#!./miniperl

=head1 NAME

xsubpp - compiler to convert Perl XS code into C code

=head1 SYNOPSIS

B<xsubpp> [B<-C++>] [B<-except>] [B<-typemap typemap>] file.xs

=head1 DESCRIPTION

I<xsubpp> will compile XS code into C code by embedding the constructs
necessary to let C functions manipulate Perl values and creates the glue
necessary to let Perl access those functions.  The compiler uses typemaps to
determine how to map C function parameters and variables to Perl values.

The compiler will search for typemap files called I<typemap>.  It will use
the following search path to find default typemaps, with the rightmost
typemap taking precedence.

	../../../typemap:../../typemap:../typemap:typemap

=head1 OPTIONS

=over 5

=item B<-C++>

Adds ``extern "C"'' to the C code.


=item B<-except>

Adds exception handling stubs to the C code.

=item B<-typemap typemap>

Indicates that a user-supplied typemap should take precedence over the
default typemaps.  This option may be used multiple times, with the last
typemap having the highest precedence.

=back

=head1 ENVIRONMENT

No environment variables are used.

=head1 AUTHOR

Larry Wall

=head1 SEE ALSO

perl(1)

=cut

$usage = "Usage: xsubpp [-C++] [-except] [-typemap typemap] file.xs\n";

SWITCH: while ($ARGV[0] =~ s/^-//) {
    $flag = shift @ARGV;
    $spat = shift,	next SWITCH	if $flag eq 's';
    $cplusplus = 1,	next SWITCH	if $flag eq 'C++';
    $except = 1,	next SWITCH	if $flag eq 'except';
    push(@tm,shift),	next SWITCH	if $flag eq 'typemap';
    die $usage;
}
@ARGV == 1 or die $usage;
chop($pwd = `pwd`);
# Check for error message from VMS
if ($pwd =~ /unrecognized command verb/) { $Is_VMS = 1; $pwd = $ENV{DEFAULT} }
($dir, $filename) = @ARGV[0] =~ m#(.*)/(.*)#
	or ($dir, $filename) = @ARGV[0] =~ m#(.*[>\]])(.*)#
	or ($dir, $filename) = ('.', $ARGV[0]);
chdir($dir);

$typemap = shift @ARGV;
foreach $typemap (@tm) {
    die "Can't find $typemap in $pwd\n" unless -r $typemap;
}
unshift @tm, qw(../../../../lib/ExtUtils/typemap ../../../lib/ExtUtils/typemap
                ../../lib/ExtUtils/typemap ../../../typemap ../../typemap
                ../typemap typemap);
foreach $typemap (@tm) {
    open(TYPEMAP, $typemap) || next;
    $mode = Typemap;
    $current = \$junk;
    while (<TYPEMAP>) {
	next if /^#/;
	if (/^INPUT\s*$/) { $mode = Input, next }
	if (/^OUTPUT\s*$/) { $mode = Output, next }
	if (/^TYPEMAP\s*$/) { $mode = Typemap, next }
	if ($mode eq Typemap) {
	    chop;
	    ($typename, $kind) = split(/\t+/, $_, 2);
	    $type_kind{$typename} = $kind if $kind ne '';
	}
	elsif ($mode eq Input) {
	    if (/^\s/) {
		$$current .= $_;
	    }
	    else {
		s/\s*$//;
		$input_expr{$_} = '';
		$current = \$input_expr{$_};
	    }
	}
	else {
	    if (/^\s/) {
		$$current .= $_;
	    }
	    else {
		s/\s*$//;
		$output_expr{$_} = '';
		$current = \$output_expr{$_};
	    }
	}
    }
    close(TYPEMAP);
}

foreach $key (keys %input_expr) {
    $input_expr{$key} =~ s/\n+$//;
}

sub Q {
    local $text = shift;
    $text =~ tr/#//d;
    $text =~ s/\[\[/{/g;
    $text =~ s/\]\]/}/g;
    $text;
}

open(F, $filename) || die "cannot open $filename\n";

