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_getsrc_die.c b/libdw/dwarf_getsrc_die.c
new file mode 100644
index 0000000..a95179f
--- /dev/null
+++ b/libdw/dwarf_getsrc_die.c
@@ -0,0 +1,74 @@
+/* Find line information for address.
+   Copyright (C) 2004, 2005, 2014 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   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 "libdwP.h"
+#include <assert.h>
+
+
+Dwarf_Line *
+dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr)
+{
+  Dwarf_Lines *lines;
+  size_t nlines;
+
+  if (INTUSE(dwarf_getsrclines) (cudie, &lines, &nlines) != 0)
+    return NULL;
+
+  /* The lines are sorted by address, so we can use binary search.  */
+  if (nlines > 0)
+    {
+      size_t l = 0, u = nlines - 1;
+      while (l < u)
+	{
+	  size_t idx = u - (u - l) / 2;
+	  Dwarf_Line *line = &lines->info[idx];
+	  if (addr < line->addr)
+	    u = idx - 1;
+	  else
+	    l = idx;
+	}
+
+      /* This is guaranteed for us by libdw read_srclines.  */
+      assert (lines->info[nlines - 1].end_sequence);
+
+      /* The last line which is less than or equal to addr is what we
+	 want, unless it is the end_sequence which is after the
+	 current line sequence.  */
+      Dwarf_Line *line = &lines->info[l];
+      if (! line->end_sequence && line->addr <= addr)
+	return &lines->info[l];
+    }
+
+  __libdw_seterrno (DWARF_E_ADDR_OUTOFRANGE);
+  return NULL;
+}