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a0d0e21e 1/* cv.h
79072805 2 *
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3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
4 * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
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9 */
10
f653aab7 11/* This structure must match the beginning of XPVFM in sv.h */
44a8e56a 12
79072805 13struct xpvcv {
20f4945e 14 _XPV_HEAD;
20f4945e 15 _XPVCV_COMMON;
79072805 16};
748a9306 17
954c1994 18/*
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19=head1 CV Handling
20
21This section documents functions to manipulate CVs which are code-values,
22meaning subroutines. For more information, see L<perlguts>.
ccfc67b7 23
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24=for apidoc Ayh||CV
25
78342678 26=for apidoc ADmnU||Nullcv
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27Null CV pointer.
28
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29(deprecated - use C<(CV *)NULL> instead)
30
954c1994 31=for apidoc Am|HV*|CvSTASH|CV* cv
72d33970 32Returns the stash of the CV. A stash is the symbol table hash, containing
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33the package-scoped variables in the package where the subroutine was defined.
34For more information, see L<perlguts>.
954c1994 35
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36This also has a special use with XS AUTOLOAD subs.
37See L<perlguts/Autoloading with XSUBs>.
38
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39=cut
40*/
41
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42#ifndef PERL_CORE
43# define Nullcv Null(CV*)
44#endif
a5f75d66 45
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46#define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash)
47#define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st)
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48#define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start
49#define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root
50#define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub
51#define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany
c9182d9c 52#define CvGV(sv) Perl_CvGV(aTHX_ (CV *)(sv))
b3f91e91 53#define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv)
ae77754a 54#define CvHASGV(cv) cBOOL(SvANY(cv)->xcv_gv_u.xcv_gv)
8f629a87 55#define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
a636914a 56#ifdef USE_ITHREADS
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57# define CvFILE_set_from_cop(sv, cop) \
58 (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv))
a636914a 59#else
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60# define CvFILE_set_from_cop(sv, cop) \
61 (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv))
a636914a 62#endif
9ec2a764 63#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv)))
74804ad1 64#define CvDEPTH(sv) (*Perl_CvDEPTH((const CV *)sv))
52ec28d5 65/* For use when you only have a XPVCV*, not a real CV*.
74804ad1 66 Must be assert protected as in Perl_CvDEPTH before use. */
52ec28d5 67#define CvDEPTHunsafe(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth
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68
69/* these CvPADLIST/CvRESERVED asserts can be reverted one day, once stabilized */
70#define CvPADLIST(sv) (*(assert_(!CvISXSUB((CV*)(sv))) \
71 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist)))
72/* CvPADLIST_set is not public API, it can be removed one day, once stabilized */
73#ifdef DEBUGGING
e69651e7 74# define CvPADLIST_set(sv, padlist) Perl_set_padlist((CV*)sv, padlist)
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75#else
76# define CvPADLIST_set(sv, padlist) (CvPADLIST(sv) = (padlist))
77#endif
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78#define CvHSCXT(sv) *(assert_(CvISXSUB((CV*)(sv))) \
79 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_hscxt))
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80#ifdef DEBUGGING
81# if PTRSIZE == 8
82# define PoisonPADLIST(sv) \
83 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)UINT64_C(0xEFEFEFEFEFEFEFEF))
84# elif PTRSIZE == 4
85# define PoisonPADLIST(sv) \
86 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)0xEFEFEFEF)
87# else
88# error unknown pointer size
89# endif
90#else
eba7d13f 91# define PoisonPADLIST(sv) NOOP
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92#endif
93
52ec28d5 94#define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside
8f629a87 95#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq
52ec28d5 96#define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags
a5f75d66 97
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98/* These two are sometimes called on non-CVs */
99#define CvPROTO(sv) \
100 ( \
101 SvPOK(sv) \
102 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
103 ? SvEND(sv)+1 : SvPVX_const(sv) \
104 : NULL \
105 )
106#define CvPROTOLEN(sv) \
107 ( \
108 SvPOK(sv) \
109 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
110 ? SvLEN(sv)-SvCUR(sv)-2 \
111 : SvCUR(sv) \
112 : 0 \
113 )
114
5b4563c8 115#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */
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116#define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */
117#define CVf_CONST 0x0004 /* inlinable sub */
118#define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */
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119
120#define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */
121#define CVf_CLONE 0x0020 /* anon CV uses external lexicals */
122#define CVf_CLONED 0x0040 /* a clone of one of those */
cfc1e951 123#define CVf_ANON 0x0080 /* CV is not pointed to by a GV */
5b4563c8 124#define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv,
1108974d 125 * require, eval). */
5b4563c8 126#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV
8ebc5c01 127 (esp. useful for special XSUBs) */
cfc1e951 128#define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */
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129#ifdef PERL_CORE
130# define CVf_SLABBED 0x0800 /* Holds refcount on op slab */
131#endif
f60d17f5 132#define CVf_DYNFILE 0x1000 /* The filename is malloced */
8fa6a409 133#define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */
a0d2bbd5 134#define CVf_HASEVAL 0x4000 /* contains string eval */
b290562e 135#define CVf_NAMED 0x8000 /* Has a name HEK */
5bb151a5 136#define CVf_LEXICAL 0x10000 /* Omit package from name */
956dfca8 137#define CVf_ANONCONST 0x20000 /* :const - create anonconst op */
7dafbf52 138
d3cea301 139/* This symbol for optimised communication between toke.c and op.c: */
956dfca8 140#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE|CVf_ANONCONST)
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141
142#define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE)
143#define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE)
144#define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE)
145
146#define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED)
147#define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED)
148#define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED)
149
150#define CvANON(cv) (CvFLAGS(cv) & CVf_ANON)
151#define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON)
152#define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON)
79072805 153
a2278b6a 154/* CvEVAL or CvSPECIAL */
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155#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE)
156#define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE)
157#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE)
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158
159#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG)
160#define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG)
161#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG)
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162
163#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD)
164#define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD)
165#define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD)
166
