kernel/linux.git/scripts/kconfig/expr.c, branch v6.6.131

kconfig: remove wrong expr_trans_bool()

2024-07-25T07:50:44+00:00

[ 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 Acked-by: Randy Dunlap Signed-off-by: Sasha Levin

kconfig: distinguish between dependencies and visibility in help text

2020-01-06T17:18:45+00:00

Kconfig makes a distinction between dependencies (defined by "depends on" expressions and enclosing "if" blocks) and visibility (which includes all dependencies, but also includes inline "if" expressions of individual properties as well as, for prompts, "visible if" expressions of enclosing menus). Before commit bcdedcc1afd6 ("menuconfig: print more info for symbol without prompts"), the "Depends on" lines of a symbol's help text indicated the visibility of the prompt property they appeared under. After bcdedcc1afd, there was always only a single "Depends on" line, which indicated the visibility of the first P_SYMBOL property of the symbol. Since P_SYMBOLs never have inline if expressions, this was in effect the same as the dependencies of the menu item that the P_SYMBOL was attached to. Neither of these situations accurately conveyed the dependencies of a symbol--the first because it was actually the visibility, and the second because it only showed the dependencies from a single definition. With this series, we are back to printing separate dependencies for each definition, but we print the actual dependencies (rather than the visibility) in the "Depends on" line. However, it can still be useful to know the visibility of a prompt, so this patch adds a "Visible if" line that shows the visibility only if the visibility is different from the dependencies (which it isn't for most prompts in Linux). Before: Symbol: THUMB2_KERNEL [=n] Type : bool Defined at arch/arm/Kconfig:1417 Prompt: Compile the kernel in Thumb-2 mode Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n] Location: -> Kernel Features Selects: ARM_UNWIND [=n] After: Symbol: THUMB2_KERNEL [=n] Type : bool Defined at arch/arm/Kconfig:1417 Prompt: Compile the kernel in Thumb-2 mode Depends on: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n] Visible if: (CPU_V7 [=y] || CPU_V7M [=n]) && !CPU_V6 [=n] && !CPU_V6K [=n] && !CPU_THUMBONLY [=n] Location: -> Kernel Features Selects: ARM_UNWIND [=n] Signed-off-by: Thomas Hebb Signed-off-by: Masahiro Yamada

kconfig: don't crash on NULL expressions in expr_eq()

2019-12-17T10:21:07+00:00

NULL expressions are taken to always be true, as implemented by the expr_is_yes() macro and by several other functions in expr.c. As such, they ought to be valid inputs to expr_eq(), which compares two expressions. Signed-off-by: Thomas Hebb Signed-off-by: Masahiro Yamada

kconfig: split some C files out of zconf.y

2018-12-28T13:22:38+00:00

I want to compile each C file independently instead of including all of them from zconf.y. Split out confdata.c, expr.c, symbol.c, and preprocess.c . These are low-hanging fruits. Signed-off-by: Masahiro Yamada

kconfig: convert to SPDX License Identifier

2018-12-28T13:22:28+00:00

All files in lxdialog/ are licensed under GPL-2.0+, and the rest are under GPL-2.0. I added GPL-2.0 tags to test scripts in tests/. Documentation/process/license-rules.rst does not suggest anything about the flex/bison files. Because flex does not accept the C++ comment style at the very top of a file, I used the C style for zconf.l, and so for zconf.y for consistency. Signed-off-by: Masahiro Yamada

kconfig: remove k_invalid from expr_parse_string() return type

2018-12-08T01:42:42+00:00

The only possibility of k_invalid being returned was when expr_parse_sting() parsed S_OTHER type symbol. This actually never happened, and this is even clearer since S_OTHER has gone. Clean up unreachable code. Signed-off-by: Masahiro Yamada

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: Print reverse dependencies in groups

2018-03-25T17:03:58+00:00

Surprisingly or not, disabling a CONFIG option (which is assumed to be unneeded) may be not so trivial. Especially it is not trivial, when this CONFIG option is selected by a dozen of other configs. Before the moment commit 1ccb27143360 ("kconfig: make "Selected by:" and "Implied by:" readable") popped up in v4.16-rc1, it was an absolute pain to break down the "Selected by" reverse dependency expression in order to identify all those configs which select (IOW *do not allow disabling*) a certain feature (assumed to be not needed). This patch tries to make one step further by putting at users' fingertips the revdep top level OR sub-expressions grouped/clustered by the tristate value they evaluate to. This should allow the users to directly concentrate on and tackle the _active_ reverse dependencies. To give some numbers and quantify the complexity of certain reverse dependencies, assuming commit 617aebe6a97e ("Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux"), ARCH=arm64 and vanilla arm64 defconfig, here is the top 10 CONFIG options with the highest amount of top level "||" sub-expressions/tokens that make up the final "Selected by" reverse dependency expression. | Config | All revdep | Active revdep | |-------------------|------------|---------------| | REGMAP_I2C | 212 | 9 | | CRC32 | 167 | 25 | | FW_LOADER | 128 | 5 | | MFD_CORE | 124 | 9 | | FB_CFB_IMAGEBLIT | 114 | 2 | | FB_CFB_COPYAREA | 111 | 2 | | FB_CFB_FILLRECT | 110 | 2 | | SND_PCM | 103 | 2 | | CRYPTO_HASH | 87 | 19 | | WATCHDOG_CORE | 86 | 6 | The story behind the above is that users need to visually review/evaluate 212 expressions which *potentially* select REGMAP_I2C in order to identify the expressions which *actually* select REGMAP_I2C, for a particular ARCH and for a particular defconfig used. To make this experience smoother, change the way reverse dependencies are displayed to the user from [1] to [2]. [1] Old representation of DMA_ENGINE_RAID: Selected by: - AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || 440SP) - BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ... - FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ... - INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64 - MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ... - MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y] - XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ... - DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y] [2] New representation of DMA_ENGINE_RAID: Selected by [y]: - MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y] Selected by [m]: - BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ... Selected by [n]: - AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || ... - FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ... - INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64 - MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ... - XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ... - DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y] Suggested-by: Masahiro Yamada Signed-off-by: Eugeniu Rosca Reviewed-by: Petr Vorel Reviewed-by: Ulf Magnusson Signed-off-by: Masahiro Yamada

kconfig: clean-up reverse dependency help implementation

2018-03-25T17:03:57+00:00

This commit splits out the special E_OR handling ('-' instead of '||') into a dedicated helper expr_print_revdev(). Restore the original expr_print() prior to commit 1ccb27143360 ("kconfig: make "Selected by:" and "Implied by:" readable"). This makes sense because: - We need to chop those expressions only when printing the reverse dependency, and only when E_OR is encountered - Otherwise, it should be printed as before, so fall back to expr_print() This also improves the behavior; for a single line, it was previously displayed in the same line as "Selected by", like this: Selected by: A [=n] && B [=n] This will be displayed in a new line, consistently: Selected by: - A [=n] && B [=n] Signed-off-by: Masahiro Yamada Reviewed-by: Petr Vorel

kconfig: send error messages to stderr

2018-02-08T19:10:10+00:00

These messages should be directed to stderr. Signed-off-by: Masahiro Yamada Reviewed-by: Ulf Magnusson