SemaExpr.cpp revision 5e1fe4d264f3777fbd3afd3301e0e515d88425d8
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/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/ExprObjC.h" 25#include "clang/AST/RecursiveASTVisitor.h" 26#include "clang/AST/TypeLoc.h" 27#include "clang/Basic/PartialDiagnostic.h" 28#include "clang/Basic/SourceManager.h" 29#include "clang/Basic/TargetInfo.h" 30#include "clang/Lex/LiteralSupport.h" 31#include "clang/Lex/Preprocessor.h" 32#include "clang/Sema/DeclSpec.h" 33#include "clang/Sema/Designator.h" 34#include "clang/Sema/Scope.h" 35#include "clang/Sema/ScopeInfo.h" 36#include "clang/Sema/ParsedTemplate.h" 37#include "clang/Sema/Template.h" 38using namespace clang; 39using namespace sema; 40 41 42/// \brief Determine whether the use of this declaration is valid, and 43/// emit any corresponding diagnostics. 44/// 45/// This routine diagnoses various problems with referencing 46/// declarations that can occur when using a declaration. For example, 47/// it might warn if a deprecated or unavailable declaration is being 48/// used, or produce an error (and return true) if a C++0x deleted 49/// function is being used. 50/// 51/// If IgnoreDeprecated is set to true, this should not want about deprecated 52/// decls. 53/// 54/// \returns true if there was an error (this declaration cannot be 55/// referenced), false otherwise. 56/// 57bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) { 58 // See if the decl is deprecated. 59 if (D->getAttr<DeprecatedAttr>()) { 60 EmitDeprecationWarning(D, Loc); 61 } 62 63 // See if the decl is unavailable 64 if (D->getAttr<UnavailableAttr>()) { 65 Diag(Loc, diag::err_unavailable) << D->getDeclName(); 66 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 67 } 68 69 // See if this is a deleted function. 70 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 71 if (FD->isDeleted()) { 72 Diag(Loc, diag::err_deleted_function_use); 73 Diag(D->getLocation(), diag::note_unavailable_here) << true; 74 return true; 75 } 76 } 77 78 return false; 79} 80 81/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 82/// (and other functions in future), which have been declared with sentinel 83/// attribute. It warns if call does not have the sentinel argument. 84/// 85void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 86 Expr **Args, unsigned NumArgs) { 87 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 88 if (!attr) 89 return; 90 91 // FIXME: In C++0x, if any of the arguments are parameter pack 92 // expansions, we can't check for the sentinel now. 93 int sentinelPos = attr->getSentinel(); 94 int nullPos = attr->getNullPos(); 95 96 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 97 // base class. Then we won't be needing two versions of the same code. 98 unsigned int i = 0; 99 bool warnNotEnoughArgs = false; 100 int isMethod = 0; 101 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 102 // skip over named parameters. 103 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 104 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 105 if (nullPos) 106 --nullPos; 107 else 108 ++i; 109 } 110 warnNotEnoughArgs = (P != E || i >= NumArgs); 111 isMethod = 1; 112 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 113 // skip over named parameters. 114 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 115 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 116 if (nullPos) 117 --nullPos; 118 else 119 ++i; 120 } 121 warnNotEnoughArgs = (P != E || i >= NumArgs); 122 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 123 // block or function pointer call. 124 QualType Ty = V->getType(); 125 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 126 const FunctionType *FT = Ty->isFunctionPointerType() 127 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 128 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 129 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 130 unsigned NumArgsInProto = Proto->getNumArgs(); 131 unsigned k; 132 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 133 if (nullPos) 134 --nullPos; 135 else 136 ++i; 137 } 138 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 139 } 140 if (Ty->isBlockPointerType()) 141 isMethod = 2; 142 } else 143 return; 144 } else 145 return; 146 147 if (warnNotEnoughArgs) { 148 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 149 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 150 return; 151 } 152 int sentinel = i; 153 while (sentinelPos > 0 && i < NumArgs-1) { 154 --sentinelPos; 155 ++i; 156 } 157 if (sentinelPos > 0) { 158 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 159 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 160 return; 161 } 162 while (i < NumArgs-1) { 163 ++i; 164 ++sentinel; 165 } 166 Expr *sentinelExpr = Args[sentinel]; 167 if (!sentinelExpr) return; 168 if (sentinelExpr->isTypeDependent()) return; 169 if (sentinelExpr->isValueDependent()) return; 170 if (sentinelExpr->getType()->isAnyPointerType() && 171 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 172 Expr::NPC_ValueDependentIsNull)) 173 return; 174 175 // Unfortunately, __null has type 'int'. 176 if (isa<GNUNullExpr>(sentinelExpr)) return; 177 178 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 179 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 180} 181 182SourceRange Sema::getExprRange(ExprTy *E) const { 183 Expr *Ex = (Expr *)E; 184 return Ex? Ex->getSourceRange() : SourceRange(); 185} 186 187//===----------------------------------------------------------------------===// 188// Standard Promotions and Conversions 189//===----------------------------------------------------------------------===// 190 191/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 192void Sema::DefaultFunctionArrayConversion(Expr *&E) { 193 QualType Ty = E->getType(); 194 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 195 196 if (Ty->isFunctionType()) 197 ImpCastExprToType(E, Context.getPointerType(Ty), 198 CK_FunctionToPointerDecay); 199 else if (Ty->isArrayType()) { 200 // In C90 mode, arrays only promote to pointers if the array expression is 201 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 202 // type 'array of type' is converted to an expression that has type 'pointer 203 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 204 // that has type 'array of type' ...". The relevant change is "an lvalue" 205 // (C90) to "an expression" (C99). 206 // 207 // C++ 4.2p1: 208 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 209 // T" can be converted to an rvalue of type "pointer to T". 210 // 211 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 212 E->isLvalue(Context) == Expr::LV_Valid) 213 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 214 CK_ArrayToPointerDecay); 215 } 216} 217 218void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 219 DefaultFunctionArrayConversion(E); 220 221 QualType Ty = E->getType(); 222 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 223 if (!Ty->isDependentType() && Ty.hasQualifiers() && 224 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 225 E->isLvalue(Context) == Expr::LV_Valid) { 226 // C++ [conv.lval]p1: 227 // [...] If T is a non-class type, the type of the rvalue is the 228 // cv-unqualified version of T. Otherwise, the type of the 229 // rvalue is T 230 // 231 // C99 6.3.2.1p2: 232 // If the lvalue has qualified type, the value has the unqualified 233 // version of the type of the lvalue; otherwise, the value has the 234 // type of the lvalue. 235 ImpCastExprToType(E, Ty.getUnqualifiedType(), CK_NoOp); 236 } 237} 238 239 240/// UsualUnaryConversions - Performs various conversions that are common to most 241/// operators (C99 6.3). The conversions of array and function types are 242/// sometimes surpressed. For example, the array->pointer conversion doesn't 243/// apply if the array is an argument to the sizeof or address (&) operators. 244/// In these instances, this routine should *not* be called. 245Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 246 QualType Ty = Expr->getType(); 247 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 248 249 // C99 6.3.1.1p2: 250 // 251 // The following may be used in an expression wherever an int or 252 // unsigned int may be used: 253 // - an object or expression with an integer type whose integer 254 // conversion rank is less than or equal to the rank of int 255 // and unsigned int. 256 // - A bit-field of type _Bool, int, signed int, or unsigned int. 257 // 258 // If an int can represent all values of the original type, the 259 // value is converted to an int; otherwise, it is converted to an 260 // unsigned int. These are called the integer promotions. All 261 // other types are unchanged by the integer promotions. 262 QualType PTy = Context.isPromotableBitField(Expr); 263 if (!PTy.isNull()) { 264 ImpCastExprToType(Expr, PTy, CK_IntegralCast); 265 return Expr; 266 } 267 if (Ty->isPromotableIntegerType()) { 268 QualType PT = Context.getPromotedIntegerType(Ty); 269 ImpCastExprToType(Expr, PT, CK_IntegralCast); 270 return Expr; 271 } 272 273 DefaultFunctionArrayLvalueConversion(Expr); 274 return Expr; 275} 276 277/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 278/// do not have a prototype. Arguments that have type float are promoted to 279/// double. All other argument types are converted by UsualUnaryConversions(). 280void Sema::DefaultArgumentPromotion(Expr *&Expr) { 281 QualType Ty = Expr->getType(); 282 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 283 284 // If this is a 'float' (CVR qualified or typedef) promote to double. 285 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 286 return ImpCastExprToType(Expr, Context.DoubleTy, 287 CK_FloatingCast); 288 289 UsualUnaryConversions(Expr); 290} 291 292/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 293/// will warn if the resulting type is not a POD type, and rejects ObjC 294/// interfaces passed by value. This returns true if the argument type is 295/// completely illegal. 296bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 297 FunctionDecl *FDecl) { 298 DefaultArgumentPromotion(Expr); 299 300 // __builtin_va_start takes the second argument as a "varargs" argument, but 301 // it doesn't actually do anything with it. It doesn't need to be non-pod 302 // etc. 303 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 304 return false; 305 306 if (Expr->getType()->isObjCObjectType() && 307 DiagRuntimeBehavior(Expr->getLocStart(), 308 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 309 << Expr->getType() << CT)) 310 return true; 311 312 if (!Expr->getType()->isPODType() && 313 DiagRuntimeBehavior(Expr->getLocStart(), 314 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 315 << Expr->getType() << CT)) 316 return true; 317 318 return false; 319} 320 321 322/// UsualArithmeticConversions - Performs various conversions that are common to 323/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 324/// routine returns the first non-arithmetic type found. The client is 325/// responsible for emitting appropriate error diagnostics. 326/// FIXME: verify the conversion rules for "complex int" are consistent with 327/// GCC. 328QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 329 bool isCompAssign) { 330 if (!isCompAssign) 331 UsualUnaryConversions(lhsExpr); 332 333 UsualUnaryConversions(rhsExpr); 334 335 // For conversion purposes, we ignore any qualifiers. 336 // For example, "const float" and "float" are equivalent. 337 QualType lhs = 338 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 339 QualType rhs = 340 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 341 342 // If both types are identical, no conversion is needed. 343 if (lhs == rhs) 344 return lhs; 345 346 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 347 // The caller can deal with this (e.g. pointer + int). 348 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 349 return lhs; 350 351 // Perform bitfield promotions. 352 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 353 if (!LHSBitfieldPromoteTy.isNull()) 354 lhs = LHSBitfieldPromoteTy; 355 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 356 if (!RHSBitfieldPromoteTy.isNull()) 357 rhs = RHSBitfieldPromoteTy; 358 359 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 360 if (!isCompAssign) 361 ImpCastExprToType(lhsExpr, destType, CK_Unknown); 362 ImpCastExprToType(rhsExpr, destType, CK_Unknown); 363 return destType; 364} 365 366//===----------------------------------------------------------------------===// 367// Semantic Analysis for various Expression Types 368//===----------------------------------------------------------------------===// 369 370 371/// ActOnStringLiteral - The specified tokens were lexed as pasted string 372/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 373/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 374/// multiple tokens. However, the common case is that StringToks points to one 375/// string. 376/// 377ExprResult 378Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 379 assert(NumStringToks && "Must have at least one string!"); 380 381 StringLiteralParser Literal(StringToks, NumStringToks, PP); 382 if (Literal.hadError) 383 return ExprError(); 384 385 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 386 for (unsigned i = 0; i != NumStringToks; ++i) 387 StringTokLocs.push_back(StringToks[i].getLocation()); 388 389 QualType StrTy = Context.CharTy; 390 if (Literal.AnyWide) StrTy = Context.getWCharType(); 391 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 392 393 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 394 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 395 StrTy.addConst(); 396 397 // Get an array type for the string, according to C99 6.4.5. This includes 398 // the nul terminator character as well as the string length for pascal 399 // strings. 400 StrTy = Context.getConstantArrayType(StrTy, 401 llvm::APInt(32, Literal.GetNumStringChars()+1), 402 ArrayType::Normal, 0); 403 404 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 405 return Owned(StringLiteral::Create(Context, Literal.GetString(), 406 Literal.GetStringLength(), 407 Literal.AnyWide, StrTy, 408 &StringTokLocs[0], 409 StringTokLocs.size())); 410} 411 412/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 413/// CurBlock to VD should cause it to be snapshotted (as we do for auto 414/// variables defined outside the block) or false if this is not needed (e.g. 415/// for values inside the block or for globals). 416/// 417/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 418/// up-to-date. 419/// 420static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 421 ValueDecl *VD) { 422 // If the value is defined inside the block, we couldn't snapshot it even if 423 // we wanted to. 424 if (CurBlock->TheDecl == VD->getDeclContext()) 425 return false; 426 427 // If this is an enum constant or function, it is constant, don't snapshot. 428 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 429 return false; 430 431 // If this is a reference to an extern, static, or global variable, no need to 432 // snapshot it. 433 // FIXME: What about 'const' variables in C++? 434 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 435 if (!Var->hasLocalStorage()) 436 return false; 437 438 // Blocks that have these can't be constant. 439 CurBlock->hasBlockDeclRefExprs = true; 440 441 // If we have nested blocks, the decl may be declared in an outer block (in 442 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 443 // be defined outside all of the current blocks (in which case the blocks do 444 // all get the bit). Walk the nesting chain. 445 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 446 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 447 448 if (!NextBlock) 449 continue; 450 451 // If we found the defining block for the variable, don't mark the block as 452 // having a reference outside it. 453 if (NextBlock->TheDecl == VD->getDeclContext()) 454 break; 455 456 // Otherwise, the DeclRef from the inner block causes the outer one to need 457 // a snapshot as well. 458 NextBlock->hasBlockDeclRefExprs = true; 459 } 460 461 return true; 462} 463 464 465ExprResult 466Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, SourceLocation Loc, 467 const CXXScopeSpec *SS) { 468 DeclarationNameInfo NameInfo(D->getDeclName(), Loc); 469 return BuildDeclRefExpr(D, Ty, NameInfo, SS); 470} 471 472/// BuildDeclRefExpr - Build a DeclRefExpr. 473ExprResult 474Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, 475 const DeclarationNameInfo &NameInfo, 476 const CXXScopeSpec *SS) { 477 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 478 Diag(NameInfo.getLoc(), 479 diag::err_auto_variable_cannot_appear_in_own_initializer) 480 << D->getDeclName(); 481 return ExprError(); 482 } 483 484 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 485 if (isa<NonTypeTemplateParmDecl>(VD)) { 486 // Non-type template parameters can be referenced anywhere they are 487 // visible. 488 Ty = Ty.getNonLValueExprType(Context); 489 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 490 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 491 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 492 Diag(NameInfo.getLoc(), 493 diag::err_reference_to_local_var_in_enclosing_function) 494 << D->getIdentifier() << FD->getDeclName(); 495 Diag(D->getLocation(), diag::note_local_variable_declared_here) 496 << D->getIdentifier(); 497 return ExprError(); 498 } 499 } 500 } 501 } 502 503 MarkDeclarationReferenced(NameInfo.getLoc(), D); 504 505 return Owned(DeclRefExpr::Create(Context, 506 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 507 SS? SS->getRange() : SourceRange(), 508 D, NameInfo, Ty)); 509} 510 511/// \brief Given a field that represents a member of an anonymous 512/// struct/union, build the path from that field's context to the 513/// actual member. 514/// 515/// Construct the sequence of field member references we'll have to 516/// perform to get to the field in the anonymous union/struct. The 517/// list of members is built from the field outward, so traverse it 518/// backwards to go from an object in the current context to the field 519/// we found. 520/// 521/// \returns The variable from which the field access should begin, 522/// for an anonymous struct/union that is not a member of another 523/// class. Otherwise, returns NULL. 524VarDecl *Sema::BuildAnonymousStructUnionMemberPath(FieldDecl *Field, 525 llvm::SmallVectorImpl<FieldDecl *> &Path) { 526 assert(Field->getDeclContext()->isRecord() && 527 cast<RecordDecl>(Field->getDeclContext())->isAnonymousStructOrUnion() 528 && "Field must be stored inside an anonymous struct or union"); 529 530 Path.push_back(Field); 531 VarDecl *BaseObject = 0; 532 DeclContext *Ctx = Field->getDeclContext(); 533 do { 534 RecordDecl *Record = cast<RecordDecl>(Ctx); 535 ValueDecl *AnonObject = Record->getAnonymousStructOrUnionObject(); 536 if (FieldDecl *AnonField = dyn_cast<FieldDecl>(AnonObject)) 537 Path.push_back(AnonField); 538 else { 539 BaseObject = cast<VarDecl>(AnonObject); 540 break; 541 } 542 Ctx = Ctx->getParent(); 543 } while (Ctx->isRecord() && 544 cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()); 545 546 return BaseObject; 547} 548 549ExprResult 550Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 551 FieldDecl *Field, 552 Expr *BaseObjectExpr, 553 SourceLocation OpLoc) { 554 llvm::SmallVector<FieldDecl *, 4> AnonFields; 555 VarDecl *BaseObject = BuildAnonymousStructUnionMemberPath(Field, 556 AnonFields); 557 558 // Build the expression that refers to the base object, from 559 // which we will build a sequence of member references to each 560 // of the anonymous union objects and, eventually, the field we 561 // found via name lookup. 562 bool BaseObjectIsPointer = false; 563 Qualifiers BaseQuals; 564 if (BaseObject) { 565 // BaseObject is an anonymous struct/union variable (and is, 566 // therefore, not part of another non-anonymous record). 567 MarkDeclarationReferenced(Loc, BaseObject); 568 BaseObjectExpr = new (Context) DeclRefExpr(BaseObject,BaseObject->getType(), 569 SourceLocation()); 570 BaseQuals 571 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 572 } else if (BaseObjectExpr) { 573 // The caller provided the base object expression. Determine 574 // whether its a pointer and whether it adds any qualifiers to the 575 // anonymous struct/union fields we're looking into. 576 QualType ObjectType = BaseObjectExpr->getType(); 577 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 578 BaseObjectIsPointer = true; 579 ObjectType = ObjectPtr->getPointeeType(); 580 } 581 BaseQuals 582 = Context.getCanonicalType(ObjectType).getQualifiers(); 583 } else { 584 // We've found a member of an anonymous struct/union that is 585 // inside a non-anonymous struct/union, so in a well-formed 586 // program our base object expression is "this". 587 DeclContext *DC = getFunctionLevelDeclContext(); 588 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 589 if (!MD->isStatic()) { 590 QualType AnonFieldType 591 = Context.getTagDeclType( 592 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 593 QualType ThisType = Context.getTagDeclType(MD->getParent()); 594 if ((Context.getCanonicalType(AnonFieldType) 595 == Context.getCanonicalType(ThisType)) || 596 IsDerivedFrom(ThisType, AnonFieldType)) { 597 // Our base object expression is "this". 598 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 599 MD->getThisType(Context), 600 /*isImplicit=*/true); 601 BaseObjectIsPointer = true; 602 } 603 } else { 604 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 605 << Field->getDeclName()); 606 } 607 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 608 } 609 610 if (!BaseObjectExpr) 611 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 612 << Field->getDeclName()); 613 } 614 615 // Build the implicit member references to the field of the 616 // anonymous struct/union. 617 Expr *Result = BaseObjectExpr; 618 Qualifiers ResultQuals = BaseQuals; 619 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 620 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 621 FI != FIEnd; ++FI) { 622 QualType MemberType = (*FI)->getType(); 623 Qualifiers MemberTypeQuals = 624 Context.getCanonicalType(MemberType).getQualifiers(); 625 626 // CVR attributes from the base are picked up by members, 627 // except that 'mutable' members don't pick up 'const'. 628 if ((*FI)->isMutable()) 629 ResultQuals.removeConst(); 630 631 // GC attributes are never picked up by members. 632 ResultQuals.removeObjCGCAttr(); 633 634 // TR 18037 does not allow fields to be declared with address spaces. 635 assert(!MemberTypeQuals.hasAddressSpace()); 636 637 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 638 if (NewQuals != MemberTypeQuals) 639 MemberType = Context.getQualifiedType(MemberType, NewQuals); 640 641 MarkDeclarationReferenced(Loc, *FI); 642 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 643 // FIXME: Might this end up being a qualified name? 644 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 645 OpLoc, MemberType); 646 BaseObjectIsPointer = false; 647 ResultQuals = NewQuals; 648 } 649 650 return Owned(Result); 651} 652 653/// Decomposes the given name into a DeclarationNameInfo, its location, and 654/// possibly a list of template arguments. 655/// 656/// If this produces template arguments, it is permitted to call 657/// DecomposeTemplateName. 658/// 659/// This actually loses a lot of source location information for 660/// non-standard name kinds; we should consider preserving that in 661/// some way. 662static void DecomposeUnqualifiedId(Sema &SemaRef, 663 const UnqualifiedId &Id, 664 TemplateArgumentListInfo &Buffer, 665 DeclarationNameInfo &NameInfo, 666 const TemplateArgumentListInfo *&TemplateArgs) { 667 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 668 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 669 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 670 671 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 672 Id.TemplateId->getTemplateArgs(), 673 Id.TemplateId->NumArgs); 674 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 675 TemplateArgsPtr.release(); 676 677 TemplateName TName = Id.TemplateId->Template.get(); 678 SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; 679 NameInfo = SemaRef.Context.getNameForTemplate(TName, TNameLoc); 680 TemplateArgs = &Buffer; 681 } else { 682 NameInfo = SemaRef.GetNameFromUnqualifiedId(Id); 683 TemplateArgs = 0; 684 } 685} 686 687/// Determines whether the given record is "fully-formed" at the given 688/// location, i.e. whether a qualified lookup into it is assured of 689/// getting consistent results already. 690static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 691 if (!Record->hasDefinition()) 692 return false; 693 694 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 695 E = Record->bases_end(); I != E; ++I) { 696 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 697 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 698 if (!BaseRT) return false; 699 700 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 701 if (!BaseRecord->hasDefinition() || 702 !IsFullyFormedScope(SemaRef, BaseRecord)) 703 return false; 704 } 705 706 return true; 707} 708 709/// Determines if the given class is provably not derived from all of 710/// the prospective base classes. 711static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 712 CXXRecordDecl *Record, 713 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 714 if (Bases.count(Record->getCanonicalDecl())) 715 return false; 716 717 RecordDecl *RD = Record->getDefinition(); 718 if (!RD) return false; 719 Record = cast<CXXRecordDecl>(RD); 720 721 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 722 E = Record->bases_end(); I != E; ++I) { 723 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 724 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 725 if (!BaseRT) return false; 726 727 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 728 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 729 return false; 730 } 731 732 return true; 733} 734 735enum IMAKind { 736 /// The reference is definitely not an instance member access. 737 IMA_Static, 738 739 /// The reference may be an implicit instance member access. 740 IMA_Mixed, 741 742 /// The reference may be to an instance member, but it is invalid if 743 /// so, because the context is not an instance method. 744 IMA_Mixed_StaticContext, 745 746 /// The reference may be to an instance member, but it is invalid if 747 /// so, because the context is from an unrelated class. 748 IMA_Mixed_Unrelated, 749 750 /// The reference is definitely an implicit instance member access. 751 IMA_Instance, 752 753 /// The reference may be to an unresolved using declaration. 754 IMA_Unresolved, 755 756 /// The reference may be to an unresolved using declaration and the 757 /// context is not an instance method. 758 IMA_Unresolved_StaticContext, 759 760 /// The reference is to a member of an anonymous structure in a 761 /// non-class context. 762 IMA_AnonymousMember, 763 764 /// All possible referrents are instance members and the current 765 /// context is not an instance method. 766 IMA_Error_StaticContext, 767 768 /// All possible referrents are instance members of an unrelated 769 /// class. 770 IMA_Error_Unrelated 771}; 772 773/// The given lookup names class member(s) and is not being used for 774/// an address-of-member expression. Classify the type of access 775/// according to whether it's possible that this reference names an 776/// instance member. This is best-effort; it is okay to 777/// conservatively answer "yes", in which case some errors will simply 778/// not be caught until template-instantiation. 779static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 780 const LookupResult &R) { 781 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 782 783 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 784 bool isStaticContext = 785 (!isa<CXXMethodDecl>(DC) || 786 cast<CXXMethodDecl>(DC)->isStatic()); 787 788 if (R.isUnresolvableResult()) 789 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 790 791 // Collect all the declaring classes of instance members we find. 792 bool hasNonInstance = false; 793 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 794 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 795 NamedDecl *D = *I; 796 if (D->isCXXInstanceMember()) { 797 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 798 799 // If this is a member of an anonymous record, move out to the 800 // innermost non-anonymous struct or union. If there isn't one, 801 // that's a special case. 802 while (R->isAnonymousStructOrUnion()) { 803 R = dyn_cast<CXXRecordDecl>(R->getParent()); 804 if (!R) return IMA_AnonymousMember; 805 } 806 Classes.insert(R->getCanonicalDecl()); 807 } 808 else 809 hasNonInstance = true; 810 } 811 812 // If we didn't find any instance members, it can't be an implicit 813 // member reference. 814 if (Classes.empty()) 815 return IMA_Static; 816 817 // If the current context is not an instance method, it can't be 818 // an implicit member reference. 819 if (isStaticContext) 820 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 821 822 // If we can prove that the current context is unrelated to all the 823 // declaring classes, it can't be an implicit member reference (in 824 // which case it's an error if any of those members are selected). 825 if (IsProvablyNotDerivedFrom(SemaRef, 826 cast<CXXMethodDecl>(DC)->getParent(), 827 Classes)) 828 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 829 830 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 831} 832 833/// Diagnose a reference to a field with no object available. 834static void DiagnoseInstanceReference(Sema &SemaRef, 835 const CXXScopeSpec &SS, 836 const LookupResult &R) { 837 SourceLocation Loc = R.getNameLoc(); 838 SourceRange Range(Loc); 839 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 840 841 if (R.getAsSingle<FieldDecl>()) { 842 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 843 if (MD->isStatic()) { 844 // "invalid use of member 'x' in static member function" 845 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 846 << Range << R.getLookupName(); 847 return; 848 } 849 } 850 851 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 852 << R.getLookupName() << Range; 853 return; 854 } 855 856 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 857} 858 859/// Diagnose an empty lookup. 860/// 861/// \return false if new lookup candidates were found 862bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 863 CorrectTypoContext CTC) { 864 DeclarationName Name = R.getLookupName(); 865 866 unsigned diagnostic = diag::err_undeclared_var_use; 867 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 868 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 869 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 870 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 871 diagnostic = diag::err_undeclared_use; 872 diagnostic_suggest = diag::err_undeclared_use_suggest; 873 } 874 875 // If the original lookup was an unqualified lookup, fake an 876 // unqualified lookup. This is useful when (for example) the 877 // original lookup would not have found something because it was a 878 // dependent name. 879 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 880 DC; DC = DC->getParent()) { 881 if (isa<CXXRecordDecl>(DC)) { 882 LookupQualifiedName(R, DC); 883 884 if (!R.empty()) { 885 // Don't give errors about ambiguities in this lookup. 886 R.suppressDiagnostics(); 887 888 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 889 bool isInstance = CurMethod && 890 CurMethod->isInstance() && 891 DC == CurMethod->getParent(); 892 893 // Give a code modification hint to insert 'this->'. 894 // TODO: fixit for inserting 'Base<T>::' in the other cases. 895 // Actually quite difficult! 896 if (isInstance) { 897 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 898 CallsUndergoingInstantiation.back()->getCallee()); 899 CXXMethodDecl *DepMethod = cast_or_null<CXXMethodDecl>( 900 CurMethod->getInstantiatedFromMemberFunction()); 901 if (DepMethod) { 902 Diag(R.getNameLoc(), diagnostic) << Name 903 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 904 QualType DepThisType = DepMethod->getThisType(Context); 905 CXXThisExpr *DepThis = new (Context) CXXThisExpr( 906 R.getNameLoc(), DepThisType, false); 907 TemplateArgumentListInfo TList; 908 if (ULE->hasExplicitTemplateArgs()) 909 ULE->copyTemplateArgumentsInto(TList); 910 CXXDependentScopeMemberExpr *DepExpr = 911 CXXDependentScopeMemberExpr::Create( 912 Context, DepThis, DepThisType, true, SourceLocation(), 913 ULE->getQualifier(), ULE->getQualifierRange(), NULL, 914 R.getLookupNameInfo(), &TList); 915 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 916 } else { 917 // FIXME: we should be able to handle this case too. It is correct 918 // to add this-> here. This is a workaround for PR7947. 919 Diag(R.getNameLoc(), diagnostic) << Name; 920 } 921 } else { 922 Diag(R.getNameLoc(), diagnostic) << Name; 923 } 924 925 // Do we really want to note all of these? 926 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 927 Diag((*I)->getLocation(), diag::note_dependent_var_use); 928 929 // Tell the callee to try to recover. 930 return false; 931 } 932 933 R.clear(); 934 } 935 } 936 937 // We didn't find anything, so try to correct for a typo. 938 DeclarationName Corrected; 939 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 940 if (!R.empty()) { 941 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 942 if (SS.isEmpty()) 943 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 944 << FixItHint::CreateReplacement(R.getNameLoc(), 945 R.getLookupName().getAsString()); 946 else 947 Diag(R.getNameLoc(), diag::err_no_member_suggest) 948 << Name << computeDeclContext(SS, false) << R.getLookupName() 949 << SS.getRange() 950 << FixItHint::CreateReplacement(R.getNameLoc(), 951 R.getLookupName().getAsString()); 952 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 953 Diag(ND->getLocation(), diag::note_previous_decl) 954 << ND->getDeclName(); 955 956 // Tell the callee to try to recover. 957 return false; 958 } 959 960 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 961 // FIXME: If we ended up with a typo for a type name or 962 // Objective-C class name, we're in trouble because the parser 963 // is in the wrong place to recover. Suggest the typo 964 // correction, but don't make it a fix-it since we're not going 965 // to recover well anyway. 966 if (SS.isEmpty()) 967 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 968 else 969 Diag(R.getNameLoc(), diag::err_no_member_suggest) 970 << Name << computeDeclContext(SS, false) << R.getLookupName() 971 << SS.getRange(); 972 973 // Don't try to recover; it won't work. 974 return true; 975 } 976 } else { 977 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 978 // because we aren't able to recover. 979 if (SS.isEmpty()) 980 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 981 else 982 Diag(R.getNameLoc(), diag::err_no_member_suggest) 983 << Name << computeDeclContext(SS, false) << Corrected 984 << SS.getRange(); 985 return true; 986 } 987 R.clear(); 988 } 989 990 // Emit a special diagnostic for failed member lookups. 991 // FIXME: computing the declaration context might fail here (?) 992 if (!SS.isEmpty()) { 993 Diag(R.getNameLoc(), diag::err_no_member) 994 << Name << computeDeclContext(SS, false) 995 << SS.getRange(); 996 return true; 997 } 998 999 // Give up, we can't recover. 