glib/gmessages.c

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/. 
 */

/* 
 * MT safe
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include "glib.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <signal.h>
#include <locale.h>
#include <errno.h>

#ifdef G_OS_WIN32
typedef FILE* GFileDescriptor;
#else
typedef gint GFileDescriptor;
#endif

/* --- structures --- */
typedef struct _GLogDomain	GLogDomain;
typedef struct _GLogHandler	GLogHandler;
struct _GLogDomain
{
  gchar		*log_domain;
  GLogLevelFlags fatal_mask;
  GLogHandler	*handlers;
  GLogDomain	*next;
};
struct _GLogHandler
{
  guint		 id;
  GLogLevelFlags log_level;
  GLogFunc	 log_func;
  gpointer	 data;
  GLogHandler	*next;
};


/* --- prototypes --- */
static inline guint printf_string_upper_bound (const gchar *format,
					       gboolean     may_warn,
					       va_list      args);


/* --- variables --- */

static GMutex* g_messages_lock = NULL;

const gchar	     *g_log_domain_glib = "GLib";
static GLogDomain    *g_log_domains = NULL;
static GLogLevelFlags g_log_always_fatal = G_LOG_FATAL_MASK;
static GPrintFunc     glib_print_func = NULL;
static GPrintFunc     glib_printerr_func = NULL;
static GErrorFunc     glib_error_func = NULL;
static GWarningFunc   glib_warning_func = NULL;
static GPrintFunc     glib_message_func = NULL;

static GPrivate* g_log_depth = NULL;

/* --- functions --- */
#ifdef G_OS_WIN32
#  define STRICT
#  include <windows.h>
#  undef STRICT
#  include <process.h>          /* For _getpid() */

static gboolean alloc_console_called = FALSE;

static gboolean gonna_abort = FALSE;

/* This default message will usually be overwritten. */
/* Yes, a fixed size buffer is bad. So sue me. But g_error is never
 * with huge strings, is it? */
static char fatal_msg_buf[1000] = "Unspecified fatal error encountered, aborting.";
static char *fatal_msg_ptr = fatal_msg_buf;

/* Just use stdio. If we're out of memory, we're hosed anyway. */
#undef write
static inline int
dowrite (GFileDescriptor fd,
	 const void  *buf,
	 unsigned int len)
{
  if (gonna_abort)
    {
      memcpy (fatal_msg_ptr, buf, len);
      fatal_msg_ptr += len;
      *fatal_msg_ptr = 0;
      return len;
    }

  fwrite (buf, len, 1, fd);
  fflush (fd);

  return len;
}

#define write(fd, buf, len) dowrite(fd, buf, len)

static void
ensure_stdout_valid (void)
{
  HANDLE handle;

  if (gonna_abort)
    return;

  if (!alloc_console_called)
    {
      handle = GetStdHandle (STD_OUTPUT_HANDLE);
  
      if (handle == INVALID_HANDLE_VALUE)
	{
	  AllocConsole ();
	  alloc_console_called = TRUE;
	  freopen ("CONOUT$", "w", stdout);
	}
    }
}
#else
#define ensure_stdout_valid()	/* Define as empty */
#endif

static void
write_unsigned (GFileDescriptor   fd,
		gulong num,
		guint  radix)
{
  char buffer[64];
  gulong tmp;
  char c;
  int i, n;

  g_return_if_fail (radix >= 2 && radix <= 36);
  
  if (!num)
    {
      write (fd, "0", 1);
      return;
    } 
  
  if (radix == 16)
    write (fd, "0x", 2);
  else if (radix == 8)
    write (fd, "0", 1);
	
  n = 0;
  tmp = num;
  while (tmp)
    {
      tmp /= radix;
      n++;
    }

  i = n;
  while (num)
    {
      i--;
      c = (num % radix);
      if (c < 10)
	buffer[i] = c + '0';
      else
	buffer[i] = c + 'a' - 10;
      num /= radix;
    }
  
