SemaStmt.cpp revision 223017
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 // suppress any potential 'unused variable' warning. 70 DG.getSingleDecl()->setUsed(); 71} 72 73void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 74 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 75 return DiagnoseUnusedExprResult(Label->getSubStmt()); 76 77 const Expr *E = dyn_cast_or_null<Expr>(S); 78 if (!E) 79 return; 80 81 SourceLocation Loc; 82 SourceRange R1, R2; 83 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context)) 84 return; 85 86 // Okay, we have an unused result. Depending on what the base expression is, 87 // we might want to make a more specific diagnostic. Check for one of these 88 // cases now. 89 unsigned DiagID = diag::warn_unused_expr; 90 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 91 E = Temps->getSubExpr(); 92 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 93 E = TempExpr->getSubExpr(); 94 95 E = E->IgnoreParenImpCasts(); 96 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 97 if (E->getType()->isVoidType()) 98 return; 99 100 // If the callee has attribute pure, const, or warn_unused_result, warn with 101 // a more specific message to make it clear what is happening. 102 if (const Decl *FD = CE->getCalleeDecl()) { 103 if (FD->getAttr<WarnUnusedResultAttr>()) { 104 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result"; 105 return; 106 } 107 if (FD->getAttr<PureAttr>()) { 108 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 109 return; 110 } 111 if (FD->getAttr<ConstAttr>()) { 112 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 113 return; 114 } 115 } 116 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 117 const ObjCMethodDecl *MD = ME->getMethodDecl(); 118 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 119 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result"; 120 return; 121 } 122 } else if (isa<ObjCPropertyRefExpr>(E)) { 123 DiagID = diag::warn_unused_property_expr; 124 } else if (const CXXFunctionalCastExpr *FC 125 = dyn_cast<CXXFunctionalCastExpr>(E)) { 126 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 127 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 128 return; 129 } 130 // Diagnose "(void*) blah" as a typo for "(void) blah". 131 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 132 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 133 QualType T = TI->getType(); 134 135 // We really do want to use the non-canonical type here. 136 if (T == Context.VoidPtrTy) { 137 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 138 139 Diag(Loc, diag::warn_unused_voidptr) 140 << FixItHint::CreateRemoval(TL.getStarLoc()); 141 return; 142 } 143 } 144 145 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 146} 147 148StmtResult 149Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 150 MultiStmtArg elts, bool isStmtExpr) { 151 unsigned NumElts = elts.size(); 152 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 153 // If we're in C89 mode, check that we don't have any decls after stmts. If 154 // so, emit an extension diagnostic. 155 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 156 // Note that __extension__ can be around a decl. 157 unsigned i = 0; 158 // Skip over all declarations. 159 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 160 /*empty*/; 161 162 // We found the end of the list or a statement. Scan for another declstmt. 163 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 164 /*empty*/; 165 166 if (i != NumElts) { 167 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 168 Diag(D->getLocation(), diag::ext_mixed_decls_code); 169 } 170 } 171 // Warn about unused expressions in statements. 172 for (unsigned i = 0; i != NumElts; ++i) { 173 // Ignore statements that are last in a statement expression. 174 if (isStmtExpr && i == NumElts - 1) 175 continue; 176 177 DiagnoseUnusedExprResult(Elts[i]); 178 } 179 180 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 181} 182 183StmtResult 184Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 185 SourceLocation DotDotDotLoc, Expr *RHSVal, 186 SourceLocation ColonLoc) { 187 assert((LHSVal != 0) && "missing expression in case statement"); 188 189 // C99 6.8.4.2p3: The expression shall be an integer constant. 190 // However, GCC allows any evaluatable integer expression. 191 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && 192 VerifyIntegerConstantExpression(LHSVal)) 193 return StmtError(); 194 195 // GCC extension: The expression shall be an integer constant. 196 197 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && 198 VerifyIntegerConstantExpression(RHSVal)) { 199 RHSVal = 0; // Recover by just forgetting about it. 200 } 201 202 if (getCurFunction()->SwitchStack.empty()) { 203 Diag(CaseLoc, diag::err_case_not_in_switch); 204 return StmtError(); 205 } 206 207 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 208 ColonLoc); 209 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 210 return Owned(CS); 211} 212 213/// ActOnCaseStmtBody - This installs a statement as the body of a case. 214void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 215 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 216 CS->setSubStmt(SubStmt); 217} 218 219StmtResult 220Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 221 Stmt *SubStmt, Scope *CurScope) { 222 if (getCurFunction()->SwitchStack.empty()) { 223 Diag(DefaultLoc, diag::err_default_not_in_switch); 224 return Owned(SubStmt); 225 } 226 227 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 228 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 229 return Owned(DS); 230} 231 232StmtResult 233Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 234 SourceLocation ColonLoc, Stmt *SubStmt) { 235 236 // If the label was multiply defined, reject it now. 237 if (TheDecl->getStmt()) { 238 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 239 Diag(TheDecl->getLocation(), diag::note_previous_definition); 240 return Owned(SubStmt); 241 } 242 243 // Otherwise, things are good. Fill in the declaration and return it. 244 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 245 TheDecl->setStmt(LS); 246 if (!TheDecl->isGnuLocal()) 247 TheDecl->setLocation(IdentLoc); 248 return Owned(LS); 249} 250 251StmtResult 252Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 253 Stmt *thenStmt, SourceLocation ElseLoc, 254 Stmt *elseStmt) { 255 ExprResult CondResult(CondVal.release()); 256 257 VarDecl *ConditionVar = 0; 258 if (CondVar) { 259 ConditionVar = cast<VarDecl>(CondVar); 260 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 261 if (CondResult.isInvalid()) 262 return StmtError(); 263 } 264 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 265 if (!ConditionExpr) 266 return StmtError(); 267 268 DiagnoseUnusedExprResult(thenStmt); 269 270 // Warn if the if block has a null body without an else value. 271 // this helps prevent bugs due to typos, such as 272 // if (condition); 273 // do_stuff(); 274 // 275 if (!elseStmt) { 276 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 277 // But do not warn if the body is a macro that expands to nothing, e.g: 278 // 279 // #define CALL(x) 280 // if (condition) 281 // CALL(0); 282 // 283 if (!stmt->hasLeadingEmptyMacro()) 284 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 285 } 286 287 DiagnoseUnusedExprResult(elseStmt); 288 289 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 290 thenStmt, ElseLoc, elseStmt)); 291} 292 293/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 294/// the specified width and sign. If an overflow occurs, detect it and emit 295/// the specified diagnostic. 296void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 297 unsigned NewWidth, bool NewSign, 298 SourceLocation Loc, 299 unsigned DiagID) { 300 // Perform a conversion to the promoted condition type if needed. 301 if (NewWidth > Val.getBitWidth()) { 302 // If this is an extension, just do it. 303 Val = Val.extend(NewWidth); 304 Val.setIsSigned(NewSign); 305 306 // If the input was signed and negative and the output is 307 // unsigned, don't bother to warn: this is implementation-defined 308 // behavior. 309 // FIXME: Introduce a second, default-ignored warning for this case? 310 } else if (NewWidth < Val.getBitWidth()) { 311 // If this is a truncation, check for overflow. 312 llvm::APSInt ConvVal(Val); 313 ConvVal = ConvVal.trunc(NewWidth); 314 ConvVal.setIsSigned(NewSign); 315 ConvVal = ConvVal.extend(Val.getBitWidth()); 316 ConvVal.setIsSigned(Val.isSigned()); 317 if (ConvVal != Val) 318 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 319 320 // Regardless of whether a diagnostic was emitted, really do the 321 // truncation. 322 Val = Val.trunc(NewWidth); 323 Val.setIsSigned(NewSign); 324 } else if (NewSign != Val.isSigned()) { 325 // Convert the sign to match the sign of the condition. This can cause 326 // overflow as well: unsigned(INTMIN) 327 // We don't diagnose this overflow, because it is implementation-defined 328 // behavior. 329 // FIXME: Introduce a second, default-ignored warning for this case? 330 llvm::APSInt OldVal(Val); 331 Val.setIsSigned(NewSign); 332 } 333} 334 335namespace { 336 struct CaseCompareFunctor { 337 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 338 const llvm::APSInt &RHS) { 339 return LHS.first < RHS; 340 } 341 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 342 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 343 return LHS.first < RHS.first; 344 } 345 bool operator()(const llvm::APSInt &LHS, 346 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 347 return LHS < RHS.first; 348 } 349 }; 350} 351 352/// CmpCaseVals - Comparison predicate for sorting case values. 353/// 354static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 355 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 356 if (lhs.first < rhs.first) 357 return true; 358 359 if (lhs.first == rhs.first && 360 lhs.second->getCaseLoc().getRawEncoding() 361 < rhs.second->getCaseLoc().getRawEncoding()) 362 return true; 363 return false; 364} 365 366/// CmpEnumVals - Comparison predicate for sorting enumeration values. 