1 //===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 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 statements. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/Sema/SemaInternal.h" 15 #include "clang/Sema/Scope.h" 16 #include "clang/Sema/ScopeInfo.h" 17 #include "clang/Sema/Initialization.h" 18 #include "clang/Sema/Lookup.h" 19 #include "clang/AST/ASTContext.h" 20 #include "clang/AST/CharUnits.h" 21 #include "clang/AST/DeclObjC.h" 22 #include "clang/AST/ExprCXX.h" 23 #include "clang/AST/ExprObjC.h" 24 #include "clang/AST/StmtObjC.h" 25 #include "clang/AST/StmtCXX.h" 26 #include "clang/AST/TypeLoc.h" 27 #include "clang/Lex/Preprocessor.h" 28 #include "clang/Basic/TargetInfo.h" 29 #include "llvm/ADT/ArrayRef.h" 30 #include "llvm/ADT/STLExtras.h" 31 #include "llvm/ADT/SmallVector.h" 32 using namespace clang; 33 using namespace sema; 34 35 StmtResult Sema::ActOnExprStmt(FullExprArg expr) { 36 Expr *E = expr.get(); 37 if (!E) // FIXME: FullExprArg has no error state? 38 return StmtError(); 39 40 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 41 // void expression for its side effects. Conversion to void allows any 42 // operand, even incomplete types. 43 44 // Same thing in for stmt first clause (when expr) and third clause. 45 return Owned(static_cast<Stmt*>(E)); 46 } 47 48 49 StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, 50 bool HasLeadingEmptyMacro) { 51 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); 52 } 53 54 StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, 55 SourceLocation EndLoc) { 56 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 57 58 // If we have an invalid decl, just return an error. 59 if (DG.isNull()) return StmtError(); 60 61 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 62 } 63 64 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { 65 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 66 67 // If we have an invalid decl, just return. 68 if (DG.isNull() || !DG.isSingleDecl()) return; 69 VarDecl *var = cast<VarDecl>(DG.getSingleDecl()); 70 71 // suppress any potential 'unused variable' warning. 72 var->setUsed(); 73 74 // foreach variables are never actually initialized in the way that 75 // the parser came up with. 76 var->setInit(0); 77 78 // In ARC, we don't need to retain the iteration variable of a fast 79 // enumeration loop. Rather than actually trying to catch that 80 // during declaration processing, we remove the consequences here. 81 if (getLangOpts().ObjCAutoRefCount) { 82 QualType type = var->getType(); 83 84 // Only do this if we inferred the lifetime. Inferred lifetime 85 // will show up as a local qualifier because explicit lifetime 86 // should have shown up as an AttributedType instead. 87 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { 88 // Add 'const' and mark the variable as pseudo-strong. 89 var->setType(type.withConst()); 90 var->setARCPseudoStrong(true); 91 } 92 } 93 } 94 95 /// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. 96 /// 97 /// Adding a cast to void (or other expression wrappers) will prevent the 98 /// warning from firing. 99 static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { 100 SourceLocation Loc; 101 bool IsNotEqual, CanAssign; 102 103 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { 104 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) 105 return false; 106 107 Loc = Op->getOperatorLoc(); 108 IsNotEqual = Op->getOpcode() == BO_NE; 109 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); 110 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { 111 if (Op->getOperator() != OO_EqualEqual && 112 Op->getOperator() != OO_ExclaimEqual) 113 return false; 114 115 Loc = Op->getOperatorLoc(); 116 IsNotEqual = Op->getOperator() == OO_ExclaimEqual; 117 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); 118 } else { 119 // Not a typo-prone comparison. 120 return false; 121 } 122 123 // Suppress warnings when the operator, suspicious as it may be, comes from 124 // a macro expansion. 125 if (Loc.isMacroID()) 126 return false; 127 128 S.Diag(Loc, diag::warn_unused_comparison) 129 << (unsigned)IsNotEqual << E->getSourceRange(); 130 131 // If the LHS is a plausible entity to assign to, provide a fixit hint to 132 // correct common typos. 133 if (CanAssign) { 134 if (IsNotEqual) 135 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) 136 << FixItHint::CreateReplacement(Loc, "|="); 137 else 138 S.Diag(Loc, diag::note_equality_comparison_to_assign) 139 << FixItHint::CreateReplacement(Loc, "="); 140 } 141 142 return true; 143 } 144 145 void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 146 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 147 return DiagnoseUnusedExprResult(Label->getSubStmt()); 148 149 const Expr *E = dyn_cast_or_null<Expr>(S); 150 if (!E) 151 return; 152 153 SourceLocation Loc; 154 SourceRange R1, R2; 155 if (SourceMgr.isInSystemMacro(E->getExprLoc()) || 156 !E->isUnusedResultAWarning(Loc, R1, R2, Context)) 157 return; 158 159 // Okay, we have an unused result. Depending on what the base expression is, 160 // we might want to make a more specific diagnostic. Check for one of these 161 // cases now. 162 unsigned DiagID = diag::warn_unused_expr; 163 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 164 E = Temps->getSubExpr(); 165 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 166 E = TempExpr->getSubExpr(); 167 168 if (DiagnoseUnusedComparison(*this, E)) 169 return; 170 171 E = E->IgnoreParenImpCasts(); 172 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 173 if (E->getType()->isVoidType()) 174 return; 175 176 // If the callee has attribute pure, const, or warn_unused_result, warn with 177 // a more specific message to make it clear what is happening. 178 if (const Decl *FD = CE->getCalleeDecl()) { 179 if (FD->getAttr<WarnUnusedResultAttr>()) { 180 Diag(Loc, diag::warn_unused_result) << R1 << R2; 181 return; 182 } 183 if (FD->getAttr<PureAttr>()) { 184 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 185 return; 186 } 187 if (FD->getAttr<ConstAttr>()) { 188 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 189 return; 190 } 191 } 192 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 193 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { 194 Diag(Loc, diag::err_arc_unused_init_message) << R1; 195 return; 196 } 197 const ObjCMethodDecl *MD = ME->getMethodDecl(); 198 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 199 Diag(Loc, diag::warn_unused_result) << R1 << R2; 200 return; 201 } 202 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 203 const Expr *Source = POE->getSyntacticForm(); 204 if (isa<ObjCSubscriptRefExpr>(Source)) 205 DiagID = diag::warn_unused_container_subscript_expr; 206 else 207 DiagID = diag::warn_unused_property_expr; 208 } else if (const CXXFunctionalCastExpr *FC 209 = dyn_cast<CXXFunctionalCastExpr>(E)) { 210 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 211 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 212 return; 213 } 214 // Diagnose "(void*) blah" as a typo for "(void) blah". 215 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 216 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 217 QualType T = TI->getType(); 218 219 // We really do want to use the non-canonical type here. 220 if (T == Context.VoidPtrTy) { 221 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 222 223 Diag(Loc, diag::warn_unused_voidptr) 224 << FixItHint::CreateRemoval(TL.getStarLoc()); 225 return; 226 } 227 } 228 229 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 230 } 231 232 void Sema::ActOnStartOfCompoundStmt() { 233 PushCompoundScope(); 234 } 235 236 void Sema::ActOnFinishOfCompoundStmt() { 237 PopCompoundScope(); 238 } 239 240 sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { 241 return getCurFunction()->CompoundScopes.back(); 242 } 243 244 StmtResult 245 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 246 MultiStmtArg elts, bool isStmtExpr) { 247 unsigned NumElts = elts.size(); 248 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 249 // If we're in C89 mode, check that we don't have any decls after stmts. If 250 // so, emit an extension diagnostic. 251 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { 252 // Note that __extension__ can be around a decl. 253 unsigned i = 0; 254 // Skip over all declarations. 255 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 256 /*empty*/; 257 258 // We found the end of the list or a statement. Scan for another declstmt. 259 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 260 /*empty*/; 261 262 if (i != NumElts) { 263 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 264 Diag(D->getLocation(), diag::ext_mixed_decls_code); 265 } 266 } 267 // Warn about unused expressions in statements. 268 for (unsigned i = 0; i != NumElts; ++i) { 269 // Ignore statements that are last in a statement expression. 270 if (isStmtExpr && i == NumElts - 1) 271 continue; 272 273 DiagnoseUnusedExprResult(Elts[i]); 274 } 275 276 // Check for suspicious empty body (null statement) in `for' and `while' 277 // statements. Don't do anything for template instantiations, this just adds 278 // noise. 279 if (NumElts != 0 && !CurrentInstantiationScope && 280 getCurCompoundScope().HasEmptyLoopBodies) { 281 for (unsigned i = 0; i != NumElts - 1; ++i) 282 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); 283 } 284 285 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 286 } 287 288 StmtResult 289 Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 290 SourceLocation DotDotDotLoc, Expr *RHSVal, 291 SourceLocation ColonLoc) { 292 assert((LHSVal != 0) && "missing expression in case statement"); 293 294 if (getCurFunction()->SwitchStack.empty()) { 295 Diag(CaseLoc, diag::err_case_not_in_switch); 296 return StmtError(); 297 } 298 299 if (!getLangOpts().CPlusPlus0x) { 300 // C99 6.8.4.2p3: The expression shall be an integer constant. 301 // However, GCC allows any evaluatable integer expression. 302 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { 303 LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); 304 if (!LHSVal) 305 return StmtError(); 306 } 307 308 // GCC extension: The expression shall be an integer constant. 