[Bug fortran/29458] Spurious -Wuninitialized warning for implied do-loop counter

["manu at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #9 from manu at gcc dot gnu dot org  2008-01-30 19:53 -------
I tried this:

Index: gcc/fortran/trans-array.c
===================================================================
--- gcc/fortran/trans-array.c   (revision 131893)
+++ gcc/fortran/trans-array.c   (working copy)
@@ -1246,36 +1246,27 @@ gfc_trans_array_constructor_value (stmtb
          tree end;
          tree step;
          tree loopvar;
          tree exit_label;
          tree loopbody;
-         tree tmp2;
-         tree tmp_loopvar;

          loopbody = gfc_finish_block (&body);

          if (c->iterator->var->symtree->n.sym->backend_decl)
            {
-             gfc_init_se (&se, NULL);
-             gfc_conv_expr (&se, c->iterator->var);
-             gfc_add_block_to_block (pblock, &se.pre);
-             loopvar = se.expr;
+             loopvar = gfc_typenode_for_spec (&c->iterator->var->ts);
+             loopvar = gfc_create_var (loopvar,
c->iterator->var->symtree->n.sym->name);
            }
          else
            {
              /* If the iterator appears in a specification expression in
                 an interface mapping, we need to make a temp for the loop
                 variable because it is not declared locally.  */
              loopvar = gfc_typenode_for_spec (&c->iterator->var->ts);
              loopvar = gfc_create_var (loopvar, "loopvar");
            }

-         /* Make a temporary, store the current value in that
-            and return it, once the loop is done.  */
-         tmp_loopvar = gfc_create_var (TREE_TYPE (loopvar), "loopvar");
-         gfc_add_modify_expr (pblock, tmp_loopvar, loopvar);
-
          /* Initialize the loop.  */
          gfc_init_se (&se, NULL);
          gfc_conv_expr_val (&se, c->iterator->start);
          gfc_add_block_to_block (pblock, &se.pre);
          gfc_add_modify_expr (pblock, loopvar, se.expr);
@@ -1293,10 +1284,12 @@ gfc_trans_array_constructor_value (stmtb
          /* If this array expands dynamically, and the number of iterations
             is not constant, we won't have allocated space for the static
             part of C->EXPR's size.  Do that now.  */
          if (dynamic && gfc_iterator_has_dynamic_bounds (c->iterator))
            {
+             tree tmp2;
+
              /* Get the number of iterations.  */
              tmp = gfc_get_iteration_count (loopvar, end, step);

              /* Get the static part of C->EXPR's size.  */
              gfc_get_array_constructor_element_size (&size, c->expr);
@@ -1339,13 +1332,10 @@ gfc_trans_array_constructor_value (stmtb
          gfc_add_expr_to_block (pblock, tmp);

          /* Add the exit label.  */
          tmp = build1_v (LABEL_EXPR, exit_label);
          gfc_add_expr_to_block (pblock, tmp);
-
-         /* Restore the original value of the loop counter.  */
-         gfc_add_modify_expr (pblock, loopvar, tmp_loopvar);
        }
     }
   mpz_clear (size);
 }


But something is still using the wrong 'i':

   <D.937>:;
    if (i.4D.918 > D.919)
      {
        goto L.1D.922;
      }
    else
      {

      }
    D.932 = atmp.2D.915.dataD.906;
    D.938 = (integer(kind=4)D.8[0] *) D.932;
    offset.6D.939 = offset.3D.917;
    (*D.938)[offset.6D.939] = iD.902; <<===== This is the wrong "i"!!
    offset.3D.917 = offset.3D.917 + 1;
    i.4D.918 = i.4D.918 + 1;
    goto <D.937>;

I also give up. Too time-consuming understanding what is going on...


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29458