X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/744aaba0598b45009977ebe8c7d6dc376288e2e4..486b1e7f08f6ed37f4e5b11823cc569ad2140246:/ext/B/B.pm diff --git a/ext/B/B.pm b/ext/B/B.pm index 4cd5545..35b81cf 100644 --- a/ext/B/B.pm +++ b/ext/B/B.pm @@ -15,27 +15,28 @@ require Exporter; # walkoptree comes from B.xs BEGIN { - $B::VERSION = '1.25'; - - @B::EXPORT_OK = qw(minus_c ppname save_BEGINs - class peekop cast_I32 cstring cchar hash threadsv_names - main_root main_start main_cv svref_2object opnumber - sub_generation amagic_generation perlstring - walkoptree_slow walkoptree walkoptree_exec walksymtable - 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 - ); - push @B::EXPORT_OK, qw(unitcheck_av) if $] > 5.009; - - # All the above in this BEGIN, because our BOOT code needs $VERSION set, - # and will append to @EXPORT_OK. And we need to run the BOOT code before - # we see OPf_KIDS below. + $B::VERSION = '1.45'; + @B::EXPORT_OK = (); + + # Our BOOT code needs $VERSION set, and will append to @EXPORT_OK. + # Want our constants loaded before the compiler meets OPf_KIDS below, as + # the combination of having the constant stay a Proxy Constant Subroutine + # and its value being inlined saves a little over .5K + require XSLoader; XSLoader::load(); } +push @B::EXPORT_OK, (qw(minus_c ppname save_BEGINs + class peekop cast_I32 cstring cchar hash threadsv_names + main_root main_start main_cv svref_2object opnumber + sub_generation amagic_generation perlstring + walkoptree_slow walkoptree walkoptree_exec walksymtable + 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 unitcheck_av)); + @B::SV::ISA = 'B::OBJECT'; @B::NULL::ISA = 'B::SV'; @B::PV::ISA = 'B::SV'; @@ -47,10 +48,8 @@ BEGIN { @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::PVLV::ISA = 'B::GV'; +@B::BM::ISA = 'B::GV'; @B::AV::ISA = 'B::PVMG'; @B::GV::ISA = 'B::PVMG'; @B::HV::ISA = 'B::PVMG'; @@ -105,8 +104,15 @@ sub B::IV::int_value { } sub B::NULL::as_string() {""} -sub B::IV::as_string() {goto &B::IV::int_value} -sub B::PV::as_string() {goto &B::PV::PV} +*B::IV::as_string = \*B::IV::int_value; +*B::PV::as_string = \*B::PV::PV; + +# The input typemap checking makes no distinction between different SV types, +# so the XS body will generate the same C code, despite the different XS +# "types". So there is no change in behaviour from doing "newXS" like this, +# compared with the old approach of having a (near) duplicate XS body. +# We should fix the typemap checking. +*B::IV::RV = \*B::PV::RV if $] > 5.012; my $debug; my $op_count = 0; @@ -244,7 +250,8 @@ sub walksymtable { 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; @@ -338,11 +345,11 @@ B - The Perl Compiler Backend =head1 DESCRIPTION The C 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 module for the -user-visible part. The C module is of use to those who want to -write new compiler backends. This documentation assumes that the +user-visible part. The C 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. @@ -385,17 +392,19 @@ Returns the SV object corresponding to the C variable C. 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, this is the primary +class. Apart from functions such as C, 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. +As of Perl 5.18, this is just an alias to C, so its value is +meaningless. =item init_av @@ -419,7 +428,9 @@ Returns the AV object (i.e. in class B::AV) representing END blocks. =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 @@ -449,10 +460,10 @@ For example: # Walk CGI's symbol table calling print_subs on each symbol. # Recurse only into CGI::Util:: - walksymtable(\%CGI::, 'print_subs', sub { $_[0] eq 'CGI::Util::' }, - 'CGI::'); + 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 @@ -477,15 +488,15 @@ Returns the starting op of the main part of the Perl program. =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 (see below) has been called to turn debugging on then the method C is called on each op before METHOD is called. =item walkoptree_debug(DEBUG) -Returns the current debugging flag for C. If the optional -DEBUG argument is non-zero, it sets the debugging flag to that. See +Returns the current debugging flag for C. If the optional +DEBUG argument is non-zero, it sets the debugging flag to that. See the description of C above for what the debugging flag does. @@ -510,7 +521,7 @@ Casts I to the internal I32 type used by that perl. =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) @@ -526,7 +537,7 @@ be used as a string in Perl source code. =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 @@ -536,7 +547,7 @@ per-thread threadsv variables. =back -=head2 Exported utility variabiles +=head2 Exported utility variables =over 4 @@ -563,7 +574,7 @@ or '&PL_sv_undef'). 