crypto/perlasm/x86_64-xlate.pl

   1 #!/usr/bin/env perl
   2
   3 # Ascetic x86_64 AT&T to MASM assembler translator by <appro>.
   4 #
   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...
   9 #
  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.
  13 #
  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...
  19 #
  20 # Currently recognized limitations:
  21 #
  22 # - can't use multiple ops per line;
  23 # - indirect calls and jumps are not supported;
  24 #
  25 # Dual-ABI styling rules.
  26 #
  27 # 1. Adhere to Unix register and stack layout [see the end for
  28 #    explanation].
  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.
  49 #
  50 #    Example 1:
  51 #               .picmeup        %rax
  52 #               lea             .Label-.(%rax),%rax
  53 #    Example 2:
  54 #               .picmeup        %rcx
  55 #       .Lpic_point:
  56 #               ...
  57 #               lea             .Label-.Lpic_point(%rcx),%rbp
  58
  59 my $output = shift;
  60 open STDOUT,">$output" || die "can't open $output: $!";
  61
  62 my $masm=1 if ($output =~ /\.asm/);
  63
  64 my $current_segment;
  65 my $current_function;
  66
  67 { package opcode;       # pick up opcodes
  68     sub re {
  69         my      $self = shift;  # single instance in enough...
  70         local   *line = shift;
  71         undef   $ret;
  72
  73         if ($line =~ /^([a-z]+)/i) {
  74             $self->{op} = $1;
  75             $ret = $self;
  76             $line = substr($line,@+[0]); $line =~ s/^\s+//;
  77
  78             undef $self->{sz};
  79             if ($self->{op} =~ /(movz)b.*/) {   # movz is pain...
  80                 $self->{op} = $1;
  81                 $self->{sz} = "b";
  82             } elsif ($self->{op} =~ /([a-z]{3,})([qlwb])/) {
  83                 $self->{op} = $1;
  84                 $self->{sz} = $2;
  85             }
  86         }
  87         $ret;
  88     }
  89     sub size {
  90         my $self = shift;
  91         my $sz   = shift;
  92         $self->{sz} = $sz if (defined($sz) && !defined($self->{sz}));
  93         $self->{sz};
  94     }
  95     sub out {
  96         my $self = shift;
  97         if (!$masm) {
  98             if ($self->{op} eq "movz") {        # movz in pain...
  99                 sprintf "%s%s%s",$self->{op},$self->{sz},shift;
 100             } elsif ($self->{op} eq "ret") {
 101                 ".byte  0xf3,0xc3";
 102             } else {
 103                 "$self->{op}$self->{sz}";
 104             }
 105         } else {
 106             $self->{op} =~ s/movz/movzx/;
 107             if ($self->{op} eq "ret") {
 108                 $self->{op} = "";
 109                 if ($current_function->{abi} eq "svr4") {
 110                     $self->{op} = "mov  rdi,QWORD PTR 8[rsp]\t;WIN64 epilogue\n\t".
 111                                   "mov  rsi,QWORD PTR 16[rsp]\n\t";
 112                 }
 113                 $self->{op} .= "DB\t0F3h,0C3h\t\t;repret";
 114             }
 115             $self->{op};
 116         }
 117     }
 118 }
 119 { package const;        # pick up constants, which start with $
 120     sub re {
 121         my      $self = shift;  # single instance in enough...
 122         local   *line = shift;
 123         undef   $ret;
 124
 125         if ($line =~ /^\$([^,]+)/) {
 126             $self->{value} = $1;
 127             $ret = $self;
 128             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 129         }
 130         $ret;
 131     }
 132     sub out {
 133         my $self = shift;
 134
 135         if (!$masm) {
 136             # Solaris /usr/ccs/bin/as can't handle multiplications
 137             # in $self->{value}
 138             $self->{value} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
 139             $self->{value} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
 140             sprintf "\$%s",$self->{value};
 141         } else {
 142             $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig;
 143             sprintf "%s",$self->{value};
 144         }
 145     }
 146 }
 147 { package ea;           # pick up effective addresses: expr(%reg,%reg,scale)
 148     sub re {
 149         my      $self = shift;  # single instance in enough...
