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 =for apidoc Ayh||CV 20 21 =for apidoc ADmnU||Nullcv 22 Null CV pointer. 23 24 (deprecated - use C<(CV *)NULL> instead) 25 26 =for apidoc Am|HV*|CvSTASH|CV* cv 27 Returns the stash of the CV. A stash is the symbol table hash, containing 28 the package-scoped variables in the package where the subroutine was defined. 29 For more information, see L<perlguts>. 30 31 This also has a special use with XS AUTOLOAD subs. 32 See L<perlguts/Autoloading with XSUBs>. 33 34 =cut 35 */ 36 37 #ifndef PERL_CORE 38 # define Nullcv Null(CV*) 39 #endif 40 41 #define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash) 42 #define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st) 43 #define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start 44 #define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root 45 #define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub 46 #define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany 47 #define CvGV(sv) Perl_CvGV(aTHX_ (CV *)(sv)) 48 #define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv) 49 #define CvHASGV(cv) cBOOL(SvANY(cv)->xcv_gv_u.xcv_gv) 50 #define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file 51 #ifdef USE_ITHREADS 52 # define CvFILE_set_from_cop(sv, cop) \ 53 (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv)) 54 #else 55 # define CvFILE_set_from_cop(sv, cop) \ 56 (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv)) 57 #endif 58 #define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv))) 59 #define CvDEPTH(sv) (*Perl_CvDEPTH((const CV *)sv)) 60 /* For use when you only have a XPVCV*, not a real CV*. 61 Must be assert protected as in Perl_CvDEPTH before use. */ 62 #define CvDEPTHunsafe(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_depth 63 64 /* these CvPADLIST/CvRESERVED asserts can be reverted one day, once stabilized */ 65 #define CvPADLIST(sv) (*(assert_(!CvISXSUB((CV*)(sv))) \ 66 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist))) 67 /* CvPADLIST_set is not public API, it can be removed one day, once stabilized */ 68 #ifdef DEBUGGING 69 # define CvPADLIST_set(sv, padlist) Perl_set_padlist((CV*)sv, padlist) 70 #else 71 # define CvPADLIST_set(sv, padlist) (CvPADLIST(sv) = (padlist)) 72 #endif 73 #define CvHSCXT(sv) *(assert_(CvISXSUB((CV*)(sv))) \ 74 &(((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_hscxt)) 75 #ifdef DEBUGGING 76 # if PTRSIZE == 8 77 # define PoisonPADLIST(sv) \ 78 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)UINT64_C(0xEFEFEFEFEFEFEFEF)) 79 # elif PTRSIZE == 4 80 # define PoisonPADLIST(sv) \ 81 (((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist_u.xcv_padlist = (PADLIST *)0xEFEFEFEF) 82 # else 83 # error unknown pointer size 84 # endif 85 #else 86 # define PoisonPADLIST(sv) NOOP 87 #endif 88 89 #define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside 90 #define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq 91 #define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags 92 93 /* These two are sometimes called on non-CVs */ 94 #define CvPROTO(sv) \ 95 ( \ 96 SvPOK(sv) \ 97 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ 98 ? SvEND(sv)+1 : SvPVX_const(sv) \ 99 : NULL \ 100 ) 101 #define CvPROTOLEN(sv) \ 102 ( \ 103 SvPOK(sv) \ 104 ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \ 105 ? SvLEN(sv)-SvCUR(sv)-2 \ 106 : SvCUR(sv) \ 107 : 0 \ 108 ) 109 110 #define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */ 111 #define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */ 112 #define CVf_CONST 0x0004 /* inlinable sub */ 113 #define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */ 114 115 #define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */ 116 #define CVf_CLONE 0x0020 /* anon CV uses external lexicals */ 117 #define CVf_CLONED 0x0040 /* a clone of one of those */ 118 #define CVf_ANON 0x0080 /* CV is not pointed to by a GV */ 119 #define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv, 120 * require, eval). */ 121 #define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV 122 (esp. useful for special XSUBs) */ 123 #define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */ 124 #if defined(PERL_CORE) || defined(PERL_EXT) 125 # define CVf_SLABBED 0x0800 /* Holds refcount on op slab */ 126 #endif 127 #define CVf_DYNFILE 0x1000 /* The filename is malloced */ 128 #define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */ 129 #define CVf_HASEVAL 0x4000 /* contains string eval */ 130 #define CVf_NAMED 0x8000 /* Has a name HEK */ 131 #define CVf_LEXICAL 0x10000 /* Omit package from name */ 132 #define CVf_ANONCONST 0x20000 /* :const - create anonconst op */ 133 #define CVf_SIGNATURE 0x40000 /* CV uses a signature */ 134 135 /* This symbol for optimised communication between toke.c and op.c: */ 136 #define CVf_BUILTIN_ATTRS (CVf_METHOD|CVf_LVALUE|CVf_ANONCONST) 137 138 #define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE) 139 #define CvCLONE_on(cv) (CvFLAGS(cv) |= CVf_CLONE) 140 #define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE) 141 142 #define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED) 143 #define CvCLONED_on(cv) (CvFLAGS(cv) |= CVf_CLONED) 144 #define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED) 145 146 #define CvANON(cv) (CvFLAGS(cv) & CVf_ANON) 147 #define CvANON_on(cv) (CvFLAGS(cv) |= CVf_ANON) 148 #define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON) 149 150 /* CvEVAL or CvSPECIAL */ 151 #define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE) 152 #define CvUNIQUE_on(cv) (CvFLAGS(cv) |= CVf_UNIQUE) 153 #define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE) 154 155 #define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG) 156 #define CvNODEBUG_on(cv) (CvFLAGS(cv) |= CVf_NODEBUG) 157 #define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG) 158 159 #define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD) 