1000 Diag(R.getNameLoc(), diagnostic) << Name; 1001 return true; 1002} 1003 1004static ObjCPropertyDecl *OkToSynthesizeProvisionalIvar(Sema &SemaRef, 1005 IdentifierInfo *II, 1006 SourceLocation NameLoc) { 1007 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1008 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1009 if (!IDecl) 1010 return 0; 1011 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1012 if (!ClassImpDecl) 1013 return 0; 1014 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1015 if (!property) 1016 return 0; 1017 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1018 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic) 1019 return 0; 1020 return property; 1021} 1022 1023static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1024 LookupResult &Lookup, 1025 IdentifierInfo *II, 1026 SourceLocation NameLoc) { 1027 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1028 bool LookForIvars; 1029 if (Lookup.empty()) 1030 LookForIvars = true; 1031 else if (CurMeth->isClassMethod()) 1032 LookForIvars = false; 1033 else 1034 LookForIvars = (Lookup.isSingleResult() && 1035 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1036 if (!LookForIvars) 1037 return 0; 1038 1039 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1040 if (!IDecl) 1041 return 0; 1042 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1043 if (!ClassImpDecl) 1044 return 0; 1045 bool DynamicImplSeen = false; 1046 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1047 if (!property) 1048 return 0; 1049 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1050 DynamicImplSeen = 1051 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1052 if (!DynamicImplSeen) { 1053 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1054 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1055 NameLoc, 1056 II, PropType, /*Dinfo=*/0, 1057 ObjCIvarDecl::Protected, 1058 (Expr *)0, true); 1059 ClassImpDecl->addDecl(Ivar); 1060 IDecl->makeDeclVisibleInContext(Ivar, false); 1061 property->setPropertyIvarDecl(Ivar); 1062 return Ivar; 1063 } 1064 return 0; 1065} 1066 1067ExprResult Sema::ActOnIdExpression(Scope *S, 1068 CXXScopeSpec &SS, 1069 UnqualifiedId &Id, 1070 bool HasTrailingLParen, 1071 bool isAddressOfOperand) { 1072 assert(!(isAddressOfOperand && HasTrailingLParen) && 1073 "cannot be direct & operand and have a trailing lparen"); 1074 1075 if (SS.isInvalid()) 1076 return ExprError(); 1077 1078 TemplateArgumentListInfo TemplateArgsBuffer; 1079 1080 // Decompose the UnqualifiedId into the following data. 1081 DeclarationNameInfo NameInfo; 1082 const TemplateArgumentListInfo *TemplateArgs; 1083 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, NameInfo, TemplateArgs); 1084 1085 DeclarationName Name = NameInfo.getName(); 1086 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1087 SourceLocation NameLoc = NameInfo.getLoc(); 1088 1089 // C++ [temp.dep.expr]p3: 1090 // An id-expression is type-dependent if it contains: 1091 // -- an identifier that was declared with a dependent type, 1092 // (note: handled after lookup) 1093 // -- a template-id that is dependent, 1094 // (note: handled in BuildTemplateIdExpr) 1095 // -- a conversion-function-id that specifies a dependent type, 1096 // -- a nested-name-specifier that contains a class-name that 1097 // names a dependent type. 1098 // Determine whether this is a member of an unknown specialization; 1099 // we need to handle these differently. 1100 bool DependentID = false; 1101 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1102 Name.getCXXNameType()->isDependentType()) { 1103 DependentID = true; 1104 } else if (SS.isSet()) { 1105 DeclContext *DC = computeDeclContext(SS, false); 1106 if (DC) { 1107 if (RequireCompleteDeclContext(SS, DC)) 1108 return ExprError(); 1109 // FIXME: We should be checking whether DC is the current instantiation. 1110 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 1111 DependentID = !IsFullyFormedScope(*this, RD); 1112 } else { 1113 DependentID = true; 1114 } 1115 } 1116 1117 if (DependentID) { 1118 return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, 1119 TemplateArgs); 1120 } 1121 bool IvarLookupFollowUp = false; 1122 // Perform the required lookup. 1123 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1124 if (TemplateArgs) { 1125 // Lookup the template name again to correctly establish the context in 1126 // which it was found. This is really unfortunate as we already did the 1127 // lookup to determine that it was a template name in the first place. If 1128 // this becomes a performance hit, we can work harder to preserve those 1129 // results until we get here but it's likely not worth it. 1130 bool MemberOfUnknownSpecialization; 1131 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1132 MemberOfUnknownSpecialization); 1133 } else { 1134 IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1135 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1136 1137 // If this reference is in an Objective-C method, then we need to do 1138 // some special Objective-C lookup, too. 1139 if (IvarLookupFollowUp) { 1140 ExprResult E(LookupInObjCMethod(R, S, II, true)); 1141 if (E.isInvalid()) 1142 return ExprError(); 1143 1144 Expr *Ex = E.takeAs<Expr>(); 1145 if (Ex) return Owned(Ex); 1146 // Synthesize ivars lazily 1147 if (getLangOptions().ObjCNonFragileABI2) { 1148 if (SynthesizeProvisionalIvar(*this, R, II, NameLoc)) 1149 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1150 isAddressOfOperand); 1151 } 1152 // for further use, this must be set to false if in class method. 1153 IvarLookupFollowUp = getCurMethodDecl()->isInstanceMethod(); 1154 } 1155 } 1156 1157 if (R.isAmbiguous()) 1158 return ExprError(); 1159 1160 // Determine whether this name might be a candidate for 1161 // argument-dependent lookup. 1162 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1163 1164 if (R.empty() && !ADL) { 1165 // Otherwise, this could be an implicitly declared function reference (legal 1166 // in C90, extension in C99, forbidden in C++). 1167 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1168 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1169 if (D) R.addDecl(D); 1170 } 1171 1172 // If this name wasn't predeclared and if this is not a function 1173 // call, diagnose the problem. 1174 if (R.empty()) { 1175 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1176 return ExprError(); 1177 1178 assert(!R.empty() && 1179 "DiagnoseEmptyLookup returned false but added no results"); 1180 1181 // If we found an Objective-C instance variable, let 1182 // LookupInObjCMethod build the appropriate expression to 1183 // reference the ivar. 1184 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1185 R.clear(); 1186 ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1187 assert(E.isInvalid() || E.get()); 1188 return move(E); 1189 } 1190 } 1191 } 1192 1193 // This is guaranteed from this point on. 1194 assert(!R.empty() || ADL); 1195 1196 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1197 if (getLangOptions().ObjCNonFragileABI && IvarLookupFollowUp && 1198 !getLangOptions().ObjCNonFragileABI2 && 1199 Var->isFileVarDecl()) { 1200 ObjCPropertyDecl *Property = 1201 OkToSynthesizeProvisionalIvar(*this, II, NameLoc); 1202 if (Property) { 1203 Diag(NameLoc, diag::warn_ivar_variable_conflict) << Var->getDeclName(); 1204 Diag(Property->getLocation(), diag::note_property_declare); 1205 Diag(Var->getLocation(), diag::note_global_declared_at); 1206 } 1207 } 1208 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1209 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1210 // C99 DR 316 says that, if a function type comes from a 1211 // function definition (without a prototype), that type is only 1212 // used for checking compatibility. Therefore, when referencing 1213 // the function, we pretend that we don't have the full function 1214 // type. 1215 if (DiagnoseUseOfDecl(Func, NameLoc)) 1216 return ExprError(); 1217 1218 QualType T = Func->getType(); 1219 QualType NoProtoType = T; 1220 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1221 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1222 Proto->getExtInfo()); 1223 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1224 } 1225 } 1226 1227 // Check whether this might be a C++ implicit instance member access. 1228 // C++ [class.mfct.non-static]p3: 1229 // When an id-expression that is not part of a class member access 1230 // syntax and not used to form a pointer to member is used in the 1231 // body of a non-static member function of class X, if name lookup 1232 // resolves the name in the id-expression to a non-static non-type 1233 // member of some class C, the id-expression is transformed into a 1234 // class member access expression using (*this) as the 1235 // postfix-expression to the left of the . operator. 1236 // 1237 // But we don't actually need to do this for '&' operands if R 1238 // resolved to a function or overloaded function set, because the 1239 // expression is ill-formed if it actually works out to be a 1240 // non-static member function: 1241 // 1242 // C++ [expr.ref]p4: 1243 // Otherwise, if E1.E2 refers to a non-static member function. . . 1244 // [t]he expression can be used only as the left-hand operand of a 1245 // member function call. 1246 // 1247 // There are other safeguards against such uses, but it's important 1248 // to get this right here so that we don't end up making a 1249 // spuriously dependent expression if we're inside a dependent 1250 // instance method. 1251 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1252 bool MightBeImplicitMember; 1253 if (!isAddressOfOperand) 1254 MightBeImplicitMember = true; 1255 else if (!SS.isEmpty()) 1256 MightBeImplicitMember = false; 1257 else if (R.isOverloadedResult()) 1258 MightBeImplicitMember = false; 1259 else if (R.isUnresolvableResult()) 1260 MightBeImplicitMember = true; 1261 else 1262 MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()); 1263 1264 if (MightBeImplicitMember) 1265 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1266 } 1267 1268 if (TemplateArgs) 1269 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1270 1271 return BuildDeclarationNameExpr(SS, R, ADL); 1272} 1273 1274/// Builds an expression which might be an implicit member expression. 1275ExprResult 1276Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1277 LookupResult &R, 1278 const TemplateArgumentListInfo *TemplateArgs) { 1279 switch (ClassifyImplicitMemberAccess(*this, R)) { 1280 case IMA_Instance: 1281 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1282 1283 case IMA_AnonymousMember: 1284 assert(R.isSingleResult()); 1285 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1286 R.getAsSingle<FieldDecl>()); 1287 1288 case IMA_Mixed: 1289 case IMA_Mixed_Unrelated: 1290 case IMA_Unresolved: 1291 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1292 1293 case IMA_Static: 1294 case IMA_Mixed_StaticContext: 1295 case IMA_Unresolved_StaticContext: 1296 if (TemplateArgs) 1297 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1298 return BuildDeclarationNameExpr(SS, R, false); 1299 1300 case IMA_Error_StaticContext: 1301 case IMA_Error_Unrelated: 1302 DiagnoseInstanceReference(*this, SS, R); 1303 return ExprError(); 1304 } 1305 1306 llvm_unreachable("unexpected instance member access kind"); 1307 return ExprError(); 1308} 1309 1310/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1311/// declaration name, generally during template instantiation. 1312/// There's a large number of things which don't need to be done along 1313/// this path. 1314ExprResult 1315Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1316 const DeclarationNameInfo &NameInfo) { 1317 DeclContext *DC; 1318 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1319 return BuildDependentDeclRefExpr(SS, NameInfo, 0); 1320 1321 if (RequireCompleteDeclContext(SS, DC)) 1322 return ExprError(); 1323 1324 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1325 LookupQualifiedName(R, DC); 1326 1327 if (R.isAmbiguous()) 1328 return ExprError(); 1329 1330 if (R.empty()) { 1331 Diag(NameInfo.getLoc(), diag::err_no_member) 1332 << NameInfo.getName() << DC << SS.getRange(); 1333 return ExprError(); 1334 } 1335 1336 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1337} 1338 1339/// LookupInObjCMethod - The parser has read a name in, and Sema has 1340/// detected that we're currently inside an ObjC method. Perform some 1341/// additional lookup. 1342/// 1343/// Ideally, most of this would be done by lookup, but there's 1344/// actually quite a lot of extra work involved. 1345/// 1346/// Returns a null sentinel to indicate trivial success. 1347ExprResult 1348Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1349 IdentifierInfo *II, bool AllowBuiltinCreation) { 1350 SourceLocation Loc = Lookup.getNameLoc(); 1351 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1352 1353 // There are two cases to handle here. 1) scoped lookup could have failed, 1354 // in which case we should look for an ivar. 2) scoped lookup could have 1355 // found a decl, but that decl is outside the current instance method (i.e. 1356 // a global variable). In these two cases, we do a lookup for an ivar with 1357 // this name, if the lookup sucedes, we replace it our current decl. 1358 1359 // If we're in a class method, we don't normally want to look for 1360 // ivars. But if we don't find anything else, and there's an 1361 // ivar, that's an error. 1362 bool IsClassMethod = CurMethod->isClassMethod(); 1363 1364 bool LookForIvars; 1365 if (Lookup.empty()) 1366 LookForIvars = true; 1367 else if (IsClassMethod) 1368 LookForIvars = false; 1369 else 1370 LookForIvars = (Lookup.isSingleResult() && 1371 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1372 ObjCInterfaceDecl *IFace = 0; 1373 if (LookForIvars) { 1374 IFace = CurMethod->getClassInterface(); 1375 ObjCInterfaceDecl *ClassDeclared; 1376 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1377 // Diagnose using an ivar in a class method. 1378 if (IsClassMethod) 1379 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1380 << IV->getDeclName()); 1381 1382 // If we're referencing an invalid decl, just return this as a silent 1383 // error node. The error diagnostic was already emitted on the decl. 1384 if (IV->isInvalidDecl()) 1385 return ExprError(); 1386 1387 // Check if referencing a field with __attribute__((deprecated)). 1388 if (DiagnoseUseOfDecl(IV, Loc)) 1389 return ExprError(); 1390 1391 // Diagnose the use of an ivar outside of the declaring class. 1392 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1393 ClassDeclared != IFace) 1394 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1395 1396 // FIXME: This should use a new expr for a direct reference, don't 1397 // turn this into Self->ivar, just return a BareIVarExpr or something. 1398 IdentifierInfo &II = Context.Idents.get("self"); 1399 UnqualifiedId SelfName; 1400 SelfName.setIdentifier(&II, SourceLocation()); 1401 CXXScopeSpec SelfScopeSpec; 1402 ExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1403 SelfName, false, false); 1404 MarkDeclarationReferenced(Loc, IV); 1405 return Owned(new (Context) 1406 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1407 SelfExpr.takeAs<Expr>(), true, true)); 1408 } 1409 } else if (CurMethod->isInstanceMethod()) { 1410 // We should warn if a local variable hides an ivar. 1411 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1412 ObjCInterfaceDecl *ClassDeclared; 1413 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1414 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1415 IFace == ClassDeclared) 1416 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1417 } 1418 } 1419 1420 if (Lookup.empty() && II && AllowBuiltinCreation) { 1421 // FIXME. Consolidate this with similar code in LookupName. 1422 if (unsigned BuiltinID = II->getBuiltinID()) { 1423 if (!(getLangOptions().CPlusPlus && 1424 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1425 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1426 S, Lookup.isForRedeclaration(), 1427 Lookup.getNameLoc()); 1428 if (D) Lookup.addDecl(D); 1429 } 1430 } 1431 } 1432 // Sentinel value saying that we didn't do anything special. 1433 return Owned((Expr*) 0); 1434} 1435 1436/// \brief Cast a base object to a member's actual type. 1437/// 1438/// Logically this happens in three phases: 1439/// 1440/// * First we cast from the base type to the naming class. 1441/// The naming class is the class into which we were looking 1442/// when we found the member; it's the qualifier type if a 1443/// qualifier was provided, and otherwise it's the base type. 1444/// 1445/// * Next we cast from the naming class to the declaring class. 1446/// If the member we found was brought into a class's scope by 1447/// a using declaration, this is that class; otherwise it's 1448/// the class declaring the member. 1449/// 1450/// * Finally we cast from the declaring class to the "true" 1451/// declaring class of the member. This conversion does not 1452/// obey access control. 1453bool 1454Sema::PerformObjectMemberConversion(Expr *&From, 1455 NestedNameSpecifier *Qualifier, 1456 NamedDecl *FoundDecl, 1457 NamedDecl *Member) { 1458 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1459 if (!RD) 1460 return false; 1461 1462 QualType DestRecordType; 1463 QualType DestType; 1464 QualType FromRecordType; 1465 QualType FromType = From->getType(); 1466 bool PointerConversions = false; 1467 if (isa<FieldDecl>(Member)) { 1468 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1469 1470 if (FromType->getAs<PointerType>()) { 1471 DestType = Context.getPointerType(DestRecordType); 1472 FromRecordType = FromType->getPointeeType(); 1473 PointerConversions = true; 1474 } else { 1475 DestType = DestRecordType; 1476 FromRecordType = FromType; 1477 } 1478 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1479 if (Method->isStatic()) 1480 return false; 1481 1482 DestType = Method->getThisType(Context); 1483 DestRecordType = DestType->getPointeeType(); 1484 1485 if (FromType->getAs<PointerType>()) { 1486 FromRecordType = FromType->getPointeeType(); 1487 PointerConversions = true; 1488 } else { 1489 FromRecordType = FromType; 1490 DestType = DestRecordType; 1491 } 1492 } else { 1493 // No conversion necessary. 1494 return false; 1495 } 1496 1497 if (DestType->isDependentType() || FromType->isDependentType()) 1498 return false; 1499 1500 // If the unqualified types are the same, no conversion is necessary. 1501 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1502 return false; 1503 1504 SourceRange FromRange = From->getSourceRange(); 1505 SourceLocation FromLoc = FromRange.getBegin(); 1506 1507 ExprValueKind VK = CastCategory(From); 1508 1509 // C++ [class.member.lookup]p8: 1510 // [...] Ambiguities can often be resolved by qualifying a name with its 1511 // class name. 1512 // 1513 // If the member was a qualified name and the qualified referred to a 1514 // specific base subobject type, we'll cast to that intermediate type 1515 // first and then to the object in which the member is declared. That allows 1516 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1517 // 1518 // class Base { public: int x; }; 1519 // class Derived1 : public Base { }; 1520 // class Derived2 : public Base { }; 1521 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1522 // 1523 // void VeryDerived::f() { 1524 // x = 17; // error: ambiguous base subobjects 1525 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1526 // } 1527 if (Qualifier) { 1528 QualType QType = QualType(Qualifier->getAsType(), 0); 1529 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1530 assert(QType->isRecordType() && "lookup done with non-record type"); 1531 1532 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1533 1534 // In C++98, the qualifier type doesn't actually have to be a base 1535 // type of the object type, in which case we just ignore it. 1536 // Otherwise build the appropriate casts. 1537 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1538 CXXCastPath BasePath; 1539 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1540 FromLoc, FromRange, &BasePath)) 1541 return true; 1542 1543 if (PointerConversions) 1544 QType = Context.getPointerType(QType); 1545 ImpCastExprToType(From, QType, CK_UncheckedDerivedToBase, 1546 VK, &BasePath); 1547 1548 FromType = QType; 1549 FromRecordType = QRecordType; 1550 1551 // If the qualifier type was the same as the destination type, 1552 // we're done. 1553 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1554 return false; 1555 } 1556 } 1557 1558 bool IgnoreAccess = false; 1559 1560 // If we actually found the member through a using declaration, cast 1561 // down to the using declaration's type. 1562 // 1563 // Pointer equality is fine here because only one declaration of a 1564 // class ever has member declarations. 1565 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1566 assert(isa<UsingShadowDecl>(FoundDecl)); 1567 QualType URecordType = Context.getTypeDeclType( 1568 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1569 1570 // We only need to do this if the naming-class to declaring-class 1571 // conversion is non-trivial. 1572 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1573 assert(IsDerivedFrom(FromRecordType, URecordType)); 1574 CXXCastPath BasePath; 1575 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1576 FromLoc, FromRange, &BasePath)) 1577 return true; 1578 1579 QualType UType = URecordType; 1580 if (PointerConversions) 1581 UType = Context.getPointerType(UType); 1582 ImpCastExprToType(From, UType, CK_UncheckedDerivedToBase, 1583 VK, &BasePath); 1584 FromType = UType; 1585 FromRecordType = URecordType; 1586 } 1587 1588 // We don't do access control for the conversion from the 1589 // declaring class to the true declaring class. 1590 IgnoreAccess = true; 1591 } 1592 1593 CXXCastPath BasePath; 1594 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1595 FromLoc, FromRange, &BasePath, 1596 IgnoreAccess)) 1597 return true; 1598 1599 ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase, 1600 VK, &BasePath); 1601 return false; 1602} 1603 1604/// \brief Build a MemberExpr AST node. 1605static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1606 const CXXScopeSpec &SS, ValueDecl *Member, 1607 DeclAccessPair FoundDecl, 1608 const DeclarationNameInfo &MemberNameInfo, 1609 QualType Ty, 1610 const TemplateArgumentListInfo *TemplateArgs = 0) { 1611 NestedNameSpecifier *Qualifier = 0; 1612 SourceRange QualifierRange; 1613 if (SS.isSet()) { 1614 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1615 QualifierRange = SS.getRange(); 1616 } 1617 1618 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1619 Member, FoundDecl, MemberNameInfo, 1620 TemplateArgs, Ty); 1621} 1622 1623/// Builds an implicit member access expression. The current context 1624/// is known to be an instance method, and the given unqualified lookup 1625/// set is known to contain only instance members, at least one of which 1626/// is from an appropriate type. 1627ExprResult 1628Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1629 LookupResult &R, 1630 const TemplateArgumentListInfo *TemplateArgs, 1631 bool IsKnownInstance) { 1632 assert(!R.empty() && !R.isAmbiguous()); 1633 1634 SourceLocation Loc = R.getNameLoc(); 1635 1636 // We may have found a field within an anonymous union or struct 1637 // (C++ [class.union]). 1638 // FIXME: This needs to happen post-isImplicitMemberReference? 1639 // FIXME: template-ids inside anonymous structs? 1640 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1641 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1642 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1643 1644 // If this is known to be an instance access, go ahead and build a 1645 // 'this' expression now. 1646 DeclContext *DC = getFunctionLevelDeclContext(); 1647 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 1648 Expr *This = 0; // null signifies implicit access 1649 if (IsKnownInstance) { 1650 SourceLocation Loc = R.getNameLoc(); 1651 if (SS.getRange().isValid()) 1652 Loc = SS.getRange().getBegin(); 1653 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1654 } 1655 1656 return BuildMemberReferenceExpr(This, ThisType, 1657 /*OpLoc*/ SourceLocation(), 1658 /*IsArrow*/ true, 1659 SS, 1660 /*FirstQualifierInScope*/ 0, 1661 R, TemplateArgs); 1662} 1663 1664bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1665 const LookupResult &R, 1666 bool HasTrailingLParen) { 1667 // Only when used directly as the postfix-expression of a call. 1668 if (!HasTrailingLParen) 1669 return false; 1670 1671 // Never if a scope specifier was provided. 1672 if (SS.isSet()) 1673 return false; 1674 1675 // Only in C++ or ObjC++. 1676 if (!getLangOptions().CPlusPlus) 1677 return false; 1678 1679 // Turn off ADL when we find certain kinds of declarations during 1680 // normal lookup: 1681 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1682 NamedDecl *D = *I; 1683 1684 // C++0x [basic.lookup.argdep]p3: 1685 // -- a declaration of a class member 1686 // Since using decls preserve this property, we check this on the 1687 // original decl. 1688 if (D->isCXXClassMember()) 1689 return false; 1690 1691 // C++0x [basic.lookup.argdep]p3: 1692 // -- a block-scope function declaration that is not a 1693 // using-declaration 1694 // NOTE: we also trigger this for function templates (in fact, we 1695 // don't check the decl type at all, since all other decl types 1696 // turn off ADL anyway). 1697 if (isa<UsingShadowDecl>(D)) 1698 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1699 else if (D->getDeclContext()->isFunctionOrMethod()) 1700 return false; 1701 1702 // C++0x [basic.lookup.argdep]p3: 1703 // -- a declaration that is neither a function or a function 1704 // template 1705 // And also for builtin functions. 1706 if (isa<FunctionDecl>(D)) { 1707 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1708 1709 // But also builtin functions. 1710 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1711 return false; 1712 } else if (!isa<FunctionTemplateDecl>(D)) 1713 return false; 1714 } 1715 1716 return true; 1717} 1718 1719 1720/// Diagnoses obvious problems with the use of the given declaration 1721/// as an expression. This is only actually called for lookups that 1722/// were not overloaded, and it doesn't promise that the declaration 1723/// will in fact be used. 1724static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1725 if (isa<TypedefDecl>(D)) { 1726 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1727 return true; 1728 } 1729 1730 if (isa<ObjCInterfaceDecl>(D)) { 1731 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1732 return true; 1733 } 1734 1735 if (isa<NamespaceDecl>(D)) { 1736 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1737 return true; 1738 } 1739 1740 return false; 1741} 1742 1743ExprResult 1744Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1745 LookupResult &R, 1746 bool NeedsADL) { 1747 // If this is a single, fully-resolved result and we don't need ADL, 1748 // just build an ordinary singleton decl ref. 1749 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1750 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), 1751 R.getFoundDecl()); 1752 1753 // We only need to check the declaration if there's exactly one 1754 // result, because in the overloaded case the results can only be 1755 // functions and function templates. 1756 if (R.isSingleResult() && 1757 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1758 return ExprError(); 1759 1760 // Otherwise, just build an unresolved lookup expression. Suppress 1761 // any lookup-related diagnostics; we'll hash these out later, when 1762 // we've picked a target. 1763 R.suppressDiagnostics(); 1764 1765 bool Dependent 1766 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1767 UnresolvedLookupExpr *ULE 1768 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1769 (NestedNameSpecifier*) SS.getScopeRep(), 1770 SS.getRange(), R.getLookupNameInfo(), 1771 NeedsADL, R.isOverloadedResult(), 1772 R.begin(), R.end()); 1773 1774 return Owned(ULE); 1775} 1776 1777 1778/// \brief Complete semantic analysis for a reference to the given declaration. 1779ExprResult 1780Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1781 const DeclarationNameInfo &NameInfo, 1782 NamedDecl *D) { 1783 assert(D && "Cannot refer to a NULL declaration"); 1784 assert(!isa<FunctionTemplateDecl>(D) && 1785 "Cannot refer unambiguously to a function template"); 1786 1787 SourceLocation Loc = NameInfo.getLoc(); 1788 if (CheckDeclInExpr(*this, Loc, D)) 1789 return ExprError(); 1790 1791 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1792 // Specifically diagnose references to class templates that are missing 1793 // a template argument list. 1794 Diag(Loc, diag::err_template_decl_ref) 1795 << Template << SS.getRange(); 1796 Diag(Template->getLocation(), diag::note_template_decl_here); 1797 return ExprError(); 1798 } 1799 1800 // Make sure that we're referring to a value. 1801 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1802 if (!VD) { 1803 Diag(Loc, diag::err_ref_non_value) 1804 << D << SS.getRange(); 1805 Diag(D->getLocation(), diag::note_declared_at); 1806 return ExprError(); 1807 } 1808 1809 // Check whether this declaration can be used. Note that we suppress 1810 // this check when we're going to perform argument-dependent lookup 1811 // on this function name, because this might not be the function 1812 // that overload resolution actually selects. 1813 if (DiagnoseUseOfDecl(VD, Loc)) 1814 return ExprError(); 1815 1816 // Only create DeclRefExpr's for valid Decl's. 1817 if (VD->isInvalidDecl()) 1818 return ExprError(); 1819 1820 // If the identifier reference is inside a block, and it refers to a value 1821 // that is outside the block, create a BlockDeclRefExpr instead of a 1822 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1823 // the block is formed. 1824 // 1825 // We do not do this for things like enum constants, global variables, etc, 1826 // as they do not get snapshotted. 1827 // 1828 if (getCurBlock() && 1829 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1830 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1831 Diag(Loc, diag::err_ref_vm_type); 1832 Diag(D->getLocation(), diag::note_declared_at); 1833 return ExprError(); 1834 } 1835 1836 if (VD->getType()->isArrayType()) { 1837 Diag(Loc, diag::err_ref_array_type); 1838 Diag(D->getLocation(), diag::note_declared_at); 1839 return ExprError(); 1840 } 1841 1842 MarkDeclarationReferenced(Loc, VD); 1843 QualType ExprTy = VD->getType().getNonReferenceType(); 1844 // The BlocksAttr indicates the variable is bound by-reference. 1845 if (VD->getAttr<BlocksAttr>()) 1846 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1847 // This is to record that a 'const' was actually synthesize and added. 1848 bool constAdded = !ExprTy.isConstQualified(); 1849 // Variable will be bound by-copy, make it const within the closure. 1850 1851 ExprTy.addConst(); 1852 QualType T = VD->getType(); 1853 BlockDeclRefExpr *BDRE = new (Context) BlockDeclRefExpr(VD, 1854 ExprTy, Loc, false, 1855 constAdded); 1856 if (getLangOptions().CPlusPlus) { 1857 if (!T->isDependentType() && !T->isReferenceType()) { 1858 Expr *E = new (Context) 1859 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 1860 SourceLocation()); 1861 1862 ExprResult Res = PerformCopyInitialization( 1863 InitializedEntity::InitializeBlock(VD->getLocation(), 1864 T, false), 1865 SourceLocation(), 1866 Owned(E)); 1867 if (!Res.isInvalid()) { 1868 Res = MaybeCreateCXXExprWithTemporaries(Res.get()); 1869 Expr *Init = Res.takeAs<Expr>(); 1870 BDRE->setCopyConstructorExpr(Init); 1871 } 1872 } 1873 } 1874 return Owned(BDRE); 1875 } 1876 // If this reference is not in a block or if the referenced variable is 1877 // within the block, create a normal DeclRefExpr. 1878 1879 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), 1880 NameInfo, &SS); 1881} 1882 1883ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1884 tok::TokenKind Kind) { 1885 PredefinedExpr::IdentType IT; 1886 1887 switch (Kind) { 1888 default: assert(0 && "Unknown simple primary expr!"); 1889 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1890 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1891 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1892 } 1893 1894 // Pre-defined identifiers are of type char[x], where x is the length of the 1895 // string. 1896 1897 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1898 if (!currentDecl && getCurBlock()) 1899 currentDecl = getCurBlock()->TheDecl; 1900 if (!currentDecl) { 1901 Diag(Loc, diag::ext_predef_outside_function); 1902 currentDecl = Context.getTranslationUnitDecl(); 1903 } 1904 1905 QualType ResTy; 1906 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1907 ResTy = Context.DependentTy; 1908 } else { 1909 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1910 1911 llvm::APInt LengthI(32, Length + 1); 1912 ResTy = Context.CharTy.withConst(); 1913 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1914 } 1915 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1916} 1917 1918ExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1919 llvm::SmallString<16> CharBuffer; 1920 bool Invalid = false; 1921 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1922 if (Invalid) 1923 return ExprError(); 1924 1925 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1926 PP); 1927 if (Literal.hadError()) 1928 return ExprError(); 1929 1930 QualType Ty; 1931 if (!getLangOptions().CPlusPlus) 1932 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1933 else if (Literal.isWide()) 1934 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1935 else if (Literal.isMultiChar()) 1936 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1937 else 1938 Ty = Context.CharTy; // 'x' -> char in C++ 1939 1940 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1941 Literal.isWide(), 1942 Ty, Tok.getLocation())); 1943} 1944 1945ExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1946 // Fast path for a single digit (which is quite common). A single digit 1947 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1948 if (Tok.getLength() == 1) { 1949 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1950 unsigned IntSize = Context.Target.getIntWidth(); 1951 return Owned(IntegerLiteral::Create(Context, llvm::APInt(IntSize, Val-'0'), 1952 Context.IntTy, Tok.getLocation())); 1953 } 1954 1955 llvm::SmallString<512> IntegerBuffer; 1956 // Add padding so that NumericLiteralParser can overread by one character. 1957 IntegerBuffer.resize(Tok.getLength()+1); 1958 const char *ThisTokBegin = &IntegerBuffer[0]; 1959 1960 // Get the spelling of the token, which eliminates trigraphs, etc. 1961 bool Invalid = false; 1962 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1963 if (Invalid) 1964 return ExprError(); 1965 1966 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1967 Tok.getLocation(), PP); 1968 if (Literal.hadError) 1969 return ExprError(); 1970 1971 Expr *Res; 1972 1973 if (Literal.isFloatingLiteral()) { 1974 QualType Ty; 1975 if (Literal.isFloat) 1976 Ty = Context.FloatTy; 1977 else if (!Literal.isLong) 1978 Ty = Context.DoubleTy; 1979 else 1980 Ty = Context.LongDoubleTy; 1981 1982 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1983 1984 using llvm::APFloat; 1985 APFloat Val(Format); 1986 1987 APFloat::opStatus result = Literal.GetFloatValue(Val); 1988 1989 // Overflow is always an error, but underflow is only an error if 1990 // we underflowed to zero (APFloat reports denormals as underflow). 1991 if ((result & APFloat::opOverflow) || 1992 ((result & APFloat::opUnderflow) && Val.isZero())) { 1993 unsigned diagnostic; 1994 llvm::SmallString<20> buffer; 1995 if (result & APFloat::opOverflow) { 1996 diagnostic = diag::warn_float_overflow; 1997 APFloat::getLargest(Format).toString(buffer); 1998 } else { 1999 diagnostic = diag::warn_float_underflow; 2000 APFloat::getSmallest(Format).toString(buffer); 2001 } 2002 2003 Diag(Tok.getLocation(), diagnostic) 2004 << Ty 2005 << llvm::StringRef(buffer.data(), buffer.size()); 2006 } 2007 2008 bool isExact = (result == APFloat::opOK); 2009 Res = FloatingLiteral::Create(Context, Val, isExact, Ty, Tok.getLocation()); 2010 2011 } else if (!Literal.isIntegerLiteral()) { 2012 return ExprError(); 2013 } else { 2014 QualType Ty; 2015 2016 // long long is a C99 feature. 