Re: [PATCH 1/1] do not add common-main to lib

From: Jeff King <peff@peff.net>
Date: Aug 15, 2016, 12:02 UTC
Message-ID: <20160815120223.4lr23aiqmqzjprch@sigill.intra.peff.net>
In-Reply-To: <20160815075207.31280-1-list@eworm.de>

On Mon, Aug 15, 2016 at 09:52:07AM +0200, Christian Hesse wrote:

Show 7 quoted lines

> From: Christian Hesse <mail@eworm.de>
> 
> Commit 08aade70 (mingw: declare main()'s argv as const) changed
> declaration of main function. This breaks linking external projects
> (e.g. cgit) to libgit.a with:
> 
> error: Multiple definition of `main'

I'd expect the culprit is actually 3f2e229 (add an extra level of indirection to main(), 2016-07-01).

> So do not add common-main to lib and let projects have their own
> main function.

That is certainly an option, but I think it means that those projects are potentially buggy in the same way that some git commands were prior to the common-main series. Namely, the common main() may do some run-time setup that parts of libgit.a assume has been done.

I would not be surprised if cgit crashes on Windows, for instance, for the reasons detailed in 650c449 (common-main: call git_extract_argv0_path(), 2016-07-01). I would also not be surprised if nobody actually builds cgit on Windows. :)

The "right" way to do it (according to the way libgit.a views the world) is for cgit's main to become cmd_main(), and let libgit.a do its run-time startup before getting there.

-Peff