SemaStmt.cpp revision d10099e5c8238fa0327f03921cf2e3c8975c881e
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/EvaluatedExprVisitor.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/ExprObjC.h" 25#include "clang/AST/StmtObjC.h" 26#include "clang/AST/StmtCXX.h" 27#include "clang/AST/TypeLoc.h" 28#include "clang/Lex/Preprocessor.h" 29#include "clang/Basic/TargetInfo.h" 30#include "llvm/ADT/ArrayRef.h" 31#include "llvm/ADT/STLExtras.h" 32#include "llvm/ADT/SmallPtrSet.h" 33#include "llvm/ADT/SmallVector.h" 34using namespace clang; 35using namespace sema; 36 37StmtResult Sema::ActOnExprStmt(FullExprArg expr) { 38 Expr *E = expr.get(); 39 if (!E) // FIXME: FullExprArg has no error state? 40 return StmtError(); 41 42 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 43 // void expression for its side effects. Conversion to void allows any 44 // operand, even incomplete types. 45 46 // Same thing in for stmt first clause (when expr) and third clause. 47 return Owned(static_cast<Stmt*>(E)); 48} 49 50 51StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, 52 bool HasLeadingEmptyMacro) { 53 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); 54} 55 56StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, 57 SourceLocation EndLoc) { 58 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 59 60 // If we have an invalid decl, just return an error. 61 if (DG.isNull()) return StmtError(); 62 63 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 64} 65 66void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { 67 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 68 69 // If we have an invalid decl, just return. 70 if (DG.isNull() || !DG.isSingleDecl()) return; 71 VarDecl *var = cast<VarDecl>(DG.getSingleDecl()); 72 73 // suppress any potential 'unused variable' warning. 74 var->setUsed(); 75 76 // foreach variables are never actually initialized in the way that 77 // the parser came up with. 78 var->setInit(0); 79 80 // In ARC, we don't need to retain the iteration variable of a fast 81 // enumeration loop. Rather than actually trying to catch that 82 // during declaration processing, we remove the consequences here. 83 if (getLangOpts().ObjCAutoRefCount) { 84 QualType type = var->getType(); 85 86 // Only do this if we inferred the lifetime. Inferred lifetime 87 // will show up as a local qualifier because explicit lifetime 88 // should have shown up as an AttributedType instead. 89 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { 90 // Add 'const' and mark the variable as pseudo-strong. 91 var->setType(type.withConst()); 92 var->setARCPseudoStrong(true); 93 } 94 } 95} 96 97/// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. 98/// 99/// Adding a cast to void (or other expression wrappers) will prevent the 100/// warning from firing. 101static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { 102 SourceLocation Loc; 103 bool IsNotEqual, CanAssign; 104 105 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { 106 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) 107 return false; 108 109 Loc = Op->getOperatorLoc(); 110 IsNotEqual = Op->getOpcode() == BO_NE; 111 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); 112 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { 113 if (Op->getOperator() != OO_EqualEqual && 114 Op->getOperator() != OO_ExclaimEqual) 115 return false; 116 117 Loc = Op->getOperatorLoc(); 118 IsNotEqual = Op->getOperator() == OO_ExclaimEqual; 119 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); 120 } else { 121 // Not a typo-prone comparison. 122 return false; 123 } 124 125 // Suppress warnings when the operator, suspicious as it may be, comes from 126 // a macro expansion. 127 if (Loc.isMacroID()) 128 return false; 129 130 S.Diag(Loc, diag::warn_unused_comparison) 131 << (unsigned)IsNotEqual << E->getSourceRange(); 132 133 // If the LHS is a plausible entity to assign to, provide a fixit hint to 134 // correct common typos. 135 if (CanAssign) { 136 if (IsNotEqual) 137 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) 138 << FixItHint::CreateReplacement(Loc, "|="); 139 else 140 S.Diag(Loc, diag::note_equality_comparison_to_assign) 141 << FixItHint::CreateReplacement(Loc, "="); 142 } 143 144 return true; 145} 146 147void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 148 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 149 return DiagnoseUnusedExprResult(Label->getSubStmt()); 150 151 const Expr *E = dyn_cast_or_null<Expr>(S); 152 if (!E) 153 return; 154 155 SourceLocation Loc; 156 SourceRange R1, R2; 157 if (SourceMgr.isInSystemMacro(E->getExprLoc()) || 158 !E->isUnusedResultAWarning(Loc, R1, R2, Context)) 159 return; 160 161 // Okay, we have an unused result. Depending on what the base expression is, 162 // we might want to make a more specific diagnostic. Check for one of these 163 // cases now. 164 unsigned DiagID = diag::warn_unused_expr; 165 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 166 E = Temps->getSubExpr(); 167 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 168 E = TempExpr->getSubExpr(); 169 170 if (DiagnoseUnusedComparison(*this, E)) 171 return; 172 173 E = E->IgnoreParenImpCasts(); 174 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 175 if (E->getType()->isVoidType()) 176 return; 177 178 // If the callee has attribute pure, const, or warn_unused_result, warn with 179 // a more specific message to make it clear what is happening. 180 if (const Decl *FD = CE->getCalleeDecl()) { 181 if (FD->getAttr<WarnUnusedResultAttr>()) { 182 Diag(Loc, diag::warn_unused_result) << R1 << R2; 183 return; 184 } 185 if (FD->getAttr<PureAttr>()) { 186 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 187 return; 188 } 189 if (FD->getAttr<ConstAttr>()) { 190 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 191 return; 192 } 193 } 194 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 195 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { 196 Diag(Loc, diag::err_arc_unused_init_message) << R1; 197 return; 198 } 199 const ObjCMethodDecl *MD = ME->getMethodDecl(); 200 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 201 Diag(Loc, diag::warn_unused_result) << R1 << R2; 202 return; 203 } 204 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 205 const Expr *Source = POE->getSyntacticForm(); 206 if (isa<ObjCSubscriptRefExpr>(Source)) 207 DiagID = diag::warn_unused_container_subscript_expr; 208 else 209 DiagID = diag::warn_unused_property_expr; 210 } else if (const CXXFunctionalCastExpr *FC 211 = dyn_cast<CXXFunctionalCastExpr>(E)) { 212 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 213 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 214 return; 215 } 216 // Diagnose "(void*) blah" as a typo for "(void) blah". 217 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 218 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 219 QualType T = TI->getType(); 220 221 // We really do want to use the non-canonical type here. 222 if (T == Context.VoidPtrTy) { 223 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 224 225 Diag(Loc, diag::warn_unused_voidptr) 226 << FixItHint::CreateRemoval(TL.getStarLoc()); 227 return; 228 } 229 } 230 231 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 232} 233 234void Sema::ActOnStartOfCompoundStmt() { 235 PushCompoundScope(); 236} 237 238void Sema::ActOnFinishOfCompoundStmt() { 239 PopCompoundScope(); 240} 241 242sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { 243 return getCurFunction()->CompoundScopes.back(); 244} 245 246StmtResult 247Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 248 MultiStmtArg elts, bool isStmtExpr) { 249 unsigned NumElts = elts.size(); 250 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 251 // If we're in C89 mode, check that we don't have any decls after stmts. If 252 // so, emit an extension diagnostic. 253 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { 254 // Note that __extension__ can be around a decl. 255 unsigned i = 0; 256 // Skip over all declarations. 257 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 258 /*empty*/; 259 260 // We found the end of the list or a statement. Scan for another declstmt. 261 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 262 /*empty*/; 263 264 if (i != NumElts) { 265 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 266 Diag(D->getLocation(), diag::ext_mixed_decls_code); 267 } 268 } 269 // Warn about unused expressions in statements. 270 for (unsigned i = 0; i != NumElts; ++i) { 271 // Ignore statements that are last in a statement expression. 272 if (isStmtExpr && i == NumElts - 1) 273 continue; 274 275 DiagnoseUnusedExprResult(Elts[i]); 276 } 277 278 // Check for suspicious empty body (null statement) in `for' and `while' 279 // statements. Don't do anything for template instantiations, this just adds 280 // noise. 281 if (NumElts != 0 && !CurrentInstantiationScope && 282 getCurCompoundScope().HasEmptyLoopBodies) { 283 for (unsigned i = 0; i != NumElts - 1; ++i) 284 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); 285 } 286 287 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 288} 289 290StmtResult 291Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 292 SourceLocation DotDotDotLoc, Expr *RHSVal, 293 SourceLocation ColonLoc) { 294 assert((LHSVal != 0) && "missing expression in case statement"); 295 296 if (getCurFunction()->SwitchStack.empty()) { 297 Diag(CaseLoc, diag::err_case_not_in_switch); 298 return StmtError(); 299 } 300 301 if (!getLangOpts().CPlusPlus0x) { 302 // C99 6.8.4.2p3: The expression shall be an integer constant. 303 // However, GCC allows any evaluatable integer expression. 304 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { 305 LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); 306 if (!LHSVal) 307 return StmtError(); 308 } 309 310 // GCC extension: The expression shall be an integer constant. 311 312 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { 313 RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); 314 // Recover from an error by just forgetting about it. 315 } 316 } 317 318 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 319 ColonLoc); 320 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 321 return Owned(CS); 322} 323 324/// ActOnCaseStmtBody - This installs a statement as the body of a case. 325void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 326 DiagnoseUnusedExprResult(SubStmt); 327 328 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 329 CS->setSubStmt(SubStmt); 330} 331 332StmtResult 333Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 334 Stmt *SubStmt, Scope *CurScope) { 335 DiagnoseUnusedExprResult(SubStmt); 336 337 if (getCurFunction()->SwitchStack.empty()) { 338 Diag(DefaultLoc, diag::err_default_not_in_switch); 339 return Owned(SubStmt); 340 } 341 342 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 343 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 344 return Owned(DS); 345} 346 347StmtResult 348Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 349 SourceLocation ColonLoc, Stmt *SubStmt) { 350 // If the label was multiply defined, reject it now. 351 if (TheDecl->getStmt()) { 352 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 353 Diag(TheDecl->getLocation(), diag::note_previous_definition); 354 return Owned(SubStmt); 355 } 356 357 // Otherwise, things are good. Fill in the declaration and return it. 358 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 359 TheDecl->setStmt(LS); 360 if (!TheDecl->isGnuLocal()) 361 TheDecl->setLocation(IdentLoc); 362 return Owned(LS); 363} 364 365StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, 366 const AttrVec &Attrs, 367 Stmt *SubStmt) { 368 // Fill in the declaration and return it. Variable length will require to 369 // change this to AttributedStmt::Create(Context, ....); 370 // and probably using ArrayRef 371 AttributedStmt *LS = new (Context) AttributedStmt(AttrLoc, Attrs, SubStmt); 372 return Owned(LS); 373} 374 375StmtResult 376Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 377 Stmt *thenStmt, SourceLocation ElseLoc, 378 Stmt *elseStmt) { 379 ExprResult CondResult(CondVal.release()); 380 381 VarDecl *ConditionVar = 0; 382 if (CondVar) { 383 ConditionVar = cast<VarDecl>(CondVar); 384 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 385 if (CondResult.isInvalid()) 386 return StmtError(); 387 } 388 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 389 if (!ConditionExpr) 390 return StmtError(); 391 392 DiagnoseUnusedExprResult(thenStmt); 393 394 if (!elseStmt) { 395 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, 396 diag::warn_empty_if_body); 397 } 398 399 DiagnoseUnusedExprResult(elseStmt); 400 401 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 402 thenStmt, ElseLoc, elseStmt)); 403} 404 405/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 406/// the specified width and sign. If an overflow occurs, detect it and emit 407/// the specified diagnostic. 