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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 | /* |
ccfc67b7 JH |
19 | =head1 Handy Values |
20 | ||
954c1994 GS |
21 | =for apidoc AmU||Nullcv |
22 | Null CV pointer. | |
23 | ||
3ae1b226 NC |
24 | (deprecated - use C<(CV *)NULL> instead) |
25 | ||
ccfc67b7 JH |
26 | =head1 CV Manipulation Functions |
27 | ||
f0b90de1 SF |
28 | This section documents functions to manipulate CVs which are code-values, |
29 | or subroutines. For more information, see L<perlguts>. | |
30 | ||
954c1994 | 31 | =for apidoc Am|HV*|CvSTASH|CV* cv |
f0b90de1 SF |
32 | Returns the stash of the CV. A stash is the symbol table hash, containing |
33 | the package-scoped variables in the package where the subroutine was defined. | |
34 | For more information, see L<perlguts>. | |
954c1994 | 35 | |
5b36e945 FC |
36 | This also has a special use with XS AUTOLOAD subs. |
37 | See L<perlguts/Autoloading with XSUBs>. | |
38 | ||
954c1994 GS |
39 | =cut |
40 | */ | |
41 | ||
3ae1b226 NC |
42 | #ifndef PERL_CORE |
43 | # define Nullcv Null(CV*) | |
44 | #endif | |
a5f75d66 | 45 | |
c68d9564 Z |
46 | #define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash) |
47 | #define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st) | |
8f629a87 NC |
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 | |
b290562e | 52 | #define CvGV(sv) S_CvGV((CV *)(sv)) |
b3f91e91 | 53 | #define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv) |
8f629a87 | 54 | #define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file |
a636914a | 55 | #ifdef USE_ITHREADS |
bad4ae38 FC |
56 | # define CvFILE_set_from_cop(sv, cop) \ |
57 | (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv)) | |
a636914a | 58 | #else |
bad4ae38 FC |
59 | # define CvFILE_set_from_cop(sv, cop) \ |
60 | (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv)) | |
a636914a | 61 | #endif |
9ec2a764 | 62 | #define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) |
1afe1db1 | 63 | #define CvDEPTH(sv) (*S_CvDEPTHp((const CV *)sv)) |
8f629a87 NC |
64 | #define CvPADLIST(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist |
65 | #define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside | |
66 | #define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags | |
67 | #define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq | |
a5f75d66 | 68 | |
8fa6a409 FC |
69 | /* These two are sometimes called on non-CVs */ |
70 | #define CvPROTO(sv) \ | |
71 | ( \ | |
72 | SvPOK(sv) \ | |
73 | ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ | |
74 | ? SvEND(sv)+1 : SvPVX_const(sv) \ | |
75 | : NULL \ | |
76 | ) | |
77 | #define CvPROTOLEN(sv) \ | |
78 | ( \ | |
79 | SvPOK(sv) \ | |
80 | ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ | |
81 | ? SvLEN(sv)-SvCUR(sv)-2 \ | |
82 | : SvCUR(sv) \ | |
83 | : 0 \ | |
84 | ) | |
85 | ||
5b4563c8 | 86 | #define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ |
c2485e0c NC |
87 | #define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ |
88 | #define CVf_CONST 0x0004 /* inlinable sub */ | |
89 | #define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ | |
5b4563c8 NC |
90 | |
91 | #define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ | |
92 | #define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ | |
93 | #define CVf_CLONED 0x0040 /* a clone of one of those */ | |
cfc1e951 | 94 | #define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ |
5b4563c8 | 95 | #define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, |
1108974d | 96 | * require, eval). */ |
5b4563c8 | 97 | #define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV |
8ebc5c01 | 98 | (esp. useful for special XSUBs) */ |
cfc1e951 | 99 | #define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ |
58aef2b3 FC |
100 | #ifdef PERL_CORE |
101 | # define CVf_SLABBED 0x0800 /* Holds refcount on op slab */ | |
102 | #endif | |
bad4ae38 | 103 | #define CVf_DYNFILE 0x1000 /* The filename isn't static */ |
8fa6a409 | 104 | #define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */ |
a0d2bbd5 | 105 | #define CVf_HASEVAL 0x4000 /* contains string eval */ |
b290562e | 106 | #define CVf_NAMED 0x8000 /* Has a name HEK */ |
7dafbf52 | 107 | |
d3cea301 | 108 | /* This symbol for optimised communication between toke.c and op.c: */ |
e95ab0c0 | 109 | #define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE) |
a5f75d66 AD |
110 | |
111 | #define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) | |
112 | #define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) | |
113 | #define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE) | |
114 | ||
115 | #define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED) | |
116 | #define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED) | |
117 | #define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED) | |
118 | ||
119 | #define CvANON(cv) (CvFLAGS(cv) & CVf_ANON) | |
120 | #define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) | |
121 | #define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) | |
79072805 | 122 | |
a2278b6a | 123 | /* CvEVAL or CvSPECIAL */ |
07055b4c CS |
124 | #define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) |
125 | #define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) | |
126 | #define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) | |
8ebc5c01 | 127 | |
128 | #define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG) | |
129 | #define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG) | |
130 | #define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG) | |
77a005ab MB |
131 | |
132 | #define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD) | |
133 | #define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD) | |
134 | #define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD) | |
135 | ||
cd06dffe GS |
136 | #define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE) |
137 | #define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE) | |
138 | #define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE) | |
139 | ||
a2278b6a | 140 | /* eval or PL_main_cv */ |
1aff0e91 GS |
141 | #define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv)) |
142 | #define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv)) | |
143 | #define CvEVAL_off(cv) CvUNIQUE_off(cv) | |
144 | ||
3c10abe3 | 145 | /* BEGIN|CHECK|INIT|UNITCHECK|END */ |
1aff0e91 GS |
146 | #define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv)) |
147 | #define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv)) | |
