SemaStmt.cpp revision 243830
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/SmallString.h" 34#include "llvm/ADT/SmallVector.h" 35using namespace clang; 36using namespace sema; 37 38StmtResult Sema::ActOnExprStmt(FullExprArg expr) { 39 Expr *E = expr.get(); 40 if (!E) // FIXME: FullExprArg has no error state? 41 return StmtError(); 42 43 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 44 // void expression for its side effects. Conversion to void allows any 45 // operand, even incomplete types. 46 47 // Same thing in for stmt first clause (when expr) and third clause. 48 return Owned(static_cast<Stmt*>(E)); 49} 50 51 52StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, 53 bool HasLeadingEmptyMacro) { 54 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); 55} 56 57StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, 58 SourceLocation EndLoc) { 59 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 60 61 // If we have an invalid decl, just return an error. 62 if (DG.isNull()) return StmtError(); 63 64 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 65} 66 67void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { 68 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 69 70 // If we have an invalid decl, just return. 71 if (DG.isNull() || !DG.isSingleDecl()) return; 72 VarDecl *var = cast<VarDecl>(DG.getSingleDecl()); 73 74 // suppress any potential 'unused variable' warning. 75 var->setUsed(); 76 77 // foreach variables are never actually initialized in the way that 78 // the parser came up with. 79 var->setInit(0); 80 81 // In ARC, we don't need to retain the iteration variable of a fast 82 // enumeration loop. Rather than actually trying to catch that 83 // during declaration processing, we remove the consequences here. 84 if (getLangOpts().ObjCAutoRefCount) { 85 QualType type = var->getType(); 86 87 // Only do this if we inferred the lifetime. Inferred lifetime 88 // will show up as a local qualifier because explicit lifetime 89 // should have shown up as an AttributedType instead. 90 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { 91 // Add 'const' and mark the variable as pseudo-strong. 92 var->setType(type.withConst()); 93 var->setARCPseudoStrong(true); 94 } 95 } 96} 97 98/// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. 99/// 100/// Adding a cast to void (or other expression wrappers) will prevent the 101/// warning from firing. 102static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { 103 SourceLocation Loc; 104 bool IsNotEqual, CanAssign; 105 106 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { 107 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) 108 return false; 109 110 Loc = Op->getOperatorLoc(); 111 IsNotEqual = Op->getOpcode() == BO_NE; 112 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); 113 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { 114 if (Op->getOperator() != OO_EqualEqual && 115 Op->getOperator() != OO_ExclaimEqual) 116 return false; 117 118 Loc = Op->getOperatorLoc(); 119 IsNotEqual = Op->getOperator() == OO_ExclaimEqual; 120 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); 121 } else { 122 // Not a typo-prone comparison. 123 return false; 124 } 125 126 // Suppress warnings when the operator, suspicious as it may be, comes from 127 // a macro expansion. 128 if (Loc.isMacroID()) 129 return false; 130 131 S.Diag(Loc, diag::warn_unused_comparison) 132 << (unsigned)IsNotEqual << E->getSourceRange(); 133 134 // If the LHS is a plausible entity to assign to, provide a fixit hint to 135 // correct common typos. 136 if (CanAssign) { 137 if (IsNotEqual) 138 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) 139 << FixItHint::CreateReplacement(Loc, "|="); 140 else 141 S.Diag(Loc, diag::note_equality_comparison_to_assign) 142 << FixItHint::CreateReplacement(Loc, "="); 143 } 144 145 return true; 146} 147 148void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 149 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 150 return DiagnoseUnusedExprResult(Label->getSubStmt()); 151 152 const Expr *E = dyn_cast_or_null<Expr>(S); 153 if (!E) 154 return; 155 156 const Expr *WarnExpr; 157 SourceLocation Loc; 158 SourceRange R1, R2; 159 if (SourceMgr.isInSystemMacro(E->getExprLoc()) || 160 !E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context)) 161 return; 162 163 // If this is a GNU statement expression expanded from a macro, it is probably 164 // unused because it is a function-like macro that can be used as either an 165 // expression or statement. Don't warn, because it is almost certainly a 166 // false positive. 167 if (isa<StmtExpr>(E) && Loc.isMacroID()) 168 return; 169 170 // Okay, we have an unused result. Depending on what the base expression is, 171 // we might want to make a more specific diagnostic. Check for one of these 172 // cases now. 173 unsigned DiagID = diag::warn_unused_expr; 174 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 175 E = Temps->getSubExpr(); 176 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 177 E = TempExpr->getSubExpr(); 178 179 if (DiagnoseUnusedComparison(*this, E)) 180 return; 181 182 E = WarnExpr; 183 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 184 if (E->getType()->isVoidType()) 185 return; 186 187 // If the callee has attribute pure, const, or warn_unused_result, warn with 188 // a more specific message to make it clear what is happening. 189 if (const Decl *FD = CE->getCalleeDecl()) { 190 if (FD->getAttr<WarnUnusedResultAttr>()) { 191 Diag(Loc, diag::warn_unused_result) << R1 << R2; 192 return; 193 } 194 if (FD->getAttr<PureAttr>()) { 195 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 196 return; 197 } 198 if (FD->getAttr<ConstAttr>()) { 199 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 200 return; 201 } 202 } 203 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 204 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { 205 Diag(Loc, diag::err_arc_unused_init_message) << R1; 206 return; 207 } 208 const ObjCMethodDecl *MD = ME->getMethodDecl(); 209 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 210 Diag(Loc, diag::warn_unused_result) << R1 << R2; 211 return; 212 } 213 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 214 const Expr *Source = POE->getSyntacticForm(); 215 if (isa<ObjCSubscriptRefExpr>(Source)) 216 DiagID = diag::warn_unused_container_subscript_expr; 217 else 218 DiagID = diag::warn_unused_property_expr; 219 } else if (const CXXFunctionalCastExpr *FC 220 = dyn_cast<CXXFunctionalCastExpr>(E)) { 221 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 222 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 223 return; 224 } 225 // Diagnose "(void*) blah" as a typo for "(void) blah". 226 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 227 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 228 QualType T = TI->getType(); 229 230 // We really do want to use the non-canonical type here. 231 if (T == Context.VoidPtrTy) { 232 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 233 234 Diag(Loc, diag::warn_unused_voidptr) 235 << FixItHint::CreateRemoval(TL.getStarLoc()); 236 return; 237 } 238 } 239 240 if (E->isGLValue() && E->getType().isVolatileQualified()) { 241 Diag(Loc, diag::warn_unused_volatile) << R1 << R2; 242 return; 243 } 244 245 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 246} 247 248void Sema::ActOnStartOfCompoundStmt() { 249 PushCompoundScope(); 250} 251 252void Sema::ActOnFinishOfCompoundStmt() { 253 PopCompoundScope(); 254} 255 256sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { 257 return getCurFunction()->CompoundScopes.back(); 258} 259 260StmtResult 261Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 262 MultiStmtArg elts, bool isStmtExpr) { 263 unsigned NumElts = elts.size(); 264 Stmt **Elts = elts.data(); 265 // If we're in C89 mode, check that we don't have any decls after stmts. If 266 // so, emit an extension diagnostic. 267 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { 268 // Note that __extension__ can be around a decl. 269 unsigned i = 0; 270 // Skip over all declarations. 271 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 272 /*empty*/; 273 274 // We found the end of the list or a statement. Scan for another declstmt. 275 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 276 /*empty*/; 277 278 if (i != NumElts) { 279 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 280 Diag(D->getLocation(), diag::ext_mixed_decls_code); 281 } 282 } 283 // Warn about unused expressions in statements. 284 for (unsigned i = 0; i != NumElts; ++i) { 285 // Ignore statements that are last in a statement expression. 286 if (isStmtExpr && i == NumElts - 1) 287 continue; 288 289 DiagnoseUnusedExprResult(Elts[i]); 290 } 291 292 // Check for suspicious empty body (null statement) in `for' and `while' 293 // statements. Don't do anything for template instantiations, this just adds 294 // noise. 295 if (NumElts != 0 && !CurrentInstantiationScope && 296 getCurCompoundScope().HasEmptyLoopBodies) { 297 for (unsigned i = 0; i != NumElts - 1; ++i) 298 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); 299 } 300 301 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 302} 303 304StmtResult 305Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 306 SourceLocation DotDotDotLoc, Expr *RHSVal, 307 SourceLocation ColonLoc) { 308 assert((LHSVal != 0) && "missing expression in case statement"); 309 310 if (getCurFunction()->SwitchStack.empty()) { 311 Diag(CaseLoc, diag::err_case_not_in_switch); 312 return StmtError(); 313 } 314 315 if (!getLangOpts().CPlusPlus0x) { 316 // C99 6.8.4.2p3: The expression shall be an integer constant. 317 // However, GCC allows any evaluatable integer expression. 318 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { 319 LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); 320 if (!LHSVal) 321 return StmtError(); 322 } 323 324 // GCC extension: The expression shall be an integer constant. 325 326 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { 327 RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); 328 // Recover from an error by just forgetting about it. 329 } 330 } 331 332 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 333 ColonLoc); 334 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 335 return Owned(CS); 336} 337 338/// ActOnCaseStmtBody - This installs a statement as the body of a case. 339void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 340 DiagnoseUnusedExprResult(SubStmt); 341 342 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 343 CS->setSubStmt(SubStmt); 344} 345 346StmtResult 347Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 348 Stmt *SubStmt, Scope *CurScope) { 349 DiagnoseUnusedExprResult(SubStmt); 350 351 if (getCurFunction()->SwitchStack.empty()) { 352 Diag(DefaultLoc, diag::err_default_not_in_switch); 353 return Owned(SubStmt); 354 } 355 356 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 357 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 358 return Owned(DS); 359} 360 361StmtResult 362Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 363 SourceLocation ColonLoc, Stmt *SubStmt) { 364 // If the label was multiply defined, reject it now. 365 if (TheDecl->getStmt()) { 366 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 367 Diag(TheDecl->getLocation(), diag::note_previous_definition); 368 return Owned(SubStmt); 369 } 370 371 // Otherwise, things are good. Fill in the declaration and return it. 372 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 373 TheDecl->setStmt(LS); 374 if (!TheDecl->isGnuLocal()) { 375 TheDecl->setLocStart(IdentLoc); 376 TheDecl->setLocation(IdentLoc); 377 } 378 return Owned(LS); 379} 380 381StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, 382 ArrayRef<const Attr*> Attrs, 383 Stmt *SubStmt) { 384 // Fill in the declaration and return it. 385 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt); 386 return Owned(LS); 387} 388 389StmtResult 390Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 391 Stmt *thenStmt, SourceLocation ElseLoc, 392 Stmt *elseStmt) { 393 ExprResult CondResult(CondVal.release()); 394 395 VarDecl *ConditionVar = 0; 396 if (CondVar) { 397 ConditionVar = cast<VarDecl>(CondVar); 398 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 399 if (CondResult.isInvalid()) 400 return StmtError(); 401 } 402 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 403 if (!ConditionExpr) 404 return StmtError(); 405 406 DiagnoseUnusedExprResult(thenStmt); 407 408 if (!elseStmt) { 409 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, 410 diag::warn_empty_if_body); 411 } 412 413 DiagnoseUnusedExprResult(elseStmt); 414 415 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 416 thenStmt, ElseLoc, elseStmt)); 417} 418 419/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 420/// the specified width and sign. If an overflow occurs, detect it and emit 421/// the specified diagnostic. 