=head1 NAME B - The Perl Compiler J<< ja; B - Perl コンパイラ >> =head1 SYNOPSIS use B; =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 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 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. J<< ja; C モジュールは Perl プログラムに自分自身の体内を探るためのクラス群を提供します. Perl コンパイラの"バックエンド"の実装にもこのモジュールが使われています. 単にコンパイラの使い方であればこのモジュールの知識を必要としません: ユーザから見える部分に関しては F モジュールを参照してください. C モジュールは新しいコンパイラバックエンドを書く人のためのモジュールです. このドキュメントでは読み手がperlの内部構造, SV, OP, 内部シンボルテーブル, プログラムの構文ツリーなどに相当詳しいことを前提としています. >> =head1 OVERVIEW J<< ja; 概要 >> The C module contains a set of utility functions for querying the current state of the Perl interpreter; typically these functions return objects from the B::SV and B::OP classes, or their derived classes. These classes in turn define methods for querying the resulting objects about their own internal state. J<< ja; C モジュールはPerlインタプリタの現在の状態を問い合わせるためのユーティリティ関数群を含んでいます. これらの関数の多くは B::SV 及び B::OP クラス及びこれらの派生クラスのオブジェクトを返します. これらのクラスはそれらの中でそれらの内部状態に関して問い合わせるためのメソッドを定義しています. >> =head1 Utility Functions J<< ja; ユーティリティ関数 >> The C module exports a variety of functions: some are simple utility functions, others provide a Perl program with a way to get an initial "handle" on an internal object. J<< ja; C モジュールは様々な関数をエクスポートします. いくつかは簡単なユーティリティ関数ですが, それ以外は内部オブジェクトの入り口となる"ハンドル" (initial "handle")を取得する方法を提供します. >> =head2 Functions Returning C, C, C, and C objects J<< ja; C 若しくは C, C, C オブジェクトを返す関数 >> For descriptions of the class hierarchy of these objects and the methods that can be called on them, see below, L<"OVERVIEW OF CLASSES"> and L<"SV-RELATED CLASSES">. J<< ja; これらのクラスの階層図及び呼び出せるメソッドに関しては, 後述の L<"OVERVIEW OF CLASSES"> 及び L<"SV-RELATED CLASSES"> を参照してください. >> =over 4 =item sv_undef Returns the SV object corresponding to the C variable C. J<< ja; Cでの変数Cに対応するSVオブジェクトを返します. >> =item sv_yes Returns the SV object corresponding to the C variable C. J<< ja; Cでの変数Cに対応するSVオブジェクトを返します. >> =item sv_no Returns the SV object corresponding to the C variable C. J<< ja; Cでの変数Cに対応するSVオブジェクトを返します. >> =item svref_2object(SVREF) 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 way to get an initial "handle" on an internal perl data structure which can then be followed with the other access methods. J<< ja; 何らかの Perl の値へのリファレンスを受け取り, 参照されている値を対応する B:OP もしくは B::SV クラス派生のオブジェクトに変換します. C の様な関数は別として, これはperlの内部データ構造の入り口となる"ハンドル"(initial "handle")を取得する主要な方法です. ここから他のアクセスメソッドを使うことになります. >> 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 underlying structures are freed. J<< ja; 返されるオブジェクトはOPやSVが存在しているのと同じ間だけ有効です. 参照する構造が解放された後はそのオブジェクトを使わないでください. >> =item amagic_generation Returns the SV object corresponding to the C variable C. J<< ja; Cでの変数Cに対応するSVオブジェクトを返します. >> =item init_av Returns the AV object (i.e. in class B::AV) representing INIT blocks. J<< ja; INIT ブロックを表現する AV オブジェクト(つまりB::AVクラスのオブジェクト)を返します. >> =item check_av Returns the AV object (i.e. in class B::AV) representing CHECK blocks. J<< ja; CHECK ブロックを表現する AV オブジェクト(つまりB::AVクラスのオブジェクト)を返します. >> =item begin_av Returns the AV object (i.e. in class B::AV) representing BEGIN blocks. J<< ja; BEGIN ブロックを表現する AV オブジェクト(つまりB::AVクラスのオブジェクト)を返します. >> =item end_av Returns the AV object (i.e. in class B::AV) representing END blocks. J<< ja; END ブロックを表現する AV オブジェクト(つまりB::AVクラスのオブジェクト)を返します. >> =item comppadlist Returns the AV object (i.e. in class B::AV) of the global comppadlist. J<< ja; グローバルcomppadlistの AV オブジェクト(つまりB::AVクラスのオブジェクト)を返します. >> =item regex_padav Only when perl was compiled with ithreads. J<< ja; perl が ithreads でコンパイルされたときのみ. >> =item main_cv Return the (faked) CV corresponding to the main part of the Perl program. J<< ja; Perlプログラムのメイン部分に対応する(擬似的な)CVを返します. >> =back =head2 Functions for Examining the Symbol Table J<< ja; シンボルテーブルを調査する関数 >> =over 4 =item walksymtable(SYMREF, METHOD, RECURSE, PREFIX) Walk the symbol table starting at SYMREF and call METHOD on each symbol (a B::GV object) visited. When the walk reaches package symbols (such as "Foo::") it invokes RECURSE, passing in the symbol name, and only recurses into the package if that sub returns true. J<< ja; SYMREF からシンボルテーブルを歩き始め, 各シンボル(B::GVオブジェクト) に着く度にMETHODを呼び出します. 