1 files changed, 121 insertions, 0 deletions
diff --git a/src/multibyte/mbsrtowcs.c b/src/multibyte/mbsrtowcs.c
new file mode 100644
index 00000000..e2b43480
--- /dev/null
+++ b/src/multibyte/mbsrtowcs.c
@@ -0,0 +1,121 @@
+/* 
+ * This code was written by Rich Felker in 2010; no copyright is claimed.
+ * This code is in the public domain. Attribution is appreciated but
+ * unnecessary.
+ */
+
+#include <stdlib.h>
+#include <inttypes.h>
+#include <wchar.h>
+#include <errno.h>
+
+#include "internal.h"
+
+size_t mbsrtowcs(wchar_t *ws, const char **src, size_t wn, mbstate_t *st)
+{
+	unsigned c;
+	const unsigned char *s = *src;
+	const wchar_t *wsorig = ws;
+
+	if (!st) st = (void *)&c, c = 0;
+	else c = *(unsigned *)st;
+
+	if (c) {
+		*(unsigned *)st = 0;
+		if (!ws) {
+			wn = 0;
+			goto resume0;
+		}
+		goto resume;
+	}
+
+	if (!ws) for (wn=0;;) {
+		if ((unsigned)*s-SA >= SB-SA) {
+			while (((unsigned)s&3) && (unsigned)*s-1<0x7f) s++, wn++;
+			while (!(( *(uint32_t*)s | *(uint32_t*)s-0x01010101) & 0x80808080)) s+=4, wn+=4;
+			while ((unsigned)*s-1<0x7f) s++, wn++;
+			if (!*s) return wn;
+			if ((unsigned)*s-SA >= SB-SA) goto ilseq2;
+		}
+		c = bittab[*s++-SA];
+		do {
+resume0:
+			if (OOB(c,*s)) goto ilseq2; s++;
+			c <<= 6; if (!(c&(1U<<31))) break;
+#ifdef I_FAILED_TO_RTFM_RFC3629
+			if ((unsigned)*s++-0x80 >= 0x40) goto ilseq2;
+			c <<= 6; if (!(c&(1U<<31))) break;
+			if ((unsigned)*s++-0x80 >= 0x40) goto ilseq2;
+			c <<= 6; if (!(c&(1U<<31))) break;
+#endif
+			if ((unsigned)*s++-0x80 >= 0x40) goto ilseq2;
+			c <<= 6; if (!(c&(1U<<31))) break;
+			if ((unsigned)*s++-0x80 >= 0x40) goto ilseq2;
+		} while (0);
+		wn++; c = 0;
+	}
+
+	while (wn) {
+		if ((unsigned)*s-SA >= SB-SA) {
+			if (wn >= 7) {
+				while (((unsigned)s&3) && (unsigned)*s-1<0x7f) {
+					*ws++ = *s++;
+					wn--;
+				}
+				while (wn>=4 && !(( *(uint32_t*)s | *(uint32_t*)s-0x01010101) & 0x80808080)) {
+					*ws++ = *s++;
+					*ws++ = *s++;
+					*ws++ = *s++;
+					*ws++ = *s++;
+					wn -= 4;
+				}
+			}
+			while (wn && (unsigned)*s-1<0x7f) {
+				*ws++ = *s++;
+				wn--;
+			}
+			if (!wn) break;
+			if (!*s) {
+				*ws = 0;
+				*src = 0;
+				return ws-wsorig;
+			}
+			if ((unsigned)*s-SA >= SB-SA) goto ilseq;
+		}
+		c = bittab[*s++-SA];
+		do {
+resume:
+			if (OOB(c,*s)) goto ilseq;
+			c = (c<<6) | *s++-0x80;
+			if (!(c&(1U<<31))) break;
+
+#ifdef I_FAILED_TO_RTFM_RFC3629
+			if ((unsigned)*s-0x80 >= 0x40) goto ilseq;
+			c = (c<<6) | *s++-0x80;
+			if (!(c&(1U<<31))) break;
+
+			if ((unsigned)*s-0x80 >= 0x40) goto ilseq;
+			c = (c<<6) | *s++-0x80;
+			if (!(c&(1U<<31))) break;
+#endif
+
+			if ((unsigned)*s-0x80 >= 0x40) goto ilseq;
+			c = (c<<6) | *s++-0x80;
+			if (!(c&(1U<<31))) break;
+
+			if ((unsigned)*s-0x80 >= 0x40) goto ilseq;
+			c = (c<<6) | *s++-0x80;
+		} while (0);
+
+		*ws++ = c; wn--; c = 0;
+	}
+	*src = s;
+	return ws-wsorig;
+ilseq:
+	*src = s;
+ilseq2:
+	/* enter permanently failing state */
+	*(unsigned *)st = FAILSTATE;
+	errno = EILSEQ;
+	return -1;
+}