--- a/ipc/Makefile.in
+++ b/ipc/Makefile.in
@@ -4,29 +4,9 @@
 
 DEPTH = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-DIRS += chromium glue ipdl testshell
-
-ifdef MOZ_B2G_RIL #{
-DIRS += ril
-endif #}
-
-ifdef MOZ_B2G_BT #{
-DIRS += dbus
-endif #}
-
-ifeq (gonk,$(MOZ_WIDGET_TOOLKIT))
-DIRS += netd unixsocket
-endif
-
-ifeq ($(OS_ARCH),Linux)
-DIRS += unixsocket
-endif
-
-TOOL_DIRS = app
-
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/ipc/app/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/chromium/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/dbus/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/glue/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

--- a/ipc/ipdl/Makefile.in
+++ b/ipc/ipdl/Makefile.in
@@ -46,20 +46,16 @@ IPDLDIRS =  \
   uriloader/prefetch  \
   $(NULL)
 
 ifdef MOZ_IPDL_TESTS #{
 IPDLDIRS += ipc/ipdl/test/cxx
 endif #}
 ##-----------------------------------------------------------------------------
 
-ifdef MOZ_IPDL_TESTS
-DIRS += test
-endif
-
 vpath %.ipdl $(topsrcdir)
 vpath %.ipdlh $(topsrcdir)
 
 define ADD_IPDLDIR
 include $(topsrcdir)/$(IPDLDIR)/ipdl.mk
 ALL_IPDLSRCS += $$(IPDLSRCS:%=$(IPDLDIR)/%)
 PROTOCOLS += $$(IPDLSRCS)
 endef

new file mode 100644
--- /dev/null
+++ b/ipc/ipdl/moz.build
@@ -0,0 +1,7 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+if CONFIG['MOZ_IPDL_TESTS']:
+    DIRS += ['test']

--- a/ipc/ipdl/test/Makefile.in
+++ b/ipc/ipdl/test/Makefile.in
@@ -3,18 +3,9 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DEPTH = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
-
-# we ignore MOZ_IPDL_TESTS for the IPDL-compiler-only tests, since they're
-# quick and painless
-DIRS += ipdl
-
-ifdef MOZ_IPDL_TESTS
-DIRS += cxx
-endif
-
 include $(topsrcdir)/config/rules.mk

--- a/ipc/ipdl/test/cxx/Makefile.in
+++ b/ipc/ipdl/test/cxx/Makefile.in
@@ -4,18 +4,16 @@
 
 DEPTH = @DEPTH@
 topsrcdir = @top_srcdir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
-TOOL_DIRS += app
-
 MODULE = ipdlunittest
 
 EXPORTS_NAMESPACES = mozilla/_ipdltest
 EXPORTS_mozilla/_ipdltest =  \
   IPDLUnitTests.h  \
   IPDLUnitTestProcessChild.h  \
   IPDLUnitTestTypes.h \
   IPDLUnitTestUtils.h \

new file mode 100644
--- /dev/null
+++ b/ipc/ipdl/test/cxx/app/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/ipdl/test/cxx/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+TOOL_DIRS += ['app']

new file mode 100644
--- /dev/null
+++ b/ipc/ipdl/test/ipdl/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/ipdl/test/moz.build
@@ -0,0 +1,11 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# we ignore MOZ_IPDL_TESTS for the IPDL-compiler-only tests, since they're
+# quick and painless
+DIRS += ['ipdl']
+
+if CONFIG['MOZ_IPDL_TESTS']:
+    DIRS += ['cxx']

new file mode 100644
--- /dev/null
+++ b/ipc/moz.build
@@ -0,0 +1,24 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += [
+    'chromium',
+    'glue',
+    'ipdl',
+    'testshell',
+]
+
+if CONFIG['MOZ_B2G_RIL']:
+    DIRS += ['ril']
+
+if CONFIG['MOZ_B2G_BT']:
+    DIRS += ['dbus']
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
+    DIRS += ['netd', 'unixsocket']
+elif CONFIG['OS_ARCH'] == 'Linux':
+    DIRS += ['unixsocket']
+
+TOOL_DIRS += ['app']

new file mode 100644
--- /dev/null
+++ b/ipc/netd/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/ril/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/testshell/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+

new file mode 100644
--- /dev/null
+++ b/ipc/unixsocket/moz.build
@@ -0,0 +1,5 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+