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Diffstat (limited to 'clang/lib/Sema/SemaStmt.cpp')
| -rw-r--r-- | clang/lib/Sema/SemaStmt.cpp | 4446 |
1 files changed, 4446 insertions, 0 deletions
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp new file mode 100644 index 000000000000..6c680f29da4f --- /dev/null +++ b/clang/lib/Sema/SemaStmt.cpp @@ -0,0 +1,4446 @@ +//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements semantic analysis for statements. +// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/Ownership.h" +#include "clang/Sema/SemaInternal.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTDiagnostic.h" +#include "clang/AST/ASTLambda.h" +#include "clang/AST/CharUnits.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/EvaluatedExprVisitor.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/AST/StmtCXX.h" +#include "clang/AST/StmtObjC.h" +#include "clang/AST/TypeLoc.h" +#include "clang/AST/TypeOrdering.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/Initialization.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/Scope.h" +#include "clang/Sema/ScopeInfo.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/SmallVector.h" + +using namespace clang; +using namespace sema; + +StmtResult Sema::ActOnExprStmt(ExprResult FE, bool DiscardedValue) { + if (FE.isInvalid()) + return StmtError(); + + FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), DiscardedValue); + if (FE.isInvalid()) + return StmtError(); + + // 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 StmtResult(FE.getAs<Stmt>()); +} + + +StmtResult Sema::ActOnExprStmtError() { + DiscardCleanupsInEvaluationContext(); + return StmtError(); +} + +StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, + bool HasLeadingEmptyMacro) { + return new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro); +} + +StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, + SourceLocation EndLoc) { + DeclGroupRef DG = dg.get(); + + // If we have an invalid decl, just return an error. + if (DG.isNull()) return StmtError(); + + return new (Context) DeclStmt(DG, StartLoc, EndLoc); +} + +void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { + DeclGroupRef DG = dg.get(); + + // If we don't have a declaration, or we have an invalid declaration, + // just return. + if (DG.isNull() || !DG.isSingleDecl()) + return; + + Decl *decl = DG.getSingleDecl(); + if (!decl || decl->isInvalidDecl()) + return; + + // Only variable declarations are permitted. + VarDecl *var = dyn_cast<VarDecl>(decl); + if (!var) { + Diag(decl->getLocation(), diag::err_non_variable_decl_in_for); + decl->setInvalidDecl(); + return; + } + + // foreach variables are never actually initialized in the way that + // the parser came up with. + var->setInit(nullptr); + + // In ARC, we don't need to retain the iteration variable of a fast + // enumeration loop. Rather than actually trying to catch that + // during declaration processing, we remove the consequences here. + if (getLangOpts().ObjCAutoRefCount) { + QualType type = var->getType(); + + // Only do this if we inferred the lifetime. Inferred lifetime + // will show up as a local qualifier because explicit lifetime + // should have shown up as an AttributedType instead. + if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { + // Add 'const' and mark the variable as pseudo-strong. + var->setType(type.withConst()); + var->setARCPseudoStrong(true); + } + } +} + +/// Diagnose unused comparisons, both builtin and overloaded operators. +/// For '==' and '!=', suggest fixits for '=' or '|='. +/// +/// Adding a cast to void (or other expression wrappers) will prevent the +/// warning from firing. +static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { + SourceLocation Loc; + bool CanAssign; + enum { Equality, Inequality, Relational, ThreeWay } Kind; + + if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { + if (!Op->isComparisonOp()) + return false; + + if (Op->getOpcode() == BO_EQ) + Kind = Equality; + else if (Op->getOpcode() == BO_NE) + Kind = Inequality; + else if (Op->getOpcode() == BO_Cmp) + Kind = ThreeWay; + else { + assert(Op->isRelationalOp()); + Kind = Relational; + } + Loc = Op->getOperatorLoc(); + CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); + } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { + switch (Op->getOperator()) { + case OO_EqualEqual: + Kind = Equality; + break; + case OO_ExclaimEqual: + Kind = Inequality; + break; + case OO_Less: + case OO_Greater: + case OO_GreaterEqual: + case OO_LessEqual: + Kind = Relational; + break; + case OO_Spaceship: + Kind = ThreeWay; + break; + default: + return false; + } + + Loc = Op->getOperatorLoc(); + CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); + } else { + // Not a typo-prone comparison. + return false; + } + + // Suppress warnings when the operator, suspicious as it may be, comes from + // a macro expansion. + if (S.SourceMgr.isMacroBodyExpansion(Loc)) + return false; + + S.Diag(Loc, diag::warn_unused_comparison) + << (unsigned)Kind << E->getSourceRange(); + + // If the LHS is a plausible entity to assign to, provide a fixit hint to + // correct common typos. + if (CanAssign) { + if (Kind == Inequality) + S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) + << FixItHint::CreateReplacement(Loc, "|="); + else if (Kind == Equality) + S.Diag(Loc, diag::note_equality_comparison_to_assign) + << FixItHint::CreateReplacement(Loc, "="); + } + + return true; +} + +static bool DiagnoseNoDiscard(Sema &S, const WarnUnusedResultAttr *A, + SourceLocation Loc, SourceRange R1, + SourceRange R2, bool IsCtor) { + if (!A) + return false; + StringRef Msg = A->getMessage(); + + if (Msg.empty()) { + if (IsCtor) + return S.Diag(Loc, diag::warn_unused_constructor) << A << R1 << R2; + return S.Diag(Loc, diag::warn_unused_result) << A << R1 << R2; + } + + if (IsCtor) + return S.Diag(Loc, diag::warn_unused_constructor_msg) << A << Msg << R1 + << R2; + return S.Diag(Loc, diag::warn_unused_result_msg) << A << Msg << R1 << R2; +} + +void Sema::DiagnoseUnusedExprResult(const Stmt *S) { + if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) + return DiagnoseUnusedExprResult(Label->getSubStmt()); + + const Expr *E = dyn_cast_or_null<Expr>(S); + if (!E) + return; + + // If we are in an unevaluated expression context, then there can be no unused + // results because the results aren't expected to be used in the first place. + if (isUnevaluatedContext()) + return; + + SourceLocation ExprLoc = E->IgnoreParenImpCasts()->getExprLoc(); + // In most cases, we don't want to warn if the expression is written in a + // macro body, or if the macro comes from a system header. If the offending + // expression is a call to a function with the warn_unused_result attribute, + // we warn no matter the location. Because of the order in which the various + // checks need to happen, we factor out the macro-related test here. + bool ShouldSuppress = + SourceMgr.isMacroBodyExpansion(ExprLoc) || + SourceMgr.isInSystemMacro(ExprLoc); + + const Expr *WarnExpr; + SourceLocation Loc; + SourceRange R1, R2; + if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context)) + return; + + // If this is a GNU statement expression expanded from a macro, it is probably + // unused because it is a function-like macro that can be used as either an + // expression or statement. Don't warn, because it is almost certainly a + // false positive. + if (isa<StmtExpr>(E) && Loc.isMacroID()) + return; + + // Check if this is the UNREFERENCED_PARAMETER from the Microsoft headers. + // That macro is frequently used to suppress "unused parameter" warnings, + // but its implementation makes clang's -Wunused-value fire. Prevent this. + if (isa<ParenExpr>(E->IgnoreImpCasts()) && Loc.isMacroID()) { + SourceLocation SpellLoc = Loc; + if (findMacroSpelling(SpellLoc, "UNREFERENCED_PARAMETER")) + return; + } + + // Okay, we have an unused result. Depending on what the base expression is, + // we might want to make a more specific diagnostic. Check for one of these + // cases now. + unsigned DiagID = diag::warn_unused_expr; + if (const FullExpr *Temps = dyn_cast<FullExpr>(E)) + E = Temps->getSubExpr(); + if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) + E = TempExpr->getSubExpr(); + + if (DiagnoseUnusedComparison(*this, E)) + return; + + E = WarnExpr; + if (const auto *Cast = dyn_cast<CastExpr>(E)) + if (Cast->getCastKind() == CK_NoOp || + Cast->getCastKind() == CK_ConstructorConversion) + E = Cast->getSubExpr()->IgnoreImpCasts(); + + if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { + if (E->getType()->isVoidType()) + return; + + if (DiagnoseNoDiscard(*this, cast_or_null<WarnUnusedResultAttr>( + CE->getUnusedResultAttr(Context)), + Loc, R1, R2, /*isCtor=*/false)) + return; + + // If the callee has attribute pure, const, or warn_unused_result, warn with + // a more specific message to make it clear what is happening. If the call + // is written in a macro body, only warn if it has the warn_unused_result + // attribute. + if (const Decl *FD = CE->getCalleeDecl()) { + if (ShouldSuppress) + return; + if (FD->hasAttr<PureAttr>()) { + Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; + return; + } + if (FD->hasAttr<ConstAttr>()) { + Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; + return; + } + } + } else if (const auto *CE = dyn_cast<CXXConstructExpr>(E)) { + if (const CXXConstructorDecl *Ctor = CE->getConstructor()) { + const auto *A = Ctor->getAttr<WarnUnusedResultAttr>(); + A = A ? A : Ctor->getParent()->getAttr<WarnUnusedResultAttr>(); + if (DiagnoseNoDiscard(*this, A, Loc, R1, R2, /*isCtor=*/true)) + return; + } + } else if (const auto *ILE = dyn_cast<InitListExpr>(E)) { + if (const TagDecl *TD = ILE->getType()->getAsTagDecl()) { + + if (DiagnoseNoDiscard(*this, TD->getAttr<WarnUnusedResultAttr>(), Loc, R1, + R2, /*isCtor=*/false)) + return; + } + } else if (ShouldSuppress) + return; + + E = WarnExpr; + if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { + if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { + Diag(Loc, diag::err_arc_unused_init_message) << R1; + return; + } + const ObjCMethodDecl *MD = ME->getMethodDecl(); + if (MD) { + if (DiagnoseNoDiscard(*this, MD->getAttr<WarnUnusedResultAttr>(), Loc, R1, + R2, /*isCtor=*/false)) + return; + } + } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { + const Expr *Source = POE->getSyntacticForm(); + if (isa<ObjCSubscriptRefExpr>(Source)) + DiagID = diag::warn_unused_container_subscript_expr; + else + DiagID = diag::warn_unused_property_expr; + } else if (const CXXFunctionalCastExpr *FC + = dyn_cast<CXXFunctionalCastExpr>(E)) { + const Expr *E = FC->getSubExpr(); + if (const CXXBindTemporaryExpr *TE = dyn_cast<CXXBindTemporaryExpr>(E)) + E = TE->getSubExpr(); + if (isa<CXXTemporaryObjectExpr>(E)) + return; + if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(E)) + if (const CXXRecordDecl *RD = CE->getType()->getAsCXXRecordDecl()) + if (!RD->getAttr<WarnUnusedAttr>()) + return; + } + // Diagnose "(void*) blah" as a typo for "(void) blah". + else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { + TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); + QualType T = TI->getType(); + + // We really do want to use the non-canonical type here. + if (T == Context.VoidPtrTy) { + PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>(); + + Diag(Loc, diag::warn_unused_voidptr) + << FixItHint::CreateRemoval(TL.getStarLoc()); + return; + } + } + + if (E->isGLValue() && E->getType().isVolatileQualified()) { + Diag(Loc, diag::warn_unused_volatile) << R1 << R2; + return; + } + + DiagRuntimeBehavior(Loc, nullptr, PDiag(DiagID) << R1 << R2); +} + +void Sema::ActOnStartOfCompoundStmt(bool IsStmtExpr) { + PushCompoundScope(IsStmtExpr); +} + +void Sema::ActOnFinishOfCompoundStmt() { + PopCompoundScope(); +} + +sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { + return getCurFunction()->CompoundScopes.back(); +} + +StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, + ArrayRef<Stmt *> Elts, bool isStmtExpr) { + const unsigned NumElts = Elts.size(); + + // If we're in C89 mode, check that we don't have any decls after stmts. If + // so, emit an extension diagnostic. + if (!getLangOpts().C99 && !getLangOpts().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); + } + } + + // Check for suspicious empty body (null statement) in `for' and `while' + // statements. Don't do anything for template instantiations, this just adds + // noise. + if (NumElts != 0 && !CurrentInstantiationScope && + getCurCompoundScope().HasEmptyLoopBodies) { + for (unsigned i = 0; i != NumElts - 1; ++i) + DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); + } + + return CompoundStmt::Create(Context, Elts, L, R); +} + +ExprResult +Sema::ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val) { + if (!Val.get()) + return Val; + + if (DiagnoseUnexpandedParameterPack(Val.get())) + return ExprError(); + + // If we're not inside a switch, let the 'case' statement handling diagnose + // this. Just clean up after the expression as best we can. + if (getCurFunction()->SwitchStack.empty()) + return ActOnFinishFullExpr(Val.get(), Val.get()->getExprLoc(), false, + getLangOpts().CPlusPlus11); + + Expr *CondExpr = + getCurFunction()->SwitchStack.back().getPointer()->getCond(); + if (!CondExpr) + return ExprError(); + QualType CondType = CondExpr->getType(); + + auto CheckAndFinish = [&](Expr *E) { + if (CondType->isDependentType() || E->isTypeDependent()) + return ExprResult(E); + + if (getLangOpts().CPlusPlus11) { + // C++11 [stmt.switch]p2: the constant-expression shall be a converted + // constant expression of the promoted type of the switch condition. + llvm::APSInt TempVal; + return CheckConvertedConstantExpression(E, CondType, TempVal, + CCEK_CaseValue); + } + + ExprResult ER = E; + if (!E->isValueDependent()) + ER = VerifyIntegerConstantExpression(E); + if (!ER.isInvalid()) + ER = DefaultLvalueConversion(ER.get()); + if (!ER.isInvalid()) + ER = ImpCastExprToType(ER.get(), CondType, CK_IntegralCast); + if (!ER.isInvalid()) + ER = ActOnFinishFullExpr(ER.get(), ER.get()->getExprLoc(), false); + return ER; + }; + + ExprResult Converted = CorrectDelayedTyposInExpr(Val, CheckAndFinish); + if (Converted.get() == Val.get()) + Converted = CheckAndFinish(Val.get()); + return Converted; +} + +StmtResult +Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHSVal, + SourceLocation DotDotDotLoc, ExprResult RHSVal, + SourceLocation ColonLoc) { + assert((LHSVal.isInvalid() || LHSVal.get()) && "missing LHS value"); + assert((DotDotDotLoc.isInvalid() ? RHSVal.isUnset() + : RHSVal.isInvalid() || RHSVal.get()) && + "missing RHS value"); + + if (getCurFunction()->SwitchStack.empty()) { + Diag(CaseLoc, diag::err_case_not_in_switch); + return StmtError(); + } + + if (LHSVal.isInvalid() || RHSVal.isInvalid()) { + getCurFunction()->SwitchStack.back().setInt(true); + return StmtError(); + } + + auto *CS = CaseStmt::Create(Context, LHSVal.get(), RHSVal.get(), + CaseLoc, DotDotDotLoc, ColonLoc); + getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(CS); + return CS; +} + +/// ActOnCaseStmtBody - This installs a statement as the body of a case. +void Sema::ActOnCaseStmtBody(Stmt *S, Stmt *SubStmt) { + cast<CaseStmt>(S)->setSubStmt(SubStmt); +} + +StmtResult +Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, + Stmt *SubStmt, Scope *CurScope) { + if (getCurFunction()->SwitchStack.empty()) { + Diag(DefaultLoc, diag::err_default_not_in_switch); + return SubStmt; + } + + DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); + getCurFunction()->SwitchStack.back().getPointer()->addSwitchCase(DS); + return DS; +} + +StmtResult +Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, + SourceLocation ColonLoc, Stmt *SubStmt) { + // If the label was multiply defined, reject it now. + if (TheDecl->getStmt()) { + Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); + Diag(TheDecl->getLocation(), diag::note_previous_definition); + return SubStmt; + } + + // Otherwise, things are good. Fill in the declaration and return it. + LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); + TheDecl->setStmt(LS); + if (!TheDecl->isGnuLocal()) { + TheDecl->setLocStart(IdentLoc); + if (!TheDecl->isMSAsmLabel()) { + // Don't update the location of MS ASM labels. These will result in + // a diagnostic, and changing the location here will mess that up. + TheDecl->setLocation(IdentLoc); + } + } + return LS; +} + +StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, + ArrayRef<const Attr*> Attrs, + Stmt *SubStmt) { + // Fill in the declaration and return it. + AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt); + return LS; +} + +namespace { +class CommaVisitor : public EvaluatedExprVisitor<CommaVisitor> { + typedef EvaluatedExprVisitor<CommaVisitor> Inherited; + Sema &SemaRef; +public: + CommaVisitor(Sema &SemaRef) : Inherited(SemaRef.Context), SemaRef(SemaRef) {} + void VisitBinaryOperator(BinaryOperator *E) { + if (E->getOpcode() == BO_Comma) + SemaRef.DiagnoseCommaOperator(E->getLHS(), E->getExprLoc()); + EvaluatedExprVisitor<CommaVisitor>::VisitBinaryOperator(E); + } +}; +} + +StmtResult +Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt, + ConditionResult Cond, + Stmt *thenStmt, SourceLocation ElseLoc, + Stmt *elseStmt) { + if (Cond.isInvalid()) + Cond = ConditionResult( + *this, nullptr, + MakeFullExpr(new (Context) OpaqueValueExpr(SourceLocation(), + Context.BoolTy, VK_RValue), + IfLoc), + false); + + Expr *CondExpr = Cond.get().second; + // Only call the CommaVisitor when not C89 due to differences in scope flags. + if ((getLangOpts().C99 || getLangOpts().CPlusPlus) && + !Diags.isIgnored(diag::warn_comma_operator, CondExpr->getExprLoc())) + CommaVisitor(*this).Visit(CondExpr); + + if (!elseStmt) + DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), thenStmt, + diag::warn_empty_if_body); + + return BuildIfStmt(IfLoc, IsConstexpr, InitStmt, Cond, thenStmt, ElseLoc, + elseStmt); +} + +StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr, + Stmt *InitStmt, ConditionResult Cond, + Stmt *thenStmt, SourceLocation ElseLoc, + Stmt *elseStmt) { + if (Cond.isInvalid()) + return StmtError(); + + if (IsConstexpr || isa<ObjCAvailabilityCheckExpr>(Cond.get().second)) + setFunctionHasBranchProtectedScope(); + + return IfStmt::Create(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first, + Cond.get().second, thenStmt, ElseLoc, elseStmt); +} + +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; +} + +/// CmpEnumVals - Comparison predicate for sorting enumeration values. +/// +static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, + const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) +{ + return lhs.first < rhs.first; +} + +/// EqEnumVals - Comparison preficate for uniqing enumeration values. +/// +static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, + const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) +{ + return lhs.first == rhs.first; +} + +/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of +/// potentially integral-promoted expression @p expr. +static QualType GetTypeBeforeIntegralPromotion(const Expr *&E) { + if (const auto *FE = dyn_cast<FullExpr>(E)) + E = FE->getSubExpr(); + while (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E)) { + if (ImpCast->getCastKind() != CK_IntegralCast) break; + E = ImpCast->getSubExpr(); + } + return E->getType(); +} + +ExprResult Sema::CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond) { + class SwitchConvertDiagnoser : public ICEConvertDiagnoser { + Expr *Cond; + + public: + SwitchConvertDiagnoser(Expr *Cond) + : ICEConvertDiagnoser(/*AllowScopedEnumerations*/true, false, true), + Cond(Cond) {} + + SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T; + } + + SemaDiagnosticBuilder diagnoseIncomplete( + Sema &S, SourceLocation Loc, QualType T) override { + return S.Diag(Loc, diag::err_switch_incomplete_class_type) + << T << Cond->getSourceRange(); + } + + SemaDiagnosticBuilder diagnoseExplicitConv( + Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { + return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy; + } + + SemaDiagnosticBuilder noteExplicitConv( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_switch_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_switch_multiple_conversions) << T; + } + + SemaDiagnosticBuilder noteAmbiguous( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_switch_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + SemaDiagnosticBuilder diagnoseConversion( + Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { + llvm_unreachable("conversion functions are permitted"); + } + } SwitchDiagnoser(Cond); + + ExprResult CondResult = + PerformContextualImplicitConversion(SwitchLoc, Cond, SwitchDiagnoser); + if (CondResult.isInvalid()) + return ExprError(); + + // FIXME: PerformContextualImplicitConversion doesn't always tell us if it + // failed and produced a diagnostic. + Cond = CondResult.get(); + if (!Cond->isTypeDependent() && + !Cond->getType()->isIntegralOrEnumerationType()) + return ExprError(); + + // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. + return UsualUnaryConversions(Cond); +} + +StmtResult Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, + Stmt *InitStmt, ConditionResult Cond) { + Expr *CondExpr = Cond.get().second; + assert((Cond.isInvalid() || CondExpr) && "switch with no condition"); + + if (CondExpr && !CondExpr->isTypeDependent()) { + // We have already converted the expression to an integral or enumeration + // type, when we parsed the switch condition. If we don't have an + // appropriate type now, enter the switch scope but remember that it's + // invalid. + assert(CondExpr->getType()->isIntegralOrEnumerationType() && + "invalid condition type"); + if (CondExpr->isKnownToHaveBooleanValue()) { + // switch(bool_expr) {...} is often a programmer error, e.g. + // switch(n && mask) { ... } // Doh - should be "n & mask". + // One can always use an if statement instead of switch(bool_expr). + Diag(SwitchLoc, diag::warn_bool_switch_condition) + << CondExpr->getSourceRange(); + } + } + + setFunctionHasBranchIntoScope(); + + auto *SS = SwitchStmt::Create(Context, InitStmt, Cond.get().first, CondExpr); + getCurFunction()->SwitchStack.push_back( + FunctionScopeInfo::SwitchInfo(SS, false)); + return SS; +} + +static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { + Val = Val.extOrTrunc(BitWidth); + Val.setIsSigned(IsSigned); +} + +/// Check the specified case value is in range for the given unpromoted switch +/// type. +static void checkCaseValue(Sema &S, SourceLocation Loc, const llvm::APSInt &Val, + unsigned UnpromotedWidth, bool UnpromotedSign) { + // In C++11 onwards, this is checked by the language rules. + if (S.getLangOpts().CPlusPlus11) + return; + + // If the case value was signed and negative and the switch expression is + // unsigned, don't bother to warn: this is implementation-defined behavior. + // FIXME: Introduce a second, default-ignored warning for this case? + if (UnpromotedWidth < Val.getBitWidth()) { + llvm::APSInt ConvVal(Val); + AdjustAPSInt(ConvVal, UnpromotedWidth, UnpromotedSign); + AdjustAPSInt(ConvVal, Val.getBitWidth(), Val.isSigned()); + // FIXME: Use different diagnostics for overflow in conversion to promoted + // type versus "switch expression cannot have this value". Use proper + // IntRange checking rather than just looking at the unpromoted type here. + if (ConvVal != Val) + S.Diag(Loc, diag::warn_case_value_overflow) << Val.toString(10) + << ConvVal.toString(10); + } +} + +typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> EnumValsTy; + +/// Returns true if we should emit a diagnostic about this case expression not +/// being a part of the enum used in the switch controlling expression. +static bool ShouldDiagnoseSwitchCaseNotInEnum(const Sema &S, + const EnumDecl *ED, + const Expr *CaseExpr, + EnumValsTy::iterator &EI, + EnumValsTy::iterator &EIEnd, + const llvm::APSInt &Val) { + if (!ED->isClosed()) + return false; + + if (const DeclRefExpr *DRE = + dyn_cast<DeclRefExpr>(CaseExpr->IgnoreParenImpCasts())) { + if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) { + QualType VarType = VD->getType(); + QualType EnumType = S.Context.getTypeDeclType(ED); + if (VD->hasGlobalStorage() && VarType.isConstQualified() && + S.Context.hasSameUnqualifiedType(EnumType, VarType)) + return false; + } + } + + if (ED->hasAttr<FlagEnumAttr>()) + return !S.IsValueInFlagEnum(ED, Val, false); + + while (EI != EIEnd && EI->first < Val) + EI++; + + if (EI != EIEnd && EI->first == Val) + return false; + + return true; +} + +static void checkEnumTypesInSwitchStmt(Sema &S, const Expr *Cond, + const Expr *Case) { + QualType CondType = Cond->getType(); + QualType CaseType = Case->getType(); + + const EnumType *CondEnumType = CondType->getAs<EnumType>(); + const EnumType *CaseEnumType = CaseType->getAs<EnumType>(); + if (!CondEnumType || !CaseEnumType) + return; + + // Ignore anonymous enums. + if (!CondEnumType->getDecl()->getIdentifier() && + !CondEnumType->getDecl()->getTypedefNameForAnonDecl()) + return; + if (!CaseEnumType->getDecl()->getIdentifier() && + !CaseEnumType->getDecl()->getTypedefNameForAnonDecl()) + return; + + if (S.Context.hasSameUnqualifiedType(CondType, CaseType)) + return; + + S.Diag(Case->getExprLoc(), diag::warn_comparison_of_mixed_enum_types_switch) + << CondType << CaseType << Cond->getSourceRange() + << Case->getSourceRange(); +} + +StmtResult +Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, + Stmt *BodyStmt) { + SwitchStmt *SS = cast<SwitchStmt>(Switch); + bool CaseListIsIncomplete = getCurFunction()->SwitchStack.back().getInt(); + assert(SS == getCurFunction()->SwitchStack.back().getPointer() && + "switch stack missing push/pop!"); + + getCurFunction()->SwitchStack.pop_back(); + + if (!BodyStmt) return StmtError(); + SS->setBody(BodyStmt, SwitchLoc); + + Expr *CondExpr = SS->getCond(); + if (!CondExpr) return StmtError(); + + QualType CondType = CondExpr->getType(); + + // C++ 6.4.2.p2: + // Integral promotions are performed (on the switch condition). + // + // A case value unrepresentable by the original switch condition + // type (before the promotion) doesn't make sense, even when it can + // be represented by the promoted type. Therefore we need to find + // the pre-promotion type of the switch condition. + const Expr *CondExprBeforePromotion = CondExpr; + QualType CondTypeBeforePromotion = + GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); + + // Get the bitwidth of the switched-on value after promotions. We must + // convert the integer case values to this width before comparison. + bool HasDependentValue + = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); + unsigned CondWidth = HasDependentValue ? 0 : Context.getIntWidth(CondType); + bool CondIsSigned = CondType->isSignedIntegerOrEnumerationType(); + + // Get the width and signedness that the condition might actually have, for + // warning purposes. + // FIXME: Grab an IntRange for the condition rather than using the unpromoted + // type. + unsigned CondWidthBeforePromotion + = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); + bool CondIsSignedBeforePromotion + = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); + + // 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 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. + typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; + CaseRangesTy CaseRanges; + + DefaultStmt *TheDefaultStmt = nullptr; + + 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); + + Expr *Lo = CS->getLHS(); + + if (Lo->isValueDependent()) { + HasDependentValue = true; + break; + } + + // We already verified that the expression has a constant value; + // get that value (prior to conversions). + const Expr *LoBeforePromotion = Lo; + GetTypeBeforeIntegralPromotion(LoBeforePromotion); + llvm::APSInt LoVal = LoBeforePromotion->EvaluateKnownConstInt(Context); + + // Check the unconverted value is within the range of possible values of + // the switch expression. + checkCaseValue(*this, Lo->getBeginLoc(), LoVal, CondWidthBeforePromotion, + CondIsSignedBeforePromotion); + + // FIXME: This duplicates the check performed for warn_not_in_enum below. + checkEnumTypesInSwitchStmt(*this, CondExprBeforePromotion, + LoBeforePromotion); + + // Convert the value to the same width/sign as the condition. + AdjustAPSInt(LoVal, CondWidth, CondIsSigned); + + // If this is a case range, remember it in CaseRanges, otherwise CaseVals. + if (CS->getRHS()) { + if (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) { + // If we don't have a default statement, check whether the + // condition is constant. + llvm::APSInt ConstantCondValue; + bool HasConstantCond = false; + if (!TheDefaultStmt) { + Expr::EvalResult Result; + HasConstantCond = CondExpr->EvaluateAsInt(Result, Context, + Expr::SE_AllowSideEffects); + if (Result.Val.isInt()) + ConstantCondValue = Result.Val.getInt(); + assert(!HasConstantCond || + (ConstantCondValue.getBitWidth() == CondWidth && + ConstantCondValue.isSigned() == CondIsSigned)); + } + bool ShouldCheckConstantCond = HasConstantCond; + + // Sort all the scalar case values so we can easily detect duplicates. + llvm::stable_sort(CaseVals, CmpCaseVals); + + if (!CaseVals.empty()) { + for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { + if (ShouldCheckConstantCond && + CaseVals[i].first == ConstantCondValue) + ShouldCheckConstantCond = false; + + if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { + // If we have a duplicate, report it. + // First, determine if either case value has a name + StringRef PrevString, CurrString; + Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts(); + Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts(); + if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) { + PrevString = DeclRef->getDecl()->getName(); + } + if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) { + CurrString = DeclRef->getDecl()->getName(); + } + SmallString<16> CaseValStr; + CaseVals[i-1].first.toString(CaseValStr); + + if (PrevString == CurrString) + Diag(CaseVals[i].second->getLHS()->getBeginLoc(), + diag::err_duplicate_case) + << (PrevString.empty() ? StringRef(CaseValStr) : PrevString); + else + Diag(CaseVals[i].second->getLHS()->getBeginLoc(), + diag::err_duplicate_case_differing_expr) + << (PrevString.empty() ? StringRef(CaseValStr) : PrevString) + << (CurrString.empty() ? StringRef(CaseValStr) : CurrString) + << CaseValStr; + + Diag(CaseVals[i - 1].second->getLHS()->getBeginLoc(), + 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. + llvm::stable_sort(CaseRanges); + + // 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) { + llvm::APSInt &LoVal = CaseRanges[i].first; + CaseStmt *CR = CaseRanges[i].second; + Expr *Hi = CR->getRHS(); + + const Expr *HiBeforePromotion = Hi; + GetTypeBeforeIntegralPromotion(HiBeforePromotion); + llvm::APSInt HiVal = HiBeforePromotion->EvaluateKnownConstInt(Context); + + // Check the unconverted value is within the range of possible values of + // the switch expression. + checkCaseValue(*this, Hi->getBeginLoc(), HiVal, + CondWidthBeforePromotion, CondIsSignedBeforePromotion); + + // Convert the value to the same width/sign as the condition. + AdjustAPSInt(HiVal, CondWidth, CondIsSigned); + + // If the low value is bigger than the high value, the case is empty. + if (LoVal > HiVal) { + Diag(CR->getLHS()->getBeginLoc(), diag::warn_case_empty_range) + << SourceRange(CR->getLHS()->getBeginLoc(), Hi->getEndLoc()); + CaseRanges.erase(CaseRanges.begin()+i); + --i; + --e; + continue; + } + + if (ShouldCheckConstantCond && + LoVal <= ConstantCondValue && + ConstantCondValue <= HiVal) + ShouldCheckConstantCond = false; + + 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 = nullptr; + 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 = + llvm::lower_bound(CaseVals, 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()->getBeginLoc(), diag::err_duplicate_case) + << OverlapVal.toString(10); + Diag(OverlapStmt->getLHS()->getBeginLoc(), + 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; + } + } + } + + // Complain if we have a constant condition and we didn't find a match. + if (!CaseListIsErroneous && !CaseListIsIncomplete && + ShouldCheckConstantCond) { + // TODO: it would be nice if we printed enums as enums, chars as + // chars, etc. + Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) + << ConstantCondValue.toString(10) + << CondExpr->getSourceRange(); + } + + // Check to see if switch is over an Enum and handles all of its + // values. We only issue a warning if there is not 'default:', but + // we still do the analysis to preserve this information in the AST + // (which can be used by flow-based analyes). + // + const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); + + // If switch has default case, then ignore it. + if (!CaseListIsErroneous && !CaseListIsIncomplete && !HasConstantCond && + ET && ET->getDecl()->isCompleteDefinition()) { + const EnumDecl *ED = ET->getDecl(); + EnumValsTy EnumVals; + + // Gather all enum values, set their type and sort them, + // allowing easier comparison with CaseVals. + for (auto *EDI : ED->enumerators()) { + llvm::APSInt Val = EDI->getInitVal(); + AdjustAPSInt(Val, CondWidth, CondIsSigned); + EnumVals.push_back(std::make_pair(Val, EDI)); + } + llvm::stable_sort(EnumVals, CmpEnumVals); + auto EI = EnumVals.begin(), EIEnd = + std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); + + // See which case values aren't in enum. + for (CaseValsTy::const_iterator CI = CaseVals.begin(); + CI != CaseVals.end(); CI++) { + Expr *CaseExpr = CI->second->getLHS(); + if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd, + CI->first)) + Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + } + + // See which of case ranges aren't in enum + EI = EnumVals.begin(); + for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); + RI != CaseRanges.end(); RI++) { + Expr *CaseExpr = RI->second->getLHS(); + if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd, + RI->first)) + Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + + llvm::APSInt Hi = + RI->second->getRHS()->EvaluateKnownConstInt(Context); + AdjustAPSInt(Hi, CondWidth, CondIsSigned); + + CaseExpr = RI->second->getRHS(); + if (ShouldDiagnoseSwitchCaseNotInEnum(*this, ED, CaseExpr, EI, EIEnd, + Hi)) + Diag(CaseExpr->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + } + + // Check which enum vals aren't in switch + auto CI = CaseVals.begin(); + auto RI = CaseRanges.begin(); + bool hasCasesNotInSwitch = false; + + SmallVector<DeclarationName,8> UnhandledNames; + + for (EI = EnumVals.begin(); EI != EIEnd; EI++) { + // Don't warn about omitted unavailable EnumConstantDecls. + switch (EI->second->getAvailability()) { + case AR_Deprecated: + // Omitting a deprecated constant is ok; it should never materialize. + case AR_Unavailable: + continue; + + case AR_NotYetIntroduced: + // Partially available enum constants should be present. Note that we + // suppress -Wunguarded-availability diagnostics for such uses. + case AR_Available: + break; + } + + if (EI->second->hasAttr<UnusedAttr>()) + continue; + + // Drop unneeded case values + while (CI != CaseVals.end() && CI->first < EI->first) + CI++; + + if (CI != CaseVals.end() && CI->first == EI->first) + continue; + + // Drop unneeded case ranges + for (; RI != CaseRanges.end(); RI++) { + llvm::APSInt Hi = + RI->second->getRHS()->EvaluateKnownConstInt(Context); + AdjustAPSInt(Hi, CondWidth, CondIsSigned); + if (EI->first <= Hi) + break; + } + + if (RI == CaseRanges.end() || EI->first < RI->first) { + hasCasesNotInSwitch = true; + UnhandledNames.push_back(EI->second->getDeclName()); + } + } + + if (TheDefaultStmt && UnhandledNames.empty() && ED->isClosedNonFlag()) + Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); + + // Produce a nice diagnostic if multiple values aren't handled. + if (!UnhandledNames.empty()) { + DiagnosticBuilder DB = Diag(CondExpr->getExprLoc(), + TheDefaultStmt ? diag::warn_def_missing_case + : diag::warn_missing_case) + << (int)UnhandledNames.size(); + + for (size_t I = 0, E = std::min(UnhandledNames.size(), (size_t)3); + I != E; ++I) + DB << UnhandledNames[I]; + } + + if (!hasCasesNotInSwitch) + SS->setAllEnumCasesCovered(); + } + } + + if (BodyStmt) + DiagnoseEmptyStmtBody(CondExpr->getEndLoc(), BodyStmt, + diag::warn_empty_switch_body); + + // 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(); + + return SS; +} + +void +Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, + Expr *SrcExpr) { + if (Diags.isIgnored(diag::warn_not_in_enum_assignment, SrcExpr->getExprLoc())) + return; + + if (const EnumType *ET = DstType->getAs<EnumType>()) + if (!Context.hasSameUnqualifiedType(SrcType, DstType) && + SrcType->isIntegerType()) { + if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() && + SrcExpr->isIntegerConstantExpr(Context)) { + // Get the bitwidth of the enum value before promotions. + unsigned DstWidth = Context.getIntWidth(DstType); + bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType(); + + llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context); + AdjustAPSInt(RhsVal, DstWidth, DstIsSigned); + const EnumDecl *ED = ET->getDecl(); + + if (!ED->isClosed()) + return; + + if (ED->hasAttr<FlagEnumAttr>()) { + if (!IsValueInFlagEnum(ED, RhsVal, true)) + Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment) + << DstType.getUnqualifiedType(); + } else { + typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64> + EnumValsTy; + EnumValsTy EnumVals; + + // Gather all enum values, set their type and sort them, + // allowing easier comparison with rhs constant. + for (auto *EDI : ED->enumerators()) { + llvm::APSInt Val = EDI->getInitVal(); + AdjustAPSInt(Val, DstWidth, DstIsSigned); + EnumVals.push_back(std::make_pair(Val, EDI)); + } + if (EnumVals.empty()) + return; + llvm::stable_sort(EnumVals, CmpEnumVals); + EnumValsTy::iterator EIend = + std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); + + // See which values aren't in the enum. + EnumValsTy::const_iterator EI = EnumVals.begin(); + while (EI != EIend && EI->first < RhsVal) + EI++; + if (EI == EIend || EI->first != RhsVal) { + Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment) + << DstType.getUnqualifiedType(); + } + } + } + } +} + +StmtResult Sema::ActOnWhileStmt(SourceLocation WhileLoc, ConditionResult Cond, + Stmt *Body) { + if (Cond.isInvalid()) + return StmtError(); + + auto CondVal = Cond.get(); + CheckBreakContinueBinding(CondVal.second); + + if (CondVal.second && + !Diags.isIgnored(diag::warn_comma_operator, CondVal.second->getExprLoc())) + CommaVisitor(*this).Visit(CondVal.second); + + if (isa<NullStmt>(Body)) + getCurCompoundScope().setHasEmptyLoopBodies(); + + return WhileStmt::Create(Context, CondVal.first, CondVal.second, Body, + WhileLoc); +} + +StmtResult +Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, + SourceLocation WhileLoc, SourceLocation CondLParen, + Expr *Cond, SourceLocation CondRParen) { + assert(Cond && "ActOnDoStmt(): missing expression"); + + CheckBreakContinueBinding(Cond); + ExprResult CondResult = CheckBooleanCondition(DoLoc, Cond); + if (CondResult.isInvalid()) + return StmtError(); + Cond = CondResult.get(); + + CondResult = ActOnFinishFullExpr(Cond, DoLoc, /*DiscardedValue*/ false); + if (CondResult.isInvalid()) + return StmtError(); + Cond = CondResult.get(); + + // Only call the CommaVisitor for C89 due to differences in scope flags. + if (Cond && !getLangOpts().C99 && !getLangOpts().CPlusPlus && + !Diags.isIgnored(diag::warn_comma_operator, Cond->getExprLoc())) + CommaVisitor(*this).Visit(Cond); + + return new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen); +} + +namespace { + // Use SetVector since the diagnostic cares about the ordering of the Decl's. + using DeclSetVector = + llvm::SetVector<VarDecl *, llvm::SmallVector<VarDecl *, 8>, + llvm::SmallPtrSet<VarDecl *, 8>>; + + // This visitor will traverse a conditional statement and store all + // the evaluated decls into a vector. Simple is set to true if none + // of the excluded constructs are used. + class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { + DeclSetVector &Decls; + SmallVectorImpl<SourceRange> &Ranges; + bool Simple; + public: + typedef EvaluatedExprVisitor<DeclExtractor> Inherited; + + DeclExtractor(Sema &S, DeclSetVector &Decls, + SmallVectorImpl<SourceRange> &Ranges) : + Inherited(S.Context), + Decls(Decls), + Ranges(Ranges), + Simple(true) {} + + bool isSimple() { return Simple; } + + // Replaces the method in EvaluatedExprVisitor. + void VisitMemberExpr(MemberExpr* E) { + Simple = false; + } + + // Any Stmt not whitelisted will cause the condition to be marked complex. + void VisitStmt(Stmt *S) { + Simple = false; + } + + void VisitBinaryOperator(BinaryOperator *E) { + Visit(E->getLHS()); + Visit(E->getRHS()); + } + + void VisitCastExpr(CastExpr *E) { + Visit(E->getSubExpr()); + } + + void VisitUnaryOperator(UnaryOperator *E) { + // Skip checking conditionals with derefernces. + if (E->getOpcode() == UO_Deref) + Simple = false; + else + Visit(E->getSubExpr()); + } + + void VisitConditionalOperator(ConditionalOperator *E) { + Visit(E->getCond()); + Visit(E->getTrueExpr()); + Visit(E->getFalseExpr()); + } + + void VisitParenExpr(ParenExpr *E) { + Visit(E->getSubExpr()); + } + + void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { + Visit(E->getOpaqueValue()->getSourceExpr()); + Visit(E->getFalseExpr()); + } + + void VisitIntegerLiteral(IntegerLiteral *E) { } + void VisitFloatingLiteral(FloatingLiteral *E) { } + void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } + void VisitCharacterLiteral(CharacterLiteral *E) { } + void VisitGNUNullExpr(GNUNullExpr *E) { } + void VisitImaginaryLiteral(ImaginaryLiteral *E) { } + + void VisitDeclRefExpr(DeclRefExpr *E) { + VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); + if (!VD) { + // Don't allow unhandled Decl types. + Simple = false; + return; + } + + Ranges.push_back(E->getSourceRange()); + + Decls.insert(VD); + } + + }; // end class DeclExtractor + + // DeclMatcher checks to see if the decls are used in a non-evaluated + // context. + class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { + DeclSetVector &Decls; + bool FoundDecl; + + public: + typedef EvaluatedExprVisitor<DeclMatcher> Inherited; + + DeclMatcher(Sema &S, DeclSetVector &Decls, Stmt *Statement) : + Inherited(S.Context), Decls(Decls), FoundDecl(false) { + if (!Statement) return; + + Visit(Statement); + } + + void VisitReturnStmt(ReturnStmt *S) { + FoundDecl = true; + } + + void VisitBreakStmt(BreakStmt *S) { + FoundDecl = true; + } + + void VisitGotoStmt(GotoStmt *S) { + FoundDecl = true; + } + + void VisitCastExpr(CastExpr *E) { + if (E->getCastKind() == CK_LValueToRValue) + CheckLValueToRValueCast(E->getSubExpr()); + else + Visit(E->getSubExpr()); + } + + void CheckLValueToRValueCast(Expr *E) { + E = E->IgnoreParenImpCasts(); + + if (isa<DeclRefExpr>(E)) { + return; + } + + if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { + Visit(CO->getCond()); + CheckLValueToRValueCast(CO->getTrueExpr()); + CheckLValueToRValueCast(CO->getFalseExpr()); + return; + } + + if (BinaryConditionalOperator *BCO = + dyn_cast<BinaryConditionalOperator>(E)) { + CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); + CheckLValueToRValueCast(BCO->getFalseExpr()); + return; + } + + Visit(E); + } + + void VisitDeclRefExpr(DeclRefExpr *E) { + if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) + if (Decls.count(VD)) + FoundDecl = true; + } + + void VisitPseudoObjectExpr(PseudoObjectExpr *POE) { + // Only need to visit the semantics for POE. + // SyntaticForm doesn't really use the Decal. + for (auto *S : POE->semantics()) { + if (auto *OVE = dyn_cast<OpaqueValueExpr>(S)) + // Look past the OVE into the expression it binds. + Visit(OVE->getSourceExpr()); + else + Visit(S); + } + } + + bool FoundDeclInUse() { return FoundDecl; } + + }; // end class DeclMatcher + + void CheckForLoopConditionalStatement(Sema &S, Expr *Second, + Expr *Third, Stmt *Body) { + // Condition is empty + if (!Second) return; + + if (S.Diags.isIgnored(diag::warn_variables_not_in_loop_body, + Second->getBeginLoc())) + return; + + PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); + DeclSetVector Decls; + SmallVector<SourceRange, 10> Ranges; + DeclExtractor DE(S, Decls, Ranges); + DE.Visit(Second); + + // Don't analyze complex conditionals. + if (!DE.isSimple()) return; + + // No decls found. + if (Decls.size() == 0) return; + + // Don't warn on volatile, static, or global variables. + for (auto *VD : Decls) + if (VD->getType().isVolatileQualified() || VD->hasGlobalStorage()) + return; + + if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || + DeclMatcher(S, Decls, Third).FoundDeclInUse() || + DeclMatcher(S, Decls, Body).FoundDeclInUse()) + return; + + // Load decl names into diagnostic. + if (Decls.size() > 4) { + PDiag << 0; + } else { + PDiag << (unsigned)Decls.size(); + for (auto *VD : Decls) + PDiag << VD->getDeclName(); + } + + for (auto Range : Ranges) + PDiag << Range; + + S.Diag(Ranges.begin()->getBegin(), PDiag); + } + + // If Statement is an incemement or decrement, return true and sets the + // variables Increment and DRE. + bool ProcessIterationStmt(Sema &S, Stmt* Statement, bool &Increment, + DeclRefExpr *&DRE) { + if (auto Cleanups = dyn_cast<ExprWithCleanups>(Statement)) + if (!Cleanups->cleanupsHaveSideEffects()) + Statement = Cleanups->getSubExpr(); + + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(Statement)) { + switch (UO->getOpcode()) { + default: return false; + case UO_PostInc: + case UO_PreInc: + Increment = true; + break; + case UO_PostDec: + case UO_PreDec: + Increment = false; + break; + } + DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr()); + return DRE; + } + + if (CXXOperatorCallExpr *Call = dyn_cast<CXXOperatorCallExpr>(Statement)) { + FunctionDecl *FD = Call->getDirectCallee(); + if (!FD || !FD->isOverloadedOperator()) return false; + switch (FD->getOverloadedOperator()) { + default: return false; + case OO_PlusPlus: + Increment = true; + break; + case OO_MinusMinus: + Increment = false; + break; + } + DRE = dyn_cast<DeclRefExpr>(Call->getArg(0)); + return DRE; + } + + return false; + } + + // A visitor to determine if a continue or break statement is a + // subexpression. + class BreakContinueFinder : public ConstEvaluatedExprVisitor<BreakContinueFinder> { + SourceLocation BreakLoc; + SourceLocation ContinueLoc; + bool InSwitch = false; + + public: + BreakContinueFinder(Sema &S, const Stmt* Body) : + Inherited(S.Context) { + Visit(Body); + } + + typedef ConstEvaluatedExprVisitor<BreakContinueFinder> Inherited; + + void VisitContinueStmt(const ContinueStmt* E) { + ContinueLoc = E->getContinueLoc(); + } + + void VisitBreakStmt(const BreakStmt* E) { + if (!InSwitch) + BreakLoc = E->getBreakLoc(); + } + + void VisitSwitchStmt(const SwitchStmt* S) { + if (const Stmt *Init = S->getInit()) + Visit(Init); + if (const Stmt *CondVar = S->getConditionVariableDeclStmt()) + Visit(CondVar); + if (const Stmt *Cond = S->getCond()) + Visit(Cond); + + // Don't return break statements from the body of a switch. + InSwitch = true; + if (const Stmt *Body = S->getBody()) + Visit(Body); + InSwitch = false; + } + + void VisitForStmt(const ForStmt *S) { + // Only visit the init statement of a for loop; the body + // has a different break/continue scope. + if (const Stmt *Init = S->getInit()) + Visit(Init); + } + + void VisitWhileStmt(const WhileStmt *) { + // Do nothing; the children of a while loop have a different + // break/continue scope. + } + + void VisitDoStmt(const DoStmt *) { + // Do nothing; the children of a while loop have a different + // break/continue scope. + } + + void VisitCXXForRangeStmt(const CXXForRangeStmt *S) { + // Only visit the initialization of a for loop; the body + // has a different break/continue scope. + if (const Stmt *Init = S->getInit()) + Visit(Init); + if (const Stmt *Range = S->getRangeStmt()) + Visit(Range); + if (const Stmt *Begin = S->getBeginStmt()) + Visit(Begin); + if (const Stmt *End = S->getEndStmt()) + Visit(End); + } + + void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) { + // Only visit the initialization of a for loop; the body + // has a different break/continue scope. + if (const Stmt *Element = S->getElement()) + Visit(Element); + if (const Stmt *Collection = S->getCollection()) + Visit(Collection); + } + + bool ContinueFound() { return ContinueLoc.isValid(); } + bool BreakFound() { return BreakLoc.isValid(); } + SourceLocation GetContinueLoc() { return ContinueLoc; } + SourceLocation GetBreakLoc() { return BreakLoc; } + + }; // end class BreakContinueFinder + + // Emit a warning when a loop increment/decrement appears twice per loop + // iteration. The conditions which trigger this warning are: + // 1) The last statement in the loop body and the third expression in the + // for loop are both increment or both decrement of the same variable + // 2) No continue statements in the loop body. + void CheckForRedundantIteration(Sema &S, Expr *Third, Stmt *Body) { + // Return when there is nothing to check. + if (!Body || !Third) return; + + if (S.Diags.isIgnored(diag::warn_redundant_loop_iteration, + Third->getBeginLoc())) + return; + + // Get the last statement from the loop body. + CompoundStmt *CS = dyn_cast<CompoundStmt>(Body); + if (!CS || CS->body_empty()) return; + Stmt *LastStmt = CS->body_back(); + if (!LastStmt) return; + + bool LoopIncrement, LastIncrement; + DeclRefExpr *LoopDRE, *LastDRE; + + if (!ProcessIterationStmt(S, Third, LoopIncrement, LoopDRE)) return; + if (!ProcessIterationStmt(S, LastStmt, LastIncrement, LastDRE)) return; + + // Check that the two statements are both increments or both decrements + // on the same variable. + if (LoopIncrement != LastIncrement || + LoopDRE->getDecl() != LastDRE->getDecl()) return; + + if (BreakContinueFinder(S, Body).ContinueFound()) return; + + S.Diag(LastDRE->getLocation(), diag::warn_redundant_loop_iteration) + << LastDRE->getDecl() << LastIncrement; + S.Diag(LoopDRE->getLocation(), diag::note_loop_iteration_here) + << LoopIncrement; + } + +} // end namespace + + +void Sema::CheckBreakContinueBinding(Expr *E) { + if (!E || getLangOpts().CPlusPlus) + return; + BreakContinueFinder BCFinder(*this, E); + Scope *BreakParent = CurScope->getBreakParent(); + if (BCFinder.BreakFound() && BreakParent) { + if (BreakParent->getFlags() & Scope::SwitchScope) { + Diag(BCFinder.GetBreakLoc(), diag::warn_break_binds_to_switch); + } else { + Diag(BCFinder.GetBreakLoc(), diag::warn_loop_ctrl_binds_to_inner) + << "break"; + } + } else if (BCFinder.ContinueFound() && CurScope->getContinueParent()) { + Diag(BCFinder.GetContinueLoc(), diag::warn_loop_ctrl_binds_to_inner) + << "continue"; + } +} + +StmtResult Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, + Stmt *First, ConditionResult Second, + FullExprArg third, SourceLocation RParenLoc, + Stmt *Body) { + if (Second.isInvalid()) + return StmtError(); + + if (!getLangOpts().