Modify Makefile to allow insertion of mock modules

When we need to mock modules in a unit test, we need a way to mock
the actual modules. This CL enables mock of given source files.
For example, if we need to mock watchdog for test 'foo', we can add to
test/build.mk: "core-mock-foo-watchdog.o=fake_watchdog.o", and then
implement its own watchdog in fake_watchdog.c.

Signed-off-by: Vic Yang <victoryang@chromium.org>

BUG=chrome-os-partner:10356
TEST=Set a mock fake_watchdog.c and check the test is compiled with
     fake_watchdog.c instead of watchdog.c.

Change-Id: I4a0afb589a49dad7c4d6faf8926438085cdc46cf
Reviewed-on: https://gerrit.chromium.org/gerrit/24942
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Ready: Vic Yang <victoryang@chromium.org>
Tested-by: Vic Yang <victoryang@chromium.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/Makefile b/Makefile
index ee86da1881..80566276e2 100644
--- a/Makefile
+++ b/Makefile
@@ -40,16 +40,17 @@ include util/build.mk
 
 includes+=$(includes-y)
 
-objs_from_dir=$(foreach obj,$(2), $(out)/$(1)/$(obj))
+objs_from_dir=$(foreach obj, $($(2)-y), \
+	        $(out)/$(1)/$(firstword $($(2)-mock-$(PROJECT)-$(obj)) $(obj)))
 
 # Get all sources to build
-all-y=$(call objs_from_dir,core/$(CORE),$(core-y))
-all-y+=$(call objs_from_dir,chip/$(CHIP),$(chip-y))
-all-y+=$(call objs_from_dir,board/$(BOARD),$(board-y))
-all-y+=$(call objs_from_dir,private,$(private-y))
-all-y+=$(call objs_from_dir,common,$(common-y))
-all-y+=$(call objs_from_dir,test,$($(PROJECT)-y))
-all-y+=$(call objs_from_dir,vboot,$(vboot-y))
+all-y=$(call objs_from_dir,core/$(CORE),core)
+all-y+=$(call objs_from_dir,chip/$(CHIP),chip)
+all-y+=$(call objs_from_dir,board/$(BOARD),board)
+all-y+=$(call objs_from_dir,private,private)
+all-y+=$(call objs_from_dir,common,common)
+all-y+=$(call objs_from_dir,test,$(PROJECT))
+all-y+=$(call objs_from_dir,vboot,vboot)
 dirs=core/$(CORE) chip/$(CHIP) board/$(BOARD) private common test util
 
 include Makefile.rules