3 # Ascetic x86_64 AT&T to MASM assembler translator by <appro>.
5 # Why AT&T to MASM and not vice versa? Several reasons. Because AT&T
6 # format is way easier to parse. Because it's simpler to "gear" from
7 # Unix ABI to Windows one [see cross-reference "card" at the end of
8 # file]. Because Linux targets were available first...
10 # In addition the script also "distills" code suitable for GNU
11 # assembler, so that it can be compiled with more rigid assemblers,
12 # such as Solaris /usr/ccs/bin/as.
14 # This translator is not designed to convert *arbitrary* assembler
15 # code from AT&T format to MASM one. It's designed to convert just
16 # enough to provide for dual-ABI OpenSSL modules development...
17 # There *are* limitations and you might have to modify your assembler
18 # code or this script to achieve the desired result...
20 # Currently recognized limitations:
22 # - can't use multiple ops per line;
23 # - indirect calls and jumps are not supported;
25 # Dual-ABI styling rules.
27 # 1. Adhere to Unix register and stack layout [see the end for
29 # 2. Forget about "red zone," stick to more traditional blended
30 # stack frame allocation. If volatile storage is actually required
31 # that is. If not, just leave the stack as is.
32 # 3. Functions tagged with ".type name,@function" get crafted with
33 # unified Win64 prologue and epilogue automatically. If you want
34 # to take care of ABI differences yourself, tag functions as
35 # ".type name,@abi-omnipotent" instead.
36 # 4. To optimize the Win64 prologue you can specify number of input
37 # arguments as ".type name,@function,N." Keep in mind that if N is
38 # larger than 6, then you *have to* write "abi-omnipotent" code,
39 # because >6 cases can't be addressed with unified prologue.
40 # 5. Name local labels as .L*, do *not* use dynamic labels such as 1:
41 # (sorry about latter).
42 # 6. Don't use [or hand-code with .byte] "rep ret." "ret" mnemonic is
43 # required to identify the spots, where to inject Win64 epilogue!
44 # But on the pros, it's then prefixed with rep automatically:-)
45 # 7. Due to MASM limitations [and certain general counter-intuitivity
46 # of ip-relative addressing] generation of position-independent
47 # code is assisted by synthetic directive, .picmeup, which puts
48 # address of the *next* instruction into target register.
52 # lea .Label-.(%rax),%rax
57 # lea .Label-.Lpic_point(%rcx),%rbp
61 { my ($stddev,$stdino,@junk)=stat(STDOUT);
62 my ($outdev,$outino,@junk)=stat($output);
64 open STDOUT,">$output" || die "can't open $output: $!"
65 if ($stddev!=$outdev || $stdino!=$outino);
68 my $win64=1 if ($output =~ /\.asm/);
70 my $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005
77 { if ($ENV{ASM} =~ m/nasm/)
78 { $nasm = 1; $PTR=""; }
79 elsif (`ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/)
80 { $masm = $1 + $2*2**-16 + $4*2**-32; }
86 { package opcode; # pick up opcodes
88 my $self = shift; # single instance in enough...
92 if ($line =~ /^([a-z][a-z0-9]*)/i) {
95 $line = substr($line,@+[0]); $line =~ s/^\s+//;
98 if ($self->{op} =~ /^(movz)b.*/) { # movz is pain...
101 } elsif ($self->{op} =~ /call/) {
103 } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) {
113 $self->{sz} = $sz if (defined($sz) && !defined($self->{sz}));
119 if ($self->{op} eq "movz") { # movz is pain...
120 sprintf "%s%s%s",$self->{op},$self->{sz},shift;
121 } elsif ($self->{op} =~ /^set/) {
123 } elsif ($self->{op} eq "ret") {
126 "$self->{op}$self->{sz}";
129 $self->{op} =~ s/^movz/movzx/;
130 if ($self->{op} eq "ret") {
132 if ($current_function->{abi} eq "svr4") {
133 $self->{op} = "mov rdi,QWORD${PTR}[8+rsp]\t;WIN64 epilogue\n\t".
