SemaExpr.cpp revision a7a77ab274626a371e240b9e49c9231bdb7df092
1//===--- SemaExpr.cpp - Semantic Analysis for Expressions -----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "SemaInit.h" 16#include "Lookup.h" 17#include "AnalysisBasedWarnings.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/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/Parse/DeclSpec.h" 33#include "clang/Parse/Designator.h" 34#include "clang/Parse/Scope.h" 35#include "clang/Parse/Template.h" 36using namespace clang; 37 38 39/// \brief Determine whether the use of this declaration is valid, and 40/// emit any corresponding diagnostics. 41/// 42/// This routine diagnoses various problems with referencing 43/// declarations that can occur when using a declaration. For example, 44/// it might warn if a deprecated or unavailable declaration is being 45/// used, or produce an error (and return true) if a C++0x deleted 46/// function is being used. 47/// 48/// If IgnoreDeprecated is set to true, this should not want about deprecated 49/// decls. 50/// 51/// \returns true if there was an error (this declaration cannot be 52/// referenced), false otherwise. 53/// 54bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) { 55 // See if the decl is deprecated. 56 if (D->getAttr<DeprecatedAttr>()) { 57 EmitDeprecationWarning(D, Loc); 58 } 59 60 // See if the decl is unavailable 61 if (D->getAttr<UnavailableAttr>()) { 62 Diag(Loc, diag::warn_unavailable) << D->getDeclName(); 63 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 64 } 65 66 // See if this is a deleted function. 67 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 68 if (FD->isDeleted()) { 69 Diag(Loc, diag::err_deleted_function_use); 70 Diag(D->getLocation(), diag::note_unavailable_here) << true; 71 return true; 72 } 73 } 74 75 return false; 76} 77 78/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 79/// (and other functions in future), which have been declared with sentinel 80/// attribute. It warns if call does not have the sentinel argument. 81/// 82void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 83 Expr **Args, unsigned NumArgs) { 84 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 85 if (!attr) 86 return; 87 88 // FIXME: In C++0x, if any of the arguments are parameter pack 89 // expansions, we can't check for the sentinel now. 90 int sentinelPos = attr->getSentinel(); 91 int nullPos = attr->getNullPos(); 92 93 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 94 // base class. Then we won't be needing two versions of the same code. 95 unsigned int i = 0; 96 bool warnNotEnoughArgs = false; 97 int isMethod = 0; 98 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 99 // skip over named parameters. 100 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 101 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 102 if (nullPos) 103 --nullPos; 104 else 105 ++i; 106 } 107 warnNotEnoughArgs = (P != E || i >= NumArgs); 108 isMethod = 1; 109 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 110 // skip over named parameters. 111 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 112 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 113 if (nullPos) 114 --nullPos; 115 else 116 ++i; 117 } 118 warnNotEnoughArgs = (P != E || i >= NumArgs); 119 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 120 // block or function pointer call. 121 QualType Ty = V->getType(); 122 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 123 const FunctionType *FT = Ty->isFunctionPointerType() 124 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 125 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 126 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 127 unsigned NumArgsInProto = Proto->getNumArgs(); 128 unsigned k; 129 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 130 if (nullPos) 131 --nullPos; 132 else 133 ++i; 134 } 135 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 136 } 137 if (Ty->isBlockPointerType()) 138 isMethod = 2; 139 } else 140 return; 141 } else 142 return; 143 144 if (warnNotEnoughArgs) { 145 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 146 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 147 return; 148 } 149 int sentinel = i; 150 while (sentinelPos > 0 && i < NumArgs-1) { 151 --sentinelPos; 152 ++i; 153 } 154 if (sentinelPos > 0) { 155 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 156 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 157 return; 158 } 159 while (i < NumArgs-1) { 160 ++i; 161 ++sentinel; 162 } 163 Expr *sentinelExpr = Args[sentinel]; 164 if (!sentinelExpr) return; 165 if (sentinelExpr->isTypeDependent()) return; 166 if (sentinelExpr->isValueDependent()) return; 167 if (sentinelExpr->getType()->isAnyPointerType() && 168 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 169 Expr::NPC_ValueDependentIsNull)) 170 return; 171 172 // Unfortunately, __null has type 'int'. 173 if (isa<GNUNullExpr>(sentinelExpr)) return; 174 175 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 176 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 177} 178 179SourceRange Sema::getExprRange(ExprTy *E) const { 180 Expr *Ex = (Expr *)E; 181 return Ex? Ex->getSourceRange() : SourceRange(); 182} 183 184//===----------------------------------------------------------------------===// 185// Standard Promotions and Conversions 186//===----------------------------------------------------------------------===// 187 188/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 189void Sema::DefaultFunctionArrayConversion(Expr *&E) { 190 QualType Ty = E->getType(); 191 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 192 193 if (Ty->isFunctionType()) 194 ImpCastExprToType(E, Context.getPointerType(Ty), 195 CastExpr::CK_FunctionToPointerDecay); 196 else if (Ty->isArrayType()) { 197 // In C90 mode, arrays only promote to pointers if the array expression is 198 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 199 // type 'array of type' is converted to an expression that has type 'pointer 200 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 201 // that has type 'array of type' ...". The relevant change is "an lvalue" 202 // (C90) to "an expression" (C99). 203 // 204 // C++ 4.2p1: 205 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 206 // T" can be converted to an rvalue of type "pointer to T". 207 // 208 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 209 E->isLvalue(Context) == Expr::LV_Valid) 210 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 211 CastExpr::CK_ArrayToPointerDecay); 212 } 213} 214 215void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 216 DefaultFunctionArrayConversion(E); 217 218 QualType Ty = E->getType(); 219 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 220 if (!Ty->isDependentType() && Ty.hasQualifiers() && 221 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 222 E->isLvalue(Context) == Expr::LV_Valid) { 223 // C++ [conv.lval]p1: 224 // [...] If T is a non-class type, the type of the rvalue is the 225 // cv-unqualified version of T. Otherwise, the type of the 226 // rvalue is T 227 // 228 // C99 6.3.2.1p2: 229 // If the lvalue has qualified type, the value has the unqualified 230 // version of the type of the lvalue; otherwise, the value has the 231 // type of the lvalue. 232 ImpCastExprToType(E, Ty.getUnqualifiedType(), CastExpr::CK_NoOp); 233 } 234} 235 236 237/// UsualUnaryConversions - Performs various conversions that are common to most 238/// operators (C99 6.3). The conversions of array and function types are 239/// sometimes surpressed. For example, the array->pointer conversion doesn't 240/// apply if the array is an argument to the sizeof or address (&) operators. 241/// In these instances, this routine should *not* be called. 242Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 243 QualType Ty = Expr->getType(); 244 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 245 246 // C99 6.3.1.1p2: 247 // 248 // The following may be used in an expression wherever an int or 249 // unsigned int may be used: 250 // - an object or expression with an integer type whose integer 251 // conversion rank is less than or equal to the rank of int 252 // and unsigned int. 253 // - A bit-field of type _Bool, int, signed int, or unsigned int. 254 // 255 // If an int can represent all values of the original type, the 256 // value is converted to an int; otherwise, it is converted to an 257 // unsigned int. These are called the integer promotions. All 258 // other types are unchanged by the integer promotions. 259 QualType PTy = Context.isPromotableBitField(Expr); 260 if (!PTy.isNull()) { 261 ImpCastExprToType(Expr, PTy, CastExpr::CK_IntegralCast); 262 return Expr; 263 } 264 if (Ty->isPromotableIntegerType()) { 265 QualType PT = Context.getPromotedIntegerType(Ty); 266 ImpCastExprToType(Expr, PT, CastExpr::CK_IntegralCast); 267 return Expr; 268 } 269 270 DefaultFunctionArrayLvalueConversion(Expr); 271 return Expr; 272} 273 274/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 275/// do not have a prototype. Arguments that have type float are promoted to 276/// double. All other argument types are converted by UsualUnaryConversions(). 277void Sema::DefaultArgumentPromotion(Expr *&Expr) { 278 QualType Ty = Expr->getType(); 279 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 280 281 // If this is a 'float' (CVR qualified or typedef) promote to double. 282 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 283 return ImpCastExprToType(Expr, Context.DoubleTy, 284 CastExpr::CK_FloatingCast); 285 286 UsualUnaryConversions(Expr); 287} 288 289/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 290/// will warn if the resulting type is not a POD type, and rejects ObjC 291/// interfaces passed by value. This returns true if the argument type is 292/// completely illegal. 293bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 294 FunctionDecl *FDecl) { 295 DefaultArgumentPromotion(Expr); 296 297 // __builtin_va_start takes the second argument as a "varargs" argument, but 298 // it doesn't actually do anything with it. It doesn't need to be non-pod 299 // etc. 300 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 301 return false; 302 303 if (Expr->getType()->isObjCObjectType() && 304 DiagRuntimeBehavior(Expr->getLocStart(), 305 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 306 << Expr->getType() << CT)) 307 return true; 308 309 if (!Expr->getType()->isPODType() && 310 DiagRuntimeBehavior(Expr->getLocStart(), 311 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 312 << Expr->getType() << CT)) 313 return true; 314 315 return false; 316} 317 318 319/// UsualArithmeticConversions - Performs various conversions that are common to 320/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 321/// routine returns the first non-arithmetic type found. The client is 322/// responsible for emitting appropriate error diagnostics. 323/// FIXME: verify the conversion rules for "complex int" are consistent with 324/// GCC. 325QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 326 bool isCompAssign) { 327 if (!isCompAssign) 328 UsualUnaryConversions(lhsExpr); 329 330 UsualUnaryConversions(rhsExpr); 331 332 // For conversion purposes, we ignore any qualifiers. 333 // For example, "const float" and "float" are equivalent. 334 QualType lhs = 335 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 336 QualType rhs = 337 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 338 339 // If both types are identical, no conversion is needed. 340 if (lhs == rhs) 341 return lhs; 342 343 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 344 // The caller can deal with this (e.g. pointer + int). 345 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 346 return lhs; 347 348 // Perform bitfield promotions. 349 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 350 if (!LHSBitfieldPromoteTy.isNull()) 351 lhs = LHSBitfieldPromoteTy; 352 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 353 if (!RHSBitfieldPromoteTy.isNull()) 354 rhs = RHSBitfieldPromoteTy; 355 356 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 357 if (!isCompAssign) 358 ImpCastExprToType(lhsExpr, destType, CastExpr::CK_Unknown); 359 ImpCastExprToType(rhsExpr, destType, CastExpr::CK_Unknown); 360 return destType; 361} 362 363//===----------------------------------------------------------------------===// 364// Semantic Analysis for various Expression Types 365//===----------------------------------------------------------------------===// 366 367 368/// ActOnStringLiteral - The specified tokens were lexed as pasted string 369/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 370/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 371/// multiple tokens. However, the common case is that StringToks points to one 372/// string. 373/// 374Action::OwningExprResult 375Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 376 assert(NumStringToks && "Must have at least one string!"); 377 378 StringLiteralParser Literal(StringToks, NumStringToks, PP); 379 if (Literal.hadError) 380 return ExprError(); 381 382 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 383 for (unsigned i = 0; i != NumStringToks; ++i) 384 StringTokLocs.push_back(StringToks[i].getLocation()); 385 386 QualType StrTy = Context.CharTy; 387 if (Literal.AnyWide) StrTy = Context.getWCharType(); 388 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 389 390 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 391 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 392 StrTy.addConst(); 393 394 // Get an array type for the string, according to C99 6.4.5. This includes 395 // the nul terminator character as well as the string length for pascal 396 // strings. 397 StrTy = Context.getConstantArrayType(StrTy, 398 llvm::APInt(32, Literal.GetNumStringChars()+1), 399 ArrayType::Normal, 0); 400 401 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 402 return Owned(StringLiteral::Create(Context, Literal.GetString(), 403 Literal.GetStringLength(), 404 Literal.AnyWide, StrTy, 405 &StringTokLocs[0], 406 StringTokLocs.size())); 407} 408 409/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 410/// CurBlock to VD should cause it to be snapshotted (as we do for auto 411/// variables defined outside the block) or false if this is not needed (e.g. 412/// for values inside the block or for globals). 413/// 414/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 415/// up-to-date. 416/// 417static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 418 ValueDecl *VD) { 419 // If the value is defined inside the block, we couldn't snapshot it even if 420 // we wanted to. 421 if (CurBlock->TheDecl == VD->getDeclContext()) 422 return false; 423 424 // If this is an enum constant or function, it is constant, don't snapshot. 425 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 426 return false; 427 428 // If this is a reference to an extern, static, or global variable, no need to 429 // snapshot it. 430 // FIXME: What about 'const' variables in C++? 431 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 432 if (!Var->hasLocalStorage()) 433 return false; 434 435 // Blocks that have these can't be constant. 436 CurBlock->hasBlockDeclRefExprs = true; 437 438 // If we have nested blocks, the decl may be declared in an outer block (in 439 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 440 // be defined outside all of the current blocks (in which case the blocks do 441 // all get the bit). Walk the nesting chain. 442 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 443 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 444 445 if (!NextBlock) 446 continue; 447 448 // If we found the defining block for the variable, don't mark the block as 449 // having a reference outside it. 450 if (NextBlock->TheDecl == VD->getDeclContext()) 451 break; 452 453 // Otherwise, the DeclRef from the inner block causes the outer one to need 454 // a snapshot as well. 455 NextBlock->hasBlockDeclRefExprs = true; 456 } 457 458 return true; 459} 460 461 462 463/// BuildDeclRefExpr - Build a DeclRefExpr. 464Sema::OwningExprResult 465Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, SourceLocation Loc, 466 const CXXScopeSpec *SS) { 467 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 468 Diag(Loc, 469 diag::err_auto_variable_cannot_appear_in_own_initializer) 470 << D->getDeclName(); 471 return ExprError(); 472 } 473 474 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 475 if (isa<NonTypeTemplateParmDecl>(VD)) { 476 // Non-type template parameters can be referenced anywhere they are 477 // visible. 478 Ty = Ty.getNonLValueExprType(Context); 479 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 480 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 481 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 482 Diag(Loc, diag::err_reference_to_local_var_in_enclosing_function) 483 << D->getIdentifier() << FD->getDeclName(); 484 Diag(D->getLocation(), diag::note_local_variable_declared_here) 485 << D->getIdentifier(); 486 return ExprError(); 487 } 488 } 489 } 490 } 491 492 MarkDeclarationReferenced(Loc, D); 493 494 return Owned(DeclRefExpr::Create(Context, 495 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 496 SS? SS->getRange() : SourceRange(), 497 D, Loc, Ty)); 498} 499 500/// \brief Given a field that represents a member of an anonymous 501/// struct/union, build the path from that field's context to the 502/// actual member. 503/// 504/// Construct the sequence of field member references we'll have to 505/// perform to get to the field in the anonymous union/struct. The 506/// list of members is built from the field outward, so traverse it 507/// backwards to go from an object in the current context to the field 508/// we found. 509/// 510/// \returns The variable from which the field access should begin, 511/// for an anonymous struct/union that is not a member of another 512/// class. Otherwise, returns NULL. 513VarDecl *Sema::BuildAnonymousStructUnionMemberPath(FieldDecl *Field, 514 llvm::SmallVectorImpl<FieldDecl *> &Path) { 515 assert(Field->getDeclContext()->isRecord() && 516 cast<RecordDecl>(Field->getDeclContext())->isAnonymousStructOrUnion() 517 && "Field must be stored inside an anonymous struct or union"); 518 519 Path.push_back(Field); 520 VarDecl *BaseObject = 0; 521 DeclContext *Ctx = Field->getDeclContext(); 522 do { 523 RecordDecl *Record = cast<RecordDecl>(Ctx); 524 ValueDecl *AnonObject = Record->getAnonymousStructOrUnionObject(); 525 if (FieldDecl *AnonField = dyn_cast<FieldDecl>(AnonObject)) 526 Path.push_back(AnonField); 527 else { 528 BaseObject = cast<VarDecl>(AnonObject); 529 break; 530 } 531 Ctx = Ctx->getParent(); 532 } while (Ctx->isRecord() && 533 cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()); 534 535 return BaseObject; 536} 537 538Sema::OwningExprResult 539Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 540 FieldDecl *Field, 541 Expr *BaseObjectExpr, 542 SourceLocation OpLoc) { 543 llvm::SmallVector<FieldDecl *, 4> AnonFields; 544 VarDecl *BaseObject = BuildAnonymousStructUnionMemberPath(Field, 545 AnonFields); 546 547 // Build the expression that refers to the base object, from 548 // which we will build a sequence of member references to each 549 // of the anonymous union objects and, eventually, the field we 550 // found via name lookup. 551 bool BaseObjectIsPointer = false; 552 Qualifiers BaseQuals; 553 if (BaseObject) { 554 // BaseObject is an anonymous struct/union variable (and is, 555 // therefore, not part of another non-anonymous record). 556 if (BaseObjectExpr) BaseObjectExpr->Destroy(Context); 557 MarkDeclarationReferenced(Loc, BaseObject); 558 BaseObjectExpr = new (Context) DeclRefExpr(BaseObject,BaseObject->getType(), 559 SourceLocation()); 560 BaseQuals 561 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 562 } else if (BaseObjectExpr) { 563 // The caller provided the base object expression. Determine 564 // whether its a pointer and whether it adds any qualifiers to the 565 // anonymous struct/union fields we're looking into. 566 QualType ObjectType = BaseObjectExpr->getType(); 567 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 568 BaseObjectIsPointer = true; 569 ObjectType = ObjectPtr->getPointeeType(); 570 } 571 BaseQuals 572 = Context.getCanonicalType(ObjectType).getQualifiers(); 573 } else { 574 // We've found a member of an anonymous struct/union that is 575 // inside a non-anonymous struct/union, so in a well-formed 576 // program our base object expression is "this". 577 DeclContext *DC = getFunctionLevelDeclContext(); 578 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 579 if (!MD->isStatic()) { 580 QualType AnonFieldType 581 = Context.getTagDeclType( 582 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 583 QualType ThisType = Context.getTagDeclType(MD->getParent()); 584 if ((Context.getCanonicalType(AnonFieldType) 585 == Context.getCanonicalType(ThisType)) || 586 IsDerivedFrom(ThisType, AnonFieldType)) { 587 // Our base object expression is "this". 588 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 589 MD->getThisType(Context), 590 /*isImplicit=*/true); 591 BaseObjectIsPointer = true; 592 } 593 } else { 594 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 595 << Field->getDeclName()); 596 } 597 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 598 } 599 600 if (!BaseObjectExpr) 601 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 602 << Field->getDeclName()); 603 } 604 605 // Build the implicit member references to the field of the 606 // anonymous struct/union. 607 Expr *Result = BaseObjectExpr; 608 Qualifiers ResultQuals = BaseQuals; 609 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 610 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 611 FI != FIEnd; ++FI) { 612 QualType MemberType = (*FI)->getType(); 613 Qualifiers MemberTypeQuals = 614 Context.getCanonicalType(MemberType).getQualifiers(); 615 616 // CVR attributes from the base are picked up by members, 617 // except that 'mutable' members don't pick up 'const'. 618 if ((*FI)->isMutable()) 619 ResultQuals.removeConst(); 620 621 // GC attributes are never picked up by members. 622 ResultQuals.removeObjCGCAttr(); 623 624 // TR 18037 does not allow fields to be declared with address spaces. 625 assert(!MemberTypeQuals.hasAddressSpace()); 626 627 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 628 if (NewQuals != MemberTypeQuals) 629 MemberType = Context.getQualifiedType(MemberType, NewQuals); 630 631 MarkDeclarationReferenced(Loc, *FI); 632 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 633 // FIXME: Might this end up being a qualified name? 634 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 635 OpLoc, MemberType); 636 BaseObjectIsPointer = false; 637 ResultQuals = NewQuals; 638 } 639 640 return Owned(Result); 641} 642 643/// Decomposes the given name into a DeclarationName, its location, and 644/// possibly a list of template arguments. 645/// 646/// If this produces template arguments, it is permitted to call 647/// DecomposeTemplateName. 648/// 649/// This actually loses a lot of source location information for 650/// non-standard name kinds; we should consider preserving that in 651/// some way. 652static void DecomposeUnqualifiedId(Sema &SemaRef, 653 const UnqualifiedId &Id, 654 TemplateArgumentListInfo &Buffer, 655 DeclarationName &Name, 656 SourceLocation &NameLoc, 657 const TemplateArgumentListInfo *&TemplateArgs) { 658 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 659 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 660 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 661 662 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 663 Id.TemplateId->getTemplateArgs(), 664 Id.TemplateId->NumArgs); 665 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 666 TemplateArgsPtr.release(); 667 668 TemplateName TName = 669 Sema::TemplateTy::make(Id.TemplateId->Template).getAsVal<TemplateName>(); 670 671 Name = SemaRef.Context.getNameForTemplate(TName); 672 NameLoc = Id.TemplateId->TemplateNameLoc; 673 TemplateArgs = &Buffer; 674 } else { 675 Name = SemaRef.GetNameFromUnqualifiedId(Id); 676 NameLoc = Id.StartLocation; 677 TemplateArgs = 0; 678 } 679} 680 681/// Determines whether the given record is "fully-formed" at the given 682/// location, i.e. whether a qualified lookup into it is assured of 683/// getting consistent results already. 684static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 685 if (!Record->hasDefinition()) 686 return false; 687 688 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 689 E = Record->bases_end(); I != E; ++I) { 690 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 691 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 692 if (!BaseRT) return false; 693 694 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 695 if (!BaseRecord->hasDefinition() || 696 !IsFullyFormedScope(SemaRef, BaseRecord)) 697 return false; 698 } 699 700 return true; 701} 702 703/// Determines whether we can lookup this id-expression now or whether 704/// we have to wait until template instantiation is complete. 705static bool IsDependentIdExpression(Sema &SemaRef, const CXXScopeSpec &SS) { 706 DeclContext *DC = SemaRef.computeDeclContext(SS, false); 707 708 // If the qualifier scope isn't computable, it's definitely dependent. 709 if (!DC) return true; 710 711 // If the qualifier scope doesn't name a record, we can always look into it. 712 if (!isa<CXXRecordDecl>(DC)) return false; 713 714 // We can't look into record types unless they're fully-formed. 715 if (!IsFullyFormedScope(SemaRef, cast<CXXRecordDecl>(DC))) return true; 716 717 return false; 718} 719 720/// Determines if the given class is provably not derived from all of 721/// the prospective base classes. 722static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 723 CXXRecordDecl *Record, 724 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 725 if (Bases.count(Record->getCanonicalDecl())) 726 return false; 727 728 RecordDecl *RD = Record->getDefinition(); 729 if (!RD) return false; 730 Record = cast<CXXRecordDecl>(RD); 731 732 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 733 E = Record->bases_end(); I != E; ++I) { 734 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 735 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 736 if (!BaseRT) return false; 737 738 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 739 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 740 return false; 741 } 742 743 return true; 744} 745 746enum IMAKind { 747 /// The reference is definitely not an instance member access. 748 IMA_Static, 749 750 /// The reference may be an implicit instance member access. 751 IMA_Mixed, 752 753 /// The reference may be to an instance member, but it is invalid if 754 /// so, because the context is not an instance method. 755 IMA_Mixed_StaticContext, 756 757 /// The reference may be to an instance member, but it is invalid if 758 /// so, because the context is from an unrelated class. 759 IMA_Mixed_Unrelated, 760 761 /// The reference is definitely an implicit instance member access. 762 IMA_Instance, 763 764 /// The reference may be to an unresolved using declaration. 765 IMA_Unresolved, 766 767 /// The reference may be to an unresolved using declaration and the 768 /// context is not an instance method. 769 IMA_Unresolved_StaticContext, 770 771 /// The reference is to a member of an anonymous structure in a 772 /// non-class context. 773 IMA_AnonymousMember, 774 775 /// All possible referrents are instance members and the current 776 /// context is not an instance method. 777 IMA_Error_StaticContext, 778 779 /// All possible referrents are instance members of an unrelated 780 /// class. 781 IMA_Error_Unrelated 782}; 783 784/// The given lookup names class member(s) and is not being used for 785/// an address-of-member expression. Classify the type of access 786/// according to whether it's possible that this reference names an 787/// instance member. This is best-effort; it is okay to 788/// conservatively answer "yes", in which case some errors will simply 789/// not be caught until template-instantiation. 790static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 791 const LookupResult &R) { 792 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 793 794 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 795 bool isStaticContext = 796 (!isa<CXXMethodDecl>(DC) || 797 cast<CXXMethodDecl>(DC)->isStatic()); 798 799 if (R.isUnresolvableResult()) 800 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 801 802 // Collect all the declaring classes of instance members we find. 803 bool hasNonInstance = false; 804 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 805 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 806 NamedDecl *D = *I; 807 if (D->isCXXInstanceMember()) { 808 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 809 810 // If this is a member of an anonymous record, move out to the 811 // innermost non-anonymous struct or union. If there isn't one, 812 // that's a special case. 813 while (R->isAnonymousStructOrUnion()) { 814 R = dyn_cast<CXXRecordDecl>(R->getParent()); 815 if (!R) return IMA_AnonymousMember; 816 } 817 Classes.insert(R->getCanonicalDecl()); 818 } 819 else 820 hasNonInstance = true; 821 } 822 823 // If we didn't find any instance members, it can't be an implicit 824 // member reference. 825 if (Classes.empty()) 826 return IMA_Static; 827 828 // If the current context is not an instance method, it can't be 829 // an implicit member reference. 830 if (isStaticContext) 831 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 832 833 // If we can prove that the current context is unrelated to all the 834 // declaring classes, it can't be an implicit member reference (in 835 // which case it's an error if any of those members are selected). 836 if (IsProvablyNotDerivedFrom(SemaRef, 837 cast<CXXMethodDecl>(DC)->getParent(), 838 Classes)) 839 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 840 841 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 842} 843 844/// Diagnose a reference to a field with no object available. 845static void DiagnoseInstanceReference(Sema &SemaRef, 846 const CXXScopeSpec &SS, 847 const LookupResult &R) { 848 SourceLocation Loc = R.getNameLoc(); 849 SourceRange Range(Loc); 850 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 851 852 if (R.getAsSingle<FieldDecl>()) { 853 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 854 if (MD->isStatic()) { 855 // "invalid use of member 'x' in static member function" 856 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 857 << Range << R.getLookupName(); 858 return; 859 } 860 } 861 862 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 863 << R.getLookupName() << Range; 864 return; 865 } 866 867 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 868} 869 870/// Diagnose an empty lookup. 871/// 872/// \return false if new lookup candidates were found 873bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 874 CorrectTypoContext CTC) { 875 DeclarationName Name = R.getLookupName(); 876 877 unsigned diagnostic = diag::err_undeclared_var_use; 878 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 879 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 880 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 881 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 882 diagnostic = diag::err_undeclared_use; 883 diagnostic_suggest = diag::err_undeclared_use_suggest; 884 } 885 886 // If the original lookup was an unqualified lookup, fake an 887 // unqualified lookup. This is useful when (for example) the 888 // original lookup would not have found something because it was a 889 // dependent name. 890 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 891 DC; DC = DC->getParent()) { 892 if (isa<CXXRecordDecl>(DC)) { 893 LookupQualifiedName(R, DC); 894 895 if (!R.empty()) { 896 // Don't give errors about ambiguities in this lookup. 897 R.suppressDiagnostics(); 898 899 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 900 bool isInstance = CurMethod && 901 CurMethod->isInstance() && 902 DC == CurMethod->getParent(); 903 904 // Give a code modification hint to insert 'this->'. 905 // TODO: fixit for inserting 'Base<T>::' in the other cases. 906 // Actually quite difficult! 907 if (isInstance) { 908 Diag(R.getNameLoc(), diagnostic) << Name 909 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 910 911 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 912 CallsUndergoingInstantiation.back()->getCallee()); 913 CXXMethodDecl *DepMethod = cast<CXXMethodDecl>( 914 CurMethod->getInstantiatedFromMemberFunction()); 915 QualType DepThisType = DepMethod->getThisType(Context); 916 CXXThisExpr *DepThis = new (Context) CXXThisExpr(R.getNameLoc(), 917 DepThisType, false); 918 TemplateArgumentListInfo TList; 919 if (ULE->hasExplicitTemplateArgs()) 920 ULE->copyTemplateArgumentsInto(TList); 921 CXXDependentScopeMemberExpr *DepExpr = 922 CXXDependentScopeMemberExpr::Create( 923 Context, DepThis, DepThisType, true, SourceLocation(), 924 ULE->getQualifier(), ULE->getQualifierRange(), NULL, Name, 925 R.getNameLoc(), &TList); 926 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 927 } else { 928 Diag(R.getNameLoc(), diagnostic) << Name; 929 } 930 931 // Do we really want to note all of these? 932 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 933 Diag((*I)->getLocation(), diag::note_dependent_var_use); 934 935 // Tell the callee to try to recover. 936 return false; 937 } 938 } 939 } 940 941 // We didn't find anything, so try to correct for a typo. 942 DeclarationName Corrected; 943 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 944 if (!R.empty()) { 945 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 946 if (SS.isEmpty()) 947 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 948 << FixItHint::CreateReplacement(R.getNameLoc(), 949 R.getLookupName().getAsString()); 950 else 951 Diag(R.getNameLoc(), diag::err_no_member_suggest) 952 << Name << computeDeclContext(SS, false) << R.getLookupName() 953 << SS.getRange() 954 << FixItHint::CreateReplacement(R.getNameLoc(), 955 R.getLookupName().getAsString()); 956 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 957 Diag(ND->getLocation(), diag::note_previous_decl) 958 << ND->getDeclName(); 959 960 // Tell the callee to try to recover. 961 return false; 962 } 963 964 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 965 // FIXME: If we ended up with a typo for a type name or 966 // Objective-C class name, we're in trouble because the parser 967 // is in the wrong place to recover. Suggest the typo 968 // correction, but don't make it a fix-it since we're not going 969 // to recover well anyway. 970 if (SS.isEmpty()) 971 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 972 else 973 Diag(R.getNameLoc(), diag::err_no_member_suggest) 974 << Name << computeDeclContext(SS, false) << R.getLookupName() 975 << SS.getRange(); 976 977 // Don't try to recover; it won't work. 978 return true; 979 } 980 } else { 981 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 982 // because we aren't able to recover. 983 if (SS.isEmpty()) 984 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 985 else 986 Diag(R.getNameLoc(), diag::err_no_member_suggest) 987 << Name << computeDeclContext(SS, false) << Corrected 988 << SS.getRange(); 989 return true; 990 } 991 R.clear(); 992 } 993 994 // Emit a special diagnostic for failed member lookups. 995 // FIXME: computing the declaration context might fail here (?) 996 if (!SS.isEmpty()) { 997 Diag(R.getNameLoc(), diag::err_no_member) 998 << Name << computeDeclContext(SS, false) 999 << SS.getRange(); 1000 return true; 1001 } 1002 1003 // Give up, we can't recover. 