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 //===----------------------------------------------------------------------===//
16 #include "clang/AST/APValue.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/StmtObjC.h"
22 #include "clang/AST/StmtCXX.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/ADT/SmallVector.h"
27 using namespace clang;
29 Sema::OwningStmtResult Sema::ActOnExprStmt(FullExprArg expr) {
30 Expr *E = expr->takeAs<Expr>();
31 assert(E && "ActOnExprStmt(): missing expression");
32 if (E->getType()->isObjCInterfaceType()) {
33 if (LangOpts.ObjCNonFragileABI)
34 Diag(E->getLocEnd(), diag::err_indirection_requires_nonfragile_object)
37 Diag(E->getLocEnd(), diag::err_direct_interface_unsupported)
41 // C99 6.8.3p2: The expression in an expression statement is evaluated as a
42 // void expression for its side effects. Conversion to void allows any
43 // operand, even incomplete types.
45 // Same thing in for stmt first clause (when expr) and third clause.
46 return Owned(static_cast<Stmt*>(E));
50 Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) {
51 return Owned(new (Context) NullStmt(SemiLoc));
54 Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg,
55 SourceLocation StartLoc,
56 SourceLocation EndLoc) {
57 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
59 // If we have an invalid decl, just return an error.
60 if (DG.isNull()) return StmtError();
62 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
65 void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) {
66 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>();
68 // If we have an invalid decl, just return.
69 if (DG.isNull() || !DG.isSingleDecl()) return;
70 // suppress any potential 'unused variable' warning.
71 DG.getSingleDecl()->setUsed();
74 void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
75 const Expr *E = dyn_cast_or_null<Expr>(S);
81 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context))
84 // Okay, we have an unused result. Depending on what the base expression is,
85 // we might want to make a more specific diagnostic. Check for one of these
87 unsigned DiagID = diag::warn_unused_expr;
88 E = E->IgnoreParens();
89 if (isa<ObjCImplicitSetterGetterRefExpr>(E))
90 DiagID = diag::warn_unused_property_expr;
92 if (const CXXExprWithTemporaries *Temps = dyn_cast<CXXExprWithTemporaries>(E))
93 E = Temps->getSubExpr();
94 if (const CXXZeroInitValueExpr *Zero = dyn_cast<CXXZeroInitValueExpr>(E)) {
95 if (const RecordType *RecordT = Zero->getType()->getAs<RecordType>())
96 if (CXXRecordDecl *RecordD = dyn_cast<CXXRecordDecl>(RecordT->getDecl()))
97 if (!RecordD->hasTrivialDestructor())
101 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
102 if (E->getType()->isVoidType())
105 // If the callee has attribute pure, const, or warn_unused_result, warn with
106 // a more specific message to make it clear what is happening.
107 if (const Decl *FD = CE->getCalleeDecl()) {
108 if (FD->getAttr<WarnUnusedResultAttr>()) {
109 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
112 if (FD->getAttr<PureAttr>()) {
113 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
116 if (FD->getAttr<ConstAttr>()) {
117 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
122 else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
123 const ObjCMethodDecl *MD = ME->getMethodDecl();
124 if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
125 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
129 Diag(Loc, DiagID) << R1 << R2;
132 Action::OwningStmtResult
133 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
134 MultiStmtArg elts, bool isStmtExpr) {
135 unsigned NumElts = elts.size();
136 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release());
137 // If we're in C89 mode, check that we don't have any decls after stmts. If
138 // so, emit an extension diagnostic.
139 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) {
140 // Note that __extension__ can be around a decl.
142 // Skip over all declarations.
143 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
146 // We found the end of the list or a statement. Scan for another declstmt.
147 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
151 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
152 Diag(D->getLocation(), diag::ext_mixed_decls_code);
155 // Warn about unused expressions in statements.
156 for (unsigned i = 0; i != NumElts; ++i) {
157 // Ignore statements that are last in a statement expression.
158 if (isStmtExpr && i == NumElts - 1)
161 DiagnoseUnusedExprResult(Elts[i]);
164 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
167 Action::OwningStmtResult
168 Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval,
169 SourceLocation DotDotDotLoc, ExprArg rhsval,
170 SourceLocation ColonLoc) {
171 assert((lhsval.get() != 0) && "missing expression in case statement");
173 // C99 6.8.4.2p3: The expression shall be an integer constant.
174 // However, GCC allows any evaluatable integer expression.
175 Expr *LHSVal = static_cast<Expr*>(lhsval.get());
176 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() &&
177 VerifyIntegerConstantExpression(LHSVal))
180 // GCC extension: The expression shall be an integer constant.
182 Expr *RHSVal = static_cast<Expr*>(rhsval.get());
183 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() &&
184 VerifyIntegerConstantExpression(RHSVal)) {
185 RHSVal = 0; // Recover by just forgetting about it.
189 if (getSwitchStack().empty()) {
190 Diag(CaseLoc, diag::err_case_not_in_switch);
194 // Only now release the smart pointers.
197 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
199 getSwitchStack().back()->addSwitchCase(CS);
203 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
204 void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) {
205 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt);
206 Stmt *SubStmt = subStmt.takeAs<Stmt>();
207 CS->setSubStmt(SubStmt);
210 Action::OwningStmtResult
211 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
212 StmtArg subStmt, Scope *CurScope) {
213 Stmt *SubStmt = subStmt.takeAs<Stmt>();
215 if (getSwitchStack().empty()) {
216 Diag(DefaultLoc, diag::err_default_not_in_switch);
217 return Owned(SubStmt);
220 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
221 getSwitchStack().back()->addSwitchCase(DS);
225 Action::OwningStmtResult
226 Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
227 SourceLocation ColonLoc, StmtArg subStmt) {
228 Stmt *SubStmt = subStmt.takeAs<Stmt>();
229 // Look up the record for this label identifier.
230 LabelStmt *&LabelDecl = getLabelMap()[II];
232 // If not forward referenced or defined already, just create a new LabelStmt.
234 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt));
236 assert(LabelDecl->getID() == II && "Label mismatch!");
238 // Otherwise, this label was either forward reference or multiply defined. If
239 // multiply defined, reject it now.
240 if (LabelDecl->getSubStmt()) {
241 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID();
242 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition);
243 return Owned(SubStmt);
246 // Otherwise, this label was forward declared, and we just found its real
247 // definition. Fill in the forward definition and return it.
