SemaExpr.cpp revision 5af1f066230be7571cffb408048479ad0f06f75e
1//===--- SemaExpr.cpp - Semantic Analysis for Expressions -----------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Initialization.h" 16#include "clang/Sema/Lookup.h" 17#include "clang/Sema/AnalysisBasedWarnings.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/CXXInheritance.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/EvaluatedExprVisitor.h" 23#include "clang/AST/Expr.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/ExprObjC.h" 26#include "clang/AST/RecursiveASTVisitor.h" 27#include "clang/AST/TypeLoc.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "clang/Basic/SourceManager.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Lex/LiteralSupport.h" 32#include "clang/Lex/Preprocessor.h" 33#include "clang/Sema/DeclSpec.h" 34#include "clang/Sema/Designator.h" 35#include "clang/Sema/Scope.h" 36#include "clang/Sema/ScopeInfo.h" 37#include "clang/Sema/ParsedTemplate.h" 38#include "clang/Sema/Template.h" 39using namespace clang; 40using namespace sema; 41 42 43/// \brief Determine whether the use of this declaration is valid, and 44/// emit any corresponding diagnostics. 45/// 46/// This routine diagnoses various problems with referencing 47/// declarations that can occur when using a declaration. For example, 48/// it might warn if a deprecated or unavailable declaration is being 49/// used, or produce an error (and return true) if a C++0x deleted 50/// function is being used. 51/// 52/// If IgnoreDeprecated is set to true, this should not warn about deprecated 53/// decls. 54/// 55/// \returns true if there was an error (this declaration cannot be 56/// referenced), false otherwise. 57/// 58bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc, 59 bool UnknownObjCClass) { 60 if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { 61 // If there were any diagnostics suppressed by template argument deduction, 62 // emit them now. 63 llvm::DenseMap<Decl *, llvm::SmallVector<PartialDiagnosticAt, 1> >::iterator 64 Pos = SuppressedDiagnostics.find(D->getCanonicalDecl()); 65 if (Pos != SuppressedDiagnostics.end()) { 66 llvm::SmallVectorImpl<PartialDiagnosticAt> &Suppressed = Pos->second; 67 for (unsigned I = 0, N = Suppressed.size(); I != N; ++I) 68 Diag(Suppressed[I].first, Suppressed[I].second); 69 70 // Clear out the list of suppressed diagnostics, so that we don't emit 71 // them again for this specialization. However, we don't remove this 72 // entry from the table, because we want to avoid ever emitting these 73 // diagnostics again. 74 Suppressed.clear(); 75 } 76 } 77 78 // See if the decl is deprecated. 79 if (const DeprecatedAttr *DA = D->getAttr<DeprecatedAttr>()) 80 EmitDeprecationWarning(D, DA->getMessage(), Loc, UnknownObjCClass); 81 82 // See if the decl is unavailable 83 if (const UnavailableAttr *UA = D->getAttr<UnavailableAttr>()) { 84 if (UA->getMessage().empty()) { 85 if (!UnknownObjCClass) 86 Diag(Loc, diag::err_unavailable) << D->getDeclName(); 87 else 88 Diag(Loc, diag::warn_unavailable_fwdclass_message) 89 << D->getDeclName(); 90 } 91 else 92 Diag(Loc, diag::err_unavailable_message) 93 << D->getDeclName() << UA->getMessage(); 94 Diag(D->getLocation(), diag::note_unavailable_here) << 0; 95 } 96 97 // See if this is a deleted function. 98 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 99 if (FD->isDeleted()) { 100 Diag(Loc, diag::err_deleted_function_use); 101 Diag(D->getLocation(), diag::note_unavailable_here) << true; 102 return true; 103 } 104 } 105 106 // Warn if this is used but marked unused. 107 if (D->hasAttr<UnusedAttr>()) 108 Diag(Loc, diag::warn_used_but_marked_unused) << D->getDeclName(); 109 110 return false; 111} 112 113/// DiagnoseSentinelCalls - This routine checks on method dispatch calls 114/// (and other functions in future), which have been declared with sentinel 115/// attribute. It warns if call does not have the sentinel argument. 116/// 117void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, 118 Expr **Args, unsigned NumArgs) { 119 const SentinelAttr *attr = D->getAttr<SentinelAttr>(); 120 if (!attr) 121 return; 122 123 // FIXME: In C++0x, if any of the arguments are parameter pack 124 // expansions, we can't check for the sentinel now. 125 int sentinelPos = attr->getSentinel(); 126 int nullPos = attr->getNullPos(); 127 128 // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common 129 // base class. Then we won't be needing two versions of the same code. 130 unsigned int i = 0; 131 bool warnNotEnoughArgs = false; 132 int isMethod = 0; 133 if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { 134 // skip over named parameters. 135 ObjCMethodDecl::param_iterator P, E = MD->param_end(); 136 for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { 137 if (nullPos) 138 --nullPos; 139 else 140 ++i; 141 } 142 warnNotEnoughArgs = (P != E || i >= NumArgs); 143 isMethod = 1; 144 } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 145 // skip over named parameters. 146 ObjCMethodDecl::param_iterator P, E = FD->param_end(); 147 for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { 148 if (nullPos) 149 --nullPos; 150 else 151 ++i; 152 } 153 warnNotEnoughArgs = (P != E || i >= NumArgs); 154 } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { 155 // block or function pointer call. 156 QualType Ty = V->getType(); 157 if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { 158 const FunctionType *FT = Ty->isFunctionPointerType() 159 ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() 160 : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); 161 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { 162 unsigned NumArgsInProto = Proto->getNumArgs(); 163 unsigned k; 164 for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { 165 if (nullPos) 166 --nullPos; 167 else 168 ++i; 169 } 170 warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); 171 } 172 if (Ty->isBlockPointerType()) 173 isMethod = 2; 174 } else 175 return; 176 } else 177 return; 178 179 if (warnNotEnoughArgs) { 180 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 181 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 182 return; 183 } 184 int sentinel = i; 185 while (sentinelPos > 0 && i < NumArgs-1) { 186 --sentinelPos; 187 ++i; 188 } 189 if (sentinelPos > 0) { 190 Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); 191 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 192 return; 193 } 194 while (i < NumArgs-1) { 195 ++i; 196 ++sentinel; 197 } 198 Expr *sentinelExpr = Args[sentinel]; 199 if (!sentinelExpr) return; 200 if (sentinelExpr->isTypeDependent()) return; 201 if (sentinelExpr->isValueDependent()) return; 202 203 // nullptr_t is always treated as null. 204 if (sentinelExpr->getType()->isNullPtrType()) return; 205 206 if (sentinelExpr->getType()->isAnyPointerType() && 207 sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, 208 Expr::NPC_ValueDependentIsNull)) 209 return; 210 211 // Unfortunately, __null has type 'int'. 212 if (isa<GNUNullExpr>(sentinelExpr)) return; 213 214 Diag(Loc, diag::warn_missing_sentinel) << isMethod; 215 Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; 216} 217 218SourceRange Sema::getExprRange(ExprTy *E) const { 219 Expr *Ex = (Expr *)E; 220 return Ex? Ex->getSourceRange() : SourceRange(); 221} 222 223//===----------------------------------------------------------------------===// 224// Standard Promotions and Conversions 225//===----------------------------------------------------------------------===// 226 227/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). 228void Sema::DefaultFunctionArrayConversion(Expr *&E) { 229 QualType Ty = E->getType(); 230 assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); 231 232 if (Ty->isFunctionType()) 233 ImpCastExprToType(E, Context.getPointerType(Ty), 234 CK_FunctionToPointerDecay); 235 else if (Ty->isArrayType()) { 236 // In C90 mode, arrays only promote to pointers if the array expression is 237 // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has 238 // type 'array of type' is converted to an expression that has type 'pointer 239 // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression 240 // that has type 'array of type' ...". The relevant change is "an lvalue" 241 // (C90) to "an expression" (C99). 242 // 243 // C++ 4.2p1: 244 // An lvalue or rvalue of type "array of N T" or "array of unknown bound of 245 // T" can be converted to an rvalue of type "pointer to T". 246 // 247 if (getLangOptions().C99 || getLangOptions().CPlusPlus || E->isLValue()) 248 ImpCastExprToType(E, Context.getArrayDecayedType(Ty), 249 CK_ArrayToPointerDecay); 250 } 251} 252 253void Sema::DefaultLvalueConversion(Expr *&E) { 254 // C++ [conv.lval]p1: 255 // A glvalue of a non-function, non-array type T can be 256 // converted to a prvalue. 257 if (!E->isGLValue()) return; 258 259 QualType T = E->getType(); 260 assert(!T.isNull() && "r-value conversion on typeless expression?"); 261 262 // Create a load out of an ObjCProperty l-value, if necessary. 263 if (E->getObjectKind() == OK_ObjCProperty) { 264 ConvertPropertyForRValue(E); 265 if (!E->isGLValue()) 266 return; 267 } 268 269 // We don't want to throw lvalue-to-rvalue casts on top of 270 // expressions of certain types in C++. 271 if (getLangOptions().CPlusPlus && 272 (E->getType() == Context.OverloadTy || 273 T->isDependentType() || 274 T->isRecordType())) 275 return; 276 277 // The C standard is actually really unclear on this point, and 278 // DR106 tells us what the result should be but not why. It's 279 // generally best to say that void types just doesn't undergo 280 // lvalue-to-rvalue at all. Note that expressions of unqualified 281 // 'void' type are never l-values, but qualified void can be. 282 if (T->isVoidType()) 283 return; 284 285 // C++ [conv.lval]p1: 286 // [...] If T is a non-class type, the type of the prvalue is the 287 // cv-unqualified version of T. Otherwise, the type of the 288 // rvalue is T. 289 // 290 // C99 6.3.2.1p2: 291 // If the lvalue has qualified type, the value has the unqualified 292 // version of the type of the lvalue; otherwise, the value has the 293 // type of the lvalue. 294 if (T.hasQualifiers()) 295 T = T.getUnqualifiedType(); 296 297 E = ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, 298 E, 0, VK_RValue); 299} 300 301void Sema::DefaultFunctionArrayLvalueConversion(Expr *&E) { 302 DefaultFunctionArrayConversion(E); 303 DefaultLvalueConversion(E); 304} 305 306 307/// UsualUnaryConversions - Performs various conversions that are common to most 308/// operators (C99 6.3). The conversions of array and function types are 309/// sometimes surpressed. For example, the array->pointer conversion doesn't 310/// apply if the array is an argument to the sizeof or address (&) operators. 311/// In these instances, this routine should *not* be called. 312Expr *Sema::UsualUnaryConversions(Expr *&E) { 313 // First, convert to an r-value. 314 DefaultFunctionArrayLvalueConversion(E); 315 316 QualType Ty = E->getType(); 317 assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); 318 319 // Try to perform integral promotions if the object has a theoretically 320 // promotable type. 321 if (Ty->isIntegralOrUnscopedEnumerationType()) { 322 // C99 6.3.1.1p2: 323 // 324 // The following may be used in an expression wherever an int or 325 // unsigned int may be used: 326 // - an object or expression with an integer type whose integer 327 // conversion rank is less than or equal to the rank of int 328 // and unsigned int. 329 // - A bit-field of type _Bool, int, signed int, or unsigned int. 330 // 331 // If an int can represent all values of the original type, the 332 // value is converted to an int; otherwise, it is converted to an 333 // unsigned int. These are called the integer promotions. All 334 // other types are unchanged by the integer promotions. 335 336 QualType PTy = Context.isPromotableBitField(E); 337 if (!PTy.isNull()) { 338 ImpCastExprToType(E, PTy, CK_IntegralCast); 339 return E; 340 } 341 if (Ty->isPromotableIntegerType()) { 342 QualType PT = Context.getPromotedIntegerType(Ty); 343 ImpCastExprToType(E, PT, CK_IntegralCast); 344 return E; 345 } 346 } 347 348 return E; 349} 350 351/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that 352/// do not have a prototype. Arguments that have type float are promoted to 353/// double. All other argument types are converted by UsualUnaryConversions(). 354void Sema::DefaultArgumentPromotion(Expr *&Expr) { 355 QualType Ty = Expr->getType(); 356 assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); 357 358 UsualUnaryConversions(Expr); 359 360 // If this is a 'float' (CVR qualified or typedef) promote to double. 361 if (Ty->isSpecificBuiltinType(BuiltinType::Float)) 362 return ImpCastExprToType(Expr, Context.DoubleTy, CK_FloatingCast); 363} 364 365/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but 366/// will warn if the resulting type is not a POD type, and rejects ObjC 367/// interfaces passed by value. This returns true if the argument type is 368/// completely illegal. 369bool Sema::DefaultVariadicArgumentPromotion(Expr *&Expr, VariadicCallType CT, 370 FunctionDecl *FDecl) { 371 DefaultArgumentPromotion(Expr); 372 373 // __builtin_va_start takes the second argument as a "varargs" argument, but 374 // it doesn't actually do anything with it. It doesn't need to be non-pod 375 // etc. 376 if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) 377 return false; 378 379 if (Expr->getType()->isObjCObjectType() && 380 DiagRuntimeBehavior(Expr->getLocStart(), 381 PDiag(diag::err_cannot_pass_objc_interface_to_vararg) 382 << Expr->getType() << CT)) 383 return true; 384 385 if (!Expr->getType()->isPODType() && 386 DiagRuntimeBehavior(Expr->getLocStart(), 387 PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) 388 << Expr->getType() << CT)) 389 return true; 390 391 return false; 392} 393 394/// UsualArithmeticConversions - Performs various conversions that are common to 395/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this 396/// routine returns the first non-arithmetic type found. The client is 397/// responsible for emitting appropriate error diagnostics. 398/// FIXME: verify the conversion rules for "complex int" are consistent with 399/// GCC. 400QualType Sema::UsualArithmeticConversions(Expr *&lhsExpr, Expr *&rhsExpr, 401 bool isCompAssign) { 402 if (!isCompAssign) 403 UsualUnaryConversions(lhsExpr); 404 405 UsualUnaryConversions(rhsExpr); 406 407 // For conversion purposes, we ignore any qualifiers. 408 // For example, "const float" and "float" are equivalent. 409 QualType lhs = 410 Context.getCanonicalType(lhsExpr->getType()).getUnqualifiedType(); 411 QualType rhs = 412 Context.getCanonicalType(rhsExpr->getType()).getUnqualifiedType(); 413 414 // If both types are identical, no conversion is needed. 415 if (lhs == rhs) 416 return lhs; 417 418 // If either side is a non-arithmetic type (e.g. a pointer), we are done. 419 // The caller can deal with this (e.g. pointer + int). 420 if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) 421 return lhs; 422 423 // Apply unary and bitfield promotions to the LHS's type. 424 QualType lhs_unpromoted = lhs; 425 if (lhs->isPromotableIntegerType()) 426 lhs = Context.getPromotedIntegerType(lhs); 427 QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr); 428 if (!LHSBitfieldPromoteTy.isNull()) 429 lhs = LHSBitfieldPromoteTy; 430 if (lhs != lhs_unpromoted && !isCompAssign) 431 ImpCastExprToType(lhsExpr, lhs, CK_IntegralCast); 432 433 // If both types are identical, no conversion is needed. 434 if (lhs == rhs) 435 return lhs; 436 437 // At this point, we have two different arithmetic types. 438 439 // Handle complex types first (C99 6.3.1.8p1). 440 bool LHSComplexFloat = lhs->isComplexType(); 441 bool RHSComplexFloat = rhs->isComplexType(); 442 if (LHSComplexFloat || RHSComplexFloat) { 443 // if we have an integer operand, the result is the complex type. 444 445 if (!RHSComplexFloat && !rhs->isRealFloatingType()) { 446 if (rhs->isIntegerType()) { 447 QualType fp = cast<ComplexType>(lhs)->getElementType(); 448 ImpCastExprToType(rhsExpr, fp, CK_IntegralToFloating); 449 ImpCastExprToType(rhsExpr, lhs, CK_FloatingRealToComplex); 450 } else { 451 assert(rhs->isComplexIntegerType()); 452 ImpCastExprToType(rhsExpr, lhs, CK_IntegralComplexToFloatingComplex); 453 } 454 return lhs; 455 } 456 457 if (!LHSComplexFloat && !lhs->isRealFloatingType()) { 458 if (!isCompAssign) { 459 // int -> float -> _Complex float 460 if (lhs->isIntegerType()) { 461 QualType fp = cast<ComplexType>(rhs)->getElementType(); 462 ImpCastExprToType(lhsExpr, fp, CK_IntegralToFloating); 463 ImpCastExprToType(lhsExpr, rhs, CK_FloatingRealToComplex); 464 } else { 465 assert(lhs->isComplexIntegerType()); 466 ImpCastExprToType(lhsExpr, rhs, CK_IntegralComplexToFloatingComplex); 467 } 468 } 469 return rhs; 470 } 471 472 // This handles complex/complex, complex/float, or float/complex. 473 // When both operands are complex, the shorter operand is converted to the 474 // type of the longer, and that is the type of the result. This corresponds 475 // to what is done when combining two real floating-point operands. 476 // The fun begins when size promotion occur across type domains. 477 // From H&S 6.3.4: When one operand is complex and the other is a real 478 // floating-point type, the less precise type is converted, within it's 479 // real or complex domain, to the precision of the other type. For example, 480 // when combining a "long double" with a "double _Complex", the 481 // "double _Complex" is promoted to "long double _Complex". 482 int order = Context.getFloatingTypeOrder(lhs, rhs); 483 484 // If both are complex, just cast to the more precise type. 485 if (LHSComplexFloat && RHSComplexFloat) { 486 if (order > 0) { 487 // _Complex float -> _Complex double 488 ImpCastExprToType(rhsExpr, lhs, CK_FloatingComplexCast); 489 return lhs; 490 491 } else if (order < 0) { 492 // _Complex float -> _Complex double 493 if (!isCompAssign) 494 ImpCastExprToType(lhsExpr, rhs, CK_FloatingComplexCast); 495 return rhs; 496 } 497 return lhs; 498 } 499 500 // If just the LHS is complex, the RHS needs to be converted, 501 // and the LHS might need to be promoted. 502 if (LHSComplexFloat) { 503 if (order > 0) { // LHS is wider 504 // float -> _Complex double 505 QualType fp = cast<ComplexType>(lhs)->getElementType(); 506 ImpCastExprToType(rhsExpr, fp, CK_FloatingCast); 507 ImpCastExprToType(rhsExpr, lhs, CK_FloatingRealToComplex); 508 return lhs; 509 } 510 511 // RHS is at least as wide. Find its corresponding complex type. 512 QualType result = (order == 0 ? lhs : Context.getComplexType(rhs)); 513 514 // double -> _Complex double 515 ImpCastExprToType(rhsExpr, result, CK_FloatingRealToComplex); 516 517 // _Complex float -> _Complex double 518 if (!isCompAssign && order < 0) 519 ImpCastExprToType(lhsExpr, result, CK_FloatingComplexCast); 520 521 return result; 522 } 523 524 // Just the RHS is complex, so the LHS needs to be converted 525 // and the RHS might need to be promoted. 526 assert(RHSComplexFloat); 527 528 if (order < 0) { // RHS is wider 529 // float -> _Complex double 530 if (!isCompAssign) { 531 QualType fp = cast<ComplexType>(rhs)->getElementType(); 532 ImpCastExprToType(lhsExpr, fp, CK_FloatingCast); 533 ImpCastExprToType(lhsExpr, rhs, CK_FloatingRealToComplex); 534 } 535 return rhs; 536 } 537 538 // LHS is at least as wide. Find its corresponding complex type. 539 QualType result = (order == 0 ? rhs : Context.getComplexType(lhs)); 540 541 // double -> _Complex double 542 if (!isCompAssign) 543 ImpCastExprToType(lhsExpr, result, CK_FloatingRealToComplex); 544 545 // _Complex float -> _Complex double 546 if (order > 0) 547 ImpCastExprToType(rhsExpr, result, CK_FloatingComplexCast); 548 549 return result; 550 } 551 552 // Now handle "real" floating types (i.e. float, double, long double). 553 bool LHSFloat = lhs->isRealFloatingType(); 554 bool RHSFloat = rhs->isRealFloatingType(); 555 if (LHSFloat || RHSFloat) { 556 // If we have two real floating types, convert the smaller operand 557 // to the bigger result. 558 if (LHSFloat && RHSFloat) { 559 int order = Context.getFloatingTypeOrder(lhs, rhs); 560 if (order > 0) { 561 ImpCastExprToType(rhsExpr, lhs, CK_FloatingCast); 562 return lhs; 563 } 564 565 assert(order < 0 && "illegal float comparison"); 566 if (!isCompAssign) 567 ImpCastExprToType(lhsExpr, rhs, CK_FloatingCast); 568 return rhs; 569 } 570 571 // If we have an integer operand, the result is the real floating type. 572 if (LHSFloat) { 573 if (rhs->isIntegerType()) { 574 // Convert rhs to the lhs floating point type. 575 ImpCastExprToType(rhsExpr, lhs, CK_IntegralToFloating); 576 return lhs; 577 } 578 579 // Convert both sides to the appropriate complex float. 580 assert(rhs->isComplexIntegerType()); 581 QualType result = Context.getComplexType(lhs); 582 583 // _Complex int -> _Complex float 584 ImpCastExprToType(rhsExpr, result, CK_IntegralComplexToFloatingComplex); 585 586 // float -> _Complex float 587 if (!isCompAssign) 588 ImpCastExprToType(lhsExpr, result, CK_FloatingRealToComplex); 589 590 return result; 591 } 592 593 assert(RHSFloat); 594 if (lhs->isIntegerType()) { 595 // Convert lhs to the rhs floating point type. 596 if (!isCompAssign) 597 ImpCastExprToType(lhsExpr, rhs, CK_IntegralToFloating); 598 return rhs; 599 } 600 601 // Convert both sides to the appropriate complex float. 602 assert(lhs->isComplexIntegerType()); 603 QualType result = Context.getComplexType(rhs); 604 605 // _Complex int -> _Complex float 606 if (!isCompAssign) 607 ImpCastExprToType(lhsExpr, result, CK_IntegralComplexToFloatingComplex); 608 609 // float -> _Complex float 610 ImpCastExprToType(rhsExpr, result, CK_FloatingRealToComplex); 611 612 return result; 613 } 614 615 // Handle GCC complex int extension. 616 // FIXME: if the operands are (int, _Complex long), we currently 617 // don't promote the complex. Also, signedness? 618 const ComplexType *lhsComplexInt = lhs->getAsComplexIntegerType(); 619 const ComplexType *rhsComplexInt = rhs->getAsComplexIntegerType(); 620 if (lhsComplexInt && rhsComplexInt) { 621 int order = Context.getIntegerTypeOrder(lhsComplexInt->getElementType(), 622 rhsComplexInt->getElementType()); 623 assert(order && "inequal types with equal element ordering"); 624 if (order > 0) { 625 // _Complex int -> _Complex long 626 ImpCastExprToType(rhsExpr, lhs, CK_IntegralComplexCast); 627 return lhs; 628 } 629 630 if (!isCompAssign) 631 ImpCastExprToType(lhsExpr, rhs, CK_IntegralComplexCast); 632 return rhs; 633 } else if (lhsComplexInt) { 634 // int -> _Complex int 635 ImpCastExprToType(rhsExpr, lhs, CK_IntegralRealToComplex); 636 return lhs; 637 } else if (rhsComplexInt) { 638 // int -> _Complex int 639 if (!isCompAssign) 640 ImpCastExprToType(lhsExpr, rhs, CK_IntegralRealToComplex); 641 return rhs; 642 } 643 644 // Finally, we have two differing integer types. 645 // The rules for this case are in C99 6.3.1.8 646 int compare = Context.getIntegerTypeOrder(lhs, rhs); 647 bool lhsSigned = lhs->hasSignedIntegerRepresentation(), 648 rhsSigned = rhs->hasSignedIntegerRepresentation(); 649 if (lhsSigned == rhsSigned) { 650 // Same signedness; use the higher-ranked type 651 if (compare >= 0) { 652 ImpCastExprToType(rhsExpr, lhs, CK_IntegralCast); 653 return lhs; 654 } else if (!isCompAssign) 655 ImpCastExprToType(lhsExpr, rhs, CK_IntegralCast); 656 return rhs; 657 } else if (compare != (lhsSigned ? 1 : -1)) { 658 // The unsigned type has greater than or equal rank to the 659 // signed type, so use the unsigned type 660 if (rhsSigned) { 661 ImpCastExprToType(rhsExpr, lhs, CK_IntegralCast); 662 return lhs; 663 } else if (!isCompAssign) 664 ImpCastExprToType(lhsExpr, rhs, CK_IntegralCast); 665 return rhs; 666 } else if (Context.getIntWidth(lhs) != Context.getIntWidth(rhs)) { 667 // The two types are different widths; if we are here, that 668 // means the signed type is larger than the unsigned type, so 669 // use the signed type. 670 if (lhsSigned) { 671 ImpCastExprToType(rhsExpr, lhs, CK_IntegralCast); 672 return lhs; 673 } else if (!isCompAssign) 674 ImpCastExprToType(lhsExpr, rhs, CK_IntegralCast); 675 return rhs; 676 } else { 677 // The signed type is higher-ranked than the unsigned type, 678 // but isn't actually any bigger (like unsigned int and long 679 // on most 32-bit systems). Use the unsigned type corresponding 680 // to the signed type. 681 QualType result = 682 Context.getCorrespondingUnsignedType(lhsSigned ? lhs : rhs); 683 ImpCastExprToType(rhsExpr, result, CK_IntegralCast); 684 if (!isCompAssign) 685 ImpCastExprToType(lhsExpr, result, CK_IntegralCast); 686 return result; 687 } 688} 689 690//===----------------------------------------------------------------------===// 691// Semantic Analysis for various Expression Types 692//===----------------------------------------------------------------------===// 693 694 695/// ActOnStringLiteral - The specified tokens were lexed as pasted string 696/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string 697/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from 698/// multiple tokens. However, the common case is that StringToks points to one 699/// string. 700/// 701ExprResult 702Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { 703 assert(NumStringToks && "Must have at least one string!"); 704 705 StringLiteralParser Literal(StringToks, NumStringToks, PP); 706 if (Literal.hadError) 707 return ExprError(); 708 709 llvm::SmallVector<SourceLocation, 4> StringTokLocs; 710 for (unsigned i = 0; i != NumStringToks; ++i) 711 StringTokLocs.push_back(StringToks[i].getLocation()); 712 713 QualType StrTy = Context.CharTy; 714 if (Literal.AnyWide) StrTy = Context.getWCharType(); 715 if (Literal.Pascal) StrTy = Context.UnsignedCharTy; 716 717 // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). 718 if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) 719 StrTy.addConst(); 720 721 // Get an array type for the string, according to C99 6.4.5. This includes 722 // the nul terminator character as well as the string length for pascal 723 // strings. 724 StrTy = Context.getConstantArrayType(StrTy, 725 llvm::APInt(32, Literal.GetNumStringChars()+1), 726 ArrayType::Normal, 0); 727 728 // Pass &StringTokLocs[0], StringTokLocs.size() to factory! 729 return Owned(StringLiteral::Create(Context, Literal.GetString(), 730 Literal.GetStringLength(), 731 Literal.AnyWide, StrTy, 732 &StringTokLocs[0], 733 StringTokLocs.size())); 734} 735 736/// ShouldSnapshotBlockValueReference - Return true if a reference inside of 737/// CurBlock to VD should cause it to be snapshotted (as we do for auto 738/// variables defined outside the block) or false if this is not needed (e.g. 739/// for values inside the block or for globals). 740/// 741/// This also keeps the 'hasBlockDeclRefExprs' in the BlockScopeInfo records 742/// up-to-date. 743/// 744static bool ShouldSnapshotBlockValueReference(Sema &S, BlockScopeInfo *CurBlock, 745 ValueDecl *VD) { 746 // If the value is defined inside the block, we couldn't snapshot it even if 747 // we wanted to. 748 if (CurBlock->TheDecl == VD->getDeclContext()) 749 return false; 750 751 // If this is an enum constant or function, it is constant, don't snapshot. 752 if (isa<EnumConstantDecl>(VD) || isa<FunctionDecl>(VD)) 753 return false; 754 755 // If this is a reference to an extern, static, or global variable, no need to 756 // snapshot it. 757 // FIXME: What about 'const' variables in C++? 758 if (const VarDecl *Var = dyn_cast<VarDecl>(VD)) 759 if (!Var->hasLocalStorage()) 760 return false; 761 762 // Blocks that have these can't be constant. 763 CurBlock->hasBlockDeclRefExprs = true; 764 765 // If we have nested blocks, the decl may be declared in an outer block (in 766 // which case that outer block doesn't get "hasBlockDeclRefExprs") or it may 767 // be defined outside all of the current blocks (in which case the blocks do 768 // all get the bit). Walk the nesting chain. 769 for (unsigned I = S.FunctionScopes.size() - 1; I; --I) { 770 BlockScopeInfo *NextBlock = dyn_cast<BlockScopeInfo>(S.FunctionScopes[I]); 771 772 if (!NextBlock) 773 continue; 774 775 // If we found the defining block for the variable, don't mark the block as 776 // having a reference outside it. 777 if (NextBlock->TheDecl == VD->getDeclContext()) 778 break; 779 780 // Otherwise, the DeclRef from the inner block causes the outer one to need 781 // a snapshot as well. 782 NextBlock->hasBlockDeclRefExprs = true; 783 } 784 785 return true; 786} 787 788 789ExprResult 790Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, 791 SourceLocation Loc, const CXXScopeSpec *SS) { 792 DeclarationNameInfo NameInfo(D->getDeclName(), Loc); 793 return BuildDeclRefExpr(D, Ty, VK, NameInfo, SS); 794} 795 796/// BuildDeclRefExpr - Build a DeclRefExpr. 797ExprResult 798Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, 799 ExprValueKind VK, 800 const DeclarationNameInfo &NameInfo, 801 const CXXScopeSpec *SS) { 802 if (Context.getCanonicalType(Ty) == Context.UndeducedAutoTy) { 803 Diag(NameInfo.getLoc(), 804 diag::err_auto_variable_cannot_appear_in_own_initializer) 805 << D->getDeclName(); 806 return ExprError(); 807 } 808 809 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 810 if (isa<NonTypeTemplateParmDecl>(VD)) { 811 // Non-type template parameters can be referenced anywhere they are 812 // visible. 813 Ty = Ty.getNonLValueExprType(Context); 814 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) { 815 if (const FunctionDecl *FD = MD->getParent()->isLocalClass()) { 816 if (VD->hasLocalStorage() && VD->getDeclContext() != CurContext) { 817 Diag(NameInfo.getLoc(), 818 diag::err_reference_to_local_var_in_enclosing_function) 819 << D->getIdentifier() << FD->getDeclName(); 820 Diag(D->getLocation(), diag::note_local_variable_declared_here) 821 << D->getIdentifier(); 822 return ExprError(); 823 } 824 } 825 826 // This ridiculousness brought to you by 'extern void x;' and the 827 // GNU compiler collection. 828 } else if (!getLangOptions().CPlusPlus && !Ty.hasQualifiers() && 829 Ty->isVoidType()) { 830 VK = VK_RValue; 831 } 832 } 833 834 MarkDeclarationReferenced(NameInfo.getLoc(), D); 835 836 Expr *E = DeclRefExpr::Create(Context, 837 SS? (NestedNameSpecifier *)SS->getScopeRep() : 0, 838 SS? SS->getRange() : SourceRange(), 839 D, NameInfo, Ty, VK); 840 841 // Just in case we're building an illegal pointer-to-member. 842 if (isa<FieldDecl>(D) && cast<FieldDecl>(D)->getBitWidth()) 843 E->setObjectKind(OK_BitField); 844 845 return Owned(E); 846} 847 848static ExprResult 849BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, 850 const CXXScopeSpec &SS, FieldDecl *Field, 851 DeclAccessPair FoundDecl, 852 const DeclarationNameInfo &MemberNameInfo); 853 854ExprResult 855Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc, 856 IndirectFieldDecl *IndirectField, 857 Expr *BaseObjectExpr, 858 SourceLocation OpLoc) { 859 // Build the expression that refers to the base object, from 860 // which we will build a sequence of member references to each 861 // of the anonymous union objects and, eventually, the field we 862 // found via name lookup. 863 bool BaseObjectIsPointer = false; 864 Qualifiers BaseQuals; 865 VarDecl *BaseObject = IndirectField->getVarDecl(); 866 if (BaseObject) { 867 // BaseObject is an anonymous struct/union variable (and is, 868 // therefore, not part of another non-anonymous record). 869 MarkDeclarationReferenced(Loc, BaseObject); 870 BaseObjectExpr = 871 new (Context) DeclRefExpr(BaseObject, BaseObject->getType(), 872 VK_LValue, Loc); 873 BaseQuals 874 = Context.getCanonicalType(BaseObject->getType()).getQualifiers(); 875 } else if (BaseObjectExpr) { 876 // The caller provided the base object expression. Determine 877 // whether its a pointer and whether it adds any qualifiers to the 878 // anonymous struct/union fields we're looking into. 879 QualType ObjectType = BaseObjectExpr->getType(); 880 if (const PointerType *ObjectPtr = ObjectType->getAs<PointerType>()) { 881 BaseObjectIsPointer = true; 882 ObjectType = ObjectPtr->getPointeeType(); 883 } 884 BaseQuals 885 = Context.getCanonicalType(ObjectType).getQualifiers(); 886 } else { 887 // We've found a member of an anonymous struct/union that is 888 // inside a non-anonymous struct/union, so in a well-formed 889 // program our base object expression is "this". 890 DeclContext *DC = getFunctionLevelDeclContext(); 891 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC)) { 892 if (!MD->isStatic()) { 893 QualType AnonFieldType 894 = Context.getTagDeclType( 895 cast<RecordDecl>( 896 (*IndirectField->chain_begin())->getDeclContext())); 897 QualType ThisType = Context.getTagDeclType(MD->getParent()); 898 if ((Context.getCanonicalType(AnonFieldType) 899 == Context.getCanonicalType(ThisType)) || 900 IsDerivedFrom(ThisType, AnonFieldType)) { 901 // Our base object expression is "this". 902 BaseObjectExpr = new (Context) CXXThisExpr(Loc, 903 MD->getThisType(Context), 904 /*isImplicit=*/true); 905 BaseObjectIsPointer = true; 906 } 907 } else { 908 return ExprError(Diag(Loc,diag::err_invalid_member_use_in_static_method) 909 << IndirectField->getDeclName()); 910 } 911 BaseQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers()); 912 } 913 914 if (!BaseObjectExpr) 915 return ExprError(Diag(Loc, diag::err_invalid_non_static_member_use) 916 << IndirectField->getDeclName()); 917 } 918 919 // Build the implicit member references to the field of the 920 // anonymous struct/union. 921 Expr *Result = BaseObjectExpr; 922 923 IndirectFieldDecl::chain_iterator FI = IndirectField->chain_begin(), 924 FEnd = IndirectField->chain_end(); 925 926 // Skip the first VarDecl if present. 927 if (BaseObject) 928 FI++; 929 for (; FI != FEnd; FI++) { 930 FieldDecl *Field = cast<FieldDecl>(*FI); 931 932 // FIXME: the first access can be qualified 933 CXXScopeSpec SS; 934 935 // FIXME: these are somewhat meaningless 936 DeclarationNameInfo MemberNameInfo(Field->getDeclName(), Loc); 937 DeclAccessPair FoundDecl = DeclAccessPair::make(Field, Field->getAccess()); 938 939 Result = BuildFieldReferenceExpr(*this, Result, BaseObjectIsPointer, 940 SS, Field, FoundDecl, MemberNameInfo) 941 .take(); 942 943 // All the implicit accesses are dot-accesses. 944 BaseObjectIsPointer = false; 945 } 946 947 return Owned(Result); 948} 949 950/// Decomposes the given name into a DeclarationNameInfo, its location, and 951/// possibly a list of template arguments. 952/// 953/// If this produces template arguments, it is permitted to call 954/// DecomposeTemplateName. 955/// 956/// This actually loses a lot of source location information for 957/// non-standard name kinds; we should consider preserving that in 958/// some way. 959static void DecomposeUnqualifiedId(Sema &SemaRef, 960 const UnqualifiedId &Id, 961 TemplateArgumentListInfo &Buffer, 962 DeclarationNameInfo &NameInfo, 963 const TemplateArgumentListInfo *&TemplateArgs) { 964 if (Id.getKind() == UnqualifiedId::IK_TemplateId) { 965 Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); 966 Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); 967 968 ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, 969 Id.TemplateId->getTemplateArgs(), 970 Id.TemplateId->NumArgs); 971 SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); 972 TemplateArgsPtr.release(); 973 974 TemplateName TName = Id.TemplateId->Template.get(); 975 SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; 976 NameInfo = SemaRef.Context.getNameForTemplate(TName, TNameLoc); 977 TemplateArgs = &Buffer; 978 } else { 979 NameInfo = SemaRef.GetNameFromUnqualifiedId(Id); 980 TemplateArgs = 0; 981 } 982} 983 984/// Determines whether the given record is "fully-formed" at the given 985/// location, i.e. whether a qualified lookup into it is assured of 986/// getting consistent results already. 987static bool IsFullyFormedScope(Sema &SemaRef, CXXRecordDecl *Record) { 988 if (!Record->hasDefinition()) 989 return false; 990 991 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 992 E = Record->bases_end(); I != E; ++I) { 993 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 994 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 995 if (!BaseRT) return false; 996 997 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 998 if (!BaseRecord->hasDefinition() || 999 !IsFullyFormedScope(SemaRef, BaseRecord)) 1000 return false; 1001 } 1002 1003 return true; 1004} 1005 1006/// Determines if the given class is provably not derived from all of 1007/// the prospective base classes. 1008static bool IsProvablyNotDerivedFrom(Sema &SemaRef, 1009 CXXRecordDecl *Record, 1010 const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { 1011 if (Bases.count(Record->getCanonicalDecl())) 1012 return false; 1013 1014 RecordDecl *RD = Record->getDefinition(); 1015 if (!RD) return false; 1016 Record = cast<CXXRecordDecl>(RD); 1017 1018 for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), 1019 E = Record->bases_end(); I != E; ++I) { 1020 CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); 1021 CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); 1022 if (!BaseRT) return false; 1023 1024 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 1025 if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) 1026 return false; 1027 } 1028 1029 return true; 1030} 1031 1032enum IMAKind { 1033 /// The reference is definitely not an instance member access. 1034 IMA_Static, 1035 1036 /// The reference may be an implicit instance member access. 1037 IMA_Mixed, 1038 1039 /// The reference may be to an instance member, but it is invalid if 1040 /// so, because the context is not an instance method. 1041 IMA_Mixed_StaticContext, 1042 1043 /// The reference may be to an instance member, but it is invalid if 1044 /// so, because the context is from an unrelated class. 1045 IMA_Mixed_Unrelated, 1046 1047 /// The reference is definitely an implicit instance member access. 1048 IMA_Instance, 1049 1050 /// The reference may be to an unresolved using declaration. 1051 IMA_Unresolved, 1052 1053 /// The reference may be to an unresolved using declaration and the 1054 /// context is not an instance method. 1055 IMA_Unresolved_StaticContext, 1056 1057 /// All possible referrents are instance members and the current 1058 /// context is not an instance method. 1059 IMA_Error_StaticContext, 1060 1061 /// All possible referrents are instance members of an unrelated 1062 /// class. 1063 IMA_Error_Unrelated 1064}; 1065 1066/// The given lookup names class member(s) and is not being used for 1067/// an address-of-member expression. Classify the type of access 1068/// according to whether it's possible that this reference names an 1069/// instance member. This is best-effort; it is okay to 1070/// conservatively answer "yes", in which case some errors will simply 1071/// not be caught until template-instantiation. 1072static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, 1073 const LookupResult &R) { 1074 assert(!R.empty() && (*R.begin())->isCXXClassMember()); 1075 1076 DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); 1077 bool isStaticContext = 1078 (!isa<CXXMethodDecl>(DC) || 1079 cast<CXXMethodDecl>(DC)->isStatic()); 1080 1081 if (R.isUnresolvableResult()) 1082 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; 1083 1084 // Collect all the declaring classes of instance members we find. 1085 bool hasNonInstance = false; 1086 bool hasField = false; 1087 llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; 1088 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 1089 NamedDecl *D = *I; 1090 1091 if (D->isCXXInstanceMember()) { 1092 if (dyn_cast<FieldDecl>(D)) 1093 hasField = true; 1094 1095 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); 1096 Classes.insert(R->getCanonicalDecl()); 1097 } 1098 else 1099 hasNonInstance = true; 1100 } 1101 1102 // If we didn't find any instance members, it can't be an implicit 1103 // member reference. 1104 if (Classes.empty()) 1105 return IMA_Static; 1106 1107 // If the current context is not an instance method, it can't be 1108 // an implicit member reference. 1109 if (isStaticContext) { 1110 if (hasNonInstance) 1111 return IMA_Mixed_StaticContext; 1112 1113 if (SemaRef.getLangOptions().CPlusPlus0x && hasField) { 1114 // C++0x [expr.prim.general]p10: 1115 // An id-expression that denotes a non-static data member or non-static 1116 // member function of a class can only be used: 1117 // (...) 1118 // - if that id-expression denotes a non-static data member and it appears in an unevaluated operand. 1119 const Sema::ExpressionEvaluationContextRecord& record = SemaRef.ExprEvalContexts.back(); 1120 bool isUnevaluatedExpression = record.Context == Sema::Unevaluated; 1121 if (isUnevaluatedExpression) 1122 return IMA_Mixed_StaticContext; 1123 } 1124 1125 return IMA_Error_StaticContext; 1126 } 1127 1128 // If we can prove that the current context is unrelated to all the 1129 // declaring classes, it can't be an implicit member reference (in 1130 // which case it's an error if any of those members are selected). 1131 if (IsProvablyNotDerivedFrom(SemaRef, 1132 cast<CXXMethodDecl>(DC)->getParent(), 1133 Classes)) 1134 return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); 1135 1136 return (hasNonInstance ? IMA_Mixed : IMA_Instance); 1137} 1138 1139/// Diagnose a reference to a field with no object available. 1140static void DiagnoseInstanceReference(Sema &SemaRef, 1141 const CXXScopeSpec &SS, 1142 const LookupResult &R) { 1143 SourceLocation Loc = R.getNameLoc(); 1144 SourceRange Range(Loc); 1145 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); 1146 1147 if (R.getAsSingle<FieldDecl>()) { 1148 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { 1149 if (MD->isStatic()) { 1150 // "invalid use of member 'x' in static member function" 1151 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) 1152 << Range << R.getLookupName(); 1153 return; 1154 } 1155 } 1156 1157 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) 1158 << R.getLookupName() << Range; 1159 return; 1160 } 1161 1162 SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; 1163} 1164 1165/// Diagnose an empty lookup. 