2017 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 2018 Literal.isLongLong) 2019 Diag(Tok.getLocation(), diag::ext_longlong); 2020 2021 // Get the value in the widest-possible width. 2022 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 2023 2024 if (Literal.GetIntegerValue(ResultVal)) { 2025 // If this value didn't fit into uintmax_t, warn and force to ull. 2026 Diag(Tok.getLocation(), diag::warn_integer_too_large); 2027 Ty = Context.UnsignedLongLongTy; 2028 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 2029 "long long is not intmax_t?"); 2030 } else { 2031 // If this value fits into a ULL, try to figure out what else it fits into 2032 // according to the rules of C99 6.4.4.1p5. 2033 2034 // Octal, Hexadecimal, and integers with a U suffix are allowed to 2035 // be an unsigned int. 2036 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 2037 2038 // Check from smallest to largest, picking the smallest type we can. 2039 unsigned Width = 0; 2040 if (!Literal.isLong && !Literal.isLongLong) { 2041 // Are int/unsigned possibilities? 2042 unsigned IntSize = Context.Target.getIntWidth(); 2043 2044 // Does it fit in a unsigned int? 2045 if (ResultVal.isIntN(IntSize)) { 2046 // Does it fit in a signed int? 2047 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 2048 Ty = Context.IntTy; 2049 else if (AllowUnsigned) 2050 Ty = Context.UnsignedIntTy; 2051 Width = IntSize; 2052 } 2053 } 2054 2055 // Are long/unsigned long possibilities? 2056 if (Ty.isNull() && !Literal.isLongLong) { 2057 unsigned LongSize = Context.Target.getLongWidth(); 2058 2059 // Does it fit in a unsigned long? 2060 if (ResultVal.isIntN(LongSize)) { 2061 // Does it fit in a signed long? 2062 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 2063 Ty = Context.LongTy; 2064 else if (AllowUnsigned) 2065 Ty = Context.UnsignedLongTy; 2066 Width = LongSize; 2067 } 2068 } 2069 2070 // Finally, check long long if needed. 2071 if (Ty.isNull()) { 2072 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2073 2074 // Does it fit in a unsigned long long? 2075 if (ResultVal.isIntN(LongLongSize)) { 2076 // Does it fit in a signed long long? 2077 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 2078 Ty = Context.LongLongTy; 2079 else if (AllowUnsigned) 2080 Ty = Context.UnsignedLongLongTy; 2081 Width = LongLongSize; 2082 } 2083 } 2084 2085 // If we still couldn't decide a type, we probably have something that 2086 // does not fit in a signed long long, but has no U suffix. 2087 if (Ty.isNull()) { 2088 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2089 Ty = Context.UnsignedLongLongTy; 2090 Width = Context.Target.getLongLongWidth(); 2091 } 2092 2093 if (ResultVal.getBitWidth() != Width) 2094 ResultVal.trunc(Width); 2095 } 2096 Res = IntegerLiteral::Create(Context, ResultVal, Ty, Tok.getLocation()); 2097 } 2098 2099 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2100 if (Literal.isImaginary) 2101 Res = new (Context) ImaginaryLiteral(Res, 2102 Context.getComplexType(Res->getType())); 2103 2104 return Owned(Res); 2105} 2106 2107ExprResult Sema::ActOnParenExpr(SourceLocation L, 2108 SourceLocation R, Expr *E) { 2109 assert((E != 0) && "ActOnParenExpr() missing expr"); 2110 return Owned(new (Context) ParenExpr(L, R, E)); 2111} 2112 2113/// The UsualUnaryConversions() function is *not* called by this routine. 2114/// See C99 6.3.2.1p[2-4] for more details. 2115bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2116 SourceLocation OpLoc, 2117 const SourceRange &ExprRange, 2118 bool isSizeof) { 2119 if (exprType->isDependentType()) 2120 return false; 2121 2122 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2123 // the result is the size of the referenced type." 2124 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2125 // result shall be the alignment of the referenced type." 2126 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2127 exprType = Ref->getPointeeType(); 2128 2129 // C99 6.5.3.4p1: 2130 if (exprType->isFunctionType()) { 2131 // alignof(function) is allowed as an extension. 2132 if (isSizeof) 2133 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2134 return false; 2135 } 2136 2137 // Allow sizeof(void)/alignof(void) as an extension. 2138 if (exprType->isVoidType()) { 2139 Diag(OpLoc, diag::ext_sizeof_void_type) 2140 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2141 return false; 2142 } 2143 2144 if (RequireCompleteType(OpLoc, exprType, 2145 PDiag(diag::err_sizeof_alignof_incomplete_type) 2146 << int(!isSizeof) << ExprRange)) 2147 return true; 2148 2149 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2150 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2151 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2152 << exprType << isSizeof << ExprRange; 2153 return true; 2154 } 2155 2156 if (Context.hasSameUnqualifiedType(exprType, Context.OverloadTy)) { 2157 Diag(OpLoc, diag::err_sizeof_alignof_overloaded_function_type) 2158 << !isSizeof << ExprRange; 2159 return true; 2160 } 2161 2162 return false; 2163} 2164 2165bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2166 const SourceRange &ExprRange) { 2167 E = E->IgnoreParens(); 2168 2169 // alignof decl is always ok. 2170 if (isa<DeclRefExpr>(E)) 2171 return false; 2172 2173 // Cannot know anything else if the expression is dependent. 2174 if (E->isTypeDependent()) 2175 return false; 2176 2177 if (E->getBitField()) { 2178 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2179 return true; 2180 } 2181 2182 // Alignment of a field access is always okay, so long as it isn't a 2183 // bit-field. 2184 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2185 if (isa<FieldDecl>(ME->getMemberDecl())) 2186 return false; 2187 2188 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2189} 2190 2191/// \brief Build a sizeof or alignof expression given a type operand. 2192ExprResult 2193Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2194 SourceLocation OpLoc, 2195 bool isSizeOf, SourceRange R) { 2196 if (!TInfo) 2197 return ExprError(); 2198 2199 QualType T = TInfo->getType(); 2200 2201 if (!T->isDependentType() && 2202 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2203 return ExprError(); 2204 2205 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2206 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2207 Context.getSizeType(), OpLoc, 2208 R.getEnd())); 2209} 2210 2211/// \brief Build a sizeof or alignof expression given an expression 2212/// operand. 2213ExprResult 2214Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2215 bool isSizeOf, SourceRange R) { 2216 // Verify that the operand is valid. 2217 bool isInvalid = false; 2218 if (E->isTypeDependent()) { 2219 // Delay type-checking for type-dependent expressions. 2220 } else if (!isSizeOf) { 2221 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2222 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2223 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2224 isInvalid = true; 2225 } else { 2226 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2227 } 2228 2229 if (isInvalid) 2230 return ExprError(); 2231 2232 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2233 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2234 Context.getSizeType(), OpLoc, 2235 R.getEnd())); 2236} 2237 2238/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2239/// the same for @c alignof and @c __alignof 2240/// Note that the ArgRange is invalid if isType is false. 2241ExprResult 2242Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2243 void *TyOrEx, const SourceRange &ArgRange) { 2244 // If error parsing type, ignore. 2245 if (TyOrEx == 0) return ExprError(); 2246 2247 if (isType) { 2248 TypeSourceInfo *TInfo; 2249 (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); 2250 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2251 } 2252 2253 Expr *ArgEx = (Expr *)TyOrEx; 2254 ExprResult Result 2255 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2256 2257 if (Result.isInvalid()) 2258 DeleteExpr(ArgEx); 2259 2260 return move(Result); 2261} 2262 2263QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2264 if (V->isTypeDependent()) 2265 return Context.DependentTy; 2266 2267 // These operators return the element type of a complex type. 2268 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2269 return CT->getElementType(); 2270 2271 // Otherwise they pass through real integer and floating point types here. 2272 if (V->getType()->isArithmeticType()) 2273 return V->getType(); 2274 2275 // Reject anything else. 2276 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2277 << (isReal ? "__real" : "__imag"); 2278 return QualType(); 2279} 2280 2281 2282 2283ExprResult 2284Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2285 tok::TokenKind Kind, Expr *Input) { 2286 UnaryOperatorKind Opc; 2287 switch (Kind) { 2288 default: assert(0 && "Unknown unary op!"); 2289 case tok::plusplus: Opc = UO_PostInc; break; 2290 case tok::minusminus: Opc = UO_PostDec; break; 2291 } 2292 2293 return BuildUnaryOp(S, OpLoc, Opc, Input); 2294} 2295 2296ExprResult 2297Sema::ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc, 2298 Expr *Idx, SourceLocation RLoc) { 2299 // Since this might be a postfix expression, get rid of ParenListExprs. 2300 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 2301 if (Result.isInvalid()) return ExprError(); 2302 Base = Result.take(); 2303 2304 Expr *LHSExp = Base, *RHSExp = Idx; 2305 2306 if (getLangOptions().CPlusPlus && 2307 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2308 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2309 Context.DependentTy, RLoc)); 2310 } 2311 2312 if (getLangOptions().CPlusPlus && 2313 (LHSExp->getType()->isRecordType() || 2314 LHSExp->getType()->isEnumeralType() || 2315 RHSExp->getType()->isRecordType() || 2316 RHSExp->getType()->isEnumeralType())) { 2317 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, Base, Idx); 2318 } 2319 2320 return CreateBuiltinArraySubscriptExpr(Base, LLoc, Idx, RLoc); 2321} 2322 2323 2324ExprResult 2325Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, 2326 Expr *Idx, SourceLocation RLoc) { 2327 Expr *LHSExp = Base; 2328 Expr *RHSExp = Idx; 2329 2330 // Perform default conversions. 2331 if (!LHSExp->getType()->getAs<VectorType>()) 2332 DefaultFunctionArrayLvalueConversion(LHSExp); 2333 DefaultFunctionArrayLvalueConversion(RHSExp); 2334 2335 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2336 2337 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2338 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2339 // in the subscript position. As a result, we need to derive the array base 2340 // and index from the expression types. 2341 Expr *BaseExpr, *IndexExpr; 2342 QualType ResultType; 2343 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2344 BaseExpr = LHSExp; 2345 IndexExpr = RHSExp; 2346 ResultType = Context.DependentTy; 2347 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2348 BaseExpr = LHSExp; 2349 IndexExpr = RHSExp; 2350 ResultType = PTy->getPointeeType(); 2351 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2352 // Handle the uncommon case of "123[Ptr]". 2353 BaseExpr = RHSExp; 2354 IndexExpr = LHSExp; 2355 ResultType = PTy->getPointeeType(); 2356 } else if (const ObjCObjectPointerType *PTy = 2357 LHSTy->getAs<ObjCObjectPointerType>()) { 2358 BaseExpr = LHSExp; 2359 IndexExpr = RHSExp; 2360 ResultType = PTy->getPointeeType(); 2361 } else if (const ObjCObjectPointerType *PTy = 2362 RHSTy->getAs<ObjCObjectPointerType>()) { 2363 // Handle the uncommon case of "123[Ptr]". 2364 BaseExpr = RHSExp; 2365 IndexExpr = LHSExp; 2366 ResultType = PTy->getPointeeType(); 2367 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2368 BaseExpr = LHSExp; // vectors: V[123] 2369 IndexExpr = RHSExp; 2370 2371 // FIXME: need to deal with const... 2372 ResultType = VTy->getElementType(); 2373 } else if (LHSTy->isArrayType()) { 2374 // If we see an array that wasn't promoted by 2375 // DefaultFunctionArrayLvalueConversion, it must be an array that 2376 // wasn't promoted because of the C90 rule that doesn't 2377 // allow promoting non-lvalue arrays. Warn, then 2378 // force the promotion here. 2379 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2380 LHSExp->getSourceRange(); 2381 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2382 CK_ArrayToPointerDecay); 2383 LHSTy = LHSExp->getType(); 2384 2385 BaseExpr = LHSExp; 2386 IndexExpr = RHSExp; 2387 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2388 } else if (RHSTy->isArrayType()) { 2389 // Same as previous, except for 123[f().a] case 2390 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2391 RHSExp->getSourceRange(); 2392 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2393 CK_ArrayToPointerDecay); 2394 RHSTy = RHSExp->getType(); 2395 2396 BaseExpr = RHSExp; 2397 IndexExpr = LHSExp; 2398 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2399 } else { 2400 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2401 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2402 } 2403 // C99 6.5.2.1p1 2404 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) 2405 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2406 << IndexExpr->getSourceRange()); 2407 2408 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2409 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2410 && !IndexExpr->isTypeDependent()) 2411 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2412 2413 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2414 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2415 // type. Note that Functions are not objects, and that (in C99 parlance) 2416 // incomplete types are not object types. 2417 if (ResultType->isFunctionType()) { 2418 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2419 << ResultType << BaseExpr->getSourceRange(); 2420 return ExprError(); 2421 } 2422 2423 if (!ResultType->isDependentType() && 2424 RequireCompleteType(LLoc, ResultType, 2425 PDiag(diag::err_subscript_incomplete_type) 2426 << BaseExpr->getSourceRange())) 2427 return ExprError(); 2428 2429 // Diagnose bad cases where we step over interface counts. 2430 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2431 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2432 << ResultType << BaseExpr->getSourceRange(); 2433 return ExprError(); 2434 } 2435 2436 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2437 ResultType, RLoc)); 2438} 2439 2440QualType Sema:: 2441CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2442 const IdentifierInfo *CompName, 2443 SourceLocation CompLoc) { 2444 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2445 // see FIXME there. 2446 // 2447 // FIXME: This logic can be greatly simplified by splitting it along 2448 // halving/not halving and reworking the component checking. 2449 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2450 2451 // The vector accessor can't exceed the number of elements. 2452 const char *compStr = CompName->getNameStart(); 2453 2454 // This flag determines whether or not the component is one of the four 2455 // special names that indicate a subset of exactly half the elements are 2456 // to be selected. 2457 bool HalvingSwizzle = false; 2458 2459 // This flag determines whether or not CompName has an 's' char prefix, 2460 // indicating that it is a string of hex values to be used as vector indices. 2461 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2462 2463 // Check that we've found one of the special components, or that the component 2464 // names must come from the same set. 2465 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2466 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2467 HalvingSwizzle = true; 2468 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2469 do 2470 compStr++; 2471 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2472 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2473 do 2474 compStr++; 2475 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2476 } 2477 2478 if (!HalvingSwizzle && *compStr) { 2479 // We didn't get to the end of the string. This means the component names 2480 // didn't come from the same set *or* we encountered an illegal name. 2481 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2482 << llvm::StringRef(compStr, 1) << SourceRange(CompLoc); 2483 return QualType(); 2484 } 2485 2486 // Ensure no component accessor exceeds the width of the vector type it 2487 // operates on. 2488 if (!HalvingSwizzle) { 2489 compStr = CompName->getNameStart(); 2490 2491 if (HexSwizzle) 2492 compStr++; 2493 2494 while (*compStr) { 2495 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2496 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2497 << baseType << SourceRange(CompLoc); 2498 return QualType(); 2499 } 2500 } 2501 } 2502 2503 // The component accessor looks fine - now we need to compute the actual type. 2504 // The vector type is implied by the component accessor. For example, 2505 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2506 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2507 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2508 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2509 : CompName->getLength(); 2510 if (HexSwizzle) 2511 CompSize--; 2512 2513 if (CompSize == 1) 2514 return vecType->getElementType(); 2515 2516 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2517 // Now look up the TypeDefDecl from the vector type. Without this, 2518 // diagostics look bad. We want extended vector types to appear built-in. 2519 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2520 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2521 return Context.getTypedefType(ExtVectorDecls[i]); 2522 } 2523 return VT; // should never get here (a typedef type should always be found). 2524} 2525 2526static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2527 IdentifierInfo *Member, 2528 const Selector &Sel, 2529 ASTContext &Context) { 2530 2531 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2532 return PD; 2533 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2534 return OMD; 2535 2536 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2537 E = PDecl->protocol_end(); I != E; ++I) { 2538 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2539 Context)) 2540 return D; 2541 } 2542 return 0; 2543} 2544 2545static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2546 IdentifierInfo *Member, 2547 const Selector &Sel, 2548 ASTContext &Context) { 2549 // Check protocols on qualified interfaces. 2550 Decl *GDecl = 0; 2551 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2552 E = QIdTy->qual_end(); I != E; ++I) { 2553 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2554 GDecl = PD; 2555 break; 2556 } 2557 // Also must look for a getter name which uses property syntax. 2558 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2559 GDecl = OMD; 2560 break; 2561 } 2562 } 2563 if (!GDecl) { 2564 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2565 E = QIdTy->qual_end(); I != E; ++I) { 2566 // Search in the protocol-qualifier list of current protocol. 2567 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2568 if (GDecl) 2569 return GDecl; 2570 } 2571 } 2572 return GDecl; 2573} 2574 2575ExprResult 2576Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, 2577 bool IsArrow, SourceLocation OpLoc, 2578 const CXXScopeSpec &SS, 2579 NamedDecl *FirstQualifierInScope, 2580 const DeclarationNameInfo &NameInfo, 2581 const TemplateArgumentListInfo *TemplateArgs) { 2582 // Even in dependent contexts, try to diagnose base expressions with 2583 // obviously wrong types, e.g.: 2584 // 2585 // T* t; 2586 // t.f; 2587 // 2588 // In Obj-C++, however, the above expression is valid, since it could be 2589 // accessing the 'f' property if T is an Obj-C interface. The extra check 2590 // allows this, while still reporting an error if T is a struct pointer. 2591 if (!IsArrow) { 2592 const PointerType *PT = BaseType->getAs<PointerType>(); 2593 if (PT && (!getLangOptions().ObjC1 || 2594 PT->getPointeeType()->isRecordType())) { 2595 assert(BaseExpr && "cannot happen with implicit member accesses"); 2596 Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) 2597 << BaseType << BaseExpr->getSourceRange(); 2598 return ExprError(); 2599 } 2600 } 2601 2602 assert(BaseType->isDependentType() || 2603 NameInfo.getName().isDependentName() || 2604 isDependentScopeSpecifier(SS)); 2605 2606 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2607 // must have pointer type, and the accessed type is the pointee. 2608 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2609 IsArrow, OpLoc, 2610 SS.getScopeRep(), 2611 SS.getRange(), 2612 FirstQualifierInScope, 2613 NameInfo, TemplateArgs)); 2614} 2615 2616/// We know that the given qualified member reference points only to 2617/// declarations which do not belong to the static type of the base 2618/// expression. Diagnose the problem. 2619static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2620 Expr *BaseExpr, 2621 QualType BaseType, 2622 const CXXScopeSpec &SS, 2623 const LookupResult &R) { 2624 // If this is an implicit member access, use a different set of 2625 // diagnostics. 2626 if (!BaseExpr) 2627 return DiagnoseInstanceReference(SemaRef, SS, R); 2628 2629 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 2630 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 2631} 2632 2633// Check whether the declarations we found through a nested-name 2634// specifier in a member expression are actually members of the base 2635// type. The restriction here is: 2636// 2637// C++ [expr.ref]p2: 2638// ... In these cases, the id-expression shall name a 2639// member of the class or of one of its base classes. 2640// 2641// So it's perfectly legitimate for the nested-name specifier to name 2642// an unrelated class, and for us to find an overload set including 2643// decls from classes which are not superclasses, as long as the decl 2644// we actually pick through overload resolution is from a superclass. 2645bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2646 QualType BaseType, 2647 const CXXScopeSpec &SS, 2648 const LookupResult &R) { 2649 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2650 if (!BaseRT) { 2651 // We can't check this yet because the base type is still 2652 // dependent. 2653 assert(BaseType->isDependentType()); 2654 return false; 2655 } 2656 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2657 2658 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2659 // If this is an implicit member reference and we find a 2660 // non-instance member, it's not an error. 2661 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2662 return false; 2663 2664 // Note that we use the DC of the decl, not the underlying decl. 2665 DeclContext *DC = (*I)->getDeclContext(); 2666 while (DC->isTransparentContext()) 2667 DC = DC->getParent(); 2668 2669 if (!DC->isRecord()) 2670 continue; 2671 2672 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2673 MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); 2674 2675 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2676 return false; 2677 } 2678 2679 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2680 return true; 2681} 2682 2683static bool 2684LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2685 SourceRange BaseRange, const RecordType *RTy, 2686 SourceLocation OpLoc, CXXScopeSpec &SS, 2687 bool HasTemplateArgs) { 2688 RecordDecl *RDecl = RTy->getDecl(); 2689 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2690 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2691 << BaseRange)) 2692 return true; 2693 2694 if (HasTemplateArgs) { 2695 // LookupTemplateName doesn't expect these both to exist simultaneously. 2696 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 2697 2698 bool MOUS; 2699 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 2700 return false; 2701 } 2702 2703 DeclContext *DC = RDecl; 2704 if (SS.isSet()) { 2705 // If the member name was a qualified-id, look into the 2706 // nested-name-specifier. 2707 DC = SemaRef.computeDeclContext(SS, false); 2708 2709 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 2710 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2711 << SS.getRange() << DC; 2712 return true; 2713 } 2714 2715 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2716 2717 if (!isa<TypeDecl>(DC)) { 2718 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2719 << DC << SS.getRange(); 2720 return true; 2721 } 2722 } 2723 2724 // The record definition is complete, now look up the member. 2725 SemaRef.LookupQualifiedName(R, DC); 2726 2727 if (!R.empty()) 2728 return false; 2729 2730 // We didn't find anything with the given name, so try to correct 2731 // for typos. 2732 DeclarationName Name = R.getLookupName(); 2733 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 2734 !R.empty() && 2735 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2736 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2737 << Name << DC << R.getLookupName() << SS.getRange() 2738 << FixItHint::CreateReplacement(R.getNameLoc(), 2739 R.getLookupName().getAsString()); 2740 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2741 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2742 << ND->getDeclName(); 2743 return false; 2744 } else { 2745 R.clear(); 2746 R.setLookupName(Name); 2747 } 2748 2749 return false; 2750} 2751 2752ExprResult 2753Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, 2754 SourceLocation OpLoc, bool IsArrow, 2755 CXXScopeSpec &SS, 2756 NamedDecl *FirstQualifierInScope, 2757 const DeclarationNameInfo &NameInfo, 2758 const TemplateArgumentListInfo *TemplateArgs) { 2759 if (BaseType->isDependentType() || 2760 (SS.isSet() && isDependentScopeSpecifier(SS))) 2761 return ActOnDependentMemberExpr(Base, BaseType, 2762 IsArrow, OpLoc, 2763 SS, FirstQualifierInScope, 2764 NameInfo, TemplateArgs); 2765 2766 LookupResult R(*this, NameInfo, LookupMemberName); 2767 2768 // Implicit member accesses. 2769 if (!Base) { 2770 QualType RecordTy = BaseType; 2771 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2772 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2773 RecordTy->getAs<RecordType>(), 2774 OpLoc, SS, TemplateArgs != 0)) 2775 return ExprError(); 2776 2777 // Explicit member accesses. 2778 } else { 2779 ExprResult Result = 2780 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2781 SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); 2782 2783 if (Result.isInvalid()) { 2784 Owned(Base); 2785 return ExprError(); 2786 } 2787 2788 if (Result.get()) 2789 return move(Result); 2790 2791 // LookupMemberExpr can modify Base, and thus change BaseType 2792 BaseType = Base->getType(); 2793 } 2794 2795 return BuildMemberReferenceExpr(Base, BaseType, 2796 OpLoc, IsArrow, SS, FirstQualifierInScope, 2797 R, TemplateArgs); 2798} 2799 2800ExprResult 2801Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, 2802 SourceLocation OpLoc, bool IsArrow, 2803 const CXXScopeSpec &SS, 2804 NamedDecl *FirstQualifierInScope, 2805 LookupResult &R, 2806 const TemplateArgumentListInfo *TemplateArgs, 2807 bool SuppressQualifierCheck) { 2808 QualType BaseType = BaseExprType; 2809 if (IsArrow) { 2810 assert(BaseType->isPointerType()); 2811 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2812 } 2813 R.setBaseObjectType(BaseType); 2814 2815 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 2816 const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); 2817 DeclarationName MemberName = MemberNameInfo.getName(); 2818 SourceLocation MemberLoc = MemberNameInfo.getLoc(); 2819 2820 if (R.isAmbiguous()) 2821 return ExprError(); 2822 2823 if (R.empty()) { 2824 // Rederive where we looked up. 2825 DeclContext *DC = (SS.isSet() 2826 ? computeDeclContext(SS, false) 2827 : BaseType->getAs<RecordType>()->getDecl()); 2828 2829 Diag(R.getNameLoc(), diag::err_no_member) 2830 << MemberName << DC 2831 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2832 return ExprError(); 2833 } 2834 2835 // Diagnose lookups that find only declarations from a non-base 2836 // type. This is possible for either qualified lookups (which may 2837 // have been qualified with an unrelated type) or implicit member 2838 // expressions (which were found with unqualified lookup and thus 2839 // may have come from an enclosing scope). Note that it's okay for 2840 // lookup to find declarations from a non-base type as long as those 2841 // aren't the ones picked by overload resolution. 2842 if ((SS.isSet() || !BaseExpr || 2843 (isa<CXXThisExpr>(BaseExpr) && 2844 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2845 !SuppressQualifierCheck && 2846 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2847 return ExprError(); 2848 2849 // Construct an unresolved result if we in fact got an unresolved 2850 // result. 2851 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2852 bool Dependent = 2853 BaseExprType->isDependentType() || 2854 R.isUnresolvableResult() || 2855 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2856 2857 // Suppress any lookup-related diagnostics; we'll do these when we 2858 // pick a member. 2859 R.suppressDiagnostics(); 2860 2861 UnresolvedMemberExpr *MemExpr 2862 = UnresolvedMemberExpr::Create(Context, Dependent, 2863 R.isUnresolvableResult(), 2864 BaseExpr, BaseExprType, 2865 IsArrow, OpLoc, 2866 Qualifier, SS.getRange(), 2867 MemberNameInfo, 2868 TemplateArgs, R.begin(), R.end()); 2869 2870 return Owned(MemExpr); 2871 } 2872 2873 assert(R.isSingleResult()); 2874 DeclAccessPair FoundDecl = R.begin().getPair(); 2875 NamedDecl *MemberDecl = R.getFoundDecl(); 2876 2877 // FIXME: diagnose the presence of template arguments now. 2878 2879 // If the decl being referenced had an error, return an error for this 2880 // sub-expr without emitting another error, in order to avoid cascading 2881 // error cases. 2882 if (MemberDecl->isInvalidDecl()) 2883 return ExprError(); 2884 2885 // Handle the implicit-member-access case. 2886 if (!BaseExpr) { 2887 // If this is not an instance member, convert to a non-member access. 2888 if (!MemberDecl->isCXXInstanceMember()) 2889 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); 2890 2891 SourceLocation Loc = R.getNameLoc(); 2892 if (SS.getRange().isValid()) 2893 Loc = SS.getRange().getBegin(); 2894 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2895 } 2896 2897 bool ShouldCheckUse = true; 2898 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2899 // Don't diagnose the use of a virtual member function unless it's 2900 // explicitly qualified. 2901 if (MD->isVirtual() && !SS.isSet()) 2902 ShouldCheckUse = false; 2903 } 2904 2905 // Check the use of this member. 2906 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2907 Owned(BaseExpr); 2908 return ExprError(); 2909 } 2910 2911 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2912 // We may have found a field within an anonymous union or struct 2913 // (C++ [class.union]). 2914 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2915 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2916 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2917 BaseExpr, OpLoc); 2918 2919 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2920 QualType MemberType = FD->getType(); 2921 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2922 MemberType = Ref->getPointeeType(); 2923 else { 2924 Qualifiers BaseQuals = BaseType.getQualifiers(); 2925 BaseQuals.removeObjCGCAttr(); 2926 if (FD->isMutable()) BaseQuals.removeConst(); 2927 2928 Qualifiers MemberQuals 2929 = Context.getCanonicalType(MemberType).getQualifiers(); 2930 2931 Qualifiers Combined = BaseQuals + MemberQuals; 2932 if (Combined != MemberQuals) 2933 MemberType = Context.getQualifiedType(MemberType, Combined); 2934 } 2935 2936 MarkDeclarationReferenced(MemberLoc, FD); 2937 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2938 return ExprError(); 2939 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2940 FD, FoundDecl, MemberNameInfo, 2941 MemberType)); 2942 } 2943 2944 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2945 MarkDeclarationReferenced(MemberLoc, Var); 2946 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2947 Var, FoundDecl, MemberNameInfo, 2948 Var->getType().getNonReferenceType())); 2949 } 2950 2951 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2952 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2953 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2954 MemberFn, FoundDecl, MemberNameInfo, 2955 MemberFn->getType())); 2956 } 2957 2958 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2959 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2960 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2961 Enum, FoundDecl, MemberNameInfo, 2962 Enum->getType())); 2963 } 2964 2965 Owned(BaseExpr); 2966 2967 // We found something that we didn't expect. Complain. 2968 if (isa<TypeDecl>(MemberDecl)) 2969 Diag(MemberLoc, diag::err_typecheck_member_reference_type) 2970 << MemberName << BaseType << int(IsArrow); 2971 else 2972 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 2973 << MemberName << BaseType << int(IsArrow); 2974 2975 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 2976 << MemberName; 2977 R.suppressDiagnostics(); 2978 return ExprError(); 2979} 2980 2981/// Look up the given member of the given non-type-dependent 2982/// expression. This can return in one of two ways: 2983/// * If it returns a sentinel null-but-valid result, the caller will 2984/// assume that lookup was performed and the results written into 2985/// the provided structure. It will take over from there. 2986/// * Otherwise, the returned expression will be produced in place of 2987/// an ordinary member expression. 2988/// 2989/// The ObjCImpDecl bit is a gross hack that will need to be properly 2990/// fixed for ObjC++. 2991ExprResult 2992Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2993 bool &IsArrow, SourceLocation OpLoc, 2994 CXXScopeSpec &SS, 2995 Decl *ObjCImpDecl, bool HasTemplateArgs) { 2996 assert(BaseExpr && "no base expression"); 2997 2998 // Perform default conversions. 2999 DefaultFunctionArrayConversion(BaseExpr); 3000 3001 QualType BaseType = BaseExpr->getType(); 3002 assert(!BaseType->isDependentType()); 3003 3004 DeclarationName MemberName = R.getLookupName(); 3005 SourceLocation MemberLoc = R.getNameLoc(); 3006 3007 // If the user is trying to apply -> or . to a function pointer 3008 // type, it's probably because they forgot parentheses to call that 3009 // function. Suggest the addition of those parentheses, build the 3010 // call, and continue on. 3011 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 3012 if (const FunctionProtoType *Fun 3013 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 3014 QualType ResultTy = Fun->getResultType(); 3015 if (Fun->getNumArgs() == 0 && 3016 ((!IsArrow && ResultTy->isRecordType()) || 3017 (IsArrow && ResultTy->isPointerType() && 3018 ResultTy->getAs<PointerType>()->getPointeeType() 3019 ->isRecordType()))) { 3020 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 3021 Diag(Loc, diag::err_member_reference_needs_call) 3022 << QualType(Fun, 0) 3023 << FixItHint::CreateInsertion(Loc, "()"); 3024 3025 ExprResult NewBase 3026 = ActOnCallExpr(0, BaseExpr, Loc, 3027 MultiExprArg(*this, 0, 0), 0, Loc); 3028 BaseExpr = 0; 3029 if (NewBase.isInvalid()) 3030 return ExprError(); 3031 3032 BaseExpr = NewBase.takeAs<Expr>(); 3033 DefaultFunctionArrayConversion(BaseExpr); 3034 BaseType = BaseExpr->getType(); 3035 } 3036 } 3037 } 3038 3039 // If this is an Objective-C pseudo-builtin and a definition is provided then 3040 // use that. 3041 if (BaseType->isObjCIdType()) { 3042 if (IsArrow) { 3043 // Handle the following exceptional case PObj->isa. 3044 if (const ObjCObjectPointerType *OPT = 3045 BaseType->getAs<ObjCObjectPointerType>()) { 3046 if (OPT->getObjectType()->isObjCId() && 3047 MemberName.getAsIdentifierInfo()->isStr("isa")) 3048 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 3049 Context.getObjCClassType())); 3050 } 3051 } 3052 // We have an 'id' type. Rather than fall through, we check if this 3053 // is a reference to 'isa'. 