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>
Currently, sym_set_tristate_value() is used to set 'y' to a choice
member, which is confusing because it not only sets 'y' to the given
symbol but also tweaks flags of other symbols as a side effect.
Add a dedicated function for setting the value of the given choice.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The condition (t2 == 0) never becomes true because the zero value
(i.e., E_NONE) is only used as a dummy type for prevtoken. It can
be passed to t1, but not to t2.
The caller of this function only checks expr_compare_type() > 0.
Therefore, the distinction between 0 and -1 is unnecessary.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Set -e to make these scripts fail on the first error.
Set -u because these scripts are invoked by Makefile, and do not work
properly without necessary variables defined.
Both options are described in POSIX. [1]
[1]: https://pubs.opengroup.org/onlinepubs/009604499/utilities/set.html
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reduce the indentation level by continue'ing the loop earlier
if (!sym || sym_is_choice(sym)).
No functional change intended.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
The outer switch statement can be avoided by continue'ing earlier the
loop when the symbol type is neither S_BOOLEAN nor S_TRISTATE.
Remove it to reduce the indentation level by one. In addition, avoid
the repetition of sym->def[S_DEF_USER].tri.
No functional change intended.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
I previously submitted a fix for a bug in the choice feature [1], where
I mentioned, "Another (much cleaner) approach would be to remove the
tristate choice support entirely".
There are more issues in the tristate choice feature. For example, you
can observe a couple of bugs in the following test code.
[Test Code]
config MODULES
def_bool y
modules
choice
prompt "tristate choice"
default A
config A
tristate "A"
config B
tristate "B"
endchoice
Bug 1: the 'default' property is not correctly processed
'make alldefconfig' produces:
CONFIG_MODULES=y
# CONFIG_A is not set
# CONFIG_B is not set
However, the correct output should be:
CONFIG_MODULES=y
CONFIG_A=y
# CONFIG_B is not set
The unit test file, scripts/kconfig/tests/choice/alldef_expected_config,
is wrong as well.
Bug 2: choice members never get 'y' with randconfig
For the test code above, the following combinations are possible:
A B
(1) y n
(2) n y
(3) m m
(4) m n
(5) n m
(6) n n
'make randconfig' never produces (1) or (2).
These bugs are fixable, but a more critical problem is the lack of a
sensible syntax to specify the default for the tristate choice.
The default for the choice must be one of the choice members, which
cannot specify any of the patterns (3) through (6) above.
In addition, I have never seen it being used in a useful way.
The following commits removed unnecessary use of tristate choices:
- df8df5e4bc ("usb: get rid of 'choice' for legacy gadget drivers")
- bfb57ef054 ("rapidio: remove choice for enumeration")
This commit removes the tristate choice support entirely, which allows
me to delete a lot of code, making further refactoring easier.
Note:
This includes the revert of commit fa64e5f6a3 ("kconfig/symbol.c:
handle choice_values that depend on 'm' symbols"). It was suspicious
because it did not address the root cause but introduced inconsistency
in visibility between choice members and other symbols.
[1]: https://lore.kernel.org/linux-kbuild/20240427104231.2728905-1-masahiroy@kernel.org/T/#m0a1bb6992581462ceca861b409bb33cb8fd7dbae
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Commit ee06a3ef7e ("kconfig: Update config changed flag before calling
callback") pointed out that conf_updated flag must be updated _before_
calling the callback, which needs to know the new value.
Given that, it makes sense to directly pass the new value to the
callback.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
If any CONFIG option is changed while loading the .config file,
conf_read() calls conf_set_changed(true) and then the conf_changed()
callback.
With conf_read() moved after window initialization, the explicit
conf_changed() call can be removed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
expr_trans_bool() performs an incorrect transformation.
[Test Code]
config MODULES
def_bool y
modules
config A
def_bool y
select C if B != n
config B
def_tristate m
config C
tristate
[Result]
CONFIG_MODULES=y
CONFIG_A=y
CONFIG_B=m
CONFIG_C=m
This output is incorrect because CONFIG_C=y is expected.
Documentation/kbuild/kconfig-language.rst clearly explains the function
of the '!=' operator:
If the values of both symbols are equal, it returns 'n',
otherwise 'y'.
Therefore, the statement:
select C if B != n
should be equivalent to:
select C if y
Or, more simply:
select C
Hence, the symbol C should be selected by the value of A, which is 'y'.