1166/// 1167/// \return false if new lookup candidates were found 1168bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, 1169 CorrectTypoContext CTC) { 1170 DeclarationName Name = R.getLookupName(); 1171 1172 unsigned diagnostic = diag::err_undeclared_var_use; 1173 unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; 1174 if (Name.getNameKind() == DeclarationName::CXXOperatorName || 1175 Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || 1176 Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { 1177 diagnostic = diag::err_undeclared_use; 1178 diagnostic_suggest = diag::err_undeclared_use_suggest; 1179 } 1180 1181 // If the original lookup was an unqualified lookup, fake an 1182 // unqualified lookup. This is useful when (for example) the 1183 // original lookup would not have found something because it was a 1184 // dependent name. 1185 for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; 1186 DC; DC = DC->getParent()) { 1187 if (isa<CXXRecordDecl>(DC)) { 1188 LookupQualifiedName(R, DC); 1189 1190 if (!R.empty()) { 1191 // Don't give errors about ambiguities in this lookup. 1192 R.suppressDiagnostics(); 1193 1194 CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); 1195 bool isInstance = CurMethod && 1196 CurMethod->isInstance() && 1197 DC == CurMethod->getParent(); 1198 1199 // Give a code modification hint to insert 'this->'. 1200 // TODO: fixit for inserting 'Base<T>::' in the other cases. 1201 // Actually quite difficult! 1202 if (isInstance) { 1203 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( 1204 CallsUndergoingInstantiation.back()->getCallee()); 1205 CXXMethodDecl *DepMethod = cast_or_null<CXXMethodDecl>( 1206 CurMethod->getInstantiatedFromMemberFunction()); 1207 if (DepMethod) { 1208 Diag(R.getNameLoc(), diagnostic) << Name 1209 << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); 1210 QualType DepThisType = DepMethod->getThisType(Context); 1211 CXXThisExpr *DepThis = new (Context) CXXThisExpr( 1212 R.getNameLoc(), DepThisType, false); 1213 TemplateArgumentListInfo TList; 1214 if (ULE->hasExplicitTemplateArgs()) 1215 ULE->copyTemplateArgumentsInto(TList); 1216 CXXDependentScopeMemberExpr *DepExpr = 1217 CXXDependentScopeMemberExpr::Create( 1218 Context, DepThis, DepThisType, true, SourceLocation(), 1219 ULE->getQualifier(), ULE->getQualifierRange(), NULL, 1220 R.getLookupNameInfo(), &TList); 1221 CallsUndergoingInstantiation.back()->setCallee(DepExpr); 1222 } else { 1223 // FIXME: we should be able to handle this case too. It is correct 1224 // to add this-> here. This is a workaround for PR7947. 1225 Diag(R.getNameLoc(), diagnostic) << Name; 1226 } 1227 } else { 1228 Diag(R.getNameLoc(), diagnostic) << Name; 1229 } 1230 1231 // Do we really want to note all of these? 1232 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 1233 Diag((*I)->getLocation(), diag::note_dependent_var_use); 1234 1235 // Tell the callee to try to recover. 1236 return false; 1237 } 1238 1239 R.clear(); 1240 } 1241 } 1242 1243 // We didn't find anything, so try to correct for a typo. 1244 DeclarationName Corrected; 1245 if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { 1246 if (!R.empty()) { 1247 if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { 1248 if (SS.isEmpty()) 1249 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() 1250 << FixItHint::CreateReplacement(R.getNameLoc(), 1251 R.getLookupName().getAsString()); 1252 else 1253 Diag(R.getNameLoc(), diag::err_no_member_suggest) 1254 << Name << computeDeclContext(SS, false) << R.getLookupName() 1255 << SS.getRange() 1256 << FixItHint::CreateReplacement(R.getNameLoc(), 1257 R.getLookupName().getAsString()); 1258 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 1259 Diag(ND->getLocation(), diag::note_previous_decl) 1260 << ND->getDeclName(); 1261 1262 // Tell the callee to try to recover. 1263 return false; 1264 } 1265 1266 if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { 1267 // FIXME: If we ended up with a typo for a type name or 1268 // Objective-C class name, we're in trouble because the parser 1269 // is in the wrong place to recover. Suggest the typo 1270 // correction, but don't make it a fix-it since we're not going 1271 // to recover well anyway. 1272 if (SS.isEmpty()) 1273 Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); 1274 else 1275 Diag(R.getNameLoc(), diag::err_no_member_suggest) 1276 << Name << computeDeclContext(SS, false) << R.getLookupName() 1277 << SS.getRange(); 1278 1279 // Don't try to recover; it won't work. 1280 return true; 1281 } 1282 } else { 1283 // FIXME: We found a keyword. Suggest it, but don't provide a fix-it 1284 // because we aren't able to recover. 1285 if (SS.isEmpty()) 1286 Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; 1287 else 1288 Diag(R.getNameLoc(), diag::err_no_member_suggest) 1289 << Name << computeDeclContext(SS, false) << Corrected 1290 << SS.getRange(); 1291 return true; 1292 } 1293 R.clear(); 1294 } 1295 1296 // Emit a special diagnostic for failed member lookups. 1297 // FIXME: computing the declaration context might fail here (?) 1298 if (!SS.isEmpty()) { 1299 Diag(R.getNameLoc(), diag::err_no_member) 1300 << Name << computeDeclContext(SS, false) 1301 << SS.getRange(); 1302 return true; 1303 } 1304 1305 // Give up, we can't recover. 1306 Diag(R.getNameLoc(), diagnostic) << Name; 1307 return true; 1308} 1309 1310ObjCPropertyDecl *Sema::canSynthesizeProvisionalIvar(IdentifierInfo *II) { 1311 ObjCMethodDecl *CurMeth = getCurMethodDecl(); 1312 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1313 if (!IDecl) 1314 return 0; 1315 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1316 if (!ClassImpDecl) 1317 return 0; 1318 ObjCPropertyDecl *property = LookupPropertyDecl(IDecl, II); 1319 if (!property) 1320 return 0; 1321 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) 1322 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic || 1323 PIDecl->getPropertyIvarDecl()) 1324 return 0; 1325 return property; 1326} 1327 1328bool Sema::canSynthesizeProvisionalIvar(ObjCPropertyDecl *Property) { 1329 ObjCMethodDecl *CurMeth = getCurMethodDecl(); 1330 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1331 if (!IDecl) 1332 return false; 1333 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1334 if (!ClassImpDecl) 1335 return false; 1336 if (ObjCPropertyImplDecl *PIDecl 1337 = ClassImpDecl->FindPropertyImplDecl(Property->getIdentifier())) 1338 if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic || 1339 PIDecl->getPropertyIvarDecl()) 1340 return false; 1341 1342 return true; 1343} 1344 1345static ObjCIvarDecl *SynthesizeProvisionalIvar(Sema &SemaRef, 1346 LookupResult &Lookup, 1347 IdentifierInfo *II, 1348 SourceLocation NameLoc) { 1349 ObjCMethodDecl *CurMeth = SemaRef.getCurMethodDecl(); 1350 bool LookForIvars; 1351 if (Lookup.empty()) 1352 LookForIvars = true; 1353 else if (CurMeth->isClassMethod()) 1354 LookForIvars = false; 1355 else 1356 LookForIvars = (Lookup.isSingleResult() && 1357 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1358 if (!LookForIvars) 1359 return 0; 1360 1361 ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); 1362 if (!IDecl) 1363 return 0; 1364 ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); 1365 if (!ClassImpDecl) 1366 return 0; 1367 bool DynamicImplSeen = false; 1368 ObjCPropertyDecl *property = SemaRef.LookupPropertyDecl(IDecl, II); 1369 if (!property) 1370 return 0; 1371 if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) { 1372 DynamicImplSeen = 1373 (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); 1374 // property implementation has a designated ivar. No need to assume a new 1375 // one. 1376 if (!DynamicImplSeen && PIDecl->getPropertyIvarDecl()) 1377 return 0; 1378 } 1379 if (!DynamicImplSeen) { 1380 QualType PropType = SemaRef.Context.getCanonicalType(property->getType()); 1381 ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(SemaRef.Context, ClassImpDecl, 1382 NameLoc, 1383 II, PropType, /*Dinfo=*/0, 1384 ObjCIvarDecl::Private, 1385 (Expr *)0, true); 1386 ClassImpDecl->addDecl(Ivar); 1387 IDecl->makeDeclVisibleInContext(Ivar, false); 1388 property->setPropertyIvarDecl(Ivar); 1389 return Ivar; 1390 } 1391 return 0; 1392} 1393 1394ExprResult Sema::ActOnIdExpression(Scope *S, 1395 CXXScopeSpec &SS, 1396 UnqualifiedId &Id, 1397 bool HasTrailingLParen, 1398 bool isAddressOfOperand) { 1399 assert(!(isAddressOfOperand && HasTrailingLParen) && 1400 "cannot be direct & operand and have a trailing lparen"); 1401 1402 if (SS.isInvalid()) 1403 return ExprError(); 1404 1405 TemplateArgumentListInfo TemplateArgsBuffer; 1406 1407 // Decompose the UnqualifiedId into the following data. 1408 DeclarationNameInfo NameInfo; 1409 const TemplateArgumentListInfo *TemplateArgs; 1410 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, NameInfo, TemplateArgs); 1411 1412 DeclarationName Name = NameInfo.getName(); 1413 IdentifierInfo *II = Name.getAsIdentifierInfo(); 1414 SourceLocation NameLoc = NameInfo.getLoc(); 1415 1416 // C++ [temp.dep.expr]p3: 1417 // An id-expression is type-dependent if it contains: 1418 // -- an identifier that was declared with a dependent type, 1419 // (note: handled after lookup) 1420 // -- a template-id that is dependent, 1421 // (note: handled in BuildTemplateIdExpr) 1422 // -- a conversion-function-id that specifies a dependent type, 1423 // -- a nested-name-specifier that contains a class-name that 1424 // names a dependent type. 1425 // Determine whether this is a member of an unknown specialization; 1426 // we need to handle these differently. 1427 bool DependentID = false; 1428 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && 1429 Name.getCXXNameType()->isDependentType()) { 1430 DependentID = true; 1431 } else if (SS.isSet()) { 1432 DeclContext *DC = computeDeclContext(SS, false); 1433 if (DC) { 1434 if (RequireCompleteDeclContext(SS, DC)) 1435 return ExprError(); 1436 // FIXME: We should be checking whether DC is the current instantiation. 1437 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) 1438 DependentID = !IsFullyFormedScope(*this, RD); 1439 } else { 1440 DependentID = true; 1441 } 1442 } 1443 1444 if (DependentID) { 1445 return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, 1446 TemplateArgs); 1447 } 1448 bool IvarLookupFollowUp = false; 1449 // Perform the required lookup. 1450 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1451 if (TemplateArgs) { 1452 // Lookup the template name again to correctly establish the context in 1453 // which it was found. This is really unfortunate as we already did the 1454 // lookup to determine that it was a template name in the first place. If 1455 // this becomes a performance hit, we can work harder to preserve those 1456 // results until we get here but it's likely not worth it. 1457 bool MemberOfUnknownSpecialization; 1458 LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, 1459 MemberOfUnknownSpecialization); 1460 } else { 1461 IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); 1462 LookupParsedName(R, S, &SS, !IvarLookupFollowUp); 1463 1464 // If this reference is in an Objective-C method, then we need to do 1465 // some special Objective-C lookup, too. 1466 if (IvarLookupFollowUp) { 1467 ExprResult E(LookupInObjCMethod(R, S, II, true)); 1468 if (E.isInvalid()) 1469 return ExprError(); 1470 1471 Expr *Ex = E.takeAs<Expr>(); 1472 if (Ex) return Owned(Ex); 1473 // Synthesize ivars lazily 1474 if (getLangOptions().ObjCDefaultSynthProperties && 1475 getLangOptions().ObjCNonFragileABI2) { 1476 if (SynthesizeProvisionalIvar(*this, R, II, NameLoc)) { 1477 if (const ObjCPropertyDecl *Property = 1478 canSynthesizeProvisionalIvar(II)) { 1479 Diag(NameLoc, diag::warn_synthesized_ivar_access) << II; 1480 Diag(Property->getLocation(), diag::note_property_declare); 1481 } 1482 return ActOnIdExpression(S, SS, Id, HasTrailingLParen, 1483 isAddressOfOperand); 1484 } 1485 } 1486 // for further use, this must be set to false if in class method. 1487 IvarLookupFollowUp = getCurMethodDecl()->isInstanceMethod(); 1488 } 1489 } 1490 1491 if (R.isAmbiguous()) 1492 return ExprError(); 1493 1494 // Determine whether this name might be a candidate for 1495 // argument-dependent lookup. 1496 bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); 1497 1498 if (R.empty() && !ADL) { 1499 // Otherwise, this could be an implicitly declared function reference (legal 1500 // in C90, extension in C99, forbidden in C++). 1501 if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { 1502 NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); 1503 if (D) R.addDecl(D); 1504 } 1505 1506 // If this name wasn't predeclared and if this is not a function 1507 // call, diagnose the problem. 1508 if (R.empty()) { 1509 if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) 1510 return ExprError(); 1511 1512 assert(!R.empty() && 1513 "DiagnoseEmptyLookup returned false but added no results"); 1514 1515 // If we found an Objective-C instance variable, let 1516 // LookupInObjCMethod build the appropriate expression to 1517 // reference the ivar. 1518 if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { 1519 R.clear(); 1520 ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); 1521 assert(E.isInvalid() || E.get()); 1522 return move(E); 1523 } 1524 } 1525 } 1526 1527 // This is guaranteed from this point on. 1528 assert(!R.empty() || ADL); 1529 1530 if (VarDecl *Var = R.getAsSingle<VarDecl>()) { 1531 if (getLangOptions().ObjCNonFragileABI && IvarLookupFollowUp && 1532 !(getLangOptions().ObjCDefaultSynthProperties && 1533 getLangOptions().ObjCNonFragileABI2) && 1534 Var->isFileVarDecl()) { 1535 ObjCPropertyDecl *Property = canSynthesizeProvisionalIvar(II); 1536 if (Property) { 1537 Diag(NameLoc, diag::warn_ivar_variable_conflict) << Var->getDeclName(); 1538 Diag(Property->getLocation(), diag::note_property_declare); 1539 Diag(Var->getLocation(), diag::note_global_declared_at); 1540 } 1541 } 1542 } else if (FunctionDecl *Func = R.getAsSingle<FunctionDecl>()) { 1543 if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) { 1544 // C99 DR 316 says that, if a function type comes from a 1545 // function definition (without a prototype), that type is only 1546 // used for checking compatibility. Therefore, when referencing 1547 // the function, we pretend that we don't have the full function 1548 // type. 1549 if (DiagnoseUseOfDecl(Func, NameLoc)) 1550 return ExprError(); 1551 1552 QualType T = Func->getType(); 1553 QualType NoProtoType = T; 1554 if (const FunctionProtoType *Proto = T->getAs<FunctionProtoType>()) 1555 NoProtoType = Context.getFunctionNoProtoType(Proto->getResultType(), 1556 Proto->getExtInfo()); 1557 // Note that functions are r-values in C. 1558 return BuildDeclRefExpr(Func, NoProtoType, VK_RValue, NameLoc, &SS); 1559 } 1560 } 1561 1562 // Check whether this might be a C++ implicit instance member access. 1563 // C++ [class.mfct.non-static]p3: 1564 // When an id-expression that is not part of a class member access 1565 // syntax and not used to form a pointer to member is used in the 1566 // body of a non-static member function of class X, if name lookup 1567 // resolves the name in the id-expression to a non-static non-type 1568 // member of some class C, the id-expression is transformed into a 1569 // class member access expression using (*this) as the 1570 // postfix-expression to the left of the . operator. 1571 // 1572 // But we don't actually need to do this for '&' operands if R 1573 // resolved to a function or overloaded function set, because the 1574 // expression is ill-formed if it actually works out to be a 1575 // non-static member function: 1576 // 1577 // C++ [expr.ref]p4: 1578 // Otherwise, if E1.E2 refers to a non-static member function. . . 1579 // [t]he expression can be used only as the left-hand operand of a 1580 // member function call. 1581 // 1582 // There are other safeguards against such uses, but it's important 1583 // to get this right here so that we don't end up making a 1584 // spuriously dependent expression if we're inside a dependent 1585 // instance method. 1586 if (!R.empty() && (*R.begin())->isCXXClassMember()) { 1587 bool MightBeImplicitMember; 1588 if (!isAddressOfOperand) 1589 MightBeImplicitMember = true; 1590 else if (!SS.isEmpty()) 1591 MightBeImplicitMember = false; 1592 else if (R.isOverloadedResult()) 1593 MightBeImplicitMember = false; 1594 else if (R.isUnresolvableResult()) 1595 MightBeImplicitMember = true; 1596 else 1597 MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()) || 1598 isa<IndirectFieldDecl>(R.getFoundDecl()); 1599 1600 if (MightBeImplicitMember) 1601 return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); 1602 } 1603 1604 if (TemplateArgs) 1605 return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); 1606 1607 return BuildDeclarationNameExpr(SS, R, ADL); 1608} 1609 1610/// Builds an expression which might be an implicit member expression. 1611ExprResult 1612Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, 1613 LookupResult &R, 1614 const TemplateArgumentListInfo *TemplateArgs) { 1615 switch (ClassifyImplicitMemberAccess(*this, R)) { 1616 case IMA_Instance: 1617 return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); 1618 1619 case IMA_Mixed: 1620 case IMA_Mixed_Unrelated: 1621 case IMA_Unresolved: 1622 return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); 1623 1624 case IMA_Static: 1625 case IMA_Mixed_StaticContext: 1626 case IMA_Unresolved_StaticContext: 1627 if (TemplateArgs) 1628 return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); 1629 return BuildDeclarationNameExpr(SS, R, false); 1630 1631 case IMA_Error_StaticContext: 1632 case IMA_Error_Unrelated: 1633 DiagnoseInstanceReference(*this, SS, R); 1634 return ExprError(); 1635 } 1636 1637 llvm_unreachable("unexpected instance member access kind"); 1638 return ExprError(); 1639} 1640 1641/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified 1642/// declaration name, generally during template instantiation. 1643/// There's a large number of things which don't need to be done along 1644/// this path. 1645ExprResult 1646Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, 1647 const DeclarationNameInfo &NameInfo) { 1648 DeclContext *DC; 1649 if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) 1650 return BuildDependentDeclRefExpr(SS, NameInfo, 0); 1651 1652 if (RequireCompleteDeclContext(SS, DC)) 1653 return ExprError(); 1654 1655 LookupResult R(*this, NameInfo, LookupOrdinaryName); 1656 LookupQualifiedName(R, DC); 1657 1658 if (R.isAmbiguous()) 1659 return ExprError(); 1660 1661 if (R.empty()) { 1662 Diag(NameInfo.getLoc(), diag::err_no_member) 1663 << NameInfo.getName() << DC << SS.getRange(); 1664 return ExprError(); 1665 } 1666 1667 return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); 1668} 1669 1670/// LookupInObjCMethod - The parser has read a name in, and Sema has 1671/// detected that we're currently inside an ObjC method. Perform some 1672/// additional lookup. 1673/// 1674/// Ideally, most of this would be done by lookup, but there's 1675/// actually quite a lot of extra work involved. 1676/// 1677/// Returns a null sentinel to indicate trivial success. 1678ExprResult 1679Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, 1680 IdentifierInfo *II, bool AllowBuiltinCreation) { 1681 SourceLocation Loc = Lookup.getNameLoc(); 1682 ObjCMethodDecl *CurMethod = getCurMethodDecl(); 1683 1684 // There are two cases to handle here. 1) scoped lookup could have failed, 1685 // in which case we should look for an ivar. 2) scoped lookup could have 1686 // found a decl, but that decl is outside the current instance method (i.e. 1687 // a global variable). In these two cases, we do a lookup for an ivar with 1688 // this name, if the lookup sucedes, we replace it our current decl. 1689 1690 // If we're in a class method, we don't normally want to look for 1691 // ivars. But if we don't find anything else, and there's an 1692 // ivar, that's an error. 1693 bool IsClassMethod = CurMethod->isClassMethod(); 1694 1695 bool LookForIvars; 1696 if (Lookup.empty()) 1697 LookForIvars = true; 1698 else if (IsClassMethod) 1699 LookForIvars = false; 1700 else 1701 LookForIvars = (Lookup.isSingleResult() && 1702 Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); 1703 ObjCInterfaceDecl *IFace = 0; 1704 if (LookForIvars) { 1705 IFace = CurMethod->getClassInterface(); 1706 ObjCInterfaceDecl *ClassDeclared; 1707 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1708 // Diagnose using an ivar in a class method. 1709 if (IsClassMethod) 1710 return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) 1711 << IV->getDeclName()); 1712 1713 // If we're referencing an invalid decl, just return this as a silent 1714 // error node. The error diagnostic was already emitted on the decl. 1715 if (IV->isInvalidDecl()) 1716 return ExprError(); 1717 1718 // Check if referencing a field with __attribute__((deprecated)). 1719 if (DiagnoseUseOfDecl(IV, Loc)) 1720 return ExprError(); 1721 1722 // Diagnose the use of an ivar outside of the declaring class. 1723 if (IV->getAccessControl() == ObjCIvarDecl::Private && 1724 ClassDeclared != IFace) 1725 Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); 1726 1727 // FIXME: This should use a new expr for a direct reference, don't 1728 // turn this into Self->ivar, just return a BareIVarExpr or something. 1729 IdentifierInfo &II = Context.Idents.get("self"); 1730 UnqualifiedId SelfName; 1731 SelfName.setIdentifier(&II, SourceLocation()); 1732 CXXScopeSpec SelfScopeSpec; 1733 ExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, 1734 SelfName, false, false); 1735 if (SelfExpr.isInvalid()) 1736 return ExprError(); 1737 1738 Expr *SelfE = SelfExpr.take(); 1739 DefaultLvalueConversion(SelfE); 1740 1741 MarkDeclarationReferenced(Loc, IV); 1742 return Owned(new (Context) 1743 ObjCIvarRefExpr(IV, IV->getType(), Loc, 1744 SelfE, true, true)); 1745 } 1746 } else if (CurMethod->isInstanceMethod()) { 1747 // We should warn if a local variable hides an ivar. 1748 ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); 1749 ObjCInterfaceDecl *ClassDeclared; 1750 if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { 1751 if (IV->getAccessControl() != ObjCIvarDecl::Private || 1752 IFace == ClassDeclared) 1753 Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); 1754 } 1755 } 1756 1757 if (Lookup.empty() && II && AllowBuiltinCreation) { 1758 // FIXME. Consolidate this with similar code in LookupName. 1759 if (unsigned BuiltinID = II->getBuiltinID()) { 1760 if (!(getLangOptions().CPlusPlus && 1761 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { 1762 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 1763 S, Lookup.isForRedeclaration(), 1764 Lookup.getNameLoc()); 1765 if (D) Lookup.addDecl(D); 1766 } 1767 } 1768 } 1769 // Sentinel value saying that we didn't do anything special. 1770 return Owned((Expr*) 0); 1771} 1772 1773/// \brief Cast a base object to a member's actual type. 1774/// 1775/// Logically this happens in three phases: 1776/// 1777/// * First we cast from the base type to the naming class. 1778/// The naming class is the class into which we were looking 1779/// when we found the member; it's the qualifier type if a 1780/// qualifier was provided, and otherwise it's the base type. 1781/// 1782/// * Next we cast from the naming class to the declaring class. 1783/// If the member we found was brought into a class's scope by 1784/// a using declaration, this is that class; otherwise it's 1785/// the class declaring the member. 1786/// 1787/// * Finally we cast from the declaring class to the "true" 1788/// declaring class of the member. This conversion does not 1789/// obey access control. 1790bool 1791Sema::PerformObjectMemberConversion(Expr *&From, 1792 NestedNameSpecifier *Qualifier, 1793 NamedDecl *FoundDecl, 1794 NamedDecl *Member) { 1795 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); 1796 if (!RD) 1797 return false; 1798 1799 QualType DestRecordType; 1800 QualType DestType; 1801 QualType FromRecordType; 1802 QualType FromType = From->getType(); 1803 bool PointerConversions = false; 1804 if (isa<FieldDecl>(Member)) { 1805 DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); 1806 1807 if (FromType->getAs<PointerType>()) { 1808 DestType = Context.getPointerType(DestRecordType); 1809 FromRecordType = FromType->getPointeeType(); 1810 PointerConversions = true; 1811 } else { 1812 DestType = DestRecordType; 1813 FromRecordType = FromType; 1814 } 1815 } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { 1816 if (Method->isStatic()) 1817 return false; 1818 1819 DestType = Method->getThisType(Context); 1820 DestRecordType = DestType->getPointeeType(); 1821 1822 if (FromType->getAs<PointerType>()) { 1823 FromRecordType = FromType->getPointeeType(); 1824 PointerConversions = true; 1825 } else { 1826 FromRecordType = FromType; 1827 DestType = DestRecordType; 1828 } 1829 } else { 1830 // No conversion necessary. 1831 return false; 1832 } 1833 1834 if (DestType->isDependentType() || FromType->isDependentType()) 1835 return false; 1836 1837 // If the unqualified types are the same, no conversion is necessary. 1838 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1839 return false; 1840 1841 SourceRange FromRange = From->getSourceRange(); 1842 SourceLocation FromLoc = FromRange.getBegin(); 1843 1844 ExprValueKind VK = CastCategory(From); 1845 1846 // C++ [class.member.lookup]p8: 1847 // [...] Ambiguities can often be resolved by qualifying a name with its 1848 // class name. 1849 // 1850 // If the member was a qualified name and the qualified referred to a 1851 // specific base subobject type, we'll cast to that intermediate type 1852 // first and then to the object in which the member is declared. That allows 1853 // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: 1854 // 1855 // class Base { public: int x; }; 1856 // class Derived1 : public Base { }; 1857 // class Derived2 : public Base { }; 1858 // class VeryDerived : public Derived1, public Derived2 { void f(); }; 1859 // 1860 // void VeryDerived::f() { 1861 // x = 17; // error: ambiguous base subobjects 1862 // Derived1::x = 17; // okay, pick the Base subobject of Derived1 1863 // } 1864 if (Qualifier) { 1865 QualType QType = QualType(Qualifier->getAsType(), 0); 1866 assert(!QType.isNull() && "lookup done with dependent qualifier?"); 1867 assert(QType->isRecordType() && "lookup done with non-record type"); 1868 1869 QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); 1870 1871 // In C++98, the qualifier type doesn't actually have to be a base 1872 // type of the object type, in which case we just ignore it. 1873 // Otherwise build the appropriate casts. 1874 if (IsDerivedFrom(FromRecordType, QRecordType)) { 1875 CXXCastPath BasePath; 1876 if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, 1877 FromLoc, FromRange, &BasePath)) 1878 return true; 1879 1880 if (PointerConversions) 1881 QType = Context.getPointerType(QType); 1882 ImpCastExprToType(From, QType, CK_UncheckedDerivedToBase, 1883 VK, &BasePath); 1884 1885 FromType = QType; 1886 FromRecordType = QRecordType; 1887 1888 // If the qualifier type was the same as the destination type, 1889 // we're done. 1890 if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) 1891 return false; 1892 } 1893 } 1894 1895 bool IgnoreAccess = false; 1896 1897 // If we actually found the member through a using declaration, cast 1898 // down to the using declaration's type. 1899 // 1900 // Pointer equality is fine here because only one declaration of a 1901 // class ever has member declarations. 1902 if (FoundDecl->getDeclContext() != Member->getDeclContext()) { 1903 assert(isa<UsingShadowDecl>(FoundDecl)); 1904 QualType URecordType = Context.getTypeDeclType( 1905 cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 1906 1907 // We only need to do this if the naming-class to declaring-class 1908 // conversion is non-trivial. 1909 if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { 1910 assert(IsDerivedFrom(FromRecordType, URecordType)); 1911 CXXCastPath BasePath; 1912 if (CheckDerivedToBaseConversion(FromRecordType, URecordType, 1913 FromLoc, FromRange, &BasePath)) 1914 return true; 1915 1916 QualType UType = URecordType; 1917 if (PointerConversions) 1918 UType = Context.getPointerType(UType); 1919 ImpCastExprToType(From, UType, CK_UncheckedDerivedToBase, 1920 VK, &BasePath); 1921 FromType = UType; 1922 FromRecordType = URecordType; 1923 } 1924 1925 // We don't do access control for the conversion from the 1926 // declaring class to the true declaring class. 1927 IgnoreAccess = true; 1928 } 1929 1930 CXXCastPath BasePath; 1931 if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, 1932 FromLoc, FromRange, &BasePath, 1933 IgnoreAccess)) 1934 return true; 1935 1936 ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase, 1937 VK, &BasePath); 1938 return false; 1939} 1940 1941/// \brief Build a MemberExpr AST node. 1942static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, 1943 const CXXScopeSpec &SS, ValueDecl *Member, 1944 DeclAccessPair FoundDecl, 1945 const DeclarationNameInfo &MemberNameInfo, 1946 QualType Ty, 1947 ExprValueKind VK, ExprObjectKind OK, 1948 const TemplateArgumentListInfo *TemplateArgs = 0) { 1949 NestedNameSpecifier *Qualifier = 0; 1950 SourceRange QualifierRange; 1951 if (SS.isSet()) { 1952 Qualifier = (NestedNameSpecifier *) SS.getScopeRep(); 1953 QualifierRange = SS.getRange(); 1954 } 1955 1956 return MemberExpr::Create(C, Base, isArrow, Qualifier, QualifierRange, 1957 Member, FoundDecl, MemberNameInfo, 1958 TemplateArgs, Ty, VK, OK); 1959} 1960 1961static ExprResult 1962BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, 1963 const CXXScopeSpec &SS, FieldDecl *Field, 1964 DeclAccessPair FoundDecl, 1965 const DeclarationNameInfo &MemberNameInfo) { 1966 // x.a is an l-value if 'a' has a reference type. Otherwise: 1967 // x.a is an l-value/x-value/pr-value if the base is (and note 1968 // that *x is always an l-value), except that if the base isn't 1969 // an ordinary object then we must have an rvalue. 1970 ExprValueKind VK = VK_LValue; 1971 ExprObjectKind OK = OK_Ordinary; 1972 if (!IsArrow) { 1973 if (BaseExpr->getObjectKind() == OK_Ordinary) 1974 VK = BaseExpr->getValueKind(); 1975 else 1976 VK = VK_RValue; 1977 } 1978 if (VK != VK_RValue && Field->isBitField()) 1979 OK = OK_BitField; 1980 1981 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] 1982 QualType MemberType = Field->getType(); 1983 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) { 1984 MemberType = Ref->getPointeeType(); 1985 VK = VK_LValue; 1986 } else { 1987 QualType BaseType = BaseExpr->getType(); 1988 if (IsArrow) BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 1989 1990 Qualifiers BaseQuals = BaseType.getQualifiers(); 1991 1992 // GC attributes are never picked up by members. 1993 BaseQuals.removeObjCGCAttr(); 1994 1995 // CVR attributes from the base are picked up by members, 1996 // except that 'mutable' members don't pick up 'const'. 1997 if (Field->isMutable()) BaseQuals.removeConst(); 1998 1999 Qualifiers MemberQuals 2000 = S.Context.getCanonicalType(MemberType).getQualifiers(); 2001 2002 // TR 18037 does not allow fields to be declared with address spaces. 2003 assert(!MemberQuals.hasAddressSpace()); 2004 2005 Qualifiers Combined = BaseQuals + MemberQuals; 2006 if (Combined != MemberQuals) 2007 MemberType = S.Context.getQualifiedType(MemberType, Combined); 2008 } 2009 2010 S.MarkDeclarationReferenced(MemberNameInfo.getLoc(), Field); 2011 if (S.PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(), 2012 FoundDecl, Field)) 2013 return ExprError(); 2014 return S.Owned(BuildMemberExpr(S.Context, BaseExpr, IsArrow, SS, 2015 Field, FoundDecl, MemberNameInfo, 2016 MemberType, VK, OK)); 2017} 2018 2019/// Builds an implicit member access expression. The current context 2020/// is known to be an instance method, and the given unqualified lookup 2021/// set is known to contain only instance members, at least one of which 2022/// is from an appropriate type. 2023ExprResult 2024Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, 2025 LookupResult &R, 2026 const TemplateArgumentListInfo *TemplateArgs, 2027 bool IsKnownInstance) { 2028 assert(!R.empty() && !R.isAmbiguous()); 2029 2030 SourceLocation Loc = R.getNameLoc(); 2031 2032 // We may have found a field within an anonymous union or struct 2033 // (C++ [class.union]). 2034 // FIXME: This needs to happen post-isImplicitMemberReference? 2035 // FIXME: template-ids inside anonymous structs? 2036 if (IndirectFieldDecl *FD = R.getAsSingle<IndirectFieldDecl>()) 2037 return BuildAnonymousStructUnionMemberReference(Loc, FD); 2038 2039 2040 // If this is known to be an instance access, go ahead and build a 2041 // 'this' expression now. 2042 DeclContext *DC = getFunctionLevelDeclContext(); 2043 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context); 2044 Expr *This = 0; // null signifies implicit access 2045 if (IsKnownInstance) { 2046 SourceLocation Loc = R.getNameLoc(); 2047 if (SS.getRange().isValid()) 2048 Loc = SS.getRange().getBegin(); 2049 This = new (Context) CXXThisExpr(Loc, ThisType, /*isImplicit=*/true); 2050 } 2051 2052 return BuildMemberReferenceExpr(This, ThisType, 2053 /*OpLoc*/ SourceLocation(), 2054 /*IsArrow*/ true, 2055 SS, 2056 /*FirstQualifierInScope*/ 0, 2057 R, TemplateArgs); 2058} 2059 2060bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, 2061 const LookupResult &R, 2062 bool HasTrailingLParen) { 2063 // Only when used directly as the postfix-expression of a call. 2064 if (!HasTrailingLParen) 2065 return false; 2066 2067 // Never if a scope specifier was provided. 2068 if (SS.isSet()) 2069 return false; 2070 2071 // Only in C++ or ObjC++. 2072 if (!getLangOptions().CPlusPlus) 2073 return false; 2074 2075 // Turn off ADL when we find certain kinds of declarations during 2076 // normal lookup: 2077 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 2078 NamedDecl *D = *I; 2079 2080 // C++0x [basic.lookup.argdep]p3: 2081 // -- a declaration of a class member 2082 // Since using decls preserve this property, we check this on the 2083 // original decl. 2084 if (D->isCXXClassMember()) 2085 return false; 2086 2087 // C++0x [basic.lookup.argdep]p3: 2088 // -- a block-scope function declaration that is not a 2089 // using-declaration 2090 // NOTE: we also trigger this for function templates (in fact, we 2091 // don't check the decl type at all, since all other decl types 2092 // turn off ADL anyway). 2093 if (isa<UsingShadowDecl>(D)) 2094 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2095 else if (D->getDeclContext()->isFunctionOrMethod()) 2096 return false; 2097 2098 // C++0x [basic.lookup.argdep]p3: 2099 // -- a declaration that is neither a function or a function 2100 // template 2101 // And also for builtin functions. 2102 if (isa<FunctionDecl>(D)) { 2103 FunctionDecl *FDecl = cast<FunctionDecl>(D); 2104 2105 // But also builtin functions. 2106 if (FDecl->getBuiltinID() && FDecl->isImplicit()) 2107 return false; 2108 } else if (!isa<FunctionTemplateDecl>(D)) 2109 return false; 2110 } 2111 2112 return true; 2113} 2114 2115 2116/// Diagnoses obvious problems with the use of the given declaration 2117/// as an expression. This is only actually called for lookups that 2118/// were not overloaded, and it doesn't promise that the declaration 2119/// will in fact be used. 2120static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { 2121 if (isa<TypedefDecl>(D)) { 2122 S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); 2123 return true; 2124 } 2125 2126 if (isa<ObjCInterfaceDecl>(D)) { 2127 S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); 2128 return true; 2129 } 2130 2131 if (isa<NamespaceDecl>(D)) { 2132 S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); 2133 return true; 2134 } 2135 2136 return false; 2137} 2138 2139ExprResult 2140Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 2141 LookupResult &R, 2142 bool NeedsADL) { 2143 // If this is a single, fully-resolved result and we don't need ADL, 2144 // just build an ordinary singleton decl ref. 2145 if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) 2146 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), 2147 R.getFoundDecl()); 2148 2149 // We only need to check the declaration if there's exactly one 2150 // result, because in the overloaded case the results can only be 2151 // functions and function templates. 2152 if (R.isSingleResult() && 2153 CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) 2154 return ExprError(); 2155 2156 // Otherwise, just build an unresolved lookup expression. Suppress 2157 // any lookup-related diagnostics; we'll hash these out later, when 2158 // we've picked a target. 2159 R.suppressDiagnostics(); 2160 2161 UnresolvedLookupExpr *ULE 2162 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), 2163 (NestedNameSpecifier*) SS.getScopeRep(), 2164 SS.getRange(), R.getLookupNameInfo(), 2165 NeedsADL, R.isOverloadedResult(), 2166 R.begin(), R.end()); 2167 2168 return Owned(ULE); 2169} 2170 2171static ExprValueKind getValueKindForDecl(ASTContext &Context, 2172 const ValueDecl *D) { 2173 // FIXME: It's not clear to me why NonTypeTemplateParmDecl is a VarDecl. 2174 if (isa<VarDecl>(D) && !isa<NonTypeTemplateParmDecl>(D)) return VK_LValue; 2175 if (isa<FieldDecl>(D)) return VK_LValue; 2176 if (!Context.getLangOptions().CPlusPlus) return VK_RValue; 2177 if (isa<FunctionDecl>(D)) { 2178 if (isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) 2179 return VK_RValue; 2180 return VK_LValue; 2181 } 2182 return Expr::getValueKindForType(D->getType()); 2183} 2184 2185 2186/// \brief Complete semantic analysis for a reference to the given declaration. 2187ExprResult 2188Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, 2189 const DeclarationNameInfo &NameInfo, 2190 NamedDecl *D) { 2191 assert(D && "Cannot refer to a NULL declaration"); 2192 assert(!isa<FunctionTemplateDecl>(D) && 2193 "Cannot refer unambiguously to a function template"); 2194 2195 SourceLocation Loc = NameInfo.getLoc(); 2196 if (CheckDeclInExpr(*this, Loc, D)) 2197 return ExprError(); 2198 2199 if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { 2200 // Specifically diagnose references to class templates that are missing 2201 // a template argument list. 2202 Diag(Loc, diag::err_template_decl_ref) 2203 << Template << SS.getRange(); 2204 Diag(Template->getLocation(), diag::note_template_decl_here); 2205 return ExprError(); 2206 } 2207 2208 // Make sure that we're referring to a value. 2209 ValueDecl *VD = dyn_cast<ValueDecl>(D); 2210 if (!VD) { 2211 Diag(Loc, diag::err_ref_non_value) 2212 << D << SS.getRange(); 2213 Diag(D->getLocation(), diag::note_declared_at); 2214 return ExprError(); 2215 } 2216 2217 // Check whether this declaration can be used. Note that we suppress 2218 // this check when we're going to perform argument-dependent lookup 2219 // on this function name, because this might not be the function 2220 // that overload resolution actually selects. 2221 if (DiagnoseUseOfDecl(VD, Loc)) 2222 return ExprError(); 2223 2224 // Only create DeclRefExpr's for valid Decl's. 2225 if (VD->isInvalidDecl()) 2226 return ExprError(); 2227 2228 // Handle anonymous. 2229 if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(VD)) 2230 return BuildAnonymousStructUnionMemberReference(Loc, FD); 2231 2232 ExprValueKind VK = getValueKindForDecl(Context, VD); 2233 2234 // If the identifier reference is inside a block, and it refers to a value 2235 // that is outside the block, create a BlockDeclRefExpr instead of a 2236 // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when 2237 // the block is formed. 2238 // 2239 // We do not do this for things like enum constants, global variables, etc, 2240 // as they do not get snapshotted. 2241 // 2242 if (getCurBlock() && 2243 ShouldSnapshotBlockValueReference(*this, getCurBlock(), VD)) { 2244 if (VD->getType().getTypePtr()->isVariablyModifiedType()) { 2245 Diag(Loc, diag::err_ref_vm_type); 2246 Diag(D->getLocation(), diag::note_declared_at); 2247 return ExprError(); 2248 } 2249 2250 if (VD->getType()->isArrayType()) { 2251 Diag(Loc, diag::err_ref_array_type); 2252 Diag(D->getLocation(), diag::note_declared_at); 2253 return ExprError(); 2254 } 2255 2256 MarkDeclarationReferenced(Loc, VD); 2257 QualType ExprTy = VD->getType().getNonReferenceType(); 2258 2259 // The BlocksAttr indicates the variable is bound by-reference. 2260 bool byrefVar = (VD->getAttr<BlocksAttr>() != 0); 2261 QualType T = VD->getType(); 2262 BlockDeclRefExpr *BDRE; 2263 2264 if (!byrefVar) { 2265 // This is to record that a 'const' was actually synthesize and added. 2266 bool constAdded = !ExprTy.isConstQualified(); 2267 // Variable will be bound by-copy, make it const within the closure. 2268 ExprTy.addConst(); 2269 BDRE = new (Context) BlockDeclRefExpr(VD, ExprTy, VK, 2270 Loc, false, constAdded); 2271 } 2272 else 2273 BDRE = new (Context) BlockDeclRefExpr(VD, ExprTy, VK, Loc, true); 2274 2275 if (getLangOptions().CPlusPlus) { 2276 if (!T->isDependentType() && !T->isReferenceType()) { 2277 Expr *E = new (Context) 2278 DeclRefExpr(const_cast<ValueDecl*>(BDRE->getDecl()), T, 2279 VK, SourceLocation()); 2280 if (T->getAs<RecordType>()) 2281 if (!T->isUnionType()) { 2282 ExprResult Res = PerformCopyInitialization( 2283 InitializedEntity::InitializeBlock(VD->getLocation(), 2284 T, false), 2285 SourceLocation(), 2286 Owned(E)); 2287 if (!Res.isInvalid()) { 2288 Res = MaybeCreateExprWithCleanups(Res); 2289 Expr *Init = Res.takeAs<Expr>(); 2290 BDRE->setCopyConstructorExpr(Init); 2291 } 2292 } 2293 } 2294 } 2295 return Owned(BDRE); 2296 } 2297 // If this reference is not in a block or if the referenced variable is 2298 // within the block, create a normal DeclRefExpr. 2299 2300 return BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), VK, 2301 NameInfo, &SS); 2302} 2303 2304ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, 2305 tok::TokenKind Kind) { 2306 PredefinedExpr::IdentType IT; 2307 2308 switch (Kind) { 2309 default: assert(0 && "Unknown simple primary expr!"); 2310 case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] 2311 case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; 2312 case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; 2313 } 2314 2315 // Pre-defined identifiers are of type char[x], where x is the length of the 2316 // string. 2317 2318 Decl *currentDecl = getCurFunctionOrMethodDecl(); 2319 if (!currentDecl && getCurBlock()) 2320 currentDecl = getCurBlock()->TheDecl; 2321 if (!currentDecl) { 2322 Diag(Loc, diag::ext_predef_outside_function); 2323 currentDecl = Context.getTranslationUnitDecl(); 2324 } 2325 2326 QualType ResTy; 2327 if (cast<DeclContext>(currentDecl)->isDependentContext()) { 2328 ResTy = Context.DependentTy; 2329 } else { 2330 unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); 2331 2332 llvm::APInt LengthI(32, Length + 1); 2333 ResTy = Context.CharTy.withConst(); 2334 ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); 2335 } 2336 return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); 2337} 2338 2339ExprResult Sema::ActOnCharacterConstant(const Token &Tok) { 2340 llvm::SmallString<16> CharBuffer; 2341 bool Invalid = false; 2342 llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); 2343 if (Invalid) 2344 return ExprError(); 2345 2346 CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), 2347 PP); 2348 if (Literal.hadError()) 2349 return ExprError(); 2350 2351 QualType Ty; 2352 if (!getLangOptions().CPlusPlus) 2353 Ty = Context.IntTy; // 'x' and L'x' -> int in C. 2354 else if (Literal.isWide()) 2355 Ty = Context.WCharTy; // L'x' -> wchar_t in C++. 