while (<F>) {
    last if ($Module, $foo, $Package, $foo1, $Prefix) =
	/^MODULE\s*=\s*([\w:]+)(\s+PACKAGE\s*=\s*([\w:]+))?(\s+PREFIX\s*=\s*(\S+))?\s*$/;
    print $_;
}
exit 0 if $_ eq "";
$lastline = $_;

sub fetch_para {
    # parse paragraph
    @line = ();
    if ($lastline ne "") {
	if ($lastline =~
    /^MODULE\s*=\s*([\w:]+)(\s+PACKAGE\s*=\s*([\w:]+))?(\s+PREFIX\s*=\s*(\S+))?\s*$/) {
	    $Module = $1;
	    $foo = $2;
	    $Package = $3;
	    $foo1 = $4;
	    $Prefix = $5;
	    ($Module_cname = $Module) =~ s/\W/_/g;
	    ($Packid = $Package) =~ s/:/_/g;
	    $Packprefix = $Package;
	    $Packprefix .= "::" if defined $Packprefix && $Packprefix ne "";
	    while (<F>) {
		chop;
		next if /^#/ &&
		    !/^#[ \t]*(if|ifdef|ifndef|else|elif|endif|define|undef)\b/;
		last if /^\S/;
	    }
	    push(@line, $_) if $_ ne "";
	}
	else {
	    push(@line, $lastline);
	}
	$lastline = "";
	while (<F>) {
	    next if /^#/ &&
		!/^#[ \t]*(if|ifdef|ifndef|else|elif|endif|define|undef)\b/;
	    chop;
	    if (/^\S/ && @line && $line[-1] eq "") {
		$lastline = $_;
		last;
	    }
	    else {
		push(@line, $_);
	    }
	}
	pop(@line) while @line && $line[-1] =~ /^\s*$/;
    }
    $PPCODE = grep(/PPCODE:/, @line);
    scalar @line;
}

while (&fetch_para) {
    # initialize info arrays
    undef(%args_match);
    undef(%var_types);
    undef(%var_addr);
    undef(%defaults);
    undef($class);
    undef($static);
    undef($elipsis);

    # extract return type, function name and arguments
    $ret_type = shift(@line);
    if ($ret_type =~ /^BOOT:/) {
        push (@BootCode, @line, "", "") ;
        next ;
    }
    if ($ret_type =~ /^static\s+(.*)$/) {
	    $static = 1;
	    $ret_type = $1;
    }
    $func_header = shift(@line);
    ($func_name, $orig_args) =  $func_header =~ /^([\w:]+)\s*\((.*)\)$/;
    if ($func_name =~ /(.*)::(.*)/) {
	    $class = $1;
	    $func_name = $2;
    }
    ($pname = $func_name) =~ s/^($Prefix)?/$Packprefix/;
    push(@Func_name, "${Packid}_$func_name");
    push(@Func_pname, $pname);
    @args = split(/\s*,\s*/, $orig_args);
    if (defined($class)) {
	if (defined($static)) {
	    unshift(@args, "CLASS");
	    $orig_args = "CLASS, $orig_args";
	    $orig_args =~ s/^CLASS, $/CLASS/;
	}
	else {
	    unshift(@args, "THIS");
	    $orig_args = "THIS, $orig_args";
	    $orig_args =~ s/^THIS, $/THIS/;
	}
    }
    $orig_args =~ s/"/\\"/g;
    $min_args = $num_args = @args;
    foreach $i (0..$num_args-1) {
	    if ($args[$i] =~ s/\.\.\.//) {
		    $elipsis = 1;
		    $min_args--;
		    if ($args[i] eq '' && $i == $num_args - 1) {
			pop(@args);
			last;
		    }
	    }
	    if ($args[$i] =~ /([^=]*\S)\s*=\s*(.*)/) {
		    $min_args--;
		    $args[$i] = $1;
		    $defaults{$args[$i]} = $2;
		    $defaults{$args[$i]} =~ s/"/\\"/g;
	    }
    }
    if (defined($class)) {
	    $func_args = join(", ", @args[1..$#args]);
    } else {
	    $func_args = join(", ", @args);
    }
    @args_match{@args} = 1..@args;

