A select of an unknown symbol is basically treated as a nop and is silently skipped. This is annoying if the selected symbol contains a typo. It can also hide the fact that a treewide symbol cleanup was only done partially.
There are also a few cases were this might have been done on purpose. But that anti-pattern should be discouraged. Almost all select statements point to a known and reachable symbol. So people will likely assume that any selected symbol is actually set. Violating that assumption might lead to (subtle) bugs. So let's warn when we notice a select of a symbol that is not known in the configuration we're creating. Rfced-by: Paul Bolle <[email protected]> --- scripts/kconfig/conf.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c index fef75fc756f4..de8406287531 100644 --- a/scripts/kconfig/conf.c +++ b/scripts/kconfig/conf.c @@ -446,6 +446,45 @@ static void check_conf(struct menu *menu) check_conf(child); } +static void check_selects(struct menu *menu) +{ + struct symbol *sym, *sel; + struct property *prop; + + while (menu) { + sym = menu->sym; + + if (sym && !sym_is_choice(sym) && + sym->type != S_UNKNOWN && + sym->flags & SYMBOL_WRITE) { + for_all_properties(sym, prop, P_SELECT) { + sel = prop->expr->left.sym; + if (sel->type == S_UNKNOWN && + expr_calc_value(prop->visible.expr) != no) { + fprintf(stderr, "%s:%d:warning: ", + prop->file->name, + prop->lineno); + fprintf(stderr, + "'%s' selects unknown symbol '%s'\n", + sym->name, + sel->name); + } + } + } + + if (menu->list) { + menu = menu->list; + } else if (menu->next) { + menu = menu->next; + } else while ((menu = menu->parent)) { + if (menu->next) { + menu = menu->next; + break; + } + } + } +} + static struct option long_opts[] = { {"oldaskconfig", no_argument, NULL, oldaskconfig}, {"oldconfig", no_argument, NULL, oldconfig}, @@ -681,6 +720,8 @@ int main(int ac, char **av) break; } + check_selects(rootmenu.list); + if (sync_kconfig) { /* silentoldconfig is used during the build so we shall update autoconf. * All other commands are only used to generate a config. -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