2356 else if (Literal.isMultiChar()) 2357 Ty = Context.IntTy; // 'wxyz' -> int in C++. 2358 else 2359 Ty = Context.CharTy; // 'x' -> char in C++ 2360 2361 return Owned(new (Context) CharacterLiteral(Literal.getValue(), 2362 Literal.isWide(), 2363 Ty, Tok.getLocation())); 2364} 2365 2366ExprResult Sema::ActOnNumericConstant(const Token &Tok) { 2367 // Fast path for a single digit (which is quite common). A single digit 2368 // cannot have a trigraph, escaped newline, radix prefix, or type suffix. 2369 if (Tok.getLength() == 1) { 2370 const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); 2371 unsigned IntSize = Context.Target.getIntWidth(); 2372 return Owned(IntegerLiteral::Create(Context, llvm::APInt(IntSize, Val-'0'), 2373 Context.IntTy, Tok.getLocation())); 2374 } 2375 2376 llvm::SmallString<512> IntegerBuffer; 2377 // Add padding so that NumericLiteralParser can overread by one character. 2378 IntegerBuffer.resize(Tok.getLength()+1); 2379 const char *ThisTokBegin = &IntegerBuffer[0]; 2380 2381 // Get the spelling of the token, which eliminates trigraphs, etc. 2382 bool Invalid = false; 2383 unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); 2384 if (Invalid) 2385 return ExprError(); 2386 2387 NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, 2388 Tok.getLocation(), PP); 2389 if (Literal.hadError) 2390 return ExprError(); 2391 2392 Expr *Res; 2393 2394 if (Literal.isFloatingLiteral()) { 2395 QualType Ty; 2396 if (Literal.isFloat) 2397 Ty = Context.FloatTy; 2398 else if (!Literal.isLong) 2399 Ty = Context.DoubleTy; 2400 else 2401 Ty = Context.LongDoubleTy; 2402 2403 const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); 2404 2405 using llvm::APFloat; 2406 APFloat Val(Format); 2407 2408 APFloat::opStatus result = Literal.GetFloatValue(Val); 2409 2410 // Overflow is always an error, but underflow is only an error if 2411 // we underflowed to zero (APFloat reports denormals as underflow). 2412 if ((result & APFloat::opOverflow) || 2413 ((result & APFloat::opUnderflow) && Val.isZero())) { 2414 unsigned diagnostic; 2415 llvm::SmallString<20> buffer; 2416 if (result & APFloat::opOverflow) { 2417 diagnostic = diag::warn_float_overflow; 2418 APFloat::getLargest(Format).toString(buffer); 2419 } else { 2420 diagnostic = diag::warn_float_underflow; 2421 APFloat::getSmallest(Format).toString(buffer); 2422 } 2423 2424 Diag(Tok.getLocation(), diagnostic) 2425 << Ty 2426 << llvm::StringRef(buffer.data(), buffer.size()); 2427 } 2428 2429 bool isExact = (result == APFloat::opOK); 2430 Res = FloatingLiteral::Create(Context, Val, isExact, Ty, Tok.getLocation()); 2431 2432 if (getLangOptions().SinglePrecisionConstants && Ty == Context.DoubleTy) 2433 ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast); 2434 2435 } else if (!Literal.isIntegerLiteral()) { 2436 return ExprError(); 2437 } else { 2438 QualType Ty; 2439 2440 // long long is a C99 feature. 2441 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && 2442 Literal.isLongLong) 2443 Diag(Tok.getLocation(), diag::ext_longlong); 2444 2445 // Get the value in the widest-possible width. 2446 llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); 2447 2448 if (Literal.GetIntegerValue(ResultVal)) { 2449 // If this value didn't fit into uintmax_t, warn and force to ull. 2450 Diag(Tok.getLocation(), diag::warn_integer_too_large); 2451 Ty = Context.UnsignedLongLongTy; 2452 assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && 2453 "long long is not intmax_t?"); 2454 } else { 2455 // If this value fits into a ULL, try to figure out what else it fits into 2456 // according to the rules of C99 6.4.4.1p5. 2457 2458 // Octal, Hexadecimal, and integers with a U suffix are allowed to 2459 // be an unsigned int. 2460 bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; 2461 2462 // Check from smallest to largest, picking the smallest type we can. 2463 unsigned Width = 0; 2464 if (!Literal.isLong && !Literal.isLongLong) { 2465 // Are int/unsigned possibilities? 2466 unsigned IntSize = Context.Target.getIntWidth(); 2467 2468 // Does it fit in a unsigned int? 2469 if (ResultVal.isIntN(IntSize)) { 2470 // Does it fit in a signed int? 2471 if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) 2472 Ty = Context.IntTy; 2473 else if (AllowUnsigned) 2474 Ty = Context.UnsignedIntTy; 2475 Width = IntSize; 2476 } 2477 } 2478 2479 // Are long/unsigned long possibilities? 2480 if (Ty.isNull() && !Literal.isLongLong) { 2481 unsigned LongSize = Context.Target.getLongWidth(); 2482 2483 // Does it fit in a unsigned long? 2484 if (ResultVal.isIntN(LongSize)) { 2485 // Does it fit in a signed long? 2486 if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) 2487 Ty = Context.LongTy; 2488 else if (AllowUnsigned) 2489 Ty = Context.UnsignedLongTy; 2490 Width = LongSize; 2491 } 2492 } 2493 2494 // Finally, check long long if needed. 2495 if (Ty.isNull()) { 2496 unsigned LongLongSize = Context.Target.getLongLongWidth(); 2497 2498 // Does it fit in a unsigned long long? 2499 if (ResultVal.isIntN(LongLongSize)) { 2500 // Does it fit in a signed long long? 2501 // To be compatible with MSVC, hex integer literals ending with the 2502 // LL or i64 suffix are always signed in Microsoft mode. 2503 if (!Literal.isUnsigned && (ResultVal[LongLongSize-1] == 0 || 2504 (getLangOptions().Microsoft && Literal.isLongLong))) 2505 Ty = Context.LongLongTy; 2506 else if (AllowUnsigned) 2507 Ty = Context.UnsignedLongLongTy; 2508 Width = LongLongSize; 2509 } 2510 } 2511 2512 // If we still couldn't decide a type, we probably have something that 2513 // does not fit in a signed long long, but has no U suffix. 2514 if (Ty.isNull()) { 2515 Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); 2516 Ty = Context.UnsignedLongLongTy; 2517 Width = Context.Target.getLongLongWidth(); 2518 } 2519 2520 if (ResultVal.getBitWidth() != Width) 2521 ResultVal = ResultVal.trunc(Width); 2522 } 2523 Res = IntegerLiteral::Create(Context, ResultVal, Ty, Tok.getLocation()); 2524 } 2525 2526 // If this is an imaginary literal, create the ImaginaryLiteral wrapper. 2527 if (Literal.isImaginary) 2528 Res = new (Context) ImaginaryLiteral(Res, 2529 Context.getComplexType(Res->getType())); 2530 2531 return Owned(Res); 2532} 2533 2534ExprResult Sema::ActOnParenExpr(SourceLocation L, 2535 SourceLocation R, Expr *E) { 2536 assert((E != 0) && "ActOnParenExpr() missing expr"); 2537 return Owned(new (Context) ParenExpr(L, R, E)); 2538} 2539 2540/// The UsualUnaryConversions() function is *not* called by this routine. 2541/// See C99 6.3.2.1p[2-4] for more details. 2542bool Sema::CheckSizeOfAlignOfOperand(QualType exprType, 2543 SourceLocation OpLoc, 2544 SourceRange ExprRange, 2545 bool isSizeof) { 2546 if (exprType->isDependentType()) 2547 return false; 2548 2549 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, 2550 // the result is the size of the referenced type." 2551 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the 2552 // result shall be the alignment of the referenced type." 2553 if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) 2554 exprType = Ref->getPointeeType(); 2555 2556 // C99 6.5.3.4p1: 2557 if (exprType->isFunctionType()) { 2558 // alignof(function) is allowed as an extension. 2559 if (isSizeof) 2560 Diag(OpLoc, diag::ext_sizeof_function_type) << ExprRange; 2561 return false; 2562 } 2563 2564 // Allow sizeof(void)/alignof(void) as an extension. 2565 if (exprType->isVoidType()) { 2566 Diag(OpLoc, diag::ext_sizeof_void_type) 2567 << (isSizeof ? "sizeof" : "__alignof") << ExprRange; 2568 return false; 2569 } 2570 2571 if (RequireCompleteType(OpLoc, exprType, 2572 PDiag(diag::err_sizeof_alignof_incomplete_type) 2573 << int(!isSizeof) << ExprRange)) 2574 return true; 2575 2576 // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. 2577 if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { 2578 Diag(OpLoc, diag::err_sizeof_nonfragile_interface) 2579 << exprType << isSizeof << ExprRange; 2580 return true; 2581 } 2582 2583 return false; 2584} 2585 2586static bool CheckAlignOfExpr(Sema &S, Expr *E, SourceLocation OpLoc, 2587 SourceRange ExprRange) { 2588 E = E->IgnoreParens(); 2589 2590 // alignof decl is always ok. 2591 if (isa<DeclRefExpr>(E)) 2592 return false; 2593 2594 // Cannot know anything else if the expression is dependent. 2595 if (E->isTypeDependent()) 2596 return false; 2597 2598 if (E->getBitField()) { 2599 S. Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; 2600 return true; 2601 } 2602 2603 // Alignment of a field access is always okay, so long as it isn't a 2604 // bit-field. 2605 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) 2606 if (isa<FieldDecl>(ME->getMemberDecl())) 2607 return false; 2608 2609 return S.CheckSizeOfAlignOfOperand(E->getType(), OpLoc, ExprRange, false); 2610} 2611 2612/// \brief Build a sizeof or alignof expression given a type operand. 2613ExprResult 2614Sema::CreateSizeOfAlignOfExpr(TypeSourceInfo *TInfo, 2615 SourceLocation OpLoc, 2616 bool isSizeOf, SourceRange R) { 2617 if (!TInfo) 2618 return ExprError(); 2619 2620 QualType T = TInfo->getType(); 2621 2622 if (!T->isDependentType() && 2623 CheckSizeOfAlignOfOperand(T, OpLoc, R, isSizeOf)) 2624 return ExprError(); 2625 2626 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2627 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, TInfo, 2628 Context.getSizeType(), OpLoc, 2629 R.getEnd())); 2630} 2631 2632/// \brief Build a sizeof or alignof expression given an expression 2633/// operand. 2634ExprResult 2635Sema::CreateSizeOfAlignOfExpr(Expr *E, SourceLocation OpLoc, 2636 bool isSizeOf, SourceRange R) { 2637 // Verify that the operand is valid. 2638 bool isInvalid = false; 2639 if (E->isTypeDependent()) { 2640 // Delay type-checking for type-dependent expressions. 2641 } else if (!isSizeOf) { 2642 isInvalid = CheckAlignOfExpr(*this, E, OpLoc, R); 2643 } else if (E->getBitField()) { // C99 6.5.3.4p1. 2644 Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; 2645 isInvalid = true; 2646 } else if (E->getType()->isPlaceholderType()) { 2647 ExprResult PE = CheckPlaceholderExpr(E, OpLoc); 2648 if (PE.isInvalid()) return ExprError(); 2649 return CreateSizeOfAlignOfExpr(PE.take(), OpLoc, isSizeOf, R); 2650 } else { 2651 isInvalid = CheckSizeOfAlignOfOperand(E->getType(), OpLoc, R, true); 2652 } 2653 2654 if (isInvalid) 2655 return ExprError(); 2656 2657 // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. 2658 return Owned(new (Context) SizeOfAlignOfExpr(isSizeOf, E, 2659 Context.getSizeType(), OpLoc, 2660 R.getEnd())); 2661} 2662 2663/// ActOnSizeOfAlignOfExpr - Handle @c sizeof(type) and @c sizeof @c expr and 2664/// the same for @c alignof and @c __alignof 2665/// Note that the ArgRange is invalid if isType is false. 2666ExprResult 2667Sema::ActOnSizeOfAlignOfExpr(SourceLocation OpLoc, bool isSizeof, bool isType, 2668 void *TyOrEx, const SourceRange &ArgRange) { 2669 // If error parsing type, ignore. 2670 if (TyOrEx == 0) return ExprError(); 2671 2672 if (isType) { 2673 TypeSourceInfo *TInfo; 2674 (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); 2675 return CreateSizeOfAlignOfExpr(TInfo, OpLoc, isSizeof, ArgRange); 2676 } 2677 2678 Expr *ArgEx = (Expr *)TyOrEx; 2679 ExprResult Result 2680 = CreateSizeOfAlignOfExpr(ArgEx, OpLoc, isSizeof, ArgEx->getSourceRange()); 2681 2682 return move(Result); 2683} 2684 2685static QualType CheckRealImagOperand(Sema &S, Expr *&V, SourceLocation Loc, 2686 bool isReal) { 2687 if (V->isTypeDependent()) 2688 return S.Context.DependentTy; 2689 2690 // _Real and _Imag are only l-values for normal l-values. 2691 if (V->getObjectKind() != OK_Ordinary) 2692 S.DefaultLvalueConversion(V); 2693 2694 // These operators return the element type of a complex type. 2695 if (const ComplexType *CT = V->getType()->getAs<ComplexType>()) 2696 return CT->getElementType(); 2697 2698 // Otherwise they pass through real integer and floating point types here. 2699 if (V->getType()->isArithmeticType()) 2700 return V->getType(); 2701 2702 // Test for placeholders. 2703 ExprResult PR = S.CheckPlaceholderExpr(V, Loc); 2704 if (PR.isInvalid()) return QualType(); 2705 if (PR.take() != V) { 2706 V = PR.take(); 2707 return CheckRealImagOperand(S, V, Loc, isReal); 2708 } 2709 2710 // Reject anything else. 2711 S.Diag(Loc, diag::err_realimag_invalid_type) << V->getType() 2712 << (isReal ? "__real" : "__imag"); 2713 return QualType(); 2714} 2715 2716 2717 2718ExprResult 2719Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, 2720 tok::TokenKind Kind, Expr *Input) { 2721 UnaryOperatorKind Opc; 2722 switch (Kind) { 2723 default: assert(0 && "Unknown unary op!"); 2724 case tok::plusplus: Opc = UO_PostInc; break; 2725 case tok::minusminus: Opc = UO_PostDec; break; 2726 } 2727 2728 return BuildUnaryOp(S, OpLoc, Opc, Input); 2729} 2730 2731/// Expressions of certain arbitrary types are forbidden by C from 2732/// having l-value type. These are: 2733/// - 'void', but not qualified void 2734/// - function types 2735/// 2736/// The exact rule here is C99 6.3.2.1: 2737/// An lvalue is an expression with an object type or an incomplete 2738/// type other than void. 2739static bool IsCForbiddenLValueType(ASTContext &C, QualType T) { 2740 return ((T->isVoidType() && !T.hasQualifiers()) || 2741 T->isFunctionType()); 2742} 2743 2744ExprResult 2745Sema::ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc, 2746 Expr *Idx, SourceLocation RLoc) { 2747 // Since this might be a postfix expression, get rid of ParenListExprs. 2748 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 2749 if (Result.isInvalid()) return ExprError(); 2750 Base = Result.take(); 2751 2752 Expr *LHSExp = Base, *RHSExp = Idx; 2753 2754 if (getLangOptions().CPlusPlus && 2755 (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { 2756 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2757 Context.DependentTy, 2758 VK_LValue, OK_Ordinary, 2759 RLoc)); 2760 } 2761 2762 if (getLangOptions().CPlusPlus && 2763 (LHSExp->getType()->isRecordType() || 2764 LHSExp->getType()->isEnumeralType() || 2765 RHSExp->getType()->isRecordType() || 2766 RHSExp->getType()->isEnumeralType())) { 2767 return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, Base, Idx); 2768 } 2769 2770 return CreateBuiltinArraySubscriptExpr(Base, LLoc, Idx, RLoc); 2771} 2772 2773 2774ExprResult 2775Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, 2776 Expr *Idx, SourceLocation RLoc) { 2777 Expr *LHSExp = Base; 2778 Expr *RHSExp = Idx; 2779 2780 // Perform default conversions. 2781 if (!LHSExp->getType()->getAs<VectorType>()) 2782 DefaultFunctionArrayLvalueConversion(LHSExp); 2783 DefaultFunctionArrayLvalueConversion(RHSExp); 2784 2785 QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); 2786 ExprValueKind VK = VK_LValue; 2787 ExprObjectKind OK = OK_Ordinary; 2788 2789 // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent 2790 // to the expression *((e1)+(e2)). This means the array "Base" may actually be 2791 // in the subscript position. As a result, we need to derive the array base 2792 // and index from the expression types. 2793 Expr *BaseExpr, *IndexExpr; 2794 QualType ResultType; 2795 if (LHSTy->isDependentType() || RHSTy->isDependentType()) { 2796 BaseExpr = LHSExp; 2797 IndexExpr = RHSExp; 2798 ResultType = Context.DependentTy; 2799 } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { 2800 BaseExpr = LHSExp; 2801 IndexExpr = RHSExp; 2802 ResultType = PTy->getPointeeType(); 2803 } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { 2804 // Handle the uncommon case of "123[Ptr]". 2805 BaseExpr = RHSExp; 2806 IndexExpr = LHSExp; 2807 ResultType = PTy->getPointeeType(); 2808 } else if (const ObjCObjectPointerType *PTy = 2809 LHSTy->getAs<ObjCObjectPointerType>()) { 2810 BaseExpr = LHSExp; 2811 IndexExpr = RHSExp; 2812 ResultType = PTy->getPointeeType(); 2813 } else if (const ObjCObjectPointerType *PTy = 2814 RHSTy->getAs<ObjCObjectPointerType>()) { 2815 // Handle the uncommon case of "123[Ptr]". 2816 BaseExpr = RHSExp; 2817 IndexExpr = LHSExp; 2818 ResultType = PTy->getPointeeType(); 2819 } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { 2820 BaseExpr = LHSExp; // vectors: V[123] 2821 IndexExpr = RHSExp; 2822 VK = LHSExp->getValueKind(); 2823 if (VK != VK_RValue) 2824 OK = OK_VectorComponent; 2825 2826 // FIXME: need to deal with const... 2827 ResultType = VTy->getElementType(); 2828 } else if (LHSTy->isArrayType()) { 2829 // If we see an array that wasn't promoted by 2830 // DefaultFunctionArrayLvalueConversion, it must be an array that 2831 // wasn't promoted because of the C90 rule that doesn't 2832 // allow promoting non-lvalue arrays. Warn, then 2833 // force the promotion here. 2834 Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2835 LHSExp->getSourceRange(); 2836 ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), 2837 CK_ArrayToPointerDecay); 2838 LHSTy = LHSExp->getType(); 2839 2840 BaseExpr = LHSExp; 2841 IndexExpr = RHSExp; 2842 ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); 2843 } else if (RHSTy->isArrayType()) { 2844 // Same as previous, except for 123[f().a] case 2845 Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << 2846 RHSExp->getSourceRange(); 2847 ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), 2848 CK_ArrayToPointerDecay); 2849 RHSTy = RHSExp->getType(); 2850 2851 BaseExpr = RHSExp; 2852 IndexExpr = LHSExp; 2853 ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); 2854 } else { 2855 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) 2856 << LHSExp->getSourceRange() << RHSExp->getSourceRange()); 2857 } 2858 // C99 6.5.2.1p1 2859 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) 2860 return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) 2861 << IndexExpr->getSourceRange()); 2862 2863 if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || 2864 IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) 2865 && !IndexExpr->isTypeDependent()) 2866 Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); 2867 2868 // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, 2869 // C++ [expr.sub]p1: The type "T" shall be a completely-defined object 2870 // type. Note that Functions are not objects, and that (in C99 parlance) 2871 // incomplete types are not object types. 2872 if (ResultType->isFunctionType()) { 2873 Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) 2874 << ResultType << BaseExpr->getSourceRange(); 2875 return ExprError(); 2876 } 2877 2878 if (ResultType->isVoidType() && !getLangOptions().CPlusPlus) { 2879 // GNU extension: subscripting on pointer to void 2880 Diag(LLoc, diag::ext_gnu_void_ptr) 2881 << BaseExpr->getSourceRange(); 2882 2883 // C forbids expressions of unqualified void type from being l-values. 2884 // See IsCForbiddenLValueType. 2885 if (!ResultType.hasQualifiers()) VK = VK_RValue; 2886 } else if (!ResultType->isDependentType() && 2887 RequireCompleteType(LLoc, ResultType, 2888 PDiag(diag::err_subscript_incomplete_type) 2889 << BaseExpr->getSourceRange())) 2890 return ExprError(); 2891 2892 // Diagnose bad cases where we step over interface counts. 2893 if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 2894 Diag(LLoc, diag::err_subscript_nonfragile_interface) 2895 << ResultType << BaseExpr->getSourceRange(); 2896 return ExprError(); 2897 } 2898 2899 assert(VK == VK_RValue || LangOpts.CPlusPlus || 2900 !IsCForbiddenLValueType(Context, ResultType)); 2901 2902 return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, 2903 ResultType, VK, OK, RLoc)); 2904} 2905 2906/// Check an ext-vector component access expression. 2907/// 2908/// VK should be set in advance to the value kind of the base 2909/// expression. 2910static QualType 2911CheckExtVectorComponent(Sema &S, QualType baseType, ExprValueKind &VK, 2912 SourceLocation OpLoc, const IdentifierInfo *CompName, 2913 SourceLocation CompLoc) { 2914 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, 2915 // see FIXME there. 2916 // 2917 // FIXME: This logic can be greatly simplified by splitting it along 2918 // halving/not halving and reworking the component checking. 2919 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); 2920 2921 // The vector accessor can't exceed the number of elements. 2922 const char *compStr = CompName->getNameStart(); 2923 2924 // This flag determines whether or not the component is one of the four 2925 // special names that indicate a subset of exactly half the elements are 2926 // to be selected. 2927 bool HalvingSwizzle = false; 2928 2929 // This flag determines whether or not CompName has an 's' char prefix, 2930 // indicating that it is a string of hex values to be used as vector indices. 2931 bool HexSwizzle = *compStr == 's' || *compStr == 'S'; 2932 2933 bool HasRepeated = false; 2934 bool HasIndex[16] = {}; 2935 2936 int Idx; 2937 2938 // Check that we've found one of the special components, or that the component 2939 // names must come from the same set. 2940 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || 2941 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { 2942 HalvingSwizzle = true; 2943 } else if (!HexSwizzle && 2944 (Idx = vecType->getPointAccessorIdx(*compStr)) != -1) { 2945 do { 2946 if (HasIndex[Idx]) HasRepeated = true; 2947 HasIndex[Idx] = true; 2948 compStr++; 2949 } while (*compStr && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1); 2950 } else { 2951 if (HexSwizzle) compStr++; 2952 while ((Idx = vecType->getNumericAccessorIdx(*compStr)) != -1) { 2953 if (HasIndex[Idx]) HasRepeated = true; 2954 HasIndex[Idx] = true; 2955 compStr++; 2956 } 2957 } 2958 2959 if (!HalvingSwizzle && *compStr) { 2960 // We didn't get to the end of the string. This means the component names 2961 // didn't come from the same set *or* we encountered an illegal name. 2962 S.Diag(OpLoc, diag::err_ext_vector_component_name_illegal) 2963 << llvm::StringRef(compStr, 1) << SourceRange(CompLoc); 2964 return QualType(); 2965 } 2966 2967 // Ensure no component accessor exceeds the width of the vector type it 2968 // operates on. 2969 if (!HalvingSwizzle) { 2970 compStr = CompName->getNameStart(); 2971 2972 if (HexSwizzle) 2973 compStr++; 2974 2975 while (*compStr) { 2976 if (!vecType->isAccessorWithinNumElements(*compStr++)) { 2977 S.Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) 2978 << baseType << SourceRange(CompLoc); 2979 return QualType(); 2980 } 2981 } 2982 } 2983 2984 // The component accessor looks fine - now we need to compute the actual type. 2985 // The vector type is implied by the component accessor. For example, 2986 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. 2987 // vec4.s0 is a float, vec4.s23 is a vec3, etc. 2988 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. 2989 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 2990 : CompName->getLength(); 2991 if (HexSwizzle) 2992 CompSize--; 2993 2994 if (CompSize == 1) 2995 return vecType->getElementType(); 2996 2997 if (HasRepeated) VK = VK_RValue; 2998 2999 QualType VT = S.Context.getExtVectorType(vecType->getElementType(), CompSize); 3000 // Now look up the TypeDefDecl from the vector type. Without this, 3001 // diagostics look bad. We want extended vector types to appear built-in. 3002 for (unsigned i = 0, E = S.ExtVectorDecls.size(); i != E; ++i) { 3003 if (S.ExtVectorDecls[i]->getUnderlyingType() == VT) 3004 return S.Context.getTypedefType(S.ExtVectorDecls[i]); 3005 } 3006 return VT; // should never get here (a typedef type should always be found). 3007} 3008 3009static Decl *FindGetterSetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, 3010 IdentifierInfo *Member, 3011 const Selector &Sel, 3012 ASTContext &Context) { 3013 if (Member) 3014 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) 3015 return PD; 3016 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) 3017 return OMD; 3018 3019 for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), 3020 E = PDecl->protocol_end(); I != E; ++I) { 3021 if (Decl *D = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, 3022 Context)) 3023 return D; 3024 } 3025 return 0; 3026} 3027 3028static Decl *FindGetterSetterNameDecl(const ObjCObjectPointerType *QIdTy, 3029 IdentifierInfo *Member, 3030 const Selector &Sel, 3031 ASTContext &Context) { 3032 // Check protocols on qualified interfaces. 3033 Decl *GDecl = 0; 3034 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 3035 E = QIdTy->qual_end(); I != E; ++I) { 3036 if (Member) 3037 if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { 3038 GDecl = PD; 3039 break; 3040 } 3041 // Also must look for a getter or setter name which uses property syntax. 3042 if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { 3043 GDecl = OMD; 3044 break; 3045 } 3046 } 3047 if (!GDecl) { 3048 for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), 3049 E = QIdTy->qual_end(); I != E; ++I) { 3050 // Search in the protocol-qualifier list of current protocol. 3051 GDecl = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, 3052 Context); 3053 if (GDecl) 3054 return GDecl; 3055 } 3056 } 3057 return GDecl; 3058} 3059 3060ExprResult 3061Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, 3062 bool IsArrow, SourceLocation OpLoc, 3063 const CXXScopeSpec &SS, 3064 NamedDecl *FirstQualifierInScope, 3065 const DeclarationNameInfo &NameInfo, 3066 const TemplateArgumentListInfo *TemplateArgs) { 3067 // Even in dependent contexts, try to diagnose base expressions with 3068 // obviously wrong types, e.g.: 3069 // 3070 // T* t; 3071 // t.f; 3072 // 3073 // In Obj-C++, however, the above expression is valid, since it could be 3074 // accessing the 'f' property if T is an Obj-C interface. The extra check 3075 // allows this, while still reporting an error if T is a struct pointer. 3076 if (!IsArrow) { 3077 const PointerType *PT = BaseType->getAs<PointerType>(); 3078 if (PT && (!getLangOptions().ObjC1 || 3079 PT->getPointeeType()->isRecordType())) { 3080 assert(BaseExpr && "cannot happen with implicit member accesses"); 3081 Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) 3082 << BaseType << BaseExpr->getSourceRange(); 3083 return ExprError(); 3084 } 3085 } 3086 3087 assert(BaseType->isDependentType() || 3088 NameInfo.getName().isDependentName() || 3089 isDependentScopeSpecifier(SS)); 3090 3091 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr 3092 // must have pointer type, and the accessed type is the pointee. 3093 return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, 3094 IsArrow, OpLoc, 3095 SS.getScopeRep(), 3096 SS.getRange(), 3097 FirstQualifierInScope, 3098 NameInfo, TemplateArgs)); 3099} 3100 3101/// We know that the given qualified member reference points only to 3102/// declarations which do not belong to the static type of the base 3103/// expression. Diagnose the problem. 3104static void DiagnoseQualifiedMemberReference(Sema &SemaRef, 3105 Expr *BaseExpr, 3106 QualType BaseType, 3107 const CXXScopeSpec &SS, 3108 const LookupResult &R) { 3109 // If this is an implicit member access, use a different set of 3110 // diagnostics. 3111 if (!BaseExpr) 3112 return DiagnoseInstanceReference(SemaRef, SS, R); 3113 3114 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_of_unrelated) 3115 << SS.getRange() << R.getRepresentativeDecl() << BaseType; 3116} 3117 3118// Check whether the declarations we found through a nested-name 3119// specifier in a member expression are actually members of the base 3120// type. The restriction here is: 3121// 3122// C++ [expr.ref]p2: 3123// ... In these cases, the id-expression shall name a 3124// member of the class or of one of its base classes. 3125// 3126// So it's perfectly legitimate for the nested-name specifier to name 3127// an unrelated class, and for us to find an overload set including 3128// decls from classes which are not superclasses, as long as the decl 3129// we actually pick through overload resolution is from a superclass. 3130bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, 3131 QualType BaseType, 3132 const CXXScopeSpec &SS, 3133 const LookupResult &R) { 3134 const RecordType *BaseRT = BaseType->getAs<RecordType>(); 3135 if (!BaseRT) { 3136 // We can't check this yet because the base type is still 3137 // dependent. 3138 assert(BaseType->isDependentType()); 3139 return false; 3140 } 3141 CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); 3142 3143 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 3144 // If this is an implicit member reference and we find a 3145 // non-instance member, it's not an error. 3146 if (!BaseExpr && !(*I)->isCXXInstanceMember()) 3147 return false; 3148 3149 // Note that we use the DC of the decl, not the underlying decl. 3150 DeclContext *DC = (*I)->getDeclContext(); 3151 while (DC->isTransparentContext()) 3152 DC = DC->getParent(); 3153 3154 if (!DC->isRecord()) 3155 continue; 3156 3157 llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; 3158 MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); 3159 3160 if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) 3161 return false; 3162 } 3163 3164 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, R); 3165 return true; 3166} 3167 3168static bool 3169LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, 3170 SourceRange BaseRange, const RecordType *RTy, 3171 SourceLocation OpLoc, CXXScopeSpec &SS, 3172 bool HasTemplateArgs) { 3173 RecordDecl *RDecl = RTy->getDecl(); 3174 if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), 3175 SemaRef.PDiag(diag::err_typecheck_incomplete_tag) 3176 << BaseRange)) 3177 return true; 3178 3179 if (HasTemplateArgs) { 3180 // LookupTemplateName doesn't expect these both to exist simultaneously. 3181 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); 3182 3183 bool MOUS; 3184 SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); 3185 return false; 3186 } 3187 3188 DeclContext *DC = RDecl; 3189 if (SS.isSet()) { 3190 // If the member name was a qualified-id, look into the 3191 // nested-name-specifier. 3192 DC = SemaRef.computeDeclContext(SS, false); 3193 3194 if (SemaRef.RequireCompleteDeclContext(SS, DC)) { 3195 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) 3196 << SS.getRange() << DC; 3197 return true; 3198 } 3199 3200 assert(DC && "Cannot handle non-computable dependent contexts in lookup"); 3201 3202 if (!isa<TypeDecl>(DC)) { 3203 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) 3204 << DC << SS.getRange(); 3205 return true; 3206 } 3207 } 3208 3209 // The record definition is complete, now look up the member. 3210 SemaRef.LookupQualifiedName(R, DC); 3211 3212 if (!R.empty()) 3213 return false; 3214 3215 // We didn't find anything with the given name, so try to correct 3216 // for typos. 3217 DeclarationName Name = R.getLookupName(); 3218 if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && 3219 !R.empty() && 3220 (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { 3221 SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) 3222 << Name << DC << R.getLookupName() << SS.getRange() 3223 << FixItHint::CreateReplacement(R.getNameLoc(), 3224 R.getLookupName().getAsString()); 3225 if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) 3226 SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) 3227 << ND->getDeclName(); 3228 return false; 3229 } else { 3230 R.clear(); 3231 R.setLookupName(Name); 3232 } 3233 3234 return false; 3235} 3236 3237ExprResult 3238Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, 3239 SourceLocation OpLoc, bool IsArrow, 3240 CXXScopeSpec &SS, 3241 NamedDecl *FirstQualifierInScope, 3242 const DeclarationNameInfo &NameInfo, 3243 const TemplateArgumentListInfo *TemplateArgs) { 3244 if (BaseType->isDependentType() || 3245 (SS.isSet() && isDependentScopeSpecifier(SS))) 3246 return ActOnDependentMemberExpr(Base, BaseType, 3247 IsArrow, OpLoc, 3248 SS, FirstQualifierInScope, 3249 NameInfo, TemplateArgs); 3250 3251 LookupResult R(*this, NameInfo, LookupMemberName); 3252 3253 // Implicit member accesses. 3254 if (!Base) { 3255 QualType RecordTy = BaseType; 3256 if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); 3257 if (LookupMemberExprInRecord(*this, R, SourceRange(), 3258 RecordTy->getAs<RecordType>(), 3259 OpLoc, SS, TemplateArgs != 0)) 3260 return ExprError(); 3261 3262 // Explicit member accesses. 3263 } else { 3264 ExprResult Result = 3265 LookupMemberExpr(R, Base, IsArrow, OpLoc, 3266 SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); 3267 3268 if (Result.isInvalid()) { 3269 Owned(Base); 3270 return ExprError(); 3271 } 3272 3273 if (Result.get()) 3274 return move(Result); 3275 3276 // LookupMemberExpr can modify Base, and thus change BaseType 3277 BaseType = Base->getType(); 3278 } 3279 3280 return BuildMemberReferenceExpr(Base, BaseType, 3281 OpLoc, IsArrow, SS, FirstQualifierInScope, 3282 R, TemplateArgs); 3283} 3284 3285ExprResult 3286Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, 3287 SourceLocation OpLoc, bool IsArrow, 3288 const CXXScopeSpec &SS, 3289 NamedDecl *FirstQualifierInScope, 3290 LookupResult &R, 3291 const TemplateArgumentListInfo *TemplateArgs, 3292 bool SuppressQualifierCheck) { 3293 QualType BaseType = BaseExprType; 3294 if (IsArrow) { 3295 assert(BaseType->isPointerType()); 3296 BaseType = BaseType->getAs<PointerType>()->getPointeeType(); 3297 } 3298 R.setBaseObjectType(BaseType); 3299 3300 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 3301 const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); 3302 DeclarationName MemberName = MemberNameInfo.getName(); 3303 SourceLocation MemberLoc = MemberNameInfo.getLoc(); 3304 3305 if (R.isAmbiguous()) 3306 return ExprError(); 3307 3308 if (R.empty()) { 3309 // Rederive where we looked up. 3310 DeclContext *DC = (SS.isSet() 3311 ? computeDeclContext(SS, false) 3312 : BaseType->getAs<RecordType>()->getDecl()); 3313 3314 Diag(R.getNameLoc(), diag::err_no_member) 3315 << MemberName << DC 3316 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); 3317 return ExprError(); 3318 } 3319 3320 // Diagnose lookups that find only declarations from a non-base 3321 // type. This is possible for either qualified lookups (which may 3322 // have been qualified with an unrelated type) or implicit member 3323 // expressions (which were found with unqualified lookup and thus 3324 // may have come from an enclosing scope). Note that it's okay for 3325 // lookup to find declarations from a non-base type as long as those 3326 // aren't the ones picked by overload resolution. 3327 if ((SS.isSet() || !BaseExpr || 3328 (isa<CXXThisExpr>(BaseExpr) && 3329 cast<CXXThisExpr>(BaseExpr)->isImplicit())) && 3330 !SuppressQualifierCheck && 3331 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) 3332 return ExprError(); 3333 3334 // Construct an unresolved result if we in fact got an unresolved 3335 // result. 3336 if (R.isOverloadedResult() || R.isUnresolvableResult()) { 3337 // Suppress any lookup-related diagnostics; we'll do these when we 3338 // pick a member. 3339 R.suppressDiagnostics(); 3340 3341 UnresolvedMemberExpr *MemExpr 3342 = UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(), 3343 BaseExpr, BaseExprType, 3344 IsArrow, OpLoc, 3345 Qualifier, SS.getRange(), 3346 MemberNameInfo, 3347 TemplateArgs, R.begin(), R.end()); 3348 3349 return Owned(MemExpr); 3350 } 3351 3352 assert(R.isSingleResult()); 3353 DeclAccessPair FoundDecl = R.begin().getPair(); 3354 NamedDecl *MemberDecl = R.getFoundDecl(); 3355 3356 // FIXME: diagnose the presence of template arguments now. 3357 3358 // If the decl being referenced had an error, return an error for this 3359 // sub-expr without emitting another error, in order to avoid cascading 3360 // error cases. 3361 if (MemberDecl->isInvalidDecl()) 3362 return ExprError(); 3363 3364 // Handle the implicit-member-access case. 3365 if (!BaseExpr) { 3366 // If this is not an instance member, convert to a non-member access. 3367 if (!MemberDecl->isCXXInstanceMember()) 3368 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); 3369 3370 SourceLocation Loc = R.getNameLoc(); 3371 if (SS.getRange().isValid()) 3372 Loc = SS.getRange().getBegin(); 3373 BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); 3374 } 3375 3376 bool ShouldCheckUse = true; 3377 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { 3378 // Don't diagnose the use of a virtual member function unless it's 3379 // explicitly qualified. 3380 if (MD->isVirtual() && !SS.isSet()) 3381 ShouldCheckUse = false; 3382 } 3383 3384 // Check the use of this member. 3385 if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { 3386 Owned(BaseExpr); 3387 return ExprError(); 3388 } 3389 3390 // Perform a property load on the base regardless of whether we 3391 // actually need it for the declaration. 3392 if (BaseExpr->getObjectKind() == OK_ObjCProperty) 3393 ConvertPropertyForRValue(BaseExpr); 3394 3395 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) 3396 return BuildFieldReferenceExpr(*this, BaseExpr, IsArrow, 3397 SS, FD, FoundDecl, MemberNameInfo); 3398 3399 if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(MemberDecl)) 3400 // We may have found a field within an anonymous union or struct 3401 // (C++ [class.union]). 3402 return BuildAnonymousStructUnionMemberReference(MemberLoc, FD, 3403 BaseExpr, OpLoc); 3404 3405 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { 3406 MarkDeclarationReferenced(MemberLoc, Var); 3407 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 3408 Var, FoundDecl, MemberNameInfo, 3409 Var->getType().getNonReferenceType(), 3410 VK_LValue, OK_Ordinary)); 3411 } 3412 3413 if (CXXMethodDecl *MemberFn = dyn_cast<CXXMethodDecl>(MemberDecl)) { 3414 MarkDeclarationReferenced(MemberLoc, MemberDecl); 3415 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 3416 MemberFn, FoundDecl, MemberNameInfo, 3417 MemberFn->getType(), 3418 MemberFn->isInstance() ? VK_RValue : VK_LValue, 3419 OK_Ordinary)); 3420 } 3421 assert(!isa<FunctionDecl>(MemberDecl) && "member function not C++ method?"); 3422 3423 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { 3424 MarkDeclarationReferenced(MemberLoc, MemberDecl); 3425 return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, 3426 Enum, FoundDecl, MemberNameInfo, 3427 Enum->getType(), VK_RValue, OK_Ordinary)); 3428 } 3429 3430 Owned(BaseExpr); 3431 3432 // We found something that we didn't expect. Complain. 3433 if (isa<TypeDecl>(MemberDecl)) 3434 Diag(MemberLoc, diag::err_typecheck_member_reference_type) 3435 << MemberName << BaseType << int(IsArrow); 3436 else 3437 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) 3438 << MemberName << BaseType << int(IsArrow); 3439 3440 Diag(MemberDecl->getLocation(), diag::note_member_declared_here) 3441 << MemberName; 3442 R.suppressDiagnostics(); 3443 return ExprError(); 3444} 3445 3446/// Given that normal member access failed on the given expression, 3447/// and given that the expression's type involves builtin-id or 3448/// builtin-Class, decide whether substituting in the redefinition 3449/// types would be profitable. The redefinition type is whatever 3450/// this translation unit tried to typedef to id/Class; we store 3451/// it to the side and then re-use it in places like this. 3452static bool ShouldTryAgainWithRedefinitionType(Sema &S, Expr *&base) { 3453 const ObjCObjectPointerType *opty 3454 = base->getType()->getAs<ObjCObjectPointerType>(); 3455 if (!opty) return false; 3456 3457 const ObjCObjectType *ty = opty->getObjectType(); 3458 3459 QualType redef; 3460 if (ty->isObjCId()) { 3461 redef = S.Context.ObjCIdRedefinitionType; 3462 } else if (ty->isObjCClass()) { 3463 redef = S.Context.ObjCClassRedefinitionType; 3464 } else { 3465 return false; 3466 } 3467 3468 // Do the substitution as long as the redefinition type isn't just a 3469 // possibly-qualified pointer to builtin-id or builtin-Class again. 3470 opty = redef->getAs<ObjCObjectPointerType>(); 3471 if (opty && !opty->getObjectType()->getInterface() != 0) 3472 return false; 3473 3474 S.ImpCastExprToType(base, redef, CK_BitCast); 3475 return true; 3476} 3477 3478/// Look up the given member of the given non-type-dependent 3479/// expression. This can return in one of two ways: 3480/// * If it returns a sentinel null-but-valid result, the caller will 3481/// assume that lookup was performed and the results written into 3482/// the provided structure. It will take over from there. 3483/// * Otherwise, the returned expression will be produced in place of 3484/// an ordinary member expression. 3485/// 3486/// The ObjCImpDecl bit is a gross hack that will need to be properly 3487/// fixed for ObjC++. 3488ExprResult 3489Sema::LookupMemberExpr(LookupResult &R, Expr *&BaseExpr, 3490 bool &IsArrow, SourceLocation OpLoc, 3491 CXXScopeSpec &SS, 3492 Decl *ObjCImpDecl, bool HasTemplateArgs) { 3493 assert(BaseExpr && "no base expression"); 3494 3495 // Perform default conversions. 3496 DefaultFunctionArrayConversion(BaseExpr); 3497 if (IsArrow) DefaultLvalueConversion(BaseExpr); 3498 3499 QualType BaseType = BaseExpr->getType(); 3500 assert(!BaseType->isDependentType()); 3501 3502 DeclarationName MemberName = R.getLookupName(); 3503 SourceLocation MemberLoc = R.getNameLoc(); 3504 3505 // For later type-checking purposes, turn arrow accesses into dot 3506 // accesses. The only access type we support that doesn't follow 3507 // the C equivalence "a->b === (*a).b" is ObjC property accesses, 3508 // and those never use arrows, so this is unaffected. 3509 if (IsArrow) { 3510 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 3511 BaseType = Ptr->getPointeeType(); 3512 else if (const ObjCObjectPointerType *Ptr 3513 = BaseType->getAs<ObjCObjectPointerType>()) 3514 BaseType = Ptr->getPointeeType(); 3515 else if (BaseType->isRecordType()) { 3516 // Recover from arrow accesses to records, e.g.: 3517 // struct MyRecord foo; 3518 // foo->bar 3519 // This is actually well-formed in C++ if MyRecord has an 3520 // overloaded operator->, but that should have been dealt with 3521 // by now. 3522 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3523 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3524 << FixItHint::CreateReplacement(OpLoc, "."); 3525 IsArrow = false; 3526 } else { 3527 Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) 3528 << BaseType << BaseExpr->getSourceRange(); 3529 return ExprError(); 3530 } 3531 } 3532 3533 // Handle field access to simple records. 