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Diffstat (limited to 'lib/Sema/SemaStmt.cpp')
| -rw-r--r-- | lib/Sema/SemaStmt.cpp | 1266 |
1 files changed, 1266 insertions, 0 deletions
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp new file mode 100644 index 0000000..15262e9 --- /dev/null +++ b/lib/Sema/SemaStmt.cpp @@ -0,0 +1,1266 @@ +//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements semantic analysis for statements. +// +//===----------------------------------------------------------------------===// + +#include "Sema.h" +#include "clang/AST/APValue.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/Expr.h" +#include "clang/AST/StmtObjC.h" +#include "clang/AST/StmtCXX.h" +#include "clang/Basic/TargetInfo.h" +using namespace clang; + +Sema::OwningStmtResult Sema::ActOnExprStmt(FullExprArg expr) { + Expr *E = expr->takeAs<Expr>(); + assert(E && "ActOnExprStmt(): missing expression"); + + // C99 6.8.3p2: The expression in an expression statement is evaluated as a + // void expression for its side effects. Conversion to void allows any + // operand, even incomplete types. + + // Same thing in for stmt first clause (when expr) and third clause. + return Owned(static_cast<Stmt*>(E)); +} + + +Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { + return Owned(new (Context) NullStmt(SemiLoc)); +} + +Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, + SourceLocation StartLoc, + SourceLocation EndLoc) { + DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); + + // If we have an invalid decl, just return an error. + if (DG.isNull()) return StmtError(); + + return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); +} + +Action::OwningStmtResult +Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, + MultiStmtArg elts, bool isStmtExpr) { + unsigned NumElts = elts.size(); + Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); + // If we're in C89 mode, check that we don't have any decls after stmts. If + // so, emit an extension diagnostic. + if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { + // Note that __extension__ can be around a decl. + unsigned i = 0; + // Skip over all declarations. + for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) + /*empty*/; + + // We found the end of the list or a statement. Scan for another declstmt. + for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) + /*empty*/; + + if (i != NumElts) { + Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); + Diag(D->getLocation(), diag::ext_mixed_decls_code); + } + } + // Warn about unused expressions in statements. + for (unsigned i = 0; i != NumElts; ++i) { + Expr *E = dyn_cast<Expr>(Elts[i]); + if (!E) continue; + + // Warn about expressions with unused results if they are non-void and if + // this not the last stmt in a stmt expr. + if (E->getType()->isVoidType() || (isStmtExpr && i == NumElts-1)) + continue; + + SourceLocation Loc; + SourceRange R1, R2; + if (!E->isUnusedResultAWarning(Loc, R1, R2)) + continue; + + Diag(Loc, diag::warn_unused_expr) << R1 << R2; + } + + return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); +} + +Action::OwningStmtResult +Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval, + SourceLocation DotDotDotLoc, ExprArg rhsval, + SourceLocation ColonLoc) { + assert((lhsval.get() != 0) && "missing expression in case statement"); + + // C99 6.8.4.2p3: The expression shall be an integer constant. + // However, GCC allows any evaluatable integer expression. + Expr *LHSVal = static_cast<Expr*>(lhsval.get()); + if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && + VerifyIntegerConstantExpression(LHSVal)) + return StmtError(); + + // GCC extension: The expression shall be an integer constant. + + Expr *RHSVal = static_cast<Expr*>(rhsval.get()); + if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && + VerifyIntegerConstantExpression(RHSVal)) { + RHSVal = 0; // Recover by just forgetting about it. + rhsval = 0; + } + + if (getSwitchStack().empty()) { + Diag(CaseLoc, diag::err_case_not_in_switch); + return StmtError(); + } + + // Only now release the smart pointers. + lhsval.release(); + rhsval.release(); + CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, + ColonLoc); + getSwitchStack().back()->addSwitchCase(CS); + return Owned(CS); +} + +/// ActOnCaseStmtBody - This installs a statement as the body of a case. +void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) { + CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); + Stmt *SubStmt = subStmt.takeAs<Stmt>(); + CS->setSubStmt(SubStmt); +} + +Action::OwningStmtResult +Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, + StmtArg subStmt, Scope *CurScope) { + Stmt *SubStmt = subStmt.takeAs<Stmt>(); + + if (getSwitchStack().empty()) { + Diag(DefaultLoc, diag::err_default_not_in_switch); + return Owned(SubStmt); + } + + DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); + getSwitchStack().back()->addSwitchCase(DS); + return Owned(DS); +} + +Action::OwningStmtResult +Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, + SourceLocation ColonLoc, StmtArg subStmt) { + Stmt *SubStmt = subStmt.takeAs<Stmt>(); + // Look up the record for this label identifier. + LabelStmt *&LabelDecl = getLabelMap()[II]; + + // If not forward referenced or defined already, just create a new LabelStmt. + if (LabelDecl == 