SemaStmt.cpp revision 1093f4928a4263d08b44d96e468a42515d8a28f3
1//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for statements. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Scope.h" 16#include "clang/Sema/ScopeInfo.h" 17#include "clang/Sema/Initialization.h" 18#include "clang/Sema/Lookup.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CharUnits.h" 21#include "clang/AST/DeclObjC.h" 22#include "clang/AST/EvaluatedExprVisitor.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/AST/ExprObjC.h" 25#include "clang/AST/StmtObjC.h" 26#include "clang/AST/StmtCXX.h" 27#include "clang/AST/TypeLoc.h" 28#include "clang/Lex/Preprocessor.h" 29#include "clang/Basic/TargetInfo.h" 30#include "llvm/ADT/ArrayRef.h" 31#include "llvm/ADT/STLExtras.h" 32#include "llvm/ADT/SmallPtrSet.h" 33#include "llvm/ADT/SmallString.h" 34#include "llvm/ADT/SmallVector.h" 35#include "llvm/ADT/Triple.h" 36#include "llvm/MC/MCAsmInfo.h" 37#include "llvm/MC/MCContext.h" 38#include "llvm/MC/MCObjectFileInfo.h" 39#include "llvm/MC/MCRegisterInfo.h" 40#include "llvm/MC/MCStreamer.h" 41#include "llvm/MC/MCSubtargetInfo.h" 42#include "llvm/MC/MCTargetAsmParser.h" 43#include "llvm/MC/MCParser/MCAsmParser.h" 44#include "llvm/Support/SourceMgr.h" 45#include "llvm/Support/TargetRegistry.h" 46#include "llvm/Support/TargetSelect.h" 47using namespace clang; 48using namespace sema; 49 50StmtResult Sema::ActOnExprStmt(FullExprArg expr) { 51 Expr *E = expr.get(); 52 if (!E) // FIXME: FullExprArg has no error state? 53 return StmtError(); 54 55 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 56 // void expression for its side effects. Conversion to void allows any 57 // operand, even incomplete types. 58 59 // Same thing in for stmt first clause (when expr) and third clause. 60 return Owned(static_cast<Stmt*>(E)); 61} 62 63 64StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, 65 bool HasLeadingEmptyMacro) { 66 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); 67} 68 69StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, 70 SourceLocation EndLoc) { 71 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 72 73 // If we have an invalid decl, just return an error. 74 if (DG.isNull()) return StmtError(); 75 76 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 77} 78 79void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { 80 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 81 82 // If we have an invalid decl, just return. 83 if (DG.isNull() || !DG.isSingleDecl()) return; 84 VarDecl *var = cast<VarDecl>(DG.getSingleDecl()); 85 86 // suppress any potential 'unused variable' warning. 87 var->setUsed(); 88 89 // foreach variables are never actually initialized in the way that 90 // the parser came up with. 91 var->setInit(0); 92 93 // In ARC, we don't need to retain the iteration variable of a fast 94 // enumeration loop. Rather than actually trying to catch that 95 // during declaration processing, we remove the consequences here. 96 if (getLangOpts().ObjCAutoRefCount) { 97 QualType type = var->getType(); 98 99 // Only do this if we inferred the lifetime. Inferred lifetime 100 // will show up as a local qualifier because explicit lifetime 101 // should have shown up as an AttributedType instead. 102 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { 103 // Add 'const' and mark the variable as pseudo-strong. 104 var->setType(type.withConst()); 105 var->setARCPseudoStrong(true); 106 } 107 } 108} 109 110/// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. 111/// 112/// Adding a cast to void (or other expression wrappers) will prevent the 113/// warning from firing. 114static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { 115 SourceLocation Loc; 116 bool IsNotEqual, CanAssign; 117 118 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { 119 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) 120 return false; 121 122 Loc = Op->getOperatorLoc(); 123 IsNotEqual = Op->getOpcode() == BO_NE; 124 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); 125 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { 126 if (Op->getOperator() != OO_EqualEqual && 127 Op->getOperator() != OO_ExclaimEqual) 128 return false; 129 130 Loc = Op->getOperatorLoc(); 131 IsNotEqual = Op->getOperator() == OO_ExclaimEqual; 132 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); 133 } else { 134 // Not a typo-prone comparison. 135 return false; 136 } 137 138 // Suppress warnings when the operator, suspicious as it may be, comes from 139 // a macro expansion. 140 if (Loc.isMacroID()) 141 return false; 142 143 S.Diag(Loc, diag::warn_unused_comparison) 144 << (unsigned)IsNotEqual << E->getSourceRange(); 145 146 // If the LHS is a plausible entity to assign to, provide a fixit hint to 147 // correct common typos. 148 if (CanAssign) { 149 if (IsNotEqual) 150 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) 151 << FixItHint::CreateReplacement(Loc, "|="); 152 else 153 S.Diag(Loc, diag::note_equality_comparison_to_assign) 154 << FixItHint::CreateReplacement(Loc, "="); 155 } 156 157 return true; 158} 159 160void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 161 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) 162 return DiagnoseUnusedExprResult(Label->getSubStmt()); 163 164 const Expr *E = dyn_cast_or_null<Expr>(S); 165 if (!E) 166 return; 167 168 const Expr *WarnExpr; 169 SourceLocation Loc; 170 SourceRange R1, R2; 171 if (SourceMgr.isInSystemMacro(E->getExprLoc()) || 172 !E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context)) 173 return; 174 175 // Okay, we have an unused result. Depending on what the base expression is, 176 // we might want to make a more specific diagnostic. Check for one of these 177 // cases now. 178 unsigned DiagID = diag::warn_unused_expr; 179 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) 180 E = Temps->getSubExpr(); 181 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) 182 E = TempExpr->getSubExpr(); 183 184 if (DiagnoseUnusedComparison(*this, E)) 185 return; 186 187 E = WarnExpr; 188 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { 189 if (E->getType()->isVoidType()) 190 return; 191 192 // If the callee has attribute pure, const, or warn_unused_result, warn with 193 // a more specific message to make it clear what is happening. 194 if (const Decl *FD = CE->getCalleeDecl()) { 195 if (FD->getAttr<WarnUnusedResultAttr>()) { 196 Diag(Loc, diag::warn_unused_result) << R1 << R2; 197 return; 198 } 199 if (FD->getAttr<PureAttr>()) { 200 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; 201 return; 202 } 203 if (FD->getAttr<ConstAttr>()) { 204 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; 205 return; 206 } 207 } 208 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { 209 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { 210 Diag(Loc, diag::err_arc_unused_init_message) << R1; 211 return; 212 } 213 const ObjCMethodDecl *MD = ME->getMethodDecl(); 214 if (MD && MD->getAttr<WarnUnusedResultAttr>()) { 215 Diag(Loc, diag::warn_unused_result) << R1 << R2; 216 return; 217 } 218 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 219 const Expr *Source = POE->getSyntacticForm(); 220 if (isa<ObjCSubscriptRefExpr>(Source)) 221 DiagID = diag::warn_unused_container_subscript_expr; 222 else 223 DiagID = diag::warn_unused_property_expr; 224 } else if (const CXXFunctionalCastExpr *FC 225 = dyn_cast<CXXFunctionalCastExpr>(E)) { 226 if (isa<CXXConstructExpr>(FC->getSubExpr()) || 227 isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) 228 return; 229 } 230 // Diagnose "(void*) blah" as a typo for "(void) blah". 231 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { 232 TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); 233 QualType T = TI->getType(); 234 235 // We really do want to use the non-canonical type here. 236 if (T == Context.VoidPtrTy) { 237 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc()); 238 239 Diag(Loc, diag::warn_unused_voidptr) 240 << FixItHint::CreateRemoval(TL.getStarLoc()); 241 return; 242 } 243 } 244 245 if (E->isGLValue() && E->getType().isVolatileQualified()) { 246 Diag(Loc, diag::warn_unused_volatile) << R1 << R2; 247 return; 248 } 249 250 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); 251} 252 253void Sema::ActOnStartOfCompoundStmt() { 254 PushCompoundScope(); 255} 256 257void Sema::ActOnFinishOfCompoundStmt() { 258 PopCompoundScope(); 259} 260 261sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { 262 return getCurFunction()->CompoundScopes.back(); 263} 264 265StmtResult 266Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 267 MultiStmtArg elts, bool isStmtExpr) { 268 unsigned NumElts = elts.size(); 269 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 270 // If we're in C89 mode, check that we don't have any decls after stmts. If 271 // so, emit an extension diagnostic. 272 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { 273 // Note that __extension__ can be around a decl. 274 unsigned i = 0; 275 // Skip over all declarations. 276 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 277 /*empty*/; 278 279 // We found the end of the list or a statement. Scan for another declstmt. 280 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 281 /*empty*/; 282 283 if (i != NumElts) { 284 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 285 Diag(D->getLocation(), diag::ext_mixed_decls_code); 286 } 287 } 288 // Warn about unused expressions in statements. 289 for (unsigned i = 0; i != NumElts; ++i) { 290 // Ignore statements that are last in a statement expression. 291 if (isStmtExpr && i == NumElts - 1) 292 continue; 293 294 DiagnoseUnusedExprResult(Elts[i]); 295 } 296 297 // Check for suspicious empty body (null statement) in `for' and `while' 298 // statements. Don't do anything for template instantiations, this just adds 299 // noise. 300 if (NumElts != 0 && !CurrentInstantiationScope && 301 getCurCompoundScope().HasEmptyLoopBodies) { 302 for (unsigned i = 0; i != NumElts - 1; ++i) 303 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); 304 } 305 306 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 307} 308 309StmtResult 310Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, 311 SourceLocation DotDotDotLoc, Expr *RHSVal, 312 SourceLocation ColonLoc) { 313 assert((LHSVal != 0) && "missing expression in case statement"); 314 315 if (getCurFunction()->SwitchStack.empty()) { 316 Diag(CaseLoc, diag::err_case_not_in_switch); 317 return StmtError(); 318 } 319 320 if (!getLangOpts().CPlusPlus0x) { 321 // C99 6.8.4.2p3: The expression shall be an integer constant. 322 // However, GCC allows any evaluatable integer expression. 323 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { 324 LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); 325 if (!LHSVal) 326 return StmtError(); 327 } 328 329 // GCC extension: The expression shall be an integer constant. 330 331 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { 332 RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); 333 // Recover from an error by just forgetting about it. 334 } 335 } 336 337 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 338 ColonLoc); 339 getCurFunction()->SwitchStack.back()->addSwitchCase(CS); 340 return Owned(CS); 341} 342 343/// ActOnCaseStmtBody - This installs a statement as the body of a case. 344void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { 345 DiagnoseUnusedExprResult(SubStmt); 346 347 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 348 CS->setSubStmt(SubStmt); 349} 350 351StmtResult 352Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 353 Stmt *SubStmt, Scope *CurScope) { 354 DiagnoseUnusedExprResult(SubStmt); 355 356 if (getCurFunction()->SwitchStack.empty()) { 357 Diag(DefaultLoc, diag::err_default_not_in_switch); 358 return Owned(SubStmt); 359 } 360 361 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 362 getCurFunction()->SwitchStack.back()->addSwitchCase(DS); 363 return Owned(DS); 364} 365 366StmtResult 367Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, 368 SourceLocation ColonLoc, Stmt *SubStmt) { 369 // If the label was multiply defined, reject it now. 370 if (TheDecl->getStmt()) { 371 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); 372 Diag(TheDecl->getLocation(), diag::note_previous_definition); 373 return Owned(SubStmt); 374 } 375 376 // Otherwise, things are good. Fill in the declaration and return it. 377 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); 378 TheDecl->setStmt(LS); 379 if (!TheDecl->isGnuLocal()) 380 TheDecl->setLocation(IdentLoc); 381 return Owned(LS); 382} 383 384StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, 385 ArrayRef<const Attr*> Attrs, 386 Stmt *SubStmt) { 387 // Fill in the declaration and return it. 388 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt); 389 return Owned(LS); 390} 391 392StmtResult 393Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, 394 Stmt *thenStmt, SourceLocation ElseLoc, 395 Stmt *elseStmt) { 396 ExprResult CondResult(CondVal.release()); 397 398 VarDecl *ConditionVar = 0; 399 if (CondVar) { 400 ConditionVar = cast<VarDecl>(CondVar); 401 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); 402 if (CondResult.isInvalid()) 403 return StmtError(); 404 } 405 Expr *ConditionExpr = CondResult.takeAs<Expr>(); 406 if (!ConditionExpr) 407 return StmtError(); 408 409 DiagnoseUnusedExprResult(thenStmt); 410 411 if (!elseStmt) { 412 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, 413 diag::warn_empty_if_body); 414 } 415 416 DiagnoseUnusedExprResult(elseStmt); 417 418 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, 419 thenStmt, ElseLoc, elseStmt)); 420} 421 422/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 423/// the specified width and sign. If an overflow occurs, detect it and emit 424/// the specified diagnostic. 