248 LabelDecl->setIdentLoc(IdentLoc);
249 LabelDecl->setSubStmt(SubStmt);
250 return Owned(LabelDecl);
253 Action::OwningStmtResult
254 Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, DeclPtrTy CondVar,
255 StmtArg ThenVal, SourceLocation ElseLoc,
257 OwningExprResult CondResult(CondVal.release());
259 VarDecl *ConditionVar = 0;
261 ConditionVar = CondVar.getAs<VarDecl>();
262 CondResult = CheckConditionVariable(ConditionVar);
263 if (CondResult.isInvalid())
266 Expr *ConditionExpr = CondResult.takeAs<Expr>();
270 if (CheckBooleanCondition(ConditionExpr, IfLoc)) {
271 CondResult = ConditionExpr;
275 Stmt *thenStmt = ThenVal.takeAs<Stmt>();
276 DiagnoseUnusedExprResult(thenStmt);
278 // Warn if the if block has a null body without an else value.
279 // this helps prevent bugs due to typos, such as
282 if (!ElseVal.get()) {
283 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
284 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
287 Stmt *elseStmt = ElseVal.takeAs<Stmt>();
288 DiagnoseUnusedExprResult(elseStmt);
290 CondResult.release();
291 return Owned(new (Context) IfStmt(IfLoc, ConditionVar, ConditionExpr,
292 thenStmt, ElseLoc, elseStmt));
295 Action::OwningStmtResult
296 Sema::ActOnStartOfSwitchStmt(FullExprArg cond, DeclPtrTy CondVar) {
297 OwningExprResult CondResult(cond.release());
299 VarDecl *ConditionVar = 0;
301 ConditionVar = CondVar.getAs<VarDecl>();
302 CondResult = CheckConditionVariable(ConditionVar);
303 if (CondResult.isInvalid())
306 SwitchStmt *SS = new (Context) SwitchStmt(ConditionVar,
307 CondResult.takeAs<Expr>());
308 getSwitchStack().push_back(SS);
312 /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
313 /// the specified width and sign. If an overflow occurs, detect it and emit
314 /// the specified diagnostic.
315 void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val,
316 unsigned NewWidth, bool NewSign,
319 // Perform a conversion to the promoted condition type if needed.
320 if (NewWidth > Val.getBitWidth()) {
321 // If this is an extension, just do it.
322 Val.extend(NewWidth);
323 Val.setIsSigned(NewSign);
325 // If the input was signed and negative and the output is
326 // unsigned, don't bother to warn: this is implementation-defined
328 // FIXME: Introduce a second, default-ignored warning for this case?
329 } else if (NewWidth < Val.getBitWidth()) {
330 // If this is a truncation, check for overflow.
331 llvm::APSInt ConvVal(Val);
332 ConvVal.trunc(NewWidth);
333 ConvVal.setIsSigned(NewSign);
334 ConvVal.extend(Val.getBitWidth());
335 ConvVal.setIsSigned(Val.isSigned());
337 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10);
339 // Regardless of whether a diagnostic was emitted, really do the
342 Val.setIsSigned(NewSign);
343 } else if (NewSign != Val.isSigned()) {
344 // Convert the sign to match the sign of the condition. This can cause
345 // overflow as well: unsigned(INTMIN)
346 // We don't diagnose this overflow, because it is implementation-defined
348 // FIXME: Introduce a second, default-ignored warning for this case?
349 llvm::APSInt OldVal(Val);
350 Val.setIsSigned(NewSign);
355 struct CaseCompareFunctor {
356 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
357 const llvm::APSInt &RHS) {
358 return LHS.first < RHS;
360 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
361 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
362 return LHS.first < RHS.first;
364 bool operator()(const llvm::APSInt &LHS,
365 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
366 return LHS < RHS.first;
371 /// CmpCaseVals - Comparison predicate for sorting case values.
373 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
374 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
375 if (lhs.first < rhs.first)
378 if (lhs.first == rhs.first &&
379 lhs.second->getCaseLoc().getRawEncoding()
380 < rhs.second->getCaseLoc().getRawEncoding())
385 /// CmpEnumVals - Comparison predicate for sorting enumeration values.
387 static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
388 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
390 return lhs.first < rhs.first;
393 /// EqEnumVals - Comparison preficate for uniqing enumeration values.
395 static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs,
396 const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs)
398 return lhs.first == rhs.first;
401 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
402 /// potentially integral-promoted expression @p expr.
403 static QualType GetTypeBeforeIntegralPromotion(const Expr* expr) {
404 const ImplicitCastExpr *ImplicitCast =
405 dyn_cast_or_null<ImplicitCastExpr>(expr);
406 if (ImplicitCast != NULL) {
407 const Expr *ExprBeforePromotion = ImplicitCast->getSubExpr();
408 QualType TypeBeforePromotion = ExprBeforePromotion->getType();
409 if (TypeBeforePromotion->isIntegralType()) {
410 return TypeBeforePromotion;
413 return expr->getType();
416 /// \brief Check (and possibly convert) the condition in a switch
417 /// statement in C++.
418 static bool CheckCXXSwitchCondition(Sema &S, SourceLocation SwitchLoc,
420 if (CondExpr->isTypeDependent())
423 QualType CondType = CondExpr->getType();
426 // The condition shall be of integral type, enumeration type, or of a class
427 // type for which a single conversion function to integral or enumeration
428 // type exists (12.3). If the condition is of class type, the condition is
429 // converted by calling that conversion function, and the result of the
430 // conversion is used in place of the original condition for the remainder
431 // of this section. Integral promotions are performed.
433 // Make sure that the condition expression has a complete type,
434 // otherwise we'll never find any conversions.
