# B::Bytecode.pm
# Copyright (c) 2003 Enache Adrian. All rights reserved.
# This module is free software; you can redistribute and/or modify
# it under the same terms as Perl itself.
# Based on the original Bytecode.pm module written by Malcolm Beattie.
package B::Bytecode;
our $VERSION = '1.01_01';
use strict;
use Config;
use B qw(class main_cv main_root main_start cstring comppadlist
defstash curstash begin_av init_av end_av inc_gv warnhook diehook
dowarn SVt_PVGV SVt_PVHV OPf_SPECIAL OPf_STACKED OPf_MOD
OPpLVAL_INTRO SVf_FAKE SVf_READONLY);
use B::Asmdata qw(@specialsv_name);
use B::Assembler qw(asm newasm endasm);
#################################################
my ($varix, $opix, $savebegins, %walked, %files, @cloop);
my %strtab = (0,0);
my %svtab = (0,0);
my %optab = (0,0);
my %spectab = (0,0);
my $tix = 1;
sub asm;
sub nice ($) { }
BEGIN {
my $ithreads = $Config{'useithreads'} eq 'define';
eval qq{
sub ITHREADS() { $ithreads }
sub VERSION() { $] }
}; die $@ if $@;
}
#################################################
sub pvstring {
my $pv = shift;
defined($pv) ? cstring ($pv."\0") : "\"\"";
}
sub pvix {
my $str = pvstring shift;
my $ix = $strtab{$str};
defined($ix) ? $ix : do {
asm "newpv", $str;
asm "stpv", $strtab{$str} = $tix;
$tix++;
}
}
sub B::OP::ix {
my $op = shift;
my $ix = $optab{$$op};
defined($ix) ? $ix : do {
nice "[".$op->name." $tix]";
asm "newopx", $op->size | $op->type <<7;
$optab{$$op} = $opix = $ix = $tix++;
$op->bsave($ix);
$ix;
}
}
sub B::SPECIAL::ix {
my $spec = shift;
my $ix = $spectab{$$spec};
defined($ix) ? $ix : do {
nice '['.$specialsv_name[$$spec].']';
asm "ldspecsvx", $$spec;
$spectab{$$spec} = $varix = $tix++;
}
}
sub B::SV::ix {
my $sv = shift;
my $ix = $svtab{$$sv};
defined($ix) ? $ix : do {
nice '['.class($sv).']';
asm "newsvx", $sv->FLAGS;
$svtab{$$sv} = $varix = $ix = $tix++;
$sv->bsave($ix);
$ix;
}
}
sub B::GV::ix {
my ($gv,$desired) = @_;
my $ix = $svtab{$$gv};
defined($ix) ? $ix : do {
if ($gv->GP) {
my ($svix, $avix, $hvix, $cvix, $ioix, $formix);
nice "[GV]";
my $name = $gv->STASH->NAME . "::" . $gv->NAME;
asm "gv_fetchpvx", cstring $name;
$svtab{$$gv} = $varix = $ix = $tix++;
asm "sv_flags", $gv->FLAGS;
asm "sv_refcnt", $gv->REFCNT;
asm "xgv_flags", $gv->GvFLAGS;
asm "gp_refcnt", $gv->GvREFCNT;
asm "load_glob", $ix if $name eq "CORE::GLOBAL::glob";
return $ix
unless $desired || desired $gv;
$svix = $gv->SV->ix;
$avix = $gv->AV->ix;
$hvix = $gv->HV->ix;
# XXX {{{{
my $cv = $gv->CV;
$cvix = $$cv && defined $files{$cv->FILE} ? $cv->ix : 0;
my $form = $gv->FORM;
