crypto/openssl-0.9/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             sprintf "\$%s",$self->{value};
 137         } else {
 138             $self->{value} =~ s/0x([0-9a-f]+)/0$1h/ig;
 139             sprintf "%s",$self->{value};
 140         }
 141     }
 142 }
 143 { package ea;           # pick up effective addresses: expr(%reg,%reg,scale)
 144     sub re {
 145         my      $self = shift;  # single instance in enough...
 146         local   *line = shift;
 147         undef   $ret;
 148
 149         if ($line =~ /^([^\(,]*)\(([%\w,]+)\)/) {
 150             $self->{label} = $1;
 151             ($self->{base},$self->{index},$self->{scale})=split(/,/,$2);
 152             $self->{scale} = 1 if (!defined($self->{scale}));
 153             $ret = $self;
 154             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 155
 156             $self->{base}  =~ s/^%//;
 157             $self->{index} =~ s/^%// if (defined($self->{index}));
 158         }
 159         $ret;
 160     }
 161     sub size {}
 162     sub out {
 163         my $self = shift;
 164         my $sz = shift;
 165
 166         if (!$masm) {
 167             # elder GNU assembler insists on 64-bit EAs:-(
 168             # on pros side, this results in more compact code:-)
 169             $self->{index} =~ s/^[er](.?[0-9xp])[d]?$/r\1/;
 170             $self->{base}  =~ s/^[er](.?[0-9xp])[d]?$/r\1/;
 171             # Solaris /usr/ccs/bin/as can't handle multiplications
 172             # in $self->{label}
 173             $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/eg;
 174             $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
 175
 176             if (defined($self->{index})) {
 177                 sprintf "%s(%%%s,%%%s,%d)",
 178                                         $self->{label},$self->{base},
 179                                         $self->{index},$self->{scale};
 180             } else {
 181                 sprintf "%s(%%%s)",     $self->{label},$self->{base};
 182             }
 183         } else {
 184             %szmap = ( b=>"BYTE", w=>"WORD", l=>"DWORD", q=>"QWORD" );
 185
 186             $self->{label} =~ s/\./\$/g;
 187             $self->{label} =~ s/0x([0-9a-f]+)/0$1h/ig;
 188             $self->{label} = "($self->{label})" if ($self->{label} =~ /[\*\+\-\/]/);
 189
 190             if (defined($self->{index})) {
 191                 sprintf "%s PTR %s[%s*%d+%s]",$szmap{$sz},
 192                                         $self->{label},
 193                                         $self->{index},$self->{scale},
 194                                         $self->{base};
 195             } else {
 196                 sprintf "%s PTR %s[%s]",$szmap{$sz},
 197                                         $self->{label},$self->{base};
 198             }
 199         }
 200     }
 201 }
 202 { package register;     # pick up registers, which start with %.
 203     sub re {
 204         my      $class = shift; # muliple instances...
 205         my      $self = {};
 206         local   *line = shift;
 207         undef   $ret;
 208
 209         if ($line =~ /^%(\w+)/) {
 210             bless $self,$class;
 211             $self->{value} = $1;
 212             $ret = $self;
 213             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 214         }
 215         $ret;
 216     }
 217     sub size {
 218         my      $self = shift;
 219         undef   $ret;
 220
 221         if    ($self->{value} =~ /^r[\d]+b$/i)  { $ret="b"; }
 222         elsif ($self->{value} =~ /^r[\d]+w$/i)  { $ret="w"; }
 223         elsif ($self->{value} =~ /^r[\d]+d$/i)  { $ret="l"; }
 224         elsif ($self->{value} =~ /^r[\w]+$/i)   { $ret="q"; }
 225         elsif ($self->{value} =~ /^[a-d][hl]$/i){ $ret="b"; }
 226         elsif ($self->{value} =~ /^[\w]{2}l$/i) { $ret="b"; }
 227         elsif ($self->{value} =~ /^[\w]{2}$/i)  { $ret="w"; }
 228         elsif ($self->{value} =~ /^e[a-z]{2}$/i){ $ret="l"; }
 229
 230         $ret;
 231     }
 232     sub out {
 233         my $self = shift;
 234         sprintf $masm?"%s":"%%%s",$self->{value};
 235     }
 236 }
 237 { package label;        # pick up labels, which end with :
 238     sub re {
 239         my      $self = shift;  # single instance is enough...