309 310 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { 311 RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); 312 // Recover from an error by just forgetting about it. 313 } 314 } 315 316 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 317 ColonLoc); 318 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 319 return Owned(CS); 320 } 321 322 /// ActOnCaseStmtBody - This installs a statement as the body of a case. 323 void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 324 DiagnoseUnusedExprResult(SubStmt); 325 326 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 327 CS->setSubStmt(SubStmt); 328 } 329 330 StmtResult 331 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 332 Stmt *SubStmt, Scope *CurScope) { 333 DiagnoseUnusedExprResult(SubStmt); 334 335 if (getCurFunction()->SwitchStack.empty()) { 336 Diag(DefaultLoc, diag::err_default_not_in_switch); 337 return Owned(SubStmt); 338 } 339 340 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 341 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 342 return Owned(DS); 343 } 344 345 StmtResult 346 Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 347 SourceLocation ColonLoc, Stmt *SubStmt) { 348 // If the label was multiply defined, reject it now. 349 if (TheDecl->getStmt()) { 350 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 351 Diag(TheDecl->getLocation(), diag::note_previous_definition); 352 return Owned(SubStmt); 353 } 354 355 // Otherwise, things are good. Fill in the declaration and return it. 356 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 357 TheDecl->setStmt(LS); 358 if (!TheDecl->isGnuLocal()) 359 TheDecl->setLocation(IdentLoc); 360 return Owned(LS); 361 } 362 363 StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, 364 const AttrVec &Attrs, 365 Stmt *SubStmt) { 366 // Fill in the declaration and return it. Variable length will require to 367 // change this to AttributedStmt::Create(Context, ....); 368 // and probably using ArrayRef 369 AttributedStmt *LS = new (Context) AttributedStmt(AttrLoc, Attrs, SubStmt); 370 return Owned(LS); 371 } 372 373 StmtResult 374 Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 375 Stmt *thenStmt, SourceLocation ElseLoc, 376 Stmt *elseStmt) { 377 ExprResult CondResult(CondVal.release()); 378 379 VarDecl *ConditionVar = 0; 380 if (CondVar) { 381 ConditionVar = cast<VarDecl>(CondVar); 382 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 383 if (CondResult.isInvalid()) 384 return StmtError(); 385 } 386 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 387 if (!ConditionExpr) 388 return StmtError(); 389 390 DiagnoseUnusedExprResult(thenStmt); 391 392 if (!elseStmt) { 393 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, 394 diag::warn_empty_if_body); 395 } 396 397 DiagnoseUnusedExprResult(elseStmt); 398 399 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 400 thenStmt, ElseLoc, elseStmt)); 401 } 402 403 /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 404 /// the specified width and sign. If an overflow occurs, detect it and emit 405 /// the specified diagnostic. 406 void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 407 unsigned NewWidth, bool NewSign, 408 SourceLocation Loc, 409 unsigned DiagID) { 410 // Perform a conversion to the promoted condition type if needed. 411 if (NewWidth > Val.getBitWidth()) { 412 // If this is an extension, just do it. 413 Val = Val.extend(NewWidth); 414 Val.setIsSigned(NewSign); 415 416 // If the input was signed and negative and the output is 417 // unsigned, don't bother to warn: this is implementation-defined 418 // behavior. 419 // FIXME: Introduce a second, default-ignored warning for this case? 420 } else if (NewWidth < Val.getBitWidth()) { 421 // If this is a truncation, check for overflow. 422 llvm::APSInt ConvVal(Val); 423 ConvVal = ConvVal.trunc(NewWidth); 424 ConvVal.setIsSigned(NewSign); 425 ConvVal = ConvVal.extend(Val.getBitWidth()); 426 ConvVal.setIsSigned(Val.isSigned()); 427 if (ConvVal != Val) 428 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 429 430 // Regardless of whether a diagnostic was emitted, really do the 431 // truncation. 432 Val = Val.trunc(NewWidth); 433 Val.setIsSigned(NewSign); 434 } else if (NewSign != Val.isSigned()) { 435 // Convert the sign to match the sign of the condition. This can cause 436 // overflow as well: unsigned(INTMIN) 437 // We don't diagnose this overflow, because it is implementation-defined 438 // behavior. 439 // FIXME: Introduce a second, default-ignored warning for this case? 440 llvm::APSInt OldVal(Val); 441 Val.setIsSigned(NewSign); 442 } 443 } 444 445 namespace { 446 struct CaseCompareFunctor { 447 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 448 const llvm::APSInt &RHS) { 449 return LHS.first < RHS; 450 } 451 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 452 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 453 return LHS.first < RHS.first; 454 } 455 bool operator()(const llvm::APSInt &LHS, 456 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 457 return LHS < RHS.first; 458 } 459 }; 460 } 461 462 /// CmpCaseVals - Comparison predicate for sorting case values. 463 /// 464 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 465 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 466 if (lhs.first < rhs.first) 467 return true; 468 469 if (lhs.first == rhs.first && 470 lhs.second->getCaseLoc().getRawEncoding() 471 < rhs.second->getCaseLoc().getRawEncoding()) 472 return true; 473 return false; 474 } 475 476 /// CmpEnumVals - Comparison predicate for sorting enumeration values. 477 /// 478 static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 479 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 480 { 481 return lhs.first < rhs.first; 482 } 483 484 /// EqEnumVals - Comparison preficate for uniqing enumeration values. 485 /// 486 static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 487 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 488 { 489 return lhs.first == rhs.first; 490 } 491 492 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 493 /// potentially integral-promoted expression @p expr. 494 static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 495 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 496 expr = cleanups->getSubExpr(); 497 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 498 if (impcast->getCastKind() != CK_IntegralCast) break; 499 expr = impcast->getSubExpr(); 500 } 501 return expr->getType(); 502 } 503 504 StmtResult 505 Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 506 Decl *CondVar) { 507 ExprResult CondResult; 508 509 VarDecl *ConditionVar = 0; 510 if (CondVar) { 511 ConditionVar = cast<VarDecl>(CondVar); 512 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 513 if (CondResult.isInvalid()) 514 return StmtError(); 515 516 Cond = CondResult.release(); 517 } 518 519 if (!Cond) 520 return StmtError(); 521 522 CondResult 523 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, 524 PDiag(diag::err_typecheck_statement_requires_integer), 525 PDiag(diag::err_switch_incomplete_class_type) 526 << Cond->getSourceRange(), 527 PDiag(diag::err_switch_explicit_conversion), 528 PDiag(diag::note_switch_conversion), 529 PDiag(diag::err_switch_multiple_conversions), 530 PDiag(diag::note_switch_conversion), 531 PDiag(0), 532 /*AllowScopedEnumerations*/ true); 533 if (CondResult.isInvalid()) return StmtError(); 534 Cond = CondResult.take(); 535 536 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 537 CondResult = UsualUnaryConversions(Cond); 538 if (CondResult.isInvalid()) return StmtError(); 539 Cond = CondResult.take(); 540 541 if (!CondVar) { 542 CheckImplicitConversions(Cond, SwitchLoc); 543 CondResult = MaybeCreateExprWithCleanups(Cond); 544 if (CondResult.isInvalid()) 545 return StmtError(); 546 Cond = CondResult.take(); 547 } 548 549 getCurFunction()->setHasBranchIntoScope(); 550 551 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 552 getCurFunction()->SwitchStack.push_back(SS); 553 return Owned(SS); 554 } 555 556 static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 557 if (Val.getBitWidth() < BitWidth) 558 Val = Val.extend(BitWidth); 559 else if (Val.getBitWidth() > BitWidth) 560 Val = Val.trunc(BitWidth); 561 Val.setIsSigned(IsSigned); 562 } 563 564 StmtResult 565 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 566 Stmt *BodyStmt) { 567 SwitchStmt *SS = cast<SwitchStmt>(Switch); 568 assert(SS == getCurFunction()->SwitchStack.back() && 569 "switch stack missing push/pop!"); 570 571 SS->setBody(BodyStmt, SwitchLoc); 572 getCurFunction()->SwitchStack.pop_back(); 573 574 Expr *CondExpr = SS->getCond(); 575 if (!CondExpr) return StmtError(); 576 577 QualType CondType = CondExpr->getType(); 578 579 Expr *CondExprBeforePromotion = CondExpr; 580 QualType CondTypeBeforePromotion = 581 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 582 583 // C++ 6.4.2.p2: 584 // Integral promotions are performed (on the switch condition). 585 // 586 // A case value unrepresentable by the original switch condition 587 // type (before the promotion) doesn't make sense, even when it can 588 // be represented by the promoted type. Therefore we need to find 589 // the pre-promotion type of the switch condition. 590 if (!CondExpr->isTypeDependent()) { 591 // We have already converted the expression to an integral or enumeration 592 // type, when we started the switch statement. If we don't have an 593 // appropriate type now, just return an error. 594 if (!CondType->isIntegralOrEnumerationType()) 595 return StmtError(); 596 597 if (CondExpr->isKnownToHaveBooleanValue()) { 598 // switch(bool_expr) {...} is often a programmer error, e.g. 599 // switch(n && mask) { ... } // Doh - should be "n & mask". 600 // One can always use an if statement instead of switch(bool_expr). 601 Diag(SwitchLoc, diag::warn_bool_switch_condition) 602 << CondExpr->getSourceRange(); 603 } 604 } 605 606 // Get the bitwidth of the switched-on value before promotions. We must 607 // convert the integer case values to this width before comparison. 608 bool HasDependentValue 609 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 610 unsigned CondWidth 611 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 612 bool CondIsSigned 613 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 614 615 // Accumulate all of the case values in a vector so that we can sort them 616 // and detect duplicates. This vector contains the APInt for the case after 617 // it has been converted to the condition type. 618 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 619 CaseValsTy CaseVals; 620 621 // Keep track of any GNU case ranges we see. The APSInt is the low value. 622 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 623 CaseRangesTy CaseRanges; 624 625 DefaultStmt *TheDefaultStmt = 0; 626 627 bool CaseListIsErroneous = false; 628 629 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 630 SC = SC->getNextSwitchCase()) { 631 632 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 633 if (TheDefaultStmt) { 634 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 635 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 636 637 // FIXME: Remove the default statement from the switch block so that 638 // we'll return a valid AST. This requires recursing down the AST and 639 // finding it, not something we are set up to do right now. For now, 640 // just lop the entire switch stmt out of the AST. 641 CaseListIsErroneous = true; 642 } 643 TheDefaultStmt = DS; 644 645 } else { 646 CaseStmt *CS = cast<CaseStmt>(SC); 647 648 Expr *Lo = CS->getLHS(); 649 650 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 651 HasDependentValue = true; 652 break; 653 } 654 655 llvm::APSInt LoVal; 656 657 if (getLangOpts().CPlusPlus0x) { 658 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 659 // constant expression of the promoted type of the switch condition. 660 ExprResult ConvLo = 661 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); 662 if (ConvLo.isInvalid()) { 663 CaseListIsErroneous = true; 664 continue; 665 } 666 Lo = ConvLo.take(); 667 } else { 668 // We already verified that the expression has a i-c-e value (C99 669 // 6.8.4.2p3) - get that value now. 670 LoVal = Lo->EvaluateKnownConstInt(Context); 671 672 // If the LHS is not the same type as the condition, insert an implicit 673 // cast. 674 Lo = DefaultLvalueConversion(Lo).take(); 675 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 676 } 677 678 // Convert the value to the same width/sign as the condition had prior to 679 // integral promotions. 680 // 681 // FIXME: This causes us to reject valid code: 682 // switch ((char)c) { case 256: case 0: return 0; } 683 // Here we claim there is a duplicated condition value, but there is not. 684 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 685 Lo->getLocStart(), 686 diag::warn_case_value_overflow); 687 688 CS->setLHS(Lo); 689 690 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 691 if (CS->getRHS()) { 692 if (CS->getRHS()->isTypeDependent() || 693 CS->getRHS()->isValueDependent()) { 694 HasDependentValue = true; 695 break; 696 } 697 CaseRanges.push_back(std::make_pair(LoVal, CS)); 698 } else 699 CaseVals.push_back(std::make_pair(LoVal, CS)); 700 } 701 } 702 703 if (!HasDependentValue) { 704 // If we don't have a default statement, check whether the 705 // condition is constant. 