Re: [PATCH 2/6] staging: erofs: formatting fix to NULL comparison

[Dan Carpenter <dan.carpenter@oracle.com>]

[-- Attachment #1: Type: text/plain, Size: 766 bytes --]

On Fri, Aug 31, 2018 at 11:29:03AM +0800, Chao Yu wrote:
> 
> Hi Xiang,
> 
> I'm not against this change which follows checkpatch's rule, since I think this
> can help to unify coding style in different modules of Linux. Maybe cleanup in
> other filesystem is needed as well.
> 

That code is old, and those filesystems are not in staging so we're not
going to change them.

Let's just apply the patch and not spend any time thinking about it.
Part of the point of style guidelines is so that we don't have to
repeat all these discussions over and over...

Btw, I have a rename_rev.pl patch for reviewing these.  I've attached
it.  rename_rev.pl -r NULL.  I've seen some people screw up the
conversion so having an automated review is nice.

regards,
dan carpenter


[-- Attachment #2: rename_rev.pl --]
[-- Type: text/x-perl, Size: 11925 bytes --]

#!/usr/bin/perl

# This is a tool to help review variable rename patches. The goal is
# to strip out the automatic sed renames and the white space changes
# and leaves the interesting code changes.
#
# Example 1: A patch renames openInfo to open_info:
#     cat diff | rename_review.pl openInfo open_info
#
# Example 2: A patch swaps the first two arguments to some_func():
#     cat diff | rename_review.pl \
#                    -e 's/some_func\((.*?),(.*?),/some_func\($2, $1,/'
#
# Example 3: A patch removes the xkcd_ prefix from some but not all the
# variables.  Instead of trying to figure out which variables were renamed
# just remove the prefix from them all:
#     cat diff | rename_review.pl -ea 's/xkcd_//g'
#
# Example 4: A patch renames 20 CamelCase variables.  To review this let's
# just ignore all case changes and all '_' chars.
#     cat diff | rename_review -ea 'tr/[A-Z]/[a-z]/' -ea 's/_//g'
#
# The other arguments are:
# -nc removes comments
# -ns removes '\' chars if they are at the end of the line.

use strict;
use File::Temp qw/ :mktemp  /;

sub usage() {
    print "usage: cat diff | $0 old new old new old new...\n";
    print "   or: cat diff | $0 -e 's/old/new/g'\n";
    print " -a : auto";
    print " -e : execute on old lines\n";
    print " -ea: execute on all lines\n";
    print " -nc: no comments\n";
    print " -nb: no unneeded braces\n";
    print " -ns: no slashes at the end of a line\n";
    print " -pull: for function pull.  deletes context.\n";
    print " -r <recipe>: NULL, bool";
    exit(1);
}
my @subs;
my @strict_subs;
my @cmds;
my $strip_comments;
my $strip_braces;
my $strip_slashes;
my $pull_context;
my $auto;

sub filter($) {
    my $line = shift();
    my $old = 0;
    if ($line =~ /^-/) {
        $old = 1;
    }
    # remove the first char
    $line =~ s/^[ +-]//;
    if ($strip_comments) {
        $line =~ s/\/\*.*?\*\///g;
        $line =~ s/\/\/.*//;
    }
    foreach my $cmd (@cmds) {
        if ($old || $cmd->[0] =~ /^-ea$/) {
            eval "\$line =~ $cmd->[1]";
        }
    }
    foreach my $sub (@subs) {
        if ($old) {
            $line =~ s/$sub->[0]/$sub->[1]/g;
        }
    }
    foreach my $sub (@strict_subs) {
        if ($old) {
            $line =~ s/\b$sub->[0]\b/$sub->[1]/g;
        }
    }

    # remove the newline so we can move curly braces here if we want.
    $line =~ s/\n//;
    return $line;
}

while (my $param1 = shift()) {
    if ($param1 =~ /^-a$/) {
        $auto = 1;
        next;
    }
    if ($param1 =~ /^-nc$/) {
        $strip_comments = 1;
        next;
    }
    if ($param1 =~ /^-nb$/) {
        $strip_braces = 1;
        next;
    }
    if ($param1 =~ /^-ns$/) {
        $strip_slashes = 1;
        next;
    }
    if ($param1 =~ /^-pull$/) {
        $pull_context = 1;
        next;
    }
    my $param2 = shift();
    if ($param2 =~ /^$/) {
        usage();
    }
    if ($param1 =~ /^-e(a|)$/) {
        push @cmds, [$param1, $param2];
        next;
    }
    if ($param1 =~ /^-r$/) {
        if ($param2 =~ /bool/) {
            push @cmds, ["-e", "s/== true//"];
            push @cmds, ["-e", "s/true ==//"];
            push @cmds, ["-e", "s/([a-zA-Z\-\>\._]+) == false/!\$1/"];
            next;
        } elsif ($param2 =~ /NULL/) {
            push @cmds, ["-e", "s/ != NULL//"];
            push @cmds, ["-e", "s/([a-zA-Z\-\>\._0-9]+) == NULL/!\$1/"];
            next;
        } elsif ($param2 =~ /BIT/) {
            push @cmds, ["-e", 's/1[uU]* *<< *(\d+)/BIT($1)/'];
            push @cmds, ["-e", 's/\(1 *<< *(\w+)\)/BIT($1)/'];
            push @cmds, ["-e", 's/\(BIT\((.*?)\)\)/BIT($1)/'];
            next;
        }
        usage();
    }