 240         local   *line = shift;
 241         undef   $ret;
 242
 243         if ($line =~ /(^[\.\w]+\:)/) {
 244             $self->{value} = $1;
 245             $ret = $self;
 246             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 247
 248             $self->{value} =~ s/\.L/\$L/ if ($masm);
 249         }
 250         $ret;
 251     }
 252     sub out {
 253         my $self = shift;
 254
 255         if (!$masm) {
 256             $self->{value};
 257         } elsif ($self->{value} ne "$current_function->{name}:") {
 258             $self->{value};
 259         } elsif ($current_function->{abi} eq "svr4") {
 260             my $func =  "$current_function->{name}      PROC\n".
 261                         "       mov     QWORD PTR 8[rsp],rdi\t;WIN64 prologue\n".
 262                         "       mov     QWORD PTR 16[rsp],rsi\n";
 263             my $narg = $current_function->{narg};
 264             $narg=6 if (!defined($narg));
 265             $func .= "  mov     rdi,rcx\n" if ($narg>0);
 266             $func .= "  mov     rsi,rdx\n" if ($narg>1);
 267             $func .= "  mov     rdx,r8\n"  if ($narg>2);
 268             $func .= "  mov     rcx,r9\n"  if ($narg>3);
 269             $func .= "  mov     r8,QWORD PTR 40[rsp]\n" if ($narg>4);
 270             $func .= "  mov     r9,QWORD PTR 48[rsp]\n" if ($narg>5);
 271             $func .= "\n";
 272         } else {
 273            "$current_function->{name}   PROC";
 274         }
 275     }
 276 }
 277 { package expr;         # pick up expressioins
 278     sub re {
 279         my      $self = shift;  # single instance is enough...
 280         local   *line = shift;
 281         undef   $ret;
 282
 283         if ($line =~ /(^[^,]+)/) {
 284             $self->{value} = $1;
 285             $ret = $self;
 286             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 287
 288             $self->{value} =~ s/\.L/\$L/g if ($masm);
 289         }
 290         $ret;
 291     }
 292     sub out {
 293         my $self = shift;
 294         $self->{value};
 295     }
 296 }
 297 { package directive;    # pick up directives, which start with .
 298     sub re {
 299         my      $self = shift;  # single instance is enough...