706 llvm::APSInt ConstantCondValue; 707 bool HasConstantCond = false; 708 if (!HasDependentValue && !TheDefaultStmt) { 709 HasConstantCond 710 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, 711 Expr::SE_AllowSideEffects); 712 assert(!HasConstantCond || 713 (ConstantCondValue.getBitWidth() == CondWidth && 714 ConstantCondValue.isSigned() == CondIsSigned)); 715 } 716 bool ShouldCheckConstantCond = HasConstantCond; 717 718 // Sort all the scalar case values so we can easily detect duplicates. 719 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 720 721 if (!CaseVals.empty()) { 722 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 723 if (ShouldCheckConstantCond && 724 CaseVals[i].first == ConstantCondValue) 725 ShouldCheckConstantCond = false; 726 727 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 728 // If we have a duplicate, report it. 729 Diag(CaseVals[i].second->getLHS()->getLocStart(), 730 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 731 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 732 diag::note_duplicate_case_prev); 733 // FIXME: We really want to remove the bogus case stmt from the 734 // substmt, but we have no way to do this right now. 735 CaseListIsErroneous = true; 736 } 737 } 738 } 739 740 // Detect duplicate case ranges, which usually don't exist at all in 741 // the first place. 742 if (!CaseRanges.empty()) { 743 // Sort all the case ranges by their low value so we can easily detect 744 // overlaps between ranges. 745 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 746 747 // Scan the ranges, computing the high values and removing empty ranges. 748 std::vector<llvm::APSInt> HiVals; 749 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 750 llvm::APSInt &LoVal = CaseRanges[i].first; 751 CaseStmt *CR = CaseRanges[i].second; 752 Expr *Hi = CR->getRHS(); 753 llvm::APSInt HiVal; 754 755 if (getLangOpts().CPlusPlus0x) { 756 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 757 // constant expression of the promoted type of the switch condition. 758 ExprResult ConvHi = 759 CheckConvertedConstantExpression(Hi, CondType, HiVal, 760 CCEK_CaseValue); 761 if (ConvHi.isInvalid()) { 762 CaseListIsErroneous = true; 763 continue; 764 } 765 Hi = ConvHi.take(); 766 } else { 767 HiVal = Hi->EvaluateKnownConstInt(Context); 768 769 // If the RHS is not the same type as the condition, insert an 770 // implicit cast. 771 Hi = DefaultLvalueConversion(Hi).take(); 772 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 773 } 774 775 // Convert the value to the same width/sign as the condition. 776 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 777 Hi->getLocStart(), 778 diag::warn_case_value_overflow); 779 780 CR->setRHS(Hi); 781 782 // If the low value is bigger than the high value, the case is empty. 783 if (LoVal > HiVal) { 784 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 785 << SourceRange(CR->getLHS()->getLocStart(), 786 Hi->getLocEnd()); 787 CaseRanges.erase(CaseRanges.begin()+i); 788 --i, --e; 789 continue; 790 } 791 792 if (ShouldCheckConstantCond && 793 LoVal <= ConstantCondValue && 794 ConstantCondValue <= HiVal) 795 ShouldCheckConstantCond = false; 796 797 HiVals.push_back(HiVal); 798 } 799 800 // Rescan the ranges, looking for overlap with singleton values and other 801 // ranges. Since the range list is sorted, we only need to compare case 802 // ranges with their neighbors. 803 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 804 llvm::APSInt &CRLo = CaseRanges[i].first; 805 llvm::APSInt &CRHi = HiVals[i]; 806 CaseStmt *CR = CaseRanges[i].second; 807 808 // Check to see whether the case range overlaps with any 809 // singleton cases. 810 CaseStmt *OverlapStmt = 0; 811 llvm::APSInt OverlapVal(32); 812 813 // Find the smallest value >= the lower bound. If I is in the 814 // case range, then we have overlap. 815 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 816 CaseVals.end(), CRLo, 817 CaseCompareFunctor()); 818 if (I != CaseVals.end() && I->first < CRHi) { 819 OverlapVal = I->first; // Found overlap with scalar. 820 OverlapStmt = I->second; 821 } 822 823 // Find the smallest value bigger than the upper bound. 824 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 825 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 826 OverlapVal = (I-1)->first; // Found overlap with scalar. 827 OverlapStmt = (I-1)->second; 828 } 829 830 // Check to see if this case stmt overlaps with the subsequent 831 // case range. 832 if (i && CRLo <= HiVals[i-1]) { 833 OverlapVal = HiVals[i-1]; // Found overlap with range. 834 OverlapStmt = CaseRanges[i-1].second; 835 } 836 837 if (OverlapStmt) { 838 // If we have a duplicate, report it. 839 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 840 << OverlapVal.toString(10); 841 Diag(OverlapStmt->getLHS()->getLocStart(), 842 diag::note_duplicate_case_prev); 843 // FIXME: We really want to remove the bogus case stmt from the 844 // substmt, but we have no way to do this right now. 845 CaseListIsErroneous = true; 846 } 847 } 848 } 849 850 // Complain if we have a constant condition and we didn't find a match. 851 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 852 // TODO: it would be nice if we printed enums as enums, chars as 853 // chars, etc. 854 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 855 << ConstantCondValue.toString(10) 856 << CondExpr->getSourceRange(); 857 } 858 859 // Check to see if switch is over an Enum and handles all of its 860 // values. We only issue a warning if there is not 'default:', but 861 // we still do the analysis to preserve this information in the AST 862 // (which can be used by flow-based analyes). 863 // 864 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 865 866 // If switch has default case, then ignore it. 867 if (!CaseListIsErroneous && !HasConstantCond && ET) { 868 const EnumDecl *ED = ET->getDecl(); 869 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 870 EnumValsTy; 871 EnumValsTy EnumVals; 872 873 // Gather all enum values, set their type and sort them, 874 // allowing easier comparison with CaseVals. 875 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 876 EDI != ED->enumerator_end(); ++EDI) { 877 llvm::APSInt Val = EDI->getInitVal(); 878 AdjustAPSInt(Val, CondWidth, CondIsSigned); 879 EnumVals.push_back(std::make_pair(Val, *EDI)); 880 } 881 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 882 EnumValsTy::iterator EIend = 883 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 884 885 // See which case values aren't in enum. 886 EnumValsTy::const_iterator EI = EnumVals.begin(); 887 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 888 CI != CaseVals.end(); CI++) { 889 while (EI != EIend && EI->first < CI->first) 890 EI++; 891 if (EI == EIend || EI->first > CI->first) 892 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 893 << CondTypeBeforePromotion; 894 } 895 // See which of case ranges aren't in enum 896 EI = EnumVals.begin(); 897 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 898 RI != CaseRanges.end() && EI != EIend; RI++) { 899 while (EI != EIend && EI->first < RI->first) 900 EI++; 901 902 if (EI == EIend || EI->first != RI->first) { 903 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 904 << CondTypeBeforePromotion; 905 } 906 907 llvm::APSInt Hi = 908 RI->second->getRHS()->EvaluateKnownConstInt(Context); 909 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 910 while (EI != EIend && EI->first < Hi) 911 EI++; 912 if (EI == EIend || EI->first != Hi) 913 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 914 << CondTypeBeforePromotion; 915 } 916 917 // Check which enum vals aren't in switch 918 CaseValsTy::const_iterator CI = CaseVals.begin(); 919 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 920 bool hasCasesNotInSwitch = false; 921 922 SmallVector<DeclarationName,8> UnhandledNames; 923 924 for (EI = EnumVals.begin(); EI != EIend; EI++){ 925 // Drop unneeded case values 926 llvm::APSInt CIVal; 927 while (CI != CaseVals.end() && CI->first < EI->first) 928 CI++; 929 930 if (CI != CaseVals.end() && CI->first == EI->first) 931 continue; 932 933 // Drop unneeded case ranges 934 for (; RI != CaseRanges.end(); RI++) { 935 llvm::APSInt Hi = 936 RI->second->getRHS()->EvaluateKnownConstInt(Context); 937 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 938 if (EI->first <= Hi) 939 break; 940 } 941 942 if (RI == CaseRanges.end() || EI->first < RI->first) { 943 hasCasesNotInSwitch = true; 944 UnhandledNames.push_back(EI->second->getDeclName()); 945 } 946 } 947 948 if (TheDefaultStmt && UnhandledNames.empty()) 949 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); 950 951 // Produce a nice diagnostic if multiple values aren't handled. 952 switch (UnhandledNames.size()) { 953 case 0: break; 954 case 1: 955 Diag(CondExpr->getExprLoc(), TheDefaultStmt 956 ? diag::warn_def_missing_case1 : diag::warn_missing_case1) 957 << UnhandledNames[0]; 958 break; 959 case 2: 960 Diag(CondExpr->getExprLoc(), TheDefaultStmt 961 ? diag::warn_def_missing_case2 : diag::warn_missing_case2) 962 << UnhandledNames[0] << UnhandledNames[1]; 963 break; 964 case 3: 965 Diag(CondExpr->getExprLoc(), TheDefaultStmt 966 ? diag::warn_def_missing_case3 : diag::warn_missing_case3) 967 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 968 break; 969 default: 970 Diag(CondExpr->getExprLoc(), TheDefaultStmt 971 ? diag::warn_def_missing_cases : diag::warn_missing_cases) 972 << (unsigned)UnhandledNames.size() 973 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 974 break; 975 } 976 977 if (!hasCasesNotInSwitch) 978 SS->setAllEnumCasesCovered(); 979 } 980 } 981 982 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, 983 diag::warn_empty_switch_body); 984 985 // FIXME: If the case list was broken is some way, we don't have a good system 986 // to patch it up. Instead, just return the whole substmt as broken. 987 if (CaseListIsErroneous) 988 return StmtError(); 989 990 return Owned(SS); 991 } 992 993 StmtResult 994 Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 995 Decl *CondVar, Stmt *Body) { 996 ExprResult CondResult(Cond.release()); 997 998 VarDecl *ConditionVar = 0; 999 if (CondVar) { 1000 ConditionVar = cast<VarDecl>(CondVar); 1001 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 1002 if (CondResult.isInvalid()) 1003 return StmtError(); 1004 } 1005 Expr *ConditionExpr = CondResult.take(); 1006 if (!ConditionExpr) 1007 return StmtError(); 1008 1009 DiagnoseUnusedExprResult(Body); 1010 1011 if (isa<NullStmt>(Body)) 1012 getCurCompoundScope().setHasEmptyLoopBodies(); 1013 1014 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 1015 Body, WhileLoc)); 1016 } 1017 1018 StmtResult 1019 Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 1020 SourceLocation WhileLoc, SourceLocation CondLParen, 1021 Expr *Cond, SourceLocation CondRParen) { 1022 assert(Cond && "ActOnDoStmt(): missing expression"); 1023 1024 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 1025 if (CondResult.isInvalid() || CondResult.isInvalid()) 1026 return StmtError(); 1027 Cond = CondResult.take(); 1028 1029 CheckImplicitConversions(Cond, DoLoc); 1030 CondResult = MaybeCreateExprWithCleanups(Cond); 1031 if (CondResult.isInvalid()) 1032 return StmtError(); 1033 Cond = CondResult.take(); 1034 1035 DiagnoseUnusedExprResult(Body); 1036 1037 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 1038 } 1039 1040 StmtResult 1041 Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1042 Stmt *First, FullExprArg second, Decl *secondVar, 1043 FullExprArg third, 1044 SourceLocation RParenLoc, Stmt *Body) { 1045 if (!getLangOpts().CPlusPlus) { 1046 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 1047 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1048 // declare identifiers for objects having storage class 'auto' or 1049 // 'register'. 