SemaStmt.cpp revision e696b6924d14b0e0590b5d923ca1646e6f67ac40
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 // Okay, we have an unused result. Depending on what the base expression is, 164 // we might want to make a more specific diagnostic. Check for one of these 165 // cases now. 166 unsigned DiagID = diag::warn_unused_expr; 167 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 168 E = Temps->getSubExpr(); 169 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 170 E = TempExpr->getSubExpr(); 171 172 if (DiagnoseUnusedComparison(*this, E)) 173 return; 174 175 E = WarnExpr; 176 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 177 if (E->getType()->isVoidType()) 178 return; 179 180 // If the callee has attribute pure, const, or warn_unused_result, warn with 181 // a more specific message to make it clear what is happening. 182 if (const Decl *FD = CE->getCalleeDecl()) { 183 if (FD->getAttr<WarnUnusedResultAttr>()) { 184 Diag(Loc, diag::warn_unused_result) << R1 << R2; 185 return; 186 } 187 if (FD->getAttr<PureAttr>()) { 188 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 189 return; 190 } 191 if (FD->getAttr<ConstAttr>()) { 192 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 193 return; 194 } 195 } 196 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 197 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { 198 Diag(Loc, diag::err_arc_unused_init_message) << R1; 199 return; 200 } 201 const ObjCMethodDecl *MD = ME->getMethodDecl(); 202 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 203 Diag(Loc, diag::warn_unused_result) << R1 << R2; 204 return; 205 } 206 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 207 const Expr *Source = POE->getSyntacticForm(); 208 if (isa<ObjCSubscriptRefExpr>(Source)) 209 DiagID = diag::warn_unused_container_subscript_expr; 210 else 211 DiagID = diag::warn_unused_property_expr; 212 } else if (const CXXFunctionalCastExpr *FC 213 = dyn_cast<CXXFunctionalCastExpr>(E)) { 214 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 215 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 216 return; 217 } 218 // Diagnose "(void*) blah" as a typo for "(void) blah". 219 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 220 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 221 QualType T = TI->getType(); 222 223 // We really do want to use the non-canonical type here. 224 if (T == Context.VoidPtrTy) { 225 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 226 227 Diag(Loc, diag::warn_unused_voidptr) 228 << FixItHint::CreateRemoval(TL.getStarLoc()); 229 return; 230 } 231 } 232 233 if (E->isGLValue() && E->getType().isVolatileQualified()) { 234 Diag(Loc, diag::warn_unused_volatile) << R1 << R2; 235 return; 236 } 237 238 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 239} 240 241void Sema::ActOnStartOfCompoundStmt() { 242 PushCompoundScope(); 243} 244 245void Sema::ActOnFinishOfCompoundStmt() { 246 PopCompoundScope(); 247} 248 249sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { 250 return getCurFunction()->CompoundScopes.back(); 251} 252 253StmtResult 254Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 255 MultiStmtArg elts, bool isStmtExpr) { 256 unsigned NumElts = elts.size(); 257 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 258 // If we're in C89 mode, check that we don't have any decls after stmts. If 259 // so, emit an extension diagnostic. 260 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { 261 // Note that __extension__ can be around a decl. 262 unsigned i = 0; 263 // Skip over all declarations. 264 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 265 /*empty*/; 266 267 // We found the end of the list or a statement. Scan for another declstmt. 268 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 269 /*empty*/; 270 271 if (i != NumElts) { 272 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 273 Diag(D->getLocation(), diag::ext_mixed_decls_code); 274 } 275 } 276 // Warn about unused expressions in statements. 277 for (unsigned i = 0; i != NumElts; ++i) { 278 // Ignore statements that are last in a statement expression. 279 if (isStmtExpr && i == NumElts - 1) 280 continue; 281 282 DiagnoseUnusedExprResult(Elts[i]); 283 } 284 285 // Check for suspicious empty body (null statement) in `for' and `while' 286 // statements. Don't do anything for template instantiations, this just adds 287 // noise. 288 if (NumElts != 0 && !CurrentInstantiationScope && 289 getCurCompoundScope().HasEmptyLoopBodies) { 290 for (unsigned i = 0; i != NumElts - 1; ++i) 291 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); 292 } 293 294 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 295} 296 297StmtResult 298Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 299 SourceLocation DotDotDotLoc, Expr *RHSVal, 300 SourceLocation ColonLoc) { 301 assert((LHSVal != 0) && "missing expression in case statement"); 302 303 if (getCurFunction()->SwitchStack.empty()) { 304 Diag(CaseLoc, diag::err_case_not_in_switch); 305 return StmtError(); 306 } 307 308 if (!getLangOpts().CPlusPlus0x) { 309 // C99 6.8.4.2p3: The expression shall be an integer constant. 310 // However, GCC allows any evaluatable integer expression. 311 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { 312 LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); 313 if (!LHSVal) 314 return StmtError(); 315 } 316 317 // GCC extension: The expression shall be an integer constant. 318 319 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { 320 RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); 321 // Recover from an error by just forgetting about it. 322 } 323 } 324 325 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 326 ColonLoc); 327 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 328 return Owned(CS); 329} 330 331/// ActOnCaseStmtBody - This installs a statement as the body of a case. 332void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 333 DiagnoseUnusedExprResult(SubStmt); 334 335 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 336 CS->setSubStmt(SubStmt); 337} 338 339StmtResult 340Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 341 Stmt *SubStmt, Scope *CurScope) { 342 DiagnoseUnusedExprResult(SubStmt); 343 344 if (getCurFunction()->SwitchStack.empty()) { 345 Diag(DefaultLoc, diag::err_default_not_in_switch); 346 return Owned(SubStmt); 347 } 348 349 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 350 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 351 return Owned(DS); 352} 353 354StmtResult 355Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 356 SourceLocation ColonLoc, Stmt *SubStmt) { 357 // If the label was multiply defined, reject it now. 358 if (TheDecl->getStmt()) { 359 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 360 Diag(TheDecl->getLocation(), diag::note_previous_definition); 361 return Owned(SubStmt); 362 } 363 364 // Otherwise, things are good. Fill in the declaration and return it. 365 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 366 TheDecl->setStmt(LS); 367 if (!TheDecl->isGnuLocal()) 368 TheDecl->setLocation(IdentLoc); 369 return Owned(LS); 370} 371 372StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, 373 ArrayRef<const Attr*> Attrs, 374 Stmt *SubStmt) { 375 // Fill in the declaration and return it. 376 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt); 377 return Owned(LS); 378} 379 380StmtResult 381Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 382 Stmt *thenStmt, SourceLocation ElseLoc, 383 Stmt *elseStmt) { 384 ExprResult CondResult(CondVal.release()); 385 386 VarDecl *ConditionVar = 0; 387 if (CondVar) { 388 ConditionVar = cast<VarDecl>(CondVar); 389 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 390 if (CondResult.isInvalid()) 391 return StmtError(); 392 } 393 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 394 if (!ConditionExpr) 395 return StmtError(); 396 397 DiagnoseUnusedExprResult(thenStmt); 398 399 if (!elseStmt) { 400 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, 401 diag::warn_empty_if_body); 402 } 403 404 DiagnoseUnusedExprResult(elseStmt); 405 406 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 407 thenStmt, ElseLoc, elseStmt)); 408} 409 410/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 411/// the specified width and sign. If an overflow occurs, detect it and emit 412/// the specified diagnostic. 413void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 414 unsigned NewWidth, bool NewSign, 415 SourceLocation Loc, 416 unsigned DiagID) { 417 // Perform a conversion to the promoted condition type if needed. 418 if (NewWidth > Val.getBitWidth()) { 419 // If this is an extension, just do it. 420 Val = Val.extend(NewWidth); 421 Val.setIsSigned(NewSign); 422 423 // If the input was signed and negative and the output is 424 // unsigned, don't bother to warn: this is implementation-defined 425 // behavior. 426 // FIXME: Introduce a second, default-ignored warning for this case? 427 } else if (NewWidth < Val.getBitWidth()) { 428 // If this is a truncation, check for overflow. 429 llvm::APSInt ConvVal(Val); 430 ConvVal = ConvVal.trunc(NewWidth); 431 ConvVal.setIsSigned(NewSign); 432 ConvVal = ConvVal.extend(Val.getBitWidth()); 433 ConvVal.setIsSigned(Val.isSigned()); 434 if (ConvVal != Val) 435 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 436 437 // Regardless of whether a diagnostic was emitted, really do the 438 // truncation. 439 Val = Val.trunc(NewWidth); 440 Val.setIsSigned(NewSign); 441 } else if (NewSign != Val.isSigned()) { 442 // Convert the sign to match the sign of the condition. This can cause 443 // overflow as well: unsigned(INTMIN) 444 // We don't diagnose this overflow, because it is implementation-defined 445 // behavior. 446 // FIXME: Introduce a second, default-ignored warning for this case? 447 llvm::APSInt OldVal(Val); 448 Val.setIsSigned(NewSign); 449 } 450} 451 452namespace { 453 struct CaseCompareFunctor { 454 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 455 const llvm::APSInt &RHS) { 456 return LHS.first < RHS; 457 } 458 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 459 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 460 return LHS.first < RHS.first; 461 } 462 bool operator()(const llvm::APSInt &LHS, 463 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 464 return LHS < RHS.first; 465 } 466 }; 467} 468 469/// CmpCaseVals - Comparison predicate for sorting case values. 470/// 471static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 472 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 473 if (lhs.first < rhs.first) 474 return true; 475 476 if (lhs.first == rhs.first && 477 lhs.second->getCaseLoc().getRawEncoding() 478 < rhs.second->getCaseLoc().getRawEncoding()) 479 return true; 480 return false; 481} 482 483/// CmpEnumVals - Comparison predicate for sorting enumeration values. 484/// 485static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 486 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 487{ 488 return lhs.first < rhs.first; 489} 490 491/// EqEnumVals - Comparison preficate for uniqing enumeration values. 