Re: Warn on naked cross-tool names, add macros to detect target tools

[Kevin Ryde]

"Paolo Bonzini" <address@hidden> writes:
>
> What guarantees that the host cc will be passed the correct
> options to generate i686 code?

Nothing, unless the package makes special arrangements to select good
default cflags.  But the cflags is not the only thing i686 can select,
various bits of assembler code is a good example.

> Also, what about compiling on build=i686 for host=i386?  Then compiling a
> simple test program will work, but a more complex one may case problems like
> using new instructions (cmov) or sse math.

I think you mean the other way around, build=i386 host=i686.  But yes,
the host code wouldn't run on the build system.  Autoconf is already
careful not to try to run code in such cases.

> I don't know how much this is widespread, so if the patch is accepted the
> deprecation period, during which people can complain, will help.

Cross compiling is no doubt not common, and a black art at the best of
times, so anyone doing it has to be assumed to be smart enough to know
they need cross tools.  I just don't see that there's anything gained
by forcing those tools into prefixed names.  I believe it's always
worked in the past just to have one's PATH setup with suitable cross
tools and I think that can usefully remain, for compatibility if for
no other reason.