crt/stdio/fseeki64: Copy-n-paste from `f{tell,seek}o64()`
The old implementation of `_ftelli64()` was introduced in 518dd33c326 in
2007. However it sometimes reports incorrect values. This program, after
being compiled with `i686-w64-mingw32-gcc`, outputs `-15` on the second
line on my Windows 7 Professional:
#include <stdio.h>
#include <assert.h>
int main(void)
{
FILE* fp = fopen(__FILE__, "rb");
assert(fp);
printf("offset = %lld\n", (long long)_ftelli64(fp));
char buf[1];
ssize_t nread = fread(&buf, 1, 1, fp);
assert(nread == 1);
printf("offset = %lld\n", (long long)_ftelli64(fp));
fclose(fp);
}
This is apparently incorrect, as file offsets can't be negative.
If it was compiled with `x86_64-w64-mingw32-gcc`, it however outputs `1`
as expected.
Since 4d3b28a992, we have had 64-bit tell/seek functions. They should be
used to de-duplicate these implementations.
Signed-off-by: Liu Hao <lh_mouse@126.com>
diff --git a/mingw-w64-crt/stdio/fseeki64.c b/mingw-w64-crt/stdio/fseeki64.c
index fdb8f1c..f70062e 100644
--- a/mingw-w64-crt/stdio/fseeki64.c
+++ b/mingw-w64-crt/stdio/fseeki64.c
@@ -6,172 +6,45 @@
#include <stdio.h>
#include <io.h>
#include <errno.h>
-#include <internal.h>
-
-#define _IOYOURBUF 0x0100
-#define _IOSETVBUF 0x0400
-#define _IOFEOF 0x0800
-#define _IOFLRTN 0x1000
-#define _IOCTRLZ 0x2000
-#define _IOCOMMIT 0x4000
-
-/* General use macros */
-
-#define inuse(s) ((s)->_flag & (_IOREAD|_IOWRT|_IORW))
-#define mbuf(s) ((s)->_flag & _IOMYBUF)
-#define nbuf(s) ((s)->_flag & _IONBF)
-#define ybuf(s) ((s)->_flag & _IOYOURBUF)
-#define bigbuf(s) ((s)->_flag & (_IOMYBUF|_IOYOURBUF))
-#define anybuf(s) ((s)->_flag & (_IOMYBUF|_IONBF|_IOYOURBUF))
-
-#define _INTERNAL_BUFSIZ 4096
-#define _SMALL_BUFSIZ 512
-
-#define FOPEN 0x01 /* file handle open */
-#define FEOFLAG 0x02 /* end of file has been encountered */
-#define FCRLF 0x04 /* CR-LF across read buffer (in text mode) */
-#define FPIPE 0x08 /* file handle refers to a pipe */
-#define FNOINHERIT 0x10 /* file handle opened _O_NOINHERIT */
-#define FAPPEND 0x20 /* file handle opened O_APPEND */
-#define FDEV 0x40 /* file handle refers to device */
-#define FTEXT 0x80 /* file handle is in text mode */
-
-_CRTIMP __int64 __cdecl _lseeki64(int fh,__int64 pos,int mthd);
-__int64 __cdecl _ftelli64(FILE *str);
#if !defined(__arm__) && !defined(__aarch64__) /* we have F_ARM_ANY(_fseeki64) in msvcrt.def.in */
-int __cdecl _flush (FILE *str);
-
-int __cdecl _flush (FILE *str)
+int __cdecl _fseeki64(FILE* stream, __int64 offset, int whence)
{
- FILE *stream;
- int rc = 0; /* assume good return */
- __int64 nchar;
-
- stream = str;
- if ((stream->_flag & (_IOREAD | _IOWRT)) == _IOWRT && bigbuf(stream)
- && (nchar = (__int64) (stream->_ptr - stream->_base)) > 0ll)
- {
- if ( _write(_fileno(stream), stream->_base, nchar) == nchar) {
- if (_IORW & stream->_flag)
- stream->_flag &= ~_IOWRT;
- } else {
- stream->_flag |= _IOERR;
- rc = EOF;
+ fpos_t pos;
+ if (whence == SEEK_CUR)
+ {
+ /* If stream is invalid, fgetpos sets errno. */
+ if (fgetpos (stream, &pos))
+ return (-1);
+ pos += (fpos_t) offset;
}
- }
- stream->_ptr = stream->_base;
- stream->_cnt = 0ll;
- return rc;
+ else if (whence == SEEK_END)
+ {
+ /* If writing, we need to flush before getting file length. */
+ fflush (stream);
+ pos = (fpos_t) (_filelengthi64 (_fileno (stream)) + offset);
