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/Sema/Scope.h"
16 #include "clang/Sema/ScopeInfo.h"
17 #include "clang/Sema/Initialization.h"
18 #include "clang/Sema/Lookup.h"
19 #include "clang/AST/APValue.h"
20 #include "clang/AST/ASTContext.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/AST/ExprObjC.h"
24 #include "clang/AST/StmtObjC.h"
25 #include "clang/AST/StmtCXX.h"
26 #include "clang/AST/TypeLoc.h"
27 #include "clang/Lex/Preprocessor.h"
28 #include "clang/Basic/TargetInfo.h"
29 #include "llvm/ADT/ArrayRef.h"
30 #include "llvm/ADT/STLExtras.h"
31 #include "llvm/ADT/SmallVector.h"
32 using namespace clang;
35 StmtResult Sema::ActOnExprStmt(FullExprArg expr) {
37 if (!E) // FIXME: FullExprArg has no error state?
40 // C99 6.8.3p2: The expression in an expression statement is evaluated as a
41 // void expression for its side effects. Conversion to void allows any
42 // operand, even incomplete types.
44 // Same thing in for stmt first clause (when expr) and third clause.
45 return Owned(static_cast<Stmt*>(E));
49 StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc,
50 bool HasLeadingEmptyMacro) {
51 return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro));
54 StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc,
55 SourceLocation EndLoc) {
56 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
58 // If we have an invalid decl, just return an error.
59 if (DG.isNull()) return StmtError();
61 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
64 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
65 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
67 // If we have an invalid decl, just return.
68 if (DG.isNull() || !DG.isSingleDecl()) return;
69 VarDecl *var = cast<VarDecl>(DG.getSingleDecl());
71 // suppress any potential 'unused variable' warning.
74 // foreach variables are never actually initialized in the way that
75 // the parser came up with.
78 // In ARC, we don't need to retain the iteration variable of a fast
79 // enumeration loop. Rather than actually trying to catch that
80 // during declaration processing, we remove the consequences here.
81 if (getLangOptions().ObjCAutoRefCount) {
82 QualType type = var->getType();
84 // Only do this if we inferred the lifetime. Inferred lifetime
85 // will show up as a local qualifier because explicit lifetime
86 // should have shown up as an AttributedType instead.
87 if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) {
88 // Add 'const' and mark the variable as pseudo-strong.
89 var->setType(type.withConst());
90 var->setARCPseudoStrong(true);
95 /// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='.
97 /// Adding a cast to void (or other expression wrappers) will prevent the
98 /// warning from firing.
99 static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) {
101 bool IsNotEqual, CanAssign;
103 if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) {
104 if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE)
107 Loc = Op->getOperatorLoc();
108 IsNotEqual = Op->getOpcode() == BO_NE;
109 CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue();
110 } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) {
111 if (Op->getOperator() != OO_EqualEqual &&
112 Op->getOperator() != OO_ExclaimEqual)
115 Loc = Op->getOperatorLoc();
116 IsNotEqual = Op->getOperator() == OO_ExclaimEqual;
117 CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue();
119 // Not a typo-prone comparison.
123 // Suppress warnings when the operator, suspicious as it may be, comes from
124 // a macro expansion.
128 S.Diag(Loc, diag::warn_unused_comparison)
129 << (unsigned)IsNotEqual << E->getSourceRange();
131 // If the LHS is a plausible entity to assign to, provide a fixit hint to
132 // correct common typos.
135 S.Diag(Loc, diag::note_inequality_comparison_to_or_assign)
136 << FixItHint::CreateReplacement(Loc, "|=");
138 S.Diag(Loc, diag::note_equality_comparison_to_assign)
139 << FixItHint::CreateReplacement(Loc, "=");
145 void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
146 if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S))
147 return DiagnoseUnusedExprResult(Label->getSubStmt());
149 const Expr *E = dyn_cast_or_null<Expr>(S);
155 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context))
158 // Okay, we have an unused result. Depending on what the base expression is,
159 // we might want to make a more specific diagnostic. Check for one of these
161 unsigned DiagID = diag::warn_unused_expr;
162 if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E))
163 E = Temps->getSubExpr();
164 if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E))
165 E = TempExpr->getSubExpr();
167 if (DiagnoseUnusedComparison(*this, E))
170 E = E->IgnoreParenImpCasts();
171 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
172 if (E->getType()->isVoidType())
175 // If the callee has attribute pure, const, or warn_unused_result, warn with
176 // a more specific message to make it clear what is happening.
177 if (const Decl *FD = CE->getCalleeDecl()) {
178 if (FD->getAttr<WarnUnusedResultAttr>()) {
179 Diag(Loc, diag::warn_unused_result) << R1 << R2;
182 if (FD->getAttr<PureAttr>()) {
183 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
186 if (FD->getAttr<ConstAttr>()) {
187 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
191 } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
192 if (getLangOptions().ObjCAutoRefCount && ME->isDelegateInitCall()) {
193 Diag(Loc, diag::err_arc_unused_init_message) << R1;
196 const ObjCMethodDecl *MD = ME->getMethodDecl();
197 if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
198 Diag(Loc, diag::warn_unused_result) << R1 << R2;
201 } else if (isa<ObjCPropertyRefExpr>(E)) {
202 DiagID = diag::warn_unused_property_expr;
203 } else if (const CXXFunctionalCastExpr *FC
204 = dyn_cast<CXXFunctionalCastExpr>(E)) {
205 if (isa<CXXConstructExpr>(FC->getSubExpr()) ||
206 isa<CXXTemporaryObjectExpr>(FC->getSubExpr()))
209 // Diagnose "(void*) blah" as a typo for "(void) blah".
210 else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) {
211 TypeSourceInfo *TI = CE->getTypeInfoAsWritten();
212 QualType T = TI->getType();
214 // We really do want to use the non-canonical type here.
215 if (T == Context.VoidPtrTy) {
216 PointerTypeLoc TL = cast<PointerTypeLoc>(TI->getTypeLoc());
218 Diag(Loc, diag::warn_unused_voidptr)
219 << FixItHint::CreateRemoval(TL.getStarLoc());
224 DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2);
228 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
229 MultiStmtArg elts, bool isStmtExpr) {
230 unsigned NumElts = elts.size();
231 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release());
232 // If we're in C89 mode, check that we don't have any decls after stmts. If
233 // so, emit an extension diagnostic.
234 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) {
235 // Note that __extension__ can be around a decl.
237 // Skip over all declarations.
238 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
241 // We found the end of the list or a statement. Scan for another declstmt.
242 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
246 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
247 Diag(D->getLocation(), diag::ext_mixed_decls_code);
250 // Warn about unused expressions in statements.
251 for (unsigned i = 0; i != NumElts; ++i) {
252 // Ignore statements that are last in a statement expression.
253 if (isStmtExpr && i == NumElts - 1)
256 DiagnoseUnusedExprResult(Elts[i]);
259 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
263 Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal,
264 SourceLocation DotDotDotLoc, Expr *RHSVal,
265 SourceLocation ColonLoc) {
266 assert((LHSVal != 0) && "missing expression in case statement");
268 // C99 6.8.4.2p3: The expression shall be an integer constant.
269 // However, GCC allows any evaluatable integer expression.
270 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() &&
271 VerifyIntegerConstantExpression(LHSVal))
274 // GCC extension: The expression shall be an integer constant.
276 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() &&
277 VerifyIntegerConstantExpression(RHSVal)) {
278 RHSVal = 0; // Recover by just forgetting about it.
281 if (getCurFunction()->SwitchStack.empty()) {
282 Diag(CaseLoc, diag::err_case_not_in_switch);
286 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
288 getCurFunction()->SwitchStack.back()->addSwitchCase(CS);
292 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
293 void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) {
294 DiagnoseUnusedExprResult(SubStmt);
296 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt);
297 CS->setSubStmt(SubStmt);
301 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
302 Stmt *SubStmt, Scope *CurScope) {
303 DiagnoseUnusedExprResult(SubStmt);
305 if (getCurFunction()->SwitchStack.empty()) {
306 Diag(DefaultLoc, diag::err_default_not_in_switch);
307 return Owned(SubStmt);
310 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
311 getCurFunction()->SwitchStack.back()->addSwitchCase(DS);
316 Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
317 SourceLocation ColonLoc, Stmt *SubStmt) {
319 // If the label was multiply defined, reject it now.
320 if (TheDecl->getStmt()) {
321 Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName();
322 Diag(TheDecl->getLocation(), diag::note_previous_definition);
323 return Owned(SubStmt);
326 // Otherwise, things are good. Fill in the declaration and return it.
327 LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt);
328 TheDecl->setStmt(LS);
329 if (!TheDecl->isGnuLocal())
330 TheDecl->setLocation(IdentLoc);
335 Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar,
336 Stmt *thenStmt, SourceLocation ElseLoc,
338 ExprResult CondResult(CondVal.release());
340 VarDecl *ConditionVar = 0;
342 ConditionVar = cast<VarDecl>(CondVar);
343 CondResult = CheckConditionVariable(ConditionVar, IfLoc, true);
344 if (CondResult.isInvalid())
347 Expr *ConditionExpr = CondResult.takeAs<Expr>();
351 DiagnoseUnusedExprResult(thenStmt);
353 // Warn if the if block has a null body without an else value.