422void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 423 unsigned NewWidth, bool NewSign, 424 SourceLocation Loc, 425 unsigned DiagID) { 426 // Perform a conversion to the promoted condition type if needed. 427 if (NewWidth > Val.getBitWidth()) { 428 // If this is an extension, just do it. 429 Val = Val.extend(NewWidth); 430 Val.setIsSigned(NewSign); 431 432 // If the input was signed and negative and the output is 433 // unsigned, don't bother to warn: this is implementation-defined 434 // behavior. 435 // FIXME: Introduce a second, default-ignored warning for this case? 436 } else if (NewWidth < Val.getBitWidth()) { 437 // If this is a truncation, check for overflow. 438 llvm::APSInt ConvVal(Val); 439 ConvVal = ConvVal.trunc(NewWidth); 440 ConvVal.setIsSigned(NewSign); 441 ConvVal = ConvVal.extend(Val.getBitWidth()); 442 ConvVal.setIsSigned(Val.isSigned()); 443 if (ConvVal != Val) 444 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 445 446 // Regardless of whether a diagnostic was emitted, really do the 447 // truncation. 448 Val = Val.trunc(NewWidth); 449 Val.setIsSigned(NewSign); 450 } else if (NewSign != Val.isSigned()) { 451 // Convert the sign to match the sign of the condition. This can cause 452 // overflow as well: unsigned(INTMIN) 453 // We don't diagnose this overflow, because it is implementation-defined 454 // behavior. 455 // FIXME: Introduce a second, default-ignored warning for this case? 456 llvm::APSInt OldVal(Val); 457 Val.setIsSigned(NewSign); 458 } 459} 460 461namespace { 462 struct CaseCompareFunctor { 463 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 464 const llvm::APSInt &RHS) { 465 return LHS.first < RHS; 466 } 467 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 468 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 469 return LHS.first < RHS.first; 470 } 471 bool operator()(const llvm::APSInt &LHS, 472 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 473 return LHS < RHS.first; 474 } 475 }; 476} 477 478/// CmpCaseVals - Comparison predicate for sorting case values. 479/// 480static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 481 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 482 if (lhs.first < rhs.first) 483 return true; 484 485 if (lhs.first == rhs.first && 486 lhs.second->getCaseLoc().getRawEncoding() 487 < rhs.second->getCaseLoc().getRawEncoding()) 488 return true; 489 return false; 490} 491 492/// CmpEnumVals - Comparison predicate for sorting enumeration values. 493/// 494static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 495 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 496{ 497 return lhs.first < rhs.first; 498} 499 500/// EqEnumVals - Comparison preficate for uniqing enumeration values. 501/// 502static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 503 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 504{ 505 return lhs.first == rhs.first; 506} 507 508/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 509/// potentially integral-promoted expression @p expr. 510static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 511 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 512 expr = cleanups->getSubExpr(); 513 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 514 if (impcast->getCastKind() != CK_IntegralCast) break; 515 expr = impcast->getSubExpr(); 516 } 517 return expr->getType(); 518} 519 520StmtResult 521Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 522 Decl *CondVar) { 523 ExprResult CondResult; 524 525 VarDecl *ConditionVar = 0; 526 if (CondVar) { 527 ConditionVar = cast<VarDecl>(CondVar); 528 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 529 if (CondResult.isInvalid()) 530 return StmtError(); 531 532 Cond = CondResult.release(); 533 } 534 535 if (!Cond) 536 return StmtError(); 537 538 class SwitchConvertDiagnoser : public ICEConvertDiagnoser { 539 Expr *Cond; 540 541 public: 542 SwitchConvertDiagnoser(Expr *Cond) 543 : ICEConvertDiagnoser(false, true), Cond(Cond) { } 544 545 virtual DiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 546 QualType T) { 547 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T; 548 } 549 550 virtual DiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 551 QualType T) { 552 return S.Diag(Loc, diag::err_switch_incomplete_class_type) 553 << T << Cond->getSourceRange(); 554 } 555 556 virtual DiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 557 QualType T, 558 QualType ConvTy) { 559 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy; 560 } 561 562 virtual DiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 563 QualType ConvTy) { 564 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 565 << ConvTy->isEnumeralType() << ConvTy; 566 } 567 568 virtual DiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 569 QualType T) { 570 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T; 571 } 572 573 virtual DiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 574 QualType ConvTy) { 575 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 576 << ConvTy->isEnumeralType() << ConvTy; 577 } 578 579 virtual DiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 580 QualType T, 581 QualType ConvTy) { 582 return DiagnosticBuilder::getEmpty(); 583 } 584 } SwitchDiagnoser(Cond); 585 586 CondResult 587 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, SwitchDiagnoser, 588 /*AllowScopedEnumerations*/ true); 589 if (CondResult.isInvalid()) return StmtError(); 590 Cond = CondResult.take(); 591 592 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 593 CondResult = UsualUnaryConversions(Cond); 594 if (CondResult.isInvalid()) return StmtError(); 595 Cond = CondResult.take(); 596 597 if (!CondVar) { 598 CheckImplicitConversions(Cond, SwitchLoc); 599 CondResult = MaybeCreateExprWithCleanups(Cond); 600 if (CondResult.isInvalid()) 601 return StmtError(); 602 Cond = CondResult.take(); 603 } 604 605 getCurFunction()->setHasBranchIntoScope(); 606 607 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 608 getCurFunction()->SwitchStack.push_back(SS); 609 return Owned(SS); 610} 611 612static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 613 if (Val.getBitWidth() < BitWidth) 614 Val = Val.extend(BitWidth); 615 else if (Val.getBitWidth() > BitWidth) 616 Val = Val.trunc(BitWidth); 617 Val.setIsSigned(IsSigned); 618} 619 620StmtResult 621Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 622 Stmt *BodyStmt) { 623 SwitchStmt *SS = cast<SwitchStmt>(Switch); 624 assert(SS == getCurFunction()->SwitchStack.back() && 625 "switch stack missing push/pop!"); 626 627 SS->setBody(BodyStmt, SwitchLoc); 628 getCurFunction()->SwitchStack.pop_back(); 629 630 Expr *CondExpr = SS->getCond(); 631 if (!CondExpr) return StmtError(); 632 633 QualType CondType = CondExpr->getType(); 634 635 Expr *CondExprBeforePromotion = CondExpr; 636 QualType CondTypeBeforePromotion = 637 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 638 639 // C++ 6.4.2.p2: 640 // Integral promotions are performed (on the switch condition). 641 // 642 // A case value unrepresentable by the original switch condition 643 // type (before the promotion) doesn't make sense, even when it can 644 // be represented by the promoted type. Therefore we need to find 645 // the pre-promotion type of the switch condition. 646 if (!CondExpr->isTypeDependent()) { 647 // We have already converted the expression to an integral or enumeration 648 // type, when we started the switch statement. If we don't have an 649 // appropriate type now, just return an error. 650 if (!CondType->isIntegralOrEnumerationType()) 651 return StmtError(); 652 653 if (CondExpr->isKnownToHaveBooleanValue()) { 654 // switch(bool_expr) {...} is often a programmer error, e.g. 655 // switch(n && mask) { ... } // Doh - should be "n & mask". 656 // One can always use an if statement instead of switch(bool_expr). 657 Diag(SwitchLoc, diag::warn_bool_switch_condition) 658 << CondExpr->getSourceRange(); 659 } 660 } 661 662 // Get the bitwidth of the switched-on value before promotions. We must 663 // convert the integer case values to this width before comparison. 664 bool HasDependentValue 665 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 666 unsigned CondWidth 667 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 668 bool CondIsSigned 669 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 670 671 // Accumulate all of the case values in a vector so that we can sort them 672 // and detect duplicates. This vector contains the APInt for the case after 673 // it has been converted to the condition type. 674 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 675 CaseValsTy CaseVals; 676 677 // Keep track of any GNU case ranges we see. The APSInt is the low value. 678 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 679 CaseRangesTy CaseRanges; 680 681 DefaultStmt *TheDefaultStmt = 0; 682 683 bool CaseListIsErroneous = false; 684 685 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 686 SC = SC->getNextSwitchCase()) { 687 688 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 689 if (TheDefaultStmt) { 690 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 691 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 692 693 // FIXME: Remove the default statement from the switch block so that 694 // we'll return a valid AST. This requires recursing down the AST and 695 // finding it, not something we are set up to do right now. For now, 696 // just lop the entire switch stmt out of the AST. 697 CaseListIsErroneous = true; 698 } 699 TheDefaultStmt = DS; 700 701 } else { 702 CaseStmt *CS = cast<CaseStmt>(SC); 703 704 Expr *Lo = CS->getLHS(); 705 706 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 707 HasDependentValue = true; 708 break; 709 } 710 711 llvm::APSInt LoVal; 712 713 if (getLangOpts().CPlusPlus0x) { 714 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 715 // constant expression of the promoted type of the switch condition. 716 ExprResult ConvLo = 717 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); 718 if (ConvLo.isInvalid()) { 719 CaseListIsErroneous = true; 720 continue; 721 } 722 Lo = ConvLo.take(); 723 } else { 724 // We already verified that the expression has a i-c-e value (C99 725 // 6.8.4.2p3) - get that value now. 726 LoVal = Lo->EvaluateKnownConstInt(Context); 727 728 // If the LHS is not the same type as the condition, insert an implicit 729 // cast. 730 Lo = DefaultLvalueConversion(Lo).take(); 731 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 732 } 733 734 // Convert the value to the same width/sign as the condition had prior to 735 // integral promotions. 736 // 737 // FIXME: This causes us to reject valid code: 738 // switch ((char)c) { case 256: case 0: return 0; } 739 // Here we claim there is a duplicated condition value, but there is not. 740 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 741 Lo->getLocStart(), 742 diag::warn_case_value_overflow); 743 744 CS->setLHS(Lo); 745 746 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 747 if (CS->getRHS()) { 748 if (CS->getRHS()->isTypeDependent() || 749 CS->getRHS()->isValueDependent()) { 750 HasDependentValue = true; 751 break; 752 } 753 CaseRanges.push_back(std::make_pair(LoVal, CS)); 754 } else 755 CaseVals.push_back(std::make_pair(LoVal, CS)); 756 } 757 } 758 759 if (!HasDependentValue) { 760 // If we don't have a default statement, check whether the 761 // condition is constant. 