Dealing with build attributes of targets

Consider :ltlib (my favorite target type). An AAP command of this form looks 
like:

:ltlib { attributes for ltlib, like installvar } target { attributes for the 
target, like installdir } : { attributes XXX } sources { attributes for each 
source individually }

What should attributes at the location XXX mean? The AAP code picks them out 
specially (they have name=':' and are found at colonidx) into build_attr, and 
later applies them to the target with

    add_buildrule(rpstack, work, recdict,
                type, cmd_attr, targetlist, build_attr,sourcelist)

I don't know exactly what buildrule() does, but this seems to be redundant .. 
is there anything that you would want to put at XXX that can't be done with 
the { attributes for the target } already? If there is, then @raise 
UserError, "Adriaan is a Doofus".

If not, I'd like to change the meaning of the attributes at XXX to mean 
(perhaps in addition) that they apply to all the sources, so that 

:ltlib { installvar = } conduit_time.la
        { var_LDFLAGS = -L/opt/tmp -R/opt/tmp } :
        { add_INCLUDE = -I$BDIR/timeconduit }
        timeconduit/time-factory.cc
        timeconduit/time-setup.cc
        timeconduit/time-conduit.cc
        timeconduit/time-setup_dialog.ui

does exactly what _I_ want.

Patch attached. Yes, I know that both this and the previous bdir() patch need 
documentation. I'd like to know if there is a Whelk's Chance in a Supernova 
of this going in, first, before I write the docs :)

Index: Commands.py
===================================================================
RCS file: /cvsroot/a-a-p/Exec/Commands.py,v
retrieving revision 1.110
diff -u -3 -p -r1.110 Commands.py
--- Commands.py	18 Oct 2003 15:10:41 -0000	1.110
+++ Commands.py	21 Oct 2003 17:07:13 -0000
@@ -328,7 +328,7 @@ def aap_program(line_nr, recdict, arg, t
     if len(targetlist) != 1:
         recipe_error(rpstack, _(":%s requires one target") % cmdname)
 
-    # get any build attributes {attr = value}.
+    # get any build attributes {attr = value} from after the ':'.
     build_attr = dictlist[colonidx]
 
     # Expand the sources into dictlists.
@@ -337,6 +337,11 @@ def aap_program(line_nr, recdict, arg, t
     if len(sourcelist) < 1:
         recipe_error(rpstack, _(":%s requires at least one source") % cmdname)
 
+    # Apply the build attributes to the sources.
+    for i in sourcelist:
+        node = work.get_node(i["name"], 1, i)
+        node.set_attributes(build_attr)
+	
     # ":produce abc" needs to declare "abc" as a filetype.
     if cmdname == "produce":
         ft_declare(type)