Multibyte and wide char conversion functions. Some work still to do, but

they're quite solid now and Erik needs them for the gcc port.  Comments at
the head of wchar.c.

4 files changed, 909 insertions, 0 deletions

diff --git a/libc/misc/wchar/Makefile b/libc/misc/wchar/Makefile
new file mode 100644
index 000000000..23a1e9bba
--- /dev/null
+++ b/libc/misc/wchar/Makefile
@@ -0,0 +1,47 @@
+# Makefile for uClibc
+#
+# Copyright (C) 2000 by Lineo, inc.
+# Copyright (C) 2000,2001 Erik Andersen <andersen@uclibc.org>
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Library General Public License as published by the Free
+# Software Foundation; either version 2 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 Library General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Library General Public License
+# along with this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+# Derived in part from the Linux-8086 C library, the GNU C Library, and several
+# other sundry sources.  Files within this library are copyright by their
+# respective copyright holders.
+
+TOPDIR=../../../
+include $(TOPDIR)Rules.mak
+
+MSRC=  wchar.c
+MOBJ=  btowc.o wctob.o mbsinit.o mbrlen.o mbrtowc.o wcrtomb.o mbsrtowcs.o \
+	wcsrtombs.o _wchar_utf8sntowcs.o _wchar_wcstoutf8s.o \
+	__mbsnrtowcs.o __wcsnrtombs.o
+
+OBJS=$(MOBJ)
+
+all: $(OBJS) $(LIBC)
+
+$(LIBC): ar-target
+
+ar-target: $(OBJS)
+	$(AR) $(ARFLAGS) $(LIBC) $(OBJS)
+
+$(MOBJ): $(MSRC)
+	$(CC) $(CFLAGS) -DL_$* $< -c -o $*.o
+	$(STRIPTOOL) -x -R .note -R .comment $*.o
+
+clean:
+	rm -f *.[oa] *~ core
+
diff --git a/libc/misc/wchar/wchar.c b/libc/misc/wchar/wchar.c
new file mode 100644
index 000000000..f2d9f4a7d
--- /dev/null
+++ b/libc/misc/wchar/wchar.c
@@ -0,0 +1,723 @@
+/*  Copyright (C) 2002     Manuel Novoa III
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This 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
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*  ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!
+ *
+ *  Besides uClibc, I'm using this code in my libc for elks, which is
+ *  a 16-bit environment with a fairly limited compiler.  It would make
+ *  things much easier for me if this file isn't modified unnecessarily.
+ *  In particular, please put any new or replacement functions somewhere
+ *  else, and modify the makefile to use your version instead.
+ *  Thanks.  Manuel
+ *
+ *  ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION! */
+
+
+/* May 23, 2002     Initial Notes:
+ *
+ * I'm still tweaking this stuff, but it passes the tests I've thrown
+ * at it, and Erik needs it for the gcc port.  The glibc extension
+ * __wcsnrtombs() hasn't been tested, as I didn't find a test for it
+ * in the glibc source.  I also need to fix the behavior of
+ * _wchar_utf8sntowcs() if the max number of wchars to convert is 0.
+ *
+ * UTF-8 -> wchar -> UTF-8 conversion tests on Markus Kuhn's UTF-8-demo.txt
+ * file on my platform (x86) show about 5-10% faster conversion speed than
+ * glibc with mbsrtowcs()/wcsrtombs() and almost twice as fast as glibc with
+ * individual mbrtowc()/wcrtomb() calls.
+ *
+ * If 'DECODER' is defined, then _wchar_utf8sntowcs() will be compiled
+ * as a fail-safe UTF-8 decoder appropriate for a terminal, etc.  which
+ * needs to deal gracefully with whatever is sent to it.  In that mode,
+ * it passes Markus Kuhn's UTF-8-test.txt stress test.  I plan to add
+ * an arg to force that behavior, so the interface will be changing.
+ *
+ * I need to fix the error checking for 16-bit wide chars.  This isn't
+ * an issue for uClibc, but may be for ELKS.  I'm currently not sure
+ * if I'll use 16-bit, 32-bit, or configureable wchars in ELKS.
