path: root/utils/h2xs.PL

#!/usr/local/bin/perl

use Config;
use File::Basename qw(&basename &dirname);
use Cwd;

# List explicitly here the variables you want Configure to
# generate.  Metaconfig only looks for shell variables, so you
# have to mention them as if they were shell variables, not
# %Config entries.  Thus you write
#  $startperl
# to ensure Configure will look for $Config{startperl}.

# This forces PL files to create target in same directory as PL file.
# This is so that make depend always knows where to find PL derivatives.
$origdir = cwd;
chdir dirname($0);
$file = basename($0, '.PL');
$file .= '.com' if $^O eq 'VMS';

open OUT,">$file" or die "Can't create $file: $!";

print "Extracting $file (with variable substitutions)\n";

# In this section, perl variables will be expanded during extraction.
# You can use $Config{...} to use Configure variables.

print OUT <<"!GROK!THIS!";
$Config{startperl}
    eval 'exec $Config{perlpath} -S \$0 \${1+"\$@"}'
	if \$running_under_some_shell;
!GROK!THIS!

# In the following, perl variables are not expanded during extraction.

print OUT <<'!NO!SUBS!';

=head1 NAME

h2xs - convert .h C header files to Perl extensions

=head1 SYNOPSIS

B<h2xs> [B<-ACOPXcdf>] [B<-v> version] [B<-n> module_name] [B<-p> prefix] [B<-s> sub] [headerfile ... [extra_libraries]]

B<h2xs> B<-h>

=head1 DESCRIPTION

I<h2xs> builds a Perl extension from C header files.  The extension
will include functions which can be used to retrieve the value of any
#define statement which was in the C header files.

The I<module_name> will be used for the name of the extension.  If
module_name is not supplied then the name of the first header file
will be used, with the first character capitalized.

If the extension might need extra libraries, they should be included
here.  The extension Makefile.PL will take care of checking whether
the libraries actually exist and how they should be loaded.
The extra libraries should be specified in the form -lm -lposix, etc,
just as on the cc command line.  By default, the Makefile.PL will
search through the library path determined by Configure.  That path
can be augmented by including arguments of the form B<-L/another/library/path>
in the extra-libraries argument.

=head1 OPTIONS

=over 5

=item B<-A>

Omit all autoload facilities.  This is the same as B<-c> but also removes the
S<C<use AutoLoader>> statement from the .pm file.

=item B<-C>

Omits creation of the F<Changes> file, and adds a HISTORY section to
the POD template.

=item B<-F>

Additional flags to specify to C preprocessor when scanning header for
function declarations.  Should not be used without B<-x>.

=item B<-M> I<regular expression>

selects functions/macros to process.

=item B<-O>

Allows a pre-existing extension directory to be overwritten.

=item B<-P>

Omit the autogenerated stub POD section. 

=item B<-X>

Omit the XS portion.  Used to generate templates for a module which is not
XS-based.  C<-c> and C<-f> are implicitly enabled.

=item B<-c>

Omit C<constant()> from the .xs file and corresponding specialised
C<AUTOLOAD> from the .pm file.

=item B<-d>

Turn on debugging messages.

=item B<-f>

Allows an extension to be created for a header even if that header is
not found in standard include directories.

=item B<-h>

Print the usage, help and version for this h2xs and exit.

=item B<-n> I<module_name>

Specifies a name to be used for the extension, e.g., S<-n RPC::DCE>

=item B<-o> I<regular expression>

Use "opaque" data type for the C types matched by the regular
expression, even if these types are C<typedef>-equivalent to types
from typemaps.  Should not be used without B<-x>.

This may be useful since, say, types which are C<typedef>-equivalent
to integers may represent OS-related handles, and one may want to work
with these handles in OO-way, as in C<$handle-E<gt>do_something()>.
Use C<-o .> if you want to handle all the C<typedef>ed types as opaque types.

The type-to-match is whitewashed (except for commas, which have no
whitespace before them, and multiple C<*> which have no whitespace
between them).

=item B<-p> I<prefix>

Specify a prefix which should be removed from the Perl function names, e.g., S<-p sec_rgy_> 
This sets up the XS B<PREFIX> keyword and removes the prefix from functions that are
autoloaded via the C<constant()> mechanism.

=item B<-s> I<sub1,sub2>

Create a perl subroutine for the specified macros rather than autoload with the constant() subroutine.
These macros are assumed to have a return type of B<char *>, e.g., S<-s sec_rgy_wildcard_name,sec_rgy_wildcard_sid>.

=item B<-v> I<version>

Specify a version number for this extension.  This version number is added
to the templates.  The default is 0.01.

=item B<-x>

Automatically generate XSUBs basing on function declarations in the
header file.  The package C<C::Scan> should be installed. If this
option is specified, the name of the header file may look like
C<NAME1,NAME2>. In this case NAME1 is used instead of the specified string,
but XSUBs are emitted only for the declarations included from file NAME2.

Note that some types of arguments/return-values for functions may
result in XSUB-declarations/typemap-entries which need
hand-editing. Such may be objects which cannot be converted from/to a
pointer (like C<long long>), pointers to functions, or arrays.  See
also the section on L<LIMITATIONS of B<-x>>.

