| //===--- SemaExceptionSpec.cpp - C++ Exception Specifications ---*- C++ -*-===// |
| // |
| // 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 provides Sema routines for C++ exception specification testing. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Sema/SemaInternal.h" |
| #include "clang/AST/ASTMutationListener.h" |
| #include "clang/AST/CXXInheritance.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/ExprCXX.h" |
| #include "clang/AST/StmtObjC.h" |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/ADT/SmallString.h" |
| |
| namespace clang { |
| |
| static const FunctionProtoType *GetUnderlyingFunction(QualType T) |
| { |
| if (const PointerType *PtrTy = T->getAs<PointerType>()) |
| T = PtrTy->getPointeeType(); |
| else if (const ReferenceType *RefTy = T->getAs<ReferenceType>()) |
| T = RefTy->getPointeeType(); |
| else if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>()) |
| T = MPTy->getPointeeType(); |
| return T->getAs<FunctionProtoType>(); |
| } |
| |
| /// HACK: 2014-11-14 libstdc++ had a bug where it shadows std::swap with a |
| /// member swap function then tries to call std::swap unqualified from the |
| /// exception specification of that function. This function detects whether |
| /// we're in such a case and turns off delay-parsing of exception |
| /// specifications. Libstdc++ 6.1 (released 2016-04-27) appears to have |
| /// resolved it as side-effect of commit ddb63209a8d (2015-06-05). |
| bool Sema::isLibstdcxxEagerExceptionSpecHack(const Declarator &D) { |
| auto *RD = dyn_cast<CXXRecordDecl>(CurContext); |
| |
| // All the problem cases are member functions named "swap" within class |
| // templates declared directly within namespace std or std::__debug or |
| // std::__profile. |
| if (!RD || !RD->getIdentifier() || !RD->getDescribedClassTemplate() || |
| !D.getIdentifier() || !D.getIdentifier()->isStr("swap")) |
| return false; |
| |
| auto *ND = dyn_cast<NamespaceDecl>(RD->getDeclContext()); |
| if (!ND) |
| return false; |
| |
| bool IsInStd = ND->isStdNamespace(); |
| if (!IsInStd) { |
| // This isn't a direct member of namespace std, but it might still be |
| // libstdc++'s std::__debug::array or std::__profile::array. |
| IdentifierInfo *II = ND->getIdentifier(); |
| if (!II || !(II->isStr("__debug") || II->isStr("__profile")) || |
| !ND->isInStdNamespace()) |
| return false; |
| } |
| |
| // Only apply this hack within a system header. |
| if (!Context.getSourceManager().isInSystemHeader(D.getBeginLoc())) |
| return false; |
| |
| return llvm::StringSwitch<bool>(RD->getIdentifier()->getName()) |
| .Case("array", true) |
| .Case("pair", IsInStd) |
| .Case("priority_queue", IsInStd) |
| .Case("stack", IsInStd) |
| .Case("queue", IsInStd) |
| .Default(false); |
| } |
| |
| ExprResult Sema::ActOnNoexceptSpec(Expr *NoexceptExpr, |
| ExceptionSpecificationType &EST) { |
| |
| if (NoexceptExpr->isTypeDependent() || |
| NoexceptExpr->containsUnexpandedParameterPack()) { |
| EST = EST_DependentNoexcept; |
| return NoexceptExpr; |
| } |
| |
| llvm::APSInt Result; |
| ExprResult Converted = CheckConvertedConstantExpression( |
| NoexceptExpr, Context.BoolTy, Result, CCEK_Noexcept); |
| |
| if (Converted.isInvalid()) { |
| EST = EST_NoexceptFalse; |
| // Fill in an expression of 'false' as a fixup. |
| auto *BoolExpr = new (Context) |
| CXXBoolLiteralExpr(false, Context.BoolTy, NoexceptExpr->getBeginLoc()); |
| llvm::APSInt Value{1}; |
| Value = 0; |
| return ConstantExpr::Create(Context, BoolExpr, APValue{Value}); |
| } |
| |
| if (Converted.get()->isValueDependent()) { |
| EST = EST_DependentNoexcept; |
| return Converted; |
| } |
| |
| if (!Converted.isInvalid()) |
| EST = !Result ? EST_NoexceptFalse : EST_NoexceptTrue; |
| return Converted; |
| } |
| |
| /// CheckSpecifiedExceptionType - Check if the given type is valid in an |
| /// exception specification. Incomplete types, or pointers to incomplete types |
| /// other than void are not allowed. |
| /// |
| /// \param[in,out] T The exception type. This will be decayed to a pointer type |
| /// when the input is an array or a function type. |
| bool Sema::CheckSpecifiedExceptionType(QualType &T, SourceRange Range) { |
| // C++11 [except.spec]p2: |
| // A type cv T, "array of T", or "function returning T" denoted |
| // in an exception-specification is adjusted to type T, "pointer to T", or |
| // "pointer to function returning T", respectively. |
| // |
| // We also apply this rule in C++98. |
| if (T->isArrayType()) |
| T = Context.getArrayDecayedType(T); |
| else if (T->isFunctionType()) |
| T = Context.getPointerType(T); |
| |
| int Kind = 0; |
| QualType PointeeT = T; |
| if (const PointerType *PT = T->getAs<PointerType>()) { |
| PointeeT = PT->getPointeeType(); |
| Kind = 1; |
| |
| // cv void* is explicitly permitted, despite being a pointer to an |
| // incomplete type. |
| if (PointeeT->isVoidType()) |
| return false; |
| } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) { |
| PointeeT = RT->getPointeeType(); |
| Kind = 2; |
| |
| if (RT->isRValueReferenceType()) { |
| // C++11 [except.spec]p2: |
| // A type denoted in an exception-specification shall not denote [...] |
| // an rvalue reference type. |
| Diag(Range.getBegin(), diag::err_rref_in_exception_spec) |
| << T << Range; |
| return true; |
| } |
| } |
| |
| // C++11 [except.spec]p2: |
| // A type denoted in an exception-specification shall not denote an |
| // incomplete type other than a class currently being defined [...]. |
| // A type denoted in an exception-specification shall not denote a |
| // pointer or reference to an incomplete type, other than (cv) void* or a |
| // pointer or reference to a class currently being defined. |
| // In Microsoft mode, downgrade this to a warning. |
| unsigned DiagID = diag::err_incomplete_in_exception_spec; |
| bool ReturnValueOnError = true; |
| if (getLangOpts().MSVCCompat) { |
| DiagID = diag::ext_incomplete_in_exception_spec; |
| ReturnValueOnError = false; |
| } |
| if (!(PointeeT->isRecordType() && |
| PointeeT->castAs<RecordType>()->isBeingDefined()) && |
| RequireCompleteType(Range.getBegin(), PointeeT, DiagID, Kind, Range)) |
| return ReturnValueOnError; |
| |
| // The MSVC compatibility mode doesn't extend to sizeless types, |
| // so diagnose them separately. |
| if (PointeeT->isSizelessType() && Kind != 1) { |
| Diag(Range.getBegin(), diag::err_sizeless_in_exception_spec) |
| << (Kind == 2 ? 1 : 0) << PointeeT << Range; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /// CheckDistantExceptionSpec - Check if the given type is a pointer or pointer |
| /// to member to a function with an exception specification. This means that |
| /// it is invalid to add another level of indirection. |
| bool Sema::CheckDistantExceptionSpec(QualType T) { |
| // C++17 removes this rule in favor of putting exception specifications into |
| // the type system. |
| if (getLangOpts().CPlusPlus17) |
| return false; |
| |
| if (const PointerType *PT = T->getAs<PointerType>()) |
| T = PT->getPointeeType(); |
| else if (const MemberPointerType *PT = T->getAs<MemberPointerType>()) |
| T = PT->getPointeeType(); |
| else |
| return false; |
| |
| const FunctionProtoType *FnT = T->getAs<FunctionProtoType>(); |
| if (!FnT) |
| return false; |
| |
| return FnT->hasExceptionSpec(); |
| } |
| |
| const FunctionProtoType * |
| Sema::ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT) { |
| if (FPT->getExceptionSpecType() == EST_Unparsed) { |
