Re: allow convenient library in subdirectory

[Tom Tromey]

adl> I found this in handle_single_transform_list, but nowhere else,
adl> maybe I missed something.

I think that's the only place.  For some reason I thought there were
more, but I guess not.

adl> +  # If the resulting library lies into a subdirectory,
adl> +  # make sure this directory exists.

We'll need to do this for programs and ltlibraries at least.
Other places might need help too, but those are more complex.
For instance a _DATA item might be built.  But we can only know that
by looking at target names -- which I think we aren't ready to do.
(Maybe we'll never do that.)

Could you make this change?

adl> +sub require_build_directory
adl> +{
adl> [ ... ]
adl> +        if ($use_dependencies)
adl> +        {
adl> +            $output_rules .= ('.deps/' . $directory
adl> +                              . "/.dirstamp:\n"
adl> +                              . "address@hidden(mkinstalldirs) 
.deps/$directory\n"
adl> +                              . "\t\@: > .deps/$directory/.dirstamp\n");

I think this code should go back in handle_single_transform_list.
The reason is that the .deps directory is only used by dependency
tracking.  You might have a library in a subdir but no objects there.
In that case this code would make .deps but it wouldn't be needed.

Could you move it back?  You might need to change
require_build_directory to return a flag indicating whether the
directory already exists.

Other than this the patch looks great.

Tom