1004 Diag(R.getNameLoc(), diagnostic) << Name; 1005 return true; 1006} 1007 1008static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1009 IdentifierInfo *II, 1010 SourceLocation NameLoc) { 1011 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1012 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1013 if (!IDecl) 1014 return 0; 1015 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1016 if (!ClassImpDecl) 1017 return 0; 1018 bool DynamicImplSeen = false; 1019 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1020 if (!property) 1021 return 0; 1022 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1023 DynamicImplSeen = 1024 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1025 if (!DynamicImplSeen) { 1026 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1027 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1028 NameLoc, 1029 II, PropType, /*Dinfo=*/0, 1030 ObjCIvarDecl::Protected, 1031 (Expr *)0, true); 1032 ClassImpDecl->addDecl(Ivar); 1033 IDecl->makeDeclVisibleInContext(Ivar, false); 1034 property->setPropertyIvarDecl(Ivar); 1035 return Ivar; 1036 } 1037 return 0; 1038} 1039 1040Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S, 1041 CXXScopeSpec &SS, 1042 UnqualifiedId &Id, 1043 bool HasTrailingLParen, 1044 bool isAddressOfOperand) { 1045 assert(!(isAddressOfOperand && HasTrailingLParen) && 1046 "cannot be direct & operand and have a trailing lparen"); 1047 1048 if (SS.isInvalid()) 1049 return ExprError(); 1050 1051 TemplateArgumentListInfo TemplateArgsBuffer; 1052 1053 // Decompose the UnqualifiedId into the following data. 1054 DeclarationName Name; 1055 SourceLocation NameLoc; 1056 const TemplateArgumentListInfo *TemplateArgs; 1057 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 1058 Name, NameLoc, TemplateArgs); 1059 1060 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1061 1062 // C++ [temp.dep.expr]p3: 1063 // An id-expression is type-dependent if it contains: 1064 // -- an identifier that was declared with a dependent type, 1065 // (note: handled after lookup) 1066 // -- a template-id that is dependent, 1067 // (note: handled in BuildTemplateIdExpr) 1068 // -- a conversion-function-id that specifies a dependent type, 1069 // -- a nested-name-specifier that contains a class-name that 1070 // names a dependent type. 1071 // Determine whether this is a member of an unknown specialization; 1072 // we need to handle these differently. 1073 if ((Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1074 Name.getCXXNameType()->isDependentType()) || 1075 (SS.isSet() && IsDependentIdExpression(*this, SS))) { 1076 return ActOnDependentIdExpression(SS, Name, NameLoc, 1077 isAddressOfOperand, 1078 TemplateArgs); 1079 } 1080 1081 // Perform the required lookup. 1082 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1083 if (TemplateArgs) { 1084 // Lookup the template name again to correctly establish the context in 1085 // which it was found. This is really unfortunate as we already did the 1086 // lookup to determine that it was a template name in the first place. If 1087 // this becomes a performance hit, we can work harder to preserve those 1088 // results until we get here but it's likely not worth it. 1089 bool MemberOfUnknownSpecialization; 1090 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1091 MemberOfUnknownSpecialization); 1092 } else { 1093 bool IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1094 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1095 1096 // If this reference is in an Objective-C method, then we need to do 1097 // some special Objective-C lookup, too. 1098 if (IvarLookupFollowUp) { 1099 OwningExprResult E(LookupInObjCMethod(R, S, II, true)); 1100 if (E.isInvalid()) 1101 return ExprError(); 1102 1103 Expr *Ex = E.takeAs<Expr>(); 1104 if (Ex) return Owned(Ex); 1105 // Synthesize ivars lazily 1106 if (getLangOptions().ObjCNonFragileABI2) { 1107 if (SynthesizeProvisionalIvar(*this, II, NameLoc)) 1108 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1109 isAddressOfOperand); 1110 } 1111 } 1112 } 1113 1114 if (R.isAmbiguous()) 1115 return ExprError(); 1116 1117 // Determine whether this name might be a candidate for 1118 // argument-dependent lookup. 1119 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1120 1121 if (R.empty() && !ADL) { 1122 // Otherwise, this could be an implicitly declared function reference (legal 1123 // in C90, extension in C99, forbidden in C++). 1124 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1125 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1126 if (D) R.addDecl(D); 1127 } 1128 1129 // If this name wasn't predeclared and if this is not a function 1130 // call, diagnose the problem. 1131 if (R.empty()) { 1132 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1133 return ExprError(); 1134 1135 assert(!R.empty() && 1136 "DiagnoseEmptyLookup returned false but added no results"); 1137 1138 // If we found an Objective-C instance variable, let 1139 // LookupInObjCMethod build the appropriate expression to 1140 // reference the ivar. 1141 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1142 R.clear(); 1143 OwningExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1144 assert(E.isInvalid() || E.get()); 1145 return move(E); 1146 } 1147 } 1148 } 1149 1150 // This is guaranteed from this point on. 1151 assert(!R.empty() || ADL); 1152 1153 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1154 // Warn about constructs like: 1155 // if (void *X = foo()) { ... } else { X }. 1156 // In the else block, the pointer is always false. 1157 if (Var->isDeclaredInCondition() && Var->getType()->isScalarType()) { 1158 Scope *CheckS = S; 1159 while (CheckS && CheckS->getControlParent()) { 1160 if ((CheckS->getFlags() & Scope::ElseScope) && 1161 CheckS->getControlParent()->isDeclScope(DeclPtrTy::make(Var))) { 1162 ExprError(Diag(NameLoc, diag::warn_value_always_zero) 1163 << Var->getDeclName() 1164 << (Var->getType()->isPointerType() ? 2 : 1165 Var->getType()->isBooleanType() ? 1 : 0)); 1166 break; 1167 } 1168 1169 // Move to the parent of this scope. 1170 CheckS = CheckS->getParent(); 1171 } 1172 } 1173 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1174 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1175 // C99 DR 316 says that, if a function type comes from a 1176 // function definition (without a prototype), that type is only 1177 // used for checking compatibility. Therefore, when referencing 1178 // the function, we pretend that we don't have the full function 1179 // type. 1180 if (DiagnoseUseOfDecl(Func, NameLoc)) 1181 return ExprError(); 1182 1183 QualType T = Func->getType(); 1184 QualType NoProtoType = T; 1185 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1186 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1187 Proto->getExtInfo()); 1188 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1189 } 1190 } 1191 1192 // Check whether this might be a C++ implicit instance member access. 1193 // C++ [expr.prim.general]p6: 1194 // Within the definition of a non-static member function, an 1195 // identifier that names a non-static member is transformed to a 1196 // class member access expression. 1197 // But note that &SomeClass::foo is grammatically distinct, even 1198 // though we don't parse it that way. 1199 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1200 bool isAbstractMemberPointer = (isAddressOfOperand && !SS.isEmpty()); 1201 if (!isAbstractMemberPointer) 1202 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1203 } 1204 1205 if (TemplateArgs) 1206 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1207 1208 return BuildDeclarationNameExpr(SS, R, ADL); 1209} 1210 1211/// Builds an expression which might be an implicit member expression. 1212Sema::OwningExprResult 1213Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1214 LookupResult &R, 1215 const TemplateArgumentListInfo *TemplateArgs) { 1216 switch (ClassifyImplicitMemberAccess(*this, R)) { 1217 case IMA_Instance: 1218 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1219 1220 case IMA_AnonymousMember: 1221 assert(R.isSingleResult()); 1222 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1223 R.getAsSingle<FieldDecl>()); 1224 1225 case IMA_Mixed: 1226 case IMA_Mixed_Unrelated: 1227 case IMA_Unresolved: 1228 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1229 1230 case IMA_Static: 1231 case IMA_Mixed_StaticContext: 1232 case IMA_Unresolved_StaticContext: 1233 if (TemplateArgs) 1234 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1235 return BuildDeclarationNameExpr(SS, R, false); 1236 1237 case IMA_Error_StaticContext: 1238 case IMA_Error_Unrelated: 1239 DiagnoseInstanceReference(*this, SS, R); 1240 return ExprError(); 1241 } 1242 1243 llvm_unreachable("unexpected instance member access kind"); 1244 return ExprError(); 1245} 1246 1247/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1248/// declaration name, generally during template instantiation. 1249/// There's a large number of things which don't need to be done along 1250/// this path. 1251Sema::OwningExprResult 1252Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1253 DeclarationName Name, 1254 SourceLocation NameLoc) { 1255 DeclContext *DC; 1256 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1257 return BuildDependentDeclRefExpr(SS, Name, NameLoc, 0); 1258 1259 if (RequireCompleteDeclContext(SS, DC)) 1260 return ExprError(); 1261 1262 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1263 LookupQualifiedName(R, DC); 1264 1265 if (R.isAmbiguous()) 1266 return ExprError(); 1267 1268 if (R.empty()) { 1269 Diag(NameLoc, diag::err_no_member) << Name << DC << SS.getRange(); 1270 return ExprError(); 1271 } 1272 1273 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1274} 1275 1276/// LookupInObjCMethod - The parser has read a name in, and Sema has 1277/// detected that we're currently inside an ObjC method. Perform some 1278/// additional lookup. 1279/// 1280/// Ideally, most of this would be done by lookup, but there's 1281/// actually quite a lot of extra work involved. 1282/// 1283/// Returns a null sentinel to indicate trivial success. 1284Sema::OwningExprResult 1285Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1286 IdentifierInfo *II, bool AllowBuiltinCreation) { 1287 SourceLocation Loc = Lookup.getNameLoc(); 1288 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1289 1290 // There are two cases to handle here. 1) scoped lookup could have failed, 1291 // in which case we should look for an ivar. 2) scoped lookup could have 1292 // found a decl, but that decl is outside the current instance method (i.e. 1293 // a global variable). In these two cases, we do a lookup for an ivar with 1294 // this name, if the lookup sucedes, we replace it our current decl. 1295 1296 // If we're in a class method, we don't normally want to look for 1297 // ivars. But if we don't find anything else, and there's an 1298 // ivar, that's an error. 1299 bool IsClassMethod = CurMethod->isClassMethod(); 1300 1301 bool LookForIvars; 1302 if (Lookup.empty()) 1303 LookForIvars = true; 1304 else if (IsClassMethod) 1305 LookForIvars = false; 1306 else 1307 LookForIvars = (Lookup.isSingleResult() && 1308 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1309 ObjCInterfaceDecl *IFace = 0; 1310 if (LookForIvars) { 1311 IFace = CurMethod->getClassInterface(); 1312 ObjCInterfaceDecl *ClassDeclared; 1313 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1314 // Diagnose using an ivar in a class method. 1315 if (IsClassMethod) 1316 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1317 << IV->getDeclName()); 1318 1319 // If we're referencing an invalid decl, just return this as a silent 1320 // error node. The error diagnostic was already emitted on the decl. 1321 if (IV->isInvalidDecl()) 1322 return ExprError(); 1323 1324 // Check if referencing a field with __attribute__((deprecated)). 1325 if (DiagnoseUseOfDecl(IV, Loc)) 1326 return ExprError(); 1327 1328 // Diagnose the use of an ivar outside of the declaring class. 1329 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1330 ClassDeclared != IFace) 1331 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1332 1333 // FIXME: This should use a new expr for a direct reference, don't 1334 // turn this into Self->ivar, just return a BareIVarExpr or something. 1335 IdentifierInfo &II = Context.Idents.get("self"); 1336 UnqualifiedId SelfName; 1337 SelfName.setIdentifier(&II, SourceLocation()); 1338 CXXScopeSpec SelfScopeSpec; 1339 OwningExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1340 SelfName, false, false); 1341 MarkDeclarationReferenced(Loc, IV); 1342 return Owned(new (Context) 1343 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1344 SelfExpr.takeAs<Expr>(), true, true)); 1345 } 1346 } else if (CurMethod->isInstanceMethod()) { 1347 // We should warn if a local variable hides an ivar. 1348 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1349 ObjCInterfaceDecl *ClassDeclared; 1350 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1351 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1352 IFace == ClassDeclared) 1353 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1354 } 1355 } 1356 1357 if (Lookup.empty() && II && AllowBuiltinCreation) { 1358 // FIXME. Consolidate this with similar code in LookupName. 1359 if (unsigned BuiltinID = II->getBuiltinID()) { 1360 if (!(getLangOptions().CPlusPlus && 1361 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1362 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1363 S, Lookup.isForRedeclaration(), 1364 Lookup.getNameLoc()); 1365 if (D) Lookup.addDecl(D); 1366 } 1367 } 1368 } 1369 // Sentinel value saying that we didn't do anything special. 1370 return Owned((Expr*) 0); 1371} 1372 1373/// \brief Cast a base object to a member's actual type. 1374/// 1375/// Logically this happens in three phases: 1376/// 1377/// * First we cast from the base type to the naming class. 1378/// The naming class is the class into which we were looking 1379/// when we found the member; it's the qualifier type if a 1380/// qualifier was provided, and otherwise it's the base type. 1381/// 1382/// * Next we cast from the naming class to the declaring class. 1383/// If the member we found was brought into a class's scope by 1384/// a using declaration, this is that class; otherwise it's 1385/// the class declaring the member. 1386/// 1387/// * Finally we cast from the declaring class to the "true" 1388/// declaring class of the member. This conversion does not 1389/// obey access control. 1390bool 1391Sema::PerformObjectMemberConversion(Expr *&From, 1392 NestedNameSpecifier *Qualifier, 1393 NamedDecl *FoundDecl, 1394 NamedDecl *Member) { 1395 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1396 if (!RD) 1397 return false; 1398 1399 QualType DestRecordType; 1400 QualType DestType; 1401 QualType FromRecordType; 1402 QualType FromType = From->getType(); 1403 bool PointerConversions = false; 1404 if (isa<FieldDecl>(Member)) { 1405 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1406 1407 if (FromType->getAs<PointerType>()) { 1408 DestType = Context.getPointerType(DestRecordType); 1409 FromRecordType = FromType->getPointeeType(); 1410 PointerConversions = true; 1411 } else { 1412 DestType = DestRecordType; 1413 FromRecordType = FromType; 1414 } 1415 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1416 if (Method->isStatic()) 1417 return false; 1418 1419 DestType = Method->getThisType(Context); 1420 DestRecordType = DestType->getPointeeType(); 1421 1422 if (FromType->getAs<PointerType>()) { 1423 FromRecordType = FromType->getPointeeType(); 1424 PointerConversions = true; 1425 } else { 1426 FromRecordType = FromType; 1427 DestType = DestRecordType; 1428 } 1429 } else { 1430 // No conversion necessary. 1431 return false; 1432 } 1433 1434 if (DestType->isDependentType() || FromType->isDependentType()) 1435 return false; 1436 1437 // If the unqualified types are the same, no conversion is necessary. 1438 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1439 return false; 1440 1441 SourceRange FromRange = From->getSourceRange(); 1442 SourceLocation FromLoc = FromRange.getBegin(); 1443 1444 ImplicitCastExpr::ResultCategory Category = CastCategory(From); 1445 1446 // C++ [class.member.lookup]p8: 1447 // [...] Ambiguities can often be resolved by qualifying a name with its 1448 // class name. 1449 // 1450 // If the member was a qualified name and the qualified referred to a 1451 // specific base subobject type, we'll cast to that intermediate type 1452 // first and then to the object in which the member is declared. That allows 1453 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1454 // 1455 // class Base { public: int x; }; 1456 // class Derived1 : public Base { }; 1457 // class Derived2 : public Base { }; 1458 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1459 // 1460 // void VeryDerived::f() { 1461 // x = 17; // error: ambiguous base subobjects 1462 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1463 // } 1464 if (Qualifier) { 1465 QualType QType = QualType(Qualifier->getAsType(), 0); 1466 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1467 assert(QType->isRecordType() && "lookup done with non-record type"); 1468 1469 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1470 1471 // In C++98, the qualifier type doesn't actually have to be a base 1472 // type of the object type, in which case we just ignore it. 1473 // Otherwise build the appropriate casts. 1474 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1475 CXXBaseSpecifierArray BasePath; 1476 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1477 FromLoc, FromRange, &BasePath)) 1478 return true; 1479 1480 if (PointerConversions) 1481 QType = Context.getPointerType(QType); 1482 ImpCastExprToType(From, QType, CastExpr::CK_UncheckedDerivedToBase, 1483 Category, BasePath); 1484 1485 FromType = QType; 1486 FromRecordType = QRecordType; 1487 1488 // If the qualifier type was the same as the destination type, 1489 // we're done. 1490 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1491 return false; 1492 } 1493 } 1494 1495 bool IgnoreAccess = false; 1496 1497 // If we actually found the member through a using declaration, cast 1498 // down to the using declaration's type. 1499 // 1500 // Pointer equality is fine here because only one declaration of a 1501 // class ever has member declarations. 1502 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1503 assert(isa<UsingShadowDecl>(FoundDecl)); 1504 QualType URecordType = Context.getTypeDeclType( 1505 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1506 1507 // We only need to do this if the naming-class to declaring-class 1508 // conversion is non-trivial. 1509 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1510 assert(IsDerivedFrom(FromRecordType, URecordType)); 1511 CXXBaseSpecifierArray BasePath; 1512 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1513 FromLoc, FromRange, &BasePath)) 1514 return true; 1515 1516 QualType UType = URecordType; 1517 if (PointerConversions) 1518 UType = Context.getPointerType(UType); 1519 ImpCastExprToType(From, UType, CastExpr::CK_UncheckedDerivedToBase, 1520 Category, BasePath); 1521 FromType = UType; 1522 FromRecordType = URecordType; 1523 } 1524 1525 // We don't do access control for the conversion from the 1526 // declaring class to the true declaring class. 1527 IgnoreAccess = true; 1528 } 1529 1530 CXXBaseSpecifierArray BasePath; 1531 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1532 FromLoc, FromRange, &BasePath, 1533 IgnoreAccess)) 1534 return true; 1535 1536 ImpCastExprToType(From, DestType, CastExpr::CK_UncheckedDerivedToBase, 1537 Category, BasePath); 1538 return false; 1539} 1540 1541/// \brief Build a MemberExpr AST node. 1542static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1543 const CXXScopeSpec &SS, ValueDecl *Member, 1544 DeclAccessPair FoundDecl, 1545 SourceLocation Loc, QualType Ty, 1546 const TemplateArgumentListInfo *TemplateArgs = 0) { 1547 NestedNameSpecifier *Qualifier = 0; 1548 SourceRange QualifierRange; 1549 if (SS.isSet()) { 1550 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1551 QualifierRange = SS.getRange(); 1552 } 1553 1554 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1555 Member, FoundDecl, Loc, TemplateArgs, Ty); 1556} 1557 1558/// Builds an implicit member access expression. The current context 1559/// is known to be an instance method, and the given unqualified lookup 1560/// set is known to contain only instance members, at least one of which 1561/// is from an appropriate type. 1562Sema::OwningExprResult 1563Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1564 LookupResult &R, 1565 const TemplateArgumentListInfo *TemplateArgs, 1566 bool IsKnownInstance) { 1567 assert(!R.empty() && !R.isAmbiguous()); 1568 1569 SourceLocation Loc = R.getNameLoc(); 1570 1571 // We may have found a field within an anonymous union or struct 1572 // (C++ [class.union]). 1573 // FIXME: This needs to happen post-isImplicitMemberReference? 1574 // FIXME: template-ids inside anonymous structs? 1575 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1576 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1577 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1578 1579 // If this is known to be an instance access, go ahead and build a 1580 // 'this' expression now. 1581 DeclContext *DC = getFunctionLevelDeclContext(); 1582 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 1583 Expr *This = 0; // null signifies implicit access 1584 if (IsKnownInstance) { 1585 SourceLocation Loc = R.getNameLoc(); 1586 if (SS.getRange().isValid()) 1587 Loc = SS.getRange().getBegin(); 1588 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1589 } 1590 1591 return BuildMemberReferenceExpr(ExprArg(*this, This), ThisType, 1592 /*OpLoc*/ SourceLocation(), 1593 /*IsArrow*/ true, 1594 SS, 1595 /*FirstQualifierInScope*/ 0, 1596 R, TemplateArgs); 1597} 1598 1599bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1600 const LookupResult &R, 1601 bool HasTrailingLParen) { 1602 // Only when used directly as the postfix-expression of a call. 1603 if (!HasTrailingLParen) 1604 return false; 1605 1606 // Never if a scope specifier was provided. 1607 if (SS.isSet()) 1608 return false; 1609 1610 // Only in C++ or ObjC++. 1611 if (!getLangOptions().CPlusPlus) 1612 return false; 1613 1614 // Turn off ADL when we find certain kinds of declarations during 1615 // normal lookup: 1616 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1617 NamedDecl *D = *I; 1618 1619 // C++0x [basic.lookup.argdep]p3: 1620 // -- a declaration of a class member 1621 // Since using decls preserve this property, we check this on the 1622 // original decl. 1623 if (D->isCXXClassMember()) 1624 return false; 1625 1626 // C++0x [basic.lookup.argdep]p3: 1627 // -- a block-scope function declaration that is not a 1628 // using-declaration 1629 // NOTE: we also trigger this for function templates (in fact, we 1630 // don't check the decl type at all, since all other decl types 1631 // turn off ADL anyway). 1632 if (isa<UsingShadowDecl>(D)) 1633 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1634 else if (D->getDeclContext()->isFunctionOrMethod()) 1635 return false; 1636 1637 // C++0x [basic.lookup.argdep]p3: 1638 // -- a declaration that is neither a function or a function 1639 // template 1640 // And also for builtin functions. 1641 if (isa<FunctionDecl>(D)) { 1642 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1643 1644 // But also builtin functions. 1645 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1646 return false; 1647 } else if (!isa<FunctionTemplateDecl>(D)) 1648 return false; 1649 } 1650 1651 return true; 1652} 1653 1654 1655/// Diagnoses obvious problems with the use of the given declaration 1656/// as an expression. This is only actually called for lookups that 1657/// were not overloaded, and it doesn't promise that the declaration 1658/// will in fact be used. 1659static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1660 if (isa<TypedefDecl>(D)) { 1661 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1662 return true; 1663 } 1664 1665 if (isa<ObjCInterfaceDecl>(D)) { 1666 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1667 return true; 1668 } 1669 1670 if (isa<NamespaceDecl>(D)) { 1671 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1672 return true; 1673 } 1674 1675 return false; 1676} 1677 1678Sema::OwningExprResult 1679Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1680 LookupResult &R, 1681 bool NeedsADL) { 1682 // If this is a single, fully-resolved result and we don't need ADL, 1683 // just build an ordinary singleton decl ref. 1684 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1685 return BuildDeclarationNameExpr(SS, R.getNameLoc(), R.getFoundDecl()); 1686 1687 // We only need to check the declaration if there's exactly one 1688 // result, because in the overloaded case the results can only be 1689 // functions and function templates. 1690 if (R.isSingleResult() && 1691 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1692 return ExprError(); 1693 1694 // Otherwise, just build an unresolved lookup expression. Suppress 1695 // any lookup-related diagnostics; we'll hash these out later, when 1696 // we've picked a target. 1697 R.suppressDiagnostics(); 1698 1699 bool Dependent 1700 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1701 UnresolvedLookupExpr *ULE 1702 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1703 (NestedNameSpecifier*) SS.getScopeRep(), 1704 SS.getRange(), 1705 R.getLookupName(), R.getNameLoc(), 1706 NeedsADL, R.isOverloadedResult(), 1707 R.begin(), R.end()); 1708 1709 return Owned(ULE); 1710} 1711 1712 1713/// \brief Complete semantic analysis for a reference to the given declaration. 1714Sema::OwningExprResult 1715Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1716 SourceLocation Loc, NamedDecl *D) { 1717 assert(D && "Cannot refer to a NULL declaration"); 1718 assert(!isa<FunctionTemplateDecl>(D) && 1719 "Cannot refer unambiguously to a function template"); 1720 1721 if (CheckDeclInExpr(*this, Loc, D)) 1722 return ExprError(); 1723 1724 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1725 // Specifically diagnose references to class templates that are missing 1726 // a template argument list. 1727 Diag(Loc, diag::err_template_decl_ref) 1728 << Template << SS.getRange(); 1729 Diag(Template->getLocation(), diag::note_template_decl_here); 1730 return ExprError(); 1731 } 1732 1733 // Make sure that we're referring to a value. 1734 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1735 if (!VD) { 1736 Diag(Loc, diag::err_ref_non_value) 1737 << D << SS.getRange(); 1738 Diag(D->getLocation(), diag::note_declared_at); 1739 return ExprError(); 1740 } 1741 1742 // Check whether this declaration can be used. Note that we suppress 1743 // this check when we're going to perform argument-dependent lookup 1744 // on this function name, because this might not be the function 1745 // that overload resolution actually selects. 1746 if (DiagnoseUseOfDecl(VD, Loc)) 1747 return ExprError(); 1748 1749 // Only create DeclRefExpr's for valid Decl's. 1750 if (VD->isInvalidDecl()) 1751 return ExprError(); 1752 1753 // If the identifier reference is inside a block, and it refers to a value 1754 // that is outside the block, create a BlockDeclRefExpr instead of a 1755 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1756 // the block is formed. 1757 // 1758 // We do not do this for things like enum constants, global variables, etc, 1759 // as they do not get snapshotted. 1760 // 1761 if (getCurBlock() && 1762 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1763 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1764 Diag(Loc, diag::err_ref_vm_type); 1765 Diag(D->getLocation(), diag::note_declared_at); 1766 return ExprError(); 1767 } 1768 1769 if (VD->getType()->isArrayType()) { 1770 Diag(Loc, diag::err_ref_array_type); 1771 Diag(D->getLocation(), diag::note_declared_at); 1772 return ExprError(); 1773 } 1774 1775 MarkDeclarationReferenced(Loc, VD); 1776 QualType ExprTy = VD->getType().getNonReferenceType(); 1777 // The BlocksAttr indicates the variable is bound by-reference. 1778 if (VD->getAttr<BlocksAttr>()) 1779 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1780 // This is to record that a 'const' was actually synthesize and added. 1781 bool constAdded = !ExprTy.isConstQualified(); 1782 // Variable will be bound by-copy, make it const within the closure. 1783 1784 ExprTy.addConst(); 1785 QualType T = VD->getType(); 1786 BlockDeclRefExpr *BDRE = new (Context) BlockDeclRefExpr(VD, 1787 ExprTy, Loc, false, 1788 constAdded); 1789 if (getLangOptions().CPlusPlus) { 1790 if (!T->isDependentType() && !T->isReferenceType()) { 1791 Expr *E = new (Context) 1792 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 1793 SourceLocation()); 1794 1795 OwningExprResult Res = PerformCopyInitialization( 1796 InitializedEntity::InitializeBlock(VD->getLocation(), 1797 T, false), 1798 SourceLocation(), 1799 Owned(E)); 1800 if (!Res.isInvalid()) { 1801 Res = MaybeCreateCXXExprWithTemporaries(move(Res)); 1802 Expr *Init = Res.takeAs<Expr>(); 1803 BDRE->setCopyConstructorExpr(Init); 1804 } 1805 } 1806 } 1807 return Owned(BDRE); 1808 } 1809 // If this reference is not in a block or if the referenced variable is 1810 // within the block, create a normal DeclRefExpr. 1811 1812 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), Loc, &SS); 1813} 1814 1815Sema::OwningExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1816 tok::TokenKind Kind) { 1817 PredefinedExpr::IdentType IT; 1818 1819 switch (Kind) { 1820 default: assert(0 && "Unknown simple primary expr!"); 1821 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1822 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1823 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1824 } 1825 1826 // Pre-defined identifiers are of type char[x], where x is the length of the 1827 // string. 1828 1829 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1830 if (!currentDecl) { 1831 Diag(Loc, diag::ext_predef_outside_function); 1832 currentDecl = Context.getTranslationUnitDecl(); 1833 } 1834 1835 QualType ResTy; 1836 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1837 ResTy = Context.DependentTy; 1838 } else { 1839 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1840 1841 llvm::APInt LengthI(32, Length + 1); 1842 ResTy = Context.CharTy.withConst(); 1843 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1844 } 1845 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1846} 1847 1848Sema::OwningExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1849 llvm::SmallString<16> CharBuffer; 1850 bool Invalid = false; 1851 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1852 if (Invalid) 1853 return ExprError(); 1854 1855 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1856 PP); 1857 if (Literal.hadError()) 1858 return ExprError(); 1859 1860 QualType Ty; 1861 if (!getLangOptions().CPlusPlus) 1862 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1863 else if (Literal.isWide()) 1864 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1865 else if (Literal.isMultiChar()) 1866 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1867 else 1868 Ty = Context.CharTy; // 'x' -> char in C++ 1869 1870 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1871 Literal.isWide(), 1872 Ty, Tok.getLocation())); 1873} 1874 1875Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1876 // Fast path for a single digit (which is quite common). A single digit 1877 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1878 if (Tok.getLength() == 1) { 1879 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1880 unsigned IntSize = Context.Target.getIntWidth(); 1881 return Owned(new (Context) IntegerLiteral(llvm::APInt(IntSize, Val-'0'), 1882 Context.IntTy, Tok.getLocation())); 1883 } 1884 1885 llvm::SmallString<512> IntegerBuffer; 1886 // Add padding so that NumericLiteralParser can overread by one character. 1887 IntegerBuffer.resize(Tok.getLength()+1); 1888 const char *ThisTokBegin = &IntegerBuffer[0]; 1889 1890 // Get the spelling of the token, which eliminates trigraphs, etc. 1891 bool Invalid = false; 1892 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1893 if (Invalid) 1894 return ExprError(); 1895 1896 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1897 Tok.getLocation(), PP); 1898 if (Literal.hadError) 1899 return ExprError(); 1900 1901 Expr *Res; 1902 1903 if (Literal.isFloatingLiteral()) { 1904 QualType Ty; 1905 if (Literal.isFloat) 1906 Ty = Context.FloatTy; 1907 else if (!Literal.isLong) 1908 Ty = Context.DoubleTy; 1909 else 1910 Ty = Context.LongDoubleTy; 1911 1912 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1913 1914 using llvm::APFloat; 1915 APFloat Val(Format); 1916 1917 APFloat::opStatus result = Literal.GetFloatValue(Val); 1918 1919 // Overflow is always an error, but underflow is only an error if 1920 // we underflowed to zero (APFloat reports denormals as underflow). 1921 if ((result & APFloat::opOverflow) || 1922 ((result & APFloat::opUnderflow) && Val.isZero())) { 1923 unsigned diagnostic; 1924 llvm::SmallString<20> buffer; 1925 if (result & APFloat::opOverflow) { 1926 diagnostic = diag::warn_float_overflow; 1927 APFloat::getLargest(Format).toString(buffer); 1928 } else { 1929 diagnostic = diag::warn_float_underflow; 1930 APFloat::getSmallest(Format).toString(buffer); 1931 } 1932 1933 Diag(Tok.getLocation(), diagnostic) 1934 << Ty 1935 << llvm::StringRef(buffer.data(), buffer.size()); 1936 } 1937 1938 bool isExact = (result == APFloat::opOK); 1939 Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation()); 1940 1941 } else if (!Literal.isIntegerLiteral()) { 1942 return ExprError(); 1943 } else { 1944 QualType Ty; 1945 1946 // long long is a C99 feature. 1947 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 1948 Literal.isLongLong) 1949 Diag(Tok.getLocation(), diag::ext_longlong); 1950 1951 // Get the value in the widest-possible width. 1952 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 1953 1954 if (Literal.GetIntegerValue(ResultVal)) { 1955 // If this value didn't fit into uintmax_t, warn and force to ull. 1956 Diag(Tok.getLocation(), diag::warn_integer_too_large); 1957 Ty = Context.UnsignedLongLongTy; 1958 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 1959 "long long is not intmax_t?"); 1960 } else { 1961 // If this value fits into a ULL, try to figure out what else it fits into 1962 // according to the rules of C99 6.4.4.1p5. 1963 1964 // Octal, Hexadecimal, and integers with a U suffix are allowed to 1965 // be an unsigned int. 1966 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 1967 1968 // Check from smallest to largest, picking the smallest type we can. 1969 unsigned Width = 0; 1970 if (!Literal.isLong && !Literal.isLongLong) { 1971 // Are int/unsigned possibilities? 1972 unsigned IntSize = Context.Target.getIntWidth(); 1973 1974 // Does it fit in a unsigned int? 1975 if (ResultVal.isIntN(IntSize)) { 1976 // Does it fit in a signed int? 1977 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 1978 Ty = Context.IntTy; 1979 else if (AllowUnsigned) 1980 Ty = Context.UnsignedIntTy; 1981 Width = IntSize; 1982 } 1983 } 1984 1985 // Are long/unsigned long possibilities? 1986 if (Ty.isNull() && !Literal.isLongLong) { 1987 unsigned LongSize = Context.Target.getLongWidth(); 1988 1989 // Does it fit in a unsigned long? 1990 if (ResultVal.isIntN(LongSize)) { 1991 // Does it fit in a signed long? 1992 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 1993 Ty = Context.LongTy; 1994 else if (AllowUnsigned) 1995 Ty = Context.UnsignedLongTy; 1996 Width = LongSize; 1997 } 1998 } 1999 2000 // Finally, check long long if needed. 2001 if (Ty.isNull()) { 2002 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2003 2004 // Does it fit in a unsigned long long? 2005 if (ResultVal.isIntN(LongLongSize)) { 2006 // Does it fit in a signed long long? 2007 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 2008 Ty = Context.LongLongTy; 2009 else if (AllowUnsigned) 2010 Ty = Context.UnsignedLongLongTy; 2011 Width = LongLongSize; 2012 } 2013 } 2014 2015 // If we still couldn't decide a type, we probably have something that 2016 // does not fit in a signed long long, but has no U suffix. 2017 if (Ty.isNull()) { 2018 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2019 Ty = Context.UnsignedLongLongTy; 2020 Width = Context.Target.getLongLongWidth(); 2021 } 2022 2023 if (ResultVal.getBitWidth() != Width) 2024 ResultVal.trunc(Width); 2025 } 2026 Res = new (Context) IntegerLiteral(ResultVal, Ty, Tok.getLocation()); 2027 } 2028 2029 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2030 if (Literal.isImaginary) 2031 Res = new (Context) ImaginaryLiteral(Res, 2032 Context.getComplexType(Res->getType())); 2033 2034 return Owned(Res); 2035} 2036 2037Action::OwningExprResult Sema::ActOnParenExpr(SourceLocation L, 2038 SourceLocation R, ExprArg Val) { 2039 Expr *E = Val.takeAs<Expr>(); 2040 assert((E != 0) && "ActOnParenExpr() missing expr"); 2041 return Owned(new (Context) ParenExpr(L, R, E)); 2042} 2043 2044/// The UsualUnaryConversions() function is *not* called by this routine. 