    # print function header
    print Q<<"EOF";
#XS(XS_${Packid}_$func_name)
#[[
#    dXSARGS;
EOF
    if ($elipsis) {
	$cond = qq(items < $min_args);
    }
    elsif ($min_args == $num_args) {
	$cond = qq(items != $min_args);
    }
    else {
	$cond = qq(items < $min_args || items > $num_args);
    }

    print Q<<"EOF" if $except;
#    char errbuf[1024];
#    *errbuf = '\0';
EOF

    print Q<<"EOF";
#    if ($cond) {
#	croak("Usage: $pname($orig_args)");
#    }
EOF

    print Q<<"EOF" if $PPCODE;
#    SP -= items;
EOF

    # Now do a block of some sort.

    $condnum = 0;
    if (!@line) {
	@line = "CLEANUP:";
    }
    while (@line) {
	if ($_[0] =~ s/^\s*CASE\s*:\s*//) {
	    $cond = shift(@line);
	    if ($condnum == 0) {
		print "    if ($cond)\n";
	    }
	    elsif ($cond ne '') {
		print "    else if ($cond)\n";
	    }
	    else {
		print "    else\n";
	    }
	    $condnum++;
	}

	if ($except) {
	    print Q<<"EOF";
#    TRY [[
EOF
	}
	else {
	    print Q<<"EOF";
#    [[
EOF
	}

	# do initialization of input variables
	$thisdone = 0;
	$retvaldone = 0;
	$deferred = "";
	while (@line) {
		$_ = shift(@line);
		last if /^\s*NOT_IMPLEMENTED_YET/;
		last if /^\s*(PPCODE|CODE|OUTPUT|CLEANUP|CASE)\s*:/;
		($var_type, $var_name, $var_init) =
		    /\s*([^\t]+)\s*([^\s=]+)\s*(=.*)?/;
		# Catch common errors. More error checking required here.
		blurt("Error: no tab in $pname argument declaration '$_'\n")
			unless (m/\S+\s*\t\s*\S+/);
		# catch C style argument declaration (this could be made alowable syntax)
		warn("Warning: ignored semicolon in $pname argument declaration '$_'\n")
			if ($var_name =~ s/;//g); # eg SV *<tab>name;
		# catch many errors similar to: SV<tab>* name
		blurt("Error: invalid $pname argument name '$var_name' (type '$var_type')\n")
			unless ($var_name =~ m/^&?\w+$/);
		if ($var_name =~ /^&/) {
			$var_name =~ s/^&//;
			$var_addr{$var_name} = 1;
		}
		$thisdone |= $var_name eq "THIS";
		$retvaldone |= $var_name eq "RETVAL";
		$var_types{$var_name} = $var_type;
		print "\t" . &map_type($var_type);
		$var_num = $args_match{$var_name};
		if ($var_addr{$var_name}) {
			$func_args =~ s/\b($var_name)\b/&\1/;
		}
		if ($var_init !~ /^=\s*NO_INIT\s*$/) {
			if ($var_init !~ /^\s*$/) {
				&output_init($var_type, $var_num,
				    "$var_name $var_init");
			} elsif ($var_num) {
				# generate initialization code
				&generate_init($var_type, $var_num, $var_name);
			} else {
				print ";\n";
			}
		} else {
			print "\t$var_name;\n";
		}
	}
	if (!$thisdone && defined($class)) {
	    if (defined($static)) {
		print "\tchar *";
		$var_types{"CLASS"} = "char *";
		&generate_init("char *", 1, "CLASS");
	    }
	    else {
		print "\t$class *";
		$var_types{"THIS"} = "$class *";
		&generate_init("$class *", 1, "THIS");
	    }
	}

