SemaStmt.cpp revision eb2d1f1c88836bd5382e5d7aa8f6b85148a88b27
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 llvm_unreachable("Unexpected array type in for-range"); 1391 } 1392 1393 // end-expr is __range + __bound. 1394 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, RangeRef.get(), 1395 BoundExpr.get()); 1396 if (EndExpr.isInvalid()) 1397 return StmtError(); 1398 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1399 diag::err_for_range_iter_deduction_failure)) { 1400 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1401 return StmtError(); 1402 } 1403 } else { 1404 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1405 ColonLoc); 1406 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1407 ColonLoc); 1408 1409 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1410 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1411 1412 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1413 // - if _RangeT is a class type, the unqualified-ids begin and end are 1414 // looked up in the scope of class _RangeT as if by class member access 1415 // lookup (3.4.5), and if either (or both) finds at least one 1416 // declaration, begin-expr and end-expr are __range.begin() and 1417 // __range.end(), respectively; 1418 LookupQualifiedName(BeginMemberLookup, D); 1419 LookupQualifiedName(EndMemberLookup, D); 1420 1421 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1422 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1423 << RangeType << BeginMemberLookup.empty(); 1424 return StmtError(); 1425 } 1426 } else { 1427 // - otherwise, begin-expr and end-expr are begin(__range) and 1428 // end(__range), respectively, where begin and end are looked up with 1429 // argument-dependent lookup (3.4.2). For the purposes of this name 1430 // lookup, namespace std is an associated namespace. 1431 } 1432 1433 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1434 BEF_begin, BeginNameInfo, 1435 BeginMemberLookup, RangeRef.get()); 1436 if (BeginExpr.isInvalid()) 1437 return StmtError(); 1438 1439 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1440 BEF_end, EndNameInfo, 1441 EndMemberLookup, RangeRef.get()); 1442 if (EndExpr.isInvalid()) 1443 return StmtError(); 1444 } 1445 1446 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1447 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1448 if (!Context.hasSameType(BeginType, EndType)) { 1449 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1450 << BeginType << EndType; 1451 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1452 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1453 } 1454 1455 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1456 // Claim the type doesn't contain auto: we've already done the checking. 1457 DeclGroupPtrTy BeginEndGroup = 1458 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1459 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1460 1461 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, 1462 BeginType.getNonReferenceType(), 1463 VK_LValue, ColonLoc); 1464 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1465 VK_LValue, ColonLoc); 1466 1467 // Build and check __begin != __end expression. 1468 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1469 BeginRef.get(), EndRef.get()); 1470 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1471 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1472 if (NotEqExpr.isInvalid()) { 1473 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1474 if (!Context.hasSameType(BeginType, EndType)) 1475 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1476 return StmtError(); 1477 } 1478 1479 // Build and check ++__begin expression. 1480 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1481 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1482 if (IncrExpr.isInvalid()) { 1483 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1484 return StmtError(); 1485 } 1486 1487 // Build and check *__begin expression. 1488 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1489 if (DerefExpr.isInvalid()) { 1490 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1491 return StmtError(); 1492 } 1493 1494 // Attach *__begin as initializer for VD. 1495 if (!LoopVar->isInvalidDecl()) { 1496 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1497 /*TypeMayContainAuto=*/true); 1498 if (LoopVar->isInvalidDecl()) 1499 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1500 } 1501 } else { 1502 // The range is implicitly used as a placeholder when it is dependent. 1503 RangeVar->setUsed(); 1504 } 1505 1506 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1507 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1508 NotEqExpr.take(), IncrExpr.take(), 1509 LoopVarDS, /*Body=*/0, ForLoc, 1510 ColonLoc, RParenLoc)); 1511} 1512 1513/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1514/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1515/// body cannot be performed until after the type of the range variable is 1516/// determined. 