diff options
author | Jörg Frings-Fürst <debian@jff.email> | 2024-03-24 08:54:48 +0100 |
---|---|---|
committer | Jörg Frings-Fürst <debian@jff.email> | 2024-03-24 08:54:48 +0100 |
commit | 163a663518f33bab48b28431972e580b366b4d49 (patch) | |
tree | f518ffabaca4a0b93f0103d617e803792d3b0b43 /lib/wcsstr-impl.h | |
parent | 1b3a8d5ad2ea2f099d514d9dd51ebf926a628076 (diff) | |
parent | dd0000f7e25abe6c28d4329d324fd7fcab54094f (diff) |
Merge branch 'release/debian/1.2-1'HEADdebian/1.2-1master
Diffstat (limited to 'lib/wcsstr-impl.h')
-rw-r--r-- | lib/wcsstr-impl.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/lib/wcsstr-impl.h b/lib/wcsstr-impl.h new file mode 100644 index 00000000..b5f094e8 --- /dev/null +++ b/lib/wcsstr-impl.h @@ -0,0 +1,56 @@ +/* Locate a substring in a wide string. + Copyright (C) 1999, 2011-2024 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Eric Blake, 2008. */ + +#define AVAILABLE(h, h_l, j, n_l) \ + (!MEMCHR0 ((h) + (h_l), (j) + (n_l) - (h_l)) \ + && ((h_l) = (j) + (n_l))) +#include "wcs-two-way.h" + +RETURN_TYPE +FUNC (const UNIT *haystack_start, const UNIT *needle_start) +{ + const UNIT *haystack = haystack_start; + const UNIT *needle = needle_start; + size_t needle_len; /* Length of NEEDLE. */ + size_t haystack_len; /* Known minimum length of HAYSTACK. */ + bool ok = true; /* True if NEEDLE is prefix of HAYSTACK. */ + + /* Determine length of NEEDLE, and in the process, make sure + HAYSTACK is at least as long (no point processing all of a long + NEEDLE if HAYSTACK is too short). */ + while (*haystack && *needle) + ok &= *haystack++ == *needle++; + if (*needle) + return NULL; + if (ok) + return (RETURN_TYPE) haystack_start; + + /* Reduce the size of haystack using STRCHR, since it has a smaller + linear coefficient than the Two-Way algorithm. */ + needle_len = needle - needle_start; + haystack = STRCHR (haystack_start + 1, *needle_start); + if (!haystack || __builtin_expect (needle_len == 1, 0)) + return (RETURN_TYPE) haystack; + needle -= needle_len; + haystack_len = (haystack > haystack_start + needle_len ? 1 + : needle_len + haystack_start - haystack); + + /* Perform the search. */ + return two_way_short_needle (haystack, haystack_len, + needle, needle_len); +} |