Re: [RFC][PATCH 3/N] lto-plugin: Port to C++

[Richard Biener <richard.guenther@gmail.com>]

On Wed, Jan 5, 2022 at 2:28 PM Martin Liška <mliska@suse.cz> wrote:
>
> Hello.
>
> I'm working on some changes that will be needed for support of ld.mold.
> And I would like to have the plugin in C++. Having that, we can utilize basic
> contains like std::vector (instead of xrealloc(foo, len + 1)...).
>
> I split the patch into 2 pieces where the second one is only result
> of autoreconf and automake.
>
> Lightly tested with ld.bfd, ld.gold and lto.exp.

With the linker plugin build by GCC using its libstdc++ statically(?)
and for example gold (also a C++ application) built by another
(GCC) system compiler there might be two different versioned
libstdc++ in the process image after dlopening the plugin.  Is the
libstdc++ "copy" in the plugin sufficiently isolated to not cause
problems here?  Do we need to pay extra care as to the subset
of the C++ standard library we can use (I'm thinking of parts
initialized on load time like I/O)?

That said, I'm not sure this is worth the trouble.

Richard.

>
> Thoughts?
> Thanks,
> Martin