[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Graeme Russ]

Hi All,

As a bit of a lark, I ran the following shell command:

grep -r -h -o -G "#define CONFIG.*" * | \
sed 's/#define[ \t]*//' | \
sed 's/^\([A-Za-z0-9_]*\).*/\1/' | \
sort -u > README.configuration.options

I then ran the result through the following script into
README.configuration.options.counted

#!/bin/bash
INPUT=doc/README.configuration.options

#!/bin/bash
INPUT=doc/README.configuration.options

for i in `cat $INPUT`
do
	grep -rcs --exclude-dir=doc '\<'${i}'\>' * | \
	cut -d : -f 2 | \
	awk '{sum+=$1} END {printf("%d\t%s\n", sum, f);}' f=$i
done

The result? 5539 lines of pure configuration option goodness :)

Here's a little snippet:

6	CONFIG_100MHz
8	CONFIG_133MHZ_DRAM
7	CONFIG_300MHz
13	CONFIG_405
24	CONFIG_405CR
88	CONFIG_405EP
81	CONFIG_405EX

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Albert ARIBAUD]

Hi Graeme,

Le 11/04/2011 15:11, Graeme Russ a ?crit :

> So my RFC is twofold:
>   1) Should we start to systematically remove unused options

I would tend to answer 'yes'. Unused options should not clobber code or 
documentation.

>   2) Should we centralise all options in a single README (or two, one for
> standard CONFIG options and one for CONFIG_SYS options)?

That would be nice indeed, but it requires all options to have the same 
semantics over all arches. While this is highly desirable, it may not be 
true ATM -- just thinking out loud, haven't checked. But even if some 
options only make sense only for some arch(es), then we could always do 
it this way:

	doc/README.CONFIG_options
	doc/README.CONFIG_SYS_options
	doc/arch/README.CONFIG_options

> Regards,
>
> Graeme

Amicalement,
-- 
Albert.

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Graeme Russ]

On 14/04/11 16:17, Albert ARIBAUD wrote:
> Hi Graeme,
> 
> Le 11/04/2011 15:11, Graeme Russ a ?crit :
> 
>> So my RFC is twofold:
>>   1) Should we start to systematically remove unused options
> 
> I would tend to answer 'yes'. Unused options should not clobber code or 
> documentation.
> 
>>   2) Should we centralise all options in a single README (or two, one for
>> standard CONFIG options and one for CONFIG_SYS options)?
> 
> That would be nice indeed, but it requires all options to have the same 
> semantics over all arches. While this is highly desirable, it may not be 
> true ATM -- just thinking out loud, haven't checked. But even if some 
> options only make sense only for some arch(es), then we could always do 
> it this way:
> 
> 	doc/README.CONFIG_options
> 	doc/README.CONFIG_SYS_options
> 	doc/arch/README.CONFIG_options

Hmm, I have a better idea after I can to the realisation that the central
location for configuration options is Ctrl^F in the doc/ directory :)

	doc/README.CONFIG_options.unused
	doc/README.CONFIG_options.undocumented

I will tweak my scripts to produce these two files and see what the result is.

Regards,

Graeme

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Kumar Gala]

>> From this it is easy to find unused options (CONFIG_ARIA is found only as a
> #define in include/configs/aria.h for example)
> 
> So my RFC is twofold:
> 1) Should we start to systematically remove unused options
> 2) Should we centralise all options in a single README (or two, one for
> standard CONFIG options and one for CONFIG_SYS options)?

Can you post data for which options are not used.  While I think automatic removal is harsh, I think something close to automatic is reasonable.

