#! /usr/bin/env perl

# Copyright 2005-2020 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

# Ascetic x86_64 AT&T to MASM/NASM assembler translator by <appro>.

#

# Why AT&T to MASM and not vice versa? Several reasons. Because AT&T

# format is way easier to parse. Because it's simpler to "gear" from

# Unix ABI to Windows one [see cross-reference "card" at the end of

# file]. Because Linux targets were available first...

#

# In addition the script also "distills" code suitable for GNU

# assembler, so that it can be compiled with more rigid assemblers,

# such as Solaris /usr/ccs/bin/as.

#

# This translator is not designed to convert *arbitrary* assembler

# code from AT&T format to MASM one. It's designed to convert just

# enough to provide for dual-ABI OpenSSL modules development...

# There *are* limitations and you might have to modify your assembler

# code or this script to achieve the desired result...

#

# Currently recognized limitations:

#

# - can't use multiple ops per line;

#

# Dual-ABI styling rules.

#

# 1. Adhere to Unix register and stack layout [see cross-reference

#    ABI "card" at the end for explanation].

# 2. Forget about "red zone," stick to more traditional blended

#    stack frame allocation. If volatile storage is actually required

#    that is. If not, just leave the stack as is.

# 3. Functions tagged with ".type name,@function" get crafted with

#    unified Win64 prologue and epilogue automatically. If you want

#    to take care of ABI differences yourself, tag functions as

#    ".type name,@abi-omnipotent" instead.

# 4. To optimize the Win64 prologue you can specify number of input

#    arguments as ".type name,@function,N." Keep in mind that if N is

#    larger than 6, then you *have to* write "abi-omnipotent" code,

#    because >6 cases can't be addressed with unified prologue.

# 5. Name local labels as .L*, do *not* use dynamic labels such as 1:

#    (sorry about latter).

# 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is

#    required to identify the spots, where to inject Win64 epilogue!

#    But on the pros, it's then prefixed with rep automatically:-)

# 7. Stick to explicit ip-relative addressing. If you have to use

#    GOTPCREL addressing, stick to mov symbol@GOTPCREL(%rip),%r??.

#    Both are recognized and translated to proper Win64 addressing

#    modes.

#

# 8. In order to provide for structured exception handling unified

#    Win64 prologue copies %rsp value to %rax. For further details

#    see SEH paragraph at the end.

# 9. .init segment is allowed to contain calls to functions only.

# a. If function accepts more than 4 arguments *and* >4th argument

#    is declared as non 64-bit value, do clear its upper part.

use strict;

my $flavour = shift;

my $output  = shift;

if ($flavour =~ /\./) { $output = $flavour; undef $flavour; }

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

	if (defined($output));

my $gas=1;	$gas=0 if ($output =~ /\.asm$/);

my $elf=1;	$elf=0 if (!$gas);

my $win64=0;

my $prefix="";

my $decor=".L";

my $masmref=8 + 50727*2**-32;	# 8.00.50727 shipped with VS2005

my $masm=0;

my $PTR=" PTR";

my $nasmref=2.03;

my $nasm=0;

if    ($flavour eq "mingw64")	{ $gas=1; $elf=0; $win64=1;

				  $prefix=`echo __USER_LABEL_PREFIX__ | $ENV{CC} -E -P -`;

				  $prefix =~ s|\R$||; # Better chomp

				}

elsif ($flavour eq "macosx")	{ $gas=1; $elf=0; $prefix="_"; $decor="L\$"; }

elsif ($flavour eq "masm")	{ $gas=0; $elf=0; $masm=$masmref; $win64=1; $decor="\$L\$"; }

elsif ($flavour eq "nasm")	{ $gas=0; $elf=0; $nasm=$nasmref; $win64=1; $decor="\$L\$"; $PTR=""; }

elsif (!$gas)

{   if ($ENV{ASM} =~ m/nasm/ && `nasm -v` =~ m/version ([0-9]+)\.([0-9]+)/i)

    {	$nasm = $1 + $2*0.01; $PTR="";  }

    elsif (`ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/)

    {	$masm = $1 + $2*2**-16 + $4*2**-32;   }

    die "no assembler found on %PATH%" if (!($nasm || $masm));

    $win64=1;

    $elf=0;

    $decor="\$L\$";