3534 if (const RecordType *RTy = BaseType->getAs<RecordType>()) { 3535 if (LookupMemberExprInRecord(*this, R, BaseExpr->getSourceRange(), 3536 RTy, OpLoc, SS, HasTemplateArgs)) 3537 return ExprError(); 3538 3539 // Returning valid-but-null is how we indicate to the caller that 3540 // the lookup result was filled in. 3541 return Owned((Expr*) 0); 3542 } 3543 3544 // Handle ivar access to Objective-C objects. 3545 if (const ObjCObjectType *OTy = BaseType->getAs<ObjCObjectType>()) { 3546 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3547 3548 // There are three cases for the base type: 3549 // - builtin id (qualified or unqualified) 3550 // - builtin Class (qualified or unqualified) 3551 // - an interface 3552 ObjCInterfaceDecl *IDecl = OTy->getInterface(); 3553 if (!IDecl) { 3554 // There's an implicit 'isa' ivar on all objects. 3555 // But we only actually find it this way on objects of type 'id', 3556 // apparently. 3557 if (OTy->isObjCId() && Member->isStr("isa")) 3558 return Owned(new (Context) ObjCIsaExpr(BaseExpr, IsArrow, MemberLoc, 3559 Context.getObjCClassType())); 3560 3561 if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) 3562 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3563 ObjCImpDecl, HasTemplateArgs); 3564 goto fail; 3565 } 3566 3567 ObjCInterfaceDecl *ClassDeclared; 3568 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); 3569 3570 if (!IV) { 3571 // Attempt to correct for typos in ivar names. 3572 LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), 3573 LookupMemberName); 3574 if (CorrectTypo(Res, 0, 0, IDecl, false, 3575 IsArrow ? CTC_ObjCIvarLookup 3576 : CTC_ObjCPropertyLookup) && 3577 (IV = Res.getAsSingle<ObjCIvarDecl>())) { 3578 Diag(R.getNameLoc(), 3579 diag::err_typecheck_member_reference_ivar_suggest) 3580 << IDecl->getDeclName() << MemberName << IV->getDeclName() 3581 << FixItHint::CreateReplacement(R.getNameLoc(), 3582 IV->getNameAsString()); 3583 Diag(IV->getLocation(), diag::note_previous_decl) 3584 << IV->getDeclName(); 3585 } else { 3586 Res.clear(); 3587 Res.setLookupName(Member); 3588 3589 Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) 3590 << IDecl->getDeclName() << MemberName 3591 << BaseExpr->getSourceRange(); 3592 return ExprError(); 3593 } 3594 } 3595 3596 // If the decl being referenced had an error, return an error for this 3597 // sub-expr without emitting another error, in order to avoid cascading 3598 // error cases. 3599 if (IV->isInvalidDecl()) 3600 return ExprError(); 3601 3602 // Check whether we can reference this field. 3603 if (DiagnoseUseOfDecl(IV, MemberLoc)) 3604 return ExprError(); 3605 if (IV->getAccessControl() != ObjCIvarDecl::Public && 3606 IV->getAccessControl() != ObjCIvarDecl::Package) { 3607 ObjCInterfaceDecl *ClassOfMethodDecl = 0; 3608 if (ObjCMethodDecl *MD = getCurMethodDecl()) 3609 ClassOfMethodDecl = MD->getClassInterface(); 3610 else if (ObjCImpDecl && getCurFunctionDecl()) { 3611 // Case of a c-function declared inside an objc implementation. 3612 // FIXME: For a c-style function nested inside an objc implementation 3613 // class, there is no implementation context available, so we pass 3614 // down the context as argument to this routine. Ideally, this context 3615 // need be passed down in the AST node and somehow calculated from the 3616 // AST for a function decl. 3617 if (ObjCImplementationDecl *IMPD = 3618 dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) 3619 ClassOfMethodDecl = IMPD->getClassInterface(); 3620 else if (ObjCCategoryImplDecl* CatImplClass = 3621 dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) 3622 ClassOfMethodDecl = CatImplClass->getClassInterface(); 3623 } 3624 3625 if (IV->getAccessControl() == ObjCIvarDecl::Private) { 3626 if (ClassDeclared != IDecl || 3627 ClassOfMethodDecl != ClassDeclared) 3628 Diag(MemberLoc, diag::error_private_ivar_access) 3629 << IV->getDeclName(); 3630 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) 3631 // @protected 3632 Diag(MemberLoc, diag::error_protected_ivar_access) 3633 << IV->getDeclName(); 3634 } 3635 3636 return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), 3637 MemberLoc, BaseExpr, 3638 IsArrow)); 3639 } 3640 3641 // Objective-C property access. 3642 const ObjCObjectPointerType *OPT; 3643 if (!IsArrow && (OPT = BaseType->getAs<ObjCObjectPointerType>())) { 3644 // This actually uses the base as an r-value. 3645 DefaultLvalueConversion(BaseExpr); 3646 assert(Context.hasSameUnqualifiedType(BaseType, BaseExpr->getType())); 3647 3648 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3649 3650 const ObjCObjectType *OT = OPT->getObjectType(); 3651 3652 // id, with and without qualifiers. 3653 if (OT->isObjCId()) { 3654 // Check protocols on qualified interfaces. 3655 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3656 if (Decl *PMDecl = FindGetterSetterNameDecl(OPT, Member, Sel, Context)) { 3657 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { 3658 // Check the use of this declaration 3659 if (DiagnoseUseOfDecl(PD, MemberLoc)) 3660 return ExprError(); 3661 3662 return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), 3663 VK_LValue, 3664 OK_ObjCProperty, 3665 MemberLoc, 3666 BaseExpr)); 3667 } 3668 3669 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { 3670 // Check the use of this method. 3671 if (DiagnoseUseOfDecl(OMD, MemberLoc)) 3672 return ExprError(); 3673 Selector SetterSel = 3674 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3675 PP.getSelectorTable(), Member); 3676 ObjCMethodDecl *SMD = 0; 3677 if (Decl *SDecl = FindGetterSetterNameDecl(OPT, /*Property id*/0, 3678 SetterSel, Context)) 3679 SMD = dyn_cast<ObjCMethodDecl>(SDecl); 3680 QualType PType = OMD->getSendResultType(); 3681 3682 ExprValueKind VK = VK_LValue; 3683 if (!getLangOptions().CPlusPlus && 3684 IsCForbiddenLValueType(Context, PType)) 3685 VK = VK_RValue; 3686 ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty); 3687 3688 return Owned(new (Context) ObjCPropertyRefExpr(OMD, SMD, PType, 3689 VK, OK, 3690 MemberLoc, BaseExpr)); 3691 } 3692 } 3693 3694 if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) 3695 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3696 ObjCImpDecl, HasTemplateArgs); 3697 3698 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3699 << MemberName << BaseType); 3700 } 3701 3702 // 'Class', unqualified only. 3703 if (OT->isObjCClass()) { 3704 // Only works in a method declaration (??!). 3705 ObjCMethodDecl *MD = getCurMethodDecl(); 3706 if (!MD) { 3707 if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) 3708 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3709 ObjCImpDecl, HasTemplateArgs); 3710 3711 goto fail; 3712 } 3713 3714 // Also must look for a getter name which uses property syntax. 3715 Selector Sel = PP.getSelectorTable().getNullarySelector(Member); 3716 ObjCInterfaceDecl *IFace = MD->getClassInterface(); 3717 ObjCMethodDecl *Getter; 3718 if ((Getter = IFace->lookupClassMethod(Sel))) { 3719 // Check the use of this method. 3720 if (DiagnoseUseOfDecl(Getter, MemberLoc)) 3721 return ExprError(); 3722 } else 3723 Getter = IFace->lookupPrivateMethod(Sel, false); 3724 // If we found a getter then this may be a valid dot-reference, we 3725 // will look for the matching setter, in case it is needed. 3726 Selector SetterSel = 3727 SelectorTable::constructSetterName(PP.getIdentifierTable(), 3728 PP.getSelectorTable(), Member); 3729 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); 3730 if (!Setter) { 3731 // If this reference is in an @implementation, also check for 'private' 3732 // methods. 3733 Setter = IFace->lookupPrivateMethod(SetterSel, false); 3734 } 3735 // Look through local category implementations associated with the class. 3736 if (!Setter) 3737 Setter = IFace->getCategoryClassMethod(SetterSel); 3738 3739 if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) 3740 return ExprError(); 3741 3742 if (Getter || Setter) { 3743 QualType PType; 3744 3745 ExprValueKind VK = VK_LValue; 3746 if (Getter) { 3747 PType = Getter->getSendResultType(); 3748 if (!getLangOptions().CPlusPlus && 3749 IsCForbiddenLValueType(Context, PType)) 3750 VK = VK_RValue; 3751 } else { 3752 // Get the expression type from Setter's incoming parameter. 3753 PType = (*(Setter->param_end() -1))->getType(); 3754 } 3755 ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty); 3756 3757 // FIXME: we must check that the setter has property type. 3758 return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter, 3759 PType, VK, OK, 3760 MemberLoc, BaseExpr)); 3761 } 3762 3763 if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) 3764 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3765 ObjCImpDecl, HasTemplateArgs); 3766 3767 return ExprError(Diag(MemberLoc, diag::err_property_not_found) 3768 << MemberName << BaseType); 3769 } 3770 3771 // Normal property access. 3772 return HandleExprPropertyRefExpr(OPT, BaseExpr, MemberName, MemberLoc, 3773 SourceLocation(), QualType(), false); 3774 } 3775 3776 // Handle 'field access' to vectors, such as 'V.xx'. 3777 if (BaseType->isExtVectorType()) { 3778 // FIXME: this expr should store IsArrow. 3779 IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); 3780 ExprValueKind VK = (IsArrow ? VK_LValue : BaseExpr->getValueKind()); 3781 QualType ret = CheckExtVectorComponent(*this, BaseType, VK, OpLoc, 3782 Member, MemberLoc); 3783 if (ret.isNull()) 3784 return ExprError(); 3785 3786 return Owned(new (Context) ExtVectorElementExpr(ret, VK, BaseExpr, 3787 *Member, MemberLoc)); 3788 } 3789 3790 // Adjust builtin-sel to the appropriate redefinition type if that's 3791 // not just a pointer to builtin-sel again. 3792 if (IsArrow && 3793 BaseType->isSpecificBuiltinType(BuiltinType::ObjCSel) && 3794 !Context.ObjCSelRedefinitionType->isObjCSelType()) { 3795 ImpCastExprToType(BaseExpr, Context.ObjCSelRedefinitionType, CK_BitCast); 3796 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3797 ObjCImpDecl, HasTemplateArgs); 3798 } 3799 3800 // Failure cases. 3801 fail: 3802 3803 // There's a possible road to recovery for function types. 3804 const FunctionType *Fun = 0; 3805 3806 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 3807 if ((Fun = Ptr->getPointeeType()->getAs<FunctionType>())) { 3808 // fall out, handled below. 3809 3810 // Recover from dot accesses to pointers, e.g.: 3811 // type *foo; 3812 // foo.bar 3813 // This is actually well-formed in two cases: 3814 // - 'type' is an Objective C type 3815 // - 'bar' is a pseudo-destructor name which happens to refer to 3816 // the appropriate pointer type 3817 } else if (Ptr->getPointeeType()->isRecordType() && 3818 MemberName.getNameKind() != DeclarationName::CXXDestructorName) { 3819 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 3820 << BaseType << int(IsArrow) << BaseExpr->getSourceRange() 3821 << FixItHint::CreateReplacement(OpLoc, "->"); 3822 3823 // Recurse as an -> access. 3824 IsArrow = true; 3825 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3826 ObjCImpDecl, HasTemplateArgs); 3827 } 3828 } else { 3829 Fun = BaseType->getAs<FunctionType>(); 3830 } 3831 3832 // If the user is trying to apply -> or . to a function pointer 3833 // type, it's probably because they forgot parentheses to call that 3834 // function. Suggest the addition of those parentheses, build the 3835 // call, and continue on. 3836 if (Fun || BaseType == Context.OverloadTy) { 3837 bool TryCall; 3838 if (BaseType == Context.OverloadTy) { 3839 TryCall = true; 3840 } else { 3841 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(Fun)) { 3842 TryCall = (FPT->getNumArgs() == 0); 3843 } else { 3844 TryCall = true; 3845 } 3846 3847 if (TryCall) { 3848 QualType ResultTy = Fun->getResultType(); 3849 TryCall = (!IsArrow && ResultTy->isRecordType()) || 3850 (IsArrow && ResultTy->isPointerType() && 3851 ResultTy->getAs<PointerType>()->getPointeeType()->isRecordType()); 3852 } 3853 } 3854 3855 3856 if (TryCall) { 3857 SourceLocation Loc = PP.getLocForEndOfToken(BaseExpr->getLocEnd()); 3858 Diag(BaseExpr->getExprLoc(), diag::err_member_reference_needs_call) 3859 << QualType(Fun, 0) 3860 << FixItHint::CreateInsertion(Loc, "()"); 3861 3862 ExprResult NewBase 3863 = ActOnCallExpr(0, BaseExpr, Loc, MultiExprArg(*this, 0, 0), Loc); 3864 if (NewBase.isInvalid()) 3865 return ExprError(); 3866 BaseExpr = NewBase.takeAs<Expr>(); 3867 3868 3869 DefaultFunctionArrayConversion(BaseExpr); 3870 BaseType = BaseExpr->getType(); 3871 3872 return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, 3873 ObjCImpDecl, HasTemplateArgs); 3874 } 3875 } 3876 3877 Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) 3878 << BaseType << BaseExpr->getSourceRange(); 3879 3880 return ExprError(); 3881} 3882 3883/// The main callback when the parser finds something like 3884/// expression . [nested-name-specifier] identifier 3885/// expression -> [nested-name-specifier] identifier 3886/// where 'identifier' encompasses a fairly broad spectrum of 3887/// possibilities, including destructor and operator references. 3888/// 3889/// \param OpKind either tok::arrow or tok::period 3890/// \param HasTrailingLParen whether the next token is '(', which 3891/// is used to diagnose mis-uses of special members that can 3892/// only be called 3893/// \param ObjCImpDecl the current ObjC @implementation decl; 3894/// this is an ugly hack around the fact that ObjC @implementations 3895/// aren't properly put in the context chain 3896ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, 3897 SourceLocation OpLoc, 3898 tok::TokenKind OpKind, 3899 CXXScopeSpec &SS, 3900 UnqualifiedId &Id, 3901 Decl *ObjCImpDecl, 3902 bool HasTrailingLParen) { 3903 if (SS.isSet() && SS.isInvalid()) 3904 return ExprError(); 3905 3906 // Warn about the explicit constructor calls Microsoft extension. 3907 if (getLangOptions().Microsoft && 3908 Id.getKind() == UnqualifiedId::IK_ConstructorName) 3909 Diag(Id.getSourceRange().getBegin(), 3910 diag::ext_ms_explicit_constructor_call); 3911 3912 TemplateArgumentListInfo TemplateArgsBuffer; 3913 3914 // Decompose the name into its component parts. 3915 DeclarationNameInfo NameInfo; 3916 const TemplateArgumentListInfo *TemplateArgs; 3917 DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, 3918 NameInfo, TemplateArgs); 3919 3920 DeclarationName Name = NameInfo.getName(); 3921 bool IsArrow = (OpKind == tok::arrow); 3922 3923 NamedDecl *FirstQualifierInScope 3924 = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, 3925 static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); 3926 3927 // This is a postfix expression, so get rid of ParenListExprs. 3928 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 3929 if (Result.isInvalid()) return ExprError(); 3930 Base = Result.take(); 3931 3932 if (Base->getType()->isDependentType() || Name.isDependentName() || 3933 isDependentScopeSpecifier(SS)) { 3934 Result = ActOnDependentMemberExpr(Base, Base->getType(), 3935 IsArrow, OpLoc, 3936 SS, FirstQualifierInScope, 3937 NameInfo, TemplateArgs); 3938 } else { 3939 LookupResult R(*this, NameInfo, LookupMemberName); 3940 Result = LookupMemberExpr(R, Base, IsArrow, OpLoc, 3941 SS, ObjCImpDecl, TemplateArgs != 0); 3942 3943 if (Result.isInvalid()) { 3944 Owned(Base); 3945 return ExprError(); 3946 } 3947 3948 if (Result.get()) { 3949 // The only way a reference to a destructor can be used is to 3950 // immediately call it, which falls into this case. If the 3951 // next token is not a '(', produce a diagnostic and build the 3952 // call now. 3953 if (!HasTrailingLParen && 3954 Id.getKind() == UnqualifiedId::IK_DestructorName) 3955 return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); 3956 3957 return move(Result); 3958 } 3959 3960 Result = BuildMemberReferenceExpr(Base, Base->getType(), 3961 OpLoc, IsArrow, SS, FirstQualifierInScope, 3962 R, TemplateArgs); 3963 } 3964 3965 return move(Result); 3966} 3967 3968ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, 3969 FunctionDecl *FD, 3970 ParmVarDecl *Param) { 3971 if (Param->hasUnparsedDefaultArg()) { 3972 Diag(CallLoc, 3973 diag::err_use_of_default_argument_to_function_declared_later) << 3974 FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); 3975 Diag(UnparsedDefaultArgLocs[Param], 3976 diag::note_default_argument_declared_here); 3977 return ExprError(); 3978 } 3979 3980 if (Param->hasUninstantiatedDefaultArg()) { 3981 Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); 3982 3983 // Instantiate the expression. 3984 MultiLevelTemplateArgumentList ArgList 3985 = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); 3986 3987 std::pair<const TemplateArgument *, unsigned> Innermost 3988 = ArgList.getInnermost(); 3989 InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, 3990 Innermost.second); 3991 3992 ExprResult Result; 3993 { 3994 // C++ [dcl.fct.default]p5: 3995 // The names in the [default argument] expression are bound, and 3996 // the semantic constraints are checked, at the point where the 3997 // default argument expression appears. 3998 ContextRAII SavedContext(*this, FD); 3999 Result = SubstExpr(UninstExpr, ArgList); 4000 } 4001 if (Result.isInvalid()) 4002 return ExprError(); 4003 4004 // Check the expression as an initializer for the parameter. 4005 InitializedEntity Entity 4006 = InitializedEntity::InitializeParameter(Context, Param); 4007 InitializationKind Kind 4008 = InitializationKind::CreateCopy(Param->getLocation(), 4009 /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); 4010 Expr *ResultE = Result.takeAs<Expr>(); 4011 4012 InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); 4013 Result = InitSeq.Perform(*this, Entity, Kind, 4014 MultiExprArg(*this, &ResultE, 1)); 4015 if (Result.isInvalid()) 4016 return ExprError(); 4017 4018 // Build the default argument expression. 4019 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, 4020 Result.takeAs<Expr>())); 4021 } 4022 4023 // If the default expression creates temporaries, we need to 4024 // push them to the current stack of expression temporaries so they'll 4025 // be properly destroyed. 4026 // FIXME: We should really be rebuilding the default argument with new 4027 // bound temporaries; see the comment in PR5810. 4028 for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) { 4029 CXXTemporary *Temporary = Param->getDefaultArgTemporary(i); 4030 MarkDeclarationReferenced(Param->getDefaultArg()->getLocStart(), 4031 const_cast<CXXDestructorDecl*>(Temporary->getDestructor())); 4032 ExprTemporaries.push_back(Temporary); 4033 } 4034 4035 // We already type-checked the argument, so we know it works. 4036 // Just mark all of the declarations in this potentially-evaluated expression 4037 // as being "referenced". 4038 MarkDeclarationsReferencedInExpr(Param->getDefaultArg()); 4039 return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); 4040} 4041 4042/// ConvertArgumentsForCall - Converts the arguments specified in 4043/// Args/NumArgs to the parameter types of the function FDecl with 4044/// function prototype Proto. Call is the call expression itself, and 4045/// Fn is the function expression. For a C++ member function, this 4046/// routine does not attempt to convert the object argument. Returns 4047/// true if the call is ill-formed. 4048bool 4049Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, 4050 FunctionDecl *FDecl, 4051 const FunctionProtoType *Proto, 4052 Expr **Args, unsigned NumArgs, 4053 SourceLocation RParenLoc) { 4054 // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by 4055 // assignment, to the types of the corresponding parameter, ... 4056 unsigned NumArgsInProto = Proto->getNumArgs(); 4057 bool Invalid = false; 4058 4059 // If too few arguments are available (and we don't have default 4060 // arguments for the remaining parameters), don't make the call. 4061 if (NumArgs < NumArgsInProto) { 4062 if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) 4063 return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) 4064 << Fn->getType()->isBlockPointerType() 4065 << NumArgsInProto << NumArgs << Fn->getSourceRange(); 4066 Call->setNumArgs(Context, NumArgsInProto); 4067 } 4068 4069 // If too many are passed and not variadic, error on the extras and drop 4070 // them. 4071 if (NumArgs > NumArgsInProto) { 4072 if (!Proto->isVariadic()) { 4073 Diag(Args[NumArgsInProto]->getLocStart(), 4074 diag::err_typecheck_call_too_many_args) 4075 << Fn->getType()->isBlockPointerType() 4076 << NumArgsInProto << NumArgs << Fn->getSourceRange() 4077 << SourceRange(Args[NumArgsInProto]->getLocStart(), 4078 Args[NumArgs-1]->getLocEnd()); 4079 // This deletes the extra arguments. 4080 Call->setNumArgs(Context, NumArgsInProto); 4081 return true; 4082 } 4083 } 4084 llvm::SmallVector<Expr *, 8> AllArgs; 4085 VariadicCallType CallType = 4086 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 4087 if (Fn->getType()->isBlockPointerType()) 4088 CallType = VariadicBlock; // Block 4089 else if (isa<MemberExpr>(Fn)) 4090 CallType = VariadicMethod; 4091 Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, 4092 Proto, 0, Args, NumArgs, AllArgs, CallType); 4093 if (Invalid) 4094 return true; 4095 unsigned TotalNumArgs = AllArgs.size(); 4096 for (unsigned i = 0; i < TotalNumArgs; ++i) 4097 Call->setArg(i, AllArgs[i]); 4098 4099 return false; 4100} 4101 4102bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, 4103 FunctionDecl *FDecl, 4104 const FunctionProtoType *Proto, 4105 unsigned FirstProtoArg, 4106 Expr **Args, unsigned NumArgs, 4107 llvm::SmallVector<Expr *, 8> &AllArgs, 4108 VariadicCallType CallType) { 4109 unsigned NumArgsInProto = Proto->getNumArgs(); 4110 unsigned NumArgsToCheck = NumArgs; 4111 bool Invalid = false; 4112 if (NumArgs != NumArgsInProto) 4113 // Use default arguments for missing arguments 4114 NumArgsToCheck = NumArgsInProto; 4115 unsigned ArgIx = 0; 4116 // Continue to check argument types (even if we have too few/many args). 4117 for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { 4118 QualType ProtoArgType = Proto->getArgType(i); 4119 4120 Expr *Arg; 4121 if (ArgIx < NumArgs) { 4122 Arg = Args[ArgIx++]; 4123 4124 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 4125 ProtoArgType, 4126 PDiag(diag::err_call_incomplete_argument) 4127 << Arg->getSourceRange())) 4128 return true; 4129 4130 // Pass the argument 4131 ParmVarDecl *Param = 0; 4132 if (FDecl && i < FDecl->getNumParams()) 4133 Param = FDecl->getParamDecl(i); 4134 4135 InitializedEntity Entity = 4136 Param? InitializedEntity::InitializeParameter(Context, Param) 4137 : InitializedEntity::InitializeParameter(Context, ProtoArgType); 4138 ExprResult ArgE = PerformCopyInitialization(Entity, 4139 SourceLocation(), 4140 Owned(Arg)); 4141 if (ArgE.isInvalid()) 4142 return true; 4143 4144 Arg = ArgE.takeAs<Expr>(); 4145 } else { 4146 ParmVarDecl *Param = FDecl->getParamDecl(i); 4147 4148 ExprResult ArgExpr = 4149 BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); 4150 if (ArgExpr.isInvalid()) 4151 return true; 4152 4153 Arg = ArgExpr.takeAs<Expr>(); 4154 } 4155 AllArgs.push_back(Arg); 4156 } 4157 4158 // If this is a variadic call, handle args passed through "...". 4159 if (CallType != VariadicDoesNotApply) { 4160 // Promote the arguments (C99 6.5.2.2p7). 4161 for (unsigned i = ArgIx; i != NumArgs; ++i) { 4162 Expr *Arg = Args[i]; 4163 Invalid |= DefaultVariadicArgumentPromotion(Arg, CallType, FDecl); 4164 AllArgs.push_back(Arg); 4165 } 4166 } 4167 return Invalid; 4168} 4169 4170/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. 4171/// This provides the location of the left/right parens and a list of comma 4172/// locations. 4173ExprResult 4174Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, 4175 MultiExprArg args, SourceLocation RParenLoc) { 4176 unsigned NumArgs = args.size(); 4177 4178 // Since this might be a postfix expression, get rid of ParenListExprs. 4179 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); 4180 if (Result.isInvalid()) return ExprError(); 4181 Fn = Result.take(); 4182 4183 Expr **Args = args.release(); 4184 4185 if (getLangOptions().CPlusPlus) { 4186 // If this is a pseudo-destructor expression, build the call immediately. 4187 if (isa<CXXPseudoDestructorExpr>(Fn)) { 4188 if (NumArgs > 0) { 4189 // Pseudo-destructor calls should not have any arguments. 4190 Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) 4191 << FixItHint::CreateRemoval( 4192 SourceRange(Args[0]->getLocStart(), 4193 Args[NumArgs-1]->getLocEnd())); 4194 4195 NumArgs = 0; 4196 } 4197 4198 return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, 4199 VK_RValue, RParenLoc)); 4200 } 4201 4202 // Determine whether this is a dependent call inside a C++ template, 4203 // in which case we won't do any semantic analysis now. 4204 // FIXME: Will need to cache the results of name lookup (including ADL) in 4205 // Fn. 4206 bool Dependent = false; 4207 if (Fn->isTypeDependent()) 4208 Dependent = true; 4209 else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) 4210 Dependent = true; 4211 4212 if (Dependent) 4213 return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, 4214 Context.DependentTy, VK_RValue, 4215 RParenLoc)); 4216 4217 // Determine whether this is a call to an object (C++ [over.call.object]). 4218 if (Fn->getType()->isRecordType()) 4219 return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, 4220 RParenLoc)); 4221 4222 Expr *NakedFn = Fn->IgnoreParens(); 4223 4224 // Determine whether this is a call to an unresolved member function. 4225 if (UnresolvedMemberExpr *MemE = dyn_cast<UnresolvedMemberExpr>(NakedFn)) { 4226 // If lookup was unresolved but not dependent (i.e. didn't find 4227 // an unresolved using declaration), it has to be an overloaded 4228 // function set, which means it must contain either multiple 4229 // declarations (all methods or method templates) or a single 4230 // method template. 4231 assert((MemE->getNumDecls() > 1) || 4232 isa<FunctionTemplateDecl>( 4233 (*MemE->decls_begin())->getUnderlyingDecl())); 4234 (void)MemE; 4235 4236 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 4237 RParenLoc); 4238 } 4239 4240 // Determine whether this is a call to a member function. 4241 if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(NakedFn)) { 4242 NamedDecl *MemDecl = MemExpr->getMemberDecl(); 4243 if (isa<CXXMethodDecl>(MemDecl)) 4244 return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, 4245 RParenLoc); 4246 } 4247 4248 // Determine whether this is a call to a pointer-to-member function. 4249 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(NakedFn)) { 4250 if (BO->getOpcode() == BO_PtrMemD || 4251 BO->getOpcode() == BO_PtrMemI) { 4252 if (const FunctionProtoType *FPT 4253 = BO->getType()->getAs<FunctionProtoType>()) { 4254 QualType ResultTy = FPT->getCallResultType(Context); 4255 ExprValueKind VK = Expr::getValueKindForType(FPT->getResultType()); 4256 4257 CXXMemberCallExpr *TheCall 4258 = new (Context) CXXMemberCallExpr(Context, Fn, Args, 4259 NumArgs, ResultTy, VK, 4260 RParenLoc); 4261 4262 if (CheckCallReturnType(FPT->getResultType(), 4263 BO->getRHS()->getSourceRange().getBegin(), 4264 TheCall, 0)) 4265 return ExprError(); 4266 4267 if (ConvertArgumentsForCall(TheCall, BO, 0, FPT, Args, NumArgs, 4268 RParenLoc)) 4269 return ExprError(); 4270 4271 return MaybeBindToTemporary(TheCall); 4272 } 4273 return ExprError(Diag(Fn->getLocStart(), 4274 diag::err_typecheck_call_not_function) 4275 << Fn->getType() << Fn->getSourceRange()); 4276 } 4277 } 4278 } 4279 4280 // If we're directly calling a function, get the appropriate declaration. 4281 // Also, in C++, keep track of whether we should perform argument-dependent 4282 // lookup and whether there were any explicitly-specified template arguments. 4283 4284 Expr *NakedFn = Fn->IgnoreParens(); 4285 if (isa<UnresolvedLookupExpr>(NakedFn)) { 4286 UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn); 4287 return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, 4288 RParenLoc); 4289 } 4290 4291 NamedDecl *NDecl = 0; 4292 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(NakedFn)) 4293 if (UnOp->getOpcode() == UO_AddrOf) 4294 NakedFn = UnOp->getSubExpr()->IgnoreParens(); 4295 4296 if (isa<DeclRefExpr>(NakedFn)) 4297 NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); 4298 4299 return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc); 4300} 4301 4302/// BuildResolvedCallExpr - Build a call to a resolved expression, 4303/// i.e. an expression not of \p OverloadTy. The expression should 4304/// unary-convert to an expression of function-pointer or 4305/// block-pointer type. 4306/// 4307/// \param NDecl the declaration being called, if available 4308ExprResult 4309Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, 4310 SourceLocation LParenLoc, 4311 Expr **Args, unsigned NumArgs, 4312 SourceLocation RParenLoc) { 4313 FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); 4314 4315 // Promote the function operand. 4316 UsualUnaryConversions(Fn); 4317 4318 // Make the call expr early, before semantic checks. This guarantees cleanup 4319 // of arguments and function on error. 4320 CallExpr *TheCall = new (Context) CallExpr(Context, Fn, 4321 Args, NumArgs, 4322 Context.BoolTy, 4323 VK_RValue, 4324 RParenLoc); 4325 4326 const FunctionType *FuncT; 4327 if (!Fn->getType()->isBlockPointerType()) { 4328 // C99 6.5.2.2p1 - "The expression that denotes the called function shall 4329 // have type pointer to function". 4330 const PointerType *PT = Fn->getType()->getAs<PointerType>(); 4331 if (PT == 0) 4332 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 4333 << Fn->getType() << Fn->getSourceRange()); 4334 FuncT = PT->getPointeeType()->getAs<FunctionType>(); 4335 } else { // This is a block call. 4336 FuncT = Fn->getType()->getAs<BlockPointerType>()->getPointeeType()-> 4337 getAs<FunctionType>(); 4338 } 4339 if (FuncT == 0) 4340 return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) 4341 << Fn->getType() << Fn->getSourceRange()); 4342 4343 // Check for a valid return type 4344 if (CheckCallReturnType(FuncT->getResultType(), 4345 Fn->getSourceRange().getBegin(), TheCall, 4346 FDecl)) 4347 return ExprError(); 4348 4349 // We know the result type of the call, set it. 4350 TheCall->setType(FuncT->getCallResultType(Context)); 4351 TheCall->setValueKind(Expr::getValueKindForType(FuncT->getResultType())); 4352 4353 if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { 4354 if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, NumArgs, 4355 RParenLoc)) 4356 return ExprError(); 4357 } else { 4358 assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); 4359 4360 if (FDecl) { 4361 // Check if we have too few/too many template arguments, based 4362 // on our knowledge of the function definition. 4363 const FunctionDecl *Def = 0; 4364 if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { 4365 const FunctionProtoType *Proto 4366 = Def->getType()->getAs<FunctionProtoType>(); 4367 if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) 4368 Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) 4369 << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); 4370 } 4371 4372 // If the function we're calling isn't a function prototype, but we have 4373 // a function prototype from a prior declaratiom, use that prototype. 4374 if (!FDecl->hasPrototype()) 4375 Proto = FDecl->getType()->getAs<FunctionProtoType>(); 4376 } 4377 4378 // Promote the arguments (C99 6.5.2.2p6). 4379 for (unsigned i = 0; i != NumArgs; i++) { 4380 Expr *Arg = Args[i]; 4381 4382 if (Proto && i < Proto->getNumArgs()) { 4383 InitializedEntity Entity 4384 = InitializedEntity::InitializeParameter(Context, 4385 Proto->getArgType(i)); 4386 ExprResult ArgE = PerformCopyInitialization(Entity, 4387 SourceLocation(), 4388 Owned(Arg)); 4389 if (ArgE.isInvalid()) 4390 return true; 4391 4392 Arg = ArgE.takeAs<Expr>(); 4393 4394 } else { 4395 DefaultArgumentPromotion(Arg); 4396 } 4397 4398 if (RequireCompleteType(Arg->getSourceRange().getBegin(), 4399 Arg->getType(), 4400 PDiag(diag::err_call_incomplete_argument) 4401 << Arg->getSourceRange())) 4402 return ExprError(); 4403 4404 TheCall->setArg(i, Arg); 4405 } 4406 } 4407 4408 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) 4409 if (!Method->isStatic()) 4410 return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) 4411 << Fn->getSourceRange()); 4412 4413 // Check for sentinels 4414 if (NDecl) 4415 DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); 4416 4417 // Do special checking on direct calls to functions. 4418 if (FDecl) { 4419 if (CheckFunctionCall(FDecl, TheCall)) 4420 return ExprError(); 4421 4422 if (unsigned BuiltinID = FDecl->getBuiltinID()) 4423 return CheckBuiltinFunctionCall(BuiltinID, TheCall); 4424 } else if (NDecl) { 4425 if (CheckBlockCall(NDecl, TheCall)) 4426 return ExprError(); 4427 } 4428 4429 return MaybeBindToTemporary(TheCall); 4430} 4431 4432ExprResult 4433Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, 4434 SourceLocation RParenLoc, Expr *InitExpr) { 4435 assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); 4436 // FIXME: put back this assert when initializers are worked out. 4437 //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); 4438 4439 TypeSourceInfo *TInfo; 4440 QualType literalType = GetTypeFromParser(Ty, &TInfo); 4441 if (!TInfo) 4442 TInfo = Context.getTrivialTypeSourceInfo(literalType); 4443 4444 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); 4445} 4446 4447ExprResult 4448Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, 4449 SourceLocation RParenLoc, Expr *literalExpr) { 4450 QualType literalType = TInfo->getType(); 4451 4452 if (literalType->isArrayType()) { 4453 if (RequireCompleteType(LParenLoc, Context.getBaseElementType(literalType), 4454 PDiag(diag::err_illegal_decl_array_incomplete_type) 4455 << SourceRange(LParenLoc, 4456 literalExpr->getSourceRange().getEnd()))) 4457 return ExprError(); 4458 if (literalType->isVariableArrayType()) 4459 return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) 4460 << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); 4461 } else if (!literalType->isDependentType() && 4462 RequireCompleteType(LParenLoc, literalType, 4463 PDiag(diag::err_typecheck_decl_incomplete_type) 4464 << SourceRange(LParenLoc, 4465 literalExpr->getSourceRange().getEnd()))) 4466 return ExprError(); 4467 4468 InitializedEntity Entity 4469 = InitializedEntity::InitializeTemporary(literalType); 4470 InitializationKind Kind 4471 = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), 4472 /*IsCStyleCast=*/true); 4473 InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); 4474 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, 4475 MultiExprArg(*this, &literalExpr, 1), 4476 &literalType); 4477 if (Result.isInvalid()) 4478 return ExprError(); 4479 literalExpr = Result.get(); 4480 4481 bool isFileScope = getCurFunctionOrMethodDecl() == 0; 4482 if (isFileScope) { // 6.5.2.5p3 4483 if (CheckForConstantInitializer(literalExpr, literalType)) 4484 return ExprError(); 4485 } 4486 4487 // In C, compound literals are l-values for some reason. 4488 ExprValueKind VK = getLangOptions().CPlusPlus ? VK_RValue : VK_LValue; 4489 4490 return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, 4491 VK, literalExpr, isFileScope)); 4492} 4493 4494ExprResult 4495Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, 4496 SourceLocation RBraceLoc) { 4497 unsigned NumInit = initlist.size(); 4498 Expr **InitList = initlist.release(); 4499 4500 // Semantic analysis for initializers is done by ActOnDeclarator() and 4501 // CheckInitializer() - it requires knowledge of the object being intialized. 4502 4503 InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, 4504 NumInit, RBraceLoc); 4505 E->setType(Context.VoidTy); // FIXME: just a place holder for now. 4506 return Owned(E); 4507} 4508 4509/// Prepares for a scalar cast, performing all the necessary stages 4510/// except the final cast and returning the kind required. 4511static CastKind PrepareScalarCast(Sema &S, Expr *&Src, QualType DestTy) { 4512 // Both Src and Dest are scalar types, i.e. arithmetic or pointer. 4513 // Also, callers should have filtered out the invalid cases with 4514 // pointers. Everything else should be possible. 4515 4516 QualType SrcTy = Src->getType(); 4517 if (S.Context.hasSameUnqualifiedType(SrcTy, DestTy)) 4518 return CK_NoOp; 4519 4520 switch (SrcTy->getScalarTypeKind()) { 4521 case Type::STK_MemberPointer: 4522 llvm_unreachable("member pointer type in C"); 4523 4524 case Type::STK_Pointer: 4525 switch (DestTy->getScalarTypeKind()) { 4526 case Type::STK_Pointer: 4527 return DestTy->isObjCObjectPointerType() ? 4528 CK_AnyPointerToObjCPointerCast : 4529 CK_BitCast; 4530 case Type::STK_Bool: 4531 return CK_PointerToBoolean; 4532 case Type::STK_Integral: 4533 return CK_PointerToIntegral; 4534 case Type::STK_Floating: 4535 case Type::STK_FloatingComplex: 4536 case Type::STK_IntegralComplex: 4537 case Type::STK_MemberPointer: 4538 llvm_unreachable("illegal cast from pointer"); 4539 } 4540 break; 4541 4542 case Type::STK_Bool: // casting from bool is like casting from an integer 4543 case Type::STK_Integral: 4544 switch (DestTy->getScalarTypeKind()) { 4545 case Type::STK_Pointer: 4546 if (Src->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNull)) 4547 return CK_NullToPointer; 4548 return CK_IntegralToPointer; 4549 case Type::STK_Bool: 4550 return CK_IntegralToBoolean; 4551 case Type::STK_Integral: 4552 return CK_IntegralCast; 4553 case Type::STK_Floating: 4554 return CK_IntegralToFloating; 4555 case Type::STK_IntegralComplex: 4556 S.ImpCastExprToType(Src, DestTy->getAs<ComplexType>()->getElementType(), 4557 CK_IntegralCast); 4558 return CK_IntegralRealToComplex; 4559 case Type::STK_FloatingComplex: 4560 S.ImpCastExprToType(Src, DestTy->getAs<ComplexType>()->getElementType(), 4561 CK_IntegralToFloating); 4562 return CK_FloatingRealToComplex; 4563 case Type::STK_MemberPointer: 4564 llvm_unreachable("member pointer type in C"); 4565 } 4566 break; 4567 4568 case Type::STK_Floating: 4569 switch (DestTy->getScalarTypeKind()) { 4570 case Type::STK_Floating: 4571 return CK_FloatingCast; 4572 case Type::STK_Bool: 4573 return CK_FloatingToBoolean; 4574 case Type::STK_Integral: 4575 return CK_FloatingToIntegral; 4576 case Type::STK_FloatingComplex: 4577 S.ImpCastExprToType(Src, DestTy->getAs<ComplexType>()->getElementType(), 4578 CK_FloatingCast); 4579 return CK_FloatingRealToComplex; 4580 case Type::STK_IntegralComplex: 4581 S.ImpCastExprToType(Src, DestTy->getAs<ComplexType>()->getElementType(), 4582 CK_FloatingToIntegral); 4583 return CK_IntegralRealToComplex; 4584 case Type::STK_Pointer: 4585 llvm_unreachable("valid float->pointer cast?"); 4586 case Type::STK_MemberPointer: 4587 llvm_unreachable("member pointer type in C"); 4588 } 4589 break; 4590 4591 case Type::STK_FloatingComplex: 4592 switch (DestTy->getScalarTypeKind()) { 4593 case Type::STK_FloatingComplex: 4594 return CK_FloatingComplexCast; 4595 case Type::STK_IntegralComplex: 4596 return CK_FloatingComplexToIntegralComplex; 4597 case Type::STK_Floating: { 4598 QualType ET = SrcTy->getAs<ComplexType>()->getElementType(); 4599 if (S.Context.hasSameType(ET, DestTy)) 4600 return CK_FloatingComplexToReal; 4601 S.ImpCastExprToType(Src, ET, CK_FloatingComplexToReal); 4602 return CK_FloatingCast; 4603 } 4604 case Type::STK_Bool: 4605 return CK_FloatingComplexToBoolean; 4606 case Type::STK_Integral: 4607 S.ImpCastExprToType(Src, SrcTy->getAs<ComplexType>()->getElementType(), 4608 CK_FloatingComplexToReal); 4609 return CK_FloatingToIntegral; 4610 case Type::STK_Pointer: 4611 llvm_unreachable("valid complex float->pointer cast?"); 4612 case Type::STK_MemberPointer: 4613 llvm_unreachable("member pointer type in C"); 4614 } 4615 break; 4616 4617 case Type::STK_IntegralComplex: 4618 switch (DestTy->getScalarTypeKind()) { 4619 case Type::STK_FloatingComplex: 4620 return CK_IntegralComplexToFloatingComplex; 4621 case Type::STK_IntegralComplex: 4622 return CK_IntegralComplexCast; 4623 case Type::STK_Integral: { 4624 QualType ET = SrcTy->getAs<ComplexType>()->getElementType(); 4625 if (S.Context.hasSameType(ET, DestTy)) 4626 return CK_IntegralComplexToReal; 4627 S.ImpCastExprToType(Src, ET, CK_IntegralComplexToReal); 4628 return CK_IntegralCast; 4629 } 4630 case Type::STK_Bool: 4631 return CK_IntegralComplexToBoolean; 4632 case Type::STK_Floating: 4633 S.ImpCastExprToType(Src, SrcTy->getAs<ComplexType>()->getElementType(), 4634 CK_IntegralComplexToReal); 4635 return CK_IntegralToFloating; 4636 case Type::STK_Pointer: 4637 llvm_unreachable("valid complex int->pointer cast?"); 4638 case Type::STK_MemberPointer: 4639 llvm_unreachable("member pointer type in C"); 4640 } 4641 break; 4642 } 4643 4644 llvm_unreachable("Unhandled scalar cast"); 4645 return CK_BitCast; 4646} 4647 4648/// CheckCastTypes - Check type constraints for casting between types. 4649bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, 4650 Expr *&castExpr, CastKind& Kind, ExprValueKind &VK, 4651 CXXCastPath &BasePath, bool FunctionalStyle) { 4652 if (getLangOptions().CPlusPlus) 4653 return CXXCheckCStyleCast(SourceRange(TyR.getBegin(), 4654 castExpr->getLocEnd()), 4655 castType, VK, castExpr, Kind, BasePath, 4656 FunctionalStyle); 4657 4658 // We only support r-value casts in C. 4659 VK = VK_RValue; 4660 4661 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression 4662 // type needs to be scalar. 4663 if (castType->isVoidType()) { 4664 // We don't necessarily do lvalue-to-rvalue conversions on this. 4665 IgnoredValueConversions(castExpr); 4666 4667 // Cast to void allows any expr type. 4668 Kind = CK_ToVoid; 4669 return false; 4670 } 4671 4672 DefaultFunctionArrayLvalueConversion(castExpr); 4673 4674 if (RequireCompleteType(TyR.getBegin(), castType, 4675 diag::err_typecheck_cast_to_incomplete)) 4676 return true; 4677 4678 if (!castType->isScalarType() && !castType->isVectorType()) { 4679 if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && 4680 (castType->isStructureType() || castType->isUnionType())) { 4681 // GCC struct/union extension: allow cast to self. 4682 // FIXME: Check that the cast destination type is complete. 