Re: [PATCH 1/2] kconfig: remove unneeded symbol_empty variable

Geert Uytterhoeven
2024-01-23T12:54:40Z

Hi Yamada-san,

On Sat, Nov 25, 2023 at 5:36 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
> This is used only for initializing other variables.
>
> Use the empty string "".
>
> Please note newval.tri is unused for S_INT/HEX/STRING.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Thanks for your patch, which is now commit 4e244c10eab345a7
("kconfig: remove unneeded symbol_empty variable") in v6.8-rc1.

When running "make <foo>_defconfig" with <foo>_defconfig an SMP
defconfig without explicit configuration of CONFIG_LOG_CPU_MAX_BUF_SHIFT,
the aforementioned commit causes a change in the generated .config:

-CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
+CONFIG_LOG_CPU_MAX_BUF_SHIFT=0

It looks like CONFIG_BASE_SMALL=0 is treated as a string instead of
the integer number zero?

init/Kconfig=config LOG_CPU_MAX_BUF_SHIFT
init/Kconfig- int "CPU kernel log buffer size contribution (13 => 8
KB, 17 => 128KB)"
init/Kconfig- depends on SMP
init/Kconfig- range 0 21
init/Kconfig: default 12 if !BASE_SMALL
init/Kconfig: default 0 if BASE_SMALL

Note that reverting 4e244c10eab345a7 is not sufficient to fix the issue.
Also reverting commit 6262afa10ef7cc8f ("kconfig: default to zero if
int/hex symbol lacks default property") does fix it.

Thanks!

> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -29,12 +29,6 @@ struct symbol symbol_no = {
> .flags = SYMBOL_CONST|SYMBOL_VALID,
> };
>
> -static struct symbol symbol_empty = {
> - .name = "",
> - .curr = { "", no },
> - .flags = SYMBOL_VALID,
> -};
> -
> struct symbol *modules_sym;
> static tristate modules_val;
>
> @@ -346,7 +340,7 @@ void sym_calc_value(struct symbol *sym)
> case S_INT:
> case S_HEX:
> case S_STRING:
> - newval = symbol_empty.curr;
> + newval.val = "";
> break;
> case S_BOOLEAN:
> case S_TRISTATE:
> @@ -697,13 +691,12 @@ const char *sym_get_string_default(struct symbol *sym)
> {
> struct property *prop;
> struct symbol *ds;
> - const char *str;
> + const char *str = "";
> tristate val;
>
> sym_calc_visibility(sym);
> sym_calc_value(modules_sym);
> val = symbol_no.curr.tri;
> - str = symbol_empty.curr.val;
>
> /* If symbol has a default value look it up */
> prop = sym_get_default_prop(sym);

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds