#! /usr/bin/env perl

# Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.

#

# Licensed under the OpenSSL license (the "License").  You may not use

# this file except in compliance with the License.  You can obtain a copy

# in the file LICENSE in the source distribution or at

# https://www.openssl.org/source/license.html

use strict;

my $flavour = shift;

my $output = shift;

open STDOUT,">$output" || die "can't open $output: $!";

$flavour = "linux32" if (!$flavour or $flavour eq "void");

my %GLOBALS;

my $dotinlocallabels=($flavour=~/linux/)?1:0;

################################################################

# directives which need special treatment on different platforms

################################################################

my $arch = sub {

    if ($flavour =~ /linux/)	{ ".arch\t".join(',',@_); }

    else			{ ""; }

};

my $fpu = sub {

    if ($flavour =~ /linux/)	{ ".fpu\t".join(',',@_); }

    else			{ ""; }

};

my $hidden = sub {

    if ($flavour =~ /ios/)	{ ".private_extern\t".join(',',@_); }

    else			{ ".hidden\t".join(',',@_); }

};

my $comm = sub {

    my @args = split(/,\s*/,shift);

    my $name = @args[0];

    my $global = \$GLOBALS{$name};

    my $ret;

    if ($flavour =~ /ios32/)	{

	$ret = ".comm\t_$name,@args[1]\n";

	$ret .= ".non_lazy_symbol_pointer\n";

	$ret .= "$name:\n";

	$ret .= ".indirect_symbol\t_$name\n";

	$ret .= ".long\t0";

	$name = "_$name";

    } else			{ $ret = ".comm\t".join(',',@args); }

    $$global = $name;

    $ret;

};

my $globl = sub {

    my $name = shift;

    my $global = \$GLOBALS{$name};

    my $ret;

    SWITCH: for ($flavour) {

	/ios/		&& do { $name = "_$name";

				last;

			      };

    }

    $ret = ".globl	$name" if (!$ret);

    $$global = $name;

    $ret;

};

my $global = $globl;

my $extern = sub {

    &$globl(@_);

    return;	# return nothing

};

my $type = sub {

    if ($flavour =~ /linux/)	{ ".type\t".join(',',@_); }

    elsif ($flavour =~ /ios32/)	{ if (join(',',@_) =~ /(\w+),%function/) {

					"#ifdef __thumb2__\n".

					".thumb_func	$1\n".

					"#endif";

				  }

			        }

    else			{ ""; }

};

my $size = sub {

    if ($flavour =~ /linux/)	{ ".size\t".join(',',@_); }

    else			{ ""; }

};

my $inst = sub {

    if ($flavour =~ /linux/)    { ".inst\t".join(',',@_); }

    else                        { ".long\t".join(',',@_); }

};

my $asciz = sub {

    my $line = join(",",@_);

    if ($line =~ /^"(.*)"$/)

    {	".byte	" . join(",",unpack("C*",$1),0) . "\n.align	2";	}

    else

    {	"";	}

};

sub range {

  my ($r,$sfx,$start,$end) = @_;

    join(",",map("$r$_$sfx",($start..$end)));

}

sub expand_line {

  my $line = shift;

  my @ret = ();

    pos($line)=0;

    while ($line =~ m/\G[^@\/\{\"]*/g) {

	if ($line =~ m/\G(@|\/\/|$)/gc) {

	    last;

	}

	elsif ($line =~ m/\G\{/gc) {

	    my $saved_pos = pos($line);

	    $line =~ s/\G([rdqv])([0-9]+)([^\-]*)\-\1([0-9]+)\3/range($1,$3,$2,$4)/e;

	    pos($line) = $saved_pos;

	    $line =~ m/\G[^\}]*\}/g;

	}

	elsif ($line =~ m/\G\"/gc) {

	    $line =~ m/\G[^\"]*\"/g;

	}

    }

    $line =~ s/\b(\w+)/$GLOBALS{$1} or $1/ge;

    return $line;

}

while(my $line=<>) {

    if ($line =~ m/^\s*(#|@|\/\/)/)	{ print $line; next; }

    $line =~ s|/\*.*\*/||;	# get rid of C-style comments...

    $line =~ s|^\s+||;		# ... and skip white spaces in beginning...

    $line =~ s|\s+$||;		# ... and at the end

    {

	$line =~ s|[\b\.]L(\w{2,})|L$1|g;	# common denominator for Locallabel

	$line =~ s|\bL(\w{2,})|\.L$1|g	if ($dotinlocallabels);

    }

    {

	$line =~ s|(^[\.\w]+)\:\s*||;

	my $label = $1;

	if ($label) {

	    printf "%s:",($GLOBALS{$label} or $label);

	}

    }

    if ($line !~ m/^[#@]/) {

	$line =~ s|^\s*(\.?)(\S+)\s*||;

	my $c = $1; $c = "\t" if ($c eq "");

	my $mnemonic = $2;

	my $opcode;

	if ($mnemonic =~ m/([^\.]+)\.([^\.]+)/) {

	    $opcode = eval("\$$1_$2");

	} else {

	    $opcode = eval("\$$mnemonic");

	}

	my $arg=expand_line($line);

	if (ref($opcode) eq 'CODE') {

		$line = &$opcode($arg);

	} elsif ($mnemonic)         {

		$line = $c.$mnemonic;

		$line.= "\t$arg" if ($arg ne "");

	}

    }

    print $line if ($line);

    print "\n";

}

close STDOUT or die "error closing STDOUT: $!";