1 //===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements semantic analysis for statements.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/SemaInternal.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ASTDiagnostic.h"
17 #include "clang/AST/CharUnits.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/EvaluatedExprVisitor.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/ExprObjC.h"
22 #include "clang/AST/StmtCXX.h"
23 #include "clang/AST/StmtObjC.h"
24 #include "clang/AST/TypeLoc.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Lex/Preprocessor.h"
27 #include "clang/Sema/Initialization.h"
28 #include "clang/Sema/Lookup.h"
29 #include "clang/Sema/Scope.h"
30 #include "clang/Sema/ScopeInfo.h"
31 #include "llvm/ADT/ArrayRef.h"
32 #include "llvm/ADT/STLExtras.h"
33 #include "llvm/ADT/SmallPtrSet.h"
34 #include "llvm/ADT/SmallString.h"
35 #include "llvm/ADT/SmallVector.h"
36 using namespace clang;
39 StmtResult Sema::ActOnExprStmt(ExprResult FE) {
43 FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(),
44 /*DiscardedValue*/ true);
48 // C99 6.8.3p2: The expression in an expression statement is evaluated as a
49 // void expression for its side effects. Conversion to void allows any
50 // operand, even incomplete types.
52 // Same thing in for stmt first clause (when expr) and third clause.
53 return Owned(static_cast<Stmt*>(FE.take()));
57 StmtResult Sema::ActOnExprStmtError() {
58 DiscardCleanupsInEvaluationContext();
62 StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
63 bool HasLeadingEmptyMacro) {
64 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro));
67 StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,
68 SourceLocation EndLoc) {
69 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
71 // If we have an invalid decl, just return an error.
72 if (DG.isNull()) return StmtError();
74 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
77 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
78 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
80 // If we have an invalid decl, just return.
81 if (DG.isNull() || !DG.isSingleDecl()) return;
82 VarDecl *var = cast<VarDecl>(DG.getSingleDecl());
84 // suppress any potential 'unused variable' warning.
87 // foreach variables are never actually initialized in the way that
88 // the parser came up with.
91 // In ARC, we don't need to retain the iteration variable of a fast
92 // enumeration loop. Rather than actually trying to catch that
93 // during declaration processing, we remove the consequences here.
94 if (getLangOpts().ObjCAutoRefCount) {
95 QualType type = var->getType();
97 // Only do this if we inferred the lifetime. Inferred lifetime
98 // will show up as a local qualifier because explicit lifetime
99 // should have shown up as an AttributedType instead.
100 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) {
101 // Add 'const' and mark the variable as pseudo-strong.
102 var->setType(type.withConst());
103 var->setARCPseudoStrong(true);
108 /// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='.
110 /// Adding a cast to void (or other expression wrappers) will prevent the
111 /// warning from firing.
112 static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) {
114 bool IsNotEqual, CanAssign;
116 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
117 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE)
120 Loc = Op->getOperatorLoc();
121 IsNotEqual = Op->getOpcode() == BO_NE;
122 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue();
123 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) {
124 if (Op->getOperator() != OO_EqualEqual &&
125 Op->getOperator() != OO_ExclaimEqual)
128 Loc = Op->getOperatorLoc();
129 IsNotEqual = Op->getOperator() == OO_ExclaimEqual;
130 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue();
132 // Not a typo-prone comparison.
136 // Suppress warnings when the operator, suspicious as it may be, comes from
137 // a macro expansion.
138 if (S.SourceMgr.isMacroBodyExpansion(Loc))
141 S.Diag(Loc, diag::warn_unused_comparison)
142 << (unsigned)IsNotEqual << E->getSourceRange();
144 // If the LHS is a plausible entity to assign to, provide a fixit hint to
145 // correct common typos.
148 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign)
149 << FixItHint::CreateReplacement(Loc, "|=");
151 S.Diag(Loc, diag::note_equality_comparison_to_assign)
152 << FixItHint::CreateReplacement(Loc, "=");
158 void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
159 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
160 return DiagnoseUnusedExprResult(Label->getSubStmt());
162 const Expr *E = dyn_cast_or_null<Expr>(S);
165 SourceLocation ExprLoc = E->IgnoreParens()->getExprLoc();
166 // In most cases, we don't want to warn if the expression is written in a
167 // macro body, or if the macro comes from a system header. If the offending
168 // expression is a call to a function with the warn_unused_result attribute,
169 // we warn no matter the location. Because of the order in which the various
170 // checks need to happen, we factor out the macro-related test here.
171 bool ShouldSuppress =
172 SourceMgr.isMacroBodyExpansion(ExprLoc) ||
173 SourceMgr.isInSystemMacro(ExprLoc);
175 const Expr *WarnExpr;
178 if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context))
181 // If this is a GNU statement expression expanded from a macro, it is probably
182 // unused because it is a function-like macro that can be used as either an
183 // expression or statement. Don't warn, because it is almost certainly a
185 if (isa<StmtExpr>(E) && Loc.isMacroID())
188 // Okay, we have an unused result. Depending on what the base expression is,
189 // we might want to make a more specific diagnostic. Check for one of these
191 unsigned DiagID = diag::warn_unused_expr;
192 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E))
193 E = Temps->getSubExpr();
194 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E))
195 E = TempExpr->getSubExpr();
197 if (DiagnoseUnusedComparison(*this, E))
201 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
202 if (E->getType()->isVoidType())
205 // If the callee has attribute pure, const, or warn_unused_result, warn with
206 // a more specific message to make it clear what is happening. If the call
207 // is written in a macro body, only warn if it has the warn_unused_result
209 if (const Decl *FD = CE->getCalleeDecl()) {
210 if (FD->getAttr<WarnUnusedResultAttr>()) {
211 Diag(Loc, diag::warn_unused_result) << R1 << R2;
216 if (FD->getAttr<PureAttr>()) {
217 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
220 if (FD->getAttr<ConstAttr>()) {
221 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
225 } else if (ShouldSuppress)
228 if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
229 if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
230 Diag(Loc, diag::err_arc_unused_init_message) << R1;
233 const ObjCMethodDecl *MD = ME->getMethodDecl();
234 if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
235 Diag(Loc, diag::warn_unused_result) << R1 << R2;
238 } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
239 const Expr *Source = POE->getSyntacticForm();
240 if (isa<ObjCSubscriptRefExpr>(Source))
241 DiagID = diag::warn_unused_container_subscript_expr;
243 DiagID = diag::warn_unused_property_expr;
244 } else if (const CXXFunctionalCastExpr *FC
245 = dyn_cast<CXXFunctionalCastExpr>(E)) {
246 if (isa<CXXConstructExpr>(FC->getSubExpr()) ||
247 isa<CXXTemporaryObjectExpr>(FC->getSubExpr()))
250 // Diagnose "(void*) blah" as a typo for "(void) blah".
251 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {
252 TypeSourceInfo *TI = CE->getTypeInfoAsWritten();
253 QualType T = TI->getType();
255 // We really do want to use the non-canonical type here.
256 if (T == Context.VoidPtrTy) {
257 PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>();
259 Diag(Loc, diag::warn_unused_voidptr)
260 << FixItHint::CreateRemoval(TL.getStarLoc());
265 if (E->isGLValue() && E->getType().isVolatileQualified()) {
266 Diag(Loc, diag::warn_unused_volatile) << R1 << R2;
270 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2);
273 void Sema::ActOnStartOfCompoundStmt() {
277 void Sema::ActOnFinishOfCompoundStmt() {
281 sema::CompoundScopeInfo &Sema::getCurCompoundScope() const {
282 return getCurFunction()->CompoundScopes.back();
286 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
287 MultiStmtArg elts, bool isStmtExpr) {
288 unsigned NumElts = elts.size();
289 Stmt **Elts = elts.data();
290 // If we're in C89 mode, check that we don't have any decls after stmts. If
291 // so, emit an extension diagnostic.
292 if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) {
293 // Note that __extension__ can be around a decl.
295 // Skip over all declarations.
296 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
299 // We found the end of the list or a statement. Scan for another declstmt.
300 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
304 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
305 Diag(D->getLocation(), diag::ext_mixed_decls_code);
308 // Warn about unused expressions in statements.
309 for (unsigned i = 0; i != NumElts; ++i) {
310 // Ignore statements that are last in a statement expression.
311 if (isStmtExpr && i == NumElts - 1)
314 DiagnoseUnusedExprResult(Elts[i]);
317 // Check for suspicious empty body (null statement) in `for' and `while'
318 // statements. Don't do anything for template instantiations, this just adds
320 if (NumElts != 0 && !CurrentInstantiationScope &&
321 getCurCompoundScope().HasEmptyLoopBodies) {
322 for (unsigned i = 0; i != NumElts - 1; ++i)
323 DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]);
326 return Owned(new (Context) CompoundStmt(Context,
327 llvm::makeArrayRef(Elts, NumElts),
332 Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal,
333 SourceLocation DotDotDotLoc, Expr *RHSVal,
334 SourceLocation ColonLoc) {
335 assert((LHSVal != 0) && "missing expression in case statement");
337 if (getCurFunction()->SwitchStack.empty()) {
338 Diag(CaseLoc, diag::err_case_not_in_switch);
342 if (!getLangOpts().CPlusPlus11) {
343 // C99 6.8.4.2p3: The expression shall be an integer constant.
344 // However, GCC allows any evaluatable integer expression.
345 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) {
346 LHSVal = VerifyIntegerConstantExpression(LHSVal).take();
351 // GCC extension: The expression shall be an integer constant.
353 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) {
354 RHSVal = VerifyIntegerConstantExpression(RHSVal).take();
355 // Recover from an error by just forgetting about it.
