } 6310 DeclRefExpr *DRE = cast<DeclRefExpr>(op); 6311 CXXMethodDecl *MD = cast<CXXMethodDecl>(DRE->getDecl()); 6312 6313 // The id-expression was parenthesized. 6314 if (OrigOp != DRE) { 6315 Diag(OpLoc, diag::err_parens_pointer_member_function) 6316 << OrigOp->getSourceRange(); 6317 6318 // The method was named without a qualifier. 6319 } else if (!DRE->getQualifier()) { 6320 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6321 << op->getSourceRange(); 6322 } 6323 6324 return Context.getMemberPointerType(op->getType(), 6325 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6326 } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6327 // C99 6.5.3.2p1 6328 // The operand must be either an l-value or a function designator 6329 if (!op->getType()->isFunctionType()) { 6330 // FIXME: emit more specific diag... 6331 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6332 << op->getSourceRange(); 6333 return QualType(); 6334 } 6335 } else if (op->getBitField()) { // C99 6.5.3.2p1 6336 // The operand cannot be a bit-field 6337 Diag(OpLoc, diag::err_typecheck_address_of) 6338 << "bit-field" << op->getSourceRange(); 6339 return QualType(); 6340 } else if (op->refersToVectorElement()) { 6341 // The operand cannot be an element of a vector 6342 Diag(OpLoc, diag::err_typecheck_address_of) 6343 << "vector element" << op->getSourceRange(); 6344 return QualType(); 6345 } else if (isa<ObjCPropertyRefExpr>(op)) { 6346 // cannot take address of a property expression. 6347 Diag(OpLoc, diag::err_typecheck_address_of) 6348 << "property expression" << op->getSourceRange(); 6349 return QualType(); 6350 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6351 // FIXME: Can LHS ever be null here? 6352 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6353 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6354 } else if (dcl) { // C99 6.5.3.2p1 6355 // We have an lvalue with a decl. Make sure the decl is not declared 6356 // with the register storage-class specifier. 6357 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6358 // in C++ it is not error to take address of a register 6359 // variable (c++03 7.1.1P3) 6360 if (vd->getStorageClass() == SC_Register && 6361 !getLangOptions().CPlusPlus) { 6362 Diag(OpLoc, diag::err_typecheck_address_of) 6363 << "register variable" << op->getSourceRange(); 6364 return QualType(); 6365 } 6366 } else if (isa<FunctionTemplateDecl>(dcl)) { 6367 return Context.OverloadTy; 6368 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6369 // Okay: we can take the address of a field. 6370 // Could be a pointer to member, though, if there is an explicit 6371 // scope qualifier for the class. 6372 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6373 DeclContext *Ctx = dcl->getDeclContext(); 6374 if (Ctx && Ctx->isRecord()) { 6375 if (FD->getType()->isReferenceType()) { 6376 Diag(OpLoc, 6377 diag::err_cannot_form_pointer_to_member_of_reference_type) 6378 << FD->getDeclName() << FD->getType(); 6379 return QualType(); 6380 } 6381 6382 return Context.getMemberPointerType(op->getType(), 6383 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6384 } 6385 } 6386 } else if (!isa<FunctionDecl>(dcl)) 6387 assert(0 && "Unknown/unexpected decl type"); 6388 } 6389 6390 if (lval == Expr::LV_IncompleteVoidType) { 6391 // Taking the address of a void variable is technically illegal, but we 6392 // allow it in cases which are otherwise valid. 6393 // Example: "extern void x; void* y = &x;". 6394 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6395 } 6396 6397 // If the operand has type "type", the result has type "pointer to type". 6398 if (op->getType()->isObjCObjectType()) 6399 return Context.getObjCObjectPointerType(op->getType()); 6400 return Context.getPointerType(op->getType()); 6401} 6402 6403/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 6404QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6405 if (Op->isTypeDependent()) 6406 return Context.DependentTy; 6407 6408 UsualUnaryConversions(Op); 6409 QualType OpTy = Op->getType(); 6410 QualType Result; 6411 6412 // Note that per both C89 and C99, indirection is always legal, even if OpTy 6413 // is an incomplete type or void. It would be possible to warn about 6414 // dereferencing a void pointer, but it's completely well-defined, and such a 6415 // warning is unlikely to catch any mistakes. 6416 if (const PointerType *PT = OpTy->getAs<PointerType>()) 6417 Result = PT->getPointeeType(); 6418 else if (const ObjCObjectPointerType *OPT = 6419 OpTy->getAs<ObjCObjectPointerType>()) 6420 Result = OPT->getPointeeType(); 6421 6422 if (Result.isNull()) { 6423 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6424 << OpTy << Op->getSourceRange(); 6425 return QualType(); 6426 } 6427 6428 return Result; 6429} 6430 6431static inline BinaryOperatorKind ConvertTokenKindToBinaryOpcode( 6432 tok::TokenKind Kind) { 6433 BinaryOperatorKind Opc; 6434 switch (Kind) { 6435 default: assert(0 && "Unknown binop!"); 6436 case tok::periodstar: Opc = BO_PtrMemD; break; 6437 case tok::arrowstar: Opc = BO_PtrMemI; break; 6438 case tok::star: Opc = BO_Mul; break; 6439 case tok::slash: Opc = BO_Div; break; 6440 case tok::percent: Opc = BO_Rem; break; 6441 case tok::plus: Opc = BO_Add; break; 6442 case tok::minus: Opc = BO_Sub; break; 6443 case tok::lessless: Opc = BO_Shl; break; 6444 case tok::greatergreater: Opc = BO_Shr; break; 6445 case tok::lessequal: Opc = BO_LE; break; 6446 case tok::less: Opc = BO_LT; break; 6447 case tok::greaterequal: Opc = BO_GE; break; 6448 case tok::greater: Opc = BO_GT; break; 6449 case tok::exclaimequal: Opc = BO_NE; break; 6450 case tok::equalequal: Opc = BO_EQ; break; 6451 case tok::amp: Opc = BO_And; break; 6452 case tok::caret: Opc = BO_Xor; break; 6453 case tok::pipe: Opc = BO_Or; break; 6454 case tok::ampamp: Opc = BO_LAnd; break; 6455 case tok::pipepipe: Opc = BO_LOr; break; 6456 case tok::equal: Opc = BO_Assign; break; 6457 case tok::starequal: Opc = BO_MulAssign; break; 6458 case tok::slashequal: Opc = BO_DivAssign; break; 6459 case tok::percentequal: Opc = BO_RemAssign; break; 6460 case tok::plusequal: Opc = BO_AddAssign; break; 6461 case tok::minusequal: Opc = BO_SubAssign; break; 6462 case tok::lesslessequal: Opc = BO_ShlAssign; break; 6463 case tok::greatergreaterequal: Opc = BO_ShrAssign; break; 6464 case tok::ampequal: Opc = BO_AndAssign; break; 6465 case tok::caretequal: Opc = BO_XorAssign; break; 6466 case tok::pipeequal: Opc = BO_OrAssign; break; 6467 case tok::comma: Opc = BO_Comma; break; 6468 } 6469 return Opc; 6470} 6471 6472static inline UnaryOperatorKind ConvertTokenKindToUnaryOpcode( 6473 tok::TokenKind Kind) { 6474 UnaryOperatorKind Opc; 6475 switch (Kind) { 6476 default: assert(0 && "Unknown unary op!"); 6477 case tok::plusplus: Opc = UO_PreInc; break; 6478 case tok::minusminus: Opc = UO_PreDec; break; 6479 case tok::amp: Opc = UO_AddrOf; break; 6480 case tok::star: Opc = UO_Deref; break; 6481 case tok::plus: Opc = UO_Plus; break; 6482 case tok::minus: Opc = UO_Minus; break; 6483 case tok::tilde: Opc = UO_Not; break; 6484 case tok::exclaim: Opc = UO_LNot; break; 6485 case tok::kw___real: Opc = UO_Real; break; 6486 case tok::kw___imag: Opc = UO_Imag; break; 6487 case tok::kw___extension__: Opc = UO_Extension; break; 6488 } 6489 return Opc; 6490} 6491 6492/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6493/// operator @p Opc at location @c TokLoc. This routine only supports 6494/// built-in operations; ActOnBinOp handles overloaded operators. 6495ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6496 unsigned Op, 6497 Expr *lhs, Expr *rhs) { 6498 QualType ResultTy; // Result type of the binary operator. 