# walkoptree comes from B.xs
BEGIN {
- $B::VERSION = '1.33';
+ $B::VERSION = '1.52';
@B::EXPORT_OK = ();
# Our BOOT code needs $VERSION set, and will append to @EXPORT_OK.
parents comppadlist sv_undef compile_stats timing_info
begin_av init_av check_av end_av regex_padav dowarn
defstash curstash warnhook diehook inc_gv @optype
- @specialsv_name
- ), $] > 5.009 && 'unitcheck_av');
+ @specialsv_name unitcheck_av safename));
@B::SV::ISA = 'B::OBJECT';
@B::NULL::ISA = 'B::SV';
@B::PVNV::ISA = qw(B::PVIV B::NV);
@B::PVMG::ISA = 'B::PVNV';
@B::REGEXP::ISA = 'B::PVMG' if $] >= 5.011;
-# Change in the inheritance hierarchy post 5.9.0
-@B::PVLV::ISA = $] > 5.009 ? 'B::GV' : 'B::PVMG';
-# BM is eliminated post 5.9.5, but effectively is a specialisation of GV now.
-@B::BM::ISA = $] > 5.009005 ? 'B::GV' : 'B::PVMG';
+@B::INVLIST::ISA = 'B::PV' if $] >= 5.019;
+@B::PVLV::ISA = 'B::GV';
+@B::BM::ISA = 'B::GV';
@B::AV::ISA = 'B::PVMG';
@B::GV::ISA = 'B::PVMG';
@B::HV::ISA = 'B::PVMG';
@B::LOOP::ISA = 'B::LISTOP';
@B::PMOP::ISA = 'B::LISTOP';
@B::COP::ISA = 'B::OP';
+@B::METHOP::ISA = 'B::OP';
@B::SPECIAL::ISA = 'B::OBJECT';
-@B::optype = qw(OP UNOP BINOP LOGOP LISTOP PMOP SVOP PADOP PVOP LOOP COP);
+@B::optype = qw(OP UNOP BINOP LOGOP LISTOP PMOP SVOP PADOP PVOP LOOP COP METHOP);
# bytecode.pl contained the following comment:
# Nullsv *must* come first in the following so that the condition
# ($$sv == 0) can continue to be used to test (sv == Nullsv).
}
sub B::GV::SAFENAME {
- my $name = (shift())->NAME;
+ safename(shift()->NAME);
+}
+
+sub safename {
+ my $name = shift;
# The regex below corresponds to the isCONTROLVAR macro
# from toke.c
- $name =~ s/^([\cA-\cZ\c\\c[\c]\c?\c_\c^])/"^".
- chr( utf8::unicode_to_native( 64 ^ ord($1) ))/e;
+ $name =~ s/^\c?/^?/
+ or $name =~ s/^([\cA-\cZ\c\\c[\c]\c_\c^])/
+ "^" . chr( utf8::unicode_to_native( 64 ^ ord($1) ))/e;
# When we say unicode_to_native we really mean ascii_to_native,
- # which matters iff this is a non-ASCII platform (EBCDIC).
+ # which matters iff this is a non-ASCII platform (EBCDIC). '\c?' would
+ # not have to be special cased, except for non-ASCII.
return $name;
}
my $fullname;
no strict 'refs';
$prefix = '' unless defined $prefix;
- while (($sym, $ref) = each %$symref) {
+ foreach my $sym ( sort keys %$symref ) {
+ $ref= $symref->{$sym};
$fullname = "*main::".$prefix.$sym;
if ($sym =~ /::$/) {
$sym = $prefix . $sym;
=head1 DESCRIPTION
The C<B> module supplies classes which allow a Perl program to delve
-into its own innards. It is the module used to implement the
-"backends" of the Perl compiler. Usage of the compiler does not
+into its own innards. It is the module used to implement the
+"backends" of the Perl compiler. Usage of the compiler does not
require knowledge of this module: see the F<O> module for the
-user-visible part. The C<B> module is of use to those who want to
-write new compiler backends. This documentation assumes that the
+user-visible part. The C<B> module is of use to those who want to
+write new compiler backends. This documentation assumes that the
reader knows a fair amount about perl's internals including such
things as SVs, OPs and the internal symbol table and syntax tree
of a program.
Takes a reference to any Perl value, and turns the referred-to value
into an object in the appropriate B::OP-derived or B::SV-derived
-class. Apart from functions such as C<main_root>, this is the primary
+class. Apart from functions such as C<main_root>, this is the primary
way to get an initial "handle" on an internal perl data structure
which can then be followed with the other access methods.
The returned object will only be valid as long as the underlying OPs
-and SVs continue to exist. Do not attempt to use the object after the
+and SVs continue to exist. Do not attempt to use the object after the
underlying structures are freed.
=item amagic_generation
Returns the SV object corresponding to the C variable C<amagic_generation>.
+As of Perl 5.18, this is just an alias to C<PL_na>, so its value is
+meaningless.