3054 if (BaseType != Context.ObjCIdRedefinitionType) { 3055 BaseType = Context.ObjCIdRedefinitionType; 3056 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3057 } 3058 } 3059 3060 // If this is an Objective-C pseudo-builtin and a definition is provided then 3061 // use that. 3062 if (Context.isObjCSelType(BaseType)) { 3063 // We have an 'SEL' type. Rather than fall through, we check if this 3064 // is a reference to 'sel_id'. 3065 if (BaseType != Context.ObjCSelRedefinitionType) { 3066 BaseType = Context.ObjCSelRedefinitionType; 3067 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3068 } 3069 } 3070 3071 assert(!BaseType.isNull() && "no type for member expression"); 3072 3073 // Handle properties on ObjC 'Class' types. 3074 if (!IsArrow && BaseType->isObjCClassType()) { 3075 // Also must look for a getter name which uses property syntax. 3076 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3077 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3078 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 3079 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3080 ObjCMethodDecl *Getter; 3081 // FIXME: need to also look locally in the implementation. 3082 if ((Getter = IFace->lookupClassMethod(Sel))) { 3083 // Check the use of this method. 3084 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3085 return ExprError(); 3086 } 3087 // If we found a getter then this may be a valid dot-reference, we 3088 // will look for the matching setter, in case it is needed. 3089 Selector SetterSel = 3090 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3091 PP.getSelectorTable(), Member); 3092 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3093 if (!Setter) { 3094 // If this reference is in an @implementation, also check for 'private' 3095 // methods. 3096 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3097 } 3098 // Look through local category implementations associated with the class. 3099 if (!Setter) 3100 Setter = IFace->getCategoryClassMethod(SetterSel); 3101 3102 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3103 return ExprError(); 3104 3105 if (Getter || Setter) { 3106 QualType PType; 3107 3108 if (Getter) 3109 PType = Getter->getSendResultType(); 3110 else 3111 // Get the expression type from Setter's incoming parameter. 3112 PType = (*(Setter->param_end() -1))->getType(); 3113 // FIXME: we must check that the setter has property type. 3114 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 3115 PType, 3116 Setter, MemberLoc, BaseExpr)); 3117 } 3118 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3119 << MemberName << BaseType); 3120 } 3121 } 3122 3123 if (BaseType->isObjCClassType() && 3124 BaseType != Context.ObjCClassRedefinitionType) { 3125 BaseType = Context.ObjCClassRedefinitionType; 3126 ImpCastExprToType(BaseExpr, BaseType, CK_BitCast); 3127 } 3128 3129 if (IsArrow) { 3130 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3131 BaseType = PT->getPointeeType(); 3132 else if (BaseType->isObjCObjectPointerType()) 3133 ; 3134 else if (BaseType->isRecordType()) { 3135 // Recover from arrow accesses to records, e.g.: 3136 // struct MyRecord foo; 3137 // foo->bar 3138 // This is actually well-formed in C++ if MyRecord has an 3139 // overloaded operator->, but that should have been dealt with 3140 // by now. 3141 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3142 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3143 << FixItHint::CreateReplacement(OpLoc, "."); 3144 IsArrow = false; 3145 } else { 3146 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3147 << BaseType << BaseExpr->getSourceRange(); 3148 return ExprError(); 3149 } 3150 } else { 3151 // Recover from dot accesses to pointers, e.g.: 3152 // type *foo; 3153 // foo.bar 3154 // This is actually well-formed in two cases: 3155 // - 'type' is an Objective C type 3156 // - 'bar' is a pseudo-destructor name which happens to refer to 3157 // the appropriate pointer type 3158 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3159 const PointerType *PT = BaseType->getAs<PointerType>(); 3160 if (PT && PT->getPointeeType()->isRecordType()) { 3161 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3162 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3163 << FixItHint::CreateReplacement(OpLoc, "->"); 3164 BaseType = PT->getPointeeType(); 3165 IsArrow = true; 3166 } 3167 } 3168 } 3169 3170 // Handle field access to simple records. 3171 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3172 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3173 RTy, OpLoc, SS, HasTemplateArgs)) 3174 return ExprError(); 3175 return Owned((Expr*) 0); 3176 } 3177 3178 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3179 // (*Obj).ivar. 3180 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3181 (!IsArrow && BaseType->isObjCObjectType())) { 3182 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3183 ObjCInterfaceDecl *IDecl = 3184 OPT ? OPT->getInterfaceDecl() 3185 : BaseType->getAs<ObjCObjectType>()->getInterface(); 3186 if (IDecl) { 3187 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3188 3189 ObjCInterfaceDecl *ClassDeclared; 3190 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3191 3192 if (!IV) { 3193 // Attempt to correct for typos in ivar names. 3194 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3195 LookupMemberName); 3196 if (CorrectTypo(Res, 0, 0, IDecl, false, CTC_MemberLookup) && 3197 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3198 Diag(R.getNameLoc(), 3199 diag::err_typecheck_member_reference_ivar_suggest) 3200 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3201 << FixItHint::CreateReplacement(R.getNameLoc(), 3202 IV->getNameAsString()); 3203 Diag(IV->getLocation(), diag::note_previous_decl) 3204 << IV->getDeclName(); 3205 } else { 3206 Res.clear(); 3207 Res.setLookupName(Member); 3208 } 3209 } 3210 3211 if (IV) { 3212 // If the decl being referenced had an error, return an error for this 3213 // sub-expr without emitting another error, in order to avoid cascading 3214 // error cases. 3215 if (IV->isInvalidDecl()) 3216 return ExprError(); 3217 3218 // Check whether we can reference this field. 3219 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3220 return ExprError(); 3221 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3222 IV->getAccessControl() != ObjCIvarDecl::Package) { 3223 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3224 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3225 ClassOfMethodDecl = MD->getClassInterface(); 3226 else if (ObjCImpDecl && getCurFunctionDecl()) { 3227 // Case of a c-function declared inside an objc implementation. 3228 // FIXME: For a c-style function nested inside an objc implementation 3229 // class, there is no implementation context available, so we pass 3230 // down the context as argument to this routine. Ideally, this context 3231 // need be passed down in the AST node and somehow calculated from the 3232 // AST for a function decl. 3233 if (ObjCImplementationDecl *IMPD = 3234 dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) 3235 ClassOfMethodDecl = IMPD->getClassInterface(); 3236 else if (ObjCCategoryImplDecl* CatImplClass = 3237 dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) 3238 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3239 } 3240 3241 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3242 if (ClassDeclared != IDecl || 3243 ClassOfMethodDecl != ClassDeclared) 3244 Diag(MemberLoc, diag::error_private_ivar_access) 3245 << IV->getDeclName(); 3246 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3247 // @protected 3248 Diag(MemberLoc, diag::error_protected_ivar_access) 3249 << IV->getDeclName(); 3250 } 3251 3252 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3253 MemberLoc, BaseExpr, 3254 IsArrow)); 3255 } 3256 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3257 << IDecl->getDeclName() << MemberName 3258 << BaseExpr->getSourceRange()); 3259 } 3260 } 3261 // Handle properties on 'id' and qualified "id". 3262 if (!IsArrow && (BaseType->isObjCIdType() || 3263 BaseType->isObjCQualifiedIdType())) { 3264 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3265 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3266 3267 // Check protocols on qualified interfaces. 3268 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3269 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3270 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3271 // Check the use of this declaration 3272 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3273 return ExprError(); 3274 3275 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3276 MemberLoc, BaseExpr)); 3277 } 3278 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3279 // Check the use of this method. 3280 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3281 return ExprError(); 3282 3283 return Owned(ObjCMessageExpr::Create(Context, 3284 OMD->getSendResultType(), 3285 OpLoc, BaseExpr, Sel, 3286 OMD, NULL, 0, MemberLoc)); 3287 } 3288 } 3289 3290 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3291 << MemberName << BaseType); 3292 } 3293 3294 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3295 // pointer to a (potentially qualified) interface type. 3296 if (!IsArrow) 3297 if (const ObjCObjectPointerType *OPT = 3298 BaseType->getAsObjCInterfacePointerType()) 3299 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc); 3300 3301 // Handle the following exceptional case (*Obj).isa. 3302 if (!IsArrow && 3303 BaseType->isObjCObjectType() && 3304 BaseType->getAs<ObjCObjectType>()->isObjCId() && 3305 MemberName.getAsIdentifierInfo()->isStr("isa")) 3306 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3307 Context.getObjCClassType())); 3308 3309 // Handle 'field access' to vectors, such as 'V.xx'. 3310 if (BaseType->isExtVectorType()) { 3311 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3312 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3313 if (ret.isNull()) 3314 return ExprError(); 3315 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3316 MemberLoc)); 3317 } 3318 3319 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3320 << BaseType << BaseExpr->getSourceRange(); 3321 3322 return ExprError(); 3323} 3324 3325/// The main callback when the parser finds something like 3326/// expression . [nested-name-specifier] identifier 3327/// expression -> [nested-name-specifier] identifier 3328/// where 'identifier' encompasses a fairly broad spectrum of 3329/// possibilities, including destructor and operator references. 3330/// 3331/// \param OpKind either tok::arrow or tok::period 3332/// \param HasTrailingLParen whether the next token is '(', which 3333/// is used to diagnose mis-uses of special members that can 3334/// only be called 3335/// \param ObjCImpDecl the current ObjC @implementation decl; 3336/// this is an ugly hack around the fact that ObjC @implementations 3337/// aren't properly put in the context chain 3338ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, 3339 SourceLocation OpLoc, 3340 tok::TokenKind OpKind, 3341 CXXScopeSpec &SS, 3342 UnqualifiedId &Id, 3343 Decl *ObjCImpDecl, 3344 bool HasTrailingLParen) { 3345 if (SS.isSet() && SS.isInvalid()) 3346 return ExprError(); 3347 3348 TemplateArgumentListInfo TemplateArgsBuffer; 3349 3350 // Decompose the name into its component parts. 3351 DeclarationNameInfo NameInfo; 3352 const TemplateArgumentListInfo *TemplateArgs; 3353 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3354 NameInfo, TemplateArgs); 3355 3356 DeclarationName Name = NameInfo.getName(); 3357 bool IsArrow = (OpKind == tok::arrow); 3358 3359 NamedDecl *FirstQualifierInScope 3360 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3361 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3362 3363 // This is a postfix expression, so get rid of ParenListExprs. 3364 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 3365 if (Result.isInvalid()) return ExprError(); 3366 Base = Result.take(); 3367 3368 if (Base->getType()->isDependentType() || Name.isDependentName() || 3369 isDependentScopeSpecifier(SS)) { 3370 Result = ActOnDependentMemberExpr(Base, Base->getType(), 3371 IsArrow, OpLoc, 3372 SS, FirstQualifierInScope, 3373 NameInfo, TemplateArgs); 3374 } else { 3375 LookupResult R(*this, NameInfo, LookupMemberName); 3376 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3377 SS, ObjCImpDecl, TemplateArgs != 0); 3378 3379 if (Result.isInvalid()) { 3380 Owned(Base); 3381 return ExprError(); 3382 } 3383 3384 if (Result.get()) { 3385 // The only way a reference to a destructor can be used is to 3386 // immediately call it, which falls into this case. If the 3387 // next token is not a '(', produce a diagnostic and build the 3388 // call now. 3389 if (!HasTrailingLParen && 3390 Id.getKind() == UnqualifiedId::IK_DestructorName) 3391 return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); 3392 3393 return move(Result); 3394 } 3395 3396 Result = BuildMemberReferenceExpr(Base, Base->getType(), 3397 OpLoc, IsArrow, SS, FirstQualifierInScope, 3398 R, TemplateArgs); 3399 } 3400 3401 return move(Result); 3402} 3403 3404ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3405 FunctionDecl *FD, 3406 ParmVarDecl *Param) { 3407 if (Param->hasUnparsedDefaultArg()) { 3408 Diag (CallLoc, 3409 diag::err_use_of_default_argument_to_function_declared_later) << 3410 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3411 Diag(UnparsedDefaultArgLocs[Param], 3412 diag::note_default_argument_declared_here); 3413 } else { 3414 if (Param->hasUninstantiatedDefaultArg()) { 3415 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3416 3417 // Instantiate the expression. 3418 MultiLevelTemplateArgumentList ArgList 3419 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3420 3421 std::pair<const TemplateArgument *, unsigned> Innermost 3422 = ArgList.getInnermost(); 3423 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3424 Innermost.second); 3425 3426 ExprResult Result = SubstExpr(UninstExpr, ArgList); 3427 if (Result.isInvalid()) 3428 return ExprError(); 3429 3430 // Check the expression as an initializer for the parameter. 3431 InitializedEntity Entity 3432 = InitializedEntity::InitializeParameter(Param); 3433 InitializationKind Kind 3434 = InitializationKind::CreateCopy(Param->getLocation(), 3435 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3436 Expr *ResultE = Result.takeAs<Expr>(); 3437 3438 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3439 Result = InitSeq.Perform(*this, Entity, Kind, 3440 MultiExprArg(*this, &ResultE, 1)); 3441 if (Result.isInvalid()) 3442 return ExprError(); 3443 3444 // Build the default argument expression. 3445 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3446 Result.takeAs<Expr>())); 3447 } 3448 3449 // If the default expression creates temporaries, we need to 3450 // push them to the current stack of expression temporaries so they'll 3451 // be properly destroyed. 3452 // FIXME: We should really be rebuilding the default argument with new 3453 // bound temporaries; see the comment in PR5810. 3454 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3455 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3456 } 3457 3458 // We already type-checked the argument, so we know it works. 3459 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3460} 3461 3462/// ConvertArgumentsForCall - Converts the arguments specified in 3463/// Args/NumArgs to the parameter types of the function FDecl with 3464/// function prototype Proto. Call is the call expression itself, and 3465/// Fn is the function expression. For a C++ member function, this 3466/// routine does not attempt to convert the object argument. Returns 3467/// true if the call is ill-formed. 3468bool 3469Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3470 FunctionDecl *FDecl, 3471 const FunctionProtoType *Proto, 3472 Expr **Args, unsigned NumArgs, 3473 SourceLocation RParenLoc) { 3474 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3475 // assignment, to the types of the corresponding parameter, ... 3476 unsigned NumArgsInProto = Proto->getNumArgs(); 3477 bool Invalid = false; 3478 3479 // If too few arguments are available (and we don't have default 3480 // arguments for the remaining parameters), don't make the call. 3481 if (NumArgs < NumArgsInProto) { 3482 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3483 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3484 << Fn->getType()->isBlockPointerType() 3485 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 3486 Call->setNumArgs(Context, NumArgsInProto); 3487 } 3488 3489 // If too many are passed and not variadic, error on the extras and drop 3490 // them. 3491 if (NumArgs > NumArgsInProto) { 3492 if (!Proto->isVariadic()) { 3493 Diag(Args[NumArgsInProto]->getLocStart(), 3494 diag::err_typecheck_call_too_many_args) 3495 << Fn->getType()->isBlockPointerType() 3496 << NumArgsInProto << NumArgs << Fn->getSourceRange() 3497 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3498 Args[NumArgs-1]->getLocEnd()); 3499 // This deletes the extra arguments. 3500 Call->setNumArgs(Context, NumArgsInProto); 3501 return true; 3502 } 3503 } 3504 llvm::SmallVector<Expr *, 8> AllArgs; 3505 VariadicCallType CallType = 3506 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3507 if (Fn->getType()->isBlockPointerType()) 3508 CallType = VariadicBlock; // Block 3509 else if (isa<MemberExpr>(Fn)) 3510 CallType = VariadicMethod; 3511 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3512 Proto, 0, Args, NumArgs, AllArgs, CallType); 3513 if (Invalid) 3514 return true; 3515 unsigned TotalNumArgs = AllArgs.size(); 3516 for (unsigned i = 0; i < TotalNumArgs; ++i) 3517 Call->setArg(i, AllArgs[i]); 3518 3519 return false; 3520} 3521 3522bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3523 FunctionDecl *FDecl, 3524 const FunctionProtoType *Proto, 3525 unsigned FirstProtoArg, 3526 Expr **Args, unsigned NumArgs, 3527 llvm::SmallVector<Expr *, 8> &AllArgs, 3528 VariadicCallType CallType) { 3529 unsigned NumArgsInProto = Proto->getNumArgs(); 3530 unsigned NumArgsToCheck = NumArgs; 3531 bool Invalid = false; 3532 if (NumArgs != NumArgsInProto) 3533 // Use default arguments for missing arguments 3534 NumArgsToCheck = NumArgsInProto; 3535 unsigned ArgIx = 0; 3536 // Continue to check argument types (even if we have too few/many args). 3537 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3538 QualType ProtoArgType = Proto->getArgType(i); 3539 3540 Expr *Arg; 3541 if (ArgIx < NumArgs) { 3542 Arg = Args[ArgIx++]; 3543 3544 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3545 ProtoArgType, 3546 PDiag(diag::err_call_incomplete_argument) 3547 << Arg->getSourceRange())) 3548 return true; 3549 3550 // Pass the argument 3551 ParmVarDecl *Param = 0; 3552 if (FDecl && i < FDecl->getNumParams()) 3553 Param = FDecl->getParamDecl(i); 3554 3555 3556 InitializedEntity Entity = 3557 Param? InitializedEntity::InitializeParameter(Param) 3558 : InitializedEntity::InitializeParameter(ProtoArgType); 3559 ExprResult ArgE = PerformCopyInitialization(Entity, 3560 SourceLocation(), 3561 Owned(Arg)); 3562 if (ArgE.isInvalid()) 3563 return true; 3564 3565 Arg = ArgE.takeAs<Expr>(); 3566 } else { 3567 ParmVarDecl *Param = FDecl->getParamDecl(i); 3568 3569 ExprResult ArgExpr = 3570 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3571 if (ArgExpr.isInvalid()) 3572 return true; 3573 3574 Arg = ArgExpr.takeAs<Expr>(); 3575 } 3576 AllArgs.push_back(Arg); 3577 } 3578 3579 // If this is a variadic call, handle args passed through "...". 3580 if (CallType != VariadicDoesNotApply) { 3581 // Promote the arguments (C99 6.5.2.2p7). 3582 for (unsigned i = ArgIx; i != NumArgs; ++i) { 3583 Expr *Arg = Args[i]; 3584 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 3585 AllArgs.push_back(Arg); 3586 } 3587 } 3588 return Invalid; 3589} 3590 3591/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3592/// This provides the location of the left/right parens and a list of comma 3593/// locations. 3594ExprResult 3595Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, 3596 MultiExprArg args, 3597 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3598 unsigned NumArgs = args.size(); 3599 3600 // Since this might be a postfix expression, get rid of ParenListExprs. 3601 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); 3602 if (Result.isInvalid()) return ExprError(); 3603 Fn = Result.take(); 3604 3605 Expr **Args = args.release(); 3606 3607 if (getLangOptions().CPlusPlus) { 3608 // If this is a pseudo-destructor expression, build the call immediately. 3609 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3610 if (NumArgs > 0) { 3611 // Pseudo-destructor calls should not have any arguments. 3612 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3613 << FixItHint::CreateRemoval( 3614 SourceRange(Args[0]->getLocStart(), 3615 Args[NumArgs-1]->getLocEnd())); 3616 3617 NumArgs = 0; 3618 } 3619 3620 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3621 RParenLoc)); 3622 } 3623 3624 // Determine whether this is a dependent call inside a C++ template, 3625 // in which case we won't do any semantic analysis now. 3626 // FIXME: Will need to cache the results of name lookup (including ADL) in 3627 // Fn. 3628 bool Dependent = false; 3629 if (Fn->isTypeDependent()) 3630 Dependent = true; 3631 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3632 Dependent = true; 3633 3634 if (Dependent) 3635 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3636 Context.DependentTy, RParenLoc)); 3637 3638 // Determine whether this is a call to an object (C++ [over.call.object]). 3639 if (Fn->getType()->isRecordType()) 3640 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3641 CommaLocs, RParenLoc)); 3642 3643 Expr *NakedFn = Fn->IgnoreParens(); 3644 3645 // Determine whether this is a call to an unresolved member function. 3646 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3647 // If lookup was unresolved but not dependent (i.e. didn't find 3648 // an unresolved using declaration), it has to be an overloaded 3649 // function set, which means it must contain either multiple 3650 // declarations (all methods or method templates) or a single 3651 // method template. 3652 assert((MemE->getNumDecls() > 1) || 3653 isa<FunctionTemplateDecl>( 3654 (*MemE->decls_begin())->getUnderlyingDecl())); 3655 (void)MemE; 3656 3657 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3658 CommaLocs, RParenLoc); 3659 } 3660 3661 // Determine whether this is a call to a member function. 3662 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3663 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3664 if (isa<CXXMethodDecl>(MemDecl)) 3665 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3666 CommaLocs, RParenLoc); 3667 } 3668 3669 // Determine whether this is a call to a pointer-to-member function. 3670 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3671 if (BO->getOpcode() == BO_PtrMemD || 3672 BO->getOpcode() == BO_PtrMemI) { 3673 if (const FunctionProtoType *FPT 3674 = BO->getType()->getAs<FunctionProtoType>()) { 3675 QualType ResultTy = FPT->getCallResultType(Context); 3676 3677 CXXMemberCallExpr *TheCall 3678 = new (Context) CXXMemberCallExpr(Context, BO, Args, 3679 NumArgs, ResultTy, 3680 RParenLoc); 3681 3682 if (CheckCallReturnType(FPT->getResultType(), 3683 BO->getRHS()->getSourceRange().getBegin(), 3684 TheCall, 0)) 3685 return ExprError(); 3686 3687 if (ConvertArgumentsForCall(TheCall, BO, 0, FPT, Args, NumArgs, 3688 RParenLoc)) 3689 return ExprError(); 3690 3691 return MaybeBindToTemporary(TheCall); 3692 } 3693 return ExprError(Diag(Fn->getLocStart(), 3694 diag::err_typecheck_call_not_function) 3695 << Fn->getType() << Fn->getSourceRange()); 3696 } 3697 } 3698 } 3699 3700 // If we're directly calling a function, get the appropriate declaration. 3701 // Also, in C++, keep track of whether we should perform argument-dependent 3702 // lookup and whether there were any explicitly-specified template arguments. 3703 3704 Expr *NakedFn = Fn->IgnoreParens(); 3705 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3706 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3707 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 3708 CommaLocs, RParenLoc); 3709 } 3710 3711 NamedDecl *NDecl = 0; 3712 if (isa<DeclRefExpr>(NakedFn)) 3713 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3714 3715 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3716} 3717 3718/// BuildResolvedCallExpr - Build a call to a resolved expression, 3719/// i.e. an expression not of \p OverloadTy. The expression should 3720/// unary-convert to an expression of function-pointer or 3721/// block-pointer type. 3722/// 3723/// \param NDecl the declaration being called, if available 3724ExprResult 3725Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3726 SourceLocation LParenLoc, 3727 Expr **Args, unsigned NumArgs, 3728 SourceLocation RParenLoc) { 3729 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3730 3731 // Promote the function operand. 3732 UsualUnaryConversions(Fn); 3733 3734 // Make the call expr early, before semantic checks. This guarantees cleanup 3735 // of arguments and function on error. 3736 CallExpr *TheCall = new (Context) CallExpr(Context, Fn, 3737 Args, NumArgs, 3738 Context.BoolTy, 3739 RParenLoc); 3740 3741 const FunctionType *FuncT; 3742 if (!Fn->getType()->isBlockPointerType()) { 3743 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3744 // have type pointer to function". 3745 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3746 if (PT == 0) 3747 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3748 << Fn->getType() << Fn->getSourceRange()); 3749 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3750 } else { // This is a block call. 3751 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3752 getAs<FunctionType>(); 3753 } 3754 if (FuncT == 0) 3755 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3756 << Fn->getType() << Fn->getSourceRange()); 3757 3758 // Check for a valid return type 3759 if (CheckCallReturnType(FuncT->getResultType(), 3760 Fn->getSourceRange().getBegin(), TheCall, 3761 FDecl)) 3762 return ExprError(); 3763 3764 // We know the result type of the call, set it. 3765 TheCall->setType(FuncT->getCallResultType(Context)); 3766 3767 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3768 if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, NumArgs, 3769 RParenLoc)) 3770 return ExprError(); 3771 } else { 3772 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3773 3774 if (FDecl) { 3775 // Check if we have too few/too many template arguments, based 3776 // on our knowledge of the function definition. 3777 const FunctionDecl *Def = 0; 3778 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 3779 const FunctionProtoType *Proto = 3780 Def->getType()->getAs<FunctionProtoType>(); 3781 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3782 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3783 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3784 } 3785 } 3786 } 3787 3788 // Promote the arguments (C99 6.5.2.2p6). 3789 for (unsigned i = 0; i != NumArgs; i++) { 3790 Expr *Arg = Args[i]; 3791 DefaultArgumentPromotion(Arg); 3792 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3793 Arg->getType(), 3794 PDiag(diag::err_call_incomplete_argument) 3795 << Arg->getSourceRange())) 3796 return ExprError(); 3797 TheCall->setArg(i, Arg); 3798 } 3799 } 3800 3801 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3802 if (!Method->isStatic()) 3803 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3804 << Fn->getSourceRange()); 3805 3806 // Check for sentinels 3807 if (NDecl) 3808 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3809 3810 // Do special checking on direct calls to functions. 3811 if (FDecl) { 3812 if (CheckFunctionCall(FDecl, TheCall)) 3813 return ExprError(); 3814 3815 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3816 return CheckBuiltinFunctionCall(BuiltinID, TheCall); 3817 } else if (NDecl) { 3818 if (CheckBlockCall(NDecl, TheCall)) 3819 return ExprError(); 3820 } 3821 3822 return MaybeBindToTemporary(TheCall); 3823} 3824 3825ExprResult 3826Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, 3827 SourceLocation RParenLoc, Expr *InitExpr) { 3828 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3829 // FIXME: put back this assert when initializers are worked out. 3830 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3831 3832 TypeSourceInfo *TInfo; 3833 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3834 if (!TInfo) 3835 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3836 3837 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); 3838} 3839 3840ExprResult 3841Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3842 SourceLocation RParenLoc, Expr *literalExpr) { 3843 QualType literalType = TInfo->getType(); 3844 3845 if (literalType->isArrayType()) { 3846 if (literalType->isVariableArrayType()) 3847 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3848 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3849 } else if (!literalType->isDependentType() && 3850 RequireCompleteType(LParenLoc, literalType, 3851 PDiag(diag::err_typecheck_decl_incomplete_type) 3852 << SourceRange(LParenLoc, 3853 literalExpr->getSourceRange().getEnd()))) 3854 return ExprError(); 3855 3856 InitializedEntity Entity 3857 = InitializedEntity::InitializeTemporary(literalType); 3858 InitializationKind Kind 3859 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3860 /*IsCStyleCast=*/true); 3861 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3862 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3863 MultiExprArg(*this, &literalExpr, 1), 3864 &literalType); 3865 if (Result.isInvalid()) 3866 return ExprError(); 3867 literalExpr = Result.get(); 3868 3869 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3870 if (isFileScope) { // 6.5.2.5p3 3871 if (CheckForConstantInitializer(literalExpr, literalType)) 3872 return ExprError(); 3873 } 3874 3875 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3876 literalExpr, isFileScope)); 3877} 3878 3879ExprResult 3880Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3881 SourceLocation RBraceLoc) { 3882 unsigned NumInit = initlist.size(); 3883 Expr **InitList = initlist.release(); 3884 3885 // Semantic analysis for initializers is done by ActOnDeclarator() and 3886 // CheckInitializer() - it requires knowledge of the object being intialized. 3887 3888 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 3889 NumInit, RBraceLoc); 3890 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3891 return Owned(E); 3892} 3893 3894static CastKind getScalarCastKind(ASTContext &Context, 3895 QualType SrcTy, QualType DestTy) { 3896 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3897 return CK_NoOp; 3898 3899 if (SrcTy->hasPointerRepresentation()) { 3900 if (DestTy->hasPointerRepresentation()) 3901 return DestTy->isObjCObjectPointerType() ? 3902 CK_AnyPointerToObjCPointerCast : 3903 CK_BitCast; 3904 if (DestTy->isIntegerType()) 3905 return CK_PointerToIntegral; 3906 } 3907 3908 if (SrcTy->isIntegerType()) { 3909 if (DestTy->isIntegerType()) 3910 return CK_IntegralCast; 3911 if (DestTy->hasPointerRepresentation()) 3912 return CK_IntegralToPointer; 3913 if (DestTy->isRealFloatingType()) 3914 return CK_IntegralToFloating; 3915 } 3916 3917 if (SrcTy->isRealFloatingType()) { 3918 if (DestTy->isRealFloatingType()) 3919 return CK_FloatingCast; 3920 if (DestTy->isIntegerType()) 3921 return CK_FloatingToIntegral; 3922 } 3923 3924 // FIXME: Assert here. 3925 // assert(false && "Unhandled cast combination!"); 3926 return CK_Unknown; 3927} 3928 3929/// CheckCastTypes - Check type constraints for casting between types. 3930bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3931 CastKind& Kind, 3932 CXXCastPath &BasePath, 3933 bool FunctionalStyle) { 3934 if (getLangOptions().CPlusPlus) 3935 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, BasePath, 3936 FunctionalStyle); 3937 3938 DefaultFunctionArrayLvalueConversion(castExpr); 3939 3940 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3941 // type needs to be scalar. 3942 if (castType->isVoidType()) { 3943 // Cast to void allows any expr type. 3944 Kind = CK_ToVoid; 3945 return false; 3946 } 3947 3948 if (RequireCompleteType(TyR.getBegin(), castType, 3949 diag::err_typecheck_cast_to_incomplete)) 3950 return true; 3951 3952 if (!castType->isScalarType() && !castType->isVectorType()) { 3953 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3954 (castType->isStructureType() || castType->isUnionType())) { 3955 // GCC struct/union extension: allow cast to self. 3956 // FIXME: Check that the cast destination type is complete. 3957 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3958 << castType << castExpr->getSourceRange(); 3959 Kind = CK_NoOp; 3960 return false; 3961 } 3962 3963 if (castType->isUnionType()) { 3964 // GCC cast to union extension 3965 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3966 RecordDecl::field_iterator Field, FieldEnd; 3967 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3968 Field != FieldEnd; ++Field) { 3969 if (Context.hasSameUnqualifiedType(Field->getType(), 3970 castExpr->getType())) { 3971 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3972 << castExpr->getSourceRange(); 3973 break; 3974 } 3975 } 3976 if (Field == FieldEnd) 3977 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3978 << castExpr->getType() << castExpr->getSourceRange(); 3979 Kind = CK_ToUnion; 3980 return false; 3981 } 3982 3983 // Reject any other conversions to non-scalar types. 3984 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3985 << castType << castExpr->getSourceRange(); 3986 } 3987 3988 if (!castExpr->getType()->isScalarType() && 3989 !castExpr->getType()->isVectorType()) { 3990 return Diag(castExpr->getLocStart(), 3991 diag::err_typecheck_expect_scalar_operand) 3992 << castExpr->getType() << castExpr->getSourceRange(); 3993 } 3994 3995 if (castType->isExtVectorType()) 3996 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3997 3998 if (castType->isVectorType()) 3999 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 4000 if (castExpr->getType()->isVectorType()) 4001 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 4002 4003 if (isa<ObjCSelectorExpr>(castExpr)) 4004 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 4005 4006 if (!castType->isArithmeticType()) { 4007 QualType castExprType = castExpr->getType(); 4008 if (!castExprType->isIntegralType(Context) && 4009 castExprType->isArithmeticType()) 4010 return Diag(castExpr->getLocStart(), 4011 diag::err_cast_pointer_from_non_pointer_int) 4012 << castExprType << castExpr->getSourceRange(); 4013 } else if (!castExpr->getType()->isArithmeticType()) { 4014 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 4015 return Diag(castExpr->getLocStart(), 4016 diag::err_cast_pointer_to_non_pointer_int) 4017 << castType << castExpr->getSourceRange(); 4018 } 4019 4020 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 4021 4022 if (Kind == CK_Unknown || Kind == CK_BitCast) 4023 CheckCastAlign(castExpr, castType, TyR); 4024 4025 return false; 4026} 4027 4028bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 4029 CastKind &Kind) { 4030 assert(VectorTy->isVectorType() && "Not a vector type!"); 4031 4032 if (Ty->isVectorType() || Ty->isIntegerType()) { 4033 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 4034 return Diag(R.getBegin(), 4035 Ty->isVectorType() ? 