354 // this helps prevent bugs due to typos, such as
359 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
360 // But do not warn if the body is a macro that expands to nothing, e.g:
366 if (!stmt->hasLeadingEmptyMacro())
367 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
370 DiagnoseUnusedExprResult(elseStmt);
372 return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr,
373 thenStmt, ElseLoc, elseStmt));
376 /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
377 /// the specified width and sign. If an overflow occurs, detect it and emit
378 /// the specified diagnostic.
379 void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val,
380 unsigned NewWidth, bool NewSign,
383 // Perform a conversion to the promoted condition type if needed.
384 if (NewWidth > Val.getBitWidth()) {
385 // If this is an extension, just do it.
386 Val = Val.extend(NewWidth);
387 Val.setIsSigned(NewSign);
389 // If the input was signed and negative and the output is
390 // unsigned, don't bother to warn: this is implementation-defined
392 // FIXME: Introduce a second, default-ignored warning for this case?
393 } else if (NewWidth < Val.getBitWidth()) {
394 // If this is a truncation, check for overflow.
395 llvm::APSInt ConvVal(Val);
396 ConvVal = ConvVal.trunc(NewWidth);
397 ConvVal.setIsSigned(NewSign);
398 ConvVal = ConvVal.extend(Val.getBitWidth());
399 ConvVal.setIsSigned(Val.isSigned());
401 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10);
403 // Regardless of whether a diagnostic was emitted, really do the
405 Val = Val.trunc(NewWidth);
406 Val.setIsSigned(NewSign);
407 } else if (NewSign != Val.isSigned()) {
408 // Convert the sign to match the sign of the condition. This can cause
409 // overflow as well: unsigned(INTMIN)
410 // We don't diagnose this overflow, because it is implementation-defined
412 // FIXME: Introduce a second, default-ignored warning for this case?
413 llvm::APSInt OldVal(Val);
414 Val.setIsSigned(NewSign);
419 struct CaseCompareFunctor {
420 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
421 const llvm::APSInt &RHS) {
422 return LHS.first < RHS;
424 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
425 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
426 return LHS.first < RHS.first;
428 bool operator()(const llvm::APSInt &LHS,
429 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
430 return LHS < RHS.first;
435 /// CmpCaseVals - Comparison predicate for sorting case values.
437 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
438 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
439 if (lhs.first < rhs.first)
442 if (lhs.first == rhs.first &&
443 lhs.second->getCaseLoc().getRawEncoding()
444 < rhs.second->getCaseLoc().getRawEncoding())
449 /// CmpEnumVals - Comparison predicate for sorting enumeration values.
451 static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
452 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
454 return lhs.first < rhs.first;
457 /// EqEnumVals - Comparison preficate for uniqing enumeration values.
459 static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
460 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
462 return lhs.first == rhs.first;
465 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
466 /// potentially integral-promoted expression @p expr.
467 static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) {
468 if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr))
469 expr = cleanups->getSubExpr();
470 while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) {
471 if (impcast->getCastKind() != CK_IntegralCast) break;
472 expr = impcast->getSubExpr();
474 return expr->getType();
478 Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond,
480 ExprResult CondResult;
482 VarDecl *ConditionVar = 0;
484 ConditionVar = cast<VarDecl>(CondVar);
485 CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false);
486 if (CondResult.isInvalid())
489 Cond = CondResult.release();
496 = ConvertToIntegralOrEnumerationType(SwitchLoc, Cond,
497 PDiag(diag::err_typecheck_statement_requires_integer),
498 PDiag(diag::err_switch_incomplete_class_type)
499 << Cond->getSourceRange(),
500 PDiag(diag::err_switch_explicit_conversion),
501 PDiag(diag::note_switch_conversion),
502 PDiag(diag::err_switch_multiple_conversions),
503 PDiag(diag::note_switch_conversion),
505 if (CondResult.isInvalid()) return StmtError();
506 Cond = CondResult.take();
508 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
509 CondResult = UsualUnaryConversions(Cond);
510 if (CondResult.isInvalid()) return StmtError();
511 Cond = CondResult.take();
514 CheckImplicitConversions(Cond, SwitchLoc);
515 CondResult = MaybeCreateExprWithCleanups(Cond);
516 if (CondResult.isInvalid())
518 Cond = CondResult.take();
521 getCurFunction()->setHasBranchIntoScope();
523 SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond);
524 getCurFunction()->SwitchStack.push_back(SS);
528 static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) {
529 if (Val.getBitWidth() < BitWidth)
530 Val = Val.extend(BitWidth);
531 else if (Val.getBitWidth() > BitWidth)
532 Val = Val.trunc(BitWidth);
533 Val.setIsSigned(IsSigned);
537 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch,
539 SwitchStmt *SS = cast<SwitchStmt>(Switch);
540 assert(SS == getCurFunction()->SwitchStack.back() &&
541 "switch stack missing push/pop!");
543 SS->setBody(BodyStmt, SwitchLoc);
544 getCurFunction()->SwitchStack.pop_back();
546 Expr *CondExpr = SS->getCond();
547 if (!CondExpr) return StmtError();
549 QualType CondType = CondExpr->getType();
551 Expr *CondExprBeforePromotion = CondExpr;
552 QualType CondTypeBeforePromotion =
553 GetTypeBeforeIntegralPromotion(CondExprBeforePromotion);
556 // Integral promotions are performed (on the switch condition).
558 // A case value unrepresentable by the original switch condition
559 // type (before the promotion) doesn't make sense, even when it can
560 // be represented by the promoted type. Therefore we need to find
561 // the pre-promotion type of the switch condition.
562 if (!CondExpr->isTypeDependent()) {
563 // We have already converted the expression to an integral or enumeration
564 // type, when we started the switch statement. If we don't have an
565 // appropriate type now, just return an error.
566 if (!CondType->isIntegralOrEnumerationType())
569 if (CondExpr->isKnownToHaveBooleanValue()) {
570 // switch(bool_expr) {...} is often a programmer error, e.g.
571 // switch(n && mask) { ... } // Doh - should be "n & mask".
572 // One can always use an if statement instead of switch(bool_expr).
573 Diag(SwitchLoc, diag::warn_bool_switch_condition)
574 << CondExpr->getSourceRange();
578 // Get the bitwidth of the switched-on value before promotions. We must
579 // convert the integer case values to this width before comparison.
580 bool HasDependentValue
581 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
583 = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion);
585 = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType();
587 // Accumulate all of the case values in a vector so that we can sort them
588 // and detect duplicates. This vector contains the APInt for the case after
589 // it has been converted to the condition type.
590 typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
593 // Keep track of any GNU case ranges we see. The APSInt is the low value.
594 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
595 CaseRangesTy CaseRanges;
597 DefaultStmt *TheDefaultStmt = 0;
599 bool CaseListIsErroneous = false;
601 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
602 SC = SC->getNextSwitchCase()) {
604 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
605 if (TheDefaultStmt) {
606 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
607 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
609 // FIXME: Remove the default statement from the switch block so that
610 // we'll return a valid AST. This requires recursing down the AST and
611 // finding it, not something we are set up to do right now. For now,
612 // just lop the entire switch stmt out of the AST.
613 CaseListIsErroneous = true;
618 CaseStmt *CS = cast<CaseStmt>(SC);
620 // We already verified that the expression has a i-c-e value (C99
621 // 6.8.4.2p3) - get that value now.
622 Expr *Lo = CS->getLHS();
624 if (Lo->isTypeDependent() || Lo->isValueDependent()) {
625 HasDependentValue = true;
629 llvm::APSInt LoVal = Lo->EvaluateKnownConstInt(Context);
631 // Convert the value to the same width/sign as the condition.
632 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned,
634 diag::warn_case_value_overflow);
636 // If the LHS is not the same type as the condition, insert an implicit
638 Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take();
641 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
643 if (CS->getRHS()->isTypeDependent() ||
644 CS->getRHS()->isValueDependent()) {
645 HasDependentValue = true;
648 CaseRanges.push_back(std::make_pair(LoVal, CS));
650 CaseVals.push_back(std::make_pair(LoVal, CS));
654 if (!HasDependentValue) {
655 // If we don't have a default statement, check whether the
656 // condition is constant.
657 llvm::APSInt ConstantCondValue;
658 bool HasConstantCond = false;
659 bool ShouldCheckConstantCond = false;
660 if (!HasDependentValue && !TheDefaultStmt) {
661 Expr::EvalResult Result;
662 HasConstantCond = CondExprBeforePromotion->Evaluate(Result, Context);
663 if (HasConstantCond) {
664 assert(Result.Val.isInt() && "switch condition evaluated to non-int");
665 ConstantCondValue = Result.Val.getInt();
666 ShouldCheckConstantCond = true;
668 assert(ConstantCondValue.getBitWidth() == CondWidth &&
669 ConstantCondValue.isSigned() == CondIsSigned);
673 // Sort all the scalar case values so we can easily detect duplicates.
