Re: [Libunwind-devel] [PATCH 5/7] build: make libunwind-coredump build optional

[Cody P Schafer]

On 09/05/2012 01:48 AM, Tommi Rantala wrote:
> 2012/9/4 Cody P Schafer <address@hidden>:
> > Disable the building of libunwind-coredump except on x86_64 and x86
> > (where implimentations exsist).
>
> Technically checking just the architecture would not be enough, since
> there are also some OS specific bits and pieces.
>
> We could also provide no-op implementations for the missing
> architectures, similar to (as far as I can tell) the setjmp library.
> This might make distro people happier, as they could package the
> coredump library for all architectures unconditionally.

The one issue with doing this is that for applications which are users 
of libunwind, we exchange a build error (which is preferable) for a 
runtime error.

> > +no_force_coredump=true
> > +AC_ARG_ENABLE(coredump,
> > +             AS_HELP_STRING([--enable-coredump],[build libunwind-coredump 
> > library]),
> > +             [no_force_coredump=false; use_coredump=true],
> > +             [no_force_coredump=false; use_coredump=false])
> > +
> > +if $no_force_coredump; then
> > +  case "$host_arch" in
> > +    x86|x86_64) use_coredump=true ;;
> > +    *) use_coredump=false;;
> > +  esac
> > +fi
>
> BTW, after applying this patch, the coredump library is no longer
> built by default on my x86_64 machine. I believe that AC_ARG_ENABLE()
> is not used entirely correctly here.

You're correct.
The 'signature' of AC_ARG_ENABLE is
"AC_ARG_ENABLE(option-name, help-string, action-if-present, 
action-if-not-present)"

I mistook action-if-not-present for action-if-disabled.

I'll fix this. Somehow.