巡回がパッケージシンボルに辿り着いたときシンボル名を引数にRECURSEを呼び出し, 関数が真を返した時にのみ再帰的にパッケージを進みます. >> PREFIX is the name of the SYMREF you're walking. J<< ja; PREFIX は巡回するSYMREFの名前です. >> For example: J<< ja; 例えば: >> # 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::'); print_subs() is a B::GV method you have declared. Also see L<"B::GV Methods">, below. J<< ja; print_subs() は自分で宣言した B::GV メソッドです. 後述のL<"B::GV Methods">を参照してください. >> =back =head2 Functions Returning C objects or for walking op trees J<< ja; C オブジェクトを返す関数及びopツリーの巡回 >> For descriptions of the class hierarchy of these objects and the methods that can be called on them, see below, L<"OVERVIEW OF CLASSES"> and L<"OP-RELATED CLASSES">. J<< ja; これらのクラスの階層図及び呼び出せるメソッドに関しては, 後述の L<"OVERVIEW OF CLASSES"> 及び L<"SV-RELATED CLASSES"> を参照してください. >> =over 4 =item main_root Returns the root op (i.e. an object in the appropriate B::OP-derived class) of the main part of the Perl program. J<< ja; Perlプラグラムのメイン部分に当たるルートop(つまり適当な B::OP から派生したクラスのオブジェクト)を返します. >> =item main_start Returns the starting op of the main part of the Perl program. J<< ja; Perl プラグラムのメイン部分の始まるopを返します. >> =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 C (see below) has been called to turn debugging on then the method C is called on each op before METHOD is called. J<< ja; OP から構文ツリーを辿って各opでMETHODを呼び出します. ノードは子の前に呼び出されます. C(後述)がデバッグを有効にするように呼び出されていたら, 各opでMETHODが呼び出される前に C が呼び出されます. >> =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 the description of C above for what the debugging flag does. J<< ja; 現在の C のデバッグフラグを返します. もし任意の引数 DEBUG が0でなければ, デバッグフラグをその値に設定します. デバッグフラグが何を行うのかは前述のCを参照してください. >> =back =head2 Miscellaneous Utility Functions J<< ja; いろいろなユーティリティ関数 >> =over 4 =item ppname(OPNUM) Return the PP function name (e.g. "pp_add") of op number OPNUM. J<< ja; op番号OPNUMのPP関数名(例えば "pp_add")を返します. >> =item hash(STR) Returns a string in the form "0x..." representing the value of the internal hash function used by perl on string STR. J<< ja; 文字列STRに対するperlが使うハッシュ値を "0x..." という形式の文字列で返します. >> =item cast_I32(I) Casts I to the internal I32 type used by that perl. J<< ja; I を perl内部の I32 型にキャストします. >> =item minus_c 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. J<< ja; C<-c> コマンドラインオプションと同じことをします. 明らかなことですが, これは BEGIN ブロックの中でのみ有効であって, それ以外では遅すぎます. >> =item cstring(STR) Returns a double-quote-surrounded escaped version of STR which can be used as a string in C source code. J<< ja; Cソースコードで文字列として使えるようにダブルクオートで囲んだバージョンのSTRを返します. >> =item perlstring(STR) Returns a double-quote-surrounded escaped version of STR which can be used as a string in Perl source code. J<< ja; Perlソースコードで文字列として使えるようにダブルクオートで囲んだバージョンのSTRを返します. >> =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 C<"UNOP"> for example. J<< ja; オブジェクトのクラスを, 最初のC<"::">の前に当たる部分を省いて返します. >> =item threadsv_names In a perl compiled for threads, this returns a list of the special per-thread threadsv variables. J<< ja; スレッド対応でコンパイルされているperlで, 特殊なスレッド毎のthreadsv 変数のリストを返します. >> =back =head1 OVERVIEW OF CLASSES J<< ja; クラスの概要 >> 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 (whether types of SV or types of OP) are represented by the C module as Perl objects of the appropriate class. J<< ja; Perl の内部で SV 及び OP 情報 (PVIV, AV, HV, ..., OP, SVOP, UNOP, ...) を保持するために使われる C 構造体はクラス階層としてモデル化されており, C モジュールからはそれらに対して真にクラス階層と仕手のアクセスが提供されています. 