	# do code
	if (/^\s*NOT_IMPLEMENTED_YET/) {
		print "\ncroak(\"$pname: not implemented yet\");\n";
	} else {
		if ($ret_type ne "void") {
			print "\t" . &map_type($ret_type) . "\tRETVAL;\n"
				if !$retvaldone;
			$args_match{"RETVAL"} = 0;
			$var_types{"RETVAL"} = $ret_type;
		}
		if (/^\s*PPCODE:/) {
			print $deferred;
			while (@line) {
				$_ = shift(@line);
				die "PPCODE must be last thing"
				    if /^\s*(OUTPUT|CLEANUP|CASE)\s*:/;
				print "$_\n";
			}
			print "\tPUTBACK;\n\treturn;\n";
		} elsif (/^\s*CODE:/) {
			print $deferred;
			while (@line) {
				$_ = shift(@line);
				last if /^\s*(OUTPUT|CLEANUP|CASE)\s*:/;
				print "$_\n";
			}
		} elsif ($func_name eq "DESTROY") {
			print $deferred;
			print "\n\t";
			print "delete THIS;\n"
		} else {
			print $deferred;
			print "\n\t";
			if ($ret_type ne "void") {
				print "RETVAL = ";
			}
			if (defined($static)) {
			    if ($func_name =~ /^new/) {
				$func_name = "$class";
			    }
			    else {
				print "$class::";
			    }
			} elsif (defined($class)) {
				print "THIS->";
			}
			if (defined($spat) && $func_name =~ /^($spat)(.*)$/) {
				$func_name = $2;
			}
			print "$func_name($func_args);\n";
			&generate_output($ret_type, 0, "RETVAL")
			    unless $ret_type eq "void";
		}
	}

	# do output variables
	if (/^\s*OUTPUT\s*:/) {
		while (@line) {
			$_ = shift(@line);
			last if /^\s*CLEANUP\s*:/;
			s/^\s+//;
			($outarg, $outcode) = split(/\t+/);
			if ($outcode) {
			    print "\t$outcode\n";
			} else {
				die "$outarg not an argument"
				    unless defined($args_match{$outarg});
				$var_num = $args_match{$outarg};
				&generate_output($var_types{$outarg}, $var_num,
				    $outarg); 
			}
		}
	}
	# do cleanup
	if (/^\s*CLEANUP\s*:/) {
	    while (@line) {
		    $_ = shift(@line);
		    last if /^\s*CASE\s*:/;
		    print "$_\n";
	    }
	}
	# print function trailer
	if ($except) {
	    print Q<<EOF;
#    ]]
#    BEGHANDLERS
#    CATCHALL
#	sprintf(errbuf, "%s: %s\\tpropagated", Xname, Xreason);
#    ENDHANDLERS
EOF
	}
	else {
	    print Q<<EOF;
#    ]]
EOF
	}
	if (/^\s*CASE\s*:/) {
	    unshift(@line, $_);
	}
    }

    print Q<<EOF if $except;
#    if (errbuf[0])
#	croak(errbuf);
EOF

    print Q<<EOF unless $PPCODE;
#    XSRETURN(1);
EOF

    print Q<<EOF;
#]]
#
EOF
}

# print initialization routine
print qq/extern "C"\n/ if $cplusplus;
print Q<<"EOF";
#XS(boot_$Module_cname)
#[[
#    dXSARGS;
#    char* file = __FILE__;
#
EOF

for (@Func_name) {
    $pname = shift(@Func_pname);
    print "    newXS(\"$pname\", XS_$_, file);\n";
}

if (@BootCode)
{
    print "\n    /* Initialisation Section */\n\n" ;
    print grep (s/$/\n/, @BootCode) ;
    print "    /* End of Initialisation Section */\n\n" ;
}

print "    ST(0) = &sv_yes;\n";
print "    XSRETURN(1);\n";
print "}\n";

sub output_init {
    local($type, $num, $init) = @_;
    local($arg) = "ST(" . ($num - 1) . ")";

    eval qq/print " $init\\\n"/;
}

sub blurt { warn @_; $errors++ }

sub generate_init {
    local($type, $num, $var) = @_;
    local($arg) = "ST(" . ($num - 1) . ")";
    local($argoff) = $num - 1;
    local($ntype);
    local($tk);