=back

=head1 EXAMPLES


	# Default behavior, extension is Rusers
	h2xs rpcsvc/rusers

	# Same, but extension is RUSERS
	h2xs -n RUSERS rpcsvc/rusers

	# Extension is rpcsvc::rusers. Still finds <rpcsvc/rusers.h>
	h2xs rpcsvc::rusers

	# Extension is ONC::RPC.  Still finds <rpcsvc/rusers.h>
	h2xs -n ONC::RPC rpcsvc/rusers

	# Without constant() or AUTOLOAD
	h2xs -c rpcsvc/rusers

	# Creates templates for an extension named RPC
	h2xs -cfn RPC

	# Extension is ONC::RPC.
	h2xs -cfn ONC::RPC

	# Makefile.PL will look for library -lrpc in 
	# additional directory /opt/net/lib
	h2xs rpcsvc/rusers -L/opt/net/lib -lrpc

        # Extension is DCE::rgynbase
        # prefix "sec_rgy_" is dropped from perl function names
        h2xs -n DCE::rgynbase -p sec_rgy_ dce/rgynbase

        # Extension is DCE::rgynbase
        # prefix "sec_rgy_" is dropped from perl function names
        # subroutines are created for sec_rgy_wildcard_name and sec_rgy_wildcard_sid
        h2xs -n DCE::rgynbase -p sec_rgy_ \
        -s sec_rgy_wildcard_name,sec_rgy_wildcard_sid dce/rgynbase

	# Make XS without defines in perl.h, but with function declarations
	# visible from perl.h. Name of the extension is perl1.
	# When scanning perl.h, define -DEXT=extern -DdEXT= -DINIT(x)=
	# Extra backslashes below because the string is passed to shell.
	# Note that a directory with perl header files would 
	#  be added automatically to include path.
	h2xs -xAn perl1 -F "-DEXT=extern -DdEXT= -DINIT\(x\)=" perl.h

	# Same with function declaration in proto.h as visible from perl.h.
	h2xs -xAn perl2 perl.h,proto.h

	# Same but select only functions which match /^av_/
	h2xs -M '^av_' -xAn perl2 perl.h,proto.h

	# Same but treat SV* etc as "opaque" types
	h2xs -o '^[S]V \*$' -M '^av_' -xAn perl2 perl.h,proto.h

=head1 ENVIRONMENT

No environment variables are used.

=head1 AUTHOR

Larry Wall and others

=head1 SEE ALSO

L<perl>, L<perlxstut>, L<ExtUtils::MakeMaker>, and L<AutoLoader>.

=head1 DIAGNOSTICS

The usual warnings if it cannot read or write the files involved.

=head1 LIMITATIONS of B<-x>

F<h2xs> would not distinguish whether an argument to a C function
which is of the form, say, C<int *>, is an input, output, or
input/output parameter.  In particular, argument declarations of the
form

    int
    foo(n)
	int *n

should be better rewritten as

    int
    foo(n)
	int &n

if C<n> is an input parameter.

Additionally, F<h2xs> has no facilities to intuit that a function

   int
   foo(addr,l)
	char *addr
	int   l

takes a pair of address and length of data at this address, so it is better
to rewrite this function as

    int
    foo(sv)
	SV *addr
    PREINIT:
	STRLEN len;
	char *s;
    CODE:
	s = SvPV(sv,len);
	RETVAL = foo(s, len);
    OUTPUT:
	RETVAL

or alternately

    static int
    my_foo(SV *sv)
    {
	STRLEN len;
	char *s = SvPV(sv,len);

	return foo(s, len);
    }

    MODULE = foo	PACKAGE = foo	PREFIX = my_

    int
    foo(sv)
	SV *sv

See L<perlxs> and L<perlxstut> for additional details.

=cut

use strict;


my( $H2XS_VERSION ) = ' $Revision: 1.20 $ ' =~ /\$Revision:\s+([^\s]+)/;
my $TEMPLATE_VERSION = '0.01';
my @ARGS = @ARGV;

use Getopt::Std;

sub usage{
	warn "@_\n" if @_;
    die "h2xs [-ACOPXcdfh] [-v version] [-n module_name] [-p prefix] [-s subs] [headerfile [extra_libraries]]
version: $H2XS_VERSION
    -A   Omit all autoloading facilities (implies -c).
    -C   Omit creating the Changes file, add HISTORY heading to stub POD.
    -F   Additional flags for C preprocessor (used with -x).
    -M   Mask to select C functions/macros (default is select all).
    -O   Allow overwriting of a pre-existing extension directory.
    -P   Omit the stub POD section.
    -X   Omit the XS portion (implies both -c and -f).
    -c   Omit the constant() function and specialised AUTOLOAD from the XS file.
    -d   Turn on debugging messages.
    -f   Force creation of the extension even if the C header does not exist.
    -h   Display this help message
    -n   Specify a name to use for the extension (recommended).
    -o   Regular expression for \"opaque\" types.
    -p   Specify a prefix which should be removed from the Perl function names.
    -s   Create subroutines for specified macros.
    -v   Specify a version number for this extension.
    -x   Autogenerate XSUBs using C::Scan.
extra_libraries
         are any libraries that might be needed for loading the
         extension, e.g. -lm would try to link in the math library.
";
}


getopts("ACF:M:OPXcdfhn:o:p:s:v:x") || usage;
use vars qw($opt_A $opt_C $opt_F $opt_M $opt_O $opt_P $opt_X $opt_c
	    $opt_d $opt_f $opt_h $opt_n $opt_o $opt_p $opt_s $opt_v $opt_x);

usage if $opt_h;

if( $opt_v ){
	$TEMPLATE_VERSION = $opt_v;
}

# -A implies -c.
$opt_c = 1 if $opt_A;

# -X implies -c and -f
$opt_c = $opt_f = 1 if $opt_X;

my %const_xsub = map { $_,1 } split(/,+/, $opt_s) if $opt_s;
my $extralibs;
my @path_h;

while (my $arg = shift) {
    if ($arg =~ /^-l/i) {
        $extralibs = "$arg @ARGV";
        last;
    }
    push(@path_h, $arg);
}

usage "Must supply header file or module name\n"
        unless (@path_h or $opt_n);

my $fmask;
my $tmask;