492/// 493static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 494 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 495{ 496 return lhs.first == rhs.first; 497} 498 499/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 500/// potentially integral-promoted expression @p expr. 501static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 502 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 503 expr = cleanups->getSubExpr(); 504 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 505 if (impcast->getCastKind() != CK_IntegralCast) break; 506 expr = impcast->getSubExpr(); 507 } 508 return expr->getType(); 509} 510 511StmtResult 512Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 513 Decl *CondVar) { 514 ExprResult CondResult; 515 516 VarDecl *ConditionVar = 0; 517 if (CondVar) { 518 ConditionVar = cast<VarDecl>(CondVar); 519 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 520 if (CondResult.isInvalid()) 521 return StmtError(); 522 523 Cond = CondResult.release(); 524 } 525 526 if (!Cond) 527 return StmtError(); 528 529 class SwitchConvertDiagnoser : public ICEConvertDiagnoser { 530 Expr *Cond; 531 532 public: 533 SwitchConvertDiagnoser(Expr *Cond) 534 : ICEConvertDiagnoser(false, true), Cond(Cond) { } 535 536 virtual DiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 537 QualType T) { 538 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T; 539 } 540 541 virtual DiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 542 QualType T) { 543 return S.Diag(Loc, diag::err_switch_incomplete_class_type) 544 << T << Cond->getSourceRange(); 545 } 546 547 virtual DiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 548 QualType T, 549 QualType ConvTy) { 550 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy; 551 } 552 553 virtual DiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 554 QualType ConvTy) { 555 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 556 << ConvTy->isEnumeralType() << ConvTy; 557 } 558 559 virtual DiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 560 QualType T) { 561 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T; 562 } 563 564 virtual DiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 565 QualType ConvTy) { 566 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 567 << ConvTy->isEnumeralType() << ConvTy; 568 } 569 570 virtual DiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 571 QualType T, 572 QualType ConvTy) { 573 return DiagnosticBuilder::getEmpty(); 574 } 575 } SwitchDiagnoser(Cond); 576 577 CondResult 578 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, SwitchDiagnoser, 579 /*AllowScopedEnumerations*/ true); 580 if (CondResult.isInvalid()) return StmtError(); 581 Cond = CondResult.take(); 582 583 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 584 CondResult = UsualUnaryConversions(Cond); 585 if (CondResult.isInvalid()) return StmtError(); 586 Cond = CondResult.take(); 587 588 if (!CondVar) { 589 CheckImplicitConversions(Cond, SwitchLoc); 590 CondResult = MaybeCreateExprWithCleanups(Cond); 591 if (CondResult.isInvalid()) 592 return StmtError(); 593 Cond = CondResult.take(); 594 } 595 596 getCurFunction()->setHasBranchIntoScope(); 597 598 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 599 getCurFunction()->SwitchStack.push_back(SS); 600 return Owned(SS); 601} 602 603static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 604 if (Val.getBitWidth() < BitWidth) 605 Val = Val.extend(BitWidth); 606 else if (Val.getBitWidth() > BitWidth) 607 Val = Val.trunc(BitWidth); 608 Val.setIsSigned(IsSigned); 609} 610 611StmtResult 612Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 613 Stmt *BodyStmt) { 614 SwitchStmt *SS = cast<SwitchStmt>(Switch); 615 assert(SS == getCurFunction()->SwitchStack.back() && 616 "switch stack missing push/pop!"); 617 618 SS->setBody(BodyStmt, SwitchLoc); 619 getCurFunction()->SwitchStack.pop_back(); 620 621 Expr *CondExpr = SS->getCond(); 622 if (!CondExpr) return StmtError(); 623 624 QualType CondType = CondExpr->getType(); 625 626 Expr *CondExprBeforePromotion = CondExpr; 627 QualType CondTypeBeforePromotion = 628 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 629 630 // C++ 6.4.2.p2: 631 // Integral promotions are performed (on the switch condition). 632 // 633 // A case value unrepresentable by the original switch condition 634 // type (before the promotion) doesn't make sense, even when it can 635 // be represented by the promoted type. Therefore we need to find 636 // the pre-promotion type of the switch condition. 637 if (!CondExpr->isTypeDependent()) { 638 // We have already converted the expression to an integral or enumeration 639 // type, when we started the switch statement. If we don't have an 640 // appropriate type now, just return an error. 641 if (!CondType->isIntegralOrEnumerationType()) 642 return StmtError(); 643 644 if (CondExpr->isKnownToHaveBooleanValue()) { 645 // switch(bool_expr) {...} is often a programmer error, e.g. 646 // switch(n && mask) { ... } // Doh - should be "n & mask". 647 // One can always use an if statement instead of switch(bool_expr). 648 Diag(SwitchLoc, diag::warn_bool_switch_condition) 649 << CondExpr->getSourceRange(); 650 } 651 } 652 653 // Get the bitwidth of the switched-on value before promotions. We must 654 // convert the integer case values to this width before comparison. 655 bool HasDependentValue 656 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 657 unsigned CondWidth 658 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 659 bool CondIsSigned 660 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 661 662 // Accumulate all of the case values in a vector so that we can sort them 663 // and detect duplicates. This vector contains the APInt for the case after 664 // it has been converted to the condition type. 665 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 666 CaseValsTy CaseVals; 667 668 // Keep track of any GNU case ranges we see. The APSInt is the low value. 669 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 670 CaseRangesTy CaseRanges; 671 672 DefaultStmt *TheDefaultStmt = 0; 673 674 bool CaseListIsErroneous = false; 675 676 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 677 SC = SC->getNextSwitchCase()) { 678 679 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 680 if (TheDefaultStmt) { 681 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 682 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 683 684 // FIXME: Remove the default statement from the switch block so that 685 // we'll return a valid AST. This requires recursing down the AST and 686 // finding it, not something we are set up to do right now. For now, 687 // just lop the entire switch stmt out of the AST. 688 CaseListIsErroneous = true; 689 } 690 TheDefaultStmt = DS; 691 692 } else { 693 CaseStmt *CS = cast<CaseStmt>(SC); 694 695 Expr *Lo = CS->getLHS(); 696 697 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 698 HasDependentValue = true; 699 break; 700 } 701 702 llvm::APSInt LoVal; 703 704 if (getLangOpts().CPlusPlus0x) { 705 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 706 // constant expression of the promoted type of the switch condition. 707 ExprResult ConvLo = 708 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); 709 if (ConvLo.isInvalid()) { 710 CaseListIsErroneous = true; 711 continue; 712 } 713 Lo = ConvLo.take(); 714 } else { 715 // We already verified that the expression has a i-c-e value (C99 716 // 6.8.4.2p3) - get that value now. 717 LoVal = Lo->EvaluateKnownConstInt(Context); 718 719 // If the LHS is not the same type as the condition, insert an implicit 720 // cast. 721 Lo = DefaultLvalueConversion(Lo).take(); 722 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 723 } 724 725 // Convert the value to the same width/sign as the condition had prior to 726 // integral promotions. 727 // 728 // FIXME: This causes us to reject valid code: 729 // switch ((char)c) { case 256: case 0: return 0; } 730 // Here we claim there is a duplicated condition value, but there is not. 731 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 732 Lo->getLocStart(), 733 diag::warn_case_value_overflow); 734 735 CS->setLHS(Lo); 736 737 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 738 if (CS->getRHS()) { 739 if (CS->getRHS()->isTypeDependent() || 740 CS->getRHS()->isValueDependent()) { 741 HasDependentValue = true; 742 break; 743 } 744 CaseRanges.push_back(std::make_pair(LoVal, CS)); 745 } else 746 CaseVals.push_back(std::make_pair(LoVal, CS)); 747 } 748 } 749 750 if (!HasDependentValue) { 751 // If we don't have a default statement, check whether the 752 // condition is constant. 753 llvm::APSInt ConstantCondValue; 754 bool HasConstantCond = false; 755 if (!HasDependentValue && !TheDefaultStmt) { 756 HasConstantCond 757 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, 758 Expr::SE_AllowSideEffects); 759 assert(!HasConstantCond || 760 (ConstantCondValue.getBitWidth() == CondWidth && 761 ConstantCondValue.isSigned() == CondIsSigned)); 762 } 763 bool ShouldCheckConstantCond = HasConstantCond; 764 765 // Sort all the scalar case values so we can easily detect duplicates. 766 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 767 768 if (!CaseVals.empty()) { 769 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 770 if (ShouldCheckConstantCond && 771 CaseVals[i].first == ConstantCondValue) 772 ShouldCheckConstantCond = false; 773 774 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 775 // If we have a duplicate, report it. 776 // First, determine if either case value has a name 777 StringRef PrevString, CurrString; 778 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts(); 779 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts(); 780 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) { 781 PrevString = DeclRef->getDecl()->getName(); 782 } 783 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) { 784 CurrString = DeclRef->getDecl()->getName(); 785 } 786 llvm::SmallString<16> CaseValStr; 787 CaseVals[i-1].first.toString(CaseValStr); 788 789 if (PrevString == CurrString) 790 Diag(CaseVals[i].second->getLHS()->getLocStart(), 791 diag::err_duplicate_case) << 792 (PrevString.empty() ? CaseValStr.str() : PrevString); 793 else 794 Diag(CaseVals[i].second->getLHS()->getLocStart(), 795 diag::err_duplicate_case_differing_expr) << 796 (PrevString.empty() ? CaseValStr.str() : PrevString) << 797 (CurrString.empty() ? CaseValStr.str() : CurrString) << 798 CaseValStr; 799 800 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 801 diag::note_duplicate_case_prev); 802 // FIXME: We really want to remove the bogus case stmt from the 803 // substmt, but we have no way to do this right now. 804 CaseListIsErroneous = true; 805 } 806 } 807 } 808 809 // Detect duplicate case ranges, which usually don't exist at all in 810 // the first place. 811 if (!CaseRanges.empty()) { 812 // Sort all the case ranges by their low value so we can easily detect 813 // overlaps between ranges. 814 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 815 816 // Scan the ranges, computing the high values and removing empty ranges. 817 std::vector<llvm::APSInt> HiVals; 818 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 819 llvm::APSInt &LoVal = CaseRanges[i].first; 820 CaseStmt *CR = CaseRanges[i].second; 821 Expr *Hi = CR->getRHS(); 822 llvm::APSInt HiVal; 823 824 if (getLangOpts().CPlusPlus0x) { 825 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 826 // constant expression of the promoted type of the switch condition. 827 ExprResult ConvHi = 828 CheckConvertedConstantExpression(Hi, CondType, HiVal, 829 CCEK_CaseValue); 830 if (ConvHi.isInvalid()) { 831 CaseListIsErroneous = true; 832 continue; 833 } 834 Hi = ConvHi.take(); 835 } else { 836 HiVal = Hi->EvaluateKnownConstInt(Context); 837 838 // If the RHS is not the same type as the condition, insert an 839 // implicit cast. 840 Hi = DefaultLvalueConversion(Hi).take(); 841 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 842 } 843 844 // Convert the value to the same width/sign as the condition. 845 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 846 Hi->getLocStart(), 847 diag::warn_case_value_overflow); 848 849 CR->setRHS(Hi); 850 851 // If the low value is bigger than the high value, the case is empty. 852 if (LoVal > HiVal) { 853 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 854 << SourceRange(CR->getLHS()->getLocStart(), 855 Hi->getLocEnd()); 856 CaseRanges.erase(CaseRanges.begin()+i); 857 --i, --e; 858 continue; 859 } 860 861 if (ShouldCheckConstantCond && 862 LoVal <= ConstantCondValue && 863 ConstantCondValue <= HiVal) 864 ShouldCheckConstantCond = false; 865 866 HiVals.push_back(HiVal); 867 } 868 869 // Rescan the ranges, looking for overlap with singleton values and other 870 // ranges. Since the range list is sorted, we only need to compare case 871 // ranges with their neighbors. 872 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 873 llvm::APSInt &CRLo = CaseRanges[i].first; 874 llvm::APSInt &CRHi = HiVals[i]; 875 CaseStmt *CR = CaseRanges[i].second; 876 877 // Check to see whether the case range overlaps with any 878 // singleton cases. 879 CaseStmt *OverlapStmt = 0; 880 llvm::APSInt OverlapVal(32); 881 882 // Find the smallest value >= the lower bound. If I is in the 883 // case range, then we have overlap. 884 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 885 CaseVals.end(), CRLo, 886 CaseCompareFunctor()); 887 if (I != CaseVals.end() && I->first < CRHi) { 888 OverlapVal = I->first; // Found overlap with scalar. 889 OverlapStmt = I->second; 890 } 891 892 // Find the smallest value bigger than the upper bound. 893 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 894 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 895 OverlapVal = (I-1)->first; // Found overlap with scalar. 896 OverlapStmt = (I-1)->second; 897 } 898 899 // Check to see if this case stmt overlaps with the subsequent 900 // case range. 901 if (i && CRLo <= HiVals[i-1]) { 902 OverlapVal = HiVals[i-1]; // Found overlap with range. 903 OverlapStmt = CaseRanges[i-1].second; 904 } 905 906 if (OverlapStmt) { 907 // If we have a duplicate, report it. 908 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 909 << OverlapVal.toString(10); 910 Diag(OverlapStmt->getLHS()->getLocStart(), 911 diag::note_duplicate_case_prev); 912 // FIXME: We really want to remove the bogus case stmt from the 913 // substmt, but we have no way to do this right now. 914 CaseListIsErroneous = true; 915 } 916 } 917 } 918 919 // Complain if we have a constant condition and we didn't find a match. 