X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/a3985cdcc04b13974afc5f4635645003847806e4..30d9c59b5f3cba8b5d632d20c2370e82d8ba69ca:/cv.h diff --git a/cv.h b/cv.h index 4611387..36afba7 100644 --- a/cv.h +++ b/cv.h @@ -1,38 +1,18 @@ /* cv.h * - * Copyright (c) 1991-2002, Larry Wall + * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, + * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others * * You may distribute under the terms of either the GNU General Public * License or the Artistic License, as specified in the README file. * */ -/* This structure much match XPVCV in B/C.pm and the beginning of XPVFM - * in sv.h */ +/* This structure must match the beginning of XPVFM in sv.h */ struct xpvcv { - char * xpv_pv; /* pointer to malloced string */ - STRLEN xpv_cur; /* length of xp_pv as a C string */ - STRLEN xpv_len; /* allocated size */ - IV xof_off; /* integer value */ - NV xnv_nv; /* numeric value, if any */ - MAGIC* xmg_magic; /* magic for scalar array */ - HV* xmg_stash; /* class package */ - - HV * xcv_stash; - OP * xcv_start; - OP * xcv_root; - void (*xcv_xsub) (pTHX_ CV*); - ANY xcv_xsubany; - GV * xcv_gv; - char * xcv_file; - long xcv_depth; /* >= 2 indicates recursive call */ - PADLIST * xcv_padlist; - CV * xcv_outside; - cv_flags_t xcv_flags; - U32 xcv_outside_seq; /* the COP sequence (at the point of our - * compilation) in the lexically enclosing - * sub */ + _XPV_HEAD; + _XPVCV_COMMON; }; /* @@ -41,48 +21,92 @@ struct xpvcv { =for apidoc AmU||Nullcv Null CV pointer. +(deprecated - use C<(CV *)NULL> instead) + =head1 CV Manipulation Functions +This section documents functions to manipulate CVs which are code-values, +or subroutines. For more information, see L. + =for apidoc Am|HV*|CvSTASH|CV* cv -Returns the stash of the CV. +Returns the stash of the CV. A stash is the symbol table hash, containing +the package-scoped variables in the package where the subroutine was defined. +For more information, see L. + +This also has a special use with XS AUTOLOAD subs. +See L. =cut */ -#define Nullcv Null(CV*) +#ifndef PERL_CORE +# define Nullcv Null(CV*) +#endif -#define CvSTASH(sv) ((XPVCV*)SvANY(sv))->xcv_stash -#define CvSTART(sv) ((XPVCV*)SvANY(sv))->xcv_start -#define CvROOT(sv) ((XPVCV*)SvANY(sv))->xcv_root -#define CvXSUB(sv) ((XPVCV*)SvANY(sv))->xcv_xsub -#define CvXSUBANY(sv) ((XPVCV*)SvANY(sv))->xcv_xsubany -#define CvGV(sv) ((XPVCV*)SvANY(sv))->xcv_gv -#define CvFILE(sv) ((XPVCV*)SvANY(sv))->xcv_file +#define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash) +#define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st) +#define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start +#define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root +#define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub +#define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany +#define CvGV(sv) S_CvGV((const CV *)(sv)) +#define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv) +#define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file #ifdef USE_ITHREADS -# define CvFILE_set_from_cop(sv, cop) (CvFILE(sv) = savepv(CopFILE(cop))) +# define CvFILE_set_from_cop(sv, cop) \ + (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv)) #else -# define CvFILE_set_from_cop(sv, cop) (CvFILE(sv) = CopFILE(cop)) +# define CvFILE_set_from_cop(sv, cop) \ + (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv)) #endif #define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) -#define CvDEPTH(sv) ((XPVCV*)SvANY(sv))->xcv_depth -#define CvPADLIST(sv) ((XPVCV*)SvANY(sv))->xcv_padlist -#define CvOUTSIDE(sv) ((XPVCV*)SvANY(sv))->xcv_outside -#define CvFLAGS(sv) ((XPVCV*)SvANY(sv))->xcv_flags -#define CvOUTSIDE_SEQ(sv) ((XPVCV*)SvANY(sv))->xcv_outside_seq - -#define CVf_CLONE 0x0001 /* anon CV uses external lexicals */ -#define CVf_CLONED 0x0002 /* a clone of one of those */ -#define CVf_ANON 0x0004 /* CvGV() can't be trusted */ -#define CVf_OLDSTYLE 0x0008 -#define CVf_UNIQUE 0x0010 /* can't be cloned */ -#define CVf_NODEBUG 0x0020 /* no DB::sub indirection for this CV +#define CvDEPTH(sv) (*S_CvDEPTHp((const CV *)sv)) +#define CvPADLIST(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist +#define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside +#define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags +#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq + +/* These two are sometimes called on non-CVs */ +#define CvPROTO(sv) \ + ( \ + SvPOK(sv) \ + ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ + ? SvEND(sv)+1 : SvPVX_const(sv) \ + : NULL \ + ) +#define CvPROTOLEN(sv) \ + ( \ + SvPOK(sv) \ + ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ + ? SvLEN(sv)-SvCUR(sv)-2 \ + : SvCUR(sv) \ + : 0 \ + ) + +#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ +#define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ +#define CVf_CONST 0x0004 /* inlinable sub */ +#define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ + +#define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ +#define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ +#define CVf_CLONED 0x0040 /* a clone of one of those */ +#define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ +#define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, + * require, eval). */ +#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV (esp. useful for special XSUBs) */ -#define CVf_METHOD 0x0040 /* CV is explicitly marked as a method */ -#define CVf_LOCKED 0x0080 /* CV locks itself or first arg on entry */ -#define CVf_LVALUE 0x0100 /* CV return value can be used as lvalue */ -#define CVf_CONST 0x0200 /* inlinable sub */ +#define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ +#ifdef PERL_CORE +# define CVf_SLABBED 0x0800 /* Holds refcount on op slab */ +#endif +#define CVf_DYNFILE 0x1000 /* The filename isn't static */ +#define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */ +#define CVf_HASEVAL 0x4000 /* contains string eval */ +#define CVf_NAMED 0x8000 /* Has a name HEK */ + /* This symbol for optimised communication between toke.c and op.c: */ -#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LOCKED|CVf_LVALUE) +#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE) #define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) #define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) @@ -96,12 +120,7 @@ Returns the stash of the