3 # Copyright (c) 1996-1998 Malcolm Beattie
5 # You may distribute under the terms of either the GNU General Public
6 # License or the Artistic License, as specified in the README file.
13 use B qw(minus_c main_cv main_root main_start comppadlist
14 class peekop walkoptree svref_2object cstring walksymtable
15 SVf_POK SVp_POK SVf_IOK SVp_IOK
17 use B::Asmdata qw(@optype @specialsv_name);
18 use B::Assembler qw(assemble_fh);
22 for ($i = 0; $i < @optype; $i++) {
23 $optype_enum{$optype[$i]} = $i;
26 # Following is SVf_POK|SVp_POK
27 # XXX Shouldn't be hardwired
28 sub POK () { SVf_POK|SVp_POK }
30 # Following is SVf_IOK|SVp_IOK
31 # XXX Shouldn't be hardwired
32 sub IOK () { SVf_IOK|SVp_IOK }
34 my ($verbose, $module_only, $no_assemble, $debug_bc, $debug_cv);
37 # Optimisation options. On the command line, use hyphens instead of
38 # underscores for compatibility with gcc-style options. We use
39 # underscores here because they are OK in (strict) barewords.
40 my ($strip_syntree, $compress_nullops, $omit_seq, $bypass_nullops);
41 my %optimise = (strip_syntax_tree => \$strip_syntree,
42 compress_nullops => \$compress_nullops,
43 omit_sequence_numbers => \$omit_seq,
44 bypass_nullops => \$bypass_nullops);
47 my %symtable; # maps object addresses to object indices.
48 # Filled in at allocation (newsv/newop) time.
49 my %saved; # maps object addresses (for SVish classes) to "saved yet?"
50 # flag. Set at FOO::bytecode time usually by SV::bytecode.
51 # Manipulated via saved(), mark_saved(), unmark_saved().
53 my $svix = -1; # we keep track of when the sv register contains an element
54 # of the object table to avoid unnecessary repeated
55 # consecutive ldsv instructions.
56 my $opix = -1; # Ditto for the op register.
97 return cstring($str . "\0");
103 sub saved { $saved{${$_[0]}} }
104 sub mark_saved { $saved{${$_[0]}} = 1 }
105 sub unmark_saved { $saved{${$_[0]}} = 0 }
107 sub debug { $debug_bc = shift }
111 warn sprintf("bytecode save method for %s (0x%x) not yet implemented\n",
116 # objix may stomp on the op register (for op objects)
117 # or the sv register (for SV objects)
119 sub B::OBJECT::objix {
121 my $ix = $symtable{$$obj};
125 $obj->newix($nextix);
126 return $symtable{$$obj} = $nextix++;
132 printf "newsv %d\t# %s\n", $sv->FLAGS & 0xf, class($sv);
138 my $gvname = $gv->NAME;
139 my $name = cstring($gv->STASH->NAME . "::" . $gvname);
140 print "gv_fetchpv $name\n";
146 my $name = $hv->NAME;
149 printf "gv_stashpv %s\n", cstring($name);
152 # It's an ordinary HV. Fall back to ordinary newix method
153 $hv->B::SV::newix($ix);
157 sub B::SPECIAL::newix {
159 # Special case. $$sv is not the address of the SV but an
160 # index into svspecialsv_list.