920 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 921 // TODO: it would be nice if we printed enums as enums, chars as 922 // chars, etc. 923 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 924 << ConstantCondValue.toString(10) 925 << CondExpr->getSourceRange(); 926 } 927 928 // Check to see if switch is over an Enum and handles all of its 929 // values. We only issue a warning if there is not 'default:', but 930 // we still do the analysis to preserve this information in the AST 931 // (which can be used by flow-based analyes). 932 // 933 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 934 935 // If switch has default case, then ignore it. 936 if (!CaseListIsErroneous && !HasConstantCond && ET) { 937 const EnumDecl *ED = ET->getDecl(); 938 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 939 EnumValsTy; 940 EnumValsTy EnumVals; 941 942 // Gather all enum values, set their type and sort them, 943 // allowing easier comparison with CaseVals. 944 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 945 EDI != ED->enumerator_end(); ++EDI) { 946 llvm::APSInt Val = EDI->getInitVal(); 947 AdjustAPSInt(Val, CondWidth, CondIsSigned); 948 EnumVals.push_back(std::make_pair(Val, *EDI)); 949 } 950 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 951 EnumValsTy::iterator EIend = 952 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 953 954 // See which case values aren't in enum. 955 EnumValsTy::const_iterator EI = EnumVals.begin(); 956 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 957 CI != CaseVals.end(); CI++) { 958 while (EI != EIend && EI->first < CI->first) 959 EI++; 960 if (EI == EIend || EI->first > CI->first) 961 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 962 << CondTypeBeforePromotion; 963 } 964 // See which of case ranges aren't in enum 965 EI = EnumVals.begin(); 966 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 967 RI != CaseRanges.end() && EI != EIend; RI++) { 968 while (EI != EIend && EI->first < RI->first) 969 EI++; 970 971 if (EI == EIend || EI->first != RI->first) { 972 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 973 << CondTypeBeforePromotion; 974 } 975 976 llvm::APSInt Hi = 977 RI->second->getRHS()->EvaluateKnownConstInt(Context); 978 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 979 while (EI != EIend && EI->first < Hi) 980 EI++; 981 if (EI == EIend || EI->first != Hi) 982 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 983 << CondTypeBeforePromotion; 984 } 985 986 // Check which enum vals aren't in switch 987 CaseValsTy::const_iterator CI = CaseVals.begin(); 988 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 989 bool hasCasesNotInSwitch = false; 990 991 SmallVector<DeclarationName,8> UnhandledNames; 992 993 for (EI = EnumVals.begin(); EI != EIend; EI++){ 994 // Drop unneeded case values 995 llvm::APSInt CIVal; 996 while (CI != CaseVals.end() && CI->first < EI->first) 997 CI++; 998 999 if (CI != CaseVals.end() && CI->first == EI->first) 1000 continue; 1001 1002 // Drop unneeded case ranges 1003 for (; RI != CaseRanges.end(); RI++) { 1004 llvm::APSInt Hi = 1005 RI->second->getRHS()->EvaluateKnownConstInt(Context); 1006 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 1007 if (EI->first <= Hi) 1008 break; 1009 } 1010 1011 if (RI == CaseRanges.end() || EI->first < RI->first) { 1012 hasCasesNotInSwitch = true; 1013 UnhandledNames.push_back(EI->second->getDeclName()); 1014 } 1015 } 1016 1017 if (TheDefaultStmt && UnhandledNames.empty()) 1018 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); 1019 1020 // Produce a nice diagnostic if multiple values aren't handled. 1021 switch (UnhandledNames.size()) { 1022 case 0: break; 1023 case 1: 1024 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1025 ? diag::warn_def_missing_case1 : diag::warn_missing_case1) 1026 << UnhandledNames[0]; 1027 break; 1028 case 2: 1029 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1030 ? diag::warn_def_missing_case2 : diag::warn_missing_case2) 1031 << UnhandledNames[0] << UnhandledNames[1]; 1032 break; 1033 case 3: 1034 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1035 ? diag::warn_def_missing_case3 : diag::warn_missing_case3) 1036 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1037 break; 1038 default: 1039 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1040 ? diag::warn_def_missing_cases : diag::warn_missing_cases) 1041 << (unsigned)UnhandledNames.size() 1042 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1043 break; 1044 } 1045 1046 if (!hasCasesNotInSwitch) 1047 SS->setAllEnumCasesCovered(); 1048 } 1049 } 1050 1051 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, 1052 diag::warn_empty_switch_body); 1053 1054 // FIXME: If the case list was broken is some way, we don't have a good system 1055 // to patch it up. Instead, just return the whole substmt as broken. 1056 if (CaseListIsErroneous) 1057 return StmtError(); 1058 1059 return Owned(SS); 1060} 1061 1062void 1063Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, 1064 Expr *SrcExpr) { 1065 unsigned DIAG = diag::warn_not_in_enum_assignement; 1066 if (Diags.getDiagnosticLevel(DIAG, SrcExpr->getExprLoc()) 1067 == DiagnosticsEngine::Ignored) 1068 return; 1069 1070 if (const EnumType *ET = DstType->getAs<EnumType>()) 1071 if (!Context.hasSameType(SrcType, DstType) && 1072 SrcType->isIntegerType()) { 1073 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() && 1074 SrcExpr->isIntegerConstantExpr(Context)) { 1075 // Get the bitwidth of the enum value before promotions. 1076 unsigned DstWith = Context.getIntWidth(DstType); 1077 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType(); 1078 1079 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context); 1080 const EnumDecl *ED = ET->getDecl(); 1081 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 1082 EnumValsTy; 1083 EnumValsTy EnumVals; 1084 1085 // Gather all enum values, set their type and sort them, 1086 // allowing easier comparison with rhs constant. 1087 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 1088 EDI != ED->enumerator_end(); ++EDI) { 1089 llvm::APSInt Val = EDI->getInitVal(); 1090 AdjustAPSInt(Val, DstWith, DstIsSigned); 1091 EnumVals.push_back(std::make_pair(Val, *EDI)); 1092 } 1093 if (EnumVals.empty()) 1094 return; 1095 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 1096 EnumValsTy::iterator EIend = 1097 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 1098 1099 // See which case values aren't in enum. 1100 EnumValsTy::const_iterator EI = EnumVals.begin(); 1101 while (EI != EIend && EI->first < RhsVal) 1102 EI++; 1103 if (EI == EIend || EI->first != RhsVal) { 1104 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignement) 1105 << DstType; 1106 } 1107 } 1108 } 1109} 1110 1111StmtResult 1112Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 1113 Decl *CondVar, Stmt *Body) { 1114 ExprResult CondResult(Cond.release()); 1115 1116 VarDecl *ConditionVar = 0; 1117 if (CondVar) { 1118 ConditionVar = cast<VarDecl>(CondVar); 1119 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 1120 if (CondResult.isInvalid()) 1121 return StmtError(); 1122 } 1123 Expr *ConditionExpr = CondResult.take(); 1124 if (!ConditionExpr) 1125 return StmtError(); 1126 1127 DiagnoseUnusedExprResult(Body); 1128 1129 if (isa<NullStmt>(Body)) 1130 getCurCompoundScope().setHasEmptyLoopBodies(); 1131 1132 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 1133 Body, WhileLoc)); 1134} 1135 1136StmtResult 1137Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 1138 SourceLocation WhileLoc, SourceLocation CondLParen, 1139 Expr *Cond, SourceLocation CondRParen) { 1140 assert(Cond && "ActOnDoStmt(): missing expression"); 1141 1142 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 1143 if (CondResult.isInvalid() || CondResult.isInvalid()) 1144 return StmtError(); 1145 Cond = CondResult.take(); 1146 1147 CheckImplicitConversions(Cond, DoLoc); 1148 CondResult = MaybeCreateExprWithCleanups(Cond); 1149 if (CondResult.isInvalid()) 1150 return StmtError(); 1151 Cond = CondResult.take(); 1152 1153 DiagnoseUnusedExprResult(Body); 1154 1155 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 1156} 1157 1158namespace { 1159 // This visitor will traverse a conditional statement and store all 1160 // the evaluated decls into a vector. Simple is set to true if none 1161 // of the excluded constructs are used. 1162 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { 1163 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1164 llvm::SmallVector<SourceRange, 10> &Ranges; 1165 bool Simple; 1166public: 1167 typedef EvaluatedExprVisitor<DeclExtractor> Inherited; 1168 1169 DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, 1170 llvm::SmallVector<SourceRange, 10> &Ranges) : 1171 Inherited(S.Context), 1172 Decls(Decls), 1173 Ranges(Ranges), 1174 Simple(true) {} 1175 1176 bool isSimple() { return Simple; } 1177 1178 // Replaces the method in EvaluatedExprVisitor. 1179 void VisitMemberExpr(MemberExpr* E) { 1180 Simple = false; 1181 } 1182 1183 // Any Stmt not whitelisted will cause the condition to be marked complex. 1184 void VisitStmt(Stmt *S) { 1185 Simple = false; 1186 } 1187 1188 void VisitBinaryOperator(BinaryOperator *E) { 1189 Visit(E->getLHS()); 1190 Visit(E->getRHS()); 1191 } 1192 1193 void VisitCastExpr(CastExpr *E) { 1194 Visit(E->getSubExpr()); 1195 } 1196 1197 void VisitUnaryOperator(UnaryOperator *E) { 1198 // Skip checking conditionals with derefernces. 1199 if (E->getOpcode() == UO_Deref) 1200 Simple = false; 1201 else 1202 Visit(E->getSubExpr()); 1203 } 1204 1205 void VisitConditionalOperator(ConditionalOperator *E) { 1206 Visit(E->getCond()); 1207 Visit(E->getTrueExpr()); 1208 Visit(E->getFalseExpr()); 1209 } 1210 1211 void VisitParenExpr(ParenExpr *E) { 1212 Visit(E->getSubExpr()); 1213 } 1214 1215 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { 1216 Visit(E->getOpaqueValue()->getSourceExpr()); 1217 Visit(E->getFalseExpr()); 1218 } 1219 1220 void VisitIntegerLiteral(IntegerLiteral *E) { } 1221 void VisitFloatingLiteral(FloatingLiteral *E) { } 1222 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } 1223 void VisitCharacterLiteral(CharacterLiteral *E) { } 1224 void VisitGNUNullExpr(GNUNullExpr *E) { } 1225 void VisitImaginaryLiteral(ImaginaryLiteral *E) { } 1226 1227 void VisitDeclRefExpr(DeclRefExpr *E) { 1228 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); 1229 if (!VD) return; 1230 1231 Ranges.push_back(E->getSourceRange()); 1232 1233 Decls.insert(VD); 1234 } 1235 1236 }; // end class DeclExtractor 1237 1238 // DeclMatcher checks to see if the decls are used in a non-evauluated 1239 // context. 1240 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { 1241 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1242 bool FoundDecl; 1243 1244public: 1245 typedef EvaluatedExprVisitor<DeclMatcher> Inherited; 1246 1247 DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, Stmt *Statement) : 1248 Inherited(S.Context), Decls(Decls), FoundDecl(false) { 1249 if (!Statement) return; 1250 1251 Visit(Statement); 1252 } 1253 1254 void VisitReturnStmt(ReturnStmt *S) { 1255 FoundDecl = true; 1256 } 1257 1258 void VisitBreakStmt(BreakStmt *S) { 1259 FoundDecl = true; 1260 } 1261 1262 void VisitGotoStmt(GotoStmt *S) { 1263 FoundDecl = true; 1264 } 1265 1266 void VisitCastExpr(CastExpr *E) { 1267 if (E->getCastKind() == CK_LValueToRValue) 1268 CheckLValueToRValueCast(E->getSubExpr()); 1269 else 1270 Visit(E->getSubExpr()); 1271 } 1272 1273 void CheckLValueToRValueCast(Expr *E) { 1274 E = E->IgnoreParenImpCasts(); 1275 1276 if (isa<DeclRefExpr>(E)) { 1277 return; 1278 } 1279 1280 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1281 Visit(CO->getCond()); 1282 CheckLValueToRValueCast(CO->getTrueExpr()); 1283 CheckLValueToRValueCast(CO->getFalseExpr()); 1284 return; 1285 } 1286 1287 if (BinaryConditionalOperator *BCO = 1288 dyn_cast<BinaryConditionalOperator>(E)) { 1289 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); 1290 CheckLValueToRValueCast(BCO->getFalseExpr()); 1291 return; 1292 } 1293 1294 Visit(E); 1295 } 1296 1297 void VisitDeclRefExpr(DeclRefExpr *E) { 1298 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) 1299 if (Decls.count(VD)) 1300 FoundDecl = true; 1301 } 1302 1303 bool FoundDeclInUse() { return FoundDecl; } 1304 1305 }; // end class DeclMatcher 1306 1307 void CheckForLoopConditionalStatement(Sema &S, Expr *Second, 1308 Expr *Third, Stmt *Body) { 1309 // Condition is empty 1310 if (!Second) return; 1311 1312 if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body, 1313 Second->getLocStart()) 1314 == DiagnosticsEngine::Ignored) 1315 return; 1316 1317 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); 1318 llvm::SmallPtrSet<VarDecl*, 8> Decls; 1319 llvm::SmallVector<SourceRange, 10> Ranges; 1320 DeclExtractor DE(S, Decls, Ranges); 1321 DE.Visit(Second); 1322 1323 // Don't analyze complex conditionals. 