SemaStmt.cpp revision bcfd1f55bfbb3e5944cd5e03d07b343e280838c4
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 bool HasLeadingEmptyMacro) { 51 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); 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 // foreach variables are never actually initialized in the way that 75 // the parser came up with. 76 var->setInit(0); 77 78 // In ARC, we don't need to retain the iteration variable of a fast 79 // enumeration loop. Rather than actually trying to catch that 80 // during declaration processing, we remove the consequences here. 81 if (getLangOptions().ObjCAutoRefCount) { 82 QualType type = var->getType(); 83 84 // Only do this if we inferred the lifetime. Inferred lifetime 85 // will show up as a local qualifier because explicit lifetime 86 // should have shown up as an AttributedType instead. 87 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { 88 // Add 'const' and mark the variable as pseudo-strong. 89 var->setType(type.withConst()); 90 var->setARCPseudoStrong(true); 91 } 92 } 93} 94 95/// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. 96/// 97/// Adding a cast to void (or other expression wrappers) will prevent the 98/// warning from firing. 99static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { 100 SourceLocation Loc; 101 bool IsNotEqual, CanAssign; 102 103 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { 104 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) 105 return false; 106 107 Loc = Op->getOperatorLoc(); 108 IsNotEqual = Op->getOpcode() == BO_NE; 109 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); 110 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { 111 if (Op->getOperator() != OO_EqualEqual && 112 Op->getOperator() != OO_ExclaimEqual) 113 return false; 114 115 Loc = Op->getOperatorLoc(); 116 IsNotEqual = Op->getOperator() == OO_ExclaimEqual; 117 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); 118 } else { 119 // Not a typo-prone comparison. 120 return false; 121 } 122 123 // Suppress warnings when the operator, suspicious as it may be, comes from 124 // a macro expansion. 125 if (Loc.isMacroID()) 126 return false; 127 128 S.Diag(Loc, diag::warn_unused_comparison) 129 << (unsigned)IsNotEqual << E->getSourceRange(); 130 131 // If the LHS is a plausible entity to assign to, provide a fixit hint to 132 // correct common typos. 133 if (CanAssign) { 134 if (IsNotEqual) 135 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) 136 << FixItHint::CreateReplacement(Loc, "|="); 137 else 138 S.Diag(Loc, diag::note_equality_comparison_to_assign) 139 << FixItHint::CreateReplacement(Loc, "="); 140 } 141 142 return true; 143} 144 145void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 146 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 147 return DiagnoseUnusedExprResult(Label->getSubStmt()); 148 149 const Expr *E = dyn_cast_or_null<Expr>(S); 150 if (!E) 151 return; 152 153 SourceLocation Loc; 154 SourceRange R1, R2; 155 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context)) 156 return; 157 158 // Okay, we have an unused result. Depending on what the base expression is, 159 // we might want to make a more specific diagnostic. Check for one of these 160 // cases now. 161 unsigned DiagID = diag::warn_unused_expr; 162 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 163 E = Temps->getSubExpr(); 164 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 165 E = TempExpr->getSubExpr(); 166 167 if (DiagnoseUnusedComparison(*this, E)) 168 return; 169 170 E = E->IgnoreParenImpCasts(); 171 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 172 if (E->getType()->isVoidType()) 173 return; 174 175 // If the callee has attribute pure, const, or warn_unused_result, warn with 176 // a more specific message to make it clear what is happening. 177 if (const Decl *FD = CE->getCalleeDecl()) { 178 if (FD->getAttr<WarnUnusedResultAttr>()) { 179 Diag(Loc, diag::warn_unused_result) << R1 << R2; 180 return; 181 } 182 if (FD->getAttr<PureAttr>()) { 183 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 184 return; 185 } 186 if (FD->getAttr<ConstAttr>()) { 187 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 188 return; 189 } 190 } 191 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 192 if (getLangOptions().ObjCAutoRefCount && ME->isDelegateInitCall()) { 193 Diag(Loc, diag::err_arc_unused_init_message) << R1; 194 return; 195 } 196 const ObjCMethodDecl *MD = ME->getMethodDecl(); 197 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 198 Diag(Loc, diag::warn_unused_result) << R1 << R2; 199 return; 200 } 201 } else if (isa<ObjCPropertyRefExpr>(E)) { 202 DiagID = diag::warn_unused_property_expr; 203 } else if (const CXXFunctionalCastExpr *FC 204 = dyn_cast<CXXFunctionalCastExpr>(E)) { 205 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 206 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 207 return; 208 } 209 // Diagnose "(void*) blah" as a typo for "(void) blah". 210 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 211 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 212 QualType T = TI->getType(); 213 214 // We really do want to use the non-canonical type here. 215 if (T == Context.VoidPtrTy) { 216 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 217 218 Diag(Loc, diag::warn_unused_voidptr) 219 << FixItHint::CreateRemoval(TL.getStarLoc()); 220 return; 221 } 222 } 223 224 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 225} 226 227StmtResult 228Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 229 MultiStmtArg elts, bool isStmtExpr) { 230 unsigned NumElts = elts.size(); 231 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 232 // If we're in C89 mode, check that we don't have any decls after stmts. If 233 // so, emit an extension diagnostic. 234 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 235 // Note that __extension__ can be around a decl. 236 unsigned i = 0; 237 // Skip over all declarations. 238 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 239 /*empty*/; 240 241 // We found the end of the list or a statement. Scan for another declstmt. 242 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 243 /*empty*/; 244 245 if (i != NumElts) { 246 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 247 Diag(D->getLocation(), diag::ext_mixed_decls_code); 248 } 249 } 250 // Warn about unused expressions in statements. 251 for (unsigned i = 0; i != NumElts; ++i) { 252 // Ignore statements that are last in a statement expression. 253 if (isStmtExpr && i == NumElts - 1) 254 continue; 255 256 DiagnoseUnusedExprResult(Elts[i]); 257 } 258 259 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 260} 261 262StmtResult 263Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 264 SourceLocation DotDotDotLoc, Expr *RHSVal, 265 SourceLocation ColonLoc) { 266 assert((LHSVal != 0) && "missing expression in case statement"); 267 268 // C99 6.8.4.2p3: The expression shall be an integer constant. 269 // However, GCC allows any evaluatable integer expression. 270 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && 271 VerifyIntegerConstantExpression(LHSVal)) 272 return StmtError(); 273 274 // GCC extension: The expression shall be an integer constant. 275 276 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && 277 VerifyIntegerConstantExpression(RHSVal)) { 278 RHSVal = 0; // Recover by just forgetting about it. 279 } 280 281 if (getCurFunction()->SwitchStack.empty()) { 282 Diag(CaseLoc, diag::err_case_not_in_switch); 283 return StmtError(); 284 } 285 286 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 287 ColonLoc); 288 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 289 return Owned(CS); 290} 291 292/// ActOnCaseStmtBody - This installs a statement as the body of a case. 293void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 294 DiagnoseUnusedExprResult(SubStmt); 295 296 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 297 CS->setSubStmt(SubStmt); 298} 299 300StmtResult 301Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 302 Stmt *SubStmt, Scope *CurScope) { 303 DiagnoseUnusedExprResult(SubStmt); 304 305 if (getCurFunction()->SwitchStack.empty()) { 306 Diag(DefaultLoc, diag::err_default_not_in_switch); 307 return Owned(SubStmt); 308 } 309 310 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 311 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 312 return Owned(DS); 313} 314 315StmtResult 316Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 317 SourceLocation ColonLoc, Stmt *SubStmt) { 318 319 // If the label was multiply defined, reject it now. 320 if (TheDecl->getStmt()) { 321 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 322 Diag(TheDecl->getLocation(), diag::note_previous_definition); 323 return Owned(SubStmt); 324 } 325 326 // Otherwise, things are good. Fill in the declaration and return it. 327 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 328 TheDecl->setStmt(LS); 329 if (!TheDecl->isGnuLocal()) 330 TheDecl->setLocation(IdentLoc); 331 return Owned(LS); 332} 333 334StmtResult 335Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 336 Stmt *thenStmt, SourceLocation ElseLoc, 337 Stmt *elseStmt) { 338 ExprResult CondResult(CondVal.release()); 339 340 VarDecl *ConditionVar = 0; 341 if (CondVar) { 342 ConditionVar = cast<VarDecl>(CondVar); 343 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 344 if (CondResult.isInvalid()) 345 return StmtError(); 346 } 347 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 348 if (!ConditionExpr) 349 return StmtError(); 350 351 DiagnoseUnusedExprResult(thenStmt); 352 353 // Warn if the if block has a null body without an else value. 354 // this helps prevent bugs due to typos, such as 355 // if (condition); 356 // do_stuff(); 357 // 358 if (!elseStmt) { 359 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 360 // But do not warn if the body is a macro that expands to nothing, e.g: 361 // 362 // #define CALL(x) 363 // if (condition) 364 // CALL(0); 365 // 366 if (!stmt->hasLeadingEmptyMacro()) 367 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 368 } 369 370 DiagnoseUnusedExprResult(elseStmt); 371 372 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 373 thenStmt, ElseLoc, elseStmt)); 374} 375 376/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 377/// the specified width and sign. If an overflow occurs, detect it and emit 378/// the specified diagnostic. 379void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 380 unsigned NewWidth, bool NewSign, 381 SourceLocation Loc, 382 unsigned DiagID) { 383 // Perform a conversion to the promoted condition type if needed. 