}

my $cet_property;

if ($flavour =~ /elf/) {

	# Always generate .note.gnu.property section for ELF outputs to

	# mark Intel CET support since all input files must be marked

	# with Intel CET support in order for linker to mark output with

	# Intel CET support.

	my $p2align=3; $p2align=2 if ($flavour eq "elf32");

	$cet_property = <<_____;

	.section ".note.gnu.property", "a"

	.p2align $p2align

	.long 1f - 0f

	.long 4f - 1f

	.long 5

0:

	.asciz "GNU"

1:

	.p2align $p2align

	.long 0xc0000002

	.long 3f - 2f

2:

	.long 3

3:

	.p2align $p2align

4:

_____

}

my $current_segment;

my $current_function;

my %globals;

{ package opcode;	# pick up opcodes

    sub re {

	my	($class, $line) = @_;

	my	$self = {};

	my	$ret;

	if ($$line =~ /^([a-z][a-z0-9]*)/i) {

	    bless $self,$class;

	    $self->{op} = $1;

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	    undef $self->{sz};

	    if ($self->{op} =~ /^(movz)x?([bw]).*/) {	# movz is pain...

		$self->{op} = $1;

		$self->{sz} = $2;

	    } elsif ($self->{op} =~ /call|jmp/) {

		$self->{sz} = "";

	    } elsif ($self->{op} =~ /^p/ && $' !~ /^(ush|op|insrw)/) { # SSEn

		$self->{sz} = "";

	    } elsif ($self->{op} =~ /^[vk]/) { # VEX or k* such as kmov

		$self->{sz} = "";

	    } elsif ($self->{op} =~ /mov[dq]/ && $$line =~ /%xmm/) {

		$self->{sz} = "";

	    } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) {

		$self->{op} = $1;

		$self->{sz} = $2;

	    }

	}

	$ret;

    }

    sub size {

	my ($self, $sz) = @_;

	$self->{sz} = $sz if (defined($sz) && !defined($self->{sz}));

	$self->{sz};

    }

    sub out {

	my $self = shift;

	if ($gas) {

	    if ($self->{op} eq "movz") {	# movz is pain...

		sprintf "%s%s%s",$self->{op},$self->{sz},shift;

	    } elsif ($self->{op} =~ /^set/) {

		"$self->{op}";

	    } elsif ($self->{op} eq "ret") {

		my $epilogue = "";

		if ($win64 && $current_function->{abi} eq "svr4") {

		    $epilogue = "movq	8(%rsp),%rdi\n\t" .

				"movq	16(%rsp),%rsi\n\t";

		}

	    	$epilogue . ".byte	0xf3,0xc3";

	    } elsif ($self->{op} eq "call" && !$elf && $current_segment eq ".init") {

		".p2align\t3\n\t.quad";

	    } else {

		"$self->{op}$self->{sz}";

	    }

	} else {

	    $self->{op} =~ s/^movz/movzx/;

	    if ($self->{op} eq "ret") {

		$self->{op} = "";

		if ($win64 && $current_function->{abi} eq "svr4") {

		    $self->{op} = "mov	rdi,QWORD$PTR\[8+rsp\]\t;WIN64 epilogue\n\t".

				  "mov	rsi,QWORD$PTR\[16+rsp\]\n\t";

	    	}

		$self->{op} .= "DB\t0F3h,0C3h\t\t;repret";

	    } elsif ($self->{op} =~ /^(pop|push)f/) {

		$self->{op} .= $self->{sz};

	    } elsif ($self->{op} eq "call" && $current_segment eq ".CRT\$XCU") {

		$self->{op} = "\tDQ";

	    }

	    $self->{op};

	}

    }

    sub mnemonic {

	my ($self, $op) = @_;

	$self->{op}=$op if (defined($op));

	$self->{op};

    }

}

{ package const;	# pick up constants, which start with $

    sub re {

	my	($class, $line) = @_;

	my	$self = {};

	my	$ret;

	if ($$line =~ /^\$([^,]+)/) {

	    bless $self, $class;

	    $self->{value} = $1;

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	}

	$ret;

    }

    sub out {

    	my $self = shift;

	$self->{value} =~ s/\b(0b[0-1]+)/oct($1)/eig;

	if ($gas) {

	    # Solaris /usr/ccs/bin/as can't handle multiplications

	    # in $self->{value}

	    my $value = $self->{value};

	    no warnings;    # oct might complain about overflow, ignore here...