 300         local   *line = shift;
 301         undef   $ret;
 302         my      $dir;
 303         my      %opcode =       # lea 2f-1f(%rip),%dst; 1: nop; 2:
 304                 (       "%rax"=>0x01058d48,     "%rcx"=>0x010d8d48,
 305                         "%rdx"=>0x01158d48,     "%rbx"=>0x011d8d48,
 306                         "%rsp"=>0x01258d48,     "%rbp"=>0x012d8d48,
 307                         "%rsi"=>0x01358d48,     "%rdi"=>0x013d8d48,
 308                         "%r8" =>0x01058d4c,     "%r9" =>0x010d8d4c,
 309                         "%r10"=>0x01158d4c,     "%r11"=>0x011d8d4c,
 310                         "%r12"=>0x01258d4c,     "%r13"=>0x012d8d4c,
 311                         "%r14"=>0x01358d4c,     "%r15"=>0x013d8d4c      );
 312
 313         if ($line =~ /^\s*(\.\w+)/) {
 314             if (!$masm) {
 315                 $self->{value} = $1;
 316                 $line =~ s/\@abi\-omnipotent/\@function/;
 317                 $line =~ s/\@function.*/\@function/;
 318                 if ($line =~ /\.picmeup\s+(%r[\w]+)/i) {
 319                     $self->{value} = sprintf "\t.long\t0x%x,0x90000000",$opcode{$1};
 320                 } else {
 321                     $self->{value} = $line;
 322                 }
 323                 $line = "";
 324                 return $self;
 325             }
 326
 327             $dir = $1;
 328             $ret = $self;
 329             undef $self->{value};
 330             $line = substr($line,@+[0]); $line =~ s/^\s+//;
 331             SWITCH: for ($dir) {
 332                 /\.(text)/
 333                             && do { my $v=undef;
 334                                     $v="$current_segment\tENDS\n" if ($current_segment);
 335                                     $current_segment = "_$1\$";
 336                                     $current_segment =~ tr/[a-z]/[A-Z]/;
 337                                     $v.="$current_segment\tSEGMENT ALIGN(64) 'CODE'";
 338                                     $self->{value} = $v;
 339                                     last;
 340                                   };
 341                 /\.globl/   && do { $self->{value} = "PUBLIC\t".$line; last; };
 342                 /\.type/    && do { ($sym,$type,$narg) = split(',',$line);
 343                                     if ($type eq "\@function") {
 344                                         undef $current_function;
 345                                         $current_function->{name} = $sym;
 346                                         $current_function->{abi}  = "svr4";
 347                                         $current_function->{narg} = $narg;
 348                                     } elsif ($type eq "\@abi-omnipotent") {
 349                                         undef $current_function;
 350                                         $current_function->{name} = $sym;
 351                                     }
 352                                     last;
 353                                   };
 354                 /\.size/    && do { if (defined($current_function)) {
 355                                         $self->{value}="$current_function->{name}\tENDP";
 356                                         undef $current_function;
 357                                     }
 358                                     last;
 359                                   };
 360                 /\.align/   && do { $self->{value} = "ALIGN\t".$line; last; };
 361                 /\.(byte|value|long|quad)/
 362                             && do { my @arr = split(',',$line);
 363                                     my $sz  = substr($1,0,1);
 364                                     my $last = pop(@arr);
 365
 366                                     $sz =~ tr/bvlq/BWDQ/;
 367                                     $self->{value} = "\tD$sz\t";
 368                                     for (@arr) { $self->{value} .= sprintf"0%Xh,",oct; }
 369                                     $self->{value} .= sprintf"0%Xh",oct($last);
 370                                     last;
 371                                   };
 372                 /\.picmeup/ && do { $self->{value} = sprintf"\tDD\t 0%Xh,090000000h",$opcode{$line};
 373                                     last;
 374                                   };
 375             }
 376             $line = "";
 377         }
 378
 379         $ret;
 380     }
 381     sub out {
 382         my $self = shift;
 383         $self->{value};
 384     }
 385 }
 386
 387 while($line=<>) {
 388
 389     chomp($line);
 390
 391     $line =~ s|[#!].*$||;       # get rid of asm-style comments...
 392     $line =~ s|/\*.*\*/||;      # ... and C-style comments...
