SemaStmt.cpp revision 856d3798af7c2f7251e4a295f3da7a09ce4c62ab
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/APValue.h" 20#include "clang/AST/ASTContext.h" 21#include "clang/AST/DeclObjC.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/ExprObjC.h" 24#include "clang/AST/StmtObjC.h" 25#include "clang/AST/StmtCXX.h" 26#include "clang/AST/TypeLoc.h" 27#include "clang/Lex/Preprocessor.h" 28#include "clang/Basic/TargetInfo.h" 29#include "llvm/ADT/ArrayRef.h" 30#include "llvm/ADT/STLExtras.h" 31#include "llvm/ADT/SmallVector.h" 32using namespace clang; 33using namespace sema; 34 35StmtResult Sema::ActOnExprStmt(FullExprArg expr) { 36 Expr *E = expr.get(); 37 if (!E) // FIXME: FullExprArg has no error state? 38 return StmtError(); 39 40 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 41 // void expression for its side effects. Conversion to void allows any 42 // operand, even incomplete types. 43 44 // Same thing in for stmt first clause (when expr) and third clause. 45 return Owned(static_cast<Stmt*>(E)); 46} 47 48 49StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, 50 SourceLocation LeadingEmptyMacroLoc) { 51 return Owned(new (Context) NullStmt(SemiLoc, LeadingEmptyMacroLoc)); 52} 53 54StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, 55 SourceLocation EndLoc) { 56 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 57 58 // If we have an invalid decl, just return an error. 59 if (DG.isNull()) return StmtError(); 60 61 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 62} 63 64void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { 65 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 66 67 // If we have an invalid decl, just return. 68 if (DG.isNull() || !DG.isSingleDecl()) return; 69 VarDecl *var = cast<VarDecl>(DG.getSingleDecl()); 70 71 // suppress any potential 'unused variable' warning. 72 var->setUsed(); 73 74 // In ARC, we don't want to lifetime for the iteration 75 // variable of a fast enumeration loop. Rather than actually 76 // trying to catch that during declaration processing, we 77 // remove the consequences here. 78 if (getLangOptions().ObjCAutoRefCount) { 79 SplitQualType split = var->getType().split(); 80 81 // Inferred lifetime will show up as a local qualifier because 82 // explicit lifetime would have shown up as an AttributedType 83 // instead. 84 if (split.second.hasObjCLifetime()) { 85 // Change the qualification to 'const __unsafe_unretained'. 86 split.second.setObjCLifetime(Qualifiers::OCL_ExplicitNone); 87 split.second.addConst(); 88 var->setType(Context.getQualifiedType(split.first, split.second)); 89 var->setInit(0); 90 } 91 } 92} 93 94void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 95 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 96 return DiagnoseUnusedExprResult(Label->getSubStmt()); 97 98 const Expr *E = dyn_cast_or_null<Expr>(S); 99 if (!E) 100 return; 101 102 SourceLocation Loc; 103 SourceRange R1, R2; 104 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context)) 105 return; 106 107 // Okay, we have an unused result. Depending on what the base expression is, 108 // we might want to make a more specific diagnostic. Check for one of these 109 // cases now. 110 unsigned DiagID = diag::warn_unused_expr; 111 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 112 E = Temps->getSubExpr(); 113 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 114 E = TempExpr->getSubExpr(); 115 116 E = E->IgnoreParenImpCasts(); 117 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 118 if (E->getType()->isVoidType()) 119 return; 120 121 // If the callee has attribute pure, const, or warn_unused_result, warn with 122 // a more specific message to make it clear what is happening. 123 if (const Decl *FD = CE->getCalleeDecl()) { 124 if (FD->getAttr<WarnUnusedResultAttr>()) { 125 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result"; 126 return; 127 } 128 if (FD->getAttr<PureAttr>()) { 129 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 130 return; 131 } 132 if (FD->getAttr<ConstAttr>()) { 133 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 134 return; 135 } 136 } 137 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 138 if (getLangOptions().ObjCAutoRefCount && ME->isDelegateInitCall()) { 139 Diag(Loc, diag::err_arc_unused_init_message) << R1; 140 return; 141 } 142 const ObjCMethodDecl *MD = ME->getMethodDecl(); 143 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 144 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result"; 145 return; 146 } 147 } else if (isa<ObjCPropertyRefExpr>(E)) { 148 DiagID = diag::warn_unused_property_expr; 149 } else if (const CXXFunctionalCastExpr *FC 150 = dyn_cast<CXXFunctionalCastExpr>(E)) { 151 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 152 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 153 return; 154 } 155 // Diagnose "(void*) blah" as a typo for "(void) blah". 156 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 157 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 158 QualType T = TI->getType(); 159 160 // We really do want to use the non-canonical type here. 161 if (T == Context.VoidPtrTy) { 162 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 163 164 Diag(Loc, diag::warn_unused_voidptr) 165 << FixItHint::CreateRemoval(TL.getStarLoc()); 166 return; 167 } 168 } 169 170 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 171} 172 173StmtResult 174Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 175 MultiStmtArg elts, bool isStmtExpr) { 176 unsigned NumElts = elts.size(); 177 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 178 // If we're in C89 mode, check that we don't have any decls after stmts. If 179 // so, emit an extension diagnostic. 180 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 181 // Note that __extension__ can be around a decl. 182 unsigned i = 0; 183 // Skip over all declarations. 184 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 185 /*empty*/; 186 187 // We found the end of the list or a statement. Scan for another declstmt. 188 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 189 /*empty*/; 190 191 if (i != NumElts) { 192 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 193 Diag(D->getLocation(), diag::ext_mixed_decls_code); 194 } 195 } 196 // Warn about unused expressions in statements. 197 for (unsigned i = 0; i != NumElts; ++i) { 198 // Ignore statements that are last in a statement expression. 199 if (isStmtExpr && i == NumElts - 1) 200 continue; 201 202 DiagnoseUnusedExprResult(Elts[i]); 203 } 204 205 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 206} 207 208StmtResult 209Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 210 SourceLocation DotDotDotLoc, Expr *RHSVal, 211 SourceLocation ColonLoc) { 212 assert((LHSVal != 0) && "missing expression in case statement"); 213 214 // C99 6.8.4.2p3: The expression shall be an integer constant. 215 // However, GCC allows any evaluatable integer expression. 216 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && 217 VerifyIntegerConstantExpression(LHSVal)) 218 return StmtError(); 219 220 // GCC extension: The expression shall be an integer constant. 221 222 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && 223 VerifyIntegerConstantExpression(RHSVal)) { 224 RHSVal = 0; // Recover by just forgetting about it. 225 } 226 227 if (getCurFunction()->SwitchStack.empty()) { 228 Diag(CaseLoc, diag::err_case_not_in_switch); 229 return StmtError(); 230 } 231 232 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 233 ColonLoc); 234 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 235 return Owned(CS); 236} 237 238/// ActOnCaseStmtBody - This installs a statement as the body of a case. 239void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 240 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 241 CS->setSubStmt(SubStmt); 242} 243 244StmtResult 245Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 246 Stmt *SubStmt, Scope *CurScope) { 247 if (getCurFunction()->SwitchStack.empty()) { 248 Diag(DefaultLoc, diag::err_default_not_in_switch); 249 return Owned(SubStmt); 250 } 251 252 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 253 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 254 return Owned(DS); 255} 256 257StmtResult 258Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 259 SourceLocation ColonLoc, Stmt *SubStmt) { 260 261 // If the label was multiply defined, reject it now. 262 if (TheDecl->getStmt()) { 263 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 264 Diag(TheDecl->getLocation(), diag::note_previous_definition); 265 return Owned(SubStmt); 266 } 267 268 // Otherwise, things are good. Fill in the declaration and return it. 269 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 270 TheDecl->setStmt(LS); 271 if (!TheDecl->isGnuLocal()) 272 TheDecl->setLocation(IdentLoc); 273 return Owned(LS); 274} 275 276StmtResult 277Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 278 Stmt *thenStmt, SourceLocation ElseLoc, 279 Stmt *elseStmt) { 280 ExprResult CondResult(CondVal.release()); 281 282 VarDecl *ConditionVar = 0; 283 if (CondVar) { 284 ConditionVar = cast<VarDecl>(CondVar); 285 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 286 if (CondResult.isInvalid()) 287 return StmtError(); 288 } 289 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 290 if (!ConditionExpr) 291 return StmtError(); 292 293 DiagnoseUnusedExprResult(thenStmt); 294 295 // Warn if the if block has a null body without an else value. 296 // this helps prevent bugs due to typos, such as 297 // if (condition); 298 // do_stuff(); 299 // 300 if (!elseStmt) { 301 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 302 // But do not warn if the body is a macro that expands to nothing, e.g: 303 // 304 // #define CALL(x) 305 // if (condition) 306 // CALL(0); 307 // 308 if (!stmt->hasLeadingEmptyMacro()) 309 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 310 } 311 312 DiagnoseUnusedExprResult(elseStmt); 313 314 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 315 thenStmt, ElseLoc, elseStmt)); 316} 317 318/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 319/// the specified width and sign. If an overflow occurs, detect it and emit 320/// the specified diagnostic. 