SemaExpr.cpp revision 039bfd7e038eb852c66be03bb34c47fa2a7b79a7
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::err_unavailable) << D->getDeclName(); 63 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 64 } 65 66 // See if this is a deleted function. 67 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 68 if (FD->isDeleted()) { 69 Diag(Loc, diag::err_deleted_function_use); 70 Diag(D->getLocation(), diag::note_unavailable_here) << true; 71 return true; 72 } 73 } 74 75 return false; 76} 77 78/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 79/// (and other functions in future), which have been declared with sentinel 80/// attribute. It warns if call does not have the sentinel argument. 81/// 82void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 83 Expr **Args, unsigned NumArgs) { 84 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 85 if (!attr) 86 return; 87 88 // FIXME: In C++0x, if any of the arguments are parameter pack 89 // expansions, we can't check for the sentinel now. 90 int sentinelPos = attr->getSentinel(); 91 int nullPos = attr->getNullPos(); 92 93 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 94 // base class. Then we won't be needing two versions of the same code. 95 unsigned int i = 0; 96 bool warnNotEnoughArgs = false; 97 int isMethod = 0; 98 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 99 // skip over named parameters. 100 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 101 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 102 if (nullPos) 103 --nullPos; 104 else 105 ++i; 106 } 107 warnNotEnoughArgs = (P != E || i >= NumArgs); 108 isMethod = 1; 109 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 110 // skip over named parameters. 111 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 112 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 113 if (nullPos) 114 --nullPos; 115 else 116 ++i; 117 } 118 warnNotEnoughArgs = (P != E || i >= NumArgs); 119 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 120 // block or function pointer call. 121 QualType Ty = V->getType(); 122 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 123 const FunctionType *FT = Ty->isFunctionPointerType() 124 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 125 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 126 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 127 unsigned NumArgsInProto = Proto->getNumArgs(); 128 unsigned k; 129 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 130 if (nullPos) 131 --nullPos; 132 else 133 ++i; 134 } 135 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 136 } 137 if (Ty->isBlockPointerType()) 138 isMethod = 2; 139 } else 140 return; 141 } else 142 return; 143 144 if (warnNotEnoughArgs) { 145 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 146 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 147 return; 148 } 149 int sentinel = i; 150 while (sentinelPos > 0 && i < NumArgs-1) { 151 --sentinelPos; 152 ++i; 153 } 154 if (sentinelPos > 0) { 155 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 156 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 157 return; 158 } 159 while (i < NumArgs-1) { 160 ++i; 161 ++sentinel; 162 } 163 Expr *sentinelExpr = Args[sentinel]; 164 if (!sentinelExpr) return; 165 if (sentinelExpr->isTypeDependent()) return; 166 if (sentinelExpr->isValueDependent()) return; 167 if (sentinelExpr->getType()->isAnyPointerType() && 168 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 169 Expr::NPC_ValueDependentIsNull)) 170 return; 171 172 // Unfortunately, __null has type 'int'. 173 if (isa<GNUNullExpr>(sentinelExpr)) return; 174 175 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 176 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 177} 178 179SourceRange Sema::getExprRange(ExprTy *E) const { 180 Expr *Ex = (Expr *)E; 181 return Ex? Ex->getSourceRange() : SourceRange(); 182} 183 184//===----------------------------------------------------------------------===// 185// Standard Promotions and Conversions 186//===----------------------------------------------------------------------===// 187 188/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 189void Sema::DefaultFunctionArrayConversion(Expr *&E) { 190 QualType Ty = E->getType(); 191 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 192 193 if (Ty->isFunctionType()) 194 ImpCastExprToType(E, Context.getPointerType(Ty), 195 CastExpr::CK_FunctionToPointerDecay); 196 else if (Ty->isArrayType()) { 197 // In C90 mode, arrays only promote to pointers if the array expression is 198 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 199 // type 'array of type' is converted to an expression that has type 'pointer 200 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 201 // that has type 'array of type' ...". The relevant change is "an lvalue" 202 // (C90) to "an expression" (C99). 203 // 204 // C++ 4.2p1: 205 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 206 // T" can be converted to an rvalue of type "pointer to T". 207 // 208 if (getLangOptions().C99 || getLangOptions().CPlusPlus || 209 E->isLvalue(Context) == Expr::LV_Valid) 210 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 211 CastExpr::CK_ArrayToPointerDecay); 212 } 213} 214 215void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 216 DefaultFunctionArrayConversion(E); 217 218 QualType Ty = E->getType(); 219 assert(!Ty.isNull() && "DefaultFunctionArrayLvalueConversion - missing type"); 220 if (!Ty->isDependentType() && Ty.hasQualifiers() && 221 (!getLangOptions().CPlusPlus || !Ty->isRecordType()) && 222 E->isLvalue(Context) == Expr::LV_Valid) { 223 // C++ [conv.lval]p1: 224 // [...] If T is a non-class type, the type of the rvalue is the 225 // cv-unqualified version of T. Otherwise, the type of the 226 // rvalue is T 227 // 228 // C99 6.3.2.1p2: 229 // If the lvalue has qualified type, the value has the unqualified 230 // version of the type of the lvalue; otherwise, the value has the 231 // type of the lvalue. 232 ImpCastExprToType(E, Ty.getUnqualifiedType(), CastExpr::CK_NoOp); 233 } 234} 235 236 237/// UsualUnaryConversions - Performs various conversions that are common to most 238/// operators (C99 6.3). The conversions of array and function types are 239/// sometimes surpressed. For example, the array->pointer conversion doesn't 240/// apply if the array is an argument to the sizeof or address (&) operators. 241/// In these instances, this routine should *not* be called. 242Expr *Sema::UsualUnaryConversions(Expr *&Expr) { 243 QualType Ty = Expr->getType(); 244 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 245 246 // C99 6.3.1.1p2: 247 // 248 // The following may be used in an expression wherever an int or 249 // unsigned int may be used: 250 // - an object or expression with an integer type whose integer 251 // conversion rank is less than or equal to the rank of int 252 // and unsigned int. 253 // - A bit-field of type _Bool, int, signed int, or unsigned int. 254 // 255 // If an int can represent all values of the original type, the 256 // value is converted to an int; otherwise, it is converted to an 257 // unsigned int. These are called the integer promotions. All 258 // other types are unchanged by the integer promotions. 259 QualType PTy = Context.isPromotableBitField(Expr); 260 if (!PTy.isNull()) { 261 ImpCastExprToType(Expr, PTy, CastExpr::CK_IntegralCast); 262 return Expr; 263 } 264 if (Ty->isPromotableIntegerType()) { 265 QualType PT = Context.getPromotedIntegerType(Ty); 266 ImpCastExprToType(Expr, PT, CastExpr::CK_IntegralCast); 267 return Expr; 268 } 269 270 DefaultFunctionArrayLvalueConversion(Expr); 271 return Expr; 272} 273 274/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 275/// do not have a prototype. Arguments that have type float are promoted to 276/// double. All other argument types are converted by UsualUnaryConversions(). 277void Sema::DefaultArgumentPromotion(Expr *&Expr) { 278 QualType Ty = Expr->getType(); 279 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 280 281 // If this is a 'float' (CVR qualified or typedef) promote to double. 282 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 283 return ImpCastExprToType(Expr, Context.DoubleTy, 284 CastExpr::CK_FloatingCast); 285 286 UsualUnaryConversions(Expr); 287} 288 289/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 290/// will warn if the resulting type is not a POD type, and rejects ObjC 291/// interfaces passed by value. This returns true if the argument type is 292/// completely illegal. 293bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 294 FunctionDecl *FDecl) { 295 DefaultArgumentPromotion(Expr); 296 297 // __builtin_va_start takes the second argument as a "varargs" argument, but 298 // it doesn't actually do anything with it. It doesn't need to be non-pod 299 // etc. 300 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 301 return false; 302 303 if (Expr->getType()->isObjCObjectType() && 304 DiagRuntimeBehavior(Expr->getLocStart(), 305 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 306 << Expr->getType() << CT)) 307 return true; 308 309 if (!Expr->getType()->isPODType() && 310 DiagRuntimeBehavior(Expr->getLocStart(), 311 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 312 << Expr->getType() << CT)) 313 return true; 314 315 return false; 316} 317 318 319/// UsualArithmeticConversions - Performs various conversions that are common to 320/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 321/// routine returns the first non-arithmetic type found. The client is 322/// responsible for emitting appropriate error diagnostics. 323/// FIXME: verify the conversion rules for "complex int" are consistent with 324/// GCC. 325QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 326 bool isCompAssign) { 327 if (!isCompAssign) 328 UsualUnaryConversions(lhsExpr); 329 330 UsualUnaryConversions(rhsExpr); 331 332 // For conversion purposes, we ignore any qualifiers. 333 // For example, "const float" and "float" are equivalent. 334 QualType lhs = 335 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 336 QualType rhs = 337 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 338 339 // If both types are identical, no conversion is needed. 340 if (lhs == rhs) 341 return lhs; 342 343 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 344 // The caller can deal with this (e.g. pointer + int). 345 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 346 return lhs; 347 348 // Perform bitfield promotions. 349 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 350 if (!LHSBitfieldPromoteTy.isNull()) 351 lhs = LHSBitfieldPromoteTy; 352 QualType RHSBitfieldPromoteTy = Context.isPromotableBitField(rhsExpr); 353 if (!RHSBitfieldPromoteTy.isNull()) 354 rhs = RHSBitfieldPromoteTy; 355 356 QualType destType = Context.UsualArithmeticConversionsType(lhs, rhs); 357 if (!isCompAssign) 358 ImpCastExprToType(lhsExpr, destType, CastExpr::CK_Unknown); 359 ImpCastExprToType(rhsExpr, destType, CastExpr::CK_Unknown); 360 return destType; 361} 362 363//===----------------------------------------------------------------------===// 364// Semantic Analysis for various Expression Types 365//===----------------------------------------------------------------------===// 366 367 368/// ActOnStringLiteral - The specified tokens were lexed as pasted string 369/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 370/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 371/// multiple tokens. However, the common case is that StringToks points to one 372/// string. 373/// 374Action::OwningExprResult 375Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 376 assert(NumStringToks && "Must have at least one string!"); 377 378 StringLiteralParser Literal(StringToks, NumStringToks, PP); 379 if (Literal.hadError) 380 return ExprError(); 381 382 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 383 for (unsigned i = 0; i != NumStringToks; ++i) 384 StringTokLocs.push_back(StringToks[i].getLocation()); 385 386 QualType StrTy = Context.CharTy; 387 if (Literal.AnyWide) StrTy = Context.getWCharType(); 388 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 389 390 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 391 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 392 StrTy.addConst(); 393 394 // Get an array type for the string, according to C99 6.4.5. This includes 395 // the nul terminator character as well as the string length for pascal 396 // strings. 397 StrTy = Context.getConstantArrayType(StrTy, 398 llvm::APInt(32, Literal.GetNumStringChars()+1), 399 ArrayType::Normal, 0); 400 401 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 402 return Owned(StringLiteral::Create(Context, Literal.GetString(), 403 Literal.GetStringLength(), 404 Literal.AnyWide, StrTy, 405 &StringTokLocs[0], 406 StringTokLocs.size())); 407} 408 409/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 410/// CurBlock to VD should cause it to be snapshotted (as we do for auto 411/// variables defined outside the block) or false if this is not needed (e.g. 412/// for values inside the block or for globals). 413/// 414/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 415/// up-to-date. 416/// 417static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 418 ValueDecl *VD) { 419 // If the value is defined inside the block, we couldn't snapshot it even if 420 // we wanted to. 421 if (CurBlock->TheDecl == VD->getDeclContext()) 422 return false; 423 424 // If this is an enum constant or function, it is constant, don't snapshot. 425 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 426 return false; 427 428 // If this is a reference to an extern, static, or global variable, no need to 429 // snapshot it. 430 // FIXME: What about 'const' variables in C++? 431 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 432 if (!Var->hasLocalStorage()) 433 return false; 434 435 // Blocks that have these can't be constant. 436 CurBlock->hasBlockDeclRefExprs = true; 437 438 // If we have nested blocks, the decl may be declared in an outer block (in 439 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 440 // be defined outside all of the current blocks (in which case the blocks do 441 // all get the bit). Walk the nesting chain. 442 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 443 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 444 445 if (!NextBlock) 446 continue; 447 448 // If we found the defining block for the variable, don't mark the block as 449 // having a reference outside it. 450 if (NextBlock->TheDecl == VD->getDeclContext()) 451 break; 452 453 // Otherwise, the DeclRef from the inner block causes the outer one to need 454 // a snapshot as well. 455 NextBlock->hasBlockDeclRefExprs = true; 456 } 457 458 return true; 459} 460 461 462 463/// 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 MarkDeclarationReferenced(Loc, BaseObject); 557 BaseObjectExpr = new (Context) DeclRefExpr(BaseObject,BaseObject->getType(), 558 SourceLocation()); 559 BaseQuals 560 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 561 } else if (BaseObjectExpr) { 562 // The caller provided the base object expression. Determine 563 // whether its a pointer and whether it adds any qualifiers to the 564 // anonymous struct/union fields we're looking into. 565 QualType ObjectType = BaseObjectExpr->getType(); 566 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 567 BaseObjectIsPointer = true; 568 ObjectType = ObjectPtr->getPointeeType(); 569 } 570 BaseQuals 571 = Context.getCanonicalType(ObjectType).getQualifiers(); 572 } else { 573 // We've found a member of an anonymous struct/union that is 574 // inside a non-anonymous struct/union, so in a well-formed 575 // program our base object expression is "this". 576 DeclContext *DC = getFunctionLevelDeclContext(); 577 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 578 if (!MD->isStatic()) { 579 QualType AnonFieldType 580 = Context.getTagDeclType( 581 cast<RecordDecl>(AnonFields.back()->getDeclContext())); 582 QualType ThisType = Context.getTagDeclType(MD->getParent()); 583 if ((Context.getCanonicalType(AnonFieldType) 584 == Context.getCanonicalType(ThisType)) || 585 IsDerivedFrom(ThisType, AnonFieldType)) { 586 // Our base object expression is "this". 587 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 588 MD->getThisType(Context), 589 /*isImplicit=*/true); 590 BaseObjectIsPointer = true; 591 } 592 } else { 593 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 594 << Field->getDeclName()); 595 } 596 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 597 } 598 599 if (!BaseObjectExpr) 600 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 601 << Field->getDeclName()); 602 } 603 604 // Build the implicit member references to the field of the 605 // anonymous struct/union. 606 Expr *Result = BaseObjectExpr; 607 Qualifiers ResultQuals = BaseQuals; 608 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 609 FI = AnonFields.rbegin(), FIEnd = AnonFields.rend(); 610 FI != FIEnd; ++FI) { 611 QualType MemberType = (*FI)->getType(); 612 Qualifiers MemberTypeQuals = 613 Context.getCanonicalType(MemberType).getQualifiers(); 614 615 // CVR attributes from the base are picked up by members, 616 // except that 'mutable' members don't pick up 'const'. 617 if ((*FI)->isMutable()) 618 ResultQuals.removeConst(); 619 620 // GC attributes are never picked up by members. 621 ResultQuals.removeObjCGCAttr(); 622 623 // TR 18037 does not allow fields to be declared with address spaces. 624 assert(!MemberTypeQuals.hasAddressSpace()); 625 626 Qualifiers NewQuals = ResultQuals + MemberTypeQuals; 627 if (NewQuals != MemberTypeQuals) 628 MemberType = Context.getQualifiedType(MemberType, NewQuals); 629 630 MarkDeclarationReferenced(Loc, *FI); 631 PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI, *FI); 632 // FIXME: Might this end up being a qualified name? 633 Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI, 634 OpLoc, MemberType); 635 BaseObjectIsPointer = false; 636 ResultQuals = NewQuals; 637 } 638 639 return Owned(Result); 640} 641 642/// Decomposes the given name into a DeclarationName, its location, and 643/// possibly a list of template arguments. 644/// 645/// If this produces template arguments, it is permitted to call 646/// DecomposeTemplateName. 647/// 648/// This actually loses a lot of source location information for 649/// non-standard name kinds; we should consider preserving that in 650/// some way. 651static void DecomposeUnqualifiedId(Sema &SemaRef, 652 const UnqualifiedId &Id, 653 TemplateArgumentListInfo &Buffer, 654 DeclarationName &Name, 655 SourceLocation &NameLoc, 656 const TemplateArgumentListInfo *&TemplateArgs) { 657 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 658 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 659 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 660 661 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 662 Id.TemplateId->getTemplateArgs(), 663 Id.TemplateId->NumArgs); 664 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 665 TemplateArgsPtr.release(); 666 667 TemplateName TName = 668 Sema::TemplateTy::make(Id.TemplateId->Template).getAsVal<TemplateName>(); 669 670 Name = SemaRef.Context.getNameForTemplate(TName); 671 NameLoc = Id.TemplateId->TemplateNameLoc; 672 TemplateArgs = &Buffer; 673 } else { 674 Name = SemaRef.GetNameFromUnqualifiedId(Id); 675 NameLoc = Id.StartLocation; 676 TemplateArgs = 0; 677 } 678} 679 680/// Determines whether the given record is "fully-formed" at the given 681/// location, i.e. whether a qualified lookup into it is assured of 682/// getting consistent results already. 683static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 684 if (!Record->hasDefinition()) 685 return false; 686 687 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 688 E = Record->bases_end(); I != E; ++I) { 689 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 690 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 691 if (!BaseRT) return false; 692 693 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 694 if (!BaseRecord->hasDefinition() || 695 !IsFullyFormedScope(SemaRef, BaseRecord)) 696 return false; 697 } 698 699 return true; 700} 701 702/// Determines if the given class is provably not derived from all of 703/// the prospective base classes. 704static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 705 CXXRecordDecl *Record, 706 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 707 if (Bases.count(Record->getCanonicalDecl())) 708 return false; 709 710 RecordDecl *RD = Record->getDefinition(); 711 if (!RD) return false; 712 Record = cast<CXXRecordDecl>(RD); 713 714 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 715 E = Record->bases_end(); I != E; ++I) { 716 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 717 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 718 if (!BaseRT) return false; 719 720 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 721 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 722 return false; 723 } 724 725 return true; 726} 727 728enum IMAKind { 729 /// The reference is definitely not an instance member access. 730 IMA_Static, 731 732 /// The reference may be an implicit instance member access. 733 IMA_Mixed, 734 735 /// The reference may be to an instance member, but it is invalid if 736 /// so, because the context is not an instance method. 737 IMA_Mixed_StaticContext, 738 739 /// The reference may be to an instance member, but it is invalid if 740 /// so, because the context is from an unrelated class. 741 IMA_Mixed_Unrelated, 742 743 /// The reference is definitely an implicit instance member access. 744 IMA_Instance, 745 746 /// The reference may be to an unresolved using declaration. 747 IMA_Unresolved, 748 749 /// The reference may be to an unresolved using declaration and the 750 /// context is not an instance method. 751 IMA_Unresolved_StaticContext, 752 753 /// The reference is to a member of an anonymous structure in a 754 /// non-class context. 755 IMA_AnonymousMember, 756 757 /// All possible referrents are instance members and the current 758 /// context is not an instance method. 759 IMA_Error_StaticContext, 760 761 /// All possible referrents are instance members of an unrelated 762 /// class. 763 IMA_Error_Unrelated 764}; 765 766/// The given lookup names class member(s) and is not being used for 767/// an address-of-member expression. Classify the type of access 768/// according to whether it's possible that this reference names an 769/// instance member. This is best-effort; it is okay to 770/// conservatively answer "yes", in which case some errors will simply 771/// not be caught until template-instantiation. 772static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 773 const LookupResult &R) { 774 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 775 776 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 777 bool isStaticContext = 778 (!isa<CXXMethodDecl>(DC) || 779 cast<CXXMethodDecl>(DC)->isStatic()); 780 781 if (R.isUnresolvableResult()) 782 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 783 784 // Collect all the declaring classes of instance members we find. 785 bool hasNonInstance = false; 786 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 787 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 788 NamedDecl *D = *I; 789 if (D->isCXXInstanceMember()) { 790 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 791 792 // If this is a member of an anonymous record, move out to the 793 // innermost non-anonymous struct or union. If there isn't one, 794 // that's a special case. 795 while (R->isAnonymousStructOrUnion()) { 796 R = dyn_cast<CXXRecordDecl>(R->getParent()); 797 if (!R) return IMA_AnonymousMember; 798 } 799 Classes.insert(R->getCanonicalDecl()); 800 } 801 else 802 hasNonInstance = true; 803 } 804 805 // If we didn't find any instance members, it can't be an implicit 806 // member reference. 807 if (Classes.empty()) 808 return IMA_Static; 809 810 // If the current context is not an instance method, it can't be 811 // an implicit member reference. 812 if (isStaticContext) 813 return (hasNonInstance ? IMA_Mixed_StaticContext : IMA_Error_StaticContext); 814 815 // If we can prove that the current context is unrelated to all the 816 // declaring classes, it can't be an implicit member reference (in 817 // which case it's an error if any of those members are selected). 818 if (IsProvablyNotDerivedFrom(SemaRef, 819 cast<CXXMethodDecl>(DC)->getParent(), 820 Classes)) 821 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 822 823 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 824} 825 826/// Diagnose a reference to a field with no object available. 827static void DiagnoseInstanceReference(Sema &SemaRef, 828 const CXXScopeSpec &SS, 829 const LookupResult &R) { 830 SourceLocation Loc = R.getNameLoc(); 831 SourceRange Range(Loc); 832 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 833 834 if (R.getAsSingle<FieldDecl>()) { 835 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 836 if (MD->isStatic()) { 837 // "invalid use of member 'x' in static member function" 838 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 839 << Range << R.getLookupName(); 840 return; 841 } 842 } 843 844 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 845 << R.getLookupName() << Range; 846 return; 847 } 848 849 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 850} 851 852/// Diagnose an empty lookup. 853/// 854/// \return false if new lookup candidates were found 855bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 856 CorrectTypoContext CTC) { 857 DeclarationName Name = R.getLookupName(); 858 859 unsigned diagnostic = diag::err_undeclared_var_use; 860 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 861 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 862 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 863 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 864 diagnostic = diag::err_undeclared_use; 865 diagnostic_suggest = diag::err_undeclared_use_suggest; 866 } 867 868 // If the original lookup was an unqualified lookup, fake an 869 // unqualified lookup. This is useful when (for example) the 870 // original lookup would not have found something because it was a 871 // dependent name. 872 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 873 DC; DC = DC->getParent()) { 874 if (isa<CXXRecordDecl>(DC)) { 875 LookupQualifiedName(R, DC); 876 877 if (!R.empty()) { 878 // Don't give errors about ambiguities in this lookup. 879 R.suppressDiagnostics(); 880 881 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 882 bool isInstance = CurMethod && 883 CurMethod->isInstance() && 884 DC == CurMethod->getParent(); 885 886 // Give a code modification hint to insert 'this->'. 887 // TODO: fixit for inserting 'Base<T>::' in the other cases. 888 // Actually quite difficult! 889 if (isInstance) { 890 Diag(R.getNameLoc(), diagnostic) << Name 891 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 892 893 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 894 CallsUndergoingInstantiation.back()->getCallee()); 895 CXXMethodDecl *DepMethod = cast<CXXMethodDecl>( 896 CurMethod->getInstantiatedFromMemberFunction()); 897 QualType DepThisType = DepMethod->getThisType(Context); 898 CXXThisExpr *DepThis = new (Context) CXXThisExpr(R.getNameLoc(), 899 DepThisType, false); 900 TemplateArgumentListInfo TList; 901 if (ULE->hasExplicitTemplateArgs()) 902 ULE->copyTemplateArgumentsInto(TList); 903 CXXDependentScopeMemberExpr *DepExpr = 904 CXXDependentScopeMemberExpr::Create( 905 Context, DepThis, DepThisType, true, SourceLocation(), 906 ULE->getQualifier(), ULE->getQualifierRange(), NULL, Name, 907 R.getNameLoc(), &TList); 908 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 909 } else { 910 Diag(R.getNameLoc(), diagnostic) << Name; 911 } 912 913 // Do we really want to note all of these? 914 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 915 Diag((*I)->getLocation(), diag::note_dependent_var_use); 916 917 // Tell the callee to try to recover. 918 return false; 919 } 920 } 921 } 922 923 // We didn't find anything, so try to correct for a typo. 924 DeclarationName Corrected; 925 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 926 if (!R.empty()) { 927 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 928 if (SS.isEmpty()) 929 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 930 << FixItHint::CreateReplacement(R.getNameLoc(), 931 R.getLookupName().getAsString()); 932 else 933 Diag(R.getNameLoc(), diag::err_no_member_suggest) 934 << Name << computeDeclContext(SS, false) << R.getLookupName() 935 << SS.getRange() 936 << FixItHint::CreateReplacement(R.getNameLoc(), 937 R.getLookupName().getAsString()); 938 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 939 Diag(ND->getLocation(), diag::note_previous_decl) 940 << ND->getDeclName(); 941 942 // Tell the callee to try to recover. 943 return false; 944 } 945 946 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 947 // FIXME: If we ended up with a typo for a type name or 948 // Objective-C class name, we're in trouble because the parser 949 // is in the wrong place to recover. Suggest the typo 950 // correction, but don't make it a fix-it since we're not going 951 // to recover well anyway. 952 if (SS.isEmpty()) 953 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 954 else 955 Diag(R.getNameLoc(), diag::err_no_member_suggest) 956 << Name << computeDeclContext(SS, false) << R.getLookupName() 957 << SS.getRange(); 958 959 // Don't try to recover; it won't work. 960 return true; 961 } 962 } else { 963 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 964 // because we aren't able to recover. 965 if (SS.isEmpty()) 966 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 967 else 968 Diag(R.getNameLoc(), diag::err_no_member_suggest) 969 << Name << computeDeclContext(SS, false) << Corrected 970 << SS.getRange(); 971 return true; 972 } 973 R.clear(); 974 } 975 976 // Emit a special diagnostic for failed member lookups. 977 // FIXME: computing the declaration context might fail here (?) 978 if (!SS.isEmpty()) { 979 Diag(R.getNameLoc(), diag::err_no_member) 980 << Name << computeDeclContext(SS, false) 981 << SS.getRange(); 982 return true; 983 } 984 985 // Give up, we can't recover. 986 Diag(R.getNameLoc(), diagnostic) << Name; 987 return true; 988} 989 990static ObjCPropertyDecl *OkToSynthesizeProvisionalIvar(Sema &SemaRef, 991 IdentifierInfo *II, 992 SourceLocation NameLoc) { 993 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 994 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 995 if (!IDecl) 996 return 0; 997 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 998 if (!ClassImpDecl) 999 return 0; 1000 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1001 if (!property) 1002 return 0; 1003 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1004 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic) 1005 return 0; 1006 return property; 1007} 1008 1009static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1010 LookupResult &Lookup, 1011 IdentifierInfo *II, 1012 SourceLocation NameLoc) { 1013 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1014 bool LookForIvars; 1015 if (Lookup.empty()) 1016 LookForIvars = true; 1017 else if (CurMeth->isClassMethod()) 1018 LookForIvars = false; 1019 else 1020 LookForIvars = (Lookup.isSingleResult() && 1021 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1022 if (!LookForIvars) 1023 return 0; 1024 1025 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1026 if (!IDecl) 1027 return 0; 1028 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1029 if (!ClassImpDecl) 1030 return 0; 1031 bool DynamicImplSeen = false; 1032 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1033 if (!property) 1034 return 0; 1035 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1036 DynamicImplSeen = 1037 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1038 if (!DynamicImplSeen) { 1039 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1040 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1041 NameLoc, 1042 II, PropType, /*Dinfo=*/0, 1043 ObjCIvarDecl::Protected, 1044 (Expr *)0, true); 1045 ClassImpDecl->addDecl(Ivar); 1046 IDecl->makeDeclVisibleInContext(Ivar, false); 1047 property->setPropertyIvarDecl(Ivar); 1048 return Ivar; 1049 } 1050 return 0; 1051} 1052 1053Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S, 1054 CXXScopeSpec &SS, 1055 UnqualifiedId &Id, 1056 bool HasTrailingLParen, 1057 bool isAddressOfOperand) { 1058 assert(!(isAddressOfOperand && HasTrailingLParen) && 1059 "cannot be direct & operand and have a trailing lparen"); 1060 1061 if (SS.isInvalid()) 1062 return ExprError(); 1063 1064 TemplateArgumentListInfo TemplateArgsBuffer; 1065 1066 // Decompose the UnqualifiedId into the following data. 1067 DeclarationName Name; 1068 SourceLocation NameLoc; 1069 const TemplateArgumentListInfo *TemplateArgs; 1070 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 1071 Name, NameLoc, TemplateArgs); 1072 1073 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1074 1075 // C++ [temp.dep.expr]p3: 1076 // An id-expression is type-dependent if it contains: 1077 // -- an identifier that was declared with a dependent type, 1078 // (note: handled after lookup) 1079 // -- a template-id that is dependent, 1080 // (note: handled in BuildTemplateIdExpr) 1081 // -- a conversion-function-id that specifies a dependent type, 1082 // -- a nested-name-specifier that contains a class-name that 1083 // names a dependent type. 1084 // Determine whether this is a member of an unknown specialization; 1085 // we need to handle these differently. 1086 bool DependentID = false; 1087 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1088 Name.getCXXNameType()->isDependentType()) { 1089 DependentID = true; 1090 } else if (SS.isSet()) { 1091 DeclContext *DC = computeDeclContext(SS, false); 1092 if (DC) { 1093 if (RequireCompleteDeclContext(SS, DC)) 1094 return ExprError(); 1095 // FIXME: We should be checking whether DC is the current instantiation. 1096 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 1097 DependentID = !IsFullyFormedScope(*this, RD); 1098 } else { 1099 DependentID = true; 1100 } 1101 } 1102 1103 if (DependentID) { 1104 return ActOnDependentIdExpression(SS, Name, NameLoc, 1105 isAddressOfOperand, 1106 TemplateArgs); 1107 } 1108 bool IvarLookupFollowUp = false; 1109 // Perform the required lookup. 1110 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1111 if (TemplateArgs) { 1112 // Lookup the template name again to correctly establish the context in 1113 // which it was found. This is really unfortunate as we already did the 1114 // lookup to determine that it was a template name in the first place. If 1115 // this becomes a performance hit, we can work harder to preserve those 1116 // results until we get here but it's likely not worth it. 1117 bool MemberOfUnknownSpecialization; 1118 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1119 MemberOfUnknownSpecialization); 1120 } else { 1121 IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1122 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1123 1124 // If this reference is in an Objective-C method, then we need to do 1125 // some special Objective-C lookup, too. 1126 if (IvarLookupFollowUp) { 1127 OwningExprResult E(LookupInObjCMethod(R, S, II, true)); 1128 if (E.isInvalid()) 1129 return ExprError(); 1130 1131 Expr *Ex = E.takeAs<Expr>(); 1132 if (Ex) return Owned(Ex); 1133 // Synthesize ivars lazily 1134 if (getLangOptions().ObjCNonFragileABI2) { 1135 if (SynthesizeProvisionalIvar(*this, R, II, NameLoc)) 1136 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1137 isAddressOfOperand); 1138 } 1139 } 1140 } 1141 1142 if (R.isAmbiguous()) 1143 return ExprError(); 1144 1145 // Determine whether this name might be a candidate for 1146 // argument-dependent lookup. 