359 LHSVal = ActOnFinishFullExpr(LHSVal, LHSVal->getExprLoc(), false,
360 getLangOpts().CPlusPlus11).take();
362 RHSVal = ActOnFinishFullExpr(RHSVal, RHSVal->getExprLoc(), false,
363 getLangOpts().CPlusPlus11).take();
365 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
367 getCurFunction()->SwitchStack.back()->addSwitchCase(CS);
371 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
372 void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) {
373 DiagnoseUnusedExprResult(SubStmt);
375 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt);
376 CS->setSubStmt(SubStmt);
380 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
381 Stmt *SubStmt, Scope *CurScope) {
382 DiagnoseUnusedExprResult(SubStmt);
384 if (getCurFunction()->SwitchStack.empty()) {
385 Diag(DefaultLoc, diag::err_default_not_in_switch);
386 return Owned(SubStmt);
389 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
390 getCurFunction()->SwitchStack.back()->addSwitchCase(DS);
395 Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
396 SourceLocation ColonLoc, Stmt *SubStmt) {
397 // If the label was multiply defined, reject it now.
398 if (TheDecl->getStmt()) {
399 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName();
400 Diag(TheDecl->getLocation(), diag::note_previous_definition);
401 return Owned(SubStmt);
404 // Otherwise, things are good. Fill in the declaration and return it.
405 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
406 TheDecl->setStmt(LS);
407 if (!TheDecl->isGnuLocal()) {
408 TheDecl->setLocStart(IdentLoc);
409 TheDecl->setLocation(IdentLoc);
414 StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc,
415 ArrayRef<const Attr*> Attrs,
417 // Fill in the declaration and return it.
418 AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt);
423 Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar,
424 Stmt *thenStmt, SourceLocation ElseLoc,
426 // If the condition was invalid, discard the if statement. We could recover
427 // better by replacing it with a valid expr, but don't do that yet.
428 if (!CondVal.get() && !CondVar) {
429 getCurFunction()->setHasDroppedStmt();
433 ExprResult CondResult(CondVal.release());
435 VarDecl *ConditionVar = 0;
437 ConditionVar = cast<VarDecl>(CondVar);
438 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true);
439 if (CondResult.isInvalid())
442 Expr *ConditionExpr = CondResult.takeAs<Expr>();
446 DiagnoseUnusedExprResult(thenStmt);
449 DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt,
450 diag::warn_empty_if_body);
453 DiagnoseUnusedExprResult(elseStmt);
455 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr,
456 thenStmt, ElseLoc, elseStmt));
459 /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
460 /// the specified width and sign. If an overflow occurs, detect it and emit
461 /// the specified diagnostic.
462 void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val,
463 unsigned NewWidth, bool NewSign,
466 // Perform a conversion to the promoted condition type if needed.
467 if (NewWidth > Val.getBitWidth()) {
468 // If this is an extension, just do it.
469 Val = Val.extend(NewWidth);
470 Val.setIsSigned(NewSign);
472 // If the input was signed and negative and the output is
473 // unsigned, don't bother to warn: this is implementation-defined
475 // FIXME: Introduce a second, default-ignored warning for this case?
476 } else if (NewWidth < Val.getBitWidth()) {
477 // If this is a truncation, check for overflow.
478 llvm::APSInt ConvVal(Val);
479 ConvVal = ConvVal.trunc(NewWidth);
480 ConvVal.setIsSigned(NewSign);
481 ConvVal = ConvVal.extend(Val.getBitWidth());
482 ConvVal.setIsSigned(Val.isSigned());
484 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10);
486 // Regardless of whether a diagnostic was emitted, really do the
488 Val = Val.trunc(NewWidth);
489 Val.setIsSigned(NewSign);
490 } else if (NewSign != Val.isSigned()) {
491 // Convert the sign to match the sign of the condition. This can cause
492 // overflow as well: unsigned(INTMIN)
493 // We don't diagnose this overflow, because it is implementation-defined
495 // FIXME: Introduce a second, default-ignored warning for this case?
496 llvm::APSInt OldVal(Val);
497 Val.setIsSigned(NewSign);
502 struct CaseCompareFunctor {
503 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
504 const llvm::APSInt &RHS) {
505 return LHS.first < RHS;
507 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
508 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
509 return LHS.first < RHS.first;
511 bool operator()(const llvm::APSInt &LHS,
512 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
513 return LHS < RHS.first;
518 /// CmpCaseVals - Comparison predicate for sorting case values.
520 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
521 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
522 if (lhs.first < rhs.first)
525 if (lhs.first == rhs.first &&
526 lhs.second->getCaseLoc().getRawEncoding()
527 < rhs.second->getCaseLoc().getRawEncoding())
532 /// CmpEnumVals - Comparison predicate for sorting enumeration values.
534 static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
535 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
537 return lhs.first < rhs.first;
540 /// EqEnumVals - Comparison preficate for uniqing enumeration values.
542 static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
543 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
545 return lhs.first == rhs.first;
548 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
549 /// potentially integral-promoted expression @p expr.
550 static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) {
551 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr))
552 expr = cleanups->getSubExpr();
553 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) {
554 if (impcast->getCastKind() != CK_IntegralCast) break;
555 expr = impcast->getSubExpr();
557 return expr->getType();
561 Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond,
563 ExprResult CondResult;
565 VarDecl *ConditionVar = 0;
567 ConditionVar = cast<VarDecl>(CondVar);
568 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false);
569 if (CondResult.isInvalid())
572 Cond = CondResult.release();
578 class SwitchConvertDiagnoser : public ICEConvertDiagnoser {
582 SwitchConvertDiagnoser(Expr *Cond)
583 : ICEConvertDiagnoser(false, true), Cond(Cond) { }
585 virtual DiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
587 return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T;
590 virtual DiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
592 return S.Diag(Loc, diag::err_switch_incomplete_class_type)
593 << T << Cond->getSourceRange();
596 virtual DiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
599 return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy;
602 virtual DiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
604 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
605 << ConvTy->isEnumeralType() << ConvTy;
608 virtual DiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
610 return S.Diag(Loc, diag::err_switch_multiple_conversions) << T;
613 virtual DiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
615 return S.Diag(Conv->getLocation(), diag::note_switch_conversion)
616 << ConvTy->isEnumeralType() << ConvTy;
619 virtual DiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
622 return DiagnosticBuilder::getEmpty();
624 } SwitchDiagnoser(Cond);
627 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond, SwitchDiagnoser,
628 /*AllowScopedEnumerations*/ true);
629 if (CondResult.isInvalid()) return StmtError();
630 Cond = CondResult.take();
632 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
633 CondResult = UsualUnaryConversions(Cond);
634 if (CondResult.isInvalid()) return StmtError();
635 Cond = CondResult.take();
638 CondResult = ActOnFinishFullExpr(Cond, SwitchLoc);
639 if (CondResult.isInvalid())
641 Cond = CondResult.take();
644 getCurFunction()->setHasBranchIntoScope();
646 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond);
647 getCurFunction()->SwitchStack.push_back(SS);
651 static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) {
652 if (Val.getBitWidth() < BitWidth)
653 Val = Val.extend(BitWidth);
654 else if (Val.getBitWidth() > BitWidth)
655 Val = Val.trunc(BitWidth);
656 Val.setIsSigned(IsSigned);
660 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
662 SwitchStmt *SS = cast<SwitchStmt>(Switch);
663 assert(SS == getCurFunction()->SwitchStack.back() &&
664 "switch stack missing push/pop!");
666 SS->setBody(BodyStmt, SwitchLoc);
667 getCurFunction()->SwitchStack.pop_back();
669 Expr *CondExpr = SS->getCond();
670 if (!CondExpr) return StmtError();
672 QualType CondType = CondExpr->getType();
674 Expr *CondExprBeforePromotion = CondExpr;
675 QualType CondTypeBeforePromotion =
676 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion);
679 // Integral promotions are performed (on the switch condition).
681 // A case value unrepresentable by the original switch condition
682 // type (before the promotion) doesn't make sense, even when it can
683 // be represented by the promoted type. Therefore we need to find
684 // the pre-promotion type of the switch condition.
685 if (!CondExpr->isTypeDependent()) {
686 // We have already converted the expression to an integral or enumeration
687 // type, when we started the switch statement. If we don't have an
688 // appropriate type now, just return an error.
689 if (!CondType->isIntegralOrEnumerationType())
692 if (CondExpr->isKnownToHaveBooleanValue()) {
693 // switch(bool_expr) {...} is often a programmer error, e.g.
694 // switch(n && mask) { ... } // Doh - should be "n & mask".
695 // One can always use an if statement instead of switch(bool_expr).
696 Diag(SwitchLoc, diag::warn_bool_switch_condition)
697 << CondExpr->getSourceRange();
701 // Get the bitwidth of the switched-on value before promotions. We must
702 // convert the integer case values to this width before comparison.
703 bool HasDependentValue
704 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
706 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion);
708 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType();
710 // Accumulate all of the case values in a vector so that we can sort them
711 // and detect duplicates. This vector contains the APInt for the case after
712 // it has been converted to the condition type.
713 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
716 // Keep track of any GNU case ranges we see. The APSInt is the low value.
717 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
718 CaseRangesTy CaseRanges;
720 DefaultStmt *TheDefaultStmt = 0;
722 bool CaseListIsErroneous = false;
724 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
725 SC = SC->getNextSwitchCase()) {
727 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
728 if (TheDefaultStmt) {
729 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
730 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
732 // FIXME: Remove the default statement from the switch block so that
733 // we'll return a valid AST. This requires recursing down the AST and
734 // finding it, not something we are set up to do right now. For now,
735 // just lop the entire switch stmt out of the AST.
736 CaseListIsErroneous = true;
741 CaseStmt *CS = cast<CaseStmt>(SC);
743 Expr *Lo = CS->getLHS();
745 if (Lo->isTypeDependent() || Lo->isValueDependent()) {
746 HasDependentValue = true;
752 if (getLangOpts().CPlusPlus11) {
753 // C++11 [stmt.switch]p2: the constant-expression shall be a converted
754 // constant expression of the promoted type of the switch condition.
756 CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue);
757 if (ConvLo.isInvalid()) {
758 CaseListIsErroneous = true;
763 // We already verified that the expression has a i-c-e value (C99
764 // 6.8.4.2p3) - get that value now.
765 LoVal = Lo->EvaluateKnownConstInt(Context);
767 // If the LHS is not the same type as the condition, insert an implicit
769 Lo = DefaultLvalueConversion(Lo).take();
770 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take();
773 // Convert the value to the same width/sign as the condition had prior to
774 // integral promotions.