384 if (NewWidth > Val.getBitWidth()) { 385 // If this is an extension, just do it. 386 Val = Val.extend(NewWidth); 387 Val.setIsSigned(NewSign); 388 389 // If the input was signed and negative and the output is 390 // unsigned, don't bother to warn: this is implementation-defined 391 // behavior. 392 // FIXME: Introduce a second, default-ignored warning for this case? 393 } else if (NewWidth < Val.getBitWidth()) { 394 // If this is a truncation, check for overflow. 395 llvm::APSInt ConvVal(Val); 396 ConvVal = ConvVal.trunc(NewWidth); 397 ConvVal.setIsSigned(NewSign); 398 ConvVal = ConvVal.extend(Val.getBitWidth()); 399 ConvVal.setIsSigned(Val.isSigned()); 400 if (ConvVal != Val) 401 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 402 403 // Regardless of whether a diagnostic was emitted, really do the 404 // truncation. 405 Val = Val.trunc(NewWidth); 406 Val.setIsSigned(NewSign); 407 } else if (NewSign != Val.isSigned()) { 408 // Convert the sign to match the sign of the condition. This can cause 409 // overflow as well: unsigned(INTMIN) 410 // We don't diagnose this overflow, because it is implementation-defined 411 // behavior. 412 // FIXME: Introduce a second, default-ignored warning for this case? 413 llvm::APSInt OldVal(Val); 414 Val.setIsSigned(NewSign); 415 } 416} 417 418namespace { 419 struct CaseCompareFunctor { 420 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 421 const llvm::APSInt &RHS) { 422 return LHS.first < RHS; 423 } 424 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 425 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 426 return LHS.first < RHS.first; 427 } 428 bool operator()(const llvm::APSInt &LHS, 429 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 430 return LHS < RHS.first; 431 } 432 }; 433} 434 435/// CmpCaseVals - Comparison predicate for sorting case values. 436/// 437static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 438 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 439 if (lhs.first < rhs.first) 440 return true; 441 442 if (lhs.first == rhs.first && 443 lhs.second->getCaseLoc().getRawEncoding() 444 < rhs.second->getCaseLoc().getRawEncoding()) 445 return true; 446 return false; 447} 448 449/// CmpEnumVals - Comparison predicate for sorting enumeration values. 450/// 451static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 452 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 453{ 454 return lhs.first < rhs.first; 455} 456 457/// EqEnumVals - Comparison preficate for uniqing enumeration values. 458/// 459static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 460 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 461{ 462 return lhs.first == rhs.first; 463} 464 465/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 466/// potentially integral-promoted expression @p expr. 467static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 468 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 469 expr = cleanups->getSubExpr(); 470 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 471 if (impcast->getCastKind() != CK_IntegralCast) break; 472 expr = impcast->getSubExpr(); 473 } 474 return expr->getType(); 475} 476 477StmtResult 478Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 479 Decl *CondVar) { 480 ExprResult CondResult; 481 482 VarDecl *ConditionVar = 0; 483 if (CondVar) { 484 ConditionVar = cast<VarDecl>(CondVar); 485 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 486 if (CondResult.isInvalid()) 487 return StmtError(); 488 489 Cond = CondResult.release(); 490 } 491 492 if (!Cond) 493 return StmtError(); 494 495 CondResult 496 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, 497 PDiag(diag::err_typecheck_statement_requires_integer), 498 PDiag(diag::err_switch_incomplete_class_type) 499 << Cond->getSourceRange(), 500 PDiag(diag::err_switch_explicit_conversion), 501 PDiag(diag::note_switch_conversion), 502 PDiag(diag::err_switch_multiple_conversions), 503 PDiag(diag::note_switch_conversion), 504 PDiag(0)); 505 if (CondResult.isInvalid()) return StmtError(); 506 Cond = CondResult.take(); 507 508 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 509 CondResult = UsualUnaryConversions(Cond); 510 if (CondResult.isInvalid()) return StmtError(); 511 Cond = CondResult.take(); 512 513 if (!CondVar) { 514 CheckImplicitConversions(Cond, SwitchLoc); 515 CondResult = MaybeCreateExprWithCleanups(Cond); 516 if (CondResult.isInvalid()) 517 return StmtError(); 518 Cond = CondResult.take(); 519 } 520 521 getCurFunction()->setHasBranchIntoScope(); 522 523 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 524 getCurFunction()->SwitchStack.push_back(SS); 525 return Owned(SS); 526} 527 528static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 529 if (Val.getBitWidth() < BitWidth) 530 Val = Val.extend(BitWidth); 531 else if (Val.getBitWidth() > BitWidth) 532 Val = Val.trunc(BitWidth); 533 Val.setIsSigned(IsSigned); 534} 535 536StmtResult 537Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 538 Stmt *BodyStmt) { 539 SwitchStmt *SS = cast<SwitchStmt>(Switch); 540 assert(SS == getCurFunction()->SwitchStack.back() && 541 "switch stack missing push/pop!"); 542 543 SS->setBody(BodyStmt, SwitchLoc); 544 getCurFunction()->SwitchStack.pop_back(); 545 546 Expr *CondExpr = SS->getCond(); 547 if (!CondExpr) return StmtError(); 548 549 QualType CondType = CondExpr->getType(); 550 551 Expr *CondExprBeforePromotion = CondExpr; 552 QualType CondTypeBeforePromotion = 553 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 554 555 // C++ 6.4.2.p2: 556 // Integral promotions are performed (on the switch condition). 557 // 558 // A case value unrepresentable by the original switch condition 559 // type (before the promotion) doesn't make sense, even when it can 560 // be represented by the promoted type. Therefore we need to find 561 // the pre-promotion type of the switch condition. 562 if (!CondExpr->isTypeDependent()) { 563 // We have already converted the expression to an integral or enumeration 564 // type, when we started the switch statement. If we don't have an 565 // appropriate type now, just return an error. 566 if (!CondType->isIntegralOrEnumerationType()) 567 return StmtError(); 568 569 if (CondExpr->isKnownToHaveBooleanValue()) { 570 // switch(bool_expr) {...} is often a programmer error, e.g. 571 // switch(n && mask) { ... } // Doh - should be "n & mask". 572 // One can always use an if statement instead of switch(bool_expr). 573 Diag(SwitchLoc, diag::warn_bool_switch_condition) 574 << CondExpr->getSourceRange(); 575 } 576 } 577 578 // Get the bitwidth of the switched-on value before promotions. We must 579 // convert the integer case values to this width before comparison. 580 bool HasDependentValue 581 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 582 unsigned CondWidth 583 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 584 bool CondIsSigned 585 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 586 587 // Accumulate all of the case values in a vector so that we can sort them 588 // and detect duplicates. This vector contains the APInt for the case after 589 // it has been converted to the condition type. 590 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 591 CaseValsTy CaseVals; 592 593 // Keep track of any GNU case ranges we see. The APSInt is the low value. 594 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 595 CaseRangesTy CaseRanges; 596 597 DefaultStmt *TheDefaultStmt = 0; 598 599 bool CaseListIsErroneous = false; 600 601 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 602 SC = SC->getNextSwitchCase()) { 603 604 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 605 if (TheDefaultStmt) { 606 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 607 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 608 609 // FIXME: Remove the default statement from the switch block so that 610 // we'll return a valid AST. This requires recursing down the AST and 611 // finding it, not something we are set up to do right now. For now, 612 // just lop the entire switch stmt out of the AST. 613 CaseListIsErroneous = true; 614 } 615 TheDefaultStmt = DS; 616 617 } else { 618 CaseStmt *CS = cast<CaseStmt>(SC); 619 620 // We already verified that the expression has a i-c-e value (C99 621 // 6.8.4.2p3) - get that value now. 622 Expr *Lo = CS->getLHS(); 623 624 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 625 HasDependentValue = true; 626 break; 627 } 628 629 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 630 631 // Convert the value to the same width/sign as the condition. 632 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 633 Lo->getLocStart(), 634 diag::warn_case_value_overflow); 635 636 // If the LHS is not the same type as the condition, insert an implicit 637 // cast. 638 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 639 CS->setLHS(Lo); 640 641 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 642 if (CS->getRHS()) { 643 if (CS->getRHS()->isTypeDependent() || 644 CS->getRHS()->isValueDependent()) { 645 HasDependentValue = true; 646 break; 647 } 648 CaseRanges.push_back(std::make_pair(LoVal, CS)); 649 } else 650 CaseVals.push_back(std::make_pair(LoVal, CS)); 651 } 652 } 653 654 if (!HasDependentValue) { 655 // If we don't have a default statement, check whether the 656 // condition is constant. 657 llvm::APSInt ConstantCondValue; 658 bool HasConstantCond = false; 659 bool ShouldCheckConstantCond = false; 660 if (!HasDependentValue && !TheDefaultStmt) { 661 Expr::EvalResult Result; 662 HasConstantCond = CondExprBeforePromotion->Evaluate(Result, Context); 663 if (HasConstantCond) { 664 assert(Result.Val.isInt() && "switch condition evaluated to non-int"); 665 ConstantCondValue = Result.Val.getInt(); 666 ShouldCheckConstantCond = true; 667 668 assert(ConstantCondValue.getBitWidth() == CondWidth && 669 ConstantCondValue.isSigned() == CondIsSigned); 670 } 671 } 672 673 // Sort all the scalar case values so we can easily detect duplicates. 674 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 675 676 if (!CaseVals.empty()) { 677 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 678 if (ShouldCheckConstantCond && 679 CaseVals[i].first == ConstantCondValue) 680 ShouldCheckConstantCond = false; 681 682 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 683 // If we have a duplicate, report it. 684 Diag(CaseVals[i].second->getLHS()->getLocStart(), 685 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 686 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 687 diag::note_duplicate_case_prev); 688 // FIXME: We really want to remove the bogus case stmt from the 689 // substmt, but we have no way to do this right now. 690 CaseListIsErroneous = true; 691 } 692 } 693 } 694 695 // Detect duplicate case ranges, which usually don't exist at all in 696 // the first place. 