1147 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1148 1149 if (R.empty() && !ADL) { 1150 // Otherwise, this could be an implicitly declared function reference (legal 1151 // in C90, extension in C99, forbidden in C++). 1152 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1153 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1154 if (D) R.addDecl(D); 1155 } 1156 1157 // If this name wasn't predeclared and if this is not a function 1158 // call, diagnose the problem. 1159 if (R.empty()) { 1160 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1161 return ExprError(); 1162 1163 assert(!R.empty() && 1164 "DiagnoseEmptyLookup returned false but added no results"); 1165 1166 // If we found an Objective-C instance variable, let 1167 // LookupInObjCMethod build the appropriate expression to 1168 // reference the ivar. 1169 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1170 R.clear(); 1171 OwningExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1172 assert(E.isInvalid() || E.get()); 1173 return move(E); 1174 } 1175 } 1176 } 1177 1178 // This is guaranteed from this point on. 1179 assert(!R.empty() || ADL); 1180 1181 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1182 if (getLangOptions().ObjCNonFragileABI && IvarLookupFollowUp && 1183 !getLangOptions().ObjCNonFragileABI2 && 1184 Var->isFileVarDecl()) { 1185 ObjCPropertyDecl *Property = 1186 OkToSynthesizeProvisionalIvar(*this, II, NameLoc); 1187 if (Property) { 1188 Diag(NameLoc, diag::warn_ivar_variable_conflict) << Var->getDeclName(); 1189 Diag(Property->getLocation(), diag::note_property_declare); 1190 } 1191 } 1192 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1193 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1194 // C99 DR 316 says that, if a function type comes from a 1195 // function definition (without a prototype), that type is only 1196 // used for checking compatibility. Therefore, when referencing 1197 // the function, we pretend that we don't have the full function 1198 // type. 1199 if (DiagnoseUseOfDecl(Func, NameLoc)) 1200 return ExprError(); 1201 1202 QualType T = Func->getType(); 1203 QualType NoProtoType = T; 1204 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1205 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1206 Proto->getExtInfo()); 1207 return BuildDeclRefExpr(Func, NoProtoType, NameLoc, &SS); 1208 } 1209 } 1210 1211 // Check whether this might be a C++ implicit instance member access. 1212 // C++ [expr.prim.general]p6: 1213 // Within the definition of a non-static member function, an 1214 // identifier that names a non-static member is transformed to a 1215 // class member access expression. 1216 // But note that &SomeClass::foo is grammatically distinct, even 1217 // though we don't parse it that way. 1218 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1219 bool isAbstractMemberPointer = (isAddressOfOperand && !SS.isEmpty()); 1220 if (!isAbstractMemberPointer) 1221 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1222 } 1223 1224 if (TemplateArgs) 1225 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1226 1227 return BuildDeclarationNameExpr(SS, R, ADL); 1228} 1229 1230/// Builds an expression which might be an implicit member expression. 1231Sema::OwningExprResult 1232Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1233 LookupResult &R, 1234 const TemplateArgumentListInfo *TemplateArgs) { 1235 switch (ClassifyImplicitMemberAccess(*this, R)) { 1236 case IMA_Instance: 1237 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1238 1239 case IMA_AnonymousMember: 1240 assert(R.isSingleResult()); 1241 return BuildAnonymousStructUnionMemberReference(R.getNameLoc(), 1242 R.getAsSingle<FieldDecl>()); 1243 1244 case IMA_Mixed: 1245 case IMA_Mixed_Unrelated: 1246 case IMA_Unresolved: 1247 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1248 1249 case IMA_Static: 1250 case IMA_Mixed_StaticContext: 1251 case IMA_Unresolved_StaticContext: 1252 if (TemplateArgs) 1253 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1254 return BuildDeclarationNameExpr(SS, R, false); 1255 1256 case IMA_Error_StaticContext: 1257 case IMA_Error_Unrelated: 1258 DiagnoseInstanceReference(*this, SS, R); 1259 return ExprError(); 1260 } 1261 1262 llvm_unreachable("unexpected instance member access kind"); 1263 return ExprError(); 1264} 1265 1266/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1267/// declaration name, generally during template instantiation. 1268/// There's a large number of things which don't need to be done along 1269/// this path. 1270Sema::OwningExprResult 1271Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1272 DeclarationName Name, 1273 SourceLocation NameLoc) { 1274 DeclContext *DC; 1275 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1276 return BuildDependentDeclRefExpr(SS, Name, NameLoc, 0); 1277 1278 if (RequireCompleteDeclContext(SS, DC)) 1279 return ExprError(); 1280 1281 LookupResult R(*this, Name, NameLoc, LookupOrdinaryName); 1282 LookupQualifiedName(R, DC); 1283 1284 if (R.isAmbiguous()) 1285 return ExprError(); 1286 1287 if (R.empty()) { 1288 Diag(NameLoc, diag::err_no_member) << Name << DC << SS.getRange(); 1289 return ExprError(); 1290 } 1291 1292 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1293} 1294 1295/// LookupInObjCMethod - The parser has read a name in, and Sema has 1296/// detected that we're currently inside an ObjC method. Perform some 1297/// additional lookup. 1298/// 1299/// Ideally, most of this would be done by lookup, but there's 1300/// actually quite a lot of extra work involved. 1301/// 1302/// Returns a null sentinel to indicate trivial success. 1303Sema::OwningExprResult 1304Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1305 IdentifierInfo *II, bool AllowBuiltinCreation) { 1306 SourceLocation Loc = Lookup.getNameLoc(); 1307 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1308 1309 // There are two cases to handle here. 1) scoped lookup could have failed, 1310 // in which case we should look for an ivar. 2) scoped lookup could have 1311 // found a decl, but that decl is outside the current instance method (i.e. 1312 // a global variable). In these two cases, we do a lookup for an ivar with 1313 // this name, if the lookup sucedes, we replace it our current decl. 1314 1315 // If we're in a class method, we don't normally want to look for 1316 // ivars. But if we don't find anything else, and there's an 1317 // ivar, that's an error. 1318 bool IsClassMethod = CurMethod->isClassMethod(); 1319 1320 bool LookForIvars; 1321 if (Lookup.empty()) 1322 LookForIvars = true; 1323 else if (IsClassMethod) 1324 LookForIvars = false; 1325 else 1326 LookForIvars = (Lookup.isSingleResult() && 1327 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1328 ObjCInterfaceDecl *IFace = 0; 1329 if (LookForIvars) { 1330 IFace = CurMethod->getClassInterface(); 1331 ObjCInterfaceDecl *ClassDeclared; 1332 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1333 // Diagnose using an ivar in a class method. 1334 if (IsClassMethod) 1335 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1336 << IV->getDeclName()); 1337 1338 // If we're referencing an invalid decl, just return this as a silent 1339 // error node. The error diagnostic was already emitted on the decl. 1340 if (IV->isInvalidDecl()) 1341 return ExprError(); 1342 1343 // Check if referencing a field with __attribute__((deprecated)). 1344 if (DiagnoseUseOfDecl(IV, Loc)) 1345 return ExprError(); 1346 1347 // Diagnose the use of an ivar outside of the declaring class. 1348 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1349 ClassDeclared != IFace) 1350 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1351 1352 // FIXME: This should use a new expr for a direct reference, don't 1353 // turn this into Self->ivar, just return a BareIVarExpr or something. 1354 IdentifierInfo &II = Context.Idents.get("self"); 1355 UnqualifiedId SelfName; 1356 SelfName.setIdentifier(&II, SourceLocation()); 1357 CXXScopeSpec SelfScopeSpec; 1358 OwningExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1359 SelfName, false, false); 1360 MarkDeclarationReferenced(Loc, IV); 1361 return Owned(new (Context) 1362 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1363 SelfExpr.takeAs<Expr>(), true, true)); 1364 } 1365 } else if (CurMethod->isInstanceMethod()) { 1366 // We should warn if a local variable hides an ivar. 1367 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1368 ObjCInterfaceDecl *ClassDeclared; 1369 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1370 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1371 IFace == ClassDeclared) 1372 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1373 } 1374 } 1375 1376 if (Lookup.empty() && II && AllowBuiltinCreation) { 1377 // FIXME. Consolidate this with similar code in LookupName. 1378 if (unsigned BuiltinID = II->getBuiltinID()) { 1379 if (!(getLangOptions().CPlusPlus && 1380 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1381 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1382 S, Lookup.isForRedeclaration(), 1383 Lookup.getNameLoc()); 1384 if (D) Lookup.addDecl(D); 1385 } 1386 } 1387 } 1388 // Sentinel value saying that we didn't do anything special. 1389 return Owned((Expr*) 0); 1390} 1391 1392/// \brief Cast a base object to a member's actual type. 1393/// 1394/// Logically this happens in three phases: 1395/// 1396/// * First we cast from the base type to the naming class. 1397/// The naming class is the class into which we were looking 1398/// when we found the member; it's the qualifier type if a 1399/// qualifier was provided, and otherwise it's the base type. 1400/// 1401/// * Next we cast from the naming class to the declaring class. 1402/// If the member we found was brought into a class's scope by 1403/// a using declaration, this is that class; otherwise it's 1404/// the class declaring the member. 1405/// 1406/// * Finally we cast from the declaring class to the "true" 1407/// declaring class of the member. This conversion does not 1408/// obey access control. 1409bool 1410Sema::PerformObjectMemberConversion(Expr *&From, 1411 NestedNameSpecifier *Qualifier, 1412 NamedDecl *FoundDecl, 1413 NamedDecl *Member) { 1414 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1415 if (!RD) 1416 return false; 1417 1418 QualType DestRecordType; 1419 QualType DestType; 1420 QualType FromRecordType; 1421 QualType FromType = From->getType(); 1422 bool PointerConversions = false; 1423 if (isa<FieldDecl>(Member)) { 1424 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1425 1426 if (FromType->getAs<PointerType>()) { 1427 DestType = Context.getPointerType(DestRecordType); 1428 FromRecordType = FromType->getPointeeType(); 1429 PointerConversions = true; 1430 } else { 1431 DestType = DestRecordType; 1432 FromRecordType = FromType; 1433 } 1434 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1435 if (Method->isStatic()) 1436 return false; 1437 1438 DestType = Method->getThisType(Context); 1439 DestRecordType = DestType->getPointeeType(); 1440 1441 if (FromType->getAs<PointerType>()) { 1442 FromRecordType = FromType->getPointeeType(); 1443 PointerConversions = true; 1444 } else { 1445 FromRecordType = FromType; 1446 DestType = DestRecordType; 1447 } 1448 } else { 1449 // No conversion necessary. 1450 return false; 1451 } 1452 1453 if (DestType->isDependentType() || FromType->isDependentType()) 1454 return false; 1455 1456 // If the unqualified types are the same, no conversion is necessary. 1457 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1458 return false; 1459 1460 SourceRange FromRange = From->getSourceRange(); 1461 SourceLocation FromLoc = FromRange.getBegin(); 1462 1463 ImplicitCastExpr::ResultCategory Category = CastCategory(From); 1464 1465 // C++ [class.member.lookup]p8: 1466 // [...] Ambiguities can often be resolved by qualifying a name with its 1467 // class name. 1468 // 1469 // If the member was a qualified name and the qualified referred to a 1470 // specific base subobject type, we'll cast to that intermediate type 1471 // first and then to the object in which the member is declared. That allows 1472 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1473 // 1474 // class Base { public: int x; }; 1475 // class Derived1 : public Base { }; 1476 // class Derived2 : public Base { }; 1477 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1478 // 1479 // void VeryDerived::f() { 1480 // x = 17; // error: ambiguous base subobjects 1481 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1482 // } 1483 if (Qualifier) { 1484 QualType QType = QualType(Qualifier->getAsType(), 0); 1485 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1486 assert(QType->isRecordType() && "lookup done with non-record type"); 1487 1488 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1489 1490 // In C++98, the qualifier type doesn't actually have to be a base 1491 // type of the object type, in which case we just ignore it. 1492 // Otherwise build the appropriate casts. 1493 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1494 CXXBaseSpecifierArray BasePath; 1495 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1496 FromLoc, FromRange, &BasePath)) 1497 return true; 1498 1499 if (PointerConversions) 1500 QType = Context.getPointerType(QType); 1501 ImpCastExprToType(From, QType, CastExpr::CK_UncheckedDerivedToBase, 1502 Category, BasePath); 1503 1504 FromType = QType; 1505 FromRecordType = QRecordType; 1506 1507 // If the qualifier type was the same as the destination type, 1508 // we're done. 1509 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1510 return false; 1511 } 1512 } 1513 1514 bool IgnoreAccess = false; 1515 1516 // If we actually found the member through a using declaration, cast 1517 // down to the using declaration's type. 1518 // 1519 // Pointer equality is fine here because only one declaration of a 1520 // class ever has member declarations. 1521 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1522 assert(isa<UsingShadowDecl>(FoundDecl)); 1523 QualType URecordType = Context.getTypeDeclType( 1524 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1525 1526 // We only need to do this if the naming-class to declaring-class 1527 // conversion is non-trivial. 1528 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1529 assert(IsDerivedFrom(FromRecordType, URecordType)); 1530 CXXBaseSpecifierArray BasePath; 1531 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1532 FromLoc, FromRange, &BasePath)) 1533 return true; 1534 1535 QualType UType = URecordType; 1536 if (PointerConversions) 1537 UType = Context.getPointerType(UType); 1538 ImpCastExprToType(From, UType, CastExpr::CK_UncheckedDerivedToBase, 1539 Category, BasePath); 1540 FromType = UType; 1541 FromRecordType = URecordType; 1542 } 1543 1544 // We don't do access control for the conversion from the 1545 // declaring class to the true declaring class. 1546 IgnoreAccess = true; 1547 } 1548 1549 CXXBaseSpecifierArray BasePath; 1550 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1551 FromLoc, FromRange, &BasePath, 1552 IgnoreAccess)) 1553 return true; 1554 1555 ImpCastExprToType(From, DestType, CastExpr::CK_UncheckedDerivedToBase, 1556 Category, BasePath); 1557 return false; 1558} 1559 1560/// \brief Build a MemberExpr AST node. 1561static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1562 const CXXScopeSpec &SS, ValueDecl *Member, 1563 DeclAccessPair FoundDecl, 1564 SourceLocation Loc, QualType Ty, 1565 const TemplateArgumentListInfo *TemplateArgs = 0) { 1566 NestedNameSpecifier *Qualifier = 0; 1567 SourceRange QualifierRange; 1568 if (SS.isSet()) { 1569 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1570 QualifierRange = SS.getRange(); 1571 } 1572 1573 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1574 Member, FoundDecl, Loc, TemplateArgs, Ty); 1575} 1576 1577/// Builds an implicit member access expression. The current context 1578/// is known to be an instance method, and the given unqualified lookup 1579/// set is known to contain only instance members, at least one of which 1580/// is from an appropriate type. 1581Sema::OwningExprResult 1582Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 1583 LookupResult &R, 1584 const TemplateArgumentListInfo *TemplateArgs, 1585 bool IsKnownInstance) { 1586 assert(!R.empty() && !R.isAmbiguous()); 1587 1588 SourceLocation Loc = R.getNameLoc(); 1589 1590 // We may have found a field within an anonymous union or struct 1591 // (C++ [class.union]). 1592 // FIXME: This needs to happen post-isImplicitMemberReference? 1593 // FIXME: template-ids inside anonymous structs? 1594 if (FieldDecl *FD = R.getAsSingle<FieldDecl>()) 1595 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion()) 1596 return BuildAnonymousStructUnionMemberReference(Loc, FD); 1597 1598 // If this is known to be an instance access, go ahead and build a 1599 // 'this' expression now. 1600 DeclContext *DC = getFunctionLevelDeclContext(); 1601 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 1602 Expr *This = 0; // null signifies implicit access 1603 if (IsKnownInstance) { 1604 SourceLocation Loc = R.getNameLoc(); 1605 if (SS.getRange().isValid()) 1606 Loc = SS.getRange().getBegin(); 1607 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 1608 } 1609 1610 return BuildMemberReferenceExpr(ExprArg(*this, This), ThisType, 1611 /*OpLoc*/ SourceLocation(), 1612 /*IsArrow*/ true, 1613 SS, 1614 /*FirstQualifierInScope*/ 0, 1615 R, TemplateArgs); 1616} 1617 1618bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 1619 const LookupResult &R, 1620 bool HasTrailingLParen) { 1621 // Only when used directly as the postfix-expression of a call. 1622 if (!HasTrailingLParen) 1623 return false; 1624 1625 // Never if a scope specifier was provided. 1626 if (SS.isSet()) 1627 return false; 1628 1629 // Only in C++ or ObjC++. 1630 if (!getLangOptions().CPlusPlus) 1631 return false; 1632 1633 // Turn off ADL when we find certain kinds of declarations during 1634 // normal lookup: 1635 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1636 NamedDecl *D = *I; 1637 1638 // C++0x [basic.lookup.argdep]p3: 1639 // -- a declaration of a class member 1640 // Since using decls preserve this property, we check this on the 1641 // original decl. 1642 if (D->isCXXClassMember()) 1643 return false; 1644 1645 // C++0x [basic.lookup.argdep]p3: 1646 // -- a block-scope function declaration that is not a 1647 // using-declaration 1648 // NOTE: we also trigger this for function templates (in fact, we 1649 // don't check the decl type at all, since all other decl types 1650 // turn off ADL anyway). 1651 if (isa<UsingShadowDecl>(D)) 1652 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1653 else if (D->getDeclContext()->isFunctionOrMethod()) 1654 return false; 1655 1656 // C++0x [basic.lookup.argdep]p3: 1657 // -- a declaration that is neither a function or a function 1658 // template 1659 // And also for builtin functions. 1660 if (isa<FunctionDecl>(D)) { 1661 FunctionDecl *FDecl = cast<FunctionDecl>(D); 1662 1663 // But also builtin functions. 1664 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 1665 return false; 1666 } else if (!isa<FunctionTemplateDecl>(D)) 1667 return false; 1668 } 1669 1670 return true; 1671} 1672 1673 1674/// Diagnoses obvious problems with the use of the given declaration 1675/// as an expression. This is only actually called for lookups that 1676/// were not overloaded, and it doesn't promise that the declaration 1677/// will in fact be used. 1678static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 1679 if (isa<TypedefDecl>(D)) { 1680 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 1681 return true; 1682 } 1683 1684 if (isa<ObjCInterfaceDecl>(D)) { 1685 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 1686 return true; 1687 } 1688 1689 if (isa<NamespaceDecl>(D)) { 1690 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 1691 return true; 1692 } 1693 1694 return false; 1695} 1696 1697Sema::OwningExprResult 1698Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1699 LookupResult &R, 1700 bool NeedsADL) { 1701 // If this is a single, fully-resolved result and we don't need ADL, 1702 // just build an ordinary singleton decl ref. 1703 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 1704 return BuildDeclarationNameExpr(SS, R.getNameLoc(), R.getFoundDecl()); 1705 1706 // We only need to check the declaration if there's exactly one 1707 // result, because in the overloaded case the results can only be 1708 // functions and function templates. 1709 if (R.isSingleResult() && 1710 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 1711 return ExprError(); 1712 1713 // Otherwise, just build an unresolved lookup expression. Suppress 1714 // any lookup-related diagnostics; we'll hash these out later, when 1715 // we've picked a target. 1716 R.suppressDiagnostics(); 1717 1718 bool Dependent 1719 = UnresolvedLookupExpr::ComputeDependence(R.begin(), R.end(), 0); 1720 UnresolvedLookupExpr *ULE 1721 = UnresolvedLookupExpr::Create(Context, Dependent, R.getNamingClass(), 1722 (NestedNameSpecifier*) SS.getScopeRep(), 1723 SS.getRange(), 1724 R.getLookupName(), R.getNameLoc(), 1725 NeedsADL, R.isOverloadedResult(), 1726 R.begin(), R.end()); 1727 1728 return Owned(ULE); 1729} 1730 1731 1732/// \brief Complete semantic analysis for a reference to the given declaration. 1733Sema::OwningExprResult 1734Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 1735 SourceLocation Loc, NamedDecl *D) { 1736 assert(D && "Cannot refer to a NULL declaration"); 1737 assert(!isa<FunctionTemplateDecl>(D) && 1738 "Cannot refer unambiguously to a function template"); 1739 1740 if (CheckDeclInExpr(*this, Loc, D)) 1741 return ExprError(); 1742 1743 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 1744 // Specifically diagnose references to class templates that are missing 1745 // a template argument list. 1746 Diag(Loc, diag::err_template_decl_ref) 1747 << Template << SS.getRange(); 1748 Diag(Template->getLocation(), diag::note_template_decl_here); 1749 return ExprError(); 1750 } 1751 1752 // Make sure that we're referring to a value. 1753 ValueDecl *VD = dyn_cast<ValueDecl>(D); 1754 if (!VD) { 1755 Diag(Loc, diag::err_ref_non_value) 1756 << D << SS.getRange(); 1757 Diag(D->getLocation(), diag::note_declared_at); 1758 return ExprError(); 1759 } 1760 1761 // Check whether this declaration can be used. Note that we suppress 1762 // this check when we're going to perform argument-dependent lookup 1763 // on this function name, because this might not be the function 1764 // that overload resolution actually selects. 1765 if (DiagnoseUseOfDecl(VD, Loc)) 1766 return ExprError(); 1767 1768 // Only create DeclRefExpr's for valid Decl's. 1769 if (VD->isInvalidDecl()) 1770 return ExprError(); 1771 1772 // If the identifier reference is inside a block, and it refers to a value 1773 // that is outside the block, create a BlockDeclRefExpr instead of a 1774 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 1775 // the block is formed. 1776 // 1777 // We do not do this for things like enum constants, global variables, etc, 1778 // as they do not get snapshotted. 1779 // 1780 if (getCurBlock() && 1781 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 1782 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 1783 Diag(Loc, diag::err_ref_vm_type); 1784 Diag(D->getLocation(), diag::note_declared_at); 1785 return ExprError(); 1786 } 1787 1788 if (VD->getType()->isArrayType()) { 1789 Diag(Loc, diag::err_ref_array_type); 1790 Diag(D->getLocation(), diag::note_declared_at); 1791 return ExprError(); 1792 } 1793 1794 MarkDeclarationReferenced(Loc, VD); 1795 QualType ExprTy = VD->getType().getNonReferenceType(); 1796 // The BlocksAttr indicates the variable is bound by-reference. 1797 if (VD->getAttr<BlocksAttr>()) 1798 return Owned(new (Context) BlockDeclRefExpr(VD, ExprTy, Loc, true)); 1799 // This is to record that a 'const' was actually synthesize and added. 1800 bool constAdded = !ExprTy.isConstQualified(); 1801 // Variable will be bound by-copy, make it const within the closure. 1802 1803 ExprTy.addConst(); 1804 QualType T = VD->getType(); 1805 BlockDeclRefExpr *BDRE = new (Context) BlockDeclRefExpr(VD, 1806 ExprTy, Loc, false, 1807 constAdded); 1808 if (getLangOptions().CPlusPlus) { 1809 if (!T->isDependentType() && !T->isReferenceType()) { 1810 Expr *E = new (Context) 1811 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 1812 SourceLocation()); 1813 1814 OwningExprResult Res = PerformCopyInitialization( 1815 InitializedEntity::InitializeBlock(VD->getLocation(), 1816 T, false), 1817 SourceLocation(), 1818 Owned(E)); 1819 if (!Res.isInvalid()) { 1820 Res = MaybeCreateCXXExprWithTemporaries(move(Res)); 1821 Expr *Init = Res.takeAs<Expr>(); 1822 BDRE->setCopyConstructorExpr(Init); 1823 } 1824 } 1825 } 1826 return Owned(BDRE); 1827 } 1828 // If this reference is not in a block or if the referenced variable is 1829 // within the block, create a normal DeclRefExpr. 1830 1831 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), Loc, &SS); 1832} 1833 1834Sema::OwningExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 1835 tok::TokenKind Kind) { 1836 PredefinedExpr::IdentType IT; 1837 1838 switch (Kind) { 1839 default: assert(0 && "Unknown simple primary expr!"); 1840 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 1841 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 1842 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 1843 } 1844 1845 // Pre-defined identifiers are of type char[x], where x is the length of the 1846 // string. 1847 1848 Decl *currentDecl = getCurFunctionOrMethodDecl(); 1849 if (!currentDecl && getCurBlock()) 1850 currentDecl = getCurBlock()->TheDecl; 1851 if (!currentDecl) { 1852 Diag(Loc, diag::ext_predef_outside_function); 1853 currentDecl = Context.getTranslationUnitDecl(); 1854 } 1855 1856 QualType ResTy; 1857 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 1858 ResTy = Context.DependentTy; 1859 } else { 1860 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 1861 1862 llvm::APInt LengthI(32, Length + 1); 1863 ResTy = Context.CharTy.withConst(); 1864 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 1865 } 1866 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 1867} 1868 1869Sema::OwningExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 1870 llvm::SmallString<16> CharBuffer; 1871 bool Invalid = false; 1872 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 1873 if (Invalid) 1874 return ExprError(); 1875 1876 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 1877 PP); 1878 if (Literal.hadError()) 1879 return ExprError(); 1880 1881 QualType Ty; 1882 if (!getLangOptions().CPlusPlus) 1883 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 1884 else if (Literal.isWide()) 1885 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 1886 else if (Literal.isMultiChar()) 1887 Ty = Context.IntTy; // 'wxyz' -> int in C++. 1888 else 1889 Ty = Context.CharTy; // 'x' -> char in C++ 1890 1891 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 1892 Literal.isWide(), 1893 Ty, Tok.getLocation())); 1894} 1895 1896Action::OwningExprResult Sema::ActOnNumericConstant(const Token &Tok) { 1897 // Fast path for a single digit (which is quite common). A single digit 1898 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 1899 if (Tok.getLength() == 1) { 1900 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 1901 unsigned IntSize = Context.Target.getIntWidth(); 1902 return Owned(new (Context) IntegerLiteral(llvm::APInt(IntSize, Val-'0'), 1903 Context.IntTy, Tok.getLocation())); 1904 } 1905 1906 llvm::SmallString<512> IntegerBuffer; 1907 // Add padding so that NumericLiteralParser can overread by one character. 1908 IntegerBuffer.resize(Tok.getLength()+1); 1909 const char *ThisTokBegin = &IntegerBuffer[0]; 1910 1911 // Get the spelling of the token, which eliminates trigraphs, etc. 1912 bool Invalid = false; 1913 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 1914 if (Invalid) 1915 return ExprError(); 1916 1917 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 1918 Tok.getLocation(), PP); 1919 if (Literal.hadError) 1920 return ExprError(); 1921 1922 Expr *Res; 1923 1924 if (Literal.isFloatingLiteral()) { 1925 QualType Ty; 1926 if (Literal.isFloat) 1927 Ty = Context.FloatTy; 1928 else if (!Literal.isLong) 1929 Ty = Context.DoubleTy; 1930 else 1931 Ty = Context.LongDoubleTy; 1932 1933 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 1934 1935 using llvm::APFloat; 1936 APFloat Val(Format); 1937 1938 APFloat::opStatus result = Literal.GetFloatValue(Val); 1939 1940 // Overflow is always an error, but underflow is only an error if 1941 // we underflowed to zero (APFloat reports denormals as underflow). 1942 if ((result & APFloat::opOverflow) || 1943 ((result & APFloat::opUnderflow) && Val.isZero())) { 1944 unsigned diagnostic; 1945 llvm::SmallString<20> buffer; 1946 if (result & APFloat::opOverflow) { 1947 diagnostic = diag::warn_float_overflow; 1948 APFloat::getLargest(Format).toString(buffer); 1949 } else { 1950 diagnostic = diag::warn_float_underflow; 1951 APFloat::getSmallest(Format).toString(buffer); 1952 } 1953 1954 Diag(Tok.getLocation(), diagnostic) 1955 << Ty 1956 << llvm::StringRef(buffer.data(), buffer.size()); 1957 } 1958 1959 bool isExact = (result == APFloat::opOK); 1960 Res = new (Context) FloatingLiteral(Val, isExact, Ty, Tok.getLocation()); 1961 1962 } else if (!Literal.isIntegerLiteral()) { 1963 return ExprError(); 1964 } else { 1965 QualType Ty; 1966 1967 // long long is a C99 feature. 1968 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 1969 Literal.isLongLong) 1970 Diag(Tok.getLocation(), diag::ext_longlong); 1971 1972 // Get the value in the widest-possible width. 1973 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 1974 1975 if (Literal.GetIntegerValue(ResultVal)) { 1976 // If this value didn't fit into uintmax_t, warn and force to ull. 1977 Diag(Tok.getLocation(), diag::warn_integer_too_large); 1978 Ty = Context.UnsignedLongLongTy; 1979 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 1980 "long long is not intmax_t?"); 1981 } else { 1982 // If this value fits into a ULL, try to figure out what else it fits into 1983 // according to the rules of C99 6.4.4.1p5. 1984 1985 // Octal, Hexadecimal, and integers with a U suffix are allowed to 1986 // be an unsigned int. 1987 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 1988 1989 // Check from smallest to largest, picking the smallest type we can. 1990 unsigned Width = 0; 1991 if (!Literal.isLong && !Literal.isLongLong) { 1992 // Are int/unsigned possibilities? 1993 unsigned IntSize = Context.Target.getIntWidth(); 1994 1995 // Does it fit in a unsigned int? 1996 if (ResultVal.isIntN(IntSize)) { 1997 // Does it fit in a signed int? 1998 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 1999 Ty = Context.IntTy; 2000 else if (AllowUnsigned) 2001 Ty = Context.UnsignedIntTy; 2002 Width = IntSize; 2003 } 2004 } 2005 2006 // Are long/unsigned long possibilities? 2007 if (Ty.isNull() && !Literal.isLongLong) { 2008 unsigned LongSize = Context.Target.getLongWidth(); 2009 2010 // Does it fit in a unsigned long? 2011 if (ResultVal.isIntN(LongSize)) { 2012 // Does it fit in a signed long? 2013 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 2014 Ty = Context.LongTy; 2015 else if (AllowUnsigned) 2016 Ty = Context.UnsignedLongTy; 2017 Width = LongSize; 2018 } 2019 } 2020 2021 // Finally, check long long if needed. 2022 if (Ty.isNull()) { 2023 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2024 2025 // Does it fit in a unsigned long long? 2026 if (ResultVal.isIntN(LongLongSize)) { 2027 // Does it fit in a signed long long? 2028 if (!Literal.isUnsigned && ResultVal[LongLongSize-1] == 0) 2029 Ty = Context.LongLongTy; 2030 else if (AllowUnsigned) 2031 Ty = Context.UnsignedLongLongTy; 2032 Width = LongLongSize; 2033 } 2034 } 2035 2036 // If we still couldn't decide a type, we probably have something that 2037 // does not fit in a signed long long, but has no U suffix. 2038 if (Ty.isNull()) { 2039 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2040 Ty = Context.UnsignedLongLongTy; 2041 Width = Context.Target.getLongLongWidth(); 2042 } 2043 2044 if (ResultVal.getBitWidth() != Width) 2045 ResultVal.trunc(Width); 2046 } 2047 Res = new (Context) IntegerLiteral(ResultVal, Ty, Tok.getLocation()); 2048 } 2049 2050 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2051 if (Literal.isImaginary) 2052 Res = new (Context) ImaginaryLiteral(Res, 2053 Context.getComplexType(Res->getType())); 2054 2055 return Owned(Res); 2056} 2057 2058Action::OwningExprResult Sema::ActOnParenExpr(SourceLocation L, 2059 SourceLocation R, ExprArg Val) { 2060 Expr *E = Val.takeAs<Expr>(); 2061 assert((E != 0) && "ActOnParenExpr() missing expr"); 2062 return Owned(new (Context) ParenExpr(L, R, E)); 2063} 2064 2065/// The UsualUnaryConversions() function is *not* called by this routine. 2066/// See C99 6.3.2.1p[2-4] for more details. 2067bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2068 SourceLocation OpLoc, 2069 const SourceRange &ExprRange, 2070 bool isSizeof) { 2071 if (exprType->isDependentType()) 2072 return false; 2073 2074 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2075 // the result is the size of the referenced type." 2076 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2077 // result shall be the alignment of the referenced type." 2078 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2079 exprType = Ref->getPointeeType(); 2080 2081 // C99 6.5.3.4p1: 2082 if (exprType->isFunctionType()) { 2083 // alignof(function) is allowed as an extension. 2084 if (isSizeof) 2085 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2086 return false; 2087 } 2088 2089 // Allow sizeof(void)/alignof(void) as an extension. 2090 if (exprType->isVoidType()) { 2091 Diag(OpLoc, diag::ext_sizeof_void_type) 2092 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2093 return false; 2094 } 2095 2096 if (RequireCompleteType(OpLoc, exprType, 2097 PDiag(diag::err_sizeof_alignof_incomplete_type) 2098 << int(!isSizeof) << ExprRange)) 2099 return true; 2100 2101 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2102 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2103 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2104 << exprType << isSizeof << ExprRange; 2105 return true; 2106 } 2107 2108 if (Context.hasSameUnqualifiedType(exprType, Context.OverloadTy)) { 2109 Diag(OpLoc, diag::err_sizeof_alignof_overloaded_function_type) 2110 << !isSizeof << ExprRange; 2111 return true; 2112 } 2113 2114 return false; 2115} 2116 2117bool Sema::CheckAlignOfExpr(Expr *E, SourceLocation OpLoc, 2118 const SourceRange &ExprRange) { 2119 E = E->IgnoreParens(); 2120 2121 // alignof decl is always ok. 2122 if (isa<DeclRefExpr>(E)) 2123 return false; 2124 2125 // Cannot know anything else if the expression is dependent. 2126 if (E->isTypeDependent()) 2127 return false; 2128 2129 if (E->getBitField()) { 2130 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2131 return true; 2132 } 2133 2134 // Alignment of a field access is always okay, so long as it isn't a 2135 // bit-field. 2136 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2137 if (isa<FieldDecl>(ME->getMemberDecl())) 2138 return false; 2139 2140 return CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2141} 2142 2143/// \brief Build a sizeof or alignof expression given a type operand. 