| //===--- SemaExceptionSpec.cpp - C++ Exception Specifications ---*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file provides Sema routines for C++ exception specification testing. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Sema/SemaInternal.h" |
| #include "clang/AST/CXXInheritance.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/ExprCXX.h" |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Lex/Preprocessor.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>(); |
| } |
| |
| /// 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, const 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. |
| if (!(PointeeT->isRecordType() && |
| PointeeT->getAs<RecordType>()->isBeingDefined()) && |
| RequireCompleteType(Range.getBegin(), PointeeT, |
| diag::err_incomplete_in_exception_spec, Kind, 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) { |
| 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 (!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, cast<CXXMethodDecl>(SourceDecl)); |
| else |
| InstantiateExceptionSpec(Loc, SourceDecl); |
| |
| return SourceDecl->getType()->castAs<FunctionProtoType>(); |
| } |
| |
| /// 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; |
| |
| // If the user didn't declare the function, its exception specification must |
| // be implicit. |
| if (!Decl->getTypeSourceInfo()) |
| return true; |
| |
| const FunctionProtoType *Ty = |
| Decl->getTypeSourceInfo()->getType()->getAs<FunctionProtoType>(); |
| return !Ty->hasExceptionSpec(); |
| } |
| |
| bool Sema::CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New) { |
| 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; |
| if (getLangOpts().MicrosoftExt) |
| DiagID = diag::warn_mismatched_exception_spec; |
| |
| // Check the types as written: they must match before any exception |
| // specification adjustment is applied. |
| if (!CheckEquivalentExceptionSpec( |
| 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 && |
| hasImplicitExceptionSpec(Old) != hasImplicitExceptionSpec(New)) { |
| Diag(New->getLocation(), diag::ext_implicit_exception_spec_mismatch) |
| << hasImplicitExceptionSpec(Old); |
| if (!Old->getLocation().isInvalid()) |
| Diag(Old->getLocation(), diag::note_previous_declaration); |
| } |
| return false; |
| } |
| |
| // The failure was something other than an missing exception |
| // specification; return an error. |
| if (!MissingExceptionSpecification) |
| return true; |
| |
| 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. This is an |
| // egregious workaround for glibc, which adds throw() specifications |
| // to many libc functions as an optimization. Unfortunately, that |
| // optimization isn't permitted by the C++ standard, so we're forced |
| // to work around it here. |
| if (MissingEmptyExceptionSpecification && NewProto && |
| (Old->getLocation().isInvalid() || |
| Context.getSourceManager().isInSystemHeader(Old->getLocation())) && |
| Old->isExternC()) { |
| FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo(); |
| EPI.ExceptionSpecType = EST_DynamicNone; |
| QualType NewType = Context.getFunctionType(NewProto->getResultType(), |
| NewProto->getArgTypes(), EPI); |
| New->setType(NewType); |
| return false; |
| } |
| |
| const FunctionProtoType *OldProto = |
| Old->getType()->castAs<FunctionProtoType>(); |
| |
| FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo(); |
| EPI.ExceptionSpecType = OldProto->getExceptionSpecType(); |
| if (EPI.ExceptionSpecType == EST_Dynamic) { |
| EPI.NumExceptions = OldProto->getNumExceptions(); |
| EPI.Exceptions = OldProto->exception_begin(); |
| } else if (EPI.ExceptionSpecType == EST_ComputedNoexcept) { |
