LI75332: APPLICATION COREDUMPS WHILE ALLOCATING TEXT TO AN ARRAY

February 2010 Update for XL Fortran Advanced Edition for Linux, V11.1
February 2011 Update for XL Fortran Advanced Edition for Linux, V11.1

APAR status

• Closed as program error.

Error description

• While attempting to allocate text to an array element, if
  certain conditions are present (noted in the testcase),
  running the application will result in a segmentation fault, or
  will not be filled with the right value.
  
  ===== Start of test.f90=====
  In:
  
  module m
    type menu
      character(len=:), allocatable :: texte
    end type menu
  
    type(menu), dimension(1) :: v
    !type(menu) :: obj
  
    integer choix
  
  contains
  
    subroutine init_menu
      !obj%texte = "obj value"
      v(1)%texte = "v1 value"
      PRINT*,v(1)
    end subroutine init_menu
  
  end module m
  !
  program p
    use m
  
    call init_menu
  
  end program p
  =========End of test.f90=======
  
  ===== COMPILE COMMAND:
  xlf90 test.f90
  
  ===== ACTUAL OUTPUT:
  Segmentation fault(coredump) or blank
  
  ===== EXPECTED OUTPUT:
  v1 value
  

Local fix

• Modifying the test case to the following can be used as a
  workaround:
  
  module m
    type menu
      character(len=:), allocatable :: texte
    end type menu
  
    type(menu), dimension(1) :: v
    !type(menu) :: obj
  
    integer choix
  
  contains
  
    subroutine init_menu
      !allocate(obj%texte, source="Calcul valeurs propres d'une
  matrice
  complexe")
      allocate(v(1)%texte, source="Calcul valeurs propres d'une
  matrice
  complexe")
    end subroutine init_menu
  
  end module m
  !
  program p
    use m
  
    call init_menu
  
  end program p
  

Problem summary

• Users who declare an array of derived type which
  contains allocatable component and the entity is used
  before explicitly allocated are affected by this issue.
  
  
  In auto-allocating the entity, the offset of
  the component is not calculated correctly.
  

Problem conclusion

• The offset problem is now fixed.
  

Temporary fix

Comments

APAR Information

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

  IZ49926

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

Fix information

• Fixed component name

  XL FORTRAN SLES

• Fixed component ID

  5724S7400

Applicable component levels

• RB10 PSN IZ49926

     UP06/09/13