On Wed, 2011-08-10 at 14:59 +0200, Michal Marek wrote: > 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. That's always been true; it's *always* been broken like that. But now we're actually *encouraging* people to start setting CONFIG_FOO=y in the environment or the make command line, so we should certainly make it more robust. It should be simple enough to force a reconfig if CONFIG_* is specified in the environment. Actually, while we're at it let's stop just picking it up from the environment and pick it up *only* if it's overridden in the make flags. Something like this will list the variables which are overridden on the command line: CONFIG_OVERRIDES := $(patsubst line:%,%,$(filter line:%,$(foreach var, $(filter CONFIG_%,$(.VARIABLES)), $(origin $(var)):$(var)))) Then we can make auto.conf.cmd trigger a reconfig if it's non-empty, and make the kconfig tool allow overrides *only* for those variables specified in $CONFIG_OVERRIDES... which avoids any worries about "stray" environment variables too. I'll see if I can clean the above expression up and do that. -- David Woodhouse Open Source Technology Centre David.Woodhouse@xxxxxxxxx Intel Corporation -- 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