674 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
676 if (!CaseVals.empty()) {
677 for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) {
678 if (ShouldCheckConstantCond &&
679 CaseVals[i].first == ConstantCondValue)
680 ShouldCheckConstantCond = false;
682 if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) {
683 // If we have a duplicate, report it.
684 Diag(CaseVals[i].second->getLHS()->getLocStart(),
685 diag::err_duplicate_case) << CaseVals[i].first.toString(10);
686 Diag(CaseVals[i-1].second->getLHS()->getLocStart(),
687 diag::note_duplicate_case_prev);
688 // FIXME: We really want to remove the bogus case stmt from the
689 // substmt, but we have no way to do this right now.
690 CaseListIsErroneous = true;
695 // Detect duplicate case ranges, which usually don't exist at all in
697 if (!CaseRanges.empty()) {
698 // Sort all the case ranges by their low value so we can easily detect
699 // overlaps between ranges.
700 std::stable_sort(CaseRanges.begin(), CaseRanges.end());
702 // Scan the ranges, computing the high values and removing empty ranges.
703 std::vector<llvm::APSInt> HiVals;
704 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
705 llvm::APSInt &LoVal = CaseRanges[i].first;
706 CaseStmt *CR = CaseRanges[i].second;
707 Expr *Hi = CR->getRHS();
708 llvm::APSInt HiVal = Hi->EvaluateKnownConstInt(Context);
710 // Convert the value to the same width/sign as the condition.
711 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned,
713 diag::warn_case_value_overflow);
715 // If the LHS is not the same type as the condition, insert an implicit
717 Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take();
720 // If the low value is bigger than the high value, the case is empty.
722 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range)
723 << SourceRange(CR->getLHS()->getLocStart(),
725 CaseRanges.erase(CaseRanges.begin()+i);
730 if (ShouldCheckConstantCond &&
731 LoVal <= ConstantCondValue &&
732 ConstantCondValue <= HiVal)
733 ShouldCheckConstantCond = false;
735 HiVals.push_back(HiVal);
738 // Rescan the ranges, looking for overlap with singleton values and other
739 // ranges. Since the range list is sorted, we only need to compare case
740 // ranges with their neighbors.
741 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
742 llvm::APSInt &CRLo = CaseRanges[i].first;
743 llvm::APSInt &CRHi = HiVals[i];
744 CaseStmt *CR = CaseRanges[i].second;
746 // Check to see whether the case range overlaps with any
748 CaseStmt *OverlapStmt = 0;
749 llvm::APSInt OverlapVal(32);
751 // Find the smallest value >= the lower bound. If I is in the
752 // case range, then we have overlap.
753 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
754 CaseVals.end(), CRLo,
755 CaseCompareFunctor());
756 if (I != CaseVals.end() && I->first < CRHi) {
757 OverlapVal = I->first; // Found overlap with scalar.
758 OverlapStmt = I->second;
761 // Find the smallest value bigger than the upper bound.
762 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
763 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
764 OverlapVal = (I-1)->first; // Found overlap with scalar.
765 OverlapStmt = (I-1)->second;
768 // Check to see if this case stmt overlaps with the subsequent
770 if (i && CRLo <= HiVals[i-1]) {
771 OverlapVal = HiVals[i-1]; // Found overlap with range.
772 OverlapStmt = CaseRanges[i-1].second;
776 // If we have a duplicate, report it.
777 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case)
778 << OverlapVal.toString(10);
779 Diag(OverlapStmt->getLHS()->getLocStart(),
780 diag::note_duplicate_case_prev);
781 // FIXME: We really want to remove the bogus case stmt from the
782 // substmt, but we have no way to do this right now.
783 CaseListIsErroneous = true;
788 // Complain if we have a constant condition and we didn't find a match.
789 if (!CaseListIsErroneous && ShouldCheckConstantCond) {
790 // TODO: it would be nice if we printed enums as enums, chars as
792 Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition)
793 << ConstantCondValue.toString(10)
794 << CondExpr->getSourceRange();
797 // Check to see if switch is over an Enum and handles all of its
798 // values. We only issue a warning if there is not 'default:', but
799 // we still do the analysis to preserve this information in the AST
800 // (which can be used by flow-based analyes).
802 const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>();
804 // If switch has default case, then ignore it.
805 if (!CaseListIsErroneous && !HasConstantCond && ET) {
806 const EnumDecl *ED = ET->getDecl();
807 typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64>
811 // Gather all enum values, set their type and sort them,
812 // allowing easier comparison with CaseVals.
813 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin();
814 EDI != ED->enumerator_end(); ++EDI) {
815 llvm::APSInt Val = EDI->getInitVal();
816 AdjustAPSInt(Val, CondWidth, CondIsSigned);
817 EnumVals.push_back(std::make_pair(Val, *EDI));
819 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
820 EnumValsTy::iterator EIend =
821 std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
823 // See which case values aren't in enum.
824 // TODO: we might want to check whether case values are out of the
825 // enum even if we don't want to check whether all cases are handled.
826 if (!TheDefaultStmt) {
827 EnumValsTy::const_iterator EI = EnumVals.begin();
828 for (CaseValsTy::const_iterator CI = CaseVals.begin();
829 CI != CaseVals.end(); CI++) {
830 while (EI != EIend && EI->first < CI->first)
832 if (EI == EIend || EI->first > CI->first)
833 Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
834 << ED->getDeclName();
836 // See which of case ranges aren't in enum
837 EI = EnumVals.begin();
838 for (CaseRangesTy::const_iterator RI = CaseRanges.begin();
839 RI != CaseRanges.end() && EI != EIend; RI++) {
840 while (EI != EIend && EI->first < RI->first)
843 if (EI == EIend || EI->first != RI->first) {
844 Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum)
845 << ED->getDeclName();
849 RI->second->getRHS()->EvaluateKnownConstInt(Context);
850 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
851 while (EI != EIend && EI->first < Hi)
853 if (EI == EIend || EI->first != Hi)
854 Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum)
855 << ED->getDeclName();
859 // Check which enum vals aren't in switch
860 CaseValsTy::const_iterator CI = CaseVals.begin();
861 CaseRangesTy::const_iterator RI = CaseRanges.begin();
862 bool hasCasesNotInSwitch = false;
864 SmallVector<DeclarationName,8> UnhandledNames;
866 for (EnumValsTy::const_iterator EI = EnumVals.begin(); EI != EIend; EI++){
867 // Drop unneeded case values
869 while (CI != CaseVals.end() && CI->first < EI->first)
872 if (CI != CaseVals.end() && CI->first == EI->first)
875 // Drop unneeded case ranges
876 for (; RI != CaseRanges.end(); RI++) {
878 RI->second->getRHS()->EvaluateKnownConstInt(Context);
879 AdjustAPSInt(Hi, CondWidth, CondIsSigned);
884 if (RI == CaseRanges.end() || EI->first < RI->first) {
885 hasCasesNotInSwitch = true;
887 UnhandledNames.push_back(EI->second->getDeclName());
891 // Produce a nice diagnostic if multiple values aren't handled.
892 switch (UnhandledNames.size()) {
895 Diag(CondExpr->getExprLoc(), diag::warn_missing_case1)
896 << UnhandledNames[0];
899 Diag(CondExpr->getExprLoc(), diag::warn_missing_case2)
900 << UnhandledNames[0] << UnhandledNames[1];
903 Diag(CondExpr->getExprLoc(), diag::warn_missing_case3)
904 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2];
907 Diag(CondExpr->getExprLoc(), diag::warn_missing_cases)
908 << (unsigned)UnhandledNames.size()
909 << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2];
913 if (!hasCasesNotInSwitch)
914 SS->setAllEnumCasesCovered();
918 // FIXME: If the case list was broken is some way, we don't have a good system
919 // to patch it up. Instead, just return the whole substmt as broken.
920 if (CaseListIsErroneous)
927 Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond,
928 Decl *CondVar, Stmt *Body) {
929 ExprResult CondResult(Cond.release());
931 VarDecl *ConditionVar = 0;
933 ConditionVar = cast<VarDecl>(CondVar);
934 CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true);
935 if (CondResult.isInvalid())
938 Expr *ConditionExpr = CondResult.take();
942 DiagnoseUnusedExprResult(Body);
944 return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr,
949 Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
950 SourceLocation WhileLoc, SourceLocation CondLParen,
951 Expr *Cond, SourceLocation CondRParen) {
952 assert(Cond && "ActOnDoStmt(): missing expression");
954 ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc);
955 if (CondResult.isInvalid() || CondResult.isInvalid())
957 Cond = CondResult.take();
959 CheckImplicitConversions(Cond, DoLoc);
960 CondResult = MaybeCreateExprWithCleanups(Cond);
961 if (CondResult.isInvalid())
963 Cond = CondResult.take();
965 DiagnoseUnusedExprResult(Body);
967 return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen));
971 Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
972 Stmt *First, FullExprArg second, Decl *secondVar,
974 SourceLocation RParenLoc, Stmt *Body) {
975 if (!getLangOptions().CPlusPlus) {
976 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
977 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
978 // declare identifiers for objects having storage class 'auto' or
980 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end();
982 VarDecl *VD = dyn_cast<VarDecl>(*DI);
983 if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage())
986 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
987 // FIXME: mark decl erroneous!
