[LMB] Restructure allocation loops to avoid unsigned underflow
[sfrench/cifs-2.6.git] / scripts / checkpatch.pl
index 2a7cef9726e4892b3454e7198dca4c529aeed891..58a94947d6557e0783ef1043b77cb7e8a57bc30d 100755 (executable)
@@ -9,7 +9,7 @@ use strict;
 my $P = $0;
 $P =~ s@.*/@@g;
 
-my $V = '0.15';
+my $V = '0.16';
 
 use Getopt::Long qw(:config no_auto_abbrev);
 
@@ -18,6 +18,7 @@ my $tree = 1;
 my $chk_signoff = 1;
 my $chk_patch = 1;
 my $tst_type = 0;
+my $tst_only;
 my $emacs = 0;
 my $terse = 0;
 my $file = 0;
@@ -44,6 +45,7 @@ GetOptions(
 
        'debug=s'       => \%debug,
        'test-type!'    => \$tst_type,
+       'test-only=s'   => \$tst_only,
 ) or exit;
 
 my $exit = 0;
@@ -263,17 +265,7 @@ sub expand_tabs {
        return $res;
 }
 sub copy_spacing {
-       my ($str) = @_;
-
-       my $res = '';
-       for my $c (split(//, $str)) {
-               if ($c eq "\t") {
-                       $res .= $c;
-               } else {
-                       $res .= ' ';
-               }
-       }
-
+       (my $res = shift) =~ tr/\t/ /c;
        return $res;
 }
 
@@ -290,53 +282,76 @@ sub line_stats {
        return (length($line), length($white));
 }
 
+my $sanitise_quote = '';
+
+sub sanitise_line_reset {
+       my ($in_comment) = @_;
+
+       if ($in_comment) {
+               $sanitise_quote = '*/';
+       } else {
+               $sanitise_quote = '';
+       }
+}
 sub sanitise_line {
        my ($line) = @_;
 
        my $res = '';
        my $l = '';
 
-       my $quote = '';
        my $qlen = 0;
+       my $off = 0;
+       my $c;
 
-       foreach my $c (split(//, $line)) {
-               # The second backslash of a pair is not a "quote".
-               if ($l eq "\\" && $c eq "\\") {
-                       $c = 'X';
-               }
-               if ($l ne "\\" && ($c eq "'" || $c eq '"')) {
-                       if ($quote eq '') {
-                               $quote = $c;
-                               $res .= $c;
-                               $l = $c;
-                               $qlen = 0;
-                               next;
-                       } elsif ($quote eq $c) {
-                               $quote = '';
-                       }
+       # Always copy over the diff marker.
+       $res = substr($line, 0, 1);
+
+       for ($off = 1; $off < length($line); $off++) {
+               $c = substr($line, $off, 1);
+
+               # Comments we are wacking completly including the begin
+               # and end, all to $;.
+               if ($sanitise_quote eq '' && substr($line, $off, 2) eq '/*') {
+                       $sanitise_quote = '*/';
+
+                       substr($res, $off, 2, "$;$;");
+                       $off++;
+                       next;
                }
-               if ($quote eq "'" && $qlen > 1) {
-                       $quote = '';
+               if (substr($line, $off, 2) eq $sanitise_quote) {
+                       $sanitise_quote = '';
+                       substr($res, $off, 2, "$;$;");
+                       $off++;
+                       next;
                }
-               if ($quote && $c ne "\t") {
-                       $res .= "X";
-                       $qlen++;
-               } else {
-                       $res .= $c;
+
+               # A \ in a string means ignore the next character.
+               if (($sanitise_quote eq "'" || $sanitise_quote eq '"') &&
+                   $c eq "\\") {
+                       substr($res, $off, 2, 'XX');
+                       $off++;
+                       next;
                }
+               # Regular quotes.
+               if ($c eq "'" || $c eq '"') {
+                       if ($sanitise_quote eq '') {
+                               $sanitise_quote = $c;
 
-               $l = $c;
-       }
+                               substr($res, $off, 1, $c);
+                               next;
+                       } elsif ($sanitise_quote eq $c) {
+                               $sanitise_quote = '';
+                       }
+               }
 
-       # Clear out the comments.
-       while ($res =~ m@(/\*.*?\*/)@g) {
-               substr($res, $-[1], $+[1] - $-[1]) = $; x ($+[1] - $-[1]);
-       }
-       if ($res =~ m@(/\*.*)@) {
-               substr($res, $-[1], $+[1] - $-[1]) = $; x ($+[1] - $-[1]);
-       }
-       if ($res =~ m@^.(.*\*/)@) {
-               substr($res, $-[1], $+[1] - $-[1]) = $; x ($+[1] - $-[1]);
+               #print "SQ:$sanitise_quote\n";
+               if ($off != 0 && $sanitise_quote eq '*/' && $c ne "\t") {
+                       substr($res, $off, 1, $;);
+               } elsif ($off != 0 && $sanitise_quote && $c ne "\t") {
+                       substr($res, $off, 1, 'X');
+               } else {
+                       substr($res, $off, 1, $c);
+               }
        }
 