408void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 409 unsigned NewWidth, bool NewSign, 410 SourceLocation Loc, 411 unsigned DiagID) { 412 // Perform a conversion to the promoted condition type if needed. 413 if (NewWidth > Val.getBitWidth()) { 414 // If this is an extension, just do it. 415 Val = Val.extend(NewWidth); 416 Val.setIsSigned(NewSign); 417 418 // If the input was signed and negative and the output is 419 // unsigned, don't bother to warn: this is implementation-defined 420 // behavior. 421 // FIXME: Introduce a second, default-ignored warning for this case? 422 } else if (NewWidth < Val.getBitWidth()) { 423 // If this is a truncation, check for overflow. 424 llvm::APSInt ConvVal(Val); 425 ConvVal = ConvVal.trunc(NewWidth); 426 ConvVal.setIsSigned(NewSign); 427 ConvVal = ConvVal.extend(Val.getBitWidth()); 428 ConvVal.setIsSigned(Val.isSigned()); 429 if (ConvVal != Val) 430 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 431 432 // Regardless of whether a diagnostic was emitted, really do the 433 // truncation. 434 Val = Val.trunc(NewWidth); 435 Val.setIsSigned(NewSign); 436 } else if (NewSign != Val.isSigned()) { 437 // Convert the sign to match the sign of the condition. This can cause 438 // overflow as well: unsigned(INTMIN) 439 // We don't diagnose this overflow, because it is implementation-defined 440 // behavior. 441 // FIXME: Introduce a second, default-ignored warning for this case? 442 llvm::APSInt OldVal(Val); 443 Val.setIsSigned(NewSign); 444 } 445} 446 447namespace { 448 struct CaseCompareFunctor { 449 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 450 const llvm::APSInt &RHS) { 451 return LHS.first < RHS; 452 } 453 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 454 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 455 return LHS.first < RHS.first; 456 } 457 bool operator()(const llvm::APSInt &LHS, 458 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 459 return LHS < RHS.first; 460 } 461 }; 462} 463 464/// CmpCaseVals - Comparison predicate for sorting case values. 465/// 466static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 467 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 468 if (lhs.first < rhs.first) 469 return true; 470 471 if (lhs.first == rhs.first && 472 lhs.second->getCaseLoc().getRawEncoding() 473 < rhs.second->getCaseLoc().getRawEncoding()) 474 return true; 475 return false; 476} 477 478/// CmpEnumVals - Comparison predicate for sorting enumeration values. 479/// 480static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 481 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 482{ 483 return lhs.first < rhs.first; 484} 485 486/// EqEnumVals - Comparison preficate for uniqing enumeration values. 487/// 488static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 489 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 490{ 491 return lhs.first == rhs.first; 492} 493 494/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 495/// potentially integral-promoted expression @p expr. 496static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 497 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 498 expr = cleanups->getSubExpr(); 499 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 500 if (impcast->getCastKind() != CK_IntegralCast) break; 501 expr = impcast->getSubExpr(); 502 } 503 return expr->getType(); 504} 505 506StmtResult 507Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 508 Decl *CondVar) { 509 ExprResult CondResult; 510 511 VarDecl *ConditionVar = 0; 512 if (CondVar) { 513 ConditionVar = cast<VarDecl>(CondVar); 514 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 515 if (CondResult.isInvalid()) 516 return StmtError(); 517 518 Cond = CondResult.release(); 519 } 520 521 if (!Cond) 522 return StmtError(); 523 524 CondResult 525 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, 526 PDiag(diag::err_typecheck_statement_requires_integer), 527 PDiag(diag::err_switch_incomplete_class_type) 528 << Cond->getSourceRange(), 529 PDiag(diag::err_switch_explicit_conversion), 530 PDiag(diag::note_switch_conversion), 531 PDiag(diag::err_switch_multiple_conversions), 532 PDiag(diag::note_switch_conversion), 533 PDiag(0), 534 /*AllowScopedEnumerations*/ true); 535 if (CondResult.isInvalid()) return StmtError(); 536 Cond = CondResult.take(); 537 538 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 539 CondResult = UsualUnaryConversions(Cond); 540 if (CondResult.isInvalid()) return StmtError(); 541 Cond = CondResult.take(); 542 543 if (!CondVar) { 544 CheckImplicitConversions(Cond, SwitchLoc); 545 CondResult = MaybeCreateExprWithCleanups(Cond); 546 if (CondResult.isInvalid()) 547 return StmtError(); 548 Cond = CondResult.take(); 549 } 550 551 getCurFunction()->setHasBranchIntoScope(); 552 553 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 554 getCurFunction()->SwitchStack.push_back(SS); 555 return Owned(SS); 556} 557 558static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 559 if (Val.getBitWidth() < BitWidth) 560 Val = Val.extend(BitWidth); 561 else if (Val.getBitWidth() > BitWidth) 562 Val = Val.trunc(BitWidth); 563 Val.setIsSigned(IsSigned); 564} 565 566StmtResult 567Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 568 Stmt *BodyStmt) { 569 SwitchStmt *SS = cast<SwitchStmt>(Switch); 570 assert(SS == getCurFunction()->SwitchStack.back() && 571 "switch stack missing push/pop!"); 572 573 SS->setBody(BodyStmt, SwitchLoc); 574 getCurFunction()->SwitchStack.pop_back(); 575 576 Expr *CondExpr = SS->getCond(); 577 if (!CondExpr) return StmtError(); 578 579 QualType CondType = CondExpr->getType(); 580 581 Expr *CondExprBeforePromotion = CondExpr; 582 QualType CondTypeBeforePromotion = 583 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 584 585 // C++ 6.4.2.p2: 586 // Integral promotions are performed (on the switch condition). 587 // 588 // A case value unrepresentable by the original switch condition 589 // type (before the promotion) doesn't make sense, even when it can 590 // be represented by the promoted type. Therefore we need to find 591 // the pre-promotion type of the switch condition. 592 if (!CondExpr->isTypeDependent()) { 593 // We have already converted the expression to an integral or enumeration 594 // type, when we started the switch statement. If we don't have an 595 // appropriate type now, just return an error. 596 if (!CondType->isIntegralOrEnumerationType()) 597 return StmtError(); 598 599 if (CondExpr->isKnownToHaveBooleanValue()) { 600 // switch(bool_expr) {...} is often a programmer error, e.g. 601 // switch(n && mask) { ... } // Doh - should be "n & mask". 602 // One can always use an if statement instead of switch(bool_expr). 603 Diag(SwitchLoc, diag::warn_bool_switch_condition) 604 << CondExpr->getSourceRange(); 605 } 606 } 607 608 // Get the bitwidth of the switched-on value before promotions. We must 609 // convert the integer case values to this width before comparison. 610 bool HasDependentValue 611 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 612 unsigned CondWidth 613 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 614 bool CondIsSigned 615 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 616 617 // Accumulate all of the case values in a vector so that we can sort them 618 // and detect duplicates. This vector contains the APInt for the case after 619 // it has been converted to the condition type. 620 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 621 CaseValsTy CaseVals; 622 623 // Keep track of any GNU case ranges we see. The APSInt is the low value. 624 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 625 CaseRangesTy CaseRanges; 626 627 DefaultStmt *TheDefaultStmt = 0; 628 629 bool CaseListIsErroneous = false; 630 631 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 632 SC = SC->getNextSwitchCase()) { 633 634 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 635 if (TheDefaultStmt) { 636 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 637 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 638 639 // FIXME: Remove the default statement from the switch block so that 640 // we'll return a valid AST. This requires recursing down the AST and 641 // finding it, not something we are set up to do right now. For now, 642 // just lop the entire switch stmt out of the AST. 643 CaseListIsErroneous = true; 644 } 645 TheDefaultStmt = DS; 646 647 } else { 648 CaseStmt *CS = cast<CaseStmt>(SC); 649 650 Expr *Lo = CS->getLHS(); 651 652 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 653 HasDependentValue = true; 654 break; 655 } 656 657 llvm::APSInt LoVal; 658 659 if (getLangOpts().CPlusPlus0x) { 660 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 661 // constant expression of the promoted type of the switch condition. 662 ExprResult ConvLo = 663 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); 664 if (ConvLo.isInvalid()) { 665 CaseListIsErroneous = true; 666 continue; 667 } 668 Lo = ConvLo.take(); 669 } else { 670 // We already verified that the expression has a i-c-e value (C99 671 // 6.8.4.2p3) - get that value now. 672 LoVal = Lo->EvaluateKnownConstInt(Context); 673 674 // If the LHS is not the same type as the condition, insert an implicit 675 // cast. 676 Lo = DefaultLvalueConversion(Lo).take(); 677 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 678 } 679 680 // Convert the value to the same width/sign as the condition had prior to 681 // integral promotions. 682 // 683 // FIXME: This causes us to reject valid code: 684 // switch ((char)c) { case 256: case 0: return 0; } 685 // Here we claim there is a duplicated condition value, but there is not. 686 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 687 Lo->getLocStart(), 688 diag::warn_case_value_overflow); 689 690 CS->setLHS(Lo); 691 692 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 693 if (CS->getRHS()) { 694 if (CS->getRHS()->isTypeDependent() || 695 CS->getRHS()->isValueDependent()) { 696 HasDependentValue = true; 697 break; 698 } 699 CaseRanges.push_back(std::make_pair(LoVal, CS)); 700 } else 701 CaseVals.push_back(std::make_pair(LoVal, CS)); 702 } 703 } 704 705 if (!HasDependentValue) { 706 // If we don't have a default statement, check whether the 707 // condition is constant. 708 llvm::APSInt ConstantCondValue; 709 bool HasConstantCond = false; 710 if (!HasDependentValue && !TheDefaultStmt) { 711 HasConstantCond 712 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, 713 Expr::SE_AllowSideEffects); 714 assert(!HasConstantCond || 715 (ConstantCondValue.getBitWidth() == CondWidth && 716 ConstantCondValue.isSigned() == CondIsSigned)); 717 } 718 bool ShouldCheckConstantCond = HasConstantCond; 719 720 // Sort all the scalar case values so we can easily detect duplicates. 721 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 722 723 if (!CaseVals.empty()) { 724 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 725 if (ShouldCheckConstantCond && 726 CaseVals[i].first == ConstantCondValue) 727 ShouldCheckConstantCond = false; 728 729 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 730 // If we have a duplicate, report it. 731 Diag(CaseVals[i].second->getLHS()->getLocStart(), 732 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 733 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 734 diag::note_duplicate_case_prev); 735 // FIXME: We really want to remove the bogus case stmt from the 736 // substmt, but we have no way to do this right now. 737 CaseListIsErroneous = true; 738 } 739 } 740 } 741 742 // Detect duplicate case ranges, which usually don't exist at all in 743 // the first place. 744 if (!CaseRanges.empty()) { 745 // Sort all the case ranges by their low value so we can easily detect 746 // overlaps between ranges. 