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-rw-r--r--absl/base/BUILD.bazel45
-rw-r--r--absl/base/CMakeLists.txt32
-rw-r--r--absl/base/internal/errno_saver_test.cc3
-rw-r--r--absl/base/internal/strerror.cc75
-rw-r--r--absl/base/internal/strerror.h39
-rw-r--r--absl/base/internal/strerror_benchmark.cc38
-rw-r--r--absl/base/internal/strerror_test.cc86
7 files changed, 317 insertions, 1 deletions
diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index bae79427..24dab791 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -307,6 +307,7 @@ cc_test(
linkopts = ABSL_DEFAULT_LINKOPTS,
deps = [
":errno_saver",
+ ":strerror",
"@com_google_googletest//:gtest_main",
],
)
@@ -451,6 +452,7 @@ cc_binary(
testonly = 1,
copts = ABSL_DEFAULT_COPTS,
linkopts = ABSL_DEFAULT_LINKOPTS,
+ tags = ["benchmark"],
visibility = ["//visibility:private"],
deps = [
":spinlock_benchmark_common",
@@ -705,3 +707,46 @@ cc_test(
"@com_google_googletest//:gtest_main",
],
)
+
+cc_library(
+ name = "strerror",
+ srcs = ["internal/strerror.cc"],
+ hdrs = ["internal/strerror.h"],
+ copts = ABSL_DEFAULT_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ visibility = [
+ "//absl:__subpackages__",
+ ],
+ deps = [
+ ":config",
+ ":core_headers",
+ ":errno_saver",
+ ],
+)
+
+cc_test(
+ name = "strerror_test",
+ size = "small",
+ srcs = ["internal/strerror_test.cc"],
+ copts = ABSL_TEST_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ deps = [
+ ":strerror",
+ "//absl/strings",
+ "@com_google_googletest//:gtest_main",
+ ],
+)
+
+cc_binary(
+ name = "strerror_benchmark",
+ testonly = 1,
+ srcs = ["internal/strerror_benchmark.cc"],
+ copts = ABSL_TEST_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ tags = ["benchmark"],
+ visibility = ["//visibility:private"],
+ deps = [
+ ":strerror",
+ "@com_github_google_benchmark//:benchmark_main",
+ ],
+)
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 14c52eab..4230d2e7 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -326,6 +326,7 @@ absl_cc_test(
${ABSL_TEST_COPTS}
DEPS
absl::errno_saver
+ absl::strerror
gmock
gtest_main
)
@@ -642,3 +643,34 @@ absl_cc_test(
gmock
gtest_main
)
+
+absl_cc_library(
+ NAME
+ strerror
+ SRCS
+ "internal/strerror.cc"
+ HDRS
+ "internal/strerror.h"
+ COPTS
+ ${ABSL_DEFAULT_COPTS}
+ LINKOPTS
+ ${ABSL_DEFAULT_LINKOPTS}
+ DEPS
+ absl::config
+ absl::core_headers
+ absl::errno_saver
+)
+
+absl_cc_test(
+ NAME
+ strerror_test
+ SRCS
+ "internal/strerror_test.cc"
+ COPTS
+ ${ABSL_TEST_COPTS}
+ DEPS
+ absl::strerror
+ absl::strings
+ gmock
+ gtest_main
+)
diff --git a/absl/base/internal/errno_saver_test.cc b/absl/base/internal/errno_saver_test.cc
index b845e2dd..e9b742c5 100644
--- a/absl/base/internal/errno_saver_test.cc
+++ b/absl/base/internal/errno_saver_test.cc
@@ -18,6 +18,7 @@
#include "gmock/gmock.h"
#include "gtest/gtest.h"
+#include "absl/base/internal/strerror.h"
namespace {
using ::testing::Eq;
@@ -26,7 +27,7 @@ struct ErrnoPrinter {
int no;
};
std::ostream &operator<<(std::ostream &os, ErrnoPrinter ep) {
- return os << strerror(ep.no) << " [" << ep.no << "]";
+ return os << absl::base_internal::StrError(ep.no) << " [" << ep.no << "]";
}
bool operator==(ErrnoPrinter one, ErrnoPrinter two) { return one.no == two.no; }
diff --git a/absl/base/internal/strerror.cc b/absl/base/internal/strerror.cc
new file mode 100644
index 00000000..af181513
--- /dev/null
+++ b/absl/base/internal/strerror.cc
@@ -0,0 +1,75 @@
+// Copyright 2020 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/base/internal/strerror.h"
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <cstring>
+#include <string>
+#include <type_traits>
+
+#include "absl/base/attributes.h"
+#include "absl/base/internal/errno_saver.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace base_internal {
+namespace {
+const char* StrErrorAdaptor(int errnum, char* buf, size_t buflen) {
+#if defined(_WIN32)
+ int rc = strerror_s(buf, buflen, errnum);
+ buf[buflen - 1] = '\0'; // guarantee NUL termination
+ if (rc == 0 && strncmp(buf, "Unknown error", buflen) == 0) *buf = '\0';
+ return buf;
+#else
+#if defined(__GLIBC__) || defined(__APPLE__)
+ // Use the BSD sys_errlist API provided by GNU glibc and others to
+ // avoid any need to copy the message into the local buffer first.