        # The pathname on a #include may be surrounded by '<' and '>'.
@@ -359,6 +374,7 @@ sub ctx_statement_block {
        my $blk = '';
        my $soff = $off;
        my $coff = $off - 1;
+       my $coff_set = 0;
 
        my $loff = 0;
 
@@ -370,7 +386,7 @@ sub ctx_statement_block {
 
        my $remainder;
        while (1) {
-               #warn "CSB: blk<$blk>\n";
+               #warn "CSB: blk<$blk> remain<$remain>\n";
                # If we are about to drop off the end, pull in more
                # context.
                if ($off >= $len) {
@@ -393,7 +409,7 @@ sub ctx_statement_block {
                $c = substr($blk, $off, 1);
                $remainder = substr($blk, $off);
 
-               #warn "CSB: c<$c> type<$type> level<$level>\n";
+               #warn "CSB: c<$c> type<$type> level<$level> remainder<$remainder> coff_set<$coff_set>\n";
                # Statement ends at the ';' or a close '}' at the
                # outermost level.
                if ($level == 0 && $c eq ';') {
@@ -401,10 +417,14 @@ sub ctx_statement_block {
                }
 
                # An else is really a conditional as long as its not else if
-               if ($level == 0 && (!defined($p) || $p =~ /(?:\s|\})/) &&
-                               $remainder =~ /(else)(?:\s|{)/ &&
-                               $remainder !~ /else\s+if\b/) {
-                       $coff = $off + length($1);
+               if ($level == 0 && $coff_set == 0 &&
+                               (!defined($p) || $p =~ /(?:\s|\}|\+)/) &&
+                               $remainder =~ /^(else)(?:\s|{)/ &&
+                               $remainder !~ /^else\s+if\b/) {
+                       $coff = $off + length($1) - 1;
+                       $coff_set = 1;
+                       #warn "CSB: mark coff<$coff> soff<$soff> 1<$1>\n";
+                       #warn "[" . substr($blk, $soff, $coff - $soff + 1) . "]\n";
                }
 
                if (($type eq '' || $type eq '(') && $c eq '(') {
@@ -417,6 +437,8 @@ sub ctx_statement_block {
 
                        if ($level == 0 && $coff < $soff) {
                                $coff = $off;
+                               $coff_set = 1;
+                               #warn "CSB: mark coff<$coff>\n";
                        }
                }
                if (($type eq '' || $type eq '{') && $c eq '{') {
@@ -444,7 +466,7 @@ sub ctx_statement_block {
        #warn "STATEMENT<$statement>\n";
        #warn "CONDITION<$condition>\n";
 
-       #print "off<$off> loff<$loff>\n";
+       #print "coff<$coff> soff<$off> loff<$loff>\n";
 
        return ($statement, $condition,
                        $line, $remain + 1, $off - $loff + 1, $level);
@@ -502,7 +524,7 @@ sub ctx_statement_full {
        # Grab the first conditional/block pair.
        ($statement, $condition, $linenr, $remain, $off, $level) =
                                ctx_statement_block($linenr, $remain, $off);
-       #print "F: c<$condition> s<$statement>\n";
+       #print "F: c<$condition> s<$statement> remain<$remain>\n";
        push(@chunks, [ $condition, $statement ]);
        if (!($remain > 0 && $condition =~ /^\s*(?:\n[+-])?\s*(?:if|else|do)\b/s)) {
                return ($level, $linenr, @chunks);
@@ -514,7 +536,7 @@ sub ctx_statement_full {
                ($statement, $condition, $linenr, $remain, $off, $level) =
                                ctx_statement_block($linenr, $remain, $off);
                #print "C: c<$condition> s<$statement> remain<$remain>\n";
-               last if (!($remain > 0 && $condition =~ /^\s*(?:\n[+-])?\s*(?:else|do)\b/s));
+               last if (!($remain > 0 && $condition =~ /^(?:\s*\n[+-])*\s*(?:else|do)\b/s));
                #print "C: push\n";
                push(@chunks, [ $condition, $statement ]);
        }
@@ -668,6 +690,7 @@ sub annotate_values {
        print "$stream\n" if ($dbg_values > 1);
 
        while (length($cur)) {
+               @av_paren_type = ('E') if ($#av_paren_type < 0);
                print " <" . join('', @av_paren_type) .
                                        "> <$type> " if ($dbg_values > 1);
                if ($cur =~ /^(\s+)/o) {
@@ -804,28 +827,34 @@ sub possible {
 my $prefix = '';
 
 sub report {
+       if (defined $tst_only && $_[0] !~ /\Q$tst_only\E/) {
+               return 0;
+       }
        my $line = $prefix . $_[0];
 
