Commit | Line | Data |
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a0d0e21e | 1 | /* cv.h |
79072805 | 2 | * |
1129b882 NC |
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 | |
79072805 LW |
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 | * | |
79072805 LW |
9 | */ |
10 | ||
f653aab7 | 11 | /* This structure must match the beginning of XPVFM in sv.h */ |
44a8e56a | 12 | |
79072805 | 13 | struct xpvcv { |
20f4945e | 14 | _XPV_HEAD; |
20f4945e | 15 | _XPVCV_COMMON; |
79072805 | 16 | }; |
748a9306 | 17 | |
954c1994 | 18 | /* |
f204f8ac KW |
19 | =for apidoc Ayh||CV |
20 | ||
78342678 | 21 | =for apidoc ADmnU||Nullcv |
954c1994 GS |
22 | Null CV pointer. |
23 | ||
3ae1b226 NC |
24 | (deprecated - use C<(CV *)NULL> instead) |
25 | ||
954c1994 | 26 | =for apidoc Am|HV*|CvSTASH|CV* cv |
72d33970 | 27 | Returns the stash of the CV. A stash is the symbol table hash, containing |
f0b90de1 SF |
28 | the package-scoped variables in the package where the subroutine was defined. |
29 | For more information, see L<perlguts>. | |
954c1994 | 30 | |
5b36e945 FC |
31 | This also has a special use with XS AUTOLOAD subs. |
32 | See L<perlguts/Autoloading with XSUBs>. | |
33 | ||
954c1994 GS |
34 | =cut |
35 | */ | |
36 | ||
3ae1b226 NC |
37 | #ifndef PERL_CORE |
38 | # define Nullcv Null(CV*) | |
39 | #endif | |
a5f75d66 | 40 | |
a8b89476 | 41 | #define CvSTASH(sv) (MUTABLE_HV(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash)) |
c68d9564 | 42 | #define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st) |
8f629a87 NC |
43 | #define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start |
44 | #define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root | |
45 | #define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub | |
46 | #define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany | |
c9182d9c | 47 | #define CvGV(sv) Perl_CvGV(aTHX_ (CV *)(sv)) |
b3f91e91 | 48 | #define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv) |
ae77754a | 49 | #define CvHASGV(cv) cBOOL(SvANY(cv)->xcv_gv_u.xcv_gv) |
8f629a87 | 50 | #define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file |
a636914a | 51 | #ifdef USE_ITHREADS |
bad4ae38 FC |
52 | # define CvFILE_set_from_cop(sv, cop) \ |
53 | (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv)) | |
a636914a | 54 | #else |
bad4ae38 FC |
55 | # define CvFILE_set_from_cop(sv, cop) \ |
56 | (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv)) | |
a636914a | 57 | #endif |
9ec2a764 | 58 | #define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) |
74804ad1 | 59 | #define CvDEPTH(sv) (*Perl_CvDEPTH((const CV *)sv)) |
52ec28d5 | 60 | /* For use when you only have a XPVCV*, not a real CV*. |
74804ad1 | 61 | Must be assert protected as in Perl_CvDEPTH before use. */ |
52ec28d5 | 62 | #define CvDEPTHunsafe(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth |
eacbb379 DD |
63 | |
64 | /* these CvPADLIST/CvRESERVED asserts can be reverted one day, once stabilized */ | |
65 | #define CvPADLIST(sv) (*(assert_(!CvISXSUB((CV*)(sv))) \ | |
1604cfb0 | 66 | &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist))) |
eacbb379 DD |
67 | /* CvPADLIST_set is not public API, it can be removed one day, once stabilized */ |
68 | #ifdef DEBUGGING | |
e69651e7 | 69 | # define CvPADLIST_set(sv, padlist) Perl_set_padlist((CV*)sv, padlist) |
eacbb379 DD |
70 | #else |
71 | # define CvPADLIST_set(sv, padlist) (CvPADLIST(sv) = (padlist)) | |
72 | #endif | |
db6e00bd | 73 | #define CvHSCXT(sv) *(assert_(CvISXSUB((CV*)(sv))) \ |
1604cfb0 | 74 | &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_hscxt)) |
eacbb379 DD |
75 | #ifdef DEBUGGING |
76 | # if PTRSIZE == 8 | |
77 | # define PoisonPADLIST(sv) \ | |
