[m-rev.] for review: Fix some problems with static terms in LLDS grades.

[Julien Fischer]

On Mon, 30 Apr 2018, Peter Wang wrote:

> diff --git a/compiler/var_locn.m b/compiler/var_locn.m
> index 507b30cdd..54b662500 100644
> --- a/compiler/var_locn.m
> +++ b/compiler/var_locn.m
> @@ -2,6 +2,7 @@
> % vim: ft=mercury ts=4 sw=4 et
> %---------------------------------------------------------------------------%
> % Copyright (C) 2000-2012 The University of Melbourne.
> +% Copyright (C) 2013-2018 The Mercury team.
> % This file may only be copied under the terms of the GNU General
> % Public License - see the file COPYING in the Mercury distribution.
> %---------------------------------------------------------------------------%
> @@ -844,14 +845,22 @@ var_locn_assign_dynamic_cell_to_var(ModuleInfo, Var, ReserveWordAtStart, Ptag,
>             LldsComment = "Allocating heap for ",
>             RegionVarCode = empty,
>             MaybeRegionRval = no
> +        ;
> +            HowToConstruct = construct_statically,
> +            % construct_statically is not normally used in LLDS grades, but
> +            % it may be set by mark_static_terms.m to support loop invariant
> +            % hoisting.

The comment at the head of mark_static_terms would suggest that's fine.
It says that while it is mainly used by the MLDS backend other parts of
the compiler may use it.

The diff is fine.

Julien.