tools/perf/build: Add 'autodep' functionality, generate feature test dependencies automatically
Use GCC's -MD feature to generate a dependency file for each feature test .c file,
and include that .d file in the config/feature-checks/Makefile.
This allows us to do two things:
- speed up feature tests
- detect removal or changes in build dependencies - including system libraries/headers
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-Jfma8pmPnnqzpxjbs3hpgmsj@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/perf/config/feature-checks/Makefile b/tools/perf/config/feature-checks/Makefile
index b3f6372..4708cca 100644
--- a/tools/perf/config/feature-checks/Makefile
+++ b/tools/perf/config/feature-checks/Makefile
@@ -1,16 +1,20 @@
FILES=test-hello
+CC := $(CC) -MD
+
all: $(FILES)
BUILD = $(CC) -o $(OUTPUT)$@ $@.c
###############################
-test-hello: test-hello.c
+test-hello:
$(BUILD)
+-include *.d */*.d
+
###############################
clean:
- rm -f $(FILES)
+ rm -f $(FILES) *.d