[Bug libfortran/40187] New: c_f_pointer with stride in SHAPE

[Bug libfortran/40187] New: c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

Using a SHAPE with stride doesn't work with c_f_pointer doesn't work
(modified test case from the testsuite):

$ diff -u c_f_pointer_shape_tests_4.f03
~/gcc/trunk/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_2.f03
--- c_f_pointer_shape_tests_4.f03       2009-05-18 19:55:36.000000000 +0200
+++
/home/ig25/gcc/trunk/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_2.f03   
    2007-11-17 17:27:32.000000000 +0100
@@ -29,13 +29,12 @@
     integer(c_int), value :: num_rows
     integer(c_int), value :: num_cols
     integer, dimension(:,:), pointer :: myArrayPtr
-    integer(c_long_long), dimension(3) :: shape
+    integer(c_long_long), dimension(2) :: shape
     integer :: i,j

     shape(1) = num_rows
-    shape(2) = -3;
-    shape(3) = num_cols
-    call c_f_pointer(cPtr, myArrayPtr, shape(1:3:2))
+    shape(2) = num_cols
+    call c_f_pointer(cPtr, myArrayPtr, shape)
     do j = 1, num_cols
        do i = 1, num_rows
           if(myArrayPtr(i,j) /= ((j-1)*num_rows)+(i-1)) call abort ()
$ gfortran
~/gcc/trunk/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_2_driver.c
c_f_pointer_shape_tests_4.f03
$ ./a.out
Aborted


-- 
           Summary: c_f_pointer with stride in SHAPE
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2009-05-18 21:20 -------
Can you attach a working example? I failed to apply your patch and figure out
which diffed file is what.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[pault at gcc dot gnu dot org]

------- Comment #2 from pault at gcc dot gnu dot org  2009-05-19 05:06 -------
(In reply to comment #1)
> Can you attach a working example? I failed to apply your patch and figure out
> which diffed file is what.
> 

Hi Tobias,

It's a reversed diff!

Hi Thomas,

Works for me on FC9/x86_64 - what platform are you reporting?

Cheers

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #3 from tkoenig at gcc dot gnu dot org  2009-05-19 17:14 -------
Created an attachment (id=17893)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17893&action=view)
Failing test case


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #4 from tkoenig at gcc dot gnu dot org  2009-05-19 17:17 -------
Created an attachment (id=17894)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17894&action=view)
Driver for failing test case (identical to c_f_pointer_shape_tests_2_driver.c)

$ gfortran c_f_pointer_shape_tests_4_driver.c c_f_pointer_shape_tests_4.f03
$ ./a.out
Aborted
$ gfortran -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../../../gcc/branches/fortran-dev/configure
--prefix=/home/ig25 --enable-languages=c,fortran --enable-maintainer-mode
Thread model: posix
gcc version 4.5.0 20090506 (experimental) (GCC)

The reason this fails is fairly obvious if you look at the code:  In
c_f_pointer_u0, there's

      for (i = 0; i < shapeSize; i++)
        {
          /* Lower bound is 1, as specified by the draft.  */
          f_ptr_out->dim[i].lbound = 1;
          /* Have to allow for the SHAPE array to be any valid kind for
             an INTEGER type.  */
#ifdef HAVE_GFC_INTEGER_1
          if (GFC_DESCRIPTOR_SIZE (shape) == 1)
            f_ptr_out->dim[i].ubound = ((GFC_INTEGER_1 *) (shape->data))[i];

which ignores the (sad) fact that shape could have a stride not equal
to one.  I found this when trying to convert this part to the array access
macros.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #5 from tkoenig at gcc dot gnu dot org  2009-05-19 17:18 -------
Since I'm working in this area anyway, I might as well take this.