367/// 368static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 369 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 370{ 371 return lhs.first < rhs.first; 372} 373 374/// EqEnumVals - Comparison preficate for uniqing enumeration values. 375/// 376static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 377 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 378{ 379 return lhs.first == rhs.first; 380} 381 382/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 383/// potentially integral-promoted expression @p expr. 384static QualType GetTypeBeforeIntegralPromotion(const Expr* expr) { 385 if (const CastExpr *ImplicitCast = dyn_cast<ImplicitCastExpr>(expr)) { 386 const Expr *ExprBeforePromotion = ImplicitCast->getSubExpr(); 387 QualType TypeBeforePromotion = ExprBeforePromotion->getType(); 388 if (TypeBeforePromotion->isIntegralOrEnumerationType()) { 389 return TypeBeforePromotion; 390 } 391 } 392 return expr->getType(); 393} 394 395StmtResult 396Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 397 Decl *CondVar) { 398 ExprResult CondResult; 399 400 VarDecl *ConditionVar = 0; 401 if (CondVar) { 402 ConditionVar = cast<VarDecl>(CondVar); 403 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 404 if (CondResult.isInvalid()) 405 return StmtError(); 406 407 Cond = CondResult.release(); 408 } 409 410 if (!Cond) 411 return StmtError(); 412 413 CondResult 414 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, 415 PDiag(diag::err_typecheck_statement_requires_integer), 416 PDiag(diag::err_switch_incomplete_class_type) 417 << Cond->getSourceRange(), 418 PDiag(diag::err_switch_explicit_conversion), 419 PDiag(diag::note_switch_conversion), 420 PDiag(diag::err_switch_multiple_conversions), 421 PDiag(diag::note_switch_conversion), 422 PDiag(0)); 423 if (CondResult.isInvalid()) return StmtError(); 424 Cond = CondResult.take(); 425 426 if (!CondVar) { 427 CheckImplicitConversions(Cond, SwitchLoc); 428 CondResult = MaybeCreateExprWithCleanups(Cond); 429 if (CondResult.isInvalid()) 430 return StmtError(); 431 Cond = CondResult.take(); 432 } 433 434 getCurFunction()->setHasBranchIntoScope(); 435 436 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 437 getCurFunction()->SwitchStack.push_back(SS); 438 return Owned(SS); 439} 440 441static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 442 if (Val.getBitWidth() < BitWidth) 443 Val = Val.extend(BitWidth); 444 else if (Val.getBitWidth() > BitWidth) 445 Val = Val.trunc(BitWidth); 446 Val.setIsSigned(IsSigned); 447} 448 449StmtResult 450Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 451 Stmt *BodyStmt) { 452 SwitchStmt *SS = cast<SwitchStmt>(Switch); 453 assert(SS == getCurFunction()->SwitchStack.back() && 454 "switch stack missing push/pop!"); 455 456 SS->setBody(BodyStmt, SwitchLoc); 457 getCurFunction()->SwitchStack.pop_back(); 458 459 if (SS->getCond() == 0) 460 return StmtError(); 461 462 Expr *CondExpr = SS->getCond(); 463 Expr *CondExprBeforePromotion = CondExpr; 464 QualType CondTypeBeforePromotion = 465 GetTypeBeforeIntegralPromotion(CondExpr); 466 467 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 468 ExprResult CondResult = UsualUnaryConversions(CondExpr); 469 if (CondResult.isInvalid()) 470 return StmtError(); 471 CondExpr = CondResult.take(); 472 QualType CondType = CondExpr->getType(); 473 SS->setCond(CondExpr); 474 475 // C++ 6.4.2.p2: 476 // Integral promotions are performed (on the switch condition). 477 // 478 // A case value unrepresentable by the original switch condition 479 // type (before the promotion) doesn't make sense, even when it can 480 // be represented by the promoted type. Therefore we need to find 481 // the pre-promotion type of the switch condition. 482 if (!CondExpr->isTypeDependent()) { 483 // We have already converted the expression to an integral or enumeration 484 // type, when we started the switch statement. If we don't have an 485 // appropriate type now, just return an error. 486 if (!CondType->isIntegralOrEnumerationType()) 487 return StmtError(); 488 489 if (CondExpr->isKnownToHaveBooleanValue()) { 490 // switch(bool_expr) {...} is often a programmer error, e.g. 491 // switch(n && mask) { ... } // Doh - should be "n & mask". 492 // One can always use an if statement instead of switch(bool_expr). 493 Diag(SwitchLoc, diag::warn_bool_switch_condition) 494 << CondExpr->getSourceRange(); 495 } 496 } 497 498 // Get the bitwidth of the switched-on value before promotions. We must 499 // convert the integer case values to this width before comparison. 500 bool HasDependentValue 501 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 502 unsigned CondWidth 503 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 504 bool CondIsSigned 505 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 506 507 // Accumulate all of the case values in a vector so that we can sort them 508 // and detect duplicates. This vector contains the APInt for the case after 509 // it has been converted to the condition type. 510 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 511 CaseValsTy CaseVals; 512 513 // Keep track of any GNU case ranges we see. The APSInt is the low value. 514 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 515 CaseRangesTy CaseRanges; 516 517 DefaultStmt *TheDefaultStmt = 0; 518 519 bool CaseListIsErroneous = false; 520 521 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 522 SC = SC->getNextSwitchCase()) { 523 524 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 525 if (TheDefaultStmt) { 526 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 527 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 528 529 // FIXME: Remove the default statement from the switch block so that 530 // we'll return a valid AST. This requires recursing down the AST and 531 // finding it, not something we are set up to do right now. For now, 532 // just lop the entire switch stmt out of the AST. 533 CaseListIsErroneous = true; 534 } 535 TheDefaultStmt = DS; 536 537 } else { 538 CaseStmt *CS = cast<CaseStmt>(SC); 539 540 // We already verified that the expression has a i-c-e value (C99 541 // 6.8.4.2p3) - get that value now. 542 Expr *Lo = CS->getLHS(); 543 544 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 545 HasDependentValue = true; 546 break; 547 } 548 549 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 550 551 // Convert the value to the same width/sign as the condition. 552 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 553 Lo->getLocStart(), 554 diag::warn_case_value_overflow); 555 556 // If the LHS is not the same type as the condition, insert an implicit 557 // cast. 558 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 559 CS->setLHS(Lo); 560 561 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 562 if (CS->getRHS()) { 563 if (CS->getRHS()->isTypeDependent() || 564 CS->getRHS()->isValueDependent()) { 565 HasDependentValue = true; 566 break; 567 } 568 CaseRanges.push_back(std::make_pair(LoVal, CS)); 569 } else 570 CaseVals.push_back(std::make_pair(LoVal, CS)); 571 } 572 } 573 574 if (!HasDependentValue) { 575 // If we don't have a default statement, check whether the 576 // condition is constant. 577 llvm::APSInt ConstantCondValue; 578 bool HasConstantCond = false; 579 bool ShouldCheckConstantCond = false; 580 if (!HasDependentValue && !TheDefaultStmt) { 581 Expr::EvalResult Result; 582 HasConstantCond = CondExprBeforePromotion->Evaluate(Result, Context); 583 if (HasConstantCond) { 584 assert(Result.Val.isInt() && "switch condition evaluated to non-int"); 585 ConstantCondValue = Result.Val.getInt(); 586 ShouldCheckConstantCond = true; 587 588 assert(ConstantCondValue.getBitWidth() == CondWidth && 589 ConstantCondValue.isSigned() == CondIsSigned); 590 } 591 } 592 593 // Sort all the scalar case values so we can easily detect duplicates. 594 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 595 596 if (!CaseVals.empty()) { 597 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 598 if (ShouldCheckConstantCond && 599 CaseVals[i].first == ConstantCondValue) 600 ShouldCheckConstantCond = false; 601 602 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 603 // If we have a duplicate, report it. 604 Diag(CaseVals[i].second->getLHS()->getLocStart(), 605 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 606 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 607 diag::note_duplicate_case_prev); 608 // FIXME: We really want to remove the bogus case stmt from the 609 // substmt, but we have no way to do this right now. 610 CaseListIsErroneous = true; 611 } 612 } 613 } 614 615 // Detect duplicate case ranges, which usually don't exist at all in 616 // the first place. 617 if (!CaseRanges.empty()) { 618 // Sort all the case ranges by their low value so we can easily detect 619 // overlaps between ranges. 620 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 621 622 // Scan the ranges, computing the high values and removing empty ranges. 623 std::vector<llvm::APSInt> HiVals; 624 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 625 llvm::APSInt &LoVal = CaseRanges[i].first; 626 CaseStmt *CR = CaseRanges[i].second; 627 Expr *Hi = CR->getRHS(); 628 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 629 630 // Convert the value to the same width/sign as the condition. 631 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 632 Hi->getLocStart(), 633 diag::warn_case_value_overflow); 634 635 // If the LHS is not the same type as the condition, insert an implicit 636 // cast. 637 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 638 CR->setRHS(Hi); 639 640 // If the low value is bigger than the high value, the case is empty. 