From e4c8d0eb8ef4acb5d7a4252b3b87feb391ef7e41 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Fri, 18 Oct 2019 09:06:29 -0700 Subject: [PATCH] Export of internal Abseil changes -- a9ac6567c0933d786d68c10011e3f3ff9deedf89 by Greg Falcon : Add absl::FunctionRef, a type analogous to the proposed C++23 std::function_ref. Like std::function, FunctionRef can be used to type-erase any callable (invokable) object. However, FunctionRef works by reference: it does not store a copy of the type-erased object. If the wrapped object is destroyed before the FunctionRef, the reference becomes dangling. FunctionRef relates to std::function in much the same way that string_view relates to std::string. Because of these limitations, FunctionRef is best used only as a function argument type, and only where the function will be invoked immediately (rather than saved for later use). When `const std::function<...>&` is used in this way, `absl::FunctionRef<...>` is a better-performing replacement. PiperOrigin-RevId: 275484044 -- 1f7c4df3760f8b93e5a5baf40b070eca1d3f4c98 by Abseil Team : Add FastHexToBufferZeroPad16() function for blazingly fast hex encoding of uint64_t. PiperOrigin-RevId: 275420901 -- 08d48ac004eba57cf2f1ada827181a2995f74807 by Abseil Team : Avoid applying the workaround for MSVC's static initialization problems when using clang-cl. PiperOrigin-RevId: 275366326 -- 40be82bd2b34670b5458c0a72a0475086153c2d6 by Abseil Team : Added comments to SimpleAtof()/SimpleAtod() that clarify that they always use the "C" locale, unlike the standard functions strtod() and strtof() referenced now in the comments. PiperOrigin-RevId: 275355815 -- 086779dacb3f6f2b3ab59947e94e79046bdb1fe1 by Jorg Brown : Move the hex conversion table used by escaping.cc into numbers.h so that other parts of Abseil can more efficiently access it. PiperOrigin-RevId: 275331251 -- 3c4ed1b04e55d96a40cbe70fb70929ffbb0c0432 by Abseil Team : Avoid applying the workaround for MSVC's static initialization problems when using clang-cl. PiperOrigin-RevId: 275323858 -- 56ceb58ab688c3761978308609b09a1ac2739c9a by Derek Mauro : Add script for testing on Alpine Linux (for musl test coverage) PiperOrigin-RevId: 275321244 GitOrigin-RevId: a9ac6567c0933d786d68c10011e3f3ff9deedf89 Change-Id: I39799fa03768ddb44f3166200c860e1da4461807 --- absl/functional/BUILD.bazel | 51 +++++ absl/functional/function_ref.h | 137 ++++++++++++ absl/functional/function_ref_benchmark.cc | 140 ++++++++++++ absl/functional/function_ref_test.cc | 255 ++++++++++++++++++++++ absl/functional/internal/function_ref.h | 104 +++++++++ absl/strings/BUILD.bazel | 5 +- absl/strings/CMakeLists.txt | 2 + absl/strings/escaping.cc | 33 +-- absl/strings/numbers.cc | 29 ++- absl/strings/numbers.h | 45 +++- absl/strings/numbers_benchmark.cc | 23 ++ absl/strings/numbers_test.cc | 30 ++- absl/strings/str_cat.cc | 5 +- absl/strings/substitute.cc | 5 +- ci/linux_gcc_alpine_cmake.sh | 63 ++++++ 15 files changed, 887 insertions(+), 40 deletions(-) create mode 100644 absl/functional/BUILD.bazel create mode 100644 absl/functional/function_ref.h create mode 100644 absl/functional/function_ref_benchmark.cc create mode 100644 absl/functional/function_ref_test.cc create mode 100644 absl/functional/internal/function_ref.h create mode 100755 ci/linux_gcc_alpine_cmake.sh diff --git a/absl/functional/BUILD.bazel b/absl/functional/BUILD.bazel new file mode 100644 index 00000000..e861b8a5 --- /dev/null +++ b/absl/functional/BUILD.bazel @@ -0,0 +1,51 @@ +load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test") +load( + "//absl:copts/configure_copts.bzl", + "ABSL_DEFAULT_COPTS", + "ABSL_DEFAULT_LINKOPTS", + "ABSL_TEST_COPTS", +) + +package(default_visibility = ["//visibility:public"]) + +licenses(["notice"]) # Apache 2.0 + +cc_library( + name = "function_ref", + srcs = ["internal/function_ref.h"], + hdrs = ["function_ref.h"], + copts = ABSL_DEFAULT_COPTS, + linkopts = ABSL_DEFAULT_LINKOPTS, + deps = [ + "//absl/base:base_internal", + "//absl/meta:type_traits", + ], +) + +cc_test( + name = "function_ref_test", + size = "small", + srcs = ["function_ref_test.cc"], + copts = ABSL_TEST_COPTS, + deps = [ + ":function_ref", + "//absl/container:test_instance_tracker", + "//absl/memory", + "@com_google_googletest//:gtest_main", + ], +) + +cc_test( + name = "function_ref_benchmark", + srcs = [ + "function_ref_benchmark.cc", + ], + copts = ABSL_TEST_COPTS, + tags = ["benchmark"], + visibility = ["//visibility:private"], + deps = [ + ":function_ref", + "//absl/base:core_headers", + "@com_github_google_benchmark//:benchmark_main", + ], +) diff --git