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Move all the FBM data fields from the table into a struct xbm_s which
[perl5.git] / cv.h
CommitLineData
a0d0e21e 1/* cv.h
79072805 2 *
4bb101f2 3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999,
bf53b3a5 4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, by Larry Wall and others
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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 *
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9 */
10
7c60e434 11/* This structure must the beginning of XPVFM in sv.h */
44a8e56a 12
79072805 13struct xpvcv {
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14 union {
15 NV xnv_nv; /* numeric value, if any */
16 HV * xgv_stash;
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17 struct {
18 U32 xlow;
19 U32 xhigh;
20 } xpad_cop_seq; /* used by pad.c for cop_sequence */
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21 struct {
22 U32 xbm_previous; /* how many characters in string before rare? */
23 U8 xbm_flags;
24 U8 xbm_rare; /* rarest character in string */
25 } xbm_s; /* fields from PVBM */
58430790 26 } xnv_u;
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27 STRLEN xpv_cur; /* length of xp_pv as a C string */
28 STRLEN xpv_len; /* allocated size */
e4305a63 29 union {
bb172083 30 IV xivu_iv;
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31 UV xivu_uv;
32 void * xivu_p1;
bb172083 33 I32 xivu_i32; /* depth, >= 2 indicates recursive call */
69ecfd12 34 HEK * xivu_namehek;
311a25d9 35 } xiv_u;
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36 union {
37 MAGIC* xmg_magic; /* linked list of magicalness */
38 HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */
39 } xmg_u;
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40 HV* xmg_stash; /* class package */
41
42 HV * xcv_stash;
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43 union {
44 OP * xcv_start;
45 ANY xcv_xsubany;
46 } xcv_start_u;
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47 union {
48 OP * xcv_root;
49 void (*xcv_xsub) (pTHX_ CV*);
50 } xcv_root_u;
8990e307 51 GV * xcv_gv;
57843af0 52 char * xcv_file;
dd2155a4 53 PADLIST * xcv_padlist;
748a9306 54 CV * xcv_outside;
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55 U32 xcv_outside_seq; /* the COP sequence (at the point of our
56 * compilation) in the lexically enclosing
57 * sub */
bb172083 58 cv_flags_t xcv_flags;
79072805 59};
748a9306 60
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61typedef struct {
62 STRLEN xpv_cur; /* length of xp_pv as a C string */
63 STRLEN xpv_len; /* allocated size */
64 union {
65 IV xivu_iv;
66 UV xivu_uv;
67 void * xivu_p1;
68 I32 xivu_i32; /* depth, >= 2 indicates recursive call */
69ecfd12 69 HEK * xivu_namehek;
c84c4652 70 } xiv_u;
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71 union {
72 MAGIC* xmg_magic; /* linked list of magicalness */
73 HV* xmg_ourstash; /* Stash for our (when SvPAD_OUR is true) */
74 } xmg_u;
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75 HV* xmg_stash; /* class package */
76
77 HV * xcv_stash;
78 union {
79 OP * xcv_start;
80 ANY xcv_xsubany;
81 } xcv_start_u;
82 union {
83 OP * xcv_root;
84 void (*xcv_xsub) (pTHX_ CV*);
85 } xcv_root_u;
86 GV * xcv_gv;
87 char * xcv_file;
88 PADLIST * xcv_padlist;
89 CV * xcv_outside;
90 U32 xcv_outside_seq; /* the COP sequence (at the point of our
91 * compilation) in the lexically enclosing
92 * sub */
93 cv_flags_t xcv_flags;
94} xpvcv_allocated;
95
954c1994 96/*
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97=head1 Handy Values
98
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99=for apidoc AmU||Nullcv
100Null CV pointer.
101
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102=head1 CV Manipulation Functions
103
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104=for apidoc Am|HV*|CvSTASH|CV* cv
105Returns the stash of the CV.