776 // FIXME: This causes us to reject valid code:
777 // switch ((char)c) { case 256: case 0: return 0; }
778 // Here we claim there is a duplicated condition value, but there is not.
779 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned,
781 diag::warn_case_value_overflow);
785 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
787 if (CS->getRHS()->isTypeDependent() ||
788 CS->getRHS()->isValueDependent()) {
789 HasDependentValue = true;
792 CaseRanges.push_back(std::make_pair(LoVal, CS));
794 CaseVals.push_back(std::make_pair(LoVal, CS));
798 if (!HasDependentValue) {
799 // If we don't have a default statement, check whether the
800 // condition is constant.
801 llvm::APSInt ConstantCondValue;
802 bool HasConstantCond = false;
803 if (!HasDependentValue && !TheDefaultStmt) {
805 = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context,
806 Expr::SE_AllowSideEffects);
807 assert(!HasConstantCond ||
808 (ConstantCondValue.getBitWidth() == CondWidth &&
809 ConstantCondValue.isSigned() == CondIsSigned));
811 bool ShouldCheckConstantCond = HasConstantCond;
813 // Sort all the scalar case values so we can easily detect duplicates.
814 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
816 if (!CaseVals.empty()) {
817 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) {
818 if (ShouldCheckConstantCond &&
819 CaseVals[i].first == ConstantCondValue)
820 ShouldCheckConstantCond = false;
822 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) {
823 // If we have a duplicate, report it.
824 // First, determine if either case value has a name
825 StringRef PrevString, CurrString;
826 Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts();
827 Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts();
828 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) {
829 PrevString = DeclRef->getDecl()->getName();
831 if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) {
832 CurrString = DeclRef->getDecl()->getName();
834 SmallString<16> CaseValStr;
835 CaseVals[i-1].first.toString(CaseValStr);
837 if (PrevString == CurrString)
838 Diag(CaseVals[i].second->getLHS()->getLocStart(),
839 diag::err_duplicate_case) <<
840 (PrevString.empty() ? CaseValStr.str() : PrevString);
842 Diag(CaseVals[i].second->getLHS()->getLocStart(),
843 diag::err_duplicate_case_differing_expr) <<
844 (PrevString.empty() ? CaseValStr.str() : PrevString) <<
845 (CurrString.empty() ? CaseValStr.str() : CurrString) <<
848 Diag(CaseVals[i-1].second->getLHS()->getLocStart(),
849 diag::note_duplicate_case_prev);
850 // FIXME: We really want to remove the bogus case stmt from the
851 // substmt, but we have no way to do this right now.
852 CaseListIsErroneous = true;
857 // Detect duplicate case ranges, which usually don't exist at all in
859 if (!CaseRanges.empty()) {
860 // Sort all the case ranges by their low value so we can easily detect
861 // overlaps between ranges.
862 std::stable_sort(CaseRanges.begin(), CaseRanges.end());
864 // Scan the ranges, computing the high values and removing empty ranges.
865 std::vector<llvm::APSInt> HiVals;
866 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
867 llvm::APSInt &LoVal = CaseRanges[i].first;
868 CaseStmt *CR = CaseRanges[i].second;
869 Expr *Hi = CR->getRHS();
872 if (getLangOpts().CPlusPlus11) {
873 // C++11 [stmt.switch]p2: the constant-expression shall be a converted
874 // constant expression of the promoted type of the switch condition.
876 CheckConvertedConstantExpression(Hi, CondType, HiVal,
878 if (ConvHi.isInvalid()) {
879 CaseListIsErroneous = true;
884 HiVal = Hi->EvaluateKnownConstInt(Context);
886 // If the RHS is not the same type as the condition, insert an
888 Hi = DefaultLvalueConversion(Hi).take();
889 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take();
892 // Convert the value to the same width/sign as the condition.
893 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned,
895 diag::warn_case_value_overflow);
899 // If the low value is bigger than the high value, the case is empty.
901 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range)
902 << SourceRange(CR->getLHS()->getLocStart(),
904 CaseRanges.erase(CaseRanges.begin()+i);
909 if (ShouldCheckConstantCond &&
910 LoVal <= ConstantCondValue &&
911 ConstantCondValue <= HiVal)
912 ShouldCheckConstantCond = false;
914 HiVals.push_back(HiVal);
917 // Rescan the ranges, looking for overlap with singleton values and other
918 // ranges. Since the range list is sorted, we only need to compare case
919 // ranges with their neighbors.
920 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
921 llvm::APSInt &CRLo = CaseRanges[i].first;
922 llvm::APSInt &CRHi = HiVals[i];
923 CaseStmt *CR = CaseRanges[i].second;
925 // Check to see whether the case range overlaps with any
927 CaseStmt *OverlapStmt = 0;
928 llvm::APSInt OverlapVal(32);
930 // Find the smallest value >= the lower bound. If I is in the
931 // case range, then we have overlap.
932 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
933 CaseVals.end(), CRLo,
934 CaseCompareFunctor());
935 if (I != CaseVals.end() && I->first < CRHi) {
936 OverlapVal = I->first; // Found overlap with scalar.
937 OverlapStmt = I->second;
940 // Find the smallest value bigger than the upper bound.
941 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
942 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
943 OverlapVal = (I-1)->first; // Found overlap with scalar.
944 OverlapStmt = (I-1)->second;
947 // Check to see if this case stmt overlaps with the subsequent
949 if (i && CRLo <= HiVals[i-1]) {
950 OverlapVal = HiVals[i-1]; // Found overlap with range.
951 OverlapStmt = CaseRanges[i-1].second;
955 // If we have a duplicate, report it.
956 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case)
957 << OverlapVal.toString(10);
958 Diag(OverlapStmt->getLHS()->getLocStart(),
959 diag::note_duplicate_case_prev);
960 // FIXME: We really want to remove the bogus case stmt from the
961 // substmt, but we have no way to do this right now.
962 CaseListIsErroneous = true;
967 // Complain if we have a constant condition and we didn't find a match.
968 if (!CaseListIsErroneous && ShouldCheckConstantCond) {
969 // TODO: it would be nice if we printed enums as enums, chars as
971 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition)
972 << ConstantCondValue.toString(10)
973 << CondExpr->getSourceRange();
976 // Check to see if switch is over an Enum and handles all of its
977 // values. We only issue a warning if there is not 'default:', but
978 // we still do the analysis to preserve this information in the AST
979 // (which can be used by flow-based analyes).
981 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
983 // If switch has default case, then ignore it.
984 if (!CaseListIsErroneous && !HasConstantCond && ET) {
985 const EnumDecl *ED = ET->getDecl();
986 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64>
990 // Gather all enum values, set their type and sort them,
991 // allowing easier comparison with CaseVals.
992 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin();
993 EDI != ED->enumerator_end(); ++EDI) {
994 llvm::APSInt Val = EDI->getInitVal();
995 AdjustAPSInt(Val, CondWidth, CondIsSigned);
996 EnumVals.push_back(std::make_pair(Val, *EDI));
998 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
999 EnumValsTy::iterator EIend =
1000 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1002 // See which case values aren't in enum.
1003 EnumValsTy::const_iterator EI = EnumVals.begin();
1004 for (CaseValsTy::const_iterator CI = CaseVals.begin();
1005 CI != CaseVals.end(); CI++) {
1006 while (EI != EIend && EI->first < CI->first)
1008 if (EI == EIend || EI->first > CI->first)
1009 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
1010 << CondTypeBeforePromotion;
1012 // See which of case ranges aren't in enum
1013 EI = EnumVals.begin();
1014 for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
1015 RI != CaseRanges.end() && EI != EIend; RI++) {
1016 while (EI != EIend && EI->first < RI->first)
1019 if (EI == EIend || EI->first != RI->first) {
1020 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
1021 << CondTypeBeforePromotion;
1025 RI->second->getRHS()->EvaluateKnownConstInt(Context);
1026 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1027 while (EI != EIend && EI->first < Hi)
1029 if (EI == EIend || EI->first != Hi)
1030 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum)
1031 << CondTypeBeforePromotion;
1034 // Check which enum vals aren't in switch
1035 CaseValsTy::const_iterator CI = CaseVals.begin();
1036 CaseRangesTy::const_iterator RI = CaseRanges.begin();
1037 bool hasCasesNotInSwitch = false;
1039 SmallVector<DeclarationName,8> UnhandledNames;
1041 for (EI = EnumVals.begin(); EI != EIend; EI++){
1042 // Drop unneeded case values
1044 while (CI != CaseVals.end() && CI->first < EI->first)
1047 if (CI != CaseVals.end() && CI->first == EI->first)
1050 // Drop unneeded case ranges
1051 for (; RI != CaseRanges.end(); RI++) {
1053 RI->second->getRHS()->EvaluateKnownConstInt(Context);
1054 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
1055 if (EI->first <= Hi)
1059 if (RI == CaseRanges.end() || EI->first < RI->first) {
1060 hasCasesNotInSwitch = true;
1061 UnhandledNames.push_back(EI->second->getDeclName());
1065 if (TheDefaultStmt && UnhandledNames.empty())
1066 Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default);
1068 // Produce a nice diagnostic if multiple values aren't handled.
1069 switch (UnhandledNames.size()) {
1072 Diag(CondExpr->getExprLoc(), TheDefaultStmt
1073 ? diag::warn_def_missing_case1 : diag::warn_missing_case1)
1074 << UnhandledNames[0];
1077 Diag(CondExpr->getExprLoc(), TheDefaultStmt
1078 ? diag::warn_def_missing_case2 : diag::warn_missing_case2)
1079 << UnhandledNames[0] << UnhandledNames[1];
1082 Diag(CondExpr->getExprLoc(), TheDefaultStmt
1083 ? diag::warn_def_missing_case3 : diag::warn_missing_case3)
1084 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2];
1087 Diag(CondExpr->getExprLoc(), TheDefaultStmt
1088 ? diag::warn_def_missing_cases : diag::warn_missing_cases)
1089 << (unsigned)UnhandledNames.size()
1090 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2];
1094 if (!hasCasesNotInSwitch)
1095 SS->setAllEnumCasesCovered();
1099 DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt,
1100 diag::warn_empty_switch_body);
1102 // FIXME: If the case list was broken is some way, we don't have a good system
1103 // to patch it up. Instead, just return the whole substmt as broken.
