Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of
text editors" <bug-gnu-emacs@gnu.org> writes:

> Andy Moreton <andrewjmoreton@gmail.com> writes:
>
>> On Tue 16 Feb 2021, Andrea Corallo via "Bug reports for GNU Emacs, the Swiss army knife of text editors" wrote:
>>
>>> Andy could you point out the two libgccjit versions you used specifying
>>> wich one was used in the successfull / failed experiment?
>>
>> It seems they both now fail (and I have lost the build log from the
>> successful experiment, so I don't have a note of the commit used).
>
> That's odd.  The culprit of the bug I've isolated is a crash in
> libgccjit so should be easy to recognize (we should never crash in
> libgccjit).
>
> Anyway I've an half cooked patch to work around this issue, I guess I'll
> test it this evening.

A fix like the attached is working around the GCC bug.

The only annoyance of this approach is that libgccjit for each
compilation is outputting to console:
"libgccjit.so: note: disable pass tree-isolate-paths for functions in the range of [0, 4294967295]"

We probably also want to check at configure time and raise an error in
case configuring --with-nativecomp --with-wide-int but with a (really)
old libgccjit that does not provide
'gcc_jit_context_add_command_line_option'.

Works for me bootstraping Emacs on i686-pc-linux-gnu + GCC10 but I can't
test the Windows side, Andy would you mind giving it a try?

Thanks

  Andrea