1324 if (!DE.isSimple()) return; 1325 1326 // No decls found. 1327 if (Decls.size() == 0) return; 1328 1329 // Don't warn on volatile, static, or global variables. 1330 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1331 E = Decls.end(); 1332 I != E; ++I) 1333 if ((*I)->getType().isVolatileQualified() || 1334 (*I)->hasGlobalStorage()) return; 1335 1336 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || 1337 DeclMatcher(S, Decls, Third).FoundDeclInUse() || 1338 DeclMatcher(S, Decls, Body).FoundDeclInUse()) 1339 return; 1340 1341 // Load decl names into diagnostic. 1342 if (Decls.size() > 4) 1343 PDiag << 0; 1344 else { 1345 PDiag << Decls.size(); 1346 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1347 E = Decls.end(); 1348 I != E; ++I) 1349 PDiag << (*I)->getDeclName(); 1350 } 1351 1352 // Load SourceRanges into diagnostic if there is room. 1353 // Otherwise, load the SourceRange of the conditional expression. 1354 if (Ranges.size() <= PartialDiagnostic::MaxArguments) 1355 for (llvm::SmallVector<SourceRange, 10>::iterator I = Ranges.begin(), 1356 E = Ranges.end(); 1357 I != E; ++I) 1358 PDiag << *I; 1359 else 1360 PDiag << Second->getSourceRange(); 1361 1362 S.Diag(Ranges.begin()->getBegin(), PDiag); 1363 } 1364 1365} // end namespace 1366 1367StmtResult 1368Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1369 Stmt *First, FullExprArg second, Decl *secondVar, 1370 FullExprArg third, 1371 SourceLocation RParenLoc, Stmt *Body) { 1372 if (!getLangOpts().CPlusPlus) { 1373 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 1374 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1375 // declare identifiers for objects having storage class 'auto' or 1376 // 'register'. 1377 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 1378 DI!=DE; ++DI) { 1379 VarDecl *VD = dyn_cast<VarDecl>(*DI); 1380 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 1381 VD = 0; 1382 if (VD == 0) 1383 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 1384 // FIXME: mark decl erroneous! 1385 } 1386 } 1387 } 1388 1389 CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body); 1390 1391 ExprResult SecondResult(second.release()); 1392 VarDecl *ConditionVar = 0; 1393 if (secondVar) { 1394 ConditionVar = cast<VarDecl>(secondVar); 1395 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 1396 if (SecondResult.isInvalid()) 1397 return StmtError(); 1398 } 1399 1400 Expr *Third = third.release().takeAs<Expr>(); 1401 1402 DiagnoseUnusedExprResult(First); 1403 DiagnoseUnusedExprResult(Third); 1404 DiagnoseUnusedExprResult(Body); 1405 1406 if (isa<NullStmt>(Body)) 1407 getCurCompoundScope().setHasEmptyLoopBodies(); 1408 1409 return Owned(new (Context) ForStmt(Context, First, 1410 SecondResult.take(), ConditionVar, 1411 Third, Body, ForLoc, LParenLoc, 1412 RParenLoc)); 1413} 1414 1415/// In an Objective C collection iteration statement: 1416/// for (x in y) 1417/// x can be an arbitrary l-value expression. Bind it up as a 1418/// full-expression. 1419StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1420 // Reduce placeholder expressions here. Note that this rejects the 1421 // use of pseudo-object l-values in this position. 1422 ExprResult result = CheckPlaceholderExpr(E); 1423 if (result.isInvalid()) return StmtError(); 1424 E = result.take(); 1425 1426 CheckImplicitConversions(E); 1427 1428 result = MaybeCreateExprWithCleanups(E); 1429 if (result.isInvalid()) return StmtError(); 1430 1431 return Owned(static_cast<Stmt*>(result.take())); 1432} 1433 1434ExprResult 1435Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1436 if (!collection) 1437 return ExprError(); 1438 1439 // Bail out early if we've got a type-dependent expression. 1440 if (collection->isTypeDependent()) return Owned(collection); 1441 1442 // Perform normal l-value conversion. 1443 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1444 if (result.isInvalid()) 1445 return ExprError(); 1446 collection = result.take(); 1447 1448 // The operand needs to have object-pointer type. 1449 // TODO: should we do a contextual conversion? 1450 const ObjCObjectPointerType *pointerType = 1451 collection->getType()->getAs<ObjCObjectPointerType>(); 1452 if (!pointerType) 1453 return Diag(forLoc, diag::err_collection_expr_type) 1454 << collection->getType() << collection->getSourceRange(); 1455 1456 // Check that the operand provides 1457 // - countByEnumeratingWithState:objects:count: 1458 const ObjCObjectType *objectType = pointerType->getObjectType(); 1459 ObjCInterfaceDecl *iface = objectType->getInterface(); 1460 1461 // If we have a forward-declared type, we can't do this check. 1462 // Under ARC, it is an error not to have a forward-declared class. 1463 if (iface && 1464 RequireCompleteType(forLoc, QualType(objectType, 0), 1465 getLangOpts().ObjCAutoRefCount 1466 ? diag::err_arc_collection_forward 1467 : 0, 1468 collection)) { 1469 // Otherwise, if we have any useful type information, check that 1470 // the type declares the appropriate method. 1471 } else if (iface || !objectType->qual_empty()) { 1472 IdentifierInfo *selectorIdents[] = { 1473 &Context.Idents.get("countByEnumeratingWithState"), 1474 &Context.Idents.get("objects"), 1475 &Context.Idents.get("count") 1476 }; 1477 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1478 1479 ObjCMethodDecl *method = 0; 1480 1481 // If there's an interface, look in both the public and private APIs. 1482 if (iface) { 1483 method = iface->lookupInstanceMethod(selector); 1484 if (!method) method = iface->lookupPrivateMethod(selector); 1485 } 1486 1487 // Also check protocol qualifiers. 1488 if (!method) 1489 method = LookupMethodInQualifiedType(selector, pointerType, 1490 /*instance*/ true); 1491 1492 // If we didn't find it anywhere, give up. 1493 if (!method) { 1494 Diag(forLoc, diag::warn_collection_expr_type) 1495 << collection->getType() << selector << collection->getSourceRange(); 1496 } 1497 1498 // TODO: check for an incompatible signature? 1499 } 1500 1501 // Wrap up any cleanups in the expression. 1502 return Owned(MaybeCreateExprWithCleanups(collection)); 1503} 1504 1505StmtResult 1506Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1507 SourceLocation LParenLoc, 1508 Stmt *First, Expr *collection, 1509 SourceLocation RParenLoc) { 1510 1511 ExprResult CollectionExprResult = 1512 CheckObjCForCollectionOperand(ForLoc, collection); 1513 1514 if (First) { 1515 QualType FirstType; 1516 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1517 if (!DS->isSingleDecl()) 1518 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1519 diag::err_toomany_element_decls)); 1520 1521 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1522 FirstType = D->getType(); 1523 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1524 // declare identifiers for objects having storage class 'auto' or 1525 // 'register'. 1526 if (!D->hasLocalStorage()) 1527 return StmtError(Diag(D->getLocation(), 1528 diag::err_non_variable_decl_in_for)); 1529 } else { 1530 Expr *FirstE = cast<Expr>(First); 1531 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1532 return StmtError(Diag(First->getLocStart(), 1533 diag::err_selector_element_not_lvalue) 1534 << First->getSourceRange()); 1535 1536 FirstType = static_cast<Expr*>(First)->getType(); 1537 } 1538 if (!FirstType->isDependentType() && 1539 !FirstType->isObjCObjectPointerType() && 1540 !FirstType->isBlockPointerType()) 1541 return StmtError(Diag(ForLoc, diag::err_selector_element_type) 1542 << FirstType << First->getSourceRange()); 1543 } 1544 1545 if (CollectionExprResult.isInvalid()) 1546 return StmtError(); 1547 1548 return Owned(new (Context) ObjCForCollectionStmt(First, 1549 CollectionExprResult.take(), 0, 1550 ForLoc, RParenLoc)); 1551} 1552 1553namespace { 1554 1555enum BeginEndFunction { 1556 BEF_begin, 1557 BEF_end 1558}; 1559 1560/// Build a variable declaration for a for-range statement. 1561static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1562 QualType Type, const char *Name) { 1563 DeclContext *DC = SemaRef.CurContext; 1564 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1565 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1566 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1567 TInfo, SC_Auto, SC_None); 1568 Decl->setImplicit(); 1569 return Decl; 1570} 1571 1572/// Finish building a variable declaration for a for-range statement. 1573/// \return true if an error occurs. 1574static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1575 SourceLocation Loc, int diag) { 1576 // Deduce the type for the iterator variable now rather than leaving it to 1577 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1578 TypeSourceInfo *InitTSI = 0; 1579 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || 1580 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) == 1581 Sema::DAR_Failed) 1582 SemaRef.Diag(Loc, diag) << Init->getType(); 1583 if (!InitTSI) { 1584 Decl->setInvalidDecl(); 1585 return true; 1586 } 1587 Decl->setTypeSourceInfo(InitTSI); 1588 Decl->setType(InitTSI->getType()); 1589 1590 // In ARC, infer lifetime. 1591 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1592 // we're doing the equivalent of fast iteration. 1593 if (SemaRef.getLangOpts().ObjCAutoRefCount && 1594 SemaRef.inferObjCARCLifetime(Decl)) 1595 Decl->setInvalidDecl(); 1596 1597 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1598 /*TypeMayContainAuto=*/false); 1599 SemaRef.FinalizeDeclaration(Decl); 1600 SemaRef.CurContext->addHiddenDecl(Decl); 1601 return false; 1602} 1603 1604/// Produce a note indicating which begin/end function was implicitly called 1605/// by a C++0x for-range statement. This is often not obvious from the code, 1606/// nor from the diagnostics produced when analysing the implicit expressions 1607/// required in a for-range statement. 1608void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1609 BeginEndFunction BEF) { 1610 CallExpr *CE = dyn_cast<CallExpr>(E); 1611 if (!CE) 1612 return; 1613 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1614 if (!D) 1615 return; 1616 SourceLocation Loc = D->getLocation(); 1617 1618 std::string Description; 1619 bool IsTemplate = false; 1620 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1621 Description = SemaRef.getTemplateArgumentBindingsText( 1622 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1623 IsTemplate = true; 1624 } 1625 1626 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1627 << BEF << IsTemplate << Description << E->getType(); 1628} 1629 1630/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1631/// given LookupResult is non-empty, it is assumed to describe a member which 1632/// will be invoked. Otherwise, the function will be found via argument 1633/// dependent lookup. 1634static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1635 SourceLocation Loc, 1636 VarDecl *Decl, 1637 BeginEndFunction BEF, 1638 const DeclarationNameInfo &NameInfo, 1639 LookupResult &MemberLookup, 1640 Expr *Range) { 1641 ExprResult CallExpr; 1642 if (!MemberLookup.empty()) { 1643 ExprResult MemberRef = 1644 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1645 /*IsPtr=*/false, CXXScopeSpec(), 1646 /*TemplateKWLoc=*/SourceLocation(), 1647 /*FirstQualifierInScope=*/0, 1648 MemberLookup, 1649 /*TemplateArgs=*/0); 1650 if (MemberRef.isInvalid()) 1651 return ExprError(); 1652 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1653 Loc, 0); 1654 if (CallExpr.isInvalid()) 1655 return ExprError(); 1656 } else { 1657 UnresolvedSet<0> FoundNames; 1658 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1659 // std is an associated namespace. 1660 UnresolvedLookupExpr *Fn = 1661 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1662 NestedNameSpecifierLoc(), NameInfo, 1663 /*NeedsADL=*/true, /*Overloaded=*/false, 1664 FoundNames.begin(), FoundNames.end(), 1665 /*LookInStdNamespace=*/true); 1666 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1667 0, /*AllowTypoCorrection=*/false); 1668 if (CallExpr.isInvalid()) { 1669 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1670 << Range->getType(); 1671 return ExprError(); 1672 } 1673 } 1674 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1675 diag::err_for_range_iter_deduction_failure)) { 1676 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1677 return ExprError(); 1678 } 1679 return CallExpr; 1680} 1681 1682} 1683 1684static bool ObjCEnumerationCollection(Expr *Collection) { 1685 return !Collection->isTypeDependent() 1686 && Collection->getType()->getAs<ObjCObjectPointerType>() != 0; 1687} 1688 1689/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1690/// 1691/// C++0x [stmt.ranged]: 1692/// A range-based for statement is equivalent to 1693/// 1694/// { 1695/// auto && __range = range-init; 1696/// for ( auto __begin = begin-expr, 1697/// __end = end-expr; 1698/// __begin != __end; 1699/// ++__begin ) { 1700/// for-range-declaration = *__begin; 1701/// statement 1702/// } 1703/// } 1704/// 1705/// The body of the loop is not available yet, since it cannot be analysed until 1706/// we have determined the type of the for-range-declaration. 