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);
79 // Ignore expressions that have void type.
80 if (E->getType()->isVoidType())
85 if (!E->isUnusedResultAWarning(Loc, R1, R2, Context))
88 // Okay, we have an unused result. Depending on what the base expression is,
89 // we might want to make a more specific diagnostic. Check for one of these
91 unsigned DiagID = diag::warn_unused_expr;
92 E = E->IgnoreParens();
93 if (isa<ObjCImplicitSetterGetterRefExpr>(E))
94 DiagID = diag::warn_unused_property_expr;
96 if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
97 // If the callee has attribute pure, const, or warn_unused_result, warn with
98 // a more specific message to make it clear what is happening.
99 if (const Decl *FD = CE->getCalleeDecl()) {
100 if (FD->getAttr<WarnUnusedResultAttr>()) {
101 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
104 if (FD->getAttr<PureAttr>()) {
105 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
108 if (FD->getAttr<ConstAttr>()) {
109 Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const";
115 Diag(Loc, DiagID) << R1 << R2;
118 Action::OwningStmtResult
119 Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R,
120 MultiStmtArg elts, bool isStmtExpr) {
121 unsigned NumElts = elts.size();
122 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release());
123 // If we're in C89 mode, check that we don't have any decls after stmts. If
124 // so, emit an extension diagnostic.
125 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) {
126 // Note that __extension__ can be around a decl.
128 // Skip over all declarations.
129 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i)
132 // We found the end of the list or a statement. Scan for another declstmt.
133 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i)
137 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin();
138 Diag(D->getLocation(), diag::ext_mixed_decls_code);
141 // Warn about unused expressions in statements.
142 for (unsigned i = 0; i != NumElts; ++i) {
143 // Ignore statements that are last in a statement expression.
144 if (isStmtExpr && i == NumElts - 1)
147 DiagnoseUnusedExprResult(Elts[i]);
150 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R));
153 Action::OwningStmtResult
154 Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval,
155 SourceLocation DotDotDotLoc, ExprArg rhsval,
156 SourceLocation ColonLoc) {
157 assert((lhsval.get() != 0) && "missing expression in case statement");
159 // C99 6.8.4.2p3: The expression shall be an integer constant.
160 // However, GCC allows any evaluatable integer expression.
161 Expr *LHSVal = static_cast<Expr*>(lhsval.get());
162 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() &&
163 VerifyIntegerConstantExpression(LHSVal))
166 // GCC extension: The expression shall be an integer constant.
168 Expr *RHSVal = static_cast<Expr*>(rhsval.get());
169 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() &&
170 VerifyIntegerConstantExpression(RHSVal)) {
171 RHSVal = 0; // Recover by just forgetting about it.
175 if (getSwitchStack().empty()) {
176 Diag(CaseLoc, diag::err_case_not_in_switch);
180 // Only now release the smart pointers.
183 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc,
185 getSwitchStack().back()->addSwitchCase(CS);
189 /// ActOnCaseStmtBody - This installs a statement as the body of a case.
190 void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) {
191 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt);
192 Stmt *SubStmt = subStmt.takeAs<Stmt>();
193 CS->setSubStmt(SubStmt);
196 Action::OwningStmtResult
197 Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc,
198 StmtArg subStmt, Scope *CurScope) {
199 Stmt *SubStmt = subStmt.takeAs<Stmt>();
201 if (getSwitchStack().empty()) {
202 Diag(DefaultLoc, diag::err_default_not_in_switch);
203 return Owned(SubStmt);
206 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt);
207 getSwitchStack().back()->addSwitchCase(DS);
211 Action::OwningStmtResult
212 Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II,
213 SourceLocation ColonLoc, StmtArg subStmt) {
214 Stmt *SubStmt = subStmt.takeAs<Stmt>();
215 // Look up the record for this label identifier.
216 LabelStmt *&LabelDecl = getLabelMap()[II];
218 // If not forward referenced or defined already, just create a new LabelStmt.
220 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt));
222 assert(LabelDecl->getID() == II && "Label mismatch!");
224 // Otherwise, this label was either forward reference or multiply defined. If
225 // multiply defined, reject it now.
226 if (LabelDecl->getSubStmt()) {
227 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID();
228 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition);
229 return Owned(SubStmt);
232 // Otherwise, this label was forward declared, and we just found its real
233 // definition. Fill in the forward definition and return it.
234 LabelDecl->setIdentLoc(IdentLoc);
235 LabelDecl->setSubStmt(SubStmt);
236 return Owned(LabelDecl);
239 Action::OwningStmtResult
240 Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, DeclPtrTy CondVar,
241 StmtArg ThenVal, SourceLocation ElseLoc,
243 OwningExprResult CondResult(CondVal.release());
245 VarDecl *ConditionVar = 0;
247 ConditionVar = CondVar.getAs<VarDecl>();
248 CondResult = CheckConditionVariable(ConditionVar);
249 if (CondResult.isInvalid())
252 Expr *ConditionExpr = CondResult.takeAs<Expr>();
256 if (CheckBooleanCondition(ConditionExpr, IfLoc)) {
257 CondResult = ConditionExpr;
261 Stmt *thenStmt = ThenVal.takeAs<Stmt>();
262 DiagnoseUnusedExprResult(thenStmt);
264 // Warn if the if block has a null body without an else value.