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 (auto *DI : DS->decls()) { + VarDecl *VD = dyn_cast<VarDecl>(DI); + if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) + VD = nullptr; + if (!VD) { + Diag(DI->getLocation(), diag::err_non_local_variable_decl_in_for); + DI->setInvalidDecl(); + } + } + } + } + + CheckBreakContinueBinding(Second.get().second); + CheckBreakContinueBinding(third.get()); + + if (!Second.get().first) + CheckForLoopConditionalStatement(*this, Second.get().second, third.get(), + Body); + CheckForRedundantIteration(*this, third.get(), Body); + + if (Second.get().second && + !Diags.isIgnored(diag::warn_comma_operator, + Second.get().second->getExprLoc())) + CommaVisitor(*this).Visit(Second.get().second); + + Expr *Third = third.release().getAs<Expr>(); + if (isa<NullStmt>(Body)) + getCurCompoundScope().setHasEmptyLoopBodies(); + + return new (Context) + ForStmt(Context, First, Second.get().second, Second.get().first, Third, + Body, ForLoc, LParenLoc, RParenLoc); +} + +/// In an Objective C collection iteration statement: +/// for (x in y) +/// x can be an arbitrary l-value expression. Bind it up as a +/// full-expression. +StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { + // Reduce placeholder expressions here. Note that this rejects the + // use of pseudo-object l-values in this position. + ExprResult result = CheckPlaceholderExpr(E); + if (result.isInvalid()) return StmtError(); + E = result.get(); + + ExprResult FullExpr = ActOnFinishFullExpr(E, /*DiscardedValue*/ false); + if (FullExpr.isInvalid()) + return StmtError(); + return StmtResult(static_cast<Stmt*>(FullExpr.get())); +} + +ExprResult +Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { + if (!collection) + return ExprError(); + + ExprResult result = CorrectDelayedTyposInExpr(collection); + if (!result.isUsable()) + return ExprError(); + collection = result.get(); + + // Bail out early if we've got a type-dependent expression. + if (collection->isTypeDependent()) return collection; + + // Perform normal l-value conversion. + result = DefaultFunctionArrayLvalueConversion(collection); + if (result.isInvalid()) + return ExprError(); + collection = result.get(); + + // The operand needs to have object-pointer type. + // TODO: should we do a contextual conversion? + const ObjCObjectPointerType *pointerType = + collection->getType()->getAs<ObjCObjectPointerType>(); + if (!pointerType) + return Diag(forLoc, diag::err_collection_expr_type) + << collection->getType() << collection->getSourceRange(); + + // Check that the operand provides + // - countByEnumeratingWithState:objects:count: + const ObjCObjectType *objectType = pointerType->getObjectType(); + ObjCInterfaceDecl *iface = objectType->getInterface(); + + // If we have a forward-declared type, we can't do this check. + // Under ARC, it is an error not to have a forward-declared class. + if (iface && + (getLangOpts().ObjCAutoRefCount + ? RequireCompleteType(forLoc, QualType(objectType, 0), + diag::err_arc_collection_forward, collection) + : !isCompleteType(forLoc, QualType(objectType, 0)))) { + // Otherwise, if we have any useful type information, check that + // the type declares the appropriate method. + } else if (iface || !objectType->qual_empty()) { + IdentifierInfo *selectorIdents[] = { + &Context.Idents.get("countByEnumeratingWithState"), + &Context.Idents.get("objects"), + &Context.Idents.get("count") + }; + Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); + + ObjCMethodDecl *method = nullptr; + + // If there's an interface, look in both the public and private APIs. + if (iface) { + method = iface->lookupInstanceMethod(selector); + if (!method) method = iface->lookupPrivateMethod(selector); + } + + // Also check protocol qualifiers. + if (!method) + method = LookupMethodInQualifiedType(selector, pointerType, + /*instance*/ true); + + // If we didn't find it anywhere, give up. + if (!method) { + Diag(forLoc, diag::warn_collection_expr_type) + << collection->getType() << selector << collection->getSourceRange(); + } + + // TODO: check for an incompatible signature? + } + + // Wrap up any cleanups in the expression. + return collection; +} + +StmtResult +Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, + Stmt *First, Expr *collection, + SourceLocation RParenLoc) { + setFunctionHasBranchProtectedScope(); + + ExprResult CollectionExprResult = + CheckObjCForCollectionOperand(ForLoc, collection); + + 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)); + + VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl()); + if (!D || D->isInvalidDecl()) + return StmtError(); + + FirstType = 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'. + if (!D->hasLocalStorage()) + return StmtError(Diag(D->getLocation(), + diag::err_non_local_variable_decl_in_for)); + + // If the type contained 'auto', deduce the 'auto' to 'id'. + if (FirstType->getContainedAutoType()) { + OpaqueValueExpr OpaqueId(D->getLocation(), Context.getObjCIdType(), + VK_RValue); + Expr *DeducedInit = &OpaqueId; + if (DeduceAutoType(D->getTypeSourceInfo(), DeducedInit, FirstType) == + DAR_Failed) + DiagnoseAutoDeductionFailure(D, DeducedInit); + if (FirstType.isNull()) { + D->setInvalidDecl(); + return StmtError(); + } + + D->setType(FirstType); + + if (!inTemplateInstantiation()) { + SourceLocation Loc = + D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(); + Diag(Loc, diag::warn_auto_var_is_id) + << D->getDeclName(); + } + } + + } else { + Expr *FirstE = cast<Expr>(First); + if (!FirstE->isTypeDependent() && !FirstE->isLValue()) + return StmtError( + Diag(First->getBeginLoc(), diag::err_selector_element_not_lvalue) + << First->getSourceRange()); + + FirstType = static_cast<Expr*>(First)->getType(); + if (FirstType.isConstQualified()) + Diag(ForLoc, diag::err_selector_element_const_type) + << FirstType << First->getSourceRange(); + } + if (!FirstType->isDependentType() && + !FirstType->isObjCObjectPointerType() && + !FirstType->isBlockPointerType()) + return StmtError(Diag(ForLoc, diag::err_selector_element_type) + << FirstType << First->getSourceRange()); + } + + if (CollectionExprResult.isInvalid()) + return StmtError(); + + CollectionExprResult = + ActOnFinishFullExpr(CollectionExprResult.get(), /*DiscardedValue*/ false); + if (CollectionExprResult.isInvalid()) + return StmtError(); + + return new (Context) ObjCForCollectionStmt(First, CollectionExprResult.get(), + nullptr, ForLoc, RParenLoc); +} + +/// Finish building a variable declaration for a for-range statement. +/// \return true if an error occurs. +static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, + SourceLocation Loc, int DiagID) { + if (Decl->getType()->isUndeducedType()) { + ExprResult Res = SemaRef.CorrectDelayedTyposInExpr(Init); + if (!Res.isUsable()) { + Decl->setInvalidDecl(); + return true; + } + Init = Res.get(); + } + + // Deduce the type for the iterator variable now rather than leaving it to + // AddInitializerToDecl, so we can produce a more suitable diagnostic. + QualType InitType; + if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || + SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitType) == + Sema::DAR_Failed) + SemaRef.Diag(Loc, DiagID) << Init->getType(); + if (InitType.isNull()) { + Decl->setInvalidDecl(); + return true; + } + Decl->setType(InitType); + + // In ARC, infer lifetime. + // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if + // we're doing the equivalent of fast iteration. + if (SemaRef.getLangOpts().ObjCAutoRefCount && + SemaRef.inferObjCARCLifetime(Decl)) + Decl->setInvalidDecl(); + + SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false); + SemaRef.FinalizeDeclaration(Decl); + SemaRef.CurContext->addHiddenDecl(Decl); + return false; +} + +namespace { +// An enum to represent whether something is dealing with a call to begin() +// or a call to end() in a range-based for loop. +enum BeginEndFunction { + BEF_begin, + BEF_end +}; + +/// Produce a note indicating which begin/end function was implicitly called +/// by a C++11 for-range statement. This is often not obvious from the code, +/// nor from the diagnostics produced when analysing the implicit expressions +/// required in a for-range statement. +void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, + BeginEndFunction BEF) { + CallExpr *CE = dyn_cast<CallExpr>(E); + if (!CE) + return; + FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); + if (!D) + return; + SourceLocation Loc = D->getLocation(); + + std::string Description; + bool IsTemplate = false; + if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { + Description = SemaRef.getTemplateArgumentBindingsText( + FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); + IsTemplate = true; + } + + SemaRef.Diag(Loc, diag::note_for_range_begin_end) + << BEF << IsTemplate << Description << E->getType(); +} + +/// Build a variable declaration for a for-range statement. +VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, + QualType Type, StringRef Name) { + DeclContext *DC = SemaRef.CurContext; + IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); + TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); + VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, + TInfo, SC_None); + Decl->setImplicit(); + return Decl; +} + +} + +static bool ObjCEnumerationCollection(Expr *Collection) { + return !Collection->isTypeDependent() + && Collection->getType()->getAs<ObjCObjectPointerType>() != nullptr; +} + +/// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement. +/// +/// C++11 [stmt.ranged]: +/// A range-based for statement is equivalent to +/// +/// { +/// auto && __range = range-init; +/// for ( auto __begin = begin-expr, +/// __end = end-expr; +/// __begin != __end; +/// ++__begin ) { +/// for-range-declaration = *__begin; +/// statement +/// } +/// } +/// +/// The body of the loop is not available yet, since it cannot be analysed until +/// we have determined the type of the for-range-declaration. +StmtResult Sema::ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc, + SourceLocation CoawaitLoc, Stmt *InitStmt, + Stmt *First, SourceLocation ColonLoc, + Expr *Range, SourceLocation RParenLoc, + BuildForRangeKind Kind) { + if (!First) + return StmtError(); + + if (Range && ObjCEnumerationCollection(Range)) { + // FIXME: Support init-statements in Objective-C++20 ranged for statement. + if (InitStmt) + return Diag(InitStmt->getBeginLoc(), diag::err_objc_for_range_init_stmt) + << InitStmt->getSourceRange(); + return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc); + } + + DeclStmt *DS = dyn_cast<DeclStmt>(First); + assert(DS && "first part of for range not a decl stmt"); + + if (!DS->isSingleDecl()) { + Diag(DS->getBeginLoc(), diag::err_type_defined_in_for_range); + return StmtError(); + } + + Decl *LoopVar = DS->getSingleDecl(); + if (LoopVar->isInvalidDecl() || !Range || + DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + // Build the coroutine state immediately and not later during template + // instantiation + if (!CoawaitLoc.isInvalid()) { + if (!ActOnCoroutineBodyStart(S, CoawaitLoc, "co_await")) + return StmtError(); + } + + // Build auto && __range = range-init + // Divide by 2, since the variables are in the inner scope (loop body). + const auto DepthStr = std::to_string(S->getDepth() / 2); + SourceLocation RangeLoc = Range->getBeginLoc(); + VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, + Context.getAutoRRefDeductType(), + std::string("__range") + DepthStr); + if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, + diag::err_for_range_deduction_failure)) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + // Claim the type doesn't contain auto: we've already done the checking. + DeclGroupPtrTy RangeGroup = + BuildDeclaratorGroup(MutableArrayRef<Decl *>((Decl **)&RangeVar, 1)); + StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); + if (RangeDecl.isInvalid()) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + return BuildCXXForRangeStmt( + ForLoc, CoawaitLoc, InitStmt, ColonLoc, RangeDecl.get(), + /*BeginStmt=*/nullptr, /*EndStmt=*/nullptr, + /*Cond=*/nullptr, /*Inc=*/nullptr, DS, RParenLoc, Kind); +} + +/// Create the initialization, compare, and increment steps for +/// the range-based for loop expression. +/// This function does not handle array-based for loops, +/// which are created in Sema::BuildCXXForRangeStmt. +/// +/// \returns a ForRangeStatus indicating success or what kind of error occurred. +/// BeginExpr and EndExpr are set and FRS_Success is returned on success; +/// CandidateSet and BEF are set and some non-success value is returned on +/// failure. +static Sema::ForRangeStatus +BuildNonArrayForRange(Sema &SemaRef, Expr *BeginRange, Expr *EndRange, + QualType RangeType, VarDecl *BeginVar, VarDecl *EndVar, + SourceLocation ColonLoc, SourceLocation CoawaitLoc, + OverloadCandidateSet *CandidateSet, ExprResult *BeginExpr, + ExprResult *EndExpr, BeginEndFunction *BEF) { + DeclarationNameInfo BeginNameInfo( + &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc); + DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"), + ColonLoc); + + LookupResult BeginMemberLookup(SemaRef, BeginNameInfo, + Sema::LookupMemberName); + LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName); + + auto BuildBegin = [&] { + *BEF = BEF_begin; + Sema::ForRangeStatus RangeStatus = + SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, BeginNameInfo, + BeginMemberLookup, CandidateSet, + BeginRange, BeginExpr); + + if (RangeStatus != Sema::FRS_Success) { + if (RangeStatus == Sema::FRS_DiagnosticIssued) + SemaRef.Diag(BeginRange->getBeginLoc(), diag::note_in_for_range) + << ColonLoc << BEF_begin << BeginRange->getType(); + return RangeStatus; + } + if (!CoawaitLoc.isInvalid()) { + // FIXME: getCurScope() should not be used during template instantiation. + // We should pick up the set of unqualified lookup results for operator + // co_await during the initial parse. + *BeginExpr = SemaRef.ActOnCoawaitExpr(SemaRef.getCurScope(), ColonLoc, + BeginExpr->get()); + if (BeginExpr->isInvalid()) + return Sema::FRS_DiagnosticIssued; + } + if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + return Sema::FRS_Success; + }; + + auto BuildEnd = [&] { + *BEF = BEF_end; + Sema::ForRangeStatus RangeStatus = + SemaRef.BuildForRangeBeginEndCall(ColonLoc, ColonLoc, EndNameInfo, + EndMemberLookup, CandidateSet, + EndRange, EndExpr); + if (RangeStatus != Sema::FRS_Success) { + if (RangeStatus == Sema::FRS_DiagnosticIssued) + SemaRef.Diag(EndRange->getBeginLoc(), diag::note_in_for_range) + << ColonLoc << BEF_end << EndRange->getType(); + return RangeStatus; + } + if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + return Sema::FRS_Success; + }; + + if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { + // - if _RangeT is a class type, the unqualified-ids begin and end are + // looked up in the scope of class _RangeT as if by class member access + // lookup (3.4.5), and if either (or both) finds at least one + // declaration, begin-expr and end-expr are __range.begin() and + // __range.end(), respectively; + SemaRef.LookupQualifiedName(BeginMemberLookup, D); + if (BeginMemberLookup.isAmbiguous()) + return Sema::FRS_DiagnosticIssued; + + SemaRef.LookupQualifiedName(EndMemberLookup, D); + if (EndMemberLookup.isAmbiguous()) + return Sema::FRS_DiagnosticIssued; + + if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { + // Look up the non-member form of the member we didn't find, first. + // This way we prefer a "no viable 'end'" diagnostic over a "i found + // a 'begin' but ignored it because there was no member 'end'" + // diagnostic. + auto BuildNonmember = [&]( + BeginEndFunction BEFFound, LookupResult &Found, + llvm::function_ref<Sema::ForRangeStatus()> BuildFound, + llvm::function_ref<Sema::ForRangeStatus()> BuildNotFound) { + LookupResult OldFound = std::move(Found); + Found.clear(); + + if (Sema::ForRangeStatus Result = BuildNotFound()) + return Result; + + switch (BuildFound()) { + case Sema::FRS_Success: + return Sema::FRS_Success; + + case Sema::FRS_NoViableFunction: + CandidateSet->NoteCandidates( + PartialDiagnosticAt(BeginRange->getBeginLoc(), + SemaRef.PDiag(diag::err_for_range_invalid) + << BeginRange->getType() << BEFFound), + SemaRef, OCD_AllCandidates, BeginRange); + LLVM_FALLTHROUGH; + + case Sema::FRS_DiagnosticIssued: + for (NamedDecl *D : OldFound) { + SemaRef.Diag(D->getLocation(), + diag::note_for_range_member_begin_end_ignored) + << BeginRange->getType() << BEFFound; + } + return Sema::FRS_DiagnosticIssued; + } + llvm_unreachable("unexpected ForRangeStatus"); + }; + if (BeginMemberLookup.empty()) + return BuildNonmember(BEF_end, EndMemberLookup, BuildEnd, BuildBegin); + return BuildNonmember(BEF_begin, BeginMemberLookup, BuildBegin, BuildEnd); + } + } else { + // - otherwise, begin-expr and end-expr are begin(__range) and + // end(__range), respectively, where begin and end are looked up with + // argument-dependent lookup (3.4.2). For the purposes of this name + // lookup, namespace std is an associated namespace. + } + + if (Sema::ForRangeStatus Result = BuildBegin()) + return Result; + return BuildEnd(); +} + +/// Speculatively attempt to dereference an invalid range expression. +/// If the attempt fails, this function will return a valid, null StmtResult +/// and emit no diagnostics. +static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S, + SourceLocation ForLoc, + SourceLocation CoawaitLoc, + Stmt *InitStmt, + Stmt *LoopVarDecl, + SourceLocation ColonLoc, + Expr *Range, + SourceLocation RangeLoc, + SourceLocation RParenLoc) { + // Determine whether we can rebuild the for-range statement with a + // dereferenced range expression. + ExprResult AdjustedRange; + { + Sema::SFINAETrap Trap(SemaRef); + + AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range); + if (AdjustedRange.isInvalid()) + return StmtResult(); + + StmtResult SR = SemaRef.ActOnCXXForRangeStmt( + S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc, + AdjustedRange.get(), RParenLoc, Sema::BFRK_Check); + if (SR.isInvalid()) + return StmtResult(); + } + + // The attempt to dereference worked well enough that it could produce a valid + // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in + // case there are any other (non-fatal) problems with it. + SemaRef.Diag(RangeLoc, diag::err_for_range_dereference) + << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*"); + return SemaRef.ActOnCXXForRangeStmt( + S, ForLoc, CoawaitLoc, InitStmt, LoopVarDecl, ColonLoc, + AdjustedRange.get(), RParenLoc, Sema::BFRK_Rebuild); +} + +namespace { +/// RAII object to automatically invalidate a declaration if an error occurs. +struct InvalidateOnErrorScope { + InvalidateOnErrorScope(Sema &SemaRef, Decl *D, bool Enabled) + : Trap(SemaRef.Diags), D(D), Enabled(Enabled) {} + ~InvalidateOnErrorScope() { + if (Enabled && Trap.hasErrorOccurred()) + D->setInvalidDecl(); + } + + DiagnosticErrorTrap Trap; + Decl *D; + bool Enabled; +}; +} + +/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement. +StmtResult Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, + SourceLocation CoawaitLoc, Stmt *InitStmt, + SourceLocation ColonLoc, Stmt *RangeDecl, + Stmt *Begin, Stmt *End, Expr *Cond, + Expr *Inc, Stmt *LoopVarDecl, + SourceLocation RParenLoc, + BuildForRangeKind Kind) { + // FIXME: This should not be used during template instantiation. We should + // pick up the set of unqualified lookup results for the != and + operators + // in the initial parse. + // + // Testcase (accepts-invalid): + // template<typename T> void f() { for (auto x : T()) {} } + // namespace N { struct X { X begin(); X end(); int operator*(); }; } + // bool operator!