$formix = $$form && defined $files{$form->FILE} ? $form->ix : 0;
$ioix = $name !~ /STDOUT$/ ? $gv->IO->ix : 0;
# }}}} XXX
nice "-GV-",
asm "ldsv", $varix = $ix unless $ix == $varix;
asm "gp_sv", $svix;
asm "gp_av", $avix;
asm "gp_hv", $hvix;
asm "gp_cv", $cvix;
asm "gp_io", $ioix;
asm "gp_cvgen", $gv->CVGEN;
asm "gp_form", $formix;
asm "gp_file", pvix $gv->FILE;
asm "gp_line", $gv->LINE;
asm "formfeed", $svix if $name eq "main::\cL";
} else {
nice "[GV]";
asm "newsvx", $gv->FLAGS;
$svtab{$$gv} = $varix = $ix = $tix++;
my $stashix = $gv->STASH->ix;
$gv->B::PVMG::bsave($ix);
asm "xgv_flags", $gv->GvFLAGS;
asm "xgv_stash", $stashix;
}
$ix;
}
}
sub B::HV::ix {
my $hv = shift;
my $ix = $svtab{$$hv};
defined($ix) ? $ix : do {
my ($ix,$i,@array);
my $name = $hv->NAME;
if ($name) {
nice "[STASH]";
asm "gv_stashpvx", cstring $name;
asm "sv_flags", $hv->FLAGS;
$svtab{$$hv} = $varix = $ix = $tix++;
asm "xhv_name", pvix $name;
# my $pmrootix = $hv->PMROOT->ix; # XXX
asm "ldsv", $varix = $ix unless $ix == $varix;
# asm "xhv_pmroot", $pmrootix; # XXX
} else {
nice "[HV]";
asm "newsvx", $hv->FLAGS;
$svtab{$$hv} = $varix = $ix = $tix++;
my $stashix = $hv->SvSTASH->ix;
for (@array = $hv->ARRAY) {
next if $i = not $i;
$_ = $_->ix;
}
nice "-HV-",
asm "ldsv", $varix = $ix unless $ix == $varix;
($i = not $i) ? asm ("newpv", pvstring $_) : asm("hv_store", $_)
for @array;
if (VERSION < 5.009) {
asm "xnv", $hv->NVX;
}
asm "xmg_stash", $stashix;
asm "xhv_riter", $hv->RITER;
}
asm "sv_refcnt", $hv->REFCNT;
$ix;
}
}
sub B::NULL::ix {
my $sv = shift;
$$sv ? $sv->B::SV::ix : 0;
}
sub B::NULL::opwalk { 0 }
#################################################
sub B::NULL::bsave {
my ($sv,$ix) = @_;
nice '-'.class($sv).'-',
asm "ldsv", $varix = $ix unless $ix == $varix;
asm "sv_refcnt", $sv->REFCNT;
}
sub B::SV::bsave;
*B::SV::bsave = *B::NULL::bsave;
sub B::RV::bsave {
my ($sv,$ix) = @_;
my $rvix = $sv->RV->ix;
$sv->B::NULL::bsave($ix);
asm "xrv", $rvix;
}
sub B::PV::bsave {
my ($sv,$ix) = @_;
$sv->B::NULL::bsave($ix);
asm "newpv", pvstring $sv->PVBM;
asm "xpv";
}
sub B::IV::bsave {
my ($sv,$ix) = @_;
$sv->B::NULL::bsave($ix);
asm "xiv", $sv->IVX;
}
sub B::NV::bsave {
my ($sv,$ix) = @_;
$sv->B::NULL::bsave($ix);
asm "xnv", sprintf "%.40g", $sv->NVX;
}
sub B::PVIV::bsave {
my ($sv,$ix) = @_;
$sv->POK ?
$sv->B::PV::bsave($ix):
$sv->ROK ?
$sv->B::RV::bsave($ix):
$sv->B::NULL::bsave($ix);
if (VERSION >= 5.009) {
# See note below in B::PVNV::bsave
return if $sv->isa('B::AV');
return if $sv->isa('B::HV');
}
asm "xiv", !ITHREADS && $sv->FLAGS & (SVf_FAKE|SVf_READONLY) ?
