From: Boris Kolpackov <boris@codesynthesis.com>
To: Ben Boeckel <ben.boeckel@kitware.com>
Cc: gcc@gcc.gnu.org
Subject: Re: [modules] Preprocessing requires compiled header unit modules
Date: Thu, 21 Apr 2022 06:05:52 +0200 [thread overview]
Message-ID: <boris.20220421055949@codesynthesis.com> (raw)
In-Reply-To: <YhgY1lJpBIM1vnhx@megas.dev.benboeckel.internal>
Ben Boeckel <ben.boeckel@kitware.com> writes:
> However, for header unit modules, it runs into a problem that imported
> header units are required to be compiled and available in the mapper
> while scanning for dependencies.
>
> Example code:
>
> ```c++ # use-header.cpp
> module;
>
> import "header-unit.hpp";
>
> int main(int argc, char* argv[]) {
> return good;
> }
> ```
>
> There used to be no need to do this back prior to the modules landing in
> `master`, but I can see this being an oversight in the meantime.
I don't think it is. A header unit (unlike a named module) may export
macros which could affect further dependencies. Consider:
import "header-unit.hpp"; // May or may not export macro FOO.
#ifdef FOO
import "header-unit2.hpp"
#endif
next prev parent reply other threads:[~2022-04-21 4:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-24 23:46 Ben Boeckel
2022-04-21 4:05 ` Boris Kolpackov [this message]
2022-04-21 12:05 ` Ben Boeckel
2022-04-21 17:59 ` Iain Sandoe
2022-04-21 18:08 ` Ben Boeckel
2022-04-21 18:18 ` Iain Sandoe
2022-04-22 14:08 ` Boris Kolpackov
2022-04-22 15:06 ` Iain Sandoe
2022-04-25 9:20 ` Boris Kolpackov
2022-04-22 16:05 ` Ben Boeckel
2022-04-25 9:42 ` Boris Kolpackov
2022-04-25 11:34 ` Ben Boeckel
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