$fmask = qr{$opt_M} if defined $opt_M;
$tmask = qr{$opt_o} if defined $opt_o;
my $tmask_all = $tmask && $opt_o eq '.';

if ($opt_x) {
  eval {require C::Scan; 1}
    or die <<EOD;
C::Scan required if you use -x option.
To install C::Scan, execute
   perl -MCPAN -e "install C::Scan"
EOD
  unless ($tmask_all) {
    $C::Scan::VERSION >= 0.70
      or die <<EOD;
C::Scan v. 0.70 or later required unless you use -o . option.
You have version $C::Scan::VERSION installed as $INC{'C/Scan.pm'}.
To install C::Scan, execute
   perl -MCPAN -e "install C::Scan"
EOD
  }
} elsif ($opt_o or $opt_F) {
  warn <<EOD;
Options -o and -F do not make sense without -x.
EOD
}

my @path_h_ini = @path_h;
my ($name, %fullpath, %prefix, %seen_define, %prefixless, %const_names);

if( @path_h ){
    use Config;
    use File::Spec;
    my @paths;
    if ($^O eq 'VMS') {  # Consider overrides of default location
      # XXXX This is not equivalent to what the older version did:
      #		it was looking at $hadsys header-file per header-file...
      my($hadsys) = grep s!^sys/!!i , @path_h;
      @paths = qw( Sys\$Library VAXC$Include );
      push @paths, ($hadsys ? 'GNU_CC_Include[vms]' : 'GNU_CC_Include[000000]');
      push @paths, qw( DECC$Library_Include DECC$System_Include );
    } else {
      @paths = (File::Spec->curdir(), $Config{usrinc},
		(split ' ', $Config{locincpth}), '/usr/include');
    }
    foreach my $path_h (@path_h) {
        $name ||= $path_h;
    if( $path_h =~ s#::#/#g && $opt_n ){
	warn "Nesting of headerfile ignored with -n\n";
    }
    $path_h .= ".h" unless $path_h =~ /\.h$/;
    my $fullpath = $path_h;
    $path_h =~ s/,.*$// if $opt_x;
    $fullpath{$path_h} = $fullpath;

    if (not -f $path_h) {
      my $tmp_path_h = $path_h;
      for my $dir (@paths) {
	last if -f ($path_h = File::Spec->catfile($dir, $tmp_path_h));
      }
    }

    if (!$opt_c) {
      die "Can't find $path_h\n" if ( ! $opt_f && ! -f $path_h );
      # Scan the header file (we should deal with nested header files)
      # Record the names of simple #define constants into const_names
            # Function prototypes are processed below.
      open(CH, "<$path_h") || die "Can't open $path_h: $!\n";
    defines:
      while (<CH>) {
	if (/^[ \t]*#[ \t]*define\s+([\$\w]+)\b(?!\()\s*(?=[^" \t])(.*)/) {
	    my $def = $1;
	    my $rest = $2;
	    $rest =~ s!/\*.*?(\*/|\n)|//.*!!g; # Remove comments
	    $rest =~ s/^\s+//;
	    $rest =~ s/\s+$//;
	    # Cannot do: (-1) and ((LHANDLE)3) are OK:
	    #print("Skip non-wordy $def => $rest\n"),
	    #  next defines if $rest =~ /[^\w\$]/;
	    if ($rest =~ /"/) {
	      print("Skip stringy $def => $rest\n") if $opt_d;
	      next defines;
	    }
	    print "Matched $_ ($def)\n" if $opt_d;
	    $seen_define{$def} = $rest;
	    $_ = $def;
	    next if /^_.*_h_*$/i; # special case, but for what?
	    if (defined $opt_p) {
	      if (!/^$opt_p(\d)/) {
		++$prefix{$_} if s/^$opt_p//;
	      }
	      else {
		warn "can't remove $opt_p prefix from '$_'!\n";
	      }
	    }
	    $prefixless{$def} = $_;
	    if (!$fmask or /$fmask/) {
		print "... Passes mask of -M.\n" if $opt_d and $fmask;
		$const_names{$_}++;
	    }
	  }
      }
      close(CH);
    }
    }
}


my $module = $opt_n || do {
	$name =~ s/\.h$//;
	if( $name !~ /::/ ){
		$name =~ s#^.*/##;
		$name = "\u$name";
	}
	$name;
};

my ($ext, $nested, @modparts, $modfname, $modpname);
(chdir 'ext', $ext = 'ext/') if -d 'ext';

