kconfig: fix tristate choice with minimal config

If a minimal config did not specify the value
of all choice values, the resulting configuration
could have wrong values.

Consider following example:
config M
        def_bool y
        option modules
choice
        prompt "choice list"
config A
        tristate "a"
config B
	tristate "b"
endchoice

With a defconfig like this:
CONFIG_M=y
CONFIG_A=y

The resulting configuration would have

    CONFIG_A=m

which was unexpected.

The problem was not not all choice values were set and thus
kconfig calculated a wrong value.

The fix is to set all choice values when we
read a defconfig files.

conf_set_all_new_symbols() is refactored such that
random choice values are now handled by a dedicated function.
And new choice values are set by set_all_choice_values().

This was not the minimal fix, but the fix that resulted
in the most readable code.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reported-by: Arve Hjønnevåg <arve@android.com>
Tested-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index e5d66e4..ac13f0f 100644 (file)
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -918,13 +918,73 @@ void conf_set_changed_callback(void (*fn)(void))
        conf_changed_callback = fn;
 }
 
+static void randomize_choice_values(struct symbol *csym)
+{
+       struct property *prop;
+       struct symbol *sym;
+       struct expr *e;
+       int cnt, def;
 
-void conf_set_all_new_symbols(enum conf_def_mode mode)
+       /*
+        * If choice is mod then we may have more items slected
+        * and if no then no-one.
+        * In both cases stop.
+        */
+       if (csym->curr.tri != yes)
+               return;
+
+       prop = sym_get_choice_prop(csym);
+
+       /* count entries in choice block */
+       cnt = 0;
+       expr_list_for_each_sym(prop->expr, e, sym)
+               cnt++;
+
+       /*
+        * find a random value and set it to yes,
+        * set the rest to no so we have only one set
+        */
+       def = (rand() % cnt);
+
+       cnt = 0;
+       expr_list_for_each_sym(prop->expr, e, sym) {
+               if (def == cnt++) {
+                       sym->def[S_DEF_USER].tri = yes;
+                       csym->def[S_DEF_USER].val = sym;
+               }
+               else {
+                       sym->def[S_DEF_USER].tri = no;
+               }
+       }
+       csym->flags |= SYMBOL_DEF_USER;
+       /* clear VALID to get value calculated */
+       csym->flags &= ~(SYMBOL_VALID);
+}
+
+static void set_all_choice_values(struct symbol *csym)
 {
-       struct symbol *sym, *csym;
        struct property *prop;
+       struct symbol *sym;
        struct expr *e;
-       int i, cnt, def;
+
+       prop = sym_get_choice_prop(csym);
+
+       /*
+        * Set all non-assinged choice values to no
+        */
+       expr_list_for_each_sym(prop->expr, e, sym) {
+               if (!sym_has_value(sym))
+                       sym->def[S_DEF_USER].tri = no;
+       }
+       csym->flags |= SYMBOL_DEF_USER;
+       /* clear VALID to get value calculated */
+       csym->flags &= ~(SYMBOL_VALID);
+}
+
+void conf_set_all_new_symbols(enum conf_def_mode mode)
+{
+       struct symbol *sym, *csym;
+       int i, cnt;
 
        for_all_symbols(i, sym) {
                if (sym_has_value(sym))
@@ -960,8 +1020,6 @@ void conf_set_all_new_symbols(enum conf_def_mode mode)
 
        sym_clear_all_valid();
 
-       if (mode != def_random)
-               return;
        /*
         * We have different type of choice blocks.
         * If curr.tri equal to mod then we can select several
@@ -976,35 +1034,9 @@ void conf_set_all_new_symbols(enum conf_def_mode mode)
                        continue;
 
                sym_calc_value(csym);
-
-               if (csym->curr.tri != yes)
-                       continue;
-
-               prop = sym_get_choice_prop(csym);
-
-               /* count entries in choice block */
-               cnt = 0;
-               expr_list_for_each_sym(prop->expr, e, sym)
-                       cnt++;
-
-               /*
-                * find a random value and set it to yes,
-                * set the rest to no so we have only one set
-                */
-               def = (rand() % cnt);
-
-               cnt = 0;
-               expr_list_for_each_sym(prop->expr, e, sym) {
-                       if (def == cnt++) {
-                               sym->def[S_DEF_USER].tri = yes;
-                               csym->def[S_DEF_USER].val = sym;
-                       }
-                       else {
-                               sym->def[S_DEF_USER].tri = no;
-                       }
-               }
-               csym->flags |= SYMBOL_DEF_USER;
-               /* clear VALID to get value calculated */
-               csym->flags &= ~(SYMBOL_VALID);
+               if (mode == def_random)
+                       randomize_choice_values(csym);
+               else
+                       set_all_choice_values(csym);
        }
 }