"0 but true" : $sv->IVX;
}
sub B::PVNV::bsave {
my ($sv,$ix) = @_;
$sv->B::PVIV::bsave($ix);
if (VERSION >= 5.009) {
# Magical AVs end up here, but AVs now don't have an NV slot actually
# allocated. Hence don't write out assembly to store the NV slot if
# we're actually an array.
return if $sv->isa('B::AV');
# Likewise HVs have no NV slot actually allocated.
# I don't think that they can get here, but better safe than sorry
return if $sv->isa('B::HV');
}
asm "xnv", sprintf "%.40g", $sv->NVX;
}
sub B::PVMG::domagic {
my ($sv,$ix) = @_;
nice '-MAGICAL-';
my @mglist = $sv->MAGIC;
my (@mgix, @namix);
for (@mglist) {
push @mgix, $_->OBJ->ix;
push @namix, $_->PTR->ix if $_->LENGTH == B::HEf_SVKEY;
}
nice '-'.class($sv).'-',
asm "ldsv", $varix = $ix unless $ix == $varix;
for (@mglist) {
asm "sv_magic", cstring $_->TYPE;
asm "mg_obj", shift @mgix;
my $length = $_->LENGTH;
if ($length == B::HEf_SVKEY) {
asm "mg_namex", shift @namix;
} elsif ($length) {
asm "newpv", pvstring $_->PTR;
asm "mg_name";
}
}
}
sub B::PVMG::bsave {
my ($sv,$ix) = @_;
my $stashix = $sv->SvSTASH->ix;
$sv->B::PVNV::bsave($ix);
asm "xmg_stash", $stashix;
$sv->domagic($ix) if $sv->MAGICAL;
}
sub B::PVLV::bsave {
my ($sv,$ix) = @_;
my $targix = $sv->TARG->ix;
$sv->B::PVMG::bsave($ix);
asm "xlv_targ", $targix;
asm "xlv_targoff", $sv->TARGOFF;
asm "xlv_targlen", $sv->TARGLEN;
asm "xlv_type", $sv->TYPE;
}
sub B::BM::bsave {
my ($sv,$ix) = @_;
$sv->B::PVMG::bsave($ix);
asm "xpv_cur", $sv->CUR;
asm "xbm_useful", $sv->USEFUL;
asm "xbm_previous", $sv->PREVIOUS;
asm "xbm_rare", $sv->RARE;
}
sub B::IO::bsave {
my ($io,$ix) = @_;
my $topix = $io->TOP_GV->ix;
my $fmtix = $io->FMT_GV->ix;
my $bottomix = $io->BOTTOM_GV->ix;
$io->B::PVMG::bsave($ix);
asm "xio_lines", $io->LINES;
asm "xio_page", $io->PAGE;
asm "xio_page_len", $io->PAGE_LEN;
asm "xio_lines_left", $io->LINES_LEFT;
asm "xio_top_name", pvix $io->TOP_NAME;
asm "xio_top_gv", $topix;
asm "xio_fmt_name", pvix $io->FMT_NAME;
asm "xio_fmt_gv", $fmtix;
asm "xio_bottom_name", pvix $io->BOTTOM_NAME;
asm "xio_bottom_gv", $bottomix;
asm "xio_subprocess", $io->SUBPROCESS;
asm "xio_type", ord $io->IoTYPE;
# asm "xio_flags", ord($io->IoFLAGS) & ~32; # XXX XXX
}
sub B::CV::bsave {
my ($cv,$ix) = @_;
my $stashix = $cv->STASH->ix;
my $gvix = $cv->GV->ix;
my $padlistix = $cv->PADLIST->ix;
my $outsideix = $cv->OUTSIDE->ix;
my $constix = $cv->CONST ? $cv->XSUBANY->ix : 0;
my $startix = $cv->START->opwalk;
my $rootix = $cv->ROOT->ix;
$cv->B::PVMG::bsave($ix);
asm "xcv_stash", $stashix;
asm "xcv_start", $startix;
asm "xcv_root", $rootix;
asm "xcv_xsubany", $constix;
asm "xcv_gv", $gvix;
asm "xcv_file", pvix $cv->FILE if $cv->FILE; # XXX AD
