1 /* cv.h 2 * 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 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 * 9 */ 10 11 /* This structure must match the beginning of XPVFM in sv.h */ 12 13 struct xpvcv { 14 _XPV_HEAD; 15 _XPVCV_COMMON; 16 }; 17 18 /* 19 =head1 Handy Values 20 21 =for apidoc ADmnU||Nullcv 22 Null CV pointer. 23 24 (deprecated - use C<(CV *)NULL> instead) 25 26 =head1 CV Manipulation Functions 27 28 This section documents functions to manipulate CVs which are code-values, 29 or subroutines. For more information, see L<perlguts>. 30 31 =for apidoc Am|HV*|CvSTASH|CV* cv 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>. 35 36 This also has a special use with XS AUTOLOAD subs. 37 See L<perlguts/Autoloading with XSUBs>. 38 39 =cut 40 */ 41 42 #ifndef PERL_CORE 43 # define Nullcv Null(CV*) 44 #endif 45 46 #define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash) 47 #define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st) 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 52 #define CvGV(sv) Perl_CvGV(aTHX_ (CV *)(sv)) 53 #define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv) 54 #define CvHASGV(cv) cBOOL(SvANY(cv)->xcv_gv_u.xcv_gv) 55 #define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file 56 #ifdef USE_ITHREADS 57 # define CvFILE_set_from_cop(sv, cop) \ 58 (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv)) 59 #else 60 # define CvFILE_set_from_cop(sv, cop) \ 61 (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv)) 62 #endif 63 #define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) 64 #define CvDEPTH(sv) (*Perl_CvDEPTH((const CV *)sv)) 65 /* For use when you only have a XPVCV*, not a real CV*. 66 Must be assert protected as in Perl_CvDEPTH before use. */ 67 #define CvDEPTHunsafe(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth 68 69 /* these CvPADLIST/CvRESERVED asserts can be reverted one day, once stabilized */ 70 #define CvPADLIST(sv) (*(assert_(!CvISXSUB((CV*)(sv))) \ 71 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist))) 72 /* CvPADLIST_set is not public API, it can be removed one day, once stabilized */ 73 #ifdef DEBUGGING 74 # define CvPADLIST_set(sv, padlist) Perl_set_padlist((CV*)sv, padlist) 75 #else 76 # define CvPADLIST_set(sv, padlist) (CvPADLIST(sv) = (padlist)) 77 #endif 78 #define CvHSCXT(sv) *(assert_(CvISXSUB((CV*)(sv))) \ 79 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_hscxt)) 80 #ifdef DEBUGGING 81 # if PTRSIZE == 8 82 # define PoisonPADLIST(sv) \ 83 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)UINT64_C(0xEFEFEFEFEFEFEFEF)) 84 # elif PTRSIZE == 4 85 # define PoisonPADLIST(sv) \ 86 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)0xEFEFEFEF) 87 # else 88 # error unknown pointer size 89 # endif 90 #else 91 # define PoisonPADLIST(sv) NOOP 92 #endif 93 94 #define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside 95 #define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq 96 #define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags 97 98 /* These two are sometimes called on non-CVs */ 99 #define CvPROTO(sv) \ 100 ( \ 101 SvPOK(sv) \ 102 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ 103 ? SvEND(sv)+1 : SvPVX_const(sv) \ 104 : NULL \ 105 ) 106 #define CvPROTOLEN(sv) \ 107 ( \ 108 SvPOK(sv) \ 109 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ 110 ? SvLEN(sv)-SvCUR(sv)-2 \ 111 : SvCUR(sv) \ 112 : 0 \ 113 ) 114 115 #define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ 116 #define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ 117 #define CVf_CONST 0x0004 /* inlinable sub */ 118 #define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ 119 120 #define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ 121 #define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ 122 #define CVf_CLONED 0x0040 /* a clone of one of those */ 123 #define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ 124 #define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, 125 * require, eval). */ 126 #define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV 127 (esp. useful for special XSUBs) */ 128 #define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ 129 #ifdef PERL_CORE 130 # define CVf_SLABBED 0x0800 /* Holds refcount on op slab */ 131 #endif 132 #define CVf_DYNFILE 0x1000 /* The filename is malloced */ 133 #define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */ 134 #define CVf_HASEVAL 0x4000 /* contains string eval */ 135 #define CVf_NAMED 0x8000 /* Has a name HEK */ 136 #define CVf_LEXICAL 0x10000 /* Omit package from name */ 137 #define CVf_ANONCONST 0x20000 /* :const - create anonconst op */ 138 139 /* This symbol for optimised communication between toke.c and op.c: */ 140 #define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE|CVf_ANONCONST) 141 142 #define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) 143 #define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) 144 #define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE) 145 146 #define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED) 147 #define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED) 148 #define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED) 149 150 #define CvANON(cv) (CvFLAGS(cv) & CVf_ANON) 151 #define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) 152 #define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) 153 154 /* CvEVAL or CvSPECIAL */ 155 #define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) 156 #define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) 157 #define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) 158 159 #define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG) 160 #define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG) 161 #define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG) 162 163 #define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD) 164 #define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD) 165 #define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD) 166 167 #define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE) 168 #define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE) 169 #define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE) 170 171 /* eval or PL_main_cv */ 172 #define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv)) 