src/base/logging.hh

/*
 * Copyright (c) 2014, 2017 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
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Nathan Binkert
 *          Dave Greene
 *          Andreas Sandberg
 */

#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)

/**
 * This implements a cprintf based panic() function.  panic() should
 * be called when something happens that should never ever happen
 * regardless of what the user does (i.e., an acutal m5 bug).  panic()
 * might call abort which can dump core or enter the debugger.
 */
#define panic(...) exit_message(::Logger::getPanic(), __VA_ARGS__)

/**
 * This implements a cprintf based fatal() function.  fatal() should
 * be called when the simulation cannot continue due to some condition
 * that is the user's fault (bad configuration, invalid arguments,
 * etc.) and not a simulator bug.  fatal() might call exit, unlike panic().
 */
#define fatal(...) exit_message(::Logger::getFatal(), __VA_ARGS__)

/**
 * Conditional panic macro that checks the supplied condition and only panics
 * if the condition is true and allows the programmer to specify diagnostic
 * printout.  Useful to replace if + panic, or if + print + assert, etc.
 *
 * @param cond Condition that is checked; if true -> panic
 * @param ...  Printf-based format string with arguments, extends printout.
 */
#define panic_if(cond, ...)                                  \
    do {                                                     \
        if ((cond)) {                                        \
            panic("panic condition " # cond " occurred: %s", \
                  csprintf(__VA_ARGS__));                    \
        }                                                    \
    } while (0)


/**
 * Conditional fatal macro that checks the supplied condition and only causes a
 * fatal error if the condition is true and allows the programmer to specify
 * diagnostic printout.  Useful to replace if + fatal, or if + print + assert,
 * etc.
 *
 * @param cond Condition that is checked; if true -> fatal
 * @param ...  Printf-based format string with arguments, extends printout.
 */
#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__)

/**
 * Conditional warning macro that checks the supplied condition and
 * only prints a warning if the condition is true. Useful to replace
 * if + warn.
 *
 * @param cond Condition that is checked; if true -> warn
 * @param ...  Printf-based format string with arguments, extends printout.
 */
#define warn_if(cond, ...) \
    do { \
        if ((cond)) \
            warn(__VA_ARGS__); \
    } while (0)

/**
 * The chatty assert macro will function like a normal assert, but will allow
 * the specification of additional, helpful material to aid debugging why the
 * assertion actually failed.  Like the normal assertion, the chatty_assert
 * will not be active in fast builds.
 *
 * @param cond Condition that is checked; if false -> assert
 * @param ...  Printf-based format string with arguments, extends printout.
 */
#ifdef NDEBUG
#define chatty_assert(cond, ...)
#else //!NDEBUG
#define chatty_assert(cond, ...)                                        \
    do {                                                                \
        if (!(cond))                                                    \
            panic("assert(" # cond ") failed: %s", csprintf(__VA_ARGS__)); \
    } while (0)
#endif // NDEBUG
#endif // __BASE_LOGGING_HH__