2045/// See C99 6.3.2.1p[2-4] for more details. 2046bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2047 SourceLocation OpLoc, 2048 const SourceRange &ExprRange, 2049 bool isSizeof) { 2050 if (exprType->isDependentType()) 2051 return false; 2052 2053 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2054 // the result is the size of the referenced type." 2055 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2056 // result shall be the alignment of the referenced type." 2057 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2058 exprType = Ref->getPointeeType(); 2059 2060 // C99 6.5.3.4p1: 2061 if (exprType->isFunctionType()) { 2062 // alignof(function) is allowed as an extension. 2063 if (isSizeof) 2064 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2065 return false; 2066 } 2067 2068 // Allow sizeof(void)/alignof(void) as an extension. 2069 if (exprType->isVoidType()) { 2070 Diag(OpLoc, diag::ext_sizeof_void_type) 2071 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2072 return false; 2073 } 2074 2075 if (RequireCompleteType(OpLoc, exprType, 2076 PDiag(diag::err_sizeof_alignof_incomplete_type) 2077 << int(!isSizeof) << ExprRange)) 2078 return true; 2079 2080 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2081 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2082 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2083 << exprType << isSizeof << ExprRange; 2084 return true; 2085 } 2086 2087 if (Context.hasSameUnqualifiedType(exprType, Context.OverloadTy)) { 2088 Diag(OpLoc, diag::err_sizeof_alignof_overloaded_function_type) 2089 << !isSizeof << ExprRange; 2090 return true; 2091 } 2092 2093 return false; 2094} 2095 2096bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2097 const SourceRange &ExprRange) { 2098 E = E->IgnoreParens(); 2099 2100 // alignof decl is always ok. 2101 if (isa<DeclRefExpr>(E)) 2102 return false; 2103 2104 // Cannot know anything else if the expression is dependent. 2105 if (E->isTypeDependent()) 2106 return false; 2107 2108 if (E->getBitField()) { 2109 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2110 return true; 2111 } 2112 2113 // Alignment of a field access is always okay, so long as it isn't a 2114 // bit-field. 2115 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2116 if (isa<FieldDecl>(ME->getMemberDecl())) 2117 return false; 2118 2119 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2120} 2121 2122/// \brief Build a sizeof or alignof expression given a type operand. 2123Action::OwningExprResult 2124Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2125 SourceLocation OpLoc, 2126 bool isSizeOf, SourceRange R) { 2127 if (!TInfo) 2128 return ExprError(); 2129 2130 QualType T = TInfo->getType(); 2131 2132 if (!T->isDependentType() && 2133 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2134 return ExprError(); 2135 2136 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2137 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2138 Context.getSizeType(), OpLoc, 2139 R.getEnd())); 2140} 2141 2142/// \brief Build a sizeof or alignof expression given an expression 2143/// operand. 2144Action::OwningExprResult 2145Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2146 bool isSizeOf, SourceRange R) { 2147 // Verify that the operand is valid. 2148 bool isInvalid = false; 2149 if (E->isTypeDependent()) { 2150 // Delay type-checking for type-dependent expressions. 2151 } else if (!isSizeOf) { 2152 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2153 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2154 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2155 isInvalid = true; 2156 } else { 2157 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2158 } 2159 2160 if (isInvalid) 2161 return ExprError(); 2162 2163 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2164 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2165 Context.getSizeType(), OpLoc, 2166 R.getEnd())); 2167} 2168 2169/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2170/// the same for @c alignof and @c __alignof 2171/// Note that the ArgRange is invalid if isType is false. 2172Action::OwningExprResult 2173Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2174 void *TyOrEx, const SourceRange &ArgRange) { 2175 // If error parsing type, ignore. 2176 if (TyOrEx == 0) return ExprError(); 2177 2178 if (isType) { 2179 TypeSourceInfo *TInfo; 2180 (void) GetTypeFromParser(TyOrEx, &TInfo); 2181 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2182 } 2183 2184 Expr *ArgEx = (Expr *)TyOrEx; 2185 Action::OwningExprResult Result 2186 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2187 2188 if (Result.isInvalid()) 2189 DeleteExpr(ArgEx); 2190 2191 return move(Result); 2192} 2193 2194QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2195 if (V->isTypeDependent()) 2196 return Context.DependentTy; 2197 2198 // These operators return the element type of a complex type. 2199 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2200 return CT->getElementType(); 2201 2202 // Otherwise they pass through real integer and floating point types here. 2203 if (V->getType()->isArithmeticType()) 2204 return V->getType(); 2205 2206 // Reject anything else. 2207 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2208 << (isReal ? "__real" : "__imag"); 2209 return QualType(); 2210} 2211 2212 2213 2214Action::OwningExprResult 2215Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2216 tok::TokenKind Kind, ExprArg Input) { 2217 UnaryOperator::Opcode Opc; 2218 switch (Kind) { 2219 default: assert(0 && "Unknown unary op!"); 2220 case tok::plusplus: Opc = UnaryOperator::PostInc; break; 2221 case tok::minusminus: Opc = UnaryOperator::PostDec; break; 2222 } 2223 2224 return BuildUnaryOp(S, OpLoc, Opc, move(Input)); 2225} 2226 2227Action::OwningExprResult 2228Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc, 2229 ExprArg Idx, SourceLocation RLoc) { 2230 // Since this might be a postfix expression, get rid of ParenListExprs. 2231 Base = MaybeConvertParenListExprToParenExpr(S, move(Base)); 2232 2233 Expr *LHSExp = static_cast<Expr*>(Base.get()), 2234 *RHSExp = static_cast<Expr*>(Idx.get()); 2235 2236 if (getLangOptions().CPlusPlus && 2237 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2238 Base.release(); 2239 Idx.release(); 2240 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2241 Context.DependentTy, RLoc)); 2242 } 2243 2244 if (getLangOptions().CPlusPlus && 2245 (LHSExp->getType()->isRecordType() || 2246 LHSExp->getType()->isEnumeralType() || 2247 RHSExp->getType()->isRecordType() || 2248 RHSExp->getType()->isEnumeralType())) { 2249 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, move(Base),move(Idx)); 2250 } 2251 2252 return CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 2253} 2254 2255 2256Action::OwningExprResult 2257Sema::CreateBuiltinArraySubscriptExpr(ExprArg Base, SourceLocation LLoc, 2258 ExprArg Idx, SourceLocation RLoc) { 2259 Expr *LHSExp = static_cast<Expr*>(Base.get()); 2260 Expr *RHSExp = static_cast<Expr*>(Idx.get()); 2261 2262 // Perform default conversions. 2263 if (!LHSExp->getType()->getAs<VectorType>()) 2264 DefaultFunctionArrayLvalueConversion(LHSExp); 2265 DefaultFunctionArrayLvalueConversion(RHSExp); 2266 2267 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2268 2269 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2270 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2271 // in the subscript position. As a result, we need to derive the array base 2272 // and index from the expression types. 2273 Expr *BaseExpr, *IndexExpr; 2274 QualType ResultType; 2275 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2276 BaseExpr = LHSExp; 2277 IndexExpr = RHSExp; 2278 ResultType = Context.DependentTy; 2279 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2280 BaseExpr = LHSExp; 2281 IndexExpr = RHSExp; 2282 ResultType = PTy->getPointeeType(); 2283 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2284 // Handle the uncommon case of "123[Ptr]". 2285 BaseExpr = RHSExp; 2286 IndexExpr = LHSExp; 2287 ResultType = PTy->getPointeeType(); 2288 } else if (const ObjCObjectPointerType *PTy = 2289 LHSTy->getAs<ObjCObjectPointerType>()) { 2290 BaseExpr = LHSExp; 2291 IndexExpr = RHSExp; 2292 ResultType = PTy->getPointeeType(); 2293 } else if (const ObjCObjectPointerType *PTy = 2294 RHSTy->getAs<ObjCObjectPointerType>()) { 2295 // Handle the uncommon case of "123[Ptr]". 2296 BaseExpr = RHSExp; 2297 IndexExpr = LHSExp; 2298 ResultType = PTy->getPointeeType(); 2299 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2300 BaseExpr = LHSExp; // vectors: V[123] 2301 IndexExpr = RHSExp; 2302 2303 // FIXME: need to deal with const... 2304 ResultType = VTy->getElementType(); 2305 } else if (LHSTy->isArrayType()) { 2306 // If we see an array that wasn't promoted by 2307 // DefaultFunctionArrayLvalueConversion, it must be an array that 2308 // wasn't promoted because of the C90 rule that doesn't 2309 // allow promoting non-lvalue arrays. Warn, then 2310 // force the promotion here. 2311 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2312 LHSExp->getSourceRange(); 2313 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2314 CastExpr::CK_ArrayToPointerDecay); 2315 LHSTy = LHSExp->getType(); 2316 2317 BaseExpr = LHSExp; 2318 IndexExpr = RHSExp; 2319 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2320 } else if (RHSTy->isArrayType()) { 2321 // Same as previous, except for 123[f().a] case 2322 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2323 RHSExp->getSourceRange(); 2324 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2325 CastExpr::CK_ArrayToPointerDecay); 2326 RHSTy = RHSExp->getType(); 2327 2328 BaseExpr = RHSExp; 2329 IndexExpr = LHSExp; 2330 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2331 } else { 2332 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2333 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2334 } 2335 // C99 6.5.2.1p1 2336 if (!(IndexExpr->getType()->isIntegerType() && 2337 IndexExpr->getType()->isScalarType()) && !IndexExpr->isTypeDependent()) 2338 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2339 << IndexExpr->getSourceRange()); 2340 2341 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2342 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2343 && !IndexExpr->isTypeDependent()) 2344 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2345 2346 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2347 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2348 // type. Note that Functions are not objects, and that (in C99 parlance) 2349 // incomplete types are not object types. 2350 if (ResultType->isFunctionType()) { 2351 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2352 << ResultType << BaseExpr->getSourceRange(); 2353 return ExprError(); 2354 } 2355 2356 if (!ResultType->isDependentType() && 2357 RequireCompleteType(LLoc, ResultType, 2358 PDiag(diag::err_subscript_incomplete_type) 2359 << BaseExpr->getSourceRange())) 2360 return ExprError(); 2361 2362 // Diagnose bad cases where we step over interface counts. 2363 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2364 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2365 << ResultType << BaseExpr->getSourceRange(); 2366 return ExprError(); 2367 } 2368 2369 Base.release(); 2370 Idx.release(); 2371 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2372 ResultType, RLoc)); 2373} 2374 2375QualType Sema:: 2376CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2377 const IdentifierInfo *CompName, 2378 SourceLocation CompLoc) { 2379 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2380 // see FIXME there. 2381 // 2382 // FIXME: This logic can be greatly simplified by splitting it along 2383 // halving/not halving and reworking the component checking. 2384 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2385 2386 // The vector accessor can't exceed the number of elements. 2387 const char *compStr = CompName->getNameStart(); 2388 2389 // This flag determines whether or not the component is one of the four 2390 // special names that indicate a subset of exactly half the elements are 2391 // to be selected. 2392 bool HalvingSwizzle = false; 2393 2394 // This flag determines whether or not CompName has an 's' char prefix, 2395 // indicating that it is a string of hex values to be used as vector indices. 2396 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2397 2398 // Check that we've found one of the special components, or that the component 2399 // names must come from the same set. 2400 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2401 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2402 HalvingSwizzle = true; 2403 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2404 do 2405 compStr++; 2406 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2407 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2408 do 2409 compStr++; 2410 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2411 } 2412 2413 if (!HalvingSwizzle && *compStr) { 2414 // We didn't get to the end of the string. This means the component names 2415 // didn't come from the same set *or* we encountered an illegal name. 2416 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2417 << std::string(compStr,compStr+1) << SourceRange(CompLoc); 2418 return QualType(); 2419 } 2420 2421 // Ensure no component accessor exceeds the width of the vector type it 2422 // operates on. 2423 if (!HalvingSwizzle) { 2424 compStr = CompName->getNameStart(); 2425 2426 if (HexSwizzle) 2427 compStr++; 2428 2429 while (*compStr) { 2430 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2431 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2432 << baseType << SourceRange(CompLoc); 2433 return QualType(); 2434 } 2435 } 2436 } 2437 2438 // The component accessor looks fine - now we need to compute the actual type. 2439 // The vector type is implied by the component accessor. For example, 2440 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2441 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2442 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2443 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2444 : CompName->getLength(); 2445 if (HexSwizzle) 2446 CompSize--; 2447 2448 if (CompSize == 1) 2449 return vecType->getElementType(); 2450 2451 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2452 // Now look up the TypeDefDecl from the vector type. Without this, 2453 // diagostics look bad. We want extended vector types to appear built-in. 2454 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2455 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2456 return Context.getTypedefType(ExtVectorDecls[i]); 2457 } 2458 return VT; // should never get here (a typedef type should always be found). 2459} 2460 2461static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2462 IdentifierInfo *Member, 2463 const Selector &Sel, 2464 ASTContext &Context) { 2465 2466 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2467 return PD; 2468 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2469 return OMD; 2470 2471 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2472 E = PDecl->protocol_end(); I != E; ++I) { 2473 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2474 Context)) 2475 return D; 2476 } 2477 return 0; 2478} 2479 2480static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2481 IdentifierInfo *Member, 2482 const Selector &Sel, 2483 ASTContext &Context) { 2484 // Check protocols on qualified interfaces. 2485 Decl *GDecl = 0; 2486 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2487 E = QIdTy->qual_end(); I != E; ++I) { 2488 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2489 GDecl = PD; 2490 break; 2491 } 2492 // Also must look for a getter name which uses property syntax. 2493 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2494 GDecl = OMD; 2495 break; 2496 } 2497 } 2498 if (!GDecl) { 2499 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2500 E = QIdTy->qual_end(); I != E; ++I) { 2501 // Search in the protocol-qualifier list of current protocol. 2502 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2503 if (GDecl) 2504 return GDecl; 2505 } 2506 } 2507 return GDecl; 2508} 2509 2510Sema::OwningExprResult 2511Sema::ActOnDependentMemberExpr(ExprArg Base, QualType BaseType, 2512 bool IsArrow, SourceLocation OpLoc, 2513 const CXXScopeSpec &SS, 2514 NamedDecl *FirstQualifierInScope, 2515 DeclarationName Name, SourceLocation NameLoc, 2516 const TemplateArgumentListInfo *TemplateArgs) { 2517 Expr *BaseExpr = Base.takeAs<Expr>(); 2518 2519 // Even in dependent contexts, try to diagnose base expressions with 2520 // obviously wrong types, e.g.: 2521 // 2522 // T* t; 2523 // t.f; 2524 // 2525 // In Obj-C++, however, the above expression is valid, since it could be 2526 // accessing the 'f' property if T is an Obj-C interface. The extra check 2527 // allows this, while still reporting an error if T is a struct pointer. 2528 if (!IsArrow) { 2529 const PointerType *PT = BaseType->getAs<PointerType>(); 2530 if (PT && (!getLangOptions().ObjC1 || 2531 PT->getPointeeType()->isRecordType())) { 2532 assert(BaseExpr && "cannot happen with implicit member accesses"); 2533 Diag(NameLoc, diag::err_typecheck_member_reference_struct_union) 2534 << BaseType << BaseExpr->getSourceRange(); 2535 return ExprError(); 2536 } 2537 } 2538 2539 assert(BaseType->isDependentType() || Name.isDependentName() || 2540 isDependentScopeSpecifier(SS)); 2541 2542 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2543 // must have pointer type, and the accessed type is the pointee. 2544 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2545 IsArrow, OpLoc, 2546 static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 2547 SS.getRange(), 2548 FirstQualifierInScope, 2549 Name, NameLoc, 2550 TemplateArgs)); 2551} 2552 2553/// We know that the given qualified member reference points only to 2554/// declarations which do not belong to the static type of the base 2555/// expression. Diagnose the problem. 2556static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2557 Expr *BaseExpr, 2558 QualType BaseType, 2559 const CXXScopeSpec &SS, 2560 const LookupResult &R) { 2561 // If this is an implicit member access, use a different set of 2562 // diagnostics. 2563 if (!BaseExpr) 2564 return DiagnoseInstanceReference(SemaRef, SS, R); 2565 2566 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 2567 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 2568} 2569 2570// Check whether the declarations we found through a nested-name 2571// specifier in a member expression are actually members of the base 2572// type. The restriction here is: 2573// 2574// C++ [expr.ref]p2: 2575// ... In these cases, the id-expression shall name a 2576// member of the class or of one of its base classes. 2577// 2578// So it's perfectly legitimate for the nested-name specifier to name 2579// an unrelated class, and for us to find an overload set including 2580// decls from classes which are not superclasses, as long as the decl 2581// we actually pick through overload resolution is from a superclass. 2582bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2583 QualType BaseType, 2584 const CXXScopeSpec &SS, 2585 const LookupResult &R) { 2586 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2587 if (!BaseRT) { 2588 // We can't check this yet because the base type is still 2589 // dependent. 2590 assert(BaseType->isDependentType()); 2591 return false; 2592 } 2593 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2594 2595 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2596 // If this is an implicit member reference and we find a 2597 // non-instance member, it's not an error. 2598 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2599 return false; 2600 2601 // Note that we use the DC of the decl, not the underlying decl. 2602 CXXRecordDecl *RecordD = cast<CXXRecordDecl>((*I)->getDeclContext()); 2603 while (RecordD->isAnonymousStructOrUnion()) 2604 RecordD = cast<CXXRecordDecl>(RecordD->getParent()); 2605 2606 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2607 MemberRecord.insert(RecordD->getCanonicalDecl()); 2608 2609 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2610 return false; 2611 } 2612 2613 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2614 return true; 2615} 2616 2617static bool 2618LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2619 SourceRange BaseRange, const RecordType *RTy, 2620 SourceLocation OpLoc, CXXScopeSpec &SS, 2621 bool HasTemplateArgs) { 2622 RecordDecl *RDecl = RTy->getDecl(); 2623 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2624 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2625 << BaseRange)) 2626 return true; 2627 2628 if (HasTemplateArgs) { 2629 // LookupTemplateName doesn't expect these both to exist simultaneously. 2630 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 2631 2632 bool MOUS; 2633 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 2634 return false; 2635 } 2636 2637 DeclContext *DC = RDecl; 2638 if (SS.isSet()) { 2639 // If the member name was a qualified-id, look into the 2640 // nested-name-specifier. 2641 DC = SemaRef.computeDeclContext(SS, false); 2642 2643 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 2644 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2645 << SS.getRange() << DC; 2646 return true; 2647 } 2648 2649 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2650 2651 if (!isa<TypeDecl>(DC)) { 2652 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2653 << DC << SS.getRange(); 2654 return true; 2655 } 2656 } 2657 2658 // The record definition is complete, now look up the member. 2659 SemaRef.LookupQualifiedName(R, DC); 2660 2661 if (!R.empty()) 2662 return false; 2663 2664 // We didn't find anything with the given name, so try to correct 2665 // for typos. 2666 DeclarationName Name = R.getLookupName(); 2667 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 2668 !R.empty() && 2669 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2670 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2671 << Name << DC << R.getLookupName() << SS.getRange() 2672 << FixItHint::CreateReplacement(R.getNameLoc(), 2673 R.getLookupName().getAsString()); 2674 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2675 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2676 << ND->getDeclName(); 2677 return false; 2678 } else { 2679 R.clear(); 2680 R.setLookupName(Name); 2681 } 2682 2683 return false; 2684} 2685 2686Sema::OwningExprResult 2687Sema::BuildMemberReferenceExpr(ExprArg BaseArg, QualType BaseType, 2688 SourceLocation OpLoc, bool IsArrow, 2689 CXXScopeSpec &SS, 2690 NamedDecl *FirstQualifierInScope, 2691 DeclarationName Name, SourceLocation NameLoc, 2692 const TemplateArgumentListInfo *TemplateArgs) { 2693 Expr *Base = BaseArg.takeAs<Expr>(); 2694 2695 if (BaseType->isDependentType() || 2696 (SS.isSet() && isDependentScopeSpecifier(SS))) 2697 return ActOnDependentMemberExpr(ExprArg(*this, Base), BaseType, 2698 IsArrow, OpLoc, 2699 SS, FirstQualifierInScope, 2700 Name, NameLoc, 2701 TemplateArgs); 2702 2703 LookupResult R(*this, Name, NameLoc, LookupMemberName); 2704 2705 // Implicit member accesses. 2706 if (!Base) { 2707 QualType RecordTy = BaseType; 2708 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2709 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2710 RecordTy->getAs<RecordType>(), 2711 OpLoc, SS, TemplateArgs != 0)) 2712 return ExprError(); 2713 2714 // Explicit member accesses. 2715 } else { 2716 OwningExprResult Result = 2717 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2718 SS, /*ObjCImpDecl*/ DeclPtrTy(), TemplateArgs != 0); 2719 2720 if (Result.isInvalid()) { 2721 Owned(Base); 2722 return ExprError(); 2723 } 2724 2725 if (Result.get()) 2726 return move(Result); 2727 2728 // LookupMemberExpr can modify Base, and thus change BaseType 2729 BaseType = Base->getType(); 2730 } 2731 2732 return BuildMemberReferenceExpr(ExprArg(*this, Base), BaseType, 2733 OpLoc, IsArrow, SS, FirstQualifierInScope, 2734 R, TemplateArgs); 2735} 2736 2737Sema::OwningExprResult 2738Sema::BuildMemberReferenceExpr(ExprArg Base, QualType BaseExprType, 2739 SourceLocation OpLoc, bool IsArrow, 2740 const CXXScopeSpec &SS, 2741 NamedDecl *FirstQualifierInScope, 2742 LookupResult &R, 2743 const TemplateArgumentListInfo *TemplateArgs, 2744 bool SuppressQualifierCheck) { 2745 Expr *BaseExpr = Base.takeAs<Expr>(); 2746 QualType BaseType = BaseExprType; 2747 if (IsArrow) { 2748 assert(BaseType->isPointerType()); 2749 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2750 } 2751 R.setBaseObjectType(BaseType); 2752 2753 NestedNameSpecifier *Qualifier = 2754 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 2755 DeclarationName MemberName = R.getLookupName(); 2756 SourceLocation MemberLoc = R.getNameLoc(); 2757 2758 if (R.isAmbiguous()) 2759 return ExprError(); 2760 2761 if (R.empty()) { 2762 // Rederive where we looked up. 2763 DeclContext *DC = (SS.isSet() 2764 ? computeDeclContext(SS, false) 2765 : BaseType->getAs<RecordType>()->getDecl()); 2766 2767 Diag(R.getNameLoc(), diag::err_no_member) 2768 << MemberName << DC 2769 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2770 return ExprError(); 2771 } 2772 2773 // Diagnose lookups that find only declarations from a non-base 2774 // type. This is possible for either qualified lookups (which may 2775 // have been qualified with an unrelated type) or implicit member 2776 // expressions (which were found with unqualified lookup and thus 2777 // may have come from an enclosing scope). Note that it's okay for 2778 // lookup to find declarations from a non-base type as long as those 2779 // aren't the ones picked by overload resolution. 2780 if ((SS.isSet() || !BaseExpr || 2781 (isa<CXXThisExpr>(BaseExpr) && 2782 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2783 !SuppressQualifierCheck && 2784 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2785 return ExprError(); 2786 2787 // Construct an unresolved result if we in fact got an unresolved 2788 // result. 2789 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2790 bool Dependent = 2791 BaseExprType->isDependentType() || 2792 R.isUnresolvableResult() || 2793 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2794 2795 // Suppress any lookup-related diagnostics; we'll do these when we 2796 // pick a member. 2797 R.suppressDiagnostics(); 2798 2799 UnresolvedMemberExpr *MemExpr 2800 = UnresolvedMemberExpr::Create(Context, Dependent, 2801 R.isUnresolvableResult(), 2802 BaseExpr, BaseExprType, 2803 IsArrow, OpLoc, 2804 Qualifier, SS.getRange(), 2805 MemberName, MemberLoc, 2806 TemplateArgs, R.begin(), R.end()); 2807 2808 return Owned(MemExpr); 2809 } 2810 2811 assert(R.isSingleResult()); 2812 DeclAccessPair FoundDecl = R.begin().getPair(); 2813 NamedDecl *MemberDecl = R.getFoundDecl(); 2814 2815 // FIXME: diagnose the presence of template arguments now. 2816 2817 // If the decl being referenced had an error, return an error for this 2818 // sub-expr without emitting another error, in order to avoid cascading 2819 // error cases. 2820 if (MemberDecl->isInvalidDecl()) 2821 return ExprError(); 2822 2823 // Handle the implicit-member-access case. 2824 if (!BaseExpr) { 2825 // If this is not an instance member, convert to a non-member access. 2826 if (!MemberDecl->isCXXInstanceMember()) 2827 return BuildDeclarationNameExpr(SS, R.getNameLoc(), MemberDecl); 2828 2829 SourceLocation Loc = R.getNameLoc(); 2830 if (SS.getRange().isValid()) 2831 Loc = SS.getRange().getBegin(); 2832 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2833 } 2834 2835 bool ShouldCheckUse = true; 2836 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2837 // Don't diagnose the use of a virtual member function unless it's 2838 // explicitly qualified. 2839 if (MD->isVirtual() && !SS.isSet()) 2840 ShouldCheckUse = false; 2841 } 2842 2843 // Check the use of this member. 2844 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2845 Owned(BaseExpr); 2846 return ExprError(); 2847 } 2848 2849 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2850 // We may have found a field within an anonymous union or struct 2851 // (C++ [class.union]). 2852 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2853 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2854 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2855 BaseExpr, OpLoc); 2856 2857 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2858 QualType MemberType = FD->getType(); 2859 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2860 MemberType = Ref->getPointeeType(); 2861 else { 2862 Qualifiers BaseQuals = BaseType.getQualifiers(); 2863 BaseQuals.removeObjCGCAttr(); 2864 if (FD->isMutable()) BaseQuals.removeConst(); 2865 2866 Qualifiers MemberQuals 2867 = Context.getCanonicalType(MemberType).getQualifiers(); 2868 2869 Qualifiers Combined = BaseQuals + MemberQuals; 2870 if (Combined != MemberQuals) 2871 MemberType = Context.getQualifiedType(MemberType, Combined); 2872 } 2873 2874 MarkDeclarationReferenced(MemberLoc, FD); 2875 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2876 return ExprError(); 2877 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2878 FD, FoundDecl, MemberLoc, MemberType)); 2879 } 2880 2881 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2882 MarkDeclarationReferenced(MemberLoc, Var); 2883 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2884 Var, FoundDecl, MemberLoc, 2885 Var->getType().getNonReferenceType())); 2886 } 2887 2888 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2889 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2890 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2891 MemberFn, FoundDecl, MemberLoc, 2892 MemberFn->getType())); 2893 } 2894 2895 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2896 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2897 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2898 Enum, FoundDecl, MemberLoc, Enum->getType())); 2899 } 2900 2901 Owned(BaseExpr); 2902 2903 // We found something that we didn't expect. Complain. 2904 if (isa<TypeDecl>(MemberDecl)) 2905 Diag(MemberLoc,diag::err_typecheck_member_reference_type) 2906 << MemberName << BaseType << int(IsArrow); 2907 else 2908 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 2909 << MemberName << BaseType << int(IsArrow); 2910 2911 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 2912 << MemberName; 2913 R.suppressDiagnostics(); 2914 return ExprError(); 2915} 2916 2917/// Look up the given member of the given non-type-dependent 2918/// expression. This can return in one of two ways: 2919/// * If it returns a sentinel null-but-valid result, the caller will 2920/// assume that lookup was performed and the results written into 2921/// the provided structure. It will take over from there. 2922/// * Otherwise, the returned expression will be produced in place of 2923/// an ordinary member expression. 2924/// 2925/// The ObjCImpDecl bit is a gross hack that will need to be properly 2926/// fixed for ObjC++. 2927Sema::OwningExprResult 2928Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2929 bool &IsArrow, SourceLocation OpLoc, 2930 CXXScopeSpec &SS, 2931 DeclPtrTy ObjCImpDecl, bool HasTemplateArgs) { 2932 assert(BaseExpr && "no base expression"); 2933 2934 // Perform default conversions. 2935 DefaultFunctionArrayConversion(BaseExpr); 2936 2937 QualType BaseType = BaseExpr->getType(); 2938 assert(!BaseType->isDependentType()); 2939 2940 DeclarationName MemberName = R.getLookupName(); 2941 SourceLocation MemberLoc = R.getNameLoc(); 2942 2943 // If the user is trying to apply -> or . to a function pointer 2944 // type, it's probably because they forgot parentheses to call that 2945 // function. Suggest the addition of those parentheses, build the 2946 // call, and continue on. 2947 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 2948 if (const FunctionProtoType *Fun 2949 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 2950 QualType ResultTy = Fun->getResultType(); 2951 if (Fun->getNumArgs() == 0 && 2952 ((!IsArrow && ResultTy->isRecordType()) || 2953 (IsArrow && ResultTy->isPointerType() && 2954 ResultTy->getAs<PointerType>()->getPointeeType() 2955 ->isRecordType()))) { 2956 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 2957 Diag(Loc, diag::err_member_reference_needs_call) 2958 << QualType(Fun, 0) 2959 << FixItHint::CreateInsertion(Loc, "()"); 2960 2961 OwningExprResult NewBase 2962 = ActOnCallExpr(0, ExprArg(*this, BaseExpr), Loc, 2963 MultiExprArg(*this, 0, 0), 0, Loc); 2964 BaseExpr = 0; 2965 if (NewBase.isInvalid()) 2966 return ExprError(); 2967 2968 BaseExpr = NewBase.takeAs<Expr>(); 2969 DefaultFunctionArrayConversion(BaseExpr); 2970 BaseType = BaseExpr->getType(); 2971 } 2972 } 2973 } 2974 2975 // If this is an Objective-C pseudo-builtin and a definition is provided then 2976 // use that. 2977 if (BaseType->isObjCIdType()) { 2978 if (IsArrow) { 2979 // Handle the following exceptional case PObj->isa. 2980 if (const ObjCObjectPointerType *OPT = 2981 BaseType->getAs<ObjCObjectPointerType>()) { 2982 if (OPT->getObjectType()->isObjCId() && 2983 MemberName.getAsIdentifierInfo()->isStr("isa")) 2984 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 2985 Context.getObjCClassType())); 2986 } 2987 } 2988 // We have an 'id' type. Rather than fall through, we check if this 2989 // is a reference to 'isa'. 2990 if (BaseType != Context.ObjCIdRedefinitionType) { 2991 BaseType = Context.ObjCIdRedefinitionType; 2992 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 2993 } 2994 } 2995 2996 // If this is an Objective-C pseudo-builtin and a definition is provided then 2997 // use that. 2998 if (Context.isObjCSelType(BaseType)) { 2999 // We have an 'SEL' type. Rather than fall through, we check if this 3000 // is a reference to 'sel_id'. 3001 if (BaseType != Context.ObjCSelRedefinitionType) { 3002 BaseType = Context.ObjCSelRedefinitionType; 3003 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3004 } 3005 } 3006 3007 assert(!BaseType.isNull() && "no type for member expression"); 3008 3009 // Handle properties on ObjC 'Class' types. 3010 if (!IsArrow && BaseType->isObjCClassType()) { 3011 // Also must look for a getter name which uses property syntax. 3012 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3013 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3014 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 3015 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3016 ObjCMethodDecl *Getter; 3017 // FIXME: need to also look locally in the implementation. 3018 if ((Getter = IFace->lookupClassMethod(Sel))) { 3019 // Check the use of this method. 3020 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3021 return ExprError(); 3022 } 3023 // If we found a getter then this may be a valid dot-reference, we 3024 // will look for the matching setter, in case it is needed. 3025 Selector SetterSel = 3026 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3027 PP.getSelectorTable(), Member); 3028 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3029 if (!Setter) { 3030 // If this reference is in an @implementation, also check for 'private' 3031 // methods. 3032 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3033 } 3034 // Look through local category implementations associated with the class. 3035 if (!Setter) 3036 Setter = IFace->getCategoryClassMethod(SetterSel); 3037 3038 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3039 return ExprError(); 3040 3041 if (Getter || Setter) { 3042 QualType PType; 3043 3044 if (Getter) 3045 PType = Getter->getSendResultType(); 3046 else 3047 // Get the expression type from Setter's incoming parameter. 