| //===--- OwningMemoryCheck.cpp - clang-tidy--------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "OwningMemoryCheck.h" |
| #include "../utils/Matchers.h" |
| #include "../utils/OptionsUtils.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| #include <string> |
| #include <vector> |
| |
| using namespace clang::ast_matchers; |
| using namespace clang::ast_matchers::internal; |
| |
| namespace clang { |
| namespace tidy { |
| namespace cppcoreguidelines { |
| |
| // FIXME: Copied from 'NoMallocCheck.cpp'. Has to be refactored into 'util' or |
| // something like that. |
| namespace { |
| Matcher<FunctionDecl> hasAnyListedName(const std::string &FunctionNames) { |
| const std::vector<std::string> NameList = |
| utils::options::parseStringList(FunctionNames); |
| return hasAnyName(std::vector<StringRef>(NameList.begin(), NameList.end())); |
| } |
| } // namespace |
| |
| void OwningMemoryCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { |
| Options.store(Opts, "LegacyResourceProducers", LegacyResourceProducers); |
| Options.store(Opts, "LegacyResourceConsumers", LegacyResourceConsumers); |
| } |
| |
| /// Match common cases, where the owner semantic is relevant, like function |
| /// calls, delete expressions and others. |
| void OwningMemoryCheck::registerMatchers(MatchFinder *Finder) { |
| const auto OwnerDecl = typeAliasTemplateDecl(hasName("::gsl::owner")); |
| const auto IsOwnerType = hasType(OwnerDecl); |
| |
| const auto LegacyCreatorFunctions = hasAnyListedName(LegacyResourceProducers); |
| const auto LegacyConsumerFunctions = |
| hasAnyListedName(LegacyResourceConsumers); |
| |
| // Legacy functions that are use for resource management but cannot be |
| // updated to use `gsl::owner<>`, like standard C memory management. |
| const auto CreatesLegacyOwner = |
| callExpr(callee(functionDecl(LegacyCreatorFunctions))); |
| // C-style functions like `::malloc()` sometimes create owners as void* |
| // which is expected to be cast to the correct type in C++. This case |
| // must be caught explicitly. |
| const auto LegacyOwnerCast = |
| castExpr(hasSourceExpression(CreatesLegacyOwner)); |
| // Functions that do manual resource management but cannot be updated to use |
| // owner. Best example is `::free()`. |
| const auto LegacyOwnerConsumers = functionDecl(LegacyConsumerFunctions); |
| |
| const auto CreatesOwner = |
| anyOf(cxxNewExpr(), |
| callExpr(callee( |
| functionDecl(returns(qualType(hasDeclaration(OwnerDecl)))))), |
| CreatesLegacyOwner, LegacyOwnerCast); |
| |
| const auto ConsideredOwner = eachOf(IsOwnerType, CreatesOwner); |
| |
| // Find delete expressions that delete non-owners. |
| Finder->addMatcher( |
| traverse(TK_AsIs, |
| cxxDeleteExpr(hasDescendant(declRefExpr(unless(ConsideredOwner)) |
| .bind("deleted_variable"))) |
| .bind("delete_expr")), |
| this); |
| |
| // Ignoring the implicit casts is vital because the legacy owners do not work |
| // with the 'owner<>' annotation and therefore always implicitly cast to the |
| // legacy type (even 'void *'). |
| // |
| // Furthermore, legacy owner functions are assumed to use raw pointers for |
| // resources. This check assumes that all pointer arguments of a legacy |
| // functions shall be 'gsl::owner<>'. |
| Finder->addMatcher( |
| traverse(TK_AsIs, callExpr(callee(LegacyOwnerConsumers), |
| hasAnyArgument(expr( |
| unless(ignoringImpCasts(ConsideredOwner)), |
| hasType(pointerType())))) |
| .bind("legacy_consumer")), |
| this); |
| |
| // Matching assignment to owners, with the rhs not being an owner nor creating |
| // one. |
| Finder->addMatcher( |
| traverse(TK_AsIs, |