78 | (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)UINT64_C(0xEFEFEFEFEFEFEFEF)) | |
79 | # elif PTRSIZE == 4 | |
80 | # define PoisonPADLIST(sv) \ | |
81 | (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)0xEFEFEFEF) | |
82 | # else | |
83 | # error unknown pointer size | |
84 | # endif | |
85 | #else | |
eba7d13f | 86 | # define PoisonPADLIST(sv) NOOP |
eacbb379 DD |
87 | #endif |
88 | ||
52ec28d5 | 89 | #define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside |
8f629a87 | 90 | #define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq |
52ec28d5 | 91 | #define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags |
a5f75d66 | 92 | |
8fa6a409 FC |
93 | /* These two are sometimes called on non-CVs */ |
94 | #define CvPROTO(sv) \ | |
1604cfb0 MS |
95 | ( \ |
96 | SvPOK(sv) \ | |
97 | ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ | |
98 | ? SvEND(sv)+1 : SvPVX_const(sv) \ | |
99 | : NULL \ | |
100 | ) | |
8fa6a409 | 101 | #define CvPROTOLEN(sv) \ |
1604cfb0 MS |
102 | ( \ |
103 | SvPOK(sv) \ | |
104 | ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ | |
105 | ? SvLEN(sv)-SvCUR(sv)-2 \ | |
106 | : SvCUR(sv) \ | |
107 | : 0 \ | |
108 | ) | |
8fa6a409 | 109 | |
ec11e338 PE |
110 | /* CV has the `:method` attribute. This used to be called CVf_METHOD but is |
111 | * renamed to avoid collision with an upcoming feature */ | |
112 | #define CVf_NOWARN_AMBIGUOUS 0x0001 | |
113 | ||
c2485e0c NC |
114 | #define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ |
115 | #define CVf_CONST 0x0004 /* inlinable sub */ | |
116 | #define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ | |
5b4563c8 NC |
117 | |
118 | #define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ | |
119 | #define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ | |
120 | #define CVf_CLONED 0x0040 /* a clone of one of those */ | |
cfc1e951 | 121 | #define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ |
5b4563c8 | 122 | #define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, |
1604cfb0 | 123 | * require, eval). */ |
5b4563c8 | 124 | #define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV |
1604cfb0 | 125 | (esp. useful for special XSUBs) */ |
cfc1e951 | 126 | #define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ |
c6565d4b | 127 | #if defined(PERL_CORE) || defined(PERL_EXT) |
58aef2b3 FC |
128 | # define CVf_SLABBED 0x0800 /* Holds refcount on op slab */ |
129 | #endif | |
f60d17f5 | 130 | #define CVf_DYNFILE 0x1000 /* The filename is malloced */ |
8fa6a409 | 131 | #define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */ |
a0d2bbd5 | 132 | #define CVf_HASEVAL 0x4000 /* contains string eval */ |
b290562e | 133 | #define CVf_NAMED 0x8000 /* Has a name HEK */ |
5bb151a5 | 134 | #define CVf_LEXICAL 0x10000 /* Omit package from name */ |
956dfca8 | 135 | #define CVf_ANONCONST 0x20000 /* :const - create anonconst op */ |
36e6814d | 136 | #define CVf_SIGNATURE 0x40000 /* CV uses a signature */ |
b234f9dc | 137 | #define CVf_REFCOUNTED_ANYSV 0x80000 /* CvXSUBANY().any_sv is refcounted */ |
7dafbf52 | 138 | |
d3cea301 | 139 | /* This symbol for optimised communication between toke.c and op.c: */ |
ec11e338 | 140 | #define CVf_BUILTIN_ATTRS (CVf_NOWARN_AMBIGUOUS|CVf_LVALUE|CVf_ANONCONST) |
a5f75d66 AD |
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 */ |
07055b4c CS |
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) | |
8ebc5c01 | 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) | |
77a005ab | 162 | |
ec11e338 PE |
163 | #define CvNOWARN_AMBIGUOUS(cv) (CvFLAGS(cv) & CVf_NOWARN_AMBIGUOUS) |
164 | #define CvNOWARN_AMBIGUOUS_on(cv) (CvFLAGS(cv) |= CVf_NOWARN_AMBIGUOUS) | |
165 | #define CvNOWARN_AMBIGUOUS_off(cv) (CvFLAGS(cv) &= ~CVf_NOWARN_AMBIGUOUS) | |
77a005ab | 166 | |
cd06dffe GS |
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 */ |
1aff0e91 GS |
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 */ |
1aff0e91 GS |
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)) | |
beab0874 JT |
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 | |
7dafbf52 DM |
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 | ||
d04ba589 NC |
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 | ||
cfc1e951 DM |
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 | ||
58aef2b3 FC |
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 | ||
bad4ae38 FC |
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 | ||
8fa6a409 FC |
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 | ||
a0d2bbd5 FC |
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 | ||
b290562e FC |
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 | ||
5bb151a5 FC |
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 | ||
956dfca8 FC |
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 | ||
36e6814d PE |
227 | #define CvSIGNATURE(cv) (CvFLAGS(cv) & CVf_SIGNATURE) |
228 | #define CvSIGNATURE_on(cv) (CvFLAGS(cv) |= CVf_SIGNATURE) | |
229 | #define CvSIGNATURE_off(cv) (CvFLAGS(cv) &= ~CVf_SIGNATURE) | |
230 | ||
b234f9dc PE |
231 | /* |
232 | ||
233 | =for apidoc m|bool|CvREFCOUNTED_ANYSV|CV *cv | |
234 | ||
235 | If true, indicates that the C<CvXSUBANY(cv).any_sv> member contains an SV | |
236 | pointer whose reference count should be decremented when the CV itself is | |
237 | freed. In addition, C<cv_clone()> will increment the reference count, and | |
238 | C<sv_dup()> will duplicate the entire pointed-to SV if this flag is set. | |
239 | ||
240 | Any CV that wraps an XSUB has an C<ANY> union that the XSUB function is free | |
241 | to use for its own purposes. It may be the case that the code wishes to store | |
242 | an SV in the C<any_sv> member of this union. By setting this flag, this SV | |
243 | reference will be properly reclaimed or duplicated when the CV itself is. | |
244 | ||
245 | =for apidoc m|void|CvREFCOUNTED_ANYSV_on|CV *cv | |
246 | ||
247 | Helper macro to turn on the C<CvREFCOUNTED_ANYSV> flag. | |
248 | ||
249 | =for apidoc m|void|CvREFCOUNTED_ANYSV_off|CV *cv | |
250 | ||
251 | Helper macro to turn off the C<CvREFCOUNTED_ANYSV> flag. | |
434ccf36 DM |
252 | |
253 | =cut | |
b234f9dc PE |
254 | */ |
255 | ||
256 | #define CvREFCOUNTED_ANYSV(cv) (CvFLAGS(cv) & CVf_REFCOUNTED_ANYSV) | |
257 | #define CvREFCOUNTED_ANYSV_on(cv) (CvFLAGS(cv) |= CVf_REFCOUNTED_ANYSV) | |
258 | #define CvREFCOUNTED_ANYSV_off(cv) (CvFLAGS(cv) &= ~CVf_REFCOUNTED_ANYSV) | |
259 | ||
3a276a13 PE |
260 | /* Back-compat */ |
261 | #ifndef PERL_CORE | |
262 | # define CVf_METHOD CVf_NOWARN_AMBIGUOUS | |
263 | # define CvMETHOD(cv) CvNOWARN_AMBIGUOUS(cv) | |
264 | # define CvMETHOD_on(cv) CvNOWARN_AMBIGUOUS_on(cv) | |
ff5bbe67 | 265 | # define CvMETHOD_off(cv) CvNOWARN_AMBIGUOUS_off(cv) |
3a276a13 PE |
266 | #endif |
267 | ||
77004dee NC |
268 | /* Flags for newXS_flags */ |
269 | #define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ | |
270 | ||
b290562e FC |
271 | PERL_STATIC_INLINE HEK * |
272 | CvNAME_HEK(CV *sv) | |
273 | { | |
274 | return CvNAMED(sv) | |
1604cfb0 MS |
275 | ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek |
276 | : 0; | |
b290562e | 277 | } |
79656330 N |
278 | |
279 | /* helper for the common pattern: | |
280 | CvNAMED(sv) ? CvNAME_HEK((CV *)sv) : GvNAME_HEK(CvGV(sv)) | |
281 | */ | |
282 | #define CvGvNAME_HEK(sv) ( \ | |
283 | CvNAMED((CV*)sv) ? \ | |
284 | ((XPVCV*)MUTABLE_PTR(SvANY((SV*)sv)))->xcv_gv_u.xcv_hek\ | |
285 | : GvNAME_HEK(CvGV( (SV*) sv)) \ | |
286 | ) | |
287 | ||
288 | /* This lowers the reference count of the previous value, but does *not* | |
2e800d79 FC |
