[Bug fortran/30625] New: Array pointers to components of derived type arrays do not work

[Bug fortran/30625] New: Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

This:

type :: a
  real :: r = 3.14159
  integer :: i = 42
end type a
type(a), target :: dt(2)
integer, pointer :: ip(:)

ip => dt%i
print *, ip
end

produces
$ ./a
  1078530000          42
with gfortran, whereas the correct result should be two 42s

Paul


-- 
           Summary: Array pointers to components of derived type arrays do
                    not work
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pault at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[tkoenig at gcc dot gnu dot org]

------- Comment #1 from tkoenig at gcc dot gnu dot org  2007-01-28 20:33 -------
Confirmed.

Is this related to PR 29606?


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tkoenig at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-01-28 20:33:48
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[tobi at gcc dot gnu dot org]

------- Comment #2 from tobi at gcc dot gnu dot org  2007-01-29 00:16 -------
Wasn't there a bug for byte-sized strides in array descriptors?  This bug
should depend on it, and PR29606 as well.


-- 

tobi at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tobi at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

------- Comment #3 from pault at gcc dot gnu dot org  2007-01-29 07:50 -------
(In reply to comment #2)
> Wasn't there a bug for byte-sized strides in array descriptors?  This bug
> should depend on it, and PR29606 as well.
> 
Both of you are right about PR29606.  The byte-sized strides I do not remember.
 It is one way to go but I do not think that it is the correct one.  I think
that we need a new field in the descriptor or, maybe, a new species of
descriptor. This field could serve two functions:
(i) If present for an intrinsic type, it carries the base stride in bytes; and
(ii) If present for a derived type it carries the size in bytes.
The present size subfield should be used to carry a unique code for the type,
so that classes can be implemented, including abstract classes.

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[dfranke at gcc dot gnu dot org]

------- Comment #4 from dfranke at gcc dot gnu dot org  2007-02-01 11:28 -------
As I came across this once more: is it possible to issue a compile-time warning
that "array pointers to components of derived type arrays" are allowed by the
standard but are not yet implemented in gfortran (gfc_todo, maybe)? 

This would prevent some users (e.g. me) from using it right now. If otherwise
the code compiles fine, one silently gets unusable results ...


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org
  BugsThisDependsOn|                            |29606


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[paulthomas2 at wanadoo dot fr]

------- Comment #5 from paulthomas2 at wanadoo dot fr  2007-02-02 19:20 -------
Subject: Re:  Array pointers to components of derived type
 arrays do not work

dfranke at gcc dot gnu dot org wrote:
> ------- Comment #4 from dfranke at gcc dot gnu dot org  2007-02-01 11:28 -------
> As I came across this once more: is it possible to issue a compile-time warning
> that "array pointers to components of derived type arrays" are allowed by the
> standard but are not yet implemented in gfortran (gfc_todo, maybe)? 
>
> This would prevent some users (e.g. me) from using it right now. If otherwise
> the code compiles fine, one silently gets unusable results ...
>
>
>   
Daniel,

I'll see what I can come up with  - I have also been feeling round the
edges of how this might be cured.  Implementation of F2003 classes will
require another field in the descriptor.  I am trying to figure out how
best to do this without completely breaking the library API but I
am attempting to design this field to fulfill both functions.

Best regards

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[fxcoudert at gcc dot gnu dot org]

------- Comment #6 from fxcoudert at gcc dot gnu dot org  2007-02-10 21:18 -------
Paul, I take it you are aware of PR21881 ("Array descriptors limit derived type
sizes")... I don't fully grasp the way array descriptor work for derived types,
but I wanted to mention that PR to you... just in case.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

------- Comment #7 from pault at gcc dot gnu dot org  2007-02-11 09:52 -------
(In reply to comment #6)
> Paul, I take it you are aware of PR21881 ("Array descriptors limit derived type
> sizes")... I don't fully grasp the way array descriptor work for derived types,
> but I wanted to mention that PR to you... just in case.
> 
FX, I was aware of the problem but not of the PR; I'll be honest if I say tha I
am not sure that the size limit on derived types is an issue.  After all,
pointers or allocatable components can be used to keep the size of the derived
type down.

I think that I need to sketch out a design and post it on the list; it'll have
to be CC'd to Paul Brooks and Steven Bosscher because they are responsible for
the present layout of descriptors.  They maybe have opinions about how to
proceed.