1517StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1518 if (!S || !B) 1519 return StmtError(); 1520 1521 cast<CXXForRangeStmt>(S)->setBody(B); 1522 return S; 1523} 1524 1525StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 1526 SourceLocation LabelLoc, 1527 LabelDecl *TheDecl) { 1528 getCurFunction()->setHasBranchIntoScope(); 1529 TheDecl->setUsed(); 1530 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 1531} 1532 1533StmtResult 1534Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 1535 Expr *E) { 1536 // Convert operand to void* 1537 if (!E->isTypeDependent()) { 1538 QualType ETy = E->getType(); 1539 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 1540 ExprResult ExprRes = Owned(E); 1541 AssignConvertType ConvTy = 1542 CheckSingleAssignmentConstraints(DestTy, ExprRes); 1543 if (ExprRes.isInvalid()) 1544 return StmtError(); 1545 E = ExprRes.take(); 1546 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 1547 return StmtError(); 1548 } 1549 1550 getCurFunction()->setHasIndirectGoto(); 1551 1552 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 1553} 1554 1555StmtResult 1556Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 1557 Scope *S = CurScope->getContinueParent(); 1558 if (!S) { 1559 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 1560 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 1561 } 1562 1563 return Owned(new (Context) ContinueStmt(ContinueLoc)); 1564} 1565 1566StmtResult 1567Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 1568 Scope *S = CurScope->getBreakParent(); 1569 if (!S) { 1570 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 1571 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 1572 } 1573 1574 return Owned(new (Context) BreakStmt(BreakLoc)); 1575} 1576 1577/// \brief Determine whether the given expression is a candidate for 1578/// copy elision in either a return statement or a throw expression. 1579/// 1580/// \param ReturnType If we're determining the copy elision candidate for 1581/// a return statement, this is the return type of the function. If we're 1582/// determining the copy elision candidate for a throw expression, this will 1583/// be a NULL type. 1584/// 1585/// \param E The expression being returned from the function or block, or 1586/// being thrown. 1587/// 1588/// \param AllowFunctionParameter Whether we allow function parameters to 1589/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 1590/// we re-use this logic to determine whether we should try to move as part of 1591/// a return or throw (which does allow function parameters). 1592/// 1593/// \returns The NRVO candidate variable, if the return statement may use the 1594/// NRVO, or NULL if there is no such candidate. 1595const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 1596 Expr *E, 1597 bool AllowFunctionParameter) { 1598 QualType ExprType = E->getType(); 1599 // - in a return statement in a function with ... 1600 // ... a class return type ... 1601 if (!ReturnType.isNull()) { 1602 if (!ReturnType->isRecordType()) 1603 return 0; 1604 // ... the same cv-unqualified type as the function return type ... 1605 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 1606 return 0; 1607 } 1608 1609 // ... the expression is the name of a non-volatile automatic object 1610 // (other than a function or catch-clause parameter)) ... 1611 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 1612 if (!DR) 1613 return 0; 1614 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 1615 if (!VD) 1616 return 0; 1617 1618 if (VD->hasLocalStorage() && !VD->isExceptionVariable() && 1619 !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() && 1620 !VD->getType().isVolatileQualified() && 1621 ((VD->getKind() == Decl::Var) || 1622 (AllowFunctionParameter && VD->getKind() == Decl::ParmVar))) 1623 return VD; 1624 1625 return 0; 1626} 1627 1628/// \brief Perform the initialization of a potentially-movable value, which 1629/// is the result of return value. 1630/// 1631/// This routine implements C++0x [class.copy]p33, which attempts to treat 1632/// returned lvalues as rvalues in certain cases (to prefer move construction), 1633/// then falls back to treating them as lvalues if that failed. 1634ExprResult 1635Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 1636 const VarDecl *NRVOCandidate, 1637 QualType ResultType, 1638 Expr *Value, 1639 bool AllowNRVO) { 1640 // C++0x [class.copy]p33: 1641 // When the criteria for elision of a copy operation are met or would 1642 // be met save for the fact that the source object is a function 1643 // parameter, and the object to be copied is designated by an lvalue, 1644 // overload resolution to select the constructor for the copy is first 1645 // performed as if the object were designated by an rvalue. 