747 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 748 749 // Scan the ranges, computing the high values and removing empty ranges. 750 std::vector<llvm::APSInt> HiVals; 751 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 752 llvm::APSInt &LoVal = CaseRanges[i].first; 753 CaseStmt *CR = CaseRanges[i].second; 754 Expr *Hi = CR->getRHS(); 755 llvm::APSInt HiVal; 756 757 if (getLangOpts().CPlusPlus0x) { 758 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 759 // constant expression of the promoted type of the switch condition. 760 ExprResult ConvHi = 761 CheckConvertedConstantExpression(Hi, CondType, HiVal, 762 CCEK_CaseValue); 763 if (ConvHi.isInvalid()) { 764 CaseListIsErroneous = true; 765 continue; 766 } 767 Hi = ConvHi.take(); 768 } else { 769 HiVal = Hi->EvaluateKnownConstInt(Context); 770 771 // If the RHS is not the same type as the condition, insert an 772 // implicit cast. 773 Hi = DefaultLvalueConversion(Hi).take(); 774 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 775 } 776 777 // Convert the value to the same width/sign as the condition. 778 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 779 Hi->getLocStart(), 780 diag::warn_case_value_overflow); 781 782 CR->setRHS(Hi); 783 784 // If the low value is bigger than the high value, the case is empty. 785 if (LoVal > HiVal) { 786 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 787 << SourceRange(CR->getLHS()->getLocStart(), 788 Hi->getLocEnd()); 789 CaseRanges.erase(CaseRanges.begin()+i); 790 --i, --e; 791 continue; 792 } 793 794 if (ShouldCheckConstantCond && 795 LoVal <= ConstantCondValue && 796 ConstantCondValue <= HiVal) 797 ShouldCheckConstantCond = false; 798 799 HiVals.push_back(HiVal); 800 } 801 802 // Rescan the ranges, looking for overlap with singleton values and other 803 // ranges. Since the range list is sorted, we only need to compare case 804 // ranges with their neighbors. 805 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 806 llvm::APSInt &CRLo = CaseRanges[i].first; 807 llvm::APSInt &CRHi = HiVals[i]; 808 CaseStmt *CR = CaseRanges[i].second; 809 810 // Check to see whether the case range overlaps with any 811 // singleton cases. 812 CaseStmt *OverlapStmt = 0; 813 llvm::APSInt OverlapVal(32); 814 815 // Find the smallest value >= the lower bound. If I is in the 816 // case range, then we have overlap. 817 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 818 CaseVals.end(), CRLo, 819 CaseCompareFunctor()); 820 if (I != CaseVals.end() && I->first < CRHi) { 821 OverlapVal = I->first; // Found overlap with scalar. 822 OverlapStmt = I->second; 823 } 824 825 // Find the smallest value bigger than the upper bound. 826 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 827 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 828 OverlapVal = (I-1)->first; // Found overlap with scalar. 829 OverlapStmt = (I-1)->second; 830 } 831 832 // Check to see if this case stmt overlaps with the subsequent 833 // case range. 834 if (i && CRLo <= HiVals[i-1]) { 835 OverlapVal = HiVals[i-1]; // Found overlap with range. 836 OverlapStmt = CaseRanges[i-1].second; 837 } 838 839 if (OverlapStmt) { 840 // If we have a duplicate, report it. 841 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 842 << OverlapVal.toString(10); 843 Diag(OverlapStmt->getLHS()->getLocStart(), 844 diag::note_duplicate_case_prev); 845 // FIXME: We really want to remove the bogus case stmt from the 846 // substmt, but we have no way to do this right now. 847 CaseListIsErroneous = true; 848 } 849 } 850 } 851 852 // Complain if we have a constant condition and we didn't find a match. 853 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 854 // TODO: it would be nice if we printed enums as enums, chars as 855 // chars, etc. 856 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 857 << ConstantCondValue.toString(10) 858 << CondExpr->getSourceRange(); 859 } 860 861 // Check to see if switch is over an Enum and handles all of its 862 // values. We only issue a warning if there is not 'default:', but 863 // we still do the analysis to preserve this information in the AST 864 // (which can be used by flow-based analyes). 865 // 866 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 867 868 // If switch has default case, then ignore it. 869 if (!CaseListIsErroneous && !HasConstantCond && ET) { 870 const EnumDecl *ED = ET->getDecl(); 871 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 872 EnumValsTy; 873 EnumValsTy EnumVals; 874 875 // Gather all enum values, set their type and sort them, 876 // allowing easier comparison with CaseVals. 877 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 878 EDI != ED->enumerator_end(); ++EDI) { 879 llvm::APSInt Val = EDI->getInitVal(); 880 AdjustAPSInt(Val, CondWidth, CondIsSigned); 881 EnumVals.push_back(std::make_pair(Val, &*EDI)); 882 } 883 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 884 EnumValsTy::iterator EIend = 885 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 886 887 // See which case values aren't in enum. 888 EnumValsTy::const_iterator EI = EnumVals.begin(); 889 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 890 CI != CaseVals.end(); CI++) { 891 while (EI != EIend && EI->first < CI->first) 892 EI++; 893 if (EI == EIend || EI->first > CI->first) 894 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 895 << CondTypeBeforePromotion; 896 } 897 // See which of case ranges aren't in enum 898 EI = EnumVals.begin(); 899 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 900 RI != CaseRanges.end() && EI != EIend; RI++) { 901 while (EI != EIend && EI->first < RI->first) 902 EI++; 903 904 if (EI == EIend || EI->first != RI->first) { 905 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 906 << CondTypeBeforePromotion; 907 } 908 909 llvm::APSInt Hi = 910 RI->second->getRHS()->EvaluateKnownConstInt(Context); 911 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 912 while (EI != EIend && EI->first < Hi) 913 EI++; 914 if (EI == EIend || EI->first != Hi) 915 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 916 << CondTypeBeforePromotion; 917 } 918 919 // Check which enum vals aren't in switch 920 CaseValsTy::const_iterator CI = CaseVals.begin(); 921 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 922 bool hasCasesNotInSwitch = false; 923 924 SmallVector<DeclarationName,8> UnhandledNames; 925 926 for (EI = EnumVals.begin(); EI != EIend; EI++){ 927 // Drop unneeded case values 928 llvm::APSInt CIVal; 929 while (CI != CaseVals.end() && CI->first < EI->first) 930 CI++; 931 932 if (CI != CaseVals.end() && CI->first == EI->first) 933 continue; 934 935 // Drop unneeded case ranges 936 for (; RI != CaseRanges.end(); RI++) { 937 llvm::APSInt Hi = 938 RI->second->getRHS()->EvaluateKnownConstInt(Context); 939 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 940 if (EI->first <= Hi) 941 break; 942 } 943 944 if (RI == CaseRanges.end() || EI->first < RI->first) { 945 hasCasesNotInSwitch = true; 946 UnhandledNames.push_back(EI->second->getDeclName()); 947 } 948 } 949 950 if (TheDefaultStmt && UnhandledNames.empty()) 951 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); 952 953 // Produce a nice diagnostic if multiple values aren't handled. 954 switch (UnhandledNames.size()) { 955 case 0: break; 956 case 1: 957 Diag(CondExpr->getExprLoc(), TheDefaultStmt 958 ? diag::warn_def_missing_case1 : diag::warn_missing_case1) 959 << UnhandledNames[0]; 960 break; 961 case 2: 962 Diag(CondExpr->getExprLoc(), TheDefaultStmt 963 ? diag::warn_def_missing_case2 : diag::warn_missing_case2) 964 << UnhandledNames[0] << UnhandledNames[1]; 965 break; 966 case 3: 967 Diag(CondExpr->getExprLoc(), TheDefaultStmt 968 ? diag::warn_def_missing_case3 : diag::warn_missing_case3) 969 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 970 break; 971 default: 972 Diag(CondExpr->getExprLoc(), TheDefaultStmt 973 ? diag::warn_def_missing_cases : diag::warn_missing_cases) 974 << (unsigned)UnhandledNames.size() 975 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 976 break; 977 } 978 979 if (!hasCasesNotInSwitch) 980 SS->setAllEnumCasesCovered(); 981 } 982 } 983 984 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, 985 diag::warn_empty_switch_body); 986 987 // FIXME: If the case list was broken is some way, we don't have a good system 988 // to patch it up. Instead, just return the whole substmt as broken. 989 if (CaseListIsErroneous) 990 return StmtError(); 991 992 return Owned(SS); 993} 994 995StmtResult 996Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 997 Decl *CondVar, Stmt *Body) { 998 ExprResult CondResult(Cond.release()); 999 1000 VarDecl *ConditionVar = 0; 1001 if (CondVar) { 1002 ConditionVar = cast<VarDecl>(CondVar); 1003 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 1004 if (CondResult.isInvalid()) 1005 return StmtError(); 1006 } 1007 Expr *ConditionExpr = CondResult.take(); 1008 if (!ConditionExpr) 1009 return StmtError(); 1010 1011 DiagnoseUnusedExprResult(Body); 1012 1013 if (isa<NullStmt>(Body)) 1014 getCurCompoundScope().setHasEmptyLoopBodies(); 1015 1016 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 1017 Body, WhileLoc)); 1018} 1019 1020StmtResult 1021Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 1022 SourceLocation WhileLoc, SourceLocation CondLParen, 1023 Expr *Cond, SourceLocation CondRParen) { 1024 assert(Cond && "ActOnDoStmt(): missing expression"); 1025 1026 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 1027 if (CondResult.isInvalid() || CondResult.isInvalid()) 1028 return StmtError(); 1029 Cond = CondResult.take(); 1030 1031 CheckImplicitConversions(Cond, DoLoc); 1032 CondResult = MaybeCreateExprWithCleanups(Cond); 1033 if (CondResult.isInvalid()) 1034 return StmtError(); 1035 Cond = CondResult.take(); 1036 1037 DiagnoseUnusedExprResult(Body); 1038 1039 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 1040} 1041 1042namespace { 1043 // This visitor will traverse a conditional statement and store all 1044 // the evaluated decls into a vector. Simple is set to true if none 1045 // of the excluded constructs are used. 1046 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { 1047 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1048 llvm::SmallVector<SourceRange, 10> &Ranges; 1049 bool Simple; 1050 PartialDiagnostic &PDiag; 1051public: 1052 typedef EvaluatedExprVisitor<DeclExtractor> Inherited; 1053 1054 DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, 1055 llvm::SmallVector<SourceRange, 10> &Ranges, 1056 PartialDiagnostic &PDiag) : 1057 Inherited(S.Context), 1058 Decls(Decls), 1059 Ranges(Ranges), 1060 Simple(true), 1061 PDiag(PDiag) {} 1062 1063 bool isSimple() { return Simple; } 1064 1065 // Replaces the method in EvaluatedExprVisitor. 1066 void VisitMemberExpr(MemberExpr* E) { 1067 Simple = false; 1068 } 1069 1070 // Any Stmt not whitelisted will cause the condition to be marked complex. 1071 void VisitStmt(Stmt *S) { 1072 Simple = false; 1073 } 1074 1075 void VisitBinaryOperator(BinaryOperator *E) { 1076 Visit(E->getLHS()); 1077 Visit(E->getRHS()); 1078 } 1079 1080 void VisitCastExpr(CastExpr *E) { 1081 Visit(E->getSubExpr()); 1082 } 1083 1084 void VisitUnaryOperator(UnaryOperator *E) { 1085 // Skip checking conditionals with derefernces. 1086 if (E->getOpcode() == UO_Deref) 1087 Simple = false; 1088 else 1089 Visit(E->getSubExpr()); 1090 } 1091 1092 void VisitConditionalOperator(ConditionalOperator *E) { 1093 Visit(E->getCond()); 1094 Visit(E->getTrueExpr()); 1095 Visit(E->getFalseExpr()); 1096 } 1097 1098 void VisitParenExpr(ParenExpr *E) { 1099 Visit(E->getSubExpr()); 1100 } 1101 1102 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { 1103 Visit(E->getOpaqueValue()->getSourceExpr()); 1104 Visit(E->getFalseExpr()); 1105 } 1106 1107 void VisitIntegerLiteral(IntegerLiteral *E) { } 1108 void VisitFloatingLiteral(FloatingLiteral *E) { } 1109 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } 1110 void VisitCharacterLiteral(CharacterLiteral *E) { } 1111 void VisitGNUNullExpr(GNUNullExpr *E) { } 1112 void VisitImaginaryLiteral(ImaginaryLiteral *E) { } 1113 1114 void VisitDeclRefExpr(DeclRefExpr *E) { 1115 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); 1116 if (!VD) return; 1117 1118 Ranges.push_back(E->getSourceRange()); 1119 1120 Decls.insert(VD); 1121 } 1122 1123 }; // end class DeclExtractor 1124 1125 // DeclMatcher checks to see if the decls are used in a non-evauluated 1126 // context. 