  write (fd, buffer, n);
}

static void
write_string (GFileDescriptor fd,
	      gchar *string)
{
  write (fd, string, strlen (string));
}

static void
g_log_write_prefix (GFileDescriptor fd,
                    GLogLevelFlags mask)
{
  static GLogLevelFlags g_log_msg_prefix = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_WARNING | G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_DEBUG;
  static gboolean initialized = FALSE;
  
  g_mutex_lock (g_messages_lock);

  if (!initialized)
    {
      const gchar *val;
      initialized = TRUE;

      val = g_getenv ("G_MESSAGES_PREFIXED");
      
      if (val)
        {
          static const GDebugKey keys[] = {
            { "error", G_LOG_LEVEL_ERROR },
            { "critical", G_LOG_LEVEL_CRITICAL },
            { "warning", G_LOG_LEVEL_WARNING },
            { "message", G_LOG_LEVEL_MESSAGE },
            { "info", G_LOG_LEVEL_INFO },
            { "debug", G_LOG_LEVEL_DEBUG }
          };
          
          g_log_msg_prefix = g_parse_debug_string (val, keys, G_N_ELEMENTS (keys));
        }
    }
  
  g_mutex_unlock (g_messages_lock);
  
  if ((g_log_msg_prefix & mask) == mask)
    {
      gchar *prg_name;

      prg_name = g_get_prgname ();

      if (!prg_name)
	write_string (fd, "(process:");
      else
	{
	  write_string (fd, prg_name);
	  write_string (fd, " (pid:");
	}

      write_unsigned (fd, getpid (), 10);
      write_string (fd, "): ");
    }
}

static inline GLogDomain*
g_log_find_domain (const gchar *log_domain)
{
  register GLogDomain *domain;
  
  g_mutex_lock (g_messages_lock);
  domain = g_log_domains;
  while (domain)
    {
      if (strcmp (domain->log_domain, log_domain) == 0)
	{
	  g_mutex_unlock (g_messages_lock);
	  return domain;
	}
      domain = domain->next;
    }
  g_mutex_unlock (g_messages_lock);
  return NULL;
}

static inline GLogDomain*
g_log_domain_new (const gchar *log_domain)
{
  register GLogDomain *domain;

  domain = g_new (GLogDomain, 1);
  domain->log_domain = g_strdup (log_domain);
  domain->fatal_mask = G_LOG_FATAL_MASK;
  domain->handlers = NULL;
  
  g_mutex_lock (g_messages_lock);
  domain->next = g_log_domains;
  g_log_domains = domain;
  g_mutex_unlock (g_messages_lock);
  
  return domain;
}

static inline void
g_log_domain_check_free (GLogDomain *domain)
{
  if (domain->fatal_mask == G_LOG_FATAL_MASK &&
      domain->handlers == NULL)
    {
      register GLogDomain *last, *work;
      
      last = NULL;  

      g_mutex_lock (g_messages_lock);
      work = g_log_domains;
      while (work)
	{
	  if (work == domain)
	    {
	      if (last)
		last->next = domain->next;
	      else
		g_log_domains = domain->next;
	      g_free (domain->log_domain);
	      g_free (domain);
	      break;
	    }
	  last = work;
	  work = last->next;
	}  
      g_mutex_unlock (g_messages_lock);
    }
}

static inline GLogFunc
g_log_domain_get_handler (GLogDomain	*domain,
			  GLogLevelFlags log_level,
			  gpointer	*data)
{
  if (domain && log_level)
    {
      register GLogHandler *handler;
      
      handler = domain->handlers;
      while (handler)
	{
	  if ((handler->log_level & log_level) == log_level)
	    {
	      *data = handler->data;
	      return handler->log_func;
	    }
	  handler = handler->next;
	}
    }
  return g_log_default_handler;
}