697 if (!CaseRanges.empty()) { 698 // Sort all the case ranges by their low value so we can easily detect 699 // overlaps between ranges. 700 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 701 702 // Scan the ranges, computing the high values and removing empty ranges. 703 std::vector<llvm::APSInt> HiVals; 704 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 705 llvm::APSInt &LoVal = CaseRanges[i].first; 706 CaseStmt *CR = CaseRanges[i].second; 707 Expr *Hi = CR->getRHS(); 708 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 709 710 // Convert the value to the same width/sign as the condition. 711 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 712 Hi->getLocStart(), 713 diag::warn_case_value_overflow); 714 715 // If the LHS is not the same type as the condition, insert an implicit 716 // cast. 717 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 718 CR->setRHS(Hi); 719 720 // If the low value is bigger than the high value, the case is empty. 721 if (LoVal > HiVal) { 722 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 723 << SourceRange(CR->getLHS()->getLocStart(), 724 Hi->getLocEnd()); 725 CaseRanges.erase(CaseRanges.begin()+i); 726 --i, --e; 727 continue; 728 } 729 730 if (ShouldCheckConstantCond && 731 LoVal <= ConstantCondValue && 732 ConstantCondValue <= HiVal) 733 ShouldCheckConstantCond = false; 734 735 HiVals.push_back(HiVal); 736 } 737 738 // Rescan the ranges, looking for overlap with singleton values and other 739 // ranges. Since the range list is sorted, we only need to compare case 740 // ranges with their neighbors. 741 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 742 llvm::APSInt &CRLo = CaseRanges[i].first; 743 llvm::APSInt &CRHi = HiVals[i]; 744 CaseStmt *CR = CaseRanges[i].second; 745 746 // Check to see whether the case range overlaps with any 747 // singleton cases. 748 CaseStmt *OverlapStmt = 0; 749 llvm::APSInt OverlapVal(32); 750 751 // Find the smallest value >= the lower bound. If I is in the 752 // case range, then we have overlap. 753 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 754 CaseVals.end(), CRLo, 755 CaseCompareFunctor()); 756 if (I != CaseVals.end() && I->first < CRHi) { 757 OverlapVal = I->first; // Found overlap with scalar. 758 OverlapStmt = I->second; 759 } 760 761 // Find the smallest value bigger than the upper bound. 762 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 763 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 764 OverlapVal = (I-1)->first; // Found overlap with scalar. 765 OverlapStmt = (I-1)->second; 766 } 767 768 // Check to see if this case stmt overlaps with the subsequent 769 // case range. 770 if (i && CRLo <= HiVals[i-1]) { 771 OverlapVal = HiVals[i-1]; // Found overlap with range. 772 OverlapStmt = CaseRanges[i-1].second; 773 } 774 775 if (OverlapStmt) { 776 // If we have a duplicate, report it. 777 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 778 << OverlapVal.toString(10); 779 Diag(OverlapStmt->getLHS()->getLocStart(), 780 diag::note_duplicate_case_prev); 781 // FIXME: We really want to remove the bogus case stmt from the 782 // substmt, but we have no way to do this right now. 783 CaseListIsErroneous = true; 784 } 785 } 786 } 787 788 // Complain if we have a constant condition and we didn't find a match. 789 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 790 // TODO: it would be nice if we printed enums as enums, chars as 791 // chars, etc. 792 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 793 << ConstantCondValue.toString(10) 794 << CondExpr->getSourceRange(); 795 } 796 797 // Check to see if switch is over an Enum and handles all of its 798 // values. We only issue a warning if there is not 'default:', but 799 // we still do the analysis to preserve this information in the AST 800 // (which can be used by flow-based analyes). 801 // 802 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 803 804 // If switch has default case, then ignore it. 805 if (!CaseListIsErroneous && !HasConstantCond && ET) { 806 const EnumDecl *ED = ET->getDecl(); 807 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 808 EnumValsTy; 809 EnumValsTy EnumVals; 810 811 // Gather all enum values, set their type and sort them, 812 // allowing easier comparison with CaseVals. 813 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 814 EDI != ED->enumerator_end(); ++EDI) { 815 llvm::APSInt Val = EDI->getInitVal(); 816 AdjustAPSInt(Val, CondWidth, CondIsSigned); 817 EnumVals.push_back(std::make_pair(Val, *EDI)); 818 } 819 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 820 EnumValsTy::iterator EIend = 821 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 822 823 // See which case values aren't in enum. 824 // TODO: we might want to check whether case values are out of the 825 // enum even if we don't want to check whether all cases are handled. 826 if (!TheDefaultStmt) { 827 EnumValsTy::const_iterator EI = EnumVals.begin(); 828 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 829 CI != CaseVals.end(); CI++) { 830 while (EI != EIend && EI->first < CI->first) 831 EI++; 832 if (EI == EIend || EI->first > CI->first) 833 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 834 << ED->getDeclName(); 835 } 836 // See which of case ranges aren't in enum 837 EI = EnumVals.begin(); 838 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 839 RI != CaseRanges.end() && EI != EIend; RI++) { 840 while (EI != EIend && EI->first < RI->first) 841 EI++; 842 843 if (EI == EIend || EI->first != RI->first) { 844 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 845 << ED->getDeclName(); 846 } 847 848 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 849 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 850 while (EI != EIend && EI->first < Hi) 851 EI++; 852 if (EI == EIend || EI->first != Hi) 853 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 854 << ED->getDeclName(); 855 } 856 } 857 858 // Check which enum vals aren't in switch 859 CaseValsTy::const_iterator CI = CaseVals.begin(); 860 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 861 bool hasCasesNotInSwitch = false; 862 863 SmallVector<DeclarationName,8> UnhandledNames; 864 865 for (EnumValsTy::const_iterator EI = EnumVals.begin(); EI != EIend; EI++){ 866 // Drop unneeded case values 867 llvm::APSInt CIVal; 868 while (CI != CaseVals.end() && CI->first < EI->first) 869 CI++; 870 871 if (CI != CaseVals.end() && CI->first == EI->first) 872 continue; 873 874 // Drop unneeded case ranges 875 for (; RI != CaseRanges.end(); RI++) { 876 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context); 877 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 878 if (EI->first <= Hi) 879 break; 880 } 881 882 if (RI == CaseRanges.end() || EI->first < RI->first) { 883 hasCasesNotInSwitch = true; 884 if (!TheDefaultStmt) 885 UnhandledNames.push_back(EI->second->getDeclName()); 886 } 887 } 888 889 // Produce a nice diagnostic if multiple values aren't handled. 890 switch (UnhandledNames.size()) { 891 case 0: break; 892 case 1: 893 Diag(CondExpr->getExprLoc(), diag::warn_missing_case1) 894 << UnhandledNames[0]; 895 break; 896 case 2: 897 Diag(CondExpr->getExprLoc(), diag::warn_missing_case2) 898 << UnhandledNames[0] << UnhandledNames[1]; 899 break; 900 case 3: 901 Diag(CondExpr->getExprLoc(), diag::warn_missing_case3) 902 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 903 break; 904 default: 905 Diag(CondExpr->getExprLoc(), diag::warn_missing_cases) 906 << (unsigned)UnhandledNames.size() 907 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 908 break; 909 } 910 911 if (!hasCasesNotInSwitch) 912 SS->setAllEnumCasesCovered(); 913 } 914 } 915 916 // FIXME: If the case list was broken is some way, we don't have a good system 917 // to patch it up. Instead, just return the whole substmt as broken. 918 if (CaseListIsErroneous) 919 return StmtError(); 920 921 return Owned(SS); 922} 923 924StmtResult 925Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 926 Decl *CondVar, Stmt *Body) { 927 ExprResult CondResult(Cond.release()); 928 929 VarDecl *ConditionVar = 0; 930 if (CondVar) { 931 ConditionVar = cast<VarDecl>(CondVar); 932 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 933 if (CondResult.isInvalid()) 934 return StmtError(); 935 } 936 Expr *ConditionExpr = CondResult.take(); 937 if (!ConditionExpr) 938 return StmtError(); 939 940 DiagnoseUnusedExprResult(Body); 941 942 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 943 Body, WhileLoc)); 944} 945 946StmtResult 947Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 948 SourceLocation WhileLoc, SourceLocation CondLParen, 949 Expr *Cond, SourceLocation CondRParen) { 950 assert(Cond && "ActOnDoStmt(): missing expression"); 951 952 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 953 if (CondResult.isInvalid() || CondResult.isInvalid()) 954 return StmtError(); 955 Cond = CondResult.take(); 956 957 CheckImplicitConversions(Cond, DoLoc); 958 CondResult = MaybeCreateExprWithCleanups(Cond); 959 if (CondResult.isInvalid()) 960 return StmtError(); 961 Cond = CondResult.take(); 962 963 DiagnoseUnusedExprResult(Body); 964 965 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 966} 967 968StmtResult 969Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 970 Stmt *First, FullExprArg second, Decl *secondVar, 971 FullExprArg third, 972 SourceLocation RParenLoc, Stmt *Body) { 973 if (!getLangOptions().CPlusPlus) { 974 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 975 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 976 // declare identifiers for objects having storage class 'auto' or 977 // 'register'. 978 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 979 DI!=DE; ++DI) { 980 VarDecl *VD = dyn_cast<VarDecl>(*DI); 981 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 982 VD = 0; 983 if (VD == 0) 984 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 985 // FIXME: mark decl erroneous! 