NAME

B::Utils - Helper functions for op tree manipulation

SYNOPSIS

use B::Utils;

DESCRIPTION

FUNCTIONS

all_starts

all_roots

Returns a hash of all of the starting ops or root ops of optrees, keyed to subroutine name; the optree for main program is simply keyed to "main".

Note: Certain "dangerous" stashes are not scanned for subroutines: the list of such stashes can be found in @B::Utils::bad_stashes. Feel free to examine and/or modify this to suit your needs. The intention is that a simple program which uses no modules other than B and B::Utils would show no addition symbols.

This does not return the details of ops in anonymous subroutines compiled at compile time. For instance, given

$a = sub { ... };

the subroutine will not appear in the hash. This is just as well, since they're anonymous... If you want to get at them, use...

anon_subs()

This returns an array of hash references. Each element has the keys "start" and "root". These are the starting and root ops of all of the anonymous subroutines in the program.

$op->oldname

Returns the name of the op, even if it is currently optimized to null. This helps you understand the stucture of the op tree.

$op->kids

Returns an array of all this op's non-null children.

$op->parent

Returns the parent node in the op tree, if possible. Currently "possible" means "if the tree has already been optimized"; that is, if we're during a CHECK block. (and hence, if we have valid next pointers.)

In the future, it may be possible to search for the parent before we have the next pointers in place, but it'll take me a while to figure out how to do that.

$op->previous

Like $op->next, but not quite.

EXPORT

None by default.

AUTHOR

Simon Cozens, simon@cpan.org

TODO

I need to add more Fun Things, and possibly clean up some parts where the (previous/parent) algorithm has catastrophic cases, but it's more important to get this out right now than get it right.

SEE ALSO

B, B::Generate.