Re: [Mingw-cross-env-list] Re: GCC 4.5 (was URL problems)

[Tony Theodore]

On 1 May 2010 01:16, Mark Brand <address@hidden> wrote:
>
>> I did a quick diff of the qt logs, and there seems to be three
>> differences:
>>
>> 1) In some places GCC4.4.0 uses -fexceptions -mthreads -frtti
>>                    where GCC4.5 uses -fno-exceptions -fno-rtti
>> (without -mthreads)
>
> Great idea. It inspired me to do the same experiment.  I don't see the
> difference you describe in 1). That's a bit puzzling. Could this be because
> we are working on different platforms? I am using 64-bit opensuse Linux.
>  The detection of rtti support is added to the Qt configure script by a
> mingw-cross-env patch. I'm curious about what the rtti detection does on
> your system with gcc 4.4 and 4.5. Here the test is positive as expected in
> both cases. For gcc 4.5:
>
> rtti auto-detection... ()
[...]
> rtti enabled.

I just checked through the logs again, I get the same "rtti enabled"
after the autodetection for both compilers, it's only the initial
options passed that differ. Those differences only occur during the
configue stage, after that, the same options are passed in the main
compilation stages.

I'm not sure what causes this, I'm doing most of this in OSX 10.6 and
it's not always clear if it's in 32 or 64 bit mode. It could also be
that I was trying different configure options and changing the default
system compiler. I'll try it again after a make clean and use the
patches I sent.

Mostly though, the differences are small, I was looking for something
that jumped out. Even though those options aren't used by default, the
4.5 seems to support them if needed.

Regards,

Tony