1050 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 1051 DI!=DE; ++DI) { 1052 VarDecl *VD = dyn_cast<VarDecl>(*DI); 1053 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 1054 VD = 0; 1055 if (VD == 0) 1056 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 1057 // FIXME: mark decl erroneous! 1058 } 1059 } 1060 } 1061 1062 ExprResult SecondResult(second.release()); 1063 VarDecl *ConditionVar = 0; 1064 if (secondVar) { 1065 ConditionVar = cast<VarDecl>(secondVar); 1066 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 1067 if (SecondResult.isInvalid()) 1068 return StmtError(); 1069 } 1070 1071 Expr *Third = third.release().takeAs<Expr>(); 1072 1073 DiagnoseUnusedExprResult(First); 1074 DiagnoseUnusedExprResult(Third); 1075 DiagnoseUnusedExprResult(Body); 1076 1077 if (isa<NullStmt>(Body)) 1078 getCurCompoundScope().setHasEmptyLoopBodies(); 1079 1080 return Owned(new (Context) ForStmt(Context, First, 1081 SecondResult.take(), ConditionVar, 1082 Third, Body, ForLoc, LParenLoc, 1083 RParenLoc)); 1084 } 1085 1086 /// In an Objective C collection iteration statement: 1087 /// for (x in y) 1088 /// x can be an arbitrary l-value expression. Bind it up as a 1089 /// full-expression. 1090 StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1091 // Reduce placeholder expressions here. Note that this rejects the 1092 // use of pseudo-object l-values in this position. 1093 ExprResult result = CheckPlaceholderExpr(E); 1094 if (result.isInvalid()) return StmtError(); 1095 E = result.take(); 1096 1097 CheckImplicitConversions(E); 1098 1099 result = MaybeCreateExprWithCleanups(E); 1100 if (result.isInvalid()) return StmtError(); 1101 1102 return Owned(static_cast<Stmt*>(result.take())); 1103 } 1104 1105 ExprResult 1106 Sema::ActOnObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1107 assert(collection); 1108 1109 // Bail out early if we've got a type-dependent expression. 1110 if (collection->isTypeDependent()) return Owned(collection); 1111 1112 // Perform normal l-value conversion. 1113 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1114 if (result.isInvalid()) 1115 return ExprError(); 1116 collection = result.take(); 1117 1118 // The operand needs to have object-pointer type. 1119 // TODO: should we do a contextual conversion? 1120 const ObjCObjectPointerType *pointerType = 1121 collection->getType()->getAs<ObjCObjectPointerType>(); 1122 if (!pointerType) 1123 return Diag(forLoc, diag::err_collection_expr_type) 1124 << collection->getType() << collection->getSourceRange(); 1125 1126 // Check that the operand provides 1127 // - countByEnumeratingWithState:objects:count: 1128 const ObjCObjectType *objectType = pointerType->getObjectType(); 1129 ObjCInterfaceDecl *iface = objectType->getInterface(); 1130 1131 // If we have a forward-declared type, we can't do this check. 1132 // Under ARC, it is an error not to have a forward-declared class. 1133 if (iface && 1134 RequireCompleteType(forLoc, QualType(objectType, 0), 1135 getLangOpts().ObjCAutoRefCount 1136 ? PDiag(diag::err_arc_collection_forward) 1137 << collection->getSourceRange() 1138 : PDiag(0))) { 1139 // Otherwise, if we have any useful type information, check that 1140 // the type declares the appropriate method. 1141 } else if (iface || !objectType->qual_empty()) { 1142 IdentifierInfo *selectorIdents[] = { 1143 &Context.Idents.get("countByEnumeratingWithState"), 1144 &Context.Idents.get("objects"), 1145 &Context.Idents.get("count") 1146 }; 1147 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1148 1149 ObjCMethodDecl *method = 0; 1150 1151 // If there's an interface, look in both the public and private APIs. 1152 if (iface) { 1153 method = iface->lookupInstanceMethod(selector); 1154 if (!method) method = LookupPrivateInstanceMethod(selector, iface); 1155 } 1156 1157 // Also check protocol qualifiers. 1158 if (!method) 1159 method = LookupMethodInQualifiedType(selector, pointerType, 1160 /*instance*/ true); 1161 1162 // If we didn't find it anywhere, give up. 1163 if (!method) { 1164 Diag(forLoc, diag::warn_collection_expr_type) 1165 << collection->getType() << selector << collection->getSourceRange(); 1166 } 1167 1168 // TODO: check for an incompatible signature? 1169 } 1170 1171 // Wrap up any cleanups in the expression. 1172 return Owned(MaybeCreateExprWithCleanups(collection)); 1173 } 1174 1175 StmtResult 1176 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1177 SourceLocation LParenLoc, 1178 Stmt *First, Expr *Second, 1179 SourceLocation RParenLoc, Stmt *Body) { 1180 if (First) { 1181 QualType FirstType; 1182 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1183 if (!DS->isSingleDecl()) 1184 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1185 diag::err_toomany_element_decls)); 1186 1187 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1188 FirstType = D->getType(); 1189 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1190 // declare identifiers for objects having storage class 'auto' or 1191 // 'register'. 1192 if (!D->hasLocalStorage()) 1193 return StmtError(Diag(D->getLocation(), 1194 diag::err_non_variable_decl_in_for)); 1195 } else { 1196 Expr *FirstE = cast<Expr>(First); 1197 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1198 return StmtError(Diag(First->getLocStart(), 1199 diag::err_selector_element_not_lvalue) 1200 << First->getSourceRange()); 1201 1202 FirstType = static_cast<Expr*>(First)->getType(); 1203 } 1204 if (!FirstType->isDependentType() && 1205 !FirstType->isObjCObjectPointerType() && 1206 !FirstType->isBlockPointerType()) 1207 Diag(ForLoc, diag::err_selector_element_type) 1208 << FirstType << First->getSourceRange(); 1209 } 1210 1211 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 1212 ForLoc, RParenLoc)); 1213 } 1214 1215 namespace { 1216 1217 enum BeginEndFunction { 1218 BEF_begin, 1219 BEF_end 1220 }; 1221 1222 /// Build a variable declaration for a for-range statement. 1223 static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1224 QualType Type, const char *Name) { 1225 DeclContext *DC = SemaRef.CurContext; 1226 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1227 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1228 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1229 TInfo, SC_Auto, SC_None); 1230 Decl->setImplicit(); 1231 return Decl; 1232 } 1233 1234 /// Finish building a variable declaration for a for-range statement. 1235 /// \return true if an error occurs. 1236 static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1237 SourceLocation Loc, int diag) { 1238 // Deduce the type for the iterator variable now rather than leaving it to 1239 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1240 TypeSourceInfo *InitTSI = 0; 1241 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || 1242 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) == 1243 Sema::DAR_Failed) 1244 SemaRef.Diag(Loc, diag) << Init->getType(); 1245 if (!InitTSI) { 1246 Decl->setInvalidDecl(); 1247 return true; 1248 } 1249 Decl->setTypeSourceInfo(InitTSI); 1250 Decl->setType(InitTSI->getType()); 1251 1252 // In ARC, infer lifetime. 1253 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1254 // we're doing the equivalent of fast iteration. 1255 if (SemaRef.getLangOpts().ObjCAutoRefCount && 1256 SemaRef.inferObjCARCLifetime(Decl)) 1257 Decl->setInvalidDecl(); 1258 1259 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1260 /*TypeMayContainAuto=*/false); 1261 SemaRef.FinalizeDeclaration(Decl); 1262 SemaRef.CurContext->addHiddenDecl(Decl); 1263 return false; 1264 } 1265 1266 /// Produce a note indicating which begin/end function was implicitly called 1267 /// by a C++0x for-range statement. This is often not obvious from the code, 1268 /// nor from the diagnostics produced when analysing the implicit expressions 1269 /// required in a for-range statement. 1270 void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1271 BeginEndFunction BEF) { 1272 CallExpr *CE = dyn_cast<CallExpr>(E); 1273 if (!CE) 1274 return; 1275 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1276 if (!D) 1277 return; 1278 SourceLocation Loc = D->getLocation(); 1279 1280 std::string Description; 1281 bool IsTemplate = false; 1282 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1283 Description = SemaRef.getTemplateArgumentBindingsText( 1284 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1285 IsTemplate = true; 1286 } 1287 1288 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1289 << BEF << IsTemplate << Description << E->getType(); 1290 } 1291 1292 /// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1293 /// given LookupResult is non-empty, it is assumed to describe a member which 1294 /// will be invoked. Otherwise, the function will be found via argument 1295 /// dependent lookup. 1296 static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1297 SourceLocation Loc, 1298 VarDecl *Decl, 1299 BeginEndFunction BEF, 1300 const DeclarationNameInfo &NameInfo, 1301 LookupResult &MemberLookup, 1302 Expr *Range) { 1303 ExprResult CallExpr; 1304 if (!MemberLookup.empty()) { 1305 ExprResult MemberRef = 1306 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1307 /*IsPtr=*/false, CXXScopeSpec(), 1308 /*TemplateKWLoc=*/SourceLocation(), 1309 /*FirstQualifierInScope=*/0, 1310 MemberLookup, 1311 /*TemplateArgs=*/0); 1312 if (MemberRef.isInvalid()) 1313 return ExprError(); 1314 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1315 Loc, 0); 1316 if (CallExpr.isInvalid()) 1317 return ExprError(); 1318 } else { 1319 UnresolvedSet<0> FoundNames; 1320 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1321 // std is an associated namespace. 1322 UnresolvedLookupExpr *Fn = 1323 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1324 NestedNameSpecifierLoc(), NameInfo, 1325 /*NeedsADL=*/true, /*Overloaded=*/false, 1326 FoundNames.begin(), FoundNames.end(), 1327 /*LookInStdNamespace=*/true); 1328 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1329 0, /*AllowTypoCorrection=*/false); 1330 if (CallExpr.isInvalid()) { 1331 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1332 << Range->getType(); 1333 return ExprError(); 1334 } 1335 } 1336 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1337 diag::err_for_range_iter_deduction_failure)) { 1338 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1339 return ExprError(); 1340 } 1341 return CallExpr; 1342 } 1343 1344 } 1345 1346 /// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1347 /// 1348 /// C++0x [stmt.ranged]: 1349 /// A range-based for statement is equivalent to 1350 /// 1351 /// { 1352 /// auto && __range = range-init; 1353 /// for ( auto __begin = begin-expr, 1354 /// __end = end-expr; 1355 /// __begin != __end; 1356 /// ++__begin ) { 1357 /// for-range-declaration = *__begin; 1358 /// statement 1359 /// } 1360 /// } 1361 /// 1362 /// The body of the loop is not available yet, since it cannot be analysed until 1363 /// we have determined the type of the for-range-declaration. 