762 llvm::APSInt ConstantCondValue; 763 bool HasConstantCond = false; 764 if (!HasDependentValue && !TheDefaultStmt) { 765 HasConstantCond 766 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, 767 Expr::SE_AllowSideEffects); 768 assert(!HasConstantCond || 769 (ConstantCondValue.getBitWidth() == CondWidth && 770 ConstantCondValue.isSigned() == CondIsSigned)); 771 } 772 bool ShouldCheckConstantCond = HasConstantCond; 773 774 // Sort all the scalar case values so we can easily detect duplicates. 775 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 776 777 if (!CaseVals.empty()) { 778 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 779 if (ShouldCheckConstantCond && 780 CaseVals[i].first == ConstantCondValue) 781 ShouldCheckConstantCond = false; 782 783 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 784 // If we have a duplicate, report it. 785 // First, determine if either case value has a name 786 StringRef PrevString, CurrString; 787 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts(); 788 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts(); 789 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) { 790 PrevString = DeclRef->getDecl()->getName(); 791 } 792 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) { 793 CurrString = DeclRef->getDecl()->getName(); 794 } 795 llvm::SmallString<16> CaseValStr; 796 CaseVals[i-1].first.toString(CaseValStr); 797 798 if (PrevString == CurrString) 799 Diag(CaseVals[i].second->getLHS()->getLocStart(), 800 diag::err_duplicate_case) << 801 (PrevString.empty() ? CaseValStr.str() : PrevString); 802 else 803 Diag(CaseVals[i].second->getLHS()->getLocStart(), 804 diag::err_duplicate_case_differing_expr) << 805 (PrevString.empty() ? CaseValStr.str() : PrevString) << 806 (CurrString.empty() ? CaseValStr.str() : CurrString) << 807 CaseValStr; 808 809 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 810 diag::note_duplicate_case_prev); 811 // FIXME: We really want to remove the bogus case stmt from the 812 // substmt, but we have no way to do this right now. 813 CaseListIsErroneous = true; 814 } 815 } 816 } 817 818 // Detect duplicate case ranges, which usually don't exist at all in 819 // the first place. 820 if (!CaseRanges.empty()) { 821 // Sort all the case ranges by their low value so we can easily detect 822 // overlaps between ranges. 823 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 824 825 // Scan the ranges, computing the high values and removing empty ranges. 826 std::vector<llvm::APSInt> HiVals; 827 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 828 llvm::APSInt &LoVal = CaseRanges[i].first; 829 CaseStmt *CR = CaseRanges[i].second; 830 Expr *Hi = CR->getRHS(); 831 llvm::APSInt HiVal; 832 833 if (getLangOpts().CPlusPlus0x) { 834 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 835 // constant expression of the promoted type of the switch condition. 836 ExprResult ConvHi = 837 CheckConvertedConstantExpression(Hi, CondType, HiVal, 838 CCEK_CaseValue); 839 if (ConvHi.isInvalid()) { 840 CaseListIsErroneous = true; 841 continue; 842 } 843 Hi = ConvHi.take(); 844 } else { 845 HiVal = Hi->EvaluateKnownConstInt(Context); 846 847 // If the RHS is not the same type as the condition, insert an 848 // implicit cast. 849 Hi = DefaultLvalueConversion(Hi).take(); 850 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 851 } 852 853 // Convert the value to the same width/sign as the condition. 854 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 855 Hi->getLocStart(), 856 diag::warn_case_value_overflow); 857 858 CR->setRHS(Hi); 859 860 // If the low value is bigger than the high value, the case is empty. 861 if (LoVal > HiVal) { 862 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 863 << SourceRange(CR->getLHS()->getLocStart(), 864 Hi->getLocEnd()); 865 CaseRanges.erase(CaseRanges.begin()+i); 866 --i, --e; 867 continue; 868 } 869 870 if (ShouldCheckConstantCond && 871 LoVal <= ConstantCondValue && 872 ConstantCondValue <= HiVal) 873 ShouldCheckConstantCond = false; 874 875 HiVals.push_back(HiVal); 876 } 877 878 // Rescan the ranges, looking for overlap with singleton values and other 879 // ranges. Since the range list is sorted, we only need to compare case 880 // ranges with their neighbors. 881 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 882 llvm::APSInt &CRLo = CaseRanges[i].first; 883 llvm::APSInt &CRHi = HiVals[i]; 884 CaseStmt *CR = CaseRanges[i].second; 885 886 // Check to see whether the case range overlaps with any 887 // singleton cases. 888 CaseStmt *OverlapStmt = 0; 889 llvm::APSInt OverlapVal(32); 890 891 // Find the smallest value >= the lower bound. If I is in the 892 // case range, then we have overlap. 893 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 894 CaseVals.end(), CRLo, 895 CaseCompareFunctor()); 896 if (I != CaseVals.end() && I->first < CRHi) { 897 OverlapVal = I->first; // Found overlap with scalar. 898 OverlapStmt = I->second; 899 } 900 901 // Find the smallest value bigger than the upper bound. 902 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 903 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 904 OverlapVal = (I-1)->first; // Found overlap with scalar. 905 OverlapStmt = (I-1)->second; 906 } 907 908 // Check to see if this case stmt overlaps with the subsequent 909 // case range. 910 if (i && CRLo <= HiVals[i-1]) { 911 OverlapVal = HiVals[i-1]; // Found overlap with range. 912 OverlapStmt = CaseRanges[i-1].second; 913 } 914 915 if (OverlapStmt) { 916 // If we have a duplicate, report it. 917 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 918 << OverlapVal.toString(10); 919 Diag(OverlapStmt->getLHS()->getLocStart(), 920 diag::note_duplicate_case_prev); 921 // FIXME: We really want to remove the bogus case stmt from the 922 // substmt, but we have no way to do this right now. 923 CaseListIsErroneous = true; 924 } 925 } 926 } 927 928 // Complain if we have a constant condition and we didn't find a match. 929 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 930 // TODO: it would be nice if we printed enums as enums, chars as 931 // chars, etc. 932 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 933 << ConstantCondValue.toString(10) 934 << CondExpr->getSourceRange(); 935 } 936 937 // Check to see if switch is over an Enum and handles all of its 938 // values. We only issue a warning if there is not 'default:', but 939 // we still do the analysis to preserve this information in the AST 940 // (which can be used by flow-based analyes). 941 // 942 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 943 944 // If switch has default case, then ignore it. 945 if (!CaseListIsErroneous && !HasConstantCond && ET) { 946 const EnumDecl *ED = ET->getDecl(); 947 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 948 EnumValsTy; 949 EnumValsTy EnumVals; 950 951 // Gather all enum values, set their type and sort them, 952 // allowing easier comparison with CaseVals. 953 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 954 EDI != ED->enumerator_end(); ++EDI) { 955 llvm::APSInt Val = EDI->getInitVal(); 956 AdjustAPSInt(Val, CondWidth, CondIsSigned); 957 EnumVals.push_back(std::make_pair(Val, *EDI)); 958 } 959 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 960 EnumValsTy::iterator EIend = 961 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 962 963 // See which case values aren't in enum. 964 EnumValsTy::const_iterator EI = EnumVals.begin(); 965 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 966 CI != CaseVals.end(); CI++) { 967 while (EI != EIend && EI->first < CI->first) 968 EI++; 969 if (EI == EIend || EI->first > CI->first) 970 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 971 << CondTypeBeforePromotion; 972 } 973 // See which of case ranges aren't in enum 974 EI = EnumVals.begin(); 975 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 976 RI != CaseRanges.end() && EI != EIend; RI++) { 977 while (EI != EIend && EI->first < RI->first) 978 EI++; 979 980 if (EI == EIend || EI->first != RI->first) { 981 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 982 << CondTypeBeforePromotion; 983 } 984 985 llvm::APSInt Hi = 986 RI->second->getRHS()->EvaluateKnownConstInt(Context); 987 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 988 while (EI != EIend && EI->first < Hi) 989 EI++; 990 if (EI == EIend || EI->first != Hi) 991 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 992 << CondTypeBeforePromotion; 993 } 994 995 // Check which enum vals aren't in switch 996 CaseValsTy::const_iterator CI = CaseVals.begin(); 997 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 998 bool hasCasesNotInSwitch = false; 999 1000 SmallVector<DeclarationName,8> UnhandledNames; 1001 1002 for (EI = EnumVals.begin(); EI != EIend; EI++){ 1003 // Drop unneeded case values 1004 llvm::APSInt CIVal; 1005 while (CI != CaseVals.end() && CI->first < EI->first) 1006 CI++; 1007 1008 if (CI != CaseVals.end() && CI->first == EI->first) 1009 continue; 1010 1011 // Drop unneeded case ranges 1012 for (; RI != CaseRanges.end(); RI++) { 1013 llvm::APSInt Hi = 1014 RI->second->getRHS()->EvaluateKnownConstInt(Context); 1015 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 1016 if (EI->first <= Hi) 1017 break; 1018 } 1019 1020 if (RI == CaseRanges.end() || EI->first < RI->first) { 1021 hasCasesNotInSwitch = true; 1022 UnhandledNames.push_back(EI->second->getDeclName()); 1023 } 1024 } 1025 1026 if (TheDefaultStmt && UnhandledNames.empty()) 1027 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); 1028 1029 // Produce a nice diagnostic if multiple values aren't handled. 1030 switch (UnhandledNames.size()) { 1031 case 0: break; 1032 case 1: 1033 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1034 ? diag::warn_def_missing_case1 : diag::warn_missing_case1) 1035 << UnhandledNames[0]; 1036 break; 1037 case 2: 1038 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1039 ? diag::warn_def_missing_case2 : diag::warn_missing_case2) 1040 << UnhandledNames[0] << UnhandledNames[1]; 1041 break; 1042 case 3: 1043 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1044 ? diag::warn_def_missing_case3 : diag::warn_missing_case3) 1045 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1046 break; 1047 default: 1048 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1049 ? diag::warn_def_missing_cases : diag::warn_missing_cases) 1050 << (unsigned)UnhandledNames.size() 1051 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1052 break; 1053 } 1054 1055 if (!hasCasesNotInSwitch) 1056 SS->setAllEnumCasesCovered(); 1057 } 1058 } 1059 1060 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, 1061 diag::warn_empty_switch_body); 1062 1063 // FIXME: If the case list was broken is some way, we don't have a good system 1064 // to patch it up. Instead, just return the whole substmt as broken. 1065 if (CaseListIsErroneous) 1066 return StmtError(); 1067 1068 return Owned(SS); 1069} 1070 1071void 1072Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, 1073 Expr *SrcExpr) { 1074 unsigned DIAG = diag::warn_not_in_enum_assignement; 1075 if (Diags.getDiagnosticLevel(DIAG, SrcExpr->getExprLoc()) 1076 == DiagnosticsEngine::Ignored) 1077 return; 1078 1079 if (const EnumType *ET = DstType->getAs<EnumType>()) 1080 if (!Context.hasSameType(SrcType, DstType) && 1081 SrcType->isIntegerType()) { 1082 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() && 1083 SrcExpr->isIntegerConstantExpr(Context)) { 1084 // Get the bitwidth of the enum value before promotions. 1085 unsigned DstWith = Context.getIntWidth(DstType); 1086 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType(); 1087 1088 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context); 1089 const EnumDecl *ED = ET->getDecl(); 1090 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 1091 EnumValsTy; 1092 EnumValsTy EnumVals; 1093 1094 // Gather all enum values, set their type and sort them, 1095 // allowing easier comparison with rhs constant. 