992 ExprResult SecondResult(second.release());
993 VarDecl *ConditionVar = 0;
995 ConditionVar = cast<VarDecl>(secondVar);
996 SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true);
997 if (SecondResult.isInvalid())
1001 Expr *Third = third.release().takeAs<Expr>();
1003 DiagnoseUnusedExprResult(First);
1004 DiagnoseUnusedExprResult(Third);
1005 DiagnoseUnusedExprResult(Body);
1007 return Owned(new (Context) ForStmt(Context, First,
1008 SecondResult.take(), ConditionVar,
1009 Third, Body, ForLoc, LParenLoc,
1013 /// In an Objective C collection iteration statement:
1015 /// x can be an arbitrary l-value expression. Bind it up as a
1016 /// full-expression.
1017 StmtResult Sema::ActOnForEachLValueExpr(Expr *E) {
1018 CheckImplicitConversions(E);
1019 ExprResult Result = MaybeCreateExprWithCleanups(E);
1020 if (Result.isInvalid()) return StmtError();
1021 return Owned(static_cast<Stmt*>(Result.get()));
1025 Sema::ActOnObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) {
1028 // Bail out early if we've got a type-dependent expression.
1029 if (collection->isTypeDependent()) return Owned(collection);
1031 // Perform normal l-value conversion.
1032 ExprResult result = DefaultFunctionArrayLvalueConversion(collection);
1033 if (result.isInvalid())
1035 collection = result.take();
1037 // The operand needs to have object-pointer type.
1038 // TODO: should we do a contextual conversion?
1039 const ObjCObjectPointerType *pointerType =
1040 collection->getType()->getAs<ObjCObjectPointerType>();
1042 return Diag(forLoc, diag::err_collection_expr_type)
1043 << collection->getType() << collection->getSourceRange();
1045 // Check that the operand provides
1046 // - countByEnumeratingWithState:objects:count:
1047 const ObjCObjectType *objectType = pointerType->getObjectType();
1048 ObjCInterfaceDecl *iface = objectType->getInterface();
1050 // If we have a forward-declared type, we can't do this check.
1051 if (iface && iface->isForwardDecl()) {
1052 // This is ill-formed under ARC.
1053 if (getLangOptions().ObjCAutoRefCount) {
1054 Diag(forLoc, diag::err_arc_collection_forward)
1055 << pointerType->getPointeeType() << collection->getSourceRange();
1058 // Otherwise, if we have any useful type information, check that
1059 // the type declares the appropriate method.
1060 } else if (iface || !objectType->qual_empty()) {
1061 IdentifierInfo *selectorIdents[] = {
1062 &Context.Idents.get("countByEnumeratingWithState"),
1063 &Context.Idents.get("objects"),
1064 &Context.Idents.get("count")
1066 Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]);
1068 ObjCMethodDecl *method = 0;
1070 // If there's an interface, look in both the public and private APIs.
1072 method = iface->lookupInstanceMethod(selector);
1073 if (!method) method = LookupPrivateInstanceMethod(selector, iface);
1076 // Also check protocol qualifiers.
1078 method = LookupMethodInQualifiedType(selector, pointerType,
1081 // If we didn't find it anywhere, give up.
1083 Diag(forLoc, diag::warn_collection_expr_type)
1084 << collection->getType() << selector << collection->getSourceRange();
1087 // TODO: check for an incompatible signature?
1090 // Wrap up any cleanups in the expression.
1091 return Owned(MaybeCreateExprWithCleanups(collection));
1095 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
1096 SourceLocation LParenLoc,
1097 Stmt *First, Expr *Second,
1098 SourceLocation RParenLoc, Stmt *Body) {
1101 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
1102 if (!DS->isSingleDecl())
1103 return StmtError(Diag((*DS->decl_begin())->getLocation(),
1104 diag::err_toomany_element_decls));
1106 VarDecl *D = cast<VarDecl>(DS->getSingleDecl());
1107 FirstType = D->getType();
1108 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
1109 // declare identifiers for objects having storage class 'auto' or
1111 if (!D->hasLocalStorage())
1112 return StmtError(Diag(D->getLocation(),
1113 diag::err_non_variable_decl_in_for));
1115 Expr *FirstE = cast<Expr>(First);
1116 if (!FirstE->isTypeDependent() && !FirstE->isLValue())
1117 return StmtError(Diag(First->getLocStart(),
1118 diag::err_selector_element_not_lvalue)
1119 << First->getSourceRange());
1121 FirstType = static_cast<Expr*>(First)->getType();
1123 if (!FirstType->isDependentType() &&
1124 !FirstType->isObjCObjectPointerType() &&
1125 !FirstType->isBlockPointerType())
1126 Diag(ForLoc, diag::err_selector_element_type)
1127 << FirstType << First->getSourceRange();
1130 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body,
1131 ForLoc, RParenLoc));
1136 enum BeginEndFunction {
1141 /// Build a variable declaration for a for-range statement.
1142 static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc,
1143 QualType Type, const char *Name) {
1144 DeclContext *DC = SemaRef.CurContext;
1145 IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
1146 TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
1147 VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type,
1148 TInfo, SC_Auto, SC_None);
1149 Decl->setImplicit();
1153 /// Finish building a variable declaration for a for-range statement.
1154 /// \return true if an error occurs.
1155 static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init,
1156 SourceLocation Loc, int diag) {
1157 // Deduce the type for the iterator variable now rather than leaving it to
1158 // AddInitializerToDecl, so we can produce a more suitable diagnostic.
1159 TypeSourceInfo *InitTSI = 0;
1160 if (Init->getType()->isVoidType() ||
1161 !SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitTSI))
1162 SemaRef.Diag(Loc, diag) << Init->getType();
1164 Decl->setInvalidDecl();
1167 Decl->setTypeSourceInfo(InitTSI);
1168 Decl->setType(InitTSI->getType());
1170 // In ARC, infer lifetime.
1171 // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if
1172 // we're doing the equivalent of fast iteration.
1173 if (SemaRef.getLangOptions().ObjCAutoRefCount &&
1174 SemaRef.inferObjCARCLifetime(Decl))
1175 Decl->setInvalidDecl();
1177 SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false,
1178 /*TypeMayContainAuto=*/false);
1179 SemaRef.FinalizeDeclaration(Decl);
1180 SemaRef.CurContext->addHiddenDecl(Decl);
1184 /// Produce a note indicating which begin/end function was implicitly called
1185 /// by a C++0x for-range statement. This is often not obvious from the code,
1186 /// nor from the diagnostics produced when analysing the implicit expressions
1187 /// required in a for-range statement.
1188 void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E,
1189 BeginEndFunction BEF) {
1190 CallExpr *CE = dyn_cast<CallExpr>(E);
1193 FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
1196 SourceLocation Loc = D->getLocation();
1198 std::string Description;
1199 bool IsTemplate = false;
1200 if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) {
1201 Description = SemaRef.getTemplateArgumentBindingsText(
1202 FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs());
1206 SemaRef.Diag(Loc, diag::note_for_range_begin_end)
1207 << BEF << IsTemplate << Description << E->getType();
1210 /// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the
1211 /// given LookupResult is non-empty, it is assumed to describe a member which
1212 /// will be invoked. Otherwise, the function will be found via argument
1213 /// dependent lookup.
1214 static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S,
1217 BeginEndFunction BEF,
1218 const DeclarationNameInfo &NameInfo,
1219 LookupResult &MemberLookup,
1221 ExprResult CallExpr;
1222 if (!MemberLookup.empty()) {
1223 ExprResult MemberRef =
1224 SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc,
1225 /*IsPtr=*/false, CXXScopeSpec(),
1226 /*Qualifier=*/0, MemberLookup,
1227 /*TemplateArgs=*/0);
1228 if (MemberRef.isInvalid())
1230 CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(),
1232 if (CallExpr.isInvalid())
1235 UnresolvedSet<0> FoundNames;
1236 // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace
1237 // std is an associated namespace.
1238 UnresolvedLookupExpr *Fn =
1239 UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0,
1240 NestedNameSpecifierLoc(), NameInfo,
1241 /*NeedsADL=*/true, /*Overloaded=*/false,
1242 FoundNames.begin(), FoundNames.end(),
1243 /*LookInStdNamespace=*/true);
1244 CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc,
1246 if (CallExpr.isInvalid()) {
1247 SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type)
1248 << Range->getType();
1252 if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc,
1253 diag::err_for_range_iter_deduction_failure)) {
1254 NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF);
1262 /// ActOnCXXForRangeStmt - Check and build a C++0x for-range statement.