2144Action::OwningExprResult 2145Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2146 SourceLocation OpLoc, 2147 bool isSizeOf, SourceRange R) { 2148 if (!TInfo) 2149 return ExprError(); 2150 2151 QualType T = TInfo->getType(); 2152 2153 if (!T->isDependentType() && 2154 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2155 return ExprError(); 2156 2157 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2158 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2159 Context.getSizeType(), OpLoc, 2160 R.getEnd())); 2161} 2162 2163/// \brief Build a sizeof or alignof expression given an expression 2164/// operand. 2165Action::OwningExprResult 2166Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2167 bool isSizeOf, SourceRange R) { 2168 // Verify that the operand is valid. 2169 bool isInvalid = false; 2170 if (E->isTypeDependent()) { 2171 // Delay type-checking for type-dependent expressions. 2172 } else if (!isSizeOf) { 2173 isInvalid = CheckAlignOfExpr(E, OpLoc, R); 2174 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2175 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2176 isInvalid = true; 2177 } else { 2178 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2179 } 2180 2181 if (isInvalid) 2182 return ExprError(); 2183 2184 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2185 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2186 Context.getSizeType(), OpLoc, 2187 R.getEnd())); 2188} 2189 2190/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2191/// the same for @c alignof and @c __alignof 2192/// Note that the ArgRange is invalid if isType is false. 2193Action::OwningExprResult 2194Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2195 void *TyOrEx, const SourceRange &ArgRange) { 2196 // If error parsing type, ignore. 2197 if (TyOrEx == 0) return ExprError(); 2198 2199 if (isType) { 2200 TypeSourceInfo *TInfo; 2201 (void) GetTypeFromParser(TyOrEx, &TInfo); 2202 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2203 } 2204 2205 Expr *ArgEx = (Expr *)TyOrEx; 2206 Action::OwningExprResult Result 2207 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2208 2209 if (Result.isInvalid()) 2210 DeleteExpr(ArgEx); 2211 2212 return move(Result); 2213} 2214 2215QualType Sema::CheckRealImagOperand(Expr *&V, SourceLocation Loc, bool isReal) { 2216 if (V->isTypeDependent()) 2217 return Context.DependentTy; 2218 2219 // These operators return the element type of a complex type. 2220 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2221 return CT->getElementType(); 2222 2223 // Otherwise they pass through real integer and floating point types here. 2224 if (V->getType()->isArithmeticType()) 2225 return V->getType(); 2226 2227 // Reject anything else. 2228 Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2229 << (isReal ? "__real" : "__imag"); 2230 return QualType(); 2231} 2232 2233 2234 2235Action::OwningExprResult 2236Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2237 tok::TokenKind Kind, ExprArg Input) { 2238 UnaryOperator::Opcode Opc; 2239 switch (Kind) { 2240 default: assert(0 && "Unknown unary op!"); 2241 case tok::plusplus: Opc = UnaryOperator::PostInc; break; 2242 case tok::minusminus: Opc = UnaryOperator::PostDec; break; 2243 } 2244 2245 return BuildUnaryOp(S, OpLoc, Opc, move(Input)); 2246} 2247 2248Action::OwningExprResult 2249Sema::ActOnArraySubscriptExpr(Scope *S, ExprArg Base, SourceLocation LLoc, 2250 ExprArg Idx, SourceLocation RLoc) { 2251 // Since this might be a postfix expression, get rid of ParenListExprs. 2252 Base = MaybeConvertParenListExprToParenExpr(S, move(Base)); 2253 2254 Expr *LHSExp = static_cast<Expr*>(Base.get()), 2255 *RHSExp = static_cast<Expr*>(Idx.get()); 2256 2257 if (getLangOptions().CPlusPlus && 2258 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2259 Base.release(); 2260 Idx.release(); 2261 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2262 Context.DependentTy, RLoc)); 2263 } 2264 2265 if (getLangOptions().CPlusPlus && 2266 (LHSExp->getType()->isRecordType() || 2267 LHSExp->getType()->isEnumeralType() || 2268 RHSExp->getType()->isRecordType() || 2269 RHSExp->getType()->isEnumeralType())) { 2270 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, move(Base),move(Idx)); 2271 } 2272 2273 return CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 2274} 2275 2276 2277Action::OwningExprResult 2278Sema::CreateBuiltinArraySubscriptExpr(ExprArg Base, SourceLocation LLoc, 2279 ExprArg Idx, SourceLocation RLoc) { 2280 Expr *LHSExp = static_cast<Expr*>(Base.get()); 2281 Expr *RHSExp = static_cast<Expr*>(Idx.get()); 2282 2283 // Perform default conversions. 2284 if (!LHSExp->getType()->getAs<VectorType>()) 2285 DefaultFunctionArrayLvalueConversion(LHSExp); 2286 DefaultFunctionArrayLvalueConversion(RHSExp); 2287 2288 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2289 2290 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2291 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2292 // in the subscript position. As a result, we need to derive the array base 2293 // and index from the expression types. 2294 Expr *BaseExpr, *IndexExpr; 2295 QualType ResultType; 2296 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2297 BaseExpr = LHSExp; 2298 IndexExpr = RHSExp; 2299 ResultType = Context.DependentTy; 2300 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2301 BaseExpr = LHSExp; 2302 IndexExpr = RHSExp; 2303 ResultType = PTy->getPointeeType(); 2304 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2305 // Handle the uncommon case of "123[Ptr]". 2306 BaseExpr = RHSExp; 2307 IndexExpr = LHSExp; 2308 ResultType = PTy->getPointeeType(); 2309 } else if (const ObjCObjectPointerType *PTy = 2310 LHSTy->getAs<ObjCObjectPointerType>()) { 2311 BaseExpr = LHSExp; 2312 IndexExpr = RHSExp; 2313 ResultType = PTy->getPointeeType(); 2314 } else if (const ObjCObjectPointerType *PTy = 2315 RHSTy->getAs<ObjCObjectPointerType>()) { 2316 // Handle the uncommon case of "123[Ptr]". 2317 BaseExpr = RHSExp; 2318 IndexExpr = LHSExp; 2319 ResultType = PTy->getPointeeType(); 2320 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2321 BaseExpr = LHSExp; // vectors: V[123] 2322 IndexExpr = RHSExp; 2323 2324 // FIXME: need to deal with const... 2325 ResultType = VTy->getElementType(); 2326 } else if (LHSTy->isArrayType()) { 2327 // If we see an array that wasn't promoted by 2328 // DefaultFunctionArrayLvalueConversion, it must be an array that 2329 // wasn't promoted because of the C90 rule that doesn't 2330 // allow promoting non-lvalue arrays. Warn, then 2331 // force the promotion here. 2332 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2333 LHSExp->getSourceRange(); 2334 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2335 CastExpr::CK_ArrayToPointerDecay); 2336 LHSTy = LHSExp->getType(); 2337 2338 BaseExpr = LHSExp; 2339 IndexExpr = RHSExp; 2340 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2341 } else if (RHSTy->isArrayType()) { 2342 // Same as previous, except for 123[f().a] case 2343 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2344 RHSExp->getSourceRange(); 2345 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2346 CastExpr::CK_ArrayToPointerDecay); 2347 RHSTy = RHSExp->getType(); 2348 2349 BaseExpr = RHSExp; 2350 IndexExpr = LHSExp; 2351 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2352 } else { 2353 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2354 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2355 } 2356 // C99 6.5.2.1p1 2357 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) 2358 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2359 << IndexExpr->getSourceRange()); 2360 2361 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2362 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2363 && !IndexExpr->isTypeDependent()) 2364 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2365 2366 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2367 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2368 // type. Note that Functions are not objects, and that (in C99 parlance) 2369 // incomplete types are not object types. 2370 if (ResultType->isFunctionType()) { 2371 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2372 << ResultType << BaseExpr->getSourceRange(); 2373 return ExprError(); 2374 } 2375 2376 if (!ResultType->isDependentType() && 2377 RequireCompleteType(LLoc, ResultType, 2378 PDiag(diag::err_subscript_incomplete_type) 2379 << BaseExpr->getSourceRange())) 2380 return ExprError(); 2381 2382 // Diagnose bad cases where we step over interface counts. 2383 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2384 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2385 << ResultType << BaseExpr->getSourceRange(); 2386 return ExprError(); 2387 } 2388 2389 Base.release(); 2390 Idx.release(); 2391 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2392 ResultType, RLoc)); 2393} 2394 2395QualType Sema:: 2396CheckExtVectorComponent(QualType baseType, SourceLocation OpLoc, 2397 const IdentifierInfo *CompName, 2398 SourceLocation CompLoc) { 2399 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2400 // see FIXME there. 2401 // 2402 // FIXME: This logic can be greatly simplified by splitting it along 2403 // halving/not halving and reworking the component checking. 2404 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2405 2406 // The vector accessor can't exceed the number of elements. 2407 const char *compStr = CompName->getNameStart(); 2408 2409 // This flag determines whether or not the component is one of the four 2410 // special names that indicate a subset of exactly half the elements are 2411 // to be selected. 2412 bool HalvingSwizzle = false; 2413 2414 // This flag determines whether or not CompName has an 's' char prefix, 2415 // indicating that it is a string of hex values to be used as vector indices. 2416 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2417 2418 // Check that we've found one of the special components, or that the component 2419 // names must come from the same set. 2420 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2421 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2422 HalvingSwizzle = true; 2423 } else if (vecType->getPointAccessorIdx(*compStr) != -1) { 2424 do 2425 compStr++; 2426 while (*compStr && vecType->getPointAccessorIdx(*compStr) != -1); 2427 } else if (HexSwizzle || vecType->getNumericAccessorIdx(*compStr) != -1) { 2428 do 2429 compStr++; 2430 while (*compStr && vecType->getNumericAccessorIdx(*compStr) != -1); 2431 } 2432 2433 if (!HalvingSwizzle && *compStr) { 2434 // We didn't get to the end of the string. This means the component names 2435 // didn't come from the same set *or* we encountered an illegal name. 2436 Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2437 << std::string(compStr,compStr+1) << SourceRange(CompLoc); 2438 return QualType(); 2439 } 2440 2441 // Ensure no component accessor exceeds the width of the vector type it 2442 // operates on. 2443 if (!HalvingSwizzle) { 2444 compStr = CompName->getNameStart(); 2445 2446 if (HexSwizzle) 2447 compStr++; 2448 2449 while (*compStr) { 2450 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2451 Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2452 << baseType << SourceRange(CompLoc); 2453 return QualType(); 2454 } 2455 } 2456 } 2457 2458 // The component accessor looks fine - now we need to compute the actual type. 2459 // The vector type is implied by the component accessor. For example, 2460 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2461 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2462 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2463 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2464 : CompName->getLength(); 2465 if (HexSwizzle) 2466 CompSize--; 2467 2468 if (CompSize == 1) 2469 return vecType->getElementType(); 2470 2471 QualType VT = Context.getExtVectorType(vecType->getElementType(), CompSize); 2472 // Now look up the TypeDefDecl from the vector type. Without this, 2473 // diagostics look bad. We want extended vector types to appear built-in. 2474 for (unsigned i = 0, E = ExtVectorDecls.size(); i != E; ++i) { 2475 if (ExtVectorDecls[i]->getUnderlyingType() == VT) 2476 return Context.getTypedefType(ExtVectorDecls[i]); 2477 } 2478 return VT; // should never get here (a typedef type should always be found). 2479} 2480 2481static Decl *FindGetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 2482 IdentifierInfo *Member, 2483 const Selector &Sel, 2484 ASTContext &Context) { 2485 2486 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 2487 return PD; 2488 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 2489 return OMD; 2490 2491 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 2492 E = PDecl->protocol_end(); I != E; ++I) { 2493 if (Decl *D = FindGetterNameDeclFromProtocolList(*I, Member, Sel, 2494 Context)) 2495 return D; 2496 } 2497 return 0; 2498} 2499 2500static Decl *FindGetterNameDecl(const ObjCObjectPointerType *QIdTy, 2501 IdentifierInfo *Member, 2502 const Selector &Sel, 2503 ASTContext &Context) { 2504 // Check protocols on qualified interfaces. 2505 Decl *GDecl = 0; 2506 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2507 E = QIdTy->qual_end(); I != E; ++I) { 2508 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 2509 GDecl = PD; 2510 break; 2511 } 2512 // Also must look for a getter name which uses property syntax. 2513 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 2514 GDecl = OMD; 2515 break; 2516 } 2517 } 2518 if (!GDecl) { 2519 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 2520 E = QIdTy->qual_end(); I != E; ++I) { 2521 // Search in the protocol-qualifier list of current protocol. 2522 GDecl = FindGetterNameDeclFromProtocolList(*I, Member, Sel, Context); 2523 if (GDecl) 2524 return GDecl; 2525 } 2526 } 2527 return GDecl; 2528} 2529 2530Sema::OwningExprResult 2531Sema::ActOnDependentMemberExpr(ExprArg Base, QualType BaseType, 2532 bool IsArrow, SourceLocation OpLoc, 2533 const CXXScopeSpec &SS, 2534 NamedDecl *FirstQualifierInScope, 2535 DeclarationName Name, SourceLocation NameLoc, 2536 const TemplateArgumentListInfo *TemplateArgs) { 2537 Expr *BaseExpr = Base.takeAs<Expr>(); 2538 2539 // Even in dependent contexts, try to diagnose base expressions with 2540 // obviously wrong types, e.g.: 2541 // 2542 // T* t; 2543 // t.f; 2544 // 2545 // In Obj-C++, however, the above expression is valid, since it could be 2546 // accessing the 'f' property if T is an Obj-C interface. The extra check 2547 // allows this, while still reporting an error if T is a struct pointer. 2548 if (!IsArrow) { 2549 const PointerType *PT = BaseType->getAs<PointerType>(); 2550 if (PT && (!getLangOptions().ObjC1 || 2551 PT->getPointeeType()->isRecordType())) { 2552 assert(BaseExpr && "cannot happen with implicit member accesses"); 2553 Diag(NameLoc, diag::err_typecheck_member_reference_struct_union) 2554 << BaseType << BaseExpr->getSourceRange(); 2555 return ExprError(); 2556 } 2557 } 2558 2559 assert(BaseType->isDependentType() || Name.isDependentName() || 2560 isDependentScopeSpecifier(SS)); 2561 2562 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 2563 // must have pointer type, and the accessed type is the pointee. 2564 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 2565 IsArrow, OpLoc, 2566 static_cast<NestedNameSpecifier*>(SS.getScopeRep()), 2567 SS.getRange(), 2568 FirstQualifierInScope, 2569 Name, NameLoc, 2570 TemplateArgs)); 2571} 2572 2573/// We know that the given qualified member reference points only to 2574/// declarations which do not belong to the static type of the base 2575/// expression. Diagnose the problem. 2576static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 2577 Expr *BaseExpr, 2578 QualType BaseType, 2579 const CXXScopeSpec &SS, 2580 const LookupResult &R) { 2581 // If this is an implicit member access, use a different set of 2582 // diagnostics. 2583 if (!BaseExpr) 2584 return DiagnoseInstanceReference(SemaRef, SS, R); 2585 2586 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 2587 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 2588} 2589 2590// Check whether the declarations we found through a nested-name 2591// specifier in a member expression are actually members of the base 2592// type. The restriction here is: 2593// 2594// C++ [expr.ref]p2: 2595// ... In these cases, the id-expression shall name a 2596// member of the class or of one of its base classes. 2597// 2598// So it's perfectly legitimate for the nested-name specifier to name 2599// an unrelated class, and for us to find an overload set including 2600// decls from classes which are not superclasses, as long as the decl 2601// we actually pick through overload resolution is from a superclass. 2602bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 2603 QualType BaseType, 2604 const CXXScopeSpec &SS, 2605 const LookupResult &R) { 2606 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 2607 if (!BaseRT) { 2608 // We can't check this yet because the base type is still 2609 // dependent. 2610 assert(BaseType->isDependentType()); 2611 return false; 2612 } 2613 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 2614 2615 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2616 // If this is an implicit member reference and we find a 2617 // non-instance member, it's not an error. 2618 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 2619 return false; 2620 2621 // Note that we use the DC of the decl, not the underlying decl. 2622 DeclContext *DC = (*I)->getDeclContext(); 2623 while (DC->isTransparentContext()) 2624 DC = DC->getParent(); 2625 2626 if (!DC->isRecord()) 2627 continue; 2628 2629 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 2630 MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); 2631 2632 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 2633 return false; 2634 } 2635 2636 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 2637 return true; 2638} 2639 2640static bool 2641LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 2642 SourceRange BaseRange, const RecordType *RTy, 2643 SourceLocation OpLoc, CXXScopeSpec &SS, 2644 bool HasTemplateArgs) { 2645 RecordDecl *RDecl = RTy->getDecl(); 2646 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 2647 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 2648 << BaseRange)) 2649 return true; 2650 2651 if (HasTemplateArgs) { 2652 // LookupTemplateName doesn't expect these both to exist simultaneously. 2653 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 2654 2655 bool MOUS; 2656 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 2657 return false; 2658 } 2659 2660 DeclContext *DC = RDecl; 2661 if (SS.isSet()) { 2662 // If the member name was a qualified-id, look into the 2663 // nested-name-specifier. 2664 DC = SemaRef.computeDeclContext(SS, false); 2665 2666 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 2667 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 2668 << SS.getRange() << DC; 2669 return true; 2670 } 2671 2672 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 2673 2674 if (!isa<TypeDecl>(DC)) { 2675 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 2676 << DC << SS.getRange(); 2677 return true; 2678 } 2679 } 2680 2681 // The record definition is complete, now look up the member. 2682 SemaRef.LookupQualifiedName(R, DC); 2683 2684 if (!R.empty()) 2685 return false; 2686 2687 // We didn't find anything with the given name, so try to correct 2688 // for typos. 2689 DeclarationName Name = R.getLookupName(); 2690 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 2691 !R.empty() && 2692 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 2693 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 2694 << Name << DC << R.getLookupName() << SS.getRange() 2695 << FixItHint::CreateReplacement(R.getNameLoc(), 2696 R.getLookupName().getAsString()); 2697 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 2698 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 2699 << ND->getDeclName(); 2700 return false; 2701 } else { 2702 R.clear(); 2703 R.setLookupName(Name); 2704 } 2705 2706 return false; 2707} 2708 2709Sema::OwningExprResult 2710Sema::BuildMemberReferenceExpr(ExprArg BaseArg, QualType BaseType, 2711 SourceLocation OpLoc, bool IsArrow, 2712 CXXScopeSpec &SS, 2713 NamedDecl *FirstQualifierInScope, 2714 DeclarationName Name, SourceLocation NameLoc, 2715 const TemplateArgumentListInfo *TemplateArgs) { 2716 Expr *Base = BaseArg.takeAs<Expr>(); 2717 2718 if (BaseType->isDependentType() || 2719 (SS.isSet() && isDependentScopeSpecifier(SS))) 2720 return ActOnDependentMemberExpr(ExprArg(*this, Base), BaseType, 2721 IsArrow, OpLoc, 2722 SS, FirstQualifierInScope, 2723 Name, NameLoc, 2724 TemplateArgs); 2725 2726 LookupResult R(*this, Name, NameLoc, LookupMemberName); 2727 2728 // Implicit member accesses. 2729 if (!Base) { 2730 QualType RecordTy = BaseType; 2731 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 2732 if (LookupMemberExprInRecord(*this, R, SourceRange(), 2733 RecordTy->getAs<RecordType>(), 2734 OpLoc, SS, TemplateArgs != 0)) 2735 return ExprError(); 2736 2737 // Explicit member accesses. 2738 } else { 2739 OwningExprResult Result = 2740 LookupMemberExpr(R, Base, IsArrow, OpLoc, 2741 SS, /*ObjCImpDecl*/ DeclPtrTy(), TemplateArgs != 0); 2742 2743 if (Result.isInvalid()) { 2744 Owned(Base); 2745 return ExprError(); 2746 } 2747 2748 if (Result.get()) 2749 return move(Result); 2750 2751 // LookupMemberExpr can modify Base, and thus change BaseType 2752 BaseType = Base->getType(); 2753 } 2754 2755 return BuildMemberReferenceExpr(ExprArg(*this, Base), BaseType, 2756 OpLoc, IsArrow, SS, FirstQualifierInScope, 2757 R, TemplateArgs); 2758} 2759 2760Sema::OwningExprResult 2761Sema::BuildMemberReferenceExpr(ExprArg Base, QualType BaseExprType, 2762 SourceLocation OpLoc, bool IsArrow, 2763 const CXXScopeSpec &SS, 2764 NamedDecl *FirstQualifierInScope, 2765 LookupResult &R, 2766 const TemplateArgumentListInfo *TemplateArgs, 2767 bool SuppressQualifierCheck) { 2768 Expr *BaseExpr = Base.takeAs<Expr>(); 2769 QualType BaseType = BaseExprType; 2770 if (IsArrow) { 2771 assert(BaseType->isPointerType()); 2772 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 2773 } 2774 R.setBaseObjectType(BaseType); 2775 2776 NestedNameSpecifier *Qualifier = 2777 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 2778 DeclarationName MemberName = R.getLookupName(); 2779 SourceLocation MemberLoc = R.getNameLoc(); 2780 2781 if (R.isAmbiguous()) 2782 return ExprError(); 2783 2784 if (R.empty()) { 2785 // Rederive where we looked up. 2786 DeclContext *DC = (SS.isSet() 2787 ? computeDeclContext(SS, false) 2788 : BaseType->getAs<RecordType>()->getDecl()); 2789 2790 Diag(R.getNameLoc(), diag::err_no_member) 2791 << MemberName << DC 2792 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 2793 return ExprError(); 2794 } 2795 2796 // Diagnose lookups that find only declarations from a non-base 2797 // type. This is possible for either qualified lookups (which may 2798 // have been qualified with an unrelated type) or implicit member 2799 // expressions (which were found with unqualified lookup and thus 2800 // may have come from an enclosing scope). Note that it's okay for 2801 // lookup to find declarations from a non-base type as long as those 2802 // aren't the ones picked by overload resolution. 2803 if ((SS.isSet() || !BaseExpr || 2804 (isa<CXXThisExpr>(BaseExpr) && 2805 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 2806 !SuppressQualifierCheck && 2807 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 2808 return ExprError(); 2809 2810 // Construct an unresolved result if we in fact got an unresolved 2811 // result. 2812 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 2813 bool Dependent = 2814 BaseExprType->isDependentType() || 2815 R.isUnresolvableResult() || 2816 OverloadExpr::ComputeDependence(R.begin(), R.end(), TemplateArgs); 2817 2818 // Suppress any lookup-related diagnostics; we'll do these when we 2819 // pick a member. 2820 R.suppressDiagnostics(); 2821 2822 UnresolvedMemberExpr *MemExpr 2823 = UnresolvedMemberExpr::Create(Context, Dependent, 2824 R.isUnresolvableResult(), 2825 BaseExpr, BaseExprType, 2826 IsArrow, OpLoc, 2827 Qualifier, SS.getRange(), 2828 MemberName, MemberLoc, 2829 TemplateArgs, R.begin(), R.end()); 2830 2831 return Owned(MemExpr); 2832 } 2833 2834 assert(R.isSingleResult()); 2835 DeclAccessPair FoundDecl = R.begin().getPair(); 2836 NamedDecl *MemberDecl = R.getFoundDecl(); 2837 2838 // FIXME: diagnose the presence of template arguments now. 2839 2840 // If the decl being referenced had an error, return an error for this 2841 // sub-expr without emitting another error, in order to avoid cascading 2842 // error cases. 2843 if (MemberDecl->isInvalidDecl()) 2844 return ExprError(); 2845 2846 // Handle the implicit-member-access case. 2847 if (!BaseExpr) { 2848 // If this is not an instance member, convert to a non-member access. 2849 if (!MemberDecl->isCXXInstanceMember()) 2850 return BuildDeclarationNameExpr(SS, R.getNameLoc(), MemberDecl); 2851 2852 SourceLocation Loc = R.getNameLoc(); 2853 if (SS.getRange().isValid()) 2854 Loc = SS.getRange().getBegin(); 2855 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 2856 } 2857 2858 bool ShouldCheckUse = true; 2859 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 2860 // Don't diagnose the use of a virtual member function unless it's 2861 // explicitly qualified. 2862 if (MD->isVirtual() && !SS.isSet()) 2863 ShouldCheckUse = false; 2864 } 2865 2866 // Check the use of this member. 2867 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 2868 Owned(BaseExpr); 2869 return ExprError(); 2870 } 2871 2872 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) { 2873 // We may have found a field within an anonymous union or struct 2874 // (C++ [class.union]). 2875 if (cast<RecordDecl>(FD->getDeclContext())->isAnonymousStructOrUnion() && 2876 !BaseType->getAs<RecordType>()->getDecl()->isAnonymousStructOrUnion()) 2877 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 2878 BaseExpr, OpLoc); 2879 2880 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 2881 QualType MemberType = FD->getType(); 2882 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) 2883 MemberType = Ref->getPointeeType(); 2884 else { 2885 Qualifiers BaseQuals = BaseType.getQualifiers(); 2886 BaseQuals.removeObjCGCAttr(); 2887 if (FD->isMutable()) BaseQuals.removeConst(); 2888 2889 Qualifiers MemberQuals 2890 = Context.getCanonicalType(MemberType).getQualifiers(); 2891 2892 Qualifiers Combined = BaseQuals + MemberQuals; 2893 if (Combined != MemberQuals) 2894 MemberType = Context.getQualifiedType(MemberType, Combined); 2895 } 2896 2897 MarkDeclarationReferenced(MemberLoc, FD); 2898 if (PerformObjectMemberConversion(BaseExpr, Qualifier, FoundDecl, FD)) 2899 return ExprError(); 2900 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2901 FD, FoundDecl, MemberLoc, MemberType)); 2902 } 2903 2904 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 2905 MarkDeclarationReferenced(MemberLoc, Var); 2906 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2907 Var, FoundDecl, MemberLoc, 2908 Var->getType().getNonReferenceType())); 2909 } 2910 2911 if (FunctionDecl *MemberFn = dyn_cast<FunctionDecl>(MemberDecl)) { 2912 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2913 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2914 MemberFn, FoundDecl, MemberLoc, 2915 MemberFn->getType())); 2916 } 2917 2918 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 2919 MarkDeclarationReferenced(MemberLoc, MemberDecl); 2920 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 2921 Enum, FoundDecl, MemberLoc, Enum->getType())); 2922 } 2923 2924 Owned(BaseExpr); 2925 2926 // We found something that we didn't expect. Complain. 2927 if (isa<TypeDecl>(MemberDecl)) 2928 Diag(MemberLoc,diag::err_typecheck_member_reference_type) 2929 << MemberName << BaseType << int(IsArrow); 2930 else 2931 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 2932 << MemberName << BaseType << int(IsArrow); 2933 2934 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 2935 << MemberName; 2936 R.suppressDiagnostics(); 2937 return ExprError(); 2938} 2939 2940/// Look up the given member of the given non-type-dependent 2941/// expression. This can return in one of two ways: 2942/// * If it returns a sentinel null-but-valid result, the caller will 2943/// assume that lookup was performed and the results written into 2944/// the provided structure. It will take over from there. 2945/// * Otherwise, the returned expression will be produced in place of 2946/// an ordinary member expression. 2947/// 2948/// The ObjCImpDecl bit is a gross hack that will need to be properly 2949/// fixed for ObjC++. 2950Sema::OwningExprResult 2951Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 2952 bool &IsArrow, SourceLocation OpLoc, 2953 CXXScopeSpec &SS, 2954 DeclPtrTy ObjCImpDecl, bool HasTemplateArgs) { 2955 assert(BaseExpr && "no base expression"); 2956 2957 // Perform default conversions. 2958 DefaultFunctionArrayConversion(BaseExpr); 2959 2960 QualType BaseType = BaseExpr->getType(); 2961 assert(!BaseType->isDependentType()); 2962 2963 DeclarationName MemberName = R.getLookupName(); 2964 SourceLocation MemberLoc = R.getNameLoc(); 2965 2966 // If the user is trying to apply -> or . to a function pointer 2967 // type, it's probably because they forgot parentheses to call that 2968 // function. Suggest the addition of those parentheses, build the 2969 // call, and continue on. 2970 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 2971 if (const FunctionProtoType *Fun 2972 = Ptr->getPointeeType()->getAs<FunctionProtoType>()) { 2973 QualType ResultTy = Fun->getResultType(); 2974 if (Fun->getNumArgs() == 0 && 2975 ((!IsArrow && ResultTy->isRecordType()) || 2976 (IsArrow && ResultTy->isPointerType() && 2977 ResultTy->getAs<PointerType>()->getPointeeType() 2978 ->isRecordType()))) { 2979 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 2980 Diag(Loc, diag::err_member_reference_needs_call) 2981 << QualType(Fun, 0) 2982 << FixItHint::CreateInsertion(Loc, "()"); 2983 2984 OwningExprResult NewBase 2985 = ActOnCallExpr(0, ExprArg(*this, BaseExpr), Loc, 2986 MultiExprArg(*this, 0, 0), 0, Loc); 2987 BaseExpr = 0; 2988 if (NewBase.isInvalid()) 2989 return ExprError(); 2990 2991 BaseExpr = NewBase.takeAs<Expr>(); 2992 DefaultFunctionArrayConversion(BaseExpr); 2993 BaseType = BaseExpr->getType(); 2994 } 2995 } 2996 } 2997 2998 // If this is an Objective-C pseudo-builtin and a definition is provided then 2999 // use that. 3000 if (BaseType->isObjCIdType()) { 3001 if (IsArrow) { 3002 // Handle the following exceptional case PObj->isa. 3003 if (const ObjCObjectPointerType *OPT = 3004 BaseType->getAs<ObjCObjectPointerType>()) { 3005 if (OPT->getObjectType()->isObjCId() && 3006 MemberName.getAsIdentifierInfo()->isStr("isa")) 3007 return Owned(new (Context) ObjCIsaExpr(BaseExpr, true, MemberLoc, 3008 Context.getObjCClassType())); 3009 } 3010 } 3011 // We have an 'id' type. Rather than fall through, we check if this 3012 // is a reference to 'isa'. 3013 if (BaseType != Context.ObjCIdRedefinitionType) { 3014 BaseType = Context.ObjCIdRedefinitionType; 3015 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3016 } 3017 } 3018 3019 // If this is an Objective-C pseudo-builtin and a definition is provided then 3020 // use that. 3021 if (Context.isObjCSelType(BaseType)) { 3022 // We have an 'SEL' type. Rather than fall through, we check if this 3023 // is a reference to 'sel_id'. 3024 if (BaseType != Context.ObjCSelRedefinitionType) { 3025 BaseType = Context.ObjCSelRedefinitionType; 3026 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3027 } 3028 } 3029 3030 assert(!BaseType.isNull() && "no type for member expression"); 3031 3032 // Handle properties on ObjC 'Class' types. 3033 if (!IsArrow && BaseType->isObjCClassType()) { 3034 // Also must look for a getter name which uses property syntax. 3035 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3036 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3037 if (ObjCMethodDecl *MD = getCurMethodDecl()) { 3038 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3039 ObjCMethodDecl *Getter; 3040 // FIXME: need to also look locally in the implementation. 3041 if ((Getter = IFace->lookupClassMethod(Sel))) { 3042 // Check the use of this method. 3043 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3044 return ExprError(); 3045 } 3046 // If we found a getter then this may be a valid dot-reference, we 3047 // will look for the matching setter, in case it is needed. 3048 Selector SetterSel = 3049 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3050 PP.getSelectorTable(), Member); 3051 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3052 if (!Setter) { 3053 // If this reference is in an @implementation, also check for 'private' 3054 // methods. 3055 Setter = IFace->lookupPrivateInstanceMethod(SetterSel); 3056 } 3057 // Look through local category implementations associated with the class. 3058 if (!Setter) 3059 Setter = IFace->getCategoryClassMethod(SetterSel); 3060 3061 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3062 return ExprError(); 3063 3064 if (Getter || Setter) { 3065 QualType PType; 3066 3067 if (Getter) 3068 PType = Getter->getSendResultType(); 3069 else 3070 // Get the expression type from Setter's incoming parameter. 3071 PType = (*(Setter->param_end() -1))->getType(); 3072 // FIXME: we must check that the setter has property type. 3073 return Owned(new (Context) ObjCImplicitSetterGetterRefExpr(Getter, 3074 PType, 3075 Setter, MemberLoc, BaseExpr)); 3076 } 3077 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3078 << MemberName << BaseType); 3079 } 3080 } 3081 3082 if (BaseType->isObjCClassType() && 3083 BaseType != Context.ObjCClassRedefinitionType) { 3084 BaseType = Context.ObjCClassRedefinitionType; 3085 ImpCastExprToType(BaseExpr, BaseType, CastExpr::CK_BitCast); 3086 } 3087 3088 if (IsArrow) { 3089 if (const PointerType *PT = BaseType->getAs<PointerType>()) 3090 BaseType = PT->getPointeeType(); 3091 else if (BaseType->isObjCObjectPointerType()) 3092 ; 3093 else if (BaseType->isRecordType()) { 3094 // Recover from arrow accesses to records, e.g.: 3095 // struct MyRecord foo; 3096 // foo->bar 3097 // This is actually well-formed in C++ if MyRecord has an 3098 // overloaded operator->, but that should have been dealt with 3099 // by now. 3100 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3101 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3102 << FixItHint::CreateReplacement(OpLoc, "."); 3103 IsArrow = false; 3104 } else { 3105 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3106 << BaseType << BaseExpr->getSourceRange(); 3107 return ExprError(); 3108 } 3109 } else { 3110 // Recover from dot accesses to pointers, e.g.: 3111 // type *foo; 3112 // foo.bar 3113 // This is actually well-formed in two cases: 3114 // - 'type' is an Objective C type 3115 // - 'bar' is a pseudo-destructor name which happens to refer to 3116 // the appropriate pointer type 3117 if (MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3118 const PointerType *PT = BaseType->getAs<PointerType>(); 3119 if (PT && PT->getPointeeType()->isRecordType()) { 3120 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3121 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3122 << FixItHint::CreateReplacement(OpLoc, "->"); 3123 BaseType = PT->getPointeeType(); 3124 IsArrow = true; 3125 } 3126 } 3127 } 3128 3129 // Handle field access to simple records. 