X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FSub%2FOp.pm;h=d8a6b738c7461f856af60f1137ac4ac725f9b9b2;hb=efeaaece7f45dd3c188aca0094d050ea242d4bb6;hp=6459b04c3b64a6977746d416ee9c17cae833da23;hpb=3b39085a294ef16114b0d119dc8ebdecbe87fb51;p=perl%2Fmodules%2FSub-Op.git diff --git a/lib/Sub/Op.pm b/lib/Sub/Op.pm index 6459b04..d8a6b73 100644 --- a/lib/Sub/Op.pm +++ b/lib/Sub/Op.pm @@ -11,7 +11,7 @@ Sub::Op - Install subroutines as opcodes. =head1 VERSION -Version 0.01 +Version 0.02 =cut @@ -20,7 +20,7 @@ our ($VERSION, @ISA); sub dl_load_flags { 0x01 } BEGIN { - $VERSION = '0.01'; + $VERSION = '0.02'; require DynaLoader; push @ISA, 'DynaLoader'; __PACKAGE__->bootstrap($VERSION); @@ -49,13 +49,16 @@ In your XS file : 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; + sub_op_init(&c); + c.name = "reftype"; + c.namelen = sizeof("reftype")-1; + c.proto = "$"; + c.protolen = sizeof("$")-1; + c.pp = scalar_util_reftype; + c.check = 0; + c.ud = NULL; + sub_op_register(aTHX_ &c, 0); } In your Perl module file : @@ -93,8 +96,33 @@ In your F : ... ); +=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 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 and L are loaded, they get automatically monkeypatched so that introspecting modules like L and L still produce a valid output. + =cut +use Scalar::Util; + use B::Hooks::EndOfScope; use Variable::Magic 0.08; @@ -117,13 +145,48 @@ my $sw = Variable::Magic::wizard( my $pkg = $data->{pkg}; my $fqn = join '::', $pkg, $name; - no strict 'refs'; - *$fqn = $placeholder unless exists &$fqn; + { + local $SIG{__WARN__} = sub { + CORE::warn(@_) unless $_[0] =~ /^Constant subroutine.*redefined/; + } if _constant_sub(do { no strict 'refs'; \&$fqn }); + no strict 'refs'; + no warnings qw/prototype redefine/; + *$fqn = $placeholder; + } + + { + my $proto = _get_prototype($name); + no strict 'refs'; + Scalar::Util::set_prototype(\&$fqn, $proto); + } return; }, ); +sub _defined_sub { + my ($fqn) = @_; + my @parts = split /::/, $fqn; + my $name = pop @parts; + my $pkg = ''; + for (@parts) { + $pkg .= $_ . '::'; + return 0 unless do { no strict 'refs'; %$pkg }; + } + return do { no strict 'refs'; defined &{"$pkg$name"} }; +} + +sub _tag { + my ($pkg, $name) = @_; + + my $fqn = join '::', $pkg, $name; + + return { + old => _defined_sub($fqn) ? \&$fqn : undef, + proto => prototype($fqn), + }; +} + sub _map { my ($pkg) = @_; @@ -138,8 +201,14 @@ sub _map { sub _cast { my ($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 $map; } sub _dispell { @@ -149,18 +218,115 @@ sub _dispell { Variable::Magic::dispell(%{"${pkg}::"}, $sw); } +=head1 C API + +=head2 C + +A typedef'd struct that configures how L should handle a given subroutine name. +It has the following members : + +=over 4 + +=item * + +C + +The name of the subroutine you want to replace. +Allowed to be static. + +=item * + +C + +C's length, in bytes. + +=item * + +C + +The prototype you want to apply to the subroutine, or C if none. +Allowed to be static. + +=item * + +C + +C's length, in bytes. + +=item * + +C + +The pp function that will be called instead of the subroutine. +C is a typedef'd function pointer defined by perl as : + + typedef OP *(*Perl_ppaddr_t)(pTHX); + +=item * + +C + +An optional callback that will be called each time a call to C is replaced. +You can use it to attach extra info to those ops (e.g. with a pointer table) or to perform more optimizations to the optree. +C is a typedef'd function pointer defined by : + + typedef OP *(*sub_op_check_t)(pTHX_ OP *, void *); + +=item * + +C + +An optional user data passed to the C callback. + +=back + +=head2 C + +Initializes the fields of the C object. +For future compatibility, it is required to call this function with your config object before storing your actual values. +It will store safe defaults for members you won't set. + +=head2 C + +Registers a name and its configuration into L. +The caller is responsible for allocating and freeing