1104 if (CaseListIsErroneous)
1111 Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
1113 unsigned DIAG = diag::warn_not_in_enum_assignement;
1114 if (Diags.getDiagnosticLevel(DIAG, SrcExpr->getExprLoc())
1115 == DiagnosticsEngine::Ignored)
1118 if (const EnumType *ET = DstType->getAs<EnumType>())
1119 if (!Context.hasSameType(SrcType, DstType) &&
1120 SrcType->isIntegerType()) {
1121 if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() &&
1122 SrcExpr->isIntegerConstantExpr(Context)) {
1123 // Get the bitwidth of the enum value before promotions.
1124 unsigned DstWith = Context.getIntWidth(DstType);
1125 bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType();
1127 llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context);
1128 const EnumDecl *ED = ET->getDecl();
1129 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64>
1131 EnumValsTy EnumVals;
1133 // Gather all enum values, set their type and sort them,
1134 // allowing easier comparison with rhs constant.
1135 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin();
1136 EDI != ED->enumerator_end(); ++EDI) {
1137 llvm::APSInt Val = EDI->getInitVal();
1138 AdjustAPSInt(Val, DstWith, DstIsSigned);
1139 EnumVals.push_back(std::make_pair(Val, *EDI));
1141 if (EnumVals.empty())
1143 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
1144 EnumValsTy::iterator EIend =
1145 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
1147 // See which case values aren't in enum.
1148 EnumValsTy::const_iterator EI = EnumVals.begin();
1149 while (EI != EIend && EI->first < RhsVal)
1151 if (EI == EIend || EI->first != RhsVal) {
1152 Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignement)
1160 Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond,
1161 Decl *CondVar, Stmt *Body) {
1162 ExprResult CondResult(Cond.release());
1164 VarDecl *ConditionVar = 0;
1166 ConditionVar = cast<VarDecl>(CondVar);
1167 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true);
1168 if (CondResult.isInvalid())
1171 Expr *ConditionExpr = CondResult.take();
1175 DiagnoseUnusedExprResult(Body);
1177 if (isa<NullStmt>(Body))
1178 getCurCompoundScope().setHasEmptyLoopBodies();
1180 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr,
1185 Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
1186 SourceLocation WhileLoc, SourceLocation CondLParen,
1187 Expr *Cond, SourceLocation CondRParen) {
1188 assert(Cond && "ActOnDoStmt(): missing expression");
1190 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc);
1191 if (CondResult.isInvalid())
1193 Cond = CondResult.take();
1195 CondResult = ActOnFinishFullExpr(Cond, DoLoc);
1196 if (CondResult.isInvalid())
1198 Cond = CondResult.take();
1200 DiagnoseUnusedExprResult(Body);
1202 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen));
1206 // This visitor will traverse a conditional statement and store all
1207 // the evaluated decls into a vector. Simple is set to true if none
1208 // of the excluded constructs are used.
1209 class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> {
1210 llvm::SmallPtrSet<VarDecl*, 8> &Decls;
1211 SmallVector<SourceRange, 10> &Ranges;
1214 typedef EvaluatedExprVisitor<DeclExtractor> Inherited;
1216 DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls,
1217 SmallVector<SourceRange, 10> &Ranges) :
1218 Inherited(S.Context),
1223 bool isSimple() { return Simple; }
1225 // Replaces the method in EvaluatedExprVisitor.
1226 void VisitMemberExpr(MemberExpr* E) {
1230 // Any Stmt not whitelisted will cause the condition to be marked complex.
1231 void VisitStmt(Stmt *S) {
1235 void VisitBinaryOperator(BinaryOperator *E) {
1240 void VisitCastExpr(CastExpr *E) {
1241 Visit(E->getSubExpr());
1244 void VisitUnaryOperator(UnaryOperator *E) {
1245 // Skip checking conditionals with derefernces.
1246 if (E->getOpcode() == UO_Deref)
1249 Visit(E->getSubExpr());
1252 void VisitConditionalOperator(ConditionalOperator *E) {
1253 Visit(E->getCond());
1254 Visit(E->getTrueExpr());
1255 Visit(E->getFalseExpr());
1258 void VisitParenExpr(ParenExpr *E) {
1259 Visit(E->getSubExpr());
1262 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
1263 Visit(E->getOpaqueValue()->getSourceExpr());
1264 Visit(E->getFalseExpr());
1267 void VisitIntegerLiteral(IntegerLiteral *E) { }
1268 void VisitFloatingLiteral(FloatingLiteral *E) { }
1269 void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { }
1270 void VisitCharacterLiteral(CharacterLiteral *E) { }
1271 void VisitGNUNullExpr(GNUNullExpr *E) { }
1272 void VisitImaginaryLiteral(ImaginaryLiteral *E) { }
1274 void VisitDeclRefExpr(DeclRefExpr *E) {
1275 VarDecl *VD = dyn_cast<VarDecl>(E->getDecl());
1278 Ranges.push_back(E->getSourceRange());
1283 }; // end class DeclExtractor
1285 // DeclMatcher checks to see if the decls are used in a non-evauluated
1287 class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> {
1288 llvm::SmallPtrSet<VarDecl*, 8> &Decls;
1292 typedef EvaluatedExprVisitor<DeclMatcher> Inherited;
1294 DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, Stmt *Statement) :
1295 Inherited(S.Context), Decls(Decls), FoundDecl(false) {
1296 if (!Statement) return;
1301 void VisitReturnStmt(ReturnStmt *S) {
1305 void VisitBreakStmt(BreakStmt *S) {
1309 void VisitGotoStmt(GotoStmt *S) {
1313 void VisitCastExpr(CastExpr *E) {
1314 if (E->getCastKind() == CK_LValueToRValue)
1315 CheckLValueToRValueCast(E->getSubExpr());
1317 Visit(E->getSubExpr());
1320 void CheckLValueToRValueCast(Expr *E) {
1321 E = E->IgnoreParenImpCasts();
1323 if (isa<DeclRefExpr>(E)) {
1327 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
1328 Visit(CO->getCond());
1329 CheckLValueToRValueCast(CO->getTrueExpr());
1330 CheckLValueToRValueCast(CO->getFalseExpr());
1334 if (BinaryConditionalOperator *BCO =
1335 dyn_cast<BinaryConditionalOperator>(E)) {
1336 CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr());
1337 CheckLValueToRValueCast(BCO->getFalseExpr());
1344 void VisitDeclRefExpr(DeclRefExpr *E) {
1345 if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()))
1346 if (Decls.count(VD))
1350 bool FoundDeclInUse() { return FoundDecl; }
1352 }; // end class DeclMatcher
1354 void CheckForLoopConditionalStatement(Sema &S, Expr *Second,
1355 Expr *Third, Stmt *Body) {
1356 // Condition is empty
1357 if (!Second) return;
1359 if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body,
1360 Second->getLocStart())
1361 == DiagnosticsEngine::Ignored)
1364 PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body);
1365 llvm::SmallPtrSet<VarDecl*, 8> Decls;
1366 SmallVector<SourceRange, 10> Ranges;
1367 DeclExtractor DE(S, Decls, Ranges);
1370 // Don't analyze complex conditionals.
1371 if (!DE.isSimple()) return;
1374 if (Decls.size() == 0) return;
1376 // Don't warn on volatile, static, or global variables.
1377 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(),
1380 if ((*I)->getType().isVolatileQualified() ||
1381 (*I)->hasGlobalStorage()) return;
1383 if (DeclMatcher(S, Decls, Second).FoundDeclInUse() ||
1384 DeclMatcher(S, Decls, Third).FoundDeclInUse() ||
1385 DeclMatcher(S, Decls, Body).FoundDeclInUse())
1388 // Load decl names into diagnostic.
1389 if (Decls.size() > 4)
1392 PDiag << Decls.size();
1393 for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(),
1396 PDiag << (*I)->getDeclName();
1399 // Load SourceRanges into diagnostic if there is room.
1400 // Otherwise, load the SourceRange of the conditional expression.
1401 if (Ranges.size() <= PartialDiagnostic::MaxArguments)
1402 for (SmallVector<SourceRange, 10>::iterator I = Ranges.begin(),
1407 PDiag << Second->getSourceRange();
1409 S.Diag(Ranges.begin()->getBegin(), PDiag);
1415 Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
1416 Stmt *First, FullExprArg second, Decl *secondVar,
1418 SourceLocation RParenLoc, Stmt *Body) {
1419 if (!getLangOpts().CPlusPlus) {
1420 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
1421 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1422 // declare identifiers for objects having storage class 'auto' or
1424 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end();
1426 VarDecl *VD = dyn_cast<VarDecl>(*DI);
1427 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
1430 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
1431 // FIXME: mark decl erroneous!
1436 CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body);
1438 ExprResult SecondResult(second.release());
1439 VarDecl *ConditionVar = 0;
1441 ConditionVar = cast<VarDecl>(secondVar);
1442 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true);
1443 if (SecondResult.isInvalid())
1447 Expr *Third = third.release().takeAs<Expr>();
1449 DiagnoseUnusedExprResult(First);
1450 DiagnoseUnusedExprResult(Third);
1451 DiagnoseUnusedExprResult(Body);
1453 if (isa<NullStmt>(Body))
1454 getCurCompoundScope().setHasEmptyLoopBodies();
1456 return Owned(new (Context) ForStmt(Context, First,
1457 SecondResult.take(), ConditionVar,
1458 Third, Body, ForLoc, LParenLoc,
1462 /// In an Objective C collection iteration statement:
1464 /// x can be an arbitrary l-value expression. Bind it up as a
1465 /// full-expression.
1466 StmtResult Sema::ActOnForEachLValueExpr(Expr *E) {
1467 // Reduce placeholder expressions here. Note that this rejects the
1468 // use of pseudo-object l-values in this position.
