SCons: implement logic to find source trees, which than can be built as plugin

admin/scons/Buildhelper.py

@@ -91,6 +91,38 @@ def globRootdirs(roots):
 
 
 
+def findSrcTrees(location, patterns=SRCPATTERNS):
+    """ find possible source tree roots, starting with the given location.
+        When delving down from the initial location(s), a source tree is defined
+        as a directory containing source files and possibly further sub directories.
+        After having initially expanded the given location with #globRootdirs, each
+        directory is examined depth first, until encountering a directory containing
+        source files, which then yields a result. Especially, this can be used to traverse
+        an organisational directory structure and find out all possible source trees of
+        to be built into packages, plugins, individual tool executables etc.
+        @return: the relative path names of all source root dirs found (generator function).
+    """
+    for dir in globRootdirs(location):
+        if isSrcDir(dir,patterns):
+            yield dir
+        else:
+            for result in findSrcTrees(str(dir)+'/*'):
+                yield result
+
+
+def isSrcDir(path, patterns=SRCPATTERNS):
+    """ helper: investigate the given (relative) path
+        @param patterns: list of wildcards defining what counts as "source file" 
+        @return: True if it's a directory containing any source file
+    """
+    if not os.path.isdir(path):
+         return False
+    else:
+        for p in patterns:
+            if glob.glob(path+'/'+p):
+                return True
+
+
 
 def filterNodes(nlist, removeName=None):
     """ filter out scons build nodes using the given criteria.
@@ -115,6 +147,19 @@ def getDirname(dir):
 
 
 
+def createPlugins(env, dir):
+    """ investigate the given source directory to identify all contained source trees.
+        @return: a list of build nodes defining a plugin for each of these source trees.
+    """
+    return [env.LoadableModule( '$PLUGDIR/%s' % getDirname(tree) 
+                              , srcSubtree(env, tree)
+                              , SHLIBPREFIX='', SHLIBSUFFIX='.lum'
+                              )
+            for tree in findSrcTrees(dir)
+           ]
+
+
+
 def checkCommandOption(env, optID, val=None, cmdName=None):
     """ evaluate and verify an option, which may point at a command.
         besides specifying a path, the option may read True, yes or 1,