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

Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/elf_getident.c b/libelf/elf_getident.c
new file mode 100644
index 0000000..5abf8c9
--- /dev/null
+++ b/libelf/elf_getident.c
@@ -0,0 +1,61 @@
+/* Retrieve file identification data.
+   Copyright (C) 1998, 1999, 2000, 2002, 2004, 2015 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+   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 <stddef.h>
+
+#include "libelfP.h"
+
+
+char *
+elf_getident (Elf *elf, size_t *ptr)
+{
+  /* In case this is no ELF file, the handle is invalid and we return
+     NULL.  */
+  if (elf == NULL || elf->kind != ELF_K_ELF)
+    {
+      if (ptr != NULL)
+	*ptr = 0;
+      return NULL;
+    }
+
+  /* We already read the ELF header.  Return a pointer to it and store
+     the length in *PTR.  */
+  if (ptr != NULL)
+    *ptr = EI_NIDENT;
+
+  return (char *) (elf->class == ELFCLASS32
+		   || (offsetof (struct Elf, state.elf32.ehdr)
+		       == offsetof (struct Elf, state.elf64.ehdr))
+		   ? elf->state.elf32.ehdr->e_ident
+		   : elf->state.elf64.ehdr->e_ident);
+}