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kconfig: refactor choice value calculation

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Handling choices has always been in a PITA in Kconfig.

For example, fixes and reverts were repeated for randconfig with
KCONFIG_ALLCONFIG:

 - 422c809f03 ("kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG")
 - 23a5dfdad2 ("Revert "kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG"")
 - 8357b48549 ("kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG")
 - 490f161711 ("Revert "kconfig: fix randomising choice entries in presence of KCONFIG_ALLCONFIG"")

As these commits pointed out, randconfig does not randomize choices when
KCONFIG_ALLCONFIG is used. This issue still remains.

[Test Case]

    choice
            prompt "choose"

    config A
            bool "A"

    config B
            bool "B"

    endchoice

    $ echo > all.config
    $ make KCONFIG_ALLCONFIG=1 randconfig

The output is always as follows:

    CONFIG_A=y
    # CONFIG_B is not set

Not only randconfig, but other all*config variants are also broken with
KCONFIG_ALLCONFIG.

With the same Kconfig,

    $ echo '# CONFIG_A is not set' > all.config
    $ make KCONFIG_ALLCONFIG=1 allyesconfig

You will get this:

    CONFIG_A=y
    # CONFIG_B is not set

This is incorrect because it does not respect all.config.

The correct output should be:

    # CONFIG_A is not set
    CONFIG_B=y

To handle user inputs more accurately, this commit refactors the code
based on the following principles:

 - When a user value is given, Kconfig must set it immediately.
   Do not defer it by setting SYMBOL_NEED_SET_CHOICE_VALUES.

 - The SYMBOL_DEF_USER flag must not be cleared, unless a new config
   file is loaded. Kconfig must not forget user inputs.

In addition, user values for choices must be managed with priority.
If user inputs conflict within a choice block, the newest value wins.
The values given by randconfig have lower priority than explicit user
inputs.

This commit implements it by using a linked list. Every time a choice
block gets a new input, it is moved to the top of the list.

Let me explain how it works.

Let's say, we have a choice block that consists of five symbols:
A, B, C, D, and E.

Initially, the linked list looks like this:

    A(=?) --> B(=?) --> C(=?) --> D(=?) --> E(=?)

Suppose randconfig is executed with the following KCONFIG_ALLCONFIG:

    CONFIG_C=y
    # CONFIG_A is not set
    CONFIG_D=y

First, CONFIG_C=y is read. C is set to 'y' and moved to the top.

    C(=y) --> A(=?) --> B(=?) --> D(=?) --> E(=?)

Next, '# CONFIG_A is not set' is read. A is set to 'n' and moved to
the top.

    A(=n) --> C(=y) --> B(=?) --> D(=?) --> E(=?)

Then, 'CONFIG_D=y' is read. D is set to 'y' and moved to the top.

    D(=y) --> A(=n) --> C(=y) --> B(=?) --> E(=?)

Lastly, randconfig shuffles the order of the remaining symbols,
resulting in:

    D(=y) --> A(=n) --> C(=y) --> B(=y) --> E(=y)
or
    D(=y) --> A(=n) --> C(=y) --> E(=y) --> B(=y)

When calculating the output, the linked list is traversed and the first
visible symbol with 'y' is taken. In this case, it is D if visible.

If D is hidden by 'depends on', the next node, A, is examined. Since
it is already specified as 'n', it is skipped. Next, C is checked, and
selected if it is visible.

If C is also invisible, either B or E is chosen as a result of the
randomization.

If B and E are also invisible, the linked list is traversed in the
reverse order, and the least prioritized 'n' symbol is chosen. It is
A in this case.

Now, Kconfig remembers all user values. This is a big difference from
the previous implementation, where Kconfig would forget CONFIG_C=y when
CONFIG_D=y appeared in the same input file.