1127 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { 1128 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1129 bool FoundDecl; 1130 //bool EvalDecl; 1131 1132public: 1133 typedef EvaluatedExprVisitor<DeclMatcher> Inherited; 1134 1135 DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, Stmt *Statement) : 1136 Inherited(S.Context), Decls(Decls), FoundDecl(false) { 1137 if (!Statement) return; 1138 1139 Visit(Statement); 1140 } 1141 1142 void VisitReturnStmt(ReturnStmt *S) { 1143 FoundDecl = true; 1144 } 1145 1146 void VisitBreakStmt(BreakStmt *S) { 1147 FoundDecl = true; 1148 } 1149 1150 void VisitGotoStmt(GotoStmt *S) { 1151 FoundDecl = true; 1152 } 1153 1154 void VisitCastExpr(CastExpr *E) { 1155 if (E->getCastKind() == CK_LValueToRValue) 1156 CheckLValueToRValueCast(E->getSubExpr()); 1157 else 1158 Visit(E->getSubExpr()); 1159 } 1160 1161 void CheckLValueToRValueCast(Expr *E) { 1162 E = E->IgnoreParenImpCasts(); 1163 1164 if (isa<DeclRefExpr>(E)) { 1165 return; 1166 } 1167 1168 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1169 Visit(CO->getCond()); 1170 CheckLValueToRValueCast(CO->getTrueExpr()); 1171 CheckLValueToRValueCast(CO->getFalseExpr()); 1172 return; 1173 } 1174 1175 if (BinaryConditionalOperator *BCO = 1176 dyn_cast<BinaryConditionalOperator>(E)) { 1177 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); 1178 CheckLValueToRValueCast(BCO->getFalseExpr()); 1179 return; 1180 } 1181 1182 Visit(E); 1183 } 1184 1185 void VisitDeclRefExpr(DeclRefExpr *E) { 1186 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) 1187 if (Decls.count(VD)) 1188 FoundDecl = true; 1189 } 1190 1191 bool FoundDeclInUse() { return FoundDecl; } 1192 1193 }; // end class DeclMatcher 1194 1195 void CheckForLoopConditionalStatement(Sema &S, Expr *Second, 1196 Expr *Third, Stmt *Body) { 1197 // Condition is empty 1198 if (!Second) return; 1199 1200 if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body, 1201 Second->getLocStart()) 1202 == DiagnosticsEngine::Ignored) 1203 return; 1204 1205 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); 1206 llvm::SmallPtrSet<VarDecl*, 8> Decls; 1207 llvm::SmallVector<SourceRange, 10> Ranges; 1208 DeclExtractor DE(S, Decls, Ranges, PDiag); 1209 DE.Visit(Second); 1210 1211 // Don't analyze complex conditionals. 1212 if (!DE.isSimple()) return; 1213 1214 // No decls found. 1215 if (Decls.size() == 0) return; 1216 1217 // Don't warn on volatile, static, or global variables. 1218 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1219 E = Decls.end(); 1220 I != E; ++I) 1221 if ((*I)->getType().isVolatileQualified() || 1222 (*I)->hasGlobalStorage()) return; 1223 1224 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || 1225 DeclMatcher(S, Decls, Third).FoundDeclInUse() || 1226 DeclMatcher(S, Decls, Body).FoundDeclInUse()) 1227 return; 1228 1229 // Load decl names into diagnostic. 1230 if (Decls.size() > 4) 1231 PDiag << 0; 1232 else { 1233 PDiag << Decls.size(); 1234 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1235 E = Decls.end(); 1236 I != E; ++I) 1237 PDiag << (*I)->getDeclName(); 1238 } 1239 1240 // Load SourceRanges into diagnostic if there is room. 1241 // Otherwise, load the SourceRange of the conditional expression. 1242 if (Ranges.size() <= PartialDiagnostic::MaxArguments) 1243 for (llvm::SmallVector<SourceRange, 10>::iterator I = Ranges.begin(), 1244 E = Ranges.end(); 1245 I != E; ++I) 1246 PDiag << *I; 1247 else 1248 PDiag << Second->getSourceRange(); 1249 1250 S.Diag(Ranges.begin()->getBegin(), PDiag); 1251 } 1252 1253} // end namespace 1254 1255StmtResult 1256Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1257 Stmt *First, FullExprArg second, Decl *secondVar, 1258 FullExprArg third, 1259 SourceLocation RParenLoc, Stmt *Body) { 1260 if (!getLangOpts().CPlusPlus) { 1261 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 1262 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1263 // declare identifiers for objects having storage class 'auto' or 1264 // 'register'. 1265 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 1266 DI!=DE; ++DI) { 1267 VarDecl *VD = dyn_cast<VarDecl>(*DI); 1268 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 1269 VD = 0; 1270 if (VD == 0) 1271 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 1272 // FIXME: mark decl erroneous! 1273 } 1274 } 1275 } 1276 1277 CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body); 1278 1279 ExprResult SecondResult(second.release()); 1280 VarDecl *ConditionVar = 0; 1281 if (secondVar) { 1282 ConditionVar = cast<VarDecl>(secondVar); 1283 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 1284 if (SecondResult.isInvalid()) 1285 return StmtError(); 1286 } 1287 1288 Expr *Third = third.release().takeAs<Expr>(); 1289 1290 DiagnoseUnusedExprResult(First); 1291 DiagnoseUnusedExprResult(Third); 1292 DiagnoseUnusedExprResult(Body); 1293 1294 if (isa<NullStmt>(Body)) 1295 getCurCompoundScope().setHasEmptyLoopBodies(); 1296 1297 return Owned(new (Context) ForStmt(Context, First, 1298 SecondResult.take(), ConditionVar, 1299 Third, Body, ForLoc, LParenLoc, 1300 RParenLoc)); 1301} 1302 1303/// In an Objective C collection iteration statement: 1304/// for (x in y) 1305/// x can be an arbitrary l-value expression. Bind it up as a 1306/// full-expression. 1307StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1308 // Reduce placeholder expressions here. Note that this rejects the 1309 // use of pseudo-object l-values in this position. 1310 ExprResult result = CheckPlaceholderExpr(E); 1311 if (result.isInvalid()) return StmtError(); 1312 E = result.take(); 1313 1314 CheckImplicitConversions(E); 1315 1316 result = MaybeCreateExprWithCleanups(E); 1317 if (result.isInvalid()) return StmtError(); 1318 1319 return Owned(static_cast<Stmt*>(result.take())); 1320} 1321 1322ExprResult 1323Sema::ActOnObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1324 assert(collection); 1325 1326 // Bail out early if we've got a type-dependent expression. 1327 if (collection->isTypeDependent()) return Owned(collection); 1328 1329 // Perform normal l-value conversion. 1330 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1331 if (result.isInvalid()) 1332 return ExprError(); 1333 collection = result.take(); 1334 1335 // The operand needs to have object-pointer type. 1336 // TODO: should we do a contextual conversion? 1337 const ObjCObjectPointerType *pointerType = 1338 collection->getType()->getAs<ObjCObjectPointerType>(); 1339 if (!pointerType) 1340 return Diag(forLoc, diag::err_collection_expr_type) 1341 << collection->getType() << collection->getSourceRange(); 1342 1343 // Check that the operand provides 1344 // - countByEnumeratingWithState:objects:count: 1345 const ObjCObjectType *objectType = pointerType->getObjectType(); 1346 ObjCInterfaceDecl *iface = objectType->getInterface(); 1347 1348 // If we have a forward-declared type, we can't do this check. 1349 // Under ARC, it is an error not to have a forward-declared class. 1350 if (iface && 1351 RequireCompleteType(forLoc, QualType(objectType, 0), 1352 getLangOpts().ObjCAutoRefCount 1353 ? diag::err_arc_collection_forward 1354 : 0, 1355 collection)) { 1356 // Otherwise, if we have any useful type information, check that 1357 // the type declares the appropriate method. 1358 } else if (iface || !objectType->qual_empty()) { 1359 IdentifierInfo *selectorIdents[] = { 1360 &Context.Idents.get("countByEnumeratingWithState"), 1361 &Context.Idents.get("objects"), 1362 &Context.Idents.get("count") 1363 }; 1364 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1365 1366 ObjCMethodDecl *method = 0; 1367 1368 // If there's an interface, look in both the public and private APIs. 1369 if (iface) { 1370 method = iface->lookupInstanceMethod(selector); 1371 if (!method) method = LookupPrivateInstanceMethod(selector, iface); 1372 } 1373 1374 // Also check protocol qualifiers. 1375 if (!method) 1376 method = LookupMethodInQualifiedType(selector, pointerType, 1377 /*instance*/ true); 1378 1379 // If we didn't find it anywhere, give up. 1380 if (!method) { 1381 Diag(forLoc, diag::warn_collection_expr_type) 1382 << collection->getType() << selector << collection->getSourceRange(); 1383 } 1384 1385 // TODO: check for an incompatible signature? 1386 } 1387 1388 // Wrap up any cleanups in the expression. 1389 return Owned(MaybeCreateExprWithCleanups(collection)); 1390} 1391 1392StmtResult 1393Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1394 SourceLocation LParenLoc, 1395 Stmt *First, Expr *Second, 1396 SourceLocation RParenLoc, Stmt *Body) { 1397 if (First) { 1398 QualType FirstType; 1399 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1400 if (!DS->isSingleDecl()) 1401 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1402 diag::err_toomany_element_decls)); 1403 1404 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1405 FirstType = D->getType(); 1406 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1407 // declare identifiers for objects having storage class 'auto' or 1408 // 'register'. 1409 if (!D->hasLocalStorage()) 1410 return StmtError(Diag(D->getLocation(), 1411 diag::err_non_variable_decl_in_for)); 1412 } else { 1413 Expr *FirstE = cast<Expr>(First); 1414 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1415 return StmtError(Diag(First->getLocStart(), 1416 diag::err_selector_element_not_lvalue) 1417 << First->getSourceRange()); 1418 1419 FirstType = static_cast<Expr*>(First)->getType(); 1420 } 1421 if (!FirstType->isDependentType() && 1422 !FirstType->isObjCObjectPointerType() && 1423 !FirstType->isBlockPointerType()) 1424 Diag(ForLoc, diag::err_selector_element_type) 1425 << FirstType << First->getSourceRange(); 1426 } 1427 1428 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 1429 ForLoc, RParenLoc)); 1430} 1431 1432namespace { 1433 1434enum BeginEndFunction { 1435 BEF_begin, 1436 BEF_end 1437}; 1438 1439/// Build a variable declaration for a for-range statement. 1440static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1441 QualType Type, const char *Name) { 1442 DeclContext *DC = SemaRef.CurContext; 1443 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1444 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1445 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1446 TInfo, SC_Auto, SC_None); 1447 Decl->setImplicit(); 1448 return Decl; 1449} 1450 1451/// Finish building a variable declaration for a for-range statement. 1452/// \return true if an error occurs. 1453static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1454 SourceLocation Loc, int diag) { 1455 // Deduce the type for the iterator variable now rather than leaving it to 1456 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1457 TypeSourceInfo *InitTSI = 0; 1458 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || 1459 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) == 1460 Sema::DAR_Failed) 1461 SemaRef.Diag(Loc, diag) << Init->getType(); 1462 if (!InitTSI) { 1463 Decl->setInvalidDecl(); 1464 return true; 1465 } 1466 Decl->setTypeSourceInfo(InitTSI); 1467 Decl->setType(InitTSI->getType()); 1468 1469 // In ARC, infer lifetime. 1470 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1471 // we're doing the equivalent of fast iteration. 1472 if (SemaRef.getLangOpts().ObjCAutoRefCount && 1473 SemaRef.inferObjCARCLifetime(Decl)) 1474 Decl->setInvalidDecl(); 1475 1476 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1477 /*TypeMayContainAuto=*/false); 1478 SemaRef.FinalizeDeclaration(Decl); 1479 SemaRef.CurContext->addHiddenDecl(Decl); 1480 return false; 1481} 1482 1483/// Produce a note indicating which begin/end function was implicitly called 1484/// by a C++0x for-range statement. This is often not obvious from the code, 1485/// nor from the diagnostics produced when analysing the implicit expressions 1486/// required in a for-range statement. 