Re: [PATCH] Script to check for undefined Kconfig symbols - v2

[Paolo Giarrusso <blaisorblade@yahoo.it>]

On Fri, 24 Aug 2007 Randy Dunlap wrote:
> On Fri, 24 Aug 2007 16:56:49 +0200 Paolo 'Blaisorblade' Giarrusso wrote:
> 
> > In this version, I've updated the scripts to search for "\<$symb_bare\>" instead
> > of $symb_bare in Kconfig files. Please ignore my previous message.
> >
> > To avoid to look manually for used but undefined Kconfig variables, I've
> > written a script which tries do this efficiently, in case all other attention
> > fail. It accounts for _MODULE suffix and for UML_ prefixes to Kconfig variable,
> > but otherwise looks for exact matches (i.e. \<CONFIG_; this is done to exclude
> > macros like MMCONFIG_).
> >
> > Undefined Kconfig variables should be not be removed without care, but for
> > instance arch/i386/boot/ uses a bunch of undefined Kconfig vars:
> >
> > $ scripts/checkunknowndefines.sh arch/i386/boot/
> > arch/i386/boot/video.h uses undefined symbol VIDEO_400_HACK
> > arch/i386/boot/video-vga.c uses undefined symbol VIDEO_400_HACK
> > arch/i386/boot/video.c uses undefined symbol VIDEO_RETAIN
> > arch/i386/boot/video.h uses undefined symbol VIDEO_RETAIN
> > arch/i386/boot/video.h uses undefined symbol VIDEO_SVGA
> > arch/i386/boot/video.h uses undefined symbol VIDEO_VESA
> > arch/i386/boot/video-vesa.c uses undefined symbol VIDEO_VESA
> >
> > Hope you can merge this in -mm and use it frequently (probably, a script to look for
> > regressions in its output is useful). It should also be mentioned in
> > SubmittingPatches if you agree.
> 
> or added to Documentation/SubmitChecklist.

Indeed - that's what I should have written, but I had forgot the exact file name.

> How does this script compare to
> http://www.fsdev.net/wiki/index.php?title=Misspelled_CONFIG_variables
> and
> http://www.fsdev.net/wiki/index.php?title=Dead_CONFIG_variables
> ?

They are the same, but they do not identify the files containing the dead var.
It may be worth to just "grep back" in kernel sources for the dead symbol to
readd this feature, but it may be slower that way.

The difference is that since I find symbols together with file name, I cannot
use uniq but I must use that awk script.

Anyway, do we agree that a script for this should be probably
merged in kernel sources?

Thanks for your answer.

> > Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
> > ---
> >
> >  scripts/checkunknowndefines.sh |   59 ++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 59 insertions(+), 0 deletions(-)
> >
> > diff --git a/scripts/checkunknowndefines.sh b/scripts/checkunknowndefines.sh
> > new file mode 100755
> > index 0000000..dbb5cef
> > --- /dev/null
> > +++ b/scripts/checkunknowndefines.sh
> > @@ -0,0 +1,59 @@
> > +#!/bin/sh
> > +# Find Kconfig variables used in source code but never defined in Kconfig
> > +# Copyright (C) 2007, Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
> > +
> > +# Tested with dash.
> > +paths="$@"
> > +[ -z "$paths" ] && paths=.
> > +
> > +# Doing this once at the beginning saves a lot of time, on a cache-hot tree.
> > +Kconfigs="`find . -name 'Kconfig' -o -name 'Kconfig*[^~]'`"
> > +
> > +echo "File list \tundefined symbol used"
> > +find $paths -name '*.[chS]' -o -name 'Makefile' -o -name 'Makefile*[^~]'| while read i
> > +do
> > +    # Output the bare Kconfig variable and the filename; the _MODULE part at
> > +    # the end is not removed here (would need perl an not-hungry regexp for that).
> > +    sed -ne 's!^.*\<\(UML_\)\?CONFIG_\([0-9A-Z_]\+\).*!\2 '$i'!p' < $i
> > +done | \
> > +# Smart "sort|uniq" implemented in awk and tuned to collect the names of all
> > +# files which use a given symbol
> > +awk '{map[$1, count[$1]++] = $2; }
> > +END {
> > +    for (combIdx in map) {
> > +        split(combIdx, separate, SUBSEP);
> > +        # The value may have been removed.
> > +        if (! ( (separate[1], separate[2]) in map ) )
> > +            continue;
> > +        symb=separate[1];
> > +        printf "%s ", symb;
> > +        #Use gawk extension to delete the names vector
> > +        delete names;
> > +        #Portably delete the names vector
> > +        #split("", names);
> > +        for (i=0; i < count[symb]; i++) {
> > +            names[map[symb, i]] = 1;
> > +            # Unfortunately, we may still encounter symb, i in the
> > +            # outside iteration.
> > +            delete map[symb, i];
> > +        }
> > +        i=0;
> > +        for (name in names) {
> > +            if (i > 0)
> > +                printf ", %s", name;
> > +            else
> > +                printf "%s", name;
> > +            i++;
> > +        }
> > +        printf "\n";
> > +    }
> > +}' |
> > +while read symb files; do
> > +    # Remove the _MODULE suffix when checking the variable name. This should
> > +    # be done only on tristate symbols, actually, but Kconfig parsing is
> > +    # beyond the purpose of this script.
> > +    symb_bare=`echo $symb | sed -e 's/_MODULE//'`
> > +    if ! grep -q "\<$symb_bare\>" $Kconfigs; then
> > +        echo "$files: \t$symb"
> > +    fi
> > +done|sort
> 
> 
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***




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