=item init_av
=item comppadlist
-Returns the AV object (i.e. in class B::AV) of the global comppadlist.
+Returns the PADLIST object (i.e. in class B::PADLIST) of the global
+comppadlist. In Perl 5.16 and earlier it returns an AV object (class
+B::AV).
=item regex_padav
walksymtable(\%CGI::, 'print_subs',
sub { $_[0] eq 'CGI::Util::' }, 'CGI::');
-print_subs() is a B::GV method you have declared. Also see L<"B::GV
+print_subs() is a B::GV method you have declared. Also see L<"B::GV
Methods">, below.
=back
=item walkoptree(OP, METHOD)
Does a tree-walk of the syntax tree based at OP and calls METHOD on
-each op it visits. Each node is visited before its children. If
+each op it visits. Each node is visited before its children. If
C<walkoptree_debug> (see below) has been called to turn debugging on then
the method C<walkoptree_debug> is called on each op before METHOD is
called.
=item walkoptree_debug(DEBUG)
-Returns the current debugging flag for C<walkoptree>. If the optional
-DEBUG argument is non-zero, it sets the debugging flag to that. See
+Returns the current debugging flag for C<walkoptree>. If the optional
+DEBUG argument is non-zero, it sets the debugging flag to that. See
the description of C<walkoptree> above for what the debugging flag
does.
=item minus_c
-Does the equivalent of the C<-c> command-line option. Obviously, this
+Does the equivalent of the C<-c> command-line option. Obviously, this
is only useful in a BEGIN block or else the flag is set too late.
=item cstring(STR)
Returns a double-quote-surrounded escaped version of STR which can
be used as a string in Perl source code.
+=item safename(STR)
+
+This function returns the string with the first character modified if it
+is a control character. It converts it to ^X format first, so that "\cG"
+becomes "^G". This is used internally by L<B::GV::SAFENAME|/SAFENAME>, but
+you can call it directly.
+
=item class(OBJ)
Returns the class of an object without the part of the classname
-preceding the first C<"::">. This is used to turn C<"B::UNOP"> into
+preceding the first C<"::">. This is used to turn C<"B::UNOP"> into
C<"UNOP"> for example.
=item threadsv_names
-In a perl compiled for threads, this returns a list of the special
-per-thread threadsv variables.
+This used to provide support for the old 5.005 threading module. It now
+does nothing.
=back
The C structures used by Perl's internals to hold SV and OP
information (PVIV, AV, HV, ..., OP, SVOP, UNOP, ...) are modelled on a
class hierarchy and the C<B> module gives access to them via a true
-object hierarchy. Structure fields which point to other objects
+object hierarchy. Structure fields which point to other objects
(whether types of SV or types of OP) are represented by the C<B>
module as Perl objects of the appropriate class.
these structures.
Note that all access is read-only. You cannot modify the internals by
-using this module. Also, note that the B::OP and B::SV objects created
+using this module. Also, note that the B::OP and B::SV objects created
by this module are only valid for as long as the underlying objects
exist; their creation doesn't increase the reference counts of the
-underlying objects. Trying to access the fields of a freed object will
+underlying objects. Trying to access the fields of a freed object will
give incomprehensible results, or worse.
=head2 SV-RELATED CLASSES
B::IV, B::NV, B::RV, B::PV, B::PVIV, B::PVNV, B::PVMG, B::BM (5.9.5 and
-earlier), B::PVLV, B::AV, B::HV, B::CV, B::GV, B::FM, B::IO. These classes
+earlier), B::PVLV, B::AV, B::HV, B::CV, B::GV, B::FM, B::IO. These classes
correspond in the obvious way to the underlying C structures of similar names.
-The inheritance hierarchy mimics the underlying C "inheritance". For the
+The inheritance hierarchy mimics the underlying C "inheritance". For the
5.10.x branch, (I<ie> 5.10.0, 5.10.1 I<etc>) this is:
B::SV
Access methods correspond to the underlying C macros for field access,
usually with the leading "class indication" prefix removed (Sv, Av,
-Hv, ...). The leading prefix is only left in cases where its removal
-would cause a clash in method name. For example, C<GvREFCNT> stays
+Hv, ...). The leading prefix is only left in cases where its removal
+would cause a clash in method name. For example, C<GvREFCNT> stays
as-is since its abbreviation would clash with the "superclass" method
C<REFCNT> (corresponding to the C function C<SvREFCNT>).
=item object_2svref
Returns a reference to the regular scalar corresponding to this
-B::SV object. In other words, this method is the inverse operation
-to the svref_2object() subroutine. This scalar and other data it points
+B::SV object. In other words, this method is the inverse operation
+to the svref_2object() subroutine. This scalar and other data it points
at should be considered read-only: modifying them is neither safe nor
guaranteed to have a sensible effect.
=item IV
Returns the value of the IV, I<interpreted as
-a signed integer>. This will be misleading
-if C<FLAGS & SVf_IVisUV>. Perhaps you want the
+a signed integer>. This will be misleading
+if C<FLAGS & SVf_IVisUV>. Perhaps you want the
C<int_value> method instead?