a/absl/functional/function_ref.h b/absl/functional/function_ref.h new file mode 100644 index 00000000..42d9f16f --- /dev/null +++ b/absl/functional/function_ref.h @@ -0,0 +1,137 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// ----------------------------------------------------------------------------- +// File: function_ref.h +// ----------------------------------------------------------------------------- +// +// This header file defines the `absl::FunctionRef` type for holding a +// non-owning reference to an object of any invocable type. This function +// reference is typically most useful as a type-erased argument type for +// accepting function types that neither take ownership nor copy the type; using +// the reference type in this case avoids a copy and an allocation. Best +// practices of other non-owning reference-like objects (such as +// `absl::string_view`) apply here. +// +// An `absl::FunctionRef` is similar in usage to a `std::function` but has the +// following differences: +// +// * It doesn't own the underlying object. +// * It doesn't have a null or empty state. +// * It never performs deep copies or allocations. +// * It's much faster and cheaper to construct. +// * It's trivially copyable and destructable. +// +// Generally, `absl::FunctionRef` should not be used as a return value, data +// member, or to initialize a `std::function`. Such usages will often lead to +// problematic lifetime issues. Once you convert something to an +// `absl::FunctionRef` you cannot make a deep copy later. +// +// This class is suitable for use wherever a "const std::function<>&" +// would be used without making a copy. ForEach functions and other versions of +// the visitor pattern are a good example of when this class should be used. +// +// This class is trivial to copy and should be passed by value. +#ifndef ABSL_FUNCTIONAL_FUNCTION_REF_H_ +#define ABSL_FUNCTIONAL_FUNCTION_REF_H_ + +#include +#include +#include + +#include "absl/functional/internal/function_ref.h" +#include "absl/meta/type_traits.h" + +namespace absl { + +// FunctionRef +// +// Dummy class declaration to allow the partial specialization based on function +// types below. +template +class FunctionRef; + +// FunctionRef +// +// An `absl::FunctionRef` is a lightweight wrapper to any invokable object with +// a compatible signature. Generally, an `absl::FunctionRef` should only be used +// as an argument type and should be preferred as an argument over a const +// reference to a `std::function`. +// +// Example: +// +// // The following function takes a function callback by const reference +// bool Visitor(const std::function& callback); +// +// // Assuming that the function is not stored or otherwise copied, it can be +// // replaced by an `absl::FunctionRef`: +// bool Visitor(absl::FunctionRef +// callback); +// +// Note: the assignment operator within an `absl::FunctionRef` is intentionally +// deleted to prevent misuse; because the `absl::FunctionRef` does not own the +// underlying type, assignment likely indicates misuse. +template +class FunctionRef { + private: + // Used to disable constructors for objects that are not compatible with the + // signature of this FunctionRef. + template > + using EnableIfCompatible = + typename std::enable_if::value || + std::is_convertible::value>::type; + + public: + // Constructs a FunctionRef from any invokable type. + template > + FunctionRef(const F& f) // NOLINT(runtime/explicit) + : invoker_(&absl::functional_internal::InvokeObject) { + absl::functional_internal::AssertNonNull(f); + ptr_.obj = &f; + } + + // Overload for function pointers. This eliminates a level of indirection that + // would happen if the above overload was used (it lets us store the pointer + // instead of a pointer to a pointer). + // + // This overload is also used for references to functions, since references to + // functions can decay to function pointers implicitly. + template < + typename F, typename = EnableIfCompatible, + absl::functional_internal::EnableIf::value> = 0> + FunctionRef(F* f) // NOLINT(runtime/explicit) + : invoker_(&absl::functional_internal::InvokeFunction) { + assert(f != nullptr); + ptr_.fun = reinterpret_cast(f); + } + + // To help prevent subtle lifetime bugs, FunctionRef is not assignable. + // Typically, it should only be used as an argument type. + FunctionRef& operator=(const FunctionRef& rhs) = delete; + + // Call the underlying object. + R operator()(Args... args) const { + return invoker_(ptr_, std::forward(args)...); + } + + private: + absl::functional_internal::VoidPtr ptr_; + absl::functional_internal::Invoker