986 } 987 } 988 } 989 990 ExprResult SecondResult(second.release()); 991 VarDecl *ConditionVar = 0; 992 if (secondVar) { 993 ConditionVar = cast<VarDecl>(secondVar); 994 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 995 if (SecondResult.isInvalid()) 996 return StmtError(); 997 } 998 999 Expr *Third = third.release().takeAs<Expr>(); 1000 1001 DiagnoseUnusedExprResult(First); 1002 DiagnoseUnusedExprResult(Third); 1003 DiagnoseUnusedExprResult(Body); 1004 1005 return Owned(new (Context) ForStmt(Context, First, 1006 SecondResult.take(), ConditionVar, 1007 Third, Body, ForLoc, LParenLoc, 1008 RParenLoc)); 1009} 1010 1011/// In an Objective C collection iteration statement: 1012/// for (x in y) 1013/// x can be an arbitrary l-value expression. Bind it up as a 1014/// full-expression. 1015StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1016 CheckImplicitConversions(E); 1017 ExprResult Result = MaybeCreateExprWithCleanups(E); 1018 if (Result.isInvalid()) return StmtError(); 1019 return Owned(static_cast<Stmt*>(Result.get())); 1020} 1021 1022ExprResult 1023Sema::ActOnObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1024 assert(collection); 1025 1026 // Bail out early if we've got a type-dependent expression. 1027 if (collection->isTypeDependent()) return Owned(collection); 1028 1029 // Perform normal l-value conversion. 1030 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1031 if (result.isInvalid()) 1032 return ExprError(); 1033 collection = result.take(); 1034 1035 // The operand needs to have object-pointer type. 1036 // TODO: should we do a contextual conversion? 1037 const ObjCObjectPointerType *pointerType = 1038 collection->getType()->getAs<ObjCObjectPointerType>(); 1039 if (!pointerType) 1040 return Diag(forLoc, diag::err_collection_expr_type) 1041 << collection->getType() << collection->getSourceRange(); 1042 1043 // Check that the operand provides 1044 // - countByEnumeratingWithState:objects:count: 1045 const ObjCObjectType *objectType = pointerType->getObjectType(); 1046 ObjCInterfaceDecl *iface = objectType->getInterface(); 1047 1048 // If we have a forward-declared type, we can't do this check. 1049 if (iface && iface->isForwardDecl()) { 1050 // This is ill-formed under ARC. 1051 if (getLangOptions().ObjCAutoRefCount) { 1052 Diag(forLoc, diag::err_arc_collection_forward) 1053 << pointerType->getPointeeType() << collection->getSourceRange(); 1054 } 1055 1056 // Otherwise, if we have any useful type information, check that 1057 // the type declares the appropriate method. 1058 } else if (iface || !objectType->qual_empty()) { 1059 IdentifierInfo *selectorIdents[] = { 1060 &Context.Idents.get("countByEnumeratingWithState"), 1061 &Context.Idents.get("objects"), 1062 &Context.Idents.get("count") 1063 }; 1064 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1065 1066 ObjCMethodDecl *method = 0; 1067 1068 // If there's an interface, look in both the public and private APIs. 1069 if (iface) { 1070 method = iface->lookupInstanceMethod(selector); 1071 if (!method) method = LookupPrivateInstanceMethod(selector, iface); 1072 } 1073 1074 // Also check protocol qualifiers. 1075 if (!method) 1076 method = LookupMethodInQualifiedType(selector, pointerType, 1077 /*instance*/ true); 1078 1079 // If we didn't find it anywhere, give up. 1080 if (!method) { 1081 Diag(forLoc, diag::warn_collection_expr_type) 1082 << collection->getType() << selector << collection->getSourceRange(); 1083 } 1084 1085 // TODO: check for an incompatible signature? 1086 } 1087 1088 // Wrap up any cleanups in the expression. 1089 return Owned(MaybeCreateExprWithCleanups(collection)); 1090} 1091 1092StmtResult 1093Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1094 SourceLocation LParenLoc, 1095 Stmt *First, Expr *Second, 1096 SourceLocation RParenLoc, Stmt *Body) { 1097 if (First) { 1098 QualType FirstType; 1099 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1100 if (!DS->isSingleDecl()) 1101 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1102 diag::err_toomany_element_decls)); 1103 1104 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1105 FirstType = D->getType(); 1106 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1107 // declare identifiers for objects having storage class 'auto' or 1108 // 'register'. 1109 if (!D->hasLocalStorage()) 1110 return StmtError(Diag(D->getLocation(), 1111 diag::err_non_variable_decl_in_for)); 1112 } else { 1113 Expr *FirstE = cast<Expr>(First); 1114 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1115 return StmtError(Diag(First->getLocStart(), 1116 diag::err_selector_element_not_lvalue) 1117 << First->getSourceRange()); 1118 1119 FirstType = static_cast<Expr*>(First)->getType(); 1120 } 1121 if (!FirstType->isDependentType() && 1122 !FirstType->isObjCObjectPointerType() && 1123 !FirstType->isBlockPointerType()) 1124 Diag(ForLoc, diag::err_selector_element_type) 1125 << FirstType << First->getSourceRange(); 1126 } 1127 1128 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 1129 ForLoc, RParenLoc)); 1130} 1131 1132namespace { 1133 1134enum BeginEndFunction { 1135 BEF_begin, 1136 BEF_end 1137}; 1138 1139/// Build a variable declaration for a for-range statement. 1140static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1141 QualType Type, const char *Name) { 1142 DeclContext *DC = SemaRef.CurContext; 1143 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1144 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1145 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1146 TInfo, SC_Auto, SC_None); 1147 Decl->setImplicit(); 1148 return Decl; 1149} 1150 1151/// Finish building a variable declaration for a for-range statement. 1152/// \return true if an error occurs. 1153static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1154 SourceLocation Loc, int diag) { 1155 // Deduce the type for the iterator variable now rather than leaving it to 1156 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1157 TypeSourceInfo *InitTSI = 0; 1158 if (Init->getType()->isVoidType() || 1159 !SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI)) 1160 SemaRef.Diag(Loc, diag) << Init->getType(); 1161 if (!InitTSI) { 1162 Decl->setInvalidDecl(); 1163 return true; 1164 } 1165 Decl->setTypeSourceInfo(InitTSI); 1166 Decl->setType(InitTSI->getType()); 1167 1168 // In ARC, infer lifetime. 1169 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1170 // we're doing the equivalent of fast iteration. 1171 if (SemaRef.getLangOptions().ObjCAutoRefCount && 1172 SemaRef.inferObjCARCLifetime(Decl)) 1173 Decl->setInvalidDecl(); 1174 1175 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1176 /*TypeMayContainAuto=*/false); 1177 SemaRef.FinalizeDeclaration(Decl); 1178 SemaRef.CurContext->addHiddenDecl(Decl); 1179 return false; 1180} 1181 1182/// Produce a note indicating which begin/end function was implicitly called 1183/// by a C++0x for-range statement. This is often not obvious from the code, 1184/// nor from the diagnostics produced when analysing the implicit expressions 1185/// required in a for-range statement. 1186void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1187 BeginEndFunction BEF) { 1188 CallExpr *CE = dyn_cast<CallExpr>(E); 1189 if (!CE) 1190 return; 1191 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1192 if (!D) 1193 return; 1194 SourceLocation Loc = D->getLocation(); 1195 1196 std::string Description; 1197 bool IsTemplate = false; 1198 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1199 Description = SemaRef.getTemplateArgumentBindingsText( 1200 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1201 IsTemplate = true; 1202 } 1203 1204 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1205 << BEF << IsTemplate << Description << E->getType(); 1206} 1207 1208/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1209/// given LookupResult is non-empty, it is assumed to describe a member which 1210/// will be invoked. Otherwise, the function will be found via argument 1211/// dependent lookup. 1212static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1213 SourceLocation Loc, 1214 VarDecl *Decl, 1215 BeginEndFunction BEF, 1216 const DeclarationNameInfo &NameInfo, 1217 LookupResult &MemberLookup, 1218 Expr *Range) { 1219 ExprResult CallExpr; 1220 if (!MemberLookup.empty()) { 1221 ExprResult MemberRef = 1222 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1223 /*IsPtr=*/false, CXXScopeSpec(), 1224 /*Qualifier=*/0, MemberLookup, 1225 /*TemplateArgs=*/0); 1226 if (MemberRef.isInvalid()) 1227 return ExprError(); 1228 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1229 Loc, 0); 1230 if (CallExpr.isInvalid()) 1231 return ExprError(); 1232 } else { 1233 UnresolvedSet<0> FoundNames; 1234 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1235 // std is an associated namespace. 1236 UnresolvedLookupExpr *Fn = 1237 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1238 NestedNameSpecifierLoc(), NameInfo, 1239 /*NeedsADL=*/true, /*Overloaded=*/false, 1240 FoundNames.begin(), FoundNames.end(), 1241 /*LookInStdNamespace=*/true); 1242 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1243 0); 1244 if (CallExpr.isInvalid()) { 1245 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1246 << Range->getType(); 1247 return ExprError(); 1248 } 1249 } 1250 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1251 diag::err_for_range_iter_deduction_failure)) { 1252 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1253 return ExprError(); 1254 } 1255 return CallExpr; 1256} 1257 1258} 1259 1260/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1261/// 1262/// C++0x [stmt.ranged]: 1263/// A range-based for statement is equivalent to 1264/// 1265/// { 1266/// auto && __range = range-init; 1267/// for ( auto __begin = begin-expr, 1268/// __end = end-expr; 1269/// __begin != __end; 1270/// ++__begin ) { 1271/// for-range-declaration = *__begin; 1272/// statement 1273/// } 1274/// } 1275/// 1276/// The body of the loop is not available yet, since it cannot be analysed until 1277/// we have determined the type of the for-range-declaration. 1278StmtResult 1279Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1280 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1281 SourceLocation RParenLoc) { 1282 if (!First || !Range) 1283 return StmtError(); 1284 1285 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1286 assert(DS && "first part of for range not a decl stmt"); 1287 1288 if (!DS->isSingleDecl()) { 1289 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1290 return StmtError(); 1291 } 1292 if (DS->getSingleDecl()->isInvalidDecl()) 1293 return StmtError(); 1294 1295 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1296 return StmtError(); 1297 1298 // Build auto && __range = range-init 1299 SourceLocation RangeLoc = Range->getLocStart(); 1300 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1301 Context.getAutoRRefDeductType(), 1302 "__range"); 1303 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1304 diag::err_for_range_deduction_failure)) 1305 return StmtError(); 1306 1307 // Claim the type doesn't contain auto: we've already done the checking. 