[PATCH 03/13] tools lib traceevent: Make dependency files regeneratable

[Arnaldo Carvalho de Melo]

From: Namhyung Kim <namhyung.kim@xxxxxxx>

Ingo reported that libtraceevent doesn't clean out dependency (.d) files
and it can cause a build error when the libgcc package upgraded:

 comet:~/tip/tools/perf> make -j
     SUBDIR ../lib/traceevent/
 make[1]: *** No rule to make target `/usr/lib/gcc/x86_64-redhat-linux/4.7.0/include/stddef.h',
  needed by `event-parse.o'.  Stop.
 make: *** [../lib/traceevent//libtraceevent.a] Error 2

So this patch makes the .d files depends on the source and header files
also, so that it can be re-generated as needed.

NOTE: This code is copied from the GNU make manual page
(4.14 Generating Prerequisites Automatically).

Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1340343462-15556-3-git-send-email-namhyung@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/lib/traceevent/Makefile |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile
index 34a577e..46c2f6b 100644
--- a/tools/lib/traceevent/Makefile
+++ b/tools/lib/traceevent/Makefile
@@ -250,8 +250,12 @@ endef
 all_objs := $(sort $(ALL_OBJS))
 all_deps := $(all_objs:%.o=.%.d)
 
+# let .d file also depends on the source and header files
 define check_deps
-		$(CC) -M $(CFLAGS) $< > $@;
+		@set -e; $(RM) $@; \
+		$(CC) -M $(CFLAGS) $< > $@.$$$$; \
+		sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
+		$(RM) $@.$$$$
 endef
 
 $(gui_deps): ks_version.h
-- 
1.7.9.2.358.g22243

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