diff options
Diffstat (limited to 'absl/base')
-rw-r--r-- | absl/base/BUILD.bazel | 1 | ||||
-rw-r--r-- | absl/base/exception_safety_testing_test.cc | 250 | ||||
-rw-r--r-- | absl/base/internal/exception_safety_testing.h | 128 |
3 files changed, 195 insertions, 184 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel index e528463345b8..743add7e0127 100644 --- a/absl/base/BUILD.bazel +++ b/absl/base/BUILD.bazel @@ -241,6 +241,7 @@ cc_library( "//absl/memory", "//absl/meta:type_traits", "//absl/strings", + "//absl/types:optional", "@com_google_googletest//:gtest", ], ) diff --git a/absl/base/exception_safety_testing_test.cc b/absl/base/exception_safety_testing_test.cc index 4931c8865af5..20cbb435926a 100644 --- a/absl/base/exception_safety_testing_test.cc +++ b/absl/base/exception_safety_testing_test.cc @@ -384,70 +384,62 @@ struct CallOperator { } }; -struct FailsBasicGuarantee { +struct NonNegative { + friend testing::AssertionResult AbslCheckInvariants(NonNegative* g) { + if (g->i >= 0) return testing::AssertionSuccess(); + return testing::AssertionFailure() + << "i should be non-negative but is " << g->i; + } + bool operator==(const NonNegative& other) const { return i == other.i; } + + int i; +}; + +template <typename T> +struct DefaultFactory { + std::unique_ptr<T> operator()() const { return absl::make_unique<T>(); } +}; + +struct FailsBasicGuarantee : public NonNegative { void operator()() { --i; ThrowingValue<> bomb; ++i; } - - bool operator==(const FailsBasicGuarantee& other) const { - return i == other.i; - } - - friend testing::AssertionResult AbslCheckInvariants( - const FailsBasicGuarantee& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; - } - - int i = 0; }; TEST(ExceptionCheckTest, BasicGuaranteeFailure) { - FailsBasicGuarantee g; - EXPECT_FALSE(TestExceptionSafety(&g, CallOperator{})); + EXPECT_FALSE(TestExceptionSafety(DefaultFactory<FailsBasicGuarantee>(), + CallOperator{})); } -struct FollowsBasicGuarantee { +struct FollowsBasicGuarantee : public NonNegative { void operator()() { ++i; ThrowingValue<> bomb; } - - bool operator==(const FollowsBasicGuarantee& other) const { - return i == other.i; - } - - friend testing::AssertionResult AbslCheckInvariants( - const FollowsBasicGuarantee& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; - } - - int i = 0; }; TEST(ExceptionCheckTest, BasicGuarantee) { - FollowsBasicGuarantee g; - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{})); + EXPECT_TRUE(TestExceptionSafety(DefaultFactory<FollowsBasicGuarantee>(), + CallOperator{})); } TEST(ExceptionCheckTest, StrongGuaranteeFailure) { { - FailsBasicGuarantee g; - EXPECT_FALSE(TestExceptionSafety(&g, CallOperator{}, StrongGuarantee(g))); + DefaultFactory<FailsBasicGuarantee> factory; + EXPECT_FALSE( + TestExceptionSafety(factory, CallOperator{}, StrongGuarantee(factory))); } { - FollowsBasicGuarantee g; - EXPECT_FALSE(TestExceptionSafety(&g, CallOperator{}, StrongGuarantee(g))); + DefaultFactory<FollowsBasicGuarantee> factory; + EXPECT_FALSE( + TestExceptionSafety(factory, CallOperator{}, StrongGuarantee(factory))); } } -struct BasicGuaranteeWithExtraInvariants { +struct BasicGuaranteeWithExtraInvariants : public NonNegative { // After operator(), i is incremented. If operator() throws, i is set to 9999 void operator()() { int old_i = i; @@ -456,92 +448,94 @@ struct BasicGuaranteeWithExtraInvariants { i = ++old_i; } - bool operator==(const FollowsBasicGuarantee& other) const { - return i == other.i; - } - - friend testing::AssertionResult AbslCheckInvariants( - const BasicGuaranteeWithExtraInvariants& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; - } - - int