#!/usr/local/bin/perl

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

# 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.
chdir(dirname($0));
($file = basename($0)) =~ s/\.PL$//;
$file =~ s/\.pl$//
	if ($Config{'osname'} eq 'VMS' or
	    $Config{'osname'} eq 'OS2');  # "case-forgiving"

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 perl -S \$0 "\$@"'
	if 0;
!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<-AOPXcf>] [B<-v> version] [B<-n> module_name] [headerfile [extra_libraries]]

B<h2xs> B<-h>

=head1 DESCRIPTION

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

The I<module_name> will be used for the name of the extension.  If
module_name is not supplied then the name of the 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<require AutoLoader>> statement from the .pm file.

=item B<-O>

Allows a pre-existing extension directory to be overwritten.

=item B<-P>

Omit the autogenerated stub POD section. 

=item B<-c>

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

=item B<-f>

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

=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<-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>

Omit the XS portion.  Used to generate templates for a module which is not
XS-based.

=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


=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 can't read or write the files involved.

=cut

my( $H2XS_VERSION ) = '$Revision: 1.16 $' =~ /\$Revision:\s+([^\s]+)/;
my $TEMPLATE_VERSION = '0.01';

use Getopt::Std;

sub usage{
	warn "@_\n" if @_;
    die "h2xs [-AOPXcfh] [-v version] [-n module_name] [headerfile [extra_libraries]]
version: $H2XS_VERSION
    -f   Force creation of the extension even if the C header does not exist.
    -n   Specify a name to use for the extension (recommended).
    -c   Omit the constant() function and specialised AUTOLOAD from the XS file.
    -A   Omit all autoloading facilities (implies -c).
    -O   Allow overwriting of a pre-existing extension directory.
    -P   Omit the stub POD section.
    -X   Omit the XS portion.
    -v   Specify a version number for this extension.
    -h   Display this help message
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("AOPXcfhv:n:") || usage;

usage if $opt_h;

if( $opt_v ){
	$TEMPLATE_VERSION = $opt_v;
}
$opt_c = 1 if $opt_A;

$path_h    = shift;
$extralibs = "@ARGV";

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


if( $path_h ){
    $name = $path_h;
    if( $path_h =~ s#::#/#g && $opt_n ){
	warn "Nesting of headerfile ignored with -n\n";
    }
    $path_h .= ".h" unless $path_h =~ /\.h$/;
    $path_h = "/usr/include/$path_h" unless $path_h =~ m#^[./]#;
    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 not (currently) processed.
    open(CH, "<$path_h") || die "Can't open $path_h: $!\n";
    while (<CH>) {
	if (/^#[ \t]*define\s+(\w+)\b\s*[^("]/) {
	    $_ = $1;
	    next if /^_.*_h_*$/i; # special case, but for what?
	    $const_names{$_}++;
	}
    }
    close(CH);
    @const_names = sort keys %const_names;
}


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

(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 ){
	$modpath = "";
	foreach (@modparts){
		mkdir("$modpath$_", 0777);
		$modpath .= "$_/";
	}
}
mkdir($modpname, 0777);
chdir($modpname) || die "Can't chdir $ext$modpname: $!\n";

if( ! $opt_X ){  # use XS, unless it was disabled
  open(XS, ">$modfname.xs") || die "Can't create $ext$modpname/$modfname.xs: $!\n";
}
open(PM, ">$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);
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 $AUTOLOAD);
END
}

print PM <<'END';

require Exporter;
END

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

# require autoloader if XS is disabled.
# if XS is enabled, require autoloader unless autoloading is disabled.
if( $opt_X || (! $opt_A) ){
	print PM <<"END";
require AutoLoader;
END
}

if( $opt_X || ($opt_c && ! $opt_A) ){
	# we won't have our own AUTOLOAD(), so we'll inherit it.
	if( ! $opt_X ) { # use DynaLoader, unless XS was disabled
		print PM <<"END";

\@ISA = qw(Exporter AutoLoader DynaLoader);
END
	}
	else{
		print PM <<"END";

\@ISA = qw(Exporter AutoLoader);
END
	}
}
else{
	# 1) we have our own AUTOLOAD(), so don't need to inherit it.
	# or
	# 2) we don't want autoloading mentioned.
	if( ! $opt_X ){ # use DynaLoader, unless XS was disabled
		print PM <<"END";

\@ISA = qw(Exporter DynaLoader);
END
	}
	else{
		print PM <<"END";

\@ISA = qw(Exporter);
END
	}
}

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.
\@EXPORT = qw(
	@const_names
);
\$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/.*:://;
    my \$val = constant(\$constname, \@_ ? \$_[0] : 0);
    if (\$! != 0) {
	if (\$! =~ /Invalid/) {
	    \$AutoLoader::AUTOLOAD = \$AUTOLOAD;
	    goto &AutoLoader::AUTOLOAD;
	}
	else {
		croak "Your vendor has not defined $module macro \$constname";
	}
    }
    eval "sub \$AUTOLOAD { \$val }";
    goto &\$AUTOLOAD;
}

END

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

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

print PM <<"END";

# Preloaded methods go here.

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

1;
__END__
END

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

$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 $module was created by h2xs. It looks like the
#author of the extension was negligent enough to leave the stub
#unedited.
#
#Blah blah blah.
#
#=head1 AUTHOR
#
#$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";
#ifdef __cplusplus
extern "C" {
#endif
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#ifdef __cplusplus
}
#endif

END
if( $path_h ){
	my($h) = $path_h;
	$h =~ s#^/usr/include/##;
print XS <<"END";
#include <$h>

END
}

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

static double
constant(name, arg)
char *name;
int arg;
{
    errno = 0;
    switch (*name) {
END

my(@AZ, @az, @under);

foreach(@const_names){
    @AZ = 'A' .. 'Z' if !@AZ && /^[A-Z]/;
    @az = 'a' .. 'z' if !@az && /^[a-z]/;
    @under = '_'  if !@under && /^_/;
}

foreach $letter (@AZ, @az, @under) {

    last if $letter eq 'a' && !@const_names;

    print XS "    case '$letter':\n";
    my($name);
    while (substr($const_names[0],0,1) eq $letter) {
	$name = shift(@const_names);
	print XS <<"END";
	if (strEQ(name, "$name"))
#ifdef $name
	    return $name;
#else
	    goto not_there;
#endif
END
    }
    print XS <<"END";
	break;
END
}
print XS <<"END";
    }
    errno = EINVAL;
    return 0;

not_there:
    errno = ENOENT;
    return 0;
}

END
}

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

MODULE = $module		PACKAGE = $module

END

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

double
constant(name,arg)
	char *		name
	int		arg

END

close XS;
} # 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( ! $opt_X ){ # print C stuff, unless XS is disabled
  print PL "    'LIBS'	=> ['$extralibs'],   # e.g., '-lm' \n";
  print PL "    'DEFINE'	=> '',     # 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 {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";

warn "Writing $ext$modpname/Changes\n";
open(EX, ">Changes") || die "Can't create $ext$modpname/Changes: $!\n";
print EX "Revision history for Perl extension $module.\n\n";
print EX "$TEMPLATE_VERSION  ",scalar localtime,"\n";
print EX "\t- original version; created by h2xs $H2XS_VERSION\n\n";
close(EX) || die "Can't close $ext$modpname/Changes: $!\n";

warn "Writing $ext$modpname/MANIFEST\n";
system '/bin/ls > MANIFEST' or system 'ls > MANIFEST';
!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 ':';