invoker_; +}; + +} // namespace absl + +#endif // ABSL_FUNCTIONAL_FUNCTION_REF_H_ diff --git a/absl/functional/function_ref_benchmark.cc b/absl/functional/function_ref_benchmark.cc new file mode 100644 index 00000000..f6dfcabf --- /dev/null +++ b/absl/functional/function_ref_benchmark.cc @@ -0,0 +1,140 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/functional/function_ref.h" + +#include + +#include "benchmark/benchmark.h" +#include "absl/base/attributes.h" + +namespace absl { +namespace { + +int dummy = 0; + +void FreeFunction() { benchmark::DoNotOptimize(dummy); } + +struct TrivialFunctor { + void operator()() const { benchmark::DoNotOptimize(dummy); } +}; + +struct LargeFunctor { + void operator()() const { benchmark::DoNotOptimize(this); } + std::string a, b, c; +}; + +template +void ABSL_ATTRIBUTE_NOINLINE CallFunction(Function f, Args&&... args) { + f(std::forward(args)...); +} + +template +void ConstructAndCallFunctionBenchmark(benchmark::State& state, + const Callable& c, Args&&... args) { + for (auto _ : state) { + CallFunction(c, std::forward(args)...); + } +} + +void BM_TrivialStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + TrivialFunctor{}); +} +BENCHMARK(BM_TrivialStdFunction); + +void BM_TrivialFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + TrivialFunctor{}); +} +BENCHMARK(BM_TrivialFunctionRef); + +void BM_LargeStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + LargeFunctor{}); +} +BENCHMARK(BM_LargeStdFunction); + +void BM_LargeFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, LargeFunctor{}); +} +BENCHMARK(BM_LargeFunctionRef); + +void BM_FunPtrStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, FreeFunction); +} +BENCHMARK(BM_FunPtrStdFunction); + +void BM_FunPtrFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, FreeFunction); +} +BENCHMARK(BM_FunPtrFunctionRef); + +// Doesn't include construction or copy overhead in the loop. +template +void CallFunctionBenchmark(benchmark::State& state, const Callable& c, + Args... args) { + Function f = c; + for (auto _ : state) { + benchmark::DoNotOptimize(&f); + f(args...); + } +} + +struct FunctorWithTrivialArgs { + void operator()(int a, int b, int c) const { + benchmark::DoNotOptimize(a); + benchmark::DoNotOptimize(b); + benchmark::DoNotOptimize(c); + } +}; + +void BM_TrivialArgsStdFunction(benchmark::State& state) { + CallFunctionBenchmark>( + state, FunctorWithTrivialArgs{}, 1, 2, 3); +} +BENCHMARK(BM_TrivialArgsStdFunction); + +void BM_TrivialArgsFunctionRef(benchmark::State& state) { + CallFunctionBenchmark>( + state, FunctorWithTrivialArgs{}, 1, 2, 3); +} +BENCHMARK(BM_TrivialArgsFunctionRef); + +struct FunctorWithNonTrivialArgs { + void operator()(std::string a, std::string b, std::string c) const { + benchmark::DoNotOptimize(&a); + benchmark::DoNotOptimize(&b); + benchmark::DoNotOptimize(&c); + } +}; + +void BM_NonTrivialArgsStdFunction(benchmark::State& state) { + std::string a, b, c; + CallFunctionBenchmark< + std::function>( + state, FunctorWithNonTrivialArgs{}, a, b, c); +} +BENCHMARK(BM_NonTrivialArgsStdFunction); + +void BM_NonTrivialArgsFunctionRef(benchmark::State& state) { + std::string a, b, c; + CallFunctionBenchmark< + FunctionRef>( + state, FunctorWithNonTrivialArgs{}, a, b, c); +} +BENCHMARK(BM_NonTrivialArgsFunctionRef); + +} // namespace +} // namespace absl diff --git a/absl/functional/function_ref_test.cc b/absl/functional/function_ref_test.cc new file mode 100644 index 00000000..90829db0 --- /dev/null +++ b/absl/functional/function_ref_test.cc @@ -0,0 +1,255 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/functional/function_ref.h" + +#include + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "absl/container/internal/test_instance_tracker.h" +#include "absl/memory/memory.h" + +namespace absl { +namespace { + +void RunFun(FunctionRef f) { f(); } + +TEST(FunctionRefTest, Lambda) { + bool ran = false; + RunFun([&] { ran = true; }); + EXPECT_TRUE(ran); +} + +int Function() { return 1337; } + +TEST(FunctionRefTest, Function1) { + FunctionRef ref(&Function); + EXPECT_EQ(1337, ref()); +} + +TEST(FunctionRefTest, Function2) { + FunctionRef ref(Function); + EXPECT_EQ(1337, ref()); +} + +int NoExceptFunction() noexcept { return 1337; } + +// TODO(jdennett): Add a test for noexcept member functions. +TEST(FunctionRefTest, NoExceptFunction) { + FunctionRef ref(NoExceptFunction); + EXPECT_EQ(1337, ref()); +} + +TEST(FunctionRefTest, ForwardsArgs) { + auto l = [](std::unique_ptr i) { return *i; }; + FunctionRef)> ref(l); + EXPECT_EQ(42, ref(absl::make_unique(42))); +} + +TEST(FunctionRef, ReturnMoveOnly) { + auto