1487void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1488 BeginEndFunction BEF) { 1489 CallExpr *CE = dyn_cast<CallExpr>(E); 1490 if (!CE) 1491 return; 1492 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1493 if (!D) 1494 return; 1495 SourceLocation Loc = D->getLocation(); 1496 1497 std::string Description; 1498 bool IsTemplate = false; 1499 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1500 Description = SemaRef.getTemplateArgumentBindingsText( 1501 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1502 IsTemplate = true; 1503 } 1504 1505 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1506 << BEF << IsTemplate << Description << E->getType(); 1507} 1508 1509/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1510/// given LookupResult is non-empty, it is assumed to describe a member which 1511/// will be invoked. Otherwise, the function will be found via argument 1512/// dependent lookup. 1513static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1514 SourceLocation Loc, 1515 VarDecl *Decl, 1516 BeginEndFunction BEF, 1517 const DeclarationNameInfo &NameInfo, 1518 LookupResult &MemberLookup, 1519 Expr *Range) { 1520 ExprResult CallExpr; 1521 if (!MemberLookup.empty()) { 1522 ExprResult MemberRef = 1523 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1524 /*IsPtr=*/false, CXXScopeSpec(), 1525 /*TemplateKWLoc=*/SourceLocation(), 1526 /*FirstQualifierInScope=*/0, 1527 MemberLookup, 1528 /*TemplateArgs=*/0); 1529 if (MemberRef.isInvalid()) 1530 return ExprError(); 1531 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1532 Loc, 0); 1533 if (CallExpr.isInvalid()) 1534 return ExprError(); 1535 } else { 1536 UnresolvedSet<0> FoundNames; 1537 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1538 // std is an associated namespace. 1539 UnresolvedLookupExpr *Fn = 1540 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1541 NestedNameSpecifierLoc(), NameInfo, 1542 /*NeedsADL=*/true, /*Overloaded=*/false, 1543 FoundNames.begin(), FoundNames.end(), 1544 /*LookInStdNamespace=*/true); 1545 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1546 0, /*AllowTypoCorrection=*/false); 1547 if (CallExpr.isInvalid()) { 1548 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1549 << Range->getType(); 1550 return ExprError(); 1551 } 1552 } 1553 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1554 diag::err_for_range_iter_deduction_failure)) { 1555 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1556 return ExprError(); 1557 } 1558 return CallExpr; 1559} 1560 1561} 1562 1563/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1564/// 1565/// C++0x [stmt.ranged]: 1566/// A range-based for statement is equivalent to 1567/// 1568/// { 1569/// auto && __range = range-init; 1570/// for ( auto __begin = begin-expr, 1571/// __end = end-expr; 1572/// __begin != __end; 1573/// ++__begin ) { 1574/// for-range-declaration = *__begin; 1575/// statement 1576/// } 1577/// } 1578/// 1579/// The body of the loop is not available yet, since it cannot be analysed until 1580/// we have determined the type of the for-range-declaration. 1581StmtResult 1582Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1583 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1584 SourceLocation RParenLoc) { 1585 if (!First || !Range) 1586 return StmtError(); 1587 1588 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1589 assert(DS && "first part of for range not a decl stmt"); 1590 1591 if (!DS->isSingleDecl()) { 1592 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1593 return StmtError(); 1594 } 1595 if (DS->getSingleDecl()->isInvalidDecl()) 1596 return StmtError(); 1597 1598 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1599 return StmtError(); 1600 1601 // Build auto && __range = range-init 1602 SourceLocation RangeLoc = Range->getLocStart(); 1603 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1604 Context.getAutoRRefDeductType(), 1605 "__range"); 1606 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1607 diag::err_for_range_deduction_failure)) 1608 return StmtError(); 1609 1610 // Claim the type doesn't contain auto: we've already done the checking. 1611 DeclGroupPtrTy RangeGroup = 1612 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1613 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1614 if (RangeDecl.isInvalid()) 1615 return StmtError(); 1616 1617 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1618 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1619 RParenLoc); 1620} 1621 1622/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1623StmtResult 1624Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1625 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1626 Expr *Inc, Stmt *LoopVarDecl, 1627 SourceLocation RParenLoc) { 1628 Scope *S = getCurScope(); 1629 1630 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1631 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1632 QualType RangeVarType = RangeVar->getType(); 1633 1634 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1635 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1636 1637 StmtResult BeginEndDecl = BeginEnd; 1638 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1639 1640 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1641 SourceLocation RangeLoc = RangeVar->getLocation(); 1642 1643 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); 1644 1645 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1646 VK_LValue, ColonLoc); 1647 if (BeginRangeRef.isInvalid()) 1648 return StmtError(); 1649 1650 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1651 VK_LValue, ColonLoc); 1652 if (EndRangeRef.isInvalid()) 1653 return StmtError(); 1654 1655 QualType AutoType = Context.getAutoDeductType(); 1656 Expr *Range = RangeVar->getInit(); 1657 if (!Range) 1658 return StmtError(); 1659 QualType RangeType = Range->getType(); 1660 1661 if (RequireCompleteType(RangeLoc, RangeType, 1662 diag::err_for_range_incomplete_type)) 1663 return StmtError(); 1664 1665 // Build auto __begin = begin-expr, __end = end-expr. 1666 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1667 "__begin"); 1668 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1669 "__end"); 1670 1671 // Build begin-expr and end-expr and attach to __begin and __end variables. 1672 ExprResult BeginExpr, EndExpr; 1673 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1674 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1675 // __range + __bound, respectively, where __bound is the array bound. If 1676 // _RangeT is an array of unknown size or an array of incomplete type, 1677 // the program is ill-formed; 1678 1679 // begin-expr is __range. 1680 BeginExpr = BeginRangeRef; 1681 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, 1682 diag::err_for_range_iter_deduction_failure)) { 1683 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1684 return StmtError(); 1685 } 1686 1687 // Find the array bound. 1688 ExprResult BoundExpr; 1689 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1690 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1691 Context.getPointerDiffType(), 1692 RangeLoc)); 1693 else if (const VariableArrayType *VAT = 1694 dyn_cast<VariableArrayType>(UnqAT)) 1695 BoundExpr = VAT->getSizeExpr(); 1696 else { 1697 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1698 // UnqAT is not incomplete and Range is not type-dependent. 1699 llvm_unreachable("Unexpected array type in for-range"); 1700 } 1701 1702 // end-expr is __range + __bound. 1703 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), 1704 BoundExpr.get()); 1705 if (EndExpr.isInvalid()) 1706 return StmtError(); 1707 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1708 diag::err_for_range_iter_deduction_failure)) { 1709 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1710 return StmtError(); 1711 } 1712 } else { 1713 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1714 ColonLoc); 1715 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1716 ColonLoc); 1717 1718 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1719 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1720 1721 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1722 // - if _RangeT is a class type, the unqualified-ids begin and end are 1723 // looked up in the scope of class _RangeT as if by class member access 1724 // lookup (3.4.5), and if either (or both) finds at least one 1725 // declaration, begin-expr and end-expr are __range.begin() and 1726 // __range.end(), respectively; 1727 LookupQualifiedName(BeginMemberLookup, D); 1728 LookupQualifiedName(EndMemberLookup, D); 1729 1730 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1731 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1732 << RangeType << BeginMemberLookup.empty(); 1733 return StmtError(); 1734 } 1735 } else { 1736 // - otherwise, begin-expr and end-expr are begin(__range) and 1737 // end(__range), respectively, where begin and end are looked up with 1738 // argument-dependent lookup (3.4.2). For the purposes of this name 1739 // lookup, namespace std is an associated namespace. 1740 } 1741 1742 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1743 BEF_begin, BeginNameInfo, 1744 BeginMemberLookup, 1745 BeginRangeRef.get()); 1746 if (BeginExpr.isInvalid()) 1747 return StmtError(); 1748 1749 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1750 BEF_end, EndNameInfo, 1751 EndMemberLookup, EndRangeRef.get()); 1752 if (EndExpr.isInvalid()) 1753 return StmtError(); 1754 } 1755 1756 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1757 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1758 if (!Context.hasSameType(BeginType, EndType)) { 1759 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1760 << BeginType << EndType; 1761 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1762 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1763 } 1764 1765 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1766 // Claim the type doesn't contain auto: we've already done the checking. 1767 DeclGroupPtrTy BeginEndGroup = 1768 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1769 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1770 1771 const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); 1772 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1773 VK_LValue, ColonLoc); 1774 if (BeginRef.isInvalid()) 1775 return StmtError(); 1776 1777 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1778 VK_LValue, ColonLoc); 1779 if (EndRef.isInvalid()) 1780 return StmtError(); 1781 1782 // Build and check __begin != __end expression. 1783 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1784 BeginRef.get(), EndRef.get()); 1785 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1786 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1787 if (NotEqExpr.isInvalid()) { 1788 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1789 if (!Context.hasSameType(BeginType, EndType)) 1790 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1791 return StmtError(); 1792 } 1793 1794 // Build and check ++__begin expression. 1795 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1796 VK_LValue, ColonLoc); 1797 if (BeginRef.isInvalid()) 1798 return StmtError(); 1799 1800 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1801 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1802 if (IncrExpr.isInvalid()) { 1803 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1804 return StmtError(); 1805 } 1806 1807 // Build and check *__begin expression. 1808 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1809 VK_LValue, ColonLoc); 1810 if (BeginRef.isInvalid()) 1811 return StmtError(); 1812 1813 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1814 if (DerefExpr.isInvalid()) { 1815 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1816 return StmtError(); 1817 } 1818 1819 // Attach *__begin as initializer for VD. 1820 if (!LoopVar->isInvalidDecl()) { 1821 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1822 /*TypeMayContainAuto=*/true); 1823 if (LoopVar->isInvalidDecl()) 1824 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1825 } 1826 } else { 1827 // The range is implicitly used as a placeholder when it is dependent. 1828 RangeVar->setUsed(); 1829 } 1830 1831 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1832 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1833 NotEqExpr.take(), IncrExpr.take(), 1834 LoopVarDS, /*Body=*/0, ForLoc, 1835 ColonLoc, RParenLoc)); 1836} 1837 1838/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1839/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1840/// body cannot be performed until after the type of the range variable is 1841/// determined. 