435 if (S.RequireCompleteType(SwitchLoc, CondType,
436 S.PDiag(diag::err_switch_incomplete_class_type)
437 << CondExpr->getSourceRange()))
440 UnresolvedSet<4> ViableConversions;
441 UnresolvedSet<4> ExplicitConversions;
442 if (const RecordType *RecordTy = CondType->getAs<RecordType>()) {
443 const UnresolvedSetImpl *Conversions
444 = cast<CXXRecordDecl>(RecordTy->getDecl())
445 ->getVisibleConversionFunctions();
446 for (UnresolvedSetImpl::iterator I = Conversions->begin(),
447 E = Conversions->end(); I != E; ++I) {
448 if (CXXConversionDecl *Conversion
449 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl()))
450 if (Conversion->getConversionType().getNonReferenceType()
451 ->isIntegralType()) {
452 if (Conversion->isExplicit())
453 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
455 ViableConversions.addDecl(I.getDecl(), I.getAccess());
459 switch (ViableConversions.size()) {
461 if (ExplicitConversions.size() == 1) {
462 DeclAccessPair Found = ExplicitConversions[0];
463 CXXConversionDecl *Conversion =
464 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
465 // The user probably meant to invoke the given explicit
466 // conversion; use it.
468 = Conversion->getConversionType().getNonReferenceType();
470 ConvTy.getAsStringInternal(TypeStr, S.Context.PrintingPolicy);
472 S.Diag(SwitchLoc, diag::err_switch_explicit_conversion)
473 << CondType << ConvTy << CondExpr->getSourceRange()
474 << FixItHint::CreateInsertion(CondExpr->getLocStart(),
475 "static_cast<" + TypeStr + ">(")
476 << FixItHint::CreateInsertion(
477 S.PP.getLocForEndOfToken(CondExpr->getLocEnd()),
479 S.Diag(Conversion->getLocation(), diag::note_switch_conversion)
480 << ConvTy->isEnumeralType() << ConvTy;
482 // If we aren't in a SFINAE context, build a call to the
483 // explicit conversion function.
484 if (S.isSFINAEContext())
487 S.CheckMemberOperatorAccess(CondExpr->getExprLoc(),
489 CondExpr = S.BuildCXXMemberCallExpr(CondExpr, Found, Conversion);
492 // We'll complain below about a non-integral condition type.
496 // Apply this conversion.
497 DeclAccessPair Found = ViableConversions[0];
498 S.CheckMemberOperatorAccess(CondExpr->getExprLoc(),
500 CondExpr = S.BuildCXXMemberCallExpr(CondExpr, Found,
501 cast<CXXConversionDecl>(Found->getUnderlyingDecl()));
506 S.Diag(SwitchLoc, diag::err_switch_multiple_conversions)
507 << CondType << CondExpr->getSourceRange();
508 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
509 CXXConversionDecl *Conv
510 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
511 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
512 S.Diag(Conv->getLocation(), diag::note_switch_conversion)
513 << ConvTy->isEnumeralType() << ConvTy;
522 /// ActOnSwitchBodyError - This is called if there is an error parsing the
523 /// body of the switch stmt instead of ActOnFinishSwitchStmt.
524 void Sema::ActOnSwitchBodyError(SourceLocation SwitchLoc, StmtArg Switch,
526 // Keep the switch stack balanced.
527 assert(getSwitchStack().back() == (SwitchStmt*)Switch.get() &&
528 "switch stack missing push/pop!");
529 getSwitchStack().pop_back();
532 Action::OwningStmtResult
533 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch,
535 Stmt *BodyStmt = Body.takeAs<Stmt>();
537 SwitchStmt *SS = getSwitchStack().back();
538 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!");
540 SS->setBody(BodyStmt, SwitchLoc);
541 getSwitchStack().pop_back();
543 if (SS->getCond() == 0) {
544 SS->Destroy(Context);
548 Expr *CondExpr = SS->getCond();
549 QualType CondTypeBeforePromotion =
550 GetTypeBeforeIntegralPromotion(CondExpr);
552 if (getLangOptions().CPlusPlus &&
553 CheckCXXSwitchCondition(*this, SwitchLoc, CondExpr))
556 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
557 UsualUnaryConversions(CondExpr);
558 QualType CondType = CondExpr->getType();
559 SS->setCond(CondExpr);
562 // Integral promotions are performed (on the switch condition).
564 // A case value unrepresentable by the original switch condition
565 // type (before the promotion) doesn't make sense, even when it can
566 // be represented by the promoted type. Therefore we need to find
567 // the pre-promotion type of the switch condition.
568 if (!CondExpr->isTypeDependent()) {
569 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1
570 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer)
571 << CondType << CondExpr->getSourceRange();
575 if (CondTypeBeforePromotion->isBooleanType()) {
576 // switch(bool_expr) {...} is often a programmer error, e.g.
577 // switch(n && mask) { ... } // Doh - should be "n & mask".
578 // One can always use an if statement instead of switch(bool_expr).
579 Diag(SwitchLoc, diag::warn_bool_switch_condition)
580 << CondExpr->getSourceRange();
584 // Get the bitwidth of the switched-on value before promotions. We must
585 // convert the integer case values to this width before comparison.
586 bool HasDependentValue
587 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
589 = HasDependentValue? 0
590 : static_cast<unsigned>(Context.getTypeSize(CondTypeBeforePromotion));
591 bool CondIsSigned = CondTypeBeforePromotion->isSignedIntegerType();
593 // Accumulate all of the case values in a vector so that we can sort them
594 // and detect duplicates. This vector contains the APInt for the case after
595 // it has been converted to the condition type.
596 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
599 // Keep track of any GNU case ranges we see. The APSInt is the low value.
600 typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy;
601 CaseRangesTy CaseRanges;
603 DefaultStmt *TheDefaultStmt = 0;
605 bool CaseListIsErroneous = false;
607 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
608 SC = SC->getNextSwitchCase()) {
610 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
611 if (TheDefaultStmt) {
612 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
613 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
615 // FIXME: Remove the default statement from the switch block so that
616 // we'll return a valid AST. This requires recursing down the AST and
617 // finding it, not something we are set up to do right now. For now,
618 // just lop the entire switch stmt out of the AST.
619 CaseListIsErroneous = true;
624 CaseStmt *CS = cast<CaseStmt>(SC);
626 // We already verified that the expression has a i-c-e value (C99
627 // 6.8.4.2p3) - get that value now.
628 Expr *Lo = CS->getLHS();
630 if (Lo->isTypeDependent() || Lo->isValueDependent()) {
631 HasDependentValue = true;
635 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context);
637 // Convert the value to the same width/sign as the condition.
