diff options
Diffstat (limited to 'absl/base/internal/exception_safety_testing.h')
| -rw-r--r-- | absl/base/internal/exception_safety_testing.h | 242 |
1 files changed, 110 insertions, 132 deletions
diff --git a/absl/base/internal/exception_safety_testing.h b/absl/base/internal/exception_safety_testing.h index 5665a1b67db2..429f5c2f1bb9 100644 --- a/absl/base/internal/exception_safety_testing.h +++ b/absl/base/internal/exception_safety_testing.h @@ -190,70 +190,6 @@ class TrackedObject { ~TrackedObject() noexcept { ConstructorTracker::ObjectDestructed(this); } }; - -template <typename Factory, typename Operation, typename Contract> -absl::optional<testing::AssertionResult> TestSingleContractAtCountdownImpl( - const Factory& factory, const Operation& operation, int count, - const Contract& contract) { - auto t_ptr = factory(); - absl::optional<testing::AssertionResult> current_res; - SetCountdown(count); - try { - operation(t_ptr.get()); - } catch (const exceptions_internal::TestException& e) { - current_res.emplace(contract(t_ptr.get())); - if (!current_res.value()) { - *current_res << e.what() << " failed contract check"; - } - } - UnsetCountdown(); - return current_res; -} - -template <typename Factory, typename Operation> -absl::optional<testing::AssertionResult> TestSingleContractAtCountdownImpl( - const Factory& factory, const Operation& operation, int count, - StrongGuaranteeTagType) { - using TPtr = typename decltype(factory())::pointer; - auto t_is_strong = [&](TPtr t) { return *t == *factory(); }; - return TestSingleContractAtCountdownImpl(factory, operation, count, - t_is_strong); -} - -template <typename Factory, typename Operation, typename Contract> -int TestSingleContractAtCountdown( - const Factory& factory, const Operation& operation, int count, - const Contract& contract, - absl::optional<testing::AssertionResult>* reduced_res) { - // If reduced_res is empty, it means the current call to - // TestSingleContractAtCountdown(...) is the first test being run so we do - // want to run it. Alternatively, if it's not empty (meaning a previous test - // has run) we want to check if it passed. If the previous test did pass, we - // want to contine running tests so we do want to run the current one. If it - // failed, we want to short circuit so as not to overwrite the AssertionResult - // output. If that's the case, we do not run the current test and instead we - // simply return. - if (!reduced_res->has_value() || reduced_res->value()) { - *reduced_res = - TestSingleContractAtCountdownImpl(factory, operation, count, contract); - } - return 0; -} - -template <typename Factory, typename Operation, typename... Contracts> -inline absl::optional<testing::AssertionResult> TestAllContractsAtCountdown( - const Factory& factory, const Operation& operation, int count, - const Contracts&... contracts) { - absl::optional<testing::AssertionResult> reduced_res; - - // Run each checker, short circuiting after the first failure - int dummy[] = { - 0, (TestSingleContractAtCountdown(factory, operation, count, contracts, - &reduced_res))...}; - static_cast<void>(dummy); - return reduced_res; -} - } // namespace exceptions_internal extern exceptions_internal::NoThrowTag nothrow_ctor; @@ -871,7 +807,7 @@ testing::AssertionResult TestNothrowOp(const Operation& operation) { namespace exceptions_internal { -// Dummy struct for ExceptionSafetyTester<> partial state. +// Dummy struct for ExceptionSafetyTestBuilder<> partial state. struct UninitializedT {}; template <typename T> @@ -893,20 +829,97 @@ using EnableIfTestable = typename absl::enable_if_t< template <typename Factory = UninitializedT, typename Operation = UninitializedT, typename... Contracts> -class ExceptionSafetyTester; +class ExceptionSafetyTestBuilder; } // namespace exceptions_internal -exceptions_internal::ExceptionSafetyTester<> MakeExceptionSafetyTester(); +/* + * Constructs an empty ExceptionSafetyTestBuilder. All + * ExceptionSafetyTestBuilder objects are immutable and all With[thing] mutation + * methods return new instances of ExceptionSafetyTestBuilder. + * + * In order to test a T for exception safety, a factory for that T, a testable + * operation, and at least one contract callback returning an assertion + * result must be applied using the respective methods. + */ +exceptions_internal::ExceptionSafetyTestBuilder<> MakeExceptionSafetyTester(); namespace exceptions_internal { +template <typename T> +struct IsUniquePtr : std::false_type {}; + +template <typename T, typename D> +struct IsUniquePtr<std::unique_ptr<T, D>> : std::true_type {}; + +template <typename Factory> +struct FactoryPtrTypeHelper { + using type = decltype(std::declval<const Factory&>()()); + + static_assert(IsUniquePtr<type>::value, "Factories must return a unique_ptr"); +}; + +template <typename Factory> +using FactoryPtrType = typename FactoryPtrTypeHelper<Factory>::type; + +template <typename Factory> +using FactoryElementType = typename FactoryPtrType<Factory>::element_type; + +template <typename T> +class ExceptionSafetyTest { + using Factory = std::function<std::unique_ptr<T>()>; + using Operation = std::function<void(T*)>; + using Contract = std::function<AssertionResult(T*)>; + + public: + template <typename... Contracts> + explicit ExceptionSafetyTest(const Factory& f, const Operation& op, + const Contracts&... contracts) + : factory_(f), operation_(op), contracts_{WrapContract(contracts)...} {} + + AssertionResult Test() const { + for (int count = 0;; ++count) { + exceptions_internal::ConstructorTracker ct(count); + + for (const auto& contract : contracts_) { + auto t_ptr = factory_(); + try { + SetCountdown(count); + operation_(t_ptr.get()); + // Unset for the case that the operation throws no exceptions, which + // would leave the countdown set and break the *next* exception safety + // test after this one. + UnsetCountdown(); + return AssertionSuccess(); + } catch (const exceptions_internal::TestException& e) { + if (!contract(t_ptr.get())) { + return AssertionFailure() << e.what() << " failed contract check"; + } + } + } + } + } + + private: + template <typename ContractFn> + Contract WrapContract(const ContractFn& contract) { + return [contract](T* t_ptr) { return AssertionResult(contract(t_ptr)); }; + } + + Contract WrapContract(StrongGuaranteeTagType) { + return [this](T* t_ptr) { return AssertionResult(*factory_() == *t_ptr); }; + } + + Factory factory_; + Operation operation_; + std::vector<Contract> contracts_; +}; /* * Builds a tester object that tests if performing a operation on a T follows * exception safety guarantees. Verification is done via contract assertion * callbacks applied to T instances post-throw. * - * Template parameters for ExceptionSafetyTester: + * Template parameters for ExceptionSafetyTestBuilder: * * - Factory: The factory object (passed in via tester.WithFactory(...) or * tester.WithInitialValue(...)) must be invocable with the signature @@ -933,13 +946,13 @@ namespace exceptions_internal { * please. */ template <typename Factory, typename Operation, typename... Contracts> -class ExceptionSafetyTester { +class ExceptionSafetyTestBuilder { public: /* - * Returns a new ExceptionSafetyTester with an included T factory based on the - * provided T instance. The existing factory will not be included in the newly - * created tester instance. The created factory returns a new T instance by - * copy-constructing the provided const T& t. + * Returns a new ExceptionSafetyTestBuilder with an included T factory based + * on the provided T instance. The existing factory will not be included in + * the newly created tester instance. The created factory returns a new T + * instance by copy-constructing the provided const T& t. * * Preconditions for tester.WithInitialValue(const T& t): * @@ -948,41 +961,41 @@ class ExceptionSafetyTester { * tester.WithFactory(...). */ template <typename T> - ExceptionSafetyTester<DefaultFactory<T>, Operation, Contracts...> + ExceptionSafetyTestBuilder<DefaultFactory<T>, Operation, Contracts...> WithInitialValue(const T& t) const { return WithFactory(DefaultFactory<T>(t)); } /* - * Returns a new ExceptionSafetyTester with the provided T factory included. - * The existing factory will not be included in the newly-created tester - * instance. This method is intended for use with types lacking a copy + * Returns a new ExceptionSafetyTestBuilder with the provided T factory + * included. The existing factory will not be included in the newly-created + * tester instance. This method is intended for use with types lacking a copy * constructor. Types that can be copy-constructed should instead use the * method tester.WithInitialValue(...). */ template <typename NewFactory> - ExceptionSafetyTester<absl::decay_t<NewFactory>, Operation, Contracts...> + ExceptionSafetyTestBuilder<absl::decay_t<NewFactory>, Operation, Contracts...> WithFactory(const NewFactory& new_factory) const { return {new_factory, operation_, contracts_}; } /* - * Returns a new ExceptionSafetyTester with the provided testable operation - * included. The existing operation will not be included in the newly created - * tester. + * Returns a new ExceptionSafetyTestBuilder with the provided testable + * operation included. The existing operation will not be included in the + * newly created tester. */ template <typename NewOperation> - ExceptionSafetyTester<Factory, absl::decay_t<NewOperation>, Contracts...