Gentoo Archives: gentoo-portage-dev

From: Jason Stubbs <jasonbstubbs@×××××××××××.com>
To: gentoo-portage-dev@g.o
Subject: [gentoo-portage-dev] The purpose of USE flags
Date: Fri, 12 Dec 2003 13:27:14
1 Hello all,
3 At the risk of sounding precocious, I think I'm going to open another can of
4 worms. ;-)
6 I've been thinking on the idea of USE flags and am wondering what the
7 developers' perspective is. They are defined in "Gentoo Guide to USE flags"
8 as "keywords that define options used on a system-wide basis to configure
9 applications during their respective compilation procedures". Is there any
10 other, more formal, definition?
12 My reason for asking is that my feel, from the way developers and experience
13 users talk about USE flags, that their usage has been mostly restricted to
14 options provided by configure scripts. This is natural as (I assume) that's
15 the way that USE flags evolved. However, I think that the the purpose of USE
16 flags needs to be rethought, when implemented in portage-ng, to include how
17 USE flags pertain to the system as a whole.
19 I was half thinking about it when I wrote the following except from my last
20 mail:
22 On Tuesday 09 December 2003 07:06, Jason Stubbs wrote:
23 > USE flags need to be able to be grouped into 'super-USE' flags. For example:
24 > "multimedia", "workstation", "server", etc.
25 > where "multimedia" = "video-codecs", "audio-codecs", "media-recording", etc.
26 > where "video-codecs" = "avi", "divx", "dvd", etc.
28 I'm going to expand on this idea a little, although I think it might not be
29 well received due to the unexplained fear of USE flag explosion. My idea is
30 that USE flags should be somewhat the equivalent of Microsoft Windows
31 Installer's Product Feature selection tree, the main difference being that it
32 applies to the whole operating system.
34 To explain further, I will again use an example possibility:
35 Multimedia
36 + Recording
37 - Playback
38 + Video
39 - Audio
40 + Audio Codecs
41 - Audio Providers
42 - OSS
43 - ALSA
44 - ARTS
45 - ESD
46 - <default>
48 From this small excerpt of a possible tree, you can image how big a full tree
49 would be. The benefits of this style of tree are manyfold, but I'll just go
50 over a few of the obvious (to me):
52 * Finer grain of control
54 Depending on what is actually implement of course, this model can offer much
55 more control. If the above example is extended to include ALSA drivers, the
56 model is shown to become a unified way to model all option behaviour of
57 packages. Mozilla, for example, could be done in exactly the same way.
59 * Better categorization
61 With this USE flag model, if an ebuild-ng specifies what functionality it
62 provides, both intrisically and optionally, packages become very easy to find
63 for the end-user. It will also be easy to find other packages that do same
64 things as a package that the user is familiar with.
66 That's all that I can think of at the moment. The only negative thing I can
67 see is the explosion of USE flags. However, this is only a bad thing if they
68 are uncategoriezed. Proper categorization should actually make them easier to
69 understand and easier to maintain.
71 Well, that's enough said for now. All constructive criticism and any additions
72 welcome.
74 --
75 Regards,
76 Jason Stubbs
78 --
79 gentoo-portage-dev@g.o mailing list


Subject Author
Re: [gentoo-portage-dev] The purpose of USE flags "Sami Näätänen" <××××××××.com>
Re: [gentoo-portage-dev] The purpose of USE flags Jason Stubbs <jasonbstubbs@×××××××××××.com>