<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/66631>66631</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [flang] flang-new crashes with "fatal internal error: nullptr dereference"
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            flang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          k-arrows
      </td>
    </tr>
</table>

<pre>
    Here is the reproducer (from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106948#c0).
```console
$ cat test.f90
module a
  implicit none

  interface new
 pure module subroutine b(x, f)
      integer, intent(inout) :: x
 interface
        pure function f(x) result(r)
          real, intent(in) :: x
          real :: r
        end function f
      end interface
    end subroutine b
  end interface new
end module a

submodule(a) a_b
  implicit none

contains
  module procedure b
    x = int(f(real(x)) * 0.1)
  end procedure b
end submodule a_b


program test
  use a
  implicit none

 integer :: x

  x = 10
  call new(x, g)
  print *, x

contains

  pure function g(y) result(r)
    real, intent(in) :: y
    real :: r

    r = sqrt(y)
  end function g
end program test
```

Stack dump:
```console
 #0 0x0000559b23dff24d llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
 #1 0x0000559b23dff8c8 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f9cebb24520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x00007f9cebb78a7c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #4 0x00007f9cebb78a7c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #5 0x00007f9cebb78a7c pthread_kill ./nptl/pthread_kill.c:89:10
 #6 0x00007f9cebb24476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #7 0x00007f9cebb0a7f3 abort ./stdlib/abort.c:81:7
 #8 0x0000559b24abdc2a Fortran::common::getFlangRepositoryPath[abi:cxx11]()
 #9 0x0000559b244fff41 Fortran::semantics::PutLower(llvm::raw_ostream&, std::basic_string_view<char, std::char_traits<char>>) mod-file.cpp:0:0
#10 0x0000559b244fe46a Fortran::semantics::ModFileWriter::PutSymbol(llvm::raw_ostream&, Fortran::semantics::Symbol const&)
#11 0x0000559b244ffa4c Fortran::semantics::ModFileWriter::PutSubprogram(Fortran::semantics::Symbol const&)
#12 0x0000559b244fe46a Fortran::semantics::ModFileWriter::PutSymbol(llvm::raw_ostream&, Fortran::semantics::Symbol const&)
#13 0x0000559b244fdf7f Fortran::semantics::ModFileWriter::PutSymbols(Fortran::semantics::Scope const&)
#14 0x0000559b244fd030 Fortran::semantics::ModFileWriter::Write(Fortran::semantics::Symbol const&)
#15 0x0000559b244fce32 Fortran::semantics::ModFileWriter::WriteOne(Fortran::semantics::Scope const&)
#16 0x0000559b244fce02 Fortran::semantics::ModFileWriter::WriteAll(Fortran::semantics::Scope const&)
#17 0x0000559b244fcdbf Fortran::semantics::ModFileWriter::WriteAll()
#18 0x0000559b243ab6d2 Fortran::semantics::Semantics::Perform()
#19 0x0000559b23e21d7f Fortran::frontend::FrontendAction::runSemanticChecks()
#20 0x0000559b23f4c90a Fortran::frontend::CodeGenAction::beginSourceFileAction()
#21 0x0000559b23e2145d Fortran::frontend::FrontendAction::beginSourceFile(Fortran::frontend::CompilerInstance&, Fortran::frontend::FrontendInputFile const&) 