425void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 426 unsigned NewWidth, bool NewSign, 427 SourceLocation Loc, 428 unsigned DiagID) { 429 // Perform a conversion to the promoted condition type if needed. 430 if (NewWidth > Val.getBitWidth()) { 431 // If this is an extension, just do it. 432 Val = Val.extend(NewWidth); 433 Val.setIsSigned(NewSign); 434 435 // If the input was signed and negative and the output is 436 // unsigned, don't bother to warn: this is implementation-defined 437 // behavior. 438 // FIXME: Introduce a second, default-ignored warning for this case? 439 } else if (NewWidth < Val.getBitWidth()) { 440 // If this is a truncation, check for overflow. 441 llvm::APSInt ConvVal(Val); 442 ConvVal = ConvVal.trunc(NewWidth); 443 ConvVal.setIsSigned(NewSign); 444 ConvVal = ConvVal.extend(Val.getBitWidth()); 445 ConvVal.setIsSigned(Val.isSigned()); 446 if (ConvVal != Val) 447 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 448 449 // Regardless of whether a diagnostic was emitted, really do the 450 // truncation. 451 Val = Val.trunc(NewWidth); 452 Val.setIsSigned(NewSign); 453 } else if (NewSign != Val.isSigned()) { 454 // Convert the sign to match the sign of the condition. This can cause 455 // overflow as well: unsigned(INTMIN) 456 // We don't diagnose this overflow, because it is implementation-defined 457 // behavior. 458 // FIXME: Introduce a second, default-ignored warning for this case? 459 llvm::APSInt OldVal(Val); 460 Val.setIsSigned(NewSign); 461 } 462} 463 464namespace { 465 struct CaseCompareFunctor { 466 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 467 const llvm::APSInt &RHS) { 468 return LHS.first < RHS; 469 } 470 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 471 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 472 return LHS.first < RHS.first; 473 } 474 bool operator()(const llvm::APSInt &LHS, 475 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 476 return LHS < RHS.first; 477 } 478 }; 479} 480 481/// CmpCaseVals - Comparison predicate for sorting case values. 482/// 483static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 484 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 485 if (lhs.first < rhs.first) 486 return true; 487 488 if (lhs.first == rhs.first && 489 lhs.second->getCaseLoc().getRawEncoding() 490 < rhs.second->getCaseLoc().getRawEncoding()) 491 return true; 492 return false; 493} 494 495/// CmpEnumVals - Comparison predicate for sorting enumeration values. 496/// 497static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 498 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 499{ 500 return lhs.first < rhs.first; 501} 502 503/// EqEnumVals - Comparison preficate for uniqing enumeration values. 504/// 505static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, 506 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) 507{ 508 return lhs.first == rhs.first; 509} 510 511/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of 512/// potentially integral-promoted expression @p expr. 513static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { 514 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) 515 expr = cleanups->getSubExpr(); 516 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { 517 if (impcast->getCastKind() != CK_IntegralCast) break; 518 expr = impcast->getSubExpr(); 519 } 520 return expr->getType(); 521} 522 523StmtResult 524Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, 525 Decl *CondVar) { 526 ExprResult CondResult; 527 528 VarDecl *ConditionVar = 0; 529 if (CondVar) { 530 ConditionVar = cast<VarDecl>(CondVar); 531 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); 532 if (CondResult.isInvalid()) 533 return StmtError(); 534 535 Cond = CondResult.release(); 536 } 537 538 if (!Cond) 539 return StmtError(); 540 541 class SwitchConvertDiagnoser : public ICEConvertDiagnoser { 542 Expr *Cond; 543 544 public: 545 SwitchConvertDiagnoser(Expr *Cond) 546 : ICEConvertDiagnoser(false, true), Cond(Cond) { } 547 548 virtual DiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 549 QualType T) { 550 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T; 551 } 552 553 virtual DiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 554 QualType T) { 555 return S.Diag(Loc, diag::err_switch_incomplete_class_type) 556 << T << Cond->getSourceRange(); 557 } 558 559 virtual DiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 560 QualType T, 561 QualType ConvTy) { 562 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy; 563 } 564 565 virtual DiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 566 QualType ConvTy) { 567 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 568 << ConvTy->isEnumeralType() << ConvTy; 569 } 570 571 virtual DiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 572 QualType T) { 573 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T; 574 } 575 576 virtual DiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 577 QualType ConvTy) { 578 return S.Diag(Conv->getLocation(), diag::note_switch_conversion) 579 << ConvTy->isEnumeralType() << ConvTy; 580 } 581 582 virtual DiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 583 QualType T, 584 QualType ConvTy) { 585 return DiagnosticBuilder::getEmpty(); 586 } 587 } SwitchDiagnoser(Cond); 588 589 CondResult 590 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, SwitchDiagnoser, 591 /*AllowScopedEnumerations*/ true); 592 if (CondResult.isInvalid()) return StmtError(); 593 Cond = CondResult.take(); 594 595 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 596 CondResult = UsualUnaryConversions(Cond); 597 if (CondResult.isInvalid()) return StmtError(); 598 Cond = CondResult.take(); 599 600 if (!CondVar) { 601 CheckImplicitConversions(Cond, SwitchLoc); 602 CondResult = MaybeCreateExprWithCleanups(Cond); 603 if (CondResult.isInvalid()) 604 return StmtError(); 605 Cond = CondResult.take(); 606 } 607 608 getCurFunction()->setHasBranchIntoScope(); 609 610 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); 611 getCurFunction()->SwitchStack.push_back(SS); 612 return Owned(SS); 613} 614 615static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { 616 if (Val.getBitWidth() < BitWidth) 617 Val = Val.extend(BitWidth); 618 else if (Val.getBitWidth() > BitWidth) 619 Val = Val.trunc(BitWidth); 620 Val.setIsSigned(IsSigned); 621} 622 623StmtResult 624Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, 625 Stmt *BodyStmt) { 626 SwitchStmt *SS = cast<SwitchStmt>(Switch); 627 assert(SS == getCurFunction()->SwitchStack.back() && 628 "switch stack missing push/pop!"); 629 630 SS->setBody(BodyStmt, SwitchLoc); 631 getCurFunction()->SwitchStack.pop_back(); 632 633 Expr *CondExpr = SS->getCond(); 634 if (!CondExpr) return StmtError(); 635 636 QualType CondType = CondExpr->getType(); 637 638 Expr *CondExprBeforePromotion = CondExpr; 639 QualType CondTypeBeforePromotion = 640 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); 641 642 // C++ 6.4.2.p2: 643 // Integral promotions are performed (on the switch condition). 644 // 645 // A case value unrepresentable by the original switch condition 646 // type (before the promotion) doesn't make sense, even when it can 647 // be represented by the promoted type. Therefore we need to find 648 // the pre-promotion type of the switch condition. 649 if (!CondExpr->isTypeDependent()) { 650 // We have already converted the expression to an integral or enumeration 651 // type, when we started the switch statement. If we don't have an 652 // appropriate type now, just return an error. 653 if (!CondType->isIntegralOrEnumerationType()) 654 return StmtError(); 655 656 if (CondExpr->isKnownToHaveBooleanValue()) { 657 // switch(bool_expr) {...} is often a programmer error, e.g. 658 // switch(n && mask) { ... } // Doh - should be "n & mask". 659 // One can always use an if statement instead of switch(bool_expr). 660 Diag(SwitchLoc, diag::warn_bool_switch_condition) 661 << CondExpr->getSourceRange(); 662 } 663 } 664 665 // Get the bitwidth of the switched-on value before promotions. We must 666 // convert the integer case values to this width before comparison. 667 bool HasDependentValue 668 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 669 unsigned CondWidth 670 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); 671 bool CondIsSigned 672 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); 673 674 // Accumulate all of the case values in a vector so that we can sort them 675 // and detect duplicates. This vector contains the APInt for the case after 676 // it has been converted to the condition type. 677 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 678 CaseValsTy CaseVals; 679 680 // Keep track of any GNU case ranges we see. The APSInt is the low value. 681 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; 682 CaseRangesTy CaseRanges; 683 684 DefaultStmt *TheDefaultStmt = 0; 685 686 bool CaseListIsErroneous = false; 687 688 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 689 SC = SC->getNextSwitchCase()) { 690 691 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 692 if (TheDefaultStmt) { 693 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 694 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 695 696 // FIXME: Remove the default statement from the switch block so that 697 // we'll return a valid AST. This requires recursing down the AST and 698 // finding it, not something we are set up to do right now. For now, 699 // just lop the entire switch stmt out of the AST. 700 CaseListIsErroneous = true; 701 } 702 TheDefaultStmt = DS; 703 704 } else { 705 CaseStmt *CS = cast<CaseStmt>(SC); 706 707 Expr *Lo = CS->getLHS(); 708 709 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 710 HasDependentValue = true; 711 break; 712 } 713 714 llvm::APSInt LoVal; 715 716 if (getLangOpts().CPlusPlus0x) { 717 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 718 // constant expression of the promoted type of the switch condition. 719 ExprResult ConvLo = 720 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); 721 if (ConvLo.isInvalid()) { 722 CaseListIsErroneous = true; 723 continue; 724 } 725 Lo = ConvLo.take(); 726 } else { 727 // We already verified that the expression has a i-c-e value (C99 728 // 6.8.4.2p3) - get that value now. 729 LoVal = Lo->EvaluateKnownConstInt(Context); 730 731 // If the LHS is not the same type as the condition, insert an implicit 732 // cast. 733 Lo = DefaultLvalueConversion(Lo).take(); 734 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); 735 } 736 737 // Convert the value to the same width/sign as the condition had prior to 738 // integral promotions. 739 // 740 // FIXME: This causes us to reject valid code: 741 // switch ((char)c) { case 256: case 0: return 0; } 742 // Here we claim there is a duplicated condition value, but there is not. 743 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 744 Lo->getLocStart(), 745 diag::warn_case_value_overflow); 746 747 CS->setLHS(Lo); 748 749 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 750 if (CS->getRHS()) { 751 if (CS->getRHS()->isTypeDependent() || 752 CS->getRHS()->isValueDependent()) { 753 HasDependentValue = true; 754 break; 755 } 756 CaseRanges.push_back(std::make_pair(LoVal, CS)); 757 } else 758 CaseVals.push_back(std::make_pair(LoVal, CS)); 759 } 760 } 761 762 if (!HasDependentValue) { 763 // If we don't have a default statement, check whether the 764 // condition is constant. 765 llvm::APSInt ConstantCondValue; 766 bool HasConstantCond = false; 767 if (!HasDependentValue && !TheDefaultStmt) { 768 HasConstantCond 769 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, 770 Expr::SE_AllowSideEffects); 771 assert(!HasConstantCond || 772 (ConstantCondValue.getBitWidth() == CondWidth && 773 ConstantCondValue.isSigned() == CondIsSigned)); 774 } 775 bool ShouldCheckConstantCond = HasConstantCond; 776 777 // Sort all the scalar case values so we can easily detect duplicates. 778 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 779 780 if (!CaseVals.empty()) { 781 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { 782 if (ShouldCheckConstantCond && 783 CaseVals[i].first == ConstantCondValue) 784 ShouldCheckConstantCond = false; 785 786 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { 787 // If we have a duplicate, report it. 788 // First, determine if either case value has a name 789 StringRef PrevString, CurrString; 790 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts(); 791 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts(); 792 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) { 793 PrevString = DeclRef->getDecl()->getName(); 794 } 795 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) { 796 CurrString = DeclRef->getDecl()->getName(); 797 } 798 llvm::SmallString<16> CaseValStr; 799 CaseVals[i-1].first.toString(CaseValStr); 800 801 if (PrevString == CurrString) 802 Diag(CaseVals[i].second->getLHS()->getLocStart(), 803 diag::err_duplicate_case) << 804 (PrevString.empty() ? CaseValStr.str() : PrevString); 805 else 806 Diag(CaseVals[i].second->getLHS()->getLocStart(), 807 diag::err_duplicate_case_differing_expr) << 808 (PrevString.empty() ? CaseValStr.str() : PrevString) << 809 (CurrString.empty() ? CaseValStr.str() : CurrString) << 810 CaseValStr; 811 812 Diag(CaseVals[i-1].second->getLHS()->getLocStart(), 813 diag::note_duplicate_case_prev); 814 // FIXME: We really want to remove the bogus case stmt from the 815 // substmt, but we have no way to do this right now. 816 CaseListIsErroneous = true; 817 } 818 } 819 } 820 821 // Detect duplicate case ranges, which usually don't exist at all in 822 // the first place. 823 if (!CaseRanges.empty()) { 824 // Sort all the case ranges by their low value so we can easily detect 825 // overlaps between ranges. 826 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 827 828 // Scan the ranges, computing the high values and removing empty ranges. 