long int ftell( struct _PDCLIB_file_t * stream )
{
- /* If offset is too large for return type, report error instead of wrong
- offset value.
- FIXME: A bit too fuzzy in the head right now; stream->ungetidx should be
- in here somewhere.
- */
- if ( stream->pos.offset > ( LONG_MAX - stream->bufidx ) )
- {
- /* integer overflow */
- _PDCLIB_errno = _PDCLIB_EINVAL;
- return -1;
- }
/* ftell() must take into account:
- the actual *physical* offset of the file, i.e. the offset as recognized
by the operating system (and stored in stream->pos.offset); and
i.e. unprocessed bytes as positive number.
That is how the somewhat obscure return-value calculation works.
*/
- return (long int)( stream->pos.offset - ( ( stream->bufend - stream->bufidx ) + stream->ungetidx ) );
+ /* If offset is too large for return type, report error instead of wrong
+ offset value.
+ */
+ /* TODO: Check what happens when ungetc() is called on a stream at offset 0 */
+ if ( ( stream->pos.offset - stream->bufend ) > ( LONG_MAX - ( stream->bufidx - stream->ungetidx ) ) )
+ {
+ /* integer overflow */
+ _PDCLIB_errno = _PDCLIB_ERANGE;
+ return -1;
+ }
+ long int res = ( stream->pos.offset - ( ( (int)stream->bufend - (int)stream->bufidx ) + stream->ungetidx ) );
+ return res;
}
#endif
FILE * fh;
TESTCASE( ( fh = tmpfile() ) != NULL );
TESTCASE( setvbuf( fh, buffer, _IOLBF, 4 ) == 0 );
+ /* Testing ungetc() at offset 0 */
+ rewind( fh );
+ TESTCASE( ungetc( 'x', fh ) == 'x' );
+ TESTCASE( ftell( fh ) == -1l );
+ rewind( fh );
+ TESTCASE( ftell( fh ) == 0l );
+ /* Commence "normal" tests */
TESTCASE( fputc( '1', fh ) == '1' );
TESTCASE( fputc( '2', fh ) == '2' );
TESTCASE( fputc( '3', fh ) == '3' );