321void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 322 unsigned NewWidth, bool NewSign, 323 SourceLocation Loc, 324 unsigned DiagID) { 325 // Perform a conversion to the promoted condition type if needed. 326 if (NewWidth > Val.getBitWidth()) { 327 // If this is an extension, just do it. 328 Val = Val.extend(NewWidth); 329 Val.setIsSigned(NewSign); 330 331 // If the input was signed and negative and the output is 332 // unsigned, don't bother to warn: this is implementation-defined 333 // behavior. 334 // FIXME: Introduce a second, default-ignored warning for this case? 335 } else if (NewWidth < Val.getBitWidth()) { 336 // If this is a truncation, check for overflow. 337 llvm::APSInt ConvVal(Val); 338 ConvVal = ConvVal.trunc(NewWidth); 339 ConvVal.setIsSigned(NewSign); 340 ConvVal = ConvVal.extend(Val.getBitWidth()); 341 ConvVal.setIsSigned(Val.isSigned()); 342 if (ConvVal != Val) 343 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 344 345 // Regardless of whether a diagnostic was emitted, really do the 346 // truncation. 347 Val = Val.trunc(NewWidth); 348 Val.setIsSigned(NewSign); 349 } else if (NewSign != Val.isSigned()) { 350 // Convert the sign to match the sign of the condition. This can cause 351 // overflow as well: unsigned(INTMIN) 352 // We don't diagnose this overflow, because it is implementation-defined 353 // behavior. 354 // FIXME: Introduce a second, default-ignored warning for this case? 355 llvm::APSInt OldVal(Val); 356 Val.setIsSigned(NewSign); 357 } 358} 359 360namespace { 361 struct CaseCompareFunctor { 362 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 363 const llvm::APSInt &RHS) { 364 return LHS.first < RHS; 365 } 366 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 367 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 368 return LHS.first < RHS.first; 369 } 370 bool operator()(const llvm::APSInt &LHS, 371 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 372 return LHS < RHS.first; 373 } 374 }; 375} 376 377/// CmpCaseVals - Comparison predicate for sorting case values. 378/// 379static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 380 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 381 if (lhs.first < rhs.first) 382 return true; 383 384 if (lhs.first == rhs.first && 385 lhs.second->getCaseLoc().getRawEncoding() 386 < rhs.second->getCaseLoc().getRawEncoding()) 387 return true; 388 return false; 389} 390 391/// CmpEnumVals - Comparison predicate for sorting enumeration values. 392/// 393static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 394 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 395{ 396 return lhs.first < rhs.first; 397} 398 399/// EqEnumVals - Comparison preficate for uniqing enumeration values. 400/// 401static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 402 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 403{ 404 return lhs.first == rhs.first; 405} 406 407/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 408/// potentially integral-promoted expression @p expr. 409static QualType GetTypeBeforeIntegralPromotion(const Expr* expr) { 410 if (const CastExpr *ImplicitCast = dyn_cast<ImplicitCastExpr>(expr)) { 411 const Expr *ExprBeforePromotion = ImplicitCast->getSubExpr(); 412 QualType TypeBeforePromotion = ExprBeforePromotion->getType(); 413 if (TypeBeforePromotion->isIntegralOrEnumerationType()) { 414 return TypeBeforePromotion; 415 } 416 } 417 return expr->getType(); 418} 419 420StmtResult 421Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 422 Decl *CondVar) { 423 ExprResult CondResult; 424 425 VarDecl *ConditionVar = 0; 426 if (CondVar) { 427 ConditionVar = cast<VarDecl>(CondVar); 428 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 429 if (CondResult.isInvalid()) 430 return StmtError(); 431 432 Cond = CondResult.release(); 433 } 434 435 if (!Cond) 436 return StmtError(); 437 438 CondResult 439 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, 440 PDiag(diag::err_typecheck_statement_requires_integer), 441 PDiag(diag::err_switch_incomplete_class_type) 442 << Cond->getSourceRange(), 443 PDiag(diag::err_switch_explicit_conversion), 444 PDiag(diag::note_switch_conversion), 445 PDiag(diag::err_switch_multiple_conversions), 446 PDiag(diag::note_switch_conversion), 447 PDiag(0)); 448 if (CondResult.isInvalid()) return StmtError(); 449 Cond = CondResult.take(); 450 451 if (!CondVar) { 452 CheckImplicitConversions(Cond, SwitchLoc); 453 CondResult = MaybeCreateExprWithCleanups(Cond); 454 if (CondResult.isInvalid()) 455 return StmtError(); 456 Cond = CondResult.take(); 457 } 458 459 getCurFunction()->setHasBranchIntoScope(); 460 461 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 462 getCurFunction()->SwitchStack.push_back(SS); 463 return Owned(SS); 464} 465 466static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 467 if (Val.getBitWidth() < BitWidth) 468 Val = Val.extend(BitWidth); 469 else if (Val.getBitWidth() > BitWidth) 470 Val = Val.trunc(BitWidth); 471 Val.setIsSigned(IsSigned); 472} 473 474StmtResult 475Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 476 Stmt *BodyStmt) { 477 SwitchStmt *SS = cast<SwitchStmt>(Switch); 478 assert(SS == getCurFunction()->SwitchStack.back() && 479 "switch stack missing push/pop!"); 480 481 SS->setBody(BodyStmt, SwitchLoc); 482 getCurFunction()->SwitchStack.pop_back(); 483 484 if (SS->getCond() == 0) 485 return StmtError(); 486 487 Expr *CondExpr = SS->getCond(); 488 Expr *CondExprBeforePromotion = CondExpr; 489 QualType CondTypeBeforePromotion = 490 GetTypeBeforeIntegralPromotion(CondExpr); 491 492 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 493 ExprResult CondResult = UsualUnaryConversions(CondExpr); 494 if (CondResult.isInvalid()) 495 return StmtError(); 496 CondExpr = CondResult.take(); 497 QualType CondType = CondExpr->getType(); 498 SS->setCond(CondExpr); 499 500 // C++ 6.4.2.p2: 501 // Integral promotions are performed (on the switch condition). 502 // 503 // A case value unrepresentable by the original switch condition 504 // type (before the promotion) doesn't make sense, even when it can 505 // be represented by the promoted type. Therefore we need to find 506 // the pre-promotion type of the switch condition. 507 if (!CondExpr->isTypeDependent()) { 508 // We have already converted the expression to an integral or enumeration 509 // type, when we started the switch statement. If we don't have an 510 // appropriate type now, just return an error. 511 if (!CondType->isIntegralOrEnumerationType()) 512 return StmtError(); 513 514 if (CondExpr->isKnownToHaveBooleanValue()) { 515 // switch(bool_expr) {...} is often a programmer error, e.g. 516 // switch(n && mask) { ... } // Doh - should be "n & mask". 517 // One can always use an if statement instead of switch(bool_expr). 518 Diag(SwitchLoc, diag::warn_bool_switch_condition) 519 << CondExpr->getSourceRange(); 520 } 521 } 522 523 // Get the bitwidth of the switched-on value before promotions. We must 524 // convert the integer case values to this width before comparison. 525 bool HasDependentValue 526 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 527 unsigned CondWidth 528 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 529 bool CondIsSigned 530 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 531 532 // Accumulate all of the case values in a vector so that we can sort them 533 // and detect duplicates. This vector contains the APInt for the case after 534 // it has been converted to the condition type. 535 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 536 CaseValsTy CaseVals; 537 538 // Keep track of any GNU case ranges we see. The APSInt is the low value. 539 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 540 CaseRangesTy CaseRanges; 541 542 DefaultStmt *TheDefaultStmt = 0; 543 544 bool CaseListIsErroneous = false; 545 546 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 547 SC = SC->getNextSwitchCase()) { 548 549 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 550 if (TheDefaultStmt) { 551 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 552 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 553 554 // FIXME: Remove the default statement from the switch block so that 555 // we'll return a valid AST. This requires recursing down the AST and 556 // finding it, not something we are set up to do right now. For now, 557 // just lop the entire switch stmt out of the AST. 558 CaseListIsErroneous = true; 559 } 560 TheDefaultStmt = DS; 561 562 } else { 563 CaseStmt *CS = cast<CaseStmt>(SC); 564 565 // We already verified that the expression has a i-c-e value (C99 566 // 6.8.4.2p3) - get that value now. 567 Expr *Lo = CS->getLHS(); 568 569 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 570 HasDependentValue = true; 571 break; 572 } 573 574 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 575 576 // Convert the value to the same width/sign as the condition. 577 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 578 Lo->getLocStart(), 579 diag::warn_case_value_overflow); 580 581 // If the LHS is not the same type as the condition, insert an implicit 582 // cast. 583 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 584 CS->setLHS(Lo); 585 586 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 587 if (CS->getRHS()) { 588 if (CS->getRHS()->isTypeDependent() || 589 CS->getRHS()->isValueDependent()) { 590 HasDependentValue = true; 591 break; 592 } 593 CaseRanges.push_back(std::make_pair(LoVal, CS)); 594 } else 595 CaseVals.push_back(std::make_pair(LoVal, CS)); 596 } 597 } 598 599 if (!HasDependentValue) { 600 // If we don't have a default statement, check whether the 601 // condition is constant. 602 llvm::APSInt ConstantCondValue; 603 bool HasConstantCond = false; 604 bool ShouldCheckConstantCond = false; 605 if (!HasDependentValue && !TheDefaultStmt) { 606 Expr::EvalResult Result; 607 HasConstantCond = CondExprBeforePromotion->Evaluate(Result, Context); 608 if (HasConstantCond) { 609 assert(Result.Val.isInt() && "switch condition evaluated to non-int"); 610 ConstantCondValue = Result.Val.getInt(); 611 ShouldCheckConstantCond = true; 612 613 assert(ConstantCondValue.getBitWidth() == CondWidth && 614 ConstantCondValue.isSigned() == CondIsSigned); 615 } 616 } 617 618 // Sort all the scalar case values so we can easily detect duplicates. 