6499 BinaryOperatorKind Opc = (BinaryOperatorKind) Op; 6500 // The following two variables are used for compound assignment operators 6501 QualType CompLHSTy; // Type of LHS after promotions for computation 6502 QualType CompResultTy; // Type of computation result 6503 6504 switch (Opc) { 6505 case BO_Assign: 6506 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6507 break; 6508 case BO_PtrMemD: 6509 case BO_PtrMemI: 6510 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6511 Opc == BO_PtrMemI); 6512 break; 6513 case BO_Mul: 6514 case BO_Div: 6515 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6516 Opc == BO_Div); 6517 break; 6518 case BO_Rem: 6519 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6520 break; 6521 case BO_Add: 6522 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6523 break; 6524 case BO_Sub: 6525 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6526 break; 6527 case BO_Shl: 6528 case BO_Shr: 6529 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6530 break; 6531 case BO_LE: 6532 case BO_LT: 6533 case BO_GE: 6534 case BO_GT: 6535 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6536 break; 6537 case BO_EQ: 6538 case BO_NE: 6539 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6540 break; 6541 case BO_And: 6542 case BO_Xor: 6543 case BO_Or: 6544 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6545 break; 6546 case BO_LAnd: 6547 case BO_LOr: 6548 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 6549 break; 6550 case BO_MulAssign: 6551 case BO_DivAssign: 6552 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6553 Opc == BO_DivAssign); 6554 CompLHSTy = CompResultTy; 6555 if (!CompResultTy.isNull()) 6556 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6557 break; 6558 case BO_RemAssign: 6559 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6560 CompLHSTy = CompResultTy; 6561 if (!CompResultTy.isNull()) 6562 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6563 break; 6564 case BO_AddAssign: 6565 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6566 if (!CompResultTy.isNull()) 6567 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6568 break; 6569 case BO_SubAssign: 6570 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6571 if (!CompResultTy.isNull()) 6572 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6573 break; 6574 case BO_ShlAssign: 6575 case BO_ShrAssign: 6576 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6577 CompLHSTy = CompResultTy; 6578 if (!CompResultTy.isNull()) 6579 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6580 break; 6581 case BO_AndAssign: 6582 case BO_XorAssign: 6583 case BO_OrAssign: 6584 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6585 CompLHSTy = CompResultTy; 6586 if (!CompResultTy.isNull()) 6587 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6588 break; 6589 case BO_Comma: 6590 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6591 break; 6592 } 6593 if (ResultTy.isNull()) 6594 return ExprError(); 6595 if (ResultTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6596 if (Opc >= BO_Assign && Opc <= BO_OrAssign) 6597 Diag(OpLoc, diag::err_assignment_requires_nonfragile_object) 6598 << ResultTy; 6599 } 6600 if (CompResultTy.isNull()) 6601 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6602 else 6603 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6604 CompLHSTy, CompResultTy, 6605 OpLoc)); 6606} 6607 6608/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6609/// ParenRange in parentheses. 6610static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6611 const PartialDiagnostic &PD, 6612 const PartialDiagnostic &FirstNote, 6613 SourceRange FirstParenRange, 6614 const PartialDiagnostic &SecondNote, 6615 SourceRange SecondParenRange) { 6616 Self.Diag(Loc, PD); 6617 6618 if (!FirstNote.getDiagID()) 6619 return; 6620 6621 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 6622 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6623 // We can't display the parentheses, so just return. 6624 return; 6625 } 6626 6627 Self.Diag(Loc, FirstNote) 6628 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 6629 << FixItHint::CreateInsertion(EndLoc, ")"); 6630 6631 if (!SecondNote.getDiagID()) 6632 return; 6633 6634 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6635 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6636 // We can't display the parentheses, so just dig the 6637 // warning/error and return. 6638 Self.Diag(Loc, SecondNote); 6639 return; 6640 } 6641 6642 Self.Diag(Loc, SecondNote) 6643 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6644 << FixItHint::CreateInsertion(EndLoc, ")"); 6645} 6646 6647/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6648/// operators are mixed in a way that suggests that the programmer forgot that 6649/// comparison operators have higher precedence. The most typical example of 6650/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6651static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperatorKind Opc, 6652 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6653 typedef BinaryOperator BinOp; 6654 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6655 rhsopc = static_cast<BinOp::Opcode>(-1); 6656 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6657 lhsopc = BO->getOpcode(); 6658 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6659 rhsopc = BO->getOpcode(); 6660 6661 // Subs are not binary operators. 6662 if (lhsopc == -1 && rhsopc == -1) 6663 return; 6664 6665 // Bitwise operations are sometimes used as eager logical ops. 6666 // Don't diagnose this. 6667 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6668 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6669 return; 6670 6671 if (BinOp::isComparisonOp(lhsopc)) 6672 SuggestParentheses(Self, OpLoc, 6673 Self.PDiag(diag::warn_precedence_bitwise_rel) 6674 << SourceRange(lhs->getLocStart(), OpLoc) 6675 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6676 Self.PDiag(diag::note_precedence_bitwise_first) 6677 << BinOp::getOpcodeStr(Opc), 6678 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 6679 Self.PDiag(diag::note_precedence_bitwise_silence) 6680 << BinOp::getOpcodeStr(lhsopc), 6681 lhs->getSourceRange()); 6682 else if (BinOp::isComparisonOp(rhsopc)) 6683 SuggestParentheses(Self, OpLoc, 6684 Self.PDiag(diag::warn_precedence_bitwise_rel) 6685 << SourceRange(OpLoc, rhs->getLocEnd()) 6686 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6687 Self.PDiag(diag::note_precedence_bitwise_first) 6688 << BinOp::getOpcodeStr(Opc), 6689 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 6690 Self.PDiag(diag::note_precedence_bitwise_silence) 6691 << BinOp::getOpcodeStr(rhsopc), 6692 rhs->getSourceRange()); 6693} 6694 6695/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6696/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6697/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6698static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, 6699 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6700 if (BinaryOperator::isBitwiseOp(Opc)) 6701 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6702} 6703 6704// Binary Operators. 'Tok' is the token for the operator. 6705ExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6706 tok::TokenKind Kind, 6707 Expr *lhs, Expr *rhs) { 6708 BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Kind); 6709 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6710 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6711 6712 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6713 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6714 6715 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6716} 6717 6718ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6719 BinaryOperatorKind Opc, 6720 Expr *lhs, Expr *rhs) { 6721 if (getLangOptions().CPlusPlus && 6722 ((!isa<ObjCImplicitSetterGetterRefExpr>(lhs) && 6723 !isa<ObjCPropertyRefExpr>(lhs)) 6724 || rhs->isTypeDependent() || Opc != BO_Assign) && 6725 (lhs->getType()->isOverloadableType() || 6726 rhs->getType()->isOverloadableType())) { 6727 // Find all of the overloaded operators visible from this 6728 // point. We perform both an operator-name lookup from the local 6729 // scope and an argument-dependent lookup based on the types of 6730 // the arguments. 