641 if (LoVal > HiVal) { 642 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 643 << SourceRange(CR->getLHS()->getLocStart(), 644 Hi->getLocEnd()); 645 CaseRanges.erase(CaseRanges.begin()+i); 646 --i, --e; 647 continue; 648 } 649 650 if (ShouldCheckConstantCond && 651 LoVal <= ConstantCondValue && 652 ConstantCondValue <= HiVal) 653 ShouldCheckConstantCond = false; 654 655 HiVals.push_back(HiVal); 656 } 657 658 // Rescan the ranges, looking for overlap with singleton values and other 659 // ranges. Since the range list is sorted, we only need to compare case 660 // ranges with their neighbors. 661 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 662 llvm::APSInt &CRLo = CaseRanges[i].first; 663 llvm::APSInt &CRHi = HiVals[i]; 664 CaseStmt *CR = CaseRanges[i].second; 665 666 // Check to see whether the case range overlaps with any 667 // singleton cases. 668 CaseStmt *OverlapStmt = 0; 669 llvm::APSInt OverlapVal(32); 670 671 // Find the smallest value >= the lower bound. If I is in the 672 // case range, then we have overlap. 673 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 674 CaseVals.end(), CRLo, 675 CaseCompareFunctor()); 676 if (I != CaseVals.end() && I->first < CRHi) { 677 OverlapVal = I->first; // Found overlap with scalar. 678 OverlapStmt = I->second; 679 } 680 681 // Find the smallest value bigger than the upper bound. 682 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 683 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 684 OverlapVal = (I-1)->first; // Found overlap with scalar. 685 OverlapStmt = (I-1)->second; 686 } 687 688 // Check to see if this case stmt overlaps with the subsequent 689 // case range. 690 if (i && CRLo <= HiVals[i-1]) { 691 OverlapVal = HiVals[i-1]; // Found overlap with range. 692 OverlapStmt = CaseRanges[i-1].second; 693 } 694 695 if (OverlapStmt) { 696 // If we have a duplicate, report it. 697 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 698 << OverlapVal.toString(10); 699 Diag(OverlapStmt->getLHS()->getLocStart(), 700 diag::note_duplicate_case_prev); 701 // FIXME: We really want to remove the bogus case stmt from the 702 // substmt, but we have no way to do this right now. 703 CaseListIsErroneous = true; 704 } 705 } 706 } 707 708 // Complain if we have a constant condition and we didn't find a match. 709 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 710 // TODO: it would be nice if we printed enums as enums, chars as 711 // chars, etc. 712 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 713 << ConstantCondValue.toString(10) 714 << CondExpr->getSourceRange(); 715 } 716 717 // Check to see if switch is over an Enum and handles all of its 718 // values. We only issue a warning if there is not 'default:', but 719 // we still do the analysis to preserve this information in the AST 720 // (which can be used by flow-based analyes). 721 // 722 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 723 724 // If switch has default case, then ignore it. 725 if (!CaseListIsErroneous && !HasConstantCond && ET) { 726 const EnumDecl *ED = ET->getDecl(); 727 typedef llvm::SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 728 EnumValsTy; 729 EnumValsTy EnumVals; 730 731 // Gather all enum values, set their type and sort them, 732 // allowing easier comparison with CaseVals. 733 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 734 EDI != ED->enumerator_end(); ++EDI) { 735 llvm::APSInt Val = EDI->getInitVal(); 736 AdjustAPSInt(Val, CondWidth, CondIsSigned); 737 EnumVals.push_back(std::make_pair(Val, *EDI)); 738 } 739 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 740 EnumValsTy::iterator EIend = 741 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 742 743 // See which case values aren't in enum. 744 // TODO: we might want to check whether case values are out of the 745 // enum even if we don't want to check whether all cases are handled. 746 if (!TheDefaultStmt) { 747 EnumValsTy::const_iterator EI = EnumVals.begin(); 748 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 749 CI != CaseVals.end(); CI++) { 750 while (EI != EIend && EI->first < CI->first) 751 EI++; 752 if (EI == EIend || EI->first > CI->first) 753 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 754 << ED->getDeclName(); 755 } 756 // See which of case ranges aren't in enum 757 EI = EnumVals.begin(); 758 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 759 RI != CaseRanges.end() && EI != EIend; RI++) { 760 while (EI != EIend && EI->first < RI->first) 761 EI++; 762 763 if (EI == EIend || EI->first != RI->first) { 764 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 765 << ED->getDeclName(); 766 } 767 768 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 769 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 770 while (EI != EIend && EI->first < Hi) 771 EI++; 772 if (EI == EIend || EI->first != Hi) 773 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 774 << ED->getDeclName(); 775 } 776 } 777 778 // Check which enum vals aren't in switch 779 CaseValsTy::const_iterator CI = CaseVals.begin(); 780 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 781 bool hasCasesNotInSwitch = false; 782 783 llvm::SmallVector<DeclarationName,8> UnhandledNames; 784 785 for (EnumValsTy::const_iterator EI = EnumVals.begin(); EI != EIend; EI++){ 786 // Drop unneeded case values 787 llvm::APSInt CIVal; 788 while (CI != CaseVals.end() && CI->first < EI->first) 789 CI++; 790 791 if (CI != CaseVals.end() && CI->first == EI->first) 792 continue; 793 794 // Drop unneeded case ranges 795 for (; RI != CaseRanges.end(); RI++) { 796 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 797 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 798 if (EI->first <= Hi) 799 break; 800 } 801 802 if (RI == CaseRanges.end() || EI->first < RI->first) { 803 hasCasesNotInSwitch = true; 804 if (!TheDefaultStmt) 805 UnhandledNames.push_back(EI->second->getDeclName()); 806 } 807 } 808 809 // Produce a nice diagnostic if multiple values aren't handled. 810 switch (UnhandledNames.size()) { 811 case 0: break; 812 case 1: 813 Diag(CondExpr->getExprLoc(), diag::warn_missing_case1) 814 << UnhandledNames[0]; 815 break; 816 case 2: 817 Diag(CondExpr->getExprLoc(), diag::warn_missing_case2) 818 << UnhandledNames[0] << UnhandledNames[1]; 819 break; 820 case 3: 821 Diag(CondExpr->getExprLoc(), diag::warn_missing_case3) 822 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 823 break; 824 default: 825 Diag(CondExpr->getExprLoc(), diag::warn_missing_cases) 826 << (unsigned)UnhandledNames.size() 827 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 828 break; 829 } 830 831 if (!hasCasesNotInSwitch) 832 SS->setAllEnumCasesCovered(); 833 } 834 } 835 836 // FIXME: If the case list was broken is some way, we don't have a good system 837 // to patch it up. Instead, just return the whole substmt as broken. 838 if (CaseListIsErroneous) 839 return StmtError(); 840 841 return Owned(SS); 842} 843 844StmtResult 845Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 846 Decl *CondVar, Stmt *Body) { 847 ExprResult CondResult(Cond.release()); 848 849 VarDecl *ConditionVar = 0; 850 if (CondVar) { 851 ConditionVar = cast<VarDecl>(CondVar); 852 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 853 if (CondResult.isInvalid()) 854 return StmtError(); 855 } 856 Expr *ConditionExpr = CondResult.take(); 857 if (!ConditionExpr) 858 return StmtError(); 859 860 DiagnoseUnusedExprResult(Body); 861 862 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 863 Body, WhileLoc)); 864} 865 866StmtResult 867Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 868 SourceLocation WhileLoc, SourceLocation CondLParen, 869 Expr *Cond, SourceLocation CondRParen) { 870 assert(Cond && "ActOnDoStmt(): missing expression"); 871 872 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 873 if (CondResult.isInvalid() || CondResult.isInvalid()) 874 return StmtError(); 875 Cond = CondResult.take(); 876 877 CheckImplicitConversions(Cond, DoLoc); 878 CondResult = MaybeCreateExprWithCleanups(Cond); 879 if (CondResult.isInvalid()) 880 return StmtError(); 881 Cond = CondResult.take(); 882 883 DiagnoseUnusedExprResult(Body); 884 885 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 886} 887 888StmtResult 889Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 890 Stmt *First, FullExprArg second, Decl *secondVar, 891 FullExprArg third, 892 SourceLocation RParenLoc, Stmt *Body) { 893 if (!getLangOptions().CPlusPlus) { 894 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 895 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 896 // declare identifiers for objects having storage class 'auto' or 897 // 'register'. 898 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 899 DI!=DE; ++DI) { 900 VarDecl *VD = dyn_cast<VarDecl>(*DI); 901 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 902 VD = 0; 903 if (VD == 0) 904 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 905 // FIXME: mark decl erroneous! 906 } 907 } 908 } 909 910 ExprResult SecondResult(second.release()); 911 VarDecl *ConditionVar = 0; 912 if (secondVar) { 913 ConditionVar = cast<VarDecl>(secondVar); 914 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 915 if (SecondResult.isInvalid()) 916 return StmtError(); 917 } 918 919 Expr *Third = third.release().takeAs<Expr>(); 920 921 DiagnoseUnusedExprResult(First); 922 DiagnoseUnusedExprResult(Third); 923 DiagnoseUnusedExprResult(Body); 924 925 return Owned(new (Context) ForStmt(Context, First, 926 SecondResult.take(), ConditionVar, 927 Third, Body, ForLoc, LParenLoc, 928 RParenLoc)); 929} 930 931/// In an Objective C collection iteration statement: 932/// for (x in y) 933/// x can be an arbitrary l-value expression. Bind it up as a 934/// full-expression. 935StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 936 CheckImplicitConversions(E); 937 ExprResult Result = MaybeCreateExprWithCleanups(E); 938 if (Result.isInvalid()) return StmtError(); 939 return Owned(static_cast<Stmt*>(Result.get())); 940} 941 942StmtResult 943Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 944 SourceLocation LParenLoc, 945 Stmt *First, Expr *Second, 946 SourceLocation RParenLoc, Stmt *Body) { 947 if (First) { 948 QualType FirstType; 949 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 950 if (!DS->isSingleDecl()) 951 return StmtError(Diag((*DS->decl_begin())->getLocation(), 952 diag::err_toomany_element_decls)); 953 954 Decl *D = DS->getSingleDecl(); 955 FirstType = cast<ValueDecl>(D)->getType(); 956 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 957 // declare identifiers for objects having storage class 'auto' or 958 // 'register'. 959 VarDecl *VD = cast<VarDecl>(D); 960 if (VD->isLocalVarDecl() && !VD->hasLocalStorage()) 961 return StmtError(Diag(VD->getLocation(), 962 diag::err_non_variable_decl_in_for)); 963 } else { 964 Expr *FirstE = cast<Expr>(First); 965 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 966 return StmtError(Diag(First->getLocStart(), 967 diag::err_selector_element_not_lvalue) 968 << First->getSourceRange()); 969 970 FirstType = static_cast<Expr*>(First)->getType(); 971 } 972 if (!FirstType->isDependentType() && 973 !FirstType->isObjCObjectPointerType() && 974 !FirstType->isBlockPointerType()) 975 Diag(ForLoc, diag::err_selector_element_type) 976 << FirstType << First->getSourceRange(); 977 } 978 if (Second && !Second->isTypeDependent()) { 979 ExprResult Result = DefaultFunctionArrayLvalueConversion(Second); 980 if (Result.isInvalid()) 981 return StmtError(); 982 Second = Result.take(); 983 QualType SecondType = Second->getType(); 984 if (!SecondType->isObjCObjectPointerType()) 985 Diag(ForLoc, diag::err_collection_expr_type) 986 << SecondType << Second->getSourceRange(); 987 else if (const ObjCObjectPointerType *OPT = 988 SecondType->getAsObjCInterfacePointerType()) { 989 llvm::SmallVector<IdentifierInfo *, 4> KeyIdents; 990 IdentifierInfo* selIdent = 991 &Context.Idents.get("countByEnumeratingWithState"); 992 KeyIdents.push_back(selIdent); 993 selIdent = &Context.Idents.get("objects"); 994 KeyIdents.push_back(selIdent); 995 selIdent = &Context.Idents.get("count"); 996 KeyIdents.push_back(selIdent); 997 Selector CSelector = Context.Selectors.getSelector(3, &KeyIdents[0]); 998 if (ObjCInterfaceDecl *IDecl = OPT->getInterfaceDecl()) { 999 if (!IDecl->isForwardDecl() && 1000 !IDecl->lookupInstanceMethod(CSelector) && 1001 !LookupMethodInQualifiedType(CSelector, OPT, true)) { 1002 // Must further look into private implementation methods. 1003 if (!LookupPrivateInstanceMethod(CSelector, IDecl)) 1004 Diag(ForLoc, diag::warn_collection_expr_type) 1005 << SecondType << CSelector << Second->getSourceRange(); 1006 } 1007 } 1008 } 1009 } 1010 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 1011 ForLoc, RParenLoc)); 1012} 1013 1014namespace { 1015 1016enum BeginEndFunction { 1017 BEF_begin, 1018 BEF_end 1019}; 1020 1021/// Build a variable declaration for a for-range statement. 1022static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1023 QualType Type, const char *Name) { 1024 DeclContext *DC = SemaRef.CurContext; 1025 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1026 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1027 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1028 TInfo, SC_Auto, SC_None); 1029 Decl->setImplicit(); 1030 return Decl; 1031} 1032 1033/// Finish building a variable declaration for a for-range statement. 1034/// \return true if an error occurs. 1035static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1036 SourceLocation Loc, int diag) { 1037 // Deduce the type for the iterator variable now rather than leaving it to 1038 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1039 TypeSourceInfo *InitTSI = 0; 1040 if (Init->getType()->isVoidType() || 1041 !SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI)) 1042 SemaRef.Diag(Loc, diag) << Init->getType(); 1043 if (!InitTSI) { 1044 Decl->setInvalidDecl(); 1045 return true; 1046 } 1047 Decl->setTypeSourceInfo(InitTSI); 1048 Decl->setType(InitTSI->getType()); 1049 1050 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1051 /*TypeMayContainAuto=*/false); 1052 SemaRef.FinalizeDeclaration(Decl); 1053 SemaRef.CurContext->addHiddenDecl(Decl); 1054 return false; 1055} 1056 1057/// Produce a note indicating which begin/end function was implicitly called 1058/// by a C++0x for-range statement. This is often not obvious from the code, 1059/// nor from the diagnostics produced when analysing the implicit expressions 1060/// required in a for-range statement. 1061void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1062 BeginEndFunction BEF) { 1063 CallExpr *CE = dyn_cast<CallExpr>(E); 1064 if (!CE) 1065 return; 1066 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1067 if (!D) 1068 return; 1069 SourceLocation Loc = D->getLocation(); 1070 1071 std::string Description; 1072 bool IsTemplate = false; 1073 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1074 Description = SemaRef.getTemplateArgumentBindingsText( 1075 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1076 IsTemplate = true; 1077 } 1078 1079 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1080 << BEF << IsTemplate << Description << E->getType(); 1081} 1082 1083/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1084/// given LookupResult is non-empty, it is assumed to describe a member which 1085/// will be invoked. Otherwise, the function will be found via argument 1086/// dependent lookup. 1087static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1088 SourceLocation Loc, 1089 VarDecl *Decl, 1090 BeginEndFunction BEF, 1091 const DeclarationNameInfo &NameInfo, 1092 LookupResult &MemberLookup, 1093 Expr *Range) { 1094 ExprResult CallExpr; 1095 if (!MemberLookup.empty()) { 1096 ExprResult MemberRef = 1097 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1098 /*IsPtr=*/false, CXXScopeSpec(), 1099 /*Qualifier=*/0, MemberLookup, 1100 /*TemplateArgs=*/0); 1101 if (MemberRef.isInvalid()) 1102 return ExprError(); 1103 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1104 Loc, 0); 1105 if (CallExpr.isInvalid()) 1106 return ExprError(); 1107 } else { 1108 UnresolvedSet<0> FoundNames; 1109 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1110 // std is an associated namespace. 1111 UnresolvedLookupExpr *Fn = 1112 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1113 NestedNameSpecifierLoc(), NameInfo, 1114 /*NeedsADL=*/true, /*Overloaded=*/false, 1115 FoundNames.begin(), FoundNames.end(), 1116 /*LookInStdNamespace=*/true); 1117 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1118 0); 1119 if (CallExpr.isInvalid()) { 1120 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1121 << Range->getType(); 1122 return ExprError(); 1123 } 1124 } 1125 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1126 diag::err_for_range_iter_deduction_failure)) { 1127 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1128 return ExprError(); 1129 } 1130 return CallExpr; 1131} 1132 1133} 1134 1135/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1136/// 1137/// C++0x [stmt.ranged]: 1138/// A range-based for statement is equivalent to 1139/// 1140/// { 1141/// auto && __range = range-init; 1142/// for ( auto __begin = begin-expr, 1143/// __end = end-expr; 1144/// __begin != __end; 1145/// ++__begin ) { 1146/// for-range-declaration = *__begin; 1147/// statement 1148/// } 1149/// } 1150/// 1151/// The body of the loop is not available yet, since it cannot be analysed until 1152/// we have determined the type of the for-range-declaration. 1153StmtResult 1154Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1155 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1156 SourceLocation RParenLoc) { 1157 if (!First || !Range) 1158 return StmtError(); 1159 1160 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1161 assert(DS && "first part of for range not a decl stmt"); 1162 1163 if (!DS->isSingleDecl()) { 1164 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1165 return StmtError(); 1166 } 1167 if (DS->getSingleDecl()->isInvalidDecl()) 1168 return StmtError(); 1169 1170 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1171 return StmtError(); 1172 1173 // Build auto && __range = range-init 1174 SourceLocation RangeLoc = Range->getLocStart(); 1175 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1176 Context.getAutoRRefDeductType(), 1177 "__range"); 1178 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1179 diag::err_for_range_deduction_failure)) 1180 return StmtError(); 1181 1182 // Claim the type doesn't contain auto: we've already done the checking. 1183 DeclGroupPtrTy RangeGroup = 1184 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1185 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1186 if (RangeDecl.isInvalid()) 1187 return StmtError(); 1188 1189 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1190 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1191 RParenLoc); 1192} 1193 1194/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1195StmtResult 1196Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1197 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1198 Expr *Inc, Stmt *LoopVarDecl, 1199 SourceLocation RParenLoc) { 1200 Scope *S = getCurScope(); 1201 1202 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1203 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1204 QualType RangeVarType = RangeVar->getType(); 1205 1206 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1207 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1208 1209 StmtResult BeginEndDecl = BeginEnd; 1210 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1211 1212 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1213 SourceLocation RangeLoc = RangeVar->getLocation(); 1214 1215 ExprResult RangeRef = BuildDeclRefExpr(RangeVar, 1216 RangeVarType.getNonReferenceType(), 1217 VK_LValue, ColonLoc); 1218 if (RangeRef.isInvalid()) 1219 return StmtError(); 1220 1221 QualType AutoType = Context.getAutoDeductType(); 1222 Expr *Range = RangeVar->getInit(); 1223 if (!Range) 1224 return StmtError(); 1225 QualType RangeType = Range->getType(); 1226 1227 if (RequireCompleteType(RangeLoc, RangeType, 1228 PDiag(diag::err_for_range_incomplete_type))) 1229 return StmtError(); 1230 1231 // Build auto __begin = begin-expr, __end = end-expr. 1232 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1233 "__begin"); 1234 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1235 "__end"); 1236 1237 // Build begin-expr and end-expr and attach to __begin and __end variables. 