gecko-dev/mozglue/linker/Logging.h

/* 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 Logging_h
#define Logging_h

#include <cstdlib>
#include "mozilla/Likely.h"
#include "mozilla/MacroArgs.h"

#ifdef ANDROID
#  include <android/log.h>
#  define LOG(...) \
    __android_log_print(ANDROID_LOG_INFO, "GeckoLinker", __VA_ARGS__)
#  define WARN(...) \
    __android_log_print(ANDROID_LOG_WARN, "GeckoLinker", __VA_ARGS__)
#  define ERROR(...) \
    __android_log_print(ANDROID_LOG_ERROR, "GeckoLinker", __VA_ARGS__)
#else
#  include <cstdio>

/* Expand to 1 or m depending on whether there is one argument or more
 * given. */
#  define MOZ_ONE_OR_MORE_ARGS_IMPL2(_1, _2, _3, _4, _5, _6, _7, _8, _9, N, \
                                     ...)                                   \
    N
#  define MOZ_ONE_OR_MORE_ARGS_IMPL(args) MOZ_ONE_OR_MORE_ARGS_IMPL2 args
#  define MOZ_ONE_OR_MORE_ARGS(...) \
    MOZ_ONE_OR_MORE_ARGS_IMPL((__VA_ARGS__, m, m, m, m, m, m, m, m, 1, 0))

#  define MOZ_MACRO_GLUE(a, b) a b

/* Some magic to choose between LOG1 and LOGm depending on the number of
 * arguments */
#  define MOZ_CHOOSE_LOG(...)                                          \
    MOZ_MACRO_GLUE(MOZ_CONCAT(LOG, MOZ_ONE_OR_MORE_ARGS(__VA_ARGS__)), \
                   (__VA_ARGS__))

#  define LOG1(format) fprintf(stderr, format "\n")
#  define LOGm(format, ...) fprintf(stderr, format "\n", __VA_ARGS__)
#  define LOG(...) MOZ_CHOOSE_LOG(__VA_ARGS__)
#  define WARN(...) MOZ_CHOOSE_LOG("Warning: " __VA_ARGS__)
#  define ERROR(...) MOZ_CHOOSE_LOG("Error: " __VA_ARGS__)

#endif

class Logging {
 public:
  static bool isVerbose() { return Singleton.verbose; }

 private:
  bool verbose;

 public:
  static void Init() {
    const char* env = getenv("MOZ_DEBUG_LINKER");
    if (env && *env == '1') Singleton.verbose = true;
  }

 private:
  static Logging Singleton;
};

#define DEBUG_LOG(...)                        \
  do {                                        \
    if (MOZ_UNLIKELY(Logging::isVerbose())) { \
      LOG(__VA_ARGS__);                       \
    }                                         \
  } while (0)

#endif /* Logging_h */