1#include <stdint.h>
  2#include <wchar.h>
  3#include <errno.h>
  4#include <string.h>
  5#include <stdlib.h>
  6#include "internal.h"
  7
  8size_t mbsrtowcs(wchar_t *restrict ws, const char **restrict src, size_t wn, mbstate_t *restrict st)
  9{
 10	const unsigned char *s = (const void *)*src;
 11	size_t wn0 = wn;
 12	unsigned c = 0;
 13
 14	if (st && (c = *(unsigned *)st)) {
 15		if (ws) {
 16			*(unsigned *)st = 0;
 17			goto resume;
 18		} else {
 19			goto resume0;
 20		}
 21	}
 22
 23	if (MB_CUR_MAX==1) {
 24		if (!ws) return strlen((const char *)s);
 25		for (;;) {
 26			if (!wn) {
 27				*src = (const void *)s;
 28				return wn0;
 29			}
 30			if (!*s) break;
 31			c = *s++;
 32			*ws++ = CODEUNIT(c);
 33			wn--;
 34		}
 35		*ws = 0;
 36		*src = 0;
 37		return wn0-wn;
 38	}
 39
 40	if (!ws) for (;;) {
 41#ifdef __GNUC__
 42		typedef uint32_t __attribute__((__may_alias__)) w32;
 43		if (*s-1u < 0x7f && (uintptr_t)s%4 == 0) {
 44			while (!(( *(w32*)s | *(w32*)s-0x01010101) & 0x80808080)) {
 45				s += 4;
 46				wn -= 4;
 47			}
 48		}
 49#endif
 50		if (*s-1u < 0x7f) {
 51			s++;
 52			wn--;
 53			continue;
 54		}
 55		if (*s-SA > SB-SA) break;
 56		c = bittab[*s++-SA];
 57resume0:
 58		if (OOB(c,*s)) { s--; break; }
 59		s++;
 60		if (c&(1U<<25)) {
 61			if (*s-0x80u >= 0x40) { s-=2; break; }
 62			s++;
 63			if (c&(1U<<19)) {
 64				if (*s-0x80u >= 0x40) { s-=3; break; }
 65				s++;
 66			}
 67		}
 68		wn--;
 69		c = 0;
 70	} else for (;;) {
 71		if (!wn) {
 72			*src = (const void *)s;
 73			return wn0;
 74		}
 75#ifdef __GNUC__
 76		typedef uint32_t __attribute__((__may_alias__)) w32;
 77		if (*s-1u < 0x7f && (uintptr_t)s%4 == 0) {
 78			while (wn>=5 && !(( *(w32*)s | *(w32*)s-0x01010101) & 0x80808080)) {
 79				*ws++ = *s++;
 80				*ws++ = *s++;
 81				*ws++ = *s++;
 82				*ws++ = *s++;
 83				wn -= 4;
 84			}
 85		}
 86#endif
 87		if (*s-1u < 0x7f) {
 88			*ws++ = *s++;
 89			wn--;
 90			continue;
 91		}
 92		if (*s-SA > SB-SA) break;
 93		c = bittab[*s++-SA];
 94resume:
 95		if (OOB(c,*s)) { s--; break; }
 96		c = (c<<6) | *s++-0x80;
 97		if (c&(1U<<31)) {
 98			if (*s-0x80u >= 0x40) { s-=2; break; }
 99			c = (c<<6) | *s++-0x80;
100			if (c&(1U<<31)) {
101				if (*s-0x80u >= 0x40) { s-=3; break; }
102				c = (c<<6) | *s++-0x80;
103			}
104		}
105		*ws++ = c;
106		wn--;
107		c = 0;
108	}
109
110	if (!c && !*s) {
111		if (ws) {
112			*ws = 0;
113			*src = 0;
114		}
115		return wn0-wn;
116	}
117	errno = EILSEQ;
118	if (ws) *src = (const void *)s;
119	return -1;
120}