asm "xcv_padlist", $padlistix;
asm "xcv_outside", $outsideix;
asm "xcv_flags", $cv->CvFLAGS;
asm "xcv_outside_seq", $cv->OUTSIDE_SEQ;
asm "xcv_depth", $cv->DEPTH;
}
sub B::FM::bsave {
my ($form,$ix) = @_;
$form->B::CV::bsave($ix);
asm "xfm_lines", $form->LINES;
}
sub B::AV::bsave {
my ($av,$ix) = @_;
return $av->B::PVMG::bsave($ix) if $av->MAGICAL;
my @array = $av->ARRAY;
$_ = $_->ix for @array;
my $stashix = $av->SvSTASH->ix;
nice "-AV-",
asm "ldsv", $varix = $ix unless $ix == $varix;
asm "av_extend", $av->MAX if $av->MAX >= 0;
asm "av_pushx", $_ for @array;
asm "sv_refcnt", $av->REFCNT;
if (VERSION < 5.009) {
asm "xav_flags", $av->AvFLAGS;
}
asm "xmg_stash", $stashix;
}
sub B::GV::desired {
my $gv = shift;
my ($cv, $form);
$files{$gv->FILE} && $gv->LINE
|| ${$cv = $gv->CV} && $files{$cv->FILE}
|| ${$form = $gv->FORM} && $files{$form->FILE}
}
sub B::HV::bwalk {
my $hv = shift;
return if $walked{$$hv}++;
my %stash = $hv->ARRAY;
while (my($k,$v) = each %stash) {
if ($v->SvTYPE == SVt_PVGV) {
my $hash = $v->HV;
if ($$hash && $hash->NAME) {
$hash->bwalk;
}
$v->ix(1) if desired $v;
} else {
nice "[prototype]";
asm "gv_fetchpvx", cstring $hv->NAME . "::$k";
$svtab{$$v} = $varix = $tix;
$v->bsave($tix++);
asm "sv_flags", $v->FLAGS;
}
}
}
######################################################
sub B::OP::bsave_thin {
my ($op, $ix) = @_;
my $next = $op->next;
my $nextix = $optab{$$next};
$nextix = 0, push @cloop, $op unless defined $nextix;
if ($ix != $opix) {
nice '-'.$op->name.'-',
asm "ldop", $opix = $ix;
}
asm "op_next", $nextix;
asm "op_targ", $op->targ if $op->type; # tricky
asm "op_flags", $op->flags;
asm "op_private", $op->private;
}
sub B::OP::bsave;
*B::OP::bsave = *B::OP::bsave_thin;
sub B::UNOP::bsave {
my ($op, $ix) = @_;
my $name = $op->name;
my $flags = $op->flags;
my $first = $op->first;
my $firstix =
$name =~ /fl[io]p/
# that's just neat
|| (!ITHREADS && $name eq 'regcomp')
# trick for /$a/o in pp_regcomp
|| $name eq 'rv2sv'
&& $op->flags & OPf_MOD
&& $op->private & OPpLVAL_INTRO
# change #18774 made my life hard
? $first->ix
: 0;
$op->B::OP::bsave($ix);
asm "op_first", $firstix;
}
sub B::BINOP::bsave {
my ($op, $ix) = @_;
if ($op->name eq 'aassign' && $op->private & B::OPpASSIGN_HASH()) {
my $last = $op->last;
my $lastix = do {
local *B::OP::bsave = *B::OP::bsave_fat;
local *B::UNOP::bsave = *B::UNOP::bsave_fat;
$last->ix;
};
asm "ldop", $lastix unless $lastix == $opix;
asm "op_targ", $last->targ;
$op->B::OP::bsave($ix);
asm "op_last", $lastix;
} else {
$op->B::OP::bsave($ix);
}
}
# not needed if no pseudohashes
*B::BINOP::bsave = *B::OP::bsave if VERSION >= 5.009;
# deal with sort / formline
sub B::LISTOP::bsave {
