Merge GDB 7.5.1

gdb/gnulib/memmem.c

-/* Copyright (C) 1991, 1992, 1993, 1994, 1996, 1997, 1998, 2000, 2004, 2007,
-   2008, 2009, 2010, 2011 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   This program 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; either version 3, or (at your option)
-   any later version.
-
-   This program 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 this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
-
-/* This particular implementation was written by Eric Blake, 2008.  */
-
-#ifndef _LIBC
-# include <config.h>
-#endif
-
-/* Specification of memmem.  */
-#include <string.h>
-
-#ifndef _LIBC
-# define __builtin_expect(expr, val)   (expr)
-#endif
-
-#define RETURN_TYPE void *
-#define AVAILABLE(h, h_l, j, n_l) ((j) <= (h_l) - (n_l))
-#include "str-two-way.h"
-
-/* Return the first occurrence of NEEDLE in HAYSTACK.  Return HAYSTACK
-   if NEEDLE_LEN is 0, otherwise NULL if NEEDLE is not found in
-   HAYSTACK.  */
-void *
-memmem (const void *haystack_start, size_t haystack_len,
-        const void *needle_start, size_t needle_len)
-{
-  /* Abstract memory is considered to be an array of 'unsigned char' values,
-     not an array of 'char' values.  See ISO C 99 section 6.2.6.1.  */
-  const unsigned char *haystack = (const unsigned char *) haystack_start;
-  const unsigned char *needle = (const unsigned char *) needle_start;
-
-  if (needle_len == 0)
-    /* The first occurrence of the empty string is deemed to occur at
-       the beginning of the string.  */
-    return (void *) haystack;
-
-  /* Sanity check, otherwise the loop might search through the whole
-     memory.  */
-  if (__builtin_expect (haystack_len < needle_len, 0))
-    return NULL;
-
-  /* Use optimizations in memchr when possible, to reduce the search
-     size of haystack using a linear algorithm with a smaller
-     coefficient.  However, avoid memchr for long needles, since we
-     can often achieve sublinear performance.  */
-  if (needle_len < LONG_NEEDLE_THRESHOLD)
-    {
-      haystack = memchr (haystack, *needle, haystack_len);
-      if (!haystack || __builtin_expect (needle_len == 1, 0))
-        return (void *) haystack;
-      haystack_len -= haystack - (const unsigned char *) haystack_start;
-      if (haystack_len < needle_len)
-        return NULL;
-      return two_way_short_needle (haystack, haystack_len, needle, needle_len);
-    }
-  else
-    return two_way_long_needle (haystack, haystack_len, needle, needle_len);
-}
-
-#undef LONG_NEEDLE_THRESHOLD