829 std::vector<llvm::APSInt> HiVals; 830 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 831 llvm::APSInt &LoVal = CaseRanges[i].first; 832 CaseStmt *CR = CaseRanges[i].second; 833 Expr *Hi = CR->getRHS(); 834 llvm::APSInt HiVal; 835 836 if (getLangOpts().CPlusPlus0x) { 837 // C++11 [stmt.switch]p2: the constant-expression shall be a converted 838 // constant expression of the promoted type of the switch condition. 839 ExprResult ConvHi = 840 CheckConvertedConstantExpression(Hi, CondType, HiVal, 841 CCEK_CaseValue); 842 if (ConvHi.isInvalid()) { 843 CaseListIsErroneous = true; 844 continue; 845 } 846 Hi = ConvHi.take(); 847 } else { 848 HiVal = Hi->EvaluateKnownConstInt(Context); 849 850 // If the RHS is not the same type as the condition, insert an 851 // implicit cast. 852 Hi = DefaultLvalueConversion(Hi).take(); 853 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); 854 } 855 856 // Convert the value to the same width/sign as the condition. 857 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 858 Hi->getLocStart(), 859 diag::warn_case_value_overflow); 860 861 CR->setRHS(Hi); 862 863 // If the low value is bigger than the high value, the case is empty. 864 if (LoVal > HiVal) { 865 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 866 << SourceRange(CR->getLHS()->getLocStart(), 867 Hi->getLocEnd()); 868 CaseRanges.erase(CaseRanges.begin()+i); 869 --i, --e; 870 continue; 871 } 872 873 if (ShouldCheckConstantCond && 874 LoVal <= ConstantCondValue && 875 ConstantCondValue <= HiVal) 876 ShouldCheckConstantCond = false; 877 878 HiVals.push_back(HiVal); 879 } 880 881 // Rescan the ranges, looking for overlap with singleton values and other 882 // ranges. Since the range list is sorted, we only need to compare case 883 // ranges with their neighbors. 884 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 885 llvm::APSInt &CRLo = CaseRanges[i].first; 886 llvm::APSInt &CRHi = HiVals[i]; 887 CaseStmt *CR = CaseRanges[i].second; 888 889 // Check to see whether the case range overlaps with any 890 // singleton cases. 891 CaseStmt *OverlapStmt = 0; 892 llvm::APSInt OverlapVal(32); 893 894 // Find the smallest value >= the lower bound. If I is in the 895 // case range, then we have overlap. 896 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 897 CaseVals.end(), CRLo, 898 CaseCompareFunctor()); 899 if (I != CaseVals.end() && I->first < CRHi) { 900 OverlapVal = I->first; // Found overlap with scalar. 901 OverlapStmt = I->second; 902 } 903 904 // Find the smallest value bigger than the upper bound. 905 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 906 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 907 OverlapVal = (I-1)->first; // Found overlap with scalar. 908 OverlapStmt = (I-1)->second; 909 } 910 911 // Check to see if this case stmt overlaps with the subsequent 912 // case range. 913 if (i && CRLo <= HiVals[i-1]) { 914 OverlapVal = HiVals[i-1]; // Found overlap with range. 915 OverlapStmt = CaseRanges[i-1].second; 916 } 917 918 if (OverlapStmt) { 919 // If we have a duplicate, report it. 920 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 921 << OverlapVal.toString(10); 922 Diag(OverlapStmt->getLHS()->getLocStart(), 923 diag::note_duplicate_case_prev); 924 // FIXME: We really want to remove the bogus case stmt from the 925 // substmt, but we have no way to do this right now. 926 CaseListIsErroneous = true; 927 } 928 } 929 } 930 931 // Complain if we have a constant condition and we didn't find a match. 932 if (!CaseListIsErroneous && ShouldCheckConstantCond) { 933 // TODO: it would be nice if we printed enums as enums, chars as 934 // chars, etc. 935 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) 936 << ConstantCondValue.toString(10) 937 << CondExpr->getSourceRange(); 938 } 939 940 // Check to see if switch is over an Enum and handles all of its 941 // values. We only issue a warning if there is not 'default:', but 942 // we still do the analysis to preserve this information in the AST 943 // (which can be used by flow-based analyes). 944 // 945 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); 946 947 // If switch has default case, then ignore it. 948 if (!CaseListIsErroneous && !HasConstantCond && ET) { 949 const EnumDecl *ED = ET->getDecl(); 950 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 951 EnumValsTy; 952 EnumValsTy EnumVals; 953 954 // Gather all enum values, set their type and sort them, 955 // allowing easier comparison with CaseVals. 956 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 957 EDI != ED->enumerator_end(); ++EDI) { 958 llvm::APSInt Val = EDI->getInitVal(); 959 AdjustAPSInt(Val, CondWidth, CondIsSigned); 960 EnumVals.push_back(std::make_pair(Val, *EDI)); 961 } 962 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 963 EnumValsTy::iterator EIend = 964 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 965 966 // See which case values aren't in enum. 967 EnumValsTy::const_iterator EI = EnumVals.begin(); 968 for (CaseValsTy::const_iterator CI = CaseVals.begin(); 969 CI != CaseVals.end(); CI++) { 970 while (EI != EIend && EI->first < CI->first) 971 EI++; 972 if (EI == EIend || EI->first > CI->first) 973 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 974 << CondTypeBeforePromotion; 975 } 976 // See which of case ranges aren't in enum 977 EI = EnumVals.begin(); 978 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); 979 RI != CaseRanges.end() && EI != EIend; RI++) { 980 while (EI != EIend && EI->first < RI->first) 981 EI++; 982 983 if (EI == EIend || EI->first != RI->first) { 984 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) 985 << CondTypeBeforePromotion; 986 } 987 988 llvm::APSInt Hi = 989 RI->second->getRHS()->EvaluateKnownConstInt(Context); 990 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 991 while (EI != EIend && EI->first < Hi) 992 EI++; 993 if (EI == EIend || EI->first != Hi) 994 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) 995 << CondTypeBeforePromotion; 996 } 997 998 // Check which enum vals aren't in switch 999 CaseValsTy::const_iterator CI = CaseVals.begin(); 1000 CaseRangesTy::const_iterator RI = CaseRanges.begin(); 1001 bool hasCasesNotInSwitch = false; 1002 1003 SmallVector<DeclarationName,8> UnhandledNames; 1004 1005 for (EI = EnumVals.begin(); EI != EIend; EI++){ 1006 // Drop unneeded case values 1007 llvm::APSInt CIVal; 1008 while (CI != CaseVals.end() && CI->first < EI->first) 1009 CI++; 1010 1011 if (CI != CaseVals.end() && CI->first == EI->first) 1012 continue; 1013 1014 // Drop unneeded case ranges 1015 for (; RI != CaseRanges.end(); RI++) { 1016 llvm::APSInt Hi = 1017 RI->second->getRHS()->EvaluateKnownConstInt(Context); 1018 AdjustAPSInt(Hi, CondWidth, CondIsSigned); 1019 if (EI->first <= Hi) 1020 break; 1021 } 1022 1023 if (RI == CaseRanges.end() || EI->first < RI->first) { 1024 hasCasesNotInSwitch = true; 1025 UnhandledNames.push_back(EI->second->getDeclName()); 1026 } 1027 } 1028 1029 if (TheDefaultStmt && UnhandledNames.empty()) 1030 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); 1031 1032 // Produce a nice diagnostic if multiple values aren't handled. 1033 switch (UnhandledNames.size()) { 1034 case 0: break; 1035 case 1: 1036 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1037 ? diag::warn_def_missing_case1 : diag::warn_missing_case1) 1038 << UnhandledNames[0]; 1039 break; 1040 case 2: 1041 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1042 ? diag::warn_def_missing_case2 : diag::warn_missing_case2) 1043 << UnhandledNames[0] << UnhandledNames[1]; 1044 break; 1045 case 3: 1046 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1047 ? diag::warn_def_missing_case3 : diag::warn_missing_case3) 1048 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1049 break; 1050 default: 1051 Diag(CondExpr->getExprLoc(), TheDefaultStmt 1052 ? diag::warn_def_missing_cases : diag::warn_missing_cases) 1053 << (unsigned)UnhandledNames.size() 1054 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; 1055 break; 1056 } 1057 1058 if (!hasCasesNotInSwitch) 1059 SS->setAllEnumCasesCovered(); 1060 } 1061 } 1062 1063 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, 1064 diag::warn_empty_switch_body); 1065 1066 // FIXME: If the case list was broken is some way, we don't have a good system 1067 // to patch it up. Instead, just return the whole substmt as broken. 1068 if (CaseListIsErroneous) 1069 return StmtError(); 1070 1071 return Owned(SS); 1072} 1073 1074void 1075Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, 1076 Expr *SrcExpr) { 1077 unsigned DIAG = diag::warn_not_in_enum_assignement; 1078 if (Diags.getDiagnosticLevel(DIAG, SrcExpr->getExprLoc()) 1079 == DiagnosticsEngine::Ignored) 1080 return; 1081 1082 if (const EnumType *ET = DstType->getAs<EnumType>()) 1083 if (!Context.hasSameType(SrcType, DstType) && 1084 SrcType->isIntegerType()) { 1085 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() && 1086 SrcExpr->isIntegerConstantExpr(Context)) { 1087 // Get the bitwidth of the enum value before promotions. 1088 unsigned DstWith = Context.getIntWidth(DstType); 1089 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType(); 1090 1091 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context); 1092 const EnumDecl *ED = ET->getDecl(); 1093 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> 1094 EnumValsTy; 1095 EnumValsTy EnumVals; 1096 1097 // Gather all enum values, set their type and sort them, 1098 // allowing easier comparison with rhs constant. 1099 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); 1100 EDI != ED->enumerator_end(); ++EDI) { 1101 llvm::APSInt Val = EDI->getInitVal(); 1102 AdjustAPSInt(Val, DstWith, DstIsSigned); 1103 EnumVals.push_back(std::make_pair(Val, *EDI)); 1104 } 1105 if (EnumVals.empty()) 1106 return; 1107 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); 1108 EnumValsTy::iterator EIend = 1109 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); 1110 1111 // See which case values aren't in enum. 1112 EnumValsTy::const_iterator EI = EnumVals.begin(); 1113 while (EI != EIend && EI->first < RhsVal) 1114 EI++; 1115 if (EI == EIend || EI->first != RhsVal) { 1116 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignement) 1117 << DstType; 1118 } 1119 } 1120 } 1121} 1122 1123StmtResult 1124Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, 1125 Decl *CondVar, Stmt *Body) { 1126 ExprResult CondResult(Cond.release()); 1127 1128 VarDecl *ConditionVar = 0; 1129 if (CondVar) { 1130 ConditionVar = cast<VarDecl>(CondVar); 1131 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); 1132 if (CondResult.isInvalid()) 1133 return StmtError(); 1134 } 1135 Expr *ConditionExpr = CondResult.take(); 1136 if (!ConditionExpr) 1137 return StmtError(); 1138 1139 DiagnoseUnusedExprResult(Body); 1140 1141 if (isa<NullStmt>(Body)) 1142 getCurCompoundScope().setHasEmptyLoopBodies(); 1143 1144 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, 1145 Body, WhileLoc)); 1146} 1147 1148StmtResult 1149Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, 1150 SourceLocation WhileLoc, SourceLocation CondLParen, 1151 Expr *Cond, SourceLocation CondRParen) { 1152 assert(Cond && "ActOnDoStmt(): missing expression"); 1153 1154 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); 1155 if (CondResult.isInvalid() || CondResult.isInvalid()) 1156 return StmtError(); 1157 Cond = CondResult.take(); 1158 1159 CheckImplicitConversions(Cond, DoLoc); 1160 CondResult = MaybeCreateExprWithCleanups(Cond); 1161 if (CondResult.isInvalid()) 1162 return StmtError(); 1163 Cond = CondResult.take(); 1164 1165 DiagnoseUnusedExprResult(Body); 1166 1167 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); 1168} 1169 1170namespace { 1171 // This visitor will traverse a conditional statement and store all 1172 // the evaluated decls into a vector. Simple is set to true if none 1173 // of the excluded constructs are used. 1174 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { 1175 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1176 llvm::SmallVector<SourceRange, 10> &Ranges; 1177 bool Simple; 1178public: 1179 typedef EvaluatedExprVisitor<DeclExtractor> Inherited; 1180 1181 DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, 1182 llvm::SmallVector<SourceRange, 10> &Ranges) : 1183 Inherited(S.Context), 1184 Decls(Decls), 1185 Ranges(Ranges), 1186 Simple(true) {} 1187 1188 bool isSimple() { return Simple; } 1189 1190 // Replaces the method in EvaluatedExprVisitor. 1191 void VisitMemberExpr(MemberExpr* E) { 1192 Simple = false; 1193 } 1194 1195 // Any Stmt not whitelisted will cause the condition to be marked complex. 1196 void VisitStmt(Stmt *S) { 1197 Simple = false; 1198 } 1199 1200 void VisitBinaryOperator(BinaryOperator *E) { 1201 Visit(E->getLHS()); 1202 Visit(E->getRHS()); 1203 } 1204 1205 void VisitCastExpr(CastExpr *E) { 1206 Visit(E->getSubExpr()); 1207 } 1208 1209 void VisitUnaryOperator(UnaryOperator *E) { 1210 // Skip checking conditionals with derefernces. 1211 if (E->getOpcode() == UO_Deref) 1212 Simple = false; 1213 else 1214 Visit(E->getSubExpr()); 1215 } 1216 1217 void VisitConditionalOperator(ConditionalOperator *E) { 1218 Visit(E->getCond()); 1219 Visit(E->getTrueExpr()); 1220 Visit(E->getFalseExpr()); 1221 } 1222 1223 void VisitParenExpr(ParenExpr *E) { 1224 Visit(E->getSubExpr()); 1225 } 1226 1227 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { 1228 Visit(E->getOpaqueValue()->getSourceExpr()); 1229 Visit(E->getFalseExpr()); 1230 } 1231 1232 void VisitIntegerLiteral(IntegerLiteral *E) { } 1233 void VisitFloatingLiteral(FloatingLiteral *E) { } 1234 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } 1235 void VisitCharacterLiteral(CharacterLiteral *E) { } 1236 void VisitGNUNullExpr(GNUNullExpr *E) { } 1237 void VisitImaginaryLiteral(ImaginaryLiteral *E) { } 1238 1239 void VisitDeclRefExpr(DeclRefExpr *E) { 1240 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); 1241 if (!VD) return; 1242 1243 Ranges.push_back(E->getSourceRange()); 1244 1245 Decls.insert(VD); 1246 } 1247 1248 }; // end class DeclExtractor 1249 1250 // DeclMatcher checks to see if the decls are used in a non-evauluated 1251 // context. 