my ($op, $ix) = @_;
my $name = $op->name;
sub blocksort() { OPf_SPECIAL|OPf_STACKED }
if ($name eq 'sort' && ($op->flags & blocksort) == blocksort) {
my $first = $op->first;
my $pushmark = $first->sibling;
my $rvgv = $pushmark->first;
my $leave = $rvgv->first;
my $leaveix = $leave->ix;
my $rvgvix = $rvgv->ix;
asm "ldop", $rvgvix unless $rvgvix == $opix;
asm "op_first", $leaveix;
my $pushmarkix = $pushmark->ix;
asm "ldop", $pushmarkix unless $pushmarkix == $opix;
asm "op_first", $rvgvix;
my $firstix = $first->ix;
asm "ldop", $firstix unless $firstix == $opix;
asm "op_sibling", $pushmarkix;
$op->B::OP::bsave($ix);
asm "op_first", $firstix;
} elsif ($name eq 'formline') {
$op->B::UNOP::bsave_fat($ix);
} else {
$op->B::OP::bsave($ix);
}
}
# fat versions
sub B::OP::bsave_fat {
my ($op, $ix) = @_;
my $siblix = $op->sibling->ix;
$op->B::OP::bsave_thin($ix);
asm "op_sibling", $siblix;
# asm "op_seq", -1; XXX don't allocate OPs piece by piece
}
sub B::UNOP::bsave_fat {
my ($op,$ix) = @_;
my $firstix = $op->first->ix;
$op->B::OP::bsave($ix);
asm "op_first", $firstix;
}
sub B::BINOP::bsave_fat {
my ($op,$ix) = @_;
my $last = $op->last;
my $lastix = $op->last->ix;
if (VERSION < 5.009 && $op->name eq 'aassign' && $last->name eq 'null') {
asm "ldop", $lastix unless $lastix == $opix;
asm "op_targ", $last->targ;
}
$op->B::UNOP::bsave($ix);
asm "op_last", $lastix;
}
sub B::LOGOP::bsave {
my ($op,$ix) = @_;
my $otherix = $op->other->ix;
$op->B::UNOP::bsave($ix);
asm "op_other", $otherix;
}
sub B::PMOP::bsave {
my ($op,$ix) = @_;
my ($rrop, $rrarg, $rstart);
# my $pmnextix = $op->pmnext->ix; # XXX
if (ITHREADS) {
if ($op->name eq 'subst') {
$rrop = "op_pmreplroot";
$rrarg = $op->pmreplroot->ix;
$rstart = $op->pmreplstart->ix;
} elsif ($op->name eq 'pushre') {
$rrop = "op_pmreplrootpo";
$rrarg = $op->pmreplroot;
}
$op->B::BINOP::bsave($ix);
asm "op_pmstashpv", pvix $op->pmstashpv;
} else {
$rrop = "op_pmreplrootgv";
$rrarg = $op->pmreplroot->ix;
$rstart = $op->pmreplstart->ix if $op->name eq 'subst';
my $stashix = $op->pmstash->ix;
$op->B::BINOP::bsave($ix);
asm "op_pmstash", $stashix;
}
asm $rrop, $rrarg if $rrop;
asm "op_pmreplstart", $rstart if $rstart;
asm "op_pmflags", $op->pmflags;
asm "op_pmpermflags", $op->pmpermflags;
asm "op_pmdynflags", $op->pmdynflags;
# asm "op_pmnext", $pmnextix; # XXX
asm "newpv", pvstring $op->precomp;
asm "pregcomp";
}
sub B::SVOP::bsave {
my ($op,$ix) = @_;
my $svix = $op->sv->ix;
$op->B::OP::bsave($ix);
asm "op_sv", $svix;
}
sub B::PADOP::bsave {
my ($op,$ix) = @_;
$op->B::OP::bsave($ix);
asm "op_padix", $op->padix;
}
sub B::PVOP::bsave {
my ($op,$ix) = @_;
$op->B::OP::bsave($ix);
return unless my $pv = $op->pv;
