[llvm-dev] unable to compile llvm with gcc 4.7.4

[Sylvain Bertrand via llvm-dev]

Hi,

The problem is modern c++. I can have a reasonable system boostrape-ed
with (tinycc/alternative C compiler), but only in the gcc world since
a modern c++ compiler is only bootsrape-able from near any C compiler
there. clang and llvm are unable to do it. That why I would need to
get 2 gccs: "any C compiler" -> gcc 4.7.4 -> gcc recent_version ->
llvm.

On Fri, Oct 14, 2016 at 4:02 PM, Renato Golin <renato.golin at linaro.org> wrote:
> On 13 October 2016 at 12:56,  <sylvain.bertrand at gmail.com> wrote:
>> It's my custom distro. My goal is to make it boostrap-able with tinycc (or any
>> little C compiler alternative) as a one-man reasonable job. With the removal of
>> gcc 4.7 support now official, I would need to have a 3 step bootstrap, adding a
>> modern gcc (which is guaranted to compile with iso c++98-ish gcc 4.7.4, feature
>> that clang cannot guaranted anymore).
>
> Hi Sylvain,
>
> I have to say, after a while thinking about your use case, I cannot
> come up with a better solution than a 3-stage build. :(
>
> Maybe you need to step back a bit and ask yourself: what would be the
> system changes to adopt GCC 4.8 natively instead of tinycc.
>
> What distributions do is to compile the base GCC they'll use first,
> making sure all the correct libraries in all the correct versions are
> bundles in the right places, then use that toolchain for *everything*.
>
> You seem comfortable enough building GCC 4.7, I assume as a side
> package, like BSD ports. I'm also assuming you already need GCC (for
> packages other than LLVM), then why not make GCC your system compiler?
>
> The dependencies will already be there anyway, and I don't think GCC
> 4.8's libraries are much bigger than 4.7, so it does seem like an
> overall gain.
>
> Of course, it'll mean you'll have to test your packages with GCC 4.8,
> but assuming they already use tinycc or GCC 4.7, I hope you'll have
> very little additional problems.
>
> Would any of that help?
>
> cheers,
> --renato