106
107=cut
108*/
109
79072805 110#define Nullcv Null(CV*)
a5f75d66 111
79072805 112#define CvSTASH(sv) ((XPVCV*)SvANY(sv))->xcv_stash
bf53b3a5 113#define CvSTART(sv) ((XPVCV*)SvANY(sv))->xcv_start_u.xcv_start
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114#define CvROOT(sv) ((XPVCV*)SvANY(sv))->xcv_root_u.xcv_root
115#define CvXSUB(sv) ((XPVCV*)SvANY(sv))->xcv_root_u.xcv_xsub
bf53b3a5 116#define CvXSUBANY(sv) ((XPVCV*)SvANY(sv))->xcv_start_u.xcv_xsubany
8990e307 117#define CvGV(sv) ((XPVCV*)SvANY(sv))->xcv_gv
57843af0 118#define CvFILE(sv) ((XPVCV*)SvANY(sv))->xcv_file
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119#ifdef USE_ITHREADS
120# define CvFILE_set_from_cop(sv, cop) (CvFILE(sv) = savepv(CopFILE(cop)))
121#else
122# define CvFILE_set_from_cop(sv, cop) (CvFILE(sv) = CopFILE(cop))
123#endif
9ec2a764 124#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv)))
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125#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
126# define CvDEPTH(sv) (*({const CV *_cv = (CV *)sv; \
127 assert(SvTYPE(_cv) == SVt_PVCV); \
128 &((XPVCV*)SvANY(_cv))->xiv_u.xivu_i32; \
129 }))
130#else
131# define CvDEPTH(sv) ((XPVCV*)SvANY(sv))->xiv_u.xivu_i32
132#endif
79072805 133#define CvPADLIST(sv) ((XPVCV*)SvANY(sv))->xcv_padlist
748a9306 134#define CvOUTSIDE(sv) ((XPVCV*)SvANY(sv))->xcv_outside
a5f75d66 135#define CvFLAGS(sv) ((XPVCV*)SvANY(sv))->xcv_flags
a3985cdc 136#define CvOUTSIDE_SEQ(sv) ((XPVCV*)SvANY(sv))->xcv_outside_seq
a5f75d66 137
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138#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */
139#define CVf_LOCKED 0x0002 /* CV locks itself or first arg on entry */
140#define CVf_LVALUE 0x0004 /* CV return value can be used as lvalue */
141#define CVf_ASSERTION 0x0008 /* CV called only when asserting */
142
143#define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */
144#define CVf_CLONE 0x0020 /* anon CV uses external lexicals */
145#define CVf_CLONED 0x0040 /* a clone of one of those */
146#define CVf_ANON 0x0080 /* CvGV() can't be trusted */
147#define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv,
1108974d 148 * require, eval). */
5b4563c8 149#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV
8ebc5c01 150 (esp. useful for special XSUBs) */
5b4563c8 151#define CVf_CONST 0x0400 /* inlinable sub */
f73ef291 152#define CVf_ISXSUB 0x0800 /* CV is an XSUB, not pure perl. */
7dafbf52 153
d3cea301 154/* This symbol for optimised communication between toke.c and op.c: */
06492da6 155#define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LOCKED|CVf_LVALUE|CVf_ASSERTION)
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156
157#define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE)
158#define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE)
159#define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE)
160
161#define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED)
162#define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED)
163#define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED)
164
165#define CvANON(cv) (CvFLAGS(cv) & CVf_ANON)
166#define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON)
167#define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON)
79072805 168
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169#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE)
170#define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE)
171#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE)
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172
173#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG)
174#define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG)
175#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG)
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176
177#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD)
178#define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD)
179#define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD)
180
181#define CvLOCKED(cv) (CvFLAGS(cv) & CVf_LOCKED)
182#define CvLOCKED_on(cv) (CvFLAGS(cv) |= CVf_LOCKED)
183#define CvLOCKED_off(cv) (CvFLAGS(cv) &= ~CVf_LOCKED)
1aff0e91 184
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185#define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE)
186#define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE)
187#define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE)
188
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189#define CvASSERTION(cv) (CvFLAGS(cv) & CVf_ASSERTION)
190#define CvASSERTION_on(cv) (CvFLAGS(cv) |= CVf_ASSERTION)
191#define CvASSERTION_off(cv) (CvFLAGS(cv) &= ~CVf_ASSERTION)
192
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193#define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv))
194#define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv))
195#define CvEVAL_off(cv) CvUNIQUE_off(cv)
196
3c10abe3 197/* BEGIN|CHECK|INIT|UNITCHECK|END */
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198#define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv))
199#define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv))
200#define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv))
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201
202#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST)
203#define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST)
204#define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST)
a4f1a029 205
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206#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE)
207#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE)
208#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)
209
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210#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB)
211#define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB)
212#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB)
213
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214/* Flags for newXS_flags */
215#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */
216
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217/*
218=head1 CV reference counts and CvOUTSIDE
219
220=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv
221
222Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
223CV (if any). Because pointers to anonymous sub prototypes are
224stored in C<&> pad slots, it is a possible to get a circular reference,
225with the parent pointing to the child and vice-versa. To avoid the
226ensuing memory leak, we do not increment the reference count of the CV
227pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
228has a C<&> pad slot pointing back to us. In this case, we set the
229C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
230circumstances we should decrement the refcount of the parent when freeing
231the child.
232
eeb8d49e 233There is a further complication with non-closure anonymous subs (i.e. those
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234that do not refer to any lexicals outside that sub). In this case, the
235anonymous prototype is shared rather than being cloned. This has the
236consequence that the parent may be freed while there are still active
237children, eg
238
239 BEGIN { $a = sub { eval '$x' } }
240
241In this case, the BEGIN is freed immediately after execution since there
242are no active references to it: the anon sub prototype has
243C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
244CV, so it doesn't contribute to BEGIN's refcount either. When $a is
245executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
246and the freed BEGIN is accessed.
247
248To avoid this, whenever a CV and its associated pad is freed, any
249C<&> entries in the pad are explicitly removed from the pad, and if the
250refcount of the pointed-to anon sub is still positive, then that
251child's C<CvOUTSIDE> is set to point to its grandparent. This will only
252occur in the single specific case of a non-closure anon prototype
253having one or more active references (such as C<$a> above).
254
255One other thing to consider is that a CV may be merely undefined
256rather than freed, eg C<undef &foo>. In this case, its refcount may
257not have reached zero, but we still delete its pad and its C<CvROOT> etc.
258Since various children may still have their C<CvOUTSIDE> pointing at this
259undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
260the chain of lexical scopes is unbroken. For example, the following
261should print 123:
262
263 my $x = 123;
264 sub tmp { sub { eval '$x' } }
265 my $a = tmp();
266 undef &tmp;
267 print $a->();
268
269=cut
270*/
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271
272/*
273 * Local variables:
274 * c-indentation-style: bsd
275 * c-basic-offset: 4
276 * indent-tabs-mode: t
277 * End:
278 *
279 * ex: set ts=8 sts=4 sw=4 noet:
280 */