3 <!ENTITY % scons SYSTEM "../scons.mod">
7 <chapter id="chap-intro"
8 xmlns="http://www.scons.org/dbxsd/v1.0"
9 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
10 xsi:schemaLocation="http://www.scons.org/dbxsd/v1.0 http://www.scons.org/dbxsd/v1.0/scons.xsd">
11 <title>Introduction</title>
17 Permission is hereby granted, free of charge, to any person obtaining
18 a copy of this software and associated documentation files (the
19 "Software"), to deal in the Software without restriction, including
20 without limitation the rights to use, copy, modify, merge, publish,
21 distribute, sublicense, and/or sell copies of the Software, and to
22 permit persons to whom the Software is furnished to do so, subject to
23 the following conditions:
25 The above copyright notice and this permission notice shall be included
26 in all copies or substantial portions of the Software.
28 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
29 KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
30 WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
32 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
33 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
34 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 The &SCons; tool provides an easy-to-use, feature-rich interface
41 for constructing software. Architecturally, &SCons; separates
42 its dependency analysis and external object management into an
43 interface-independent Build Engine that could be embedded in any
44 software system that can run Python.
50 At the command line, &SCons; presents an easily-grasped tool
51 where configuration files are Python scripts, reducing the need
52 to learn new build-tool syntax. Inexperienced users can use
53 intelligent methods that ``do the right thing'' to build software
54 with a minimum of fuss. Sophisticated users can use a rich set
55 of underlying features for finer control of the build process,
56 including mechanisms for easily extending the build process to new
63 Dependencies are tracked using digital signatures,
64 which provide more robust dependency analysis than file time
65 stamps. Implicit dependencies are determined automatically by
66 scanning the contents of source files, avoiding the need for
67 laborious and fragile maintenance of static lists of dependencies in
74 The &SCons; tool supports use of files from one or more central code
75 repositories, a mechanism for caching derived files, and parallel
76 builds. The tool also includes a framework for sharing build
77 environments, which allows system administrators or integrators to
78 define appropriate build parameters for use by other users.
82 <section id="sect-document">
83 <title>About This Document</title>
87 This document is an ongoing work-in-progress to write down the ideas
88 and tradeoffs that have gone, and will go into, the &SCons; design.
89 As such, this is intended primarily for use by developers and others
90 working on &SCons;, although it is also intended to serve as a
91 detailed overview of &SCons; for other interested parties. It will
92 be continually updated and evolve, and will likely overlap with other
93 documentation produced by the project. Sections of this document
94 that deal with syntax, for example, may move or be copied into a user
95 guide or reference manual.
101 So please don't assume that everything mentioned here has been
102 decided and carved in stone. If you have ideas for improvements, or
103 questions about things that don't seem to make any sense, please help
104 improve the design by speaking up about them.
109 Sections marked like this
110 (prefixed with <literal>RATIONALE:</literal> in the HTML,
111 surrounded by <literal>BEGIN RATIONALE:</literal>
112 and <literal>END RATIONALE:</literal>
113 in the printed documentatio)
115 comments about the document
116 rather than actual document.
117 I've used these to mark sections that need work,
118 but also to cite some open design issues.
119 If you have input on any of these marked issues,
120 I'm especially eager to hear it.