However, expr_trans_bool() wrongly transforms it to:
select C if B
Therefore, the symbol C is selected by (A && B), which is 'm'.
The comment block of expr_trans_bool() correctly explains its intention:
* bool FOO!=n => FOO
^^^^
If FOO is bool, FOO!=n can be simplified into FOO. This is correct.
However, the actual code performs this transformation when FOO is
tristate:
if (e->left.sym->type == S_TRISTATE) {
^^^^^^^^^^
While it can be fixed to S_BOOLEAN, there is no point in doing so
because expr_tranform() already transforms FOO!=n to FOO when FOO is
bool. (see the "case E_UNEQUAL" part)
expr_trans_bool() is wrong and unnecessary.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Currently, the initial state of the "Save" button is always active.
If none of the CONFIG options are changed while loading the .config
file, the "Save" button should be greyed out.
This can be fixed by calling conf_read() after widget initialization.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This is a leftover from commit ce1fc9345a ("kconfig: do not clear
SYMBOL_DEF_USER when the value is out of range").
This code is now redundant because if a user-supplied value is out
of range, the value adjusted by sym_validate_range() differs, and
conf_unsaved has already been incremented a few lines above.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The check for 'sym1 == sym2' is redundant here because it has already
been done a few lines above:
if (sym1 != sym2)
return NULL;
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, comparisons to 'm' or 'n' result in incorrect output.
[Test Code]
config MODULES
def_bool y
modules
config A
def_tristate m
config B
def_bool A > n
CONFIG_B is unset, while CONFIG_B=y is expected.
The reason for the issue is because Kconfig compares the tristate values
as strings.
Currently, the .type fields in the constant symbol definitions,
symbol_{yes,mod,no} are unspecified, i.e., S_UNKNOWN.
When expr_calc_value() evaluates 'A > n', it checks the types of 'A' and
'n' to determine how to compare them.
The left-hand side, 'A', is a tristate symbol with a value of 'm', which
corresponds to a numeric value of 1. (Internally, 'y', 'm', and 'n' are
represented as 2, 1, and 0, respectively.)
The right-hand side, 'n', has an unknown type, so it is treated as the
string "n" during the comparison.
expr_calc_value() compares two values numerically only when both can
have numeric values. Otherwise, they are compared as strings.
symbol numeric value ASCII code
-------------------------------------
y 2 0x79
m 1 0x6d
n 0 0x6e
'm' is greater than 'n' if compared numerically (since 1 is greater
than 0), but smaller than 'n' if compared as strings (since the ASCII
code 0x6d is smaller than 0x6e).
Specifying .type=S_TRISTATE for symbol_{yes,mod,no} fixes the above
test code.
Doing so, however, would cause a regression to the following test code.
[Test Code 2]
config MODULES
def_bool n
modules
config A
def_tristate n
config B
def_bool A = m
You would get CONFIG_B=y, while CONFIG_B should not be set.
The reason is because sym_get_string_value() turns 'm' into 'n' when the
module feature is disabled. Consequently, expr_calc_value() evaluates
'A = n' instead of 'A = m'. This oddity has been hidden because the type
of 'm' was previously S_UNKNOWN instead of S_TRISTATE.
sym_get_string_value() should not tweak the string because the tristate
value has already been correctly calculated. There is no reason to
return the string "n" where its tristate value is mod.
Fixes: 31847b67be ("kconfig: allow use of relations other than (in)equality")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This has not been used since commit e911503085 ("Kconfig: Remove
bad inference rules expr_eliminate_dups2()").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Choices and their members are associated via the P_CHOICE property.
Currently, prop_get_symbol(sym_get_choice_prop()) is used to obtain
the choice of the given choice member.
Replace it with sym_get_choice_menu(), which retrieves the choice
without relying on P_CHOICE.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Previously, optional bool choices met the following conditions
simultaneously:
- sym_is_choice(sym)
- sym_is_changeable(sym)
- type == S_BOOLEAN
It no longer occurs since 6a1215888e ("kconfig: remove 'optional'
property support"). Remove the dead code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This code previously displayed child symbols of the selected choice
member.
Since commit 7e3465f63a ("kconfig: do not reparent the menu inside
a choice block"), choice members never have child symbols, therefore
this is dead code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, bool choices have a checkbox, but tristate choices do not.
It is opposite.
