Re: [PATCH] lto: pass through -funwind-tables and -fasynchronous-unwind-tables

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Jan 18, 2023 at 12:25:11PM +0100, Andreas Schwab via Gcc-patches wrote:
> On Jan 18 2023, Richard Biener wrote:
> 
> > On Wed, Jan 18, 2023 at 11:17 AM Andreas Schwab via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >>
> >> The -funwind-tables and -fasynchronous-unwind-tables options are relevant
> >> for the output pass, thus they need to be passed through by the lto
> >> wrapper.
> >
> > They are already stored per function, and ...
> 
> Are they?  Are you sure you don't confuse that with -fexceptions?

They clearly are:
fasynchronous-unwind-tables
Common Var(flag_asynchronous_unwind_tables) Optimization
Generate unwind tables that are exact at each instruction boundary.
and
funwind-tables
Common Var(flag_unwind_tables) Optimization
Just generate unwind tables for exception handling.

The Optimization keyword is what implies that, as documented:
'PerFunction'
     This is an option that can be overridden on a per-function basis.
     'Optimization' implies 'PerFunction', but options that do not
     affect executable code generation may use this flag instead, so
     that the option is not taken into account in ways that might affect
     executable code generation.

	Jakub