Allocatable function result should not have allocatable attribute

[Harald1]

Hello,

the following code is accepted by Intel but rejected by NAG:

program main
  integer, allocatable :: p
  p = f()
  print *, allocated(p)
  print *, is_allocated(p)
  print *, is_allocated(f())    ! Invalid per F2018 8.5.3 Note 1

contains
  function f()
    integer, allocatable :: f
    allocate (f, source=42)
  end function

  logical function is_allocated(p)
    integer, allocatable :: p

    is_allocated = allocated(p)
  end function
end program

NAG prints:

NAG Fortran Compiler Release 7.1(Hanzomon) Build 7101
Error: pr109500.f90, line 6: Expected an ALLOCATABLE variable for argument P (no. 1) of IS_ALLOCATED
[NAG Fortran Compiler error termination, 1 error]

Indeed Fortran 2018, 8.5.1, Note 1 says:

Only variables and components can have the ALLOCATABLE attribute. The result of referencing a func-
tion whose result variable has the ALLOCATABLE attribute is a value that does not itself have the
ALLOCATABLE attribute.

 At least in standard conformance mode Intel should diagnose this, but ifort silently accepts it, and ifx crashes with:

pr109500.f90(6): 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.
  print *, is_allocated(f())    ! Invalid per F2018 8.5.3 Note 1
--^
compilation aborted for pr109500.f90 (code 3)

(traceback elided).

[FortranFan]

Intel team,

Perhaps you will consider the following variant also toward the bug incident report.  Note the lines marked A, B, and C.  A conforming processor shall detect and report noncompliance with each of these 3 cases, but IFORT fails to do so with C.  As OP stated, IFX encounters an ICE with C.

   !call sub( 0 )    !<-- A
   !call sub( f1() ) !<-- B
   call sub( f2() )  !<-- C
contains
   subroutine sub( a )
      integer, allocatable :: a
   end subroutine
   function f1() result(r)
      integer :: r
      r = 42
   end function
   function f2() result(r)
      integer, allocatable :: r
      r = 42
   end function
end 

C:\temp>ifx /c /free /standard-semantics p.f
Intel(R) Fortran Compiler for applications running on Intel(R) 64, Version 2023.1.0 Build 20230320
Copyright (C) 1985-2023 Intel Corporation. All rights reserved.

 #0 0x00007ff6012d075a (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x30075a)
 #1 0x00007ff6012d072a (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x30072a)
 #2 0x00007ff6011f66d4 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x2266d4)
 #3 0x00007ff6011c9c3a (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x1f9c3a)
 #4 0x00007ff601210d48 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x240d48)
 #5 0x00007ff6012563d8 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x2863d8)
 #6 0x00007ff601256a30 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x286a30)
 #7 0x00007ff601255480 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x285480)
 #8 0x00007ff60124bbfc (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x27bbfc)
 #9 0x00007ff601249de9 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x279de9)
#10 0x00007ff6012491bc (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x2791bc)
#11 0x00007ff60132206f (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x35206f)
#12 0x00007ff60132265c (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x35265c)
#13 0x00007ff601324b66 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x354b66)
#14 0x00007ff60132206f (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x35206f)
#15 0x00007ff60131effd (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x34effd)
#16 0x00007ff60132206f (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x35206f)
#17 0x00007ff60119f90a (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x1cf90a)
#18 0x00007ff60119f34a (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x1cf34a)
#19 0x00007ff60138c31e (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x3bc31e)
#20 0x00007ff6037f6060 (C:\PROGRA~2\Intel\oneAPI\compiler\latest\windows\bin-llvm\xfortcom.exe+0x2826060)
#21 0x00007ff84f307614 (C:\WINDOWS\System32\KERNEL32.DLL+0x17614)
#22 0x00007ff84f5426a1 (C:\WINDOWS\SYSTEM32\ntdll.dll+0x526a1)

p.f(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( f2() )  !<-- C
---^
compilation aborted for p.f (code 3)

C:\temp>ifort /c /free /standard-semantics p.f
Intel(R) Fortran Intel(R) 64 Compiler Classic for applications running on Intel(R) 64, Version 2021.9.0 Build 20230302_000000
Copyright (C) 1985-2023 Intel Corporation.  All rights reserved.


C:\temp>

[Barbara_P_Intel]

The ICE with ifx is melted (gone) for both reproducers in the next release.

Checking on the missing error message...

[Barbara_P_Intel · Accepted solution]

Bug filed for the missing error message, CMPLRLLVM-46937, with both reproducers. I'll let you know when it's fixed.

[Barbara_P_Intel]

@Harald1 and @FortranFan, when you install the compilers that were released this week you will find error messages for the invalid code in both reproducers.

Please check out 2024.0!

[Harald1]

Confirmed.  I now get appropriate error messages for the testcase.

Thanks!