=item IVX
=item PV
-This method is the one you usually want. It constructs a
+This method is the one you usually want. It constructs a
string using the length and offset information in the struct:
for ordinary scalars it will return the string that you'd see
from Perl, even if it contains null characters.
=item PVX
-This method is less often useful. It assumes that the string
+This method is less often useful. It assumes that the string
stored in the struct is null-terminated, and disregards the
length information.
It is the appropriate method to use if you need to get the name
-of a lexical variable from a padname array. Lexical variable names
+of a lexical variable from a padname array. Lexical variable names
are always stored with a null terminator, and the length field
(CUR) is overloaded for other purposes and can't be relied on here.
=item FLAGS
+=item GPFLAGS
+
+This last one is present only in perl 5.22.0 and higher.
+
=back
=head2 B::IO Methods
=item IoFLAGS
-See F<perliol.h>.
-
=item IsSTD
Takes one argument ( 'stdin' | 'stdout' | 'stderr' ) and returns true
=item AvFLAGS
-This method returns the AV specific flags. In Perl 5.9 these are now stored
+This method returns the AV specific
+flags. In Perl 5.9 these are now stored
in with the main SV flags, so this method is no longer present.
=back
=item PADLIST
+Returns a B::PADLIST object under Perl 5.18 or higher, or a B::AV in
+earlier versions.
+
=item OUTSIDE
=item OUTSIDE_SEQ
=item const_sv
+=item NAME_HEK
+
+Returns the name of a lexical sub, otherwise C<undef>.
+
=back
=head2 B::HV Methods
=head2 OP-RELATED CLASSES
C<B::OP>, C<B::UNOP>, C<B::BINOP>, C<B::LOGOP>, C<B::LISTOP>, C<B::PMOP>,
-C<B::SVOP>, C<B::PADOP>, C<B::PVOP>, C<B::LOOP>, C<B::COP>.
+C<B::SVOP>, C<B::PADOP>, C<B::PVOP>, C<B::LOOP>, C<B::COP>, C<B::METHOP>.
These classes correspond in the obvious way to the underlying C
-structures of similar names. The inheritance hierarchy mimics the
+structures of similar names. The inheritance hierarchy mimics the
underlying C "inheritance":
B::OP
|
- +---------------+--------+--------+-------+
- | | | | |
- B::UNOP B::SVOP B::PADOP B::COP B::PVOP
+ +----------+---------+--------+-------+---------+
+ | | | | | |
+ B::UNOP B::SVOP B::PADOP B::COP B::PVOP B::METHOP
,' `-.
/ `--.
B::BINOP B::LOGOP
/ \
B::LOOP B::PMOP
-Access methods correspond to the underlying C structre field names,
+Access methods correspond to the underlying C structure field names,
with the leading "class indication" prefix (C<"op_">) removed.
=head2 B::OP Methods
=item sibling
+=item parent
+
+Returns the OP's parent. If it has no parent, or if your perl wasn't built
+with C<-DPERL_OP_PARENT>, returns NULL.
+
=item name
This returns the op name as a string (e.g. "add", "rv2av").
Only when perl was compiled with ithreads.
+=item code_list
+
+Since perl 5.17.1
+
=back
=head2 B::SVOP METHOD
=item stashpv
+=item stashoff (threaded only)
+
=item file
=item cop_seq
=back
+=head2 B::METHOP Methods (Since Perl 5.22)
+
+=over 4
+
+=item first
+
+=item meth_sv
+
+=back
+
+=head2 OTHER CLASSES
+
+Perl 5.18 introduces a new class, B::PADLIST, returned by B::CV's
+C<PADLIST> method.
+
+=head2 B::PADLIST Methods
+
+=over 4
+
+=item MAX
+
+=item ARRAY
+
+A list of pads. The first one contains the names. These are currently
+B::AV objects, but that is likely to change in future versions.
+
+=item ARRAYelt
+
+Like C<ARRAY>, but takes an index as an argument to get only one element,
+rather than a list of all of them.
+
+=item REFCNT
+
+=back
+
+=head2 $B::overlay
+
+Although the optree is read-only, there is an overlay facility that allows
+you to override what values the various B::*OP methods return for a
+particular op. C<$B::overlay> should be set to reference a two-deep hash:
+indexed by OP address, then method name. Whenever a an op method is
+called, the value in the hash is returned if it exists. This facility is
+used by B::Deparse to "undo" some optimisations. For example:
+
+
+ local $B::overlay = {};
+ ...
+ if ($op->name eq "foo") {
+ $B::overlay->{$$op} = {
+ name => 'bar',
+ next => $op->next->next,
+ };
+ }
+ ...
+ $op->name # returns "bar"
+ $op->next # returns the next op but one
+
=head1 AUTHOR
https://perl5.git.perl.org / perl5.git / blobdiff