        $line = (split('\n', $line))[0] . "\n" if ($terse);
 
        push(our @report, $line);
+
+       return 1;
 }
 sub report_dump {
        our @report;
 }
 sub ERROR {
-       report("ERROR: $_[0]\n");
-       our $clean = 0;
-       our $cnt_error++;
+       if (report("ERROR: $_[0]\n")) {
+               our $clean = 0;
+               our $cnt_error++;
+       }
 }
 sub WARN {
-       report("WARNING: $_[0]\n");
-       our $clean = 0;
-       our $cnt_warn++;
+       if (report("WARNING: $_[0]\n")) {
+               our $clean = 0;
+               our $cnt_warn++;
+       }
 }
 sub CHK {
-       if ($check) {
-               report("CHECK: $_[0]\n");
+       if ($check && report("CHECK: $_[0]\n")) {
                our $clean = 0;
                our $cnt_chk++;
        }
@@ -867,30 +896,76 @@ sub process {
        my $prev_values = 'E';
 
        # suppression flags
-       my $suppress_ifbraces = 0;
+       my %suppress_ifbraces;
 
        # Pre-scan the patch sanitizing the lines.
        # Pre-scan the patch looking for any __setup documentation.
        #
        my @setup_docs = ();
        my $setup_docs = 0;
+
+       sanitise_line_reset();
        my $line;
        foreach my $rawline (@rawlines) {
-               # Standardise the strings and chars within the input to
-               # simplify matching.
-               $line = sanitise_line($rawline);
-               push(@lines, $line);
-
-               ##print "==>$rawline\n";
-               ##print "-->$line\n";
+               $linenr++;
+               $line = $rawline;
 
-               if ($line=~/^\+\+\+\s+(\S+)/) {
+               if ($rawline=~/^\+\+\+\s+(\S+)/) {
                        $setup_docs = 0;
                        if ($1 =~ m@Documentation/kernel-parameters.txt$@) {
                                $setup_docs = 1;
                        }
-                       next;
+                       #next;
+               }
+               if ($rawline=~/^\@\@ -\d+(?:,\d+)? \+(\d+)(,(\d+))? \@\@/) {
+                       $realline=$1-1;
+                       if (defined $2) {
+                               $realcnt=$3+1;
+                       } else {
+                               $realcnt=1+1;
+                       }
+
+                       # Guestimate if this is a continuing comment.  Run
+                       # the context looking for a comment "edge".  If this
+                       # edge is a close comment then we must be in a comment
+                       # at context start.
+                       my $edge;
+                       for (my $ln = $linenr; $ln < ($linenr + $realcnt); $ln++) {
+                               next if ($line =~ /^-/);
+                               ($edge) = ($rawlines[$ln - 1] =~ m@(/\*|\*/)@);
+                               last if (defined $edge);
+                       }
+                       if (defined $edge && $edge eq '*/') {
+                               $in_comment = 1;
+                       }
+
+                       # Guestimate if this is a continuing comment.  If this
+                       # is the start of a diff block and this line starts
+                       # ' *' then it is very likely a comment.
+                       if (!defined $edge &&
+                           $rawlines[$linenr] =~ m@^.\s* \*(?:\s|$)@)
+                       {
+                               $in_comment = 1;
+                       }
+
+                       ##print "COMMENT:$in_comment edge<$edge> $rawline\n";
+                       sanitise_line_reset($in_comment);
+
+               } elsif ($realcnt) {
+                       # Standardise the strings and chars within the input to
+                       # simplify matching.
+                       $line = sanitise_line($rawline);
                }
+               push(@lines, $line);
+
+               if ($realcnt > 1) {
+                       $realcnt-- if ($line =~ /^(?:\+| |$)/);
+               } else {
+                       $realcnt = 0;
+               }
+
+               #print "==>$rawline\n";
+               #print "-->$line\n";
 
                if ($setup_docs && $line =~ /^\+/) {
                        push(@setup_docs, $line);
@@ -899,23 +974,17 @@ sub process {
 
        $prefix = '';
 
+       $realcnt = 0;
+       $linenr = 0;
        foreach my $line (@lines) {
                $linenr++;
 
                my $rawline = $rawlines[$linenr - 1];
 
-#extract the filename as it passes
-               if ($line=~/^\+\+\+\s+(\S+)/) {
-                       $realfile=$1;
-                       $realfile =~ s@^[^/]*/@@;
-                       $in_comment = 0;
-                       next;
-               }
 #extract the line range in the file after the patch is applied
                if ($line=~/^\@\@ -\d+(?:,\d+)? \+(\d+)(,(\d+))? \@\@/) {
                        $is_patch = 1;
                        $first_line = $linenr + 1;
-                       $in_comment = 0;
                        $realline=$1-1;
                        if (defined $2) {
                                $realcnt=$3+1;
@@ -925,50 +994,16 @@ sub process {
                        annotate_reset();
                        $prev_values = 'E';
 
