#!/usr/bin/perl

# RPM (and its source code) is covered under two separate licenses.

# The entire code base may be distributed under the terms of the GNU
# General Public License (GPL), which appears immediately below.
# Alternatively, all of the source code in the lib subdirectory of the
# RPM source code distribution as well as any code derived from that
# code may instead be distributed under the GNU Library General Public
# License (LGPL), at the choice of the distributor. The complete text
# of the LGPL appears at the bottom of this file.

# This alternatively is allowed to enable applications to be linked
# against the RPM library (commonly called librpm) without forcing
# such applications to be distributed under the GPL.

# Any questions regarding the licensing of RPM should be addressed to
# Erik Troan <ewt@redhat.com>.

# a simple makedepend like script for perl.

# To save development time I do not parse the perl grammar but
# instead just lex it looking for what I want.  I take special care to
# ignore comments and pod's.

# It would be much better if perl could tell us the dependencies of a
# given script.

# The filenames to scan are either passed on the command line or if
# that is empty they are passed via stdin.

# If there are strings in the file which match the pattern
#     m/^\s*\$RPM_Requires\s*=\s*["'](.*)['"]/i
# then these are treated as additional names which are required by the
# file and are printed as well.

# I plan to rewrite this in C so that perl is not required by RPM at
# build time.

# by Ken Estes Mail.com kestes@staff.mail.com

$HAVE_VERSION = 0;
eval { require version; $HAVE_VERSION = 1; };

use File::Basename;
my $dir = dirname($0);
$HAVE_PROV = 0;
if ( -e "$dir/perl.prov" ) {
  $HAVE_PROV = 1;
  $prov_script = "$dir/perl.prov";
}

if ("@ARGV") {
  foreach my $file (@ARGV) {
    process_file($file);
    process_file_provides($file);
    compute_global_requires();
  }
} else {

  # notice we are passed a list of filenames NOT as common in unix the
  # contents of the file.

  foreach my $file (<>) {
    process_file($file);
    process_file_provides($file);
    compute_global_requires();
  }
}


foreach $perlver (sort keys %perlreq) {
  print "perl >= $perlver\n";
}

foreach my $module (sort keys %global_require) {
  if (length($global_require{$module}) == 0) {
    print "perl($module)\n";
  } else {

    # I am not using rpm3.0 so I do not want spaces around my
    # operators. Also I will need to change the processing of the
    # $RPM_* variable when I upgrade.

    print "perl($module) >= $global_require{$module}\n";
  }
}

exit 0;

sub compute_global_requires {
 
# restrict require_removable to all non provided by the file
  foreach my $moduler (sort keys %require_removable) {
    if (exists $provide{$moduler} && length($require_removable{$moduler}) == 0) {
      $require_removable = delete $require_removable{$moduler};
    } 
  }
# store requires to global_requires
  foreach my $module (sort keys %require) {
    my $oldver = $global_require{$module};
    my $newver = $require{$module};
    if ($oldver) {
      $global_require{$module} = $newver
        if ($HAVE_VERSION && $newver && version->new($oldver) < $newver);
    } else {
      $global_require{$module} = $newver;
    }
  }

# store requires_removable to global_requires
  foreach my $module (sort keys %require_removable) {
    my $oldver = $global_require{$module};
    my $newver = $require_removable{$module};
    if ($oldver) {
      $global_require{$module} = $newver
        if ($HAVE_VERSION && $newver && version->new($oldver) < $newver);
    } else {
      $global_require{$module} = $newver;
    }
  }
# remove all local requires and provides
  undef %require;
  undef %require_removable;
  undef %provide;
}

sub add_require {
  my ($module, $newver) = @_;
  my $oldver = $require{$module};
  if ($oldver) {
    $require{$module} = $newver
      if ($HAVE_VERSION && $newver && version->new($oldver) < $newver);
  }
  else {
    $require{$module} = $newver;
  }
}

sub add_require_removable {
  my ($module, $newver) = @_;
  my $oldver = $require_removable{$module};
  if ($oldver) {
    $require_removable{$module} = $newver
      if ($HAVE_VERSION && $newver && version->new($oldver) < $newver);
  }
  else {
    $require_removable{$module} = $newver;
  }
}