1096 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 1097 EDI != ED->enumerator_end(); ++EDI) { 1098 llvm::APSInt Val = EDI->getInitVal(); 1099 AdjustAPSInt(Val, DstWith, DstIsSigned); 1100 EnumVals.push_back(std::make_pair(Val, *EDI)); 1101 } 1102 if (EnumVals.empty()) 1103 return; 1104 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 1105 EnumValsTy::iterator EIend = 1106 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 1107 1108 // See which case values aren't in enum. 1109 EnumValsTy::const_iterator EI = EnumVals.begin(); 1110 while (EI != EIend && EI->first < RhsVal) 1111 EI++; 1112 if (EI == EIend || EI->first != RhsVal) { 1113 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignement) 1114 << DstType; 1115 } 1116 } 1117 } 1118} 1119 1120StmtResult 1121Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 1122 Decl *CondVar, Stmt *Body) { 1123 ExprResult CondResult(Cond.release()); 1124 1125 VarDecl *ConditionVar = 0; 1126 if (CondVar) { 1127 ConditionVar = cast<VarDecl>(CondVar); 1128 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 1129 if (CondResult.isInvalid()) 1130 return StmtError(); 1131 } 1132 Expr *ConditionExpr = CondResult.take(); 1133 if (!ConditionExpr) 1134 return StmtError(); 1135 1136 DiagnoseUnusedExprResult(Body); 1137 1138 if (isa<NullStmt>(Body)) 1139 getCurCompoundScope().setHasEmptyLoopBodies(); 1140 1141 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 1142 Body, WhileLoc)); 1143} 1144 1145StmtResult 1146Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 1147 SourceLocation WhileLoc, SourceLocation CondLParen, 1148 Expr *Cond, SourceLocation CondRParen) { 1149 assert(Cond && "ActOnDoStmt(): missing expression"); 1150 1151 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 1152 if (CondResult.isInvalid() || CondResult.isInvalid()) 1153 return StmtError(); 1154 Cond = CondResult.take(); 1155 1156 CheckImplicitConversions(Cond, DoLoc); 1157 CondResult = MaybeCreateExprWithCleanups(Cond); 1158 if (CondResult.isInvalid()) 1159 return StmtError(); 1160 Cond = CondResult.take(); 1161 1162 DiagnoseUnusedExprResult(Body); 1163 1164 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 1165} 1166 1167namespace { 1168 // This visitor will traverse a conditional statement and store all 1169 // the evaluated decls into a vector. Simple is set to true if none 1170 // of the excluded constructs are used. 1171 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { 1172 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1173 llvm::SmallVector<SourceRange, 10> &Ranges; 1174 bool Simple; 1175public: 1176 typedef EvaluatedExprVisitor<DeclExtractor> Inherited; 1177 1178 DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, 1179 llvm::SmallVector<SourceRange, 10> &Ranges) : 1180 Inherited(S.Context), 1181 Decls(Decls), 1182 Ranges(Ranges), 1183 Simple(true) {} 1184 1185 bool isSimple() { return Simple; } 1186 1187 // Replaces the method in EvaluatedExprVisitor. 1188 void VisitMemberExpr(MemberExpr* E) { 1189 Simple = false; 1190 } 1191 1192 // Any Stmt not whitelisted will cause the condition to be marked complex. 1193 void VisitStmt(Stmt *S) { 1194 Simple = false; 1195 } 1196 1197 void VisitBinaryOperator(BinaryOperator *E) { 1198 Visit(E->getLHS()); 1199 Visit(E->getRHS()); 1200 } 1201 1202 void VisitCastExpr(CastExpr *E) { 1203 Visit(E->getSubExpr()); 1204 } 1205 1206 void VisitUnaryOperator(UnaryOperator *E) { 1207 // Skip checking conditionals with derefernces. 1208 if (E->getOpcode() == UO_Deref) 1209 Simple = false; 1210 else 1211 Visit(E->getSubExpr()); 1212 } 1213 1214 void VisitConditionalOperator(ConditionalOperator *E) { 1215 Visit(E->getCond()); 1216 Visit(E->getTrueExpr()); 1217 Visit(E->getFalseExpr()); 1218 } 1219 1220 void VisitParenExpr(ParenExpr *E) { 1221 Visit(E->getSubExpr()); 1222 } 1223 1224 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { 1225 Visit(E->getOpaqueValue()->getSourceExpr()); 1226 Visit(E->getFalseExpr()); 1227 } 1228 1229 void VisitIntegerLiteral(IntegerLiteral *E) { } 1230 void VisitFloatingLiteral(FloatingLiteral *E) { } 1231 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } 1232 void VisitCharacterLiteral(CharacterLiteral *E) { } 1233 void VisitGNUNullExpr(GNUNullExpr *E) { } 1234 void VisitImaginaryLiteral(ImaginaryLiteral *E) { } 1235 1236 void VisitDeclRefExpr(DeclRefExpr *E) { 1237 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); 1238 if (!VD) return; 1239 1240 Ranges.push_back(E->getSourceRange()); 1241 1242 Decls.insert(VD); 1243 } 1244 1245 }; // end class DeclExtractor 1246 1247 // DeclMatcher checks to see if the decls are used in a non-evauluated 1248 // context. 1249 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { 1250 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1251 bool FoundDecl; 1252 1253public: 1254 typedef EvaluatedExprVisitor<DeclMatcher> Inherited; 1255 1256 DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, Stmt *Statement) : 1257 Inherited(S.Context), Decls(Decls), FoundDecl(false) { 1258 if (!Statement) return; 1259 1260 Visit(Statement); 1261 } 1262 1263 void VisitReturnStmt(ReturnStmt *S) { 1264 FoundDecl = true; 1265 } 1266 1267 void VisitBreakStmt(BreakStmt *S) { 1268 FoundDecl = true; 1269 } 1270 1271 void VisitGotoStmt(GotoStmt *S) { 1272 FoundDecl = true; 1273 } 1274 1275 void VisitCastExpr(CastExpr *E) { 1276 if (E->getCastKind() == CK_LValueToRValue) 1277 CheckLValueToRValueCast(E->getSubExpr()); 1278 else 1279 Visit(E->getSubExpr()); 1280 } 1281 1282 void CheckLValueToRValueCast(Expr *E) { 1283 E = E->IgnoreParenImpCasts(); 1284 1285 if (isa<DeclRefExpr>(E)) { 1286 return; 1287 } 1288 1289 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1290 Visit(CO->getCond()); 1291 CheckLValueToRValueCast(CO->getTrueExpr()); 1292 CheckLValueToRValueCast(CO->getFalseExpr()); 1293 return; 1294 } 1295 1296 if (BinaryConditionalOperator *BCO = 1297 dyn_cast<BinaryConditionalOperator>(E)) { 1298 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); 1299 CheckLValueToRValueCast(BCO->getFalseExpr()); 1300 return; 1301 } 1302 1303 Visit(E); 1304 } 1305 1306 void VisitDeclRefExpr(DeclRefExpr *E) { 1307 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) 1308 if (Decls.count(VD)) 1309 FoundDecl = true; 1310 } 1311 1312 bool FoundDeclInUse() { return FoundDecl; } 1313 1314 }; // end class DeclMatcher 1315 1316 void CheckForLoopConditionalStatement(Sema &S, Expr *Second, 1317 Expr *Third, Stmt *Body) { 1318 // Condition is empty 1319 if (!Second) return; 1320 1321 if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body, 1322 Second->getLocStart()) 1323 == DiagnosticsEngine::Ignored) 1324 return; 1325 1326 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); 1327 llvm::SmallPtrSet<VarDecl*, 8> Decls; 1328 llvm::SmallVector<SourceRange, 10> Ranges; 1329 DeclExtractor DE(S, Decls, Ranges); 1330 DE.Visit(Second); 1331 1332 // Don't analyze complex conditionals. 1333 if (!DE.isSimple()) return; 1334 1335 // No decls found. 1336 if (Decls.size() == 0) return; 1337 1338 // Don't warn on volatile, static, or global variables. 1339 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1340 E = Decls.end(); 1341 I != E; ++I) 1342 if ((*I)->getType().isVolatileQualified() || 1343 (*I)->hasGlobalStorage()) return; 1344 1345 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || 1346 DeclMatcher(S, Decls, Third).FoundDeclInUse() || 1347 DeclMatcher(S, Decls, Body).FoundDeclInUse()) 1348 return; 1349 1350 // Load decl names into diagnostic. 1351 if (Decls.size() > 4) 1352 PDiag << 0; 1353 else { 1354 PDiag << Decls.size(); 1355 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1356 E = Decls.end(); 1357 I != E; ++I) 1358 PDiag << (*I)->getDeclName(); 1359 } 1360 1361 // Load SourceRanges into diagnostic if there is room. 1362 // Otherwise, load the SourceRange of the conditional expression. 1363 if (Ranges.size() <= PartialDiagnostic::MaxArguments) 1364 for (llvm::SmallVector<SourceRange, 10>::iterator I = Ranges.begin(), 1365 E = Ranges.end(); 1366 I != E; ++I) 1367 PDiag << *I; 1368 else 1369 PDiag << Second->getSourceRange(); 1370 1371 S.Diag(Ranges.begin()->getBegin(), PDiag); 1372 } 1373 1374} // end namespace 1375 1376StmtResult 1377Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1378 Stmt *First, FullExprArg second, Decl *secondVar, 1379 FullExprArg third, 1380 SourceLocation RParenLoc, Stmt *Body) { 1381 if (!getLangOpts().CPlusPlus) { 1382 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 1383 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1384 // declare identifiers for objects having storage class 'auto' or 1385 // 'register'. 1386 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 1387 DI!=DE; ++DI) { 1388 VarDecl *VD = dyn_cast<VarDecl>(*DI); 1389 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 1390 VD = 0; 1391 if (VD == 0) 1392 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 1393 // FIXME: mark decl erroneous! 1394 } 1395 } 1396 } 1397 1398 CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body); 1399 1400 ExprResult SecondResult(second.release()); 1401 VarDecl *ConditionVar = 0; 1402 if (secondVar) { 1403 ConditionVar = cast<VarDecl>(secondVar); 1404 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 1405 if (SecondResult.isInvalid()) 1406 return StmtError(); 1407 } 1408 1409 Expr *Third = third.release().takeAs<Expr>(); 1410 1411 DiagnoseUnusedExprResult(First); 1412 DiagnoseUnusedExprResult(Third); 1413 DiagnoseUnusedExprResult(Body); 1414 1415 if (isa<NullStmt>(Body)) 1416 getCurCompoundScope().setHasEmptyLoopBodies(); 1417 1418 return Owned(new (Context) ForStmt(Context, First, 1419 SecondResult.take(), ConditionVar, 1420 Third, Body, ForLoc, LParenLoc, 1421 RParenLoc)); 1422} 1423 1424/// In an Objective C collection iteration statement: 1425/// for (x in y) 1426/// x can be an arbitrary l-value expression. Bind it up as a 1427/// full-expression. 1428StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1429 // Reduce placeholder expressions here. Note that this rejects the 1430 // use of pseudo-object l-values in this position. 1431 ExprResult result = CheckPlaceholderExpr(E); 1432 if (result.isInvalid()) return StmtError(); 1433 E = result.take(); 1434 1435 CheckImplicitConversions(E); 1436 1437 result = MaybeCreateExprWithCleanups(E); 1438 if (result.isInvalid()) return StmtError(); 1439 1440 return Owned(static_cast<Stmt*>(result.take())); 1441} 1442 1443ExprResult 1444Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1445 if (!collection) 1446 return ExprError(); 1447 1448 // Bail out early if we've got a type-dependent expression. 1449 if (collection->isTypeDependent()) return Owned(collection); 1450 1451 // Perform normal l-value conversion. 1452 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1453 if (result.isInvalid()) 1454 return ExprError(); 1455 collection = result.take(); 1456 1457 // The operand needs to have object-pointer type. 1458 // TODO: should we do a contextual conversion? 1459 const ObjCObjectPointerType *pointerType = 1460 collection->getType()->getAs<ObjCObjectPointerType>(); 1461 if (!pointerType) 1462 return Diag(forLoc, diag::err_collection_expr_type) 1463 << collection->getType() << collection->getSourceRange(); 1464 1465 // Check that the operand provides 1466 // - countByEnumeratingWithState:objects:count: 1467 const ObjCObjectType *objectType = pointerType->getObjectType(); 1468 ObjCInterfaceDecl *iface = objectType->getInterface(); 1469 1470 // If we have a forward-declared type, we can't do this check. 1471 // Under ARC, it is an error not to have a forward-declared class. 1472 if (iface && 1473 RequireCompleteType(forLoc, QualType(objectType, 0), 1474 getLangOpts().ObjCAutoRefCount 1475 ? diag::err_arc_collection_forward 1476 : 0, 1477 collection)) { 1478 // Otherwise, if we have any useful type information, check that 1479 // the type declares the appropriate method. 