if( $module =~ /::/ ){
	$nested = 1;
	@modparts = split(/::/,$module);
	$modfname = $modparts[-1];
	$modpname = join('/',@modparts);
}
else {
	$nested = 0;
	@modparts = ();
	$modfname = $modpname = $module;
}


if ($opt_O) {
	warn "Overwriting existing $ext$modpname!!!\n" if -e $modpname;
} else {
	die "Won't overwrite existing $ext$modpname\n" if -e $modpname;
}
if( $nested ){
	my $modpath = "";
	foreach (@modparts){
		mkdir("$modpath$_", 0777);
		$modpath .= "$_/";
	}
}
mkdir($modpname, 0777);
chdir($modpname) || die "Can't chdir $ext$modpname: $!\n";

my %types_seen;
my %std_types;
my $fdecls = [];
my $fdecls_parsed = [];
my $typedef_rex;
my %typedefs_pre;
my %known_fnames;

my @fnames;
my @fnames_no_prefix;

if( ! $opt_X ){  # use XS, unless it was disabled
  open(XS, ">$modfname.xs") || die "Can't create $ext$modpname/$modfname.xs: $!\n";
  if ($opt_x) {
    require Config;		# Run-time directive
    warn "Scanning typemaps...\n";
    get_typemap();
    my @td;
    my @good_td;
    my $addflags = $opt_F || '';

    foreach my $filename (@path_h) {
      my $c;
      my $filter;

      if ($fullpath{$filename} =~ /,/) {
	$filename = $`;
	$filter = $';
      }
      warn "Scanning $filename for functions...\n";
      $c = new C::Scan 'filename' => $filename, 'filename_filter' => $filter,
	'add_cppflags' => $addflags;
      $c->set('includeDirs' => ["$Config::Config{archlib}/CORE"]);

      push @$fdecls_parsed, @{ $c->get('parsed_fdecls') };
      push(@$fdecls, @{$c->get('fdecls')});

      push @td, @{$c->get('typedefs_maybe')};

      unless ($tmask_all) {
	warn "Scanning $filename for typedefs...\n";
	my $td = $c->get('typedef_hash');
	# eval {require 'dumpvar.pl'; ::dumpValue($td)} or warn $@ if $opt_d;
	my @f_good_td = grep $td->{$_}[1] eq '', keys %$td;
	push @good_td, @f_good_td;
	@typedefs_pre{@f_good_td}  = map $_->[0], @$td{@f_good_td};
      }
    }
    { local $" = '|';
      $typedef_rex = qr(\b(?<!struct )(?:@good_td)\b);
    }
    %known_fnames = map @$_[1,3], @$fdecls_parsed; # [1,3] is NAME, FULLTEXT
    if ($fmask) {
      my @good;
      for my $i (0..$#$fdecls_parsed) {
	next unless $fdecls_parsed->[$i][1] =~ /$fmask/; # [1] is NAME
	push @good, $i;
	print "... Function $fdecls_parsed->[$i][1] passes -M mask.\n"
	  if $opt_d;
      }
      $fdecls = [@$fdecls[@good]];
      $fdecls_parsed = [@$fdecls_parsed[@good]];
    }
    @fnames = sort map $_->[1], @$fdecls_parsed; # 1 is NAME
    # Sort declarations:
    {
      my %h = map( ($_->[1], $_), @$fdecls_parsed);
      $fdecls_parsed = [ @h{@fnames} ];
    }
    @fnames_no_prefix = @fnames;
    @fnames_no_prefix
      = sort map { ++$prefix{$_} if s/^$opt_p(?!\d)//; $_ } @fnames_no_prefix;
    # Remove macros which expand to typedefs
    print "Typedefs are @td.\n" if $opt_d;
    my %td = map {($_, $_)} @td;
    # Add some other possible but meaningless values for macros
    for my $k (qw(char double float int long short unsigned signed void)) {
      $td{"$_$k"} = "$_$k" for ('', 'signed ', 'unsigned ');
    }
    # eval {require 'dumpvar.pl'; ::dumpValue( [\@td, \%td] ); 1} or warn $@;
    my $n = 0;
    my %bad_macs;
    while (keys %td > $n) {
      $n = keys %td;
      my ($k, $v);
      while (($k, $v) = each %seen_define) {
	# print("found '$k'=>'$v'\n"), 
	$bad_macs{$k} = $td{$k} = $td{$v} if exists $td{$v};
      }
    }
    # Now %bad_macs contains names of bad macros
    for my $k (keys %bad_macs) {
      delete $const_names{$prefixless{$k}};
      print "Ignoring macro $k which expands to a typedef name '$bad_macs{$k}'\n" if $opt_d;
    }
  }
}
my @const_names = sort keys %const_names;

open(PM, ">$modfname.pm") || die "Can't create $ext$modpname/$modfname.pm: $!\n";

$" = "\n\t";
warn "Writing $ext$modpname/$modfname.pm\n";

print PM <<"END";
package $module;

use strict;
END

if( $opt_X || $opt_c || $opt_A ){
	# we won't have our own AUTOLOAD(), so won't have $AUTOLOAD
	print PM <<'END';
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
END
}
else{
	# we'll have an AUTOLOAD(), and it will have $AUTOLOAD and
	# will want Carp.
	print PM <<'END';
use Carp;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $AUTOLOAD);
END
}

print PM <<'END';

require Exporter;
END

print PM <<"END" if ! $opt_X;  # use DynaLoader, unless XS was disabled
require DynaLoader;
END


# Are we using AutoLoader or not?
unless ($opt_A) { # no autoloader whatsoever.
	unless ($opt_c) { # we're doing the AUTOLOAD
		print PM "use AutoLoader;\n";
	}
	else {
		print PM "use AutoLoader qw(AUTOLOAD);\n"
	}
}

# Determine @ISA.
my $myISA = '@ISA = qw(Exporter';	# We seem to always want this.
$myISA .= ' DynaLoader' 	unless $opt_X;  # no XS
$myISA .= ');';
print PM "\n$myISA\n\n";

my @exported_names = (@const_names, @fnames_no_prefix);

print PM<<"END";
# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.

