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GLEP updates.

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12 <title>GLEP 22 -- New "keyword" system to incorporate various userlands/kernels/archs</title>
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32 <tr class="field"><th class="field-name">GLEP:</th><td class="field-body">22</td>
33 </tr>
34 <tr class="field"><th class="field-name">Title:</th><td class="field-body">New &quot;keyword&quot; system to incorporate various userlands/kernels/archs</td>
35 </tr>
36 <tr class="field"><th class="field-name">Version:</th><td class="field-body">1.5</td>
37 </tr>
38 <tr class="field"><th class="field-name">Last-Modified:</th><td class="field-body"><a class="reference" href="http://www.gentoo.org/cgi-bin/viewcvs/xml/htdocs/proj/en/glep/glep-0022.txt?cvsroot=gentoo">2004/07/20 18:15:17</a></td>
39 </tr>
40 <tr class="field"><th class="field-name">Author:</th><td class="field-body">Grant Goodyear &lt;g2boojum&#32;&#97;t&#32;gentoo.org&gt;</td>
41 </tr>
42 <tr class="field"><th class="field-name">Status:</th><td class="field-body">Draft</td>
43 </tr>
44 <tr class="field"><th class="field-name">Type:</th><td class="field-body">Standards Track</td>
45 </tr>
46 <tr class="field"><th class="field-name">Content-Type:</th><td class="field-body"><a class="reference" href="glep-0012.html">text/x-rst</a></td>
47 </tr>
48 <tr class="field"><th class="field-name">Created:</th><td class="field-body">6-Mar-2004</td>
49 </tr>
50 <tr class="field"><th class="field-name">Post-History:</th><td class="field-body">6-Mar-2004, 5-Jun-2004, 20-Jul-2004</td>
51 </tr>
52 </tbody>
53 </table>
54 <hr />
55 <div class="contents topic" id="contents">
56 <p class="topic-title first"><a name="contents">Contents</a></p>
57 <ul class="simple">
58 <li><a class="reference" href="#status" id="id14" name="id14">Status</a></li>
59 <li><a class="reference" href="#credits" id="id15" name="id15">Credits</a></li>
60 <li><a class="reference" href="#abstract" id="id16" name="id16">Abstract</a></li>
61 <li><a class="reference" href="#motivation" id="id17" name="id17">Motivation</a></li>
62 <li><a class="reference" href="#specification" id="id18" name="id18">Specification</a><ul>
63 <li><a class="reference" href="#keyword-fragments" id="id19" name="id19">Keyword Fragments</a></li>
64 <li><a class="reference" href="#reasonable-defaults" id="id20" name="id20">Reasonable Defaults</a></li>
65 <li><a class="reference" href="#ebuild-keyword-database" id="id21" name="id21">Ebuild Keyword Database?</a></li>
66 <li><a class="reference" href="#profiles" id="id22" name="id22">Profiles</a></li>
67 </ul>
68 </li>
69 <li><a class="reference" href="#rationale" id="id23" name="id23">Rationale</a></li>
70 <li><a class="reference" href="#implementation" id="id24" name="id24">Implementation</a></li>
71 <li><a class="reference" href="#backwards-compatibility" id="id25" name="id25">Backwards Compatibility</a></li>
72 <li><a class="reference" href="#id1" id="id26" name="id26">References</a></li>
73 <li><a class="reference" href="#copyright" id="id27" name="id27">Copyright</a></li>
74 </ul>
75 </div>
76 <div class="section" id="status">
77 <h1><a class="toc-backref" href="#id14" name="status">Status</a></h1>
78 <p>After withdrawing this GLEP temporarily, a rewritten version has
79 now been resubmitted. This version no longer tries to prevent a
80 keyword explosion, but merely tries to make it manageable.</p>
81 <p>This version was approved on 14-Jun-2004, with the amendment that cascading
82 profiles should be used.</p>
83 </div>
84 <div class="section" id="credits">
85 <h1><a class="toc-backref" href="#id15" name="credits">Credits</a></h1>