6731 UnresolvedSet<16> Functions; 6732 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6733 if (S && OverOp != OO_None) 6734 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6735 Functions); 6736 6737 // Build the (potentially-overloaded, potentially-dependent) 6738 // binary operation. 6739 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6740 } 6741 6742 // Build a built-in binary operation. 6743 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6744} 6745 6746ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6747 unsigned OpcIn, 6748 Expr *Input) { 6749 UnaryOperatorKind Opc = static_cast<UnaryOperatorKind>(OpcIn); 6750 6751 QualType resultType; 6752 switch (Opc) { 6753 case UO_PreInc: 6754 case UO_PreDec: 6755 case UO_PostInc: 6756 case UO_PostDec: 6757 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6758 Opc == UO_PreInc || 6759 Opc == UO_PostInc, 6760 Opc == UO_PreInc || 6761 Opc == UO_PreDec); 6762 break; 6763 case UO_AddrOf: 6764 resultType = CheckAddressOfOperand(Input, OpLoc); 6765 break; 6766 case UO_Deref: 6767 DefaultFunctionArrayLvalueConversion(Input); 6768 resultType = CheckIndirectionOperand(Input, OpLoc); 6769 break; 6770 case UO_Plus: 6771 case UO_Minus: 6772 UsualUnaryConversions(Input); 6773 resultType = Input->getType(); 6774 if (resultType->isDependentType()) 6775 break; 6776 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 6777 resultType->isVectorType()) 6778 break; 6779 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6780 resultType->isEnumeralType()) 6781 break; 6782 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6783 Opc == UO_Plus && 6784 resultType->isPointerType()) 6785 break; 6786 6787 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6788 << resultType << Input->getSourceRange()); 6789 case UO_Not: // bitwise complement 6790 UsualUnaryConversions(Input); 6791 resultType = Input->getType(); 6792 if (resultType->isDependentType()) 6793 break; 6794 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6795 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6796 // C99 does not support '~' for complex conjugation. 6797 Diag(OpLoc, diag::ext_integer_complement_complex) 6798 << resultType << Input->getSourceRange(); 6799 else if (!resultType->hasIntegerRepresentation()) 6800 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6801 << resultType << Input->getSourceRange()); 6802 break; 6803 case UO_LNot: // logical negation 6804 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6805 DefaultFunctionArrayLvalueConversion(Input); 6806 resultType = Input->getType(); 6807 if (resultType->isDependentType()) 6808 break; 6809 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6810 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6811 << resultType << Input->getSourceRange()); 6812 // LNot always has type int. C99 6.5.3.3p5. 6813 // In C++, it's bool. C++ 5.3.1p8 6814 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6815 break; 6816 case UO_Real: 6817 case UO_Imag: 6818 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UO_Real); 6819 break; 6820 case UO_Extension: 6821 resultType = Input->getType(); 6822 break; 6823 } 6824 if (resultType.isNull()) 6825 return ExprError(); 6826 6827 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6828} 6829 6830ExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6831 UnaryOperatorKind Opc, 6832 Expr *Input) { 6833 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6834 UnaryOperator::getOverloadedOperator(Opc) != OO_None) { 6835 // Find all of the overloaded operators visible from this 6836 // point. We perform both an operator-name lookup from the local 6837 // scope and an argument-dependent lookup based on the types of 6838 // the arguments. 6839 UnresolvedSet<16> Functions; 6840 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6841 if (S && OverOp != OO_None) 6842 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6843 Functions); 6844 6845 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); 6846 } 6847 6848 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6849} 6850 6851// Unary Operators. 'Tok' is the token for the operator. 6852ExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6853 tok::TokenKind Op, Expr *Input) { 6854 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); 6855} 6856 6857/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6858ExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6859 SourceLocation LabLoc, 6860 IdentifierInfo *LabelII) { 6861 // Look up the record for this label identifier. 6862 LabelStmt *&LabelDecl = getCurFunction()->LabelMap[LabelII]; 6863 6864 // If we haven't seen this label yet, create a forward reference. It 6865 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6866 if (LabelDecl == 0) 6867 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6868 6869 // Create the AST node. The address of a label always has type 'void*'. 6870 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6871 Context.getPointerType(Context.VoidTy))); 6872} 6873 6874ExprResult 6875Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, 6876 SourceLocation RPLoc) { // "({..})" 6877 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6878 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6879 6880 bool isFileScope 6881 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6882 if (isFileScope) 6883 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6884 6885 // FIXME: there are a variety of strange constraints to enforce here, for 6886 // example, it is not possible to goto into a stmt expression apparently. 6887 // More semantic analysis is needed. 6888 6889 // If there are sub stmts in the compound stmt, take the type of the last one 6890 // as the type of the stmtexpr. 6891 QualType Ty = Context.VoidTy; 6892 6893 if (!Compound->body_empty()) { 6894 Stmt *LastStmt = Compound->body_back(); 6895 // If LastStmt is a label, skip down through into the body. 6896 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6897 LastStmt = Label->getSubStmt(); 6898 6899 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6900 Ty = LastExpr->getType(); 6901 } 6902 6903 // FIXME: Check that expression type is complete/non-abstract; statement 6904 // expressions are not lvalues. 6905 6906 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6907} 6908 6909ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 6910 TypeSourceInfo *TInfo, 6911 OffsetOfComponent *CompPtr, 6912 unsigned NumComponents, 6913 SourceLocation RParenLoc) { 6914 QualType ArgTy = TInfo->getType(); 6915 bool Dependent = ArgTy->isDependentType(); 6916 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 6917 6918 // We must have at least one component that refers to the type, and the first 6919 // one is known to be a field designator. Verify that the ArgTy represents 6920 // a struct/union/class. 6921 if (!Dependent && !ArgTy->isRecordType()) 6922 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 6923 << ArgTy << TypeRange); 6924 6925 // Type must be complete per C99 7.17p3 because a declaring a variable 6926 // with an incomplete type would be ill-formed. 