Bool choices should not have a checkbox, as they are fixed to 'y' since
commit 6a1215888e ("kconfig: remove 'optional' property support").
Tristate choices, however, should have a checkbox to allow users to
toggle the value.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Choices and their members are associated via the P_CHOICE property.
Currently, sym_get_choice_prop() and expr_list_for_each_sym() are
used to iterate on choice members.
Replace them with menu_for_each_sub_entry(), which achieves the same
without relying on P_CHOICE.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Choices and their members are associated via the P_CHOICE property.
Currently, prop_get_symbol(sym_get_choice_prop()) is used to obtain
the choice of the given choice member.
Replace it with sym_get_choice_menu(), which retrieves the choice
without relying on P_CHOICE.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Choices and their members are associated via the P_CHOICE property.
Currently, prop_get_symbol(sym_get_choice_prop()) is used to obtain
the choice of the given choice member.
We can do this without relying on P_CHOICE by checking the parent in
the menu structure.
Introduce a new helper to retrieve the choice if the given symbol is a
choice member.
This is intended to replace prop_get_symbol(sym_get_choice_prop()) and
deprecate P_CHOICE eventually.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
menu_finalize() warns default properties for choice members and prompts
outside the choice block. These should be hard errors.
While I was here, I moved the checks to slim down menu_finalize().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Choice members must have a prompt; hence make it an error.
While I was here, I moved the check to the parser to slim down
_menu_finalize().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Following the approach employed in commit bedf923623 ("kconfig: use
linked list in get_symbol_str() to iterate over menus"), simplify the
iteration on the menus of the specified symbol.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
SYMBOL_CHANGED and MENU_CHANGED are used to update GUI frontends
when the symbol value is changed. These are used inconsistently:
SYMBOL_CHANGED in gconf.c and MENU_CHANGE in qconf.cc.
MENU_CHANGED works more properly when a symbol has multiple prompts
(although such code is not ideal).
[test code]
config FOO
bool "foo prompt 1"
config FOO
bool "foo prompt 2"
In gconfig, if one of the two checkboxes is clicked, only the first
one is toggled. In xconfig, the two checkboxes work in sync.
Replace SYMBOL_CHANGED in gconf.c with MENU_CHANGED to align with
the xconfig behavior.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Every time a config file is loaded (either by clicking the "Load" button
or selecting "File" -> "Load" from the menu), a new list is appended to
the pane.
The current tree needs to be cleared by calling gtk_tree_store_clear().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:
src := $(obj)
When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.
This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.
To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.
Going forward, the variables used in Makefiles will have the following
meanings:
$(obj) - directory in the object tree
$(src) - directory in the source tree (changed by this commit)
$(objtree) - the top of the kernel object tree
$(srctree) - the top of the kernel source tree
Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
This flag is set to symbols that are not intended to be written
to the .config file.
Since commit b75b0a819a ("kconfig: change defconfig_list option to
environment variable"), SYMBOL_NO_WRITE is only set to choices.
Therefore, (sym->flags & SYMBOL_NO_WRITE) is equivalent to
sym_is_choice(sym). This flag is no longer necessary.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The 'choice' statement is primarily used to exclusively select one
option, but the 'optional' property allows all entries to be disabled.
In the following example, both A and B can be disabled simultaneously:
choice
prompt "choose A, B, or nothing"
optional
config A
bool "A"
config B
bool "B"
endchoice
You can achieve the equivalent outcome by other means.
A common solution is to add another option to guard the choice block.
In the following example, you can set ENABLE_A_B_CHOICE=n to disable
the entire choice block:
choice
prompt "choose A or B"
depends on ENABLE_A_B_CHOICE
config A
bool "A"
config B
bool "B"
endchoice
Another approach is to insert one more entry:
choice
prompt "choose A, B, or disable both"
config A
bool "A"
config B
bool "B"
config DISABLE_A_AND_B
bool "choose this to disable both A and B"
endchoice
Some real examples are DEBUG_INFO_NONE, INITRAMFS_COMPRESSION_NONE,
LTO_NONE, etc.
The 'optional' property is even more unnecessary for a tristate choice.
Without the 'optional' property, you can disable A and B; you can set
'm' in the choice prompt, and disable A and B individually:
choice
prompt "choose one built-in or make them modular"
config A
tristate "A"
config B
tristate "B"
endchoice
In conclusion, the 'optional' property was unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
All symbols except choices have a name.
