Re: [PATCH] Quieten warnings in Deparse.pm

[p5sagit/p5-mst-13.2.git] / ext / B / B / Bblock.pm

diff --git a/ext/B/B/Bblock.pm b/ext/B/B/Bblock.pm
index cb007ff..624bae4 100644 (file)
--- a/ext/B/B/Bblock.pm
+++ b/ext/B/B/Bblock.pm
@@ -1,10 +1,15 @@
 package B::Bblock;
+
+our $VERSION = '1.00';
+
 use Exporter ();
 @ISA = "Exporter";
 @EXPORT_OK = qw(find_leaders);
 
 use B qw(peekop walkoptree walkoptree_exec
-        main_root main_start svref_2object);
+        main_root main_start svref_2object
+         OPf_SPECIAL OPf_STACKED );
+
 use B::Terse;
 use strict;
 
@@ -18,11 +23,18 @@ sub mark_leader {
     }
 }
 
+sub remove_sortblock{
+    foreach (keys %$bblock){
+        my $leader=$$bblock{$_};       
+       delete $$bblock{$_} if( $leader == 0);   
+    }
+}
 sub find_leaders {
     my ($root, $start) = @_;
     $bblock = {};
-    mark_leader($start);
-    walkoptree($root, "mark_if_leader");
+    mark_leader($start) if ( ref $start ne "B::NULL" );
+    walkoptree($root, "mark_if_leader") if ((ref $root) ne "B::NULL") ;
+    remove_sortblock();
     return $bblock;
 }
 
@@ -81,31 +93,32 @@ sub B::LOOP::mark_if_leader {
 
 sub B::LOGOP::mark_if_leader {
     my $op = shift;
-    my $ppaddr = $op->ppaddr;
+    my $opname = $op->name;
     mark_leader($op->next);
-    if ($ppaddr eq "pp_entertry") {
+    if ($opname eq "entertry") {
        mark_leader($op->other->next);
     } else {
        mark_leader($op->other);
     }
 }
 
-sub B::CONDOP::mark_if_leader {
-    my $op = shift;
-    mark_leader($op->next);
-    mark_leader($op->true);
-    mark_leader($op->false);
-}
-
 sub B::LISTOP::mark_if_leader {
     my $op = shift;
-    mark_leader($op->first);
+    my $first=$op->first;
+    $first=$first->next while ($first->name eq "null");
+    mark_leader($op->first) unless (exists( $bblock->{$$first}));
     mark_leader($op->next);
+    if ($op->name eq "sort" and $op->flags & OPf_SPECIAL
+       and $op->flags & OPf_STACKED){
+        my $root=$op->first->sibling->first;
+        my $leader=$root->first;
+        $bblock->{$$leader} = 0;
+    }
 }
 
 sub B::PMOP::mark_if_leader {
     my $op = shift;
-    if ($op->ppaddr ne "pp_pushre") {
+    if ($op->name ne "pushre") {
        my $replroot = $op->pmreplroot;
        if ($$replroot) {
            mark_leader($replroot);
@@ -119,6 +132,7 @@ sub B::PMOP::mark_if_leader {
 
 sub compile {
     my @options = @_;
+    B::clearsym();
     if (@options) {
        return sub {
            my $objname;
@@ -140,7 +154,6 @@ sub compile {
 #     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 ops pointed at by op_true and op_false of a CONDOP
 #     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
@@ -155,11 +168,47 @@ B::Bblock - Walk basic blocks
 
 =head1 SYNOPSIS
 
-       perl -MO=Bblock[,OPTIONS] foo.pl
+  # External interface
+  perl -MO=Bblock[,OPTIONS] foo.pl
+
+  # Programmatic API
+  use B::Bblock qw(find_leaders);
+  my $leaders = find_leaders($root_op, $start_op);
 
 =head1 DESCRIPTION
 
-See F<ext/B/README>.
+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 possiblity of branching or halting.
+
+It can be used either stand alone or from inside another program.
+
+=for _private
+Somebody who understands the stand-alone options document them, please.
+
+=head2 Functions
+
+=over 4
+
+=item B<find_leaders>
+
+  my $leaders = find_leaders($root_op, $start_op);
+
+Given the root of the op tree and an op from which to start
+processing, it will return a hash ref representing all the ops which
+start a block.
+
+=for _private
+The above description may be somewhat wrong.
+
+The values of %$leaders are the op objects themselves.  Keys are $$op
+addresses.
+
+=for _private
+Above cribbed from B::CC's comments.  What's a $$op address?
+
+=back
+
 
 =head1 AUTHOR