1238 ExprResult BeginExpr, EndExpr; 1239 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1240 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1241 // __range + __bound, respectively, where __bound is the array bound. If 1242 // _RangeT is an array of unknown size or an array of incomplete type, 1243 // the program is ill-formed; 1244 1245 // begin-expr is __range. 1246 BeginExpr = RangeRef; 1247 if (FinishForRangeVarDecl(*this, BeginVar, RangeRef.get(), ColonLoc, 1248 diag::err_for_range_iter_deduction_failure)) { 1249 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1250 return StmtError(); 1251 } 1252 1253 // Find the array bound. 1254 ExprResult BoundExpr; 1255 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1256 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1257 Context.getPointerDiffType(), 1258 RangeLoc)); 1259 else if (const VariableArrayType *VAT = 1260 dyn_cast<VariableArrayType>(UnqAT)) 1261 BoundExpr = VAT->getSizeExpr(); 1262 else { 1263 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1264 // UnqAT is not incomplete and Range is not type-dependent. 1265 assert(0 && "Unexpected array type in for-range"); 1266 return StmtError(); 1267 } 1268 1269 // end-expr is __range + __bound. 1270 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, RangeRef.get(), 1271 BoundExpr.get()); 1272 if (EndExpr.isInvalid()) 1273 return StmtError(); 1274 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1275 diag::err_for_range_iter_deduction_failure)) { 1276 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1277 return StmtError(); 1278 } 1279 } else { 1280 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1281 ColonLoc); 1282 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1283 ColonLoc); 1284 1285 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1286 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1287 1288 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1289 // - if _RangeT is a class type, the unqualified-ids begin and end are 1290 // looked up in the scope of class _RangeT as if by class member access 1291 // lookup (3.4.5), and if either (or both) finds at least one 1292 // declaration, begin-expr and end-expr are __range.begin() and 1293 // __range.end(), respectively; 1294 LookupQualifiedName(BeginMemberLookup, D); 1295 LookupQualifiedName(EndMemberLookup, D); 1296 1297 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1298 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1299 << RangeType << BeginMemberLookup.empty(); 1300 return StmtError(); 1301 } 1302 } else { 1303 // - otherwise, begin-expr and end-expr are begin(__range) and 1304 // end(__range), respectively, where begin and end are looked up with 1305 // argument-dependent lookup (3.4.2). For the purposes of this name 1306 // lookup, namespace std is an associated namespace. 1307 } 1308 1309 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1310 BEF_begin, BeginNameInfo, 1311 BeginMemberLookup, RangeRef.get()); 1312 if (BeginExpr.isInvalid()) 1313 return StmtError(); 1314 1315 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1316 BEF_end, EndNameInfo, 1317 EndMemberLookup, RangeRef.get()); 1318 if (EndExpr.isInvalid()) 1319 return StmtError(); 1320 } 1321 1322 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1323 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1324 if (!Context.hasSameType(BeginType, EndType)) { 1325 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1326 << BeginType << EndType; 1327 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1328 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1329 } 1330 1331 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1332 // Claim the type doesn't contain auto: we've already done the checking. 1333 DeclGroupPtrTy BeginEndGroup = 1334 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1335 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1336 1337 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, 1338 BeginType.getNonReferenceType(), 1339 VK_LValue, ColonLoc); 1340 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1341 VK_LValue, ColonLoc); 1342 1343 // Build and check __begin != __end expression. 1344 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1345 BeginRef.get(), EndRef.get()); 1346 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1347 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1348 if (NotEqExpr.isInvalid()) { 1349 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1350 if (!Context.hasSameType(BeginType, EndType)) 1351 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1352 return StmtError(); 1353 } 1354 1355 // Build and check ++__begin expression. 1356 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1357 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1358 if (IncrExpr.isInvalid()) { 1359 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1360 return StmtError(); 1361 } 1362 1363 // Build and check *__begin expression. 1364 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1365 if (DerefExpr.isInvalid()) { 1366 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1367 return StmtError(); 1368 } 1369 1370 // Attach *__begin as initializer for VD. 1371 if (!LoopVar->isInvalidDecl()) { 1372 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1373 /*TypeMayContainAuto=*/true); 1374 if (LoopVar->isInvalidDecl()) 1375 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1376 } 1377 } 1378 1379 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1380 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1381 NotEqExpr.take(), IncrExpr.take(), 1382 LoopVarDS, /*Body=*/0, ForLoc, 1383 ColonLoc, RParenLoc)); 1384} 1385 1386/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1387/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1388/// body cannot be performed until after the type of the range variable is 1389/// determined. 1390StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1391 if (!S || !B) 1392 return StmtError(); 1393 1394 cast<CXXForRangeStmt>(S)->setBody(B); 1395 return S; 1396} 1397 1398StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1399 SourceLocation LabelLoc, 1400 LabelDecl *TheDecl) { 1401 getCurFunction()->setHasBranchIntoScope(); 1402 TheDecl->setUsed(); 1403 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1404} 1405 1406StmtResult 1407Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1408 Expr *E) { 1409 // Convert operand to void* 1410 if (!E->isTypeDependent()) { 1411 QualType ETy = E->getType(); 1412 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1413 ExprResult ExprRes = Owned(E); 1414 AssignConvertType ConvTy = 1415 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1416 if (ExprRes.isInvalid()) 1417 return StmtError(); 1418 E = ExprRes.take(); 1419 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1420 return StmtError(); 1421 } 1422 1423 getCurFunction()->setHasIndirectGoto(); 1424 1425 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1426} 1427 1428StmtResult 1429Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1430 Scope *S = CurScope->getContinueParent(); 1431 if (!S) { 1432 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1433 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1434 } 1435 1436 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1437} 1438 1439StmtResult 1440Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1441 Scope *S = CurScope->getBreakParent(); 1442 if (!S) { 1443 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1444 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1445 } 1446 1447 return Owned(new (Context) BreakStmt(BreakLoc)); 1448} 1449 1450/// \brief Determine whether the given expression is a candidate for 1451/// copy elision in either a return statement or a throw expression. 1452/// 1453/// \param ReturnType If we're determining the copy elision candidate for 1454/// a return statement, this is the return type of the function. If we're 1455/// determining the copy elision candidate for a throw expression, this will 1456/// be a NULL type. 1457/// 1458/// \param E The expression being returned from the function or block, or 1459/// being thrown. 1460/// 1461/// \param AllowFunctionParameter Whether we allow function parameters to 1462/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1463/// we re-use this logic to determine whether we should try to move as part of 1464/// a return or throw (which does allow function parameters). 1465/// 1466/// \returns The NRVO candidate variable, if the return statement may use the 1467/// NRVO, or NULL if there is no such candidate. 1468const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1469 Expr *E, 1470 bool AllowFunctionParameter) { 1471 QualType ExprType = E->getType(); 1472 // - in a return statement in a function with ... 1473 // ... a class return type ... 1474 if (!ReturnType.isNull()) { 1475 if (!ReturnType->isRecordType()) 1476 return 0; 1477 // ... the same cv-unqualified type as the function return type ... 1478 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1479 return 0; 1480 } 1481 1482 // ... the expression is the name of a non-volatile automatic object 1483 // (other than a function or catch-clause parameter)) ... 