glib/glib-init.c

   1 /*
   2  * Copyright © 2011 Canonical Limited
   3  *
   4  * This library is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * licence, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  *
  19  * Author: Ryan Lortie <desrt@desrt.ca>
  20  */
  21
  22 #include "config.h"
  23
  24 #include "glib-init.h"
  25
  26 #include "gutils.h"     /* for GDebugKey */
  27
  28 #include <string.h>
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <ctype.h>
  32
  33 /**
  34  * g_mem_gc_friendly:
  35  *
  36  * This variable is %TRUE if the <envar>G_DEBUG</envar> environment variable
  37  * includes the key <literal>gc-friendly</literal>.
  38  */
  39 #ifdef ENABLE_GC_FRIENDLY_DEFAULT
  40 gboolean g_mem_gc_friendly = TRUE;
  41 #else
  42 gboolean g_mem_gc_friendly = FALSE;
  43 #endif
  44 GLogLevelFlags g_log_msg_prefix = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_WARNING |
  45                                   G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_DEBUG;
  46 GLogLevelFlags g_log_always_fatal = G_LOG_FATAL_MASK;
  47
  48 static gboolean
  49 debug_key_matches (const gchar *key,
  50                    const gchar *token,
  51                    guint        length)
  52 {
  53   /* may not call GLib functions: see note in g_parse_debug_string() */
  54   for (; length; length--, key++, token++)
  55     {
  56       char k = (*key   == '_') ? '-' : tolower (*key  );
  57       char t = (*token == '_') ? '-' : tolower (*token);
  58
  59       if (k != t)
  60         return FALSE;
  61     }
  62
  63   return *key == '\0';
  64 }
  65
  66 /**
  67  * g_parse_debug_string:
  68  * @string: (allow-none): a list of debug options separated by colons, spaces, or
  69  * commas, or %NULL.
  70  * @keys: (array length=nkeys): pointer to an array of #GDebugKey which associate
  71  *     strings with bit flags.
  72  * @nkeys: the number of #GDebugKey<!-- -->s in the array.
  73  *
  74  * Parses a string containing debugging options
  75  * into a %guint containing bit flags. This is used
  76  * within GDK and GTK+ to parse the debug options passed on the
  77  * command line or through environment variables.
  78  *
  79  * If @string is equal to <code>"all"</code>, all flags are set. Any flags
  80  * specified along with <code>"all"</code> in @string are inverted; thus,
  81  * <code>"all,foo,bar"</code> or <code>"foo,bar,all"</code> sets all flags
  82  * except those corresponding to <code>"foo"</code> and <code>"bar"</code>.
  83  *
  84  * If @string is equal to <code>"help"</code>, all the available keys in @keys
  85  * are printed out to standard error.
  86  *
  87  * Returns: the combined set of bit flags.
  88  */
  89 guint
  90 g_parse_debug_string  (const gchar     *string,
  91                        const GDebugKey *keys,
  92                        guint            nkeys)
  93 {
  94   guint i;
  95   guint result = 0;
  96
  97   if (string == NULL)
  98     return 0;
  99
 100   /* this function is used during the initialisation of gmessages, gmem
 101    * and gslice, so it may not do anything that causes memory to be
 102    * allocated or risks messages being emitted.
 103    *
 104    * this means, more or less, that this code may not call anything
 105    * inside GLib.