161 printf "ldspecsv $$sv\t# %s\n", $specialsv_name[$$sv];
167 my $class = class($op);
168 my $typenum = $optype_enum{$class};
169 croak "OP::newix: can't understand class $class" unless defined($typenum);
170 print "newop $typenum\t# $class\n";
174 sub B::OP::walkoptree_debug {
176 warn(sprintf("walkoptree: %s\n", peekop($op)));
179 sub B::OP::bytecode {
181 my $next = $op->next;
183 my $sibix = $op->sibling->objix;
185 my $type = $op->type;
187 if ($bypass_nullops) {
188 $next = $next->next while $$next && $next->type == 0;
190 $nextix = $next->objix;
192 printf "# %s\n", peekop($op) if $debug_bc;
194 print "op_next $nextix\n";
195 print "op_sibling $sibix\n" unless $strip_syntree;
196 printf "op_type %s\t# %d\n", "pp_" . $op->name, $type;
197 printf("op_seq %d\n", $op->seq) unless $omit_seq;
198 if ($type || !$compress_nullops) {
199 printf "op_targ %d\nop_flags 0x%x\nop_private 0x%x\n",
200 $op->targ, $op->flags, $op->private;
204 sub B::UNOP::bytecode {
206 my $firstix = $op->first->objix;
207 $op->B::OP::bytecode;
208 if (($op->type || !$compress_nullops) && !$strip_syntree) {
209 print "op_first $firstix\n";
213 sub B::LOGOP::bytecode {
215 my $otherix = $op->other->objix;
216 $op->B::UNOP::bytecode;
217 print "op_other $otherix\n";
220 sub B::SVOP::bytecode {
223 my $svix = $sv->objix;
224 $op->B::OP::bytecode;
225 print "op_sv $svix\n";
229 sub B::PADOP::bytecode {
231 my $padix = $op->padix;
232 $op->B::OP::bytecode;
233 print "op_padix $padix\n";
236 sub B::PVOP::bytecode {
239 $op->B::OP::bytecode;
241 # This would be easy except that OP_TRANS uses a PVOP to store an
242 # endian-dependent array of 256 shorts instead of a plain string.
244 if ($op->name eq "trans") {
245 my @shorts = unpack("s256", $pv); # assembler handles endianness
246 print "op_pv_tr ", join(",", @shorts), "\n";
248 printf "newpv %s\nop_pv\n", pvstring($pv);
252 sub B::BINOP::bytecode {
254 my $lastix = $op->last->objix;
255 $op->B::UNOP::bytecode;
256 if (($op->type || !$compress_nullops) && !$strip_syntree) {
257 print "op_last $lastix\n";
261 sub B::LISTOP::bytecode {
263 my $children = $op->children;
264 $op->B::BINOP::bytecode;
265 if (($op->type || !$compress_nullops) && !$strip_syntree) {
266 print "op_children $children\n";
270 sub B::LOOP::bytecode {
272 my $redoopix = $op->redoop->objix;
273 my $nextopix = $op->nextop->objix;
274 my $lastopix = $op->lastop->objix;
275 $op->B::LISTOP::bytecode;
276 print "op_redoop $redoopix\nop_nextop $nextopix\nop_lastop $lastopix\n";
279 sub B::COP::bytecode {
281 my $stash = $op->stash;
282 my $stashix = $stash->objix;
283 my $filegv = $op->filegv;
284 my $filegvix = $filegv->objix;
285 my $line = $op->line;
286 my $warnings = $op->warnings;
287 my $warningsix = $warnings->objix;
289 printf "# line %s:%d\n", $filegv->SV->PV, $line;
291 $op->B::OP::bytecode;
292 printf <<"EOT", pvstring($op->label), $op->cop_seq, $op->arybase;
300 cop_warnings $warningsix
306 sub B::PMOP::bytecode {
308 my $replroot = $op->pmreplroot;
309 my $replrootix = $replroot->objix;
310 my $replstartix = $op->pmreplstart->objix;
311 my $opname = $op->name;
312 # pmnext is corrupt in some PMOPs (see misc.t for example)
313 #my $pmnextix = $op->pmnext->objix;
316 # OP_PUSHRE (a mutated version of OP_MATCH for the regexp
317 # argument to a split) stores a GV in op_pmreplroot instead
318 # of a substitution syntax tree. We don't want to walk that...
