From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?iso-8859-1?Q?Llu=EDs?= Batlle i Rossell <viric@viric.name>
Subject: Re: CMAKE_LIBRARY_PATH & co.
Date: Mon, 14 Oct 2013 09:23:05 +0200
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To: Ludovic =?iso-8859-1?Q?Court=E8s?= <ludo@gnu.org>
Cc: guix-devel@gnu.org

On Mon, Oct 14, 2013 at 09:15:25AM +0200, Ludovic Court=C3=A8s wrote:
> Andreas Enge <andreas@enge.fr> skribis:
>=20
> > commit e78fd4ca636a19bc286747f8d91bda22cd8f08fd
> > Author: Andreas Enge <andreas@enge.fr>
> > Date:   Sun Oct 13 18:02:49 2013 +0200
> >
> >     guix: Make cmake build system aware of usual paths.
> >    =20
> >     *  guix/build/cmake-build-system.scm (configure): Set CMAKE_LIBRA=
RY_PATH to
> >          LIBRARY_PATH and CMAKE_INCLUDE_PATH to CPATH.
>=20
> I think this was discussed on IRC yesterday, but I=E2=80=99m not sure I=
 got it:
> are these needed because CMake explicitly looks for files in these
> directories instead of just running the compiler?
>=20
> That would be a serious flaw of CMake.

Right; for what I understand, FIND_LIBRARY, and FIND_PATH, look for files=
 in
specific directories. Then cmake takes a decision based in what it finds.=
 A
shared object, a static lib, ...

For header files, you can do:
FIND_PATH(HEADERS file.h)  # Finds the directory having that file
INCLUDE_DIRECTORIES(${HEADERS})  # Adds the respective -I flag in compila=
tion

It may be related to cmake being able to tune very narrowly the -I/-L fla=
gs per
project target.

I'm not that anti-cmake; I find the approach of "look for files" quite ea=
sy to
understand. :)