638 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned,
639 CS->getLHS()->getLocStart(),
640 diag::warn_case_value_overflow);
642 // If the LHS is not the same type as the condition, insert an implicit
644 ImpCastExprToType(Lo, CondType, CastExpr::CK_IntegralCast);
647 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
649 if (CS->getRHS()->isTypeDependent() ||
650 CS->getRHS()->isValueDependent()) {
651 HasDependentValue = true;
654 CaseRanges.push_back(std::make_pair(LoVal, CS));
656 CaseVals.push_back(std::make_pair(LoVal, CS));
660 if (!HasDependentValue) {
661 // Sort all the scalar case values so we can easily detect duplicates.
662 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
664 if (!CaseVals.empty()) {
665 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) {
666 if (CaseVals[i].first == CaseVals[i+1].first) {
667 // If we have a duplicate, report it.
668 Diag(CaseVals[i+1].second->getLHS()->getLocStart(),
669 diag::err_duplicate_case) << CaseVals[i].first.toString(10);
670 Diag(CaseVals[i].second->getLHS()->getLocStart(),
671 diag::note_duplicate_case_prev);
672 // FIXME: We really want to remove the bogus case stmt from the
673 // substmt, but we have no way to do this right now.
674 CaseListIsErroneous = true;
679 // Detect duplicate case ranges, which usually don't exist at all in
681 if (!CaseRanges.empty()) {
682 // Sort all the case ranges by their low value so we can easily detect
683 // overlaps between ranges.
684 std::stable_sort(CaseRanges.begin(), CaseRanges.end());
686 // Scan the ranges, computing the high values and removing empty ranges.
687 std::vector<llvm::APSInt> HiVals;
688 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
689 CaseStmt *CR = CaseRanges[i].second;
690 Expr *Hi = CR->getRHS();
691 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context);
693 // Convert the value to the same width/sign as the condition.
694 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned,
695 CR->getRHS()->getLocStart(),
696 diag::warn_case_value_overflow);
698 // If the LHS is not the same type as the condition, insert an implicit
700 ImpCastExprToType(Hi, CondType, CastExpr::CK_IntegralCast);
703 // If the low value is bigger than the high value, the case is empty.
704 if (CaseRanges[i].first > HiVal) {
705 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range)
706 << SourceRange(CR->getLHS()->getLocStart(),
707 CR->getRHS()->getLocEnd());
708 CaseRanges.erase(CaseRanges.begin()+i);
712 HiVals.push_back(HiVal);
715 // Rescan the ranges, looking for overlap with singleton values and other
716 // ranges. Since the range list is sorted, we only need to compare case
717 // ranges with their neighbors.
718 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
719 llvm::APSInt &CRLo = CaseRanges[i].first;
720 llvm::APSInt &CRHi = HiVals[i];
721 CaseStmt *CR = CaseRanges[i].second;
723 // Check to see whether the case range overlaps with any
725 CaseStmt *OverlapStmt = 0;
726 llvm::APSInt OverlapVal(32);
728 // Find the smallest value >= the lower bound. If I is in the
729 // case range, then we have overlap.
730 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
731 CaseVals.end(), CRLo,
732 CaseCompareFunctor());
733 if (I != CaseVals.end() && I->first < CRHi) {
734 OverlapVal = I->first; // Found overlap with scalar.
735 OverlapStmt = I->second;
738 // Find the smallest value bigger than the upper bound.
739 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
740 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
741 OverlapVal = (I-1)->first; // Found overlap with scalar.
742 OverlapStmt = (I-1)->second;
745 // Check to see if this case stmt overlaps with the subsequent
747 if (i && CRLo <= HiVals[i-1]) {
748 OverlapVal = HiVals[i-1]; // Found overlap with range.
749 OverlapStmt = CaseRanges[i-1].second;
753 // If we have a duplicate, report it.
754 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case)
755 << OverlapVal.toString(10);
756 Diag(OverlapStmt->getLHS()->getLocStart(),
757 diag::note_duplicate_case_prev);
758 // FIXME: We really want to remove the bogus case stmt from the
759 // substmt, but we have no way to do this right now.
760 CaseListIsErroneous = true;
765 // Check to see if switch is over an Enum and handles all of its
767 const EnumType* ET = CondTypeBeforePromotion->getAs<EnumType>();
768 // If switch has default case, then ignore it.
769 if (!CaseListIsErroneous && !TheDefaultStmt && ET) {
770 const EnumDecl *ED = ET->getDecl();
771 typedef llvm::SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy;
774 // Gather all enum values, set their type and sort them, allowing easier comparison
776 for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); EDI != ED->enumerator_end(); EDI++) {
777 llvm::APSInt Val = (*EDI)->getInitVal();
778 if(Val.getBitWidth() < CondWidth)
779 Val.extend(CondWidth);
780 Val.setIsSigned(CondIsSigned);
781 EnumVals.push_back(std::make_pair(Val, (*EDI)));
783 std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals);
784 EnumValsTy::iterator EIend = std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals);
785 // See which case values aren't in enum
786 EnumValsTy::const_iterator EI = EnumVals.begin();
787 for (CaseValsTy::const_iterator CI = CaseVals.begin(); CI != CaseVals.end(); CI++) {
788 while (EI != EIend && EI->first < CI->first)
790 if (EI == EIend || EI->first > CI->first)
791 Diag(CI->second->getLHS()->getExprLoc(), diag::not_in_enum) << ED->getDeclName();
793 // See which of case ranges aren't in enum
794 EI = EnumVals.begin();
795 for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); RI != CaseRanges.end() && EI != EIend; RI++) {
796 while (EI != EIend && EI->first < RI->first)
799 if (EI == EIend || EI->first != RI->first) {
800 Diag(RI->second->getLHS()->getExprLoc(), diag::not_in_enum) << ED->getDeclName();
803 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context);
804 while (EI != EIend && EI->first < Hi)
806 if (EI == EIend || EI->first != Hi)
807 Diag(RI->second->getRHS()->getExprLoc(), diag::not_in_enum) << ED->getDeclName();
809 //Check which enum vals aren't in switch
810 CaseValsTy::const_iterator CI = CaseVals.begin();
811 CaseRangesTy::const_iterator RI = CaseRanges.begin();
812 EI = EnumVals.begin();
813 for (; EI != EIend; EI++) {
814 //Drop unneeded case values
816 while (CI != CaseVals.end() && CI->first < EI->first)
819 if (CI != CaseVals.end() && CI->first == EI->first)
822 //Drop unneeded case ranges
823 for (; RI != CaseRanges.end(); RI++) {
824 llvm::APSInt Hi = RI->second->getRHS()->EvaluateAsInt(Context);
829 if (RI == CaseRanges.end() || EI->first < RI->first)
830 Diag(CondExpr->getExprLoc(), diag::warn_missing_cases) << EI->second->getDeclName();
835 // FIXME: If the case list was broken is some way, we don't have a good system
836 // to patch it up. Instead, just return the whole substmt as broken.