sub process_file {

  my ($file) = @_;
  chomp $file;

  if (!open(FILE, $file)) {
    warn("$0: Warning: Could not open file '$file' for reading: $!\n");
    return;
  }

  while (<FILE>) {

    # skip the "= <<" block

    if (m/^\s*(?:my\s*)?\$(?:.*)\s*=\s*<<\s*(["'`])(.+?)\1/ ||
        m/^\s*(?:my\s*)?\$(.*)\s*=\s*<<(\w+)\s*;/) {
      $tag = $2;
      while (<FILE>) {
        chomp;
        ( $_ eq $tag ) && last;
      }
      $_ = <FILE>;
    }

    # skip q{} quoted sections - just hope we don't have curly brackets
    # within the quote, nor an escaped hash mark that isn't a comment
    # marker, such as occurs right here. Draw the line somewhere.
    if ( m/^.*\Wq[qxwr]?\s*([{([#|\/])[^})\]#|\/]*$/ && ! m/^\s*(require|use)\s/ ) {
      $tag = $1;
      $tag =~ tr/{\(\[\#|\//})]#|\//;
      $tag = quotemeta($tag);
      while (<FILE>) {
        ( $_ =~ m/$tag/ ) && last;
      }
    }

    # skip the documentation

    # we should not need to have item in this if statement (it
    # properly belongs in the over/back section) but people do not
    # read the perldoc.

    if (/^=(head[1-4]|pod|for|item)/) {
      /^=cut/ && next while <FILE>;
    }

    if (/^=over/) {
      /^=back/ && next while <FILE>;
    }

    # skip the data section
    if (m/^__(DATA|END)__$/) {
      last;
    }

    # Each keyword can appear multiple times.  Don't
    #  bother with datastructures to store these strings,
    #  if we need to print it print it now.
    #
        # Again allow for "our".
    if (m/^\s*(our\s+)?\$RPM_Requires\s*=\s*["'](.*)['"]/i) {
      foreach $_ (split(/\s+/, $2)) {
        print "$_\n";
      }
    }

    my $modver_re = qr/[.0-9]+/;

    #
    # The (require|use) match further down in this subroutine will match lines
    # within a multi-line print or return statements.  So, let's skip over such
    # statements whose content should not be loading modules anyway. -BEF-
    #
    if (m/print(?:\s+|\s+\S+\s+)\<\<\s*(["'`])(.+?)\1/ ||
        m/print(\s+|\s+\S+\s+)\<\<(\w+)/ ||
	m/return(\s+)\<\<(\w+)/ ) {

        my $tag = $2;
        while (<FILE>) {
            chomp;
            ( $_ eq $tag ) && last;
        }
        $_ = <FILE>;
    }

    # Skip multiline print and assign statements
    if ( m/\$\S+\s*=\s*(")([^"\\]|(\\.))*$/ ||
         m/\$\S+\s*=\s*(')([^'\\]|(\\.))*$/ ||
         m/print\s+(")([^"\\]|(\\.))*$/ ||
         m/print\s+(')([^'\\]|(\\.))*$/ ) {

        my $quote = $1;
        while (<FILE>) {
          m/^([^\\$quote]|(\\.))*$quote/ && last;
        }
        $_ = <FILE>;
    }

    # Skip multiline print and assign statements
    if ( m/\$\S+\s*=\s*(")([^"\\]|(\\.))*$/ ||
         m/\$\S+\s*=\s*(')([^'\\]|(\\.))*$/ ||
         m/print\s+(")([^"\\]|(\\.))*$/ ||
         m/print\s+(')([^'\\]|(\\.))*$/ ) {

        my $quote = $1;
        while (<FILE>) {
          m/^([^\\$quote]|(\\.))*$quote/ && last;
        }
        $_ = <FILE>;
    }

    if (

# ouch could be in a eval, perhaps we do not want these since we catch
# an exception they must not be required

#   eval { require Term::ReadLine } or die $@;
#   eval "require Term::Rendezvous;" or die $@;
#   eval { require Carp } if defined $^S; # If error/warning during compilation,