1308 DeclGroupPtrTy RangeGroup = 1309 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1310 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1311 if (RangeDecl.isInvalid()) 1312 return StmtError(); 1313 1314 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1315 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1316 RParenLoc); 1317} 1318 1319/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1320StmtResult 1321Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1322 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1323 Expr *Inc, Stmt *LoopVarDecl, 1324 SourceLocation RParenLoc) { 1325 Scope *S = getCurScope(); 1326 1327 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1328 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1329 QualType RangeVarType = RangeVar->getType(); 1330 1331 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1332 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1333 1334 StmtResult BeginEndDecl = BeginEnd; 1335 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1336 1337 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1338 SourceLocation RangeLoc = RangeVar->getLocation(); 1339 1340 ExprResult RangeRef = BuildDeclRefExpr(RangeVar, 1341 RangeVarType.getNonReferenceType(), 1342 VK_LValue, ColonLoc); 1343 if (RangeRef.isInvalid()) 1344 return StmtError(); 1345 1346 QualType AutoType = Context.getAutoDeductType(); 1347 Expr *Range = RangeVar->getInit(); 1348 if (!Range) 1349 return StmtError(); 1350 QualType RangeType = Range->getType(); 1351 1352 if (RequireCompleteType(RangeLoc, RangeType, 1353 PDiag(diag::err_for_range_incomplete_type))) 1354 return StmtError(); 1355 1356 // Build auto __begin = begin-expr, __end = end-expr. 1357 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1358 "__begin"); 1359 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1360 "__end"); 1361 1362 // Build begin-expr and end-expr and attach to __begin and __end variables. 1363 ExprResult BeginExpr, EndExpr; 1364 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1365 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1366 // __range + __bound, respectively, where __bound is the array bound. If 1367 // _RangeT is an array of unknown size or an array of incomplete type, 1368 // the program is ill-formed; 1369 1370 // begin-expr is __range. 1371 BeginExpr = RangeRef; 1372 if (FinishForRangeVarDecl(*this, BeginVar, RangeRef.get(), ColonLoc, 1373 diag::err_for_range_iter_deduction_failure)) { 1374 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1375 return StmtError(); 1376 } 1377 1378 // Find the array bound. 1379 ExprResult BoundExpr; 1380 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1381 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1382 Context.getPointerDiffType(), 1383 RangeLoc)); 1384 else if (const VariableArrayType *VAT = 1385 dyn_cast<VariableArrayType>(UnqAT)) 1386 BoundExpr = VAT->getSizeExpr(); 1387 else { 1388 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1389 // UnqAT is not incomplete and Range is not type-dependent. 1390 assert(0 && "Unexpected array type in for-range"); 1391 return StmtError(); 1392 } 1393 1394 // end-expr is __range + __bound. 1395 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, RangeRef.get(), 1396 BoundExpr.get()); 1397 if (EndExpr.isInvalid()) 1398 return StmtError(); 1399 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1400 diag::err_for_range_iter_deduction_failure)) { 1401 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1402 return StmtError(); 1403 } 1404 } else { 1405 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1406 ColonLoc); 1407 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1408 ColonLoc); 1409 1410 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1411 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1412 1413 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1414 // - if _RangeT is a class type, the unqualified-ids begin and end are 1415 // looked up in the scope of class _RangeT as if by class member access 1416 // lookup (3.4.5), and if either (or both) finds at least one 1417 // declaration, begin-expr and end-expr are __range.begin() and 1418 // __range.end(), respectively; 1419 LookupQualifiedName(BeginMemberLookup, D); 1420 LookupQualifiedName(EndMemberLookup, D); 1421 1422 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1423 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1424 << RangeType << BeginMemberLookup.empty(); 1425 return StmtError(); 1426 } 1427 } else { 1428 // - otherwise, begin-expr and end-expr are begin(__range) and 1429 // end(__range), respectively, where begin and end are looked up with 1430 // argument-dependent lookup (3.4.2). For the purposes of this name 1431 // lookup, namespace std is an associated namespace. 1432 } 1433 1434 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1435 BEF_begin, BeginNameInfo, 1436 BeginMemberLookup, RangeRef.get()); 1437 if (BeginExpr.isInvalid()) 1438 return StmtError(); 1439 1440 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1441 BEF_end, EndNameInfo, 1442 EndMemberLookup, RangeRef.get()); 1443 if (EndExpr.isInvalid()) 1444 return StmtError(); 1445 } 1446 1447 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1448 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1449 if (!Context.hasSameType(BeginType, EndType)) { 1450 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1451 << BeginType << EndType; 1452 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1453 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1454 } 1455 1456 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1457 // Claim the type doesn't contain auto: we've already done the checking. 1458 DeclGroupPtrTy BeginEndGroup = 1459 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1460 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1461 1462 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, 1463 BeginType.getNonReferenceType(), 1464 VK_LValue, ColonLoc); 1465 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1466 VK_LValue, ColonLoc); 1467 1468 // Build and check __begin != __end expression. 1469 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1470 BeginRef.get(), EndRef.get()); 1471 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1472 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1473 if (NotEqExpr.isInvalid()) { 1474 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1475 if (!Context.hasSameType(BeginType, EndType)) 1476 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1477 return StmtError(); 1478 } 1479 1480 // Build and check ++__begin expression. 1481 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1482 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1483 if (IncrExpr.isInvalid()) { 1484 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1485 return StmtError(); 1486 } 1487 1488 // Build and check *__begin expression. 1489 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1490 if (DerefExpr.isInvalid()) { 1491 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1492 return StmtError(); 1493 } 1494 1495 // Attach *__begin as initializer for VD. 1496 if (!LoopVar->isInvalidDecl()) { 1497 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1498 /*TypeMayContainAuto=*/true); 1499 if (LoopVar->isInvalidDecl()) 1500 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1501 } 1502 } else { 1503 // The range is implicitly used as a placeholder when it is dependent. 1504 RangeVar->setUsed(); 1505 } 1506 1507 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1508 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1509 NotEqExpr.take(), IncrExpr.take(), 1510 LoopVarDS, /*Body=*/0, ForLoc, 1511 ColonLoc, RParenLoc)); 1512} 1513 1514/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1515/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1516/// body cannot be performed until after the type of the range variable is 1517/// determined. 1518StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1519 if (!S || !B) 1520 return StmtError(); 1521 1522 cast<CXXForRangeStmt>(S)->setBody(B); 1523 return S; 1524} 1525 1526StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1527 SourceLocation LabelLoc, 1528 LabelDecl *TheDecl) { 1529 getCurFunction()->setHasBranchIntoScope(); 1530 TheDecl->setUsed(); 1531 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1532} 1533 1534StmtResult 1535Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1536 Expr *E) { 1537 // Convert operand to void* 1538 if (!E->isTypeDependent()) { 1539 QualType ETy = E->getType(); 1540 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1541 ExprResult ExprRes = Owned(E); 1542 AssignConvertType ConvTy = 1543 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1544 if (ExprRes.isInvalid()) 1545 return StmtError(); 1546 E = ExprRes.take(); 1547 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1548 return StmtError(); 1549 } 1550 1551 getCurFunction()->setHasIndirectGoto(); 1552 1553 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1554} 1555 1556StmtResult 1557Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1558 Scope *S = CurScope->getContinueParent(); 1559 if (!S) { 1560 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1561 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1562 } 1563 1564 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1565} 1566 1567StmtResult 1568Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1569 Scope *S = CurScope->getBreakParent(); 1570 if (!S) { 1571 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1572 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1573 } 1574 1575 return Owned(new (Context) BreakStmt(BreakLoc)); 1576} 1577 1578/// \brief Determine whether the given expression is a candidate for 1579/// copy elision in either a return statement or a throw expression. 1580/// 1581/// \param ReturnType If we're determining the copy elision candidate for 1582/// a return statement, this is the return type of the function. If we're 1583/// determining the copy elision candidate for a throw expression, this will 1584/// be a NULL type. 1585/// 1586/// \param E The expression being returned from the function or block, or 1587/// being thrown. 