<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/143740>143740</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [flang] ASSERTION when module and the main program are in two different files.
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          DanielCChen
      </td>
    </tr>
</table>

<pre>
    File mod.f
```
module m
type::base
integer(4)::id
contains
procedure::print=>printbase
end type
private::printbase
interface
subroutine printbase(b)
import::base
class(base),intent(in)::b
end
end interface
end
```

File main.f
```
module m1
use m
    type, extends (base) :: child
        character*20 :: name = ''

        contains

 procedure :: print => printChild
    end type

    contains

 subroutine printChild (b)
        class (child), intent(in) :: b

 print *, b%id, b%name
    end subroutine
end module

program ftpbnd509a1
use m1
    type (base), target :: b1
    type (child), target :: c1

    class (base), pointer :: b_ptr


    c1 = child (20, 'c1_test')

end
```

Flang asserts as:
```
Assertion failed: isa<To>(Val) && "cast<Ty>() argument of incompatible type!", file llvm-project/llvm/include/llvm/Support/Casting.h, line 572, decltype(auto) llvm::cast(From &) [To = fir::RecordType, From = mlir::Type]()
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /home/cdchen/FLANG/build/bin/flang -fc1 -triple powerpc64-ibm-aix7.2.0.0 -emit-obj -ffree-form -fcolor-diagnostics -mrelocation-model pic -pic-level 2 -target-cpu pwr7 -resource-dir /home/cdchen/FLANG/build/lib/clang/21 -mframe-pointer=all -o ftpbnd509a1.o -x f95 ftpbnd509a1.f
flang-21: error: unable to execute command: IOT/Abort trap
```

If I move the code in mod.f into main.f, it compiles successfully.
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJycVsuO2zoS_Rp6U5BAUZZlL7xQ7NaggSAJ0o3ZBhRZsplQpEBS_fj7ASn50T33AhfX8EJmPXjq1KmyuPfqZBD3pPpCquOKT-Fs3f7IjUJ9OJzRrDor3_et0giDlXlPaEM2dPnSZrByiiZCm_A-IikbUjYd90hoo0zAEzrCtmvCdrNJSUIbYU3gynhCm9FZgXJyS-TolAmkPJLyIT0umdBISOljgHrh4d797jbXcxGf_dQ5OwVlEG4ubNtFGLRRw2hd-ABVaO599EiOO8IOMZ0JhG2VuYLvZigLoPsL59N7YghtZtK4Mn_LWkFoM_mZPgCYa2QHwLeARnq4IYIZAYiz0nLxjh9x5o6LEFluGL14GT4gkPIIhNXxm-BcQ27sx9NrBy7BiTGYmzD_ONxdeteK5eRTvs_cp2C4sX-FESmP53NJiXT4yPoFUXeFmpCxJrp2hFVKXp5ixXcIbyCWZs2Mz3lGZ0-OD9CHsTOyojt-7UNx1wj4oAcI3J0wXCF99ryv4qOrKO64uhR9l3i0SUnXzL_G4OaIS1CReikuRDIawwirRfEroA-pybvZ_6-FqLk5AfceXfDAfbzpo1OTbMoa6LnSKCMQ5TkpD8-WlA-Ebf_LdeoI2xC2AcKY4D5E-_tsj0buTtOAJoDtQRlhh5EH1WlcdF0QxiLyPs6F1i9DNjr7G0UgrI0_CWuVEXqSeDt4msY0rKw9cB-UOeXnmEJHeVV1SidR6PmCLZ-CjUBScKIzoWTb1tlhxr4DUn15tonRXrnZ6ycK6-TzMn2zc3mEQV8ckqk6znUS2vz4-tA8PUSZDSoAh246gcOIFIKFcwhjIpm1hLUnFc5Tlws73Mr6VL3yfkJPWAs8LZZEAoQzgnDcn6Hj4k9wXGBOaPMUuPgDchrGuY80nwfqxyLrSxciAiCsPdshEiqkOKMhrG2_Nt_-Q1jbTUmxbRdnre2TRrJeFJAFp0aNMNpXdKPYrDPVDRlXb3XOcppTyHBQIbPdb8j63iFmvXVDjLXaukwqfjLWByU8ZINDbQWP0soGK1HDqARkoxKZxhfUwCCbxyUT4wTjq6shc-jt5ARmUrl_UoFWXTTHCghrWQHZ0Ds-YLaMFimPXGvI7P3I5xayN-h31YfDuKkTFRkrIn_onI0agMnwpGQL-IZiCgjCDgM3aVQevz8T1jZd6r_j4_-P4GMPjzDYl6WrViIoM_-jxqVnL_8TcQeGmHpUGj34SQj0vp-0fs9Xcl_KXbnjK9wX9Xq3qep1vVmd91Vdy3WNm0qWrKp4v-YVQyx3tKabTdHhSu0ZZRXdFEVRVXW1yYUU9XZT9l3FZEm7jqwpDlzpPAozt-60SpLcF-uyXtOV5h1qn14SGEv0kLLpnY3bWsapro4rt0-i7qaTJ2uqlQ_-li2ooNNLxhxcHaF5enr4-fz4_Ru8ntEs-znJPxIU2YDxKuhEVni1IFXfo4srJi4Rn68mp_f_ftyW8l727H8BAAD__2rVxY8">