- Additional chapter for User Guide (Basic Steps)

13 files changed, 414 insertions, 10 deletions

diff --git a/doc/user/MANIFEST b/doc/user/MANIFEST
index 0994f2b..3f9eda3 100644
--- a/doc/user/MANIFEST
+++ b/doc/user/MANIFEST
@@ -40,6 +40,7 @@ sconf.xml
 separate.xml
 simple.xml
 sourcecode.xml
+start.xml
 tasks.xml
 tools.xml
 troubleshoot.xml
diff --git a/doc/user/depends.in b/doc/user/depends.in
index 88828fe..de5eb42 100644
--- a/doc/user/depends.in
+++ b/doc/user/depends.in
@@ -914,7 +914,7 @@
 
   </section>
 
-  <section>
+  <section id="sect-implicit-dependencies">
   <title>Implicit Dependencies:  The &cv-CPPPATH; Construction Variable</title>
 
     <para>
diff --git a/doc/user/depends.xml b/doc/user/depends.xml
index a5e84d6..c423172 100644
--- a/doc/user/depends.xml
+++ b/doc/user/depends.xml
@@ -903,7 +903,7 @@
 
   </section>
 
-  <section>
+  <section id="sect-implicit-dependencies">
   <title>Implicit Dependencies:  The &cv-CPPPATH; Construction Variable</title>
 
     <para>
diff --git a/doc/user/environments.in b/doc/user/environments.in
index f767676..e74ffac 100644
--- a/doc/user/environments.in
+++ b/doc/user/environments.in
@@ -1095,7 +1095,7 @@ environment, of directory names, suffixes, etc.
 
     </section>
 
-    <section>
+    <section id="sect-clone-environments">
     <title>Making Copies of &ConsEnvs;:  the &Clone; Method</title>
 
       <para>
diff --git a/doc/user/environments.xml b/doc/user/environments.xml
index b2a8505..73d84d3 100644
--- a/doc/user/environments.xml
+++ b/doc/user/environments.xml
@@ -1089,7 +1089,7 @@ environment, of directory names, suffixes, etc.
 
     </section>
 
-    <section>
+    <section id="sect-clone-environments">
     <title>Making Copies of &ConsEnvs;:  the &Clone; Method</title>
 
       <para>
diff --git a/doc/user/hierarchy.in b/doc/user/hierarchy.in
index d70633d..b423465 100644
--- a/doc/user/hierarchy.in
+++ b/doc/user/hierarchy.in
@@ -478,7 +478,7 @@ make no difference to the build.
 
   </section>
 
-  <section>
+  <section id="sect-sharing-environments">
   <title>Sharing Environments (and Other Variables) Between &SConscript; Files</title>
 
     <para>
diff --git a/doc/user/hierarchy.xml b/doc/user/hierarchy.xml
index 2e2941c..baf8065 100644
--- a/doc/user/hierarchy.xml
+++ b/doc/user/hierarchy.xml
@@ -442,7 +442,7 @@ make no difference to the build.
 
   </section>
 
-  <section>
+  <section id="sect-sharing-environments">
   <title>Sharing Environments (and Other Variables) Between &SConscript; Files</title>
 
     <para>
diff --git a/doc/user/main.in b/doc/user/main.in
index 4b0807d..2e3683f 100644
--- a/doc/user/main.in
+++ b/doc/user/main.in
@@ -152,6 +152,11 @@
     &build-install;
   </chapter>
 
+   <chapter id="chap-start">
+     <title>Basic steps and advice</title>
+     &start;
+  </chapter>
+
   <chapter id="chap-simple">
     <title>Simple Builds</title>
     &simple;
diff --git a/doc/user/main.xml b/doc/user/main.xml
index 4b0807d..ccc3208 100644
--- a/doc/user/main.xml
+++ b/doc/user/main.xml
@@ -85,6 +85,7 @@
     <!ENTITY sconf SYSTEM "sconf.xml">
     <!ENTITY separate SYSTEM "separate.xml">
     <!ENTITY simple SYSTEM "simple.xml">
+    <!ENTITY start SYSTEM "start.xml">
     <!ENTITY sourcecode SYSTEM "sourcecode.xml">
     <!ENTITY tasks SYSTEM "tasks.xml">
     <!ENTITY tools SYSTEM "tools.xml">
@@ -152,6 +153,11 @@
     &build-install;
   </chapter>
 
