Squashed 'third_party/elfutils/' content from commit 555e15e

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libdw/dwarf_frame_cfa.c b/libdw/dwarf_frame_cfa.c
new file mode 100644
index 0000000..07f998c
--- /dev/null
+++ b/libdw/dwarf_frame_cfa.c
@@ -0,0 +1,77 @@
+/* Get CFA expression for frame.
+   Copyright (C) 2009-2010 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "cfi.h"
+#include <dwarf.h>
+#include <stdlib.h>
+
+int
+dwarf_frame_cfa (Dwarf_Frame *fs, Dwarf_Op **ops, size_t *nops)
+{
+  /* Maybe there was a previous error.  */
+  if (fs == NULL)
+    return -1;
+
+  int result = 0;
+  switch (fs->cfa_rule)
+    {
+    case cfa_undefined:
+      *ops = NULL;
+      *nops = 0;
+      break;
+
+    case cfa_offset:
+      /* The Dwarf_Op was already fully initialized by execute_cfi.  */
+      *ops = &fs->cfa_data.offset;
+      *nops = 1;
+      break;
+
+    case cfa_expr:
+      /* Parse the expression into internal form.  */
+      result = __libdw_intern_expression
+	(NULL, fs->cache->other_byte_order,
+	 fs->cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8, 4,
+	 &fs->cache->expr_tree, &fs->cfa_data.expr, false, false,
+	 ops, nops, IDX_debug_frame);
+      break;
+
+    case cfa_invalid:
+      __libdw_seterrno (DWARF_E_INVALID_CFI);
+      result = -1;
+      break;
+
+    default:
+      abort ();
+    }
+
+  return result;
+}