[Bug c++/126794] [reflection] ICE in splice of member access via an incomplete base class

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126794

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 65300
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65300&action=edit
testcase

Please next time attach the testcase too rather than just linking to godbolt.


The ICE:
<source>: In instantiation of 'int get(W*) [with W = E<2>]':
<source>:11:26:   required from here
   11 | int main() { return ::get((E<2> *)0); }
      |                     ~~~~~^~~~~~~~~~~
<source>:8:23: internal compiler error: Segmentation fault
    8 |     return o->[:^^A::m:];
      |            ~~~~~~~~~~~^~
0x2bac168 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
        ???:0
0x2ba0dab internal_error(char const*, ...)
        ???:0
0xe4d53c finish_non_static_data_member(tree_node*, tree_node*, tree_node*, int)
        ???:0
0xdfd23d instantiate_decl(tree_node*, bool, bool)
        ???:0
0xe0712a instantiate_pending_templates(int)
        ???:0
0xc68bf8 c_parse_final_cleanups()
        ???:0
0xf2b5b8 c_common_parse_file()
        ???:0
/cefs/50/504f1145e895d4966b9be341_gcc-trunk-20260811/bin/../libexec/gcc/x86_64-linux-gnu/17.0.0/cc1plus
-quiet -imultiarch x86_64-linux-gnu -iprefix
/cefs/50/504f1145e895d4966b9be341_gcc-trunk-20260811/bin/../lib/gcc/x86_64-linux-gnu/17.0.0/
-D_GNU_SOURCE <source> -quiet -dumpdir /app/ -dumpbase output.cpp -dumpbase-ext
.cpp -masm=intel -mtune=generic -march=x86-64 -g -std=c++26
-fdiagnostics-color=always -fno-verbose-asm -freflection -o /app/output.s
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1