+  <chapter id="chap-start">
+    <title>Basic steps and advice</title>
+    &start;
+  </chapter>
+
   <chapter id="chap-simple">
     <title>Simple Builds</title>
     &simple;
diff --git a/doc/user/simple.in b/doc/user/simple.in
index 8a25be5..373d2b8 100644
--- a/doc/user/simple.in
+++ b/doc/user/simple.in
@@ -297,7 +297,7 @@
 
  </section>
 
- <section>
+ <section id="sect-sconstruct-file">
  <title>The &SConstruct; File</title>
 
    <para>
@@ -353,7 +353,7 @@
 
    </section>
 
-   <section>
+   <section id="sect-order-independent">
    <title>&SCons; Functions Are Order-Independent</title>
 
      <para>
diff --git a/doc/user/simple.xml b/doc/user/simple.xml
index 2a687a0..e24ecbd 100644
--- a/doc/user/simple.xml
+++ b/doc/user/simple.xml
@@ -322,7 +322,7 @@
 
  </section>
 
- <section>
+ <section id="sect-sconstruct-file">
  <title>The &SConstruct; File</title>
 
    <para>
@@ -378,7 +378,7 @@
 
    </section>
 
-   <section>
+   <section id="sect-order-independent">
    <title>&SCons; Functions Are Order-Independent</title>
 
