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Commit Graph

1255 Commits

Author SHA1 Message Date
Masahiro Yamada
d01661e1f4 kconfig: show sub-menu entries even if the prompt is hidden
Since commit f79dc03fe6 ("kconfig: refactor choice value
calculation"), when EXPERT is disabled, nothing within the "if INPUT"
... "endif" block in drivers/input/Kconfig is displayed. This issue
affects all command-line interfaces and GUI frontends.

The prompt for INPUT is hidden when EXPERT is disabled. Previously,
menu_is_visible() returned true in this case; however, it now returns
false, resulting in all sub-menu entries being skipped.

Here is a simplified test case illustrating the issue:

    config A
           bool "A" if X
           default y

    config B
           bool "B"
           depends on A

When X is disabled, A becomes unconfigurable and is forced to y.
B should be displayed, as its dependency is met.

This commit restores the necessary code, so menu_is_visible() functions
as it did previously.

Fixes: f79dc03fe6 ("kconfig: refactor choice value calculation")
Reported-by: Edmund Raile <edmund.raile@proton.me>
Closes: https://lore.kernel.org/all/5fd0dfc7ff171aa74352e638c276069a5f2e888d.camel@proton.me/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-10-31 21:42:20 +09:00
Masahiro Yamada
984ed20ece kconfig: qconf: fix buffer overflow in debug links
If you enable "Option -> Show Debug Info" and click a link, the program
terminates with the following error:

    *** buffer overflow detected ***: terminated

The buffer overflow is caused by the following line:

    strcat(data, "$");

The buffer needs one more byte to accommodate the additional character.

Fixes: c4f7398bee ("kconfig: qconf: make debug links work again")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-10-02 16:02:40 +09:00
Masahiro Yamada
da724c33b6 kconfig: qconf: move conf_read() before drawing tree pain
The constructor of ConfigMainWindow() calls show*View(), which needs
to calculate symbol values. conf_read() must be called before that.

Fixes: 060e05c3b4 ("kconfig: qconf: remove initial call to conf_changed()")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-10-01 17:05:34 +09:00
Masahiro Yamada
8d095547de kconfig: clear expr::val_is_valid when allocated
Since commit 95573cac25 ("kconfig: cache expression values"), xconfig
emits a lot of false-positive "unmet direct dependencies" warnings.

While conf_read() clears val_is_valid flags, 'make xconfig' calculates
symbol values even before the conf_read() call. This is another issue
that should be addressed separately, but it has revealed that the
val_is_valid field is not initialized.

Fixes: 95573cac25 ("kconfig: cache expression values")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-10-01 17:05:30 +09:00
Masahiro Yamada
4d46b5b623 kconfig: fix infinite loop in sym_calc_choice()
Since commit f79dc03fe6 ("kconfig: refactor choice value calculation"),
Kconfig for ARCH=powerpc may result in an infinite loop. This occurs
because there are two entries for POWERPC64_CPU in a choice block.

If the same symbol appears twice in a choice block, the ->choice_link
node is added twice to ->choice_members, resulting a corrupted linked
list.

A simple test case is:

    choice
            prompt "choice"

    config A
            bool "A"

    config B
            bool "B 1"

    config B
            bool "B 2"

    endchoice

Running 'make defconfig' results in an infinite loop.

One solution is to replace the current two entries:

    config POWERPC64_CPU
            bool "Generic (POWER5 and PowerPC 970 and above)"
            depends on PPC_BOOK3S_64 && !CPU_LITTLE_ENDIAN
            select PPC_64S_HASH_MMU

    config POWERPC64_CPU
            bool "Generic (POWER8 and above)"
            depends on PPC_BOOK3S_64 && CPU_LITTLE_ENDIAN
            select ARCH_HAS_FAST_MULTIPLIER
            select PPC_64S_HASH_MMU
            select PPC_HAS_LBARX_LHARX

with the following single entry:

    config POWERPC64_CPU
            bool "Generic 64 bit powerpc"
            depends on PPC_BOOK3S_64
            select ARCH_HAS_FAST_MULTIPLIER if CPU_LITTLE_ENDIAN
            select PPC_64S_HASH_MMU
            select PPC_HAS_LBARX_LHARX if CPU_LITTLE_ENDIAN

In my opinion, the latter looks cleaner, but PowerPC maintainers may
prefer to display different prompts depending on CPU_LITTLE_ENDIAN.

