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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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.
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.
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, 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>
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>
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>