| Diag(Loc, diag::err_exception_spec_not_parsed); |
| return nullptr; |
| } |
| |
| if (!isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) |
| return FPT; |
| |
| FunctionDecl *SourceDecl = FPT->getExceptionSpecDecl(); |
| const FunctionProtoType *SourceFPT = |
| SourceDecl->getType()->castAs<FunctionProtoType>(); |
| |
| // If the exception specification has already been resolved, just return it. |
| if (!isUnresolvedExceptionSpec(SourceFPT->getExceptionSpecType())) |
| return SourceFPT; |
| |
| // Compute or instantiate the exception specification now. |
| if (SourceFPT->getExceptionSpecType() == EST_Unevaluated) |
| EvaluateImplicitExceptionSpec(Loc, SourceDecl); |
| else |
| InstantiateExceptionSpec(Loc, SourceDecl); |
| |
| const FunctionProtoType *Proto = |
| SourceDecl->getType()->castAs<FunctionProtoType>(); |
| if (Proto->getExceptionSpecType() == clang::EST_Unparsed) { |
| Diag(Loc, diag::err_exception_spec_not_parsed); |
| Proto = nullptr; |
| } |
| return Proto; |
| } |
| |
| void |
| Sema::UpdateExceptionSpec(FunctionDecl *FD, |
| const FunctionProtoType::ExceptionSpecInfo &ESI) { |
| // If we've fully resolved the exception specification, notify listeners. |
| if (!isUnresolvedExceptionSpec(ESI.Type)) |
| if (auto *Listener = getASTMutationListener()) |
| Listener->ResolvedExceptionSpec(FD); |
| |
| for (FunctionDecl *Redecl : FD->redecls()) |
| Context.adjustExceptionSpec(Redecl, ESI); |
| } |
| |
| static bool exceptionSpecNotKnownYet(const FunctionDecl *FD) { |
| auto *MD = dyn_cast<CXXMethodDecl>(FD); |
| if (!MD) |
| return false; |
| |
| auto EST = MD->getType()->castAs<FunctionProtoType>()->getExceptionSpecType(); |
| return EST == EST_Unparsed || |
| (EST == EST_Unevaluated && MD->getParent()->isBeingDefined()); |
| } |
| |
| static bool CheckEquivalentExceptionSpecImpl( |
| Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID, |
| const FunctionProtoType *Old, SourceLocation OldLoc, |
| const FunctionProtoType *New, SourceLocation NewLoc, |
| bool *MissingExceptionSpecification = nullptr, |
| bool *MissingEmptyExceptionSpecification = nullptr, |
| bool AllowNoexceptAllMatchWithNoSpec = false, bool IsOperatorNew = false); |
| |
| /// Determine whether a function has an implicitly-generated exception |
| /// specification. |
| static bool hasImplicitExceptionSpec(FunctionDecl *Decl) { |
| if (!isa<CXXDestructorDecl>(Decl) && |
| Decl->getDeclName().getCXXOverloadedOperator() != OO_Delete && |
| Decl->getDeclName().getCXXOverloadedOperator() != OO_Array_Delete) |
| return false; |
| |
| // For a function that the user didn't declare: |
| // - if this is a destructor, its exception specification is implicit. |
| // - if this is 'operator delete' or 'operator delete[]', the exception |
| // specification is as-if an explicit exception specification was given |
| // (per [basic.stc.dynamic]p2). |
| if (!Decl->getTypeSourceInfo()) |
| return isa<CXXDestructorDecl>(Decl); |
| |
| auto *Ty = Decl->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>(); |
| return !Ty->hasExceptionSpec(); |
| } |
| |
| bool Sema::CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New) { |
| // Just completely ignore this under -fno-exceptions prior to C++17. |
| // In C++17 onwards, the exception specification is part of the type and |
| // we will diagnose mismatches anyway, so it's better to check for them here. |
| if (!getLangOpts().CXXExceptions && !getLangOpts().CPlusPlus17) |
| return false; |
| |
| OverloadedOperatorKind OO = New->getDeclName().getCXXOverloadedOperator(); |
| bool IsOperatorNew = OO == OO_New || OO == OO_Array_New; |
| bool MissingExceptionSpecification = false; |
| bool MissingEmptyExceptionSpecification = false; |
| |
| unsigned DiagID = diag::err_mismatched_exception_spec; |
| bool ReturnValueOnError = true; |
| if (getLangOpts().MSVCCompat) { |
| DiagID = diag::ext_mismatched_exception_spec; |
| ReturnValueOnError = false; |
| } |
| |
| // If we're befriending a member function of a class that's currently being |
| // defined, we might not be able to work out its exception specification yet. |
| // If not, defer the check until later. |
| if (exceptionSpecNotKnownYet(Old) || exceptionSpecNotKnownYet(New)) { |
| DelayedEquivalentExceptionSpecChecks.push_back({New, Old}); |
| return false; |
| } |
| |
| // Check the types as written: they must match before any exception |
| // specification adjustment is applied. |
| if (!CheckEquivalentExceptionSpecImpl( |
| *this, PDiag(DiagID), PDiag(diag::note_previous_declaration), |
| Old->getType()->getAs<FunctionProtoType>(), Old->getLocation(), |
| New->getType()->getAs<FunctionProtoType>(), New->getLocation(), |
| &MissingExceptionSpecification, &MissingEmptyExceptionSpecification, |
| /*AllowNoexceptAllMatchWithNoSpec=*/true, IsOperatorNew)) { |
| // C++11 [except.spec]p4 [DR1492]: |
| // If a declaration of a function has an implicit |
| // exception-specification, other declarations of the function shall |
| // not specify an exception-specification. |
| if (getLangOpts().CPlusPlus11 && getLangOpts().CXXExceptions && |
| hasImplicitExceptionSpec(Old) != hasImplicitExceptionSpec(New)) { |
| Diag(New->getLocation(), diag::ext_implicit_exception_spec_mismatch) |
| << hasImplicitExceptionSpec(Old); |
| if (Old->getLocation().isValid()) |
| Diag(Old->getLocation(), diag::note_previous_declaration); |
| } |
| return false; |
| } |
| |
| // The failure was something other than an missing exception |
| // specification; return an error, except in MS mode where this is a warning. |
| if (!MissingExceptionSpecification) |
| return ReturnValueOnError; |
| |
| const FunctionProtoType *NewProto = |
| New->getType()->castAs<FunctionProtoType>(); |
| |
| // The new function declaration is only missing an empty exception |
| // specification "throw()". If the throw() specification came from a |
| // function in a system header that has C linkage, just add an empty |
| // exception specification to the "new" declaration. Note that C library |
| // implementations are permitted to add these nothrow exception |
| // specifications. |
| // |
| // Likewise if the old function is a builtin. |
| if (MissingEmptyExceptionSpecification && NewProto && |
| (Old->getLocation().isInvalid() || |
| Context.getSourceManager().isInSystemHeader(Old->getLocation()) || |
| Old->getBuiltinID()) && |
| Old->isExternC()) { |
| New->setType(Context.getFunctionType( |
| NewProto->getReturnType(), NewProto->getParamTypes(), |
| NewProto->getExtProtoInfo().withExceptionSpec(EST_DynamicNone))); |
| return false; |
| } |
| |
| const FunctionProtoType *OldProto = |
| Old->getType()->castAs<FunctionProtoType>(); |
| |
| FunctionProtoType::ExceptionSpecInfo ESI = OldProto->getExceptionSpecType(); |
| if (ESI.Type == EST_Dynamic) { |
| // FIXME: What if the exceptions are described in terms of the old |
| // prototype's parameters? |
| ESI.Exceptions = OldProto->exceptions(); |
| } |
| |
| if (ESI.Type == EST_NoexceptFalse) |
| ESI.Type = EST_None; |
| if (ESI.Type == EST_NoexceptTrue) |
| ESI.Type = EST_BasicNoexcept; |
| |
| // For dependent noexcept, we can't just take the expression from the old |
| // prototype. It likely contains references to the old prototype's parameters. |
| if (ESI.Type == EST_DependentNoexcept) { |
| New->setInvalidDecl(); |
| } else { |
| // Update the type of the function with the appropriate exception |
| // specification. |
| New->setType(Context.getFunctionType( |