319 if ($opname eq "pushre") {
322 walkoptree($replroot, "bytecode");
325 $op->B::LISTOP::bytecode;
326 if ($opname eq "pushre") {
327 printf "op_pmreplrootgv $replrootix\n";
329 print "op_pmreplroot $replrootix\nop_pmreplstart $replstartix\n";
331 my $re = pvstring($op->precomp);
332 # op_pmnext omitted since a perl bug means it's sometime corrupt
333 printf <<"EOT", $op->pmflags, $op->pmpermflags;
341 sub B::SV::bytecode {
343 return if saved($sv);
345 my $refcnt = $sv->REFCNT;
346 my $flags = sprintf("0x%x", $sv->FLAGS);
348 print "sv_refcnt $refcnt\nsv_flags $flags\n";
352 sub B::PV::bytecode {
354 return if saved($sv);
355 $sv->B::SV::bytecode;
356 printf("newpv %s\nxpv\n", pvstring($sv->PV)) if $sv->FLAGS & POK;
359 sub B::IV::bytecode {
361 return if saved($sv);
363 $sv->B::SV::bytecode;
364 printf "%s $iv\n", $sv->needs64bits ? "xiv64" : "xiv32";
367 sub B::NV::bytecode {
369 return if saved($sv);
370 $sv->B::SV::bytecode;
371 printf "xnv %s\n", $sv->NVX;
374 sub B::RV::bytecode {
376 return if saved($sv);
378 my $rvix = $rv->objix;
380 $sv->B::SV::bytecode;
384 sub B::PVIV::bytecode {
386 return if saved($sv);
388 $sv->B::PV::bytecode;
389 printf "%s $iv\n", $sv->needs64bits ? "xiv64" : "xiv32";
392 sub B::PVNV::bytecode {
394 my $flag = shift || 0;
395 # The $flag argument is passed through PVMG::bytecode by BM::bytecode
396 # and AV::bytecode and indicates special handling. $flag = 1 is used by
397 # BM::bytecode and means that we should ensure we save the whole B-M
398 # table. It consists of 257 bytes (256 char array plus a final \0)
399 # which follow the ordinary PV+\0 and the 257 bytes are *not* reflected
400 # in SvCUR. $flag = 2 is used by AV::bytecode and means that we only
401 # call SV::bytecode instead of saving PV and calling NV::bytecode since
402 # PV/NV/IV stuff is different for AVs.
403 return if saved($sv);
405 $sv->B::SV::bytecode;
408 $sv->B::IV::bytecode;
409 printf "xnv %s\n", $sv->NVX;
411 $pv .= "\0" . $sv->TABLE;
412 printf "newpv %s\npv_cur %d\nxpv\n", pvstring($pv),length($pv)-257;
414 printf("newpv %s\nxpv\n", pvstring($pv)) if $sv->FLAGS & POK;
419 sub B::PVMG::bytecode {
420 my ($sv, $flag) = @_;
421 # See B::PVNV::bytecode for an explanation of $flag.
422 return if saved($sv);
423 # XXX We assume SvSTASH is already saved and don't save it later ourselves
424 my $stashix = $sv->SvSTASH->objix;
425 my @mgchain = $sv->MAGIC;
428 # We need to traverse the magic chain and get objix for each OBJ
429 # field *before* we do B::PVNV::bytecode since objix overwrites
430 # the sv register. However, we need to write the magic-saving
431 # bytecode *after* B::PVNV::bytecode since sv isn't initialised
432 # to refer to $sv until then.