3130 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3131 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3132 RTy, OpLoc, SS, HasTemplateArgs)) 3133 return ExprError(); 3134 return Owned((Expr*) 0); 3135 } 3136 3137 // Handle access to Objective-C instance variables, such as "Obj->ivar" and 3138 // (*Obj).ivar. 3139 if ((IsArrow && BaseType->isObjCObjectPointerType()) || 3140 (!IsArrow && BaseType->isObjCObjectType())) { 3141 const ObjCObjectPointerType *OPT = BaseType->getAs<ObjCObjectPointerType>(); 3142 ObjCInterfaceDecl *IDecl = 3143 OPT ? OPT->getInterfaceDecl() 3144 : BaseType->getAs<ObjCObjectType>()->getInterface(); 3145 if (IDecl) { 3146 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3147 3148 ObjCInterfaceDecl *ClassDeclared; 3149 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3150 3151 if (!IV) { 3152 // Attempt to correct for typos in ivar names. 3153 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3154 LookupMemberName); 3155 if (CorrectTypo(Res, 0, 0, IDecl, false, CTC_MemberLookup) && 3156 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3157 Diag(R.getNameLoc(), 3158 diag::err_typecheck_member_reference_ivar_suggest) 3159 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3160 << FixItHint::CreateReplacement(R.getNameLoc(), 3161 IV->getNameAsString()); 3162 Diag(IV->getLocation(), diag::note_previous_decl) 3163 << IV->getDeclName(); 3164 } else { 3165 Res.clear(); 3166 Res.setLookupName(Member); 3167 } 3168 } 3169 3170 if (IV) { 3171 // If the decl being referenced had an error, return an error for this 3172 // sub-expr without emitting another error, in order to avoid cascading 3173 // error cases. 3174 if (IV->isInvalidDecl()) 3175 return ExprError(); 3176 3177 // Check whether we can reference this field. 3178 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3179 return ExprError(); 3180 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3181 IV->getAccessControl() != ObjCIvarDecl::Package) { 3182 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3183 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3184 ClassOfMethodDecl = MD->getClassInterface(); 3185 else if (ObjCImpDecl && getCurFunctionDecl()) { 3186 // Case of a c-function declared inside an objc implementation. 3187 // FIXME: For a c-style function nested inside an objc implementation 3188 // class, there is no implementation context available, so we pass 3189 // down the context as argument to this routine. Ideally, this context 3190 // need be passed down in the AST node and somehow calculated from the 3191 // AST for a function decl. 3192 Decl *ImplDecl = ObjCImpDecl.getAs<Decl>(); 3193 if (ObjCImplementationDecl *IMPD = 3194 dyn_cast<ObjCImplementationDecl>(ImplDecl)) 3195 ClassOfMethodDecl = IMPD->getClassInterface(); 3196 else if (ObjCCategoryImplDecl* CatImplClass = 3197 dyn_cast<ObjCCategoryImplDecl>(ImplDecl)) 3198 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3199 } 3200 3201 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3202 if (ClassDeclared != IDecl || 3203 ClassOfMethodDecl != ClassDeclared) 3204 Diag(MemberLoc, diag::error_private_ivar_access) 3205 << IV->getDeclName(); 3206 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3207 // @protected 3208 Diag(MemberLoc, diag::error_protected_ivar_access) 3209 << IV->getDeclName(); 3210 } 3211 3212 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3213 MemberLoc, BaseExpr, 3214 IsArrow)); 3215 } 3216 return ExprError(Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3217 << IDecl->getDeclName() << MemberName 3218 << BaseExpr->getSourceRange()); 3219 } 3220 } 3221 // Handle properties on 'id' and qualified "id". 3222 if (!IsArrow && (BaseType->isObjCIdType() || 3223 BaseType->isObjCQualifiedIdType())) { 3224 const ObjCObjectPointerType *QIdTy = BaseType->getAs<ObjCObjectPointerType>(); 3225 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3226 3227 // Check protocols on qualified interfaces. 3228 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3229 if (Decl *PMDecl = FindGetterNameDecl(QIdTy, Member, Sel, Context)) { 3230 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3231 // Check the use of this declaration 3232 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3233 return ExprError(); 3234 3235 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3236 MemberLoc, BaseExpr)); 3237 } 3238 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3239 // Check the use of this method. 3240 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3241 return ExprError(); 3242 3243 return Owned(ObjCMessageExpr::Create(Context, 3244 OMD->getSendResultType(), 3245 OpLoc, BaseExpr, Sel, 3246 OMD, NULL, 0, MemberLoc)); 3247 } 3248 } 3249 3250 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3251 << MemberName << BaseType); 3252 } 3253 3254 // Handle Objective-C property access, which is "Obj.property" where Obj is a 3255 // pointer to a (potentially qualified) interface type. 3256 if (!IsArrow) 3257 if (const ObjCObjectPointerType *OPT = 3258 BaseType->getAsObjCInterfacePointerType()) 3259 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc); 3260 3261 // Handle the following exceptional case (*Obj).isa. 3262 if (!IsArrow && 3263 BaseType->isObjCObjectType() && 3264 BaseType->getAs<ObjCObjectType>()->isObjCId() && 3265 MemberName.getAsIdentifierInfo()->isStr("isa")) 3266 return Owned(new (Context) ObjCIsaExpr(BaseExpr, false, MemberLoc, 3267 Context.getObjCClassType())); 3268 3269 // Handle 'field access' to vectors, such as 'V.xx'. 3270 if (BaseType->isExtVectorType()) { 3271 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3272 QualType ret = CheckExtVectorComponent(BaseType, OpLoc, Member, MemberLoc); 3273 if (ret.isNull()) 3274 return ExprError(); 3275 return Owned(new (Context) ExtVectorElementExpr(ret, BaseExpr, *Member, 3276 MemberLoc)); 3277 } 3278 3279 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3280 << BaseType << BaseExpr->getSourceRange(); 3281 3282 return ExprError(); 3283} 3284 3285/// The main callback when the parser finds something like 3286/// expression . [nested-name-specifier] identifier 3287/// expression -> [nested-name-specifier] identifier 3288/// where 'identifier' encompasses a fairly broad spectrum of 3289/// possibilities, including destructor and operator references. 3290/// 3291/// \param OpKind either tok::arrow or tok::period 3292/// \param HasTrailingLParen whether the next token is '(', which 3293/// is used to diagnose mis-uses of special members that can 3294/// only be called 3295/// \param ObjCImpDecl the current ObjC @implementation decl; 3296/// this is an ugly hack around the fact that ObjC @implementations 3297/// aren't properly put in the context chain 3298Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, ExprArg BaseArg, 3299 SourceLocation OpLoc, 3300 tok::TokenKind OpKind, 3301 CXXScopeSpec &SS, 3302 UnqualifiedId &Id, 3303 DeclPtrTy ObjCImpDecl, 3304 bool HasTrailingLParen) { 3305 if (SS.isSet() && SS.isInvalid()) 3306 return ExprError(); 3307 3308 TemplateArgumentListInfo TemplateArgsBuffer; 3309 3310 // Decompose the name into its component parts. 3311 DeclarationName Name; 3312 SourceLocation NameLoc; 3313 const TemplateArgumentListInfo *TemplateArgs; 3314 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3315 Name, NameLoc, TemplateArgs); 3316 3317 bool IsArrow = (OpKind == tok::arrow); 3318 3319 NamedDecl *FirstQualifierInScope 3320 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3321 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3322 3323 // This is a postfix expression, so get rid of ParenListExprs. 3324 BaseArg = MaybeConvertParenListExprToParenExpr(S, move(BaseArg)); 3325 3326 Expr *Base = BaseArg.takeAs<Expr>(); 3327 OwningExprResult Result(*this); 3328 if (Base->getType()->isDependentType() || Name.isDependentName() || 3329 isDependentScopeSpecifier(SS)) { 3330 Result = ActOnDependentMemberExpr(ExprArg(*this, Base), Base->getType(), 3331 IsArrow, OpLoc, 3332 SS, FirstQualifierInScope, 3333 Name, NameLoc, 3334 TemplateArgs); 3335 } else { 3336 LookupResult R(*this, Name, NameLoc, LookupMemberName); 3337 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3338 SS, ObjCImpDecl, TemplateArgs != 0); 3339 3340 if (Result.isInvalid()) { 3341 Owned(Base); 3342 return ExprError(); 3343 } 3344 3345 if (Result.get()) { 3346 // The only way a reference to a destructor can be used is to 3347 // immediately call it, which falls into this case. If the 3348 // next token is not a '(', produce a diagnostic and build the 3349 // call now. 3350 if (!HasTrailingLParen && 3351 Id.getKind() == UnqualifiedId::IK_DestructorName) 3352 return DiagnoseDtorReference(NameLoc, move(Result)); 3353 3354 return move(Result); 3355 } 3356 3357 Result = BuildMemberReferenceExpr(ExprArg(*this, Base), Base->getType(), 3358 OpLoc, IsArrow, SS, FirstQualifierInScope, 3359 R, TemplateArgs); 3360 } 3361 3362 return move(Result); 3363} 3364 3365Sema::OwningExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3366 FunctionDecl *FD, 3367 ParmVarDecl *Param) { 3368 if (Param->hasUnparsedDefaultArg()) { 3369 Diag (CallLoc, 3370 diag::err_use_of_default_argument_to_function_declared_later) << 3371 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3372 Diag(UnparsedDefaultArgLocs[Param], 3373 diag::note_default_argument_declared_here); 3374 } else { 3375 if (Param->hasUninstantiatedDefaultArg()) { 3376 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3377 3378 // Instantiate the expression. 3379 MultiLevelTemplateArgumentList ArgList 3380 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3381 3382 std::pair<const TemplateArgument *, unsigned> Innermost 3383 = ArgList.getInnermost(); 3384 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3385 Innermost.second); 3386 3387 OwningExprResult Result = SubstExpr(UninstExpr, ArgList); 3388 if (Result.isInvalid()) 3389 return ExprError(); 3390 3391 // Check the expression as an initializer for the parameter. 3392 InitializedEntity Entity 3393 = InitializedEntity::InitializeParameter(Param); 3394 InitializationKind Kind 3395 = InitializationKind::CreateCopy(Param->getLocation(), 3396 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 3397 Expr *ResultE = Result.takeAs<Expr>(); 3398 3399 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 3400 Result = InitSeq.Perform(*this, Entity, Kind, 3401 MultiExprArg(*this, (void**)&ResultE, 1)); 3402 if (Result.isInvalid()) 3403 return ExprError(); 3404 3405 // Build the default argument expression. 3406 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 3407 Result.takeAs<Expr>())); 3408 } 3409 3410 // If the default expression creates temporaries, we need to 3411 // push them to the current stack of expression temporaries so they'll 3412 // be properly destroyed. 3413 // FIXME: We should really be rebuilding the default argument with new 3414 // bound temporaries; see the comment in PR5810. 3415 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) 3416 ExprTemporaries.push_back(Param->getDefaultArgTemporary(i)); 3417 } 3418 3419 // We already type-checked the argument, so we know it works. 3420 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 3421} 3422 3423/// ConvertArgumentsForCall - Converts the arguments specified in 3424/// Args/NumArgs to the parameter types of the function FDecl with 3425/// function prototype Proto. Call is the call expression itself, and 3426/// Fn is the function expression. For a C++ member function, this 3427/// routine does not attempt to convert the object argument. Returns 3428/// true if the call is ill-formed. 3429bool 3430Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 3431 FunctionDecl *FDecl, 3432 const FunctionProtoType *Proto, 3433 Expr **Args, unsigned NumArgs, 3434 SourceLocation RParenLoc) { 3435 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 3436 // assignment, to the types of the corresponding parameter, ... 3437 unsigned NumArgsInProto = Proto->getNumArgs(); 3438 bool Invalid = false; 3439 3440 // If too few arguments are available (and we don't have default 3441 // arguments for the remaining parameters), don't make the call. 3442 if (NumArgs < NumArgsInProto) { 3443 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 3444 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 3445 << Fn->getType()->isBlockPointerType() 3446 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 3447 Call->setNumArgs(Context, NumArgsInProto); 3448 } 3449 3450 // If too many are passed and not variadic, error on the extras and drop 3451 // them. 3452 if (NumArgs > NumArgsInProto) { 3453 if (!Proto->isVariadic()) { 3454 Diag(Args[NumArgsInProto]->getLocStart(), 3455 diag::err_typecheck_call_too_many_args) 3456 << Fn->getType()->isBlockPointerType() 3457 << NumArgsInProto << NumArgs << Fn->getSourceRange() 3458 << SourceRange(Args[NumArgsInProto]->getLocStart(), 3459 Args[NumArgs-1]->getLocEnd()); 3460 // This deletes the extra arguments. 3461 Call->setNumArgs(Context, NumArgsInProto); 3462 return true; 3463 } 3464 } 3465 llvm::SmallVector<Expr *, 8> AllArgs; 3466 VariadicCallType CallType = 3467 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 3468 if (Fn->getType()->isBlockPointerType()) 3469 CallType = VariadicBlock; // Block 3470 else if (isa<MemberExpr>(Fn)) 3471 CallType = VariadicMethod; 3472 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 3473 Proto, 0, Args, NumArgs, AllArgs, CallType); 3474 if (Invalid) 3475 return true; 3476 unsigned TotalNumArgs = AllArgs.size(); 3477 for (unsigned i = 0; i < TotalNumArgs; ++i) 3478 Call->setArg(i, AllArgs[i]); 3479 3480 return false; 3481} 3482 3483bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 3484 FunctionDecl *FDecl, 3485 const FunctionProtoType *Proto, 3486 unsigned FirstProtoArg, 3487 Expr **Args, unsigned NumArgs, 3488 llvm::SmallVector<Expr *, 8> &AllArgs, 3489 VariadicCallType CallType) { 3490 unsigned NumArgsInProto = Proto->getNumArgs(); 3491 unsigned NumArgsToCheck = NumArgs; 3492 bool Invalid = false; 3493 if (NumArgs != NumArgsInProto) 3494 // Use default arguments for missing arguments 3495 NumArgsToCheck = NumArgsInProto; 3496 unsigned ArgIx = 0; 3497 // Continue to check argument types (even if we have too few/many args). 3498 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 3499 QualType ProtoArgType = Proto->getArgType(i); 3500 3501 Expr *Arg; 3502 if (ArgIx < NumArgs) { 3503 Arg = Args[ArgIx++]; 3504 3505 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3506 ProtoArgType, 3507 PDiag(diag::err_call_incomplete_argument) 3508 << Arg->getSourceRange())) 3509 return true; 3510 3511 // Pass the argument 3512 ParmVarDecl *Param = 0; 3513 if (FDecl && i < FDecl->getNumParams()) 3514 Param = FDecl->getParamDecl(i); 3515 3516 3517 InitializedEntity Entity = 3518 Param? InitializedEntity::InitializeParameter(Param) 3519 : InitializedEntity::InitializeParameter(ProtoArgType); 3520 OwningExprResult ArgE = PerformCopyInitialization(Entity, 3521 SourceLocation(), 3522 Owned(Arg)); 3523 if (ArgE.isInvalid()) 3524 return true; 3525 3526 Arg = ArgE.takeAs<Expr>(); 3527 } else { 3528 ParmVarDecl *Param = FDecl->getParamDecl(i); 3529 3530 OwningExprResult ArgExpr = 3531 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 3532 if (ArgExpr.isInvalid()) 3533 return true; 3534 3535 Arg = ArgExpr.takeAs<Expr>(); 3536 } 3537 AllArgs.push_back(Arg); 3538 } 3539 3540 // If this is a variadic call, handle args passed through "...". 3541 if (CallType != VariadicDoesNotApply) { 3542 // Promote the arguments (C99 6.5.2.2p7). 3543 for (unsigned i = ArgIx; i != NumArgs; ++i) { 3544 Expr *Arg = Args[i]; 3545 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 3546 AllArgs.push_back(Arg); 3547 } 3548 } 3549 return Invalid; 3550} 3551 3552/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 3553/// This provides the location of the left/right parens and a list of comma 3554/// locations. 3555Action::OwningExprResult 3556Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc, 3557 MultiExprArg args, 3558 SourceLocation *CommaLocs, SourceLocation RParenLoc) { 3559 unsigned NumArgs = args.size(); 3560 3561 // Since this might be a postfix expression, get rid of ParenListExprs. 3562 fn = MaybeConvertParenListExprToParenExpr(S, move(fn)); 3563 3564 Expr *Fn = fn.takeAs<Expr>(); 3565 Expr **Args = reinterpret_cast<Expr**>(args.release()); 3566 assert(Fn && "no function call expression"); 3567 3568 if (getLangOptions().CPlusPlus) { 3569 // If this is a pseudo-destructor expression, build the call immediately. 3570 if (isa<CXXPseudoDestructorExpr>(Fn)) { 3571 if (NumArgs > 0) { 3572 // Pseudo-destructor calls should not have any arguments. 3573 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 3574 << FixItHint::CreateRemoval( 3575 SourceRange(Args[0]->getLocStart(), 3576 Args[NumArgs-1]->getLocEnd())); 3577 3578 NumArgs = 0; 3579 } 3580 3581 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 3582 RParenLoc)); 3583 } 3584 3585 // Determine whether this is a dependent call inside a C++ template, 3586 // in which case we won't do any semantic analysis now. 3587 // FIXME: Will need to cache the results of name lookup (including ADL) in 3588 // Fn. 3589 bool Dependent = false; 3590 if (Fn->isTypeDependent()) 3591 Dependent = true; 3592 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 3593 Dependent = true; 3594 3595 if (Dependent) 3596 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 3597 Context.DependentTy, RParenLoc)); 3598 3599 // Determine whether this is a call to an object (C++ [over.call.object]). 3600 if (Fn->getType()->isRecordType()) 3601 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 3602 CommaLocs, RParenLoc)); 3603 3604 Expr *NakedFn = Fn->IgnoreParens(); 3605 3606 // Determine whether this is a call to an unresolved member function. 3607 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 3608 // If lookup was unresolved but not dependent (i.e. didn't find 3609 // an unresolved using declaration), it has to be an overloaded 3610 // function set, which means it must contain either multiple 3611 // declarations (all methods or method templates) or a single 3612 // method template. 3613 assert((MemE->getNumDecls() > 1) || 3614 isa<FunctionTemplateDecl>( 3615 (*MemE->decls_begin())->getUnderlyingDecl())); 3616 (void)MemE; 3617 3618 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3619 CommaLocs, RParenLoc); 3620 } 3621 3622 // Determine whether this is a call to a member function. 3623 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 3624 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 3625 if (isa<CXXMethodDecl>(MemDecl)) 3626 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 3627 CommaLocs, RParenLoc); 3628 } 3629 3630 // Determine whether this is a call to a pointer-to-member function. 3631 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 3632 if (BO->getOpcode() == BinaryOperator::PtrMemD || 3633 BO->getOpcode() == BinaryOperator::PtrMemI) { 3634 if (const FunctionProtoType *FPT 3635 = BO->getType()->getAs<FunctionProtoType>()) { 3636 QualType ResultTy = FPT->getCallResultType(Context); 3637 3638 ExprOwningPtr<CXXMemberCallExpr> 3639 TheCall(this, new (Context) CXXMemberCallExpr(Context, BO, Args, 3640 NumArgs, ResultTy, 3641 RParenLoc)); 3642 3643 if (CheckCallReturnType(FPT->getResultType(), 3644 BO->getRHS()->getSourceRange().getBegin(), 3645 TheCall.get(), 0)) 3646 return ExprError(); 3647 3648 if (ConvertArgumentsForCall(&*TheCall, BO, 0, FPT, Args, NumArgs, 3649 RParenLoc)) 3650 return ExprError(); 3651 3652 return Owned(MaybeBindToTemporary(TheCall.release()).release()); 3653 } 3654 return ExprError(Diag(Fn->getLocStart(), 3655 diag::err_typecheck_call_not_function) 3656 << Fn->getType() << Fn->getSourceRange()); 3657 } 3658 } 3659 } 3660 3661 // If we're directly calling a function, get the appropriate declaration. 3662 // Also, in C++, keep track of whether we should perform argument-dependent 3663 // lookup and whether there were any explicitly-specified template arguments. 3664 3665 Expr *NakedFn = Fn->IgnoreParens(); 3666 if (isa<UnresolvedLookupExpr>(NakedFn)) { 3667 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 3668 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 3669 CommaLocs, RParenLoc); 3670 } 3671 3672 NamedDecl *NDecl = 0; 3673 if (isa<DeclRefExpr>(NakedFn)) 3674 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 3675 3676 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 3677} 3678 3679/// BuildResolvedCallExpr - Build a call to a resolved expression, 3680/// i.e. an expression not of \p OverloadTy. The expression should 3681/// unary-convert to an expression of function-pointer or 3682/// block-pointer type. 3683/// 3684/// \param NDecl the declaration being called, if available 3685Sema::OwningExprResult 3686Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 3687 SourceLocation LParenLoc, 3688 Expr **Args, unsigned NumArgs, 3689 SourceLocation RParenLoc) { 3690 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 3691 3692 // Promote the function operand. 3693 UsualUnaryConversions(Fn); 3694 3695 // Make the call expr early, before semantic checks. This guarantees cleanup 3696 // of arguments and function on error. 3697 ExprOwningPtr<CallExpr> TheCall(this, new (Context) CallExpr(Context, Fn, 3698 Args, NumArgs, 3699 Context.BoolTy, 3700 RParenLoc)); 3701 3702 const FunctionType *FuncT; 3703 if (!Fn->getType()->isBlockPointerType()) { 3704 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 3705 // have type pointer to function". 3706 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 3707 if (PT == 0) 3708 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3709 << Fn->getType() << Fn->getSourceRange()); 3710 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 3711 } else { // This is a block call. 3712 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 3713 getAs<FunctionType>(); 3714 } 3715 if (FuncT == 0) 3716 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 3717 << Fn->getType() << Fn->getSourceRange()); 3718 3719 // Check for a valid return type 3720 if (CheckCallReturnType(FuncT->getResultType(), 3721 Fn->getSourceRange().getBegin(), TheCall.get(), 3722 FDecl)) 3723 return ExprError(); 3724 3725 // We know the result type of the call, set it. 3726 TheCall->setType(FuncT->getCallResultType(Context)); 3727 3728 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 3729 if (ConvertArgumentsForCall(&*TheCall, Fn, FDecl, Proto, Args, NumArgs, 3730 RParenLoc)) 3731 return ExprError(); 3732 } else { 3733 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 3734 3735 if (FDecl) { 3736 // Check if we have too few/too many template arguments, based 3737 // on our knowledge of the function definition. 3738 const FunctionDecl *Def = 0; 3739 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 3740 const FunctionProtoType *Proto = 3741 Def->getType()->getAs<FunctionProtoType>(); 3742 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) { 3743 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 3744 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 3745 } 3746 } 3747 } 3748 3749 // Promote the arguments (C99 6.5.2.2p6). 3750 for (unsigned i = 0; i != NumArgs; i++) { 3751 Expr *Arg = Args[i]; 3752 DefaultArgumentPromotion(Arg); 3753 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 3754 Arg->getType(), 3755 PDiag(diag::err_call_incomplete_argument) 3756 << Arg->getSourceRange())) 3757 return ExprError(); 3758 TheCall->setArg(i, Arg); 3759 } 3760 } 3761 3762 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 3763 if (!Method->isStatic()) 3764 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 3765 << Fn->getSourceRange()); 3766 3767 // Check for sentinels 3768 if (NDecl) 3769 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 3770 3771 // Do special checking on direct calls to functions. 3772 if (FDecl) { 3773 if (CheckFunctionCall(FDecl, TheCall.get())) 3774 return ExprError(); 3775 3776 if (unsigned BuiltinID = FDecl->getBuiltinID()) 3777 return CheckBuiltinFunctionCall(BuiltinID, TheCall.take()); 3778 } else if (NDecl) { 3779 if (CheckBlockCall(NDecl, TheCall.get())) 3780 return ExprError(); 3781 } 3782 3783 return MaybeBindToTemporary(TheCall.take()); 3784} 3785 3786Action::OwningExprResult 3787Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, TypeTy *Ty, 3788 SourceLocation RParenLoc, ExprArg InitExpr) { 3789 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 3790 // FIXME: put back this assert when initializers are worked out. 3791 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 3792 3793 TypeSourceInfo *TInfo; 3794 QualType literalType = GetTypeFromParser(Ty, &TInfo); 3795 if (!TInfo) 3796 TInfo = Context.getTrivialTypeSourceInfo(literalType); 3797 3798 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, move(InitExpr)); 3799} 3800 3801Action::OwningExprResult 3802Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 3803 SourceLocation RParenLoc, ExprArg InitExpr) { 3804 QualType literalType = TInfo->getType(); 3805 Expr *literalExpr = static_cast<Expr*>(InitExpr.get()); 3806 3807 if (literalType->isArrayType()) { 3808 if (literalType->isVariableArrayType()) 3809 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 3810 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 3811 } else if (!literalType->isDependentType() && 3812 RequireCompleteType(LParenLoc, literalType, 3813 PDiag(diag::err_typecheck_decl_incomplete_type) 3814 << SourceRange(LParenLoc, 3815 literalExpr->getSourceRange().getEnd()))) 3816 return ExprError(); 3817 3818 InitializedEntity Entity 3819 = InitializedEntity::InitializeTemporary(literalType); 3820 InitializationKind Kind 3821 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 3822 /*IsCStyleCast=*/true); 3823 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 3824 OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, 3825 MultiExprArg(*this, (void**)&literalExpr, 1), 3826 &literalType); 3827 if (Result.isInvalid()) 3828 return ExprError(); 3829 InitExpr.release(); 3830 literalExpr = static_cast<Expr*>(Result.get()); 3831 3832 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 3833 if (isFileScope) { // 6.5.2.5p3 3834 if (CheckForConstantInitializer(literalExpr, literalType)) 3835 return ExprError(); 3836 } 3837 3838 Result.release(); 3839 3840 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 3841 literalExpr, isFileScope)); 3842} 3843 3844Action::OwningExprResult 3845Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 3846 SourceLocation RBraceLoc) { 3847 unsigned NumInit = initlist.size(); 3848 Expr **InitList = reinterpret_cast<Expr**>(initlist.release()); 3849 3850 // Semantic analysis for initializers is done by ActOnDeclarator() and 3851 // CheckInitializer() - it requires knowledge of the object being intialized. 3852 3853 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 3854 NumInit, RBraceLoc); 3855 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 3856 return Owned(E); 3857} 3858 3859static CastExpr::CastKind getScalarCastKind(ASTContext &Context, 3860 QualType SrcTy, QualType DestTy) { 3861 if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) 3862 return CastExpr::CK_NoOp; 3863 3864 if (SrcTy->hasPointerRepresentation()) { 3865 if (DestTy->hasPointerRepresentation()) 3866 return DestTy->isObjCObjectPointerType() ? 3867 CastExpr::CK_AnyPointerToObjCPointerCast : 3868 CastExpr::CK_BitCast; 3869 if (DestTy->isIntegerType()) 3870 return CastExpr::CK_PointerToIntegral; 3871 } 3872 3873 if (SrcTy->isIntegerType()) { 3874 if (DestTy->isIntegerType()) 3875 return CastExpr::CK_IntegralCast; 3876 if (DestTy->hasPointerRepresentation()) 3877 return CastExpr::CK_IntegralToPointer; 3878 if (DestTy->isRealFloatingType()) 3879 return CastExpr::CK_IntegralToFloating; 3880 } 3881 3882 if (SrcTy->isRealFloatingType()) { 3883 if (DestTy->isRealFloatingType()) 3884 return CastExpr::CK_FloatingCast; 3885 if (DestTy->isIntegerType()) 3886 return CastExpr::CK_FloatingToIntegral; 3887 } 3888 3889 // FIXME: Assert here. 3890 // assert(false && "Unhandled cast combination!"); 3891 return CastExpr::CK_Unknown; 3892} 3893 3894/// CheckCastTypes - Check type constraints for casting between types. 3895bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr, 3896 CastExpr::CastKind& Kind, 3897 CXXBaseSpecifierArray &BasePath, 3898 bool FunctionalStyle) { 3899 if (getLangOptions().CPlusPlus) 3900 return CXXCheckCStyleCast(TyR, castType, castExpr, Kind, BasePath, 3901 FunctionalStyle); 3902 3903 DefaultFunctionArrayLvalueConversion(castExpr); 3904 3905 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 3906 // type needs to be scalar. 3907 if (castType->isVoidType()) { 3908 // Cast to void allows any expr type. 3909 Kind = CastExpr::CK_ToVoid; 3910 return false; 3911 } 3912 3913 if (RequireCompleteType(TyR.getBegin(), castType, 3914 diag::err_typecheck_cast_to_incomplete)) 3915 return true; 3916 3917 if (!castType->isScalarType() && !castType->isVectorType()) { 3918 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 3919 (castType->isStructureType() || castType->isUnionType())) { 3920 // GCC struct/union extension: allow cast to self. 3921 // FIXME: Check that the cast destination type is complete. 3922 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 3923 << castType << castExpr->getSourceRange(); 3924 Kind = CastExpr::CK_NoOp; 3925 return false; 3926 } 3927 3928 if (castType->isUnionType()) { 3929 // GCC cast to union extension 3930 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 3931 RecordDecl::field_iterator Field, FieldEnd; 3932 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 3933 Field != FieldEnd; ++Field) { 3934 if (Context.hasSameUnqualifiedType(Field->getType(), 3935 castExpr->getType())) { 3936 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 3937 << castExpr->getSourceRange(); 3938 break; 3939 } 3940 } 3941 if (Field == FieldEnd) 3942 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 3943 << castExpr->getType() << castExpr->getSourceRange(); 3944 Kind = CastExpr::CK_ToUnion; 3945 return false; 3946 } 3947 3948 // Reject any other conversions to non-scalar types. 3949 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 3950 << castType << castExpr->getSourceRange(); 3951 } 3952 3953 if (!castExpr->getType()->isScalarType() && 3954 !castExpr->getType()->isVectorType()) { 3955 return Diag(castExpr->getLocStart(), 3956 diag::err_typecheck_expect_scalar_operand) 3957 << castExpr->getType() << castExpr->getSourceRange(); 3958 } 3959 3960 if (castType->isExtVectorType()) 3961 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 3962 3963 if (castType->isVectorType()) 3964 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 3965 if (castExpr->getType()->isVectorType()) 3966 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 3967 3968 if (isa<ObjCSelectorExpr>(castExpr)) 3969 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 3970 3971 if (!castType->isArithmeticType()) { 3972 QualType castExprType = castExpr->getType(); 3973 if (!castExprType->isIntegralType(Context) && 3974 castExprType->isArithmeticType()) 3975 return Diag(castExpr->getLocStart(), 3976 diag::err_cast_pointer_from_non_pointer_int) 3977 << castExprType << castExpr->getSourceRange(); 3978 } else if (!castExpr->getType()->isArithmeticType()) { 3979 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 3980 return Diag(castExpr->getLocStart(), 3981 diag::err_cast_pointer_to_non_pointer_int) 3982 << castType << castExpr->getSourceRange(); 3983 } 3984 3985 Kind = getScalarCastKind(Context, castExpr->getType(), castType); 3986 return false; 3987} 3988 3989bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 3990 CastExpr::CastKind &Kind) { 3991 assert(VectorTy->isVectorType() && "Not a vector type!"); 3992 3993 if (Ty->isVectorType() || Ty->isIntegerType()) { 3994 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 3995 return Diag(R.getBegin(), 3996 Ty->isVectorType() ? 3997 diag::err_invalid_conversion_between_vectors : 3998 diag::err_invalid_conversion_between_vector_and_integer) 3999 << VectorTy << Ty << R; 4000 } else 4001 return Diag(R.getBegin(), 4002 diag::err_invalid_conversion_between_vector_and_scalar) 4003 << VectorTy << Ty << R; 4004 4005 Kind = CastExpr::CK_BitCast; 4006 return false; 4007} 4008 4009bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4010 CastExpr::CastKind &Kind) { 4011 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4012 4013 QualType SrcTy = CastExpr->getType(); 4014 4015 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4016 // an ExtVectorType. 4017 if (SrcTy->isVectorType()) { 4018 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4019 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4020 << DestTy << SrcTy << R; 4021 Kind = CastExpr::CK_BitCast; 4022 return false; 4023 } 4024 4025 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4026 // conversion will take place first from scalar to elt type, and then 4027 // splat from elt type to vector. 4028 if (SrcTy->isPointerType()) 4029 return Diag(R.getBegin(), 4030 diag::err_invalid_conversion_between_vector_and_scalar) 4031 << DestTy << SrcTy << R; 4032 4033 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4034 ImpCastExprToType(CastExpr, DestElemTy, 4035 getScalarCastKind(Context, SrcTy, DestElemTy)); 4036 4037 Kind = CastExpr::CK_VectorSplat; 4038 return false; 4039} 4040 4041Action::OwningExprResult 4042Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, TypeTy *Ty, 4043 SourceLocation RParenLoc, ExprArg Op) { 4044 assert((Ty != 0) && (Op.get() != 0) && 4045 "ActOnCastExpr(): missing type or expr"); 4046 4047 TypeSourceInfo *castTInfo; 4048 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4049 if (!castTInfo) 4050 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4051 4052 // If the Expr being casted is a ParenListExpr, handle it specially. 4053 Expr *castExpr = (Expr *)Op.get(); 4054 if (isa<ParenListExpr>(castExpr)) 4055 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, move(Op), 4056 castTInfo); 4057 4058 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, move(Op)); 4059} 4060 4061Action::OwningExprResult 4062Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4063 SourceLocation RParenLoc, ExprArg Op) { 4064 Expr *castExpr = static_cast<Expr*>(Op.get()); 4065 4066 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 4067 CXXBaseSpecifierArray BasePath; 4068 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4069 Kind, BasePath)) 4070 return ExprError(); 4071 4072 Op.release(); 4073 return Owned(new (Context) CStyleCastExpr( 4074 Ty->getType().getNonLValueExprType(Context), 4075 Kind, castExpr, BasePath, Ty, 4076 LParenLoc, RParenLoc)); 4077} 4078 4079/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4080/// of comma binary operators. 4081Action::OwningExprResult 4082Sema::MaybeConvertParenListExprToParenExpr(Scope *S, ExprArg EA) { 4083 Expr *expr = EA.takeAs<Expr>(); 4084 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4085 if (!E) 4086 return Owned(expr); 4087 4088 OwningExprResult Result(*this, E->getExpr(0)); 4089 4090 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4091 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, move(Result), 4092 Owned(E->getExpr(i))); 4093 4094 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), move(Result)); 4095} 4096 4097Action::OwningExprResult 4098Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4099 SourceLocation RParenLoc, ExprArg Op, 4100 TypeSourceInfo *TInfo) { 4101 ParenListExpr *PE = (ParenListExpr *)Op.get(); 4102 QualType Ty = TInfo->getType(); 4103 bool isAltiVecLiteral = false; 4104 4105 // Check for an altivec literal, 4106 // i.e. all the elements are integer constants. 