265 // this helps prevent bugs due to typos, such as
268 if (!ElseVal.get()) {
269 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt))
270 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body);
273 Stmt *elseStmt = ElseVal.takeAs<Stmt>();
274 DiagnoseUnusedExprResult(elseStmt);
276 CondResult.release();
277 return Owned(new (Context) IfStmt(IfLoc, ConditionVar, ConditionExpr,
278 thenStmt, ElseLoc, elseStmt));
281 Action::OwningStmtResult
282 Sema::ActOnStartOfSwitchStmt(FullExprArg cond, DeclPtrTy CondVar) {
283 OwningExprResult CondResult(cond.release());
285 VarDecl *ConditionVar = 0;
287 ConditionVar = CondVar.getAs<VarDecl>();
288 CondResult = CheckConditionVariable(ConditionVar);
289 if (CondResult.isInvalid())
292 SwitchStmt *SS = new (Context) SwitchStmt(ConditionVar,
293 CondResult.takeAs<Expr>());
294 getSwitchStack().push_back(SS);
298 /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
299 /// the specified width and sign. If an overflow occurs, detect it and emit
300 /// the specified diagnostic.
301 void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val,
302 unsigned NewWidth, bool NewSign,
305 // Perform a conversion to the promoted condition type if needed.
306 if (NewWidth > Val.getBitWidth()) {
307 // If this is an extension, just do it.
308 llvm::APSInt OldVal(Val);
309 Val.extend(NewWidth);
311 // If the input was signed and negative and the output is unsigned,
313 if (!NewSign && OldVal.isSigned() && OldVal.isNegative())
314 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10);
316 Val.setIsSigned(NewSign);
317 } else if (NewWidth < Val.getBitWidth()) {
318 // If this is a truncation, check for overflow.
319 llvm::APSInt ConvVal(Val);
320 ConvVal.trunc(NewWidth);
321 ConvVal.setIsSigned(NewSign);
322 ConvVal.extend(Val.getBitWidth());
323 ConvVal.setIsSigned(Val.isSigned());
325 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10);
327 // Regardless of whether a diagnostic was emitted, really do the
330 Val.setIsSigned(NewSign);
331 } else if (NewSign != Val.isSigned()) {
332 // Convert the sign to match the sign of the condition. This can cause
333 // overflow as well: unsigned(INTMIN)
334 llvm::APSInt OldVal(Val);
335 Val.setIsSigned(NewSign);
337 if (Val.isNegative()) // Sign bit changes meaning.
338 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10);
343 struct CaseCompareFunctor {
344 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
345 const llvm::APSInt &RHS) {
346 return LHS.first < RHS;
348 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS,
349 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
350 return LHS.first < RHS.first;
352 bool operator()(const llvm::APSInt &LHS,
353 const std::pair<llvm::APSInt, CaseStmt*> &RHS) {
354 return LHS < RHS.first;
359 /// CmpCaseVals - Comparison predicate for sorting case values.
361 static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs,
362 const std::pair<llvm::APSInt, CaseStmt*>& rhs) {
363 if (lhs.first < rhs.first)
366 if (lhs.first == rhs.first &&
367 lhs.second->getCaseLoc().getRawEncoding()
368 < rhs.second->getCaseLoc().getRawEncoding())
373 /// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of
374 /// potentially integral-promoted expression @p expr.
375 static QualType GetTypeBeforeIntegralPromotion(const Expr* expr) {
376 const ImplicitCastExpr *ImplicitCast =
377 dyn_cast_or_null<ImplicitCastExpr>(expr);
378 if (ImplicitCast != NULL) {
379 const Expr *ExprBeforePromotion = ImplicitCast->getSubExpr();
380 QualType TypeBeforePromotion = ExprBeforePromotion->getType();
381 if (TypeBeforePromotion->isIntegralType()) {
382 return TypeBeforePromotion;
385 return expr->getType();
388 /// \brief Check (and possibly convert) the condition in a switch
389 /// statement in C++.
390 static bool CheckCXXSwitchCondition(Sema &S, SourceLocation SwitchLoc,
392 if (CondExpr->isTypeDependent())
395 QualType CondType = CondExpr->getType();
398 // The condition shall be of integral type, enumeration type, or of a class
399 // type for which a single conversion function to integral or enumeration
400 // type exists (12.3). If the condition is of class type, the condition is
401 // converted by calling that conversion function, and the result of the
402 // conversion is used in place of the original condition for the remainder
403 // of this section. Integral promotions are performed.
405 // Make sure that the condition expression has a complete type,
406 // otherwise we'll never find any conversions.
407 if (S.RequireCompleteType(SwitchLoc, CondType,
408 PDiag(diag::err_switch_incomplete_class_type)
409 << CondExpr->getSourceRange()))
412 llvm::SmallVector<CXXConversionDecl *, 4> ViableConversions;
413 llvm::SmallVector<CXXConversionDecl *, 4> ExplicitConversions;
414 if (const RecordType *RecordTy = CondType->getAs<RecordType>()) {
415 const UnresolvedSet *Conversions
416 = cast<CXXRecordDecl>(RecordTy->getDecl())
417 ->getVisibleConversionFunctions();
418 for (UnresolvedSet::iterator I = Conversions->begin(),
419 E = Conversions->end(); I != E; ++I) {
420 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(*I))
421 if (Conversion->getConversionType().getNonReferenceType()
422 ->isIntegralType()) {
423 if (Conversion->isExplicit())
424 ExplicitConversions.push_back(Conversion);
426 ViableConversions.push_back(Conversion);
430 switch (ViableConversions.size()) {
432 if (ExplicitConversions.size() == 1) {
433 // The user probably meant to invoke the given explicit
434 // conversion; use it.