if ($op->name eq 'trans') {
asm "op_pv_tr", join ',', length($pv)/2, unpack("s*", $pv);
} else {
asm "newpv", pvstring $pv;
asm "op_pv";
}
}
sub B::LOOP::bsave {
my ($op,$ix) = @_;
my $nextix = $op->nextop->ix;
my $lastix = $op->lastop->ix;
my $redoix = $op->redoop->ix;
$op->B::BINOP::bsave($ix);
asm "op_redoop", $redoix;
asm "op_nextop", $nextix;
asm "op_lastop", $lastix;
}
sub B::COP::bsave {
my ($cop,$ix) = @_;
my $warnix = $cop->warnings->ix;
my $ioix = $cop->io->ix;
if (ITHREADS) {
$cop->B::OP::bsave($ix);
asm "cop_stashpv", pvix $cop->stashpv;
asm "cop_file", pvix $cop->file;
} else {
my $stashix = $cop->stash->ix;
my $fileix = $cop->filegv->ix(1);
$cop->B::OP::bsave($ix);
asm "cop_stash", $stashix;
asm "cop_filegv", $fileix;
}
asm "cop_label", pvix $cop->label if $cop->label; # XXX AD
asm "cop_seq", $cop->cop_seq;
asm "cop_arybase", $cop->arybase;
asm "cop_line", $cop->line;
asm "cop_warnings", $warnix;
asm "cop_io", $ioix;
}
sub B::OP::opwalk {
my $op = shift;
my $ix = $optab{$$op};
defined($ix) ? $ix : do {
my $ix;
my @oplist = $op->oplist;
push @cloop, undef;
$ix = $_->ix while $_ = pop @oplist;
while ($_ = pop @cloop) {
asm "ldop", $optab{$$_};
asm "op_next", $optab{${$_->next}};
}
$ix;
}
}
#################################################
sub save_cq {
my $av;
if (($av=begin_av)->isa("B::AV")) {
if ($savebegins) {
for ($av->ARRAY) {
next unless $_->FILE eq $0;
asm "push_begin", $_->ix;
}
} else {
for ($av->ARRAY) {
next unless $_->FILE eq $0;
# XXX BEGIN { goto A while 1; A: }
for (my $op = $_->START; $$op; $op = $op->next) {
next unless $op->name eq 'require' ||
# this kludge needed for tests
$op->name eq 'gv' && do {
my $gv = class($op) eq 'SVOP' ?
$op->gv :
(($_->PADLIST->ARRAY)[1]->ARRAY)[$op->padix];
$$gv && $gv->NAME =~ /use_ok|plan/
};
asm "push_begin", $_->ix;
last;
}
}
}
}
if (($av=init_av)->isa("B::AV")) {
for ($av->ARRAY) {
next unless $_->FILE eq $0;
asm "push_init", $_->ix;
}
}
if (($av=end_av)->isa("B::AV")) {
for ($av->ARRAY) {
next unless $_->FILE eq $0;
asm "push_end", $_->ix;
}
}
}
sub compile {
my ($head, $scan, $T_inhinc, $keep_syn);
my $cwd = '';
$files{$0} = 1;
sub keep_syn {
$keep_syn = 1;
*B::OP::bsave = *B::OP::bsave_fat;
*B::UNOP::bsave = *B::UNOP::bsave_fat;
*B::BINOP::bsave = *B::BINOP::bsave_fat;
*B::LISTOP::bsave = *B::LISTOP::bsave_fat;
}
sub bwarn { print STDERR "Bytecode.pm: @_\n" }
for (@_) {
if (/^-S/) {
*newasm = *endasm = sub { };
*asm = sub { print " @_\n" };
*nice = sub ($) { print "\n@_\n" };
} elsif (/^-H/) {
require ByteLoader;
$head = "#! $^X\nuse ByteLoader $ByteLoader::VERSION;\n";
} elsif (/^-k/) {
keep_syn;
} elsif (/^-o(.*)$/) {
open STDOUT, ">$1" or die "open $1: $!";
