libc/stdio/fgetwc.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10
  11
  12 #ifdef __DO_UNLOCKED
  13
  14 static void munge_stream(register FILE *stream, unsigned char *buf)
  15 {
  16         stream->__bufend = stream->__bufstart = buf;
  17         __STDIO_STREAM_INIT_BUFREAD_BUFPOS(stream);
  18         __STDIO_STREAM_DISABLE_GETC(stream);
  19         __STDIO_STREAM_DISABLE_PUTC(stream);
  20 }
  21
  22 wint_t fgetwc_unlocked(register FILE *stream)
  23 {
  24         wint_t wi;
  25         wchar_t wc[1];
  26         int n;
  27         size_t r;
  28         unsigned char sbuf[1];
  29
  30         __STDIO_STREAM_VALIDATE(stream);
  31
  32         wi = WEOF;                                      /* Prepare for failure. */
  33
  34         if (__STDIO_STREAM_IS_WIDE_READING(stream)
  35                 || !__STDIO_STREAM_TRANS_TO_READ(stream, __FLAG_WIDE)
  36                 ) {
  37                 if (stream->__modeflags & __FLAG_UNGOT) { /* Any ungetwc()s? */
  38                         if (((stream->__modeflags & 1) || stream->__ungot[1])) {
  39                                 stream->__ungot_width[0] = 0;   /* Application ungot... */
  40                         } else {                        /* scanf ungot */
  41                                 stream->__ungot_width[0] = stream->__ungot_width[1];
  42                         }
  43
  44                         wi = stream->__ungot[(stream->__modeflags--) & 1];
  45                         stream->__ungot[1] = 0;
  46                         goto DONE;
  47                 }
  48
  49                 if (!stream->__bufstart) {      /* Ugh... stream isn't buffered! */
  50                         /* Munge the stream temporarily to use a 1-byte buffer. */
  51                         munge_stream(stream, sbuf);
  52                         ++stream->__bufend;
  53                 }
  54
  55                 if (stream->__state.__mask == 0) { /* If last was a complete char */
  56                         stream->__ungot_width[0] = 0; /* then reset the width. */
  57                 }
  58
  59  LOOP:
  60                 if ((n = __STDIO_STREAM_BUFFER_RAVAIL(stream)) == 0) {
  61                         goto FILL_BUFFER;
  62                 }
  63
  64                 r = mbrtowc(wc, (const char*) stream->__bufpos, n, &stream->__state);
  65                 if (((ssize_t) r) >= 0) { /* Success... */
  66                         if (r == 0) { /* Nul wide char... means 0 byte for us so */
  67                                 ++r;     /* increment r and handle below as single. */
  68                         }
  69                         stream->__bufpos += r;
  70                         stream->__ungot_width[0] += r;
  71                         wi = *wc;
  72                         goto DONE;
  73                 }
  74
  75                 if (r == ((size_t) -2)) {
  76                         /* Potentially valid but incomplete and no more buffered. */
  77                         stream->__bufpos += n; /* Update bufpos for stream. */
  78                         stream->__ungot_width[0] += n;
  79  FILL_BUFFER:
  80                         if(__STDIO_FILL_READ_BUFFER(stream)) { /* Refill succeeded? */
  81                                 goto LOOP;
  82                         }
  83                         if (!__FERROR_UNLOCKED(stream)) { /* EOF with no error. */
  84                                 if (!stream->__state.__mask) { /* No partial wchar. */
  85                                         goto DONE;
  86                                 }
  87                                 /* EOF but partially complete wchar. */
  88                                 /* TODO: should EILSEQ be set? */
  89                                 __set_errno(EILSEQ);
  90                         }
  91                 }
  92
  93                 /* If we reach here, either r == ((size_t)-1) and mbrtowc set errno
  94                  * to EILSEQ, or r == ((size_t)-2) and stream is in an error state
  95                  * or at EOF with a partially complete wchar.  Make sure stream's
  96                  * error indicator is set. */
  97                 stream->__modeflags |= __FLAG_ERROR;
  98
  99  DONE:
 100                 if (stream->__bufstart == sbuf) { /* Need to un-munge the stream. */
 101                         munge_stream(stream, NULL);
 102                 }
 103
 104         }
 105
 106         __STDIO_STREAM_VALIDATE(stream);
 107
 108         return wi;
 109 }
 110 libc_hidden_def(fgetwc_unlocked)
 111
 112 strong_alias(fgetwc_unlocked,getwc_unlocked)
 113 #ifndef __UCLIBC_HAS_THREADS__
 114 strong_alias(fgetwc_unlocked,fgetwc)
 115 libc_hidden_def(fgetwc)
 116
 117 strong_alias(fgetwc_unlocked,getwc)
 118 #endif
 119
 120 #elif defined __UCLIBC_HAS_THREADS__
 121
 122 wint_t fgetwc(register FILE *stream)
 123 {
 124         wint_t retval;
 125         __STDIO_AUTO_THREADLOCK_VAR;
 126
 127         __STDIO_AUTO_THREADLOCK(stream);
 128
 129         retval = fgetwc_unlocked(stream);
 130
 131         __STDIO_AUTO_THREADUNLOCK(stream);
 132
 133         return retval;
 134 }
 135 libc_hidden_def(fgetwc)
 136
 137 strong_alias(fgetwc,getwc)
 138 #endif