289 | increment the reference count of the new value. */ |
290 | #define CvNAME_HEK_set(cv, hek) ( \ | |
1604cfb0 MS |
291 | CvNAME_HEK((CV *)(cv)) \ |
292 | ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \ | |
293 | : (void)0, \ | |
294 | ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \ | |
295 | CvNAMED_on(cv) \ | |
2e800d79 | 296 | ) |
b290562e | 297 | |
7dafbf52 | 298 | /* |
7dafbf52 DM |
299 | |
300 | =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv | |
301 | ||
302 | Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing | |
154e47c8 | 303 | CV (if any). Because pointers to anonymous sub prototypes are |
7dafbf52 | 304 | stored in C<&> pad slots, it is a possible to get a circular reference, |
154e47c8 | 305 | with the parent pointing to the child and vice-versa. To avoid the |
7dafbf52 DM |
306 | ensuing memory leak, we do not increment the reference count of the CV |
307 | pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent | |
154e47c8 FC |
308 | has a C<&> pad slot pointing back to us. In this case, we set the |
309 | C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what | |
7dafbf52 DM |
310 | circumstances we should decrement the refcount of the parent when freeing |
311 | the child. | |
312 | ||
eeb8d49e | 313 | There is a further complication with non-closure anonymous subs (i.e. those |
154e47c8 FC |
314 | that do not refer to any lexicals outside that sub). In this case, the |
315 | anonymous prototype is shared rather than being cloned. This has the | |
7dafbf52 | 316 | consequence that the parent may be freed while there are still active |
dfcfced8 | 317 | children, I<e.g.>, |
7dafbf52 DM |
318 | |
319 | BEGIN { $a = sub { eval '$x' } } | |
320 | ||
321 | In this case, the BEGIN is freed immediately after execution since there | |
322 | are no active references to it: the anon sub prototype has | |
323 | C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same | |
324 | CV, so it doesn't contribute to BEGIN's refcount either. When $a is | |
325 | executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, | |
326 | and the freed BEGIN is accessed. | |
327 | ||
328 | To avoid this, whenever a CV and its associated pad is freed, any | |
329 | C<&> entries in the pad are explicitly removed from the pad, and if the | |
330 | refcount of the pointed-to anon sub is still positive, then that | |
154e47c8 | 331 | child's C<CvOUTSIDE> is set to point to its grandparent. This will only |
7dafbf52 DM |
332 | occur in the single specific case of a non-closure anon prototype |
333 | having one or more active references (such as C<$a> above). | |
334 | ||
335 | One other thing to consider is that a CV may be merely undefined | |
154e47c8 | 336 | rather than freed, eg C<undef &foo>. In this case, its refcount may |
7dafbf52 DM |
337 | not have reached zero, but we still delete its pad and its C<CvROOT> etc. |
338 | Since various children may still have their C<CvOUTSIDE> pointing at this | |
339 | undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that | |
154e47c8 | 340 | the chain of lexical scopes is unbroken. For example, the following |
7dafbf52 DM |
341 | should print 123: |
342 | ||
343 | my $x = 123; | |
344 | sub tmp { sub { eval '$x' } } | |
345 | my $a = tmp(); | |
346 | undef &tmp; | |
347 | print $a->(); | |
348 | ||
349 | =cut | |
350 | */ | |
102d3b8a | 351 | |
d9088386 Z |
352 | typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); |
353 | ||
aa38f4b1 FC |
354 | #define CALL_CHECKER_REQUIRE_GV MGf_REQUIRE_GV |
355 | ||
5e881495 FC |
356 | #define CV_NAME_NOTQUAL 1 |
357 | ||
b7acb0a3 FC |
358 | #ifdef PERL_CORE |
359 | # define CV_UNDEF_KEEP_NAME 1 | |
360 | #endif | |
361 | ||
102d3b8a | 362 | /* |
14d04a33 | 363 | * ex: set ts=8 sts=4 sw=4 et: |
102d3b8a | 364 | */ |