    push @subs, [$param1, $param2];
}

my ($oldfh, $oldfile) = mkstemp("/tmp/oldXXXXX");
my ($newfh, $newfile) = mkstemp("/tmp/newXXXXX");

my @input = <STDIN>;

# auto works on the observation that the - line comes before the + line when we
# rename variables.  Take the first - line.  Find the first + line.  Find the
# one word difference.  Test that the old word never occurs in the new text.
if ($auto) {
    my %c_keywords = (  auto => 1,
                        break => 1,
                        case => 1,
                        char => 1,
                        const => 1,
                        continue => 1,
                        default => 1,
                        do => 1,
                        double => 1,
                        else => 1,
                        enum => 1,
                        extern => 1,
                        float => 1,
                        for => 1,
                        goto => 1,
                        if => 1,
                        int => 1,
                        long => 1,
                        register => 1,
                        return => 1,
                        short => 1,
                        signed => 1,
                        sizeof => 1,
                        static => 1,
                        struct => 1,
                        switch => 1,
                        typedef => 1,
                        union => 1,
                        unsigned => 1,
                        void => 1,
                        volatile => 1,
                        while => 1);
    my %old_words;
    my %new_words;
    my %added_cmds;
    my @new_subs;

    my $inside = 0;
    foreach my $line (@input) {
        if ($line =~ /^(---|\+\+\+)/) {
            next;
        }

        if ($line =~ /^@/) {
            $inside = 1;
        }
        if ($inside && !(($_ =~ /^[- @+]/) || ($_ =~ /^$/))) {
            $inside = 0;
        }
        if (!$inside) {
            next;
        }

        if ($line =~ /^-/) {
            s/-//;
            my @words = split(/\W+/, $line);
            foreach my $word (@words) {
                $old_words{$word} = 1;
            }
        } elsif ($line =~ /^\+/) {
            s/\+//;
            my @words = split(/\W+/, $line);
            foreach my $word (@words) {
                $new_words{$word} = 1;
            }
        }
    }

    my $old_line;
    my $new_line;
    $inside = 0;
    foreach my $line (@input) {
        if ($line =~ /^(---|\+\+\+)/) {
            next;
        }

        if ($line =~ /^@/) {
            $inside = 1;
        }
        if ($inside && !(($_ =~ /^[- @+]/) || ($_ =~ /^$/))) {
            $inside = 0;
        }
        if (!$inside) {
            next;
        }


        if ($line =~ /^-/ && !$old_line) {
            s/^-//;
            $old_line = $line;
            next;
        } elsif ($old_line && $line =~ /^\+/) {
            s/^\+//;
            $new_line = $line;
        } else {
            next;
        }

        my @old_words = split(/\W+/, $old_line);
        my @new_words = split(/\W+/, $new_line);
        my @new_cmds;

        my $i;
        my $diff_count = 0;
        for ($i = 0; ; $i++) {
            if (!defined($old_words[$i]) && !defined($new_words[$i])) {
                last;
            }
            if (!defined($old_words[$i]) || !defined($new_words[$i])) {
                $diff_count = 1000;
                last;
            }
            if ($old_words[$i] eq $new_words[$i]) {
                next;
            }
            if ($c_keywords{$old_words[$i]}) {
                $diff_count = 1000;
                last;
            }
            if ($new_words{$old_words[$i]}) {
                $diff_count++;
            }
            push @new_cmds, [$old_words[$i], $new_words[$i]];
        }
        if ($diff_count <= 2) {
            foreach my $sub (@new_cmds) {
                if ($added_cmds{$sub->[0] . $sub->[1]}) {
                    next;
                }
                $added_cmds{$sub->[0] . $sub->[1]} = 1;
                push @new_subs, [$sub->[0] , $sub->[1]];
            }
        }

        $old_line = 0;
    }

    if (@new_subs) {
        print "RENAMES:\n";
        foreach my $sub (@new_subs) {
            print "$sub->[0] => $sub->[1]\n";
            push @strict_subs, [$sub->[0] , $sub->[1]];
        }
        print "---\n";
    }
}

my $output;