- k

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Graeme Russ]

On 14/04/11 19:14, Kumar Gala wrote:
>>> From this it is easy to find unused options (CONFIG_ARIA is found only as a
>> #define in include/configs/aria.h for example)
>>
>> So my RFC is twofold:
>> 1) Should we start to systematically remove unused options
>> 2) Should we centralise all options in a single README (or two, one for
>> standard CONFIG options and one for CONFIG_SYS options)?
> 
> Can you post data for which options are not used.  While I think automatic removal is harsh, I think something close to automatic is reasonable.
> 
> - k

OK, here are some quick stats:

Total CONFIG_ options : 5559
Total CONFIG_ options not documented(*)/ : 4907
Total CONFIG_ options not used in code(+) : 1136
Total CONFIG_ options not used in any board config : 645

(*) README moved into doc/ to make the count of documented options more
accurate
(+) i.e. only found in either doc/ or include/configs/

As you can see, there is scope for a LOT of code cleanup within the CONFIG_
namespace

Here is the script:

#!/bin/bash
INPUT=doc/README.configuration.options.list
OUTPUT1=doc/README.configuration.options.counted.code_usage
OUTPUT2=doc/README.configuration.options.counted.doc
OUTPUT3=doc/README.configuration.options.counted.config

echo "Catalogue Configuration Options"
grep -rhos "#define CONFIG.*" * | \
	sed 's/#define[ \t]*//' | \
	sed 's/^\([A-Za-z0-9_]*\).*/\1/' | \
	sort -u > $INPUT

echo "Counting usage of configuration options in code"
rm $OUTPUT1 2> /dev/null
for i in `cat $INPUT`
do
	x=${i}'\s'
	grep -rcs --exclude-dir=include/configs --exclude-dir=doc '\<'${i}'\>' * | \
	cut -d : -f 2 | \
	awk '{sum+=$1} END {printf("%d\t%s\n", sum, f);}' f=$i >> $OUTPUT1
done
sort -n $OUTPUT1 > tmp
rm $OUTPUT1 2> /dev/null
mv tmp $OUTPUT1


echo "Counting documented options"
rm $OUTPUT2 2> /dev/null
for i in `cat $INPUT`
do
	x=${i}'\s'
	grep -rcs '\<'${i}'\>' doc/* --exclude=README.configuration.* | \
	cut -d : -f 2 | \
	awk '{sum+=$1} END {printf("%d\t%s\n", sum, f);}' f=$i >> $OUTPUT2
done
sort -n $OUTPUT2 > tmp
rm $OUTPUT2 2> /dev/null
mv tmp $OUTPUT2

echo "Counting usage of configuration options in board configuration files"
rm $OUTPUT3 2> /dev/null
for i in `cat $INPUT`
do
	x=${i}'\s'
	grep -rcs '\<'${i}'\>' include/configs/* | \
	cut -d : -f 2 | \
	awk '{sum+=$1} END {printf("%d\t%s\n", sum, f);}' f=$i >> $OUTPUT3
done
sort -n $OUTPUT3 > tmp
rm $OUTPUT3 2> /dev/null
mv tmp $OUTPUT3

echo "Done"

Regards,

Graeme

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Timur Tabi]

On Sat, Apr 16, 2011 at 2:16 AM, Graeme Russ <graeme.russ@gmail.com> wrote:

> #!/bin/bash
> INPUT=doc/README.configuration.options.list
> OUTPUT1=doc/README.configuration.options.counted.code_usage
> OUTPUT2=doc/README.configuration.options.counted.doc
> OUTPUT3=doc/README.configuration.options.counted.config

How about Makefiles?  Sometimes a CONFIG option is used only in a Makefiles.

-- 
Timur Tabi
Linux kernel developer at Freescale

[U-Boot] [RFC] Centralise documentation of CONFIG_ options (and finding unused ones)

[Graeme Russ]

On Sunday, April 17, 2011, Timur Tabi <timur@freescale.com> wrote:
> On Sat, Apr 16, 2011 at 2:16 AM, Graeme Russ <graeme.russ@gmail.com> wrote:
>
>> #!/bin/bash
>> INPUT=doc/README.configuration.options.list
>> OUTPUT1=doc/README.configuration.options.counted.code_usage
>> OUTPUT2=doc/README.configuration.options.counted.doc
>> OUTPUT3=doc/README.configuration.options.counted.config
>
> How about Makefiles? ?Sometimes a CONFIG option is used only in a Makefiles.
>

code_usage includes Makefiles

Regards,

Graeme