1484 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1485 if (!DR) 1486 return 0; 1487 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1488 if (!VD) 1489 return 0; 1490 1491 if (VD->hasLocalStorage() && !VD->isExceptionVariable() && 1492 !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() && 1493 !VD->getType().isVolatileQualified() && 1494 ((VD->getKind() == Decl::Var) || 1495 (AllowFunctionParameter && VD->getKind() == Decl::ParmVar))) 1496 return VD; 1497 1498 return 0; 1499} 1500 1501/// \brief Perform the initialization of a potentially-movable value, which 1502/// is the result of return value. 1503/// 1504/// This routine implements C++0x [class.copy]p33, which attempts to treat 1505/// returned lvalues as rvalues in certain cases (to prefer move construction), 1506/// then falls back to treating them as lvalues if that failed. 1507ExprResult 1508Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1509 const VarDecl *NRVOCandidate, 1510 QualType ResultType, 1511 Expr *Value) { 1512 // C++0x [class.copy]p33: 1513 // When the criteria for elision of a copy operation are met or would 1514 // be met save for the fact that the source object is a function 1515 // parameter, and the object to be copied is designated by an lvalue, 1516 // overload resolution to select the constructor for the copy is first 1517 // performed as if the object were designated by an rvalue. 1518 ExprResult Res = ExprError(); 1519 if (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true)) { 1520 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1521 Value->getType(), CK_LValueToRValue, 1522 Value, VK_XValue); 1523 1524 Expr *InitExpr = &AsRvalue; 1525 InitializationKind Kind 1526 = InitializationKind::CreateCopy(Value->getLocStart(), 1527 Value->getLocStart()); 1528 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 1529 1530 // [...] If overload resolution fails, or if the type of the first 1531 // parameter of the selected constructor is not an rvalue reference 1532 // to the object's type (possibly cv-qualified), overload resolution 1533 // is performed again, considering the object as an lvalue. 1534 if (Seq) { 1535 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 1536 StepEnd = Seq.step_end(); 1537 Step != StepEnd; ++Step) { 1538 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 1539 continue; 1540 1541 CXXConstructorDecl *Constructor 1542 = cast<CXXConstructorDecl>(Step->Function.Function); 1543 1544 const RValueReferenceType *RRefType 1545 = Constructor->getParamDecl(0)->getType() 1546 ->getAs<RValueReferenceType>(); 1547 1548 // If we don't meet the criteria, break out now. 1549 if (!RRefType || 1550 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 1551 Context.getTypeDeclType(Constructor->getParent()))) 1552 break; 1553 1554 // Promote "AsRvalue" to the heap, since we now need this 1555 // expression node to persist. 1556 Value = ImplicitCastExpr::Create(Context, Value->getType(), 1557 CK_LValueToRValue, Value, 0, 1558 VK_XValue); 1559 1560 // Complete type-checking the initialization of the return type 1561 // using the constructor we found. 1562 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 1563 } 1564 } 1565 } 1566 1567 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 1568 // above, or overload resolution failed. Either way, we need to try 1569 // (again) now with the return value expression as written. 1570 if (Res.isInvalid()) 1571 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 1572 1573 return Res; 1574} 1575 1576/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 1577/// 1578StmtResult 1579Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1580 // If this is the first return we've seen in the block, infer the type of 1581 // the block from it. 1582 BlockScopeInfo *CurBlock = getCurBlock(); 1583 if (CurBlock->ReturnType.isNull()) { 1584 if (RetValExp) { 1585 // Don't call UsualUnaryConversions(), since we don't want to do 1586 // integer promotions here. 1587 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 1588 if (Result.isInvalid()) 1589 return StmtError(); 1590 RetValExp = Result.take(); 1591 1592 if (!RetValExp->isTypeDependent()) { 1593 CurBlock->ReturnType = RetValExp->getType(); 1594 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) { 1595 // We have to remove a 'const' added to copied-in variable which was 1596 // part of the implementation spec. and not the actual qualifier for 1597 // the variable. 1598 if (CDRE->isConstQualAdded()) 1599 CurBlock->ReturnType.removeLocalConst(); // FIXME: local??? 1600 } 1601 } else 1602 CurBlock->ReturnType = Context.DependentTy; 1603 } else 1604 CurBlock->ReturnType = Context.VoidTy; 1605 } 1606 QualType FnRetType = CurBlock->ReturnType; 1607 1608 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 1609 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 1610 << getCurFunctionOrMethodDecl()->getDeclName(); 1611 return StmtError(); 1612 } 1613 1614 // Otherwise, verify that this result type matches the previous one. We are 1615 // pickier with blocks than for normal functions because we don't have GCC 1616 // compatibility to worry about here. 1617 ReturnStmt *Result = 0; 1618 if (CurBlock->ReturnType->isVoidType()) { 1619 if (RetValExp && !RetValExp->isTypeDependent() && 1620 (!getLangOptions().CPlusPlus || !RetValExp->getType()->isVoidType())) { 1621 Diag(ReturnLoc, diag::err_return_block_has_expr); 1622 RetValExp = 0; 1623 } 1624 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1625 } else if (!RetValExp) { 1626 if (!CurBlock->ReturnType->isDependentType()) 1627 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 1628 1629 Result = new (Context) ReturnStmt(ReturnLoc, 0, 0); 1630 } else { 1631 const VarDecl *NRVOCandidate = 0; 1632 1633 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1634 // we have a non-void block with an expression, continue checking 1635 1636 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1637 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1638 // function return. 1639 1640 // In C++ the return statement is handled via a copy initialization. 1641 // the C version of which boils down to CheckSingleAssignmentConstraints. 1642 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1643 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1644 FnRetType, 1645 NRVOCandidate != 0); 1646 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1647 FnRetType, RetValExp); 1648 if (Res.isInvalid()) { 1649 // FIXME: Cleanup temporaries here, anyway? 1650 return StmtError(); 1651 } 1652 1653 if (RetValExp) { 1654 CheckImplicitConversions(RetValExp, ReturnLoc); 1655 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1656 } 1657 1658 RetValExp = Res.takeAs<Expr>(); 1659 if (RetValExp) 1660 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1661 } 1662 1663 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1664 } 1665 1666 // If we need to check for the named return value optimization, save the 1667 // return statement in our scope for later processing. 1668 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1669 !CurContext->isDependentContext()) 1670 FunctionScopes.back()->Returns.push_back(Result); 1671 1672 return Owned(Result); 1673} 1674 1675StmtResult 1676Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1677 // Check for unexpanded parameter packs. 1678 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 1679 return StmtError(); 1680 1681 if (getCurBlock()) 1682 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 1683 1684 QualType FnRetType; 1685 QualType DeclaredRetType; 1686 if (const FunctionDecl *FD = getCurFunctionDecl()) { 1687 FnRetType = FD->getResultType(); 1688 DeclaredRetType = FnRetType; 1689 if (FD->hasAttr<NoReturnAttr>() || 1690 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 1691 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 1692 << getCurFunctionOrMethodDecl()->getDeclName(); 1693 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 1694 DeclaredRetType = MD->getResultType(); 1695 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 1696 // In the implementation of a method with a related return type, the 1697 // type used to type-check the validity of return statements within the 1698 // method body is a pointer to the type of the class being implemented. 1699 FnRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 1700 FnRetType = Context.getObjCObjectPointerType(FnRetType); 1701 } else { 1702 FnRetType = DeclaredRetType; 1703 } 1704 } else // If we don't have a function/method context, bail. 1705 return StmtError(); 1706 1707 ReturnStmt *Result = 0; 1708 if (FnRetType->isVoidType()) { 1709 if (RetValExp) { 1710 if (!RetValExp->isTypeDependent()) { 1711 // C99 6.8.6.4p1 (ext_ since GCC warns) 1712 unsigned D = diag::ext_return_has_expr; 1713 if (RetValExp->getType()->isVoidType()) 1714 D = diag::ext_return_has_void_expr; 1715 else { 1716 ExprResult Result = Owned(RetValExp); 1717 Result = IgnoredValueConversions(Result.take()); 1718 if (Result.isInvalid()) 1719 return StmtError(); 1720 RetValExp = Result.take(); 1721 RetValExp = ImpCastExprToType(RetValExp, 1722 Context.VoidTy, CK_ToVoid).take(); 1723 } 1724 1725 // return (some void expression); is legal in C++. 1726 if (D != diag::ext_return_has_void_expr || 1727 !getLangOptions().CPlusPlus) { 1728 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 1729 Diag(ReturnLoc, D) 1730 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 1731 << RetValExp->getSourceRange(); 1732 } 1733 } 1734 1735 CheckImplicitConversions(RetValExp, ReturnLoc); 1736 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1737 } 1738 1739 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1740 } else if (!RetValExp && !FnRetType->isDependentType()) { 1741 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 1742 // C99 6.8.6.4p1 (ext_ since GCC warns) 1743 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 1744 1745 if (FunctionDecl *FD = getCurFunctionDecl()) 1746 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 1747 else 1748 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 1749 Result = new (Context) ReturnStmt(ReturnLoc); 1750 } else { 1751 const VarDecl *NRVOCandidate = 0; 1752 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1753 // we have a non-void function with an expression, continue checking 1754 1755 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1756 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1757 // function return. 