	    $value =~ s/(?

	    if ($value =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg) {

		$self->{value} = $value;

	    }

	    sprintf "\$%s",$self->{value};

	} else {

	    my $value = $self->{value};

	    $value =~ s/0x([0-9a-f]+)/0$1h/ig if ($masm);

	    sprintf "%s",$value;

	}

    }

}

{ package ea;		# pick up effective addresses: expr(%reg,%reg,scale)

    my %szmap = (	b=>"BYTE$PTR",    w=>"WORD$PTR",

			l=>"DWORD$PTR",   d=>"DWORD$PTR",

			q=>"QWORD$PTR",   o=>"OWORD$PTR",

			x=>"XMMWORD$PTR", y=>"YMMWORD$PTR",

			z=>"ZMMWORD$PTR" ) if (!$gas);

    sub re {

	my	($class, $line, $opcode) = @_;

	my	$self = {};

	my	$ret;

	# optional * ----vvv--- appears in indirect jmp/call

	if ($$line =~ /^(\*?)([^\(,]*)\(([%\w,]+)\)((?:{[^}]+})*)/) {

	    bless $self, $class;

	    $self->{asterisk} = $1;

	    $self->{label} = $2;

	    ($self->{base},$self->{index},$self->{scale})=split(/,/,$3);

	    $self->{scale} = 1 if (!defined($self->{scale}));

	    $self->{opmask} = $4;

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	    if ($win64 && $self->{label} =~ s/\@GOTPCREL//) {

		die if ($opcode->mnemonic() ne "mov");

		$opcode->mnemonic("lea");

	    }

	    $self->{base}  =~ s/^%//;

	    $self->{index} =~ s/^%// if (defined($self->{index}));

	    $self->{opcode} = $opcode;

	}

	$ret;

    }

    sub size {}

    sub out {

	my ($self, $sz) = @_;

	$self->{label} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei;

	$self->{label} =~ s/\.L/$decor/g;

	# Silently convert all EAs to 64-bit. This is required for

	# elder GNU assembler and results in more compact code,

	# *but* most importantly AES module depends on this feature!

	$self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;

	$self->{base}  =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;

	# Solaris /usr/ccs/bin/as can't handle multiplications

	# in $self->{label}...

	use integer;

	$self->{label} =~ s/(?

	$self->{label} =~ s/\b([0-9]+\s*[\*\/\%]\s*[0-9]+)\b/eval($1)/eg;

	# Some assemblers insist on signed presentation of 32-bit

	# offsets, but sign extension is a tricky business in perl...

	if ((1<<31)<<1) {

	    $self->{label} =~ s/\b([0-9]+)\b/$1<<32>>32/eg;

	} else {

	    $self->{label} =~ s/\b([0-9]+)\b/$1>>0/eg;

	}

	# if base register is %rbp or %r13, see if it's possible to

	# flip base and index registers [for better performance]

	if (!$self->{label} && $self->{index} && $self->{scale}==1 &&

	    $self->{base} =~ /(rbp|r13)/) {

		$self->{base} = $self->{index}; $self->{index} = $1;

	}

	if ($gas) {

	    $self->{label} =~ s/^___imp_/__imp__/   if ($flavour eq "mingw64");

	    if (defined($self->{index})) {

		sprintf "%s%s(%s,%%%s,%d)%s",

					$self->{asterisk},$self->{label},

					$self->{base}?"%$self->{base}":"",

					$self->{index},$self->{scale},

					$self->{opmask};

	    } else {

		sprintf "%s%s(%%%s)%s",	$self->{asterisk},$self->{label},

					$self->{base},$self->{opmask};

	    }

	} else {

	    $self->{label} =~ s/\./\$/g;

	    $self->{label} =~ s/(?

