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 <yamada.masahiro@socionext.com> Reviewed-by: Petr Vorel <petr.vorel@gmail.com> |
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LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.