他のオブジェクト(SV か OP の一種)を参照する構造体フィールドは適切なクラスの Perl オブジェクトとして C モジュールによって表現されます. >> The bulk of the C module is the methods for accessing fields of these structures. J<< ja; C モジュールの大部分はこれらの構造体のフィールドにアクセスするためのメソッドです. >> 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 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 give incomprehensible results, or worse. J<< ja; 全てのアクセスは読み込み専用です. このモジュールでは内部の変更はできません. また, このモジュールによって生成される B::OP や B::SV のオブジェクトはそれの元となっているオブジェクトが存在している間のみ有効です; これらの生成は元のオブジェクトの参照カウンタの増加は行いません. 解放されたオブジェクトのフィールドへのアクセスは不可解な結果, 若しくはもっと悪い結果になるでしょう. >> =head2 SV-RELATED CLASSES J<< ja; SV に関連するクラス >> B::IV, B::NV, B::RV, B::PV, B::PVIV, B::PVNV, B::PVMG, B::BM, 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 5.9.1 and later this is: J<< ja; B::IV, B::NV, B::RV, B::PV, B::PVIV, B::PVNV, B::PVMG, B::BM, B::PVLV, B::AV, B::HV, B::CV, B::GV, B::FM, B::IO. これらのクラスは同じような名前を持つ C 構造体への経路に相当します. 継承階層は元になっている C "継承" に倣っています. 5.9.1 及びそれ以降では次のようになります: >> B::SV | +--------------+----------------------+ | | | B::PV B::IV B::RV | \ / \ | \ / \ | B::PVIV B::NV \ / \____ __/ \ / B::PVNV | | B::PVMG | +-----+----+------+-----+-----+ | | | | | | B::BM B::AV B::GV B::HV B::CV B::IO | | B::PVLV | B::FM For 5.9.0 and earlier, PVLV is a direct subclass of PVMG, so the base of this diagram is J<< ja; 5.9.0 及びそれ以前では, PVLV は PVMV の直接のサブクラスで, この図の下の部分は次のようになっていました: >> | B::PVMG | +------+-----+----+------+-----+-----+ | | | | | | | B::PVLV B::BM B::AV B::GV B::HV B::CV B::IO | | B::FM 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 as-is since its abbreviation would clash with the "superclass" method C (corresponding to the C function C). J<< ja; アクセスメソッドはフィールドアクセスのための C マクロを元に対応していますが, 大抵ついていた"クラス識別"前置句ははずされています (Sv, Av, Hv, ...). 前置句はそれを外すとメソッド名がぶつかる時にだけ残っています. 例えば C はその短縮形がスーパークラスのメソッド C (C 関数 C に対応) とぶつかるのでそのままになっています. >> =head2 B::SV Methods J<< ja; B::SV メソッド >> =over 4 =item REFCNT =item FLAGS =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 at should be considered read-only: modifying them is neither safe nor guaranteed to have a sensible effect. =back =head2 B::IV Methods =over 4 =item IV Returns the value of the IV, I. This will be misleading if C. Perhaps you want the C method instead? =item IVX =item UVX =item int_value This method returns the value of the IV as an integer. It differs from C in that it returns the correct value regardless of whether it's stored signed or unsigned. =item needs64bits =item packiv =back =head2 B::NV Methods =over 4 =item NV =item NVX =back =head2 B::RV Methods =over 4 =item RV =back =head2 B::PV Methods =over 4 =item PV 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 RV Same as B::RV::RV, except that it will die() if the PV isn't a reference. =item PVX 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 are always stored with a null terminator, and the length field (SvCUR) is overloaded for other purposes and can't be relied on here. =back =head2 B::PVMG Methods =over 4 =item MAGIC =item SvSTASH =back =head2 B::MAGIC Methods =over 4 =item MOREMAGIC =item precomp Only valid on r-magic, returns the string that generated the regexp. =item PRIVATE =item TYPE =item FLAGS =item OBJ Will die() if called on r-magic. =item PTR =item REGEX Only valid on r-magic, returns the integer value of the REGEX stored in the MAGIC. =back =head2 B::PVLV Methods =over 4 =item TARGOFF =item TARGLEN =item TYPE =item TARG =back =head2 B::BM Methods =over 4 =item USEFUL =item PREVIOUS =item RARE =item TABLE =back =head2 B::GV Methods =over 4 =item is_empty This method returns TRUE if the GP field of the GV is NULL. =item NAME =item SAFENAME This method returns the name of the glob, but if the first character of the name is a control character, then it converts