CV. #define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) #define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) -#ifdef PERL_XSUB_OLDSTYLE -#define CvOLDSTYLE(cv) (CvFLAGS(cv) & CVf_OLDSTYLE) -#define CvOLDSTYLE_on(cv) (CvFLAGS(cv) |= CVf_OLDSTYLE) -#define CvOLDSTYLE_off(cv) (CvFLAGS(cv) &= ~CVf_OLDSTYLE) -#endif - +/* CvEVAL or CvSPECIAL */ #define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) #define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) #define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) @@ -114,19 +133,16 @@ Returns the stash of the CV. #define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD) #define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD) -#define CvLOCKED(cv) (CvFLAGS(cv) & CVf_LOCKED) -#define CvLOCKED_on(cv) (CvFLAGS(cv) |= CVf_LOCKED) -#define CvLOCKED_off(cv) (CvFLAGS(cv) &= ~CVf_LOCKED) - #define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE) #define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE) #define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE) +/* eval or PL_main_cv */ #define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv)) #define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv)) #define CvEVAL_off(cv) CvUNIQUE_off(cv) -/* BEGIN|CHECK|INIT|END */ +/* BEGIN|CHECK|INIT|UNITCHECK|END */ #define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv)) #define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv)) #define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv)) @@ -135,3 +151,130 @@ Returns the stash of the CV. #define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST) #define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST) +#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE) +#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE) +#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE) + +#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB) +#define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB) +#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB) + +#define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC) +#define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC) +#define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC) + +#ifdef PERL_CORE +# define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED) +# define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED) +# define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED) +#endif + +#define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE) +#define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE) +#define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE) + +#define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD) +#define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD) +#define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD) + +#define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL) +#define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL) +#define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL) + +#define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED) +#define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED) +#define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED) + +/* Flags for newXS_flags */ +#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ + +PERL_STATIC_INLINE GV * +S_CvGV(const CV *sv) +{ + return CvNAMED(sv) + ? 0 + : ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_gv; +} +PERL_STATIC_INLINE HEK * +CvNAME_HEK(CV *sv) +{ + return CvNAMED(sv) + ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek + : 0; +} +/* This lowers the refernce count of the previous value, but does *not* + increment the reference count of the new value. */ +#define CvNAME_HEK_set(cv, hek) ( \ + CvNAME_HEK((CV *)(cv)) \ + ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \ + : (void)0, \ + ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \ + CvNAMED_on(cv) \ + ) + +/* +=head1 CV reference counts and CvOUTSIDE + +=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv + +Each CV has a pointer, C, to its lexically enclosing +CV (if any). Because pointers to anonymous sub prototypes are +stored in C<&> pad slots, it is a possible to get a circular reference, +with the parent pointing to the child and vice-versa. To avoid the +ensuing memory leak, we do not increment the reference count of the CV +pointed to by C in the I that the parent +has a C<&> pad slot pointing back to us. In this case, we set the +C flag in the child. This allows us to determine under what +circumstances we should decrement the refcount of the parent when freeing +the child. + +There is a further complication with non-closure anonymous subs (i.e. those +that do not refer to any lexicals outside that sub). In this case, the +anonymous prototype is shared rather than being cloned. This has the +consequence that the parent may be freed while there are still active +children, eg + + BEGIN { $a = sub { eval '$x' } } + +In this case, the BEGIN is freed immediately after execution since there +are no active references to it: the anon sub prototype has +C set since it's not a closure, and $a points to the same +CV, so it doesn't contribute to BEGIN's refcount either. When $a is +executed, the C causes the chain of Cs to be followed, +and the freed BEGIN is accessed. + +To avoid this, whenever a CV and its associated pad is freed, any +C<&> entries in the pad are explicitly removed from the pad, and if the +refcount of the pointed-to anon sub is still positive, then that +child's C is set to point to its grandparent. This will only +occur in the single specific case of a non-closure anon prototype +having one or more active references (such as C<$a> above). + +One other thing to consider is that a CV may be merely undefined +rather than freed, eg C. In this case, its refcount may +not have reached zero, but we still delete its pad and its C etc. +Since various children may still have their C pointing at this +undefined CV, we keep its own C for the time being, so that +the chain of lexical scopes is unbroken. For example, the following +should print 123: + + my $x = 123; + sub tmp { sub { eval '$x' } } + my $a = tmp(); + undef &tmp; + print $a->(); + +=cut +*/ + +typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); + +/* + * Local variables: + * c-indentation-style: bsd + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + * + * ex: set ts=8 sts=4 sw=4 et: + */