    blurt("'$type' not in typemap"), return unless defined($type_kind{$type});
    ($ntype = $type) =~ s/\s*\*/Ptr/g;
    $subtype = $ntype;
    $subtype =~ s/Ptr$//;
    $subtype =~ s/Array$//;
    $tk = $type_kind{$type};
    $tk =~ s/OBJ$/REF/ if $func_name =~ /DESTROY$/;
    $type =~ s/:/_/g;
    $expr = $input_expr{$tk};
    if ($expr =~ /DO_ARRAY_ELEM/) {
	$subexpr = $input_expr{$type_kind{$subtype}};
	$subexpr =~ s/ntype/subtype/g;
	$subexpr =~ s/\$arg/ST(ix_$var)/g;
	$subexpr =~ s/\n\t/\n\t\t/g;
	$subexpr =~ s/is not of (.*")/[arg %d] is not of $1, ix_$var + 1/g;
	$subexpr =~ s/\$var/${var}[ix_$var - $argoff]/;
	$expr =~ s/DO_ARRAY_ELEM/$subexpr/;
    }
    if (defined($defaults{$var})) {
	    $expr =~ s/(\t+)/$1    /g;
	    $expr =~ s/        /\t/g;
	    eval qq/print "\\t$var;\\n"/;
	    $deferred .= eval qq/"\\n\\tif (items < $num)\\n\\t    $var = $defaults{$var};\\n\\telse {\\n$expr;\\n\\t}\\n"/;
    } elsif ($expr !~ /^\t\$var =/) {
	    eval qq/print "\\t$var;\\n"/;
	    $deferred .= eval qq/"\\n$expr;\\n"/;
    } else {
	    eval qq/print "$expr;\\n"/;
    }
}

sub generate_output {
    local($type, $num, $var) = @_;
    local($arg) = "ST(" . ($num - ($num != 0)) . ")";
    local($argoff) = $num - 1;
    local($ntype);

    if ($type =~ /^array\(([^,]*),(.*)\)/) {
	    print "\tsv_setpvn($arg, (char *)$var, $2 * sizeof($1)), XFree((char *)$var);\n";
    } else {
	    blurt("'$type' not in typemap"), return
		unless defined($type_kind{$type});
	    ($ntype = $type) =~ s/\s*\*/Ptr/g;
	    $ntype =~ s/\(\)//g;
	    $subtype = $ntype;
	    $subtype =~ s/Ptr$//;
	    $subtype =~ s/Array$//;
	    $expr = $output_expr{$type_kind{$type}};
	    if ($expr =~ /DO_ARRAY_ELEM/) {
		$subexpr = $output_expr{$type_kind{$subtype}};
		$subexpr =~ s/ntype/subtype/g;
		$subexpr =~ s/\$arg/ST(ix_$var)/g;
		$subexpr =~ s/\$var/${var}[ix_$var]/g;
		$subexpr =~ s/\n\t/\n\t\t/g;
		$expr =~ s/DO_ARRAY_ELEM\n/$subexpr/;
		eval "print qq\a$expr\a";
	    }
	    elsif ($var eq 'RETVAL') {
		if ($expr =~ /^\t\$arg = /) {
		    eval "print qq\a$expr\a";
		    print "\tsv_2mortal(ST(0));\n";
		}
		else {
		    print "\tST(0) = sv_newmortal();\n";
		    eval "print qq\a$expr\a";
		}
	    }
	    elsif ($arg =~ /^ST\(\d+\)$/) {
		eval "print qq\a$expr\a";
	    }
	    elsif ($arg =~ /^ST\(\d+\)$/) {
		eval "print qq\a$expr\a";
	    }
	    elsif ($arg =~ /^ST\(\d+\)$/) {
		eval "print qq\a$expr\a";
	    }
    }
}

sub map_type {
    local($type) = @_;

    $type =~ s/:/_/g;
    if ($type =~ /^array\(([^,]*),(.*)\)/) {
	    return "$1 *";
    } else {
	    return $type;
    }
}

# If this is VMS, the exit status has meaning to the shell, so we
# use a predictable value (SS$_Abort) rather than an arbitrary
# number.
exit $Is_VMS ? 44 : $errors;