1480 } else if (iface || !objectType->qual_empty()) { 1481 IdentifierInfo *selectorIdents[] = { 1482 &Context.Idents.get("countByEnumeratingWithState"), 1483 &Context.Idents.get("objects"), 1484 &Context.Idents.get("count") 1485 }; 1486 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1487 1488 ObjCMethodDecl *method = 0; 1489 1490 // If there's an interface, look in both the public and private APIs. 1491 if (iface) { 1492 method = iface->lookupInstanceMethod(selector); 1493 if (!method) method = iface->lookupPrivateMethod(selector); 1494 } 1495 1496 // Also check protocol qualifiers. 1497 if (!method) 1498 method = LookupMethodInQualifiedType(selector, pointerType, 1499 /*instance*/ true); 1500 1501 // If we didn't find it anywhere, give up. 1502 if (!method) { 1503 Diag(forLoc, diag::warn_collection_expr_type) 1504 << collection->getType() << selector << collection->getSourceRange(); 1505 } 1506 1507 // TODO: check for an incompatible signature? 1508 } 1509 1510 // Wrap up any cleanups in the expression. 1511 return Owned(MaybeCreateExprWithCleanups(collection)); 1512} 1513 1514StmtResult 1515Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1516 Stmt *First, Expr *collection, 1517 SourceLocation RParenLoc) { 1518 1519 ExprResult CollectionExprResult = 1520 CheckObjCForCollectionOperand(ForLoc, collection); 1521 1522 if (First) { 1523 QualType FirstType; 1524 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1525 if (!DS->isSingleDecl()) 1526 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1527 diag::err_toomany_element_decls)); 1528 1529 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1530 FirstType = D->getType(); 1531 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1532 // declare identifiers for objects having storage class 'auto' or 1533 // 'register'. 1534 if (!D->hasLocalStorage()) 1535 return StmtError(Diag(D->getLocation(), 1536 diag::err_non_variable_decl_in_for)); 1537 } else { 1538 Expr *FirstE = cast<Expr>(First); 1539 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1540 return StmtError(Diag(First->getLocStart(), 1541 diag::err_selector_element_not_lvalue) 1542 << First->getSourceRange()); 1543 1544 FirstType = static_cast<Expr*>(First)->getType(); 1545 } 1546 if (!FirstType->isDependentType() && 1547 !FirstType->isObjCObjectPointerType() && 1548 !FirstType->isBlockPointerType()) 1549 return StmtError(Diag(ForLoc, diag::err_selector_element_type) 1550 << FirstType << First->getSourceRange()); 1551 } 1552 1553 if (CollectionExprResult.isInvalid()) 1554 return StmtError(); 1555 1556 return Owned(new (Context) ObjCForCollectionStmt(First, 1557 CollectionExprResult.take(), 0, 1558 ForLoc, RParenLoc)); 1559} 1560 1561/// Finish building a variable declaration for a for-range statement. 1562/// \return true if an error occurs. 1563static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1564 SourceLocation Loc, int diag) { 1565 // Deduce the type for the iterator variable now rather than leaving it to 1566 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1567 TypeSourceInfo *InitTSI = 0; 1568 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || 1569 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) == 1570 Sema::DAR_Failed) 1571 SemaRef.Diag(Loc, diag) << Init->getType(); 1572 if (!InitTSI) { 1573 Decl->setInvalidDecl(); 1574 return true; 1575 } 1576 Decl->setTypeSourceInfo(InitTSI); 1577 Decl->setType(InitTSI->getType()); 1578 1579 // In ARC, infer lifetime. 1580 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1581 // we're doing the equivalent of fast iteration. 1582 if (SemaRef.getLangOpts().ObjCAutoRefCount && 1583 SemaRef.inferObjCARCLifetime(Decl)) 1584 Decl->setInvalidDecl(); 1585 1586 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1587 /*TypeMayContainAuto=*/false); 1588 SemaRef.FinalizeDeclaration(Decl); 1589 SemaRef.CurContext->addHiddenDecl(Decl); 1590 return false; 1591} 1592 1593namespace { 1594 1595/// Produce a note indicating which begin/end function was implicitly called 1596/// by a C++11 for-range statement. This is often not obvious from the code, 1597/// nor from the diagnostics produced when analysing the implicit expressions 1598/// required in a for-range statement. 1599void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1600 Sema::BeginEndFunction BEF) { 1601 CallExpr *CE = dyn_cast<CallExpr>(E); 1602 if (!CE) 1603 return; 1604 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1605 if (!D) 1606 return; 1607 SourceLocation Loc = D->getLocation(); 1608 1609 std::string Description; 1610 bool IsTemplate = false; 1611 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1612 Description = SemaRef.getTemplateArgumentBindingsText( 1613 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1614 IsTemplate = true; 1615 } 1616 1617 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1618 << BEF << IsTemplate << Description << E->getType(); 1619} 1620 1621/// Build a variable declaration for a for-range statement. 1622VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1623 QualType Type, const char *Name) { 1624 DeclContext *DC = SemaRef.CurContext; 1625 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1626 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1627 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1628 TInfo, SC_Auto, SC_None); 1629 Decl->setImplicit(); 1630 return Decl; 1631} 1632 1633} 1634 1635static bool ObjCEnumerationCollection(Expr *Collection) { 1636 return !Collection->isTypeDependent() 1637 && Collection->getType()->getAs<ObjCObjectPointerType>() != 0; 1638} 1639 1640/// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement. 1641/// 1642/// C++11 [stmt.ranged]: 1643/// A range-based for statement is equivalent to 1644/// 1645/// { 1646/// auto && __range = range-init; 1647/// for ( auto __begin = begin-expr, 1648/// __end = end-expr; 1649/// __begin != __end; 1650/// ++__begin ) { 1651/// for-range-declaration = *__begin; 1652/// statement 1653/// } 1654/// } 1655/// 1656/// The body of the loop is not available yet, since it cannot be analysed until 1657/// we have determined the type of the for-range-declaration. 1658StmtResult 1659Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, 1660 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1661 SourceLocation RParenLoc, BuildForRangeKind Kind) { 1662 if (!First || !Range) 1663 return StmtError(); 1664 1665 if (ObjCEnumerationCollection(Range)) 1666 return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc); 1667 1668 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1669 assert(DS && "first part of for range not a decl stmt"); 1670 1671 if (!DS->isSingleDecl()) { 1672 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1673 return StmtError(); 1674 } 1675 if (DS->getSingleDecl()->isInvalidDecl()) 1676 return StmtError(); 1677 1678 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1679 return StmtError(); 1680 1681 // Build auto && __range = range-init 1682 SourceLocation RangeLoc = Range->getLocStart(); 1683 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1684 Context.getAutoRRefDeductType(), 1685 "__range"); 1686 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1687 diag::err_for_range_deduction_failure)) 1688 return StmtError(); 1689 1690 // Claim the type doesn't contain auto: we've already done the checking. 1691 DeclGroupPtrTy RangeGroup = 1692 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1693 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1694 if (RangeDecl.isInvalid()) 1695 return StmtError(); 1696 1697 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1698 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1699 RParenLoc, Kind); 1700} 1701 1702/// \brief Create the initialization, compare, and increment steps for 1703/// the range-based for loop expression. 1704/// This function does not handle array-based for loops, 1705/// which are created in Sema::BuildCXXForRangeStmt. 1706/// 1707/// \returns a ForRangeStatus indicating success or what kind of error occurred. 1708/// BeginExpr and EndExpr are set and FRS_Success is returned on success; 1709/// CandidateSet and BEF are set and some non-success value is returned on 1710/// failure. 1711static Sema::ForRangeStatus BuildNonArrayForRange(Sema &SemaRef, Scope *S, 1712 Expr *BeginRange, Expr *EndRange, 1713 QualType RangeType, 1714 VarDecl *BeginVar, 1715 VarDecl *EndVar, 1716 SourceLocation ColonLoc, 1717 OverloadCandidateSet *CandidateSet, 1718 ExprResult *BeginExpr, 1719 ExprResult *EndExpr, 1720 Sema::BeginEndFunction *BEF) { 1721 DeclarationNameInfo BeginNameInfo( 1722 &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc); 1723 DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"), 1724 ColonLoc); 1725 1726 LookupResult BeginMemberLookup(SemaRef, BeginNameInfo, 1727 Sema::LookupMemberName); 1728 LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName); 1729 1730 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1731 // - if _RangeT is a class type, the unqualified-ids begin and end are 1732 // looked up in the scope of class _RangeT as if by class member access 1733 // lookup (3.4.5), and if either (or both) finds at least one 1734 // declaration, begin-expr and end-expr are __range.begin() and 1735 // __range.end(), respectively; 1736 SemaRef.LookupQualifiedName(BeginMemberLookup, D); 1737 SemaRef.LookupQualifiedName(EndMemberLookup, D); 1738 1739 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1740 SourceLocation RangeLoc = BeginVar->getLocation(); 1741 *BEF = BeginMemberLookup.empty() ? Sema::BEF_end : Sema::BEF_begin; 1742 1743 SemaRef.Diag(RangeLoc, diag::err_for_range_member_begin_end_mismatch) 1744 << RangeLoc << BeginRange->getType() << *BEF; 1745 return Sema::FRS_DiagnosticIssued; 1746 } 1747 } else { 1748 // - otherwise, begin-expr and end-expr are begin(__range) and 1749 // end(__range), respectively, where begin and end are looked up with 1750 // argument-dependent lookup (3.4.2). For the purposes of this name 1751 // lookup, namespace std is an associated namespace. 1752 1753 } 1754 1755 *BEF = Sema::BEF_begin; 1756 Sema::ForRangeStatus RangeStatus = 1757 SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, BeginVar, 1758 Sema::BEF_begin, BeginNameInfo, 1759 BeginMemberLookup, CandidateSet, 1760 BeginRange, BeginExpr); 1761 1762 if (RangeStatus != Sema::FRS_Success) 1763 return RangeStatus; 1764 if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc, 1765 diag::err_for_range_iter_deduction_failure)) { 1766 NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF); 1767 return Sema::FRS_DiagnosticIssued; 1768 } 1769 1770 *BEF = Sema::BEF_end; 1771 RangeStatus = 1772 SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, EndVar, 1773 Sema::BEF_end, EndNameInfo, 1774 EndMemberLookup, CandidateSet, 1775 EndRange, EndExpr); 1776 if (RangeStatus != Sema::FRS_Success) 1777 return RangeStatus; 1778 if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc, 1779 diag::err_for_range_iter_deduction_failure)) { 1780 NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF); 1781 return Sema::FRS_DiagnosticIssued; 1782 } 1783 return Sema::FRS_Success; 1784} 1785 1786/// Speculatively attempt to dereference an invalid range expression. 1787/// If the attempt fails, this function will return a valid, null StmtResult 1788/// and emit no diagnostics. 1789static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S, 1790 SourceLocation ForLoc, 1791 Stmt *LoopVarDecl, 1792 SourceLocation ColonLoc, 1793 Expr *Range, 1794 SourceLocation RangeLoc, 1795 SourceLocation RParenLoc) { 1796 // Determine whether we can rebuild the for-range statement with a 1797 // dereferenced range expression. 