new module 'wmemchr'

[Bruno Haible]

Hi,

For the use of the 'wwchar_t' type, some modules such as 'fnmatch' require
the usual wide string functions to be available in a variant for 'wwchar_t'.
This reminded me that gnulib does not yet have the wide string functions
(wmemchr, wstrcat, wcstok, wcswidth, etc.) available. They need to be
supported first, before we can implement the 'wwchar_t' variants.

Let's start with the 'wmemchr' function. I take the source code from the
libutf8 library that I wrote in 1999; it's simpler than the source code
found in glibc (which emphasizes all kinds of tricks for speed, such as
loop unrolling, but which makes the code less readable).


2011-02-05  Bruno Haible  <address@hidden>

        New module 'wmemchr'.
        * modules/wmemchr: New file.
        * lib/wchar.in.h (wmemchr): New declaration.
        * lib/wmemchr.c: New file.
        * lib/wmemchr-impl.h: New file, from libutf8 with modifications.
        * m4/wmemchr.m4: New file.
        * m4/wchar_h.m4 (gl_WCHAR_H_DEFAULTS): Initialize GNULIB_WMEMCHR,
        HAVE_WMEMCHR.
        * modules/wchar (Makefile.am): Substitute GNULIB_WMEMCHR, HAVE_WMEMCHR.
        * tests/test-wchar-c++.cc: Test the declaration of wmemchr.
        * doc/posix-functions/wmemchr.texi: Mention the new module.

=============================== modules/wmemchr ===============================
Description:
wmemchr() function: search wide character array for a wide character.

Files:
lib/wmemchr.c
lib/wmemchr-impl.h
m4/wmemchr.m4

Depends-on:
wchar

configure.ac:
gl_FUNC_WMEMCHR
gl_WCHAR_MODULE_INDICATOR([wmemchr])

Makefile.am:

Include:
<wchar.h>

License:
LGPL

Maintainer:
Bruno Haible
================================ lib/wmemchr.c ================================
/* Search wide character array for a wide character.
   Copyright (C) 2011 Free Software Foundation, Inc.
   Written by Bruno Haible <address@hidden>, 2011.

   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 of the License, 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, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include <wchar.h>

#include "wmemchr-impl.h"
============================= lib/wmemchr-impl.h =============================
/* Search wide character array for a wide character.
   Copyright (C) 1999, 2011 Free Software Foundation, Inc.
   Written by Bruno Haible <address@hidden>, 1999.

   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 of the License, 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, see <http://www.gnu.org/licenses/>.  */

wchar_t *
wmemchr (const wchar_t *s, wchar_t c, size_t n)
{
  for (; n > 0; s++, n--)
    {
      if (*s == c)
        return (wchar_t *) s;
    }
  return NULL;
}
================================ m4/wmemchr.m4 ================================
# wmemchr.m4 serial 1
dnl Copyright (C) 2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_WMEMCHR],
[
  AC_REPLACE_FUNCS([wmemchr])
])
===============================================================================
--- doc/posix-functions/wmemchr.texi.orig       Sat Feb  5 12:16:25 2011
+++ doc/posix-functions/wmemchr.texi    Sat Feb  5 12:08:32 2011
@@ -4,18 +4,18 @@
 
 POSIX specification:@* 
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/wmemchr.html}
 
-Gnulib module: ---
+Gnulib module: wmemchr
 
 Portability problems fixed by Gnulib:
 @itemize
address@hidden
+This function is missing on some platforms:
+HP-UX 11.00, IRIX 6.5, Solaris 2.6, Interix 3.5.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
 @item
-This function is missing on some platforms:
-HP-UX 11.00, IRIX 6.5, Solaris 2.6, Interix 3.5.
address@hidden
 On AIX and Windows platforms, @code{wchar_t} is a 16-bit type and therefore 
cannot
 accommodate all Unicode characters.
 @end itemize
--- lib/wchar.in.h.orig Sat Feb  5 12:16:25 2011
+++ lib/wchar.in.h      Sat Feb  5 11:58:36 2011
@@ -428,6 +428,22 @@
 #endif
 
 
+/* Search N wide characters of S for C.  */
+#if @GNULIB_WMEMCHR@
+# if address@hidden@
+_GL_FUNCDECL_SYS (wmemchr, wchar_t *, (const wchar_t *s, wchar_t c, size_t n));
+# endif
+_GL_CXXALIAS_SYS (wmemchr, wchar_t *, (const wchar_t *s, wchar_t c, size_t n));
+_GL_CXXALIASWARN (wmemchr);
+#elif defined GNULIB_POSIXCHECK
+# undef wmemchr
+# if HAVE_RAW_DECL_WMEMCHR
+_GL_WARN_ON_USE (wmemchr, "wmemchr is unportable - "
+                 "use gnulib module wmemchr for portability");
+# endif
+#endif
+
+
 #endif /* _GL_WCHAR_H */
 #endif /* _GL_WCHAR_H */
 #endif
--- m4/wchar_h.m4.orig  Sat Feb  5 12:16:25 2011
+++ m4/wchar_h.m4       Sat Feb  5 11:59:48 2011
@@ -7,7 +7,7 @@
 
 dnl Written by Eric Blake.
 
