BOOT:
{
- sub_op_keyword k;
- k.name = "reftype";
- k.len = sizeof("reftype")-1;
- k.pp = scalar_util_reftype;
- k.check = 0;
- k.ud = NULL;
- sub_op_register(aTHX_ &k);
+ sub_op_config_t c;
+ c.name = "reftype";
+ c.len = sizeof("reftype")-1;
+ c.pp = scalar_util_reftype;
+ c.check = 0;
+ c.ud = NULL;
+ sub_op_register(aTHX_ &c);
}
In your Perl module file :
...
);
+=head1 DESCRIPTION
+
+This module provides a C and Perl API for replacing subroutine calls by custom opcodes.
+This has two main advantages :
+
+=over 4
+
+=item *
+
+it gets rid of the overhead of a normal subroutine call ;
+
+=item *
+
+there's no symbol table entry defined for the subroutine.
+
+=back
+
+Subroutine calls with and without parenthesis are handled.
+Ampersand calls are B<not> replaced, and as such will still allow to call a subroutine with same name defined earlier.
+This may or may not be considered as a bug, but it gives the same semantics as Perl keywords, so I believe it's reasonable.
+
+When L<B> and L<B::Deparse> are loaded, they get automatically monkeypatched so that introspecting modules like L<B::Concise> and L<B::Deparse> still produce a valid output.
+
=cut
+use Scalar::Util;
+
use B::Hooks::EndOfScope;
use Variable::Magic 0.08;
my $pkg = $data->{pkg};
my $fqn = join '::', $pkg, $name;
- _incoming($name, $pkg);
-
no strict 'refs';
*$fqn = $placeholder unless exists &$fqn;
},
);
+sub _tag {
+ my ($pkg, $name) = @_;
+
+ my $fqn = join '::', $pkg, $name;
+
+ return {
+ proto => prototype($fqn),
+ };
+}
+
sub _map {
my ($pkg) = @_;
sub _cast {
my ($pkg, $name) = @_;
- no strict 'refs';
- Variable::Magic::cast(%{"${pkg}::"}, $sw, $pkg, { $name => 1 });
+ my $map = { $name => _tag(@_) };
+
+ {
+ no strict 'refs';
+ Variable::Magic::cast(%{"${pkg}::"}, $sw, $pkg, $map);
+ }
+
+ return $map;
}
sub _dispell {
Variable::Magic::dispell(%{"${pkg}::"}, $sw);
}
+=head1 C API
+
+=head2 C<sub_op_config_t>
+
+A typedef'd struct that configures how L<Sub::Op> should handle a given subroutine name.
+It has the following members :
+
+=over 4
+
+=item *
+
+C<const char *name>
+
+The name of the subroutine you want to replace.
+Allowed to be static.
+
+=item *
+
+C<STRLEN len>
+
+C<name>'s length, in bytes.
+
+=item *
+
+C<Perl_ppaddr_t pp>
+
+The pp function that will be called instead of the subroutine.
+C<Perl_ppaddr_t> is a typedef'd function pointer defined by perl as :
+
+ typedef OP *(*Perl_ppaddr_t)(pTHX);
+
+=item *
+
+C<sub_op_check_t check>
+
+An optional callback that will be called each time a call to C<name> is replaced.
+You can use it to attach extra info to those ops (e.g. with a pointer table) or to perform more optimizations to the optree.
+C<sub_op_check_t> is a typedef'd function pointer defined by :
+
+ typedef OP *(*sub_op_check_t)(pTHX_ OP *, void *);
+
+=item *
+
+C<void *ud>
+
+An optional user data passed to the C<check> callback.
+
+=back
+
+=head2 C<void sub_op_register(pTHX_ const sub_op_config_t *c)>
+
+Registers a name and its configuration into L<Sub::Op>.
+The caller is responsible for allocating and freeing the C<sub_op_config_t> object.
+No pointer to it or to its members is kept.
+
+=head1 PERL API
+
+=head2 C<enable $name, [ $pkg ]>
+
+Enable the replacement with a custom opcode of calls to the C<$name> subroutine of the C<$pkg> package in the current lexical scope.
+A pp callback must have been registered for C<$name> by calling the C function C<sub_op_register> in the XS section of your module.
+
+When C<$pkg> is not set, it defaults to the caller package.
+
+=cut
+
sub enable {
my $name = shift;
my $pkg = @_ > 0 ? $_[0] : caller;
- my $fqn = "${pkg}::$name";
-
my $map = _map($pkg);
if (defined $map) {
- $map->{$name} = 1;
+ $map->{$name} = _tag($pkg, $name);
} else {
- _cast($pkg, $name);
+ $map = _cast($pkg, $name);
+ }
+
+ my $proto = $map->{$name}->{proto};
+ if (defined $proto) {
+ no strict 'refs';
+ Scalar::Util::set_prototype(\&{"${pkg}::$name"}, undef);
}
$^H |= 0x00020000;
return;
}
+=head2 C<disable $name, [ $pkg ]>
+
+Disable the replacement for calls to C<$name> in the package C<$pkg>.
+
+When C<$pkg> is not set, it defaults to the caller package.
+
+=cut
+
sub disable {
my $name = shift;
my $pkg = @_ > 0 ? $_[0] : caller;
- my $fqn = "${pkg}::$name";
-
my $map = _map($pkg);
if (defined $map) {
+ my $proto = $map->{$name}->{proto};
+ if (defined $proto) {
+ no strict 'refs';
+ Scalar::Util::set_prototype(\&{"${pkg}::$name"}, $proto);
+ }
+
delete $map->{$name};
unless (keys %$map) {
_dispell($pkg);
$B_OP_inject{can} = sub {
my ($obj, $meth) = @_;
if ($meth eq 'first') {
- return undef unless defined _custom_name($obj);
+ return undef unless $obj->isa('B::UNOP') or defined _custom_name($obj);
}
$obj->SUPER::can($meth);
};
BEGIN { _monkeypatch() }
+=head1 EXAMPLES
+
+See the F<t/Sub-Op-LexicalSub> directory that implements a complete example.
+
=head1 DEPENDENCIES
L<perl> 5.10.
projects / perl / modules / Sub-Op.git / blobdiff