=(N::X, N::X); void operator++(N::X); + // void g() { f<N::X>(); } + Scope *S = getCurScope(); + + DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); + VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); + QualType RangeVarType = RangeVar->getType(); + + DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); + VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); + + // If we hit any errors, mark the loop variable as invalid if its type + // contains 'auto'. + InvalidateOnErrorScope Invalidate(*this, LoopVar, + LoopVar->getType()->isUndeducedType()); + + StmtResult BeginDeclStmt = Begin; + StmtResult EndDeclStmt = End; + ExprResult NotEqExpr = Cond, IncrExpr = Inc; + + if (RangeVarType->isDependentType()) { + // The range is implicitly used as a placeholder when it is dependent. + RangeVar->markUsed(Context); + + // Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill + // them in properly when we instantiate the loop. + if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) { + if (auto *DD = dyn_cast<DecompositionDecl>(LoopVar)) + for (auto *Binding : DD->bindings()) + Binding->setType(Context.DependentTy); + LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy)); + } + } else if (!BeginDeclStmt.get()) { + SourceLocation RangeLoc = RangeVar->getLocation(); + + const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); + + ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, + VK_LValue, ColonLoc); + if (BeginRangeRef.isInvalid()) + return StmtError(); + + ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, + VK_LValue, ColonLoc); + if (EndRangeRef.isInvalid()) + return StmtError(); + + QualType AutoType = Context.getAutoDeductType(); + Expr *Range = RangeVar->getInit(); + if (!Range) + return StmtError(); + QualType RangeType = Range->getType(); + + if (RequireCompleteType(RangeLoc, RangeType, + diag::err_for_range_incomplete_type)) + return StmtError(); + + // Build auto __begin = begin-expr, __end = end-expr. + // Divide by 2, since the variables are in the inner scope (loop body). + const auto DepthStr = std::to_string(S->getDepth() / 2); + VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, + std::string("__begin") + DepthStr); + VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, + std::string("__end") + DepthStr); + + // Build begin-expr and end-expr and attach to __begin and __end variables. + ExprResult BeginExpr, EndExpr; + if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { + // - if _RangeT is an array type, begin-expr and end-expr are __range and + // __range + __bound, respectively, where __bound is the array bound. If + // _RangeT is an array of unknown size or an array of incomplete type, + // the program is ill-formed; + + // begin-expr is __range. + BeginExpr = BeginRangeRef; + if (!CoawaitLoc.isInvalid()) { + BeginExpr = ActOnCoawaitExpr(S, ColonLoc, BeginExpr.get()); + if (BeginExpr.isInvalid()) + return StmtError(); + } + if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Find the array bound. + ExprResult BoundExpr; + if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) + BoundExpr = IntegerLiteral::Create( + Context, CAT->getSize(), Context.getPointerDiffType(), RangeLoc); + else if (const VariableArrayType *VAT = + dyn_cast<VariableArrayType>(UnqAT)) { + // For a variably modified type we can't just use the expression within + // the array bounds, since we don't want that to be re-evaluated here. + // Rather, we need to determine what it was when the array was first + // created - so we resort to using sizeof(vla)/sizeof(element). + // For e.g. + // void f(int b) { + // int vla[b]; + // b = -1; <-- This should not affect the num of iterations below + // for (int &c : vla) { .. } + // } + + // FIXME: This results in codegen generating IR that recalculates the + // run-time number of elements (as opposed to just using the IR Value + // that corresponds to the run-time value of each bound that was + // generated when the array was created.) If this proves too embarrassing + // even for unoptimized IR, consider passing a magic-value/cookie to + // codegen that then knows to simply use that initial llvm::Value (that + // corresponds to the bound at time of array creation) within + // getelementptr. But be prepared to pay the price of increasing a + // customized form of coupling between the two components - which could + // be hard to maintain as the codebase evolves. + + ExprResult SizeOfVLAExprR = ActOnUnaryExprOrTypeTraitExpr( + EndVar->getLocation(), UETT_SizeOf, + /*IsType=*/true, + CreateParsedType(VAT->desugar(), Context.getTrivialTypeSourceInfo( + VAT->desugar(), RangeLoc)) + .getAsOpaquePtr(), + EndVar->getSourceRange()); + if (SizeOfVLAExprR.isInvalid()) + return StmtError(); + + ExprResult SizeOfEachElementExprR = ActOnUnaryExprOrTypeTraitExpr( + EndVar->getLocation(), UETT_SizeOf, + /*IsType=*/true, + CreateParsedType(VAT->desugar(), + Context.getTrivialTypeSourceInfo( + VAT->getElementType(), RangeLoc)) + .getAsOpaquePtr(), + EndVar->getSourceRange()); + if (SizeOfEachElementExprR.isInvalid()) + return StmtError(); + + BoundExpr = + ActOnBinOp(S, EndVar->getLocation(), tok::slash, + SizeOfVLAExprR.get(), SizeOfEachElementExprR.get()); + if (BoundExpr.isInvalid()) + return StmtError(); + + } else { + // Can't be a DependentSizedArrayType or an IncompleteArrayType since + // UnqAT is not incomplete and Range is not type-dependent. + llvm_unreachable("Unexpected array type in for-range"); + } + + // end-expr is __range + __bound. + EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), + BoundExpr.get()); + if (EndExpr.isInvalid()) + return StmtError(); + if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + return StmtError(); + } + } else { + OverloadCandidateSet CandidateSet(RangeLoc, + OverloadCandidateSet::CSK_Normal); + BeginEndFunction BEFFailure; + ForRangeStatus RangeStatus = BuildNonArrayForRange( + *this, BeginRangeRef.get(), EndRangeRef.get(), RangeType, BeginVar, + EndVar, ColonLoc, CoawaitLoc, &CandidateSet, &BeginExpr, &EndExpr, + &BEFFailure); + + if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction && + BEFFailure == BEF_begin) { + // If the range is being built from an array parameter, emit a + // a diagnostic that it is being treated as a pointer. + if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) { + if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) { + QualType ArrayTy = PVD->getOriginalType(); + QualType PointerTy = PVD->getType(); + if (PointerTy->isPointerType() && ArrayTy->isArrayType()) { + Diag(Range->getBeginLoc(), diag::err_range_on_array_parameter) + << RangeLoc << PVD << ArrayTy << PointerTy; + Diag(PVD->getLocation(), diag::note_declared_at); + return StmtError(); + } + } + } + + // If building the range failed, try dereferencing the range expression + // unless a diagnostic was issued or the end function is problematic. + StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc, + CoawaitLoc, InitStmt, + LoopVarDecl, ColonLoc, + Range, RangeLoc, + RParenLoc); + if (SR.isInvalid() || SR.isUsable()) + return SR; + } + + // Otherwise, emit diagnostics if we haven't already. + if (RangeStatus == FRS_NoViableFunction) { + Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get(); + CandidateSet.NoteCandidates( + PartialDiagnosticAt(Range->getBeginLoc(), + PDiag(diag::err_for_range_invalid) + << RangeLoc << Range->getType() + << BEFFailure), + *this, OCD_AllCandidates, Range); + } + // Return an error if no fix was discovered. + if (RangeStatus != FRS_Success) + return StmtError(); + } + + assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() && + "invalid range expression in for loop"); + + // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same. + // C++1z removes this restriction. + QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); + if (!Context.hasSameType(BeginType, EndType)) { + Diag(RangeLoc, getLangOpts().CPlusPlus17 + ? diag::warn_for_range_begin_end_types_differ + : diag::ext_for_range_begin_end_types_differ) + << BeginType << EndType; + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + } + + BeginDeclStmt = + ActOnDeclStmt(ConvertDeclToDeclGroup(BeginVar), ColonLoc, ColonLoc); + EndDeclStmt = + ActOnDeclStmt(ConvertDeclToDeclGroup(EndVar), ColonLoc, ColonLoc); + + const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); + ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), + VK_LValue, ColonLoc); + if (EndRef.isInvalid()) + return StmtError(); + + // Build and check __begin != __end expression. + NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, + BeginRef.get(), EndRef.get()); + if (!NotEqExpr.isInvalid()) + NotEqExpr = CheckBooleanCondition(ColonLoc, NotEqExpr.get()); + if (!NotEqExpr.isInvalid()) + NotEqExpr = + ActOnFinishFullExpr(NotEqExpr.get(), /*DiscardedValue*/ false); + if (NotEqExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 0 << BeginRangeRef.get()->getType(); + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + if (!Context.hasSameType(BeginType, EndType)) + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + return StmtError(); + } + + // Build and check ++__begin expression. + BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); + if (!IncrExpr.isInvalid() && CoawaitLoc.isValid()) + // FIXME: getCurScope() should not be used during template instantiation. + // We should pick up the set of unqualified lookup results for operator + // co_await during the initial parse. + IncrExpr = ActOnCoawaitExpr(S, CoawaitLoc, IncrExpr.get()); + if (!IncrExpr.isInvalid()) + IncrExpr = ActOnFinishFullExpr(IncrExpr.get(), /*DiscardedValue*/ false); + if (IncrExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 2 << BeginRangeRef.get()->getType() ; + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Build and check *__begin expression. + BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); + if (DerefExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 1 << BeginRangeRef.get()->getType(); + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Attach *__begin as initializer for VD. Don't touch it if we're just + // trying to determine whether this would be a valid range. + if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) { + AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false); + if (LoopVar->isInvalidDecl()) + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + } + } + + // Don't bother to actually allocate the result if we're just trying to + // determine whether it would be valid. + if (Kind == BFRK_Check) + return StmtResult(); + + // In OpenMP loop region loop control variable must be private. Perform + // analysis of first part (if any). + if (getLangOpts().OpenMP >= 50 && BeginDeclStmt.isUsable()) + ActOnOpenMPLoopInitialization(ForLoc, BeginDeclStmt.get()); + + return new (Context) CXXForRangeStmt( + InitStmt, RangeDS, cast_or_null<DeclStmt>(BeginDeclStmt.get()), + cast_or_null<DeclStmt>(EndDeclStmt.get()), NotEqExpr.get(), + IncrExpr.get(), LoopVarDS, /*Body=*/nullptr, ForLoc, CoawaitLoc, + ColonLoc, RParenLoc); +} + +/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach +/// statement. +StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) { + if (!S || !B) + return StmtError(); + ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S); + + ForStmt->setBody(B); + return S; +} + +// Warn when the loop variable is a const reference that creates a copy. +// Suggest using the non-reference type for copies. If a copy can be prevented +// suggest the const reference type that would do so. +// For instance, given "for (const &Foo : Range)", suggest +// "for (const Foo : Range)" to denote a copy is made for the loop. If +// possible, also suggest "for (const &Bar : Range)" if this type prevents +// the copy altogether. +static void DiagnoseForRangeReferenceVariableCopies(Sema &SemaRef, + const VarDecl *VD, + QualType RangeInitType) { + const Expr *InitExpr = VD->getInit(); + if (!InitExpr) + return; + + QualType VariableType = VD->getType(); + + if (auto Cleanups = dyn_cast<ExprWithCleanups>(InitExpr)) + if (!Cleanups->cleanupsHaveSideEffects()) + InitExpr = Cleanups->getSubExpr(); + + const MaterializeTemporaryExpr *MTE = + dyn_cast<MaterializeTemporaryExpr>(InitExpr); + + // No copy made. + if (!MTE) + return; + + const Expr *E = MTE->GetTemporaryExpr()->IgnoreImpCasts(); + + // Searching for either UnaryOperator for dereference of a pointer or + // CXXOperatorCallExpr for handling iterators. + while (!isa<CXXOperatorCallExpr>(E) && !isa<UnaryOperator>(E)) { + if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(E)) { + E = CCE->getArg(0); + } else if (const CXXMemberCallExpr *Call = dyn_cast<CXXMemberCallExpr>(E)) { + const MemberExpr *ME = cast<MemberExpr>(Call->getCallee()); + E = ME->getBase(); + } else { + const MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(E); + E = MTE->GetTemporaryExpr(); + } + E = E->IgnoreImpCasts(); + } + + bool ReturnsReference = false; + if (isa<UnaryOperator>(E)) { + ReturnsReference = true; + } else { + const CXXOperatorCallExpr *Call = cast<CXXOperatorCallExpr>(E); + const FunctionDecl *FD = Call->getDirectCallee(); + QualType ReturnType = FD->getReturnType(); + ReturnsReference = ReturnType->isReferenceType(); + } + + if (ReturnsReference) { + // Loop variable creates a temporary. Suggest either to go with + // non-reference loop variable to indicate a copy is made, or + // the correct time to bind a const reference. + SemaRef.Diag(VD->getLocation(), diag::warn_for_range_const_reference_copy) + << VD << VariableType << E->getType(); + QualType NonReferenceType = VariableType.getNonReferenceType(); + NonReferenceType.removeLocalConst(); + QualType NewReferenceType = + SemaRef.Context.getLValueReferenceType(E->getType().withConst()); + SemaRef.Diag(VD->getBeginLoc(), diag::note_use_type_or_non_reference) + << NonReferenceType << NewReferenceType << VD->getSourceRange(); + } else { + // The range always returns a copy, so a temporary is always created. + // Suggest removing the reference from the loop variable. + SemaRef.Diag(VD->getLocation(), diag::warn_for_range_variable_always_copy) + << VD << RangeInitType; + QualType NonReferenceType = VariableType.getNonReferenceType(); + NonReferenceType.removeLocalConst(); + SemaRef.Diag(VD->getBeginLoc(), diag::note_use_non_reference_type) + << NonReferenceType << VD->getSourceRange(); + } +} + +// Warns when the loop variable can be changed to a reference type to +// prevent a copy. For instance, if given "for (const Foo x : Range)" suggest +// "for (const Foo &x : Range)" if this form does not make a copy. +static void DiagnoseForRangeConstVariableCopies(Sema &SemaRef, + const VarDecl *VD) { + const Expr *InitExpr = VD->getInit(); + if (!InitExpr) + return; + + QualType VariableType = VD->getType(); + + if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(InitExpr)) { + if (!CE->getConstructor()->isCopyConstructor()) + return; + } else if (const CastExpr *CE = dyn_cast<CastExpr>(InitExpr)) { + if (CE->getCastKind() != CK_LValueToRValue) + return; + } else { + return; + } + + // TODO: Determine a maximum size that a POD type can be before a diagnostic + // should be emitted. Also, only ignore POD types with trivial copy + // constructors. + if (VariableType.isPODType(SemaRef.Context)) + return; + + // Suggest changing from a const variable to a const reference variable + // if doing so will prevent a copy. + SemaRef.Diag(VD->getLocation(), diag::warn_for_range_copy) + << VD << VariableType << InitExpr->getType(); + SemaRef.Diag(VD->getBeginLoc(), diag::note_use_reference_type) + << SemaRef.Context.getLValueReferenceType(VariableType) + << VD->getSourceRange(); +} + +/// DiagnoseForRangeVariableCopies - Diagnose three cases and fixes for them. +/// 1) for (const foo &x : foos) where foos only returns a copy. Suggest +/// using "const foo x" to show that a copy is made +/// 2) for (const bar &x : foos) where bar is a temporary initialized by bar. +/// Suggest either "const bar x" to keep the copying or "const foo& x" to +/// prevent the copy. +/// 3) for (const foo x : foos) where x is constructed from a reference foo. +/// Suggest "const foo &x" to prevent the copy. +static void DiagnoseForRangeVariableCopies(Sema &SemaRef, + const CXXForRangeStmt *ForStmt) { + if (SemaRef.Diags.isIgnored(diag::warn_for_range_const_reference_copy, + ForStmt->getBeginLoc()) && + SemaRef.Diags.isIgnored(diag::warn_for_range_variable_always_copy, + ForStmt->getBeginLoc()) && + SemaRef.Diags.isIgnored(diag::warn_for_range_copy, + ForStmt->getBeginLoc())) { + return; + } + + const VarDecl *VD = ForStmt->getLoopVariable(); + if (!VD) + return; + + QualType VariableType = VD->getType(); + + if (VariableType->isIncompleteType()) + return; + + const Expr *InitExpr = VD->getInit(); + if (!InitExpr) + return; + + if (VariableType->isReferenceType()) { + DiagnoseForRangeReferenceVariableCopies(SemaRef, VD, + ForStmt->getRangeInit()->getType()); + } else if (VariableType.isConstQualified()) { + DiagnoseForRangeConstVariableCopies(SemaRef, VD); + } +} + +/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. +/// This is a separate step from ActOnCXXForRangeStmt because analysis of the +/// body cannot be performed until after the type of the range variable is +/// determined. +StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { + if (!S || !B) + return StmtError(); + + if (isa<ObjCForCollectionStmt>(S)) + return FinishObjCForCollectionStmt(S, B); + + CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); + ForStmt->setBody(B); + + DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, + diag::warn_empty_range_based_for_body); + + DiagnoseForRangeVariableCopies(*this, ForStmt); + + return S; +} + +StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, + SourceLocation LabelLoc, + LabelDecl *TheDecl) { + setFunctionHasBranchIntoScope(); + TheDecl->markUsed(Context); + return new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc); +} + +StmtResult +Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, + Expr *E) { + // Convert operand to void* + if (!E->isTypeDependent()) { + QualType ETy = E->getType(); + QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); + ExprResult ExprRes = E; + AssignConvertType ConvTy = + CheckSingleAssignmentConstraints(DestTy, ExprRes); + if (ExprRes.isInvalid()) + return StmtError(); + E = ExprRes.get(); + if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) + return StmtError(); + } + + ExprResult ExprRes = ActOnFinishFullExpr(E, /*DiscardedValue*/ false); + if (ExprRes.isInvalid()) + return StmtError(); + E = ExprRes.get(); + + setFunctionHasIndirectGoto(); + + return new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E); +} + +static void CheckJumpOutOfSEHFinally(Sema &S, SourceLocation Loc, + const Scope &DestScope) { + if (!S.CurrentSEHFinally.empty() && + DestScope.Contains(*S.CurrentSEHFinally.back())) { + S.Diag(Loc, diag::warn_jump_out_of_seh_finally); + } +} + +StmtResult +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)); + } + CheckJumpOutOfSEHFinally(*this, ContinueLoc, *S); + + return new (Context) ContinueStmt(ContinueLoc); +} + +StmtResult +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)); + } + if (S->isOpenMPLoopScope()) + return StmtError(Diag(BreakLoc, diag::err_omp_loop_cannot_use_stmt) + << "break"); + CheckJumpOutOfSEHFinally(*this, BreakLoc, *S); + + return new (Context) BreakStmt(BreakLoc); +} + +/// Determine whether the given expression is a candidate for +/// copy elision in either a return statement or a throw expression. +/// +/// \param ReturnType If we're determining the copy elision candidate for +/// a return statement, this is the return type of the function. If we're +/// determining the copy elision candidate for a throw expression, this will +/// be a NULL type. +/// +/// \param E The expression being returned from the function or block, or +/// being thrown. +/// +/// \param CESK Whether we allow function parameters or +/// id-expressions that could be moved out of the function to be considered NRVO +/// candidates. C++ prohibits these for NRVO itself, but we re-use this logic to +/// determine whether we should try to move as part of a return or throw (which +/// does allow function parameters). +/// +/// \returns The NRVO candidate variable, if the return statement may use the +/// NRVO, or NULL if there is no such candidate. +VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, Expr *E, + CopyElisionSemanticsKind CESK) { + // - in a return statement in a function [where] ... + // ... the expression is the name of a non-volatile automatic object ... + DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); + if (!DR || DR->refersToEnclosingVariableOrCapture()) + return nullptr; + VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); + if (!VD) + return nullptr; + + if (isCopyElisionCandidate(ReturnType, VD, CESK)) + return VD; + return nullptr; +} + +bool Sema::isCopyElisionCandidate(QualType ReturnType, const VarDecl *VD, + CopyElisionSemanticsKind CESK) { + QualType VDType = VD->getType(); + // - in a return statement in a function with ... + // ... a class return type ... + if (!ReturnType.isNull() && !ReturnType->isDependentType()) { + if (!ReturnType->isRecordType()) + return false; + // ... the same cv-unqualified type as the function return type ... + // When considering moving this expression out, allow dissimilar types. + if (!(CESK & CES_AllowDifferentTypes) && !VDType->isDependentType() && + !Context.hasSameUnqualifiedType(ReturnType, VDType)) + return false; + } + + // ...object (other than a function or catch-clause parameter)... + if (VD->getKind() != Decl::Var && + !((CESK & CES_AllowParameters) && VD->getKind() == Decl::ParmVar)) + return false; + if (!(CESK & CES_AllowExceptionVariables) && VD->isExceptionVariable()) + return false; + + // ...automatic... + if (!VD->hasLocalStorage()) return false; + + // Return false if VD is a __block variable. We don't want to implicitly move + // out of a __block variable during a return because we cannot assume the + // variable will no longer be used. + if (VD->hasAttr<BlocksAttr>()) return false; + + if (CESK & CES_AllowDifferentTypes) + return true; + + // ...non-volatile... + if (VD->getType().isVolatileQualified()) return false; + + // Variables with higher required alignment than their type's ABI + // alignment cannot use NRVO. + if (!VD->getType()->isDependentType() && VD->hasAttr<AlignedAttr>() && + Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) + return false; + + return true; +} + +/// Try to perform the initialization of a potentially-movable value, +/// which is the operand to a return or throw statement. +/// +/// This routine implements C++14 [class.copy]p32, which attempts to treat +/// returned lvalues as rvalues in certain cases (to prefer move construction), +/// then falls back to treating them as lvalues if that failed. +/// +/// \param ConvertingConstructorsOnly If true, follow [class.copy]p32 and reject +/// resolutions that find non-constructors, such as derived-to-base conversions +/// or `operator T()&&` member functions. If false, do consider such +/// conversion sequences. +/// +/// \param Res We will fill this in if move-initialization was possible. +/// If move-initialization is not possible, such that we must fall back to +/// treating the operand as an lvalue, we will leave Res in its original +/// invalid state. +static void TryMoveInitialization(Sema& S, + const InitializedEntity &Entity, + const VarDecl *NRVOCandidate, + QualType ResultType, + Expr *&Value, + bool ConvertingConstructorsOnly, + ExprResult &Res) { + ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, Value->getType(), + CK_NoOp, Value, VK_XValue); + + Expr *InitExpr = &AsRvalue; + + InitializationKind Kind = InitializationKind::CreateCopy( + Value->getBeginLoc(), Value->getBeginLoc()); + + InitializationSequence Seq(S, Entity, Kind, InitExpr); + + if (!Seq) + return; + + for (const InitializationSequence::Step &Step : Seq.steps()) { + if (Step.Kind != InitializationSequence::SK_ConstructorInitialization && + Step.Kind != InitializationSequence::SK_UserConversion) + continue; + + FunctionDecl *FD = Step.Function.Function; + if (ConvertingConstructorsOnly) { + if (isa<CXXConstructorDecl>(FD)) { + // C++14 [class.copy]p32: + // [...] If the first overload resolution fails or was not performed, + // or if the type of the first parameter of the selected constructor + // is not an rvalue reference to the object's type (possibly + // cv-qualified), overload resolution is performed again, considering + // the object as an lvalue. + const RValueReferenceType *RRefType = + FD->getParamDecl(0)->getType()->getAs<RValueReferenceType>(); + if (!RRefType) + break; + if (!S.Context.hasSameUnqualifiedType(RRefType->getPointeeType(), + NRVOCandidate->getType())) + break; + } else { + continue; + } + } else { + if (isa<CXXConstructorDecl>(FD)) { + // Check that overload resolution selected a constructor taking an + // rvalue reference. If it selected an lvalue reference, then we + // didn't need to cast this thing to an rvalue in the first place. + if (!isa<RValueReferenceType>(FD->getParamDecl(0)->getType())) + break; + } else if (isa<CXXMethodDecl>(FD)) { + // Check that overload resolution selected a conversion operator + // taking an rvalue reference. + if (cast<CXXMethodDecl>(FD)->getRefQualifier() != RQ_RValue) + break; + } else { + continue; + } + } + + // Promote "AsRvalue" to the heap, since we now need this + // expression node to persist. + Value = ImplicitCastExpr::Create(S.Context, Value->getType(), CK_NoOp, + Value, nullptr, VK_XValue); + + // Complete type-checking the initialization of the return type + // using the constructor we found. + Res = Seq.Perform(S, Entity, Kind, Value); + } +} + +/// Perform the initialization of a potentially-movable value, which +/// is the result of return value. +/// +/// This routine implements C++14 [class.copy]p32, which attempts to treat +/// returned lvalues as rvalues in certain cases (to prefer move construction), +/// then falls back to treating them as lvalues if that failed. +ExprResult +Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, + const VarDecl *NRVOCandidate, + QualType ResultType, + Expr *Value, + bool AllowNRVO) { + // C++14 [class.copy]p32: + // When the criteria for elision of a copy/move operation are met, but not for + // an exception-declaration, and the object to be copied is designated by an + // lvalue, or when the expression in a return statement is a (possibly + // parenthesized) id-expression that names an object with automatic storage + // duration declared in the body or parameter-declaration-clause of the + // innermost enclosing function or lambda-expression, overload resolution to + // select the constructor for the copy is first performed as if the object + // were designated by an rvalue. + ExprResult Res = ExprError(); + + if (AllowNRVO) { + bool AffectedByCWG1579 = false; + + if (!NRVOCandidate) { + NRVOCandidate = getCopyElisionCandidate(ResultType, Value, CES_Default); + if (NRVOCandidate && + !getDiagnostics().isIgnored(diag::warn_return_std_move_in_cxx11, + Value->getExprLoc())) { + const VarDecl *NRVOCandidateInCXX11 = + getCopyElisionCandidate(ResultType, Value, CES_FormerDefault); + AffectedByCWG1579 = (!NRVOCandidateInCXX11); + } + } + + if (NRVOCandidate) { + TryMoveInitialization(*this, Entity, NRVOCandidate, ResultType, Value, + true, Res); + } + + if (!Res.isInvalid() && AffectedByCWG1579) { + QualType QT = NRVOCandidate->getType(); + if (QT.getNonReferenceType() + .getUnqualifiedType() + .isTriviallyCopyableType(Context)) { + // Adding 'std::move' around a trivially copyable variable is probably + // pointless. Don't suggest it. + } else { + // Common cases for this are returning unique_ptr<Derived> from a + // function of return type unique_ptr<Base>, or returning T from a + // function of return type Expected<T>. This is totally fine in a + // post-CWG1579 world, but was not fine before. + assert(!ResultType.isNull()); + SmallString<32> Str; + Str += "std::move("; + Str += NRVOCandidate->getDeclName().getAsString(); + Str += ")"; + Diag(Value->getExprLoc(), diag::warn_return_std_move_in_cxx11) + << Value->getSourceRange() + << NRVOCandidate->getDeclName() << ResultType << QT; + Diag(Value->getExprLoc(), diag::note_add_std_move_in_cxx11) + << FixItHint::CreateReplacement(Value->getSourceRange(), Str); + } + } else if (Res.isInvalid() && + !getDiagnostics().isIgnored(diag::warn_return_std_move, + Value->getExprLoc())) { + const VarDecl *FakeNRVOCandidate = + getCopyElisionCandidate(QualType(), Value, CES_AsIfByStdMove); + if (FakeNRVOCandidate) { + QualType QT = FakeNRVOCandidate->getType(); + if (QT->isLValueReferenceType()) { + // Adding 'std::move' around an lvalue reference variable's name is + // dangerous. Don't suggest it. + } else if (QT.getNonReferenceType() + .getUnqualifiedType() + .isTriviallyCopyableType(Context)) { + // Adding 'std::move' around a trivially copyable variable is probably + // pointless. Don't suggest it. + } else { + ExprResult FakeRes = ExprError(); + Expr *FakeValue = Value; + TryMoveInitialization(*this, Entity, FakeNRVOCandidate, ResultType, + FakeValue, false, FakeRes); + if (!FakeRes.isInvalid()) { + bool IsThrow = + (Entity.getKind() == InitializedEntity::EK_Exception); + SmallString<32> Str; + Str += "std::move("; + Str += FakeNRVOCandidate->getDeclName().getAsString(); + Str += ")"; + Diag(Value->getExprLoc(), diag::warn_return_std_move) + << Value->getSourceRange() + << FakeNRVOCandidate->getDeclName() << IsThrow; + Diag(Value->getExprLoc(), diag::note_add_std_move) + << FixItHint::CreateReplacement(Value->getSourceRange(), Str); + } + } + } + } + } + + // Either we didn't meet the criteria for treating an lvalue as an rvalue, + // above, or overload resolution failed. Either way, we need to try + // (again) now with the return value expression as written. + if (Res.isInvalid()) + Res = PerformCopyInitialization(Entity, SourceLocation(), Value); + + return Res; +} + +/// Determine whether the declared return type of the specified function +/// contains 'auto'. +static bool hasDeducedReturnType(FunctionDecl *FD) { + const FunctionProtoType *FPT = + FD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>(); + return FPT->getReturnType()->isUndeducedType(); +} + +/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements +/// for capturing scopes. +/// +StmtResult +Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { + // If this is the first return we've seen, infer the return type. + // [expr.prim.lambda]p4 in C++11; block literals follow the same rules. + CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); + QualType FnRetType = CurCap->ReturnType; + LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap); + bool HasDeducedReturnType = + CurLambda && hasDeducedReturnType(CurLambda->CallOperator); + + if (ExprEvalContexts.back().Context == + ExpressionEvaluationContext::DiscardedStatement && + (HasDeducedReturnType || CurCap->HasImplicitReturnType)) { + if (RetValExp) { + ExprResult ER = + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.get(); + } + return ReturnStmt::Create(Context, ReturnLoc, RetValExp, + /* NRVOCandidate=*/nullptr); + } + + if (HasDeducedReturnType) { + // In C++1y, the return type may involve 'auto'. + // FIXME: Blocks might have a return type of 'auto' explicitly specified. + FunctionDecl *FD = CurLambda->CallOperator; + if (CurCap->ReturnType.isNull()) + CurCap->ReturnType = FD->getReturnType(); + + AutoType *AT = CurCap->ReturnType->getContainedAutoType(); + assert(AT && "lost auto type from lambda return type"); + if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) { + FD->setInvalidDecl(); + return StmtError(); + } + CurCap->ReturnType = FnRetType = FD->getReturnType(); + } else if (CurCap->HasImplicitReturnType) { + // For blocks/lambdas with implicit return types, we check each return + // statement individually, and deduce the common return type when the block + // or lambda is completed. + // FIXME: Fold this into the 'auto' codepath above. + if (RetValExp && !isa<InitListExpr>(RetValExp)) { + ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); + if (Result.isInvalid()) + return StmtError(); + RetValExp = Result.get(); + + // DR1048: even prior to C++14, we should use the 'auto' deduction rules + // when deducing a return type for a lambda-expression (or by extension + // for a block). These rules differ from the stated C++11 rules only in + // that they remove top-level cv-qualifiers. + if (!CurContext->isDependentContext()) + FnRetType = RetValExp->getType().getUnqualifiedType(); + else + FnRetType = CurCap->ReturnType = Context.DependentTy; + } else { + if (RetValExp) { + // C++11 [expr.lambda.prim]p4 bans inferring the result from an + // initializer list, because it is not an expression (even + // though we represent it as one). We still deduce 'void'. + Diag(ReturnLoc, diag::err_lambda_return_init_list) + << RetValExp->getSourceRange(); + } + + FnRetType = Context.VoidTy; + } + + // Although we'll properly infer the type of the block once it's completed, + // make sure we provide a return type now for better error recovery. + if (CurCap->ReturnType.isNull()) + CurCap->ReturnType = FnRetType; + } + assert(!FnRetType.isNull()); + + if (auto *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { + if (CurBlock->FunctionType->castAs<FunctionType>()->getNoReturnAttr()) { + Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); + return StmtError(); + } + } else if (auto *CurRegion = dyn_cast<CapturedRegionScopeInfo>(CurCap)) { + Diag(ReturnLoc, diag::err_return_in_captured_stmt) << CurRegion->getRegionName(); + return StmtError(); + } else { + assert(CurLambda && "unknown kind of captured scope"); + if (CurLambda->CallOperator->getType() + ->castAs<FunctionType>() + ->getNoReturnAttr()) { + Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); + 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. + const VarDecl *NRVOCandidate = nullptr; + if (FnRetType->isDependentType()) { + // Delay processing for now. TODO: there are lots of dependent + // types we can conclusively prove aren't void. + } else if (FnRetType->isVoidType()) { + if (RetValExp && !isa<InitListExpr>(RetValExp) && + !