LI75921: -C CAUSING UNEXPECTED TRACE/BPT TRAP

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 using -C or -qcheck, the final executable traps without any
  specific reason.
  
  =====Compile Line=======
  xlf90 -c -g -C type_module.f90
  xlf90 -c -g -C proc_module.f90
  xlf90 -c -g -C main.f90
  xlf90 -o main type_module.o proc_module.o main.o
  
  =====Testcase===========
  $cat type_module.f90
  module type_module
  
  implicit none
  
  type layer
   character (len=128) :: name
   character (len=12) :: type
  end type layer
  
  end module type_module
  $
  
  $cat proc_module.f90
  module proc_module
  use type_module
  implicit none
  
  contains
  
  function simple_function (layers, obj_size) result(jstatus)
  
  type(layer), dimension(:), intent(inout) :: layers
  integer, dimension(:), intent(in) :: obj_size
  integer :: jstatus
  
  jstatus = 0
  
  
  end function simple_function
  
  end module proc_module
  $
  
  $cat main.f90
  program main
  
  use type_module
  use proc_module
  
  implicit none
  
  type(layer), dimension(1) :: data_layers
  integer :: istat
  integer, dimension(2) :: num_array
  
  istat = 0
  num_array = (/12, 7/)
  
  data_layers(1)%name = 'Layer Name'
  data_layers(1)%type = 'float32'
  
  istat = simple_function (data_layers(1:1), num_array) + 5
  print *, '1) simple_function status: ', istat
  
  !if you replace num_array with its actual value, it traps
  istat = simple_function (data_layers(1:1), (/12,7/)) + 5
  print *, '2) simple_function status: ', istat
  
  end program main
  $
  
  ===== ACTUAL OUTPUT:
  $ ./main
   1) simple_function status:  5
  Trace/BPT trap
  $
  
  ===== EXPECTED OUTPUT:
  $ ./main
   1) simple_function status:  5
   2) simple_function status:  5
  $
  

Local fix

• N/A
  

Problem summary

• USERS AFFECTED:
  Users compiling with -qcheck may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  The conformability check within the compiler was incorrectly
  considering function arguments in certain expressions leading
  the
  compiler to insert an un-ncessary trap into the code that
  causes it to trap and runtime.
  

Problem conclusion

• The -qcheck option has been corrected to handle the above
  mentioned issue.
  

Temporary fix

Comments

APAR Information

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

  IZ80115

• 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 PSN IZ80115

     UP06/09/13