	    $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/);

	    my $mnemonic = $self->{opcode}->mnemonic();

	    ($self->{asterisk})				&& ($sz="q") ||

	    ($mnemonic =~ /^v?mov([qd])$/)		&& ($sz=$1)  ||

	    ($mnemonic =~ /^v?pinsr([qdwb])$/)		&& ($sz=$1)  ||

	    ($mnemonic =~ /^vpbroadcast([qdwb])$/)	&& ($sz=$1)  ||

	    ($mnemonic =~ /^v(?!perm)[a-z]+[fi]128$/)	&& ($sz="x");

	    $self->{opmask}  =~ s/%(k[0-7])/$1/;

	    if (defined($self->{index})) {

		sprintf "%s[%s%s*%d%s]%s",$szmap{$sz},

					$self->{label}?"$self->{label}+":"",

					$self->{index},$self->{scale},

					$self->{base}?"+$self->{base}":"",

					$self->{opmask};

	    } elsif ($self->{base} eq "rip") {

		sprintf "%s[%s]",$szmap{$sz},$self->{label};

	    } else {

		sprintf "%s[%s%s]%s",	$szmap{$sz},

					$self->{label}?"$self->{label}+":"",

					$self->{base},$self->{opmask};

	    }

	}

    }

}

{ package register;	# pick up registers, which start with %.

    sub re {

	my	($class, $line, $opcode) = @_;

	my	$self = {};

	my	$ret;

	# optional * ----vvv--- appears in indirect jmp/call

	if ($$line =~ /^(\*?)%(\w+)((?:{[^}]+})*)/) {

	    bless $self,$class;

	    $self->{asterisk} = $1;

	    $self->{value} = $2;

	    $self->{opmask} = $3;

	    $opcode->size($self->size());

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	}

	$ret;

    }

    sub size {

	my	$self = shift;

	my	$ret;

	if    ($self->{value} =~ /^r[\d]+b$/i)	{ $ret="b"; }

	elsif ($self->{value} =~ /^r[\d]+w$/i)	{ $ret="w"; }

	elsif ($self->{value} =~ /^r[\d]+d$/i)	{ $ret="l"; }

	elsif ($self->{value} =~ /^r[\w]+$/i)	{ $ret="q"; }

	elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; }

	elsif ($self->{value} =~ /^[\w]{2}l$/i)	{ $ret="b"; }

	elsif ($self->{value} =~ /^[\w]{2}$/i)	{ $ret="w"; }

	elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; }

	$ret;

    }

    sub out {

    	my $self = shift;

	if ($gas)	{ sprintf "%s%%%s%s",	$self->{asterisk},

						$self->{value},

						$self->{opmask}; }

	else		{ $self->{opmask} =~ s/%(k[0-7])/$1/;

			  $self->{value}.$self->{opmask}; }

    }

}

{ package label;	# pick up labels, which end with :

    sub re {

	my	($class, $line) = @_;

	my	$self = {};

	my	$ret;

	if ($$line =~ /(^[\.\w]+)\:/) {

	    bless $self,$class;

	    $self->{value} = $1;

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	    $self->{value} =~ s/^\.L/$decor/;

	}

	$ret;

    }

    sub out {

	my $self = shift;

	if ($gas) {

	    my $func = ($globals{$self->{value}} or $self->{value}) . ":";

	    if ($win64	&& $current_function->{name} eq $self->{value}

			&& $current_function->{abi} eq "svr4") {

		$func .= "\n";

		$func .= "	movq	%rdi,8(%rsp)\n";

		$func .= "	movq	%rsi,16(%rsp)\n";

		$func .= "	movq	%rsp,%rax\n";

		$func .= "${decor}SEH_begin_$current_function->{name}:\n";

		my $narg = $current_function->{narg};

		$narg=6 if (!defined($narg));

		$func .= "	movq	%rcx,%rdi\n" if ($narg>0);

		$func .= "	movq	%rdx,%rsi\n" if ($narg>1);

		$func .= "	movq	%r8,%rdx\n"  if ($narg>2);

		$func .= "	movq	%r9,%rcx\n"  if ($narg>3);

		$func .= "	movq	40(%rsp),%r8\n" if ($narg>4);

		$func .= "	movq	48(%rsp),%r9\n" if ($narg>5);

	    }

	    $func;

	} elsif ($self->{value} ne "$current_function->{name}") {

	    # Make all labels in masm global.

	    $self->{value} .= ":" if ($masm);

	    $self->{value} . ":";

	} elsif ($win64 && $current_function->{abi} eq "svr4") {

	    my $func =	"$current_function->{name}" .

			($nasm ? ":" : "\tPROC $current_function->{scope}") .

