android_kernel_motorola_sm6375/scripts/kconfig
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Masahiro Yamada 59fc8ffb54 kconfig: remove wrong expr_trans_bool()
[ Upstream commit 77a92660d8fe8d29503fae768d9f5eb529c88b36 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-27 10:38:29 +02:00
..
lxdialog kconfig: remove trailing whitespaces 2019-05-09 22:37:17 +09:00
tests docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
.gitignore kconfig: rename generated .*conf-cfg to *conf-cfg 2019-01-06 10:47:09 +09:00
conf.c kconfig: Fix spelling of sym_is_changable 2019-07-06 21:58:23 +09:00
confdata.c kconfig: fix failing to generate auto.conf 2022-02-23 12:00:01 +01:00
expr.c kconfig: remove wrong expr_trans_bool() 2024-07-27 10:38:29 +02:00
expr.h kconfig: remove wrong expr_trans_bool() 2024-07-27 10:38:29 +02:00
gconf-cfg.sh
gconf.c kconfig: gconf: give a proper initial state to the Save button 2024-07-27 10:38:29 +02:00
gconf.glade
images.c kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings 2018-12-28 22:22:39 +09:00
images.h kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings 2018-12-28 22:22:39 +09:00
lexer.l kconfig: fix infinite loop when expanding a macro at the end of file 2024-03-26 18:22:24 -04:00
list.h
lkc.h kconfig: require the argument of --defconfig 2019-06-09 15:08:18 +09:00
lkc_proto.h kconfig: Fix spelling of sym_is_changable 2019-07-06 21:58:23 +09:00
Makefile kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) 2019-09-04 23:12:50 +09:00
mconf-cfg.sh
mconf.c kconfig: Fix spelling of sym_is_changable 2019-07-06 21:58:23 +09:00
menu.c kconfig: remove wrong expr_trans_bool() 2024-07-27 10:38:29 +02:00
merge_config.sh merge_config.sh: ignore unwanted grep errors 2019-09-04 23:12:50 +09:00
nconf-cfg.sh kconfig: Make nconf-cfg.sh executable 2019-04-09 22:44:57 +09:00
nconf.c kconfig: nconf: stop endless search loops 2021-05-19 10:08:23 +02:00
nconf.gui.c kconfig/[mn]conf: handle backspace (^H) key 2019-03-29 22:48:01 +09:00
nconf.h kconfig: convert to SPDX License Identifier 2018-12-28 22:22:28 +09:00
parser.y kconfig: rename zconf.y to parser.y 2019-02-13 23:25:58 +09:00
preprocess.c kconfig: fix possible buffer overflow 2023-09-23 10:59:57 +02:00
qconf-cfg.sh
qconf.cc kconfig: qconf: fix signal connection to invalid slots 2020-08-26 10:41:04 +02:00
qconf.h kconfig: fix 'Save As' menu of xconfig 2019-03-12 02:50:24 +09:00
streamline_config.pl kconfig: convert to SPDX License Identifier 2018-12-28 22:22:28 +09:00
symbol.c kconfig: fix comparison to constant symbols, 'm', 'n' 2024-06-16 13:28:47 +02:00
util.c kconfig: convert to SPDX License Identifier 2018-12-28 22:22:28 +09:00