619 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 620 621 if (!CaseVals.empty()) { 622 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 623 if (ShouldCheckConstantCond && 624 CaseVals[i].first == ConstantCondValue) 625 ShouldCheckConstantCond = false; 626 627 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 628 // If we have a duplicate, report it. 629 Diag(CaseVals[i].second->getLHS()->getLocStart(), 630 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 631 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 632 diag::note_duplicate_case_prev); 633 // FIXME: We really want to remove the bogus case stmt from the 634 // substmt, but we have no way to do this right now. 635 CaseListIsErroneous = true; 636 } 637 } 638 } 639 640 // Detect duplicate case ranges, which usually don't exist at all in 641 // the first place. 642 if (!CaseRanges.empty()) { 643 // Sort all the case ranges by their low value so we can easily detect 644 // overlaps between ranges. 645 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 646 647 // Scan the ranges, computing the high values and removing empty ranges. 648 std::vector<llvm::APSInt> HiVals; 649 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 650 llvm::APSInt &LoVal = CaseRanges[i].first; 651 CaseStmt *CR = CaseRanges[i].second; 652 Expr *Hi = CR->getRHS(); 653 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 654 655 // Convert the value to the same width/sign as the condition. 656 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 657 Hi->getLocStart(), 658 diag::warn_case_value_overflow); 659 660 // If the LHS is not the same type as the condition, insert an implicit 661 // cast. 662 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 663 CR->setRHS(Hi); 664 665 // If the low value is bigger than the high value, the case is empty. 666 if (LoVal > HiVal) { 667 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 668 << SourceRange(CR->getLHS()->getLocStart(), 669 Hi->getLocEnd()); 670 CaseRanges.erase(CaseRanges.begin()+i); 671 --i, --e; 672 continue; 673 } 674 675 if (ShouldCheckConstantCond && 676 LoVal <= ConstantCondValue && 677 ConstantCondValue <= HiVal) 678 ShouldCheckConstantCond = false; 679 680 HiVals.push_back(HiVal); 681 } 682 683 // Rescan the ranges, looking for overlap with singleton values and other 684 // ranges. Since the range list is sorted, we only need to compare case 685 // ranges with their neighbors. 686 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 687 llvm::APSInt &CRLo = CaseRanges[i].first; 688 llvm::APSInt &CRHi = HiVals[i]; 689 CaseStmt *CR = CaseRanges[i].second; 690 691 // Check to see whether the case range overlaps with any 692 // singleton cases. 693 CaseStmt *OverlapStmt = 0; 694 llvm::APSInt OverlapVal(32); 695 696 // Find the smallest value >= the lower bound. If I is in the 697 // case range, then we have overlap. 698 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 699 CaseVals.end(), CRLo, 700 CaseCompareFunctor()); 701 if (I != CaseVals.end() && I->first < CRHi) { 702 OverlapVal = I->first; // Found overlap with scalar. 703 OverlapStmt = I->second; 704 } 705 706 // Find the smallest value bigger than the upper bound. 707 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 708 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 709 OverlapVal = (I-1)->first; // Found overlap with scalar. 710 OverlapStmt = (I-1)->second; 711 } 712 713 // Check to see if this case stmt overlaps with the subsequent 714 // case range. 715 if (i && CRLo <= HiVals[i-1]) { 716 OverlapVal = HiVals[i-1]; // Found overlap with range. 717 OverlapStmt = CaseRanges[i-1].second; 718 } 719 720 if (OverlapStmt) { 721 // If we have a duplicate, report it. 722 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 723 << OverlapVal.toString(10); 724 Diag(OverlapStmt->getLHS()->getLocStart(), 725 diag::note_duplicate_case_prev); 726 // FIXME: We really want to remove the bogus case stmt from the 727 // substmt, but we have no way to do this right now. 728 CaseListIsErroneous = true; 729 } 730 } 731 } 732 733 // Complain if we have a constant condition and we didn't find a match. 734 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 735 // TODO: it would be nice if we printed enums as enums, chars as 736 // chars, etc. 737 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 738 << ConstantCondValue.toString(10) 739 << CondExpr->getSourceRange(); 740 } 741 742 // Check to see if switch is over an Enum and handles all of its 743 // values. We only issue a warning if there is not 'default:', but 744 // we still do the analysis to preserve this information in the AST 745 // (which can be used by flow-based analyes). 746 // 747 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 748 749 // If switch has default case, then ignore it. 750 if (!CaseListIsErroneous && !HasConstantCond && ET) { 751 const EnumDecl *ED = ET->getDecl(); 752 typedef llvm::SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 753 EnumValsTy; 754 EnumValsTy EnumVals; 755 756 // Gather all enum values, set their type and sort them, 757 // allowing easier comparison with CaseVals. 758 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 759 EDI != ED->enumerator_end(); ++EDI) { 760 llvm::APSInt Val = EDI->getInitVal(); 761 AdjustAPSInt(Val, CondWidth, CondIsSigned); 762 EnumVals.push_back(std::make_pair(Val, *EDI)); 763 } 764 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 765 EnumValsTy::iterator EIend = 766 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 767 768 // See which case values aren't in enum. 769 // TODO: we might want to check whether case values are out of the 770 // enum even if we don't want to check whether all cases are handled. 771 if (!TheDefaultStmt) { 772 EnumValsTy::const_iterator EI = EnumVals.begin(); 773 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 774 CI != CaseVals.end(); CI++) { 775 while (EI != EIend && EI->first < CI->first) 776 EI++; 777 if (EI == EIend || EI->first > CI->first) 778 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 779 << ED->getDeclName(); 780 } 781 // See which of case ranges aren't in enum 782 EI = EnumVals.begin(); 783 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 784 RI != CaseRanges.end() && EI != EIend; RI++) { 785 while (EI != EIend && EI->first < RI->first) 786 EI++; 787 788 if (EI == EIend || EI->first != RI->first) { 789 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 790 << ED->getDeclName(); 791 } 792 793 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 794 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 795 while (EI != EIend && EI->first < Hi) 796 EI++; 797 if (EI == EIend || EI->first != Hi) 798 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 799 << ED->getDeclName(); 800 } 801 } 802 803 // Check which enum vals aren't in switch 804 CaseValsTy::const_iterator CI = CaseVals.begin(); 805 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 806 bool hasCasesNotInSwitch = false; 807 808 llvm::SmallVector<DeclarationName,8> UnhandledNames; 809 810 for (EnumValsTy::const_iterator EI = EnumVals.begin(); EI != EIend; EI++){ 811 // Drop unneeded case values 812 llvm::APSInt CIVal; 813 while (CI != CaseVals.end() && CI->first < EI->first) 814 CI++; 815 816 if (CI != CaseVals.end() && CI->first == EI->first) 817 continue; 818 819 // Drop unneeded case ranges 820 for (; RI != CaseRanges.end(); RI++) { 821 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 822 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 823 if (EI->first <= Hi) 824 break; 825 } 826 827 if (RI == CaseRanges.end() || EI->first < RI->first) { 828 hasCasesNotInSwitch = true; 829 if (!TheDefaultStmt) 830 UnhandledNames.push_back(EI->second->getDeclName()); 831 } 832 } 833 834 // Produce a nice diagnostic if multiple values aren't handled. 835 switch (UnhandledNames.size()) { 836 case 0: break; 837 case 1: 838 Diag(CondExpr->getExprLoc(), diag::warn_missing_case1) 839 << UnhandledNames[0]; 840 break; 841 case 2: 842 Diag(CondExpr->getExprLoc(), diag::warn_missing_case2) 843 << UnhandledNames[0] << UnhandledNames[1]; 844 break; 845 case 3: 846 Diag(CondExpr->getExprLoc(), diag::warn_missing_case3) 847 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 848 break; 849 default: 850 Diag(CondExpr->getExprLoc(), diag::warn_missing_cases) 851 << (unsigned)UnhandledNames.size() 852 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 853 break; 854 } 855 856 if (!hasCasesNotInSwitch) 857 SS->setAllEnumCasesCovered(); 858 } 859 } 860 861 // FIXME: If the case list was broken is some way, we don't have a good system 862 // to patch it up. Instead, just return the whole substmt as broken. 863 if (CaseListIsErroneous) 864 return StmtError(); 865 866 return Owned(SS); 867} 868 869StmtResult 870Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 871 Decl *CondVar, Stmt *Body) { 872 ExprResult CondResult(Cond.release()); 873 874 VarDecl *ConditionVar = 0; 875 if (CondVar) { 876 ConditionVar = cast<VarDecl>(CondVar); 877 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 878 if (CondResult.isInvalid()) 879 return StmtError(); 880 } 881 Expr *ConditionExpr = CondResult.take(); 882 if (!ConditionExpr) 883 return StmtError(); 884 885 DiagnoseUnusedExprResult(Body); 886 887 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 888 Body, WhileLoc)); 889} 890 891StmtResult 892Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 893 SourceLocation WhileLoc, SourceLocation CondLParen, 894 Expr *Cond, SourceLocation CondRParen) { 895 assert(Cond && "ActOnDoStmt(): missing expression"); 896 897 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 898 if (CondResult.isInvalid() || CondResult.isInvalid()) 899 return StmtError(); 900 Cond = CondResult.take(); 901 902 CheckImplicitConversions(Cond, DoLoc); 903 CondResult = MaybeCreateExprWithCleanups(Cond); 904 if (CondResult.isInvalid()) 905 return StmtError(); 906 Cond = CondResult.take(); 907 908 DiagnoseUnusedExprResult(Body); 909 910 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 911} 912 913StmtResult 914Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 915 Stmt *First, FullExprArg second, Decl *secondVar, 916 FullExprArg third, 917 SourceLocation RParenLoc, Stmt *Body) { 918 if (!getLangOptions().CPlusPlus) { 919 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 920 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 921 // declare identifiers for objects having storage class 'auto' or 922 // 'register'. 