LI75929: APPLICATION SEGFAULT WITH XLF

January 2012 Update for XL Fortran for Linux, V12.1
January 2011 Update for XL Fortran for Linux, V12.1
June 2011 Update for XL Fortran for Linux, V12.1
XL Fortran for Linux Fix Pack 8 (January 2014 Update) for 12.1

APAR status

• Closed as program error.

Error description

• When compiling the test case with xlf, xlf90 etc, the executable
  segfaults at runtime.
  
  ===== COMPILE COMMAND:
  xlf -g xlfbug.f90
  
  ===== TESTCASE:
  $cat xlfbug.f90
        module sub
          public :: xlfbug
          contains
            subroutine xlfbug(my_optarg)
              implicit none
              integer, optional, intent(in) :: my_optarg
              call xlfbug2(my_optarg)
              contains
            subroutine xlfbug2(my_optarg)
              implicit none
              integer, optional, intent(in) :: my_optarg
              write(*,*) "Hello World"
            end subroutine xlfbug2
            end subroutine xlfbug
        end module sub
        program xlf_optarg
          use sub
          call xlfbug
        end program xlf_optarg
  $
  
  
  
  
  ===== ACTUAL OUTPUT:
  $./a.out
  Memory fault(coredump)
  $
  
  ===== EXPECTED OUTPUT:
  $ ./a.out
   Hello World
  $
  

Local fix

• Temporary workaround:  remove intent(in)
  

Problem summary

• USERS AFFECTED:
  Users of XL Fortran on Linux may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  Procedures passing a non-present optional argument to an
  internal procedure expecting an
  intent(in) optional dummy argument will fail with a
  segmentation fault on Linux.
  

Problem conclusion

• The compiler has been fixed to address the above case.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  LI75629

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL FORTRAN RHEL

• Fixed component ID

  5724U8410

Applicable component levels

• RC10 PSY

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