Re: [PATCH 1/2] kconfig: Print full defined and depends for multiply-defined symbols

Stefan Hengelein
2015-04-11T16:36:30Z

2015-04-10 23:25 GMT+02:00 Paul Bolle <pebolle@tiscali.nl>:
> [Removed Yann. Added the people that I hope might actually understand
> what this is all about.]
>
> On Wed, 2015-04-08 at 16:56 -0700, Gregory Fong wrote:
>> get_symbol_str() was assuming that symbols would only have a single
>> property for the purpose of printing define and depends information.
>> This is not true, and one current example is FRAME_POINTER which is
>> both in lib/Kconfig.debug and arch/arm/Kconfig.debug.
>>
>> In order to print out the correct Defined and Depends info, iterate
>> over all properties associated with the given symbol, similarly to was
>> done for selects. And for depends, rather than iterating over the
>> property, just use the direct dependency expression.
>>
>> CONFIG_FRAME_POINTER text, before:
>> Defined at lib/Kconfig.debug:323
>> Depends on: DEBUG_KERNEL [=y] && (ARM [=y] || CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS [=n]
>>
>> After:
>> Defined at lib/Kconfig.debug:323, arch/arm/Kconfig.debug:35
>> Depends on: DEBUG_KERNEL [=y] && (ARM [=y] || CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS [=n] || !THUMB2_KERNEL [=n]
>
> Note that there are currently six places where FRAME_POINTER is defined:
> arch/arm/Kconfig.debug:35:config FRAME_POINTER
> arch/arm64/Kconfig.debug:5:config FRAME_POINTER
> arch/hexagon/Kconfig:40:config FRAME_POINTER
> arch/m32r/Kconfig.debug:13:config FRAME_POINTER
> arch/sparc/Kconfig.debug:19:config FRAME_POINTER
> lib/Kconfig.debug:323:config FRAME_POINTER
>
> Anyhow, does anyone dare to state that the After: line above describes
> FRAME_POINTER for arm correctly? (Of course, I could dive in the semi
> documented kconfig code myself. But that might mean that Gregory will be
> waiting for feedback for quite some time.)
>

With my current knowledge of kconfig i would say: depends on what the
output of this is used for.
If you're reading the dependency list as "what do i have to enable to
be able to choose a value for FRAME_POINTER" and think, THUMB2_KERNEL
would be a good choice to leave disabled, you're going to have a bad
time.
(The second definition in arm/Kconfig.debug doesn't have a prompt and
the default has additional conditions)

If it should just point out, FRAME_POINTER could be enabled, the
"After Depends on:" is right. However, the conditions for the Default
in the second definition still would have to be satisfied.

If the whole list of kconfig menus is dumped, i'd expect there to be a
second print:
Defined at arch/arm/Kconfig.debug:35
Depends on: !THUMB2_KERNEL [=n]

After doing some reading:
the function is used in the search and help function for mconf to
print the dependencies and, at least in my output, did include a
Prompt statement. i'd say to add "!THUMB2_KERNEL" to the dependency
could be misleading! however the second definition of the symbol is
not hit by a search for FRAME_POINTER. I personally would prefer to
additionally find the second definition that doesn't a prompt and
other dependencies instead of adding them to the first entry, but
that's just my personal preference.

Stefan

>> Removes now-unused function get_symbol_prop().
>
> It might be better to do that in a separate patch.
>
>> Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
>> ---
>> scripts/kconfig/menu.c | 35 +++++++++++++++--------------------
>> 1 file changed, 15 insertions(+), 20 deletions(-)
>>
>> diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
>> index 72c9dba..da482ff 100644
>> --- a/scripts/kconfig/menu.c
>> +++ b/scripts/kconfig/menu.c
>> @@ -601,18 +601,6 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
>> }
>>
>> /*
>> - * get property of type P_SYMBOL
>> - */
>> -static struct property *get_symbol_prop(struct symbol *sym)
>> -{
>> - struct property *prop = NULL;
>> -
>> - for_all_properties(sym, prop, P_SYMBOL)
>> - break;
>> - return prop;
>> -}
>> -
>> -/*
>> * head is optional and may be NULL
>> */
>> void get_symbol_str(struct gstr *r, struct symbol *sym,
>> @@ -637,15 +625,22 @@ void get_symbol_str(struct gstr *r, struct symbol *sym,
>> for_all_prompts(sym, prop)
>> get_prompt_str(r, prop, head);
>>
>> - prop = get_symbol_prop(sym);
>> - if (prop) {
>> - str_printf(r, _(" Defined at %s:%d\n"), prop->menu->file->name,
>> + hit = false;
>> + for_all_properties(sym, prop, P_SYMBOL) {
>> + if (!hit) {
>> + str_append(r, " Defined at ");
>> + hit = true;
>> + } else
>> + str_append(r, ", ");
>> + str_printf(r, _("%s:%d"), prop->menu->file->name,
>> prop->menu->lineno);
>> - if (!expr_is_yes(prop->visible.expr)) {
>> - str_append(r, _(" Depends on: "));
>> - expr_gstr_print(prop->visible.expr, r);
>> - str_append(r, "\n");
>> - }
>> + }
>> + if (hit)
>> + str_append(r, "\n");
>> + if (!expr_is_yes(sym->dir_dep.expr)) {
>> + str_append(r, _(" Depends on: "));
>> + expr_gstr_print(sym->dir_dep.expr, r);
>> + str_append(r, "\n");
>> }
>>
>> hit = false;
>
> Thanks,
>
>
> Paul Bolle
>