# This allows declaration	use $module ':all';
# If you do not need this, moving things directly into \@EXPORT or \@EXPORT_OK
# will save memory.
%EXPORT_TAGS = ( 'all' => [ qw(
	@exported_names
) ] );

\@EXPORT_OK = ( \@{ \$EXPORT_TAGS{'all'} } );

\@EXPORT = (

);
\$VERSION = '$TEMPLATE_VERSION';

END

print PM <<"END" unless $opt_c or $opt_X;
sub AUTOLOAD {
    # This AUTOLOAD is used to 'autoload' constants from the constant()
    # XS function.  If a constant is not found then control is passed
    # to the AUTOLOAD in AutoLoader.

    my \$constname;
    (\$constname = \$AUTOLOAD) =~ s/.*:://;
    croak "&$module::constant not defined" if \$constname eq 'constant';
    my \$val = constant(\$constname, \@_ ? \$_[0] : 0);
    if (\$! != 0) {
	if (\$! =~ /Invalid/ || \$!{EINVAL}) {
	    \$AutoLoader::AUTOLOAD = \$AUTOLOAD;
	    goto &AutoLoader::AUTOLOAD;
	}
	else {
		croak "Your vendor has not defined $module macro \$constname";
	}
    }
    {  no strict 'refs';
       # Next line doesn't help with older Perls; in newers: no such warnings
       # local \$^W = 0;		# Prototype mismatch: sub XXX vs ()
       if (\$] >= 5.00561) {	# Fixed between 5.005_53 and 5.005_61
	 *\$AUTOLOAD = sub () { \$val };
       } else {
	 *\$AUTOLOAD = sub { \$val };
       }
    }
    goto &\$AUTOLOAD;
}

END

if( ! $opt_X ){ # print bootstrap, unless XS is disabled
	print PM <<"END";
bootstrap $module \$VERSION;
END
}

my $after;
if( $opt_P ){ # if POD is disabled
	$after = '__END__';
}
else {
	$after = '=cut';
}

print PM <<"END";

# Preloaded methods go here.
END

print PM <<"END" unless $opt_A;

# Autoload methods go after $after, and are processed by the autosplit program.
END

print PM <<"END";

1;
__END__
END

my $author = "A. U. Thor";
my $email = 'a.u.thor@a.galaxy.far.far.away';

my $revhist = '';
$revhist = <<EOT if $opt_C;

=head1 HISTORY

=over 8

=item $TEMPLATE_VERSION

Original version; created by h2xs $H2XS_VERSION with options

  @ARGS

=back

EOT

my $exp_doc = <<EOD;

=head2 EXPORT

None by default.

EOD
if (@const_names and not $opt_P) {
  $exp_doc .= <<EOD;
=head2 Exportable constants

  @{[join "\n  ", @const_names]}

EOD
}
if (defined $fdecls and @$fdecls and not $opt_P) {
  $exp_doc .= <<EOD;
=head2 Exportable functions

EOD
  $exp_doc .= <<EOD if $opt_p;
When accessing these functions from Perl, prefix C<$opt_p> should be removed.

EOD
  $exp_doc .= <<EOD;
  @{[join "\n  ", @known_fnames{@fnames}]}

EOD
}

my $pod = <<"END" unless $opt_P;
## Below is the stub of documentation for your module. You better edit it!
#
#=head1 NAME
#
#$module - Perl extension for blah blah blah
#
#=head1 SYNOPSIS
#
#  use $module;
#  blah blah blah
#
#=head1 DESCRIPTION
#
#Stub documentation for $module was created by h2xs. It looks like the
#author of the extension was negligent enough to leave the stub
#unedited.
#
#Blah blah blah.
#$exp_doc$revhist
#=head1 AUTHOR
#
#$author, $email
#
#=head1 SEE ALSO
#
#perl(1).
#
#=cut
END

$pod =~ s/^\#//gm unless $opt_P;
print PM $pod unless $opt_P;

close PM;


if( ! $opt_X ){ # print XS, unless it is disabled
warn "Writing $ext$modpname/$modfname.xs\n";

print XS <<"END";
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

END
if( @path_h ){
    foreach my $path_h (@path_h_ini) {
	my($h) = $path_h;
	$h =~ s#^/usr/include/##;
	if ($^O eq 'VMS') { $h =~ s#.*vms\]#sys/# or $h =~ s#.*[:>\]]##; }
        print XS qq{#include <$h>\n};
    }
    print XS "\n";
}

my %pointer_typedefs;
my %struct_typedefs;

