The Tor Browser: media/libopus/celt/arm/arm2gnu.pl@ac0c01689b40 (annotated)

media/libopus/celt/arm/arm2gnu.pl@ac0c01689b40 (annotated)

media/libopus/celt/arm/arm2gnu.pl

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rwxr-xr-x

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 #!/usr/bin/perl
 my $bigend;  # little/big endian
 my $nxstack;
 $nxstack = 0;
 eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}'
     if $running_under_some_shell;
 while ($ARGV[0] =~ /^-/) {
     $_ = shift;
   last if /^--/;
     if (/^-n/) {
     $nflag++;
     next;
     }
     die "I don't recognize this switch: $_\\n";
 }
 $printit++ unless $nflag;
 $\ = "\n";      # automatically add newline on print
 $n=0;
 $thumb = 0;     # ARM mode by default, not Thumb.
 @proc_stack = ();
 LINE:
 while (<>) {
     # For ADRLs we need to add a new line after the substituted one.
     $addPadding = 0;
     # First, we do not dare to touch *anything* inside double quotes, do we?
     # Second, if you want a dollar character in the string,
     # insert two of them -- that's how ARM C and assembler treat strings.
     s/^([A-Za-z_]\w*)[ \t]+DCB[ \t]*\"/$1:   .ascii \"/   && do { s/\$\$/\$/g; next };
     s/\bDCB\b[ \t]*\"/.ascii \"/                          && do { s/\$\$/\$/g; next };
     s/^(\S+)\s+RN\s+(\S+)/$1 .req r$2/                    && do { s/\$\$/\$/g; next };
     # If there's nothing on a line but a comment, don't try to apply any further
     #  substitutions (this is a cheap hack to avoid mucking up the license header)
     s/^([ \t]*);/$1@/                                     && do { s/\$\$/\$/g; next };
     # If substituted -- leave immediately !
     s/@/,:/;
     s/;/@/;
     while ( /@.*'/ ) {
       s/(@.*)'/$1/g;
     }
     s/\{FALSE\}/0/g;
     s/\{TRUE\}/1/g;
     s/\{(\w\w\w\w+)\}/$1/g;
     s/\bINCLUDE[ \t]*([^ \t\n]+)/.include \"$1\"/;
     s/\bGET[ \t]*([^ \t\n]+)/.include \"${ my $x=$1; $x =~ s|\.s|-gnu.S|; \$x }\"/;
     s/\bIMPORT\b/.extern/;
     s/\bEXPORT\b/.global/;
     s/^(\s+)\[/$1IF/;
     s/^(\s+)\|/$1ELSE/;
     s/^(\s+)\]/$1ENDIF/;
     s/IF *:DEF:/ .ifdef/;
     s/IF *:LNOT: *:DEF:/ .ifndef/;
     s/ELSE/ .else/;
     s/ENDIF/ .endif/;
     if( /\bIF\b/ ) {
       s/\bIF\b/ .if/;
       s/=/==/;
     }
     if ( $n == 2) {
         s/\$/\\/g;
     }
     if ($n == 1) {
         s/\$//g;
         s/label//g;
     $n = 2;
       }
     if ( /MACRO/ ) {
       s/MACRO *\n/.macro/;
       $n=1;
     }
     if ( /\bMEND\b/ ) {
       s/\bMEND\b/.endm/;
       $n=0;
     }
     # ".rdata" doesn't work in 'as' version 2.13.2, as it is ".rodata" there.
     #
     if ( /\bAREA\b/ ) {
         my $align;
         $align = "2";
         if ( /ALIGN=(\d+)/ ) {
             $align = $1;
         }
         if ( /CODE/ ) {
             $nxstack = 1;
         }
         s/^(.+)CODE(.+)READONLY(.*)/    .text/;
         s/^(.+)DATA(.+)READONLY(.*)/    .section .rdata/;
         s/^(.+)\|\|\.data\|\|(.+)/    .data/;
         s/^(.+)\|\|\.bss\|\|(.+)/    .bss/;
         s/$/;   .p2align $align/;
         # Enable NEON instructions but don't produce a binary that requires
         # ARMv7. RVCT does not have equivalent directives, so we just do this