1364 StmtResult 1365 Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1366 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1367 SourceLocation RParenLoc) { 1368 if (!First || !Range) 1369 return StmtError(); 1370 1371 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1372 assert(DS && "first part of for range not a decl stmt"); 1373 1374 if (!DS->isSingleDecl()) { 1375 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1376 return StmtError(); 1377 } 1378 if (DS->getSingleDecl()->isInvalidDecl()) 1379 return StmtError(); 1380 1381 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1382 return StmtError(); 1383 1384 // Build auto && __range = range-init 1385 SourceLocation RangeLoc = Range->getLocStart(); 1386 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1387 Context.getAutoRRefDeductType(), 1388 "__range"); 1389 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1390 diag::err_for_range_deduction_failure)) 1391 return StmtError(); 1392 1393 // Claim the type doesn't contain auto: we've already done the checking. 1394 DeclGroupPtrTy RangeGroup = 1395 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1396 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1397 if (RangeDecl.isInvalid()) 1398 return StmtError(); 1399 1400 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1401 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1402 RParenLoc); 1403 } 1404 1405 /// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1406 StmtResult 1407 Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1408 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1409 Expr *Inc, Stmt *LoopVarDecl, 1410 SourceLocation RParenLoc) { 1411 Scope *S = getCurScope(); 1412 1413 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1414 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1415 QualType RangeVarType = RangeVar->getType(); 1416 1417 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1418 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1419 1420 StmtResult BeginEndDecl = BeginEnd; 1421 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1422 1423 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1424 SourceLocation RangeLoc = RangeVar->getLocation(); 1425 1426 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); 1427 1428 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1429 VK_LValue, ColonLoc); 1430 if (BeginRangeRef.isInvalid()) 1431 return StmtError(); 1432 1433 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1434 VK_LValue, ColonLoc); 1435 if (EndRangeRef.isInvalid()) 1436 return StmtError(); 1437 1438 QualType AutoType = Context.getAutoDeductType(); 1439 Expr *Range = RangeVar->getInit(); 1440 if (!Range) 1441 return StmtError(); 1442 QualType RangeType = Range->getType(); 1443 1444 if (RequireCompleteType(RangeLoc, RangeType, 1445 PDiag(diag::err_for_range_incomplete_type))) 1446 return StmtError(); 1447 1448 // Build auto __begin = begin-expr, __end = end-expr. 1449 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1450 "__begin"); 1451 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1452 "__end"); 1453 1454 // Build begin-expr and end-expr and attach to __begin and __end variables. 1455 ExprResult BeginExpr, EndExpr; 1456 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1457 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1458 // __range + __bound, respectively, where __bound is the array bound. If 1459 // _RangeT is an array of unknown size or an array of incomplete type, 1460 // the program is ill-formed; 1461 1462 // begin-expr is __range. 1463 BeginExpr = BeginRangeRef; 1464 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, 1465 diag::err_for_range_iter_deduction_failure)) { 1466 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1467 return StmtError(); 1468 } 1469 1470 // Find the array bound. 1471 ExprResult BoundExpr; 1472 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1473 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1474 Context.getPointerDiffType(), 1475 RangeLoc)); 1476 else if (const VariableArrayType *VAT = 1477 dyn_cast<VariableArrayType>(UnqAT)) 1478 BoundExpr = VAT->getSizeExpr(); 1479 else { 1480 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1481 // UnqAT is not incomplete and Range is not type-dependent. 1482 llvm_unreachable("Unexpected array type in for-range"); 1483 } 1484 1485 // end-expr is __range + __bound. 1486 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), 1487 BoundExpr.get()); 1488 if (EndExpr.isInvalid()) 1489 return StmtError(); 1490 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1491 diag::err_for_range_iter_deduction_failure)) { 1492 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1493 return StmtError(); 1494 } 1495 } else { 1496 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1497 ColonLoc); 1498 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1499 ColonLoc); 1500 1501 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1502 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1503 1504 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1505 // - if _RangeT is a class type, the unqualified-ids begin and end are 1506 // looked up in the scope of class _RangeT as if by class member access 1507 // lookup (3.4.5), and if either (or both) finds at least one 1508 // declaration, begin-expr and end-expr are __range.begin() and 1509 // __range.end(), respectively; 1510 LookupQualifiedName(BeginMemberLookup, D); 1511 LookupQualifiedName(EndMemberLookup, D); 1512 1513 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1514 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1515 << RangeType << BeginMemberLookup.empty(); 1516 return StmtError(); 1517 } 1518 } else { 1519 // - otherwise, begin-expr and end-expr are begin(__range) and 1520 // end(__range), respectively, where begin and end are looked up with 1521 // argument-dependent lookup (3.4.2). For the purposes of this name 1522 // lookup, namespace std is an associated namespace. 1523 } 1524 1525 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1526 BEF_begin, BeginNameInfo, 1527 BeginMemberLookup, 1528 BeginRangeRef.get()); 1529 if (BeginExpr.isInvalid()) 1530 return StmtError(); 1531 1532 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1533 BEF_end, EndNameInfo, 1534 EndMemberLookup, EndRangeRef.get()); 1535 if (EndExpr.isInvalid()) 1536 return StmtError(); 1537 } 1538 1539 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1540 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1541 if (!Context.hasSameType(BeginType, EndType)) { 1542 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1543 << BeginType << EndType; 1544 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1545 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1546 } 1547 1548 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1549 // Claim the type doesn't contain auto: we've already done the checking. 1550 DeclGroupPtrTy BeginEndGroup = 1551 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1552 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1553 1554 const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); 1555 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1556 VK_LValue, ColonLoc); 1557 if (BeginRef.isInvalid()) 1558 return StmtError(); 1559 1560 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1561 VK_LValue, ColonLoc); 1562 if (EndRef.isInvalid()) 1563 return StmtError(); 1564 1565 // Build and check __begin != __end expression. 1566 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1567 BeginRef.get(), EndRef.get()); 1568 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1569 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1570 if (NotEqExpr.isInvalid()) { 1571 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1572 if (!Context.hasSameType(BeginType, EndType)) 1573 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1574 return StmtError(); 1575 } 1576 1577 // Build and check ++__begin expression. 1578 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1579 VK_LValue, ColonLoc); 1580 if (BeginRef.isInvalid()) 1581 return StmtError(); 1582 1583 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1584 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1585 if (IncrExpr.isInvalid()) { 1586 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1587 return StmtError(); 1588 } 1589 1590 // Build and check *__begin expression. 1591 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1592 VK_LValue, ColonLoc); 1593 if (BeginRef.isInvalid()) 1594 return StmtError(); 1595 1596 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1597 if (DerefExpr.isInvalid()) { 1598 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1599 return StmtError(); 1600 } 1601 1602 // Attach *__begin as initializer for VD. 1603 if (!LoopVar->isInvalidDecl()) { 1604 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1605 /*TypeMayContainAuto=*/true); 1606 if (LoopVar->isInvalidDecl()) 1607 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1608 } 1609 } else { 1610 // The range is implicitly used as a placeholder when it is dependent. 1611 RangeVar->setUsed(); 1612 } 1613 1614 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1615 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1616 NotEqExpr.take(), IncrExpr.take(), 1617 LoopVarDS, /*Body=*/0, ForLoc, 1618 ColonLoc, RParenLoc)); 1619 } 1620 1621 /// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1622 /// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1623 /// body cannot be performed until after the type of the range variable is 1624 /// determined. 1625 StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1626 if (!S || !B) 1627 return StmtError(); 1628 1629 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); 1630 ForStmt->setBody(B); 1631 1632 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, 1633 diag::warn_empty_range_based_for_body); 1634 1635 return S; 1636 } 1637 1638 StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1639 SourceLocation LabelLoc, 1640 LabelDecl *TheDecl) { 1641 getCurFunction()->setHasBranchIntoScope(); 1642 TheDecl->setUsed(); 1643 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1644 } 1645 1646 StmtResult 1647 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1648 Expr *E) { 1649 // Convert operand to void* 1650 if (!E->isTypeDependent()) { 1651 QualType ETy = E->getType(); 1652 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1653 ExprResult ExprRes = Owned(E); 1654 AssignConvertType ConvTy = 1655 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1656 if (ExprRes.isInvalid()) 1657 return StmtError(); 1658 E = ExprRes.take(); 1659 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1660 return StmtError(); 1661 E = MaybeCreateExprWithCleanups(E); 1662 } 1663 1664 getCurFunction()->setHasIndirectGoto(); 1665 1666 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1667 } 1668 1669 StmtResult 1670 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1671 Scope *S = CurScope->getContinueParent(); 1672 if (!S) { 1673 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1674 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1675 } 1676 1677 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1678 } 1679 1680 StmtResult 1681 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1682 Scope *S = CurScope->getBreakParent(); 1683 if (!S) { 1684 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1685 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1686 } 1687 1688 return Owned(new (Context) BreakStmt(BreakLoc)); 1689 } 1690 1691 /// \brief Determine whether the given expression is a candidate for 1692 /// copy elision in either a return statement or a throw expression. 