      <para>
diff --git a/doc/user/start.in b/doc/user/start.in
new file mode 100644
index 0000000..3d1693b
--- /dev/null
+++ b/doc/user/start.in
@@ -0,0 +1,196 @@
+<!--
+
+  __COPYRIGHT__
+
+  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>
+
+If you're completely new to a build system like &SCons;, this chapter is written for you.
+We very briefly discuss the general setup of your project, regarding the &SCons; configuration
+files &SConstruct; and &SConscript;.
+Additionally, a few guidelines are provided about how to start a project...hopefully preventing you from
+running into dead-end after dead-end later on.
+
+ </para>
+
+ <section>
+ <title>SCons files</title>
+   <para>
+Okay, so you have a version of your shiny new project, ready for its very first &SCons; build. Or maybe you decided
+to drop make/autotools, and want to try out &SCons; on the cool media-message-mailing library that you already provide
+on Sourceforge (Tigris, Github, Bitbucket, Launchpad...).
+</para>
+<para>
+Let's say you have a source folder in your file system, a directory with all the input files for the build process.
+These may be C or C++ files, TeX/LaTeX sources or a Java package tree. For a start we also assume that you want the
+resulting files, like libs, executables, JARs and PDFs, to be created in the same folder structure. Alongside your
+sources, so to speak.
+</para>
+<para>
+In order to get &SCons; going you have to give it your input files and tell it what to build. Like in most build systems,
+this is done by writing a special text file (or several of them) further describing your build setup. You place this
+file, named &SConstruct; (see <xref linkend="chap-simple"></xref>), at the top of your source folder tree:
+</para>
+<screen>
+yoursrc
+    yourlib1
+        *.cpp/h
+    yourlib2
+        *.cpp/h
+    yourexe
+        *.cpp/h
+    README
+    INSTALL
+    SConstruct
+</screen>
+<para>
+To start a build, you open a terminal (text console, prompt, shell,...whatever it is called in your current system) and
+change into the folder with the &SConstruct; in it. Having &SCons; properly installed (see <xref linkend="chap-build-install"></xref>), you call the command
+</para>
+   <screen>
+      % <userinput>scons</userinput>
+   </screen>
+<para>
+and the processing starts. &SCons; reads your &SConstruct; and starts to build things for you, hopefully.
+</para>
+<para>
+So much for a very quick start and the basics about how to get &SCons; going.
+A discussion of &SCons; at great length can be found in the following
+chapters and sections. Read on please, to learn more about all the available features and possibilities...
+</para>
+
+ </section>
+
+ <section>
+ <title>A few additional guidelines</title>
+
+   <para>
+   With &SCons; and the power of Python as backup, you are pretty much free to do anything
+   you like. However, when you start without any prior experience a few pointers might
+   help as a good foundation for your work. That's exactly what the following list is there
+   for. A few best practices and you can have your pick...or roll your own stuff.
+   </para>
+
+   <itemizedlist>
+
+    <listitem>
+      <para><emphasis>Think in modules</emphasis>: Try to create an &SConscript; for
+        each subfolder, containing one of your libs or executables.
+        Then, call these &SConscript;s from a single &SConstruct; at the top of your
+        build directory.
+      </para>
+      <para>
+        From what our experience tells us, this is the setup that offers you the most flexibility
+        regarding build options and variant dirs. It may look a bit complicated and overdone
+        right now, but starting this way pays off really fast.
+      </para>
+      <para>
+A simple example:
+      </para>
+ <screen>
+yoursrc
+    yourlib1
+        SConscript
+        *.cpp/h
+    yourlib2
+        SConscript
+        *.cpp/h
+    SConstruct
+</screen>
+<para>
+would include the &SConscript;s by
+</para>
+<screen>
+SConscript(['yourlib1/SConscript'])
+SConscript(['yourlib2/SConscript'])
+</screen>
+<para>
+in the &SConstruct;.
+</para>
+<para>Check out <xref linkend="sect-sconstruct-file"></xref> and <xref linkend="chap-hierarchical"></xref> for more infos about this.
+</para>
+   </listitem>
+
+    <listitem>
+      <para><emphasis>Configure at the top and reuse</emphasis>: Configure the environments that you
+        need, in your &SConstruct; file at the very top of your build tree.
+        Don't create them anew in each &SConscript; (module) but export them globally
+        and use Clone() to make a local copy where required.
+      </para>
+      <para>
+        In your &SConstruct; at the top you can create and export a basic Environment as:
+<screen>
+env = Environment(tools=['default'], CC='/opt/arm-gcc_4.01/bin/gcc')
+Export('env')
+</screen>
+        and access it in one of your &SConscript;s by:
+<screen>
+Import('env')
+debug_env = env.Clone()
+debug_env.Append(CCFLAGS=['-g'])
+debug_env.Program('foo','foo.c')
+</screen>
+</para>
+<para>
+Pointers to more info are <xref linkend="chap-environments"></xref>, 
