CFI support: lookup by PC and translate into DWARF location per register
diff --git a/libdw/dwarf_frame_cfa.c b/libdw/dwarf_frame_cfa.c
new file mode 100644
index 0000000..ccd7702
--- /dev/null
+++ b/libdw/dwarf_frame_cfa.c
@@ -0,0 +1,101 @@
+/* Get CFA expression for frame.
+ Copyright (C) 2009 Red Hat, Inc.
+ This file is part of Red Hat elfutils.
+
+ Red Hat elfutils is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by the
+ Free Software Foundation; version 2 of the License.
+
+ Red Hat elfutils 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with Red Hat elfutils; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
+
+ In addition, as a special exception, Red Hat, Inc. gives You the
+ additional right to link the code of Red Hat elfutils with code licensed
+ under any Open Source Initiative certified open source license
+ (http://www.opensource.org/licenses/index.php) which requires the
+ distribution of source code with any binary distribution and to
+ distribute linked combinations of the two. Non-GPL Code permitted under
+ this exception must only link to the code of Red Hat elfutils through
+ those well defined interfaces identified in the file named EXCEPTION
+ found in the source code files (the "Approved Interfaces"). The files
+ of Non-GPL Code may instantiate templates or use macros or inline
+ functions from the Approved Interfaces without causing the resulting
+ work to be covered by the GNU General Public License. Only Red Hat,
+ Inc. may make changes or additions to the list of Approved Interfaces.
+ Red Hat's grant of this exception is conditioned upon your not adding
+ any new exceptions. If you wish to add a new Approved Interface or
+ exception, please contact Red Hat. You must obey the GNU General Public
+ License in all respects for all of the Red Hat elfutils code and other
+ code used in conjunction with Red Hat elfutils except the Non-GPL Code
+ covered by this exception. If you modify this file, you may extend this
+ exception to your version of the file, but you are not obligated to do
+ so. If you do not wish to provide this exception without modification,
+ you must delete this exception statement from your version and license
+ this file solely under the GPL without exception.
+
+ Red Hat elfutils is an included package of the Open Invention Network.
+ An included package of the Open Invention Network is a package for which
+ Open Invention Network licensees cross-license their patents. No patent
+ license is granted, either expressly or impliedly, by designation as an
+ included package. Should you wish to participate in the Open Invention
+ Network licensing program, please visit www.openinventionnetwork.com
+ <http://www.openinventionnetwork.com>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "cfi.h"
+#include <dwarf.h>
+#include <stdlib.h>
+
+int
+dwarf_frame_cfa (fs, ops)
+ Dwarf_Frame *fs;
+ Dwarf_Op **ops;
+{
+ /* Maybe there was a previous error. */
+ if (fs == NULL)
+ return -1;
+
+ switch (fs->cfa_rule)
+ {
+ case cfa_undefined:
+ *ops = NULL;
+ return 0;
+
+ case cfa_offset:
+ /* The Dwarf_Op was already fully initialized by execute_cfi. */
+ *ops = &fs->cfa_data.offset;
+ return 1;
+
+ case cfa_expr:
+ {
+ unsigned int address_size = (fs->cache->e_ident[EI_CLASS] == ELFCLASS32
+ ? 4 : 8);
+ size_t nops;
+
+ /* Parse the expression into internal form. */
+ int result = __libdw_intern_expression (NULL,
+ fs->cache->other_byte_order,
+ address_size,
+ &fs->cache->expr_tree,
+ &fs->cfa_data.expr,
+ ops, &nops,
+ IDX_debug_frame);
+ return result ?: (int) nops;
+ }
+
+ default:
+ abort ();
+ }
+
+ /*NOTREACHED*/
+ return -1;
+}