923 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 924 DI!=DE; ++DI) { 925 VarDecl *VD = dyn_cast<VarDecl>(*DI); 926 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 927 VD = 0; 928 if (VD == 0) 929 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 930 // FIXME: mark decl erroneous! 931 } 932 } 933 } 934 935 ExprResult SecondResult(second.release()); 936 VarDecl *ConditionVar = 0; 937 if (secondVar) { 938 ConditionVar = cast<VarDecl>(secondVar); 939 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 940 if (SecondResult.isInvalid()) 941 return StmtError(); 942 } 943 944 Expr *Third = third.release().takeAs<Expr>(); 945 946 DiagnoseUnusedExprResult(First); 947 DiagnoseUnusedExprResult(Third); 948 DiagnoseUnusedExprResult(Body); 949 950 return Owned(new (Context) ForStmt(Context, First, 951 SecondResult.take(), ConditionVar, 952 Third, Body, ForLoc, LParenLoc, 953 RParenLoc)); 954} 955 956/// In an Objective C collection iteration statement: 957/// for (x in y) 958/// x can be an arbitrary l-value expression. Bind it up as a 959/// full-expression. 960StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 961 CheckImplicitConversions(E); 962 ExprResult Result = MaybeCreateExprWithCleanups(E); 963 if (Result.isInvalid()) return StmtError(); 964 return Owned(static_cast<Stmt*>(Result.get())); 965} 966 967StmtResult 968Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 969 SourceLocation LParenLoc, 970 Stmt *First, Expr *Second, 971 SourceLocation RParenLoc, Stmt *Body) { 972 if (First) { 973 QualType FirstType; 974 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 975 if (!DS->isSingleDecl()) 976 return StmtError(Diag((*DS->decl_begin())->getLocation(), 977 diag::err_toomany_element_decls)); 978 979 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 980 FirstType = D->getType(); 981 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 982 // declare identifiers for objects having storage class 'auto' or 983 // 'register'. 984 if (!D->hasLocalStorage()) 985 return StmtError(Diag(D->getLocation(), 986 diag::err_non_variable_decl_in_for)); 987 } else { 988 Expr *FirstE = cast<Expr>(First); 989 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 990 return StmtError(Diag(First->getLocStart(), 991 diag::err_selector_element_not_lvalue) 992 << First->getSourceRange()); 993 994 FirstType = static_cast<Expr*>(First)->getType(); 995 } 996 if (!FirstType->isDependentType() && 997 !FirstType->isObjCObjectPointerType() && 998 !FirstType->isBlockPointerType()) 999 Diag(ForLoc, diag::err_selector_element_type) 1000 << FirstType << First->getSourceRange(); 1001 } 1002 if (Second && !Second->isTypeDependent()) { 1003 ExprResult Result = DefaultFunctionArrayLvalueConversion(Second); 1004 if (Result.isInvalid()) 1005 return StmtError(); 1006 Second = Result.take(); 1007 QualType SecondType = Second->getType(); 1008 if (!SecondType->isObjCObjectPointerType()) 1009 Diag(ForLoc, diag::err_collection_expr_type) 1010 << SecondType << Second->getSourceRange(); 1011 else if (const ObjCObjectPointerType *OPT = 1012 SecondType->getAsObjCInterfacePointerType()) { 1013 llvm::SmallVector<IdentifierInfo *, 4> KeyIdents; 1014 IdentifierInfo* selIdent = 1015 &Context.Idents.get("countByEnumeratingWithState"); 1016 KeyIdents.push_back(selIdent); 1017 selIdent = &Context.Idents.get("objects"); 1018 KeyIdents.push_back(selIdent); 1019 selIdent = &Context.Idents.get("count"); 1020 KeyIdents.push_back(selIdent); 1021 Selector CSelector = Context.Selectors.getSelector(3, &KeyIdents[0]); 1022 if (ObjCInterfaceDecl *IDecl = OPT->getInterfaceDecl()) { 1023 if (!IDecl->isForwardDecl() && 1024 !IDecl->lookupInstanceMethod(CSelector) && 1025 !LookupMethodInQualifiedType(CSelector, OPT, true)) { 1026 // Must further look into private implementation methods. 1027 if (!LookupPrivateInstanceMethod(CSelector, IDecl)) 1028 Diag(ForLoc, diag::warn_collection_expr_type) 1029 << SecondType << CSelector << Second->getSourceRange(); 1030 } 1031 } 1032 } 1033 } 1034 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 1035 ForLoc, RParenLoc)); 1036} 1037 1038namespace { 1039 1040enum BeginEndFunction { 1041 BEF_begin, 1042 BEF_end 1043}; 1044 1045/// Build a variable declaration for a for-range statement. 1046static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1047 QualType Type, const char *Name) { 1048 DeclContext *DC = SemaRef.CurContext; 1049 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1050 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1051 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1052 TInfo, SC_Auto, SC_None); 1053 Decl->setImplicit(); 1054 return Decl; 1055} 1056 1057/// Finish building a variable declaration for a for-range statement. 1058/// \return true if an error occurs. 1059static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1060 SourceLocation Loc, int diag) { 1061 // Deduce the type for the iterator variable now rather than leaving it to 1062 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1063 TypeSourceInfo *InitTSI = 0; 1064 if (Init->getType()->isVoidType() || 1065 !SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI)) 1066 SemaRef.Diag(Loc, diag) << Init->getType(); 1067 if (!InitTSI) { 1068 Decl->setInvalidDecl(); 1069 return true; 1070 } 1071 Decl->setTypeSourceInfo(InitTSI); 1072 Decl->setType(InitTSI->getType()); 1073 1074 // In ARC, infer lifetime. 1075 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1076 // we're doing the equivalent of fast iteration. 1077 if (SemaRef.getLangOptions().ObjCAutoRefCount && 1078 SemaRef.inferObjCARCLifetime(Decl)) 1079 Decl->setInvalidDecl(); 1080 1081 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1082 /*TypeMayContainAuto=*/false); 1083 SemaRef.FinalizeDeclaration(Decl); 1084 SemaRef.CurContext->addHiddenDecl(Decl); 1085 return false; 1086} 1087 1088/// Produce a note indicating which begin/end function was implicitly called 1089/// by a C++0x for-range statement. This is often not obvious from the code, 1090/// nor from the diagnostics produced when analysing the implicit expressions 1091/// required in a for-range statement. 1092void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1093 BeginEndFunction BEF) { 1094 CallExpr *CE = dyn_cast<CallExpr>(E); 1095 if (!CE) 1096 return; 1097 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1098 if (!D) 1099 return; 1100 SourceLocation Loc = D->getLocation(); 1101 1102 std::string Description; 1103 bool IsTemplate = false; 1104 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1105 Description = SemaRef.getTemplateArgumentBindingsText( 1106 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1107 IsTemplate = true; 1108 } 1109 1110 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1111 << BEF << IsTemplate << Description << E->getType(); 1112} 1113 1114/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1115/// given LookupResult is non-empty, it is assumed to describe a member which 1116/// will be invoked. Otherwise, the function will be found via argument 1117/// dependent lookup. 1118static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1119 SourceLocation Loc, 1120 VarDecl *Decl, 1121 BeginEndFunction BEF, 1122 const DeclarationNameInfo &NameInfo, 1123 LookupResult &MemberLookup, 1124 Expr *Range) { 1125 ExprResult CallExpr; 1126 if (!MemberLookup.empty()) { 1127 ExprResult MemberRef = 1128 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1129 /*IsPtr=*/false, CXXScopeSpec(), 1130 /*Qualifier=*/0, MemberLookup, 1131 /*TemplateArgs=*/0); 1132 if (MemberRef.isInvalid()) 1133 return ExprError(); 1134 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1135 Loc, 0); 1136 if (CallExpr.isInvalid()) 1137 return ExprError(); 1138 } else { 1139 UnresolvedSet<0> FoundNames; 1140 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1141 // std is an associated namespace. 1142 UnresolvedLookupExpr *Fn = 1143 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1144 NestedNameSpecifierLoc(), NameInfo, 1145 /*NeedsADL=*/true, /*Overloaded=*/false, 1146 FoundNames.begin(), FoundNames.end(), 1147 /*LookInStdNamespace=*/true); 1148 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1149 0); 1150 if (CallExpr.isInvalid()) { 1151 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1152 << Range->getType(); 1153 return ExprError(); 1154 } 1155 } 1156 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1157 diag::err_for_range_iter_deduction_failure)) { 1158 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1159 return ExprError(); 1160 } 1161 return CallExpr; 1162} 1163 1164} 1165 1166/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1167/// 1168/// C++0x [stmt.ranged]: 1169/// A range-based for statement is equivalent to 1170/// 1171/// { 1172/// auto && __range = range-init; 1173/// for ( auto __begin = begin-expr, 1174/// __end = end-expr; 1175/// __begin != __end; 1176/// ++__begin ) { 1177/// for-range-declaration = *__begin; 1178/// statement 1179/// } 1180/// } 1181/// 1182/// The body of the loop is not available yet, since it cannot be analysed until 1183/// we have determined the type of the for-range-declaration. 1184StmtResult 1185Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1186 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1187 SourceLocation RParenLoc) { 1188 if (!First || !Range) 1189 return StmtError(); 1190 1191 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1192 assert(DS && "first part of for range not a decl stmt"); 1193 1194 if (!DS->isSingleDecl()) { 1195 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1196 return StmtError(); 1197 } 1198 if (DS->getSingleDecl()->isInvalidDecl()) 1199 return StmtError(); 1200 1201 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1202 return StmtError(); 1203 1204 // Build auto && __range = range-init 1205 SourceLocation RangeLoc = Range->getLocStart(); 1206 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1207 Context.getAutoRRefDeductType(), 1208 "__range"); 1209 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1210 diag::err_for_range_deduction_failure)) 1211 return StmtError(); 1212 1213 // Claim the type doesn't contain auto: we've already done the checking. 