bitbake/ast: Add optional argument for BBCLASSEXTEND

Add an optional argument to BBCLASSEXTEND entries which gets passed to
the extention class as BBEXTENDVARIANT. Also add BBEXTENDCURR whic
is set to the current extension class name.

This mode functions slightly differently to the previous BBCLASSEXTEND
code in that PN is not changed.

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

1 files changed, 21 insertions, 3 deletions

diff --git a/lib/bb/parse/ast.py b/lib/bb/parse/ast.py
index bf70ad265..e41bb74f4 100644
--- a/lib/bb/parse/ast.py
+++ b/lib/bb/parse/ast.py
@@ -427,13 +427,31 @@ def multi_finalize(fn, d):
 
     extended = d.getVar("BBCLASSEXTEND", True) or ""
     if extended:
+        # the following is to support bbextends with argument, for e.g. multilib
+        # an example is as follow:
+        #   BBCLASSEXTEND = "multilib:lib32"
+        # it will create foo-lib32, inheriting multilib.bbclass and set
+        # CURRENTEXTEND to "lib32"
+        extendedmap = {}
+
+        for ext in extended.split():
+            eext = ext.split(':')
+            if len(eext) > 1:
+                extendedmap[eext[1]] = eext[0]
+            else:
+                extendedmap[ext] = ext
+
         pn = d.getVar("PN", True)
         def extendfunc(name, d):
-            d.setVar("PN", "%s-%s" % (pn, name))
-            bb.parse.BBHandler.inherit([name], d)
+            if name != extendedmap[name]:
+                d.setVar("BBEXTENDCURR", extendedmap[name])
+                d.setVar("BBEXTENDVARIANT", name)
+            else:
+                d.setVar("PN", "%s-%s" % (pn, name))
+            bb.parse.BBHandler.inherit([extendedmap[name]], d)
 
         safe_d.setVar("BBCLASSEXTEND", extended)
-        _create_variants(datastores, extended.split(), extendfunc)
+        _create_variants(datastores, extendedmap.keys(), extendfunc)
 
     for variant, variant_d in datastores.iteritems():
         if variant: