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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#ifndef mozilla_SandboxLogging_h
#define mozilla_SandboxLogging_h
// This header defines the SANDBOX_LOG macro used in the Linux
// sandboxing code. It uses Android logging on Android and writes to
// stderr otherwise. Android logging has severity levels; currently
// only "error" severity is exposed here, and this isn't marked when
// writing to stderr.
//
// The format strings are processed by Chromium SafeSPrintf, which
// doesn't accept size modifiers or %u because it uses C++11 variadic
// templates to obtain the actual argument types; all decimal integer
// formatting uses %d. See safe_sprintf.h for more details.
// Build SafeSPrintf without assertions to avoid a dependency on
// Chromium logging. This doesn't affect safety; it just means that
// type mismatches (pointer vs. integer) always result in unexpanded
// %-directives instead of crashing. See also the moz.build files,
// which apply NDEBUG to the .cc file.
#ifndef NDEBUG
# define NDEBUG 1
# include "base/strings/safe_sprintf.h"
# undef NDEBUG
#else
# include "base/strings/safe_sprintf.h"
#endif
#include <errno.h>
namespace mozilla {
// Logs the formatted string (marked with "error" severity, if supported).
void SandboxLogError(const char* aMessage);
// Writes into aBuf the identifier for an error number (e.g., "EINVAL"
// rather than "Invalid argument"); may fall back to "error N" (with
// the number) for unhandled errors.
//
// Bounds are handled like snprintf: the return value is the length
// the string would have (not counting the null terminator) ignoring
// buffer size, and the string written into the buffer may be
// truncated to fit but is always null terminated.
ssize_t GetLibcErrorName(char* aBuf, size_t aSize, int aErr);
} // namespace mozilla
#define SANDBOX_LOG_LEN 256
// Formats a log message and logs it (with "error" severity, if supported).
//
// Note that SafeSPrintf doesn't accept size modifiers or %u; all
// decimal integers are %d, because it uses C++11 variadic templates
// to use the actual argument type.
#define SANDBOX_LOG(fmt, args...) \
do { \
char _sandboxLogBuf[SANDBOX_LOG_LEN]; \
::base::strings::SafeSPrintf(_sandboxLogBuf, fmt, ##args); \
::mozilla::SandboxLogError(_sandboxLogBuf); \
} while (0)
#define SANDBOX_LOG_WITH_ERROR(errnum, fmt, args...) \
do { \
char _sandboxLogBuf[SANDBOX_LOG_LEN]; \
ssize_t _sandboxLogOff = \
::base::strings::SafeSPrintf(_sandboxLogBuf, fmt ": ", ##args); \
if (static_cast<size_t>(_sandboxLogOff) < sizeof(_sandboxLogBuf)) { \
::mozilla::GetLibcErrorName(_sandboxLogBuf + _sandboxLogOff, \
sizeof(_sandboxLogBuf) - _sandboxLogOff, \
errnum); \
} \
::mozilla::SandboxLogError(_sandboxLogBuf); \
} while (0)
#define SANDBOX_LOG_ERRNO(fmt, args...) \
SANDBOX_LOG_WITH_ERROR(errno, fmt, ##args)
#endif // mozilla_SandboxLogging_h