Makefile: compile and link each module just once

Several source files need to be compiled and linked when one or more
config options are selected. To allow for easy selection in the
Makefiles yet to avoild multiple compilation (which costs build time)
and especially multiple linking (which causes errors), we use
"COBJS = $(sort COBJS-y)" which eliminates duplicates.

By courtesy of Detlev Zundel who suggested this approach.

Signed-off-by: Wolfgang Denk <wd@denx.de>

diff --git a/common/Makefile b/common/Makefile
index 0fe9c8b42f5afb63b3315de80ce2efc3b5fabb85..d3888d61e8e3f6346e7cf943845dd751f1b9c7bc 100644 (file)
--- a/common/Makefile
+++ b/common/Makefile
@@ -56,7 +56,8 @@ COBJS-y += env_nowhere.o
 
 # command
 COBJS-$(CONFIG_CMD_AMBAPP) += cmd_ambapp.o
-COBJS-$(CONFIG_AUTOSCRIPT)$(CONFIG_CMD_AUTOSCRIPT) += cmd_autoscript.o
+COBJS-$(CONFIG_AUTOSCRIPT) += cmd_autoscript.o
+COBJS-$(CONFIG_CMD_AUTOSCRIPT) += cmd_autoscript.o
 COBJS-$(CONFIG_CMD_BDI) += cmd_bdinfo.o
 COBJS-$(CONFIG_CMD_BEDBUG) += bedbug.o cmd_bedbug.o
 COBJS-$(CONFIG_CMD_BMP) += cmd_bmp.o
@@ -110,7 +111,8 @@ COBJS-$(CONFIG_LOGBUFFER) += cmd_log.o
 COBJS-y += cmd_mac.o
 COBJS-y += cmd_mem.o
 COBJS-$(CONFIG_CMD_MFSL) += cmd_mfsl.o
-COBJS-$(CONFIG_MII)$(CONFIG_CMD_MII) += miiphyutil.o
+COBJS-$(CONFIG_MII) += miiphyutil.o
+COBJS-$(CONFIG_CMD_MII) += miiphyutil.o
 COBJS-$(CONFIG_CMD_MII) += cmd_mii.o
 COBJS-$(CONFIG_CMD_MISC) += cmd_misc.o
 COBJS-$(CONFIG_CMD_MMC) += cmd_mmc.o
@@ -151,8 +153,7 @@ COBJS-$(CONFIG_LYNXKDI) += lynxkdi.o
 COBJS-$(CONFIG_USB_KEYBOARD) += usb_kbd.o
 COBJS-$(CONFIG_DDR_SPD) += ddr_spd.o
 
-COBJS-y        += $(COBJS-yy)
-COBJS  := $(COBJS-y)
+COBJS  := $(sort COBJS-y)
 SRCS   := $(AOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS   := $(addprefix $(obj),$(AOBJS) $(COBJS))
 

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index f41f33d6ee3b12f83d5947804ed998d032fad8ee..7f817dcf220468479d3492e2116e8346ed9e543a 100644 (file)
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -32,8 +32,8 @@ COBJS-y += date.o
 COBJS-$(CONFIG_RTC_DS12887) += ds12887.o
 COBJS-$(CONFIG_RTC_DS1302) += ds1302.o
 COBJS-$(CONFIG_RTC_DS1306) += ds1306.o
-COBJS-$(CONFIG_RTC_DS1307)$(CONFIG_RTC_DS1338) += ds1307.o
-COBJS-y += $(COBJS-yy)
+COBJS-$(CONFIG_RTC_DS1307) += ds1307.o
+COBJS-$(CONFIG_RTC_DS1338) += ds1307.o
 COBJS-$(CONFIG_RTC_DS1337) += ds1337.o
 COBJS-$(CONFIG_RTC_DS1374) += ds1374.o
 COBJS-$(CONFIG_RTC_DS1556) += ds1556.o
@@ -59,7 +59,7 @@ COBJS-$(CONFIG_RTC_RX8025) += rx8025.o
 COBJS-$(CONFIG_RTC_S3C24X0) += s3c24x0_rtc.o
 COBJS-$(CONFIG_RTC_X1205) += x1205.o
 
-COBJS  := $(COBJS-y)
+COBJS  := $(sort COBJS-y)
 SRCS   := $(COBJS:.o=.c)
 OBJS   := $(addprefix $(obj),$(COBJS))
 

diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index b370828caa41564230cdb28dc4ec8b9bcd92a191..adb0a589bafe0172e90a17c7e607d5f8a15c3e89 100644 (file)
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -39,7 +39,7 @@ COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o
 COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
 COBJS-$(CONFIG_USB_TTY) += usbtty.o
 
-COBJS  := $(COBJS-y)
+COBJS  := $(sort COBJS-y)
 SRCS   := $(COBJS:.o=.c)
 OBJS   := $(addprefix $(obj),$(COBJS))