1264 /// C++0x [stmt.ranged]:
1265 /// A range-based for statement is equivalent to
1268 /// auto && __range = range-init;
1269 /// for ( auto __begin = begin-expr,
1270 /// __end = end-expr;
1271 /// __begin != __end;
1273 /// for-range-declaration = *__begin;
1278 /// The body of the loop is not available yet, since it cannot be analysed until
1279 /// we have determined the type of the for-range-declaration.
1281 Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
1282 Stmt *First, SourceLocation ColonLoc, Expr *Range,
1283 SourceLocation RParenLoc) {
1284 if (!First || !Range)
1287 DeclStmt *DS = dyn_cast<DeclStmt>(First);
1288 assert(DS && "first part of for range not a decl stmt");
1290 if (!DS->isSingleDecl()) {
1291 Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range);
1294 if (DS->getSingleDecl()->isInvalidDecl())
1297 if (DiagnoseUnexpandedParameterPack(Range, UPPC_Expression))
1300 // Build auto && __range = range-init
1301 SourceLocation RangeLoc = Range->getLocStart();
1302 VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc,
1303 Context.getAutoRRefDeductType(),
1305 if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc,
1306 diag::err_for_range_deduction_failure))
1309 // Claim the type doesn't contain auto: we've already done the checking.
1310 DeclGroupPtrTy RangeGroup =
1311 BuildDeclaratorGroup((Decl**)&RangeVar, 1, /*TypeMayContainAuto=*/false);
1312 StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc);
1313 if (RangeDecl.isInvalid())
1316 return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(),
1317 /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS,
1321 /// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement.
1323 Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc,
1324 Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond,
1325 Expr *Inc, Stmt *LoopVarDecl,
1326 SourceLocation RParenLoc) {
1327 Scope *S = getCurScope();
1329 DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl);
1330 VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl());
1331 QualType RangeVarType = RangeVar->getType();
1333 DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl);
1334 VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl());
1336 StmtResult BeginEndDecl = BeginEnd;
1337 ExprResult NotEqExpr = Cond, IncrExpr = Inc;
1339 if (!BeginEndDecl.get() && !RangeVarType->isDependentType()) {
1340 SourceLocation RangeLoc = RangeVar->getLocation();
1342 const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
1344 ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
1345 VK_LValue, ColonLoc);
1346 if (BeginRangeRef.isInvalid())
1349 ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType,
1350 VK_LValue, ColonLoc);
1351 if (EndRangeRef.isInvalid())
1354 QualType AutoType = Context.getAutoDeductType();
1355 Expr *Range = RangeVar->getInit();
1358 QualType RangeType = Range->getType();
1360 if (RequireCompleteType(RangeLoc, RangeType,
1361 PDiag(diag::err_for_range_incomplete_type)))
1364 // Build auto __begin = begin-expr, __end = end-expr.
1365 VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
1367 VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType,
1370 // Build begin-expr and end-expr and attach to __begin and __end variables.
1371 ExprResult BeginExpr, EndExpr;
1372 if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) {
1373 // - if _RangeT is an array type, begin-expr and end-expr are __range and
1374 // __range + __bound, respectively, where __bound is the array bound. If
1375 // _RangeT is an array of unknown size or an array of incomplete type,
1376 // the program is ill-formed;
1378 // begin-expr is __range.
1379 BeginExpr = BeginRangeRef;
1380 if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc,
1381 diag::err_for_range_iter_deduction_failure)) {
1382 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1386 // Find the array bound.
1387 ExprResult BoundExpr;
1388 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT))
1389 BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(),
1390 Context.getPointerDiffType(),
1392 else if (const VariableArrayType *VAT =
1393 dyn_cast<VariableArrayType>(UnqAT))
1394 BoundExpr = VAT->getSizeExpr();
1396 // Can't be a DependentSizedArrayType or an IncompleteArrayType since
1397 // UnqAT is not incomplete and Range is not type-dependent.
1398 llvm_unreachable("Unexpected array type in for-range");
1401 // end-expr is __range + __bound.
1402 EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(),
1404 if (EndExpr.isInvalid())
1406 if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc,
1407 diag::err_for_range_iter_deduction_failure)) {
1408 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
1412 DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"),
1414 DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"),
1417 LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName);
1418 LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName);
1420 if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) {
1421 // - if _RangeT is a class type, the unqualified-ids begin and end are
1422 // looked up in the scope of class _RangeT as if by class member access
1423 // lookup (3.4.5), and if either (or both) finds at least one
1424 // declaration, begin-expr and end-expr are __range.begin() and
1425 // __range.end(), respectively;
1426 LookupQualifiedName(BeginMemberLookup, D);
1427 LookupQualifiedName(EndMemberLookup, D);
1429 if (BeginMemberLookup.empty() != EndMemberLookup.empty()) {
1430 Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch)
1431 << RangeType << BeginMemberLookup.empty();
1435 // - otherwise, begin-expr and end-expr are begin(__range) and
1436 // end(__range), respectively, where begin and end are looked up with
1437 // argument-dependent lookup (3.4.2). For the purposes of this name
1438 // lookup, namespace std is an associated namespace.
1441 BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar,
1442 BEF_begin, BeginNameInfo,
1444 BeginRangeRef.get());
1445 if (BeginExpr.isInvalid())
1448 EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar,
1449 BEF_end, EndNameInfo,
1450 EndMemberLookup, EndRangeRef.get());
1451 if (EndExpr.isInvalid())
1455 // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same.
1456 QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
1457 if (!Context.hasSameType(BeginType, EndType)) {
1458 Diag(RangeLoc, diag::err_for_range_begin_end_types_differ)
1459 << BeginType << EndType;
1460 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1461 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
1464 Decl *BeginEndDecls[] = { BeginVar, EndVar };
1465 // Claim the type doesn't contain auto: we've already done the checking.
1466 DeclGroupPtrTy BeginEndGroup =
1467 BuildDeclaratorGroup(BeginEndDecls, 2, /*TypeMayContainAuto=*/false);
1468 BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc);
1470 const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
1471 ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
1472 VK_LValue, ColonLoc);
1473 if (BeginRef.isInvalid())
1476 ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(),
1477 VK_LValue, ColonLoc);
1478 if (EndRef.isInvalid())
1481 // Build and check __begin != __end expression.
1482 NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal,
1483 BeginRef.get(), EndRef.get());
1484 NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get());
1485 NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get());
1486 if (NotEqExpr.isInvalid()) {
1487 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1488 if (!Context.hasSameType(BeginType, EndType))
1489 NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
1493 // Build and check ++__begin expression.
1494 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
1495 VK_LValue, ColonLoc);
1496 if (BeginRef.isInvalid())
1499 IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get());
1500 IncrExpr = ActOnFinishFullExpr(IncrExpr.get());
1501 if (IncrExpr.isInvalid()) {
1502 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1506 // Build and check *__begin expression.
1507 BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
1508 VK_LValue, ColonLoc);
1509 if (BeginRef.isInvalid())
1512 ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get());
1513 if (DerefExpr.isInvalid()) {
1514 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1518 // Attach *__begin as initializer for VD.
1519 if (!LoopVar->isInvalidDecl()) {
1520 AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false,
1521 /*TypeMayContainAuto=*/true);
1522 if (LoopVar->isInvalidDecl())
1523 NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
1526 // The range is implicitly used as a placeholder when it is dependent.
1527 RangeVar->setUsed();
1530 return Owned(new (Context) CXXForRangeStmt(RangeDS,
1531 cast_or_null<DeclStmt>(BeginEndDecl.get()),
1532 NotEqExpr.take(), IncrExpr.take(),
1533 LoopVarDS, /*Body=*/0, ForLoc,
1534 ColonLoc, RParenLoc));
1537 /// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement.
1538 /// This is a separate step from ActOnCXXForRangeStmt because analysis of the
1539 /// body cannot be performed until after the type of the range variable is
1541 StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) {
1545 cast<CXXForRangeStmt>(S)->setBody(B);
1549 StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc,
1550 SourceLocation LabelLoc,
1551 LabelDecl *TheDecl) {
1552 getCurFunction()->setHasBranchIntoScope();
1554 return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc));
1558 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
1560 // Convert operand to void*
1561 if (!E->isTypeDependent()) {
1562 QualType ETy = E->getType();
1563 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
1564 ExprResult ExprRes = Owned(E);
1565 AssignConvertType ConvTy =
1566 CheckSingleAssignmentConstraints(DestTy, ExprRes);
1567 if (ExprRes.isInvalid())
1570 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
1574 getCurFunction()->setHasIndirectGoto();
1576 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E));
1580 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
1581 Scope *S = CurScope->getContinueParent();
1583 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
1584 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
1587 return Owned(new (Context) ContinueStmt(ContinueLoc));
1591 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
1592 Scope *S = CurScope->getBreakParent();
1594 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
1595 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
1598 return Owned(new (Context) BreakStmt(BreakLoc));
1601 /// \brief Determine whether the given expression is a candidate for
1602 /// copy elision in either a return statement or a throw expression.