+ if (0 <= errnum && errnum < sys_nerr) {
+ if (const char* p = sys_errlist[errnum]) {
+ return p;
+ }
+ }
+#endif
+ // The type of `ret` is platform-specific; both of these branches must compile
+ // either way but only one will execute on any given platform:
+ auto ret = strerror_r(errnum, buf, buflen);
+ if (std::is_same<decltype(ret), int>::value) {
+ // XSI `strerror_r`; `ret` is `int`:
+ if (ret) *buf = '\0';
+ return buf;
+ } else {
+ // GNU `strerror_r`; `ret` is `char *`:
+ return reinterpret_cast<const char*>(ret);
+ }
+#endif
+}
+} // namespace
+
+std::string StrError(int errnum) {
+ absl::base_internal::ErrnoSaver errno_saver;
+ char buf[100];
+ const char* str = StrErrorAdaptor(errnum, buf, sizeof buf);
+ if (*str == '\0') {
+ snprintf(buf, sizeof buf, "Unknown error %d", errnum);
+ str = buf;
+ }
+ return str;
+}
+
+} // namespace base_internal
+ABSL_NAMESPACE_END
+} // namespace absl
diff --git a/absl/base/internal/strerror.h b/absl/base/internal/strerror.h
new file mode 100644
index 00000000..35009736
--- /dev/null
+++ b/absl/base/internal/strerror.h
@@ -0,0 +1,39 @@
+// Copyright 2020 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_BASE_INTERNAL_STRERROR_H_
+#define ABSL_BASE_INTERNAL_STRERROR_H_
+
+#include <string>
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace base_internal {
+
+// A portable and thread-safe alternative to C89's `strerror`.
+//
+// The C89 specification of `strerror` is not suitable for use in a
+// multi-threaded application as the returned string may be changed by calls to
+// `strerror` from another thread. The many non-stdlib alternatives differ
+// enough in their names, availability, and semantics to justify this wrapper
+// around them. `errno` will not be modified by a call to `absl::StrError`.
+std::string StrError(int errnum);
+
+} // namespace base_internal
+ABSL_NAMESPACE_END
+} // namespace absl
+
+#endif // ABSL_BASE_INTERNAL_STRERROR_H_
diff --git a/absl/base/internal/strerror_benchmark.cc b/absl/base/internal/strerror_benchmark.cc
new file mode 100644
index 00000000..d8ca86b9
--- /dev/null
+++ b/absl/base/internal/strerror_benchmark.cc
@@ -0,0 +1,38 @@
+// Copyright 2020 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 <cerrno>
+#include <cstdio>
+#include <string>
+
+#include "absl/base/internal/strerror.h"
+#include "benchmark/benchmark.h"
+
+namespace {
+#if defined(__GLIBC__) || defined(__APPLE__)
+void BM_SysErrList(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::string(sys_errlist[ERANGE]));
+ }
+}
+BENCHMARK(BM_SysErrList);
+#endif
+
+void BM_AbslStrError(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::base_internal::StrError(ERANGE));
+ }
+}
+BENCHMARK(BM_AbslStrError);
+} // namespace
diff --git a/absl/base/internal/strerror_test.cc b/absl/base/internal/strerror_test.cc
new file mode 100644
index 00000000..a53da97f
--- /dev/null
+++ b/absl/base/internal/strerror_test.cc
@@ -0,0 +1,86 @@
+// Copyright 2020 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/base/internal/strerror.h"
+
+#include <atomic>
+#include <cerrno>
+#include <cstdio>
+#include <cstring>
+#include <string>
+#include <thread> // NOLINT(build/c++11)
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/strings/match.h"
+
+namespace {
+using ::testing::AnyOf;
+using ::testing::Eq;
+
+TEST(StrErrorTest, ValidErrorCode) {
+ errno = ERANGE;
+ EXPECT_THAT(absl::base_internal::StrError(EDOM), Eq(strerror(EDOM)));
+ EXPECT_THAT(errno, Eq(ERANGE));
+}
+
+TEST(StrErrorTest, InvalidErrorCode) {
+ errno = ERANGE;
+ EXPECT_THAT(absl::base_internal::StrError(-1),
+ AnyOf(Eq("No error information"), Eq("Unknown error -1")));
+ EXPECT_THAT(errno, Eq(ERANGE));
+}
+
+TEST(StrErrorTest, MultipleThreads) {
+ // In this test, we will start up 2 threads and have each one call
+ // StrError 1000 times, each time with a different errnum. We
+ // expect that StrError(errnum) will return a string equal to the
+ // one returned by strerror(errnum), if the code is known. Since
+ // strerror is known to be thread-hostile, collect all the expected
+ // strings up front.
+ const int kNumCodes = 1000;
+ std::vector<std::string> expected_strings(kNumCodes);
+ for (int i = 0; i < kNumCodes; ++i) {
+ expected_strings[i] = strerror(i);
+ }
+
+ std::atomic_int counter(0);
+ auto thread_fun = [&]() {
+ for (int i = 0; i < kNumCodes; ++i) {
+ ++counter;
+ errno = ERANGE;
+ const std::string value = absl::base_internal::StrError(i);
+ // Only the GNU implementation is guaranteed to provide the
+ // string "Unknown error nnn". POSIX doesn't say anything.
+ if (!absl::StartsWith(value, "Unknown error ")) {
+ EXPECT_THAT(absl::base_internal::StrError(i), Eq(expected_strings[i]));
+ }
+ EXPECT_THAT(errno, Eq(ERANGE));
+ }
+ };
+
+ const int kNumThreads = 100;
+ std::vector<std::thread> threads;
+ for (int i = 0; i < kNumThreads; ++i) {
+ threads.push_back(std::thread(thread_fun));
+ }
+ for (auto& thread : threads) {
+ thread.join();
+ }
+
+ EXPECT_THAT(counter, Eq(kNumThreads * kNumCodes));
+}
+
+} // namespace
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 07:33:56 +0000