 150         local   *line = shift;
 151         undef   $ret;
 152
 153         if ($line =~ /^([^\(,]*)\(([%\w,]+)\)/) {
 154             $self->{label} = $1;
 155             ($self->{base},$self->{index},$self->{scale})=split(/,/,$2);
 156             $self->{scale} = 1 if (!defined($self->{scale}));
 157             $ret = $self;
 158             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 159
 160             $self->{base}  =~ s/^%//;
 161             $self->{index} =~ s/^%// if (defined($self->{index}));
 162         }
 163         $ret;
 164     }
 165     sub size {}
 166     sub out {
 167         my $self = shift;
 168         my $sz = shift;
 169
 170         # silently convert all EAs to 64-bit, required for elder GNU
 171         # assembler and results in more compact code
 172         $self->{index} =~ s/^[er](.?[0-9xp])[d]?$/r\1/;
 173         $self->{base}  =~ s/^[er](.?[0-9xp])[d]?$/r\1/;
 174         if (!$masm) {
 175             # Solaris /usr/ccs/bin/as can't handle multiplications
 176             # in $self->{label}
 177             $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
 178             $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
 179
 180             if (defined($self->{index})) {
 181                 sprintf "%s(%%%s,%%%s,%d)",
 182                                         $self->{label},$self->{base},
 183                                         $self->{index},$self->{scale};
 184             } else {
 185                 sprintf "%s(%%%s)",     $self->{label},$self->{base};
 186             }
 187         } else {
 188             %szmap = ( b=>"BYTE", w=>"WORD", l=>"DWORD", q=>"QWORD" );
 189
 190             $self->{label} =~ s/\./\$/g;
 191             $self->{label} =~ s/0x([0-9a-f]+)/0$1h/ig;
 192             $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/);
 193
 194             if (defined($self->{index})) {
 195                 sprintf "%s PTR %s[%s*%d+%s]",$szmap{$sz},
 196                                         $self->{label},
 197                                         $self->{index},$self->{scale},
 198                                         $self->{base};
 199             } else {
 200                 sprintf "%s PTR %s[%s]",$szmap{$sz},
 201                                         $self->{label},$self->{base};
 202             }
 203         }
 204     }
 205 }
 206 { package register;     # pick up registers, which start with %.
 207     sub re {
 208         my      $class = shift; # muliple instances...
 209         my      $self = {};
 210         local   *line = shift;
 211         undef   $ret;
 212
 213         if ($line =~ /^%(\w+)/) {
 214             bless $self,$class;
 215             $self->{value} = $1;
 216             $ret = $self;
 217             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 218         }
 219         $ret;
 220     }
 221     sub size {
 222         my      $self = shift;
 223         undef   $ret;
 224
 225         if    ($self->{value} =~ /^r[\d]+b$/i)  { $ret="b"; }
 226         elsif ($self->{value} =~ /^r[\d]+w$/i)  { $ret="w"; }
 227         elsif ($self->{value} =~ /^r[\d]+d$/i)  { $ret="l"; }
 228         elsif ($self->{value} =~ /^r[\w]+$/i)   { $ret="q"; }
 229         elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; }
 230         elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; }
 231         elsif ($self->{value} =~ /^[\w]{2}$/i)  { $ret="w"; }
 232         elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; }
 233
 234         $ret;
 235     }
 236     sub out {
 237         my $self = shift;
 238         sprintf $masm?"%s":"%%%s",$self->{value};
 239     }
 240 }
 241 { package label;        # pick up labels, which end with :
 242     sub re {
 243         my      $self = shift;  # single instance is enough...
 244         local   *line = shift;
 245         undef   $ret;
 246
 247         if ($line =~ /(^[\.\w]+\:)/) {
 248             $self->{value} = $1;
 249             $ret = $self;
 250             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 251
 252             $self->{value} =~ s/\.L/\$L/ if ($masm);
 253         }
 254         $ret;
 255     }
 256     sub out {
 257         my $self = shift;
 258
 259         if (!$masm) {
 260             $self->{value};
 261         } elsif ($self->{value} ne "$current_function->{name}:") {
 262             $self->{value};
 263         } elsif ($current_function->{abi} eq "svr4") {
 264             my $func =  "$current_function->{name}      PROC\n".
 265                         "       mov     QWORD PTR 8[rsp],rdi\t;WIN64 prologue\n".
 266                         "       mov     QWORD PTR 16[rsp],rsi\n";
 267             my $narg = $current_function->{narg};
 268             $narg=6 if (!defined($narg));
 269             $func .= "  mov     rdi,rcx\n" if ($narg>0);
 270             $func .= "  mov     rsi,rdx\n" if ($narg>1);
 271             $func .= "  mov     rdx,r8\n"  if ($narg>2);
 272             $func .= "  mov     rcx,r9\n"  if ($narg>3);
 273             $func .= "  mov     r8,QWORD PTR 40[rsp]\n" if ($narg>4);
 274             $func .= "  mov     r9,QWORD PTR 48[rsp]\n" if ($narg>5);
 275             $func .= "\n";
 276         } else {
 277            "$current_function->{name}   PROC";
 278         }
 279     }
 280 }
 281 { package expr;         # pick up expressioins
 282     sub re {
 283         my      $self = shift;  # single instance is enough...