0) + return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt)); + + assert(LabelDecl->getID() == II && "Label mismatch!"); + + // Otherwise, this label was either forward reference or multiply defined. If + // multiply defined, reject it now. + if (LabelDecl->getSubStmt()) { + Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); + Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); + return Owned(SubStmt); + } + + // Otherwise, this label was forward declared, and we just found its real + // definition. Fill in the forward definition and return it. + LabelDecl->setIdentLoc(IdentLoc); + LabelDecl->setSubStmt(SubStmt); + return Owned(LabelDecl); +} + +Action::OwningStmtResult +Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, + StmtArg ThenVal, SourceLocation ElseLoc, + StmtArg ElseVal) { + OwningExprResult CondResult(CondVal.release()); + + Expr *condExpr = CondResult.takeAs<Expr>(); + + assert(condExpr && "ActOnIfStmt(): missing expression"); + + if (!condExpr->isTypeDependent()) { + DefaultFunctionArrayConversion(condExpr); + // Take ownership again until we're past the error checking. + CondResult = condExpr; + QualType condType = condExpr->getType(); + + if (getLangOptions().CPlusPlus) { + if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 + return StmtError(); + } else if (!condType->isScalarType()) // C99 6.8.4.1p1 + return StmtError(Diag(IfLoc, + diag::err_typecheck_statement_requires_scalar) + << condType << condExpr->getSourceRange()); + } + + Stmt *thenStmt = ThenVal.takeAs<Stmt>(); + + // Warn if the if block has a null body without an else value. + // this helps prevent bugs due to typos, such as + // if (condition); + // do_stuff(); + if (!ElseVal.get()) { + if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) + Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); + } + + CondResult.release(); + return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, + ElseLoc, ElseVal.takeAs<Stmt>())); +} + +Action::OwningStmtResult +Sema::ActOnStartOfSwitchStmt(ExprArg cond) { + Expr *Cond = cond.takeAs<Expr>(); + + if (getLangOptions().CPlusPlus) { + // C++ 6.4.2.p2: + // The condition shall be of integral type, enumeration type, or of a class + // type for which a single conversion function to integral or enumeration + // type exists (12.3). If the condition is of class type, the condition is + // converted by calling that conversion function, and the result of the + // conversion is used in place of the original condition for the remainder + // of this section. Integral promotions are performed. + if (!Cond->isTypeDependent()) { + QualType Ty = Cond->getType(); + + // FIXME: Handle class types. + + // If the type is wrong a diagnostic will be emitted later at + // ActOnFinishSwitchStmt. + if (Ty->isIntegralType() || Ty->isEnumeralType()) { + // Integral promotions are performed. + // FIXME: Integral promotions for C++ are not complete. + UsualUnaryConversions(Cond); + } + } + } else { + // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. + UsualUnaryConversions(Cond); + } + + SwitchStmt *SS = new (Context) SwitchStmt(Cond); + getSwitchStack().push_back(SS); + return Owned(SS); +} + +/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have +/// the specified width and sign. If an overflow occurs, detect it and emit +/// the specified diagnostic. +void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, + unsigned NewWidth, bool NewSign, + SourceLocation Loc, + unsigned DiagID) { + // Perform a conversion to the promoted condition type if needed. + if (NewWidth > Val.getBitWidth()) { + // If this is an extension, just do it. + llvm::APSInt OldVal(Val); + Val.extend(NewWidth); + + // If the input was signed and negative and the output is unsigned, + // warn. + if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) + Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); + + Val.setIsSigned(NewSign); + } else if (NewWidth < Val.getBitWidth()) { + // If this is a truncation, check for overflow. + llvm::APSInt ConvVal(Val); + ConvVal.trunc(NewWidth); + ConvVal.setIsSigned(NewSign); + ConvVal.extend(Val.getBitWidth()); + ConvVal.setIsSigned(Val.isSigned()); + if (ConvVal != Val) + Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); + + // Regardless of whether a diagnostic was emitted, really do the + // truncation. + Val.trunc(NewWidth); + Val.setIsSigned(NewSign); + } else if (NewSign != Val.isSigned()) { + // Convert the sign to match the sign of the condition. This can cause + // overflow as well: unsigned(INTMIN) + llvm::APSInt OldVal(Val); + Val.setIsSigned(NewSign); + + if (Val.isNegative()) // Sign bit changes meaning. + Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); + } +} + +namespace { + struct CaseCompareFunctor { + bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, + const llvm::APSInt &RHS) { + return LHS.first < RHS; + } + bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, + const std::pair<llvm::APSInt, CaseStmt*> &RHS) { + return LHS.first < RHS.first; + } + bool operator()(const llvm::APSInt &LHS, + const std::pair<llvm::APSInt, CaseStmt*> &RHS) { + return LHS < RHS.first; + } + }; +} + +/// CmpCaseVals - Comparison predicate for sorting case values. +/// +static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, + const std::pair<llvm::APSInt, CaseStmt*>& rhs) { + if (lhs.first < rhs.first) + return true; + + if (lhs.first == rhs.first && + lhs.second->getCaseLoc().getRawEncoding() + < rhs.second->getCaseLoc().getRawEncoding()) + return true; + return false; +} + +Action::OwningStmtResult +Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, + StmtArg Body) { + Stmt *BodyStmt = Body.takeAs<Stmt>(); + + SwitchStmt *SS = getSwitchStack().back(); + assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); + + SS->setBody(BodyStmt, SwitchLoc); + getSwitchStack().pop_back(); + + Expr *CondExpr = SS->getCond(); + QualType CondType = CondExpr->getType(); + + if (!CondExpr->isTypeDependent() && + !CondType->isIntegerType()) { // C99 6.8.4.2p1 + Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) + << CondType << CondExpr->getSourceRange(); + return StmtError(); + } + + // Get the bitwidth of the switched-on value before promotions. We must + // convert the integer case values to this width before comparison. + bool HasDependentValue + = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); + unsigned CondWidth + = HasDependentValue? 0 + : static_cast<unsigned>(Context.getTypeSize(CondType)); + bool CondIsSigned = CondType->isSignedIntegerType(); + + // Accumulate all of the case values in a vector so that we can sort them + // and detect duplicates. This vector contains the APInt for the case after + // it has been converted to the condition type. + typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; + CaseValsTy CaseVals; + + // Keep track of any GNU case ranges we see. The APSInt is the low value. + std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; + + DefaultStmt *TheDefaultStmt = 0; + + bool CaseListIsErroneous = false; + + for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; + SC = SC->getNextSwitchCase()) { + + if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { + if (TheDefaultStmt) { + Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); + Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); + + // FIXME: Remove the default statement from the switch block so that + // we'll return a valid AST. This requires recursing down the AST and + // finding it, not something we are set up to do right now. For now, + // just lop the entire switch stmt out of the AST. + CaseListIsErroneous = true; + } + TheDefaultStmt = DS; + + } else { + CaseStmt *CS = cast<CaseStmt>(SC); + + // We already verified that the expression has a i-c-e value (C99 + // 6.8.4.2p3) - get that value now. + Expr *Lo = CS->getLHS(); + + if (Lo->isTypeDependent() || Lo->isValueDependent()) { + HasDependentValue = true; + break; + } + + llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); + + // Convert the value to the same width/sign as the condition. + ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, + CS->getLHS()->getLocStart(), + diag::warn_case_value_overflow); + + // If the LHS is not the same type as the condition, insert an implicit + // cast. + ImpCastExprToType(Lo, CondType); + CS->setLHS(Lo); + + // If this is a case range, remember it in CaseRanges, otherwise CaseVals. + if (CS->getRHS()) { + if (CS->getRHS()->isTypeDependent() || + CS->getRHS()->isValueDependent()) { + HasDependentValue = true; + break; + } + CaseRanges.push_back(std::make_pair(LoVal, CS)); + } else + CaseVals.push_back(std::make_pair(LoVal, CS)); + } + } + + if (!HasDependentValue) { + // Sort all the scalar case values so we can easily detect duplicates. + std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); + + if (!CaseVals.empty()) { + for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { + if (CaseVals[i].first == CaseVals[i+1].first) { + // If we have a duplicate, report it. + Diag(CaseVals[i+1].second->getLHS()->getLocStart(), + diag::err_duplicate_case) << CaseVals[i].first.toString(10); + Diag(CaseVals[i].second->getLHS()->getLocStart(), + diag::note_duplicate_case_prev); + // FIXME: We really want to remove the bogus case stmt from the + // substmt, but we have no way to do this right now. + CaseListIsErroneous = true; + } + } + } + + // Detect duplicate case ranges, which usually don't exist at all in + // the first place. + if (!CaseRanges.empty()) { + // Sort all the case ranges by their low value so we can easily detect + // overlaps between ranges. + std::stable_sort(CaseRanges.begin(), CaseRanges.end()); + + // Scan the ranges, computing the high values and removing empty ranges. + std::vector<llvm::APSInt> HiVals; + for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { + CaseStmt *CR = CaseRanges[i].second; + Expr *Hi = CR->getRHS(); + llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); + + // Convert the value to the same width/sign as the condition. + ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, + CR->getRHS()->getLocStart(), + diag::warn_case_value_overflow); + + // If the LHS is not the same type as the condition, insert an implicit + // cast. + ImpCastExprToType(Hi, CondType); + CR->setRHS(Hi); + + // If the low value is bigger than the high value, the case is empty. + if (CaseRanges[i].first > HiVal) { + Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) + << SourceRange(CR->getLHS()->getLocStart(), + CR->getRHS()->getLocEnd()); + CaseRanges.erase(CaseRanges.begin()+i); + --i, --e; + continue; + } + HiVals.push_back(HiVal); + } + + // Rescan the ranges, looking for overlap with singleton values and other + // ranges. Since the range list is sorted, we only need to compare case + // ranges