kbuild: Warn on selecting symbols with unmet direct dependencies
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@arm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 2e7a048..174b230 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -205,6 +205,16 @@
}
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 @@
}
}
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)