GLogLevelFlags
g_log_set_always_fatal (GLogLevelFlags fatal_mask)
{
  GLogLevelFlags old_mask;

  /* restrict the global mask to levels that are known to glib */
  fatal_mask &= (1 << G_LOG_LEVEL_USER_SHIFT) - 1;
  /* force errors to be fatal */
  fatal_mask |= G_LOG_LEVEL_ERROR;
  /* remove bogus flag */
  fatal_mask &= ~G_LOG_FLAG_FATAL;

  g_mutex_lock (g_messages_lock);
  old_mask = g_log_always_fatal;
  g_log_always_fatal = fatal_mask;
  g_mutex_unlock (g_messages_lock);

  return old_mask;
}

GLogLevelFlags
g_log_set_fatal_mask (const gchar    *log_domain,
		      GLogLevelFlags  fatal_mask)
{
  GLogLevelFlags old_flags;
  register GLogDomain *domain;
  
  if (!log_domain)
    log_domain = "";
  
  /* force errors to be fatal */
  fatal_mask |= G_LOG_LEVEL_ERROR;
  /* remove bogus flag */
  fatal_mask &= ~G_LOG_FLAG_FATAL;
  
  domain = g_log_find_domain (log_domain);
  if (!domain)
    domain = g_log_domain_new (log_domain);
  old_flags = domain->fatal_mask;
  
  domain->fatal_mask = fatal_mask;
  g_log_domain_check_free (domain);
  
  return old_flags;
}

guint
g_log_set_handler (const gchar	  *log_domain,
		   GLogLevelFlags  log_levels,
		   GLogFunc	   log_func,
		   gpointer	   user_data)
{
  register GLogDomain *domain;
  register GLogHandler *handler;
  static guint handler_id = 0;
  
  g_return_val_if_fail ((log_levels & G_LOG_LEVEL_MASK) != 0, 0);
  g_return_val_if_fail (log_func != NULL, 0);
  
  if (!log_domain)
    log_domain = "";
  
  domain = g_log_find_domain (log_domain);
  if (!domain)
    domain = g_log_domain_new (log_domain);
  
  handler = g_new (GLogHandler, 1);
  g_mutex_lock (g_messages_lock);
  handler->id = ++handler_id;
  g_mutex_unlock (g_messages_lock);
  handler->log_level = log_levels;
  handler->log_func = log_func;
  handler->data = user_data;
  handler->next = domain->handlers;
  domain->handlers = handler;
  
  return handler_id;
}

void
g_log_remove_handler (const gchar *log_domain,
		      guint	   handler_id)
{
  register GLogDomain *domain;
  
  g_return_if_fail (handler_id > 0);
  
  if (!log_domain)
    log_domain = "";
  
  domain = g_log_find_domain (log_domain);
  if (domain)
    {
      register GLogHandler *work, *last;
      
      last = NULL;
      work = domain->handlers;
      while (work)
	{
	  if (work->id == handler_id)
	    {
	      if (last)
		last->next = work->next;
	      else
		domain->handlers = work->next;
	      g_free (work);
	      g_log_domain_check_free (domain);
	      return;
	    }
	  last = work;
	  work = last->next;
	}
    }
  g_warning ("g_log_remove_handler(): could not find handler with id `%d' for domain \"%s\"",
	     handler_id,
	     log_domain);
}

void
g_logv (const gchar   *log_domain,
	GLogLevelFlags log_level,
	const gchar   *format,
	va_list	       args1)
{
  va_list args2;
  gchar buffer[1025];
  register gint i;
  
  log_level &= G_LOG_LEVEL_MASK;
  if (!log_level)
    return;
  