 393     $line =~ s|^\s+||;          # ... and skip white spaces in beginning
 394
 395     undef $label;
 396     undef $opcode;
 397     undef $dst;
 398     undef $src;
 399     undef $sz;
 400
 401     if ($label=label->re(\$line))       { print $label->out(); }
 402
 403     if (directive->re(\$line)) {
 404         printf "%s",directive->out();
 405     } elsif ($opcode=opcode->re(\$line)) { ARGUMENT: {
 406
 407         if ($src=register->re(\$line))  { opcode->size($src->size()); }
 408         elsif ($src=const->re(\$line))  { }
 409         elsif ($src=ea->re(\$line))     { }
 410         elsif ($src=expr->re(\$line))   { }
 411
 412         last ARGUMENT if ($line !~ /^,/);
 413
 414         $line = substr($line,1); $line =~ s/^\s+//;
 415
 416         if ($dst=register->re(\$line))  { opcode->size($dst->size()); }
 417         elsif ($dst=const->re(\$line))  { }
 418         elsif ($dst=ea->re(\$line))     { }
 419
 420         } # ARGUMENT:
 421
 422         $sz=opcode->size();
 423
 424         if (defined($dst)) {
 425             if (!$masm) {
 426                 printf "\t%s\t%s,%s",   $opcode->out($dst->size()),
 427                                         $src->out($sz),$dst->out($sz);
 428             } else {
 429                 printf "\t%s\t%s,%s",   $opcode->out(),
 430                                         $dst->out($sz),$src->out($sz);
 431             }
 432         } elsif (defined($src)) {
 433             printf "\t%s\t%s",$opcode->out(),$src->out($sz);
 434         } else {
 435             printf "\t%s",$opcode->out();
 436         }
 437     }
 438
 439     print $line,"\n";
 440 }
 441
 442 print "\n$current_segment\tENDS\nEND\n" if ($masm);
 443
 444 close STDOUT;
 445
 446 #################################################
 447 # Cross-reference x86_64 ABI "card"
 448 #
 449 #               Unix            Win64
 450 # %rax          *               *
 451 # %rbx          -               -
 452 # %rcx          #4              #1
 453 # %rdx          #3              #2
 454 # %rsi          #2              -
 455 # %rdi          #1              -
 456 # %rbp          -               -
 457 # %rsp          -               -
 458 # %r8           #5              #3
 459 # %r9           #6              #4
 460 # %r10          *               *
 461 # %r11          *               *
 462 # %r12          -               -
 463 # %r13          -               -
 464 # %r14          -               -
 465 # %r15          -               -
 466 #
 467 # (*)   volatile register
 468 # (-)   preserved by callee
 469 # (#)   Nth argument, volatile
 470 #
 471 # In Unix terms top of stack is argument transfer area for arguments
 472 # which could not be accomodated in registers. Or in other words 7th
 473 # [integer] argument resides at 8(%rsp) upon function entry point.
 474 # 128 bytes above %rsp constitute a "red zone" which is not touched
 475 # by signal handlers and can be used as temporal storage without
 476 # allocating a frame.
 477 #
 478 # In Win64 terms N*8 bytes on top of stack is argument transfer area,
 479 # which belongs to/can be overwritten by callee. N is the number of
 480 # arguments passed to callee, *but* not less than 4! This means that
 481 # upon function entry point 5th argument resides at 40(%rsp), as well
 482 # as that 32 bytes from 8(%rsp) can always be used as temporal
 483 # storage [without allocating a frame].
 484 #
 485 # All the above means that if assembler programmer adheres to Unix
 486 # register and stack layout, but disregards the "red zone" existense,
 487 # it's possible to use following prologue and epilogue to "gear" from
 488 # Unix to Win64 ABI in leaf functions with not more than 6 arguments.
 489 #
 490 # omnipotent_function:
 491 # ifdef WIN64
 492 #       movq    %rdi,8(%rsp)
 493 #       movq    %rsi,16(%rsp)
 494 #       movq    %rcx,%rdi       ; if 1st argument is actually present
 495 #       movq    %rdx,%rsi       ; if 2nd argument is actually ...
 496 #       movq    %r8,%rdx        ; if 3rd argument is ...
 497 #       movq    %r9,%rcx        ; if 4th argument ...
 498 #       movq    40(%rsp),%r8    ; if 5th ...
 499 #       movq    48(%rsp),%r9    ; if 6th ...
 500 # endif
 501 #       ...
 502 # ifdef WIN64
 503 #       movq    8(%rsp),%rdi
 504 #       movq    16(%rsp),%rsi
 505 # endif
 506 #       ret