Re: [PATCH v2] kconfig: make unmet dependency warnings readable

From: Petr Vorel
Date: Tue Mar 06 2018 - 11:49:25 EST


Hi Masahiro,

...
> $ make allyesconfig
> scripts/kconfig/conf --allyesconfig Kconfig
> 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)'.
Good point, make sense, current is really confusing.

> 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 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 && DWMA
> C_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 && LP
> C18XX_DMAMUX && VIDEO_OMAP4 && COMMON_CLK_GEMINI && COMMON_CLK_ASPEED && C
> OMMON_CLK_NXP && COMMON_CLK_OXNAS && COMMON_CLK_BOSTON && ATMEL_ST && QCOM
> _ADSP_PIL && QCOM_Q6V5_PIL && QCOM_GSBI && ATMEL_EBI && ST_IRQCHIP && RESE
> T_IMX7 && PHY_HI6220_USB && PHY_RALINK_USB && PHY_ROCKCHIP_PCIE && PHY_DA8
> XX_USB) selects MFD_SYSCON which has unmet direct dependencies (HAS_IOMEM)
> warning: (PINCTRL_AT91 && PINCTRL_AT91PIO4 && PINCTRL_OXNAS && PINCTRL_PIS
> TACHIO && PINCTRL_PIC32 && PINCTRL_MESON && PINCTRL_NOMADIK && PINCTRL_MTK
> && PINCTRL_MT7622 && GPIO_TB10X) selects OF_GPIO which has unmet direct d
> ependencies (GPIOLIB && OF && HAS_IOMEM)
> warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && LOCKDEP) sele
> cts FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CR
> IS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARC
> H_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:
> 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])
> - ATMEL_ST [=y] && GENERIC_CLOCKEVENTS [=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:
> 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:
> 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

Although I liked the brevity of current form (one liner is nice), fixing false positives
justify it enough. The same look and feel with help and reusing code makes are also pros.

> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Reviewed-by: Petr Vorel <petr.vorel@xxxxxxxxx>

...
> +static void sym_warn_unmet_dependency(struct symbol *sym)
> +{
> + struct gstr gs = str_new();
> +
> + str_printf(&gs, "\nWARNING:\n");
> + str_printf(&gs, " Unmet direct dependencies detected for %s\n",

Just one change: keep error on the same line as 'WARNING:':
str_printf(&gs, "\nWARNING: Unmet direct dependencies detected for %s\n",
It's make easier to grep error and save space vertically.


Kind regards,
Petr