837 if (CaseListIsErroneous)
844 Action::OwningStmtResult
845 Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond,
846 DeclPtrTy CondVar, StmtArg Body) {
847 OwningExprResult CondResult(Cond.release());
849 VarDecl *ConditionVar = 0;
851 ConditionVar = CondVar.getAs<VarDecl>();
852 CondResult = CheckConditionVariable(ConditionVar);
853 if (CondResult.isInvalid())
856 Expr *ConditionExpr = CondResult.takeAs<Expr>();
860 if (CheckBooleanCondition(ConditionExpr, WhileLoc)) {
861 CondResult = ConditionExpr;
865 Stmt *bodyStmt = Body.takeAs<Stmt>();
866 DiagnoseUnusedExprResult(bodyStmt);
868 CondResult.release();
869 return Owned(new (Context) WhileStmt(ConditionVar, ConditionExpr, bodyStmt,
873 Action::OwningStmtResult
874 Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body,
875 SourceLocation WhileLoc, SourceLocation CondLParen,
876 ExprArg Cond, SourceLocation CondRParen) {
877 Expr *condExpr = Cond.takeAs<Expr>();
878 assert(condExpr && "ActOnDoStmt(): missing expression");
880 if (CheckBooleanCondition(condExpr, DoLoc)) {
885 Stmt *bodyStmt = Body.takeAs<Stmt>();
886 DiagnoseUnusedExprResult(bodyStmt);
889 return Owned(new (Context) DoStmt(bodyStmt, condExpr, DoLoc,
890 WhileLoc, CondRParen));
893 Action::OwningStmtResult
894 Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
895 StmtArg first, FullExprArg second, DeclPtrTy secondVar,
897 SourceLocation RParenLoc, StmtArg body) {
898 Stmt *First = static_cast<Stmt*>(first.get());
900 if (!getLangOptions().CPlusPlus) {
901 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
902 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
903 // declare identifiers for objects having storage class 'auto' or
905 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end();
907 VarDecl *VD = dyn_cast<VarDecl>(*DI);
908 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage())
911 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
912 // FIXME: mark decl erroneous!
917 OwningExprResult SecondResult(second.release());
918 VarDecl *ConditionVar = 0;
919 if (secondVar.get()) {
920 ConditionVar = secondVar.getAs<VarDecl>();
921 SecondResult = CheckConditionVariable(ConditionVar);
922 if (SecondResult.isInvalid())
926 Expr *Second = SecondResult.takeAs<Expr>();
927 if (Second && CheckBooleanCondition(Second, ForLoc)) {
928 SecondResult = Second;
932 Expr *Third = third.release().takeAs<Expr>();
933 Stmt *Body = static_cast<Stmt*>(body.get());
935 DiagnoseUnusedExprResult(First);
936 DiagnoseUnusedExprResult(Third);
937 DiagnoseUnusedExprResult(Body);
941 return Owned(new (Context) ForStmt(First, Second, ConditionVar, Third, Body,
942 ForLoc, LParenLoc, RParenLoc));
945 Action::OwningStmtResult
946 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
947 SourceLocation LParenLoc,
948 StmtArg first, ExprArg second,
949 SourceLocation RParenLoc, StmtArg body) {
950 Stmt *First = static_cast<Stmt*>(first.get());
951 Expr *Second = static_cast<Expr*>(second.get());
952 Stmt *Body = static_cast<Stmt*>(body.get());
955 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
956 if (!DS->isSingleDecl())
957 return StmtError(Diag((*DS->decl_begin())->getLocation(),
958 diag::err_toomany_element_decls));
960 Decl *D = DS->getSingleDecl();
961 FirstType = cast<ValueDecl>(D)->getType();
962 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
963 // declare identifiers for objects having storage class 'auto' or
965 VarDecl *VD = cast<VarDecl>(D);
966 if (VD->isBlockVarDecl() && !VD->hasLocalStorage())
967 return StmtError(Diag(VD->getLocation(),
968 diag::err_non_variable_decl_in_for));
970 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid)
971 return StmtError(Diag(First->getLocStart(),
972 diag::err_selector_element_not_lvalue)
973 << First->getSourceRange());
975 FirstType = static_cast<Expr*>(First)->getType();
977 if (!FirstType->isObjCObjectPointerType() &&
978 !FirstType->isBlockPointerType())
979 Diag(ForLoc, diag::err_selector_element_type)
980 << FirstType << First->getSourceRange();
983 DefaultFunctionArrayLvalueConversion(Second);
984 QualType SecondType = Second->getType();
985 if (!SecondType->isObjCObjectPointerType())
986 Diag(ForLoc, diag::err_collection_expr_type)
987 << SecondType << Second->getSourceRange();
992 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body,
996 Action::OwningStmtResult
997 Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc,
998 IdentifierInfo *LabelII) {
999 // Look up the record for this label identifier.
1000 LabelStmt *&LabelDecl = getLabelMap()[LabelII];
1002 // If we haven't seen this label yet, create a forward reference.
1004 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0);
1006 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc));
1009 Action::OwningStmtResult
1010 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
1012 // Convert operand to void*
1013 Expr* E = DestExp.takeAs<Expr>();
1014 if (!E->isTypeDependent()) {
1015 QualType ETy = E->getType();
1016 QualType DestTy = Context.getPointerType(Context.VoidTy.withConst());
1017 AssignConvertType ConvTy =
1018 CheckSingleAssignmentConstraints(DestTy, E);
1019 if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing))
1022 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E));
1025 Action::OwningStmtResult
1026 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
1027 Scope *S = CurScope->getContinueParent();
1029 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
1030 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
1033 return Owned(new (Context) ContinueStmt(ContinueLoc));
1036 Action::OwningStmtResult
1037 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
1038 Scope *S = CurScope->getBreakParent();
1040 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
1041 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
1044 return Owned(new (Context) BreakStmt(BreakLoc));
1047 /// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
1049 Action::OwningStmtResult
1050 Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
1051 // If this is the first return we've seen in the block, infer the type of
1052 // the block from it.
