[Patch, fortran] PR66681 - Wrong result in assigning this_image() to a complex coarray

[Paul Richard Thomas]

Dear All,

This is something of a corner case, where gfc_conv_expr comes back
with a SAVE_EXPR, in the case of complex, scalar, coarray lvalues. The
first field of the SAVE_EXPR is a perfectly viable expression to
assign to, so I have taken that. If anybody out there has a better
solution, please speak up! The testcase is good, anyway....

Discussed on https://groups.google.com/forum/#!topic/opencoarrays/Cl2iK3OfUTs

Bootstrapped and regtested on FC21/x86_64 - OK for trunk?

Paul

2015-09-08  Paul Thomas  <pa...@gcc.gnu.org>

    PR fortran/66681
    * trans-expr.c (gfc_trans_assignment_1): If the lvalue is a
    complex type and a save_expr, take the field to be assigned to.

2015-09-08  Paul Thomas  <pa...@gcc.gnu.org>

    PR fortran/66681
    * gfortran.dg/coarray_40.f90: New test.

Index: gcc/fortran/trans-expr.c
===================================================================
*** gcc/fortran/trans-expr.c    (revision 227511)
--- gcc/fortran/trans-expr.c    (working copy)
*************** gfc_trans_assignment_1 (gfc_expr * expr1
*** 9269,9274 ****
--- 9269,9281 ----
        gfc_add_block_to_block (&loop.post, &rse.post);
      }
  
+   /* Complex scalar coarrays sometimes produce a SAVE_EXPR on type conversion.
+      Take the expression to assign to.  */
+   if (TREE_CODE (lse.expr) == SAVE_EXPR
+       && TREE_CODE (TREE_TYPE (lse.expr)) == COMPLEX_TYPE
+       && expr1->symtree->n.sym->attr.codimension)
+     lse.expr = TREE_OPERAND (lse.expr, 0);
+ 
    tmp = gfc_trans_scalar_assign (&lse, &rse, expr1->ts,
                                 expr_is_variable (expr2) || scalar_to_array
                                 || expr2->expr_type == EXPR_ARRAY,
Index: gcc/testsuite/gfortran.dg/coarray_40.f90
===================================================================
*** gcc/testsuite/gfortran.dg/coarray_40.f90    (revision 0)
--- gcc/testsuite/gfortran.dg/coarray_40.f90    (working copy)
***************
*** 0 ****
--- 1,11 ----
+ ! { dg-do compile }
+ ! { dg-options "-fcoarray=single -fdump-tree-original" }
+ ! Test the fix for PR66681.
+ !
+ ! Contributed by Damian Rouson  <dam...@sourceryinstitute.org>
+ !
+   complex a[*]
+   a = this_image ()
+   print *,this_image (),a
+ end
+ ! { dg-final { scan-tree-dump-times "SAVE_EXPR" 0 "original" } }