			"\n";

	    $func .= "	mov	QWORD$PTR\[8+rsp\],rdi\t;WIN64 prologue\n";

	    $func .= "	mov	QWORD$PTR\[16+rsp\],rsi\n";

	    $func .= "	mov	rax,rsp\n";

	    $func .= "${decor}SEH_begin_$current_function->{name}:";

	    $func .= ":" if ($masm);

	    $func .= "\n";

	    my $narg = $current_function->{narg};

	    $narg=6 if (!defined($narg));

	    $func .= "	mov	rdi,rcx\n" if ($narg>0);

	    $func .= "	mov	rsi,rdx\n" if ($narg>1);

	    $func .= "	mov	rdx,r8\n"  if ($narg>2);

	    $func .= "	mov	rcx,r9\n"  if ($narg>3);

	    $func .= "	mov	r8,QWORD$PTR\[40+rsp\]\n" if ($narg>4);

	    $func .= "	mov	r9,QWORD$PTR\[48+rsp\]\n" if ($narg>5);

	    $func .= "\n";

	} else {

	   "$current_function->{name}".

			($nasm ? ":" : "\tPROC $current_function->{scope}");

	}

    }

}

{ package expr;		# pick up expressions

    sub re {

	my	($class, $line, $opcode) = @_;

	my	$self = {};

	my	$ret;

	if ($$line =~ /(^[^,]+)/) {

	    bless $self,$class;

	    $self->{value} = $1;

	    $ret = $self;

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	    $self->{value} =~ s/\@PLT// if (!$elf);

	    $self->{value} =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei;

	    $self->{value} =~ s/\.L/$decor/g;

	    $self->{opcode} = $opcode;

	}

	$ret;

    }

    sub out {

	my $self = shift;

	if ($nasm && $self->{opcode}->mnemonic()=~m/^j(?![re]cxz)/) {

	    "NEAR ".$self->{value};

	} else {

	    $self->{value};

	}

    }

}

{ package cfi_directive;

    # CFI directives annotate instructions that are significant for

    # stack unwinding procedure compliant with DWARF specification,

    # see http://dwarfstd.org/. Besides naturally expected for this

    # script platform-specific filtering function, this module adds

    # three auxiliary synthetic directives not recognized by [GNU]

    # assembler:

    #

    # - .cfi_push to annotate push instructions in prologue, which

    #   translates to .cfi_adjust_cfa_offset (if needed) and

    #   .cfi_offset;

    # - .cfi_pop to annotate pop instructions in epilogue, which

    #   translates to .cfi_adjust_cfa_offset (if needed) and

    #   .cfi_restore;

    # - [and most notably] .cfi_cfa_expression which encodes

    #   DW_CFA_def_cfa_expression and passes it to .cfi_escape as

    #   byte vector;

    #

    # CFA expressions were introduced in DWARF specification version

    # 3 and describe how to deduce CFA, Canonical Frame Address. This

    # becomes handy if your stack frame is variable and you can't

    # spare register for [previous] frame pointer. Suggested directive

    # syntax is made-up mix of DWARF operator suffixes [subset of]

    # and references to registers with optional bias. Following example

    # describes offloaded *original* stack pointer at specific offset

    # from *current* stack pointer:

    #

    #   .cfi_cfa_expression     %rsp+40,deref,+8

    #

    # Final +8 has everything to do with the fact that CFA is defined

    # as reference to top of caller's stack, and on x86_64 call to

    # subroutine pushes 8-byte return address. In other words original

    # stack pointer upon entry to a subroutine is 8 bytes off from CFA.

    # Below constants are taken from "DWARF Expressions" section of the

    # DWARF specification, section is numbered 7.7 in versions 3 and 4.

    my %DW_OP_simple = (	# no-arg operators, mapped directly

	deref	=> 0x06,	dup	=> 0x12,

	drop	=> 0x13,	over	=> 0x14,

	pick	=> 0x15,	swap	=> 0x16,

	rot	=> 0x17,	xderef	=> 0x18,

	abs	=> 0x19,	and	=> 0x1a,

	div	=> 0x1b,	minus	=> 0x1c,

	mod	=> 0x1d,	mul	=> 0x1e,

	neg	=> 0x1f,	not	=> 0x20,

	or	=> 0x21,	plus	=> 0x22,

	shl	=> 0x24,	shr	=> 0x25,

	shra	=> 0x26,	xor	=> 0x27,

	);