4107 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4108 if (PE->getNumExprs() == 0) { 4109 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4110 return ExprError(); 4111 } 4112 if (PE->getNumExprs() == 1) { 4113 if (!PE->getExpr(0)->getType()->isVectorType()) 4114 isAltiVecLiteral = true; 4115 } 4116 else 4117 isAltiVecLiteral = true; 4118 } 4119 4120 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4121 // then handle it as such. 4122 if (isAltiVecLiteral) { 4123 llvm::SmallVector<Expr *, 8> initExprs; 4124 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4125 initExprs.push_back(PE->getExpr(i)); 4126 4127 // FIXME: This means that pretty-printing the final AST will produce curly 4128 // braces instead of the original commas. 4129 Op.release(); 4130 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4131 &initExprs[0], 4132 initExprs.size(), RParenLoc); 4133 E->setType(Ty); 4134 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, Owned(E)); 4135 } else { 4136 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4137 // sequence of BinOp comma operators. 4138 Op = MaybeConvertParenListExprToParenExpr(S, move(Op)); 4139 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, move(Op)); 4140 } 4141} 4142 4143Action::OwningExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4144 SourceLocation R, 4145 MultiExprArg Val, 4146 TypeTy *TypeOfCast) { 4147 unsigned nexprs = Val.size(); 4148 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4149 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4150 Expr *expr; 4151 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4152 expr = new (Context) ParenExpr(L, R, exprs[0]); 4153 else 4154 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4155 return Owned(expr); 4156} 4157 4158/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4159/// In that case, lhs = cond. 4160/// C99 6.5.15 4161QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4162 SourceLocation QuestionLoc) { 4163 // C++ is sufficiently different to merit its own checker. 4164 if (getLangOptions().CPlusPlus) 4165 return CXXCheckConditionalOperands(Cond, LHS, RHS, QuestionLoc); 4166 4167 UsualUnaryConversions(Cond); 4168 UsualUnaryConversions(LHS); 4169 UsualUnaryConversions(RHS); 4170 QualType CondTy = Cond->getType(); 4171 QualType LHSTy = LHS->getType(); 4172 QualType RHSTy = RHS->getType(); 4173 4174 // first, check the condition. 4175 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4176 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4177 << CondTy; 4178 return QualType(); 4179 } 4180 4181 // Now check the two expressions. 4182 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4183 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4184 4185 // If both operands have arithmetic type, do the usual arithmetic conversions 4186 // to find a common type: C99 6.5.15p3,5. 4187 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 4188 UsualArithmeticConversions(LHS, RHS); 4189 return LHS->getType(); 4190 } 4191 4192 // If both operands are the same structure or union type, the result is that 4193 // type. 4194 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 4195 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 4196 if (LHSRT->getDecl() == RHSRT->getDecl()) 4197 // "If both the operands have structure or union type, the result has 4198 // that type." This implies that CV qualifiers are dropped. 4199 return LHSTy.getUnqualifiedType(); 4200 // FIXME: Type of conditional expression must be complete in C mode. 4201 } 4202 4203 // C99 6.5.15p5: "If both operands have void type, the result has void type." 4204 // The following || allows only one side to be void (a GCC-ism). 4205 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 4206 if (!LHSTy->isVoidType()) 4207 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4208 << RHS->getSourceRange(); 4209 if (!RHSTy->isVoidType()) 4210 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 4211 << LHS->getSourceRange(); 4212 ImpCastExprToType(LHS, Context.VoidTy, CastExpr::CK_ToVoid); 4213 ImpCastExprToType(RHS, Context.VoidTy, CastExpr::CK_ToVoid); 4214 return Context.VoidTy; 4215 } 4216 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 4217 // the type of the other operand." 4218 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 4219 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4220 // promote the null to a pointer. 4221 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_Unknown); 4222 return LHSTy; 4223 } 4224 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 4225 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4226 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_Unknown); 4227 return RHSTy; 4228 } 4229 4230 // All objective-c pointer type analysis is done here. 4231 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 4232 QuestionLoc); 4233 if (!compositeType.isNull()) 4234 return compositeType; 4235 4236 4237 // Handle block pointer types. 4238 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 4239 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 4240 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 4241 QualType destType = Context.getPointerType(Context.VoidTy); 4242 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4243 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4244 return destType; 4245 } 4246 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4247 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4248 return QualType(); 4249 } 4250 // We have 2 block pointer types. 4251 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4252 // Two identical block pointer types are always compatible. 4253 return LHSTy; 4254 } 4255 // The block pointer types aren't identical, continue checking. 4256 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 4257 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 4258 4259 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4260 rhptee.getUnqualifiedType())) { 4261 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4262 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4263 // In this situation, we assume void* type. No especially good 4264 // reason, but this is what gcc does, and we do have to pick 4265 // to get a consistent AST. 4266 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4267 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4268 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4269 return incompatTy; 4270 } 4271 // The block pointer types are compatible. 4272 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4273 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4274 return LHSTy; 4275 } 4276 4277 // Check constraints for C object pointers types (C99 6.5.15p3,6). 4278 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 4279 // get the "pointed to" types 4280 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4281 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4282 4283 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 4284 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 4285 // Figure out necessary qualifiers (C99 6.5.15p6) 4286 QualType destPointee 4287 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4288 QualType destType = Context.getPointerType(destPointee); 4289 // Add qualifiers if necessary. 4290 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4291 // Promote to void*. 4292 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4293 return destType; 4294 } 4295 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 4296 QualType destPointee 4297 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4298 QualType destType = Context.getPointerType(destPointee); 4299 // Add qualifiers if necessary. 4300 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4301 // Promote to void*. 4302 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4303 return destType; 4304 } 4305 4306 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4307 // Two identical pointer types are always compatible. 4308 return LHSTy; 4309 } 4310 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 4311 rhptee.getUnqualifiedType())) { 4312 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 4313 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4314 // In this situation, we assume void* type. No especially good 4315 // reason, but this is what gcc does, and we do have to pick 4316 // to get a consistent AST. 4317 QualType incompatTy = Context.getPointerType(Context.VoidTy); 4318 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4319 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4320 return incompatTy; 4321 } 4322 // The pointer types are compatible. 4323 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 4324 // differently qualified versions of compatible types, the result type is 4325 // a pointer to an appropriately qualified version of the *composite* 4326 // type. 4327 // FIXME: Need to calculate the composite type. 4328 // FIXME: Need to add qualifiers 4329 ImpCastExprToType(LHS, LHSTy, CastExpr::CK_BitCast); 4330 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4331 return LHSTy; 4332 } 4333 4334 // GCC compatibility: soften pointer/integer mismatch. 4335 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 4336 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4337 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4338 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_IntegralToPointer); 4339 return RHSTy; 4340 } 4341 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 4342 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 4343 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4344 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_IntegralToPointer); 4345 return LHSTy; 4346 } 4347 4348 // Otherwise, the operands are not compatible. 4349 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4350 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 4351 return QualType(); 4352} 4353 4354/// FindCompositeObjCPointerType - Helper method to find composite type of 4355/// two objective-c pointer types of the two input expressions. 4356QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 4357 SourceLocation QuestionLoc) { 4358 QualType LHSTy = LHS->getType(); 4359 QualType RHSTy = RHS->getType(); 4360 4361 // Handle things like Class and struct objc_class*. Here we case the result 4362 // to the pseudo-builtin, because that will be implicitly cast back to the 4363 // redefinition type if an attempt is made to access its fields. 4364 if (LHSTy->isObjCClassType() && 4365 (RHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4366 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4367 return LHSTy; 4368 } 4369 if (RHSTy->isObjCClassType() && 4370 (LHSTy.getDesugaredType() == Context.ObjCClassRedefinitionType)) { 4371 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4372 return RHSTy; 4373 } 4374 // And the same for struct objc_object* / id 4375 if (LHSTy->isObjCIdType() && 4376 (RHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4377 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4378 return LHSTy; 4379 } 4380 if (RHSTy->isObjCIdType() && 4381 (LHSTy.getDesugaredType() == Context.ObjCIdRedefinitionType)) { 4382 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4383 return RHSTy; 4384 } 4385 // And the same for struct objc_selector* / SEL 4386 if (Context.isObjCSelType(LHSTy) && 4387 (RHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4388 ImpCastExprToType(RHS, LHSTy, CastExpr::CK_BitCast); 4389 return LHSTy; 4390 } 4391 if (Context.isObjCSelType(RHSTy) && 4392 (LHSTy.getDesugaredType() == Context.ObjCSelRedefinitionType)) { 4393 ImpCastExprToType(LHS, RHSTy, CastExpr::CK_BitCast); 4394 return RHSTy; 4395 } 4396 // Check constraints for Objective-C object pointers types. 4397 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 4398 4399 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 4400 // Two identical object pointer types are always compatible. 4401 return LHSTy; 4402 } 4403 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 4404 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 4405 QualType compositeType = LHSTy; 4406 4407 // If both operands are interfaces and either operand can be 4408 // assigned to the other, use that type as the composite 4409 // type. This allows 4410 // xxx ? (A*) a : (B*) b 4411 // where B is a subclass of A. 4412 // 4413 // Additionally, as for assignment, if either type is 'id' 4414 // allow silent coercion. Finally, if the types are 4415 // incompatible then make sure to use 'id' as the composite 4416 // type so the result is acceptable for sending messages to. 4417 4418 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 4419 // It could return the composite type. 4420 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 4421 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 4422 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 4423 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 4424 } else if ((LHSTy->isObjCQualifiedIdType() || 4425 RHSTy->isObjCQualifiedIdType()) && 4426 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 4427 // Need to handle "id<xx>" explicitly. 4428 // GCC allows qualified id and any Objective-C type to devolve to 4429 // id. Currently localizing to here until clear this should be 4430 // part of ObjCQualifiedIdTypesAreCompatible. 4431 compositeType = Context.getObjCIdType(); 4432 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 4433 compositeType = Context.getObjCIdType(); 4434 } else if (!(compositeType = 4435 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 4436 ; 4437 else { 4438 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 4439 << LHSTy << RHSTy 4440 << LHS->getSourceRange() << RHS->getSourceRange(); 4441 QualType incompatTy = Context.getObjCIdType(); 4442 ImpCastExprToType(LHS, incompatTy, CastExpr::CK_BitCast); 4443 ImpCastExprToType(RHS, incompatTy, CastExpr::CK_BitCast); 4444 return incompatTy; 4445 } 4446 // The object pointer types are compatible. 4447 ImpCastExprToType(LHS, compositeType, CastExpr::CK_BitCast); 4448 ImpCastExprToType(RHS, compositeType, CastExpr::CK_BitCast); 4449 return compositeType; 4450 } 4451 // Check Objective-C object pointer types and 'void *' 4452 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 4453 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 4454 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4455 QualType destPointee 4456 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 4457 QualType destType = Context.getPointerType(destPointee); 4458 // Add qualifiers if necessary. 4459 ImpCastExprToType(LHS, destType, CastExpr::CK_NoOp); 4460 // Promote to void*. 4461 ImpCastExprToType(RHS, destType, CastExpr::CK_BitCast); 4462 return destType; 4463 } 4464 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 4465 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 4466 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 4467 QualType destPointee 4468 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 4469 QualType destType = Context.getPointerType(destPointee); 4470 // Add qualifiers if necessary. 4471 ImpCastExprToType(RHS, destType, CastExpr::CK_NoOp); 4472 // Promote to void*. 4473 ImpCastExprToType(LHS, destType, CastExpr::CK_BitCast); 4474 return destType; 4475 } 4476 return QualType(); 4477} 4478 4479/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 4480/// in the case of a the GNU conditional expr extension. 4481Action::OwningExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 4482 SourceLocation ColonLoc, 4483 ExprArg Cond, ExprArg LHS, 4484 ExprArg RHS) { 4485 Expr *CondExpr = (Expr *) Cond.get(); 4486 Expr *LHSExpr = (Expr *) LHS.get(), *RHSExpr = (Expr *) RHS.get(); 4487 4488 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 4489 // was the condition. 4490 bool isLHSNull = LHSExpr == 0; 4491 if (isLHSNull) 4492 LHSExpr = CondExpr; 4493 4494 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, 4495 RHSExpr, QuestionLoc); 4496 if (result.isNull()) 4497 return ExprError(); 4498 4499 Cond.release(); 4500 LHS.release(); 4501 RHS.release(); 4502 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 4503 isLHSNull ? 0 : LHSExpr, 4504 ColonLoc, RHSExpr, result)); 4505} 4506 4507// CheckPointerTypesForAssignment - This is a very tricky routine (despite 4508// being closely modeled after the C99 spec:-). The odd characteristic of this 4509// routine is it effectively iqnores the qualifiers on the top level pointee. 4510// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 4511// FIXME: add a couple examples in this comment. 4512Sema::AssignConvertType 4513Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4514 QualType lhptee, rhptee; 4515 4516 if ((lhsType->isObjCClassType() && 4517 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4518 (rhsType->isObjCClassType() && 4519 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4520 return Compatible; 4521 } 4522 4523 // get the "pointed to" type (ignoring qualifiers at the top level) 4524 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 4525 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 4526 4527 // make sure we operate on the canonical type 4528 lhptee = Context.getCanonicalType(lhptee); 4529 rhptee = Context.getCanonicalType(rhptee); 4530 4531 AssignConvertType ConvTy = Compatible; 4532 4533 // C99 6.5.16.1p1: This following citation is common to constraints 4534 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 4535 // qualifiers of the type *pointed to* by the right; 4536 // FIXME: Handle ExtQualType 4537 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4538 ConvTy = CompatiblePointerDiscardsQualifiers; 4539 4540 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 4541 // incomplete type and the other is a pointer to a qualified or unqualified 4542 // version of void... 4543 if (lhptee->isVoidType()) { 4544 if (rhptee->isIncompleteOrObjectType()) 4545 return ConvTy; 4546 4547 // As an extension, we allow cast to/from void* to function pointer. 4548 assert(rhptee->isFunctionType()); 4549 return FunctionVoidPointer; 4550 } 4551 4552 if (rhptee->isVoidType()) { 4553 if (lhptee->isIncompleteOrObjectType()) 4554 return ConvTy; 4555 4556 // As an extension, we allow cast to/from void* to function pointer. 4557 assert(lhptee->isFunctionType()); 4558 return FunctionVoidPointer; 4559 } 4560 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 4561 // unqualified versions of compatible types, ... 4562 lhptee = lhptee.getUnqualifiedType(); 4563 rhptee = rhptee.getUnqualifiedType(); 4564 if (!Context.typesAreCompatible(lhptee, rhptee)) { 4565 // Check if the pointee types are compatible ignoring the sign. 4566 // We explicitly check for char so that we catch "char" vs 4567 // "unsigned char" on systems where "char" is unsigned. 4568 if (lhptee->isCharType()) 4569 lhptee = Context.UnsignedCharTy; 4570 else if (lhptee->hasSignedIntegerRepresentation()) 4571 lhptee = Context.getCorrespondingUnsignedType(lhptee); 4572 4573 if (rhptee->isCharType()) 4574 rhptee = Context.UnsignedCharTy; 4575 else if (rhptee->hasSignedIntegerRepresentation()) 4576 rhptee = Context.getCorrespondingUnsignedType(rhptee); 4577 4578 if (lhptee == rhptee) { 4579 // Types are compatible ignoring the sign. Qualifier incompatibility 4580 // takes priority over sign incompatibility because the sign 4581 // warning can be disabled. 4582 if (ConvTy != Compatible) 4583 return ConvTy; 4584 return IncompatiblePointerSign; 4585 } 4586 4587 // If we are a multi-level pointer, it's possible that our issue is simply 4588 // one of qualification - e.g. char ** -> const char ** is not allowed. If 4589 // the eventual target type is the same and the pointers have the same 4590 // level of indirection, this must be the issue. 4591 if (lhptee->isPointerType() && rhptee->isPointerType()) { 4592 do { 4593 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 4594 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 4595 4596 lhptee = Context.getCanonicalType(lhptee); 4597 rhptee = Context.getCanonicalType(rhptee); 4598 } while (lhptee->isPointerType() && rhptee->isPointerType()); 4599 4600 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 4601 return IncompatibleNestedPointerQualifiers; 4602 } 4603 4604 // General pointer incompatibility takes priority over qualifiers. 4605 return IncompatiblePointer; 4606 } 4607 return ConvTy; 4608} 4609 4610/// CheckBlockPointerTypesForAssignment - This routine determines whether two 4611/// block pointer types are compatible or whether a block and normal pointer 4612/// are compatible. It is more restrict than comparing two function pointer 4613// types. 4614Sema::AssignConvertType 4615Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 4616 QualType rhsType) { 4617 QualType lhptee, rhptee; 4618 4619 // get the "pointed to" type (ignoring qualifiers at the top level) 4620 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 4621 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 4622 4623 // make sure we operate on the canonical type 4624 lhptee = Context.getCanonicalType(lhptee); 4625 rhptee = Context.getCanonicalType(rhptee); 4626 4627 AssignConvertType ConvTy = Compatible; 4628 4629 // For blocks we enforce that qualifiers are identical. 4630 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 4631 ConvTy = CompatiblePointerDiscardsQualifiers; 4632 4633 if (!getLangOptions().CPlusPlus) { 4634 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 4635 return IncompatibleBlockPointer; 4636 } 4637 else if (!Context.typesAreCompatible(lhptee, rhptee)) 4638 return IncompatibleBlockPointer; 4639 return ConvTy; 4640} 4641 4642/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 4643/// for assignment compatibility. 4644Sema::AssignConvertType 4645Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 4646 if (lhsType->isObjCBuiltinType()) { 4647 // Class is not compatible with ObjC object pointers. 4648 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 4649 !rhsType->isObjCQualifiedClassType()) 4650 return IncompatiblePointer; 4651 return Compatible; 4652 } 4653 if (rhsType->isObjCBuiltinType()) { 4654 // Class is not compatible with ObjC object pointers. 4655 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 4656 !lhsType->isObjCQualifiedClassType()) 4657 return IncompatiblePointer; 4658 return Compatible; 4659 } 4660 QualType lhptee = 4661 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4662 QualType rhptee = 4663 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 4664 // make sure we operate on the canonical type 4665 lhptee = Context.getCanonicalType(lhptee); 4666 rhptee = Context.getCanonicalType(rhptee); 4667 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 4668 return CompatiblePointerDiscardsQualifiers; 4669 4670 if (Context.typesAreCompatible(lhsType, rhsType)) 4671 return Compatible; 4672 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 4673 return IncompatibleObjCQualifiedId; 4674 return IncompatiblePointer; 4675} 4676 4677/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 4678/// has code to accommodate several GCC extensions when type checking 4679/// pointers. Here are some objectionable examples that GCC considers warnings: 4680/// 4681/// int a, *pint; 4682/// short *pshort; 4683/// struct foo *pfoo; 4684/// 4685/// pint = pshort; // warning: assignment from incompatible pointer type 4686/// a = pint; // warning: assignment makes integer from pointer without a cast 4687/// pint = a; // warning: assignment makes pointer from integer without a cast 4688/// pint = pfoo; // warning: assignment from incompatible pointer type 4689/// 4690/// As a result, the code for dealing with pointers is more complex than the 4691/// C99 spec dictates. 4692/// 4693Sema::AssignConvertType 4694Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 4695 // Get canonical types. We're not formatting these types, just comparing 4696 // them. 4697 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 4698 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 4699 4700 if (lhsType == rhsType) 4701 return Compatible; // Common case: fast path an exact match. 4702 4703 if ((lhsType->isObjCClassType() && 4704 (rhsType.getDesugaredType() == Context.ObjCClassRedefinitionType)) || 4705 (rhsType->isObjCClassType() && 4706 (lhsType.getDesugaredType() == Context.ObjCClassRedefinitionType))) { 4707 return Compatible; 4708 } 4709 4710 // If the left-hand side is a reference type, then we are in a 4711 // (rare!) case where we've allowed the use of references in C, 4712 // e.g., as a parameter type in a built-in function. In this case, 4713 // just make sure that the type referenced is compatible with the 4714 // right-hand side type. The caller is responsible for adjusting 4715 // lhsType so that the resulting expression does not have reference 4716 // type. 4717 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 4718 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) 4719 return Compatible; 4720 return Incompatible; 4721 } 4722 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 4723 // to the same ExtVector type. 4724 if (lhsType->isExtVectorType()) { 4725 if (rhsType->isExtVectorType()) 4726 return lhsType == rhsType ? Compatible : Incompatible; 4727 if (rhsType->isArithmeticType()) 4728 return Compatible; 4729 } 4730 4731 if (lhsType->isVectorType() || rhsType->isVectorType()) { 4732 if (lhsType->isVectorType() && rhsType->isVectorType()) { 4733 // If we are allowing lax vector conversions, and LHS and RHS are both 4734 // vectors, the total size only needs to be the same. This is a bitcast; 4735 // no bits are changed but the result type is different. 4736 if (getLangOptions().LaxVectorConversions && 4737 (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) 4738 return IncompatibleVectors; 4739 4740 // Allow assignments of an AltiVec vector type to an equivalent GCC 4741 // vector type and vice versa 4742 if (Context.areCompatibleVectorTypes(lhsType, rhsType)) 4743 return Compatible; 4744 } 4745 return Incompatible; 4746 } 4747 4748 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 4749 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) 4750 return Compatible; 4751 4752 if (isa<PointerType>(lhsType)) { 4753 if (rhsType->isIntegerType()) 4754 return IntToPointer; 4755 4756 if (isa<PointerType>(rhsType)) 4757 return CheckPointerTypesForAssignment(lhsType, rhsType); 4758 4759 // In general, C pointers are not compatible with ObjC object pointers. 4760 if (isa<ObjCObjectPointerType>(rhsType)) { 4761 if (lhsType->isVoidPointerType()) // an exception to the rule. 4762 return Compatible; 4763 return IncompatiblePointer; 4764 } 4765 if (rhsType->getAs<BlockPointerType>()) { 4766 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4767 return Compatible; 4768 4769 // Treat block pointers as objects. 4770 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) 4771 return Compatible; 4772 } 4773 return Incompatible; 4774 } 4775 4776 if (isa<BlockPointerType>(lhsType)) { 4777 if (rhsType->isIntegerType()) 4778 return IntToBlockPointer; 4779 4780 // Treat block pointers as objects. 4781 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 4782 return Compatible; 4783 4784 if (rhsType->isBlockPointerType()) 4785 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 4786 4787 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4788 if (RHSPT->getPointeeType()->isVoidType()) 4789 return Compatible; 4790 } 4791 return Incompatible; 4792 } 4793 4794 if (isa<ObjCObjectPointerType>(lhsType)) { 4795 if (rhsType->isIntegerType()) 4796 return IntToPointer; 4797 4798 // In general, C pointers are not compatible with ObjC object pointers. 4799 if (isa<PointerType>(rhsType)) { 4800 if (rhsType->isVoidPointerType()) // an exception to the rule. 4801 return Compatible; 4802 return IncompatiblePointer; 4803 } 4804 if (rhsType->isObjCObjectPointerType()) { 4805 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 4806 } 4807 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 4808 if (RHSPT->getPointeeType()->isVoidType()) 4809 return Compatible; 4810 } 4811 // Treat block pointers as objects. 4812 if (rhsType->isBlockPointerType()) 4813 return Compatible; 4814 return Incompatible; 4815 } 4816 if (isa<PointerType>(rhsType)) { 4817 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4818 if (lhsType == Context.BoolTy) 4819 return Compatible; 4820 4821 if (lhsType->isIntegerType()) 4822 return PointerToInt; 4823 4824 if (isa<PointerType>(lhsType)) 4825 return CheckPointerTypesForAssignment(lhsType, rhsType); 4826 4827 if (isa<BlockPointerType>(lhsType) && 4828 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4829 return Compatible; 4830 return Incompatible; 4831 } 4832 if (isa<ObjCObjectPointerType>(rhsType)) { 4833 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 4834 if (lhsType == Context.BoolTy) 4835 return Compatible; 4836 4837 if (lhsType->isIntegerType()) 4838 return PointerToInt; 4839 4840 // In general, C pointers are not compatible with ObjC object pointers. 4841 if (isa<PointerType>(lhsType)) { 4842 if (lhsType->isVoidPointerType()) // an exception to the rule. 4843 return Compatible; 4844 return IncompatiblePointer; 4845 } 4846 if (isa<BlockPointerType>(lhsType) && 4847 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) 4848 return Compatible; 4849 return Incompatible; 4850 } 4851 4852 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 4853 if (Context.typesAreCompatible(lhsType, rhsType)) 4854 return Compatible; 4855 } 4856 return Incompatible; 4857} 4858 4859/// \brief Constructs a transparent union from an expression that is 4860/// used to initialize the transparent union. 4861static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 4862 QualType UnionType, FieldDecl *Field) { 4863 // Build an initializer list that designates the appropriate member 4864 // of the transparent union. 4865 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 4866 &E, 1, 4867 SourceLocation()); 4868 Initializer->setType(UnionType); 4869 Initializer->setInitializedFieldInUnion(Field); 4870 4871 // Build a compound literal constructing a value of the transparent 4872 // union type from this initializer list. 4873 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 4874 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 4875 Initializer, false); 4876} 4877 4878Sema::AssignConvertType 4879Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 4880 QualType FromType = rExpr->getType(); 4881 4882 // If the ArgType is a Union type, we want to handle a potential 4883 // transparent_union GCC extension. 4884 const RecordType *UT = ArgType->getAsUnionType(); 4885 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 4886 return Incompatible; 4887 4888 // The field to initialize within the transparent union. 4889 RecordDecl *UD = UT->getDecl(); 4890 FieldDecl *InitField = 0; 4891 // It's compatible if the expression matches any of the fields. 4892 for (RecordDecl::field_iterator it = UD->field_begin(), 4893 itend = UD->field_end(); 4894 it != itend; ++it) { 4895 if (it->getType()->isPointerType()) { 4896 // If the transparent union contains a pointer type, we allow: 4897 // 1) void pointer 4898 // 2) null pointer constant 4899 if (FromType->isPointerType()) 4900 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 4901 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_BitCast); 4902 InitField = *it; 4903 break; 4904 } 4905 4906 if (rExpr->isNullPointerConstant(Context, 4907 Expr::NPC_ValueDependentIsNull)) { 4908 ImpCastExprToType(rExpr, it->getType(), CastExpr::CK_IntegralToPointer); 4909 InitField = *it; 4910 break; 4911 } 4912 } 4913 4914 if (CheckAssignmentConstraints(it->getType(), rExpr->getType()) 4915 == Compatible) { 4916 InitField = *it; 4917 break; 4918 } 4919 } 4920 4921 if (!InitField) 4922 return Incompatible; 4923 4924 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 4925 return Compatible; 4926} 4927 4928Sema::AssignConvertType 4929Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 4930 if (getLangOptions().CPlusPlus) { 4931 if (!lhsType->isRecordType()) { 4932 // C++ 5.17p3: If the left operand is not of class type, the 4933 // expression is implicitly converted (C++ 4) to the 4934 // cv-unqualified type of the left operand. 4935 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 4936 AA_Assigning)) 4937 return Incompatible; 4938 return Compatible; 4939 } 4940 4941 // FIXME: Currently, we fall through and treat C++ classes like C 4942 // structures. 4943 } 4944 4945 // C99 6.5.16.1p1: the left operand is a pointer and the right is 4946 // a null pointer constant. 4947 if ((lhsType->isPointerType() || 4948 lhsType->isObjCObjectPointerType() || 4949 lhsType->isBlockPointerType()) 4950 && rExpr->isNullPointerConstant(Context, 4951 Expr::NPC_ValueDependentIsNull)) { 4952 ImpCastExprToType(rExpr, lhsType, CastExpr::CK_Unknown); 4953 return Compatible; 4954 } 4955 4956 // This check seems unnatural, however it is necessary to ensure the proper 4957 // conversion of functions/arrays. If the conversion were done for all 4958 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 4959 // expressions that suppress this implicit conversion (&, sizeof). 4960 // 4961 // Suppress this for references: C++ 8.5.3p5. 4962 if (!lhsType->isReferenceType()) 4963 DefaultFunctionArrayLvalueConversion(rExpr); 4964 4965 Sema::AssignConvertType result = 4966 CheckAssignmentConstraints(lhsType, rExpr->getType()); 4967 4968 // C99 6.5.16.1p2: The value of the right operand is converted to the 4969 // type of the assignment expression. 4970 // CheckAssignmentConstraints allows the left-hand side to be a reference, 4971 // so that we can use references in built-in functions even in C. 4972 // The getNonReferenceType() call makes sure that the resulting expression 4973 // does not have reference type. 4974 if (result != Incompatible && rExpr->getType() != lhsType) 4975 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), 4976 CastExpr::CK_Unknown); 4977 return result; 4978} 4979 4980QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4981 Diag(Loc, diag::err_typecheck_invalid_operands) 4982 << lex->getType() << rex->getType() 4983 << lex->getSourceRange() << rex->getSourceRange(); 4984 return QualType(); 4985} 4986 4987QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 4988 // For conversion purposes, we ignore any qualifiers. 4989 // For example, "const float" and "float" are equivalent. 4990 QualType lhsType = 4991 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 4992 QualType rhsType = 4993 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 4994 4995 // If the vector types are identical, return. 4996 if (lhsType == rhsType) 4997 return lhsType; 4998 4999 // Handle the case of a vector & extvector type of the same size and element 5000 // type. It would be nice if we only had one vector type someday. 