This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
[perl #6828] Set $AUTOLOAD once more for XS autoloading
[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
7c60e434 11/* This structure must the beginning of XPVFM in sv.h */
44a8e56a 12
79072805 13struct xpvcv {
20f4945e 14 _XPV_HEAD;
20f4945e 15 _XPVCV_COMMON;
c4648999 16 I32 xcv_depth; /* >= 2 indicates recursive call */
79072805 17};
748a9306 18
954c1994 19/*
ccfc67b7
JH
20=head1 Handy Values
21
954c1994
GS
22=for apidoc AmU||Nullcv
23Null CV pointer.
24
3ae1b226
NC
25(deprecated - use C<(CV *)NULL> instead)
26
ccfc67b7
JH
27=head1 CV Manipulation Functions
28
f0b90de1
SF
29This section documents functions to manipulate CVs which are code-values,
30or subroutines. For more information, see L<perlguts>.
31
954c1994 32=for apidoc Am|HV*|CvSTASH|CV* cv
f0b90de1
SF
33Returns the stash of the CV. A stash is the symbol table hash, containing
34the package-scoped variables in the package where the subroutine was defined.
35For more information, see L<perlguts>.
954c1994
GS
36
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
b3f91e91
DM
50#define CvGV(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv)
51#define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv)
8f629a87 52#define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
a636914a 53#ifdef USE_ITHREADS
bad4ae38
FC
54# define CvFILE_set_from_cop(sv, cop) \
55 (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv))
a636914a 56#else
bad4ae38
FC
57# define CvFILE_set_from_cop(sv, cop) \
58 (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv))
a636914a 59#endif
9ec2a764 60#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv)))
bb172083 61#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
8f629a87 62# define CvDEPTH(sv) (*({const CV *const _cvdepth = (const CV *)sv; \
5129b2ca 63 assert(SvTYPE(_cvdepth) == SVt_PVCV); \
c4648999 64 &((XPVCV*)SvANY(_cvdepth))->xcv_depth; \
bb172083
NC
65 }))
66#else
c4648999 67# define CvDEPTH(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth
bb172083 68#endif
8f629a87
NC
69#define CvPADLIST(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist
70#define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside
71#define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags
72#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq
a5f75d66 73
8fa6a409
FC
74/* These two are sometimes called on non-CVs */
75#define CvPROTO(sv) \
76 ( \
77 SvPOK(sv) \
78 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
79 ? SvEND(sv)+1 : SvPVX_const(sv) \
80 : NULL \
81 )
82#define CvPROTOLEN(sv) \
83 ( \
84 SvPOK(sv) \
85 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
86 ? SvLEN(sv)-SvCUR(sv)-2 \
87 : SvCUR(sv) \
88 : 0 \
89 )
90
5b4563c8 91#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */
c2485e0c
NC
92#define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */
93#define CVf_CONST 0x0004 /* inlinable sub */
94#define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */
5b4563c8
NC
95
96#define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */
97#define CVf_CLONE 0x0020 /* anon CV uses external lexicals */
98#define CVf_CLONED 0x0040 /* a clone of one of those */
cfc1e951 99#define CVf_ANON 0x0080 /* CV is not pointed to by a GV */
5b4563c8 100#define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv,
1108974d 101 * require, eval). */
5b4563c8 102#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV
8ebc5c01 103 (esp. useful for special XSUBs) */
cfc1e951 104#define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */
bad4ae38 105#define CVf_DYNFILE 0x1000 /* The filename isn't static */
8fa6a409 106#define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */
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
07055b4c
CS
123#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE)
124#define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE)
125#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE)
8ebc5c01
PP
126
127#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG)
128#define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG)
129#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG)
77a005ab
MB
130
131#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD)
132#define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD)
133#define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD)
134
cd06dffe
GS
135#define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE)
136#define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE)
137#define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE)
138
1aff0e91
GS
139#define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv))
140#define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv))
141#define CvEVAL_off(cv) CvUNIQUE_off(cv)
142
3c10abe3 143/* BEGIN|CHECK|INIT|UNITCHECK|END */
1aff0e91
GS
144#define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv))
145#define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv))
146#define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv))
beab0874
JT
147
148#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST)
149#define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST)
150#define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST)
a4f1a029 151
7dafbf52
DM
152#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE)
153#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE)
154#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)
155
d04ba589
NC
156#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB)
157#define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB)
158#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB)
159
cfc1e951
DM
160#define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC)
161#define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC)
162#define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC)
163
bad4ae38
FC
164#define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE)
165#define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE)
166#define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE)
167
8fa6a409
FC
168#define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD)
169#define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD)
170#define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD)
171
77004dee
NC
172/* Flags for newXS_flags */
173#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */
174
7dafbf52
DM
175/*
176=head1 CV reference counts and CvOUTSIDE
177
178=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv
179
180Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
181CV (if any). Because pointers to anonymous sub prototypes are
182stored in C<&> pad slots, it is a possible to get a circular reference,
183with the parent pointing to the child and vice-versa. To avoid the
184ensuing memory leak, we do not increment the reference count of the CV
185pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
186has a C<&> pad slot pointing back to us. In this case, we set the
187C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
188circumstances we should decrement the refcount of the parent when freeing
189the child.
190
eeb8d49e 191There is a further complication with non-closure anonymous subs (i.e. those
7dafbf52
DM
192that do not refer to any lexicals outside that sub). In this case, the
193anonymous prototype is shared rather than being cloned. This has the
194consequence that the parent may be freed while there are still active
195children, eg
196
197 BEGIN { $a = sub { eval '$x' } }
198
199In this case, the BEGIN is freed immediately after execution since there
200are no active references to it: the anon sub prototype has
201C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
202CV, so it doesn't contribute to BEGIN's refcount either. When $a is
203executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
204and the freed BEGIN is accessed.
205
206To avoid this, whenever a CV and its associated pad is freed, any
207C<&> entries in the pad are explicitly removed from the pad, and if the
208refcount of the pointed-to anon sub is still positive, then that
209child's C<CvOUTSIDE> is set to point to its grandparent. This will only
210occur in the single specific case of a non-closure anon prototype
211having one or more active references (such as C<$a> above).
212
213One other thing to consider is that a CV may be merely undefined
214rather than freed, eg C<undef &foo>. In this case, its refcount may
215not have reached zero, but we still delete its pad and its C<CvROOT> etc.
216Since various children may still have their C<CvOUTSIDE> pointing at this
217undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
218the chain of lexical scopes is unbroken. For example, the following
219should print 123:
220
221 my $x = 123;
222 sub tmp { sub { eval '$x' } }
223 my $a = tmp();
224 undef &tmp;
225 print $a->();
226
227=cut
228*/
102d3b8a 229
d9088386
Z
230typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *);
231
102d3b8a
NC
232/*
233 * Local variables:
234 * c-indentation-style: bsd
235 * c-basic-offset: 4
236 * indent-tabs-mode: t
237 * End:
238 *
239 * ex: set ts=8 sts=4 sw=4 noet:
240 */