wireguard-linux/scripts/kconfig/symbol.c, branch jd/bump-compilers

kconfig: recursive checks drop file/lineno

2024-07-20T07:33:45Z

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 Signed-off-by: Masahiro Yamada

kconfig: remove SYMBOL_CHOICEVAL flag

2024-07-16T07:07:14Z

This flag is unneeded because a choice member can be detected by other means. Signed-off-by: Masahiro Yamada

kconfig: add const qualifiers to several function arguments

2024-07-16T07:07:14Z

Clarify that the given structures are not modified. Signed-off-by: Masahiro Yamada

kconfig: refactor error messages in sym_check_print_recursive()

2024-07-15T16:08:38Z

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 "" "part of 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

kconfig: improve error message for recursive dependency in choice

2024-07-15T16:08:38Z

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 contains symbol A Kconfig:5: symbol A is part of 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 symbol is visible depending on A Kconfig:5: symbol A is part of choice For a resolution refer to Documentation/kbuild/kconfig-language.rst subsection "Kconfig recursive dependency limitations" Signed-off-by: Masahiro Yamada

kconfig: improve error message for dependency between choice members

2024-07-15T16:08:38Z

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 contains symbol A Kconfig:4: symbol A is part of choice B Kconfig:8: symbol B is part of 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 contains symbol A Kconfig:4: symbol A symbol is visible depending on B Kconfig:8: symbol B is part of choice For a resolution refer to Documentation/kbuild/kconfig-language.rst subsection "Kconfig recursive dependency limitations" Signed-off-by: Masahiro Yamada

kconfig: fix conditional prompt behavior for choice

2024-07-15T16:08:37Z

When a prompt is followed by "if ", 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

kconfig: remove E_LIST expression type

2024-07-15T16:08:37Z

E_LIST was preveously used to form an expression tree consisting of choice members. It is no longer used. Signed-off-by: Masahiro Yamada

kconfig: remove P_CHOICE property

2024-07-15T16:08:37Z

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

kconfig: use sym_get_choice_menu() in sym_check_deps()

2024-07-15T16:08:37Z

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