| // FIXME: We can't just take the expression from the old prototype. It |
| // likely contains references to the old prototype's parameters. |
| } |
| |
| // Update the type of the function with the appropriate exception |
| // specification. |
| QualType NewType = Context.getFunctionType(NewProto->getResultType(), |
| NewProto->getArgTypes(), EPI); |
| New->setType(NewType); |
| |
| // 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 (FunctionProtoType::exception_iterator E = OldProto->exception_begin(), |
| EEnd = OldProto->exception_end(); |
| E != EEnd; |
| ++E) { |
| if (OnFirstException) |
| OnFirstException = false; |
| else |
| OS << ", "; |
| |
| OS << E->getAsString(getPrintingPolicy()); |
| } |
| OS << ")"; |
| break; |
| } |
| |
| case EST_BasicNoexcept: |
| OS << "noexcept"; |
| break; |
| |
| case EST_ComputedNoexcept: |
| OS << "noexcept("; |
| OldProto->getNoexceptExpr()->printPretty(OS, 0, getPrintingPolicy()); |
| OS << ")"; |
| break; |
| |
| default: |
| llvm_unreachable("This spec type is compatible with none."); |
| } |
| OS.flush(); |
| |
| SourceLocation FixItLoc; |
| if (TypeSourceInfo *TSInfo = New->getTypeSourceInfo()) { |
| TypeLoc TL = TSInfo->getTypeLoc().IgnoreParens(); |
| if (FunctionTypeLoc FTLoc = TL.getAs<FunctionTypeLoc>()) |
| FixItLoc = PP.getLocForEndOfToken(FTLoc.getLocalRangeEnd()); |
| } |
| |
| if (FixItLoc.isInvalid()) |
| Diag(New->getLocation(), diag::warn_missing_exception_specification) |
| << New << OS.str(); |
| else { |
| // FIXME: This will get more complicated with C++0x |
| // late-specified return types. |
| Diag(New->getLocation(), diag::warn_missing_exception_specification) |
| << New << OS.str() |
| << FixItHint::CreateInsertion(FixItLoc, " " + OS.str().str()); |
| } |
| |
| if (!Old->getLocation().isInvalid()) |
| Diag(Old->getLocation(), diag::note_previous_declaration); |
| |
| return false; |
| } |
| |
| /// 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) { |
| unsigned DiagID = diag::err_mismatched_exception_spec; |
| if (getLangOpts().MicrosoftExt) |
| DiagID = diag::warn_mismatched_exception_spec; |
| return CheckEquivalentExceptionSpec(PDiag(DiagID), |
| PDiag(diag::note_previous_declaration), |
| Old, OldLoc, New, NewLoc); |
| } |
| |
| /// 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. |
| bool Sema::CheckEquivalentExceptionSpec(const PartialDiagnostic &DiagID, |
| const PartialDiagnostic & NoteID, |
| const FunctionProtoType *Old, |
| SourceLocation OldLoc, |
| const FunctionProtoType *New, |
| SourceLocation NewLoc, |
| bool *MissingExceptionSpecification, |
| bool*MissingEmptyExceptionSpecification, |
| bool AllowNoexceptAllMatchWithNoSpec, |
| bool IsOperatorNew) { |
| // Just completely ignore this under -fno-exceptions. |
| if (!getLangOpts().CXXExceptions) |
| return false; |
| |
| if (MissingExceptionSpecification) |
| *MissingExceptionSpecification = false; |
| |
| if (MissingEmptyExceptionSpecification) |
| *MissingEmptyExceptionSpecification = false; |
| |
| Old = ResolveExceptionSpec(NewLoc, Old); |
| if (!Old) |
| return false; |
| New = 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-specifcation 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"); |
| |
| // Shortcut the case where both have no spec. |
| if (OldEST == EST_None && NewEST == EST_None) |
| return false; |
| |
| FunctionProtoType::NoexceptResult OldNR = Old->getNoexceptSpec(Context); |
| FunctionProtoType::NoexceptResult NewNR = New->getNoexceptSpec(Context); |
| if (OldNR == FunctionProtoType::NR_BadNoexcept || |
| NewNR == FunctionProtoType::NR_BadNoexcept) |
| return false; |
| |