| NewProto->getReturnType(), NewProto->getParamTypes(), |
| NewProto->getExtProtoInfo().withExceptionSpec(ESI))); |
| } |
| |
| if (getLangOpts().MSVCCompat && ESI.Type != EST_DependentNoexcept) { |
| // Allow missing exception specifications in redeclarations as an extension. |
| DiagID = diag::ext_ms_missing_exception_specification; |
| ReturnValueOnError = false; |
| } else if (New->isReplaceableGlobalAllocationFunction() && |
| ESI.Type != EST_DependentNoexcept) { |
| // Allow missing exception specifications in redeclarations as an extension, |
| // when declaring a replaceable global allocation function. |
| DiagID = diag::ext_missing_exception_specification; |
| ReturnValueOnError = false; |
| } else if (ESI.Type == EST_NoThrow) { |
| // Allow missing attribute 'nothrow' in redeclarations, since this is a very |
| // common omission. |
| DiagID = diag::ext_missing_exception_specification; |
| ReturnValueOnError = false; |
| } else { |
| DiagID = diag::err_missing_exception_specification; |
| ReturnValueOnError = true; |
| } |
| |
| // Warn about the lack of exception specification. |
| SmallString<128> ExceptionSpecString; |
| llvm::raw_svector_ostream OS(ExceptionSpecString); |
| switch (OldProto->getExceptionSpecType()) { |
| case EST_DynamicNone: |
| OS << "throw()"; |
| break; |
| |
| case EST_Dynamic: { |
| OS << "throw("; |
| bool OnFirstException = true; |
| for (const auto &E : OldProto->exceptions()) { |
| if (OnFirstException) |
| OnFirstException = false; |
| else |
| OS << ", "; |
| |
| OS << E.getAsString(getPrintingPolicy()); |
| } |
| OS << ")"; |
| break; |
| } |
| |
| case EST_BasicNoexcept: |
| OS << "noexcept"; |
| break; |
| |
| case EST_DependentNoexcept: |
| case EST_NoexceptFalse: |
| case EST_NoexceptTrue: |
| OS << "noexcept("; |
| assert(OldProto->getNoexceptExpr() != nullptr && "Expected non-null Expr"); |
| OldProto->getNoexceptExpr()->printPretty(OS, nullptr, getPrintingPolicy()); |
| OS << ")"; |
| break; |
| case EST_NoThrow: |
| OS <<"__attribute__((nothrow))"; |
| break; |
| case EST_None: |
| case EST_MSAny: |
| case EST_Unevaluated: |
| case EST_Uninstantiated: |
| case EST_Unparsed: |
| llvm_unreachable("This spec type is compatible with none."); |
| } |
| |
| SourceLocation FixItLoc; |
| if (TypeSourceInfo *TSInfo = New->getTypeSourceInfo()) { |
| TypeLoc TL = TSInfo->getTypeLoc().IgnoreParens(); |
| // FIXME: Preserve enough information so that we can produce a correct fixit |
| // location when there is a trailing return type. |
| if (auto FTLoc = TL.getAs<FunctionProtoTypeLoc>()) |
| if (!FTLoc.getTypePtr()->hasTrailingReturn()) |
| FixItLoc = getLocForEndOfToken(FTLoc.getLocalRangeEnd()); |
| } |
| |
| if (FixItLoc.isInvalid()) |
| Diag(New->getLocation(), DiagID) |
| << New << OS.str(); |
| else { |
| Diag(New->getLocation(), DiagID) |
| << New << OS.str() |
| << FixItHint::CreateInsertion(FixItLoc, " " + OS.str().str()); |
| } |
| |
| if (Old->getLocation().isValid()) |
| Diag(Old->getLocation(), diag::note_previous_declaration); |
| |
| return ReturnValueOnError; |
| } |
| |
| /// CheckEquivalentExceptionSpec - Check if the two types have equivalent |
| /// exception specifications. Exception specifications are equivalent if |
| /// they allow exactly the same set of exception types. It does not matter how |
| /// that is achieved. See C++ [except.spec]p2. |
| bool Sema::CheckEquivalentExceptionSpec( |
| const FunctionProtoType *Old, SourceLocation OldLoc, |
| const FunctionProtoType *New, SourceLocation NewLoc) { |
| if (!getLangOpts().CXXExceptions) |
| return false; |
| |
| unsigned DiagID = diag::err_mismatched_exception_spec; |
| if (getLangOpts().MSVCCompat) |
| DiagID = diag::ext_mismatched_exception_spec; |
| bool Result = CheckEquivalentExceptionSpecImpl( |
| *this, PDiag(DiagID), PDiag(diag::note_previous_declaration), |
| Old, OldLoc, New, NewLoc); |
| |
| // In Microsoft mode, mismatching exception specifications just cause a warning. |
| if (getLangOpts().MSVCCompat) |
| return false; |
| return Result; |
| } |
| |
| /// CheckEquivalentExceptionSpec - Check if the two types have compatible |
| /// exception specifications. See C++ [except.spec]p3. |
| /// |
| /// \return \c false if the exception specifications match, \c true if there is |
| /// a problem. If \c true is returned, either a diagnostic has already been |
| /// produced or \c *MissingExceptionSpecification is set to \c true. |
| static bool CheckEquivalentExceptionSpecImpl( |
| Sema &S, const PartialDiagnostic &DiagID, const PartialDiagnostic &NoteID, |
| const FunctionProtoType *Old, SourceLocation OldLoc, |
| const FunctionProtoType *New, SourceLocation NewLoc, |
| bool *MissingExceptionSpecification, |
| bool *MissingEmptyExceptionSpecification, |
| bool AllowNoexceptAllMatchWithNoSpec, bool IsOperatorNew) { |
| if (MissingExceptionSpecification) |
| *MissingExceptionSpecification = false; |
| |
| if (MissingEmptyExceptionSpecification) |
| *MissingEmptyExceptionSpecification = false; |
| |
| Old = S.ResolveExceptionSpec(NewLoc, Old); |
| if (!Old) |
| return false; |
| New = S.ResolveExceptionSpec(NewLoc, New); |
| if (!New) |
| return false; |
| |
| // C++0x [except.spec]p3: Two exception-specifications are compatible if: |
| // - both are non-throwing, regardless of their form, |
| // - both have the form noexcept(constant-expression) and the constant- |
| // expressions are equivalent, |
| // - both are dynamic-exception-specifications that have the same set of |
| // adjusted types. |
| // |
| // C++0x [except.spec]p12: An exception-specification is non-throwing if it is |
| // of the form throw(), noexcept, or noexcept(constant-expression) where the |
| // constant-expression yields true. |
| // |
| // C++0x [except.spec]p4: If any declaration of a function has an exception- |
| // specifier that is not a noexcept-specification allowing all exceptions, |
| // all declarations [...] of that function shall have a compatible |
| // exception-specification. |
| // |
| // That last point basically means that noexcept(false) matches no spec. |
| // It's considered when AllowNoexceptAllMatchWithNoSpec is true. |
| |
| ExceptionSpecificationType OldEST = Old->getExceptionSpecType(); |
| ExceptionSpecificationType NewEST = New->getExceptionSpecType(); |
| |
| assert(!isUnresolvedExceptionSpec(OldEST) && |
| !isUnresolvedExceptionSpec(NewEST) && |
| "Shouldn't see unknown exception specifications here"); |
| |
| CanThrowResult OldCanThrow = Old->canThrow(); |
| CanThrowResult NewCanThrow = New->canThrow(); |
| |
| // Any non-throwing specifications are compatible. |
| if (OldCanThrow == CT_Cannot && NewCanThrow == CT_Cannot) |
| return false; |
| |
| // Any throws-anything specifications are usually compatible. |
| if (OldCanThrow == CT_Can && OldEST != EST_Dynamic && |
| NewCanThrow == CT_Can && NewEST != EST_Dynamic) { |
| // The exception is that the absence of an exception specification only |
| // matches noexcept(false) for functions, as described above. |
| if (!AllowNoexceptAllMatchWithNoSpec && |
| ((OldEST == EST_None && NewEST == EST_NoexceptFalse) || |
| (OldEST == EST_NoexceptFalse && NewEST == EST_None))) { |
| // This is the disallowed case. |
| } else { |
| return false; |
| } |
| } |
| |
| // C++14 [except.spec]p3: |
| // Two exception-specifications are compatible if [...] both have the form |
| // noexcept(constant-expression) and the constant-expressions are equivalent |
| if (OldEST == EST_DependentNoexcept && NewEST == EST_DependentNoexcept) { |
