glibc/wcsmbs/wcsstr.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

98 lines
2.5 KiB
C

/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library 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.
The GNU C Library 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 the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/*
* The original strstr() file contains the following comment:
*
* My personal strstr() implementation that beats most other algorithms.
* Until someone tells me otherwise, I assume that this is the
* fastest implementation of strstr() in C.
* I deliberately chose not to comment it. You should have at least
* as much fun trying to understand it, as I had to write it :-).
*
* Stephen R. van den Berg, berg@pool.informatik.rwth-aachen.de */
#include <wchar.h>
wchar_t *
wcsstr (const wchar_t *haystack, const wchar_t *needle)
{
wchar_t b, c;
if ((b = *needle) != L'\0')
{
haystack--; /* possible ANSI violation */
do
if ((c = *++haystack) == L'\0')
goto ret0;
while (c != b);
if (!(c = *++needle))
goto foundneedle;
++needle;
goto jin;
for (;;)
{
wchar_t a;
const wchar_t *rhaystack, *rneedle;
do
{
if (!(a = *++haystack))
goto ret0;
if (a == b)
break;
if ((a = *++haystack) == L'\0')
goto ret0;
shloop: ;
}
while (a != b);
jin: if (!(a = *++haystack))
goto ret0;
if (a != c)
goto shloop;
if (*(rhaystack = haystack-- + 1) == (a = *(rneedle = needle)))
do
{
if (a == L'\0')
goto foundneedle;
if (*++rhaystack != (a = *++needle))
break;
if (a == L'\0')
goto foundneedle;
}
while (*++rhaystack == (a = *++needle));
needle = rneedle; /* took the register-poor approach */
if (a == L'\0')
break;
}
}
foundneedle:
return (wchar_t*) haystack;
ret0:
return NULL;
}
/* This alias is for backward compatibility with drafts of the ISO C
standard. Unfortunately the Unix(TM) standard requires this name. */
weak_alias (wcsstr, wcswcs)