Re: [PATCH 2/3] perf build: Use FEATURE-INCLUDE in bpf subproject

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Nov 26, 2015 at 02:54:03PM +0100, Jiri Olsa escreveu:
> Using FEATURE-INCLUDE in bpf subproject in case bpf is built
> via perf. Keep the current features detection for other cases.
> 
> Cc: Wang Nan <wangnan0@huawei.com>
> Link: http://lkml.kernel.org/n/tip-utuczk899ckz6qtggqvhm7yu@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Clashes with:

d8ad6a15cc3a ("tools lib bpf: Don't do a feature check when cleaning")

That has, at that point:

+check_feat := 1
+NON_CHECK_FEAT_TARGETS := clean TAGS tags cscope help
+ifdef MAKECMDGOALS
+ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
+  check_feat := 0
+endif
+endif
+
+ifeq ($(check_feat),1)
 include $(srctree)/tools/build/Makefile.feature
+endif

On a related note:

  [acme@zoo linux]$ make O=/tmp/build/perf -C tools/perf
  make: Entering directory '/home/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
  make[2]: Nothing to be done for 'fixdep'.
  make: Leaving directory '/home/git/linux/tools/perf'

Can we get away with that "make[2]: Nothing to be done for 'fixdep'."
line?

- Arnaldo

> ---
>  tools/lib/bpf/Makefile   | 4 ++++
>  tools/perf/Makefile.perf | 2 +-
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> index a3caaf3eafbd..f0818f3b0d40 100644
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -71,7 +71,11 @@ FEATURE_DISPLAY = libelf bpf
>  INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/arch/$(ARCH)/include/uapi -I$(srctree)/include/uapi
>  FEATURE_CHECK_CFLAGS-bpf = $(INCLUDES)
>  
> +ifeq ($(FEATURES_INCLUDE),)
>  include $(srctree)/tools/build/Makefile.feature
> +else
> +include $(FEATURES_INCLUDE)
> +endif
>  
>  export prefix libdir src obj
>  
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 97badfa2a195..d2b20a1f4a21 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -431,7 +431,7 @@ $(LIBAPI)-clean:
>  	$(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) clean >/dev/null
>  
>  $(LIBBPF): fixdep FORCE
> -	$(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a
> +	$(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_INCLUDE=$(realpath $(OUTPUT)FEATURE-INCLUDE)
>  
>  $(LIBBPF)-clean:
>  	$(call QUIET_CLEAN, libbpf)
> -- 
> 2.4.3