3048 PType = (*(Setter->param_end() -1))->getType(); 3049 // FIXME: we must check that the setter has property type. 3050 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 3051 PType, 3052 Setter, MemberLoc, BaseExpr)); 3053 } 3054 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3055 << MemberName << BaseType); 3056 } 3057 } 3058 3059 if (BaseType->isObjCClassType() && 3060 BaseType != Context.ObjCClassRedefinitionType) { 3061 BaseType = Context.ObjCClassRedefinitionType; 3062 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3063 } 3064 3065 if (IsArrow) { 3066 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3067 BaseType = PT->getPointeeType(); 3068 else if (BaseType->isObjCObjectPointerType()) 3069 ; 3070 else if (BaseType->isRecordType()) { 3071 // Recover from arrow accesses to records, e.g.: 3072 // struct MyRecord foo; 3073 // foo->bar 3074 // This is actually well-formed in C++ if MyRecord has an 3075 // overloaded operator->, but that should have been dealt with 3076 // by now. 3077 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3078 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3079 << FixItHint::CreateReplacement(OpLoc, "."); 3080 IsArrow = false; 3081 } else { 3082 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3083 << BaseType << BaseExpr->getSourceRange(); 3084 return ExprError(); 3085 } 3086 } else { 3087 // Recover from dot accesses to pointers, e.g.: 3088 // type *foo; 3089 // foo.bar 3090 // This is actually well-formed in two cases: 3091 // - 'type' is an Objective C type 3092 // - 'bar' is a pseudo-destructor name which happens to refer to 3093 // the appropriate pointer type 3094 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3095 const PointerType *PT = BaseType->getAs<PointerType>(); 3096 if (PT && PT->getPointeeType()->isRecordType()) { 3097 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3098 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3099 << FixItHint::CreateReplacement(OpLoc, "->"); 3100 BaseType = PT->getPointeeType(); 3101 IsArrow = true; 3102 } 3103 } 3104 } 3105 3106 // Handle field access to simple records. 3107 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3108 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3109 RTy, OpLoc, SS, HasTemplateArgs)) 3110 return ExprError(); 3111 return Owned((Expr*) 0); 3112 } 3113 3114 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3115 // (*Obj).ivar. 3116 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3117 (!IsArrow && BaseType->isObjCObjectType())) { 3118 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3119 ObjCInterfaceDecl *IDecl = 3120 OPT ? OPT->getInterfaceDecl() 3121 : BaseType->getAs<ObjCObjectType>()->getInterface(); 3122 if (IDecl) { 3123 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3124 3125 ObjCInterfaceDecl *ClassDeclared; 3126 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3127 3128 if (!IV) { 3129 // Attempt to correct for typos in ivar names. 3130 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3131 LookupMemberName); 3132 if (CorrectTypo(Res, 0, 0, IDecl, false, CTC_MemberLookup) && 3133 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3134 Diag(R.getNameLoc(), 3135 diag::err_typecheck_member_reference_ivar_suggest) 3136 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3137 << FixItHint::CreateReplacement(R.getNameLoc(), 3138 IV->getNameAsString()); 3139 Diag(IV->getLocation(), diag::note_previous_decl) 3140 << IV->getDeclName(); 3141 } else { 3142 Res.clear(); 3143 Res.setLookupName(Member); 3144 } 3145 } 3146 3147 if (IV) { 3148 // If the decl being referenced had an error, return an error for this 3149 // sub-expr without emitting another error, in order to avoid cascading 3150 // error cases. 3151 if (IV->isInvalidDecl()) 3152 return ExprError(); 3153 3154 // Check whether we can reference this field. 3155 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3156 return ExprError(); 3157 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3158 IV->getAccessControl() != ObjCIvarDecl::Package) { 3159 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3160 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3161 ClassOfMethodDecl = MD->getClassInterface(); 3162 else if (ObjCImpDecl && getCurFunctionDecl()) { 3163 // Case of a c-function declared inside an objc implementation. 3164 // FIXME: For a c-style function nested inside an objc implementation 3165 // class, there is no implementation context available, so we pass 3166 // down the context as argument to this routine. Ideally, this context 3167 // need be passed down in the AST node and somehow calculated from the 3168 // AST for a function decl. 3169 Decl *ImplDecl = ObjCImpDecl.getAs<Decl>(); 3170 if (ObjCImplementationDecl *IMPD = 3171 dyn_cast<ObjCImplementationDecl>(ImplDecl)) 3172 ClassOfMethodDecl = IMPD->getClassInterface(); 3173 else if (ObjCCategoryImplDecl* CatImplClass = 3174 dyn_cast<ObjCCategoryImplDecl>(ImplDecl)) 3175 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3176 } 3177 3178 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3179 if (ClassDeclared != IDecl || 3180 ClassOfMethodDecl != ClassDeclared) 3181 Diag(MemberLoc, diag::error_private_ivar_access) 3182 << IV->getDeclName(); 3183 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3184 // @protected 3185 Diag(MemberLoc, diag::error_protected_ivar_access) 3186 << IV->getDeclName(); 3187 } 3188 3189 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3190 MemberLoc, BaseExpr, 3191 IsArrow)); 3192 } 3193 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3194 << IDecl->getDeclName() << MemberName 3195 << BaseExpr->getSourceRange()); 3196 } 3197 } 3198 // Handle properties on 'id' and qualified "id". 3199 if (!IsArrow && (BaseType->isObjCIdType() || 3200 BaseType->isObjCQualifiedIdType())) { 3201 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3202 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3203 3204 // Check protocols on qualified interfaces. 3205 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3206 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3207 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3208 // Check the use of this declaration 3209 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3210 return ExprError(); 3211 3212 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3213 MemberLoc, BaseExpr)); 3214 } 3215 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3216 // Check the use of this method. 3217 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3218 return ExprError(); 3219 3220 return Owned(ObjCMessageExpr::Create(Context, 3221 OMD->getSendResultType(), 3222 OpLoc, BaseExpr, Sel, 3223 OMD, NULL, 0, MemberLoc)); 3224 } 3225 } 3226 3227 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3228 << MemberName << BaseType); 3229 } 3230 3231 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3232 // pointer to a (potentially qualified) interface type. 3233 if (!IsArrow) 3234 if (const ObjCObjectPointerType *OPT = 3235 BaseType->getAsObjCInterfacePointerType()) 3236 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc); 3237 3238 // Handle the following exceptional case (*Obj).isa. 3239 if (!IsArrow && 3240 BaseType->isObjCObjectType() && 3241 BaseType->getAs<ObjCObjectType>()->isObjCId() && 3242 MemberName.getAsIdentifierInfo()->isStr("isa")) 3243 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3244 Context.getObjCClassType())); 3245 3246 // Handle 'field access' to vectors, such as 'V.xx'. 3247 if (BaseType->isExtVectorType()) { 3248 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3249 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3250 if (ret.isNull()) 3251 return ExprError(); 3252 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3253 MemberLoc)); 3254 } 3255 3256 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3257 << BaseType << BaseExpr->getSourceRange(); 3258 3259 return ExprError(); 3260} 3261 3262/// The main callback when the parser finds something like 3263/// expression . [nested-name-specifier] identifier 3264/// expression -> [nested-name-specifier] identifier 3265/// where 'identifier' encompasses a fairly broad spectrum of 3266/// possibilities, including destructor and operator references. 3267/// 3268/// \param OpKind either tok::arrow or tok::period 3269/// \param HasTrailingLParen whether the next token is '(', which 3270/// is used to diagnose mis-uses of special members that can 3271/// only be called 3272/// \param ObjCImpDecl the current ObjC @implementation decl; 3273/// this is an ugly hack around the fact that ObjC @implementations 3274/// aren't properly put in the context chain 3275Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, ExprArg BaseArg, 3276 SourceLocation OpLoc, 3277 tok::TokenKind OpKind, 3278 CXXScopeSpec &SS, 3279 UnqualifiedId &Id, 3280 DeclPtrTy ObjCImpDecl, 3281 bool HasTrailingLParen) { 3282 if (SS.isSet() && SS.isInvalid()) 3283 return ExprError(); 3284 3285 TemplateArgumentListInfo TemplateArgsBuffer; 3286 3287 // Decompose the name into its component parts. 3288 DeclarationName Name; 3289 SourceLocation NameLoc; 3290 const TemplateArgumentListInfo *TemplateArgs; 3291 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3292 Name, NameLoc, TemplateArgs); 3293 3294 bool IsArrow = (OpKind == tok::arrow); 3295 3296 NamedDecl *FirstQualifierInScope 3297 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3298 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3299 3300 // This is a postfix expression, so get rid of ParenListExprs. 3301 BaseArg = MaybeConvertParenListExprToParenExpr(S, move(BaseArg)); 3302 3303 Expr *Base = BaseArg.takeAs<Expr>(); 3304 OwningExprResult Result(*this); 3305 if (Base->getType()->isDependentType() || Name.isDependentName() || 3306 isDependentScopeSpecifier(SS)) { 3307 Result = ActOnDependentMemberExpr(ExprArg(*this, Base), Base->getType(), 3308 IsArrow, OpLoc, 3309 SS, FirstQualifierInScope, 3310 Name, NameLoc, 3311 TemplateArgs); 3312 } else { 3313 LookupResult R(*this, Name, NameLoc, LookupMemberName); 3314 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3315 SS, ObjCImpDecl, TemplateArgs != 0); 3316 3317 if (Result.isInvalid()) { 3318 Owned(Base); 3319 return ExprError(); 3320 } 3321 3322 if (Result.get()) { 3323 // The only way a reference to a destructor can be used is to 3324 // immediately call it, which falls into this case. If the 3325 // next token is not a '(', produce a diagnostic and build the 3326 // call now. 3327 if (!HasTrailingLParen && 3328 Id.getKind() == UnqualifiedId::IK_DestructorName) 3329 return DiagnoseDtorReference(NameLoc, move(Result)); 3330 3331 return move(Result); 3332 } 3333 3334 Result = BuildMemberReferenceExpr(ExprArg(*this, Base), Base->getType(), 3335 OpLoc, IsArrow, SS, FirstQualifierInScope, 3336 R, TemplateArgs); 3337 } 3338 3339 return move(Result); 3340} 3341 3342Sema::OwningExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3343 FunctionDecl *FD, 3344 ParmVarDecl *Param) { 3345 if (Param->hasUnparsedDefaultArg()) { 3346 Diag (CallLoc, 3347 diag::err_use_of_default_argument_to_function_declared_later) << 3348 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3349 Diag(UnparsedDefaultArgLocs[Param], 3350 diag::note_default_argument_declared_here); 3351 } else { 3352 if (Param->hasUninstantiatedDefaultArg()) { 3353 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3354 3355 // Instantiate the expression. 3356 MultiLevelTemplateArgumentList ArgList 3357 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3358 3359 std::pair<const TemplateArgument *, unsigned> Innermost 3360 = ArgList.getInnermost(); 3361 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3362 Innermost.second); 3363 3364 OwningExprResult Result = SubstExpr(UninstExpr, ArgList); 3365 if (Result.isInvalid()) 3366 return ExprError(); 3367 3368 // Check the expression as an initializer for the parameter. 3369 InitializedEntity Entity 3370 = InitializedEntity::InitializeParameter(Param); 3371 InitializationKind Kind 3372 = InitializationKind::CreateCopy(Param->getLocation(), 3373 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3374 Expr *ResultE = Result.takeAs<Expr>(); 3375 3376 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3377 Result = InitSeq.Perform(*this, Entity, Kind, 3378 MultiExprArg(*this, (void**)&ResultE, 1)); 3379 if (Result.isInvalid()) 3380 return ExprError(); 3381 3382 // Build the default argument expression. 3383 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3384 Result.takeAs<Expr>())); 3385 } 3386 3387 // If the default expression creates temporaries, we need to 3388 // push them to the current stack of expression temporaries so they'll 3389 // be properly destroyed. 3390 // FIXME: We should really be rebuilding the default argument with new 3391 // bound temporaries; see the comment in PR5810. 3392 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3393 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3394 } 3395 3396 // We already type-checked the argument, so we know it works. 3397 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3398} 3399 3400/// ConvertArgumentsForCall - Converts the arguments specified in 3401/// Args/NumArgs to the parameter types of the function FDecl with 3402/// function prototype Proto. Call is the call expression itself, and 3403/// Fn is the function expression. For a C++ member function, this 3404/// routine does not attempt to convert the object argument. Returns 3405/// true if the call is ill-formed. 3406bool 3407Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3408 FunctionDecl *FDecl, 3409 const FunctionProtoType *Proto, 3410 Expr **Args, unsigned NumArgs, 3411 SourceLocation RParenLoc) { 3412 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3413 // assignment, to the types of the corresponding parameter, ... 3414 unsigned NumArgsInProto = Proto->getNumArgs(); 3415 bool Invalid = false; 3416 3417 // If too few arguments are available (and we don't have default 3418 // arguments for the remaining parameters), don't make the call. 3419 if (NumArgs < NumArgsInProto) { 3420 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3421 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3422 << Fn->getType()->isBlockPointerType() 3423 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 3424 Call->setNumArgs(Context, NumArgsInProto); 3425 } 3426 3427 // If too many are passed and not variadic, error on the extras and drop 3428 // them. 3429 if (NumArgs > NumArgsInProto) { 3430 if (!Proto->isVariadic()) { 3431 Diag(Args[NumArgsInProto]->getLocStart(), 3432 diag::err_typecheck_call_too_many_args) 3433 << Fn->getType()->isBlockPointerType() 3434 << NumArgsInProto << NumArgs << Fn->getSourceRange() 3435 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3436 Args[NumArgs-1]->getLocEnd()); 3437 // This deletes the extra arguments. 3438 Call->setNumArgs(Context, NumArgsInProto); 3439 return true; 3440 } 3441 } 3442 llvm::SmallVector<Expr *, 8> AllArgs; 3443 VariadicCallType CallType = 3444 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3445 if (Fn->getType()->isBlockPointerType()) 3446 CallType = VariadicBlock; // Block 3447 else if (isa<MemberExpr>(Fn)) 3448 CallType = VariadicMethod; 3449 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3450 Proto, 0, Args, NumArgs, AllArgs, CallType); 3451 if (Invalid) 3452 return true; 3453 unsigned TotalNumArgs = AllArgs.size(); 3454 for (unsigned i = 0; i < TotalNumArgs; ++i) 3455 Call->setArg(i, AllArgs[i]); 3456 3457 return false; 3458} 3459 3460bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3461 FunctionDecl *FDecl, 3462 const FunctionProtoType *Proto, 3463 unsigned FirstProtoArg, 3464 Expr **Args, unsigned NumArgs, 3465 llvm::SmallVector<Expr *, 8> &AllArgs, 3466 VariadicCallType CallType) { 3467 unsigned NumArgsInProto = Proto->getNumArgs(); 3468 unsigned NumArgsToCheck = NumArgs; 3469 bool Invalid = false; 3470 if (NumArgs != NumArgsInProto) 3471 // Use default arguments for missing arguments 3472 NumArgsToCheck = NumArgsInProto; 3473 unsigned ArgIx = 0; 3474 // Continue to check argument types (even if we have too few/many args). 3475 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3476 QualType ProtoArgType = Proto->getArgType(i); 3477 3478 Expr *Arg; 3479 if (ArgIx < NumArgs) { 3480 Arg = Args[ArgIx++]; 3481 3482 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3483 ProtoArgType, 3484 PDiag(diag::err_call_incomplete_argument) 3485 << Arg->getSourceRange())) 3486 return true; 3487 3488 // Pass the argument 3489 ParmVarDecl *Param = 0; 3490 if (FDecl && i < FDecl->getNumParams()) 3491 Param = FDecl->getParamDecl(i); 3492 3493 3494 InitializedEntity Entity = 3495 Param? InitializedEntity::InitializeParameter(Param) 3496 : InitializedEntity::InitializeParameter(ProtoArgType); 3497 OwningExprResult ArgE = PerformCopyInitialization(Entity, 3498 SourceLocation(), 3499 Owned(Arg)); 3500 if (ArgE.isInvalid()) 3501 return true; 3502 3503 Arg = ArgE.takeAs<Expr>(); 3504 } else { 3505 ParmVarDecl *Param = FDecl->getParamDecl(i); 3506 3507 OwningExprResult ArgExpr = 3508 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3509 if (ArgExpr.isInvalid()) 3510 return true; 3511 3512 Arg = ArgExpr.takeAs<Expr>(); 3513 } 3514 AllArgs.push_back(Arg); 3515 } 3516 3517 // If this is a variadic call, handle args passed through "...". 3518 if (CallType != VariadicDoesNotApply) { 3519 // Promote the arguments (C99 6.5.2.2p7). 3520 for (unsigned i = ArgIx; i != NumArgs; ++i) { 3521 Expr *Arg = Args[i]; 3522 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 3523 AllArgs.push_back(Arg); 3524 } 3525 } 3526 return Invalid; 3527} 3528 3529/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3530/// This provides the location of the left/right parens and a list of comma 3531/// locations. 3532Action::OwningExprResult 3533Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc, 3534 MultiExprArg args, 3535 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3536 unsigned NumArgs = args.size(); 3537 3538 // Since this might be a postfix expression, get rid of ParenListExprs. 3539 fn = MaybeConvertParenListExprToParenExpr(S, move(fn)); 3540 3541 Expr *Fn = fn.takeAs<Expr>(); 3542 Expr **Args = reinterpret_cast<Expr**>(args.release()); 3543 assert(Fn && "no function call expression"); 3544 3545 if (getLangOptions().CPlusPlus) { 3546 // If this is a pseudo-destructor expression, build the call immediately. 3547 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3548 if (NumArgs > 0) { 3549 // Pseudo-destructor calls should not have any arguments. 3550 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3551 << FixItHint::CreateRemoval( 3552 SourceRange(Args[0]->getLocStart(), 3553 Args[NumArgs-1]->getLocEnd())); 3554 3555 for (unsigned I = 0; I != NumArgs; ++I) 3556 Args[I]->Destroy(Context); 3557 3558 NumArgs = 0; 3559 } 3560 3561 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3562 RParenLoc)); 3563 } 3564 3565 // Determine whether this is a dependent call inside a C++ template, 3566 // in which case we won't do any semantic analysis now. 3567 // FIXME: Will need to cache the results of name lookup (including ADL) in 3568 // Fn. 3569 bool Dependent = false; 3570 if (Fn->isTypeDependent()) 3571 Dependent = true; 3572 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3573 Dependent = true; 3574 3575 if (Dependent) 3576 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3577 Context.DependentTy, RParenLoc)); 3578 3579 // Determine whether this is a call to an object (C++ [over.call.object]). 3580 if (Fn->getType()->isRecordType()) 3581 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3582 CommaLocs, RParenLoc)); 3583 3584 Expr *NakedFn = Fn->IgnoreParens(); 3585 3586 // Determine whether this is a call to an unresolved member function. 3587 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3588 // If lookup was unresolved but not dependent (i.e. didn't find 3589 // an unresolved using declaration), it has to be an overloaded 3590 // function set, which means it must contain either multiple 3591 // declarations (all methods or method templates) or a single 3592 // method template. 3593 assert((MemE->getNumDecls() > 1) || 3594 isa<FunctionTemplateDecl>( 3595 (*MemE->decls_begin())->getUnderlyingDecl())); 3596 (void)MemE; 3597 3598 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3599 CommaLocs, RParenLoc); 3600 } 3601 3602 // Determine whether this is a call to a member function. 3603 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3604 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3605 if (isa<CXXMethodDecl>(MemDecl)) 3606 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3607 CommaLocs, RParenLoc); 3608 } 3609 3610 // Determine whether this is a call to a pointer-to-member function. 3611 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3612 if (BO->getOpcode() == BinaryOperator::PtrMemD || 3613 BO->getOpcode() == BinaryOperator::PtrMemI) { 3614 if (const FunctionProtoType *FPT 3615 = BO->getType()->getAs<FunctionProtoType>()) { 3616 QualType ResultTy = FPT->getCallResultType(Context); 3617 3618 ExprOwningPtr<CXXMemberCallExpr> 3619 TheCall(this, new (Context) CXXMemberCallExpr(Context, BO, Args, 3620 NumArgs, ResultTy, 3621 RParenLoc)); 3622 3623 if (CheckCallReturnType(FPT->getResultType(), 3624 BO->getRHS()->getSourceRange().getBegin(), 3625 TheCall.get(), 0)) 3626 return ExprError(); 3627 3628 if (ConvertArgumentsForCall(&*TheCall, BO, 0, FPT, Args, NumArgs, 3629 RParenLoc)) 3630 return ExprError(); 3631 3632 return Owned(MaybeBindToTemporary(TheCall.release()).release()); 3633 } 3634 return ExprError(Diag(Fn->getLocStart(), 3635 diag::err_typecheck_call_not_function) 3636 << Fn->getType() << Fn->getSourceRange()); 3637 } 3638 } 3639 } 3640 3641 // If we're directly calling a function, get the appropriate declaration. 3642 // Also, in C++, keep track of whether we should perform argument-dependent 3643 // lookup and whether there were any explicitly-specified template arguments. 3644 3645 Expr *NakedFn = Fn->IgnoreParens(); 3646 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3647 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3648 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 3649 CommaLocs, RParenLoc); 3650 } 3651 3652 NamedDecl *NDecl = 0; 3653 if (isa<DeclRefExpr>(NakedFn)) 3654 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3655 3656 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3657} 3658 3659/// BuildResolvedCallExpr - Build a call to a resolved expression, 3660/// i.e. an expression not of \p OverloadTy. The expression should 3661/// unary-convert to an expression of function-pointer or 3662/// block-pointer type. 3663/// 3664/// \param NDecl the declaration being called, if available 3665Sema::OwningExprResult 3666Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3667 SourceLocation LParenLoc, 3668 Expr **Args, unsigned NumArgs, 3669 SourceLocation RParenLoc) { 3670 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3671 3672 // Promote the function operand. 3673 UsualUnaryConversions(Fn); 3674 3675 // Make the call expr early, before semantic checks. This guarantees cleanup 3676 // of arguments and function on error. 3677 ExprOwningPtr<CallExpr> TheCall(this, new (Context) CallExpr(Context, Fn, 3678 Args, NumArgs, 3679 Context.BoolTy, 3680 RParenLoc)); 3681 3682 const FunctionType *FuncT; 3683 if (!Fn->getType()->isBlockPointerType()) { 3684 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3685 // have type pointer to function". 3686 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3687 if (PT == 0) 3688 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3689 << Fn->getType() << Fn->getSourceRange()); 3690 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3691 } else { // This is a block call. 3692 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3693 getAs<FunctionType>(); 3694 } 3695 if (FuncT == 0) 3696 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3697 << Fn->getType() << Fn->getSourceRange()); 3698 3699 // Check for a valid return type 3700 if (CheckCallReturnType(FuncT->getResultType(), 3701 Fn->getSourceRange().getBegin(), TheCall.get(), 3702 FDecl)) 3703 return ExprError(); 3704 3705 // We know the result type of the call, set it. 3706 TheCall->setType(FuncT->getCallResultType(Context)); 3707 3708 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3709 if (ConvertArgumentsForCall(&*TheCall, Fn, FDecl, Proto, Args, NumArgs, 3710 RParenLoc)) 3711 return ExprError(); 3712 } else { 3713 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3714 3715 if (FDecl) { 3716 // Check if we have too few/too many template arguments, based 3717 // on our knowledge of the function definition. 3718 const FunctionDecl *Def = 0; 3719 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 3720 const FunctionProtoType *Proto = 3721 Def->getType()->getAs<FunctionProtoType>(); 3722 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3723 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3724 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3725 } 3726 } 3727 } 3728 3729 // Promote the arguments (C99 6.5.2.2p6). 3730 for (unsigned i = 0; i != NumArgs; i++) { 3731 Expr *Arg = Args[i]; 3732 DefaultArgumentPromotion(Arg); 3733 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3734 Arg->getType(), 3735 PDiag(diag::err_call_incomplete_argument) 3736 << Arg->getSourceRange())) 3737 return ExprError(); 3738 TheCall->setArg(i, Arg); 3739 } 3740 } 3741 3742 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3743 if (!Method->isStatic()) 3744 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3745 << Fn->getSourceRange()); 3746 3747 // Check for sentinels 3748 if (NDecl) 3749 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3750 3751 // Do special checking on direct calls to functions. 3752 if (FDecl) { 3753 if (CheckFunctionCall(FDecl, TheCall.get())) 3754 return ExprError(); 3755 3756 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3757 return CheckBuiltinFunctionCall(BuiltinID, TheCall.take()); 3758 } else if (NDecl) { 3759 if (CheckBlockCall(NDecl, TheCall.get())) 3760 return ExprError(); 3761 } 3762 3763 return MaybeBindToTemporary(TheCall.take()); 3764} 3765 3766Action::OwningExprResult 3767Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, TypeTy *Ty, 3768 SourceLocation RParenLoc, ExprArg InitExpr) { 3769 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3770 // FIXME: put back this assert when initializers are worked out. 3771 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3772 3773 TypeSourceInfo *TInfo; 3774 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3775 if (!TInfo) 3776 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3777 3778 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, move(InitExpr)); 3779} 3780 3781Action::OwningExprResult 3782Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3783 SourceLocation RParenLoc, ExprArg InitExpr) { 3784 QualType literalType = TInfo->getType(); 3785 Expr *literalExpr = static_cast<Expr*>(InitExpr.get()); 3786 3787 if (literalType->isArrayType()) { 3788 if (literalType->isVariableArrayType()) 3789 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3790 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3791 } else if (!literalType->isDependentType() && 3792 RequireCompleteType(LParenLoc, literalType, 3793 PDiag(diag::err_typecheck_decl_incomplete_type) 3794 << SourceRange(LParenLoc, 3795 literalExpr->getSourceRange().getEnd()))) 3796 return ExprError(); 3797 3798 InitializedEntity Entity 3799 = InitializedEntity::InitializeTemporary(literalType); 3800 InitializationKind Kind 3801 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3802 /*IsCStyleCast=*/true); 3803 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3804 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3805 MultiExprArg(*this, (void**)&literalExpr, 1), 3806 &literalType); 3807 if (Result.isInvalid()) 3808 return ExprError(); 3809 InitExpr.release(); 3810 literalExpr = static_cast<Expr*>(Result.get()); 3811 3812 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3813 if (isFileScope) { // 6.5.2.5p3 3814 if (CheckForConstantInitializer(literalExpr, literalType)) 3815 return ExprError(); 3816 } 3817 3818 Result.release(); 3819 3820 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3821 literalExpr, isFileScope)); 3822} 3823 3824Action::OwningExprResult 3825Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3826 SourceLocation RBraceLoc) { 3827 unsigned NumInit = initlist.size(); 3828 Expr **InitList = reinterpret_cast<Expr**>(initlist.release()); 3829 3830 // Semantic analysis for initializers is done by ActOnDeclarator() and 3831 // CheckInitializer() - it requires knowledge of the object being intialized. 3832 3833 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 3834 NumInit, RBraceLoc); 3835 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3836 return Owned(E); 3837} 3838 3839static CastExpr::CastKind getScalarCastKind(ASTContext &Context, 3840 QualType SrcTy, QualType DestTy) { 3841 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3842 return CastExpr::CK_NoOp; 3843 3844 if (SrcTy->hasPointerRepresentation()) { 3845 if (DestTy->hasPointerRepresentation()) 3846 return DestTy->isObjCObjectPointerType() ? 3847 CastExpr::CK_AnyPointerToObjCPointerCast : 3848 CastExpr::CK_BitCast; 3849 if (DestTy->isIntegerType()) 3850 return CastExpr::CK_PointerToIntegral; 3851 } 3852 3853 if (SrcTy->isIntegerType()) { 3854 if (DestTy->isIntegerType()) 3855 return CastExpr::CK_IntegralCast; 3856 if (DestTy->hasPointerRepresentation()) 3857 return CastExpr::CK_IntegralToPointer; 3858 if (DestTy->isRealFloatingType()) 3859 return CastExpr::CK_IntegralToFloating; 3860 } 3861 3862 if (SrcTy->isRealFloatingType()) { 3863 if (DestTy->isRealFloatingType()) 3864 return CastExpr::CK_FloatingCast; 3865 if (DestTy->isIntegerType()) 3866 return CastExpr::CK_FloatingToIntegral; 3867 } 3868 3869 // FIXME: Assert here. 3870 // assert(false && "Unhandled cast combination!"); 3871 return CastExpr::CK_Unknown; 3872} 3873 3874/// CheckCastTypes - Check type constraints for casting between types. 3875bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3876 CastExpr::CastKind& Kind, 3877 CXXBaseSpecifierArray &BasePath, 3878 bool FunctionalStyle) { 3879 if (getLangOptions().CPlusPlus) 3880 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, BasePath, 3881 FunctionalStyle); 3882 3883 DefaultFunctionArrayLvalueConversion(castExpr); 3884 3885 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3886 // type needs to be scalar. 3887 if (castType->isVoidType()) { 3888 // Cast to void allows any expr type. 3889 Kind = CastExpr::CK_ToVoid; 3890 return false; 3891 } 3892 3893 if (RequireCompleteType(TyR.getBegin(), castType, 3894 diag::err_typecheck_cast_to_incomplete)) 3895 return true; 3896 3897 if (!castType->isScalarType() && !castType->isVectorType()) { 3898 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3899 (castType->isStructureType() || castType->isUnionType())) { 3900 // GCC struct/union extension: allow cast to self. 3901 // FIXME: Check that the cast destination type is complete. 3902 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3903 << castType << castExpr->getSourceRange(); 3904 Kind = CastExpr::CK_NoOp; 3905 return false; 3906 } 3907 3908 if (castType->isUnionType()) { 3909 // GCC cast to union extension 3910 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3911 RecordDecl::field_iterator Field, FieldEnd; 3912 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3913 Field != FieldEnd; ++Field) { 3914 if (Context.hasSameUnqualifiedType(Field->getType(), 3915 castExpr->getType())) { 3916 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3917 << castExpr->getSourceRange(); 3918 break; 3919 } 3920 } 3921 if (Field == FieldEnd) 3922 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3923 << castExpr->getType() << castExpr->getSourceRange(); 3924 Kind = CastExpr::CK_ToUnion; 3925 return false; 3926 } 3927 3928 // Reject any other conversions to non-scalar types. 3929 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3930 << castType << castExpr->getSourceRange(); 3931 } 3932 3933 if (!castExpr->getType()->isScalarType() && 3934 !castExpr->getType()->isVectorType()) { 3935 return Diag(castExpr->getLocStart(), 3936 diag::err_typecheck_expect_scalar_operand) 3937 << castExpr->getType() << castExpr->getSourceRange(); 3938 } 3939 3940 if (castType->isExtVectorType()) 3941 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3942 3943 if (castType->isVectorType()) 3944 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 3945 if (castExpr->getType()->isVectorType()) 3946 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 3947 3948 if (isa<ObjCSelectorExpr>(castExpr)) 3949 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 3950 3951 if (!castType->isArithmeticType()) { 3952 QualType castExprType = castExpr->getType(); 3953 if (!castExprType->isIntegralType(Context) && 3954 castExprType->isArithmeticType()) 3955 return Diag(castExpr->getLocStart(), 3956 diag::err_cast_pointer_from_non_pointer_int) 3957 << castExprType << castExpr->getSourceRange(); 3958 } else if (!castExpr->getType()->isArithmeticType()) { 3959 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 3960 return Diag(castExpr->getLocStart(), 3961 diag::err_cast_pointer_to_non_pointer_int) 3962 << castType << castExpr->getSourceRange(); 3963 } 3964 3965 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 3966 return false; 3967} 3968 3969bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 3970 CastExpr::CastKind &Kind) { 3971 assert(VectorTy->isVectorType() && "Not a vector type!"); 3972 3973 if (Ty->isVectorType() || Ty->isIntegerType()) { 3974 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 3975 return Diag(R.getBegin(), 3976 Ty->isVectorType() ? 3977 diag::err_invalid_conversion_between_vectors : 3978 diag::err_invalid_conversion_between_vector_and_integer) 3979 << VectorTy << Ty << R; 3980 } else 3981 return Diag(R.getBegin(), 3982 diag::err_invalid_conversion_between_vector_and_scalar) 3983 << VectorTy << Ty << R; 3984 3985 Kind = CastExpr::CK_BitCast; 3986 return false; 3987} 3988 3989bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 3990 CastExpr::CastKind &Kind) { 3991 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 3992 3993 QualType SrcTy = CastExpr->getType(); 3994 3995 // If SrcTy is a VectorType, the total size must match to explicitly cast to 3996 // an ExtVectorType. 3997 if (SrcTy->isVectorType()) { 3998 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 3999 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4000 << DestTy << SrcTy << R; 4001 Kind = CastExpr::CK_BitCast; 4002 return false; 4003 } 4004 4005 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4006 // conversion will take place first from scalar to elt type, and then 4007 // splat from elt type to vector. 4008 if (SrcTy->isPointerType()) 4009 return Diag(R.getBegin(), 4010 diag::err_invalid_conversion_between_vector_and_scalar) 4011 << DestTy << SrcTy << R; 4012 4013 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4014 ImpCastExprToType(CastExpr, DestElemTy, 4015 getScalarCastKind(Context, SrcTy, DestElemTy)); 4016 4017 Kind = CastExpr::CK_VectorSplat; 4018 return false; 4019} 4020 4021Action::OwningExprResult 4022Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, TypeTy *Ty, 4023 SourceLocation RParenLoc, ExprArg Op) { 4024 assert((Ty != 0) && (Op.get() != 0) && 4025 "ActOnCastExpr(): missing type or expr"); 4026 4027 TypeSourceInfo *castTInfo; 4028 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4029 if (!castTInfo) 4030 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4031 4032 // If the Expr being casted is a ParenListExpr, handle it specially. 4033 Expr *castExpr = (Expr *)Op.get(); 4034 if (isa<ParenListExpr>(castExpr)) 4035 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, move(Op), 4036 castTInfo); 4037 4038 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, move(Op)); 4039} 4040 4041Action::OwningExprResult 4042Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4043 SourceLocation RParenLoc, ExprArg Op) { 4044 Expr *castExpr = static_cast<Expr*>(Op.get()); 4045 4046 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 4047 CXXBaseSpecifierArray BasePath; 4048 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4049 Kind, BasePath)) 4050 return ExprError(); 4051 4052 Op.release(); 4053 return Owned(new (Context) CStyleCastExpr( 4054 Ty->getType().getNonLValueExprType(Context), 4055 Kind, castExpr, BasePath, Ty, 4056 LParenLoc, RParenLoc)); 4057} 4058 4059/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4060/// of comma binary operators. 