Update.

1998-06-08 18:57  Ulrich Drepper  <drepper@cygnus.com>

	* Makeconfig (subdirs): Add debug.
	* configure.in: Use sysdeps/generic/elf subdir if ELF platform.
	* libc.map: Add __backtrace, __backtrace_symbols, backtrace and
	backtrace_symbols.
	* sysdeps/generic/backtrace.c: New file.
	* sysdeps/generic/backtracesyms.c: New file.
	* sysdeps/generic/elf/backtracesyms.c: New file.
	* sysdeps/i386/backtrace.c: New file.
	* debug/Makefile: New file.
	* debug/backtrace-tst.c: New file.
	* debug/execinfo.h: New file.

debug/Makefile

@@ -0,0 +1,32 @@
+# Copyright (C) 1998 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Library General Public License as
+# published by the Free Software Foundation; either version 2 of the
+# License, or (at your option) any later version.
+
+# The GNU C 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
+# Library General Public License for more details.
+
+# You should have received a copy of the GNU Library General Public
+# License along with the GNU C Library; see the file COPYING.LIB.  If not,
+# write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+#
+#	Sub-makefile for debug portion of the library.
+#
+subdir	:= debug
+
+headers	:= execinfo.h
+
+routines := backtrace backtracesyms
+
+CFLAGS-backtrace.c = -fno-omit-frame-pointer
+
+tests = backtrace-tst
+
+include ../Rules

debug/backtrace-tst.c

@@ -0,0 +1,44 @@
+#include <execinfo.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+
+static int
+compare (const void *p1, const void *p2)
+{
+  void *ba[20];
+  int n = backtrace (ba, sizeof (ba) / sizeof (ba[0]));
+  if (n != 0)
+    {
+      char **names = backtrace_symbols (ba, n);
+      if (names != NULL)
+	{
+	  int i;
+	  printf ("called from %s\n", names[0]);
+	  for (i = 1; i < n; ++i)
+	    printf ("            %s\n", names[i]);
+	  free (names);
+	}
+    }
+
+  return *(uint32_t *) p1 - *(uint32_t *) p2;
+}
+
+
+int
+main (int argc, char *argv[])
+{
+  uint32_t arr[20];
+  size_t cnt;
+
+  for (cnt = 0; cnt < sizeof (arr) / sizeof (arr[0]); ++cnt)
+    arr[cnt] = random ();
+
+  qsort (arr, sizeof (arr) / sizeof (arr[0]), sizeof (arr[0]), compare);
+
+  for (cnt = 0; cnt < sizeof (arr) / sizeof (arr[0]); ++cnt)
+    printf ("%" PRIx32 "\n", arr[cnt]);
+
+  return 0;
+}

debug/execinfo.h

@@ -0,0 +1,39 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _EXECINFO_H
+#define _EXECINFO_H 1
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+/* Store up to SIZE return address of the current program state in
+   ARRAY and return the exact number of values stored.  */
+extern int __backtrace __P ((void **__array, int __size));
+extern int backtrace __P ((void **__array, int __size));
+
+
+/* Return names of functions from the backtrace list in ARRAY in a newly
+   malloc()ed memory block.  */
+extern char **__backtrace_symbols __P ((__const void **__array, int __size));
+extern char **backtrace_symbols __P ((__const void **__array, int __size));
+
+__END_DECLS
+
+#endif /* execinfo.h  */