| llvm::FoldingSetNodeID OldFSN, NewFSN; |
| Old->getNoexceptExpr()->Profile(OldFSN, S.Context, true); |
| New->getNoexceptExpr()->Profile(NewFSN, S.Context, true); |
| if (OldFSN == NewFSN) |
| return false; |
| } |
| |
| // Dynamic exception specifications with the same set of adjusted types |
| // are compatible. |
| if (OldEST == EST_Dynamic && NewEST == EST_Dynamic) { |
| bool Success = true; |
| // Both have a dynamic exception spec. Collect the first set, then compare |
| // to the second. |
| llvm::SmallPtrSet<CanQualType, 8> OldTypes, NewTypes; |
| for (const auto &I : Old->exceptions()) |
| OldTypes.insert(S.Context.getCanonicalType(I).getUnqualifiedType()); |
| |
| for (const auto &I : New->exceptions()) { |
| CanQualType TypePtr = S.Context.getCanonicalType(I).getUnqualifiedType(); |
| if (OldTypes.count(TypePtr)) |
| NewTypes.insert(TypePtr); |
| else { |
| Success = false; |
| break; |
| } |
| } |
| |
| if (Success && OldTypes.size() == NewTypes.size()) |
| return false; |
| } |
| |
| // As a special compatibility feature, under C++0x we accept no spec and |
| // throw(std::bad_alloc) as equivalent for operator new and operator new[]. |
| // This is because the implicit declaration changed, but old code would break. |
| if (S.getLangOpts().CPlusPlus11 && IsOperatorNew) { |
| const FunctionProtoType *WithExceptions = nullptr; |
| if (OldEST == EST_None && NewEST == EST_Dynamic) |
| WithExceptions = New; |
| else if (OldEST == EST_Dynamic && NewEST == EST_None) |
| WithExceptions = Old; |
| if (WithExceptions && WithExceptions->getNumExceptions() == 1) { |
| // One has no spec, the other throw(something). If that something is |
| // std::bad_alloc, all conditions are met. |
| QualType Exception = *WithExceptions->exception_begin(); |
| if (CXXRecordDecl *ExRecord = Exception->getAsCXXRecordDecl()) { |
| IdentifierInfo* Name = ExRecord->getIdentifier(); |
| if (Name && Name->getName() == "bad_alloc") { |
| // It's called bad_alloc, but is it in std? |
| if (ExRecord->isInStdNamespace()) { |
| return false; |
| } |
| } |
| } |
| } |
| } |
| |
| // If the caller wants to handle the case that the new function is |
| // incompatible due to a missing exception specification, let it. |
| if (MissingExceptionSpecification && OldEST != EST_None && |
| NewEST == EST_None) { |
| // The old type has an exception specification of some sort, but |
| // the new type does not. |
| *MissingExceptionSpecification = true; |
| |
| if (MissingEmptyExceptionSpecification && OldCanThrow == CT_Cannot) { |
| // The old type has a throw() or noexcept(true) exception specification |
| // and the new type has no exception specification, and the caller asked |
| // to handle this itself. |
| *MissingEmptyExceptionSpecification = true; |
| } |
| |
| return true; |
| } |
| |
| S.Diag(NewLoc, DiagID); |
| if (NoteID.getDiagID() != 0 && OldLoc.isValid()) |
| S.Diag(OldLoc, NoteID); |
| return true; |
| } |
| |
| bool Sema::CheckEquivalentExceptionSpec(const PartialDiagnostic &DiagID, |
| const PartialDiagnostic &NoteID, |
| const FunctionProtoType *Old, |
| SourceLocation OldLoc, |
| const FunctionProtoType *New, |
| SourceLocation NewLoc) { |
| if (!getLangOpts().CXXExceptions) |
| return false; |
| return CheckEquivalentExceptionSpecImpl(*this, DiagID, NoteID, Old, OldLoc, |
| New, NewLoc); |
| } |
| |
| bool Sema::handlerCanCatch(QualType HandlerType, QualType ExceptionType) { |
| // [except.handle]p3: |
| // A handler is a match for an exception object of type E if: |
| |
| // HandlerType must be ExceptionType or derived from it, or pointer or |
| // reference to such types. |
| const ReferenceType *RefTy = HandlerType->getAs<ReferenceType>(); |
| if (RefTy) |
| HandlerType = RefTy->getPointeeType(); |
| |
| // -- the handler is of type cv T or cv T& and E and T are the same type |
| if (Context.hasSameUnqualifiedType(ExceptionType, HandlerType)) |
| return true; |
| |
| // FIXME: ObjC pointer types? |
| if (HandlerType->isPointerType() || HandlerType->isMemberPointerType()) { |
| if (RefTy && (!HandlerType.isConstQualified() || |
| HandlerType.isVolatileQualified())) |
| return false; |
| |
| // -- the handler is of type cv T or const T& where T is a pointer or |
| // pointer to member type and E is std::nullptr_t |
| if (ExceptionType->isNullPtrType()) |
| return true; |
| |
| // -- the handler is of type cv T or const T& where T is a pointer or |
| // pointer to member type and E is a pointer or pointer to member type |
| // that can be converted to T by one or more of |
| // -- a qualification conversion |
| // -- a function pointer conversion |
| bool LifetimeConv; |
| QualType Result; |
| // FIXME: Should we treat the exception as catchable if a lifetime |
| // conversion is required? |
| if (IsQualificationConversion(ExceptionType, HandlerType, false, |
| LifetimeConv) || |
| IsFunctionConversion(ExceptionType, HandlerType, Result)) |
| return true; |
| |
| // -- a standard pointer conversion [...] |
| if (!ExceptionType->isPointerType() || !HandlerType->isPointerType()) |
| return false; |
| |
| // Handle the "qualification conversion" portion. |
| Qualifiers EQuals, HQuals; |
| ExceptionType = Context.getUnqualifiedArrayType( |
| ExceptionType->getPointeeType(), EQuals); |
| HandlerType = Context.getUnqualifiedArrayType( |
| HandlerType->getPointeeType(), HQuals); |
| if (!HQuals.compatiblyIncludes(EQuals)) |
| return false; |
| |
| if (HandlerType->isVoidType() && ExceptionType->isObjectType()) |
| return true; |
| |
| // The only remaining case is a derived-to-base conversion. |
| } |
| |
| // -- the handler is of type cg T or cv T& and T is an unambiguous public |
| // base class of E |
| if (!ExceptionType->isRecordType() || !HandlerType->isRecordType()) |
| return false; |
| CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, |
| /*DetectVirtual=*/false); |
| if (!IsDerivedFrom(SourceLocation(), ExceptionType, HandlerType, Paths) || |
| Paths.isAmbiguous(Context.getCanonicalType(HandlerType))) |
| return false; |
| |
| // Do this check from a context without privileges. |
| switch (CheckBaseClassAccess(SourceLocation(), HandlerType, ExceptionType, |
| Paths.front(), |
| /*Diagnostic*/ 0, |
| /*ForceCheck*/ true, |
| /*ForceUnprivileged*/ true)) { |
| case AR_accessible: return true; |
| case AR_inaccessible: return false; |
| case AR_dependent: |
| llvm_unreachable("access check dependent for unprivileged context"); |
| case AR_delayed: |
| llvm_unreachable("access check delayed in non-declaration"); |
| } |
| llvm_unreachable("unexpected access check result"); |
| } |
| |
| /// CheckExceptionSpecSubset - Check whether the second function type's |
| /// exception specification is a subset (or equivalent) of the first function |
| /// type. This is used by override and pointer assignment checks. |
| bool Sema::CheckExceptionSpecSubset(const PartialDiagnostic &DiagID, |
| const PartialDiagnostic &NestedDiagID, |
| const PartialDiagnostic &NoteID, |
| const PartialDiagnostic &NoThrowDiagID, |
| const FunctionProtoType *Superset, |
| SourceLocation SuperLoc, |
| const FunctionProtoType *Subset, |
| SourceLocation SubLoc) { |
| |
| // Just auto-succeed under -fno-exceptions. |
| if (!getLangOpts().CXXExceptions) |
| return false; |
| |
| // FIXME: As usual, we could be more specific in our error messages, but |
| // that better waits until we've got types with source locations. |
| |
| if (!SubLoc.isValid()) |