#recreate an old file and a new file
my $stored_brace_line = "";
my $stored_remove_output = "";
my $del_close_brace = 0;
my $inside = 0;
foreach (@input) {
    my $orig = $_;


    if ($pull_context && !($orig =~ /^[+-@]/)) {
        next;
    }

    if ($orig =~ /^(---|\+\+\+)/) {
        next;
    }

    if ($orig =~ /^@/) {
        $inside = 1;
    }
    if ($inside && !(($orig =~ /^[- @+]/) || ($orig =~ /^$/))) {
        $inside = 0;
    }
    if (!$inside) {
        next;
    }

    $output = filter($orig);

    if ($strip_braces && $stored_brace_line =~ /^$/ && $orig =~ /^-(.*)\{$/) {
        $stored_brace_line = $output;
        next;
    }

    if ($strip_braces && $orig =~ /^-/ && !($stored_brace_line =~ /^$/)) {
        $stored_remove_output = $stored_remove_output . "\n" . $output;
        next;
    }

    if ($strip_braces && $del_close_brace && $orig =~ /^-\W+}\W+/) {
        $del_close_brace = 0;
        next;
    }

    if ($strip_braces && $orig =~ /^\+.*/ && !($stored_brace_line =~ /^$/)) {
        my $stripped_old = $stored_brace_line;
        my $stripped_new = $output;

        $stripped_old =~ s/(.*)\w*{/$1/;

        if ($stripped_old eq $stripped_new) {
            $orig = " ";
            $output = $stripped_new;
            $stored_brace_line = "";
            $del_close_brace = 1;
        }
    }

    if ($strip_braces && $orig =~ /^(\+|-)\W+{/) {
        $output =~ s/^[\t ]+(.*)/ $1/;
    } else {
        $output = "\n" . $output;
    }

    if ($orig =~ /^-/) {
        print $oldfh $output;
        next;
    }

    if ($orig =~ /^\+/) {
        print $newfh $output;
        next;
    }
    print $oldfh $output;
    print $newfh $output;

    if (!($stored_remove_output =~ /^$/)) {
            print $oldfh $stored_brace_line;
            print $oldfh $stored_remove_output;
            $stored_brace_line = "";
            $stored_remove_output = "";
    }
}
print $oldfh "\n";
print $newfh "\n";
# git diff puts a -- and version at the end of the diff.  put the -- into the
# new file as well so it's ignored
if ($output =~ /\n-/) {
    print $newfh "-\n";
}

my $hunk;
my $old_txt;
my $new_txt;

open diff, "diff -uw $oldfile $newfile |";
while (<diff>) {
    if ($_ =~ /^(---|\+\+\+)/) {
        next;
    }

    if ($_ =~ /^@/) {

        if ($strip_comments) {
            $old_txt =~ s/\/\*.*?\*\///g;
            $new_txt =~ s/\/\*.*?\*\///g;
        }
        if ($strip_braces) {
            $old_txt =~ s/{([^;{]*?);}/$1;/g;
            $new_txt =~ s/{([^;{]*?);}/$1;/g;
            # this is a hack because i don't know how to replace nested
            # unneeded curly braces.
            $old_txt =~ s/{([^;{]*?);}/$1;/g;
            $new_txt =~ s/{([^;{]*?);}/$1;/g;
        }

        if ($old_txt ne $new_txt) {
            print $hunk;
            print $_;
        }
        $hunk = "";
        $old_txt = "";
        $new_txt = "";
        next;
    }

    $hunk = $hunk . $_;

    if ($strip_slashes) {
        s/\\$//;
    }

    if ($_ =~ /^-/) {
        s/-//;
        s/[ \t\n]//g;
        $old_txt = $old_txt . $_;
        next;
    }
    if ($_ =~ /^\+/) {
        s/\+//;
        s/[ \t\n]//g;
        $new_txt = $new_txt . $_;
        next;
    }
    if ($_ =~ /^ /) {
        s/^ //;
        s/[ \t\n]//g;
        $old_txt = $old_txt . $_;
        $new_txt = $new_txt . $_;
    }
}

if ($old_txt ne $new_txt) {
    if ($strip_comments) {
        $old_txt =~ s/\/\*.*?\*\///g;
        $new_txt =~ s/\/\*.*?\*\///g;
    }
    if ($strip_braces) {
        $old_txt =~ s/{([^;{]*?);}/$1;/g;
        $new_txt =~ s/{([^;{]*?);}/$1;/g;
        $old_txt =~ s/{([^;{]*?);}/$1;/g;
        $new_txt =~ s/{([^;{]*?);}/$1;/g;
    }

    print $hunk;
}

# print "old = $oldfile new = $newfile\n";
unlink($oldfile);
unlink($newfile);

print "\ndone.\n";