l = [] { return absl::make_unique(29); }; + FunctionRef()> ref(l); + EXPECT_EQ(29, *ref()); +} + +TEST(FunctionRef, ManyArgs) { + auto l = [](int a, int b, int c) { return a + b + c; }; + FunctionRef ref(l); + EXPECT_EQ(6, ref(1, 2, 3)); +} + +TEST(FunctionRef, VoidResultFromNonVoidFunctor) { + bool ran = false; + auto l = [&]() -> int { + ran = true; + return 2; + }; + FunctionRef ref(l); + ref(); + EXPECT_TRUE(ran); +} + +TEST(FunctionRef, CastFromDerived) { + struct Base {}; + struct Derived : public Base {}; + + Derived d; + auto l1 = [&](Base* b) { EXPECT_EQ(&d, b); }; + FunctionRef ref1(l1); + ref1(&d); + + auto l2 = [&]() -> Derived* { return &d; }; + FunctionRef ref2(l2); + EXPECT_EQ(&d, ref2()); +} + +TEST(FunctionRef, VoidResultFromNonVoidFuncton) { + FunctionRef ref(Function); + ref(); +} + +TEST(FunctionRef, MemberPtr) { + struct S { + int i; + }; + + S s{1100111}; + auto mem_ptr = &S::i; + FunctionRef ref(mem_ptr); + EXPECT_EQ(1100111, ref(s)); +} + +TEST(FunctionRef, MemberFun) { + struct S { + int i; + int get_i() const { return i; } + }; + + S s{22}; + auto mem_fun_ptr = &S::get_i; + FunctionRef ref(mem_fun_ptr); + EXPECT_EQ(22, ref(s)); +} + +TEST(FunctionRef, MemberFunRefqualified) { + struct S { + int i; + int get_i() && { return i; } + }; + auto mem_fun_ptr = &S::get_i; + S s{22}; + FunctionRef ref(mem_fun_ptr); + EXPECT_EQ(22, ref(std::move(s))); +} + +#if !defined(_WIN32) && defined(GTEST_HAS_DEATH_TEST) + +TEST(FunctionRef, MemberFunRefqualifiedNull) { + struct S { + int i; + int get_i() && { return i; } + }; + auto mem_fun_ptr = &S::get_i; + mem_fun_ptr = nullptr; + EXPECT_DEBUG_DEATH({ FunctionRef ref(mem_fun_ptr); }, ""); +} + +TEST(FunctionRef, NullMemberPtrAssertFails) { + struct S { + int i; + }; + using MemberPtr = int S::*; + MemberPtr mem_ptr = nullptr; + EXPECT_DEBUG_DEATH({ FunctionRef ref(mem_ptr); }, ""); +} + +#endif // GTEST_HAS_DEATH_TEST + +TEST(FunctionRef, CopiesAndMovesPerPassByValue) { + absl::test_internal::InstanceTracker tracker; + absl::test_internal::CopyableMovableInstance instance(0); + auto l = [](absl::test_internal::CopyableMovableInstance) {}; + FunctionRef ref(l); + ref(instance); + EXPECT_EQ(tracker.copies(), 1); + EXPECT_EQ(tracker.moves(), 1); +} + +TEST(FunctionRef, CopiesAndMovesPerPassByRef) { + absl::test_internal::InstanceTracker tracker; + absl::test_internal::CopyableMovableInstance instance(0); + auto l = [](const absl::test_internal::CopyableMovableInstance&) {}; + FunctionRef ref(l); + ref(instance); + EXPECT_EQ(tracker.copies(), 0); + EXPECT_EQ(tracker.moves(), 0); +} + +TEST(FunctionRef, CopiesAndMovesPerPassByValueCallByMove) { + absl::test_internal::InstanceTracker tracker; + absl::test_internal::CopyableMovableInstance instance(0); + auto l = [](absl::test_internal::CopyableMovableInstance) {}; + FunctionRef ref(l); + ref(std::move(instance)); + EXPECT_EQ(tracker.copies(), 0); + EXPECT_EQ(tracker.moves(), 2); +} + +TEST(FunctionRef, CopiesAndMovesPerPassByValueToRef) { + absl::test_internal::InstanceTracker tracker; + absl::test_internal::CopyableMovableInstance instance(0); + auto l = [](const absl::test_internal::CopyableMovableInstance&) {}; + FunctionRef ref(l); + ref(std::move(instance)); + EXPECT_EQ(tracker.copies(), 0); + EXPECT_EQ(tracker.moves(), 1); +} + +TEST(FunctionRef, PassByValueTypes) { + using absl::functional_internal::Invoker; + using absl::functional_internal::VoidPtr; + using absl::test_internal::CopyableMovableInstance; + struct Trivial { + void* p[2]; + }; + struct LargeTrivial { + void* p[3]; + }; + + static_assert(std::is_same, void (*)(VoidPtr, int)>::value, + "Scalar types should be passed by value"); + static_assert( + std::is_same, void (*)(VoidPtr, Trivial)>::value, + "Small trivial types should be passed by value"); + static_assert(std::is_same, + void (*)(VoidPtr, LargeTrivial &&)>::value, + "Large trivial types should be passed by rvalue reference"); + static_assert( + std::is_same, + void (*)(VoidPtr, CopyableMovableInstance &&)>::value, + "Types with copy/move ctor should be passed by rvalue reference"); + + // References are passed as references. + static_assert( + std::is_same, void (*)(VoidPtr, int&)>::value, + "Reference types should be preserved"); + static_assert( + std::is_same, + void (*)(VoidPtr, CopyableMovableInstance&)>::value, + "Reference types should be preserved"); + static_assert( + std::is_same, + void (*)(VoidPtr, CopyableMovableInstance &&)>::value, + "Reference types should be preserved"); + + // Make sure the address of an object received by reference is the