From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masahiro Yamada Date: Thu, 11 Feb 2016 16:59:31 +0900 Subject: [U-Boot] [PATCH V3] Makefile: remove BUILD_TAG from KBUILD_CFLAGS In-Reply-To: <1455142579-29342-1-git-send-email-swarren@wwwdotorg.org> References: <1455142579-29342-1-git-send-email-swarren@wwwdotorg.org> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 2016-02-11 7:16 GMT+09:00 Stephen Warren : > From: Stephen Warren > > If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, > all files get rebuilt. In a continuous integration environment, the value > will change every build. This wastes time, assuming that incremental > builds would otherwise occur. > > To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS > for just the one file that uses it. This does have the disadvantage that > if any other files want to use the flag, we'll need to duplicate this > custom CFLAGS setup logic. However, it seems unlikely we'll need this. > > An alternative would be to add BUILD_TAG to the "local version" and remove > the special case code from display_options.c. However, that would affect > the format of the U-Boot signon message, which may negatively affect > people looking for specific data there. The approach of using > file-specific CFLAGS was suggested by Masahiro Yamada. > > Signed-off-by: Stephen Warren > --- > v3: Undo accidental removal of bch.o. > v2: Set CFLAGS on display_options.c rather than modifying > scripts/setlocalversion to add BUILD_TAG to the local version. Reviewed-by: Masahiro Yamada -- Best Regards Masahiro Yamada