Re: [Bug-XBoard] We distribute wrongly compiled WinBoard binaries

[h.g. muller]

At 09:48 2-2-2010 -0800, Tim Mann wrote:
> That's odd; I thought %I64 was only used by
> the Microsoft C library.
> Maybe with -mno-cygwin, gcc is linking scanf to a version from the
> Microsoft runtime library?  Just as an experiment, what happens if
> you
> do use the Cygwin library (i.e., don't give
> -mno-cygwin)?

Indeed, without the -mno-cygwin flag,
the test program I made worked fine:

address@hidden /home/fboard/xboard-4.4.1/winboard
$ cat test.c
#include <stdio.h>
main()
{
unsigned long long int t;
t = ~0;
printf("low word = %08x, high word = %08x\n", t);
printf("%llu %d %d %d\n", t, 1, 2, 3);
sscanf("23", "%llu", &t);
printf("low word = %08x, high word = %08x\n", t);
printf("%llu %d %d %d\n", t, 1, 2, 3);
}

address@hidden /home/fboard/xboard-4.4.1/winboard
$ gcc -mno-cygwin test.o -o test.exe

address@hidden /home/fboard/xboard-4.4.1/winboard
$ ./test
low word = ffffffff, high word = ffffffff
4294967295 -1 1 2
low word = 00000017, high word = ffffffff
23 -1 1 2

address@hidden /home/fboard/xboard-4.4.1/winboard
$ gcc test.o -o test.exe

address@hidden /home/fboard/xboard-4.4.1/winboard
$ ./test
low word = ffffffff, high word = ffffffff
18446744073709551615 1 2 3
low word = 00000017, high word = 00000000
23 1 2 3



> The compiler warnings probably need to
> be fixed by using the correct
> variable types.  I'm surprised they aren't bugs... however, I
> haven't
> seen the actual warnings so I don't really know what the problem is
> there.

The warnings are these:

$ make -f makefile.gcc
 ../backend.c
../backend.c: In function `HandleMachineMove':
../backend.c:7423: warning: unsigned int format, different type arg (arg
7)
../backend.c:7548: warning: unsigned int format, different type arg (arg
4)
../backend.c:7611: warning: unsigned int format, different type arg (arg
7)

In relation to Eric's explanation:

Would it not be a solution to make the definition dependent on USE_MINGW,
which we define in the makefile.gcc anyway, and which also switches the
use
of the -mno-cygwin option on? E.g. put something in the makefile
like

# set up for cygwin or not
ifeq ($(USE_MINGW),1)
CFCYG = -mno-cygwin -DUSE_I64
LFCYG = -mno-cygwin -lmsvcrt
endif

so that we could use an #ifdef USE_I64 to choose between
"%llu" and "%I64u"
in backend.h?