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167#define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE)
168#define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE)
169#define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE)
170
a2278b6a 171/* eval or PL_main_cv */
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172#define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv))
173#define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv))
174#define CvEVAL_off(cv) CvUNIQUE_off(cv)
175
3c10abe3 176/* BEGIN|CHECK|INIT|UNITCHECK|END */
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177#define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv))
178#define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv))
179#define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv))
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180
181#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST)
182#define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST)
183#define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST)
a4f1a029 184
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185#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE)
186#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE)
187#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)
188
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189#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB)
190#define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB)
191#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB)
192
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193#define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC)
194#define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC)
195#define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC)
196
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197#ifdef PERL_CORE
198# define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED)
199# define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED)
200# define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED)
201#endif
202
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203#define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE)
204#define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE)
205#define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE)
206
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207#define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD)
208#define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD)
209#define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD)
210
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211#define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL)
212#define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL)
213#define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL)
214
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215#define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED)
216#define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED)
217#define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED)
218
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219#define CvLEXICAL(cv) (CvFLAGS(cv) & CVf_LEXICAL)
220#define CvLEXICAL_on(cv) (CvFLAGS(cv) |= CVf_LEXICAL)
221#define CvLEXICAL_off(cv) (CvFLAGS(cv) &= ~CVf_LEXICAL)
222
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223#define CvANONCONST(cv) (CvFLAGS(cv) & CVf_ANONCONST)
224#define CvANONCONST_on(cv) (CvFLAGS(cv) |= CVf_ANONCONST)
225#define CvANONCONST_off(cv) (CvFLAGS(cv) &= ~CVf_ANONCONST)
226
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227/* Flags for newXS_flags */
228#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */
229
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230PERL_STATIC_INLINE HEK *
231CvNAME_HEK(CV *sv)
232{
233 return CvNAMED(sv)
234 ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek
235 : 0;
236}
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237
238/* helper for the common pattern:
239 CvNAMED(sv) ? CvNAME_HEK((CV *)sv) : GvNAME_HEK(CvGV(sv))
240*/
241#define CvGvNAME_HEK(sv) ( \
242 CvNAMED((CV*)sv) ? \
243 ((XPVCV*)MUTABLE_PTR(SvANY((SV*)sv)))->xcv_gv_u.xcv_hek\
244 : GvNAME_HEK(CvGV( (SV*) sv)) \
245 )
246
247/* This lowers the reference count of the previous value, but does *not*
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248 increment the reference count of the new value. */
249#define CvNAME_HEK_set(cv, hek) ( \
250 CvNAME_HEK((CV *)(cv)) \
251 ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \
252 : (void)0, \
253 ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \
254 CvNAMED_on(cv) \
255 )
b290562e 256
7dafbf52 257/*
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258
259=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv
260
261Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
154e47c8 262CV (if any). Because pointers to anonymous sub prototypes are
7dafbf52 263stored in C<&> pad slots, it is a possible to get a circular reference,
154e47c8 264with the parent pointing to the child and vice-versa. To avoid the
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265ensuing memory leak, we do not increment the reference count of the CV
266pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
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267has a C<&> pad slot pointing back to us. In this case, we set the
268C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
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269circumstances we should decrement the refcount of the parent when freeing
270the child.
271
eeb8d49e 272There is a further complication with non-closure anonymous subs (i.e. those
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273that do not refer to any lexicals outside that sub). In this case, the
274anonymous prototype is shared rather than being cloned. This has the
7dafbf52 275consequence that the parent may be freed while there are still active
dfcfced8 276children, I<e.g.>,
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277
278 BEGIN { $a = sub { eval '$x' } }
279
280In this case, the BEGIN is freed immediately after execution since there
281are no active references to it: the anon sub prototype has
282C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
283CV, so it doesn't contribute to BEGIN's refcount either. When $a is
284executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
285and the freed BEGIN is accessed.
286
287To avoid this, whenever a CV and its associated pad is freed, any
288C<&> entries in the pad are explicitly removed from the pad, and if the
289refcount of the pointed-to anon sub is still positive, then that
154e47c8 290child's C<CvOUTSIDE> is set to point to its grandparent. This will only
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291occur in the single specific case of a non-closure anon prototype
292having one or more active references (such as C<$a> above).
293
294One other thing to consider is that a CV may be merely undefined
154e47c8 295rather than freed, eg C<undef &foo>. In this case, its refcount may
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296not have reached zero, but we still delete its pad and its C<CvROOT> etc.
297Since various children may still have their C<CvOUTSIDE> pointing at this
298undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
154e47c8 299the chain of lexical scopes is unbroken. For example, the following
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300should print 123:
301
302 my $x = 123;
303 sub tmp { sub { eval '$x' } }
304 my $a = tmp();
305 undef &tmp;
306 print $a->();
307
308=cut
309*/
102d3b8a 310
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311typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *);
312
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313#define CALL_CHECKER_REQUIRE_GV MGf_REQUIRE_GV
314
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315#define CV_NAME_NOTQUAL 1
316
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317#ifdef PERL_CORE
318# define CV_UNDEF_KEEP_NAME 1
319#endif
320
102d3b8a 321/*
14d04a33 322 * ex: set ts=8 sts=4 sw=4 et:
102d3b8a 323 */