2018-02-13 16:58 GMT+09:00 Ulf Magnusson <ulfalizer@xxxxxxxxx>: > The comment above the silentoldconfig invocation is outdated. > 'make oldconfig' updates just .config and doesn't touch the > include/config/ tree. > > This came up in https://lkml.org/lkml/2018/2/12/415. > > While fixing the comment, make it more informative by explaining the > purpose of the unfortunately named silentoldconfig. > > I can't make sense of the comment re. auto.conf.cmd and a cleaned tree. > include/config/auto.conf and include/config/auto.conf.cmd are both > created simultaneously by silentoldconfig (in > scripts/kconfig/confdata.c, by conf_write_autoconf()), and nothing seems > to remove auto.conf.cmd that wouldn't remove auto.conf. Remove that part > of the comment rather than blindly copying it. It might be a leftover > from an older way of doing things. > > The include/config/auto.conf.cmd prerequisite might be there to ensure > that silentoldconfig gets rerun if conf_write_autoconf() fails between > writing out auto.conf.cmd and auto.conf (a comment in the function > indicates that auto.conf is deliberately written out last to mark > completion of the operation). It seems the Makefile dependency between > include/config/auto.conf and .config would already take care of that > though, since include/config/auto.conf would still be out of date re. > .config if the operation fails. > > Cop out and leave the prerequisite in for now. > > Signed-off-by: Ulf Magnusson <ulfalizer@xxxxxxxxx> > --- > Changes in v2: > include/config/auto.conf depends on .config, not the other way around, so swap > them in some places in the commit message to make it less confusing. > > Makefile | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/Makefile b/Makefile > index 79ad2bfa24b6..61ed99ad4b1b 100644 > --- a/Makefile > +++ b/Makefile > @@ -579,10 +579,13 @@ ifeq ($(KBUILD_EXTMOD),) > # To avoid any implicit rule to kick in, define an empty command > $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ; > > -# If .config is newer than include/config/auto.conf, someone tinkered > -# with it and forgot to run make oldconfig. > -# if auto.conf.cmd is missing then we are probably in a cleaned tree so > -# we execute the config step to be sure to catch updated Kconfig files > +# The actual configuration files used during the build are stored in > +# include/generated/ and include/config/. Update them if .config is newer than > +# include/config/auto.conf (which mirrors .config). Yes, the first paragraph perfectly explains the code. > +# The include/config/ tree manages dependencies between source files and > +# Kconfig symbols and lets us avoid doing a full rebuild whenever the > +# configuration is changed. See scripts/basic/fixdep.c Do you insist on this paragraph? I know silentoldconfig touches include/config/* for extra cleverness, but, to me, this looks unnecessary information to understand the following code. > include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd > $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > else -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
