Re: [HELP] GCC 4.1 branch Ada status on powerpc-darwin?

[Geoffrey Keating <geoffk at apple dot com>]

On 23/01/2006, at 1:51 PM, Eric Botcazou wrote:

> > As I said before in this thread, the Ada driver should do what the  
> > C++
> > driver does, which is to pass -shared-libgcc if it's going to need
> > EH support.  Or, you could pass -fexceptions to the link, which has
> > the same effect.
>
> That's not really an option, as Ada links its static runtime by  
> default and
> tries to avoid external dependencies by default.

On systems where it is present, using libgcc is no worse than using  
libSystem.

> > No, it's not possible to let people safely 'just use EH' with no
> > extra work.  The issue is compatibility with the various Mac OS X
> > versions, including future versions.  Passing -static-libgcc creates
> > an executable for which future binary compatibility is not
> > guaranteed.  Passing -shared-libgcc creates an executable which will
> > not work before 10.3.9 because the library is not there.
>
> IIUC, that passing nothing is neither equivalent to -static-libgcc  
> nor to
> -shared-libgcc is a feature, right?  I know Darwin didn't invent it  
> (IIRC
> Linux did) but that's not a valid excuse. :-)  And the "neither - 
> static-libgcc
> not -shared-libgcc" on Darwin is not compatible with the "neither
> -static-libgcc not -shared-libgcc" on Linux.

Passing nothing is equivalent to telling the compiler "I want my  
program to run on all versions since 10.1", which means you can't use  
EH at all.

> OK, I guess we have no other solution than defaulting to -static- 
> libgcc for
> Ada on Darwin.

I would rather you defaulted to -shared-libgcc, to avoid creating  
programs that don't run on future versions of Mac OS.  Do you really  
care about being able to create programs that run on 10.2?

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