kconfig: Document the 'symbol' struct

Visibility and choices in particular might be a bit tricky to figure
out.

Also fix existing comment to point out that P_MENU is also used for
menus.

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Ulf Magnusson 2017-10-04 07:48:14 +02:00 committed by Masahiro Yamada
parent 33ca1a2486
commit 52aede4ba5
1 changed files with 44 additions and 1 deletions

View File

@ -74,17 +74,60 @@ enum {
S_DEF_COUNT
};
/*
* Represents a configuration symbol.
*
* Choices are represented as a special kind of symbol and have the
* SYMBOL_CHOICE bit set in 'flags'.
*/
struct symbol {
/* The next symbol in the same bucket in the symbol hash table */
struct symbol *next;
/* The name of the symbol, e.g. "FOO" for 'config FOO' */
char *name;
/* S_BOOLEAN, S_TRISTATE, ... */
enum symbol_type type;
/*
* The calculated value of the symbol. The SYMBOL_VALID bit is set in
* 'flags' when this is up to date. Note that this value might differ
* from the user value set in e.g. a .config file, due to visibility.
*/
struct symbol_value curr;
/*
* Values for the symbol provided from outside. def[S_DEF_USER] holds
* the .config value.
*/
struct symbol_value def[S_DEF_COUNT];
/*
* An upper bound on the tristate value the user can set for the symbol
* if it is a boolean or tristate. Calculated from prompt dependencies,
* which also inherit dependencies from enclosing menus, choices, and
* ifs. If 'n', the user value will be ignored.
*
* Symbols lacking prompts always have visibility 'n'.
*/
tristate visible;
/* SYMBOL_* flags */
int flags;
/* List of properties. See prop_type. */
struct property *prop;
/* Dependencies from enclosing menus, choices, and ifs */
struct expr_value dir_dep;
/* Reverse dependencies through being selected by other symbols */
struct expr_value rev_dep;
/*
* "Weak" reverse dependencies through being implied by other symbols
*/
struct expr_value implied;
};
@ -133,7 +176,7 @@ enum prop_type {
P_UNKNOWN,
P_PROMPT, /* prompt "foo prompt" or "BAZ Value" */
P_COMMENT, /* text associated with a comment */
P_MENU, /* prompt associated with a menuconfig option */
P_MENU, /* prompt associated with a menu or menuconfig symbol */
P_DEFAULT, /* default y */
P_CHOICE, /* choice value */
P_SELECT, /* select BAR */