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Diffstat (limited to 'Master/tlpkg/tlperl.straw/lib/CORE/cv.h')
| -rwxr-xr-x | Master/tlpkg/tlperl.straw/lib/CORE/cv.h | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/Master/tlpkg/tlperl.straw/lib/CORE/cv.h b/Master/tlpkg/tlperl.straw/lib/CORE/cv.h new file mode 100755 index 00000000000..24f59023b0a --- /dev/null +++ b/Master/tlpkg/tlperl.straw/lib/CORE/cv.h @@ -0,0 +1,275 @@ +/* cv.h + * + * 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 must the beginning of XPVFM in sv.h */ + +struct xpvcv { + union { + NV xnv_nv; /* numeric value, if any */ + HV * xgv_stash; + struct { + U32 xlow; + U32 xhigh; + } xpad_cop_seq; /* used by pad.c for cop_sequence */ + struct { + U32 xbm_previous; /* how many characters in string before rare? */ + U8 xbm_flags; + U8 xbm_rare; /* rarest character in string */ + } xbm_s; /* fields from PVBM */ + } xnv_u; + STRLEN xpv_cur; /* length of xp_pv as a C string */ + STRLEN xpv_len; /* allocated size */ + union { + IV xivu_iv; + UV xivu_uv; + void * xivu_p1; + I32 xivu_i32; /* depth, >= 2 indicates recursive call */ + HEK * xivu_namehek; + } xiv_u; + union { + MAGIC* xmg_magic; /* linked list of magicalness */ + HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */ + } xmg_u; + HV* xmg_stash; /* class package */ + + HV * xcv_stash; + union { + OP * xcv_start; + ANY xcv_xsubany; + } xcv_start_u; + union { + OP * xcv_root; + void (*xcv_xsub) (pTHX_ CV*); + } xcv_root_u; + GV * xcv_gv; + char * xcv_file; + PADLIST * xcv_padlist; + CV * xcv_outside; + U32 xcv_outside_seq; /* the COP sequence (at the point of our + * compilation) in the lexically enclosing + * sub */ + cv_flags_t xcv_flags; +}; + +typedef struct { + STRLEN xpv_cur; /* length of xp_pv as a C string */ + STRLEN xpv_len; /* allocated size */ + union { + IV xivu_iv; + UV xivu_uv; + void * xivu_p1; + I32 xivu_i32; /* depth, >= 2 indicates recursive call */ + HEK * xivu_namehek; + } xiv_u; + union { + MAGIC* xmg_magic; /* linked list of magicalness */ + HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */ + } xmg_u; + HV* xmg_stash; /* class package */ + + HV * xcv_stash; + union { + OP * xcv_start; + ANY xcv_xsubany; + } xcv_start_u; + union { + OP * xcv_root; + void (*xcv_xsub) (pTHX_ CV*); + } xcv_root_u; + GV * xcv_gv; + char * xcv_file; + PADLIST * xcv_padlist; + CV * xcv_outside; + U32 xcv_outside_seq; /* the COP sequence (at the point of our + * compilation) in the lexically enclosing + * sub */ + cv_flags_t xcv_flags; +} xpvcv_allocated; + +/* +=head1 Handy Values + +=for apidoc AmU||Nullcv +Null CV pointer. + +=head1 CV Manipulation Functions + +=for apidoc Am|HV*|CvSTASH|CV* cv +Returns the stash of the CV. + +=cut +*/ + +#define Nullcv Null(CV*) + +#define CvSTASH(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash +#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) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_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))) +#else +# define CvFILE_set_from_cop(sv, cop) (CvFILE(sv) = CopFILE(cop)) +#endif +#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) +#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN) +# define CvDEPTH(sv) (*({const CV *const _cvdepth = (const CV *)sv; \ + assert(SvTYPE(_cvdepth) == SVt_PVCV); \ + &((XPVCV*)SvANY(_cvdepth))->xiv_u.xivu_i32; \ + })) +#else +# define CvDEPTH(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xiv_u.xivu_i32 +#endif +#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 + +#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ +#define CVf_LOCKED 0x0002 /* CV locks itself or first arg on entry */ +#define CVf_LVALUE 0x0004 /* CV return value can be used as lvalue */ + +#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 /* CvGV() can't be trusted */ +#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_CONST 0x0400 /* inlinable sub */ +#define CVf_ISXSUB 0x0800 /* CV is an XSUB, not pure perl. */ + +/* This symbol for optimised communication between toke.c and op.c: */ +#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LOCKED|CVf_LVALUE) + +#define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) +#define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) +#define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE) + +#define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED) +#define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED) +#define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED) + +#define CvANON(cv) (CvFLAGS(cv) & CVf_ANON) +#define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) +#define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) + +#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) +#define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) +#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) + +#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG) +#define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG) +#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG) + +#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD) +#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) + +#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|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)) + +#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST) +#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) + +/* Flags for newXS_flags */ +#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ + +/* +=head1 CV reference counts and CvOUTSIDE + +=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv + +Each CV has a pointer, C<CvOUTSIDE()>, 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<CvOUTSIDE> in the I<one specific instance> that the parent +has a C<&> pad slot pointing back to us. In this case, we set the +C<CvWEAKOUTSIDE> 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<CvWEAKOUTSIDE> 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 $a is +executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s 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<CvOUTSIDE> 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<undef &foo>. In this case, its refcount may +not have reached zero, but we still delete its pad and its C<CvROOT> etc. +Since various children may still have their C<CvOUTSIDE> pointing at this +undefined CV, we keep its own C<CvOUTSIDE> 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 +*/ + +/* + * Local variables: + * c-indentation-style: bsd + * c-basic-offset: 4 + * indent-tabs-mode: t + * End: + * + * ex: set ts=8 sts=4 sw=4 noet: + */ |