| binaryOperator(isAssignmentOperator(), hasLHS(IsOwnerType), |
| hasRHS(unless(ConsideredOwner))) |
| .bind("owner_assignment")), |
| this); |
| |
| // Matching initialization of owners with non-owners, nor creating owners. |
| Finder->addMatcher( |
| traverse(TK_AsIs, |
| namedDecl( |
| varDecl(hasInitializer(unless(ConsideredOwner)), IsOwnerType) |
| .bind("owner_initialization"))), |
| this); |
| |
| const auto HasConstructorInitializerForOwner = |
| has(cxxConstructorDecl(forEachConstructorInitializer( |
| cxxCtorInitializer( |
| isMemberInitializer(), forField(IsOwnerType), |
| withInitializer( |
| // Avoid templatesdeclaration with |
| // excluding parenListExpr. |
| allOf(unless(ConsideredOwner), unless(parenListExpr())))) |
| .bind("owner_member_initializer")))); |
| |
| // Match class member initialization that expects owners, but does not get |
| // them. |
| Finder->addMatcher( |
| traverse(TK_AsIs, cxxRecordDecl(HasConstructorInitializerForOwner)), |
| this); |
| |
| // Matching on assignment operations where the RHS is a newly created owner, |
| // but the LHS is not an owner. |
| Finder->addMatcher(binaryOperator(isAssignmentOperator(), |
| hasLHS(unless(IsOwnerType)), |
| hasRHS(CreatesOwner)) |
| .bind("bad_owner_creation_assignment"), |
| this); |
| |
| // Matching on initialization operations where the initial value is a newly |
| // created owner, but the LHS is not an owner. |
| Finder->addMatcher( |
| traverse(TK_AsIs, namedDecl(varDecl(allOf(hasInitializer(CreatesOwner), |
| unless(IsOwnerType))) |
| .bind("bad_owner_creation_variable"))), |
| this); |
| |
| // Match on all function calls that expect owners as arguments, but didn't |
| // get them. |
| Finder->addMatcher( |
| callExpr(forEachArgumentWithParam( |
| expr(unless(ConsideredOwner)).bind("expected_owner_argument"), |
| parmVarDecl(IsOwnerType))), |
| this); |
| |
| // Matching for function calls where one argument is a created owner, but the |
| // parameter type is not an owner. |
| Finder->addMatcher(callExpr(forEachArgumentWithParam( |
| expr(CreatesOwner).bind("bad_owner_creation_argument"), |
| parmVarDecl(unless(IsOwnerType)) |
| .bind("bad_owner_creation_parameter"))), |
| this); |
| |
| // Matching on functions, that return an owner/resource, but don't declare |
| // their return type as owner. |
| Finder->addMatcher( |
| functionDecl(hasDescendant(returnStmt(hasReturnValue(ConsideredOwner)) |
| .bind("bad_owner_return")), |
| unless(returns(qualType(hasDeclaration(OwnerDecl))))) |
| .bind("function_decl"), |
| this); |
| |
| // Match on classes that have an owner as member, but don't declare a |
| // destructor to properly release the owner. |
| Finder->addMatcher( |
| cxxRecordDecl( |
| has(fieldDecl(IsOwnerType).bind("undestructed_owner_member")), |
| anyOf(unless(has(cxxDestructorDecl())), |
| has(cxxDestructorDecl(anyOf(isDefaulted(), isDeleted()))))) |
| .bind("non_destructor_class"), |
| this); |
| } |
| |
| void OwningMemoryCheck::check(const MatchFinder::MatchResult &Result) { |
| const auto &Nodes = Result.Nodes; |
| |
| bool CheckExecuted = false; |
| CheckExecuted |= handleDeletion(Nodes); |
| CheckExecuted |= handleLegacyConsumers(Nodes); |
| CheckExecuted |= handleExpectedOwner(Nodes); |
| CheckExecuted |= handleAssignmentAndInit(Nodes); |
| CheckExecuted |= handleAssignmentFromNewOwner(Nodes); |
| CheckExecuted |= handleReturnValues(Nodes); |
| CheckExecuted |= handleOwnerMembers(Nodes); |
| |
| (void)CheckExecuted; |
| assert(CheckExecuted && |
| "None of the subroutines executed, logic error in matcher!"); |
| } |
| |
| bool OwningMemoryCheck::handleDeletion(const BoundNodes &Nodes) { |
