Abseil Common Libraries (C++) (grcp 依赖)
https://abseil.io/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
88 lines
2.6 KiB
88 lines
2.6 KiB
// 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 <array> |
|
#include <cerrno> |
|
#include <cstddef> |
|
#include <cstdio> |
|
#include <cstring> |
|
#include <string> |
|
#include <type_traits> |
|
|
|
#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 |
|
// 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 |
|
} |
|
|
|
std::string StrErrorInternal(int errnum) { |
|
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; |
|
} |
|
|
|
// kSysNerr is the number of errors from a recent glibc. `StrError()` falls back |
|
// to `StrErrorAdaptor()` if the value is larger than this. |
|
constexpr int kSysNerr = 135; |
|
|
|
std::array<std::string, kSysNerr>* NewStrErrorTable() { |
|
auto* table = new std::array<std::string, kSysNerr>; |
|
for (size_t i = 0; i < table->size(); ++i) { |
|
(*table)[i] = StrErrorInternal(static_cast<int>(i)); |
|
} |
|
return table; |
|
} |
|
|
|
} // namespace |
|
|
|
std::string StrError(int errnum) { |
|
absl::base_internal::ErrnoSaver errno_saver; |
|
static const auto* table = NewStrErrorTable(); |
|
if (errnum >= 0 && static_cast<size_t>(errnum) < table->size()) { |
|
return (*table)[static_cast<size_t>(errnum)]; |
|
} |
|
return StrErrorInternal(errnum); |
|
} |
|
|
|
} // namespace base_internal |
|
ABSL_NAMESPACE_END |
|
} // namespace absl
|
|
|