On Tue, May 03, 2022 at 04:43:05PM -0400, Jason Merrill via Gcc-patches wrote:
> On 5/2/22 12:18, Marek Polacek wrote:
> > Consider
> >
> > struct F {
> > F(int) {}
> > F operator()(int) const { return *this; }
> > };
> >
> > and
> >
> > F(i)(0)(0);
> >
> > where we're supposed to first call the constructor and then invoke
> > the operator() twice. However, we parse this as an init-declarator:
> > "(i)" looks like a perfectly valid declarator, then we see an '(' and
> > think it must be an initializer, so we commit and we're toast.
>
> How vexing!
:-) Most vexing indeed!
> > My
> > fix is to look a little bit farther before deciding we've seen an
> > initializer.
> >
> > This is only a half of c++/64679, the other part of the PR is unrelated:
> > there the problem is that we are calling pushdecl while parsing
> > tentatively (in cp_parser_parameter_declaration_list), which is bad.
> > I don't know how to fix it though, maybe move the pushdecl call to
> > grokparms? Tricky :(.
>
> Can we pop the parm decls when the tentative parse fails?
Unfortunately no, we'll have already given a hard error when that
happens. About to send a patch where I describe the problem in
detail.
> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> OK.
Thanks!
Marek
