| 1 |
On Friday 23 February 2007, Kevin F. Quinn wrote: |
| 2 |
> On Thu, 22 Feb 2007 19:08:48 +0000 |
| 3 |
> |
| 4 |
> Ciaran McCreesh <ciaranm@×××××××.org> wrote: |
| 5 |
> > The example given in ebuild(5) is: |
| 6 |
> > || ( |
| 7 |
> > |
| 8 |
> > sdl? ( media-libs/libsdl ) |
| 9 |
> > svga? ( media-libs/svgalib ) |
| 10 |
> > opengl? ( virtual/opengl ) |
| 11 |
> > ggi? ( media-libs/libggi ) |
| 12 |
> > virtual/x |
| 13 |
> > ) |
| 14 |
> |
| 15 |
> Took me a while to figure out why anyone would want to write that; the |
| 16 |
> key is that ebuild(5) says only one of the conditions is satisfied; |
| 17 |
> i.e. even if all the dependencies are present on the system, the |
| 18 |
> package will build only against the first matching dependency. |
| 19 |
> |
| 20 |
> The way I see it, the ebuild has to cater for the dynamic situation |
| 21 |
> anyway, for example doing something like: |
| 22 |
> |
| 23 |
> src_configure() { |
| 24 |
> use sdl && |
| 25 |
> has_version media-libs/libsdl && |
| 26 |
> vid_conf="--enable sdl" || |
| 27 |
> use svga && |
| 28 |
> has_version media-libs/svgalib && |
| 29 |
> vid_conf="--enable svga" || |
| 30 |
> use opengl && |
| 31 |
> has_version virtual/opengl && |
| 32 |
> vid_conf="--enable opengl" || |
| 33 |
> use ggi && |
| 34 |
> has_version media-libs/libggi && |
| 35 |
> vid_conf="--enable ggi" || |
| 36 |
> vid_conf="--enable x11" |
| 37 |
> ... |
| 38 |
> econf ${vid_conf} ... |
| 39 |
> } |
| 40 |
> |
| 41 |
> So the dependency could be re-written as: |
| 42 |
> |
| 43 |
> sdl? ( media-libs/libsdl ) |
| 44 |
> !sdl? ( svga? ( media-libs/svgalib ) |
| 45 |
> !svga? ( opengl? ( virtual/opengl ) |
| 46 |
> !opengl? ( ggi? ( media-libs/libggi ) |
| 47 |
> !ggi? ( virtual/x ) ) ) ) |
| 48 |
> |
| 49 |
> and you have the same result, which means the originally quoted syntax |
| 50 |
> is redundant. The only advantage it has is that it looks a little bit |
| 51 |
> prettier - but I'd argue the logic is clearer in the re-written version. |
| 52 |
> |
| 53 |
> I guess the question remains, though - should that syntax be in EAPI=0 |
| 54 |
> or not... |
| 55 |
|
| 56 |
It is only really acceptable for buildtime only dependencies as after the |
| 57 |
build phase nothing is actually different. |
| 58 |
|
| 59 |
Paul |
| 60 |
|
| 61 |
-- |
| 62 |
Paul de Vrieze |
| 63 |
Gentoo Developer |
| 64 |
Mail: pauldv@g.o |
| 65 |
Homepage: http://www.devrieze.net |
Archives