Re: -mmacosx-version-min and libgcc

[Geoffrey Keating <geoffk at apple dot com>]

On 29/09/2005, at 10:49 PM, Ian Lance Taylor wrote:

> Geoffrey Keating <geoffk@apple.com> writes:
>
>
> > > For this particular case you just have to define STRIP_FOR_TARGET in
> > > the gcc Makefile.  It doesn't have to have precisely the same  
> > > value as
> > > it does at top-level; it just has to work well enough for  
> > > developers,
> > > not for users.
> >
> > The problem with this is that there's no equivalent of
> > TARGET_FLAGS_TO_PASS.  Exporting to sub-makes is done via environment
> > variables, so if you explicitly set anything in the makefile that is
> > the setting that wins in a sub-make (for instance, in a stage of a
> > bootstrap).
>
> I'm not sure I understand.  AR_FOR_TARGET, for example, is in
> BASE_FLAGS_TO_PASS in the top level Makefile.  So it will be
> explicitly passed to the gcc Makefile, and will override any setting
> in the gcc Makefile.
>
> If your concern is that there is no TARGET_FLAGS_TO_PASS in the gcc
> Makefile, I don't see how that matters.  Either it will get the
> setting from the top level, as passed explicitly or via MAKEFLAGS, or
> it will be using the same setting anyhow since it is using the same
> Makefile.
>
> There is a potential problem is gcc calls another Makefile recursively
> and that other Makefile needs to use AR_FOR_TARGET, but as far as I
> know that never happens.
>
> Can you give a clearer example of what won't work?

For instance

make bootstrap
rm gcc/libgcc.a
make quickstrap AR_FOR_TARGET=/ar/that/doesnt/exist

should fail when it tries to build libgcc.a, but it doesn't.  The top- 
level make correctly passes down the overridden AR_FOR_TARGET, but  
quickstrap does '$(MAKE) $(REMAKEFLAGS) $$LAST' and $(REMAKEFLAGS) is  
just

REMAKEFLAGS=LANGUAGES="$(LANGUAGES)" BOOT_CFLAGS="$(BOOT_CFLAGS)"

and doesn't pass down AR_FOR_TARGET.

The settings are not passed via MAKEFLAGS.  They might be passed by  
MAKEOVERRIDES, except that the GCC makefile says

# And this tells it not to automatically pass command-line variables
# to recursive makes.
MAKEOVERRIDES =

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