1798 ExprResult AdjustedRange; 1799 { 1800 Sema::SFINAETrap Trap(SemaRef); 1801 1802 AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range); 1803 if (AdjustedRange.isInvalid()) 1804 return StmtResult(); 1805 1806 StmtResult SR = 1807 SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc, 1808 AdjustedRange.get(), RParenLoc, 1809 Sema::BFRK_Check); 1810 if (SR.isInvalid()) 1811 return StmtResult(); 1812 } 1813 1814 // The attempt to dereference worked well enough that it could produce a valid 1815 // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in 1816 // case there are any other (non-fatal) problems with it. 1817 SemaRef.Diag(RangeLoc, diag::err_for_range_dereference) 1818 << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*"); 1819 return SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc, 1820 AdjustedRange.get(), RParenLoc, 1821 Sema::BFRK_Rebuild); 1822} 1823 1824/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement. 1825StmtResult 1826Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1827 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1828 Expr *Inc, Stmt *LoopVarDecl, 1829 SourceLocation RParenLoc, BuildForRangeKind Kind) { 1830 Scope *S = getCurScope(); 1831 1832 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1833 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1834 QualType RangeVarType = RangeVar->getType(); 1835 1836 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1837 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1838 1839 StmtResult BeginEndDecl = BeginEnd; 1840 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1841 1842 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1843 SourceLocation RangeLoc = RangeVar->getLocation(); 1844 1845 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); 1846 1847 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1848 VK_LValue, ColonLoc); 1849 if (BeginRangeRef.isInvalid()) 1850 return StmtError(); 1851 1852 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1853 VK_LValue, ColonLoc); 1854 if (EndRangeRef.isInvalid()) 1855 return StmtError(); 1856 1857 QualType AutoType = Context.getAutoDeductType(); 1858 Expr *Range = RangeVar->getInit(); 1859 if (!Range) 1860 return StmtError(); 1861 QualType RangeType = Range->getType(); 1862 1863 if (RequireCompleteType(RangeLoc, RangeType, 1864 diag::err_for_range_incomplete_type)) 1865 return StmtError(); 1866 1867 // Build auto __begin = begin-expr, __end = end-expr. 1868 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1869 "__begin"); 1870 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1871 "__end"); 1872 1873 // Build begin-expr and end-expr and attach to __begin and __end variables. 1874 ExprResult BeginExpr, EndExpr; 1875 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1876 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1877 // __range + __bound, respectively, where __bound is the array bound. If 1878 // _RangeT is an array of unknown size or an array of incomplete type, 1879 // the program is ill-formed; 1880 1881 // begin-expr is __range. 1882 BeginExpr = BeginRangeRef; 1883 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, 1884 diag::err_for_range_iter_deduction_failure)) { 1885 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1886 return StmtError(); 1887 } 1888 1889 // Find the array bound. 1890 ExprResult BoundExpr; 1891 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1892 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1893 Context.getPointerDiffType(), 1894 RangeLoc)); 1895 else if (const VariableArrayType *VAT = 1896 dyn_cast<VariableArrayType>(UnqAT)) 1897 BoundExpr = VAT->getSizeExpr(); 1898 else { 1899 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1900 // UnqAT is not incomplete and Range is not type-dependent. 1901 llvm_unreachable("Unexpected array type in for-range"); 1902 } 1903 1904 // end-expr is __range + __bound. 1905 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), 1906 BoundExpr.get()); 1907 if (EndExpr.isInvalid()) 1908 return StmtError(); 1909 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1910 diag::err_for_range_iter_deduction_failure)) { 1911 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1912 return StmtError(); 1913 } 1914 } else { 1915 OverloadCandidateSet CandidateSet(RangeLoc); 1916 Sema::BeginEndFunction BEFFailure; 1917 ForRangeStatus RangeStatus = 1918 BuildNonArrayForRange(*this, S, BeginRangeRef.get(), 1919 EndRangeRef.get(), RangeType, 1920 BeginVar, EndVar, ColonLoc, &CandidateSet, 1921 &BeginExpr, &EndExpr, &BEFFailure); 1922 1923 // If building the range failed, try dereferencing the range expression 1924 // unless a diagnostic was issued or the end function is problematic. 1925 if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction && 1926 BEFFailure == BEF_begin) { 1927 StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc, 1928 LoopVarDecl, ColonLoc, 1929 Range, RangeLoc, 1930 RParenLoc); 1931 if (SR.isInvalid() || SR.isUsable()) 1932 return SR; 1933 } 1934 1935 // Otherwise, emit diagnostics if we haven't already. 1936 if (RangeStatus == FRS_NoViableFunction) { 1937 Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get(); 1938 Diag(Range->getLocStart(), diag::err_for_range_invalid) 1939 << RangeLoc << Range->getType() << BEFFailure; 1940 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 1941 llvm::makeArrayRef(&Range, /*NumArgs=*/1)); 1942 } 1943 // Return an error if no fix was discovered. 1944 if (RangeStatus != FRS_Success) 1945 return StmtError(); 1946 } 1947 1948 assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() && 1949 "invalid range expression in for loop"); 1950 1951 // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same. 1952 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1953 if (!Context.hasSameType(BeginType, EndType)) { 1954 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1955 << BeginType << EndType; 1956 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1957 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1958 } 1959 1960 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1961 // Claim the type doesn't contain auto: we've already done the checking. 1962 DeclGroupPtrTy BeginEndGroup = 1963 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1964 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1965 1966 const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); 1967 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1968 VK_LValue, ColonLoc); 1969 if (BeginRef.isInvalid()) 1970 return StmtError(); 1971 1972 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1973 VK_LValue, ColonLoc); 1974 if (EndRef.isInvalid()) 1975 return StmtError(); 1976 1977 // Build and check __begin != __end expression. 1978 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1979 BeginRef.get(), EndRef.get()); 1980 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1981 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1982 if (NotEqExpr.isInvalid()) { 1983 Diag(RangeLoc, diag::note_for_range_invalid_iterator) 1984 << RangeLoc << 0 << BeginRangeRef.get()->getType(); 1985 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1986 if (!Context.hasSameType(BeginType, EndType)) 1987 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1988 return StmtError(); 1989 } 1990 1991 // Build and check ++__begin expression. 1992 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1993 VK_LValue, ColonLoc); 1994 if (BeginRef.isInvalid()) 1995 return StmtError(); 1996 1997 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1998 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1999 if (IncrExpr.isInvalid()) { 2000 Diag(RangeLoc, diag::note_for_range_invalid_iterator) 2001 << RangeLoc << 2 << BeginRangeRef.get()->getType() ; 2002 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 2003 return StmtError(); 2004 } 2005 2006 // Build and check *__begin expression. 2007 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 2008 VK_LValue, ColonLoc); 2009 if (BeginRef.isInvalid()) 2010 return StmtError(); 2011 2012 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 2013 if (DerefExpr.isInvalid()) { 2014 Diag(RangeLoc, diag::note_for_range_invalid_iterator) 2015 << RangeLoc << 1 << BeginRangeRef.get()->getType(); 2016 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 2017 return StmtError(); 2018 } 2019 2020 // Attach *__begin as initializer for VD. Don't touch it if we're just 2021 // trying to determine whether this would be a valid range. 2022 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) { 2023 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 2024 /*TypeMayContainAuto=*/true); 2025 if (LoopVar->isInvalidDecl()) 2026 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 2027 } 2028 } else { 2029 // The range is implicitly used as a placeholder when it is dependent. 2030 RangeVar->setUsed(); 2031 } 2032 2033 // Don't bother to actually allocate the result if we're just trying to 2034 // determine whether it would be valid. 2035 if (Kind == BFRK_Check) 2036 return StmtResult(); 2037 2038 return Owned(new (Context) CXXForRangeStmt(RangeDS, 2039 cast_or_null<DeclStmt>(BeginEndDecl.get()), 2040 NotEqExpr.take(), IncrExpr.take(), 2041 LoopVarDS, /*Body=*/0, ForLoc, 2042 ColonLoc, RParenLoc)); 2043} 2044 2045/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach 2046/// statement. 2047StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) { 2048 if (!S || !B) 2049 return StmtError(); 2050 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S); 2051 2052 ForStmt->setBody(B); 2053 return S; 2054} 2055 2056/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 2057/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 2058/// body cannot be performed until after the type of the range variable is 2059/// determined. 2060StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 2061 if (!S || !B) 2062 return StmtError(); 2063 2064 if (isa<ObjCForCollectionStmt>(S)) 2065 return FinishObjCForCollectionStmt(S, B); 2066 2067 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); 2068 ForStmt->setBody(B); 2069 2070 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, 2071 diag::warn_empty_range_based_for_body); 2072 2073 return S; 2074} 2075 2076StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 2077 SourceLocation LabelLoc, 2078 LabelDecl *TheDecl) { 2079 getCurFunction()->setHasBranchIntoScope(); 2080 TheDecl->setUsed(); 2081 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 2082} 2083 2084StmtResult 2085Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 2086 Expr *E) { 2087 // Convert operand to void* 2088 if (!E->isTypeDependent()) { 2089 QualType ETy = E->getType(); 2090 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 2091 ExprResult ExprRes = Owned(E); 2092 AssignConvertType ConvTy = 2093 CheckSingleAssignmentConstraints(DestTy, ExprRes); 2094 if (ExprRes.isInvalid()) 2095 return StmtError(); 2096 E = ExprRes.take(); 2097 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 2098 return StmtError(); 2099 E = MaybeCreateExprWithCleanups(E); 2100 } 2101 2102 getCurFunction()->setHasIndirectGoto(); 2103 2104 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 2105} 2106 2107StmtResult 2108Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 2109 Scope *S = CurScope->getContinueParent(); 2110 if (!S) { 2111 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 2112 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 2113 } 2114 2115 return Owned(new (Context) ContinueStmt(ContinueLoc)); 2116} 2117 2118StmtResult 2119Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 2120 Scope *S = CurScope->getBreakParent(); 2121 if (!S) { 2122 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 2123 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 2124 } 2125 2126 return Owned(new (Context) BreakStmt(BreakLoc)); 2127} 2128 2129/// \brief Determine whether the given expression is a candidate for 2130/// copy elision in either a return statement or a throw expression. 2131/// 2132/// \param ReturnType If we're determining the copy elision candidate for 2133/// a return statement, this is the return type of the function. If we're 2134/// determining the copy elision candidate for a throw expression, this will 2135/// be a NULL type. 2136/// 2137/// \param E The expression being returned from the function or block, or 2138/// being thrown. 2139/// 2140/// \param AllowFunctionParameter Whether we allow function parameters to 2141/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 2142/// we re-use this logic to determine whether we should try to move as part of 2143/// a return or throw (which does allow function parameters). 