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 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 module as Perl objects of the appropriate class. @@ -571,18 +582,18 @@ The bulk of the C module is the methods for accessing fields of 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 5.10.0, 5.10.1 I) this is: B::SV @@ -652,8 +663,8 @@ references, and a new type B::REGEXP is introduced, giving this structure: 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 stays +Hv, ...). The leading prefix is only left in cases where its removal +would cause a clash in method name. For example, C stays as-is since its abbreviation would clash with the "superclass" method C (corresponding to the C function C). @@ -668,8 +679,8 @@ C (corresponding to the C function C). =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. @@ -682,8 +693,8 @@ guaranteed to have a sensible effect. =item IV Returns the value of the IV, I. This will be misleading -if C. Perhaps you want the +a signed integer>. This will be misleading +if C. Perhaps you want the C method instead? =item IVX @@ -727,7 +738,7 @@ unsigned. =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. @@ -739,14 +750,24 @@ a reference. =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 -(SvCUR) is overloaded for other purposes and can't be relied on here. +(CUR) is overloaded for other purposes and can't be relied on here. + +=item CUR + +This method returns the internal length field, which consists of the number +of internal bytes, not necessarily the number of logical characters. + +=item LEN + +This method returns the number of bytes allocated (via malloc) for storing +the string. This is 0 if the scalar does not "own" the string. =back @@ -874,6 +895,15 @@ If you're working with globs at runtime, and need to disambiguate =head2 B::IO Methods +B::IO objects derive from IO objects and you will get more information from +the IO object itself. + +For example: + + $gvio = B::svref_2object(\*main::stdin)->IO; + $IO = $gvio->object_2svref(); + $fd = $IO->fileno(); + =over 4 =item LINES @@ -900,14 +930,29 @@ If you're working with globs at runtime, and need to disambiguate =item IoTYPE +A character symbolizing the type of IO Handle. + + - STDIN/OUT + I STDIN/OUT/ERR + < read-only + > write-only + a append + + read and write + s socket + | pipe + I IMPLICIT + # NUMERIC + space closed handle + \0 closed internal handle + =item IoFLAGS =item IsSTD -Takes one arguments ( 'stdin' | 'stdout' | 'stderr' ) and returns true +Takes one argument ( 'stdin' | 'stdout' | 'stderr' ) and returns true if the IoIFP of the object is equal to the handle whose name was -passed as argument ( i.e. $io->IsSTD('stderr') is true if -IoIFP($io) == PerlIO_stdin() ). +passed as argument; i.e., $io->IsSTD('stderr') is true if +IoIFP($io) == PerlIO_stderr(). =back @@ -933,7 +978,8 @@ if running under Perl 5.9 =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 @@ -956,6 +1002,9 @@ in with the main SV flags, so this method is no longer present. =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 @@ -970,6 +1019,10 @@ For constant subroutines, returns the constant SV returned by the subroutine. =item const_sv +=item NAME_HEK + +Returns the name of a lexical sub, otherwise C. + =back =head2 B::HV Methods @@ -1001,7 +1054,7 @@ C, C, C, C, C, C, C, C, C, C, C. 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 @@ -1019,7 +1072,7 @@ underlying C "inheritance": / \ 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 @@ -1117,6 +1170,10 @@ Since Perl 5.9.5 Only when perl was compiled with ithreads. +=item code_list + +Since perl 5.17.1 + =back =head2 B::SVOP METHOD @@ -1167,6 +1224,8 @@ Only when perl was compiled with ithreads. =item stashpv +=item stashoff (threaded only) + =item file =item cop_seq @@ -1185,6 +1244,53 @@ Only when perl was compiled with ithreads. =back +=head2 OTHER CLASSES + +Perl 5.18 introduces a new class, B::PADLIST, returned by B::CV's +C 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, 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