i = 0; static constexpr int kExceptionSentinel = 9999; }; constexpr int BasicGuaranteeWithExtraInvariants::kExceptionSentinel; TEST(ExceptionCheckTest, BasicGuaranteeWithInvariants) { - { - BasicGuaranteeWithExtraInvariants g; - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{})); - } + DefaultFactory<BasicGuaranteeWithExtraInvariants> factory; - { - BasicGuaranteeWithExtraInvariants g; - EXPECT_TRUE(TestExceptionSafety( - &g, CallOperator{}, [](const BasicGuaranteeWithExtraInvariants& w) { - if (w.i == BasicGuaranteeWithExtraInvariants::kExceptionSentinel) { - return testing::AssertionSuccess(); - } - return testing::AssertionFailure() - << "i should be " - << BasicGuaranteeWithExtraInvariants::kExceptionSentinel - << ", but is " << w.i; - })); - } -} + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{})); -struct FollowsStrongGuarantee { + EXPECT_TRUE(TestExceptionSafety( + factory, CallOperator{}, [](BasicGuaranteeWithExtraInvariants* w) { + if (w->i == BasicGuaranteeWithExtraInvariants::kExceptionSentinel) { + return testing::AssertionSuccess(); + } + return testing::AssertionFailure() + << "i should be " + << BasicGuaranteeWithExtraInvariants::kExceptionSentinel + << ", but is " << w->i; + })); +} + +struct FollowsStrongGuarantee : public NonNegative { void operator()() { ThrowingValue<> bomb; } +}; - bool operator==(const FollowsStrongGuarantee& other) const { - return i == other.i; - } +TEST(ExceptionCheckTest, StrongGuarantee) { + DefaultFactory<FollowsStrongGuarantee> factory; + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{})); + EXPECT_TRUE( + TestExceptionSafety(factory, CallOperator{}, StrongGuarantee(factory))); +} - friend testing::AssertionResult AbslCheckInvariants( - const FollowsStrongGuarantee& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; +struct HasReset : public NonNegative { + void operator()() { + i = -1; + ThrowingValue<> bomb; + i = 1; } - int i = 0; + void reset() { i = 0; } + + friend bool AbslCheckInvariants(HasReset* h) { + h->reset(); + return h->i == 0; + } }; -TEST(ExceptionCheckTest, StrongGuarantee) { - FollowsStrongGuarantee g; - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{})); - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{}, StrongGuarantee(g))); +TEST(ExceptionCheckTest, ModifyingChecker) { + { + DefaultFactory<FollowsBasicGuarantee> factory; + EXPECT_FALSE(TestExceptionSafety( + factory, CallOperator{}, + [](FollowsBasicGuarantee* g) { + g->i = 1000; + return true; + }, + [](FollowsBasicGuarantee* g) { return g->i == 1000; })); + } + { + DefaultFactory<FollowsStrongGuarantee> factory; + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{}, + [](FollowsStrongGuarantee* g) { + ++g->i; + return true; + }, + StrongGuarantee(factory))); + } + { + DefaultFactory<HasReset> factory; + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{})); + } } -struct NonCopyable { +struct NonCopyable : public NonNegative { NonCopyable(const NonCopyable&) = delete; - explicit NonCopyable(int ii) : i(ii) {} + NonCopyable() : NonNegative{0} {} void operator()() { ThrowingValue<> bomb; } - - bool operator==(const NonCopyable& other) const { return i == other.i; } - - friend testing::AssertionResult AbslCheckInvariants(const NonCopyable& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; - } - - int i; }; TEST(ExceptionCheckTest, NonCopyable) { - NonCopyable g(0); - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{})); - EXPECT_TRUE(TestExceptionSafety( - &g, CallOperator{}, - PointeeStrongGuarantee(absl::make_unique<NonCopyable>(g.i)))); + DefaultFactory<NonCopyable> factory; + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{})); + EXPECT_TRUE( + TestExceptionSafety(factory, CallOperator{}, StrongGuarantee(factory))); } -struct