4036 diag::err_invalid_conversion_between_vectors : 4037 diag::err_invalid_conversion_between_vector_and_integer) 4038 << VectorTy << Ty << R; 4039 } else 4040 return Diag(R.getBegin(), 4041 diag::err_invalid_conversion_between_vector_and_scalar) 4042 << VectorTy << Ty << R; 4043 4044 Kind = CK_BitCast; 4045 return false; 4046} 4047 4048bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4049 CastKind &Kind) { 4050 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4051 4052 QualType SrcTy = CastExpr->getType(); 4053 4054 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4055 // an ExtVectorType. 4056 if (SrcTy->isVectorType()) { 4057 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4058 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4059 << DestTy << SrcTy << R; 4060 Kind = CK_BitCast; 4061 return false; 4062 } 4063 4064 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4065 // conversion will take place first from scalar to elt type, and then 4066 // splat from elt type to vector. 4067 if (SrcTy->isPointerType()) 4068 return Diag(R.getBegin(), 4069 diag::err_invalid_conversion_between_vector_and_scalar) 4070 << DestTy << SrcTy << R; 4071 4072 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4073 ImpCastExprToType(CastExpr, DestElemTy, 4074 getScalarCastKind(Context, SrcTy, DestElemTy)); 4075 4076 Kind = CK_VectorSplat; 4077 return false; 4078} 4079 4080ExprResult 4081Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, ParsedType Ty, 4082 SourceLocation RParenLoc, Expr *castExpr) { 4083 assert((Ty != 0) && (castExpr != 0) && 4084 "ActOnCastExpr(): missing type or expr"); 4085 4086 TypeSourceInfo *castTInfo; 4087 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4088 if (!castTInfo) 4089 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4090 4091 // If the Expr being casted is a ParenListExpr, handle it specially. 4092 if (isa<ParenListExpr>(castExpr)) 4093 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, castExpr, 4094 castTInfo); 4095 4096 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, castExpr); 4097} 4098 4099ExprResult 4100Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4101 SourceLocation RParenLoc, Expr *castExpr) { 4102 CastKind Kind = CK_Unknown; 4103 CXXCastPath BasePath; 4104 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4105 Kind, BasePath)) 4106 return ExprError(); 4107 4108 return Owned(CStyleCastExpr::Create(Context, 4109 Ty->getType().getNonLValueExprType(Context), 4110 Kind, castExpr, &BasePath, Ty, 4111 LParenLoc, RParenLoc)); 4112} 4113 4114/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4115/// of comma binary operators. 4116ExprResult 4117Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *expr) { 4118 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4119 if (!E) 4120 return Owned(expr); 4121 4122 ExprResult Result(E->getExpr(0)); 4123 4124 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4125 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), 4126 E->getExpr(i)); 4127 4128 if (Result.isInvalid()) return ExprError(); 4129 4130 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); 4131} 4132 4133ExprResult 4134Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4135 SourceLocation RParenLoc, Expr *Op, 4136 TypeSourceInfo *TInfo) { 4137 ParenListExpr *PE = cast<ParenListExpr>(Op); 4138 QualType Ty = TInfo->getType(); 4139 bool isAltiVecLiteral = false; 4140 4141 // Check for an altivec literal, 4142 // i.e. all the elements are integer constants. 4143 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4144 if (PE->getNumExprs() == 0) { 4145 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4146 return ExprError(); 4147 } 4148 if (PE->getNumExprs() == 1) { 4149 if (!PE->getExpr(0)->getType()->isVectorType()) 4150 isAltiVecLiteral = true; 4151 } 4152 else 4153 isAltiVecLiteral = true; 4154 } 4155 4156 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4157 // then handle it as such. 4158 if (isAltiVecLiteral) { 4159 llvm::SmallVector<Expr *, 8> initExprs; 4160 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4161 initExprs.push_back(PE->getExpr(i)); 4162 4163 // FIXME: This means that pretty-printing the final AST will produce curly 4164 // braces instead of the original commas. 4165 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4166 &initExprs[0], 4167 initExprs.size(), RParenLoc); 4168 E->setType(Ty); 4169 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, E); 4170 } else { 4171 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4172 // sequence of BinOp comma operators. 4173 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Op); 4174 if (Result.isInvalid()) return ExprError(); 4175 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Result.take()); 4176 } 4177} 4178 4179ExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4180 SourceLocation R, 4181 MultiExprArg Val, 4182 ParsedType TypeOfCast) { 4183 unsigned nexprs = Val.size(); 4184 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4185 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4186 Expr *expr; 4187 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4188 expr = new (Context) ParenExpr(L, R, exprs[0]); 4189 else 4190 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4191 return Owned(expr); 4192} 4193 4194/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4195/// In that case, lhs = cond. 4196/// C99 6.5.15 4197QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4198 SourceLocation QuestionLoc) { 4199 // C++ is sufficiently different to merit its own checker. 4200 if (getLangOptions().CPlusPlus) 4201 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4202 4203 UsualUnaryConversions(Cond); 4204 UsualUnaryConversions(LHS); 4205 UsualUnaryConversions(RHS); 4206 QualType CondTy = Cond->getType(); 4207 QualType LHSTy = LHS->getType(); 4208 QualType RHSTy = RHS->getType(); 4209 4210 // first, check the condition. 4211 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4212 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4213 << CondTy; 4214 return QualType(); 4215 } 4216 4217 // Now check the two expressions. 4218 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4219 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4220 4221 // If both operands have arithmetic type, do the usual arithmetic conversions 4222 // to find a common type: C99 6.5.15p3,5. 4223 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4224 UsualArithmeticConversions(LHS, RHS); 4225 return LHS->getType(); 4226 } 4227 4228 // If both operands are the same structure or union type, the result is that 4229 // type. 4230 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4231 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4232 if (LHSRT->getDecl() == RHSRT->getDecl()) 4233 // "If both the operands have structure or union type, the result has 4234 // that type." This implies that CV qualifiers are dropped. 4235 return LHSTy.getUnqualifiedType(); 4236 // FIXME: Type of conditional expression must be complete in C mode. 4237 } 4238 4239 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4240 // The following || allows only one side to be void (a GCC-ism). 4241 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4242 if (!LHSTy->isVoidType()) 4243 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4244 << RHS->getSourceRange(); 4245 if (!RHSTy->isVoidType()) 4246 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4247 << LHS->getSourceRange(); 4248 ImpCastExprToType(LHS, Context.VoidTy, CK_ToVoid); 4249 ImpCastExprToType(RHS, Context.VoidTy, CK_ToVoid); 4250 return Context.VoidTy; 4251 } 4252 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4253 // the type of the other operand." 4254 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4255 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4256 // promote the null to a pointer. 4257 ImpCastExprToType(RHS, LHSTy, CK_Unknown); 4258 return LHSTy; 4259 } 4260 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4261 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4262 ImpCastExprToType(LHS, RHSTy, CK_Unknown); 4263 return RHSTy; 4264 } 4265 4266 // All objective-c pointer type analysis is done here. 4267 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4268 QuestionLoc); 4269 if (!compositeType.isNull()) 4270 return compositeType; 4271 4272 4273 // Handle block pointer types. 4274 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4275 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4276 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4277 QualType destType = Context.getPointerType(Context.VoidTy); 4278 ImpCastExprToType(LHS, destType, CK_BitCast); 4279 ImpCastExprToType(RHS, destType, CK_BitCast); 4280 return destType; 4281 } 4282 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4283 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4284 return QualType(); 4285 } 4286 // We have 2 block pointer types. 4287 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4288 // Two identical block pointer types are always compatible. 4289 return LHSTy; 4290 } 4291 // The block pointer types aren't identical, continue checking. 4292 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4293 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4294 4295 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4296 rhptee.getUnqualifiedType())) { 4297 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4298 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4299 // In this situation, we assume void* type. No especially good 4300 // reason, but this is what gcc does, and we do have to pick 4301 // to get a consistent AST. 4302 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4303 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4304 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4305 return incompatTy; 4306 } 4307 // The block pointer types are compatible. 4308 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 4309 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4310 return LHSTy; 4311 } 4312 4313 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4314 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4315 // get the "pointed to" types 4316 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4317 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4318 4319 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4320 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4321 // Figure out necessary qualifiers (C99 6.5.15p6) 4322 QualType destPointee 4323 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4324 QualType destType = Context.getPointerType(destPointee); 4325 // Add qualifiers if necessary. 4326 ImpCastExprToType(LHS, destType, CK_NoOp); 4327 // Promote to void*. 4328 ImpCastExprToType(RHS, destType, CK_BitCast); 4329 return destType; 4330 } 4331 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4332 QualType destPointee 4333 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4334 QualType destType = Context.getPointerType(destPointee); 4335 // Add qualifiers if necessary. 4336 ImpCastExprToType(RHS, destType, CK_NoOp); 4337 // Promote to void*. 4338 ImpCastExprToType(LHS, destType, CK_BitCast); 4339 return destType; 4340 } 4341 4342 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4343 // Two identical pointer types are always compatible. 4344 return LHSTy; 4345 } 4346 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4347 rhptee.getUnqualifiedType())) { 4348 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4349 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4350 // In this situation, we assume void* type. No especially good 4351 // reason, but this is what gcc does, and we do have to pick 4352 // to get a consistent AST. 4353 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4354 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4355 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4356 return incompatTy; 4357 } 4358 // The pointer types are compatible. 4359 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4360 // differently qualified versions of compatible types, the result type is 4361 // a pointer to an appropriately qualified version of the *composite* 4362 // type. 4363 // FIXME: Need to calculate the composite type. 4364 // FIXME: Need to add qualifiers 4365 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 4366 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4367 return LHSTy; 4368 } 4369 4370 // GCC compatibility: soften pointer/integer mismatch. 4371 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4372 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4373 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4374 ImpCastExprToType(LHS, RHSTy, CK_IntegralToPointer); 4375 return RHSTy; 4376 } 4377 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4378 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4379 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4380 ImpCastExprToType(RHS, LHSTy, CK_IntegralToPointer); 4381 return LHSTy; 4382 } 4383 4384 // Otherwise, the operands are not compatible. 4385 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4386 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4387 return QualType(); 4388} 4389 4390/// FindCompositeObjCPointerType - Helper method to find composite type of 4391/// two objective-c pointer types of the two input expressions. 4392QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4393 SourceLocation QuestionLoc) { 4394 QualType LHSTy = LHS->getType(); 4395 QualType RHSTy = RHS->getType(); 4396 4397 // Handle things like Class and struct objc_class*. Here we case the result 4398 // to the pseudo-builtin, because that will be implicitly cast back to the 4399 // redefinition type if an attempt is made to access its fields. 4400 if (LHSTy->isObjCClassType() && 4401 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4402 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4403 return LHSTy; 4404 } 4405 if (RHSTy->isObjCClassType() && 4406 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4407 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4408 return RHSTy; 4409 } 4410 // And the same for struct objc_object* / id 4411 if (LHSTy->isObjCIdType() && 4412 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4413 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4414 return LHSTy; 4415 } 4416 if (RHSTy->isObjCIdType() && 4417 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4418 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4419 return RHSTy; 4420 } 4421 // And the same for struct objc_selector* / SEL 4422 if (Context.isObjCSelType(LHSTy) && 4423 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4424 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 4425 return LHSTy; 4426 } 4427 if (Context.isObjCSelType(RHSTy) && 4428 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4429 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 4430 return RHSTy; 4431 } 4432 // Check constraints for Objective-C object pointers types. 4433 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4434 4435 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4436 // Two identical object pointer types are always compatible. 4437 return LHSTy; 4438 } 4439 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4440 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4441 QualType compositeType = LHSTy; 4442 4443 // If both operands are interfaces and either operand can be 4444 // assigned to the other, use that type as the composite 4445 // type. This allows 4446 // xxx ? (A*) a : (B*) b 4447 // where B is a subclass of A. 4448 // 4449 // Additionally, as for assignment, if either type is 'id' 4450 // allow silent coercion. Finally, if the types are 4451 // incompatible then make sure to use 'id' as the composite 4452 // type so the result is acceptable for sending messages to. 4453 4454 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4455 // It could return the composite type. 4456 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4457 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4458 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4459 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4460 } else if ((LHSTy->isObjCQualifiedIdType() || 4461 RHSTy->isObjCQualifiedIdType()) && 4462 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4463 // Need to handle "id<xx>" explicitly. 4464 // GCC allows qualified id and any Objective-C type to devolve to 4465 // id. Currently localizing to here until clear this should be 4466 // part of ObjCQualifiedIdTypesAreCompatible. 4467 compositeType = Context.getObjCIdType(); 4468 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4469 compositeType = Context.getObjCIdType(); 4470 } else if (!(compositeType = 4471 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4472 ; 4473 else { 4474 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4475 << LHSTy << RHSTy 4476 << LHS->getSourceRange() << RHS->getSourceRange(); 4477 QualType incompatTy = Context.getObjCIdType(); 4478 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 4479 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 4480 return incompatTy; 4481 } 4482 // The object pointer types are compatible. 4483 ImpCastExprToType(LHS, compositeType, CK_BitCast); 4484 ImpCastExprToType(RHS, compositeType, CK_BitCast); 4485 return compositeType; 4486 } 4487 // Check Objective-C object pointer types and 'void *' 4488 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4489 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4490 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4491 QualType destPointee 4492 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4493 QualType destType = Context.getPointerType(destPointee); 4494 // Add qualifiers if necessary. 4495 ImpCastExprToType(LHS, destType, CK_NoOp); 4496 // Promote to void*. 4497 ImpCastExprToType(RHS, destType, CK_BitCast); 4498 return destType; 4499 } 4500 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4501 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4502 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4503 QualType destPointee 4504 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4505 QualType destType = Context.getPointerType(destPointee); 4506 // Add qualifiers if necessary. 4507 ImpCastExprToType(RHS, destType, CK_NoOp); 4508 // Promote to void*. 4509 ImpCastExprToType(LHS, destType, CK_BitCast); 4510 return destType; 4511 } 4512 return QualType(); 4513} 4514 4515/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4516/// in the case of a the GNU conditional expr extension. 4517ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4518 SourceLocation ColonLoc, 4519 Expr *CondExpr, Expr *LHSExpr, 4520 Expr *RHSExpr) { 4521 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4522 // was the condition. 4523 bool isLHSNull = LHSExpr == 0; 4524 Expr *SAVEExpr = 0; 4525 if (isLHSNull) { 4526 LHSExpr = SAVEExpr = CondExpr; 4527 } 4528 4529 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4530 RHSExpr, QuestionLoc); 4531 if (result.isNull()) 4532 return ExprError(); 4533 4534 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4535 LHSExpr, ColonLoc, 4536 RHSExpr, SAVEExpr, 4537 result)); 4538} 4539 4540// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4541// being closely modeled after the C99 spec:-). The odd characteristic of this 4542// routine is it effectively iqnores the qualifiers on the top level pointee. 4543// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4544// FIXME: add a couple examples in this comment. 4545Sema::AssignConvertType 4546Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4547 QualType lhptee, rhptee; 4548 4549 if ((lhsType->isObjCClassType() && 4550 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4551 (rhsType->isObjCClassType() && 4552 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4553 return Compatible; 4554 } 4555 4556 // get the "pointed to" type (ignoring qualifiers at the top level) 4557 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4558 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4559 4560 // make sure we operate on the canonical type 4561 lhptee = Context.getCanonicalType(lhptee); 4562 rhptee = Context.getCanonicalType(rhptee); 4563 4564 AssignConvertType ConvTy = Compatible; 4565 4566 // C99 6.5.16.1p1: This following citation is common to constraints 4567 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4568 // qualifiers of the type *pointed to* by the right; 4569 // FIXME: Handle ExtQualType 4570 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4571 ConvTy = CompatiblePointerDiscardsQualifiers; 4572 4573 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4574 // incomplete type and the other is a pointer to a qualified or unqualified 4575 // version of void... 4576 if (lhptee->isVoidType()) { 4577 if (rhptee->isIncompleteOrObjectType()) 4578 return ConvTy; 4579 4580 // As an extension, we allow cast to/from void* to function pointer. 4581 assert(rhptee->isFunctionType()); 4582 return FunctionVoidPointer; 4583 } 4584 4585 if (rhptee->isVoidType()) { 4586 if (lhptee->isIncompleteOrObjectType()) 4587 return ConvTy; 4588 4589 // As an extension, we allow cast to/from void* to function pointer. 4590 assert(lhptee->isFunctionType()); 4591 return FunctionVoidPointer; 4592 } 4593 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4594 // unqualified versions of compatible types, ... 4595 lhptee = lhptee.getUnqualifiedType(); 4596 rhptee = rhptee.getUnqualifiedType(); 4597 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4598 // Check if the pointee types are compatible ignoring the sign. 4599 // We explicitly check for char so that we catch "char" vs 4600 // "unsigned char" on systems where "char" is unsigned. 4601 if (lhptee->isCharType()) 4602 lhptee = Context.UnsignedCharTy; 4603 else if (lhptee->hasSignedIntegerRepresentation()) 4604 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4605 4606 if (rhptee->isCharType()) 4607 rhptee = Context.UnsignedCharTy; 4608 else if (rhptee->hasSignedIntegerRepresentation()) 4609 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4610 4611 if (lhptee == rhptee) { 4612 // Types are compatible ignoring the sign. Qualifier incompatibility 4613 // takes priority over sign incompatibility because the sign 4614 // warning can be disabled. 4615 if (ConvTy != Compatible) 4616 return ConvTy; 4617 return IncompatiblePointerSign; 4618 } 4619 4620 // If we are a multi-level pointer, it's possible that our issue is simply 4621 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4622 // the eventual target type is the same and the pointers have the same 4623 // level of indirection, this must be the issue. 4624 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4625 do { 4626 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4627 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4628 4629 lhptee = Context.getCanonicalType(lhptee); 4630 rhptee = Context.getCanonicalType(rhptee); 4631 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4632 4633 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4634 return IncompatibleNestedPointerQualifiers; 4635 } 4636 4637 // General pointer incompatibility takes priority over qualifiers. 4638 return IncompatiblePointer; 4639 } 4640 return ConvTy; 4641} 4642 4643/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4644/// block pointer types are compatible or whether a block and normal pointer 4645/// are compatible. It is more restrict than comparing two function pointer 4646// types. 4647Sema::AssignConvertType 4648Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4649 QualType rhsType) { 4650 QualType lhptee, rhptee; 4651 4652 // get the "pointed to" type (ignoring qualifiers at the top level) 4653 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4654 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4655 4656 // make sure we operate on the canonical type 4657 lhptee = Context.getCanonicalType(lhptee); 4658 rhptee = Context.getCanonicalType(rhptee); 4659 4660 AssignConvertType ConvTy = Compatible; 4661 4662 // For blocks we enforce that qualifiers are identical. 4663 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4664 ConvTy = CompatiblePointerDiscardsQualifiers; 4665 4666 if (!getLangOptions().CPlusPlus) { 4667 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4668 return IncompatibleBlockPointer; 4669 } 4670 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4671 return IncompatibleBlockPointer; 4672 return ConvTy; 4673} 4674 4675/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4676/// for assignment compatibility. 4677Sema::AssignConvertType 4678Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4679 if (lhsType->isObjCBuiltinType()) { 4680 // Class is not compatible with ObjC object pointers. 4681 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4682 !rhsType->isObjCQualifiedClassType()) 4683 return IncompatiblePointer; 4684 return Compatible; 4685 } 4686 if (rhsType->isObjCBuiltinType()) { 4687 // Class is not compatible with ObjC object pointers. 4688 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4689 !lhsType->isObjCQualifiedClassType()) 4690 return IncompatiblePointer; 4691 return Compatible; 4692 } 4693 QualType lhptee = 4694 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4695 QualType rhptee = 4696 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4697 // make sure we operate on the canonical type 4698 lhptee = Context.getCanonicalType(lhptee); 4699 rhptee = Context.getCanonicalType(rhptee); 4700 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4701 return CompatiblePointerDiscardsQualifiers; 4702 4703 if (Context.typesAreCompatible(lhsType, rhsType)) 4704 return Compatible; 4705 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4706 return IncompatibleObjCQualifiedId; 4707 return IncompatiblePointer; 4708} 4709 4710/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4711/// has code to accommodate several GCC extensions when type checking 4712/// pointers. Here are some objectionable examples that GCC considers warnings: 4713/// 4714/// int a, *pint; 4715/// short *pshort; 4716/// struct foo *pfoo; 4717/// 4718/// pint = pshort; // warning: assignment from incompatible pointer type 4719/// a = pint; // warning: assignment makes integer from pointer without a cast 4720/// pint = a; // warning: assignment makes pointer from integer without a cast 4721/// pint = pfoo; // warning: assignment from incompatible pointer type 4722/// 4723/// As a result, the code for dealing with pointers is more complex than the 4724/// C99 spec dictates. 4725/// 4726Sema::AssignConvertType 4727Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4728 // Get canonical types. We're not formatting these types, just comparing 4729 // them. 4730 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4731 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4732 4733 if (lhsType == rhsType) 4734 return Compatible; // Common case: fast path an exact match. 4735 4736 if ((lhsType->isObjCClassType() && 4737 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4738 (rhsType->isObjCClassType() && 4739 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4740 return Compatible; 4741 } 4742 4743 // If the left-hand side is a reference type, then we are in a 4744 // (rare!) case where we've allowed the use of references in C, 4745 // e.g., as a parameter type in a built-in function. In this case, 4746 // just make sure that the type referenced is compatible with the 4747 // right-hand side type. The caller is responsible for adjusting 4748 // lhsType so that the resulting expression does not have reference 4749 // type. 4750 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4751 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4752 return Compatible; 4753 return Incompatible; 4754 } 4755 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4756 // to the same ExtVector type. 4757 if (lhsType->isExtVectorType()) { 4758 if (rhsType->isExtVectorType()) 4759 return lhsType == rhsType ? Compatible : Incompatible; 4760 if (rhsType->isArithmeticType()) 4761 return Compatible; 4762 } 4763 4764 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4765 if (lhsType->isVectorType() && rhsType->isVectorType()) { 4766 // If we are allowing lax vector conversions, and LHS and RHS are both 4767 // vectors, the total size only needs to be the same. This is a bitcast; 4768 // no bits are changed but the result type is different. 4769 if (getLangOptions().LaxVectorConversions && 4770 (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) 4771 return IncompatibleVectors; 4772 4773 // Allow assignments of an AltiVec vector type to an equivalent GCC 4774 // vector type and vice versa 4775 if (Context.areCompatibleVectorTypes(lhsType, rhsType)) 4776 return Compatible; 4777 } 4778 return Incompatible; 4779 } 4780 4781 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 4782 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) 4783 return Compatible; 4784 4785 if (isa<PointerType>(lhsType)) { 4786 if (rhsType->isIntegerType()) 4787 return IntToPointer; 4788 4789 if (isa<PointerType>(rhsType)) 4790 return CheckPointerTypesForAssignment(lhsType, rhsType); 4791 4792 // In general, C pointers are not compatible with ObjC object pointers. 4793 if (isa<ObjCObjectPointerType>(rhsType)) { 4794 if (lhsType->isVoidPointerType()) // an exception to the rule. 4795 return Compatible; 4796 return IncompatiblePointer; 4797 } 4798 if (rhsType->getAs<BlockPointerType>()) { 4799 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4800 return Compatible; 4801 4802 // Treat block pointers as objects. 4803 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4804 return Compatible; 4805 } 4806 return Incompatible; 4807 } 4808 4809 if (isa<BlockPointerType>(lhsType)) { 4810 if (rhsType->isIntegerType()) 4811 return IntToBlockPointer; 4812 4813 // Treat block pointers as objects. 4814 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4815 return Compatible; 4816 4817 if (rhsType->isBlockPointerType()) 4818 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4819 4820 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4821 if (RHSPT->getPointeeType()->isVoidType()) 4822 return Compatible; 4823 } 4824 return Incompatible; 4825 } 4826 4827 if (isa<ObjCObjectPointerType>(lhsType)) { 4828 if (rhsType->isIntegerType()) 4829 return IntToPointer; 4830 4831 // In general, C pointers are not compatible with ObjC object pointers. 4832 if (isa<PointerType>(rhsType)) { 4833 if (rhsType->isVoidPointerType()) // an exception to the rule. 4834 return Compatible; 4835 return IncompatiblePointer; 4836 } 4837 if (rhsType->isObjCObjectPointerType()) { 4838 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4839 } 4840 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4841 if (RHSPT->getPointeeType()->isVoidType()) 4842 return Compatible; 4843 } 4844 // Treat block pointers as objects. 4845 if (rhsType->isBlockPointerType()) 4846 return Compatible; 4847 return Incompatible; 4848 } 4849 if (isa<PointerType>(rhsType)) { 4850 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4851 if (lhsType == Context.BoolTy) 4852 return Compatible; 4853 4854 if (lhsType->isIntegerType()) 4855 return PointerToInt; 4856 4857 if (isa<PointerType>(lhsType)) 4858 return CheckPointerTypesForAssignment(lhsType, rhsType); 4859 4860 if (isa<BlockPointerType>(lhsType) && 4861 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4862 return Compatible; 4863 return Incompatible; 4864 } 4865 if (isa<ObjCObjectPointerType>(rhsType)) { 4866 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4867 if (lhsType == Context.BoolTy) 4868 return Compatible; 4869 4870 if (lhsType->isIntegerType()) 4871 return PointerToInt; 4872 4873 // In general, C pointers are not compatible with ObjC object pointers. 4874 if (isa<PointerType>(lhsType)) { 4875 if (lhsType->isVoidPointerType()) // an exception to the rule. 4876 return Compatible; 4877 return IncompatiblePointer; 4878 } 4879 if (isa<BlockPointerType>(lhsType) && 4880 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4881 return Compatible; 4882 return Incompatible; 4883 } 4884 4885 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4886 if (Context.typesAreCompatible(lhsType, rhsType)) 4887 return Compatible; 4888 } 4889 return Incompatible; 4890} 4891 4892/// \brief Constructs a transparent union from an expression that is 4893/// used to initialize the transparent union. 4894static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4895 QualType UnionType, FieldDecl *Field) { 4896 // Build an initializer list that designates the appropriate member 4897 // of the transparent union. 4898 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 4899 &E, 1, 4900 SourceLocation()); 4901 Initializer->setType(UnionType); 4902 Initializer->setInitializedFieldInUnion(Field); 4903 4904 // Build a compound literal constructing a value of the transparent 4905 // union type from this initializer list. 4906 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4907 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4908 Initializer, false); 4909} 4910 4911Sema::AssignConvertType 4912Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4913 QualType FromType = rExpr->getType(); 4914 4915 // If the ArgType is a Union type, we want to handle a potential 4916 // transparent_union GCC extension. 4917 const RecordType *UT = ArgType->getAsUnionType(); 4918 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4919 return Incompatible; 4920 4921 // The field to initialize within the transparent union. 4922 RecordDecl *UD = UT->getDecl(); 4923 FieldDecl *InitField = 0; 4924 // It's compatible if the expression matches any of the fields. 4925 for (RecordDecl::field_iterator it = UD->field_begin(), 4926 itend = UD->field_end(); 4927 it != itend; ++it) { 4928 if (it->getType()->isPointerType()) { 4929 // If the transparent union contains a pointer type, we allow: 4930 // 1) void pointer 4931 // 2) null pointer constant 4932 if (FromType->isPointerType()) 4933 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4934 ImpCastExprToType(rExpr, it->getType(), CK_BitCast); 4935 InitField = *it; 4936 break; 4937 } 4938 4939 if (rExpr->isNullPointerConstant(Context, 4940 Expr::NPC_ValueDependentIsNull)) { 4941 ImpCastExprToType(rExpr, it->getType(), CK_IntegralToPointer); 4942 InitField = *it; 4943 break; 4944 } 4945 } 4946 4947 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4948 == Compatible) { 4949 InitField = *it; 4950 break; 4951 } 4952 } 4953 4954 if (!InitField) 4955 return Incompatible; 4956 4957 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4958 return Compatible; 4959} 4960 4961Sema::AssignConvertType 4962Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4963 if (getLangOptions().CPlusPlus) { 4964 if (!lhsType->isRecordType()) { 4965 // C++ 5.17p3: If the left operand is not of class type, the 4966 // expression is implicitly converted (C++ 4) to the 4967 // cv-unqualified type of the left operand. 4968 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4969 AA_Assigning)) 4970 return Incompatible; 4971 return Compatible; 4972 } 4973 4974 // FIXME: Currently, we fall through and treat C++ classes like C 4975 // structures. 4976 } 4977 4978 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4979 // a null pointer constant. 