1707StmtResult 1708Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1709 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1710 SourceLocation RParenLoc) { 1711 if (!First || !Range) 1712 return StmtError(); 1713 1714 if (ObjCEnumerationCollection(Range)) 1715 return ActOnObjCForCollectionStmt(ForLoc, LParenLoc, First, Range, 1716 RParenLoc); 1717 1718 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1719 assert(DS && "first part of for range not a decl stmt"); 1720 1721 if (!DS->isSingleDecl()) { 1722 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1723 return StmtError(); 1724 } 1725 if (DS->getSingleDecl()->isInvalidDecl()) 1726 return StmtError(); 1727 1728 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1729 return StmtError(); 1730 1731 // Build auto && __range = range-init 1732 SourceLocation RangeLoc = Range->getLocStart(); 1733 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1734 Context.getAutoRRefDeductType(), 1735 "__range"); 1736 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1737 diag::err_for_range_deduction_failure)) 1738 return StmtError(); 1739 1740 // Claim the type doesn't contain auto: we've already done the checking. 1741 DeclGroupPtrTy RangeGroup = 1742 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1743 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1744 if (RangeDecl.isInvalid()) 1745 return StmtError(); 1746 1747 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1748 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1749 RParenLoc); 1750} 1751 1752/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1753StmtResult 1754Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1755 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1756 Expr *Inc, Stmt *LoopVarDecl, 1757 SourceLocation RParenLoc) { 1758 Scope *S = getCurScope(); 1759 1760 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1761 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1762 QualType RangeVarType = RangeVar->getType(); 1763 1764 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1765 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1766 1767 StmtResult BeginEndDecl = BeginEnd; 1768 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1769 1770 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1771 SourceLocation RangeLoc = RangeVar->getLocation(); 1772 1773 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); 1774 1775 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1776 VK_LValue, ColonLoc); 1777 if (BeginRangeRef.isInvalid()) 1778 return StmtError(); 1779 1780 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1781 VK_LValue, ColonLoc); 1782 if (EndRangeRef.isInvalid()) 1783 return StmtError(); 1784 1785 QualType AutoType = Context.getAutoDeductType(); 1786 Expr *Range = RangeVar->getInit(); 1787 if (!Range) 1788 return StmtError(); 1789 QualType RangeType = Range->getType(); 1790 1791 if (RequireCompleteType(RangeLoc, RangeType, 1792 diag::err_for_range_incomplete_type)) 1793 return StmtError(); 1794 1795 // Build auto __begin = begin-expr, __end = end-expr. 1796 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1797 "__begin"); 1798 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1799 "__end"); 1800 1801 // Build begin-expr and end-expr and attach to __begin and __end variables. 1802 ExprResult BeginExpr, EndExpr; 1803 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1804 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1805 // __range + __bound, respectively, where __bound is the array bound. If 1806 // _RangeT is an array of unknown size or an array of incomplete type, 1807 // the program is ill-formed; 1808 1809 // begin-expr is __range. 1810 BeginExpr = BeginRangeRef; 1811 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, 1812 diag::err_for_range_iter_deduction_failure)) { 1813 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1814 return StmtError(); 1815 } 1816 1817 // Find the array bound. 1818 ExprResult BoundExpr; 1819 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1820 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1821 Context.getPointerDiffType(), 1822 RangeLoc)); 1823 else if (const VariableArrayType *VAT = 1824 dyn_cast<VariableArrayType>(UnqAT)) 1825 BoundExpr = VAT->getSizeExpr(); 1826 else { 1827 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1828 // UnqAT is not incomplete and Range is not type-dependent. 1829 llvm_unreachable("Unexpected array type in for-range"); 1830 } 1831 1832 // end-expr is __range + __bound. 1833 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), 1834 BoundExpr.get()); 1835 if (EndExpr.isInvalid()) 1836 return StmtError(); 1837 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1838 diag::err_for_range_iter_deduction_failure)) { 1839 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1840 return StmtError(); 1841 } 1842 } else { 1843 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1844 ColonLoc); 1845 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1846 ColonLoc); 1847 1848 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1849 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1850 1851 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1852 // - if _RangeT is a class type, the unqualified-ids begin and end are 1853 // looked up in the scope of class _RangeT as if by class member access 1854 // lookup (3.4.5), and if either (or both) finds at least one 1855 // declaration, begin-expr and end-expr are __range.begin() and 1856 // __range.end(), respectively; 1857 LookupQualifiedName(BeginMemberLookup, D); 1858 LookupQualifiedName(EndMemberLookup, D); 1859 1860 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1861 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1862 << RangeType << BeginMemberLookup.empty(); 1863 return StmtError(); 1864 } 1865 } else { 1866 // - otherwise, begin-expr and end-expr are begin(__range) and 1867 // end(__range), respectively, where begin and end are looked up with 1868 // argument-dependent lookup (3.4.2). For the purposes of this name 1869 // lookup, namespace std is an associated namespace. 1870 } 1871 1872 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1873 BEF_begin, BeginNameInfo, 1874 BeginMemberLookup, 1875 BeginRangeRef.get()); 1876 if (BeginExpr.isInvalid()) 1877 return StmtError(); 1878 1879 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1880 BEF_end, EndNameInfo, 1881 EndMemberLookup, EndRangeRef.get()); 1882 if (EndExpr.isInvalid()) 1883 return StmtError(); 1884 } 1885 1886 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1887 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1888 if (!Context.hasSameType(BeginType, EndType)) { 1889 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1890 << BeginType << EndType; 1891 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1892 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1893 } 1894 1895 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1896 // Claim the type doesn't contain auto: we've already done the checking. 1897 DeclGroupPtrTy BeginEndGroup = 1898 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1899 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1900 1901 const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); 1902 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1903 VK_LValue, ColonLoc); 1904 if (BeginRef.isInvalid()) 1905 return StmtError(); 1906 1907 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1908 VK_LValue, ColonLoc); 1909 if (EndRef.isInvalid()) 1910 return StmtError(); 1911 1912 // Build and check __begin != __end expression. 1913 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1914 BeginRef.get(), EndRef.get()); 1915 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1916 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1917 if (NotEqExpr.isInvalid()) { 1918 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1919 if (!Context.hasSameType(BeginType, EndType)) 1920 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1921 return StmtError(); 1922 } 1923 1924 // Build and check ++__begin expression. 1925 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1926 VK_LValue, ColonLoc); 1927 if (BeginRef.isInvalid()) 1928 return StmtError(); 1929 1930 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1931 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1932 if (IncrExpr.isInvalid()) { 1933 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1934 return StmtError(); 1935 } 1936 1937 // Build and check *__begin expression. 1938 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1939 VK_LValue, ColonLoc); 1940 if (BeginRef.isInvalid()) 1941 return StmtError(); 1942 1943 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1944 if (DerefExpr.isInvalid()) { 1945 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1946 return StmtError(); 1947 } 1948 1949 // Attach *__begin as initializer for VD. 1950 if (!LoopVar->isInvalidDecl()) { 1951 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1952 /*TypeMayContainAuto=*/true); 1953 if (LoopVar->isInvalidDecl()) 1954 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1955 } 1956 } else { 1957 // The range is implicitly used as a placeholder when it is dependent. 1958 RangeVar->setUsed(); 1959 } 1960 1961 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1962 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1963 NotEqExpr.take(), IncrExpr.take(), 1964 LoopVarDS, /*Body=*/0, ForLoc, 1965 ColonLoc, RParenLoc)); 1966} 1967 1968/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach 1969/// statement. 1970StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) { 1971 if (!S || !B) 1972 return StmtError(); 1973 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S); 1974 1975 ForStmt->setBody(B); 1976 return S; 1977} 1978 1979/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1980/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1981/// body cannot be performed until after the type of the range variable is 1982/// determined. 1983StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1984 if (!S || !B) 1985 return StmtError(); 1986 1987 if (isa<ObjCForCollectionStmt>(S)) 1988 return FinishObjCForCollectionStmt(S, B); 1989 1990 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); 1991 ForStmt->setBody(B); 1992 1993 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, 1994 diag::warn_empty_range_based_for_body); 1995 1996 return S; 1997} 1998 1999StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 2000 SourceLocation LabelLoc, 2001 LabelDecl *TheDecl) { 2002 getCurFunction()->setHasBranchIntoScope(); 2003 TheDecl->setUsed(); 2004 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 2005} 2006 2007StmtResult 2008Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 2009 Expr *E) { 2010 // Convert operand to void* 2011 if (!E->isTypeDependent()) { 2012 QualType ETy = E->getType(); 2013 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 2014 ExprResult ExprRes = Owned(E); 2015 AssignConvertType ConvTy = 2016 CheckSingleAssignmentConstraints(DestTy, ExprRes); 2017 if (ExprRes.isInvalid()) 2018 return StmtError(); 2019 E = ExprRes.take(); 2020 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 2021 return StmtError(); 2022 E = MaybeCreateExprWithCleanups(E); 2023 } 2024 2025 getCurFunction()->setHasIndirectGoto(); 2026 2027 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 2028} 2029 2030StmtResult 2031Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 2032 Scope *S = CurScope->getContinueParent(); 2033 if (!S) { 2034 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 2035 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 2036 } 2037 2038 return Owned(new (Context) ContinueStmt(ContinueLoc)); 2039} 2040 2041StmtResult 2042Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 2043 Scope *S = CurScope->getBreakParent(); 2044 if (!S) { 2045 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 2046 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 2047 } 2048 2049 return Owned(new (Context) BreakStmt(BreakLoc)); 2050} 2051 2052/// \brief Determine whether the given expression is a candidate for 2053/// copy elision in either a return statement or a throw expression. 