logging.hh

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/*
 * Copyright (c) 2014, 2017, 2019 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Copyright (c) 2002-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
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 * neither the name of the copyright holders nor the names of its
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 */

#ifndef __BASE_LOGGING_HH__
#define __BASE_LOGGING_HH__

#include <cassert>
#include <sstream>
#include <utility>

#include "base/compiler.hh"
#include "base/cprintf.hh"

class Logger
{
  public:

    // Get a Logger for the specified type of message.
    static Logger &getPanic();
    static Logger &getFatal();
    static Logger &getWarn();
    static Logger &getInfo();
    static Logger &getHack();

    enum LogLevel {
        PANIC, FATAL, WARN, INFO, HACK,
        NUM_LOG_LEVELS,
    };

    static void
    setLevel(LogLevel ll)
    {
        getPanic().enabled = (ll >= PANIC);
        getFatal().enabled = (ll >= FATAL);
        getWarn().enabled = (ll >= WARN);
        getInfo().enabled = (ll >= INFO);
        getHack().enabled = (ll >= HACK);
    }

    struct Loc
    {
        Loc(const char *file, int line) : file(file), line(line) {}
        const char *file;
        int line;
    };

    Logger(const char *prefix) : enabled(true), prefix(prefix)
    {
        assert(prefix);
    }

    virtual ~Logger() {};

    void
    print(const Loc &loc, const std::string &str)
    {
        std::stringstream ss;
        ss << prefix << str;
        if (str.length() && str.back() != '\n' && str.back() != '\r')
            ss << std::endl;
        if (!enabled)
            return;
        log(loc, ss.str());
    }

    template<typename ...Args> void
    print(const Loc &loc, const char *format, const Args &...args)
    {
        std::stringstream ss;
        ccprintf(ss, format, args...);
        print(loc, ss.str());
    }

    template<typename ...Args> void
    print(const Loc &loc, const std::string &format, const Args &...args)
    {
        print(loc, format.c_str(), args...);
    }

    // This helper is necessary since noreturn isn't inherited by virtual
    // functions, and gcc will get mad if a function calls panic and then
    // doesn't return.
    void exit_helper() M5_ATTR_NORETURN { exit(); ::abort(); }

  protected:
    bool enabled;

    virtual void log(const Loc &loc, std::string s) = 0;
    virtual void exit() { /* Fall through to the abort in exit_helper. */ }

    const char *prefix;
};


#define base_message(logger, ...) \
    logger.print(::Logger::Loc(__FILE__, __LINE__), __VA_ARGS__)

/*
 * Only print the message the first time this expression is
 * encountered.  i.e.  This doesn't check the string itself and
 * prevent duplicate strings, this prevents the statement from
 * happening more than once. So, even if the arguments change and that
 * would have resulted in a different message thoes messages would be
 * supressed.
 */
#define base_message_once(...) do {                     \
        static bool once = false;                       \
        if (!once) {                                    \
            base_message(__VA_ARGS__);                  \
            once = true;                                \
        }                                               \
    } while (0)

#define exit_message(logger, ...)                       \
    do {                                                \
        base_message(logger, __VA_ARGS__);              \
        logger.exit_helper();                           \
    } while (0)

#define panic(...) exit_message(::Logger::getPanic(), __VA_ARGS__)

#define fatal(...) exit_message(::Logger::getFatal(), __VA_ARGS__)

#define panic_if(cond, ...)                                  \
    do {                                                     \
        if ((cond)) {                                        \
            panic("panic condition " # cond " occurred: %s", \
                  csprintf(__VA_ARGS__));                    \
        }                                                    \
    } while (0)


#define fatal_if(cond, ...)                                     \
    do {                                                        \
        if ((cond)) {                                           \
            fatal("fatal condition " # cond " occurred: %s",    \
                  csprintf(__VA_ARGS__));                       \
        }                                                       \
    } while (0)


#define warn(...) base_message(::Logger::getWarn(), __VA_ARGS__)
#define inform(...) base_message(::Logger::getInfo(), __VA_ARGS__)
#define hack(...) base_message(::Logger::getHack(), __VA_ARGS__)

#define warn_once(...) base_message_once(::Logger::getWarn(), __VA_ARGS__)
#define inform_once(...) base_message_once(::Logger::getInfo(), __VA_ARGS__)
#define hack_once(...) base_message_once(::Logger::getHack(), __VA_ARGS__)

#define warn_if(cond, ...) \
    do { \
        if ((cond)) \
            warn(__VA_ARGS__); \
    } while (0)

#define warn_if_once(cond, ...) \
    do { \
        if ((cond)) \
            warn_once(__VA_ARGS__); \
    } while (0)

#ifdef NDEBUG
#define chatty_assert(cond, ...)
#else 
#define chatty_assert(cond, ...)                                        \
    do {                                                                \
        if (!(cond))                                                    \
            panic("assert(" # cond ") failed: %s", csprintf(__VA_ARGS__)); \
    } while (0)
#endif // NDEBUG
#endif // __BASE_LOGGING_HH__