-                       $suppress_ifbraces = $linenr - 1;
+                       %suppress_ifbraces = ();
                        next;
-               }
 
 # track the line number as we move through the hunk, note that
 # new versions of GNU diff omit the leading space on completely
 # blank context lines so we need to count that too.
-               if ($line =~ /^( |\+|$)/) {
+               } elsif ($line =~ /^( |\+|$)/) {
                        $realline++;
                        $realcnt-- if ($realcnt != 0);
 
-                       # Guestimate if this is a continuing comment.  Run
-                       # the context looking for a comment "edge".  If this
-                       # edge is a close comment then we must be in a comment
-                       # at context start.
-                       if ($linenr == $first_line) {
-                               my $edge;
-                               for (my $ln = $first_line; $ln < ($linenr + $realcnt); $ln++) {
-                                       ($edge) = ($rawlines[$ln - 1] =~ m@(/\*|\*/)@);
-                                       last if (defined $edge);
-                               }
-                               if (defined $edge && $edge eq '*/') {
-                                       $in_comment = 1;
-                               }
-                       }
-
-                       # Guestimate if this is a continuing comment.  If this
-                       # is the start of a diff block and this line starts
-                       # ' *' then it is very likely a comment.
-                       if ($linenr == $first_line and $rawline =~ m@^.\s* \*(?:\s|$)@) {
-                               $in_comment = 1;
-                       }
-
-                       # Find the last comment edge on _this_ line.
-                       $comment_edge = 0;
-                       while (($rawline =~ m@(/\*|\*/)@g)) {
-                               if ($1 eq '/*') {
-                                       $in_comment = 1;
-                               } else {
-                                       $in_comment = 0;
-                               }
-                               $comment_edge = 1;
-                       }
-
                        # Measure the line length and indent.
                        ($length, $indent) = line_stats($rawline);
 
@@ -977,23 +1012,36 @@ sub process {
                        ($previndent, $stashindent) = ($stashindent, $indent);
                        ($prevrawline, $stashrawline) = ($stashrawline, $rawline);
 
-                       #warn "ic<$in_comment> ce<$comment_edge> line<$line>\n";
+                       #warn "line<$line>\n";
 
                } elsif ($realcnt == 1) {
                        $realcnt--;
                }
 
 #make up the handle for any error we report on this line
+               $prefix = "$filename:$realline: " if ($emacs && $file);
+               $prefix = "$filename:$linenr: " if ($emacs && !$file);
+
                $here = "#$linenr: " if (!$file);
                $here = "#$realline: " if ($file);
+
+               # extract the filename as it passes
+               if ($line=~/^\+\+\+\s+(\S+)/) {
+                       $realfile = $1;
+                       $realfile =~ s@^[^/]*/@@;
+
+                       if ($realfile =~ m@include/asm/@) {
+                               ERROR("do not modify files in include/asm, change architecture specific files in include/asm-<architecture>\n" . "$here$rawline\n");
+                       }
+                       next;
+               }
+
                $here .= "FILE: $realfile:$realline:" if ($realcnt != 0);
 
                my $hereline = "$here\n$rawline\n";
                my $herecurr = "$here\n$rawline\n";
                my $hereprev = "$here\n$prevrawline\n$rawline\n";
 
-               $prefix = "$filename:$realline: " if ($emacs && $file);
-               $prefix = "$filename:$linenr: " if ($emacs && !$file);
                $cnt_lines++ if ($realcnt != 0);
 
 #check the patch for a signoff:
@@ -1005,7 +1053,7 @@ sub process {
                                        $herecurr);
                        }
                        if ($line =~ /^\s*signed-off-by:\S/i) {
-                               WARN("need space after Signed-off-by:\n" .
+                               WARN("space required after Signed-off-by:\n" .
                                        $herecurr);
                        }
                }
@@ -1072,11 +1120,6 @@ sub process {
                        WARN("CVS style keyword markers, these will _not_ be updated\n". $herecurr);
                }
 
-# The rest of our checks refer specifically to C style
-# only apply those _outside_ comments.  Only skip
-# lines in the middle of comments.
-               next if (!$comment_edge && $in_comment);
-
 # Check for potential 'bare' types
                if ($realcnt) {
                        my ($s, $c) = ctx_statement_block($linenr, $realcnt, 0);
@@ -1110,7 +1153,7 @@ sub process {
                                my ($name_len) = length($1);
 
