[PATCH 2/5] Makefile: clear list of default rules

[Jonathan Nieder <jrnieder@gmail.com>]

The git makefile never uses any default implicit rules.  If a
prerequisite for one of the intended rules is missing, a default
rule can be used in its place:

	$ make var.s
	    CC var.s
	$ rm var.c
	$ make var.o
	    as   -o var.o var.s

Avoiding the default rules increases performance and avoids
hard-to-debug behaviour.  Especially, once the scope of the
%.o: %.c pattern rule is restricted, we should not fall back
to the default %.o: %.c pattern rule.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
'make -d' reveals that GNU make still ponders the default rules with
this patch applied, though at least it does not use them any more.  Is
it possible to set something like the make '-r' option from within a
makefile?

 Makefile |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index fa08535..9a5d897 100644
--- a/Makefile
+++ b/Makefile
@@ -1635,6 +1635,8 @@ GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) git.o http.o http-walker.o \
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 
+.SUFFIXES:
+
 %.o: %.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 %.s: %.c GIT-CFLAGS FORCE
-- 
1.6.6.rc2