Hi Pip, Helmet,

I can confirm that this is gcc 15.1 on Fedora 42.
CFLAGS are less dramatic: just `-O2 -g` 

Building with commit ac73794b43d440d34689293f4152ea38a42bb07a (which I believe has the patches) works as expected, thankyou.

Jeff Walsh



On Thu, Jun 19, 2025 at 6:19 AM Pip Cet <pipcet@protonmail.com> wrote:
"Helmut Eller" <eller.helmut@gmail.com> writes:

> On Wed, Jun 18 2025, Jeff Walsh wrote:
>
>> When building the latest of the IGC branch, commit:
>> 887db2ff38ce82bb5f33aa128c76b578caba216d 
>>
>> I am getting a SEGFAULT during temacs execution.
>>
>> running under a debugger, this occurs in root_find in igc.c
>> `if (r->d.start == start)` (r is null in this case)
>
> I can reproduce this with gcc 14.2, when configured with
>
>   ./configure -C --without-x --with-gnutls=no --with-mps=debug 'CFLAGS=-O2
>   -ggdb3 -gctf -fno-omit-frame-pointer -fno-tree-sra
>   -I/scratch/emacs/mps-install/include' 'LDFLAGS=-L
>   /scratch/emacs/mps-install/lib'
>
> I had to remove --enable-checking.

Et tu, GCC?  Let's hope this rampage of declaring what's logically a
perfectly consistent call to be UB (eventually) goes the way of C99
trigraphs...

Thanks for testing that.  I've applied your second patch and hopefully
that fixes this bug.

Jeff, could you confirm?

Thanks again!

Pip