+especially <xref linkend="sect-construction-environments"></xref> and 
+<xref linkend="sect-clone-environments"></xref>, as well as <xref linkend="sect-sharing-environments"></xref>.
+      </para>
+    </listitem>
+    <listitem>
+      <para><emphasis>Think in dependencies</emphasis>: &SCons; works by knowing dependencies. Internally,
+        it builds a large dependency
+        graph (DAG, <emphasis>directed acyclic graph</emphasis>) for all its build tasks. The single
+        files are managed as nodes, while the edges represent the build dependencies.
+        No dependency, no build. It's that simple.
+        Try to forget about those phony targets, that you may have used all throughout <literal>make</literal> (shudder).
+        Check out this User manual, or ask for help on the &SCons; mailing lists. Don't fall back to those
+        bad old habits and hack around, only because you're under time pressure. Try to do your builds the &SCons; way!
+      </para>
+      <para>
+       <xref linkend="chap-depends"></xref>, <xref linkend="sect-implicit-dependencies"></xref>,
+       <xref linkend="chap-builders-writing"></xref>, and <xref linkend="chap-scanners"></xref>
+       will tell you more about how dependencies work in &SCons; and can be bent
+       the way you want them.
+      </para>
+    </listitem>
+    <listitem>
+      <para><emphasis>Don't serialize</emphasis>: Finally, &SCons; is all about handling large projects with complicated builds. It is specially
+        optimized for working in parallel, and schedules all the single build tasks automatically.
+        This means that you can't easily get &SCons; to execute some scripts <literal>A</literal> and <literal>B</literal> in a predefined sequence (cf. <xref linkend="sect-order-independent"></xref>).
+        If you want to define a simple series of build tasks, that have to get executed in a fixed order regardless
+        of dependencies and timestamps, you should consider to use a simple shell or Python script as
+        wrapper instead.
+        Don't hurt your brain, while trying to force &SCons; into doing something that it wasn't designed for in the
+        first place.
+      </para>
+      <para>
+       &SCons; supports building multiple targets in parallel via a <literal>-j</literal> option that
+       takes, as its argument, the number of simultaneous tasks that may be
+       spawned: <quote><literal>scons -j 4</literal></quote> builds four targets
+       in parallel, for example.
+      </para>
+    </listitem>
+   </itemizedlist>
+
+ </section>
diff --git a/doc/user/start.xml b/doc/user/start.xml
new file mode 100644
index 0000000..3d1693b
--- /dev/null
+++ b/doc/user/start.xml
@@ -0,0 +1,196 @@
+<!--
+
+  __COPYRIGHT__
+
+  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>
+
+If you're completely new to a build system like &SCons;, this chapter is written for you.
+We very briefly discuss the general setup of your project, regarding the &SCons; configuration
+files &SConstruct; and &SConscript;.
+Additionally, a few guidelines are provided about how to start a project...hopefully preventing you from
+running into dead-end after dead-end later on.
+
+ </para>
+
+ <section>
+ <title>SCons files</title>
+   <para>
+Okay, so you have a version of your shiny new project, ready for its very first &SCons; build. Or maybe you decided
+to drop make/autotools, and want to try out &SCons; on the cool media-message-mailing library that you already provide
+on Sourceforge (Tigris, Github, Bitbucket, Launchpad...).
+</para>
+<para>
+Let's say you have a source folder in your file system, a directory with all the input files for the build process.
+These may be C or C++ files, TeX/LaTeX sources or a Java package tree. For a start we also assume that you want the
+resulting files, like libs, executables, JARs and PDFs, to be created in the same folder structure. Alongside your
+sources, so to speak.
+</para>
+<para>
+In order to get &SCons; going you have to give it your input files and tell it what to build. Like in most build systems,
+this is done by writing a special text file (or several of them) further describing your build setup. You place this
+file, named &SConstruct; (see <xref linkend="chap-simple"></xref>), at the top of your source folder tree:
+</para>
+<screen>
+yoursrc
+    yourlib1
+        *.cpp/h
+    yourlib2
+        *.cpp/h
+    yourexe
+        *.cpp/h
+    README
+    INSTALL
+    SConstruct
+</screen>
+<para>
+To start a build, you open a terminal (text console, prompt, shell,...whatever it is called in your current system) and
+change into the folder with the &SConstruct; in it. Having &SCons; properly installed (see <xref linkend="chap-build-install"></xref>), you call the command
+</para>
+   <screen>
+      % <userinput>scons</userinput>
+   </screen>
+<para>
+and the processing starts. &SCons; reads your &SConstruct; and starts to build things for you, hopefully.
+</para>
+<para>
+So much for a very quick start and the basics about how to get &SCons; going.
+A discussion of &SCons; at great length can be found in the following
