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Date: Mon, 12 Mar 2018 23:59:45 +0100
From: Eugeniu Rosca <erosca@...adit-jv.com>
To: Masahiro Yamada <yamada.masahiro@...ionext.com>
CC: <linux-kbuild@...r.kernel.org>,
Ulf Magnusson <ulfalizer@...il.com>,
Petr Vorel <pvorel@...e.cz>,
Randy Dunlap <rdunlap@...radead.org>,
Sam Ravnborg <sam@...nborg.org>,
Michal Marek <michal.lkml@...kovi.net>,
<linux-kernel@...r.kernel.org>,
Eugeniu Rosca <erosca@...adit-jv.com>,
Eugeniu Rosca <rosca.eugeniu@...il.com>
Subject: Re: [PATCH v3] kconfig: make unmet dependency warnings readable
Hi Masahiro,
Some "final polishing" review comments. Feel free to pick/drop them at
your will.
On Sun, Mar 11, 2018 at 12:51:59AM +0900, Masahiro Yamada wrote:
> 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 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:
Here imho `Depends on [n]:` is more inline with the "Selected by [y|m]"
family, but this could be subjective. `[n]` might be helpful for long
direct dependencies, like seen below for FRAME_POINTER. No strong
preference about it.
> HAS_IOMEM [=n]
Adding a minus in front of expression, i.e. ` - HAS_IOMEM [=n]`
is probably more inline with how reverse dependencies are printed.
> Selected by [y]:
Shifting this line to the right by one space symbol would resemble the
`make menuconfig` output. No strong preference about it.
> - 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:
Likewise, shifting the above line to the right by one space would make
it similar to what's generated by `make menuconfig`.
> 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
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
> Reviewed-by: Petr Vorel <petr.vorel@...il.com>
> ---
>
> Changes in v3:
> - Remove unused expr_get_leftmost_symbol()
> - Move error message to the same line as 'WARNING'
> - update test case
>
> Changes in v2:
> - update test case
>
> scripts/kconfig/expr.c | 42 ------------------------------------------
> scripts/kconfig/expr.h | 1 -
> scripts/kconfig/symbol.c | 34 ++++++++++++++++++++++------------
> 3 files changed, 22 insertions(+), 55 deletions(-)
>
> diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
> index 49376e1..e1a39e9 100644
> --- a/scripts/kconfig/expr.c
> +++ b/scripts/kconfig/expr.c
> @@ -1137,48 +1137,6 @@ static int expr_compare_type(enum expr_type t1, enum expr_type t2)
> return 0;
> }
>
> -static inline struct expr *
> -expr_get_leftmost_symbol(const struct expr *e)
> -{
> -
> - if (e == NULL)
> - return NULL;
> -
> - while (e->type != E_SYMBOL)
> - e = e->left.expr;
> -
> - return expr_copy(e);
> -}
> -
> -/*
> - * Given expression `e1' and `e2', returns the leaf of the longest
> - * sub-expression of `e1' not containing 'e2.
> - */
> -struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2)
> -{
> - struct expr *ret;
> -
> - switch (e1->type) {
> - case E_OR:
> - return expr_alloc_and(
> - expr_simplify_unmet_dep(e1->left.expr, e2),
> - expr_simplify_unmet_dep(e1->right.expr, e2));
> - case E_AND: {
> - struct expr *e;
> - e = expr_alloc_and(expr_copy(e1), expr_copy(e2));
> - e = expr_eliminate_dups(e);
> - ret = (!expr_eq(e, e1)) ? e1 : NULL;
> - expr_free(e);
> - break;
> - }
> - default:
> - ret = e1;
> - break;
> - }
> -
> - return expr_get_leftmost_symbol(ret);
> -}
> -
> void expr_print(struct expr *e,
> void (*fn)(void *, struct symbol *, const char *),
> void *data, int prevtoken)
> diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
> index 8dbf2a4..94a383b 100644
> --- a/scripts/kconfig/expr.h
> +++ b/scripts/kconfig/expr.h
> @@ -305,7 +305,6 @@ struct expr *expr_transform(struct expr *e);
> int expr_contains_symbol(struct expr *dep, struct symbol *sym);
> bool expr_depends_symbol(struct expr *dep, struct symbol *sym);
> struct expr *expr_trans_compare(struct expr *e, enum expr_type type, struct symbol *sym);
> -struct expr *expr_simplify_unmet_dep(struct expr *e1, struct expr *e2);
>
> void expr_fprint(struct expr *e, FILE *out);
> struct gstr; /* forward */
> diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
> index 0f7eba7..8b13c16 100644
> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -333,6 +333,26 @@ static struct symbol *sym_calc_choice(struct symbol *sym)
> return def_sym;
> }
>
> +static void sym_warn_unmet_dependency(struct symbol *sym)
Based on the current naming pattern of kconfig functions:
$> ctags -x --c-types=f scripts/kconfig/*.c | cut -d' ' -f1 | grep dep
dep_stack_insert
dep_stack_remove
expr_depends_symbol
expr_gstr_print_revdep
expr_simplify_unmet_dep
file_write_dep
menu_add_dep
sym_check_choice_deps
sym_check_deps
sym_check_expr_deps
sym_check_sym_deps
You could also consider below variants:
* sym_warn_unmet_dep()
* sym_warn_unmet_deps()
* sym_warn_unmet_dirdep()
> +{
> + struct gstr gs = str_new();
> +
> + str_printf(&gs,
> + "\nWARNING: unmet direct dependencies detected for %s\n"
> + " Depends on:\n"
> + " ",
> + sym->name);
> + expr_gstr_print(sym->dir_dep.expr, &gs);
> + str_printf(&gs, "\n");
> +
> + expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
> + " Selected by [y]:\n");
> + expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
> + " Selected by [m]:\n");
> +
> + fputs(str_get(&gs), stderr);
> +}
> +
> void sym_calc_value(struct symbol *sym)
> {
> struct symbol_value newval, oldval;
> @@ -414,18 +434,8 @@ void sym_calc_value(struct symbol *sym)
> }
> }
> calc_newval:
> - if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
> - struct expr *e;
> - e = expr_simplify_unmet_dep(sym->rev_dep.expr,
> - sym->dir_dep.expr);
> - fprintf(stderr, "warning: (");
> - expr_fprint(e, stderr);
> - fprintf(stderr, ") selects %s which has unmet direct dependencies (",
> - sym->name);
> - expr_fprint(sym->dir_dep.expr, stderr);
> - fprintf(stderr, ")\n");
> - expr_free(e);
> - }
> + if (sym->dir_dep.tri == no && sym->rev_dep.tri != no)
> + sym_warn_unmet_dependency(sym);
> newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
> }
> if (newval.tri == mod &&
> --
> 2.7.4
>
Best regards,
Eugeniu.
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