         # for all CODE areas.
         if ( /.text/ ) {
             # Separating .arch, .fpu, etc., by semicolons does not work (gas
             # thinks the semicolon is part of the arch name, even when there's
             # whitespace separating them). Sadly this means our line numbers
             # won't match the original source file (we could use the .line
             # directive, which is documented to be obsolete, but then gdb will
             # show the wrong line in the translated source file).
             s/$/;   .arch armv7-a\n   .fpu neon\n   .object_arch armv4t/;
         }
     }
     s/\|\|\.constdata\$(\d+)\|\|/.L_CONST$1/;       # ||.constdata$3||
     s/\|\|\.bss\$(\d+)\|\|/.L_BSS$1/;               # ||.bss$2||
     s/\|\|\.data\$(\d+)\|\|/.L_DATA$1/;             # ||.data$2||
     s/\|\|([a-zA-Z0-9_]+)\@([a-zA-Z0-9_]+)\|\|/@ $&/;
     s/^(\s+)\%(\s)/    .space $1/;
     s/\|(.+)\.(\d+)\|/\.$1_$2/;                     # |L80.123| -> .L80_123
     s/\bCODE32\b/.code 32/ && do {$thumb = 0};
     s/\bCODE16\b/.code 16/ && do {$thumb = 1};
     if (/\bPROC\b/)
     {
         my $prefix;
         my $proc;
         /^([A-Za-z_\.]\w+)\b/;
         $proc = $1;
         $prefix = "";
         if ($proc)
         {
             $prefix = $prefix.sprintf("\t.type\t%s, %%function; ",$proc);
             push(@proc_stack, $proc);
             s/^[A-Za-z_\.]\w+/$&:/;
         }
         $prefix = $prefix."\t.thumb_func; " if ($thumb);
         s/\bPROC\b/@ $&/;
         $_ = $prefix.$_;
     }
     s/^(\s*)(S|Q|SH|U|UQ|UH)ASX\b/$1$2ADDSUBX/;
     s/^(\s*)(S|Q|SH|U|UQ|UH)SAX\b/$1$2SUBADDX/;
     if (/\bENDP\b/)
     {
         my $proc;
         s/\bENDP\b/@ $&/;
         $proc = pop(@proc_stack);
         $_ = "\t.size $proc, .-$proc".$_ if ($proc);
     }
     s/\bSUBT\b/@ $&/;
     s/\bDATA\b/@ $&/;   # DATA directive is deprecated -- Asm guide, p.7-25
     s/\bKEEP\b/@ $&/;
     s/\bEXPORTAS\b/@ $&/;
     s/\|\|(.)+\bEQU\b/@ $&/;
     s/\|\|([\w\$]+)\|\|/$1/;
     s/\bENTRY\b/@ $&/;
     s/\bASSERT\b/@ $&/;
     s/\bGBLL\b/@ $&/;
     s/\bGBLA\b/@ $&/;
     s/^\W+OPT\b/@ $&/;
     s/:OR:/|/g;
     s/:SHL:/<</g;
     s/:SHR:/>>/g;
     s/:AND:/&/g;
     s/:LAND:/&&/g;
     s/CPSR/cpsr/;
     s/SPSR/spsr/;
     s/ALIGN$/.balign 4/;
     s/ALIGN\s+([0-9x]+)$/.balign $1/;
     s/psr_cxsf/psr_all/;
     s/LTORG/.ltorg/;
     s/^([A-Za-z_]\w*)[ \t]+EQU/ .set $1,/;
     s/^([A-Za-z_]\w*)[ \t]+SETL/ .set $1,/;
     s/^([A-Za-z_]\w*)[ \t]+SETA/ .set $1,/;
     s/^([A-Za-z_]\w*)[ \t]+\*/ .set $1,/;
     #  {PC} + 0xdeadfeed  -->  . + 0xdeadfeed
     s/\{PC\} \+/ \. +/;
     # Single hex constant on the line !
     #
     # >>> NOTE <<<
     #   Double-precision floats in gcc are always mixed-endian, which means
     #   bytes in two words are little-endian, but words are big-endian.
     #   So, 0x0000deadfeed0000 would be stored as 0x0000dead at low address
     #   and 0xfeed0000 at high address.
     #
     s/\bDCFD\b[ \t]+0x([a-fA-F0-9]{8})([a-fA-F0-9]{8})/.long 0x$1, 0x$2/;
     # Only decimal constants on the line, no hex !
     s/\bDCFD\b[ \t]+([0-9\.\-]+)/.double $1/;
     # Single hex constant on the line !