    my %DW_OP_complex = (	# used in specific subroutines

	constu		=> 0x10,	# uleb128

	consts		=> 0x11,	# sleb128

	plus_uconst	=> 0x23,	# uleb128

	lit0 		=> 0x30,	# add 0-31 to opcode

	reg0		=> 0x50,	# add 0-31 to opcode

	breg0		=> 0x70,	# add 0-31 to opcole, sleb128

	regx		=> 0x90,	# uleb28

	fbreg		=> 0x91,	# sleb128

	bregx		=> 0x92,	# uleb128, sleb128

	piece		=> 0x93,	# uleb128

	);

    # Following constants are defined in x86_64 ABI supplement, for

    # example available at https://www.uclibc.org/docs/psABI-x86_64.pdf,

    # see section 3.7 "Stack Unwind Algorithm".

    my %DW_reg_idx = (

	"%rax"=>0,  "%rdx"=>1,  "%rcx"=>2,  "%rbx"=>3,

	"%rsi"=>4,  "%rdi"=>5,  "%rbp"=>6,  "%rsp"=>7,

	"%r8" =>8,  "%r9" =>9,  "%r10"=>10, "%r11"=>11,

	"%r12"=>12, "%r13"=>13, "%r14"=>14, "%r15"=>15

	);

    my ($cfa_reg, $cfa_rsp);

    my @cfa_stack;

    # [us]leb128 format is variable-length integer representation base

    # 2^128, with most significant bit of each byte being 0 denoting

    # *last* most significant digit. See "Variable Length Data" in the

    # DWARF specification, numbered 7.6 at least in versions 3 and 4.

    sub sleb128 {

	use integer;	# get right shift extend sign

	my $val = shift;

	my $sign = ($val < 0) ? -1 : 0;

	my @ret = ();

	while(1) {

	    push @ret, $val&0x7f;

	    # see if remaining bits are same and equal to most

	    # significant bit of the current digit, if so, it's

	    # last digit...

	    last if (($val>>6) == $sign);

	    @ret[-1] |= 0x80;

	    $val >>= 7;

	}

	return @ret;

    }

    sub uleb128 {

	my $val = shift;

	my @ret = ();

	while(1) {

	    push @ret, $val&0x7f;

	    # see if it's last significant digit...

	    last if (($val >>= 7) == 0);

	    @ret[-1] |= 0x80;

	}

	return @ret;

    }

    sub const {

	my $val = shift;

	if ($val >= 0 && $val < 32) {

            return ($DW_OP_complex{lit0}+$val);

	}

	return ($DW_OP_complex{consts}, sleb128($val));

    }

    sub reg {

	my $val = shift;

	return if ($val !~ m/^(%r\w+)(?:([\+\-])((?:0x)?[0-9a-f]+))?/);

	my $reg = $DW_reg_idx{$1};

	my $off = eval ("0 $2 $3");

	return (($DW_OP_complex{breg0} + $reg), sleb128($off));

	# Yes, we use DW_OP_bregX+0 to push register value and not

	# DW_OP_regX, because latter would require even DW_OP_piece,

	# which would be a waste under the circumstances. If you have

	# to use DWP_OP_reg, use "regx:N"...

    }

    sub cfa_expression {

	my $line = shift;

	my @ret;

	foreach my $token (split(/,\s*/,$line)) {

	    if ($token =~ /^%r/) {

		push @ret,reg($token);

	    } elsif ($token =~ /((?:0x)?[0-9a-f]+)\((%r\w+)\)/) {

		push @ret,reg("$2+$1");

	    } elsif ($token =~ /(\w+):(\-?(?:0x)?[0-9a-f]+)(U?)/i) {

		my $i = 1*eval($2);

		push @ret,$DW_OP_complex{$1}, ($3 ? uleb128($i) : sleb128($i));

	    } elsif (my $i = 1*eval($token) or $token eq "0") {

		if ($token =~ /^\+/) {

		    push @ret,$DW_OP_complex{plus_uconst},uleb128($i);

		} else {

		    push @ret,const($i);

		}

	    } else {

		push @ret,$DW_OP_simple{$token};

	    }

	}

	# Finally we return DW_CFA_def_cfa_expression, 15, followed by

	# length of the expression and of course the expression itself.

	return (15,scalar(@ret),@ret);

