1#include "locale_impl.h"
2#include "stdio_impl.h"
3#include <errno.h>
4#include <wchar.h>
5
6static wint_t __fgetwc_unlocked_internal(FILE* f) {
7    mbstate_t st = {};
8    wchar_t wc;
9    int c;
10    unsigned char b;
11    size_t l;
12
13    /* Convert character from buffer if possible */
14    if (f->rpos < f->rend) {
15        l = mbrtowc(&wc, (void*)f->rpos, f->rend - f->rpos, &st);
16        if (l + 2 >= 2) {
17            f->rpos += l + !l; /* l==0 means 1 byte, null */
18            return wc;
19        }
20        if (l == -1) {
21            f->rpos++;
22            return WEOF;
23        }
24    } else
25        l = -2;
26
27    /* Convert character byte-by-byte */
28    while (l == -2) {
29        b = c = getc_unlocked(f);
30        if (c < 0) {
31            if (!mbsinit(&st))
32                errno = EILSEQ;
33            return WEOF;
34        }
35        l = mbrtowc(&wc, (void*)&b, 1, &st);
36        if (l == -1)
37            return WEOF;
38    }
39
40    return wc;
41}
42
43wint_t __fgetwc_unlocked(FILE* f) {
44    locale_t *ploc = &CURRENT_LOCALE, loc = *ploc;
45    if (f->mode <= 0)
46        fwide(f, 1);
47    *ploc = f->locale;
48    wchar_t wc = __fgetwc_unlocked_internal(f);
49    *ploc = loc;
50    return wc;
51}
52
53wint_t fgetwc(FILE* f) {
54    wint_t c;
55    FLOCK(f);
56    c = __fgetwc_unlocked(f);
57    FUNLOCK(f);
58    return c;
59}
60
61weak_alias(__fgetwc_unlocked, fgetwc_unlocked);
62weak_alias(__fgetwc_unlocked, getwc_unlocked);
63