Most 'make *config' commands use .config as the base configuration file.
When .config does not exist, Kconfig tries to load a file listed in
KCONFIG_DEFCONFIG_LIST instead.
However, since commit b75b0a819a ("kconfig: change defconfig_list
option to environment variable"), warning messages have displayed an
incorrect file name in such cases.
Below is a demonstration using Debian Trixie. While loading
/boot/config-6.12.9-amd64, the warning messages incorrectly show .config
as the file name.
With this commit, the correct file name is displayed in warnings.
[Before]
$ rm -f .config
$ make config
#
# using defaults found in /boot/config-6.12.9-amd64
#
.config:6804:warning: symbol value 'm' invalid for FB_BACKLIGHT
.config:9895:warning: symbol value 'm' invalid for ANDROID_BINDER_IPC
[After]
$ rm -f .config
$ make config
#
# using defaults found in /boot/config-6.12.9-amd64
#
/boot/config-6.12.9-amd64:6804:warning: symbol value 'm' invalid for FB_BACKLIGHT
/boot/config-6.12.9-amd64:9895:warning: symbol value 'm' invalid for ANDROID_BINDER_IPC
Fixes: b75b0a819a ("kconfig: change defconfig_list option to environment variable")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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>
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>
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>
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>
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>
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>
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>
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>
Use helper macros in hashtable.h for generic hashtable implementation.
We can git rid of the hash head index of for_all_symbols().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This allows preprocess.c to free up all of its resources when the parse
stage is finished. It also ensures conf_write_autoconf_cmd() produces
consistent results even if called multiple times for any reason.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, include/config/autoconf.cmd saves included Kconfig files in
reverse order. While this is not a big deal, it is inconsistent with
other *.cmd files generated by fixdep.
Output the included Kconfig files in the included order.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When KCONFIG_WERROR env variable is set treat unmet direct
symbol dependency as a terminal condition (error).
Suggested-by: Stefan Reinauer <reinauer@google.com>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Make the while-loop code a little more readable.
The gain is that "CONFIG_FOO" without '=' is warned as unexpected data.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, any string starting "is not set" disables a CONFIG option.
For example, "# CONFIG_FOO is not settled down" is accepted as valid
input, functioning the same as "# CONFIG_FOO is not set". It is a
long-standing oddity.
Check the line against the exact pattern "is not set".
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, newline characters are stripped away in multiple places
on the caller.
Doing that in the callee is helpful for further cleanups.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
