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<?xml version='1.0'?>
<!DOCTYPE sconsdoc [
<!ENTITY % scons SYSTEM "../scons.mod">
%scons;
]>
<chapter id="chap-preface"
xmlns="http://www.scons.org/dbxsd/v1.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.scons.org/dbxsd/v1.0 http://www.scons.org/dbxsd/v1.0/scons.xsd">
<title>Preface</title>
<!--
Copyright (c) 2001 - 2016 The SCons Foundation
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-->
<para>
This document assumes that you already know how &SCons;
and that you want to learn how to work on the code.
</para>
<section>
<title>&SCons; Principles</title>
<para>
There are a few overriding principles
we try to live up to in designing and implementing &SCons;:
</para>
<variablelist>
<varlistentry>
<term>Correctness</term>
<listitem>
<para>
First and foremost,
by default, &SCons; guarantees a correct build
even if it means sacrificing performance a little.
We strive to guarantee the build is correct
regardless of how the software being built is structured,
how it may have been written,
or how unusual the tools are that build it.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Performance</term>
<listitem>
<para>
Given that the build is correct,
we try to make &SCons; build software
as quickly as possible.
In particular, wherever we may have needed to slow
down the default &SCons; behavior to guarantee a correct build,
we also try to make it easy to speed up &SCons;
through optimization options that let you trade off
guaranteed correctness in all end cases for
a speedier build in the usual cases.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Convenience</term>
<listitem>
<para>
&SCons; tries to do as much for you out of the box as reasonable,
including detecting the right tools on your system
and using them correctly to build the software.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
In a nutshell, we try hard to make &SCons; just
"do the right thing" and build software correctly,
with a minimum of hassles.
</para>
</section>
<section>
<title>Acknowledgements</title>
<para>
&SCons; would not exist without a lot of help
from a lot of people,
many of whom may not even be aware
that they helped or served as inspiration.
So in no particular order,
and at the risk of leaving out someone:
</para>
<para>
First and foremost,
&SCons; owes a tremendous debt to Bob Sidebotham,
the original author of the classic Perl-based &Cons; tool
which Bob first released to the world back around 1996.
Bob's work on Cons classic provided the underlying architecture
and model of specifying a build configuration
using a real scripting language.
My real-world experience working on Cons
informed many of the design decisions in SCons,
including the improved parallel build support,
making Builder objects easily definable by users,
and separating the build engine from the wrapping interface.
</para>
<para>
Greg Wilson was instrumental in getting
&SCons; started as a real project
when he initiated the Software Carpentry design
competition in February 2000.
Without that nudge,
marrying the advantages of the Cons classic
architecture with the readability of Python
might have just stayed no more than a nice idea.
</para>
<para>
Thanks to Peter Miller
for his splendid change management system, &Aegis;,
which has provided the &SCons; project
with a robust development methodology from day one,
and which showed me how you could
integrate incremental regression tests into
a practical development cycle
(years before eXtreme Programming arrived on the scene).
</para>
<para>
And last, thanks to Guido van Rossum
for his elegant scripting language,
which is the basis not only for the &SCons; implementation,
but for the interface itself.
</para>
</section>
</chapter>
|