1469 ExprResult result = CheckPlaceholderExpr(E);
1470 if (result.isInvalid()) return StmtError();
1473 ExprResult FullExpr = ActOnFinishFullExpr(E);
1474 if (FullExpr.isInvalid())
1476 return StmtResult(static_cast<Stmt*>(FullExpr.take()));
1480 Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) {
1484 // Bail out early if we've got a type-dependent expression.
1485 if (collection->isTypeDependent()) return Owned(collection);
1487 // Perform normal l-value conversion.
1488 ExprResult result = DefaultFunctionArrayLvalueConversion(collection);
1489 if (result.isInvalid())
1491 collection = result.take();
1493 // The operand needs to have object-pointer type.
1494 // TODO: should we do a contextual conversion?
1495 const ObjCObjectPointerType *pointerType =
1496 collection->getType()->getAs<ObjCObjectPointerType>();
1498 return Diag(forLoc, diag::err_collection_expr_type)
1499 << collection->getType() << collection->getSourceRange();
1501 // Check that the operand provides
1502 // - countByEnumeratingWithState:objects:count:
1503 const ObjCObjectType *objectType = pointerType->getObjectType();
1504 ObjCInterfaceDecl *iface = objectType->getInterface();
1506 // If we have a forward-declared type, we can't do this check.
1507 // Under ARC, it is an error not to have a forward-declared class.
1509 RequireCompleteType(forLoc, QualType(objectType, 0),
1510 getLangOpts().ObjCAutoRefCount
1511 ? diag::err_arc_collection_forward
1514 // Otherwise, if we have any useful type information, check that
1515 // the type declares the appropriate method.
1516 } else if (iface || !objectType->qual_empty()) {
1517 IdentifierInfo *selectorIdents[] = {
1518 &Context.Idents.get("countByEnumeratingWithState"),
1519 &Context.Idents.get("objects"),
1520 &Context.Idents.get("count")
1522 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]);
1524 ObjCMethodDecl *method = 0;
1526 // If there's an interface, look in both the public and private APIs.
1528 method = iface->lookupInstanceMethod(selector);
1529 if (!method) method = iface->lookupPrivateMethod(selector);
1532 // Also check protocol qualifiers.
1534 method = LookupMethodInQualifiedType(selector, pointerType,
1537 // If we didn't find it anywhere, give up.
1539 Diag(forLoc, diag::warn_collection_expr_type)
1540 << collection->getType() << selector << collection->getSourceRange();
1543 // TODO: check for an incompatible signature?
1546 // Wrap up any cleanups in the expression.
1547 return Owned(collection);
1551 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
1552 Stmt *First, Expr *collection,
1553 SourceLocation RParenLoc) {
1555 ExprResult CollectionExprResult =
1556 CheckObjCForCollectionOperand(ForLoc, collection);
1560 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
1561 if (!DS->isSingleDecl())
1562 return StmtError(Diag((*DS->decl_begin())->getLocation(),
1563 diag::err_toomany_element_decls));
1565 VarDecl *D = cast<VarDecl>(DS->getSingleDecl());
1566 FirstType = D->getType();
1567 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1568 // declare identifiers for objects having storage class 'auto' or
1570 if (!D->hasLocalStorage())
1571 return StmtError(Diag(D->getLocation(),
1572 diag::err_non_variable_decl_in_for));
1574 Expr *FirstE = cast<Expr>(First);
1575 if (!FirstE->isTypeDependent() && !FirstE->isLValue())
1576 return StmtError(Diag(First->getLocStart(),
1577 diag::err_selector_element_not_lvalue)
1578 << First->getSourceRange());
1580 FirstType = static_cast<Expr*>(First)->getType();
1582 if (!FirstType->isDependentType() &&
1583 !FirstType->isObjCObjectPointerType() &&
1584 !FirstType->isBlockPointerType())
1585 return StmtError(Diag(ForLoc, diag::err_selector_element_type)
1586 << FirstType << First->getSourceRange());
1589 if (CollectionExprResult.isInvalid())
1592 CollectionExprResult = ActOnFinishFullExpr(CollectionExprResult.take());
1593 if (CollectionExprResult.isInvalid())
1596 return Owned(new (Context) ObjCForCollectionStmt(First,
1597 CollectionExprResult.take(), 0,
1598 ForLoc, RParenLoc));
1601 /// Finish building a variable declaration for a for-range statement.
1602 /// \return true if an error occurs.
1603 static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init,
1604 SourceLocation Loc, int diag) {
1605 // Deduce the type for the iterator variable now rather than leaving it to
1606 // AddInitializerToDecl, so we can produce a more suitable diagnostic.
1607 TypeSourceInfo *InitTSI = 0;
1608 if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) ||
1609 SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI) ==
1611 SemaRef.Diag(Loc, diag) << Init->getType();
1613 Decl->setInvalidDecl();
1616 Decl->setTypeSourceInfo(InitTSI);
1617 Decl->setType(InitTSI->getType());
1619 // In ARC, infer lifetime.
1620 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if
1621 // we're doing the equivalent of fast iteration.
1622 if (SemaRef.getLangOpts().ObjCAutoRefCount &&
1623 SemaRef.inferObjCARCLifetime(Decl))
1624 Decl->setInvalidDecl();
1626 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false,
1627 /*TypeMayContainAuto=*/false);
1628 SemaRef.FinalizeDeclaration(Decl);
1629 SemaRef.CurContext->addHiddenDecl(Decl);
1635 /// Produce a note indicating which begin/end function was implicitly called
1636 /// by a C++11 for-range statement. This is often not obvious from the code,
1637 /// nor from the diagnostics produced when analysing the implicit expressions
1638 /// required in a for-range statement.
1639 void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E,
1640 Sema::BeginEndFunction BEF) {
1641 CallExpr *CE = dyn_cast<CallExpr>(E);
1644 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
1647 SourceLocation Loc = D->getLocation();
1649 std::string Description;
1650 bool IsTemplate = false;
1651 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) {
1652 Description = SemaRef.getTemplateArgumentBindingsText(
1653 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs());
1657 SemaRef.Diag(Loc, diag::note_for_range_begin_end)
1658 << BEF << IsTemplate << Description << E->getType();
1661 /// Build a variable declaration for a for-range statement.
1662 VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc,
1663 QualType Type, const char *Name) {
1664 DeclContext *DC = SemaRef.CurContext;
1665 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
1666 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
1667 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type,
1669 Decl->setImplicit();
1675 static bool ObjCEnumerationCollection(Expr *Collection) {
1676 return !Collection->isTypeDependent()
1677 && Collection->getType()->getAs<ObjCObjectPointerType>() != 0;
1680 /// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement.
1682 /// C++11 [stmt.ranged]:
1683 /// A range-based for statement is equivalent to
1686 /// auto && __range = range-init;
1687 /// for ( auto __begin = begin-expr,
1688 /// __end = end-expr;
1689 /// __begin != __end;
1691 /// for-range-declaration = *__begin;
1696 /// The body of the loop is not available yet, since it cannot be analysed until
1697 /// we have determined the type of the for-range-declaration.
1699 Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc,
1700 Stmt *First, SourceLocation ColonLoc, Expr *Range,
1701 SourceLocation RParenLoc, BuildForRangeKind Kind) {
1702 if (!First || !Range)
1705 if (ObjCEnumerationCollection(Range))
1706 return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc);
1708 DeclStmt *DS = dyn_cast<DeclStmt>(First);
1709 assert(DS && "first part of for range not a decl stmt");
1711 if (!DS->isSingleDecl()) {
1712 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range);
1715 if (DS->getSingleDecl()->isInvalidDecl())
1718 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression))
1721 // Build auto && __range = range-init
1722 SourceLocation RangeLoc = Range->getLocStart();
1723 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc,
1724 Context.getAutoRRefDeductType(),
1726 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc,
1727 diag::err_for_range_deduction_failure))
1730 // Claim the type doesn't contain auto: we've already done the checking.
1731 DeclGroupPtrTy RangeGroup =
1732 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false);
1733 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc);
1734 if (RangeDecl.isInvalid())
1737 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(),
1738 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS,
1742 /// \brief Create the initialization, compare, and increment steps for
1743 /// the range-based for loop expression.
1744 /// This function does not handle array-based for loops,
1745 /// which are created in Sema::BuildCXXForRangeStmt.
1747 /// \returns a ForRangeStatus indicating success or what kind of error occurred.
1748 /// BeginExpr and EndExpr are set and FRS_Success is returned on success;
1749 /// CandidateSet and BEF are set and some non-success value is returned on
1751 static Sema::ForRangeStatus BuildNonArrayForRange(Sema &SemaRef, Scope *S,
1752 Expr *BeginRange, Expr *EndRange,
1756 SourceLocation ColonLoc,
1757 OverloadCandidateSet *CandidateSet,
1758 ExprResult *BeginExpr,
1759 ExprResult *EndExpr,
1760 Sema::BeginEndFunction *BEF) {
1761 DeclarationNameInfo BeginNameInfo(
1762 &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc);
1763 DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"),
1766 LookupResult BeginMemberLookup(SemaRef, BeginNameInfo,
1767 Sema::LookupMemberName);
1768 LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName);
1770 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) {
1771 // - if _RangeT is a class type, the unqualified-ids begin and end are
1772 // looked up in the scope of class _RangeT as if by class member access
1773 // lookup (3.4.5), and if either (or both) finds at least one
1774 // declaration, begin-expr and end-expr are __range.begin() and
1775 // __range.end(), respectively;
1776 SemaRef.LookupQualifiedName(BeginMemberLookup, D);
1777 SemaRef.LookupQualifiedName(EndMemberLookup, D);
1779 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) {
1780 SourceLocation RangeLoc = BeginVar->getLocation();
1781 *BEF = BeginMemberLookup.empty() ? Sema::BEF_end : Sema::BEF_begin;
1783 SemaRef.Diag(RangeLoc, diag::err_for_range_member_begin_end_mismatch)
1784 << RangeLoc << BeginRange->getType() << *BEF;
1785 return Sema::FRS_DiagnosticIssued;
1788 // - otherwise, begin-expr and end-expr are begin(__range) and
1789 // end(__range), respectively, where begin and end are looked up with
1790 // argument-dependent lookup (3.4.2). For the purposes of this name
1791 // lookup, namespace std is an associated namespace.