5001 if (getLangOptions().LaxVectorConversions) { 5002 // FIXME: Should we warn here? 5003 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5004 if (const VectorType *RV = rhsType->getAs<VectorType>()) 5005 if (LV->getElementType() == RV->getElementType() && 5006 LV->getNumElements() == RV->getNumElements()) { 5007 if (lhsType->isExtVectorType()) { 5008 ImpCastExprToType(rex, lhsType, CastExpr::CK_BitCast); 5009 return lhsType; 5010 } 5011 5012 ImpCastExprToType(lex, rhsType, CastExpr::CK_BitCast); 5013 return rhsType; 5014 } 5015 } 5016 } 5017 5018 // Handle the case of equivalent AltiVec and GCC vector types 5019 if (lhsType->isVectorType() && rhsType->isVectorType() && 5020 Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5021 ImpCastExprToType(lex, rhsType, CastExpr::CK_BitCast); 5022 return rhsType; 5023 } 5024 5025 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5026 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5027 bool swapped = false; 5028 if (rhsType->isExtVectorType()) { 5029 swapped = true; 5030 std::swap(rex, lex); 5031 std::swap(rhsType, lhsType); 5032 } 5033 5034 // Handle the case of an ext vector and scalar. 5035 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5036 QualType EltTy = LV->getElementType(); 5037 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5038 if (Context.getIntegerTypeOrder(EltTy, rhsType) >= 0) { 5039 ImpCastExprToType(rex, lhsType, CastExpr::CK_IntegralCast); 5040 if (swapped) std::swap(rex, lex); 5041 return lhsType; 5042 } 5043 } 5044 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5045 rhsType->isRealFloatingType()) { 5046 if (Context.getFloatingTypeOrder(EltTy, rhsType) >= 0) { 5047 ImpCastExprToType(rex, lhsType, CastExpr::CK_FloatingCast); 5048 if (swapped) std::swap(rex, lex); 5049 return lhsType; 5050 } 5051 } 5052 } 5053 5054 // Vectors of different size or scalar and non-ext-vector are errors. 5055 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5056 << lex->getType() << rex->getType() 5057 << lex->getSourceRange() << rex->getSourceRange(); 5058 return QualType(); 5059} 5060 5061QualType Sema::CheckMultiplyDivideOperands( 5062 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5063 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5064 return CheckVectorOperands(Loc, lex, rex); 5065 5066 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5067 5068 if (!lex->getType()->isArithmeticType() || 5069 !rex->getType()->isArithmeticType()) 5070 return InvalidOperands(Loc, lex, rex); 5071 5072 // Check for division by zero. 5073 if (isDiv && 5074 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5075 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5076 << rex->getSourceRange()); 5077 5078 return compType; 5079} 5080 5081QualType Sema::CheckRemainderOperands( 5082 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5083 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5084 if (lex->getType()->hasIntegerRepresentation() && 5085 rex->getType()->hasIntegerRepresentation()) 5086 return CheckVectorOperands(Loc, lex, rex); 5087 return InvalidOperands(Loc, lex, rex); 5088 } 5089 5090 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5091 5092 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 5093 return InvalidOperands(Loc, lex, rex); 5094 5095 // Check for remainder by zero. 5096 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5097 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 5098 << rex->getSourceRange()); 5099 5100 return compType; 5101} 5102 5103QualType Sema::CheckAdditionOperands( // C99 6.5.6 5104 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 5105 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5106 QualType compType = CheckVectorOperands(Loc, lex, rex); 5107 if (CompLHSTy) *CompLHSTy = compType; 5108 return compType; 5109 } 5110 5111 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5112 5113 // handle the common case first (both operands are arithmetic). 5114 if (lex->getType()->isArithmeticType() && 5115 rex->getType()->isArithmeticType()) { 5116 if (CompLHSTy) *CompLHSTy = compType; 5117 return compType; 5118 } 5119 5120 // Put any potential pointer into PExp 5121 Expr* PExp = lex, *IExp = rex; 5122 if (IExp->getType()->isAnyPointerType()) 5123 std::swap(PExp, IExp); 5124 5125 if (PExp->getType()->isAnyPointerType()) { 5126 5127 if (IExp->getType()->isIntegerType()) { 5128 QualType PointeeTy = PExp->getType()->getPointeeType(); 5129 5130 // Check for arithmetic on pointers to incomplete types. 5131 if (PointeeTy->isVoidType()) { 5132 if (getLangOptions().CPlusPlus) { 5133 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5134 << lex->getSourceRange() << rex->getSourceRange(); 5135 return QualType(); 5136 } 5137 5138 // GNU extension: arithmetic on pointer to void 5139 Diag(Loc, diag::ext_gnu_void_ptr) 5140 << lex->getSourceRange() << rex->getSourceRange(); 5141 } else if (PointeeTy->isFunctionType()) { 5142 if (getLangOptions().CPlusPlus) { 5143 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5144 << lex->getType() << lex->getSourceRange(); 5145 return QualType(); 5146 } 5147 5148 // GNU extension: arithmetic on pointer to function 5149 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5150 << lex->getType() << lex->getSourceRange(); 5151 } else { 5152 // Check if we require a complete type. 5153 if (((PExp->getType()->isPointerType() && 5154 !PExp->getType()->isDependentType()) || 5155 PExp->getType()->isObjCObjectPointerType()) && 5156 RequireCompleteType(Loc, PointeeTy, 5157 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 5158 << PExp->getSourceRange() 5159 << PExp->getType())) 5160 return QualType(); 5161 } 5162 // Diagnose bad cases where we step over interface counts. 5163 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5164 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5165 << PointeeTy << PExp->getSourceRange(); 5166 return QualType(); 5167 } 5168 5169 if (CompLHSTy) { 5170 QualType LHSTy = Context.isPromotableBitField(lex); 5171 if (LHSTy.isNull()) { 5172 LHSTy = lex->getType(); 5173 if (LHSTy->isPromotableIntegerType()) 5174 LHSTy = Context.getPromotedIntegerType(LHSTy); 5175 } 5176 *CompLHSTy = LHSTy; 5177 } 5178 return PExp->getType(); 5179 } 5180 } 5181 5182 return InvalidOperands(Loc, lex, rex); 5183} 5184 5185// C99 6.5.6 5186QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 5187 SourceLocation Loc, QualType* CompLHSTy) { 5188 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5189 QualType compType = CheckVectorOperands(Loc, lex, rex); 5190 if (CompLHSTy) *CompLHSTy = compType; 5191 return compType; 5192 } 5193 5194 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 5195 5196 // Enforce type constraints: C99 6.5.6p3. 5197 5198 // Handle the common case first (both operands are arithmetic). 5199 if (lex->getType()->isArithmeticType() 5200 && rex->getType()->isArithmeticType()) { 5201 if (CompLHSTy) *CompLHSTy = compType; 5202 return compType; 5203 } 5204 5205 // Either ptr - int or ptr - ptr. 5206 if (lex->getType()->isAnyPointerType()) { 5207 QualType lpointee = lex->getType()->getPointeeType(); 5208 5209 // The LHS must be an completely-defined object type. 5210 5211 bool ComplainAboutVoid = false; 5212 Expr *ComplainAboutFunc = 0; 5213 if (lpointee->isVoidType()) { 5214 if (getLangOptions().CPlusPlus) { 5215 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5216 << lex->getSourceRange() << rex->getSourceRange(); 5217 return QualType(); 5218 } 5219 5220 // GNU C extension: arithmetic on pointer to void 5221 ComplainAboutVoid = true; 5222 } else if (lpointee->isFunctionType()) { 5223 if (getLangOptions().CPlusPlus) { 5224 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5225 << lex->getType() << lex->getSourceRange(); 5226 return QualType(); 5227 } 5228 5229 // GNU C extension: arithmetic on pointer to function 5230 ComplainAboutFunc = lex; 5231 } else if (!lpointee->isDependentType() && 5232 RequireCompleteType(Loc, lpointee, 5233 PDiag(diag::err_typecheck_sub_ptr_object) 5234 << lex->getSourceRange() 5235 << lex->getType())) 5236 return QualType(); 5237 5238 // Diagnose bad cases where we step over interface counts. 5239 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 5240 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 5241 << lpointee << lex->getSourceRange(); 5242 return QualType(); 5243 } 5244 5245 // The result type of a pointer-int computation is the pointer type. 5246 if (rex->getType()->isIntegerType()) { 5247 if (ComplainAboutVoid) 5248 Diag(Loc, diag::ext_gnu_void_ptr) 5249 << lex->getSourceRange() << rex->getSourceRange(); 5250 if (ComplainAboutFunc) 5251 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5252 << ComplainAboutFunc->getType() 5253 << ComplainAboutFunc->getSourceRange(); 5254 5255 if (CompLHSTy) *CompLHSTy = lex->getType(); 5256 return lex->getType(); 5257 } 5258 5259 // Handle pointer-pointer subtractions. 5260 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 5261 QualType rpointee = RHSPTy->getPointeeType(); 5262 5263 // RHS must be a completely-type object type. 5264 // Handle the GNU void* extension. 5265 if (rpointee->isVoidType()) { 5266 if (getLangOptions().CPlusPlus) { 5267 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 5268 << lex->getSourceRange() << rex->getSourceRange(); 5269 return QualType(); 5270 } 5271 5272 ComplainAboutVoid = true; 5273 } else if (rpointee->isFunctionType()) { 5274 if (getLangOptions().CPlusPlus) { 5275 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 5276 << rex->getType() << rex->getSourceRange(); 5277 return QualType(); 5278 } 5279 5280 // GNU extension: arithmetic on pointer to function 5281 if (!ComplainAboutFunc) 5282 ComplainAboutFunc = rex; 5283 } else if (!rpointee->isDependentType() && 5284 RequireCompleteType(Loc, rpointee, 5285 PDiag(diag::err_typecheck_sub_ptr_object) 5286 << rex->getSourceRange() 5287 << rex->getType())) 5288 return QualType(); 5289 5290 if (getLangOptions().CPlusPlus) { 5291 // Pointee types must be the same: C++ [expr.add] 5292 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 5293 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5294 << lex->getType() << rex->getType() 5295 << lex->getSourceRange() << rex->getSourceRange(); 5296 return QualType(); 5297 } 5298 } else { 5299 // Pointee types must be compatible C99 6.5.6p3 5300 if (!Context.typesAreCompatible( 5301 Context.getCanonicalType(lpointee).getUnqualifiedType(), 5302 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 5303 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 5304 << lex->getType() << rex->getType() 5305 << lex->getSourceRange() << rex->getSourceRange(); 5306 return QualType(); 5307 } 5308 } 5309 5310 if (ComplainAboutVoid) 5311 Diag(Loc, diag::ext_gnu_void_ptr) 5312 << lex->getSourceRange() << rex->getSourceRange(); 5313 if (ComplainAboutFunc) 5314 Diag(Loc, diag::ext_gnu_ptr_func_arith) 5315 << ComplainAboutFunc->getType() 5316 << ComplainAboutFunc->getSourceRange(); 5317 5318 if (CompLHSTy) *CompLHSTy = lex->getType(); 5319 return Context.getPointerDiffType(); 5320 } 5321 } 5322 5323 return InvalidOperands(Loc, lex, rex); 5324} 5325 5326// C99 6.5.7 5327QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5328 bool isCompAssign) { 5329 // C99 6.5.7p2: Each of the operands shall have integer type. 5330 if (!lex->getType()->hasIntegerRepresentation() || 5331 !rex->getType()->hasIntegerRepresentation()) 5332 return InvalidOperands(Loc, lex, rex); 5333 5334 // Vector shifts promote their scalar inputs to vector type. 5335 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5336 return CheckVectorOperands(Loc, lex, rex); 5337 5338 // Shifts don't perform usual arithmetic conversions, they just do integer 5339 // promotions on each operand. C99 6.5.7p3 5340 QualType LHSTy = Context.isPromotableBitField(lex); 5341 if (LHSTy.isNull()) { 5342 LHSTy = lex->getType(); 5343 if (LHSTy->isPromotableIntegerType()) 5344 LHSTy = Context.getPromotedIntegerType(LHSTy); 5345 } 5346 if (!isCompAssign) 5347 ImpCastExprToType(lex, LHSTy, CastExpr::CK_IntegralCast); 5348 5349 UsualUnaryConversions(rex); 5350 5351 // Sanity-check shift operands 5352 llvm::APSInt Right; 5353 // Check right/shifter operand 5354 if (!rex->isValueDependent() && 5355 rex->isIntegerConstantExpr(Right, Context)) { 5356 if (Right.isNegative()) 5357 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 5358 else { 5359 llvm::APInt LeftBits(Right.getBitWidth(), 5360 Context.getTypeSize(lex->getType())); 5361 if (Right.uge(LeftBits)) 5362 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 5363 } 5364 } 5365 5366 // "The type of the result is that of the promoted left operand." 5367 return LHSTy; 5368} 5369 5370static bool IsWithinTemplateSpecialization(Decl *D) { 5371 if (DeclContext *DC = D->getDeclContext()) { 5372 if (isa<ClassTemplateSpecializationDecl>(DC)) 5373 return true; 5374 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 5375 return FD->isFunctionTemplateSpecialization(); 5376 } 5377 return false; 5378} 5379 5380// C99 6.5.8, C++ [expr.rel] 5381QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 5382 unsigned OpaqueOpc, bool isRelational) { 5383 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)OpaqueOpc; 5384 5385 // Handle vector comparisons separately. 5386 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5387 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 5388 5389 QualType lType = lex->getType(); 5390 QualType rType = rex->getType(); 5391 5392 if (!lType->hasFloatingRepresentation() && 5393 !(lType->isBlockPointerType() && isRelational)) { 5394 // For non-floating point types, check for self-comparisons of the form 5395 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5396 // often indicate logic errors in the program. 5397 // 5398 // NOTE: Don't warn about comparison expressions resulting from macro 5399 // expansion. Also don't warn about comparisons which are only self 5400 // comparisons within a template specialization. The warnings should catch 5401 // obvious cases in the definition of the template anyways. The idea is to 5402 // warn when the typed comparison operator will always evaluate to the same 5403 // result. 5404 Expr *LHSStripped = lex->IgnoreParens(); 5405 Expr *RHSStripped = rex->IgnoreParens(); 5406 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 5407 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 5408 if (DRL->getDecl() == DRR->getDecl() && !Loc.isMacroID() && 5409 !IsWithinTemplateSpecialization(DRL->getDecl())) { 5410 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5411 << 0 // self- 5412 << (Opc == BinaryOperator::EQ 5413 || Opc == BinaryOperator::LE 5414 || Opc == BinaryOperator::GE)); 5415 } else if (lType->isArrayType() && rType->isArrayType() && 5416 !DRL->getDecl()->getType()->isReferenceType() && 5417 !DRR->getDecl()->getType()->isReferenceType()) { 5418 // what is it always going to eval to? 5419 char always_evals_to; 5420 switch(Opc) { 5421 case BinaryOperator::EQ: // e.g. array1 == array2 5422 always_evals_to = 0; // false 5423 break; 5424 case BinaryOperator::NE: // e.g. array1 != array2 5425 always_evals_to = 1; // true 5426 break; 5427 default: 5428 // best we can say is 'a constant' 5429 always_evals_to = 2; // e.g. array1 <= array2 5430 break; 5431 } 5432 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 5433 << 1 // array 5434 << always_evals_to); 5435 } 5436 } 5437 } 5438 5439 if (isa<CastExpr>(LHSStripped)) 5440 LHSStripped = LHSStripped->IgnoreParenCasts(); 5441 if (isa<CastExpr>(RHSStripped)) 5442 RHSStripped = RHSStripped->IgnoreParenCasts(); 5443 5444 // Warn about comparisons against a string constant (unless the other 5445 // operand is null), the user probably wants strcmp. 5446 Expr *literalString = 0; 5447 Expr *literalStringStripped = 0; 5448 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 5449 !RHSStripped->isNullPointerConstant(Context, 5450 Expr::NPC_ValueDependentIsNull)) { 5451 literalString = lex; 5452 literalStringStripped = LHSStripped; 5453 } else if ((isa<StringLiteral>(RHSStripped) || 5454 isa<ObjCEncodeExpr>(RHSStripped)) && 5455 !LHSStripped->isNullPointerConstant(Context, 5456 Expr::NPC_ValueDependentIsNull)) { 5457 literalString = rex; 5458 literalStringStripped = RHSStripped; 5459 } 5460 5461 if (literalString) { 5462 std::string resultComparison; 5463 switch (Opc) { 5464 case BinaryOperator::LT: resultComparison = ") < 0"; break; 5465 case BinaryOperator::GT: resultComparison = ") > 0"; break; 5466 case BinaryOperator::LE: resultComparison = ") <= 0"; break; 5467 case BinaryOperator::GE: resultComparison = ") >= 0"; break; 5468 case BinaryOperator::EQ: resultComparison = ") == 0"; break; 5469 case BinaryOperator::NE: resultComparison = ") != 0"; break; 5470 default: assert(false && "Invalid comparison operator"); 5471 } 5472 5473 DiagRuntimeBehavior(Loc, 5474 PDiag(diag::warn_stringcompare) 5475 << isa<ObjCEncodeExpr>(literalStringStripped) 5476 << literalString->getSourceRange()); 5477 } 5478 } 5479 5480 // C99 6.5.8p3 / C99 6.5.9p4 5481 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 5482 UsualArithmeticConversions(lex, rex); 5483 else { 5484 UsualUnaryConversions(lex); 5485 UsualUnaryConversions(rex); 5486 } 5487 5488 lType = lex->getType(); 5489 rType = rex->getType(); 5490 5491 // The result of comparisons is 'bool' in C++, 'int' in C. 5492 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 5493 5494 if (isRelational) { 5495 if (lType->isRealType() && rType->isRealType()) 5496 return ResultTy; 5497 } else { 5498 // Check for comparisons of floating point operands using != and ==. 5499 if (lType->hasFloatingRepresentation()) 5500 CheckFloatComparison(Loc,lex,rex); 5501 5502 if (lType->isArithmeticType() && rType->isArithmeticType()) 5503 return ResultTy; 5504 } 5505 5506 bool LHSIsNull = lex->isNullPointerConstant(Context, 5507 Expr::NPC_ValueDependentIsNull); 5508 bool RHSIsNull = rex->isNullPointerConstant(Context, 5509 Expr::NPC_ValueDependentIsNull); 5510 5511 // All of the following pointer-related warnings are GCC extensions, except 5512 // when handling null pointer constants. 5513 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 5514 QualType LCanPointeeTy = 5515 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 5516 QualType RCanPointeeTy = 5517 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 5518 5519 if (getLangOptions().CPlusPlus) { 5520 if (LCanPointeeTy == RCanPointeeTy) 5521 return ResultTy; 5522 if (!isRelational && 5523 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5524 // Valid unless comparison between non-null pointer and function pointer 5525 // This is a gcc extension compatibility comparison. 5526 // In a SFINAE context, we treat this as a hard error to maintain 5527 // conformance with the C++ standard. 5528 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5529 && !LHSIsNull && !RHSIsNull) { 5530 Diag(Loc, 5531 isSFINAEContext()? 5532 diag::err_typecheck_comparison_of_fptr_to_void 5533 : diag::ext_typecheck_comparison_of_fptr_to_void) 5534 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5535 5536 if (isSFINAEContext()) 5537 return QualType(); 5538 5539 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5540 return ResultTy; 5541 } 5542 } 5543 // C++ [expr.rel]p2: 5544 // [...] Pointer conversions (4.10) and qualification 5545 // conversions (4.4) are performed on pointer operands (or on 5546 // a pointer operand and a null pointer constant) to bring 5547 // them to their composite pointer type. [...] 5548 // 5549 // C++ [expr.eq]p1 uses the same notion for (in)equality 5550 // comparisons of pointers. 5551 bool NonStandardCompositeType = false; 5552 QualType T = FindCompositePointerType(Loc, lex, rex, 5553 isSFINAEContext()? 0 : &NonStandardCompositeType); 5554 if (T.isNull()) { 5555 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5556 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5557 return QualType(); 5558 } else if (NonStandardCompositeType) { 5559 Diag(Loc, 5560 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5561 << lType << rType << T 5562 << lex->getSourceRange() << rex->getSourceRange(); 5563 } 5564 5565 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5566 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5567 return ResultTy; 5568 } 5569 // C99 6.5.9p2 and C99 6.5.8p2 5570 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 5571 RCanPointeeTy.getUnqualifiedType())) { 5572 // Valid unless a relational comparison of function pointers 5573 if (isRelational && LCanPointeeTy->isFunctionType()) { 5574 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 5575 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5576 } 5577 } else if (!isRelational && 5578 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 5579 // Valid unless comparison between non-null pointer and function pointer 5580 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 5581 && !LHSIsNull && !RHSIsNull) { 5582 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 5583 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5584 } 5585 } else { 5586 // Invalid 5587 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5588 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5589 } 5590 if (LCanPointeeTy != RCanPointeeTy) 5591 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5592 return ResultTy; 5593 } 5594 5595 if (getLangOptions().CPlusPlus) { 5596 // Comparison of pointers with null pointer constants and equality 5597 // comparisons of member pointers to null pointer constants. 5598 if (RHSIsNull && 5599 (lType->isPointerType() || 5600 (!isRelational && lType->isMemberPointerType()))) { 5601 ImpCastExprToType(rex, lType, CastExpr::CK_NullToMemberPointer); 5602 return ResultTy; 5603 } 5604 if (LHSIsNull && 5605 (rType->isPointerType() || 5606 (!isRelational && rType->isMemberPointerType()))) { 5607 ImpCastExprToType(lex, rType, CastExpr::CK_NullToMemberPointer); 5608 return ResultTy; 5609 } 5610 5611 // Comparison of member pointers. 5612 if (!isRelational && 5613 lType->isMemberPointerType() && rType->isMemberPointerType()) { 5614 // C++ [expr.eq]p2: 5615 // In addition, pointers to members can be compared, or a pointer to 5616 // member and a null pointer constant. Pointer to member conversions 5617 // (4.11) and qualification conversions (4.4) are performed to bring 5618 // them to a common type. If one operand is a null pointer constant, 5619 // the common type is the type of the other operand. Otherwise, the 5620 // common type is a pointer to member type similar (4.4) to the type 5621 // of one of the operands, with a cv-qualification signature (4.4) 5622 // that is the union of the cv-qualification signatures of the operand 5623 // types. 5624 bool NonStandardCompositeType = false; 5625 QualType T = FindCompositePointerType(Loc, lex, rex, 5626 isSFINAEContext()? 0 : &NonStandardCompositeType); 5627 if (T.isNull()) { 5628 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 5629 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5630 return QualType(); 5631 } else if (NonStandardCompositeType) { 5632 Diag(Loc, 5633 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 5634 << lType << rType << T 5635 << lex->getSourceRange() << rex->getSourceRange(); 5636 } 5637 5638 ImpCastExprToType(lex, T, CastExpr::CK_BitCast); 5639 ImpCastExprToType(rex, T, CastExpr::CK_BitCast); 5640 return ResultTy; 5641 } 5642 5643 // Comparison of nullptr_t with itself. 5644 if (lType->isNullPtrType() && rType->isNullPtrType()) 5645 return ResultTy; 5646 } 5647 5648 // Handle block pointer types. 5649 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 5650 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 5651 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 5652 5653 if (!LHSIsNull && !RHSIsNull && 5654 !Context.typesAreCompatible(lpointee, rpointee)) { 5655 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5656 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5657 } 5658 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5659 return ResultTy; 5660 } 5661 // Allow block pointers to be compared with null pointer constants. 5662 if (!isRelational 5663 && ((lType->isBlockPointerType() && rType->isPointerType()) 5664 || (lType->isPointerType() && rType->isBlockPointerType()))) { 5665 if (!LHSIsNull && !RHSIsNull) { 5666 if (!((rType->isPointerType() && rType->getAs<PointerType>() 5667 ->getPointeeType()->isVoidType()) 5668 || (lType->isPointerType() && lType->getAs<PointerType>() 5669 ->getPointeeType()->isVoidType()))) 5670 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 5671 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5672 } 5673 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5674 return ResultTy; 5675 } 5676 5677 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 5678 if (lType->isPointerType() || rType->isPointerType()) { 5679 const PointerType *LPT = lType->getAs<PointerType>(); 5680 const PointerType *RPT = rType->getAs<PointerType>(); 5681 bool LPtrToVoid = LPT ? 5682 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 5683 bool RPtrToVoid = RPT ? 5684 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 5685 5686 if (!LPtrToVoid && !RPtrToVoid && 5687 !Context.typesAreCompatible(lType, rType)) { 5688 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5689 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5690 } 5691 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5692 return ResultTy; 5693 } 5694 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 5695 if (!Context.areComparableObjCPointerTypes(lType, rType)) 5696 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 5697 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5698 ImpCastExprToType(rex, lType, CastExpr::CK_BitCast); 5699 return ResultTy; 5700 } 5701 } 5702 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 5703 (lType->isIntegerType() && rType->isAnyPointerType())) { 5704 unsigned DiagID = 0; 5705 bool isError = false; 5706 if ((LHSIsNull && lType->isIntegerType()) || 5707 (RHSIsNull && rType->isIntegerType())) { 5708 if (isRelational && !getLangOptions().CPlusPlus) 5709 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 5710 } else if (isRelational && !getLangOptions().CPlusPlus) 5711 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 5712 else if (getLangOptions().CPlusPlus) { 5713 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 5714 isError = true; 5715 } else 5716 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 5717 5718 if (DiagID) { 5719 Diag(Loc, DiagID) 5720 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 5721 if (isError) 5722 return QualType(); 5723 } 5724 5725 if (lType->isIntegerType()) 5726 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5727 else 5728 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5729 return ResultTy; 5730 } 5731 5732 // Handle block pointers. 5733 if (!isRelational && RHSIsNull 5734 && lType->isBlockPointerType() && rType->isIntegerType()) { 5735 ImpCastExprToType(rex, lType, CastExpr::CK_IntegralToPointer); 5736 return ResultTy; 5737 } 5738 if (!isRelational && LHSIsNull 5739 && lType->isIntegerType() && rType->isBlockPointerType()) { 5740 ImpCastExprToType(lex, rType, CastExpr::CK_IntegralToPointer); 5741 return ResultTy; 5742 } 5743 return InvalidOperands(Loc, lex, rex); 5744} 5745 5746/// CheckVectorCompareOperands - vector comparisons are a clang extension that 5747/// operates on extended vector types. Instead of producing an IntTy result, 5748/// like a scalar comparison, a vector comparison produces a vector of integer 5749/// types. 5750QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 5751 SourceLocation Loc, 5752 bool isRelational) { 5753 // Check to make sure we're operating on vectors of the same type and width, 5754 // Allowing one side to be a scalar of element type. 5755 QualType vType = CheckVectorOperands(Loc, lex, rex); 5756 if (vType.isNull()) 5757 return vType; 5758 5759 QualType lType = lex->getType(); 5760 QualType rType = rex->getType(); 5761 5762 // For non-floating point types, check for self-comparisons of the form 5763 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 5764 // often indicate logic errors in the program. 5765 if (!lType->hasFloatingRepresentation()) { 5766 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 5767 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 5768 if (DRL->getDecl() == DRR->getDecl()) 5769 DiagRuntimeBehavior(Loc, 5770 PDiag(diag::warn_comparison_always) 5771 << 0 // self- 5772 << 2 // "a constant" 5773 ); 5774 } 5775 5776 // Check for comparisons of floating point operands using != and ==. 5777 if (!isRelational && lType->hasFloatingRepresentation()) { 5778 assert (rType->hasFloatingRepresentation()); 5779 CheckFloatComparison(Loc,lex,rex); 5780 } 5781 5782 // Return the type for the comparison, which is the same as vector type for 5783 // integer vectors, or an integer type of identical size and number of 5784 // elements for floating point vectors. 5785 if (lType->hasIntegerRepresentation()) 5786 return lType; 5787 5788 const VectorType *VTy = lType->getAs<VectorType>(); 5789 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 5790 if (TypeSize == Context.getTypeSize(Context.IntTy)) 5791 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 5792 if (TypeSize == Context.getTypeSize(Context.LongTy)) 5793 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 5794 5795 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 5796 "Unhandled vector element size in vector compare"); 5797 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 5798} 5799 5800inline QualType Sema::CheckBitwiseOperands( 5801 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5802 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5803 if (lex->getType()->hasIntegerRepresentation() && 5804 rex->getType()->hasIntegerRepresentation()) 5805 return CheckVectorOperands(Loc, lex, rex); 5806 5807 return InvalidOperands(Loc, lex, rex); 5808 } 5809 5810 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5811 5812 if (lex->getType()->isIntegerType() && rex->getType()->isIntegerType()) 5813 return compType; 5814 return InvalidOperands(Loc, lex, rex); 5815} 5816 5817inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 5818 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 5819 5820 // Diagnose cases where the user write a logical and/or but probably meant a 5821 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 5822 // is a constant. 5823 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 5824 rex->getType()->isIntegerType() && !rex->isValueDependent() && 5825 // Don't warn in macros. 5826 !Loc.isMacroID()) { 5827 // If the RHS can be constant folded, and if it constant folds to something 5828 // that isn't 0 or 1 (which indicate a potential logical operation that 5829 // happened to fold to true/false) then warn. 5830 Expr::EvalResult Result; 5831 if (rex->Evaluate(Result, Context) && !Result.HasSideEffects && 5832 Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { 5833 Diag(Loc, diag::warn_logical_instead_of_bitwise) 5834 << rex->getSourceRange() 5835 << (Opc == BinaryOperator::LAnd ? "&&" : "||") 5836 << (Opc == BinaryOperator::LAnd ? "&" : "|"); 5837 } 5838 } 5839 5840 if (!Context.getLangOptions().CPlusPlus) { 5841 UsualUnaryConversions(lex); 5842 UsualUnaryConversions(rex); 5843 5844 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 5845 return InvalidOperands(Loc, lex, rex); 5846 5847 return Context.IntTy; 5848 } 5849 5850 // The following is safe because we only use this method for 5851 // non-overloadable operands. 5852 5853 // C++ [expr.log.and]p1 5854 // C++ [expr.log.or]p1 5855 // The operands are both contextually converted to type bool. 5856 if (PerformContextuallyConvertToBool(lex) || 5857 PerformContextuallyConvertToBool(rex)) 5858 return InvalidOperands(Loc, lex, rex); 5859 5860 // C++ [expr.log.and]p2 5861 // C++ [expr.log.or]p2 5862 // The result is a bool. 5863 return Context.BoolTy; 5864} 5865 5866/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 5867/// is a read-only property; return true if so. A readonly property expression 5868/// depends on various declarations and thus must be treated specially. 5869/// 5870static bool IsReadonlyProperty(Expr *E, Sema &S) { 5871 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 5872 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 5873 if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) { 5874 QualType BaseType = PropExpr->getBase()->getType(); 5875 if (const ObjCObjectPointerType *OPT = 5876 BaseType->getAsObjCInterfacePointerType()) 5877 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 5878 if (S.isPropertyReadonly(PDecl, IFace)) 5879 return true; 5880 } 5881 } 5882 return false; 5883} 5884 5885/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 5886/// emit an error and return true. If so, return false. 5887static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 5888 SourceLocation OrigLoc = Loc; 5889 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 5890 &Loc); 5891 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 5892 IsLV = Expr::MLV_ReadonlyProperty; 5893 if (IsLV == Expr::MLV_Valid) 5894 return false; 5895 5896 unsigned Diag = 0; 5897 bool NeedType = false; 5898 switch (IsLV) { // C99 6.5.16p2 5899 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 5900 case Expr::MLV_ArrayType: 5901 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 5902 NeedType = true; 5903 break; 5904 case Expr::MLV_NotObjectType: 5905 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 5906 NeedType = true; 5907 break; 5908 case Expr::MLV_LValueCast: 5909 Diag = diag::err_typecheck_lvalue_casts_not_supported; 5910 break; 5911 case Expr::MLV_Valid: 5912 llvm_unreachable("did not take early return for MLV_Valid"); 5913 case Expr::MLV_InvalidExpression: 5914 case Expr::MLV_MemberFunction: 5915 case Expr::MLV_ClassTemporary: 5916 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 5917 break; 5918 case Expr::MLV_IncompleteType: 5919 case Expr::MLV_IncompleteVoidType: 5920 return S.RequireCompleteType(Loc, E->getType(), 5921 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 5922 << E->getSourceRange()); 5923 case Expr::MLV_DuplicateVectorComponents: 5924 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 5925 break; 5926 case Expr::MLV_NotBlockQualified: 5927 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 5928 break; 5929 case Expr::MLV_ReadonlyProperty: 5930 Diag = diag::error_readonly_property_assignment; 5931 break; 5932 case Expr::MLV_NoSetterProperty: 5933 Diag = diag::error_nosetter_property_assignment; 5934 break; 5935 case Expr::MLV_SubObjCPropertySetting: 5936 Diag = diag::error_no_subobject_property_setting; 5937 break; 5938 } 5939 5940 SourceRange Assign; 5941 if (Loc != OrigLoc) 5942 Assign = SourceRange(OrigLoc, OrigLoc); 5943 if (NeedType) 5944 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 5945 else 5946 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 5947 return true; 5948} 5949 5950 5951 5952// C99 6.5.16.1 5953QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 5954 SourceLocation Loc, 5955 QualType CompoundType) { 5956 // Verify that LHS is a modifiable lvalue, and emit error if not. 5957 if (CheckForModifiableLvalue(LHS, Loc, *this)) 5958 return QualType(); 5959 5960 QualType LHSType = LHS->getType(); 5961 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 5962 AssignConvertType ConvTy; 5963 if (CompoundType.isNull()) { 5964 QualType LHSTy(LHSType); 5965 // Simple assignment "x = y". 5966 if (const ObjCImplicitSetterGetterRefExpr *OISGE = 5967 dyn_cast<ObjCImplicitSetterGetterRefExpr>(LHS)) { 5968 // If using property-dot syntax notation for assignment, and there is a 5969 // setter, RHS expression is being passed to the setter argument. So, 5970 // type conversion (and comparison) is RHS to setter's argument type. 5971 if (const ObjCMethodDecl *SetterMD = OISGE->getSetterMethod()) { 5972 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 5973 LHSTy = (*P)->getType(); 5974 } 5975 } 5976 5977 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 5978 // Special case of NSObject attributes on c-style pointer types. 