For now, this commit fixes the issue in Kconfig, restoring the original
behavior. I will reconsider whether such a use case is worth supporting.

Fixes: f79dc03fe6 ("kconfig: refactor choice value calculation")
Reported-by: Marco Bonelli <marco@mebeim.net>
Closes: https://lore.kernel.org/all/1763151587.3581913.1727224126288@privateemail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-30 20:42:52 +09:00
Masahiro Yamada
95573cac25 kconfig: cache expression values
Cache expression values to avoid recalculating them repeatedly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:53 +09:00
Masahiro Yamada
f93d6bfbd2 kconfig: use hash table to reuse expressions
Currently, every expression in Kconfig files produces a new abstract
syntax tree (AST), even if it is identical to a previously encountered
one.

Consider the following code:

    config FOO
           bool "FOO"
           depends on (A || B) && C

    config BAR
           bool "BAR"
           depends on (A || B) && C

    config BAZ
           bool "BAZ"
           depends on A || B

The "depends on" lines are similar, but currently a separate AST is
allocated for each one.

The current data structure looks like this:

  FOO->dep ==> AND        BAR->dep ==> AND        BAZ->dep ==> OR
              /   \                   /   \                   /  \
            OR     C                OR     C                 A    B
           /  \                    /  \
          A    B                  A    B

This is redundant; FOO->dep and BAR->dep have identical ASTs but
different memory instances.

We can optimize this; FOO->dep and BAR->dep can share the same AST, and
BAZ->dep can reference its sub tree.

The optimized data structure looks like this:

  FOO->dep, BAR->dep ==> AND
                        /   \
         BAZ->dep ==> OR     C
                     /  \
                    A    B

This commit introduces a hash table to keep track of allocated
expressions. If an identical expression is found, it is reused.

This does not necessarily result in memory savings, as menu_finalize()
transforms expressions without freeing up stale ones. This will be
addressed later.

One optimization that can be easily implemented is caching the
expression's value. Once FOO's dependency, (A || B) && C, is calculated,
it can be cached, eliminating the need to recalculate it for BAR.

This commit also reverts commit e983b7b17a ("kconfig/menu.c: fix
multiple references to expressions in menu_add_prop()").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:52 +09:00
Masahiro Yamada
440f67ccdc kconfig: refactor expr_eliminate_dups()
Currently, expr_eliminate_dups() passes two identical pointers down to
expr_eliminate_dups1(), which later skips processing identical leaves.

This approach is somewhat tricky and, more importantly, it will not work
with the refactoring made in the next commit.

This commit slightly changes the recursion logic; it deduplicates both
the left and right arms, and then passes them to expr_eliminate_dups1().
expr_eliminate_dups() should produce the same result.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:52 +09:00
Masahiro Yamada
4fa146eaec kconfig: add comments to expression transformations
Provide explanations for complex transformations.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:52 +09:00
Masahiro Yamada
d607e0e7a8 kconfig: change some expr_*() functions to bool
This clarifies the behavior of these functions.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:52 +09:00
Masahiro Yamada
a16219bdd3 scripts: move hash function from scripts/kconfig/ to scripts/include/
This function was originally added by commit 8af27e1dc4 ("fixdep: use
hash table instead of a single array").

Move it to scripts/include/ so that other host programs can use it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-20 09:21:52 +09:00
Masahiro Yamada
a9d83d7478 kbuild: split x*alloc() functions in kconfig to scripts/include/xalloc.h
These functions will be useful for other host programs.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-01 20:34:48 +09:00
Masahiro Yamada
96490176f1 kconfig: remove P_SYMBOL property
P_SYMBOL is a pseudo property that was previously used for data linking
purposes.

It is no longer used except for debug prints. Remove it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-01 20:34:48 +09:00
Masahiro Yamada
5e6cc7e3f2 kconfig: stop adding P_SYMBOL property to symbols
I believe its last usage was in the following code:

    if (prop == NULL)
            prop = stack->sym->prop;

This code was previously used to print the file name and line number of
associated symbols in sym_check_print_recursive(), which was removed by
commit 9d0d266046 ("kconfig: recursive checks drop file/lineno").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-01 20:34:48 +09:00
Masahiro Yamada
dc73a57aea kconfig: remove dummy assignments to cur_{filename,lineno}
Since commit ca4c74ba30 ("kconfig: remove P_CHOICE property"),
menu_finalize() no longer calls menu_add_symbol(). No function
references cur_filename or cur_lineno after yyparse().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-01 20:34:47 +09:00
Anders Roxell
33330bcf03 scripts: kconfig: merge_config: config files: add a trailing newline
When merging files without trailing newlines at the end of the file, two
config fragments end up at the same row if file1.config doens't have a
trailing newline at the end of the file.