1842StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1843 if (!S || !B) 1844 return StmtError(); 1845 1846 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); 1847 ForStmt->setBody(B); 1848 1849 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, 1850 diag::warn_empty_range_based_for_body); 1851 1852 return S; 1853} 1854 1855StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1856 SourceLocation LabelLoc, 1857 LabelDecl *TheDecl) { 1858 getCurFunction()->setHasBranchIntoScope(); 1859 TheDecl->setUsed(); 1860 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1861} 1862 1863StmtResult 1864Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1865 Expr *E) { 1866 // Convert operand to void* 1867 if (!E->isTypeDependent()) { 1868 QualType ETy = E->getType(); 1869 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1870 ExprResult ExprRes = Owned(E); 1871 AssignConvertType ConvTy = 1872 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1873 if (ExprRes.isInvalid()) 1874 return StmtError(); 1875 E = ExprRes.take(); 1876 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1877 return StmtError(); 1878 E = MaybeCreateExprWithCleanups(E); 1879 } 1880 1881 getCurFunction()->setHasIndirectGoto(); 1882 1883 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1884} 1885 1886StmtResult 1887Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1888 Scope *S = CurScope->getContinueParent(); 1889 if (!S) { 1890 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1891 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1892 } 1893 1894 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1895} 1896 1897StmtResult 1898Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1899 Scope *S = CurScope->getBreakParent(); 1900 if (!S) { 1901 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1902 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1903 } 1904 1905 return Owned(new (Context) BreakStmt(BreakLoc)); 1906} 1907 1908/// \brief Determine whether the given expression is a candidate for 1909/// copy elision in either a return statement or a throw expression. 1910/// 1911/// \param ReturnType If we're determining the copy elision candidate for 1912/// a return statement, this is the return type of the function. If we're 1913/// determining the copy elision candidate for a throw expression, this will 1914/// be a NULL type. 1915/// 1916/// \param E The expression being returned from the function or block, or 1917/// being thrown. 1918/// 1919/// \param AllowFunctionParameter Whether we allow function parameters to 1920/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1921/// we re-use this logic to determine whether we should try to move as part of 1922/// a return or throw (which does allow function parameters). 1923/// 1924/// \returns The NRVO candidate variable, if the return statement may use the 1925/// NRVO, or NULL if there is no such candidate. 1926const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1927 Expr *E, 1928 bool AllowFunctionParameter) { 1929 QualType ExprType = E->getType(); 1930 // - in a return statement in a function with ... 1931 // ... a class return type ... 1932 if (!ReturnType.isNull()) { 1933 if (!ReturnType->isRecordType()) 1934 return 0; 1935 // ... the same cv-unqualified type as the function return type ... 1936 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1937 return 0; 1938 } 1939 1940 // ... the expression is the name of a non-volatile automatic object 1941 // (other than a function or catch-clause parameter)) ... 1942 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1943 if (!DR) 1944 return 0; 1945 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1946 if (!VD) 1947 return 0; 1948 1949 // ...object (other than a function or catch-clause parameter)... 1950 if (VD->getKind() != Decl::Var && 1951 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) 1952 return 0; 1953 if (VD->isExceptionVariable()) return 0; 1954 1955 // ...automatic... 1956 if (!VD->hasLocalStorage()) return 0; 1957 1958 // ...non-volatile... 1959 if (VD->getType().isVolatileQualified()) return 0; 1960 if (VD->getType()->isReferenceType()) return 0; 1961 1962 // __block variables can't be allocated in a way that permits NRVO. 1963 if (VD->hasAttr<BlocksAttr>()) return 0; 1964 1965 // Variables with higher required alignment than their type's ABI 1966 // alignment cannot use NRVO. 1967 if (VD->hasAttr<AlignedAttr>() && 1968 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) 1969 return 0; 1970 1971 return VD; 1972} 1973 1974/// \brief Perform the initialization of a potentially-movable value, which 1975/// is the result of return value. 1976/// 1977/// This routine implements C++0x [class.copy]p33, which attempts to treat 1978/// returned lvalues as rvalues in certain cases (to prefer move construction), 1979/// then falls back to treating them as lvalues if that failed. 1980ExprResult 1981Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1982 const VarDecl *NRVOCandidate, 1983 QualType ResultType, 1984 Expr *Value, 1985 bool AllowNRVO) { 1986 // C++0x [class.copy]p33: 1987 // When the criteria for elision of a copy operation are met or would 1988 // be met save for the fact that the source object is a function 1989 // parameter, and the object to be copied is designated by an lvalue, 1990 // overload resolution to select the constructor for the copy is first 1991 // performed as if the object were designated by an rvalue. 1992 ExprResult Res = ExprError(); 1993 if (AllowNRVO && 1994 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 1995 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1996 Value->getType(), CK_LValueToRValue, 1997 Value, VK_XValue); 1998 1999 Expr *InitExpr = &AsRvalue; 2000 InitializationKind Kind 2001 = InitializationKind::CreateCopy(Value->getLocStart(), 2002 Value->getLocStart()); 2003 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 2004 2005 // [...] If overload resolution fails, or if the type of the first 2006 // parameter of the selected constructor is not an rvalue reference 2007 // to the object's type (possibly cv-qualified), overload resolution 2008 // is performed again, considering the object as an lvalue. 2009 if (Seq) { 2010 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 2011 StepEnd = Seq.step_end(); 2012 Step != StepEnd; ++Step) { 2013 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 2014 continue; 2015 2016 CXXConstructorDecl *Constructor 2017 = cast<CXXConstructorDecl>(Step->Function.Function); 2018 2019 const RValueReferenceType *RRefType 2020 = Constructor->getParamDecl(0)->getType() 2021 ->getAs<RValueReferenceType>(); 2022 2023 // If we don't meet the criteria, break out now. 2024 if (!RRefType || 2025 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 2026 Context.getTypeDeclType(Constructor->getParent()))) 2027 break; 2028 2029 // Promote "AsRvalue" to the heap, since we now need this 2030 // expression node to persist. 2031 Value = ImplicitCastExpr::Create(Context, Value->getType(), 2032 CK_LValueToRValue, Value, 0, 2033 VK_XValue); 2034 2035 // Complete type-checking the initialization of the return type 2036 // using the constructor we found. 2037 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 2038 } 2039 } 2040 } 2041 2042 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 2043 // above, or overload resolution failed. Either way, we need to try 2044 // (again) now with the return value expression as written. 2045 if (Res.isInvalid()) 2046 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 2047 2048 return Res; 2049} 2050 2051/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements 2052/// for capturing scopes. 2053/// 2054StmtResult 2055Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2056 // If this is the first return we've seen, infer the return type. 2057 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those 2058 // rules which allows multiple return statements. 2059 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); 2060 if (CurCap->HasImplicitReturnType) { 2061 QualType ReturnT; 2062 if (RetValExp && !isa<InitListExpr>(RetValExp)) { 2063 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 2064 if (Result.isInvalid()) 2065 return StmtError(); 2066 RetValExp = Result.take(); 2067 2068 if (!RetValExp->isTypeDependent()) 2069 ReturnT = RetValExp->getType(); 2070 else 2071 ReturnT = Context.DependentTy; 2072 } else { 2073 if (RetValExp) { 2074 // C++11 [expr.lambda.prim]p4 bans inferring the result from an 2075 // initializer list, because it is not an expression (even 2076 // though we represent it as one). We still deduce 'void'. 2077 Diag(ReturnLoc, diag::err_lambda_return_init_list) 2078 << RetValExp->getSourceRange(); 2079 } 2080 2081 ReturnT = Context.VoidTy; 2082 } 2083 // We require the return types to strictly match here. 2084 if (!CurCap->ReturnType.isNull() && 2085 !CurCap->ReturnType->isDependentType() && 2086 !ReturnT->isDependentType() && 2087 !Context.hasSameType(ReturnT, CurCap->ReturnType)) { 2088 Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible) 2089 << ReturnT << CurCap->ReturnType 2090 << (getCurLambda() != 0); 2091 return StmtError(); 2092 } 2093 CurCap->ReturnType = ReturnT; 2094 } 2095 QualType FnRetType = CurCap->ReturnType; 2096 assert(!FnRetType.isNull()); 2097 2098 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { 2099 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 2100 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); 2101 return StmtError(); 2102 } 2103 } else { 2104 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap); 2105 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){ 2106 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); 2107 return StmtError(); 2108 } 2109 } 2110 2111 // Otherwise, verify that this result type matches the previous one. We are 2112 // pickier with blocks than for normal functions because we don't have GCC 2113 // compatibility to worry about here. 2114 const VarDecl *NRVOCandidate = 0; 2115 if (FnRetType->isDependentType()) { 2116 // Delay processing for now. TODO: there are lots of dependent 2117 // types we can conclusively prove aren't void. 2118 } else if (FnRetType->isVoidType()) { 2119 if (RetValExp && !isa<InitListExpr>(RetValExp) && 2120 !(getLangOpts().CPlusPlus && 2121 (RetValExp->isTypeDependent() || 2122 RetValExp->getType()->isVoidType()))) { 2123 if (!getLangOpts().CPlusPlus && 2124 RetValExp->getType()->isVoidType()) 2125 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; 2126 else { 2127 Diag(ReturnLoc, diag::err_return_block_has_expr); 2128 RetValExp = 0; 2129 } 2130 } 2131 } else if (!RetValExp) { 2132 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 2133 } else if (!RetValExp->isTypeDependent()) { 2134 // we have a non-void block with an expression, continue checking 2135 2136 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2137 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2138 // function return. 2139 2140 // In C++ the return statement is handled via a copy initialization. 2141 // the C version of which boils down to CheckSingleAssignmentConstraints. 2142 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2143 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2144 FnRetType, 2145 NRVOCandidate != 0); 2146 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2147 FnRetType, RetValExp); 2148 if (Res.isInvalid()) { 2149 // FIXME: Cleanup temporaries here, anyway? 2150 return StmtError(); 2151 } 2152 RetValExp = Res.take(); 2153 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2154 } 2155 2156 if (RetValExp) { 2157 CheckImplicitConversions(RetValExp, ReturnLoc); 2158 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2159 } 2160 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 2161 NRVOCandidate); 2162 2163 // If we need to check for the named return value optimization, save the 2164 // return statement in our scope for later processing. 2165 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2166 !CurContext->isDependentContext()) 2167 FunctionScopes.back()->Returns.push_back(Result); 2168 2169 return Owned(Result); 2170} 2171 2172StmtResult 2173Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2174 // Check for unexpanded parameter packs. 