Re: [PATCH v2] c++: Fix ICE with error mark for an attribute [PR124307]

[Andrew Pinski]

On Mon, Mar 16, 2026 at 12:14 PM Jason Merrill <ja...@redhat.com> wrote:
>
> On 3/16/26 9:11 AM, Marek Polacek wrote:
> > On Sun, Mar 15, 2026 at 07:48:43PM -0700, Andrew Pinski wrote:
> >> After r16-6808-g4b0e94b394fa38, we started to ICE when the
> >> std_attrs was error_mark_node. This fixes the problem by
> >> checking if it was an error_mark_node before looking for
> >> annotations.
> >>
> >> Bootstrapped and tested on x86_64-linux-gnu with no regressions.
> >>
> >> Changes since v1:
> >>   * v2: Move the check for error mark earlier.
> >>
> >>      PR c++/124307
> >>
> >> gcc/cp/ChangeLog:
> >>
> >>      * parser.cc (cp_parser_base_specifier): Check for
> >>      error mark like checking for non-nullness on the
> >>      attribute.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >>      * g++.dg/cpp0x/alignas24.C: New test.
> >>
> >> Signed-off-by: Andrew Pinski <andrew.pin...@oss.qualcomm.com>
> >> ---
> >>   gcc/cp/parser.cc                       | 3 ++-
> >>   gcc/testsuite/g++.dg/cpp0x/alignas24.C | 8 ++++++++
> >>   2 files changed, 10 insertions(+), 1 deletion(-)
> >>   create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas24.C
> >>
> >> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> >> index ffb22aa776f..a8ec3db5884 100644
> >> --- a/gcc/cp/parser.cc
> >> +++ b/gcc/cp/parser.cc
> >> @@ -31830,7 +31830,8 @@ cp_parser_base_specifier (cp_parser* parser)
> >>     tree std_attrs = cp_parser_std_attribute_spec_seq (parser);
> >>     tree annotations = NULL_TREE;
> >>
> >> -  if (std_attrs != NULL_TREE)
> >> +  if (std_attrs != NULL_TREE
> >> +      && std_attrs != error_mark_node)
> >
> > This looks like it can fit on one line.
> >
> >>       {
> >>         tree *pannotations = &annotations;
> >>         for (tree attr = std_attrs; attr; attr = TREE_CHAIN (attr))
> >> diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas24.C 
> >> b/gcc/testsuite/g++.dg/cpp0x/alignas24.C
> >> new file mode 100644
> >> index 00000000000..ef5b08213e8
> >> --- /dev/null
> >> +++ b/gcc/testsuite/g++.dg/cpp0x/alignas24.C
> >> @@ -0,0 +1,8 @@
> >> +// { dg-do compile { target c++11 } }
> >> +// { dg-options "" }
> >> +// PR c++/124307
> >
> > This should be the first line.
> >
> >> +
> >> +// we used to ICE with alignas here.
> >> +
> >> +
> >
> > And I think we can just drop the three lines above.
>
> OK with these tweaks.

Thanks, attached is what I pushed with the changes requested.

Thanks,
Andrew

>
> >> +class : alignas // { dg-error "" }
> >> --
> >> 2.43.0
> >>
> >
> > Marek
> >
>

v3-0001-c-Fix-ICE-with-error-mark-for-an-attribute-PR1243.patch
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