-# wchar_h.m4 serial 37
+# wchar_h.m4 serial 38
 
 AC_DEFUN([gl_WCHAR_H],
 [
@@ -143,6 +143,7 @@
   GNULIB_WCSRTOMBS=0;  AC_SUBST([GNULIB_WCSRTOMBS])
   GNULIB_WCSNRTOMBS=0; AC_SUBST([GNULIB_WCSNRTOMBS])
   GNULIB_WCWIDTH=0;    AC_SUBST([GNULIB_WCWIDTH])
+  GNULIB_WMEMCHR=0;    AC_SUBST([GNULIB_WMEMCHR])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_BTOWC=1;         AC_SUBST([HAVE_BTOWC])
   HAVE_MBSINIT=1;       AC_SUBST([HAVE_MBSINIT])
@@ -153,6 +154,7 @@
   HAVE_WCRTOMB=1;       AC_SUBST([HAVE_WCRTOMB])
   HAVE_WCSRTOMBS=1;     AC_SUBST([HAVE_WCSRTOMBS])
   HAVE_WCSNRTOMBS=1;    AC_SUBST([HAVE_WCSNRTOMBS])
+  HAVE_WMEMCHR=1;       AC_SUBST([HAVE_WMEMCHR])
   HAVE_DECL_WCTOB=1;    AC_SUBST([HAVE_DECL_WCTOB])
   HAVE_DECL_WCWIDTH=1;  AC_SUBST([HAVE_DECL_WCWIDTH])
   REPLACE_MBSTATE_T=0;  AC_SUBST([REPLACE_MBSTATE_T])
--- modules/wchar.orig  Sat Feb  5 12:16:25 2011
+++ modules/wchar       Sat Feb  5 12:00:26 2011
@@ -41,6 +41,7 @@
              -e 's|@''GNULIB_WCSRTOMBS''@|$(GNULIB_WCSRTOMBS)|g' \
              -e 's|@''GNULIB_WCSNRTOMBS''@|$(GNULIB_WCSNRTOMBS)|g' \
              -e 's|@''GNULIB_WCWIDTH''@|$(GNULIB_WCWIDTH)|g' \
+             -e 's|@''GNULIB_WMEMCHR''@|$(GNULIB_WMEMCHR)|g' \
              -e 's|@''HAVE_WINT_T''@|$(HAVE_WINT_T)|g' \
              -e 's|@''HAVE_BTOWC''@|$(HAVE_BTOWC)|g' \
              -e 's|@''HAVE_MBSINIT''@|$(HAVE_MBSINIT)|g' \
@@ -51,6 +52,7 @@
              -e 's|@''HAVE_WCRTOMB''@|$(HAVE_WCRTOMB)|g' \
              -e 's|@''HAVE_WCSRTOMBS''@|$(HAVE_WCSRTOMBS)|g' \
              -e 's|@''HAVE_WCSNRTOMBS''@|$(HAVE_WCSNRTOMBS)|g' \
+             -e 's|@''HAVE_WMEMCHR''@|$(HAVE_WMEMCHR)|g' \
              -e 's|@''HAVE_DECL_WCTOB''@|$(HAVE_DECL_WCTOB)|g' \
              -e 's|@''HAVE_DECL_WCWIDTH''@|$(HAVE_DECL_WCWIDTH)|g' \
              -e 's|@''REPLACE_MBSTATE_T''@|$(REPLACE_MBSTATE_T)|g' \
--- tests/test-wchar-c++.cc.orig        Sat Feb  5 12:16:26 2011
+++ tests/test-wchar-c++.cc     Sat Feb  5 12:15:20 2011
@@ -75,6 +75,11 @@
 SIGNATURE_CHECK (GNULIB_NAMESPACE::wcwidth, int, (wchar_t));
 #endif
 
+#if GNULIB_TEST_WMEMCHR
+SIGNATURE_CHECK (GNULIB_NAMESPACE::wmemchr, wchar_t *,
+                 (const wchar_t *, wchar_t, size_t));
+#endif
+
 
 int
 main ()

-- 
In memoriam Neil Aggett <http://en.wikipedia.org/wiki/Neil_Aggett>