+ *
+ * Manuel
+ */
+
+#define _GNU_SOURCE
+#define _ISOC99_SOURCE
+#include <errno.h>
+#include <stddef.h>
+#include <limits.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <locale.h>
+#include <wchar.h>
+
+#define ENCODING (__global_locale.encoding)
+
+#if WCHAR_MAX > 0xffffU
+#define UTF_8_MAX_LEN 6
+#else
+#define UTF_8_MAX_LEN 3
+#endif
+
+/*  #define KUHN */
+
+#warning implement __CTYPE_HAS_UTF_8_LOCALES!
+#define __CTYPE_HAS_UTF_8_LOCALES
+
+/* Implementation-specific work functions. */
+
+extern size_t _wchar_utf8sntowcs(wchar_t *__restrict pwc, size_t wn,
+								 const char **__restrict src, size_t n,
+								 mbstate_t *ps, int allow_continuation);
+
+extern size_t _wchar_wcsntoutf8s(char *__restrict s, size_t n,
+								 const wchar_t **__restrict src, size_t wn);
+
+/* glibc extensions. */
+
+extern size_t __mbsnrtowcs(wchar_t *__restrict dst,
+						   const char **__restrict src,
+						   size_t NMC, size_t len, mbstate_t *__restrict ps);
+
+extern size_t __wcsnrtombs(char *__restrict dst,
+						   const wchar_t **__restrict src,
+						   size_t NWC, size_t len, mbstate_t *__restrict ps);
+
+/**********************************************************************/
+#ifdef L_btowc
+
+wint_t btowc(int c)
+{
+	wchar_t wc;
+	unsigned char buf[1];
+	mbstate_t mbstate;
+
+	if (c != EOF) {
+		*buf = (unsigned char) c;
+		mbstate.mask = 0;		/* Initialize the mbstate. */
+		if (mbrtowc(&wc, buf, 1, &mbstate) == 1) {
+			return wc;
+		}
+	}
+	return WEOF;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_wctob
+
+/* Note: We completely ignore ps in all currently supported conversions. */
+
+int wctob(wint_t c)
+{
+	unsigned char buf[MB_LEN_MAX];
+
+	return (wcrtomb(buf, c, NULL) == 1) ? *buf : EOF;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbsinit
+
+int mbsinit(const mbstate_t *ps)
+{
+	return !ps || !ps->mask;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbrlen
+
+size_t mbrlen(const char *__restrict s, size_t n, mbstate_t *__restrict ps)
+{
+	static mbstate_t mbstate;	/* Rely on bss 0-init. */
+
+	return mbrtowc(NULL, s, n, (ps != NULL) ? ps : &mbstate);
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbrtowc
+
+size_t mbrtowc(wchar_t *__restrict pwc, const char *__restrict s,
+			   size_t n, mbstate_t *__restrict ps)
+{
+	static mbstate_t mbstate;	/* Rely on bss 0-init. */
+	wchar_t wcbuf[1];
+	const char *p;
+	size_t r;
+	char empty_string[1];		/* Avoid static to be fPIC friendly. */
+
+	if (!ps) {
+		ps = &mbstate;
+	}
+
+	if (!s) {
+		pwc = (wchar_t *) s;	/* NULL */
+		empty_string[0] = 0;	/* Init the empty string when necessary. */
+		s = empty_string;
+		n = 1;
+	} else if (!n) {
+		return (ps->mask && (ps->wc == 0xffffU)) /* TODO: change error code? */
+			? ((size_t) -1) : ((size_t) -2);
+	}
+
+	p = s;
+
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+	/* Need to do this here since mbsrtowcs doesn't allow incompletes. */
+	if (ENCODING == __ctype_encoding_utf8) {
+		r = _wchar_utf8sntowcs(pwc, 1, &p, n, ps, 1);
+		return (r == 1) ? (p-s) : r;
+	}
+#endif
+
+	r = __mbsnrtowcs(wcbuf, &p, SIZE_MAX, 1, ps);
+
+	if (((ssize_t) r) >= 0) {
+		if (pwc) {
+			*pwc = *wcbuf;
+		}
+	}
+	return (size_t) r;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_wcrtomb
+
+/* Note: We completely ignore ps in all currently supported conversions. */
