[Patch, Fortran] PR fotran/35820 again: memory leak while resolving nested foralls.

[Paul Richard Thomas]

Mikael,


> I come back to this PR.

> The second one was it was freeing the var_expr elements at the end of
> the most nested forall construct, which is wrong if there are more than
> one nested forall constructs. This one was found (that's what I think
> looking at his patch) by Paul here
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35820#c5
> However, it was not catch by my previous patch.

I was trying, slowly, to get my head around this:-)  I could not
understand how it could have been fixed.

>
> With the attached one, only the memory allocated at the beginning of
> gfc_resolve_forall is released at the end.
>
> For Dominique, one can add this to make a memory leak results in an ICE:
>
> Index: resolve.c
> ===================================================================
> --- resolve.c   (révision 141259)
> +++ resolve.c   (copie de travail)
> @@ -6264,6 +6264,9 @@
>       var_expr[nvar] = gfc_copy_expr (fa->var);
>
>       nvar++;
> +
> +      /* No memory leak.  */
> +      gcc_assert (nvar <= total_var);
>     }
>

This is exactly what is needed.

>   /* Resolve the FORALL body.  */
>
> With this patchlet, trunk is ICEing with test.f (attached) and
> nested_forall_1.f which I add to the testsuite (see patch).

Let me try to run through the logic tonight - it looks OK at first
glance, except that you need the module clean-up line in the testcase.
 Look at the last line(s) of any of the testsuite that have modules or
the testcase notes on the gfortran wiki.

Many thanks

Paul