sub td_is_pointer {
  my $type = shift;
  my $out = $pointer_typedefs{$type};
  return $out if defined $out;
  my $otype = $type;
  $out = ($type =~ /\*$/);
  # This converts only the guys which do not have trailing part in the typedef
  if (not $out
      and $typedef_rex and $type =~ s/($typedef_rex)/$typedefs_pre{$1}/go) {
    $type = normalize_type($type);
    print "Is-Pointer: Type mutation via typedefs: $otype ==> $type\n"
      if $opt_d;
    $out = td_is_pointer($type);
  }
  return ($pointer_typedefs{$otype} = $out);
}

sub td_is_struct {
  my $type = shift;
  my $out = $struct_typedefs{$type};
  return $out if defined $out;
  my $otype = $type;
  $out = ($type =~ /^struct\b/) && !td_is_pointer($type);
  # This converts only the guys which do not have trailing part in the typedef
  if (not $out
      and $typedef_rex and $type =~ s/($typedef_rex)/$typedefs_pre{$1}/go) {
    $type = normalize_type($type);
    print "Is-Struct: Type mutation via typedefs: $otype ==> $type\n"
      if $opt_d;
    $out = td_is_struct($type);
  }
  return ($struct_typedefs{$otype} = $out);
}

# Some macros will bomb if you try to return them from a double-returning func.
# Say, ((char *)0), or strlen (if somebody #define STRLEN strlen).
# Fortunately, we can detect both these cases...
sub protect_convert_to_double {
  my $in = shift;
  my $val;
  return '' unless defined ($val = $seen_define{$in});
  return '(IV)' if $known_fnames{$val};
  # OUT_t of ((OUT_t)-1):
  return '' unless $val =~ /^\s*(\(\s*)?\(\s*([^()]*?)\s*\)/;
  td_is_pointer($2) ? '(IV)' : '';
}

# For each of the generated functions, length($pref) leading
# letters are already checked.  Moreover, it is recommended that
# the generated functions uses switch on letter at offset at least
# $off + length($pref).
#
# The given list has length($pref) chars removed at front, it is
# guarantied that $off leading chars in the rest are the same for all
# elts of the list.
#
# Returns: how at which offset it was decided to make a switch, or -1 if none.

sub write_const;

sub write_const {
  my ($fh, $pref, $off, $list) = (shift,shift,shift,shift);
  my %leading;
  my $offarg = length $pref;

  if (@$list == 0) {		# Can happen on the initial iteration only
    print $fh <<"END";
static double
constant(char *name, int len, int arg)
{
    errno = EINVAL;
    return 0;
}
END
    return -1;
  }

  if (@$list == 1) {		# Can happen on the initial iteration only
    my $protect = protect_convert_to_double("$pref$list->[0]");

    print $fh <<"END";
static double
constant(char *name, int len, int arg)
{
    if (strEQ(name + $offarg, "$list->[0]")) {	/* $pref removed */
#ifdef $pref$list->[0]
	return $protect$pref$list->[0];
#else
	errno = ENOENT;
	return 0;
#endif
    }
    errno = EINVAL;
    return 0;
}
END
    return -1;
  }

  for my $n (@$list) {
    my $c = substr $n, $off, 1;
    $leading{$c} = [] unless exists $leading{$c};
    push @{$leading{$c}}, substr $n, $off + 1;
  }

  if (keys(%leading) == 1) {
    return 1 + write_const $fh, $pref, $off + 1, $list;
  }

  my $leader = substr $list->[0], 0, $off;
  foreach my $letter (keys %leading) {
    write_const $fh, "$pref$leader$letter", 0, $leading{$letter}
      if @{$leading{$letter}} > 1;
  }

  my $npref = "_$pref";
  $npref = '' if $pref eq '';

  print $fh <<"END";
static double
constant$npref(char *name, int len, int arg)
{
    errno = 0;
END

  print $fh <<"END" if $off;
    if ($offarg + $off >= len ) {
	errno = EINVAL;
	return 0;
    }
END

  print $fh <<"END";
    switch (name[$offarg + $off]) {
END

  foreach my $letter (sort keys %leading) {
    my $let = $letter;
    $let = '\0' if $letter eq '';

    print $fh <<EOP;
    case '$let':
EOP
    if (@{$leading{$letter}} > 1) {
      # It makes sense to call a function
      if ($off) {
	print $fh <<EOP;
	if (!strnEQ(name + $offarg,"$leader", $off))
	    break;
EOP
      }
      print $fh <<EOP;
	return constant_$pref$leader$letter(name, len, arg);
EOP
    } else {
      # Do it ourselves
      my $protect
	= protect_convert_to_double("$pref$leader$letter$leading{$letter}[0]");

      print $fh <<EOP;
	if (strEQ(name + $offarg, "$leader$letter$leading{$letter}[0]")) {	/* $pref removed */
#ifdef $pref$leader$letter$leading{$letter}[0]
	    return $protect$pref$leader$letter$leading{$letter}[0];
#else
	    goto not_there;
#endif
	}
EOP
    }
  }
  print $fh <<"END";
    }
    errno = EINVAL;
    return 0;

not_there:
    errno = ENOENT;
    return 0;
}

END

}

if( ! $opt_c ) {
  print XS <<"END";
static int
not_here(char *s)
{
    croak("$module::%s not implemented on this architecture", s);
    return -1;
}

END

  write_const(\*XS, '', 0, \@const_names);
}

my $prefix;
$prefix = "PREFIX = $opt_p" if defined $opt_p;

