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 | ||
7c60e434 | 11 | /* This structure must the beginning of XPVFM in sv.h */ |
44a8e56a | 12 | |
79072805 | 13 | struct 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 |
23 | Null CV pointer. | |
24 | ||
3ae1b226 NC |
25 | (deprecated - use C<(CV *)NULL> instead) |
26 | ||
ccfc67b7 JH |
27 | =head1 CV Manipulation Functions |
28 | ||
f0b90de1 SF |
29 | This section documents functions to manipulate CVs which are code-values, |
30 | or subroutines. For more information, see L<perlguts>. | |
31 | ||
954c1994 | 32 | =for apidoc Am|HV*|CvSTASH|CV* cv |
f0b90de1 SF |
33 | Returns the stash of the CV. A stash is the symbol table hash, containing |
34 | the package-scoped variables in the package where the subroutine was defined. | |
35 | For 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 | |
5b4563c8 | 74 | #define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ |
c2485e0c NC |
75 | #define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ |
76 | #define CVf_CONST 0x0004 /* inlinable sub */ | |
77 | #define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ | |
5b4563c8 NC |
78 | |
79 | #define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ | |
80 | #define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ | |
81 | #define CVf_CLONED 0x0040 /* a clone of one of those */ | |
cfc1e951 | 82 | #define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ |
5b4563c8 | 83 | #define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, |
1108974d | 84 | * require, eval). */ |
5b4563c8 | 85 | #define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV |
8ebc5c01 | 86 | (esp. useful for special XSUBs) */ |
cfc1e951 | 87 | #define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ |
bad4ae38 | 88 | #define CVf_DYNFILE 0x1000 /* The filename isn't static */ |
7dafbf52 | 89 | |
d3cea301 | 90 | /* This symbol for optimised communication between toke.c and op.c: */ |
e95ab0c0 | 91 | #define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE) |
a5f75d66 AD |
92 | |
93 | #define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) | |
94 | #define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) | |
95 | #define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE) | |
96 | ||
97 | #define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED) | |
98 | #define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED) | |
99 | #define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED) | |
100 | ||
101 | #define CvANON(cv) (CvFLAGS(cv) & CVf_ANON) | |
102 | #define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) | |
103 | #define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) | |
79072805 | 104 | |
07055b4c CS |
105 | #define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) |
106 | #define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) | |
107 | #define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) | |
8ebc5c01 | 108 | |
109 | #define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG) | |
110 | #define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG) | |
111 | #define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG) | |
77a005ab MB |
112 | |
113 | #define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD) | |
114 | #define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD) | |
115 | #define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD) | |
116 | ||
cd06dffe GS |
117 | #define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE) |
118 | #define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE) | |
119 | #define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE) | |
120 | ||
1aff0e91 GS |
121 | #define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv)) |
122 | #define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv)) | |
123 | #define CvEVAL_off(cv) CvUNIQUE_off(cv) | |
124 | ||
3c10abe3 | 125 | /* BEGIN|CHECK|INIT|UNITCHECK|END */ |
1aff0e91 GS |
126 | #define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv)) |
127 | #define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv)) | |
128 | #define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv)) | |
beab0874 JT |
129 | |
130 | #define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST) | |
131 | #define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST) | |
132 | #define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST) | |
a4f1a029 | 133 | |
7dafbf52 DM |
134 | #define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE) |
135 | #define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE) | |
136 | #define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE) | |
137 | ||
d04ba589 NC |
138 | #define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB) |
139 | #define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB) | |
140 | #define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB) | |
141 | ||
cfc1e951 DM |
142 | #define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC) |
143 | #define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC) | |
144 | #define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC) | |
145 | ||
bad4ae38 FC |
146 | #define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE) |
147 | #define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE) | |
148 | #define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE) | |
149 | ||
77004dee NC |
150 | /* Flags for newXS_flags */ |
151 | #define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ | |
152 | ||
7dafbf52 DM |
153 | /* |
154 | =head1 CV reference counts and CvOUTSIDE | |
155 | ||
156 | =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv | |
157 | ||
158 | Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing | |
159 | CV (if any). Because pointers to anonymous sub prototypes are | |
160 | stored in C<&> pad slots, it is a possible to get a circular reference, | |
161 | with the parent pointing to the child and vice-versa. To avoid the | |
162 | ensuing memory leak, we do not increment the reference count of the CV | |
163 | pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent | |
164 | has a C<&> pad slot pointing back to us. In this case, we set the | |
165 | C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what | |
166 | circumstances we should decrement the refcount of the parent when freeing | |
167 | the child. | |
168 | ||
eeb8d49e | 169 | There is a further complication with non-closure anonymous subs (i.e. those |
7dafbf52 DM |
170 | that do not refer to any lexicals outside that sub). In this case, the |
171 | anonymous prototype is shared rather than being cloned. This has the | |
172 | consequence that the parent may be freed while there are still active | |
173 | children, eg | |
174 | ||
175 | BEGIN { $a = sub { eval '$x' } } | |
176 | ||
177 | In this case, the BEGIN is freed immediately after execution since there | |
178 | are no active references to it: the anon sub prototype has | |
179 | C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same | |
180 | CV, so it doesn't contribute to BEGIN's refcount either. When $a is | |
181 | executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, | |
182 | and the freed BEGIN is accessed. | |
183 | ||
184 | To avoid this, whenever a CV and its associated pad is freed, any | |
185 | C<&> entries in the pad are explicitly removed from the pad, and if the | |
186 | refcount of the pointed-to anon sub is still positive, then that | |
187 | child's C<CvOUTSIDE> is set to point to its grandparent. This will only | |
188 | occur in the single specific case of a non-closure anon prototype | |
189 | having one or more active references (such as C<$a> above). | |
190 | ||
191 | One other thing to consider is that a CV may be merely undefined | |
192 | rather than freed, eg C<undef &foo>. In this case, its refcount may | |
193 | not have reached zero, but we still delete its pad and its C<CvROOT> etc. | |
194 | Since various children may still have their C<CvOUTSIDE> pointing at this | |
195 | undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that | |
196 | the chain of lexical scopes is unbroken. For example, the following | |
197 | should print 123: | |
198 | ||
199 | my $x = 123; | |
200 | sub tmp { sub { eval '$x' } } | |
201 | my $a = tmp(); | |
202 | undef &tmp; | |
203 | print $a->(); | |
204 | ||
205 | =cut | |
206 | */ | |
102d3b8a | 207 | |
d9088386 Z |
208 | typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); |
209 | ||
102d3b8a NC |
210 | /* |
211 | * Local variables: | |
212 | * c-indentation-style: bsd | |
213 | * c-basic-offset: 4 | |
214 | * indent-tabs-mode: t | |
215 | * End: | |
216 | * | |
217 | * ex: set ts=8 sts=4 sw=4 noet: | |
218 | */ |