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-rw-r--r--sysdeps/powerpc/backtrace.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/sysdeps/powerpc/backtrace.c b/sysdeps/powerpc/backtrace.c
new file mode 100644
index 0000000000..7d71fbd9a8
--- /dev/null
+++ b/sysdeps/powerpc/backtrace.c
@@ -0,0 +1,63 @@
+/* Return backtrace of current program state.
+   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.  */
+
+#include <execinfo.h>
+
+/* This is the stack layout we see with every stack frame.
+   Note that every routine is required by the ABI to lay out the stack
+   like this.
+
+            +----------------+        +-----------------+
+    %r1  -> | %r1 last frame--------> | %r1 last frame--->...  --> NULL
+            |                |        |                 |
+            | (unused)       |        | return address  |
+            +----------------+        +-----------------+
+*/
+struct layout
+{
+  struct layout *next;
+  void *return_address;
+};
+
+int
+__backtrace (void **array, int size)
+{
+  struct layout *current;
+  int count;
+  
+  /* Force gcc to spill LR.  */
+  asm volatile ("" : "=l"(current));
+
+  /* Get the address on top-of-stack.  */
+  asm volatile ("lwz %0,0(1)" : "=r"(current));
+
+  for (				count = 0;
+       current != NULL && 	count < size;
+       current = current->next, count++)
+    array[count] = current->return_address;
+
+  /* It's possible the second-last stack frame can't return
+     (that is, it's __libc_start_main), in which case
+     the CRT startup code will have set its LR to 'NULL'.  */
+  if (count > 0 && array[count-1] == NULL)
+    count--;
+
+  return count;
+}
+weak_alias (__backtrace, backtrace)