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, 16 insertions, 12 deletions

diff --git a/libbb/Makefile b/libbb/Makefile
index fbcb12330..e94c05260 100644
--- a/libbb/Makefile
+++ b/libbb/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)/libbb
 LIBBB_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/libbb/Makefile.in b/libbb/Makefile.in
index f86664f15..85d4a967b 100644
--- a/libbb/Makefile.in
+++ b/libbb/Makefile.in
@@ -16,12 +16,11 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 
-
-
 LIBBB_AR:=libbb.a
 ifndef $(LIBBB_DIR)
-LIBBB_DIR:=$(TOPDIR)libbb/
+LIBBB_DIR:=$(top_builddir)/libbb/
 endif
+srcdir=$(top_srcdir)/libbb
 
 LIBBB_SRC:= \
 	bb_asprintf.c ask_confirmation.c change_identity.c chomp.c \
@@ -51,7 +50,7 @@ LIBBB_SRC:= \
 
 LIBBB_OBJS=$(patsubst %.c,$(LIBBB_DIR)%.o, $(LIBBB_SRC))
 
-LIBBB_MSRC0:=$(LIBBB_DIR)messages.c
+LIBBB_MSRC0:=$(srcdir)/messages.c
 LIBBB_MOBJ0:=full_version.o \
 	memory_exhausted.o invalid_date.o io_error.o \
 	write_error.o name_longer_than_foo.o unknown.o \
@@ -60,19 +59,19 @@ LIBBB_MOBJ0:=full_version.o \
 	securetty_file.o motd_file.o \
 	msg_standard_input.o msg_standard_output.o shell_file.o
 
-LIBBB_MSRC1:=$(LIBBB_DIR)xfuncs.c
+LIBBB_MSRC1:=$(srcdir)/xfuncs.c
 LIBBB_MOBJ1:=xmalloc.o xrealloc.o xcalloc.o xstrdup.o xstrndup.o \
 	xfopen.o xopen.o xread.o xread_all.o xread_char.o \
 	xferror.o xferror_stdout.o xfflush_stdout.o strlen.o
 
-LIBBB_MSRC2:=$(LIBBB_DIR)printf.c
+LIBBB_MSRC2:=$(srcdir)/printf.c
 LIBBB_MOBJ2:=bb_vfprintf.o bb_vprintf.o bb_fprintf.o bb_printf.o
 
-LIBBB_MSRC3:=$(LIBBB_DIR)xgetularg.c
+LIBBB_MSRC3:=$(srcdir)/xgetularg.c
 LIBBB_MOBJ3:=xgetularg_bnd_sfx.o xgetlarg_bnd_sfx.o getlarg10_sfx.o \
 	xgetularg_bnd.o xgetularg10_bnd.o xgetularg10.o
 
-LIBBB_MSRC4:=$(LIBBB_DIR)/safe_strtol.c
+LIBBB_MSRC4:=$(srcdir)/safe_strtol.c
 LIBBB_MOBJ4:=safe_strtoi.o safe_strtod.o safe_strtol.o safe_strtoul.o
 
 LIBBB_MOBJS0=$(patsubst %,$(LIBBB_DIR)%, $(LIBBB_MOBJ0))
@@ -88,6 +87,9 @@ $(LIBBB_DIR)$(LIBBB_AR): $(LIBBB_OBJS) $(LIBBB_MOBJS0) $(LIBBB_MOBJS1) \
 	$(AR) -ro $@ $(LIBBB_OBJS) $(LIBBB_MOBJS0) $(LIBBB_MOBJS1) \
 		$(LIBBB_MOBJS2) $(LIBBB_MOBJS3) $(LIBBB_MOBJS4)
 
+$(LIBBB_DIR)%.o: $(srcdir)/%.c
+	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+
 $(LIBBB_MOBJS0): $(LIBBB_MSRC0)
 	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -DL_$(notdir $*) -c $< -o $@