                                my $ctx = $s;
-                               substr($ctx, 0, $name_len + 1) = '';
+                               substr($ctx, 0, $name_len + 1, '');
                                $ctx =~ s/\)[^\)]*$//;
 
                                for my $arg (split(/\s*,\s*/, $ctx)) {
@@ -1151,27 +1194,33 @@ sub process {
 
 # if/while/etc brace do not go on next line, unless defining a do while loop,
 # or if that brace on the next line is for something else
-               if ($line =~ /\b(?:(if|while|for|switch)\s*\(|do\b|else\b)/ && $line !~ /^.#/) {
+               if ($line =~ /(.*)\b((?:if|while|for|switch)\s*\(|do\b|else\b)/ && $line !~ /^.#/) {
+                       my $pre_ctx = "$1$2";
+
                        my ($level, @ctx) = ctx_statement_level($linenr, $realcnt, 0);
                        my $ctx_ln = $linenr + $#ctx + 1;
                        my $ctx_cnt = $realcnt - $#ctx - 1;
                        my $ctx = join("\n", @ctx);
 
+                       ##warn "realcnt<$realcnt> ctx_cnt<$ctx_cnt>\n";
+
                        # Skip over any removed lines in the context following statement.
-                       while ($ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^-/) {
+                       while (defined($lines[$ctx_ln - 1]) && $lines[$ctx_ln - 1] =~ /^-/) {
                                $ctx_ln++;
-                               $ctx_cnt--;
                        }
-                       ##warn "line<$line>\nctx<$ctx>\nnext<$lines[$ctx_ln - 1]>";
+                       ##warn "pre<$pre_ctx>\nline<$line>\nctx<$ctx>\nnext<$lines[$ctx_ln - 1]>\n";
 
-                       if ($ctx !~ /{\s*/ && $ctx_cnt > 0 && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {
-                               ERROR("That open brace { should be on the previous line\n" .
+                       if ($ctx !~ /{\s*/ && defined($lines[$ctx_ln -1]) && $lines[$ctx_ln - 1] =~ /^\+\s*{/) {
+                               ERROR("that open brace { should be on the previous line\n" .
                                        "$here\n$ctx\n$lines[$ctx_ln - 1]");
                        }
-                       if ($level == 0 && $ctx =~ /\)\s*\;\s*$/ && defined $lines[$ctx_ln - 1]) {
+                       if ($level == 0 && $pre_ctx !~ /}\s*while\s*\($/ &&
+                           $ctx =~ /\)\s*\;\s*$/ &&
+                           defined $lines[$ctx_ln - 1])
+                       {
                                my ($nlength, $nindent) = line_stats($lines[$ctx_ln - 1]);
                                if ($nindent > $indent) {
-                                       WARN("Trailing semicolon indicates no statements, indent implies otherwise\n" .
+                                       WARN("trailing semicolon indicates no statements, indent implies otherwise\n" .
                                                "$here\n$ctx\n$lines[$ctx_ln - 1]");
                                }
                        }
@@ -1200,7 +1249,7 @@ sub process {
 # check for initialisation to aggregates open brace on the next line
                if ($prevline =~ /$Declare\s*$Ident\s*=\s*$/ &&
                    $line =~ /^.\s*{/) {
-                       ERROR("That open brace { should be on the previous line\n" . $hereprev);
+                       ERROR("that open brace { should be on the previous line\n" . $hereprev);
                }
 
 #
@@ -1325,22 +1374,31 @@ sub process {
 # check for spaces between functions and their parentheses.
                while ($line =~ /($Ident)\s+\(/g) {
                        my $name = $1;
-                       my $ctx = substr($line, 0, $-[1]);
+                       my $ctx_before = substr($line, 0, $-[1]);
+                       my $ctx = "$ctx_before$name";
 
                        # Ignore those directives where spaces _are_ permitted.
-                       if ($name =~ /^(?:if|for|while|switch|return|volatile|__volatile__|__attribute__|format|__extension__|Copyright|case|__asm__)$/) {
+                       if ($name =~ /^(?:
+                               if|for|while|switch|return|case|
+                               volatile|__volatile__|
+                               __attribute__|format|__extension__|
+                               asm|__asm__)$/x)
+                       {
 
                        # cpp #define statements have non-optional spaces, ie
                        # if there is a space between the name and the open
                        # parenthesis it is simply not a parameter group.
-                       } elsif ($ctx =~ /^.\#\s*define\s*$/) {
+                       } elsif ($ctx_before =~ /^.\#\s*define\s*$/) {
+
+                       # cpp #elif statement condition may start with a (
+                       } elsif ($ctx =~ /^.\#\s*elif\s*$/) {
 
                        # If this whole things ends with a type its most
                        # likely a typedef for a function.
-                       } elsif ("$ctx$name" =~ /$Type$/) {
+                       } elsif ($ctx =~ /$Type$/) {
 