+/* TODO: Check for valid state anyway? */
+
+size_t wcrtomb(register char *__restrict s, wchar_t wc,
+			   mbstate_t *__restrict ps)
+{
+	wchar_t wcbuf[2];
+	const wchar_t *pwc;
+	size_t r;
+	char buf[MB_LEN_MAX];
+
+	if (!s) {
+		s = buf;
+		wc = 0;
+	}
+
+	pwc = wcbuf;
+	wcbuf[0] = wc;
+	wcbuf[1] = 0;
+
+	r = __wcsnrtombs(s, &pwc, SIZE_MAX, MB_LEN_MAX, ps);
+	return (r != 0) ? r : 1;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbsrtowcs
+
+size_t mbsrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+				 size_t len, mbstate_t *__restrict ps)
+{
+	static mbstate_t mbstate;	/* Rely on bss 0-init. */
+
+	return __mbsnrtowcs(dst, src, SIZE_MAX, len,
+						((ps != NULL) ? ps : &mbstate));
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_wcsrtombs
+
+/* Note: We completely ignore ps in all currently supported conversions.
+
+ * TODO: Check for valid state anyway? */
+
+size_t wcsrtombs(char *__restrict dst, const wchar_t **__restrict src,
+				 size_t len, mbstate_t *__restrict ps)
+{
+	return __wcsnrtombs(dst, src, SIZE_MAX, len, ps);
+}
+
+#endif
+/**********************************************************************/
+#ifdef L__wchar_utf8sntowcs
+
+/* Define DECODER to generate a UTF-8 decoder which passes Markus Kuhn's
+ * UTF-8-test.txt strss test.
+ */
+/*  #define DECODER */
+
+#ifdef DECODER
+#ifndef KUHN
+#define KUHN
+#endif
+#endif
+
+size_t _wchar_utf8sntowcs(wchar_t *__restrict pwc, size_t wn,
+						  const char **__restrict src, size_t n,
+						  mbstate_t *ps, int allow_continuation)
+{
+	register const char *s;
+	__uwchar_t mask;
+	__uwchar_t wc;
+	wchar_t wcbuf[1];
+	size_t count;
+	int incr;
+
+	s = *src;
+
+	assert(s != NULL);
+	assert(ps != NULL);
+
+	incr = 1;
+	if (!pwc) {
+		pwc = wcbuf;
+		wn = SIZE_MAX;
+		incr = 0;
+	}
+#warning fix _wchar_utf8sntowcs to allow wn == 0!
+	assert(wn > 0);				/* TODO: fix this!! */
+
+	count = wn;
+
+	if ((mask = (__uwchar_t) ps->mask) != 0) { /* A continuation... */
+#ifdef DECODER
+		wc = (__uwchar_t) ps->wc;
+		if (n) {
+			goto CONTINUE;
+		}
+		goto DONE;
+#else
+		if ((wc = (__uwchar_t) ps->wc) != 0xffffU) {
+			/* TODO: change error code here and below? */
+			if (n) {
+				goto CONTINUE;
+			}
+			goto DONE;
+		}
+		return (size_t) -1;		/* We're in an error state. */
+#endif
+	}
+
+	do {
+		if (!n) {
+			goto DONE;
+		}
+		--n;
+		if ((wc = ((unsigned char) *s++)) >= 0x80) { /* Not ASCII... */
+			mask = 0x40;
+#warning fix range for 16 bit wides
+			if ( ((unsigned char)(s[-1] - 0xc0)) < (0xfe - 0xc0) ) {
+				goto START;
+			}
+		BAD:
+#ifdef DECODER
+			wc = 0xfffd;
+			goto COMPLETE;
+#else
+			ps->mask = mask;
+			ps->wc = 0xffffU;
+			return (size_t) -1;	/* Illegal start byte! */
+#endif
+
+		CONTINUE:
+			while (n) {
+				--n;
+				if ((*s & 0xc0) != 0x80) {
+					goto BAD;
+				}
+				mask <<= 5;
+				wc <<= 6;
+				wc += (*s & 0x3f);	/* keep seperate for bcc (smaller code) */
+				++s;
+			START:
+				wc &= ~(mask << 1);
+
+				if ((wc & mask) == 0) {	/* Character completed. */
+					if ((mask >>= 5) == 0x40) {
+						mask += mask;
+					}
+					/* Check for invalid sequences (longer than necessary)
+					 * and invalid chars.  */
+					if ( (wc < mask) /* Sequence not minimal length. */
+#ifdef KUHN
+#if UTF_8_MAX_LEN == 3
+#error broken since mask can overflow!!