173 #define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv)) 174 #define CvEVAL_off(cv) CvUNIQUE_off(cv) 175 176 /* BEGIN|CHECK|INIT|UNITCHECK|END */ 177 #define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv)) 178 #define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv)) 179 #define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv)) 180 181 #define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST) 182 #define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST) 183 #define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST) 184 185 #define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE) 186 #define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE) 187 #define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE) 188 189 #define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB) 190 #define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB) 191 #define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB) 192 193 #define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC) 194 #define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC) 195 #define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC) 196 197 #ifdef PERL_CORE 198 # define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED) 199 # define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED) 200 # define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED) 201 #endif 202 203 #define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE) 204 #define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE) 205 #define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE) 206 207 #define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD) 208 #define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD) 209 #define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD) 210 211 #define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL) 212 #define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL) 213 #define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL) 214 215 #define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED) 216 #define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED) 217 #define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED) 218 219 #define CvLEXICAL(cv) (CvFLAGS(cv) & CVf_LEXICAL) 220 #define CvLEXICAL_on(cv) (CvFLAGS(cv) |= CVf_LEXICAL) 221 #define CvLEXICAL_off(cv) (CvFLAGS(cv) &= ~CVf_LEXICAL) 222 223 #define CvANONCONST(cv) (CvFLAGS(cv) & CVf_ANONCONST) 224 #define CvANONCONST_on(cv) (CvFLAGS(cv) |= CVf_ANONCONST) 225 #define CvANONCONST_off(cv) (CvFLAGS(cv) &= ~CVf_ANONCONST) 226 227 /* Flags for newXS_flags */ 228 #define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */ 229 230 PERL_STATIC_INLINE HEK * 231 CvNAME_HEK(CV *sv) 232 { 233 return CvNAMED(sv) 234 ? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek 235 : 0; 236 } 237 238 /* helper for the common pattern: 239 CvNAMED(sv) ? CvNAME_HEK((CV *)sv) : GvNAME_HEK(CvGV(sv)) 240 */ 241 #define CvGvNAME_HEK(sv) ( \ 242 CvNAMED((CV*)sv) ? \ 243 ((XPVCV*)MUTABLE_PTR(SvANY((SV*)sv)))->xcv_gv_u.xcv_hek\ 244 : GvNAME_HEK(CvGV( (SV*) sv)) \ 245 ) 246 247 /* This lowers the reference count of the previous value, but does *not* 248 increment the reference count of the new value. */ 249 #define CvNAME_HEK_set(cv, hek) ( \ 250 CvNAME_HEK((CV *)(cv)) \ 251 ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \ 252 : (void)0, \ 253 ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \ 254 CvNAMED_on(cv) \ 255 ) 256 257 /* 258 =head1 CV reference counts and CvOUTSIDE 259 260 =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv 261 262 Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing 263 CV (if any). Because pointers to anonymous sub prototypes are 264 stored in C<&> pad slots, it is a possible to get a circular reference, 265 with the parent pointing to the child and vice-versa. To avoid the 266 ensuing memory leak, we do not increment the reference count of the CV 267 pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent 268 has a C<&> pad slot pointing back to us. In this case, we set the 269 C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what 270 circumstances we should decrement the refcount of the parent when freeing 271 the child. 272 273 There is a further complication with non-closure anonymous subs (i.e. those 274 that do not refer to any lexicals outside that sub). In this case, the 275 anonymous prototype is shared rather than being cloned. This has the 276 consequence that the parent may be freed while there are still active 277 children, I<e.g.>, 278 279 BEGIN { $a = sub { eval '$x' } } 280 281 In this case, the BEGIN is freed immediately after execution since there 282 are no active references to it: the anon sub prototype has 283 C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same 284 CV, so it doesn't contribute to BEGIN's refcount either. When $a is 285 executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, 286 and the freed BEGIN is accessed. 287 288 To avoid this, whenever a CV and its associated pad is freed, any 289 C<&> entries in the pad are explicitly removed from the pad, and if the 290 refcount of the pointed-to anon sub is still positive, then that 291 child's C<CvOUTSIDE> is set to point to its grandparent. This will only 292 occur in the single specific case of a non-closure anon prototype 293 having one or more active references (such as C<$a> above). 294 295 One other thing to consider is that a CV may be merely undefined 296 rather than freed, eg C<undef &foo>. In this case, its refcount may 297 not have reached zero, but we still delete its pad and its C<CvROOT> etc. 298 Since various children may still have their C<CvOUTSIDE> pointing at this 299 undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that 300 the chain of lexical scopes is unbroken. For example, the following 301 should print 123: 302 303 my $x = 123; 304 sub tmp { sub { eval '$x' } } 305 my $a = tmp(); 306 undef &tmp; 307 print $a->(); 308 309 =cut 310 */ 311 312 typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); 313 314 #define CALL_CHECKER_REQUIRE_GV MGf_REQUIRE_GV 315 316 #define CV_NAME_NOTQUAL 1 317 318 #ifdef PERL_CORE 319 # define CV_UNDEF_KEEP_NAME 1 320 #endif 321 322 /* 323 * ex: set ts=8 sts=4 sw=4 et: 324 */ 325