# NAME
Opcodes - More Opcodes information from opnames.h and opcode.h
# SYNOPSIS
use Opcodes;
print "Empty opcodes are null and ",
join ",", map {opname $_}, opaliases(opname2code('null'));
# All LOGOPs
perl -MOpcodes -e'$,=q( );print map {opname $_} grep {opclass($_) == 2} 1..opcodes'
# Ops which can return other than op->next
perl -MOpcodes -e'$,=q( );print map {opname $_} grep {Opcodes::maybranch $_} 1..opcodes'
# DESCRIPTION
# Operator Names and Operator Lists
The canonical list of operator names is the contents of the array
PL\_op\_name, defined and initialised in file `opcode.h` of the Perl
source distribution (and installed into the perl library).
Each operator has both a terse name (its opname) and a more verbose or
recognisable descriptive name. The opdesc function can be used to
return a the description for an OP.
- an operator name (opname)
Operator names are typically small lowercase words like enterloop,
leaveloop, last, next, redo etc. Sometimes they are rather cryptic
like gv2cv, i\_ncmp and ftsvtx.
- an OP opcode
The opcode information functions all take the integer code, 0..MAX0,
MAXO being accessed by scalar @opcodes, the length of
the opcodes array.
# Opcode Information
Retrieve information of the Opcodes. All are available for export by the package.
Functions names starting with "op" are automatically exported.
- opcodes
In a scalar context opcodes returns the number of opcodes in this
version of perl (361 with perl-5.10).
In a list context it returns a list of all the operators with
its properties, a list of \[ opcode opname ppaddr check opargs \].
- opname (OP)
Returns the lowercase name without pp\_ for the OP,
an integer between 0 and MAXO.
- ppaddr (OP)
Returns the address of the ppaddr, which can be used to
get the aliases for each opcode.
- check (OP)
Returns the address of the check function.
- opdesc (OP)
Returns the string description of the OP.
- opargs (OP)
Returns the opcode args encoded as integer of the opcode.
See below or `opcode.pl` for the encoding details.
opflags 1-128 + opclass 1-13 << 9 + argnum 1-15.. << 13
- argnum (OP)
Returns the arguments and types encoded as number acccording
to the following table, 4 bit for each argument.
'S', 1, # scalar
'L', 2, # list
'A', 3, # array value
'H', 4, # hash value
'C', 5, # code value
'F', 6, # file value
'R', 7, # scalar reference
+ '?', 8, # optional
Example:
argnum(opname2code('bless')) => 145
145 = 0b10010001 => S S?
first 4 bits 0001 => 1st arg is a Scalar,
next 4 bits 1001 => (bit 8+1) 2nd arg is an optional Scalar
- opclass (OP)
Returns the op class as number according to the following table
from `opcode.pl`:
'0', 0, # baseop
'1', 1, # unop
'2', 2, # binop
'|', 3, # logop
'@', 4, # listop
'/', 5, # pmop
'$', 6, # svop_or_padop
'#', 7, # padop
'"', 8, # pvop_or_svop
'{', 9, # loop
';', 10, # cop
'%', 11, # baseop_or_unop
'-', 12, # filestatop
'}', 13, # loopexop
- opflags (OP)
Returns op flags as number according to the following table
from `opcode.pl`. In doubt see your perl source.
_Warning: There is currently an attempt to change that, but I posted a fix_
'm' => OA_MARK, # needs stack mark
'f' => OA_FOLDCONST, # fold constants
's' => OA_RETSCALAR, # always produces scalar
't' => OA_TARGET, # needs target scalar
'T' => OA_TARGET | OA_TARGLEX, # ... which may be lexical
'i' => OA_RETINTEGER, # always produces integer (this bit is in question)
'I' => OA_OTHERINT, # has corresponding int op
'd' => OA_DANGEROUS, # danger, unknown side effects
'u' => OA_DEFGV, # defaults to $_
plus not from `opcode.pl`:
'n' => OA_NOSTACK, # nothing on the stack, no args and return
'N' => OA_MAYBRANCH # No next. may return other than PL_op->op_next, maybranch
These not yet:
'S' => OA_MAYSCALAR # retval may be scalar
'A' => OA_MAYARRAY # retval may be array
'V' => OA_MAYVOID # retval may be void
'F' => OA_RETFIXED # fixed retval type, either S or A or V
- OA\_\* constants
All OA\_ flag, class and argnum constants from `op.h` are exported.
Addionally new OA\_ flags have been created which are needed for [B::CC](
https://metacpan.org/pod/B::CC).
- opaliases (OP)
Returns the opcodes for the aliased opcode functions for the given OP, the ops
with the same ppaddr.
- opname2code (OPNAME)
Does a reverse lookup in the opcodes list to get the opcode for the given
name.
- maybranch (OP)
Returns if the OP function may return not op->op\_next.
Note that not all OP classes which have op->op\_other, op->op\_first or op->op\_last
(higher then UNOP) are actually returning an other next op than op->op\_next.
opflags(OP) & 16384
# SEE ALSO
[Opcode](
https://metacpan.org/pod/Opcode) -- The Perl CORE Opcode module for handling sets of Opcodes used by [Safe](
https://metacpan.org/pod/Safe).
[Safe](
https://metacpan.org/pod/Safe) -- Opcode and namespace limited execution compartments
[B::CC](
https://metacpan.org/pod/B::CC) -- The optimizing perl compiler uses this module. [Jit](
https://metacpan.org/pod/Jit) also,
but only the static information
# TEST REPORTS
CPAN Testers: [
http://cpantesters.org/distro/O/Opcodes](
http://cpantesters.org/distro/O/Opcodes)
[](
https://travis-ci.org/rurban/Opcodes/)
[](
https://coveralls.io/r/rurban/Opcodes?branch=master)
# AUTHOR
Reini Urban `
[email protected]` 2010, 2014
# LICENSE
Copyright 1995, Malcom Beattie.
Copyright 1996, Tim Bunce.
Copyright 2010, 2014 Reini Urban.
All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
