1 files changed, 86 insertions, 0 deletions
diff --git a/libjava/sysdep/dwarf2-backtrace.cc b/libjava/sysdep/dwarf2-backtrace.cc
new file mode 100644
index 0000000..550aa5b
--- /dev/null
+++ b/libjava/sysdep/dwarf2-backtrace.cc
@@ -0,0 +1,86 @@
+/* dwarf2-backtrac.cc - backtrace implementation driven by the dwarf2
+ exception unwinder.  */
+
+/* Copyright (C) 2003  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+/* Written by David Daney <ddaney@avtrex.com> */
+
+/*
+  Although this in theory could be 'C' instead of C++, saying that it
+  is C++ and including jvm.h makes it easier to insure that the proper
+  compiler options are used.  There must be unwind tables for
+  backtrace because it is on the stack when _Unwind_Backtrace is
+  called.  Compiling as C++ insures this.
+
+*/
+
+#include <config.h>
+
+#include <unwind.h>
+
+#include <jvm.h>
+
+
+extern "C"
+{
+  int backtrace (void **, int);
+}
+
+struct backtrace_state
+{
+  int skip_count;
+  int current_level;
+  int max_level;
+  void **locations;
+};
+
+static _Unwind_Reason_Code
+my_trace_fn (struct _Unwind_Context *uc, void *arg)
+{
+
+  struct backtrace_state *bs = (struct backtrace_state *) arg;
+
+  if (bs->skip_count)
+    {
+      bs->skip_count--;
+      return _URC_NO_REASON;
+    }
+
+  _Unwind_Ptr loc = _Unwind_GetIP (uc);
+
+  if (bs->current_level < bs->max_level)
+    bs->locations[bs->current_level++] = (void *) loc;
+
+  if (bs->current_level >= bs->max_level)
+    return _URC_END_OF_STACK;
+  else
+    return _URC_NO_REASON;
+}
+
+/*
+ * backtrace is defined in (some versions of) libc.  This definition
+ * must match so that it can replace the libc version at link time.
+ *
+ * Fill the locations array with at most len back trace locations.
+ *
+ * Returns the number of locations actually filled in.
+ *
+ */
+int
+backtrace (void **locations, int len)
+{
+  struct backtrace_state bs;
+  bs.skip_count = 1;		/* Don't log the call to backtrace itself. */
+  bs.current_level = 0;
+  bs.max_level = len;
+  bs.locations = locations;
+
+  _Unwind_Backtrace (my_trace_fn, &bs);
+  return bs.current_level;
+}