security/sandbox/linux/SandboxLogging.h
author Nicolas Silva <nsilva@mozilla.com>
Thu, 14 Feb 2019 13:40:51 +0000
changeset 459125 e23608ddeac0b5e92b728965031796ded09dc8f2
parent 454520 5f4630838d46dd81dadb13220a4af0da9e23a619
permissions -rw-r--r--
Bug 1527884 - WebRender version 0.60.0. r=emilio Differential Revision: https://phabricator.services.mozilla.com/D19780

/* -*- 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,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_SandboxLogging_h
#define mozilla_SandboxLogging_h

// This header defines the SANDBOX_LOG_ERROR 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

namespace mozilla {
// Logs the formatted string (marked with "error" severity, if supported).
void SandboxLogError(const char* aMessage);
}  // 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_ERROR(fmt, args...)                        \
  do {                                                         \
    char _sandboxLogBuf[SANDBOX_LOG_LEN];                      \
    ::base::strings::SafeSPrintf(_sandboxLogBuf, fmt, ##args); \
    ::mozilla::SandboxLogError(_sandboxLogBuf);                \
  } while (0)

#endif  // mozilla_SandboxLogging_h