160 #define CvMETHOD_on(cv) (CvFLAGS(cv) |= CVf_METHOD) 161 #define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD) 162 163 #define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE) 164 #define CvLVALUE_on(cv) (CvFLAGS(cv) |= CVf_LVALUE) 165 #define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE) 166 167 /* eval or PL_main_cv */ 168 #define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv)) 169 #define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv)) 170 #define CvEVAL_off(cv) CvUNIQUE_off(cv) 171 172 /* BEGIN|CHECK|INIT|UNITCHECK|END */ 173 #define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv)) 174 #define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv)) 175 #define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv)) 176 177 #define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST) 178 #define CvCONST_on(cv) (CvFLAGS(cv) |= CVf_CONST) 179 #define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST) 180 181 #define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE) 182 #define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) |= CVf_WEAKOUTSIDE) 183 #define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE) 184 185 #define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB) 186 #define CvISXSUB_on(cv) (CvFLAGS(cv) |= CVf_ISXSUB) 187 #define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB) 188 189 #define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC) 190 #define CvCVGV_RC_on(cv) (CvFLAGS(cv) |= CVf_CVGV_RC) 191 #define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC) 192 193 #ifdef PERL_CORE 194 # define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED) 195 # define CvSLABBED_on(cv) (CvFLAGS(cv) |= CVf_SLABBED) 196 # define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED) 197 #endif 198 199 #define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE) 200 #define CvDYNFILE_on(cv) (CvFLAGS(cv) |= CVf_DYNFILE) 201 #define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE) 202 203 #define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD) 204 #define CvAUTOLOAD_on(cv) (CvFLAGS(cv) |= CVf_AUTOLOAD) 205 #define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD) 206 207 #define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL) 208 #define CvHASEVAL_on(cv) (CvFLAGS(cv) |= CVf_HASEVAL) 209 #define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL) 210 211 #define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED) 212 #define CvNAMED_on(cv) (CvFLAGS(cv) |= CVf_NAMED) 213 #define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED) 214 215 #define CvLEXICAL(cv) (CvFLAGS(cv) & CVf_LEXICAL) 216 #define CvLEXICAL_on(cv) (CvFLAGS(cv) |= CVf_LEXICAL) 217 #define CvLEXICAL_off(cv) (CvFLAGS(cv) &= ~CVf_LEXICAL) 218 219 #define CvANONCONST(cv) (CvFLAGS(cv) & CVf_ANONCONST) 220 #define CvANONCONST_on(cv) (CvFLAGS(cv) |= CVf_ANONCONST) 221 #define CvANONCONST_off(cv) (CvFLAGS(cv) &= ~CVf_ANONCONST) 222 223 #define CvSIGNATURE(cv) (CvFLAGS(cv) & CVf_SIGNATURE) 224 #define CvSIGNATURE_on(cv) (CvFLAGS(cv) |= CVf_SIGNATURE) 225 #define CvSIGNATURE_off(cv) (CvFLAGS(cv) &= ~CVf_SIGNATURE) 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 /* 258 259 =for apidoc m|bool|CvWEAKOUTSIDE|CV *cv 260 261 Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing 262 CV (if any). Because pointers to anonymous sub prototypes are 263 stored in C<&> pad slots, it is a possible to get a circular reference, 264 with the parent pointing to the child and vice-versa. To avoid the 265 ensuing memory leak, we do not increment the reference count of the CV 266 pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent 267 has a C<&> pad slot pointing back to us. In this case, we set the 268 C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what 269 circumstances we should decrement the refcount of the parent when freeing 270 the child. 271 272 There is a further complication with non-closure anonymous subs (i.e. those 273 that do not refer to any lexicals outside that sub). In this case, the 274 anonymous prototype is shared rather than being cloned. This has the 275 consequence that the parent may be freed while there are still active 276 children, I<e.g.>, 277 278 BEGIN { $a = sub { eval '$x' } } 279 280 In this case, the BEGIN is freed immediately after execution since there 281 are no active references to it: the anon sub prototype has 282 C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same 283 CV, so it doesn't contribute to BEGIN's refcount either. When $a is 284 executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed, 285 and the freed BEGIN is accessed. 286 287 To avoid this, whenever a CV and its associated pad is freed, any 288 C<&> entries in the pad are explicitly removed from the pad, and if the 289 refcount of the pointed-to anon sub is still positive, then that 290 child's C<CvOUTSIDE> is set to point to its grandparent. This will only 291 occur in the single specific case of a non-closure anon prototype 292 having one or more active references (such as C<$a> above). 293 294 One other thing to consider is that a CV may be merely undefined 295 rather than freed, eg C<undef &foo>. In this case, its refcount may 296 not have reached zero, but we still delete its pad and its C<CvROOT> etc. 297 Since various children may still have their C<CvOUTSIDE> pointing at this 298 undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that 299 the chain of lexical scopes is unbroken. For example, the following 300 should print 123: 301 302 my $x = 123; 303 sub tmp { sub { eval '$x' } } 304 my $a = tmp(); 305 undef &tmp; 306 print $a->(); 307 308 =cut 309 */ 310 311 typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *); 312 313 #define CALL_CHECKER_REQUIRE_GV MGf_REQUIRE_GV 314 315 #define CV_NAME_NOTQUAL 1 316 317 #ifdef PERL_CORE 318 # define CV_UNDEF_KEEP_NAME 1 319 #endif 320 321 /* 322 * ex: set ts=8 sts=4 sw=4 et: 323 */ 324