436 = ExplicitConversions[0]->getConversionType()
437 .getNonReferenceType();
439 ConvTy.getAsStringInternal(TypeStr, S.Context.PrintingPolicy);
441 S.Diag(SwitchLoc, diag::err_switch_explicit_conversion)
442 << CondType << ConvTy << CondExpr->getSourceRange()
443 << CodeModificationHint::CreateInsertion(CondExpr->getLocStart(),
444 "static_cast<" + TypeStr + ">(")
445 << CodeModificationHint::CreateInsertion(
446 S.PP.getLocForEndOfToken(CondExpr->getLocEnd()),
448 S.Diag(ExplicitConversions[0]->getLocation(),
449 diag::note_switch_conversion)
450 << ConvTy->isEnumeralType() << ConvTy;
452 // If we aren't in a SFINAE context, build a call to the
453 // explicit conversion function.
454 if (S.isSFINAEContext())
457 CondExpr = S.BuildCXXMemberCallExpr(CondExpr, ExplicitConversions[0]);
460 // We'll complain below about a non-integral condition type.
464 // Apply this conversion.
465 CondExpr = S.BuildCXXMemberCallExpr(CondExpr, ViableConversions[0]);
469 S.Diag(SwitchLoc, diag::err_switch_multiple_conversions)
470 << CondType << CondExpr->getSourceRange();
471 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
473 = ViableConversions[I]->getConversionType().getNonReferenceType();
474 S.Diag(ViableConversions[I]->getLocation(),
475 diag::note_switch_conversion)
476 << ConvTy->isEnumeralType() << ConvTy;
485 Action::OwningStmtResult
486 Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch,
488 Stmt *BodyStmt = Body.takeAs<Stmt>();
490 SwitchStmt *SS = getSwitchStack().back();
491 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!");
493 SS->setBody(BodyStmt, SwitchLoc);
494 getSwitchStack().pop_back();
496 if (SS->getCond() == 0) {
497 SS->Destroy(Context);
501 Expr *CondExpr = SS->getCond();
502 QualType CondTypeBeforePromotion =
503 GetTypeBeforeIntegralPromotion(CondExpr);
505 if (getLangOptions().CPlusPlus &&
506 CheckCXXSwitchCondition(*this, SwitchLoc, CondExpr))
509 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr.
510 UsualUnaryConversions(CondExpr);
511 QualType CondType = CondExpr->getType();
512 SS->setCond(CondExpr);
515 // Integral promotions are performed (on the switch condition).
517 // A case value unrepresentable by the original switch condition
518 // type (before the promotion) doesn't make sense, even when it can
519 // be represented by the promoted type. Therefore we need to find
520 // the pre-promotion type of the switch condition.
521 if (!CondExpr->isTypeDependent()) {
522 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1
523 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer)
524 << CondType << CondExpr->getSourceRange();
528 if (CondTypeBeforePromotion->isBooleanType()) {
529 // switch(bool_expr) {...} is often a programmer error, e.g.
530 // switch(n && mask) { ... } // Doh - should be "n & mask".
531 // One can always use an if statement instead of switch(bool_expr).
532 Diag(SwitchLoc, diag::warn_bool_switch_condition)
533 << CondExpr->getSourceRange();
537 // Get the bitwidth of the switched-on value before promotions. We must
538 // convert the integer case values to this width before comparison.
539 bool HasDependentValue
540 = CondExpr->isTypeDependent() || CondExpr->isValueDependent();
542 = HasDependentValue? 0
543 : static_cast<unsigned>(Context.getTypeSize(CondTypeBeforePromotion));
544 bool CondIsSigned = CondTypeBeforePromotion->isSignedIntegerType();
546 // Accumulate all of the case values in a vector so that we can sort them
547 // and detect duplicates. This vector contains the APInt for the case after
548 // it has been converted to the condition type.
549 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy;
552 // Keep track of any GNU case ranges we see. The APSInt is the low value.
553 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges;
555 DefaultStmt *TheDefaultStmt = 0;
557 bool CaseListIsErroneous = false;
559 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue;
560 SC = SC->getNextSwitchCase()) {
562 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) {
563 if (TheDefaultStmt) {
564 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined);
565 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev);
567 // FIXME: Remove the default statement from the switch block so that
568 // we'll return a valid AST. This requires recursing down the AST and
569 // finding it, not something we are set up to do right now. For now,
570 // just lop the entire switch stmt out of the AST.
571 CaseListIsErroneous = true;
576 CaseStmt *CS = cast<CaseStmt>(SC);
578 // We already verified that the expression has a i-c-e value (C99
579 // 6.8.4.2p3) - get that value now.
580 Expr *Lo = CS->getLHS();
582 if (Lo->isTypeDependent() || Lo->isValueDependent()) {
583 HasDependentValue = true;
587 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context);
589 // Convert the value to the same width/sign as the condition.
590 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned,
591 CS->getLHS()->getLocStart(),
592 diag::warn_case_value_overflow);
594 // If the LHS is not the same type as the condition, insert an implicit
596 ImpCastExprToType(Lo, CondType, CastExpr::CK_IntegralCast);
599 // If this is a case range, remember it in CaseRanges, otherwise CaseVals.
601 if (CS->getRHS()->isTypeDependent() ||
602 CS->getRHS()->isValueDependent()) {
603 HasDependentValue = true;
606 CaseRanges.push_back(std::make_pair(LoVal, CS));
608 CaseVals.push_back(std::make_pair(LoVal, CS));
612 if (!HasDependentValue) {
613 // Sort all the scalar case values so we can easily detect duplicates.
614 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals);
616 if (!CaseVals.empty()) {
617 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) {
618 if (CaseVals[i].first == CaseVals[i+1].first) {
619 // If we have a duplicate, report it.