4683 Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) 4684 << castType << castExpr->getSourceRange(); 4685 Kind = CK_NoOp; 4686 return false; 4687 } 4688 4689 if (castType->isUnionType()) { 4690 // GCC cast to union extension 4691 RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); 4692 RecordDecl::field_iterator Field, FieldEnd; 4693 for (Field = RD->field_begin(), FieldEnd = RD->field_end(); 4694 Field != FieldEnd; ++Field) { 4695 if (Context.hasSameUnqualifiedType(Field->getType(), 4696 castExpr->getType()) && 4697 !Field->isUnnamedBitfield()) { 4698 Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) 4699 << castExpr->getSourceRange(); 4700 break; 4701 } 4702 } 4703 if (Field == FieldEnd) 4704 return Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) 4705 << castExpr->getType() << castExpr->getSourceRange(); 4706 Kind = CK_ToUnion; 4707 return false; 4708 } 4709 4710 // Reject any other conversions to non-scalar types. 4711 return Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) 4712 << castType << castExpr->getSourceRange(); 4713 } 4714 4715 // The type we're casting to is known to be a scalar or vector. 4716 4717 // Require the operand to be a scalar or vector. 4718 if (!castExpr->getType()->isScalarType() && 4719 !castExpr->getType()->isVectorType()) { 4720 return Diag(castExpr->getLocStart(), 4721 diag::err_typecheck_expect_scalar_operand) 4722 << castExpr->getType() << castExpr->getSourceRange(); 4723 } 4724 4725 if (castType->isExtVectorType()) 4726 return CheckExtVectorCast(TyR, castType, castExpr, Kind); 4727 4728 if (castType->isVectorType()) 4729 return CheckVectorCast(TyR, castType, castExpr->getType(), Kind); 4730 if (castExpr->getType()->isVectorType()) 4731 return CheckVectorCast(TyR, castExpr->getType(), castType, Kind); 4732 4733 // The source and target types are both scalars, i.e. 4734 // - arithmetic types (fundamental, enum, and complex) 4735 // - all kinds of pointers 4736 // Note that member pointers were filtered out with C++, above. 4737 4738 if (isa<ObjCSelectorExpr>(castExpr)) 4739 return Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); 4740 4741 // If either type is a pointer, the other type has to be either an 4742 // integer or a pointer. 4743 if (!castType->isArithmeticType()) { 4744 QualType castExprType = castExpr->getType(); 4745 if (!castExprType->isIntegralType(Context) && 4746 castExprType->isArithmeticType()) 4747 return Diag(castExpr->getLocStart(), 4748 diag::err_cast_pointer_from_non_pointer_int) 4749 << castExprType << castExpr->getSourceRange(); 4750 } else if (!castExpr->getType()->isArithmeticType()) { 4751 if (!castType->isIntegralType(Context) && castType->isArithmeticType()) 4752 return Diag(castExpr->getLocStart(), 4753 diag::err_cast_pointer_to_non_pointer_int) 4754 << castType << castExpr->getSourceRange(); 4755 } 4756 4757 Kind = PrepareScalarCast(*this, castExpr, castType); 4758 4759 if (Kind == CK_BitCast) 4760 CheckCastAlign(castExpr, castType, TyR); 4761 4762 return false; 4763} 4764 4765bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, 4766 CastKind &Kind) { 4767 assert(VectorTy->isVectorType() && "Not a vector type!"); 4768 4769 if (Ty->isVectorType() || Ty->isIntegerType()) { 4770 if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) 4771 return Diag(R.getBegin(), 4772 Ty->isVectorType() ? 4773 diag::err_invalid_conversion_between_vectors : 4774 diag::err_invalid_conversion_between_vector_and_integer) 4775 << VectorTy << Ty << R; 4776 } else 4777 return Diag(R.getBegin(), 4778 diag::err_invalid_conversion_between_vector_and_scalar) 4779 << VectorTy << Ty << R; 4780 4781 Kind = CK_BitCast; 4782 return false; 4783} 4784 4785bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr, 4786 CastKind &Kind) { 4787 assert(DestTy->isExtVectorType() && "Not an extended vector type!"); 4788 4789 QualType SrcTy = CastExpr->getType(); 4790 4791 // If SrcTy is a VectorType, the total size must match to explicitly cast to 4792 // an ExtVectorType. 4793 if (SrcTy->isVectorType()) { 4794 if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) 4795 return Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) 4796 << DestTy << SrcTy << R; 4797 Kind = CK_BitCast; 4798 return false; 4799 } 4800 4801 // All non-pointer scalars can be cast to ExtVector type. The appropriate 4802 // conversion will take place first from scalar to elt type, and then 4803 // splat from elt type to vector. 4804 if (SrcTy->isPointerType()) 4805 return Diag(R.getBegin(), 4806 diag::err_invalid_conversion_between_vector_and_scalar) 4807 << DestTy << SrcTy << R; 4808 4809 QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); 4810 ImpCastExprToType(CastExpr, DestElemTy, 4811 PrepareScalarCast(*this, CastExpr, DestElemTy)); 4812 4813 Kind = CK_VectorSplat; 4814 return false; 4815} 4816 4817ExprResult 4818Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, ParsedType Ty, 4819 SourceLocation RParenLoc, Expr *castExpr) { 4820 assert((Ty != 0) && (castExpr != 0) && 4821 "ActOnCastExpr(): missing type or expr"); 4822 4823 TypeSourceInfo *castTInfo; 4824 QualType castType = GetTypeFromParser(Ty, &castTInfo); 4825 if (!castTInfo) 4826 castTInfo = Context.getTrivialTypeSourceInfo(castType); 4827 4828 // If the Expr being casted is a ParenListExpr, handle it specially. 4829 if (isa<ParenListExpr>(castExpr)) 4830 return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, castExpr, 4831 castTInfo); 4832 4833 return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, castExpr); 4834} 4835 4836ExprResult 4837Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, 4838 SourceLocation RParenLoc, Expr *castExpr) { 4839 CastKind Kind = CK_Invalid; 4840 ExprValueKind VK = VK_RValue; 4841 CXXCastPath BasePath; 4842 if (CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, 4843 Kind, VK, BasePath)) 4844 return ExprError(); 4845 4846 return Owned(CStyleCastExpr::Create(Context, 4847 Ty->getType().getNonLValueExprType(Context), 4848 VK, Kind, castExpr, &BasePath, Ty, 4849 LParenLoc, RParenLoc)); 4850} 4851 4852/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence 4853/// of comma binary operators. 4854ExprResult 4855Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *expr) { 4856 ParenListExpr *E = dyn_cast<ParenListExpr>(expr); 4857 if (!E) 4858 return Owned(expr); 4859 4860 ExprResult Result(E->getExpr(0)); 4861 4862 for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) 4863 Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), 4864 E->getExpr(i)); 4865 4866 if (Result.isInvalid()) return ExprError(); 4867 4868 return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); 4869} 4870 4871ExprResult 4872Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, 4873 SourceLocation RParenLoc, Expr *Op, 4874 TypeSourceInfo *TInfo) { 4875 ParenListExpr *PE = cast<ParenListExpr>(Op); 4876 QualType Ty = TInfo->getType(); 4877 bool isAltiVecLiteral = false; 4878 4879 // Check for an altivec literal, 4880 // i.e. all the elements are integer constants. 4881 if (getLangOptions().AltiVec && Ty->isVectorType()) { 4882 if (PE->getNumExprs() == 0) { 4883 Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); 4884 return ExprError(); 4885 } 4886 if (PE->getNumExprs() == 1) { 4887 if (!PE->getExpr(0)->getType()->isVectorType()) 4888 isAltiVecLiteral = true; 4889 } 4890 else 4891 isAltiVecLiteral = true; 4892 } 4893 4894 // If this is an altivec initializer, '(' type ')' '(' init, ..., init ')' 4895 // then handle it as such. 4896 if (isAltiVecLiteral) { 4897 llvm::SmallVector<Expr *, 8> initExprs; 4898 for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) 4899 initExprs.push_back(PE->getExpr(i)); 4900 4901 // FIXME: This means that pretty-printing the final AST will produce curly 4902 // braces instead of the original commas. 4903 InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, 4904 &initExprs[0], 4905 initExprs.size(), RParenLoc); 4906 E->setType(Ty); 4907 return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, E); 4908 } else { 4909 // This is not an AltiVec-style cast, so turn the ParenListExpr into a 4910 // sequence of BinOp comma operators. 4911 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Op); 4912 if (Result.isInvalid()) return ExprError(); 4913 return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Result.take()); 4914 } 4915} 4916 4917ExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, 4918 SourceLocation R, 4919 MultiExprArg Val, 4920 ParsedType TypeOfCast) { 4921 unsigned nexprs = Val.size(); 4922 Expr **exprs = reinterpret_cast<Expr**>(Val.release()); 4923 assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); 4924 Expr *expr; 4925 if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) 4926 expr = new (Context) ParenExpr(L, R, exprs[0]); 4927 else 4928 expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); 4929 return Owned(expr); 4930} 4931 4932/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. 4933/// In that case, lhs = cond. 4934/// C99 6.5.15 4935QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 4936 Expr *&SAVE, ExprValueKind &VK, 4937 ExprObjectKind &OK, 4938 SourceLocation QuestionLoc) { 4939 // If both LHS and RHS are overloaded functions, try to resolve them. 4940 if (Context.hasSameType(LHS->getType(), RHS->getType()) && 4941 LHS->getType()->isSpecificBuiltinType(BuiltinType::Overload)) { 4942 ExprResult LHSResult = CheckPlaceholderExpr(LHS, QuestionLoc); 4943 if (LHSResult.isInvalid()) 4944 return QualType(); 4945 4946 ExprResult RHSResult = CheckPlaceholderExpr(RHS, QuestionLoc); 4947 if (RHSResult.isInvalid()) 4948 return QualType(); 4949 4950 LHS = LHSResult.take(); 4951 RHS = RHSResult.take(); 4952 } 4953 4954 // C++ is sufficiently different to merit its own checker. 4955 if (getLangOptions().CPlusPlus) 4956 return CXXCheckConditionalOperands(Cond, LHS, RHS, SAVE, 4957 VK, OK, QuestionLoc); 4958 4959 VK = VK_RValue; 4960 OK = OK_Ordinary; 4961 4962 UsualUnaryConversions(Cond); 4963 if (SAVE) { 4964 SAVE = LHS = Cond; 4965 } 4966 else 4967 UsualUnaryConversions(LHS); 4968 UsualUnaryConversions(RHS); 4969 QualType CondTy = Cond->getType(); 4970 QualType LHSTy = LHS->getType(); 4971 QualType RHSTy = RHS->getType(); 4972 4973 // first, check the condition. 4974 if (!CondTy->isScalarType()) { // C99 6.5.15p2 4975 // OpenCL: Sec 6.3.i says the condition is allowed to be a vector or scalar. 4976 // Throw an error if its not either. 4977 if (getLangOptions().OpenCL) { 4978 if (!CondTy->isVectorType()) { 4979 Diag(Cond->getLocStart(), 4980 diag::err_typecheck_cond_expect_scalar_or_vector) 4981 << CondTy; 4982 return QualType(); 4983 } 4984 } 4985 else { 4986 Diag(Cond->getLocStart(), diag::err_typecheck_cond_expect_scalar) 4987 << CondTy; 4988 return QualType(); 4989 } 4990 } 4991 4992 // Now check the two expressions. 4993 if (LHSTy->isVectorType() || RHSTy->isVectorType()) 4994 return CheckVectorOperands(QuestionLoc, LHS, RHS); 4995 4996 // OpenCL: If the condition is a vector, and both operands are scalar, 4997 // attempt to implicity convert them to the vector type to act like the 4998 // built in select. 4999 if (getLangOptions().OpenCL && CondTy->isVectorType()) { 5000 // Both operands should be of scalar type. 5001 if (!LHSTy->isScalarType()) { 5002 Diag(LHS->getLocStart(), diag::err_typecheck_cond_expect_scalar) 5003 << CondTy; 5004 return QualType(); 5005 } 5006 if (!RHSTy->isScalarType()) { 5007 Diag(RHS->getLocStart(), diag::err_typecheck_cond_expect_scalar) 5008 << CondTy; 5009 return QualType(); 5010 } 5011 // Implicity convert these scalars to the type of the condition. 5012 ImpCastExprToType(LHS, CondTy, CK_IntegralCast); 5013 ImpCastExprToType(RHS, CondTy, CK_IntegralCast); 5014 } 5015 5016 // If both operands have arithmetic type, do the usual arithmetic conversions 5017 // to find a common type: C99 6.5.15p3,5. 5018 if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { 5019 UsualArithmeticConversions(LHS, RHS); 5020 return LHS->getType(); 5021 } 5022 5023 // If both operands are the same structure or union type, the result is that 5024 // type. 5025 if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 5026 if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) 5027 if (LHSRT->getDecl() == RHSRT->getDecl()) 5028 // "If both the operands have structure or union type, the result has 5029 // that type." This implies that CV qualifiers are dropped. 5030 return LHSTy.getUnqualifiedType(); 5031 // FIXME: Type of conditional expression must be complete in C mode. 5032 } 5033 5034 // C99 6.5.15p5: "If both operands have void type, the result has void type." 5035 // The following || allows only one side to be void (a GCC-ism). 5036 if (LHSTy->isVoidType() || RHSTy->isVoidType()) { 5037 if (!LHSTy->isVoidType()) 5038 Diag(RHS->getLocStart(), diag::ext_typecheck_cond_one_void) 5039 << RHS->getSourceRange(); 5040 if (!RHSTy->isVoidType()) 5041 Diag(LHS->getLocStart(), diag::ext_typecheck_cond_one_void) 5042 << LHS->getSourceRange(); 5043 ImpCastExprToType(LHS, Context.VoidTy, CK_ToVoid); 5044 ImpCastExprToType(RHS, Context.VoidTy, CK_ToVoid); 5045 return Context.VoidTy; 5046 } 5047 // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has 5048 // the type of the other operand." 5049 if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && 5050 RHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 5051 // promote the null to a pointer. 5052 ImpCastExprToType(RHS, LHSTy, CK_NullToPointer); 5053 return LHSTy; 5054 } 5055 if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && 5056 LHS->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 5057 ImpCastExprToType(LHS, RHSTy, CK_NullToPointer); 5058 return RHSTy; 5059 } 5060 5061 // All objective-c pointer type analysis is done here. 5062 QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, 5063 QuestionLoc); 5064 if (!compositeType.isNull()) 5065 return compositeType; 5066 5067 5068 // Handle block pointer types. 5069 if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { 5070 if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { 5071 if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { 5072 QualType destType = Context.getPointerType(Context.VoidTy); 5073 ImpCastExprToType(LHS, destType, CK_BitCast); 5074 ImpCastExprToType(RHS, destType, CK_BitCast); 5075 return destType; 5076 } 5077 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 5078 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5079 return QualType(); 5080 } 5081 // We have 2 block pointer types. 5082 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 5083 // Two identical block pointer types are always compatible. 5084 return LHSTy; 5085 } 5086 // The block pointer types aren't identical, continue checking. 5087 QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); 5088 QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); 5089 5090 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 5091 rhptee.getUnqualifiedType())) { 5092 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 5093 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5094 // In this situation, we assume void* type. No especially good 5095 // reason, but this is what gcc does, and we do have to pick 5096 // to get a consistent AST. 5097 QualType incompatTy = Context.getPointerType(Context.VoidTy); 5098 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 5099 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 5100 return incompatTy; 5101 } 5102 // The block pointer types are compatible. 5103 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 5104 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 5105 return LHSTy; 5106 } 5107 5108 // Check constraints for C object pointers types (C99 6.5.15p3,6). 5109 if (LHSTy->isPointerType() && RHSTy->isPointerType()) { 5110 // get the "pointed to" types 5111 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 5112 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 5113 5114 // ignore qualifiers on void (C99 6.5.15p3, clause 6) 5115 if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { 5116 // Figure out necessary qualifiers (C99 6.5.15p6) 5117 QualType destPointee 5118 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 5119 QualType destType = Context.getPointerType(destPointee); 5120 // Add qualifiers if necessary. 5121 ImpCastExprToType(LHS, destType, CK_NoOp); 5122 // Promote to void*. 5123 ImpCastExprToType(RHS, destType, CK_BitCast); 5124 return destType; 5125 } 5126 if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { 5127 QualType destPointee 5128 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 5129 QualType destType = Context.getPointerType(destPointee); 5130 // Add qualifiers if necessary. 5131 ImpCastExprToType(RHS, destType, CK_NoOp); 5132 // Promote to void*. 5133 ImpCastExprToType(LHS, destType, CK_BitCast); 5134 return destType; 5135 } 5136 5137 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 5138 // Two identical pointer types are always compatible. 5139 return LHSTy; 5140 } 5141 if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), 5142 rhptee.getUnqualifiedType())) { 5143 Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) 5144 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5145 // In this situation, we assume void* type. No especially good 5146 // reason, but this is what gcc does, and we do have to pick 5147 // to get a consistent AST. 5148 QualType incompatTy = Context.getPointerType(Context.VoidTy); 5149 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 5150 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 5151 return incompatTy; 5152 } 5153 // The pointer types are compatible. 5154 // C99 6.5.15p6: If both operands are pointers to compatible types *or* to 5155 // differently qualified versions of compatible types, the result type is 5156 // a pointer to an appropriately qualified version of the *composite* 5157 // type. 5158 // FIXME: Need to calculate the composite type. 5159 // FIXME: Need to add qualifiers 5160 ImpCastExprToType(LHS, LHSTy, CK_BitCast); 5161 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 5162 return LHSTy; 5163 } 5164 5165 // GCC compatibility: soften pointer/integer mismatch. Note that 5166 // null pointers have been filtered out by this point. 5167 if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { 5168 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 5169 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5170 ImpCastExprToType(LHS, RHSTy, CK_IntegralToPointer); 5171 return RHSTy; 5172 } 5173 if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { 5174 Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) 5175 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5176 ImpCastExprToType(RHS, LHSTy, CK_IntegralToPointer); 5177 return LHSTy; 5178 } 5179 5180 // Otherwise, the operands are not compatible. 5181 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 5182 << LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange(); 5183 return QualType(); 5184} 5185 5186/// FindCompositeObjCPointerType - Helper method to find composite type of 5187/// two objective-c pointer types of the two input expressions. 5188QualType Sema::FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS, 5189 SourceLocation QuestionLoc) { 5190 QualType LHSTy = LHS->getType(); 5191 QualType RHSTy = RHS->getType(); 5192 5193 // Handle things like Class and struct objc_class*. Here we case the result 5194 // to the pseudo-builtin, because that will be implicitly cast back to the 5195 // redefinition type if an attempt is made to access its fields. 5196 if (LHSTy->isObjCClassType() && 5197 (Context.hasSameType(RHSTy, Context.ObjCClassRedefinitionType))) { 5198 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 5199 return LHSTy; 5200 } 5201 if (RHSTy->isObjCClassType() && 5202 (Context.hasSameType(LHSTy, Context.ObjCClassRedefinitionType))) { 5203 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 5204 return RHSTy; 5205 } 5206 // And the same for struct objc_object* / id 5207 if (LHSTy->isObjCIdType() && 5208 (Context.hasSameType(RHSTy, Context.ObjCIdRedefinitionType))) { 5209 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 5210 return LHSTy; 5211 } 5212 if (RHSTy->isObjCIdType() && 5213 (Context.hasSameType(LHSTy, Context.ObjCIdRedefinitionType))) { 5214 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 5215 return RHSTy; 5216 } 5217 // And the same for struct objc_selector* / SEL 5218 if (Context.isObjCSelType(LHSTy) && 5219 (Context.hasSameType(RHSTy, Context.ObjCSelRedefinitionType))) { 5220 ImpCastExprToType(RHS, LHSTy, CK_BitCast); 5221 return LHSTy; 5222 } 5223 if (Context.isObjCSelType(RHSTy) && 5224 (Context.hasSameType(LHSTy, Context.ObjCSelRedefinitionType))) { 5225 ImpCastExprToType(LHS, RHSTy, CK_BitCast); 5226 return RHSTy; 5227 } 5228 // Check constraints for Objective-C object pointers types. 5229 if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { 5230 5231 if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { 5232 // Two identical object pointer types are always compatible. 5233 return LHSTy; 5234 } 5235 const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); 5236 const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); 5237 QualType compositeType = LHSTy; 5238 5239 // If both operands are interfaces and either operand can be 5240 // assigned to the other, use that type as the composite 5241 // type. This allows 5242 // xxx ? (A*) a : (B*) b 5243 // where B is a subclass of A. 5244 // 5245 // Additionally, as for assignment, if either type is 'id' 5246 // allow silent coercion. Finally, if the types are 5247 // incompatible then make sure to use 'id' as the composite 5248 // type so the result is acceptable for sending messages to. 5249 5250 // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. 5251 // It could return the composite type. 5252 if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { 5253 compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; 5254 } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { 5255 compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; 5256 } else if ((LHSTy->isObjCQualifiedIdType() || 5257 RHSTy->isObjCQualifiedIdType()) && 5258 Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { 5259 // Need to handle "id<xx>" explicitly. 5260 // GCC allows qualified id and any Objective-C type to devolve to 5261 // id. Currently localizing to here until clear this should be 5262 // part of ObjCQualifiedIdTypesAreCompatible. 5263 compositeType = Context.getObjCIdType(); 5264 } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { 5265 compositeType = Context.getObjCIdType(); 5266 } else if (!(compositeType = 5267 Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) 5268 ; 5269 else { 5270 Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) 5271 << LHSTy << RHSTy 5272 << LHS->getSourceRange() << RHS->getSourceRange(); 5273 QualType incompatTy = Context.getObjCIdType(); 5274 ImpCastExprToType(LHS, incompatTy, CK_BitCast); 5275 ImpCastExprToType(RHS, incompatTy, CK_BitCast); 5276 return incompatTy; 5277 } 5278 // The object pointer types are compatible. 5279 ImpCastExprToType(LHS, compositeType, CK_BitCast); 5280 ImpCastExprToType(RHS, compositeType, CK_BitCast); 5281 return compositeType; 5282 } 5283 // Check Objective-C object pointer types and 'void *' 5284 if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { 5285 QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); 5286 QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 5287 QualType destPointee 5288 = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); 5289 QualType destType = Context.getPointerType(destPointee); 5290 // Add qualifiers if necessary. 5291 ImpCastExprToType(LHS, destType, CK_NoOp); 5292 // Promote to void*. 5293 ImpCastExprToType(RHS, destType, CK_BitCast); 5294 return destType; 5295 } 5296 if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { 5297 QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); 5298 QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); 5299 QualType destPointee 5300 = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); 5301 QualType destType = Context.getPointerType(destPointee); 5302 // Add qualifiers if necessary. 5303 ImpCastExprToType(RHS, destType, CK_NoOp); 5304 // Promote to void*. 5305 ImpCastExprToType(LHS, destType, CK_BitCast); 5306 return destType; 5307 } 5308 return QualType(); 5309} 5310 5311/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null 5312/// in the case of a the GNU conditional expr extension. 5313ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, 5314 SourceLocation ColonLoc, 5315 Expr *CondExpr, Expr *LHSExpr, 5316 Expr *RHSExpr) { 5317 // If this is the gnu "x ?: y" extension, analyze the types as though the LHS 5318 // was the condition. 5319 bool isLHSNull = LHSExpr == 0; 5320 Expr *SAVEExpr = 0; 5321 if (isLHSNull) { 5322 LHSExpr = SAVEExpr = CondExpr; 5323 } 5324 5325 ExprValueKind VK = VK_RValue; 5326 ExprObjectKind OK = OK_Ordinary; 5327 QualType result = CheckConditionalOperands(CondExpr, LHSExpr, RHSExpr, 5328 SAVEExpr, VK, OK, QuestionLoc); 5329 if (result.isNull()) 5330 return ExprError(); 5331 5332 return Owned(new (Context) ConditionalOperator(CondExpr, QuestionLoc, 5333 LHSExpr, ColonLoc, 5334 RHSExpr, SAVEExpr, 5335 result, VK, OK)); 5336} 5337 5338// CheckPointerTypesForAssignment - This is a very tricky routine (despite 5339// being closely modeled after the C99 spec:-). The odd characteristic of this 5340// routine is it effectively iqnores the qualifiers on the top level pointee. 5341// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. 5342// FIXME: add a couple examples in this comment. 5343Sema::AssignConvertType 5344Sema::CheckPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 5345 QualType lhptee, rhptee; 5346 5347 if ((lhsType->isObjCClassType() && 5348 (Context.hasSameType(rhsType, Context.ObjCClassRedefinitionType))) || 5349 (rhsType->isObjCClassType() && 5350 (Context.hasSameType(lhsType, Context.ObjCClassRedefinitionType)))) { 5351 return Compatible; 5352 } 5353 5354 // get the "pointed to" type (ignoring qualifiers at the top level) 5355 lhptee = lhsType->getAs<PointerType>()->getPointeeType(); 5356 rhptee = rhsType->getAs<PointerType>()->getPointeeType(); 5357 5358 // make sure we operate on the canonical type 5359 lhptee = Context.getCanonicalType(lhptee); 5360 rhptee = Context.getCanonicalType(rhptee); 5361 5362 AssignConvertType ConvTy = Compatible; 5363 5364 // C99 6.5.16.1p1: This following citation is common to constraints 5365 // 3 & 4 (below). ...and the type *pointed to* by the left has all the 5366 // qualifiers of the type *pointed to* by the right; 5367 // FIXME: Handle ExtQualType 5368 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 5369 ConvTy = CompatiblePointerDiscardsQualifiers; 5370 5371 // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or 5372 // incomplete type and the other is a pointer to a qualified or unqualified 5373 // version of void... 5374 if (lhptee->isVoidType()) { 5375 if (rhptee->isIncompleteOrObjectType()) 5376 return ConvTy; 5377 5378 // As an extension, we allow cast to/from void* to function pointer. 5379 assert(rhptee->isFunctionType()); 5380 return FunctionVoidPointer; 5381 } 5382 5383 if (rhptee->isVoidType()) { 5384 if (lhptee->isIncompleteOrObjectType()) 5385 return ConvTy; 5386 5387 // As an extension, we allow cast to/from void* to function pointer. 5388 assert(lhptee->isFunctionType()); 5389 return FunctionVoidPointer; 5390 } 5391 // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or 5392 // unqualified versions of compatible types, ... 5393 lhptee = lhptee.getUnqualifiedType(); 5394 rhptee = rhptee.getUnqualifiedType(); 5395 if (!Context.typesAreCompatible(lhptee, rhptee)) { 5396 // Check if the pointee types are compatible ignoring the sign. 5397 // We explicitly check for char so that we catch "char" vs 5398 // "unsigned char" on systems where "char" is unsigned. 5399 if (lhptee->isCharType()) 5400 lhptee = Context.UnsignedCharTy; 5401 else if (lhptee->hasSignedIntegerRepresentation()) 5402 lhptee = Context.getCorrespondingUnsignedType(lhptee); 5403 5404 if (rhptee->isCharType()) 5405 rhptee = Context.UnsignedCharTy; 5406 else if (rhptee->hasSignedIntegerRepresentation()) 5407 rhptee = Context.getCorrespondingUnsignedType(rhptee); 5408 5409 if (lhptee == rhptee) { 5410 // Types are compatible ignoring the sign. Qualifier incompatibility 5411 // takes priority over sign incompatibility because the sign 5412 // warning can be disabled. 5413 if (ConvTy != Compatible) 5414 return ConvTy; 5415 return IncompatiblePointerSign; 5416 } 5417 5418 // If we are a multi-level pointer, it's possible that our issue is simply 5419 // one of qualification - e.g. char ** -> const char ** is not allowed. If 5420 // the eventual target type is the same and the pointers have the same 5421 // level of indirection, this must be the issue. 5422 if (lhptee->isPointerType() && rhptee->isPointerType()) { 5423 do { 5424 lhptee = lhptee->getAs<PointerType>()->getPointeeType(); 5425 rhptee = rhptee->getAs<PointerType>()->getPointeeType(); 5426 5427 lhptee = Context.getCanonicalType(lhptee); 5428 rhptee = Context.getCanonicalType(rhptee); 5429 } while (lhptee->isPointerType() && rhptee->isPointerType()); 5430 5431 if (Context.hasSameUnqualifiedType(lhptee, rhptee)) 5432 return IncompatibleNestedPointerQualifiers; 5433 } 5434 5435 // General pointer incompatibility takes priority over qualifiers. 5436 return IncompatiblePointer; 5437 } 5438 return ConvTy; 5439} 5440 5441/// CheckBlockPointerTypesForAssignment - This routine determines whether two 5442/// block pointer types are compatible or whether a block and normal pointer 5443/// are compatible. It is more restrict than comparing two function pointer 5444// types. 5445Sema::AssignConvertType 5446Sema::CheckBlockPointerTypesForAssignment(QualType lhsType, 5447 QualType rhsType) { 5448 QualType lhptee, rhptee; 5449 5450 // get the "pointed to" type (ignoring qualifiers at the top level) 5451 lhptee = lhsType->getAs<BlockPointerType>()->getPointeeType(); 5452 rhptee = rhsType->getAs<BlockPointerType>()->getPointeeType(); 5453 5454 // make sure we operate on the canonical type 5455 lhptee = Context.getCanonicalType(lhptee); 5456 rhptee = Context.getCanonicalType(rhptee); 5457 5458 AssignConvertType ConvTy = Compatible; 5459 5460 // For blocks we enforce that qualifiers are identical. 5461 if (lhptee.getLocalCVRQualifiers() != rhptee.getLocalCVRQualifiers()) 5462 ConvTy = CompatiblePointerDiscardsQualifiers; 5463 5464 if (!getLangOptions().CPlusPlus) { 5465 if (!Context.typesAreBlockPointerCompatible(lhsType, rhsType)) 5466 return IncompatibleBlockPointer; 5467 } 5468 else if (!Context.typesAreCompatible(lhptee, rhptee)) 5469 return IncompatibleBlockPointer; 5470 return ConvTy; 5471} 5472 5473/// CheckObjCPointerTypesForAssignment - Compares two objective-c pointer types 5474/// for assignment compatibility. 5475Sema::AssignConvertType 5476Sema::CheckObjCPointerTypesForAssignment(QualType lhsType, QualType rhsType) { 5477 if (lhsType->isObjCBuiltinType()) { 5478 // Class is not compatible with ObjC object pointers. 5479 if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && 5480 !rhsType->isObjCQualifiedClassType()) 5481 return IncompatiblePointer; 5482 return Compatible; 5483 } 5484 if (rhsType->isObjCBuiltinType()) { 5485 // Class is not compatible with ObjC object pointers. 5486 if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && 5487 !lhsType->isObjCQualifiedClassType()) 5488 return IncompatiblePointer; 5489 return Compatible; 5490 } 5491 QualType lhptee = 5492 lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 5493 QualType rhptee = 5494 rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); 5495 // make sure we operate on the canonical type 5496 lhptee = Context.getCanonicalType(lhptee); 5497 rhptee = Context.getCanonicalType(rhptee); 5498 if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) 5499 return CompatiblePointerDiscardsQualifiers; 5500 5501 if (Context.typesAreCompatible(lhsType, rhsType)) 5502 return Compatible; 5503 if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) 5504 return IncompatibleObjCQualifiedId; 5505 return IncompatiblePointer; 5506} 5507 5508Sema::AssignConvertType 5509Sema::CheckAssignmentConstraints(QualType lhsType, QualType rhsType) { 5510 // Fake up an opaque expression. We don't actually care about what 5511 // cast operations are required, so if CheckAssignmentConstraints 5512 // adds casts to this they'll be wasted, but fortunately that doesn't 5513 // usually happen on valid code. 5514 OpaqueValueExpr rhs(rhsType, VK_RValue); 5515 Expr *rhsPtr = &rhs; 5516 CastKind K = CK_Invalid; 5517 5518 return CheckAssignmentConstraints(lhsType, rhsPtr, K); 5519} 5520 5521/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently 5522/// has code to accommodate several GCC extensions when type checking 5523/// pointers. Here are some objectionable examples that GCC considers warnings: 5524/// 5525/// int a, *pint; 5526/// short *pshort; 5527/// struct foo *pfoo; 5528/// 5529/// pint = pshort; // warning: assignment from incompatible pointer type 5530/// a = pint; // warning: assignment makes integer from pointer without a cast 5531/// pint = a; // warning: assignment makes pointer from integer without a cast 5532/// pint = pfoo; // warning: assignment from incompatible pointer type 5533/// 5534/// As a result, the code for dealing with pointers is more complex than the 5535/// C99 spec dictates. 5536/// 5537/// Sets 'Kind' for any result kind except Incompatible. 5538Sema::AssignConvertType 5539Sema::CheckAssignmentConstraints(QualType lhsType, Expr *&rhs, 5540 CastKind &Kind) { 5541 QualType rhsType = rhs->getType(); 5542 5543 // Get canonical types. We're not formatting these types, just comparing 5544 // them. 5545 lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); 5546 rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); 5547 5548 if (lhsType == rhsType) { 5549 Kind = CK_NoOp; 5550 return Compatible; // Common case: fast path an exact match. 5551 } 5552 5553 if ((lhsType->isObjCClassType() && 5554 (Context.hasSameType(rhsType, Context.ObjCClassRedefinitionType))) || 5555 (rhsType->isObjCClassType() && 5556 (Context.hasSameType(lhsType, Context.ObjCClassRedefinitionType)))) { 5557 Kind = CK_BitCast; 5558 return Compatible; 5559 } 5560 5561 // If the left-hand side is a reference type, then we are in a 5562 // (rare!) case where we've allowed the use of references in C, 5563 // e.g., as a parameter type in a built-in function. In this case, 5564 // just make sure that the type referenced is compatible with the 5565 // right-hand side type. The caller is responsible for adjusting 5566 // lhsType so that the resulting expression does not have reference 5567 // type. 5568 if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { 5569 if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) { 5570 Kind = CK_LValueBitCast; 5571 return Compatible; 5572 } 5573 return Incompatible; 5574 } 5575 // Allow scalar to ExtVector assignments, and assignments of an ExtVector type 5576 // to the same ExtVector type. 5577 if (lhsType->isExtVectorType()) { 5578 if (rhsType->isExtVectorType()) 5579 return Incompatible; 5580 if (rhsType->isArithmeticType()) { 5581 // CK_VectorSplat does T -> vector T, so first cast to the 5582 // element type. 5583 QualType elType = cast<ExtVectorType>(lhsType)->getElementType(); 5584 if (elType != rhsType) { 5585 Kind = PrepareScalarCast(*this, rhs, elType); 5586 ImpCastExprToType(rhs, elType, Kind); 5587 } 5588 Kind = CK_VectorSplat; 5589 return Compatible; 5590 } 5591 } 5592 5593 if (lhsType->isVectorType() || rhsType->isVectorType()) { 5594 if (lhsType->isVectorType() && rhsType->isVectorType()) { 5595 // Allow assignments of an AltiVec vector type to an equivalent GCC 5596 // vector type and vice versa 5597 if (Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5598 Kind = CK_BitCast; 5599 return Compatible; 5600 } 5601 5602 // If we are allowing lax vector conversions, and LHS and RHS are both 5603 // vectors, the total size only needs to be the same. This is a bitcast; 5604 // no bits are changed but the result type is different. 5605 if (getLangOptions().LaxVectorConversions && 5606 (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) { 5607 Kind = CK_BitCast; 5608 return IncompatibleVectors; 5609 } 5610 } 5611 return Incompatible; 5612 } 5613 5614 if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && 5615 !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) { 5616 Kind = PrepareScalarCast(*this, rhs, lhsType); 5617 return Compatible; 5618 } 5619 5620 if (isa<PointerType>(lhsType)) { 5621 if (rhsType->isIntegerType()) { 5622 Kind = CK_IntegralToPointer; // FIXME: null? 5623 return IntToPointer; 5624 } 5625 5626 if (isa<PointerType>(rhsType)) { 5627 Kind = CK_BitCast; 5628 return CheckPointerTypesForAssignment(lhsType, rhsType); 5629 } 5630 5631 // In general, C pointers are not compatible with ObjC object pointers. 5632 if (isa<ObjCObjectPointerType>(rhsType)) { 5633 Kind = CK_AnyPointerToObjCPointerCast; 5634 if (lhsType->isVoidPointerType()) // an exception to the rule. 5635 return Compatible; 5636 return IncompatiblePointer; 5637 } 5638 if (rhsType->getAs<BlockPointerType>()) { 5639 if (lhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 5640 Kind = CK_BitCast; 5641 return Compatible; 5642 } 5643 5644 // Treat block pointers as objects. 5645 if (getLangOptions().ObjC1 && lhsType->isObjCIdType()) { 5646 Kind = CK_AnyPointerToObjCPointerCast; 5647 return Compatible; 5648 } 5649 } 5650 return Incompatible; 5651 } 5652 5653 if (isa<BlockPointerType>(lhsType)) { 5654 if (rhsType->isIntegerType()) { 5655 Kind = CK_IntegralToPointer; // FIXME: null 5656 return IntToBlockPointer; 5657 } 5658 5659 Kind = CK_AnyPointerToObjCPointerCast; 5660 5661 // Treat block pointers as objects. 5662 if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) 5663 return Compatible; 5664 5665 if (rhsType->isBlockPointerType()) 5666 return CheckBlockPointerTypesForAssignment(lhsType, rhsType); 5667 5668 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) 5669 if (RHSPT->getPointeeType()->isVoidType()) 5670 return Compatible; 5671 5672 return Incompatible; 5673 } 5674 5675 if (isa<ObjCObjectPointerType>(lhsType)) { 5676 if (rhsType->isIntegerType()) { 5677 Kind = CK_IntegralToPointer; // FIXME: null 5678 return IntToPointer; 5679 } 5680 5681 Kind = CK_BitCast; 5682 5683 // In general, C pointers are not compatible with ObjC object pointers. 5684 if (isa<PointerType>(rhsType)) { 5685 if (rhsType->isVoidPointerType()) // an exception to the rule. 5686 return Compatible; 5687 return IncompatiblePointer; 5688 } 5689 if (rhsType->isObjCObjectPointerType()) { 5690 return CheckObjCPointerTypesForAssignment(lhsType, rhsType); 5691 } 5692 if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) { 5693 if (RHSPT->getPointeeType()->isVoidType()) 5694 return Compatible; 5695 } 5696 // Treat block pointers as objects. 5697 if (rhsType->isBlockPointerType()) 5698 return Compatible; 5699 return Incompatible; 5700 } 5701 if (isa<PointerType>(rhsType)) { 5702 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 5703 if (lhsType == Context.BoolTy) { 5704 Kind = CK_PointerToBoolean; 5705 return Compatible; 5706 } 5707 5708 if (lhsType->isIntegerType()) { 5709 Kind = CK_PointerToIntegral; 5710 return PointerToInt; 5711 } 5712 5713 if (isa<BlockPointerType>(lhsType) && 5714 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 5715 Kind = CK_AnyPointerToBlockPointerCast; 5716 return Compatible; 5717 } 5718 return Incompatible; 5719 } 5720 if (isa<ObjCObjectPointerType>(rhsType)) { 5721 // C99 6.5.16.1p1: the left operand is _Bool and the right is a pointer. 5722 if (lhsType == Context.BoolTy) { 5723 Kind = CK_PointerToBoolean; 5724 return Compatible; 5725 } 5726 5727 if (lhsType->isIntegerType()) { 5728 Kind = CK_PointerToIntegral; 5729 return PointerToInt; 5730 } 5731 5732 Kind = CK_BitCast; 5733 5734 // In general, C pointers are not compatible with ObjC object pointers. 5735 if (isa<PointerType>(lhsType)) { 5736 if (lhsType->isVoidPointerType()) // an exception to the rule. 5737 return Compatible; 5738 return IncompatiblePointer; 5739 } 5740 if (isa<BlockPointerType>(lhsType) && 5741 rhsType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 5742 Kind = CK_AnyPointerToBlockPointerCast; 5743 return Compatible; 5744 } 5745 return Incompatible; 5746 } 5747 5748 if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { 5749 if (Context.typesAreCompatible(lhsType, rhsType)) { 5750 Kind = CK_NoOp; 5751 return Compatible; 5752 } 5753 } 5754 return Incompatible; 5755} 5756 5757/// \brief Constructs a transparent union from an expression that is 5758/// used to initialize the transparent union. 5759static void ConstructTransparentUnion(ASTContext &C, Expr *&E, 5760 QualType UnionType, FieldDecl *Field) { 5761 // Build an initializer list that designates the appropriate member 5762 // of the transparent union. 5763 InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), 5764 &E, 1, 5765 SourceLocation()); 5766 Initializer->setType(UnionType); 5767 Initializer->setInitializedFieldInUnion(Field); 5768 5769 // Build a compound literal constructing a value of the transparent 5770 // union type from this initializer list. 5771 TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); 5772 E = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, 5773 VK_RValue, Initializer, false); 5774} 5775 5776Sema::AssignConvertType 5777Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) { 5778 QualType FromType = rExpr->getType(); 5779 5780 // If the ArgType is a Union type, we want to handle a potential 5781 // transparent_union GCC extension. 5782 const RecordType *UT = ArgType->getAsUnionType(); 5783 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 5784 return Incompatible; 5785 5786 // The field to initialize within the transparent union. 5787 RecordDecl *UD = UT->getDecl(); 5788 FieldDecl *InitField = 0; 5789 // It's compatible if the expression matches any of the fields. 5790 for (RecordDecl::field_iterator it = UD->field_begin(), 5791 itend = UD->field_end(); 5792 it != itend; ++it) { 5793 if (it->getType()->isPointerType()) { 5794 // If the transparent union contains a pointer type, we allow: 5795 // 1) void pointer 5796 // 2) null pointer constant 5797 if (FromType->isPointerType()) 5798 if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 5799 ImpCastExprToType(rExpr, it->getType(), CK_BitCast); 5800 InitField = *it; 5801 break; 5802 } 5803 5804 if (rExpr->isNullPointerConstant(Context, 5805 Expr::NPC_ValueDependentIsNull)) { 5806 ImpCastExprToType(rExpr, it->getType(), CK_NullToPointer); 5807 InitField = *it; 5808 break; 5809 } 5810 } 5811 5812 Expr *rhs = rExpr; 5813 CastKind Kind = CK_Invalid; 5814 if (CheckAssignmentConstraints(it->getType(), rhs, Kind) 5815 == Compatible) { 5816 ImpCastExprToType(rhs, it->getType(), Kind); 5817 rExpr = rhs; 5818 InitField = *it; 5819 break; 5820 } 5821 } 5822 5823 if (!InitField) 5824 return Incompatible; 5825 5826 ConstructTransparentUnion(Context, rExpr, ArgType, InitField); 5827 return Compatible; 5828} 5829 5830Sema::AssignConvertType 5831Sema::CheckSingleAssignmentConstraints(QualType lhsType, Expr *&rExpr) { 5832 if (getLangOptions().CPlusPlus) { 5833 if (!lhsType->isRecordType()) { 5834 // C++ 5.17p3: If the left operand is not of class type, the 5835 // expression is implicitly converted (C++ 4) to the 5836 // cv-unqualified type of the left operand. 