The new appaorch respects user-specified values as much as possible.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2024-06-18 19:35:21 +09:00
parent ee29e6204c
commit f79dc03fe6
7 changed files with 187 additions and 197 deletions
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131
scripts/kconfig/conf.c
View File

@ -114,41 +114,54 @@ static void set_randconfig_seed(void)
srand(seed);
}
static void randomize_choice_values(struct symbol *csym)
/**
* randomize_choice_values - randomize choice block
*
* @choice: menu entry for the choice
*/
static void randomize_choice_values(struct menu *choice)
{
struct property *prop;
struct symbol *sym;
struct expr *e;
int cnt, def;
prop = sym_get_choice_prop(csym);
/* count entries in choice block */
cnt = 0;
expr_list_for_each_sym(prop->expr, e, sym)
cnt++;
struct menu *menu;
int x;
int cnt = 0;
/*
* find a random value and set it to yes,
* set the rest to no so we have only one set
* First, count the number of symbols to randomize. If sym_has_value()
* is true, it was specified by KCONFIG_ALLCONFIG. It needs to be
* respected.
*/
def = rand() % cnt;
menu_for_each_sub_entry(menu, choice) {
struct symbol *sym = menu->sym;
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;
}
sym->flags |= SYMBOL_DEF_USER;
/* clear VALID to get value calculated */
sym->flags &= ~SYMBOL_VALID;
if (sym && !sym_has_value(sym))
cnt++;
}
while (cnt > 0) {
x = rand() % cnt;
menu_for_each_sub_entry(menu, choice) {
struct symbol *sym = menu->sym;
if (sym && !sym_has_value(sym))
x--;
if (x < 0) {
sym->def[S_DEF_USER].tri = yes;
sym->flags |= SYMBOL_DEF_USER;
/*
* Move the selected item to the _tail_ because
* this needs to have a lower priority than the
* user input from KCONFIG_ALLCONFIG.
*/
list_move_tail(&sym->choice_link,
&choice->choice_members);
break;
}
}
cnt--;
}
csym->flags |= SYMBOL_DEF_USER;
/* clear VALID to get value calculated */
csym->flags &= ~SYMBOL_VALID;
}
enum conf_def_mode {
@ -159,9 +172,9 @@ enum conf_def_mode {
def_random
};
static bool conf_set_all_new_symbols(enum conf_def_mode mode)
static void conf_set_all_new_symbols(enum conf_def_mode mode)
{
struct symbol *sym, *csym;
struct menu *menu;
int cnt;
/*
* can't go as the default in switch-case below, otherwise gcc whines
@ -170,7 +183,6 @@ static bool conf_set_all_new_symbols(enum conf_def_mode mode)
int pby = 50; /* probability of bool = y */
int pty = 33; /* probability of tristate = y */
int ptm = 33; /* probability of tristate = m */
bool has_changed = false;
if (mode == def_random) {
int n, p[3];
@ -217,14 +229,21 @@ static bool conf_set_all_new_symbols(enum conf_def_mode mode)
}
}
for_all_symbols(sym) {
menu_for_each_entry(menu) {
struct symbol *sym = menu->sym;
tristate val;
if (sym_has_value(sym) || sym->flags & SYMBOL_VALID ||
(sym->type != S_BOOLEAN && sym->type != S_TRISTATE))
if (!sym || !menu->prompt || sym_has_value(sym) ||
(sym->type != S_BOOLEAN && sym->type != S_TRISTATE) ||
sym_is_choice_value(sym))
continue;
has_changed = true;
if (sym_is_choice(sym)) {
if (mode == def_random)
randomize_choice_values(menu);
continue;
}
switch (mode) {
case def_yes:
val = yes;
@ -251,34 +270,10 @@ static bool conf_set_all_new_symbols(enum conf_def_mode mode)
continue;
}
sym->def[S_DEF_USER].tri = val;
if (!(sym_is_choice(sym) && mode == def_random))
sym->flags |= SYMBOL_DEF_USER;
sym->flags |= SYMBOL_DEF_USER;
}
sym_clear_all_valid();
if (mode != def_random) {
for_all_symbols(csym) {
if ((sym_is_choice(csym) && !sym_has_value(csym)) ||
sym_is_choice_value(csym))
csym->flags |= SYMBOL_NEED_SET_CHOICE_VALUES;
}
}
for_all_symbols(csym) {
if (sym_has_value(csym) || !sym_is_choice(csym))
continue;
sym_calc_value(csym);
if (mode == def_random)
randomize_choice_values(csym);
else
set_all_choice_values(csym);
has_changed = true;
}
return has_changed;
}
static void conf_rewrite_tristates(tristate old_val, tristate new_val)
@ -429,10 +424,9 @@ static void conf_choice(struct menu *menu)
{
struct symbol *sym, *def_sym;
struct menu *child;
bool is_new;
bool is_new = false;
sym = menu->sym;
is_new = !sym_has_value(sym);
while (1) {
int cnt, def;
@ -456,8 +450,10 @@ static void conf_choice(struct menu *menu)
printf("%*c", indent, ' ');
printf(" %d. %s (%s)", cnt, menu_get_prompt(child),
child->sym->name);
if (!sym_has_value(child->sym))
if (!sym_has_value(child->sym)) {
is_new = true;
printf(" (NEW)");
}
printf("\n");
}
printf("%*schoice", indent - 1, "");
@ -586,9 +582,7 @@ static void check_conf(struct menu *menu)
return;
sym = menu->sym;
if (sym && !sym_has_value(sym) &&
(sym_is_changeable(sym) || sym_is_choice(sym))) {
if (sym && !sym_has_value(sym) && sym_is_changeable(sym)) {
switch (input_mode) {
case listnewconfig:
if (sym->name)
@ -804,8 +798,7 @@ int main(int ac, char **av)
conf_set_all_new_symbols(def_default);
break;
case randconfig:
/* Really nothing to do in this loop */
while (conf_set_all_new_symbols(def_random)) ;
conf_set_all_new_symbols(def_random);
break;
case defconfig:
conf_set_all_new_symbols(def_default);