6927 if (!Dependent 6928 && RequireCompleteType(BuiltinLoc, ArgTy, 6929 PDiag(diag::err_offsetof_incomplete_type) 6930 << TypeRange)) 6931 return ExprError(); 6932 6933 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6934 // GCC extension, diagnose them. 6935 // FIXME: This diagnostic isn't actually visible because the location is in 6936 // a system header! 6937 if (NumComponents != 1) 6938 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6939 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6940 6941 bool DidWarnAboutNonPOD = false; 6942 QualType CurrentType = ArgTy; 6943 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 6944 llvm::SmallVector<OffsetOfNode, 4> Comps; 6945 llvm::SmallVector<Expr*, 4> Exprs; 6946 for (unsigned i = 0; i != NumComponents; ++i) { 6947 const OffsetOfComponent &OC = CompPtr[i]; 6948 if (OC.isBrackets) { 6949 // Offset of an array sub-field. TODO: Should we allow vector elements? 6950 if (!CurrentType->isDependentType()) { 6951 const ArrayType *AT = Context.getAsArrayType(CurrentType); 6952 if(!AT) 6953 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6954 << CurrentType); 6955 CurrentType = AT->getElementType(); 6956 } else 6957 CurrentType = Context.DependentTy; 6958 6959 // The expression must be an integral expression. 6960 // FIXME: An integral constant expression? 6961 Expr *Idx = static_cast<Expr*>(OC.U.E); 6962 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 6963 !Idx->getType()->isIntegerType()) 6964 return ExprError(Diag(Idx->getLocStart(), 6965 diag::err_typecheck_subscript_not_integer) 6966 << Idx->getSourceRange()); 6967 6968 // Record this array index. 6969 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 6970 Exprs.push_back(Idx); 6971 continue; 6972 } 6973 6974 // Offset of a field. 6975 if (CurrentType->isDependentType()) { 6976 // We have the offset of a field, but we can't look into the dependent 6977 // type. Just record the identifier of the field. 6978 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 6979 CurrentType = Context.DependentTy; 6980 continue; 6981 } 6982 6983 // We need to have a complete type to look into. 6984 if (RequireCompleteType(OC.LocStart, CurrentType, 6985 diag::err_offsetof_incomplete_type)) 6986 return ExprError(); 6987 6988 // Look for the designated field. 6989 const RecordType *RC = CurrentType->getAs<RecordType>(); 6990 if (!RC) 6991 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6992 << CurrentType); 6993 RecordDecl *RD = RC->getDecl(); 6994 6995 // C++ [lib.support.types]p5: 6996 // The macro offsetof accepts a restricted set of type arguments in this 6997 // International Standard. type shall be a POD structure or a POD union 6998 // (clause 9). 6999 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 7000 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 7001 DiagRuntimeBehavior(BuiltinLoc, 7002 PDiag(diag::warn_offsetof_non_pod_type) 7003 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 7004 << CurrentType)) 7005 DidWarnAboutNonPOD = true; 7006 } 7007 7008 // Look for the field. 7009 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 7010 LookupQualifiedName(R, RD); 7011 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 7012 if (!MemberDecl) 7013 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 7014 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 7015 OC.LocEnd)); 7016 7017 // C99 7.17p3: 7018 // (If the specified member is a bit-field, the behavior is undefined.) 7019 // 7020 // We diagnose this as an error. 7021 if (MemberDecl->getBitWidth()) { 7022 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 7023 << MemberDecl->getDeclName() 7024 << SourceRange(BuiltinLoc, RParenLoc); 7025 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 7026 return ExprError(); 7027 } 7028 7029 RecordDecl *Parent = MemberDecl->getParent(); 7030 bool AnonStructUnion = Parent->isAnonymousStructOrUnion(); 7031 if (AnonStructUnion) { 7032 do { 7033 Parent = cast<RecordDecl>(Parent->getParent()); 7034 } while (Parent->isAnonymousStructOrUnion()); 7035 } 7036 7037 // If the member was found in a base class, introduce OffsetOfNodes for 7038 // the base class indirections. 7039 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 7040 /*DetectVirtual=*/false); 7041 if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { 7042 CXXBasePath &Path = Paths.front(); 7043 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 7044 B != BEnd; ++B) 7045 Comps.push_back(OffsetOfNode(B->Base)); 7046 } 7047 7048 if (AnonStructUnion) { 7049 llvm::SmallVector<FieldDecl*, 4> Path; 7050 BuildAnonymousStructUnionMemberPath(MemberDecl, Path); 7051 unsigned n = Path.size(); 7052 for (int j = n - 1; j > -1; --j) 7053 Comps.push_back(OffsetOfNode(OC.LocStart, Path[j], OC.LocEnd)); 7054 } else { 7055 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 7056 } 7057 CurrentType = MemberDecl->getType().getNonReferenceType(); 7058 } 7059 7060 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 7061 TInfo, Comps.data(), Comps.size(), 7062 Exprs.data(), Exprs.size(), RParenLoc)); 7063} 7064 7065ExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 7066 SourceLocation BuiltinLoc, 7067 SourceLocation TypeLoc, 7068 ParsedType argty, 7069 OffsetOfComponent *CompPtr, 7070 unsigned NumComponents, 7071 SourceLocation RPLoc) { 7072 7073 TypeSourceInfo *ArgTInfo; 7074 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 7075 if (ArgTy.isNull()) 7076 return ExprError(); 7077 7078 if (!ArgTInfo) 7079 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 7080 7081 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 7082 RPLoc); 7083} 7084 7085 7086ExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 7087 ParsedType arg1,ParsedType arg2, 7088 SourceLocation RPLoc) { 7089 TypeSourceInfo *argTInfo1; 7090 QualType argT1 = GetTypeFromParser(arg1, &argTInfo1); 7091 TypeSourceInfo *argTInfo2; 7092 QualType argT2 = GetTypeFromParser(arg2, &argTInfo2); 7093 7094 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 7095 7096 return BuildTypesCompatibleExpr(BuiltinLoc, argTInfo1, argTInfo2, RPLoc); 7097} 7098 7099ExprResult 7100Sema::BuildTypesCompatibleExpr(SourceLocation BuiltinLoc, 7101 TypeSourceInfo *argTInfo1, 7102 TypeSourceInfo *argTInfo2, 7103 SourceLocation RPLoc) { 7104 if (getLangOptions().CPlusPlus) { 7105 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 7106 << SourceRange(BuiltinLoc, RPLoc); 7107 return ExprError(); 7108 } 7109 7110 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 7111 argTInfo1, argTInfo2, RPLoc)); 7112} 7113 7114 7115ExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 7116 Expr *CondExpr, 7117 Expr *LHSExpr, Expr *RHSExpr, 7118 SourceLocation RPLoc) { 7119 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 7120 7121 QualType resType; 7122 bool ValueDependent = false; 7123 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 7124 resType = Context.DependentTy; 7125 ValueDependent = true; 7126 } else { 7127 // The conditional expression is required to be a constant expression. 7128 llvm::APSInt condEval(32); 7129 SourceLocation ExpLoc; 7130 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 7131 return ExprError(Diag(ExpLoc, 7132 diag::err_typecheck_choose_expr_requires_constant) 7133 << CondExpr->getSourceRange()); 7134 7135 // If the condition is > zero, then the AST type is the same as the LSHExpr. 7136 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 7137 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 7138 : RHSExpr->isValueDependent(); 7139 } 7140 7141 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 7142 resType, RPLoc, 7143 resType->isDependentType(), 7144 ValueDependent)); 7145} 7146 7147//===----------------------------------------------------------------------===// 7148// Clang Extensions. 