1252 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { 1253 llvm::SmallPtrSet<VarDecl*, 8> &Decls; 1254 bool FoundDecl; 1255 1256public: 1257 typedef EvaluatedExprVisitor<DeclMatcher> Inherited; 1258 1259 DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, Stmt *Statement) : 1260 Inherited(S.Context), Decls(Decls), FoundDecl(false) { 1261 if (!Statement) return; 1262 1263 Visit(Statement); 1264 } 1265 1266 void VisitReturnStmt(ReturnStmt *S) { 1267 FoundDecl = true; 1268 } 1269 1270 void VisitBreakStmt(BreakStmt *S) { 1271 FoundDecl = true; 1272 } 1273 1274 void VisitGotoStmt(GotoStmt *S) { 1275 FoundDecl = true; 1276 } 1277 1278 void VisitCastExpr(CastExpr *E) { 1279 if (E->getCastKind() == CK_LValueToRValue) 1280 CheckLValueToRValueCast(E->getSubExpr()); 1281 else 1282 Visit(E->getSubExpr()); 1283 } 1284 1285 void CheckLValueToRValueCast(Expr *E) { 1286 E = E->IgnoreParenImpCasts(); 1287 1288 if (isa<DeclRefExpr>(E)) { 1289 return; 1290 } 1291 1292 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 1293 Visit(CO->getCond()); 1294 CheckLValueToRValueCast(CO->getTrueExpr()); 1295 CheckLValueToRValueCast(CO->getFalseExpr()); 1296 return; 1297 } 1298 1299 if (BinaryConditionalOperator *BCO = 1300 dyn_cast<BinaryConditionalOperator>(E)) { 1301 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); 1302 CheckLValueToRValueCast(BCO->getFalseExpr()); 1303 return; 1304 } 1305 1306 Visit(E); 1307 } 1308 1309 void VisitDeclRefExpr(DeclRefExpr *E) { 1310 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) 1311 if (Decls.count(VD)) 1312 FoundDecl = true; 1313 } 1314 1315 bool FoundDeclInUse() { return FoundDecl; } 1316 1317 }; // end class DeclMatcher 1318 1319 void CheckForLoopConditionalStatement(Sema &S, Expr *Second, 1320 Expr *Third, Stmt *Body) { 1321 // Condition is empty 1322 if (!Second) return; 1323 1324 if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body, 1325 Second->getLocStart()) 1326 == DiagnosticsEngine::Ignored) 1327 return; 1328 1329 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); 1330 llvm::SmallPtrSet<VarDecl*, 8> Decls; 1331 llvm::SmallVector<SourceRange, 10> Ranges; 1332 DeclExtractor DE(S, Decls, Ranges); 1333 DE.Visit(Second); 1334 1335 // Don't analyze complex conditionals. 1336 if (!DE.isSimple()) return; 1337 1338 // No decls found. 1339 if (Decls.size() == 0) return; 1340 1341 // Don't warn on volatile, static, or global variables. 1342 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1343 E = Decls.end(); 1344 I != E; ++I) 1345 if ((*I)->getType().isVolatileQualified() || 1346 (*I)->hasGlobalStorage()) return; 1347 1348 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || 1349 DeclMatcher(S, Decls, Third).FoundDeclInUse() || 1350 DeclMatcher(S, Decls, Body).FoundDeclInUse()) 1351 return; 1352 1353 // Load decl names into diagnostic. 1354 if (Decls.size() > 4) 1355 PDiag << 0; 1356 else { 1357 PDiag << Decls.size(); 1358 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), 1359 E = Decls.end(); 1360 I != E; ++I) 1361 PDiag << (*I)->getDeclName(); 1362 } 1363 1364 // Load SourceRanges into diagnostic if there is room. 1365 // Otherwise, load the SourceRange of the conditional expression. 1366 if (Ranges.size() <= PartialDiagnostic::MaxArguments) 1367 for (llvm::SmallVector<SourceRange, 10>::iterator I = Ranges.begin(), 1368 E = Ranges.end(); 1369 I != E; ++I) 1370 PDiag << *I; 1371 else 1372 PDiag << Second->getSourceRange(); 1373 1374 S.Diag(Ranges.begin()->getBegin(), PDiag); 1375 } 1376 1377} // end namespace 1378 1379StmtResult 1380Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1381 Stmt *First, FullExprArg second, Decl *secondVar, 1382 FullExprArg third, 1383 SourceLocation RParenLoc, Stmt *Body) { 1384 if (!getLangOpts().CPlusPlus) { 1385 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 1386 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1387 // declare identifiers for objects having storage class 'auto' or 1388 // 'register'. 1389 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 1390 DI!=DE; ++DI) { 1391 VarDecl *VD = dyn_cast<VarDecl>(*DI); 1392 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) 1393 VD = 0; 1394 if (VD == 0) 1395 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 1396 // FIXME: mark decl erroneous! 1397 } 1398 } 1399 } 1400 1401 CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body); 1402 1403 ExprResult SecondResult(second.release()); 1404 VarDecl *ConditionVar = 0; 1405 if (secondVar) { 1406 ConditionVar = cast<VarDecl>(secondVar); 1407 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); 1408 if (SecondResult.isInvalid()) 1409 return StmtError(); 1410 } 1411 1412 Expr *Third = third.release().takeAs<Expr>(); 1413 1414 DiagnoseUnusedExprResult(First); 1415 DiagnoseUnusedExprResult(Third); 1416 DiagnoseUnusedExprResult(Body); 1417 1418 if (isa<NullStmt>(Body)) 1419 getCurCompoundScope().setHasEmptyLoopBodies(); 1420 1421 return Owned(new (Context) ForStmt(Context, First, 1422 SecondResult.take(), ConditionVar, 1423 Third, Body, ForLoc, LParenLoc, 1424 RParenLoc)); 1425} 1426 1427/// In an Objective C collection iteration statement: 1428/// for (x in y) 1429/// x can be an arbitrary l-value expression. Bind it up as a 1430/// full-expression. 1431StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { 1432 // Reduce placeholder expressions here. Note that this rejects the 1433 // use of pseudo-object l-values in this position. 1434 ExprResult result = CheckPlaceholderExpr(E); 1435 if (result.isInvalid()) return StmtError(); 1436 E = result.take(); 1437 1438 CheckImplicitConversions(E); 1439 1440 result = MaybeCreateExprWithCleanups(E); 1441 if (result.isInvalid()) return StmtError(); 1442 1443 return Owned(static_cast<Stmt*>(result.take())); 1444} 1445 1446ExprResult 1447Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { 1448 if (!collection) 1449 return ExprError(); 1450 1451 // Bail out early if we've got a type-dependent expression. 1452 if (collection->isTypeDependent()) return Owned(collection); 1453 1454 // Perform normal l-value conversion. 1455 ExprResult result = DefaultFunctionArrayLvalueConversion(collection); 1456 if (result.isInvalid()) 1457 return ExprError(); 1458 collection = result.take(); 1459 1460 // The operand needs to have object-pointer type. 1461 // TODO: should we do a contextual conversion? 1462 const ObjCObjectPointerType *pointerType = 1463 collection->getType()->getAs<ObjCObjectPointerType>(); 1464 if (!pointerType) 1465 return Diag(forLoc, diag::err_collection_expr_type) 1466 << collection->getType() << collection->getSourceRange(); 1467 1468 // Check that the operand provides 1469 // - countByEnumeratingWithState:objects:count: 1470 const ObjCObjectType *objectType = pointerType->getObjectType(); 1471 ObjCInterfaceDecl *iface = objectType->getInterface(); 1472 1473 // If we have a forward-declared type, we can't do this check. 1474 // Under ARC, it is an error not to have a forward-declared class. 1475 if (iface && 1476 RequireCompleteType(forLoc, QualType(objectType, 0), 1477 getLangOpts().ObjCAutoRefCount 1478 ? diag::err_arc_collection_forward 1479 : 0, 1480 collection)) { 1481 // Otherwise, if we have any useful type information, check that 1482 // the type declares the appropriate method. 1483 } else if (iface || !objectType->qual_empty()) { 1484 IdentifierInfo *selectorIdents[] = { 1485 &Context.Idents.get("countByEnumeratingWithState"), 1486 &Context.Idents.get("objects"), 1487 &Context.Idents.get("count") 1488 }; 1489 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); 1490 1491 ObjCMethodDecl *method = 0; 1492 1493 // If there's an interface, look in both the public and private APIs. 1494 if (iface) { 1495 method = iface->lookupInstanceMethod(selector); 1496 if (!method) method = iface->lookupPrivateMethod(selector); 1497 } 1498 1499 // Also check protocol qualifiers. 1500 if (!method) 1501 method = LookupMethodInQualifiedType(selector, pointerType, 1502 /*instance*/ true); 1503 1504 // If we didn't find it anywhere, give up. 1505 if (!method) { 1506 Diag(forLoc, diag::warn_collection_expr_type) 1507 << collection->getType() << selector << collection->getSourceRange(); 1508 } 1509 1510 // TODO: check for an incompatible signature? 1511 } 1512 1513 // Wrap up any cleanups in the expression. 1514 return Owned(MaybeCreateExprWithCleanups(collection)); 1515} 1516 1517StmtResult 1518Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 1519 SourceLocation LParenLoc, 1520 Stmt *First, Expr *collection, 1521 SourceLocation RParenLoc) { 1522 1523 ExprResult CollectionExprResult = 1524 CheckObjCForCollectionOperand(ForLoc, collection); 1525 1526 if (First) { 1527 QualType FirstType; 1528 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 1529 if (!DS->isSingleDecl()) 1530 return StmtError(Diag((*DS->decl_begin())->getLocation(), 1531 diag::err_toomany_element_decls)); 1532 1533 VarDecl *D = cast<VarDecl>(DS->getSingleDecl()); 1534 FirstType = D->getType(); 1535 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 1536 // declare identifiers for objects having storage class 'auto' or 1537 // 'register'. 1538 if (!D->hasLocalStorage()) 1539 return StmtError(Diag(D->getLocation(), 1540 diag::err_non_variable_decl_in_for)); 1541 } else { 1542 Expr *FirstE = cast<Expr>(First); 1543 if (!FirstE->isTypeDependent() && !FirstE->isLValue()) 1544 return StmtError(Diag(First->getLocStart(), 1545 diag::err_selector_element_not_lvalue) 1546 << First->getSourceRange()); 1547 1548 FirstType = static_cast<Expr*>(First)->getType(); 1549 } 1550 if (!FirstType->isDependentType() && 1551 !FirstType->isObjCObjectPointerType() && 1552 !FirstType->isBlockPointerType()) 1553 return StmtError(Diag(ForLoc, diag::err_selector_element_type) 1554 << FirstType << First->getSourceRange()); 1555 } 1556 1557 if (CollectionExprResult.isInvalid()) 1558 return StmtError(); 1559 1560 return Owned(new (Context) ObjCForCollectionStmt(First, 1561 CollectionExprResult.take(), 0, 1562 ForLoc, RParenLoc)); 1563} 1564 1565namespace { 1566 1567enum BeginEndFunction { 1568 BEF_begin, 1569 BEF_end 1570}; 1571 1572/// Build a variable declaration for a for-range statement. 1573static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, 1574 QualType Type, const char *Name) { 1575 DeclContext *DC = SemaRef.CurContext; 1576 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); 1577 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); 1578 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, 1579 TInfo, SC_Auto, SC_None); 1580 Decl->setImplicit(); 1581 return Decl; 1582} 1583 1584/// Finish building a variable declaration for a for-range statement. 1585/// \return true if an error occurs. 1586static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, 1587 SourceLocation Loc, int diag) { 1588 // Deduce the type for the iterator variable now rather than leaving it to 1589 // AddInitializerToDecl, so we can produce a more suitable diagnostic. 1590 TypeSourceInfo *InitTSI = 0; 1591 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || 1592 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) == 1593 Sema::DAR_Failed) 1594 SemaRef.Diag(Loc, diag) << Init->getType(); 1595 if (!InitTSI) { 1596 Decl->setInvalidDecl(); 1597 return true; 1598 } 1599 Decl->setTypeSourceInfo(InitTSI); 1600 Decl->setType(InitTSI->getType()); 1601 1602 // In ARC, infer lifetime. 1603 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if 1604 // we're doing the equivalent of fast iteration. 1605 if (SemaRef.getLangOpts().ObjCAutoRefCount && 1606 SemaRef.inferObjCARCLifetime(Decl)) 1607 Decl->setInvalidDecl(); 1608 1609 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, 1610 /*TypeMayContainAuto=*/false); 1611 SemaRef.FinalizeDeclaration(Decl); 1612 SemaRef.CurContext->addHiddenDecl(Decl); 1613 return false; 1614} 1615 1616/// Produce a note indicating which begin/end function was implicitly called 1617/// by a C++0x for-range statement. This is often not obvious from the code, 1618/// nor from the diagnostics produced when analysing the implicit expressions 1619/// required in a for-range statement. 1620void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, 1621 BeginEndFunction BEF) { 1622 CallExpr *CE = dyn_cast<CallExpr>(E); 1623 if (!CE) 1624 return; 1625 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); 1626 if (!D) 1627 return; 1628 SourceLocation Loc = D->getLocation(); 1629 1630 std::string Description; 1631 bool IsTemplate = false; 1632 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { 1633 Description = SemaRef.getTemplateArgumentBindingsText( 1634 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); 1635 IsTemplate = true; 1636 } 1637 1638 SemaRef.Diag(Loc, diag::note_for_range_begin_end) 1639 << BEF << IsTemplate << Description << E->getType(); 1640} 1641 1642/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the 1643/// given LookupResult is non-empty, it is assumed to describe a member which 1644/// will be invoked. Otherwise, the function will be found via argument 1645/// dependent lookup. 1646static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, 1647 SourceLocation Loc, 1648 VarDecl *Decl, 1649 BeginEndFunction BEF, 1650 const DeclarationNameInfo &NameInfo, 1651 LookupResult &MemberLookup, 1652 Expr *Range) { 1653 ExprResult CallExpr; 1654 if (!MemberLookup.empty()) { 1655 ExprResult MemberRef = 1656 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, 1657 /*IsPtr=*/false, CXXScopeSpec(), 1658 /*TemplateKWLoc=*/SourceLocation(), 1659 /*FirstQualifierInScope=*/0, 1660 MemberLookup, 1661 /*TemplateArgs=*/0); 1662 if (MemberRef.isInvalid()) 1663 return ExprError(); 1664 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), 1665 Loc, 0); 1666 if (CallExpr.isInvalid()) 1667 return ExprError(); 1668 } else { 1669 UnresolvedSet<0> FoundNames; 1670 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace 1671 // std is an associated namespace. 