54
scripts/kconfig/confdata.c
View File

@ -382,10 +382,7 @@ load:
def_flags = SYMBOL_DEF << def;
for_all_symbols(sym) {
sym->flags |= SYMBOL_CHANGED;
sym->flags &= ~(def_flags|SYMBOL_VALID);
if (sym_is_choice(sym))
sym->flags |= def_flags;
switch (sym->type) {
case S_INT:
case S_HEX:
@ -399,6 +396,8 @@ load:
}
while (getline_stripped(&line, &line_asize, in) != -1) {
struct menu *choice;
conf_lineno++;
if (!line[0]) /* blank line */
@ -460,15 +459,14 @@ load:
if (conf_set_sym_val(sym, def, def_flags, val))
continue;
if (sym && sym_is_choice_value(sym)) {
struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
if (sym->def[def].tri == yes) {
if (cs->def[def].tri != no)
conf_warning("override: %s changes choice state", sym->name);
cs->def[def].val = sym;
cs->def[def].tri = yes;
}
}
/*
* If this is a choice member, give it the highest priority.
* If conflicting CONFIG options are given from an input file,
* the last one wins.
*/
choice = sym_get_choice_menu(sym);
if (choice)
list_move(&sym->choice_link, &choice->choice_members);
}
free(line);
fclose(in);
@ -514,18 +512,6 @@ int conf_read(const char *name)
/* maybe print value in verbose mode... */
}
for_all_symbols(sym) {
if (sym_has_value(sym) && !sym_is_choice_value(sym)) {
/* Reset values of generates values, so they'll appear
* as new, if they should become visible, but that
* doesn't quite work if the Kconfig and the saved
* configuration disagree.
*/
if (sym->visible == no && !conf_unsaved)
sym->flags &= ~SYMBOL_DEF_USER;
}
}
if (conf_warnings || conf_unsaved)
conf_set_changed(true);
@ -1146,23 +1132,3 @@ void conf_set_changed_callback(void (*fn)(bool))
{
conf_changed_callback = fn;
}
void set_all_choice_values(struct symbol *csym)
{
struct property *prop;
struct symbol *sym;
struct expr *e;
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 | SYMBOL_NEED_SET_CHOICE_VALUES);
}