1646 ExprResult Res = ExprError(); 1647 if (AllowNRVO && 1648 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 1649 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 1650 Value->getType(), CK_LValueToRValue, 1651 Value, VK_XValue); 1652 1653 Expr *InitExpr = &AsRvalue; 1654 InitializationKind Kind 1655 = InitializationKind::CreateCopy(Value->getLocStart(), 1656 Value->getLocStart()); 1657 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 1658 1659 // [...] If overload resolution fails, or if the type of the first 1660 // parameter of the selected constructor is not an rvalue reference 1661 // to the object's type (possibly cv-qualified), overload resolution 1662 // is performed again, considering the object as an lvalue. 1663 if (Seq) { 1664 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 1665 StepEnd = Seq.step_end(); 1666 Step != StepEnd; ++Step) { 1667 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 1668 continue; 1669 1670 CXXConstructorDecl *Constructor 1671 = cast<CXXConstructorDecl>(Step->Function.Function); 1672 1673 const RValueReferenceType *RRefType 1674 = Constructor->getParamDecl(0)->getType() 1675 ->getAs<RValueReferenceType>(); 1676 1677 // If we don't meet the criteria, break out now. 1678 if (!RRefType || 1679 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 1680 Context.getTypeDeclType(Constructor->getParent()))) 1681 break; 1682 1683 // Promote "AsRvalue" to the heap, since we now need this 1684 // expression node to persist. 1685 Value = ImplicitCastExpr::Create(Context, Value->getType(), 1686 CK_LValueToRValue, Value, 0, 1687 VK_XValue); 1688 1689 // Complete type-checking the initialization of the return type 1690 // using the constructor we found. 1691 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 1692 } 1693 } 1694 } 1695 1696 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 1697 // above, or overload resolution failed. Either way, we need to try 1698 // (again) now with the return value expression as written. 1699 if (Res.isInvalid()) 1700 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 1701 1702 return Res; 1703} 1704 1705/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 1706/// 1707StmtResult 1708Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1709 // If this is the first return we've seen in the block, infer the type of 1710 // the block from it. 1711 BlockScopeInfo *CurBlock = getCurBlock(); 1712 if (CurBlock->ReturnType.isNull()) { 1713 if (RetValExp) { 1714 // Don't call UsualUnaryConversions(), since we don't want to do 1715 // integer promotions here. 1716 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 1717 if (Result.isInvalid()) 1718 return StmtError(); 1719 RetValExp = Result.take(); 1720 1721 if (!RetValExp->isTypeDependent()) { 1722 CurBlock->ReturnType = RetValExp->getType(); 1723 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) { 1724 // We have to remove a 'const' added to copied-in variable which was 1725 // part of the implementation spec. and not the actual qualifier for 1726 // the variable. 1727 if (CDRE->isConstQualAdded()) 1728 CurBlock->ReturnType.removeLocalConst(); // FIXME: local??? 1729 } 1730 } else 1731 CurBlock->ReturnType = Context.DependentTy; 1732 } else 1733 CurBlock->ReturnType = Context.VoidTy; 1734 } 1735 QualType FnRetType = CurBlock->ReturnType; 1736 1737 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 1738 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 1739 << getCurFunctionOrMethodDecl()->getDeclName(); 1740 return StmtError(); 1741 } 1742 1743 // Otherwise, verify that this result type matches the previous one. We are 1744 // pickier with blocks than for normal functions because we don't have GCC 1745 // compatibility to worry about here. 1746 const VarDecl *NRVOCandidate = 0; 1747 if (FnRetType->isDependentType()) { 1748 // Delay processing for now. TODO: there are lots of dependent 1749 // types we can conclusively prove aren't void. 1750 } else if (FnRetType->isVoidType()) { 1751 if (RetValExp && 1752 !(getLangOptions().CPlusPlus && 1753 (RetValExp->isTypeDependent() || 1754 RetValExp->getType()->isVoidType()))) { 1755 Diag(ReturnLoc, diag::err_return_block_has_expr); 1756 RetValExp = 0; 1757 } 1758 } else if (!RetValExp) { 1759 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 1760 } else if (!RetValExp->isTypeDependent()) { 1761 // we have a non-void block with an expression, continue checking 1762 1763 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1764 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1765 // function return. 1766 1767 // In C++ the return statement is handled via a copy initialization. 1768 // the C version of which boils down to CheckSingleAssignmentConstraints. 