our $VERSION = '1.02_01';
@EXPORT_OK = qw(find_leaders);
use B
qw(peekop walkoptree walkoptree_exec
main_root main_start svref_2object
OPf_SPECIAL OPf_STACKED );
use B
::Concise
qw(concise_cv concise_main set_style_standard);
delete $$bblock{$_} if( $leader == 0);
mark_leader
($start) if ( ref $start ne "B::NULL" );
walkoptree
($root, "mark_if_leader") if ((ref $root) ne "B::NULL") ;
my ($op, $lastop, $leader, $bb);
walkoptree
($root, "mark_if_leader");
my @leaders = values %$bblock;
while ($leader = shift @leaders) {
while ($$op && !exists($bblock->{$$op})) {
$bblock->{$$op} = $leader;
push(@bblock_ends, [$leader, $lastop]);
foreach $bb (@bblock_ends) {
($leader, $lastop) = @
$bb;
printf "%s .. %s\n", peekop
($leader), peekop
($lastop);
for ($op = $leader; $$op != $$lastop; $op = $op->next) {
printf " %s\n", peekop
($op);
printf " %s\n", peekop
($lastop);
my $cv = svref_2object
($cvref);
walk_bblocks
($cv->ROOT, $cv->START);
sub B
::OP
::mark_if_leader
{}
sub B
::COP
::mark_if_leader
{
sub B
::LOOP
::mark_if_leader
{
mark_leader
($op->nextop);
mark_leader
($op->redoop);
mark_leader
($op->lastop->next);
sub B
::LOGOP
::mark_if_leader
{
if ($opname eq "entertry") {
mark_leader
($op->other->next);
sub B
::LISTOP
::mark_if_leader
{
$first=$first->next while ($first->name eq "null");
mark_leader
($op->first) unless (exists( $bblock->{$$first}));
if ($op->name eq "sort" and $op->flags & OPf_SPECIAL
and $op->flags & OPf_STACKED
){
my $root=$op->first->sibling->first;
sub B
::PMOP
::mark_if_leader
{
if ($op->name ne "pushre") {
my $replroot = $op->pmreplroot;
mark_leader
($op->pmreplstart);
foreach $objname (@options) {
$objname = "main::$objname" unless $objname =~ /::/;
eval "walk_bblocks_obj(\\&$objname)";
die "walk_bblocks_obj(\\&$objname) failed: $@" if $@
;
set_style_standard
("terse");
eval "concise_cv('exec', \\&$objname)";
die "concise_cv('exec', \\&$objname) failed: $@" if $@
;
walk_bblocks
(main_root
, main_start
);
set_style_standard
("terse");
# Any COP (pp_nextstate) with a non-NULL label
# [The op after a pp_enter] Omit
# [The op after a pp_entersub. Don't count this one.]
# The ops pointed at by nextop, redoop and lastop->op_next of a LOOP
# The ops pointed at by op_next and op_other of a LOGOP, except
# for pp_entertry which has op_next and op_other->op_next
# The op pointed at by op_pmreplstart of a PMOP
# The op pointed at by op_other->op_pmreplstart of pp_substcont?
# [The op after a pp_return] Omit
B::Bblock - Walk basic blocks
perl -MO=Bblock[,OPTIONS] foo.pl
use B::Bblock qw(find_leaders);
my $leaders = find_leaders($root_op, $start_op);
This module is used by the B::CC back end. It walks "basic blocks".
A basic block is a series of operations which is known to execute from
start to finish, with no possibility of branching or halting.
It can be used either stand alone or from inside another program.
Somebody who understands the stand-alone options document them, please.
my $leaders = find_leaders($root_op, $start_op);
Given the root of the op tree and an op from which to start
processing, it will return a hash ref representing all the ops which
The above description may be somewhat wrong.
The values of %$leaders are the op objects themselves. Keys are $$op
Above cribbed from B::CC's comments. What's a $$op address?
Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>