86 <p>This GLEP originated from the concerns that Daniel Robbins had with the
87 <em>x86obsd</em> keyword, and his desire to make the KEYWORDS variable more
88 &quot;feature-rich&quot;. Drobbins' original idea was that we should allow compound
89 keywords such as gnu/x86, gnu/ppc, and macos/ppc (which would be explicit
90 versions of the more familiar x86, ppc, and macos keywords). Method noted
91 that userland/arch failed to capture the full range of possibilities (what
92 about a GNU userland on a BSD kernel+libc?), and the issue has languished due
93 to a lack of reasonable solutions. The original version of this GLEP
94 generated quite useful comments which hopefully have been addressed here to
95 make the GLEP much more reasonable.</p>
96 </div>
97 <div class="section" id="abstract">
98 <h1><a class="toc-backref" href="#id16" name="abstract">Abstract</a></h1>
99 <p>As Gentoo branches out to support non-Linux and non-GNU systems (such as Hurd,
100 the *BSDs, or even the soon-to-be-open-sourced Solaris), the potential for an
101 &quot;explosion&quot; of possible keywords becomes rather large, since each new
102 userland/kernel/arch/whatever combination will require a new keyword. This
103 GLEP proposes a simple extension to the current KEYWORDS variable that
104 encompasses the four parameters ARCH, USERLAND, KERNEL, and LIBC, but uses
105 sensible defaults to keep the new system manageable.</p>
106 </div>
107 <div class="section" id="motivation">
108 <h1><a class="toc-backref" href="#id17" name="motivation">Motivation</a></h1>
109 <p>Since the beginning, Gentoo Linux has been conceived as a &quot;metadistribution&quot;
110 that combines remarkable flexibility with sensible defaults and exceptional
111 maintainablilty. The goal of the <a class="reference" href="http://www.gentoo.org/proj/en/gentoo-alt/index.xml">Gentoo-Alt</a> <a class="footnote-reference" href="#id2" id="id3" name="id3">[1]</a> project has been to extend that
112 flexibility to include systems other than GNU/Linux. For example, the author
113 of this GLEP has been working to create a <a class="reference" href="http://www.gentoo.org/proj/en/gentoo-alt/bsd/index.xml">version</a> <a class="footnote-reference" href="#id8" id="id9" name="id9">[3]</a> of Gentoo that uses
114 <a class="reference" href="http://www.openbsd.com">OpenBSD</a> <a class="footnote-reference" href="#id5" id="id6" name="id6">[2]</a> as the underlying kernel, userland, and libc. <a class="reference" href="http://www.openbsd.com">OpenBSD</a> <a class="footnote-reference" href="#id5" id="id7" name="id7">[2]</a> supports a
115 variety of different architectures, so, in principle, we would need a new
116 <em>openbsd-arch</em> keyword for each supported architecture. In fact, the
117 situation is even more complicated, because the <a class="reference" href="http://www.gentoo.org/proj/en/gentoo-alt/index.xml">Gentoo-Alt</a> <a class="footnote-reference" href="#id2" id="id4" name="id4">[1]</a> project would
118 eventually like to support the option of &quot;mixing-and-matching&quot;
119 GNU/*BSD/whatever userlands and libcs irrespective of the underlying kernel.
120 (<a class="reference" href="http://www.debian.org">Debian</a> <a class="footnote-reference" href="#id10" id="id11" name="id11">[4]</a>, for example has a similar BSD <a class="reference" href="http://www.debian.org/ports/netbsd/">project</a> <a class="footnote-reference" href="#id12" id="id13" name="id13">[5]</a>, except that they have
121 replaced the BSD userland with a GNU userland.) The net result is that we
122 need keywords that can specify all possible permutations of arch,
123 userland, kernel and libc. A systematic nomenclature is needed.