1214 DeclGroupPtrTy RangeGroup = 1215 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1216 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1217 if (RangeDecl.isInvalid()) 1218 return StmtError(); 1219 1220 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1221 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1222 RParenLoc); 1223} 1224 1225/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1226StmtResult 1227Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1228 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1229 Expr *Inc, Stmt *LoopVarDecl, 1230 SourceLocation RParenLoc) { 1231 Scope *S = getCurScope(); 1232 1233 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1234 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1235 QualType RangeVarType = RangeVar->getType(); 1236 1237 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1238 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1239 1240 StmtResult BeginEndDecl = BeginEnd; 1241 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1242 1243 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1244 SourceLocation RangeLoc = RangeVar->getLocation(); 1245 1246 ExprResult RangeRef = BuildDeclRefExpr(RangeVar, 1247 RangeVarType.getNonReferenceType(), 1248 VK_LValue, ColonLoc); 1249 if (RangeRef.isInvalid()) 1250 return StmtError(); 1251 1252 QualType AutoType = Context.getAutoDeductType(); 1253 Expr *Range = RangeVar->getInit(); 1254 if (!Range) 1255 return StmtError(); 1256 QualType RangeType = Range->getType(); 1257 1258 if (RequireCompleteType(RangeLoc, RangeType, 1259 PDiag(diag::err_for_range_incomplete_type))) 1260 return StmtError(); 1261 1262 // Build auto __begin = begin-expr, __end = end-expr. 1263 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1264 "__begin"); 1265 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1266 "__end"); 1267 1268 // Build begin-expr and end-expr and attach to __begin and __end variables. 1269 ExprResult BeginExpr, EndExpr; 1270 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1271 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1272 // __range + __bound, respectively, where __bound is the array bound. If 1273 // _RangeT is an array of unknown size or an array of incomplete type, 1274 // the program is ill-formed; 1275 1276 // begin-expr is __range. 1277 BeginExpr = RangeRef; 1278 if (FinishForRangeVarDecl(*this, BeginVar, RangeRef.get(), ColonLoc, 1279 diag::err_for_range_iter_deduction_failure)) { 1280 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1281 return StmtError(); 1282 } 1283 1284 // Find the array bound. 1285 ExprResult BoundExpr; 1286 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1287 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1288 Context.getPointerDiffType(), 1289 RangeLoc)); 1290 else if (const VariableArrayType *VAT = 1291 dyn_cast<VariableArrayType>(UnqAT)) 1292 BoundExpr = VAT->getSizeExpr(); 1293 else { 1294 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1295 // UnqAT is not incomplete and Range is not type-dependent. 1296 assert(0 && "Unexpected array type in for-range"); 1297 return StmtError(); 1298 } 1299 1300 // end-expr is __range + __bound. 1301 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, RangeRef.get(), 1302 BoundExpr.get()); 1303 if (EndExpr.isInvalid()) 1304 return StmtError(); 1305 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1306 diag::err_for_range_iter_deduction_failure)) { 1307 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1308 return StmtError(); 1309 } 1310 } else { 1311 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1312 ColonLoc); 1313 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1314 ColonLoc); 1315 1316 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1317 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1318 1319 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1320 // - if _RangeT is a class type, the unqualified-ids begin and end are 1321 // looked up in the scope of class _RangeT as if by class member access 1322 // lookup (3.4.5), and if either (or both) finds at least one 1323 // declaration, begin-expr and end-expr are __range.begin() and 1324 // __range.end(), respectively; 1325 LookupQualifiedName(BeginMemberLookup, D); 1326 LookupQualifiedName(EndMemberLookup, D); 1327 1328 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1329 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1330 << RangeType << BeginMemberLookup.empty(); 1331 return StmtError(); 1332 } 1333 } else { 1334 // - otherwise, begin-expr and end-expr are begin(__range) and 1335 // end(__range), respectively, where begin and end are looked up with 1336 // argument-dependent lookup (3.4.2). For the purposes of this name 1337 // lookup, namespace std is an associated namespace. 1338 } 1339 1340 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1341 BEF_begin, BeginNameInfo, 1342 BeginMemberLookup, RangeRef.get()); 1343 if (BeginExpr.isInvalid()) 1344 return StmtError(); 1345 1346 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1347 BEF_end, EndNameInfo, 1348 EndMemberLookup, RangeRef.get()); 1349 if (EndExpr.isInvalid()) 1350 return StmtError(); 1351 } 1352 1353 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1354 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1355 if (!Context.hasSameType(BeginType, EndType)) { 1356 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1357 << BeginType << EndType; 1358 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1359 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1360 } 1361 1362 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1363 // Claim the type doesn't contain auto: we've already done the checking. 1364 DeclGroupPtrTy BeginEndGroup = 1365 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1366 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1367 1368 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, 1369 BeginType.getNonReferenceType(), 1370 VK_LValue, ColonLoc); 1371 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1372 VK_LValue, ColonLoc); 1373 1374 // Build and check __begin != __end expression. 1375 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1376 BeginRef.get(), EndRef.get()); 1377 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1378 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1379 if (NotEqExpr.isInvalid()) { 1380 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1381 if (!Context.hasSameType(BeginType, EndType)) 1382 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1383 return StmtError(); 1384 } 1385 1386 // Build and check ++__begin expression. 1387 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1388 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1389 if (IncrExpr.isInvalid()) { 1390 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1391 return StmtError(); 1392 } 1393 1394 // Build and check *__begin expression. 1395 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1396 if (DerefExpr.isInvalid()) { 1397 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1398 return StmtError(); 1399 } 1400 1401 // Attach *__begin as initializer for VD. 1402 if (!LoopVar->isInvalidDecl()) { 1403 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1404 /*TypeMayContainAuto=*/true); 1405 if (LoopVar->isInvalidDecl()) 1406 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1407 } 1408 } 1409 1410 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1411 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1412 NotEqExpr.take(), IncrExpr.take(), 1413 LoopVarDS, /*Body=*/0, ForLoc, 1414 ColonLoc, RParenLoc)); 1415} 1416 1417/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1418/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1419/// body cannot be performed until after the type of the range variable is 1420/// determined. 1421StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1422 if (!S || !B) 1423 return StmtError(); 1424 1425 cast<CXXForRangeStmt>(S)->setBody(B); 1426 return S; 1427} 1428 1429StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1430 SourceLocation LabelLoc, 1431 LabelDecl *TheDecl) { 1432 getCurFunction()->setHasBranchIntoScope(); 1433 TheDecl->setUsed(); 1434 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1435} 1436 1437StmtResult 1438Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1439 Expr *E) { 1440 // Convert operand to void* 1441 if (!E->isTypeDependent()) { 1442 QualType ETy = E->getType(); 1443 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1444 ExprResult ExprRes = Owned(E); 1445 AssignConvertType ConvTy = 1446 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1447 if (ExprRes.isInvalid()) 1448 return StmtError(); 1449 E = ExprRes.take(); 1450 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1451 return StmtError(); 1452 } 1453 1454 getCurFunction()->setHasIndirectGoto(); 1455 1456 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1457} 1458 1459StmtResult 1460Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1461 Scope *S = CurScope->getContinueParent(); 1462 if (!S) { 1463 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1464 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1465 } 1466 1467 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1468} 1469 1470StmtResult 1471Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1472 Scope *S = CurScope->getBreakParent(); 1473 if (!S) { 1474 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1475 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1476 } 1477 1478 return Owned(new (Context) BreakStmt(BreakLoc)); 1479} 1480 1481/// \brief Determine whether the given expression is a candidate for 1482/// copy elision in either a return statement or a throw expression. 1483/// 1484/// \param ReturnType If we're determining the copy elision candidate for 1485/// a return statement, this is the return type of the function. If we're 1486/// determining the copy elision candidate for a throw expression, this will 1487/// be a NULL type. 1488/// 1489/// \param E The expression being returned from the function or block, or 1490/// being thrown. 1491/// 1492/// \param AllowFunctionParameter Whether we allow function parameters to 1493/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1494/// we re-use this logic to determine whether we should try to move as part of 1495/// a return or throw (which does allow function parameters). 