1604 /// \param ReturnType If we're determining the copy elision candidate for
1605 /// a return statement, this is the return type of the function. If we're
1606 /// determining the copy elision candidate for a throw expression, this will
1609 /// \param E The expression being returned from the function or block, or
1612 /// \param AllowFunctionParameter Whether we allow function parameters to
1613 /// be considered NRVO candidates. C++ prohibits this for NRVO itself, but
1614 /// we re-use this logic to determine whether we should try to move as part of
1615 /// a return or throw (which does allow function parameters).
1617 /// \returns The NRVO candidate variable, if the return statement may use the
1618 /// NRVO, or NULL if there is no such candidate.
1619 const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType,
1621 bool AllowFunctionParameter) {
1622 QualType ExprType = E->getType();
1623 // - in a return statement in a function with ...
1624 // ... a class return type ...
1625 if (!ReturnType.isNull()) {
1626 if (!ReturnType->isRecordType())
1628 // ... the same cv-unqualified type as the function return type ...
1629 if (!Context.hasSameUnqualifiedType(ReturnType, ExprType))
1633 // ... the expression is the name of a non-volatile automatic object
1634 // (other than a function or catch-clause parameter)) ...
1635 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
1638 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
1642 if (VD->hasLocalStorage() && !VD->isExceptionVariable() &&
1643 !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() &&
1644 !VD->getType().isVolatileQualified() &&
1645 ((VD->getKind() == Decl::Var) ||
1646 (AllowFunctionParameter && VD->getKind() == Decl::ParmVar)))
1652 /// \brief Perform the initialization of a potentially-movable value, which
1653 /// is the result of return value.
1655 /// This routine implements C++0x [class.copy]p33, which attempts to treat
1656 /// returned lvalues as rvalues in certain cases (to prefer move construction),
1657 /// then falls back to treating them as lvalues if that failed.
1659 Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
1660 const VarDecl *NRVOCandidate,
1661 QualType ResultType,
1664 // C++0x [class.copy]p33:
1665 // When the criteria for elision of a copy operation are met or would
1666 // be met save for the fact that the source object is a function
1667 // parameter, and the object to be copied is designated by an lvalue,
1668 // overload resolution to select the constructor for the copy is first
1669 // performed as if the object were designated by an rvalue.
1670 ExprResult Res = ExprError();
1672 (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) {
1673 ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack,
1674 Value->getType(), CK_LValueToRValue,
1677 Expr *InitExpr = &AsRvalue;
1678 InitializationKind Kind
1679 = InitializationKind::CreateCopy(Value->getLocStart(),
1680 Value->getLocStart());
1681 InitializationSequence Seq(*this, Entity, Kind, &InitExpr, 1);
1683 // [...] If overload resolution fails, or if the type of the first
1684 // parameter of the selected constructor is not an rvalue reference
1685 // to the object's type (possibly cv-qualified), overload resolution
1686 // is performed again, considering the object as an lvalue.
1688 for (InitializationSequence::step_iterator Step = Seq.step_begin(),
1689 StepEnd = Seq.step_end();
1690 Step != StepEnd; ++Step) {
1691 if (Step->Kind != InitializationSequence::SK_ConstructorInitialization)
1694 CXXConstructorDecl *Constructor
1695 = cast<CXXConstructorDecl>(Step->Function.Function);
1697 const RValueReferenceType *RRefType
1698 = Constructor->getParamDecl(0)->getType()
1699 ->getAs<RValueReferenceType>();
1701 // If we don't meet the criteria, break out now.
1703 !Context.hasSameUnqualifiedType(RRefType->getPointeeType(),
1704 Context.getTypeDeclType(Constructor->getParent())))
1707 // Promote "AsRvalue" to the heap, since we now need this
1708 // expression node to persist.
1709 Value = ImplicitCastExpr::Create(Context, Value->getType(),
1710 CK_LValueToRValue, Value, 0,
1713 // Complete type-checking the initialization of the return type
1714 // using the constructor we found.
1715 Res = Seq.Perform(*this, Entity, Kind, MultiExprArg(&Value, 1));
1720 // Either we didn't meet the criteria for treating an lvalue as an rvalue,
1721 // above, or overload resolution failed. Either way, we need to try
1722 // (again) now with the return value expression as written.
1723 if (Res.isInvalid())
1724 Res = PerformCopyInitialization(Entity, SourceLocation(), Value);
1729 /// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
1732 Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
1733 // If this is the first return we've seen in the block, infer the type of
1734 // the block from it.
1735 BlockScopeInfo *CurBlock = getCurBlock();
1736 if (CurBlock->ReturnType.isNull()) {
1738 // Don't call UsualUnaryConversions(), since we don't want to do
1739 // integer promotions here.
1740 ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
1741 if (Result.isInvalid())
1743 RetValExp = Result.take();
1745 if (!RetValExp->isTypeDependent()) {
1746 CurBlock->ReturnType = RetValExp->getType();
1747 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) {
1748 // We have to remove a 'const' added to copied-in variable which was
1749 // part of the implementation spec. and not the actual qualifier for
1751 if (CDRE->isConstQualAdded())
1752 CurBlock->ReturnType.removeLocalConst(); // FIXME: local???
1755 CurBlock->ReturnType = Context.DependentTy;
1757 CurBlock->ReturnType = Context.VoidTy;
1759 QualType FnRetType = CurBlock->ReturnType;
1761 if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) {
1762 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr)
1763 << getCurFunctionOrMethodDecl()->getDeclName();
1767 // Otherwise, verify that this result type matches the previous one. We are
1768 // pickier with blocks than for normal functions because we don't have GCC
1769 // compatibility to worry about here.
1770 const VarDecl *NRVOCandidate = 0;
1771 if (FnRetType->isDependentType()) {
1772 // Delay processing for now. TODO: there are lots of dependent
1773 // types we can conclusively prove aren't void.
1774 } else if (FnRetType->isVoidType()) {
1776 !(getLangOptions().CPlusPlus &&
1777 (RetValExp->isTypeDependent() ||
1778 RetValExp->getType()->isVoidType()))) {
1779 Diag(ReturnLoc, diag::err_return_block_has_expr);
1782 } else if (!RetValExp) {
1783 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
1784 } else if (!RetValExp->isTypeDependent()) {
1785 // we have a non-void block with an expression, continue checking
1787 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
1788 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
1791 // In C++ the return statement is handled via a copy initialization.
1792 // the C version of which boils down to CheckSingleAssignmentConstraints.
1793 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false);
1794 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
1796 NRVOCandidate != 0);
1797 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
1798 FnRetType, RetValExp);
1799 if (Res.isInvalid()) {
1800 // FIXME: Cleanup temporaries here, anyway?
1803 RetValExp = Res.take();
1804 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
1808 CheckImplicitConversions(RetValExp, ReturnLoc);
1809 RetValExp = MaybeCreateExprWithCleanups(RetValExp);
1811 ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp,
1814 // If we need to check for the named return value optimization, save the
1815 // return statement in our scope for later processing.
1816 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() &&
1817 !CurContext->isDependentContext())
1818 FunctionScopes.back()->Returns.push_back(Result);
1820 return Owned(Result);
1824 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
1825 // Check for unexpanded parameter packs.
1826 if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
1830 return ActOnBlockReturnStmt(ReturnLoc, RetValExp);
1833 QualType DeclaredRetType;
1834 if (const FunctionDecl *FD = getCurFunctionDecl()) {
1835 FnRetType = FD->getResultType();
1836 DeclaredRetType = FnRetType;
1837 if (FD->hasAttr<NoReturnAttr>() ||
1838 FD->getType()->getAs<FunctionType>()->getNoReturnAttr())
1839 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
1840 << getCurFunctionOrMethodDecl()->getDeclName();
1841 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) {
1842 DeclaredRetType = MD->getResultType();
1843 if (MD->hasRelatedResultType() && MD->getClassInterface()) {
1844 // In the implementation of a method with a related return type, the
1845 // type used to type-check the validity of return statements within the
1846 // method body is a pointer to the type of the class being implemented.
1847 FnRetType = Context.getObjCInterfaceType(MD->getClassInterface());
1848 FnRetType = Context.getObjCObjectPointerType(FnRetType);
1850 FnRetType = DeclaredRetType;
1852 } else // If we don't have a function/method context, bail.
1855 ReturnStmt *Result = 0;
1856 if (FnRetType->isVoidType()) {
1858 if (!RetValExp->isTypeDependent()) {
1859 // C99 6.8.6.4p1 (ext_ since GCC warns)
1860 unsigned D = diag::ext_return_has_expr;
1861 if (RetValExp->getType()->isVoidType())
1862 D = diag::ext_return_has_void_expr;
1864 ExprResult Result = Owned(RetValExp);
1865 Result = IgnoredValueConversions(Result.take());
1866 if (Result.isInvalid())
1868 RetValExp = Result.take();
1869 RetValExp = ImpCastExprToType(RetValExp,
1870 Context.VoidTy, CK_ToVoid).take();
1873 // return (some void expression); is legal in C++.