2175 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 2176 return StmtError(); 2177 2178 if (isa<CapturingScopeInfo>(getCurFunction())) 2179 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); 2180 2181 QualType FnRetType; 2182 QualType RelatedRetType; 2183 if (const FunctionDecl *FD = getCurFunctionDecl()) { 2184 FnRetType = FD->getResultType(); 2185 if (FD->hasAttr<NoReturnAttr>() || 2186 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 2187 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 2188 << FD->getDeclName(); 2189 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2190 FnRetType = MD->getResultType(); 2191 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 2192 // In the implementation of a method with a related return type, the 2193 // type used to type-check the validity of return statements within the 2194 // method body is a pointer to the type of the class being implemented. 2195 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 2196 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); 2197 } 2198 } else // If we don't have a function/method context, bail. 2199 return StmtError(); 2200 2201 ReturnStmt *Result = 0; 2202 if (FnRetType->isVoidType()) { 2203 if (RetValExp) { 2204 if (isa<InitListExpr>(RetValExp)) { 2205 // We simply never allow init lists as the return value of void 2206 // functions. This is compatible because this was never allowed before, 2207 // so there's no legacy code to deal with. 2208 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2209 int FunctionKind = 0; 2210 if (isa<ObjCMethodDecl>(CurDecl)) 2211 FunctionKind = 1; 2212 else if (isa<CXXConstructorDecl>(CurDecl)) 2213 FunctionKind = 2; 2214 else if (isa<CXXDestructorDecl>(CurDecl)) 2215 FunctionKind = 3; 2216 2217 Diag(ReturnLoc, diag::err_return_init_list) 2218 << CurDecl->getDeclName() << FunctionKind 2219 << RetValExp->getSourceRange(); 2220 2221 // Drop the expression. 2222 RetValExp = 0; 2223 } else if (!RetValExp->isTypeDependent()) { 2224 // C99 6.8.6.4p1 (ext_ since GCC warns) 2225 unsigned D = diag::ext_return_has_expr; 2226 if (RetValExp->getType()->isVoidType()) 2227 D = diag::ext_return_has_void_expr; 2228 else { 2229 ExprResult Result = Owned(RetValExp); 2230 Result = IgnoredValueConversions(Result.take()); 2231 if (Result.isInvalid()) 2232 return StmtError(); 2233 RetValExp = Result.take(); 2234 RetValExp = ImpCastExprToType(RetValExp, 2235 Context.VoidTy, CK_ToVoid).take(); 2236 } 2237 2238 // return (some void expression); is legal in C++. 2239 if (D != diag::ext_return_has_void_expr || 2240 !getLangOpts().CPlusPlus) { 2241 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2242 2243 int FunctionKind = 0; 2244 if (isa<ObjCMethodDecl>(CurDecl)) 2245 FunctionKind = 1; 2246 else if (isa<CXXConstructorDecl>(CurDecl)) 2247 FunctionKind = 2; 2248 else if (isa<CXXDestructorDecl>(CurDecl)) 2249 FunctionKind = 3; 2250 2251 Diag(ReturnLoc, D) 2252 << CurDecl->getDeclName() << FunctionKind 2253 << RetValExp->getSourceRange(); 2254 } 2255 } 2256 2257 if (RetValExp) { 2258 CheckImplicitConversions(RetValExp, ReturnLoc); 2259 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2260 } 2261 } 2262 2263 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 2264 } else if (!RetValExp && !FnRetType->isDependentType()) { 2265 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 2266 // C99 6.8.6.4p1 (ext_ since GCC warns) 2267 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; 2268 2269 if (FunctionDecl *FD = getCurFunctionDecl()) 2270 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 2271 else 2272 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 2273 Result = new (Context) ReturnStmt(ReturnLoc); 2274 } else { 2275 const VarDecl *NRVOCandidate = 0; 2276 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 2277 // we have a non-void function with an expression, continue checking 2278 2279 if (!RelatedRetType.isNull()) { 2280 // If we have a related result type, perform an extra conversion here. 2281 // FIXME: The diagnostics here don't really describe what is happening. 2282 InitializedEntity Entity = 2283 InitializedEntity::InitializeTemporary(RelatedRetType); 2284 2285 ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), 2286 RetValExp); 2287 if (Res.isInvalid()) { 2288 // FIXME: Cleanup temporaries here, anyway? 2289 return StmtError(); 2290 } 2291 RetValExp = Res.takeAs<Expr>(); 2292 } 2293 2294 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2295 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2296 // function return. 2297 2298 // In C++ the return statement is handled via a copy initialization, 2299 // the C version of which boils down to CheckSingleAssignmentConstraints. 2300 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2301 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2302 FnRetType, 2303 NRVOCandidate != 0); 2304 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2305 FnRetType, RetValExp); 2306 if (Res.isInvalid()) { 2307 // FIXME: Cleanup temporaries here, anyway? 2308 return StmtError(); 2309 } 2310 2311 RetValExp = Res.takeAs<Expr>(); 2312 if (RetValExp) 2313 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2314 } 2315 2316 if (RetValExp) { 2317 CheckImplicitConversions(RetValExp, ReturnLoc); 2318 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2319 } 2320 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 2321 } 2322 2323 // If we need to check for the named return value optimization, save the 2324 // return statement in our scope for later processing. 2325 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2326 !CurContext->isDependentContext()) 2327 FunctionScopes.back()->Returns.push_back(Result); 2328 2329 return Owned(Result); 2330} 2331 2332/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 2333/// ignore "noop" casts in places where an lvalue is required by an inline asm. 2334/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 2335/// provide a strong guidance to not use it. 2336/// 2337/// This method checks to see if the argument is an acceptable l-value and 2338/// returns false if it is a case we can handle. 2339static bool CheckAsmLValue(const Expr *E, Sema &S) { 2340 // Type dependent expressions will be checked during instantiation. 2341 if (E->isTypeDependent()) 2342 return false; 2343 2344 if (E->isLValue()) 2345 return false; // Cool, this is an lvalue. 2346 2347 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 2348 // are supposed to allow. 2349 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 2350 if (E != E2 && E2->isLValue()) { 2351 if (!S.getLangOpts().HeinousExtensions) 2352 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 2353 << E->getSourceRange(); 2354 else 2355 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 2356 << E->getSourceRange(); 2357 // Accept, even if we emitted an error diagnostic. 2358 return false; 2359 } 2360 2361 // None of the above, just randomly invalid non-lvalue. 2362 return true; 2363} 2364 2365/// isOperandMentioned - Return true if the specified operand # is mentioned 2366/// anywhere in the decomposed asm string. 2367static bool isOperandMentioned(unsigned OpNo, 2368 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 2369 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 2370 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 2371 if (!Piece.isOperand()) continue; 2372 2373 // If this is a reference to the input and if the input was the smaller 2374 // one, then we have to reject this asm. 2375 if (Piece.getOperandNo() == OpNo) 2376 return true; 2377 } 2378 2379 return false; 2380} 2381 2382StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 2383 bool IsVolatile, unsigned NumOutputs, 2384 unsigned NumInputs, IdentifierInfo **Names, 2385 MultiExprArg constraints, MultiExprArg exprs, 2386 Expr *asmString, MultiExprArg clobbers, 2387 SourceLocation RParenLoc, bool MSAsm) { 2388 unsigned NumClobbers = clobbers.size(); 2389 StringLiteral **Constraints = 2390 reinterpret_cast<StringLiteral**>(constraints.get()); 2391 Expr **Exprs = exprs.get(); 2392 StringLiteral *AsmString = cast<StringLiteral>(asmString); 2393 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 2394 2395 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2396 2397 // The parser verifies that there is a string literal here. 2398 if (!AsmString->isAscii()) 2399 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2400 << AsmString->getSourceRange()); 2401 2402 for (unsigned i = 0; i != NumOutputs; i++) { 2403 StringLiteral *Literal = Constraints[i]; 2404 if (!Literal->isAscii()) 2405 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2406 << Literal->getSourceRange()); 2407 2408 StringRef OutputName; 2409 if (Names[i]) 2410 OutputName = Names[i]->getName(); 2411 2412 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2413 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2414 return StmtError(Diag(Literal->getLocStart(), 2415 diag::err_asm_invalid_output_constraint) 2416 << Info.getConstraintStr()); 2417 2418 // Check that the output exprs are valid lvalues. 2419 Expr *OutputExpr = Exprs[i]; 2420 if (CheckAsmLValue(OutputExpr, *this)) { 2421 return StmtError(Diag(OutputExpr->getLocStart(), 2422 diag::err_asm_invalid_lvalue_in_output) 2423 << OutputExpr->getSourceRange()); 2424 } 2425 2426 OutputConstraintInfos.push_back(Info); 2427 } 2428 2429 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2430 2431 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2432 StringLiteral *Literal = Constraints[i]; 2433 if (!Literal->isAscii()) 2434 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2435 << Literal->getSourceRange()); 2436 2437 StringRef InputName; 2438 if (Names[i]) 2439 InputName = Names[i]->getName(); 2440 2441 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2442 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2443 NumOutputs, Info)) { 2444 return StmtError(Diag(Literal->getLocStart(), 2445 diag::err_asm_invalid_input_constraint) 2446 << Info.getConstraintStr()); 2447 } 2448 2449 Expr *InputExpr = Exprs[i]; 2450 2451 // Only allow void types for memory constraints. 2452 if (Info.allowsMemory() && !Info.allowsRegister()) { 2453 if (CheckAsmLValue(InputExpr, *this)) 2454 return StmtError(Diag(InputExpr->getLocStart(), 2455 diag::err_asm_invalid_lvalue_in_input) 2456 << Info.getConstraintStr() 2457 << InputExpr->getSourceRange()); 2458 } 2459 2460 if (Info.allowsRegister()) { 2461 if (InputExpr->getType()->isVoidType()) { 2462 return StmtError(Diag(InputExpr->getLocStart(), 2463 diag::err_asm_invalid_type_in_input) 2464 << InputExpr->getType() << Info.getConstraintStr() 2465 << InputExpr->getSourceRange()); 2466 } 2467 } 2468 2469 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2470 if (Result.isInvalid()) 2471 return StmtError(); 2472 2473 Exprs[i] = Result.take(); 2474 InputConstraintInfos.push_back(Info); 2475 } 2476 2477 // Check that the clobbers are valid. 2478 for (unsigned i = 0; i != NumClobbers; i++) { 2479 StringLiteral *Literal = Clobbers[i]; 2480 if (!Literal->isAscii()) 2481 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2482 << Literal->getSourceRange()); 2483 2484 StringRef Clobber = Literal->getString(); 2485 2486 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2487 return StmtError(Diag(Literal->getLocStart(), 2488 diag::err_asm_unknown_register_name) << Clobber); 2489 } 2490 2491 AsmStmt *NS = 2492 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2493 NumOutputs, NumInputs, Names, Constraints, Exprs, 2494 AsmString, NumClobbers, Clobbers, RParenLoc); 2495 // Validate the asm string, ensuring it makes sense given the operands we 2496 // have. 2497 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2498 unsigned DiagOffs; 2499 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2500 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2501 << AsmString->getSourceRange(); 2502 return StmtError(); 2503 } 2504 2505 // Validate tied input operands for type mismatches. 2506 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2507 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2508 2509 // If this is a tied constraint, verify that the output and input have 2510 // either exactly the same type, or that they are int/ptr operands with the 2511 // same size (int/long, int*/long, are ok etc). 