5979 if (ConvTy == IncompatiblePointer && 5980 ((Context.isObjCNSObjectType(LHSType) && 5981 RHSType->isObjCObjectPointerType()) || 5982 (Context.isObjCNSObjectType(RHSType) && 5983 LHSType->isObjCObjectPointerType()))) 5984 ConvTy = Compatible; 5985 5986 // If the RHS is a unary plus or minus, check to see if they = and + are 5987 // right next to each other. If so, the user may have typo'd "x =+ 4" 5988 // instead of "x += 4". 5989 Expr *RHSCheck = RHS; 5990 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 5991 RHSCheck = ICE->getSubExpr(); 5992 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 5993 if ((UO->getOpcode() == UnaryOperator::Plus || 5994 UO->getOpcode() == UnaryOperator::Minus) && 5995 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 5996 // Only if the two operators are exactly adjacent. 5997 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 5998 // And there is a space or other character before the subexpr of the 5999 // unary +/-. We don't want to warn on "x=-1". 6000 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 6001 UO->getSubExpr()->getLocStart().isFileID()) { 6002 Diag(Loc, diag::warn_not_compound_assign) 6003 << (UO->getOpcode() == UnaryOperator::Plus ? "+" : "-") 6004 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 6005 } 6006 } 6007 } else { 6008 // Compound assignment "x += y" 6009 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 6010 } 6011 6012 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 6013 RHS, AA_Assigning)) 6014 return QualType(); 6015 6016 6017 // Check to see if the destination operand is a dereferenced null pointer. If 6018 // so, and if not volatile-qualified, this is undefined behavior that the 6019 // optimizer will delete, so warn about it. People sometimes try to use this 6020 // to get a deterministic trap and are surprised by clang's behavior. This 6021 // only handles the pattern "*null = whatever", which is a very syntactic 6022 // check. 6023 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 6024 if (UO->getOpcode() == UnaryOperator::Deref && 6025 UO->getSubExpr()->IgnoreParenCasts()-> 6026 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 6027 !UO->getType().isVolatileQualified()) { 6028 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 6029 << UO->getSubExpr()->getSourceRange(); 6030 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 6031 } 6032 6033 // C99 6.5.16p3: The type of an assignment expression is the type of the 6034 // left operand unless the left operand has qualified type, in which case 6035 // it is the unqualified version of the type of the left operand. 6036 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 6037 // is converted to the type of the assignment expression (above). 6038 // C++ 5.17p1: the type of the assignment expression is that of its left 6039 // operand. 6040 return LHSType.getUnqualifiedType(); 6041} 6042 6043// C99 6.5.17 6044QualType Sema::CheckCommaOperands(Expr *LHS, Expr *&RHS, SourceLocation Loc) { 6045 DiagnoseUnusedExprResult(LHS); 6046 6047 // Comma performs lvalue conversion (C99 6.3.2.1), but not unary conversions. 6048 // C++ does not perform this conversion (C++ [expr.comma]p1). 6049 if (!getLangOptions().CPlusPlus) 6050 DefaultFunctionArrayLvalueConversion(RHS); 6051 6052 // FIXME: Check that RHS type is complete in C mode (it's legal for it to be 6053 // incomplete in C++). 6054 6055 return RHS->getType(); 6056} 6057 6058/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 6059/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 6060QualType Sema::CheckIncrementDecrementOperand(Expr *Op, SourceLocation OpLoc, 6061 bool isInc, bool isPrefix) { 6062 if (Op->isTypeDependent()) 6063 return Context.DependentTy; 6064 6065 QualType ResType = Op->getType(); 6066 assert(!ResType.isNull() && "no type for increment/decrement expression"); 6067 6068 if (getLangOptions().CPlusPlus && ResType->isBooleanType()) { 6069 // Decrement of bool is not allowed. 6070 if (!isInc) { 6071 Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 6072 return QualType(); 6073 } 6074 // Increment of bool sets it to true, but is deprecated. 6075 Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 6076 } else if (ResType->isRealType()) { 6077 // OK! 6078 } else if (ResType->isAnyPointerType()) { 6079 QualType PointeeTy = ResType->getPointeeType(); 6080 6081 // C99 6.5.2.4p2, 6.5.6p2 6082 if (PointeeTy->isVoidType()) { 6083 if (getLangOptions().CPlusPlus) { 6084 Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 6085 << Op->getSourceRange(); 6086 return QualType(); 6087 } 6088 6089 // Pointer to void is a GNU extension in C. 6090 Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 6091 } else if (PointeeTy->isFunctionType()) { 6092 if (getLangOptions().CPlusPlus) { 6093 Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 6094 << Op->getType() << Op->getSourceRange(); 6095 return QualType(); 6096 } 6097 6098 Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 6099 << ResType << Op->getSourceRange(); 6100 } else if (RequireCompleteType(OpLoc, PointeeTy, 6101 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6102 << Op->getSourceRange() 6103 << ResType)) 6104 return QualType(); 6105 // Diagnose bad cases where we step over interface counts. 6106 else if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6107 Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 6108 << PointeeTy << Op->getSourceRange(); 6109 return QualType(); 6110 } 6111 } else if (ResType->isAnyComplexType()) { 6112 // C99 does not support ++/-- on complex types, we allow as an extension. 6113 Diag(OpLoc, diag::ext_integer_increment_complex) 6114 << ResType << Op->getSourceRange(); 6115 } else { 6116 Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 6117 << ResType << int(isInc) << Op->getSourceRange(); 6118 return QualType(); 6119 } 6120 // At this point, we know we have a real, complex or pointer type. 6121 // Now make sure the operand is a modifiable lvalue. 6122 if (CheckForModifiableLvalue(Op, OpLoc, *this)) 6123 return QualType(); 6124 // In C++, a prefix increment is the same type as the operand. Otherwise 6125 // (in C or with postfix), the increment is the unqualified type of the 6126 // operand. 6127 return isPrefix && getLangOptions().CPlusPlus 6128 ? ResType : ResType.getUnqualifiedType(); 6129} 6130 6131/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 6132/// This routine allows us to typecheck complex/recursive expressions 6133/// where the declaration is needed for type checking. We only need to 6134/// handle cases when the expression references a function designator 6135/// or is an lvalue. Here are some examples: 6136/// - &(x) => x 6137/// - &*****f => f for f a function designator. 6138/// - &s.xx => s 6139/// - &s.zz[1].yy -> s, if zz is an array 6140/// - *(x + 1) -> x, if x is an array 6141/// - &"123"[2] -> 0 6142/// - & __real__ x -> x 6143static NamedDecl *getPrimaryDecl(Expr *E) { 6144 switch (E->getStmtClass()) { 6145 case Stmt::DeclRefExprClass: 6146 return cast<DeclRefExpr>(E)->getDecl(); 6147 case Stmt::MemberExprClass: 6148 // If this is an arrow operator, the address is an offset from 6149 // the base's value, so the object the base refers to is 6150 // irrelevant. 6151 if (cast<MemberExpr>(E)->isArrow()) 6152 return 0; 6153 // Otherwise, the expression refers to a part of the base 6154 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 6155 case Stmt::ArraySubscriptExprClass: { 6156 // FIXME: This code shouldn't be necessary! We should catch the implicit 6157 // promotion of register arrays earlier. 6158 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 6159 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 6160 if (ICE->getSubExpr()->getType()->isArrayType()) 6161 return getPrimaryDecl(ICE->getSubExpr()); 6162 } 6163 return 0; 6164 } 6165 case Stmt::UnaryOperatorClass: { 6166 UnaryOperator *UO = cast<UnaryOperator>(E); 6167 6168 switch(UO->getOpcode()) { 6169 case UnaryOperator::Real: 6170 case UnaryOperator::Imag: 6171 case UnaryOperator::Extension: 6172 return getPrimaryDecl(UO->getSubExpr()); 6173 default: 6174 return 0; 6175 } 6176 } 6177 case Stmt::ParenExprClass: 6178 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 6179 case Stmt::ImplicitCastExprClass: 6180 // If the result of an implicit cast is an l-value, we care about 6181 // the sub-expression; otherwise, the result here doesn't matter. 6182 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 6183 default: 6184 return 0; 6185 } 6186} 6187 6188/// CheckAddressOfOperand - The operand of & must be either a function 6189/// designator or an lvalue designating an object. If it is an lvalue, the 6190/// object cannot be declared with storage class register or be a bit field. 6191/// Note: The usual conversions are *not* applied to the operand of the & 6192/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 6193/// In C++, the operand might be an overloaded function name, in which case 6194/// we allow the '&' but retain the overloaded-function type. 6195QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) { 6196 // Make sure to ignore parentheses in subsequent checks 6197 op = op->IgnoreParens(); 6198 6199 if (op->isTypeDependent()) 6200 return Context.DependentTy; 6201 6202 if (getLangOptions().C99) { 6203 // Implement C99-only parts of addressof rules. 6204 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 6205 if (uOp->getOpcode() == UnaryOperator::Deref) 6206 // Per C99 6.5.3.2, the address of a deref always returns a valid result 6207 // (assuming the deref expression is valid). 6208 return uOp->getSubExpr()->getType(); 6209 } 6210 // Technically, there should be a check for array subscript 6211 // expressions here, but the result of one is always an lvalue anyway. 6212 } 6213 NamedDecl *dcl = getPrimaryDecl(op); 6214 Expr::isLvalueResult lval = op->isLvalue(Context); 6215 6216 MemberExpr *ME = dyn_cast<MemberExpr>(op); 6217 if (lval == Expr::LV_MemberFunction && ME && 6218 isa<CXXMethodDecl>(ME->getMemberDecl())) { 6219 ValueDecl *dcl = cast<MemberExpr>(op)->getMemberDecl(); 6220 // &f where f is a member of the current object, or &o.f, or &p->f 6221 // All these are not allowed, and we need to catch them before the dcl 6222 // branch of the if, below. 6223 Diag(OpLoc, diag::err_unqualified_pointer_member_function) 6224 << dcl; 6225 // FIXME: Improve this diagnostic and provide a fixit. 6226 6227 // Now recover by acting as if the function had been accessed qualified. 6228 return Context.getMemberPointerType(op->getType(), 6229 Context.getTypeDeclType(cast<RecordDecl>(dcl->getDeclContext())) 6230 .getTypePtr()); 6231 } 6232 6233 if (lval == Expr::LV_ClassTemporary) { 6234 Diag(OpLoc, isSFINAEContext()? diag::err_typecheck_addrof_class_temporary 6235 : diag::ext_typecheck_addrof_class_temporary) 6236 << op->getType() << op->getSourceRange(); 6237 if (isSFINAEContext()) 6238 return QualType(); 6239 } else if (isa<ObjCSelectorExpr>(op)) 6240 return Context.getPointerType(op->getType()); 6241 else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 6242 // C99 6.5.3.2p1 6243 // The operand must be either an l-value or a function designator 6244 if (!op->getType()->isFunctionType()) { 6245 // FIXME: emit more specific diag... 6246 Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 6247 << op->getSourceRange(); 6248 return QualType(); 6249 } 6250 } else if (op->getBitField()) { // C99 6.5.3.2p1 6251 // The operand cannot be a bit-field 6252 Diag(OpLoc, diag::err_typecheck_address_of) 6253 << "bit-field" << op->getSourceRange(); 6254 return QualType(); 6255 } else if (op->refersToVectorElement()) { 6256 // The operand cannot be an element of a vector 6257 Diag(OpLoc, diag::err_typecheck_address_of) 6258 << "vector element" << op->getSourceRange(); 6259 return QualType(); 6260 } else if (isa<ObjCPropertyRefExpr>(op)) { 6261 // cannot take address of a property expression. 6262 Diag(OpLoc, diag::err_typecheck_address_of) 6263 << "property expression" << op->getSourceRange(); 6264 return QualType(); 6265 } else if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(op)) { 6266 // FIXME: Can LHS ever be null here? 6267 if (!CheckAddressOfOperand(CO->getTrueExpr(), OpLoc).isNull()) 6268 return CheckAddressOfOperand(CO->getFalseExpr(), OpLoc); 6269 } else if (isa<UnresolvedLookupExpr>(op)) { 6270 return Context.OverloadTy; 6271 } else if (dcl) { // C99 6.5.3.2p1 6272 // We have an lvalue with a decl. Make sure the decl is not declared 6273 // with the register storage-class specifier. 6274 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 6275 if (vd->getStorageClass() == VarDecl::Register) { 6276 Diag(OpLoc, diag::err_typecheck_address_of) 6277 << "register variable" << op->getSourceRange(); 6278 return QualType(); 6279 } 6280 } else if (isa<FunctionTemplateDecl>(dcl)) { 6281 return Context.OverloadTy; 6282 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 6283 // Okay: we can take the address of a field. 6284 // Could be a pointer to member, though, if there is an explicit 6285 // scope qualifier for the class. 6286 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 6287 DeclContext *Ctx = dcl->getDeclContext(); 6288 if (Ctx && Ctx->isRecord()) { 6289 if (FD->getType()->isReferenceType()) { 6290 Diag(OpLoc, 6291 diag::err_cannot_form_pointer_to_member_of_reference_type) 6292 << FD->getDeclName() << FD->getType(); 6293 return QualType(); 6294 } 6295 6296 return Context.getMemberPointerType(op->getType(), 6297 Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 6298 } 6299 } 6300 } else if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(dcl)) { 6301 // Okay: we can take the address of a function. 6302 // As above. 6303 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier() && 6304 MD->isInstance()) 6305 return Context.getMemberPointerType(op->getType(), 6306 Context.getTypeDeclType(MD->getParent()).getTypePtr()); 6307 } else if (!isa<FunctionDecl>(dcl)) 6308 assert(0 && "Unknown/unexpected decl type"); 6309 } 6310 6311 if (lval == Expr::LV_IncompleteVoidType) { 6312 // Taking the address of a void variable is technically illegal, but we 6313 // allow it in cases which are otherwise valid. 6314 // Example: "extern void x; void* y = &x;". 6315 Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 6316 } 6317 6318 // If the operand has type "type", the result has type "pointer to type". 6319 if (op->getType()->isObjCObjectType()) 6320 return Context.getObjCObjectPointerType(op->getType()); 6321 return Context.getPointerType(op->getType()); 6322} 6323 6324/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 6325QualType Sema::CheckIndirectionOperand(Expr *Op, SourceLocation OpLoc) { 6326 if (Op->isTypeDependent()) 6327 return Context.DependentTy; 6328 6329 UsualUnaryConversions(Op); 6330 QualType OpTy = Op->getType(); 6331 QualType Result; 6332 6333 // Note that per both C89 and C99, indirection is always legal, even if OpTy 6334 // is an incomplete type or void. It would be possible to warn about 6335 // dereferencing a void pointer, but it's completely well-defined, and such a 6336 // warning is unlikely to catch any mistakes. 6337 if (const PointerType *PT = OpTy->getAs<PointerType>()) 6338 Result = PT->getPointeeType(); 6339 else if (const ObjCObjectPointerType *OPT = 6340 OpTy->getAs<ObjCObjectPointerType>()) 6341 Result = OPT->getPointeeType(); 6342 6343 if (Result.isNull()) { 6344 Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 6345 << OpTy << Op->getSourceRange(); 6346 return QualType(); 6347 } 6348 6349 return Result; 6350} 6351 6352static inline BinaryOperator::Opcode ConvertTokenKindToBinaryOpcode( 6353 tok::TokenKind Kind) { 6354 BinaryOperator::Opcode Opc; 6355 switch (Kind) { 6356 default: assert(0 && "Unknown binop!"); 6357 case tok::periodstar: Opc = BinaryOperator::PtrMemD; break; 6358 case tok::arrowstar: Opc = BinaryOperator::PtrMemI; break; 6359 case tok::star: Opc = BinaryOperator::Mul; break; 6360 case tok::slash: Opc = BinaryOperator::Div; break; 6361 case tok::percent: Opc = BinaryOperator::Rem; break; 6362 case tok::plus: Opc = BinaryOperator::Add; break; 6363 case tok::minus: Opc = BinaryOperator::Sub; break; 6364 case tok::lessless: Opc = BinaryOperator::Shl; break; 6365 case tok::greatergreater: Opc = BinaryOperator::Shr; break; 6366 case tok::lessequal: Opc = BinaryOperator::LE; break; 6367 case tok::less: Opc = BinaryOperator::LT; break; 6368 case tok::greaterequal: Opc = BinaryOperator::GE; break; 6369 case tok::greater: Opc = BinaryOperator::GT; break; 6370 case tok::exclaimequal: Opc = BinaryOperator::NE; break; 6371 case tok::equalequal: Opc = BinaryOperator::EQ; break; 6372 case tok::amp: Opc = BinaryOperator::And; break; 6373 case tok::caret: Opc = BinaryOperator::Xor; break; 6374 case tok::pipe: Opc = BinaryOperator::Or; break; 6375 case tok::ampamp: Opc = BinaryOperator::LAnd; break; 6376 case tok::pipepipe: Opc = BinaryOperator::LOr; break; 6377 case tok::equal: Opc = BinaryOperator::Assign; break; 6378 case tok::starequal: Opc = BinaryOperator::MulAssign; break; 6379 case tok::slashequal: Opc = BinaryOperator::DivAssign; break; 6380 case tok::percentequal: Opc = BinaryOperator::RemAssign; break; 6381 case tok::plusequal: Opc = BinaryOperator::AddAssign; break; 6382 case tok::minusequal: Opc = BinaryOperator::SubAssign; break; 6383 case tok::lesslessequal: Opc = BinaryOperator::ShlAssign; break; 6384 case tok::greatergreaterequal: Opc = BinaryOperator::ShrAssign; break; 6385 case tok::ampequal: Opc = BinaryOperator::AndAssign; break; 6386 case tok::caretequal: Opc = BinaryOperator::XorAssign; break; 6387 case tok::pipeequal: Opc = BinaryOperator::OrAssign; break; 6388 case tok::comma: Opc = BinaryOperator::Comma; break; 6389 } 6390 return Opc; 6391} 6392 6393static inline UnaryOperator::Opcode ConvertTokenKindToUnaryOpcode( 6394 tok::TokenKind Kind) { 6395 UnaryOperator::Opcode Opc; 6396 switch (Kind) { 6397 default: assert(0 && "Unknown unary op!"); 6398 case tok::plusplus: Opc = UnaryOperator::PreInc; break; 6399 case tok::minusminus: Opc = UnaryOperator::PreDec; break; 6400 case tok::amp: Opc = UnaryOperator::AddrOf; break; 6401 case tok::star: Opc = UnaryOperator::Deref; break; 6402 case tok::plus: Opc = UnaryOperator::Plus; break; 6403 case tok::minus: Opc = UnaryOperator::Minus; break; 6404 case tok::tilde: Opc = UnaryOperator::Not; break; 6405 case tok::exclaim: Opc = UnaryOperator::LNot; break; 6406 case tok::kw___real: Opc = UnaryOperator::Real; break; 6407 case tok::kw___imag: Opc = UnaryOperator::Imag; break; 6408 case tok::kw___extension__: Opc = UnaryOperator::Extension; break; 6409 } 6410 return Opc; 6411} 6412 6413/// CreateBuiltinBinOp - Creates a new built-in binary operation with 6414/// operator @p Opc at location @c TokLoc. This routine only supports 6415/// built-in operations; ActOnBinOp handles overloaded operators. 6416Action::OwningExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 6417 unsigned Op, 6418 Expr *lhs, Expr *rhs) { 6419 QualType ResultTy; // Result type of the binary operator. 6420 BinaryOperator::Opcode Opc = (BinaryOperator::Opcode)Op; 6421 // The following two variables are used for compound assignment operators 6422 QualType CompLHSTy; // Type of LHS after promotions for computation 6423 QualType CompResultTy; // Type of computation result 6424 6425 switch (Opc) { 6426 case BinaryOperator::Assign: 6427 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 6428 break; 6429 case BinaryOperator::PtrMemD: 6430 case BinaryOperator::PtrMemI: 6431 ResultTy = CheckPointerToMemberOperands(lhs, rhs, OpLoc, 6432 Opc == BinaryOperator::PtrMemI); 6433 break; 6434 case BinaryOperator::Mul: 6435 case BinaryOperator::Div: 6436 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 6437 Opc == BinaryOperator::Div); 6438 break; 6439 case BinaryOperator::Rem: 6440 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 6441 break; 6442 case BinaryOperator::Add: 6443 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 6444 break; 6445 case BinaryOperator::Sub: 6446 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 6447 break; 6448 case BinaryOperator::Shl: 6449 case BinaryOperator::Shr: 6450 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 6451 break; 6452 case BinaryOperator::LE: 6453 case BinaryOperator::LT: 6454 case BinaryOperator::GE: 6455 case BinaryOperator::GT: 6456 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 6457 break; 6458 case BinaryOperator::EQ: 6459 case BinaryOperator::NE: 6460 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 6461 break; 6462 case BinaryOperator::And: 6463 case BinaryOperator::Xor: 6464 case BinaryOperator::Or: 6465 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 6466 break; 6467 case BinaryOperator::LAnd: 6468 case BinaryOperator::LOr: 6469 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 6470 break; 6471 case BinaryOperator::MulAssign: 6472 case BinaryOperator::DivAssign: 6473 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 6474 Opc == BinaryOperator::DivAssign); 6475 CompLHSTy = CompResultTy; 6476 if (!CompResultTy.isNull()) 6477 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6478 break; 6479 case BinaryOperator::RemAssign: 6480 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 6481 CompLHSTy = CompResultTy; 6482 if (!CompResultTy.isNull()) 6483 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6484 break; 6485 case BinaryOperator::AddAssign: 6486 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6487 if (!CompResultTy.isNull()) 6488 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6489 break; 6490 case BinaryOperator::SubAssign: 6491 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 6492 if (!CompResultTy.isNull()) 6493 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6494 break; 6495 case BinaryOperator::ShlAssign: 6496 case BinaryOperator::ShrAssign: 6497 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 6498 CompLHSTy = CompResultTy; 6499 if (!CompResultTy.isNull()) 6500 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6501 break; 6502 case BinaryOperator::AndAssign: 6503 case BinaryOperator::XorAssign: 6504 case BinaryOperator::OrAssign: 6505 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 6506 CompLHSTy = CompResultTy; 6507 if (!CompResultTy.isNull()) 6508 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 6509 break; 6510 case BinaryOperator::Comma: 6511 ResultTy = CheckCommaOperands(lhs, rhs, OpLoc); 6512 break; 6513 } 6514 if (ResultTy.isNull()) 6515 return ExprError(); 6516 if (CompResultTy.isNull()) 6517 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, OpLoc)); 6518 else 6519 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 6520 CompLHSTy, CompResultTy, 6521 OpLoc)); 6522} 6523 6524/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 6525/// ParenRange in parentheses. 6526static void SuggestParentheses(Sema &Self, SourceLocation Loc, 6527 const PartialDiagnostic &PD, 6528 const PartialDiagnostic &FirstNote, 6529 SourceRange FirstParenRange, 6530 const PartialDiagnostic &SecondNote, 6531 SourceRange SecondParenRange) { 6532 Self.Diag(Loc, PD); 6533 6534 if (!FirstNote.getDiagID()) 6535 return; 6536 6537 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 6538 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6539 // We can't display the parentheses, so just return. 6540 return; 6541 } 6542 6543 Self.Diag(Loc, FirstNote) 6544 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 6545 << FixItHint::CreateInsertion(EndLoc, ")"); 6546 6547 if (!SecondNote.getDiagID()) 6548 return; 6549 6550 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 6551 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 6552 // We can't display the parentheses, so just dig the 6553 // warning/error and return. 6554 Self.Diag(Loc, SecondNote); 6555 return; 6556 } 6557 6558 Self.Diag(Loc, SecondNote) 6559 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 6560 << FixItHint::CreateInsertion(EndLoc, ")"); 6561} 6562 6563/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 6564/// operators are mixed in a way that suggests that the programmer forgot that 6565/// comparison operators have higher precedence. The most typical example of 6566/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 6567static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6568 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 6569 typedef BinaryOperator BinOp; 6570 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 6571 rhsopc = static_cast<BinOp::Opcode>(-1); 6572 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 6573 lhsopc = BO->getOpcode(); 6574 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 6575 rhsopc = BO->getOpcode(); 6576 6577 // Subs are not binary operators. 6578 if (lhsopc == -1 && rhsopc == -1) 6579 return; 6580 6581 // Bitwise operations are sometimes used as eager logical ops. 6582 // Don't diagnose this. 6583 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 6584 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 6585 return; 6586 6587 if (BinOp::isComparisonOp(lhsopc)) 6588 SuggestParentheses(Self, OpLoc, 6589 Self.PDiag(diag::warn_precedence_bitwise_rel) 6590 << SourceRange(lhs->getLocStart(), OpLoc) 6591 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 6592 Self.PDiag(diag::note_precedence_bitwise_first) 6593 << BinOp::getOpcodeStr(Opc), 6594 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 6595 Self.PDiag(diag::note_precedence_bitwise_silence) 6596 << BinOp::getOpcodeStr(lhsopc), 6597 lhs->getSourceRange()); 6598 else if (BinOp::isComparisonOp(rhsopc)) 6599 SuggestParentheses(Self, OpLoc, 6600 Self.PDiag(diag::warn_precedence_bitwise_rel) 6601 << SourceRange(OpLoc, rhs->getLocEnd()) 6602 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 6603 Self.PDiag(diag::note_precedence_bitwise_first) 6604 << BinOp::getOpcodeStr(Opc), 6605 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 6606 Self.PDiag(diag::note_precedence_bitwise_silence) 6607 << BinOp::getOpcodeStr(rhsopc), 6608 rhs->getSourceRange()); 6609} 6610 6611/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 6612/// precedence. This currently diagnoses only "arg1 'bitwise' arg2 'eq' arg3". 6613/// But it could also warn about arg1 && arg2 || arg3, as GCC 4.3+ does. 6614static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperator::Opcode Opc, 6615 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 6616 if (BinaryOperator::isBitwiseOp(Opc)) 6617 DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 6618} 6619 6620// Binary Operators. 'Tok' is the token for the operator. 6621Action::OwningExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 6622 tok::TokenKind Kind, 6623 ExprArg LHS, ExprArg RHS) { 6624 BinaryOperator::Opcode Opc = ConvertTokenKindToBinaryOpcode(Kind); 6625 Expr *lhs = LHS.takeAs<Expr>(), *rhs = RHS.takeAs<Expr>(); 6626 6627 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 6628 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 6629 6630 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 6631 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 6632 6633 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 6634} 6635 6636Action::OwningExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 6637 BinaryOperator::Opcode Opc, 6638 Expr *lhs, Expr *rhs) { 6639 if (getLangOptions().CPlusPlus && 6640 (lhs->getType()->isOverloadableType() || 6641 rhs->getType()->isOverloadableType())) { 6642 // Find all of the overloaded operators visible from this 6643 // point. We perform both an operator-name lookup from the local 6644 // scope and an argument-dependent lookup based on the types of 6645 // the arguments. 6646 UnresolvedSet<16> Functions; 6647 OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); 6648 if (S && OverOp != OO_None) 6649 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 6650 Functions); 6651 6652 // Build the (potentially-overloaded, potentially-dependent) 6653 // binary operation. 6654 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 6655 } 6656 6657 // Build a built-in binary operation. 6658 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 6659} 6660 6661Action::OwningExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 6662 unsigned OpcIn, 6663 ExprArg InputArg) { 6664 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6665 6666 // FIXME: Input is modified below, but InputArg is not updated appropriately. 6667 Expr *Input = (Expr *)InputArg.get(); 6668 QualType resultType; 6669 switch (Opc) { 6670 case UnaryOperator::OffsetOf: 6671 assert(false && "Invalid unary operator"); 6672 break; 6673 6674 case UnaryOperator::PreInc: 6675 case UnaryOperator::PreDec: 6676 case UnaryOperator::PostInc: 6677 case UnaryOperator::PostDec: 6678 resultType = CheckIncrementDecrementOperand(Input, OpLoc, 6679 Opc == UnaryOperator::PreInc || 6680 Opc == UnaryOperator::PostInc, 6681 Opc == UnaryOperator::PreInc || 6682 Opc == UnaryOperator::PreDec); 6683 break; 6684 case UnaryOperator::AddrOf: 6685 resultType = CheckAddressOfOperand(Input, OpLoc); 6686 break; 6687 case UnaryOperator::Deref: 6688 DefaultFunctionArrayLvalueConversion(Input); 6689 resultType = CheckIndirectionOperand(Input, OpLoc); 6690 break; 6691 case UnaryOperator::Plus: 6692 case UnaryOperator::Minus: 6693 UsualUnaryConversions(Input); 6694 resultType = Input->getType(); 6695 if (resultType->isDependentType()) 6696 break; 6697 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 6698 resultType->isVectorType()) 6699 break; 6700 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 6701 resultType->isEnumeralType()) 6702 break; 6703 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 6704 Opc == UnaryOperator::Plus && 6705 resultType->isPointerType()) 6706 break; 6707 6708 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6709 << resultType << Input->getSourceRange()); 6710 case UnaryOperator::Not: // bitwise complement 6711 UsualUnaryConversions(Input); 6712 resultType = Input->getType(); 6713 if (resultType->isDependentType()) 6714 break; 6715 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 6716 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 6717 // C99 does not support '~' for complex conjugation. 6718 Diag(OpLoc, diag::ext_integer_complement_complex) 6719 << resultType << Input->getSourceRange(); 6720 else if (!resultType->hasIntegerRepresentation()) 6721 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6722 << resultType << Input->getSourceRange()); 6723 break; 6724 case UnaryOperator::LNot: // logical negation 6725 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 6726 DefaultFunctionArrayLvalueConversion(Input); 6727 resultType = Input->getType(); 6728 if (resultType->isDependentType()) 6729 break; 6730 if (!resultType->isScalarType()) // C99 6.5.3.3p1 6731 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 6732 << resultType << Input->getSourceRange()); 6733 // LNot always has type int. C99 6.5.3.3p5. 6734 // In C++, it's bool. C++ 5.3.1p8 6735 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 6736 break; 6737 case UnaryOperator::Real: 6738 case UnaryOperator::Imag: 6739 resultType = CheckRealImagOperand(Input, OpLoc, Opc == UnaryOperator::Real); 6740 break; 6741 case UnaryOperator::Extension: 6742 resultType = Input->getType(); 6743 break; 6744 } 6745 if (resultType.isNull()) 6746 return ExprError(); 6747 6748 InputArg.release(); 6749 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, OpLoc)); 6750} 6751 6752Action::OwningExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 6753 UnaryOperator::Opcode Opc, 6754 ExprArg input) { 6755 Expr *Input = (Expr*)input.get(); 6756 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 6757 Opc != UnaryOperator::Extension) { 6758 // Find all of the overloaded operators visible from this 6759 // point. We perform both an operator-name lookup from the local 6760 // scope and an argument-dependent lookup based on the types of 6761 // the arguments. 6762 UnresolvedSet<16> Functions; 6763 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 6764 if (S && OverOp != OO_None) 6765 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 6766 Functions); 6767 6768 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, move(input)); 6769 } 6770 6771 return CreateBuiltinUnaryOp(OpLoc, Opc, move(input)); 6772} 6773 6774// Unary Operators. 'Tok' is the token for the operator. 6775Action::OwningExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 6776 tok::TokenKind Op, ExprArg input) { 6777 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), move(input)); 6778} 6779 6780/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 6781Sema::OwningExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 6782 SourceLocation LabLoc, 6783 IdentifierInfo *LabelII) { 6784 // Look up the record for this label identifier. 6785 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 6786 6787 // If we haven't seen this label yet, create a forward reference. It 6788 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 6789 if (LabelDecl == 0) 6790 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 6791 6792 // Create the AST node. The address of a label always has type 'void*'. 6793 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 6794 Context.getPointerType(Context.VoidTy))); 6795} 6796 6797Sema::OwningExprResult 6798Sema::ActOnStmtExpr(SourceLocation LPLoc, StmtArg substmt, 6799 SourceLocation RPLoc) { // "({..})" 6800 Stmt *SubStmt = static_cast<Stmt*>(substmt.get()); 6801 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 6802 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 6803 6804 bool isFileScope 6805 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 6806 if (isFileScope) 6807 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 6808 6809 // FIXME: there are a variety of strange constraints to enforce here, for 6810 // example, it is not possible to goto into a stmt expression apparently. 6811 // More semantic analysis is needed. 6812 6813 // If there are sub stmts in the compound stmt, take the type of the last one 6814 // as the type of the stmtexpr. 6815 QualType Ty = Context.VoidTy; 6816 6817 if (!Compound->body_empty()) { 6818 Stmt *LastStmt = Compound->body_back(); 6819 // If LastStmt is a label, skip down through into the body. 6820 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) 6821 LastStmt = Label->getSubStmt(); 6822 6823 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) 6824 Ty = LastExpr->getType(); 6825 } 6826 6827 // FIXME: Check that expression type is complete/non-abstract; statement 6828 // expressions are not lvalues. 6829 6830 substmt.release(); 6831 return Owned(new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc)); 6832} 6833 6834Sema::OwningExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 6835 TypeSourceInfo *TInfo, 6836 OffsetOfComponent *CompPtr, 6837 unsigned NumComponents, 6838 SourceLocation RParenLoc) { 6839 QualType ArgTy = TInfo->getType(); 6840 bool Dependent = ArgTy->isDependentType(); 6841 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 6842 6843 // We must have at least one component that refers to the type, and the first 6844 // one is known to be a field designator. Verify that the ArgTy represents 6845 // a struct/union/class. 6846 if (!Dependent && !ArgTy->isRecordType()) 6847 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 6848 << ArgTy << TypeRange); 6849 6850 // Type must be complete per C99 7.17p3 because a declaring a variable 6851 // with an incomplete type would be ill-formed. 6852 if (!Dependent 6853 && RequireCompleteType(BuiltinLoc, ArgTy, 6854 PDiag(diag::err_offsetof_incomplete_type) 6855 << TypeRange)) 6856 return ExprError(); 6857 6858 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 6859 // GCC extension, diagnose them. 6860 // FIXME: This diagnostic isn't actually visible because the location is in 6861 // a system header! 