This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
gv.c: Note GV is documented here
[perl5.git] / cv.h
CommitLineData
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 13struct xpvcv {
20f4945e 14 _XPV_HEAD;
20f4945e 15 _XPVCV_COMMON;
79072805 16};
748a9306 17
954c1994 18/*
51b56f5c
KW
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
78342678 24=for apidoc ADmnU||Nullcv
954c1994
GS
25Null CV pointer.
26
3ae1b226
NC
27(deprecated - use C<(CV *)NULL> instead)
28
954c1994 29=for apidoc Am|HV*|CvSTASH|CV* cv
72d33970 30Returns the stash of the CV. A stash is the symbol table hash, containing
f0b90de1
SF
31the package-scoped variables in the package where the subroutine was defined.
32For more information, see L<perlguts>.
954c1994 33
5b36e945
FC
34This also has a special use with XS AUTOLOAD subs.
35See L<perlguts/Autoloading with XSUBs>.
36
954c1994
GS
37=cut
38*/
39
3ae1b226
NC
40#ifndef PERL_CORE
41# define Nullcv Null(CV*)
42#endif
a5f75d66 43
c68d9564
Z
44#define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash)
45#define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st)
8f629a87
NC
46#define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start
47#define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root
48#define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub
49#define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany
c9182d9c 50#define CvGV(sv) Perl_CvGV(aTHX_ (CV *)(sv))
b3f91e91 51#define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv)
ae77754a 52#define CvHASGV(cv) cBOOL(SvANY(cv)->xcv_gv_u.xcv_gv)
8f629a87 53#define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
a636914a 54#ifdef USE_ITHREADS
bad4ae38
FC
55# define CvFILE_set_from_cop(sv, cop) \
56 (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv))
a636914a 57#else
bad4ae38
FC
58# define CvFILE_set_from_cop(sv, cop) \
59 (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv))
a636914a 60#endif
9ec2a764 61#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv)))
74804ad1 62#define CvDEPTH(sv) (*Perl_CvDEPTH((const CV *)sv))
52ec28d5 63/* For use when you only have a XPVCV*, not a real CV*.
74804ad1 64 Must be assert protected as in Perl_CvDEPTH before use. */
52ec28d5 65#define CvDEPTHunsafe(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth
eacbb379
DD
66
67/* these CvPADLIST/CvRESERVED asserts can be reverted one day, once stabilized */
68#define CvPADLIST(sv) (*(assert_(!CvISXSUB((CV*)(sv))) \
69 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist)))
70/* CvPADLIST_set is not public API, it can be removed one day, once stabilized */
71#ifdef DEBUGGING
e69651e7 72# define CvPADLIST_set(sv, padlist) Perl_set_padlist((CV*)sv, padlist)
eacbb379
DD
73#else
74# define CvPADLIST_set(sv, padlist) (CvPADLIST(sv) = (padlist))
75#endif
db6e00bd
DD
76#define CvHSCXT(sv) *(assert_(CvISXSUB((CV*)(sv))) \
77 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_hscxt))
eacbb379
DD
78#ifdef DEBUGGING
79# if PTRSIZE == 8
80# define PoisonPADLIST(sv) \
81 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)UINT64_C(0xEFEFEFEFEFEFEFEF))
82# elif PTRSIZE == 4
83# define PoisonPADLIST(sv) \
84 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)0xEFEFEFEF)
85# else
86# error unknown pointer size
87# endif
88#else
eba7d13f 89# define PoisonPADLIST(sv) NOOP
eacbb379
DD
90#endif
91
52ec28d5 92#define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside
8f629a87 93#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq
52ec28d5 94#define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags
a5f75d66 95
8fa6a409
FC
96/* These two are sometimes called on non-CVs */
97#define CvPROTO(sv) \
98 ( \
99 SvPOK(sv) \
100 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
101 ? SvEND(sv)+1 : SvPVX_const(sv) \
102 : NULL \
103 )
104#define CvPROTOLEN(sv) \
105 ( \
106 SvPOK(sv) \
107 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
108 ? SvLEN(sv)-SvCUR(sv)-2 \
109 : SvCUR(sv) \
110 : 0 \
111 )
112
5b4563c8 113#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */
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,
1108974d 123 * require, eval). */
5b4563c8 124#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV
8ebc5c01 125 (esp. useful for special XSUBs) */
cfc1e951 126#define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */
58aef2b3
FC
127#ifdef PERL_CORE
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 */
7dafbf52 136
d3cea301 137/* This symbol for optimised communication between toke.c and op.c: */
956dfca8 138#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE|CVf_ANONCONST)
a5f75d66
AD
139
140#define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE)
141#define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE)
142#define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE)
143
144#define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED)
145#define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED)
146#define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED)
147
148#define CvANON(cv) (CvFLAGS(cv) & CVf_ANON)
149#define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON)
150#define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON)
79072805 151
a2278b6a 152/* CvEVAL or CvSPECIAL */
07055b4c
CS
153#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE)
154#define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE)
155#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE)
8ebc5c01
PP
156
157#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG)
158#define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG)
159#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG)
77a005ab
MB
160
161#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD)
162#define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD)
163#define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD)
164
cd06dffe
GS
165#define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE)
166#define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE)
167#define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE)
168
a2278b6a 169/* eval or PL_main_cv */
1aff0e91
GS
170#define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv))
171#define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv))
172#define CvEVAL_off(cv) CvUNIQUE_off(cv)
173
3c10abe3 174/* BEGIN|CHECK|INIT|UNITCHECK|END */
1aff0e91
GS
