[m-rev.] for review: don't count non-local const_structs as using imported modules

[Julien Fischer]

On Fri, 22 Jan 2021, Zoltan Somogyi wrote:

> For review by anyone.
>
> Consts from other modules can't use imported modules.
> 
> This fixes the failure of the warnings/bug412 test case with -O5
> --intermodule-optimization.

...


> diff --git a/compiler/const_struct.m b/compiler/const_struct.m
> index 52b686681..fcad0ccfd 100644
> --- a/compiler/const_struct.m
> +++ b/compiler/const_struct.m

...

> @@ -223,12 +237,35 @@ lookup_insert_const_struct(ConstStruct, ConstNum, !Db) :-
>                  map.det_insert(ConstNum, ConstStruct, NumMap0, NumMap),
>
>                  const_struct_db_set_next_num(NextConstNum + 1, !Db),
> -                const_struct_db_set_other_struct_map(OtherMap, !Db),
> +                const_struct_db_set_noncons_proxy_map(NonConsProxyMap, !Db),
>                  const_struct_db_set_num_map(NumMap, !Db)
>              )
>          )
>      ).
> 
> +:- pred maybe_update_defined_where(defined_where::in, int::in,
> +    const_struct_db::in, const_struct_db::out) is det.
> +
> +maybe_update_defined_where(DefinedWhere, ConstNum, !Db) :-
> +    const_struct_db_get_num_map(!.Db, NumMap0),
> +    map.lookup(NumMap0, ConstNum, ConstStruct0),
> +    DefinedWhere0 = ConstStruct0 ^ cs_defined_where,
> +    % If the new definition say that this constant is derived from code

s/say/says/

> +    % in this module, then set the constant accordingly, unless its old
> +    % setting already says the same.
> +    ( if
> +        DefinedWhere = defined_in_this_module,
> +        DefinedWhere0 = defined_in_other_module
> +    then
> +        ConstStruct = ConstStruct0 ^ cs_defined_where
> +            := defined_in_this_module,
> +        map.det_update(ConstNum, ConstStruct, NumMap0, NumMap),
> +        const_struct_db_set_num_map(NumMap, !Db)
> +    else
> +        % There is nothing to update.
> +        true
> +    ).

That looks fine otherwise.

Julien.