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 $masmref=8 + 50727*2**-32; # 8.00.50727 shipped with VS2005
69 my $masm=$masmref if ($output =~ /\.asm/);
70 if ($masm && `ml64 2>&1` =~ m/Version ([0-9]+)\.([0-9]+)(\.([0-9]+))?/)
71 { $masm=$1 + $2*2**-16 + $4*2**-32; }
76 { package opcode; # pick up opcodes
78 my $self = shift; # single instance in enough...
82 if ($line =~ /^([a-z][a-z0-9]*)/i) {
85 $line = substr($line,@+[0]); $line =~ s/^\s+//;
88 if ($self->{op} =~ /^(movz)b.*/) { # movz is pain...
91 } elsif ($self->{op} =~ /call/) {
93 } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])$/) {
103 $self->{sz} = $sz if (defined($sz) && !defined($self->{sz}));
109 if ($self->{op} eq "movz") { # movz is pain...
110 sprintf "%s%s%s",$self->{op},$self->{sz},shift;
111 } elsif ($self->{op} =~ /^set/) {
113 } elsif ($self->{op} eq "ret") {
116 "$self->{op}$self->{sz}";
119 $self->{op} =~ s/^movz/movzx/;
120 if ($self->{op} eq "ret") {
122 if ($current_function->{abi} eq "svr4") {
123 $self->{op} = "mov rdi,QWORD PTR 8[rsp]\t;WIN64 epilogue\n\t".
124 "mov rsi,QWORD PTR 16[rsp]\n\t";
126 $self->{op} .= "DB\t0F3h,0C3h\t\t;repret";
132 { package const; # pick up constants, which start with $
134 my $self = shift; # single instance in enough...
138 if ($line =~ /^\$([^,]+)/) {
141 $line = substr($line,@+[0]); $line =~ s/^\s+//;
149 # Solaris /usr/ccs/bin/as can't handle multiplications
151 $self->{value} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
152 $self->{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
153 sprintf "\$%s",$self->{value};
155 $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig;
156 sprintf "%s",$self->{value};
160 { package ea; # pick up effective addresses: expr(%reg,%reg,scale)
162 my $self = shift; # single instance in enough...
166 if ($line =~ /^([^\(,]*)\(([%\w,]+)\)/) {
168 ($self->{base},$self->{index},$self->{scale})=split(/,/,$2);
169 $self->{scale} = 1 if (!defined($self->{scale}));
171 $line = substr($line,@+[0]); $line =~ s/^\s+//;
173 $self->{base} =~ s/^%//;
174 $self->{index} =~ s/^%// if (defined($self->{index}));
183 # Silently convert all EAs to 64-bit. This is required for
184 # elder GNU assembler and results in more compact code,
185 # *but* most importantly AES module depends on this feature!
186 $self->{index} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;
187 $self->{base} =~ s/^[er](.?[0-9xpi])[d]?$/r\1/;
190 # Solaris /usr/ccs/bin/as can't handle multiplications
192 $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
193 $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
195 if (defined($self->{index})) {
196 sprintf "%s(%%%s,%%%s,%d)",
197 $self->{label},$self->{base},
198 $self->{index},$self->{scale};
200 sprintf "%s(%%%s)", $self->{label},$self->{base};
203 %szmap = ( b=>"BYTE", w=>"WORD", l=>"DWORD", q=>"QWORD" );
205 $self->{label} =~ s/\./\$/g;
206 $self->{label} =~ s/0x([0-9a-f]+)/0$1h/ig;
207 $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/);
209 if (defined($self->{index})) {
210 sprintf "%s PTR %s[%s*%d+%s]",$szmap{$sz},
212 $self->{index},$self->{scale},
214 } elsif ($self->{base} eq "rip") {
215 sprintf "%s PTR %s",$szmap{$sz},$self->{label};
217 sprintf "%s PTR %s[%s]",$szmap{$sz},
218 $self->{label},$self->{base};
223 { package register; # pick up registers, which start with %.
225 my $class = shift; # muliple instances...
230 if ($line =~ /^%(\w+)/) {
234 $line = substr($line,@+[0]); $line =~ s/^\s+//;
242 if ($self->{value} =~ /^r[\d]+b$/i) { $ret="b"; }
243 elsif ($self->{value} =~ /^r[\d]+w$/i) { $ret="w"; }
244 elsif ($self->{value} =~ /^r[\d]+d$/i) { $ret="l"; }
245 elsif ($self->{value} =~ /^r[\w]+$/i) { $ret="q"; }
246 elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; }
247 elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; }
248 elsif ($self->{value} =~ /^[\w]{2}$/i) { $ret="w"; }
249 elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; }
255 sprintf $masm?"%s":"%%%s",$self->{value};
258 { package label; # pick up labels, which end with :
260 my $self = shift; # single instance is enough...
