path: root/lib/ephy-debug.c

/*
 *  Copyright © 2003 Marco Pesenti Gritti
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"

#include "ephy-debug.h"

#include <string.h>
#ifdef HAVE_EXECINFO_H
#include <execinfo.h>
#endif
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <glib.h>

/**
 * SECTION:ephy-debug
 * @short_description: Epiphany debugging and profiling facilities
 *
 * Epiphany includes powerful profiling and debugging facilities to log and
 * analyze modules. Refer to doc/debugging.txt for more information.
 */

static const char *ephy_debug_break = NULL;

#ifndef DISABLE_PROFILING
static GHashTable *ephy_profilers_hash = NULL;
static char **ephy_profile_modules;
static gboolean ephy_profile_all_modules;
#endif /* !DISABLE_PROFILING */

#ifdef GNOME_ENABLE_DEBUG

static char **
build_modules (const char *name,
           gboolean* is_all)
{
    const char *env;

    *is_all = FALSE;

    env = g_getenv (name);
    if (env == NULL) return NULL;

    if (strcmp (env, "all") == 0)
    {
        *is_all = TRUE;
        return NULL;
    }

    return g_strsplit (g_getenv (name), ":", -1);
}

#endif

#ifndef DISABLE_LOGGING

static char **ephy_log_modules;
static gboolean ephy_log_all_modules;

static void
log_module (const gchar *log_domain,
        GLogLevelFlags log_level,
        const char *message,
        gpointer user_data)
{
    gboolean should_log = ephy_log_all_modules;

    if (!ephy_log_all_modules && !ephy_log_modules) return;

    if (ephy_log_modules != NULL)
    {
        guint i;

        for (i = 0; ephy_log_modules[i] != NULL; i++)
        {
            if (strstr (message, ephy_log_modules [i]) != NULL)
            {
                should_log = TRUE;
                break;
            }
        }
    }

    if (should_log)
    {
        g_print ("%s\n", message);
    }
}

#endif /* !DISABLE_LOGGING */

#define MAX_DEPTH 200

static void 
trap_handler (const char *log_domain,
          GLogLevelFlags log_level,
          const char *message,
          gpointer user_data)
{
    g_log_default_handler (log_domain, log_level, message, user_data);

    if (ephy_debug_break != NULL &&
        (log_level & (G_LOG_LEVEL_WARNING |
              G_LOG_LEVEL_ERROR |
              G_LOG_LEVEL_CRITICAL |
              G_LOG_FLAG_FATAL)))
    {
        if (strcmp (ephy_debug_break, "suspend") == 0)
        {
            /* the suspend case is first because we wanna send the signal before 
             * other threads have had a chance to get too far from the state that
             * caused this assertion (in case they happen to have been involved).
             */
            g_print ("Suspending program; attach with the debugger.\n");

            raise (SIGSTOP);
        }
        else if (strcmp (ephy_debug_break, "stack") == 0)
        {
#ifdef HAVE_EXECINFO_H
            void *array[MAX_DEPTH];
            size_t size;
            
            size = backtrace (array, MAX_DEPTH);
            backtrace_symbols_fd (array, size, 2);
#else
            g_on_error_stack_trace (g_get_prgname ());
#endif /* HAVE_EXECINFO_H */
        }
        else if (strcmp (ephy_debug_break, "trap") == 0)
        {
            /* FIXME: disable the handler for a moment so we 
             * don't crash if we don't actually run under gdb
             */
            G_BREAKPOINT ();
        }
        else if (strcmp (ephy_debug_break, "warn") == 0)
        {
            /* default behaviour only */
        }
        else if (ephy_debug_break[0] != '\0')
        {
            g_print ("Unrecognised value of EPHY_DEBUG_BREAK env var: %s!\n",
                 ephy_debug_break);
        }
    }
}

/**
 * ephy_debug_init:
 *
 * Starts the debugging facility, see doc/debugging.txt in Epiphany's source for
 * more information. It also starts module logging and profiling if the
 * appropiate variables are set: EPHY_LOG_MODULES and EPHY_PROFILE_MODULES.
 **/
void
ephy_debug_init (void)
{
#ifndef DISABLE_LOGGING
    ephy_log_modules = build_modules ("EPHY_LOG_MODULES", &ephy_log_all_modules);

    g_log_set_handler (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, log_module, NULL);

#endif

    ephy_debug_break = g_getenv ("EPHY_DEBUG_BREAK");
    g_log_set_default_handler (trap_handler, NULL);

#ifndef DISABLE_PROFILING
    ephy_profile_modules = build_modules ("EPHY_PROFILE_MODULES", &ephy_profile_all_modules);
#endif
}

#ifndef DISABLE_PROFILING

static EphyProfiler *
ephy_profiler_new (const char *name, const char *module)
{
    EphyProfiler *profiler;

    profiler = g_new0 (EphyProfiler, 1);
    profiler->timer = g_timer_new ();
    profiler->name  = g_strdup (name);
    profiler->module  = g_strdup (module);

    g_timer_start (profiler->timer);

    return profiler;
}

static gboolean
ephy_should_profile (const char *module)
{
    char *slash;
    gboolean result = FALSE;
    guint i;

    slash = strrchr (module, '/');

    /* Happens on builddir != srcdir builds */
    if (slash != NULL) module = slash + 1;

    for (i = 0; ephy_profile_modules[i] != NULL; i++)
    {
        if (strcmp (ephy_profile_modules[i], module) == 0)
        {
            result = TRUE;
            break;
        }
    }

    return result;
}

static void
ephy_profiler_dump (EphyProfiler *profiler)
{
    double seconds;

    g_return_if_fail (profiler != NULL);

    seconds = g_timer_elapsed (profiler->timer, NULL);

    g_print ("[ %s ] %s %f s elapsed\n",
         profiler->module, profiler->name,
         seconds);
}

static void
ephy_profiler_free (EphyProfiler *profiler)
{
    g_return_if_fail (profiler != NULL);

    g_timer_destroy (profiler->timer);
    g_free (profiler->name);
    g_free (profiler->module);
    g_free (profiler);
}

/**
 * ephy_profiler_start:
 * @name: name of this new profiler
 * @module: Epiphany module to profile
 *
 * Starts a new profiler on @module naming it @name.
 **/
void
ephy_profiler_start (const char *name, const char *module)
{
    EphyProfiler *profiler;

    if (ephy_profilers_hash == NULL)
    {
        ephy_profilers_hash =
            g_hash_table_new_full (g_str_hash, g_str_equal,
                           g_free, NULL);
    }

    if (!ephy_profile_all_modules &&
        (ephy_profile_modules == NULL || !ephy_should_profile (module))) return;

    profiler = ephy_profiler_new (name, module);

    g_hash_table_insert (ephy_profilers_hash, g_strdup (name), profiler);
}

/**
 * ephy_profiler_stop:
 * @name: name of the profiler to stop
 *
 * Stops the profiler named @name.
 **/
void
ephy_profiler_stop (const char *name)
{
    EphyProfiler *profiler;

    profiler = g_hash_table_lookup (ephy_profilers_hash, name);
    if (profiler == NULL) return;
    g_hash_table_remove (ephy_profilers_hash, name);

    ephy_profiler_dump (profiler);
    ephy_profiler_free (profiler);
}

#endif