    }

    sub re {

	my	($class, $line) = @_;

	my	$self = {};

	my	$ret;

	if ($$line =~ s/^\s*\.cfi_(\w+)\s*//) {

	    bless $self,$class;

	    $ret = $self;

	    undef $self->{value};

	    my $dir = $1;

	    SWITCH: for ($dir) {

	    # What is $cfa_rsp? Effectively it's difference between %rsp

	    # value and current CFA, Canonical Frame Address, which is

	    # why it starts with -8. Recall that CFA is top of caller's

	    # stack...

	    /startproc/	&& do {	($cfa_reg, $cfa_rsp) = ("%rsp", -8); last; };

	    /endproc/	&& do {	($cfa_reg, $cfa_rsp) = ("%rsp",  0);

				# .cfi_remember_state directives that are not

				# matched with .cfi_restore_state are

				# unnecessary.

				die "unpaired .cfi_remember_state" if (@cfa_stack);

				last;

			      };

	    /def_cfa_register/

			&& do {	$cfa_reg = $$line; last; };

	    /def_cfa_offset/

			&& do {	$cfa_rsp = -1*eval($$line) if ($cfa_reg eq "%rsp");

				last;

			      };

	    /adjust_cfa_offset/

			&& do {	$cfa_rsp -= 1*eval($$line) if ($cfa_reg eq "%rsp");

				last;

			      };

	    /def_cfa/	&& do {	if ($$line =~ /(%r\w+)\s*,\s*(.+)/) {

				    $cfa_reg = $1;

				    $cfa_rsp = -1*eval($2) if ($cfa_reg eq "%rsp");

				}

				last;

			      };

	    /push/	&& do {	$dir = undef;

				$cfa_rsp -= 8;

				if ($cfa_reg eq "%rsp") {

				    $self->{value} = ".cfi_adjust_cfa_offset\t8\n";

				}

				$self->{value} .= ".cfi_offset\t$$line,$cfa_rsp";

				last;

			      };

	    /pop/	&& do {	$dir = undef;

				$cfa_rsp += 8;

				if ($cfa_reg eq "%rsp") {

				    $self->{value} = ".cfi_adjust_cfa_offset\t-8\n";

				}

				$self->{value} .= ".cfi_restore\t$$line";

				last;

			      };

	    /cfa_expression/

			&& do {	$dir = undef;

				$self->{value} = ".cfi_escape\t" .

					join(",", map(sprintf("0x%02x", $_),

						      cfa_expression($$line)));

				last;

			      };

	    /remember_state/

			&& do {	push @cfa_stack, [$cfa_reg, $cfa_rsp];

				last;

			      };

	    /restore_state/

			&& do {	($cfa_reg, $cfa_rsp) = @{pop @cfa_stack};

				last;

			      };

	    }

	    $self->{value} = ".cfi_$dir\t$$line" if ($dir);

	    $$line = "";

	}

	return $ret;

    }

    sub out {

	my $self = shift;

	return ($elf ? $self->{value} : undef);

    }

}

{ package directive;	# pick up directives, which start with .

    sub re {

	my	($class, $line) = @_;

	my	$self = {};

	my	$ret;

	my	$dir;

	# chain-call to cfi_directive

	$ret = cfi_directive->re($line) and return $ret;

	if ($$line =~ /^\s*(\.\w+)/) {

	    bless $self,$class;

	    $dir = $1;

	    $ret = $self;

	    undef $self->{value};

	    $$line = substr($$line,@+[0]); $$line =~ s/^\s+//;

	    SWITCH: for ($dir) {

		/\.global|\.globl|\.extern/

			    && do { $globals{$$line} = $prefix . $$line;

				    $$line = $globals{$$line} if ($prefix);

				    last;

				  };

		/\.type/    && do { my ($sym,$type,$narg) = split(',',$$line);

				    if ($type eq "\@function") {

					undef $current_function;

					$current_function->{name} = $sym;

					$current_function->{abi}  = "svr4";

					$current_function->{narg} = $narg;

					$current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE";

				    } elsif ($type eq "\@abi-omnipotent") {

					undef $current_function;

					$current_function->{name} = $sym;

					$current_function->{scope} = defined($globals{$sym})?"PUBLIC":"PRIVATE";

