On 9.8.2011 17:26, Arnaud Lacombe wrote: > On Tue, Aug 9, 2011 at 10:14 AM, Michal Marek <mmarek@xxxxxxx> wrote: >> On 31.7.2011 02:05, Arnaud Lacombe wrote: >>> Because kconfig might not be ran exclusively from a fully controlled >>> and restricted environment ? Not to mention that it is used by other >>> people than the linux kernel folks. >> >> Well, it has always been possible to trick kbuild (not kconfig) into >> accepting CONFIG_* options from environment, because unset kconfig options >> in auto.conf are not seen by make. Of course this is completely fragile, >> because there is no dependency checking and such variables are only seen by >> make and do not appear in autoconf.h. So a patch that teaches kconfig to >> read options from the environment would actually make some (albeit currently >> "illegal") use cases work correctly :). >> > kconfig can already set symbol value from the environment. The only > limitation I can see is that it is not optional and require an > explicit environment variable name. I wasn't talking about the env= syntax, but about make CONFIG_EXT2_FS=m all which makes kbuild visit fs/ext2 even if CONFIG_EXT2_FS is disabled in .config. With no update of the configuration or checking the dependencies. Hm, actually this would be a problem even if kconfig does read the CONFIG_* variables from the environment, because it could result in a mismatch if kconfig determines that the variable cannot be set, but make still sees it in the environment. So we would have to use 'undefine CONFIG_FOO' instead of '# CONFIG_FOO is not set' in include/config/auto.conf, to be able to properly support make CONFIG_FOO=y. Michal -- 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
