kernel/linux.git/scripts/kconfig/symbol.c, branch v4.20.5

kconfig: improve the recursive dependency report

2018-08-22T14:21:39+00:00

This commit improves the messages of the recursive dependency. Currently, sym->dir_dep.expr is not checked. Hence, any dependency in property visibility is regarded as the dependency of the symbol. [Test Code 1] config A bool "a" depends on B config B bool "b" depends on A [Test Code 2] config A bool "a" if B config B bool "b" depends on A For both cases above, the same message is displayed: symbol B depends on A symbol A depends on B This commit changes the message for the latter, like this: symbol B depends on A symbol A prompt is visible depending on B Also, 'select' and 'imply' are distinguished. Signed-off-by: Masahiro Yamada Tested-by: Dirk Gouders

kconfig: report recursive dependency involving 'imply'

2018-08-22T14:21:39+00:00

Currently, Kconfig does not complain about the recursive dependency where 'imply' keywords are involved. [Test Code] config A bool "a" config B bool "b" imply A depends on A In the code above, Kconfig cannot calculate the symbol values correctly due to the circular dependency. For example, allyesconfig followed by syncconfig results in an odd behavior because CONFIG_B becomes visible in syncconfig. $ make allyesconfig scripts/kconfig/conf --allyesconfig Kconfig # # configuration written to .config # $ cat .config # # Automatically generated file; DO NOT EDIT. # Main menu # CONFIG_A=y $ make syncconfig scripts/kconfig/conf --syncconfig Kconfig * * Restart config... * * * Main menu * a (A) [Y/n/?] y b (B) [N/y/?] (NEW) To detect this correctly, sym_check_expr_deps() should recurse to not only sym->rev_dep.expr but also sym->implied.expr . At this moment, sym_check_print_recursive() cannot distinguish 'select' and 'imply' since it does not know the precise context where the recursive dependency has been hit. This will be solved by the next commit. In fact, even the document and the unit-test are confused. Using 'imply' does not solve recursive dependency since 'imply' addresses the unmet direct dependency, which 'select' could cause. Signed-off-by: Masahiro Yamada Tested-by: Dirk Gouders

kconfig: error out when seeing recursive dependency

2018-08-22T14:21:38+00:00

Originally, recursive dependency was a fatal error for Kconfig because Kconfig cannot compute symbol values in such a situation. Commit d595cea62403 ("kconfig: print more info when we see a recursive dependency") changed it to a warning, which I guess was not intentional. Get it back to an error again. Also, rename the unit test directory "warn_recursive_dep" to "err_recursive_dep" so that it matches to the behavior. Signed-off-by: Masahiro Yamada Tested-by: Dirk Gouders

kconfig: remove P_ENV property type

2018-08-14T00:01:47+00:00

This property is not set by anyone since commit 104daea149c4 ("kconfig: reference environment variables directly and remove 'option env='"). Signed-off-by: Masahiro Yamada Acked-by: Sam Ravnborg

kconfig: remove unused sym_get_env_prop() function

2018-08-13T23:59:57+00:00

This function is unused since commit 104daea149c4 ("kconfig: reference environment variables directly and remove 'option env='"). Signed-off-by: Masahiro Yamada Acked-by: Sam Ravnborg

kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE

2018-07-17T16:18:09+00:00

Over time, the use of the flag SYMBOL_AUTO changed from initially marking three automatically generated symbols ARCH, KERNELRELEASE and UNAME_RELEASE to today's effect of protecting symbols from being written out. Currently, only symbols of type CHOICE and those with option defconf_list set have that flag set. Reflect that change in semantics in the flag's name. Signed-off-by: Dirk Gouders Signed-off-by: Masahiro Yamada

kconfig: remove sym_expand_string_value()

2018-05-28T18:31:19+00:00

There is no more caller of sym_expand_string_value(). Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook

kconfig: reference environment variables directly and remove 'option env='

2018-05-28T18:28:58+00:00

To get access to environment variables, Kconfig needs to define a symbol using "option env=" syntax. It is tedious to add a symbol entry for each environment variable given that we need to define much more such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability in Kconfig. Adding '$' for symbol references is grammatically inconsistent. Looking at the code, the symbols prefixed with 'S' are expanded by: - conf_expand_value() This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list' - sym_expand_string_value() This is used to expand strings in 'source' and 'mainmenu' All of them are fixed values independent of user configuration. So, they can be changed into the direct expansion instead of symbols. This change makes the code much cleaner. The bounce symbols 'SRCARCH', 'ARCH', 'SUBARCH', 'KERNELVERSION' are gone. sym_init() hard-coding 'UNAME_RELEASE' is also gone. 'UNAME_RELEASE' should be replaced with an environment variable. ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced without '$' prefix. The new syntax is addicted by Make. The variable reference needs parentheses, like $(FOO), but you can omit them for single-letter variables, like $F. Yet, in Makefiles, people tend to use the parenthetical form for consistency / clarification. At this moment, only the environment variable is supported, but I will extend the concept of 'variable' later on. The variables are expanded in the lexer so we can simplify the token handling on the parser side. For example, the following code works. [Example code] config MY_TOOLCHAIN_LIST string default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)" [Result] $ make -s alldefconfig && tail -n 1 .config CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E" Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook

kconfig: make unmet dependency warnings readable

2018-03-25T17:04:06+00:00

Currently, the unmet dependency warnings end up with endlessly long expressions, most of which are false positives. Here is test code to demonstrate how it currently works. [Test Case] config DEP1 def_bool y config DEP2 bool "DEP2" config A bool "A" select E config B bool "B" depends on DEP2 select E config C bool "C" depends on DEP1 && DEP2 select E config D def_bool n select E config E bool depends on DEP1 && DEP2 [Result] $ make config scripts/kconfig/conf --oldaskconfig Kconfig * * Linux Kernel Configuration * DEP2 (DEP2) [N/y/?] (NEW) n A (A) [N/y/?] (NEW) y warning: (A && B && D) selects E which has unmet direct dependencies (DEP1 && DEP2) Here, I see some points to be improved. First, '(A || B || D)' would make more sense than '(A && B && D)'. I am not sure if this is intentional, but expr_simplify_unmet_dep() turns OR expressions into AND, like follows: case E_OR: return expr_alloc_and( Second, we see false positives. 'A' is a real unmet dependency. 'B' is false positive because 'DEP1' is fixed to 'y', and 'B' depends on 'DEP2'. 'C' was correctly dropped by expr_simplify_unmet_dep(). 'D' is also false positive because it has no chance to be enabled. Current expr_simplify_unmet_dep() cannot avoid those false positives. After all, I decided to use the same helpers as used for printing reverse dependencies in the help. With this commit, unreadable warnings (most of the reported symbols are false positives) in the real world: $ make ARCH=score allyesconfig scripts/kconfig/conf --allyesconfig Kconfig warning: (HWSPINLOCK_QCOM && AHCI_MTK && STMMAC_PLATFORM && DWMAC_IPQ806X && DWMAC_LPC18XX && DWMAC_OXNAS && DWMAC_ROCKCHIP && DWMAC_SOCFPGA && DWMAC_STI && TI_CPSW && PINCTRL_GEMINI && PINCTRL_OXNAS && PINCTRL_ROCKCHIP && PINCTRL_DOVE && PINCTRL_ARMADA_37XX && PINCTRL_STM32 && S3C2410_WATCHDOG && VIDEO_OMAP3 && VIDEO_S5P_FIMC && USB_XHCI_MTK && RTC_DRV_AT91SAM9 && LPC18XX_DMAMUX && VIDEO_OMAP4 && COMMON_CLK_GEMINI && COMMON_CLK_ASPEED && COMMON_CLK_NXP && COMMON_CLK_OXNAS && COMMON_CLK_BOSTON && QCOM_ADSP_PIL && QCOM_Q6V5_PIL && QCOM_GSBI && ATMEL_EBI && ST_IRQCHIP && RESET_IMX7 && PHY_HI6220_USB && PHY_RALINK_USB && PHY_ROCKCHIP_PCIE && PHY_DA8XX_USB) selects MFD_SYSCON which has unmet direct dependencies (HAS_IOMEM) warning: (PINCTRL_AT91 && PINCTRL_AT91PIO4 && PINCTRL_OXNAS && PINCTRL_PISTACHIO && PINCTRL_PIC32 && PINCTRL_MESON && PINCTRL_NOMADIK && PINCTRL_MTK && PINCTRL_MT7622 && GPIO_TB10X) selects OF_GPIO which has unmet direct dependencies (GPIOLIB && OF && HAS_IOMEM) warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && LOCKDEP) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS) will be turned into: $ make ARCH=score allyesconfig scripts/kconfig/conf --allyesconfig Kconfig WARNING: unmet direct dependencies detected for MFD_SYSCON Depends on [n]: HAS_IOMEM [=n] Selected by [y]: - PINCTRL_STM32 [=y] && PINCTRL [=y] && (ARCH_STM32 || COMPILE_TEST [=y]) && OF [=y] - RTC_DRV_AT91SAM9 [=y] && RTC_CLASS [=y] && (ARCH_AT91 || COMPILE_TEST [=y]) - RESET_IMX7 [=y] && RESET_CONTROLLER [=y] - PHY_HI6220_USB [=y] && (ARCH_HISI && ARM64 || COMPILE_TEST [=y]) - PHY_RALINK_USB [=y] && (RALINK || COMPILE_TEST [=y]) - PHY_ROCKCHIP_PCIE [=y] && (ARCH_ROCKCHIP && OF [=y] || COMPILE_TEST [=y]) WARNING: unmet direct dependencies detected for OF_GPIO Depends on [n]: GPIOLIB [=y] && OF [=y] && HAS_IOMEM [=n] Selected by [y]: - PINCTRL_MTK [=y] && PINCTRL [=y] && (ARCH_MEDIATEK || COMPILE_TEST [=y]) && OF [=y] - PINCTRL_MT7622 [=y] && PINCTRL [=y] && (ARCH_MEDIATEK || COMPILE_TEST [=y]) && OF [=y] && (ARM64 || COMPILE_TEST [=y]) WARNING: unmet direct dependencies detected for FRAME_POINTER Depends on [n]: DEBUG_KERNEL [=y] && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS [=n] Selected by [y]: - LATENCYTOP [=y] && DEBUG_KERNEL [=y] && STACKTRACE_SUPPORT [=y] && PROC_FS [=y] && !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC && !X86 Signed-off-by: Masahiro Yamada Reviewed-by: Petr Vorel

kconfig: warn unmet direct dependency of tristate symbols selected by y

2018-03-25T17:04:05+00:00

Commit 246cf9c26bf1 ("kbuild: Warn on selecting symbols with unmet direct dependencies") forcibly promoted ->dir_dep.tri to yes from mod. So, the unmet direct dependencies of tristate symbols are not reported. [Test Case] config MODULES def_bool y option modules config A def_bool y select B config B tristate "B" depends on m This causes unmet dependency because 'B' is forced 'y' ignoring 'depends on m'. This should be warned. On the other hand, the following case ('B' is bool) should not be warned, so 'depends on m' for bool symbols should be naturally treated as 'depends on y'. [Test Case2 (not unmet dependency)] config MODULES def_bool y option modules config A def_bool y select B config B bool "B" depends on m Signed-off-by: Masahiro Yamada