| // Dependent noexcept specifiers are compatible with each other, but nothing |
| // else. |
| // One noexcept is compatible with another if the argument is the same |
| if (OldNR == NewNR && |
| OldNR != FunctionProtoType::NR_NoNoexcept && |
| NewNR != FunctionProtoType::NR_NoNoexcept) |
| return false; |
| if (OldNR != NewNR && |
| OldNR != FunctionProtoType::NR_NoNoexcept && |
| NewNR != FunctionProtoType::NR_NoNoexcept) { |
| Diag(NewLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(OldLoc, NoteID); |
| return true; |
| } |
| |
| // The MS extension throw(...) is compatible with itself. |
| if (OldEST == EST_MSAny && NewEST == EST_MSAny) |
| return false; |
| |
| // It's also compatible with no spec. |
| if ((OldEST == EST_None && NewEST == EST_MSAny) || |
| (OldEST == EST_MSAny && NewEST == EST_None)) |
| return false; |
| |
| // It's also compatible with noexcept(false). |
| if (OldEST == EST_MSAny && NewNR == FunctionProtoType::NR_Throw) |
| return false; |
| if (NewEST == EST_MSAny && OldNR == FunctionProtoType::NR_Throw) |
| return false; |
| |
| // As described above, noexcept(false) matches no spec only for functions. |
| if (AllowNoexceptAllMatchWithNoSpec) { |
| if (OldEST == EST_None && NewNR == FunctionProtoType::NR_Throw) |
| return false; |
| if (NewEST == EST_None && OldNR == FunctionProtoType::NR_Throw) |
| return false; |
| } |
| |
| // Any non-throwing specifications are compatible. |
| bool OldNonThrowing = OldNR == FunctionProtoType::NR_Nothrow || |
| OldEST == EST_DynamicNone; |
| bool NewNonThrowing = NewNR == FunctionProtoType::NR_Nothrow || |
| NewEST == EST_DynamicNone; |
| if (OldNonThrowing && NewNonThrowing) |
| 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 (getLangOpts().CPlusPlus11 && IsOperatorNew) { |
| const FunctionProtoType *WithExceptions = 0; |
| 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? |
| DeclContext* DC = ExRecord->getDeclContext(); |
| DC = DC->getEnclosingNamespaceContext(); |
| if (NamespaceDecl* NS = dyn_cast<NamespaceDecl>(DC)) { |
| IdentifierInfo* NSName = NS->getIdentifier(); |
| DC = DC->getParent(); |
| if (NSName && NSName->getName() == "std" && |
| DC->getEnclosingNamespaceContext()->isTranslationUnit()) { |
| return false; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| // At this point, the only remaining valid case is two matching dynamic |
| // specifications. We return here unless both specifications are dynamic. |
| if (OldEST != EST_Dynamic || NewEST != EST_Dynamic) { |
| if (MissingExceptionSpecification && Old->hasExceptionSpec() && |
| !New->hasExceptionSpec()) { |
| // The old type has an exception specification of some sort, but |
| // the new type does not. |
| *MissingExceptionSpecification = true; |
| |
| if (MissingEmptyExceptionSpecification && OldNonThrowing) { |
| // 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; |
| } |
| |
| Diag(NewLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(OldLoc, NoteID); |
| return true; |
| } |
| |
| assert(OldEST == EST_Dynamic && NewEST == EST_Dynamic && |
| "Exception compatibility logic error: non-dynamic spec slipped through."); |
| |
| 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 (FunctionProtoType::exception_iterator I = Old->exception_begin(), |
| E = Old->exception_end(); I != E; ++I) |
| OldTypes.insert(Context.getCanonicalType(*I).getUnqualifiedType()); |
| |
| for (FunctionProtoType::exception_iterator I = New->exception_begin(), |
| E = New->exception_end(); I != E && Success; ++I) { |
| CanQualType TypePtr = Context.getCanonicalType(*I).getUnqualifiedType(); |
| if(OldTypes.count(TypePtr)) |
| NewTypes.insert(TypePtr); |
| else |
| Success = false; |