Previously, choices were allowed to have a name, but commit c83f020973
("kconfig: remove named choice support") eliminated that possibility.
Now, it is easy to distinguish choices from normal symbols; if the name
is NULL, it is a choice.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
All symbols except choices have a name.
child->sym->name never becomes NULL inside choice blocks.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Use menu_for_each_entry() to traverse the menu tree instead of
implementing similar logic in each function.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Several functions require traversing menu entries sequentially. This
commit introduces some helpers to simplify such operations.
The menu_next() function facilitates depth-first traversal:
1. Descend to the child level if the current menu has one
2. Move to the next sibling at the same level if available
3. Ascend to the parent level if there is no more child or sibling
The menu_for_each_sub_entry() macro iterates over all submenu entries
using depth-first traverse.
The menu_for_each_entry() macro is the same, but over all menu entries.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Fixed a typo in some variables where height was misspelled as heigth.
Signed-off-by: Isak Ellmer <isak01@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The boolean 'choice' is used to list exclusively selected config
options.
You must not add a dependency between choice members, because such a
dependency would create an invisible entry.
In the following test case, it is impossible to choose 'C'.
[Test Case 1]
choice
prompt "Choose one, but how to choose C?"
config A
bool "A"
config B
bool "B"
config C
bool "C"
depends on A
endchoice
Hence, Kconfig shows the following error message:
Kconfig:1:error: recursive dependency detected!
Kconfig:1: choice <choice> contains symbol C
Kconfig:10: symbol C is part of choice A
Kconfig:4: symbol A is part of choice <choice>
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"
However, Kconfig does not report anything for the following similar code:
[Test Case 2]
choice
prompt "Choose one, but how to choose B?"
config A
bool "A"
config B
bool "B"
depends on A
config C
bool "C"
endchoice
This is because menu_finalize() reparents the menu tree when an entry
depends on the preceding one.
With reparenting, the menu tree:
choice
|- A
|- B
\- C
... will be transformed into the following structure:
choice
|- A
| \- B
\- C
Consequently, Kconfig considers only 'A' and 'C' as choice members.
This behavior is awkward. The second test case should be an error too.
This commit stops reparenting inside a choice.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit c8fb7d7e48 ("kconfig: fix broken dependency in randconfig-
generated .config") fixed the issue, but I did not add a test case.
This commit adds a test case that emulates the reported situation.
The test would fail without c8fb7d7e48.
To handle the choice "choose X", FOO must be calculated beforehand.
FOO depends on A, which is a member of another choice "choose A or B".
Kconfig _temporarily_ assumes the value of A to proceed. The choice
"choose A or B" will be shuffled later, but the result may or may not
meet "FOO depends on A". Kconfig should invalidate the symbol values
and recompute them.
In the real example for ARCH=arm64, the choice "Instrumentation type"
needs the value of CPU_BIG_ENDIAN. The choice "Endianness" will be
shuffled later.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit 3b9a19e089 ("kconfig: loop as long as we changed some
symbols in randconfig"), conf_set_all_new_symbols() is repeated until
there is no more choice left to be shuffled. The motivation was to
shuffle a choice nested in another choice.
Although commit 09d5873e4d ("kconfig: allow only 'config', 'comment',
and 'if' inside 'choice'") disallowed the nested choice structure,
we must still keep 3b9a19e089 because there are still cases where
conf_set_all_new_symbols() must iterate.
scripts/kconfig/tests/choice_randomize/Kconfig is the test case.
The second choice depends on 'B', which is the member of the first
choice.
With 3b9a19e089 reverted, we would never get the pattern specified by
scripts/kconfig/tests/choice_randomize/expected_config2.
A real example can be found in lib/Kconfig.debug. Without 3b9a19e089,
the randconfig would not shuffle the "Compressed Debug information"
choice, which depends on DEBUG_INFO, which is derived from another
choice "Debug information".
My goal is to refactor Kconfig so that randconfig will work more
simply, without using the loop.
For now, let's add a test case to ensure all dependent choices are
shuffled, as it is a somewhat tricky case for the current Kconfig.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When the condition 'sym == NULL' is met, the code will reach the
'next_menu' label regardless of the return value from menu_is_visible().
menu_is_visible() calculates some symbol values as a side-effect, for
instance by calling expr_calc_value(menu->visibility), but all the
symbol values will be calculated eventually.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>