1769 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1770 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1771 FnRetType, 1772 NRVOCandidate != 0); 1773 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1774 FnRetType, RetValExp); 1775 if (Res.isInvalid()) { 1776 // FIXME: Cleanup temporaries here, anyway? 1777 return StmtError(); 1778 } 1779 RetValExp = Res.take(); 1780 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1781 } 1782 1783 if (RetValExp) { 1784 CheckImplicitConversions(RetValExp, ReturnLoc); 1785 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1786 } 1787 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 1788 NRVOCandidate); 1789 1790 // If we need to check for the named return value optimization, save the 1791 // return statement in our scope for later processing. 1792 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1793 !CurContext->isDependentContext()) 1794 FunctionScopes.back()->Returns.push_back(Result); 1795 1796 return Owned(Result); 1797} 1798 1799StmtResult 1800Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 1801 // Check for unexpanded parameter packs. 1802 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 1803 return StmtError(); 1804 1805 if (getCurBlock()) 1806 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 1807 1808 QualType FnRetType; 1809 QualType DeclaredRetType; 1810 if (const FunctionDecl *FD = getCurFunctionDecl()) { 1811 FnRetType = FD->getResultType(); 1812 DeclaredRetType = FnRetType; 1813 if (FD->hasAttr<NoReturnAttr>() || 1814 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 1815 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 1816 << getCurFunctionOrMethodDecl()->getDeclName(); 1817 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 1818 DeclaredRetType = MD->getResultType(); 1819 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 1820 // In the implementation of a method with a related return type, the 1821 // type used to type-check the validity of return statements within the 1822 // method body is a pointer to the type of the class being implemented. 1823 FnRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 1824 FnRetType = Context.getObjCObjectPointerType(FnRetType); 1825 } else { 1826 FnRetType = DeclaredRetType; 1827 } 1828 } else // If we don't have a function/method context, bail. 1829 return StmtError(); 1830 1831 ReturnStmt *Result = 0; 1832 if (FnRetType->isVoidType()) { 1833 if (RetValExp) { 1834 if (!RetValExp->isTypeDependent()) { 1835 // C99 6.8.6.4p1 (ext_ since GCC warns) 1836 unsigned D = diag::ext_return_has_expr; 1837 if (RetValExp->getType()->isVoidType()) 1838 D = diag::ext_return_has_void_expr; 1839 else { 1840 ExprResult Result = Owned(RetValExp); 1841 Result = IgnoredValueConversions(Result.take()); 1842 if (Result.isInvalid()) 1843 return StmtError(); 1844 RetValExp = Result.take(); 1845 RetValExp = ImpCastExprToType(RetValExp, 1846 Context.VoidTy, CK_ToVoid).take(); 1847 } 1848 1849 // return (some void expression); is legal in C++. 1850 if (D != diag::ext_return_has_void_expr || 1851 !getLangOptions().CPlusPlus) { 1852 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 1853 1854 int FunctionKind = 0; 1855 if (isa<ObjCMethodDecl>(CurDecl)) 1856 FunctionKind = 1; 1857 else if (isa<CXXConstructorDecl>(CurDecl)) 1858 FunctionKind = 2; 1859 else if (isa<CXXDestructorDecl>(CurDecl)) 1860 FunctionKind = 3; 1861 1862 Diag(ReturnLoc, D) 1863 << CurDecl->getDeclName() << FunctionKind 1864 << RetValExp->getSourceRange(); 1865 } 1866 } 1867 1868 CheckImplicitConversions(RetValExp, ReturnLoc); 1869 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1870 } 1871 1872 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 1873 } else if (!RetValExp && !FnRetType->isDependentType()) { 1874 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 1875 // C99 6.8.6.4p1 (ext_ since GCC warns) 1876 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 1877 1878 if (FunctionDecl *FD = getCurFunctionDecl()) 1879 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 1880 else 1881 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 1882 Result = new (Context) ReturnStmt(ReturnLoc); 1883 } else { 1884 const VarDecl *NRVOCandidate = 0; 1885 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 1886 // we have a non-void function with an expression, continue checking 1887 1888 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 1889 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 1890 // function return. 1891 1892 // In C++ the return statement is handled via a copy initialization, 1893 // the C version of which boils down to CheckSingleAssignmentConstraints. 1894 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 1895 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 1896 FnRetType, 1897 NRVOCandidate != 0); 1898 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 1899 FnRetType, RetValExp); 1900 if (Res.isInvalid()) { 1901 // FIXME: Cleanup temporaries here, anyway? 