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>

1 files changed, 67 insertions, 35 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index e5d66e4f1484..ac13f0ff8e81 100644
--- 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);
         }
 }