134 "mov rsi,QWORD${PTR}[16+rsp]\n\t";
136 $self->{op} .= "DB\t0F3h,0C3h\t\t;repret";
137 } elsif ($self->{op} =~ /^j/ && $nasm) {
138 $self->{op} .= " NEAR";
143 sub mnemonic { shift->{op}; }
145 { package const; # pick up constants, which start with $
147 my $self = shift; # single instance in enough...
151 if ($line =~ /^\$([^,]+)/) {
154 $line = substr($line,@+[0]); $line =~ s/^\s+//;
162 # Solaris /usr/ccs/bin/as can't handle multiplications
164 $self->{value} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
165 $self->{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
166 sprintf "\$%s",$self->{value};
168 $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig;
169 sprintf "%s",$self->{value};
173 { package ea; # pick up effective addresses: expr(%reg,%reg,scale)
175 my $self = shift; # single instance in enough...
179 if ($line =~ /^([^\(,]*)\(([%\w,]+)\)/) {
181 ($self->{base},$self->{index},$self->{scale})=split(/,/,$2);
182 $self->{scale} = 1 if (!defined($self->{scale}));
184 $line = substr($line,@+[0]); $line =~ s/^\s+//;
186 $self->{base} =~ s/^%//;
187 $self->{index} =~ s/^%// if (defined($self->{index}));
196 # Silently convert all EAs to 64-bit. This is required for
197 # elder GNU assembler and results in more compact code,
198 # *but* most importantly AES module depends on this feature!
199 $self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;
200 $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;
203 # Solaris /usr/ccs/bin/as can't handle multiplications
205 $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
206 $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
208 if (defined($self->{index})) {
209 sprintf "%s(%%%s,%%%s,%d)",
210 $self->{label},$self->{base},
211 $self->{index},$self->{scale};
213 sprintf "%s(%%%s)", $self->{label},$self->{base};
216 %szmap = ( b=>"BYTE$PTR", w=>"WORD$PTR", l=>"DWORD$PTR", q=>"QWORD$PTR" );
218 $self->{label} =~ s/\./\$/g;
219 $self->{label} =~ s/0x([0-9a-f]+)/0$1h/ig;
220 $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/);
222 if (defined($self->{index})) {
223 sprintf "%s[%s%s*%d+%s]",$szmap{$sz},
224 $self->{label}?"$self->{label}+":"",
225 $self->{index},$self->{scale},
227 } elsif ($self->{base} eq "rip") {
228 sprintf "%s[%s]",$szmap{$sz},$self->{label};
230 sprintf "%s[%s%s]",$szmap{$sz},
231 $self->{label}?"$self->{label}+":"",
237 { package register; # pick up registers, which start with %.
239 my $class = shift; # muliple instances...
244 if ($line =~ /^%(\w+)/) {
248 $line = substr($line,@+[0]); $line =~ s/^\s+//;
256 if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; }
257 elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; }
258 elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; }
259 elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; }
260 elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; }
261 elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; }
262 elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; }
263 elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; }
269 sprintf $win64?"%s":"%%%s",$self->{value};
272 { package label; # pick up labels, which end with :
274 my $self = shift; # single instance is enough...
278 if ($line =~ /(^[\.\w]+\:)/) {
281 $line = substr($line,@+[0]); $line =~ s/^\s+//;
283 $self->{value} =~ s/\.L/\$L/ if ($win64);
292 } elsif ($self->{value} ne "$current_function->{name}:") {
294 } elsif ($current_function->{abi} eq "svr4") {
295 my $func = "$current_function->{name}".($nasm?":":"\tPROC")."\n".
296 " mov QWORD${PTR}[8+rsp],rdi\t;WIN64 prologue\n".