                        } else {
-                               WARN("no space between function name and open parenthesis '('\n" . $herecurr);
+                               WARN("space prohibited between function name and open parenthesis '('\n" . $herecurr);
                        }
                }
 # Check operator spacing.
@@ -1359,13 +1417,21 @@ sub process {
                        for (my $n = 0; $n < $#elements; $n += 2) {
                                $off += length($elements[$n]);
 
+                               # Pick up the preceeding and succeeding characters.
+                               my $ca = substr($opline, 0, $off);
+                               my $cc = '';
+                               if (length($opline) >= ($off + length($elements[$n + 1]))) {
+                                       $cc = substr($opline, $off + length($elements[$n + 1]));
+                               }
+                               my $cb = "$ca$;$cc";
+
                                my $a = '';
                                $a = 'V' if ($elements[$n] ne '');
                                $a = 'W' if ($elements[$n] =~ /\s$/);
                                $a = 'C' if ($elements[$n] =~ /$;$/);
                                $a = 'B' if ($elements[$n] =~ /(\[|\()$/);
                                $a = 'O' if ($elements[$n] eq '');
-                               $a = 'E' if ($elements[$n] eq '' && $n == 0);
+                               $a = 'E' if ($ca =~ /^\s*$/);
 
                                my $op = $elements[$n + 1];
 
@@ -1381,14 +1447,6 @@ sub process {
                                        $c = 'E';
                                }
 
-                               # Pick up the preceeding and succeeding characters.
-                               my $ca = substr($opline, 0, $off);
-                               my $cc = '';
-                               if (length($opline) >= ($off + length($elements[$n + 1]))) {
-                                       $cc = substr($opline, $off + length($elements[$n + 1]));
-                               }
-                               my $cb = "$ca$;$cc";
-
                                my $ctx = "${a}x${c}";
 
                                my $at = "(ctx:$ctx)";
@@ -1424,7 +1482,7 @@ sub process {
                                } elsif ($op eq ';') {
                                        if ($ctx !~ /.x[WEBC]/ &&
                                            $cc !~ /^\\/ && $cc !~ /^;/) {
-                                               ERROR("need space after that '$op' $at\n" . $hereptr);
+                                               ERROR("space required after that '$op' $at\n" . $hereptr);
                                        }
 
                                # // is a comment
@@ -1433,13 +1491,13 @@ sub process {
                                # -> should have no spaces
                                } elsif ($op eq '->') {
                                        if ($ctx =~ /Wx.|.xW/) {
-                                               ERROR("no spaces around that '$op' $at\n" . $hereptr);
+                                               ERROR("spaces prohibited around that '$op' $at\n" . $hereptr);
                                        }
 
                                # , must have a space on the right.
                                } elsif ($op eq ',') {
                                        if ($ctx !~ /.x[WEC]/ && $cc !~ /^}/) {
-                                               ERROR("need space after that '$op' $at\n" . $hereptr);
+                                               ERROR("space required after that '$op' $at\n" . $hereptr);
                                        }
 
                                # '*' as part of a type definition -- reported already.
@@ -1452,21 +1510,26 @@ sub process {
                                } elsif ($op eq '!' || $op eq '~' ||
                                         ($is_unary && ($op eq '*' || $op eq '-' || $op eq '&'))) {
                                        if ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
-                                               ERROR("need space before that '$op' $at\n" . $hereptr);
+                                               ERROR("space required before that '$op' $at\n" . $hereptr);
                                        }
                                        if ($ctx =~ /.xW/) {
-                                               ERROR("no space after that '$op' $at\n" . $hereptr);
+                                               ERROR("space prohibited after that '$op' $at\n" . $hereptr);
                                        }
 
                                # unary ++ and unary -- are allowed no space on one side.
                                } elsif ($op eq '++' or $op eq '--') {
-                                       if ($ctx !~ /[WOBC]x[^W]/ && $ctx !~ /[^W]x[WOBEC]/) {
-                                               ERROR("need space one side of that '$op' $at\n" . $hereptr);
+                                       if ($ctx !~ /[WEOBC]x[^W]/ && $ctx !~ /[^W]x[WOBEC]/) {
+                                               ERROR("space required one side of that '$op' $at\n" . $hereptr);
+                                       }
+                                       if ($ctx =~ /Wx[BE]/ ||
+                                           ($ctx =~ /Wx./ && $cc =~ /^;/)) {
+                                               ERROR("space prohibited before that '$op' $at\n" . $hereptr);
                                        }
-                                       if ($ctx =~ /WxB/ || ($ctx =~ /Wx./ && $cc =~ /^;/)) {
-                                               ERROR("no space before that '$op' $at\n" . $hereptr);
+                                       if ($ctx =~ /ExW/) {
+                                               ERROR("space prohibited after that '$op' $at\n" . $hereptr);
                                        }
 
