[Bug analyzer/107948] GCC Static Analyzer doesn't realize `0 - width <= 0` is always true when `width > 0` and `width is int` type，

[geoffreydgr at icloud dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107948

--- Comment #3 from Geoffrey <geoffreydgr at icloud dot com> ---
(In reply to CVS Commits from comment #1)
> The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>:
> 
> https://gcc.gnu.org/g:0b737090a69624dea5318c380620283f0321a92e
> 
> commit r13-4456-g0b737090a69624dea5318c380620283f0321a92e
> Author: David Malcolm <dmalc...@redhat.com>
> Date:   Thu Dec 1 21:28:55 2022 -0500
> 
>     analyzer: handle comparisons against negated symbolic values [PR107948]
>     
>     gcc/analyzer/ChangeLog:
>             PR analyzer/107948
>             * region-model-manager.cc
>             (region_model_manager::maybe_fold_binop): Fold (0 - VAL) to -VAL.
>             * region-model.cc (region_model::eval_condition): Handle e.g.
>             "-X <= 0" as equivalent to X >= 0".
>     
>     gcc/testsuite/ChangeLog:
>             PR analyzer/107948
>             * gcc.dg/analyzer/feasibility-pr107948.c: New test.
>     
>     Signed-off-by: David Malcolm <dmalc...@redhat.com>

Thanks for your effort!