264 if ($line =~ /(^[\.\w]+\:)/) {
267 $line = substr($line,@+[0]); $line =~ s/^\s+//;
269 $self->{value} =~ s/\.L/\$L/ if ($masm);
278 } elsif ($self->{value} ne "$current_function->{name}:") {
280 } elsif ($current_function->{abi} eq "svr4") {
281 my $func = "$current_function->{name} PROC\n".
282 " mov QWORD PTR 8[rsp],rdi\t;WIN64 prologue\n".
283 " mov QWORD PTR 16[rsp],rsi\n";
284 my $narg = $current_function->{narg};
285 $narg=6 if (!defined($narg));
286 $func .= " mov rdi,rcx\n" if ($narg>0);
287 $func .= " mov rsi,rdx\n" if ($narg>1);
288 $func .= " mov rdx,r8\n" if ($narg>2);
289 $func .= " mov rcx,r9\n" if ($narg>3);
290 $func .= " mov r8,QWORD PTR 40[rsp]\n" if ($narg>4);
291 $func .= " mov r9,QWORD PTR 48[rsp]\n" if ($narg>5);
294 "$current_function->{name} PROC";
298 { package expr; # pick up expressioins
300 my $self = shift; # single instance is enough...
304 if ($line =~ /(^[^,]+)/) {
307 $line = substr($line,@+[0]); $line =~ s/^\s+//;
309 $self->{value} =~ s/\.L/\$L/g if ($masm);
318 { package directive; # pick up directives, which start with .
320 my $self = shift; # single instance is enough...
324 my %opcode = # lea 2f-1f(%rip),%dst; 1: nop; 2:
325 ( "%rax"=>0x01058d48, "%rcx"=>0x010d8d48,
326 "%rdx"=>0x01158d48, "%rbx"=>0x011d8d48,
327 "%rsp"=>0x01258d48, "%rbp"=>0x012d8d48,
328 "%rsi"=>0x01358d48, "%rdi"=>0x013d8d48,
329 "%r8" =>0x01058d4c, "%r9" =>0x010d8d4c,
330 "%r10"=>0x01158d4c, "%r11"=>0x011d8d4c,
331 "%r12"=>0x01258d4c, "%r13"=>0x012d8d4c,
332 "%r14"=>0x01358d4c, "%r15"=>0x013d8d4c );
334 if ($line =~ /^\s*(\.\w+)/) {
337 $line =~ s/\@abi\-omnipotent/\@function/;
338 $line =~ s/\@function.*/\@function/;
339 if ($line =~ /\.picmeup\s+(%r[\w]+)/i) {
340 $self->{value} = sprintf "\t.long\t0x%x,0x90000000",$opcode{$1};
341 } elsif ($line =~ /\.asciz\s+"(.*)"$/) {
342 $self->{value} = ".byte\t".join(",",unpack("C*",$1),0);
343 } elsif ($line =~ /\.extern/) {
344 $self->{value} = ""; # swallow extern
346 $self->{value} = $line;
354 undef $self->{value};
355 $line = substr($line,@+[0]); $line =~ s/^\s+//;
359 $v="$current_segment\tENDS\n" if ($current_segment);
360 $current_segment = "_$1\$";
361 $current_segment =~ tr/[a-z]/[A-Z]/;
362 $v.="$current_segment\tSEGMENT ";
363 $v.=$masm>=$masmref ? "ALIGN(64)" : "PAGE";
368 /\.extern/ && do { $self->{value} = "EXTRN\t".$line.":BYTE"; last; };
369 /\.globl/ && do { $self->{value} = "PUBLIC\t".$line; last; };
370 /\.type/ && do { ($sym,$type,$narg) = split(',',$line);
371 if ($type eq "\@function") {
372 undef $current_function;
373 $current_function->{name} = $sym;
374 $current_function->{abi} = "svr4";
375 $current_function->{narg} = $narg;
376 } elsif ($type eq "\@abi-omnipotent") {
377 undef $current_function;
378 $current_function->{name} = $sym;
382 /\.size/ && do { if (defined($current_function)) {
383 $self->{value}="$current_function->{name}\tENDP";
384 undef $current_function;
388 /\.align/ && do { $self->{value} = "ALIGN\t".$line; last; };
389 /\.(byte|value|long|quad)/
390 && do { my @arr = split(',',$line);
391 my $sz = substr($1,0,1);
392 my $last = pop(@arr);
393 my $conv = sub { my $var=shift;
394 if ($var=~s/0x([0-9a-f]+)/0$1h/i) { $var; }
395 else { sprintf"0%Xh",$var; }
398 $sz =~ tr/bvlq/BWDQ/;
399 $self->{value} = "\tD$sz\t";
400 for (@arr) { $self->{value} .= &$conv($_).","; }
401 $self->{value} .= &$conv($last);
404 /\.picmeup/ && do { $self->{value} = sprintf"\tDD\t 0%Xh,090000000h",$opcode{$line};
407 /\.asciz/ && do { if ($line =~ /^"(.*)"$/) {
408 my @str=unpack("C*",$1);
411 $self->{value}.="DB\t"
412 .join(",",@str[0..15])."\n";
413 foreach (0..15) { shift @str; }
415 $self->{value}.="DB\t"
416 .join(",",@str) if (@str);
436 $line =~ s|[#!].*$||; # get rid of asm-style comments...