4061Action::OwningExprResult 4062Sema::MaybeConvertParenListExprToParenExpr(Scope *S, ExprArg EA) { 4063 Expr *expr = EA.takeAs<Expr>(); 4064 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4065 if (!E) 4066 return Owned(expr); 4067 4068 OwningExprResult Result(*this, E->getExpr(0)); 4069 4070 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4071 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, move(Result), 4072 Owned(E->getExpr(i))); 4073 4074 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), move(Result)); 4075} 4076 4077Action::OwningExprResult 4078Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4079 SourceLocation RParenLoc, ExprArg Op, 4080 TypeSourceInfo *TInfo) { 4081 ParenListExpr *PE = (ParenListExpr *)Op.get(); 4082 QualType Ty = TInfo->getType(); 4083 bool isAltiVecLiteral = false; 4084 4085 // Check for an altivec literal, 4086 // i.e. all the elements are integer constants. 4087 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4088 if (PE->getNumExprs() == 0) { 4089 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4090 return ExprError(); 4091 } 4092 if (PE->getNumExprs() == 1) { 4093 if (!PE->getExpr(0)->getType()->isVectorType()) 4094 isAltiVecLiteral = true; 4095 } 4096 else 4097 isAltiVecLiteral = true; 4098 } 4099 4100 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4101 // then handle it as such. 4102 if (isAltiVecLiteral) { 4103 llvm::SmallVector<Expr *, 8> initExprs; 4104 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4105 initExprs.push_back(PE->getExpr(i)); 4106 4107 // FIXME: This means that pretty-printing the final AST will produce curly 4108 // braces instead of the original commas. 4109 Op.release(); 4110 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4111 &initExprs[0], 4112 initExprs.size(), RParenLoc); 4113 E->setType(Ty); 4114 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, Owned(E)); 4115 } else { 4116 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4117 // sequence of BinOp comma operators. 4118 Op = MaybeConvertParenListExprToParenExpr(S, move(Op)); 4119 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, move(Op)); 4120 } 4121} 4122 4123Action::OwningExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4124 SourceLocation R, 4125 MultiExprArg Val, 4126 TypeTy *TypeOfCast) { 4127 unsigned nexprs = Val.size(); 4128 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4129 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4130 Expr *expr; 4131 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4132 expr = new (Context) ParenExpr(L, R, exprs[0]); 4133 else 4134 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4135 return Owned(expr); 4136} 4137 4138/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4139/// In that case, lhs = cond. 4140/// C99 6.5.15 4141QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4142 SourceLocation QuestionLoc) { 4143 // C++ is sufficiently different to merit its own checker. 4144 if (getLangOptions().CPlusPlus) 4145 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4146 4147 UsualUnaryConversions(Cond); 4148 UsualUnaryConversions(LHS); 4149 UsualUnaryConversions(RHS); 4150 QualType CondTy = Cond->getType(); 4151 QualType LHSTy = LHS->getType(); 4152 QualType RHSTy = RHS->getType(); 4153 4154 // first, check the condition. 4155 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4156 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4157 << CondTy; 4158 return QualType(); 4159 } 4160 4161 // Now check the two expressions. 4162 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4163 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4164 4165 // If both operands have arithmetic type, do the usual arithmetic conversions 4166 // to find a common type: C99 6.5.15p3,5. 4167 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4168 UsualArithmeticConversions(LHS, RHS); 4169 return LHS->getType(); 4170 } 4171 4172 // If both operands are the same structure or union type, the result is that 4173 // type. 4174 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4175 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4176 if (LHSRT->getDecl() == RHSRT->getDecl()) 4177 // "If both the operands have structure or union type, the result has 4178 // that type." This implies that CV qualifiers are dropped. 4179 return LHSTy.getUnqualifiedType(); 4180 // FIXME: Type of conditional expression must be complete in C mode. 4181 } 4182 4183 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4184 // The following || allows only one side to be void (a GCC-ism). 4185 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4186 if (!LHSTy->isVoidType()) 4187 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4188 << RHS->getSourceRange(); 4189 if (!RHSTy->isVoidType()) 4190 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4191 << LHS->getSourceRange(); 4192 ImpCastExprToType(LHS, Context.VoidTy, CastExpr::CK_ToVoid); 4193 ImpCastExprToType(RHS, Context.VoidTy, CastExpr::CK_ToVoid); 4194 return Context.VoidTy; 4195 } 4196 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4197 // the type of the other operand." 4198 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4199 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4200 // promote the null to a pointer. 4201 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_Unknown); 4202 return LHSTy; 4203 } 4204 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4205 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4206 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_Unknown); 4207 return RHSTy; 4208 } 4209 4210 // All objective-c pointer type analysis is done here. 4211 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4212 QuestionLoc); 4213 if (!compositeType.isNull()) 4214 return compositeType; 4215 4216 4217 // Handle block pointer types. 4218 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4219 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4220 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4221 QualType destType = Context.getPointerType(Context.VoidTy); 4222 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4223 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4224 return destType; 4225 } 4226 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4227 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4228 return QualType(); 4229 } 4230 // We have 2 block pointer types. 4231 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4232 // Two identical block pointer types are always compatible. 4233 return LHSTy; 4234 } 4235 // The block pointer types aren't identical, continue checking. 4236 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4237 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4238 4239 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4240 rhptee.getUnqualifiedType())) { 4241 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4242 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4243 // In this situation, we assume void* type. No especially good 4244 // reason, but this is what gcc does, and we do have to pick 4245 // to get a consistent AST. 4246 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4247 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4248 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4249 return incompatTy; 4250 } 4251 // The block pointer types are compatible. 4252 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4253 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4254 return LHSTy; 4255 } 4256 4257 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4258 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4259 // get the "pointed to" types 4260 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4261 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4262 4263 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4264 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4265 // Figure out necessary qualifiers (C99 6.5.15p6) 4266 QualType destPointee 4267 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4268 QualType destType = Context.getPointerType(destPointee); 4269 // Add qualifiers if necessary. 4270 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4271 // Promote to void*. 4272 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4273 return destType; 4274 } 4275 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4276 QualType destPointee 4277 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4278 QualType destType = Context.getPointerType(destPointee); 4279 // Add qualifiers if necessary. 4280 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4281 // Promote to void*. 4282 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4283 return destType; 4284 } 4285 4286 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4287 // Two identical pointer types are always compatible. 4288 return LHSTy; 4289 } 4290 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4291 rhptee.getUnqualifiedType())) { 4292 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4293 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4294 // In this situation, we assume void* type. No especially good 4295 // reason, but this is what gcc does, and we do have to pick 4296 // to get a consistent AST. 4297 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4298 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4299 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4300 return incompatTy; 4301 } 4302 // The pointer types are compatible. 4303 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4304 // differently qualified versions of compatible types, the result type is 4305 // a pointer to an appropriately qualified version of the *composite* 4306 // type. 4307 // FIXME: Need to calculate the composite type. 4308 // FIXME: Need to add qualifiers 4309 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4310 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4311 return LHSTy; 4312 } 4313 4314 // GCC compatibility: soften pointer/integer mismatch. 4315 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4316 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4317 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4318 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_IntegralToPointer); 4319 return RHSTy; 4320 } 4321 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4322 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4323 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4324 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_IntegralToPointer); 4325 return LHSTy; 4326 } 4327 4328 // Otherwise, the operands are not compatible. 4329 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4330 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4331 return QualType(); 4332} 4333 4334/// FindCompositeObjCPointerType - Helper method to find composite type of 4335/// two objective-c pointer types of the two input expressions. 4336QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4337 SourceLocation QuestionLoc) { 4338 QualType LHSTy = LHS->getType(); 4339 QualType RHSTy = RHS->getType(); 4340 4341 // Handle things like Class and struct objc_class*. Here we case the result 4342 // to the pseudo-builtin, because that will be implicitly cast back to the 4343 // redefinition type if an attempt is made to access its fields. 4344 if (LHSTy->isObjCClassType() && 4345 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4346 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4347 return LHSTy; 4348 } 4349 if (RHSTy->isObjCClassType() && 4350 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4351 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4352 return RHSTy; 4353 } 4354 // And the same for struct objc_object* / id 4355 if (LHSTy->isObjCIdType() && 4356 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4357 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4358 return LHSTy; 4359 } 4360 if (RHSTy->isObjCIdType() && 4361 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4362 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4363 return RHSTy; 4364 } 4365 // And the same for struct objc_selector* / SEL 4366 if (Context.isObjCSelType(LHSTy) && 4367 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4368 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4369 return LHSTy; 4370 } 4371 if (Context.isObjCSelType(RHSTy) && 4372 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4373 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4374 return RHSTy; 4375 } 4376 // Check constraints for Objective-C object pointers types. 4377 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4378 4379 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4380 // Two identical object pointer types are always compatible. 4381 return LHSTy; 4382 } 4383 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4384 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4385 QualType compositeType = LHSTy; 4386 4387 // If both operands are interfaces and either operand can be 4388 // assigned to the other, use that type as the composite 4389 // type. This allows 4390 // xxx ? (A*) a : (B*) b 4391 // where B is a subclass of A. 4392 // 4393 // Additionally, as for assignment, if either type is 'id' 4394 // allow silent coercion. Finally, if the types are 4395 // incompatible then make sure to use 'id' as the composite 4396 // type so the result is acceptable for sending messages to. 4397 4398 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4399 // It could return the composite type. 4400 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4401 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4402 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4403 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4404 } else if ((LHSTy->isObjCQualifiedIdType() || 4405 RHSTy->isObjCQualifiedIdType()) && 4406 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4407 // Need to handle "id<xx>" explicitly. 4408 // GCC allows qualified id and any Objective-C type to devolve to 4409 // id. Currently localizing to here until clear this should be 4410 // part of ObjCQualifiedIdTypesAreCompatible. 4411 compositeType = Context.getObjCIdType(); 4412 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4413 compositeType = Context.getObjCIdType(); 4414 } else if (!(compositeType = 4415 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4416 ; 4417 else { 4418 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4419 << LHSTy << RHSTy 4420 << LHS->getSourceRange() << RHS->getSourceRange(); 4421 QualType incompatTy = Context.getObjCIdType(); 4422 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4423 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4424 return incompatTy; 4425 } 4426 // The object pointer types are compatible. 4427 ImpCastExprToType(LHS, compositeType, CastExpr::CK_BitCast); 4428 ImpCastExprToType(RHS, compositeType, CastExpr::CK_BitCast); 4429 return compositeType; 4430 } 4431 // Check Objective-C object pointer types and 'void *' 4432 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4433 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4434 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4435 QualType destPointee 4436 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4437 QualType destType = Context.getPointerType(destPointee); 4438 // Add qualifiers if necessary. 4439 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4440 // Promote to void*. 4441 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4442 return destType; 4443 } 4444 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4445 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4446 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4447 QualType destPointee 4448 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4449 QualType destType = Context.getPointerType(destPointee); 4450 // Add qualifiers if necessary. 4451 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4452 // Promote to void*. 4453 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4454 return destType; 4455 } 4456 return QualType(); 4457} 4458 4459/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4460/// in the case of a the GNU conditional expr extension. 4461Action::OwningExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4462 SourceLocation ColonLoc, 4463 ExprArg Cond, ExprArg LHS, 4464 ExprArg RHS) { 4465 Expr *CondExpr = (Expr *) Cond.get(); 4466 Expr *LHSExpr = (Expr *) LHS.get(), *RHSExpr = (Expr *) RHS.get(); 4467 4468 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4469 // was the condition. 4470 bool isLHSNull = LHSExpr == 0; 4471 if (isLHSNull) 4472 LHSExpr = CondExpr; 4473 4474 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4475 RHSExpr, QuestionLoc); 4476 if (result.isNull()) 4477 return ExprError(); 4478 4479 Cond.release(); 4480 LHS.release(); 4481 RHS.release(); 4482 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4483 isLHSNull ? 0 : LHSExpr, 4484 ColonLoc, RHSExpr, result)); 4485} 4486 4487// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4488// being closely modeled after the C99 spec:-). The odd characteristic of this 4489// routine is it effectively iqnores the qualifiers on the top level pointee. 4490// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4491// FIXME: add a couple examples in this comment. 4492Sema::AssignConvertType 4493Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4494 QualType lhptee, rhptee; 4495 4496 if ((lhsType->isObjCClassType() && 4497 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4498 (rhsType->isObjCClassType() && 4499 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4500 return Compatible; 4501 } 4502 4503 // get the "pointed to" type (ignoring qualifiers at the top level) 4504 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4505 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4506 4507 // make sure we operate on the canonical type 4508 lhptee = Context.getCanonicalType(lhptee); 4509 rhptee = Context.getCanonicalType(rhptee); 4510 4511 AssignConvertType ConvTy = Compatible; 4512 4513 // C99 6.5.16.1p1: This following citation is common to constraints 4514 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4515 // qualifiers of the type *pointed to* by the right; 4516 // FIXME: Handle ExtQualType 4517 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4518 ConvTy = CompatiblePointerDiscardsQualifiers; 4519 4520 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4521 // incomplete type and the other is a pointer to a qualified or unqualified 4522 // version of void... 4523 if (lhptee->isVoidType()) { 4524 if (rhptee->isIncompleteOrObjectType()) 4525 return ConvTy; 4526 4527 // As an extension, we allow cast to/from void* to function pointer. 4528 assert(rhptee->isFunctionType()); 4529 return FunctionVoidPointer; 4530 } 4531 4532 if (rhptee->isVoidType()) { 4533 if (lhptee->isIncompleteOrObjectType()) 4534 return ConvTy; 4535 4536 // As an extension, we allow cast to/from void* to function pointer. 4537 assert(lhptee->isFunctionType()); 4538 return FunctionVoidPointer; 4539 } 4540 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4541 // unqualified versions of compatible types, ... 4542 lhptee = lhptee.getUnqualifiedType(); 4543 rhptee = rhptee.getUnqualifiedType(); 4544 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4545 // Check if the pointee types are compatible ignoring the sign. 4546 // We explicitly check for char so that we catch "char" vs 4547 // "unsigned char" on systems where "char" is unsigned. 4548 if (lhptee->isCharType()) 4549 lhptee = Context.UnsignedCharTy; 4550 else if (lhptee->isSignedIntegerType()) 4551 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4552 4553 if (rhptee->isCharType()) 4554 rhptee = Context.UnsignedCharTy; 4555 else if (rhptee->isSignedIntegerType()) 4556 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4557 4558 if (lhptee == rhptee) { 4559 // Types are compatible ignoring the sign. Qualifier incompatibility 4560 // takes priority over sign incompatibility because the sign 4561 // warning can be disabled. 4562 if (ConvTy != Compatible) 4563 return ConvTy; 4564 return IncompatiblePointerSign; 4565 } 4566 4567 // If we are a multi-level pointer, it's possible that our issue is simply 4568 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4569 // the eventual target type is the same and the pointers have the same 4570 // level of indirection, this must be the issue. 4571 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4572 do { 4573 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4574 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4575 4576 lhptee = Context.getCanonicalType(lhptee); 4577 rhptee = Context.getCanonicalType(rhptee); 4578 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4579 4580 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4581 return IncompatibleNestedPointerQualifiers; 4582 } 4583 4584 // General pointer incompatibility takes priority over qualifiers. 4585 return IncompatiblePointer; 4586 } 4587 return ConvTy; 4588} 4589 4590/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4591/// block pointer types are compatible or whether a block and normal pointer 4592/// are compatible. It is more restrict than comparing two function pointer 4593// types. 4594Sema::AssignConvertType 4595Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4596 QualType rhsType) { 4597 QualType lhptee, rhptee; 4598 4599 // get the "pointed to" type (ignoring qualifiers at the top level) 4600 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4601 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4602 4603 // make sure we operate on the canonical type 4604 lhptee = Context.getCanonicalType(lhptee); 4605 rhptee = Context.getCanonicalType(rhptee); 4606 4607 AssignConvertType ConvTy = Compatible; 4608 4609 // For blocks we enforce that qualifiers are identical. 4610 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4611 ConvTy = CompatiblePointerDiscardsQualifiers; 4612 4613 if (!getLangOptions().CPlusPlus) { 4614 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4615 return IncompatibleBlockPointer; 4616 } 4617 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4618 return IncompatibleBlockPointer; 4619 return ConvTy; 4620} 4621 4622/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4623/// for assignment compatibility. 4624Sema::AssignConvertType 4625Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4626 if (lhsType->isObjCBuiltinType()) { 4627 // Class is not compatible with ObjC object pointers. 4628 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4629 !rhsType->isObjCQualifiedClassType()) 4630 return IncompatiblePointer; 4631 return Compatible; 4632 } 4633 if (rhsType->isObjCBuiltinType()) { 4634 // Class is not compatible with ObjC object pointers. 4635 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4636 !lhsType->isObjCQualifiedClassType()) 4637 return IncompatiblePointer; 4638 return Compatible; 4639 } 4640 QualType lhptee = 4641 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4642 QualType rhptee = 4643 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4644 // make sure we operate on the canonical type 4645 lhptee = Context.getCanonicalType(lhptee); 4646 rhptee = Context.getCanonicalType(rhptee); 4647 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4648 return CompatiblePointerDiscardsQualifiers; 4649 4650 if (Context.typesAreCompatible(lhsType, rhsType)) 4651 return Compatible; 4652 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4653 return IncompatibleObjCQualifiedId; 4654 return IncompatiblePointer; 4655} 4656 4657/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4658/// has code to accommodate several GCC extensions when type checking 4659/// pointers. Here are some objectionable examples that GCC considers warnings: 4660/// 4661/// int a, *pint; 4662/// short *pshort; 4663/// struct foo *pfoo; 4664/// 4665/// pint = pshort; // warning: assignment from incompatible pointer type 4666/// a = pint; // warning: assignment makes integer from pointer without a cast 4667/// pint = a; // warning: assignment makes pointer from integer without a cast 4668/// pint = pfoo; // warning: assignment from incompatible pointer type 4669/// 4670/// As a result, the code for dealing with pointers is more complex than the 4671/// C99 spec dictates. 4672/// 4673Sema::AssignConvertType 4674Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4675 // Get canonical types. We're not formatting these types, just comparing 4676 // them. 4677 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4678 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4679 4680 if (lhsType == rhsType) 4681 return Compatible; // Common case: fast path an exact match. 4682 4683 if ((lhsType->isObjCClassType() && 4684 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4685 (rhsType->isObjCClassType() && 4686 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4687 return Compatible; 4688 } 4689 4690 // If the left-hand side is a reference type, then we are in a 4691 // (rare!) case where we've allowed the use of references in C, 4692 // e.g., as a parameter type in a built-in function. In this case, 4693 // just make sure that the type referenced is compatible with the 4694 // right-hand side type. The caller is responsible for adjusting 4695 // lhsType so that the resulting expression does not have reference 4696 // type. 4697 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4698 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4699 return Compatible; 4700 return Incompatible; 4701 } 4702 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4703 // to the same ExtVector type. 4704 if (lhsType->isExtVectorType()) { 4705 if (rhsType->isExtVectorType()) 4706 return lhsType == rhsType ? Compatible : Incompatible; 4707 if (rhsType->isArithmeticType()) 4708 return Compatible; 4709 } 4710 4711 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4712 // If we are allowing lax vector conversions, and LHS and RHS are both 4713 // vectors, the total size only needs to be the same. This is a bitcast; 4714 // no bits are changed but the result type is different. 4715 if (getLangOptions().LaxVectorConversions && 4716 lhsType->isVectorType() && rhsType->isVectorType()) { 4717 if (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType)) 4718 return IncompatibleVectors; 4719 } 4720 return Incompatible; 4721 } 4722 4723 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 4724 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) 4725 return Compatible; 4726 4727 if (isa<PointerType>(lhsType)) { 4728 if (rhsType->isIntegerType()) 4729 return IntToPointer; 4730 4731 if (isa<PointerType>(rhsType)) 4732 return CheckPointerTypesForAssignment(lhsType, rhsType); 4733 4734 // In general, C pointers are not compatible with ObjC object pointers. 4735 if (isa<ObjCObjectPointerType>(rhsType)) { 4736 if (lhsType->isVoidPointerType()) // an exception to the rule. 4737 return Compatible; 4738 return IncompatiblePointer; 4739 } 4740 if (rhsType->getAs<BlockPointerType>()) { 4741 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4742 return Compatible; 4743 4744 // Treat block pointers as objects. 4745 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4746 return Compatible; 4747 } 4748 return Incompatible; 4749 } 4750 4751 if (isa<BlockPointerType>(lhsType)) { 4752 if (rhsType->isIntegerType()) 4753 return IntToBlockPointer; 4754 4755 // Treat block pointers as objects. 4756 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4757 return Compatible; 4758 4759 if (rhsType->isBlockPointerType()) 4760 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4761 4762 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4763 if (RHSPT->getPointeeType()->isVoidType()) 4764 return Compatible; 4765 } 4766 return Incompatible; 4767 } 4768 4769 if (isa<ObjCObjectPointerType>(lhsType)) { 4770 if (rhsType->isIntegerType()) 4771 return IntToPointer; 4772 4773 // In general, C pointers are not compatible with ObjC object pointers. 4774 if (isa<PointerType>(rhsType)) { 4775 if (rhsType->isVoidPointerType()) // an exception to the rule. 4776 return Compatible; 4777 return IncompatiblePointer; 4778 } 4779 if (rhsType->isObjCObjectPointerType()) { 4780 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4781 } 4782 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4783 if (RHSPT->getPointeeType()->isVoidType()) 4784 return Compatible; 4785 } 4786 // Treat block pointers as objects. 4787 if (rhsType->isBlockPointerType()) 4788 return Compatible; 4789 return Incompatible; 4790 } 4791 if (isa<PointerType>(rhsType)) { 4792 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4793 if (lhsType == Context.BoolTy) 4794 return Compatible; 4795 4796 if (lhsType->isIntegerType()) 4797 return PointerToInt; 4798 4799 if (isa<PointerType>(lhsType)) 4800 return CheckPointerTypesForAssignment(lhsType, rhsType); 4801 4802 if (isa<BlockPointerType>(lhsType) && 4803 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4804 return Compatible; 4805 return Incompatible; 4806 } 4807 if (isa<ObjCObjectPointerType>(rhsType)) { 4808 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4809 if (lhsType == Context.BoolTy) 4810 return Compatible; 4811 4812 if (lhsType->isIntegerType()) 4813 return PointerToInt; 4814 4815 // In general, C pointers are not compatible with ObjC object pointers. 4816 if (isa<PointerType>(lhsType)) { 4817 if (lhsType->isVoidPointerType()) // an exception to the rule. 4818 return Compatible; 4819 return IncompatiblePointer; 4820 } 4821 if (isa<BlockPointerType>(lhsType) && 4822 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4823 return Compatible; 4824 return Incompatible; 4825 } 4826 4827 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4828 if (Context.typesAreCompatible(lhsType, rhsType)) 4829 return Compatible; 4830 } 4831 return Incompatible; 4832} 4833 4834/// \brief Constructs a transparent union from an expression that is 4835/// used to initialize the transparent union. 4836static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4837 QualType UnionType, FieldDecl *Field) { 4838 // Build an initializer list that designates the appropriate member 4839 // of the transparent union. 4840 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 4841 &E, 1, 4842 SourceLocation()); 4843 Initializer->setType(UnionType); 4844 Initializer->setInitializedFieldInUnion(Field); 4845 4846 // Build a compound literal constructing a value of the transparent 4847 // union type from this initializer list. 4848 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4849 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4850 Initializer, false); 4851} 4852 4853Sema::AssignConvertType 4854Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4855 QualType FromType = rExpr->getType(); 4856 4857 // If the ArgType is a Union type, we want to handle a potential 4858 // transparent_union GCC extension. 4859 const RecordType *UT = ArgType->getAsUnionType(); 4860 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4861 return Incompatible; 4862 4863 // The field to initialize within the transparent union. 4864 RecordDecl *UD = UT->getDecl(); 4865 FieldDecl *InitField = 0; 4866 // It's compatible if the expression matches any of the fields. 4867 for (RecordDecl::field_iterator it = UD->field_begin(), 4868 itend = UD->field_end(); 4869 it != itend; ++it) { 4870 if (it->getType()->isPointerType()) { 4871 // If the transparent union contains a pointer type, we allow: 4872 // 1) void pointer 4873 // 2) null pointer constant 4874 if (FromType->isPointerType()) 4875 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4876 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_BitCast); 4877 InitField = *it; 4878 break; 4879 } 4880 4881 if (rExpr->isNullPointerConstant(Context, 4882 Expr::NPC_ValueDependentIsNull)) { 4883 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_IntegralToPointer); 4884 InitField = *it; 4885 break; 4886 } 4887 } 4888 4889 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4890 == Compatible) { 4891 InitField = *it; 4892 break; 4893 } 4894 } 4895 4896 if (!InitField) 4897 return Incompatible; 4898 4899 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4900 return Compatible; 4901} 4902 4903Sema::AssignConvertType 4904Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4905 if (getLangOptions().CPlusPlus) { 4906 if (!lhsType->isRecordType()) { 4907 // C++ 5.17p3: If the left operand is not of class type, the 4908 // expression is implicitly converted (C++ 4) to the 4909 // cv-unqualified type of the left operand. 4910 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4911 AA_Assigning)) 4912 return Incompatible; 4913 return Compatible; 4914 } 4915 4916 // FIXME: Currently, we fall through and treat C++ classes like C 4917 // structures. 4918 } 4919 4920 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4921 // a null pointer constant. 4922 if ((lhsType->isPointerType() || 4923 lhsType->isObjCObjectPointerType() || 4924 lhsType->isBlockPointerType()) 4925 && rExpr->isNullPointerConstant(Context, 4926 Expr::NPC_ValueDependentIsNull)) { 4927 ImpCastExprToType(rExpr, lhsType, CastExpr::CK_Unknown); 4928 return Compatible; 4929 } 4930 4931 // This check seems unnatural, however it is necessary to ensure the proper 4932 // conversion of functions/arrays. If the conversion were done for all 4933 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4934 // expressions that surpress this implicit conversion (&, sizeof). 4935 // 4936 // Suppress this for references: C++ 8.5.3p5. 4937 if (!lhsType->isReferenceType()) 4938 DefaultFunctionArrayLvalueConversion(rExpr); 4939 4940 Sema::AssignConvertType result = 4941 CheckAssignmentConstraints(lhsType, rExpr->getType()); 4942 4943 // C99 6.5.16.1p2: The value of the right operand is converted to the 4944 // type of the assignment expression. 4945 // CheckAssignmentConstraints allows the left-hand side to be a reference, 4946 // so that we can use references in built-in functions even in C. 4947 // The getNonReferenceType() call makes sure that the resulting expression 4948 // does not have reference type. 4949 if (result != Incompatible && rExpr->getType() != lhsType) 4950 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), 4951 CastExpr::CK_Unknown); 4952 return result; 4953} 4954 4955QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4956 Diag(Loc, diag::err_typecheck_invalid_operands) 4957 << lex->getType() << rex->getType() 4958 << lex->getSourceRange() << rex->getSourceRange(); 4959 return QualType(); 4960} 4961 4962QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4963 // For conversion purposes, we ignore any qualifiers. 4964 // For example, "const float" and "float" are equivalent. 4965 QualType lhsType = 4966 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 4967 QualType rhsType = 4968 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 4969 4970 // If the vector types are identical, return. 4971 if (lhsType == rhsType) 4972 return lhsType; 4973 4974 // Handle the case of a vector & extvector type of the same size and element 4975 // type. It would be nice if we only had one vector type someday. 4976 if (getLangOptions().LaxVectorConversions) { 4977 // FIXME: Should we warn here? 4978 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 4979 if (const VectorType *RV = rhsType->getAs<VectorType>()) 4980 if (LV->getElementType() == RV->getElementType() && 4981 LV->getNumElements() == RV->getNumElements()) { 4982 if (lhsType->isExtVectorType()) { 4983 ImpCastExprToType(rex, lhsType, CastExpr::CK_BitCast); 4984 return lhsType; 4985 } 4986 4987 ImpCastExprToType(lex, rhsType, CastExpr::CK_BitCast); 4988 return rhsType; 4989 } 4990 } 4991 } 4992 4993 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 4994 // swap back (so that we don't reverse the inputs to a subtract, for instance. 4995 bool swapped = false; 4996 if (rhsType->isExtVectorType()) { 4997 swapped = true; 4998 std::swap(rex, lex); 4999 std::swap(rhsType, lhsType); 5000 } 5001 5002 // Handle the case of an ext vector and scalar. 