[Android WebView] Avoid detecting '(c)' as a copyright sign in lists.

android_webview/tools/find_copyrights.pl

 #!/usr/bin/perl -w
 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Use: find_copyrights.pl <start-from> [exclude-dir ...]
 
 use strict;
 use warnings;
 use File::Basename;
 
 sub check_is_generated_file($);
-sub parse_copyright($);
+sub start_copyright_parsing();
 
 my $progname = basename($0);
 
 my $root_dir = shift @ARGV;
 my @find_args = ();
 while (@ARGV) {
     my $path = shift @ARGV;
     push @find_args, qw'-not ( -path', "*/$path/*", qw'-prune )'
 }
 push @find_args, qw(-follow -type f -print);
 
 open FIND, '-|', 'find', $root_dir, @find_args
             or die "$progname: Couldn't exec find: $!\n";
 my $check_regex = '\.(asm|c(c|pp|xx)?|h(h|pp|xx)?|p(l|m)|xs|sh|php|py(|x)' .
     '|rb|idl|java|el|sc(i|e)|cs|pas|inc|js|pac|html|dtd|xsl|mod|mm?' .
     '|tex|mli?)$';
 my @files = ();
 while (<FIND>) {
     chomp;
     push @files, $_ unless (-z $_ || !m%$check_regex%);
 }
 close FIND;
 
 my $generated_file_scan_boundary = 25;
 while (@files) {
     my $file = shift @files;
     my $file_header = '';
     my %copyrights;
     open (F, "<$file") or die "$progname: Unable to access $file\n";
+    my $parse_copyright = start_copyright_parsing();
     while (<F>) {
         $file_header .= $_ unless $. > $generated_file_scan_boundary;
-        my $copyright_match = parse_copyright($_);
+        my $copyright_match = $parse_copyright->($_, $.);
         if ($copyright_match) {
             $copyrights{lc("$copyright_match")} = "$copyright_match";
         }
     }
     close(F);
     my $copyright = join(" / ", values %copyrights);
     print "$file\t";
     if (check_is_generated_file($file_header)) {
         print "GENERATED FILE";
     } else {
@@ skipping 18 matching lines @@
     if (index($license, 'DO NOT EDIT') != -1 ||
         index($license, 'DO NOT DELETE') != -1 ||
         index($license, 'GENERATED') != -1) {
         return ($license =~ /(All changes made in this file will be lost' .
             'DO NOT (EDIT|delete this file)|Generated (at|automatically|data)' .
             '|Automatically generated|\Wgenerated\s+(?:\w+\s+)*file\W)/i);
     }
     return 0;
 }
 
-sub parse_copyright($) {
-    my $line = $_[0];
-    # Remove C / C++ strings to avoid false positives.
-    if (index($line, '"') != -1) {
-        $line =~ s/"[^"\\]*(?:\\.[^"\\]*)*"//g;
+sub are_within_increasing_progression($$$) {
+    my $delta = $_[0] - $_[1];
+    return $delta >= 0 && $delta <= $_[2];
+}
+
+sub start_copyright_parsing() {
+    my $max_line_numbers_proximity = 3;
+    # Set up the defaults the way that proximity checks will not succeed.
+    my $last_a_item_line_number = -200;
+    my $last_b_item_line_number = -100;
+
+    return sub {
+        my $line = $_[0];
+        my $line_number = $_[1];
+
+        # Remove C / C++ strings to avoid false positives.
+        if (index($line, '"') != -1) {
+            $line =~ s/"[^"\\]*(?:\\.[^"\\]*)*"//g;
+        }
+
+        my $uc_line = uc($line);
+
+        # Record '(a)' and '(b)' last occurences in C++ comments.
+        my $cpp_comment_idx = index($uc_line, '//');
+        if ($cpp_comment_idx != -1) {
+            if (index($uc_line, '(A)') > $cpp_comment_idx) {
+                $last_a_item_line_number = $line_number;
+            }
+            if (index($uc_line, '(B)') > $cpp_comment_idx) {
+                $last_b_item_line_number = $line_number;
+            }
+        }
+
+        # Fast bailout, uses the same patterns as the regexp.
+        if (index($uc_line, 'COPYRIGHT') == -1 &&
+            index($uc_line, 'COPR.') == -1 &&
+            index($uc_line, '\x{00a9}') == -1 &&
+            index($uc_line, '\xc2\xa9') == -1) {
+
+            my $c_item_index = index($uc_line, '(C)');
+            return '' if ($c_item_index == -1);
+            # Filter out 'c' used as a list item inside C++ comments.
+            # E.g. "// blah-blah (a) blah\n// blah-blah (b) and (c) blah"
+            if ($c_item_index > $cpp_comment_idx &&
+                are_within_increasing_progression(
+                    $line_number,
+                    $last_b_item_line_number,
+                    $max_line_numbers_proximity) &&
+                are_within_increasing_progression(
+                    $last_b_item_line_number,
+                    $last_a_item_line_number,
+                    $max_line_numbers_proximity)) {
+                return '';
+            }
+        }
+
+        my $copyright_indicator_regex =
+            '(?:copyright|copr\.|\x{00a9}|\xc2\xa9|\(c\))';
+        my $copyright_disindicator_regex =
+            '\b(?:info(?:rmation)?|notice|and|or)\b';
+
+        my $copyright = '';
+        if ($line =~ m%\W$copyright_indicator_regex(?::\s*|\s+)(\w.*)$%i) {
+            my $match = $1;
+            if ($match !~ m%^\s*$copyright_disindicator_regex%i) {
+                $match =~ s/([,.])?\s*$//;
+                $match =~ s/$copyright_indicator_regex//ig;
+                $match =~ s/^\s+//;
+                $match =~ s/\s{2,}/ /g;
+                $match =~ s/\\@/@/g;
+                $copyright = $match;
+            }
+        }
+
+        return $copyright;
     }
-
-    my $uc_line = uc($line);
-    # Fast bailout, uses the same patterns as the regexp.
-    return '' if (index($uc_line, 'COPYRIGHT') == -1 &&
-                  index($uc_line, 'COPR.') == -1 &&
-                  index($uc_line, '\x{00a9}') == -1 &&
-                  index($uc_line, '\xc2\xa9') == -1 &&
-                  index($uc_line, '(C)') == -1);
-
-    my $copyright_indicator_regex =
-        '(?:copyright|copr\.|\x{00a9}|\xc2\xa9|\(c\))';
-    my $copyright_disindicator_regex =
-        '\b(?:info(?:rmation)?|notice|and|or)\b';
-
-    my $copyright = '';
-    if ($line =~ m%\W$copyright_indicator_regex(?::\s*|\s+)(\w.*)$%i) {
-        my $match = $1;
-        if ($match !~ m%^\s*$copyright_disindicator_regex%i) {
-            $match =~ s/([,.])?\s*$//;
-            $match =~ s/$copyright_indicator_regex//ig;
-            $match =~ s/^\s+//;
-            $match =~ s/\s{2,}/ /g;
-            $match =~ s/\\@/@/g;
-            $copyright = $match;
-        }
-    }
-
-    return $copyright;
 }