+chapters and sections. Read on please, to learn more about all the available features and possibilities...
+</para>
+
+ </section>
+
+ <section>
+ <title>A few additional guidelines</title>
+
+   <para>
+   With &SCons; and the power of Python as backup, you are pretty much free to do anything
+   you like. However, when you start without any prior experience a few pointers might
+   help as a good foundation for your work. That's exactly what the following list is there
+   for. A few best practices and you can have your pick...or roll your own stuff.
+   </para>
+
+   <itemizedlist>
+
+    <listitem>
+      <para><emphasis>Think in modules</emphasis>: Try to create an &SConscript; for
+        each subfolder, containing one of your libs or executables.
+        Then, call these &SConscript;s from a single &SConstruct; at the top of your
+        build directory.
+      </para>
+      <para>
+        From what our experience tells us, this is the setup that offers you the most flexibility
+        regarding build options and variant dirs. It may look a bit complicated and overdone
+        right now, but starting this way pays off really fast.
+      </para>
+      <para>
+A simple example:
+      </para>
+ <screen>
+yoursrc
+    yourlib1
+        SConscript
+        *.cpp/h
+    yourlib2
+        SConscript
+        *.cpp/h
+    SConstruct
+</screen>
+<para>
+would include the &SConscript;s by
+</para>
+<screen>
+SConscript(['yourlib1/SConscript'])
+SConscript(['yourlib2/SConscript'])
+</screen>
+<para>
+in the &SConstruct;.
+</para>
+<para>Check out <xref linkend="sect-sconstruct-file"></xref> and <xref linkend="chap-hierarchical"></xref> for more infos about this.
+</para>
+   </listitem>
+
+    <listitem>
+      <para><emphasis>Configure at the top and reuse</emphasis>: Configure the environments that you
+        need, in your &SConstruct; file at the very top of your build tree.
+        Don't create them anew in each &SConscript; (module) but export them globally
+        and use Clone() to make a local copy where required.
+      </para>
+      <para>
+        In your &SConstruct; at the top you can create and export a basic Environment as:
+<screen>
+env = Environment(tools=['default'], CC='/opt/arm-gcc_4.01/bin/gcc')
+Export('env')
+</screen>
+        and access it in one of your &SConscript;s by:
+<screen>
+Import('env')
+debug_env = env.Clone()
+debug_env.Append(CCFLAGS=['-g'])
+debug_env.Program('foo','foo.c')
+</screen>
+</para>
+<para>
+Pointers to more info are <xref linkend="chap-environments"></xref>, 
+especially <xref linkend="sect-construction-environments"></xref> and 
+<xref linkend="sect-clone-environments"></xref>, as well as <xref linkend="sect-sharing-environments"></xref>.
+      </para>
+    </listitem>
+    <listitem>
+      <para><emphasis>Think in dependencies</emphasis>: &SCons; works by knowing dependencies. Internally,
+        it builds a large dependency
+        graph (DAG, <emphasis>directed acyclic graph</emphasis>) for all its build tasks. The single
+        files are managed as nodes, while the edges represent the build dependencies.
+        No dependency, no build. It's that simple.
+        Try to forget about those phony targets, that you may have used all throughout <literal>make</literal> (shudder).
+        Check out this User manual, or ask for help on the &SCons; mailing lists. Don't fall back to those
+        bad old habits and hack around, only because you're under time pressure. Try to do your builds the &SCons; way!
+      </para>
+      <para>
+       <xref linkend="chap-depends"></xref>, <xref linkend="sect-implicit-dependencies"></xref>,
+       <xref linkend="chap-builders-writing"></xref>, and <xref linkend="chap-scanners"></xref>
+       will tell you more about how dependencies work in &SCons; and can be bent
+       the way you want them.
+      </para>
+    </listitem>
+    <listitem>
+      <para><emphasis>Don't serialize</emphasis>: Finally, &SCons; is all about handling large projects with complicated builds. It is specially
+        optimized for working in parallel, and schedules all the single build tasks automatically.
+        This means that you can't easily get &SCons; to execute some scripts <literal>A</literal> and <literal>B</literal> in a predefined sequence (cf. <xref linkend="sect-order-independent"></xref>).
+        If you want to define a simple series of build tasks, that have to get executed in a fixed order regardless
+        of dependencies and timestamps, you should consider to use a simple shell or Python script as
+        wrapper instead.
+        Don't hurt your brain, while trying to force &SCons; into doing something that it wasn't designed for in the
+        first place.
+      </para>
+      <para>
+       &SCons; supports building multiple targets in parallel via a <literal>-j</literal> option that
+       takes, as its argument, the number of simultaneous tasks that may be
+       spawned: <quote><literal>scons -j 4</literal></quote> builds four targets
+       in parallel, for example.
+      </para>
+    </listitem>
+   </itemizedlist>
+
+ </section>