1902 return StmtError(); 1903 } 1904 1905 RetValExp = Res.takeAs<Expr>(); 1906 if (RetValExp) 1907 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 1908 } 1909 1910 if (RetValExp) { 1911 // If we type-checked an Objective-C method's return type based 1912 // on a related return type, we may need to adjust the return 1913 // type again. Do so now. 1914 if (DeclaredRetType != FnRetType) { 1915 ExprResult result = PerformImplicitConversion(RetValExp, 1916 DeclaredRetType, 1917 AA_Returning); 1918 if (result.isInvalid()) return StmtError(); 1919 RetValExp = result.take(); 1920 } 1921 1922 CheckImplicitConversions(RetValExp, ReturnLoc); 1923 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 1924 } 1925 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 1926 } 1927 1928 // If we need to check for the named return value optimization, save the 1929 // return statement in our scope for later processing. 1930 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() && 1931 !CurContext->isDependentContext()) 1932 FunctionScopes.back()->Returns.push_back(Result); 1933 1934 return Owned(Result); 1935} 1936 1937/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 1938/// ignore "noop" casts in places where an lvalue is required by an inline asm. 1939/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 1940/// provide a strong guidance to not use it. 1941/// 1942/// This method checks to see if the argument is an acceptable l-value and 1943/// returns false if it is a case we can handle. 1944static bool CheckAsmLValue(const Expr *E, Sema &S) { 1945 // Type dependent expressions will be checked during instantiation. 1946 if (E->isTypeDependent()) 1947 return false; 1948 1949 if (E->isLValue()) 1950 return false; // Cool, this is an lvalue. 1951 1952 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 1953 // are supposed to allow. 1954 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 1955 if (E != E2 && E2->isLValue()) { 1956 if (!S.getLangOptions().HeinousExtensions) 1957 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 1958 << E->getSourceRange(); 1959 else 1960 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 1961 << E->getSourceRange(); 1962 // Accept, even if we emitted an error diagnostic. 1963 return false; 1964 } 1965 1966 // None of the above, just randomly invalid non-lvalue. 1967 return true; 1968} 1969 1970/// isOperandMentioned - Return true if the specified operand # is mentioned 1971/// anywhere in the decomposed asm string. 1972static bool isOperandMentioned(unsigned OpNo, 1973 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 1974 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 1975 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 1976 if (!Piece.isOperand()) continue; 1977 1978 // If this is a reference to the input and if the input was the smaller 1979 // one, then we have to reject this asm. 1980 if (Piece.getOperandNo() == OpNo) 1981 return true; 1982 } 1983 1984 return false; 1985} 1986 1987StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 1988 bool IsVolatile, unsigned NumOutputs, 1989 unsigned NumInputs, IdentifierInfo **Names, 1990 MultiExprArg constraints, MultiExprArg exprs, 1991 Expr *asmString, MultiExprArg clobbers, 1992 SourceLocation RParenLoc, bool MSAsm) { 1993 unsigned NumClobbers = clobbers.size(); 1994 StringLiteral **Constraints = 1995 reinterpret_cast<StringLiteral**>(constraints.get()); 1996 Expr **Exprs = exprs.get(); 1997 StringLiteral *AsmString = cast<StringLiteral>(asmString); 1998 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 1999 2000 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2001 2002 // The parser verifies that there is a string literal here. 2003 if (!AsmString->isAscii()) 2004 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2005 << AsmString->getSourceRange()); 2006 2007 for (unsigned i = 0; i != NumOutputs; i++) { 2008 StringLiteral *Literal = Constraints[i]; 2009 if (!Literal->isAscii()) 2010 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2011 << Literal->getSourceRange()); 2012 2013 StringRef OutputName; 2014 if (Names[i]) 2015 OutputName = Names[i]->getName(); 2016 2017 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2018 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2019 return StmtError(Diag(Literal->getLocStart(), 2020 diag::err_asm_invalid_output_constraint) 2021 << Info.getConstraintStr()); 2022 2023 // Check that the output exprs are valid lvalues. 