  /* we use a stack buffer of fixed size, because we might get called
   * recursively.
   */
  G_VA_COPY (args2, args1);
  if (printf_string_upper_bound (format, FALSE, args1) < 1024)
    vsprintf (buffer, format, args2);
  else
    {
      /* since we might be out of memory, we can't use g_vsnprintf(). */
#ifdef  HAVE_VSNPRINTF
      vsnprintf (buffer, 1024, format, args2);
#else	/* !HAVE_VSNPRINTF */
      /* we are out of luck here */
      strncpy (buffer, format, 1024);
#endif	/* !HAVE_VSNPRINTF */
      buffer[1024] = 0;
    }
  va_end (args2);
  
  for (i = g_bit_nth_msf (log_level, -1); i >= 0; i = g_bit_nth_msf (log_level, i))
    {
      register GLogLevelFlags test_level;
      
      test_level = 1 << i;
      if (log_level & test_level)
	{
	  guint depth = GPOINTER_TO_UINT (g_private_get (g_log_depth));
	  GLogDomain *domain;
	  GLogFunc log_func;
	  gpointer data = NULL;
	  
	  domain = g_log_find_domain (log_domain ? log_domain : "");
	  
	  if (depth)
	    test_level |= G_LOG_FLAG_RECURSION;
	  
	  depth++;
	  g_private_set (g_log_depth, GUINT_TO_POINTER (depth));

	  g_mutex_lock (g_messages_lock);
	  if ((((domain ? domain->fatal_mask : G_LOG_FATAL_MASK) | 
		g_log_always_fatal) & test_level) != 0)
	    test_level |= G_LOG_FLAG_FATAL;  
	  g_mutex_unlock (g_messages_lock);

	  log_func = g_log_domain_get_handler (domain, test_level, &data);
	  log_func (log_domain, test_level, buffer, data);
	  
	  /* *domain can be cluttered now */
	  
	  if (test_level & G_LOG_FLAG_FATAL)
	    {
#if defined (G_ENABLE_DEBUG) && defined (SIGTRAP)
	      if (!(test_level & G_LOG_FLAG_RECURSION))
		raise (SIGTRAP);
	      else
		abort ();
#else /* !G_ENABLE_DEBUG || !SIGTRAP */
#ifdef G_OS_WIN32
	      MessageBox (NULL, fatal_msg_buf, NULL, MB_OK);
#endif
# if defined (_MSC_VER) && defined (_DEBUG)
	      /* let's see the call stack ... */
	      __asm int 3
# endif
	      abort ();
#endif /* !G_ENABLE_DEBUG || !SIGTRAP */
	    }
	  
	  depth--;
	  g_private_set (g_log_depth, GUINT_TO_POINTER (depth));
	}
    }
}

void
g_log (const gchar    *log_domain,
       GLogLevelFlags  log_level,
       const gchar    *format,
       ...)
{
  va_list args;
  
  va_start (args, format);
  g_logv (log_domain, log_level, format, args);
  va_end (args);
}

void
g_log_default_handler (const gchar    *log_domain,
		       GLogLevelFlags  log_level,
		       const gchar    *message,
		       gpointer	       unused_data)
{
  GFileDescriptor fd;
  gboolean in_recursion;
  gboolean is_fatal;  
  GErrorFunc local_glib_error_func;
  GWarningFunc local_glib_warning_func;
  GPrintFunc local_glib_message_func;
  
  in_recursion = (log_level & G_LOG_FLAG_RECURSION) != 0;
  is_fatal = (log_level & G_LOG_FLAG_FATAL) != 0;
  log_level &= G_LOG_LEVEL_MASK;
  
  if (!message)
    message = "g_log_default_handler(): (NULL) message";
  