1795 *BEF = Sema::BEF_begin;
1796 Sema::ForRangeStatus RangeStatus =
1797 SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, BeginVar,
1798 Sema::BEF_begin, BeginNameInfo,
1799 BeginMemberLookup, CandidateSet,
1800 BeginRange, BeginExpr);
1802 if (RangeStatus != Sema::FRS_Success)
1804 if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc,
1805 diag::err_for_range_iter_deduction_failure)) {
1806 NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF);
1807 return Sema::FRS_DiagnosticIssued;
1810 *BEF = Sema::BEF_end;
1812 SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, EndVar,
1813 Sema::BEF_end, EndNameInfo,
1814 EndMemberLookup, CandidateSet,
1816 if (RangeStatus != Sema::FRS_Success)
1818 if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc,
1819 diag::err_for_range_iter_deduction_failure)) {
1820 NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF);
1821 return Sema::FRS_DiagnosticIssued;
1823 return Sema::FRS_Success;
1826 /// Speculatively attempt to dereference an invalid range expression.
1827 /// If the attempt fails, this function will return a valid, null StmtResult
1828 /// and emit no diagnostics.
1829 static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S,
1830 SourceLocation ForLoc,
1832 SourceLocation ColonLoc,
1834 SourceLocation RangeLoc,
1835 SourceLocation RParenLoc) {
1836 // Determine whether we can rebuild the for-range statement with a
1837 // dereferenced range expression.
1838 ExprResult AdjustedRange;
1840 Sema::SFINAETrap Trap(SemaRef);
1842 AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range);
1843 if (AdjustedRange.isInvalid())
1844 return StmtResult();
1847 SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc,
1848 AdjustedRange.get(), RParenLoc,
1851 return StmtResult();
1854 // The attempt to dereference worked well enough that it could produce a valid
1855 // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in
1856 // case there are any other (non-fatal) problems with it.
1857 SemaRef.Diag(RangeLoc, diag::err_for_range_dereference)
1858 << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*");
1859 return SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc,
1860 AdjustedRange.get(), RParenLoc,
1861 Sema::BFRK_Rebuild);
1864 /// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement.
1866 Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc,
1867 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond,
1868 Expr *Inc, Stmt *LoopVarDecl,
1869 SourceLocation RParenLoc, BuildForRangeKind Kind) {
1870 Scope *S = getCurScope();
1872 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl);
1873 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl());
1874 QualType RangeVarType = RangeVar->getType();
1876 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl);
1877 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl());
1879 StmtResult BeginEndDecl = BeginEnd;
1880 ExprResult NotEqExpr = Cond, IncrExpr = Inc;
1882 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) {
1883 SourceLocation RangeLoc = RangeVar->getLocation();
1885 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
1887 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
1888 VK_LValue, ColonLoc);
1889 if (BeginRangeRef.isInvalid())
1892 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
1893 VK_LValue, ColonLoc);
1894 if (EndRangeRef.isInvalid())
1897 QualType AutoType = Context.getAutoDeductType();
1898 Expr *Range = RangeVar->getInit();
1901 QualType RangeType = Range->getType();
1903 if (RequireCompleteType(RangeLoc, RangeType,
1904 diag::err_for_range_incomplete_type))
1907 // Build auto __begin = begin-expr, __end = end-expr.
1908 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
1910 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
1913 // Build begin-expr and end-expr and attach to __begin and __end variables.
1914 ExprResult BeginExpr, EndExpr;
1915 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) {
1916 // - if _RangeT is an array type, begin-expr and end-expr are __range and
1917 // __range + __bound, respectively, where __bound is the array bound. If
1918 // _RangeT is an array of unknown size or an array of incomplete type,
1919 // the program is ill-formed;
1921 // begin-expr is __range.
1922 BeginExpr = BeginRangeRef;
1923 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc,
1924 diag::err_for_range_iter_deduction_failure)) {
1925 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1929 // Find the array bound.
1930 ExprResult BoundExpr;
1931 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT))
1932 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(),
1933 Context.getPointerDiffType(),
1935 else if (const VariableArrayType *VAT =
1936 dyn_cast<VariableArrayType>(UnqAT))
1937 BoundExpr = VAT->getSizeExpr();
1939 // Can't be a DependentSizedArrayType or an IncompleteArrayType since
1940 // UnqAT is not incomplete and Range is not type-dependent.
1941 llvm_unreachable("Unexpected array type in for-range");
1944 // end-expr is __range + __bound.
1945 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(),
1947 if (EndExpr.isInvalid())
1949 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc,
1950 diag::err_for_range_iter_deduction_failure)) {
1951 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
1955 OverloadCandidateSet CandidateSet(RangeLoc);
1956 Sema::BeginEndFunction BEFFailure;
1957 ForRangeStatus RangeStatus =
1958 BuildNonArrayForRange(*this, S, BeginRangeRef.get(),
1959 EndRangeRef.get(), RangeType,
1960 BeginVar, EndVar, ColonLoc, &CandidateSet,
1961 &BeginExpr, &EndExpr, &BEFFailure);
1963 // If building the range failed, try dereferencing the range expression
1964 // unless a diagnostic was issued or the end function is problematic.
1965 if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction &&
1966 BEFFailure == BEF_begin) {
1967 StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc,
1968 LoopVarDecl, ColonLoc,
1971 if (SR.isInvalid() || SR.isUsable())
1975 // Otherwise, emit diagnostics if we haven't already.
1976 if (RangeStatus == FRS_NoViableFunction) {
1977 Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get();
1978 Diag(Range->getLocStart(), diag::err_for_range_invalid)
1979 << RangeLoc << Range->getType() << BEFFailure;
1980 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Range);
1982 // Return an error if no fix was discovered.
1983 if (RangeStatus != FRS_Success)
1987 assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() &&
1988 "invalid range expression in for loop");
1990 // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same.
1991 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
1992 if (!Context.hasSameType(BeginType, EndType)) {
1993 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ)
1994 << BeginType << EndType;
1995 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1996 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
1999 Decl *BeginEndDecls[] = { BeginVar, EndVar };
2000 // Claim the type doesn't contain auto: we've already done the checking.
2001 DeclGroupPtrTy BeginEndGroup =
2002 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false);
2003 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc);
2005 const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
2006 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2007 VK_LValue, ColonLoc);
2008 if (BeginRef.isInvalid())
2011 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(),
2012 VK_LValue, ColonLoc);
2013 if (EndRef.isInvalid())
2016 // Build and check __begin != __end expression.
2017 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal,
2018 BeginRef.get(), EndRef.get());
2019 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get());
2020 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get());
2021 if (NotEqExpr.isInvalid()) {
2022 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2023 << RangeLoc << 0 << BeginRangeRef.get()->getType();
2024 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2025 if (!Context.hasSameType(BeginType, EndType))
2026 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
2030 // Build and check ++__begin expression.
2031 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2032 VK_LValue, ColonLoc);
2033 if (BeginRef.isInvalid())
2036 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get());
2037 IncrExpr = ActOnFinishFullExpr(IncrExpr.get());
2038 if (IncrExpr.isInvalid()) {
2039 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2040 << RangeLoc << 2 << BeginRangeRef.get()->getType() ;
2041 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2045 // Build and check *__begin expression.
2046 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
2047 VK_LValue, ColonLoc);
2048 if (BeginRef.isInvalid())
2051 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get());
2052 if (DerefExpr.isInvalid()) {
2053 Diag(RangeLoc, diag::note_for_range_invalid_iterator)
2054 << RangeLoc << 1 << BeginRangeRef.get()->getType();
2055 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2059 // Attach *__begin as initializer for VD. Don't touch it if we're just
2060 // trying to determine whether this would be a valid range.
2061 if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) {
2062 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false,
2063 /*TypeMayContainAuto=*/true);
2064 if (LoopVar->isInvalidDecl())
2065 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
2068 // The range is implicitly used as a placeholder when it is dependent.
2069 RangeVar->setUsed();
2072 // Don't bother to actually allocate the result if we're just trying to
2073 // determine whether it would be valid.
2074 if (Kind == BFRK_Check)
2075 return StmtResult();
2077 return Owned(new (Context) CXXForRangeStmt(RangeDS,
2078 cast_or_null<DeclStmt>(BeginEndDecl.get()),
2079 NotEqExpr.take(), IncrExpr.take(),
2080 LoopVarDS, /*Body=*/0, ForLoc,
2081 ColonLoc, RParenLoc));
2084 /// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach
2086 StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) {
2089 ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S);
2091 ForStmt->setBody(B);
2095 /// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement.
2096 /// This is a separate step from ActOnCXXForRangeStmt because analysis of the
2097 /// body cannot be performed until after the type of the range variable is
2099 StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) {
2103 if (isa<ObjCForCollectionStmt>(S))
2104 return FinishObjCForCollectionStmt(S, B);
2106 CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S);
2107 ForStmt->setBody(B);
2109 DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B,
2110 diag::warn_empty_range_based_for_body);
2115 StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc,
2116 SourceLocation LabelLoc,
2117 LabelDecl *TheDecl) {
2118 getCurFunction()->setHasBranchIntoScope();
2120 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc));
2124 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
2126 // Convert operand to void*
2127 if (!E->isTypeDependent()) {
2128 QualType ETy = E->getType();
2129 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
2130 ExprResult ExprRes = Owned(E);
2131 AssignConvertType ConvTy =
2132 CheckSingleAssignmentConstraints(DestTy, ExprRes);
2133 if (ExprRes.isInvalid())
2136 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
2140 ExprResult ExprRes = ActOnFinishFullExpr(E);
2141 if (ExprRes.isInvalid())
2145 getCurFunction()->setHasIndirectGoto();
2147 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E));
2151 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
2152 Scope *S = CurScope->getContinueParent();
2154 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
2155 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
2158 return Owned(new (Context) ContinueStmt(ContinueLoc));
2162 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
2163 Scope *S = CurScope->getBreakParent();
2165 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
2166 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
2169 return Owned(new (Context) BreakStmt(BreakLoc));
2172 /// \brief Determine whether the given expression is a candidate for
2173 /// copy elision in either a return statement or a throw expression.