2024 Expr *OutputExpr = Exprs[i]; 2025 if (CheckAsmLValue(OutputExpr, *this)) { 2026 return StmtError(Diag(OutputExpr->getLocStart(), 2027 diag::err_asm_invalid_lvalue_in_output) 2028 << OutputExpr->getSourceRange()); 2029 } 2030 2031 OutputConstraintInfos.push_back(Info); 2032 } 2033 2034 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2035 2036 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2037 StringLiteral *Literal = Constraints[i]; 2038 if (!Literal->isAscii()) 2039 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2040 << Literal->getSourceRange()); 2041 2042 StringRef InputName; 2043 if (Names[i]) 2044 InputName = Names[i]->getName(); 2045 2046 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2047 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2048 NumOutputs, Info)) { 2049 return StmtError(Diag(Literal->getLocStart(), 2050 diag::err_asm_invalid_input_constraint) 2051 << Info.getConstraintStr()); 2052 } 2053 2054 Expr *InputExpr = Exprs[i]; 2055 2056 // Only allow void types for memory constraints. 2057 if (Info.allowsMemory() && !Info.allowsRegister()) { 2058 if (CheckAsmLValue(InputExpr, *this)) 2059 return StmtError(Diag(InputExpr->getLocStart(), 2060 diag::err_asm_invalid_lvalue_in_input) 2061 << Info.getConstraintStr() 2062 << InputExpr->getSourceRange()); 2063 } 2064 2065 if (Info.allowsRegister()) { 2066 if (InputExpr->getType()->isVoidType()) { 2067 return StmtError(Diag(InputExpr->getLocStart(), 2068 diag::err_asm_invalid_type_in_input) 2069 << InputExpr->getType() << Info.getConstraintStr() 2070 << InputExpr->getSourceRange()); 2071 } 2072 } 2073 2074 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2075 if (Result.isInvalid()) 2076 return StmtError(); 2077 2078 Exprs[i] = Result.take(); 2079 InputConstraintInfos.push_back(Info); 2080 } 2081 2082 // Check that the clobbers are valid. 2083 for (unsigned i = 0; i != NumClobbers; i++) { 2084 StringLiteral *Literal = Clobbers[i]; 2085 if (!Literal->isAscii()) 2086 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2087 << Literal->getSourceRange()); 2088 2089 StringRef Clobber = Literal->getString(); 2090 2091 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2092 return StmtError(Diag(Literal->getLocStart(), 2093 diag::err_asm_unknown_register_name) << Clobber); 2094 } 2095 2096 AsmStmt *NS = 2097 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2098 NumOutputs, NumInputs, Names, Constraints, Exprs, 2099 AsmString, NumClobbers, Clobbers, RParenLoc); 2100 // Validate the asm string, ensuring it makes sense given the operands we 2101 // have. 2102 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2103 unsigned DiagOffs; 2104 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2105 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2106 << AsmString->getSourceRange(); 2107 return StmtError(); 2108 } 2109 2110 // Validate tied input operands for type mismatches. 2111 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2112 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2113 2114 // If this is a tied constraint, verify that the output and input have 2115 // either exactly the same type, or that they are int/ptr operands with the 2116 // same size (int/long, int*/long, are ok etc). 2117 if (!Info.hasTiedOperand()) continue; 2118 2119 unsigned TiedTo = Info.getTiedOperand(); 2120 unsigned InputOpNo = i+NumOutputs; 2121 Expr *OutputExpr = Exprs[TiedTo]; 2122 Expr *InputExpr = Exprs[InputOpNo]; 2123 2124 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) 2125 continue; 2126 2127 QualType InTy = InputExpr->getType(); 2128 QualType OutTy = OutputExpr->getType(); 2129 if (Context.hasSameType(InTy, OutTy)) 2130 continue; // All types can be tied to themselves. 2131 2132 // Decide if the input and output are in the same domain (integer/ptr or 2133 // floating point. 2134 enum AsmDomain { 2135 AD_Int, AD_FP, AD_Other 2136 } InputDomain, OutputDomain; 2137 2138 if (InTy->isIntegerType() || InTy->isPointerType()) 2139 InputDomain = AD_Int; 2140 else if (InTy->isRealFloatingType()) 2141 InputDomain = AD_FP; 2142 else 2143 InputDomain = AD_Other; 2144 2145 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2146 OutputDomain = AD_Int; 2147 else if (OutTy->isRealFloatingType()) 2148 OutputDomain = AD_FP; 2149 else 2150 OutputDomain = AD_Other; 2151 2152 // They are ok if they are the same size and in the same domain. This 2153 // allows tying things like: 2154 // void* to int* 2155 // void* to int if they are the same size. 2156 // double to long double if they are the same size. 2157 // 2158 uint64_t OutSize = Context.getTypeSize(OutTy); 2159 uint64_t InSize = Context.getTypeSize(InTy); 2160 if (OutSize == InSize && InputDomain == OutputDomain && 2161 InputDomain != AD_Other) 2162 continue; 2163 2164 // If the smaller input/output operand is not mentioned in the asm string, 2165 // then we can promote the smaller one to a larger input and the asm string 2166 // won't notice. 2167 bool SmallerValueMentioned = false; 2168 2169 // If this is a reference to the input and if the input was the smaller 2170 // one, then we have to reject this asm. 2171 if (isOperandMentioned(InputOpNo, Pieces)) { 2172 // This is a use in the asm string of the smaller operand. Since we 2173 // codegen this by promoting to a wider value, the asm will get printed 2174 // "wrong". 