1588/// 1589/// \param AllowFunctionParameter Whether we allow function parameters to 1590/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1591/// we re-use this logic to determine whether we should try to move as part of 1592/// a return or throw (which does allow function parameters). 1593/// 1594/// \returns The NRVO candidate variable, if the return statement may use the 1595/// NRVO, or NULL if there is no such candidate. 1596const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1597 Expr *E, 1598 bool AllowFunctionParameter) { 1599 QualType ExprType = E->getType(); 1600 // - in a return statement in a function with ... 1601 // ... a class return type ... 1602 if (!ReturnType.isNull()) { 1603 if (!ReturnType->isRecordType()) 1604 return 0; 1605 // ... the same cv-unqualified type as the function return type ... 1606 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1607 return 0; 1608 } 1609 1610 // ... the expression is the name of a non-volatile automatic object 1611 // (other than a function or catch-clause parameter)) ... 1612 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1613 if (!DR) 1614 return 0; 1615 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1616 if (!VD) 1617 return 0; 1618 1619 if (VD->hasLocalStorage() && !VD->isExceptionVariable() && 1620 !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() && 1621 !VD->getType().isVolatileQualified() && 1622 ((VD->getKind() == Decl::Var) || 1623 (AllowFunctionParameter && VD->getKind() == Decl::ParmVar))) 1624 return VD; 1625 1626 return 0; 1627} 1628 1629/// \brief Perform the initialization of a potentially-movable value, which 1630/// is the result of return value. 1631/// 1632/// This routine implements C++0x [class.copy]p33, which attempts to treat 1633/// returned lvalues as rvalues in certain cases (to prefer move construction), 1634/// then falls back to treating them as lvalues if that failed. 1635ExprResult 1636Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1637 const VarDecl *NRVOCandidate, 1638 QualType ResultType, 1639 Expr *Value, 1640 bool AllowNRVO) { 1641 // C++0x [class.copy]p33: 1642 // When the criteria for elision of a copy operation are met or would 1643 // be met save for the fact that the source object is a function 1644 // parameter, and the object to be copied is designated by an lvalue, 1645 // overload resolution to select the constructor for the copy is first 1646 // performed as if the object were designated by an rvalue. 1647 ExprResult Res = ExprError(); 1648 if (AllowNRVO && 1649 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 1650 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1651 Value->getType(), CK_LValueToRValue, 1652 Value, VK_XValue); 1653 1654 Expr *InitExpr = &AsRvalue; 1655 InitializationKind Kind 1656 = InitializationKind::CreateCopy(Value->getLocStart(), 1657 Value->getLocStart()); 1658 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 1659 1660 // [...] If overload resolution fails, or if the type of the first 1661 // parameter of the selected constructor is not an rvalue reference 1662 // to the object's type (possibly cv-qualified), overload resolution 1663 // is performed again, considering the object as an lvalue. 1664 if (Seq) { 1665 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 1666 StepEnd = Seq.step_end(); 1667 Step != StepEnd; ++Step) { 1668 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 1669 continue; 1670 1671 CXXConstructorDecl *Constructor 1672 = cast<CXXConstructorDecl>(Step->Function.Function); 1673 1674 const RValueReferenceType *RRefType 1675 = Constructor->getParamDecl(0)->getType() 1676 ->getAs<RValueReferenceType>(); 1677 1678 // If we don't meet the criteria, break out now. 1679 if (!RRefType || 1680 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 1681 Context.getTypeDeclType(Constructor->getParent()))) 1682 break; 1683 1684 // Promote "AsRvalue" to the heap, since we now need this 1685 // expression node to persist. 1686 Value = ImplicitCastExpr::Create(Context, Value->getType(), 1687 CK_LValueToRValue, Value, 0, 1688 VK_XValue); 1689 1690 // Complete type-checking the initialization of the return type 1691 // using the constructor we found. 1692 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 1693 } 1694 } 1695 } 1696 1697 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 1698 // above, or overload resolution failed. Either way, we need to try 1699 // (again) now with the return value expression as written. 1700 if (Res.isInvalid()) 1701 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 1702 1703 return Res; 1704} 1705 1706/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 1707/// 1708StmtResult 1709Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1710 // If this is the first return we've seen in the block, infer the type of 1711 // the block from it. 1712 BlockScopeInfo *CurBlock = getCurBlock(); 1713 if (CurBlock->ReturnType.isNull()) { 1714 if (RetValExp) { 1715 // Don't call UsualUnaryConversions(), since we don't want to do 1716 // integer promotions here. 1717 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 1718 if (Result.isInvalid()) 1719 return StmtError(); 1720 RetValExp = Result.take(); 1721 1722 if (!RetValExp->isTypeDependent()) { 1723 CurBlock->ReturnType = RetValExp->getType(); 1724 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) { 1725 // We have to remove a 'const' added to copied-in variable which was 1726 // part of the implementation spec. and not the actual qualifier for 1727 // the variable. 1728 if (CDRE->isConstQualAdded()) 1729 CurBlock->ReturnType.removeLocalConst(); // FIXME: local??? 1730 } 1731 } else 1732 CurBlock->ReturnType = Context.DependentTy; 1733 } else 1734 CurBlock->ReturnType = Context.VoidTy; 1735 } 1736 QualType FnRetType = CurBlock->ReturnType; 1737 1738 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 1739 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 1740 << getCurFunctionOrMethodDecl()->getDeclName(); 1741 return StmtError(); 1742 } 1743 1744 // Otherwise, verify that this result type matches the previous one. We are 1745 // pickier with blocks than for normal functions because we don't have GCC 1746 // compatibility to worry about here. 1747 const VarDecl *NRVOCandidate = 0; 1748 if (FnRetType->isDependentType()) { 1749 // Delay processing for now. TODO: there are lots of dependent 1750 // types we can conclusively prove aren't void. 1751 } else if (FnRetType->isVoidType()) { 1752 if (RetValExp && 1753 !(getLangOptions().CPlusPlus && 1754 (RetValExp->isTypeDependent() || 1755 RetValExp->getType()->isVoidType()))) { 1756 Diag(ReturnLoc, diag::err_return_block_has_expr); 1757 RetValExp = 0; 1758 } 1759 } else if (!RetValExp) { 1760 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 1761 } else if (!RetValExp->isTypeDependent()) { 1762 // we have a non-void block with an expression, continue checking 1763 1764 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1765 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1766 // function return. 1767 1768 // In C++ the return statement is handled via a copy initialization. 1769 // the C version of which boils down to CheckSingleAssignmentConstraints. 1770 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1771 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1772 FnRetType, 1773 NRVOCandidate != 0); 1774 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1775 FnRetType, RetValExp); 1776 if (Res.isInvalid()) { 1777 // FIXME: Cleanup temporaries here, anyway? 1778 return StmtError(); 1779 } 1780 RetValExp = Res.take(); 1781 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1782 } 1783 1784 if (RetValExp) { 1785 CheckImplicitConversions(RetValExp, ReturnLoc); 1786 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1787 } 1788 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 1789 NRVOCandidate); 1790 1791 // If we need to check for the named return value optimization, save the 1792 // return statement in our scope for later processing. 1793 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1794 !CurContext->isDependentContext()) 1795 FunctionScopes.back()->Returns.push_back(Result); 1796 1797 return Owned(Result); 1798} 1799 1800StmtResult 1801Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1802 // Check for unexpanded parameter packs. 1803 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 1804 return StmtError(); 1805 1806 if (getCurBlock()) 1807 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 1808 1809 QualType FnRetType; 1810 QualType DeclaredRetType; 1811 if (const FunctionDecl *FD = getCurFunctionDecl()) { 1812 FnRetType = FD->getResultType(); 1813 DeclaredRetType = FnRetType; 1814 if (FD->hasAttr<NoReturnAttr>() || 1815 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 1816 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 1817 << getCurFunctionOrMethodDecl()->getDeclName(); 1818 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 1819 DeclaredRetType = MD->getResultType(); 1820 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 1821 // In the implementation of a method with a related return type, the 1822 // type used to type-check the validity of return statements within the 1823 // method body is a pointer to the type of the class being implemented. 1824 FnRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 1825 FnRetType = Context.getObjCObjectPointerType(FnRetType); 1826 } else { 1827 FnRetType = DeclaredRetType; 1828 } 1829 } else // If we don't have a function/method context, bail. 1830 return StmtError(); 1831 1832 ReturnStmt *Result = 0; 1833 if (FnRetType->isVoidType()) { 1834 if (RetValExp) { 1835 if (!RetValExp->isTypeDependent()) { 1836 // C99 6.8.6.4p1 (ext_ since GCC warns) 1837 unsigned D = diag::ext_return_has_expr; 1838 if (RetValExp->getType()->isVoidType()) 1839 D = diag::ext_return_has_void_expr; 1840 else { 1841 ExprResult Result = Owned(RetValExp); 1842 Result = IgnoredValueConversions(Result.take()); 1843 if (Result.isInvalid()) 1844 return StmtError(); 1845 RetValExp = Result.take(); 1846 RetValExp = ImpCastExprToType(RetValExp, 1847 Context.VoidTy, CK_ToVoid).take(); 1848 } 1849 1850 // return (some void expression); is legal in C++. 