2175 /// \param ReturnType If we're determining the copy elision candidate for
2176 /// a return statement, this is the return type of the function. If we're
2177 /// determining the copy elision candidate for a throw expression, this will
2180 /// \param E The expression being returned from the function or block, or
2183 /// \param AllowFunctionParameter Whether we allow function parameters to
2184 /// be considered NRVO candidates. C++ prohibits this for NRVO itself, but
2185 /// we re-use this logic to determine whether we should try to move as part of
2186 /// a return or throw (which does allow function parameters).
2188 /// \returns The NRVO candidate variable, if the return statement may use the
2189 /// NRVO, or NULL if there is no such candidate.
2190 const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType,
2192 bool AllowFunctionParameter) {
2193 QualType ExprType = E->getType();
2194 // - in a return statement in a function with ...
2195 // ... a class return type ...
2196 if (!ReturnType.isNull()) {
2197 if (!ReturnType->isRecordType())
2199 // ... the same cv-unqualified type as the function return type ...
2200 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType))
2204 // ... the expression is the name of a non-volatile automatic object
2205 // (other than a function or catch-clause parameter)) ...
2206 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
2207 if (!DR || DR->refersToEnclosingLocal())
2209 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
2213 // ...object (other than a function or catch-clause parameter)...
2214 if (VD->getKind() != Decl::Var &&
2215 !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar))
2217 if (VD->isExceptionVariable()) return 0;
2220 if (!VD->hasLocalStorage()) return 0;
2222 // ...non-volatile...
2223 if (VD->getType().isVolatileQualified()) return 0;
2224 if (VD->getType()->isReferenceType()) return 0;
2226 // __block variables can't be allocated in a way that permits NRVO.
2227 if (VD->hasAttr<BlocksAttr>()) return 0;
2229 // Variables with higher required alignment than their type's ABI
2230 // alignment cannot use NRVO.
2231 if (VD->hasAttr<AlignedAttr>() &&
2232 Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType()))
2238 /// \brief Perform the initialization of a potentially-movable value, which
2239 /// is the result of return value.
2241 /// This routine implements C++0x [class.copy]p33, which attempts to treat
2242 /// returned lvalues as rvalues in certain cases (to prefer move construction),
2243 /// then falls back to treating them as lvalues if that failed.
2245 Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
2246 const VarDecl *NRVOCandidate,
2247 QualType ResultType,
2250 // C++0x [class.copy]p33:
2251 // When the criteria for elision of a copy operation are met or would
2252 // be met save for the fact that the source object is a function
2253 // parameter, and the object to be copied is designated by an lvalue,
2254 // overload resolution to select the constructor for the copy is first
2255 // performed as if the object were designated by an rvalue.
2256 ExprResult Res = ExprError();
2258 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) {
2259 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack,
2260 Value->getType(), CK_NoOp, Value, VK_XValue);
2262 Expr *InitExpr = &AsRvalue;
2263 InitializationKind Kind
2264 = InitializationKind::CreateCopy(Value->getLocStart(),
2265 Value->getLocStart());
2266 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1);
2268 // [...] If overload resolution fails, or if the type of the first
2269 // parameter of the selected constructor is not an rvalue reference
2270 // to the object's type (possibly cv-qualified), overload resolution
2271 // is performed again, considering the object as an lvalue.
2273 for (InitializationSequence::step_iterator Step = Seq.step_begin(),
2274 StepEnd = Seq.step_end();
2275 Step != StepEnd; ++Step) {
2276 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization)
2279 CXXConstructorDecl *Constructor
2280 = cast<CXXConstructorDecl>(Step->Function.Function);
2282 const RValueReferenceType *RRefType
2283 = Constructor->getParamDecl(0)->getType()
2284 ->getAs<RValueReferenceType>();
2286 // If we don't meet the criteria, break out now.
2288 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(),
2289 Context.getTypeDeclType(Constructor->getParent())))
2292 // Promote "AsRvalue" to the heap, since we now need this
2293 // expression node to persist.
2294 Value = ImplicitCastExpr::Create(Context, Value->getType(),
2295 CK_NoOp, Value, 0, VK_XValue);
2297 // Complete type-checking the initialization of the return type
2298 // using the constructor we found.
2299 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1));
2304 // Either we didn't meet the criteria for treating an lvalue as an rvalue,
2305 // above, or overload resolution failed. Either way, we need to try
2306 // (again) now with the return value expression as written.
2307 if (Res.isInvalid())
2308 Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
2313 /// ActOnCapScopeReturnStmt - Utility routine to type-check return statements
2314 /// for capturing scopes.
2317 Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
2318 // If this is the first return we've seen, infer the return type.
2319 // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those
2320 // rules which allows multiple return statements.
2321 CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
2322 QualType FnRetType = CurCap->ReturnType;
2324 // For blocks/lambdas with implicit return types, we check each return
2325 // statement individually, and deduce the common return type when the block
2326 // or lambda is completed.
2327 if (CurCap->HasImplicitReturnType) {
2328 if (RetValExp && !isa<InitListExpr>(RetValExp)) {
2329 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
2330 if (Result.isInvalid())
2332 RetValExp = Result.take();
2334 if (!RetValExp->isTypeDependent())
2335 FnRetType = RetValExp->getType();
2337 FnRetType = CurCap->ReturnType = Context.DependentTy;
2340 // C++11 [expr.lambda.prim]p4 bans inferring the result from an
2341 // initializer list, because it is not an expression (even
2342 // though we represent it as one). We still deduce 'void'.
2343 Diag(ReturnLoc, diag::err_lambda_return_init_list)
2344 << RetValExp->getSourceRange();
2347 FnRetType = Context.VoidTy;
2350 // Although we'll properly infer the type of the block once it's completed,
2351 // make sure we provide a return type now for better error recovery.
2352 if (CurCap->ReturnType.isNull())
2353 CurCap->ReturnType = FnRetType;
2355 assert(!FnRetType.isNull());
2357 if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) {
2358 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) {
2359 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr);
2363 LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(CurCap);
2364 if (LSI->CallOperator->getType()->getAs<FunctionType>()->getNoReturnAttr()){
2365 Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr);
2370 // Otherwise, verify that this result type matches the previous one. We are
2371 // pickier with blocks than for normal functions because we don't have GCC
2372 // compatibility to worry about here.
2373 const VarDecl *NRVOCandidate = 0;
2374 if (FnRetType->isDependentType()) {
2375 // Delay processing for now. TODO: there are lots of dependent
2376 // types we can conclusively prove aren't void.
2377 } else if (FnRetType->isVoidType()) {
2378 if (RetValExp && !isa<InitListExpr>(RetValExp) &&
2379 !(getLangOpts().CPlusPlus &&
2380 (RetValExp->isTypeDependent() ||
2381 RetValExp->getType()->isVoidType()))) {
2382 if (!getLangOpts().CPlusPlus &&
2383 RetValExp->getType()->isVoidType())
2384 Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2;
2386 Diag(ReturnLoc, diag::err_return_block_has_expr);
2390 } else if (!RetValExp) {
2391 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
2392 } else if (!RetValExp->isTypeDependent()) {
2393 // we have a non-void block with an expression, continue checking
2395 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
2396 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
2399 // In C++ the return statement is handled via a copy initialization.
2400 // the C version of which boils down to CheckSingleAssignmentConstraints.
2401 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false);
2402 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
2404 NRVOCandidate != 0);
2405 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
2406 FnRetType, RetValExp);
2407 if (Res.isInvalid()) {
2408 // FIXME: Cleanup temporaries here, anyway?
2411 RetValExp = Res.take();
2412 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
2416 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
2419 RetValExp = ER.take();
2421 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp,
2424 // If we need to check for the named return value optimization,
2425 // or if we need to infer the return type,
2426 // save the return statement in our scope for later processing.
2427 if (CurCap->HasImplicitReturnType ||
2428 (getLangOpts().CPlusPlus && FnRetType->isRecordType() &&
2429 !CurContext->isDependentContext()))
2430 FunctionScopes.back()->Returns.push_back(Result);
2432 return Owned(Result);
2436 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
2437 // Check for unexpanded parameter packs.
2438 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
2441 if (isa<CapturingScopeInfo>(getCurFunction()))
2442 return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);
2445 QualType RelatedRetType;
2446 if (const FunctionDecl *FD = getCurFunctionDecl()) {
2447 FnRetType = FD->getResultType();
2448 if (FD->isNoReturn())
2449 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
2450 << FD->getDeclName();
2451 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
2452 FnRetType = MD->getResultType();
2453 if (MD->hasRelatedResultType() && MD->getClassInterface()) {
2454 // In the implementation of a method with a related return type, the
2455 // type used to type-check the validity of return statements within the
2456 // method body is a pointer to the type of the class being implemented.
2457 RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface());
2458 RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType);
2460 } else // If we don't have a function/method context, bail.
2463 ReturnStmt *Result = 0;
2464 if (FnRetType->isVoidType()) {
2466 if (isa<InitListExpr>(RetValExp)) {
2467 // We simply never allow init lists as the return value of void
2468 // functions. This is compatible because this was never allowed before,
2469 // so there's no legacy code to deal with.
2470 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
2471 int FunctionKind = 0;
2472 if (isa<ObjCMethodDecl>(CurDecl))
2474 else if (isa<CXXConstructorDecl>(CurDecl))
2476 else if (isa<CXXDestructorDecl>(CurDecl))
2479 Diag(ReturnLoc, diag::err_return_init_list)
2480 << CurDecl->getDeclName() << FunctionKind
2481 << RetValExp->getSourceRange();
2483 // Drop the expression.