| SubLoc = SuperLoc; |
| |
| // Resolve the exception specifications, if needed. |
| Superset = ResolveExceptionSpec(SuperLoc, Superset); |
| if (!Superset) |
| return false; |
| Subset = ResolveExceptionSpec(SubLoc, Subset); |
| if (!Subset) |
| return false; |
| |
| ExceptionSpecificationType SuperEST = Superset->getExceptionSpecType(); |
| ExceptionSpecificationType SubEST = Subset->getExceptionSpecType(); |
| assert(!isUnresolvedExceptionSpec(SuperEST) && |
| !isUnresolvedExceptionSpec(SubEST) && |
| "Shouldn't see unknown exception specifications here"); |
| |
| // If there are dependent noexcept specs, assume everything is fine. Unlike |
| // with the equivalency check, this is safe in this case, because we don't |
| // want to merge declarations. Checks after instantiation will catch any |
| // omissions we make here. |
| if (SuperEST == EST_DependentNoexcept || SubEST == EST_DependentNoexcept) |
| return false; |
| |
| CanThrowResult SuperCanThrow = Superset->canThrow(); |
| CanThrowResult SubCanThrow = Subset->canThrow(); |
| |
| // If the superset contains everything or the subset contains nothing, we're |
| // done. |
| if ((SuperCanThrow == CT_Can && SuperEST != EST_Dynamic) || |
| SubCanThrow == CT_Cannot) |
| return CheckParamExceptionSpec(NestedDiagID, NoteID, Superset, SuperLoc, |
| Subset, SubLoc); |
| |
| // Allow __declspec(nothrow) to be missing on redeclaration as an extension in |
| // some cases. |
| if (NoThrowDiagID.getDiagID() != 0 && SubCanThrow == CT_Can && |
| SuperCanThrow == CT_Cannot && SuperEST == EST_NoThrow) { |
| Diag(SubLoc, NoThrowDiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(SuperLoc, NoteID); |
| return true; |
| } |
| |
| // If the subset contains everything or the superset contains nothing, we've |
| // failed. |
| if ((SubCanThrow == CT_Can && SubEST != EST_Dynamic) || |
| SuperCanThrow == CT_Cannot) { |
| Diag(SubLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(SuperLoc, NoteID); |
| return true; |
| } |
| |
| assert(SuperEST == EST_Dynamic && SubEST == EST_Dynamic && |
| "Exception spec subset: non-dynamic case slipped through."); |
| |
| // Neither contains everything or nothing. Do a proper comparison. |
| for (QualType SubI : Subset->exceptions()) { |
| if (const ReferenceType *RefTy = SubI->getAs<ReferenceType>()) |
| SubI = RefTy->getPointeeType(); |
| |
| // Make sure it's in the superset. |
| bool Contained = false; |
| for (QualType SuperI : Superset->exceptions()) { |
| // [except.spec]p5: |
| // the target entity shall allow at least the exceptions allowed by the |
| // source |
| // |
| // We interpret this as meaning that a handler for some target type would |
| // catch an exception of each source type. |
| if (handlerCanCatch(SuperI, SubI)) { |
| Contained = true; |
| break; |
| } |
| } |
| if (!Contained) { |
| Diag(SubLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(SuperLoc, NoteID); |
| return true; |
| } |
| } |
| // We've run half the gauntlet. |
| return CheckParamExceptionSpec(NestedDiagID, NoteID, Superset, SuperLoc, |
| Subset, SubLoc); |
| } |
| |
| static bool |
| CheckSpecForTypesEquivalent(Sema &S, const PartialDiagnostic &DiagID, |
| const PartialDiagnostic &NoteID, QualType Target, |
| SourceLocation TargetLoc, QualType Source, |
| SourceLocation SourceLoc) { |
| const FunctionProtoType *TFunc = GetUnderlyingFunction(Target); |
| if (!TFunc) |
| return false; |
| const FunctionProtoType *SFunc = GetUnderlyingFunction(Source); |
| if (!SFunc) |
| return false; |
| |
| return S.CheckEquivalentExceptionSpec(DiagID, NoteID, TFunc, TargetLoc, |
| SFunc, SourceLoc); |
| } |
| |
| /// CheckParamExceptionSpec - Check if the parameter and return types of the |
| /// two functions have equivalent exception specs. This is part of the |
| /// assignment and override compatibility check. We do not check the parameters |
| /// of parameter function pointers recursively, as no sane programmer would |
| /// even be able to write such a function type. |
| bool Sema::CheckParamExceptionSpec(const PartialDiagnostic &DiagID, |
| const PartialDiagnostic &NoteID, |
| const FunctionProtoType *Target, |
| SourceLocation TargetLoc, |
| const FunctionProtoType *Source, |
| SourceLocation SourceLoc) { |
| auto RetDiag = DiagID; |
| RetDiag << 0; |
| if (CheckSpecForTypesEquivalent( |
| *this, RetDiag, PDiag(), |
| Target->getReturnType(), TargetLoc, Source->getReturnType(), |
| SourceLoc)) |
| return true; |
| |
| // We shouldn't even be testing this unless the arguments are otherwise |
| // compatible. |
| assert(Target->getNumParams() == Source->getNumParams() && |
| "Functions have different argument counts."); |
| for (unsigned i = 0, E = Target->getNumParams(); i != E; ++i) { |
| auto ParamDiag = DiagID; |
| ParamDiag << 1; |
| if (CheckSpecForTypesEquivalent( |
| *this, ParamDiag, PDiag(), |
| Target->getParamType(i), TargetLoc, Source->getParamType(i), |
| SourceLoc)) |
| return true; |
| } |
| return false; |
| } |
| |
| bool Sema::CheckExceptionSpecCompatibility(Expr *From, QualType ToType) { |
| // First we check for applicability. |
| // Target type must be a function, function pointer or function reference. |
| const FunctionProtoType *ToFunc = GetUnderlyingFunction(ToType); |
| if (!ToFunc || ToFunc->hasDependentExceptionSpec()) |
| return false; |
| |
| // SourceType must be a function or function pointer. |
| const FunctionProtoType *FromFunc = GetUnderlyingFunction(From->getType()); |
| if (!FromFunc || FromFunc->hasDependentExceptionSpec()) |
| return false; |
| |
| unsigned DiagID = diag::err_incompatible_exception_specs; |
| unsigned NestedDiagID = diag::err_deep_exception_specs_differ; |
| // This is not an error in C++17 onwards, unless the noexceptness doesn't |
| // match, but in that case we have a full-on type mismatch, not just a |
| // type sugar mismatch. |
| if (getLangOpts().CPlusPlus17) { |
| DiagID = diag::warn_incompatible_exception_specs; |
| NestedDiagID = diag::warn_deep_exception_specs_differ; |
| } |
| |
| // Now we've got the correct types on both sides, check their compatibility. |
| // This means that the source of the conversion can only throw a subset of |
| // the exceptions of the target, and any exception specs on arguments or |
| // return types must be equivalent. |
| // |
| // FIXME: If there is a nested dependent exception specification, we should |
| // not be checking it here. This is fine: |
| // template<typename T> void f() { |
| // void (*p)(void (*) throw(T)); |
| // void (*q)(void (*) throw(int)) = p; |
| // } |
| // ... because it might be instantiated with T=int. |
| return CheckExceptionSpecSubset( |
| PDiag(DiagID), PDiag(NestedDiagID), PDiag(), PDiag(), ToFunc, |
| From->getSourceRange().getBegin(), FromFunc, SourceLocation()) && |
| !getLangOpts().CPlusPlus17; |
| } |
| |
| bool Sema::CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New, |
| const CXXMethodDecl *Old) { |
| // If the new exception specification hasn't been parsed yet, skip the check. |
| // We'll get called again once it's been parsed. |
| if (New->getType()->castAs<FunctionProtoType>()->getExceptionSpecType() == |
| EST_Unparsed) |
| return false; |
| |
| // Don't check uninstantiated template destructors at all. We can only |
| // synthesize correct specs after the template is instantiated. |
| if (isa<CXXDestructorDecl>(New) && New->getParent()->isDependentType()) |
| return false; |
| |
| // If the old exception specification hasn't been parsed yet, or the new |