 284         local   *line = shift;
 285         undef   $ret;
 286
 287         if ($line =~ /(^[^,]+)/) {
 288             $self->{value} = $1;
 289             $ret = $self;
 290             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 291
 292             $self->{value} =~ s/\.L/\$L/g if ($masm);
 293         }
 294         $ret;
 295     }
 296     sub out {
 297         my $self = shift;
 298         $self->{value};
 299     }
 300 }
 301 { package directive;    # pick up directives, which start with .
 302     sub re {
 303         my      $self = shift;  # single instance is enough...
 304         local   *line = shift;
 305         undef   $ret;
 306         my      $dir;
 307         my      %opcode =       # lea 2f-1f(%rip),%dst; 1: nop; 2:
 308                 (       "%rax"=>0x01058d48,     "%rcx"=>0x010d8d48,
 309                         "%rdx"=>0x01158d48,     "%rbx"=>0x011d8d48,
 310                         "%rsp"=>0x01258d48,     "%rbp"=>0x012d8d48,
 311                         "%rsi"=>0x01358d48,     "%rdi"=>0x013d8d48,
 312                         "%r8" =>0x01058d4c,     "%r9" =>0x010d8d4c,
 313                         "%r10"=>0x01158d4c,     "%r11"=>0x011d8d4c,
 314                         "%r12"=>0x01258d4c,     "%r13"=>0x012d8d4c,
 315                         "%r14"=>0x01358d4c,     "%r15"=>0x013d8d4c      );
 316
 317         if ($line =~ /^\s*(\.\w+)/) {
 318             if (!$masm) {
 319                 $self->{value} = $1;
 320                 $line =~ s/\@abi\-omnipotent/\@function/;
 321                 $line =~ s/\@function.*/\@function/;
 322                 if ($line =~ /\.picmeup\s+(%r[\w]+)/i) {
 323                     $self->{value} = sprintf "\t.long\t0x%x,0x90000000",$opcode{$1};
 324                 } else {
 325                     $self->{value} = $line;
 326                 }
 327                 $line = "";
 328                 return $self;
 329             }
 330
 331             $dir = $1;
 332             $ret = $self;
 333             undef $self->{value};
 334             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 335             SWITCH: for ($dir) {
 336                 /\.(text)/
 337                             && do { my $v=undef;
 338                                     $v="$current_segment\tENDS\n" if ($current_segment);
 339                                     $current_segment = "_$1\$";
 340                                     $current_segment =~ tr/[a-z]/[A-Z]/;
 341                                     $v.="$current_segment\tSEGMENT ALIGN(64) 'CODE'";
 342                                     $self->{value} = $v;
 343                                     last;
 344                                   };
 345                 /\.globl/   && do { $self->{value} = "PUBLIC\t".$line; last; };
 346                 /\.type/    && do { ($sym,$type,$narg) = split(',',$line);
 347                                     if ($type eq "\@function") {
 348                                         undef $current_function;
 349                                         $current_function->{name} = $sym;
 350                                         $current_function->{abi}  = "svr4";
 351                                         $current_function->{narg} = $narg;
 352                                     } elsif ($type eq "\@abi-omnipotent") {
 353                                         undef $current_function;
 354                                         $current_function->{name} = $sym;
 355                                     }
 356                                     last;
 357                                   };
 358                 /\.size/    && do { if (defined($current_function)) {
 359                                         $self->{value}="$current_function->{name}\tENDP";
 360                                         undef $current_function;
 361                                     }
 362                                     last;
 363                                   };
 364                 /\.align/   && do { $self->{value} = "ALIGN\t".$line; last; };
 365                 /\.(byte|value|long|quad)/
 366                             && do { my @arr = split(',',$line);
 367                                     my $sz  = substr($1,0,1);
 368                                     my $last = pop(@arr);
 369
 370                                     $sz =~ tr/bvlq/BWDQ/;
 371                                     $self->{value} = "\tD$sz\t";
 372                                     for (@arr) { $self->{value} .= sprintf"0%Xh,",oct; }
 373                                     $self->{value} .= sprintf"0%Xh",oct($last);
 374                                     last;
 375                                   };
 376                 /\.picmeup/ && do { $self->{value} = sprintf"\tDD\t 0%Xh,090000000h",$opcode{$line};
 377                                     last;
 378                                   };
 379             }
 380             $line = "";
 381         }
 382
 383         $ret;
 384     }
 385     sub out {
 386         my $self = shift;
 387         $self->{value};
 388     }
 389 }
 390
 391 while($line=<>) {
 392
 393     chomp($line);
 394
 395     $line =~ s|[#!].*$||;       # get rid of asm-style comments...