124 Fortunately, the author is a Chemist. <em>Grin</em></p>
125 </div>
126 <div class="section" id="specification">
127 <h1><a class="toc-backref" href="#id18" name="specification">Specification</a></h1>
128 <div class="section" id="keyword-fragments">
129 <h2><a class="toc-backref" href="#id19" name="keyword-fragments">Keyword Fragments</a></h2>
130 <p>Each keyword needs to specify, either explicitly or
131 implicitly, the following parameters: ARCH, USERLAND, LIBC, and KERNEL.</p>
132 <blockquote>
133 <dl>
134 <dt>ARCH: </dt>
135 <dd>x86, amd64, cobalt, mips64, arm, hppa, ia64, ppc64, sparc</dd>
136 <dt>USERLAND: </dt>
137 <dd>gnu, bsd</dd>
138 <dt>LIBC: </dt>
139 <dd>glibc, openbsd, freebsd, netbsd, macosx</dd>
140 <dt>KERNEL: </dt>
141 <dd>linux, selinux, openbsd, freebsd, netbsd, macosx</dd>
142 </dl>
143 </blockquote>
144 <p>(The above examples are not meant to be complete. Hurd, for example
145 is not included because I know very little about Hurd.)</p>
146 <p>A fully-specified keyword would look like
147 &quot;ARCH-KERNEL-USERLAND-LIBC&quot;, so, for example,
148 &quot;ppc-fbsd-gnu-glibc&quot; would indicate a Gentoo system corresponding to
149 a ppc architecture running the FreeBSD kernel with a GNU userland and glibc
150 as the system C library.</p>
151 </div>
152 <div class="section" id="reasonable-defaults">
153 <h2><a class="toc-backref" href="#id20" name="reasonable-defaults">Reasonable Defaults</a></h2>
154 <p>To keep this system manageable (and both to reduce typing and maintain
155 backwards compatibility), we need sensible defaults. For backwards
156 compatibility, the Gentoo default is a Linux kernel with a GNU userland
157 and glibc C library. Thus, the current crop of ARCH-based keywords
158 (x86, ppc, etcetera) require no change whatsoever. For the *BSD-based
159 systems the default USERLAND and LIBC would be those normally associated
160 with the corresponding KERNEL, so &quot;x86-obsd&quot; describes an x86 system
161 with an OpenBSD kernel, a BSD userland, and the OpenBSD C library. If
162 either USERLAND or LIBC is specified, and thus not the default, then the
163 entire four-parameter string must be used.</p>
164 </div>
165 <div class="section" id="ebuild-keyword-database">
166 <h2><a class="toc-backref" href="#id21" name="ebuild-keyword-database">Ebuild Keyword Database?</a></h2>
167 <p>One issue that has been raised is that adding a large number of keywords
168 to ebuilds is likely to become cumbersome over the long run. (One could
169 imagine that for a simple <cite>econf &amp;&amp; emake &amp;&amp; einstall</cite> ebuild that the
170 list of keywords could grow to be the lengthiest part of the ebuild.)
171 Instead, perhaps it would make more sense to move each ebuild's keywords
172 out of the ebuild proper into a separate, perhaps online, database.