297 " mov QWORD${PTR}[16+rsp],rsi\n";
298 my $narg = $current_function->{narg};
299 $narg=6 if (!defined($narg));
300 $func .= " mov rdi,rcx\n" if ($narg>0);
301 $func .= " mov rsi,rdx\n" if ($narg>1);
302 $func .= " mov rdx,r8\n" if ($narg>2);
303 $func .= " mov rcx,r9\n" if ($narg>3);
304 $func .= " mov r8,QWORD${PTR}[40+rsp]\n" if ($narg>4);
305 $func .= " mov r9,QWORD${PTR}[48+rsp]\n" if ($narg>5);
308 "$current_function->{name}".($nasm?":":"\tPROC");
312 { package expr; # pick up expressioins
314 my $self = shift; # single instance is enough...
318 if ($line =~ /(^[^,]+)/) {
321 $line = substr($line,@+[0]); $line =~ s/^\s+//;
323 $self->{value} =~ s/\.L/\$L/g if ($win64);
332 { package directive; # pick up directives, which start with .
334 my $self = shift; # single instance is enough...
338 my %opcode = # lea 2f-1f(%rip),%dst; 1: nop; 2:
339 ( "%rax"=>0x01058d48, "%rcx"=>0x010d8d48,
340 "%rdx"=>0x01158d48, "%rbx"=>0x011d8d48,
341 "%rsp"=>0x01258d48, "%rbp"=>0x012d8d48,
342 "%rsi"=>0x01358d48, "%rdi"=>0x013d8d48,
343 "%r8" =>0x01058d4c, "%r9" =>0x010d8d4c,
344 "%r10"=>0x01158d4c, "%r11"=>0x011d8d4c,
345 "%r12"=>0x01258d4c, "%r13"=>0x012d8d4c,
346 "%r14"=>0x01358d4c, "%r15"=>0x013d8d4c );
348 if ($line =~ /^\s*(\.\w+)/) {
351 $line =~ s/\@abi\-omnipotent/\@function/;
352 $line =~ s/\@function.*/\@function/;
353 if ($line =~ /\.picmeup\s+(%r[\w]+)/i) {
354 $self->{value} = sprintf "\t.long\t0x%x,0x90000000",$opcode{$1};
355 } elsif ($line =~ /\.asciz\s+"(.*)"$/) {
356 $self->{value} = ".byte\t".join(",",unpack("C*",$1),0);
357 } elsif ($line =~ /\.extern/) {
358 $self->{value} = ""; # swallow extern
360 $self->{value} = $line;
368 undef $self->{value};
369 $line = substr($line,@+[0]); $line =~ s/^\s+//;
374 $v ="section .$1 code align=64\n";
376 $v.="%define PUBLIC global";
378 $v="$current_segment\tENDS\n" if ($current_segment);
379 $current_segment = "_$1\$";
380 $current_segment =~ tr/[a-z]/[A-Z]/;
381 $v.="$current_segment\tSEGMENT ";
382 $v.=$masm>=$masmref ? "ALIGN(64)" : "PAGE";
388 /\.extern/ && do { $self->{value} = "EXTERN\t".$line;
389 $self->{value} .= ":BYTE" if (!$nasm);
392 /\.globl/ && do { $self->{value} = "PUBLIC\t".$line; last; };
393 /\.type/ && do { ($sym,$type,$narg) = split(',',$line);
394 if ($type eq "\@function") {
395 undef $current_function;
396 $current_function->{name} = $sym;
397 $current_function->{abi} = "svr4";
398 $current_function->{narg} = $narg;
399 } elsif ($type eq "\@abi-omnipotent") {
400 undef $current_function;
401 $current_function->{name} = $sym;
405 /\.size/ && do { if (defined($current_function)) {
406 $self->{value}="$current_function->{name}\tENDP" if(!$nasm);
407 undef $current_function;
411 /\.align/ && do { $self->{value} = "ALIGN\t".$line; last; };
412 /\.(byte|value|long|quad)/
413 && do { my @arr = split(',',$line);
414 my $sz = substr($1,0,1);
415 my $last = pop(@arr);
416 my $conv = sub { my $var=shift;
417 if ($var=~s/0x([0-9a-f]+)/0$1h/i) { $var; }
418 else { sprintf"0%Xh",$var; }
421 $sz =~ tr/bvlq/BWDQ/;
422 $self->{value} = "\tD$sz\t";
423 for (@arr) { $self->{value} .= &$conv($_).","; }
424 $self->{value} .= &$conv($last);
427 /\.picmeup/ && do { $self->{value} = sprintf"\tDD\t0%Xh,090000000h",$opcode{$line};
430 /\.asciz/ && do { if ($line =~ /^"(.*)"$/) {
431 my @str=unpack("C*",$1);
434 $self->{value}.="DB\t"
435 .join(",",@str[0..15])."\n";
436 foreach (0..15) { shift @str; }
438 $self->{value}.="DB\t"
439 .join(",",@str) if (@str);
459 $line =~ s|[#!].*$||; # get rid of asm-style comments...