NonEqualityComparable { +struct NonEqualityComparable : public NonNegative { void operator()() { ThrowingValue<> bomb; } void ModifyOnThrow() { @@ -550,71 +544,61 @@ struct NonEqualityComparable { static_cast<void>(bomb); --i; } - - friend testing::AssertionResult AbslCheckInvariants( - const NonEqualityComparable& g) { - if (g.i >= 0) return testing::AssertionSuccess(); - return testing::AssertionFailure() - << "i should be non-negative but is " << g.i; - } - - int i = 0; }; TEST(ExceptionCheckTest, NonEqualityComparable) { - NonEqualityComparable g; + DefaultFactory<NonEqualityComparable> factory; auto comp = [](const NonEqualityComparable& a, const NonEqualityComparable& b) { return a.i == b.i; }; - EXPECT_TRUE(TestExceptionSafety(&g, CallOperator{})); - EXPECT_TRUE( - TestExceptionSafety(&g, CallOperator{}, absl::StrongGuarantee(g, comp))); + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{})); + EXPECT_TRUE(TestExceptionSafety(factory, CallOperator{}, + absl::StrongGuarantee(factory, comp))); EXPECT_FALSE(TestExceptionSafety( - &g, [&](NonEqualityComparable* n) { n->ModifyOnThrow(); }, - absl::StrongGuarantee(g, comp))); + factory, [&](NonEqualityComparable* n) { n->ModifyOnThrow(); }, + absl::StrongGuarantee(factory, comp))); } template <typename T> -struct InstructionCounter { +struct ExhaustivenessTester { void operator()() { - ++counter; + successes |= 1; T b1; static_cast<void>(b1); - ++counter; + successes |= (1 << 1); T b2; static_cast<void>(b2); - ++counter; + successes |= (1 << 2); T b3; static_cast<void>(b3); - ++counter; + successes |= (1 << 3); } - bool operator==(const InstructionCounter<ThrowingValue<>>&) const { + bool operator==(const ExhaustivenessTester<ThrowingValue<>>&) const { return true; } - friend testing::AssertionResult AbslCheckInvariants( - const InstructionCounter&) { + friend testing::AssertionResult AbslCheckInvariants(ExhaustivenessTester*) { return testing::AssertionSuccess(); } - static int counter; + static unsigned char successes; }; template <typename T> -int InstructionCounter<T>::counter = 0; +unsigned char ExhaustivenessTester<T>::successes = 0; TEST(ExceptionCheckTest, Exhaustiveness) { - InstructionCounter<int> int_factory; - EXPECT_TRUE(TestExceptionSafety(&int_factory, CallOperator{})); - EXPECT_EQ(InstructionCounter<int>::counter, 4); + DefaultFactory<ExhaustivenessTester<int>> int_factory; + EXPECT_TRUE(TestExceptionSafety(int_factory, CallOperator{})); + EXPECT_EQ(ExhaustivenessTester<int>::successes, 0xF); - InstructionCounter<ThrowingValue<>> bomb_factory; - EXPECT_TRUE(TestExceptionSafety(&bomb_factory, CallOperator{})); - EXPECT_EQ(InstructionCounter<ThrowingValue<>>::counter, 10); + DefaultFactory<ExhaustivenessTester<ThrowingValue<>>> bomb_factory; + EXPECT_TRUE(TestExceptionSafety(bomb_factory, CallOperator{})); + EXPECT_EQ(ExhaustivenessTester<ThrowingValue<>>::successes, 0xF); - InstructionCounter<ThrowingValue<>>::counter = 0; - EXPECT_TRUE(TestExceptionSafety(&bomb_factory, CallOperator{}, + ExhaustivenessTester<ThrowingValue<>>::successes = 0; + EXPECT_TRUE(TestExceptionSafety(bomb_factory, CallOperator{}, StrongGuarantee(bomb_factory))); - EXPECT_EQ(InstructionCounter<ThrowingValue<>>::counter, 10); + EXPECT_EQ(ExhaustivenessTester<ThrowingValue<>>::successes, 0xF); } struct LeaksIfCtorThrows : private exceptions_internal::TrackedObject { diff --git a/absl/base/internal/exception_safety_testing.h b/absl/base/internal/exception_safety_testing.h index a0a70d91d2d9..05bcd0ab59d6 100644 --- a/absl/base/internal/exception_safety_testing.h +++ b/absl/base/internal/exception_safety_testing.h @@ -18,6 +18,7 @@ #include "absl/meta/type_traits.h" #include "absl/strings/string_view.h" #include "absl/strings/substitute.h" +#include "absl/types/optional.h" namespace absl { struct AllocInspector; @@ -97,19 +98,50 @@ class TrackedObject { friend struct ::absl::AllocInspector; }; -template <typename T, typename... Checkers> -testing::AssertionResult TestInvariants(const T& t, const TestException& e, - int count, - const Checkers&... checkers) { - auto out = AbslCheckInvariants(t); +template <typename Factory> +using FactoryType = typename absl::result_of_t<Factory()>::element_type; + +// Returns an optional with the result of the check if op fails, or an empty +// optional if op passes +template <typename Factory, typename Op, typename Checker> +absl::optional<testing::AssertionResult> TestCheckerAtCountdown( + Factory factory, const Op& op, int count, const Checker& check) { + exceptions_internal::countdown = count; + auto t_ptr = factory(); + absl::optional<testing::AssertionResult> out; + try { + op(t_ptr.get()); + } catch (const exceptions_internal::TestException& e) { + out.emplace(check(t_ptr.get())); + if (!*out) { + *out << " caused by exception thrown by " << e.what(); + } + } + return out; +} + +template <typename Factory, typename Op, typename Checker> +int UpdateOut(Factory factory, const Op& op, int count, const Checker& checker, + testing::AssertionResult* out) { + if (*out) *out = *TestCheckerAtCountdown(factory, op, count, checker); + return 0; +} + +// Returns an optional with the result of the check if op fails, or an empty +// optional if op passes +template <typename Factory, typename Op, typename... Checkers> +absl::optional<testing::AssertionResult> TestAtCountdown( + Factory factory, const Op& op, int count, const Checkers&... checkers) { // Don't bother with the checkers if the class invariants are already broken. - bool dummy[] = {true, - (out && (out = testing::AssertionResult(checkers(t))))...}; - static_cast<void>(dummy); + auto out = TestCheckerAtCountdown( + factory, op, count, + [](FactoryType<Factory>* t_ptr) { return AbslCheckInvariants(t_ptr); }); + if (!out.has_value()) return out; - return out ? out - : out << " Caused by exception " << count << "thrown by " - << e.what(); + // Run each checker, short circuiting after the first failure + int dummy[] = {0, (UpdateOut(factory, op, count, checkers, &*out))...}; + static_cast<void>(dummy); + return out; } template <typename T, typename EqualTo> @@ -118,9 +150,9 @@ class StrongGuaranteeTester { explicit StrongGuaranteeTester(std::unique_ptr<T> t_ptr, EqualTo eq) noexcept : val_(std::move(t_ptr)), eq_(eq) {} - testing::AssertionResult operator()(const T& other) const { - return eq_(*val_, other) ? testing::AssertionSuccess() - : testing::AssertionFailure() << "State changed"; + testing::AssertionResult operator()(T* other) const { + return eq_(*val_, *other) ? testing::AssertionSuccess() + : testing::AssertionFailure() << "State changed"; } private: @@ -673,58 +705,52 @@ T TestThrowingCtor(Args&&... args) { } // Tests that performing operation Op on a T follows exception safety -// guarantees. By default only tests the basic guarantee. +// guarantees. By default only tests the basic guarantee. There must be a +// function, AbslCheckInvariants(T*) which returns +// anything convertible to bool and which makes sure the invariants of the type +// are upheld. This is called before any of the checkers. // // Parameters: -// * T: the type under test. +// * TFactory: operator() returns a unique_ptr to the type