#ifdef G_OS_WIN32
  /* Use just stdout as stderr is hard to get redirected from the
   * DOS prompt.
   */
  fd = stdout;
  gonna_abort = is_fatal;
#else
  fd = (log_level > G_LOG_LEVEL_MESSAGE) ? 1 : 2;
#endif
  
  g_mutex_lock (g_messages_lock);
  local_glib_error_func = glib_error_func;
  local_glib_warning_func = glib_warning_func;
  local_glib_message_func = glib_message_func;
  g_mutex_unlock (g_messages_lock);

  switch (log_level)
    {
    case G_LOG_LEVEL_ERROR:
      if (!log_domain && local_glib_error_func)
	{
	  /* compatibility code */
	  local_glib_error_func (message);  
	  return;
	}
      /* use write(2) for output, in case we are out of memeory */
      ensure_stdout_valid ();
      write (fd, "\n", 1);
      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      else
	write (fd, "** ", 3);
      if (in_recursion)
	write (fd, "ERROR (recursed) **: ", 21);
      else
	write (fd, "ERROR **: ", 10);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    case G_LOG_LEVEL_CRITICAL:
      ensure_stdout_valid ();
      write (fd, "\n", 1);
      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      else
	write (fd, "** ", 3);
      if (in_recursion)
	write (fd, "CRITICAL (recursed) **: ", 24);
      else
	write (fd, "CRITICAL **: ", 13);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    case G_LOG_LEVEL_WARNING:
      if (!log_domain && local_glib_warning_func)
	{
	  /* compatibility code */
	  local_glib_warning_func (message);
	  return;
	}
      ensure_stdout_valid ();
      write (fd, "\n", 1);
      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      else
	write (fd, "** ", 3);
      if (in_recursion)
	write (fd, "WARNING (recursed) **: ", 23);
      else
	write (fd, "WARNING **: ", 12);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    case G_LOG_LEVEL_MESSAGE:
      if (!log_domain && local_glib_message_func)
	{
	  /* compatibility code */
	  local_glib_message_func (message);
	  return;
	}
      ensure_stdout_valid ();

      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      if (in_recursion)
	write (fd, "Message (recursed): ", 20);
      else
	write (fd, "Message: ", 9);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    case G_LOG_LEVEL_INFO:
      ensure_stdout_valid ();

      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      if (in_recursion)
	write (fd, "INFO (recursed): ", 17);
      else
	write (fd, "INFO: ", 6);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    case G_LOG_LEVEL_DEBUG:
      ensure_stdout_valid ();

      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  write (fd, "-", 1);
	}
      if (in_recursion)
	write (fd, "DEBUG (recursed): ", 18);
      else
	write (fd, "DEBUG: ", 7);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    default:
      /* we are used for a log level that is not defined by GLib itself,
       * try to make the best out of it.
       */
      ensure_stdout_valid ();

      g_log_write_prefix (fd, log_level);

      if (log_domain)
	{
	  write (fd, log_domain, strlen (log_domain));
	  if (in_recursion)
	    write (fd, "-LOG (recursed:", 15);
	  else
	    write (fd, "-LOG (", 6);
	}
      else if (in_recursion)
	write (fd, "LOG (recursed:", 14);
      else
	write (fd, "LOG (", 5);
      if (log_level)
	{
	  gchar string[] = "0x00): ";
	  gchar *p = string + 2;
	  guint i;
	  
	  i = g_bit_nth_msf (log_level, -1);
	  *p = i >> 4;
	  p++;
	  *p = '0' + (i & 0xf);
	  if (*p > '9')
	    *p += 'A' - '9' - 1;
	  
	  write (fd, string, 7);
	}
      else
	write (fd, "): ", 3);
      write (fd, message, strlen (message));
      if (is_fatal)
	write (fd, "\naborting...\n", 13);
      else
	write (fd, "\n", 1);
      break;
    }
}

GPrintFunc
g_set_print_handler (GPrintFunc func)
{
  GPrintFunc old_print_func;
  
  g_mutex_lock (g_messages_lock);
  old_print_func = glib_print_func;
  glib_print_func = func;
  g_mutex_unlock (g_messages_lock);
  
  return old_print_func;
}

void
g_print (const gchar *format,
	 ...)
{
  va_list args;
  gchar *string;
  GPrintFunc local_glib_print_func;
  
  g_return_if_fail (format != NULL);
  
  va_start (args, format);
  string = g_strdup_vprintf (format, args);
  va_end (args);
  
  g_mutex_lock (g_messages_lock);
  local_glib_print_func = glib_print_func;
  g_mutex_unlock (g_messages_lock);

  if (local_glib_print_func)
    local_glib_print_func (string);
  else
    {
      ensure_stdout_valid ();
      fputs (string, stdout);
      fflush (stdout);
    }
  g_free (string);
}