| } |
| |
| Success = Success && OldTypes.size() == NewTypes.size(); |
| |
| if (Success) { |
| return false; |
| } |
| Diag(NewLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(OldLoc, NoteID); |
| return true; |
| } |
| |
| /// 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 & NoteID, |
| 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(); |
| |
| // If superset contains everything, we're done. |
| if (SuperEST == EST_None || SuperEST == EST_MSAny) |
| return CheckParamExceptionSpec(NoteID, Superset, SuperLoc, Subset, SubLoc); |
| |
| // 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. |
| // We also shortcut checking if a noexcept expression was bad. |
| |
| FunctionProtoType::NoexceptResult SuperNR =Superset->getNoexceptSpec(Context); |
| if (SuperNR == FunctionProtoType::NR_BadNoexcept || |
| SuperNR == FunctionProtoType::NR_Dependent) |
| return false; |
| |
| // Another case of the superset containing everything. |
| if (SuperNR == FunctionProtoType::NR_Throw) |
| return CheckParamExceptionSpec(NoteID, Superset, SuperLoc, Subset, SubLoc); |
| |
| ExceptionSpecificationType SubEST = Subset->getExceptionSpecType(); |
| |
| assert(!isUnresolvedExceptionSpec(SuperEST) && |
| !isUnresolvedExceptionSpec(SubEST) && |
| "Shouldn't see unknown exception specifications here"); |
| |
| // It does not. If the subset contains everything, we've failed. |
| if (SubEST == EST_None || SubEST == EST_MSAny) { |
| Diag(SubLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(SuperLoc, NoteID); |
| return true; |
| } |
| |
| FunctionProtoType::NoexceptResult SubNR = Subset->getNoexceptSpec(Context); |
| if (SubNR == FunctionProtoType::NR_BadNoexcept || |
| SubNR == FunctionProtoType::NR_Dependent) |
| return false; |
| |
| // Another case of the subset containing everything. |
| if (SubNR == FunctionProtoType::NR_Throw) { |
| Diag(SubLoc, DiagID); |
| if (NoteID.getDiagID() != 0) |
| Diag(SuperLoc, NoteID); |
| return true; |
| } |
| |
| // If the subset contains nothing, we're done. |
| if (SubEST == EST_DynamicNone || SubNR == FunctionProtoType::NR_Nothrow) |
| return CheckParamExceptionSpec(NoteID, Superset, SuperLoc, Subset, SubLoc); |
| |
| // Otherwise, if the superset contains nothing, we've failed. |
| if (SuperEST == EST_DynamicNone || SuperNR == FunctionProtoType::NR_Nothrow) { |
| 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 (FunctionProtoType::exception_iterator SubI = Subset->exception_begin(), |
| SubE = Subset->exception_end(); SubI != SubE; ++SubI) { |
| // Take one type from the subset. |
| QualType CanonicalSubT = Context.getCanonicalType(*SubI); |
| // Unwrap pointers and references so that we can do checks within a class |
| // hierarchy. Don't unwrap member pointers; they don't have hierarchy |
| // conversions on the pointee. |
| bool SubIsPointer = false; |
| if (const ReferenceType *RefTy = CanonicalSubT->getAs<ReferenceType>()) |
| CanonicalSubT = RefTy->getPointeeType(); |
| if (const PointerType *PtrTy = CanonicalSubT->getAs<PointerType>()) { |
| CanonicalSubT = PtrTy->getPointeeType(); |
| SubIsPointer = true; |
| } |
| bool SubIsClass = CanonicalSubT->isRecordType(); |
| CanonicalSubT = CanonicalSubT.getLocalUnqualifiedType(); |
| |
| CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, |
| /*DetectVirtual=*/false); |
| |
| bool Contained = false; |
| // Make sure it's in the superset. |
| for (FunctionProtoType::exception_iterator SuperI = |
| Superset->exception_begin(), SuperE = Superset->exception_end(); |
| SuperI != SuperE; ++SuperI) { |
| QualType CanonicalSuperT = Context.getCanonicalType(*SuperI); |
| // SubT must be SuperT or derived from it, or pointer or reference to |
