summaryrefslogtreecommitdiff
path: root/doc/user/scanners.xml
diff options
context:
space:
mode:
Diffstat (limited to 'doc/user/scanners.xml')
-rw-r--r--doc/user/scanners.xml57
1 files changed, 55 insertions, 2 deletions
diff --git a/doc/user/scanners.xml b/doc/user/scanners.xml
index 9e3ce99..e1b2249 100644
--- a/doc/user/scanners.xml
+++ b/doc/user/scanners.xml
@@ -21,7 +21,7 @@
<!--
- Copyright (c) 2001 - 2017 The SCons Foundation
+ Copyright (c) 2001 - 2019 The SCons Foundation
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
@@ -410,6 +410,59 @@ kscan = Scanner(function = kfile_scan,
This is important since many files get scanned in a typical build.
</para>
- </section>
+ </section>
+
+ <section>
+ <title>Using scanners with Builders</title>
+
+ <para>
+
+ One approach for the use of scanners is with builders.
+ There are two optional parameters we can use with a builder
+ <literal>source_scanner</literal> and <literal>target_scanner</literal>.
+
+ </para>
+
+ <scons_example name="scanners_builders">
+ <file name="SConstruct" printme="1">
+
+def kfile_scan(node, env, path, arg):
+ contents = node.get_text_contents()
+ return env.File(include_re.findall(contents))
+
+kscan = Scanner(function = kfile_scan,
+ skeys = ['.k'],
+ path_function = FindPathDirs('KPATH'))
+
+def build_function(target, source, env):
+ # Code to build "target" from "source"
+ return None
+
+bld = Builder(action = build_function,
+ suffix = '.foo',
+ source_scanner = kscan
+ src_suffix = '.input')
+env = Environment(BUILDERS = {'Foo' : bld})
+env.Foo('file')
+
+ </file>
+ </scons_example>
+
+ <para>
+
+ An emitter function can modify the list of sources or targets
+ passed to the action function when the builder is triggered.
+
+ </para>
+
+ <para>
+
+ A scanner function will not affect the list of sources or targets
+ seen by the builder during the build action. The scanner function
+ will however affect if the builder should be rebuilt (if any of
+ the files sourced by the scanner have changed for example).
+
+ </para>
+ </section>
</chapter>