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Re: [v3] Fix / clean-up config vs crosses (5/n): avoid a TRY_RUN
Mark Mitchell wrote:
We need something different. The current mechanism (test -r) means that
a cross to (say) x86 GNU/Linux may yield different results than a native
build, since in the cross case the answer (whatever it is) will be
determined in some different way. That's exactly the situation we need
to avoid. To a first approximation, as long as there are IS_NATIVE
checks, we've not yet solved the cross-compilation problem.
Yes, I understand the usual issue, in general terms. Yesterday just
wanted to remove a TRY_RUN, the only RUN in the entire configury.
I would suggest either:
A1. Hard-code the answer based on the target OS (e.g., GNU/Linux has
/dev/urandom).
A2. If you like, provide a configure option to override the default.
Ok, thanks. I think that over the last days we covered quite a bit of
ground about this native vs crosses issue. Let's give the other changes
a bit of time to settle, then I will work on this improvement. By the
way, I would appreciate some feedback about
or:
B. Test at run-time, the first time you want to use the special file.
In this specific case, I think this is unfortunately a no-no, because
the layout of a class changes depending on that test and it's too late
to change it. For C++0x I'll make sure to design things differently...
Paolo.