5837 if (PerformImplicitConversion(rExpr, lhsType.getUnqualifiedType(), 5838 AA_Assigning)) 5839 return Incompatible; 5840 return Compatible; 5841 } 5842 5843 // FIXME: Currently, we fall through and treat C++ classes like C 5844 // structures. 5845 } 5846 5847 // C99 6.5.16.1p1: the left operand is a pointer and the right is 5848 // a null pointer constant. 5849 if ((lhsType->isPointerType() || 5850 lhsType->isObjCObjectPointerType() || 5851 lhsType->isBlockPointerType()) 5852 && rExpr->isNullPointerConstant(Context, 5853 Expr::NPC_ValueDependentIsNull)) { 5854 ImpCastExprToType(rExpr, lhsType, CK_NullToPointer); 5855 return Compatible; 5856 } 5857 5858 // This check seems unnatural, however it is necessary to ensure the proper 5859 // conversion of functions/arrays. If the conversion were done for all 5860 // DeclExpr's (created by ActOnIdExpression), it would mess up the unary 5861 // expressions that suppress this implicit conversion (&, sizeof). 5862 // 5863 // Suppress this for references: C++ 8.5.3p5. 5864 if (!lhsType->isReferenceType()) 5865 DefaultFunctionArrayLvalueConversion(rExpr); 5866 5867 CastKind Kind = CK_Invalid; 5868 Sema::AssignConvertType result = 5869 CheckAssignmentConstraints(lhsType, rExpr, Kind); 5870 5871 // C99 6.5.16.1p2: The value of the right operand is converted to the 5872 // type of the assignment expression. 5873 // CheckAssignmentConstraints allows the left-hand side to be a reference, 5874 // so that we can use references in built-in functions even in C. 5875 // The getNonReferenceType() call makes sure that the resulting expression 5876 // does not have reference type. 5877 if (result != Incompatible && rExpr->getType() != lhsType) 5878 ImpCastExprToType(rExpr, lhsType.getNonLValueExprType(Context), Kind); 5879 return result; 5880} 5881 5882QualType Sema::InvalidOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5883 Diag(Loc, diag::err_typecheck_invalid_operands) 5884 << lex->getType() << rex->getType() 5885 << lex->getSourceRange() << rex->getSourceRange(); 5886 return QualType(); 5887} 5888 5889QualType Sema::CheckVectorOperands(SourceLocation Loc, Expr *&lex, Expr *&rex) { 5890 // For conversion purposes, we ignore any qualifiers. 5891 // For example, "const float" and "float" are equivalent. 5892 QualType lhsType = 5893 Context.getCanonicalType(lex->getType()).getUnqualifiedType(); 5894 QualType rhsType = 5895 Context.getCanonicalType(rex->getType()).getUnqualifiedType(); 5896 5897 // If the vector types are identical, return. 5898 if (lhsType == rhsType) 5899 return lhsType; 5900 5901 // Handle the case of a vector & extvector type of the same size and element 5902 // type. It would be nice if we only had one vector type someday. 5903 if (getLangOptions().LaxVectorConversions) { 5904 if (const VectorType *LV = lhsType->getAs<VectorType>()) { 5905 if (const VectorType *RV = rhsType->getAs<VectorType>()) { 5906 if (LV->getElementType() == RV->getElementType() && 5907 LV->getNumElements() == RV->getNumElements()) { 5908 if (lhsType->isExtVectorType()) { 5909 ImpCastExprToType(rex, lhsType, CK_BitCast); 5910 return lhsType; 5911 } 5912 5913 ImpCastExprToType(lex, rhsType, CK_BitCast); 5914 return rhsType; 5915 } else if (Context.getTypeSize(lhsType) ==Context.getTypeSize(rhsType)){ 5916 // If we are allowing lax vector conversions, and LHS and RHS are both 5917 // vectors, the total size only needs to be the same. This is a 5918 // bitcast; no bits are changed but the result type is different. 5919 ImpCastExprToType(rex, lhsType, CK_BitCast); 5920 return lhsType; 5921 } 5922 } 5923 } 5924 } 5925 5926 // Handle the case of equivalent AltiVec and GCC vector types 5927 if (lhsType->isVectorType() && rhsType->isVectorType() && 5928 Context.areCompatibleVectorTypes(lhsType, rhsType)) { 5929 ImpCastExprToType(lex, rhsType, CK_BitCast); 5930 return rhsType; 5931 } 5932 5933 // Canonicalize the ExtVector to the LHS, remember if we swapped so we can 5934 // swap back (so that we don't reverse the inputs to a subtract, for instance. 5935 bool swapped = false; 5936 if (rhsType->isExtVectorType()) { 5937 swapped = true; 5938 std::swap(rex, lex); 5939 std::swap(rhsType, lhsType); 5940 } 5941 5942 // Handle the case of an ext vector and scalar. 5943 if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { 5944 QualType EltTy = LV->getElementType(); 5945 if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { 5946 int order = Context.getIntegerTypeOrder(EltTy, rhsType); 5947 if (order > 0) 5948 ImpCastExprToType(rex, EltTy, CK_IntegralCast); 5949 if (order >= 0) { 5950 ImpCastExprToType(rex, lhsType, CK_VectorSplat); 5951 if (swapped) std::swap(rex, lex); 5952 return lhsType; 5953 } 5954 } 5955 if (EltTy->isRealFloatingType() && rhsType->isScalarType() && 5956 rhsType->isRealFloatingType()) { 5957 int order = Context.getFloatingTypeOrder(EltTy, rhsType); 5958 if (order > 0) 5959 ImpCastExprToType(rex, EltTy, CK_FloatingCast); 5960 if (order >= 0) { 5961 ImpCastExprToType(rex, lhsType, CK_VectorSplat); 5962 if (swapped) std::swap(rex, lex); 5963 return lhsType; 5964 } 5965 } 5966 } 5967 5968 // Vectors of different size or scalar and non-ext-vector are errors. 5969 Diag(Loc, diag::err_typecheck_vector_not_convertable) 5970 << lex->getType() << rex->getType() 5971 << lex->getSourceRange() << rex->getSourceRange(); 5972 return QualType(); 5973} 5974 5975QualType Sema::CheckMultiplyDivideOperands( 5976 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { 5977 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 5978 return CheckVectorOperands(Loc, lex, rex); 5979 5980 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 5981 5982 if (!lex->getType()->isArithmeticType() || 5983 !rex->getType()->isArithmeticType()) 5984 return InvalidOperands(Loc, lex, rex); 5985 5986 // Check for division by zero. 5987 if (isDiv && 5988 rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 5989 DiagRuntimeBehavior(Loc, PDiag(diag::warn_division_by_zero) 5990 << rex->getSourceRange()); 5991 5992 return compType; 5993} 5994 5995QualType Sema::CheckRemainderOperands( 5996 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 5997 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 5998 if (lex->getType()->hasIntegerRepresentation() && 5999 rex->getType()->hasIntegerRepresentation()) 6000 return CheckVectorOperands(Loc, lex, rex); 6001 return InvalidOperands(Loc, lex, rex); 6002 } 6003 6004 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 6005 6006 if (!lex->getType()->isIntegerType() || !rex->getType()->isIntegerType()) 6007 return InvalidOperands(Loc, lex, rex); 6008 6009 // Check for remainder by zero. 6010 if (rex->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 6011 DiagRuntimeBehavior(Loc, PDiag(diag::warn_remainder_by_zero) 6012 << rex->getSourceRange()); 6013 6014 return compType; 6015} 6016 6017QualType Sema::CheckAdditionOperands( // C99 6.5.6 6018 Expr *&lex, Expr *&rex, SourceLocation Loc, QualType* CompLHSTy) { 6019 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 6020 QualType compType = CheckVectorOperands(Loc, lex, rex); 6021 if (CompLHSTy) *CompLHSTy = compType; 6022 return compType; 6023 } 6024 6025 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 6026 6027 // handle the common case first (both operands are arithmetic). 6028 if (lex->getType()->isArithmeticType() && 6029 rex->getType()->isArithmeticType()) { 6030 if (CompLHSTy) *CompLHSTy = compType; 6031 return compType; 6032 } 6033 6034 // Put any potential pointer into PExp 6035 Expr* PExp = lex, *IExp = rex; 6036 if (IExp->getType()->isAnyPointerType()) 6037 std::swap(PExp, IExp); 6038 6039 if (PExp->getType()->isAnyPointerType()) { 6040 6041 if (IExp->getType()->isIntegerType()) { 6042 QualType PointeeTy = PExp->getType()->getPointeeType(); 6043 6044 // Check for arithmetic on pointers to incomplete types. 6045 if (PointeeTy->isVoidType()) { 6046 if (getLangOptions().CPlusPlus) { 6047 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 6048 << lex->getSourceRange() << rex->getSourceRange(); 6049 return QualType(); 6050 } 6051 6052 // GNU extension: arithmetic on pointer to void 6053 Diag(Loc, diag::ext_gnu_void_ptr) 6054 << lex->getSourceRange() << rex->getSourceRange(); 6055 } else if (PointeeTy->isFunctionType()) { 6056 if (getLangOptions().CPlusPlus) { 6057 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 6058 << lex->getType() << lex->getSourceRange(); 6059 return QualType(); 6060 } 6061 6062 // GNU extension: arithmetic on pointer to function 6063 Diag(Loc, diag::ext_gnu_ptr_func_arith) 6064 << lex->getType() << lex->getSourceRange(); 6065 } else { 6066 // Check if we require a complete type. 6067 if (((PExp->getType()->isPointerType() && 6068 !PExp->getType()->isDependentType()) || 6069 PExp->getType()->isObjCObjectPointerType()) && 6070 RequireCompleteType(Loc, PointeeTy, 6071 PDiag(diag::err_typecheck_arithmetic_incomplete_type) 6072 << PExp->getSourceRange() 6073 << PExp->getType())) 6074 return QualType(); 6075 } 6076 // Diagnose bad cases where we step over interface counts. 6077 if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6078 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 6079 << PointeeTy << PExp->getSourceRange(); 6080 return QualType(); 6081 } 6082 6083 if (CompLHSTy) { 6084 QualType LHSTy = Context.isPromotableBitField(lex); 6085 if (LHSTy.isNull()) { 6086 LHSTy = lex->getType(); 6087 if (LHSTy->isPromotableIntegerType()) 6088 LHSTy = Context.getPromotedIntegerType(LHSTy); 6089 } 6090 *CompLHSTy = LHSTy; 6091 } 6092 return PExp->getType(); 6093 } 6094 } 6095 6096 return InvalidOperands(Loc, lex, rex); 6097} 6098 6099// C99 6.5.6 6100QualType Sema::CheckSubtractionOperands(Expr *&lex, Expr *&rex, 6101 SourceLocation Loc, QualType* CompLHSTy) { 6102 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 6103 QualType compType = CheckVectorOperands(Loc, lex, rex); 6104 if (CompLHSTy) *CompLHSTy = compType; 6105 return compType; 6106 } 6107 6108 QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); 6109 6110 // Enforce type constraints: C99 6.5.6p3. 6111 6112 // Handle the common case first (both operands are arithmetic). 6113 if (lex->getType()->isArithmeticType() 6114 && rex->getType()->isArithmeticType()) { 6115 if (CompLHSTy) *CompLHSTy = compType; 6116 return compType; 6117 } 6118 6119 // Either ptr - int or ptr - ptr. 6120 if (lex->getType()->isAnyPointerType()) { 6121 QualType lpointee = lex->getType()->getPointeeType(); 6122 6123 // The LHS must be an completely-defined object type. 6124 6125 bool ComplainAboutVoid = false; 6126 Expr *ComplainAboutFunc = 0; 6127 if (lpointee->isVoidType()) { 6128 if (getLangOptions().CPlusPlus) { 6129 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 6130 << lex->getSourceRange() << rex->getSourceRange(); 6131 return QualType(); 6132 } 6133 6134 // GNU C extension: arithmetic on pointer to void 6135 ComplainAboutVoid = true; 6136 } else if (lpointee->isFunctionType()) { 6137 if (getLangOptions().CPlusPlus) { 6138 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 6139 << lex->getType() << lex->getSourceRange(); 6140 return QualType(); 6141 } 6142 6143 // GNU C extension: arithmetic on pointer to function 6144 ComplainAboutFunc = lex; 6145 } else if (!lpointee->isDependentType() && 6146 RequireCompleteType(Loc, lpointee, 6147 PDiag(diag::err_typecheck_sub_ptr_object) 6148 << lex->getSourceRange() 6149 << lex->getType())) 6150 return QualType(); 6151 6152 // Diagnose bad cases where we step over interface counts. 6153 if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { 6154 Diag(Loc, diag::err_arithmetic_nonfragile_interface) 6155 << lpointee << lex->getSourceRange(); 6156 return QualType(); 6157 } 6158 6159 // The result type of a pointer-int computation is the pointer type. 6160 if (rex->getType()->isIntegerType()) { 6161 if (ComplainAboutVoid) 6162 Diag(Loc, diag::ext_gnu_void_ptr) 6163 << lex->getSourceRange() << rex->getSourceRange(); 6164 if (ComplainAboutFunc) 6165 Diag(Loc, diag::ext_gnu_ptr_func_arith) 6166 << ComplainAboutFunc->getType() 6167 << ComplainAboutFunc->getSourceRange(); 6168 6169 if (CompLHSTy) *CompLHSTy = lex->getType(); 6170 return lex->getType(); 6171 } 6172 6173 // Handle pointer-pointer subtractions. 6174 if (const PointerType *RHSPTy = rex->getType()->getAs<PointerType>()) { 6175 QualType rpointee = RHSPTy->getPointeeType(); 6176 6177 // RHS must be a completely-type object type. 6178 // Handle the GNU void* extension. 6179 if (rpointee->isVoidType()) { 6180 if (getLangOptions().CPlusPlus) { 6181 Diag(Loc, diag::err_typecheck_pointer_arith_void_type) 6182 << lex->getSourceRange() << rex->getSourceRange(); 6183 return QualType(); 6184 } 6185 6186 ComplainAboutVoid = true; 6187 } else if (rpointee->isFunctionType()) { 6188 if (getLangOptions().CPlusPlus) { 6189 Diag(Loc, diag::err_typecheck_pointer_arith_function_type) 6190 << rex->getType() << rex->getSourceRange(); 6191 return QualType(); 6192 } 6193 6194 // GNU extension: arithmetic on pointer to function 6195 if (!ComplainAboutFunc) 6196 ComplainAboutFunc = rex; 6197 } else if (!rpointee->isDependentType() && 6198 RequireCompleteType(Loc, rpointee, 6199 PDiag(diag::err_typecheck_sub_ptr_object) 6200 << rex->getSourceRange() 6201 << rex->getType())) 6202 return QualType(); 6203 6204 if (getLangOptions().CPlusPlus) { 6205 // Pointee types must be the same: C++ [expr.add] 6206 if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { 6207 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 6208 << lex->getType() << rex->getType() 6209 << lex->getSourceRange() << rex->getSourceRange(); 6210 return QualType(); 6211 } 6212 } else { 6213 // Pointee types must be compatible C99 6.5.6p3 6214 if (!Context.typesAreCompatible( 6215 Context.getCanonicalType(lpointee).getUnqualifiedType(), 6216 Context.getCanonicalType(rpointee).getUnqualifiedType())) { 6217 Diag(Loc, diag::err_typecheck_sub_ptr_compatible) 6218 << lex->getType() << rex->getType() 6219 << lex->getSourceRange() << rex->getSourceRange(); 6220 return QualType(); 6221 } 6222 } 6223 6224 if (ComplainAboutVoid) 6225 Diag(Loc, diag::ext_gnu_void_ptr) 6226 << lex->getSourceRange() << rex->getSourceRange(); 6227 if (ComplainAboutFunc) 6228 Diag(Loc, diag::ext_gnu_ptr_func_arith) 6229 << ComplainAboutFunc->getType() 6230 << ComplainAboutFunc->getSourceRange(); 6231 6232 if (CompLHSTy) *CompLHSTy = lex->getType(); 6233 return Context.getPointerDiffType(); 6234 } 6235 } 6236 6237 return InvalidOperands(Loc, lex, rex); 6238} 6239 6240static bool isScopedEnumerationType(QualType T) { 6241 if (const EnumType *ET = dyn_cast<EnumType>(T)) 6242 return ET->getDecl()->isScoped(); 6243 return false; 6244} 6245 6246// C99 6.5.7 6247QualType Sema::CheckShiftOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 6248 bool isCompAssign) { 6249 // C99 6.5.7p2: Each of the operands shall have integer type. 6250 if (!lex->getType()->hasIntegerRepresentation() || 6251 !rex->getType()->hasIntegerRepresentation()) 6252 return InvalidOperands(Loc, lex, rex); 6253 6254 // C++0x: Don't allow scoped enums. FIXME: Use something better than 6255 // hasIntegerRepresentation() above instead of this. 6256 if (isScopedEnumerationType(lex->getType()) || 6257 isScopedEnumerationType(rex->getType())) { 6258 return InvalidOperands(Loc, lex, rex); 6259 } 6260 6261 // Vector shifts promote their scalar inputs to vector type. 6262 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 6263 return CheckVectorOperands(Loc, lex, rex); 6264 6265 // Shifts don't perform usual arithmetic conversions, they just do integer 6266 // promotions on each operand. C99 6.5.7p3 6267 6268 // For the LHS, do usual unary conversions, but then reset them away 6269 // if this is a compound assignment. 6270 Expr *old_lex = lex; 6271 UsualUnaryConversions(lex); 6272 QualType LHSTy = lex->getType(); 6273 if (isCompAssign) lex = old_lex; 6274 6275 // The RHS is simpler. 6276 UsualUnaryConversions(rex); 6277 6278 // Sanity-check shift operands 6279 llvm::APSInt Right; 6280 // Check right/shifter operand 6281 if (!rex->isValueDependent() && 6282 rex->isIntegerConstantExpr(Right, Context)) { 6283 if (Right.isNegative()) 6284 Diag(Loc, diag::warn_shift_negative) << rex->getSourceRange(); 6285 else { 6286 llvm::APInt LeftBits(Right.getBitWidth(), 6287 Context.getTypeSize(lex->getType())); 6288 if (Right.uge(LeftBits)) 6289 Diag(Loc, diag::warn_shift_gt_typewidth) << rex->getSourceRange(); 6290 } 6291 } 6292 6293 // "The type of the result is that of the promoted left operand." 6294 return LHSTy; 6295} 6296 6297static bool IsWithinTemplateSpecialization(Decl *D) { 6298 if (DeclContext *DC = D->getDeclContext()) { 6299 if (isa<ClassTemplateSpecializationDecl>(DC)) 6300 return true; 6301 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) 6302 return FD->isFunctionTemplateSpecialization(); 6303 } 6304 return false; 6305} 6306 6307// C99 6.5.8, C++ [expr.rel] 6308QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc, 6309 unsigned OpaqueOpc, bool isRelational) { 6310 BinaryOperatorKind Opc = (BinaryOperatorKind) OpaqueOpc; 6311 6312 // Handle vector comparisons separately. 6313 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) 6314 return CheckVectorCompareOperands(lex, rex, Loc, isRelational); 6315 6316 QualType lType = lex->getType(); 6317 QualType rType = rex->getType(); 6318 6319 if (!lType->hasFloatingRepresentation() && 6320 !(lType->isBlockPointerType() && isRelational) && 6321 !lex->getLocStart().isMacroID() && 6322 !rex->getLocStart().isMacroID()) { 6323 // For non-floating point types, check for self-comparisons of the form 6324 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 6325 // often indicate logic errors in the program. 6326 // 6327 // NOTE: Don't warn about comparison expressions resulting from macro 6328 // expansion. Also don't warn about comparisons which are only self 6329 // comparisons within a template specialization. The warnings should catch 6330 // obvious cases in the definition of the template anyways. The idea is to 6331 // warn when the typed comparison operator will always evaluate to the same 6332 // result. 6333 Expr *LHSStripped = lex->IgnoreParenImpCasts(); 6334 Expr *RHSStripped = rex->IgnoreParenImpCasts(); 6335 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { 6336 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { 6337 if (DRL->getDecl() == DRR->getDecl() && 6338 !IsWithinTemplateSpecialization(DRL->getDecl())) { 6339 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 6340 << 0 // self- 6341 << (Opc == BO_EQ 6342 || Opc == BO_LE 6343 || Opc == BO_GE)); 6344 } else if (lType->isArrayType() && rType->isArrayType() && 6345 !DRL->getDecl()->getType()->isReferenceType() && 6346 !DRR->getDecl()->getType()->isReferenceType()) { 6347 // what is it always going to eval to? 6348 char always_evals_to; 6349 switch(Opc) { 6350 case BO_EQ: // e.g. array1 == array2 6351 always_evals_to = 0; // false 6352 break; 6353 case BO_NE: // e.g. array1 != array2 6354 always_evals_to = 1; // true 6355 break; 6356 default: 6357 // best we can say is 'a constant' 6358 always_evals_to = 2; // e.g. array1 <= array2 6359 break; 6360 } 6361 DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always) 6362 << 1 // array 6363 << always_evals_to); 6364 } 6365 } 6366 } 6367 6368 if (isa<CastExpr>(LHSStripped)) 6369 LHSStripped = LHSStripped->IgnoreParenCasts(); 6370 if (isa<CastExpr>(RHSStripped)) 6371 RHSStripped = RHSStripped->IgnoreParenCasts(); 6372 6373 // Warn about comparisons against a string constant (unless the other 6374 // operand is null), the user probably wants strcmp. 6375 Expr *literalString = 0; 6376 Expr *literalStringStripped = 0; 6377 if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && 6378 !RHSStripped->isNullPointerConstant(Context, 6379 Expr::NPC_ValueDependentIsNull)) { 6380 literalString = lex; 6381 literalStringStripped = LHSStripped; 6382 } else if ((isa<StringLiteral>(RHSStripped) || 6383 isa<ObjCEncodeExpr>(RHSStripped)) && 6384 !LHSStripped->isNullPointerConstant(Context, 6385 Expr::NPC_ValueDependentIsNull)) { 6386 literalString = rex; 6387 literalStringStripped = RHSStripped; 6388 } 6389 6390 if (literalString) { 6391 std::string resultComparison; 6392 switch (Opc) { 6393 case BO_LT: resultComparison = ") < 0"; break; 6394 case BO_GT: resultComparison = ") > 0"; break; 6395 case BO_LE: resultComparison = ") <= 0"; break; 6396 case BO_GE: resultComparison = ") >= 0"; break; 6397 case BO_EQ: resultComparison = ") == 0"; break; 6398 case BO_NE: resultComparison = ") != 0"; break; 6399 default: assert(false && "Invalid comparison operator"); 6400 } 6401 6402 DiagRuntimeBehavior(Loc, 6403 PDiag(diag::warn_stringcompare) 6404 << isa<ObjCEncodeExpr>(literalStringStripped) 6405 << literalString->getSourceRange()); 6406 } 6407 } 6408 6409 // C99 6.5.8p3 / C99 6.5.9p4 6410 if (lex->getType()->isArithmeticType() && rex->getType()->isArithmeticType()) 6411 UsualArithmeticConversions(lex, rex); 6412 else { 6413 UsualUnaryConversions(lex); 6414 UsualUnaryConversions(rex); 6415 } 6416 6417 lType = lex->getType(); 6418 rType = rex->getType(); 6419 6420 // The result of comparisons is 'bool' in C++, 'int' in C. 6421 QualType ResultTy = getLangOptions().CPlusPlus ? Context.BoolTy:Context.IntTy; 6422 6423 if (isRelational) { 6424 if (lType->isRealType() && rType->isRealType()) 6425 return ResultTy; 6426 } else { 6427 // Check for comparisons of floating point operands using != and ==. 6428 if (lType->hasFloatingRepresentation()) 6429 CheckFloatComparison(Loc,lex,rex); 6430 6431 if (lType->isArithmeticType() && rType->isArithmeticType()) 6432 return ResultTy; 6433 } 6434 6435 bool LHSIsNull = lex->isNullPointerConstant(Context, 6436 Expr::NPC_ValueDependentIsNull); 6437 bool RHSIsNull = rex->isNullPointerConstant(Context, 6438 Expr::NPC_ValueDependentIsNull); 6439 6440 // All of the following pointer-related warnings are GCC extensions, except 6441 // when handling null pointer constants. 6442 if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 6443 QualType LCanPointeeTy = 6444 Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); 6445 QualType RCanPointeeTy = 6446 Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); 6447 6448 if (getLangOptions().CPlusPlus) { 6449 if (LCanPointeeTy == RCanPointeeTy) 6450 return ResultTy; 6451 if (!isRelational && 6452 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 6453 // Valid unless comparison between non-null pointer and function pointer 6454 // This is a gcc extension compatibility comparison. 6455 // In a SFINAE context, we treat this as a hard error to maintain 6456 // conformance with the C++ standard. 6457 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 6458 && !LHSIsNull && !RHSIsNull) { 6459 Diag(Loc, 6460 isSFINAEContext()? 6461 diag::err_typecheck_comparison_of_fptr_to_void 6462 : diag::ext_typecheck_comparison_of_fptr_to_void) 6463 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6464 6465 if (isSFINAEContext()) 6466 return QualType(); 6467 6468 ImpCastExprToType(rex, lType, CK_BitCast); 6469 return ResultTy; 6470 } 6471 } 6472 6473 // C++ [expr.rel]p2: 6474 // [...] Pointer conversions (4.10) and qualification 6475 // conversions (4.4) are performed on pointer operands (or on 6476 // a pointer operand and a null pointer constant) to bring 6477 // them to their composite pointer type. [...] 6478 // 6479 // C++ [expr.eq]p1 uses the same notion for (in)equality 6480 // comparisons of pointers. 6481 bool NonStandardCompositeType = false; 6482 QualType T = FindCompositePointerType(Loc, lex, rex, 6483 isSFINAEContext()? 0 : &NonStandardCompositeType); 6484 if (T.isNull()) { 6485 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 6486 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6487 return QualType(); 6488 } else if (NonStandardCompositeType) { 6489 Diag(Loc, 6490 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 6491 << lType << rType << T 6492 << lex->getSourceRange() << rex->getSourceRange(); 6493 } 6494 6495 ImpCastExprToType(lex, T, CK_BitCast); 6496 ImpCastExprToType(rex, T, CK_BitCast); 6497 return ResultTy; 6498 } 6499 // C99 6.5.9p2 and C99 6.5.8p2 6500 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), 6501 RCanPointeeTy.getUnqualifiedType())) { 6502 // Valid unless a relational comparison of function pointers 6503 if (isRelational && LCanPointeeTy->isFunctionType()) { 6504 Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) 6505 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6506 } 6507 } else if (!isRelational && 6508 (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { 6509 // Valid unless comparison between non-null pointer and function pointer 6510 if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) 6511 && !LHSIsNull && !RHSIsNull) { 6512 Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) 6513 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6514 } 6515 } else { 6516 // Invalid 6517 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 6518 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6519 } 6520 if (LCanPointeeTy != RCanPointeeTy) 6521 ImpCastExprToType(rex, lType, CK_BitCast); 6522 return ResultTy; 6523 } 6524 6525 if (getLangOptions().CPlusPlus) { 6526 // Comparison of nullptr_t with itself. 6527 if (lType->isNullPtrType() && rType->isNullPtrType()) 6528 return ResultTy; 6529 6530 // Comparison of pointers with null pointer constants and equality 6531 // comparisons of member pointers to null pointer constants. 6532 if (RHSIsNull && 6533 ((lType->isPointerType() || lType->isNullPtrType()) || 6534 (!isRelational && lType->isMemberPointerType()))) { 6535 ImpCastExprToType(rex, lType, 6536 lType->isMemberPointerType() 6537 ? CK_NullToMemberPointer 6538 : CK_NullToPointer); 6539 return ResultTy; 6540 } 6541 if (LHSIsNull && 6542 ((rType->isPointerType() || rType->isNullPtrType()) || 6543 (!isRelational && rType->isMemberPointerType()))) { 6544 ImpCastExprToType(lex, rType, 6545 rType->isMemberPointerType() 6546 ? CK_NullToMemberPointer 6547 : CK_NullToPointer); 6548 return ResultTy; 6549 } 6550 6551 // Comparison of member pointers. 6552 if (!isRelational && 6553 lType->isMemberPointerType() && rType->isMemberPointerType()) { 6554 // C++ [expr.eq]p2: 6555 // In addition, pointers to members can be compared, or a pointer to 6556 // member and a null pointer constant. Pointer to member conversions 6557 // (4.11) and qualification conversions (4.4) are performed to bring 6558 // them to a common type. If one operand is a null pointer constant, 6559 // the common type is the type of the other operand. Otherwise, the 6560 // common type is a pointer to member type similar (4.4) to the type 6561 // of one of the operands, with a cv-qualification signature (4.4) 6562 // that is the union of the cv-qualification signatures of the operand 6563 // types. 6564 bool NonStandardCompositeType = false; 6565 QualType T = FindCompositePointerType(Loc, lex, rex, 6566 isSFINAEContext()? 0 : &NonStandardCompositeType); 6567 if (T.isNull()) { 6568 Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) 6569 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6570 return QualType(); 6571 } else if (NonStandardCompositeType) { 6572 Diag(Loc, 6573 diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) 6574 << lType << rType << T 6575 << lex->getSourceRange() << rex->getSourceRange(); 6576 } 6577 6578 ImpCastExprToType(lex, T, CK_BitCast); 6579 ImpCastExprToType(rex, T, CK_BitCast); 6580 return ResultTy; 6581 } 6582 } 6583 6584 // Handle block pointer types. 6585 if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { 6586 QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); 6587 QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); 6588 6589 if (!LHSIsNull && !RHSIsNull && 6590 !Context.typesAreCompatible(lpointee, rpointee)) { 6591 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 6592 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6593 } 6594 ImpCastExprToType(rex, lType, CK_BitCast); 6595 return ResultTy; 6596 } 6597 // Allow block pointers to be compared with null pointer constants. 6598 if (!isRelational 6599 && ((lType->isBlockPointerType() && rType->isPointerType()) 6600 || (lType->isPointerType() && rType->isBlockPointerType()))) { 6601 if (!LHSIsNull && !RHSIsNull) { 6602 if (!((rType->isPointerType() && rType->getAs<PointerType>() 6603 ->getPointeeType()->isVoidType()) 6604 || (lType->isPointerType() && lType->getAs<PointerType>() 6605 ->getPointeeType()->isVoidType()))) 6606 Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) 6607 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6608 } 6609 ImpCastExprToType(rex, lType, CK_BitCast); 6610 return ResultTy; 6611 } 6612 6613 if ((lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType())) { 6614 if (lType->isPointerType() || rType->isPointerType()) { 6615 const PointerType *LPT = lType->getAs<PointerType>(); 6616 const PointerType *RPT = rType->getAs<PointerType>(); 6617 bool LPtrToVoid = LPT ? 6618 Context.getCanonicalType(LPT->getPointeeType())->isVoidType() : false; 6619 bool RPtrToVoid = RPT ? 6620 Context.getCanonicalType(RPT->getPointeeType())->isVoidType() : false; 6621 6622 if (!LPtrToVoid && !RPtrToVoid && 6623 !Context.typesAreCompatible(lType, rType)) { 6624 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 6625 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6626 } 6627 ImpCastExprToType(rex, lType, CK_BitCast); 6628 return ResultTy; 6629 } 6630 if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { 6631 if (!Context.areComparableObjCPointerTypes(lType, rType)) 6632 Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) 6633 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6634 ImpCastExprToType(rex, lType, CK_BitCast); 6635 return ResultTy; 6636 } 6637 } 6638 if ((lType->isAnyPointerType() && rType->isIntegerType()) || 6639 (lType->isIntegerType() && rType->isAnyPointerType())) { 6640 unsigned DiagID = 0; 6641 bool isError = false; 6642 if ((LHSIsNull && lType->isIntegerType()) || 6643 (RHSIsNull && rType->isIntegerType())) { 6644 if (isRelational && !getLangOptions().CPlusPlus) 6645 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; 6646 } else if (isRelational && !getLangOptions().CPlusPlus) 6647 DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; 6648 else if (getLangOptions().CPlusPlus) { 6649 DiagID = diag::err_typecheck_comparison_of_pointer_integer; 6650 isError = true; 6651 } else 6652 DiagID = diag::ext_typecheck_comparison_of_pointer_integer; 6653 6654 if (DiagID) { 6655 Diag(Loc, DiagID) 6656 << lType << rType << lex->getSourceRange() << rex->getSourceRange(); 6657 if (isError) 6658 return QualType(); 6659 } 6660 6661 if (lType->isIntegerType()) 6662 ImpCastExprToType(lex, rType, 6663 LHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); 6664 else 6665 ImpCastExprToType(rex, lType, 6666 RHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); 6667 return ResultTy; 6668 } 6669 6670 // Handle block pointers. 6671 if (!isRelational && RHSIsNull 6672 && lType->isBlockPointerType() && rType->isIntegerType()) { 6673 ImpCastExprToType(rex, lType, CK_NullToPointer); 6674 return ResultTy; 6675 } 6676 if (!isRelational && LHSIsNull 6677 && lType->isIntegerType() && rType->isBlockPointerType()) { 6678 ImpCastExprToType(lex, rType, CK_NullToPointer); 6679 return ResultTy; 6680 } 6681 return InvalidOperands(Loc, lex, rex); 6682} 6683 6684/// CheckVectorCompareOperands - vector comparisons are a clang extension that 6685/// operates on extended vector types. Instead of producing an IntTy result, 6686/// like a scalar comparison, a vector comparison produces a vector of integer 6687/// types. 6688QualType Sema::CheckVectorCompareOperands(Expr *&lex, Expr *&rex, 6689 SourceLocation Loc, 6690 bool isRelational) { 6691 // Check to make sure we're operating on vectors of the same type and width, 6692 // Allowing one side to be a scalar of element type. 6693 QualType vType = CheckVectorOperands(Loc, lex, rex); 6694 if (vType.isNull()) 6695 return vType; 6696 6697 // If AltiVec, the comparison results in a numeric type, i.e. 6698 // bool for C++, int for C 6699 if (getLangOptions().AltiVec) 6700 return (getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy); 6701 6702 QualType lType = lex->getType(); 6703 QualType rType = rex->getType(); 6704 6705 // For non-floating point types, check for self-comparisons of the form 6706 // x == x, x != x, x < x, etc. These always evaluate to a constant, and 6707 // often indicate logic errors in the program. 6708 if (!lType->hasFloatingRepresentation()) { 6709 if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens())) 6710 if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens())) 6711 if (DRL->getDecl() == DRR->getDecl()) 6712 DiagRuntimeBehavior(Loc, 6713 PDiag(diag::warn_comparison_always) 6714 << 0 // self- 6715 << 2 // "a constant" 6716 ); 6717 } 6718 6719 // Check for comparisons of floating point operands using != and ==. 6720 if (!isRelational && lType->hasFloatingRepresentation()) { 6721 assert (rType->hasFloatingRepresentation()); 6722 CheckFloatComparison(Loc,lex,rex); 6723 } 6724 6725 // Return the type for the comparison, which is the same as vector type for 6726 // integer vectors, or an integer type of identical size and number of 6727 // elements for floating point vectors. 6728 if (lType->hasIntegerRepresentation()) 6729 return lType; 6730 6731 const VectorType *VTy = lType->getAs<VectorType>(); 6732 unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); 6733 if (TypeSize == Context.getTypeSize(Context.IntTy)) 6734 return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); 6735 if (TypeSize == Context.getTypeSize(Context.LongTy)) 6736 return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); 6737 6738 assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && 6739 "Unhandled vector element size in vector compare"); 6740 return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); 6741} 6742 6743inline QualType Sema::CheckBitwiseOperands( 6744 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isCompAssign) { 6745 if (lex->getType()->isVectorType() || rex->getType()->isVectorType()) { 6746 if (lex->getType()->hasIntegerRepresentation() && 6747 rex->getType()->hasIntegerRepresentation()) 6748 return CheckVectorOperands(Loc, lex, rex); 6749 6750 return InvalidOperands(Loc, lex, rex); 6751 } 6752 6753 QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); 6754 6755 if (lex->getType()->isIntegralOrUnscopedEnumerationType() && 6756 rex->getType()->isIntegralOrUnscopedEnumerationType()) 6757 return compType; 6758 return InvalidOperands(Loc, lex, rex); 6759} 6760 6761inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] 6762 Expr *&lex, Expr *&rex, SourceLocation Loc, unsigned Opc) { 6763 6764 // Diagnose cases where the user write a logical and/or but probably meant a 6765 // bitwise one. We do this when the LHS is a non-bool integer and the RHS 6766 // is a constant. 6767 if (lex->getType()->isIntegerType() && !lex->getType()->isBooleanType() && 6768 rex->getType()->isIntegerType() && !rex->isValueDependent() && 6769 // Don't warn in macros. 6770 !Loc.isMacroID()) { 6771 // If the RHS can be constant folded, and if it constant folds to something 6772 // that isn't 0 or 1 (which indicate a potential logical operation that 6773 // happened to fold to true/false) then warn. 6774 Expr::EvalResult Result; 6775 if (rex->Evaluate(Result, Context) && !Result.HasSideEffects && 6776 Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { 6777 Diag(Loc, diag::warn_logical_instead_of_bitwise) 6778 << rex->getSourceRange() 6779 << (Opc == BO_LAnd ? "&&" : "||") 6780 << (Opc == BO_LAnd ? "&" : "|"); 6781 } 6782 } 6783 6784 if (!Context.getLangOptions().CPlusPlus) { 6785 UsualUnaryConversions(lex); 6786 UsualUnaryConversions(rex); 6787 6788 if (!lex->getType()->isScalarType() || !rex->getType()->isScalarType()) 6789 return InvalidOperands(Loc, lex, rex); 6790 6791 return Context.IntTy; 6792 } 6793 6794 // The following is safe because we only use this method for 6795 // non-overloadable operands. 6796 6797 // C++ [expr.log.and]p1 6798 // C++ [expr.log.or]p1 6799 // The operands are both contextually converted to type bool. 6800 if (PerformContextuallyConvertToBool(lex) || 6801 PerformContextuallyConvertToBool(rex)) 6802 return InvalidOperands(Loc, lex, rex); 6803 6804 // C++ [expr.log.and]p2 6805 // C++ [expr.log.or]p2 6806 // The result is a bool. 6807 return Context.BoolTy; 6808} 6809 6810/// IsReadonlyProperty - Verify that otherwise a valid l-value expression 6811/// is a read-only property; return true if so. A readonly property expression 6812/// depends on various declarations and thus must be treated specially. 6813/// 6814static bool IsReadonlyProperty(Expr *E, Sema &S) { 6815 if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { 6816 const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); 6817 if (PropExpr->isImplicitProperty()) return false; 6818 6819 ObjCPropertyDecl *PDecl = PropExpr->getExplicitProperty(); 6820 QualType BaseType = PropExpr->isSuperReceiver() ? 6821 PropExpr->getSuperReceiverType() : 6822 PropExpr->getBase()->getType(); 6823 6824 if (const ObjCObjectPointerType *OPT = 6825 BaseType->getAsObjCInterfacePointerType()) 6826 if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) 6827 if (S.isPropertyReadonly(PDecl, IFace)) 6828 return true; 6829 } 6830 return false; 6831} 6832 6833/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, 6834/// emit an error and return true. If so, return false. 6835static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { 6836 SourceLocation OrigLoc = Loc; 6837 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, 6838 &Loc); 6839 if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) 6840 IsLV = Expr::MLV_ReadonlyProperty; 6841 if (IsLV == Expr::MLV_Valid) 6842 return false; 6843 6844 unsigned Diag = 0; 6845 bool NeedType = false; 6846 switch (IsLV) { // C99 6.5.16p2 6847 case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; 6848 case Expr::MLV_ArrayType: 6849 Diag = diag::err_typecheck_array_not_modifiable_lvalue; 6850 NeedType = true; 6851 break; 6852 case Expr::MLV_NotObjectType: 6853 Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; 6854 NeedType = true; 6855 break; 6856 case Expr::MLV_LValueCast: 6857 Diag = diag::err_typecheck_lvalue_casts_not_supported; 6858 break; 6859 case Expr::MLV_Valid: 6860 llvm_unreachable("did not take early return for MLV_Valid"); 6861 case Expr::MLV_InvalidExpression: 6862 case Expr::MLV_MemberFunction: 6863 case Expr::MLV_ClassTemporary: 6864 Diag = diag::err_typecheck_expression_not_modifiable_lvalue; 6865 break; 6866 case Expr::MLV_IncompleteType: 6867 case Expr::MLV_IncompleteVoidType: 6868 return S.RequireCompleteType(Loc, E->getType(), 6869 S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) 6870 << E->getSourceRange()); 6871 case Expr::MLV_DuplicateVectorComponents: 6872 Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; 6873 break; 6874 case Expr::MLV_NotBlockQualified: 6875 Diag = diag::err_block_decl_ref_not_modifiable_lvalue; 6876 break; 6877 case Expr::MLV_ReadonlyProperty: 6878 Diag = diag::error_readonly_property_assignment; 6879 break; 6880 case Expr::MLV_NoSetterProperty: 6881 Diag = diag::error_nosetter_property_assignment; 6882 break; 6883 case Expr::MLV_SubObjCPropertySetting: 6884 Diag = diag::error_no_subobject_property_setting; 6885 break; 6886 } 6887 6888 SourceRange Assign; 6889 if (Loc != OrigLoc) 6890 Assign = SourceRange(OrigLoc, OrigLoc); 6891 if (NeedType) 6892 S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; 6893 else 6894 S.Diag(Loc, Diag) << E->getSourceRange() << Assign; 6895 return true; 6896} 6897 6898 6899 6900// C99 6.5.16.1 6901QualType Sema::CheckAssignmentOperands(Expr *LHS, Expr *&RHS, 6902 SourceLocation Loc, 6903 QualType CompoundType) { 6904 // Verify that LHS is a modifiable lvalue, and emit error if not. 6905 if (CheckForModifiableLvalue(LHS, Loc, *this)) 6906 return QualType(); 6907 6908 QualType LHSType = LHS->getType(); 6909 QualType RHSType = CompoundType.isNull() ? RHS->getType() : CompoundType; 6910 AssignConvertType ConvTy; 6911 if (CompoundType.isNull()) { 6912 QualType LHSTy(LHSType); 6913 // Simple assignment "x = y". 6914 if (LHS->getObjectKind() == OK_ObjCProperty) 6915 ConvertPropertyForLValue(LHS, RHS, LHSTy); 6916 ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); 6917 // Special case of NSObject attributes on c-style pointer types. 6918 if (ConvTy == IncompatiblePointer && 6919 ((Context.isObjCNSObjectType(LHSType) && 6920 RHSType->isObjCObjectPointerType()) || 6921 (Context.isObjCNSObjectType(RHSType) && 6922 LHSType->isObjCObjectPointerType()))) 6923 ConvTy = Compatible; 6924 6925 if (ConvTy == Compatible && 6926 getLangOptions().ObjCNonFragileABI && 6927 LHSType->isObjCObjectType()) 6928 Diag(Loc, diag::err_assignment_requires_nonfragile_object) 6929 << LHSType; 6930 6931 // If the RHS is a unary plus or minus, check to see if they = and + are 6932 // right next to each other. If so, the user may have typo'd "x =+ 4" 6933 // instead of "x += 4". 6934 Expr *RHSCheck = RHS; 6935 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) 6936 RHSCheck = ICE->getSubExpr(); 6937 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { 6938 if ((UO->getOpcode() == UO_Plus || 6939 UO->getOpcode() == UO_Minus) && 6940 Loc.isFileID() && UO->getOperatorLoc().isFileID() && 6941 // Only if the two operators are exactly adjacent. 6942 Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && 6943 // And there is a space or other character before the subexpr of the 6944 // unary +/-. We don't want to warn on "x=-1". 