Re: [PATCH v3 3/3] kconfig: Print reverse dependencies in groups

Ulf Magnusson
2018-02-17T16:55:03Z

On Sat, Feb 17, 2018 at 3:05 AM, Eugeniu Rosca <roscaeugeniu@gmail.com> wrote:
> From: Eugeniu Rosca <erosca@de.adit-jv.com>
>
> 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,Implied} by" reverse dependency expression.
>
> | Config | Revdep all | Revdep ![=n] |
> |-------------------------------|------------|--------------|
> | 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 reverse dependencies for 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 reverse dependencies for 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]
>
> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
> ---
> scripts/kconfig/expr.c | 59 ++++++++++++++++++++++++++++++++++++++++++++-
> scripts/kconfig/expr.h | 4 +++
> scripts/kconfig/lkc_proto.h | 1 +
> scripts/kconfig/menu.c | 37 ++++++++++++++++++++--------
> 4 files changed, 90 insertions(+), 11 deletions(-)
>
> diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
> index c610cb14284f..48b99371d276 100644
> --- a/scripts/kconfig/expr.c
> +++ b/scripts/kconfig/expr.c
> @@ -1213,6 +1213,18 @@ __expr_print(struct expr *e,
> case PRINT_REVDEP_ALL:
> expr_print_newline(e, fn, data, E_OR);
> break;
> + case PRINT_REVDEP_YES:
> + if (expr_calc_value(e) == yes)
> + expr_print_newline(e, fn, data, E_OR);
> + break;
> + case PRINT_REVDEP_MOD:
> + if (expr_calc_value(e) == mod)
> + expr_print_newline(e, fn, data, E_OR);
> + break;
> + case PRINT_REVDEP_NO:
> + if (expr_calc_value(e) == no)
> + expr_print_newline(e, fn, data, E_OR);
> + break;

Perhaps this logic could be moved into expr_print_newline() (which
could be renamed to something like expr_print_select() in that case).
Could have it take 'enum print_type' as an argument.

> default:
> break;
> }
> @@ -1273,6 +1285,18 @@ __expr_print(struct expr *e,
> case PRINT_REVDEP_ALL:
> expr_print_newline(e, fn, data, E_OR);
> break;
> + case PRINT_REVDEP_YES:
> + if (expr_calc_value(e) == yes)
> + expr_print_newline(e, fn, data, E_OR);
> + break;
> + case PRINT_REVDEP_MOD:
> + if (expr_calc_value(e) == mod)
> + expr_print_newline(e, fn, data, E_OR);
> + break;
> + case PRINT_REVDEP_NO:
> + if (expr_calc_value(e) == no)
> + expr_print_newline(e, fn, data, E_OR);
> + break;

That would simplify this part as well, since they're equal.

> default:
> break;
> }
> @@ -1353,10 +1377,43 @@ void expr_gstr_print(struct expr *e, struct gstr *gs)
> expr_print(e, expr_print_gstr_helper, gs, E_NONE);
> }
>
> +/*
> + * Allow front ends to check if a specific reverse dependency expression
> + * has at least one top level "||" member which evaluates to "val". This,
> + * will allow front ends to, as example, avoid printing "Selected by [y]:"
> + * line when there are actually no top level "||" sub-expressions which
> + * evaluate to =y.
> + */
> +bool expr_revdep_contains(struct expr *e, tristate val)
> +{
> + bool ret = false;
> +
> + if (!e)
> + return ret;
> +
> + switch (e->type) {
> + case E_SYMBOL:
> + case E_AND:
> + if (expr_calc_value(e) == val)
> + ret = true;
> + break;
> + case E_OR:
> + if (expr_revdep_contains(e->left.expr, val))
> + ret = true;
> + else if (expr_revdep_contains(e->right.expr, val))
> + ret = true;
> + break;
> + default:
> + break;
> + }
> + return ret;
> +}
> +
> /*
> * Transform the top level "||" tokens into newlines and prepend each
> * line with a minus. This makes expressions much easier to read.
> - * Suitable for reverse dependency expressions.
> + * Suitable for reverse dependency expressions. In addition, allow
> + * selective printing of tokens/sub-expressions by their tristate value.
> */
> void expr_gstr_print_revdep(struct expr *e, struct gstr *gs, enum print_type t)
> {
> diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h
> index 21cb67c15091..d5b096725ca8 100644
> --- a/scripts/kconfig/expr.h
> +++ b/scripts/kconfig/expr.h
> @@ -37,6 +37,9 @@ enum expr_type {
> enum print_type {
> PRINT_NORMAL,
> PRINT_REVDEP_ALL,

PRINT_REVDEP_ALL is unused now, right?