| // exception specification can't be computed yet, remember that we need to |
| // perform this check when we get to the end of the outermost |
| // lexically-surrounding class. |
| if (exceptionSpecNotKnownYet(Old) || exceptionSpecNotKnownYet(New)) { |
| DelayedOverridingExceptionSpecChecks.push_back({New, Old}); |
| return false; |
| } |
| |
| unsigned DiagID = diag::err_override_exception_spec; |
| if (getLangOpts().MSVCCompat) |
| DiagID = diag::ext_override_exception_spec; |
| return CheckExceptionSpecSubset(PDiag(DiagID), |
| PDiag(diag::err_deep_exception_specs_differ), |
| PDiag(diag::note_overridden_virtual_function), |
| PDiag(diag::ext_override_exception_spec), |
| Old->getType()->castAs<FunctionProtoType>(), |
| Old->getLocation(), |
| New->getType()->castAs<FunctionProtoType>(), |
| New->getLocation()); |
| } |
| |
| static CanThrowResult canSubStmtsThrow(Sema &Self, const Stmt *S) { |
| CanThrowResult R = CT_Cannot; |
| for (const Stmt *SubStmt : S->children()) { |
| if (!SubStmt) |
| continue; |
| R = mergeCanThrow(R, Self.canThrow(SubStmt)); |
| if (R == CT_Can) |
| break; |
| } |
| return R; |
| } |
| |
| CanThrowResult Sema::canCalleeThrow(Sema &S, const Expr *E, const Decl *D, |
| SourceLocation Loc) { |
| // As an extension, we assume that __attribute__((nothrow)) functions don't |
| // throw. |
| if (D && isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>()) |
| return CT_Cannot; |
| |
| QualType T; |
| |
| // In C++1z, just look at the function type of the callee. |
| if (S.getLangOpts().CPlusPlus17 && E && isa<CallExpr>(E)) { |
| E = cast<CallExpr>(E)->getCallee(); |
| T = E->getType(); |
| if (T->isSpecificPlaceholderType(BuiltinType::BoundMember)) { |
| // Sadly we don't preserve the actual type as part of the "bound member" |
| // placeholder, so we need to reconstruct it. |
| E = E->IgnoreParenImpCasts(); |
| |
| // Could be a call to a pointer-to-member or a plain member access. |
| if (auto *Op = dyn_cast<BinaryOperator>(E)) { |
| assert(Op->getOpcode() == BO_PtrMemD || Op->getOpcode() == BO_PtrMemI); |
| T = Op->getRHS()->getType() |
| ->castAs<MemberPointerType>()->getPointeeType(); |
| } else { |
| T = cast<MemberExpr>(E)->getMemberDecl()->getType(); |
| } |
| } |
| } else if (const ValueDecl *VD = dyn_cast_or_null<ValueDecl>(D)) |
| T = VD->getType(); |
| else |
| // If we have no clue what we're calling, assume the worst. |
| return CT_Can; |
| |
| const FunctionProtoType *FT; |
| if ((FT = T->getAs<FunctionProtoType>())) { |
| } else if (const PointerType *PT = T->getAs<PointerType>()) |
| FT = PT->getPointeeType()->getAs<FunctionProtoType>(); |
| else if (const ReferenceType *RT = T->getAs<ReferenceType>()) |
| FT = RT->getPointeeType()->getAs<FunctionProtoType>(); |
| else if (const MemberPointerType *MT = T->getAs<MemberPointerType>()) |
| FT = MT->getPointeeType()->getAs<FunctionProtoType>(); |
| else if (const BlockPointerType *BT = T->getAs<BlockPointerType>()) |
| FT = BT->getPointeeType()->getAs<FunctionProtoType>(); |
| |
| if (!FT) |
| return CT_Can; |
| |
| if (Loc.isValid() || (Loc.isInvalid() && E)) |
| FT = S.ResolveExceptionSpec(Loc.isInvalid() ? E->getBeginLoc() : Loc, FT); |
| if (!FT) |
| return CT_Can; |
| |
| return FT->canThrow(); |
| } |
| |
| static CanThrowResult canVarDeclThrow(Sema &Self, const VarDecl *VD) { |
| CanThrowResult CT = CT_Cannot; |
| |
| // Initialization might throw. |
| if (!VD->isUsableInConstantExpressions(Self.Context)) |
| if (const Expr *Init = VD->getInit()) |
| CT = mergeCanThrow(CT, Self.canThrow(Init)); |
| |
| // Destructor might throw. |
| if (VD->needsDestruction(Self.Context) == QualType::DK_cxx_destructor) { |
| if (auto *RD = |
| VD->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) { |
| if (auto *Dtor = RD->getDestructor()) { |
| CT = mergeCanThrow( |
| CT, Sema::canCalleeThrow(Self, nullptr, Dtor, VD->getLocation())); |
| } |
| } |
| } |
| |
| // If this is a decomposition declaration, bindings might throw. |
| if (auto *DD = dyn_cast<DecompositionDecl>(VD)) |
| for (auto *B : DD->bindings()) |
| if (auto *HD = B->getHoldingVar()) |
| CT = mergeCanThrow(CT, canVarDeclThrow(Self, HD)); |
| |
| return CT; |
| } |
| |
| static CanThrowResult canDynamicCastThrow(const CXXDynamicCastExpr *DC) { |
| if (DC->isTypeDependent()) |
| return CT_Dependent; |
| |
| if (!DC->getTypeAsWritten()->isReferenceType()) |
| return CT_Cannot; |
| |
| if (DC->getSubExpr()->isTypeDependent()) |
| return CT_Dependent; |
| |
| return DC->getCastKind() == clang::CK_Dynamic? CT_Can : CT_Cannot; |
| } |
| |
| static CanThrowResult canTypeidThrow(Sema &S, const CXXTypeidExpr *DC) { |
| if (DC->isTypeOperand()) |
| return CT_Cannot; |
| |
| Expr *Op = DC->getExprOperand(); |
| if (Op->isTypeDependent()) |
| return CT_Dependent; |
| |
| const RecordType *RT = Op->getType()->getAs<RecordType>(); |
| if (!RT) |
| return CT_Cannot; |
| |
| if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic()) |
| return CT_Cannot; |
| |
| if (Op->Classify(S.Context).isPRValue()) |
| return CT_Cannot; |
| |
| return CT_Can; |
| } |
| |
| CanThrowResult Sema::canThrow(const Stmt *S) { |
| // C++ [expr.unary.noexcept]p3: |
| // [Can throw] if in a potentially-evaluated context the expression would |
| // contain: |
| switch (S->getStmtClass()) { |
| case Expr::ConstantExprClass: |
| return canThrow(cast<ConstantExpr>(S)->getSubExpr()); |
| |
| case Expr::CXXThrowExprClass: |
| // - a potentially evaluated throw-expression |
| return CT_Can; |
| |
| case Expr::CXXDynamicCastExprClass: { |
| // - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v), |
| // where T is a reference type, that requires a run-time check |
| auto *CE = cast<CXXDynamicCastExpr>(S); |
| // FIXME: Properly determine whether a variably-modified type can throw. |
| if (CE->getType()->isVariablyModifiedType()) |
| return CT_Can; |
| CanThrowResult CT = canDynamicCastThrow(CE); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, CE)); |
| } |
| |
| case Expr::CXXTypeidExprClass: |
| // - a potentially evaluated typeid expression applied to a glvalue |
| // expression whose type is a polymorphic class type |
| return canTypeidThrow(*this, cast<CXXTypeidExpr>(S)); |
| |
| // - a potentially evaluated call to a function, member function, function |
| // pointer, or member function pointer that does not have a non-throwing |
| // exception-specification |
| case Expr::CallExprClass: |
| case Expr::CXXMemberCallExprClass: |
| case Expr::CXXOperatorCallExprClass: |
| case Expr::UserDefinedLiteralClass: { |
| const CallExpr *CE = cast<CallExpr>(S); |
| CanThrowResult CT; |
| if (CE->isTypeDependent()) |
| CT = CT_Dependent; |
| else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens())) |
| CT = CT_Cannot; |
| else |
| CT = canCalleeThrow(*this, CE, CE->getCalleeDecl()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, CE)); |
| } |
| |
| case Expr::CXXConstructExprClass: |
| case Expr::CXXTemporaryObjectExprClass: { |
| auto *CE = cast<CXXConstructExpr>(S); |
| // FIXME: Properly determine whether a variably-modified type can throw. |
| if (CE->getType()->isVariablyModifiedType()) |
| return CT_Can; |
| CanThrowResult CT = canCalleeThrow(*this, CE, CE->getConstructor()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, CE)); |
| } |
| |
| case Expr::CXXInheritedCtorInitExprClass: { |
| auto *ICIE = cast<CXXInheritedCtorInitExpr>(S); |
| return canCalleeThrow(*this, ICIE, ICIE->getConstructor()); |