(getLangOpts().CPlusPlus && + (RetValExp->isTypeDependent() || + RetValExp->getType()->isVoidType()))) { + if (!getLangOpts().CPlusPlus && + RetValExp->getType()->isVoidType()) + Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; + else { + Diag(ReturnLoc, diag::err_return_block_has_expr); + RetValExp = nullptr; + } + } + } else if (!RetValExp) { + return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); + } else if (!RetValExp->isTypeDependent()) { + // we have a non-void block 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. + + // In C++ the return statement is handled via a copy initialization. + // the C version of which boils down to CheckSingleAssignmentConstraints. + NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict); + InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, + FnRetType, + NRVOCandidate != nullptr); + ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, + FnRetType, RetValExp); + if (Res.isInvalid()) { + // FIXME: Cleanup temporaries here, anyway? + return StmtError(); + } + RetValExp = Res.get(); + CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc); + } else { + NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict); + } + + if (RetValExp) { + ExprResult ER = + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.get(); + } + auto *Result = + ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate); + + // If we need to check for the named return value optimization, + // or if we need to infer the return type, + // save the return statement in our scope for later processing. + if (CurCap->HasImplicitReturnType || NRVOCandidate) + FunctionScopes.back()->Returns.push_back(Result); + + if (FunctionScopes.back()->FirstReturnLoc.isInvalid()) + FunctionScopes.back()->FirstReturnLoc = ReturnLoc; + + return Result; +} + +namespace { +/// Marks all typedefs in all local classes in a type referenced. +/// +/// In a function like +/// auto f() { +/// struct S { typedef int a; }; +/// return S(); +/// } +/// +/// the local type escapes and could be referenced in some TUs but not in +/// others. Pretend that all local typedefs are always referenced, to not warn +/// on this. This isn't necessary if f has internal linkage, or the typedef +/// is private. +class LocalTypedefNameReferencer + : public RecursiveASTVisitor<LocalTypedefNameReferencer> { +public: + LocalTypedefNameReferencer(Sema &S) : S(S) {} + bool VisitRecordType(const RecordType *RT); +private: + Sema &S; +}; +bool LocalTypedefNameReferencer::VisitRecordType(const RecordType *RT) { + auto *R = dyn_cast<CXXRecordDecl>(RT->getDecl()); + if (!R || !R->isLocalClass() || !R->isLocalClass()->isExternallyVisible() || + R->isDependentType()) + return true; + for (auto *TmpD : R->decls()) + if (auto *T = dyn_cast<TypedefNameDecl>(TmpD)) + if (T->getAccess() != AS_private || R->hasFriends()) + S.MarkAnyDeclReferenced(T->getLocation(), T, /*OdrUse=*/false); + return true; +} +} + +TypeLoc Sema::getReturnTypeLoc(FunctionDecl *FD) const { + return FD->getTypeSourceInfo() + ->getTypeLoc() + .getAsAdjusted<FunctionProtoTypeLoc>() + .getReturnLoc(); +} + +/// Deduce the return type for a function from a returned expression, per +/// C++1y [dcl.spec.auto]p6. +bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD, + SourceLocation ReturnLoc, + Expr *&RetExpr, + AutoType *AT) { + // If this is the conversion function for a lambda, we choose to deduce it + // type from the corresponding call operator, not from the synthesized return + // statement within it. See Sema::DeduceReturnType. + if (isLambdaConversionOperator(FD)) + return false; + + TypeLoc OrigResultType = getReturnTypeLoc(FD); + QualType Deduced; + + if (RetExpr && isa<InitListExpr>(RetExpr)) { + // If the deduction is for a return statement and the initializer is + // a braced-init-list, the program is ill-formed. + Diag(RetExpr->getExprLoc(), + getCurLambda() ? diag::err_lambda_return_init_list + : diag::err_auto_fn_return_init_list) + << RetExpr->getSourceRange(); + return true; + } + + if (FD->isDependentContext()) { + // C++1y [dcl.spec.auto]p12: + // Return type deduction [...] occurs when the definition is + // instantiated even if the function body contains a return + // statement with a non-type-dependent operand. + assert(AT->isDeduced() && "should have deduced to dependent type"); + return false; + } + + if (RetExpr) { + // Otherwise, [...] deduce a value for U using the rules of template + // argument deduction. + DeduceAutoResult DAR = DeduceAutoType(OrigResultType, RetExpr, Deduced); + + if (DAR == DAR_Failed && !FD->isInvalidDecl()) + Diag(RetExpr->getExprLoc(), diag::err_auto_fn_deduction_failure) + << OrigResultType.getType() << RetExpr->getType(); + + if (DAR != DAR_Succeeded) + return true; + + // If a local type is part of the returned type, mark its fields as + // referenced. + LocalTypedefNameReferencer Referencer(*this); + Referencer.TraverseType(RetExpr->getType()); + } else { + // In the case of a return with no operand, the initializer is considered + // to be void(). + // + // Deduction here can only succeed if the return type is exactly 'cv auto' + // or 'decltype(auto)', so just check for that case directly. + if (!OrigResultType.getType()->getAs<AutoType>()) { + Diag(ReturnLoc, diag::err_auto_fn_return_void_but_not_auto) + << OrigResultType.getType(); + return true; + } + // We always deduce U = void in this case. + Deduced = SubstAutoType(OrigResultType.getType(), Context.VoidTy); + if (Deduced.isNull()) + return true; + } + + // CUDA: Kernel function must have 'void' return type. + if (getLangOpts().CUDA) + if (FD->hasAttr<CUDAGlobalAttr>() && !Deduced->isVoidType()) { + Diag(FD->getLocation(), diag::err_kern_type_not_void_return) + << FD->getType() << FD->getSourceRange(); + return true; + } + + // If a function with a declared return type that contains a placeholder type + // has multiple return statements, the return type is deduced for each return + // statement. [...] if the type deduced is not the same in each deduction, + // the program is ill-formed. + QualType DeducedT = AT->getDeducedType(); + if (!DeducedT.isNull() && !FD->isInvalidDecl()) { + AutoType *NewAT = Deduced->getContainedAutoType(); + // It is possible that NewAT->getDeducedType() is null. When that happens, + // we should not crash, instead we ignore this deduction. + if (NewAT->getDeducedType().isNull()) + return false; + + CanQualType OldDeducedType = Context.getCanonicalFunctionResultType( + DeducedT); + CanQualType NewDeducedType = Context.getCanonicalFunctionResultType( + NewAT->getDeducedType()); + if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) { + const LambdaScopeInfo *LambdaSI = getCurLambda(); + if (LambdaSI && LambdaSI->HasImplicitReturnType) { + Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible) + << NewAT->getDeducedType() << DeducedT + << true /*IsLambda*/; + } else { + Diag(ReturnLoc, diag::err_auto_fn_different_deductions) + << (AT->isDecltypeAuto() ? 1 : 0) + << NewAT->getDeducedType() << DeducedT; + } + return true; + } + } else if (!FD->isInvalidDecl()) { + // Update all declarations of the function to have the deduced return type. + Context.adjustDeducedFunctionResultType(FD, Deduced); + } + + return false; +} + +StmtResult +Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp, + Scope *CurScope) { + // Correct typos, in case the containing function returns 'auto' and + // RetValExp should determine the deduced type. + ExprResult RetVal = CorrectDelayedTyposInExpr(RetValExp); + if (RetVal.isInvalid()) + return StmtError(); + StmtResult R = BuildReturnStmt(ReturnLoc, RetVal.get()); + if (R.isInvalid() || ExprEvalContexts.back().Context == + ExpressionEvaluationContext::DiscardedStatement) + return R; + + if (VarDecl *VD = + const_cast<VarDecl*>(cast<ReturnStmt>(R.get())->getNRVOCandidate())) { + CurScope->addNRVOCandidate(VD); + } else { + CurScope->setNoNRVO(); + } + + CheckJumpOutOfSEHFinally(*this, ReturnLoc, *CurScope->getFnParent()); + + return R; +} + +StmtResult Sema::BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { + // Check for unexpanded parameter packs. + if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) + return StmtError(); + + if (isa<CapturingScopeInfo>(getCurFunction())) + return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); + + QualType FnRetType; + QualType RelatedRetType; + const AttrVec *Attrs = nullptr; + bool isObjCMethod = false; + + if (const FunctionDecl *FD = getCurFunctionDecl()) { + FnRetType = FD->getReturnType(); + if (FD->hasAttrs()) + Attrs = &FD->getAttrs(); + if (FD->isNoReturn()) + Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) + << FD->getDeclName(); + if (FD->isMain() && RetValExp) + if (isa<CXXBoolLiteralExpr>(RetValExp)) + Diag(ReturnLoc, diag::warn_main_returns_bool_literal) + << RetValExp->getSourceRange(); + } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { + FnRetType = MD->getReturnType(); + isObjCMethod = true; + if (MD->hasAttrs()) + Attrs = &MD->getAttrs(); + if (MD->hasRelatedResultType() && MD->getClassInterface()) { + // In the implementation of a method with a related return type, the + // type used to type-check the validity of return statements within the + // method body is a pointer to the type of the class being implemented. + RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); + RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); + } + } else // If we don't have a function/method context, bail. + return StmtError(); + + // C++1z: discarded return statements are not considered when deducing a + // return type. + if (ExprEvalContexts.back().Context == + ExpressionEvaluationContext::DiscardedStatement && + FnRetType->getContainedAutoType()) { + if (RetValExp) { + ExprResult ER = + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.get(); + } + return ReturnStmt::Create(Context, ReturnLoc, RetValExp, + /* NRVOCandidate=*/nullptr); + } + + // FIXME: Add a flag to the ScopeInfo to indicate whether we're performing + // deduction. + if (getLangOpts().CPlusPlus14) { + if (AutoType *AT = FnRetType->getContainedAutoType()) { + FunctionDecl *FD = cast<FunctionDecl>(CurContext); + if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) { + FD->setInvalidDecl(); + return StmtError(); + } else { + FnRetType = FD->getReturnType(); + } + } + } + + bool HasDependentReturnType = FnRetType->isDependentType(); + + ReturnStmt *Result = nullptr; + if (FnRetType->isVoidType()) { + if (RetValExp) { + if (isa<InitListExpr>(RetValExp)) { + // We simply never allow init lists as the return value of void + // functions. This is compatible because this was never allowed before, + // so there's no legacy code to deal with. + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + int FunctionKind = 0; + if (isa<ObjCMethodDecl>(CurDecl)) + FunctionKind = 1; + else if (isa<CXXConstructorDecl>(CurDecl)) + FunctionKind = 2; + else if (isa<CXXDestructorDecl>(CurDecl)) + FunctionKind = 3; + + Diag(ReturnLoc, diag::err_return_init_list) + << CurDecl->getDeclName() << FunctionKind + << RetValExp->getSourceRange(); + + // Drop the expression. + RetValExp = nullptr; + } else if (!RetValExp->isTypeDependent()) { + // C99 6.8.6.4p1 (ext_ since GCC warns) + unsigned D = diag::ext_return_has_expr; + if (RetValExp->getType()->isVoidType()) { + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + if (isa<CXXConstructorDecl>(CurDecl) || + isa<CXXDestructorDecl>(CurDecl)) + D = diag::err_ctor_dtor_returns_void; + else + D = diag::ext_return_has_void_expr; + } + else { + ExprResult Result = RetValExp; + Result = IgnoredValueConversions(Result.get()); + if (Result.isInvalid()) + return StmtError(); + RetValExp = Result.get(); + RetValExp = ImpCastExprToType(RetValExp, + Context.VoidTy, CK_ToVoid).get(); + } + // return of void in constructor/destructor is illegal in C++. + if (D == diag::err_ctor_dtor_returns_void) { + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + Diag(ReturnLoc, D) + << CurDecl->getDeclName() << isa<CXXDestructorDecl>(CurDecl) + << RetValExp->getSourceRange(); + } + // return (some void expression); is legal in C++. + else if (D != diag::ext_return_has_void_expr || + !getLangOpts().CPlusPlus) { + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + + int FunctionKind = 0; + if (isa<ObjCMethodDecl>(CurDecl)) + FunctionKind = 1; + else if (isa<CXXConstructorDecl>(CurDecl)) + FunctionKind = 2; + else if (isa<CXXDestructorDecl>(CurDecl)) + FunctionKind = 3; + + Diag(ReturnLoc, D) + << CurDecl->getDeclName() << FunctionKind + << RetValExp->getSourceRange(); + } + } + + if (RetValExp) { + ExprResult ER = + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.get(); + } + } + + Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp, + /* NRVOCandidate=*/nullptr); + } else if (!RetValExp && !HasDependentReturnType) { + FunctionDecl *FD = getCurFunctionDecl(); + + unsigned DiagID; + if (getLangOpts().CPlusPlus11 && FD && FD->isConstexpr()) { + // C++11 [stmt.return]p2 + DiagID = diag::err_constexpr_return_missing_expr; + FD->setInvalidDecl(); + } else if (getLangOpts().C99) { + // C99 6.8.6.4p1 (ext_ since GCC warns) + DiagID = diag::ext_return_missing_expr; + } else { + // C90 6.6.6.4p4 + DiagID = diag::warn_return_missing_expr; + } + + if (FD) + Diag(ReturnLoc, DiagID) + << FD->getIdentifier() << 0 /*fn*/ << FD->isConsteval(); + else + Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; + + Result = ReturnStmt::Create(Context, ReturnLoc, /* RetExpr=*/nullptr, + /* NRVOCandidate=*/nullptr); + } else { + assert(RetValExp || HasDependentReturnType); + const VarDecl *NRVOCandidate = nullptr; + + QualType RetType = RelatedRetType.isNull() ? FnRetType : RelatedRetType; + + // 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. + if (RetValExp) + NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, CES_Strict); + if (!HasDependentReturnType && !RetValExp->isTypeDependent()) { + // we have a non-void function with an expression, continue checking + InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, + RetType, + NRVOCandidate != nullptr); + ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, + RetType, RetValExp); + if (Res.isInvalid()) { + // FIXME: Clean up temporaries here anyway? + return StmtError(); + } + RetValExp = Res.getAs<Expr>(); + + // If we have a related result type, we need to implicitly + // convert back to the formal result type. We can't pretend to + // initialize the result again --- we might end double-retaining + // --- so instead we initialize a notional temporary. + if (!RelatedRetType.isNull()) { + Entity = InitializedEntity::InitializeRelatedResult(getCurMethodDecl(), + FnRetType); + Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp); + if (Res.isInvalid()) { + // FIXME: Clean up temporaries here anyway? + return StmtError(); + } + RetValExp = Res.getAs<Expr>(); + } + + CheckReturnValExpr(RetValExp, FnRetType, ReturnLoc, isObjCMethod, Attrs, + getCurFunctionDecl()); + } + + if (RetValExp) { + ExprResult ER = + ActOnFinishFullExpr(RetValExp, ReturnLoc, /*DiscardedValue*/ false); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.get(); + } + Result = ReturnStmt::Create(Context, ReturnLoc, RetValExp, NRVOCandidate); + } + + // If we need to check for the named return value optimization, save the + // return statement in our scope for later processing. + if (Result->getNRVOCandidate()) + FunctionScopes.back()->Returns.push_back(Result); + + if (FunctionScopes.back()->FirstReturnLoc.isInvalid()) + FunctionScopes.back()->FirstReturnLoc = ReturnLoc; + + return Result; +} + +StmtResult +Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, + SourceLocation RParen, Decl *Parm, + Stmt *Body) { + VarDecl *Var = cast_or_null<VarDecl>(Parm); + if (Var && Var->isInvalidDecl()) + return StmtError(); + + return new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body); +} + +StmtResult +Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { + return new (Context) ObjCAtFinallyStmt(AtLoc, Body); +} + +StmtResult +Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, + MultiStmtArg CatchStmts, Stmt *Finally) { + if (!getLangOpts().ObjCExceptions) + Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; + + setFunctionHasBranchProtectedScope(); + unsigned NumCatchStmts = CatchStmts.size(); + return ObjCAtTryStmt::Create(Context, AtLoc, Try, CatchStmts.data(), + NumCatchStmts, Finally); +} + +StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) { + if (Throw) { + ExprResult Result = DefaultLvalueConversion(Throw); + if (Result.isInvalid()) + return StmtError(); + + Result = ActOnFinishFullExpr(Result.get(), /*DiscardedValue*/ false); + if (Result.isInvalid()) + return StmtError(); + Throw = Result.get(); + + QualType ThrowType = Throw->getType(); + // Make sure the expression type is an ObjC pointer or "void *". + if (!ThrowType->isDependentType() && + !ThrowType->isObjCObjectPointerType()) { + const PointerType *PT = ThrowType->getAs<PointerType>(); + if (!PT || !PT->getPointeeType()->isVoidType()) + return StmtError(Diag(AtLoc, diag::err_objc_throw_expects_object) + << Throw->getType() << Throw->getSourceRange()); + } + } + + return new (Context) ObjCAtThrowStmt(AtLoc, Throw); +} + +StmtResult +Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, + Scope *CurScope) { + if (!getLangOpts().ObjCExceptions) + Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; + + if (!Throw) { + // @throw without an expression designates a rethrow (which must 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::err_rethrow_used_outside_catch)); + } + return BuildObjCAtThrowStmt(AtLoc, Throw); +} + +ExprResult +Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { + ExprResult result = DefaultLvalueConversion(operand); + if (result.isInvalid()) + return ExprError(); + operand = result.get(); + + // Make sure the expression type is an ObjC pointer or "void *". + QualType type = operand->getType(); + if (!type->isDependentType() && + !type->isObjCObjectPointerType()) { + const PointerType *pointerType = type->getAs<PointerType>(); + if (!pointerType || !pointerType->getPointeeType()->isVoidType()) { + if (getLangOpts().CPlusPlus) { + if (RequireCompleteType(atLoc, type, + diag::err_incomplete_receiver_type)) + return Diag(atLoc, diag::err_objc_synchronized_expects_object) + << type << operand->getSourceRange(); + + ExprResult result = PerformContextuallyConvertToObjCPointer(operand); + if (result.isInvalid()) + return ExprError(); + if (!result.isUsable()) + return Diag(atLoc, diag::err_objc_synchronized_expects_object) + << type << operand->getSourceRange(); + + operand = result.get(); + } else { + return Diag(atLoc, diag::err_objc_synchronized_expects_object) + << type << operand->getSourceRange(); + } + } + } + + // The operand to @synchronized is a full-expression. + return ActOnFinishFullExpr(operand, /*DiscardedValue*/ false); +} + +StmtResult +Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, + Stmt *SyncBody) { + // We can't jump into or indirect-jump out of a @synchronized block. + setFunctionHasBranchProtectedScope(); + return new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody); +} + +/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block +/// and creates a proper catch handler from them. +StmtResult +Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, + Stmt *HandlerBlock) { + // There's nothing to test that ActOnExceptionDecl didn't already test. + return new (Context) + CXXCatchStmt(CatchLoc, cast_or_null<VarDecl>(ExDecl), HandlerBlock); +} + +StmtResult +Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { + setFunctionHasBranchProtectedScope(); + return new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body); +} + +namespace { +class CatchHandlerType { + QualType QT; + unsigned IsPointer : 1; + + // This is a special constructor to be used only with DenseMapInfo's + // getEmptyKey() and getTombstoneKey() functions. + friend struct llvm::DenseMapInfo<CatchHandlerType>; + enum Unique { ForDenseMap }; + CatchHandlerType(QualType QT, Unique) : QT(QT), IsPointer(false) {} + +public: + /// Used when creating a CatchHandlerType from a handler type; will determine + /// whether the type is a pointer or reference and will strip off the top + /// level pointer and cv-qualifiers. + CatchHandlerType(QualType Q) : QT(Q), IsPointer(false) { + if (QT->isPointerType()) + IsPointer = true; + + if (IsPointer || QT->isReferenceType()) + QT = QT->getPointeeType(); + QT = QT.getUnqualifiedType(); + } + + /// Used when creating a CatchHandlerType from a base class type; pretends the + /// type passed in had the pointer qualifier, does not need to get an + /// unqualified type. + CatchHandlerType(QualType QT, bool IsPointer) + : QT(QT), IsPointer(IsPointer) {} + + QualType underlying() const { return QT; } + bool isPointer() const { return IsPointer; } + + friend bool operator==(const CatchHandlerType &LHS, + const CatchHandlerType &RHS) { + // If the pointer qualification does not match, we can return early. + if (LHS.IsPointer != RHS.IsPointer) + return false; + // Otherwise, check the underlying type without cv-qualifiers. + return LHS.QT == RHS.QT; + } +}; +} // namespace + +namespace llvm { +template <> struct DenseMapInfo<CatchHandlerType> { + static CatchHandlerType getEmptyKey() { + return CatchHandlerType(DenseMapInfo<QualType>::getEmptyKey(), + CatchHandlerType::ForDenseMap); + } + + static CatchHandlerType getTombstoneKey() { + return CatchHandlerType(DenseMapInfo<QualType>::getTombstoneKey(), + CatchHandlerType::ForDenseMap); + } + + static unsigned getHashValue(const CatchHandlerType &Base) { + return DenseMapInfo<QualType>::getHashValue(Base.underlying()); + } + + static bool isEqual(const CatchHandlerType &LHS, + const CatchHandlerType &RHS) { + return LHS == RHS; + } +}; +} + +namespace { +class CatchTypePublicBases { + ASTContext &Ctx; + const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &TypesToCheck; + const bool CheckAgainstPointer; + + CXXCatchStmt *FoundHandler; + CanQualType FoundHandlerType; + +public: + CatchTypePublicBases( + ASTContext &Ctx, + const llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> &T, bool C) + : Ctx(Ctx), TypesToCheck(T), CheckAgainstPointer(C), + FoundHandler(nullptr) {} + + CXXCatchStmt *getFoundHandler() const { return FoundHandler; } + CanQualType getFoundHandlerType() const { return FoundHandlerType; } + + bool operator()(const CXXBaseSpecifier *S, CXXBasePath &) { + if (S->getAccessSpecifier() == AccessSpecifier::AS_public) { + CatchHandlerType Check(S->getType(), CheckAgainstPointer); + const auto &M = TypesToCheck; + auto I = M.find(Check); + if (I != M.end()) { + FoundHandler = I->second; + FoundHandlerType = Ctx.getCanonicalType(S->getType()); + return true; + } + } + return false; + } +}; +} + +/// ActOnCXXTryBlock - Takes a try compound-statement and a number of +/// handlers and creates a try statement from them. +StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, + ArrayRef<Stmt *> Handlers) { + // Don't report an error if 'try' is used in system headers. + if (!getLangOpts().CXXExceptions && + !getSourceManager().isInSystemHeader(TryLoc) && !getLangOpts().CUDA) { + // Delay error emission for the OpenMP device code. + targetDiag(TryLoc, diag::err_exceptions_disabled) << "try"; + } + + // Exceptions aren't allowed in CUDA device code. + if (getLangOpts().CUDA) + CUDADiagIfDeviceCode(TryLoc, diag::err_cuda_device_exceptions) + << "try" << CurrentCUDATarget(); + + if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope()) + Diag(TryLoc, diag::err_omp_simd_region_cannot_use_stmt) << "try"; + + sema::FunctionScopeInfo *FSI = getCurFunction(); + + // C++ try is incompatible with SEH __try. + if (!getLangOpts().Borland && FSI->FirstSEHTryLoc.isValid()) { + Diag(TryLoc, diag::err_mixing_cxx_try_seh_try); + Diag(FSI->FirstSEHTryLoc, diag::note_conflicting_try_here) << "'__try'"; + } + + const unsigned NumHandlers = Handlers.size(); + assert(!Handlers.empty() && + "The parser shouldn't call this if there are no handlers."); + + llvm::DenseMap<CatchHandlerType, CXXCatchStmt *> HandledTypes; + for (unsigned i = 0; i < NumHandlers; ++i) { + CXXCatchStmt *H = cast<CXXCatchStmt>(Handlers[i]); + + // Diagnose when the handler is a catch-all handler, but it isn't the last + // handler for the try block. [except.handle]p5. Also, skip exception + // declarations that are invalid, since we can't usefully report on them. + if (!H->getExceptionDecl()) { + if (i < NumHandlers - 1) + return StmtError(Diag(H->getBeginLoc(), diag::err_early_catch_all)); + continue; + } else if (H->getExceptionDecl()->isInvalidDecl()) + continue; + + // Walk the type hierarchy to diagnose when this type has already been + // handled (duplication), or cannot be handled (derivation inversion). We + // ignore top-level cv-qualifiers, per [except.handle]p3 + CatchHandlerType HandlerCHT = + (QualType)Context.getCanonicalType(H->getCaughtType()); + + // We can ignore whether the type is a reference or a pointer; we need the + // underlying declaration type in order to get at the underlying record + // decl, if there is one. + QualType Underlying = HandlerCHT.underlying(); + if (auto *RD = Underlying->getAsCXXRecordDecl()) { + if (!RD->hasDefinition()) + continue; + // Check that none of the public, unambiguous base classes are in the + // map ([except.handle]p1). Give the base classes the same pointer + // qualification as the original type we are basing off of. This allows + // comparison against the handler type using the same top-level pointer + // as the original type. + CXXBasePaths Paths; + Paths.setOrigin(RD); + CatchTypePublicBases CTPB(Context, HandledTypes, HandlerCHT.isPointer()); + if (RD->lookupInBases(CTPB, Paths)) { + const CXXCatchStmt *Problem = CTPB.getFoundHandler(); + if (!Paths.isAmbiguous(CTPB.getFoundHandlerType())) { + Diag(H->getExceptionDecl()->getTypeSpecStartLoc(), + diag::warn_exception_caught_by_earlier_handler) + << H->getCaughtType(); + Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(), + diag::note_previous_exception_handler) + << Problem->getCaughtType(); + } + } + } + + // Add the type the list of ones we have handled; diagnose if we've already + // handled it. + auto R = HandledTypes.insert(std::make_pair(H->getCaughtType(), H)); + if (!R.second) { + const CXXCatchStmt *Problem = R.first->second; + Diag(H->getExceptionDecl()->getTypeSpecStartLoc(), + diag::warn_exception_caught_by_earlier_handler) + << H->getCaughtType(); + Diag(Problem->getExceptionDecl()->getTypeSpecStartLoc(), + diag::note_previous_exception_handler) + << Problem->getCaughtType(); + } + } + + FSI->setHasCXXTry(TryLoc); + + return CXXTryStmt::Create(Context, TryLoc, TryBlock, Handlers); +} + +StmtResult Sema::ActOnSEHTryBlock(bool IsCXXTry, SourceLocation TryLoc, + Stmt *TryBlock, Stmt *Handler) { + assert(TryBlock && Handler); + + sema::FunctionScopeInfo *FSI = getCurFunction(); + + // SEH __try is incompatible with C++ try. Borland appears to support this, + // however. + if (!getLangOpts().Borland) { + if (FSI->FirstCXXTryLoc.isValid()) { + Diag(TryLoc, diag::err_mixing_cxx_try_seh_try); + Diag(FSI->FirstCXXTryLoc, diag::note_conflicting_try_here) << "'try'"; + } + } + + FSI->setHasSEHTry(TryLoc); + + // Reject __try in Obj-C methods, blocks, and captured decls, since we don't + // track if they use SEH. + DeclContext *DC = CurContext; + while (DC && !DC->isFunctionOrMethod()) + DC = DC->getParent(); + FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(DC); + if (FD) + FD->setUsesSEHTry(true); + else + Diag(TryLoc, diag::err_seh_try_outside_functions); + + // Reject __try on unsupported targets. + if (!Context.getTargetInfo().isSEHTrySupported()) + Diag(TryLoc, diag::err_seh_try_unsupported); + + return SEHTryStmt::Create(Context, IsCXXTry, TryLoc, TryBlock, Handler); +} + +StmtResult +Sema::ActOnSEHExceptBlock(SourceLocation Loc, + Expr *FilterExpr, + Stmt *Block) { + assert(FilterExpr && Block); + + if(!FilterExpr->getType()->isIntegerType()) { + return StmtError(Diag(FilterExpr->getExprLoc(), + diag::err_filter_expression_integral) + << FilterExpr->getType()); + } + + return SEHExceptStmt::Create(Context,Loc,FilterExpr,Block); +} + +void Sema::ActOnStartSEHFinallyBlock() { + CurrentSEHFinally.push_back(CurScope); +} + +void Sema::ActOnAbortSEHFinallyBlock() { + CurrentSEHFinally.pop_back(); +} + +StmtResult Sema::ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block) { + assert(Block); + CurrentSEHFinally.pop_back(); + return SEHFinallyStmt::Create(Context, Loc, Block); +} + +StmtResult +Sema::ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope) { + Scope *SEHTryParent = CurScope; + while (SEHTryParent && !SEHTryParent->isSEHTryScope()) + SEHTryParent = SEHTryParent->getParent(); + if (!SEHTryParent) + return StmtError(Diag(Loc, diag::err_ms___leave_not_in___try)); + CheckJumpOutOfSEHFinally(*this, Loc, *SEHTryParent); + + return new (Context) SEHLeaveStmt(Loc); +} + +StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, + bool IsIfExists, + NestedNameSpecifierLoc QualifierLoc, + DeclarationNameInfo NameInfo, + Stmt *Nested) +{ + return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, + QualifierLoc, NameInfo, + cast<CompoundStmt>(Nested)); +} + + +StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, + bool IsIfExists, + CXXScopeSpec &SS, + UnqualifiedId &Name, + Stmt *Nested) { + return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, + SS.getWithLocInContext(Context), + GetNameFromUnqualifiedId(Name), + Nested); +} + +RecordDecl* +Sema::CreateCapturedStmtRecordDecl(CapturedDecl *&CD, SourceLocation Loc, + unsigned NumParams) { + DeclContext *DC = CurContext; + while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext())) + DC = DC->getParent(); + + RecordDecl *RD = nullptr; + if (getLangOpts().CPlusPlus) + RD = CXXRecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, + /*Id=*/nullptr); + else + RD = RecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /*Id=*/nullptr); + + RD->setCapturedRecord(); + DC->addDecl(RD); + RD->setImplicit(); + RD->startDefinition(); + + assert(NumParams > 0 && "CapturedStmt requires context parameter"); + CD = CapturedDecl::Create(Context, CurContext, NumParams); + DC->addDecl(CD); + return RD; +} + +static bool +buildCapturedStmtCaptureList(Sema &S, CapturedRegionScopeInfo *RSI, + SmallVectorImpl<CapturedStmt::Capture> &Captures, + SmallVectorImpl<Expr *> &CaptureInits) { + for (const sema::Capture &Cap : RSI->Captures) { + if (Cap.isInvalid()) + continue; + + // Form the initializer for the capture. + ExprResult Init = S.BuildCaptureInit(Cap, Cap.getLocation(), + RSI->CapRegionKind == CR_OpenMP); + + // FIXME: Bail out now if the capture is not used and the initializer has + // no side-effects. + + // Create a field for this capture. + FieldDecl *Field = S.BuildCaptureField(RSI->TheRecordDecl, Cap); + + // Add the capture to our list of captures. + if (Cap.isThisCapture()) { + Captures.push_back(CapturedStmt::Capture(Cap.getLocation(), + CapturedStmt::VCK_This)); + } else if (Cap.isVLATypeCapture()) { + Captures.push_back( + CapturedStmt::Capture(Cap.getLocation(), CapturedStmt::VCK_VLAType)); + } else { + assert(Cap.isVariableCapture() && "unknown kind of capture"); + + if (S.getLangOpts().OpenMP && RSI->CapRegionKind == CR_OpenMP) + S.setOpenMPCaptureKind(Field, Cap.getVariable(), RSI->OpenMPLevel); + + Captures.push_back(CapturedStmt::Capture(Cap.getLocation(), + Cap.isReferenceCapture() + ? CapturedStmt::VCK_ByRef + : CapturedStmt::VCK_ByCopy, + Cap.getVariable())); + } + CaptureInits.push_back(Init.get()); + } + return false; +} + +void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope, + CapturedRegionKind Kind, + unsigned NumParams) { + CapturedDecl *CD = nullptr; + RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, NumParams); + + // Build the context parameter + DeclContext *DC = CapturedDecl::castToDeclContext(CD); + IdentifierInfo *ParamName = &Context.Idents.get("__context"); + QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD)); + auto *Param = + ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType, + ImplicitParamDecl::CapturedContext); + DC->addDecl(Param); + + CD->setContextParam(0, Param); + + // Enter the capturing scope for this captured region. + PushCapturedRegionScope(CurScope, CD, RD, Kind); + + if (CurScope) + PushDeclContext(CurScope, CD); + else + CurContext = CD; + + PushExpressionEvaluationContext( + ExpressionEvaluationContext::PotentiallyEvaluated); +} + +void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope, + CapturedRegionKind Kind, + ArrayRef<CapturedParamNameType> Params, + unsigned OpenMPCaptureLevel) { + CapturedDecl *CD = nullptr; + RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, Params.size()); + + // Build the context parameter + DeclContext *DC = CapturedDecl::castToDeclContext(CD); + bool ContextIsFound = false; + unsigned ParamNum = 0; + for (ArrayRef<CapturedParamNameType>::iterator I = Params.begin(), + E = Params.end(); + I != E; ++I, ++ParamNum) { + if (I->second.isNull()) { + assert(!ContextIsFound && + "null type has been found already for '__context' parameter"); + IdentifierInfo *ParamName = &Context.Idents.get("__context"); + QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD)) + .withConst() + .withRestrict(); + auto *Param = + ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType, + ImplicitParamDecl::CapturedContext); + DC->addDecl(Param); + CD->setContextParam(ParamNum, Param); + ContextIsFound = true; + } else { + IdentifierInfo *ParamName = &Context.Idents.get(I->first); + auto *Param = + ImplicitParamDecl::Create(Context, DC, Loc, ParamName, I->second, + ImplicitParamDecl::CapturedContext); + DC->addDecl(Param); + CD->setParam(ParamNum, Param); + } + } + assert(ContextIsFound && "no null type for '__context' parameter"); + if (!ContextIsFound) { + // Add __context implicitly if it is not specified. + IdentifierInfo *ParamName = &Context.Idents.get("__context"); + QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD)); + auto *Param = + ImplicitParamDecl::Create(Context, DC, Loc, ParamName, ParamType, + ImplicitParamDecl::CapturedContext); + DC->addDecl(Param); + CD->setContextParam(ParamNum, Param); + } + // Enter the capturing scope for this captured region. + PushCapturedRegionScope(CurScope, CD, RD, Kind, OpenMPCaptureLevel); + + if (CurScope) + PushDeclContext(CurScope, CD); + else + CurContext = CD; + + PushExpressionEvaluationContext( + ExpressionEvaluationContext::PotentiallyEvaluated); +} + +void Sema::ActOnCapturedRegionError() { + DiscardCleanupsInEvaluationContext(); + PopExpressionEvaluationContext(); + PopDeclContext(); + PoppedFunctionScopePtr ScopeRAII = PopFunctionScopeInfo(); + CapturedRegionScopeInfo *RSI = cast<CapturedRegionScopeInfo>(ScopeRAII.get()); + + RecordDecl *Record = RSI->TheRecordDecl; + Record->setInvalidDecl(); + + SmallVector<Decl*, 4> Fields(Record->fields()); + ActOnFields(/*Scope=*/nullptr, Record->getLocation(), Record, Fields, + SourceLocation(), SourceLocation(), ParsedAttributesView()); +} + +StmtResult Sema::ActOnCapturedRegionEnd(Stmt *S) { + // Leave the captured scope before we start creating captures in the + // enclosing scope. + DiscardCleanupsInEvaluationContext(); + PopExpressionEvaluationContext(); + PopDeclContext(); + PoppedFunctionScopePtr ScopeRAII = PopFunctionScopeInfo(); + CapturedRegionScopeInfo *RSI = cast<CapturedRegionScopeInfo>(ScopeRAII.get()); + + SmallVector<CapturedStmt::Capture, 4> Captures; + SmallVector<Expr *, 4> CaptureInits; + if (buildCapturedStmtCaptureList(*this, RSI, Captures, CaptureInits)) + return StmtError(); + + CapturedDecl *CD = RSI->TheCapturedDecl; + RecordDecl *RD = RSI->TheRecordDecl; + + CapturedStmt *Res = CapturedStmt::Create( + getASTContext(), S, static_cast<CapturedRegionKind>(RSI->CapRegionKind), + Captures, CaptureInits, CD, RD); + + CD->setBody(Res->getCapturedStmt()); + RD->completeDefinition(); + + return Res; +} |