New header containing GTK_DEBUG-style debugging support for GLib.

* glib/gdebug.h: New header containing GTK_DEBUG-style debugging
	support for GLib. Currently only the fatal_warnings debug option exists.

	* glib/gmessages.c (g_log_msg_prefix_init): New one-shot function
	for parsing G_MESSAGES_PREFIXED.
	(_g_debug_init): New one-shot function for parsing G_DEBUG.
	(g_log_write_prefix): Use g_log_msg_prefix_init().
	(g_messages_init): Use g_log_msg_prefix_init() and _g_debug_init().

	* glib/Makefile.am (libglib_1_3_la_SOURCES): Add gdebug.h.


	* glib/Makefile.am (IGNORE_HFILES): Add gdebug.h.

	* glib/running.sgml: Document the G_DEBUG environment variable.

	* glib/tmpl/threads.sgml: Replace g_thread_wait() by
	g_thread_join() in two places.

glib/gdebug.h

@@ -0,0 +1,63 @@
+/* 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
+ * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
+ */
+
+#ifndef __G_DEBUG_H__
+#define __G_DEBUG_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef enum {
+  G_DEBUG_FATAL_WARNINGS = 1 << 0,
+} GDebugFlag;
+
+
+#ifdef G_ENABLE_DEBUG
+
+#define G_NOTE(type, action)            G_STMT_START { \
+    if (!_g_debug_initialized)                         \
+       { _g_debug_init (); }                           \
+    if (_g_debug_flags & G_DEBUG_##type)               \
+       { action; };                         } G_STMT_END
+
+#else /* !G_ENABLE_DEBUG */
+
+#define G_NOTE(type, action)
+      
+#endif /* G_ENABLE_DEBUG */
+
+GLIB_VAR gboolean _g_debug_initialized;
+GLIB_VAR guint _g_debug_flags;
+
+void _g_debug_init ();
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+
+#endif /* __G_DEBUG_H__ */