with their neighbors. + for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { + llvm::APSInt &CRLo = CaseRanges[i].first; + llvm::APSInt &CRHi = HiVals[i]; + CaseStmt *CR = CaseRanges[i].second; + + // Check to see whether the case range overlaps with any + // singleton cases. + CaseStmt *OverlapStmt = 0; + llvm::APSInt OverlapVal(32); + + // Find the smallest value >= the lower bound. If I is in the + // case range, then we have overlap. + CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), + CaseVals.end(), CRLo, + CaseCompareFunctor()); + if (I != CaseVals.end() && I->first < CRHi) { + OverlapVal = I->first; // Found overlap with scalar. + OverlapStmt = I->second; + } + + // Find the smallest value bigger than the upper bound. + I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); + if (I != CaseVals.begin() && (I-1)->first >= CRLo) { + OverlapVal = (I-1)->first; // Found overlap with scalar. + OverlapStmt = (I-1)->second; + } + + // Check to see if this case stmt overlaps with the subsequent + // case range. + if (i && CRLo <= HiVals[i-1]) { + OverlapVal = HiVals[i-1]; // Found overlap with range. + OverlapStmt = CaseRanges[i-1].second; + } + + if (OverlapStmt) { + // If we have a duplicate, report it. + Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) + << OverlapVal.toString(10); + Diag(OverlapStmt->getLHS()->getLocStart(), + diag::note_duplicate_case_prev); + // FIXME: We really want to remove the bogus case stmt from the + // substmt, but we have no way to do this right now. + CaseListIsErroneous = true; + } + } + } + } + + // FIXME: If the case list was broken is some way, we don't have a good system + // to patch it up. Instead, just return the whole substmt as broken. + if (CaseListIsErroneous) + return StmtError(); + + Switch.release(); + return Owned(SS); +} + +Action::OwningStmtResult +Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, StmtArg Body) { + ExprArg CondArg(Cond.release()); + Expr *condExpr = CondArg.takeAs<Expr>(); + assert(condExpr && "ActOnWhileStmt(): missing expression"); + + if (!condExpr->isTypeDependent()) { + DefaultFunctionArrayConversion(condExpr); + CondArg = condExpr; + QualType condType = condExpr->getType(); + + if (getLangOptions().CPlusPlus) { + if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 + return StmtError(); + } else if (!condType->isScalarType()) // C99 6.8.5p2 + return StmtError(Diag(WhileLoc, + diag::err_typecheck_statement_requires_scalar) + << condType << condExpr->getSourceRange()); + } + + CondArg.release(); + return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), + WhileLoc)); +} + +Action::OwningStmtResult +Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, + SourceLocation WhileLoc, ExprArg Cond) { + Expr *condExpr = Cond.takeAs<Expr>(); + assert(condExpr && "ActOnDoStmt(): missing expression"); + + if (!condExpr->isTypeDependent()) { + DefaultFunctionArrayConversion(condExpr); + Cond = condExpr; + QualType condType = condExpr->getType(); + + if (getLangOptions().CPlusPlus) { + if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 + return StmtError(); + } else if (!condType->isScalarType()) // C99 6.8.5p2 + return StmtError(Diag(DoLoc, + diag::err_typecheck_statement_requires_scalar) + << condType << condExpr->getSourceRange()); + } + + Cond.release(); + return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, + WhileLoc)); +} + +Action::OwningStmtResult +Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, + StmtArg first, ExprArg second, ExprArg third, + SourceLocation RParenLoc, StmtArg body) { + Stmt *First = static_cast<Stmt*>(first.get()); + Expr *Second = static_cast<Expr*>(second.get()); + Expr *Third = static_cast<Expr*>(third.get()); + Stmt *Body = static_cast<Stmt*>(body.get()); + + if (!getLangOptions().CPlusPlus) { + if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { + // C99 6.8.5p3: The declaration part of a 'for' statement shall only + // declare identifiers for objects having storage class 'auto' or + // 'register'. + for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); + DI!=DE; ++DI) { + VarDecl *VD = dyn_cast<VarDecl>(*DI); + if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) + VD = 0; + if (VD == 0) + Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); + // FIXME: mark decl erroneous! + } + } + } + if (Second && !Second->isTypeDependent()) { + DefaultFunctionArrayConversion(Second); + QualType SecondType = Second->getType(); + + if (getLangOptions().CPlusPlus) { + if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 + return StmtError(); + } else if (!SecondType->isScalarType()) // C99 6.8.5p2 + return StmtError(Diag(ForLoc, + diag::err_typecheck_statement_requires_scalar) + << SecondType << Second->getSourceRange()); + } + first.release(); + second.release(); + third.release(); + body.release(); + return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, + LParenLoc, RParenLoc)); +} + +Action::OwningStmtResult +Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, + SourceLocation LParenLoc, + StmtArg first, ExprArg second, + SourceLocation RParenLoc, StmtArg body) { + Stmt *First = static_cast<Stmt*>(first.get()); + Expr *Second = static_cast<Expr*>(second.get()); + Stmt *Body = static_cast<Stmt*>(body.get()); + if (First) { + QualType FirstType; + if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { + if (!DS->isSingleDecl()) + return StmtError(Diag((*DS->decl_begin())->getLocation(), + diag::err_toomany_element_decls)); + + Decl *D = DS->getSingleDecl(); + FirstType = cast<ValueDecl>(D)->getType(); + // C99 6.8.5p3: The declaration part of a 'for' statement shall only + // declare identifiers for objects having storage class 'auto' or + // 'register'. + VarDecl *VD = cast<VarDecl>(D); + if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) + return StmtError(Diag(VD->getLocation(), + diag::err_non_variable_decl_in_for)); + } else { + if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) + return StmtError(Diag(First->getLocStart(), + diag::err_selector_element_not_lvalue) + << First->getSourceRange()); + + FirstType = static_cast<Expr*>(First)->getType(); + } + if (!Context.isObjCObjectPointerType(FirstType)) + Diag(ForLoc, diag::err_selector_element_type) + << FirstType << First->getSourceRange(); + } + if (Second) { + DefaultFunctionArrayConversion(Second); + QualType SecondType = Second->getType(); + if (!Context.isObjCObjectPointerType(SecondType)) + Diag(ForLoc, diag::err_collection_expr_type) + << SecondType << Second->getSourceRange(); + } + first.release(); + second.release(); + body.release(); + return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, + ForLoc, RParenLoc)); +} + +Action::OwningStmtResult +Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, + IdentifierInfo *LabelII) { + // If we are in a block, reject all gotos for now. + if (CurBlock) + return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); + + // Look up the record for this label identifier. + LabelStmt *&LabelDecl = getLabelMap()[LabelII]; + + // If we haven't seen this label yet, create a forward reference. + if (LabelDecl == 0) + LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); + + return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); +} + +Action::OwningStmtResult +Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, + ExprArg DestExp) { + // Convert operand to void* + Expr* E = DestExp.takeAs<Expr>(); + if (!E->isTypeDependent()) { + QualType ETy = E->getType(); + AssignConvertType ConvTy = + CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); + if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, + E, "passing")) + return StmtError(); + } + return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); +} + +Action::OwningStmtResult +Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { + Scope *S = CurScope->getContinueParent(); + if (!S) { + // C99 6.8.6.2p1: A break shall appear only in or as a loop body. + return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); + } + + return Owned(new (Context) ContinueStmt(ContinueLoc)); +} + +Action::OwningStmtResult +Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { + Scope *S = CurScope->getBreakParent(); + if (!S) { + // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. + return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); + } + + return Owned(new (Context) BreakStmt(BreakLoc)); +} + +/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. +/// +Action::OwningStmtResult +Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { + // If this is the first return we've seen in the block, infer the type of + // the block from it. + if (CurBlock->ReturnType == 0) { + if (RetValExp) { + // Don't call UsualUnaryConversions(), since we don't want to do + // integer promotions here. + DefaultFunctionArrayConversion(RetValExp); + CurBlock->ReturnType = RetValExp->getType().getTypePtr(); + } else + CurBlock->ReturnType = Context.VoidTy.getTypePtr(); + } + QualType FnRetType = QualType(CurBlock->ReturnType, 0); + + if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { + Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) + << getCurFunctionOrMethodDecl()->getDeclName(); + return StmtError(); + } + + // Otherwise, verify that this result type matches the previous one. We are + // pickier with blocks than for normal functions because we don't have GCC + // compatibility to worry about here. + if (CurBlock->ReturnType->isVoidType()) { + if (RetValExp) { + Diag(ReturnLoc, diag::err_return_block_has_expr); + RetValExp->Destroy(Context); + RetValExp = 0; + } + return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); + } + + if (!RetValExp) + return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); + + if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { + // we have a non-void block with an expression, continue checking + QualType RetValType = RetValExp->getType(); + + // C99 6.8.6.4p3(136): The return statement is not an assignment. The + // overlap restriction of subclause 6.5.16.1 does not apply to the case of + // function return. + + // In C++ the return statement is handled via a copy initialization. + // the C version of which boils down to CheckSingleAssignmentConstraints. + // FIXME: Leaks RetValExp. + if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) + return StmtError(); + + if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); + } + + return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); +} + +/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that +/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). +static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, + Expr *RetExpr) { + QualType ExprType = RetExpr->getType(); + // - in a return statement in a function with ... + // ... a class return type ... + if (!RetType->isRecordType()) + return false; + // ... the same cv-unqualified type as the function return type ... + if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != + Ctx.getCanonicalType(ExprType).getUnqualifiedType()) + return false; + // ... the expression is the name of a non-volatile automatic object ... + // We ignore parentheses here. + // FIXME: Is this compliant? + const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); + if (!DR) + return false; + const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); + if (!VD) + return false; + return VD->hasLocalStorage() && !VD->getType()->isReferenceType() + && !VD->getType().isVolatileQualified(); +} + +Action::OwningStmtResult +Sema::ActOnReturnStmt(SourceLocation ReturnLoc, FullExprArg rex) { + Expr *RetValExp = rex->takeAs<Expr>(); + if (CurBlock) + return ActOnBlockReturnStmt(ReturnLoc, RetValExp); + + QualType FnRetType; + if (const FunctionDecl *FD = getCurFunctionDecl()) { + FnRetType = FD->getResultType(); + if (FD->hasAttr<NoReturnAttr>()) + Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) + << getCurFunctionOrMethodDecl()->getDeclName(); + } else if (ObjCMethodDecl *MD = getCurMethodDecl()) + FnRetType = MD->getResultType(); + else // If we don't have a function/method context, bail. + return StmtError(); + + if (FnRetType->isVoidType()) { + if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) + unsigned D = diag::ext_return_has_expr; + if (RetValExp->getType()->isVoidType()) + D = diag::ext_return_has_void_expr; + + // return (some void expression); is legal in C++. + if (D != diag::ext_return_has_void_expr || + !getLangOptions().CPlusPlus) { + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + Diag(ReturnLoc, D) + << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) + << RetValExp->getSourceRange(); + } + } + return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); + } + + if (!RetValExp && !FnRetType->isDependentType()) { + unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 + // C99 6.8.6.4p1 (ext_ since GCC warns) + if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; + + if (FunctionDecl *FD = getCurFunctionDecl()) + Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; + else + Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; + return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); + } + + if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { + // we have a non-void function with an expression, continue checking + + // C99 6.8.6.4p3(136): The return statement is not an assignment. The + // overlap restriction of subclause 6.5.16.1 does not apply to the case of + // function return. + + // C++0x 12.8p15: When certain criteria are met, an implementation is + // allowed to omit the copy construction of a class object, [...] + // - in a return statement in a function with a class return type, when + // the expression is the name of a non-volatile automatic object with + // the same cv-unqualified type as the function return type, the copy + // operation can be omitted [...] + // C++0x 12.8p16: When the criteria for elision of a copy operation are met + // and the object to be copied is designated by an lvalue, overload + // resolution to select the constructor for the copy is first performed + // as if the object were designated by an rvalue. + // Note that we only compute Elidable if we're in C++0x, since we don't + // care otherwise. + bool Elidable = getLangOptions().CPlusPlus0x ? + IsReturnCopyElidable(Context, FnRetType, RetValExp) : + false; + + // In C++ the return statement is handled via a copy initialization. + // the C version of which boils down to CheckSingleAssignmentConstraints. + // FIXME: Leaks RetValExp on error. + if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) + return StmtError(); + + if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); + } + + return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); +} + +/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently +/// ignore "noop" casts in places where an lvalue is required by an inline asm. +/// We emulate this behavior when -fheinous-gnu-extensions is specified, but +/// provide a strong guidance to not use it. +/// +/// This method checks to see if the argument is an acceptable l-value and +/// returns false if it is a case we can handle. +static bool CheckAsmLValue(const Expr *E, Sema &S) { + if (E->isLvalue(S.Context) == Expr::LV_Valid) + return false; // Cool, this is an lvalue. + + // Okay, this is not an lvalue, but perhaps it is the result of a cast that we + // are supposed to allow. + const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); + if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { + if (!S.getLangOptions().HeinousExtensions) + S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) + << E->getSourceRange(); + else + S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) + << E->getSourceRange(); + // Accept, even if we emitted an error diagnostic. + return false; + } + + // None of the above, just randomly invalid non-lvalue. + return true; +} + + +Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, + bool IsSimple, + bool IsVolatile, + unsigned NumOutputs, + unsigned NumInputs, + std::string *Names, + MultiExprArg constraints, + MultiExprArg exprs, + ExprArg asmString, + MultiExprArg