[Bug c++/92531] New: [9/10 Regression] ICE in uses_template_parms, at cp/pt.c:10471

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92531

            Bug ID: 92531
           Summary: [9/10 Regression] ICE in uses_template_parms, at
                    cp/pt.c:10471
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

g++-10.0.0-alpha20191110 snapshot (r278028) and g++ 9.2 ICE when compiling the
following testcase w/ -std=c++17:

template <typename XK>
struct zq {
  void ky () noexcept ([]{});
};

% g++-10.0.0-alpha20191110 -std=c++17 -c as6atodv.cc
as6atodv.cc:4:2: internal compiler error: in uses_template_parms, at
cp/pt.c:10471
    4 | };
      |  ^
0x6302cc uses_template_parms(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/pt.c:10471
0x995c9b canonical_eh_spec(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/tree.c:2577
0x995ec2 build_cp_fntype_variant(tree_node*, cp_ref_qualifier, tree_node*,
bool)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/tree.c:2622
0x8ee22d cp_parser_class_specifier_1
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:23908
0x8ef662 cp_parser_class_specifier
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:23965
0x8ef662 cp_parser_type_specifier
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:17566
0x8f0516 cp_parser_decl_specifier_seq
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:14239
0x9138ad cp_parser_single_declaration
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:28986
0x913c5b cp_parser_template_declaration_after_parameters
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:28649
0x914363 cp_parser_explicit_template_declaration
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:28915
0x9174c3 cp_parser_declaration
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:13271
0x9179ad cp_parser_translation_unit
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:4721
0x9179ad c_parse_file()
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/cp/parser.c:42900
0xa1a0d9 c_common_parse_file()
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191110/work/gcc-10-20191110/gcc/c-family/c-opts.c:1183

As a side note, clang 9.0.0 and icc 19.0.1 accept the testcase w/ the first
line removed, while g++ rejects it:

--- /home/asolokha/t1/as6atodv.cc
+++ #<buffer as6atodv.cc>
@@ -1,4 +1,3 @@
-template <typename XK>
 struct zq {
   void ky () noexcept ([]{});
 };