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Diffstat (limited to 'doc/user/scanners.xml')
-rw-r--r-- | doc/user/scanners.xml | 57 |
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> |