2512 if (!Info.hasTiedOperand()) continue; 2513 2514 unsigned TiedTo = Info.getTiedOperand(); 2515 unsigned InputOpNo = i+NumOutputs; 2516 Expr *OutputExpr = Exprs[TiedTo]; 2517 Expr *InputExpr = Exprs[InputOpNo]; 2518 2519 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) 2520 continue; 2521 2522 QualType InTy = InputExpr->getType(); 2523 QualType OutTy = OutputExpr->getType(); 2524 if (Context.hasSameType(InTy, OutTy)) 2525 continue; // All types can be tied to themselves. 2526 2527 // Decide if the input and output are in the same domain (integer/ptr or 2528 // floating point. 2529 enum AsmDomain { 2530 AD_Int, AD_FP, AD_Other 2531 } InputDomain, OutputDomain; 2532 2533 if (InTy->isIntegerType() || InTy->isPointerType()) 2534 InputDomain = AD_Int; 2535 else if (InTy->isRealFloatingType()) 2536 InputDomain = AD_FP; 2537 else 2538 InputDomain = AD_Other; 2539 2540 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2541 OutputDomain = AD_Int; 2542 else if (OutTy->isRealFloatingType()) 2543 OutputDomain = AD_FP; 2544 else 2545 OutputDomain = AD_Other; 2546 2547 // They are ok if they are the same size and in the same domain. This 2548 // allows tying things like: 2549 // void* to int* 2550 // void* to int if they are the same size. 2551 // double to long double if they are the same size. 2552 // 2553 uint64_t OutSize = Context.getTypeSize(OutTy); 2554 uint64_t InSize = Context.getTypeSize(InTy); 2555 if (OutSize == InSize && InputDomain == OutputDomain && 2556 InputDomain != AD_Other) 2557 continue; 2558 2559 // If the smaller input/output operand is not mentioned in the asm string, 2560 // then we can promote the smaller one to a larger input and the asm string 2561 // won't notice. 2562 bool SmallerValueMentioned = false; 2563 2564 // If this is a reference to the input and if the input was the smaller 2565 // one, then we have to reject this asm. 2566 if (isOperandMentioned(InputOpNo, Pieces)) { 2567 // This is a use in the asm string of the smaller operand. Since we 2568 // codegen this by promoting to a wider value, the asm will get printed 2569 // "wrong". 2570 SmallerValueMentioned |= InSize < OutSize; 2571 } 2572 if (isOperandMentioned(TiedTo, Pieces)) { 2573 // If this is a reference to the output, and if the output is the larger 2574 // value, then it's ok because we'll promote the input to the larger type. 2575 SmallerValueMentioned |= OutSize < InSize; 2576 } 2577 2578 // If the smaller value wasn't mentioned in the asm string, and if the 2579 // output was a register, just extend the shorter one to the size of the 2580 // larger one. 2581 if (!SmallerValueMentioned && InputDomain != AD_Other && 2582 OutputConstraintInfos[TiedTo].allowsRegister()) 2583 continue; 2584 2585 // Either both of the operands were mentioned or the smaller one was 2586 // mentioned. One more special case that we'll allow: if the tied input is 2587 // integer, unmentioned, and is a constant, then we'll allow truncating it 2588 // down to the size of the destination. 2589 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2590 !isOperandMentioned(InputOpNo, Pieces) && 2591 InputExpr->isEvaluatable(Context)) { 2592 CastKind castKind = 2593 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2594 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2595 Exprs[InputOpNo] = InputExpr; 2596 NS->setInputExpr(i, InputExpr); 2597 continue; 2598 } 2599 2600 Diag(InputExpr->getLocStart(), 2601 diag::err_asm_tying_incompatible_types) 2602 << InTy << OutTy << OutputExpr->getSourceRange() 2603 << InputExpr->getSourceRange(); 2604 return StmtError(); 2605 } 2606 2607 return Owned(NS); 2608} 2609 2610StmtResult 2611Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2612 SourceLocation RParen, Decl *Parm, 2613 Stmt *Body) { 2614 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2615 if (Var && Var->isInvalidDecl()) 2616 return StmtError(); 2617 2618 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2619} 2620 2621StmtResult 2622Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2623 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2624} 2625 2626StmtResult 2627Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2628 MultiStmtArg CatchStmts, Stmt *Finally) { 2629 if (!getLangOpts().ObjCExceptions) 2630 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2631 2632 getCurFunction()->setHasBranchProtectedScope(); 2633 unsigned NumCatchStmts = CatchStmts.size(); 2634 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2635 CatchStmts.release(), 2636 NumCatchStmts, 2637 Finally)); 2638} 2639 2640StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2641 Expr *Throw) { 2642 if (Throw) { 2643 Throw = MaybeCreateExprWithCleanups(Throw); 2644 ExprResult Result = DefaultLvalueConversion(Throw); 2645 if (Result.isInvalid()) 2646 return StmtError(); 2647 2648 Throw = Result.take(); 2649 QualType ThrowType = Throw->getType(); 2650 // Make sure the expression type is an ObjC pointer or "void *". 2651 if (!ThrowType->isDependentType() && 2652 !ThrowType->isObjCObjectPointerType()) { 2653 const PointerType *PT = ThrowType->getAs<PointerType>(); 2654 if (!PT || !PT->getPointeeType()->isVoidType()) 2655 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2656 << Throw->getType() << Throw->getSourceRange()); 2657 } 2658 } 2659 2660 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2661} 2662 2663StmtResult 2664Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2665 Scope *CurScope) { 2666 if (!getLangOpts().ObjCExceptions) 2667 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2668 2669 if (!Throw) { 2670 // @throw without an expression designates a rethrow (which much occur 2671 // in the context of an @catch clause). 2672 Scope *AtCatchParent = CurScope; 2673 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2674 AtCatchParent = AtCatchParent->getParent(); 2675 if (!AtCatchParent) 2676 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2677 } 2678 2679 return BuildObjCAtThrowStmt(AtLoc, Throw); 2680} 2681 2682ExprResult 2683Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2684 ExprResult result = DefaultLvalueConversion(operand); 2685 if (result.isInvalid()) 2686 return ExprError(); 2687 operand = result.take(); 2688 2689 // Make sure the expression type is an ObjC pointer or "void *". 2690 QualType type = operand->getType(); 2691 if (!type->isDependentType() && 2692 !type->isObjCObjectPointerType()) { 2693 const PointerType *pointerType = type->getAs<PointerType>(); 2694 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2695 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2696 << type << operand->getSourceRange(); 2697 } 2698 2699 // The operand to @synchronized is a full-expression. 2700 return MaybeCreateExprWithCleanups(operand); 2701} 2702 2703StmtResult 2704Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2705 Stmt *SyncBody) { 2706 // We can't jump into or indirect-jump out of a @synchronized block. 2707 getCurFunction()->setHasBranchProtectedScope(); 2708 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2709} 2710 2711/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2712/// and creates a proper catch handler from them. 2713StmtResult 2714Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2715 Stmt *HandlerBlock) { 2716 // There's nothing to test that ActOnExceptionDecl didn't already test. 2717 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2718 cast_or_null<VarDecl>(ExDecl), 2719 HandlerBlock)); 2720} 2721 2722StmtResult 2723Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2724 getCurFunction()->setHasBranchProtectedScope(); 2725 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2726} 2727 2728namespace { 2729 2730class TypeWithHandler { 2731 QualType t; 2732 CXXCatchStmt *stmt; 2733public: 2734 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2735 : t(type), stmt(statement) {} 2736 2737 // An arbitrary order is fine as long as it places identical 2738 // types next to each other. 2739 bool operator<(const TypeWithHandler &y) const { 2740 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2741 return true; 2742 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2743 return false; 2744 else 2745 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2746 } 2747 2748 bool operator==(const TypeWithHandler& other) const { 2749 return t == other.t; 2750 } 2751 2752 CXXCatchStmt *getCatchStmt() const { return stmt; } 2753 SourceLocation getTypeSpecStartLoc() const { 2754 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2755 } 2756}; 2757 2758} 2759 2760/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2761/// handlers and creates a try statement from them. 2762StmtResult 2763Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2764 MultiStmtArg RawHandlers) { 2765 // Don't report an error if 'try' is used in system headers. 2766 if (!getLangOpts().CXXExceptions && 2767 !getSourceManager().isInSystemHeader(TryLoc)) 2768 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2769 2770 unsigned NumHandlers = RawHandlers.size(); 2771 assert(NumHandlers > 0 && 2772 "The parser shouldn't call this if there are no handlers."); 2773 Stmt **Handlers = RawHandlers.get(); 2774 2775 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2776 2777 for (unsigned i = 0; i < NumHandlers; ++i) { 2778 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 2779 if (!Handler->getExceptionDecl()) { 2780 if (i < NumHandlers - 1) 2781 return StmtError(Diag(Handler->getLocStart(), 2782 diag::err_early_catch_all)); 2783 2784 continue; 2785 } 2786 2787 const QualType CaughtType = Handler->getCaughtType(); 2788 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2789 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2790 } 2791 2792 // Detect handlers for the same type as an earlier one. 2793 if (NumHandlers > 1) { 2794 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2795 2796 TypeWithHandler prev = TypesWithHandlers[0]; 2797 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2798 TypeWithHandler curr = TypesWithHandlers[i]; 2799 2800 if (curr == prev) { 2801 Diag(curr.getTypeSpecStartLoc(), 2802 diag::warn_exception_caught_by_earlier_handler) 2803 << curr.getCatchStmt()->getCaughtType().getAsString(); 2804 Diag(prev.getTypeSpecStartLoc(), 2805 diag::note_previous_exception_handler) 2806 << prev.getCatchStmt()->getCaughtType().getAsString(); 2807 } 2808 2809 prev = curr; 2810 } 2811 } 2812 2813 getCurFunction()->setHasBranchProtectedScope(); 2814 2815 // FIXME: We should detect handlers that cannot catch anything because an 2816 // earlier handler catches a superclass. Need to find a method that is not 2817 // quadratic for this. 2818 // Neither of these are explicitly forbidden, but every compiler detects them 2819 // and warns. 2820 2821 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2822 Handlers, NumHandlers)); 2823} 2824 2825StmtResult 2826Sema::ActOnSEHTryBlock(bool IsCXXTry, 2827 SourceLocation TryLoc, 2828 Stmt *TryBlock, 2829 Stmt *Handler) { 2830 assert(TryBlock && Handler); 2831 2832 getCurFunction()->setHasBranchProtectedScope(); 2833 2834 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2835} 2836 2837StmtResult 2838Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2839 Expr *FilterExpr, 2840 Stmt *Block) { 2841 assert(FilterExpr && Block); 2842 2843 if(!FilterExpr->getType()->isIntegerType()) { 2844 return StmtError(Diag(FilterExpr->getExprLoc(), 2845 diag::err_filter_expression_integral) 2846 << FilterExpr->getType()); 2847 } 2848 2849 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2850} 2851 2852StmtResult 2853Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2854 Stmt *Block) { 2855 assert(Block); 2856 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2857} 2858 2859StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, 2860 bool IsIfExists, 2861 NestedNameSpecifierLoc QualifierLoc, 2862 DeclarationNameInfo NameInfo, 2863 Stmt *Nested) 2864{ 2865 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, 2866 QualifierLoc, NameInfo, 2867 cast<CompoundStmt>(Nested)); 2868} 2869 2870 2871StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, 2872 bool IsIfExists, 2873 CXXScopeSpec &SS, 2874 UnqualifiedId &Name, 2875 Stmt *Nested) { 2876 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, 2877 SS.getWithLocInContext(Context), 2878 GetNameFromUnqualifiedId(Name), 2879 Nested); 2880} 2881