+						 /* For plane 0, these are the only defined values.*/
+						 || (wc > 0xfffdU)
+#else
+						 /* Note that we don't need to worry about exceeding */
+						 /* 31 bits as that is the most that UTF-8 provides. */
+						 || ( ((__uwchar_t)(wc - 0xfffeU)) < 2)
+#endif
+						 || ( ((__uwchar_t)(wc - 0xd800U)) < (0xe000U - 0xd800U) )
+#endif /* KUHN */
+						 ) {
+						goto BAD;
+					}
+					goto COMPLETE;
+				}
+			}
+			/* Character potentially valid but incomplete. */
+			if (!allow_continuation) {
+				if (count != wn) {
+					return 0;
+				}
+				/* NOTE: The following can fail if you allow and then disallow
+				 * continuation!!! */
+#if UTF_8_MAX_LEN == 3
+#error broken since mask can overflow!!
+#endif
+				/* Need to back up... */
+				do {
+					--s;
+				} while ((mask >>= 5) >= 0x40);
+				goto DONE;
+			}
+			ps->mask = (wchar_t) mask;
+			ps->wc = (wchar_t) wc;
+			*src = s;
+			return (size_t) -2;
+		}
+	COMPLETE:
+		*pwc = wc;
+		pwc += incr;
+
+	}
+#ifdef DECODER
+	while (--count);
+#else
+	while (wc && --count);
+
+	if (!wc) {
+		s = NULL;
+	}
+#endif
+
+ DONE:
+	/* ps->wc is irrelavent here. */
+	ps->mask = 0;
+	if (pwc != wcbuf) {
+		*src = s;
+	}
+
+	return wn - count;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L__wchar_wcstoutf8s
+
+size_t _wchar_wcsntoutf8s(char *__restrict s, size_t n,
+						  const wchar_t **__restrict src, size_t wn)
+{
+	register char *p;
+	size_t len, t;
+	__uwchar_t wc;
+	const __uwchar_t *swc;
+	int store;
+	char buf[MB_LEN_MAX];
+	char m;
+
+	store = 1;
+	if (!s) {
+		s = buf;
+		n = SIZE_MAX;
+		store = 0;
+	}
+
+	t = n;
+	swc = (const __uwchar_t *) *src;
+
+	assert(swc != NULL);
+
+	while (wn && t) {
+		wc = *swc;
+
+		*s = wc;
+		len = 1;
+
+		if (wc >= 0x80) {
+#ifdef KUHN
+			if (
+#if UTF_8_MAX_LEN == 3
+				/* For plane 0, these are the only defined values.*/
+				/* Note that we don't need to worry about exceeding */
+				/* 31 bits as that is the most that UTF-8 provides. */
+				(wc > 0xfffdU)
+#else
+				/* UTF_8_MAX_LEN == 6 */
+				(wc > 0x7fffffffUL)
+				|| ( ((__uwchar_t)(wc - 0xfffeU)) < 2)
+#endif
+				|| ( ((__uwchar_t)(wc - 0xd800U)) < (0xe000U - 0xd800U) )
+				) {
+				return (size_t) -1;
+			}
+#else  /* KUHN */
+#if UTF_8_MAX_LEN != 3
+			if (wc > 0x7fffffffUL) { /* Value too large. */
+				return (size_t) -1;
+			}
+#endif
+#endif /* KUHN */
+
+			wc >>= 1;
+			p = s;
+			do {
+				++p;
+			} while (wc >>= 5);
+			wc = *swc;
+			if ((len = p - s) > t) { /* Not enough space. */
+				break;
+			}
+