620 Diag(CaseVals[i+1].second->getLHS()->getLocStart(),
621 diag::err_duplicate_case) << CaseVals[i].first.toString(10);
622 Diag(CaseVals[i].second->getLHS()->getLocStart(),
623 diag::note_duplicate_case_prev);
624 // FIXME: We really want to remove the bogus case stmt from the
625 // substmt, but we have no way to do this right now.
626 CaseListIsErroneous = true;
631 // Detect duplicate case ranges, which usually don't exist at all in
633 if (!CaseRanges.empty()) {
634 // Sort all the case ranges by their low value so we can easily detect
635 // overlaps between ranges.
636 std::stable_sort(CaseRanges.begin(), CaseRanges.end());
638 // Scan the ranges, computing the high values and removing empty ranges.
639 std::vector<llvm::APSInt> HiVals;
640 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
641 CaseStmt *CR = CaseRanges[i].second;
642 Expr *Hi = CR->getRHS();
643 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context);
645 // Convert the value to the same width/sign as the condition.
646 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned,
647 CR->getRHS()->getLocStart(),
648 diag::warn_case_value_overflow);
650 // If the LHS is not the same type as the condition, insert an implicit
652 ImpCastExprToType(Hi, CondType, CastExpr::CK_IntegralCast);
655 // If the low value is bigger than the high value, the case is empty.
656 if (CaseRanges[i].first > HiVal) {
657 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range)
658 << SourceRange(CR->getLHS()->getLocStart(),
659 CR->getRHS()->getLocEnd());
660 CaseRanges.erase(CaseRanges.begin()+i);
664 HiVals.push_back(HiVal);
667 // Rescan the ranges, looking for overlap with singleton values and other
668 // ranges. Since the range list is sorted, we only need to compare case
669 // ranges with their neighbors.
670 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) {
671 llvm::APSInt &CRLo = CaseRanges[i].first;
672 llvm::APSInt &CRHi = HiVals[i];
673 CaseStmt *CR = CaseRanges[i].second;
675 // Check to see whether the case range overlaps with any
677 CaseStmt *OverlapStmt = 0;
678 llvm::APSInt OverlapVal(32);
680 // Find the smallest value >= the lower bound. If I is in the
681 // case range, then we have overlap.
682 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(),
683 CaseVals.end(), CRLo,
684 CaseCompareFunctor());
685 if (I != CaseVals.end() && I->first < CRHi) {
686 OverlapVal = I->first; // Found overlap with scalar.
687 OverlapStmt = I->second;
690 // Find the smallest value bigger than the upper bound.
691 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor());
692 if (I != CaseVals.begin() && (I-1)->first >= CRLo) {
693 OverlapVal = (I-1)->first; // Found overlap with scalar.
694 OverlapStmt = (I-1)->second;
697 // Check to see if this case stmt overlaps with the subsequent
699 if (i && CRLo <= HiVals[i-1]) {
700 OverlapVal = HiVals[i-1]; // Found overlap with range.
701 OverlapStmt = CaseRanges[i-1].second;
705 // If we have a duplicate, report it.
706 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case)
707 << OverlapVal.toString(10);
708 Diag(OverlapStmt->getLHS()->getLocStart(),
709 diag::note_duplicate_case_prev);
710 // FIXME: We really want to remove the bogus case stmt from the
711 // substmt, but we have no way to do this right now.
712 CaseListIsErroneous = true;
718 // FIXME: If the case list was broken is some way, we don't have a good system
719 // to patch it up. Instead, just return the whole substmt as broken.
720 if (CaseListIsErroneous)
727 Action::OwningStmtResult
728 Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond,
729 DeclPtrTy CondVar, StmtArg Body) {
730 OwningExprResult CondResult(Cond.release());
732 VarDecl *ConditionVar = 0;
734 ConditionVar = CondVar.getAs<VarDecl>();
735 CondResult = CheckConditionVariable(ConditionVar);
736 if (CondResult.isInvalid())
739 Expr *ConditionExpr = CondResult.takeAs<Expr>();
743 if (CheckBooleanCondition(ConditionExpr, WhileLoc)) {
744 CondResult = ConditionExpr;
748 Stmt *bodyStmt = Body.takeAs<Stmt>();
749 DiagnoseUnusedExprResult(bodyStmt);
751 CondResult.release();
752 return Owned(new (Context) WhileStmt(ConditionVar, ConditionExpr, bodyStmt,
756 Action::OwningStmtResult
757 Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body,
758 SourceLocation WhileLoc, SourceLocation CondLParen,
759 ExprArg Cond, SourceLocation CondRParen) {
760 Expr *condExpr = Cond.takeAs<Expr>();
761 assert(condExpr && "ActOnDoStmt(): missing expression");
763 if (CheckBooleanCondition(condExpr, DoLoc)) {
768 Stmt *bodyStmt = Body.takeAs<Stmt>();
769 DiagnoseUnusedExprResult(bodyStmt);
772 return Owned(new (Context) DoStmt(bodyStmt, condExpr, DoLoc,
773 WhileLoc, CondRParen));
776 Action::OwningStmtResult
777 Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc,
778 StmtArg first, FullExprArg second, DeclPtrTy secondVar,
780 SourceLocation RParenLoc, StmtArg body) {
781 Stmt *First = static_cast<Stmt*>(first.get());
783 if (!getLangOptions().CPlusPlus) {
784 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) {
785 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
786 // declare identifiers for objects having storage class 'auto' or
788 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end();
790 VarDecl *VD = dyn_cast<VarDecl>(*DI);
791 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage())
794 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for);
795 // FIXME: mark decl erroneous!