# Now switch from C to XS by issuing the first MODULE declaration:
print XS <<"END";

MODULE = $module		PACKAGE = $module		$prefix

END

foreach (sort keys %const_xsub) {
    print XS <<"END";
char *
$_()

    CODE:
#ifdef $_
    RETVAL = $_;
#else
    croak("Your vendor has not defined the $module macro $_");
#endif

    OUTPUT:
    RETVAL

END
}

# If a constant() function was written then output a corresponding
# XS declaration:
print XS <<"END" unless $opt_c;

double
constant(sv,arg)
PREINIT:
	STRLEN		len;
INPUT:
	SV *		sv
	char *		s = SvPV(sv, len);
	int		arg
CODE:
	RETVAL = constant(s,len,arg);
OUTPUT:
	RETVAL

END

my %seen_decl;
my %typemap;

sub print_decl {
  my $fh = shift;
  my $decl = shift;
  my ($type, $name, $args) = @$decl;
  return if $seen_decl{$name}++; # Need to do the same for docs as well?

  my @argnames = map {$_->[1]} @$args;
  my @argtypes = map { normalize_type( $_->[0], 1 ) } @$args;
  my @argarrays = map { $_->[4] || '' } @$args;
  my $numargs = @$args;
  if ($numargs and $argtypes[-1] eq '...') {
    $numargs--;
    $argnames[-1] = '...';
  }
  local $" = ', ';
  $type = normalize_type($type, 1);

  print $fh <<"EOP";

$type
$name(@argnames)
EOP

  for my $arg (0 .. $numargs - 1) {
    print $fh <<"EOP";
	$argtypes[$arg]	$argnames[$arg]$argarrays[$arg]
EOP
  }
}

# Should be called before any actual call to normalize_type().
sub get_typemap {
  # We do not want to read ./typemap by obvios reasons.
  my @tm =  qw(../../../typemap ../../typemap ../typemap);
  my $stdtypemap =  "$Config::Config{privlib}/ExtUtils/typemap";
  unshift @tm, $stdtypemap;
  my $proto_re = "[" . quotemeta('\$%&*@;') . "]" ;

  # Start with useful default values
  $typemap{float} = 'T_DOUBLE';

  foreach my $typemap (@tm) {
    next unless -e $typemap ;
    # skip directories, binary files etc.
    warn " Scanning $typemap\n";
    warn("Warning: ignoring non-text typemap file '$typemap'\n"), next 
      unless -T $typemap ;
    open(TYPEMAP, $typemap) 
      or warn ("Warning: could not open typemap file '$typemap': $!\n"), next;
    my $mode = 'Typemap';
    while (<TYPEMAP>) {
      next if /^\s*\#/;
      if (/^INPUT\s*$/)   { $mode = 'Input'; next; }
      elsif (/^OUTPUT\s*$/)  { $mode = 'Output'; next; }
      elsif (/^TYPEMAP\s*$/) { $mode = 'Typemap'; next; }
      elsif ($mode eq 'Typemap') {
	next if /^\s*($|\#)/ ;
	my ($type, $image);
	if ( ($type, $image) =
	     /^\s*(.*?\S)\s+(\S+)\s*($proto_re*)\s*$/o
	     # This may reference undefined functions:
	     and not ($image eq 'T_PACKED' and $typemap eq $stdtypemap)) {
	  $typemap{normalize_type($type)} = $image;
	}
      }
    }
    close(TYPEMAP) or die "Cannot close $typemap: $!";
  }
  %std_types = %types_seen;
  %types_seen = ();
}


sub normalize_type {		# Second arg: do not strip const's before \*
  my $type = shift;
  my $do_keep_deep_const = shift;
  # If $do_keep_deep_const this is heuristical only
  my $keep_deep_const = ($do_keep_deep_const ? '\b(?![^(,)]*\*)' : '');
  my $ignore_mods 
    = "(?:\\b(?:(?:__const__|const)$keep_deep_const|static|inline|__inline__)\\b\\s*)*";
  if ($do_keep_deep_const) {	# Keep different compiled /RExen/o separately!
    $type =~ s/$ignore_mods//go;
  } else {
    $type =~ s/$ignore_mods//go;
  }
  $type =~ s/([^\s\w])/ \1 /g;
  $type =~ s/\s+$//;
  $type =~ s/^\s+//;
  $type =~ s/\s+/ /g;
  $type =~ s/\* (?=\*)/*/g;
  $type =~ s/\. \. \./.../g;
  $type =~ s/ ,/,/g;
  $types_seen{$type}++ 
    unless $type eq '...' or $type eq 'void' or $std_types{$type};
  $type;
}

my $need_opaque;

sub assign_typemap_entry {
  my $type = shift;
  my $otype = $type;
  my $entry;
  if ($tmask and $type =~ /$tmask/) {
    print "Type $type matches -o mask\n" if $opt_d;
    $entry = (td_is_struct($type) ? "T_OPAQUE_STRUCT" : "T_PTROBJ");
  }
  elsif ($typedef_rex and $type =~ s/($typedef_rex)/$typedefs_pre{$1}/go) {
    $type = normalize_type $type;
    print "Type mutation via typedefs: $otype ==> $type\n" if $opt_d;
    $entry = assign_typemap_entry($type);
  }
  $entry ||= $typemap{$otype}
    || (td_is_struct($type) ? "T_OPAQUE_STRUCT" : "T_PTROBJ");
  $typemap{$otype} = $entry;
  $need_opaque = 1 if $entry eq "T_OPAQUE_STRUCT";
  return $entry;
}