2175 SmallerValueMentioned |= InSize < OutSize; 2176 } 2177 if (isOperandMentioned(TiedTo, Pieces)) { 2178 // If this is a reference to the output, and if the output is the larger 2179 // value, then it's ok because we'll promote the input to the larger type. 2180 SmallerValueMentioned |= OutSize < InSize; 2181 } 2182 2183 // If the smaller value wasn't mentioned in the asm string, and if the 2184 // output was a register, just extend the shorter one to the size of the 2185 // larger one. 2186 if (!SmallerValueMentioned && InputDomain != AD_Other && 2187 OutputConstraintInfos[TiedTo].allowsRegister()) 2188 continue; 2189 2190 // Either both of the operands were mentioned or the smaller one was 2191 // mentioned. One more special case that we'll allow: if the tied input is 2192 // integer, unmentioned, and is a constant, then we'll allow truncating it 2193 // down to the size of the destination. 2194 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2195 !isOperandMentioned(InputOpNo, Pieces) && 2196 InputExpr->isEvaluatable(Context)) { 2197 CastKind castKind = 2198 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2199 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2200 Exprs[InputOpNo] = InputExpr; 2201 NS->setInputExpr(i, InputExpr); 2202 continue; 2203 } 2204 2205 Diag(InputExpr->getLocStart(), 2206 diag::err_asm_tying_incompatible_types) 2207 << InTy << OutTy << OutputExpr->getSourceRange() 2208 << InputExpr->getSourceRange(); 2209 return StmtError(); 2210 } 2211 2212 return Owned(NS); 2213} 2214 2215StmtResult 2216Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2217 SourceLocation RParen, Decl *Parm, 2218 Stmt *Body) { 2219 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2220 if (Var && Var->isInvalidDecl()) 2221 return StmtError(); 2222 2223 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2224} 2225 2226StmtResult 2227Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2228 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2229} 2230 2231StmtResult 2232Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2233 MultiStmtArg CatchStmts, Stmt *Finally) { 2234 if (!getLangOptions().ObjCExceptions) 2235 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2236 2237 getCurFunction()->setHasBranchProtectedScope(); 2238 unsigned NumCatchStmts = CatchStmts.size(); 2239 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2240 CatchStmts.release(), 2241 NumCatchStmts, 2242 Finally)); 2243} 2244 2245StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, 2246 Expr *Throw) { 2247 if (Throw) { 2248 Throw = MaybeCreateExprWithCleanups(Throw); 2249 ExprResult Result = DefaultLvalueConversion(Throw); 2250 if (Result.isInvalid()) 2251 return StmtError(); 2252 2253 Throw = Result.take(); 2254 QualType ThrowType = Throw->getType(); 2255 // Make sure the expression type is an ObjC pointer or "void *". 2256 if (!ThrowType->isDependentType() && 2257 !ThrowType->isObjCObjectPointerType()) { 2258 const PointerType *PT = ThrowType->getAs<PointerType>(); 2259 if (!PT || !PT->getPointeeType()->isVoidType()) 2260 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2261 << Throw->getType() << Throw->getSourceRange()); 2262 } 2263 } 2264 2265 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2266} 2267 2268StmtResult 2269Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 2270 Scope *CurScope) { 2271 if (!getLangOptions().ObjCExceptions) 2272 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 2273 2274 if (!Throw) { 2275 // @throw without an expression designates a rethrow (which much occur 2276 // in the context of an @catch clause). 2277 Scope *AtCatchParent = CurScope; 2278 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 2279 AtCatchParent = AtCatchParent->getParent(); 2280 if (!AtCatchParent) 2281 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 2282 } 2283 2284 return BuildObjCAtThrowStmt(AtLoc, Throw); 2285} 2286 2287ExprResult 2288Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 2289 ExprResult result = DefaultLvalueConversion(operand); 2290 if (result.isInvalid()) 2291 return ExprError(); 2292 operand = result.take(); 2293 2294 // Make sure the expression type is an ObjC pointer or "void *". 2295 QualType type = operand->getType(); 2296 if (!type->isDependentType() && 2297 !type->isObjCObjectPointerType()) { 2298 const PointerType *pointerType = type->getAs<PointerType>(); 2299 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 2300 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 2301 << type << operand->getSourceRange(); 2302 } 2303 2304 // The operand to @synchronized is a full-expression. 2305 return MaybeCreateExprWithCleanups(operand); 2306} 2307 2308StmtResult 2309Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 2310 Stmt *SyncBody) { 2311 // We can't jump into or indirect-jump out of a @synchronized block. 