file1.config "CONFIG_1=y"
file2.config "CONFIG_2=y"
./scripts/kconfig/merge_config.sh -m .config file1.config file2.config

This will generate a .config looking like this.
cat .config
...
CONFIG_1=yCONFIG_2=y"

Making sure so we add a newline at the end of every config file that is
passed into the script.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-08-06 14:02:12 +09:00
Masahiro Yamada
fbaf242c95 kbuild: move some helper headers from scripts/kconfig/ to scripts/include/
Move array_size.h, hashtable.h, list.h, list_types.h from scripts/kconfig/
to scripts/include/.

These headers will be useful for other host programs.

Remove scripts/mod/list.h.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-21 23:10:43 +09:00
HONG Yifan
9d0d266046 kconfig: recursive checks drop file/lineno
This prevents segfault when getting filename and lineno in recursive
checks.

If the following snippet is found in Kconfig:

[Test code 1]

config FOO
        bool
        depends on BAR
        select BAR

... without BAR defined; then there is a segfault.

  Kconfig:34:error: recursive dependency detected!
  Kconfig:34:	symbol FOO depends on BAR
  make[4]: *** [scripts/kconfig/Makefile:85: allnoconfig] Segmentation fault

This is because of the following. BAR is a fake entry created by
sym_lookup() with prop being NULL. In the recursive check, there is a
NULL check for prop to fall back to stack->sym->prop if stack->prop is
NULL. However, in this case, stack->sym points to the fake BAR entry
created by sym_lookup(), so prop is still NULL. prop was then referenced
without additional NULL checks, causing segfault.

As the previous email thread suggests, the file and lineno for select is
also wrong:

[Test code 2]

config FOO
       bool

config BAR
       bool

config FOO
       bool "FOO"
       depends on BAR
       select BAR

  $ make defconfig
  *** Default configuration is based on 'x86_64_defconfig'
  Kconfig:1:error: recursive dependency detected!
  Kconfig:1: symbol FOO depends on BAR
  Kconfig:4: symbol BAR is selected by FOO
  [...]

Kconfig:4 should be Kconfig:10.

This patch deletes the wrong and segfault-prone filename/lineno
inference completely. With this patch, Test code 1 yields:

error: recursive dependency detected!
	symbol FOO depends on BAR
	symbol BAR is selected by FOO

Signed-off-by: HONG Yifan <elsk@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-20 16:33:45 +09:00
Masahiro Yamada
3c2f84ceda kconfig: remove 'e1' and 'e2' macros from expression deduplication
I do not think the macros 'e1' and 'e2' are readable.

The statement:

    e1 = expr_alloc_symbol(...);

affects the caller's variable, but this is not sufficiently clear from the code.

Remove the macros. No functional change intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-20 13:34:18 +09:00
Masahiro Yamada
94a4b0a4cb kconfig: remove SYMBOL_CHOICEVAL flag
This flag is unneeded because a choice member can be detected by
other means.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 16:07:14 +09:00
Masahiro Yamada
6425e3b247 kconfig: add const qualifiers to several function arguments
Clarify that the given structures are not modified.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 16:07:14 +09:00
Masahiro Yamada
8bfd6f0923 kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups()
Kconfig simplifies expressions, but redundant '&&' and '||' operators
involving constant symbols 'y' and 'n' are sometimes trimmed and
sometimes not.

[Test Code]

    config DEP
            def_bool y

    config A
            bool "A"
            depends on DEP && y

    config B
            bool "B"
            depends on DEP && y && y

[Result]

    $ make helpnewconfig
      [ snip ]
    -----

    There is no help available for this option.
    Symbol: A [=n]
    Type  : bool
    Defined at Kconfig:4
      Prompt: A
      Depends on: DEP [=y] && y [=y]
      Location:
        -> A (A [=n])

    -----
    -----

    There is no help available for this option.
    Symbol: B [=n]
    Type  : bool
    Defined at Kconfig:8
      Prompt: B
      Depends on: DEP [=y]
      Location:
        -> B (B [=n])

    -----

The dependency for A, 'DEP && y', remains as-is, while that for B,
'DEP && y && y', has been reduced to 'DEP'.

