#!/usr/bin/perl -w

#use strict;
use vars qw($top %used_defines %set_defines);
use File::Find;
use Getopt::Long;
use Config;

#
# Do a perl check for version >= 5.005.  See 'gpt-translate-interpreter' should you
# need to alter the invocation path to a valid perl interpreter in the GPT front-end
# programs.
#

if ( ! ( defined eval "require 5.005" ) )
{
    die "GPT requires at least Perl version 5.005";
}

my $gpath = $ENV{GPT_LOCATION};
if (!defined($gpath))
{
  $gpath = $ENV{GLOBUS_LOCATION};

}
if (!defined($gpath))
{
   die "GPT_LOCATION or GLOBUS_LOCATION needs to be set before running this script"
}

@INC = ("$gpath/lib/perl", "$gpath/lib/perl/$Config{'archname'}", @INC);

if ( ! ( defined eval "require Grid::GPT::GPTObject" ) )
{
    die("$gpath does not appear to hold a valid GPT installation\n");
}

require Pod::Usage;

$top = ".";

my ($config, $disable_undefs);
my $verbose = 0;
my ($help, $man, $version);

# sub pod2usage {
#   my $ex = shift;
#   print "gpt_undefines [-srcdir=PATH -config -disable-undefs -verbose -help] headers containing defines\n";
#   exit $ex;
# }

GetOptions( 'srcdir=s' => \$top, 'config' => \$config, 
            'disable-undefs' => \$disable_undefs, 
	    'verbose=i' => \$verbose, 'help' => \$help,'version' => \$version)
  or Pod::Usage::pod2usage(1);

Pod::Usage::pod2usage(0) if $help;
require Grid::GPT::GPTIdentity;
Grid::GPT::GPTIdentity::print_gpt_version() if defined $version;



for my $h (@ARGV) {
  scan_for_def_cmds($h, 1);
}


find(\&globus_sh, $top);
my $word;

if (defined($config)) {

  for $word (sort keys %used_defines) {
    
    next if (defined($set_defines{$word}));
    
    print "#ifndef $word\n";
    print "#undef $word\n";
    print "#endif\n";
  }

} else {

  for $word (sort keys %used_defines) {
    
    next if (defined($set_defines{$word}));
    
    print "$word :\n";
    for (sort keys %{$used_defines{$word}}) {
      print "\t$_\n";
    }
    print "\n\n";
  }
}


sub globus_sh
  {
    if (! -f "$_") {
      return;
    }
    if (! -T "$_") {
      return;
    }
    
    if (!/\.[Cch]$/) {
      return;
    }
    if (/config\.h/) {
      return;
    }
    my $file = $_;
    scan_for_def_cmds($file);
    $_ = $file;
  }

sub scan_for_def_cmds 
{
  my ($file, $just_defines) = @_;
  open (FILE,"<$file");
  my $line_continuation = "no";
  my $isifdef = "no";
  while (<FILE>) {
    my $macro_buffer;

    # process a line continuation    
    if ($line_continuation eq "yes") {
      $macro_buffer .= $_;
      $line_continuation = "no";
    }
    
    # scan for #if?def's
    if (/^\s*\#if/) {
      if (m!\\$!) {
        $line_continuation = "yes";
      }
      $macro_buffer = $_;
      $isifdef = "yes";
      next if defined($just_defines);
    }
    
    # scan for #define's
    if (/^\s*\#def/) {
      if (m!\\$!) {
        $line_continuation = "yes";
      }
      $macro_buffer = $_;
      $isifdef = "no";
    }
    
    # scan for #undef's including those commented out
    if (m!^/\*\s*\#undef! and ! defined($disable_undefs)) {
      # remove comment so that line doesn't get stripped
      s!^/\*!!;
      if (m!\\$!) {
        $line_continuation = "yes";
      }
      $macro_buffer = $_;
      $isifdef = "no";
    }
    
    if (defined($macro_buffer)) {
      #	print $macro_buffer;
      my $keywrds = { if =>1,
                      defined =>1,
                      ifdef =>1,
                      ifndef =>1,
                      define =>1,
                      0 => 1,
                      1 => 1
                    };
      #	print $macro_buffer;

      # Remove comments for the buffer
      $macro_buffer =~ s!/\*.+$!!g;

      #	print $macro_buffer;
      
      # extract all of the words out of the buffer
      while ($macro_buffer =~ m/(\w+)/g) {
        my $word = $1;
        
        # skip C keywords
        next if (defined($keywrds->{$word}));
        
        # decide which hash to put the word in.
        my $wordlist = \%set_defines;
        $wordlist = \%used_defines if ($isifdef eq "yes");
        
        # create the has if it doesn't exist
        if (!defined($wordlist->{$word})) {
          $wordlist->{$word} = {};
        }
        
        # fill in the hash entry
        my $fullname = $file;
        if (defined($File::Find::name)) {
          $fullname = $File::Find::name;
          $fullname =~ s!$top!!;
        }
        $wordlist->{$word}->{$fullname} = 1;
      }
    }
  }
  close FILE;
  
}

=head1 NAME

B<gpt_undefines> - Generate a list of preprocessor macros that are not defined.

=head1 SYNOPSIS

gpt_undefines [-srcdir=PATH -config -disable-undefs -verbose -help] headers containing defines

=head1 DESCRIPTION

B<gpt_undefines> Generates a list of preprocessor macros that are not
defined internally in the source code.  Macros that are defined in the
header files listed during B<gpt_undefines>'s invocation will also be
excluded.

=head1 OPTIONS

=over 4

=item -srcdir=PATH

Use PATH as the directory containing the source code.  Source code in
the entire directory tree will be scanned. Default PATH is the
directory B<gpt_undefines> was invoked in.

=item -config

Prints the list out in a format that can be pasted into an installable
header file.

=item -disable-undefs

Do not count commented out undefines as a define. This technique is
used by autoconf to indicate a negative test result.  Example:

   /* #undef HAVE_TCP_FASTACK */

=back

=head1 Managing Autoconf defines.

By default the defines tested for by the configure script are stored
in a file called B<config.h>.  This file should never be installed. to
add autoconf defines to config.h simply add the define in the
following format to the file acconfig.h:

   #undef AUTOCONF_DEFINE

acconfig.h is tranformed into a config.h.in by the script
B<autoheader>.  Then the configure script transform it into config.h.

A problem occurs when the autoconf defines are used in installed
header files.  In this case the defines should be put in an
installable header file using the following format:

   #ifndef AUTOCONF_DEFINE
   #undef AUTOCONF_DEFINE
   #endif

=head1 SEE ALSO

autoconf(1) autoheader(1) 

=head1 AUTHOR

Michael Bletzinger E<lt>mbletzin.ncsa.uiuc.eduE<gt> and Eric Blau
E<lt>eblau.ncsa.uiuc.eduE<gt>

=cut