1758 1759 // In C++ the return statement is handled via a copy initialization. 1760 // the C version of which boils down to CheckSingleAssignmentConstraints. 1761 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1762 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1763 FnRetType, 1764 NRVOCandidate != 0); 1765 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1766 FnRetType, RetValExp); 1767 if (Res.isInvalid()) { 1768 // FIXME: Cleanup temporaries here, anyway? 1769 return StmtError(); 1770 } 1771 1772 RetValExp = Res.takeAs<Expr>(); 1773 if (RetValExp) 1774 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1775 } 1776 1777 if (RetValExp) { 1778 // If we type-checked an Objective-C method's return type based 1779 // on a related return type, we may need to adjust the return 1780 // type again. Do so now. 1781 if (DeclaredRetType != FnRetType) { 1782 ExprResult result = PerformImplicitConversion(RetValExp, 1783 DeclaredRetType, 1784 AA_Returning); 1785 if (result.isInvalid()) return StmtError(); 1786 RetValExp = result.take(); 1787 } 1788 1789 CheckImplicitConversions(RetValExp, ReturnLoc); 1790 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1791 } 1792 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1793 } 1794 1795 // If we need to check for the named return value optimization, save the 1796 // return statement in our scope for later processing. 1797 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1798 !CurContext->isDependentContext()) 1799 FunctionScopes.back()->Returns.push_back(Result); 1800 1801 return Owned(Result); 1802} 1803 1804/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 1805/// ignore "noop" casts in places where an lvalue is required by an inline asm. 1806/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 1807/// provide a strong guidance to not use it. 1808/// 1809/// This method checks to see if the argument is an acceptable l-value and 1810/// returns false if it is a case we can handle. 1811static bool CheckAsmLValue(const Expr *E, Sema &S) { 1812 // Type dependent expressions will be checked during instantiation. 1813 if (E->isTypeDependent()) 1814 return false; 1815 1816 if (E->isLValue()) 1817 return false; // Cool, this is an lvalue. 1818 1819 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 1820 // are supposed to allow. 1821 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 1822 if (E != E2 && E2->isLValue()) { 1823 if (!S.getLangOptions().HeinousExtensions) 1824 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 1825 << E->getSourceRange(); 1826 else 1827 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 1828 << E->getSourceRange(); 1829 // Accept, even if we emitted an error diagnostic. 1830 return false; 1831 } 1832 1833 // None of the above, just randomly invalid non-lvalue. 1834 return true; 1835} 1836 1837/// isOperandMentioned - Return true if the specified operand # is mentioned 1838/// anywhere in the decomposed asm string. 1839static bool isOperandMentioned(unsigned OpNo, 1840 llvm::ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 1841 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 1842 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 1843 if (!Piece.isOperand()) continue; 1844 1845 // If this is a reference to the input and if the input was the smaller 1846 // one, then we have to reject this asm. 1847 if (Piece.getOperandNo() == OpNo) 1848 return true; 1849 } 1850 1851 return false; 1852} 1853 1854StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 1855 bool IsVolatile, unsigned NumOutputs, 1856 unsigned NumInputs, IdentifierInfo **Names, 1857 MultiExprArg constraints, MultiExprArg exprs, 1858 Expr *asmString, MultiExprArg clobbers, 1859 SourceLocation RParenLoc, bool MSAsm) { 1860 unsigned NumClobbers = clobbers.size(); 1861 StringLiteral **Constraints = 1862 reinterpret_cast<StringLiteral**>(constraints.get()); 1863 Expr **Exprs = exprs.get(); 1864 StringLiteral *AsmString = cast<StringLiteral>(asmString); 1865 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 1866 1867 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 1868 1869 // The parser verifies that there is a string literal here. 1870 if (AsmString->isWide()) 1871 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 1872 << AsmString->getSourceRange()); 1873 1874 for (unsigned i = 0; i != NumOutputs; i++) { 1875 StringLiteral *Literal = Constraints[i]; 1876 if (Literal->isWide()) 1877 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1878 << Literal->getSourceRange()); 1879 1880 llvm::StringRef OutputName; 1881 if (Names[i]) 1882 OutputName = Names[i]->getName(); 1883 1884 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 1885 if (!Context.Target.validateOutputConstraint(Info)) 1886 return StmtError(Diag(Literal->getLocStart(), 1887 diag::err_asm_invalid_output_constraint) 1888 << Info.getConstraintStr()); 1889 1890 // Check that the output exprs are valid lvalues. 1891 Expr *OutputExpr = Exprs[i]; 1892 if (CheckAsmLValue(OutputExpr, *this)) { 1893 return StmtError(Diag(OutputExpr->getLocStart(), 1894 diag::err_asm_invalid_lvalue_in_output) 1895 << OutputExpr->getSourceRange()); 1896 } 1897 1898 OutputConstraintInfos.push_back(Info); 1899 } 1900 1901 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 1902 1903 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 1904 StringLiteral *Literal = Constraints[i]; 1905 if (Literal->isWide()) 1906 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1907 << Literal->getSourceRange()); 1908 1909 llvm::StringRef InputName; 1910 if (Names[i]) 1911 InputName = Names[i]->getName(); 1912 1913 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 1914 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(), 1915 NumOutputs, Info)) { 1916 return StmtError(Diag(Literal->getLocStart(), 1917 diag::err_asm_invalid_input_constraint) 1918 << Info.getConstraintStr()); 1919 } 1920 1921 Expr *InputExpr = Exprs[i]; 1922 1923 // Only allow void types for memory constraints. 1924 if (Info.allowsMemory() && !Info.allowsRegister()) { 1925 if (CheckAsmLValue(InputExpr, *this)) 1926 return StmtError(Diag(InputExpr->getLocStart(), 1927 diag::err_asm_invalid_lvalue_in_input) 1928 << Info.getConstraintStr() 1929 << InputExpr->getSourceRange()); 1930 } 1931 1932 if (Info.allowsRegister()) { 1933 if (InputExpr->getType()->isVoidType()) { 1934 return StmtError(Diag(InputExpr->getLocStart(), 1935 diag::err_asm_invalid_type_in_input) 1936 << InputExpr->getType() << Info.getConstraintStr() 1937 << InputExpr->getSourceRange()); 1938 } 1939 } 1940 1941 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 1942 if (Result.isInvalid()) 1943 return StmtError(); 1944 1945 Exprs[i] = Result.take(); 1946 InputConstraintInfos.push_back(Info); 1947 } 1948 1949 // Check that the clobbers are valid. 1950 for (unsigned i = 0; i != NumClobbers; i++) { 1951 StringLiteral *Literal = Clobbers[i]; 1952 if (Literal->isWide()) 1953 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1954 << Literal->getSourceRange()); 1955 1956 llvm::StringRef Clobber = Literal->getString(); 1957 1958 if (!Context.Target.isValidGCCRegisterName(Clobber)) 1959 return StmtError(Diag(Literal->getLocStart(), 1960 diag::err_asm_unknown_register_name) << Clobber); 1961 } 1962 1963 AsmStmt *NS = 1964 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 1965 NumOutputs, NumInputs, Names, Constraints, Exprs, 1966 AsmString, NumClobbers, Clobbers, RParenLoc); 1967 // Validate the asm string, ensuring it makes sense given the operands we 1968 // have. 1969 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1970 unsigned DiagOffs; 1971 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1972 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1973 << AsmString->getSourceRange(); 1974 return StmtError(); 1975 } 1976 1977 // Validate tied input operands for type mismatches. 1978 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1979 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1980 1981 // If this is a tied constraint, verify that the output and input have 1982 // either exactly the same type, or that they are int/ptr operands with the 1983 // same size (int/long, int*/long, are ok etc). 1984 if (!Info.hasTiedOperand()) continue; 1985 1986 unsigned TiedTo = Info.getTiedOperand(); 1987 unsigned InputOpNo = i+NumOutputs; 1988 Expr *OutputExpr = Exprs[TiedTo]; 1989 Expr *InputExpr = Exprs[InputOpNo]; 1990 QualType InTy = InputExpr->getType(); 1991 QualType OutTy = OutputExpr->getType(); 1992 if (Context.hasSameType(InTy, OutTy)) 1993 continue; // All types can be tied to themselves. 1994 1995 // Decide if the input and output are in the same domain (integer/ptr or 1996 // floating point. 1997 enum AsmDomain { 1998 AD_Int, AD_FP, AD_Other 1999 } InputDomain, OutputDomain; 2000 2001 if (InTy->isIntegerType() || InTy->isPointerType()) 2002 InputDomain = AD_Int; 2003 else if (InTy->isRealFloatingType()) 2004 InputDomain = AD_FP; 2005 else 2006 InputDomain = AD_Other; 2007 2008 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2009 OutputDomain = AD_Int; 2010 else if (OutTy->isRealFloatingType()) 2011 OutputDomain = AD_FP; 2012 else 2013 OutputDomain = AD_Other; 2014 2015 // They are ok if they are the same size and in the same domain. This 2016 // allows tying things like: 2017 // void* to int* 2018 // void* to int if they are the same size. 2019 // double to long double if they are the same size. 2020 // 2021 uint64_t OutSize = Context.getTypeSize(OutTy); 2022 uint64_t InSize = Context.getTypeSize(InTy); 2023 if (OutSize == InSize && InputDomain == OutputDomain && 2024 InputDomain != AD_Other) 2025 continue; 2026 2027 // If the smaller input/output operand is not mentioned in the asm string, 2028 // then we can promote the smaller one to a larger input and the asm string 2029 // won't notice. 