1672 UnresolvedLookupExpr *Fn = 1673 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, 1674 NestedNameSpecifierLoc(), NameInfo, 1675 /*NeedsADL=*/true, /*Overloaded=*/false, 1676 FoundNames.begin(), FoundNames.end(), 1677 /*LookInStdNamespace=*/true); 1678 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, 1679 0, /*AllowTypoCorrection=*/false); 1680 if (CallExpr.isInvalid()) { 1681 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) 1682 << Range->getType(); 1683 return ExprError(); 1684 } 1685 } 1686 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, 1687 diag::err_for_range_iter_deduction_failure)) { 1688 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); 1689 return ExprError(); 1690 } 1691 return CallExpr; 1692} 1693 1694} 1695 1696static bool ObjCEnumerationCollection(Expr *Collection) { 1697 return !Collection->isTypeDependent() 1698 && Collection->getType()->getAs<ObjCObjectPointerType>() != 0; 1699} 1700 1701/// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement. 1702/// 1703/// C++0x [stmt.ranged]: 1704/// A range-based for statement is equivalent to 1705/// 1706/// { 1707/// auto && __range = range-init; 1708/// for ( auto __begin = begin-expr, 1709/// __end = end-expr; 1710/// __begin != __end; 1711/// ++__begin ) { 1712/// for-range-declaration = *__begin; 1713/// statement 1714/// } 1715/// } 1716/// 1717/// The body of the loop is not available yet, since it cannot be analysed until 1718/// we have determined the type of the for-range-declaration. 1719StmtResult 1720Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 1721 Stmt *First, SourceLocation ColonLoc, Expr *Range, 1722 SourceLocation RParenLoc) { 1723 if (!First || !Range) 1724 return StmtError(); 1725 1726 if (ObjCEnumerationCollection(Range)) 1727 return ActOnObjCForCollectionStmt(ForLoc, LParenLoc, First, Range, 1728 RParenLoc); 1729 1730 DeclStmt *DS = dyn_cast<DeclStmt>(First); 1731 assert(DS && "first part of for range not a decl stmt"); 1732 1733 if (!DS->isSingleDecl()) { 1734 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); 1735 return StmtError(); 1736 } 1737 if (DS->getSingleDecl()->isInvalidDecl()) 1738 return StmtError(); 1739 1740 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) 1741 return StmtError(); 1742 1743 // Build auto && __range = range-init 1744 SourceLocation RangeLoc = Range->getLocStart(); 1745 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, 1746 Context.getAutoRRefDeductType(), 1747 "__range"); 1748 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, 1749 diag::err_for_range_deduction_failure)) 1750 return StmtError(); 1751 1752 // Claim the type doesn't contain auto: we've already done the checking. 1753 DeclGroupPtrTy RangeGroup = 1754 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false); 1755 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); 1756 if (RangeDecl.isInvalid()) 1757 return StmtError(); 1758 1759 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), 1760 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, 1761 RParenLoc); 1762} 1763 1764/// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. 1765StmtResult 1766Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, 1767 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, 1768 Expr *Inc, Stmt *LoopVarDecl, 1769 SourceLocation RParenLoc) { 1770 Scope *S = getCurScope(); 1771 1772 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); 1773 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); 1774 QualType RangeVarType = RangeVar->getType(); 1775 1776 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); 1777 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); 1778 1779 StmtResult BeginEndDecl = BeginEnd; 1780 ExprResult NotEqExpr = Cond, IncrExpr = Inc; 1781 1782 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) { 1783 SourceLocation RangeLoc = RangeVar->getLocation(); 1784 1785 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); 1786 1787 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1788 VK_LValue, ColonLoc); 1789 if (BeginRangeRef.isInvalid()) 1790 return StmtError(); 1791 1792 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, 1793 VK_LValue, ColonLoc); 1794 if (EndRangeRef.isInvalid()) 1795 return StmtError(); 1796 1797 QualType AutoType = Context.getAutoDeductType(); 1798 Expr *Range = RangeVar->getInit(); 1799 if (!Range) 1800 return StmtError(); 1801 QualType RangeType = Range->getType(); 1802 1803 if (RequireCompleteType(RangeLoc, RangeType, 1804 diag::err_for_range_incomplete_type)) 1805 return StmtError(); 1806 1807 // Build auto __begin = begin-expr, __end = end-expr. 1808 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1809 "__begin"); 1810 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, 1811 "__end"); 1812 1813 // Build begin-expr and end-expr and attach to __begin and __end variables. 1814 ExprResult BeginExpr, EndExpr; 1815 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { 1816 // - if _RangeT is an array type, begin-expr and end-expr are __range and 1817 // __range + __bound, respectively, where __bound is the array bound. If 1818 // _RangeT is an array of unknown size or an array of incomplete type, 1819 // the program is ill-formed; 1820 1821 // begin-expr is __range. 1822 BeginExpr = BeginRangeRef; 1823 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, 1824 diag::err_for_range_iter_deduction_failure)) { 1825 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1826 return StmtError(); 1827 } 1828 1829 // Find the array bound. 1830 ExprResult BoundExpr; 1831 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) 1832 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), 1833 Context.getPointerDiffType(), 1834 RangeLoc)); 1835 else if (const VariableArrayType *VAT = 1836 dyn_cast<VariableArrayType>(UnqAT)) 1837 BoundExpr = VAT->getSizeExpr(); 1838 else { 1839 // Can't be a DependentSizedArrayType or an IncompleteArrayType since 1840 // UnqAT is not incomplete and Range is not type-dependent. 1841 llvm_unreachable("Unexpected array type in for-range"); 1842 } 1843 1844 // end-expr is __range + __bound. 1845 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), 1846 BoundExpr.get()); 1847 if (EndExpr.isInvalid()) 1848 return StmtError(); 1849 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, 1850 diag::err_for_range_iter_deduction_failure)) { 1851 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1852 return StmtError(); 1853 } 1854 } else { 1855 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), 1856 ColonLoc); 1857 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), 1858 ColonLoc); 1859 1860 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); 1861 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); 1862 1863 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { 1864 // - if _RangeT is a class type, the unqualified-ids begin and end are 1865 // looked up in the scope of class _RangeT as if by class member access 1866 // lookup (3.4.5), and if either (or both) finds at least one 1867 // declaration, begin-expr and end-expr are __range.begin() and 1868 // __range.end(), respectively; 1869 LookupQualifiedName(BeginMemberLookup, D); 1870 LookupQualifiedName(EndMemberLookup, D); 1871 1872 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { 1873 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) 1874 << RangeType << BeginMemberLookup.empty(); 1875 return StmtError(); 1876 } 1877 } else { 1878 // - otherwise, begin-expr and end-expr are begin(__range) and 1879 // end(__range), respectively, where begin and end are looked up with 1880 // argument-dependent lookup (3.4.2). For the purposes of this name 1881 // lookup, namespace std is an associated namespace. 1882 } 1883 1884 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, 1885 BEF_begin, BeginNameInfo, 1886 BeginMemberLookup, 1887 BeginRangeRef.get()); 1888 if (BeginExpr.isInvalid()) 1889 return StmtError(); 1890 1891 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, 1892 BEF_end, EndNameInfo, 1893 EndMemberLookup, EndRangeRef.get()); 1894 if (EndExpr.isInvalid()) 1895 return StmtError(); 1896 } 1897 1898 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. 1899 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); 1900 if (!Context.hasSameType(BeginType, EndType)) { 1901 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) 1902 << BeginType << EndType; 1903 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1904 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1905 } 1906 1907 Decl *BeginEndDecls[] = { BeginVar, EndVar }; 1908 // Claim the type doesn't contain auto: we've already done the checking. 1909 DeclGroupPtrTy BeginEndGroup = 1910 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false); 1911 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); 1912 1913 const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); 1914 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1915 VK_LValue, ColonLoc); 1916 if (BeginRef.isInvalid()) 1917 return StmtError(); 1918 1919 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), 1920 VK_LValue, ColonLoc); 1921 if (EndRef.isInvalid()) 1922 return StmtError(); 1923 1924 // Build and check __begin != __end expression. 1925 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, 1926 BeginRef.get(), EndRef.get()); 1927 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); 1928 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); 1929 if (NotEqExpr.isInvalid()) { 1930 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1931 if (!Context.hasSameType(BeginType, EndType)) 1932 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); 1933 return StmtError(); 1934 } 1935 1936 // Build and check ++__begin expression. 1937 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1938 VK_LValue, ColonLoc); 1939 if (BeginRef.isInvalid()) 1940 return StmtError(); 1941 1942 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); 1943 IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); 1944 if (IncrExpr.isInvalid()) { 1945 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1946 return StmtError(); 1947 } 1948 1949 // Build and check *__begin expression. 1950 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, 1951 VK_LValue, ColonLoc); 1952 if (BeginRef.isInvalid()) 1953 return StmtError(); 1954 1955 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); 1956 if (DerefExpr.isInvalid()) { 1957 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1958 return StmtError(); 1959 } 1960 1961 // Attach *__begin as initializer for VD. 1962 if (!LoopVar->isInvalidDecl()) { 1963 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, 1964 /*TypeMayContainAuto=*/true); 1965 if (LoopVar->isInvalidDecl()) 1966 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); 1967 } 1968 } else { 1969 // The range is implicitly used as a placeholder when it is dependent. 1970 RangeVar->setUsed(); 1971 } 1972 1973 return Owned(new (Context) CXXForRangeStmt(RangeDS, 1974 cast_or_null<DeclStmt>(BeginEndDecl.get()), 1975 NotEqExpr.take(), IncrExpr.take(), 1976 LoopVarDS, /*Body=*/0, ForLoc, 1977 ColonLoc, RParenLoc)); 1978} 1979 1980/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach 1981/// statement. 1982StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) { 1983 if (!S || !B) 1984 return StmtError(); 1985 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S); 1986 1987 ForStmt->setBody(B); 1988 return S; 1989} 1990 1991/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. 1992/// This is a separate step from ActOnCXXForRangeStmt because analysis of the 1993/// body cannot be performed until after the type of the range variable is 1994/// determined. 1995StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { 1996 if (!S || !B) 1997 return StmtError(); 1998 1999 if (isa<ObjCForCollectionStmt>(S)) 2000 return FinishObjCForCollectionStmt(S, B); 2001 2002 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); 2003 ForStmt->setBody(B); 2004 2005 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, 2006 diag::warn_empty_range_based_for_body); 2007 2008 return S; 2009} 2010 2011StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, 2012 SourceLocation LabelLoc, 2013 LabelDecl *TheDecl) { 2014 getCurFunction()->setHasBranchIntoScope(); 2015 TheDecl->setUsed(); 2016 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); 2017} 2018 2019StmtResult 2020Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 2021 Expr *E) { 2022 // Convert operand to void* 2023 if (!E->isTypeDependent()) { 2024 QualType ETy = E->getType(); 2025 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); 2026 ExprResult ExprRes = Owned(E); 2027 AssignConvertType ConvTy = 2028 CheckSingleAssignmentConstraints(DestTy, ExprRes); 2029 if (ExprRes.isInvalid()) 2030 return StmtError(); 2031 E = ExprRes.take(); 2032 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) 2033 return StmtError(); 2034 E = MaybeCreateExprWithCleanups(E); 2035 } 2036 2037 getCurFunction()->setHasIndirectGoto(); 2038 2039 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 2040} 2041 2042StmtResult 2043Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 2044 Scope *S = CurScope->getContinueParent(); 2045 if (!S) { 2046 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 2047 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 2048 } 2049 2050 return Owned(new (Context) ContinueStmt(ContinueLoc)); 2051} 2052 2053StmtResult 2054Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 2055 Scope *S = CurScope->getBreakParent(); 2056 if (!S) { 2057 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 2058 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 2059 } 2060 2061 return Owned(new (Context) BreakStmt(BreakLoc)); 2062} 2063 2064/// \brief Determine whether the given expression is a candidate for 2065/// copy elision in either a return statement or a throw expression. 