+			m = 0x80;
+			while( p>s ) {
+				m = (m >> 1) | 0x80;
+				*--p = (wc & 0x3f) | 0x80;
+				wc >>= 6;
+			}
+			*s |= (m << 1);
+		} else if (wc == 0) {	/* End of string. */
+			swc = NULL;
+			break;
+		}
+
+		++swc;
+		--wn;
+		t -= len;
+		if (store) {
+			s += len;
+		}
+	}
+
+	*src = (const wchar_t *) swc;
+
+	return n - t;
+}
+
+
+#endif
+/**********************************************************************/
+#ifdef L___mbsnrtowcs
+
+/* WARNING: We treat len as SIZE_MAX when dst is NULL! */
+
+size_t mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+				  size_t NMC, size_t len, mbstate_t *__restrict ps)
+	 __attribute__ ((__weak__, __alias__("__mbsnrtowcs")));
+
+size_t __mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+					size_t NMC, size_t len, mbstate_t *__restrict ps)
+{
+	static mbstate_t mbstate;	/* Rely on bss 0-init. */
+	wchar_t wcbuf[1];
+	const char *s;
+	size_t count, r;
+	int incr;
+
+	if (!ps) {
+		ps = &mbstate;
+	}
+
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+	if (ENCODING == __ctype_encoding_utf8) {
+		return ((r = _wchar_utf8sntowcs(dst, len, src, NMC, ps, 1))
+				!= (size_t) -2) ? r : 0;
+	}
+#endif
+	incr = 1;
+	if (!dst) {
+		dst = wcbuf;
+		len = SIZE_MAX;
+		incr = 0;
+	}
+
+	/* Since all the following encodings are single-byte encodings... */
+	if (len > NMC) {
+		len = NMC;
+	}
+
+	count = len;
+	s = *src;
+
+#ifdef __CTYPE_HAS_8_BIT_LOCALES
+	if (ENCODING == __ctype_encoding_8_bit) {
+		wchar_t wc;
+		while (count) {
+			if ((wc = ((unsigned char)(*s))) >= 0x80) {	/* Non-ASCII... */
+				wc -= 0x80;
+				wc = __global_locale.tbl8c2wc[
+						  (__global_locale.idx8c2wc[wc >> Cc2wc_IDX_SHIFT]
+						   << Cc2wc_IDX_SHIFT) + (wc & (Cc2wc_ROW_LEN - 1))];
+				if (!wc) {
+					goto BAD;
+				}
+			} else if (!wc) {
+				s = NULL;
+				break;
+			}
+			++s;
+			*dst = wc;
+			dst += incr;
+			--count;
+		}
+		if (dst != wcbuf) {
+			*src = s;
+		}
+		return len - count;
+	}
+#endif
+
+	assert(ENCODING == __ctype_encoding_7_bit);
+
+	while (count) {
+		if ((*dst = (unsigned char) *s) == 0) {
+			s = NULL;
+			break;
+		}
+		if (*dst >= 0x80) {
+#ifdef __CTYPE_HAS_8_BIT_LOCALES
+		BAD:
+#endif
+			__set_errno(EILSEQ);
+			return (size_t) -1;
+		}
+		++s;
+		dst += incr;
+		--count;
+	}
+	if (dst != wcbuf) {
+		*src = s;
+	}
+	return len - count;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L___wcsnrtombs
+
+/* WARNING: We treat len as SIZE_MAX when dst is NULL! */
+
+/* Note: We completely ignore ps in all currently supported conversions.