clobbers, + SourceLocation RParenLoc) { + unsigned NumClobbers = clobbers.size(); + StringLiteral **Constraints = + reinterpret_cast<StringLiteral**>(constraints.get()); + Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); + StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); + StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); + + llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; + + // The parser verifies that there is a string literal here. + if (AsmString->isWide()) + return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) + << AsmString->getSourceRange()); + + for (unsigned i = 0; i != NumOutputs; i++) { + StringLiteral *Literal = Constraints[i]; + if (Literal->isWide()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + TargetInfo::ConstraintInfo Info(Literal->getStrData(), + Literal->getByteLength(), + Names[i]); + if (!Context.Target.validateOutputConstraint(Info)) + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_invalid_output_constraint) + << Info.getConstraintStr()); + + // Check that the output exprs are valid lvalues. + Expr *OutputExpr = Exprs[i]; + if (CheckAsmLValue(OutputExpr, *this)) { + return StmtError(Diag(OutputExpr->getLocStart(), + diag::err_asm_invalid_lvalue_in_output) + << OutputExpr->getSourceRange()); + } + + OutputConstraintInfos.push_back(Info); + } + + llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; + + for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { + StringLiteral *Literal = Constraints[i]; + if (Literal->isWide()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + TargetInfo::ConstraintInfo Info(Literal->getStrData(), + Literal->getByteLength(), + Names[i]); + if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(), + NumOutputs, Info)) { + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_invalid_input_constraint) + << Info.getConstraintStr()); + } + + Expr *InputExpr = Exprs[i]; + + // Only allow void types for memory constraints. + if (Info.allowsMemory() && !Info.allowsRegister()) { + if (CheckAsmLValue(InputExpr, *this)) + return StmtError(Diag(InputExpr->getLocStart(), + diag::err_asm_invalid_lvalue_in_input) + << Info.getConstraintStr() + << InputExpr->getSourceRange()); + } + + if (Info.allowsRegister()) { + if (InputExpr->getType()->isVoidType()) { + return StmtError(Diag(InputExpr->getLocStart(), + diag::err_asm_invalid_type_in_input) + << InputExpr->getType() << Info.getConstraintStr() + << InputExpr->getSourceRange()); + } + } + + DefaultFunctionArrayConversion(Exprs[i]); + + InputConstraintInfos.push_back(Info); + } + + // Check that the clobbers are valid. + for (unsigned i = 0; i != NumClobbers; i++) { + StringLiteral *Literal = Clobbers[i]; + if (Literal->isWide()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + llvm::SmallString<16> Clobber(Literal->getStrData(), + Literal->getStrData() + + Literal->getByteLength()); + + if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_unknown_register_name) << Clobber.c_str()); + } + + constraints.release(); + exprs.release(); + asmString.release(); + clobbers.release(); + AsmStmt *NS = + new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, + Names, Constraints, Exprs, AsmString, NumClobbers, + Clobbers, RParenLoc); + // Validate the asm string, ensuring it makes sense given the operands we + // have. + llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; + unsigned DiagOffs; + if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { + Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) + << AsmString->getSourceRange(); + DeleteStmt(NS); + return StmtError(); + } + + // Validate tied input operands for type mismatches. + for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { + TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; + + // If this is a tied constraint, verify that the output and input have + // either exactly the same type, or that they are int/ptr operands with the + // same size (int/long, int*/long, are ok etc). + if (!Info.hasTiedOperand()) continue; + + unsigned TiedTo = Info.getTiedOperand(); + Expr *OutputExpr = Exprs[TiedTo]; + Expr *InputExpr = Exprs[i+NumOutputs]; + QualType InTy = InputExpr->getType(); + QualType OutTy = OutputExpr->getType(); + if (Context.hasSameType(InTy, OutTy)) + continue; // All types can be tied to themselves. + + // Int/ptr operands have some special cases that we allow. + if ((OutTy->isIntegerType() || OutTy->isPointerType()) && + (InTy->isIntegerType() || InTy->isPointerType())) { + + // They are ok if they are the same size. Tying void* to int is ok if + // they are the same size, for example. This also allows tying void* to + // int*. + uint64_t OutSize = Context.getTypeSize(OutTy); + uint64_t InSize = Context.getTypeSize(InTy); + if (OutSize == InSize) + continue; + + // If the smaller input/output operand is not mentioned in the asm string, + // then we can promote it and the asm string won't notice. Check this + // case now. + bool SmallerValueMentioned = false; + for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { + AsmStmt::AsmStringPiece &Piece = Pieces[p]; + if (!Piece.isOperand()) continue; + + // If this is a reference to the input and if the input was the smaller + // one, then we have to reject this asm. + if (Piece.getOperandNo() == i+NumOutputs) { + if (InSize < OutSize) { + SmallerValueMentioned = true; + break; + } + } + + // If