#22 0x0000559b23e18cfc Fortran::frontend::CompilerInstance::executeAction(Fortran::frontend::FrontendAction&)
#23 0x0000559b23e24702 Fortran::frontend::executeCompilerInvocation(Fortran::frontend::CompilerInstance*)
#24 0x0000559b22e1cb18 fc1_main(llvm::ArrayRef<char const*>, char const*)
#25 0x0000559b22e1bb06 main
#26 0x00007f9cebb0bd90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#27 0x00007f9cebb0be40 call_init ./csu/../csu/libc-start.c:128:20
#28 0x00007f9cebb0be40 __libc_start_main ./csu/../csu/libc-start.c:379:5
#29 0x0000559b22e1b065 _start
flang-new: error: unable to execute command: Aborted
flang-new: error: flang frontend command failed due to signal (use -v to see invocation)
flang-new version 18.0.0 (https://github.com/llvm/llvm-project.git 7afc7db7fc807a4a7ee623db491622698e8edcca)
Target: x86_64-unknown-linux-gnu
Thread model: posix
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzUWF1v67gR_TX0CxGBImV9PPjB96buLtCii80CfTQoaiSzoUmXpBKnv74gJduSknXuTZ9qOI5EDs-cORyNh-bOyU4DbND6G1o_rnjvD8Zunh-4tebVrWrTvG1-AQtYOuwPgC2crGl6ARYjWrbWHPHB-5NDbIvoDtFdJ0TS6T4xtkN0V_fdf6RSHNGdO5jXfd13iegkYjvZIPaYkrzKSkSZIIhWCSKPiGxRToa3MNoZBeMozbDgHntwPmkrMoweTdMrwHy4w1geT0oK6bE2-rLwMqU92JYLwBpex8FTbwGPGK6vrem91IBrRMszot9xi2h1WR9eAaMDG6bCpfaIllKb3iNa4SAB2-LzuODqbwqAB5dtr4WXRgcHwVOFLbheBTi7cBleFrha-PzA4cz8Mmnnk6CbqfPJXJj5gHIYnikzzszMb4qG4fmeDJ-ur4dhREseuPN9_emeCaM9l9pdDEfgkzUCmiBjfeN5xog9BkYhK4OMUbKobZSKbjFJ0om2gek7pDHaSwQXjtPPkzWd5ceYhxes3v1QCo7Zs9i3y7ohgpRc7gVXKgo75mI3IX-yUvsQVJg4_7lmV_tZ0nWIlm93ku5-ur3NDReJNpmM8bh_Wz-6myo_4XIV_r2y10owxX7yXDzjpj-eguc7FQMjyggmZ0IIWa-rmrKmbWnWYKVejgNr9-aGi9-CoBH5Dxvyn5Y3I8tf98Z5C_yIaD4Kc4sHUZYuvZSixE-y01z9wnWjQsUoh0XjsEvEKfAn8e8KREegoq0E1DXN1pSEOovoTska0d25zPd59qCk7s8Pne6HCZE4k-SIfiPnjK4pmZFjc8yi5IXA-_3JHyzwZv8sldqHnIUjaM_jpiSI7vTJK0R3U7NEILbNMsS2RX7Dz34EP1QKzdVd5KJEbJtO1Fh_hDxddheurBZw-VLcrMhx5-J-RKThEtFdEu_eXAMnF6CNk2dEd5ZLBxGbFohtJxoUc2jCi5ZhXhvrB2DfDNsXhwZ2aYj4hlBOUyjjdSMoxztjveV6SENhjkczXnfgd4rr7ncI3Lyxb79xf0Drb7yWwfR8TlO0foyZM0mFauYka9s2S-dOHBy59lJcHove_828xvS99zw43wxTNXdS7J23Unf7FwmviH0XB25nRmFg7y2X3l2m2V_Cm1ahxD-0UsH7xyM8ZmTBH7Kc3-X_d9PspIJ_WunBXkN6ejvWRn0S0z3YAQCHauOjeXXjmC415pn4Cse-HushouVXudD_A73YgmPTFu2XObrPxBLmBB_zyJY8CCM_yyNe_w_7tV5wEMDolzj8Q39K48-VyN-xIF9jsVXq6yyKJYum_um8mLCYYc-LLeN13tyP8GlRFsG2xh6XsLPyyoCmzTKVW2tCTzUWwt14t42t0Phg9fri7PsBxLNbOKHzjqbNREX4PSffTQN_BT31UUMn9ZPprYCg2Di18JMug8nWzc8Gs3C0TIYl0eNJKrC_aue5Dj3Y-7rysctf9an3wcE0k_AtFDoPJS1FK-5LtmASR-EMovc3tX5ci3lmU7ZQNiuWz9ccbXR8Y_ViBP-cxHs9tzMas4JHIRV1WuJWpPsjD_3-pNhvreVvv0M7fltfVN7G7-zveD42dbFeuKhrkuMIfzVZNGWkbiqC9_vQ1O6d59bvwzkocoqtlHD9-wZtbAE_WpQcENuuY2eZ37wu-7UaMhIPXHuppV86Gi4D-kNEjw1cSgMovXUntPwIdBbKR1F8CM6K0Lyub9jVUkmSr_GAOhi1oR18CMdFtsVgrQklEPea1wqwN3hMIhy6SB5TBG9DMwrNvfVxFF_y6rIYt1wqaHDTR-ixg0a0DOfgh5c4BoDlJFGrhRf8AtaFo0ZaJiSJZ5zFz0jSH_o6EeYY1AmpOPx7OFnzLxA-6aTHBW9F0dRFK0pS8IwXADllTZ1VaU5pXpVQQiMEv_r_g9sOfDx8DwepXj9r86onB6rBLp4lQjcKKlgPJ4D5WXPVbFhTsYqvYJPm1ZqwfJ1Wq8Ompm1NCpYLlqfAUsgzUQOFsuUpNCRLV3JDCWWkSss0pSWrElKVWdFUeUponeaMoozAkUuVhIgTY7uVdK6HTZ7nLF0pXoNy8Rc7SqOiiFK0flzZTVSo7juHMqKk8-6G4KVX8We-YcX6Ed82Q1juDuDwq_QHHEC55wpfD23XdNC9UidvcQMWWrAQqwpd9VZtfm73EN3FiMLDG4P6bwAAAP__MsckPw">