Currently, expr_eliminate_dups() calls expr_eliminate_yn() only when
trans_count != 0, in other words, only when expr_eliminate_dups1() has
trimmed at least one leaf. It fails to trim a single '&& y', etc.

To fix this inconsistent behavior, expr_eliminate_yn() should be called
at least once even if no leaf has been trimmed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 16:07:14 +09:00
Masahiro Yamada
d5afb4824f kconfig: refactor error messages in sym_check_print_recursive()
Improve the error messages and clean up redundant code.

[1] remove redundant next_sym->name checks

If 'next_sym' is a choice, the first 'if' block is executed. In the
subsequent 'else if' blocks, 'next_sym" is not a choice, hence
next_sym->name is not NULL.

[2] remove redundant sym->name checks

A choice is never selected or implied by anyone because it has no name
(it is syntactically impossible). If it is, sym->name is not NULL.

[3] Show the location of choice instead of "<choice>"

"part of choice <choice>" does not convey useful information. Since a
choice has no name, it is more informative to display the file name and
line number.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:38 +09:00
Masahiro Yamada
d67624d814 kconfig: improve error message for recursive dependency in choice
Kconfig detects recursive dependencies in a choice block, but the error
message is unclear.

[Test Code]

    choice
            prompt "choose"
            depends on A

    config A
            bool "A"

    config B
            bool "B"

    endchoice

[Result]

    Kconfig:1:error: recursive dependency detected!
    Kconfig:1:      choice <choice> contains symbol A
    Kconfig:5:      symbol A is part of choice <choice>
    For a resolution refer to Documentation/kbuild/kconfig-language.rst
    subsection "Kconfig recursive dependency limitations"

The phrase "contains symbol A" does not accurately describe the problem.
The issue is that the choice depends on A, which is a member of itself.

The first if-block does not print a sensible message. Remove it.

This commit improves the error message to:

    Kconfig:1:error: recursive dependency detected!
    Kconfig:1:      symbol <choice> symbol is visible depending on A
    Kconfig:5:      symbol A is part of choice <choice>
    For a resolution refer to Documentation/kbuild/kconfig-language.rst
    subsection "Kconfig recursive dependency limitations"

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:38 +09:00
Masahiro Yamada
1a7d0ea83e kconfig: improve error message for dependency between choice members
A choice member must not depend on another member within the same choice
block.

Kconfig detects this, but the error message is not sensible.

[Test Code]

    choice
            prompt "choose"

    config A
            bool "A"
            depends on B

    config B
            bool "B"

    endchoice

[Result]

    Kconfig:1:error: recursive dependency detected!
    Kconfig:1:      choice <choice> contains symbol A
    Kconfig:4:      symbol A is part of choice B
    Kconfig:8:      symbol B is part of choice <choice>
    For a resolution refer to Documentation/kbuild/kconfig-language.rst
    subsection "Kconfig recursive dependency limitations"

The phrase "part of choice B" is weird because B is not a choice block,
but a choice member.

To determine whether the current symbol is a part of a choice block,
sym_is_choice(next_sym) must be checked.

This commit improves the error message to:

    Kconfig:1:error: recursive dependency detected!
    Kconfig:1:      choice <choice> contains symbol A
    Kconfig:4:      symbol A symbol is visible depending on B
    Kconfig:8:      symbol B is part of choice <choice>
    For a resolution refer to Documentation/kbuild/kconfig-language.rst
    subsection "Kconfig recursive dependency limitations"

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:38 +09:00
Masahiro Yamada
d533828ef3 kconfig: fix conditional prompt behavior for choice
When a prompt is followed by "if <expr>", the symbol is configurable
when the if-conditional evaluates to true.

A typical usage is as follows:

    menuconfig BLOCK
            bool "Enable the block layer" if EXPERT
            default y

When EXPERT=n, the prompt is hidden, but this config entry is still
active, and BLOCK is set to its default value 'y'. When EXPERT=y, the
prompt is shown, making BLOCK a user-configurable option.

This usage is common throughout the kernel tree, but it has never worked
within a choice block.