800 OwningExprResult SecondResult(second.release());
801 VarDecl *ConditionVar = 0;
802 if (secondVar.get()) {
803 ConditionVar = secondVar.getAs<VarDecl>();
804 SecondResult = CheckConditionVariable(ConditionVar);
805 if (SecondResult.isInvalid())
809 Expr *Second = SecondResult.takeAs<Expr>();
810 if (Second && CheckBooleanCondition(Second, ForLoc)) {
811 SecondResult = Second;
815 Expr *Third = third.release().takeAs<Expr>();
816 Stmt *Body = static_cast<Stmt*>(body.get());
818 DiagnoseUnusedExprResult(First);
819 DiagnoseUnusedExprResult(Third);
820 DiagnoseUnusedExprResult(Body);
824 return Owned(new (Context) ForStmt(First, Second, ConditionVar, Third, Body,
825 ForLoc, LParenLoc, RParenLoc));
828 Action::OwningStmtResult
829 Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc,
830 SourceLocation LParenLoc,
831 StmtArg first, ExprArg second,
832 SourceLocation RParenLoc, StmtArg body) {
833 Stmt *First = static_cast<Stmt*>(first.get());
834 Expr *Second = static_cast<Expr*>(second.get());
835 Stmt *Body = static_cast<Stmt*>(body.get());
838 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) {
839 if (!DS->isSingleDecl())
840 return StmtError(Diag((*DS->decl_begin())->getLocation(),
841 diag::err_toomany_element_decls));
843 Decl *D = DS->getSingleDecl();
844 FirstType = cast<ValueDecl>(D)->getType();
845 // C99 6.8.5p3: The declaration part of a 'for' statement shall only
846 // declare identifiers for objects having storage class 'auto' or
848 VarDecl *VD = cast<VarDecl>(D);
849 if (VD->isBlockVarDecl() && !VD->hasLocalStorage())
850 return StmtError(Diag(VD->getLocation(),
851 diag::err_non_variable_decl_in_for));
853 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid)
854 return StmtError(Diag(First->getLocStart(),
855 diag::err_selector_element_not_lvalue)
856 << First->getSourceRange());
858 FirstType = static_cast<Expr*>(First)->getType();
860 if (!FirstType->isObjCObjectPointerType() &&
861 !FirstType->isBlockPointerType())
862 Diag(ForLoc, diag::err_selector_element_type)
863 << FirstType << First->getSourceRange();
866 DefaultFunctionArrayConversion(Second);
867 QualType SecondType = Second->getType();
868 if (!SecondType->isObjCObjectPointerType())
869 Diag(ForLoc, diag::err_collection_expr_type)
870 << SecondType << Second->getSourceRange();
875 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body,
879 Action::OwningStmtResult
880 Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc,
881 IdentifierInfo *LabelII) {
882 // If we are in a block, reject all gotos for now.
884 return StmtError(Diag(GotoLoc, diag::err_goto_in_block));
886 // Look up the record for this label identifier.
887 LabelStmt *&LabelDecl = getLabelMap()[LabelII];
889 // If we haven't seen this label yet, create a forward reference.
891 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0);
893 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc));
896 Action::OwningStmtResult
897 Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc,
899 // Convert operand to void*
900 Expr* E = DestExp.takeAs<Expr>();
901 if (!E->isTypeDependent()) {
902 QualType ETy = E->getType();
903 AssignConvertType ConvTy =
904 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E);
905 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy,
909 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E));
912 Action::OwningStmtResult
913 Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) {
914 Scope *S = CurScope->getContinueParent();
916 // C99 6.8.6.2p1: A break shall appear only in or as a loop body.
917 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop));
920 return Owned(new (Context) ContinueStmt(ContinueLoc));
923 Action::OwningStmtResult
924 Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) {
925 Scope *S = CurScope->getBreakParent();
927 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body.
928 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch));
931 return Owned(new (Context) BreakStmt(BreakLoc));
934 /// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
936 Action::OwningStmtResult
937 Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
938 // If this is the first return we've seen in the block, infer the type of
939 // the block from it.
940 if (CurBlock->ReturnType.isNull()) {
942 // Don't call UsualUnaryConversions(), since we don't want to do
943 // integer promotions here.
944 DefaultFunctionArrayConversion(RetValExp);
945 CurBlock->ReturnType = RetValExp->getType();
946 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) {
947 // We have to remove a 'const' added to copied-in variable which was
948 // part of the implementation spec. and not the actual qualifier for
950 if (CDRE->isConstQualAdded())
951 CurBlock->ReturnType.removeConst();
954 CurBlock->ReturnType = Context.VoidTy;
956 QualType FnRetType = CurBlock->ReturnType;
958 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) {
959 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr)
960 << getCurFunctionOrMethodDecl()->getDeclName();
964 // Otherwise, verify that this result type matches the previous one. We are
965 // pickier with blocks than for normal functions because we don't have GCC
966 // compatibility to worry about here.
967 if (CurBlock->ReturnType->isVoidType()) {
969 Diag(ReturnLoc, diag::err_return_block_has_expr);
970 RetValExp->Destroy(Context);
973 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
977 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr));
979 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
980 // we have a non-void block with an expression, continue checking
982 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
983 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
986 // In C++ the return statement is handled via a copy initialization.
987 // the C version of which boils down to CheckSingleAssignmentConstraints.
988 // FIXME: Leaks RetValExp.
989 if (PerformCopyInitialization(RetValExp, FnRetType, AA_Returning))
992 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
995 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
998 /// IsReturnCopyElidable - Whether returning @p RetExpr from a function that
999 /// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15).
1000 static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType,
1002 QualType ExprType = RetExpr->getType();
1003 // - in a return statement in a function with ...
1004 // ... a class return type ...
1005 if (!RetType->isRecordType())
1007 // ... the same cv-unqualified type as the function return type ...
