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

2 files changed, 12 insertions, 6 deletions

diff --git a/init/Makefile b/init/Makefile
index d23532735..9b0a1d139 100644
--- a/init/Makefile
+++ b/init/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)/init
 INIT_DIR:=./
-include $(TOPDIR).config
-include $(TOPDIR)Rules.mak
-include Makefile.in
+include $(top_builddir)/Rules.mak
+include $(top_builddir)/.config
+include $(srcdir)/Makefile.in
 all: $(libraries-y)
--include $(TOPDIR).depend
+-include $(top_builddir)/.depend
 
 clean:
         rm -f *.o *.a $(AR_TARGET)
diff --git a/init/Makefile.in b/init/Makefile.in
index 6264710db..807259dee 100644
--- a/init/Makefile.in
+++ b/init/Makefile.in
@@ -19,8 +19,9 @@
 
 INIT_AR:=init.a
 ifndef $(INIT_DIR)
-INIT_DIR:=$(TOPDIR)init/
+INIT_DIR:=$(top_builddir)/init/
 endif
+srcdir=$(top_srcdir)/init
 
 INIT-y:=
 INIT-$(CONFIG_HALT)                     += halt.o
@@ -56,3 +57,6 @@ libraries-y+=$(INIT_DIR)$(INIT_AR)
 $(INIT_DIR)$(INIT_AR): $(patsubst %,$(INIT_DIR)%, $(INIT-y))
         $(AR) -ro $@ $(patsubst %,$(INIT_DIR)%, $(INIT-y))
 
+$(INIT_DIR)%.o: $(srcdir)/%.c
+        $(CC) $(CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+