[Test Code]

    config EXPERT
            bool "Allow expert users to modify more options"

    choice
            prompt "Choose" if EXPERT

    config A
            bool "A"

    config B
            bool "B"

    endchoice

[Result]

    # CONFIG_EXPERT is not set

When the prompt is hidden, the choice block should produce the default
without asking for the user's preference. Hence, the output should be:

    # CONFIG_EXPERT is not set
    CONFIG_A=y
    # CONFIG_B is not set

Removing unnecessary hacks fixes the issue.

This commit also changes the behavior of 'select' by choice members.

[Test Code 2]

    config MODULES
            def_bool y
            modules

    config DEP
            def_tristate m

    if DEP

    choice
            prompt "choose"

    config A
            bool "A"
            select C

    endchoice

    config B
            def_bool y
            select D

    endif

    config C
            tristate

    config D
            tristate

The current output is as follows:

    CONFIG_MODULES=y
    CONFIG_DEP=m
    CONFIG_A=y
    CONFIG_B=y
    CONFIG_C=y
    CONFIG_D=m

With this commit, the output will be changed as follows:

    CONFIG_MODULES=y
    CONFIG_DEP=m
    CONFIG_A=y
    CONFIG_B=y
    CONFIG_C=m
    CONFIG_D=m

CONFIG_C will be changed to 'm' because 'select C' will inherit the
dependency on DEP, which is 'm'.

This change is aligned with the behavior of 'select' outside a choice
block; 'select D' depends on DEP, therefore D is selected by (B && DEP).

Note:

With this commit, allmodconfig will set CONFIG_USB_ROLE_SWITCH to 'm'
instead of 'y'. I did not see any build regression with this change.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
7c9bb07a6e kconfig: remove E_LIST expression type
E_LIST was preveously used to form an expression tree consisting of
choice members.

It is no longer used.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
ca4c74ba30 kconfig: remove P_CHOICE property
P_CHOICE is a pseudo property used to link a choice with its members.

There is no more code relying on this, except for some debug code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
b139b43e9d kconfig: use sym_get_choice_menu() in sym_check_deps()
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>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
609fc4099b kconfig: use sym_get_choice_menu() in sym_check_choice_deps()
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>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
d8f8bbcf4b kconfig: use sym_get_choice_menu() in sym_check_print_recursive()
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>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
8926bc901d kconfig: remove expr_list_for_each_sym() macro
All users of this macro have been converted. Remove it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
6e6d0e917a kconfig: use menu_list_for_each_sym() in sym_choice_default()
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>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
e8fcd915e3 kconfig: change sym_choice_default() to take the choice menu
Change the argument of sym_choice_default() to ease further cleanups.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
cca318378d kconfig: remove conf_unsaved in conf_read_simple()
This variable is unnecessary. Call conf_set_changed(true) directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
bd0db4b6ad kconfig: remove sym_get_choice_value()
sym_get_choice_value(menu->sym) is equivalent to sym_calc_choice(menu).

Convert all call sites of sym_get_choice_value() and then remove it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
f79dc03fe6 kconfig: refactor choice value calculation
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>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
ee29e6204c kconfig: import list_move(_tail) and list_for_each_entry_reverse macros
Import more macros from include/linux/list.h.

These will be used in the next commit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:37 +09:00
Masahiro Yamada
9b11452083 kconfig: remember the current choice while parsing the choice block
Instead of the boolean flag, it will be more useful to remember the
current choice being parsed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
bd988e7cb8 kconfig: introduce choice_set_value() helper
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
dfe8e56fc6 kconfig: add fallthrough comments to expr_compare_type()
Clarify the missing 'break' is intentional.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
cd90952101 kconfig: remove unneeded code in expr_compare_type()
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
e570ef438f kconfig: add -e and -u options to *conf-cfg.sh scripts
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
995150e4de kconfig: refactor conf_write_defconfig() to reduce indentation level
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
826ee96dd4 kconfig: refactor conf_set_all_new_symbols() to reduce indentation level
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
fde192511b kconfig: remove tristate choice support
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
03638aaa79 kconfig: pass new conf_changed value to the callback
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>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
0b62fe46d7 kconfig: gconf: move conf_changed() definition up
Define conf_changed() before its call site to remove the forward
declaration.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
300bf53ecb kconfig: gconf: remove unnecessary forward declarations
These are defined before their call sites.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16 01:08:36 +09:00
Masahiro Yamada
060e05c3b4 kconfig: qconf: remove initial call to conf_changed()
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>
2024-07-16 01:08:36 +09:00