[Patch, fortran] PR82275 - gfortran rejects valid & accepts invalid reference to dimension-remapped type SELECT TYPE selector

[Patch, fortran] PR82275 - gfortran rejects valid & accepts invalid reference to dimension-remapped type SELECT TYPE selector

[Paul Richard Thomas]

[-- Attachment #1: Type: text/plain, Size: 726 bytes --]

This patch is verging on 'obvious' since there was no attempt being
made to detect dimensions where the array reference of the selector is
an element. In fact, I made an attempt when the bug was first reported
to do this, Not realizing that the elements were coming through as
DIMEN_UNKNOWN, the attempt failed. This is now catered for.

Bootstrapped and regtested on FC27/x86_64. OK for all active branches?

Paul

2018-05-19  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/82275
    * match.c (gfc_match_type_spec): Go through the array ref and
    decrement 'rank' for every dimension that is an element.

2018-05-19  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/82923
    * gfortran.dg/select_type_42.f90: New test.

[-- Attachment #2: submit.diff --]
[-- Type: text/x-patch, Size: 3520 bytes --]

Index: gcc/fortran/match.c
===================================================================
*** gcc/fortran/match.c	(revision 260317)
--- gcc/fortran/match.c	(working copy)
*************** gfc_match_type_spec (gfc_typespec *ts)
*** 2118,2124 ****
       or list item in a type-list of an OpenMP reduction clause.  Need to
       differentiate REAL([KIND]=scalar-int-initialization-expr) from
       REAL(A,[KIND]) and REAL(KIND,A).  Logically, when this code was
!      written the use of LOGICAL as a type-spec or intrinsic subprogram 
       was overlooked.  */
  
    m = gfc_match (" %n", name);
--- 2118,2124 ----
       or list item in a type-list of an OpenMP reduction clause.  Need to
       differentiate REAL([KIND]=scalar-int-initialization-expr) from
       REAL(A,[KIND]) and REAL(KIND,A).  Logically, when this code was
!      written the use of LOGICAL as a type-spec or intrinsic subprogram
       was overlooked.  */
  
    m = gfc_match (" %n", name);
*************** copy_ts_from_selector_to_associate (gfc_
*** 5935,5940 ****
--- 5935,5941 ----
  {
    gfc_ref *ref;
    gfc_symbol *assoc_sym;
+   int rank = 0;
  
    assoc_sym = associate->symtree->n.sym;
  
*************** copy_ts_from_selector_to_associate (gfc_
*** 5971,5984 ****
  	selector->rank = ref->u.ar.dimen;
        else
  	selector->rank = 0;
      }
  
!   if (selector->rank)
      {
!       assoc_sym->attr.dimension = 1;
!       assoc_sym->as = gfc_get_array_spec ();
!       assoc_sym->as->rank = selector->rank;
!       assoc_sym->as->type = AS_DEFERRED;
      }
    else
      assoc_sym->as = NULL;
--- 5972,5999 ----
  	selector->rank = ref->u.ar.dimen;
        else
  	selector->rank = 0;
+ 
+       rank = selector->rank;
      }
  
!   if (rank)
      {
!       for (int i = 0; i < ref->u.ar.dimen + ref->u.ar.codimen; i++)
! 	if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT
! 	    || (ref->u.ar.dimen_type[i] == DIMEN_UNKNOWN
! 		&& ref->u.ar.end[i] == NULL
! 		&& ref->u.ar.stride[i] == NULL))
! 	  rank--;
! 
!       if (rank)
! 	{
! 	  assoc_sym->attr.dimension = 1;
! 	  assoc_sym->as = gfc_get_array_spec ();
! 	  assoc_sym->as->rank = rank;
! 	  assoc_sym->as->type = AS_DEFERRED;
! 	}
!       else
! 	assoc_sym->as = NULL;
      }
    else
      assoc_sym->as = NULL;
Index: gcc/testsuite/gfortran.dg/select_type_42.f90
===================================================================
*** gcc/testsuite/gfortran.dg/select_type_42.f90	(nonexistent)
--- gcc/testsuite/gfortran.dg/select_type_42.f90	(working copy)
***************
*** 0 ****
--- 1,26 ----
+ ! { dg-do run }
+ !
+ ! Tests the fix for PR82275.
+ ! Associating a name with a reduced-dimension section of a
+ ! multidimensional array precluded subsequent use of the name
+ ! with the appropriately reduced dimensionality and instead
+ ! required use of the (invalid) full set of original dimensions.
+ !
+ ! Contributed by Damian Rouson  <damian@sourceryinstitute.org>
+ !
+   type component
+    integer :: i
+   end type
+   type container
+     class(component), allocatable :: component_array(:,:)
+   end type
+   type(container) bag
+   type(component) section_copy
+   allocate(bag%component_array, source = reshape ([component(10), component (100)], [1,2]))
+   select type(associate_name=>bag%component_array(1,:))
+     type is (component)
+       section_copy = associate_name(2)  ! gfortran rejected valid
+ !      section_copy = associate_name(1,1)! gfortran accepted invalid
+   end select
+   if (section_copy%i .ne. 100) stop 1
+ end

Re: [Patch, fortran] PR82275 - gfortran rejects valid & accepts invalid reference to dimension-remapped type SELECT TYPE selector

[Steve Kargl]

On Sat, May 19, 2018 at 09:34:13AM +0100, Paul Richard Thomas wrote:
> This patch is verging on 'obvious' since there was no attempt being
> made to detect dimensions where the array reference of the selector is
> an element. In fact, I made an attempt when the bug was first reported
> to do this, Not realizing that the elements were coming through as
> DIMEN_UNKNOWN, the attempt failed. This is now catered for.
> 
> Bootstrapped and regtested on FC27/x86_64. OK for all active branches?
> 

OK.

-- 
Steve