2066/// 2067/// \param ReturnType If we're determining the copy elision candidate for 2068/// a return statement, this is the return type of the function. If we're 2069/// determining the copy elision candidate for a throw expression, this will 2070/// be a NULL type. 2071/// 2072/// \param E The expression being returned from the function or block, or 2073/// being thrown. 2074/// 2075/// \param AllowFunctionParameter Whether we allow function parameters to 2076/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but 2077/// we re-use this logic to determine whether we should try to move as part of 2078/// a return or throw (which does allow function parameters). 2079/// 2080/// \returns The NRVO candidate variable, if the return statement may use the 2081/// NRVO, or NULL if there is no such candidate. 2082const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, 2083 Expr *E, 2084 bool AllowFunctionParameter) { 2085 QualType ExprType = E->getType(); 2086 // - in a return statement in a function with ... 2087 // ... a class return type ... 2088 if (!ReturnType.isNull()) { 2089 if (!ReturnType->isRecordType()) 2090 return 0; 2091 // ... the same cv-unqualified type as the function return type ... 2092 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) 2093 return 0; 2094 } 2095 2096 // ... the expression is the name of a non-volatile automatic object 2097 // (other than a function or catch-clause parameter)) ... 2098 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); 2099 if (!DR || DR->refersToEnclosingLocal()) 2100 return 0; 2101 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 2102 if (!VD) 2103 return 0; 2104 2105 // ...object (other than a function or catch-clause parameter)... 2106 if (VD->getKind() != Decl::Var && 2107 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) 2108 return 0; 2109 if (VD->isExceptionVariable()) return 0; 2110 2111 // ...automatic... 2112 if (!VD->hasLocalStorage()) return 0; 2113 2114 // ...non-volatile... 2115 if (VD->getType().isVolatileQualified()) return 0; 2116 if (VD->getType()->isReferenceType()) return 0; 2117 2118 // __block variables can't be allocated in a way that permits NRVO. 2119 if (VD->hasAttr<BlocksAttr>()) return 0; 2120 2121 // Variables with higher required alignment than their type's ABI 2122 // alignment cannot use NRVO. 2123 if (VD->hasAttr<AlignedAttr>() && 2124 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) 2125 return 0; 2126 2127 return VD; 2128} 2129 2130/// \brief Perform the initialization of a potentially-movable value, which 2131/// is the result of return value. 2132/// 2133/// This routine implements C++0x [class.copy]p33, which attempts to treat 2134/// returned lvalues as rvalues in certain cases (to prefer move construction), 2135/// then falls back to treating them as lvalues if that failed. 2136ExprResult 2137Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, 2138 const VarDecl *NRVOCandidate, 2139 QualType ResultType, 2140 Expr *Value, 2141 bool AllowNRVO) { 2142 // C++0x [class.copy]p33: 2143 // When the criteria for elision of a copy operation are met or would 2144 // be met save for the fact that the source object is a function 2145 // parameter, and the object to be copied is designated by an lvalue, 2146 // overload resolution to select the constructor for the copy is first 2147 // performed as if the object were designated by an rvalue. 2148 ExprResult Res = ExprError(); 2149 if (AllowNRVO && 2150 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { 2151 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, 2152 Value->getType(), CK_NoOp, Value, VK_XValue); 2153 2154 Expr *InitExpr = &AsRvalue; 2155 InitializationKind Kind 2156 = InitializationKind::CreateCopy(Value->getLocStart(), 2157 Value->getLocStart()); 2158 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1); 2159 2160 // [...] If overload resolution fails, or if the type of the first 2161 // parameter of the selected constructor is not an rvalue reference 2162 // to the object's type (possibly cv-qualified), overload resolution 2163 // is performed again, considering the object as an lvalue. 2164 if (Seq) { 2165 for (InitializationSequence::step_iterator Step = Seq.step_begin(), 2166 StepEnd = Seq.step_end(); 2167 Step != StepEnd; ++Step) { 2168 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) 2169 continue; 2170 2171 CXXConstructorDecl *Constructor 2172 = cast<CXXConstructorDecl>(Step->Function.Function); 2173 2174 const RValueReferenceType *RRefType 2175 = Constructor->getParamDecl(0)->getType() 2176 ->getAs<RValueReferenceType>(); 2177 2178 // If we don't meet the criteria, break out now. 2179 if (!RRefType || 2180 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), 2181 Context.getTypeDeclType(Constructor->getParent()))) 2182 break; 2183 2184 // Promote "AsRvalue" to the heap, since we now need this 2185 // expression node to persist. 2186 Value = ImplicitCastExpr::Create(Context, Value->getType(), 2187 CK_NoOp, Value, 0, VK_XValue); 2188 2189 // Complete type-checking the initialization of the return type 2190 // using the constructor we found. 2191 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1)); 2192 } 2193 } 2194 } 2195 2196 // Either we didn't meet the criteria for treating an lvalue as an rvalue, 2197 // above, or overload resolution failed. Either way, we need to try 2198 // (again) now with the return value expression as written. 2199 if (Res.isInvalid()) 2200 Res = PerformCopyInitialization(Entity, SourceLocation(), Value); 2201 2202 return Res; 2203} 2204 2205/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements 2206/// for capturing scopes. 2207/// 2208StmtResult 2209Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2210 // If this is the first return we've seen, infer the return type. 2211 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those 2212 // rules which allows multiple return statements. 2213 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); 2214 QualType FnRetType = CurCap->ReturnType; 2215 2216 // For blocks/lambdas with implicit return types, we check each return 2217 // statement individually, and deduce the common return type when the block 2218 // or lambda is completed. 2219 if (CurCap->HasImplicitReturnType) { 2220 if (RetValExp && !isa<InitListExpr>(RetValExp)) { 2221 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); 2222 if (Result.isInvalid()) 2223 return StmtError(); 2224 RetValExp = Result.take(); 2225 2226 if (!RetValExp->isTypeDependent()) 2227 FnRetType = RetValExp->getType(); 2228 else 2229 FnRetType = CurCap->ReturnType = Context.DependentTy; 2230 } else { 2231 if (RetValExp) { 2232 // C++11 [expr.lambda.prim]p4 bans inferring the result from an 2233 // initializer list, because it is not an expression (even 2234 // though we represent it as one). We still deduce 'void'. 2235 Diag(ReturnLoc, diag::err_lambda_return_init_list) 2236 << RetValExp->getSourceRange(); 2237 } 2238 2239 FnRetType = Context.VoidTy; 2240 } 2241 2242 // Although we'll properly infer the type of the block once it's completed, 2243 // make sure we provide a return type now for better error recovery. 2244 if (CurCap->ReturnType.isNull()) 2245 CurCap->ReturnType = FnRetType; 2246 } 2247 assert(!FnRetType.isNull()); 2248 2249 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { 2250 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { 2251 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); 2252 return StmtError(); 2253 } 2254 } else { 2255 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap); 2256 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){ 2257 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); 2258 return StmtError(); 2259 } 2260 } 2261 2262 // Otherwise, verify that this result type matches the previous one. We are 2263 // pickier with blocks than for normal functions because we don't have GCC 2264 // compatibility to worry about here. 2265 const VarDecl *NRVOCandidate = 0; 2266 if (FnRetType->isDependentType()) { 2267 // Delay processing for now. TODO: there are lots of dependent 2268 // types we can conclusively prove aren't void. 2269 } else if (FnRetType->isVoidType()) { 2270 if (RetValExp && !isa<InitListExpr>(RetValExp) && 2271 !(getLangOpts().CPlusPlus && 2272 (RetValExp->isTypeDependent() || 2273 RetValExp->getType()->isVoidType()))) { 2274 if (!getLangOpts().CPlusPlus && 2275 RetValExp->getType()->isVoidType()) 2276 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; 2277 else { 2278 Diag(ReturnLoc, diag::err_return_block_has_expr); 2279 RetValExp = 0; 2280 } 2281 } 2282 } else if (!RetValExp) { 2283 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 2284 } else if (!RetValExp->isTypeDependent()) { 2285 // we have a non-void block with an expression, continue checking 2286 2287 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2288 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2289 // function return. 2290 2291 // In C++ the return statement is handled via a copy initialization. 2292 // the C version of which boils down to CheckSingleAssignmentConstraints. 2293 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2294 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2295 FnRetType, 2296 NRVOCandidate != 0); 2297 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2298 FnRetType, RetValExp); 2299 if (Res.isInvalid()) { 2300 // FIXME: Cleanup temporaries here, anyway? 2301 return StmtError(); 2302 } 2303 RetValExp = Res.take(); 2304 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2305 } 2306 2307 if (RetValExp) { 2308 CheckImplicitConversions(RetValExp, ReturnLoc); 2309 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2310 } 2311 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 2312 NRVOCandidate); 2313 2314 // If we need to check for the named return value optimization, 2315 // or if we need to infer the return type, 2316 // save the return statement in our scope for later processing. 2317 if (CurCap->HasImplicitReturnType || 2318 (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2319 !CurContext->isDependentContext())) 2320 FunctionScopes.back()->Returns.push_back(Result); 2321 2322 return Owned(Result); 2323} 2324 2325StmtResult 2326Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 2327 // Check for unexpanded parameter packs. 2328 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) 2329 return StmtError(); 2330 2331 if (isa<CapturingScopeInfo>(getCurFunction())) 2332 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); 2333 2334 QualType FnRetType; 2335 QualType RelatedRetType; 2336 if (const FunctionDecl *FD = getCurFunctionDecl()) { 2337 FnRetType = FD->getResultType(); 2338 if (FD->hasAttr<NoReturnAttr>() || 2339 FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) 2340 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 2341 << FD->getDeclName(); 2342 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { 2343 FnRetType = MD->getResultType(); 2344 if (MD->hasRelatedResultType() && MD->getClassInterface()) { 2345 // In the implementation of a method with a related return type, the 2346 // type used to type-check the validity of return statements within the 2347 // method body is a pointer to the type of the class being implemented. 2348 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); 2349 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); 2350 } 2351 } else // If we don't have a function/method context, bail. 2352 return StmtError(); 2353 2354 ReturnStmt *Result = 0; 2355 if (FnRetType->isVoidType()) { 2356 if (RetValExp) { 2357 if (isa<InitListExpr>(RetValExp)) { 2358 // We simply never allow init lists as the return value of void 2359 // functions. This is compatible because this was never allowed before, 2360 // so there's no legacy code to deal with. 2361 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2362 int FunctionKind = 0; 2363 if (isa<ObjCMethodDecl>(CurDecl)) 2364 FunctionKind = 1; 2365 else if (isa<CXXConstructorDecl>(CurDecl)) 2366 FunctionKind = 2; 2367 else if (isa<CXXDestructorDecl>(CurDecl)) 2368 FunctionKind = 3; 2369 2370 Diag(ReturnLoc, diag::err_return_init_list) 2371 << CurDecl->getDeclName() << FunctionKind 2372 << RetValExp->getSourceRange(); 2373 2374 // Drop the expression. 2375 RetValExp = 0; 2376 } else if (!RetValExp->isTypeDependent()) { 2377 // C99 6.8.6.4p1 (ext_ since GCC warns) 2378 unsigned D = diag::ext_return_has_expr; 2379 if (RetValExp->getType()->isVoidType()) 2380 D = diag::ext_return_has_void_expr; 2381 else { 2382 ExprResult Result = Owned(RetValExp); 2383 Result = IgnoredValueConversions(Result.take()); 2384 if (Result.isInvalid()) 2385 return StmtError(); 2386 RetValExp = Result.take(); 2387 RetValExp = ImpCastExprToType(RetValExp, 2388 Context.VoidTy, CK_ToVoid).take(); 2389 } 2390 2391 // return (some void expression); is legal in C++. 