1053 BlockScopeInfo *CurBlock = getCurBlock();
1054 if (CurBlock->ReturnType.isNull()) {
1056 // Don't call UsualUnaryConversions(), since we don't want to do
1057 // integer promotions here.
1058 DefaultFunctionArrayLvalueConversion(RetValExp);
1059 CurBlock->ReturnType = RetValExp->getType();
1060 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) {
1061 // We have to remove a 'const' added to copied-in variable which was
1062 // part of the implementation spec. and not the actual qualifier for
1064 if (CDRE->isConstQualAdded())
1065 CurBlock->ReturnType.removeConst();
1068 CurBlock->ReturnType = Context.VoidTy;
1070 QualType FnRetType = CurBlock->ReturnType;
1072 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) {
1073 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr)
1074 << getCurFunctionOrMethodDecl()->getDeclName();
1078 // Otherwise, verify that this result type matches the previous one. We are
1079 // pickier with blocks than for normal functions because we don't have GCC
1080 // compatibility to worry about here.
1081 if (CurBlock->ReturnType->isVoidType()) {
1083 Diag(ReturnLoc, diag::err_return_block_has_expr);
1084 RetValExp->Destroy(Context);
1087 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1091 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
1093 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
1094 // we have a non-void block with an expression, continue checking
1096 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
1097 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
1100 // In C++ the return statement is handled via a copy initialization.
1101 // the C version of which boils down to CheckSingleAssignmentConstraints.
1102 OwningExprResult Res = PerformCopyInitialization(
1103 InitializedEntity::InitializeResult(ReturnLoc,
1107 if (Res.isInvalid()) {
1108 // FIXME: Cleanup temporaries here, anyway?
1112 RetValExp = Res.takeAs<Expr>();
1114 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
1117 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1120 /// IsReturnCopyElidable - Whether returning @p RetExpr from a function that
1121 /// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15).
1122 static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType,
1124 QualType ExprType = RetExpr->getType();
1125 // - in a return statement in a function with ...
1126 // ... a class return type ...
1127 if (!RetType->isRecordType())
1129 // ... the same cv-unqualified type as the function return type ...
1130 if (!Ctx.hasSameUnqualifiedType(RetType, ExprType))
1132 // ... the expression is the name of a non-volatile automatic object ...
1133 // We ignore parentheses here.
1134 // FIXME: Is this compliant?
1135 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens());
1138 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
1141 return VD->hasLocalStorage() && !VD->getType()->isReferenceType()
1142 && !VD->getType().isVolatileQualified();
1145 Action::OwningStmtResult
1146 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) {
1147 Expr *RetValExp = rex.takeAs<Expr>();
1149 return ActOnBlockReturnStmt(ReturnLoc, RetValExp);
1152 if (const FunctionDecl *FD = getCurFunctionDecl()) {
1153 FnRetType = FD->getResultType();
1154 if (FD->hasAttr<NoReturnAttr>() ||
1155 FD->getType()->getAs<FunctionType>()->getNoReturnAttr())
1156 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
1157 << getCurFunctionOrMethodDecl()->getDeclName();
1158 } else if (ObjCMethodDecl *MD = getCurMethodDecl())
1159 FnRetType = MD->getResultType();
1160 else // If we don't have a function/method context, bail.
1163 if (FnRetType->isVoidType()) {
1164 if (RetValExp && !RetValExp->isTypeDependent()) {
1165 // C99 6.8.6.4p1 (ext_ since GCC warns)
1166 unsigned D = diag::ext_return_has_expr;
1167 if (RetValExp->getType()->isVoidType())
1168 D = diag::ext_return_has_void_expr;
1170 // return (some void expression); is legal in C++.
1171 if (D != diag::ext_return_has_void_expr ||
1172 !getLangOptions().CPlusPlus) {
1173 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
1175 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl)
1176 << RetValExp->getSourceRange();
1179 RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp);
1181 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1184 if (!RetValExp && !FnRetType->isDependentType()) {
1185 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4
1186 // C99 6.8.6.4p1 (ext_ since GCC warns)
1187 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr;
1189 if (FunctionDecl *FD = getCurFunctionDecl())
1190 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
1192 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
1193 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0));
1196 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
1197 // we have a non-void function with an expression, continue checking
1199 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
1200 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
1203 // C++0x 12.8p15: When certain criteria are met, an implementation is
1204 // allowed to omit the copy construction of a class object, [...]
1205 // - in a return statement in a function with a class return type, when
1206 // the expression is the name of a non-volatile automatic object with
1207 // the same cv-unqualified type as the function return type, the copy
1208 // operation can be omitted [...]
1209 // C++0x 12.8p16: When the criteria for elision of a copy operation are met
1210 // and the object to be copied is designated by an lvalue, overload
1211 // resolution to select the constructor for the copy is first performed
1212 // as if the object were designated by an rvalue.
1213 // Note that we only compute Elidable if we're in C++0x, since we don't
1215 bool Elidable = getLangOptions().CPlusPlus0x ?
1216 IsReturnCopyElidable(Context, FnRetType, RetValExp) :
1221 // In C++ the return statement is handled via a copy initialization.
1222 // the C version of which boils down to CheckSingleAssignmentConstraints.
1223 OwningExprResult Res = PerformCopyInitialization(
1224 InitializedEntity::InitializeResult(ReturnLoc,
1228 if (Res.isInvalid()) {
1229 // FIXME: Cleanup temporaries here, anyway?
1233 RetValExp = Res.takeAs<Expr>();
1235 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
1239 RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp);
1240 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1243 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
1244 /// ignore "noop" casts in places where an lvalue is required by an inline asm.
1245 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but
1246 /// provide a strong guidance to not use it.
1248 /// This method checks to see if the argument is an acceptable l-value and
1249 /// returns false if it is a case we can handle.
1250 static bool CheckAsmLValue(const Expr *E, Sema &S) {
1251 // Type dependent expressions will be checked during instantiation.
1252 if (E->isTypeDependent())
1255 if (E->isLvalue(S.Context) == Expr::LV_Valid)
1256 return false; // Cool, this is an lvalue.
1258 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we
1259 // are supposed to allow.
