2005-12-13 Ulrich Drepper <drepper@redhat.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/debug/backtrace.c b/debug/backtrace.c
new file mode 100644
index 0000000000..f2d52372d5
--- /dev/null
+++ b/debug/backtrace.c
@@ -0,0 +1,94 @@
+/* Return backtrace of current program state.  Generic version.
+   Copyright (C) 1998, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
+
+   The GNU C 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 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <execinfo.h>
+#include <signal.h>
+#include <frame.h>
+#include <sigcontextinfo.h>
+#include <bp-checks.h>
+#include <ldsodefs.h>
+
+/* This implementation assumes a stack layout that matches the defaults
+   used by gcc's `__builtin_frame_address' and `__builtin_return_address'
+   (FP is the frame pointer register):
+
+	  +-----------------+     +-----------------+
+    FP -> | previous FP --------> | previous FP ------>...
+	  |                 |     |                 |
+	  | return address  |     | return address  |
+	  +-----------------+     +-----------------+
+
+  */
+
+/* Get some notion of the current stack.  Need not be exactly the top
+   of the stack, just something somewhere in the current frame.  */
+#ifndef CURRENT_STACK_FRAME
+# define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
+#endif
+
+/* By default we assume that the stack grows downward.  */
+#ifndef INNER_THAN
+# define INNER_THAN <
+#endif
+
+/* By default assume the `next' pointer in struct layout points to the
+   next struct layout.  */
+#ifndef ADVANCE_STACK_FRAME
+# define ADVANCE_STACK_FRAME(next) BOUNDED_1 ((struct layout *) (next))
+#endif
+
+/* By default, the frame pointer is just what we get from gcc.  */
+#ifndef FIRST_FRAME_POINTER
+# define FIRST_FRAME_POINTER  __builtin_frame_address (0)
+#endif
+
+int
+__backtrace (array, size)
+     void **array;
+     int size;
+{
+  struct layout *current;
+  void *__unbounded top_frame;
+  void *__unbounded top_stack;
+  int cnt = 0;
+
+  top_frame = FIRST_FRAME_POINTER;
+  top_stack = CURRENT_STACK_FRAME;
+
+  /* We skip the call to this function, it makes no sense to record it.  */
+  current = BOUNDED_1 ((struct layout *) top_frame);
+  while (cnt < size)
+    {
+      if ((void *) current INNER_THAN top_stack
+	  || !((void *) current INNER_THAN __libc_stack_end))
+       /* This means the address is out of range.  Note that for the
+	  toplevel we see a frame pointer with value NULL which clearly is
+	  out of range.  */
+	break;
+
+      array[cnt++] = current->return_address;
+
+      current = ADVANCE_STACK_FRAME (current->next);
+    }
+
+  return cnt;
+}
+weak_alias (__backtrace, backtrace)
+libc_hidden_def (__backtrace)