+ }
+ else if (whence == SEEK_SET)
+ pos = (fpos_t) offset;
+ else
+ {
+ errno = EINVAL;
+ return (-1);
+ }
+ return fsetpos (stream, &pos);
}
-int __cdecl _fseeki64(FILE *str,__int64 offset,int whence)
-{
- FILE *stream;
- /* Init stream pointer */
- stream = str;
- errno=0;
- if(!stream || ((whence != SEEK_SET) && (whence != SEEK_CUR) && (whence != SEEK_END)))
- {
- errno=EINVAL;
- return -1;
- }
- /* Clear EOF flag */
- stream->_flag &= ~_IOEOF;
-
- if (whence == SEEK_CUR) {
- offset += _ftelli64(stream);
- whence = SEEK_SET;
- }
- /* Flush buffer as necessary */
- _flush(stream);
-
- /* If file opened for read/write, clear flags since we don't know
- what the user is going to do next. If the file was opened for
- read access only, decrease _bufsiz so that the next _filbuf
- won't cost quite so much */
-
- if (stream->_flag & _IORW)
- stream->_flag &= ~(_IOWRT|_IOREAD);
- else if ( (stream->_flag & _IOREAD) && (stream->_flag & _IOMYBUF) &&
- !(stream->_flag & _IOSETVBUF) )
- stream->_bufsiz = _SMALL_BUFSIZ;
-
- /* Seek to the desired locale and return. */
-
- return (_lseeki64(_fileno(stream), offset, whence) == -1ll ? -1 : 0);
-}
-
-int __cdecl (*__MINGW_IMP_SYMBOL(_fseeki64))(FILE *, __int64, int) = _fseeki64;
+int __cdecl (*__MINGW_IMP_SYMBOL(_fseeki64))(FILE*, __int64, int) = _fseeki64;
#endif /* !defined(__arm__) && !defined(__aarch64__) */
-__int64 __cdecl _ftelli64(FILE *str)
+__int64 __cdecl _ftelli64(FILE* stream)
{
- FILE *stream;
- size_t offset;
- __int64 filepos;
- register char *p;
- char *max;
- int fd;
- size_t rdcnt = 0;
-
- errno=0;
- stream = str;
- fd = _fileno(stream);
- if (stream->_cnt < 0ll) stream->_cnt = 0ll;
- if ((filepos = _lseeki64(fd, 0ll, SEEK_CUR)) < 0L)
- return -1ll;
-
- if (!bigbuf(stream)) /* _IONBF or no buffering designated */
- return (filepos - (__int64) stream->_cnt);
-
- offset = (size_t)(stream->_ptr - stream->_base);
-
- if (stream->_flag & (_IOWRT|_IOREAD))
- {
- if (_osfile(fd) & FTEXT)
- for (p = stream->_base; p < stream->_ptr; p++)
- if (*p == '\n') /* adjust for '\r' */
- offset++;
- }
- else if (!(stream->_flag & _IORW)) {
- errno=EINVAL;
- return -1ll;
- }
- if (filepos == 0ll)
- return ((__int64)offset);
-
- if (stream->_flag & _IOREAD) /* go to preceding sector */
- {
- if (stream->_cnt == 0ll) /* filepos holds correct location */
- offset = 0ll;
- else
- {
- rdcnt = ((size_t) stream->_cnt) + ((size_t) (size_t)(stream->_ptr - stream->_base));
- if (_osfile(fd) & FTEXT) {
- if (_lseeki64(fd, 0ll, SEEK_END) == filepos) {
- max = stream->_base + rdcnt;
- for (p = stream->_base; p < max; p++)
- if (*p == '\n') /* adjust for '\r' */
- rdcnt++;
- if (stream->_flag & _IOCTRLZ)
- ++rdcnt;
- } else {
- _lseeki64(fd, filepos, SEEK_SET);
- if ( (rdcnt <= _SMALL_BUFSIZ) && (stream->_flag & _IOMYBUF) &&
- !(stream->_flag & _IOSETVBUF))
- rdcnt = _SMALL_BUFSIZ;
- else
- rdcnt = stream->_bufsiz;
- if (_osfile(fd) & FCRLF)
- ++rdcnt;
- }
- } /* end if FTEXT */
- }
- filepos -= (__int64)rdcnt;
- } /* end else stream->_cnt != 0 */
- return (filepos + (__int64)offset);
+ fpos_t pos;
+ if (fgetpos (stream, &pos))
+ return -1LL;
+ else
+ return (__int64) pos;
}
-__int64 __cdecl (*__MINGW_IMP_SYMBOL(_ftelli64))(FILE *) = _ftelli64;
+__int64 __cdecl (*__MINGW_IMP_SYMBOL(_ftelli64))(FILE*) = _ftelli64;