+
                                # << and >> may either have or not have spaces both sides
                                } elsif ($op eq '<<' or $op eq '>>' or
                                         $op eq '&' or $op eq '^' or $op eq '|' or
@@ -1474,7 +1537,7 @@ sub process {
                                         $op eq '*' or $op eq '/' or
                                         $op eq '%')
                                {
-                                       if ($ctx !~ /VxV|WxW|VxE|WxE|VxO|Cx.|.xC/) {
+                                       if ($ctx =~ /Wx[^WCE]|[^WCE]xW/) {
                                                ERROR("need consistent spacing around '$op' $at\n" .
                                                        $hereptr);
                                        }
@@ -1484,7 +1547,7 @@ sub process {
                                        # Ignore email addresses <foo@bar>
                                        if (!($op eq '<' && $cb =~ /$;\S+\@\S+>/) &&
                                            !($op eq '>' && $cb =~ /<\S+\@\S+$;/)) {
-                                               ERROR("need spaces around that '$op' $at\n" . $hereptr);
+                                               ERROR("spaces required around that '$op' $at\n" . $hereptr);
                                        }
                                }
                                $off += length($elements[$n + 1]);
@@ -1514,31 +1577,31 @@ sub process {
 #need space before brace following if, while, etc
                if (($line =~ /\(.*\){/ && $line !~ /\($Type\){/) ||
                    $line =~ /do{/) {
-                       ERROR("need a space before the open brace '{'\n" . $herecurr);
+                       ERROR("space required before the open brace '{'\n" . $herecurr);
                }
 
 # closing brace should have a space following it when it has anything
 # on the line
                if ($line =~ /}(?!(?:,|;|\)))\S/) {
-                       ERROR("need a space after that close brace '}'\n" . $herecurr);
+                       ERROR("space required after that close brace '}'\n" . $herecurr);
                }
 
 # check spacing on square brackets
                if ($line =~ /\[\s/ && $line !~ /\[\s*$/) {
-                       ERROR("no space after that open square bracket '['\n" . $herecurr);
+                       ERROR("space prohibited after that open square bracket '['\n" . $herecurr);
                }
                if ($line =~ /\s\]/) {
-                       ERROR("no space before that close square bracket ']'\n" . $herecurr);
+                       ERROR("space prohibited before that close square bracket ']'\n" . $herecurr);
                }
 
 # check spacing on paretheses
                if ($line =~ /\(\s/ && $line !~ /\(\s*(?:\\)?$/ &&
                    $line !~ /for\s*\(\s+;/) {
-                       ERROR("no space after that open parenthesis '('\n" . $herecurr);
+                       ERROR("space prohibited after that open parenthesis '('\n" . $herecurr);
                }
                if ($line =~ /(\s+)\)/ && $line !~ /^.\s*\)/ &&
                    $line !~ /for\s*\(.*;\s+\)/) {
-                       ERROR("no space before that close parenthesis ')'\n" . $herecurr);
+                       ERROR("space prohibited before that close parenthesis ')'\n" . $herecurr);
                }
 
 #goto labels aren't indented, allow a single space however
@@ -1549,7 +1612,7 @@ sub process {
 
 # Need a space before open parenthesis after if, while etc
                if ($line=~/\b(if|while|for|switch)\(/) {
-                       ERROR("need a space before the open parenthesis '('\n" . $herecurr);
+                       ERROR("space required before the open parenthesis '('\n" . $herecurr);
                }
 
 # Check for illegal assignment in if conditional.
@@ -1562,10 +1625,12 @@ sub process {
 
                        # Find out what is on the end of the line after the
                        # conditional.
-                       substr($s, 0, length($c)) = '';
+                       substr($s, 0, length($c), '');
                        $s =~ s/\n.*//g;
                        $s =~ s/$;//g;  # Remove any comments
-                       if (length($c) && $s !~ /^\s*({|;|)\s*\\*\s*$/) {
+                       if (length($c) && $s !~ /^\s*({|;|)\s*\\*\s*$/ &&
+                           $c !~ /^.\#\s*if/)
+                       {
                                ERROR("trailing statements should be on next line\n" . $herecurr);
                        }
                }
@@ -1607,7 +1672,7 @@ sub process {
 
                        # Find out what is on the end of the line after the
                        # conditional.
-                       substr($s, 0, length($c)) = '';
+                       substr($s, 0, length($c), '');
                        $s =~ s/\n.*//g;
 
