Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 12 Dec 2022 21:57:38 +0100
From:   Nicolas Schier <nicolas@fjasle.eu>
To:     Ian Rogers <irogers@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        bpf@vger.kernel.org, llvm@lists.linux.dev,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH 3/5] tools lib subcmd: Add dependency test to
 install_headers
Message-ID: <Y5eVwlId2A2/pN40@fjasle.eu>
References: <20221202045743.2639466-1-irogers@google.com>
 <20221202045743.2639466-4-irogers@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20221202045743.2639466-4-irogers@google.com>
UI-OutboundReport: notjunk:1;M01:P0:n+AMtI/h5nQ=;uzd76xvlXBHZvc/0DeTuUmklTpb
 8FO3mEpw3fol4NJq85+yLNJrcHHP1fKpUs1QXjlcBU6IKe/E12GRsJ5d+HiHz4pjkQbVszauo
 AJji12/4UPffp8K42/ei4zyYLFdHZ7kHOXGLri9P7NsnAu+SkSqvXkDX5c0zMx8hd26vk3UZQ
 yPSLWSyd2GqEVSXagA9LdzMIjUFRmMdvQd5KN+ZvCItUd5B1FDQgT1ZnXUMoJO+yldMJORKxl
 6+LznW8Ix/4zQpxm99RZ2l/+D+DyWDTK2TXUtrheXC5aKMC83h/jzFUiuj67/sWXKiOMa6ih9
 TA5nuTZjGq/J2YH/ztOBhk9XwW0YayQ3INKYlMD67JlY6MYYkym42b9AFUrA2qikNRhdLxGZI
 8G5Wy2yR+OLGhxJzdYwID48Hm1iPWCvAz24qtfrlBIIQRtANxOb5qAbWS/lYk6VeSEamOd4y9
 ImkhLJ75hMsePDFLKx+pCmz1A9Qv5sL/NHtQkfDOqmoubAoLRXD2vlg5vbOARHg5gRzGIFbaQ
 YItcecrqtpPFk0Yuz8wxVV5/VIec8ypTY0tWruX5nsSUKWUZ+V/nLdieu++oT3BShJ05Dr6eY
 ozO0UGFk5161umJ0GpuSidNQ9PlVS8meDmaAUA+gsMT6q9dQu4up3ivjFUicK4D8/7lpZCc7J
 PK0/aRD3OF5Qr6zMczu8CicEUcxrLXexa55HsKAmCw==
Precedence: bulk

On Thu, Dec 01, 2022 at 08:57:41PM -0800 Ian Rogers wrote:
> Compute the headers to be installed from their source headers and make
> each have its own build target to install it. Using dependencies
> avoids headers being reinstalled and getting a new timestamp which
> then causes files that depend on the header to be rebuilt.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/lib/subcmd/Makefile | 23 +++++++++++++----------
>  1 file changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile
> index 9a316d8b89df..b87213263a5e 100644
> --- a/tools/lib/subcmd/Makefile
> +++ b/tools/lib/subcmd/Makefile
> @@ -89,10 +89,10 @@ define do_install_mkdir
>  endef
>  
>  define do_install
> -	if [ ! -d '$(DESTDIR_SQ)$2' ]; then             \
> -		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \
> +	if [ ! -d '$2' ]; then             \
> +		$(INSTALL) -d -m 755 '$2'; \
>  	fi;                                             \
> -	$(INSTALL) $1 $(if $3,-m $3,) '$(DESTDIR_SQ)$2'
> +	$(INSTALL) $1 $(if $3,-m $3,) '$2'

What about using '$(INSTALL) -D ...' instead of the if-mkdir-block above?
(E.g. as in tools/debugging/Makefile.)

Kind regards,
Nicolas

>  endef
>  
>  install_lib: $(LIBFILE)
> @@ -100,13 +100,16 @@ install_lib: $(LIBFILE)
>  		$(call do_install_mkdir,$(libdir_SQ)); \
>  		cp -fpR $(LIBFILE) $(DESTDIR)$(libdir_SQ)
>  
> -install_headers:
> -	$(call QUIET_INSTALL, libsubcmd_headers) \
> -		$(call do_install,exec-cmd.h,$(prefix)/include/subcmd,644); \
> -		$(call do_install,help.h,$(prefix)/include/subcmd,644); \
> -		$(call do_install,pager.h,$(prefix)/include/subcmd,644); \
> -		$(call do_install,parse-options.h,$(prefix)/include/subcmd,644); \
> -		$(call do_install,run-command.h,$(prefix)/include/subcmd,644);
> +HDRS := exec-cmd.h help.h pager.h parse-options.h run-command.h
> +INSTALL_HDRS_PFX := $(DESTDIR)$(prefix)/include/subcmd
> +INSTALL_HDRS := $(addprefix $(INSTALL_HDRS_PFX)/, $(HDRS))
> +
> +$(INSTALL_HDRS): $(INSTALL_HDRS_PFX)/%.h: %.h
> +	$(call QUIET_INSTALL, $@) \
> +		$(call do_install,$<,$(INSTALL_HDRS_PFX)/,644)
> +
> +install_headers: $(INSTALL_HDRS)
> +	$(call QUIET_INSTALL, libsubcmd_headers)
>  
>  install: install_lib install_headers
>  
> -- 
> 2.39.0.rc0.267.gcb52ba06e7-goog

-- 
epost|xmpp: nicolas@fjasle.eu          irc://oftc.net/nsc
↳ gpg: 18ed 52db e34f 860e e9fb  c82b 7d97 0932 55a0 ce7f
     -- frykten for herren er opphav til kunnskap --