util: declare all host utils source dependencies in build.mk

Instead of hardcoding the common files for host utils in the generic
rules, let's declare them in the build.mk file using the same system as
the Linux kernel build.

if a binary "foo" declared in "host-util-bin" or "build-util-bin" has a
matching "foo-objs" variable, it will be build from all objects declared
in "foo-objs" else it uses directly "foo.o" (single source file).

This is preparatory to add new "build" tools sharing common sources.

note: the dependencies on the utils are a bit less fine-grained as a
result of this change, but given the low number of tools, that should be
acceptable.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=none
TEST=./util/make_all.sh

Change-Id: Ieffce7ca6f5b685ffb7d1f4626b99aff07b61443
Reviewed-on: https://chromium-review.googlesource.com/176174
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>

Makefile.rules

@@ -10,6 +10,8 @@ objs := $(all-y)
 deps := $(objs:%.o=%.o.d)
 build-utils := $(foreach u,$(build-util-bin),$(out)/util/$(u))
 host-utils := $(foreach u,$(host-util-bin),$(out)/util/$(u))
+build-srcs := $(foreach u,$(build-util-bin),$(sort $($(u)-objs:%.o=util/%.c) util/$(u).c))
+host-srcs := $(foreach u,$(host-util-bin),$(sort $($(u)-objs:%.o=util/%.c) util/$(u).c))
 
 # Create output directories if necessary
 _dir_create := $(foreach d,$(dirs),$(shell [ -d $(out)/$(d) ] || \
@@ -37,8 +39,10 @@ cmd_elf = $(LD) $(LDFLAGS) $(objs) -o $@ -T $< -Map $(out)/$*.map
 cmd_exe = $(CC) $(HOST_TEST_LDFLAGS) $(objs) -o $@
 cmd_c_to_o = $(CC) $(CFLAGS) -MMD -MF $@.d -c $< -o $@
 cmd_c_to_build = $(BUILDCC) $(BUILD_CFLAGS) $(BUILD_LDFLAGS) \
-	         -MMD -MF $@.d $< -o $@
-cmd_c_to_host = $(HOSTCC) $(HOST_CFLAGS) -MMD -MF $@.d $(filter %.c, $^) -o $@
+	         $(sort $(foreach c,$($(*F)-objs),util/$(c:%.o=%.c)) $*.c) \
+	         -MMD -MF $@.d -o $@
+cmd_c_to_host = $(HOSTCC) $(HOST_CFLAGS) -MMD -MF $@.d  -o $@ \
+	         $(sort $(foreach c,$($(*F)-objs),util/$(c:%.o=%.c)) $*.c)
 cmd_host_test = ./util/run_host_test $* $(silent)
 cmd_version = ./util/getversion.sh > $@
 cmd_mv_from_tmp = mv $(out)/$*.bin.tmp $(out)/$*.bin
@@ -153,11 +157,10 @@ $(out)/common/version.o: $(out)/ec_version.h
 $(out)/ec_version.h: $(filter-out $(out)/common/version.o,$(objs))
 	$(call quiet,version,VERSION)
 
-$(build-utils): $(out)/%:%.c
+$(build-utils): $(out)/%:$(build-srcs)
 	$(call quiet,c_to_build,BUILDCC)
 
-$(host-utils): $(out)/%:%.c $(foreach u,$(host-util-common),util/$(u).c) \
-			    $(foreach u,$(util-lock-objs),util/lock/$(u).c)
+$(host-utils): $(out)/%:$(host-srcs)
 	$(call quiet,c_to_host,HOSTCC )
 
 $(out)/util/burn_my_ec: $(out)/$(PROJECT).bin

util/build.mk

@@ -7,10 +7,15 @@
 #
 
 host-util-bin=ectool lbplay burn_my_ec
-host-util-common=ectool_keyscan comm-host comm-dev misc_util ec_flash
+
+comm-objs=$(util-lock-objs:%=lock/%) comm-host.o comm-dev.o
 ifeq ($(CONFIG_LPC),y)
-host-util-common+=comm-lpc
+comm-objs+=comm-lpc.o
 else
-host-util-common+=comm-i2c
+comm-objs+=comm-i2c.o
 endif
+ectool-objs=ectool.o ectool_keyscan.o misc_util.o ec_flash.o $(comm-objs)
+lbplay-objs=lbplay.o $(comm-objs)
+burn_my_ec-objs=ec_flash.o $(comm-objs) misc_util.o
+
 build-util-bin=ec_uartd stm32mon iteflash

util/lock/build.mk

@@ -6,4 +6,4 @@
 # Lock library
 #
 
-util-lock-objs=csem ipc_lock gec_lock
+util-lock-objs=csem.o ipc_lock.o gec_lock.o