 106    */
 107
 108   if (!strcasecmp (string, "help"))
 109     {
 110       /* using stdio directly for the reason stated above */
 111       fprintf (stderr, "Supported debug values:");
 112       for (i = 0; i < nkeys; i++)
 113        fprintf (stderr, " %s", keys[i].key);
 114       fprintf (stderr, " all help\n");
 115     }
 116   else
 117     {
 118       const gchar *p = string;
 119       const gchar *q;
 120       gboolean invert = FALSE;
 121
 122       while (*p)
 123        {
 124          q = strpbrk (p, ":;, \t");
 125          if (!q)
 126            q = p + strlen (p);
 127
 128          if (debug_key_matches ("all", p, q - p))
 129            {
 130              invert = TRUE;
 131            }
 132          else
 133            {
 134              for (i = 0; i < nkeys; i++)
 135                if (debug_key_matches (keys[i].key, p, q - p))
 136                  result |= keys[i].value;
 137            }
 138
 139          p = q;
 140          if (*p)
 141            p++;
 142        }
 143
 144       if (invert)
 145         {
 146           guint all_flags = 0;
 147
 148           for (i = 0; i < nkeys; i++)
 149             all_flags |= keys[i].value;
 150
 151           result = all_flags & (~result);
 152         }
 153     }
 154
 155   return result;
 156 }
 157
 158 static guint
 159 g_parse_debug_envvar (const gchar     *envvar,
 160                       const GDebugKey *keys,
 161                       gint             n_keys)
 162 {
 163   const gchar *value;
 164
 165 #ifdef OS_WIN32
 166   /* "fatal-warnings,fatal-criticals,all,help" is pretty short */
 167   gchar buffer[80];
 168
 169   if (GetEnvironmentVariable (envvar, buffer, 100) < 100)
 170     value = buffer;
 171   else
 172     return 0;
 173 #else
 174   value = getenv (envvar);
 175 #endif
 176
 177   return g_parse_debug_string (value, keys, n_keys);
 178 }
 179
 180 static void
 181 g_messages_prefixed_init (void)
 182 {
 183   const GDebugKey keys[] = {
 184     { "error", G_LOG_LEVEL_ERROR },
 185     { "critical", G_LOG_LEVEL_CRITICAL },
 186     { "warning", G_LOG_LEVEL_WARNING },
 187     { "message", G_LOG_LEVEL_MESSAGE },
 188     { "info", G_LOG_LEVEL_INFO },
 189     { "debug", G_LOG_LEVEL_DEBUG }
 190   };
 191
 192   g_log_msg_prefix = g_parse_debug_envvar ("G_MESSAGES_PREFIXED", keys, G_N_ELEMENTS (keys));
 193 }
 194
 195 static void
 196 g_debug_init (void)
 197 {
 198   const GDebugKey keys[] = {
 199     { "gc-friendly", 1 },
 200     {"fatal-warnings",  G_LOG_LEVEL_WARNING | G_LOG_LEVEL_CRITICAL },
 201     {"fatal-criticals", G_LOG_LEVEL_CRITICAL }
 202   };
 203   GLogLevelFlags flags;
 204
 205   flags = g_parse_debug_envvar ("G_DEBUG", keys, G_N_ELEMENTS (keys));
 206
 207   g_log_always_fatal |= flags & G_LOG_LEVEL_MASK;
 208
 209   g_mem_gc_friendly = flags & 1;
 210 }
 211
 212 static void
 213 glib_init (void)
 214 {
 215   g_messages_prefixed_init ();
 216   g_debug_init ();
 217 }
 218
 219 #if defined (G_OS_WIN32)
 220
 221 HMODULE glib_dll;
 222
 223 BOOL WINAPI
 224 DllMain (HINSTANCE hinstDLL,
 225          DWORD     fdwReason,
 226          LPVOID    lpvReserved)
 227 {
 228   switch (fdwReason)
 229     {
 230     case DLL_PROCESS_ATTACH:
 231       glib_dll = hinstDLL;
 232       g_clock_win32_init ();
 233       g_thread_win32_init ();
 234       glib_init ();
 235       break;
 236
 237     case DLL_THREAD_DETACH:
 238       g_thread_win32_thread_detach ();
 239       break;
 240
 241     default:
 242       /* do nothing */
 243       ;
 244     }
 245
 246   return TRUE;
 247 }
 248
 249 #elif defined (__GNUC__)
 250
 251 __attribute__ ((constructor)) static void
 252 glib_init_ctor (void)
 253 {
 254   glib_init ();
 255 }
 256
 257 #else
 258 # error Your platform/compiler is missing constructor support
 259 #endif