2144/// 2145/// \returns The NRVO candidate variable, if the return statement may use the 2146/// NRVO, or NULL if there is no such candidate. 2147const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 2148 Expr *E, 2149 bool AllowFunctionParameter) { 2150 QualType ExprType = E->getType(); 2151 // - in a return statement in a function with ... 2152 // ... a class return type ... 2153 if (!ReturnType.isNull()) { 2154 if (!ReturnType->isRecordType()) 2155 return 0; 2156 // ... the same cv-unqualified type as the function return type ... 2157 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 2158 return 0; 2159 } 2160 2161 // ... the expression is the name of a non-volatile automatic object 2162 // (other than a function or catch-clause parameter)) ... 2163 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 2164 if (!DR || DR->refersToEnclosingLocal()) 2165 return 0; 2166 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 2167 if (!VD) 2168 return 0; 2169 2170 // ...object (other than a function or catch-clause parameter)... 2171 if (VD->getKind() != Decl::Var && 2172 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) 2173 return 0; 2174 if (VD->isExceptionVariable()) return 0; 2175 2176 // ...automatic... 2177 if (!VD->hasLocalStorage()) return 0; 2178 2179 // ...non-volatile... 2180 if (VD->getType().isVolatileQualified()) return 0; 2181 if (VD->getType()->isReferenceType()) return 0; 2182 2183 // __block variables can't be allocated in a way that permits NRVO. 2184 if (VD->hasAttr<BlocksAttr>()) return 0; 2185 2186 // Variables with higher required alignment than their type's ABI 2187 // alignment cannot use NRVO. 2188 if (VD->hasAttr<AlignedAttr>() && 2189 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) 2190 return 0; 2191 2192 return VD; 2193} 2194 2195/// \brief Perform the initialization of a potentially-movable value, which 2196/// is the result of return value. 2197/// 2198/// This routine implements C++0x [class.copy]p33, which attempts to treat 2199/// returned lvalues as rvalues in certain cases (to prefer move construction), 2200/// then falls back to treating them as lvalues if that failed. 2201ExprResult 2202Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 2203 const VarDecl *NRVOCandidate, 2204 QualType ResultType, 2205 Expr *Value, 2206 bool AllowNRVO) { 2207 // C++0x [class.copy]p33: 2208 // When the criteria for elision of a copy operation are met or would 2209 // be met save for the fact that the source object is a function 2210 // parameter, and the object to be copied is designated by an lvalue, 2211 // overload resolution to select the constructor for the copy is first 2212 // performed as if the object were designated by an rvalue. 2213 ExprResult Res = ExprError(); 2214 if (AllowNRVO && 2215 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 2216 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 2217 Value->getType(), CK_NoOp, Value, VK_XValue); 2218 2219 Expr *InitExpr = &AsRvalue; 2220 InitializationKind Kind 2221 = InitializationKind::CreateCopy(Value->getLocStart(), 2222 Value->getLocStart()); 2223 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 2224 2225 // [...] If overload resolution fails, or if the type of the first 2226 // parameter of the selected constructor is not an rvalue reference 2227 // to the object's type (possibly cv-qualified), overload resolution 2228 // is performed again, considering the object as an lvalue. 2229 if (Seq) { 2230 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 2231 StepEnd = Seq.step_end(); 2232 Step != StepEnd; ++Step) { 2233 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 2234 continue; 2235 2236 CXXConstructorDecl *Constructor 2237 = cast<CXXConstructorDecl>(Step->Function.Function); 2238 2239 const RValueReferenceType *RRefType 2240 = Constructor->getParamDecl(0)->getType() 2241 ->getAs<RValueReferenceType>(); 2242 2243 // If we don't meet the criteria, break out now. 2244 if (!RRefType || 2245 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 2246 Context.getTypeDeclType(Constructor->getParent()))) 2247 break; 2248 2249 // Promote "AsRvalue" to the heap, since we now need this 2250 // expression node to persist. 2251 Value = ImplicitCastExpr::Create(Context, Value->getType(), 2252 CK_NoOp, Value, 0, VK_XValue); 2253 2254 // Complete type-checking the initialization of the return type 2255 // using the constructor we found. 2256 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 2257 } 2258 } 2259 } 2260 2261 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 2262 // above, or overload resolution failed. Either way, we need to try 2263 // (again) now with the return value expression as written. 2264 if (Res.isInvalid()) 2265 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 2266 2267 return Res; 2268} 2269 2270/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements 2271/// for capturing scopes. 2272/// 2273StmtResult 2274Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2275 // If this is the first return we've seen, infer the return type. 2276 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those 2277 // rules which allows multiple return statements. 2278 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); 2279 QualType FnRetType = CurCap->ReturnType; 2280 2281 // For blocks/lambdas with implicit return types, we check each return 2282 // statement individually, and deduce the common return type when the block 2283 // or lambda is completed. 2284 if (CurCap->HasImplicitReturnType) { 2285 if (RetValExp && !isa<InitListExpr>(RetValExp)) { 2286 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 2287 if (Result.isInvalid()) 2288 return StmtError(); 2289 RetValExp = Result.take(); 2290 2291 if (!RetValExp->isTypeDependent()) 2292 FnRetType = RetValExp->getType(); 2293 else 2294 FnRetType = CurCap->ReturnType = Context.DependentTy; 2295 } else { 2296 if (RetValExp) { 2297 // C++11 [expr.lambda.prim]p4 bans inferring the result from an 2298 // initializer list, because it is not an expression (even 2299 // though we represent it as one). We still deduce 'void'. 2300 Diag(ReturnLoc, diag::err_lambda_return_init_list) 2301 << RetValExp->getSourceRange(); 2302 } 2303 2304 FnRetType = Context.VoidTy; 2305 } 2306 2307 // Although we'll properly infer the type of the block once it's completed, 2308 // make sure we provide a return type now for better error recovery. 2309 if (CurCap->ReturnType.isNull()) 2310 CurCap->ReturnType = FnRetType; 2311 } 2312 assert(!FnRetType.isNull()); 2313 2314 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { 2315 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 2316 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); 2317 return StmtError(); 2318 } 2319 } else { 2320 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap); 2321 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){ 2322 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); 2323 return StmtError(); 2324 } 2325 } 2326 2327 // Otherwise, verify that this result type matches the previous one. We are 2328 // pickier with blocks than for normal functions because we don't have GCC 2329 // compatibility to worry about here. 2330 const VarDecl *NRVOCandidate = 0; 2331 if (FnRetType->isDependentType()) { 2332 // Delay processing for now. TODO: there are lots of dependent 2333 // types we can conclusively prove aren't void. 2334 } else if (FnRetType->isVoidType()) { 2335 if (RetValExp && !isa<InitListExpr>(RetValExp) && 2336 !(getLangOpts().CPlusPlus && 2337 (RetValExp->isTypeDependent() || 2338 RetValExp->getType()->isVoidType()))) { 2339 if (!getLangOpts().CPlusPlus && 2340 RetValExp->getType()->isVoidType()) 2341 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; 2342 else { 2343 Diag(ReturnLoc, diag::err_return_block_has_expr); 2344 RetValExp = 0; 2345 } 2346 } 2347 } else if (!RetValExp) { 2348 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 2349 } else if (!RetValExp->isTypeDependent()) { 2350 // we have a non-void block with an expression, continue checking 2351 2352 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2353 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2354 // function return. 2355 2356 // In C++ the return statement is handled via a copy initialization. 2357 // the C version of which boils down to CheckSingleAssignmentConstraints. 2358 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2359 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2360 FnRetType, 2361 NRVOCandidate != 0); 2362 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2363 FnRetType, RetValExp); 2364 if (Res.isInvalid()) { 2365 // FIXME: Cleanup temporaries here, anyway? 2366 return StmtError(); 2367 } 2368 RetValExp = Res.take(); 2369 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2370 } 2371 2372 if (RetValExp) { 2373 CheckImplicitConversions(RetValExp, ReturnLoc); 2374 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2375 } 2376 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 2377 NRVOCandidate); 2378 2379 // If we need to check for the named return value optimization, 2380 // or if we need to infer the return type, 2381 // save the return statement in our scope for later processing. 2382 if (CurCap->HasImplicitReturnType || 2383 (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2384 !CurContext->isDependentContext())) 2385 FunctionScopes.back()->Returns.push_back(Result); 2386 2387 return Owned(Result); 2388} 2389 2390StmtResult 2391Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2392 // Check for unexpanded parameter packs. 2393 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 2394 return StmtError(); 2395 2396 if (isa<CapturingScopeInfo>(getCurFunction())) 2397 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); 2398 2399 QualType FnRetType; 2400 QualType RelatedRetType; 2401 if (const FunctionDecl *FD = getCurFunctionDecl()) { 2402 FnRetType = FD->getResultType(); 2403 if (FD->hasAttr<NoReturnAttr>() || 2404 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 2405 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 2406 << FD->getDeclName(); 2407 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2408 FnRetType = MD->getResultType(); 2409 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 2410 // In the implementation of a method with a related return type, the 2411 // type used to type-check the validity of return statements within the 2412 // method body is a pointer to the type of the class being implemented. 2413 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 2414 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); 2415 } 2416 } else // If we don't have a function/method context, bail. 2417 return StmtError(); 2418 2419 ReturnStmt *Result = 0; 2420 if (FnRetType->isVoidType()) { 2421 if (RetValExp) { 2422 if (isa<InitListExpr>(RetValExp)) { 2423 // We simply never allow init lists as the return value of void 2424 // functions. This is compatible because this was never allowed before, 2425 // so there's no legacy code to deal with. 2426 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2427 int FunctionKind = 0; 2428 if (isa<ObjCMethodDecl>(CurDecl)) 2429 FunctionKind = 1; 2430 else if (isa<CXXConstructorDecl>(CurDecl)) 2431 FunctionKind = 2; 2432 else if (isa<CXXDestructorDecl>(CurDecl)) 2433 FunctionKind = 3; 2434 2435 Diag(ReturnLoc, diag::err_return_init_list) 2436 << CurDecl->getDeclName() << FunctionKind 2437 << RetValExp->getSourceRange(); 2438 2439 // Drop the expression. 2440 RetValExp = 0; 2441 } else if (!RetValExp->isTypeDependent()) { 2442 // C99 6.8.6.4p1 (ext_ since GCC warns) 2443 unsigned D = diag::ext_return_has_expr; 2444 if (RetValExp->getType()->isVoidType()) 2445 D = diag::ext_return_has_void_expr; 2446 else { 2447 ExprResult Result = Owned(RetValExp); 2448 Result = IgnoredValueConversions(Result.take()); 2449 if (Result.isInvalid()) 2450 return StmtError(); 2451 RetValExp = Result.take(); 2452 RetValExp = ImpCastExprToType(RetValExp, 2453 Context.VoidTy, CK_ToVoid).take(); 2454 } 2455 2456 // return (some void expression); is legal in C++. 