4980 if ((lhsType->isPointerType() || 4981 lhsType->isObjCObjectPointerType() || 4982 lhsType->isBlockPointerType()) 4983 && rExpr->isNullPointerConstant(Context, 4984 Expr::NPC_ValueDependentIsNull)) { 4985 ImpCastExprToType(rExpr, lhsType, CK_Unknown); 4986 return Compatible; 4987 } 4988 4989 // This check seems unnatural, however it is necessary to ensure the proper 4990 // conversion of functions/arrays. If the conversion were done for all 4991 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4992 // expressions that suppress this implicit conversion (&, sizeof). 4993 // 4994 // Suppress this for references: C++ 8.5.3p5. 4995 if (!lhsType->isReferenceType()) 4996 DefaultFunctionArrayLvalueConversion(rExpr); 4997 4998 Sema::AssignConvertType result = 4999 CheckAssignmentConstraints(lhsType, rExpr->getType()); 5000 5001 // C99 6.5.16.1p2: The value of the right operand is converted to the 5002 // type of the assignment expression. 5003 // CheckAssignmentConstraints allows the left-hand side to be a reference, 5004 // so that we can use references in built-in functions even in C. 5005 // The getNonReferenceType() call makes sure that the resulting expression 5006 // does not have reference type. 5007 if (result != Incompatible && rExpr->getType() != lhsType) 5008 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), 5009 CK_Unknown); 5010 return result; 5011} 5012 5013QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5014 Diag(Loc, diag::err_typecheck_invalid_operands) 5015 << lex->getType() << rex->getType() 5016 << lex->getSourceRange() << rex->getSourceRange(); 5017 return QualType(); 5018} 5019 5020QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5021 // For conversion purposes, we ignore any qualifiers. 5022 // For example, "const float" and "float" are equivalent. 5023 QualType lhsType = 5024 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 5025 QualType rhsType = 5026 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 5027 5028 // If the vector types are identical, return. 5029 if (lhsType == rhsType) 5030 return lhsType; 5031 5032 // Handle the case of a vector & extvector type of the same size and element 5033 // type. It would be nice if we only had one vector type someday. 5034 if (getLangOptions().LaxVectorConversions) { 5035 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5036 if (const VectorType *RV = rhsType->getAs<VectorType>()) { 5037 if (LV->getElementType() == RV->getElementType() && 5038 LV->getNumElements() == RV->getNumElements()) { 5039 if (lhsType->isExtVectorType()) { 5040 ImpCastExprToType(rex, lhsType, CK_BitCast); 5041 return lhsType; 5042 } 5043 5044 ImpCastExprToType(lex, rhsType, CK_BitCast); 5045 return rhsType; 5046 } else if (Context.getTypeSize(lhsType) ==Context.getTypeSize(rhsType)){ 5047 // If we are allowing lax vector conversions, and LHS and RHS are both 5048 // vectors, the total size only needs to be the same. This is a 5049 // bitcast; no bits are changed but the result type is different. 5050 ImpCastExprToType(rex, lhsType, CK_BitCast); 5051 return lhsType; 5052 } 5053 } 5054 } 5055 } 5056 5057 // Handle the case of equivalent AltiVec and GCC vector types 5058 if (lhsType->isVectorType() && rhsType->isVectorType() && 5059 Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5060 ImpCastExprToType(lex, rhsType, CK_BitCast); 5061 return rhsType; 5062 } 5063 5064 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5065 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5066 bool swapped = false; 5067 if (rhsType->isExtVectorType()) { 5068 swapped = true; 5069 std::swap(rex, lex); 5070 std::swap(rhsType, lhsType); 5071 } 5072 5073 // Handle the case of an ext vector and scalar. 5074 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5075 QualType EltTy = LV->getElementType(); 5076 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5077 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5078 ImpCastExprToType(rex, lhsType, CK_IntegralCast); 5079 if (swapped) std::swap(rex, lex); 5080 return lhsType; 5081 } 5082 } 5083 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5084 rhsType->isRealFloatingType()) { 5085 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5086 ImpCastExprToType(rex, lhsType, CK_FloatingCast); 5087 if (swapped) std::swap(rex, lex); 5088 return lhsType; 5089 } 5090 } 5091 } 5092 5093 // Vectors of different size or scalar and non-ext-vector are errors. 5094 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5095 << lex->getType() << rex->getType() 5096 << lex->getSourceRange() << rex->getSourceRange(); 5097 return QualType(); 5098} 5099 5100QualType Sema::CheckMultiplyDivideOperands( 5101 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5102 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5103 return CheckVectorOperands(Loc, lex, rex); 5104 5105 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5106 5107 if (!lex->getType()->isArithmeticType() || 5108 !rex->getType()->isArithmeticType()) 5109 return InvalidOperands(Loc, lex, rex); 5110 5111 // Check for division by zero. 5112 if (isDiv && 5113 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5114 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5115 << rex->getSourceRange()); 5116 5117 return compType; 5118} 5119 5120QualType Sema::CheckRemainderOperands( 5121 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5122 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5123 if (lex->getType()->hasIntegerRepresentation() && 5124 rex->getType()->hasIntegerRepresentation()) 5125 return CheckVectorOperands(Loc, lex, rex); 5126 return InvalidOperands(Loc, lex, rex); 5127 } 5128 5129 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5130 5131 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5132 return InvalidOperands(Loc, lex, rex); 5133 5134 // Check for remainder by zero. 5135 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5136 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5137 << rex->getSourceRange()); 5138 5139 return compType; 5140} 5141 5142QualType Sema::CheckAdditionOperands( // C99 6.5.6 5143 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5144 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5145 QualType compType = CheckVectorOperands(Loc, lex, rex); 5146 if (CompLHSTy) *CompLHSTy = compType; 5147 return compType; 5148 } 5149 5150 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5151 5152 // handle the common case first (both operands are arithmetic). 5153 if (lex->getType()->isArithmeticType() && 5154 rex->getType()->isArithmeticType()) { 5155 if (CompLHSTy) *CompLHSTy = compType; 5156 return compType; 5157 } 5158 5159 // Put any potential pointer into PExp 5160 Expr* PExp = lex, *IExp = rex; 5161 if (IExp->getType()->isAnyPointerType()) 5162 std::swap(PExp, IExp); 5163 5164 if (PExp->getType()->isAnyPointerType()) { 5165 5166 if (IExp->getType()->isIntegerType()) { 5167 QualType PointeeTy = PExp->getType()->getPointeeType(); 5168 5169 // Check for arithmetic on pointers to incomplete types. 5170 if (PointeeTy->isVoidType()) { 5171 if (getLangOptions().CPlusPlus) { 5172 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5173 << lex->getSourceRange() << rex->getSourceRange(); 5174 return QualType(); 5175 } 5176 5177 // GNU extension: arithmetic on pointer to void 5178 Diag(Loc, diag::ext_gnu_void_ptr) 5179 << lex->getSourceRange() << rex->getSourceRange(); 5180 } else if (PointeeTy->isFunctionType()) { 5181 if (getLangOptions().CPlusPlus) { 5182 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5183 << lex->getType() << lex->getSourceRange(); 5184 return QualType(); 5185 } 5186 5187 // GNU extension: arithmetic on pointer to function 5188 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5189 << lex->getType() << lex->getSourceRange(); 5190 } else { 5191 // Check if we require a complete type. 5192 if (((PExp->getType()->isPointerType() && 5193 !PExp->getType()->isDependentType()) || 5194 PExp->getType()->isObjCObjectPointerType()) && 5195 RequireCompleteType(Loc, PointeeTy, 5196 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5197 << PExp->getSourceRange() 5198 << PExp->getType())) 5199 return QualType(); 5200 } 5201 // Diagnose bad cases where we step over interface counts. 5202 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5203 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5204 << PointeeTy << PExp->getSourceRange(); 5205 return QualType(); 5206 } 5207 5208 if (CompLHSTy) { 5209 QualType LHSTy = Context.isPromotableBitField(lex); 5210 if (LHSTy.isNull()) { 5211 LHSTy = lex->getType(); 5212 if (LHSTy->isPromotableIntegerType()) 5213 LHSTy = Context.getPromotedIntegerType(LHSTy); 5214 } 5215 *CompLHSTy = LHSTy; 5216 } 5217 return PExp->getType(); 5218 } 5219 } 5220 5221 return InvalidOperands(Loc, lex, rex); 5222} 5223 5224// C99 6.5.6 5225QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5226 SourceLocation Loc, QualType* CompLHSTy) { 5227 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5228 QualType compType = CheckVectorOperands(Loc, lex, rex); 5229 if (CompLHSTy) *CompLHSTy = compType; 5230 return compType; 5231 } 5232 5233 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5234 5235 // Enforce type constraints: C99 6.5.6p3. 5236 5237 // Handle the common case first (both operands are arithmetic). 5238 if (lex->getType()->isArithmeticType() 5239 && rex->getType()->isArithmeticType()) { 5240 if (CompLHSTy) *CompLHSTy = compType; 5241 return compType; 5242 } 5243 5244 // Either ptr - int or ptr - ptr. 5245 if (lex->getType()->isAnyPointerType()) { 5246 QualType lpointee = lex->getType()->getPointeeType(); 5247 5248 // The LHS must be an completely-defined object type. 5249 5250 bool ComplainAboutVoid = false; 5251 Expr *ComplainAboutFunc = 0; 5252 if (lpointee->isVoidType()) { 5253 if (getLangOptions().CPlusPlus) { 5254 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5255 << lex->getSourceRange() << rex->getSourceRange(); 5256 return QualType(); 5257 } 5258 5259 // GNU C extension: arithmetic on pointer to void 5260 ComplainAboutVoid = true; 5261 } else if (lpointee->isFunctionType()) { 5262 if (getLangOptions().CPlusPlus) { 5263 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5264 << lex->getType() << lex->getSourceRange(); 5265 return QualType(); 5266 } 5267 5268 // GNU C extension: arithmetic on pointer to function 5269 ComplainAboutFunc = lex; 5270 } else if (!lpointee->isDependentType() && 5271 RequireCompleteType(Loc, lpointee, 5272 PDiag(diag::err_typecheck_sub_ptr_object) 5273 << lex->getSourceRange() 5274 << lex->getType())) 5275 return QualType(); 5276 5277 // Diagnose bad cases where we step over interface counts. 5278 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5279 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5280 << lpointee << lex->getSourceRange(); 5281 return QualType(); 5282 } 5283 5284 // The result type of a pointer-int computation is the pointer type. 5285 if (rex->getType()->isIntegerType()) { 5286 if (ComplainAboutVoid) 5287 Diag(Loc, diag::ext_gnu_void_ptr) 5288 << lex->getSourceRange() << rex->getSourceRange(); 5289 if (ComplainAboutFunc) 5290 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5291 << ComplainAboutFunc->getType() 5292 << ComplainAboutFunc->getSourceRange(); 5293 5294 if (CompLHSTy) *CompLHSTy = lex->getType(); 5295 return lex->getType(); 5296 } 5297 5298 // Handle pointer-pointer subtractions. 5299 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5300 QualType rpointee = RHSPTy->getPointeeType(); 5301 5302 // RHS must be a completely-type object type. 5303 // Handle the GNU void* extension. 5304 if (rpointee->isVoidType()) { 5305 if (getLangOptions().CPlusPlus) { 5306 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5307 << lex->getSourceRange() << rex->getSourceRange(); 5308 return QualType(); 5309 } 5310 5311 ComplainAboutVoid = true; 5312 } else if (rpointee->isFunctionType()) { 5313 if (getLangOptions().CPlusPlus) { 5314 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5315 << rex->getType() << rex->getSourceRange(); 5316 return QualType(); 5317 } 5318 5319 // GNU extension: arithmetic on pointer to function 5320 if (!ComplainAboutFunc) 5321 ComplainAboutFunc = rex; 5322 } else if (!rpointee->isDependentType() && 5323 RequireCompleteType(Loc, rpointee, 5324 PDiag(diag::err_typecheck_sub_ptr_object) 5325 << rex->getSourceRange() 5326 << rex->getType())) 5327 return QualType(); 5328 5329 if (getLangOptions().CPlusPlus) { 5330 // Pointee types must be the same: C++ [expr.add] 5331 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5332 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5333 << lex->getType() << rex->getType() 5334 << lex->getSourceRange() << rex->getSourceRange(); 5335 return QualType(); 5336 } 5337 } else { 5338 // Pointee types must be compatible C99 6.5.6p3 5339 if (!Context.typesAreCompatible( 5340 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5341 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5342 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5343 << lex->getType() << rex->getType() 5344 << lex->getSourceRange() << rex->getSourceRange(); 5345 return QualType(); 5346 } 5347 } 5348 5349 if (ComplainAboutVoid) 5350 Diag(Loc, diag::ext_gnu_void_ptr) 5351 << lex->getSourceRange() << rex->getSourceRange(); 5352 if (ComplainAboutFunc) 5353 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5354 << ComplainAboutFunc->getType() 5355 << ComplainAboutFunc->getSourceRange(); 5356 5357 if (CompLHSTy) *CompLHSTy = lex->getType(); 5358 return Context.getPointerDiffType(); 5359 } 5360 } 5361 5362 return InvalidOperands(Loc, lex, rex); 5363} 5364 5365// C99 6.5.7 5366QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5367 bool isCompAssign) { 5368 // C99 6.5.7p2: Each of the operands shall have integer type. 5369 if (!lex->getType()->hasIntegerRepresentation() || 5370 !rex->getType()->hasIntegerRepresentation()) 5371 return InvalidOperands(Loc, lex, rex); 5372 5373 // Vector shifts promote their scalar inputs to vector type. 5374 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5375 return CheckVectorOperands(Loc, lex, rex); 5376 5377 // Shifts don't perform usual arithmetic conversions, they just do integer 5378 // promotions on each operand. C99 6.5.7p3 5379 QualType LHSTy = Context.isPromotableBitField(lex); 5380 if (LHSTy.isNull()) { 5381 LHSTy = lex->getType(); 5382 if (LHSTy->isPromotableIntegerType()) 5383 LHSTy = Context.getPromotedIntegerType(LHSTy); 5384 } 5385 if (!isCompAssign) 5386 ImpCastExprToType(lex, LHSTy, CK_IntegralCast); 5387 5388 UsualUnaryConversions(rex); 5389 5390 // Sanity-check shift operands 5391 llvm::APSInt Right; 5392 // Check right/shifter operand 5393 if (!rex->isValueDependent() && 5394 rex->isIntegerConstantExpr(Right, Context)) { 5395 if (Right.isNegative()) 5396 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5397 else { 5398 llvm::APInt LeftBits(Right.getBitWidth(), 5399 Context.getTypeSize(lex->getType())); 5400 if (Right.uge(LeftBits)) 5401 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5402 } 5403 } 5404 5405 // "The type of the result is that of the promoted left operand." 5406 return LHSTy; 5407} 5408 5409static bool IsWithinTemplateSpecialization(Decl *D) { 5410 if (DeclContext *DC = D->getDeclContext()) { 5411 if (isa<ClassTemplateSpecializationDecl>(DC)) 5412 return true; 5413 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 5414 return FD->isFunctionTemplateSpecialization(); 5415 } 5416 return false; 5417} 5418 5419// C99 6.5.8, C++ [expr.rel] 5420QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5421 unsigned OpaqueOpc, bool isRelational) { 5422 BinaryOperatorKind Opc = (BinaryOperatorKind) OpaqueOpc; 5423 5424 // Handle vector comparisons separately. 5425 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5426 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5427 5428 QualType lType = lex->getType(); 5429 QualType rType = rex->getType(); 5430 5431 if (!lType->hasFloatingRepresentation() && 5432 !(lType->isBlockPointerType() && isRelational)) { 5433 // For non-floating point types, check for self-comparisons of the form 5434 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5435 // often indicate logic errors in the program. 5436 // 5437 // NOTE: Don't warn about comparison expressions resulting from macro 5438 // expansion. Also don't warn about comparisons which are only self 5439 // comparisons within a template specialization. The warnings should catch 5440 // obvious cases in the definition of the template anyways. The idea is to 5441 // warn when the typed comparison operator will always evaluate to the same 5442 // result. 5443 Expr *LHSStripped = lex->IgnoreParens(); 5444 Expr *RHSStripped = rex->IgnoreParens(); 5445 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 5446 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 5447 if (DRL->getDecl() == DRR->getDecl() && !Loc.isMacroID() && 5448 !IsWithinTemplateSpecialization(DRL->getDecl())) { 5449 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5450 << 0 // self- 5451 << (Opc == BO_EQ 5452 || Opc == BO_LE 5453 || Opc == BO_GE)); 5454 } else if (lType->isArrayType() && rType->isArrayType() && 5455 !DRL->getDecl()->getType()->isReferenceType() && 5456 !DRR->getDecl()->getType()->isReferenceType()) { 5457 // what is it always going to eval to? 5458 char always_evals_to; 5459 switch(Opc) { 5460 case BO_EQ: // e.g. array1 == array2 5461 always_evals_to = 0; // false 5462 break; 5463 case BO_NE: // e.g. array1 != array2 5464 always_evals_to = 1; // true 5465 break; 5466 default: 5467 // best we can say is 'a constant' 5468 always_evals_to = 2; // e.g. array1 <= array2 5469 break; 5470 } 5471 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5472 << 1 // array 5473 << always_evals_to); 5474 } 5475 } 5476 } 5477 5478 if (isa<CastExpr>(LHSStripped)) 5479 LHSStripped = LHSStripped->IgnoreParenCasts(); 5480 if (isa<CastExpr>(RHSStripped)) 5481 RHSStripped = RHSStripped->IgnoreParenCasts(); 5482 5483 // Warn about comparisons against a string constant (unless the other 5484 // operand is null), the user probably wants strcmp. 5485 Expr *literalString = 0; 5486 Expr *literalStringStripped = 0; 5487 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5488 !RHSStripped->isNullPointerConstant(Context, 5489 Expr::NPC_ValueDependentIsNull)) { 5490 literalString = lex; 5491 literalStringStripped = LHSStripped; 5492 } else if ((isa<StringLiteral>(RHSStripped) || 5493 isa<ObjCEncodeExpr>(RHSStripped)) && 5494 !LHSStripped->isNullPointerConstant(Context, 5495 Expr::NPC_ValueDependentIsNull)) { 5496 literalString = rex; 5497 literalStringStripped = RHSStripped; 5498 } 5499 5500 if (literalString) { 5501 std::string resultComparison; 5502 switch (Opc) { 5503 case BO_LT: resultComparison = ") < 0"; break; 5504 case BO_GT: resultComparison = ") > 0"; break; 5505 case BO_LE: resultComparison = ") <= 0"; break; 5506 case BO_GE: resultComparison = ") >= 0"; break; 5507 case BO_EQ: resultComparison = ") == 0"; break; 5508 case BO_NE: resultComparison = ") != 0"; break; 5509 default: assert(false && "Invalid comparison operator"); 5510 } 5511 5512 DiagRuntimeBehavior(Loc, 5513 PDiag(diag::warn_stringcompare) 5514 << isa<ObjCEncodeExpr>(literalStringStripped) 5515 << literalString->getSourceRange()); 5516 } 5517 } 5518 5519 // C99 6.5.8p3 / C99 6.5.9p4 5520 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5521 UsualArithmeticConversions(lex, rex); 5522 else { 5523 UsualUnaryConversions(lex); 5524 UsualUnaryConversions(rex); 5525 } 5526 5527 lType = lex->getType(); 5528 rType = rex->getType(); 5529 5530 // The result of comparisons is 'bool' in C++, 'int' in C. 5531 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5532 5533 if (isRelational) { 5534 if (lType->isRealType() && rType->isRealType()) 5535 return ResultTy; 5536 } else { 5537 // Check for comparisons of floating point operands using != and ==. 5538 if (lType->hasFloatingRepresentation()) 5539 CheckFloatComparison(Loc,lex,rex); 5540 5541 if (lType->isArithmeticType() && rType->isArithmeticType()) 5542 return ResultTy; 5543 } 5544 5545 bool LHSIsNull = lex->isNullPointerConstant(Context, 5546 Expr::NPC_ValueDependentIsNull); 5547 bool RHSIsNull = rex->isNullPointerConstant(Context, 5548 Expr::NPC_ValueDependentIsNull); 5549 5550 // All of the following pointer-related warnings are GCC extensions, except 5551 // when handling null pointer constants. 5552 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5553 QualType LCanPointeeTy = 5554 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5555 QualType RCanPointeeTy = 5556 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5557 5558 if (getLangOptions().CPlusPlus) { 5559 if (LCanPointeeTy == RCanPointeeTy) 5560 return ResultTy; 5561 if (!isRelational && 5562 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5563 // Valid unless comparison between non-null pointer and function pointer 5564 // This is a gcc extension compatibility comparison. 5565 // In a SFINAE context, we treat this as a hard error to maintain 5566 // conformance with the C++ standard. 5567 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5568 && !LHSIsNull && !RHSIsNull) { 5569 Diag(Loc, 5570 isSFINAEContext()? 5571 diag::err_typecheck_comparison_of_fptr_to_void 5572 : diag::ext_typecheck_comparison_of_fptr_to_void) 5573 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5574 5575 if (isSFINAEContext()) 5576 return QualType(); 5577 5578 ImpCastExprToType(rex, lType, CK_BitCast); 5579 return ResultTy; 5580 } 5581 } 5582 // C++ [expr.rel]p2: 5583 // [...] Pointer conversions (4.10) and qualification 5584 // conversions (4.4) are performed on pointer operands (or on 5585 // a pointer operand and a null pointer constant) to bring 5586 // them to their composite pointer type. [...] 5587 // 5588 // C++ [expr.eq]p1 uses the same notion for (in)equality 5589 // comparisons of pointers. 5590 bool NonStandardCompositeType = false; 5591 QualType T = FindCompositePointerType(Loc, lex, rex, 5592 isSFINAEContext()? 0 : &NonStandardCompositeType); 5593 if (T.isNull()) { 5594 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5595 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5596 return QualType(); 5597 } else if (NonStandardCompositeType) { 5598 Diag(Loc, 5599 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5600 << lType << rType << T 5601 << lex->getSourceRange() << rex->getSourceRange(); 5602 } 5603 5604 ImpCastExprToType(lex, T, CK_BitCast); 5605 ImpCastExprToType(rex, T, CK_BitCast); 5606 return ResultTy; 5607 } 5608 // C99 6.5.9p2 and C99 6.5.8p2 5609 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5610 RCanPointeeTy.getUnqualifiedType())) { 5611 // Valid unless a relational comparison of function pointers 5612 if (isRelational && LCanPointeeTy->isFunctionType()) { 5613 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5614 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5615 } 5616 } else if (!isRelational && 5617 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5618 // Valid unless comparison between non-null pointer and function pointer 5619 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5620 && !LHSIsNull && !RHSIsNull) { 5621 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5622 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5623 } 5624 } else { 5625 // Invalid 5626 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5627 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5628 } 5629 if (LCanPointeeTy != RCanPointeeTy) 5630 ImpCastExprToType(rex, lType, CK_BitCast); 5631 return ResultTy; 5632 } 5633 5634 if (getLangOptions().CPlusPlus) { 5635 // Comparison of pointers with null pointer constants and equality 5636 // comparisons of member pointers to null pointer constants. 5637 if (RHSIsNull && 5638 (lType->isPointerType() || 5639 (!isRelational && lType->isMemberPointerType()))) { 5640 ImpCastExprToType(rex, lType, 5641 lType->isMemberPointerType() 5642 ? CK_NullToMemberPointer 5643 : CK_IntegralToPointer); 5644 return ResultTy; 5645 } 5646 if (LHSIsNull && 5647 (rType->isPointerType() || 5648 (!isRelational && rType->isMemberPointerType()))) { 5649 ImpCastExprToType(lex, rType, 5650 rType->isMemberPointerType() 5651 ? CK_NullToMemberPointer 5652 : CK_IntegralToPointer); 5653 return ResultTy; 5654 } 5655 5656 // Comparison of member pointers. 5657 if (!isRelational && 5658 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5659 // C++ [expr.eq]p2: 5660 // In addition, pointers to members can be compared, or a pointer to 5661 // member and a null pointer constant. Pointer to member conversions 5662 // (4.11) and qualification conversions (4.4) are performed to bring 5663 // them to a common type. If one operand is a null pointer constant, 5664 // the common type is the type of the other operand. Otherwise, the 5665 // common type is a pointer to member type similar (4.4) to the type 5666 // of one of the operands, with a cv-qualification signature (4.4) 5667 // that is the union of the cv-qualification signatures of the operand 5668 // types. 5669 bool NonStandardCompositeType = false; 5670 QualType T = FindCompositePointerType(Loc, lex, rex, 5671 isSFINAEContext()? 0 : &NonStandardCompositeType); 5672 if (T.isNull()) { 5673 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5674 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5675 return QualType(); 5676 } else if (NonStandardCompositeType) { 5677 Diag(Loc, 5678 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5679 << lType << rType << T 5680 << lex->getSourceRange() << rex->getSourceRange(); 5681 } 5682 5683 ImpCastExprToType(lex, T, CK_BitCast); 5684 ImpCastExprToType(rex, T, CK_BitCast); 5685 return ResultTy; 5686 } 5687 5688 // Comparison of nullptr_t with itself. 5689 if (lType->isNullPtrType() && rType->isNullPtrType()) 5690 return ResultTy; 5691 } 5692 5693 // Handle block pointer types. 5694 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5695 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5696 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5697 5698 if (!LHSIsNull && !RHSIsNull && 5699 !Context.typesAreCompatible(lpointee, rpointee)) { 5700 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5701 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5702 } 5703 ImpCastExprToType(rex, lType, CK_BitCast); 5704 return ResultTy; 5705 } 5706 // Allow block pointers to be compared with null pointer constants. 5707 if (!isRelational 5708 && ((lType->isBlockPointerType() && rType->isPointerType()) 5709 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5710 if (!LHSIsNull && !RHSIsNull) { 5711 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5712 ->getPointeeType()->isVoidType()) 5713 || (lType->isPointerType() && lType->getAs<PointerType>() 5714 ->getPointeeType()->isVoidType()))) 5715 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5716 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5717 } 5718 ImpCastExprToType(rex, lType, CK_BitCast); 5719 return ResultTy; 5720 } 5721 5722 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5723 if (lType->isPointerType() || rType->isPointerType()) { 5724 const PointerType *LPT = lType->getAs<PointerType>(); 5725 const PointerType *RPT = rType->getAs<PointerType>(); 5726 bool LPtrToVoid = LPT ? 5727 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5728 bool RPtrToVoid = RPT ? 5729 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5730 5731 if (!LPtrToVoid && !RPtrToVoid && 5732 !Context.typesAreCompatible(lType, rType)) { 5733 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5734 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5735 } 5736 ImpCastExprToType(rex, lType, CK_BitCast); 5737 return ResultTy; 5738 } 5739 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5740 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5741 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5742 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5743 ImpCastExprToType(rex, lType, CK_BitCast); 5744 return ResultTy; 5745 } 5746 } 5747 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 5748 (lType->isIntegerType() && rType->isAnyPointerType())) { 5749 unsigned DiagID = 0; 5750 bool isError = false; 5751 if ((LHSIsNull && lType->isIntegerType()) || 5752 (RHSIsNull && rType->isIntegerType())) { 5753 if (isRelational && !getLangOptions().CPlusPlus) 5754 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5755 } else if (isRelational && !getLangOptions().CPlusPlus) 5756 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5757 else if (getLangOptions().CPlusPlus) { 5758 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 5759 isError = true; 5760 } else 5761 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5762 5763 if (DiagID) { 5764 Diag(Loc, DiagID) 5765 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5766 if (isError) 5767 return QualType(); 5768 } 5769 5770 if (lType->isIntegerType()) 5771 ImpCastExprToType(lex, rType, CK_IntegralToPointer); 5772 else 5773 ImpCastExprToType(rex, lType, CK_IntegralToPointer); 5774 return ResultTy; 5775 } 5776 5777 // Handle block pointers. 5778 if (!isRelational && RHSIsNull 5779 && lType->isBlockPointerType() && rType->isIntegerType()) { 5780 ImpCastExprToType(rex, lType, CK_IntegralToPointer); 5781 return ResultTy; 5782 } 5783 if (!isRelational && LHSIsNull 5784 && lType->isIntegerType() && rType->isBlockPointerType()) { 5785 ImpCastExprToType(lex, rType, CK_IntegralToPointer); 5786 return ResultTy; 5787 } 5788 return InvalidOperands(Loc, lex, rex); 5789} 5790 5791/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5792/// operates on extended vector types. Instead of producing an IntTy result, 5793/// like a scalar comparison, a vector comparison produces a vector of integer 5794/// types. 5795QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5796 SourceLocation Loc, 5797 bool isRelational) { 5798 // Check to make sure we're operating on vectors of the same type and width, 5799 // Allowing one side to be a scalar of element type. 5800 QualType vType = CheckVectorOperands(Loc, lex, rex); 5801 if (vType.isNull()) 5802 return vType; 5803 5804 QualType lType = lex->getType(); 5805 QualType rType = rex->getType(); 5806 5807 // For non-floating point types, check for self-comparisons of the form 5808 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5809 // often indicate logic errors in the program. 5810 if (!lType->hasFloatingRepresentation()) { 5811 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5812 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5813 if (DRL->getDecl() == DRR->getDecl()) 5814 DiagRuntimeBehavior(Loc, 5815 PDiag(diag::warn_comparison_always) 5816 << 0 // self- 5817 << 2 // "a constant" 5818 ); 5819 } 5820 5821 // Check for comparisons of floating point operands using != and ==. 5822 if (!isRelational && lType->hasFloatingRepresentation()) { 5823 assert (rType->hasFloatingRepresentation()); 5824 CheckFloatComparison(Loc,lex,rex); 5825 } 5826 5827 // Return the type for the comparison, which is the same as vector type for 5828 // integer vectors, or an integer type of identical size and number of 5829 // elements for floating point vectors. 5830 if (lType->hasIntegerRepresentation()) 5831 return lType; 5832 5833 const VectorType *VTy = lType->getAs<VectorType>(); 5834 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5835 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5836 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5837 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5838 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5839 5840 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5841 "Unhandled vector element size in vector compare"); 5842 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5843} 5844 5845inline QualType Sema::CheckBitwiseOperands( 5846 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5847 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5848 if (lex->getType()->hasIntegerRepresentation() && 5849 rex->getType()->hasIntegerRepresentation()) 5850 return CheckVectorOperands(Loc, lex, rex); 5851 5852 return InvalidOperands(Loc, lex, rex); 5853 } 5854 5855 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5856 5857 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5858 return compType; 5859 return InvalidOperands(Loc, lex, rex); 5860} 5861 5862inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5863 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 5864 5865 // Diagnose cases where the user write a logical and/or but probably meant a 5866 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 5867 // is a constant. 5868 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 5869 rex->getType()->isIntegerType() && !rex->isValueDependent() && 5870 // Don't warn in macros. 5871 !Loc.isMacroID()) { 5872 // If the RHS can be constant folded, and if it constant folds to something 5873 // that isn't 0 or 1 (which indicate a potential logical operation that 5874 // happened to fold to true/false) then warn. 5875 Expr::EvalResult Result; 5876 if (rex->Evaluate(Result, Context) && !Result.HasSideEffects && 5877 Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { 5878 Diag(Loc, diag::warn_logical_instead_of_bitwise) 5879 << rex->getSourceRange() 5880 << (Opc == BO_LAnd ? "&&" : "||") 5881 << (Opc == BO_LAnd ? "&" : "|"); 5882 } 5883 } 5884 5885 if (!Context.getLangOptions().CPlusPlus) { 5886 UsualUnaryConversions(lex); 5887 UsualUnaryConversions(rex); 5888 5889 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5890 return InvalidOperands(Loc, lex, rex); 5891 5892 return Context.IntTy; 5893 } 5894 5895 // The following is safe because we only use this method for 5896 // non-overloadable operands. 5897 5898 // C++ [expr.log.and]p1 5899 // C++ [expr.log.or]p1 5900 // The operands are both contextually converted to type bool. 5901 if (PerformContextuallyConvertToBool(lex) || 5902 PerformContextuallyConvertToBool(rex)) 5903 return InvalidOperands(Loc, lex, rex); 5904 5905 // C++ [expr.log.and]p2 5906 // C++ [expr.log.or]p2 5907 // The result is a bool. 5908 return Context.BoolTy; 5909} 5910 5911/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5912/// is a read-only property; return true if so. A readonly property expression 5913/// depends on various declarations and thus must be treated specially. 5914/// 5915static bool IsReadonlyProperty(Expr *E, Sema &S) { 5916 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5917 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5918 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5919 QualType BaseType = PropExpr->getBase()->getType(); 5920 if (const ObjCObjectPointerType *OPT = 5921 BaseType->getAsObjCInterfacePointerType()) 5922 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5923 if (S.isPropertyReadonly(PDecl, IFace)) 5924 return true; 5925 } 5926 } 5927 return false; 5928} 5929 5930/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5931/// emit an error and return true. If so, return false. 