5003 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5004 QualType EltTy = LV->getElementType(); 5005 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5006 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5007 ImpCastExprToType(rex, lhsType, CastExpr::CK_IntegralCast); 5008 if (swapped) std::swap(rex, lex); 5009 return lhsType; 5010 } 5011 } 5012 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5013 rhsType->isRealFloatingType()) { 5014 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5015 ImpCastExprToType(rex, lhsType, CastExpr::CK_FloatingCast); 5016 if (swapped) std::swap(rex, lex); 5017 return lhsType; 5018 } 5019 } 5020 } 5021 5022 // Vectors of different size or scalar and non-ext-vector are errors. 5023 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5024 << lex->getType() << rex->getType() 5025 << lex->getSourceRange() << rex->getSourceRange(); 5026 return QualType(); 5027} 5028 5029QualType Sema::CheckMultiplyDivideOperands( 5030 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5031 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5032 return CheckVectorOperands(Loc, lex, rex); 5033 5034 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5035 5036 if (!lex->getType()->isArithmeticType() || 5037 !rex->getType()->isArithmeticType()) 5038 return InvalidOperands(Loc, lex, rex); 5039 5040 // Check for division by zero. 5041 if (isDiv && 5042 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5043 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5044 << rex->getSourceRange()); 5045 5046 return compType; 5047} 5048 5049QualType Sema::CheckRemainderOperands( 5050 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5051 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5052 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5053 return CheckVectorOperands(Loc, lex, rex); 5054 return InvalidOperands(Loc, lex, rex); 5055 } 5056 5057 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5058 5059 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5060 return InvalidOperands(Loc, lex, rex); 5061 5062 // Check for remainder by zero. 5063 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5064 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5065 << rex->getSourceRange()); 5066 5067 return compType; 5068} 5069 5070QualType Sema::CheckAdditionOperands( // C99 6.5.6 5071 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5072 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5073 QualType compType = CheckVectorOperands(Loc, lex, rex); 5074 if (CompLHSTy) *CompLHSTy = compType; 5075 return compType; 5076 } 5077 5078 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5079 5080 // handle the common case first (both operands are arithmetic). 5081 if (lex->getType()->isArithmeticType() && 5082 rex->getType()->isArithmeticType()) { 5083 if (CompLHSTy) *CompLHSTy = compType; 5084 return compType; 5085 } 5086 5087 // Put any potential pointer into PExp 5088 Expr* PExp = lex, *IExp = rex; 5089 if (IExp->getType()->isAnyPointerType()) 5090 std::swap(PExp, IExp); 5091 5092 if (PExp->getType()->isAnyPointerType()) { 5093 5094 if (IExp->getType()->isIntegerType()) { 5095 QualType PointeeTy = PExp->getType()->getPointeeType(); 5096 5097 // Check for arithmetic on pointers to incomplete types. 5098 if (PointeeTy->isVoidType()) { 5099 if (getLangOptions().CPlusPlus) { 5100 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5101 << lex->getSourceRange() << rex->getSourceRange(); 5102 return QualType(); 5103 } 5104 5105 // GNU extension: arithmetic on pointer to void 5106 Diag(Loc, diag::ext_gnu_void_ptr) 5107 << lex->getSourceRange() << rex->getSourceRange(); 5108 } else if (PointeeTy->isFunctionType()) { 5109 if (getLangOptions().CPlusPlus) { 5110 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5111 << lex->getType() << lex->getSourceRange(); 5112 return QualType(); 5113 } 5114 5115 // GNU extension: arithmetic on pointer to function 5116 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5117 << lex->getType() << lex->getSourceRange(); 5118 } else { 5119 // Check if we require a complete type. 5120 if (((PExp->getType()->isPointerType() && 5121 !PExp->getType()->isDependentType()) || 5122 PExp->getType()->isObjCObjectPointerType()) && 5123 RequireCompleteType(Loc, PointeeTy, 5124 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5125 << PExp->getSourceRange() 5126 << PExp->getType())) 5127 return QualType(); 5128 } 5129 // Diagnose bad cases where we step over interface counts. 5130 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5131 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5132 << PointeeTy << PExp->getSourceRange(); 5133 return QualType(); 5134 } 5135 5136 if (CompLHSTy) { 5137 QualType LHSTy = Context.isPromotableBitField(lex); 5138 if (LHSTy.isNull()) { 5139 LHSTy = lex->getType(); 5140 if (LHSTy->isPromotableIntegerType()) 5141 LHSTy = Context.getPromotedIntegerType(LHSTy); 5142 } 5143 *CompLHSTy = LHSTy; 5144 } 5145 return PExp->getType(); 5146 } 5147 } 5148 5149 return InvalidOperands(Loc, lex, rex); 5150} 5151 5152// C99 6.5.6 5153QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5154 SourceLocation Loc, QualType* CompLHSTy) { 5155 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5156 QualType compType = CheckVectorOperands(Loc, lex, rex); 5157 if (CompLHSTy) *CompLHSTy = compType; 5158 return compType; 5159 } 5160 5161 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5162 5163 // Enforce type constraints: C99 6.5.6p3. 5164 5165 // Handle the common case first (both operands are arithmetic). 5166 if (lex->getType()->isArithmeticType() 5167 && rex->getType()->isArithmeticType()) { 5168 if (CompLHSTy) *CompLHSTy = compType; 5169 return compType; 5170 } 5171 5172 // Either ptr - int or ptr - ptr. 5173 if (lex->getType()->isAnyPointerType()) { 5174 QualType lpointee = lex->getType()->getPointeeType(); 5175 5176 // The LHS must be an completely-defined object type. 5177 5178 bool ComplainAboutVoid = false; 5179 Expr *ComplainAboutFunc = 0; 5180 if (lpointee->isVoidType()) { 5181 if (getLangOptions().CPlusPlus) { 5182 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5183 << lex->getSourceRange() << rex->getSourceRange(); 5184 return QualType(); 5185 } 5186 5187 // GNU C extension: arithmetic on pointer to void 5188 ComplainAboutVoid = true; 5189 } else if (lpointee->isFunctionType()) { 5190 if (getLangOptions().CPlusPlus) { 5191 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5192 << lex->getType() << lex->getSourceRange(); 5193 return QualType(); 5194 } 5195 5196 // GNU C extension: arithmetic on pointer to function 5197 ComplainAboutFunc = lex; 5198 } else if (!lpointee->isDependentType() && 5199 RequireCompleteType(Loc, lpointee, 5200 PDiag(diag::err_typecheck_sub_ptr_object) 5201 << lex->getSourceRange() 5202 << lex->getType())) 5203 return QualType(); 5204 5205 // Diagnose bad cases where we step over interface counts. 5206 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5207 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5208 << lpointee << lex->getSourceRange(); 5209 return QualType(); 5210 } 5211 5212 // The result type of a pointer-int computation is the pointer type. 5213 if (rex->getType()->isIntegerType()) { 5214 if (ComplainAboutVoid) 5215 Diag(Loc, diag::ext_gnu_void_ptr) 5216 << lex->getSourceRange() << rex->getSourceRange(); 5217 if (ComplainAboutFunc) 5218 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5219 << ComplainAboutFunc->getType() 5220 << ComplainAboutFunc->getSourceRange(); 5221 5222 if (CompLHSTy) *CompLHSTy = lex->getType(); 5223 return lex->getType(); 5224 } 5225 5226 // Handle pointer-pointer subtractions. 5227 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5228 QualType rpointee = RHSPTy->getPointeeType(); 5229 5230 // RHS must be a completely-type object type. 5231 // Handle the GNU void* extension. 5232 if (rpointee->isVoidType()) { 5233 if (getLangOptions().CPlusPlus) { 5234 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5235 << lex->getSourceRange() << rex->getSourceRange(); 5236 return QualType(); 5237 } 5238 5239 ComplainAboutVoid = true; 5240 } else if (rpointee->isFunctionType()) { 5241 if (getLangOptions().CPlusPlus) { 5242 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5243 << rex->getType() << rex->getSourceRange(); 5244 return QualType(); 5245 } 5246 5247 // GNU extension: arithmetic on pointer to function 5248 if (!ComplainAboutFunc) 5249 ComplainAboutFunc = rex; 5250 } else if (!rpointee->isDependentType() && 5251 RequireCompleteType(Loc, rpointee, 5252 PDiag(diag::err_typecheck_sub_ptr_object) 5253 << rex->getSourceRange() 5254 << rex->getType())) 5255 return QualType(); 5256 5257 if (getLangOptions().CPlusPlus) { 5258 // Pointee types must be the same: C++ [expr.add] 5259 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5260 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5261 << lex->getType() << rex->getType() 5262 << lex->getSourceRange() << rex->getSourceRange(); 5263 return QualType(); 5264 } 5265 } else { 5266 // Pointee types must be compatible C99 6.5.6p3 5267 if (!Context.typesAreCompatible( 5268 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5269 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5270 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5271 << lex->getType() << rex->getType() 5272 << lex->getSourceRange() << rex->getSourceRange(); 5273 return QualType(); 5274 } 5275 } 5276 5277 if (ComplainAboutVoid) 5278 Diag(Loc, diag::ext_gnu_void_ptr) 5279 << lex->getSourceRange() << rex->getSourceRange(); 5280 if (ComplainAboutFunc) 5281 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5282 << ComplainAboutFunc->getType() 5283 << ComplainAboutFunc->getSourceRange(); 5284 5285 if (CompLHSTy) *CompLHSTy = lex->getType(); 5286 return Context.getPointerDiffType(); 5287 } 5288 } 5289 5290 return InvalidOperands(Loc, lex, rex); 5291} 5292 5293// C99 6.5.7 5294QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5295 bool isCompAssign) { 5296 // C99 6.5.7p2: Each of the operands shall have integer type. 5297 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5298 return InvalidOperands(Loc, lex, rex); 5299 5300 // Vector shifts promote their scalar inputs to vector type. 5301 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5302 return CheckVectorOperands(Loc, lex, rex); 5303 5304 // Shifts don't perform usual arithmetic conversions, they just do integer 5305 // promotions on each operand. C99 6.5.7p3 5306 QualType LHSTy = Context.isPromotableBitField(lex); 5307 if (LHSTy.isNull()) { 5308 LHSTy = lex->getType(); 5309 if (LHSTy->isPromotableIntegerType()) 5310 LHSTy = Context.getPromotedIntegerType(LHSTy); 5311 } 5312 if (!isCompAssign) 5313 ImpCastExprToType(lex, LHSTy, CastExpr::CK_IntegralCast); 5314 5315 UsualUnaryConversions(rex); 5316 5317 // Sanity-check shift operands 5318 llvm::APSInt Right; 5319 // Check right/shifter operand 5320 if (!rex->isValueDependent() && 5321 rex->isIntegerConstantExpr(Right, Context)) { 5322 if (Right.isNegative()) 5323 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5324 else { 5325 llvm::APInt LeftBits(Right.getBitWidth(), 5326 Context.getTypeSize(lex->getType())); 5327 if (Right.uge(LeftBits)) 5328 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5329 } 5330 } 5331 5332 // "The type of the result is that of the promoted left operand." 5333 return LHSTy; 5334} 5335 5336static bool IsWithinTemplateSpecialization(Decl *D) { 5337 if (DeclContext *DC = D->getDeclContext()) { 5338 if (isa<ClassTemplateSpecializationDecl>(DC)) 5339 return true; 5340 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 5341 return FD->isFunctionTemplateSpecialization(); 5342 } 5343 return false; 5344} 5345 5346// C99 6.5.8, C++ [expr.rel] 5347QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5348 unsigned OpaqueOpc, bool isRelational) { 5349 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)OpaqueOpc; 5350 5351 // Handle vector comparisons separately. 5352 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5353 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5354 5355 QualType lType = lex->getType(); 5356 QualType rType = rex->getType(); 5357 5358 if (!lType->hasFloatingRepresentation() && 5359 !(lType->isBlockPointerType() && isRelational)) { 5360 // For non-floating point types, check for self-comparisons of the form 5361 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5362 // often indicate logic errors in the program. 5363 // 5364 // NOTE: Don't warn about comparison expressions resulting from macro 5365 // expansion. Also don't warn about comparisons which are only self 5366 // comparisons within a template specialization. The warnings should catch 5367 // obvious cases in the definition of the template anyways. The idea is to 5368 // warn when the typed comparison operator will always evaluate to the same 5369 // result. 5370 Expr *LHSStripped = lex->IgnoreParens(); 5371 Expr *RHSStripped = rex->IgnoreParens(); 5372 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 5373 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 5374 if (DRL->getDecl() == DRR->getDecl() && !Loc.isMacroID() && 5375 !IsWithinTemplateSpecialization(DRL->getDecl())) { 5376 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5377 << 0 // self- 5378 << (Opc == BinaryOperator::EQ 5379 || Opc == BinaryOperator::LE 5380 || Opc == BinaryOperator::GE)); 5381 } else if (lType->isArrayType() && rType->isArrayType() && 5382 !DRL->getDecl()->getType()->isReferenceType() && 5383 !DRR->getDecl()->getType()->isReferenceType()) { 5384 // what is it always going to eval to? 5385 char always_evals_to; 5386 switch(Opc) { 5387 case BinaryOperator::EQ: // e.g. array1 == array2 5388 always_evals_to = 0; // false 5389 break; 5390 case BinaryOperator::NE: // e.g. array1 != array2 5391 always_evals_to = 1; // true 5392 break; 5393 default: 5394 // best we can say is 'a constant' 5395 always_evals_to = 2; // e.g. array1 <= array2 5396 break; 5397 } 5398 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5399 << 1 // array 5400 << always_evals_to); 5401 } 5402 } 5403 } 5404 5405 if (isa<CastExpr>(LHSStripped)) 5406 LHSStripped = LHSStripped->IgnoreParenCasts(); 5407 if (isa<CastExpr>(RHSStripped)) 5408 RHSStripped = RHSStripped->IgnoreParenCasts(); 5409 5410 // Warn about comparisons against a string constant (unless the other 5411 // operand is null), the user probably wants strcmp. 5412 Expr *literalString = 0; 5413 Expr *literalStringStripped = 0; 5414 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5415 !RHSStripped->isNullPointerConstant(Context, 5416 Expr::NPC_ValueDependentIsNull)) { 5417 literalString = lex; 5418 literalStringStripped = LHSStripped; 5419 } else if ((isa<StringLiteral>(RHSStripped) || 5420 isa<ObjCEncodeExpr>(RHSStripped)) && 5421 !LHSStripped->isNullPointerConstant(Context, 5422 Expr::NPC_ValueDependentIsNull)) { 5423 literalString = rex; 5424 literalStringStripped = RHSStripped; 5425 } 5426 5427 if (literalString) { 5428 std::string resultComparison; 5429 switch (Opc) { 5430 case BinaryOperator::LT: resultComparison = ") < 0"; break; 5431 case BinaryOperator::GT: resultComparison = ") > 0"; break; 5432 case BinaryOperator::LE: resultComparison = ") <= 0"; break; 5433 case BinaryOperator::GE: resultComparison = ") >= 0"; break; 5434 case BinaryOperator::EQ: resultComparison = ") == 0"; break; 5435 case BinaryOperator::NE: resultComparison = ") != 0"; break; 5436 default: assert(false && "Invalid comparison operator"); 5437 } 5438 5439 DiagRuntimeBehavior(Loc, 5440 PDiag(diag::warn_stringcompare) 5441 << isa<ObjCEncodeExpr>(literalStringStripped) 5442 << literalString->getSourceRange()); 5443 } 5444 } 5445 5446 // C99 6.5.8p3 / C99 6.5.9p4 5447 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5448 UsualArithmeticConversions(lex, rex); 5449 else { 5450 UsualUnaryConversions(lex); 5451 UsualUnaryConversions(rex); 5452 } 5453 5454 lType = lex->getType(); 5455 rType = rex->getType(); 5456 5457 // The result of comparisons is 'bool' in C++, 'int' in C. 5458 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5459 5460 if (isRelational) { 5461 if (lType->isRealType() && rType->isRealType()) 5462 return ResultTy; 5463 } else { 5464 // Check for comparisons of floating point operands using != and ==. 5465 if (lType->hasFloatingRepresentation()) 5466 CheckFloatComparison(Loc,lex,rex); 5467 5468 if (lType->isArithmeticType() && rType->isArithmeticType()) 5469 return ResultTy; 5470 } 5471 5472 bool LHSIsNull = lex->isNullPointerConstant(Context, 5473 Expr::NPC_ValueDependentIsNull); 5474 bool RHSIsNull = rex->isNullPointerConstant(Context, 5475 Expr::NPC_ValueDependentIsNull); 5476 5477 // All of the following pointer-related warnings are GCC extensions, except 5478 // when handling null pointer constants. 5479 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5480 QualType LCanPointeeTy = 5481 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5482 QualType RCanPointeeTy = 5483 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5484 5485 if (getLangOptions().CPlusPlus) { 5486 if (LCanPointeeTy == RCanPointeeTy) 5487 return ResultTy; 5488 if (!isRelational && 5489 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5490 // Valid unless comparison between non-null pointer and function pointer 5491 // This is a gcc extension compatibility comparison. 5492 // In a SFINAE context, we treat this as a hard error to maintain 5493 // conformance with the C++ standard. 5494 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5495 && !LHSIsNull && !RHSIsNull) { 5496 Diag(Loc, 5497 isSFINAEContext()? 5498 diag::err_typecheck_comparison_of_fptr_to_void 5499 : diag::ext_typecheck_comparison_of_fptr_to_void) 5500 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5501 5502 if (isSFINAEContext()) 5503 return QualType(); 5504 5505 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5506 return ResultTy; 5507 } 5508 } 5509 // C++ [expr.rel]p2: 5510 // [...] Pointer conversions (4.10) and qualification 5511 // conversions (4.4) are performed on pointer operands (or on 5512 // a pointer operand and a null pointer constant) to bring 5513 // them to their composite pointer type. [...] 5514 // 5515 // C++ [expr.eq]p1 uses the same notion for (in)equality 5516 // comparisons of pointers. 5517 bool NonStandardCompositeType = false; 5518 QualType T = FindCompositePointerType(Loc, lex, rex, 5519 isSFINAEContext()? 0 : &NonStandardCompositeType); 5520 if (T.isNull()) { 5521 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5522 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5523 return QualType(); 5524 } else if (NonStandardCompositeType) { 5525 Diag(Loc, 5526 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5527 << lType << rType << T 5528 << lex->getSourceRange() << rex->getSourceRange(); 5529 } 5530 5531 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5532 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5533 return ResultTy; 5534 } 5535 // C99 6.5.9p2 and C99 6.5.8p2 5536 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5537 RCanPointeeTy.getUnqualifiedType())) { 5538 // Valid unless a relational comparison of function pointers 5539 if (isRelational && LCanPointeeTy->isFunctionType()) { 5540 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5541 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5542 } 5543 } else if (!isRelational && 5544 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5545 // Valid unless comparison between non-null pointer and function pointer 5546 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5547 && !LHSIsNull && !RHSIsNull) { 5548 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5549 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5550 } 5551 } else { 5552 // Invalid 5553 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5554 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5555 } 5556 if (LCanPointeeTy != RCanPointeeTy) 5557 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5558 return ResultTy; 5559 } 5560 5561 if (getLangOptions().CPlusPlus) { 5562 // Comparison of pointers with null pointer constants and equality 5563 // comparisons of member pointers to null pointer constants. 5564 if (RHSIsNull && 5565 (lType->isPointerType() || 5566 (!isRelational && lType->isMemberPointerType()))) { 5567 ImpCastExprToType(rex, lType, CastExpr::CK_NullToMemberPointer); 5568 return ResultTy; 5569 } 5570 if (LHSIsNull && 5571 (rType->isPointerType() || 5572 (!isRelational && rType->isMemberPointerType()))) { 5573 ImpCastExprToType(lex, rType, CastExpr::CK_NullToMemberPointer); 5574 return ResultTy; 5575 } 5576 5577 // Comparison of member pointers. 5578 if (!isRelational && 5579 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5580 // C++ [expr.eq]p2: 5581 // In addition, pointers to members can be compared, or a pointer to 5582 // member and a null pointer constant. Pointer to member conversions 5583 // (4.11) and qualification conversions (4.4) are performed to bring 5584 // them to a common type. If one operand is a null pointer constant, 5585 // the common type is the type of the other operand. Otherwise, the 5586 // common type is a pointer to member type similar (4.4) to the type 5587 // of one of the operands, with a cv-qualification signature (4.4) 5588 // that is the union of the cv-qualification signatures of the operand 5589 // types. 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, CastExpr::CK_BitCast); 5605 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5606 return ResultTy; 5607 } 5608 5609 // Comparison of nullptr_t with itself. 5610 if (lType->isNullPtrType() && rType->isNullPtrType()) 5611 return ResultTy; 5612 } 5613 5614 // Handle block pointer types. 5615 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5616 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5617 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5618 5619 if (!LHSIsNull && !RHSIsNull && 5620 !Context.typesAreCompatible(lpointee, rpointee)) { 5621 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5622 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5623 } 5624 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5625 return ResultTy; 5626 } 5627 // Allow block pointers to be compared with null pointer constants. 5628 if (!isRelational 5629 && ((lType->isBlockPointerType() && rType->isPointerType()) 5630 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5631 if (!LHSIsNull && !RHSIsNull) { 5632 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5633 ->getPointeeType()->isVoidType()) 5634 || (lType->isPointerType() && lType->getAs<PointerType>() 5635 ->getPointeeType()->isVoidType()))) 5636 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5637 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5638 } 5639 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5640 return ResultTy; 5641 } 5642 5643 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5644 if (lType->isPointerType() || rType->isPointerType()) { 5645 const PointerType *LPT = lType->getAs<PointerType>(); 5646 const PointerType *RPT = rType->getAs<PointerType>(); 5647 bool LPtrToVoid = LPT ? 5648 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5649 bool RPtrToVoid = RPT ? 5650 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5651 5652 if (!LPtrToVoid && !RPtrToVoid && 5653 !Context.typesAreCompatible(lType, rType)) { 5654 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5655 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5656 } 5657 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5658 return ResultTy; 5659 } 5660 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5661 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5662 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5663 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5664 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5665 return ResultTy; 5666 } 5667 } 5668 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 5669 (lType->isIntegerType() && rType->isAnyPointerType())) { 5670 unsigned DiagID = 0; 5671 bool isError = false; 5672 if ((LHSIsNull && lType->isIntegerType()) || 5673 (RHSIsNull && rType->isIntegerType())) { 5674 if (isRelational && !getLangOptions().CPlusPlus) 5675 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5676 } else if (isRelational && !getLangOptions().CPlusPlus) 5677 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5678 else if (getLangOptions().CPlusPlus) { 5679 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 5680 isError = true; 5681 } else 5682 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5683 5684 if (DiagID) { 5685 Diag(Loc, DiagID) 5686 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5687 if (isError) 5688 return QualType(); 5689 } 5690 5691 if (lType->isIntegerType()) 5692 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5693 else 5694 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5695 return ResultTy; 5696 } 5697 5698 // Handle block pointers. 5699 if (!isRelational && RHSIsNull 5700 && lType->isBlockPointerType() && rType->isIntegerType()) { 5701 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5702 return ResultTy; 5703 } 5704 if (!isRelational && LHSIsNull 5705 && lType->isIntegerType() && rType->isBlockPointerType()) { 5706 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5707 return ResultTy; 5708 } 5709 return InvalidOperands(Loc, lex, rex); 5710} 5711 5712/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5713/// operates on extended vector types. Instead of producing an IntTy result, 5714/// like a scalar comparison, a vector comparison produces a vector of integer 5715/// types. 5716QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5717 SourceLocation Loc, 5718 bool isRelational) { 5719 // Check to make sure we're operating on vectors of the same type and width, 5720 // Allowing one side to be a scalar of element type. 5721 QualType vType = CheckVectorOperands(Loc, lex, rex); 5722 if (vType.isNull()) 5723 return vType; 5724 5725 QualType lType = lex->getType(); 5726 QualType rType = rex->getType(); 5727 5728 // For non-floating point types, check for self-comparisons of the form 5729 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5730 // often indicate logic errors in the program. 5731 if (!lType->hasFloatingRepresentation()) { 5732 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5733 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5734 if (DRL->getDecl() == DRR->getDecl()) 5735 DiagRuntimeBehavior(Loc, 5736 PDiag(diag::warn_comparison_always) 5737 << 0 // self- 5738 << 2 // "a constant" 5739 ); 5740 } 5741 5742 // Check for comparisons of floating point operands using != and ==. 5743 if (!isRelational && lType->hasFloatingRepresentation()) { 5744 assert (rType->hasFloatingRepresentation()); 5745 CheckFloatComparison(Loc,lex,rex); 5746 } 5747 5748 // Return the type for the comparison, which is the same as vector type for 5749 // integer vectors, or an integer type of identical size and number of 5750 // elements for floating point vectors. 5751 if (lType->isIntegerType()) 5752 return lType; 5753 5754 const VectorType *VTy = lType->getAs<VectorType>(); 5755 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5756 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5757 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5758 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5759 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5760 5761 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5762 "Unhandled vector element size in vector compare"); 5763 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5764} 5765 5766inline QualType Sema::CheckBitwiseOperands( 5767 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5768 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5769 return CheckVectorOperands(Loc, lex, rex); 5770 5771 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5772 5773 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5774 return compType; 5775 return InvalidOperands(Loc, lex, rex); 5776} 5777 5778inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5779 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 5780 5781 // Diagnose cases where the user write a logical and/or but probably meant a 5782 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 5783 // is a constant. 5784 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 5785 rex->getType()->isIntegerType() && rex->isEvaluatable(Context) && 5786 // Don't warn if the RHS is a (constant folded) boolean expression like 5787 // "sizeof(int) == 4". 5788 !rex->isKnownToHaveBooleanValue() && 5789 // Don't warn in macros. 5790 !Loc.isMacroID()) 5791 Diag(Loc, diag::warn_logical_instead_of_bitwise) 5792 << rex->getSourceRange() 5793 << (Opc == BinaryOperator::LAnd ? "&&" : "||") 5794 << (Opc == BinaryOperator::LAnd ? "&" : "|"); 5795 5796 5797 5798 if (!Context.getLangOptions().CPlusPlus) { 5799 UsualUnaryConversions(lex); 5800 UsualUnaryConversions(rex); 5801 5802 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5803 return InvalidOperands(Loc, lex, rex); 5804 5805 return Context.IntTy; 5806 } 5807 5808 // The following is safe because we only use this method for 5809 // non-overloadable operands. 5810 5811 // C++ [expr.log.and]p1 5812 // C++ [expr.log.or]p1 5813 // The operands are both contextually converted to type bool. 5814 if (PerformContextuallyConvertToBool(lex) || 5815 PerformContextuallyConvertToBool(rex)) 5816 return InvalidOperands(Loc, lex, rex); 5817 5818 // C++ [expr.log.and]p2 5819 // C++ [expr.log.or]p2 5820 // The result is a bool. 5821 return Context.BoolTy; 5822} 5823 5824/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5825/// is a read-only property; return true if so. A readonly property expression 5826/// depends on various declarations and thus must be treated specially. 5827/// 5828static bool IsReadonlyProperty(Expr *E, Sema &S) { 5829 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5830 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5831 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5832 QualType BaseType = PropExpr->getBase()->getType(); 5833 if (const ObjCObjectPointerType *OPT = 5834 BaseType->getAsObjCInterfacePointerType()) 5835 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5836 if (S.isPropertyReadonly(PDecl, IFace)) 5837 return true; 5838 } 5839 } 5840 return false; 5841} 5842 5843/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5844/// emit an error and return true. If so, return false. 5845static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5846 SourceLocation OrigLoc = Loc; 5847 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5848 &Loc); 5849 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5850 IsLV = Expr::MLV_ReadonlyProperty; 5851 if (IsLV == Expr::MLV_Valid) 5852 return false; 5853 5854 unsigned Diag = 0; 5855 bool NeedType = false; 5856 switch (IsLV) { // C99 6.5.16p2 5857 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5858 case Expr::MLV_ArrayType: 5859 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5860 NeedType = true; 5861 break; 5862 case Expr::MLV_NotObjectType: 5863 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5864 NeedType = true; 5865 break; 5866 case Expr::MLV_LValueCast: 5867 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5868 break; 5869 case Expr::MLV_Valid: 5870 llvm_unreachable("did not take early return for MLV_Valid"); 5871 case Expr::MLV_InvalidExpression: 5872 case Expr::MLV_MemberFunction: 5873 case Expr::MLV_ClassTemporary: 5874 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5875 break; 5876 case Expr::MLV_IncompleteType: 5877 case Expr::MLV_IncompleteVoidType: 5878 return S.RequireCompleteType(Loc, E->getType(), 5879 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5880 << E->getSourceRange()); 5881 case Expr::MLV_DuplicateVectorComponents: 5882 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5883 break; 5884 case Expr::MLV_NotBlockQualified: 5885 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5886 break; 5887 case Expr::MLV_ReadonlyProperty: 5888 Diag = diag::error_readonly_property_assignment; 5889 break; 5890 case Expr::MLV_NoSetterProperty: 5891 Diag = diag::error_nosetter_property_assignment; 5892 break; 5893 case Expr::MLV_SubObjCPropertySetting: 5894 Diag = diag::error_no_subobject_property_setting; 5895 break; 5896 } 5897 5898 SourceRange Assign; 5899 if (Loc != OrigLoc) 5900 Assign = SourceRange(OrigLoc, OrigLoc); 5901 if (NeedType) 5902 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5903 else 5904 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5905 return true; 5906} 5907 5908 5909 5910// C99 6.5.16.1 5911QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5912 SourceLocation Loc, 5913 QualType CompoundType) { 5914 // Verify that LHS is a modifiable lvalue, and emit error if not. 5915 if (CheckForModifiableLvalue(LHS, Loc, *this)) 5916 return QualType(); 5917 5918 QualType LHSType = LHS->getType(); 5919 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 5920 AssignConvertType ConvTy; 5921 if (CompoundType.isNull()) { 5922 QualType LHSTy(LHSType); 5923 // Simple assignment "x = y". 5924 if (const ObjCImplicitSetterGetterRefExpr *OISGE = 5925 dyn_cast<ObjCImplicitSetterGetterRefExpr>(LHS)) { 5926 // If using property-dot syntax notation for assignment, and there is a 5927 // setter, RHS expression is being passed to the setter argument. So, 5928 // type conversion (and comparison) is RHS to setter's argument type. 5929 if (const ObjCMethodDecl *SetterMD = OISGE->getSetterMethod()) { 5930 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 5931 LHSTy = (*P)->getType(); 5932 } 5933 } 5934 5935 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 5936 // Special case of NSObject attributes on c-style pointer types. 5937 if (ConvTy == IncompatiblePointer && 5938 ((Context.isObjCNSObjectType(LHSType) && 5939 RHSType->isObjCObjectPointerType()) || 5940 (Context.isObjCNSObjectType(RHSType) && 5941 LHSType->isObjCObjectPointerType()))) 5942 ConvTy = Compatible; 5943 5944 // If the RHS is a unary plus or minus, check to see if they = and + are 5945 // right next to each other. If so, the user may have typo'd "x =+ 4" 5946 // instead of "x += 4". 5947 Expr *RHSCheck = RHS; 5948 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 5949 RHSCheck = ICE->getSubExpr(); 5950 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 5951 if ((UO->getOpcode() == UnaryOperator::Plus || 5952 UO->getOpcode() == UnaryOperator::Minus) && 5953 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 5954 // Only if the two operators are exactly adjacent. 5955 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 5956 // And there is a space or other character before the subexpr of the 5957 // unary +/-. We don't want to warn on "x=-1". 5958 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 5959 UO->getSubExpr()->getLocStart().isFileID()) { 5960 Diag(Loc, diag::warn_not_compound_assign) 5961 << (UO->getOpcode() == UnaryOperator::Plus ? "+" : "-") 5962 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 5963 } 5964 } 5965 } else { 5966 // Compound assignment "x += y" 5967 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 5968 } 5969 5970 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 5971 RHS, AA_Assigning)) 5972 return QualType(); 5973 5974 5975 // Check to see if the destination operand is a dereferenced null pointer. If 5976 // so, and if not volatile-qualified, this is undefined behavior that the 5977 // optimizer will delete, so warn about it. People sometimes try to use this 5978 // to get a deterministic trap and are surprised by clang's behavior. This 5979 // only handles the pattern "*null = whatever", which is a very syntactic 5980 // check. 5981 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 5982 if (UO->getOpcode() == UnaryOperator::Deref && 5983 UO->getSubExpr()->IgnoreParenCasts()-> 5984 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 5985 !UO->getType().isVolatileQualified()) { 5986 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 5987 << UO->getSubExpr()->getSourceRange(); 5988 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 5989 } 5990 5991 // C99 6.5.16p3: The type of an assignment expression is the type of the 5992 // left operand unless the left operand has qualified type, in which case 5993 // it is the unqualified version of the type of the left operand. 