2392 if (D != diag::ext_return_has_void_expr || 2393 !getLangOpts().CPlusPlus) { 2394 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 2395 2396 int FunctionKind = 0; 2397 if (isa<ObjCMethodDecl>(CurDecl)) 2398 FunctionKind = 1; 2399 else if (isa<CXXConstructorDecl>(CurDecl)) 2400 FunctionKind = 2; 2401 else if (isa<CXXDestructorDecl>(CurDecl)) 2402 FunctionKind = 3; 2403 2404 Diag(ReturnLoc, D) 2405 << CurDecl->getDeclName() << FunctionKind 2406 << RetValExp->getSourceRange(); 2407 } 2408 } 2409 2410 if (RetValExp) { 2411 CheckImplicitConversions(RetValExp, ReturnLoc); 2412 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2413 } 2414 } 2415 2416 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); 2417 } else if (!RetValExp && !FnRetType->isDependentType()) { 2418 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 2419 // C99 6.8.6.4p1 (ext_ since GCC warns) 2420 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; 2421 2422 if (FunctionDecl *FD = getCurFunctionDecl()) 2423 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 2424 else 2425 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 2426 Result = new (Context) ReturnStmt(ReturnLoc); 2427 } else { 2428 const VarDecl *NRVOCandidate = 0; 2429 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 2430 // we have a non-void function with an expression, continue checking 2431 2432 if (!RelatedRetType.isNull()) { 2433 // If we have a related result type, perform an extra conversion here. 2434 // FIXME: The diagnostics here don't really describe what is happening. 2435 InitializedEntity Entity = 2436 InitializedEntity::InitializeTemporary(RelatedRetType); 2437 2438 ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), 2439 RetValExp); 2440 if (Res.isInvalid()) { 2441 // FIXME: Cleanup temporaries here, anyway? 2442 return StmtError(); 2443 } 2444 RetValExp = Res.takeAs<Expr>(); 2445 } 2446 2447 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 2448 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 2449 // function return. 2450 2451 // In C++ the return statement is handled via a copy initialization, 2452 // the C version of which boils down to CheckSingleAssignmentConstraints. 2453 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); 2454 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, 2455 FnRetType, 2456 NRVOCandidate != 0); 2457 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, 2458 FnRetType, RetValExp); 2459 if (Res.isInvalid()) { 2460 // FIXME: Cleanup temporaries here, anyway? 2461 return StmtError(); 2462 } 2463 2464 RetValExp = Res.takeAs<Expr>(); 2465 if (RetValExp) 2466 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 2467 } 2468 2469 if (RetValExp) { 2470 CheckImplicitConversions(RetValExp, ReturnLoc); 2471 RetValExp = MaybeCreateExprWithCleanups(RetValExp); 2472 } 2473 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); 2474 } 2475 2476 // If we need to check for the named return value optimization, save the 2477 // return statement in our scope for later processing. 2478 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && 2479 !CurContext->isDependentContext()) 2480 FunctionScopes.back()->Returns.push_back(Result); 2481 2482 return Owned(Result); 2483} 2484 2485/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 2486/// ignore "noop" casts in places where an lvalue is required by an inline asm. 2487/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 2488/// provide a strong guidance to not use it. 2489/// 2490/// This method checks to see if the argument is an acceptable l-value and 2491/// returns false if it is a case we can handle. 2492static bool CheckAsmLValue(const Expr *E, Sema &S) { 2493 // Type dependent expressions will be checked during instantiation. 2494 if (E->isTypeDependent()) 2495 return false; 2496 2497 if (E->isLValue()) 2498 return false; // Cool, this is an lvalue. 2499 2500 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 2501 // are supposed to allow. 2502 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 2503 if (E != E2 && E2->isLValue()) { 2504 if (!S.getLangOpts().HeinousExtensions) 2505 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 2506 << E->getSourceRange(); 2507 else 2508 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 2509 << E->getSourceRange(); 2510 // Accept, even if we emitted an error diagnostic. 2511 return false; 2512 } 2513 2514 // None of the above, just randomly invalid non-lvalue. 2515 return true; 2516} 2517 2518/// isOperandMentioned - Return true if the specified operand # is mentioned 2519/// anywhere in the decomposed asm string. 2520static bool isOperandMentioned(unsigned OpNo, 2521 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) { 2522 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { 2523 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; 2524 if (!Piece.isOperand()) continue; 2525 2526 // If this is a reference to the input and if the input was the smaller 2527 // one, then we have to reject this asm. 2528 if (Piece.getOperandNo() == OpNo) 2529 return true; 2530 } 2531 return false; 2532} 2533 2534StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple, 2535 bool IsVolatile, unsigned NumOutputs, 2536 unsigned NumInputs, IdentifierInfo **Names, 2537 MultiExprArg constraints, MultiExprArg exprs, 2538 Expr *asmString, MultiExprArg clobbers, 2539 SourceLocation RParenLoc, bool MSAsm) { 2540 unsigned NumClobbers = clobbers.size(); 2541 StringLiteral **Constraints = 2542 reinterpret_cast<StringLiteral**>(constraints.get()); 2543 Expr **Exprs = exprs.get(); 2544 StringLiteral *AsmString = cast<StringLiteral>(asmString); 2545 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 2546 2547 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 2548 2549 // The parser verifies that there is a string literal here. 2550 if (!AsmString->isAscii()) 2551 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 2552 << AsmString->getSourceRange()); 2553 2554 for (unsigned i = 0; i != NumOutputs; i++) { 2555 StringLiteral *Literal = Constraints[i]; 2556 if (!Literal->isAscii()) 2557 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2558 << Literal->getSourceRange()); 2559 2560 StringRef OutputName; 2561 if (Names[i]) 2562 OutputName = Names[i]->getName(); 2563 2564 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); 2565 if (!Context.getTargetInfo().validateOutputConstraint(Info)) 2566 return StmtError(Diag(Literal->getLocStart(), 2567 diag::err_asm_invalid_output_constraint) 2568 << Info.getConstraintStr()); 2569 2570 // Check that the output exprs are valid lvalues. 2571 Expr *OutputExpr = Exprs[i]; 2572 if (CheckAsmLValue(OutputExpr, *this)) { 2573 return StmtError(Diag(OutputExpr->getLocStart(), 2574 diag::err_asm_invalid_lvalue_in_output) 2575 << OutputExpr->getSourceRange()); 2576 } 2577 2578 OutputConstraintInfos.push_back(Info); 2579 } 2580 2581 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 2582 2583 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 2584 StringLiteral *Literal = Constraints[i]; 2585 if (!Literal->isAscii()) 2586 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2587 << Literal->getSourceRange()); 2588 2589 StringRef InputName; 2590 if (Names[i]) 2591 InputName = Names[i]->getName(); 2592 2593 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); 2594 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), 2595 NumOutputs, Info)) { 2596 return StmtError(Diag(Literal->getLocStart(), 2597 diag::err_asm_invalid_input_constraint) 2598 << Info.getConstraintStr()); 2599 } 2600 2601 Expr *InputExpr = Exprs[i]; 2602 2603 // Only allow void types for memory constraints. 2604 if (Info.allowsMemory() && !Info.allowsRegister()) { 2605 if (CheckAsmLValue(InputExpr, *this)) 2606 return StmtError(Diag(InputExpr->getLocStart(), 2607 diag::err_asm_invalid_lvalue_in_input) 2608 << Info.getConstraintStr() 2609 << InputExpr->getSourceRange()); 2610 } 2611 2612 if (Info.allowsRegister()) { 2613 if (InputExpr->getType()->isVoidType()) { 2614 return StmtError(Diag(InputExpr->getLocStart(), 2615 diag::err_asm_invalid_type_in_input) 2616 << InputExpr->getType() << Info.getConstraintStr() 2617 << InputExpr->getSourceRange()); 2618 } 2619 } 2620 2621 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); 2622 if (Result.isInvalid()) 2623 return StmtError(); 2624 2625 Exprs[i] = Result.take(); 2626 InputConstraintInfos.push_back(Info); 2627 } 2628 2629 // Check that the clobbers are valid. 2630 for (unsigned i = 0; i != NumClobbers; i++) { 2631 StringLiteral *Literal = Clobbers[i]; 2632 if (!Literal->isAscii()) 2633 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 2634 << Literal->getSourceRange()); 2635 2636 StringRef Clobber = Literal->getString(); 2637 2638 if (!Context.getTargetInfo().isValidClobber(Clobber)) 2639 return StmtError(Diag(Literal->getLocStart(), 2640 diag::err_asm_unknown_register_name) << Clobber); 2641 } 2642 2643 AsmStmt *NS = 2644 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm, 2645 NumOutputs, NumInputs, Names, Constraints, Exprs, 2646 AsmString, NumClobbers, Clobbers, RParenLoc); 2647 // Validate the asm string, ensuring it makes sense given the operands we 2648 // have. 2649 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 2650 unsigned DiagOffs; 2651 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 2652 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 2653 << AsmString->getSourceRange(); 2654 return StmtError(); 2655 } 2656 2657 // Validate tied input operands for type mismatches. 2658 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 2659 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 2660 2661 // If this is a tied constraint, verify that the output and input have 2662 // either exactly the same type, or that they are int/ptr operands with the 2663 // same size (int/long, int*/long, are ok etc). 2664 if (!Info.hasTiedOperand()) continue; 2665 2666 unsigned TiedTo = Info.getTiedOperand(); 2667 unsigned InputOpNo = i+NumOutputs; 2668 Expr *OutputExpr = Exprs[TiedTo]; 2669 Expr *InputExpr = Exprs[InputOpNo]; 2670 2671 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) 2672 continue; 2673 2674 QualType InTy = InputExpr->getType(); 2675 QualType OutTy = OutputExpr->getType(); 2676 if (Context.hasSameType(InTy, OutTy)) 2677 continue; // All types can be tied to themselves. 2678 2679 // Decide if the input and output are in the same domain (integer/ptr or 2680 // floating point. 2681 enum AsmDomain { 2682 AD_Int, AD_FP, AD_Other 2683 } InputDomain, OutputDomain; 2684 2685 if (InTy->isIntegerType() || InTy->isPointerType()) 2686 InputDomain = AD_Int; 2687 else if (InTy->isRealFloatingType()) 2688 InputDomain = AD_FP; 2689 else 2690 InputDomain = AD_Other; 2691 2692 if (OutTy->isIntegerType() || OutTy->isPointerType()) 2693 OutputDomain = AD_Int; 2694 else if (OutTy->isRealFloatingType()) 2695 OutputDomain = AD_FP; 2696 else 2697 OutputDomain = AD_Other; 2698 2699 // They are ok if they are the same size and in the same domain. This 2700 // allows tying things like: 2701 // void* to int* 2702 // void* to int if they are the same size. 2703 // double to long double if they are the same size. 2704 // 2705 uint64_t OutSize = Context.getTypeSize(OutTy); 2706 uint64_t InSize = Context.getTypeSize(InTy); 2707 if (OutSize == InSize && InputDomain == OutputDomain && 2708 InputDomain != AD_Other) 2709 continue; 2710 2711 // If the smaller input/output operand is not mentioned in the asm string, 2712 // then we can promote the smaller one to a larger input and the asm string 2713 // won't notice. 2714 bool SmallerValueMentioned = false; 2715 2716 // If this is a reference to the input and if the input was the smaller 2717 // one, then we have to reject this asm. 2718 if (isOperandMentioned(InputOpNo, Pieces)) { 2719 // This is a use in the asm string of the smaller operand. Since we 2720 // codegen this by promoting to a wider value, the asm will get printed 2721 // "wrong". 2722 SmallerValueMentioned |= InSize < OutSize; 2723 } 2724 if (isOperandMentioned(TiedTo, Pieces)) { 2725 // If this is a reference to the output, and if the output is the larger 2726 // value, then it's ok because we'll promote the input to the larger type. 2727 SmallerValueMentioned |= OutSize < InSize; 2728 } 2729 2730 // If the smaller value wasn't mentioned in the asm string, and if the 2731 // output was a register, just extend the shorter one to the size of the 2732 // larger one. 2733 if (!SmallerValueMentioned && InputDomain != AD_Other && 2734 OutputConstraintInfos[TiedTo].allowsRegister()) 2735 continue; 2736 2737 // Either both of the operands were mentioned or the smaller one was 2738 // mentioned. One more special case that we'll allow: if the tied input is 2739 // integer, unmentioned, and is a constant, then we'll allow truncating it 2740 // down to the size of the destination. 2741 if (InputDomain == AD_Int && OutputDomain == AD_Int && 2742 !isOperandMentioned(InputOpNo, Pieces) && 2743 InputExpr->isEvaluatable(Context)) { 2744 CastKind castKind = 2745 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); 2746 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); 2747 Exprs[InputOpNo] = InputExpr; 2748 NS->setInputExpr(i, InputExpr); 2749 continue; 2750 } 2751 2752 Diag(InputExpr->getLocStart(), 2753 diag::err_asm_tying_incompatible_types) 2754 << InTy << OutTy << OutputExpr->getSourceRange() 2755 << InputExpr->getSourceRange(); 2756 return StmtError(); 2757 } 2758 2759 return Owned(NS); 2760} 2761 2762// needSpaceAsmToken - This function handles whitespace around asm punctuation. 2763// Returns true if a space should be emitted. 2764static inline bool needSpaceAsmToken(Token currTok) { 2765 static Token prevTok; 2766 2767 // No need for space after prevToken. 2768 switch(prevTok.getKind()) { 2769 default: 2770 break; 2771 case tok::l_square: 2772 case tok::r_square: 2773 case tok::l_brace: 2774 case tok::r_brace: 2775 case tok::colon: 2776 prevTok = currTok; 2777 return false; 2778 } 2779 2780 // No need for a space before currToken. 2781 switch(currTok.getKind()) { 2782 default: 2783 break; 2784 case tok::l_square: 2785 case tok::r_square: 2786 case tok::l_brace: 2787 case tok::r_brace: 2788 case tok::comma: 2789 case tok::colon: 2790 prevTok = currTok; 2791 return false; 2792 } 2793 prevTok = currTok; 2794 return true; 2795} 2796 2797static std::string PatchMSAsmString(Sema &SemaRef, bool &IsSimple, 2798 SourceLocation AsmLoc, 2799 ArrayRef<Token> AsmToks, 2800 const TargetInfo &TI) { 2801 // Assume simple asm stmt until we parse a non-register identifer. 