5932static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5933 SourceLocation OrigLoc = Loc; 5934 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5935 &Loc); 5936 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5937 IsLV = Expr::MLV_ReadonlyProperty; 5938 if (IsLV == Expr::MLV_Valid) 5939 return false; 5940 5941 unsigned Diag = 0; 5942 bool NeedType = false; 5943 switch (IsLV) { // C99 6.5.16p2 5944 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5945 case Expr::MLV_ArrayType: 5946 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5947 NeedType = true; 5948 break; 5949 case Expr::MLV_NotObjectType: 5950 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5951 NeedType = true; 5952 break; 5953 case Expr::MLV_LValueCast: 5954 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5955 break; 5956 case Expr::MLV_Valid: 5957 llvm_unreachable("did not take early return for MLV_Valid"); 5958 case Expr::MLV_InvalidExpression: 5959 case Expr::MLV_MemberFunction: 5960 case Expr::MLV_ClassTemporary: 5961 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5962 break; 5963 case Expr::MLV_IncompleteType: 5964 case Expr::MLV_IncompleteVoidType: 5965 return S.RequireCompleteType(Loc, E->getType(), 5966 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5967 << E->getSourceRange()); 5968 case Expr::MLV_DuplicateVectorComponents: 5969 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5970 break; 5971 case Expr::MLV_NotBlockQualified: 5972 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5973 break; 5974 case Expr::MLV_ReadonlyProperty: 5975 Diag = diag::error_readonly_property_assignment; 5976 break; 5977 case Expr::MLV_NoSetterProperty: 5978 Diag = diag::error_nosetter_property_assignment; 5979 break; 5980 case Expr::MLV_SubObjCPropertySetting: 5981 Diag = diag::error_no_subobject_property_setting; 5982 break; 5983 } 5984 5985 SourceRange Assign; 5986 if (Loc != OrigLoc) 5987 Assign = SourceRange(OrigLoc, OrigLoc); 5988 if (NeedType) 5989 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5990 else 5991 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5992 return true; 5993} 5994 5995 5996 5997// C99 6.5.16.1 5998QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5999 SourceLocation Loc, 6000 QualType CompoundType) { 6001 // Verify that LHS is a modifiable lvalue, and emit error if not. 6002 if (CheckForModifiableLvalue(LHS, Loc, *this)) 6003 return QualType(); 6004 6005 QualType LHSType = LHS->getType(); 6006 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 6007 AssignConvertType ConvTy; 6008 if (CompoundType.isNull()) { 6009 QualType LHSTy(LHSType); 6010 // Simple assignment "x = y". 6011 if (const ObjCImplicitSetterGetterRefExpr *OISGE = 6012 dyn_cast<ObjCImplicitSetterGetterRefExpr>(LHS)) { 6013 // If using property-dot syntax notation for assignment, and there is a 6014 // setter, RHS expression is being passed to the setter argument. So, 6015 // type conversion (and comparison) is RHS to setter's argument type. 6016 if (const ObjCMethodDecl *SetterMD = OISGE->getSetterMethod()) { 6017 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 6018 LHSTy = (*P)->getType(); 6019 } 6020 } 6021 6022 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 6023 // Special case of NSObject attributes on c-style pointer types. 6024 if (ConvTy == IncompatiblePointer && 6025 ((Context.isObjCNSObjectType(LHSType) && 6026 RHSType->isObjCObjectPointerType()) || 6027 (Context.isObjCNSObjectType(RHSType) && 6028 LHSType->isObjCObjectPointerType()))) 6029 ConvTy = Compatible; 6030 6031 // If the RHS is a unary plus or minus, check to see if they = and + are 6032 // right next to each other. If so, the user may have typo'd "x =+ 4" 6033 // instead of "x += 4". 6034 Expr *RHSCheck = RHS; 6035 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 6036 RHSCheck = ICE->getSubExpr(); 6037 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 6038 if ((UO->getOpcode() == UO_Plus || 6039 UO->getOpcode() == UO_Minus) && 6040 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 6041 // Only if the two operators are exactly adjacent. 6042 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 6043 // And there is a space or other character before the subexpr of the 6044 // unary +/-. We don't want to warn on "x=-1". 6045 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 6046 UO->getSubExpr()->getLocStart().isFileID()) { 6047 Diag(Loc, diag::warn_not_compound_assign) 6048 << (UO->getOpcode() == UO_Plus ? "+" : "-") 6049 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 6050 } 6051 } 6052 } else { 6053 // Compound assignment "x += y" 6054 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 6055 } 6056 6057 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 6058 RHS, AA_Assigning)) 6059 return QualType(); 6060 6061 6062 // Check to see if the destination operand is a dereferenced null pointer. If 6063 // so, and if not volatile-qualified, this is undefined behavior that the 6064 // optimizer will delete, so warn about it. People sometimes try to use this 6065 // to get a deterministic trap and are surprised by clang's behavior. This 6066 // only handles the pattern "*null = whatever", which is a very syntactic 6067 // check. 6068 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 6069 if (UO->getOpcode() == UO_Deref && 6070 UO->getSubExpr()->IgnoreParenCasts()-> 6071 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 6072 !UO->getType().isVolatileQualified()) { 6073 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 6074 << UO->getSubExpr()->getSourceRange(); 6075 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 6076 } 6077 6078 // C99 6.5.16p3: The type of an assignment expression is the type of the 6079 // left operand unless the left operand has qualified type, in which case 6080 // it is the unqualified version of the type of the left operand. 6081 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 6082 // is converted to the type of the assignment expression (above). 6083 // C++ 5.17p1: the type of the assignment expression is that of its left 6084 // operand. 6085 return LHSType.getUnqualifiedType(); 6086} 6087 6088// C99 6.5.17 6089QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 6090 DiagnoseUnusedExprResult(LHS); 6091 6092 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 6093 // C++ does not perform this conversion (C++ [expr.comma]p1). 6094 if (!getLangOptions().CPlusPlus) 6095 DefaultFunctionArrayLvalueConversion(RHS); 6096 6097 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 6098 // incomplete in C++). 6099 6100 return RHS->getType(); 6101} 6102 6103/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 6104/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 6105QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 6106 bool isInc, bool isPrefix) { 6107 if (Op->isTypeDependent()) 6108 return Context.DependentTy; 6109 6110 QualType ResType = Op->getType(); 6111 assert(!ResType.isNull() && "no type for increment/decrement expression"); 6112 6113 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 6114 // Decrement of bool is not allowed. 6115 if (!isInc) { 6116 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 6117 return QualType(); 6118 } 6119 // Increment of bool sets it to true, but is deprecated. 6120 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 6121 } else if (ResType->isRealType()) { 6122 // OK! 6123 } else if (ResType->isAnyPointerType()) { 6124 QualType PointeeTy = ResType->getPointeeType(); 6125 6126 // C99 6.5.2.4p2, 6.5.6p2 6127 if (PointeeTy->isVoidType()) { 6128 if (getLangOptions().CPlusPlus) { 6129 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 6130 << Op->getSourceRange(); 6131 return QualType(); 6132 } 6133 6134 // Pointer to void is a GNU extension in C. 6135 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 6136 } else if (PointeeTy->isFunctionType()) { 6137 if (getLangOptions().CPlusPlus) { 6138 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 6139 << Op->getType() << Op->getSourceRange(); 6140 return QualType(); 6141 } 6142 6143 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 6144 << ResType << Op->getSourceRange(); 6145 } else if (RequireCompleteType(OpLoc, PointeeTy, 6146 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6147 << Op->getSourceRange() 6148 << ResType)) 6149 return QualType(); 6150 // Diagnose bad cases where we step over interface counts. 6151 else if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6152 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6153 << PointeeTy << Op->getSourceRange(); 6154 return QualType(); 6155 } 6156 } else if (ResType->isAnyComplexType()) { 6157 // C99 does not support ++/-- on complex types, we allow as an extension. 6158 Diag(OpLoc, diag::ext_integer_increment_complex) 6159 << ResType << Op->getSourceRange(); 6160 } else { 6161 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6162 << ResType << int(isInc) << Op->getSourceRange(); 6163 return QualType(); 6164 } 6165 // At this point, we know we have a real, complex or pointer type. 6166 // Now make sure the operand is a modifiable lvalue. 6167 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6168 return QualType(); 6169 // In C++, a prefix increment is the same type as the operand. Otherwise 6170 // (in C or with postfix), the increment is the unqualified type of the 6171 // operand. 6172 return isPrefix && getLangOptions().CPlusPlus 6173 ? ResType : ResType.getUnqualifiedType(); 6174} 6175 6176/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6177/// This routine allows us to typecheck complex/recursive expressions 6178/// where the declaration is needed for type checking. We only need to 6179/// handle cases when the expression references a function designator 6180/// or is an lvalue. Here are some examples: 6181/// - &(x) => x 6182/// - &*****f => f for f a function designator. 6183/// - &s.xx => s 6184/// - &s.zz[1].yy -> s, if zz is an array 6185/// - *(x + 1) -> x, if x is an array 6186/// - &"123"[2] -> 0 6187/// - & __real__ x -> x 6188static NamedDecl *getPrimaryDecl(Expr *E) { 6189 switch (E->getStmtClass()) { 6190 case Stmt::DeclRefExprClass: 6191 return cast<DeclRefExpr>(E)->getDecl(); 6192 case Stmt::MemberExprClass: 6193 // If this is an arrow operator, the address is an offset from 6194 // the base's value, so the object the base refers to is 6195 // irrelevant. 6196 if (cast<MemberExpr>(E)->isArrow()) 6197 return 0; 6198 // Otherwise, the expression refers to a part of the base 6199 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6200 case Stmt::ArraySubscriptExprClass: { 6201 // FIXME: This code shouldn't be necessary! We should catch the implicit 6202 // promotion of register arrays earlier. 6203 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6204 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6205 if (ICE->getSubExpr()->getType()->isArrayType()) 6206 return getPrimaryDecl(ICE->getSubExpr()); 6207 } 6208 return 0; 6209 } 6210 case Stmt::UnaryOperatorClass: { 6211 UnaryOperator *UO = cast<UnaryOperator>(E); 6212 6213 switch(UO->getOpcode()) { 6214 case UO_Real: 6215 case UO_Imag: 6216 case UO_Extension: 6217 return getPrimaryDecl(UO->getSubExpr()); 6218 default: 6219 return 0; 6220 } 6221 } 6222 case Stmt::ParenExprClass: 6223 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6224 case Stmt::ImplicitCastExprClass: 6225 // If the result of an implicit cast is an l-value, we care about 6226 // the sub-expression; otherwise, the result here doesn't matter. 6227 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6228 default: 6229 return 0; 6230 } 6231} 6232 6233/// CheckAddressOfOperand - The operand of & must be either a function 6234/// designator or an lvalue designating an object. If it is an lvalue, the 6235/// object cannot be declared with storage class register or be a bit field. 6236/// Note: The usual conversions are *not* applied to the operand of the & 6237/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6238/// In C++, the operand might be an overloaded function name, in which case 6239/// we allow the '&' but retain the overloaded-function type. 6240QualType Sema::CheckAddressOfOperand(Expr *OrigOp, SourceLocation OpLoc) { 6241 if (OrigOp->isTypeDependent()) 6242 return Context.DependentTy; 6243 if (OrigOp->getType() == Context.OverloadTy) 6244 return Context.OverloadTy; 6245 6246 // Make sure to ignore parentheses in subsequent checks 6247 Expr *op = OrigOp->IgnoreParens(); 6248 6249 if (getLangOptions().C99) { 6250 // Implement C99-only parts of addressof rules. 6251 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6252 if (uOp->getOpcode() == UO_Deref) 6253 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6254 // (assuming the deref expression is valid). 6255 return uOp->getSubExpr()->getType(); 6256 } 6257 // Technically, there should be a check for array subscript 6258 // expressions here, but the result of one is always an lvalue anyway. 6259 } 6260 NamedDecl *dcl = getPrimaryDecl(op); 6261 Expr::isLvalueResult lval = op->isLvalue(Context); 6262 6263 if (lval == Expr::LV_ClassTemporary) { 6264 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6265 : diag::ext_typecheck_addrof_class_temporary) 6266 << op->getType() << op->getSourceRange(); 6267 if (isSFINAEContext()) 6268 return QualType(); 6269 } else if (isa<ObjCSelectorExpr>(op)) { 6270 return Context.getPointerType(op->getType()); 6271 } else if (lval == Expr::LV_MemberFunction) { 6272 // If it's an instance method, make a member pointer. 6273 // The expression must have exactly the form &A::foo. 6274 6275 // If the underlying expression isn't a decl ref, give up. 6276 if (!isa<DeclRefExpr>(op)) { 6277 Diag(OpLoc, diag::err_invalid_form_pointer_member_function) 6278 << OrigOp->getSourceRange(); 6279 return QualType(); 6280 } 6281 DeclRefExpr *DRE = cast<DeclRefExpr>(op); 6282 CXXMethodDecl *MD = cast<CXXMethodDecl>(DRE->getDecl()); 6283 6284 // The id-expression was parenthesized. 6285 if (OrigOp != DRE) { 6286 Diag(OpLoc, diag::err_parens_pointer_member_function) 6287 << OrigOp->getSourceRange(); 6288 6289 // The method was named without a qualifier. 6290 } else if (!DRE->getQualifier()) { 6291 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6292 << op->getSourceRange(); 6293 } 6294 6295 return Context.getMemberPointerType(op->getType(), 6296 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6297 } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6298 // C99 6.5.3.2p1 6299 // The operand must be either an l-value or a function designator 6300 if (!op->getType()->isFunctionType()) { 6301 // FIXME: emit more specific diag... 6302 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6303 << op->getSourceRange(); 6304 return QualType(); 6305 } 6306 } else if (op->getBitField()) { // C99 6.5.3.2p1 6307 // The operand cannot be a bit-field 6308 Diag(OpLoc, diag::err_typecheck_address_of) 6309 << "bit-field" << op->getSourceRange(); 6310 return QualType(); 6311 } else if (op->refersToVectorElement()) { 6312 // The operand cannot be an element of a vector 6313 Diag(OpLoc, diag::err_typecheck_address_of) 6314 << "vector element" << op->getSourceRange(); 6315 return QualType(); 6316 } else if (isa<ObjCPropertyRefExpr>(op)) { 6317 // cannot take address of a property expression. 6318 Diag(OpLoc, diag::err_typecheck_address_of) 6319 << "property expression" << op->getSourceRange(); 6320 return QualType(); 6321 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6322 // FIXME: Can LHS ever be null here? 6323 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6324 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6325 } else if (dcl) { // C99 6.5.3.2p1 6326 // We have an lvalue with a decl. Make sure the decl is not declared 6327 // with the register storage-class specifier. 6328 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6329 // in C++ it is not error to take address of a register 6330 // variable (c++03 7.1.1P3) 6331 if (vd->getStorageClass() == SC_Register && 6332 !getLangOptions().CPlusPlus) { 6333 Diag(OpLoc, diag::err_typecheck_address_of) 6334 << "register variable" << op->getSourceRange(); 6335 return QualType(); 6336 } 6337 } else if (isa<FunctionTemplateDecl>(dcl)) { 6338 return Context.OverloadTy; 6339 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6340 // Okay: we can take the address of a field. 6341 // Could be a pointer to member, though, if there is an explicit 6342 // scope qualifier for the class. 6343 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6344 DeclContext *Ctx = dcl->getDeclContext(); 6345 if (Ctx && Ctx->isRecord()) { 6346 if (FD->getType()->isReferenceType()) { 6347 Diag(OpLoc, 6348 diag::err_cannot_form_pointer_to_member_of_reference_type) 6349 << FD->getDeclName() << FD->getType(); 6350 return QualType(); 6351 } 6352 6353 return Context.getMemberPointerType(op->getType(), 6354 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6355 } 6356 } 6357 } else if (!isa<FunctionDecl>(dcl)) 6358 assert(0 && "Unknown/unexpected decl type"); 6359 } 6360 6361 if (lval == Expr::LV_IncompleteVoidType) { 6362 // Taking the address of a void variable is technically illegal, but we 6363 // allow it in cases which are otherwise valid. 6364 // Example: "extern void x; void* y = &x;". 6365 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6366 } 6367 6368 // If the operand has type "type", the result has type "pointer to type". 6369 if (op->getType()->isObjCObjectType()) 6370 return Context.getObjCObjectPointerType(op->getType()); 6371 return Context.getPointerType(op->getType()); 6372} 6373 6374/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 6375QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6376 if (Op->isTypeDependent()) 6377 return Context.DependentTy; 6378 6379 UsualUnaryConversions(Op); 6380 QualType OpTy = Op->getType(); 6381 QualType Result; 6382 6383 // Note that per both C89 and C99, indirection is always legal, even if OpTy 6384 // is an incomplete type or void. It would be possible to warn about 6385 // dereferencing a void pointer, but it's completely well-defined, and such a 6386 // warning is unlikely to catch any mistakes. 6387 if (const PointerType *PT = OpTy->getAs<PointerType>()) 6388 Result = PT->getPointeeType(); 6389 else if (const ObjCObjectPointerType *OPT = 6390 OpTy->getAs<ObjCObjectPointerType>()) 6391 Result = OPT->getPointeeType(); 6392 6393 if (Result.isNull()) { 6394 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6395 << OpTy << Op->getSourceRange(); 6396 return QualType(); 6397 } 6398 6399 return Result; 6400} 6401 6402static inline BinaryOperatorKind ConvertTokenKindToBinaryOpcode( 6403 tok::TokenKind Kind) { 6404 BinaryOperatorKind Opc; 6405 switch (Kind) { 6406 default: assert(0 && "Unknown binop!"); 6407 case tok::periodstar: Opc = BO_PtrMemD; break; 6408 case tok::arrowstar: Opc = BO_PtrMemI; break; 6409 case tok::star: Opc = BO_Mul; break; 6410 case tok::slash: Opc = BO_Div; break; 6411 case tok::percent: Opc = BO_Rem; break; 6412 case tok::plus: Opc = BO_Add; break; 6413 case tok::minus: Opc = BO_Sub; break; 6414 case tok::lessless: Opc = BO_Shl; break; 6415 case tok::greatergreater: Opc = BO_Shr; break; 6416 case tok::lessequal: Opc = BO_LE; break; 6417 case tok::less: Opc = BO_LT; break; 6418 case tok::greaterequal: Opc = BO_GE; break; 6419 case tok::greater: Opc = BO_GT; break; 6420 case tok::exclaimequal: Opc = BO_NE; break; 6421 case tok::equalequal: Opc = BO_EQ; break; 6422 case tok::amp: Opc = BO_And; break; 6423 case tok::caret: Opc = BO_Xor; break; 6424 case tok::pipe: Opc = BO_Or; break; 6425 case tok::ampamp: Opc = BO_LAnd; break; 6426 case tok::pipepipe: Opc = BO_LOr; break; 6427 case tok::equal: Opc = BO_Assign; break; 6428 case tok::starequal: Opc = BO_MulAssign; break; 6429 case tok::slashequal: Opc = BO_DivAssign; break; 6430 case tok::percentequal: Opc = BO_RemAssign; break; 6431 case tok::plusequal: Opc = BO_AddAssign; break; 6432 case tok::minusequal: Opc = BO_SubAssign; break; 6433 case tok::lesslessequal: Opc = BO_ShlAssign; break; 6434 case tok::greatergreaterequal: Opc = BO_ShrAssign; break; 6435 case tok::ampequal: Opc = BO_AndAssign; break; 6436 case tok::caretequal: Opc = BO_XorAssign; break; 6437 case tok::pipeequal: Opc = BO_OrAssign; break; 6438 case tok::comma: Opc = BO_Comma; break; 6439 } 6440 return Opc; 6441} 6442 6443static inline UnaryOperatorKind ConvertTokenKindToUnaryOpcode( 6444 tok::TokenKind Kind) { 6445 UnaryOperatorKind Opc; 6446 switch (Kind) { 6447 default: assert(0 && "Unknown unary op!"); 6448 case tok::plusplus: Opc = UO_PreInc; break; 6449 case tok::minusminus: Opc = UO_PreDec; break; 6450 case tok::amp: Opc = UO_AddrOf; break; 6451 case tok::star: Opc = UO_Deref; break; 6452 case tok::plus: Opc = UO_Plus; break; 6453 case tok::minus: Opc = UO_Minus; break; 6454 case tok::tilde: Opc = UO_Not; break; 6455 case tok::exclaim: Opc = UO_LNot; break; 6456 case tok::kw___real: Opc = UO_Real; break; 6457 case tok::kw___imag: Opc = UO_Imag; break; 6458 case tok::kw___extension__: Opc = UO_Extension; break; 6459 } 6460 return Opc; 6461} 6462 6463/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6464/// operator @p Opc at location @c TokLoc. This routine only supports 6465/// built-in operations; ActOnBinOp handles overloaded operators. 6466ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6467 unsigned Op, 6468 Expr *lhs, Expr *rhs) { 6469 QualType ResultTy; // Result type of the binary operator. 6470 BinaryOperatorKind Opc = (BinaryOperatorKind) Op; 6471 // The following two variables are used for compound assignment operators 6472 QualType CompLHSTy; // Type of LHS after promotions for computation 6473 QualType CompResultTy; // Type of computation result 6474 6475 switch (Opc) { 6476 case BO_Assign: 6477 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6478 break; 6479 case BO_PtrMemD: 6480 case BO_PtrMemI: 6481 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6482 Opc == BO_PtrMemI); 6483 break; 6484 case BO_Mul: 6485 case BO_Div: 6486 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6487 Opc == BO_Div); 6488 break; 6489 case BO_Rem: 6490 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6491 break; 6492 case BO_Add: 6493 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6494 break; 6495 case BO_Sub: 6496 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6497 break; 6498 case BO_Shl: 6499 case BO_Shr: 6500 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6501 break; 6502 case BO_LE: 6503 case BO_LT: 6504 case BO_GE: 6505 case BO_GT: 6506 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6507 break; 6508 case BO_EQ: 6509 case BO_NE: 6510 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6511 break; 6512 case BO_And: 6513 case BO_Xor: 6514 case BO_Or: 6515 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6516 break; 6517 case BO_LAnd: 6518 case BO_LOr: 6519 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 6520 break; 6521 case BO_MulAssign: 6522 case BO_DivAssign: 6523 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6524 Opc == BO_DivAssign); 6525 CompLHSTy = CompResultTy; 6526 if (!CompResultTy.isNull()) 6527 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6528 break; 6529 case BO_RemAssign: 6530 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6531 CompLHSTy = CompResultTy; 6532 if (!CompResultTy.isNull()) 6533 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6534 break; 6535 case BO_AddAssign: 6536 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6537 if (!CompResultTy.isNull()) 6538 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6539 break; 6540 case BO_SubAssign: 6541 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6542 if (!CompResultTy.isNull()) 6543 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6544 break; 6545 case BO_ShlAssign: 6546 case BO_ShrAssign: 6547 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6548 CompLHSTy = CompResultTy; 6549 if (!CompResultTy.isNull()) 6550 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6551 break; 6552 case BO_AndAssign: 6553 case BO_XorAssign: 6554 case BO_OrAssign: 6555 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6556 CompLHSTy = CompResultTy; 6557 if (!CompResultTy.isNull()) 6558 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6559 break; 6560 case BO_Comma: 6561 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6562 break; 6563 } 6564 if (ResultTy.isNull()) 6565 return ExprError(); 6566 if (ResultTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6567 if (Opc >= BO_Assign && Opc <= BO_OrAssign) 6568 Diag(OpLoc, diag::err_assignment_requires_nonfragile_object) 6569 << ResultTy; 6570 } 6571 if (CompResultTy.isNull()) 6572 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6573 else 6574 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6575 CompLHSTy, CompResultTy, 6576 OpLoc)); 6577} 6578 6579/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6580/// ParenRange in parentheses. 6581static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6582 const PartialDiagnostic &PD, 6583 const PartialDiagnostic &FirstNote, 6584 SourceRange FirstParenRange, 6585 const PartialDiagnostic &SecondNote, 6586 SourceRange SecondParenRange) { 6587 Self.Diag(Loc, PD); 6588 6589 if (!FirstNote.getDiagID()) 6590 return; 6591 6592 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 6593 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6594 // We can't display the parentheses, so just return. 6595 return; 6596 } 6597 6598 Self.Diag(Loc, FirstNote) 6599 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 6600 << FixItHint::CreateInsertion(EndLoc, ")"); 6601 6602 if (!SecondNote.getDiagID()) 6603 return; 6604 6605 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6606 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6607 // We can't display the parentheses, so just dig the 6608 // warning/error and return. 6609 Self.Diag(Loc, SecondNote); 6610 return; 6611 } 6612 6613 Self.Diag(Loc, SecondNote) 6614 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6615 << FixItHint::CreateInsertion(EndLoc, ")"); 6616} 6617 6618/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6619/// operators are mixed in a way that suggests that the programmer forgot that 6620/// comparison operators have higher precedence. The most typical example of 6621/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6622static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperatorKind Opc, 6623 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6624 typedef BinaryOperator BinOp; 6625 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6626 rhsopc = static_cast<BinOp::Opcode>(-1); 6627 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6628 lhsopc = BO->getOpcode(); 6629 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6630 rhsopc = BO->getOpcode(); 6631 6632 // Subs are not binary operators. 6633 if (lhsopc == -1 && rhsopc == -1) 6634 return; 6635 6636 // Bitwise operations are sometimes used as eager logical ops. 6637 // Don't diagnose this. 6638 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6639 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6640 return; 6641 6642 if (BinOp::isComparisonOp(lhsopc)) 6643 SuggestParentheses(Self, OpLoc, 6644 Self.PDiag(diag::warn_precedence_bitwise_rel) 6645 << SourceRange(lhs->getLocStart(), OpLoc) 6646 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6647 Self.PDiag(diag::note_precedence_bitwise_first) 6648 << BinOp::getOpcodeStr(Opc), 6649 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 6650 Self.PDiag(diag::note_precedence_bitwise_silence) 6651 << BinOp::getOpcodeStr(lhsopc), 6652 lhs->getSourceRange()); 6653 else if (BinOp::isComparisonOp(rhsopc)) 6654 SuggestParentheses(Self, OpLoc, 6655 Self.PDiag(diag::warn_precedence_bitwise_rel) 6656 << SourceRange(OpLoc, rhs->getLocEnd()) 6657 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6658 Self.PDiag(diag::note_precedence_bitwise_first) 6659 << BinOp::getOpcodeStr(Opc), 6660 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 6661 Self.PDiag(diag::note_precedence_bitwise_silence) 6662 << BinOp::getOpcodeStr(rhsopc), 6663 rhs->getSourceRange()); 6664} 6665 6666/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6667/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6668/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6669static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, 6670 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6671 if (BinaryOperator::isBitwiseOp(Opc)) 6672 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6673} 6674 6675// Binary Operators. 'Tok' is the token for the operator. 6676ExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6677 tok::TokenKind Kind, 6678 Expr *lhs, Expr *rhs) { 6679 BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Kind); 6680 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6681 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6682 6683 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6684 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6685 6686 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6687} 6688 6689ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6690 BinaryOperatorKind Opc, 6691 Expr *lhs, Expr *rhs) { 6692 if (getLangOptions().CPlusPlus && 6693 (lhs->getType()->isOverloadableType() || 6694 rhs->getType()->isOverloadableType())) { 6695 // Find all of the overloaded operators visible from this 6696 // point. We perform both an operator-name lookup from the local 6697 // scope and an argument-dependent lookup based on the types of 6698 // the arguments. 6699 UnresolvedSet<16> Functions; 6700 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6701 if (S && OverOp != OO_None) 6702 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6703 Functions); 6704 6705 // Build the (potentially-overloaded, potentially-dependent) 6706 // binary operation. 6707 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6708 } 6709 6710 // Build a built-in binary operation. 6711 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6712} 6713 6714ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6715 unsigned OpcIn, 6716 Expr *Input) { 6717 UnaryOperatorKind Opc = static_cast<UnaryOperatorKind>(OpcIn); 6718 6719 QualType resultType; 6720 switch (Opc) { 6721 case UO_PreInc: 6722 case UO_PreDec: 6723 case UO_PostInc: 6724 case UO_PostDec: 6725 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6726 Opc == UO_PreInc || 6727 Opc == UO_PostInc, 6728 Opc == UO_PreInc || 6729 Opc == UO_PreDec); 6730 break; 6731 case UO_AddrOf: 6732 resultType = CheckAddressOfOperand(Input, OpLoc); 6733 break; 6734 case UO_Deref: 6735 DefaultFunctionArrayLvalueConversion(Input); 6736 resultType = CheckIndirectionOperand(Input, OpLoc); 6737 break; 6738 case UO_Plus: 6739 case UO_Minus: 6740 UsualUnaryConversions(Input); 6741 resultType = Input->getType(); 6742 if (resultType->isDependentType()) 6743 break; 6744 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 6745 resultType->isVectorType()) 6746 break; 6747 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6748 resultType->isEnumeralType()) 6749 break; 6750 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6751 Opc == UO_Plus && 6752 resultType->isPointerType()) 6753 break; 6754 6755 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6756 << resultType << Input->getSourceRange()); 6757 case UO_Not: // bitwise complement 6758 UsualUnaryConversions(Input); 6759 resultType = Input->getType(); 6760 if (resultType->isDependentType()) 6761 break; 6762 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6763 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6764 // C99 does not support '~' for complex conjugation. 6765 Diag(OpLoc, diag::ext_integer_complement_complex) 6766 << resultType << Input->getSourceRange(); 6767 else if (!resultType->hasIntegerRepresentation()) 6768 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6769 << resultType << Input->getSourceRange()); 6770 break; 6771 case UO_LNot: // logical negation 6772 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6773 DefaultFunctionArrayLvalueConversion(Input); 6774 resultType = Input->getType(); 6775 if (resultType->isDependentType()) 6776 break; 6777 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6778 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6779 << resultType << Input->getSourceRange()); 6780 // LNot always has type int. C99 6.5.3.3p5. 6781 // In C++, it's bool. C++ 5.3.1p8 6782 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6783 break; 6784 case UO_Real: 6785 case UO_Imag: 6786 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UO_Real); 6787 break; 6788 case UO_Extension: 6789 resultType = Input->getType(); 6790 break; 6791 } 6792 if (resultType.isNull()) 6793 return ExprError(); 6794 6795 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6796} 6797 6798ExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6799 UnaryOperatorKind Opc, 6800 Expr *Input) { 6801 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6802 Opc != UO_Extension) { 6803 // Find all of the overloaded operators visible from this 6804 // point. We perform both an operator-name lookup from the local 6805 // scope and an argument-dependent lookup based on the types of 6806 // the arguments. 6807 UnresolvedSet<16> Functions; 6808 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6809 if (S && OverOp != OO_None) 6810 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6811 Functions); 6812 6813 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); 6814 } 6815 6816 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6817} 6818 6819// Unary Operators. 'Tok' is the token for the operator. 6820ExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6821 tok::TokenKind Op, Expr *Input) { 6822 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); 6823} 6824 6825/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6826ExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6827 SourceLocation LabLoc, 6828 IdentifierInfo *LabelII) { 6829 // Look up the record for this label identifier. 6830 LabelStmt *&LabelDecl = getCurFunction()->LabelMap[LabelII]; 6831 6832 // If we haven't seen this label yet, create a forward reference. It 6833 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6834 if (LabelDecl == 0) 6835 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6836 6837 // Create the AST node. The address of a label always has type 'void*'. 6838 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6839 Context.getPointerType(Context.VoidTy))); 6840} 6841 6842ExprResult 6843Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, 6844 SourceLocation RPLoc) { // "({..})" 6845 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6846 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6847 6848 bool isFileScope 6849 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6850 if (isFileScope) 6851 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6852 6853 // FIXME: there are a variety of strange constraints to enforce here, for 6854 // example, it is not possible to goto into a stmt expression apparently. 6855 // More semantic analysis is needed. 6856 6857 // If there are sub stmts in the compound stmt, take the type of the last one 6858 // as the type of the stmtexpr. 6859 QualType Ty = Context.VoidTy; 6860 6861 if (!Compound->body_empty()) { 6862 Stmt *LastStmt = Compound->body_back(); 6863 // If LastStmt is a label, skip down through into the body. 6864 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6865 LastStmt = Label->getSubStmt(); 6866 6867 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6868 Ty = LastExpr->getType(); 6869 } 6870 6871 // FIXME: Check that expression type is complete/non-abstract; statement 6872 // expressions are not lvalues. 6873 6874 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6875} 6876 6877ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 6878 TypeSourceInfo *TInfo, 6879 OffsetOfComponent *CompPtr, 6880 unsigned NumComponents, 6881 SourceLocation RParenLoc) { 6882 QualType ArgTy = TInfo->getType(); 6883 bool Dependent = ArgTy->isDependentType(); 6884 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 6885 6886 // We must have at least one component that refers to the type, and the first 6887 // one is known to be a field designator. Verify that the ArgTy represents 6888 // a struct/union/class. 6889 if (!Dependent && !ArgTy->isRecordType()) 6890 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 6891 << ArgTy << TypeRange); 6892 6893 // Type must be complete per C99 7.17p3 because a declaring a variable 6894 // with an incomplete type would be ill-formed. 6895 if (!Dependent 6896 && RequireCompleteType(BuiltinLoc, ArgTy, 6897 PDiag(diag::err_offsetof_incomplete_type) 6898 << TypeRange)) 6899 return ExprError(); 6900 6901 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6902 // GCC extension, diagnose them. 6903 // FIXME: This diagnostic isn't actually visible because the location is in 6904 // a system header! 