2054/// 2055/// \param ReturnType If we're determining the copy elision candidate for 2056/// a return statement, this is the return type of the function. If we're 2057/// determining the copy elision candidate for a throw expression, this will 2058/// be a NULL type. 2059/// 2060/// \param E The expression being returned from the function or block, or 2061/// being thrown. 2062/// 2063/// \param AllowFunctionParameter Whether we allow function parameters to 2064/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 2065/// we re-use this logic to determine whether we should try to move as part of 2066/// a return or throw (which does allow function parameters). 2067/// 2068/// \returns The NRVO candidate variable, if the return statement may use the 2069/// NRVO, or NULL if there is no such candidate. 2070const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 2071 Expr *E, 2072 bool AllowFunctionParameter) { 2073 QualType ExprType = E->getType(); 2074 // - in a return statement in a function with ... 2075 // ... a class return type ... 2076 if (!ReturnType.isNull()) { 2077 if (!ReturnType->isRecordType()) 2078 return 0; 2079 // ... the same cv-unqualified type as the function return type ... 2080 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 2081 return 0; 2082 } 2083 2084 // ... the expression is the name of a non-volatile automatic object 2085 // (other than a function or catch-clause parameter)) ... 2086 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 2087 if (!DR || DR->refersToEnclosingLocal()) 2088 return 0; 2089 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 2090 if (!VD) 2091 return 0; 2092 2093 // ...object (other than a function or catch-clause parameter)... 2094 if (VD->getKind() != Decl::Var && 2095 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) 2096 return 0; 2097 if (VD->isExceptionVariable()) return 0; 2098 2099 // ...automatic... 2100 if (!VD->hasLocalStorage()) return 0; 2101 2102 // ...non-volatile... 2103 if (VD->getType().isVolatileQualified()) return 0; 2104 if (VD->getType()->isReferenceType()) return 0; 2105 2106 // __block variables can't be allocated in a way that permits NRVO. 2107 if (VD->hasAttr<BlocksAttr>()) return 0; 2108 2109 // Variables with higher required alignment than their type's ABI 2110 // alignment cannot use NRVO. 2111 if (VD->hasAttr<AlignedAttr>() && 2112 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) 2113 return 0; 2114 2115 return VD; 2116} 2117 2118/// \brief Perform the initialization of a potentially-movable value, which 2119/// is the result of return value. 2120/// 2121/// This routine implements C++0x [class.copy]p33, which attempts to treat 2122/// returned lvalues as rvalues in certain cases (to prefer move construction), 2123/// then falls back to treating them as lvalues if that failed. 2124ExprResult 2125Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 2126 const VarDecl *NRVOCandidate, 2127 QualType ResultType, 2128 Expr *Value, 2129 bool AllowNRVO) { 2130 // C++0x [class.copy]p33: 2131 // When the criteria for elision of a copy operation are met or would 2132 // be met save for the fact that the source object is a function 2133 // parameter, and the object to be copied is designated by an lvalue, 2134 // overload resolution to select the constructor for the copy is first 2135 // performed as if the object were designated by an rvalue. 2136 ExprResult Res = ExprError(); 2137 if (AllowNRVO && 2138 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 2139 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 2140 Value->getType(), CK_NoOp, Value, VK_XValue); 2141 2142 Expr *InitExpr = &AsRvalue; 2143 InitializationKind Kind 2144 = InitializationKind::CreateCopy(Value->getLocStart(), 2145 Value->getLocStart()); 2146 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 2147 2148 // [...] If overload resolution fails, or if the type of the first 2149 // parameter of the selected constructor is not an rvalue reference 2150 // to the object's type (possibly cv-qualified), overload resolution 2151 // is performed again, considering the object as an lvalue. 2152 if (Seq) { 2153 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 2154 StepEnd = Seq.step_end(); 2155 Step != StepEnd; ++Step) { 2156 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 2157 continue; 2158 2159 CXXConstructorDecl *Constructor 2160 = cast<CXXConstructorDecl>(Step->Function.Function); 2161 2162 const RValueReferenceType *RRefType 2163 = Constructor->getParamDecl(0)->getType() 2164 ->getAs<RValueReferenceType>(); 2165 2166 // If we don't meet the criteria, break out now. 2167 if (!RRefType || 2168 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 2169 Context.getTypeDeclType(Constructor->getParent()))) 2170 break; 2171 2172 // Promote "AsRvalue" to the heap, since we now need this 2173 // expression node to persist. 2174 Value = ImplicitCastExpr::Create(Context, Value->getType(), 2175 CK_NoOp, Value, 0, VK_XValue); 2176 2177 // Complete type-checking the initialization of the return type 2178 // using the constructor we found. 2179 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 2180 } 2181 } 2182 } 2183 2184 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 2185 // above, or overload resolution failed. Either way, we need to try 2186 // (again) now with the return value expression as written. 2187 if (Res.isInvalid()) 2188 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 2189 2190 return Res; 2191} 2192 2193/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements 2194/// for capturing scopes. 2195/// 2196StmtResult 2197Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2198 // If this is the first return we've seen, infer the return type. 2199 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those 2200 // rules which allows multiple return statements. 2201 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); 2202 QualType FnRetType = CurCap->ReturnType; 2203 2204 // For blocks/lambdas with implicit return types, we check each return 2205 // statement individually, and deduce the common return type when the block 2206 // or lambda is completed. 2207 if (CurCap->HasImplicitReturnType) { 2208 if (RetValExp && !isa<InitListExpr>(RetValExp)) { 2209 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 2210 if (Result.isInvalid()) 2211 return StmtError(); 2212 RetValExp = Result.take(); 2213 2214 if (!RetValExp->isTypeDependent()) 2215 FnRetType = RetValExp->getType(); 2216 else 2217 FnRetType = CurCap->ReturnType = Context.DependentTy; 2218 } else { 2219 if (RetValExp) { 2220 // C++11 [expr.lambda.prim]p4 bans inferring the result from an 2221 // initializer list, because it is not an expression (even 2222 // though we represent it as one). We still deduce 'void'. 2223 Diag(ReturnLoc, diag::err_lambda_return_init_list) 2224 << RetValExp->getSourceRange(); 2225 } 2226 2227 FnRetType = Context.VoidTy; 2228 } 2229 2230 // Although we'll properly infer the type of the block once it's completed, 2231 // make sure we provide a return type now for better error recovery. 2232 if (CurCap->ReturnType.isNull()) 2233 CurCap->ReturnType = FnRetType; 2234 } 2235 assert(!FnRetType.isNull()); 2236 2237 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { 2238 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 2239 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); 2240 return StmtError(); 2241 } 2242 } else { 2243 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap); 2244 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){ 2245 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); 2246 return StmtError(); 2247 } 2248 } 2249 2250 // Otherwise, verify that this result type matches the previous one. We are 2251 // pickier with blocks than for normal functions because we don't have GCC 2252 // compatibility to worry about here. 2253 const VarDecl *NRVOCandidate = 0; 2254 if (FnRetType->isDependentType()) { 2255 // Delay processing for now. TODO: there are lots of dependent 2256 // types we can conclusively prove aren't void. 2257 } else if (FnRetType->isVoidType()) { 2258 if (RetValExp && !isa<InitListExpr>(RetValExp) && 2259 !(getLangOpts().CPlusPlus && 2260 (RetValExp->isTypeDependent() || 2261 RetValExp->getType()->isVoidType()))) { 2262 if (!getLangOpts().CPlusPlus && 2263 RetValExp->getType()->isVoidType()) 2264 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; 2265 else { 2266 Diag(ReturnLoc, diag::err_return_block_has_expr); 2267 RetValExp = 0; 2268 } 2269 } 2270 } else if (!RetValExp) { 2271 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 2272 } else if (!RetValExp->isTypeDependent()) { 2273 // we have a non-void block with an expression, continue checking 2274 2275 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2276 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2277 // function return. 2278 2279 // In C++ the return statement is handled via a copy initialization. 2280 // the C version of which boils down to CheckSingleAssignmentConstraints. 2281 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2282 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2283 FnRetType, 2284 NRVOCandidate != 0); 2285 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2286 FnRetType, RetValExp); 2287 if (Res.isInvalid()) { 2288 // FIXME: Cleanup temporaries here, anyway? 2289 return StmtError(); 2290 } 2291 RetValExp = Res.take(); 2292 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2293 } 2294 2295 if (RetValExp) { 2296 CheckImplicitConversions(RetValExp, ReturnLoc); 2297 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2298 } 2299 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 2300 NRVOCandidate); 2301 2302 // If we need to check for the named return value optimization, 2303 // or if we need to infer the return type, 2304 // save the return statement in our scope for later processing. 2305 if (CurCap->HasImplicitReturnType || 2306 (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2307 !CurContext->isDependentContext())) 2308 FunctionScopes.back()->Returns.push_back(Result); 2309 2310 return Owned(Result); 2311} 2312 2313StmtResult 2314Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2315 // Check for unexpanded parameter packs. 2316 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 2317 return StmtError(); 2318 2319 if (isa<CapturingScopeInfo>(getCurFunction())) 2320 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); 2321 2322 QualType FnRetType; 2323 QualType RelatedRetType; 2324 if (const FunctionDecl *FD = getCurFunctionDecl()) { 2325 FnRetType = FD->getResultType(); 2326 if (FD->hasAttr<NoReturnAttr>() || 2327 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 2328 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 2329 << FD->getDeclName(); 2330 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2331 FnRetType = MD->getResultType(); 2332 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 2333 // In the implementation of a method with a related return type, the 2334 // type used to type-check the validity of return statements within the 2335 // method body is a pointer to the type of the class being implemented. 2336 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 2337 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); 2338 } 2339 } else // If we don't have a function/method context, bail. 2340 return StmtError(); 2341 2342 ReturnStmt *Result = 0; 2343 if (FnRetType->isVoidType()) { 2344 if (RetValExp) { 2345 if (isa<InitListExpr>(RetValExp)) { 2346 // We simply never allow init lists as the return value of void 2347 // functions. This is compatible because this was never allowed before, 2348 // so there's no legacy code to deal with. 2349 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2350 int FunctionKind = 0; 2351 if (isa<ObjCMethodDecl>(CurDecl)) 2352 FunctionKind = 1; 2353 else if (isa<CXXConstructorDecl>(CurDecl)) 2354 FunctionKind = 2; 2355 else if (isa<CXXDestructorDecl>(CurDecl)) 2356 FunctionKind = 3; 2357 2358 Diag(ReturnLoc, diag::err_return_init_list) 2359 << CurDecl->getDeclName() << FunctionKind 2360 << RetValExp->getSourceRange(); 2361 2362 // Drop the expression. 2363 RetValExp = 0; 2364 } else if (!RetValExp->isTypeDependent()) { 2365 // C99 6.8.6.4p1 (ext_ since GCC warns) 2366 unsigned D = diag::ext_return_has_expr; 2367 if (RetValExp->getType()->isVoidType()) 2368 D = diag::ext_return_has_void_expr; 2369 else { 2370 ExprResult Result = Owned(RetValExp); 2371 Result = IgnoredValueConversions(Result.take()); 2372 if (Result.isInvalid()) 2373 return StmtError(); 2374 RetValExp = Result.take(); 2375 RetValExp = ImpCastExprToType(RetValExp, 2376 Context.VoidTy, CK_ToVoid).take(); 2377 } 2378 2379 // return (some void expression); is legal in C++. 