1496/// 1497/// \returns The NRVO candidate variable, if the return statement may use the 1498/// NRVO, or NULL if there is no such candidate. 1499const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1500 Expr *E, 1501 bool AllowFunctionParameter) { 1502 QualType ExprType = E->getType(); 1503 // - in a return statement in a function with ... 1504 // ... a class return type ... 1505 if (!ReturnType.isNull()) { 1506 if (!ReturnType->isRecordType()) 1507 return 0; 1508 // ... the same cv-unqualified type as the function return type ... 1509 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1510 return 0; 1511 } 1512 1513 // ... the expression is the name of a non-volatile automatic object 1514 // (other than a function or catch-clause parameter)) ... 1515 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1516 if (!DR) 1517 return 0; 1518 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1519 if (!VD) 1520 return 0; 1521 1522 if (VD->hasLocalStorage() && !VD->isExceptionVariable() && 1523 !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() && 1524 !VD->getType().isVolatileQualified() && 1525 ((VD->getKind() == Decl::Var) || 1526 (AllowFunctionParameter && VD->getKind() == Decl::ParmVar))) 1527 return VD; 1528 1529 return 0; 1530} 1531 1532/// \brief Perform the initialization of a potentially-movable value, which 1533/// is the result of return value. 1534/// 1535/// This routine implements C++0x [class.copy]p33, which attempts to treat 1536/// returned lvalues as rvalues in certain cases (to prefer move construction), 1537/// then falls back to treating them as lvalues if that failed. 1538ExprResult 1539Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1540 const VarDecl *NRVOCandidate, 1541 QualType ResultType, 1542 Expr *Value) { 1543 // C++0x [class.copy]p33: 1544 // When the criteria for elision of a copy operation are met or would 1545 // be met save for the fact that the source object is a function 1546 // parameter, and the object to be copied is designated by an lvalue, 1547 // overload resolution to select the constructor for the copy is first 1548 // performed as if the object were designated by an rvalue. 1549 ExprResult Res = ExprError(); 1550 if (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true)) { 1551 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1552 Value->getType(), CK_LValueToRValue, 1553 Value, VK_XValue); 1554 1555 Expr *InitExpr = &AsRvalue; 1556 InitializationKind Kind 1557 = InitializationKind::CreateCopy(Value->getLocStart(), 1558 Value->getLocStart()); 1559 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 1560 1561 // [...] If overload resolution fails, or if the type of the first 1562 // parameter of the selected constructor is not an rvalue reference 1563 // to the object's type (possibly cv-qualified), overload resolution 1564 // is performed again, considering the object as an lvalue. 1565 if (Seq) { 1566 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 1567 StepEnd = Seq.step_end(); 1568 Step != StepEnd; ++Step) { 1569 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 1570 continue; 1571 1572 CXXConstructorDecl *Constructor 1573 = cast<CXXConstructorDecl>(Step->Function.Function); 1574 1575 const RValueReferenceType *RRefType 1576 = Constructor->getParamDecl(0)->getType() 1577 ->getAs<RValueReferenceType>(); 1578 1579 // If we don't meet the criteria, break out now. 1580 if (!RRefType || 1581 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 1582 Context.getTypeDeclType(Constructor->getParent()))) 1583 break; 1584 1585 // Promote "AsRvalue" to the heap, since we now need this 1586 // expression node to persist. 1587 Value = ImplicitCastExpr::Create(Context, Value->getType(), 1588 CK_LValueToRValue, Value, 0, 1589 VK_XValue); 1590 1591 // Complete type-checking the initialization of the return type 1592 // using the constructor we found. 1593 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 1594 } 1595 } 1596 } 1597 1598 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 1599 // above, or overload resolution failed. Either way, we need to try 1600 // (again) now with the return value expression as written. 1601 if (Res.isInvalid()) 1602 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 1603 1604 return Res; 1605} 1606 1607/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 1608/// 1609StmtResult 1610Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1611 // If this is the first return we've seen in the block, infer the type of 1612 // the block from it. 1613 BlockScopeInfo *CurBlock = getCurBlock(); 1614 if (CurBlock->ReturnType.isNull()) { 1615 if (RetValExp) { 1616 // Don't call UsualUnaryConversions(), since we don't want to do 1617 // integer promotions here. 1618 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 1619 if (Result.isInvalid()) 1620 return StmtError(); 1621 RetValExp = Result.take(); 1622 1623 if (!RetValExp->isTypeDependent()) { 1624 CurBlock->ReturnType = RetValExp->getType(); 1625 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) { 1626 // We have to remove a 'const' added to copied-in variable which was 1627 // part of the implementation spec. and not the actual qualifier for 1628 // the variable. 1629 if (CDRE->isConstQualAdded()) 1630 CurBlock->ReturnType.removeLocalConst(); // FIXME: local??? 1631 } 1632 } else 1633 CurBlock->ReturnType = Context.DependentTy; 1634 } else 1635 CurBlock->ReturnType = Context.VoidTy; 1636 } 1637 QualType FnRetType = CurBlock->ReturnType; 1638 1639 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 1640 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 1641 << getCurFunctionOrMethodDecl()->getDeclName(); 1642 return StmtError(); 1643 } 1644 1645 // Otherwise, verify that this result type matches the previous one. We are 1646 // pickier with blocks than for normal functions because we don't have GCC 1647 // compatibility to worry about here. 1648 ReturnStmt *Result = 0; 1649 if (CurBlock->ReturnType->isVoidType()) { 1650 if (RetValExp && !RetValExp->isTypeDependent() && 1651 (!getLangOptions().CPlusPlus || !RetValExp->getType()->isVoidType())) { 1652 Diag(ReturnLoc, diag::err_return_block_has_expr); 1653 RetValExp = 0; 1654 } 1655 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1656 } else if (!RetValExp) { 1657 if (!CurBlock->ReturnType->isDependentType()) 1658 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 1659 1660 Result = new (Context) ReturnStmt(ReturnLoc, 0, 0); 1661 } else { 1662 const VarDecl *NRVOCandidate = 0; 1663 1664 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1665 // we have a non-void block with an expression, continue checking 1666 1667 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1668 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1669 // function return. 1670 1671 // In C++ the return statement is handled via a copy initialization. 1672 // the C version of which boils down to CheckSingleAssignmentConstraints. 1673 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1674 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1675 FnRetType, 1676 NRVOCandidate != 0); 1677 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1678 FnRetType, RetValExp); 1679 if (Res.isInvalid()) { 1680 // FIXME: Cleanup temporaries here, anyway? 1681 return StmtError(); 1682 } 1683 1684 if (RetValExp) { 1685 CheckImplicitConversions(RetValExp, ReturnLoc); 1686 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1687 } 1688 1689 RetValExp = Res.takeAs<Expr>(); 1690 if (RetValExp) 1691 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1692 } 1693 1694 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1695 } 1696 1697 // If we need to check for the named return value optimization, save the 1698 // return statement in our scope for later processing. 1699 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1700 !CurContext->isDependentContext()) 1701 FunctionScopes.back()->Returns.push_back(Result); 1702 1703 return Owned(Result); 1704} 1705 1706StmtResult 1707Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1708 // Check for unexpanded parameter packs. 1709 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 1710 return StmtError(); 1711 1712 if (getCurBlock()) 1713 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 1714 1715 QualType FnRetType; 1716 QualType DeclaredRetType; 1717 if (const FunctionDecl *FD = getCurFunctionDecl()) { 1718 FnRetType = FD->getResultType(); 1719 DeclaredRetType = FnRetType; 1720 if (FD->hasAttr<NoReturnAttr>() || 1721 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 1722 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 1723 << getCurFunctionOrMethodDecl()->getDeclName(); 1724 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 1725 DeclaredRetType = MD->getResultType(); 1726 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 1727 // In the implementation of a method with a related return type, the 1728 // type used to type-check the validity of return statements within the 1729 // method body is a pointer to the type of the class being implemented. 1730 FnRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 1731 FnRetType = Context.getObjCObjectPointerType(FnRetType); 1732 } else { 1733 FnRetType = DeclaredRetType; 1734 } 1735 } else // If we don't have a function/method context, bail. 1736 return StmtError(); 1737 1738 ReturnStmt *Result = 0; 1739 if (FnRetType->isVoidType()) { 1740 if (RetValExp) { 1741 if (!RetValExp->isTypeDependent()) { 1742 // C99 6.8.6.4p1 (ext_ since GCC warns) 1743 unsigned D = diag::ext_return_has_expr; 1744 if (RetValExp->getType()->isVoidType()) 1745 D = diag::ext_return_has_void_expr; 1746 else { 1747 ExprResult Result = Owned(RetValExp); 1748 Result = IgnoredValueConversions(Result.take()); 1749 if (Result.isInvalid()) 1750 return StmtError(); 1751 RetValExp = Result.take(); 1752 RetValExp = ImpCastExprToType(RetValExp, 1753 Context.VoidTy, CK_ToVoid).take(); 1754 } 1755 1756 // return (some void expression); is legal in C++. 