--- a/libtommath/dep.pl	Thu Feb 08 22:21:47 2018 +0800
+++ b/libtommath/dep.pl	Thu Feb 08 23:11:40 2018 +0800
@@ -2,122 +2,126 @@
 #
 # Walk through source, add labels and make classes
 #
-#use strict;
+use strict;
+use warnings;
 
 my %deplist;
 
 #open class file and write preamble 
-open(CLASS, ">tommath_class.h") or die "Couldn't open tommath_class.h for writing\n";
-print CLASS "#if !(defined(LTM1) && defined(LTM2) && defined(LTM3))\n#if defined(LTM2)\n#define LTM3\n#endif\n#if defined(LTM1)\n#define LTM2\n#endif\n#define LTM1\n\n#if defined(LTM_ALL)\n";
+open(my $class, '>', 'tommath_class.h') or die "Couldn't open tommath_class.h for writing\n";
+print {$class} "#if !(defined(LTM1) && defined(LTM2) && defined(LTM3))\n#if defined(LTM2)\n#define LTM3\n#endif\n#if defined(LTM1)\n#define LTM2\n#endif\n#define LTM1\n\n#if defined(LTM_ALL)\n";
 
-foreach my $filename (glob "bn*.c") {
+foreach my $filename (glob 'bn*.c') {
    my $define = $filename;
 
-print "Processing $filename\n";
+   print "Processing $filename\n";
 
-   # convert filename to upper case so we can use it as a define 
+   # convert filename to upper case so we can use it as a define
    $define =~ tr/[a-z]/[A-Z]/;
    $define =~ tr/\./_/;
-   print CLASS "#define $define\n";
+   print {$class} "#define $define\n";
 
    # now copy text and apply #ifdef as required 
    my $apply = 0;
-   open(SRC, "<$filename");
-   open(OUT, ">tmp");
+   open(my $src, '<', $filename);
+   open(my $out, '>', 'tmp');
 
    # first line will be the #ifdef
-   my $line = <SRC>;
+   my $line = <$src>;
    if ($line =~ /include/) {
-      print OUT $line;
+      print {$out} $line;
    } else {
-      print OUT "#include <tommath.h>\n#ifdef $define\n$line";
+      print {$out} "#include <tommath.h>\n#ifdef $define\n$line";
       $apply = 1;
    }
-   while (<SRC>) {
+   while (<$src>) {
       if (!($_ =~ /tommath\.h/)) {
-         print OUT $_;
+         print {$out} $_;
       }
    }
    if ($apply == 1) {
-      print OUT "#endif\n";
+      print {$out} "#endif\n";
    }
-   close SRC;
-   close OUT;
+   close $src;
+   close $out;
 
-   unlink($filename);
-   rename("tmp", $filename);
+   unlink $filename;
+   rename 'tmp', $filename;
 }
-print CLASS "#endif\n\n";
+print {$class} "#endif\n\n";
 
 # now do classes 
 
-foreach my $filename (glob "bn*.c") {
-   open(SRC, "<$filename") or die "Can't open source file!\n"; 
+foreach my $filename (glob 'bn*.c') {
+   open(my $src, '<', $filename) or die "Can't open source file!\n";
 
    # convert filename to upper case so we can use it as a define 
    $filename =~ tr/[a-z]/[A-Z]/;
    $filename =~ tr/\./_/;
 
-   print CLASS "#if defined($filename)\n";
+   print {$class} "#if defined($filename)\n";
    my $list = $filename;
 
    # scan for mp_* and make classes
-   while (<SRC>) {
+   while (<$src>) {
       my $line = $_;
       while ($line =~ m/(fast_)*(s_)*mp\_[a-z_0-9]*/) {
           $line = $';
           # now $& is the match, we want to skip over LTM keywords like
           # mp_int, mp_word, mp_digit
-          if (!($& eq "mp_digit") && !($& eq "mp_word") && !($& eq "mp_int") && !($& eq "mp_min_u32")) {
+          if (!($& eq 'mp_digit') && !($& eq 'mp_word') && !($& eq 'mp_int') && !($& eq 'mp_min_u32')) {
              my $a = $&;
              $a =~ tr/[a-z]/[A-Z]/;
-             $a = "BN_" . $a . "_C";
+             $a = 'BN_' . $a . '_C';
              if (!($list =~ /$a/)) {
-                print CLASS "   #define $a\n";
+                print {$class} "   #define $a\n";
              }
-             $list = $list . "," . $a;
+             $list = $list . ',' . $a;
           }
       }
    }
-   @deplist{$filename} = $list;
+   $deplist{$filename} = $list;
 
-   print CLASS "#endif\n\n";
-   close SRC;
+   print {$class} "#endif\n\n";
+   close $src;
 }
 
-print CLASS "#ifdef LTM3\n#define LTM_LAST\n#endif\n#include <tommath_superclass.h>\n#include <tommath_class.h>\n#else\n#define LTM_LAST\n#endif\n";
-close CLASS;
+print {$class} "#ifdef LTM3\n#define LTM_LAST\n#endif\n#include <tommath_superclass.h>\n#include <tommath_class.h>\n#else\n#define LTM_LAST\n#endif\n";
+close $class;
 
 #now let's make a cool call graph... 
 
-open(OUT,">callgraph.txt");
-$indent = 0;
-foreach (keys %deplist) {
-   $list = "";
-   draw_func(@deplist{$_});
-   print OUT "\n\n";
+open(my $out, '>', 'callgraph.txt');
+my $indent = 0;
+my $list;
+foreach (sort keys %deplist) {
+   $list = '';
+   draw_func($deplist{$_});
+   print {$out} "\n\n";
 }
-close(OUT);
+close $out;
 
-sub draw_func()
+sub draw_func
 {
-   my @funcs = split(",", $_[0]);
-   if ($list =~ /@funcs[0]/) {
+   my @funcs = split ',', $_[0];
+   if ($list =~ /$funcs[0]/) {
       return;
    } else {
-      $list = $list . @funcs[0];
+      $list = $list . $funcs[0];
    }
-   if ($indent == 0) { }
-   elsif ($indent >= 1) { print OUT "|   " x ($indent - 1) . "+--->"; }
-   print OUT @funcs[0] . "\n";   
+   if ($indent == 0) {
+   } elsif ($indent >= 1) {
+      print {$out} '|   ' x ($indent - 1) . '+--->';
+   }
+   print {$out} $funcs[0] . "\n";
    shift @funcs;
-      my $temp = $list;
+   my $temp = $list;
    foreach my $i (@funcs) {
       ++$indent;
-      draw_func(@deplist{$i});
+      draw_func($deplist{$i}) if exists $deplist{$i};
       --$indent;
    }
-      $list = $temp;
+   $list = $temp;
+   return;
 }
 
-