if ($opt_x) {
    for my $decl (@$fdecls_parsed) { print_decl(\*XS, $decl) }
}

close XS;

if (%types_seen) {
  my $type;
  warn "Writing $ext$modpname/typemap\n";
  open TM, ">typemap" or die "Cannot open typemap file for write: $!";

  for $type (sort keys %types_seen) {
    my $entry = assign_typemap_entry $type;
    print TM $type, "\t" x (5 - int((length $type)/8)), "\t$entry\n"
  }

  print TM <<'EOP' if $need_opaque; # Older Perls do not have correct entry
#############################################################################
INPUT
T_OPAQUE_STRUCT
	if (sv_derived_from($arg, \"${ntype}\")) {
	    STRLEN len;
	    char  *s = SvPV((SV*)SvRV($arg), len);

	    if (len != sizeof($var))
		croak(\"Size %d of packed data != expected %d\",
			len, sizeof($var));
	    $var = *($type *)s;
	}
	else
	    croak(\"$var is not of type ${ntype}\")
#############################################################################
OUTPUT
T_OPAQUE_STRUCT
	sv_setref_pvn($arg, \"${ntype}\", (char *)&$var, sizeof($var));
EOP

  close TM or die "Cannot close typemap file for write: $!";
}

} # if( ! $opt_X )

warn "Writing $ext$modpname/Makefile.PL\n";
open(PL, ">Makefile.PL") || die "Can't create $ext$modpname/Makefile.PL: $!\n";

print PL <<'END';
use ExtUtils::MakeMaker;
# See lib/ExtUtils/MakeMaker.pm for details of how to influence
# the contents of the Makefile that is written.
END
print PL "WriteMakefile(\n";
print PL "    'NAME'	=> '$module',\n";
print PL "    'VERSION_FROM' => '$modfname.pm', # finds \$VERSION\n"; 
if( ! $opt_X ){ # print C stuff, unless XS is disabled
  $opt_F = '' unless defined $opt_F;
  print PL "    'LIBS'	=> ['$extralibs'],   # e.g., '-lm' \n";
  print PL "    'DEFINE'	=> '$opt_F',     # e.g., '-DHAVE_SOMETHING' \n";
  print PL "    'INC'	=> '',     # e.g., '-I/usr/include/other' \n";
}
print PL ");\n";
close(PL) || die "Can't close $ext$modpname/Makefile.PL: $!\n";

warn "Writing $ext$modpname/test.pl\n";
open(EX, ">test.pl") || die "Can't create $ext$modpname/test.pl: $!\n";
print EX <<'_END_';
# Before `make install' is performed this script should be runnable with
# `make test'. After `make install' it should work as `perl test.pl'

######################### We start with some black magic to print on failure.

# Change 1..1 below to 1..last_test_to_print .
# (It may become useful if the test is moved to ./t subdirectory.)

BEGIN { $| = 1; print "1..1\n"; }
END {print "not ok 1\n" unless $loaded;}
_END_
print EX <<_END_;
use $module;
_END_
print EX <<'_END_';
$loaded = 1;
print "ok 1\n";

######################### End of black magic.

# Insert your test code below (better if it prints "ok 13"
# (correspondingly "not ok 13") depending on the success of chunk 13
# of the test code):

_END_
close(EX) || die "Can't close $ext$modpname/test.pl: $!\n";

unless ($opt_C) {
  warn "Writing $ext$modpname/Changes\n";
  $" = ' ';
  open(EX, ">Changes") || die "Can't create $ext$modpname/Changes: $!\n";
  @ARGS = map {/[\s\"\'\`\$*?^|&<>\[\]\{\}\(\)]/ ? "'$_'" : $_} @ARGS;
  print EX <<EOP;
Revision history for Perl extension $module.

$TEMPLATE_VERSION  @{[scalar localtime]}
\t- original version; created by h2xs $H2XS_VERSION with options
\t\t@ARGS

EOP
  close(EX) || die "Can't close $ext$modpname/Changes: $!\n";
}

warn "Writing $ext$modpname/MANIFEST\n";
open(MANI,'>MANIFEST') or die "Can't create MANIFEST: $!";
my @files = <*>;
if (!@files) {
  eval {opendir(D,'.');};
  unless ($@) { @files = readdir(D); closedir(D); }
}
if (!@files) { @files = map {chomp && $_} `ls`; }
if ($^O eq 'VMS') {
  foreach (@files) {
    # Clip trailing '.' for portability -- non-VMS OSs don't expect it
    s%\.$%%;
    # Fix up for case-sensitive file systems
    s/$modfname/$modfname/i && next;
    $_ = "\U$_" if $_ eq 'manifest' or $_ eq 'changes';
    $_ = 'Makefile.PL' if $_ eq 'makefile.pl';
  }
}
print MANI join("\n",@files), "\n";
close MANI;
!NO!SUBS!

close OUT or die "Can't close $file: $!";
chmod 0755, $file or die "Can't reset permissions for $file: $!\n";
exec("$Config{'eunicefix'} $file") if $Config{'eunicefix'} ne ':';
chdir $origdir;