Paul 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[jv244 at cam dot ac dot uk]

------- Comment #8 from jv244 at cam dot ac dot uk  2007-07-04 06:33 -------
target milestone 4.3.0 ?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[tkoenig at gcc dot gnu dot org]

------- Comment #9 from tkoenig at gcc dot gnu dot org  2007-08-18 18:28 -------
Some discussion is here:

http://gcc.gnu.org/ml/fortran/2007-04/msg00115.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pault at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-01-28 20:33:48         |2007-09-03 11:48:03
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

------- Comment #10 from pault at gcc dot gnu dot org  2007-09-16 09:18 -------
Subject: Bug 30625

Author: pault
Date: Sun Sep 16 09:17:49 2007
New Revision: 128523

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=128523
Log:
2007-09-16  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/29396
        PR fortran/29606
        PR fortran/30625
        PR fortran/30871
        * trans.h : Add extra argument to gfc_build_array_ref. Rename
        gfc_conv_aliased_arg to gfc_conv_subref_array_arg.  Move
        prototype of is_aliased_array to gfortran.h and rename it
        gfc_is_subref_array.  Add field span to lang_decl, add a new
        decl lang specific flag accessed by GFC_DECL_SUBREF_ARRAY_P
        and a new type flag GFC_DECL_SUBREF_ARRAY_P.
        * trans.c (gfc_build_array_ref): Add the new argument, decl.
        If this is a subreference array pointer, use the lang_decl
        field 'span' to calculate the offset in bytes and use pointer
        arithmetic to address the element.
        * trans-array.c (gfc_conv_scalarized_array_ref,
        gfc_conv_array_ref): Add the backend declaration as the third
        field, if it is likely to be a subreference array pointer.
        (gfc_conv_descriptor_dimension, gfc_trans_array_ctor_element,
        gfc_trans_array_constructor_element, structure_alloc_comps,
        gfc_conv_array_index_offset): For all other references to
        gfc_build_array_ref, set the third argument to NULL.
        (gfc_get_dataptr_offset): New function.
        (gfc_conv_expr_descriptor): If the rhs of a pointer assignment
        is a subreference array, then calculate the offset to the
        subreference of the first element and set the descriptor data
        pointer to this, using gfc_get_dataptr_offset.
        trans-expr.c (gfc_get_expr_charlen): Use the expression for the
        character length for a character subreference.
        (gfc_conv_substring, gfc_conv_subref_array_arg): Add NULL for
        third argument in call to gfc_build_array_ref.
        (gfc_conv_aliased_arg): Rename to gfc_conv_subref_array_arg.
        (is_aliased_array): Remove.
        (gfc_conv_function_call): Change reference to is_aliased_array
        to gfc_is_subref_array and reference to gfc_conv_aliased_arg to
        gfc_conv_subref_array_arg.
        (gfc_trans_pointer_assignment): Add the array element length to
        the lang_decl 'span' field.
        * gfortran.h : Add subref_array_pointer to symbol_attribute and
        add the prototype for gfc_is_subref_array.
        * trans-stmt.c : Add NULL for third argument in all references
        to gfc_build_array_ref.
        * expr.c (gfc_is_subref_array): Renamed is_aliased_array.
        If this is a subreference array pointer, return true.
        (gfc_check_pointer_assign): If the rhs is a subreference array,
        set the lhs subreference_array_pointer attribute.
        * trans-decl.c (gfc_get_symbol_decl): Allocate the lang_decl
        field if the symbol is a subreference array pointer and set an
        initial value of zero for the 'span' field.
        * trans-io.c (set_internal_unit): Refer to is_subref_array and
        gfc_conv_subref_array_arg.
        (nml_get_addr_expr): Add NULL third argument to
        gfc_build_array_ref. 
        (gfc_trans_transfer): Use the scalarizer for a subreference
        array.

2007-09-16  Paul Thomas  <pault@gcc.gnu.org>

        PR fortran/29396
        PR fortran/29606
        PR fortran/30625
        PR fortran/30871
        * gfortran.dg/subref_array_pointer_1.f90: New test.
        * gfortran.dg/subref_array_pointer_2.f90: New test.


Added:
    trunk/gcc/testsuite/gfortran.dg/subref_array_pointer_1.f90
    trunk/gcc/testsuite/gfortran.dg/subref_array_pointer_2.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/expr.c
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/fortran/trans-decl.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/fortran/trans-io.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/fortran/trans.c
    trunk/gcc/fortran/trans.h
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625

[Bug fortran/30625] Array pointers to components of derived type arrays do not work

[pault at gcc dot gnu dot org]

------- Comment #11 from pault at gcc dot gnu dot org  2007-09-16 09:39 -------
Fixed on trunk

Paul


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30625