 396     $line =~ s|/\*.*\*/||;      # ... and C-style comments...
 397     $line =~ s|^\s+||;          # ... and skip white spaces in beginning
 398
 399     undef $label;
 400     undef $opcode;
 401     undef $dst;
 402     undef $src;
 403     undef $sz;
 404
 405     if ($label=label->re(\$line))       { print $label->out(); }
 406
 407     if (directive->re(\$line)) {
 408         printf "%s",directive->out();
 409     } elsif ($opcode=opcode->re(\$line)) { ARGUMENT: {
 410
 411         if ($src=register->re(\$line))  { opcode->size($src->size()); }
 412         elsif ($src=const->re(\$line))  { }
 413         elsif ($src=ea->re(\$line))     { }
 414         elsif ($src=expr->re(\$line))   { }
 415
 416         last ARGUMENT if ($line !~ /^,/);
 417
 418         $line = substr($line,1); $line =~ s/^\s+//;
 419
 420         if ($dst=register->re(\$line))  { opcode->size($dst->size()); }
 421         elsif ($dst=const->re(\$line))  { }
 422         elsif ($dst=ea->re(\$line))     { }
 423
 424         } # ARGUMENT:
 425
 426         $sz=opcode->size();
 427
 428         if (defined($dst)) {
 429             if (!$masm) {
 430                 printf "\t%s\t%s,%s",   $opcode->out($dst->size()),
 431                                         $src->out($sz),$dst->out($sz);
 432             } else {
 433                 printf "\t%s\t%s,%s",   $opcode->out(),
 434                                         $dst->out($sz),$src->out($sz);
 435             }
 436         } elsif (defined($src)) {
 437             printf "\t%s\t%s",$opcode->out(),$src->out($sz);
 438         } else {
 439             printf "\t%s",$opcode->out();
 440         }
 441     }
 442
 443     print $line,"\n";
 444 }
 445
 446 print "\n$current_segment\tENDS\nEND\n" if ($masm);
 447
 448 close STDOUT;
 449
 450 #################################################
 451 # Cross-reference x86_64 ABI "card"
 452 #
 453 #               Unix            Win64
 454 # %rax          *               *
 455 # %rbx          -               -
 456 # %rcx          #4              #1
 457 # %rdx          #3              #2
 458 # %rsi          #2              -
 459 # %rdi          #1              -
 460 # %rbp          -               -
 461 # %rsp          -               -
 462 # %r8           #5              #3
 463 # %r9           #6              #4
 464 # %r10          *               *
 465 # %r11          *               *
 466 # %r12          -               -
 467 # %r13          -               -
 468 # %r14          -               -
 469 # %r15          -               -
 470 #
 471 # (*)   volatile register
 472 # (-)   preserved by callee
 473 # (#)   Nth argument, volatile
 474 #
 475 # In Unix terms top of stack is argument transfer area for arguments
 476 # which could not be accomodated in registers. Or in other words 7th
 477 # [integer] argument resides at 8(%rsp) upon function entry point.
 478 # 128 bytes above %rsp constitute a "red zone" which is not touched
 479 # by signal handlers and can be used as temporal storage without
 480 # allocating a frame.
 481 #
 482 # In Win64 terms N*8 bytes on top of stack is argument transfer area,
 483 # which belongs to/can be overwritten by callee. N is the number of
 484 # arguments passed to callee, *but* not less than 4! This means that
 485 # upon function entry point 5th argument resides at 40(%rsp), as well
 486 # as that 32 bytes from 8(%rsp) can always be used as temporal
 487 # storage [without allocating a frame].
 488 #
 489 # All the above means that if assembler programmer adheres to Unix
 490 # register and stack layout, but disregards the "red zone" existense,
 491 # it's possible to use following prologue and epilogue to "gear" from
 492 # Unix to Win64 ABI in leaf functions with not more than 6 arguments.
 493 #
 494 # omnipotent_function:
 495 # ifdef WIN64
 496 #       movq    %rdi,8(%rsp)
 497 #       movq    %rsi,16(%rsp)
 498 #       movq    %rcx,%rdi       ; if 1st argument is actually present
 499 #       movq    %rdx,%rsi       ; if 2nd argument is actually ...
 500 #       movq    %r8,%rdx        ; if 3rd argument is ...
 501 #       movq    %r9,%rcx        ; if 4th argument ...
 502 #       movq    40(%rsp),%r8    ; if 5th ...
 503 #       movq    48(%rsp),%r9    ; if 6th ...
 504 # endif
 505 #       ...
 506 # ifdef WIN64
 507 #       movq    8(%rsp),%rdi
 508 #       movq    16(%rsp),%rsi
 509 # endif
 510 #       ret