| // such types. |
| if (const ReferenceType *RefTy = CanonicalSuperT->getAs<ReferenceType>()) |
| CanonicalSuperT = RefTy->getPointeeType(); |
| if (SubIsPointer) { |
| if (const PointerType *PtrTy = CanonicalSuperT->getAs<PointerType>()) |
| CanonicalSuperT = PtrTy->getPointeeType(); |
| else { |
| continue; |
| } |
| } |
| CanonicalSuperT = CanonicalSuperT.getLocalUnqualifiedType(); |
| // If the types are the same, move on to the next type in the subset. |
| if (CanonicalSubT == CanonicalSuperT) { |
| Contained = true; |
| break; |
| } |
| |
| // Otherwise we need to check the inheritance. |
| if (!SubIsClass || !CanonicalSuperT->isRecordType()) |
| continue; |
| |
| Paths.clear(); |
| if (!IsDerivedFrom(CanonicalSubT, CanonicalSuperT, Paths)) |
| continue; |
| |
| if (Paths.isAmbiguous(Context.getCanonicalType(CanonicalSuperT))) |
| continue; |
| |
| // Do this check from a context without privileges. |
| switch (CheckBaseClassAccess(SourceLocation(), |
| CanonicalSuperT, CanonicalSubT, |
| Paths.front(), |
| /*Diagnostic*/ 0, |
| /*ForceCheck*/ true, |
| /*ForceUnprivileged*/ true)) { |
| case AR_accessible: break; |
| case AR_inaccessible: continue; |
| case AR_dependent: |
| llvm_unreachable("access check dependent for unprivileged context"); |
| case AR_delayed: |
| llvm_unreachable("access check delayed in non-declaration"); |
| } |
| |
| 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(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 & NoteID, |
| const FunctionProtoType *Target, SourceLocation TargetLoc, |
| const FunctionProtoType *Source, SourceLocation SourceLoc) |
| { |
| if (CheckSpecForTypesEquivalent(*this, |
| PDiag(diag::err_deep_exception_specs_differ) << 0, |
| PDiag(), |
| Target->getResultType(), TargetLoc, |
| Source->getResultType(), SourceLoc)) |
| return true; |
| |
| // We shouldn't even be testing this unless the arguments are otherwise |
| // compatible. |
| assert(Target->getNumArgs() == Source->getNumArgs() && |
| "Functions have different argument counts."); |
| for (unsigned i = 0, E = Target->getNumArgs(); i != E; ++i) { |
| if (CheckSpecForTypesEquivalent(*this, |
| PDiag(diag::err_deep_exception_specs_differ) << 1, |
| PDiag(), |
| Target->getArgType(i), TargetLoc, |
| Source->getArgType(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) |
| return false; |
| |
| // SourceType must be a function or function pointer. |
| const FunctionProtoType *FromFunc = GetUnderlyingFunction(From->getType()); |
| if (!FromFunc) |
| return false; |
| |
| // 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. |
| return CheckExceptionSpecSubset(PDiag(diag::err_incompatible_exception_specs), |
| PDiag(), ToFunc, |
| From->getSourceRange().getBegin(), |
| FromFunc, SourceLocation()); |
| } |
| |
| bool Sema::CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New, |
| const CXXMethodDecl *Old) { |
| if (getLangOpts().CPlusPlus11 && isa<CXXDestructorDecl>(New)) { |
| // Don't check uninstantiated template destructors at all. We can only |
| // synthesize correct specs after the template is instantiated. |
| if (New->getParent()->isDependentType()) |
| return false; |
| if (New->getParent()->isBeingDefined()) { |
| // The destructor might be updated once the definition is finished. So |
| // remember it and check later. |
| DelayedDestructorExceptionSpecChecks.push_back(std::make_pair( |
| cast<CXXDestructorDecl>(New), cast<CXXDestructorDecl>(Old))); |
| return false; |
| } |
| } |
| unsigned DiagID = diag::err_override_exception_spec; |
| if (getLangOpts().MicrosoftExt) |
| DiagID = diag::warn_override_exception_spec; |