+ * TODO: Check for valid state anyway? */
+
+size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
+				  size_t NWC, size_t len, mbstate_t *__restrict ps)
+	 __attribute__ ((__weak__, __alias__("__wcsnrtombs")));
+
+size_t __wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
+					size_t NWC, size_t len, mbstate_t *__restrict ps)
+{
+	const __uwchar_t *s;
+	size_t count;
+	int incr;
+	char buf[MB_LEN_MAX];
+
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+	if (ENCODING == __ctype_encoding_utf8) {
+		return _wchar_wcsntoutf8s(dst, len, src, NWC);
+	}
+#endif
+
+	incr = 1;
+	if (!dst) {
+		dst = buf;
+		len = SIZE_MAX;
+		incr = 0;
+	}
+
+	/* Since all the following encodings are single-byte encodings... */
+	if (len > NWC) {
+		len = NWC;
+	}
+
+	count = len;
+	s = (const __uwchar_t *) *src;
+
+#ifdef __CTYPE_HAS_8_BIT_LOCALES
+	if (ENCODING == __ctype_encoding_8_bit) {
+		__uwchar_t wc;
+		__uwchar_t u;
+		while (count) {
+			if ((wc = *s) <= 0x7f) {
+				if (!(*dst = (unsigned char) wc)) {
+					s = NULL;
+					break;
+				}
+			} else {
+				u = 0;
+				if (wc <= Cwc2c_DOMAIN_MAX) {
+					u = __global_locale.idx8wc2c[wc >> (Cwc2c_TI_SHIFT
+														+ Cwc2c_TT_SHIFT)];
+					u = __global_locale.tbl8wc2c[(u << Cwc2c_TI_SHIFT)
+									+ ((wc >> Cwc2c_TT_SHIFT)
+									   & ((1 << Cwc2c_TI_SHIFT)-1))];
+					u = __global_locale.tbl8wc2c[Cwc2c_TI_LEN
+									+ (u << Cwc2c_TT_SHIFT)
+									+ (wc & ((1 << Cwc2c_TT_SHIFT)-1))];
+				}
+
+/*  #define __WCHAR_REPLACEMENT_CHAR '?' */
+#ifdef __WCHAR_REPLACEMENT_CHAR
+				*dst = (unsigned char) ( u ? u : __WCHAR_REPLACEMENT_CHAR );
+#else
+				if (!u) {
+					goto BAD;
+				}
+				*dst = (unsigned char) u;
+#endif
+			}
+			++s;
+			dst += incr;
+			--count;
+		}
+		if (dst != buf) {
+			*src = (const wchar_t *) s;
+		}
+		return len - count;
+	}
+#endif
+
+	assert(ENCODING == __ctype_encoding_7_bit);
+
+	while (count) {
+		if (*s >= 0x80) {
+#if defined(__CTYPE_HAS_8_BIT_LOCALES) && !defined(__WCHAR_REPLACEMENT_CHAR)
+		BAD:
+#endif
+			__set_errno(EILSEQ);
+			return (size_t) -1;
+
+		}
+		if ((*dst = (unsigned char) *s) == 0) {
+			s = NULL;
+			break;
+		}
+		++s;
+		dst += incr;
+		--count;
+	}
+	if (dst != buf) {
+		*src = (const wchar_t *) s;
+	}
+	return len - count;
+}
+
+#endif
+/**********************************************************************/
diff --git a/libc/stdlib/Makefile b/libc/stdlib/Makefile
index 64ae75d18..e69ec4ea8 100644
--- a/libc/stdlib/Makefile
+++ b/libc/stdlib/Makefile
@@ -35,6 +35,12 @@ ifeq ($(HAS_LONG_LONG),true)
 	MOBJ +=  llabs.o atoll.o strtoll.o strtoull.o _stdlib_strto_ll.o
 endif
 
+ifeq ($(HAS_WCHAR),true)
+	MOBJ += mblen.o mbtowc.o wctomb.o mbstowcs.o wcstombs.o \
+		_stdlib_mb_cur_max.o 
+endif
+
+
 MSRC2=atexit.c
 MOBJ2=atexit.o on_exit.o __exit_handler.o exit.o
 
diff --git a/libc/stdlib/stdlib.c b/libc/stdlib/stdlib.c
index 1cd350c31..4c9e8f039 100644
--- a/libc/stdlib/stdlib.c
+++ b/libc/stdlib/stdlib.c
@@ -623,3 +623,136 @@ void ssort (void  *base,
 