same as the + // addess of the object passed by the caller. + { + LargeTrivial obj; + auto test = [&obj](LargeTrivial& input) { ASSERT_EQ(&input, &obj); }; + absl::FunctionRef ref(test); + ref(obj); + } + + { + Trivial obj; + auto test = [&obj](Trivial& input) { ASSERT_EQ(&input, &obj); }; + absl::FunctionRef ref(test); + ref(obj); + } +} + +} // namespace +} // namespace absl diff --git a/absl/functional/internal/function_ref.h b/absl/functional/internal/function_ref.h new file mode 100644 index 00000000..fcb0496c --- /dev/null +++ b/absl/functional/internal/function_ref.h @@ -0,0 +1,104 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#ifndef ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ +#define ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ + +#include +#include +#include + +#include "absl/base/internal/invoke.h" +#include "absl/meta/type_traits.h" + +namespace absl { +namespace functional_internal { + +// Like a void* that can handle function pointers as well. The standard does not +// allow function pointers to round-trip through void*, but void(*)() is fine. +// +// Note: It's important that this class remains trivial and is the same size as +// a pointer, since this allows the compiler to perform tail-call optimizations +// when the underlying function is a callable object with a matching signature. +union VoidPtr { + const void* obj; + void (*fun)(); +}; + +// Chooses the best type for passing T as an argument. +// Attempt to be close to SystemV AMD64 ABI. Objects with trivial copy ctor are +// passed by value. +template +constexpr bool PassByValue() { + return !std::is_lvalue_reference::value && + absl::is_trivially_copy_constructible::value && + absl::is_trivially_copy_assignable< + typename std::remove_cv::type>::value && + std::is_trivially_destructible::value && + sizeof(T) <= 2 * sizeof(void*); +} + +template +struct ForwardT : std::conditional(), T, T&&> {}; + +// An Invoker takes a pointer to the type-erased invokable object, followed by +// the arguments that the invokable object expects. +// +// Note: The order of arguments here is an optimization, since member functions +// have an implicit "this" pointer as their first argument, putting VoidPtr +// first allows the compiler to perform tail-call optimization in many cases. +template +using Invoker = R (*)(VoidPtr, typename ForwardT::type...); + +// +// InvokeObject and InvokeFunction provide static "Invoke" functions that can be +// used as Invokers for objects or functions respectively. +// +// static_cast handles the case the return type is void. +template +R InvokeObject(VoidPtr ptr, typename ForwardT::type... args) { + auto o = static_cast(ptr.obj); + return static_cast( + absl::base_internal::Invoke(*o, std::forward(args)...)); +} + +template +R InvokeFunction(VoidPtr ptr, typename ForwardT::type... args) { + auto f = reinterpret_cast(ptr.fun); + return static_cast( + absl::base_internal::Invoke(f, std::forward(args)...)); +} + +template +void AssertNonNull(const std::function& f) { + assert(f != nullptr); + (void)f; +} + +template +void AssertNonNull(const F&) {} + +template +void AssertNonNull(F C::*f) { + assert(f != nullptr); + (void)f; +} + +template +using EnableIf = typename ::std::enable_if::type; + +} // namespace functional_internal +} // namespace absl + +#endif // ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel index 4863ead2..e38c8ad6 100644 --- a/absl/strings/BUILD.bazel +++ b/absl/strings/BUILD.bazel @@ -413,8 +413,9 @@ cc_test( deps = [ ":pow10_helper", ":strings", - "//absl/base:core_headers", "//absl/base:raw_logging_internal", + "//absl/random", + "//absl/random:distributions", "@com_google_googletest//:gtest_main", ], ) @@ -428,6 +429,8 @@ cc_test( deps = [ ":strings", "//absl/base:raw_logging_internal", + "//absl/random", + "//absl/random:distributions", "@com_github_google_benchmark//:benchmark_main", ], ) diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt index 3f907957..cd52a472 100644 --- a/absl/strings/CMakeLists.txt +++ b/absl/strings/CMakeLists.txt @@ -277,6 +277,8 @@ absl_cc_test( absl::core_headers absl::pow10_helper absl::raw_logging_internal + absl::random_random + absl::random_distributions gmock_main ) diff --git a/absl/strings/escaping.cc b/absl/strings/escaping.cc index 0d336e3f..88390fbf 100644 --- a/absl/strings/escaping.cc +++ b/absl/strings/escaping.cc @@ -35,27 +35,6 @@ namespace absl { namespace { -// Digit conversion. -constexpr char kHexChar[] = "0123456789abcdef"; - -constexpr char