1008 if (!Ctx.hasSameUnqualifiedType(RetType, ExprType))
1010 // ... the expression is the name of a non-volatile automatic object ...
1011 // We ignore parentheses here.
1012 // FIXME: Is this compliant?
1013 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens());
1016 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
1019 return VD->hasLocalStorage() && !VD->getType()->isReferenceType()
1020 && !VD->getType().isVolatileQualified();
1023 Action::OwningStmtResult
1024 Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) {
1025 Expr *RetValExp = rex.takeAs<Expr>();
1027 return ActOnBlockReturnStmt(ReturnLoc, RetValExp);
1030 if (const FunctionDecl *FD = getCurFunctionDecl()) {
1031 FnRetType = FD->getResultType();
1032 if (FD->hasAttr<NoReturnAttr>())
1033 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr)
1034 << getCurFunctionOrMethodDecl()->getDeclName();
1035 } else if (ObjCMethodDecl *MD = getCurMethodDecl())
1036 FnRetType = MD->getResultType();
1037 else // If we don't have a function/method context, bail.
1040 if (FnRetType->isVoidType()) {
1041 if (RetValExp && !RetValExp->isTypeDependent()) {
1042 // C99 6.8.6.4p1 (ext_ since GCC warns)
1043 unsigned D = diag::ext_return_has_expr;
1044 if (RetValExp->getType()->isVoidType())
1045 D = diag::ext_return_has_void_expr;
1047 // return (some void expression); is legal in C++.
1048 if (D != diag::ext_return_has_void_expr ||
1049 !getLangOptions().CPlusPlus) {
1050 NamedDecl *CurDecl = getCurFunctionOrMethodDecl();
1052 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl)
1053 << RetValExp->getSourceRange();
1056 RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp);
1058 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1061 if (!RetValExp && !FnRetType->isDependentType()) {
1062 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4
1063 // C99 6.8.6.4p1 (ext_ since GCC warns)
1064 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr;
1066 if (FunctionDecl *FD = getCurFunctionDecl())
1067 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/;
1069 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/;
1070 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0));
1073 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) {
1074 // we have a non-void function with an expression, continue checking
1076 // C99 6.8.6.4p3(136): The return statement is not an assignment. The
1077 // overlap restriction of subclause 6.5.16.1 does not apply to the case of
1080 // C++0x 12.8p15: When certain criteria are met, an implementation is
1081 // allowed to omit the copy construction of a class object, [...]
1082 // - in a return statement in a function with a class return type, when
1083 // the expression is the name of a non-volatile automatic object with
1084 // the same cv-unqualified type as the function return type, the copy
1085 // operation can be omitted [...]
1086 // C++0x 12.8p16: When the criteria for elision of a copy operation are met
1087 // and the object to be copied is designated by an lvalue, overload
1088 // resolution to select the constructor for the copy is first performed
1089 // as if the object were designated by an rvalue.
1090 // Note that we only compute Elidable if we're in C++0x, since we don't
1092 bool Elidable = getLangOptions().CPlusPlus0x ?
1093 IsReturnCopyElidable(Context, FnRetType, RetValExp) :
1098 // In C++ the return statement is handled via a copy initialization.
1099 // the C version of which boils down to CheckSingleAssignmentConstraints.
1100 OwningExprResult Res = PerformCopyInitialization(
1101 InitializedEntity::InitializeResult(ReturnLoc,
1105 if (Res.isInvalid()) {
1106 // FIXME: Cleanup temporaries here, anyway?
1110 RetValExp = Res.takeAs<Expr>();
1112 CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
1116 RetValExp = MaybeCreateCXXExprWithTemporaries(RetValExp);
1117 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp));
1120 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
1121 /// ignore "noop" casts in places where an lvalue is required by an inline asm.
1122 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but
1123 /// provide a strong guidance to not use it.
1125 /// This method checks to see if the argument is an acceptable l-value and
1126 /// returns false if it is a case we can handle.
1127 static bool CheckAsmLValue(const Expr *E, Sema &S) {
1128 if (E->isLvalue(S.Context) == Expr::LV_Valid)
1129 return false; // Cool, this is an lvalue.
1131 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we
1132 // are supposed to allow.
1133 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
1134 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) {
1135 if (!S.getLangOptions().HeinousExtensions)
1136 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue)
1137 << E->getSourceRange();
1139 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
1140 << E->getSourceRange();
1141 // Accept, even if we emitted an error diagnostic.
1145 // None of the above, just randomly invalid non-lvalue.
1150 Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc,
1153 unsigned NumOutputs,
1156 MultiExprArg constraints,
1159 MultiExprArg clobbers,
1160 SourceLocation RParenLoc,
1162 unsigned NumClobbers = clobbers.size();
1163 StringLiteral **Constraints =
1164 reinterpret_cast<StringLiteral**>(constraints.get());
1165 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get());
1166 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get());
1167 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get());
1169 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
1171 // The parser verifies that there is a string literal here.
1172 if (AsmString->isWide())
1173 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character)
1174 << AsmString->getSourceRange());
1176 for (unsigned i = 0; i != NumOutputs; i++) {
1177 StringLiteral *Literal = Constraints[i];
1178 if (Literal->isWide())
1179 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1180 << Literal->getSourceRange());
1182 TargetInfo::ConstraintInfo Info(Literal->getStrData(),
1183 Literal->getByteLength(),
1185 if (!Context.Target.validateOutputConstraint(Info))
1186 return StmtError(Diag(Literal->getLocStart(),
1187 diag::err_asm_invalid_output_constraint)
1188 << Info.getConstraintStr());
1190 // Check that the output exprs are valid lvalues.