1693 /// 1694 /// \param ReturnType If we're determining the copy elision candidate for 1695 /// a return statement, this is the return type of the function. If we're 1696 /// determining the copy elision candidate for a throw expression, this will 1697 /// be a NULL type. 1698 /// 1699 /// \param E The expression being returned from the function or block, or 1700 /// being thrown. 1701 /// 1702 /// \param AllowFunctionParameter Whether we allow function parameters to 1703 /// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1704 /// we re-use this logic to determine whether we should try to move as part of 1705 /// a return or throw (which does allow function parameters). 1706 /// 1707 /// \returns The NRVO candidate variable, if the return statement may use the 1708 /// NRVO, or NULL if there is no such candidate. 1709 const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1710 Expr *E, 1711 bool AllowFunctionParameter) { 1712 QualType ExprType = E->getType(); 1713 // - in a return statement in a function with ... 1714 // ... a class return type ... 1715 if (!ReturnType.isNull()) { 1716 if (!ReturnType->isRecordType()) 1717 return 0; 1718 // ... the same cv-unqualified type as the function return type ... 1719 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1720 return 0; 1721 } 1722 1723 // ... the expression is the name of a non-volatile automatic object 1724 // (other than a function or catch-clause parameter)) ... 1725 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1726 if (!DR) 1727 return 0; 1728 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1729 if (!VD) 1730 return 0; 1731 1732 // ...object (other than a function or catch-clause parameter)... 1733 if (VD->getKind() != Decl::Var && 1734 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) 1735 return 0; 1736 if (VD->isExceptionVariable()) return 0; 1737 1738 // ...automatic... 1739 if (!VD->hasLocalStorage()) return 0; 1740 1741 // ...non-volatile... 1742 if (VD->getType().isVolatileQualified()) return 0; 1743 if (VD->getType()->isReferenceType()) return 0; 1744 1745 // __block variables can't be allocated in a way that permits NRVO. 1746 if (VD->hasAttr<BlocksAttr>()) return 0; 1747 1748 // Variables with higher required alignment than their type's ABI 1749 // alignment cannot use NRVO. 1750 if (VD->hasAttr<AlignedAttr>() && 1751 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) 1752 return 0; 1753 1754 return VD; 1755 } 1756 1757 /// \brief Perform the initialization of a potentially-movable value, which 1758 /// is the result of return value. 1759 /// 1760 /// This routine implements C++0x [class.copy]p33, which attempts to treat 1761 /// returned lvalues as rvalues in certain cases (to prefer move construction), 1762 /// then falls back to treating them as lvalues if that failed. 1763 ExprResult 1764 Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1765 const VarDecl *NRVOCandidate, 1766 QualType ResultType, 1767 Expr *Value, 1768 bool AllowNRVO) { 1769 // C++0x [class.copy]p33: 1770 // When the criteria for elision of a copy operation are met or would 1771 // be met save for the fact that the source object is a function 1772 // parameter, and the object to be copied is designated by an lvalue, 1773 // overload resolution to select the constructor for the copy is first 1774 // performed as if the object were designated by an rvalue. 1775 ExprResult Res = ExprError(); 1776 if (AllowNRVO && 1777 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 1778 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1779 Value->getType(), CK_LValueToRValue, 1780 Value, VK_XValue); 1781 1782 Expr *InitExpr = &AsRvalue; 1783 InitializationKind Kind 1784 = InitializationKind::CreateCopy(Value->getLocStart(), 1785 Value->getLocStart()); 1786 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 1787 1788 // [...] If overload resolution fails, or if the type of the first 1789 // parameter of the selected constructor is not an rvalue reference 1790 // to the object's type (possibly cv-qualified), overload resolution 1791 // is performed again, considering the object as an lvalue. 1792 if (Seq) { 1793 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 1794 StepEnd = Seq.step_end(); 1795 Step != StepEnd; ++Step) { 1796 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 1797 continue; 1798 1799 CXXConstructorDecl *Constructor 1800 = cast<CXXConstructorDecl>(Step->Function.Function); 1801 1802 const RValueReferenceType *RRefType 1803 = Constructor->getParamDecl(0)->getType() 1804 ->getAs<RValueReferenceType>(); 1805 1806 // If we don't meet the criteria, break out now. 1807 if (!RRefType || 1808 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 1809 Context.getTypeDeclType(Constructor->getParent()))) 1810 break; 1811 1812 // Promote "AsRvalue" to the heap, since we now need this 1813 // expression node to persist. 1814 Value = ImplicitCastExpr::Create(Context, Value->getType(), 1815 CK_LValueToRValue, Value, 0, 1816 VK_XValue); 1817 1818 // Complete type-checking the initialization of the return type 1819 // using the constructor we found. 1820 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 1821 } 1822 } 1823 } 1824 1825 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 1826 // above, or overload resolution failed. Either way, we need to try 1827 // (again) now with the return value expression as written. 1828 if (Res.isInvalid()) 1829 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 1830 1831 return Res; 1832 } 1833 1834 /// ActOnCapScopeReturnStmt - Utility routine to type-check return statements 1835 /// for capturing scopes. 1836 /// 1837 StmtResult 1838 Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1839 // If this is the first return we've seen, infer the return type. 1840 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those 1841 // rules which allows multiple return statements. 1842 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); 1843 if (CurCap->HasImplicitReturnType) { 1844 QualType ReturnT; 1845 if (RetValExp && !isa<InitListExpr>(RetValExp)) { 1846 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 1847 if (Result.isInvalid()) 1848 return StmtError(); 1849 RetValExp = Result.take(); 1850 1851 if (!RetValExp->isTypeDependent()) 1852 ReturnT = RetValExp->getType(); 1853 else 1854 ReturnT = Context.DependentTy; 1855 } else { 1856 if (RetValExp) { 1857 // C++11 [expr.lambda.prim]p4 bans inferring the result from an 1858 // initializer list, because it is not an expression (even 1859 // though we represent it as one). We still deduce 'void'. 1860 Diag(ReturnLoc, diag::err_lambda_return_init_list) 1861 << RetValExp->getSourceRange(); 1862 } 1863 1864 ReturnT = Context.VoidTy; 1865 } 1866 // We require the return types to strictly match here. 1867 if (!CurCap->ReturnType.isNull() && 1868 !CurCap->ReturnType->isDependentType() && 1869 !ReturnT->isDependentType() && 1870 !Context.hasSameType(ReturnT, CurCap->ReturnType)) { 1871 Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible) 1872 << ReturnT << CurCap->ReturnType 1873 << (getCurLambda() != 0); 1874 return StmtError(); 1875 } 1876 CurCap->ReturnType = ReturnT; 1877 } 1878 QualType FnRetType = CurCap->ReturnType; 1879 assert(!FnRetType.isNull()); 1880 1881 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { 1882 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 1883 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); 1884 return StmtError(); 1885 } 1886 } else { 1887 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap); 1888 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){ 1889 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); 1890 return StmtError(); 1891 } 1892 } 1893 1894 // Otherwise, verify that this result type matches the previous one. We are 1895 // pickier with blocks than for normal functions because we don't have GCC 1896 // compatibility to worry about here. 1897 const VarDecl *NRVOCandidate = 0; 1898 if (FnRetType->isDependentType()) { 1899 // Delay processing for now. TODO: there are lots of dependent 1900 // types we can conclusively prove aren't void. 1901 } else if (FnRetType->isVoidType()) { 1902 if (RetValExp && !isa<InitListExpr>(RetValExp) && 1903 !(getLangOpts().CPlusPlus && 1904 (RetValExp->isTypeDependent() || 1905 RetValExp->getType()->isVoidType()))) { 1906 if (!getLangOpts().CPlusPlus && 1907 RetValExp->getType()->isVoidType()) 1908 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; 1909 else { 1910 Diag(ReturnLoc, diag::err_return_block_has_expr); 1911 RetValExp = 0; 1912 } 1913 } 1914 } else if (!RetValExp) { 1915 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 1916 } else if (!RetValExp->isTypeDependent()) { 1917 // we have a non-void block with an expression, continue checking 1918 1919 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1920 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1921 // function return. 1922 1923 // In C++ the return statement is handled via a copy initialization. 1924 // the C version of which boils down to CheckSingleAssignmentConstraints. 1925 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1926 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1927 FnRetType, 1928 NRVOCandidate != 0); 1929 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1930 FnRetType, RetValExp); 1931 if (Res.isInvalid()) { 1932 // FIXME: Cleanup temporaries here, anyway? 1933 return StmtError(); 1934 } 1935 RetValExp = Res.take(); 1936 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1937 } 1938 1939 if (RetValExp) { 1940 CheckImplicitConversions(RetValExp, ReturnLoc); 1941 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1942 } 1943 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 1944 NRVOCandidate); 1945 1946 // If we need to check for the named return value optimization, save the 1947 // return statement in our scope for later processing. 1948 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 1949 !CurContext->isDependentContext()) 1950 FunctionScopes.back()->Returns.push_back(Result); 1951 1952 return Owned(Result); 1953 } 1954 1955 StmtResult 1956 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1957 // Check for unexpanded parameter packs. 1958 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 1959 return StmtError(); 1960 1961 if (isa<CapturingScopeInfo>(getCurFunction())) 1962 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); 1963 1964 QualType FnRetType; 1965 QualType RelatedRetType; 1966 if (const FunctionDecl *FD = getCurFunctionDecl()) { 1967 FnRetType = FD->getResultType(); 1968 if (FD->hasAttr<NoReturnAttr>() || 1969 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 1970 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 1971 << FD->getDeclName(); 1972 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 1973 FnRetType = MD->getResultType(); 1974 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 1975 // In the implementation of a method with a related return type, the 1976 // type used to type-check the validity of return statements within the 1977 // method body is a pointer to the type of the class being implemented. 1978 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 1979 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); 1980 } 1981 } else // If we don't have a function/method context, bail. 1982 return StmtError(); 1983 1984 ReturnStmt *Result = 0; 1985 if (FnRetType->isVoidType()) { 1986 if (RetValExp) { 1987 if (isa<InitListExpr>(RetValExp)) { 1988 // We simply never allow init lists as the return value of void 1989 // functions. This is compatible because this was never allowed before, 1990 // so there's no legacy code to deal with. 1991 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 1992 int FunctionKind = 0; 1993 if (isa<ObjCMethodDecl>(CurDecl)) 1994 FunctionKind = 1; 1995 else if (isa<CXXConstructorDecl>(CurDecl)) 1996 FunctionKind = 2; 1997 else if (isa<CXXDestructorDecl>(CurDecl)) 1998 FunctionKind = 3; 1999 2000 Diag(ReturnLoc, diag::err_return_init_list) 2001 << CurDecl->getDeclName() << FunctionKind 2002 << RetValExp->getSourceRange(); 2003 2004 // Drop the expression. 