437 $line =~ s|/\*.*\*/||; # ... and C-style comments...
438 $line =~ s|^\s+||; # ... and skip white spaces in beginning
446 if ($label=label->re(\$line)) { print $label->out(); }
448 if (directive->re(\$line)) {
449 printf "%s",directive->out();
450 } elsif ($opcode=opcode->re(\$line)) { ARGUMENT: {
452 if ($src=register->re(\$line)) { opcode->size($src->size()); }
453 elsif ($src=const->re(\$line)) { }
454 elsif ($src=ea->re(\$line)) { }
455 elsif ($src=expr->re(\$line)) { }
457 last ARGUMENT if ($line !~ /^,/);
459 $line = substr($line,1); $line =~ s/^\s+//;
461 if ($dst=register->re(\$line)) { opcode->size($dst->size()); }
462 elsif ($dst=const->re(\$line)) { }
463 elsif ($dst=ea->re(\$line)) { }
471 printf "\t%s\t%s,%s", $opcode->out($dst->size()),
472 $src->out($sz),$dst->out($sz);
474 printf "\t%s\t%s,%s", $opcode->out(),
475 $dst->out($sz),$src->out($sz);
477 } elsif (defined($src)) {
478 printf "\t%s\t%s",$opcode->out(),$src->out($sz);
480 printf "\t%s",$opcode->out();
487 print "\n$current_segment\tENDS\nEND\n" if ($masm);
491 #################################################
492 # Cross-reference x86_64 ABI "card"
512 # (*) volatile register
513 # (-) preserved by callee
514 # (#) Nth argument, volatile
516 # In Unix terms top of stack is argument transfer area for arguments
517 # which could not be accomodated in registers. Or in other words 7th
518 # [integer] argument resides at 8(%rsp) upon function entry point.
519 # 128 bytes above %rsp constitute a "red zone" which is not touched
520 # by signal handlers and can be used as temporal storage without
521 # allocating a frame.
523 # In Win64 terms N*8 bytes on top of stack is argument transfer area,
524 # which belongs to/can be overwritten by callee. N is the number of
525 # arguments passed to callee, *but* not less than 4! This means that
526 # upon function entry point 5th argument resides at 40(%rsp), as well
527 # as that 32 bytes from 8(%rsp) can always be used as temporal
528 # storage [without allocating a frame]. One can actually argue that
529 # one can assume a "red zone" above stack pointer under Win64 as well.
530 # Point is that at apparently no occasion Windows kernel would alter
531 # the area above user stack pointer in true asynchronous manner...
533 # All the above means that if assembler programmer adheres to Unix
534 # register and stack layout, but disregards the "red zone" existense,
535 # it's possible to use following prologue and epilogue to "gear" from
536 # Unix to Win64 ABI in leaf functions with not more than 6 arguments.
538 # omnipotent_function:
542 # movq %rcx,%rdi ; if 1st argument is actually present
543 # movq %rdx,%rsi ; if 2nd argument is actually ...
544 # movq %r8,%rdx ; if 3rd argument is ...
545 # movq %r9,%rcx ; if 4th argument ...
546 # movq 40(%rsp),%r8 ; if 5th ...
547 # movq 48(%rsp),%r9 ; if 6th ...