[GRASS-dev] diglib test.c fails on 64bit win

Markus Metz markus.metz.giswork at googlemail.com
Fri May 14 15:02:42 EDT 2010

On Fri, May 14, 2010 at 8:39 PM, Glynn Clements
<glynn at gclements.plus.com> wrote:
> Helmut Kudrnovsky wrote:
>> >In summary, it seems that grass libraries have no access to a 64-bit
>> >off_t when compiled in MINGW32, also with ./configure
>> >--enable-largefile.
>> maybe FYI:
>> "GCC for both x64 & x86 Windows:
> This is unrelated to Win64.
> Win32 has a 64-bit version of off_t and functions which use it.
> However, there isn't any equivalent of _FILE_OFFSET_BITS=64, which (on
> Unix) causes off_t and any relevant functions to be "redirected" to
> the 64-bit equivalents.
> The problem with using 64-bit offsets is that they have to be used
> consistently. If code using a 64-bit off_t passes it to code expecting
> a 32-bit off_t, you lose.

All this refers to grass7 because only grass7 has different diglib
tests for 32-bit off_t and 64-bit off_t. Sometime last year I
successfully compiled grass7 with MINGW64, but without GUI because at
that time
was not yet available. So I had to compile wxpython for MINGW64 from
source. Problem was that wxpython insisted on sizeof(long) ==
sizeof(void *), and on Windows 64-bit, sizeof(long) == 4 and
sizeof(void *) == 8.  I spent a lot of time hacking wxpython but
eventually gave up. I don't know if grass7 will compile using the new
wxpython-devel package since it was apparently compiled with MSVC 9.
Testing welcome. I recommend a lot of patience and a lot of coffee
while waiting;-)

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