the C object. +No pointer to it or to its members is kept, except if you pass the flag C in which case the configuration object will be stolen to be stored into L's internal datastructure. + +=head2 C + +Deeply clones the specified C object. + +=head2 C + +Free the memory associated with the specified C object. + +=head1 PERL API + +=head2 C + +Enable the replacement with a custom opcode of calls to the C<$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 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); } $^H |= 0x00020000; @@ -171,15 +337,38 @@ sub enable { return; } +=head2 C + +Disable the replacement for calls to C<$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); + my $fqn = join '::', $pkg, $name; + if (defined $map) { + my $tag = $map->{$name}; + + my $old = $tag->{old}; + if (defined $old) { + no strict 'refs'; + no warnings 'redefine'; + *$fqn = $old; + } + + my $proto = $tag->{proto}; + if (defined $proto) { + no strict 'refs'; + Scalar::Util::set_prototype(\&$fqn, $proto); + } + delete $map->{$name}; unless (keys %$map) { _dispell($pkg); @@ -189,91 +378,17 @@ sub disable { return; } -sub _inject { - my ($pkg, $inject) = @_; - - my $stash = do { no strict 'refs'; \%{"${pkg}::"} }; +=head1 EXAMPLES - while (my ($meth, $code) = each %$inject) { - next if exists $stash->{$meth} and (*{$stash->{$meth}}{CODE} // 0) == $code; - no strict 'refs'; - *{"${pkg}::$meth"} = $code; - } -} +See the F directory that implements a complete example. -{ - my $injector; - BEGIN { - $injector = Variable::Magic::wizard( - data => sub { +{ guard => 0, pkg => $_[1], subs => $_[2] } }, - store => sub { - my ($stash, $data, $key) = @_; +=head1 CAVEATS - return if $data->{guard}; - local $data->{guard} = 1; +Preexistent definitions of a sub whose name is handled by L are restored at the end of the lexical scope in which the module is used. +But if you define a sub in the scope of action of L with a name that is currently being replaced, the new declaration will be obliterated at the scope end. - _inject($data->{pkg}, $data->{subs}); - - return; - }, - ); - } - - sub _monkeypatch { - my %B_OP_inject; - - $B_OP_inject{first} = sub { - if (defined _custom_name($_[0])) { - $_[0] = bless $_[0], 'B::UNOP' unless $_[0]->isa('B::UNOP'); - goto $_[0]->can('first') || die 'oops'; - } - require Carp; - Carp::confess('Calling B::OP->first for something that isn\'t a custom op'); - }; - - $B_OP_inject{can} = sub { - my ($obj, $meth) = @_; - if ($meth eq 'first') { - return undef unless defined _custom_name($obj); - } - $obj->SUPER::can($meth); - }; - - if (%B:: and %B::OP:: and *B::OP::type{CODE}) { - _inject('B::OP', \%B_OP_inject); - } else { - Variable::Magic::cast %B::OP::, $injector, 'B::OP', \%B_OP_inject; - } - - my $B_Deparse_inject = { - pp_custom => sub { - my ($self, $op, $cx) = @_; - my $name = _custom_name($op); - die 'unhandled custom op' unless defined $name; - if ($op->flags & B::OPf_STACKED()) { - my $kid = $op->first; - $kid = $kid->first->sibling; # skip ex-list, pushmark - my @exprs; - for (; not B::Deparse::null($kid); $kid = $kid->sibling) { - push @exprs, $self->deparse($kid, 6); - } - my $args = join(", ", @exprs); - return "$name($args)"; - } else { - return $name; - } - }, - }; - - if (%B:: and %B::Deparse:: and *B::Deparse::pp_entersub{CODE}) { - _inject('B::Deparse', $B_Deparse_inject); - } else { - Variable::Magic::cast %B::Deparse::, $injector, 'B::Deparse', $B_Deparse_inject; - } - } -} - -BEGIN { _monkeypatch() } +Function calls without parenthesis inside an C in the scope of the pragma won't be replaced. +I know a few ways of fixing this, but I've not yet decided on which. =head1 DEPENDENCIES @@ -287,6 +402,10 @@ L. L. +L provides a C API to declare XSUBs that effectively call a specific PP function. +Thus, it allows you to write XSUBs with the PP stack conventions used for implementing perl core keywords. +There's no opcode replacement and no parsing hacks. + L. =head1 AUTHOR