• It won't be required for the scan stage will it?

No, it won’t be.

-- Gaby

From: Modules <modules-bounces@lists.isocpp.org> On Behalf Of Mathias Stearn
Sent: Wednesday, March 6, 2019 12:02 PM
To: Ben Boeckel via Modules <modules@lists.isocpp.org>
Cc: boris@codesynthesis.com; brad.king@kitware.com; WG21 Tooling Study Group SG15 <tooling@open-std.org>; Ben Boeckel <ben.boeckel@kitware.com>
Subject: Re: [isocpp-modules] [Tooling] Dependency information for module-aware build tools

On Wed, Mar 6, 2019 at 10:18 AM Nathan Sidwell <nathan@acm.org> wrote:

Yes, a BMI is required for a header import.  Textually including the
header import's original header file is not equivalent.

It won't be required for the scan stage will it? If it is, there is a bootstrapping problem because there is no good way to figure out which order to build the header-unit BMIs in if they import other header-units. I've been assuming that the scan stage will be able to just temporarily mask off the defines and replace them with the correct ones for the header-unit while scanning a file, so that scanning has no generated dependencies.