173 Nothing in this GLEP would be incompatible with such an approach, so
174 any further discussion will be deferred to a possible future GLEP on
175 that topic.</p>
176 </div>
177 <div class="section" id="profiles">
178 <h2><a class="toc-backref" href="#id22" name="profiles">Profiles</a></h2>
179 <p>Along with an explosion of keywords comes a concomitant explosion of potential
180 profiles. Just as in the current system, the profile name would be
181 &quot;FLAVOR-KEYWORD-VERSION&quot; (such as &quot;default-s390-2004.1&quot;). One drawback
182 to having a large number of profiles is that maintainance becomes a
183 significant problem. In fact, one could reasonably argue that the current
184 number of profiles is already too many to be easily maintained. One proposal
185 that has been raised to simplify matters is the idea of stackable, or
186 cascading, profiles, so that only differences between profiles would have to
187 be maintained.</p>
188 </div>
189 </div>
190 <div class="section" id="rationale">
191 <h1><a class="toc-backref" href="#id23" name="rationale">Rationale</a></h1>
192 <p>The proposed new &quot;keywording&quot; system is far from elegant, which is
193 a substantial drawback. On the other hand, it is simple, it requires
194 relatively minor changes, and the changes can be implemented
195 gradually over time.</p>
196 </div>
197 <div class="section" id="implementation">
198 <h1><a class="toc-backref" href="#id24" name="implementation">Implementation</a></h1>
199 <p>Since the new keyword system is backwards-compatible with the current
200 system, &quot;implementation&quot; just means adding new keywords to ebuilds
201 as new systems are supported.</p>
202 </div>
203 <div class="section" id="backwards-compatibility">
204 <h1><a class="toc-backref" href="#id25" name="backwards-compatibility">Backwards Compatibility</a></h1>
205 <p>Backwards compatibility has already been addressed in some detail,
206 with the stated goal being a system that would leave all current
207 ebuilds working exactly as they are now.</p>
208 </div>
209 <div class="section" id="id1">
210 <h1><a class="toc-backref" href="#id26" name="id1">References</a></h1>
211 <table class="footnote" frame="void" id="id2" rules="none">
212 <colgroup><col class="label" /><col /></colgroup>
213 <tbody valign="top">
214 <tr><td class="label"><a name="id2">[1]</a></td><td><em>(<a class="fn-backref" href="#id3">1</a>, <a class="fn-backref" href="#id4">2</a>)</em> <a class="reference" href="http://www.gentoo.org/proj/en/gentoo-alt/index.xml">http://www.gentoo.org/proj/en/gentoo-alt/index.xml</a></td></tr>
215 </tbody>
216 </table>
217 <table class="footnote" frame="void" id="id5" rules="none">
218 <colgroup><col class="label" /><col /></colgroup>
219 <tbody valign="top">
220 <tr><td class="label"><a name="id5">[2]</a></td><td><em>(<a class="fn-backref" href="#id6">1</a>, <a class="fn-backref" href="#id7">2</a>)</em> <a class="reference" href="http://www.openbsd.com">http://www.openbsd.com</a></td></tr>
221 </tbody>
222 </table>
223 <table class="footnote" frame="void" id="id8" rules="none">
224 <colgroup><col class="label" /><col /></colgroup>
225 <tbody valign="top">
226 <tr><td class="label"><a class="fn-backref" href="#id9" name="id8">[3]</a></td><td><a class="reference" href="http://www.gentoo.org/proj/en/gentoo-alt/bsd/index.xml">http://www.gentoo.org/proj/en/gentoo-alt/bsd/index.xml</a></td></tr>
227 </tbody>
228 </table>
229 <table class="footnote" frame="void" id="id10" rules="none">
230 <colgroup><col class="label" /><col /></colgroup>
231 <tbody valign="top">
232 <tr><td class="label"><a class="fn-backref" href="#id11" name="id10">[4]</a></td><td><a class="reference" href="http://www.debian.org">http://www.debian.org</a></td></tr>
233 </tbody>
234 </table>
235 <table class="footnote" frame="void" id="id12" rules="none">
236 <colgroup><col class="label" /><col /></colgroup>
237 <tbody valign="top">
238 <tr><td class="label"><a class="fn-backref" href="#id13" name="id12">[5]</a></td><td><a class="reference" href="http://www.debian.org/ports/netbsd/">http://www.debian.org/ports/netbsd/</a></td></tr>
239 </tbody>
240 </table>
241 </div>
242 <div class="section" id="copyright">
243 <h1><a class="toc-backref" href="#id27" name="copyright">Copyright</a></h1>
244 <p>This document has been placed in the public domain.</p>
245 </div>
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