GPrintFunc
g_set_printerr_handler (GPrintFunc func)
{
  GPrintFunc old_printerr_func;
  
  g_mutex_lock (g_messages_lock);
  old_printerr_func = glib_printerr_func;
  glib_printerr_func = func;
  g_mutex_unlock (g_messages_lock);
  
  return old_printerr_func;
}

void
g_printerr (const gchar *format,
	    ...)
{
  va_list args;
  gchar *string;
  GPrintFunc local_glib_printerr_func;
  
  g_return_if_fail (format != NULL);
  
  va_start (args, format);
  string = g_strdup_vprintf (format, args);
  va_end (args);
  
  g_mutex_lock (g_messages_lock);
  local_glib_printerr_func = glib_printerr_func;
  g_mutex_unlock (g_messages_lock);

  if (local_glib_printerr_func)
    local_glib_printerr_func (string);
  else
    {
      fputs (string, stderr);
      fflush (stderr);
    }
  g_free (string);
}

/* compatibility code */
GErrorFunc
g_set_error_handler (GErrorFunc func)
{
  GErrorFunc old_error_func;
  
  g_mutex_lock (g_messages_lock);
  old_error_func = glib_error_func;
  glib_error_func = func;
  g_mutex_unlock (g_messages_lock);
 
  return old_error_func;
}

/* compatibility code */
GWarningFunc
g_set_warning_handler (GWarningFunc func)
{
  GWarningFunc old_warning_func;
  
  g_mutex_lock (g_messages_lock);
  old_warning_func = glib_warning_func;
  glib_warning_func = func;
  g_mutex_unlock (g_messages_lock);
  
  return old_warning_func;
}

/* compatibility code */
GPrintFunc
g_set_message_handler (GPrintFunc func)
{
  GPrintFunc old_message_func;
  
  g_mutex_lock (g_messages_lock);
  old_message_func = glib_message_func;
  glib_message_func = func;
  g_mutex_unlock (g_messages_lock);
  
  return old_message_func;
}

#ifndef MB_LEN_MAX
#  define MB_LEN_MAX 8
#endif

typedef struct
{
  guint min_width;
  guint precision;
  gboolean alternate_format, zero_padding, adjust_left, locale_grouping;
  gboolean add_space, add_sign, possible_sign, seen_precision;
  gboolean mod_half, mod_long, mod_extra_long;
} PrintfArgSpec;

static inline guint
printf_string_upper_bound (const gchar *format,
			   gboolean     may_warn,
			   va_list      args)
{
  static const gboolean honour_longs = SIZEOF_LONG > 4 || SIZEOF_VOID_P > 4;
  guint len = 1;

  if (!format)
    return len;

  while (*format)
    {
      register gchar c = *format++;

      if (c != '%')
	len += 1;
      else /* (c == '%') */
	{
	  PrintfArgSpec spec = { 0, };
	  gboolean seen_l = FALSE, conv_done = FALSE;
	  guint conv_len = 0;
	  const gchar *spec_start = format;

	  do
	    {
	      c = *format++;
	      switch (c)
		{
		  GDoubleIEEE754 u_double;
		  guint v_uint;
		  gint v_int;
		  const gchar *v_string;

		  /* beware of positional parameters
		   */
		case '$':
		  if (may_warn)
		    g_warning (G_GNUC_PRETTY_FUNCTION
			       "(): unable to handle positional parameters (%%n$)");
		  len += 1024; /* try adding some safety padding */
		  break;

