Hi John,
> Running in a native configure in msys2/mingw64 and make builds ok;
>
>
> The following modules are added to libnu.a:
> freading.o stat-time.o unistd.o fflush.o fpurge.o fseek.o fseeko.o
> fstat.o lseek.o msvc-inval.o msvc-nothrow.o stat-w32.o
>
> Running the app:
>
> ./bigtest.exe
> test big file
> creating big file ...done
> sizeof(off_t)=8
> seek status=-1
> tell pos=0
>
> Running in debug, and doing a break on _lseek
>
> (gdb) bt
> #0 0x00007ffd2f7ad1cb in msvcrt!_lseek () from
> C:\WINDOWS\System32\msvcrt.dll
> #1 0x00000000004016e7 in rpl_lseek (fd=3, offset=offset@entry=0,
> whence=whence@entry=1) at lseek.c:69
> #2 0x0000000000401636 in rpl_fseeko (
> fp=fp@entry=0x7ffd2f81fa90 <msvcrt!_iob+144>, offset=offset@entry=0,
> whence=whence@entry=2) at fseeko.c:45
> #3 0x000000000040838c in main () at main.cpp:41
>
> And for the lseek call that fails:
>
> (gdb) bt
> #0 0x00007ffd2f7ad1cb in msvcrt!_lseek () from
> C:\WINDOWS\System32\msvcrt.dll
> #1 0x00000000004016e7 in rpl_lseek (fd=3, offset=offset@entry=0,
> whence=whence@entry=2) at lseek.c:69
> #2 0x0000000000401683 in rpl_fseeko (
> fp=fp@entry=0x7ffd2f81fa90 <msvcrt!_iob+144>, offset=offset@entry=0,
> whence=whence@entry=2) at fseeko.c:117
> #3 0x000000000040838c in main () at main.cpp:41
>From these backtraces I infer that:
- gnulib's _GL_WINDOWS_64_BIT_OFF_T is not defined, because mingw64 defines
off_t to a 64-bit type already, due to _FILE_OFFSET_BITS=64, which is
ensured by AC_SYS_LARGEFILE.
- mingw does a '#define lseek _lseeki64' in this situation (for proper
large file support).
- The 'undef lseek' in gnulib's unistd.h and lseek.c undoes it.
The patch below should fix it. I've pushed it already, but I would appreciate
your feedback.
> It is entering the lseek call which is really _lseek (parameters that
> are long) rather than 64bit instead of using the _lseeki64 call.
>
> #if _GL_WINDOWS_64_BIT_OFF_T
> return _lseeki64 (fd, offset, whence);
> #else
> return lseek (fd, offset, whence);
> #endif
>
>
> Looking for _GL_WINDOWS_64_BIT_OFF_T, it only gets set in
> lib/sys_types.in.h if WINDOWS_64_BIT_OFF_T is set.
>
> Should lseek.c call _lseeki64 regardless of _GL_WINDOWS_64_BIT_OFF_T
> value ...
Yup. You hit the nail on the head.
2020-01-25 Bruno Haible <br...@clisp.org>
lseek: Fix the override to not undo the effects of AC_SYS_LARGEFILE.
Reported by John Donoghue <john.david.donog...@gmail.com> in
<https://lists.gnu.org/archive/html/bug-gnulib/2020-01/msg00146.html>.
* lib/lseek.c (rpl_lseek): When AC_SYS_LARGEFILE has enabled a 64-bit
off_t on mingw, invoke _lseeki64 instead of lseek.
diff --git a/lib/lseek.c b/lib/lseek.c
index 013f665..b249839 100644
--- a/lib/lseek.c
+++ b/lib/lseek.c
@@ -63,7 +63,7 @@ rpl_lseek (int fd, off_t offset, int whence)
return -1;
}
#endif
-#if _GL_WINDOWS_64_BIT_OFF_T
+#if _GL_WINDOWS_64_BIT_OFF_T || (defined __MINGW32__ && defined
_FILE_OFFSET_BITS && (_FILE_OFFSET_BITS == 64))
return _lseeki64 (fd, offset, whence);
#else
return lseek (fd, offset, whence);