 #endif
 /**********************************************************************/
+/* Multibyte and wchar stuff follows. */
+
+#ifdef __UCLIBC_HAS_WCHAR__
+
+#include <locale.h>
+#include <wchar.h>
+
+/* TODO: clean up the following... */
+
+#if WCHAR_MAX > 0xffffU
+#define UTF_8_MAX_LEN 6
+#else
+#define UTF_8_MAX_LEN 3
+#endif
+
+#define ENCODING (__global_locale.encoding)
+
+#endif
+
+/**********************************************************************/
+#ifdef L__stdlib_mb_cur_max
+
+size_t _stdlib_mb_cur_max(void)
+{
+	return __global_locale.mb_cur_max;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mblen
+
+#warning implement __CTYPE_HAS_UTF_8_LOCALES!
+#define __CTYPE_HAS_UTF_8_LOCALES
+
+int mblen(register const char *s, size_t n)
+{
+	static mbstate_t state;
+	size_t r;
+
+	if (!s) {
+		state.mask = 0;
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+		return ENCODING == __ctype_encoding_utf8;
+#else
+		return 0;
+#endif
+	}
+
+	if ((r = mbrlen(s, n, &state)) == (size_t) -2) {
+		/* TODO: Should we set an error state? */
+		state.wc = 0xffffU;		/* Make sure we're in an error state. */
+		return (size_t) -1;		/* TODO: Change error code above? */
+	}
+	return r;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbtowc
+
+#warning implement __CTYPE_HAS_UTF_8_LOCALES!
+#define __CTYPE_HAS_UTF_8_LOCALES
+
+int mbtowc(wchar_t *__restrict pwc, register const char *__restrict s, size_t n)
+{
+	static mbstate_t state;
+	size_t r;
+
+	if (!s) {
+		state.mask = 0;
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+		return ENCODING == __ctype_encoding_utf8;
+#else
+		return 0;
+#endif
+	}
+
+	if ((r = mbrtowc(pwc, s, n, &state)) == (size_t) -2) {
+		/* TODO: Should we set an error state? */
+		state.wc = 0xffffU;		/* Make sure we're in an error state. */
+		return (size_t) -1;		/* TODO: Change error code above? */
+	}
+	return r;
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_wctomb
+
+#warning implement __CTYPE_HAS_UTF_8_LOCALES!
+#define __CTYPE_HAS_UTF_8_LOCALES
+
+/* Note: We completely ignore state in all currently supported conversions. */
+
+int wctomb(register char *__restrict s, wchar_t swc)
+{
+	return (!s)
+		?
+#ifdef __CTYPE_HAS_UTF_8_LOCALES
+		(ENCODING == __ctype_encoding_utf8)
+#else
+		0						/* Encoding is stateless. */
+#endif
+		: ((ssize_t) wcrtomb(s, swc, NULL));
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_mbstowcs
+
+size_t mbstowcs(wchar_t * __restrict pwcs, const char * __restrict s, size_t n)
+{
+	mbstate_t state;
+
+	state.mask = 0;				/* Always start in initial shift state. */
+
+	return mbsrtowcs(pwcs, &s, n, &state);
+}
+
+#endif
+/**********************************************************************/
+#ifdef L_wcstombs
+
+/* Note: We completely ignore state in all currently supported conversions. */
+
+size_t wcstombs(char * __restrict s, const wchar_t * __restrict pwcs, size_t n)
+{
+	return wcsrtombs(s, &pwcs, n, NULL);
+}
+
+#endif
+/**********************************************************************/
+