| // Result of delete matchers. |
| const auto *DeleteStmt = Nodes.getNodeAs<CXXDeleteExpr>("delete_expr"); |
| const auto *DeletedVariable = |
| Nodes.getNodeAs<DeclRefExpr>("deleted_variable"); |
| |
| // Deletion of non-owners, with `delete variable;` |
| if (DeleteStmt) { |
| diag(DeleteStmt->getBeginLoc(), |
| "deleting a pointer through a type that is " |
| "not marked 'gsl::owner<>'; consider using a " |
| "smart pointer instead") |
| << DeletedVariable->getSourceRange(); |
| |
| // FIXME: The declaration of the variable that was deleted can be |
| // rewritten. |
| const ValueDecl *Decl = DeletedVariable->getDecl(); |
| diag(Decl->getBeginLoc(), "variable declared here", DiagnosticIDs::Note) |
| << Decl->getSourceRange(); |
| |
| return true; |
| } |
| return false; |
| } |
| |
| bool OwningMemoryCheck::handleLegacyConsumers(const BoundNodes &Nodes) { |
| // Result of matching for legacy consumer-functions like `::free()`. |
| const auto *LegacyConsumer = Nodes.getNodeAs<CallExpr>("legacy_consumer"); |
| |
| // FIXME: `freopen` should be handled separately because it takes the filename |
| // as a pointer, which should not be an owner. The argument that is an owner |
| // is known and the false positive coming from the filename can be avoided. |
| if (LegacyConsumer) { |
| diag(LegacyConsumer->getBeginLoc(), |
| "calling legacy resource function without passing a 'gsl::owner<>'") |
| << LegacyConsumer->getSourceRange(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool OwningMemoryCheck::handleExpectedOwner(const BoundNodes &Nodes) { |
| // Result of function call matchers. |
| const auto *ExpectedOwner = Nodes.getNodeAs<Expr>("expected_owner_argument"); |
| |
| // Expected function argument to be owner. |
| if (ExpectedOwner) { |
| diag(ExpectedOwner->getBeginLoc(), |
| "expected argument of type 'gsl::owner<>'; got %0") |
| << ExpectedOwner->getType() << ExpectedOwner->getSourceRange(); |
| return true; |
| } |
| return false; |
| } |
| |
| /// Assignment and initialization of owner variables. |
| bool OwningMemoryCheck::handleAssignmentAndInit(const BoundNodes &Nodes) { |
| const auto *OwnerAssignment = |
| Nodes.getNodeAs<BinaryOperator>("owner_assignment"); |
| const auto *OwnerInitialization = |
| Nodes.getNodeAs<VarDecl>("owner_initialization"); |
| const auto *OwnerInitializer = |
| Nodes.getNodeAs<CXXCtorInitializer>("owner_member_initializer"); |
| |
| // Assignments to owners. |
| if (OwnerAssignment) { |
| diag(OwnerAssignment->getBeginLoc(), |
| "expected assignment source to be of type 'gsl::owner<>'; got %0") |
| << OwnerAssignment->getRHS()->getType() |
| << OwnerAssignment->getSourceRange(); |
| return true; |
| } |
| |
| // Initialization of owners. |
| if (OwnerInitialization) { |
| diag(OwnerInitialization->getBeginLoc(), |
| "expected initialization with value of type 'gsl::owner<>'; got %0") |
| << OwnerInitialization->getAnyInitializer()->getType() |
| << OwnerInitialization->getSourceRange(); |
| return true; |
| } |
| |
| // Initializer of class constructors that initialize owners. |
| if (OwnerInitializer) { |
| diag(OwnerInitializer->getSourceLocation(), |
| "expected initialization of owner member variable with value of type " |
| "'gsl::owner<>'; got %0") |
| // FIXME: the expression from getInit has type 'void', but the type |
| // of the supplied argument would be of interest. |
| << OwnerInitializer->getInit()->getType() |
| << OwnerInitializer->getSourceRange(); |
| return true; |
| } |
| return false; |
| } |
| |
| /// Problematic assignment and initializations, since the assigned value is a |
| /// newly created owner. |
