3 * Copyright (C) 2002, 2003, 2005, 2006, 2007, 2008,
4 * 2009, 2010, 2011 by Larry Wall and others
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.
9 * This file defines the types and macros associated with the API for
10 * manipulating scratchpads, which are used by perl to store lexical
11 * variables, op targets and constants.
15 =head1 Pad Data Structures
19 /* offsets within a pad */
22 typedef U32TYPE PADOFFSET;
25 typedef U64TYPE PADOFFSET;
28 #define NOT_IN_PAD ((PADOFFSET) -1)
32 SSize_t xpadl_max; /* max index for which array has space */
33 PAD ** xpadl_alloc; /* pointer to beginning of array of AVs */
34 PADNAMELIST*xpadl_outid; /* Padnamelist of outer pad; used as ID */
38 /* a value that PL_cop_seqmax is guaranteed never to be,
39 * flagging that a lexical is being introduced, or has not yet left scope
41 #define PERL_PADSEQ_INTRO U32_MAX
42 #define COP_SEQMAX_INC \
44 (void)(PL_cop_seqmax == PERL_PADSEQ_INTRO && PL_cop_seqmax++))
47 /* B.xs needs these for the benefit of B::Deparse */
48 /* Low range end is exclusive (valid from the cop seq after this one) */
49 /* High range end is inclusive (valid up to this cop seq) */
51 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
52 # define COP_SEQ_RANGE_LOW(sv) \
53 (({ const SV *const _sv_cop_seq_range_low = (const SV *) (sv); \
54 assert(SvTYPE(_sv_cop_seq_range_low) == SVt_NV \
55 || SvTYPE(_sv_cop_seq_range_low) >= SVt_PVNV); \
56 assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVAV); \
57 assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVHV); \
58 assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVCV); \
59 assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVFM); \
60 assert(!isGV_with_GP(_sv_cop_seq_range_low)); \
61 ((XPVNV*) MUTABLE_PTR(SvANY(_sv_cop_seq_range_low)))->xnv_u.xpad_cop_seq.xlow; \
63 # define COP_SEQ_RANGE_HIGH(sv) \
64 (({ const SV *const _sv_cop_seq_range_high = (const SV *) (sv); \
65 assert(SvTYPE(_sv_cop_seq_range_high) == SVt_NV \
66 || SvTYPE(_sv_cop_seq_range_high) >= SVt_PVNV); \
67 assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVAV); \
68 assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVHV); \
69 assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVCV); \
70 assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVFM); \
71 assert(!isGV_with_GP(_sv_cop_seq_range_high)); \
72 ((XPVNV*) MUTABLE_PTR(SvANY(_sv_cop_seq_range_high)))->xnv_u.xpad_cop_seq.xhigh; \
74 # define PARENT_PAD_INDEX(sv) \
75 (({ const SV *const _sv_parent_pad_index = (const SV *) (sv); \
76 assert(SvTYPE(_sv_parent_pad_index) == SVt_NV \
77 || SvTYPE(_sv_parent_pad_index) >= SVt_PVNV); \
78 assert(SvTYPE(_sv_parent_pad_index) != SVt_PVAV); \
79 assert(SvTYPE(_sv_parent_pad_index) != SVt_PVHV); \
80 assert(SvTYPE(_sv_parent_pad_index) != SVt_PVCV); \
81 assert(SvTYPE(_sv_parent_pad_index) != SVt_PVFM); \
82 assert(!isGV_with_GP(_sv_parent_pad_index)); \
83 ((XPVNV*) MUTABLE_PTR(SvANY(_sv_parent_pad_index)))->xnv_u.xpad_cop_seq.xlow; \
85 # define PARENT_FAKELEX_FLAGS(sv) \
86 (({ const SV *const _sv_parent_fakelex_flags = (const SV *) (sv); \
87 assert(SvTYPE(_sv_parent_fakelex_flags) == SVt_NV \
88 || SvTYPE(_sv_parent_fakelex_flags) >= SVt_PVNV); \
89 assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVAV); \
90 assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVHV); \
91 assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVCV); \
92 assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVFM); \
93 assert(!isGV_with_GP(_sv_parent_fakelex_flags)); \
94 ((XPVNV*) MUTABLE_PTR(SvANY(_sv_parent_fakelex_flags)))->xnv_u.xpad_cop_seq.xhigh; \
97 # define COP_SEQ_RANGE_LOW(sv) \
98 (0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xlow))
99 # define COP_SEQ_RANGE_HIGH(sv) \
100 (0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xhigh))
103 # define PARENT_PAD_INDEX(sv) \
104 (0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xlow))
105 # define PARENT_FAKELEX_FLAGS(sv) \