| return CheckExceptionSpecSubset(PDiag(DiagID), |
| PDiag(diag::note_overridden_virtual_function), |
| Old->getType()->getAs<FunctionProtoType>(), |
| Old->getLocation(), |
| New->getType()->getAs<FunctionProtoType>(), |
| New->getLocation()); |
| } |
| |
| static CanThrowResult canSubExprsThrow(Sema &S, const Expr *CE) { |
| Expr *E = const_cast<Expr*>(CE); |
| CanThrowResult R = CT_Cannot; |
| for (Expr::child_range I = E->children(); I && R != CT_Can; ++I) |
| R = mergeCanThrow(R, S.canThrow(cast<Expr>(*I))); |
| return R; |
| } |
| |
| static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D) { |
| assert(D && "Expected decl"); |
| |
| // See if we can get a function type from the decl somehow. |
| const ValueDecl *VD = dyn_cast<ValueDecl>(D); |
| if (!VD) // If we have no clue what we're calling, assume the worst. |
| return CT_Can; |
| |
| // As an extension, we assume that __attribute__((nothrow)) functions don't |
| // throw. |
| if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>()) |
| return CT_Cannot; |
| |
| QualType T = VD->getType(); |
| 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; |
| |
| FT = S.ResolveExceptionSpec(E->getLocStart(), FT); |
| if (!FT) |
| return CT_Can; |
| |
| return FT->isNothrow(S.Context) ? CT_Cannot : CT_Can; |
| } |
| |
| 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 Expr *E) { |
| // C++ [expr.unary.noexcept]p3: |
| // [Can throw] if in a potentially-evaluated context the expression would |
| // contain: |
| switch (E->getStmtClass()) { |
| 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 |
| CanThrowResult CT = canDynamicCastThrow(cast<CXXDynamicCastExpr>(E)); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| 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>(E)); |
| |
| // - 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>(E); |
| CanThrowResult CT; |
| if (E->isTypeDependent()) |
| CT = CT_Dependent; |
| else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens())) |
| CT = CT_Cannot; |
| else if (CE->getCalleeDecl()) |
| CT = canCalleeThrow(*this, E, CE->getCalleeDecl()); |
| else |
| CT = CT_Can; |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| case Expr::CXXConstructExprClass: |
| case Expr::CXXTemporaryObjectExprClass: { |
| CanThrowResult CT = canCalleeThrow(*this, E, |
| cast<CXXConstructExpr>(E)->getConstructor()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| case Expr::LambdaExprClass: { |
| const LambdaExpr *Lambda = cast<LambdaExpr>(E); |
| CanThrowResult CT = CT_Cannot; |
| for (LambdaExpr::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: { |
| CanThrowResult CT; |
| if (E->isTypeDependent()) |
| CT = CT_Dependent; |
| else |
| CT = canCalleeThrow(*this, E, cast<CXXNewExpr>(E)->getOperatorNew()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| case Expr::CXXDeleteExprClass: { |
| CanThrowResult CT; |
| QualType DTy = cast<CXXDeleteExpr>(E)->getDestroyedType(); |
| if (DTy.isNull() || DTy->isDependentType()) { |
| CT = CT_Dependent; |
| } else { |
| CT = canCalleeThrow(*this, E, |
| cast<CXXDeleteExpr>(E)->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, E, DD)); |
| } |
| if (CT == CT_Can) |
| return CT; |
| } |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| case Expr::CXXBindTemporaryExprClass: { |
| // The bound temporary has to be destroyed again, which might throw. |
| CanThrowResult CT = canCalleeThrow(*this, E, |
| cast<CXXBindTemporaryExpr>(E)->getTemporary()->getDestructor()); |
| if (CT == CT_Can) |
| return CT; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| // 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::ConditionalOperatorClass: |