12
scripts/kconfig/expr.h
View File

@ -73,6 +73,8 @@ enum {
* Represents a configuration symbol.
*
* Choices are represented as a special kind of symbol with null name.
*
* @choice_link: linked to menu::choice_members
*/
struct symbol {
/* link node for the hash table */
@ -110,6 +112,8 @@ struct symbol {
/* config entries associated with this symbol */
struct list_head menus;
struct list_head choice_link;
/* SYMBOL_* flags */
int flags;
@ -133,7 +137,6 @@ struct symbol {
#define SYMBOL_CHOICEVAL 0x0020 /* used as a value in a choice block */
#define SYMBOL_VALID 0x0080 /* set when symbol.curr is calculated */
#define SYMBOL_WRITE 0x0200 /* write symbol to file (KCONFIG_CONFIG) */
#define SYMBOL_CHANGED 0x0400 /* ? */
#define SYMBOL_WRITTEN 0x0800 /* track info to avoid double-write to .config */
#define SYMBOL_CHECKED 0x2000 /* used during dependency checking */
#define SYMBOL_WARNED 0x8000 /* warning has been issued */
@ -145,9 +148,6 @@ struct symbol {
#define SYMBOL_DEF3 0x40000 /* symbol.def[S_DEF_3] is valid */
#define SYMBOL_DEF4 0x80000 /* symbol.def[S_DEF_4] is valid */
/* choice values need to be set before calculating this symbol value */
#define SYMBOL_NEED_SET_CHOICE_VALUES 0x100000
#define SYMBOL_MAXLENGTH 256
/* A property represent the config options that can be associated
@ -204,6 +204,8 @@ struct property {
* for all front ends). Each symbol, menu, etc. defined in the Kconfig files
* gets a node. A symbol defined in multiple locations gets one node at each
* location.
*
* @choice_members: list of choice members with priority.
*/
struct menu {
/* The next menu node at the same level */
@ -223,6 +225,8 @@ struct menu {
struct list_head link; /* link to symbol::menus */
struct list_head choice_members;
/*
* The prompt associated with the node. This holds the prompt for a
* symbol as well as the text for a menu or comment, along with the

7
scripts/kconfig/lkc.h
View File

@ -40,7 +40,6 @@ void zconf_nextfile(const char *name);
/* confdata.c */
extern struct gstr autoconf_cmd;
const char *conf_get_configname(void);
void set_all_choice_values(struct symbol *csym);
/* confdata.c and expr.c */
static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out)
@ -121,11 +120,7 @@ static inline tristate sym_get_tristate_value(struct symbol *sym)
return sym->curr.tri;
}
static inline struct symbol *sym_get_choice_value(struct symbol *sym)
{
return (struct symbol *)sym->curr.val;
}
struct symbol *sym_get_choice_value(struct symbol *sym);
static inline bool sym_is_choice(struct symbol *sym)
{

17
scripts/kconfig/menu.c
View File

@ -591,7 +591,6 @@ bool menu_is_empty(struct menu *menu)
bool menu_is_visible(struct menu *menu)
{
struct menu *child;
struct symbol *sym;
tristate visible;
@ -610,21 +609,7 @@ bool menu_is_visible(struct menu *menu)
} else
visible = menu->prompt->visible.tri = expr_calc_value(menu->prompt->visible.expr);
if (visible != no)
return true;
if (!sym || sym_get_tristate_value(menu->sym) == no)
return false;
for (child = menu->list; child; child = child->next) {
if (menu_is_visible(child)) {
if (sym)
sym->flags |= SYMBOL_DEF_USER;
return true;
}
}
return false;
return visible != no;
}
const char *menu_get_prompt(struct menu *menu)

