Re: gnat cross-compiles ?

[Andreas Schwab <schwab at suse dot de>]

Joe Buck <Joe.Buck@synopsys.com> writes:

|> Marc Espie <espie@nerim.net> writes:
|> > 
|> > |> I'd like to know which processors are happy with gnat in 3.1 (or the 3.1
|> > |> branch), and whether cross-compiles have a chance to work, before I embark
|> > |> on a wild goose chase...
|> 
|> Andreas Schwab writes:
|> > We have already built gnat for ia64, alpha and ppc, via cross compiling
|> > from i386.  Sparc, s390 and x86-64 are on my todo list.
|> 
|> I think that cross-compiling is the most confusing part of GCC, we
|> certainly get more questions about that than anything else, even from
|> experts.  Andreas, would you be willing to write a note describing your
|> process?  It doesn't need to be thorough, it could be as simple as just
|> listing the exact sequence of commands you used to produce, say, the ppc
|> compiler by cross-compilation from i386.

I think the worst that can go wrong is that you *must* create ${libsubdir}
beforehand, otherwise the cross compiler does not find the target headers
(since all search paths are relative to ${libsubdir}).  Further, if you
don't use a unified binutils+gcc tree, you should create links
${builddir}/gcc/{nm,objdump} pointing to the respective target programs
before running configure, so that it can figure out the right
capabilities.  Everything else should be straight forward.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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