it to ^X first, so that *^G would return "^G" rather than "\cG". It's useful if you want to print out the name of a variable. If you restrict yourself to globs which exist at compile-time then the result ought to be unambiguous, because code like C<${"^G"} = 1> is compiled as two ops - a constant string and a dereference (rv2gv) - so that the glob is created at runtime. If you're working with globs at runtime, and need to disambiguate *^G from *{"^G"}, then you should use the raw NAME method. =item STASH =item SV =item IO =item FORM =item AV =item HV =item EGV =item CV =item CVGEN =item LINE =item FILE =item FILEGV =item GvREFCNT =item FLAGS =back =head2 B::IO Methods =over 4 =item LINES =item PAGE =item PAGE_LEN =item LINES_LEFT =item TOP_NAME =item TOP_GV =item FMT_NAME =item FMT_GV =item BOTTOM_NAME =item BOTTOM_GV =item SUBPROCESS =item IoTYPE =item IoFLAGS =item IsSTD Takes one arguments ( '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() ). =back =head2 B::AV Methods =over 4 =item FILL =item MAX =item OFF =item ARRAY =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 AvFLAGS =back =head2 B::CV Methods =over 4 =item STASH =item START =item ROOT =item GV =item FILE =item DEPTH =item PADLIST =item OUTSIDE =item OUTSIDE_SEQ =item XSUB =item XSUBANY For constant subroutines, returns the constant SV returned by the subroutine. =item CvFLAGS =item const_sv =back =head2 B::HV Methods =over 4 =item FILL =item MAX =item KEYS =item RITER =item NAME =item PMROOT =item ARRAY =back =head2 OP-RELATED CLASSES 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 underlying C "inheritance": J<< ja; これらのクラスは似た名前のC構造体と対応しています. 疑似継承構造はCの"継承"に基を成します. >> B::OP | +---------------+--------+--------+ | | | | B::UNOP B::SVOP B::PADOP B::COP ,' `-. / `--. B::BINOP B::LOGOP | | B::LISTOP ,' `. / \ B::LOOP B::PMOP Access methods correspond to the underlying C structre field names, with the leading "class indication" prefix (C<"op_">) removed. J<< ja; C構造体のフィールドにアクセスするときは, "クラス指示" 接頭辞(C<"op_">) を取り除いたメソッドを使います. >> =head2 B::OP Methods J<< ja; B::OP のメソッド >> These methods get the values of similarly named fields within the OP data structure. See top of C for more info. J<< ja; これらのメソッドでは OP データ構造の似た名前のフィールドの値を取得します. より詳細な情報は C の最初を参照してください. >> =over 4 =item next =item sibling =item name J<< ja; Z<> name >> This returns the op name as a string (e.g. "add", "rv2av"). J<< ja; これはop名を文字列で返します(例: "add", "rv2av"). >> =item ppaddr This returns the function name as a string (e.g. "PL_ppaddr[OP_ADD]", "PL_ppaddr[OP_RV2AV]"). J<< ja; これは関数名を文字列で返します(例: "PL_ppaddr[OP_ADD]", "PL_ppaddr[OP_RV2AV]"). >> =item desc This returns the op description from the global C PL_op_desc array (e.g. "addition" "array deref"). J<< ja; これはopの説明をCのグローバルPL_op_desc配列から返します(例: "addition" "array deref"). >> =item targ =item type =item opt =item static =item flags =item private =item spare =back =head2 B::UNOP METHOD =over 4 =item first =back =head2 B::BINOP METHOD =over 4 =item last =back =head2 B::LOGOP METHOD =over 4 =item other =back =head2 B::LISTOP METHOD =over 4 =item children =back =head2 B::PMOP Methods =over 4 =item pmreplroot =item pmreplstart =item pmnext =item pmregexp =item pmflags =item pmdynflags =item pmpermflags =item precomp =item pmoffset Only when perl was compiled with ithreads. =back =head2 B::SVOP METHOD =over 4 =item sv =item gv =back =head2 B::PADOP METHOD =over 4 =item padix =back =head2 B::PVOP METHOD =over 4 =item pv =back =head2 B::LOOP Methods =over 4 =item redoop =item nextop =item lastop =back =head2 B::COP Methods =over 4 =item label =item stash =item stashpv =item file J<< ja; Z<> file >> =item cop_seq =item arybase =item line =item warnings J<< ja; Z<> warnings >> =item io =back =head1 AUTHOR Malcolm Beattie, C