LI82712: USING ERROR STOP CODE CAUSES TRAP

APAR status

• Closed as program error.

Error description

• When using error stop code when executed the program will cause
  a TRAP as shown below.
  The program should execute and produce the ERROR STOP "message".
  
  ===== TESTCASE:
  $ cat spec.f90
  
  module finalizable_m
    !! This module supports the
  specification_expression_finalization main program
    !! (at the bottom of this file), which in turn supports the
  check_specification_expression
    !! unit-test function in ../test/compiler_test.f90.
    implicit none
  
    private
    public :: finalizable_t, component
  
    type finalizable_t
      private
      integer, pointer :: component_ => null()
    contains
      final :: finalize
    end Type
  
    interface finalizable_t
      module procedure construct
    end interface
  
  contains
  
    pure function construct(component) result(finalizable)
      integer, intent(in) :: component
      type(finalizable_t) finalizable
      allocate(finalizable%component_, source = component)
    end function
  
    pure function component(self) result(self_component)
      type(finalizable_t), intent(in) :: self
      integer self_component
      if (.not. associated(self%component_)) error stop
  "component: unassociated component"
      self_component = self%component_
    end function
  
    pure subroutine finalize(self)
      type(finalizable_t), intent(inout) :: self
      if (associated(self%component_)) deallocate(self%component_)
      error stop "finalize: intentional error termination to
  verify finalization"
    end subroutine
  
  end module
  
  program specification_expression_finalization
    !! Test the finalization of a function result in a
  specification expression
    use finalizable_m, only : finalizable_t, component
    implicit none
  
    call finalize_specification_expression_result
  
  contains
  
    subroutine finalize_specification_expression_result
      real tmp(component(finalizable_t(component=0))) !! Finalizes
  the finalizable_t function result
      real eliminate_unused_variable_warning
      tmp = eliminate_unused_variable_warning
    end subroutine
  
  end program
  $
  
  ===== ACTUAL OUTPUT:
  $ xlf2003_r spec.f90 -o spec -g
  $ ./spec
  Trace/BPT trap(coredump)
  $
  
  ===== EXPECTED OUTPUT:
  $ xlf2008_r spec_orig.f90
  finalizable_m === End of Compilation 1 ===
  specification_expression_finalization === End of Compilation 2
  ===
  1501-510 Compilation successful for file spec_orig.f90.
  $ ./a.out
  ERROR STOP 2
  $
  

Local fix

• ===== WORKAROUND:
  The client can work around this issue by replacing the two ERROR
  STOP statements in the code to use integer stop code. For
  example, after replacing the first one inside the function
  component() with "ERROR STOP 1", and the second one inside the
  subroutine finalize() with "ERROR STOP 2", the client  observes
  the expected behavior:
  
  $ xlf2008_r spec_orig.f90
  
  finalizable_m === End of Compilation 1 ===
  specification_expression_finalization === End of Compilation 2
  ===
  1501-510 Compilation successful for file spec_orig.f90.
  $ ./a.out
  ERROR STOP 2
  
  The client can use the integer stop code in the meantime, it
  seems that using character just hit a bug in this particular
  case.
  

Problem summary

• USERS AFFECTED:
  Users who use ERROR STOP with character string return code
  inside a PURE procedure.
  
  PROBLEM DESCRIPTION:
  When running the compiled testcase above with ERROR stop code it
  crashes with a TRAP.
  

Problem conclusion

• The compiler was fixed by excluding ERROR STOP from PURE
  procedure checking.
  

Temporary fix

Comments

APAR Information

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

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

Fix information

• Fixed component name

  XL FORTRAN LINU

• Fixed component ID

  5725C7510

Applicable component levels