6945 Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && 6946 UO->getSubExpr()->getLocStart().isFileID()) { 6947 Diag(Loc, diag::warn_not_compound_assign) 6948 << (UO->getOpcode() == UO_Plus ? "+" : "-") 6949 << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); 6950 } 6951 } 6952 } else { 6953 // Compound assignment "x += y" 6954 ConvTy = CheckAssignmentConstraints(LHSType, RHSType); 6955 } 6956 6957 if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, 6958 RHS, AA_Assigning)) 6959 return QualType(); 6960 6961 6962 // Check to see if the destination operand is a dereferenced null pointer. If 6963 // so, and if not volatile-qualified, this is undefined behavior that the 6964 // optimizer will delete, so warn about it. People sometimes try to use this 6965 // to get a deterministic trap and are surprised by clang's behavior. This 6966 // only handles the pattern "*null = whatever", which is a very syntactic 6967 // check. 6968 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(LHS->IgnoreParenCasts())) 6969 if (UO->getOpcode() == UO_Deref && 6970 UO->getSubExpr()->IgnoreParenCasts()-> 6971 isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) && 6972 !UO->getType().isVolatileQualified()) { 6973 Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null) 6974 << UO->getSubExpr()->getSourceRange(); 6975 Diag(UO->getOperatorLoc(), diag::note_indirection_through_null); 6976 } 6977 6978 // C99 6.5.16p3: The type of an assignment expression is the type of the 6979 // left operand unless the left operand has qualified type, in which case 6980 // it is the unqualified version of the type of the left operand. 6981 // C99 6.5.16.1p2: In simple assignment, the value of the right operand 6982 // is converted to the type of the assignment expression (above). 6983 // C++ 5.17p1: the type of the assignment expression is that of its left 6984 // operand. 6985 return (getLangOptions().CPlusPlus 6986 ? LHSType : LHSType.getUnqualifiedType()); 6987} 6988 6989// C99 6.5.17 6990static QualType CheckCommaOperands(Sema &S, Expr *&LHS, Expr *&RHS, 6991 SourceLocation Loc) { 6992 S.DiagnoseUnusedExprResult(LHS); 6993 6994 ExprResult LHSResult = S.CheckPlaceholderExpr(LHS, Loc); 6995 if (LHSResult.isInvalid()) 6996 return QualType(); 6997 6998 ExprResult RHSResult = S.CheckPlaceholderExpr(RHS, Loc); 6999 if (RHSResult.isInvalid()) 7000 return QualType(); 7001 RHS = RHSResult.take(); 7002 7003 // C's comma performs lvalue conversion (C99 6.3.2.1) on both its 7004 // operands, but not unary promotions. 7005 // C++'s comma does not do any conversions at all (C++ [expr.comma]p1). 7006 7007 // So we treat the LHS as a ignored value, and in C++ we allow the 7008 // containing site to determine what should be done with the RHS. 7009 S.IgnoredValueConversions(LHS); 7010 7011 if (!S.getLangOptions().CPlusPlus) { 7012 S.DefaultFunctionArrayLvalueConversion(RHS); 7013 if (!RHS->getType()->isVoidType()) 7014 S.RequireCompleteType(Loc, RHS->getType(), diag::err_incomplete_type); 7015 } 7016 7017 return RHS->getType(); 7018} 7019 7020/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine 7021/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. 7022static QualType CheckIncrementDecrementOperand(Sema &S, Expr *Op, 7023 ExprValueKind &VK, 7024 SourceLocation OpLoc, 7025 bool isInc, bool isPrefix) { 7026 if (Op->isTypeDependent()) 7027 return S.Context.DependentTy; 7028 7029 QualType ResType = Op->getType(); 7030 assert(!ResType.isNull() && "no type for increment/decrement expression"); 7031 7032 if (S.getLangOptions().CPlusPlus && ResType->isBooleanType()) { 7033 // Decrement of bool is not allowed. 7034 if (!isInc) { 7035 S.Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); 7036 return QualType(); 7037 } 7038 // Increment of bool sets it to true, but is deprecated. 7039 S.Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); 7040 } else if (ResType->isRealType()) { 7041 // OK! 7042 } else if (ResType->isAnyPointerType()) { 7043 QualType PointeeTy = ResType->getPointeeType(); 7044 7045 // C99 6.5.2.4p2, 6.5.6p2 7046 if (PointeeTy->isVoidType()) { 7047 if (S.getLangOptions().CPlusPlus) { 7048 S.Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) 7049 << Op->getSourceRange(); 7050 return QualType(); 7051 } 7052 7053 // Pointer to void is a GNU extension in C. 7054 S.Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); 7055 } else if (PointeeTy->isFunctionType()) { 7056 if (S.getLangOptions().CPlusPlus) { 7057 S.Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) 7058 << Op->getType() << Op->getSourceRange(); 7059 return QualType(); 7060 } 7061 7062 S.Diag(OpLoc, diag::ext_gnu_ptr_func_arith) 7063 << ResType << Op->getSourceRange(); 7064 } else if (S.RequireCompleteType(OpLoc, PointeeTy, 7065 S.PDiag(diag::err_typecheck_arithmetic_incomplete_type) 7066 << Op->getSourceRange() 7067 << ResType)) 7068 return QualType(); 7069 // Diagnose bad cases where we step over interface counts. 7070 else if (PointeeTy->isObjCObjectType() && S.LangOpts.ObjCNonFragileABI) { 7071 S.Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) 7072 << PointeeTy << Op->getSourceRange(); 7073 return QualType(); 7074 } 7075 } else if (ResType->isAnyComplexType()) { 7076 // C99 does not support ++/-- on complex types, we allow as an extension. 7077 S.Diag(OpLoc, diag::ext_integer_increment_complex) 7078 << ResType << Op->getSourceRange(); 7079 } else if (ResType->isPlaceholderType()) { 7080 ExprResult PR = S.CheckPlaceholderExpr(Op, OpLoc); 7081 if (PR.isInvalid()) return QualType(); 7082 return CheckIncrementDecrementOperand(S, PR.take(), VK, OpLoc, 7083 isInc, isPrefix); 7084 } else { 7085 S.Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) 7086 << ResType << int(isInc) << Op->getSourceRange(); 7087 return QualType(); 7088 } 7089 // At this point, we know we have a real, complex or pointer type. 7090 // Now make sure the operand is a modifiable lvalue. 7091 if (CheckForModifiableLvalue(Op, OpLoc, S)) 7092 return QualType(); 7093 // In C++, a prefix increment is the same type as the operand. Otherwise 7094 // (in C or with postfix), the increment is the unqualified type of the 7095 // operand. 7096 if (isPrefix && S.getLangOptions().CPlusPlus) { 7097 VK = VK_LValue; 7098 return ResType; 7099 } else { 7100 VK = VK_RValue; 7101 return ResType.getUnqualifiedType(); 7102 } 7103} 7104 7105void Sema::ConvertPropertyForRValue(Expr *&E) { 7106 assert(E->getValueKind() == VK_LValue && 7107 E->getObjectKind() == OK_ObjCProperty); 7108 const ObjCPropertyRefExpr *PRE = E->getObjCProperty(); 7109 7110 ExprValueKind VK = VK_RValue; 7111 if (PRE->isImplicitProperty()) { 7112 if (const ObjCMethodDecl *GetterMethod = 7113 PRE->getImplicitPropertyGetter()) { 7114 QualType Result = GetterMethod->getResultType(); 7115 VK = Expr::getValueKindForType(Result); 7116 } 7117 else { 7118 Diag(PRE->getLocation(), diag::err_getter_not_found) 7119 << PRE->getBase()->getType(); 7120 } 7121 } 7122 7123 E = ImplicitCastExpr::Create(Context, E->getType(), CK_GetObjCProperty, 7124 E, 0, VK); 7125 7126 ExprResult Result = MaybeBindToTemporary(E); 7127 if (!Result.isInvalid()) 7128 E = Result.take(); 7129} 7130 7131void Sema::ConvertPropertyForLValue(Expr *&LHS, Expr *&RHS, QualType &LHSTy) { 7132 assert(LHS->getValueKind() == VK_LValue && 7133 LHS->getObjectKind() == OK_ObjCProperty); 7134 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 7135 7136 if (PRE->isImplicitProperty()) { 7137 // If using property-dot syntax notation for assignment, and there is a 7138 // setter, RHS expression is being passed to the setter argument. So, 7139 // type conversion (and comparison) is RHS to setter's argument type. 7140 if (const ObjCMethodDecl *SetterMD = PRE->getImplicitPropertySetter()) { 7141 ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); 7142 LHSTy = (*P)->getType(); 7143 7144 // Otherwise, if the getter returns an l-value, just call that. 7145 } else { 7146 QualType Result = PRE->getImplicitPropertyGetter()->getResultType(); 7147 ExprValueKind VK = Expr::getValueKindForType(Result); 7148 if (VK == VK_LValue) { 7149 LHS = ImplicitCastExpr::Create(Context, LHS->getType(), 7150 CK_GetObjCProperty, LHS, 0, VK); 7151 return; 7152 } 7153 } 7154 } 7155 7156 if (getLangOptions().CPlusPlus && LHSTy->isRecordType()) { 7157 InitializedEntity Entity = 7158 InitializedEntity::InitializeParameter(Context, LHSTy); 7159 Expr *Arg = RHS; 7160 ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), 7161 Owned(Arg)); 7162 if (!ArgE.isInvalid()) 7163 RHS = ArgE.takeAs<Expr>(); 7164 } 7165} 7166 7167 7168/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). 7169/// This routine allows us to typecheck complex/recursive expressions 7170/// where the declaration is needed for type checking. We only need to 7171/// handle cases when the expression references a function designator 7172/// or is an lvalue. Here are some examples: 7173/// - &(x) => x 7174/// - &*****f => f for f a function designator. 7175/// - &s.xx => s 7176/// - &s.zz[1].yy -> s, if zz is an array 7177/// - *(x + 1) -> x, if x is an array 7178/// - &"123"[2] -> 0 7179/// - & __real__ x -> x 7180static NamedDecl *getPrimaryDecl(Expr *E) { 7181 switch (E->getStmtClass()) { 7182 case Stmt::DeclRefExprClass: 7183 return cast<DeclRefExpr>(E)->getDecl(); 7184 case Stmt::MemberExprClass: 7185 // If this is an arrow operator, the address is an offset from 7186 // the base's value, so the object the base refers to is 7187 // irrelevant. 7188 if (cast<MemberExpr>(E)->isArrow()) 7189 return 0; 7190 // Otherwise, the expression refers to a part of the base 7191 return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); 7192 case Stmt::ArraySubscriptExprClass: { 7193 // FIXME: This code shouldn't be necessary! We should catch the implicit 7194 // promotion of register arrays earlier. 7195 Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); 7196 if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { 7197 if (ICE->getSubExpr()->getType()->isArrayType()) 7198 return getPrimaryDecl(ICE->getSubExpr()); 7199 } 7200 return 0; 7201 } 7202 case Stmt::UnaryOperatorClass: { 7203 UnaryOperator *UO = cast<UnaryOperator>(E); 7204 7205 switch(UO->getOpcode()) { 7206 case UO_Real: 7207 case UO_Imag: 7208 case UO_Extension: 7209 return getPrimaryDecl(UO->getSubExpr()); 7210 default: 7211 return 0; 7212 } 7213 } 7214 case Stmt::ParenExprClass: 7215 return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); 7216 case Stmt::ImplicitCastExprClass: 7217 // If the result of an implicit cast is an l-value, we care about 7218 // the sub-expression; otherwise, the result here doesn't matter. 7219 return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); 7220 default: 7221 return 0; 7222 } 7223} 7224 7225/// CheckAddressOfOperand - The operand of & must be either a function 7226/// designator or an lvalue designating an object. If it is an lvalue, the 7227/// object cannot be declared with storage class register or be a bit field. 7228/// Note: The usual conversions are *not* applied to the operand of the & 7229/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. 7230/// In C++, the operand might be an overloaded function name, in which case 7231/// we allow the '&' but retain the overloaded-function type. 7232static QualType CheckAddressOfOperand(Sema &S, Expr *OrigOp, 7233 SourceLocation OpLoc) { 7234 if (OrigOp->isTypeDependent()) 7235 return S.Context.DependentTy; 7236 if (OrigOp->getType() == S.Context.OverloadTy) 7237 return S.Context.OverloadTy; 7238 7239 ExprResult PR = S.CheckPlaceholderExpr(OrigOp, OpLoc); 7240 if (PR.isInvalid()) return QualType(); 7241 OrigOp = PR.take(); 7242 7243 // Make sure to ignore parentheses in subsequent checks 7244 Expr *op = OrigOp->IgnoreParens(); 7245 7246 if (S.getLangOptions().C99) { 7247 // Implement C99-only parts of addressof rules. 7248 if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { 7249 if (uOp->getOpcode() == UO_Deref) 7250 // Per C99 6.5.3.2, the address of a deref always returns a valid result 7251 // (assuming the deref expression is valid). 7252 return uOp->getSubExpr()->getType(); 7253 } 7254 // Technically, there should be a check for array subscript 7255 // expressions here, but the result of one is always an lvalue anyway. 7256 } 7257 NamedDecl *dcl = getPrimaryDecl(op); 7258 Expr::LValueClassification lval = op->ClassifyLValue(S.Context); 7259 7260 if (lval == Expr::LV_ClassTemporary) { 7261 bool sfinae = S.isSFINAEContext(); 7262 S.Diag(OpLoc, sfinae ? diag::err_typecheck_addrof_class_temporary 7263 : diag::ext_typecheck_addrof_class_temporary) 7264 << op->getType() << op->getSourceRange(); 7265 if (sfinae) 7266 return QualType(); 7267 } else if (isa<ObjCSelectorExpr>(op)) { 7268 return S.Context.getPointerType(op->getType()); 7269 } else if (lval == Expr::LV_MemberFunction) { 7270 // If it's an instance method, make a member pointer. 7271 // The expression must have exactly the form &A::foo. 7272 7273 // If the underlying expression isn't a decl ref, give up. 7274 if (!isa<DeclRefExpr>(op)) { 7275 S.Diag(OpLoc, diag::err_invalid_form_pointer_member_function) 7276 << OrigOp->getSourceRange(); 7277 return QualType(); 7278 } 7279 DeclRefExpr *DRE = cast<DeclRefExpr>(op); 7280 CXXMethodDecl *MD = cast<CXXMethodDecl>(DRE->getDecl()); 7281 7282 // The id-expression was parenthesized. 7283 if (OrigOp != DRE) { 7284 S.Diag(OpLoc, diag::err_parens_pointer_member_function) 7285 << OrigOp->getSourceRange(); 7286 7287 // The method was named without a qualifier. 7288 } else if (!DRE->getQualifier()) { 7289 S.Diag(OpLoc, diag::err_unqualified_pointer_member_function) 7290 << op->getSourceRange(); 7291 } 7292 7293 return S.Context.getMemberPointerType(op->getType(), 7294 S.Context.getTypeDeclType(MD->getParent()).getTypePtr()); 7295 } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { 7296 // C99 6.5.3.2p1 7297 // The operand must be either an l-value or a function designator 7298 if (!op->getType()->isFunctionType()) { 7299 // FIXME: emit more specific diag... 7300 S.Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) 7301 << op->getSourceRange(); 7302 return QualType(); 7303 } 7304 } else if (op->getObjectKind() == OK_BitField) { // C99 6.5.3.2p1 7305 // The operand cannot be a bit-field 7306 S.Diag(OpLoc, diag::err_typecheck_address_of) 7307 << "bit-field" << op->getSourceRange(); 7308 return QualType(); 7309 } else if (op->getObjectKind() == OK_VectorComponent) { 7310 // The operand cannot be an element of a vector 7311 S.Diag(OpLoc, diag::err_typecheck_address_of) 7312 << "vector element" << op->getSourceRange(); 7313 return QualType(); 7314 } else if (op->getObjectKind() == OK_ObjCProperty) { 7315 // cannot take address of a property expression. 7316 S.Diag(OpLoc, diag::err_typecheck_address_of) 7317 << "property expression" << op->getSourceRange(); 7318 return QualType(); 7319 } else if (dcl) { // C99 6.5.3.2p1 7320 // We have an lvalue with a decl. Make sure the decl is not declared 7321 // with the register storage-class specifier. 7322 if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { 7323 // in C++ it is not error to take address of a register 7324 // variable (c++03 7.1.1P3) 7325 if (vd->getStorageClass() == SC_Register && 7326 !S.getLangOptions().CPlusPlus) { 7327 S.Diag(OpLoc, diag::err_typecheck_address_of) 7328 << "register variable" << op->getSourceRange(); 7329 return QualType(); 7330 } 7331 } else if (isa<FunctionTemplateDecl>(dcl)) { 7332 return S.Context.OverloadTy; 7333 } else if (FieldDecl *FD = dyn_cast<FieldDecl>(dcl)) { 7334 // Okay: we can take the address of a field. 7335 // Could be a pointer to member, though, if there is an explicit 7336 // scope qualifier for the class. 7337 if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { 7338 DeclContext *Ctx = dcl->getDeclContext(); 7339 if (Ctx && Ctx->isRecord()) { 7340 if (FD->getType()->isReferenceType()) { 7341 S.Diag(OpLoc, 7342 diag::err_cannot_form_pointer_to_member_of_reference_type) 7343 << FD->getDeclName() << FD->getType(); 7344 return QualType(); 7345 } 7346 7347 return S.Context.getMemberPointerType(op->getType(), 7348 S.Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); 7349 } 7350 } 7351 } else if (!isa<FunctionDecl>(dcl)) 7352 assert(0 && "Unknown/unexpected decl type"); 7353 } 7354 7355 if (lval == Expr::LV_IncompleteVoidType) { 7356 // Taking the address of a void variable is technically illegal, but we 7357 // allow it in cases which are otherwise valid. 7358 // Example: "extern void x; void* y = &x;". 7359 S.Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); 7360 } 7361 7362 // If the operand has type "type", the result has type "pointer to type". 7363 if (op->getType()->isObjCObjectType()) 7364 return S.Context.getObjCObjectPointerType(op->getType()); 7365 return S.Context.getPointerType(op->getType()); 7366} 7367 7368/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). 7369static QualType CheckIndirectionOperand(Sema &S, Expr *Op, ExprValueKind &VK, 7370 SourceLocation OpLoc) { 7371 if (Op->isTypeDependent()) 7372 return S.Context.DependentTy; 7373 7374 S.UsualUnaryConversions(Op); 7375 QualType OpTy = Op->getType(); 7376 QualType Result; 7377 7378 // Note that per both C89 and C99, indirection is always legal, even if OpTy 7379 // is an incomplete type or void. It would be possible to warn about 7380 // dereferencing a void pointer, but it's completely well-defined, and such a 7381 // warning is unlikely to catch any mistakes. 7382 if (const PointerType *PT = OpTy->getAs<PointerType>()) 7383 Result = PT->getPointeeType(); 7384 else if (const ObjCObjectPointerType *OPT = 7385 OpTy->getAs<ObjCObjectPointerType>()) 7386 Result = OPT->getPointeeType(); 7387 else { 7388 ExprResult PR = S.CheckPlaceholderExpr(Op, OpLoc); 7389 if (PR.isInvalid()) return QualType(); 7390 if (PR.take() != Op) 7391 return CheckIndirectionOperand(S, PR.take(), VK, OpLoc); 7392 } 7393 7394 if (Result.isNull()) { 7395 S.Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) 7396 << OpTy << Op->getSourceRange(); 7397 return QualType(); 7398 } 7399 7400 // Dereferences are usually l-values... 7401 VK = VK_LValue; 7402 7403 // ...except that certain expressions are never l-values in C. 7404 if (!S.getLangOptions().CPlusPlus && 7405 IsCForbiddenLValueType(S.Context, Result)) 7406 VK = VK_RValue; 7407 7408 return Result; 7409} 7410 7411static inline BinaryOperatorKind ConvertTokenKindToBinaryOpcode( 7412 tok::TokenKind Kind) { 7413 BinaryOperatorKind Opc; 7414 switch (Kind) { 7415 default: assert(0 && "Unknown binop!"); 7416 case tok::periodstar: Opc = BO_PtrMemD; break; 7417 case tok::arrowstar: Opc = BO_PtrMemI; break; 7418 case tok::star: Opc = BO_Mul; break; 7419 case tok::slash: Opc = BO_Div; break; 7420 case tok::percent: Opc = BO_Rem; break; 7421 case tok::plus: Opc = BO_Add; break; 7422 case tok::minus: Opc = BO_Sub; break; 7423 case tok::lessless: Opc = BO_Shl; break; 7424 case tok::greatergreater: Opc = BO_Shr; break; 7425 case tok::lessequal: Opc = BO_LE; break; 7426 case tok::less: Opc = BO_LT; break; 7427 case tok::greaterequal: Opc = BO_GE; break; 7428 case tok::greater: Opc = BO_GT; break; 7429 case tok::exclaimequal: Opc = BO_NE; break; 7430 case tok::equalequal: Opc = BO_EQ; break; 7431 case tok::amp: Opc = BO_And; break; 7432 case tok::caret: Opc = BO_Xor; break; 7433 case tok::pipe: Opc = BO_Or; break; 7434 case tok::ampamp: Opc = BO_LAnd; break; 7435 case tok::pipepipe: Opc = BO_LOr; break; 7436 case tok::equal: Opc = BO_Assign; break; 7437 case tok::starequal: Opc = BO_MulAssign; break; 7438 case tok::slashequal: Opc = BO_DivAssign; break; 7439 case tok::percentequal: Opc = BO_RemAssign; break; 7440 case tok::plusequal: Opc = BO_AddAssign; break; 7441 case tok::minusequal: Opc = BO_SubAssign; break; 7442 case tok::lesslessequal: Opc = BO_ShlAssign; break; 7443 case tok::greatergreaterequal: Opc = BO_ShrAssign; break; 7444 case tok::ampequal: Opc = BO_AndAssign; break; 7445 case tok::caretequal: Opc = BO_XorAssign; break; 7446 case tok::pipeequal: Opc = BO_OrAssign; break; 7447 case tok::comma: Opc = BO_Comma; break; 7448 } 7449 return Opc; 7450} 7451 7452static inline UnaryOperatorKind ConvertTokenKindToUnaryOpcode( 7453 tok::TokenKind Kind) { 7454 UnaryOperatorKind Opc; 7455 switch (Kind) { 7456 default: assert(0 && "Unknown unary op!"); 7457 case tok::plusplus: Opc = UO_PreInc; break; 7458 case tok::minusminus: Opc = UO_PreDec; break; 7459 case tok::amp: Opc = UO_AddrOf; break; 7460 case tok::star: Opc = UO_Deref; break; 7461 case tok::plus: Opc = UO_Plus; break; 7462 case tok::minus: Opc = UO_Minus; break; 7463 case tok::tilde: Opc = UO_Not; break; 7464 case tok::exclaim: Opc = UO_LNot; break; 7465 case tok::kw___real: Opc = UO_Real; break; 7466 case tok::kw___imag: Opc = UO_Imag; break; 7467 case tok::kw___extension__: Opc = UO_Extension; break; 7468 } 7469 return Opc; 7470} 7471 7472/// DiagnoseSelfAssignment - Emits a warning if a value is assigned to itself. 7473/// This warning is only emitted for builtin assignment operations. It is also 7474/// suppressed in the event of macro expansions. 7475static void DiagnoseSelfAssignment(Sema &S, Expr *lhs, Expr *rhs, 7476 SourceLocation OpLoc) { 7477 if (!S.ActiveTemplateInstantiations.empty()) 7478 return; 7479 if (OpLoc.isInvalid() || OpLoc.isMacroID()) 7480 return; 7481 lhs = lhs->IgnoreParenImpCasts(); 7482 rhs = rhs->IgnoreParenImpCasts(); 7483 const DeclRefExpr *LeftDeclRef = dyn_cast<DeclRefExpr>(lhs); 7484 const DeclRefExpr *RightDeclRef = dyn_cast<DeclRefExpr>(rhs); 7485 if (!LeftDeclRef || !RightDeclRef || 7486 LeftDeclRef->getLocation().isMacroID() || 7487 RightDeclRef->getLocation().isMacroID()) 7488 return; 7489 const ValueDecl *LeftDecl = 7490 cast<ValueDecl>(LeftDeclRef->getDecl()->getCanonicalDecl()); 7491 const ValueDecl *RightDecl = 7492 cast<ValueDecl>(RightDeclRef->getDecl()->getCanonicalDecl()); 7493 if (LeftDecl != RightDecl) 7494 return; 7495 if (LeftDecl->getType().isVolatileQualified()) 7496 return; 7497 if (const ReferenceType *RefTy = LeftDecl->getType()->getAs<ReferenceType>()) 7498 if (RefTy->getPointeeType().isVolatileQualified()) 7499 return; 7500 7501 S.Diag(OpLoc, diag::warn_self_assignment) 7502 << LeftDeclRef->getType() 7503 << lhs->getSourceRange() << rhs->getSourceRange(); 7504} 7505 7506/// CreateBuiltinBinOp - Creates a new built-in binary operation with 7507/// operator @p Opc at location @c TokLoc. This routine only supports 7508/// built-in operations; ActOnBinOp handles overloaded operators. 7509ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, 7510 BinaryOperatorKind Opc, 7511 Expr *lhs, Expr *rhs) { 7512 QualType ResultTy; // Result type of the binary operator. 7513 // The following two variables are used for compound assignment operators 7514 QualType CompLHSTy; // Type of LHS after promotions for computation 7515 QualType CompResultTy; // Type of computation result 7516 ExprValueKind VK = VK_RValue; 7517 ExprObjectKind OK = OK_Ordinary; 7518 7519 switch (Opc) { 7520 case BO_Assign: 7521 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, QualType()); 7522 if (getLangOptions().CPlusPlus && 7523 lhs->getObjectKind() != OK_ObjCProperty) { 7524 VK = lhs->getValueKind(); 7525 OK = lhs->getObjectKind(); 7526 } 7527 if (!ResultTy.isNull()) 7528 DiagnoseSelfAssignment(*this, lhs, rhs, OpLoc); 7529 break; 7530 case BO_PtrMemD: 7531 case BO_PtrMemI: 7532 ResultTy = CheckPointerToMemberOperands(lhs, rhs, VK, OpLoc, 7533 Opc == BO_PtrMemI); 7534 break; 7535 case BO_Mul: 7536 case BO_Div: 7537 ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, 7538 Opc == BO_Div); 7539 break; 7540 case BO_Rem: 7541 ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); 7542 break; 7543 case BO_Add: 7544 ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); 7545 break; 7546 case BO_Sub: 7547 ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); 7548 break; 7549 case BO_Shl: 7550 case BO_Shr: 7551 ResultTy = CheckShiftOperands(lhs, rhs, OpLoc); 7552 break; 7553 case BO_LE: 7554 case BO_LT: 7555 case BO_GE: 7556 case BO_GT: 7557 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); 7558 break; 7559 case BO_EQ: 7560 case BO_NE: 7561 ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); 7562 break; 7563 case BO_And: 7564 case BO_Xor: 7565 case BO_Or: 7566 ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); 7567 break; 7568 case BO_LAnd: 7569 case BO_LOr: 7570 ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); 7571 break; 7572 case BO_MulAssign: 7573 case BO_DivAssign: 7574 CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, 7575 Opc == BO_DivAssign); 7576 CompLHSTy = CompResultTy; 7577 if (!CompResultTy.isNull()) 7578 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7579 break; 7580 case BO_RemAssign: 7581 CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); 7582 CompLHSTy = CompResultTy; 7583 if (!CompResultTy.isNull()) 7584 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7585 break; 7586 case BO_AddAssign: 7587 CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); 7588 if (!CompResultTy.isNull()) 7589 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7590 break; 7591 case BO_SubAssign: 7592 CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); 7593 if (!CompResultTy.isNull()) 7594 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7595 break; 7596 case BO_ShlAssign: 7597 case BO_ShrAssign: 7598 CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, true); 7599 CompLHSTy = CompResultTy; 7600 if (!CompResultTy.isNull()) 7601 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7602 break; 7603 case BO_AndAssign: 7604 case BO_XorAssign: 7605 case BO_OrAssign: 7606 CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); 7607 CompLHSTy = CompResultTy; 7608 if (!CompResultTy.isNull()) 7609 ResultTy = CheckAssignmentOperands(lhs, rhs, OpLoc, CompResultTy); 7610 break; 7611 case BO_Comma: 7612 ResultTy = CheckCommaOperands(*this, lhs, rhs, OpLoc); 7613 if (getLangOptions().CPlusPlus) { 7614 VK = rhs->getValueKind(); 7615 OK = rhs->getObjectKind(); 7616 } 7617 break; 7618 } 7619 if (ResultTy.isNull()) 7620 return ExprError(); 7621 if (CompResultTy.isNull()) 7622 return Owned(new (Context) BinaryOperator(lhs, rhs, Opc, ResultTy, 7623 VK, OK, OpLoc)); 7624 7625 if (getLangOptions().CPlusPlus && lhs->getObjectKind() != OK_ObjCProperty) { 7626 VK = VK_LValue; 7627 OK = lhs->getObjectKind(); 7628 } 7629 return Owned(new (Context) CompoundAssignOperator(lhs, rhs, Opc, ResultTy, 7630 VK, OK, CompLHSTy, 7631 CompResultTy, OpLoc)); 7632} 7633 7634/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps 7635/// ParenRange in parentheses. 7636static void SuggestParentheses(Sema &Self, SourceLocation Loc, 7637 const PartialDiagnostic &PD, 7638 const PartialDiagnostic &FirstNote, 7639 SourceRange FirstParenRange, 7640 const PartialDiagnostic &SecondNote, 7641 SourceRange SecondParenRange) { 7642 Self.Diag(Loc, PD); 7643 7644 if (!FirstNote.getDiagID()) 7645 return; 7646 7647 SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); 7648 if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 7649 // We can't display the parentheses, so just return. 7650 return; 7651 } 7652 7653 Self.Diag(Loc, FirstNote) 7654 << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") 7655 << FixItHint::CreateInsertion(EndLoc, ")"); 7656 7657 if (!SecondNote.getDiagID()) 7658 return; 7659 7660 EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); 7661 if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { 7662 // We can't display the parentheses, so just dig the 7663 // warning/error and return. 7664 Self.Diag(Loc, SecondNote); 7665 return; 7666 } 7667 7668 Self.Diag(Loc, SecondNote) 7669 << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") 7670 << FixItHint::CreateInsertion(EndLoc, ")"); 7671} 7672 7673/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison 7674/// operators are mixed in a way that suggests that the programmer forgot that 7675/// comparison operators have higher precedence. The most typical example of 7676/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". 7677static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperatorKind Opc, 7678 SourceLocation OpLoc,Expr *lhs,Expr *rhs){ 7679 typedef BinaryOperator BinOp; 7680 BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), 7681 rhsopc = static_cast<BinOp::Opcode>(-1); 7682 if (BinOp *BO = dyn_cast<BinOp>(lhs)) 7683 lhsopc = BO->getOpcode(); 7684 if (BinOp *BO = dyn_cast<BinOp>(rhs)) 7685 rhsopc = BO->getOpcode(); 7686 7687 // Subs are not binary operators. 7688 if (lhsopc == -1 && rhsopc == -1) 7689 return; 7690 7691 // Bitwise operations are sometimes used as eager logical ops. 7692 // Don't diagnose this. 7693 if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && 7694 (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) 7695 return; 7696 7697 if (BinOp::isComparisonOp(lhsopc)) 7698 SuggestParentheses(Self, OpLoc, 7699 Self.PDiag(diag::warn_precedence_bitwise_rel) 7700 << SourceRange(lhs->getLocStart(), OpLoc) 7701 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), 7702 Self.PDiag(diag::note_precedence_bitwise_first) 7703 << BinOp::getOpcodeStr(Opc), 7704 SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()), 7705 Self.PDiag(diag::note_precedence_bitwise_silence) 7706 << BinOp::getOpcodeStr(lhsopc), 7707 lhs->getSourceRange()); 7708 else if (BinOp::isComparisonOp(rhsopc)) 7709 SuggestParentheses(Self, OpLoc, 7710 Self.PDiag(diag::warn_precedence_bitwise_rel) 7711 << SourceRange(OpLoc, rhs->getLocEnd()) 7712 << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), 7713 Self.PDiag(diag::note_precedence_bitwise_first) 7714 << BinOp::getOpcodeStr(Opc), 7715 SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()), 7716 Self.PDiag(diag::note_precedence_bitwise_silence) 7717 << BinOp::getOpcodeStr(rhsopc), 7718 rhs->getSourceRange()); 7719} 7720 7721/// \brief It accepts a '&&' expr that is inside a '||' one. 7722/// Emit a diagnostic together with a fixit hint that wraps the '&&' expression 7723/// in parentheses. 7724static void 7725EmitDiagnosticForLogicalAndInLogicalOr(Sema &Self, SourceLocation OpLoc, 7726 Expr *E) { 7727 assert(isa<BinaryOperator>(E) && 7728 cast<BinaryOperator>(E)->getOpcode() == BO_LAnd); 7729 SuggestParentheses(Self, OpLoc, 7730 Self.PDiag(diag::warn_logical_and_in_logical_or) 7731 << E->getSourceRange(), 7732 Self.PDiag(diag::note_logical_and_in_logical_or_silence), 7733 E->getSourceRange(), 7734 Self.PDiag(0), SourceRange()); 7735} 7736 7737/// \brief Returns true if the given expression can be evaluated as a constant 7738/// 'true'. 7739static bool EvaluatesAsTrue(Sema &S, Expr *E) { 7740 bool Res; 7741 return E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && Res; 7742} 7743 7744/// \brief Returns true if the given expression can be evaluated as a constant 7745/// 'false'. 7746static bool EvaluatesAsFalse(Sema &S, Expr *E) { 7747 bool Res; 7748 return E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && !Res; 7749} 7750 7751/// \brief Look for '&&' in the left hand of a '||' expr. 7752static void DiagnoseLogicalAndInLogicalOrLHS(Sema &S, SourceLocation OpLoc, 7753 Expr *OrLHS, Expr *OrRHS) { 7754 if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(OrLHS)) { 7755 if (Bop->getOpcode() == BO_LAnd) { 7756 // If it's "a && b || 0" don't warn since the precedence doesn't matter. 7757 if (EvaluatesAsFalse(S, OrRHS)) 7758 return; 7759 // If it's "1 && a || b" don't warn since the precedence doesn't matter. 7760 if (!EvaluatesAsTrue(S, Bop->getLHS())) 7761 return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); 7762 } else if (Bop->getOpcode() == BO_LOr) { 7763 if (BinaryOperator *RBop = dyn_cast<BinaryOperator>(Bop->getRHS())) { 7764 // If it's "a || b && 1 || c" we didn't warn earlier for 7765 // "a || b && 1", but warn now. 7766 if (RBop->getOpcode() == BO_LAnd && EvaluatesAsTrue(S, RBop->getRHS())) 7767 return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, RBop); 7768 } 7769 } 7770 } 7771} 7772 7773/// \brief Look for '&&' in the right hand of a '||' expr. 7774static void DiagnoseLogicalAndInLogicalOrRHS(Sema &S, SourceLocation OpLoc, 7775 Expr *OrLHS, Expr *OrRHS) { 7776 if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(OrRHS)) { 7777 if (Bop->getOpcode() == BO_LAnd) { 7778 // If it's "0 || a && b" don't warn since the precedence doesn't matter. 7779 if (EvaluatesAsFalse(S, OrLHS)) 7780 return; 7781 // If it's "a || b && 1" don't warn since the precedence doesn't matter. 7782 if (!EvaluatesAsTrue(S, Bop->getRHS())) 7783 return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); 7784 } 7785 } 7786} 7787 7788/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky 7789/// precedence. 7790static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, 7791 SourceLocation OpLoc, Expr *lhs, Expr *rhs){ 7792 // Diagnose "arg1 'bitwise' arg2 'eq' arg3". 7793 if (BinaryOperator::isBitwiseOp(Opc)) 7794 return DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); 7795 7796 // Warn about arg1 || arg2 && arg3, as GCC 4.3+ does. 7797 // We don't warn for 'assert(a || b && "bad")' since this is safe. 7798 if (Opc == BO_LOr && !OpLoc.isMacroID()/* Don't warn in macros. */) { 7799 DiagnoseLogicalAndInLogicalOrLHS(Self, OpLoc, lhs, rhs); 7800 DiagnoseLogicalAndInLogicalOrRHS(Self, OpLoc, lhs, rhs); 7801 } 7802} 7803 7804// Binary Operators. 'Tok' is the token for the operator. 7805ExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, 7806 tok::TokenKind Kind, 7807 Expr *lhs, Expr *rhs) { 7808 BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Kind); 7809 assert((lhs != 0) && "ActOnBinOp(): missing left expression"); 7810 assert((rhs != 0) && "ActOnBinOp(): missing right expression"); 7811 7812 // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" 7813 DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); 7814 7815 return BuildBinOp(S, TokLoc, Opc, lhs, rhs); 7816} 7817 7818ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, 7819 BinaryOperatorKind Opc, 7820 Expr *lhs, Expr *rhs) { 7821 if (getLangOptions().CPlusPlus) { 7822 bool UseBuiltinOperator; 7823 7824 if (lhs->isTypeDependent() || rhs->isTypeDependent()) { 7825 UseBuiltinOperator = false; 7826 } else if (Opc == BO_Assign && lhs->getObjectKind() == OK_ObjCProperty) { 7827 UseBuiltinOperator = true; 7828 } else { 7829 UseBuiltinOperator = !lhs->getType()->isOverloadableType() && 7830 !rhs->getType()->isOverloadableType(); 7831 } 7832 7833 if (!UseBuiltinOperator) { 7834 // Find all of the overloaded operators visible from this 7835 // point. We perform both an operator-name lookup from the local 7836 // scope and an argument-dependent lookup based on the types of 7837 // the arguments. 7838 UnresolvedSet<16> Functions; 7839 OverloadedOperatorKind OverOp 7840 = BinaryOperator::getOverloadedOperator(Opc); 7841 if (S && OverOp != OO_None) 7842 LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), 7843 Functions); 7844 7845 // Build the (potentially-overloaded, potentially-dependent) 7846 // binary operation. 7847 return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); 7848 } 7849 } 7850 7851 // Build a built-in binary operation. 7852 return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); 7853} 7854 7855ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, 7856 UnaryOperatorKind Opc, 7857 Expr *Input) { 7858 ExprValueKind VK = VK_RValue; 7859 ExprObjectKind OK = OK_Ordinary; 7860 QualType resultType; 7861 switch (Opc) { 7862 case UO_PreInc: 7863 case UO_PreDec: 7864 case UO_PostInc: 7865 case UO_PostDec: 7866 resultType = CheckIncrementDecrementOperand(*this, Input, VK, OpLoc, 7867 Opc == UO_PreInc || 7868 Opc == UO_PostInc, 7869 Opc == UO_PreInc || 7870 Opc == UO_PreDec); 7871 break; 7872 case UO_AddrOf: 7873 resultType = CheckAddressOfOperand(*this, Input, OpLoc); 7874 break; 7875 case UO_Deref: 7876 DefaultFunctionArrayLvalueConversion(Input); 7877 resultType = CheckIndirectionOperand(*this, Input, VK, OpLoc); 7878 break; 7879 case UO_Plus: 7880 case UO_Minus: 7881 UsualUnaryConversions(Input); 7882 resultType = Input->getType(); 7883 if (resultType->isDependentType()) 7884 break; 7885 if (resultType->isArithmeticType() || // C99 6.5.3.3p1 7886 resultType->isVectorType()) 7887 break; 7888 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 7889 resultType->isEnumeralType()) 7890 break; 7891 else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 7892 Opc == UO_Plus && 7893 resultType->isPointerType()) 7894 break; 7895 else if (resultType->isPlaceholderType()) { 7896 ExprResult PR = CheckPlaceholderExpr(Input, OpLoc); 7897 if (PR.isInvalid()) return ExprError(); 7898 return CreateBuiltinUnaryOp(OpLoc, Opc, PR.take()); 7899 } 7900 7901 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 7902 << resultType << Input->getSourceRange()); 7903 case UO_Not: // bitwise complement 7904 UsualUnaryConversions(Input); 7905 resultType = Input->getType(); 7906 if (resultType->isDependentType()) 7907 break; 7908 // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. 7909 if (resultType->isComplexType() || resultType->isComplexIntegerType()) 7910 // C99 does not support '~' for complex conjugation. 7911 Diag(OpLoc, diag::ext_integer_complement_complex) 7912 << resultType << Input->getSourceRange(); 7913 else if (resultType->hasIntegerRepresentation()) 7914 break; 7915 else if (resultType->isPlaceholderType()) { 7916 ExprResult PR = CheckPlaceholderExpr(Input, OpLoc); 7917 if (PR.isInvalid()) return ExprError(); 7918 return CreateBuiltinUnaryOp(OpLoc, Opc, PR.take()); 7919 } else { 7920 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 7921 << resultType << Input->getSourceRange()); 7922 } 7923 break; 7924 case UO_LNot: // logical negation 7925 // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). 7926 DefaultFunctionArrayLvalueConversion(Input); 7927 resultType = Input->getType(); 7928 if (resultType->isDependentType()) 7929 break; 7930 if (resultType->isScalarType()) { // C99 6.5.3.3p1 7931 // ok, fallthrough 7932 } else if (resultType->isPlaceholderType()) { 7933 ExprResult PR = CheckPlaceholderExpr(Input, OpLoc); 7934 if (PR.isInvalid()) return ExprError(); 7935 return CreateBuiltinUnaryOp(OpLoc, Opc, PR.take()); 7936 } else { 7937 return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) 7938 << resultType << Input->getSourceRange()); 7939 } 7940 7941 // LNot always has type int. C99 6.5.3.3p5. 7942 // In C++, it's bool. C++ 5.3.1p8 7943 resultType = getLangOptions().CPlusPlus ? Context.BoolTy : Context.IntTy; 7944 break; 7945 case UO_Real: 7946 case UO_Imag: 7947 resultType = CheckRealImagOperand(*this, Input, OpLoc, Opc == UO_Real); 7948 // _Real and _Imag map ordinary l-values into ordinary l-values. 7949 if (Input->getValueKind() != VK_RValue && 7950 Input->getObjectKind() == OK_Ordinary) 7951 VK = Input->getValueKind(); 7952 break; 7953 case UO_Extension: 7954 resultType = Input->getType(); 7955 VK = Input->getValueKind(); 7956 OK = Input->getObjectKind(); 7957 break; 7958 } 7959 if (resultType.isNull()) 7960 return ExprError(); 7961 7962 return Owned(new (Context) UnaryOperator(Input, Opc, resultType, 7963 VK, OK, OpLoc)); 7964} 7965 7966ExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, 7967 UnaryOperatorKind Opc, 7968 Expr *Input) { 7969 if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && 7970 UnaryOperator::getOverloadedOperator(Opc) != OO_None) { 7971 // Find all of the overloaded operators visible from this 7972 // point. We perform both an operator-name lookup from the local 7973 // scope and an argument-dependent lookup based on the types of 7974 // the arguments. 7975 UnresolvedSet<16> Functions; 7976 OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); 7977 if (S && OverOp != OO_None) 7978 LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), 7979 Functions); 7980 7981 return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); 7982 } 7983 7984 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 7985} 7986 7987// Unary Operators. 'Tok' is the token for the operator. 7988ExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, 7989 tok::TokenKind Op, Expr *Input) { 7990 return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); 7991} 7992 7993/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". 7994ExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, 7995 SourceLocation LabLoc, 7996 IdentifierInfo *LabelII) { 7997 // Look up the record for this label identifier. 7998 LabelStmt *&LabelDecl = getCurFunction()->LabelMap[LabelII]; 7999 8000 // If we haven't seen this label yet, create a forward reference. It 8001 // will be validated and/or cleaned up in ActOnFinishFunctionBody. 8002 if (LabelDecl == 0) 8003 LabelDecl = new (Context) LabelStmt(LabLoc, LabelII, 0); 8004 8005 LabelDecl->setUsed(); 8006 // Create the AST node. The address of a label always has type 'void*'. 8007 return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, LabelDecl, 8008 Context.getPointerType(Context.VoidTy))); 8009} 8010 8011ExprResult 8012Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, 8013 SourceLocation RPLoc) { // "({..})" 8014 assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); 8015 CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); 8016 8017 bool isFileScope 8018 = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); 8019 if (isFileScope) 8020 return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); 8021 8022 // FIXME: there are a variety of strange constraints to enforce here, for 8023 // example, it is not possible to goto into a stmt expression apparently. 8024 // More semantic analysis is needed. 8025 8026 // If there are sub stmts in the compound stmt, take the type of the last one 8027 // as the type of the stmtexpr. 8028 QualType Ty = Context.VoidTy; 8029 bool StmtExprMayBindToTemp = false; 8030 if (!Compound->body_empty()) { 8031 Stmt *LastStmt = Compound->body_back(); 8032 LabelStmt *LastLabelStmt = 0; 8033 // If LastStmt is a label, skip down through into the body. 8034 while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) { 8035 LastLabelStmt = Label; 8036 LastStmt = Label->getSubStmt(); 8037 } 8038 if (Expr *LastExpr = dyn_cast<Expr>(LastStmt)) { 8039 // Do function/array conversion on the last expression, but not 8040 // lvalue-to-rvalue. However, initialize an unqualified type. 8041 DefaultFunctionArrayConversion(LastExpr); 8042 Ty = LastExpr->getType().getUnqualifiedType(); 8043 8044 if (!Ty->isDependentType() && !LastExpr->isTypeDependent()) { 8045 ExprResult Res = PerformCopyInitialization( 8046 InitializedEntity::InitializeResult(LPLoc, 8047 Ty, 8048 false), 8049 SourceLocation(), 8050 Owned(LastExpr)); 8051 if (Res.isInvalid()) 8052 return ExprError(); 8053 if ((LastExpr = Res.takeAs<Expr>())) { 8054 if (!LastLabelStmt) 8055 Compound->setLastStmt(LastExpr); 8056 else 8057 LastLabelStmt->setSubStmt(LastExpr); 8058 StmtExprMayBindToTemp = true; 8059 } 8060 } 8061 } 8062 } 8063 8064 // FIXME: Check that expression type is complete/non-abstract; statement 8065 // expressions are not lvalues. 