1757 if (D != diag::ext_return_has_void_expr || 1758 !getLangOptions().CPlusPlus) { 1759 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 1760 Diag(ReturnLoc, D) 1761 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 1762 << RetValExp->getSourceRange(); 1763 } 1764 } 1765 1766 CheckImplicitConversions(RetValExp, ReturnLoc); 1767 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1768 } 1769 1770 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1771 } else if (!RetValExp && !FnRetType->isDependentType()) { 1772 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 1773 // C99 6.8.6.4p1 (ext_ since GCC warns) 1774 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 1775 1776 if (FunctionDecl *FD = getCurFunctionDecl()) 1777 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 1778 else 1779 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 1780 Result = new (Context) ReturnStmt(ReturnLoc); 1781 } else { 1782 const VarDecl *NRVOCandidate = 0; 1783 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1784 // we have a non-void function with an expression, continue checking 1785 1786 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1787 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1788 // function return. 1789 1790 // In C++ the return statement is handled via a copy initialization, 1791 // the C version of which boils down to CheckSingleAssignmentConstraints. 1792 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1793 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1794 FnRetType, 1795 NRVOCandidate != 0); 1796 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1797 FnRetType, RetValExp); 1798 if (Res.isInvalid()) { 1799 // FIXME: Cleanup temporaries here, anyway? 1800 return StmtError(); 1801 } 1802 1803 RetValExp = Res.takeAs<Expr>(); 1804 if (RetValExp) 1805 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1806 } 1807 1808 if (RetValExp) { 1809 // If we type-checked an Objective-C method's return type based 1810 // on a related return type, we may need to adjust the return 1811 // type again. Do so now. 1812 if (DeclaredRetType != FnRetType) { 1813 ExprResult result = PerformImplicitConversion(RetValExp, 1814 DeclaredRetType, 1815 AA_Returning); 1816 if (result.isInvalid()) return StmtError(); 1817 RetValExp = result.take(); 1818 } 1819 1820 CheckImplicitConversions(RetValExp, ReturnLoc); 1821 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1822 } 1823 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1824 } 1825 1826 // If we need to check for the named return value optimization, save the 1827 // return statement in our scope for later processing. 1828 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1829 !CurContext->isDependentContext()) 1830 FunctionScopes.back()->Returns.push_back(Result); 1831 1832 return Owned(Result); 1833} 1834 1835/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 1836/// ignore "noop" casts in places where an lvalue is required by an inline asm. 1837/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 1838/// provide a strong guidance to not use it. 1839/// 1840/// This method checks to see if the argument is an acceptable l-value and 1841/// returns false if it is a case we can handle. 1842static bool CheckAsmLValue(const Expr *E, Sema &S) { 1843 // Type dependent expressions will be checked during instantiation. 1844 if (E->isTypeDependent()) 1845 return false; 1846 1847 if (E->isLValue()) 1848 return false; // Cool, this is an lvalue. 1849 1850 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 1851 // are supposed to allow. 1852 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 1853 if (E != E2 && E2->isLValue()) { 1854 if (!S.getLangOptions().HeinousExtensions) 1855 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 1856 << E->getSourceRange(); 1857 else 1858 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 1859 << E->getSourceRange(); 1860 // Accept, even if we emitted an error diagnostic. 1861 return false; 1862 } 1863 1864 // None of the above, just randomly invalid non-lvalue. 1865 return true; 1866} 1867 1868/// isOperandMentioned - Return true if the specified operand # is mentioned 1869/// anywhere in the decomposed asm string. 1870static bool isOperandMentioned(unsigned OpNo, 1871 llvm::ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 1872 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 1873 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 1874 if (!Piece.isOperand()) continue; 1875 1876 // If this is a reference to the input and if the input was the smaller 1877 // one, then we have to reject this asm. 1878 if (Piece.getOperandNo() == OpNo) 1879 return true; 1880 } 1881 1882 return false; 1883} 1884 1885StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 1886 bool IsVolatile, unsigned NumOutputs, 1887 unsigned NumInputs, IdentifierInfo **Names, 1888 MultiExprArg constraints, MultiExprArg exprs, 1889 Expr *asmString, MultiExprArg clobbers, 1890 SourceLocation RParenLoc, bool MSAsm) { 1891 unsigned NumClobbers = clobbers.size(); 1892 StringLiteral **Constraints = 1893 reinterpret_cast<StringLiteral**>(constraints.get()); 1894 Expr **Exprs = exprs.get(); 1895 StringLiteral *AsmString = cast<StringLiteral>(asmString); 1896 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 1897 1898 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 1899 1900 // The parser verifies that there is a string literal here. 1901 if (AsmString->isWide()) 1902 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 1903 << AsmString->getSourceRange()); 1904 1905 for (unsigned i = 0; i != NumOutputs; i++) { 1906 StringLiteral *Literal = Constraints[i]; 1907 if (Literal->isWide()) 1908 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1909 << Literal->getSourceRange()); 1910 1911 llvm::StringRef OutputName; 1912 if (Names[i]) 1913 OutputName = Names[i]->getName(); 1914 1915 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 1916 if (!Context.Target.validateOutputConstraint(Info)) 1917 return StmtError(Diag(Literal->getLocStart(), 1918 diag::err_asm_invalid_output_constraint) 1919 << Info.getConstraintStr()); 1920 1921 // Check that the output exprs are valid lvalues. 1922 Expr *OutputExpr = Exprs[i]; 1923 if (CheckAsmLValue(OutputExpr, *this)) { 1924 return StmtError(Diag(OutputExpr->getLocStart(), 1925 diag::err_asm_invalid_lvalue_in_output) 1926 << OutputExpr->getSourceRange()); 1927 } 1928 1929 OutputConstraintInfos.push_back(Info); 1930 } 1931 1932 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 1933 1934 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 1935 StringLiteral *Literal = Constraints[i]; 1936 if (Literal->isWide()) 1937 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1938 << Literal->getSourceRange()); 1939 1940 llvm::StringRef InputName; 1941 if (Names[i]) 1942 InputName = Names[i]->getName(); 1943 1944 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 1945 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(), 1946 NumOutputs, Info)) { 1947 return StmtError(Diag(Literal->getLocStart(), 1948 diag::err_asm_invalid_input_constraint) 1949 << Info.getConstraintStr()); 1950 } 1951 1952 Expr *InputExpr = Exprs[i]; 1953 1954 // Only allow void types for memory constraints. 1955 if (Info.allowsMemory() && !Info.allowsRegister()) { 1956 if (CheckAsmLValue(InputExpr, *this)) 1957 return StmtError(Diag(InputExpr->getLocStart(), 1958 diag::err_asm_invalid_lvalue_in_input) 1959 << Info.getConstraintStr() 1960 << InputExpr->getSourceRange()); 1961 } 1962 1963 if (Info.allowsRegister()) { 1964 if (InputExpr->getType()->isVoidType()) { 1965 return StmtError(Diag(InputExpr->getLocStart(), 1966 diag::err_asm_invalid_type_in_input) 1967 << InputExpr->getType() << Info.getConstraintStr() 1968 << InputExpr->getSourceRange()); 1969 } 1970 } 1971 1972 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 1973 if (Result.isInvalid()) 1974 return StmtError(); 1975 1976 Exprs[i] = Result.take(); 1977 InputConstraintInfos.push_back(Info); 1978 } 1979 1980 // Check that the clobbers are valid. 1981 for (unsigned i = 0; i != NumClobbers; i++) { 1982 StringLiteral *Literal = Clobbers[i]; 1983 if (Literal->isWide()) 1984 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1985 << Literal->getSourceRange()); 1986 1987 llvm::StringRef Clobber = Literal->getString(); 1988 1989 if (!Context.Target.isValidGCCRegisterName(Clobber)) 1990 return StmtError(Diag(Literal->getLocStart(), 1991 diag::err_asm_unknown_register_name) << Clobber); 1992 } 1993 1994 AsmStmt *NS = 1995 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 1996 NumOutputs, NumInputs, Names, Constraints, Exprs, 1997 AsmString, NumClobbers, Clobbers, RParenLoc); 1998 // Validate the asm string, ensuring it makes sense given the operands we 1999 // have. 2000 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2001 unsigned DiagOffs; 2002 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2003 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2004 << AsmString->getSourceRange(); 2005 return StmtError(); 2006 } 2007 2008 // Validate tied input operands for type mismatches. 2009 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2010 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2011 2012 // If this is a tied constraint, verify that the output and input have 2013 // either exactly the same type, or that they are int/ptr operands with the 2014 // same size (int/long, int*/long, are ok etc). 2015 if (!Info.hasTiedOperand()) continue; 2016 2017 unsigned TiedTo = Info.getTiedOperand(); 2018 unsigned InputOpNo = i+NumOutputs; 2019 Expr *OutputExpr = Exprs[TiedTo]; 2020 Expr *InputExpr = Exprs[InputOpNo]; 2021 QualType InTy = InputExpr->getType(); 2022 QualType OutTy = OutputExpr->getType(); 2023 if (Context.hasSameType(InTy, OutTy)) 2024 continue; // All types can be tied to themselves. 2025 2026 // Decide if the input and output are in the same domain (integer/ptr or 2027 // floating point. 