[Bug c++/106009] New: [modules] internal compiler error: in mark_by_value, at cp/module.cc:4775

["overlord624 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106009

            Bug ID: 106009
           Summary: [modules] internal compiler error: in mark_by_value,
                    at cp/module.cc:4775
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: overlord624 at gmail dot com
  Target Milestone: ---

Created attachment 53158
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53158&action=edit
output with -freport-bug

Trying to compile the spdlog library to a header unit causes an internal
compiler error. Adding -save-temps to the parameters causes the same error, but
the compiler claims the error is non-reproducible. No errors occur when the
same header is included in the global module fragment of a regular module.

$ g++-exp -freport-bug -fmodules-ts -std=c++20 -Wall -Wextra -pedantic
-DSPDLOG_COMPILED_LIB -x c++-system-header spdlog/spdlog.h
/usr/include/spdlog/spdlog.h: internal compiler error: in mark_by_value, at
cp/module.cc:4775
0x7112a2 trees_out::mark_by_value(tree_node*)
        /media/extra/sources/gcc/gcc/cp/module.cc:4775
0xabe961 trees_out::mark_declaration(tree_node*, bool)
        /media/extra/sources/gcc/gcc/cp/module.cc:12245
0xabebd9 trees_out::mark_class_def(tree_node*)
        /media/extra/sources/gcc/gcc/cp/module.cc:11744
0xac859d depset::hash::find_dependencies(module_state*)
        /media/extra/sources/gcc/gcc/cp/module.cc:13126
0xac8cc0 module_state::write_begin(elf_out*, cpp_reader*, module_state_config&,
unsigned int&)
        /media/extra/sources/gcc/gcc/cp/module.cc:17640
0xac9f84 finish_module_processing(cpp_reader*)
        /media/extra/sources/gcc/gcc/cp/module.cc:19962
0xa58c85 c_parse_final_cleanups()
        /media/extra/sources/gcc/gcc/cp/decl2.cc:5156
0xc7ab60 c_common_parse_file()
        /media/extra/sources/gcc/gcc/c-family/c-opts.cc:1253
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Preprocessed source stored into /tmp/cc4TWK1u.out file, please attach this to
your bugreport.

$ g++-exp -v
Using built-in specs.
COLLECT_GCC=g++-exp
COLLECT_LTO_WRAPPER=/media/extra/libexec/gcc/x86_64-pc-linux-gnu/13.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /media/extra/sources/gcc/configure --host=x86_64-pc-linux-gnu
--prefix=/media/extra --disable-multilib --enable-threads --enable-tls
--enable-languages=c,c++ --disable-nls
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.0.0 20220616 (experimental) (GCC)