7149//===----------------------------------------------------------------------===// 7150 7151/// ActOnBlockStart - This callback is invoked when a block literal is started. 7152void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 7153 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 7154 PushBlockScope(BlockScope, Block); 7155 CurContext->addDecl(Block); 7156 if (BlockScope) 7157 PushDeclContext(BlockScope, Block); 7158 else 7159 CurContext = Block; 7160} 7161 7162void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 7163 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 7164 BlockScopeInfo *CurBlock = getCurBlock(); 7165 7166 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 7167 CurBlock->TheDecl->setSignatureAsWritten(Sig); 7168 QualType T = Sig->getType(); 7169 7170 bool isVariadic; 7171 QualType RetTy; 7172 if (const FunctionType *Fn = T->getAs<FunctionType>()) { 7173 CurBlock->FunctionType = T; 7174 RetTy = Fn->getResultType(); 7175 isVariadic = 7176 !isa<FunctionProtoType>(Fn) || cast<FunctionProtoType>(Fn)->isVariadic(); 7177 } else { 7178 RetTy = T; 7179 isVariadic = false; 7180 } 7181 7182 CurBlock->TheDecl->setIsVariadic(isVariadic); 7183 7184 // Don't allow returning an array by value. 7185 if (RetTy->isArrayType()) { 7186 Diag(ParamInfo.getSourceRange().getBegin(), diag::err_block_returns_array); 7187 return; 7188 } 7189 7190 // Don't allow returning a objc interface by value. 7191 if (RetTy->isObjCObjectType()) { 7192 Diag(ParamInfo.getSourceRange().getBegin(), 7193 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7194 return; 7195 } 7196 7197 // Context.DependentTy is used as a placeholder for a missing block 7198 // return type. TODO: what should we do with declarators like: 7199 // ^ * { ... } 7200 // If the answer is "apply template argument deduction".... 7201 if (RetTy != Context.DependentTy) 7202 CurBlock->ReturnType = RetTy; 7203 7204 // Push block parameters from the declarator if we had them. 7205 llvm::SmallVector<ParmVarDecl*, 8> Params; 7206 if (isa<FunctionProtoType>(T)) { 7207 FunctionProtoTypeLoc TL = cast<FunctionProtoTypeLoc>(Sig->getTypeLoc()); 7208 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 7209 ParmVarDecl *Param = TL.getArg(I); 7210 if (Param->getIdentifier() == 0 && 7211 !Param->isImplicit() && 7212 !Param->isInvalidDecl() && 7213 !getLangOptions().CPlusPlus) 7214 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 7215 Params.push_back(Param); 7216 } 7217 7218 // Fake up parameter variables if we have a typedef, like 7219 // ^ fntype { ... } 7220 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 7221 for (FunctionProtoType::arg_type_iterator 7222 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 7223 ParmVarDecl *Param = 7224 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 7225 ParamInfo.getSourceRange().getBegin(), 7226 *I); 7227 Params.push_back(Param); 7228 } 7229 } 7230 7231 // Set the parameters on the block decl. 7232 if (!Params.empty()) 7233 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 7234 7235 // Finally we can process decl attributes. 7236 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 7237 7238 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 7239 Diag(ParamInfo.getAttributes()->getLoc(), 7240 diag::warn_attribute_sentinel_not_variadic) << 1; 7241 // FIXME: remove the attribute. 7242 } 7243 7244 // Put the parameter variables in scope. We can bail out immediately 7245 // if we don't have any. 7246 if (Params.empty()) 7247 return; 7248 7249 bool ShouldCheckShadow = 7250 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 7251 7252 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 7253 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 7254 (*AI)->setOwningFunction(CurBlock->TheDecl); 7255 7256 // If this has an identifier, add it to the scope stack. 7257 if ((*AI)->getIdentifier()) { 7258 if (ShouldCheckShadow) 7259 CheckShadow(CurBlock->TheScope, *AI); 7260 7261 PushOnScopeChains(*AI, CurBlock->TheScope); 7262 } 7263 } 7264} 7265 7266/// ActOnBlockError - If there is an error parsing a block, this callback 7267/// is invoked to pop the information about the block from the action impl. 7268void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7269 // Pop off CurBlock, handle nested blocks. 7270 PopDeclContext(); 7271 PopFunctionOrBlockScope(); 7272 // FIXME: Delete the ParmVarDecl objects as well??? 7273} 7274 7275/// ActOnBlockStmtExpr - This is called when the body of a block statement 7276/// literal was successfully completed. ^(int x){...} 7277ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7278 Stmt *Body, Scope *CurScope) { 7279 // If blocks are disabled, emit an error. 7280 if (!LangOpts.Blocks) 7281 Diag(CaretLoc, diag::err_blocks_disable); 7282 7283 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7284 7285 PopDeclContext(); 7286 7287 QualType RetTy = Context.VoidTy; 7288 if (!BSI->ReturnType.isNull()) 7289 RetTy = BSI->ReturnType; 7290 7291 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7292 QualType BlockTy; 7293 7294 // If the user wrote a function type in some form, try to use that. 7295 if (!BSI->FunctionType.isNull()) { 7296 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 7297 7298 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 7299 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 7300 7301 // Turn protoless block types into nullary block types. 7302 if (isa<FunctionNoProtoType>(FTy)) { 7303 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7304 false, false, 0, 0, Ext); 7305 7306 // Otherwise, if we don't need to change anything about the function type, 7307 // preserve its sugar structure. 7308 } else if (FTy->getResultType() == RetTy && 7309 (!NoReturn || FTy->getNoReturnAttr())) { 7310 BlockTy = BSI->FunctionType; 7311 7312 // Otherwise, make the minimal modifications to the function type. 7313 } else { 7314 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 7315 BlockTy = Context.getFunctionType(RetTy, 7316 FPT->arg_type_begin(), 7317 FPT->getNumArgs(), 7318 FPT->isVariadic(), 7319 /*quals*/ 0, 7320 FPT->hasExceptionSpec(), 7321 FPT->hasAnyExceptionSpec(), 7322 FPT->getNumExceptions(), 7323 FPT->exception_begin(), 7324 Ext); 7325 } 7326 7327 // If we don't have a function type, just build one from nothing. 7328 } else { 7329 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7330 false, false, 0, 0, 7331 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7332 } 7333 7334 // FIXME: Check that return/parameter types are complete/non-abstract 7335 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 7336 BSI->TheDecl->param_end()); 7337 BlockTy = Context.getBlockPointerType(BlockTy); 7338 7339 // If needed, diagnose invalid gotos and switches in the block. 7340 if (getCurFunction()->NeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7341 DiagnoseInvalidJumps(cast<CompoundStmt>(Body)); 7342 7343 BSI->TheDecl->setBody(cast<CompoundStmt>(Body)); 7344 7345 bool Good = true; 7346 // Check goto/label use. 7347 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7348 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7349 LabelStmt *L = I->second; 7350 7351 // Verify that we have no forward references left. If so, there was a goto 7352 // or address of a label taken, but no definition of it. 7353 if (L->getSubStmt() != 0) 7354 continue; 7355 7356 // Emit error. 7357 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7358 Good = false; 7359 } 7360 if (!Good) { 7361 PopFunctionOrBlockScope(); 7362 return ExprError(); 7363 } 7364 7365 BlockExpr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7366 BSI->hasBlockDeclRefExprs); 7367 7368 // Issue any analysis-based warnings. 