460 $line =~ s|/\*.*\*/||; # ... and C-style comments...
461 $line =~ s|^\s+||; # ... and skip white spaces in beginning
469 if ($label=label->re(\$line)) { print $label->out(); }
471 if (directive->re(\$line)) {
472 printf "%s",directive->out();
473 } elsif ($opcode=opcode->re(\$line)) { ARGUMENT: {
475 if ($src=register->re(\$line)) { opcode->size($src->size()); }
476 elsif ($src=const->re(\$line)) { }
477 elsif ($src=ea->re(\$line)) { }
478 elsif ($src=expr->re(\$line)) { }
480 last ARGUMENT if ($line !~ /^,/);
482 $line = substr($line,1); $line =~ s/^\s+//;
484 if ($dst=register->re(\$line)) { opcode->size($dst->size()); }
485 elsif ($dst=const->re(\$line)) { }
486 elsif ($dst=ea->re(\$line)) { }
494 printf "\t%s\t%s,%s", $opcode->out($dst->size()),
495 $src->out($sz),$dst->out($sz);
497 undef $sz if ($nasm && $opcode->mnemonic() eq "lea");
498 printf "\t%s\t%s,%s", $opcode->out(),
499 $dst->out($sz),$src->out($sz);
501 } elsif (defined($src)) {
502 printf "\t%s\t%s",$opcode->out(),$src->out($sz);
504 printf "\t%s",$opcode->out();
511 print "\n$current_segment\tENDS\nEND\n" if ($current_segment);
515 #################################################
516 # Cross-reference x86_64 ABI "card"
536 # (*) volatile register
537 # (-) preserved by callee
538 # (#) Nth argument, volatile
540 # In Unix terms top of stack is argument transfer area for arguments
541 # which could not be accomodated in registers. Or in other words 7th
542 # [integer] argument resides at 8(%rsp) upon function entry point.
543 # 128 bytes above %rsp constitute a "red zone" which is not touched
544 # by signal handlers and can be used as temporal storage without
545 # allocating a frame.
547 # In Win64 terms N*8 bytes on top of stack is argument transfer area,
548 # which belongs to/can be overwritten by callee. N is the number of
549 # arguments passed to callee, *but* not less than 4! This means that
550 # upon function entry point 5th argument resides at 40(%rsp), as well
551 # as that 32 bytes from 8(%rsp) can always be used as temporal
552 # storage [without allocating a frame]. One can actually argue that
553 # one can assume a "red zone" above stack pointer under Win64 as well.
554 # Point is that at apparently no occasion Windows kernel would alter
555 # the area above user stack pointer in true asynchronous manner...
557 # All the above means that if assembler programmer adheres to Unix
558 # register and stack layout, but disregards the "red zone" existense,
559 # it's possible to use following prologue and epilogue to "gear" from
560 # Unix to Win64 ABI in leaf functions with not more than 6 arguments.
562 # omnipotent_function:
566 # movq %rcx,%rdi ; if 1st argument is actually present
567 # movq %rdx,%rsi ; if 2nd argument is actually ...
568 # movq %r8,%rdx ; if 3rd argument is ...
569 # movq %r9,%rcx ; if 4th argument ...
570 # movq 40(%rsp),%r8 ; if 5th ...
571 # movq 48(%rsp),%r9 ; if 6th ...