| } |
| |
| case Expr::LambdaExprClass: { |
| const LambdaExpr *Lambda = cast<LambdaExpr>(S); |
| CanThrowResult CT = CT_Cannot; |
| for (LambdaExpr::const_capture_init_iterator |
| Cap = Lambda->capture_init_begin(), |
| CapEnd = Lambda->capture_init_end(); |
| Cap != CapEnd; ++Cap) |
| CT = mergeCanThrow(CT, canThrow(*Cap)); |
| return CT; |
| } |
| |
| case Expr::CXXNewExprClass: { |
| auto *NE = cast<CXXNewExpr>(S); |
| CanThrowResult CT; |
| if (NE->isTypeDependent()) |
| CT = CT_Dependent; |
| else |
| CT = canCalleeThrow(*this, NE, NE->getOperatorNew()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, NE)); |
| } |
| |
| case Expr::CXXDeleteExprClass: { |
| auto *DE = cast<CXXDeleteExpr>(S); |
| CanThrowResult CT; |
| QualType DTy = DE->getDestroyedType(); |
| if (DTy.isNull() || DTy->isDependentType()) { |
| CT = CT_Dependent; |
| } else { |
| CT = canCalleeThrow(*this, DE, DE->getOperatorDelete()); |
| if (const RecordType *RT = DTy->getAs<RecordType>()) { |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); |
| const CXXDestructorDecl *DD = RD->getDestructor(); |
| if (DD) |
| CT = mergeCanThrow(CT, canCalleeThrow(*this, DE, DD)); |
| } |
| if (CT == CT_Can) |
| return CT; |
| } |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, DE)); |
| } |
| |
| case Expr::CXXBindTemporaryExprClass: { |
| auto *BTE = cast<CXXBindTemporaryExpr>(S); |
| // The bound temporary has to be destroyed again, which might throw. |
| CanThrowResult CT = |
| canCalleeThrow(*this, BTE, BTE->getTemporary()->getDestructor()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, BTE)); |
| } |
| |
| case Expr::PseudoObjectExprClass: { |
| auto *POE = cast<PseudoObjectExpr>(S); |
| CanThrowResult CT = CT_Cannot; |
| for (const Expr *E : POE->semantics()) { |
| CT = mergeCanThrow(CT, canThrow(E)); |
| if (CT == CT_Can) |
| break; |
| } |
| return CT; |
| } |
| |
| // ObjC message sends are like function calls, but never have exception |
| // specs. |
| case Expr::ObjCMessageExprClass: |
| case Expr::ObjCPropertyRefExprClass: |
| case Expr::ObjCSubscriptRefExprClass: |
| return CT_Can; |
| |
| // All the ObjC literals that are implemented as calls are |
| // potentially throwing unless we decide to close off that |
| // possibility. |
| case Expr::ObjCArrayLiteralClass: |
| case Expr::ObjCDictionaryLiteralClass: |
| case Expr::ObjCBoxedExprClass: |
| return CT_Can; |
| |
| // Many other things have subexpressions, so we have to test those. |
| // Some are simple: |
| case Expr::CoawaitExprClass: |
| case Expr::ConditionalOperatorClass: |
| case Expr::CoyieldExprClass: |
| case Expr::CXXRewrittenBinaryOperatorClass: |
| case Expr::CXXStdInitializerListExprClass: |
| case Expr::DesignatedInitExprClass: |
| case Expr::DesignatedInitUpdateExprClass: |
| case Expr::ExprWithCleanupsClass: |
| case Expr::ExtVectorElementExprClass: |
| case Expr::InitListExprClass: |
| case Expr::ArrayInitLoopExprClass: |
| case Expr::MemberExprClass: |
| case Expr::ObjCIsaExprClass: |
| case Expr::ObjCIvarRefExprClass: |
| case Expr::ParenExprClass: |
| case Expr::ParenListExprClass: |
| case Expr::ShuffleVectorExprClass: |
| case Expr::StmtExprClass: |
| case Expr::ConvertVectorExprClass: |
| case Expr::VAArgExprClass: |
| return canSubStmtsThrow(*this, S); |
| |
| case Expr::CompoundLiteralExprClass: |
| case Expr::CXXConstCastExprClass: |
| case Expr::CXXAddrspaceCastExprClass: |
| case Expr::CXXReinterpretCastExprClass: |
| case Expr::BuiltinBitCastExprClass: |
| // FIXME: Properly determine whether a variably-modified type can throw. |
| if (cast<Expr>(S)->getType()->isVariablyModifiedType()) |
| return CT_Can; |
| return canSubStmtsThrow(*this, S); |
| |
| // Some might be dependent for other reasons. |
| case Expr::ArraySubscriptExprClass: |
| case Expr::MatrixSubscriptExprClass: |
| case Expr::OMPArraySectionExprClass: |
| case Expr::OMPArrayShapingExprClass: |
| case Expr::OMPIteratorExprClass: |
| case Expr::BinaryOperatorClass: |
| case Expr::DependentCoawaitExprClass: |
| case Expr::CompoundAssignOperatorClass: |
| case Expr::CStyleCastExprClass: |
| case Expr::CXXStaticCastExprClass: |
| case Expr::CXXFunctionalCastExprClass: |
| case Expr::ImplicitCastExprClass: |
| case Expr::MaterializeTemporaryExprClass: |
| case Expr::UnaryOperatorClass: { |
| // FIXME: Properly determine whether a variably-modified type can throw. |
| if (auto *CE = dyn_cast<CastExpr>(S)) |
| if (CE->getType()->isVariablyModifiedType()) |
| return CT_Can; |
| CanThrowResult CT = |
| cast<Expr>(S)->isTypeDependent() ? CT_Dependent : CT_Cannot; |
| return mergeCanThrow(CT, canSubStmtsThrow(*this, S)); |
| } |
| |
| case Expr::CXXDefaultArgExprClass: |
| return canThrow(cast<CXXDefaultArgExpr>(S)->getExpr()); |
| |
| case Expr::CXXDefaultInitExprClass: |
| return canThrow(cast<CXXDefaultInitExpr>(S)->getExpr()); |
| |
| case Expr::ChooseExprClass: { |
| auto *CE = cast<ChooseExpr>(S); |
| if (CE->isTypeDependent() || CE->isValueDependent()) |
| return CT_Dependent; |
| return canThrow(CE->getChosenSubExpr()); |
| } |
| |
| case Expr::GenericSelectionExprClass: |
| if (cast<GenericSelectionExpr>(S)->isResultDependent()) |
| return CT_Dependent; |
| return canThrow(cast<GenericSelectionExpr>(S)->getResultExpr()); |
| |
| // Some expressions are always dependent. |
| case Expr::CXXDependentScopeMemberExprClass: |
| case Expr::CXXUnresolvedConstructExprClass: |
| case Expr::DependentScopeDeclRefExprClass: |
| case Expr::CXXFoldExprClass: |
| case Expr::RecoveryExprClass: |
| return CT_Dependent; |
| |
| case Expr::AsTypeExprClass: |
| case Expr::BinaryConditionalOperatorClass: |
| case Expr::BlockExprClass: |
| case Expr::CUDAKernelCallExprClass: |
| case Expr::DeclRefExprClass: |
| case Expr::ObjCBridgedCastExprClass: |
| case Expr::ObjCIndirectCopyRestoreExprClass: |
| case Expr::ObjCProtocolExprClass: |
| case Expr::ObjCSelectorExprClass: |
| case Expr::ObjCAvailabilityCheckExprClass: |
| case Expr::OffsetOfExprClass: |
| case Expr::PackExpansionExprClass: |
| case Expr::SubstNonTypeTemplateParmExprClass: |
| case Expr::SubstNonTypeTemplateParmPackExprClass: |
| case Expr::FunctionParmPackExprClass: |
| case Expr::UnaryExprOrTypeTraitExprClass: |
| case Expr::UnresolvedLookupExprClass: |
| case Expr::UnresolvedMemberExprClass: |
| case Expr::TypoExprClass: |
| // FIXME: Many of the above can throw. |
| return CT_Cannot; |
| |
| case Expr::AddrLabelExprClass: |
| case Expr::ArrayTypeTraitExprClass: |
| case Expr::AtomicExprClass: |
| case Expr::TypeTraitExprClass: |
| case Expr::CXXBoolLiteralExprClass: |
| case Expr::CXXNoexceptExprClass: |
| case Expr::CXXNullPtrLiteralExprClass: |
| case Expr::CXXPseudoDestructorExprClass: |
| case Expr::CXXScalarValueInitExprClass: |
| case Expr::CXXThisExprClass: |
| case Expr::CXXUuidofExprClass: |
| case Expr::CharacterLiteralClass: |
| case Expr::ExpressionTraitExprClass: |
| case Expr::FloatingLiteralClass: |
| case Expr::GNUNullExprClass: |
| case Expr::ImaginaryLiteralClass: |
| case Expr::ImplicitValueInitExprClass: |
| case Expr::IntegerLiteralClass: |
| case Expr::FixedPointLiteralClass: |
| case Expr::ArrayInitIndexExprClass: |
| case Expr::NoInitExprClass: |
| case Expr::ObjCEncodeExprClass: |
| case Expr::ObjCStringLiteralClass: |
| case Expr::ObjCBoolLiteralExprClass: |
| case Expr::OpaqueValueExprClass: |
| case Expr::PredefinedExprClass: |
| case Expr::SizeOfPackExprClass: |
| case Expr::StringLiteralClass: |
