| //===--- 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()); |
|