 #    s/\bDCFS\b[ \t]+0x([a-f0-9]{8})([a-f0-9]{8})/.long 0x$1, 0x$2/;
     # Only decimal constants on the line, no hex !
 #    s/\bDCFS\b[ \t]+([0-9\.\-]+)/.double $1/;
     s/\bDCFS[ \t]+0x/.word 0x/;
     s/\bDCFS\b/.float/;
     s/^([A-Za-z_]\w*)[ \t]+DCD/$1 .word/;
     s/\bDCD\b/.word/;
     s/^([A-Za-z_]\w*)[ \t]+DCW/$1 .short/;
     s/\bDCW\b/.short/;
     s/^([A-Za-z_]\w*)[ \t]+DCB/$1 .byte/;
     s/\bDCB\b/.byte/;
     s/^([A-Za-z_]\w*)[ \t]+\%/.comm $1,/;
     s/^[A-Za-z_\.]\w+/$&:/;
     s/^(\d+)/$1:/;
     s/\%(\d+)/$1b_or_f/;
     s/\%[Bb](\d+)/$1b/;
     s/\%[Ff](\d+)/$1f/;
     s/\%[Ff][Tt](\d+)/$1f/;
     s/&([\dA-Fa-f]+)/0x$1/;
     if ( /\b2_[01]+\b/ ) {
       s/\b2_([01]+)\b/conv$1&&&&/g;
       while ( /[01][01][01][01]&&&&/ ) {
         s/0000&&&&/&&&&0/g;
         s/0001&&&&/&&&&1/g;
         s/0010&&&&/&&&&2/g;
         s/0011&&&&/&&&&3/g;
         s/0100&&&&/&&&&4/g;
         s/0101&&&&/&&&&5/g;
         s/0110&&&&/&&&&6/g;
         s/0111&&&&/&&&&7/g;
         s/1000&&&&/&&&&8/g;
         s/1001&&&&/&&&&9/g;
         s/1010&&&&/&&&&A/g;
         s/1011&&&&/&&&&B/g;
         s/1100&&&&/&&&&C/g;
         s/1101&&&&/&&&&D/g;
         s/1110&&&&/&&&&E/g;
         s/1111&&&&/&&&&F/g;
       }
       s/000&&&&/&&&&0/g;
       s/001&&&&/&&&&1/g;
       s/010&&&&/&&&&2/g;
       s/011&&&&/&&&&3/g;
       s/100&&&&/&&&&4/g;
       s/101&&&&/&&&&5/g;
       s/110&&&&/&&&&6/g;
       s/111&&&&/&&&&7/g;
       s/00&&&&/&&&&0/g;
       s/01&&&&/&&&&1/g;
       s/10&&&&/&&&&2/g;
       s/11&&&&/&&&&3/g;
       s/0&&&&/&&&&0/g;
       s/1&&&&/&&&&1/g;
       s/conv&&&&/0x/g;
     }
     if ( /commandline/)
     {
         if( /-bigend/)
         {
             $bigend=1;
         }
     }
     if ( /\bDCDU\b/ )
     {
         my $cmd=$_;
         my $value;
         my $prefix;
         my $w1;
         my $w2;
         my $w3;
         my $w4;
         s/\s+DCDU\b/@ $&/;
         $cmd =~ /\bDCDU\b\s+0x(\d+)/;
         $value = $1;
         $value =~ /(\w\w)(\w\w)(\w\w)(\w\w)/;
         $w1 = $1;
         $w2 = $2;
         $w3 = $3;
         $w4 = $4;
         if( $bigend ne "")
         {
             # big endian
             $prefix = "\t.byte\t0x".$w1.";".
                       "\t.byte\t0x".$w2.";".
                       "\t.byte\t0x".$w3.";".
                       "\t.byte\t0x".$w4."; ";
         }
         else
         {
             # little endian
             $prefix = "\t.byte\t0x".$w4.";".
                       "\t.byte\t0x".$w3.";".
                       "\t.byte\t0x".$w2.";".
                       "\t.byte\t0x".$w1."; ";
         }
         $_=$prefix.$_;
     }
     if ( /\badrl\b/i )
     {
         s/\badrl\s+(\w+)\s*,\s*(\w+)/ldr $1,=$2/i;
         $addPadding = 1;
     }
     s/\bEND\b/@ END/;
 } continue {
     printf ("%s", $_) if $printit;
     if ($addPadding != 0)
     {
         printf ("   mov r0,r0\n");
         $addPadding = 0;
     }
 }
 #If we had a code section, mark that this object doesn't need an executable
 # stack.
 if ($nxstack) {
     printf ("    .section\t.note.GNU-stack,\"\",\%\%progbits\n");
 }

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media/libopus/celt/arm/arm2gnu.pl@ac0c01689b40 (annotated)

media/libopus/celt/arm/arm2gnu.pl