2380 if (D != diag::ext_return_has_void_expr || 2381 !getLangOpts().CPlusPlus) { 2382 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2383 2384 int FunctionKind = 0; 2385 if (isa<ObjCMethodDecl>(CurDecl)) 2386 FunctionKind = 1; 2387 else if (isa<CXXConstructorDecl>(CurDecl)) 2388 FunctionKind = 2; 2389 else if (isa<CXXDestructorDecl>(CurDecl)) 2390 FunctionKind = 3; 2391 2392 Diag(ReturnLoc, D) 2393 << CurDecl->getDeclName() << FunctionKind 2394 << RetValExp->getSourceRange(); 2395 } 2396 } 2397 2398 if (RetValExp) { 2399 CheckImplicitConversions(RetValExp, ReturnLoc); 2400 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2401 } 2402 } 2403 2404 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 2405 } else if (!RetValExp && !FnRetType->isDependentType()) { 2406 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 2407 // C99 6.8.6.4p1 (ext_ since GCC warns) 2408 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; 2409 2410 if (FunctionDecl *FD = getCurFunctionDecl()) 2411 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 2412 else 2413 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 2414 Result = new (Context) ReturnStmt(ReturnLoc); 2415 } else { 2416 const VarDecl *NRVOCandidate = 0; 2417 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 2418 // we have a non-void function with an expression, continue checking 2419 2420 if (!RelatedRetType.isNull()) { 2421 // If we have a related result type, perform an extra conversion here. 2422 // FIXME: The diagnostics here don't really describe what is happening. 2423 InitializedEntity Entity = 2424 InitializedEntity::InitializeTemporary(RelatedRetType); 2425 2426 ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), 2427 RetValExp); 2428 if (Res.isInvalid()) { 2429 // FIXME: Cleanup temporaries here, anyway? 2430 return StmtError(); 2431 } 2432 RetValExp = Res.takeAs<Expr>(); 2433 } 2434 2435 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2436 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2437 // function return. 2438 2439 // In C++ the return statement is handled via a copy initialization, 2440 // the C version of which boils down to CheckSingleAssignmentConstraints. 2441 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2442 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2443 FnRetType, 2444 NRVOCandidate != 0); 2445 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2446 FnRetType, RetValExp); 2447 if (Res.isInvalid()) { 2448 // FIXME: Cleanup temporaries here, anyway? 2449 return StmtError(); 2450 } 2451 2452 RetValExp = Res.takeAs<Expr>(); 2453 if (RetValExp) 2454 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2455 } 2456 2457 if (RetValExp) { 2458 CheckImplicitConversions(RetValExp, ReturnLoc); 2459 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2460 } 2461 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 2462 } 2463 2464 // If we need to check for the named return value optimization, save the 2465 // return statement in our scope for later processing. 2466 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2467 !CurContext->isDependentContext()) 2468 FunctionScopes.back()->Returns.push_back(Result); 2469 2470 return Owned(Result); 2471} 2472 2473/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 2474/// ignore "noop" casts in places where an lvalue is required by an inline asm. 2475/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 2476/// provide a strong guidance to not use it. 2477/// 2478/// This method checks to see if the argument is an acceptable l-value and 2479/// returns false if it is a case we can handle. 2480static bool CheckAsmLValue(const Expr *E, Sema &S) { 2481 // Type dependent expressions will be checked during instantiation. 2482 if (E->isTypeDependent()) 2483 return false; 2484 2485 if (E->isLValue()) 2486 return false; // Cool, this is an lvalue. 2487 2488 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 2489 // are supposed to allow. 2490 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 2491 if (E != E2 && E2->isLValue()) { 2492 if (!S.getLangOpts().HeinousExtensions) 2493 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 2494 << E->getSourceRange(); 2495 else 2496 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 2497 << E->getSourceRange(); 2498 // Accept, even if we emitted an error diagnostic. 2499 return false; 2500 } 2501 2502 // None of the above, just randomly invalid non-lvalue. 2503 return true; 2504} 2505 2506/// isOperandMentioned - Return true if the specified operand # is mentioned 2507/// anywhere in the decomposed asm string. 2508static bool isOperandMentioned(unsigned OpNo, 2509 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 2510 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 2511 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 2512 if (!Piece.isOperand()) continue; 2513 2514 // If this is a reference to the input and if the input was the smaller 2515 // one, then we have to reject this asm. 2516 if (Piece.getOperandNo() == OpNo) 2517 return true; 2518 } 2519 return false; 2520} 2521 2522StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 2523 bool IsVolatile, unsigned NumOutputs, 2524 unsigned NumInputs, IdentifierInfo **Names, 2525 MultiExprArg constraints, MultiExprArg exprs, 2526 Expr *asmString, MultiExprArg clobbers, 2527 SourceLocation RParenLoc, bool MSAsm) { 2528 unsigned NumClobbers = clobbers.size(); 2529 StringLiteral **Constraints = 2530 reinterpret_cast<StringLiteral**>(constraints.get()); 2531 Expr **Exprs = exprs.get(); 2532 StringLiteral *AsmString = cast<StringLiteral>(asmString); 2533 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 2534 2535 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2536 2537 // The parser verifies that there is a string literal here. 2538 if (!AsmString->isAscii()) 2539 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2540 << AsmString->getSourceRange()); 2541 2542 for (unsigned i = 0; i != NumOutputs; i++) { 2543 StringLiteral *Literal = Constraints[i]; 2544 if (!Literal->isAscii()) 2545 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2546 << Literal->getSourceRange()); 2547 2548 StringRef OutputName; 2549 if (Names[i]) 2550 OutputName = Names[i]->getName(); 2551 2552 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2553 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2554 return StmtError(Diag(Literal->getLocStart(), 2555 diag::err_asm_invalid_output_constraint) 2556 << Info.getConstraintStr()); 2557 2558 // Check that the output exprs are valid lvalues. 2559 Expr *OutputExpr = Exprs[i]; 2560 if (CheckAsmLValue(OutputExpr, *this)) { 2561 return StmtError(Diag(OutputExpr->getLocStart(), 2562 diag::err_asm_invalid_lvalue_in_output) 2563 << OutputExpr->getSourceRange()); 2564 } 2565 2566 OutputConstraintInfos.push_back(Info); 2567 } 2568 2569 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2570 2571 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2572 StringLiteral *Literal = Constraints[i]; 2573 if (!Literal->isAscii()) 2574 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2575 << Literal->getSourceRange()); 2576 2577 StringRef InputName; 2578 if (Names[i]) 2579 InputName = Names[i]->getName(); 2580 2581 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2582 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2583 NumOutputs, Info)) { 2584 return StmtError(Diag(Literal->getLocStart(), 2585 diag::err_asm_invalid_input_constraint) 2586 << Info.getConstraintStr()); 2587 } 2588 2589 Expr *InputExpr = Exprs[i]; 2590 2591 // Only allow void types for memory constraints. 2592 if (Info.allowsMemory() && !Info.allowsRegister()) { 2593 if (CheckAsmLValue(InputExpr, *this)) 2594 return StmtError(Diag(InputExpr->getLocStart(), 2595 diag::err_asm_invalid_lvalue_in_input) 2596 << Info.getConstraintStr() 2597 << InputExpr->getSourceRange()); 2598 } 2599 2600 if (Info.allowsRegister()) { 2601 if (InputExpr->getType()->isVoidType()) { 2602 return StmtError(Diag(InputExpr->getLocStart(), 2603 diag::err_asm_invalid_type_in_input) 2604 << InputExpr->getType() << Info.getConstraintStr() 2605 << InputExpr->getSourceRange()); 2606 } 2607 } 2608 2609 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2610 if (Result.isInvalid()) 2611 return StmtError(); 2612 2613 Exprs[i] = Result.take(); 2614 InputConstraintInfos.push_back(Info); 2615 } 2616 2617 // Check that the clobbers are valid. 2618 for (unsigned i = 0; i != NumClobbers; i++) { 2619 StringLiteral *Literal = Clobbers[i]; 2620 if (!Literal->isAscii()) 2621 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2622 << Literal->getSourceRange()); 2623 2624 StringRef Clobber = Literal->getString(); 2625 2626 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2627 return StmtError(Diag(Literal->getLocStart(), 2628 diag::err_asm_unknown_register_name) << Clobber); 2629 } 2630 2631 AsmStmt *NS = 2632 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2633 NumOutputs, NumInputs, Names, Constraints, Exprs, 2634 AsmString, NumClobbers, Clobbers, RParenLoc); 2635 // Validate the asm string, ensuring it makes sense given the operands we 2636 // have. 2637 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2638 unsigned DiagOffs; 2639 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2640 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2641 << AsmString->getSourceRange(); 2642 return StmtError(); 2643 } 2644 2645 // Validate tied input operands for type mismatches. 2646 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2647 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2648 2649 // If this is a tied constraint, verify that the output and input have 2650 // either exactly the same type, or that they are int/ptr operands with the 2651 // same size (int/long, int*/long, are ok etc). 2652 if (!Info.hasTiedOperand()) continue; 2653 2654 unsigned TiedTo = Info.getTiedOperand(); 2655 unsigned InputOpNo = i+NumOutputs; 2656 Expr *OutputExpr = Exprs[TiedTo]; 2657 Expr *InputExpr = Exprs[InputOpNo]; 2658 2659 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) 2660 continue; 2661 2662 QualType InTy = InputExpr->getType(); 2663 QualType OutTy = OutputExpr->getType(); 2664 if (Context.hasSameType(InTy, OutTy)) 2665 continue; // All types can be tied to themselves. 2666 2667 // Decide if the input and output are in the same domain (integer/ptr or 2668 // floating point. 2669 enum AsmDomain { 2670 AD_Int, AD_FP, AD_Other 2671 } InputDomain, OutputDomain; 2672 2673 if (InTy->isIntegerType() || InTy->isPointerType()) 2674 InputDomain = AD_Int; 2675 else if (InTy->isRealFloatingType()) 2676 InputDomain = AD_FP; 2677 else 2678 InputDomain = AD_Other; 2679 2680 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2681 OutputDomain = AD_Int; 2682 else if (OutTy->isRealFloatingType()) 2683 OutputDomain = AD_FP; 2684 else 2685 OutputDomain = AD_Other; 2686 2687 // They are ok if they are the same size and in the same domain. This 2688 // allows tying things like: 2689 // void* to int* 2690 // void* to int if they are the same size. 2691 // double to long double if they are the same size. 2692 // 2693 uint64_t OutSize = Context.getTypeSize(OutTy); 2694 uint64_t InSize = Context.getTypeSize(InTy); 2695 if (OutSize == InSize && InputDomain == OutputDomain && 2696 InputDomain != AD_Other) 2697 continue; 2698 2699 // If the smaller input/output operand is not mentioned in the asm string, 2700 // then we can promote the smaller one to a larger input and the asm string 2701 // won't notice. 2702 bool SmallerValueMentioned = false; 2703 2704 // If this is a reference to the input and if the input was the smaller 2705 // one, then we have to reject this asm. 2706 if (isOperandMentioned(InputOpNo, Pieces)) { 2707 // This is a use in the asm string of the smaller operand. Since we 2708 // codegen this by promoting to a wider value, the asm will get printed 2709 // "wrong". 2710 SmallerValueMentioned |= InSize < OutSize; 2711 } 2712 if (isOperandMentioned(TiedTo, Pieces)) { 2713 // If this is a reference to the output, and if the output is the larger 2714 // value, then it's ok because we'll promote the input to the larger type. 2715 SmallerValueMentioned |= OutSize < InSize; 2716 } 2717 2718 // If the smaller value wasn't mentioned in the asm string, and if the 2719 // output was a register, just extend the shorter one to the size of the 2720 // larger one. 2721 if (!SmallerValueMentioned && InputDomain != AD_Other && 2722 OutputConstraintInfos[TiedTo].allowsRegister()) 2723 continue; 2724 2725 // Either both of the operands were mentioned or the smaller one was 2726 // mentioned. One more special case that we'll allow: if the tied input is 2727 // integer, unmentioned, and is a constant, then we'll allow truncating it 2728 // down to the size of the destination. 