2312 getCurFunction()->setHasBranchProtectedScope(); 2313 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 2314} 2315 2316/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 2317/// and creates a proper catch handler from them. 2318StmtResult 2319Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 2320 Stmt *HandlerBlock) { 2321 // There's nothing to test that ActOnExceptionDecl didn't already test. 2322 return Owned(new (Context) CXXCatchStmt(CatchLoc, 2323 cast_or_null<VarDecl>(ExDecl), 2324 HandlerBlock)); 2325} 2326 2327StmtResult 2328Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 2329 getCurFunction()->setHasBranchProtectedScope(); 2330 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 2331} 2332 2333namespace { 2334 2335class TypeWithHandler { 2336 QualType t; 2337 CXXCatchStmt *stmt; 2338public: 2339 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 2340 : t(type), stmt(statement) {} 2341 2342 // An arbitrary order is fine as long as it places identical 2343 // types next to each other. 2344 bool operator<(const TypeWithHandler &y) const { 2345 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 2346 return true; 2347 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 2348 return false; 2349 else 2350 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 2351 } 2352 2353 bool operator==(const TypeWithHandler& other) const { 2354 return t == other.t; 2355 } 2356 2357 CXXCatchStmt *getCatchStmt() const { return stmt; } 2358 SourceLocation getTypeSpecStartLoc() const { 2359 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 2360 } 2361}; 2362 2363} 2364 2365/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 2366/// handlers and creates a try statement from them. 2367StmtResult 2368Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 2369 MultiStmtArg RawHandlers) { 2370 // Don't report an error if 'try' is used in system headers. 2371 if (!getLangOptions().CXXExceptions && 2372 !getSourceManager().isInSystemHeader(TryLoc)) 2373 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 2374 2375 unsigned NumHandlers = RawHandlers.size(); 2376 assert(NumHandlers > 0 && 2377 "The parser shouldn't call this if there are no handlers."); 2378 Stmt **Handlers = RawHandlers.get(); 2379 2380 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 2381 2382 for (unsigned i = 0; i < NumHandlers; ++i) { 2383 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 2384 if (!Handler->getExceptionDecl()) { 2385 if (i < NumHandlers - 1) 2386 return StmtError(Diag(Handler->getLocStart(), 2387 diag::err_early_catch_all)); 2388 2389 continue; 2390 } 2391 2392 const QualType CaughtType = Handler->getCaughtType(); 2393 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 2394 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 2395 } 2396 2397 // Detect handlers for the same type as an earlier one. 2398 if (NumHandlers > 1) { 2399 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 2400 2401 TypeWithHandler prev = TypesWithHandlers[0]; 2402 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 2403 TypeWithHandler curr = TypesWithHandlers[i]; 2404 2405 if (curr == prev) { 2406 Diag(curr.getTypeSpecStartLoc(), 2407 diag::warn_exception_caught_by_earlier_handler) 2408 << curr.getCatchStmt()->getCaughtType().getAsString(); 2409 Diag(prev.getTypeSpecStartLoc(), 2410 diag::note_previous_exception_handler) 2411 << prev.getCatchStmt()->getCaughtType().getAsString(); 2412 } 2413 2414 prev = curr; 2415 } 2416 } 2417 2418 getCurFunction()->setHasBranchProtectedScope(); 2419 2420 // FIXME: We should detect handlers that cannot catch anything because an 2421 // earlier handler catches a superclass. Need to find a method that is not 2422 // quadratic for this. 2423 // Neither of these are explicitly forbidden, but every compiler detects them 2424 // and warns. 2425 2426 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 2427 Handlers, NumHandlers)); 2428} 2429 2430StmtResult 2431Sema::ActOnSEHTryBlock(bool IsCXXTry, 2432 SourceLocation TryLoc, 2433 Stmt *TryBlock, 2434 Stmt *Handler) { 2435 assert(TryBlock && Handler); 2436 2437 getCurFunction()->setHasBranchProtectedScope(); 2438 2439 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 2440} 2441 2442StmtResult 2443Sema::ActOnSEHExceptBlock(SourceLocation Loc, 2444 Expr *FilterExpr, 2445 Stmt *Block) { 2446 assert(FilterExpr && Block); 2447 2448 if(!FilterExpr->getType()->isIntegerType()) { 2449 return StmtError(Diag(FilterExpr->getExprLoc(), 2450 diag::err_filter_expression_integral) 2451 << FilterExpr->getType()); 2452 } 2453 2454 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 2455} 2456 2457StmtResult 2458Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 2459 Stmt *Block) { 2460 assert(Block); 2461 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 2462} 2463