		  /* parse flags
		   */
		case '#':
		  spec.alternate_format = TRUE;
		  break;
		case '0':
		  spec.zero_padding = TRUE;
		  break;
		case '-':
		  spec.adjust_left = TRUE;
		  break;
		case ' ':
		  spec.add_space = TRUE;
		  break;
		case '+':
		  spec.add_sign = TRUE;
		  break;
		case '\'':
		  spec.locale_grouping = TRUE;
		  break;

		  /* parse output size specifications
		   */
		case '.':
		  spec.seen_precision = TRUE;
		  break;
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
		case '8':
		case '9':
		  v_uint = c - '0';
		  c = *format;
		  while (c >= '0' && c <= '9')
		    {
		      format++;
		      v_uint = v_uint * 10 + c - '0';
		      c = *format;
		    }
		  if (spec.seen_precision)
		    spec.precision = MAX (spec.precision, v_uint);
		  else
		    spec.min_width = MAX (spec.min_width, v_uint);
		  break;
		case '*':
		  v_int = va_arg (args, int);
		  if (spec.seen_precision)
		    {
		      /* forget about negative precision */
		      if (v_int >= 0)
			spec.precision = MAX (spec.precision, v_int);
		    }
		  else
		    {
		      if (v_int < 0)
			{
			  v_int = - v_int;
			  spec.adjust_left = TRUE;
			}
		      spec.min_width = MAX (spec.min_width, v_int);
		    }
		  break;

		  /* parse type modifiers
		   */
		case 'h':
		  spec.mod_half = TRUE;
		  break;
		case 'l':
		  if (!seen_l)
		    {
		      spec.mod_long = TRUE;
		      seen_l = TRUE;
		      break;
		    }
		  /* else, fall through */
		case 'L':
		case 'q':
		  spec.mod_long = TRUE;
		  spec.mod_extra_long = TRUE;
		  break;
		case 'z':
		case 'Z':
#if GLIB_SIZEOF_SIZE_T > 4
		  spec.mod_long = TRUE;
		  spec.mod_extra_long = TRUE;
#endif /* GLIB_SIZEOF_SIZE_T > 4 */
		  break;
		case 't':
#if GLIB_SIZEOF_PTRDIFF_T > 4
		  spec.mod_long = TRUE;
		  spec.mod_extra_long = TRUE;
#endif /* GLIB_SIZEOF_PTRDIFF_T > 4 */
		  break;
		case 'j':
#if GLIB_SIZEOF_INTMAX_T > 4
		  spec.mod_long = TRUE;
		  spec.mod_extra_long = TRUE;
#endif /* GLIB_SIZEOF_INTMAX_T > 4 */
		  break;

		  /* parse output conversions
		   */
		case '%':
		  conv_len += 1;
		  break;
		case 'O':
		case 'D':
		case 'I':
		case 'U':
		  /* some C libraries feature long variants for these as well? */
		  spec.mod_long = TRUE;
		  /* fall through */
		case 'o':
		  conv_len += 2;
		  /* fall through */
		case 'd':
		case 'i':
		  conv_len += 1; /* sign */
		  /* fall through */
		case 'u':
		  conv_len += 4;
		  /* fall through */
		case 'x':
		case 'X':
		  spec.possible_sign = TRUE;
		  conv_len += 10;
		  if (spec.mod_long && honour_longs)
		    conv_len *= 2;
		  if (spec.mod_extra_long)
		    conv_len *= 2;
		  if (spec.mod_extra_long)
		    {
#ifdef G_HAVE_GINT64
		      (void) va_arg (args, gint64);
#else /* !G_HAVE_GINT64 */
		      (void) va_arg (args, long);
#endif /* !G_HAVE_GINT64 */
		    }
		  else if (spec.mod_long)
		    (void) va_arg (args, long);
		  else
		    (void) va_arg (args, int);
		  break;
		case 'A':
		case 'a':
		  /*          0x */
		  conv_len += 2;
		  /* fall through */
		case 'g':
		case 'G':
		case 'e':
		case 'E':
		case 'f':
		  spec.possible_sign = TRUE;
		  /*          n   .   dddddddddddddddddddddddd   E   +-  eeee */
		  conv_len += 1 + 1 + MAX (24, spec.precision) + 1 + 1 + 4;
                  if (may_warn && spec.mod_extra_long)
		    g_warning (G_GNUC_PRETTY_FUNCTION
			       "(): unable to handle long double, collecting double only");
#ifdef HAVE_LONG_DOUBLE
#error need to implement special handling for long double
#endif
		  u_double.v_double = va_arg (args, double);
		  /* %f can expand up to all significant digits before '.' (308) */
		  if (c == 'f' &&
		      u_double.mpn.biased_exponent > 0 && u_double.mpn.biased_exponent < 2047)
		    {
		      gint exp = u_double.mpn.biased_exponent;