2729 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2730 !isOperandMentioned(InputOpNo, Pieces) && 2731 InputExpr->isEvaluatable(Context)) { 2732 CastKind castKind = 2733 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2734 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2735 Exprs[InputOpNo] = InputExpr; 2736 NS->setInputExpr(i, InputExpr); 2737 continue; 2738 } 2739 2740 Diag(InputExpr->getLocStart(), 2741 diag::err_asm_tying_incompatible_types) 2742 << InTy << OutTy << OutputExpr->getSourceRange() 2743 << InputExpr->getSourceRange(); 2744 return StmtError(); 2745 } 2746 2747 return Owned(NS); 2748} 2749 2750// needSpaceAsmToken - This function handles whitespace around asm punctuation. 2751// Returns true if a space should be emitted. 2752// 2753// FIXME: This is replicated in ParseStmt.cpp. Maybe we should defer building 2754// the AsmString (i.e., non-patched AsmString) until Sema. 2755static inline bool needSpaceAsmToken(Token currTok) { 2756 static Token prevTok; 2757 2758 // No need for space after prevToken. 2759 switch(prevTok.getKind()) { 2760 default: 2761 break; 2762 case tok::l_square: 2763 case tok::r_square: 2764 case tok::l_brace: 2765 case tok::r_brace: 2766 case tok::colon: 2767 prevTok = currTok; 2768 return false; 2769 } 2770 2771 // No need for a space before currToken. 2772 switch(currTok.getKind()) { 2773 default: 2774 break; 2775 case tok::l_square: 2776 case tok::r_square: 2777 case tok::l_brace: 2778 case tok::r_brace: 2779 case tok::comma: 2780 case tok::colon: 2781 prevTok = currTok; 2782 return false; 2783 } 2784 prevTok = currTok; 2785 return true; 2786} 2787 2788static std::string PatchMSAsmString(Sema &SemaRef, bool &IsSimple, 2789 SourceLocation AsmLoc, 2790 ArrayRef<Token> AsmToks, 2791 const TargetInfo &TI) { 2792 std::string Res; 2793 IdentifierInfo *II = AsmToks[0].getIdentifierInfo(); 2794 Res = II->getName().str(); 2795 2796 // Assume simple asm stmt until we parse a non-register identifer. 2797 IsSimple = true; 2798 2799 // Check the operands. 2800 for (unsigned i = 1, e = AsmToks.size(); i != e; ++i) { 2801 if (needSpaceAsmToken(AsmToks[i])) 2802 Res += " "; 2803 2804 switch (AsmToks[i].getKind()) { 2805 default: 2806 //llvm_unreachable("Unknown token."); 2807 break; 2808 case tok::comma: Res += ","; break; 2809 case tok::colon: Res += ":"; break; 2810 case tok::l_square: Res += "["; break; 2811 case tok::r_square: Res += "]"; break; 2812 case tok::l_brace: Res += "{"; break; 2813 case tok::r_brace: Res += "}"; break; 2814 case tok::numeric_constant: { 2815 SmallString<32> TokenBuf; 2816 TokenBuf.resize(32); 2817 bool StringInvalid = false; 2818 const char *ThisTokBuf = &TokenBuf[0]; 2819 unsigned ThisTokLen = 2820 Lexer::getSpelling(AsmToks[i], ThisTokBuf, SemaRef.getSourceManager(), 2821 SemaRef.getLangOpts(), &StringInvalid); 2822 Res += StringRef(ThisTokBuf, ThisTokLen); 2823 break; 2824 } 2825 case tok::identifier: { 2826 II = AsmToks[i].getIdentifierInfo(); 2827 StringRef Name = II->getName(); 2828 2829 // Valid registers don't need modification. 2830 if (TI.isValidGCCRegisterName(Name)) { 2831 Res += Name; 2832 break; 2833 } 2834 2835 // TODO: Lookup the identifier. 2836 IsSimple = false; 2837 } 2838 } // AsmToks[i].getKind() 2839 } 2840 return Res; 2841} 2842 2843StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, 2844 ArrayRef<Token> AsmToks, 2845 std::string &AsmString, 2846 SourceLocation EndLoc) { 2847 // MS-style inline assembly is not fully supported, so emit a warning. 2848 Diag(AsmLoc, diag::warn_unsupported_msasm); 2849 2850 bool IsSimple; 2851 // Rewrite operands to appease the AsmParser. 2852 std::string PatchedAsmString = 2853 PatchMSAsmString(*this, IsSimple, AsmLoc, AsmToks, Context.getTargetInfo()); 2854 2855 // Silence compiler warnings. Eventually, the PatchedAsmString will be 2856 // passed to the AsmParser. 2857 (void)PatchedAsmString; 2858 2859 MSAsmStmt *NS = 2860 new (Context) MSAsmStmt(Context, AsmLoc, IsSimple, /* IsVolatile */ true, 2861 AsmToks, AsmString, EndLoc); 2862 2863 return Owned(NS); 2864} 2865 2866StmtResult 2867Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2868 SourceLocation RParen, Decl *Parm, 2869 Stmt *Body) { 2870 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2871 if (Var && Var->isInvalidDecl()) 2872 return StmtError(); 2873 2874 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2875} 2876 2877StmtResult 2878Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2879 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2880} 2881 2882StmtResult 2883Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2884 MultiStmtArg CatchStmts, Stmt *Finally) { 2885 if (!getLangOpts().ObjCExceptions) 2886 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2887 2888 getCurFunction()->setHasBranchProtectedScope(); 2889 unsigned NumCatchStmts = CatchStmts.size(); 2890 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2891 CatchStmts.release(), 2892 NumCatchStmts, 2893 Finally)); 2894} 2895 2896StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) { 2897 if (Throw) { 2898 ExprResult Result = DefaultLvalueConversion(Throw); 2899 if (Result.isInvalid()) 2900 return StmtError(); 2901 2902 Throw = MaybeCreateExprWithCleanups(Result.take()); 2903 QualType ThrowType = Throw->getType(); 2904 // Make sure the expression type is an ObjC pointer or "void *". 2905 if (!ThrowType->isDependentType() && 2906 !ThrowType->isObjCObjectPointerType()) { 2907 const PointerType *PT = ThrowType->getAs<PointerType>(); 2908 if (!PT || !PT->getPointeeType()->isVoidType()) 2909 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2910 << Throw->getType() << Throw->getSourceRange()); 2911 } 2912 } 2913 2914 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2915} 2916 2917StmtResult 2918Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2919 Scope *CurScope) { 2920 if (!getLangOpts().ObjCExceptions) 2921 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2922 2923 if (!Throw) { 2924 // @throw without an expression designates a rethrow (which much occur 2925 // in the context of an @catch clause). 2926 Scope *AtCatchParent = CurScope; 2927 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2928 AtCatchParent = AtCatchParent->getParent(); 2929 if (!AtCatchParent) 2930 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2931 } 2932 return BuildObjCAtThrowStmt(AtLoc, Throw); 2933} 2934 2935ExprResult 2936Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2937 ExprResult result = DefaultLvalueConversion(operand); 2938 if (result.isInvalid()) 2939 return ExprError(); 2940 operand = result.take(); 2941 2942 // Make sure the expression type is an ObjC pointer or "void *". 2943 QualType type = operand->getType(); 2944 if (!type->isDependentType() && 2945 !type->isObjCObjectPointerType()) { 2946 const PointerType *pointerType = type->getAs<PointerType>(); 2947 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2948 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2949 << type << operand->getSourceRange(); 2950 } 2951 2952 // The operand to @synchronized is a full-expression. 2953 return MaybeCreateExprWithCleanups(operand); 2954} 2955 2956StmtResult 2957Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2958 Stmt *SyncBody) { 2959 // We can't jump into or indirect-jump out of a @synchronized block. 2960 getCurFunction()->setHasBranchProtectedScope(); 2961 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2962} 2963 2964/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2965/// and creates a proper catch handler from them. 2966StmtResult 2967Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2968 Stmt *HandlerBlock) { 2969 // There's nothing to test that ActOnExceptionDecl didn't already test. 2970 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2971 cast_or_null<VarDecl>(ExDecl), 2972 HandlerBlock)); 2973} 2974 2975StmtResult 2976Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2977 getCurFunction()->setHasBranchProtectedScope(); 2978 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2979} 2980 2981namespace { 2982 2983class TypeWithHandler { 2984 QualType t; 2985 CXXCatchStmt *stmt; 2986public: 2987 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2988 : t(type), stmt(statement) {} 2989 2990 // An arbitrary order is fine as long as it places identical 2991 // types next to each other. 2992 bool operator<(const TypeWithHandler &y) const { 2993 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2994 return true; 2995 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2996 return false; 2997 else 2998 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2999 } 3000 3001 bool operator==(const TypeWithHandler& other) const { 3002 return t == other.t; 3003 } 3004 3005 CXXCatchStmt *getCatchStmt() const { return stmt; } 3006 SourceLocation getTypeSpecStartLoc() const { 3007 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 3008 } 3009}; 3010 3011} 3012 3013/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 3014/// handlers and creates a try statement from them. 3015StmtResult 3016Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 3017 MultiStmtArg RawHandlers) { 3018 // Don't report an error if 'try' is used in system headers. 3019 if (!getLangOpts().CXXExceptions && 3020 !getSourceManager().isInSystemHeader(TryLoc)) 3021 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 3022 3023 unsigned NumHandlers = RawHandlers.size(); 3024 assert(NumHandlers > 0 && 3025 "The parser shouldn't call this if there are no handlers."); 3026 Stmt **Handlers = RawHandlers.get(); 3027 3028 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 3029 3030 for (unsigned i = 0; i < NumHandlers; ++i) { 3031 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 3032 if (!Handler->getExceptionDecl()) { 3033 if (i < NumHandlers - 1) 3034 return StmtError(Diag(Handler->getLocStart(), 3035 diag::err_early_catch_all)); 3036 3037 continue; 3038 } 3039 3040 const QualType CaughtType = Handler->getCaughtType(); 3041 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 3042 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 3043 } 3044 3045 // Detect handlers for the same type as an earlier one. 3046 if (NumHandlers > 1) { 3047 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 3048 3049 TypeWithHandler prev = TypesWithHandlers[0]; 3050 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 3051 TypeWithHandler curr = TypesWithHandlers[i]; 3052 3053 if (curr == prev) { 3054 Diag(curr.getTypeSpecStartLoc(), 3055 diag::warn_exception_caught_by_earlier_handler) 3056 << curr.getCatchStmt()->getCaughtType().getAsString(); 3057 Diag(prev.getTypeSpecStartLoc(), 3058 diag::note_previous_exception_handler) 3059 << prev.getCatchStmt()->getCaughtType().getAsString(); 3060 } 3061 3062 prev = curr; 3063 } 3064 } 3065 3066 getCurFunction()->setHasBranchProtectedScope(); 3067 3068 // FIXME: We should detect handlers that cannot catch anything because an 3069 // earlier handler catches a superclass. Need to find a method that is not 3070 // quadratic for this. 3071 // Neither of these are explicitly forbidden, but every compiler detects them 3072 // and warns. 3073 3074 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 3075 Handlers, NumHandlers)); 3076} 3077 3078StmtResult 3079Sema::ActOnSEHTryBlock(bool IsCXXTry, 3080 SourceLocation TryLoc, 3081 Stmt *TryBlock, 3082 Stmt *Handler) { 3083 assert(TryBlock && Handler); 3084 3085 getCurFunction()->setHasBranchProtectedScope(); 3086 3087 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 3088} 3089 3090StmtResult 3091Sema::ActOnSEHExceptBlock(SourceLocation Loc, 3092 Expr *FilterExpr, 3093 Stmt *Block) { 3094 assert(FilterExpr && Block); 3095 3096 if(!FilterExpr->getType()->isIntegerType()) { 3097 return StmtError(Diag(FilterExpr->getExprLoc(), 3098 diag::err_filter_expression_integral) 3099 << FilterExpr->getType()); 3100 } 3101 3102 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 3103} 3104 3105StmtResult 3106Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 3107 Stmt *Block) { 3108 assert(Block); 3109 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 3110} 3111 3112StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, 3113 bool IsIfExists, 3114 NestedNameSpecifierLoc QualifierLoc, 3115 DeclarationNameInfo NameInfo, 3116 Stmt *Nested) 3117{ 3118 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, 3119 QualifierLoc, NameInfo, 3120 cast<CompoundStmt>(Nested)); 3121} 3122 3123 3124StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, 3125 bool IsIfExists, 3126 CXXScopeSpec &SS, 3127 UnqualifiedId &Name, 3128 Stmt *Nested) { 3129 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, 3130 SS.getWithLocInContext(Context), 3131 GetNameFromUnqualifiedId(Name), 3132 Nested); 3133} 3134