1260 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
1261 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) {
1262 if (!S.getLangOptions().HeinousExtensions)
1263 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue)
1264 << E->getSourceRange();
1266 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
1267 << E->getSourceRange();
1268 // Accept, even if we emitted an error diagnostic.
1272 // None of the above, just randomly invalid non-lvalue.
1277 Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc,
1280 unsigned NumOutputs,
1282 IdentifierInfo **Names,
1283 MultiExprArg constraints,
1286 MultiExprArg clobbers,
1287 SourceLocation RParenLoc,
1289 unsigned NumClobbers = clobbers.size();
1290 StringLiteral **Constraints =
1291 reinterpret_cast<StringLiteral**>(constraints.get());
1292 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get());
1293 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get());
1294 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get());
1296 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
1298 // The parser verifies that there is a string literal here.
1299 if (AsmString->isWide())
1300 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character)
1301 << AsmString->getSourceRange());
1303 for (unsigned i = 0; i != NumOutputs; i++) {
1304 StringLiteral *Literal = Constraints[i];
1305 if (Literal->isWide())
1306 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1307 << Literal->getSourceRange());
1309 llvm::StringRef OutputName;
1311 OutputName = Names[i]->getName();
1313 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName);
1314 if (!Context.Target.validateOutputConstraint(Info))
1315 return StmtError(Diag(Literal->getLocStart(),
1316 diag::err_asm_invalid_output_constraint)
1317 << Info.getConstraintStr());
1319 // Check that the output exprs are valid lvalues.
1320 Expr *OutputExpr = Exprs[i];
1321 if (CheckAsmLValue(OutputExpr, *this)) {
1322 return StmtError(Diag(OutputExpr->getLocStart(),
1323 diag::err_asm_invalid_lvalue_in_output)
1324 << OutputExpr->getSourceRange());
1327 OutputConstraintInfos.push_back(Info);
1330 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
1332 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
1333 StringLiteral *Literal = Constraints[i];
1334 if (Literal->isWide())
1335 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1336 << Literal->getSourceRange());
1338 llvm::StringRef InputName;
1340 InputName = Names[i]->getName();
1342 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName);
1343 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(),
1344 NumOutputs, Info)) {
1345 return StmtError(Diag(Literal->getLocStart(),
1346 diag::err_asm_invalid_input_constraint)
1347 << Info.getConstraintStr());
1350 Expr *InputExpr = Exprs[i];
1352 // Only allow void types for memory constraints.
1353 if (Info.allowsMemory() && !Info.allowsRegister()) {
1354 if (CheckAsmLValue(InputExpr, *this))
1355 return StmtError(Diag(InputExpr->getLocStart(),
1356 diag::err_asm_invalid_lvalue_in_input)
1357 << Info.getConstraintStr()
1358 << InputExpr->getSourceRange());
1361 if (Info.allowsRegister()) {
1362 if (InputExpr->getType()->isVoidType()) {
1363 return StmtError(Diag(InputExpr->getLocStart(),
1364 diag::err_asm_invalid_type_in_input)
1365 << InputExpr->getType() << Info.getConstraintStr()
1366 << InputExpr->getSourceRange());
1370 DefaultFunctionArrayLvalueConversion(Exprs[i]);
1372 InputConstraintInfos.push_back(Info);
1375 // Check that the clobbers are valid.
1376 for (unsigned i = 0; i != NumClobbers; i++) {
1377 StringLiteral *Literal = Clobbers[i];
1378 if (Literal->isWide())
1379 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1380 << Literal->getSourceRange());
1382 llvm::StringRef Clobber = Literal->getString();
1384 if (!Context.Target.isValidGCCRegisterName(Clobber))
1385 return StmtError(Diag(Literal->getLocStart(),
1386 diag::err_asm_unknown_register_name) << Clobber);
1389 constraints.release();
1391 asmString.release();
1394 new (Context) AsmStmt(Context, AsmLoc, IsSimple, IsVolatile, MSAsm,
1395 NumOutputs, NumInputs, Names, Constraints, Exprs,
1396 AsmString, NumClobbers, Clobbers, RParenLoc);
1397 // Validate the asm string, ensuring it makes sense given the operands we
1399 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces;
1401 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
1402 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
1403 << AsmString->getSourceRange();
1408 // Validate tied input operands for type mismatches.
1409 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
1410 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
1412 // If this is a tied constraint, verify that the output and input have
1413 // either exactly the same type, or that they are int/ptr operands with the
1414 // same size (int/long, int*/long, are ok etc).
1415 if (!Info.hasTiedOperand()) continue;
1417 unsigned TiedTo = Info.getTiedOperand();
1418 Expr *OutputExpr = Exprs[TiedTo];
1419 Expr *InputExpr = Exprs[i+NumOutputs];
1420 QualType InTy = InputExpr->getType();
1421 QualType OutTy = OutputExpr->getType();
1422 if (Context.hasSameType(InTy, OutTy))
1423 continue; // All types can be tied to themselves.
1425 // Int/ptr operands have some special cases that we allow.
1426 if ((OutTy->isIntegerType() || OutTy->isPointerType()) &&
1427 (InTy->isIntegerType() || InTy->isPointerType())) {
1429 // They are ok if they are the same size. Tying void* to int is ok if
1430 // they are the same size, for example. This also allows tying void* to
1432 uint64_t OutSize = Context.getTypeSize(OutTy);
1433 uint64_t InSize = Context.getTypeSize(InTy);
1434 if (OutSize == InSize)
1437 // If the smaller input/output operand is not mentioned in the asm string,
1438 // then we can promote it and the asm string won't notice. Check this
1440 bool SmallerValueMentioned = false;
1441 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) {
1442 AsmStmt::AsmStringPiece &Piece = Pieces[p];
1443 if (!Piece.isOperand()) continue;
1445 // If this is a reference to the input and if the input was the smaller
1446 // one, then we have to reject this asm.
1447 if (Piece.getOperandNo() == i+NumOutputs) {
1448 if (InSize < OutSize) {
1449 SmallerValueMentioned = true;
1454 // If this is a reference to the input and if the input was the smaller
1455 // one, then we have to reject this asm.
