ICE on invalid use of optional dummy with VALUE attribute, bind(c) procedure

[Harald1]

Hello,

the following snippet crashes ifx after emitting a warning for the invalid code:

program p
  implicit none
  call sub ()      ! <- needed for ICE
contains
  subroutine sub (x) bind(c)
    character, value, optional :: x     ! Violates F2018:C865
    if (present(x)) stop 1
  end
end

I get:

 ifx ifort-value-optional-2.f90 -what
 Intel(R) Fortran 24.0-1238.2
ifort-value-optional-2.f90(5): warning #7937: The OPTIONAL attribute should not be used for arguments with the VALUE attribute.   [X]
  subroutine sub (x) bind(c)
------------------^
llfort_create_const_generic: error: invalid type 20
 #0 0x0000000002394d07 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x2394d07)
 #1 0x0000000002394cd6 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x2394cd6)
 #2 0x0000000002299297 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x2299297)
 #3 0x000000000229842f (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x229842f)
 #4 0x00000000022983f0 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x22983f0)
 #5 0x0000000002320719 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x2320719)
 #6 0x000000000231f718 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x231f718)
 #7 0x000000000231e76c (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x231e76c)
 #8 0x00000000023e3215 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e3215)
 #9 0x00000000023e37f5 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e37f5)
#10 0x00000000023e5f6d (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e5f6d)
#11 0x00000000023e3215 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e3215)
#12 0x00000000023e05ba (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e05ba)
#13 0x00000000023e3215 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x23e3215)
#14 0x00000000022703e6 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x22703e6)
#15 0x000000000226fd9e (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x226fd9e)
#16 0x0000000002452dbe (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x2452dbe)
#17 0x00007f0a0d78c24d __libc_start_main (/lib64/libc.so.6+0x3524d)
#18 0x00000000020ab129 (/opt/intel/oneapi/compiler/2024.0/bin/compiler/xfortcom+0x20ab129)

ifort-value-optional-2.f90(3): error #5623: **Internal compiler error: internal abort** Please report this error along with the circumstances in which it occurred in a Software Problem Report.  Note: File and line given may not be explicit cause of this error.
  call sub ()      ! <- needed for ICE
--^
compilation aborted for ifort-value-optional-2.f90 (code 3)

ifort does not crash for me.

A minor suggestion: the combination of OPTIONAL+VALUE is only invalid for bind(c) procedures, so mentioning this in the error message might be useful to users.  The standard has:

F2018: C865 A dummy argument of a procedure with the BIND attribute shall not have both the OPTIONAL and VALUE attributes.

[TobiasK]

@Harald1

thanks for reporting this. I will escalate it so that we do not ICE but cleanly abort.

[TobiasK]

@Harald1

we implemented a fix which will be included in the 2024.2 release.