[Bug fortran/54992] [4.8 Regression] [OOP] Wrong offset in the array offset calculation when using nonclass%class(index)%nonclass

[pault at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54992



Paul Thomas <pault at gcc dot gnu.org> changed:



           What    |Removed                     |Added

----------------------------------------------------------------------------

         AssignedTo|unassigned at gcc dot       |pault at gcc dot gnu.org

                   |gnu.org                     |



--- Comment #4 from Paul Thomas <pault at gcc dot gnu.org> 2012-12-26 17:56:31 
UTC ---

This is another result of the underlying bug unearthed in PR54990.



Index: gcc/fortran/trans-array.c

===================================================================

*** gcc/fortran/trans-array.c    (revision 194721)

--- gcc/fortran/trans-array.c    (working copy)

*************** static tree

*** 3099,3112 ****

  build_array_ref (tree desc, tree offset, tree decl)

  {

    tree tmp;



    /* Class array references need special treatment because the assigned

       type size needs to be used to point to the element.  */ 

    if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (desc))

      && TREE_CODE (desc) == COMPONENT_REF

!     && GFC_CLASS_TYPE_P (TREE_TYPE (TREE_OPERAND (desc, 0))))

      {

!       tree type = gfc_get_element_type (TREE_TYPE (desc));

        tmp = TREE_OPERAND (desc, 0);

        tmp = gfc_get_class_array_ref (offset, tmp);

        tmp = fold_convert (build_pointer_type (type), tmp);

--- 3099,3118 ----

  build_array_ref (tree desc, tree offset, tree decl)

  {

    tree tmp;

+   tree type;

+ 

+   type = TREE_TYPE (TREE_OPERAND (desc, 0));

+   if (TYPE_CANONICAL (type)

+       && GFC_CLASS_TYPE_P (TYPE_CANONICAL (type)))

+     type = TYPE_CANONICAL (type);



    /* Class array references need special treatment because the assigned

       type size needs to be used to point to the element.  */ 

    if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (desc))

      && TREE_CODE (desc) == COMPONENT_REF

!     && GFC_CLASS_TYPE_P (type))

      {

!       type = gfc_get_element_type (TREE_TYPE (desc));

        tmp = TREE_OPERAND (desc, 0);

        tmp = gfc_get_class_array_ref (offset, tmp);

        tmp = fold_convert (build_pointer_type (type), tmp);



fixes it.  As remarked in PR54990, I do not know why this regression has

occurred.  Evidently, GFC_CLASS_TYPE_P is not being transferred from the

canonical type, whereas this was happening before the regression (or a new type

was not being generated?).  I will investigate more.



I have taken this PR.



Cheers



Paul