If someone specifies a single target, mixed with O=, the following way: hubble:~/tip/tools/perf> make O=/tmp/perf util/stat.o BUILD: Doing 'make -j8' parallel build gcc -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k [...]
The build might even fail, if a target depends on other targets: hubble:~/tip/tools/perf> make O=/tmp/perf perf.o ... perf.c: In function ‘handle_options’: perf.c:155:21: error: ‘PERF_HTML_PATH’ undeclared (first use in this function) The correct way to invoke such targets is: hubble:~/tip/tools/perf> make O=/tmp/perf /tmp/perf/perf.o BUILD: Doing 'make -j8' parallel build GEN /tmp/perf/common-cmds.h CC /tmp/perf/perf.o But that's unnecessary typing and it's also easy to mistakenly build into the source directory. To fix this remove the generic suffix rules and add redirection to $(OUTPUT) for the most popular .o targets. Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Namhyung Kim <namhy...@kernel.org> Cc: David Ahern <dsah...@gmail.com> Cc: Jiri Olsa <jo...@redhat.com> Link: http://lkml.kernel.org/n/tip-mk0oiukmhgsbrll6chrpk...@git.kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- tools/perf/Makefile.perf | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 178a1c8..a24f6c2 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -576,7 +576,21 @@ $(OUTPUT)perf.o perf.spec \ : $(OUTPUT)PERF-VERSION-FILE .SUFFIXES: -.SUFFIXES: .o .c .S .s + +# +# If a target does not match any of the later rules then prefix it by $(OUTPUT) +# This makes targets like 'make O=/tmp/perf perf.o' work in a natural way. +# +ifneq ($(OUTPUT),) +%.o: $(OUTPUT)%.o + @echo " # Redirected target $@ => $(OUTPUT)$@" +util/%.o: $(OUTPUT)util/%.o + @echo " # Redirected target $@ => $(OUTPUT)util/$@" +bench/%.o: $(OUTPUT)bench/%.o + @echo " # Redirected target $@ => $(OUTPUT)bench/$@" +tests/%.o: $(OUTPUT)tests/%.o + @echo " # Redirected target $@ => $(OUTPUT)tests/$@" +endif # These two need to be here so that when O= is not used they take precedence # over the general rule for .o -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/