2005 RetValExp = 0; 2006 } else if (!RetValExp->isTypeDependent()) { 2007 // C99 6.8.6.4p1 (ext_ since GCC warns) 2008 unsigned D = diag::ext_return_has_expr; 2009 if (RetValExp->getType()->isVoidType()) 2010 D = diag::ext_return_has_void_expr; 2011 else { 2012 ExprResult Result = Owned(RetValExp); 2013 Result = IgnoredValueConversions(Result.take()); 2014 if (Result.isInvalid()) 2015 return StmtError(); 2016 RetValExp = Result.take(); 2017 RetValExp = ImpCastExprToType(RetValExp, 2018 Context.VoidTy, CK_ToVoid).take(); 2019 } 2020 2021 // return (some void expression); is legal in C++. 2022 if (D != diag::ext_return_has_void_expr || 2023 !getLangOpts().CPlusPlus) { 2024 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2025 2026 int FunctionKind = 0; 2027 if (isa<ObjCMethodDecl>(CurDecl)) 2028 FunctionKind = 1; 2029 else if (isa<CXXConstructorDecl>(CurDecl)) 2030 FunctionKind = 2; 2031 else if (isa<CXXDestructorDecl>(CurDecl)) 2032 FunctionKind = 3; 2033 2034 Diag(ReturnLoc, D) 2035 << CurDecl->getDeclName() << FunctionKind 2036 << RetValExp->getSourceRange(); 2037 } 2038 } 2039 2040 if (RetValExp) { 2041 CheckImplicitConversions(RetValExp, ReturnLoc); 2042 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2043 } 2044 } 2045 2046 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 2047 } else if (!RetValExp && !FnRetType->isDependentType()) { 2048 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 2049 // C99 6.8.6.4p1 (ext_ since GCC warns) 2050 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; 2051 2052 if (FunctionDecl *FD = getCurFunctionDecl()) 2053 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 2054 else 2055 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 2056 Result = new (Context) ReturnStmt(ReturnLoc); 2057 } else { 2058 const VarDecl *NRVOCandidate = 0; 2059 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 2060 // we have a non-void function with an expression, continue checking 2061 2062 if (!RelatedRetType.isNull()) { 2063 // If we have a related result type, perform an extra conversion here. 2064 // FIXME: The diagnostics here don't really describe what is happening. 2065 InitializedEntity Entity = 2066 InitializedEntity::InitializeTemporary(RelatedRetType); 2067 2068 ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), 2069 RetValExp); 2070 if (Res.isInvalid()) { 2071 // FIXME: Cleanup temporaries here, anyway? 2072 return StmtError(); 2073 } 2074 RetValExp = Res.takeAs<Expr>(); 2075 } 2076 2077 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2078 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2079 // function return. 2080 2081 // In C++ the return statement is handled via a copy initialization, 2082 // the C version of which boils down to CheckSingleAssignmentConstraints. 2083 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2084 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2085 FnRetType, 2086 NRVOCandidate != 0); 2087 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2088 FnRetType, RetValExp); 2089 if (Res.isInvalid()) { 2090 // FIXME: Cleanup temporaries here, anyway? 2091 return StmtError(); 2092 } 2093 2094 RetValExp = Res.takeAs<Expr>(); 2095 if (RetValExp) 2096 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2097 } 2098 2099 if (RetValExp) { 2100 CheckImplicitConversions(RetValExp, ReturnLoc); 2101 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2102 } 2103 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 2104 } 2105 2106 // If we need to check for the named return value optimization, save the 2107 // return statement in our scope for later processing. 2108 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2109 !CurContext->isDependentContext()) 2110 FunctionScopes.back()->Returns.push_back(Result); 2111 2112 return Owned(Result); 2113 } 2114 2115 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 2116 /// ignore "noop" casts in places where an lvalue is required by an inline asm. 2117 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but 2118 /// provide a strong guidance to not use it. 2119 /// 2120 /// This method checks to see if the argument is an acceptable l-value and 2121 /// returns false if it is a case we can handle. 2122 static bool CheckAsmLValue(const Expr *E, Sema &S) { 2123 // Type dependent expressions will be checked during instantiation. 2124 if (E->isTypeDependent()) 2125 return false; 2126 2127 if (E->isLValue()) 2128 return false; // Cool, this is an lvalue. 2129 2130 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 2131 // are supposed to allow. 2132 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 2133 if (E != E2 && E2->isLValue()) { 2134 if (!S.getLangOpts().HeinousExtensions) 2135 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 2136 << E->getSourceRange(); 2137 else 2138 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 2139 << E->getSourceRange(); 2140 // Accept, even if we emitted an error diagnostic. 2141 return false; 2142 } 2143 2144 // None of the above, just randomly invalid non-lvalue. 2145 return true; 2146 } 2147 2148 /// isOperandMentioned - Return true if the specified operand # is mentioned 2149 /// anywhere in the decomposed asm string. 2150 static bool isOperandMentioned(unsigned OpNo, 2151 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 2152 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 2153 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 2154 if (!Piece.isOperand()) continue; 2155 2156 // If this is a reference to the input and if the input was the smaller 2157 // one, then we have to reject this asm. 2158 if (Piece.getOperandNo() == OpNo) 2159 return true; 2160 } 2161 2162 return false; 2163 } 2164 2165 StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 2166 bool IsVolatile, unsigned NumOutputs, 2167 unsigned NumInputs, IdentifierInfo **Names, 2168 MultiExprArg constraints, MultiExprArg exprs, 2169 Expr *asmString, MultiExprArg clobbers, 2170 SourceLocation RParenLoc, bool MSAsm) { 2171 unsigned NumClobbers = clobbers.size(); 2172 StringLiteral **Constraints = 2173 reinterpret_cast<StringLiteral**>(constraints.get()); 2174 Expr **Exprs = exprs.get(); 2175 StringLiteral *AsmString = cast<StringLiteral>(asmString); 2176 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 2177 2178 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2179 2180 // The parser verifies that there is a string literal here. 2181 if (!AsmString->isAscii()) 2182 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2183 << AsmString->getSourceRange()); 2184 2185 for (unsigned i = 0; i != NumOutputs; i++) { 2186 StringLiteral *Literal = Constraints[i]; 2187 if (!Literal->isAscii()) 2188 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2189 << Literal->getSourceRange()); 2190 2191 StringRef OutputName; 2192 if (Names[i]) 2193 OutputName = Names[i]->getName(); 2194 2195 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2196 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2197 return StmtError(Diag(Literal->getLocStart(), 2198 diag::err_asm_invalid_output_constraint) 2199 << Info.getConstraintStr()); 2200 2201 // Check that the output exprs are valid lvalues. 2202 Expr *OutputExpr = Exprs[i]; 2203 if (CheckAsmLValue(OutputExpr, *this)) { 2204 return StmtError(Diag(OutputExpr->getLocStart(), 2205 diag::err_asm_invalid_lvalue_in_output) 2206 << OutputExpr->getSourceRange()); 2207 } 2208 2209 OutputConstraintInfos.push_back(Info); 2210 } 2211 2212 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2213 2214 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2215 StringLiteral *Literal = Constraints[i]; 2216 if (!Literal->isAscii()) 2217 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2218 << Literal->getSourceRange()); 2219 2220 StringRef InputName; 2221 if (Names[i]) 2222 InputName = Names[i]->getName(); 2223 2224 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2225 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2226 NumOutputs, Info)) { 2227 return StmtError(Diag(Literal->getLocStart(), 2228 diag::err_asm_invalid_input_constraint) 2229 << Info.getConstraintStr()); 2230 } 2231 2232 Expr *InputExpr = Exprs[i]; 2233 2234 // Only allow void types for memory constraints. 2235 if (Info.allowsMemory() && !Info.allowsRegister()) { 2236 if (CheckAsmLValue(InputExpr, *this)) 2237 return StmtError(Diag(InputExpr->getLocStart(), 2238 diag::err_asm_invalid_lvalue_in_input) 2239 << Info.getConstraintStr() 2240 << InputExpr->getSourceRange()); 2241 } 2242 2243 if (Info.allowsRegister()) { 2244 if (InputExpr->getType()->isVoidType()) { 2245 return StmtError(Diag(InputExpr->getLocStart(), 2246 diag::err_asm_invalid_type_in_input) 2247 << InputExpr->getType() << Info.getConstraintStr() 2248 << InputExpr->getSourceRange()); 2249 } 2250 } 2251 2252 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2253 if (Result.isInvalid()) 2254 return StmtError(); 2255 2256 Exprs[i] = Result.take(); 2257 InputConstraintInfos.push_back(Info); 2258 } 2259 2260 // Check that the clobbers are valid. 2261 for (unsigned i = 0; i != NumClobbers; i++) { 2262 StringLiteral *Literal = Clobbers[i]; 2263 if (!Literal->isAscii()) 2264 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2265 << Literal->getSourceRange()); 2266 2267 StringRef Clobber = Literal->getString(); 2268 2269 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2270 return StmtError(Diag(Literal->getLocStart(), 2271 diag::err_asm_unknown_register_name) << Clobber); 2272 } 2273 2274 AsmStmt *NS = 2275 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2276 NumOutputs, NumInputs, Names, Constraints, Exprs, 2277 AsmString, NumClobbers, Clobbers, RParenLoc); 2278 // Validate the asm string, ensuring it makes sense given the operands we 2279 // have. 2280 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2281 unsigned DiagOffs; 2282 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2283 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2284 << AsmString->getSourceRange(); 2285 return StmtError(); 2286 } 2287 2288 // Validate tied input operands for type mismatches. 2289 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2290 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2291 2292 // If this is a tied constraint, verify that the output and input have 2293 // either exactly the same type, or that they are int/ptr operands with the 2294 // same size (int/long, int*/long, are ok etc). 2295 if (!Info.hasTiedOperand()) continue; 2296 2297 unsigned TiedTo = Info.getTiedOperand(); 2298 unsigned InputOpNo = i+NumOutputs; 2299 Expr *OutputExpr = Exprs[TiedTo]; 2300 Expr *InputExpr = Exprs[InputOpNo]; 2301 2302 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) 2303 continue; 2304 2305 QualType InTy = InputExpr->getType(); 2306 QualType OutTy = OutputExpr->getType(); 2307 if (Context.hasSameType(InTy, OutTy)) 2308 continue; // All types can be tied to themselves. 2309 2310 // Decide if the input and output are in the same domain (integer/ptr or 2311 // floating point. 