1851 if (D != diag::ext_return_has_void_expr || 1852 !getLangOptions().CPlusPlus) { 1853 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 1854 1855 int FunctionKind = 0; 1856 if (isa<ObjCMethodDecl>(CurDecl)) 1857 FunctionKind = 1; 1858 else if (isa<CXXConstructorDecl>(CurDecl)) 1859 FunctionKind = 2; 1860 else if (isa<CXXDestructorDecl>(CurDecl)) 1861 FunctionKind = 3; 1862 1863 Diag(ReturnLoc, D) 1864 << CurDecl->getDeclName() << FunctionKind 1865 << RetValExp->getSourceRange(); 1866 } 1867 } 1868 1869 CheckImplicitConversions(RetValExp, ReturnLoc); 1870 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1871 } 1872 1873 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1874 } else if (!RetValExp && !FnRetType->isDependentType()) { 1875 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 1876 // C99 6.8.6.4p1 (ext_ since GCC warns) 1877 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 1878 1879 if (FunctionDecl *FD = getCurFunctionDecl()) 1880 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 1881 else 1882 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 1883 Result = new (Context) ReturnStmt(ReturnLoc); 1884 } else { 1885 const VarDecl *NRVOCandidate = 0; 1886 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1887 // we have a non-void function with an expression, continue checking 1888 1889 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1890 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1891 // function return. 1892 1893 // In C++ the return statement is handled via a copy initialization, 1894 // the C version of which boils down to CheckSingleAssignmentConstraints. 1895 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1896 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1897 FnRetType, 1898 NRVOCandidate != 0); 1899 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1900 FnRetType, RetValExp); 1901 if (Res.isInvalid()) { 1902 // FIXME: Cleanup temporaries here, anyway? 1903 return StmtError(); 1904 } 1905 1906 RetValExp = Res.takeAs<Expr>(); 1907 if (RetValExp) 1908 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1909 } 1910 1911 if (RetValExp) { 1912 // If we type-checked an Objective-C method's return type based 1913 // on a related return type, we may need to adjust the return 1914 // type again. Do so now. 1915 if (DeclaredRetType != FnRetType) { 1916 ExprResult result = PerformImplicitConversion(RetValExp, 1917 DeclaredRetType, 1918 AA_Returning); 1919 if (result.isInvalid()) return StmtError(); 1920 RetValExp = result.take(); 1921 } 1922 1923 CheckImplicitConversions(RetValExp, ReturnLoc); 1924 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1925 } 1926 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1927 } 1928 1929 // If we need to check for the named return value optimization, save the 1930 // return statement in our scope for later processing. 1931 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1932 !CurContext->isDependentContext()) 1933 FunctionScopes.back()->Returns.push_back(Result); 1934 1935 return Owned(Result); 1936} 1937 1938/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 1939/// ignore "noop" casts in places where an lvalue is required by an inline asm. 1940/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 1941/// provide a strong guidance to not use it. 1942/// 1943/// This method checks to see if the argument is an acceptable l-value and 1944/// returns false if it is a case we can handle. 1945static bool CheckAsmLValue(const Expr *E, Sema &S) { 1946 // Type dependent expressions will be checked during instantiation. 1947 if (E->isTypeDependent()) 1948 return false; 1949 1950 if (E->isLValue()) 1951 return false; // Cool, this is an lvalue. 1952 1953 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 1954 // are supposed to allow. 1955 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 1956 if (E != E2 && E2->isLValue()) { 1957 if (!S.getLangOptions().HeinousExtensions) 1958 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 1959 << E->getSourceRange(); 1960 else 1961 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 1962 << E->getSourceRange(); 1963 // Accept, even if we emitted an error diagnostic. 1964 return false; 1965 } 1966 1967 // None of the above, just randomly invalid non-lvalue. 1968 return true; 1969} 1970 1971/// isOperandMentioned - Return true if the specified operand # is mentioned 1972/// anywhere in the decomposed asm string. 1973static bool isOperandMentioned(unsigned OpNo, 1974 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 1975 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 1976 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 1977 if (!Piece.isOperand()) continue; 1978 1979 // If this is a reference to the input and if the input was the smaller 1980 // one, then we have to reject this asm. 1981 if (Piece.getOperandNo() == OpNo) 1982 return true; 1983 } 1984 1985 return false; 1986} 1987 1988StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 1989 bool IsVolatile, unsigned NumOutputs, 1990 unsigned NumInputs, IdentifierInfo **Names, 1991 MultiExprArg constraints, MultiExprArg exprs, 1992 Expr *asmString, MultiExprArg clobbers, 1993 SourceLocation RParenLoc, bool MSAsm) { 1994 unsigned NumClobbers = clobbers.size(); 1995 StringLiteral **Constraints = 1996 reinterpret_cast<StringLiteral**>(constraints.get()); 1997 Expr **Exprs = exprs.get(); 1998 StringLiteral *AsmString = cast<StringLiteral>(asmString); 1999 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 2000 2001 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2002 2003 // The parser verifies that there is a string literal here. 2004 if (!AsmString->isAscii()) 2005 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2006 << AsmString->getSourceRange()); 2007 2008 for (unsigned i = 0; i != NumOutputs; i++) { 2009 StringLiteral *Literal = Constraints[i]; 2010 if (!Literal->isAscii()) 2011 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2012 << Literal->getSourceRange()); 2013 2014 StringRef OutputName; 2015 if (Names[i]) 2016 OutputName = Names[i]->getName(); 2017 2018 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2019 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2020 return StmtError(Diag(Literal->getLocStart(), 2021 diag::err_asm_invalid_output_constraint) 2022 << Info.getConstraintStr()); 2023 2024 // Check that the output exprs are valid lvalues. 2025 Expr *OutputExpr = Exprs[i]; 2026 if (CheckAsmLValue(OutputExpr, *this)) { 2027 return StmtError(Diag(OutputExpr->getLocStart(), 2028 diag::err_asm_invalid_lvalue_in_output) 2029 << OutputExpr->getSourceRange()); 2030 } 2031 2032 OutputConstraintInfos.push_back(Info); 2033 } 2034 2035 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2036 2037 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2038 StringLiteral *Literal = Constraints[i]; 2039 if (!Literal->isAscii()) 2040 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2041 << Literal->getSourceRange()); 2042 2043 StringRef InputName; 2044 if (Names[i]) 2045 InputName = Names[i]->getName(); 2046 2047 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2048 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2049 NumOutputs, Info)) { 2050 return StmtError(Diag(Literal->getLocStart(), 2051 diag::err_asm_invalid_input_constraint) 2052 << Info.getConstraintStr()); 2053 } 2054 2055 Expr *InputExpr = Exprs[i]; 2056 2057 // Only allow void types for memory constraints. 2058 if (Info.allowsMemory() && !Info.allowsRegister()) { 2059 if (CheckAsmLValue(InputExpr, *this)) 2060 return StmtError(Diag(InputExpr->getLocStart(), 2061 diag::err_asm_invalid_lvalue_in_input) 2062 << Info.getConstraintStr() 2063 << InputExpr->getSourceRange()); 2064 } 2065 2066 if (Info.allowsRegister()) { 2067 if (InputExpr->getType()->isVoidType()) { 2068 return StmtError(Diag(InputExpr->getLocStart(), 2069 diag::err_asm_invalid_type_in_input) 2070 << InputExpr->getType() << Info.getConstraintStr() 2071 << InputExpr->getSourceRange()); 2072 } 2073 } 2074 2075 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2076 if (Result.isInvalid()) 2077 return StmtError(); 2078 2079 Exprs[i] = Result.take(); 2080 InputConstraintInfos.push_back(Info); 2081 } 2082 2083 // Check that the clobbers are valid. 2084 for (unsigned i = 0; i != NumClobbers; i++) { 2085 StringLiteral *Literal = Clobbers[i]; 2086 if (!Literal->isAscii()) 2087 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2088 << Literal->getSourceRange()); 2089 2090 StringRef Clobber = Literal->getString(); 2091 2092 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2093 return StmtError(Diag(Literal->getLocStart(), 2094 diag::err_asm_unknown_register_name) << Clobber); 2095 } 2096 2097 AsmStmt *NS = 2098 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2099 NumOutputs, NumInputs, Names, Constraints, Exprs, 2100 AsmString, NumClobbers, Clobbers, RParenLoc); 2101 // Validate the asm string, ensuring it makes sense given the operands we 2102 // have. 2103 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2104 unsigned DiagOffs; 2105 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2106 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2107 << AsmString->getSourceRange(); 2108 return StmtError(); 2109 } 2110 2111 // Validate tied input operands for type mismatches. 2112 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2113 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2114 2115 // If this is a tied constraint, verify that the output and input have 2116 // either exactly the same type, or that they are int/ptr operands with the 2117 // same size (int/long, int*/long, are ok etc). 2118 if (!Info.hasTiedOperand()) continue; 2119 2120 unsigned TiedTo = Info.getTiedOperand(); 2121 unsigned InputOpNo = i+NumOutputs; 2122 Expr *OutputExpr = Exprs[TiedTo]; 2123 Expr *InputExpr = Exprs[InputOpNo]; 2124 QualType InTy = InputExpr->getType(); 2125 QualType OutTy = OutputExpr->getType(); 2126 if (Context.hasSameType(InTy, OutTy)) 2127 continue; // All types can be tied to themselves. 2128 2129 // Decide if the input and output are in the same domain (integer/ptr or 2130 // floating point. 2131 enum AsmDomain { 2132 AD_Int, AD_FP, AD_Other 2133 } InputDomain, OutputDomain; 2134 2135 if (InTy->isIntegerType() || InTy->isPointerType()) 2136 InputDomain = AD_Int; 2137 else if (InTy->isRealFloatingType()) 2138 InputDomain = AD_FP; 2139 else 2140 InputDomain = AD_Other; 2141 2142 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2143 OutputDomain = AD_Int; 2144 else if (OutTy->isRealFloatingType()) 2145 OutputDomain = AD_FP; 2146 else 2147 OutputDomain = AD_Other; 2148 2149 // They are ok if they are the same size and in the same domain. This 2150 // allows tying things like: 2151 // void* to int* 2152 // void* to int if they are the same size. 2153 // double to long double if they are the same size. 2154 // 2155 uint64_t OutSize = Context.getTypeSize(OutTy); 2156 uint64_t InSize = Context.getTypeSize(InTy); 2157 if (OutSize == InSize && InputDomain == OutputDomain && 2158 InputDomain != AD_Other) 2159 continue; 2160 2161 // If the smaller input/output operand is not mentioned in the asm string, 2162 // then we can promote the smaller one to a larger input and the asm string 2163 // won't notice. 