The "select" statement in Kconfig files allows the enabling of options even if they have unmet direct dependencies (i.e. "depends on" expands to "no"). Currently, the "depends on" clauses are used in calculating the visibility but they do not affect the reverse dependencies in any way. The patch introduces additional tracking of the "depends on" statements and prints a warning on selecting an option if its direct dependencies are not met. Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> --- This patch differs slightly from the one I posted a month ago. It only warns about selecting symbols with unmet dependencies rather than refusing to enable the feature, making it much safer. It also prints information about what's selecting the symbol, something like below (select done for testing only, not a real situation): warning: (MACH_REALVIEW_EB && ARCH_REALVIEW) selects DEBUG_SLAB which has unmet direct dependencies (DEBUG_KERNEL && SLAB && !KMEMCHECK) scripts/kconfig/expr.h | 2 ++ scripts/kconfig/menu.c | 5 +++++ scripts/kconfig/symbol.c | 18 ++++++++++++++++++ 3 files changed, 25 insertions(+), 0 deletions(-) diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 6408fef..c8be420 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -83,6 +83,7 @@ struct symbol { tristate visible; int flags; struct property *prop; + struct expr_value dir_dep; struct expr_value rev_dep; }; @@ -164,6 +165,7 @@ struct menu { struct symbol *sym; struct property *prompt; struct expr *dep; + struct expr *dir_dep; unsigned int flags; char *help; struct file *file; diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c index 07ff8d1..16e713f 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -102,6 +102,7 @@ struct expr *menu_check_dep(struct expr *e) void menu_add_dep(struct expr *dep) { current_entry->dep = expr_alloc_and(current_entry->dep, menu_check_dep(dep)); + current_entry->dir_dep = current_entry->dep; } void menu_set_type(int type) @@ -285,6 +286,10 @@ void menu_finalize(struct menu *parent) for (menu = parent->list; menu; menu = menu->next) menu_finalize(menu); } else if (sym) { + /* ignore inherited dependencies for dir_dep */ + sym->dir_dep.expr = expr_transform(expr_copy(parent->dir_dep)); + sym->dir_dep.expr = expr_eliminate_dups(sym->dir_dep.expr); + basedep = parent->prompt ? parent->prompt->visible.expr : NULL; basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no); basedep = expr_eliminate_dups(expr_transform(basedep)); diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c index 18f3e5c..a0826dc 100644 --- a/scripts/kconfig/symbol.c +++ b/scripts/kconfig/symbol.c @@ -205,6 +205,16 @@ static void sym_calc_visibility(struct symbol *sym) } if (sym_is_choice_value(sym)) return; + /* defaulting to "yes" if no explicit "depends on" are given */ + tri = yes; + if (sym->dir_dep.expr) + tri = expr_calc_value(sym->dir_dep.expr); + if (tri == mod) + tri = yes; + if (sym->dir_dep.tri != tri) { + sym->dir_dep.tri = tri; + sym_set_changed(sym); + } tri = no; if (sym->rev_dep.expr) tri = expr_calc_value(sym->rev_dep.expr); @@ -321,6 +331,14 @@ void sym_calc_value(struct symbol *sym) } } calc_newval: + if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) { + fprintf(stderr, "warning: ("); + expr_fprint(sym->rev_dep.expr, stderr); + fprintf(stderr, ") selects %s which has unmet direct dependencies (", + sym->name); + expr_fprint(sym->dir_dep.expr, stderr); + fprintf(stderr, ")\n"); + } newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri); } if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN) -- 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