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On Thu, 22 Feb 2007 19:08:48 +0000 |
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Ciaran McCreesh <ciaranm@×××××××.org> wrote: |
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> The example given in ebuild(5) is: |
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> |
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> || ( |
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> sdl? ( media-libs/libsdl ) |
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> svga? ( media-libs/svgalib ) |
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> opengl? ( virtual/opengl ) |
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> ggi? ( media-libs/libggi ) |
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> virtual/x |
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> ) |
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Took me a while to figure out why anyone would want to write that; the |
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key is that ebuild(5) says only one of the conditions is satisfied; |
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i.e. even if all the dependencies are present on the system, the |
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package will build only against the first matching dependency. |
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|
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The way I see it, the ebuild has to cater for the dynamic situation |
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anyway, for example doing something like: |
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src_configure() { |
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use sdl && |
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has_version media-libs/libsdl && |
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vid_conf="--enable sdl" || |
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use svga && |
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has_version media-libs/svgalib && |
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vid_conf="--enable svga" || |
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use opengl && |
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has_version virtual/opengl && |
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vid_conf="--enable opengl" || |
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use ggi && |
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has_version media-libs/libggi && |
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vid_conf="--enable ggi" || |
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vid_conf="--enable x11" |
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... |
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econf ${vid_conf} ... |
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} |
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|
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So the dependency could be re-written as: |
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|
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sdl? ( media-libs/libsdl ) |
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!sdl? ( svga? ( media-libs/svgalib ) |
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!svga? ( opengl? ( virtual/opengl ) |
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!opengl? ( ggi? ( media-libs/libggi ) |
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!ggi? ( virtual/x ) ) ) ) |
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|
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and you have the same result, which means the originally quoted syntax |
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is redundant. The only advantage it has is that it looks a little bit |
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prettier - but I'd argue the logic is clearer in the re-written version. |
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|
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I guess the question remains, though - should that syntax be in EAPI=0 |
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or not... |
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|
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-- |
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Kevin F. Quinn |
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