} elsif (/^-f(.*)$/) {
$files{$1} = 1;
} elsif (/^-s(.*)$/) {
$scan = length($1) ? $1 : $0;
} elsif (/^-b/) {
$savebegins = 1;
# this is here for the testsuite
} elsif (/^-TI/) {
$T_inhinc = 1;
} elsif (/^-TF(.*)/) {
my $thatfile = $1;
*B::COP::file = sub { $thatfile };
} else {
bwarn "Ignoring '$_' option";
}
}
if ($scan) {
my $f;
if (open $f, $scan) {
while (<$f>) {
/^#\s*line\s+\d+\s+("?)(.*)\1/ and $files{$2} = 1;
/^#/ and next;
if (/\bgoto\b\s*[^&]/ && !$keep_syn) {
bwarn "keeping the syntax tree: \"goto\" op found";
keep_syn;
}
}
} else {
bwarn "cannot rescan '$scan'";
}
close $f;
}
binmode STDOUT;
return sub {
print $head if $head;
newasm sub { print @_ };
defstash->bwalk;
asm "main_start", main_start->opwalk;
asm "main_root", main_root->ix;
asm "main_cv", main_cv->ix;
asm "curpad", (comppadlist->ARRAY)[1]->ix;
asm "signal", cstring "__WARN__" # XXX
if warnhook->ix;
asm "incav", inc_gv->AV->ix if $T_inhinc;
save_cq;
asm "incav", inc_gv->AV->ix if $T_inhinc;
asm "dowarn", dowarn;
{
no strict 'refs';
nice "<DATA>";
my $dh = *{defstash->NAME."::DATA"};
unless (eof $dh) {
local undef $/;
asm "data", ord 'D';
print <$dh>;
} else {
asm "ret";
}
}
endasm;
}
}
1;
=head1 NAME
B::Bytecode - Perl compiler's bytecode backend
=head1 SYNOPSIS
B<perl -MO=Bytecode>[B<,-H>][B<,-o>I<script.plc>] I<script.pl>
=head1 DESCRIPTION
Compiles a Perl script into a bytecode format that could be loaded
later by the ByteLoader module and executed as a regular Perl script.
=head1 EXAMPLE
$ perl -MO=Bytecode,-H,-ohi -e 'print "hi!\n"'
$ perl hi
hi!
=head1 OPTIONS
=over 4
=item B<-b>
Save all the BEGIN blocks. Normally only BEGIN blocks that C<require>
other files (ex. C<use Foo;>) are saved.
=item B<-H>
prepend a C<use ByteLoader VERSION;> line to the produced bytecode.
=item B<-k>
keep the syntax tree - it is stripped by default.
=item B<-o>I<outfile>
put the bytecode in <outfile> instead of dumping it to STDOUT.
=item B<-s>
scan the script for C<# line ..> directives and for <goto LABEL>
expressions. When gotos are found keep the syntax tree.
=back
=head1 KNOWN BUGS
=over 4
=item *
C<BEGIN { goto A: while 1; A: }> won't even compile.
=item *
C<?...?> and C<reset> do not work as expected.
=item *
variables in C<(?{ ... })> constructs are not properly scoped.
=item *
scripts that use source filters will fail miserably.
=back
=head1 NOTICE
There are also undocumented bugs and options.
THIS CODE IS HIGHLY EXPERIMENTAL. USE AT YOUR OWN RISK.
=head1 AUTHORS
Originally written by Malcolm Beattie <mbeattie@sable.ox.ac.uk> and
modified by Benjamin Stuhl <sho_pi@hotmail.com>.
Rewritten by Enache Adrian <enache@rdslink.ro>, 2003 a.d.
=cut