2485 } else if (!RetValExp->isTypeDependent()) {
2486 // C99 6.8.6.4p1 (ext_ since GCC warns)
2487 unsigned D = diag::ext_return_has_expr;
2488 if (RetValExp->getType()->isVoidType())
2489 D = diag::ext_return_has_void_expr;
2491 ExprResult Result = Owned(RetValExp);
2492 Result = IgnoredValueConversions(Result.take());
2493 if (Result.isInvalid())
2495 RetValExp = Result.take();
2496 RetValExp = ImpCastExprToType(RetValExp,
2497 Context.VoidTy, CK_ToVoid).take();
2500 // return (some void expression); is legal in C++.
2501 if (D != diag::ext_return_has_void_expr ||
2502 !getLangOpts().CPlusPlus) {
2503 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
2505 int FunctionKind = 0;
2506 if (isa<ObjCMethodDecl>(CurDecl))
2508 else if (isa<CXXConstructorDecl>(CurDecl))
2510 else if (isa<CXXDestructorDecl>(CurDecl))
2514 << CurDecl->getDeclName() << FunctionKind
2515 << RetValExp->getSourceRange();
2520 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
2523 RetValExp = ER.take();
2527 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0);
2528 } else if (!RetValExp && !FnRetType->isDependentType()) {
2529 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4
2530 // C99 6.8.6.4p1 (ext_ since GCC warns)
2531 if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr;
2533 if (FunctionDecl *FD = getCurFunctionDecl())
2534 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
2536 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
2537 Result = new (Context) ReturnStmt(ReturnLoc);
2539 assert(RetValExp || FnRetType->isDependentType());
2540 const VarDecl *NRVOCandidate = 0;
2541 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
2542 // we have a non-void function with an expression, continue checking
2544 QualType RetType = (RelatedRetType.isNull() ? FnRetType : RelatedRetType);
2546 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
2547 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
2550 // In C++ the return statement is handled via a copy initialization,
2551 // the C version of which boils down to CheckSingleAssignmentConstraints.
2552 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false);
2553 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
2555 NRVOCandidate != 0);
2556 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
2557 RetType, RetValExp);
2558 if (Res.isInvalid()) {
2559 // FIXME: Clean up temporaries here anyway?
2562 RetValExp = Res.takeAs<Expr>();
2564 // If we have a related result type, we need to implicitly
2565 // convert back to the formal result type. We can't pretend to
2566 // initialize the result again --- we might end double-retaining
2567 // --- so instead we initialize a notional temporary; this can
2568 // lead to less-than-great diagnostics, but this stage is much
2569 // less likely to fail than the previous stage.
2570 if (!RelatedRetType.isNull()) {
2571 Entity = InitializedEntity::InitializeTemporary(FnRetType);
2572 Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp);
2573 if (Res.isInvalid()) {
2574 // FIXME: Clean up temporaries here anyway?
2577 RetValExp = Res.takeAs<Expr>();
2580 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
2584 ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc);
2587 RetValExp = ER.take();
2589 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate);
2592 // If we need to check for the named return value optimization, save the
2593 // return statement in our scope for later processing.
2594 if (getLangOpts().CPlusPlus && FnRetType->isRecordType() &&
2595 !CurContext->isDependentContext())
2596 FunctionScopes.back()->Returns.push_back(Result);
2598 return Owned(Result);
2602 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
2603 SourceLocation RParen, Decl *Parm,
2605 VarDecl *Var = cast_or_null<VarDecl>(Parm);
2606 if (Var && Var->isInvalidDecl())
2609 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body));
2613 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) {
2614 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body));
2618 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
2619 MultiStmtArg CatchStmts, Stmt *Finally) {
2620 if (!getLangOpts().ObjCExceptions)
2621 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try";
2623 getCurFunction()->setHasBranchProtectedScope();
2624 unsigned NumCatchStmts = CatchStmts.size();
2625 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try,
2631 StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) {
2633 ExprResult Result = DefaultLvalueConversion(Throw);
2634 if (Result.isInvalid())
2637 Result = ActOnFinishFullExpr(Result.take());
2638 if (Result.isInvalid())
2640 Throw = Result.take();
2642 QualType ThrowType = Throw->getType();
2643 // Make sure the expression type is an ObjC pointer or "void *".
2644 if (!ThrowType->isDependentType() &&
2645 !ThrowType->isObjCObjectPointerType()) {
2646 const PointerType *PT = ThrowType->getAs<PointerType>();
2647 if (!PT || !PT->getPointeeType()->isVoidType())
2648 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object)
2649 << Throw->getType() << Throw->getSourceRange());
2653 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw));
2657 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
2659 if (!getLangOpts().ObjCExceptions)
2660 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw";
2663 // @throw without an expression designates a rethrow (which much occur
2664 // in the context of an @catch clause).
2665 Scope *AtCatchParent = CurScope;
2666 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
2667 AtCatchParent = AtCatchParent->getParent();
2669 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch));
2671 return BuildObjCAtThrowStmt(AtLoc, Throw);
2675 Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) {
2676 ExprResult result = DefaultLvalueConversion(operand);
2677 if (result.isInvalid())
2679 operand = result.take();
2681 // Make sure the expression type is an ObjC pointer or "void *".
2682 QualType type = operand->getType();
2683 if (!type->isDependentType() &&
2684 !type->isObjCObjectPointerType()) {
2685 const PointerType *pointerType = type->getAs<PointerType>();
2686 if (!pointerType || !pointerType->getPointeeType()->isVoidType())
2687 return Diag(atLoc, diag::error_objc_synchronized_expects_object)
2688 << type << operand->getSourceRange();
2691 // The operand to @synchronized is a full-expression.
2692 return ActOnFinishFullExpr(operand);
2696 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr,
2698 // We can't jump into or indirect-jump out of a @synchronized block.
2699 getCurFunction()->setHasBranchProtectedScope();
2700 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody));
2703 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
2704 /// and creates a proper catch handler from them.
2706 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl,
2707 Stmt *HandlerBlock) {
2708 // There's nothing to test that ActOnExceptionDecl didn't already test.
2709 return Owned(new (Context) CXXCatchStmt(CatchLoc,
2710 cast_or_null<VarDecl>(ExDecl),
2715 Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) {
2716 getCurFunction()->setHasBranchProtectedScope();
2717 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body));
2722 class TypeWithHandler {
2726 TypeWithHandler(const QualType &type, CXXCatchStmt *statement)
2727 : t(type), stmt(statement) {}
2729 // An arbitrary order is fine as long as it places identical
2730 // types next to each other.
2731 bool operator<(const TypeWithHandler &y) const {
2732 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr())
2734 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr())
2737 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc();
2740 bool operator==(const TypeWithHandler& other) const {
2741 return t == other.t;
2744 CXXCatchStmt *getCatchStmt() const { return stmt; }
2745 SourceLocation getTypeSpecStartLoc() const {
2746 return stmt->getExceptionDecl()->getTypeSpecStartLoc();
2752 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of
2753 /// handlers and creates a try statement from them.
2755 Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
2756 MultiStmtArg RawHandlers) {
2757 // Don't report an error if 'try' is used in system headers.
2758 if (!getLangOpts().CXXExceptions &&
2759 !getSourceManager().isInSystemHeader(TryLoc))
2760 Diag(TryLoc, diag::err_exceptions_disabled) << "try";
2762 unsigned NumHandlers = RawHandlers.size();
2763 assert(NumHandlers > 0 &&
2764 "The parser shouldn't call this if there are no handlers.");
2765 Stmt **Handlers = RawHandlers.data();
2767 SmallVector<TypeWithHandler, 8> TypesWithHandlers;
2769 for (unsigned i = 0; i < NumHandlers; ++i) {
2770 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]);
2771 if (!Handler->getExceptionDecl()) {
2772 if (i < NumHandlers - 1)
2773 return StmtError(Diag(Handler->getLocStart(),
2774 diag::err_early_catch_all));
2779 const QualType CaughtType = Handler->getCaughtType();
2780 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType);
2781 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler));
2784 // Detect handlers for the same type as an earlier one.
2785 if (NumHandlers > 1) {
2786 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end());
2788 TypeWithHandler prev = TypesWithHandlers[0];
2789 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) {
2790 TypeWithHandler curr = TypesWithHandlers[i];
2793 Diag(curr.getTypeSpecStartLoc(),
2794 diag::warn_exception_caught_by_earlier_handler)
2795 << curr.getCatchStmt()->getCaughtType().getAsString();
2796 Diag(prev.getTypeSpecStartLoc(),
2797 diag::note_previous_exception_handler)
2798 << prev.getCatchStmt()->getCaughtType().getAsString();
2805 getCurFunction()->setHasBranchProtectedScope();
2807 // FIXME: We should detect handlers that cannot catch anything because an
2808 // earlier handler catches a superclass. Need to find a method that is not
2809 // quadratic for this.
2810 // Neither of these are explicitly forbidden, but every compiler detects them
2813 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock,
2814 llvm::makeArrayRef(Handlers, NumHandlers)));
2818 Sema::ActOnSEHTryBlock(bool IsCXXTry,
2819 SourceLocation TryLoc,
2822 assert(TryBlock && Handler);
2824 getCurFunction()->setHasBranchProtectedScope();
2826 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler));
2830 Sema::ActOnSEHExceptBlock(SourceLocation Loc,
2833 assert(FilterExpr && Block);
2835 if(!FilterExpr->getType()->isIntegerType()) {
2836 return StmtError(Diag(FilterExpr->getExprLoc(),
2837 diag::err_filter_expression_integral)
2838 << FilterExpr->getType());
2841 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block));
2845 Sema::ActOnSEHFinallyBlock(SourceLocation Loc,
2848 return Owned(SEHFinallyStmt::Create(Context,Loc,Block));
2851 StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
2853 NestedNameSpecifierLoc QualifierLoc,
2854 DeclarationNameInfo NameInfo,
2857 return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists,
2858 QualifierLoc, NameInfo,
2859 cast<CompoundStmt>(Nested));
2863 StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
2866 UnqualifiedId &Name,
2868 return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists,
2869 SS.getWithLocInContext(Context),
2870 GetNameFromUnqualifiedId(Name),