#!/usr/bin/perl

# RPM (and it's 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 alternative 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 script to print the proper name for perl libraries.

# To save development time I do not parse the perl grammmar 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 proper name 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 lines in the file which match the pattern
#      (m/^\s*\$VERSION\s*=\s+/)
# then these are taken to be the version numbers of the modules.
# Special care is taken with a few known idioms for specifying version
# numbers of files under rcs/cvs control.

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

if ("@ARGV") {
  foreach (@ARGV) {
    next if !/\.pm$/;
    process_file($_);
  }
} else {

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

  foreach (<>) {
    chomp $_;
    next if !/\.pm$/;
    process_file($_) if -f $_;
  }
}


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

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

    my $v = qx{ rpm --eval '%perl_convert_version $require{$module}' };
    print "perl($module) = $v\n";
  }
}

exit 0;



sub process_file {

  my ($file) = @_;
  
  open(FILE, "<$file") || return;

  my ($package, $version, $incomment, $inover) = ();

  while (<FILE>) {
    
    # 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 (m/^=(head1|head2|pod|item)/) {
      $incomment = 1;
    }

    if (m/^=(cut)/) {
      $incomment = 0;
      $inover = 0;
    }
    
    if (m/^=(over)/) {
      $inover = 1;
    }

    if (m/^=(back)/) {
      $inover = 0;
    }

    if ($incomment || $inover || m/^\s*#/) {
       next;
    }
    
    # skip the data section
    if (m/^__(DATA|END)__$/) {
      last;
    }

    # not everyone puts the package name of the file as the first
    # package name so we report all namespaces as if they were
    # provided packages (really ugly).

    if (m/^\s*package\s+([_:a-zA-Z0-9]+)\s*;/) {
	# some internal packages, like DB, might be temporarily redefined inside a module.
	if (!($package && $1 eq 'DB')) {
	    $package=$1;
	    undef $version;
	    $require{$package}=undef;
	}
    }

    # after we found the package name take the first assignment to
    # $VERSION as the version number. Exporter requires that the
    # variable be called VERSION so we are safe.

    # here are examples of VERSION lines from the perl distribution

    #FindBin.pm:$VERSION = $VERSION = sprintf("%d.%02d", q$Revision: 270245 $ =~ /(\d+)\.(\d+)/);
    #ExtUtils/Install.pm:$VERSION = substr q$Revision: 270245 $, 10;
    #CGI/Apache.pm:$VERSION = (qw$Revision: 270245 $)[1];
    #DynaLoader.pm:$VERSION = $VERSION = "1.03";     # avoid typo warning
    #$Locale::Maketext::Simple::VERSION = '0.21';

    if ( 
	($package) && 
    (m/^(.*;)?\s*((my|our)\s+)?\$(${package}::)?VERSION\s*=\s+/)
       ) {

      # first see if the version string contains the string
      # '$Revision' this often causes bizzare strings and is the most
      # common method of non static numbering.

      if (m/(\$Revision: (\d+[.0-9]+))/) {
	$version= $2; 
      } elsif (m/VERSION.*?[\'\"]?(\d+[._0-9]+)[\'\"]?/) {
	
	# look for a static number hard coded in the script
	
	$version= $1; 
      }
      $require{$package}=$version;
    }
    
    # Each keyword can appear multiple times.  Don't
    #  bother with datastructures to store these strings,
    #  if we need to print it print it now.
	
    if ( m/^\s*\$RPM_Provides\s*=\s*["'](.*)['"]/i) {
      foreach $_ (split(/\s+/, $1)) {
	print "$_\n";
      }
    }

  }

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

  return ;
}