this is a reference to the input and if the input was the smaller + // one, then we have to reject this asm. + if (Piece.getOperandNo() == TiedTo) { + if (InSize > OutSize) { + SmallerValueMentioned = true; + break; + } + } + } + + // If the smaller value wasn't mentioned in the asm string, and if the + // output was a register, just extend the shorter one to the size of the + // larger one. + if (!SmallerValueMentioned && + OutputConstraintInfos[TiedTo].allowsRegister()) + continue; + } + + Diag(InputExpr->getLocStart(), + diag::err_asm_tying_incompatible_types) + << InTy << OutTy << OutputExpr->getSourceRange() + << InputExpr->getSourceRange(); + DeleteStmt(NS); + return StmtError(); + } + + return Owned(NS); +} + +Action::OwningStmtResult +Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, + SourceLocation RParen, DeclPtrTy Parm, + StmtArg Body, StmtArg catchList) { + Stmt *CatchList = catchList.takeAs<Stmt>(); + ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); + + // PVD == 0 implies @catch(...). + if (PVD) { + // If we already know the decl is invalid, reject it. + if (PVD->isInvalidDecl()) + return StmtError(); + + if (!Context.isObjCObjectPointerType(PVD->getType())) + return StmtError(Diag(PVD->getLocation(), + diag::err_catch_param_not_objc_type)); + if (PVD->getType()->isObjCQualifiedIdType()) + return StmtError(Diag(PVD->getLocation(), + diag::err_illegal_qualifiers_on_catch_parm)); + } + + ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, + PVD, Body.takeAs<Stmt>(), CatchList); + return Owned(CatchList ? CatchList : CS); +} + +Action::OwningStmtResult +Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { + return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, + static_cast<Stmt*>(Body.release()))); +} + +Action::OwningStmtResult +Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, + StmtArg Try, StmtArg Catch, StmtArg Finally) { + CurFunctionNeedsScopeChecking = true; + return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), + Catch.takeAs<Stmt>(), + Finally.takeAs<Stmt>())); +} + +Action::OwningStmtResult +Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { + Expr *ThrowExpr = expr.takeAs<Expr>(); + if (!ThrowExpr) { + // @throw without an expression designates a rethrow (which much occur + // in the context of an @catch clause). + Scope *AtCatchParent = CurScope; + while (AtCatchParent && !AtCatchParent->isAtCatchScope()) + AtCatchParent = AtCatchParent->getParent(); + if (!AtCatchParent) + return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); + } else { + QualType ThrowType = ThrowExpr->getType(); + // Make sure the expression type is an ObjC pointer or "void *". + if (!Context.isObjCObjectPointerType(ThrowType)) { + const PointerType *PT = ThrowType->getAsPointerType(); + if (!PT || !PT->getPointeeType()->isVoidType()) + return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) + << ThrowExpr->getType() << ThrowExpr->getSourceRange()); + } + } + return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); +} + +Action::OwningStmtResult +Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, + StmtArg SynchBody) { + CurFunctionNeedsScopeChecking = true; + + // Make sure the expression type is an ObjC pointer or "void *". + Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); + if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { + const PointerType *PT = SyncExpr->getType()->getAsPointerType(); + if (!PT || !PT->getPointeeType()->isVoidType()) + return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) + << SyncExpr->getType() << SyncExpr->getSourceRange()); + } + + return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, + SynchExpr.takeAs<Stmt>(), + SynchBody.takeAs<Stmt>())); +} + +/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block +/// and creates a proper catch handler from them. +Action::OwningStmtResult +Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, + StmtArg HandlerBlock) { + // There's nothing to test that ActOnExceptionDecl didn't already test. + return Owned(new (Context) CXXCatchStmt(CatchLoc, + cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), + HandlerBlock.takeAs<Stmt>())); +} + +/// ActOnCXXTryBlock - Takes a try compound-statement and a number of +/// handlers and creates a try statement from them. +Action::OwningStmtResult +Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, + MultiStmtArg RawHandlers) { + unsigned NumHandlers = RawHandlers.size(); + assert(NumHandlers > 0 && + "The parser shouldn't call this if there are no handlers."); + Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); + + for(unsigned i = 0; i < NumHandlers - 1; ++i) { + CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); + if (!Handler->getExceptionDecl()) + return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); + } + // FIXME: We should detect handlers for the same type as an earlier one. + // This one is rather easy. + // FIXME: We should detect handlers that cannot catch anything because an + // earlier handler catches a superclass. Need to find a method that is not + // quadratic for this. + // Neither of these are explicitly forbidden, but every compiler detects them + // and warns. + + CurFunctionNeedsScopeChecking = true; + RawHandlers.release(); + return Owned(new (Context) CXXTryStmt(TryLoc, + static_cast<Stmt*>(TryBlock.release()), + Handlers, NumHandlers)); +} |