                        if ($s =~ /^\s*;/) {
@@ -1631,7 +1696,7 @@ sub process {
                if ($tree && $rawline =~ m{^.\#\s*include\s*\<asm\/(.*)\.h\>}) {
                        my $checkfile = "$root/include/linux/$1.h";
                        if (-f $checkfile && $1 ne 'irq.h') {
-                               CHK("Use #include <linux/$1.h> instead of <asm/$1.h>\n" .
+                               WARN("Use #include <linux/$1.h> instead of <asm/$1.h>\n" .
                                        $herecurr);
                        }
                }
@@ -1692,15 +1757,24 @@ sub process {
                        if ($#chunks > 0 && $level == 0) {
                                my $allowed = 0;
                                my $seen = 0;
-                               my $herectx = $here . "\n";;
+                               my $herectx = $here . "\n";
                                my $ln = $linenr - 1;
                                for my $chunk (@chunks) {
                                        my ($cond, $block) = @{$chunk};
 
-                                       $herectx .= "$rawlines[$ln]\n[...]\n";
+                                       # If the condition carries leading newlines, then count those as offsets.
+                                       my ($whitespace) = ($cond =~ /^((?:\s*\n[+-])*\s*)/s);
+                                       my $offset = statement_rawlines($whitespace) - 1;
+
+                                       #print "COND<$cond> whitespace<$whitespace> offset<$offset>\n";
+
+                                       # We have looked at and allowed this specific line.
+                                       $suppress_ifbraces{$ln + $offset} = 1;
+
+                                       $herectx .= "$rawlines[$ln + $offset]\n[...]\n";
                                        $ln += statement_rawlines($block) - 1;
 
-                                       substr($block, 0, length($cond)) = '';
+                                       substr($block, 0, length($cond), '');
 
                                        $seen++ if ($block =~ /^\s*{/);
 
@@ -1721,16 +1795,10 @@ sub process {
                                if ($seen && !$allowed) {
                                        WARN("braces {} are not necessary for any arm of this statement\n" . $herectx);
                                }
-                               # Either way we have looked over this whole
-                               # statement and said what needs to be said.
-                               $suppress_ifbraces = $endln;
                        }
                }
-               if ($linenr > $suppress_ifbraces &&
+               if (!defined $suppress_ifbraces{$linenr - 1} &&
                                        $line =~ /\b(if|while|for|else)\b/) {
-                       my ($level, $endln, @chunks) =
-                               ctx_statement_full($linenr, $realcnt, $-[0]);
-
                        my $allowed = 0;
 
                        # Check the pre-context.
@@ -1738,10 +1806,15 @@ sub process {
                                #print "APW: ALLOWED: pre<$1>\n";
                                $allowed = 1;
                        }
+
+                       my ($level, $endln, @chunks) =
+                               ctx_statement_full($linenr, $realcnt, $-[0]);
+
                        # Check the condition.
                        my ($cond, $block) = @{$chunks[0]};
+                       #print "CHECKING<$linenr> cond<$cond> block<$block>\n";
                        if (defined $cond) {
-                               substr($block, 0, length($cond)) = '';
+                               substr($block, 0, length($cond), '');
                        }
                        if (statement_lines($cond) > 1) {
                                #print "APW: ALLOWED: cond<$cond>\n";
@@ -1759,7 +1832,7 @@ sub process {
                        if (defined $chunks[1]) {
                                my ($cond, $block) = @{$chunks[1]};
                                if (defined $cond) {
-                                       substr($block, 0, length($cond)) = '';
+                                       substr($block, 0, length($cond), '');
                                }
                                if ($block =~ /^\s*\{/) {
                                        #print "APW: ALLOWED: chunk-1 block<$block>\n";
@@ -1882,6 +1955,28 @@ sub process {
                if ($line =~ /__FUNCTION__/) {
                        WARN("__func__ should be used instead of gcc specific __FUNCTION__\n"  . $herecurr);
                }
+
+# check for semaphores used as mutexes
+               if ($line =~ /\b(DECLARE_MUTEX|init_MUTEX)\s*\(/) {
+                       WARN("mutexes are preferred for single holder semaphores\n" . $herecurr);
+               }
+# check for semaphores used as mutexes
+               if ($line =~ /\binit_MUTEX_LOCKED\s*\(/) {
+                       WARN("consider using a completion\n" . $herecurr);
+               }
+# recommend strict_strto* over simple_strto*
+               if ($line =~ /\bsimple_(strto.*?)\s*\(/) {
+                       WARN("consider using strict_$1 in preference to simple_$1\n" . $herecurr);
+               }
+
+# use of NR_CPUS is usually wrong
+# ignore definitions of NR_CPUS and usage to define arrays as likely right
+               if ($line =~ /\bNR_CPUS\b/ &&
+                   $line !~ /^.#\s*define\s+NR_CPUS\s+/ &&
+                   $line !~ /^.\s*$Declare\s.*\[[^\]]*NR_CPUS[^\]]*\]/)
+               {
+                       WARN("usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc\n" . $herecurr);
+               }
        }
 
        # If we have no input at all, then there is nothing to report on