8066 Expr *ResStmtExpr = new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc); 8067 if (StmtExprMayBindToTemp) 8068 return MaybeBindToTemporary(ResStmtExpr); 8069 return Owned(ResStmtExpr); 8070} 8071 8072ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, 8073 TypeSourceInfo *TInfo, 8074 OffsetOfComponent *CompPtr, 8075 unsigned NumComponents, 8076 SourceLocation RParenLoc) { 8077 QualType ArgTy = TInfo->getType(); 8078 bool Dependent = ArgTy->isDependentType(); 8079 SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); 8080 8081 // We must have at least one component that refers to the type, and the first 8082 // one is known to be a field designator. Verify that the ArgTy represents 8083 // a struct/union/class. 8084 if (!Dependent && !ArgTy->isRecordType()) 8085 return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) 8086 << ArgTy << TypeRange); 8087 8088 // Type must be complete per C99 7.17p3 because a declaring a variable 8089 // with an incomplete type would be ill-formed. 8090 if (!Dependent 8091 && RequireCompleteType(BuiltinLoc, ArgTy, 8092 PDiag(diag::err_offsetof_incomplete_type) 8093 << TypeRange)) 8094 return ExprError(); 8095 8096 // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a 8097 // GCC extension, diagnose them. 8098 // FIXME: This diagnostic isn't actually visible because the location is in 8099 // a system header! 8100 if (NumComponents != 1) 8101 Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) 8102 << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); 8103 8104 bool DidWarnAboutNonPOD = false; 8105 QualType CurrentType = ArgTy; 8106 typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; 8107 llvm::SmallVector<OffsetOfNode, 4> Comps; 8108 llvm::SmallVector<Expr*, 4> Exprs; 8109 for (unsigned i = 0; i != NumComponents; ++i) { 8110 const OffsetOfComponent &OC = CompPtr[i]; 8111 if (OC.isBrackets) { 8112 // Offset of an array sub-field. TODO: Should we allow vector elements? 8113 if (!CurrentType->isDependentType()) { 8114 const ArrayType *AT = Context.getAsArrayType(CurrentType); 8115 if(!AT) 8116 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) 8117 << CurrentType); 8118 CurrentType = AT->getElementType(); 8119 } else 8120 CurrentType = Context.DependentTy; 8121 8122 // The expression must be an integral expression. 8123 // FIXME: An integral constant expression? 8124 Expr *Idx = static_cast<Expr*>(OC.U.E); 8125 if (!Idx->isTypeDependent() && !Idx->isValueDependent() && 8126 !Idx->getType()->isIntegerType()) 8127 return ExprError(Diag(Idx->getLocStart(), 8128 diag::err_typecheck_subscript_not_integer) 8129 << Idx->getSourceRange()); 8130 8131 // Record this array index. 8132 Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); 8133 Exprs.push_back(Idx); 8134 continue; 8135 } 8136 8137 // Offset of a field. 8138 if (CurrentType->isDependentType()) { 8139 // We have the offset of a field, but we can't look into the dependent 8140 // type. Just record the identifier of the field. 8141 Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); 8142 CurrentType = Context.DependentTy; 8143 continue; 8144 } 8145 8146 // We need to have a complete type to look into. 8147 if (RequireCompleteType(OC.LocStart, CurrentType, 8148 diag::err_offsetof_incomplete_type)) 8149 return ExprError(); 8150 8151 // Look for the designated field. 8152 const RecordType *RC = CurrentType->getAs<RecordType>(); 8153 if (!RC) 8154 return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) 8155 << CurrentType); 8156 RecordDecl *RD = RC->getDecl(); 8157 8158 // C++ [lib.support.types]p5: 8159 // The macro offsetof accepts a restricted set of type arguments in this 8160 // International Standard. type shall be a POD structure or a POD union 8161 // (clause 9). 8162 if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 8163 if (!CRD->isPOD() && !DidWarnAboutNonPOD && 8164 DiagRuntimeBehavior(BuiltinLoc, 8165 PDiag(diag::warn_offsetof_non_pod_type) 8166 << SourceRange(CompPtr[0].LocStart, OC.LocEnd) 8167 << CurrentType)) 8168 DidWarnAboutNonPOD = true; 8169 } 8170 8171 // Look for the field. 8172 LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); 8173 LookupQualifiedName(R, RD); 8174 FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); 8175 IndirectFieldDecl *IndirectMemberDecl = 0; 8176 if (!MemberDecl) { 8177 if ((IndirectMemberDecl = R.getAsSingle<IndirectFieldDecl>())) 8178 MemberDecl = IndirectMemberDecl->getAnonField(); 8179 } 8180 8181 if (!MemberDecl) 8182 return ExprError(Diag(BuiltinLoc, diag::err_no_member) 8183 << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, 8184 OC.LocEnd)); 8185 8186 // C99 7.17p3: 8187 // (If the specified member is a bit-field, the behavior is undefined.) 8188 // 8189 // We diagnose this as an error. 8190 if (MemberDecl->getBitWidth()) { 8191 Diag(OC.LocEnd, diag::err_offsetof_bitfield) 8192 << MemberDecl->getDeclName() 8193 << SourceRange(BuiltinLoc, RParenLoc); 8194 Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); 8195 return ExprError(); 8196 } 8197 8198 RecordDecl *Parent = MemberDecl->getParent(); 8199 if (IndirectMemberDecl) 8200 Parent = cast<RecordDecl>(IndirectMemberDecl->getDeclContext()); 8201 8202 // If the member was found in a base class, introduce OffsetOfNodes for 8203 // the base class indirections. 8204 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 8205 /*DetectVirtual=*/false); 8206 if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { 8207 CXXBasePath &Path = Paths.front(); 8208 for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); 8209 B != BEnd; ++B) 8210 Comps.push_back(OffsetOfNode(B->Base)); 8211 } 8212 8213 if (IndirectMemberDecl) { 8214 for (IndirectFieldDecl::chain_iterator FI = 8215 IndirectMemberDecl->chain_begin(), 8216 FEnd = IndirectMemberDecl->chain_end(); FI != FEnd; FI++) { 8217 assert(isa<FieldDecl>(*FI)); 8218 Comps.push_back(OffsetOfNode(OC.LocStart, 8219 cast<FieldDecl>(*FI), OC.LocEnd)); 8220 } 8221 } else 8222 Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); 8223 8224 CurrentType = MemberDecl->getType().getNonReferenceType(); 8225 } 8226 8227 return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, 8228 TInfo, Comps.data(), Comps.size(), 8229 Exprs.data(), Exprs.size(), RParenLoc)); 8230} 8231 8232ExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, 8233 SourceLocation BuiltinLoc, 8234 SourceLocation TypeLoc, 8235 ParsedType argty, 8236 OffsetOfComponent *CompPtr, 8237 unsigned NumComponents, 8238 SourceLocation RPLoc) { 8239 8240 TypeSourceInfo *ArgTInfo; 8241 QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); 8242 if (ArgTy.isNull()) 8243 return ExprError(); 8244 8245 if (!ArgTInfo) 8246 ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); 8247 8248 return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, 8249 RPLoc); 8250} 8251 8252 8253ExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, 8254 Expr *CondExpr, 8255 Expr *LHSExpr, Expr *RHSExpr, 8256 SourceLocation RPLoc) { 8257 assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); 8258 8259 ExprValueKind VK = VK_RValue; 8260 ExprObjectKind OK = OK_Ordinary; 8261 QualType resType; 8262 bool ValueDependent = false; 8263 if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { 8264 resType = Context.DependentTy; 8265 ValueDependent = true; 8266 } else { 8267 // The conditional expression is required to be a constant expression. 8268 llvm::APSInt condEval(32); 8269 SourceLocation ExpLoc; 8270 if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) 8271 return ExprError(Diag(ExpLoc, 8272 diag::err_typecheck_choose_expr_requires_constant) 8273 << CondExpr->getSourceRange()); 8274 8275 // If the condition is > zero, then the AST type is the same as the LSHExpr. 8276 Expr *ActiveExpr = condEval.getZExtValue() ? LHSExpr : RHSExpr; 8277 8278 resType = ActiveExpr->getType(); 8279 ValueDependent = ActiveExpr->isValueDependent(); 8280 VK = ActiveExpr->getValueKind(); 8281 OK = ActiveExpr->getObjectKind(); 8282 } 8283 8284 return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, 8285 resType, VK, OK, RPLoc, 8286 resType->isDependentType(), 8287 ValueDependent)); 8288} 8289 8290//===----------------------------------------------------------------------===// 8291// Clang Extensions. 8292//===----------------------------------------------------------------------===// 8293 8294/// ActOnBlockStart - This callback is invoked when a block literal is started. 8295void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { 8296 BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); 8297 PushBlockScope(BlockScope, Block); 8298 CurContext->addDecl(Block); 8299 if (BlockScope) 8300 PushDeclContext(BlockScope, Block); 8301 else 8302 CurContext = Block; 8303} 8304 8305void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { 8306 assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); 8307 assert(ParamInfo.getContext() == Declarator::BlockLiteralContext); 8308 BlockScopeInfo *CurBlock = getCurBlock(); 8309 8310 TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); 8311 QualType T = Sig->getType(); 8312 8313 // GetTypeForDeclarator always produces a function type for a block 8314 // literal signature. Furthermore, it is always a FunctionProtoType 8315 // unless the function was written with a typedef. 8316 assert(T->isFunctionType() && 8317 "GetTypeForDeclarator made a non-function block signature"); 8318 8319 // Look for an explicit signature in that function type. 8320 FunctionProtoTypeLoc ExplicitSignature; 8321 8322 TypeLoc tmp = Sig->getTypeLoc().IgnoreParens(); 8323 if (isa<FunctionProtoTypeLoc>(tmp)) { 8324 ExplicitSignature = cast<FunctionProtoTypeLoc>(tmp); 8325 8326 // Check whether that explicit signature was synthesized by 8327 // GetTypeForDeclarator. If so, don't save that as part of the 8328 // written signature. 8329 if (ExplicitSignature.getLParenLoc() == 8330 ExplicitSignature.getRParenLoc()) { 8331 // This would be much cheaper if we stored TypeLocs instead of 8332 // TypeSourceInfos. 8333 TypeLoc Result = ExplicitSignature.getResultLoc(); 8334 unsigned Size = Result.getFullDataSize(); 8335 Sig = Context.CreateTypeSourceInfo(Result.getType(), Size); 8336 Sig->getTypeLoc().initializeFullCopy(Result, Size); 8337 8338 ExplicitSignature = FunctionProtoTypeLoc(); 8339 } 8340 } 8341 8342 CurBlock->TheDecl->setSignatureAsWritten(Sig); 8343 CurBlock->FunctionType = T; 8344 8345 const FunctionType *Fn = T->getAs<FunctionType>(); 8346 QualType RetTy = Fn->getResultType(); 8347 bool isVariadic = 8348 (isa<FunctionProtoType>(Fn) && cast<FunctionProtoType>(Fn)->isVariadic()); 8349 8350 CurBlock->TheDecl->setIsVariadic(isVariadic); 8351 8352 // Don't allow returning a objc interface by value. 8353 if (RetTy->isObjCObjectType()) { 8354 Diag(ParamInfo.getSourceRange().getBegin(), 8355 diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; 8356 return; 8357 } 8358 8359 // Context.DependentTy is used as a placeholder for a missing block 8360 // return type. TODO: what should we do with declarators like: 8361 // ^ * { ... } 8362 // If the answer is "apply template argument deduction".... 8363 if (RetTy != Context.DependentTy) 8364 CurBlock->ReturnType = RetTy; 8365 8366 // Push block parameters from the declarator if we had them. 8367 llvm::SmallVector<ParmVarDecl*, 8> Params; 8368 if (ExplicitSignature) { 8369 for (unsigned I = 0, E = ExplicitSignature.getNumArgs(); I != E; ++I) { 8370 ParmVarDecl *Param = ExplicitSignature.getArg(I); 8371 if (Param->getIdentifier() == 0 && 8372 !Param->isImplicit() && 8373 !Param->isInvalidDecl() && 8374 !getLangOptions().CPlusPlus) 8375 Diag(Param->getLocation(), diag::err_parameter_name_omitted); 8376 Params.push_back(Param); 8377 } 8378 8379 // Fake up parameter variables if we have a typedef, like 8380 // ^ fntype { ... } 8381 } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { 8382 for (FunctionProtoType::arg_type_iterator 8383 I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { 8384 ParmVarDecl *Param = 8385 BuildParmVarDeclForTypedef(CurBlock->TheDecl, 8386 ParamInfo.getSourceRange().getBegin(), 8387 *I); 8388 Params.push_back(Param); 8389 } 8390 } 8391 8392 // Set the parameters on the block decl. 8393 if (!Params.empty()) { 8394 CurBlock->TheDecl->setParams(Params.data(), Params.size()); 8395 CheckParmsForFunctionDef(CurBlock->TheDecl->param_begin(), 8396 CurBlock->TheDecl->param_end(), 8397 /*CheckParameterNames=*/false); 8398 } 8399 8400 // Finally we can process decl attributes. 8401 ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); 8402 8403 if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { 8404 Diag(ParamInfo.getAttributes()->getLoc(), 8405 diag::warn_attribute_sentinel_not_variadic) << 1; 8406 // FIXME: remove the attribute. 8407 } 8408 8409 // Put the parameter variables in scope. We can bail out immediately 8410 // if we don't have any. 8411 if (Params.empty()) 8412 return; 8413 8414 for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), 8415 E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { 8416 (*AI)->setOwningFunction(CurBlock->TheDecl); 8417 8418 // If this has an identifier, add it to the scope stack. 8419 if ((*AI)->getIdentifier()) { 8420 CheckShadow(CurBlock->TheScope, *AI); 8421 8422 PushOnScopeChains(*AI, CurBlock->TheScope); 8423 } 8424 } 8425} 8426 8427/// ActOnBlockError - If there is an error parsing a block, this callback 8428/// is invoked to pop the information about the block from the action impl. 8429void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { 8430 // Pop off CurBlock, handle nested blocks. 8431 PopDeclContext(); 8432 PopFunctionOrBlockScope(); 8433} 8434 8435/// ActOnBlockStmtExpr - This is called when the body of a block statement 8436/// literal was successfully completed. ^(int x){...} 8437ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, 8438 Stmt *Body, Scope *CurScope) { 8439 // If blocks are disabled, emit an error. 8440 if (!LangOpts.Blocks) 8441 Diag(CaretLoc, diag::err_blocks_disable); 8442 8443 BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); 8444 8445 PopDeclContext(); 8446 8447 QualType RetTy = Context.VoidTy; 8448 if (!BSI->ReturnType.isNull()) 8449 RetTy = BSI->ReturnType; 8450 8451 bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); 8452 QualType BlockTy; 8453 8454 // If the user wrote a function type in some form, try to use that. 8455 if (!BSI->FunctionType.isNull()) { 8456 const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); 8457 8458 FunctionType::ExtInfo Ext = FTy->getExtInfo(); 8459 if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); 8460 8461 // Turn protoless block types into nullary block types. 8462 if (isa<FunctionNoProtoType>(FTy)) { 8463 FunctionProtoType::ExtProtoInfo EPI; 8464 EPI.ExtInfo = Ext; 8465 BlockTy = Context.getFunctionType(RetTy, 0, 0, EPI); 8466 8467 // Otherwise, if we don't need to change anything about the function type, 8468 // preserve its sugar structure. 8469 } else if (FTy->getResultType() == RetTy && 8470 (!NoReturn || FTy->getNoReturnAttr())) { 8471 BlockTy = BSI->FunctionType; 8472 8473 // Otherwise, make the minimal modifications to the function type. 8474 } else { 8475 const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); 8476 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 8477 EPI.TypeQuals = 0; // FIXME: silently? 8478 EPI.ExtInfo = Ext; 8479 BlockTy = Context.getFunctionType(RetTy, 8480 FPT->arg_type_begin(), 8481 FPT->getNumArgs(), 8482 EPI); 8483 } 8484 8485 // If we don't have a function type, just build one from nothing. 8486 } else { 8487 FunctionProtoType::ExtProtoInfo EPI; 8488 EPI.ExtInfo = FunctionType::ExtInfo(NoReturn, 0, CC_Default); 8489 BlockTy = Context.getFunctionType(RetTy, 0, 0, EPI); 8490 } 8491 8492 DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), 8493 BSI->TheDecl->param_end()); 8494 BlockTy = Context.getBlockPointerType(BlockTy); 8495 8496 // If needed, diagnose invalid gotos and switches in the block. 8497 if (getCurFunction()->NeedsScopeChecking() && !hasAnyErrorsInThisFunction()) 8498 DiagnoseInvalidJumps(cast<CompoundStmt>(Body)); 8499 8500 BSI->TheDecl->setBody(cast<CompoundStmt>(Body)); 8501 8502 bool Good = true; 8503 // Check goto/label use. 8504 for (llvm::DenseMap<IdentifierInfo*, LabelStmt*>::iterator 8505 I = BSI->LabelMap.begin(), E = BSI->LabelMap.end(); I != E; ++I) { 8506 LabelStmt *L = I->second; 8507 8508 // Verify that we have no forward references left. If so, there was a goto 8509 // or address of a label taken, but no definition of it. 8510 if (L->getSubStmt() != 0) { 8511 if (!L->isUsed()) 8512 Diag(L->getIdentLoc(), diag::warn_unused_label) << L->getName(); 8513 continue; 8514 } 8515 8516 // Emit error. 8517 Diag(L->getIdentLoc(), diag::err_undeclared_label_use) << L->getName(); 8518 Good = false; 8519 } 8520 if (!Good) { 8521 PopFunctionOrBlockScope(); 8522 return ExprError(); 8523 } 8524 8525 BlockExpr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy, 8526 BSI->hasBlockDeclRefExprs); 8527 8528 // Issue any analysis-based warnings. 8529 const sema::AnalysisBasedWarnings::Policy &WP = 8530 AnalysisWarnings.getDefaultPolicy(); 8531 AnalysisWarnings.IssueWarnings(WP, Result); 8532 8533 PopFunctionOrBlockScope(); 8534 return Owned(Result); 8535} 8536 8537ExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, 8538 Expr *expr, ParsedType type, 8539 SourceLocation RPLoc) { 8540 TypeSourceInfo *TInfo; 8541 GetTypeFromParser(type, &TInfo); 8542 return BuildVAArgExpr(BuiltinLoc, expr, TInfo, RPLoc); 8543} 8544 8545ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, 8546 Expr *E, TypeSourceInfo *TInfo, 8547 SourceLocation RPLoc) { 8548 Expr *OrigExpr = E; 8549 8550 // Get the va_list type 8551 QualType VaListType = Context.getBuiltinVaListType(); 8552 if (VaListType->isArrayType()) { 8553 // Deal with implicit array decay; for example, on x86-64, 8554 // va_list is an array, but it's supposed to decay to 8555 // a pointer for va_arg. 8556 VaListType = Context.getArrayDecayedType(VaListType); 8557 // Make sure the input expression also decays appropriately. 8558 UsualUnaryConversions(E); 8559 } else { 8560 // Otherwise, the va_list argument must be an l-value because 8561 // it is modified by va_arg. 8562 if (!E->isTypeDependent() && 8563 CheckForModifiableLvalue(E, BuiltinLoc, *this)) 8564 return ExprError(); 8565 } 8566 8567 if (!E->isTypeDependent() && 8568 !Context.hasSameType(VaListType, E->getType())) { 8569 return ExprError(Diag(E->getLocStart(), 8570 diag::err_first_argument_to_va_arg_not_of_type_va_list) 8571 << OrigExpr->getType() << E->getSourceRange()); 8572 } 8573 8574 // FIXME: Check that type is complete/non-abstract 8575 // FIXME: Warn if a non-POD type is passed in. 8576 8577 QualType T = TInfo->getType().getNonLValueExprType(Context); 8578 return Owned(new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T)); 8579} 8580 8581ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { 8582 // The type of __null will be int or long, depending on the size of 8583 // pointers on the target. 8584 QualType Ty; 8585 unsigned pw = Context.Target.getPointerWidth(0); 8586 if (pw == Context.Target.getIntWidth()) 8587 Ty = Context.IntTy; 8588 else if (pw == Context.Target.getLongWidth()) 8589 Ty = Context.LongTy; 8590 else if (pw == Context.Target.getLongLongWidth()) 8591 Ty = Context.LongLongTy; 8592 else { 8593 assert(!"I don't know size of pointer!"); 8594 Ty = Context.IntTy; 8595 } 8596 8597 return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); 8598} 8599 8600static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, 8601 Expr *SrcExpr, FixItHint &Hint) { 8602 if (!SemaRef.getLangOptions().ObjC1) 8603 return; 8604 8605 const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); 8606 if (!PT) 8607 return; 8608 8609 // Check if the destination is of type 'id'. 8610 if (!PT->isObjCIdType()) { 8611 // Check if the destination is the 'NSString' interface. 8612 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); 8613 if (!ID || !ID->getIdentifier()->isStr("NSString")) 8614 return; 8615 } 8616 8617 // Strip off any parens and casts. 8618 StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); 8619 if (!SL || SL->isWide()) 8620 return; 8621 8622 Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); 8623} 8624 8625bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, 8626 SourceLocation Loc, 8627 QualType DstType, QualType SrcType, 8628 Expr *SrcExpr, AssignmentAction Action, 8629 bool *Complained) { 8630 if (Complained) 8631 *Complained = false; 8632 8633 // Decode the result (notice that AST's are still created for extensions). 8634 bool isInvalid = false; 8635 unsigned DiagKind; 8636 FixItHint Hint; 8637 8638 switch (ConvTy) { 8639 default: assert(0 && "Unknown conversion type"); 8640 case Compatible: return false; 8641 case PointerToInt: 8642 DiagKind = diag::ext_typecheck_convert_pointer_int; 8643 break; 8644 case IntToPointer: 8645 DiagKind = diag::ext_typecheck_convert_int_pointer; 8646 break; 8647 case IncompatiblePointer: 8648 MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); 8649 DiagKind = diag::ext_typecheck_convert_incompatible_pointer; 8650 break; 8651 case IncompatiblePointerSign: 8652 DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; 8653 break; 8654 case FunctionVoidPointer: 8655 DiagKind = diag::ext_typecheck_convert_pointer_void_func; 8656 break; 8657 case CompatiblePointerDiscardsQualifiers: 8658 // If the qualifiers lost were because we were applying the 8659 // (deprecated) C++ conversion from a string literal to a char* 8660 // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: 8661 // Ideally, this check would be performed in 8662 // CheckPointerTypesForAssignment. However, that would require a 8663 // bit of refactoring (so that the second argument is an 8664 // expression, rather than a type), which should be done as part 8665 // of a larger effort to fix CheckPointerTypesForAssignment for 8666 // C++ semantics. 8667 if (getLangOptions().CPlusPlus && 8668 IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) 8669 return false; 8670 DiagKind = diag::ext_typecheck_convert_discards_qualifiers; 8671 break; 8672 case IncompatibleNestedPointerQualifiers: 8673 DiagKind = diag::ext_nested_pointer_qualifier_mismatch; 8674 break; 8675 case IntToBlockPointer: 8676 DiagKind = diag::err_int_to_block_pointer; 8677 break; 8678 case IncompatibleBlockPointer: 8679 DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; 8680 break; 8681 case IncompatibleObjCQualifiedId: 8682 // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since 8683 // it can give a more specific diagnostic. 8684 DiagKind = diag::warn_incompatible_qualified_id; 8685 break; 8686 case IncompatibleVectors: 8687 DiagKind = diag::warn_incompatible_vectors; 8688 break; 8689 case Incompatible: 8690 DiagKind = diag::err_typecheck_convert_incompatible; 8691 isInvalid = true; 8692 break; 8693 } 8694 8695 QualType FirstType, SecondType; 8696 switch (Action) { 8697 case AA_Assigning: 8698 case AA_Initializing: 8699 // The destination type comes first. 8700 FirstType = DstType; 8701 SecondType = SrcType; 8702 break; 8703 8704 case AA_Returning: 8705 case AA_Passing: 8706 case AA_Converting: 8707 case AA_Sending: 8708 case AA_Casting: 8709 // The source type comes first. 8710 FirstType = SrcType; 8711 SecondType = DstType; 8712 break; 8713 } 8714 8715 Diag(Loc, DiagKind) << FirstType << SecondType << Action 8716 << SrcExpr->getSourceRange() << Hint; 8717 if (Complained) 8718 *Complained = true; 8719 return isInvalid; 8720} 8721 8722bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ 8723 llvm::APSInt ICEResult; 8724 if (E->isIntegerConstantExpr(ICEResult, Context)) { 8725 if (Result) 8726 *Result = ICEResult; 8727 return false; 8728 } 8729 8730 Expr::EvalResult EvalResult; 8731 8732 if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || 8733 EvalResult.HasSideEffects) { 8734 Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); 8735 8736 if (EvalResult.Diag) { 8737 // We only show the note if it's not the usual "invalid subexpression" 8738 // or if it's actually in a subexpression. 8739 if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || 8740 E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) 8741 Diag(EvalResult.DiagLoc, EvalResult.Diag); 8742 } 8743 8744 return true; 8745 } 8746 8747 Diag(E->getExprLoc(), diag::ext_expr_not_ice) << 8748 E->getSourceRange(); 8749 8750 if (EvalResult.Diag && 8751 Diags.getDiagnosticLevel(diag::ext_expr_not_ice, EvalResult.DiagLoc) 8752 != Diagnostic::Ignored) 8753 Diag(EvalResult.DiagLoc, EvalResult.Diag); 8754 8755 if (Result) 8756 *Result = EvalResult.Val.getInt(); 8757 return false; 8758} 8759 8760void 8761Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { 8762 ExprEvalContexts.push_back( 8763 ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); 8764} 8765 8766void 8767Sema::PopExpressionEvaluationContext() { 8768 // Pop the current expression evaluation context off the stack. 8769 ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); 8770 ExprEvalContexts.pop_back(); 8771 8772 if (Rec.Context == PotentiallyPotentiallyEvaluated) { 8773 if (Rec.PotentiallyReferenced) { 8774 // Mark any remaining declarations in the current position of the stack 8775 // as "referenced". If they were not meant to be referenced, semantic 8776 // analysis would have eliminated them (e.g., in ActOnCXXTypeId). 8777 for (PotentiallyReferencedDecls::iterator 8778 I = Rec.PotentiallyReferenced->begin(), 8779 IEnd = Rec.PotentiallyReferenced->end(); 8780 I != IEnd; ++I) 8781 MarkDeclarationReferenced(I->first, I->second); 8782 } 8783 8784 if (Rec.PotentiallyDiagnosed) { 8785 // Emit any pending diagnostics. 8786 for (PotentiallyEmittedDiagnostics::iterator 8787 I = Rec.PotentiallyDiagnosed->begin(), 8788 IEnd = Rec.PotentiallyDiagnosed->end(); 8789 I != IEnd; ++I) 8790 Diag(I->first, I->second); 8791 } 8792 } 8793 8794 // When are coming out of an unevaluated context, clear out any 8795 // temporaries that we may have created as part of the evaluation of 8796 // the expression in that context: they aren't relevant because they 8797 // will never be constructed. 8798 if (Rec.Context == Unevaluated && 8799 ExprTemporaries.size() > Rec.NumTemporaries) 8800 ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, 8801 ExprTemporaries.end()); 8802 8803 // Destroy the popped expression evaluation record. 8804 Rec.Destroy(); 8805} 8806 8807/// \brief Note that the given declaration was referenced in the source code. 8808/// 8809/// This routine should be invoke whenever a given declaration is referenced 8810/// in the source code, and where that reference occurred. If this declaration 8811/// reference means that the the declaration is used (C++ [basic.def.odr]p2, 8812/// C99 6.9p3), then the declaration will be marked as used. 8813/// 8814/// \param Loc the location where the declaration was referenced. 8815/// 8816/// \param D the declaration that has been referenced by the source code. 8817void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { 8818 assert(D && "No declaration?"); 8819 8820 if (D->isUsed(false)) 8821 return; 8822 8823 // Mark a parameter or variable declaration "used", regardless of whether we're in a 8824 // template or not. The reason for this is that unevaluated expressions 8825 // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and 8826 // -Wunused-parameters) 8827 if (isa<ParmVarDecl>(D) || 8828 (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { 8829 D->setUsed(); 8830 return; 8831 } 8832 8833 if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) 8834 return; 8835 8836 // Do not mark anything as "used" within a dependent context; wait for 8837 // an instantiation. 8838 if (CurContext->isDependentContext()) 8839 return; 8840 8841 switch (ExprEvalContexts.back().Context) { 8842 case Unevaluated: 8843 // We are in an expression that is not potentially evaluated; do nothing. 8844 return; 8845 8846 case PotentiallyEvaluated: 8847 // We are in a potentially-evaluated expression, so this declaration is 8848 // "used"; handle this below. 8849 break; 8850 8851 case PotentiallyPotentiallyEvaluated: 8852 // We are in an expression that may be potentially evaluated; queue this 8853 // declaration reference until we know whether the expression is 8854 // potentially evaluated. 8855 ExprEvalContexts.back().addReferencedDecl(Loc, D); 8856 return; 8857 8858 case PotentiallyEvaluatedIfUsed: 8859 // Referenced declarations will only be used if the construct in the 8860 // containing expression is used. 8861 return; 8862 } 8863 8864 // Note that this declaration has been used. 8865 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { 8866 unsigned TypeQuals; 8867 if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { 8868 if (Constructor->getParent()->hasTrivialConstructor()) 8869 return; 8870 if (!Constructor->isUsed(false)) 8871 DefineImplicitDefaultConstructor(Loc, Constructor); 8872 } else if (Constructor->isImplicit() && 8873 Constructor->isCopyConstructor(TypeQuals)) { 8874 if (!Constructor->isUsed(false)) 8875 DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); 8876 } 8877 8878 MarkVTableUsed(Loc, Constructor->getParent()); 8879 } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { 8880 if (Destructor->isImplicit() && !Destructor->isUsed(false)) 8881 DefineImplicitDestructor(Loc, Destructor); 8882 if (Destructor->isVirtual()) 8883 MarkVTableUsed(Loc, Destructor->getParent()); 8884 } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { 8885 if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && 8886 MethodDecl->getOverloadedOperator() == OO_Equal) { 8887 if (!MethodDecl->isUsed(false)) 8888 DefineImplicitCopyAssignment(Loc, MethodDecl); 8889 } else if (MethodDecl->isVirtual()) 8890 MarkVTableUsed(Loc, MethodDecl->getParent()); 8891 } 8892 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 8893 // Implicit instantiation of function templates and member functions of 8894 // class templates. 8895 if (Function->isImplicitlyInstantiable()) { 8896 bool AlreadyInstantiated = false; 8897 if (FunctionTemplateSpecializationInfo *SpecInfo 8898 = Function->getTemplateSpecializationInfo()) { 8899 if (SpecInfo->getPointOfInstantiation().isInvalid()) 8900 SpecInfo->setPointOfInstantiation(Loc); 8901 else if (SpecInfo->getTemplateSpecializationKind() 8902 == TSK_ImplicitInstantiation) 8903 AlreadyInstantiated = true; 8904 } else if (MemberSpecializationInfo *MSInfo 8905 = Function->getMemberSpecializationInfo()) { 8906 if (MSInfo->getPointOfInstantiation().isInvalid()) 8907 MSInfo->setPointOfInstantiation(Loc); 8908 else if (MSInfo->getTemplateSpecializationKind() 8909 == TSK_ImplicitInstantiation) 8910 AlreadyInstantiated = true; 8911 } 8912 8913 if (!AlreadyInstantiated) { 8914 if (isa<CXXRecordDecl>(Function->getDeclContext()) && 8915 cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) 8916 PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, 8917 Loc)); 8918 else 8919 PendingInstantiations.push_back(std::make_pair(Function, Loc)); 8920 } 8921 } else // Walk redefinitions, as some of them may be instantiable. 8922 for (FunctionDecl::redecl_iterator i(Function->redecls_begin()), 8923 e(Function->redecls_end()); i != e; ++i) { 8924 if (!i->isUsed(false) && i->isImplicitlyInstantiable()) 8925 MarkDeclarationReferenced(Loc, *i); 8926 } 8927 8928 // FIXME: keep track of references to static functions 8929 8930 // Recursive functions should be marked when used from another function. 8931 if (CurContext != Function) 8932 Function->setUsed(true); 8933 8934 return; 8935 } 8936 8937 if (VarDecl *Var = dyn_cast<VarDecl>(D)) { 8938 // Implicit instantiation of static data members of class templates. 8939 if (Var->isStaticDataMember() && 8940 Var->getInstantiatedFromStaticDataMember()) { 8941 MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); 8942 assert(MSInfo && "Missing member specialization information?"); 8943 if (MSInfo->getPointOfInstantiation().isInvalid() && 8944 MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { 8945 MSInfo->setPointOfInstantiation(Loc); 8946 PendingInstantiations.push_back(std::make_pair(Var, Loc)); 8947 } 8948 } 8949 8950 // FIXME: keep track of references to static data? 8951 8952 D->setUsed(true); 8953 return; 8954 } 8955} 8956 8957namespace { 8958 // Mark all of the declarations referenced 8959 // FIXME: Not fully implemented yet! We need to have a better understanding 8960 // of when we're entering 8961 class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { 8962 Sema &S; 8963 SourceLocation Loc; 8964 8965 public: 8966 typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; 8967 8968 MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } 8969 8970 bool TraverseTemplateArgument(const TemplateArgument &Arg); 8971 bool TraverseRecordType(RecordType *T); 8972 }; 8973} 8974 8975bool MarkReferencedDecls::TraverseTemplateArgument( 8976 const TemplateArgument &Arg) { 8977 if (Arg.getKind() == TemplateArgument::Declaration) { 8978 S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); 8979 } 8980 8981 return Inherited::TraverseTemplateArgument(Arg); 8982} 8983 8984bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { 8985 if (ClassTemplateSpecializationDecl *Spec 8986 = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { 8987 const TemplateArgumentList &Args = Spec->getTemplateArgs(); 8988 return TraverseTemplateArguments(Args.data(), Args.size()); 8989 } 8990 8991 return true; 8992} 8993 8994void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { 8995 MarkReferencedDecls Marker(*this, Loc); 8996 Marker.TraverseType(Context.getCanonicalType(T)); 8997} 8998 8999namespace { 9000 /// \brief Helper class that marks all of the declarations referenced by 9001 /// potentially-evaluated subexpressions as "referenced". 9002 class EvaluatedExprMarker : public EvaluatedExprVisitor<EvaluatedExprMarker> { 9003 Sema &S; 9004 9005 public: 9006 typedef EvaluatedExprVisitor<EvaluatedExprMarker> Inherited; 9007 9008 explicit EvaluatedExprMarker(Sema &S) : Inherited(S.Context), S(S) { } 9009 9010 void VisitDeclRefExpr(DeclRefExpr *E) { 9011 S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); 9012 } 9013 9014 void VisitMemberExpr(MemberExpr *E) { 9015 S.MarkDeclarationReferenced(E->getMemberLoc(), E->getMemberDecl()); 9016 Inherited::VisitMemberExpr(E); 9017 } 9018 9019 void VisitCXXNewExpr(CXXNewExpr *E) { 9020 if (E->getConstructor()) 9021 S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); 9022 if (E->getOperatorNew()) 9023 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorNew()); 9024 if (E->getOperatorDelete()) 9025 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); 9026 Inherited::VisitCXXNewExpr(E); 9027 } 9028 9029 void VisitCXXDeleteExpr(CXXDeleteExpr *E) { 9030 if (E->getOperatorDelete()) 9031 S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); 9032 QualType Destroyed = S.Context.getBaseElementType(E->getDestroyedType()); 9033 if (const RecordType *DestroyedRec = Destroyed->getAs<RecordType>()) { 9034 CXXRecordDecl *Record = cast<CXXRecordDecl>(DestroyedRec->getDecl()); 9035 S.MarkDeclarationReferenced(E->getLocStart(), 9036 S.LookupDestructor(Record)); 9037 } 9038 9039 Inherited::VisitCXXDeleteExpr(E); 9040 } 9041 9042 void VisitCXXConstructExpr(CXXConstructExpr *E) { 9043 S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); 9044 Inherited::VisitCXXConstructExpr(E); 9045 } 9046 9047 void VisitBlockDeclRefExpr(BlockDeclRefExpr *E) { 9048 S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); 9049 } 9050 9051 void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) { 9052 Visit(E->getExpr()); 9053 } 9054 }; 9055} 9056 9057/// \brief Mark any declarations that appear within this expression or any 9058/// potentially-evaluated subexpressions as "referenced". 9059void Sema::MarkDeclarationsReferencedInExpr(Expr *E) { 9060 EvaluatedExprMarker(*this).Visit(E); 9061} 9062 9063/// \brief Emit a diagnostic that describes an effect on the run-time behavior 9064/// of the program being compiled. 9065/// 9066/// This routine emits the given diagnostic when the code currently being 9067/// type-checked is "potentially evaluated", meaning that there is a 9068/// possibility that the code will actually be executable. Code in sizeof() 9069/// expressions, code used only during overload resolution, etc., are not 9070/// potentially evaluated. This routine will suppress such diagnostics or, 9071/// in the absolutely nutty case of potentially potentially evaluated 9072/// expressions (C++ typeid), queue the diagnostic to potentially emit it 9073/// later. 9074/// 9075/// This routine should be used for all diagnostics that describe the run-time 9076/// behavior of a program, such as passing a non-POD value through an ellipsis. 9077/// Failure to do so will likely result in spurious diagnostics or failures 9078/// during overload resolution or within sizeof/alignof/typeof/typeid. 9079bool Sema::DiagRuntimeBehavior(SourceLocation Loc, 9080 const PartialDiagnostic &PD) { 9081 switch (ExprEvalContexts.back().Context ) { 9082 case Unevaluated: 9083 // The argument will never be evaluated, so don't complain. 9084 break; 9085 9086 case PotentiallyEvaluated: 9087 case PotentiallyEvaluatedIfUsed: 9088 Diag(Loc, PD); 9089 return true; 9090 9091 case PotentiallyPotentiallyEvaluated: 9092 ExprEvalContexts.back().addDiagnostic(Loc, PD); 9093 break; 9094 } 9095 9096 return false; 9097} 9098 9099bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, 9100 CallExpr *CE, FunctionDecl *FD) { 9101 if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) 9102 return false; 9103 9104 PartialDiagnostic Note = 9105 FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) 9106 << FD->getDeclName() : PDiag(); 9107 SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); 9108 9109 if (RequireCompleteType(Loc, ReturnType, 9110 FD ? 9111 PDiag(diag::err_call_function_incomplete_return) 9112 << CE->getSourceRange() << FD->getDeclName() : 9113 PDiag(diag::err_call_incomplete_return) 9114 << CE->getSourceRange(), 9115 std::make_pair(NoteLoc, Note))) 9116 return true; 9117 9118 return false; 9119} 9120 9121// Diagnose the s/=/==/ and s/\|=/!=/ typos. Note that adding parentheses 9122// will prevent this condition from triggering, which is what we want. 9123void Sema::DiagnoseAssignmentAsCondition(Expr *E) { 9124 SourceLocation Loc; 9125 9126 unsigned diagnostic = diag::warn_condition_is_assignment; 9127 bool IsOrAssign = false; 9128 9129 if (isa<BinaryOperator>(E)) { 9130 BinaryOperator *Op = cast<BinaryOperator>(E); 9131 if (Op->getOpcode() != BO_Assign && Op->getOpcode() != BO_OrAssign) 9132 return; 9133 9134 IsOrAssign = Op->getOpcode() == BO_OrAssign; 9135 9136 // Greylist some idioms by putting them into a warning subcategory. 9137 if (ObjCMessageExpr *ME 9138 = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { 9139 Selector Sel = ME->getSelector(); 9140 9141 // self = [<foo> init...] 9142 if (isSelfExpr(Op->getLHS()) 9143 && Sel.getIdentifierInfoForSlot(0)->getName().startswith("init")) 9144 diagnostic = diag::warn_condition_is_idiomatic_assignment; 9145 9146 // <foo> = [<bar> nextObject] 9147 else if (Sel.isUnarySelector() && 9148 Sel.getIdentifierInfoForSlot(0)->getName() == "nextObject") 9149 diagnostic = diag::warn_condition_is_idiomatic_assignment; 9150 } 9151 9152 Loc = Op->getOperatorLoc(); 9153 } else if (isa<CXXOperatorCallExpr>(E)) { 9154 CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); 9155 if (Op->getOperator() != OO_Equal && Op->getOperator() != OO_PipeEqual) 9156 return; 9157 9158 IsOrAssign = Op->getOperator() == OO_PipeEqual; 9159 Loc = Op->getOperatorLoc(); 9160 } else { 9161 // Not an assignment. 9162 return; 9163 } 9164 9165 SourceLocation Open = E->getSourceRange().getBegin(); 9166 SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); 9167 9168 Diag(Loc, diagnostic) << E->getSourceRange(); 9169 9170 if (IsOrAssign) 9171 Diag(Loc, diag::note_condition_or_assign_to_comparison) 9172 << FixItHint::CreateReplacement(Loc, "!="); 9173 else 9174 Diag(Loc, diag::note_condition_assign_to_comparison) 9175 << FixItHint::CreateReplacement(Loc, "=="); 9176 9177 Diag(Loc, diag::note_condition_assign_silence) 9178 << FixItHint::CreateInsertion(Open, "(") 9179 << FixItHint::CreateInsertion(Close, ")"); 9180} 9181 9182bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) { 9183 DiagnoseAssignmentAsCondition(E); 9184 9185 if (!E->isTypeDependent()) { 9186 if (E->isBoundMemberFunction(Context)) 9187 return Diag(E->getLocStart(), diag::err_invalid_use_of_bound_member_func) 9188 << E->getSourceRange(); 9189 9190 if (getLangOptions().CPlusPlus) 9191 return CheckCXXBooleanCondition(E); // C++ 6.4p4 9192 9193 DefaultFunctionArrayLvalueConversion(E); 9194 9195 QualType T = E->getType(); 9196 if (!T->isScalarType()) // C99 6.8.4.1p1 9197 return Diag(Loc, diag::err_typecheck_statement_requires_scalar) 9198 << T << E->getSourceRange(); 9199 } 9200 9201 return false; 9202} 9203 9204ExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, 9205 Expr *Sub) { 9206 if (!Sub) 9207 return ExprError(); 9208 9209 if (CheckBooleanCondition(Sub, Loc)) 9210 return ExprError(); 9211 9212 return Owned(Sub); 9213} 9214 9215/// Check for operands with placeholder types and complain if found. 9216/// Returns true if there was an error and no recovery was possible. 9217ExprResult Sema::CheckPlaceholderExpr(Expr *E, SourceLocation Loc) { 9218 const BuiltinType *BT = E->getType()->getAs<BuiltinType>(); 9219 if (!BT || !BT->isPlaceholderType()) return Owned(E); 9220 9221 // If this is overload, check for a single overload. 9222 if (BT->getKind() == BuiltinType::Overload) { 9223 if (FunctionDecl *Specialization 9224 = ResolveSingleFunctionTemplateSpecialization(E)) { 9225 // The access doesn't really matter in this case. 9226 DeclAccessPair Found = DeclAccessPair::make(Specialization, 9227 Specialization->getAccess()); 9228 E = FixOverloadedFunctionReference(E, Found, Specialization); 9229 if (!E) return ExprError(); 9230 return Owned(E); 9231 } 9232 9233 Diag(Loc, diag::err_ovl_unresolvable) << E->getSourceRange(); 9234 return ExprError(); 9235 } 9236 9237 // Otherwise it's a use of undeduced auto. 9238 assert(BT->getKind() == BuiltinType::UndeducedAuto); 9239 9240 DeclRefExpr *DRE = cast<DeclRefExpr>(E->IgnoreParens()); 9241 Diag(Loc, diag::err_auto_variable_cannot_appear_in_own_initializer) 9242 << DRE->getDecl() << E->getSourceRange(); 9243 return ExprError(); 9244} 9245