106 (0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xhigh))
109 /* Flags set in the SvIVX field of FAKE namesvs */
111 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
112 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
114 /* flags for the pad_new() function */
116 #define padnew_CLONE 1 /* this pad is for a cloned CV */
117 #define padnew_SAVE 2 /* save old globals */
118 #define padnew_SAVESUB 4 /* also save extra stuff for start of sub */
120 /* values for the pad_tidy() function */
123 padtidy_SUB, /* tidy up a pad for a sub, */
124 padtidy_SUBCLONE, /* a cloned sub, */
125 padtidy_FORMAT /* or a format */
128 /* flags for pad_add_name_pvn. */
130 #define padadd_OUR 0x01 /* our declaration. */
131 #define padadd_STATE 0x02 /* state declaration. */
132 #define padadd_NO_DUP_CHECK 0x04 /* skip warning on dups. */
133 #define padadd_STALEOK 0x08 /* allow stale lexical in active
134 * sub, but only one level up */
135 #define padadd_UTF8_NAME SVf_UTF8 /* name is UTF-8 encoded. */
137 /* ASSERT_CURPAD_LEGAL and ASSERT_CURPAD_ACTIVE respectively determine
138 * whether PL_comppad and PL_curpad are consistent and whether they have
141 # define pad_peg(label)
144 # define ASSERT_CURPAD_LEGAL(label) \
146 if (PL_comppad ? (AvARRAY(PL_comppad) != PL_curpad) : (PL_curpad != 0)) \
147 Perl_croak(aTHX_ "panic: illegal pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
148 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
151 # define ASSERT_CURPAD_ACTIVE(label) \
153 if (!PL_comppad || (AvARRAY(PL_comppad) != PL_curpad)) \
154 Perl_croak(aTHX_ "panic: invalid pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
155 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
157 # define ASSERT_CURPAD_LEGAL(label)
158 # define ASSERT_CURPAD_ACTIVE(label)
163 /* Note: the following three macros are actually defined in scope.h, but
164 * they are documented here for completeness, since they directly or
165 * indirectly affect pads.
167 =for apidoc m|void|SAVEPADSV |PADOFFSET po
168 Save a pad slot (used to restore after an iteration)
170 XXX DAPM it would make more sense to make the arg a PADOFFSET
171 =for apidoc m|void|SAVECLEARSV |SV **svp
172 Clear the pointed to pad value on scope exit. (i.e. the runtime action of
175 =for apidoc m|void|SAVECOMPPAD
176 save PL_comppad and PL_curpad
179 =for apidoc Amx|PAD **|PadlistARRAY|PADLIST padlist
180 The C array of a padlist, containing the pads. Only subscript it with
181 numbers >= 1, as the 0th entry is not guaranteed to remain usable.
183 =for apidoc Amx|SSize_t|PadlistMAX|PADLIST padlist
184 The index of the last allocated space in the padlist. Note that the last
185 pad may be in an earlier slot. Any entries following it will be NULL in
188 =for apidoc Amx|PADNAMELIST *|PadlistNAMES|PADLIST padlist
189 The names associated with pad entries.
191 =for apidoc Amx|PADNAME **|PadlistNAMESARRAY|PADLIST padlist
192 The C array of pad names.
194 =for apidoc Amx|SSize_t|PadlistNAMESMAX|PADLIST padlist
195 The index of the last pad name.
197 =for apidoc Amx|U32|PadlistREFCNT|PADLIST padlist
198 The reference count of the padlist. Currently this is always 1.
200 =for apidoc Amx|PADNAME **|PadnamelistARRAY|PADNAMELIST pnl
201 The C array of pad names.
203 =for apidoc Amx|SSize_t|PadnamelistMAX|PADNAMELIST pnl
204 The index of the last pad name.
206 =for apidoc Amx|SV **|PadARRAY|PAD pad
207 The C array of pad entries.
209 =for apidoc Amx|SSize_t|PadMAX|PAD pad
210 The index of the last pad entry.
212 =for apidoc Amx|char *|PadnamePV|PADNAME pn
213 The name stored in the pad name struct. This returns NULL for a target or
216 =for apidoc Amx|STRLEN|PadnameLEN|PADNAME pn
217 The length of the name.
219 =for apidoc Amx|bool|PadnameUTF8|PADNAME pn
220 Whether PadnamePV is in UTF8.
222 =for apidoc Amx|SV *|PadnameSV|PADNAME pn
223 Returns the pad name as an SV. This is currently just C<pn>. It will
224 begin returning a new mortal SV if pad names ever stop being SVs.
