Re: [PATCH bpf-next] bpftool: Remove redundant slashes

Song Liu
2022-02-26T06:09:28Z

On Fri, Feb 25, 2022 at 8:15 AM Yuntao Wang <ytcoode@gmail.com> wrote:
>
> Since the _OUTPUT variable holds a value ending with a trailing slash,

While the change makes sense, I think the description here is not accurate.
Currently, we require OUTPUT to end with trailing slash. However, if
OUTPUT is not defined, _OUTPUT will not hold a trailing slash. Adding
trailing slash to _OUTPUT is one part of this patch, so I think we should not
say that's the reason of this change.

Thanks,
Song

> there is no need to add another one when defining BOOTSTRAP_OUTPUT and
> LIBBPF_OUTPUT variables.
>
> When defining LIBBPF_INCLUDE and LIBBPF_BOOTSTRAP_INCLUDE, we shouldn't
> add an extra slash either for the same reason.
>
> When building libbpf, the value of the DESTDIR argument should also not
> end with a trailing slash.
>
> Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
> ---
> tools/bpf/bpftool/Makefile | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
> index ba647aede0d6..9800f966fd51 100644
> --- a/tools/bpf/bpftool/Makefile
> +++ b/tools/bpf/bpftool/Makefile
> @@ -18,19 +18,19 @@ BPF_DIR = $(srctree)/tools/lib/bpf
> ifneq ($(OUTPUT),)
> _OUTPUT := $(OUTPUT)
> else
> - _OUTPUT := $(CURDIR)
> + _OUTPUT := $(CURDIR)/
> endif
> -BOOTSTRAP_OUTPUT := $(_OUTPUT)/bootstrap/
> +BOOTSTRAP_OUTPUT := $(_OUTPUT)bootstrap/
>
> -LIBBPF_OUTPUT := $(_OUTPUT)/libbpf/
> +LIBBPF_OUTPUT := $(_OUTPUT)libbpf/
> LIBBPF_DESTDIR := $(LIBBPF_OUTPUT)
> -LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)/include
> +LIBBPF_INCLUDE := $(LIBBPF_DESTDIR)include
> LIBBPF_HDRS_DIR := $(LIBBPF_INCLUDE)/bpf
> LIBBPF := $(LIBBPF_OUTPUT)libbpf.a
>
> LIBBPF_BOOTSTRAP_OUTPUT := $(BOOTSTRAP_OUTPUT)libbpf/
> LIBBPF_BOOTSTRAP_DESTDIR := $(LIBBPF_BOOTSTRAP_OUTPUT)
> -LIBBPF_BOOTSTRAP_INCLUDE := $(LIBBPF_BOOTSTRAP_DESTDIR)/include
> +LIBBPF_BOOTSTRAP_INCLUDE := $(LIBBPF_BOOTSTRAP_DESTDIR)include
> LIBBPF_BOOTSTRAP_HDRS_DIR := $(LIBBPF_BOOTSTRAP_INCLUDE)/bpf
> LIBBPF_BOOTSTRAP := $(LIBBPF_BOOTSTRAP_OUTPUT)libbpf.a
>
> @@ -44,7 +44,7 @@ $(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(LIBBPF_BOOTSTRAP_OUTPUT) $(LIBBPF_HDRS_DI
>
> $(LIBBPF): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_OUTPUT)
> $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) \
> - DESTDIR=$(LIBBPF_DESTDIR) prefix= $(LIBBPF) install_headers
> + DESTDIR=$(LIBBPF_DESTDIR:/=) prefix= $(LIBBPF) install_headers
>
> $(LIBBPF_INTERNAL_HDRS): $(LIBBPF_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_HDRS_DIR)
> $(call QUIET_INSTALL, $@)
> @@ -52,7 +52,7 @@ $(LIBBPF_INTERNAL_HDRS): $(LIBBPF_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_HDRS_
>
> $(LIBBPF_BOOTSTRAP): $(wildcard $(BPF_DIR)/*.[ch] $(BPF_DIR)/Makefile) | $(LIBBPF_BOOTSTRAP_OUTPUT)
> $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) \
> - DESTDIR=$(LIBBPF_BOOTSTRAP_DESTDIR) prefix= \
> + DESTDIR=$(LIBBPF_BOOTSTRAP_DESTDIR:/=) prefix= \
> ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) $@ install_headers
>
> $(LIBBPF_BOOTSTRAP_INTERNAL_HDRS): $(LIBBPF_BOOTSTRAP_HDRS_DIR)/%.h: $(BPF_DIR)/%.h | $(LIBBPF_BOOTSTRAP_HDRS_DIR)
> --
> 2.35.1
>