From 47ffd6c2fc72b46daa9d5d59eedb894fab2b7ee1 Mon Sep 17 00:00:00 2001
From: Wolfgang Denk <wd@denx.de>
Date: Tue, 9 Sep 2008 15:45:18 +0200
Subject: [PATCH] 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>
---
 common/Makefile         | 9 +++++----
 drivers/rtc/Makefile    | 6 +++---
 drivers/serial/Makefile | 2 +-
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/common/Makefile b/common/Makefile
index 0fe9c8b42f5..d3888d61e8e 100644
--- 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 f41f33d6ee3..7f817dcf220 100644
--- 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 b370828caa4..adb0a589baf 100644
--- 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))
 
-- 
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