7369 const sema::AnalysisBasedWarnings::Policy &WP = 7370 AnalysisWarnings.getDefaultPolicy(); 7371 AnalysisWarnings.IssueWarnings(WP, Result); 7372 7373 PopFunctionOrBlockScope(); 7374 return Owned(Result); 7375} 7376 7377ExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7378 Expr *expr, ParsedType type, 7379 SourceLocation RPLoc) { 7380 TypeSourceInfo *TInfo; 7381 QualType T = GetTypeFromParser(type, &TInfo); 7382 return BuildVAArgExpr(BuiltinLoc, expr, TInfo, RPLoc); 7383} 7384 7385ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, 7386 Expr *E, TypeSourceInfo *TInfo, 7387 SourceLocation RPLoc) { 7388 Expr *OrigExpr = E; 7389 7390 InitBuiltinVaListType(); 7391 7392 // Get the va_list type 7393 QualType VaListType = Context.getBuiltinVaListType(); 7394 if (VaListType->isArrayType()) { 7395 // Deal with implicit array decay; for example, on x86-64, 7396 // va_list is an array, but it's supposed to decay to 7397 // a pointer for va_arg. 7398 VaListType = Context.getArrayDecayedType(VaListType); 7399 // Make sure the input expression also decays appropriately. 7400 UsualUnaryConversions(E); 7401 } else { 7402 // Otherwise, the va_list argument must be an l-value because 7403 // it is modified by va_arg. 7404 if (!E->isTypeDependent() && 7405 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7406 return ExprError(); 7407 } 7408 7409 if (!E->isTypeDependent() && 7410 !Context.hasSameType(VaListType, E->getType())) { 7411 return ExprError(Diag(E->getLocStart(), 7412 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7413 << OrigExpr->getType() << E->getSourceRange()); 7414 } 7415 7416 // FIXME: Check that type is complete/non-abstract 7417 // FIXME: Warn if a non-POD type is passed in. 7418 7419 QualType T = TInfo->getType().getNonLValueExprType(Context); 7420 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T)); 7421} 7422 7423ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7424 // The type of __null will be int or long, depending on the size of 7425 // pointers on the target. 7426 QualType Ty; 7427 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7428 Ty = Context.IntTy; 7429 else 7430 Ty = Context.LongTy; 7431 7432 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7433} 7434 7435static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7436 Expr *SrcExpr, FixItHint &Hint) { 7437 if (!SemaRef.getLangOptions().ObjC1) 7438 return; 7439 7440 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7441 if (!PT) 7442 return; 7443 7444 // Check if the destination is of type 'id'. 7445 if (!PT->isObjCIdType()) { 7446 // Check if the destination is the 'NSString' interface. 7447 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7448 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7449 return; 7450 } 7451 7452 // Strip off any parens and casts. 7453 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7454 if (!SL || SL->isWide()) 7455 return; 7456 7457 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7458} 7459 7460bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7461 SourceLocation Loc, 7462 QualType DstType, QualType SrcType, 7463 Expr *SrcExpr, AssignmentAction Action, 7464 bool *Complained) { 7465 if (Complained) 7466 *Complained = false; 7467 7468 // Decode the result (notice that AST's are still created for extensions). 7469 bool isInvalid = false; 7470 unsigned DiagKind; 7471 FixItHint Hint; 7472 7473 switch (ConvTy) { 7474 default: assert(0 && "Unknown conversion type"); 7475 case Compatible: return false; 7476 case PointerToInt: 7477 DiagKind = diag::ext_typecheck_convert_pointer_int; 7478 break; 7479 case IntToPointer: 7480 DiagKind = diag::ext_typecheck_convert_int_pointer; 7481 break; 7482 case IncompatiblePointer: 7483 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7484 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7485 break; 7486 case IncompatiblePointerSign: 7487 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7488 break; 7489 case FunctionVoidPointer: 7490 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7491 break; 7492 case CompatiblePointerDiscardsQualifiers: 7493 // If the qualifiers lost were because we were applying the 7494 // (deprecated) C++ conversion from a string literal to a char* 7495 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7496 // Ideally, this check would be performed in 7497 // CheckPointerTypesForAssignment. However, that would require a 7498 // bit of refactoring (so that the second argument is an 7499 // expression, rather than a type), which should be done as part 7500 // of a larger effort to fix CheckPointerTypesForAssignment for 7501 // C++ semantics. 7502 if (getLangOptions().CPlusPlus && 7503 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7504 return false; 7505 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7506 break; 7507 case IncompatibleNestedPointerQualifiers: 7508 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7509 break; 7510 case IntToBlockPointer: 7511 DiagKind = diag::err_int_to_block_pointer; 7512 break; 7513 case IncompatibleBlockPointer: 7514 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7515 break; 7516 case IncompatibleObjCQualifiedId: 7517 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7518 // it can give a more specific diagnostic. 7519 DiagKind = diag::warn_incompatible_qualified_id; 7520 break; 7521 case IncompatibleVectors: 7522 DiagKind = diag::warn_incompatible_vectors; 7523 break; 7524 case Incompatible: 7525 DiagKind = diag::err_typecheck_convert_incompatible; 7526 isInvalid = true; 7527 break; 7528 } 7529 7530 QualType FirstType, SecondType; 7531 switch (Action) { 7532 case AA_Assigning: 7533 case AA_Initializing: 7534 // The destination type comes first. 7535 FirstType = DstType; 7536 SecondType = SrcType; 7537 break; 7538 7539 case AA_Returning: 7540 case AA_Passing: 7541 case AA_Converting: 7542 case AA_Sending: 7543 case AA_Casting: 7544 // The source type comes first. 7545 FirstType = SrcType; 7546 SecondType = DstType; 7547 break; 7548 } 7549 7550 Diag(Loc, DiagKind) << FirstType << SecondType << Action 7551 << SrcExpr->getSourceRange() << Hint; 7552 if (Complained) 7553 *Complained = true; 7554 return isInvalid; 7555} 7556 7557bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7558 llvm::APSInt ICEResult; 7559 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7560 if (Result) 7561 *Result = ICEResult; 7562 return false; 7563 } 7564 7565 Expr::EvalResult EvalResult; 7566 7567 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7568 EvalResult.HasSideEffects) { 7569 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7570 7571 if (EvalResult.Diag) { 7572 // We only show the note if it's not the usual "invalid subexpression" 7573 // or if it's actually in a subexpression. 7574 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7575 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7576 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7577 } 7578 7579 return true; 7580 } 7581 7582 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7583 E->getSourceRange(); 7584 7585 if (EvalResult.Diag && 7586 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7587 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7588 7589 if (Result) 7590 *Result = EvalResult.Val.getInt(); 7591 return false; 7592} 7593 7594void 7595Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7596 ExprEvalContexts.push_back( 7597 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7598} 7599 7600void 7601Sema::PopExpressionEvaluationContext() { 7602 // Pop the current expression evaluation context off the stack. 