Updated Errors.cpp-generating program: stopped use of external DLL, added parameters and help and file/LOC count

This was SVN commit r2558.

build/errorlist/errorlist.pl

@@ -1,14 +1,40 @@
 #!perl -w
 
+++$|;
+END { print "\n\nPress enter to exit.\n"; <STDIN> }
+
 use strict;
 use warnings;
 
-my $source = '../../source';
+my ($source, $output);
+
+for (@ARGV) {
+  # Note to self: "perl errorlist.pl --source=../../source/i18n --output=../../source/i18n/tests/ps/Errors.cpp"
+  if (/[-\/]\?|--\?|--help/) {
+    print <<EOH;
+$0 parameters:
+  --source=../../source               - root directory for source code
+  --output=../../source/ps/Errors.cpp - output file to generate
+  --help                              - route to enlightenment
+EOH
+    exit;
+  } elsif (/^--source="?(.*?)"?$/) {
+    $source = $1;
+  } elsif (/^--output="?(.*?)"?$/) {
+    $output = $1;
+  }
+}
+
+$source ||= '../../source';
+$output ||= "$source/ps/Errors.cpp";
+
+print "Reading files from $source... ";
 
 my (%topgroups, %groups, %types);
 
 my @files = cpp_files("$source/");
 
+my $loc = 0;
 for (@files) {
   open my $f, $_ or die "Error opening file '$_' ($!)";
   while (<$f>) {
@@ -21,15 +47,22 @@ for (@files) {
         $types{join '~', split /,\s*/, $1} = 1;
       }
     }
+    ++$loc;
   }
 }
 
+# Add commas to number in groups of three
+1 while $loc =~ s/(\d+)(\d{3})/$1,$2/;
+
+print "(".@files." files read - $loc lines of code)\n";
+print "Generating $output... ";
+
 # Add "PSERROR_Error_InvalidError", so that an error to throw when being
 # told to throw an error that doesn't exist exists.
 $topgroups{Error} = 1;
 $types{'Error~InvalidError'} = 1;
 
-open my $out, '>', "$source/ps/Errors.cpp" or die "Error opening $source/ps/Errors.cpp ($!)";
+open my $out, '>', "$output" or die "Error opening $output ($!)";
 
 print $out <<'.';
 // Auto-generated by errorlist.pl - do not edit.
@@ -199,6 +232,7 @@ print $out <<".";
 }
 .
 
+print "Finished.\n";
 
 sub cpp_files {
   opendir my $d, $_[0] or die "Error opening directory '$_[0]' ($!)";