6862 if (NumComponents != 1) 6863 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 6864 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 6865 6866 bool DidWarnAboutNonPOD = false; 6867 QualType CurrentType = ArgTy; 6868 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 6869 llvm::SmallVector<OffsetOfNode, 4> Comps; 6870 llvm::SmallVector<Expr*, 4> Exprs; 6871 for (unsigned i = 0; i != NumComponents; ++i) { 6872 const OffsetOfComponent &OC = CompPtr[i]; 6873 if (OC.isBrackets) { 6874 // Offset of an array sub-field. TODO: Should we allow vector elements? 6875 if (!CurrentType->isDependentType()) { 6876 const ArrayType *AT = Context.getAsArrayType(CurrentType); 6877 if(!AT) 6878 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 6879 << CurrentType); 6880 CurrentType = AT->getElementType(); 6881 } else 6882 CurrentType = Context.DependentTy; 6883 6884 // The expression must be an integral expression. 6885 // FIXME: An integral constant expression? 6886 Expr *Idx = static_cast<Expr*>(OC.U.E); 6887 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 6888 !Idx->getType()->isIntegerType()) 6889 return ExprError(Diag(Idx->getLocStart(), 6890 diag::err_typecheck_subscript_not_integer) 6891 << Idx->getSourceRange()); 6892 6893 // Record this array index. 6894 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 6895 Exprs.push_back(Idx); 6896 continue; 6897 } 6898 6899 // Offset of a field. 6900 if (CurrentType->isDependentType()) { 6901 // We have the offset of a field, but we can't look into the dependent 6902 // type. Just record the identifier of the field. 6903 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 6904 CurrentType = Context.DependentTy; 6905 continue; 6906 } 6907 6908 // We need to have a complete type to look into. 6909 if (RequireCompleteType(OC.LocStart, CurrentType, 6910 diag::err_offsetof_incomplete_type)) 6911 return ExprError(); 6912 6913 // Look for the designated field. 6914 const RecordType *RC = CurrentType->getAs<RecordType>(); 6915 if (!RC) 6916 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 6917 << CurrentType); 6918 RecordDecl *RD = RC->getDecl(); 6919 6920 // C++ [lib.support.types]p5: 6921 // The macro offsetof accepts a restricted set of type arguments in this 6922 // International Standard. type shall be a POD structure or a POD union 6923 // (clause 9). 6924 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 6925 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 6926 DiagRuntimeBehavior(BuiltinLoc, 6927 PDiag(diag::warn_offsetof_non_pod_type) 6928 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 6929 << CurrentType)) 6930 DidWarnAboutNonPOD = true; 6931 } 6932 6933 // Look for the field. 6934 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 6935 LookupQualifiedName(R, RD); 6936 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 6937 if (!MemberDecl) 6938 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 6939 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 6940 OC.LocEnd)); 6941 6942 // C99 7.17p3: 6943 // (If the specified member is a bit-field, the behavior is undefined.) 6944 // 6945 // We diagnose this as an error. 6946 if (MemberDecl->getBitWidth()) { 6947 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 6948 << MemberDecl->getDeclName() 6949 << SourceRange(BuiltinLoc, RParenLoc); 6950 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 6951 return ExprError(); 6952 } 6953 6954 RecordDecl *Parent = MemberDecl->getParent(); 6955 bool AnonStructUnion = Parent->isAnonymousStructOrUnion(); 6956 if (AnonStructUnion) { 6957 do { 6958 Parent = cast<RecordDecl>(Parent->getParent()); 6959 } while (Parent->isAnonymousStructOrUnion()); 6960 } 6961 6962 // If the member was found in a base class, introduce OffsetOfNodes for 6963 // the base class indirections. 6964 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 6965 /*DetectVirtual=*/false); 6966 if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { 6967 CXXBasePath &Path = Paths.front(); 6968 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 6969 B != BEnd; ++B) 6970 Comps.push_back(OffsetOfNode(B->Base)); 6971 } 6972 6973 if (AnonStructUnion) { 6974 llvm::SmallVector<FieldDecl*, 4> Path; 6975 BuildAnonymousStructUnionMemberPath(MemberDecl, Path); 6976 unsigned n = Path.size(); 6977 for (int j = n - 1; j > -1; --j) 6978 Comps.push_back(OffsetOfNode(OC.LocStart, Path[j], OC.LocEnd)); 6979 } else { 6980 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 6981 } 6982 CurrentType = MemberDecl->getType().getNonReferenceType(); 6983 } 6984 6985 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 6986 TInfo, Comps.data(), Comps.size(), 6987 Exprs.data(), Exprs.size(), RParenLoc)); 6988} 6989 6990Sema::OwningExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 6991 SourceLocation BuiltinLoc, 6992 SourceLocation TypeLoc, 6993 TypeTy *argty, 6994 OffsetOfComponent *CompPtr, 6995 unsigned NumComponents, 6996 SourceLocation RPLoc) { 6997 6998 TypeSourceInfo *ArgTInfo; 6999 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 7000 if (ArgTy.isNull()) 7001 return ExprError(); 7002 7003 if (!ArgTInfo) 7004 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 7005 7006 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 7007 RPLoc); 7008} 7009 7010 7011Sema::OwningExprResult Sema::ActOnTypesCompatibleExpr(SourceLocation BuiltinLoc, 7012 TypeTy *arg1,TypeTy *arg2, 7013 SourceLocation RPLoc) { 7014 // FIXME: Preserve type source info. 7015 QualType argT1 = GetTypeFromParser(arg1); 7016 QualType argT2 = GetTypeFromParser(arg2); 7017 7018 assert((!argT1.isNull() && !argT2.isNull()) && "Missing type argument(s)"); 7019 7020 if (getLangOptions().CPlusPlus) { 7021 Diag(BuiltinLoc, diag::err_types_compatible_p_in_cplusplus) 7022 << SourceRange(BuiltinLoc, RPLoc); 7023 return ExprError(); 7024 } 7025 7026 return Owned(new (Context) TypesCompatibleExpr(Context.IntTy, BuiltinLoc, 7027 argT1, argT2, RPLoc)); 7028} 7029 7030Sema::OwningExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 7031 ExprArg cond, 7032 ExprArg expr1, ExprArg expr2, 7033 SourceLocation RPLoc) { 7034 Expr *CondExpr = static_cast<Expr*>(cond.get()); 7035 Expr *LHSExpr = static_cast<Expr*>(expr1.get()); 7036 Expr *RHSExpr = static_cast<Expr*>(expr2.get()); 7037 7038 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 7039 7040 QualType resType; 7041 bool ValueDependent = false; 7042 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 7043 resType = Context.DependentTy; 7044 ValueDependent = true; 7045 } else { 7046 // The conditional expression is required to be a constant expression. 7047 llvm::APSInt condEval(32); 7048 SourceLocation ExpLoc; 7049 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 7050 return ExprError(Diag(ExpLoc, 7051 diag::err_typecheck_choose_expr_requires_constant) 7052 << CondExpr->getSourceRange()); 7053 7054 // If the condition is > zero, then the AST type is the same as the LSHExpr. 7055 resType = condEval.getZExtValue() ? LHSExpr->getType() : RHSExpr->getType(); 7056 ValueDependent = condEval.getZExtValue() ? LHSExpr->isValueDependent() 7057 : RHSExpr->isValueDependent(); 7058 } 7059 7060 cond.release(); expr1.release(); expr2.release(); 7061 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 7062 resType, RPLoc, 7063 resType->isDependentType(), 7064 ValueDependent)); 7065} 7066 7067//===----------------------------------------------------------------------===// 7068// Clang Extensions. 7069//===----------------------------------------------------------------------===// 7070 7071/// ActOnBlockStart - This callback is invoked when a block literal is started. 7072void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 7073 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 7074 PushBlockScope(BlockScope, Block); 7075 CurContext->addDecl(Block); 7076 if (BlockScope) 7077 PushDeclContext(BlockScope, Block); 7078 else 7079 CurContext = Block; 7080} 7081 7082void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 7083 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 7084 BlockScopeInfo *CurBlock = getCurBlock(); 7085 7086 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 7087 CurBlock->TheDecl->setSignatureAsWritten(Sig); 7088 QualType T = Sig->getType(); 7089 7090 bool isVariadic; 7091 QualType RetTy; 7092 if (const FunctionType *Fn = T->getAs<FunctionType>()) { 7093 CurBlock->FunctionType = T; 7094 RetTy = Fn->getResultType(); 7095 isVariadic = 7096 !isa<FunctionProtoType>(Fn) || cast<FunctionProtoType>(Fn)->isVariadic(); 7097 } else { 7098 RetTy = T; 7099 isVariadic = false; 7100 } 7101 7102 CurBlock->TheDecl->setIsVariadic(isVariadic); 7103 7104 // Don't allow returning an array by value. 7105 if (RetTy->isArrayType()) { 7106 Diag(ParamInfo.getSourceRange().getBegin(), diag::err_block_returns_array); 7107 return; 7108 } 7109 7110 // Don't allow returning a objc interface by value. 7111 if (RetTy->isObjCObjectType()) { 7112 Diag(ParamInfo.getSourceRange().getBegin(), 7113 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 7114 return; 7115 } 7116 7117 // Context.DependentTy is used as a placeholder for a missing block 7118 // return type. TODO: what should we do with declarators like: 7119 // ^ * { ... } 7120 // If the answer is "apply template argument deduction".... 7121 if (RetTy != Context.DependentTy) 7122 CurBlock->ReturnType = RetTy; 7123 7124 // Push block parameters from the declarator if we had them. 7125 llvm::SmallVector<ParmVarDecl*, 8> Params; 7126 if (isa<FunctionProtoType>(T)) { 7127 FunctionProtoTypeLoc TL = cast<FunctionProtoTypeLoc>(Sig->getTypeLoc()); 7128 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 7129 ParmVarDecl *Param = TL.getArg(I); 7130 if (Param->getIdentifier() == 0 && 7131 !Param->isImplicit() && 7132 !Param->isInvalidDecl() && 7133 !getLangOptions().CPlusPlus) 7134 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 7135 Params.push_back(Param); 7136 } 7137 7138 // Fake up parameter variables if we have a typedef, like 7139 // ^ fntype { ... } 7140 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 7141 for (FunctionProtoType::arg_type_iterator 7142 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 7143 ParmVarDecl *Param = 7144 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 7145 ParamInfo.getSourceRange().getBegin(), 7146 *I); 7147 Params.push_back(Param); 7148 } 7149 } 7150 7151 // Set the parameters on the block decl. 7152 if (!Params.empty()) 7153 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 7154 7155 // Finally we can process decl attributes. 7156 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 7157 7158 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 7159 Diag(ParamInfo.getAttributes()->getLoc(), 7160 diag::warn_attribute_sentinel_not_variadic) << 1; 7161 // FIXME: remove the attribute. 7162 } 7163 7164 // Put the parameter variables in scope. We can bail out immediately 7165 // if we don't have any. 7166 if (Params.empty()) 7167 return; 7168 7169 bool ShouldCheckShadow = 7170 Diags.getDiagnosticLevel(diag::warn_decl_shadow) != Diagnostic::Ignored; 7171 7172 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 7173 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 7174 (*AI)->setOwningFunction(CurBlock->TheDecl); 7175 7176 // If this has an identifier, add it to the scope stack. 7177 if ((*AI)->getIdentifier()) { 7178 if (ShouldCheckShadow) 7179 CheckShadow(CurBlock->TheScope, *AI); 7180 7181 PushOnScopeChains(*AI, CurBlock->TheScope); 7182 } 7183 } 7184} 7185 7186/// ActOnBlockError - If there is an error parsing a block, this callback 7187/// is invoked to pop the information about the block from the action impl. 7188void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 7189 // Pop off CurBlock, handle nested blocks. 7190 PopDeclContext(); 7191 PopFunctionOrBlockScope(); 7192 // FIXME: Delete the ParmVarDecl objects as well??? 7193} 7194 7195/// ActOnBlockStmtExpr - This is called when the body of a block statement 7196/// literal was successfully completed. ^(int x){...} 7197Sema::OwningExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 7198 StmtArg body, Scope *CurScope) { 7199 // If blocks are disabled, emit an error. 7200 if (!LangOpts.Blocks) 7201 Diag(CaretLoc, diag::err_blocks_disable); 7202 7203 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 7204 7205 PopDeclContext(); 7206 7207 QualType RetTy = Context.VoidTy; 7208 if (!BSI->ReturnType.isNull()) 7209 RetTy = BSI->ReturnType; 7210 7211 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 7212 QualType BlockTy; 7213 7214 // If the user wrote a function type in some form, try to use that. 7215 if (!BSI->FunctionType.isNull()) { 7216 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 7217 7218 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 7219 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 7220 7221 // Turn protoless block types into nullary block types. 7222 if (isa<FunctionNoProtoType>(FTy)) { 7223 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7224 false, false, 0, 0, Ext); 7225 7226 // Otherwise, if we don't need to change anything about the function type, 7227 // preserve its sugar structure. 7228 } else if (FTy->getResultType() == RetTy && 7229 (!NoReturn || FTy->getNoReturnAttr())) { 7230 BlockTy = BSI->FunctionType; 7231 7232 // Otherwise, make the minimal modifications to the function type. 7233 } else { 7234 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 7235 BlockTy = Context.getFunctionType(RetTy, 7236 FPT->arg_type_begin(), 7237 FPT->getNumArgs(), 7238 FPT->isVariadic(), 7239 /*quals*/ 0, 7240 FPT->hasExceptionSpec(), 7241 FPT->hasAnyExceptionSpec(), 7242 FPT->getNumExceptions(), 7243 FPT->exception_begin(), 7244 Ext); 7245 } 7246 7247 // If we don't have a function type, just build one from nothing. 7248 } else { 7249 BlockTy = Context.getFunctionType(RetTy, 0, 0, false, 0, 7250 false, false, 0, 0, 7251 FunctionType::ExtInfo(NoReturn, 0, CC_Default)); 7252 } 7253 7254 // FIXME: Check that return/parameter types are complete/non-abstract 7255 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 7256 BSI->TheDecl->param_end()); 7257 BlockTy = Context.getBlockPointerType(BlockTy); 7258 7259 // If needed, diagnose invalid gotos and switches in the block. 7260 if (FunctionNeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 7261 DiagnoseInvalidJumps(static_cast<CompoundStmt*>(body.get())); 7262 7263 BSI->TheDecl->setBody(body.takeAs<CompoundStmt>()); 7264 7265 bool Good = true; 7266 // Check goto/label use. 7267 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 7268 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 7269 LabelStmt *L = I->second; 7270 7271 // Verify that we have no forward references left. If so, there was a goto 7272 // or address of a label taken, but no definition of it. 7273 if (L->getSubStmt() != 0) 7274 continue; 7275 7276 // Emit error. 7277 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 7278 Good = false; 7279 } 7280 if (!Good) { 7281 PopFunctionOrBlockScope(); 7282 return ExprError(); 7283 } 7284 7285 // Issue any analysis-based warnings. 7286 const sema::AnalysisBasedWarnings::Policy &WP = 7287 AnalysisWarnings.getDefaultPolicy(); 7288 AnalysisWarnings.IssueWarnings(WP, BSI->TheDecl, BlockTy); 7289 7290 Expr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 7291 BSI->hasBlockDeclRefExprs); 7292 PopFunctionOrBlockScope(); 7293 return Owned(Result); 7294} 7295 7296Sema::OwningExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 7297 ExprArg expr, TypeTy *type, 7298 SourceLocation RPLoc) { 7299 QualType T = GetTypeFromParser(type); 7300 Expr *E = static_cast<Expr*>(expr.get()); 7301 Expr *OrigExpr = E; 7302 7303 InitBuiltinVaListType(); 7304 7305 // Get the va_list type 7306 QualType VaListType = Context.getBuiltinVaListType(); 7307 if (VaListType->isArrayType()) { 7308 // Deal with implicit array decay; for example, on x86-64, 7309 // va_list is an array, but it's supposed to decay to 7310 // a pointer for va_arg. 7311 VaListType = Context.getArrayDecayedType(VaListType); 7312 // Make sure the input expression also decays appropriately. 7313 UsualUnaryConversions(E); 7314 } else { 7315 // Otherwise, the va_list argument must be an l-value because 7316 // it is modified by va_arg. 7317 if (!E->isTypeDependent() && 7318 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 7319 return ExprError(); 7320 } 7321 7322 if (!E->isTypeDependent() && 7323 !Context.hasSameType(VaListType, E->getType())) { 7324 return ExprError(Diag(E->getLocStart(), 7325 diag::err_first_argument_to_va_arg_not_of_type_va_list) 7326 << OrigExpr->getType() << E->getSourceRange()); 7327 } 7328 7329 // FIXME: Check that type is complete/non-abstract 7330 // FIXME: Warn if a non-POD type is passed in. 7331 7332 expr.release(); 7333 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, 7334 T.getNonLValueExprType(Context), 7335 RPLoc)); 7336} 7337 7338Sema::OwningExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 7339 // The type of __null will be int or long, depending on the size of 7340 // pointers on the target. 7341 QualType Ty; 7342 if (Context.Target.getPointerWidth(0) == Context.Target.getIntWidth()) 7343 Ty = Context.IntTy; 7344 else 7345 Ty = Context.LongTy; 7346 7347 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 7348} 7349 7350static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 7351 Expr *SrcExpr, FixItHint &Hint) { 7352 if (!SemaRef.getLangOptions().ObjC1) 7353 return; 7354 7355 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 7356 if (!PT) 7357 return; 7358 7359 // Check if the destination is of type 'id'. 7360 if (!PT->isObjCIdType()) { 7361 // Check if the destination is the 'NSString' interface. 7362 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 7363 if (!ID || !ID->getIdentifier()->isStr("NSString")) 7364 return; 7365 } 7366 7367 // Strip off any parens and casts. 7368 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 7369 if (!SL || SL->isWide()) 7370 return; 7371 7372 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 7373} 7374 7375bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 7376 SourceLocation Loc, 7377 QualType DstType, QualType SrcType, 7378 Expr *SrcExpr, AssignmentAction Action, 7379 bool *Complained) { 7380 if (Complained) 7381 *Complained = false; 7382 7383 // Decode the result (notice that AST's are still created for extensions). 7384 bool isInvalid = false; 7385 unsigned DiagKind; 7386 FixItHint Hint; 7387 7388 switch (ConvTy) { 7389 default: assert(0 && "Unknown conversion type"); 7390 case Compatible: return false; 7391 case PointerToInt: 7392 DiagKind = diag::ext_typecheck_convert_pointer_int; 7393 break; 7394 case IntToPointer: 7395 DiagKind = diag::ext_typecheck_convert_int_pointer; 7396 break; 7397 case IncompatiblePointer: 7398 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 7399 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 7400 break; 7401 case IncompatiblePointerSign: 7402 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 7403 break; 7404 case FunctionVoidPointer: 7405 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 7406 break; 7407 case CompatiblePointerDiscardsQualifiers: 7408 // If the qualifiers lost were because we were applying the 7409 // (deprecated) C++ conversion from a string literal to a char* 7410 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 7411 // Ideally, this check would be performed in 7412 // CheckPointerTypesForAssignment. However, that would require a 7413 // bit of refactoring (so that the second argument is an 7414 // expression, rather than a type), which should be done as part 7415 // of a larger effort to fix CheckPointerTypesForAssignment for 7416 // C++ semantics. 7417 if (getLangOptions().CPlusPlus && 7418 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 7419 return false; 7420 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 7421 break; 7422 case IncompatibleNestedPointerQualifiers: 7423 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 7424 break; 7425 case IntToBlockPointer: 7426 DiagKind = diag::err_int_to_block_pointer; 7427 break; 7428 case IncompatibleBlockPointer: 7429 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 7430 break; 7431 case IncompatibleObjCQualifiedId: 7432 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 7433 // it can give a more specific diagnostic. 7434 DiagKind = diag::warn_incompatible_qualified_id; 7435 break; 7436 case IncompatibleVectors: 7437 DiagKind = diag::warn_incompatible_vectors; 7438 break; 7439 case Incompatible: 7440 DiagKind = diag::err_typecheck_convert_incompatible; 7441 isInvalid = true; 7442 break; 7443 } 7444 7445 QualType FirstType, SecondType; 7446 switch (Action) { 7447 case AA_Assigning: 7448 case AA_Initializing: 7449 // The destination type comes first. 7450 FirstType = DstType; 7451 SecondType = SrcType; 7452 break; 7453 7454 case AA_Returning: 7455 case AA_Passing: 7456 case AA_Converting: 7457 case AA_Sending: 7458 case AA_Casting: 7459 // The source type comes first. 7460 FirstType = SrcType; 7461 SecondType = DstType; 7462 break; 7463 } 7464 7465 Diag(Loc, DiagKind) << FirstType << SecondType << Action 7466 << SrcExpr->getSourceRange() << Hint; 7467 if (Complained) 7468 *Complained = true; 7469 return isInvalid; 7470} 7471 7472bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 7473 llvm::APSInt ICEResult; 7474 if (E->isIntegerConstantExpr(ICEResult, Context)) { 7475 if (Result) 7476 *Result = ICEResult; 7477 return false; 7478 } 7479 7480 Expr::EvalResult EvalResult; 7481 7482 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 7483 EvalResult.HasSideEffects) { 7484 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 7485 7486 if (EvalResult.Diag) { 7487 // We only show the note if it's not the usual "invalid subexpression" 7488 // or if it's actually in a subexpression. 7489 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 7490 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 7491 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7492 } 7493 7494 return true; 7495 } 7496 7497 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 7498 E->getSourceRange(); 7499 7500 if (EvalResult.Diag && 7501 Diags.getDiagnosticLevel(diag::ext_expr_not_ice) != Diagnostic::Ignored) 7502 Diag(EvalResult.DiagLoc, EvalResult.Diag); 7503 7504 if (Result) 7505 *Result = EvalResult.Val.getInt(); 7506 return false; 7507} 7508 7509void 7510Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 7511 ExprEvalContexts.push_back( 7512 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 7513} 7514 7515void 7516Sema::PopExpressionEvaluationContext() { 7517 // Pop the current expression evaluation context off the stack. 7518 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 7519 ExprEvalContexts.pop_back(); 7520 7521 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 7522 if (Rec.PotentiallyReferenced) { 7523 // Mark any remaining declarations in the current position of the stack 7524 // as "referenced". If they were not meant to be referenced, semantic 7525 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 7526 for (PotentiallyReferencedDecls::iterator 7527 I = Rec.PotentiallyReferenced->begin(), 7528 IEnd = Rec.PotentiallyReferenced->end(); 7529 I != IEnd; ++I) 7530 MarkDeclarationReferenced(I->first, I->second); 7531 } 7532 7533 if (Rec.PotentiallyDiagnosed) { 7534 // Emit any pending diagnostics. 7535 for (PotentiallyEmittedDiagnostics::iterator 7536 I = Rec.PotentiallyDiagnosed->begin(), 7537 IEnd = Rec.PotentiallyDiagnosed->end(); 7538 I != IEnd; ++I) 7539 Diag(I->first, I->second); 7540 } 7541 } 7542 7543 // When are coming out of an unevaluated context, clear out any 7544 // temporaries that we may have created as part of the evaluation of 7545 // the expression in that context: they aren't relevant because they 7546 // will never be constructed. 7547 if (Rec.Context == Unevaluated && 7548 ExprTemporaries.size() > Rec.NumTemporaries) 7549 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 7550 ExprTemporaries.end()); 7551 7552 // Destroy the popped expression evaluation record. 7553 Rec.Destroy(); 7554} 7555 7556/// \brief Note that the given declaration was referenced in the source code. 7557/// 7558/// This routine should be invoke whenever a given declaration is referenced 7559/// in the source code, and where that reference occurred. If this declaration 7560/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 7561/// C99 6.9p3), then the declaration will be marked as used. 7562/// 7563/// \param Loc the location where the declaration was referenced. 7564/// 7565/// \param D the declaration that has been referenced by the source code. 7566void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 7567 assert(D && "No declaration?"); 7568 7569 if (D->isUsed(false)) 7570 return; 7571 7572 // Mark a parameter or variable declaration "used", regardless of whether we're in a 7573 // template or not. The reason for this is that unevaluated expressions 7574 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 7575 // -Wunused-parameters) 7576 if (isa<ParmVarDecl>(D) || 7577 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 7578 D->setUsed(true); 7579 return; 7580 } 7581 7582 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 7583 return; 7584 7585 // Do not mark anything as "used" within a dependent context; wait for 7586 // an instantiation. 7587 if (CurContext->isDependentContext()) 7588 return; 7589 7590 switch (ExprEvalContexts.back().Context) { 7591 case Unevaluated: 7592 // We are in an expression that is not potentially evaluated; do nothing. 7593 return; 7594 7595 case PotentiallyEvaluated: 7596 // We are in a potentially-evaluated expression, so this declaration is 7597 // "used"; handle this below. 7598 break; 7599 7600 case PotentiallyPotentiallyEvaluated: 7601 // We are in an expression that may be potentially evaluated; queue this 7602 // declaration reference until we know whether the expression is 7603 // potentially evaluated. 7604 ExprEvalContexts.back().addReferencedDecl(Loc, D); 7605 return; 7606 } 7607 7608 // Note that this declaration has been used. 7609 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 7610 unsigned TypeQuals; 7611 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 7612 if (!Constructor->isUsed(false)) 7613 DefineImplicitDefaultConstructor(Loc, Constructor); 7614 } else if (Constructor->isImplicit() && 7615 Constructor->isCopyConstructor(TypeQuals)) { 7616 if (!Constructor->isUsed(false)) 7617 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 7618 } 7619 7620 MarkVTableUsed(Loc, Constructor->getParent()); 7621 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 7622 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 7623 DefineImplicitDestructor(Loc, Destructor); 7624 if (Destructor->isVirtual()) 7625 MarkVTableUsed(Loc, Destructor->getParent()); 7626 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 7627 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 7628 MethodDecl->getOverloadedOperator() == OO_Equal) { 7629 if (!MethodDecl->isUsed(false)) 7630 DefineImplicitCopyAssignment(Loc, MethodDecl); 7631 } else if (MethodDecl->isVirtual()) 7632 MarkVTableUsed(Loc, MethodDecl->getParent()); 7633 } 7634 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 7635 // Implicit instantiation of function templates and member functions of 7636 // class templates. 7637 if (Function->isImplicitlyInstantiable()) { 7638 bool AlreadyInstantiated = false; 7639 if (FunctionTemplateSpecializationInfo *SpecInfo 7640 = Function->getTemplateSpecializationInfo()) { 7641 if (SpecInfo->getPointOfInstantiation().isInvalid()) 7642 SpecInfo->setPointOfInstantiation(Loc); 7643 else if (SpecInfo->getTemplateSpecializationKind() 7644 == TSK_ImplicitInstantiation) 7645 AlreadyInstantiated = true; 7646 } else if (MemberSpecializationInfo *MSInfo 7647 = Function->getMemberSpecializationInfo()) { 7648 if (MSInfo->getPointOfInstantiation().isInvalid()) 7649 MSInfo->setPointOfInstantiation(Loc); 7650 else if (MSInfo->getTemplateSpecializationKind() 7651 == TSK_ImplicitInstantiation) 7652 AlreadyInstantiated = true; 7653 } 7654 7655 if (!AlreadyInstantiated) { 7656 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 7657 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 7658 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 7659 Loc)); 7660 else 7661 PendingImplicitInstantiations.push_back(std::make_pair(Function, 7662 Loc)); 7663 } 7664 } 7665 7666 // FIXME: keep track of references to static functions 7667 Function->setUsed(true); 7668 7669 return; 7670 } 7671 7672 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 7673 // Implicit instantiation of static data members of class templates. 7674 if (Var->isStaticDataMember() && 7675 Var->getInstantiatedFromStaticDataMember()) { 7676 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 7677 assert(MSInfo && "Missing member specialization information?"); 7678 if (MSInfo->getPointOfInstantiation().isInvalid() && 7679 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 7680 MSInfo->setPointOfInstantiation(Loc); 7681 PendingImplicitInstantiations.push_back(std::make_pair(Var, Loc)); 7682 } 7683 } 7684 7685 // FIXME: keep track of references to static data? 7686 7687 D->setUsed(true); 7688 return; 7689 } 7690} 7691 7692namespace { 7693 // Mark all of the declarations referenced 7694 // FIXME: Not fully implemented yet! We need to have a better understanding 7695 // of when we're entering 7696 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 7697 Sema &S; 7698 SourceLocation Loc; 7699 7700 public: 7701 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 7702 7703 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 7704 7705 bool TraverseTemplateArgument(const TemplateArgument &Arg); 7706 bool TraverseRecordType(RecordType *T); 7707 }; 7708} 7709 7710bool MarkReferencedDecls::TraverseTemplateArgument( 7711 const TemplateArgument &Arg) { 7712 if (Arg.getKind() == TemplateArgument::Declaration) { 7713 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 7714 } 7715 7716 return Inherited::TraverseTemplateArgument(Arg); 7717} 7718 7719bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 7720 if (ClassTemplateSpecializationDecl *Spec 7721 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 7722 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 7723 return TraverseTemplateArguments(Args.getFlatArgumentList(), 7724 Args.flat_size()); 7725 } 7726 7727 return true; 7728} 7729 7730void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 7731 MarkReferencedDecls Marker(*this, Loc); 7732 Marker.TraverseType(Context.getCanonicalType(T)); 7733} 7734 7735/// \brief Emit a diagnostic that describes an effect on the run-time behavior 7736/// of the program being compiled. 7737/// 7738/// This routine emits the given diagnostic when the code currently being 7739/// type-checked is "potentially evaluated", meaning that there is a 7740/// possibility that the code will actually be executable. Code in sizeof() 7741/// expressions, code used only during overload resolution, etc., are not 7742/// potentially evaluated. This routine will suppress such diagnostics or, 7743/// in the absolutely nutty case of potentially potentially evaluated 7744/// expressions (C++ typeid), queue the diagnostic to potentially emit it 7745/// later. 7746/// 7747/// This routine should be used for all diagnostics that describe the run-time 7748/// behavior of a program, such as passing a non-POD value through an ellipsis. 7749/// Failure to do so will likely result in spurious diagnostics or failures 7750/// during overload resolution or within sizeof/alignof/typeof/typeid. 7751bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 7752 const PartialDiagnostic &PD) { 7753 switch (ExprEvalContexts.back().Context ) { 7754 case Unevaluated: 7755 // The argument will never be evaluated, so don't complain. 7756 break; 7757 7758 case PotentiallyEvaluated: 7759 Diag(Loc, PD); 7760 return true; 7761 7762 case PotentiallyPotentiallyEvaluated: 7763 ExprEvalContexts.back().addDiagnostic(Loc, PD); 7764 break; 7765 } 7766 7767 return false; 7768} 7769 7770bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 7771 CallExpr *CE, FunctionDecl *FD) { 7772 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 7773 return false; 7774 7775 PartialDiagnostic Note = 7776 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 7777 << FD->getDeclName() : PDiag(); 7778 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 7779 7780 if (RequireCompleteType(Loc, ReturnType, 7781 FD ? 7782 PDiag(diag::err_call_function_incomplete_return) 7783 << CE->getSourceRange() << FD->getDeclName() : 7784 PDiag(diag::err_call_incomplete_return) 7785 << CE->getSourceRange(), 7786 std::make_pair(NoteLoc, Note))) 7787 return true; 7788 7789 return false; 7790} 7791 7792// Diagnose the common s/=/==/ typo. Note that adding parentheses 7793// will prevent this condition from triggering, which is what we want. 7794void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 7795 SourceLocation Loc; 7796 7797 unsigned diagnostic = diag::warn_condition_is_assignment; 7798 7799 if (isa<BinaryOperator>(E)) { 7800 BinaryOperator *Op = cast<BinaryOperator>(E); 7801 if (Op->getOpcode() != BinaryOperator::Assign) 7802 return; 7803 7804 // Greylist some idioms by putting them into a warning subcategory. 7805 if (ObjCMessageExpr *ME 7806 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 7807 Selector Sel = ME->getSelector(); 7808 7809 // self = [<foo> init...] 7810 if (isSelfExpr(Op->getLHS()) 7811 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 7812 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7813 7814 // <foo> = [<bar> nextObject] 7815 else if (Sel.isUnarySelector() && 7816 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 7817 diagnostic = diag::warn_condition_is_idiomatic_assignment; 7818 } 7819 7820 Loc = Op->getOperatorLoc(); 7821 } else if (isa<CXXOperatorCallExpr>(E)) { 7822 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 7823 if (Op->getOperator() != OO_Equal) 7824 return; 7825 7826 Loc = Op->getOperatorLoc(); 7827 } else { 7828 // Not an assignment. 7829 return; 7830 } 7831 7832 SourceLocation Open = E->getSourceRange().getBegin(); 7833 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 7834 7835 Diag(Loc, diagnostic) << E->getSourceRange(); 7836 Diag(Loc, diag::note_condition_assign_to_comparison) 7837 << FixItHint::CreateReplacement(Loc, "=="); 7838 Diag(Loc, diag::note_condition_assign_silence) 7839 << FixItHint::CreateInsertion(Open, "(") 7840 << FixItHint::CreateInsertion(Close, ")"); 7841} 7842 7843bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 7844 DiagnoseAssignmentAsCondition(E); 7845 7846 if (!E->isTypeDependent()) { 7847 DefaultFunctionArrayLvalueConversion(E); 7848 7849 QualType T = E->getType(); 7850 7851 if (getLangOptions().CPlusPlus) { 7852 if (CheckCXXBooleanCondition(E)) // C++ 6.4p4 7853 return true; 7854 } else if (!T->isScalarType()) { // C99 6.8.4.1p1 7855 Diag(Loc, diag::err_typecheck_statement_requires_scalar) 7856 << T << E->getSourceRange(); 7857 return true; 7858 } 7859 } 7860 7861 return false; 7862} 7863 7864Sema::OwningExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 7865 ExprArg SubExpr) { 7866 Expr *Sub = SubExpr.takeAs<Expr>(); 7867 if (!Sub) 7868 return ExprError(); 7869 7870 if (CheckBooleanCondition(Sub, Loc)) 7871 return ExprError(); 7872 7873 return Owned(Sub); 7874} 7875