2030 bool SmallerValueMentioned = false; 2031 2032 // If this is a reference to the input and if the input was the smaller 2033 // one, then we have to reject this asm. 2034 if (isOperandMentioned(InputOpNo, Pieces)) { 2035 // This is a use in the asm string of the smaller operand. Since we 2036 // codegen this by promoting to a wider value, the asm will get printed 2037 // "wrong". 2038 SmallerValueMentioned |= InSize < OutSize; 2039 } 2040 if (isOperandMentioned(TiedTo, Pieces)) { 2041 // If this is a reference to the output, and if the output is the larger 2042 // value, then it's ok because we'll promote the input to the larger type. 2043 SmallerValueMentioned |= OutSize < InSize; 2044 } 2045 2046 // If the smaller value wasn't mentioned in the asm string, and if the 2047 // output was a register, just extend the shorter one to the size of the 2048 // larger one. 2049 if (!SmallerValueMentioned && InputDomain != AD_Other && 2050 OutputConstraintInfos[TiedTo].allowsRegister()) 2051 continue; 2052 2053 // Either both of the operands were mentioned or the smaller one was 2054 // mentioned. One more special case that we'll allow: if the tied input is 2055 // integer, unmentioned, and is a constant, then we'll allow truncating it 2056 // down to the size of the destination. 2057 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2058 !isOperandMentioned(InputOpNo, Pieces) && 2059 InputExpr->isEvaluatable(Context)) { 2060 CastKind castKind = 2061 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2062 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2063 Exprs[InputOpNo] = InputExpr; 2064 NS->setInputExpr(i, InputExpr); 2065 continue; 2066 } 2067 2068 Diag(InputExpr->getLocStart(), 2069 diag::err_asm_tying_incompatible_types) 2070 << InTy << OutTy << OutputExpr->getSourceRange() 2071 << InputExpr->getSourceRange(); 2072 return StmtError(); 2073 } 2074 2075 return Owned(NS); 2076} 2077 2078StmtResult 2079Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2080 SourceLocation RParen, Decl *Parm, 2081 Stmt *Body) { 2082 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2083 if (Var && Var->isInvalidDecl()) 2084 return StmtError(); 2085 2086 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2087} 2088 2089StmtResult 2090Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2091 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2092} 2093 2094StmtResult 2095Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2096 MultiStmtArg CatchStmts, Stmt *Finally) { 2097 if (!getLangOptions().ObjCExceptions) 2098 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2099 2100 getCurFunction()->setHasBranchProtectedScope(); 2101 unsigned NumCatchStmts = CatchStmts.size(); 2102 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2103 CatchStmts.release(), 2104 NumCatchStmts, 2105 Finally)); 2106} 2107 2108StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2109 Expr *Throw) { 2110 if (Throw) { 2111 ExprResult Result = DefaultLvalueConversion(Throw); 2112 if (Result.isInvalid()) 2113 return StmtError(); 2114 2115 Throw = Result.take(); 2116 QualType ThrowType = Throw->getType(); 2117 // Make sure the expression type is an ObjC pointer or "void *". 2118 if (!ThrowType->isDependentType() && 2119 !ThrowType->isObjCObjectPointerType()) { 2120 const PointerType *PT = ThrowType->getAs<PointerType>(); 2121 if (!PT || !PT->getPointeeType()->isVoidType()) 2122 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2123 << Throw->getType() << Throw->getSourceRange()); 2124 } 2125 } 2126 2127 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2128} 2129 2130StmtResult 2131Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2132 Scope *CurScope) { 2133 if (!getLangOptions().ObjCExceptions) 2134 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2135 2136 if (!Throw) { 2137 // @throw without an expression designates a rethrow (which much occur 2138 // in the context of an @catch clause). 2139 Scope *AtCatchParent = CurScope; 2140 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2141 AtCatchParent = AtCatchParent->getParent(); 2142 if (!AtCatchParent) 2143 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2144 } 2145 2146 return BuildObjCAtThrowStmt(AtLoc, Throw); 2147} 2148 2149StmtResult 2150Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2151 Stmt *SyncBody) { 2152 getCurFunction()->setHasBranchProtectedScope(); 2153 2154 ExprResult Result = DefaultLvalueConversion(SyncExpr); 2155 if (Result.isInvalid()) 2156 return StmtError(); 2157 2158 SyncExpr = Result.take(); 2159 // Make sure the expression type is an ObjC pointer or "void *". 2160 if (!SyncExpr->getType()->isDependentType() && 2161 !SyncExpr->getType()->isObjCObjectPointerType()) { 2162 const PointerType *PT = SyncExpr->getType()->getAs<PointerType>(); 2163 if (!PT || !PT->getPointeeType()->isVoidType()) 2164 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 2165 << SyncExpr->getType() << SyncExpr->getSourceRange()); 2166 } 2167 2168 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2169} 2170 2171/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2172/// and creates a proper catch handler from them. 2173StmtResult 2174Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2175 Stmt *HandlerBlock) { 2176 // There's nothing to test that ActOnExceptionDecl didn't already test. 2177 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2178 cast_or_null<VarDecl>(ExDecl), 2179 HandlerBlock)); 2180} 2181 2182namespace { 2183 2184class TypeWithHandler { 2185 QualType t; 2186 CXXCatchStmt *stmt; 2187public: 2188 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2189 : t(type), stmt(statement) {} 2190 2191 // An arbitrary order is fine as long as it places identical 2192 // types next to each other. 2193 bool operator<(const TypeWithHandler &y) const { 2194 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2195 return true; 2196 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2197 return false; 2198 else 2199 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2200 } 2201 2202 bool operator==(const TypeWithHandler& other) const { 2203 return t == other.t; 2204 } 2205 2206 CXXCatchStmt *getCatchStmt() const { return stmt; } 2207 SourceLocation getTypeSpecStartLoc() const { 2208 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2209 } 2210}; 2211 2212} 2213 2214/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2215/// handlers and creates a try statement from them. 2216StmtResult 2217Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2218 MultiStmtArg RawHandlers) { 2219 // Don't report an error if 'try' is used in system headers. 2220 if (!getLangOptions().CXXExceptions && 2221 !getSourceManager().isInSystemHeader(TryLoc)) 2222 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2223 2224 unsigned NumHandlers = RawHandlers.size(); 2225 assert(NumHandlers > 0 && 2226 "The parser shouldn't call this if there are no handlers."); 2227 Stmt **Handlers = RawHandlers.get(); 2228 2229 llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2230 2231 for (unsigned i = 0; i < NumHandlers; ++i) { 2232 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 2233 if (!Handler->getExceptionDecl()) { 2234 if (i < NumHandlers - 1) 2235 return StmtError(Diag(Handler->getLocStart(), 2236 diag::err_early_catch_all)); 2237 2238 continue; 2239 } 2240 2241 const QualType CaughtType = Handler->getCaughtType(); 2242 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2243 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2244 } 2245 2246 // Detect handlers for the same type as an earlier one. 2247 if (NumHandlers > 1) { 2248 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2249 2250 TypeWithHandler prev = TypesWithHandlers[0]; 2251 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2252 TypeWithHandler curr = TypesWithHandlers[i]; 2253 2254 if (curr == prev) { 2255 Diag(curr.getTypeSpecStartLoc(), 2256 diag::warn_exception_caught_by_earlier_handler) 2257 << curr.getCatchStmt()->getCaughtType().getAsString(); 2258 Diag(prev.getTypeSpecStartLoc(), 2259 diag::note_previous_exception_handler) 2260 << prev.getCatchStmt()->getCaughtType().getAsString(); 2261 } 2262 2263 prev = curr; 2264 } 2265 } 2266 2267 getCurFunction()->setHasBranchProtectedScope(); 2268 2269 // FIXME: We should detect handlers that cannot catch anything because an 2270 // earlier handler catches a superclass. Need to find a method that is not 2271 // quadratic for this. 2272 // Neither of these are explicitly forbidden, but every compiler detects them 2273 // and warns. 2274 2275 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2276 Handlers, NumHandlers)); 2277} 2278 2279StmtResult 2280Sema::ActOnSEHTryBlock(bool IsCXXTry, 2281 SourceLocation TryLoc, 2282 Stmt *TryBlock, 2283 Stmt *Handler) { 2284 assert(TryBlock && Handler); 2285 2286 getCurFunction()->setHasBranchProtectedScope(); 2287 2288 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2289} 2290 2291StmtResult 2292Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2293 Expr *FilterExpr, 2294 Stmt *Block) { 2295 assert(FilterExpr && Block); 2296 2297 if(!FilterExpr->getType()->isIntegerType()) { 2298 return StmtError(Diag(FilterExpr->getExprLoc(), 2299 diag::err_filter_expression_integral) 2300 << FilterExpr->getType()); 2301 } 2302 2303 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2304} 2305 2306StmtResult 2307Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2308 Stmt *Block) { 2309 assert(Block); 2310 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2311} 2312 2313