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |tkoenig at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-05-19 17:18:27
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #6 from tkoenig at gcc dot gnu dot org  2009-05-27 05:27 -------
Subject: Bug 40187

Author: tkoenig
Date: Wed May 27 05:27:31 2009
New Revision: 147894

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=147894
Log:
2009-05-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR libfortran/40187
        * intrinsics/iso_c_binding.c (c_f_pointer_u0):  Take care
        of stride in "shape" argument.

2009-05-27  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR libfortran/40187
        * gfortran.dg/c_f_pointer_shape_tests_4.f03:  New file.
        * gfortran.dg/c_f_pointer_shape_tests_4_driver.c:  New file.


Added:
    trunk/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_4.f03
    trunk/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_4_driver.c
Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/intrinsics/iso_c_binding.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #7 from tkoenig at gcc dot gnu dot org  2009-05-30 13:17 -------
Subject: Bug 40187

Author: tkoenig
Date: Sat May 30 13:17:14 2009
New Revision: 148002

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=148002
Log:
2009-05-30  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/37577
        PR libfortran/40187
        * runtime/in_pack_generic (internal_pack):  Remove unnecessary
        test for stride == 0.
        * runtime/in_unpack_generic.c (internal_unpack):  Likewise.
        * intrinsics/iso_c_binding.c (c_f_pointer_u0):  Take care
        of stride in "shape" argument.  Use array access macros for
        accessing array descriptors.
        * libgfortran.h (struct descriptor_dimension):  Change stride
        to _stride, lbound to _lbound and ubound to _ubound.
        (GFC_DIMENSION_LBOUND):  Use new name(s) in struct
        descriptor_dimension.
        (GFC_DIMENSION_UBOUND):  Likewise.
        (GFC_DIMENSION_STRIDE):  Likewise.
        (GFC_DIMENSION_EXTENT):  Likewise.
        (GFC_DIMENSION_SET):  Likewise.
        (GFC_DESCRIPTOR_LBOUND):  Likewise.
        (GFC_DESCRIPTOR_UBOUND):  Likewise.
        (GFC_DESCRIPTOR_EXTENT):  Likewise.
        (GFC_DESCRIPTOR_STRIDE):  Likewise.
        * io/transfer.c (transfer_array):  Use array access macros.
        Use byte-sized strides.

2009-05-30  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR libfortran/40187
        * gfortran.dg/c_f_pointer_shape_tests_4.f03:  New file.
        * gfortran.dg/c_f_pointer_shape_tests_4_driver.c:  New file.


Added:
   
branches/fortran-dev/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_4.f03
   
branches/fortran-dev/gcc/testsuite/gfortran.dg/c_f_pointer_shape_tests_4_driver.c
Modified:
    branches/fortran-dev/gcc/testsuite/ChangeLog.fortran-dev
    branches/fortran-dev/libgfortran/ChangeLog.dev
    branches/fortran-dev/libgfortran/intrinsics/iso_c_binding.c
    branches/fortran-dev/libgfortran/io/transfer.c
    branches/fortran-dev/libgfortran/libgfortran.h
    branches/fortran-dev/libgfortran/runtime/in_pack_generic.c
    branches/fortran-dev/libgfortran/runtime/in_unpack_generic.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #8 from tkoenig at gcc dot gnu dot org  2009-06-07 14:24 -------
Does this need a 4.4 backport?  I'm inclined to think not.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[burnus at gcc dot gnu dot org]

------- Comment #9 from burnus at gcc dot gnu dot org  2009-06-07 14:37 -------
> Does this need a 4.4 backport?  I'm inclined to think not.

Good question. As it is no regression, backporting is not required; it is a
wrong-code bug, but strides are rather special. Thus for me either is OK -
backporting or just closing as FIXED.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187

[Bug libfortran/40187] c_f_pointer with stride in SHAPE

[tkoenig at gcc dot gnu dot org]

------- Comment #10 from tkoenig at gcc dot gnu dot org  2009-07-27 09:11 -------
Closing (fixed).


-- 

tkoenig at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40187