egor duda writes:

Hi!

I've created a patch to busybox' build system to allow building it in
separate tree in a manner similar to kbuild from kernel version 2.6.

That is, one runs command like
'make O=/build/some/where/for/specific/target/and/options'
and everything is built in this exact directory, provided that it exists.

I understand that applyingc such invasive changes during 'release
candidates' stage of development is at best unwise. So, i'm currently
asking for comments about this patch, starting from whether such thing
is needed at all to whether it coded properly.

'make check' should work now, and one make creates Makefile in build
directory, so one can run 'make' in build directory after that.

One possible caveat is that if we build in some directory other than
source one, the source directory should be 'distclean'ed first.

egor

6 files changed, 31 insertions, 17 deletions

diff --git a/networking/Makefile b/networking/Makefile
index 456c433fd..91726b1b2 100644
--- a/networking/Makefile
+++ b/networking/Makefile
@@ -17,13 +17,15 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 #
 
-TOPDIR:= ../
+top_srcdir=..
+top_builddir=..
+srcdir=$(top_srcdir)/networking
 NETWORKING_DIR:=./
-include $(TOPDIR).config
-include $(TOPDIR)Rules.mak
+include $(top_builddir)/Rules.mak
+include $(top_builddir)/.config
 include Makefile.in
 all: $(libraries-y)
--include $(TOPDIR).depend
+-include $(top_builddir)/.depend
 
 clean:
 	rm -f *.o *.a $(AR_TARGET)
diff --git a/networking/Makefile.in b/networking/Makefile.in
index e15e61a3e..9bfe90176 100644
--- a/networking/Makefile.in
+++ b/networking/Makefile.in
@@ -19,9 +19,9 @@
 
 NETWORKING_AR:=networking.a
 ifndef $(NETWORKING_DIR)
-NETWORKING_DIR:=$(TOPDIR)networking/
+NETWORKING_DIR:=$(top_builddir)/networking/
 endif
-
+srcdir=$(top_srcdir)/networking
 NETWORKING-y:=
 NETWORKING-$(CONFIG_ARPING)	+= arping.o
 NETWORKING-$(CONFIG_FTPGET)	+= ftpgetput.o
@@ -63,3 +63,6 @@ endif
 $(NETWORKING_DIR)$(NETWORKING_AR): $(patsubst %,$(NETWORKING_DIR)%, $(NETWORKING-y))
 	$(AR) -ro $@ $(patsubst %,$(NETWORKING_DIR)%, $(NETWORKING-y))
 
+$(NETWORKING_DIR)%.o: $(srcdir)/%.c
+	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+
diff --git a/networking/libiproute/Makefile b/networking/libiproute/Makefile
index 0dc7191d3..d3aefaaf4 100644
--- a/networking/libiproute/Makefile
+++ b/networking/libiproute/Makefile
@@ -17,13 +17,15 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 #
 
-TOPDIR:= ../../
+top_srcdir=../..
+top_builddir=../..
+srcdir=$(top_srcdir)/networking/libiproute
 LIBIPROUTE_DIR:=./
-include $(TOPDIR).config
-include $(TOPDIR)Rules.mak
+include $(top_builddir)/Rules.mak
+include $(top_builddir)/.config
 include Makefile.in
 all: $(libraries-y)
--include $(TOPDIR).depend
+-include $(top_builddir)/.depend
 
 clean:
 	rm -f *.o *.a $(AR_TARGET)
diff --git a/networking/libiproute/Makefile.in b/networking/libiproute/Makefile.in
index 25c51999f..fcc7f48ce 100644
--- a/networking/libiproute/Makefile.in
+++ b/networking/libiproute/Makefile.in
@@ -19,8 +19,9 @@
 
 LIBIPROUTE_AR:=libiproute.a
 ifndef $(LIBIPROUTE_DIR)
-LIBIPROUTE_DIR:=$(TOPDIR)networking/libiproute/
+LIBIPROUTE_DIR:=$(top_builddir)/networking/libiproute/
 endif
+srcdir=$(top_srcdir)/networking/libiproute
 
 LIBIPROUTE-$(CONFIG_IP) += \
 	ip_parse_common_args.o \
@@ -78,3 +79,6 @@ libraries-y+=$(LIBIPROUTE_DIR)$(LIBIPROUTE_AR)
 $(LIBIPROUTE_DIR)$(LIBIPROUTE_AR): $(patsubst %,$(LIBIPROUTE_DIR)%, $(LIBIPROUTE-y))
 	$(AR) -ro $@ $(patsubst %,$(LIBIPROUTE_DIR)%, $(LIBIPROUTE-y))
 
+$(LIBIPROUTE_DIR)%.o: $(srcdir)/%.c
+	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+
diff --git a/networking/udhcp/Makefile b/networking/udhcp/Makefile
index 2b79d2293..3d32db50a 100644
--- a/networking/udhcp/Makefile
+++ b/networking/udhcp/Makefile
@@ -17,13 +17,15 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 #
 
-TOPDIR:= ../../
+top_srcdir=../..
+top_builddir=../..
+srcdir=$(top_srcdir)/networking/udhcp
 UDHCP_DIR:=./
-include $(TOPDIR).config
-include $(TOPDIR)Rules.mak
+include $(top_builddir)/Rules.mak
+include $(top_builddir)/.config
 include Makefile.in
 all: $(libraries-y)
--include $(TOPDIR).depend
+-include $(top_builddir)/.depend
 
 clean:
 	rm -f *.o *.a $(AR_TARGET)
diff --git a/networking/udhcp/Makefile.in b/networking/udhcp/Makefile.in
index b48079429..2d7a08816 100644
--- a/networking/udhcp/Makefile.in
+++ b/networking/udhcp/Makefile.in
@@ -19,8 +19,9 @@
 
 UDHCP_AR:=udhcp.a
 ifndef $(UDHCP_DIR)
-UDHCP_DIR:=$(TOPDIR)networking/udhcp/
+UDHCP_DIR:=$(top_builddir)/networking/udhcp/
 endif
+srcdir=$(top_srcdir)/networking/udhcp
 
 #ok, so I forgot how to do an or, but this is a quick and dirty hack
 ifeq ($(CONFIG_UDHCPC), y)
@@ -48,6 +49,6 @@ libraries-y+=$(UDHCP_DIR)$(UDHCP_AR)
 $(UDHCP_DIR)$(UDHCP_AR): $(UDHCP_OBJS)
 	$(AR) -ro $@ $(UDHCP_OBJS)
 
-$(UDHCP_OBJS): %.o : %.c
+$(UDHCP_OBJS): $(UDHCP_DIR)%.o : $(srcdir)/%.c
 	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -DIN_BUSYBOX -c $< -o $@