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- /*
- * Copyright 2013-present Facebook, Inc.
- *
- * 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
- *
- * http://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.
- */
- #pragma once
- #include <errno.h>
- #include <cstdio>
- #include <stdexcept>
- #include <system_error>
- #include <folly/Conv.h>
- #include <folly/FBString.h>
- #include <folly/Likely.h>
- #include <folly/Portability.h>
- namespace folly {
- // Various helpers to throw appropriate std::system_error exceptions from C
- // library errors (returned in errno, as positive return values (many POSIX
- // functions), or as negative return values (Linux syscalls))
- //
- // The *Explicit functions take an explicit value for errno.
- inline std::system_error makeSystemErrorExplicit(int err, const char* msg) {
- // TODO: The C++ standard indicates that std::generic_category() should be
- // used for POSIX errno codes.
- //
- // We should ideally change this to use std::generic_category() instead of
- // std::system_category(). However, undertaking this change will require
- // updating existing call sites that currently catch exceptions thrown by
- // this code and currently expect std::system_category.
- return std::system_error(err, std::system_category(), msg);
- }
- template <class... Args>
- std::system_error makeSystemErrorExplicit(int err, Args&&... args) {
- return makeSystemErrorExplicit(
- err, to<fbstring>(std::forward<Args>(args)...).c_str());
- }
- inline std::system_error makeSystemError(const char* msg) {
- return makeSystemErrorExplicit(errno, msg);
- }
- template <class... Args>
- std::system_error makeSystemError(Args&&... args) {
- return makeSystemErrorExplicit(errno, std::forward<Args>(args)...);
- }
- // Helper to throw std::system_error
- [[noreturn]] inline void throwSystemErrorExplicit(int err, const char* msg) {
- throw makeSystemErrorExplicit(err, msg);
- }
- template <class... Args>
- [[noreturn]] void throwSystemErrorExplicit(int err, Args&&... args) {
- throw makeSystemErrorExplicit(err, std::forward<Args>(args)...);
- }
- // Helper to throw std::system_error from errno and components of a string
- template <class... Args>
- [[noreturn]] void throwSystemError(Args&&... args) {
- throwSystemErrorExplicit(errno, std::forward<Args>(args)...);
- }
- // Check a Posix return code (0 on success, error number on error), throw
- // on error.
- template <class... Args>
- void checkPosixError(int err, Args&&... args) {
- if (UNLIKELY(err != 0)) {
- throwSystemErrorExplicit(err, std::forward<Args>(args)...);
- }
- }
- // Check a Linux kernel-style return code (>= 0 on success, negative error
- // number on error), throw on error.
- template <class... Args>
- void checkKernelError(ssize_t ret, Args&&... args) {
- if (UNLIKELY(ret < 0)) {
- throwSystemErrorExplicit(int(-ret), std::forward<Args>(args)...);
- }
- }
- // Check a traditional Unix return code (-1 and sets errno on error), throw
- // on error.
- template <class... Args>
- void checkUnixError(ssize_t ret, Args&&... args) {
- if (UNLIKELY(ret == -1)) {
- throwSystemError(std::forward<Args>(args)...);
- }
- }
- template <class... Args>
- void checkUnixErrorExplicit(ssize_t ret, int savedErrno, Args&&... args) {
- if (UNLIKELY(ret == -1)) {
- throwSystemErrorExplicit(savedErrno, std::forward<Args>(args)...);
- }
- }
- // Check the return code from a fopen-style function (returns a non-nullptr
- // FILE* on success, nullptr on error, sets errno). Works with fopen, fdopen,
- // freopen, tmpfile, etc.
- template <class... Args>
- void checkFopenError(FILE* fp, Args&&... args) {
- if (UNLIKELY(!fp)) {
- throwSystemError(std::forward<Args>(args)...);
- }
- }
- template <class... Args>
- void checkFopenErrorExplicit(FILE* fp, int savedErrno, Args&&... args) {
- if (UNLIKELY(!fp)) {
- throwSystemErrorExplicit(savedErrno, std::forward<Args>(args)...);
- }
- }
- /**
- * If cond is not true, raise an exception of type E. E must have a ctor that
- * works with const char* (a description of the failure).
- */
- #define CHECK_THROW(cond, E) \
- do { \
- if (!(cond)) { \
- throw E("Check failed: " #cond); \
- } \
- } while (0)
- } // namespace folly
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