| case Expr::CompoundLiteralExprClass: |
| case Expr::CXXConstCastExprClass: |
| case Expr::CXXReinterpretCastExprClass: |
| case Expr::CXXStdInitializerListExprClass: |
| case Expr::DesignatedInitExprClass: |
| case Expr::ExprWithCleanupsClass: |
| case Expr::ExtVectorElementExprClass: |
| case Expr::InitListExprClass: |
| case Expr::MemberExprClass: |
| case Expr::ObjCIsaExprClass: |
| case Expr::ObjCIvarRefExprClass: |
| case Expr::ParenExprClass: |
| case Expr::ParenListExprClass: |
| case Expr::ShuffleVectorExprClass: |
| case Expr::ConvertVectorExprClass: |
| case Expr::VAArgExprClass: |
| return canSubExprsThrow(*this, E); |
| |
| // Some might be dependent for other reasons. |
| case Expr::ArraySubscriptExprClass: |
| case Expr::BinaryOperatorClass: |
| case Expr::CompoundAssignOperatorClass: |
| case Expr::CStyleCastExprClass: |
| case Expr::CXXStaticCastExprClass: |
| case Expr::CXXFunctionalCastExprClass: |
| case Expr::ImplicitCastExprClass: |
| case Expr::MaterializeTemporaryExprClass: |
| case Expr::UnaryOperatorClass: { |
| CanThrowResult CT = E->isTypeDependent() ? CT_Dependent : CT_Cannot; |
| return mergeCanThrow(CT, canSubExprsThrow(*this, E)); |
| } |
| |
| // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms. |
| case Expr::StmtExprClass: |
| return CT_Can; |
| |
| case Expr::CXXDefaultArgExprClass: |
| return canThrow(cast<CXXDefaultArgExpr>(E)->getExpr()); |
| |
| case Expr::CXXDefaultInitExprClass: |
| return canThrow(cast<CXXDefaultInitExpr>(E)->getExpr()); |
| |
| case Expr::ChooseExprClass: |
| if (E->isTypeDependent() || E->isValueDependent()) |
| return CT_Dependent; |
| return canThrow(cast<ChooseExpr>(E)->getChosenSubExpr()); |
| |
| case Expr::GenericSelectionExprClass: |
| if (cast<GenericSelectionExpr>(E)->isResultDependent()) |
| return CT_Dependent; |
| return canThrow(cast<GenericSelectionExpr>(E)->getResultExpr()); |
| |
| // Some expressions are always dependent. |
| case Expr::CXXDependentScopeMemberExprClass: |
| case Expr::CXXUnresolvedConstructExprClass: |
| case Expr::DependentScopeDeclRefExprClass: |
| 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::OffsetOfExprClass: |
| case Expr::PackExpansionExprClass: |
| case Expr::PseudoObjectExprClass: |
| case Expr::SubstNonTypeTemplateParmExprClass: |
| case Expr::SubstNonTypeTemplateParmPackExprClass: |
| case Expr::FunctionParmPackExprClass: |
| case Expr::UnaryExprOrTypeTraitExprClass: |
| case Expr::UnresolvedLookupExprClass: |
| case Expr::UnresolvedMemberExprClass: |
| // FIXME: Can any of the above throw? If so, when? |
| return CT_Cannot; |
| |
| case Expr::AddrLabelExprClass: |
| case Expr::ArrayTypeTraitExprClass: |
| case Expr::AtomicExprClass: |
| case Expr::BinaryTypeTraitExprClass: |
| 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::ObjCEncodeExprClass: |
| case Expr::ObjCStringLiteralClass: |
| case Expr::ObjCBoolLiteralExprClass: |
| case Expr::OpaqueValueExprClass: |
| case Expr::PredefinedExprClass: |
| case Expr::SizeOfPackExprClass: |
| case Expr::StringLiteralClass: |
| case Expr::UnaryTypeTraitExprClass: |
| // These expressions can never throw. |
| return CT_Cannot; |
| |
| case Expr::MSPropertyRefExprClass: |
| llvm_unreachable("Invalid class for expression"); |
| |
| #define STMT(CLASS, PARENT) case Expr::CLASS##Class: |
| #define STMT_RANGE(Base, First, Last) |
| #define LAST_STMT_RANGE(BASE, FIRST, LAST) |
| #define EXPR(CLASS, PARENT) |
| #define ABSTRACT_STMT(STMT) |
| #include "clang/AST/StmtNodes.inc" |
| case Expr::NoStmtClass: |
| llvm_unreachable("Invalid class for expression"); |
| } |
| llvm_unreachable("Bogus StmtClass"); |
| } |
| |
| } // end namespace clang |