4
scripts/kconfig/parser.y
View File

@ -157,6 +157,9 @@ config_stmt: config_entry_start config_option_list
current_entry->filename, current_entry->lineno);
yynerrs++;
}
list_add_tail(&current_entry->sym->choice_link,
&current_choice->choice_members);
}
printd(DEBUG_PARSE, "%s:%d:endconfig\n", cur_filename, cur_lineno);
@ -240,6 +243,7 @@ choice: T_CHOICE T_EOL
menu_add_entry(sym);
menu_add_expr(P_CHOICE, NULL, NULL);
menu_set_type(S_BOOLEAN);
INIT_LIST_HEAD(&current_entry->choice_members);
printd(DEBUG_PARSE, "%s:%d:choice\n", cur_filename, cur_lineno);
};

159
scripts/kconfig/symbol.c
View File

@ -188,7 +188,6 @@ static void sym_set_changed(struct symbol *sym)
{
struct menu *menu;
sym->flags |= SYMBOL_CHANGED;
list_for_each_entry(menu, &sym->menus, link)
menu->flags |= MENU_CHANGED;
}
@ -282,36 +281,95 @@ struct symbol *sym_choice_default(struct symbol *sym)
return NULL;
}
static struct symbol *sym_calc_choice(struct symbol *sym)
/*
* sym_calc_choice - calculate symbol values in a choice
*
* @choice: a menu of the choice
*
* Return: a chosen symbol
*/
static struct symbol *sym_calc_choice(struct menu *choice)
{
struct symbol *def_sym;
struct property *prop;
struct expr *e;
int flags;
struct symbol *res = NULL;
struct symbol *sym;
struct menu *menu;
/* first calculate all choice values' visibilities */
flags = sym->flags;
prop = sym_get_choice_prop(sym);
expr_list_for_each_sym(prop->expr, e, def_sym) {
sym_calc_visibility(def_sym);
if (def_sym->visible != no)
flags &= def_sym->flags;
/* Traverse the list of choice members in the priority order. */
list_for_each_entry(sym, &choice->choice_members, choice_link) {
sym_calc_visibility(sym);
if (sym->visible == no)
continue;
/* The first visible symble with the user value 'y'. */
if (sym_has_value(sym) && sym->def[S_DEF_USER].tri == yes) {
res = sym;
break;
}
}
sym->flags &= flags | ~SYMBOL_DEF_USER;
/*
* If 'y' is not found in the user input, use the default, unless it is
* explicitly set to 'n'.
*/
if (!res) {
res = sym_choice_default(choice->sym);
if (res && sym_has_value(res) && res->def[S_DEF_USER].tri == no)
res = NULL;
}
/* is the user choice visible? */
def_sym = sym->def[S_DEF_USER].val;
if (def_sym && def_sym->visible != no)
return def_sym;
/* Still not found. Pick up the first visible, user-unspecified symbol. */
if (!res) {
menu_for_each_sub_entry(menu, choice) {
sym = menu->sym;
def_sym = sym_choice_default(sym);
if (!sym || sym->visible == no || sym_has_value(sym))
continue;
if (def_sym == NULL)
/* no choice? reset tristate value */
sym->curr.tri = no;
res = sym;
break;
}
}
return def_sym;
/*
* Still not found. Traverse the linked list in the _reverse_ order to
* pick up the least prioritized 'n'.
*/
if (!res) {
list_for_each_entry_reverse(sym, &choice->choice_members,
choice_link) {
if (sym->visible == no)
continue;
res = sym;
break;
}
}
menu_for_each_sub_entry(menu, choice) {
tristate val;
sym = menu->sym;
if (!sym || sym->visible == no)
continue;
val = sym == res ? yes : no;
if (sym->curr.tri != val)
sym_set_changed(sym);
sym->curr.tri = val;
sym->flags |= SYMBOL_VALID | SYMBOL_WRITE;
}
return res;
}