1874 if (D != diag::ext_return_has_void_expr ||
1875 !getLangOptions().CPlusPlus) {
1876 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
1878 int FunctionKind = 0;
1879 if (isa<ObjCMethodDecl>(CurDecl))
1881 else if (isa<CXXConstructorDecl>(CurDecl))
1883 else if (isa<CXXDestructorDecl>(CurDecl))
1887 << CurDecl->getDeclName() << FunctionKind
1888 << RetValExp->getSourceRange();
1892 CheckImplicitConversions(RetValExp, ReturnLoc);
1893 RetValExp = MaybeCreateExprWithCleanups(RetValExp);
1896 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0);
1897 } else if (!RetValExp && !FnRetType->isDependentType()) {
1898 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4
1899 // C99 6.8.6.4p1 (ext_ since GCC warns)
1900 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr;
1902 if (FunctionDecl *FD = getCurFunctionDecl())
1903 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
1905 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
1906 Result = new (Context) ReturnStmt(ReturnLoc);
1908 const VarDecl *NRVOCandidate = 0;
1909 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
1910 // we have a non-void function with an expression, continue checking
1912 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
1913 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
1916 // In C++ the return statement is handled via a copy initialization,
1917 // the C version of which boils down to CheckSingleAssignmentConstraints.
1918 NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false);
1919 InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc,
1921 NRVOCandidate != 0);
1922 ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate,
1923 FnRetType, RetValExp);
1924 if (Res.isInvalid()) {
1925 // FIXME: Cleanup temporaries here, anyway?
1929 RetValExp = Res.takeAs<Expr>();
1931 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
1935 // If we type-checked an Objective-C method's return type based
1936 // on a related return type, we may need to adjust the return
1937 // type again. Do so now.
1938 if (DeclaredRetType != FnRetType) {
1939 ExprResult result = PerformImplicitConversion(RetValExp,
1942 if (result.isInvalid()) return StmtError();
1943 RetValExp = result.take();
1946 CheckImplicitConversions(RetValExp, ReturnLoc);
1947 RetValExp = MaybeCreateExprWithCleanups(RetValExp);
1949 Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate);
1952 // If we need to check for the named return value optimization, save the
1953 // return statement in our scope for later processing.
1954 if (getLangOptions().CPlusPlus && FnRetType->isRecordType() &&
1955 !CurContext->isDependentContext())
1956 FunctionScopes.back()->Returns.push_back(Result);
1958 return Owned(Result);
1961 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
1962 /// ignore "noop" casts in places where an lvalue is required by an inline asm.
1963 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but
1964 /// provide a strong guidance to not use it.
1966 /// This method checks to see if the argument is an acceptable l-value and
1967 /// returns false if it is a case we can handle.
1968 static bool CheckAsmLValue(const Expr *E, Sema &S) {
1969 // Type dependent expressions will be checked during instantiation.
1970 if (E->isTypeDependent())
1974 return false; // Cool, this is an lvalue.
1976 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we
1977 // are supposed to allow.
1978 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
1979 if (E != E2 && E2->isLValue()) {
1980 if (!S.getLangOptions().HeinousExtensions)
1981 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue)
1982 << E->getSourceRange();
1984 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
1985 << E->getSourceRange();
1986 // Accept, even if we emitted an error diagnostic.
1990 // None of the above, just randomly invalid non-lvalue.
1994 /// isOperandMentioned - Return true if the specified operand # is mentioned
1995 /// anywhere in the decomposed asm string.
1996 static bool isOperandMentioned(unsigned OpNo,
1997 ArrayRef<AsmStmt::AsmStringPiece> AsmStrPieces) {
1998 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) {
1999 const AsmStmt::AsmStringPiece &Piece = AsmStrPieces[p];
2000 if (!Piece.isOperand()) continue;
2002 // If this is a reference to the input and if the input was the smaller
2003 // one, then we have to reject this asm.
2004 if (Piece.getOperandNo() == OpNo)
2011 StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, bool IsSimple,
2012 bool IsVolatile, unsigned NumOutputs,
2013 unsigned NumInputs, IdentifierInfo **Names,
2014 MultiExprArg constraints, MultiExprArg exprs,
2015 Expr *asmString, MultiExprArg clobbers,
2016 SourceLocation RParenLoc, bool MSAsm) {
2017 unsigned NumClobbers = clobbers.size();
2018 StringLiteral **Constraints =
2019 reinterpret_cast<StringLiteral**>(constraints.get());
2020 Expr **Exprs = exprs.get();
2021 StringLiteral *AsmString = cast<StringLiteral>(asmString);
2022 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get());
2024 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
2026 // The parser verifies that there is a string literal here.
2027 if (!AsmString->isAscii())
2028 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character)
2029 << AsmString->getSourceRange());
2031 for (unsigned i = 0; i != NumOutputs; i++) {
2032 StringLiteral *Literal = Constraints[i];
2033 if (!Literal->isAscii())
2034 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
2035 << Literal->getSourceRange());
2037 StringRef OutputName;
2039 OutputName = Names[i]->getName();
2041 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName);
2042 if (!Context.getTargetInfo().validateOutputConstraint(Info))
2043 return StmtError(Diag(Literal->getLocStart(),
2044 diag::err_asm_invalid_output_constraint)
2045 << Info.getConstraintStr());
2047 // Check that the output exprs are valid lvalues.
2048 Expr *OutputExpr = Exprs[i];
2049 if (CheckAsmLValue(OutputExpr, *this)) {
2050 return StmtError(Diag(OutputExpr->getLocStart(),
2051 diag::err_asm_invalid_lvalue_in_output)
2052 << OutputExpr->getSourceRange());
2055 OutputConstraintInfos.push_back(Info);
2058 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
2060 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
2061 StringLiteral *Literal = Constraints[i];
2062 if (!Literal->isAscii())
2063 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
2064 << Literal->getSourceRange());
2066 StringRef InputName;
2068 InputName = Names[i]->getName();
2070 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName);
2071 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(),
2072 NumOutputs, Info)) {
2073 return StmtError(Diag(Literal->getLocStart(),
2074 diag::err_asm_invalid_input_constraint)
2075 << Info.getConstraintStr());
2078 Expr *InputExpr = Exprs[i];
2080 // Only allow void types for memory constraints.
2081 if (Info.allowsMemory() && !Info.allowsRegister()) {
2082 if (CheckAsmLValue(InputExpr, *this))
2083 return StmtError(Diag(InputExpr->getLocStart(),
2084 diag::err_asm_invalid_lvalue_in_input)
2085 << Info.getConstraintStr()
2086 << InputExpr->getSourceRange());
2089 if (Info.allowsRegister()) {
2090 if (InputExpr->getType()->isVoidType()) {
2091 return StmtError(Diag(InputExpr->getLocStart(),
2092 diag::err_asm_invalid_type_in_input)
2093 << InputExpr->getType() << Info.getConstraintStr()
2094 << InputExpr->getSourceRange());
2098 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
2099 if (Result.isInvalid())
2102 Exprs[i] = Result.take();
2103 InputConstraintInfos.push_back(Info);
2106 // Check that the clobbers are valid.
2107 for (unsigned i = 0; i != NumClobbers; i++) {
2108 StringLiteral *Literal = Clobbers[i];
2109 if (!Literal->isAscii())
2110 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
2111 << Literal->getSourceRange());
2113 StringRef Clobber = Literal->getString();
2115 if (!Context.getTargetInfo().isValidClobber(Clobber))
2116 return StmtError(Diag(Literal->getLocStart(),
2117 diag::err_asm_unknown_register_name) << Clobber);
2121 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm,
2122 NumOutputs, NumInputs, Names, Constraints, Exprs,
2123 AsmString, NumClobbers, Clobbers, RParenLoc);
2124 // Validate the asm string, ensuring it makes sense given the operands we
2126 SmallVector<AsmStmt::AsmStringPiece, 8> Pieces;
2128 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
2129 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
2130 << AsmString->getSourceRange();
2134 // Validate tied input operands for type mismatches.
2135 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
2136 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
2138 // If this is a tied constraint, verify that the output and input have
2139 // either exactly the same type, or that they are int/ptr operands with the
2140 // same size (int/long, int*/long, are ok etc).
2141 if (!Info.hasTiedOperand()) continue;
2143 unsigned TiedTo = Info.getTiedOperand();
2144 unsigned InputOpNo = i+NumOutputs;
2145 Expr *OutputExpr = Exprs[TiedTo];
2146 Expr *InputExpr = Exprs[InputOpNo];
2148 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent())
2151 QualType InTy = InputExpr->getType();
2152 QualType OutTy = OutputExpr->getType();
2153 if (Context.hasSameType(InTy, OutTy))
2154 continue; // All types can be tied to themselves.
2156 // Decide if the input and output are in the same domain (integer/ptr or
2159 AD_Int, AD_FP, AD_Other
2160 } InputDomain, OutputDomain;
2162 if (InTy->isIntegerType() || InTy->isPointerType())
2163 InputDomain = AD_Int;
2164 else if (InTy->isRealFloatingType())
2165 InputDomain = AD_FP;
2167 InputDomain = AD_Other;
2169 if (OutTy->isIntegerType() || OutTy->isPointerType())
2170 OutputDomain = AD_Int;
2171 else if (OutTy->isRealFloatingType())
2172 OutputDomain = AD_FP;
2174 OutputDomain = AD_Other;
2176 // They are ok if they are the same size and in the same domain. This
2177 // allows tying things like:
2179 // void* to int if they are the same size.