7603 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7604 ExprEvalContexts.pop_back(); 7605 7606 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7607 if (Rec.PotentiallyReferenced) { 7608 // Mark any remaining declarations in the current position of the stack 7609 // as "referenced". If they were not meant to be referenced, semantic 7610 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7611 for (PotentiallyReferencedDecls::iterator 7612 I = Rec.PotentiallyReferenced->begin(), 7613 IEnd = Rec.PotentiallyReferenced->end(); 7614 I != IEnd; ++I) 7615 MarkDeclarationReferenced(I->first, I->second); 7616 } 7617 7618 if (Rec.PotentiallyDiagnosed) { 7619 // Emit any pending diagnostics. 7620 for (PotentiallyEmittedDiagnostics::iterator 7621 I = Rec.PotentiallyDiagnosed->begin(), 7622 IEnd = Rec.PotentiallyDiagnosed->end(); 7623 I != IEnd; ++I) 7624 Diag(I->first, I->second); 7625 } 7626 } 7627 7628 // When are coming out of an unevaluated context, clear out any 7629 // temporaries that we may have created as part of the evaluation of 7630 // the expression in that context: they aren't relevant because they 7631 // will never be constructed. 7632 if (Rec.Context == Unevaluated && 7633 ExprTemporaries.size() > Rec.NumTemporaries) 7634 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7635 ExprTemporaries.end()); 7636 7637 // Destroy the popped expression evaluation record. 7638 Rec.Destroy(); 7639} 7640 7641/// \brief Note that the given declaration was referenced in the source code. 7642/// 7643/// This routine should be invoke whenever a given declaration is referenced 7644/// in the source code, and where that reference occurred. If this declaration 7645/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7646/// C99 6.9p3), then the declaration will be marked as used. 7647/// 7648/// \param Loc the location where the declaration was referenced. 7649/// 7650/// \param D the declaration that has been referenced by the source code. 7651void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7652 assert(D && "No declaration?"); 7653 7654 if (D->isUsed(false)) 7655 return; 7656 7657 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7658 // template or not. The reason for this is that unevaluated expressions 7659 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7660 // -Wunused-parameters) 7661 if (isa<ParmVarDecl>(D) || 7662 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7663 D->setUsed(true); 7664 return; 7665 } 7666 7667 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7668 return; 7669 7670 // Do not mark anything as "used" within a dependent context; wait for 7671 // an instantiation. 7672 if (CurContext->isDependentContext()) 7673 return; 7674 7675 switch (ExprEvalContexts.back().Context) { 7676 case Unevaluated: 7677 // We are in an expression that is not potentially evaluated; do nothing. 7678 return; 7679 7680 case PotentiallyEvaluated: 7681 // We are in a potentially-evaluated expression, so this declaration is 7682 // "used"; handle this below. 7683 break; 7684 7685 case PotentiallyPotentiallyEvaluated: 7686 // We are in an expression that may be potentially evaluated; queue this 7687 // declaration reference until we know whether the expression is 7688 // potentially evaluated. 7689 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7690 return; 7691 7692 case PotentiallyEvaluatedIfUsed: 7693 // Referenced declarations will only be used if the construct in the 7694 // containing expression is used. 7695 return; 7696 } 7697 7698 // Note that this declaration has been used. 7699 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7700 unsigned TypeQuals; 7701 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7702 if (Constructor->getParent()->hasTrivialConstructor()) 7703 return; 7704 if (!Constructor->isUsed(false)) 7705 DefineImplicitDefaultConstructor(Loc, Constructor); 7706 } else if (Constructor->isImplicit() && 7707 Constructor->isCopyConstructor(TypeQuals)) { 7708 if (!Constructor->isUsed(false)) 7709 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7710 } 7711 7712 MarkVTableUsed(Loc, Constructor->getParent()); 7713 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7714 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 7715 DefineImplicitDestructor(Loc, Destructor); 7716 if (Destructor->isVirtual()) 7717 MarkVTableUsed(Loc, Destructor->getParent()); 7718 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7719 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7720 MethodDecl->getOverloadedOperator() == OO_Equal) { 7721 if (!MethodDecl->isUsed(false)) 7722 DefineImplicitCopyAssignment(Loc, MethodDecl); 7723 } else if (MethodDecl->isVirtual()) 7724 MarkVTableUsed(Loc, MethodDecl->getParent()); 7725 } 7726 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7727 // Implicit instantiation of function templates and member functions of 7728 // class templates. 7729 if (Function->isImplicitlyInstantiable()) { 7730 bool AlreadyInstantiated = false; 7731 if (FunctionTemplateSpecializationInfo *SpecInfo 7732 = Function->getTemplateSpecializationInfo()) { 7733 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7734 SpecInfo->setPointOfInstantiation(Loc); 7735 else if (SpecInfo->getTemplateSpecializationKind() 7736 == TSK_ImplicitInstantiation) 7737 AlreadyInstantiated = true; 7738 } else if (MemberSpecializationInfo *MSInfo 7739 = Function->getMemberSpecializationInfo()) { 7740 if (MSInfo->getPointOfInstantiation().isInvalid()) 7741 MSInfo->setPointOfInstantiation(Loc); 7742 else if (MSInfo->getTemplateSpecializationKind() 7743 == TSK_ImplicitInstantiation) 7744 AlreadyInstantiated = true; 7745 } 7746 7747 if (!AlreadyInstantiated) { 7748 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7749 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7750 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7751 Loc)); 7752 else 7753 PendingInstantiations.push_back(std::make_pair(Function, Loc)); 7754 } 7755 } else // Walk redefinitions, as some of them may be instantiable. 7756 for (FunctionDecl::redecl_iterator i(Function->redecls_begin()), 7757 e(Function->redecls_end()); i != e; ++i) { 7758 if (!i->isUsed(false) && i->isImplicitlyInstantiable()) 7759 MarkDeclarationReferenced(Loc, *i); 7760 } 7761 7762 // FIXME: keep track of references to static functions 7763 7764 // Recursive functions should be marked when used from another function. 7765 if (CurContext != Function) 7766 Function->setUsed(true); 7767 7768 return; 7769 } 7770 7771 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7772 // Implicit instantiation of static data members of class templates. 7773 if (Var->isStaticDataMember() && 7774 Var->getInstantiatedFromStaticDataMember()) { 7775 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7776 assert(MSInfo && "Missing member specialization information?"); 7777 if (MSInfo->getPointOfInstantiation().isInvalid() && 7778 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7779 MSInfo->setPointOfInstantiation(Loc); 7780 PendingInstantiations.push_back(std::make_pair(Var, Loc)); 7781 } 7782 } 7783 7784 // FIXME: keep track of references to static data? 7785 7786 D->setUsed(true); 7787 return; 7788 } 7789} 7790 7791namespace { 7792 // Mark all of the declarations referenced 7793 // FIXME: Not fully implemented yet! We need to have a better understanding 7794 // of when we're entering 7795 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 7796 Sema &S; 7797 SourceLocation Loc; 7798 7799 public: 7800 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 7801 7802 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 7803 7804 bool TraverseTemplateArgument(const TemplateArgument &Arg); 7805 bool TraverseRecordType(RecordType *T); 7806 }; 7807} 7808 7809bool MarkReferencedDecls::TraverseTemplateArgument( 7810 const TemplateArgument &Arg) { 7811 if (Arg.getKind() == TemplateArgument::Declaration) { 7812 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 7813 } 7814 7815 return Inherited::TraverseTemplateArgument(Arg); 7816} 7817 7818bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 7819 if (ClassTemplateSpecializationDecl *Spec 7820 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 7821 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 7822 return TraverseTemplateArguments(Args.getFlatArgumentList(), 7823 Args.flat_size()); 7824 } 7825 7826 return true; 7827} 7828 7829void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 7830 MarkReferencedDecls Marker(*this, Loc); 7831 Marker.TraverseType(Context.getCanonicalType(T)); 7832} 7833 7834namespace { 7835 /// \brief Helper class that marks all of the declarations referenced by 7836 /// potentially-evaluated subexpressions as "referenced". 