1191 Expr *OutputExpr = Exprs[i];
1192 if (CheckAsmLValue(OutputExpr, *this)) {
1193 return StmtError(Diag(OutputExpr->getLocStart(),
1194 diag::err_asm_invalid_lvalue_in_output)
1195 << OutputExpr->getSourceRange());
1198 OutputConstraintInfos.push_back(Info);
1201 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
1203 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
1204 StringLiteral *Literal = Constraints[i];
1205 if (Literal->isWide())
1206 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1207 << Literal->getSourceRange());
1209 TargetInfo::ConstraintInfo Info(Literal->getStrData(),
1210 Literal->getByteLength(),
1212 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(),
1213 NumOutputs, Info)) {
1214 return StmtError(Diag(Literal->getLocStart(),
1215 diag::err_asm_invalid_input_constraint)
1216 << Info.getConstraintStr());
1219 Expr *InputExpr = Exprs[i];
1221 // Only allow void types for memory constraints.
1222 if (Info.allowsMemory() && !Info.allowsRegister()) {
1223 if (CheckAsmLValue(InputExpr, *this))
1224 return StmtError(Diag(InputExpr->getLocStart(),
1225 diag::err_asm_invalid_lvalue_in_input)
1226 << Info.getConstraintStr()
1227 << InputExpr->getSourceRange());
1230 if (Info.allowsRegister()) {
1231 if (InputExpr->getType()->isVoidType()) {
1232 return StmtError(Diag(InputExpr->getLocStart(),
1233 diag::err_asm_invalid_type_in_input)
1234 << InputExpr->getType() << Info.getConstraintStr()
1235 << InputExpr->getSourceRange());
1239 DefaultFunctionArrayConversion(Exprs[i]);
1241 InputConstraintInfos.push_back(Info);
1244 // Check that the clobbers are valid.
1245 for (unsigned i = 0; i != NumClobbers; i++) {
1246 StringLiteral *Literal = Clobbers[i];
1247 if (Literal->isWide())
1248 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character)
1249 << Literal->getSourceRange());
1251 std::string Clobber(Literal->getStrData(),
1252 Literal->getStrData() +
1253 Literal->getByteLength());
1255 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str()))
1256 return StmtError(Diag(Literal->getLocStart(),
1257 diag::err_asm_unknown_register_name) << Clobber);
1260 constraints.release();
1262 asmString.release();
1265 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, MSAsm, NumOutputs,
1266 NumInputs, Names, Constraints, Exprs, AsmString,
1267 NumClobbers, Clobbers, RParenLoc);
1268 // Validate the asm string, ensuring it makes sense given the operands we
1270 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces;
1272 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
1273 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
1274 << AsmString->getSourceRange();
1279 // Validate tied input operands for type mismatches.
1280 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
1281 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
1283 // If this is a tied constraint, verify that the output and input have
1284 // either exactly the same type, or that they are int/ptr operands with the
1285 // same size (int/long, int*/long, are ok etc).
1286 if (!Info.hasTiedOperand()) continue;
1288 unsigned TiedTo = Info.getTiedOperand();
1289 Expr *OutputExpr = Exprs[TiedTo];
1290 Expr *InputExpr = Exprs[i+NumOutputs];
1291 QualType InTy = InputExpr->getType();
1292 QualType OutTy = OutputExpr->getType();
1293 if (Context.hasSameType(InTy, OutTy))
1294 continue; // All types can be tied to themselves.
1296 // Int/ptr operands have some special cases that we allow.
1297 if ((OutTy->isIntegerType() || OutTy->isPointerType()) &&
1298 (InTy->isIntegerType() || InTy->isPointerType())) {
1300 // They are ok if they are the same size. Tying void* to int is ok if
1301 // they are the same size, for example. This also allows tying void* to
1303 uint64_t OutSize = Context.getTypeSize(OutTy);
1304 uint64_t InSize = Context.getTypeSize(InTy);
1305 if (OutSize == InSize)
1308 // If the smaller input/output operand is not mentioned in the asm string,
1309 // then we can promote it and the asm string won't notice. Check this
1311 bool SmallerValueMentioned = false;
1312 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) {
1313 AsmStmt::AsmStringPiece &Piece = Pieces[p];
1314 if (!Piece.isOperand()) continue;
1316 // If this is a reference to the input and if the input was the smaller
1317 // one, then we have to reject this asm.
1318 if (Piece.getOperandNo() == i+NumOutputs) {
1319 if (InSize < OutSize) {
1320 SmallerValueMentioned = true;
1325 // If this is a reference to the input and if the input was the smaller
1326 // one, then we have to reject this asm.
1327 if (Piece.getOperandNo() == TiedTo) {
1328 if (InSize > OutSize) {
1329 SmallerValueMentioned = true;
1335 // If the smaller value wasn't mentioned in the asm string, and if the
1336 // output was a register, just extend the shorter one to the size of the
1338 if (!SmallerValueMentioned &&
1339 OutputConstraintInfos[TiedTo].allowsRegister())
1343 Diag(InputExpr->getLocStart(),
1344 diag::err_asm_tying_incompatible_types)
1345 << InTy << OutTy << OutputExpr->getSourceRange()
1346 << InputExpr->getSourceRange();
1354 Action::OwningStmtResult
1355 Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc,
1356 SourceLocation RParen, DeclPtrTy Parm,
1357 StmtArg Body, StmtArg catchList) {
1358 Stmt *CatchList = catchList.takeAs<Stmt>();
1359 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>());
1361 // PVD == 0 implies @catch(...).
1363 // If we already know the decl is invalid, reject it.