> + ExceptionSafetyTestBuilder<Factory, absl::decay_t<NewOperation>, Contracts...> WithOperation(const NewOperation& new_operation) const { return {factory_, new_operation, contracts_}; } /* - * Returns a new ExceptionSafetyTester with the provided MoreContracts... + * Returns a new ExceptionSafetyTestBuilder with the provided MoreContracts... * combined with the Contracts... that were already included in the instance * on which the method was called. Contracts... cannot be removed or replaced - * once added to an ExceptionSafetyTester instance. A fresh object must be - * created in order to get an empty Contracts... list. + * once added to an ExceptionSafetyTestBuilder instance. A fresh object must + * be created in order to get an empty Contracts... list. * * In addition to passing in custom contract assertion callbacks, this method * accepts `testing::strong_guarantee` as an argument which checks T instances @@ -991,8 +1004,8 @@ class ExceptionSafetyTester { * properly rolled back. */ template <typename... MoreContracts> - ExceptionSafetyTester<Factory, Operation, Contracts..., - absl::decay_t<MoreContracts>...> + ExceptionSafetyTestBuilder<Factory, Operation, Contracts..., + absl::decay_t<MoreContracts>...> WithContracts(const MoreContracts&... more_contracts) const { return { factory_, operation_, @@ -1039,48 +1052,27 @@ class ExceptionSafetyTester { typename LazyOperation = Operation, typename = EnableIfTestable<sizeof...(Contracts), Factory, LazyOperation>> testing::AssertionResult Test() const { - return TestImpl(operation_, absl::index_sequence_for<Contracts...>()); + return Test(operation_); } private: template <typename, typename, typename...> - friend class ExceptionSafetyTester; + friend class ExceptionSafetyTestBuilder; - friend ExceptionSafetyTester<> testing::MakeExceptionSafetyTester(); + friend ExceptionSafetyTestBuilder<> testing::MakeExceptionSafetyTester(); - ExceptionSafetyTester() {} + ExceptionSafetyTestBuilder() {} - ExceptionSafetyTester(const Factory& f, const Operation& o, - const std::tuple<Contracts...>& i) + ExceptionSafetyTestBuilder(const Factory& f, const Operation& o, + const std::tuple<Contracts...>& i) : factory_(f), operation_(o), contracts_(i) {} template <typename SelectedOperation, size_t... Indices> - testing::AssertionResult TestImpl(const SelectedOperation& selected_operation, + testing::AssertionResult TestImpl(SelectedOperation selected_operation, absl::index_sequence<Indices...>) const { - // Starting from 0 and counting upwards until one of the exit conditions is - // hit... - for (int count = 0;; ++count) { - exceptions_internal::ConstructorTracker ct(count); - - // Run the full exception safety test algorithm for the current countdown - auto reduced_res = - TestAllContractsAtCountdown(factory_, selected_operation, count, - std::get<Indices>(contracts_)...); - // If there is no value in the optional, no contracts were run because no - // exception was thrown. This means that the test is complete and the loop - // can exit successfully. - if (!reduced_res.has_value()) { - return testing::AssertionSuccess(); - } - // If the optional is not empty and the value is falsy, an contract check - // failed so the test must exit to propegate the failure. - if (!reduced_res.value()) { - return reduced_res.value(); - } - // If the optional is not empty and the value is not falsy, it means - // exceptions were thrown but the contracts passed so the test must - // continue to run. - } + return ExceptionSafetyTest<FactoryElementType<Factory>>( + factory_, selected_operation, std::get<Indices>(contracts_)...) + .Test(); } Factory factory_; @@ -1090,20 +1082,6 @@ class ExceptionSafetyTester { } // namespace exceptions_internal -/* - * Constructs an empty ExceptionSafetyTester. All ExceptionSafetyTester - * objects are immutable and all With[thing] mutation methods return new - * instances of ExceptionSafetyTester. - * - * In order to test a T for exception safety, a factory for that T, a testable - * operation, and at least one contract callback returning an assertion - * result must be applied using the respective methods. - */ -inline exceptions_internal::ExceptionSafetyTester<> -MakeExceptionSafetyTester() { - return {}; -} - } // namespace testing #endif // ABSL_BASE_INTERNAL_EXCEPTION_SAFETY_TESTING_H_ |