175#define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv))
176#define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv))
177#define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv))
beab0874
JT
178
179#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST)
180#define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST)
181#define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST)
a4f1a029 182
7dafbf52
DM
183#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE)
184#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE)
185#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)
186
d04ba589
NC
187#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB)
188#define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB)
189#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB)
190
cfc1e951
DM
191#define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC)
192#define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC)
193#define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC)
194
58aef2b3
FC
195#ifdef PERL_CORE
196# define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED)
197# define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED)
198# define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED)
199#endif
200
bad4ae38
FC
201#define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE)
202#define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE)
203#define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE)
204
8fa6a409
FC
205#define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD)
206#define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD)
207#define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD)
208
a0d2bbd5
FC
209#define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL)
210#define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL)
211#define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL)
212
b290562e
FC
213#define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED)
214#define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED)
215#define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED)
216
5bb151a5
FC
217#define CvLEXICAL(cv) (CvFLAGS(cv) & CVf_LEXICAL)
218#define CvLEXICAL_on(cv) (CvFLAGS(cv) |= CVf_LEXICAL)
219#define CvLEXICAL_off(cv) (CvFLAGS(cv) &= ~CVf_LEXICAL)
220
956dfca8
FC
221#define CvANONCONST(cv) (CvFLAGS(cv) & CVf_ANONCONST)
222#define CvANONCONST_on(cv) (CvFLAGS(cv) |= CVf_ANONCONST)
223#define CvANONCONST_off(cv) (CvFLAGS(cv) &= ~CVf_ANONCONST)
224
77004dee
NC
225/* Flags for newXS_flags */
226#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */
227
b290562e
FC
228PERL_STATIC_INLINE HEK *
229CvNAME_HEK(CV *sv)
230{
231 return CvNAMED(sv)
232 ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek
233 : 0;
234}
79656330
N
235
236/* helper for the common pattern:
237 CvNAMED(sv) ? CvNAME_HEK((CV *)sv) : GvNAME_HEK(CvGV(sv))
238*/
239#define CvGvNAME_HEK(sv) ( \
240 CvNAMED((CV*)sv) ? \
241 ((XPVCV*)MUTABLE_PTR(SvANY((SV*)sv)))->xcv_gv_u.xcv_hek\
242 : GvNAME_HEK(CvGV( (SV*) sv)) \
243 )
244
245/* This lowers the reference count of the previous value, but does *not*
2e800d79
FC
246 increment the reference count of the new value. */
247#define CvNAME_HEK_set(cv, hek) ( \
248 CvNAME_HEK((CV *)(cv)) \
249 ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \
250 : (void)0, \
251 ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \
252 CvNAMED_on(cv) \
253 )
b290562e 254
7dafbf52 255/*
7dafbf52
DM
256
257=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv
258
259Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
154e47c8 260CV (if any). Because pointers to anonymous sub prototypes are
7dafbf52 261stored in C<&> pad slots, it is a possible to get a circular reference,
154e47c8 262with the parent pointing to the child and vice-versa. To avoid the
7dafbf52
DM
263ensuing memory leak, we do not increment the reference count of the CV
264pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
154e47c8
FC
265has a C<&> pad slot pointing back to us. In this case, we set the
266C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
7dafbf52
DM
267circumstances we should decrement the refcount of the parent when freeing
268the child.
269
eeb8d49e 270There is a further complication with non-closure anonymous subs (i.e. those
154e47c8
FC
271that do not refer to any lexicals outside that sub). In this case, the
272anonymous prototype is shared rather than being cloned. This has the
7dafbf52 273consequence that the parent may be freed while there are still active
dfcfced8 274children, I<e.g.>,
7dafbf52
DM
275
276 BEGIN { $a = sub { eval '$x' } }
277
278In this case, the BEGIN is freed immediately after execution since there
279are no active references to it: the anon sub prototype has
280C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
281CV, so it doesn't contribute to BEGIN's refcount either. When $a is
282executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
283and the freed BEGIN is accessed.
284
285To avoid this, whenever a CV and its associated pad is freed, any
286C<&> entries in the pad are explicitly removed from the pad, and if the
287refcount of the pointed-to anon sub is still positive, then that
154e47c8 288child's C<CvOUTSIDE> is set to point to its grandparent. This will only
7dafbf52
DM
289occur in the single specific case of a non-closure anon prototype
290having one or more active references (such as C<$a> above).
291
292One other thing to consider is that a CV may be merely undefined
154e47c8 293rather than freed, eg C<undef &foo>. In this case, its refcount may
7dafbf52
DM
294not have reached zero, but we still delete its pad and its C<CvROOT> etc.
295Since various children may still have their C<CvOUTSIDE> pointing at this
296undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
154e47c8 297the chain of lexical scopes is unbroken. For example, the following
7dafbf52
DM
298should print 123:
299
300 my $x = 123;
301 sub tmp { sub { eval '$x' } }
302 my $a = tmp();
303 undef &tmp;
304 print $a->();
305
306=cut
307*/
102d3b8a 308
d9088386
Z
309typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *);
310
aa38f4b1
FC
311#define CALL_CHECKER_REQUIRE_GV MGf_REQUIRE_GV
312
5e881495
FC
313#define CV_NAME_NOTQUAL 1
314
b7acb0a3
FC
315#ifdef PERL_CORE
316# define CV_UNDEF_KEEP_NAME 1
317#endif
318
102d3b8a 319/*
14d04a33 320 * ex: set ts=8 sts=4 sw=4 et:
102d3b8a 321 */