148 | #define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv)) | |
beab0874 JT |
149 | |
150 | #define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST) | |
151 | #define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST) | |
152 | #define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST) | |
a4f1a029 | 153 | |
7dafbf52 DM |
154 | #define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE) |
155 | #define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE) | |
156 | #define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE) | |
157 | ||
d04ba589 NC |
158 | #define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB) |
159 | #define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB) | |
160 | #define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB) | |
161 | ||
cfc1e951 DM |
162 | #define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC) |
163 | #define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC) | |
164 | #define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC) | |
165 | ||
58aef2b3 FC |
166 | #ifdef PERL_CORE |
167 | # define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED) | |
168 | # define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED) | |
169 | # define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED) | |
170 | #endif | |
171 | ||
bad4ae38 FC |
172 | #define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE) |
173 | #define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE) | |
174 | #define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE) | |
175 | ||
8fa6a409 FC |
176 | #define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD) |
177 | #define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD) | |
178 | #define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD) | |
179 | ||
a0d2bbd5 FC |
180 | #define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL) |
181 | #define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL) | |
182 | #define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL) | |
183 | ||
b290562e FC |
184 | #define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED) |
185 | #define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED) | |
186 | #define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED) | |
187 | ||
77004dee NC |
188 | /* Flags for newXS_flags */ |
189 | #define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ | |
190 | ||
b290562e FC |
191 | PERL_STATIC_INLINE GV * |
192 | S_CvGV(CV *sv) | |
193 | { | |
194 | return CvNAMED(sv) | |
195 | ? 0 | |
196 | : ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_gv; | |
197 | } | |
198 | PERL_STATIC_INLINE HEK * | |
199 | CvNAME_HEK(CV *sv) | |
200 | { | |
201 | return CvNAMED(sv) | |
202 | ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek | |
203 | : 0; | |
204 | } | |
2e800d79 FC |
205 | /* This lowers the refernce count of the previous value, but does *not* |
206 | increment the reference count of the new value. */ | |
207 | #define CvNAME_HEK_set(cv, hek) ( \ | |
208 | CvNAME_HEK((CV *)(cv)) \ | |
209 | ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \ | |
210 | : (void)0, \ | |
211 | ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \ | |
212 | CvNAMED_on(cv) \ | |
213 | ) | |
b290562e | 214 | |
7dafbf52 DM |
215 | /* |
216 | =head1 CV reference counts and CvOUTSIDE | |
217 | ||
218 | =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv | |
219 | ||
220 | Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing | |
221 | CV (if any). Because pointers to anonymous sub prototypes are | |
222 | stored in C<&> pad slots, it is a possible to get a circular reference, | |
223 | with the parent pointing to the child and vice-versa. To avoid the | |
224 | ensuing memory leak, we do not increment the reference count of the CV | |
225 | pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent | |
226 | has a C<&> pad slot pointing back to us. In this case, we set the | |
227 | C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what | |
228 | circumstances we should decrement the refcount of the parent when freeing | |
229 | the child. | |
230 | ||
eeb8d49e | 231 | There is a further complication with non-closure anonymous subs (i.e. those |
7dafbf52 DM |
232 | that do not refer to any lexicals outside that sub). In this case, the |
233 | anonymous prototype is shared rather than being cloned. This has the | |
234 | consequence that the parent may be freed while there are still active | |
235 | children, eg | |
236 | ||
237 | BEGIN { $a = sub { eval '$x' } } | |
238 | ||
239 | In this case, the BEGIN is freed immediately after execution since there | |
240 | are no active references to it: the anon sub prototype has | |
241 | C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same | |
242 | CV, so it doesn't contribute to BEGIN's refcount either. When $a is | |
243 | executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, | |
244 | and the freed BEGIN is accessed. | |
245 | ||
246 | To avoid this, whenever a CV and its associated pad is freed, any | |
247 | C<&> entries in the pad are explicitly removed from the pad, and if the | |
248 | refcount of the pointed-to anon sub is still positive, then that | |
249 | child's C<CvOUTSIDE> is set to point to its grandparent. This will only | |
250 | occur in the single specific case of a non-closure anon prototype | |
251 | having one or more active references (such as C<$a> above). | |
252 | ||
253 | One other thing to consider is that a CV may be merely undefined | |
254 | rather than freed, eg C<undef &foo>. In this case, its refcount may | |
255 | not have reached zero, but we still delete its pad and its C<CvROOT> etc. | |
256 | Since various children may still have their C<CvOUTSIDE> pointing at this | |
257 | undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that | |
258 | the chain of lexical scopes is unbroken. For example, the following | |
259 | should print 123: | |
260 | ||
261 | my $x = 123; | |
262 | sub tmp { sub { eval '$x' } } | |
263 | my $a = tmp(); | |
264 | undef &tmp; | |
265 | print $a->(); | |
266 | ||
267 | =cut | |
268 | */ | |
102d3b8a | 269 | |
d9088386 Z |
270 | typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); |
271 | ||
102d3b8a NC |
272 | /* |
273 | * Local variables: | |
274 | * c-indentation-style: bsd | |
275 | * c-basic-offset: 4 | |
14d04a33 | 276 | * indent-tabs-mode: nil |
102d3b8a NC |
277 | * End: |
278 | * | |
14d04a33 | 279 | * ex: set ts=8 sts=4 sw=4 et: |
102d3b8a | 280 | */ |