434 @mgobjix = map($_->OBJ->objix, @mgchain);
435 $sv->B::PVNV::bytecode($flag);
436 print "xmg_stash $stashix\n";
437 foreach $mg (@mgchain) {
438 printf "sv_magic %s\nmg_obj %d\nnewpv %s\nmg_pv\n",
439 cstring($mg->TYPE), shift(@mgobjix), pvstring($mg->PTR);
443 sub B::PVLV::bytecode {
445 return if saved($sv);
446 $sv->B::PVMG::bytecode;
447 printf <<'EOT', $sv->TARGOFF, $sv->TARGLEN, cstring($sv->TYPE);
454 sub B::BM::bytecode {
456 return if saved($sv);
457 # See PVNV::bytecode for an explanation of what the argument does
458 $sv->B::PVMG::bytecode(1);
459 printf "xbm_useful %d\nxbm_previous %d\nxbm_rare %d\n",
460 $sv->USEFUL, $sv->PREVIOUS, $sv->RARE;
463 sub B::GV::bytecode {
465 return if saved($gv);
468 my $gvname = $gv->NAME;
469 my $name = cstring($gv->STASH->NAME . "::" . $gvname);
471 my $egvix = $egv->objix;
473 printf <<"EOT", $gv->FLAGS, $gv->GvFLAGS, $gv->LINE, cstring($gv->FILE);
479 my $refcnt = $gv->REFCNT;
480 printf("sv_refcnt_add %d\n", $refcnt - 1) if $refcnt > 1;
481 my $gvrefcnt = $gv->GvREFCNT;
482 printf("gp_refcnt_add %d\n", $gvrefcnt - 1) if $gvrefcnt > 1;
483 if ($gvrefcnt > 1 && $ix != $egvix) {
484 print "gp_share $egvix\n";
486 if ($gvname !~ /^([^A-Za-z]|STDIN|STDOUT|STDERR|ARGV|SIG|ENV)$/) {
488 my @subfield_names = qw(SV AV HV CV FORM IO);
489 my @subfields = map($gv->$_(), @subfield_names);
490 my @ixes = map($_->objix, @subfields);
491 # Reset sv register for $gv
493 for ($i = 0; $i < @ixes; $i++) {
494 printf "gp_%s %d\n", lc($subfield_names[$i]), $ixes[$i];
496 # Now save all the subfields
498 foreach $sv (@subfields) {
505 sub B::HV::bytecode {
507 return if saved($hv);
509 my $name = $hv->NAME;
512 # It's an ordinary HV. Stashes have NAME set and need no further
513 # saving beyond the gv_stashpv that $hv->objix already ensures.
514 my @contents = $hv->ARRAY;
516 for ($i = 1; $i < @contents; $i += 2) {
517 push(@ixes, $contents[$i]->objix);
519 for ($i = 1; $i < @contents; $i += 2) {
520 $contents[$i]->bytecode;
523 for ($i = 0; $i < @contents; $i += 2) {
524 printf("newpv %s\nhv_store %d\n",
525 pvstring($contents[$i]), $ixes[$i / 2]);
527 printf "sv_refcnt %d\nsv_flags 0x%x\n", $hv->REFCNT, $hv->FLAGS;
531 sub B::AV::bytecode {
533 return if saved($av);
535 my $fill = $av->FILL;
540 @ixes = map($_->objix, @array);
542 foreach $sv (@array) {
546 # See PVNV::bytecode for the meaning of the flag argument of 2.
547 $av->B::PVMG::bytecode(2);
548 # Recover sv register and set AvMAX and AvFILL to -1 (since we
549 # create an AV with NEWSV and SvUPGRADE rather than doing newAV
550 # which is what sets AvMAX and AvFILL.
552 printf "xav_flags 0x%x\nxav_max -1\nxav_fill -1\n", $av->AvFLAGS;
555 foreach $elix (@ixes) {
556 print "av_push $elix\n";
560 print "av_extend $max\n";
565 sub B::CV::bytecode {
567 return if saved($cv);
569 $cv->B::PVMG::bytecode;
571 my @subfield_names = qw(ROOT START STASH GV PADLIST OUTSIDE);
572 my @subfields = map($cv->$_(), @subfield_names);
573 my @ixes = map($_->objix, @subfields);
574 # Save OP tree from CvROOT (first element of @subfields)
575 my $root = shift @subfields;
577 walkoptree($root, "bytecode");
579 # Reset sv register for $cv (since above ->objix calls stomped on it)
581 for ($i = 0; $i < @ixes; $i++) {
582 printf "xcv_%s %d\n", lc($subfield_names[$i]), $ixes[$i];
584 printf "xcv_depth %d\nxcv_flags 0x%x\n", $cv->DEPTH, $cv->FLAGS;
585 # Now save all the subfields (except for CvROOT which was handled
586 # above) and CvSTART (now the initial element of @subfields).
