Re: [PATCH bpf-next 1/4] tools/resolve_btfids: Build libbpf and libsubcmd in separate directories

Andrii Nakryiko
2021-02-05T00:40:47Z

On Thu, Feb 4, 2021 at 1:20 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> Setting up separate build directories for libbpf and libpsubcmd,
> so it's separated from other objects and we don't get them mixed
> in the future.
>
> It also simplifies cleaning, which is now simple rm -rf.
>
> Also there's no need for FEATURE-DUMP.libbpf and bpf_helper_defs.h
> files in .gitignore anymore.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/bpf/resolve_btfids/.gitignore | 2 --
> tools/bpf/resolve_btfids/Makefile | 26 +++++++++++---------------
> 2 files changed, 11 insertions(+), 17 deletions(-)
>
> diff --git a/tools/bpf/resolve_btfids/.gitignore b/tools/bpf/resolve_btfids/.gitignore
> index a026df7dc280..25f308c933cc 100644
> --- a/tools/bpf/resolve_btfids/.gitignore
> +++ b/tools/bpf/resolve_btfids/.gitignore
> @@ -1,4 +1,2 @@
> -/FEATURE-DUMP.libbpf
> -/bpf_helper_defs.h
> /fixdep
> /resolve_btfids
> diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> index bf656432ad73..b780b3a9fb07 100644
> --- a/tools/bpf/resolve_btfids/Makefile
> +++ b/tools/bpf/resolve_btfids/Makefile
> @@ -28,22 +28,22 @@ OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
> LIBBPF_SRC := $(srctree)/tools/lib/bpf/
> SUBCMD_SRC := $(srctree)/tools/lib/subcmd/
>
> -BPFOBJ := $(OUTPUT)/libbpf.a
> -SUBCMDOBJ := $(OUTPUT)/libsubcmd.a
> +BPFOBJ := $(OUTPUT)/libbpf/libbpf.a
> +SUBCMDOBJ := $(OUTPUT)/libsubcmd/libsubcmd.a
>
> BINARY := $(OUTPUT)/resolve_btfids
> BINARY_IN := $(BINARY)-in.o
>
> all: $(BINARY)
>
> -$(OUTPUT):
> +$(OUTPUT) $(OUTPUT)/libbpf $(OUTPUT)/libsubcmd:
> $(call msg,MKDIR,,$@)
> - $(Q)mkdir -p $(OUTPUT)
> + $(Q)mkdir -p $(@)
>
> -$(SUBCMDOBJ): fixdep FORCE
> - $(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(OUTPUT)
> +$(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
> + $(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
>
> -$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)
> +$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)/libbpf
> $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
>
> CFLAGS := -g \
> @@ -57,23 +57,19 @@ LIBS = -lelf -lz
> export srctree OUTPUT CFLAGS Q
> include $(srctree)/tools/build/Makefile.include
>
> -$(BINARY_IN): fixdep FORCE
> +$(BINARY_IN): fixdep FORCE | $(OUTPUT)
> $(Q)$(MAKE) $(build)=resolve_btfids
>
> $(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
> $(call msg,LINK,$@)
> $(Q)$(CC) $(BINARY_IN) $(LDFLAGS) -o $@ $(BPFOBJ) $(SUBCMDOBJ) $(LIBS)
>
> -libsubcmd-clean:
> - $(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(OUTPUT) clean
> -
> -libbpf-clean:
> - $(Q)$(MAKE) -C $(LIBBPF_SRC) OUTPUT=$(OUTPUT) clean
> -
> -clean: libsubcmd-clean libbpf-clean fixdep-clean
> +clean: fixdep-clean
> $(call msg,CLEAN,$(BINARY))
> $(Q)$(RM) -f $(BINARY); \
> $(RM) -rf $(if $(OUTPUT),$(OUTPUT),.)/feature; \
> + $(RM) -rf $(OUTPUT)libbpf; \
> + $(RM) -rf $(OUTPUT)libsubcmd; \

If someone specifies OUTPUT=bla, you will attempt to delete blalibbpf,
not bla/libbpf

> find $(if $(OUTPUT),$(OUTPUT),.) -name \*.o -or -name \*.o.cmd -or -name \*.o.d | xargs $(RM)
>
> tags:
> --
> 2.26.2
>