Guess it doesn't hurt that much to have it there, though I'm more of a
"it won't be needed" person.

> + PRINT_REVDEP_YES,
> + PRINT_REVDEP_MOD,
> + PRINT_REVDEP_NO,
> };
>
> union expr_data {
> @@ -316,6 +319,7 @@ void expr_fprint(struct expr *e, FILE *out);
> struct gstr; /* forward */
> void expr_gstr_print(struct expr *e, struct gstr *gs);
> void expr_gstr_print_revdep(struct expr *e, struct gstr *gs, enum print_type t);
> +bool expr_revdep_contains(struct expr *e, tristate val);
>
> static inline int expr_is_yes(struct expr *e)
> {
> diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
> index 9dc8abfb1dc3..69ed1477e4ef 100644
> --- a/scripts/kconfig/lkc_proto.h
> +++ b/scripts/kconfig/lkc_proto.h
> @@ -25,6 +25,7 @@ bool menu_has_help(struct menu *menu);
> const char * menu_get_help(struct menu *menu);
> struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head);
> void menu_get_ext_help(struct menu *menu, struct gstr *help);
> +void get_revdep_by_type(struct expr *e, char *s, struct gstr *r);
>
> /* symbol.c */
> extern struct symbol * symbol_hash[SYMBOL_HASHSIZE];
> diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
> index 5b8edba105f2..d13ffa69d65b 100644
> --- a/scripts/kconfig/menu.c
> +++ b/scripts/kconfig/menu.c
> @@ -790,6 +790,31 @@ static void get_symbol_props_str(struct gstr *r, struct symbol *sym,
> str_append(r, "\n");
> }
>
> +void get_revdep_by_type(struct expr *e, char *s, struct gstr *r)
> +{
> + if (!e)
> + return;
> +
> + if (expr_revdep_contains(e, yes)) {
> + str_append(r, s);
> + str_append(r, _(" [y]:"));
> + expr_gstr_print_revdep(e, r, PRINT_REVDEP_YES);
> + str_append(r, "\n");
> + }
> + if (expr_revdep_contains(e, mod)) {
> + str_append(r, s);
> + str_append(r, _(" [m]:"));
> + expr_gstr_print_revdep(e, r, PRINT_REVDEP_MOD);
> + str_append(r, "\n");
> + }
> + if (expr_revdep_contains(e, no)) {
> + str_append(r, s);
> + str_append(r, _(" [n]:"));
> + expr_gstr_print_revdep(e, r, PRINT_REVDEP_NO);
> + str_append(r, "\n");
> + }
> +}

Those _() are for gettext btw. Not sure those strings need
translations (or if anyone is translating Kconfig), so I think they
could be removed here.

> +
> /*
> * head is optional and may be NULL
> */
> @@ -826,18 +851,10 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym,
> }
>
> get_symbol_props_str(r, sym, P_SELECT, _(" Selects: "));
> - if (sym->rev_dep.expr) {
> - str_append(r, _(" Selected by: "));
> - expr_gstr_print_revdep(sym->rev_dep.expr, r, PRINT_REVDEP_ALL);
> - str_append(r, "\n");
> - }
> + get_revdep_by_type(sym->rev_dep.expr, " Selected by", r);
>
> get_symbol_props_str(r, sym, P_IMPLY, _(" Implies: "));
> - if (sym->implied.expr) {
> - str_append(r, _(" Implied by: "));
> - expr_gstr_print_revdep(sym->implied.expr, r, PRINT_REVDEP_ALL);
> - str_append(r, "\n");
> - }
> + get_revdep_by_type(sym->implied.expr, " Implied by", r);
>
> str_append(r, "\n\n");
> }
> --
> 2.16.1
>

Looks like a very nice patchset in general to me.

Cheers,
Ulf