| bool OwningMemoryCheck::handleAssignmentFromNewOwner(const BoundNodes &Nodes) { |
| const auto *BadOwnerAssignment = |
| Nodes.getNodeAs<BinaryOperator>("bad_owner_creation_assignment"); |
| const auto *BadOwnerInitialization = |
| Nodes.getNodeAs<VarDecl>("bad_owner_creation_variable"); |
| |
| const auto *BadOwnerArgument = |
| Nodes.getNodeAs<Expr>("bad_owner_creation_argument"); |
| const auto *BadOwnerParameter = |
| Nodes.getNodeAs<ParmVarDecl>("bad_owner_creation_parameter"); |
| |
| // Bad assignments to non-owners, where the RHS is a newly created owner. |
| if (BadOwnerAssignment) { |
| diag(BadOwnerAssignment->getBeginLoc(), |
| "assigning newly created 'gsl::owner<>' to non-owner %0") |
| << BadOwnerAssignment->getLHS()->getType() |
| << BadOwnerAssignment->getSourceRange(); |
| return true; |
| } |
| |
| // Bad initialization of non-owners, where the RHS is a newly created owner. |
| if (BadOwnerInitialization) { |
| diag(BadOwnerInitialization->getBeginLoc(), |
| "initializing non-owner %0 with a newly created 'gsl::owner<>'") |
| << BadOwnerInitialization->getType() |
| << BadOwnerInitialization->getSourceRange(); |
| |
| // FIXME: FixitHint to rewrite the type of the initialized variable |
| // as 'gsl::owner<OriginalType>' |
| return true; |
| } |
| |
| // Function call, where one arguments is a newly created owner, but the |
| // parameter type is not. |
| if (BadOwnerArgument) { |
| assert(BadOwnerParameter && |
| "parameter for the problematic argument not found"); |
| diag(BadOwnerArgument->getBeginLoc(), "initializing non-owner argument of " |
| "type %0 with a newly created " |
| "'gsl::owner<>'") |
| << BadOwnerParameter->getType() << BadOwnerArgument->getSourceRange(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool OwningMemoryCheck::handleReturnValues(const BoundNodes &Nodes) { |
| // Function return statements, that are owners/resources, but the function |
| // declaration does not declare its return value as owner. |
| const auto *BadReturnType = Nodes.getNodeAs<ReturnStmt>("bad_owner_return"); |
| const auto *Function = Nodes.getNodeAs<FunctionDecl>("function_decl"); |
| |
| // Function return values, that should be owners but aren't. |
| if (BadReturnType) { |
| // The returned value is a resource or variable that was not annotated with |
| // owner<> and the function return type is not owner<>. |
| diag(BadReturnType->getBeginLoc(), |
| "returning a newly created resource of " |
| "type %0 or 'gsl::owner<>' from a " |
| "function whose return type is not 'gsl::owner<>'") |
| << Function->getReturnType() << BadReturnType->getSourceRange(); |
| |
| // FIXME: Rewrite the return type as 'gsl::owner<OriginalType>' |
| return true; |
| } |
| return false; |
| } |
| |
| bool OwningMemoryCheck::handleOwnerMembers(const BoundNodes &Nodes) { |
| // Classes, that have owners as member, but do not declare destructors |
| // accordingly. |
| const auto *BadClass = Nodes.getNodeAs<CXXRecordDecl>("non_destructor_class"); |
| |
| // Classes, that contains owners, but do not declare destructors. |
| if (BadClass) { |
| const auto *DeclaredOwnerMember = |
| Nodes.getNodeAs<FieldDecl>("undestructed_owner_member"); |
| assert(DeclaredOwnerMember && |
| "match on class with bad destructor but without a declared owner"); |
| |
| diag(DeclaredOwnerMember->getBeginLoc(), |
| "member variable of type 'gsl::owner<>' requires the class %0 to " |
| "implement a destructor to release the owned resource") |
| << BadClass; |
| return true; |
| } |
| return false; |
| } |
| |
| } // namespace cppcoreguidelines |
| } // namespace tidy |
| } // namespace clang |
