On Wed, Jan 15, 2025 at 04:18:36PM -0500, Jason Merrill wrote:
> On 1/15/25 12:55 PM, Marek Polacek wrote:
> > On Wed, Jan 15, 2025 at 09:39:41AM -0500, Jason Merrill wrote:
> > > On 11/15/24 9:08 AM, Marek Polacek wrote:
> > > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> > > >
> > > > -- >8 --
> > > > The error here should also check that we aren't nested in another
> > > > lambda; in it, at_function_scope_p() will be false.
> > > >
> > > > PR c++/117602
> > > >
> > > > gcc/cp/ChangeLog:
> > > >
> > > > * parser.cc (cp_parser_lambda_introducer): Check if we're in a
> > > > lambda
> > > > before emitting the error about a non-local lambda with
> > > > a capture-default.
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > > * g++.dg/cpp2a/lambda-uneval19.C: New test.
> > > > ---
> > > > gcc/cp/parser.cc | 5 ++++-
> > > > gcc/testsuite/g++.dg/cpp2a/lambda-uneval19.C | 14 ++++++++++++++
> > > > 2 files changed, 18 insertions(+), 1 deletion(-)
> > > > create mode 100644 gcc/testsuite/g++.dg/cpp2a/lambda-uneval19.C
> > > >
> > > > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> > > > index 07b12224615..dc79ff42a3b 100644
> > > > --- a/gcc/cp/parser.cc
> > > > +++ b/gcc/cp/parser.cc
> > > > @@ -11611,7 +11611,10 @@ cp_parser_lambda_introducer (cp_parser*
> > > > parser, tree lambda_expr)
> > > > cp_lexer_consume_token (parser->lexer);
> > > > first = false;
> > > > - if (!(at_function_scope_p () || parsing_nsdmi ()))
> > > > + if (!(at_function_scope_p ()
> > > > + || parsing_nsdmi ()
> > > > + || (current_class_type
> > > > + && LAMBDA_TYPE_P (current_class_type))))
> > >
> > > How about using current_nonlambda_scope () instead of at_function_scope_p
> > > ()?
> >
> > I think I remember not using that because current_nonlambda_scope() will
> > give us a namespace_decl :: for non-local stuff so it won't be null. Do
> > you still prefer that (checking the result of current_nonlambda_scope())
> > to what I did in my patch?
>
> I think so, your change looks to be true for lambdas outside function scope
> as well.
I think it works correctly for both
auto x = [&]() { // error
[&]() { };
};
auto x2 = []() {
[&]() { };
};
but current_nonlambda_scope () will return '::' for the nested lambdas too.
Am I missing something?
Marek