2028 enum AsmDomain { 2029 AD_Int, AD_FP, AD_Other 2030 } InputDomain, OutputDomain; 2031 2032 if (InTy->isIntegerType() || InTy->isPointerType()) 2033 InputDomain = AD_Int; 2034 else if (InTy->isRealFloatingType()) 2035 InputDomain = AD_FP; 2036 else 2037 InputDomain = AD_Other; 2038 2039 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2040 OutputDomain = AD_Int; 2041 else if (OutTy->isRealFloatingType()) 2042 OutputDomain = AD_FP; 2043 else 2044 OutputDomain = AD_Other; 2045 2046 // They are ok if they are the same size and in the same domain. This 2047 // allows tying things like: 2048 // void* to int* 2049 // void* to int if they are the same size. 2050 // double to long double if they are the same size. 2051 // 2052 uint64_t OutSize = Context.getTypeSize(OutTy); 2053 uint64_t InSize = Context.getTypeSize(InTy); 2054 if (OutSize == InSize && InputDomain == OutputDomain && 2055 InputDomain != AD_Other) 2056 continue; 2057 2058 // If the smaller input/output operand is not mentioned in the asm string, 2059 // then we can promote the smaller one to a larger input and the asm string 2060 // won't notice. 2061 bool SmallerValueMentioned = false; 2062 2063 // If this is a reference to the input and if the input was the smaller 2064 // one, then we have to reject this asm. 2065 if (isOperandMentioned(InputOpNo, Pieces)) { 2066 // This is a use in the asm string of the smaller operand. Since we 2067 // codegen this by promoting to a wider value, the asm will get printed 2068 // "wrong". 2069 SmallerValueMentioned |= InSize < OutSize; 2070 } 2071 if (isOperandMentioned(TiedTo, Pieces)) { 2072 // If this is a reference to the output, and if the output is the larger 2073 // value, then it's ok because we'll promote the input to the larger type. 2074 SmallerValueMentioned |= OutSize < InSize; 2075 } 2076 2077 // If the smaller value wasn't mentioned in the asm string, and if the 2078 // output was a register, just extend the shorter one to the size of the 2079 // larger one. 2080 if (!SmallerValueMentioned && InputDomain != AD_Other && 2081 OutputConstraintInfos[TiedTo].allowsRegister()) 2082 continue; 2083 2084 // Either both of the operands were mentioned or the smaller one was 2085 // mentioned. One more special case that we'll allow: if the tied input is 2086 // integer, unmentioned, and is a constant, then we'll allow truncating it 2087 // down to the size of the destination. 2088 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2089 !isOperandMentioned(InputOpNo, Pieces) && 2090 InputExpr->isEvaluatable(Context)) { 2091 CastKind castKind = 2092 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2093 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2094 Exprs[InputOpNo] = InputExpr; 2095 NS->setInputExpr(i, InputExpr); 2096 continue; 2097 } 2098 2099 Diag(InputExpr->getLocStart(), 2100 diag::err_asm_tying_incompatible_types) 2101 << InTy << OutTy << OutputExpr->getSourceRange() 2102 << InputExpr->getSourceRange(); 2103 return StmtError(); 2104 } 2105 2106 return Owned(NS); 2107} 2108 2109StmtResult 2110Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2111 SourceLocation RParen, Decl *Parm, 2112 Stmt *Body) { 2113 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2114 if (Var && Var->isInvalidDecl()) 2115 return StmtError(); 2116 2117 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2118} 2119 2120StmtResult 2121Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2122 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2123} 2124 2125StmtResult 2126Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2127 MultiStmtArg CatchStmts, Stmt *Finally) { 2128 if (!getLangOptions().ObjCExceptions) 2129 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2130 2131 getCurFunction()->setHasBranchProtectedScope(); 2132 unsigned NumCatchStmts = CatchStmts.size(); 2133 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2134 CatchStmts.release(), 2135 NumCatchStmts, 2136 Finally)); 2137} 2138 2139StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2140 Expr *Throw) { 2141 if (Throw) { 2142 ExprResult Result = DefaultLvalueConversion(Throw); 2143 if (Result.isInvalid()) 2144 return StmtError(); 2145 2146 Throw = Result.take(); 2147 QualType ThrowType = Throw->getType(); 2148 // Make sure the expression type is an ObjC pointer or "void *". 2149 if (!ThrowType->isDependentType() && 2150 !ThrowType->isObjCObjectPointerType()) { 2151 const PointerType *PT = ThrowType->getAs<PointerType>(); 2152 if (!PT || !PT->getPointeeType()->isVoidType()) 2153 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2154 << Throw->getType() << Throw->getSourceRange()); 2155 } 2156 } 2157 2158 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2159} 2160 2161StmtResult 2162Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2163 Scope *CurScope) { 2164 if (!getLangOptions().ObjCExceptions) 2165 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2166 2167 if (!Throw) { 2168 // @throw without an expression designates a rethrow (which much occur 2169 // in the context of an @catch clause). 2170 Scope *AtCatchParent = CurScope; 2171 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2172 AtCatchParent = AtCatchParent->getParent(); 2173 if (!AtCatchParent) 2174 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2175 } 2176 2177 return BuildObjCAtThrowStmt(AtLoc, Throw); 2178} 2179 2180StmtResult 2181Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2182 Stmt *SyncBody) { 2183 getCurFunction()->setHasBranchProtectedScope(); 2184 2185 ExprResult Result = DefaultLvalueConversion(SyncExpr); 2186 if (Result.isInvalid()) 2187 return StmtError(); 2188 2189 SyncExpr = Result.take(); 2190 // Make sure the expression type is an ObjC pointer or "void *". 2191 if (!SyncExpr->getType()->isDependentType() && 2192 !SyncExpr->getType()->isObjCObjectPointerType()) { 2193 const PointerType *PT = SyncExpr->getType()->getAs<PointerType>(); 2194 if (!PT || !PT->getPointeeType()->isVoidType()) 2195 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 2196 << SyncExpr->getType() << SyncExpr->getSourceRange()); 2197 } 2198 2199 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2200} 2201 2202/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2203/// and creates a proper catch handler from them. 2204StmtResult 2205Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2206 Stmt *HandlerBlock) { 2207 // There's nothing to test that ActOnExceptionDecl didn't already test. 2208 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2209 cast_or_null<VarDecl>(ExDecl), 2210 HandlerBlock)); 2211} 2212 2213StmtResult 2214Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2215 getCurFunction()->setHasBranchProtectedScope(); 2216 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2217} 2218 2219namespace { 2220 2221class TypeWithHandler { 2222 QualType t; 2223 CXXCatchStmt *stmt; 2224public: 2225 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2226 : t(type), stmt(statement) {} 2227 2228 // An arbitrary order is fine as long as it places identical 2229 // types next to each other. 2230 bool operator<(const TypeWithHandler &y) const { 2231 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2232 return true; 2233 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2234 return false; 2235 else 2236 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2237 } 2238 2239 bool operator==(const TypeWithHandler& other) const { 2240 return t == other.t; 2241 } 2242 2243 CXXCatchStmt *getCatchStmt() const { return stmt; } 2244 SourceLocation getTypeSpecStartLoc() const { 2245 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2246 } 2247}; 2248 2249} 2250 2251/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2252/// handlers and creates a try statement from them. 2253StmtResult 2254Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2255 MultiStmtArg RawHandlers) { 2256 // Don't report an error if 'try' is used in system headers. 2257 if (!getLangOptions().CXXExceptions && 2258 !getSourceManager().isInSystemHeader(TryLoc)) 2259 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2260 2261 unsigned NumHandlers = RawHandlers.size(); 2262 assert(NumHandlers > 0 && 2263 "The parser shouldn't call this if there are no handlers."); 2264 Stmt **Handlers = RawHandlers.get(); 2265 2266 llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2267 2268 for (unsigned i = 0; i < NumHandlers; ++i) { 2269 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 2270 if (!Handler->getExceptionDecl()) { 2271 if (i < NumHandlers - 1) 2272 return StmtError(Diag(Handler->getLocStart(), 2273 diag::err_early_catch_all)); 2274 2275 continue; 2276 } 2277 2278 const QualType CaughtType = Handler->getCaughtType(); 2279 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2280 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2281 } 2282 2283 // Detect handlers for the same type as an earlier one. 2284 if (NumHandlers > 1) { 2285 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2286 2287 TypeWithHandler prev = TypesWithHandlers[0]; 2288 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2289 TypeWithHandler curr = TypesWithHandlers[i]; 2290 2291 if (curr == prev) { 2292 Diag(curr.getTypeSpecStartLoc(), 2293 diag::warn_exception_caught_by_earlier_handler) 2294 << curr.getCatchStmt()->getCaughtType().getAsString(); 2295 Diag(prev.getTypeSpecStartLoc(), 2296 diag::note_previous_exception_handler) 2297 << prev.getCatchStmt()->getCaughtType().getAsString(); 2298 } 2299 2300 prev = curr; 2301 } 2302 } 2303 2304 getCurFunction()->setHasBranchProtectedScope(); 2305 2306 // FIXME: We should detect handlers that cannot catch anything because an 2307 // earlier handler catches a superclass. Need to find a method that is not 2308 // quadratic for this. 2309 // Neither of these are explicitly forbidden, but every compiler detects them 2310 // and warns. 2311 2312 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2313 Handlers, NumHandlers)); 2314} 2315 2316StmtResult 2317Sema::ActOnSEHTryBlock(bool IsCXXTry, 2318 SourceLocation TryLoc, 2319 Stmt *TryBlock, 2320 Stmt *Handler) { 2321 assert(TryBlock && Handler); 2322 2323 getCurFunction()->setHasBranchProtectedScope(); 2324 2325 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2326} 2327 2328StmtResult 2329Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2330 Expr *FilterExpr, 2331 Stmt *Block) { 2332 assert(FilterExpr && Block); 2333 2334 if(!FilterExpr->getType()->isIntegerType()) { 2335 return StmtError(Diag(FilterExpr->getExprLoc(), 2336 diag::err_filter_expression_integral) 2337 << FilterExpr->getType()); 2338 } 2339 2340 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2341} 2342 2343StmtResult 2344Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2345 Stmt *Block) { 2346 assert(Block); 2347 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2348} 2349 2350