Of course I use 'offsetof' in the first part of the tool pipeline. The
problem is, though getting the result of it out of the cross-gcc. Here
we cannot simply say
> printf("offsXYZ = %zu", offsetof(XY, Z));
because there is no way to run the cross-gcc output. Instead I do:
> char offsXYZ[offsetof(XY, Z)];
and the inspect the resulting object file with 'nm'. In the second
(i.e. host) gcc
invocation I am not allowed to use 'offsetof' to obtain target values,
so I include
the transformed 'nm' output of the form
> #define offsXYZ 0x12
and compile mkDerivedConstants.c with these constants.
Hope this clears it up.
Cheers,
Gabor
On 11/5/12, Erik de Castro Lopo <mle...@mega-nerd.com> wrote:
> Gabor Greif wrote:
>
>> +1. A configure script will run (almost) till the heat death of the
>> universe.
>>
>> I have a solution on the cross-compiler-alienless branch which does
>> exactly
>> what you propose: feed the relevant headers into the cross-gcc, obtain
>> the offsets/sizes back
>> by 'nm', and massage stuff to obtain all as macros then feed those
>> into mkDerivedConstants.c.
>
> Doesn't the offsetof macro do the right thing for get the offset of
> fields within a struct?
>
> http://en.wikipedia.org/wiki/Offsetof
>
> Erik
> --
> ----------------------------------------------------------------------
> Erik de Castro Lopo
> http://www.mega-nerd.com/
>
> _______________________________________________
> Cvs-ghc mailing list
> Cvs-ghc@haskell.org
> http://www.haskell.org/mailman/listinfo/cvs-ghc
>
_______________________________________________
Cvs-ghc mailing list
Cvs-ghc@haskell.org
http://www.haskell.org/mailman/listinfo/cvs-ghc
