bitbake: cookerdata: Add a function to find TOPDIR

Finding the top level build directory is currently hard and relies on
having a complete cooker being setup. Add a helper function which
does the same thing without all the extra overhead. This is needed
to be able to locate the bitbake lockfile and hence the socket
for connecting clients in the new server model.

(Bitbake rev: d196afe68032898c31a8599ca7d3ceba58d96b0a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cookerdata.py

@@ -230,6 +230,27 @@ def findConfigFile(configfile, data):
 
     return None
 
+#
+# We search for a conf/bblayers.conf under an entry in BBPATH or in cwd working 
+# up to /. If that fails, we search for a conf/bitbake.conf in BBPATH.
+#
+
+def findTopdir():
+    d = bb.data.init()
+    bbpath = None
+    if 'BBPATH' in os.environ:
+        bbpath = os.environ['BBPATH']
+        d.setVar('BBPATH', bbpath)
+
+    layerconf = findConfigFile("bblayers.conf", d)
+    if layerconf:
+        return os.path.dirname(os.path.dirname(layerconf))
+    if bbpath:
+        bitbakeconf = bb.utils.which(bbpath, "conf/bitbake.conf")
+        if bitbakeconf:
+            return os.path.dirname(os.path.dirname(bitbakeconf))
+    return None
+
 class CookerDataBuilder(object):
 
     def __init__(self, cookercfg, worker = False):