[Bug tree-optimization/92860] [8/9/10/11 regression] Global flags affected by -O settings are clobbered by optimize attribute

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92860

--- Comment #28 from Martin Liška <marxin at gcc dot gnu.org> ---
> Confirmation sought that the stack backtrace I provided shows
> that the problem is a bug in the pre-processor.

No, the problem is in C parser.

> 
> If so, -E isn't going to help.

Please attach it.