1364 if (PVD->isInvalidDecl())
1367 if (!PVD->getType()->isObjCObjectPointerType())
1368 return StmtError(Diag(PVD->getLocation(),
1369 diag::err_catch_param_not_objc_type));
1370 if (PVD->getType()->isObjCQualifiedIdType())
1371 return StmtError(Diag(PVD->getLocation(),
1372 diag::err_illegal_qualifiers_on_catch_parm));
1375 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen,
1376 PVD, Body.takeAs<Stmt>(), CatchList);
1377 return Owned(CatchList ? CatchList : CS);
1380 Action::OwningStmtResult
1381 Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) {
1382 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc,
1383 static_cast<Stmt*>(Body.release())));
1386 Action::OwningStmtResult
1387 Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc,
1388 StmtArg Try, StmtArg Catch, StmtArg Finally) {
1389 CurFunctionNeedsScopeChecking = true;
1390 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(),
1391 Catch.takeAs<Stmt>(),
1392 Finally.takeAs<Stmt>()));
1395 Action::OwningStmtResult
1396 Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) {
1397 Expr *ThrowExpr = expr.takeAs<Expr>();
1399 // @throw without an expression designates a rethrow (which much occur
1400 // in the context of an @catch clause).
1401 Scope *AtCatchParent = CurScope;
1402 while (AtCatchParent && !AtCatchParent->isAtCatchScope())
1403 AtCatchParent = AtCatchParent->getParent();
1405 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch));
1407 QualType ThrowType = ThrowExpr->getType();
1408 // Make sure the expression type is an ObjC pointer or "void *".
1409 if (!ThrowType->isObjCObjectPointerType()) {
1410 const PointerType *PT = ThrowType->getAs<PointerType>();
1411 if (!PT || !PT->getPointeeType()->isVoidType())
1412 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object)
1413 << ThrowExpr->getType() << ThrowExpr->getSourceRange());
1416 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr));
1419 Action::OwningStmtResult
1420 Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr,
1421 StmtArg SynchBody) {
1422 CurFunctionNeedsScopeChecking = true;
1424 // Make sure the expression type is an ObjC pointer or "void *".
1425 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get());
1426 if (!SyncExpr->getType()->isObjCObjectPointerType()) {
1427 const PointerType *PT = SyncExpr->getType()->getAs<PointerType>();
1428 if (!PT || !PT->getPointeeType()->isVoidType())
1429 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object)
1430 << SyncExpr->getType() << SyncExpr->getSourceRange());
1433 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc,
1434 SynchExpr.takeAs<Stmt>(),
1435 SynchBody.takeAs<Stmt>()));
1438 /// ActOnCXXCatchBlock - Takes an exception declaration and a handler block
1439 /// and creates a proper catch handler from them.
1440 Action::OwningStmtResult
1441 Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl,
1442 StmtArg HandlerBlock) {
1443 // There's nothing to test that ActOnExceptionDecl didn't already test.
1444 return Owned(new (Context) CXXCatchStmt(CatchLoc,
1445 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()),
1446 HandlerBlock.takeAs<Stmt>()));
1449 class TypeWithHandler {
1453 TypeWithHandler(const QualType &type, CXXCatchStmt *statement)
1454 : t(type), stmt(statement) {}
1456 // An arbitrary order is fine as long as it places identical
1457 // types next to each other.
1458 bool operator<(const TypeWithHandler &y) const {
1459 if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr())
1461 if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr())
1464 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc();
1467 bool operator==(const TypeWithHandler& other) const {
1468 return t == other.t;
1471 QualType getQualType() const { return t; }
1472 CXXCatchStmt *getCatchStmt() const { return stmt; }
1473 SourceLocation getTypeSpecStartLoc() const {
1474 return stmt->getExceptionDecl()->getTypeSpecStartLoc();
1478 /// ActOnCXXTryBlock - Takes a try compound-statement and a number of
1479 /// handlers and creates a try statement from them.
1480 Action::OwningStmtResult
1481 Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock,
1482 MultiStmtArg RawHandlers) {
1483 unsigned NumHandlers = RawHandlers.size();
1484 assert(NumHandlers > 0 &&
1485 "The parser shouldn't call this if there are no handlers.");
1486 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get());
1488 llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers;
1490 for (unsigned i = 0; i < NumHandlers; ++i) {
1491 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]);
1492 if (!Handler->getExceptionDecl()) {
1493 if (i < NumHandlers - 1)
1494 return StmtError(Diag(Handler->getLocStart(),
1495 diag::err_early_catch_all));
1500 const QualType CaughtType = Handler->getCaughtType();
1501 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType);
1502 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler));
1505 // Detect handlers for the same type as an earlier one.
1506 if (NumHandlers > 1) {
1507 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end());
1509 TypeWithHandler prev = TypesWithHandlers[0];
1510 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) {
1511 TypeWithHandler curr = TypesWithHandlers[i];
1514 Diag(curr.getTypeSpecStartLoc(),
1515 diag::warn_exception_caught_by_earlier_handler)
1516 << curr.getCatchStmt()->getCaughtType().getAsString();
1517 Diag(prev.getTypeSpecStartLoc(),
1518 diag::note_previous_exception_handler)
1519 << prev.getCatchStmt()->getCaughtType().getAsString();
1526 // FIXME: We should detect handlers that cannot catch anything because an
1527 // earlier handler catches a superclass. Need to find a method that is not
1528 // quadratic for this.
1529 // Neither of these are explicitly forbidden, but every compiler detects them
1532 CurFunctionNeedsScopeChecking = true;
1533 RawHandlers.release();
1534 return Owned(new (Context) CXXTryStmt(TryLoc,
1535 static_cast<Stmt*>(TryBlock.release()),
1536 Handlers, NumHandlers));