587 shift @subfields; # bye-bye CvSTART
589 foreach $sv (@subfields) {
594 sub B::IO::bytecode {
596 return if saved($io);
598 my $top_gv = $io->TOP_GV;
599 my $top_gvix = $top_gv->objix;
600 my $fmt_gv = $io->FMT_GV;
601 my $fmt_gvix = $fmt_gv->objix;
602 my $bottom_gv = $io->BOTTOM_GV;
603 my $bottom_gvix = $bottom_gv->objix;
605 $io->B::PVMG::bytecode;
607 print "xio_top_gv $top_gvix\n";
608 print "xio_fmt_gv $fmt_gvix\n";
609 print "xio_bottom_gv $bottom_gvix\n";
611 foreach $field (qw(TOP_NAME FMT_NAME BOTTOM_NAME)) {
612 printf "newpv %s\nxio_%s\n", pvstring($io->$field()), lc($field);
614 foreach $field (qw(LINES PAGE PAGE_LEN LINES_LEFT SUBPROCESS)) {
615 printf "xio_%s %d\n", lc($field), $io->$field();
617 printf "xio_type %s\nxio_flags 0x%x\n", cstring($io->IoTYPE), $io->IoFLAGS;
620 $bottom_gv->bytecode;
623 sub B::SPECIAL::bytecode {
624 # nothing extra needs doing
627 sub bytecompile_object {
630 svref_2object($sv)->bytecode;
634 sub B::GV::bytecodecv {
637 if ($$cv && !saved($cv)) {
639 warn sprintf("saving extra CV &%s::%s (0x%x) from GV 0x%x\n",
640 $gv->STASH->NAME, $gv->NAME, $$cv, $$gv);
646 sub bytecompile_main {
647 my $curpad = (comppadlist->ARRAY)[1];
648 my $curpadix = $curpad->objix;
650 walkoptree(main_root, "bytecode");
651 warn "done main program, now walking symbol table\n" if $debug_bc;
652 my ($pack, %exclude);
653 foreach $pack (qw(B O AutoLoader DynaLoader Config DB VMS strict vars
654 FileHandle Exporter Carp UNIVERSAL IO Fcntl Symbol
655 SelectSaver blib Cwd))
657 $exclude{$pack."::"} = 1;
659 no strict qw(vars refs);
660 walksymtable(\%{"main::"}, "bytecodecv", sub {
661 warn "considering $_[0]\n" if $debug_bc;
662 return !defined($exclude{$_[0]});
665 printf "main_root %d\n", main_root->objix;
666 printf "main_start %d\n", main_start->objix;
667 printf "curpad $curpadix\n";
668 # XXX Do min_intro_pending and max_intro_pending matter?