2802 IsSimple = true; 2803 2804 if (AsmToks.empty()) 2805 return ""; 2806 2807 std::string Res; 2808 IdentifierInfo *II = AsmToks[0].getIdentifierInfo(); 2809 Res = II->getName().str(); 2810 2811 // Check the operands. 2812 for (unsigned i = 1, e = AsmToks.size(); i != e; ++i) { 2813 if (needSpaceAsmToken(AsmToks[i])) 2814 Res += " "; 2815 2816 switch (AsmToks[i].getKind()) { 2817 default: 2818 //llvm_unreachable("Unknown token."); 2819 break; 2820 case tok::comma: Res += ","; break; 2821 case tok::colon: Res += ":"; break; 2822 case tok::l_square: Res += "["; break; 2823 case tok::r_square: Res += "]"; break; 2824 case tok::l_brace: Res += "{"; break; 2825 case tok::r_brace: Res += "}"; break; 2826 case tok::numeric_constant: { 2827 SmallString<32> TokenBuf; 2828 TokenBuf.resize(32); 2829 bool StringInvalid = false; 2830 const char *ThisTokBuf = &TokenBuf[0]; 2831 unsigned ThisTokLen = 2832 Lexer::getSpelling(AsmToks[i], ThisTokBuf, SemaRef.getSourceManager(), 2833 SemaRef.getLangOpts(), &StringInvalid); 2834 Res += StringRef(ThisTokBuf, ThisTokLen); 2835 break; 2836 } 2837 case tok::identifier: { 2838 II = AsmToks[i].getIdentifierInfo(); 2839 StringRef Name = II->getName(); 2840 2841 // Valid registers don't need modification. 2842 if (TI.isValidGCCRegisterName(Name)) { 2843 Res += Name; 2844 break; 2845 } 2846 2847 // TODO: Lookup the identifier. 2848 IsSimple = false; 2849 } 2850 } // AsmToks[i].getKind() 2851 } 2852 return Res; 2853} 2854 2855// Build the unmodified MSAsmString. 2856static std::string buildMSAsmString(Sema &SemaRef, 2857 ArrayRef<Token> AsmToks, 2858 ArrayRef<unsigned> LineEnds) { 2859 if (AsmToks.empty()) 2860 return ""; 2861 2862 SmallString<512> Asm; 2863 SmallString<512> TokenBuf; 2864 TokenBuf.resize(512); 2865 unsigned AsmLineNum = 0; 2866 for (unsigned i = 0, e = AsmToks.size(); i < e; ++i) { 2867 const char *ThisTokBuf = &TokenBuf[0]; 2868 bool StringInvalid = false; 2869 unsigned ThisTokLen = 2870 Lexer::getSpelling(AsmToks[i], ThisTokBuf, SemaRef.getSourceManager(), 2871 SemaRef.getLangOpts(), &StringInvalid); 2872 if (i && (!AsmLineNum || i != LineEnds[AsmLineNum-1]) && 2873 needSpaceAsmToken(AsmToks[i])) 2874 Asm += ' '; 2875 Asm += StringRef(ThisTokBuf, ThisTokLen); 2876 if (i + 1 == LineEnds[AsmLineNum] && i + 1 != AsmToks.size()) { 2877 Asm += '\n'; 2878 ++AsmLineNum; 2879 } 2880 } 2881 return Asm.c_str(); 2882} 2883 2884StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, 2885 ArrayRef<Token> AsmToks, 2886 ArrayRef<unsigned> LineEnds, 2887 SourceLocation EndLoc) { 2888 // MS-style inline assembly is not fully supported, so emit a warning. 2889 Diag(AsmLoc, diag::warn_unsupported_msasm); 2890 2891 // Empty asm statements don't need to instantiate the AsmParser, etc. 2892 if (AsmToks.empty()) { 2893 StringRef AsmString; 2894 MSAsmStmt *NS = 2895 new (Context) MSAsmStmt(Context, AsmLoc, /* IsSimple */ true, 2896 /* IsVolatile */ true, AsmToks, LineEnds, 2897 AsmString, EndLoc); 2898 return Owned(NS); 2899 } 2900 2901 std::string AsmString = buildMSAsmString(*this, AsmToks, LineEnds); 2902 2903 bool IsSimple; 2904 // Rewrite operands to appease the AsmParser. 2905 std::string PatchedAsmString = 2906 PatchMSAsmString(*this, IsSimple, AsmLoc, AsmToks, Context.getTargetInfo()); 2907 2908 // Initialize targets and assembly printers/parsers. 2909 llvm::InitializeAllTargetInfos(); 2910 llvm::InitializeAllTargetMCs(); 2911 llvm::InitializeAllAsmParsers(); 2912 2913 // Get the target specific parser. 2914 std::string Error; 2915 const std::string &TT = Context.getTargetInfo().getTriple().getTriple(); 2916 const llvm::Target *TheTarget(llvm::TargetRegistry::lookupTarget(TT, Error)); 2917 2918 llvm::SourceMgr SrcMgr; 2919 llvm::MemoryBuffer *Buffer = 2920 llvm::MemoryBuffer::getMemBuffer(PatchedAsmString, "<inline asm>"); 2921 2922 // Tell SrcMgr about this buffer, which is what the parser will pick up. 2923 SrcMgr.AddNewSourceBuffer(Buffer, llvm::SMLoc()); 2924 2925 OwningPtr<llvm::MCAsmInfo> MAI(TheTarget->createMCAsmInfo(TT)); 2926 OwningPtr<llvm::MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT)); 2927 OwningPtr<llvm::MCObjectFileInfo> MOFI(new llvm::MCObjectFileInfo()); 2928 llvm::MCContext Ctx(*MAI, *MRI, MOFI.get(), &SrcMgr); 2929 OwningPtr<llvm::MCSubtargetInfo> 2930 STI(TheTarget->createMCSubtargetInfo(TT, "", "")); 2931 2932 OwningPtr<llvm::MCStreamer> Str; 2933 OwningPtr<llvm::MCAsmParser> 2934 Parser(createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI)); 2935 OwningPtr<llvm::MCTargetAsmParser> 2936 TargetParser(TheTarget->createMCAsmParser(*STI, *Parser)); 2937 2938 // Change to the Intel dialect. 2939 Parser->setAssemblerDialect(1); 2940 Parser->setTargetParser(*TargetParser.get()); 2941 2942 MSAsmStmt *NS = 2943 new (Context) MSAsmStmt(Context, AsmLoc, IsSimple, /* IsVolatile */ true, 2944 AsmToks, LineEnds, AsmString, EndLoc); 2945 2946 return Owned(NS); 2947} 2948 2949StmtResult 2950Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 2951 SourceLocation RParen, Decl *Parm, 2952 Stmt *Body) { 2953 VarDecl *Var = cast_or_null<VarDecl>(Parm); 2954 if (Var && Var->isInvalidDecl()) 2955 return StmtError(); 2956 2957 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); 2958} 2959 2960StmtResult 2961Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { 2962 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); 2963} 2964 2965StmtResult 2966Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, 2967 MultiStmtArg CatchStmts, Stmt *Finally) { 2968 if (!getLangOpts().ObjCExceptions) 2969 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; 2970 2971 getCurFunction()->setHasBranchProtectedScope(); 2972 unsigned NumCatchStmts = CatchStmts.size(); 2973 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, 2974 CatchStmts.release(), 2975 NumCatchStmts, 2976 Finally)); 2977} 2978 2979StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) { 2980 if (Throw) { 2981 ExprResult Result = DefaultLvalueConversion(Throw); 2982 if (Result.isInvalid()) 2983 return StmtError(); 2984 2985 Throw = MaybeCreateExprWithCleanups(Result.take()); 2986 QualType ThrowType = Throw->getType(); 2987 // Make sure the expression type is an ObjC pointer or "void *". 2988 if (!ThrowType->isDependentType() && 2989 !ThrowType->isObjCObjectPointerType()) { 2990 const PointerType *PT = ThrowType->getAs<PointerType>(); 2991 if (!PT || !PT->getPointeeType()->isVoidType()) 2992 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 2993 << Throw->getType() << Throw->getSourceRange()); 2994 } 2995 } 2996 2997 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); 2998} 2999 3000StmtResult 3001Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, 3002 Scope *CurScope) { 3003 if (!getLangOpts().ObjCExceptions) 3004 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; 3005 3006 if (!Throw) { 3007 // @throw without an expression designates a rethrow (which much occur 3008 // in the context of an @catch clause). 3009 Scope *AtCatchParent = CurScope; 3010 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 3011 AtCatchParent = AtCatchParent->getParent(); 3012 if (!AtCatchParent) 3013 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 3014 } 3015 return BuildObjCAtThrowStmt(AtLoc, Throw); 3016} 3017 3018ExprResult 3019Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { 3020 ExprResult result = DefaultLvalueConversion(operand); 3021 if (result.isInvalid()) 3022 return ExprError(); 3023 operand = result.take(); 3024 3025 // Make sure the expression type is an ObjC pointer or "void *". 3026 QualType type = operand->getType(); 3027 if (!type->isDependentType() && 3028 !type->isObjCObjectPointerType()) { 3029 const PointerType *pointerType = type->getAs<PointerType>(); 3030 if (!pointerType || !pointerType->getPointeeType()->isVoidType()) 3031 return Diag(atLoc, diag::error_objc_synchronized_expects_object) 3032 << type << operand->getSourceRange(); 3033 } 3034 3035 // The operand to @synchronized is a full-expression. 3036 return MaybeCreateExprWithCleanups(operand); 3037} 3038 3039StmtResult 3040Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, 3041 Stmt *SyncBody) { 3042 // We can't jump into or indirect-jump out of a @synchronized block. 3043 getCurFunction()->setHasBranchProtectedScope(); 3044 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); 3045} 3046 3047/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 3048/// and creates a proper catch handler from them. 3049StmtResult 3050Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, 3051 Stmt *HandlerBlock) { 3052 // There's nothing to test that ActOnExceptionDecl didn't already test. 3053 return Owned(new (Context) CXXCatchStmt(CatchLoc, 3054 cast_or_null<VarDecl>(ExDecl), 3055 HandlerBlock)); 3056} 3057 3058StmtResult 3059Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { 3060 getCurFunction()->setHasBranchProtectedScope(); 3061 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); 3062} 3063 3064namespace { 3065 3066class TypeWithHandler { 3067 QualType t; 3068 CXXCatchStmt *stmt; 3069public: 3070 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 3071 : t(type), stmt(statement) {} 3072 3073 // An arbitrary order is fine as long as it places identical 3074 // types next to each other. 3075 bool operator<(const TypeWithHandler &y) const { 3076 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) 3077 return true; 3078 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) 3079 return false; 3080 else 3081 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 3082 } 3083 3084 bool operator==(const TypeWithHandler& other) const { 3085 return t == other.t; 3086 } 3087 3088 CXXCatchStmt *getCatchStmt() const { return stmt; } 3089 SourceLocation getTypeSpecStartLoc() const { 3090 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 3091 } 3092}; 3093 3094} 3095 3096/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 3097/// handlers and creates a try statement from them. 3098StmtResult 3099Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, 3100 MultiStmtArg RawHandlers) { 3101 // Don't report an error if 'try' is used in system headers. 3102 if (!getLangOpts().CXXExceptions && 3103 !getSourceManager().isInSystemHeader(TryLoc)) 3104 Diag(TryLoc, diag::err_exceptions_disabled) << "try"; 3105 3106 unsigned NumHandlers = RawHandlers.size(); 3107 assert(NumHandlers > 0 && 3108 "The parser shouldn't call this if there are no handlers."); 3109 Stmt **Handlers = RawHandlers.get(); 3110 3111 SmallVector<TypeWithHandler, 8> TypesWithHandlers; 3112 3113 for (unsigned i = 0; i < NumHandlers; ++i) { 3114 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); 3115 if (!Handler->getExceptionDecl()) { 3116 if (i < NumHandlers - 1) 3117 return StmtError(Diag(Handler->getLocStart(), 3118 diag::err_early_catch_all)); 3119 3120 continue; 3121 } 3122 3123 const QualType CaughtType = Handler->getCaughtType(); 3124 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 3125 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 3126 } 3127 3128 // Detect handlers for the same type as an earlier one. 3129 if (NumHandlers > 1) { 3130 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 3131 3132 TypeWithHandler prev = TypesWithHandlers[0]; 3133 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 3134 TypeWithHandler curr = TypesWithHandlers[i]; 3135 3136 if (curr == prev) { 3137 Diag(curr.getTypeSpecStartLoc(), 3138 diag::warn_exception_caught_by_earlier_handler) 3139 << curr.getCatchStmt()->getCaughtType().getAsString(); 3140 Diag(prev.getTypeSpecStartLoc(), 3141 diag::note_previous_exception_handler) 3142 << prev.getCatchStmt()->getCaughtType().getAsString(); 3143 } 3144 3145 prev = curr; 3146 } 3147 } 3148 3149 getCurFunction()->setHasBranchProtectedScope(); 3150 3151 // FIXME: We should detect handlers that cannot catch anything because an 3152 // earlier handler catches a superclass. Need to find a method that is not 3153 // quadratic for this. 3154 // Neither of these are explicitly forbidden, but every compiler detects them 3155 // and warns. 3156 3157 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, 3158 Handlers, NumHandlers)); 3159} 3160 3161StmtResult 3162Sema::ActOnSEHTryBlock(bool IsCXXTry, 3163 SourceLocation TryLoc, 3164 Stmt *TryBlock, 3165 Stmt *Handler) { 3166 assert(TryBlock && Handler); 3167 3168 getCurFunction()->setHasBranchProtectedScope(); 3169 3170 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); 3171} 3172 3173StmtResult 3174Sema::ActOnSEHExceptBlock(SourceLocation Loc, 3175 Expr *FilterExpr, 3176 Stmt *Block) { 3177 assert(FilterExpr && Block); 3178 3179 if(!FilterExpr->getType()->isIntegerType()) { 3180 return StmtError(Diag(FilterExpr->getExprLoc(), 3181 diag::err_filter_expression_integral) 3182 << FilterExpr->getType()); 3183 } 3184 3185 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); 3186} 3187 3188StmtResult 3189Sema::ActOnSEHFinallyBlock(SourceLocation Loc, 3190 Stmt *Block) { 3191 assert(Block); 3192 return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); 3193} 3194 3195StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, 3196 bool IsIfExists, 3197 NestedNameSpecifierLoc QualifierLoc, 3198 DeclarationNameInfo NameInfo, 3199 Stmt *Nested) 3200{ 3201 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, 3202 QualifierLoc, NameInfo, 3203 cast<CompoundStmt>(Nested)); 3204} 3205 3206 3207StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, 3208 bool IsIfExists, 3209 CXXScopeSpec &SS, 3210 UnqualifiedId &Name, 3211 Stmt *Nested) { 3212 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, 3213 SS.getWithLocInContext(Context), 3214 GetNameFromUnqualifiedId(Name), 3215 Nested); 3216} 3217