[Bug c++/109946] New: linker error undefined reference to `vtable for std::bad_expected_access<void>'

[Bug c++/109946] New: linker error undefined reference to `vtable for std::bad_expected_access<void>'

[saifi.khan at nishan dot io]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109946

            Bug ID: 109946
           Summary: linker error undefined reference to `vtable for
                    std::bad_expected_access<void>'
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: saifi.khan at nishan dot io
  Target Milestone: ---

Environment: Archlinux kernel 6.3.2 glibc 2.37 gcc 13.1 gcc 14.0.0

Consider the following code

import "iostream";
import "string";
import "string_view";
import "expected";
import "charconv";
import "system_error";

namespace parser {

enum class error {
      input_invalid
      , overflow
};

auto logic (std::string_view str) -> std::expected <double, error> {
      int value {0};

      std::from_chars_result result { std::from_chars (str.begin (), str.end
(), value) };

      if (result.ec == std::errc{}) {
            return value;
      }
      else if (result.ec == std::errc::invalid_argument) {
            return std::unexpected {error::input_invalid};
      }
      else if (result.ec == std::errc::result_out_of_range) {
            return std::unexpected {error::overflow};
      }
}

}

auto test () -> void {
      std::string str { "9876dairy" };

      const auto result { parser::logic (str) };

      if (result.has_value ()) {
            std::cout << result.value ()
                      << '\n';
      }
      else if (result.error () == parser::error::input_invalid) {
            std::cout << "E: input invalid"
                      << '\n';
      }
      else if (result.error () == parser::error::overflow) {
            std::cout << "overflow"
                      << '\n';
      }
      else {
            std::cout << "unexpected"
                      << '\n';
      }
}

The code compiles and program work fine with

- gcc 13.1.1
- gcc 14.0.0

as long as i don't use the option -fmodules-ts.

When using the -fmodules-ts flag, the following linker error is seen:

/usr/bin/ld: /tmp/cchUGnbx.o: warning: relocation against
`_ZTVSt19bad_expected_accessIvE' in read-only section
`.text._ZNSt19bad_expected_accessIvED2Ev[_ZNSt19bad_expected_accessIvED5Ev]'
/usr/bin/ld: /tmp/cchUGnbx.o: in function
`std::bad_expected_access<void>::bad_expected_access()':
/opt/gcc/include/c++/14.0.0/expected:80: undefined reference to `vtable for
std::bad_expected_access<void>'
/usr/bin/ld: /tmp/cchUGnbx.o: in function
`std::bad_expected_access<void>::~bad_expected_access()':
/opt/gcc/include/c++/14.0.0/expected:85: undefined reference to `vtable for
std::bad_expected_access<void>'
/usr/bin/ld:
/tmp/cchUGnbx.o:(.data.rel.ro._ZTISt19bad_expected_accessIN6parser5errorEE[_ZTISt19bad_expected_accessIN6parser5errorEE]+0x10):
undefined reference to `typeinfo for std::bad_expected_access<void>'
/usr/bin/ld: warning: creating DT_TEXTREL in a PIE
collect2: error: ld returned 1 exit status

[Bug c++/109946] [c++modules] linker error undefined reference to `vtable for std::bad_expected_access<void>'

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109946

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |14.0
                 CC|                            |ppalka at gcc dot gnu.org
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> ---
This seems to work with recent GCC trunk.