2164 bool SmallerValueMentioned = false; 2165 2166 // If this is a reference to the input and if the input was the smaller 2167 // one, then we have to reject this asm. 2168 if (isOperandMentioned(InputOpNo, Pieces)) { 2169 // This is a use in the asm string of the smaller operand. Since we 2170 // codegen this by promoting to a wider value, the asm will get printed 2171 // "wrong". 2172 SmallerValueMentioned |= InSize < OutSize; 2173 } 2174 if (isOperandMentioned(TiedTo, Pieces)) { 2175 // If this is a reference to the output, and if the output is the larger 2176 // value, then it's ok because we'll promote the input to the larger type. 2177 SmallerValueMentioned |= OutSize < InSize; 2178 } 2179 2180 // If the smaller value wasn't mentioned in the asm string, and if the 2181 // output was a register, just extend the shorter one to the size of the 2182 // larger one. 2183 if (!SmallerValueMentioned && InputDomain != AD_Other && 2184 OutputConstraintInfos[TiedTo].allowsRegister()) 2185 continue; 2186 2187 // Either both of the operands were mentioned or the smaller one was 2188 // mentioned. One more special case that we'll allow: if the tied input is 2189 // integer, unmentioned, and is a constant, then we'll allow truncating it 2190 // down to the size of the destination. 2191 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2192 !isOperandMentioned(InputOpNo, Pieces) && 2193 InputExpr->isEvaluatable(Context)) { 2194 CastKind castKind = 2195 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2196 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2197 Exprs[InputOpNo] = InputExpr; 2198 NS->setInputExpr(i, InputExpr); 2199 continue; 2200 } 2201 2202 Diag(InputExpr->getLocStart(), 2203 diag::err_asm_tying_incompatible_types) 2204 << InTy << OutTy << OutputExpr->getSourceRange() 2205 << InputExpr->getSourceRange(); 2206 return StmtError(); 2207 } 2208 2209 return Owned(NS); 2210} 2211 2212StmtResult 2213Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2214 SourceLocation RParen, Decl *Parm, 2215 Stmt *Body) { 2216 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2217 if (Var && Var->isInvalidDecl()) 2218 return StmtError(); 2219 2220 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2221} 2222 2223StmtResult 2224Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2225 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2226} 2227 2228StmtResult 2229Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2230 MultiStmtArg CatchStmts, Stmt *Finally) { 2231 if (!getLangOptions().ObjCExceptions) 2232 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2233 2234 getCurFunction()->setHasBranchProtectedScope(); 2235 unsigned NumCatchStmts = CatchStmts.size(); 2236 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2237 CatchStmts.release(), 2238 NumCatchStmts, 2239 Finally)); 2240} 2241 2242StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2243 Expr *Throw) { 2244 if (Throw) { 2245 Throw = MaybeCreateExprWithCleanups(Throw); 2246 ExprResult Result = DefaultLvalueConversion(Throw); 2247 if (Result.isInvalid()) 2248 return StmtError(); 2249 2250 Throw = Result.take(); 2251 QualType ThrowType = Throw->getType(); 2252 // Make sure the expression type is an ObjC pointer or "void *". 2253 if (!ThrowType->isDependentType() && 2254 !ThrowType->isObjCObjectPointerType()) { 2255 const PointerType *PT = ThrowType->getAs<PointerType>(); 2256 if (!PT || !PT->getPointeeType()->isVoidType()) 2257 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2258 << Throw->getType() << Throw->getSourceRange()); 2259 } 2260 } 2261 2262 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2263} 2264 2265StmtResult 2266Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2267 Scope *CurScope) { 2268 if (!getLangOptions().ObjCExceptions) 2269 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2270 2271 if (!Throw) { 2272 // @throw without an expression designates a rethrow (which much occur 2273 // in the context of an @catch clause). 2274 Scope *AtCatchParent = CurScope; 2275 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2276 AtCatchParent = AtCatchParent->getParent(); 2277 if (!AtCatchParent) 2278 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2279 } 2280 2281 return BuildObjCAtThrowStmt(AtLoc, Throw); 2282} 2283 2284ExprResult 2285Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2286 ExprResult result = DefaultLvalueConversion(operand); 2287 if (result.isInvalid()) 2288 return ExprError(); 2289 operand = result.take(); 2290 2291 // Make sure the expression type is an ObjC pointer or "void *". 2292 QualType type = operand->getType(); 2293 if (!type->isDependentType() && 2294 !type->isObjCObjectPointerType()) { 2295 const PointerType *pointerType = type->getAs<PointerType>(); 2296 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2297 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2298 << type << operand->getSourceRange(); 2299 } 2300 2301 // The operand to @synchronized is a full-expression. 2302 return MaybeCreateExprWithCleanups(operand); 2303} 2304 2305StmtResult 2306Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2307 Stmt *SyncBody) { 2308 // We can't jump into or indirect-jump out of a @synchronized block. 2309 getCurFunction()->setHasBranchProtectedScope(); 2310 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2311} 2312 2313/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2314/// and creates a proper catch handler from them. 2315StmtResult 2316Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2317 Stmt *HandlerBlock) { 2318 // There's nothing to test that ActOnExceptionDecl didn't already test. 2319 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2320 cast_or_null<VarDecl>(ExDecl), 2321 HandlerBlock)); 2322} 2323 2324StmtResult 2325Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2326 getCurFunction()->setHasBranchProtectedScope(); 2327 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2328} 2329 2330namespace { 2331 2332class TypeWithHandler { 2333 QualType t; 2334 CXXCatchStmt *stmt; 2335public: 2336 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2337 : t(type), stmt(statement) {} 2338 2339 // An arbitrary order is fine as long as it places identical 2340 // types next to each other. 2341 bool operator<(const TypeWithHandler &y) const { 2342 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2343 return true; 2344 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2345 return false; 2346 else 2347 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2348 } 2349 2350 bool operator==(const TypeWithHandler& other) const { 2351 return t == other.t; 2352 } 2353 2354 CXXCatchStmt *getCatchStmt() const { return stmt; } 2355 SourceLocation getTypeSpecStartLoc() const { 2356 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2357 } 2358}; 2359 2360} 2361 2362/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2363/// handlers and creates a try statement from them. 2364StmtResult 2365Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2366 MultiStmtArg RawHandlers) { 2367 // Don't report an error if 'try' is used in system headers. 2368 if (!getLangOptions().CXXExceptions && 2369 !getSourceManager().isInSystemHeader(TryLoc)) 2370 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2371 2372 unsigned NumHandlers = RawHandlers.size(); 2373 assert(NumHandlers > 0 && 2374 "The parser shouldn't call this if there are no handlers."); 2375 Stmt **Handlers = RawHandlers.get(); 2376 2377 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2378 2379 for (unsigned i = 0; i < NumHandlers; ++i) { 2380 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 2381 if (!Handler->getExceptionDecl()) { 2382 if (i < NumHandlers - 1) 2383 return StmtError(Diag(Handler->getLocStart(), 2384 diag::err_early_catch_all)); 2385 2386 continue; 2387 } 2388 2389 const QualType CaughtType = Handler->getCaughtType(); 2390 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2391 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2392 } 2393 2394 // Detect handlers for the same type as an earlier one. 2395 if (NumHandlers > 1) { 2396 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2397 2398 TypeWithHandler prev = TypesWithHandlers[0]; 2399 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2400 TypeWithHandler curr = TypesWithHandlers[i]; 2401 2402 if (curr == prev) { 2403 Diag(curr.getTypeSpecStartLoc(), 2404 diag::warn_exception_caught_by_earlier_handler) 2405 << curr.getCatchStmt()->getCaughtType().getAsString(); 2406 Diag(prev.getTypeSpecStartLoc(), 2407 diag::note_previous_exception_handler) 2408 << prev.getCatchStmt()->getCaughtType().getAsString(); 2409 } 2410 2411 prev = curr; 2412 } 2413 } 2414 2415 getCurFunction()->setHasBranchProtectedScope(); 2416 2417 // FIXME: We should detect handlers that cannot catch anything because an 2418 // earlier handler catches a superclass. Need to find a method that is not 2419 // quadratic for this. 2420 // Neither of these are explicitly forbidden, but every compiler detects them 2421 // and warns. 2422 2423 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2424 Handlers, NumHandlers)); 2425} 2426 2427StmtResult 2428Sema::ActOnSEHTryBlock(bool IsCXXTry, 2429 SourceLocation TryLoc, 2430 Stmt *TryBlock, 2431 Stmt *Handler) { 2432 assert(TryBlock && Handler); 2433 2434 getCurFunction()->setHasBranchProtectedScope(); 2435 2436 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2437} 2438 2439StmtResult 2440Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2441 Expr *FilterExpr, 2442 Stmt *Block) { 2443 assert(FilterExpr && Block); 2444 2445 if(!FilterExpr->getType()->isIntegerType()) { 2446 return StmtError(Diag(FilterExpr->getExprLoc(), 2447 diag::err_filter_expression_integral) 2448 << FilterExpr->getType()); 2449 } 2450 2451 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2452} 2453 2454StmtResult 2455Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2456 Stmt *Block) { 2457 assert(Block); 2458 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2459} 2460