6905 if (NumComponents != 1) 6906 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6907 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6908 6909 bool DidWarnAboutNonPOD = false; 6910 QualType CurrentType = ArgTy; 6911 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 6912 llvm::SmallVector<OffsetOfNode, 4> Comps; 6913 llvm::SmallVector<Expr*, 4> Exprs; 6914 for (unsigned i = 0; i != NumComponents; ++i) { 6915 const OffsetOfComponent &OC = CompPtr[i]; 6916 if (OC.isBrackets) { 6917 // Offset of an array sub-field. TODO: Should we allow vector elements? 6918 if (!CurrentType->isDependentType()) { 6919 const ArrayType *AT = Context.getAsArrayType(CurrentType); 6920 if(!AT) 6921 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6922 << CurrentType); 6923 CurrentType = AT->getElementType(); 6924 } else 6925 CurrentType = Context.DependentTy; 6926 6927 // The expression must be an integral expression. 6928 // FIXME: An integral constant expression? 6929 Expr *Idx = static_cast<Expr*>(OC.U.E); 6930 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 6931 !Idx->getType()->isIntegerType()) 6932 return ExprError(Diag(Idx->getLocStart(), 6933 diag::err_typecheck_subscript_not_integer) 6934 << Idx->getSourceRange()); 6935 6936 // Record this array index. 6937 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 6938 Exprs.push_back(Idx); 6939 continue; 6940 } 6941 6942 // Offset of a field. 6943 if (CurrentType->isDependentType()) { 6944 // We have the offset of a field, but we can't look into the dependent 6945 // type. Just record the identifier of the field. 6946 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 6947 CurrentType = Context.DependentTy; 6948 continue; 6949 } 6950 6951 // We need to have a complete type to look into. 6952 if (RequireCompleteType(OC.LocStart, CurrentType, 6953 diag::err_offsetof_incomplete_type)) 6954 return ExprError(); 6955 6956 // Look for the designated field. 6957 const RecordType *RC = CurrentType->getAs<RecordType>(); 6958 if (!RC) 6959 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6960 << CurrentType); 6961 RecordDecl *RD = RC->getDecl(); 6962 6963 // C++ [lib.support.types]p5: 6964 // The macro offsetof accepts a restricted set of type arguments in this 6965 // International Standard. type shall be a POD structure or a POD union 6966 // (clause 9). 6967 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6968 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6969 DiagRuntimeBehavior(BuiltinLoc, 6970 PDiag(diag::warn_offsetof_non_pod_type) 6971 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6972 << CurrentType)) 6973 DidWarnAboutNonPOD = true; 6974 } 6975 6976 // Look for the field. 6977 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6978 LookupQualifiedName(R, RD); 6979 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6980 if (!MemberDecl) 6981 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6982 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 6983 OC.LocEnd)); 6984 6985 // C99 7.17p3: 6986 // (If the specified member is a bit-field, the behavior is undefined.) 6987 // 6988 // We diagnose this as an error. 6989 if (MemberDecl->getBitWidth()) { 6990 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 6991 << MemberDecl->getDeclName() 6992 << SourceRange(BuiltinLoc, RParenLoc); 6993 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 6994 return ExprError(); 6995 } 6996 6997 RecordDecl *Parent = MemberDecl->getParent(); 6998 bool AnonStructUnion = Parent->isAnonymousStructOrUnion(); 6999 if (AnonStructUnion) { 7000 do { 7001 Parent = cast<RecordDecl>(Parent->getParent()); 7002 } while (Parent->isAnonymousStructOrUnion()); 7003 } 7004 7005 // If the member was found in a base class, introduce OffsetOfNodes for 7006 // the base class indirections. 7007 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 7008 /*DetectVirtual=*/false); 7009 if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { 7010 CXXBasePath &Path = Paths.front(); 7011 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 7012 B != BEnd; ++B) 7013 Comps.push_back(OffsetOfNode(B->Base)); 7014 } 7015 7016 if (AnonStructUnion) { 7017 llvm::SmallVector<FieldDecl*, 4> Path; 7018 BuildAnonymousStructUnionMemberPath(MemberDecl, Path); 7019 unsigned n = Path.size(); 7020 for (int j = n - 1; j > -1; --j) 7021 Comps.push_back(OffsetOfNode(OC.LocStart, Path[j], OC.LocEnd)); 7022 } else { 7023 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 7024 } 7025 CurrentType = MemberDecl->getType().getNonReferenceType(); 7026 } 7027 7028 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 7029 TInfo, Comps.data(), Comps.size(), 7030 Exprs.data(), Exprs.size(), RParenLoc)); 7031} 7032 7033ExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 7034 SourceLocation BuiltinLoc, 7035 SourceLocation TypeLoc, 7036 ParsedType argty, 7037 OffsetOfComponent *CompPtr, 7038 unsigned NumComponents, 7039 SourceLocation RPLoc) { 7040 7041 TypeSourceInfo *ArgTInfo; 7042 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 7043 if (ArgTy.isNull()) 7044 return ExprError(); 7045 7046 if (!ArgTInfo) 7047 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 7048 7049 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 7050 RPLoc); 7051} 7052 7053 7054ExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 7055 ParsedType arg1,ParsedType arg2, 7056 SourceLocation RPLoc) { 7057 TypeSourceInfo *argTInfo1; 7058 QualType argT1 = GetTypeFromParser(arg1, &argTInfo1); 7059 TypeSourceInfo *argTInfo2; 7060 QualType argT2 = GetTypeFromParser(arg2, &argTInfo2); 7061 7062 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 7063 7064 return BuildTypesCompatibleExpr(BuiltinLoc, argTInfo1, argTInfo2, RPLoc); 7065} 7066 7067ExprResult 7068Sema::BuildTypesCompatibleExpr(SourceLocation BuiltinLoc, 7069 TypeSourceInfo *argTInfo1, 7070 TypeSourceInfo *argTInfo2, 7071 SourceLocation RPLoc) { 7072 if (getLangOptions().CPlusPlus) { 7073 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 7074 << SourceRange(BuiltinLoc, RPLoc); 7075 return ExprError(); 7076 } 7077 7078 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 7079 argTInfo1, argTInfo2, RPLoc)); 7080} 7081 7082 7083ExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 7084 Expr *CondExpr, 7085 Expr *LHSExpr, Expr *RHSExpr, 7086 SourceLocation RPLoc) { 7087 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 7088 7089 QualType resType; 7090 bool ValueDependent = false; 7091 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 7092 resType = Context.DependentTy; 7093 ValueDependent = true; 7094 } else { 7095 // The conditional expression is required to be a constant expression. 7096 llvm::APSInt condEval(32); 7097 SourceLocation ExpLoc; 7098 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 7099 return ExprError(Diag(ExpLoc, 7100 diag::err_typecheck_choose_expr_requires_constant) 7101 << CondExpr->getSourceRange()); 7102 7103 // If the condition is > zero, then the AST type is the same as the LSHExpr. 7104 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 7105 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 7106 : RHSExpr->isValueDependent(); 7107 } 7108 7109 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 7110 resType, RPLoc, 7111 resType->isDependentType(), 7112 ValueDependent)); 7113} 7114 7115//===----------------------------------------------------------------------===// 7116// Clang Extensions. 7117//===----------------------------------------------------------------------===// 7118 7119/// ActOnBlockStart - This callback is invoked when a block literal is started. 7120void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 7121 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 7122 PushBlockScope(BlockScope, Block); 7123 CurContext->addDecl(Block); 7124 if (BlockScope) 7125 PushDeclContext(BlockScope, Block); 7126 else 7127 CurContext = Block; 7128} 7129 7130void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 7131 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 7132 BlockScopeInfo *CurBlock = getCurBlock(); 7133 7134 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 7135 CurBlock->TheDecl->setSignatureAsWritten(Sig); 7136 QualType T = Sig->getType(); 7137 7138 bool isVariadic; 7139 QualType RetTy; 7140 if (const FunctionType *Fn = T->getAs<FunctionType>()) { 7141 CurBlock->FunctionType = T; 7142 RetTy = Fn->getResultType(); 7143 isVariadic = 7144 !isa<FunctionProtoType>(Fn) || cast<FunctionProtoType>(Fn)->isVariadic(); 7145 } else { 7146 RetTy = T; 7147 isVariadic = false; 7148 } 7149 7150 CurBlock->TheDecl->setIsVariadic(isVariadic); 7151 7152 // Don't allow returning an array by value. 7153 if (RetTy->isArrayType()) { 7154 Diag(ParamInfo.getSourceRange().getBegin(), diag::err_block_returns_array); 7155 return; 7156 } 7157 7158 // Don't allow returning a objc interface by value. 7159 if (RetTy->isObjCObjectType()) { 7160 Diag(ParamInfo.getSourceRange().getBegin(), 7161 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7162 return; 7163 } 7164 7165 // Context.DependentTy is used as a placeholder for a missing block 7166 // return type. TODO: what should we do with declarators like: 7167 // ^ * { ... } 7168 // If the answer is "apply template argument deduction".... 7169 if (RetTy != Context.DependentTy) 7170 CurBlock->ReturnType = RetTy; 7171 7172 // Push block parameters from the declarator if we had them. 7173 llvm::SmallVector<ParmVarDecl*, 8> Params; 7174 if (isa<FunctionProtoType>(T)) { 7175 FunctionProtoTypeLoc TL = cast<FunctionProtoTypeLoc>(Sig->getTypeLoc()); 7176 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 7177 ParmVarDecl *Param = TL.getArg(I); 7178 if (Param->getIdentifier() == 0 && 7179 !Param->isImplicit() && 7180 !Param->isInvalidDecl() && 7181 !getLangOptions().CPlusPlus) 7182 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 7183 Params.push_back(Param); 7184 } 7185 7186 // Fake up parameter variables if we have a typedef, like 7187 // ^ fntype { ... } 7188 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 7189 for (FunctionProtoType::arg_type_iterator 7190 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 7191 ParmVarDecl *Param = 7192 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 7193 ParamInfo.getSourceRange().getBegin(), 7194 *I); 7195 Params.push_back(Param); 7196 } 7197 } 7198 7199 // Set the parameters on the block decl. 7200 if (!Params.empty()) 7201 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 7202 7203 // Finally we can process decl attributes. 7204 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 7205 7206 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 7207 Diag(ParamInfo.getAttributes()->getLoc(), 7208 diag::warn_attribute_sentinel_not_variadic) << 1; 7209 // FIXME: remove the attribute. 7210 } 7211 7212 // Put the parameter variables in scope. We can bail out immediately 7213 // if we don't have any. 7214 if (Params.empty()) 7215 return; 7216 7217 bool ShouldCheckShadow = 7218 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 7219 7220 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 7221 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 7222 (*AI)->setOwningFunction(CurBlock->TheDecl); 7223 7224 // If this has an identifier, add it to the scope stack. 7225 if ((*AI)->getIdentifier()) { 7226 if (ShouldCheckShadow) 7227 CheckShadow(CurBlock->TheScope, *AI); 7228 7229 PushOnScopeChains(*AI, CurBlock->TheScope); 7230 } 7231 } 7232} 7233 7234/// ActOnBlockError - If there is an error parsing a block, this callback 7235/// is invoked to pop the information about the block from the action impl. 7236void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7237 // Pop off CurBlock, handle nested blocks. 7238 PopDeclContext(); 7239 PopFunctionOrBlockScope(); 7240 // FIXME: Delete the ParmVarDecl objects as well??? 7241} 7242 7243/// ActOnBlockStmtExpr - This is called when the body of a block statement 7244/// literal was successfully completed. ^(int x){...} 7245ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7246 Stmt *Body, Scope *CurScope) { 7247 // If blocks are disabled, emit an error. 7248 if (!LangOpts.Blocks) 7249 Diag(CaretLoc, diag::err_blocks_disable); 7250 7251 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7252 7253 PopDeclContext(); 7254 7255 QualType RetTy = Context.VoidTy; 7256 if (!BSI->ReturnType.isNull()) 7257 RetTy = BSI->ReturnType; 7258 7259 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7260 QualType BlockTy; 7261 7262 // If the user wrote a function type in some form, try to use that. 7263 if (!BSI->FunctionType.isNull()) { 7264 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 7265 7266 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 7267 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 7268 7269 // Turn protoless block types into nullary block types. 7270 if (isa<FunctionNoProtoType>(FTy)) { 7271 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7272 false, false, 0, 0, Ext); 7273 7274 // Otherwise, if we don't need to change anything about the function type, 7275 // preserve its sugar structure. 7276 } else if (FTy->getResultType() == RetTy && 7277 (!NoReturn || FTy->getNoReturnAttr())) { 7278 BlockTy = BSI->FunctionType; 7279 7280 // Otherwise, make the minimal modifications to the function type. 7281 } else { 7282 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 7283 BlockTy = Context.getFunctionType(RetTy, 7284 FPT->arg_type_begin(), 7285 FPT->getNumArgs(), 7286 FPT->isVariadic(), 7287 /*quals*/ 0, 7288 FPT->hasExceptionSpec(), 7289 FPT->hasAnyExceptionSpec(), 7290 FPT->getNumExceptions(), 7291 FPT->exception_begin(), 7292 Ext); 7293 } 7294 7295 // If we don't have a function type, just build one from nothing. 7296 } else { 7297 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7298 false, false, 0, 0, 7299 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7300 } 7301 7302 // FIXME: Check that return/parameter types are complete/non-abstract 7303 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 7304 BSI->TheDecl->param_end()); 7305 BlockTy = Context.getBlockPointerType(BlockTy); 7306 7307 // If needed, diagnose invalid gotos and switches in the block. 7308 if (getCurFunction()->NeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7309 DiagnoseInvalidJumps(cast<CompoundStmt>(Body)); 7310 7311 BSI->TheDecl->setBody(cast<CompoundStmt>(Body)); 7312 7313 bool Good = true; 7314 // Check goto/label use. 7315 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7316 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7317 LabelStmt *L = I->second; 7318 7319 // Verify that we have no forward references left. If so, there was a goto 7320 // or address of a label taken, but no definition of it. 7321 if (L->getSubStmt() != 0) 7322 continue; 7323 7324 // Emit error. 7325 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7326 Good = false; 7327 } 7328 if (!Good) { 7329 PopFunctionOrBlockScope(); 7330 return ExprError(); 7331 } 7332 7333 BlockExpr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7334 BSI->hasBlockDeclRefExprs); 7335 7336 // Issue any analysis-based warnings. 7337 const sema::AnalysisBasedWarnings::Policy &WP = 7338 AnalysisWarnings.getDefaultPolicy(); 7339 AnalysisWarnings.IssueWarnings(WP, Result); 7340 7341 PopFunctionOrBlockScope(); 7342 return Owned(Result); 7343} 7344 7345ExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7346 Expr *expr, ParsedType type, 7347 SourceLocation RPLoc) { 7348 TypeSourceInfo *TInfo; 7349 QualType T = GetTypeFromParser(type, &TInfo); 7350 return BuildVAArgExpr(BuiltinLoc, expr, TInfo, RPLoc); 7351} 7352 7353ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, 7354 Expr *E, TypeSourceInfo *TInfo, 7355 SourceLocation RPLoc) { 7356 Expr *OrigExpr = E; 7357 7358 InitBuiltinVaListType(); 7359 7360 // Get the va_list type 7361 QualType VaListType = Context.getBuiltinVaListType(); 7362 if (VaListType->isArrayType()) { 7363 // Deal with implicit array decay; for example, on x86-64, 7364 // va_list is an array, but it's supposed to decay to 7365 // a pointer for va_arg. 7366 VaListType = Context.getArrayDecayedType(VaListType); 7367 // Make sure the input expression also decays appropriately. 7368 UsualUnaryConversions(E); 7369 } else { 7370 // Otherwise, the va_list argument must be an l-value because 7371 // it is modified by va_arg. 7372 if (!E->isTypeDependent() && 7373 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7374 return ExprError(); 7375 } 7376 7377 if (!E->isTypeDependent() && 7378 !Context.hasSameType(VaListType, E->getType())) { 7379 return ExprError(Diag(E->getLocStart(), 7380 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7381 << OrigExpr->getType() << E->getSourceRange()); 7382 } 7383 7384 // FIXME: Check that type is complete/non-abstract 7385 // FIXME: Warn if a non-POD type is passed in. 7386 7387 QualType T = TInfo->getType().getNonLValueExprType(Context); 7388 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T)); 7389} 7390 7391ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7392 // The type of __null will be int or long, depending on the size of 7393 // pointers on the target. 7394 QualType Ty; 7395 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7396 Ty = Context.IntTy; 7397 else 7398 Ty = Context.LongTy; 7399 7400 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7401} 7402 7403static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7404 Expr *SrcExpr, FixItHint &Hint) { 7405 if (!SemaRef.getLangOptions().ObjC1) 7406 return; 7407 7408 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7409 if (!PT) 7410 return; 7411 7412 // Check if the destination is of type 'id'. 7413 if (!PT->isObjCIdType()) { 7414 // Check if the destination is the 'NSString' interface. 7415 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7416 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7417 return; 7418 } 7419 7420 // Strip off any parens and casts. 7421 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7422 if (!SL || SL->isWide()) 7423 return; 7424 7425 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7426} 7427 7428bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7429 SourceLocation Loc, 7430 QualType DstType, QualType SrcType, 7431 Expr *SrcExpr, AssignmentAction Action, 7432 bool *Complained) { 7433 if (Complained) 7434 *Complained = false; 7435 7436 // Decode the result (notice that AST's are still created for extensions). 7437 bool isInvalid = false; 7438 unsigned DiagKind; 7439 FixItHint Hint; 7440 7441 switch (ConvTy) { 7442 default: assert(0 && "Unknown conversion type"); 7443 case Compatible: return false; 7444 case PointerToInt: 7445 DiagKind = diag::ext_typecheck_convert_pointer_int; 7446 break; 7447 case IntToPointer: 7448 DiagKind = diag::ext_typecheck_convert_int_pointer; 7449 break; 7450 case IncompatiblePointer: 7451 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7452 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7453 break; 7454 case IncompatiblePointerSign: 7455 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7456 break; 7457 case FunctionVoidPointer: 7458 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7459 break; 7460 case CompatiblePointerDiscardsQualifiers: 7461 // If the qualifiers lost were because we were applying the 7462 // (deprecated) C++ conversion from a string literal to a char* 7463 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7464 // Ideally, this check would be performed in 7465 // CheckPointerTypesForAssignment. However, that would require a 7466 // bit of refactoring (so that the second argument is an 7467 // expression, rather than a type), which should be done as part 7468 // of a larger effort to fix CheckPointerTypesForAssignment for 7469 // C++ semantics. 7470 if (getLangOptions().CPlusPlus && 7471 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7472 return false; 7473 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7474 break; 7475 case IncompatibleNestedPointerQualifiers: 7476 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7477 break; 7478 case IntToBlockPointer: 7479 DiagKind = diag::err_int_to_block_pointer; 7480 break; 7481 case IncompatibleBlockPointer: 7482 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7483 break; 7484 case IncompatibleObjCQualifiedId: 7485 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7486 // it can give a more specific diagnostic. 7487 DiagKind = diag::warn_incompatible_qualified_id; 7488 break; 7489 case IncompatibleVectors: 7490 DiagKind = diag::warn_incompatible_vectors; 7491 break; 7492 case Incompatible: 7493 DiagKind = diag::err_typecheck_convert_incompatible; 7494 isInvalid = true; 7495 break; 7496 } 7497 7498 QualType FirstType, SecondType; 7499 switch (Action) { 7500 case AA_Assigning: 7501 case AA_Initializing: 7502 // The destination type comes first. 7503 FirstType = DstType; 7504 SecondType = SrcType; 7505 break; 7506 7507 case AA_Returning: 7508 case AA_Passing: 7509 case AA_Converting: 7510 case AA_Sending: 7511 case AA_Casting: 7512 // The source type comes first. 7513 FirstType = SrcType; 7514 SecondType = DstType; 7515 break; 7516 } 7517 7518 Diag(Loc, DiagKind) << FirstType << SecondType << Action 7519 << SrcExpr->getSourceRange() << Hint; 7520 if (Complained) 7521 *Complained = true; 7522 return isInvalid; 7523} 7524 7525bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7526 llvm::APSInt ICEResult; 7527 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7528 if (Result) 7529 *Result = ICEResult; 7530 return false; 7531 } 7532 7533 Expr::EvalResult EvalResult; 7534 7535 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7536 EvalResult.HasSideEffects) { 7537 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7538 7539 if (EvalResult.Diag) { 7540 // We only show the note if it's not the usual "invalid subexpression" 7541 // or if it's actually in a subexpression. 7542 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7543 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7544 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7545 } 7546 7547 return true; 7548 } 7549 7550 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7551 E->getSourceRange(); 7552 7553 if (EvalResult.Diag && 7554 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7555 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7556 7557 if (Result) 7558 *Result = EvalResult.Val.getInt(); 7559 return false; 7560} 7561 7562void 7563Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7564 ExprEvalContexts.push_back( 7565 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7566} 7567 7568void 7569Sema::PopExpressionEvaluationContext() { 7570 // Pop the current expression evaluation context off the stack. 7571 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7572 ExprEvalContexts.pop_back(); 7573 7574 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7575 if (Rec.PotentiallyReferenced) { 7576 // Mark any remaining declarations in the current position of the stack 7577 // as "referenced". If they were not meant to be referenced, semantic 7578 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7579 for (PotentiallyReferencedDecls::iterator 7580 I = Rec.PotentiallyReferenced->begin(), 7581 IEnd = Rec.PotentiallyReferenced->end(); 7582 I != IEnd; ++I) 7583 MarkDeclarationReferenced(I->first, I->second); 7584 } 7585 7586 if (Rec.PotentiallyDiagnosed) { 7587 // Emit any pending diagnostics. 7588 for (PotentiallyEmittedDiagnostics::iterator 7589 I = Rec.PotentiallyDiagnosed->begin(), 7590 IEnd = Rec.PotentiallyDiagnosed->end(); 7591 I != IEnd; ++I) 7592 Diag(I->first, I->second); 7593 } 7594 } 7595 7596 // When are coming out of an unevaluated context, clear out any 7597 // temporaries that we may have created as part of the evaluation of 7598 // the expression in that context: they aren't relevant because they 7599 // will never be constructed. 7600 if (Rec.Context == Unevaluated && 7601 ExprTemporaries.size() > Rec.NumTemporaries) 7602 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7603 ExprTemporaries.end()); 7604 7605 // Destroy the popped expression evaluation record. 7606 Rec.Destroy(); 7607} 7608 7609/// \brief Note that the given declaration was referenced in the source code. 7610/// 7611/// This routine should be invoke whenever a given declaration is referenced 7612/// in the source code, and where that reference occurred. If this declaration 7613/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7614/// C99 6.9p3), then the declaration will be marked as used. 7615/// 7616/// \param Loc the location where the declaration was referenced. 7617/// 7618/// \param D the declaration that has been referenced by the source code. 7619void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7620 assert(D && "No declaration?"); 7621 7622 if (D->isUsed(false)) 7623 return; 7624 7625 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7626 // template or not. The reason for this is that unevaluated expressions 7627 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7628 // -Wunused-parameters) 7629 if (isa<ParmVarDecl>(D) || 7630 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7631 D->setUsed(true); 7632 return; 7633 } 7634 7635 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7636 return; 7637 7638 // Do not mark anything as "used" within a dependent context; wait for 7639 // an instantiation. 7640 if (CurContext->isDependentContext()) 7641 return; 7642 7643 switch (ExprEvalContexts.back().Context) { 7644 case Unevaluated: 7645 // We are in an expression that is not potentially evaluated; do nothing. 7646 return; 7647 7648 case PotentiallyEvaluated: 7649 // We are in a potentially-evaluated expression, so this declaration is 7650 // "used"; handle this below. 7651 break; 7652 7653 case PotentiallyPotentiallyEvaluated: 7654 // We are in an expression that may be potentially evaluated; queue this 7655 // declaration reference until we know whether the expression is 7656 // potentially evaluated. 7657 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7658 return; 7659 } 7660 7661 // Note that this declaration has been used. 7662 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7663 unsigned TypeQuals; 7664 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7665 if (Constructor->getParent()->hasTrivialConstructor()) 7666 return; 7667 if (!Constructor->isUsed(false)) 7668 DefineImplicitDefaultConstructor(Loc, Constructor); 7669 } else if (Constructor->isImplicit() && 7670 Constructor->isCopyConstructor(TypeQuals)) { 7671 if (!Constructor->isUsed(false)) 7672 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7673 } 7674 7675 MarkVTableUsed(Loc, Constructor->getParent()); 7676 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7677 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 7678 DefineImplicitDestructor(Loc, Destructor); 7679 if (Destructor->isVirtual()) 7680 MarkVTableUsed(Loc, Destructor->getParent()); 7681 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7682 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7683 MethodDecl->getOverloadedOperator() == OO_Equal) { 7684 if (!MethodDecl->isUsed(false)) 7685 DefineImplicitCopyAssignment(Loc, MethodDecl); 7686 } else if (MethodDecl->isVirtual()) 7687 MarkVTableUsed(Loc, MethodDecl->getParent()); 7688 } 7689 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7690 // Implicit instantiation of function templates and member functions of 7691 // class templates. 7692 if (Function->isImplicitlyInstantiable()) { 7693 bool AlreadyInstantiated = false; 7694 if (FunctionTemplateSpecializationInfo *SpecInfo 7695 = Function->getTemplateSpecializationInfo()) { 7696 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7697 SpecInfo->setPointOfInstantiation(Loc); 7698 else if (SpecInfo->getTemplateSpecializationKind() 7699 == TSK_ImplicitInstantiation) 7700 AlreadyInstantiated = true; 7701 } else if (MemberSpecializationInfo *MSInfo 7702 = Function->getMemberSpecializationInfo()) { 7703 if (MSInfo->getPointOfInstantiation().isInvalid()) 7704 MSInfo->setPointOfInstantiation(Loc); 7705 else if (MSInfo->getTemplateSpecializationKind() 7706 == TSK_ImplicitInstantiation) 7707 AlreadyInstantiated = true; 7708 } 7709 7710 if (!AlreadyInstantiated) { 7711 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7712 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7713 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7714 Loc)); 7715 else 7716 PendingInstantiations.push_back(std::make_pair(Function, Loc)); 7717 } 7718 } else // Walk redefinitions, as some of them may be instantiable. 7719 for (FunctionDecl::redecl_iterator i(Function->redecls_begin()), 7720 e(Function->redecls_end()); i != e; ++i) { 7721 if (!i->isUsed(false) && i->isImplicitlyInstantiable()) 7722 MarkDeclarationReferenced(Loc, *i); 7723 } 7724 7725 // FIXME: keep track of references to static functions 7726 7727 // Recursive functions should be marked when used from another function. 7728 if (CurContext != Function) 7729 Function->setUsed(true); 7730 7731 return; 7732 } 7733 7734 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7735 // Implicit instantiation of static data members of class templates. 7736 if (Var->isStaticDataMember() && 7737 Var->getInstantiatedFromStaticDataMember()) { 7738 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7739 assert(MSInfo && "Missing member specialization information?"); 7740 if (MSInfo->getPointOfInstantiation().isInvalid() && 7741 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7742 MSInfo->setPointOfInstantiation(Loc); 7743 PendingInstantiations.push_back(std::make_pair(Var, Loc)); 7744 } 7745 } 7746 7747 // FIXME: keep track of references to static data? 7748 7749 D->setUsed(true); 7750 return; 7751 } 7752} 7753 7754namespace { 7755 // Mark all of the declarations referenced 7756 // FIXME: Not fully implemented yet! We need to have a better understanding 7757 // of when we're entering 7758 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 7759 Sema &S; 7760 SourceLocation Loc; 7761 7762 public: 7763 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 7764 7765 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 7766 7767 bool TraverseTemplateArgument(const TemplateArgument &Arg); 7768 bool TraverseRecordType(RecordType *T); 7769 }; 7770} 7771 7772bool MarkReferencedDecls::TraverseTemplateArgument( 7773 const TemplateArgument &Arg) { 7774 if (Arg.getKind() == TemplateArgument::Declaration) { 7775 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 7776 } 7777 7778 return Inherited::TraverseTemplateArgument(Arg); 7779} 7780 7781bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 7782 if (ClassTemplateSpecializationDecl *Spec 7783 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 7784 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 7785 return TraverseTemplateArguments(Args.getFlatArgumentList(), 7786 Args.flat_size()); 7787 } 7788 7789 return true; 7790} 7791 7792void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 7793 MarkReferencedDecls Marker(*this, Loc); 7794 Marker.TraverseType(Context.getCanonicalType(T)); 7795} 7796 7797/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7798/// of the program being compiled. 7799/// 7800/// This routine emits the given diagnostic when the code currently being 7801/// type-checked is "potentially evaluated", meaning that there is a 7802/// possibility that the code will actually be executable. Code in sizeof() 7803/// expressions, code used only during overload resolution, etc., are not 7804/// potentially evaluated. This routine will suppress such diagnostics or, 7805/// in the absolutely nutty case of potentially potentially evaluated 7806/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7807/// later. 7808/// 7809/// This routine should be used for all diagnostics that describe the run-time 7810/// behavior of a program, such as passing a non-POD value through an ellipsis. 7811/// Failure to do so will likely result in spurious diagnostics or failures 7812/// during overload resolution or within sizeof/alignof/typeof/typeid. 7813bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7814 const PartialDiagnostic &PD) { 7815 switch (ExprEvalContexts.back().Context ) { 7816 case Unevaluated: 7817 // The argument will never be evaluated, so don't complain. 7818 break; 7819 7820 case PotentiallyEvaluated: 7821 Diag(Loc, PD); 7822 return true; 7823 7824 case PotentiallyPotentiallyEvaluated: 7825 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7826 break; 7827 } 7828 7829 return false; 7830} 7831 7832bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7833 CallExpr *CE, FunctionDecl *FD) { 7834 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7835 return false; 7836 7837 PartialDiagnostic Note = 7838 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7839 << FD->getDeclName() : PDiag(); 7840 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7841 7842 if (RequireCompleteType(Loc, ReturnType, 7843 FD ? 7844 PDiag(diag::err_call_function_incomplete_return) 7845 << CE->getSourceRange() << FD->getDeclName() : 7846 PDiag(diag::err_call_incomplete_return) 7847 << CE->getSourceRange(), 7848 std::make_pair(NoteLoc, Note))) 7849 return true; 7850 7851 return false; 7852} 7853 7854// Diagnose the common s/=/==/ typo. Note that adding parentheses 7855// will prevent this condition from triggering, which is what we want. 7856void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7857 SourceLocation Loc; 7858 7859 unsigned diagnostic = diag::warn_condition_is_assignment; 7860 7861 if (isa<BinaryOperator>(E)) { 7862 BinaryOperator *Op = cast<BinaryOperator>(E); 7863 if (Op->getOpcode() != BO_Assign) 7864 return; 7865 7866 // Greylist some idioms by putting them into a warning subcategory. 7867 if (ObjCMessageExpr *ME 7868 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7869 Selector Sel = ME->getSelector(); 7870 7871 // self = [<foo> init...] 7872 if (isSelfExpr(Op->getLHS()) 7873 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7874 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7875 7876 // <foo> = [<bar> nextObject] 7877 else if (Sel.isUnarySelector() && 7878 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7879 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7880 } 7881 7882 Loc = Op->getOperatorLoc(); 7883 } else if (isa<CXXOperatorCallExpr>(E)) { 7884 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7885 if (Op->getOperator() != OO_Equal) 7886 return; 7887 7888 Loc = Op->getOperatorLoc(); 7889 } else { 7890 // Not an assignment. 7891 return; 7892 } 7893 7894 SourceLocation Open = E->getSourceRange().getBegin(); 7895 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7896 7897 Diag(Loc, diagnostic) << E->getSourceRange(); 7898 Diag(Loc, diag::note_condition_assign_to_comparison) 7899 << FixItHint::CreateReplacement(Loc, "=="); 7900 Diag(Loc, diag::note_condition_assign_silence) 7901 << FixItHint::CreateInsertion(Open, "(") 7902 << FixItHint::CreateInsertion(Close, ")"); 7903} 7904 7905bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7906 DiagnoseAssignmentAsCondition(E); 7907 7908 if (!E->isTypeDependent()) { 7909 DefaultFunctionArrayLvalueConversion(E); 7910 7911 QualType T = E->getType(); 7912 7913 if (getLangOptions().CPlusPlus) { 7914 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7915 return true; 7916 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7917 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7918 << T << E->getSourceRange(); 7919 return true; 7920 } 7921 } 7922 7923 return false; 7924} 7925 7926ExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 7927 Expr *Sub) { 7928 if (!Sub) 7929 return ExprError(); 7930 7931 if (CheckBooleanCondition(Sub, Loc)) 7932 return ExprError(); 7933 7934 return Owned(Sub); 7935} 7936