2457 if (D != diag::ext_return_has_void_expr || 2458 !getLangOpts().CPlusPlus) { 2459 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2460 2461 int FunctionKind = 0; 2462 if (isa<ObjCMethodDecl>(CurDecl)) 2463 FunctionKind = 1; 2464 else if (isa<CXXConstructorDecl>(CurDecl)) 2465 FunctionKind = 2; 2466 else if (isa<CXXDestructorDecl>(CurDecl)) 2467 FunctionKind = 3; 2468 2469 Diag(ReturnLoc, D) 2470 << CurDecl->getDeclName() << FunctionKind 2471 << RetValExp->getSourceRange(); 2472 } 2473 } 2474 2475 if (RetValExp) { 2476 CheckImplicitConversions(RetValExp, ReturnLoc); 2477 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2478 } 2479 } 2480 2481 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 2482 } else if (!RetValExp && !FnRetType->isDependentType()) { 2483 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 2484 // C99 6.8.6.4p1 (ext_ since GCC warns) 2485 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; 2486 2487 if (FunctionDecl *FD = getCurFunctionDecl()) 2488 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 2489 else 2490 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 2491 Result = new (Context) ReturnStmt(ReturnLoc); 2492 } else { 2493 const VarDecl *NRVOCandidate = 0; 2494 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 2495 // we have a non-void function with an expression, continue checking 2496 2497 if (!RelatedRetType.isNull()) { 2498 // If we have a related result type, perform an extra conversion here. 2499 // FIXME: The diagnostics here don't really describe what is happening. 2500 InitializedEntity Entity = 2501 InitializedEntity::InitializeTemporary(RelatedRetType); 2502 2503 ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), 2504 RetValExp); 2505 if (Res.isInvalid()) { 2506 // FIXME: Cleanup temporaries here, anyway? 2507 return StmtError(); 2508 } 2509 RetValExp = Res.takeAs<Expr>(); 2510 } 2511 2512 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2513 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2514 // function return. 2515 2516 // In C++ the return statement is handled via a copy initialization, 2517 // the C version of which boils down to CheckSingleAssignmentConstraints. 2518 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2519 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2520 FnRetType, 2521 NRVOCandidate != 0); 2522 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2523 FnRetType, RetValExp); 2524 if (Res.isInvalid()) { 2525 // FIXME: Cleanup temporaries here, anyway? 2526 return StmtError(); 2527 } 2528 2529 RetValExp = Res.takeAs<Expr>(); 2530 if (RetValExp) 2531 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2532 } 2533 2534 if (RetValExp) { 2535 CheckImplicitConversions(RetValExp, ReturnLoc); 2536 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2537 } 2538 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 2539 } 2540 2541 // If we need to check for the named return value optimization, save the 2542 // return statement in our scope for later processing. 2543 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2544 !CurContext->isDependentContext()) 2545 FunctionScopes.back()->Returns.push_back(Result); 2546 2547 return Owned(Result); 2548} 2549 2550StmtResult 2551Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2552 SourceLocation RParen, Decl *Parm, 2553 Stmt *Body) { 2554 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2555 if (Var && Var->isInvalidDecl()) 2556 return StmtError(); 2557 2558 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2559} 2560 2561StmtResult 2562Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2563 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2564} 2565 2566StmtResult 2567Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2568 MultiStmtArg CatchStmts, Stmt *Finally) { 2569 if (!getLangOpts().ObjCExceptions) 2570 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2571 2572 getCurFunction()->setHasBranchProtectedScope(); 2573 unsigned NumCatchStmts = CatchStmts.size(); 2574 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2575 CatchStmts.data(), 2576 NumCatchStmts, 2577 Finally)); 2578} 2579 2580StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) { 2581 if (Throw) { 2582 ExprResult Result = DefaultLvalueConversion(Throw); 2583 if (Result.isInvalid()) 2584 return StmtError(); 2585 2586 Throw = MaybeCreateExprWithCleanups(Result.take()); 2587 QualType ThrowType = Throw->getType(); 2588 // Make sure the expression type is an ObjC pointer or "void *". 2589 if (!ThrowType->isDependentType() && 2590 !ThrowType->isObjCObjectPointerType()) { 2591 const PointerType *PT = ThrowType->getAs<PointerType>(); 2592 if (!PT || !PT->getPointeeType()->isVoidType()) 2593 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2594 << Throw->getType() << Throw->getSourceRange()); 2595 } 2596 } 2597 2598 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2599} 2600 2601StmtResult 2602Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2603 Scope *CurScope) { 2604 if (!getLangOpts().ObjCExceptions) 2605 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2606 2607 if (!Throw) { 2608 // @throw without an expression designates a rethrow (which much occur 2609 // in the context of an @catch clause). 2610 Scope *AtCatchParent = CurScope; 2611 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2612 AtCatchParent = AtCatchParent->getParent(); 2613 if (!AtCatchParent) 2614 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2615 } 2616 return BuildObjCAtThrowStmt(AtLoc, Throw); 2617} 2618 2619ExprResult 2620Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2621 ExprResult result = DefaultLvalueConversion(operand); 2622 if (result.isInvalid()) 2623 return ExprError(); 2624 operand = result.take(); 2625 2626 // Make sure the expression type is an ObjC pointer or "void *". 2627 QualType type = operand->getType(); 2628 if (!type->isDependentType() && 2629 !type->isObjCObjectPointerType()) { 2630 const PointerType *pointerType = type->getAs<PointerType>(); 2631 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2632 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2633 << type << operand->getSourceRange(); 2634 } 2635 2636 // The operand to @synchronized is a full-expression. 2637 return MaybeCreateExprWithCleanups(operand); 2638} 2639 2640StmtResult 2641Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2642 Stmt *SyncBody) { 2643 // We can't jump into or indirect-jump out of a @synchronized block. 2644 getCurFunction()->setHasBranchProtectedScope(); 2645 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2646} 2647 2648/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2649/// and creates a proper catch handler from them. 2650StmtResult 2651Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2652 Stmt *HandlerBlock) { 2653 // There's nothing to test that ActOnExceptionDecl didn't already test. 2654 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2655 cast_or_null<VarDecl>(ExDecl), 2656 HandlerBlock)); 2657} 2658 2659StmtResult 2660Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2661 getCurFunction()->setHasBranchProtectedScope(); 2662 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2663} 2664 2665namespace { 2666 2667class TypeWithHandler { 2668 QualType t; 2669 CXXCatchStmt *stmt; 2670public: 2671 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2672 : t(type), stmt(statement) {} 2673 2674 // An arbitrary order is fine as long as it places identical 2675 // types next to each other. 2676 bool operator<(const TypeWithHandler &y) const { 2677 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2678 return true; 2679 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2680 return false; 2681 else 2682 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2683 } 2684 2685 bool operator==(const TypeWithHandler& other) const { 2686 return t == other.t; 2687 } 2688 2689 CXXCatchStmt *getCatchStmt() const { return stmt; } 2690 SourceLocation getTypeSpecStartLoc() const { 2691 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2692 } 2693}; 2694 2695} 2696 2697/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2698/// handlers and creates a try statement from them. 2699StmtResult 2700Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2701 MultiStmtArg RawHandlers) { 2702 // Don't report an error if 'try' is used in system headers. 2703 if (!getLangOpts().CXXExceptions && 2704 !getSourceManager().isInSystemHeader(TryLoc)) 2705 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2706 2707 unsigned NumHandlers = RawHandlers.size(); 2708 assert(NumHandlers > 0 && 2709 "The parser shouldn't call this if there are no handlers."); 2710 Stmt **Handlers = RawHandlers.data(); 2711 2712 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2713 2714 for (unsigned i = 0; i < NumHandlers; ++i) { 2715 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 2716 if (!Handler->getExceptionDecl()) { 2717 if (i < NumHandlers - 1) 2718 return StmtError(Diag(Handler->getLocStart(), 2719 diag::err_early_catch_all)); 2720 2721 continue; 2722 } 2723 2724 const QualType CaughtType = Handler->getCaughtType(); 2725 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2726 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2727 } 2728 2729 // Detect handlers for the same type as an earlier one. 2730 if (NumHandlers > 1) { 2731 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2732 2733 TypeWithHandler prev = TypesWithHandlers[0]; 2734 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2735 TypeWithHandler curr = TypesWithHandlers[i]; 2736 2737 if (curr == prev) { 2738 Diag(curr.getTypeSpecStartLoc(), 2739 diag::warn_exception_caught_by_earlier_handler) 2740 << curr.getCatchStmt()->getCaughtType().getAsString(); 2741 Diag(prev.getTypeSpecStartLoc(), 2742 diag::note_previous_exception_handler) 2743 << prev.getCatchStmt()->getCaughtType().getAsString(); 2744 } 2745 2746 prev = curr; 2747 } 2748 } 2749 2750 getCurFunction()->setHasBranchProtectedScope(); 2751 2752 // FIXME: We should detect handlers that cannot catch anything because an 2753 // earlier handler catches a superclass. Need to find a method that is not 2754 // quadratic for this. 2755 // Neither of these are explicitly forbidden, but every compiler detects them 2756 // and warns. 2757 2758 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2759 Handlers, NumHandlers)); 2760} 2761 2762StmtResult 2763Sema::ActOnSEHTryBlock(bool IsCXXTry, 2764 SourceLocation TryLoc, 2765 Stmt *TryBlock, 2766 Stmt *Handler) { 2767 assert(TryBlock && Handler); 2768 2769 getCurFunction()->setHasBranchProtectedScope(); 2770 2771 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2772} 2773 2774StmtResult 2775Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2776 Expr *FilterExpr, 2777 Stmt *Block) { 2778 assert(FilterExpr && Block); 2779 2780 if(!FilterExpr->getType()->isIntegerType()) { 2781 return StmtError(Diag(FilterExpr->getExprLoc(), 2782 diag::err_filter_expression_integral) 2783 << FilterExpr->getType()); 2784 } 2785 2786 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2787} 2788 2789StmtResult 2790Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2791 Stmt *Block) { 2792 assert(Block); 2793 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2794} 2795 2796StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, 2797 bool IsIfExists, 2798 NestedNameSpecifierLoc QualifierLoc, 2799 DeclarationNameInfo NameInfo, 2800 Stmt *Nested) 2801{ 2802 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, 2803 QualifierLoc, NameInfo, 2804 cast<CompoundStmt>(Nested)); 2805} 2806 2807 2808StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, 2809 bool IsIfExists, 2810 CXXScopeSpec &SS, 2811 UnqualifiedId &Name, 2812 Stmt *Nested) { 2813 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, 2814 SS.getWithLocInContext(Context), 2815 GetNameFromUnqualifiedId(Name), 2816 Nested); 2817} 2818