1456 if (Piece.getOperandNo() == TiedTo) {
1457 if (InSize > OutSize) {
1458 SmallerValueMentioned = true;
1464 // If the smaller value wasn't mentioned in the asm string, and if the
1465 // output was a register, just extend the shorter one to the size of the
1467 if (!SmallerValueMentioned &&
1468 OutputConstraintInfos[TiedTo].allowsRegister())
1472 Diag(InputExpr->getLocStart(),
1473 diag::err_asm_tying_incompatible_types)
1474 << InTy << OutTy << OutputExpr->getSourceRange()
1475 << InputExpr->getSourceRange();
1483 Action::OwningStmtResult
1484 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
1485 SourceLocation RParen, DeclPtrTy Parm,
1486 StmtArg Body, StmtArg catchList) {
1487 Stmt *CatchList = catchList.takeAs<Stmt>();
1488 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>());
1490 // PVD == 0 implies @catch(...).
1492 // If we already know the decl is invalid, reject it.
1493 if (PVD->isInvalidDecl())
1496 if (!PVD->getType()->isObjCObjectPointerType())
1497 return StmtError(Diag(PVD->getLocation(),
1498 diag::err_catch_param_not_objc_type));
1499 if (PVD->getType()->isObjCQualifiedIdType())
1500 return StmtError(Diag(PVD->getLocation(),
1501 diag::err_illegal_qualifiers_on_catch_parm));
1504 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen,
1505 PVD, Body.takeAs<Stmt>(), CatchList);
1506 return Owned(CatchList ? CatchList : CS);
1509 Action::OwningStmtResult
1510 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) {
1511 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc,
1512 static_cast<Stmt*>(Body.release())));
1515 Action::OwningStmtResult
1516 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc,
1517 StmtArg Try, StmtArg Catch, StmtArg Finally) {
1518 FunctionNeedsScopeChecking() = true;
1519 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(),
1520 Catch.takeAs<Stmt>(),
1521 Finally.takeAs<Stmt>()));
1524 Action::OwningStmtResult
1525 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) {
1526 Expr *ThrowExpr = expr.takeAs<Expr>();
1528 // @throw without an expression designates a rethrow (which much occur
1529 // in the context of an @catch clause).
1530 Scope *AtCatchParent = CurScope;
1531 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
1532 AtCatchParent = AtCatchParent->getParent();
1534 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch));
1536 QualType ThrowType = ThrowExpr->getType();
1537 // Make sure the expression type is an ObjC pointer or "void *".
1538 if (!ThrowType->isObjCObjectPointerType()) {
1539 const PointerType *PT = ThrowType->getAs<PointerType>();
1540 if (!PT || !PT->getPointeeType()->isVoidType())
1541 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object)
1542 << ThrowExpr->getType() << ThrowExpr->getSourceRange());
1545 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr));
1548 Action::OwningStmtResult
1549 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr,
1550 StmtArg SynchBody) {
1551 FunctionNeedsScopeChecking() = true;
1553 // Make sure the expression type is an ObjC pointer or "void *".
1554 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get());
1555 if (!SyncExpr->getType()->isObjCObjectPointerType()) {
1556 const PointerType *PT = SyncExpr->getType()->getAs<PointerType>();
1557 if (!PT || !PT->getPointeeType()->isVoidType())
1558 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object)
1559 << SyncExpr->getType() << SyncExpr->getSourceRange());
1562 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc,
1563 SynchExpr.takeAs<Stmt>(),
1564 SynchBody.takeAs<Stmt>()));
1567 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
1568 /// and creates a proper catch handler from them.
1569 Action::OwningStmtResult
1570 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl,
1571 StmtArg HandlerBlock) {
1572 // There's nothing to test that ActOnExceptionDecl didn't already test.
1573 return Owned(new (Context) CXXCatchStmt(CatchLoc,
1574 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()),
1575 HandlerBlock.takeAs<Stmt>()));
1578 class TypeWithHandler {
1582 TypeWithHandler(const QualType &type, CXXCatchStmt *statement)
1583 : t(type), stmt(statement) {}
1585 // An arbitrary order is fine as long as it places identical
1586 // types next to each other.
1587 bool operator<(const TypeWithHandler &y) const {
1588 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr())
1590 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr())
1593 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc();
1596 bool operator==(const TypeWithHandler& other) const {
1597 return t == other.t;
1600 QualType getQualType() const { return t; }
1601 CXXCatchStmt *getCatchStmt() const { return stmt; }
1602 SourceLocation getTypeSpecStartLoc() const {
1603 return stmt->getExceptionDecl()->getTypeSpecStartLoc();
1607 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of
1608 /// handlers and creates a try statement from them.
1609 Action::OwningStmtResult
1610 Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock,
1611 MultiStmtArg RawHandlers) {
1612 unsigned NumHandlers = RawHandlers.size();
1613 assert(NumHandlers > 0 &&
1614 "The parser shouldn't call this if there are no handlers.");
1615 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get());
1617 llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers;
1619 for (unsigned i = 0; i < NumHandlers; ++i) {
1620 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]);
1621 if (!Handler->getExceptionDecl()) {
1622 if (i < NumHandlers - 1)
1623 return StmtError(Diag(Handler->getLocStart(),
1624 diag::err_early_catch_all));
1629 const QualType CaughtType = Handler->getCaughtType();
1630 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType);
1631 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler));
1634 // Detect handlers for the same type as an earlier one.
1635 if (NumHandlers > 1) {
1636 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end());
1638 TypeWithHandler prev = TypesWithHandlers[0];
1639 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) {
1640 TypeWithHandler curr = TypesWithHandlers[i];
1643 Diag(curr.getTypeSpecStartLoc(),
1644 diag::warn_exception_caught_by_earlier_handler)
1645 << curr.getCatchStmt()->getCaughtType().getAsString();
1646 Diag(prev.getTypeSpecStartLoc(),
1647 diag::note_previous_exception_handler)
1648 << prev.getCatchStmt()->getCaughtType().getAsString();
1655 // FIXME: We should detect handlers that cannot catch anything because an
1656 // earlier handler catches a superclass. Need to find a method that is not
1657 // quadratic for this.
1658 // Neither of these are explicitly forbidden, but every compiler detects them
1661 FunctionNeedsScopeChecking() = true;
1662 RawHandlers.release();
1663 return Owned(CXXTryStmt::Create(Context, TryLoc,
1664 static_cast<Stmt*>(TryBlock.release()),
1665 Handlers, NumHandlers));