        (m/^(\s*)         # we hope the inclusion starts the line
         (require|use)\s+(?!\{)     # do not want 'do {' loops
         # quotes around name are always legal
         ['"]?([^; '"\t#]+)['"]?[\t; ]
         # the syntax for 'use' allows version requirements
         # the latter part is for "use base qw(Foo)" and friends special case
         \s*($modver_re|(qw\s*[(\/'"]\s*|['"])[^)\/"'\$]*?\s*[)\/"'])?
         /x)
       ) {
      my ($whitespace, $statement, $module, $version) = ($1, $2, $3, $4);

      # we only consider require statements that are flushed against
      # the left edge. any other require statements give too many
      # false positives, as they are usually inside of an if statement
      # as a fallback module or a rarely used option

      ($whitespace ne "" && $statement eq "require") && next;

      # if there is some interpolation of variables just skip this
      # dependency, we do not want
      #        do "$ENV{LOGDIR}/$rcfile";

      ($module =~ m/\$/) && next;

      # skip if the phrase was "use of" -- shows up in gimp-perl, et al.
      next if $module eq 'of';

      # if the module ends in a comma we probably caught some
      # documentation of the form 'check stuff,\n do stuff, clean
      # stuff.' there are several of these in the perl distribution

      ($module  =~ m/[,>]$/) && next;

      # if the module name starts in a dot it is not a module name.
      # Is this necessary?  Please give me an example if you turn this
      # back on.

      #      ($module =~ m/^\./) && next;

      # if the module starts with /, it is an absolute path to a file
      if ($module =~ m(^/)) {
        next;
      }

      # sometimes people do use POSIX qw(foo), or use POSIX(qw(foo)) etc.
      # we can strip qw.*$, as well as (.*$:
      $module =~ s/qw.*$//;
      $module =~ s/\(.*$//;

      # if the module ends with .pm, strip it to leave only basename.
      $module =~ s/\.pm$//;

      # some perl programmers write 'require URI/URL;' when
      # they mean 'require URI::URL;'

      $module =~ s/\//::/;

      # trim off trailing parentheses if any.  Sometimes people pass
      # the module an empty list.

      $module =~ s/\(\s*\)$//;

      if ( $module =~ m/^v?([0-9._]+)$/ ) {
      # if module is a number then both require and use interpret that
      # to mean that a particular version of perl is specified

      my $ver = $1;
      if ($ver =~ /5.00/) {
        $perlreq{"0:$ver"} = 1;
        next;
      }
      else {
        $perlreq{"1:$ver"} = 1;
        next;
      }

      };

      # ph files do not use the package name inside the file.
      # perlmodlib documentation says:

      #       the .ph files made by h2ph will probably end up as
      #       extension modules made by h2xs.

      # so do not expend much effort on these.


      # there is no easy way to find out if a file named systeminfo.ph
      # will be included with the name sys/systeminfo.ph so only use the
      # basename of *.ph files

      ($module =~ m/\.ph$/) && next;

      # use base|parent qw(Foo) dependencies
      if ($statement eq "use" && ($module eq "base" || $module eq "parent")) {
        add_require($module, undef);
        if ($version =~ /^qw\s*[(\/'"]\s*([^)\/"']+?)\s*[)\/"']/) {
          add_require($_, undef) for split(' ', $1);
        }
        elsif ($version =~ /(["'])([^"']+)\1/) {
          # requires like "use base name" can be removed if they are 
          # provided in the same file
          if (($whitespace eq "") && ($statement eq "use") && ($module eq "base"))  {
            add_require_removable($2, undef);
          } else {
            add_require($2, undef);
          }
        }
        next;
      }
      $version = undef unless $version =~ /^$modver_re$/o;

      add_require($module, $version);
    }

  }

  close(FILE) ||
    die("$0: Could not close file: '$file' : $!\n");

  return;
}

sub process_file_provides {

  my ($file) = @_;
  chomp $file;

  return if (! $HAVE_PROV);

  my @result = readpipe( "$prov_script $file" );
  foreach my $prov (@result) {
    $provide{$1} = undef if $prov =~ /perl\(([_:a-zA-Z0-9]+)\)/;
  }

}