kHexTable[513] = - "000102030405060708090a0b0c0d0e0f" - "101112131415161718191a1b1c1d1e1f" - "202122232425262728292a2b2c2d2e2f" - "303132333435363738393a3b3c3d3e3f" - "404142434445464748494a4b4c4d4e4f" - "505152535455565758595a5b5c5d5e5f" - "606162636465666768696a6b6c6d6e6f" - "707172737475767778797a7b7c7d7e7f" - "808182838485868788898a8b8c8d8e8f" - "909192939495969798999a9b9c9d9e9f" - "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf" - "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf" - "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf" - "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf" - "e0e1e2e3e4e5e6e7e8e9eaebecedeeef" - "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"; - // These are used for the leave_nulls_escaped argument to CUnescapeInternal(). constexpr bool kUnescapeNulls = false; @@ -348,14 +327,14 @@ std::string CEscapeInternal(absl::string_view src, bool use_hex, (last_hex_escape && absl::ascii_isxdigit(c)))) { if (use_hex) { dest.append("\\" "x"); - dest.push_back(kHexChar[c / 16]); - dest.push_back(kHexChar[c % 16]); + dest.push_back(numbers_internal::kHexChar[c / 16]); + dest.push_back(numbers_internal::kHexChar[c % 16]); is_hex_escape = true; } else { dest.append("\\"); - dest.push_back(kHexChar[c / 64]); - dest.push_back(kHexChar[(c % 64) / 8]); - dest.push_back(kHexChar[c % 8]); + dest.push_back(numbers_internal::kHexChar[c / 64]); + dest.push_back(numbers_internal::kHexChar[(c % 64) / 8]); + dest.push_back(numbers_internal::kHexChar[c % 8]); } } else { dest.push_back(c); @@ -1019,7 +998,7 @@ template void BytesToHexStringInternal(const unsigned char* src, T dest, ptrdiff_t num) { auto dest_ptr = &dest[0]; for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr, dest_ptr += 2) { - const char* hex_p = &kHexTable[*src_ptr * 2]; + const char* hex_p = &numbers_internal::kHexTable[*src_ptr * 2]; std::copy(hex_p, hex_p + 2, dest_ptr); } } diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc index 38d14869..d7b94fc1 100644 --- a/absl/strings/numbers.cc +++ b/absl/strings/numbers.cc @@ -19,8 +19,8 @@ #include #include -#include // for DBL_DIG and FLT_DIG -#include // for HUGE_VAL +#include // for DBL_DIG and FLT_DIG +#include // for HUGE_VAL #include #include #include @@ -34,6 +34,7 @@ #include "absl/base/internal/raw_logging.h" #include "absl/strings/ascii.h" #include "absl/strings/charconv.h" +#include "absl/strings/escaping.h" #include "absl/strings/internal/memutil.h" #include "absl/strings/match.h" #include "absl/strings/str_cat.h" @@ -885,6 +886,28 @@ inline bool safe_uint_internal(absl::string_view text, IntType* value_p, } // anonymous namespace namespace numbers_internal { + +// Digit conversion. +ABSL_CONST_INIT const char kHexChar[] = "0123456789abcdef"; + +ABSL_CONST_INIT const char kHexTable[513] = + "000102030405060708090a0b0c0d0e0f" + "101112131415161718191a1b1c1d1e1f" + "202122232425262728292a2b2c2d2e2f" + "303132333435363738393a3b3c3d3e3f" + "404142434445464748494a4b4c4d4e4f" + "505152535455565758595a5b5c5d5e5f" + "606162636465666768696a6b6c6d6e6f" + "707172737475767778797a7b7c7d7e7f" + "808182838485868788898a8b8c8d8e8f" + "909192939495969798999a9b9c9d9e9f" + "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf" + "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf" + "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf" + "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf" + "e0e1e2e3e4e5e6e7e8e9eaebecedeeef" + "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"; + bool safe_strto32_base(absl::string_view text, int32_t* value, int base) { return safe_int_internal(text, value, base); } @@ -900,6 +923,6 @@ bool safe_strtou32_base(absl::string_view text, uint32_t* value, int base) { bool safe_strtou64_base(absl::string_view text, uint64_t* value, int base) { return safe_uint_internal(text, value, base); } -} // namespace numbers_internal +} // namespace numbers_internal } // namespace absl diff --git a/absl/strings/numbers.h b/absl/strings/numbers.h index 100839b0..745de67a 100644 --- a/absl/strings/numbers.h +++ b/absl/strings/numbers.h @@ -24,6 +24,10 @@ #ifndef ABSL_STRINGS_NUMBERS_H_ #define ABSL_STRINGS_NUMBERS_H_ +#ifdef __SSE4_2__ +#include +#endif + #include #include #include @@ -32,6 +36,8 @@ #include #include +#include "absl/base/internal/bits.h" +#include "absl/base/internal/endian.h" #include "absl/base/macros.h" #include "absl/base/port.h" #include "absl/numeric/int128.h" @@ -54,7 +60,8 @@ ABSL_MUST_USE_RESULT bool SimpleAtoi(absl::string_view str, int_type* out); // Converts the given string (optionally followed or preceded by ASCII // whitespace) into a float, which may be rounded on overflow or underflow. // See https://en.cppreference.com/w/c/string/byte/strtof for details about the -// allowed formats for `str`. If any errors are encountered, this function +// allowed formats for `str`, except SimpleAtof() is locale-indepdent and will +// always use the "C" locale. If any errors are encountered, this function // returns `false`, leaving `out` in an unspecified state. ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* out); @@ -63,7 +70,8 @@ ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* out); // Converts the given string (optionally followed or preceded by ASCII // whitespace) into a double, which may be rounded on overflow or underflow. // See https://en.cppreference.com/w/c/string/byte/strtof for details about the -// allowed formats for `str`. If any errors are encountered, this function +// allowed formats for `str`, except SimpleAtod is locale-independent and will +// always use the "C" locale. If any errors are encountered, this function // returns `false`, leaving `out` in an unspecified state. ABSL_MUST_USE_RESULT bool SimpleAtod(absl::string_view str, double* out); @@ -84,6 +92,10 @@ ABSL_MUST_USE_RESULT bool SimpleAtob(absl::string_view str, bool* out); namespace absl { namespace numbers_internal { +// Digit conversion. +extern const char kHexChar[17]; // 0123456789abcdef +extern const char kHexTable[513]; // 000102030405060708090a0b0c0d0e0f1011... + // safe_strto?() functions for implementing SimpleAtoi() bool safe_strto32_base(absl::string_view text, int32_t* value, int base); bool safe_strto64_base(absl::string_view text, int64_t* value, int base); @@ -170,6 +182,35 @@ ABSL_MUST_USE_RESULT bool safe_strtoi_base(absl::string_view s, int_type* out, return parsed; } +// FastHexToBufferZeroPad16() +// +// Outputs `val` into `out` as if by `snprintf(out, 17, "%016x", val)` but +// without the terminating null character. Thus `out` must be of length >= 16. +// Returns the number of non-pad digits of the output (it can never be zero +// since 0 has one digit). +inline size_t FastHexToBufferZeroPad16(uint64_t val, char* out) { + uint64_t be = absl::big_endian::FromHost64(val); +#ifdef __SSE4_2__ + const auto kNibbleMask = _mm_set1_epi8(0xf); + const auto kHexDigits = _mm_setr_epi8('0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'); + auto v = _mm_loadu_si64(reinterpret_cast<__m128i*>(&be)); // load lo dword + auto v4 = _mm_srli_epi64(v, 4); // shift 4 right + auto il = _mm_unpacklo_epi8(v4, v); // interleave bytes + auto m = _mm_and_si128(il, kNibbleMask); // mask out nibbles + auto hexchars = _mm_shuffle_epi8(kHexDigits, m); // hex chars + _mm_storeu_si128(reinterpret_cast<__m128i*>(out), hexchars); +#else + for (int i = 0; i < 8; ++i) { + auto byte = (be >> (8 * i)) & 0xFF; + auto* hex = &absl::numbers_internal::kHexTable[byte * 2]; + std::memcpy(out + 2 * i, hex, 2); + } +#endif + // | 0x1 so that even 0 has 1 digit. + return 16 - absl::base_internal::CountLeadingZeros64(val | 0x1) / 4; +} + } // namespace numbers_internal // SimpleAtoi() diff --git a/absl/strings/numbers_benchmark.cc b/absl/strings/numbers_benchmark.cc index 54dbedd3..6e79b3e8 100644 --- a/absl/strings/numbers_benchmark.cc +++ b/absl/strings/numbers_benchmark.cc @@ -20,6 +20,8 @@ #include "benchmark/benchmark.h" #include "absl/base/internal/raw_logging.h" +#include "absl/random/distributions.h" +#include "absl/random/random.h" #include "absl/strings/numbers.h" namespace { @@ -260,4 +262,25 @@ BENCHMARK_TEMPLATE(BM_SimpleAtod, std::string) ->ArgPair(10, 4) ->ArgPair(10, 8); +void BM_FastHexToBufferZeroPad16(benchmark::State& state) { + absl::BitGen rng; + std::vector nums; + nums.resize(1000); + auto min = std::numeric_limits::min(); + auto max = std::numeric_limits::max(); + for (auto& num : nums) { + num = absl::LogUniform(rng, min, max); + } + + char buf[16]; + while (state.KeepRunningBatch(nums.size())) { + for (auto num : nums) { + auto digits = absl::numbers_internal::FastHexToBufferZeroPad16(num, buf); + benchmark::DoNotOptimize(digits); + benchmark::DoNotOptimize(buf); + } + } +} +BENCHMARK(BM_FastHexToBufferZeroPad16); + } // namespace diff --git a/absl/strings/numbers_test.cc b/absl/strings/numbers_test.cc index d964e562..b92b9a8c 100644 --- a/absl/strings/numbers_test.cc +++ b/absl/strings/numbers_test.cc @@ -17,6 +17,7 @@ #include "absl/strings/numbers.h" #include + #include // NOLINT(build/c++11) #include #include @@ -36,10 +37,11 @@ #include "gmock/gmock.h" #include "gtest/gtest.h" #include "absl/base/internal/raw_logging.h" -#include "absl/strings/str_cat.h" - +#include "absl/random/distributions.h" +#include "absl/random/random.h" #include "absl/strings/internal/numbers_test_common.h" #include "absl/strings/internal/pow10_helper.h" +#include "absl/strings/str_cat.h" namespace { @@ -1187,4 +1189,28 @@ TEST(StrToUint64Base, PrefixOnly) { } } +void TestFastHexToBufferZeroPad16(uint64_t v) { + char buf[16]; + auto digits = absl::numbers_internal::FastHexToBufferZeroPad16(v, buf); + absl::string_view res(buf, 16); + char buf2[17]; + snprintf(buf2, sizeof(buf2), "%016" PRIx64, v); + EXPECT_EQ(res, buf2) << v; + size_t expected_digits = snprintf(buf2, sizeof(buf2), "%" PRIx64, v); + EXPECT_EQ(digits, expected_digits) << v; +} + +TEST(FastHexToBufferZeroPad16, Smoke) { + TestFastHexToBufferZeroPad16(std::numeric_limits::min()); + TestFastHexToBufferZeroPad16(std::numeric_limits::max()); + TestFastHexToBufferZeroPad16(std::numeric_limits::min()); + TestFastHexToBufferZeroPad16(std::numeric_limits::max()); + absl::BitGen rng; + for (int i = 0; i < 100000; ++i) { + TestFastHexToBufferZeroPad16( + absl::LogUniform(rng, std::numeric_limits::min(), + std::numeric_limits::max())); + } +} + } // namespace diff --git a/absl/strings/str_cat.cc b/absl/strings/str_cat.cc index 99619445..d5877899 100644 --- a/absl/strings/str_cat.cc +++ b/absl/strings/str_cat.cc @@ -15,12 +15,14 @@ #include "absl/strings/str_cat.h" #include + #include #include #include #include "absl/strings/ascii.h" #include "absl/strings/internal/resize_uninitialized.h" +#include "absl/strings/numbers.h" namespace absl { @@ -28,9 +30,8 @@ AlphaNum::AlphaNum(Hex hex) { char* const end = &digits_[numbers_internal::kFastToBufferSize]; char* writer = end; uint64_t value = hex.value; - static const char hexdigits[] = "0123456789abcdef"; do { - *--writer = hexdigits[value & 0xF]; + *--writer = absl::numbers_internal::kHexChar[value & 0xF]; value >>= 4; } while (value != 0); diff --git a/absl/strings/substitute.cc b/absl/strings/substitute.cc index bc176950..36dbfe7d 100644 --- a/absl/strings/substitute.cc +++ b/absl/strings/substitute.cc @@ -94,7 +94,6 @@ void SubstituteAndAppendArray(std::string* output, absl::string_view format, assert(target == output->data() + output->size()); } -static const char kHexDigits[] = "0123456789abcdef"; Arg::Arg(const void* value) { static_assert(sizeof(scratch_) >= sizeof(value) * 2 + 2, "fix sizeof(scratch_)"); @@ -104,7 +103,7 @@ Arg::Arg(const void* value) { char* ptr = scratch_ + sizeof(scratch_); uintptr_t num = reinterpret_cast(value); do { - *--ptr = kHexDigits[num & 0xf]; + *--ptr = absl::numbers_internal::kHexChar[num & 0xf]; num >>= 4; } while (num != 0); *--ptr = 'x'; @@ -119,7 +118,7 @@ Arg::Arg(Hex hex) { char* writer = end; uint64_t value = hex.value; do { - *--writer = kHexDigits[value & 0xF]; + *--writer = absl::numbers_internal::kHexChar[value & 0xF]; value >>= 4; } while (value != 0); diff --git a/ci/linux_gcc_alpine_cmake.sh b/ci/linux_gcc_alpine_cmake.sh new file mode 100755 index 00000000..830a1360 --- /dev/null +++ b/ci/linux_gcc_alpine_cmake.sh @@ -0,0 +1,63 @@ +#!/bin/bash +# +# Copyright 2019 The Abseil Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# https://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# TODO(absl-team): This script isn't fully hermetic because +# -DABSL_USE_GOOGLETEST_HEAD=ON means that this script isn't pinned to a fixed +# version of GoogleTest. This means that an upstream change to GoogleTest could +# break this test. Fix this by allowing this script to pin to a known-good +# version of GoogleTest. + +set -euox pipefail + +if [ -z ${ABSEIL_ROOT:-} ]; then + ABSEIL_ROOT="$(realpath $(dirname ${0})/..)" +fi + +if [ -z ${ABSL_CMAKE_CXX_STANDARDS:-} ]; then + ABSL_CMAKE_CXX_STANDARDS="11 14 17" +fi + +if [ -z ${ABSL_CMAKE_BUILD_TYPES:-} ]; then + ABSL_CMAKE_BUILD_TYPES="Debug Release" +fi + +readonly DOCKER_CONTAINER="gcr.io/google.com/absl-177019/alpine:20191016" + +for std in ${ABSL_CMAKE_CXX_STANDARDS}; do + for compilation_mode in ${ABSL_CMAKE_BUILD_TYPES}; do + echo "--------------------------------------------------------------------" + echo "Testing with CMAKE_BUILD_TYPE=${compilation_mode} and -std=c++${std}" + + time docker run \ + --volume="${ABSEIL_ROOT}:/abseil-cpp:ro" \ + --workdir=/abseil-cpp \ + --tmpfs=/buildfs:exec \ + --cap-add=SYS_PTRACE \ + --rm \ + -e CFLAGS="-Werror" \ + -e CXXFLAGS="-Werror" \ + "${DOCKER_CONTAINER}" \ + /bin/sh -c " + cd /buildfs && \ + cmake /abseil-cpp \ + -DABSL_USE_GOOGLETEST_HEAD=ON \ + -DABSL_RUN_TESTS=ON \ + -DCMAKE_BUILD_TYPE=${compilation_mode} \ + -DCMAKE_CXX_STANDARD=${std} && \ + make -j$(nproc) && \ + ctest -j$(nproc) --output-on-failure" + done +done