struct symbol *sym_get_choice_value(struct symbol *sym)
{
struct menu *menu = list_first_entry(&sym->menus, struct menu, link);
return sym_calc_choice(menu);
}
static void sym_warn_unmet_dep(struct symbol *sym)
@ -347,7 +405,7 @@ void sym_calc_value(struct symbol *sym)
{
struct symbol_value newval, oldval;
struct property *prop;
struct expr *e;
struct menu *choice_menu;
if (!sym)
return;
@ -355,13 +413,6 @@ void sym_calc_value(struct symbol *sym)
if (sym->flags & SYMBOL_VALID)
return;
if (sym_is_choice_value(sym) &&
sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
prop = sym_get_choice_prop(sym);
sym_calc_value(prop_get_symbol(prop));
}
sym->flags |= SYMBOL_VALID;
oldval = sym->curr;
@ -400,9 +451,11 @@ void sym_calc_value(struct symbol *sym)
switch (sym_get_type(sym)) {
case S_BOOLEAN:
case S_TRISTATE:
if (sym_is_choice_value(sym) && sym->visible == yes) {
prop = sym_get_choice_prop(sym);
newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
choice_menu = sym_get_choice_menu(sym);
if (choice_menu) {
sym_calc_choice(choice_menu);
newval.tri = sym->curr.tri;
} else {
if (sym->visible != no) {
/* if the symbol is visible use the user value
@ -461,8 +514,6 @@ void sym_calc_value(struct symbol *sym)
}
sym->curr = newval;
if (sym_is_choice(sym) && newval.tri == yes)
sym->curr.val = sym_calc_choice(sym);
sym_validate_range(sym);
if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
@ -473,23 +524,8 @@ void sym_calc_value(struct symbol *sym)
}
}
if (sym_is_choice(sym)) {
struct symbol *choice_sym;
prop = sym_get_choice_prop(sym);
expr_list_for_each_sym(prop->expr, e, choice_sym) {
if ((sym->flags & SYMBOL_WRITE) &&
choice_sym->visible != no)
choice_sym->flags |= SYMBOL_WRITE;
if (sym->flags & SYMBOL_CHANGED)
sym_set_changed(choice_sym);
}
if (sym_is_choice(sym))
sym->flags &= ~SYMBOL_WRITE;
}
if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
set_all_choice_values(sym);
}
void sym_clear_all_valid(void)
@ -523,15 +559,15 @@ bool sym_set_tristate_value(struct symbol *sym, tristate val)
{
tristate oldval = sym_get_tristate_value(sym);
if (oldval != val && !sym_tristate_within_range(sym, val))
if (!sym_tristate_within_range(sym, val))
return false;
if (!(sym->flags & SYMBOL_DEF_USER)) {
if (!(sym->flags & SYMBOL_DEF_USER) || sym->def[S_DEF_USER].tri != val) {
sym->def[S_DEF_USER].tri = val;
sym->flags |= SYMBOL_DEF_USER;
sym_set_changed(sym);
}
sym->def[S_DEF_USER].tri = val;
if (oldval != val)
sym_clear_all_valid();
@ -565,10 +601,17 @@ void choice_set_value(struct menu *choice, struct symbol *sym)
menu->sym->def[S_DEF_USER].tri = val;
menu->sym->flags |= SYMBOL_DEF_USER;
}
choice->sym->def[S_DEF_USER].val = sym;
choice->sym->flags |= SYMBOL_DEF_USER;
/*
* Now, the user has explicitly enabled or disabled this symbol,
* it should be given the highest priority. We are possibly
* setting multiple symbols to 'n', where the first symbol is
* given the least prioritized 'n'. This works well when the
* choice block ends up with selecting 'n' symbol.
* (see sym_calc_choice())
*/
list_move(&menu->sym->choice_link, &choice->choice_members);
}
if (changed)
sym_clear_all_valid();