2180 // double to long double if they are the same size.
2182 uint64_t OutSize = Context.getTypeSize(OutTy);
2183 uint64_t InSize = Context.getTypeSize(InTy);
2184 if (OutSize == InSize && InputDomain == OutputDomain &&
2185 InputDomain != AD_Other)
2188 // If the smaller input/output operand is not mentioned in the asm string,
2189 // then we can promote the smaller one to a larger input and the asm string
2191 bool SmallerValueMentioned = false;
2193 // If this is a reference to the input and if the input was the smaller
2194 // one, then we have to reject this asm.
2195 if (isOperandMentioned(InputOpNo, Pieces)) {
2196 // This is a use in the asm string of the smaller operand. Since we
2197 // codegen this by promoting to a wider value, the asm will get printed
2199 SmallerValueMentioned |= InSize < OutSize;
2201 if (isOperandMentioned(TiedTo, Pieces)) {
2202 // If this is a reference to the output, and if the output is the larger
2203 // value, then it's ok because we'll promote the input to the larger type.
2204 SmallerValueMentioned |= OutSize < InSize;
2207 // If the smaller value wasn't mentioned in the asm string, and if the
2208 // output was a register, just extend the shorter one to the size of the
2210 if (!SmallerValueMentioned && InputDomain != AD_Other &&
2211 OutputConstraintInfos[TiedTo].allowsRegister())
2214 // Either both of the operands were mentioned or the smaller one was
2215 // mentioned. One more special case that we'll allow: if the tied input is
2216 // integer, unmentioned, and is a constant, then we'll allow truncating it
2217 // down to the size of the destination.
2218 if (InputDomain == AD_Int && OutputDomain == AD_Int &&
2219 !isOperandMentioned(InputOpNo, Pieces) &&
2220 InputExpr->isEvaluatable(Context)) {
2222 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast);
2223 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take();
2224 Exprs[InputOpNo] = InputExpr;
2225 NS->setInputExpr(i, InputExpr);
2229 Diag(InputExpr->getLocStart(),
2230 diag::err_asm_tying_incompatible_types)
2231 << InTy << OutTy << OutputExpr->getSourceRange()
2232 << InputExpr->getSourceRange();
2240 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
2241 SourceLocation RParen, Decl *Parm,
2243 VarDecl *Var = cast_or_null<VarDecl>(Parm);
2244 if (Var && Var->isInvalidDecl())
2247 return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body));
2251 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) {
2252 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body));
2256 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
2257 MultiStmtArg CatchStmts, Stmt *Finally) {
2258 if (!getLangOptions().ObjCExceptions)
2259 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try";
2261 getCurFunction()->setHasBranchProtectedScope();
2262 unsigned NumCatchStmts = CatchStmts.size();
2263 return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try,
2264 CatchStmts.release(),
2269 StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc,
2272 Throw = MaybeCreateExprWithCleanups(Throw);
2273 ExprResult Result = DefaultLvalueConversion(Throw);
2274 if (Result.isInvalid())
2277 Throw = Result.take();
2278 QualType ThrowType = Throw->getType();
2279 // Make sure the expression type is an ObjC pointer or "void *".
2280 if (!ThrowType->isDependentType() &&
2281 !ThrowType->isObjCObjectPointerType()) {
2282 const PointerType *PT = ThrowType->getAs<PointerType>();
2283 if (!PT || !PT->getPointeeType()->isVoidType())
2284 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object)
2285 << Throw->getType() << Throw->getSourceRange());
2289 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw));
2293 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
2295 if (!getLangOptions().ObjCExceptions)
2296 Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw";
2299 // @throw without an expression designates a rethrow (which much occur
2300 // in the context of an @catch clause).
2301 Scope *AtCatchParent = CurScope;
2302 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
2303 AtCatchParent = AtCatchParent->getParent();
2305 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch));
2308 return BuildObjCAtThrowStmt(AtLoc, Throw);
2312 Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) {
2313 ExprResult result = DefaultLvalueConversion(operand);
2314 if (result.isInvalid())
2316 operand = result.take();
2318 // Make sure the expression type is an ObjC pointer or "void *".
2319 QualType type = operand->getType();
2320 if (!type->isDependentType() &&
2321 !type->isObjCObjectPointerType()) {
2322 const PointerType *pointerType = type->getAs<PointerType>();
2323 if (!pointerType || !pointerType->getPointeeType()->isVoidType())
2324 return Diag(atLoc, diag::error_objc_synchronized_expects_object)
2325 << type << operand->getSourceRange();
2328 // The operand to @synchronized is a full-expression.
2329 return MaybeCreateExprWithCleanups(operand);
2333 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr,
2335 // We can't jump into or indirect-jump out of a @synchronized block.
2336 getCurFunction()->setHasBranchProtectedScope();
2337 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody));
2340 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
2341 /// and creates a proper catch handler from them.
2343 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl,
2344 Stmt *HandlerBlock) {
2345 // There's nothing to test that ActOnExceptionDecl didn't already test.
2346 return Owned(new (Context) CXXCatchStmt(CatchLoc,
2347 cast_or_null<VarDecl>(ExDecl),
2352 Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) {
2353 getCurFunction()->setHasBranchProtectedScope();
2354 return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body));
2359 class TypeWithHandler {
2363 TypeWithHandler(const QualType &type, CXXCatchStmt *statement)
2364 : t(type), stmt(statement) {}
2366 // An arbitrary order is fine as long as it places identical
2367 // types next to each other.
2368 bool operator<(const TypeWithHandler &y) const {
2369 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr())
2371 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr())
2374 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc();
2377 bool operator==(const TypeWithHandler& other) const {
2378 return t == other.t;
2381 CXXCatchStmt *getCatchStmt() const { return stmt; }
2382 SourceLocation getTypeSpecStartLoc() const {
2383 return stmt->getExceptionDecl()->getTypeSpecStartLoc();
2389 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of
2390 /// handlers and creates a try statement from them.
2392 Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
2393 MultiStmtArg RawHandlers) {
2394 // Don't report an error if 'try' is used in system headers.
2395 if (!getLangOptions().CXXExceptions &&
2396 !getSourceManager().isInSystemHeader(TryLoc))
2397 Diag(TryLoc, diag::err_exceptions_disabled) << "try";
2399 unsigned NumHandlers = RawHandlers.size();
2400 assert(NumHandlers > 0 &&
2401 "The parser shouldn't call this if there are no handlers.");
2402 Stmt **Handlers = RawHandlers.get();
2404 SmallVector<TypeWithHandler, 8> TypesWithHandlers;
2406 for (unsigned i = 0; i < NumHandlers; ++i) {
2407 CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]);
2408 if (!Handler->getExceptionDecl()) {
2409 if (i < NumHandlers - 1)
2410 return StmtError(Diag(Handler->getLocStart(),
2411 diag::err_early_catch_all));
2416 const QualType CaughtType = Handler->getCaughtType();
2417 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType);
2418 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler));
2421 // Detect handlers for the same type as an earlier one.
2422 if (NumHandlers > 1) {
2423 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end());
2425 TypeWithHandler prev = TypesWithHandlers[0];
2426 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) {
2427 TypeWithHandler curr = TypesWithHandlers[i];
2430 Diag(curr.getTypeSpecStartLoc(),
2431 diag::warn_exception_caught_by_earlier_handler)
2432 << curr.getCatchStmt()->getCaughtType().getAsString();
2433 Diag(prev.getTypeSpecStartLoc(),
2434 diag::note_previous_exception_handler)
2435 << prev.getCatchStmt()->getCaughtType().getAsString();
2442 getCurFunction()->setHasBranchProtectedScope();
2444 // FIXME: We should detect handlers that cannot catch anything because an
2445 // earlier handler catches a superclass. Need to find a method that is not
2446 // quadratic for this.
2447 // Neither of these are explicitly forbidden, but every compiler detects them
2450 return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock,
2451 Handlers, NumHandlers));
2455 Sema::ActOnSEHTryBlock(bool IsCXXTry,
2456 SourceLocation TryLoc,
2459 assert(TryBlock && Handler);
2461 getCurFunction()->setHasBranchProtectedScope();
2463 return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler));
2467 Sema::ActOnSEHExceptBlock(SourceLocation Loc,
2470 assert(FilterExpr && Block);
2472 if(!FilterExpr->getType()->isIntegerType()) {
2473 return StmtError(Diag(FilterExpr->getExprLoc(),
2474 diag::err_filter_expression_integral)
2475 << FilterExpr->getType());
2478 return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block));
2482 Sema::ActOnSEHFinallyBlock(SourceLocation Loc,
2485 return Owned(SEHFinallyStmt::Create(Context,Loc,Block));