2312 enum AsmDomain { 2313 AD_Int, AD_FP, AD_Other 2314 } InputDomain, OutputDomain; 2315 2316 if (InTy->isIntegerType() || InTy->isPointerType()) 2317 InputDomain = AD_Int; 2318 else if (InTy->isRealFloatingType()) 2319 InputDomain = AD_FP; 2320 else 2321 InputDomain = AD_Other; 2322 2323 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2324 OutputDomain = AD_Int; 2325 else if (OutTy->isRealFloatingType()) 2326 OutputDomain = AD_FP; 2327 else 2328 OutputDomain = AD_Other; 2329 2330 // They are ok if they are the same size and in the same domain. This 2331 // allows tying things like: 2332 // void* to int* 2333 // void* to int if they are the same size. 2334 // double to long double if they are the same size. 2335 // 2336 uint64_t OutSize = Context.getTypeSize(OutTy); 2337 uint64_t InSize = Context.getTypeSize(InTy); 2338 if (OutSize == InSize && InputDomain == OutputDomain && 2339 InputDomain != AD_Other) 2340 continue; 2341 2342 // If the smaller input/output operand is not mentioned in the asm string, 2343 // then we can promote the smaller one to a larger input and the asm string 2344 // won't notice. 2345 bool SmallerValueMentioned = false; 2346 2347 // If this is a reference to the input and if the input was the smaller 2348 // one, then we have to reject this asm. 2349 if (isOperandMentioned(InputOpNo, Pieces)) { 2350 // This is a use in the asm string of the smaller operand. Since we 2351 // codegen this by promoting to a wider value, the asm will get printed 2352 // "wrong". 2353 SmallerValueMentioned |= InSize < OutSize; 2354 } 2355 if (isOperandMentioned(TiedTo, Pieces)) { 2356 // If this is a reference to the output, and if the output is the larger 2357 // value, then it's ok because we'll promote the input to the larger type. 2358 SmallerValueMentioned |= OutSize < InSize; 2359 } 2360 2361 // If the smaller value wasn't mentioned in the asm string, and if the 2362 // output was a register, just extend the shorter one to the size of the 2363 // larger one. 2364 if (!SmallerValueMentioned && InputDomain != AD_Other && 2365 OutputConstraintInfos[TiedTo].allowsRegister()) 2366 continue; 2367 2368 // Either both of the operands were mentioned or the smaller one was 2369 // mentioned. One more special case that we'll allow: if the tied input is 2370 // integer, unmentioned, and is a constant, then we'll allow truncating it 2371 // down to the size of the destination. 2372 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2373 !isOperandMentioned(InputOpNo, Pieces) && 2374 InputExpr->isEvaluatable(Context)) { 2375 CastKind castKind = 2376 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2377 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2378 Exprs[InputOpNo] = InputExpr; 2379 NS->setInputExpr(i, InputExpr); 2380 continue; 2381 } 2382 2383 Diag(InputExpr->getLocStart(), 2384 diag::err_asm_tying_incompatible_types) 2385 << InTy << OutTy << OutputExpr->getSourceRange() 2386 << InputExpr->getSourceRange(); 2387 return StmtError(); 2388 } 2389 2390 return Owned(NS); 2391 } 2392 2393 StmtResult 2394 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2395 SourceLocation RParen, Decl *Parm, 2396 Stmt *Body) { 2397 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2398 if (Var && Var->isInvalidDecl()) 2399 return StmtError(); 2400 2401 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2402 } 2403 2404 StmtResult 2405 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2406 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2407 } 2408 2409 StmtResult 2410 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2411 MultiStmtArg CatchStmts, Stmt *Finally) { 2412 if (!getLangOpts().ObjCExceptions) 2413 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2414 2415 getCurFunction()->setHasBranchProtectedScope(); 2416 unsigned NumCatchStmts = CatchStmts.size(); 2417 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2418 CatchStmts.release(), 2419 NumCatchStmts, 2420 Finally)); 2421 } 2422 2423 StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2424 Expr *Throw) { 2425 if (Throw) { 2426 Throw = MaybeCreateExprWithCleanups(Throw); 2427 ExprResult Result = DefaultLvalueConversion(Throw); 2428 if (Result.isInvalid()) 2429 return StmtError(); 2430 2431 Throw = Result.take(); 2432 QualType ThrowType = Throw->getType(); 2433 // Make sure the expression type is an ObjC pointer or "void *". 2434 if (!ThrowType->isDependentType() && 2435 !ThrowType->isObjCObjectPointerType()) { 2436 const PointerType *PT = ThrowType->getAs<PointerType>(); 2437 if (!PT || !PT->getPointeeType()->isVoidType()) 2438 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2439 << Throw->getType() << Throw->getSourceRange()); 2440 } 2441 } 2442 2443 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2444 } 2445 2446 StmtResult 2447 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2448 Scope *CurScope) { 2449 if (!getLangOpts().ObjCExceptions) 2450 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2451 2452 if (!Throw) { 2453 // @throw without an expression designates a rethrow (which much occur 2454 // in the context of an @catch clause). 2455 Scope *AtCatchParent = CurScope; 2456 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2457 AtCatchParent = AtCatchParent->getParent(); 2458 if (!AtCatchParent) 2459 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2460 } 2461 2462 return BuildObjCAtThrowStmt(AtLoc, Throw); 2463 } 2464 2465 ExprResult 2466 Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2467 ExprResult result = DefaultLvalueConversion(operand); 2468 if (result.isInvalid()) 2469 return ExprError(); 2470 operand = result.take(); 2471 2472 // Make sure the expression type is an ObjC pointer or "void *". 2473 QualType type = operand->getType(); 2474 if (!type->isDependentType() && 2475 !type->isObjCObjectPointerType()) { 2476 const PointerType *pointerType = type->getAs<PointerType>(); 2477 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2478 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2479 << type << operand->getSourceRange(); 2480 } 2481 2482 // The operand to @synchronized is a full-expression. 2483 return MaybeCreateExprWithCleanups(operand); 2484 } 2485 2486 StmtResult 2487 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2488 Stmt *SyncBody) { 2489 // We can't jump into or indirect-jump out of a @synchronized block. 2490 getCurFunction()->setHasBranchProtectedScope(); 2491 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2492 } 2493 2494 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2495 /// and creates a proper catch handler from them. 2496 StmtResult 2497 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2498 Stmt *HandlerBlock) { 2499 // There's nothing to test that ActOnExceptionDecl didn't already test. 2500 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2501 cast_or_null<VarDecl>(ExDecl), 2502 HandlerBlock)); 2503 } 2504 2505 StmtResult 2506 Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2507 getCurFunction()->setHasBranchProtectedScope(); 2508 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2509 } 2510 2511 namespace { 2512 2513 class TypeWithHandler { 2514 QualType t; 2515 CXXCatchStmt *stmt; 2516 public: 2517 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2518 : t(type), stmt(statement) {} 2519 2520 // An arbitrary order is fine as long as it places identical 2521 // types next to each other. 2522 bool operator<(const TypeWithHandler &y) const { 2523 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2524 return true; 2525 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2526 return false; 2527 else 2528 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2529 } 2530 2531 bool operator==(const TypeWithHandler& other) const { 2532 return t == other.t; 2533 } 2534 2535 CXXCatchStmt *getCatchStmt() const { return stmt; } 2536 SourceLocation getTypeSpecStartLoc() const { 2537 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2538 } 2539 }; 2540 2541 } 2542 2543 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2544 /// handlers and creates a try statement from them. 2545 StmtResult 2546 Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2547 MultiStmtArg RawHandlers) { 2548 // Don't report an error if 'try' is used in system headers. 2549 if (!getLangOpts().CXXExceptions && 2550 !getSourceManager().isInSystemHeader(TryLoc)) 2551 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2552 2553 unsigned NumHandlers = RawHandlers.size(); 2554 assert(NumHandlers > 0 && 2555 "The parser shouldn't call this if there are no handlers."); 2556 Stmt **Handlers = RawHandlers.get(); 2557 2558 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2559 2560 for (unsigned i = 0; i < NumHandlers; ++i) { 2561 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 2562 if (!Handler->getExceptionDecl()) { 2563 if (i < NumHandlers - 1) 2564 return StmtError(Diag(Handler->getLocStart(), 2565 diag::err_early_catch_all)); 2566 2567 continue; 2568 } 2569 2570 const QualType CaughtType = Handler->getCaughtType(); 2571 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2572 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2573 } 2574 2575 // Detect handlers for the same type as an earlier one. 2576 if (NumHandlers > 1) { 2577 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2578 2579 TypeWithHandler prev = TypesWithHandlers[0]; 2580 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2581 TypeWithHandler curr = TypesWithHandlers[i]; 2582 2583 if (curr == prev) { 2584 Diag(curr.getTypeSpecStartLoc(), 2585 diag::warn_exception_caught_by_earlier_handler) 2586 << curr.getCatchStmt()->getCaughtType().getAsString(); 2587 Diag(prev.getTypeSpecStartLoc(), 2588 diag::note_previous_exception_handler) 2589 << prev.getCatchStmt()->getCaughtType().getAsString(); 2590 } 2591 2592 prev = curr; 2593 } 2594 } 2595 2596 getCurFunction()->setHasBranchProtectedScope(); 2597 2598 // FIXME: We should detect handlers that cannot catch anything because an 2599 // earlier handler catches a superclass. Need to find a method that is not 2600 // quadratic for this. 2601 // Neither of these are explicitly forbidden, but every compiler detects them 2602 // and warns. 2603 2604 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2605 Handlers, NumHandlers)); 2606 } 2607 2608 StmtResult 2609 Sema::ActOnSEHTryBlock(bool IsCXXTry, 2610 SourceLocation TryLoc, 2611 Stmt *TryBlock, 2612 Stmt *Handler) { 2613 assert(TryBlock && Handler); 2614 2615 getCurFunction()->setHasBranchProtectedScope(); 2616 2617 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2618 } 2619 2620 StmtResult 2621 Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2622 Expr *FilterExpr, 2623 Stmt *Block) { 2624 assert(FilterExpr && Block); 2625 2626 if(!FilterExpr->getType()->isIntegerType()) { 2627 return StmtError(Diag(FilterExpr->getExprLoc(), 2628 diag::err_filter_expression_integral) 2629 << FilterExpr->getType()); 2630 } 2631 2632 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2633 } 2634 2635 StmtResult 2636 Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2637 Stmt *Block) { 2638 assert(Block); 2639 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2640 } 2641 2642 StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, 2643 bool IsIfExists, 2644 NestedNameSpecifierLoc QualifierLoc, 2645 DeclarationNameInfo NameInfo, 2646 Stmt *Nested) 2647 { 2648 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, 2649 QualifierLoc, NameInfo, 2650 cast<CompoundStmt>(Nested)); 2651 } 2652 2653 2654 StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, 2655 bool IsIfExists, 2656 CXXScopeSpec &SS, 2657 UnqualifiedId &Name, 2658 Stmt *Nested) { 2659 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, 2660 SS.getWithLocInContext(Context), 2661 GetNameFromUnqualifiedId(Name), 2662 Nested); 2663 } 2664