[PATCH] tree: Fix -fcompare-debug issues due to protected_set_expr_location [PR94323]

[Richard Biener]

On Fri, 27 Mar 2020, Jakub Jelinek wrote:

> On Thu, Mar 26, 2020 at 08:41:41PM -0300, Alexandre Oliva wrote:
> > On Mar 26, 2020, Jakub Jelinek <jakub@redhat.com> wrote:
> > 
> > > Or disable -gstatement-frontiers by default and declare it -fcompare-debug
> > > incompatible.
> > 
> > I don't get what makes debug stmts introduced by -gstatement-frontiers
> > special in this regard.  I recall working a lot on making statement list
> > management compatible with debug stmts for -fcompare-debug purposes back
> > when introducing them, but not breaking new ground when extending them
> > with markers rather than binds.
> 
> The hardest issue I gave up completely on after trying 3 different
> approaches is PR93786, I just don't know what to do in that case.
> Gimplification of a STATEMENT_LIST is destructive, especially the
> voidify_wrapper_expr part of it, and if the STATEMENT_LIST is used multiple
> times, that is a severe problem.

The question for this case is wheter we can arrange for the STATEMENT_LIST
to be present even for -g0 and "solve" the issue that way?

> The PR94323 and PR94272 changes worked, but they are quite unclean and in
> bugzilla there is at least one another -fcompare-debug issue that goes away
> with -gno-statement-frontiers (PR94340).
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
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