5994 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 5995 // is converted to the type of the assignment expression (above). 5996 // C++ 5.17p1: the type of the assignment expression is that of its left 5997 // operand. 5998 return LHSType.getUnqualifiedType(); 5999} 6000 6001// C99 6.5.17 6002QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 6003 DiagnoseUnusedExprResult(LHS); 6004 6005 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 6006 // C++ does not perform this conversion (C++ [expr.comma]p1). 6007 if (!getLangOptions().CPlusPlus) 6008 DefaultFunctionArrayLvalueConversion(RHS); 6009 6010 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 6011 // incomplete in C++). 6012 6013 return RHS->getType(); 6014} 6015 6016/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 6017/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 6018QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 6019 bool isInc, bool isPrefix) { 6020 if (Op->isTypeDependent()) 6021 return Context.DependentTy; 6022 6023 QualType ResType = Op->getType(); 6024 assert(!ResType.isNull() && "no type for increment/decrement expression"); 6025 6026 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 6027 // Decrement of bool is not allowed. 6028 if (!isInc) { 6029 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 6030 return QualType(); 6031 } 6032 // Increment of bool sets it to true, but is deprecated. 6033 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 6034 } else if (ResType->isRealType()) { 6035 // OK! 6036 } else if (ResType->isAnyPointerType()) { 6037 QualType PointeeTy = ResType->getPointeeType(); 6038 6039 // C99 6.5.2.4p2, 6.5.6p2 6040 if (PointeeTy->isVoidType()) { 6041 if (getLangOptions().CPlusPlus) { 6042 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 6043 << Op->getSourceRange(); 6044 return QualType(); 6045 } 6046 6047 // Pointer to void is a GNU extension in C. 6048 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 6049 } else if (PointeeTy->isFunctionType()) { 6050 if (getLangOptions().CPlusPlus) { 6051 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 6052 << Op->getType() << Op->getSourceRange(); 6053 return QualType(); 6054 } 6055 6056 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 6057 << ResType << Op->getSourceRange(); 6058 } else if (RequireCompleteType(OpLoc, PointeeTy, 6059 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6060 << Op->getSourceRange() 6061 << ResType)) 6062 return QualType(); 6063 // Diagnose bad cases where we step over interface counts. 6064 else if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6065 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6066 << PointeeTy << Op->getSourceRange(); 6067 return QualType(); 6068 } 6069 } else if (ResType->isAnyComplexType()) { 6070 // C99 does not support ++/-- on complex types, we allow as an extension. 6071 Diag(OpLoc, diag::ext_integer_increment_complex) 6072 << ResType << Op->getSourceRange(); 6073 } else { 6074 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6075 << ResType << int(isInc) << Op->getSourceRange(); 6076 return QualType(); 6077 } 6078 // At this point, we know we have a real, complex or pointer type. 6079 // Now make sure the operand is a modifiable lvalue. 6080 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6081 return QualType(); 6082 // In C++, a prefix increment is the same type as the operand. Otherwise 6083 // (in C or with postfix), the increment is the unqualified type of the 6084 // operand. 6085 return isPrefix && getLangOptions().CPlusPlus 6086 ? ResType : ResType.getUnqualifiedType(); 6087} 6088 6089/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6090/// This routine allows us to typecheck complex/recursive expressions 6091/// where the declaration is needed for type checking. We only need to 6092/// handle cases when the expression references a function designator 6093/// or is an lvalue. Here are some examples: 6094/// - &(x) => x 6095/// - &*****f => f for f a function designator. 6096/// - &s.xx => s 6097/// - &s.zz[1].yy -> s, if zz is an array 6098/// - *(x + 1) -> x, if x is an array 6099/// - &"123"[2] -> 0 6100/// - & __real__ x -> x 6101static NamedDecl *getPrimaryDecl(Expr *E) { 6102 switch (E->getStmtClass()) { 6103 case Stmt::DeclRefExprClass: 6104 return cast<DeclRefExpr>(E)->getDecl(); 6105 case Stmt::MemberExprClass: 6106 // If this is an arrow operator, the address is an offset from 6107 // the base's value, so the object the base refers to is 6108 // irrelevant. 6109 if (cast<MemberExpr>(E)->isArrow()) 6110 return 0; 6111 // Otherwise, the expression refers to a part of the base 6112 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6113 case Stmt::ArraySubscriptExprClass: { 6114 // FIXME: This code shouldn't be necessary! We should catch the implicit 6115 // promotion of register arrays earlier. 6116 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6117 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6118 if (ICE->getSubExpr()->getType()->isArrayType()) 6119 return getPrimaryDecl(ICE->getSubExpr()); 6120 } 6121 return 0; 6122 } 6123 case Stmt::UnaryOperatorClass: { 6124 UnaryOperator *UO = cast<UnaryOperator>(E); 6125 6126 switch(UO->getOpcode()) { 6127 case UnaryOperator::Real: 6128 case UnaryOperator::Imag: 6129 case UnaryOperator::Extension: 6130 return getPrimaryDecl(UO->getSubExpr()); 6131 default: 6132 return 0; 6133 } 6134 } 6135 case Stmt::ParenExprClass: 6136 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6137 case Stmt::ImplicitCastExprClass: 6138 // If the result of an implicit cast is an l-value, we care about 6139 // the sub-expression; otherwise, the result here doesn't matter. 6140 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6141 default: 6142 return 0; 6143 } 6144} 6145 6146/// CheckAddressOfOperand - The operand of & must be either a function 6147/// designator or an lvalue designating an object. If it is an lvalue, the 6148/// object cannot be declared with storage class register or be a bit field. 6149/// Note: The usual conversions are *not* applied to the operand of the & 6150/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6151/// In C++, the operand might be an overloaded function name, in which case 6152/// we allow the '&' but retain the overloaded-function type. 6153QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) { 6154 // Make sure to ignore parentheses in subsequent checks 6155 op = op->IgnoreParens(); 6156 6157 if (op->isTypeDependent()) 6158 return Context.DependentTy; 6159 6160 if (getLangOptions().C99) { 6161 // Implement C99-only parts of addressof rules. 6162 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6163 if (uOp->getOpcode() == UnaryOperator::Deref) 6164 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6165 // (assuming the deref expression is valid). 6166 return uOp->getSubExpr()->getType(); 6167 } 6168 // Technically, there should be a check for array subscript 6169 // expressions here, but the result of one is always an lvalue anyway. 6170 } 6171 NamedDecl *dcl = getPrimaryDecl(op); 6172 Expr::isLvalueResult lval = op->isLvalue(Context); 6173 6174 MemberExpr *ME = dyn_cast<MemberExpr>(op); 6175 if (lval == Expr::LV_MemberFunction && ME && 6176 isa<CXXMethodDecl>(ME->getMemberDecl())) { 6177 ValueDecl *dcl = cast<MemberExpr>(op)->getMemberDecl(); 6178 // &f where f is a member of the current object, or &o.f, or &p->f 6179 // All these are not allowed, and we need to catch them before the dcl 6180 // branch of the if, below. 6181 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6182 << dcl; 6183 // FIXME: Improve this diagnostic and provide a fixit. 6184 6185 // Now recover by acting as if the function had been accessed qualified. 6186 return Context.getMemberPointerType(op->getType(), 6187 Context.getTypeDeclType(cast<RecordDecl>(dcl->getDeclContext())) 6188 .getTypePtr()); 6189 } 6190 6191 if (lval == Expr::LV_ClassTemporary) { 6192 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6193 : diag::ext_typecheck_addrof_class_temporary) 6194 << op->getType() << op->getSourceRange(); 6195 if (isSFINAEContext()) 6196 return QualType(); 6197 } else if (isa<ObjCSelectorExpr>(op)) 6198 return Context.getPointerType(op->getType()); 6199 else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6200 // C99 6.5.3.2p1 6201 // The operand must be either an l-value or a function designator 6202 if (!op->getType()->isFunctionType()) { 6203 // FIXME: emit more specific diag... 6204 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6205 << op->getSourceRange(); 6206 return QualType(); 6207 } 6208 } else if (op->getBitField()) { // C99 6.5.3.2p1 6209 // The operand cannot be a bit-field 6210 Diag(OpLoc, diag::err_typecheck_address_of) 6211 << "bit-field" << op->getSourceRange(); 6212 return QualType(); 6213 } else if (op->refersToVectorElement()) { 6214 // The operand cannot be an element of a vector 6215 Diag(OpLoc, diag::err_typecheck_address_of) 6216 << "vector element" << op->getSourceRange(); 6217 return QualType(); 6218 } else if (isa<ObjCPropertyRefExpr>(op)) { 6219 // cannot take address of a property expression. 6220 Diag(OpLoc, diag::err_typecheck_address_of) 6221 << "property expression" << op->getSourceRange(); 6222 return QualType(); 6223 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6224 // FIXME: Can LHS ever be null here? 6225 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6226 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6227 } else if (isa<UnresolvedLookupExpr>(op)) { 6228 return Context.OverloadTy; 6229 } else if (dcl) { // C99 6.5.3.2p1 6230 // We have an lvalue with a decl. Make sure the decl is not declared 6231 // with the register storage-class specifier. 6232 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6233 if (vd->getStorageClass() == VarDecl::Register) { 6234 Diag(OpLoc, diag::err_typecheck_address_of) 6235 << "register variable" << op->getSourceRange(); 6236 return QualType(); 6237 } 6238 } else if (isa<FunctionTemplateDecl>(dcl)) { 6239 return Context.OverloadTy; 6240 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6241 // Okay: we can take the address of a field. 6242 // Could be a pointer to member, though, if there is an explicit 6243 // scope qualifier for the class. 6244 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6245 DeclContext *Ctx = dcl->getDeclContext(); 6246 if (Ctx && Ctx->isRecord()) { 6247 if (FD->getType()->isReferenceType()) { 6248 Diag(OpLoc, 6249 diag::err_cannot_form_pointer_to_member_of_reference_type) 6250 << FD->getDeclName() << FD->getType(); 6251 return QualType(); 6252 } 6253 6254 return Context.getMemberPointerType(op->getType(), 6255 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6256 } 6257 } 6258 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(dcl)) { 6259 // Okay: we can take the address of a function. 6260 // As above. 6261 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier() && 6262 MD->isInstance()) 6263 return Context.getMemberPointerType(op->getType(), 6264 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6265 } else if (!isa<FunctionDecl>(dcl)) 6266 assert(0 && "Unknown/unexpected decl type"); 6267 } 6268 6269 if (lval == Expr::LV_IncompleteVoidType) { 6270 // Taking the address of a void variable is technically illegal, but we 6271 // allow it in cases which are otherwise valid. 6272 // Example: "extern void x; void* y = &x;". 6273 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6274 } 6275 6276 // If the operand has type "type", the result has type "pointer to type". 6277 return Context.getPointerType(op->getType()); 6278} 6279 6280/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 6281QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6282 if (Op->isTypeDependent()) 6283 return Context.DependentTy; 6284 6285 UsualUnaryConversions(Op); 6286 QualType OpTy = Op->getType(); 6287 QualType Result; 6288 6289 // Note that per both C89 and C99, indirection is always legal, even if OpTy 6290 // is an incomplete type or void. It would be possible to warn about 6291 // dereferencing a void pointer, but it's completely well-defined, and such a 6292 // warning is unlikely to catch any mistakes. 6293 if (const PointerType *PT = OpTy->getAs<PointerType>()) 6294 Result = PT->getPointeeType(); 6295 else if (const ObjCObjectPointerType *OPT = 6296 OpTy->getAs<ObjCObjectPointerType>()) 6297 Result = OPT->getPointeeType(); 6298 6299 if (Result.isNull()) { 6300 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6301 << OpTy << Op->getSourceRange(); 6302 return QualType(); 6303 } 6304 6305 return Result; 6306} 6307 6308static inline BinaryOperator::Opcode ConvertTokenKindToBinaryOpcode( 6309 tok::TokenKind Kind) { 6310 BinaryOperator::Opcode Opc; 6311 switch (Kind) { 6312 default: assert(0 && "Unknown binop!"); 6313 case tok::periodstar: Opc = BinaryOperator::PtrMemD; break; 6314 case tok::arrowstar: Opc = BinaryOperator::PtrMemI; break; 6315 case tok::star: Opc = BinaryOperator::Mul; break; 6316 case tok::slash: Opc = BinaryOperator::Div; break; 6317 case tok::percent: Opc = BinaryOperator::Rem; break; 6318 case tok::plus: Opc = BinaryOperator::Add; break; 6319 case tok::minus: Opc = BinaryOperator::Sub; break; 6320 case tok::lessless: Opc = BinaryOperator::Shl; break; 6321 case tok::greatergreater: Opc = BinaryOperator::Shr; break; 6322 case tok::lessequal: Opc = BinaryOperator::LE; break; 6323 case tok::less: Opc = BinaryOperator::LT; break; 6324 case tok::greaterequal: Opc = BinaryOperator::GE; break; 6325 case tok::greater: Opc = BinaryOperator::GT; break; 6326 case tok::exclaimequal: Opc = BinaryOperator::NE; break; 6327 case tok::equalequal: Opc = BinaryOperator::EQ; break; 6328 case tok::amp: Opc = BinaryOperator::And; break; 6329 case tok::caret: Opc = BinaryOperator::Xor; break; 6330 case tok::pipe: Opc = BinaryOperator::Or; break; 6331 case tok::ampamp: Opc = BinaryOperator::LAnd; break; 6332 case tok::pipepipe: Opc = BinaryOperator::LOr; break; 6333 case tok::equal: Opc = BinaryOperator::Assign; break; 6334 case tok::starequal: Opc = BinaryOperator::MulAssign; break; 6335 case tok::slashequal: Opc = BinaryOperator::DivAssign; break; 6336 case tok::percentequal: Opc = BinaryOperator::RemAssign; break; 6337 case tok::plusequal: Opc = BinaryOperator::AddAssign; break; 6338 case tok::minusequal: Opc = BinaryOperator::SubAssign; break; 6339 case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break; 6340 case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break; 6341 case tok::ampequal: Opc = BinaryOperator::AndAssign; break; 6342 case tok::caretequal: Opc = BinaryOperator::XorAssign; break; 6343 case tok::pipeequal: Opc = BinaryOperator::OrAssign; break; 6344 case tok::comma: Opc = BinaryOperator::Comma; break; 6345 } 6346 return Opc; 6347} 6348 6349static inline UnaryOperator::Opcode ConvertTokenKindToUnaryOpcode( 6350 tok::TokenKind Kind) { 6351 UnaryOperator::Opcode Opc; 6352 switch (Kind) { 6353 default: assert(0 && "Unknown unary op!"); 6354 case tok::plusplus: Opc = UnaryOperator::PreInc; break; 6355 case tok::minusminus: Opc = UnaryOperator::PreDec; break; 6356 case tok::amp: Opc = UnaryOperator::AddrOf; break; 6357 case tok::star: Opc = UnaryOperator::Deref; break; 6358 case tok::plus: Opc = UnaryOperator::Plus; break; 6359 case tok::minus: Opc = UnaryOperator::Minus; break; 6360 case tok::tilde: Opc = UnaryOperator::Not; break; 6361 case tok::exclaim: Opc = UnaryOperator::LNot; break; 6362 case tok::kw___real: Opc = UnaryOperator::Real; break; 6363 case tok::kw___imag: Opc = UnaryOperator::Imag; break; 6364 case tok::kw___extension__: Opc = UnaryOperator::Extension; break; 6365 } 6366 return Opc; 6367} 6368 6369/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6370/// operator @p Opc at location @c TokLoc. This routine only supports 6371/// built-in operations; ActOnBinOp handles overloaded operators. 6372Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6373 unsigned Op, 6374 Expr *lhs, Expr *rhs) { 6375 QualType ResultTy; // Result type of the binary operator. 6376 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)Op; 6377 // The following two variables are used for compound assignment operators 6378 QualType CompLHSTy; // Type of LHS after promotions for computation 6379 QualType CompResultTy; // Type of computation result 6380 6381 switch (Opc) { 6382 case BinaryOperator::Assign: 6383 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6384 break; 6385 case BinaryOperator::PtrMemD: 6386 case BinaryOperator::PtrMemI: 6387 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6388 Opc == BinaryOperator::PtrMemI); 6389 break; 6390 case BinaryOperator::Mul: 6391 case BinaryOperator::Div: 6392 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6393 Opc == BinaryOperator::Div); 6394 break; 6395 case BinaryOperator::Rem: 6396 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6397 break; 6398 case BinaryOperator::Add: 6399 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6400 break; 6401 case BinaryOperator::Sub: 6402 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6403 break; 6404 case BinaryOperator::Shl: 6405 case BinaryOperator::Shr: 6406 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6407 break; 6408 case BinaryOperator::LE: 6409 case BinaryOperator::LT: 6410 case BinaryOperator::GE: 6411 case BinaryOperator::GT: 6412 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6413 break; 6414 case BinaryOperator::EQ: 6415 case BinaryOperator::NE: 6416 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6417 break; 6418 case BinaryOperator::And: 6419 case BinaryOperator::Xor: 6420 case BinaryOperator::Or: 6421 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6422 break; 6423 case BinaryOperator::LAnd: 6424 case BinaryOperator::LOr: 6425 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 6426 break; 6427 case BinaryOperator::MulAssign: 6428 case BinaryOperator::DivAssign: 6429 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6430 Opc == BinaryOperator::DivAssign); 6431 CompLHSTy = CompResultTy; 6432 if (!CompResultTy.isNull()) 6433 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6434 break; 6435 case BinaryOperator::RemAssign: 6436 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6437 CompLHSTy = CompResultTy; 6438 if (!CompResultTy.isNull()) 6439 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6440 break; 6441 case BinaryOperator::AddAssign: 6442 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6443 if (!CompResultTy.isNull()) 6444 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6445 break; 6446 case BinaryOperator::SubAssign: 6447 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6448 if (!CompResultTy.isNull()) 6449 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6450 break; 6451 case BinaryOperator::ShlAssign: 6452 case BinaryOperator::ShrAssign: 6453 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6454 CompLHSTy = CompResultTy; 6455 if (!CompResultTy.isNull()) 6456 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6457 break; 6458 case BinaryOperator::AndAssign: 6459 case BinaryOperator::XorAssign: 6460 case BinaryOperator::OrAssign: 6461 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6462 CompLHSTy = CompResultTy; 6463 if (!CompResultTy.isNull()) 6464 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6465 break; 6466 case BinaryOperator::Comma: 6467 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6468 break; 6469 } 6470 if (ResultTy.isNull()) 6471 return ExprError(); 6472 if (CompResultTy.isNull()) 6473 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6474 else 6475 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6476 CompLHSTy, CompResultTy, 6477 OpLoc)); 6478} 6479 6480/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6481/// ParenRange in parentheses. 6482static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6483 const PartialDiagnostic &PD, 6484 const PartialDiagnostic &FirstNote, 6485 SourceRange FirstParenRange, 6486 const PartialDiagnostic &SecondNote, 6487 SourceRange SecondParenRange) { 6488 Self.Diag(Loc, PD); 6489 6490 if (!FirstNote.getDiagID()) 6491 return; 6492 6493 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 6494 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6495 // We can't display the parentheses, so just return. 6496 return; 6497 } 6498 6499 Self.Diag(Loc, FirstNote) 6500 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 6501 << FixItHint::CreateInsertion(EndLoc, ")"); 6502 6503 if (!SecondNote.getDiagID()) 6504 return; 6505 6506 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6507 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6508 // We can't display the parentheses, so just dig the 6509 // warning/error and return. 6510 Self.Diag(Loc, SecondNote); 6511 return; 6512 } 6513 6514 Self.Diag(Loc, SecondNote) 6515 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6516 << FixItHint::CreateInsertion(EndLoc, ")"); 6517} 6518 6519/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6520/// operators are mixed in a way that suggests that the programmer forgot that 6521/// comparison operators have higher precedence. The most typical example of 6522/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6523static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6524 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6525 typedef BinaryOperator BinOp; 6526 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6527 rhsopc = static_cast<BinOp::Opcode>(-1); 6528 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6529 lhsopc = BO->getOpcode(); 6530 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6531 rhsopc = BO->getOpcode(); 6532 6533 // Subs are not binary operators. 6534 if (lhsopc == -1 && rhsopc == -1) 6535 return; 6536 6537 // Bitwise operations are sometimes used as eager logical ops. 6538 // Don't diagnose this. 6539 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6540 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6541 return; 6542 6543 if (BinOp::isComparisonOp(lhsopc)) 6544 SuggestParentheses(Self, OpLoc, 6545 Self.PDiag(diag::warn_precedence_bitwise_rel) 6546 << SourceRange(lhs->getLocStart(), OpLoc) 6547 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6548 Self.PDiag(diag::note_precedence_bitwise_first) 6549 << BinOp::getOpcodeStr(Opc), 6550 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 6551 Self.PDiag(diag::note_precedence_bitwise_silence) 6552 << BinOp::getOpcodeStr(lhsopc), 6553 lhs->getSourceRange()); 6554 else if (BinOp::isComparisonOp(rhsopc)) 6555 SuggestParentheses(Self, OpLoc, 6556 Self.PDiag(diag::warn_precedence_bitwise_rel) 6557 << SourceRange(OpLoc, rhs->getLocEnd()) 6558 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6559 Self.PDiag(diag::note_precedence_bitwise_first) 6560 << BinOp::getOpcodeStr(Opc), 6561 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 6562 Self.PDiag(diag::note_precedence_bitwise_silence) 6563 << BinOp::getOpcodeStr(rhsopc), 6564 rhs->getSourceRange()); 6565} 6566 6567/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6568/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6569/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6570static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6571 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6572 if (BinaryOperator::isBitwiseOp(Opc)) 6573 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6574} 6575 6576// Binary Operators. 'Tok' is the token for the operator. 6577Action::OwningExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6578 tok::TokenKind Kind, 6579 ExprArg LHS, ExprArg RHS) { 6580 BinaryOperator::Opcode Opc = ConvertTokenKindToBinaryOpcode(Kind); 6581 Expr *lhs = LHS.takeAs<Expr>(), *rhs = RHS.takeAs<Expr>(); 6582 6583 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6584 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6585 6586 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6587 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6588 6589 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6590} 6591 6592Action::OwningExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6593 BinaryOperator::Opcode Opc, 6594 Expr *lhs, Expr *rhs) { 6595 if (getLangOptions().CPlusPlus && 6596 (lhs->getType()->isOverloadableType() || 6597 rhs->getType()->isOverloadableType())) { 6598 // Find all of the overloaded operators visible from this 6599 // point. We perform both an operator-name lookup from the local 6600 // scope and an argument-dependent lookup based on the types of 6601 // the arguments. 6602 UnresolvedSet<16> Functions; 6603 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6604 if (S && OverOp != OO_None) 6605 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6606 Functions); 6607 6608 // Build the (potentially-overloaded, potentially-dependent) 6609 // binary operation. 6610 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6611 } 6612 6613 // Build a built-in binary operation. 6614 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6615} 6616 6617Action::OwningExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6618 unsigned OpcIn, 6619 ExprArg InputArg) { 6620 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6621 6622 // FIXME: Input is modified below, but InputArg is not updated appropriately. 6623 Expr *Input = (Expr *)InputArg.get(); 6624 QualType resultType; 6625 switch (Opc) { 6626 case UnaryOperator::OffsetOf: 6627 assert(false && "Invalid unary operator"); 6628 break; 6629 6630 case UnaryOperator::PreInc: 6631 case UnaryOperator::PreDec: 6632 case UnaryOperator::PostInc: 6633 case UnaryOperator::PostDec: 6634 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6635 Opc == UnaryOperator::PreInc || 6636 Opc == UnaryOperator::PostInc, 6637 Opc == UnaryOperator::PreInc || 6638 Opc == UnaryOperator::PreDec); 6639 break; 6640 case UnaryOperator::AddrOf: 6641 resultType = CheckAddressOfOperand(Input, OpLoc); 6642 break; 6643 case UnaryOperator::Deref: 6644 DefaultFunctionArrayLvalueConversion(Input); 6645 resultType = CheckIndirectionOperand(Input, OpLoc); 6646 break; 6647 case UnaryOperator::Plus: 6648 case UnaryOperator::Minus: 6649 UsualUnaryConversions(Input); 6650 resultType = Input->getType(); 6651 if (resultType->isDependentType()) 6652 break; 6653 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 6654 resultType->isVectorType()) 6655 break; 6656 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6657 resultType->isEnumeralType()) 6658 break; 6659 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6660 Opc == UnaryOperator::Plus && 6661 resultType->isPointerType()) 6662 break; 6663 6664 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6665 << resultType << Input->getSourceRange()); 6666 case UnaryOperator::Not: // bitwise complement 6667 UsualUnaryConversions(Input); 6668 resultType = Input->getType(); 6669 if (resultType->isDependentType()) 6670 break; 6671 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6672 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6673 // C99 does not support '~' for complex conjugation. 6674 Diag(OpLoc, diag::ext_integer_complement_complex) 6675 << resultType << Input->getSourceRange(); 6676 else if (!resultType->isIntegerType()) 6677 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6678 << resultType << Input->getSourceRange()); 6679 break; 6680 case UnaryOperator::LNot: // logical negation 6681 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6682 DefaultFunctionArrayLvalueConversion(Input); 6683 resultType = Input->getType(); 6684 if (resultType->isDependentType()) 6685 break; 6686 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6687 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6688 << resultType << Input->getSourceRange()); 6689 // LNot always has type int. C99 6.5.3.3p5. 6690 // In C++, it's bool. C++ 5.3.1p8 6691 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6692 break; 6693 case UnaryOperator::Real: 6694 case UnaryOperator::Imag: 6695 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UnaryOperator::Real); 6696 break; 6697 case UnaryOperator::Extension: 6698 resultType = Input->getType(); 6699 break; 6700 } 6701 if (resultType.isNull()) 6702 return ExprError(); 6703 6704 InputArg.release(); 6705 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6706} 6707 6708Action::OwningExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6709 UnaryOperator::Opcode Opc, 6710 ExprArg input) { 6711 Expr *Input = (Expr*)input.get(); 6712 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6713 Opc != UnaryOperator::Extension) { 6714 // Find all of the overloaded operators visible from this 6715 // point. We perform both an operator-name lookup from the local 6716 // scope and an argument-dependent lookup based on the types of 6717 // the arguments. 6718 UnresolvedSet<16> Functions; 6719 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6720 if (S && OverOp != OO_None) 6721 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6722 Functions); 6723 6724 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, move(input)); 6725 } 6726 6727 return CreateBuiltinUnaryOp(OpLoc, Opc, move(input)); 6728} 6729 6730// Unary Operators. 'Tok' is the token for the operator. 6731Action::OwningExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6732 tok::TokenKind Op, ExprArg input) { 6733 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), move(input)); 6734} 6735 6736/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6737Sema::OwningExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6738 SourceLocation LabLoc, 6739 IdentifierInfo *LabelII) { 6740 // Look up the record for this label identifier. 6741 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 6742 6743 // If we haven't seen this label yet, create a forward reference. It 6744 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6745 if (LabelDecl == 0) 6746 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6747 6748 // Create the AST node. The address of a label always has type 'void*'. 6749 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6750 Context.getPointerType(Context.VoidTy))); 6751} 6752 6753Sema::OwningExprResult 6754Sema::ActOnStmtExpr(SourceLocation LPLoc, StmtArg substmt, 6755 SourceLocation RPLoc) { // "({..})" 6756 Stmt *SubStmt = static_cast<Stmt*>(substmt.get()); 6757 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6758 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6759 6760 bool isFileScope 6761 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6762 if (isFileScope) 6763 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6764 6765 // FIXME: there are a variety of strange constraints to enforce here, for 6766 // example, it is not possible to goto into a stmt expression apparently. 6767 // More semantic analysis is needed. 6768 6769 // If there are sub stmts in the compound stmt, take the type of the last one 6770 // as the type of the stmtexpr. 6771 QualType Ty = Context.VoidTy; 6772 6773 if (!Compound->body_empty()) { 6774 Stmt *LastStmt = Compound->body_back(); 6775 // If LastStmt is a label, skip down through into the body. 6776 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6777 LastStmt = Label->getSubStmt(); 6778 6779 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6780 Ty = LastExpr->getType(); 6781 } 6782 6783 // FIXME: Check that expression type is complete/non-abstract; statement 6784 // expressions are not lvalues. 6785 6786 substmt.release(); 6787 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6788} 6789 6790Sema::OwningExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 6791 TypeSourceInfo *TInfo, 6792 OffsetOfComponent *CompPtr, 6793 unsigned NumComponents, 6794 SourceLocation RParenLoc) { 6795 QualType ArgTy = TInfo->getType(); 6796 bool Dependent = ArgTy->isDependentType(); 6797 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 6798 6799 // We must have at least one component that refers to the type, and the first 6800 // one is known to be a field designator. Verify that the ArgTy represents 6801 // a struct/union/class. 6802 if (!Dependent && !ArgTy->isRecordType()) 6803 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 6804 << ArgTy << TypeRange); 6805 6806 // Type must be complete per C99 7.17p3 because a declaring a variable 6807 // with an incomplete type would be ill-formed. 6808 if (!Dependent 6809 && RequireCompleteType(BuiltinLoc, ArgTy, 6810 PDiag(diag::err_offsetof_incomplete_type) 6811 << TypeRange)) 6812 return ExprError(); 6813 6814 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6815 // GCC extension, diagnose them. 6816 // FIXME: This diagnostic isn't actually visible because the location is in 6817 // a system header! 6818 if (NumComponents != 1) 6819 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6820 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6821 6822 bool DidWarnAboutNonPOD = false; 6823 QualType CurrentType = ArgTy; 6824 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 6825 llvm::SmallVector<OffsetOfNode, 4> Comps; 6826 llvm::SmallVector<Expr*, 4> Exprs; 6827 for (unsigned i = 0; i != NumComponents; ++i) { 6828 const OffsetOfComponent &OC = CompPtr[i]; 6829 if (OC.isBrackets) { 6830 // Offset of an array sub-field. TODO: Should we allow vector elements? 6831 if (!CurrentType->isDependentType()) { 6832 const ArrayType *AT = Context.getAsArrayType(CurrentType); 6833 if(!AT) 6834 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6835 << CurrentType); 6836 CurrentType = AT->getElementType(); 6837 } else 6838 CurrentType = Context.DependentTy; 6839 6840 // The expression must be an integral expression. 6841 // FIXME: An integral constant expression? 6842 Expr *Idx = static_cast<Expr*>(OC.U.E); 6843 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 6844 !Idx->getType()->isIntegerType()) 6845 return ExprError(Diag(Idx->getLocStart(), 6846 diag::err_typecheck_subscript_not_integer) 6847 << Idx->getSourceRange()); 6848 6849 // Record this array index. 6850 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 6851 Exprs.push_back(Idx); 6852 continue; 6853 } 6854 6855 // Offset of a field. 6856 if (CurrentType->isDependentType()) { 6857 // We have the offset of a field, but we can't look into the dependent 6858 // type. Just record the identifier of the field. 6859 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 6860 CurrentType = Context.DependentTy; 6861 continue; 6862 } 6863 6864 // We need to have a complete type to look into. 6865 if (RequireCompleteType(OC.LocStart, CurrentType, 6866 diag::err_offsetof_incomplete_type)) 6867 return ExprError(); 6868 6869 // Look for the designated field. 6870 const RecordType *RC = CurrentType->getAs<RecordType>(); 6871 if (!RC) 6872 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6873 << CurrentType); 6874 RecordDecl *RD = RC->getDecl(); 6875 6876 // C++ [lib.support.types]p5: 6877 // The macro offsetof accepts a restricted set of type arguments in this 6878 // International Standard. type shall be a POD structure or a POD union 6879 // (clause 9). 6880 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6881 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6882 DiagRuntimeBehavior(BuiltinLoc, 6883 PDiag(diag::warn_offsetof_non_pod_type) 6884 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6885 << CurrentType)) 6886 DidWarnAboutNonPOD = true; 6887 } 6888 6889 // Look for the field. 6890 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6891 LookupQualifiedName(R, RD); 6892 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6893 if (!MemberDecl) 6894 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6895 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 6896 OC.LocEnd)); 6897 6898 // C99 7.17p3: 6899 // (If the specified member is a bit-field, the behavior is undefined.) 6900 // 6901 // We diagnose this as an error. 6902 if (MemberDecl->getBitWidth()) { 6903 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 6904 << MemberDecl->getDeclName() 6905 << SourceRange(BuiltinLoc, RParenLoc); 6906 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 6907 return ExprError(); 6908 } 6909 6910 // If the member was found in a base class, introduce OffsetOfNodes for 6911 // the base class indirections. 