672 sub prepare_assemble {
673 my $newfh = IO::File->new_tmpfile;
681 seek($fh, 0, 0); # rewind the temporary file
682 assemble_fh($fh, sub { print OUT @_ });
687 my ($option, $opt, $arg);
688 open(OUT, ">&STDOUT");
692 while ($option = shift @options) {
693 if ($option =~ /^-(.)(.*)/) {
697 unshift @options, $option;
700 if ($opt eq "-" && $arg eq "-") {
703 } elsif ($opt eq "o") {
704 $arg ||= shift @options;
705 open(OUT, ">$arg") or return "$arg: $!\n";
707 } elsif ($opt eq "D") {
708 $arg ||= shift @options;
709 foreach $arg (split(//, $arg)) {
713 } elsif ($arg eq "o") {
715 } elsif ($arg eq "a") {
716 B::Assembler::debug(1);
717 } elsif ($arg eq "C") {
721 } elsif ($opt eq "v") {
723 } elsif ($opt eq "m") {
725 } elsif ($opt eq "S") {
727 } elsif ($opt eq "f") {
728 $arg ||= shift @options;
729 my $value = $arg !~ s/^no-//;
731 my $ref = $optimise{$arg};
735 warn qq(ignoring unknown optimisation option "$arg"\n);
737 } elsif ($opt eq "O") {
738 $arg = 1 if $arg eq "";
740 foreach $ref (values %optimise) {
750 $compress_nullops = 1;
759 $newfh = prepare_assemble() unless $no_assemble;
760 foreach $objname (@options) {
761 eval "bytecompile_object(\\$objname)";
763 do_assemble($newfh) unless $no_assemble;
768 $newfh = prepare_assemble() unless $no_assemble;
770 do_assemble($newfh) unless $no_assemble;
781 B::Bytecode - Perl compiler's bytecode backend
785 perl -MO=Bytecode[,OPTIONS] foo.pl
789 This compiler backend takes Perl source and generates a
790 platform-independent bytecode encapsulating code to load the
791 internal structures perl uses to run your program. When the
792 generated bytecode is loaded in, your program is ready to run,
793 reducing the time which perl would have taken to load and parse
794 your program into its internal semi-compiled form. That means that
795 compiling with this backend will not help improve the runtime
796 execution speed of your program but may improve the start-up time.
797 Depending on the environment in which your program runs this may
798 or may not be a help.
800 The resulting bytecode can be run with a special byteperl executable
801 or (for non-main programs) be loaded via the C<byteload_fh> function
806 If there are any non-option arguments, they are taken to be names of
807 objects to be saved (probably doesn't work properly yet). Without
808 extra arguments, it saves the main program.
814 Output to filename instead of STDOUT.
818 Force end of options.
822 Force optimisations on or off one at a time. Each can be preceded
823 by B<no-> to turn the option off (e.g. B<-fno-compress-nullops>).
825 =item B<-fcompress-nullops>
827 Only fills in the necessary fields of ops which have
828 been optimised away by perl's internal compiler.
830 =item B<-fomit-sequence-numbers>
832 Leaves out code to fill in the op_seq field of all ops
833 which is only used by perl's internal compiler.
835 =item B<-fbypass-nullops>
837 If op->op_next ever points to a NULLOP, replaces the op_next field
838 with the first non-NULLOP in the path of execution.
840 =item B<-fstrip-syntax-tree>
842 Leaves out code to fill in the pointers which link the internal syntax
843 tree together. They're not needed at run-time but leaving them out
844 will make it impossible to recompile or disassemble the resulting
845 program. It will also stop C<goto label> statements from working.
849 Optimisation level (n = 0, 1, 2, ...). B<-O> means B<-O1>.
850 B<-O1> sets B<-fcompress-nullops> B<-fomit-sequence numbers>.
851 B<-O6> adds B<-fstrip-syntax-tree>.
855 Debug options (concatenated or separate flags like C<perl -D>).
859 Prints each OP as it's processed.
863 Print debugging information about bytecompiler progress.
867 Tells the (bytecode) assembler to include source assembler lines
868 in its output as bytecode comments.
872 Prints each CV taken from the final symbol tree walk.
876 Output (bytecode) assembler source rather than piping it
877 through the assembler and outputting bytecode.
881 Compile as a module rather than a standalone program. Currently this
882 just means that the bytecodes for initialising C<main_start>,
883 C<main_root> and C<curpad> are omitted.
889 perl -MO=Bytecode,-O6,-o,foo.plc foo.pl
891 perl -MO=Bytecode,-S foo.pl > foo.S
892 assemble foo.S > foo.plc
894 Note that C<assemble> lives in the C<B> subdirectory of your perl
895 library directory. The utility called perlcc may also be used to
896 help make use of this compiler.
898 perl -MO=Bytecode,-m,-oFoo.pmc Foo.pm
902 Plenty. Current status: experimental.
906 Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>