| case Expr::SourceLocExprClass: |
| case Expr::ConceptSpecializationExprClass: |
| case Expr::RequiresExprClass: |
| // These expressions can never throw. |
| return CT_Cannot; |
| |
| case Expr::MSPropertyRefExprClass: |
| case Expr::MSPropertySubscriptExprClass: |
| llvm_unreachable("Invalid class for expression"); |
| |
| // Most statements can throw if any substatement can throw. |
| case Stmt::AttributedStmtClass: |
| case Stmt::BreakStmtClass: |
| case Stmt::CapturedStmtClass: |
| case Stmt::CaseStmtClass: |
| case Stmt::CompoundStmtClass: |
| case Stmt::ContinueStmtClass: |
| case Stmt::CoreturnStmtClass: |
| case Stmt::CoroutineBodyStmtClass: |
| case Stmt::CXXCatchStmtClass: |
| case Stmt::CXXForRangeStmtClass: |
| case Stmt::DefaultStmtClass: |
| case Stmt::DoStmtClass: |
| case Stmt::ForStmtClass: |
| case Stmt::GCCAsmStmtClass: |
| case Stmt::GotoStmtClass: |
| case Stmt::IndirectGotoStmtClass: |
| case Stmt::LabelStmtClass: |
| case Stmt::MSAsmStmtClass: |
| case Stmt::MSDependentExistsStmtClass: |
| case Stmt::NullStmtClass: |
| case Stmt::ObjCAtCatchStmtClass: |
| case Stmt::ObjCAtFinallyStmtClass: |
| case Stmt::ObjCAtSynchronizedStmtClass: |
| case Stmt::ObjCAutoreleasePoolStmtClass: |
| case Stmt::ObjCForCollectionStmtClass: |
| case Stmt::OMPAtomicDirectiveClass: |
| case Stmt::OMPBarrierDirectiveClass: |
| case Stmt::OMPCancelDirectiveClass: |
| case Stmt::OMPCancellationPointDirectiveClass: |
| case Stmt::OMPCriticalDirectiveClass: |
| case Stmt::OMPDistributeDirectiveClass: |
| case Stmt::OMPDistributeParallelForDirectiveClass: |
| case Stmt::OMPDistributeParallelForSimdDirectiveClass: |
| case Stmt::OMPDistributeSimdDirectiveClass: |
| case Stmt::OMPFlushDirectiveClass: |
| case Stmt::OMPDepobjDirectiveClass: |
| case Stmt::OMPScanDirectiveClass: |
| case Stmt::OMPForDirectiveClass: |
| case Stmt::OMPForSimdDirectiveClass: |
| case Stmt::OMPMasterDirectiveClass: |
| case Stmt::OMPMasterTaskLoopDirectiveClass: |
| case Stmt::OMPMasterTaskLoopSimdDirectiveClass: |
| case Stmt::OMPOrderedDirectiveClass: |
| case Stmt::OMPCanonicalLoopClass: |
| case Stmt::OMPParallelDirectiveClass: |
| case Stmt::OMPParallelForDirectiveClass: |
| case Stmt::OMPParallelForSimdDirectiveClass: |
| case Stmt::OMPParallelMasterDirectiveClass: |
| case Stmt::OMPParallelMasterTaskLoopDirectiveClass: |
| case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass: |
| case Stmt::OMPParallelSectionsDirectiveClass: |
| case Stmt::OMPSectionDirectiveClass: |
| case Stmt::OMPSectionsDirectiveClass: |
| case Stmt::OMPSimdDirectiveClass: |
| case Stmt::OMPTileDirectiveClass: |
| case Stmt::OMPUnrollDirectiveClass: |
| case Stmt::OMPSingleDirectiveClass: |
| case Stmt::OMPTargetDataDirectiveClass: |
| case Stmt::OMPTargetDirectiveClass: |
| case Stmt::OMPTargetEnterDataDirectiveClass: |
| case Stmt::OMPTargetExitDataDirectiveClass: |
| case Stmt::OMPTargetParallelDirectiveClass: |
| case Stmt::OMPTargetParallelForDirectiveClass: |
| case Stmt::OMPTargetParallelForSimdDirectiveClass: |
| case Stmt::OMPTargetSimdDirectiveClass: |
| case Stmt::OMPTargetTeamsDirectiveClass: |
| case Stmt::OMPTargetTeamsDistributeDirectiveClass: |
| case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass: |
| case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass: |
| case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass: |
| case Stmt::OMPTargetUpdateDirectiveClass: |
| case Stmt::OMPTaskDirectiveClass: |
| case Stmt::OMPTaskgroupDirectiveClass: |
| case Stmt::OMPTaskLoopDirectiveClass: |
| case Stmt::OMPTaskLoopSimdDirectiveClass: |
| case Stmt::OMPTaskwaitDirectiveClass: |
| case Stmt::OMPTaskyieldDirectiveClass: |
| case Stmt::OMPTeamsDirectiveClass: |
| case Stmt::OMPTeamsDistributeDirectiveClass: |
| case Stmt::OMPTeamsDistributeParallelForDirectiveClass: |
| case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass: |
| case Stmt::OMPTeamsDistributeSimdDirectiveClass: |
| case Stmt::OMPInteropDirectiveClass: |
| case Stmt::OMPDispatchDirectiveClass: |
| case Stmt::OMPMaskedDirectiveClass: |
| case Stmt::OMPMetaDirectiveClass: |
| case Stmt::OMPGenericLoopDirectiveClass: |
| case Stmt::ReturnStmtClass: |
| case Stmt::SEHExceptStmtClass: |
| case Stmt::SEHFinallyStmtClass: |
| case Stmt::SEHLeaveStmtClass: |
| case Stmt::SEHTryStmtClass: |
| case Stmt::SwitchStmtClass: |
| case Stmt::WhileStmtClass: |
| return canSubStmtsThrow(*this, S); |
| |
| case Stmt::DeclStmtClass: { |
| CanThrowResult CT = CT_Cannot; |
| for (const Decl *D : cast<DeclStmt>(S)->decls()) { |
| if (auto *VD = dyn_cast<VarDecl>(D)) |
| CT = mergeCanThrow(CT, canVarDeclThrow(*this, VD)); |
| |
| // FIXME: Properly determine whether a variably-modified type can throw. |
| if (auto *TND = dyn_cast<TypedefNameDecl>(D)) |
| if (TND->getUnderlyingType()->isVariablyModifiedType()) |
| return CT_Can; |
| if (auto *VD = dyn_cast<ValueDecl>(D)) |
| if (VD->getType()->isVariablyModifiedType()) |
| return CT_Can; |
| } |
| return CT; |
| } |
| |
| case Stmt::IfStmtClass: { |
| auto *IS = cast<IfStmt>(S); |
| CanThrowResult CT = CT_Cannot; |
| if (const Stmt *Init = IS->getInit()) |
| CT = mergeCanThrow(CT, canThrow(Init)); |
| if (const Stmt *CondDS = IS->getConditionVariableDeclStmt()) |
| CT = mergeCanThrow(CT, canThrow(CondDS)); |
| CT = mergeCanThrow(CT, canThrow(IS->getCond())); |
| |
| // For 'if constexpr', consider only the non-discarded case. |
| // FIXME: We should add a DiscardedStmt marker to the AST. |
| if (Optional<const Stmt *> Case = IS->getNondiscardedCase(Context)) |
| return *Case ? mergeCanThrow(CT, canThrow(*Case)) : CT; |
| |
| CanThrowResult Then = canThrow(IS->getThen()); |
| CanThrowResult Else = IS->getElse() ? canThrow(IS->getElse()) : CT_Cannot; |
| if (Then == Else) |
| return mergeCanThrow(CT, Then); |
| |
| // For a dependent 'if constexpr', the result is dependent if it depends on |
| // the value of the condition. |
| return mergeCanThrow(CT, IS->isConstexpr() ? CT_Dependent |
| : mergeCanThrow(Then, Else)); |
| } |
| |
| case Stmt::CXXTryStmtClass: { |
| auto *TS = cast<CXXTryStmt>(S); |
| // try /*...*/ catch (...) { H } can throw only if H can throw. |
| // Any other try-catch can throw if any substatement can throw. |
| const CXXCatchStmt *FinalHandler = TS->getHandler(TS->getNumHandlers() - 1); |
| if (!FinalHandler->getExceptionDecl()) |
| return canThrow(FinalHandler->getHandlerBlock()); |
| return canSubStmtsThrow(*this, S); |
| } |
| |
| case Stmt::ObjCAtThrowStmtClass: |
| return CT_Can; |
| |
| case Stmt::ObjCAtTryStmtClass: { |
| auto *TS = cast<ObjCAtTryStmt>(S); |
| |
| // @catch(...) need not be last in Objective-C. Walk backwards until we |
| // see one or hit the @try. |
| CanThrowResult CT = CT_Cannot; |
| if (const Stmt *Finally = TS->getFinallyStmt()) |
| CT = mergeCanThrow(CT, canThrow(Finally)); |
| for (unsigned I = TS->getNumCatchStmts(); I != 0; --I) { |
| const ObjCAtCatchStmt *Catch = TS->getCatchStmt(I - 1); |
| CT = mergeCanThrow(CT, canThrow(Catch)); |
| // If we reach a @catch(...), no earlier exceptions can escape. |
| if (Catch->hasEllipsis()) |
| return CT; |
| } |
| |
| // Didn't find an @catch(...). Exceptions from the @try body can escape. |
| return mergeCanThrow(CT, canThrow(TS->getTryBody())); |
| } |
| |
| case Stmt::SYCLUniqueStableNameExprClass: |
| return CT_Cannot; |
| case Stmt::NoStmtClass: |
| llvm_unreachable("Invalid class for statement"); |
| } |
| llvm_unreachable("Bogus StmtClass"); |
| } |
| |
| } // end namespace clang |