libc-top-half/musl/src/stdio/fgetwc.c

   1 #include "stdio_impl.h"
   2 #include "locale_impl.h"
   3 #include <wchar.h>
   4 #include <errno.h>
   5
   6 static wint_t __fgetwc_unlocked_internal(FILE *f)
   7 {
   8         wchar_t wc;
   9         int c;
  10         size_t l;
  11
  12         /* Convert character from buffer if possible */
  13         if (f->rpos != f->rend) {
  14                 l = mbtowc(&wc, (void *)f->rpos, f->rend - f->rpos);
  15                 if (l+1 >= 1) {
  16                         f->rpos += l + !l; /* l==0 means 1 byte, null */
  17                         return wc;
  18                 }
  19         }
  20
  21         /* Convert character byte-by-byte */
  22         mbstate_t st = { 0 };
  23         unsigned char b;
  24         int first = 1;
  25         do {
  26                 b = c = getc_unlocked(f);
  27                 if (c < 0) {
  28                         if (!first) {
  29                                 f->flags |= F_ERR;
  30                                 errno = EILSEQ;
  31                         }
  32                         return WEOF;
  33                 }
  34                 l = mbrtowc(&wc, (void *)&b, 1, &st);
  35                 if (l == -1) {
  36                         if (!first) {
  37                                 f->flags |= F_ERR;
  38                                 ungetc(b, f);
  39                         }
  40                         return WEOF;
  41                 }
  42                 first = 0;
  43         } while (l == -2);
  44
  45         return wc;
  46 }
  47
  48 wint_t __fgetwc_unlocked(FILE *f)
  49 {
  50         locale_t *ploc = &CURRENT_LOCALE, loc = *ploc;
  51         if (f->mode <= 0) fwide(f, 1);
  52         *ploc = f->locale;
  53         wchar_t wc = __fgetwc_unlocked_internal(f);
  54         *ploc = loc;
  55         return wc;
  56 }
  57
  58 wint_t fgetwc(FILE *f)
  59 {
  60         wint_t c;
  61         FLOCK(f);
  62         c = __fgetwc_unlocked(f);
  63         FUNLOCK(f);
  64         return c;
  65 }
  66
  67 weak_alias(__fgetwc_unlocked, fgetwc_unlocked);
  68 weak_alias(__fgetwc_unlocked, getwc_unlocked);