under test (T). It +// should always return pointers to values which compare equal. // * FunctionFromTPtrToVoid: A functor exercising the function under test. It // should take a T* and return void. -// * Checkers: Any number of functions taking a const T& and returning +// * Checkers: Any number of functions taking a T* and returning // anything contextually convertible to bool. If a testing::AssertionResult // is used then the error message is kept. These test invariants related to // the operation. To test the strong guarantee, pass -// absl::StrongGuarantee(...) as one of these arguments if T has operator==. -// Some types for which the strong guarantee makes sense don't have operator== -// (eg std::any). A function capturing *t or a T equal to it, taking a const -// T&, and returning contextually-convertible-to-bool may be passed instead. -template <typename T, typename FunctionFromTPtrToVoid, typename... Checkers> -testing::AssertionResult TestExceptionSafety(T* t, FunctionFromTPtrToVoid&& op, +// absl::StrongGuarantee(factory). A checker may freely modify the passed-in +// T, for example to make sure the T can be set to a known state. +template <typename TFactory, typename FunctionFromTPtrToVoid, + typename... Checkers> +testing::AssertionResult TestExceptionSafety(TFactory factory, + FunctionFromTPtrToVoid&& op, const Checkers&... checkers) { - auto out = testing::AssertionSuccess(); for (int countdown = 0;; ++countdown) { - exceptions_internal::countdown = countdown; - try { - op(t); - break; - } catch (const exceptions_internal::TestException& e) { - out = exceptions_internal::TestInvariants(*t, e, countdown, checkers...); - if (!out) return out; + auto out = exceptions_internal::TestAtCountdown(factory, op, countdown, + checkers...); + if (!out.has_value()) { + UnsetCountdown(); + return testing::AssertionSuccess(); } + if (!*out) return *out; } - UnsetCountdown(); - return out; } -// Returns a functor to test for the strong exception-safety guarantee. If T is -// copyable, use the const T& overload, otherwise pass a unique_ptr<T>. -// Equality comparisons are made against the T provided and default to using -// operator==. See the documentation for TestExceptionSafety if T doesn't have -// operator== but the strong guarantee still makes sense for it. +// Returns a functor to test for the strong exception-safety guarantee. +// Equality comparisons are made against the T provided by the factory and +// default to using operator==. // // Parameters: -// * T: The type under test. -template <typename T, typename EqualTo = std::equal_to<T>> -exceptions_internal::StrongGuaranteeTester<T, EqualTo> StrongGuarantee( - const T& t, EqualTo eq = EqualTo()) { - return exceptions_internal::StrongGuaranteeTester<T, EqualTo>( - absl::make_unique<T>(t), eq); -} - -template <typename T, typename EqualTo = std::equal_to<T>> -exceptions_internal::StrongGuaranteeTester<T, EqualTo> PointeeStrongGuarantee( - std::unique_ptr<T> t_ptr, EqualTo eq = EqualTo()) { - return exceptions_internal::StrongGuaranteeTester<T, EqualTo>( - std::move(t_ptr), eq); +// * TFactory: operator() returns a unique_ptr to the type under test. It +// should always return pointers to values which compare equal. +template <typename TFactory, typename EqualTo = std::equal_to< + exceptions_internal::FactoryType<TFactory>>> +exceptions_internal::StrongGuaranteeTester< + exceptions_internal::FactoryType<TFactory>, EqualTo> +StrongGuarantee(TFactory factory, EqualTo eq = EqualTo()) { + return exceptions_internal::StrongGuaranteeTester< + exceptions_internal::FactoryType<TFactory>, EqualTo>(factory(), eq); } } // namespace absl |