		      exp -= G_IEEE754_DOUBLE_BIAS;
		      exp = exp * G_LOG_2_BASE_10 + 1;
		      conv_len += exp;
		    }
		  /* some printf() implementations require extra padding for rounding */
		  conv_len += 2;
		  /* we can't really handle locale specific grouping here */
		  if (spec.locale_grouping)
		    conv_len *= 2;
		  break;
		case 'C':
		  spec.mod_long = TRUE;
                  /* fall through */
		case 'c':
		  conv_len += spec.mod_long ? MB_LEN_MAX : 1;
		  (void) va_arg (args, int);
		  break;
		case 'S':
		  spec.mod_long = TRUE;
		  /* fall through */
		case 's':
		  v_string = va_arg (args, char*);
		  if (!v_string)
		    conv_len += 8; /* hold "(null)" */
		  else if (spec.seen_precision)
		    conv_len += spec.precision;
		  else
		    conv_len += strlen (v_string);
		  conv_done = TRUE;
		  if (spec.mod_long)
		    {
		      if (may_warn)
			g_warning (G_GNUC_PRETTY_FUNCTION
				   "(): unable to handle wide char strings");
		      len += 1024; /* try adding some safety padding */
		    }
		  break;
		case 'P': /* do we actually need this? */
		  /* fall through */
		case 'p':
		  spec.alternate_format = TRUE;
		  conv_len += 10;
		  if (honour_longs)
		    conv_len *= 2;
		  /* fall through */
		case 'n':
		  conv_done = TRUE;
		  (void) va_arg (args, void*);
		  break;
		case 'm':
		  /* there's not much we can do to be clever */
		  v_string = g_strerror (errno);
		  v_uint = v_string ? strlen (v_string) : 0;
		  conv_len += MAX (256, v_uint);
		  break;

		  /* handle invalid cases
		   */
		case '\000':
		  /* no conversion specification, bad bad */
		  conv_len += format - spec_start;
		  break;
		default:
		  if (may_warn)
		    g_warning (G_GNUC_PRETTY_FUNCTION
			       "(): unable to handle `%c' while parsing format",
			       c);
		  break;
		}
	      conv_done |= conv_len > 0;
	    }
	  while (!conv_done);
	  /* handle width specifications */
	  conv_len = MAX (conv_len, MAX (spec.precision, spec.min_width));
	  /* handle flags */
	  conv_len += spec.alternate_format ? 2 : 0;
	  conv_len += (spec.add_space || spec.add_sign || spec.possible_sign);
	  /* finally done */
	  len += conv_len;
	} /* else (c == '%') */
    } /* while (*format) */

  return len;
}

guint
g_printf_string_upper_bound (const gchar *format,
			     va_list      args)
{
  return printf_string_upper_bound (format, TRUE, args);
}

void
g_messages_init (void)
{
  g_messages_lock = g_mutex_new();
  g_log_depth = g_private_new(NULL);
}