6912 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 6913 /*DetectVirtual=*/false); 6914 if (IsDerivedFrom(CurrentType, 6915 Context.getTypeDeclType(MemberDecl->getParent()), 6916 Paths)) { 6917 CXXBasePath &Path = Paths.front(); 6918 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 6919 B != BEnd; ++B) 6920 Comps.push_back(OffsetOfNode(B->Base)); 6921 } 6922 6923 if (cast<RecordDecl>(MemberDecl->getDeclContext())-> 6924 isAnonymousStructOrUnion()) { 6925 llvm::SmallVector<FieldDecl*, 4> Path; 6926 BuildAnonymousStructUnionMemberPath(MemberDecl, Path); 6927 unsigned n = Path.size(); 6928 for (int j = n - 1; j > -1; --j) 6929 Comps.push_back(OffsetOfNode(OC.LocStart, Path[j], OC.LocEnd)); 6930 } else { 6931 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 6932 } 6933 CurrentType = MemberDecl->getType().getNonReferenceType(); 6934 } 6935 6936 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 6937 TInfo, Comps.data(), Comps.size(), 6938 Exprs.data(), Exprs.size(), RParenLoc)); 6939} 6940 6941Sema::OwningExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 6942 SourceLocation BuiltinLoc, 6943 SourceLocation TypeLoc, 6944 TypeTy *argty, 6945 OffsetOfComponent *CompPtr, 6946 unsigned NumComponents, 6947 SourceLocation RPLoc) { 6948 6949 TypeSourceInfo *ArgTInfo; 6950 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 6951 if (ArgTy.isNull()) 6952 return ExprError(); 6953 6954 if (getLangOptions().CPlusPlus) { 6955 if (!ArgTInfo) 6956 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 6957 6958 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 6959 RPLoc); 6960 } 6961 6962 // FIXME: The code below is marked for death, once we have proper CodeGen 6963 // support for non-constant OffsetOf expressions. 6964 6965 bool Dependent = ArgTy->isDependentType(); 6966 6967 // We must have at least one component that refers to the type, and the first 6968 // one is known to be a field designator. Verify that the ArgTy represents 6969 // a struct/union/class. 6970 if (!Dependent && !ArgTy->isRecordType()) 6971 return ExprError(Diag(TypeLoc, diag::err_offsetof_record_type) << ArgTy); 6972 6973 // FIXME: Type must be complete per C99 7.17p3 because a declaring a variable 6974 // with an incomplete type would be illegal. 6975 6976 // Otherwise, create a null pointer as the base, and iteratively process 6977 // the offsetof designators. 6978 QualType ArgTyPtr = Context.getPointerType(ArgTy); 6979 Expr* Res = new (Context) ImplicitValueInitExpr(ArgTyPtr); 6980 Res = new (Context) UnaryOperator(Res, UnaryOperator::Deref, 6981 ArgTy, SourceLocation()); 6982 6983 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6984 // GCC extension, diagnose them. 6985 // FIXME: This diagnostic isn't actually visible because the location is in 6986 // a system header! 6987 if (NumComponents != 1) 6988 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6989 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6990 6991 if (!Dependent) { 6992 bool DidWarnAboutNonPOD = false; 6993 6994 if (RequireCompleteType(TypeLoc, Res->getType(), 6995 diag::err_offsetof_incomplete_type)) 6996 return ExprError(); 6997 6998 // FIXME: Dependent case loses a lot of information here. And probably 6999 // leaks like a sieve. 7000 for (unsigned i = 0; i != NumComponents; ++i) { 7001 const OffsetOfComponent &OC = CompPtr[i]; 7002 if (OC.isBrackets) { 7003 // Offset of an array sub-field. TODO: Should we allow vector elements? 7004 const ArrayType *AT = Context.getAsArrayType(Res->getType()); 7005 if (!AT) { 7006 Res->Destroy(Context); 7007 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 7008 << Res->getType()); 7009 } 7010 7011 // FIXME: C++: Verify that operator[] isn't overloaded. 7012 7013 // Promote the array so it looks more like a normal array subscript 7014 // expression. 7015 DefaultFunctionArrayLvalueConversion(Res); 7016 7017 // C99 6.5.2.1p1 7018 Expr *Idx = static_cast<Expr*>(OC.U.E); 7019 // FIXME: Leaks Res 7020 if (!Idx->isTypeDependent() && !Idx->getType()->isIntegerType()) 7021 return ExprError(Diag(Idx->getLocStart(), 7022 diag::err_typecheck_subscript_not_integer) 7023 << Idx->getSourceRange()); 7024 7025 Res = new (Context) ArraySubscriptExpr(Res, Idx, AT->getElementType(), 7026 OC.LocEnd); 7027 continue; 7028 } 7029 7030 const RecordType *RC = Res->getType()->getAs<RecordType>(); 7031 if (!RC) { 7032 Res->Destroy(Context); 7033 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 7034 << Res->getType()); 7035 } 7036 7037 // Get the decl corresponding to this. 7038 RecordDecl *RD = RC->getDecl(); 7039 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 7040 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 7041 DiagRuntimeBehavior(BuiltinLoc, 7042 PDiag(diag::warn_offsetof_non_pod_type) 7043 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 7044 << Res->getType())) 7045 DidWarnAboutNonPOD = true; 7046 } 7047 7048 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 7049 LookupQualifiedName(R, RD); 7050 7051 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 7052 // FIXME: Leaks Res 7053 if (!MemberDecl) 7054 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 7055 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, OC.LocEnd)); 7056 7057 // C99 7.17p3: 7058 // (If the specified member is a bit-field, the behavior is undefined.) 7059 // 7060 // We diagnose this as an error. 7061 if (MemberDecl->getBitWidth()) { 7062 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 7063 << MemberDecl->getDeclName() 7064 << SourceRange(BuiltinLoc, RPLoc); 7065 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 7066 return ExprError(); 7067 } 7068 7069 // FIXME: C++: Verify that MemberDecl isn't a static field. 7070 // FIXME: Verify that MemberDecl isn't a bitfield. 7071 if (cast<RecordDecl>(MemberDecl->getDeclContext())->isAnonymousStructOrUnion()) { 7072 Res = BuildAnonymousStructUnionMemberReference( 7073 OC.LocEnd, MemberDecl, Res, OC.LocEnd).takeAs<Expr>(); 7074 } else { 7075 PerformObjectMemberConversion(Res, /*Qualifier=*/0, 7076 *R.begin(), MemberDecl); 7077 // MemberDecl->getType() doesn't get the right qualifiers, but it 7078 // doesn't matter here. 7079 Res = new (Context) MemberExpr(Res, false, MemberDecl, OC.LocEnd, 7080 MemberDecl->getType().getNonReferenceType()); 7081 } 7082 } 7083 } 7084 7085 return Owned(new (Context) UnaryOperator(Res, UnaryOperator::OffsetOf, 7086 Context.getSizeType(), BuiltinLoc)); 7087} 7088 7089 7090Sema::OwningExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 7091 TypeTy *arg1,TypeTy *arg2, 7092 SourceLocation RPLoc) { 7093 // FIXME: Preserve type source info. 7094 QualType argT1 = GetTypeFromParser(arg1); 7095 QualType argT2 = GetTypeFromParser(arg2); 7096 7097 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 7098 7099 if (getLangOptions().CPlusPlus) { 7100 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 7101 << SourceRange(BuiltinLoc, RPLoc); 7102 return ExprError(); 7103 } 7104 7105 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 7106 argT1, argT2, RPLoc)); 7107} 7108 7109Sema::OwningExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 7110 ExprArg cond, 7111 ExprArg expr1, ExprArg expr2, 7112 SourceLocation RPLoc) { 7113 Expr *CondExpr = static_cast<Expr*>(cond.get()); 7114 Expr *LHSExpr = static_cast<Expr*>(expr1.get()); 7115 Expr *RHSExpr = static_cast<Expr*>(expr2.get()); 7116 7117 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 7118 7119 QualType resType; 7120 bool ValueDependent = false; 7121 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 7122 resType = Context.DependentTy; 7123 ValueDependent = true; 7124 } else { 7125 // The conditional expression is required to be a constant expression. 7126 llvm::APSInt condEval(32); 7127 SourceLocation ExpLoc; 7128 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 7129 return ExprError(Diag(ExpLoc, 7130 diag::err_typecheck_choose_expr_requires_constant) 7131 << CondExpr->getSourceRange()); 7132 7133 // If the condition is > zero, then the AST type is the same as the LSHExpr. 7134 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 7135 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 7136 : RHSExpr->isValueDependent(); 7137 } 7138 7139 cond.release(); expr1.release(); expr2.release(); 7140 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 7141 resType, RPLoc, 7142 resType->isDependentType(), 7143 ValueDependent)); 7144} 7145 7146//===----------------------------------------------------------------------===// 7147// Clang Extensions. 7148//===----------------------------------------------------------------------===// 7149 7150/// ActOnBlockStart - This callback is invoked when a block literal is started. 7151void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 7152 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 7153 PushBlockScope(BlockScope, Block); 7154 CurContext->addDecl(Block); 7155 if (BlockScope) 7156 PushDeclContext(BlockScope, Block); 7157 else 7158 CurContext = Block; 7159} 7160 7161void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 7162 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 7163 BlockScopeInfo *CurBlock = getCurBlock(); 7164 7165 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 7166 CurBlock->TheDecl->setSignatureAsWritten(Sig); 7167 QualType T = Sig->getType(); 7168 7169 bool isVariadic; 7170 QualType RetTy; 7171 if (const FunctionType *Fn = T->getAs<FunctionType>()) { 7172 CurBlock->FunctionType = T; 7173 RetTy = Fn->getResultType(); 7174 isVariadic = 7175 !isa<FunctionProtoType>(Fn) || cast<FunctionProtoType>(Fn)->isVariadic(); 7176 } else { 7177 RetTy = T; 7178 isVariadic = false; 7179 } 7180 7181 CurBlock->TheDecl->setIsVariadic(isVariadic); 7182 7183 // Don't allow returning an array by value. 7184 if (RetTy->isArrayType()) { 7185 Diag(ParamInfo.getSourceRange().getBegin(), diag::err_block_returns_array); 7186 return; 7187 } 7188 7189 // Don't allow returning a objc interface by value. 7190 if (RetTy->isObjCObjectType()) { 7191 Diag(ParamInfo.getSourceRange().getBegin(), 7192 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7193 return; 7194 } 7195 7196 // Context.DependentTy is used as a placeholder for a missing block 7197 // return type. TODO: what should we do with declarators like: 7198 // ^ * { ... } 7199 // If the answer is "apply template argument deduction".... 7200 if (RetTy != Context.DependentTy) 7201 CurBlock->ReturnType = RetTy; 7202 7203 // Push block parameters from the declarator if we had them. 7204 llvm::SmallVector<ParmVarDecl*, 8> Params; 7205 if (isa<FunctionProtoType>(T)) { 7206 FunctionProtoTypeLoc TL = cast<FunctionProtoTypeLoc>(Sig->getTypeLoc()); 7207 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 7208 ParmVarDecl *Param = TL.getArg(I); 7209 if (Param->getIdentifier() == 0 && 7210 !Param->isImplicit() && 7211 !Param->isInvalidDecl() && 7212 !getLangOptions().CPlusPlus) 7213 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 7214 Params.push_back(Param); 7215 } 7216 7217 // Fake up parameter variables if we have a typedef, like 7218 // ^ fntype { ... } 7219 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 7220 for (FunctionProtoType::arg_type_iterator 7221 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 7222 ParmVarDecl *Param = 7223 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 7224 ParamInfo.getSourceRange().getBegin(), 7225 *I); 7226 Params.push_back(Param); 7227 } 7228 } 7229 7230 // Set the parameters on the block decl. 7231 if (!Params.empty()) 7232 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 7233 7234 // Finally we can process decl attributes. 7235 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 7236 7237 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 7238 Diag(ParamInfo.getAttributes()->getLoc(), 7239 diag::warn_attribute_sentinel_not_variadic) << 1; 7240 // FIXME: remove the attribute. 7241 } 7242 7243 // Put the parameter variables in scope. We can bail out immediately 7244 // if we don't have any. 7245 if (Params.empty()) 7246 return; 7247 7248 bool ShouldCheckShadow = 7249 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 7250 7251 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 7252 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 7253 (*AI)->setOwningFunction(CurBlock->TheDecl); 7254 7255 // If this has an identifier, add it to the scope stack. 7256 if ((*AI)->getIdentifier()) { 7257 if (ShouldCheckShadow) 7258 CheckShadow(CurBlock->TheScope, *AI); 7259 7260 PushOnScopeChains(*AI, CurBlock->TheScope); 7261 } 7262 } 7263} 7264 7265/// ActOnBlockError - If there is an error parsing a block, this callback 7266/// is invoked to pop the information about the block from the action impl. 7267void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7268 // Pop off CurBlock, handle nested blocks. 7269 PopDeclContext(); 7270 PopFunctionOrBlockScope(); 7271 // FIXME: Delete the ParmVarDecl objects as well??? 7272} 7273 7274/// ActOnBlockStmtExpr - This is called when the body of a block statement 7275/// literal was successfully completed. ^(int x){...} 7276Sema::OwningExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7277 StmtArg body, Scope *CurScope) { 7278 // If blocks are disabled, emit an error. 7279 if (!LangOpts.Blocks) 7280 Diag(CaretLoc, diag::err_blocks_disable); 7281 7282 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7283 7284 PopDeclContext(); 7285 7286 QualType RetTy = Context.VoidTy; 7287 if (!BSI->ReturnType.isNull()) 7288 RetTy = BSI->ReturnType; 7289 7290 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7291 QualType BlockTy; 7292 7293 // If the user wrote a function type in some form, try to use that. 7294 if (!BSI->FunctionType.isNull()) { 7295 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 7296 7297 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 7298 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 7299 7300 // Turn protoless block types into nullary block types. 7301 if (isa<FunctionNoProtoType>(FTy)) { 7302 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7303 false, false, 0, 0, Ext); 7304 7305 // Otherwise, if we don't need to change anything about the function type, 7306 // preserve its sugar structure. 7307 } else if (FTy->getResultType() == RetTy && 7308 (!NoReturn || FTy->getNoReturnAttr())) { 7309 BlockTy = BSI->FunctionType; 7310 7311 // Otherwise, make the minimal modifications to the function type. 7312 } else { 7313 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 7314 BlockTy = Context.getFunctionType(RetTy, 7315 FPT->arg_type_begin(), 7316 FPT->getNumArgs(), 7317 FPT->isVariadic(), 7318 /*quals*/ 0, 7319 FPT->hasExceptionSpec(), 7320 FPT->hasAnyExceptionSpec(), 7321 FPT->getNumExceptions(), 7322 FPT->exception_begin(), 7323 Ext); 7324 } 7325 7326 // If we don't have a function type, just build one from nothing. 7327 } else { 7328 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7329 false, false, 0, 0, 7330 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7331 } 7332 7333 // FIXME: Check that return/parameter types are complete/non-abstract 7334 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 7335 BSI->TheDecl->param_end()); 7336 BlockTy = Context.getBlockPointerType(BlockTy); 7337 7338 // If needed, diagnose invalid gotos and switches in the block. 7339 if (FunctionNeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7340 DiagnoseInvalidJumps(static_cast<CompoundStmt*>(body.get())); 7341 7342 BSI->TheDecl->setBody(body.takeAs<CompoundStmt>()); 7343 7344 bool Good = true; 7345 // Check goto/label use. 7346 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7347 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7348 LabelStmt *L = I->second; 7349 7350 // Verify that we have no forward references left. If so, there was a goto 7351 // or address of a label taken, but no definition of it. 7352 if (L->getSubStmt() != 0) 7353 continue; 7354 7355 // Emit error. 7356 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7357 Good = false; 7358 } 7359 if (!Good) { 7360 PopFunctionOrBlockScope(); 7361 return ExprError(); 7362 } 7363 7364 // Issue any analysis-based warnings. 7365 const sema::AnalysisBasedWarnings::Policy &WP = 7366 AnalysisWarnings.getDefaultPolicy(); 7367 AnalysisWarnings.IssueWarnings(WP, BSI->TheDecl, BlockTy); 7368 7369 Expr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7370 BSI->hasBlockDeclRefExprs); 7371 PopFunctionOrBlockScope(); 7372 return Owned(Result); 7373} 7374 7375Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7376 ExprArg expr, TypeTy *type, 7377 SourceLocation RPLoc) { 7378 QualType T = GetTypeFromParser(type); 7379 Expr *E = static_cast<Expr*>(expr.get()); 7380 Expr *OrigExpr = E; 7381 7382 InitBuiltinVaListType(); 7383 7384 // Get the va_list type 7385 QualType VaListType = Context.getBuiltinVaListType(); 7386 if (VaListType->isArrayType()) { 7387 // Deal with implicit array decay; for example, on x86-64, 7388 // va_list is an array, but it's supposed to decay to 7389 // a pointer for va_arg. 7390 VaListType = Context.getArrayDecayedType(VaListType); 7391 // Make sure the input expression also decays appropriately. 7392 UsualUnaryConversions(E); 7393 } else { 7394 // Otherwise, the va_list argument must be an l-value because 7395 // it is modified by va_arg. 7396 if (!E->isTypeDependent() && 7397 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7398 return ExprError(); 7399 } 7400 7401 if (!E->isTypeDependent() && 7402 !Context.hasSameType(VaListType, E->getType())) { 7403 return ExprError(Diag(E->getLocStart(), 7404 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7405 << OrigExpr->getType() << E->getSourceRange()); 7406 } 7407 7408 // FIXME: Check that type is complete/non-abstract 7409 // FIXME: Warn if a non-POD type is passed in. 7410 7411 expr.release(); 7412 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, 7413 T.getNonLValueExprType(Context), 7414 RPLoc)); 7415} 7416 7417Sema::OwningExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7418 // The type of __null will be int or long, depending on the size of 7419 // pointers on the target. 7420 QualType Ty; 7421 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7422 Ty = Context.IntTy; 7423 else 7424 Ty = Context.LongTy; 7425 7426 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7427} 7428 7429static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7430 Expr *SrcExpr, FixItHint &Hint) { 7431 if (!SemaRef.getLangOptions().ObjC1) 7432 return; 7433 7434 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7435 if (!PT) 7436 return; 7437 7438 // Check if the destination is of type 'id'. 7439 if (!PT->isObjCIdType()) { 7440 // Check if the destination is the 'NSString' interface. 7441 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7442 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7443 return; 7444 } 7445 7446 // Strip off any parens and casts. 7447 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7448 if (!SL || SL->isWide()) 7449 return; 7450 7451 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7452} 7453 7454bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7455 SourceLocation Loc, 7456 QualType DstType, QualType SrcType, 7457 Expr *SrcExpr, AssignmentAction Action, 7458 bool *Complained) { 7459 if (Complained) 7460 *Complained = false; 7461 7462 // Decode the result (notice that AST's are still created for extensions). 7463 bool isInvalid = false; 7464 unsigned DiagKind; 7465 FixItHint Hint; 7466 7467 switch (ConvTy) { 7468 default: assert(0 && "Unknown conversion type"); 7469 case Compatible: return false; 7470 case PointerToInt: 7471 DiagKind = diag::ext_typecheck_convert_pointer_int; 7472 break; 7473 case IntToPointer: 7474 DiagKind = diag::ext_typecheck_convert_int_pointer; 7475 break; 7476 case IncompatiblePointer: 7477 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7478 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7479 break; 7480 case IncompatiblePointerSign: 7481 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7482 break; 7483 case FunctionVoidPointer: 7484 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7485 break; 7486 case CompatiblePointerDiscardsQualifiers: 7487 // If the qualifiers lost were because we were applying the 7488 // (deprecated) C++ conversion from a string literal to a char* 7489 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7490 // Ideally, this check would be performed in 7491 // CheckPointerTypesForAssignment. However, that would require a 7492 // bit of refactoring (so that the second argument is an 7493 // expression, rather than a type), which should be done as part 7494 // of a larger effort to fix CheckPointerTypesForAssignment for 7495 // C++ semantics. 7496 if (getLangOptions().CPlusPlus && 7497 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7498 return false; 7499 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7500 break; 7501 case IncompatibleNestedPointerQualifiers: 7502 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7503 break; 7504 case IntToBlockPointer: 7505 DiagKind = diag::err_int_to_block_pointer; 7506 break; 7507 case IncompatibleBlockPointer: 7508 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7509 break; 7510 case IncompatibleObjCQualifiedId: 7511 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7512 // it can give a more specific diagnostic. 7513 DiagKind = diag::warn_incompatible_qualified_id; 7514 break; 7515 case IncompatibleVectors: 7516 DiagKind = diag::warn_incompatible_vectors; 7517 break; 7518 case Incompatible: 7519 DiagKind = diag::err_typecheck_convert_incompatible; 7520 isInvalid = true; 7521 break; 7522 } 7523 7524 QualType FirstType, SecondType; 7525 switch (Action) { 7526 case AA_Assigning: 7527 case AA_Initializing: 7528 // The destination type comes first. 7529 FirstType = DstType; 7530 SecondType = SrcType; 7531 break; 7532 7533 case AA_Returning: 7534 case AA_Passing: 7535 case AA_Converting: 7536 case AA_Sending: 7537 case AA_Casting: 7538 // The source type comes first. 7539 FirstType = SrcType; 7540 SecondType = DstType; 7541 break; 7542 } 7543 7544 Diag(Loc, DiagKind) << FirstType << SecondType << Action 7545 << SrcExpr->getSourceRange() << Hint; 7546 if (Complained) 7547 *Complained = true; 7548 return isInvalid; 7549} 7550 7551bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7552 llvm::APSInt ICEResult; 7553 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7554 if (Result) 7555 *Result = ICEResult; 7556 return false; 7557 } 7558 7559 Expr::EvalResult EvalResult; 7560 7561 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7562 EvalResult.HasSideEffects) { 7563 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7564 7565 if (EvalResult.Diag) { 7566 // We only show the note if it's not the usual "invalid subexpression" 7567 // or if it's actually in a subexpression. 7568 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7569 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7570 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7571 } 7572 7573 return true; 7574 } 7575 7576 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7577 E->getSourceRange(); 7578 7579 if (EvalResult.Diag && 7580 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7581 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7582 7583 if (Result) 7584 *Result = EvalResult.Val.getInt(); 7585 return false; 7586} 7587 7588void 7589Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7590 ExprEvalContexts.push_back( 7591 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7592} 7593 7594void 7595Sema::PopExpressionEvaluationContext() { 7596 // Pop the current expression evaluation context off the stack. 7597 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7598 ExprEvalContexts.pop_back(); 7599 7600 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7601 if (Rec.PotentiallyReferenced) { 7602 // Mark any remaining declarations in the current position of the stack 7603 // as "referenced". If they were not meant to be referenced, semantic 7604 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7605 for (PotentiallyReferencedDecls::iterator 7606 I = Rec.PotentiallyReferenced->begin(), 7607 IEnd = Rec.PotentiallyReferenced->end(); 7608 I != IEnd; ++I) 7609 MarkDeclarationReferenced(I->first, I->second); 7610 } 7611 7612 if (Rec.PotentiallyDiagnosed) { 7613 // Emit any pending diagnostics. 7614 for (PotentiallyEmittedDiagnostics::iterator 7615 I = Rec.PotentiallyDiagnosed->begin(), 7616 IEnd = Rec.PotentiallyDiagnosed->end(); 7617 I != IEnd; ++I) 7618 Diag(I->first, I->second); 7619 } 7620 } 7621 7622 // When are coming out of an unevaluated context, clear out any 7623 // temporaries that we may have created as part of the evaluation of 7624 // the expression in that context: they aren't relevant because they 7625 // will never be constructed. 7626 if (Rec.Context == Unevaluated && 7627 ExprTemporaries.size() > Rec.NumTemporaries) 7628 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7629 ExprTemporaries.end()); 7630 7631 // Destroy the popped expression evaluation record. 7632 Rec.Destroy(); 7633} 7634 7635/// \brief Note that the given declaration was referenced in the source code. 7636/// 7637/// This routine should be invoke whenever a given declaration is referenced 7638/// in the source code, and where that reference occurred. If this declaration 7639/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7640/// C99 6.9p3), then the declaration will be marked as used. 7641/// 7642/// \param Loc the location where the declaration was referenced. 7643/// 7644/// \param D the declaration that has been referenced by the source code. 7645void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7646 assert(D && "No declaration?"); 7647 7648 if (D->isUsed(false)) 7649 return; 7650 7651 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7652 // template or not. The reason for this is that unevaluated expressions 7653 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7654 // -Wunused-parameters) 7655 if (isa<ParmVarDecl>(D) || 7656 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7657 D->setUsed(true); 7658 return; 7659 } 7660 7661 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7662 return; 7663 7664 // Do not mark anything as "used" within a dependent context; wait for 7665 // an instantiation. 7666 if (CurContext->isDependentContext()) 7667 return; 7668 7669 switch (ExprEvalContexts.back().Context) { 7670 case Unevaluated: 7671 // We are in an expression that is not potentially evaluated; do nothing. 7672 return; 7673 7674 case PotentiallyEvaluated: 7675 // We are in a potentially-evaluated expression, so this declaration is 7676 // "used"; handle this below. 7677 break; 7678 7679 case PotentiallyPotentiallyEvaluated: 7680 // We are in an expression that may be potentially evaluated; queue this 7681 // declaration reference until we know whether the expression is 7682 // potentially evaluated. 7683 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7684 return; 7685 } 7686 7687 // Note that this declaration has been used. 7688 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7689 unsigned TypeQuals; 7690 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7691 if (!Constructor->isUsed(false)) 7692 DefineImplicitDefaultConstructor(Loc, Constructor); 7693 } else if (Constructor->isImplicit() && 7694 Constructor->isCopyConstructor(TypeQuals)) { 7695 if (!Constructor->isUsed(false)) 7696 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7697 } 7698 7699 MarkVTableUsed(Loc, Constructor->getParent()); 7700 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7701 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 7702 DefineImplicitDestructor(Loc, Destructor); 7703 if (Destructor->isVirtual()) 7704 MarkVTableUsed(Loc, Destructor->getParent()); 7705 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7706 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7707 MethodDecl->getOverloadedOperator() == OO_Equal) { 7708 if (!MethodDecl->isUsed(false)) 7709 DefineImplicitCopyAssignment(Loc, MethodDecl); 7710 } else if (MethodDecl->isVirtual()) 7711 MarkVTableUsed(Loc, MethodDecl->getParent()); 7712 } 7713 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7714 // Implicit instantiation of function templates and member functions of 7715 // class templates. 7716 if (Function->isImplicitlyInstantiable()) { 7717 bool AlreadyInstantiated = false; 7718 if (FunctionTemplateSpecializationInfo *SpecInfo 7719 = Function->getTemplateSpecializationInfo()) { 7720 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7721 SpecInfo->setPointOfInstantiation(Loc); 7722 else if (SpecInfo->getTemplateSpecializationKind() 7723 == TSK_ImplicitInstantiation) 7724 AlreadyInstantiated = true; 7725 } else if (MemberSpecializationInfo *MSInfo 7726 = Function->getMemberSpecializationInfo()) { 7727 if (MSInfo->getPointOfInstantiation().isInvalid()) 7728 MSInfo->setPointOfInstantiation(Loc); 7729 else if (MSInfo->getTemplateSpecializationKind() 7730 == TSK_ImplicitInstantiation) 7731 AlreadyInstantiated = true; 7732 } 7733 7734 if (!AlreadyInstantiated) { 7735 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7736 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7737 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7738 Loc)); 7739 else 7740 PendingImplicitInstantiations.push_back(std::make_pair(Function, 7741 Loc)); 7742 } 7743 } 7744 7745 // FIXME: keep track of references to static functions 7746 Function->setUsed(true); 7747 7748 return; 7749 } 7750 7751 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7752 // Implicit instantiation of static data members of class templates. 7753 if (Var->isStaticDataMember() && 7754 Var->getInstantiatedFromStaticDataMember()) { 7755 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7756 assert(MSInfo && "Missing member specialization information?"); 7757 if (MSInfo->getPointOfInstantiation().isInvalid() && 7758 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7759 MSInfo->setPointOfInstantiation(Loc); 7760 PendingImplicitInstantiations.push_back(std::make_pair(Var, Loc)); 7761 } 7762 } 7763 7764 // FIXME: keep track of references to static data? 7765 7766 D->setUsed(true); 7767 return; 7768 } 7769} 7770 7771namespace { 7772 // Mark all of the declarations referenced 7773 // FIXME: Not fully implemented yet! We need to have a better understanding 7774 // of when we're entering 7775 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 7776 Sema &S; 7777 SourceLocation Loc; 7778 7779 public: 7780 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 7781 7782 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 7783 7784 bool TraverseTemplateArgument(const TemplateArgument &Arg); 7785 bool TraverseRecordType(RecordType *T); 7786 }; 7787} 7788 7789bool MarkReferencedDecls::TraverseTemplateArgument( 7790 const TemplateArgument &Arg) { 7791 if (Arg.getKind() == TemplateArgument::Declaration) { 7792 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 7793 } 7794 7795 return Inherited::TraverseTemplateArgument(Arg); 7796} 7797 7798bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 7799 if (ClassTemplateSpecializationDecl *Spec 7800 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 7801 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 7802 return TraverseTemplateArguments(Args.getFlatArgumentList(), 7803 Args.flat_size()); 7804 } 7805 7806 return true; 7807} 7808 7809void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 7810 MarkReferencedDecls Marker(*this, Loc); 7811 Marker.TraverseType(Context.getCanonicalType(T)); 7812} 7813 7814/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7815/// of the program being compiled. 7816/// 7817/// This routine emits the given diagnostic when the code currently being 7818/// type-checked is "potentially evaluated", meaning that there is a 7819/// possibility that the code will actually be executable. Code in sizeof() 7820/// expressions, code used only during overload resolution, etc., are not 7821/// potentially evaluated. This routine will suppress such diagnostics or, 7822/// in the absolutely nutty case of potentially potentially evaluated 7823/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7824/// later. 7825/// 7826/// This routine should be used for all diagnostics that describe the run-time 7827/// behavior of a program, such as passing a non-POD value through an ellipsis. 7828/// Failure to do so will likely result in spurious diagnostics or failures 7829/// during overload resolution or within sizeof/alignof/typeof/typeid. 7830bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7831 const PartialDiagnostic &PD) { 7832 switch (ExprEvalContexts.back().Context ) { 7833 case Unevaluated: 7834 // The argument will never be evaluated, so don't complain. 7835 break; 7836 7837 case PotentiallyEvaluated: 7838 Diag(Loc, PD); 7839 return true; 7840 7841 case PotentiallyPotentiallyEvaluated: 7842 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7843 break; 7844 } 7845 7846 return false; 7847} 7848 7849bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7850 CallExpr *CE, FunctionDecl *FD) { 7851 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7852 return false; 7853 7854 PartialDiagnostic Note = 7855 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7856 << FD->getDeclName() : PDiag(); 7857 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7858 7859 if (RequireCompleteType(Loc, ReturnType, 7860 FD ? 7861 PDiag(diag::err_call_function_incomplete_return) 7862 << CE->getSourceRange() << FD->getDeclName() : 7863 PDiag(diag::err_call_incomplete_return) 7864 << CE->getSourceRange(), 7865 std::make_pair(NoteLoc, Note))) 7866 return true; 7867 7868 return false; 7869} 7870 7871// Diagnose the common s/=/==/ typo. Note that adding parentheses 7872// will prevent this condition from triggering, which is what we want. 7873void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7874 SourceLocation Loc; 7875 7876 unsigned diagnostic = diag::warn_condition_is_assignment; 7877 7878 if (isa<BinaryOperator>(E)) { 7879 BinaryOperator *Op = cast<BinaryOperator>(E); 7880 if (Op->getOpcode() != BinaryOperator::Assign) 7881 return; 7882 7883 // Greylist some idioms by putting them into a warning subcategory. 7884 if (ObjCMessageExpr *ME 7885 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7886 Selector Sel = ME->getSelector(); 7887 7888 // self = [<foo> init...] 7889 if (isSelfExpr(Op->getLHS()) 7890 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7891 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7892 7893 // <foo> = [<bar> nextObject] 7894 else if (Sel.isUnarySelector() && 7895 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7896 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7897 } 7898 7899 Loc = Op->getOperatorLoc(); 7900 } else if (isa<CXXOperatorCallExpr>(E)) { 7901 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7902 if (Op->getOperator() != OO_Equal) 7903 return; 7904 7905 Loc = Op->getOperatorLoc(); 7906 } else { 7907 // Not an assignment. 7908 return; 7909 } 7910 7911 SourceLocation Open = E->getSourceRange().getBegin(); 7912 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7913 7914 Diag(Loc, diagnostic) << E->getSourceRange(); 7915 Diag(Loc, diag::note_condition_assign_to_comparison) 7916 << FixItHint::CreateReplacement(Loc, "=="); 7917 Diag(Loc, diag::note_condition_assign_silence) 7918 << FixItHint::CreateInsertion(Open, "(") 7919 << FixItHint::CreateInsertion(Close, ")"); 7920} 7921 7922bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7923 DiagnoseAssignmentAsCondition(E); 7924 7925 if (!E->isTypeDependent()) { 7926 DefaultFunctionArrayLvalueConversion(E); 7927 7928 QualType T = E->getType(); 7929 7930 if (getLangOptions().CPlusPlus) { 7931 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7932 return true; 7933 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7934 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7935 << T << E->getSourceRange(); 7936 return true; 7937 } 7938 } 7939 7940 return false; 7941} 7942 7943Sema::OwningExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 7944 ExprArg SubExpr) { 7945 Expr *Sub = SubExpr.takeAs<Expr>(); 7946 if (!Sub) 7947 return ExprError(); 7948 7949 if (CheckBooleanCondition(Sub, Loc)) { 7950 Sub->Destroy(Context); 7951 return ExprError(); 7952 } 7953 7954 return Owned(Sub); 7955} 7956