				    }

				    $$line =~ s/\@abi\-omnipotent/\@function/;

				    $$line =~ s/\@function.*/\@function/;

				    last;

				  };

		/\.asciz/   && do { if ($$line =~ /^"(.*)"$/) {

					$dir  = ".byte";

					$$line = join(",",unpack("C*",$1),0);

				    }

				    last;

				  };

		/\.rva|\.long|\.quad/

			    && do { $$line =~ s/([_a-z][_a-z0-9]*)/$globals{$1} or $1/gei;

				    $$line =~ s/\.L/$decor/g;

				    last;

				  };

	    }

	    if ($gas) {

		$self->{value} = $dir . "\t" . $$line;

		if ($dir =~ /\.extern/) {

		    $self->{value} = ""; # swallow extern

		} elsif (!$elf && $dir =~ /\.type/) {

		    $self->{value} = "";

		    $self->{value} = ".def\t" . ($globals{$1} or $1) . ";\t" .

				(defined($globals{$1})?".scl 2;":".scl 3;") .

				"\t.type 32;\t.endef"

				if ($win64 && $$line =~ /([^,]+),\@function/);

		} elsif (!$elf && $dir =~ /\.size/) {

		    $self->{value} = "";

		    if (defined($current_function)) {

			$self->{value} .= "${decor}SEH_end_$current_function->{name}:"

				if ($win64 && $current_function->{abi} eq "svr4");

			undef $current_function;

		    }

		} elsif (!$elf && $dir =~ /\.align/) {

		    $self->{value} = ".p2align\t" . (log($$line)/log(2));

		} elsif ($dir eq ".section") {

		    $current_segment=$$line;

		    if (!$elf && $current_segment eq ".init") {

			if	($flavour eq "macosx")	{ $self->{value} = ".mod_init_func"; }

			elsif	($flavour eq "mingw64")	{ $self->{value} = ".section\t.ctors"; }

		    }

		} elsif ($dir =~ /\.(text|data)/) {

		    $current_segment=".$1";

		} elsif ($dir =~ /\.hidden/) {

		    if    ($flavour eq "macosx")  { $self->{value} = ".private_extern\t$prefix$$line"; }

		    elsif ($flavour eq "mingw64") { $self->{value} = ""; }

		} elsif ($dir =~ /\.comm/) {

		    $self->{value} = "$dir\t$prefix$$line";

		    $self->{value} =~ s|,([0-9]+),([0-9]+)$|",$1,".log($2)/log(2)|e if ($flavour eq "macosx");

		}

		$$line = "";

		return $self;

	    }

	    # non-gas case or nasm/masm

	    SWITCH: for ($dir) {

		/\.text/    && do { my $v=undef;

				    if ($nasm) {

					$v="section	.text code align=64\n";

				    } else {

					$v="$current_segment\tENDS\n" if ($current_segment);

					$current_segment = ".text\$";

					$v.="$current_segment\tSEGMENT ";

					$v.=$masm>=$masmref ? "ALIGN(256)" : "PAGE";

					$v.=" 'CODE'";

				    }

				    $self->{value} = $v;

				    last;

				  };

		/\.data/    && do { my $v=undef;

				    if ($nasm) {

					$v="section	.data data align=8\n";

				    } else {

					$v="$current_segment\tENDS\n" if ($current_segment);

					$current_segment = "_DATA";

					$v.="$current_segment\tSEGMENT";

				    }

				    $self->{value} = $v;

				    last;

				  };

		/\.section/ && do { my $v=undef;

				    $$line =~ s/([^,]*).*/$1/;

				    $$line = ".CRT\$XCU" if ($$line eq ".init");

				    if ($nasm) {

					$v="section	$$line";

					if ($$line=~/\.([px])data/) {

					    $v.=" rdata align=";

					    $v.=$1 eq "p"? 4 : 8;

					} elsif ($$line=~/\.CRT\$/i) {

					    $v.=" rdata align=8";

					}

				    } else {

					$v="$current_segment\tENDS\n" if ($current_segment);

					$v.="$$line\tSEGMENT";

					if ($$line=~/\.([px])data/) {

					    $v.=" READONLY";

					    $v.=" ALIGN(".($1 eq "p" ? 4 : 8).")" if ($masm>=$masmref);