7837 class EvaluatedExprMarker : public EvaluatedExprVisitor<EvaluatedExprMarker> { 7838 Sema &S; 7839 7840 public: 7841 typedef EvaluatedExprVisitor<EvaluatedExprMarker> Inherited; 7842 7843 explicit EvaluatedExprMarker(Sema &S) : Inherited(S.Context), S(S) { } 7844 7845 void VisitDeclRefExpr(DeclRefExpr *E) { 7846 S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); 7847 } 7848 7849 void VisitMemberExpr(MemberExpr *E) { 7850 S.MarkDeclarationReferenced(E->getMemberLoc(), E->getMemberDecl()); 7851 Inherited::VisitMemberExpr(E); 7852 } 7853 7854 void VisitCXXNewExpr(CXXNewExpr *E) { 7855 if (E->getConstructor()) 7856 S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); 7857 if (E->getOperatorNew()) 7858 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorNew()); 7859 if (E->getOperatorDelete()) 7860 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); 7861 Inherited::VisitCXXNewExpr(E); 7862 } 7863 7864 void VisitCXXDeleteExpr(CXXDeleteExpr *E) { 7865 if (E->getOperatorDelete()) 7866 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); 7867 QualType Destroyed = S.Context.getBaseElementType(E->getDestroyedType()); 7868 if (const RecordType *DestroyedRec = Destroyed->getAs<RecordType>()) { 7869 CXXRecordDecl *Record = cast<CXXRecordDecl>(DestroyedRec->getDecl()); 7870 S.MarkDeclarationReferenced(E->getLocStart(), 7871 S.LookupDestructor(Record)); 7872 } 7873 7874 Inherited::VisitCXXDeleteExpr(E); 7875 } 7876 7877 void VisitCXXConstructExpr(CXXConstructExpr *E) { 7878 S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); 7879 Inherited::VisitCXXConstructExpr(E); 7880 } 7881 7882 void VisitBlockDeclRefExpr(BlockDeclRefExpr *E) { 7883 S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); 7884 } 7885 }; 7886} 7887 7888/// \brief Mark any declarations that appear within this expression or any 7889/// potentially-evaluated subexpressions as "referenced". 7890void Sema::MarkDeclarationsReferencedInExpr(Expr *E) { 7891 EvaluatedExprMarker(*this).Visit(E); 7892} 7893 7894/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7895/// of the program being compiled. 7896/// 7897/// This routine emits the given diagnostic when the code currently being 7898/// type-checked is "potentially evaluated", meaning that there is a 7899/// possibility that the code will actually be executable. Code in sizeof() 7900/// expressions, code used only during overload resolution, etc., are not 7901/// potentially evaluated. This routine will suppress such diagnostics or, 7902/// in the absolutely nutty case of potentially potentially evaluated 7903/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7904/// later. 7905/// 7906/// This routine should be used for all diagnostics that describe the run-time 7907/// behavior of a program, such as passing a non-POD value through an ellipsis. 7908/// Failure to do so will likely result in spurious diagnostics or failures 7909/// during overload resolution or within sizeof/alignof/typeof/typeid. 7910bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7911 const PartialDiagnostic &PD) { 7912 switch (ExprEvalContexts.back().Context ) { 7913 case Unevaluated: 7914 // The argument will never be evaluated, so don't complain. 7915 break; 7916 7917 case PotentiallyEvaluated: 7918 case PotentiallyEvaluatedIfUsed: 7919 Diag(Loc, PD); 7920 return true; 7921 7922 case PotentiallyPotentiallyEvaluated: 7923 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7924 break; 7925 } 7926 7927 return false; 7928} 7929 7930bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7931 CallExpr *CE, FunctionDecl *FD) { 7932 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7933 return false; 7934 7935 PartialDiagnostic Note = 7936 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7937 << FD->getDeclName() : PDiag(); 7938 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7939 7940 if (RequireCompleteType(Loc, ReturnType, 7941 FD ? 7942 PDiag(diag::err_call_function_incomplete_return) 7943 << CE->getSourceRange() << FD->getDeclName() : 7944 PDiag(diag::err_call_incomplete_return) 7945 << CE->getSourceRange(), 7946 std::make_pair(NoteLoc, Note))) 7947 return true; 7948 7949 return false; 7950} 7951 7952// Diagnose the common s/=/==/ typo. Note that adding parentheses 7953// will prevent this condition from triggering, which is what we want. 7954void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7955 SourceLocation Loc; 7956 7957 unsigned diagnostic = diag::warn_condition_is_assignment; 7958 7959 if (isa<BinaryOperator>(E)) { 7960 BinaryOperator *Op = cast<BinaryOperator>(E); 7961 if (Op->getOpcode() != BO_Assign) 7962 return; 7963 7964 // Greylist some idioms by putting them into a warning subcategory. 7965 if (ObjCMessageExpr *ME 7966 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7967 Selector Sel = ME->getSelector(); 7968 7969 // self = [<foo> init...] 7970 if (isSelfExpr(Op->getLHS()) 7971 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7972 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7973 7974 // <foo> = [<bar> nextObject] 7975 else if (Sel.isUnarySelector() && 7976 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7977 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7978 } 7979 7980 Loc = Op->getOperatorLoc(); 7981 } else if (isa<CXXOperatorCallExpr>(E)) { 7982 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7983 if (Op->getOperator() != OO_Equal) 7984 return; 7985 7986 Loc = Op->getOperatorLoc(); 7987 } else { 7988 // Not an assignment. 7989 return; 7990 } 7991 7992 SourceLocation Open = E->getSourceRange().getBegin(); 7993 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7994 7995 Diag(Loc, diagnostic) << E->getSourceRange(); 7996 Diag(Loc, diag::note_condition_assign_to_comparison) 7997 << FixItHint::CreateReplacement(Loc, "=="); 7998 Diag(Loc, diag::note_condition_assign_silence) 7999 << FixItHint::CreateInsertion(Open, "(") 8000 << FixItHint::CreateInsertion(Close, ")"); 8001} 8002 8003bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 8004 DiagnoseAssignmentAsCondition(E); 8005 8006 if (!E->isTypeDependent()) { 8007 DefaultFunctionArrayLvalueConversion(E); 8008 8009 QualType T = E->getType(); 8010 8011 if (getLangOptions().CPlusPlus) { 8012 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 8013 return true; 8014 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 8015 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 8016 << T << E->getSourceRange(); 8017 return true; 8018 } 8019 } 8020 8021 return false; 8022} 8023 8024ExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 8025 Expr *Sub) { 8026 if (!Sub) 8027 return ExprError(); 8028 8029 if (CheckBooleanCondition(Sub, Loc)) 8030 return ExprError(); 8031 8032 return Owned(Sub); 8033} 8034