226 =for apidoc m|bool|PadnameIsOUR|PADNAME pn
227 Whether this is an "our" variable.
229 =for apidoc m|HV *|PadnameOURSTASH
230 The stash in which this "our" variable was declared.
232 =for apidoc m|bool|PadnameOUTER|PADNAME pn
233 Whether this entry belongs to an outer pad.
235 =for apidoc m|bool|PadnameIsSTATE|PADNAME pn
236 Whether this is a "state" variable.
238 =for apidoc m|HV *|PadnameTYPE|PADNAME pn
239 The stash associated with a typed lexical. This returns the %Foo:: hash
243 =for apidoc m|SV *|PAD_SETSV |PADOFFSET po|SV* sv
244 Set the slot at offset C<po> in the current pad to C<sv>
246 =for apidoc m|SV *|PAD_SV |PADOFFSET po
247 Get the value at offset C<po> in the current pad
249 =for apidoc m|SV *|PAD_SVl |PADOFFSET po
250 Lightweight and lvalue version of C<PAD_SV>.
251 Get or set the value at offset C<po> in the current pad.
252 Unlike C<PAD_SV>, does not print diagnostics with -DX.
253 For internal use only.
255 =for apidoc m|SV *|PAD_BASE_SV |PADLIST padlist|PADOFFSET po
256 Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
258 =for apidoc m|void|PAD_SET_CUR |PADLIST padlist|I32 n
259 Set the current pad to be pad C<n> in the padlist, saving
260 the previous current pad. NB currently this macro expands to a string too
261 long for some compilers, so it's best to replace it with
264 PAD_SET_CUR_NOSAVE(padlist,n);
267 =for apidoc m|void|PAD_SET_CUR_NOSAVE |PADLIST padlist|I32 n
268 like PAD_SET_CUR, but without the save
270 =for apidoc m|void|PAD_SAVE_SETNULLPAD
271 Save the current pad then set it to null.
273 =for apidoc m|void|PAD_SAVE_LOCAL|PAD *opad|PAD *npad
274 Save the current pad to the local variable opad, then make the
275 current pad equal to npad
277 =for apidoc m|void|PAD_RESTORE_LOCAL|PAD *opad
278 Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()
283 #define PadlistARRAY(pl) (pl)->xpadl_alloc
284 #define PadlistMAX(pl) (pl)->xpadl_max
285 #define PadlistNAMES(pl) (*PadlistARRAY(pl))
286 #define PadlistNAMESARRAY(pl) PadnamelistARRAY(PadlistNAMES(pl))
287 #define PadlistNAMESMAX(pl) PadnamelistMAX(PadlistNAMES(pl))
288 #define PadlistREFCNT(pl) 1 /* reserved for future use */
290 #define PadnamelistARRAY(pnl) AvARRAY(pnl)
291 #define PadnamelistMAX(pnl) AvFILLp(pnl)
292 #define PadnamelistMAXNAMED(pnl) \
293 ((XPVAV*) SvANY(pnl))->xmg_u.xmg_hash_index
295 #define PadARRAY(pad) AvARRAY(pad)
296 #define PadMAX(pad) AvFILLp(pad)
298 #define PadnamePV(pn) (SvPOKp(pn) ? SvPVX(pn) : NULL)
299 #define PadnameLEN(pn) ((pn) == &PL_sv_undef ? 0 : SvCUR(pn))
300 #define PadnameUTF8(pn) !!SvUTF8(pn)
301 #define PadnameSV(pn) pn
302 #define PadnameIsOUR(pn) !!SvPAD_OUR(pn)
303 #define PadnameOURSTASH(pn) SvOURSTASH(pn)
304 #define PadnameOUTER(pn) !!SvFAKE(pn)
305 #define PadnameIsSTATE(pn) !!SvPAD_STATE(pn)
306 #define PadnameTYPE(pn) (SvPAD_TYPED(pn) ? SvSTASH(pn) : NULL)
307 #define PadnameLVALUE(pn) \
308 ((SvFLAGS(pn) & (SVpad_NAME|SVpad_LVALUE))==(SVpad_NAME|SVpad_LVALUE))
310 #define PadnameLVALUE_on(pn) (SvFLAGS(pn) |= SVpad_NAME|SVpad_LVALUE)
313 # define PAD_SV(po) pad_sv(po)
314 # define PAD_SETSV(po,sv) pad_setsv(po,sv)
316 # define PAD_SV(po) (PL_curpad[po])
317 # define PAD_SETSV(po,sv) PL_curpad[po] = (sv)
320 #define PAD_SVl(po) (PL_curpad[po])
322 #define PAD_BASE_SV(padlist, po) \
323 (PadlistARRAY(padlist)[1]) \
324 ? AvARRAY(MUTABLE_AV((PadlistARRAY(padlist)[1])))[po] \
328 #define PAD_SET_CUR_NOSAVE(padlist,nth) \
329 PL_comppad = (PAD*) (PadlistARRAY(padlist)[nth]); \
330 PL_curpad = AvARRAY(PL_comppad); \
331 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
332 "Pad 0x%" UVxf "[0x%" UVxf "] set_cur depth=%d\n", \
333 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (int)(nth)));
336 #define PAD_SET_CUR(padlist,nth) \
338 PAD_SET_CUR_NOSAVE(padlist,nth);
341 #define PAD_SAVE_SETNULLPAD() SAVECOMPPAD(); \
342 PL_comppad = NULL; PL_curpad = NULL; \
343 DEBUG_Xv(PerlIO_printf(Perl_debug_log, "Pad set_null\n"));
345 #define PAD_SAVE_LOCAL(opad,npad) \
347 PL_comppad = (npad); \
348 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
349 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
350 "Pad 0x%" UVxf "[0x%" UVxf "] save_local\n", \
351 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
353 #define PAD_RESTORE_LOCAL(opad) \
354 assert(!opad || !SvIS_FREED(opad)); \
356 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
357 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
358 "Pad 0x%" UVxf "[0x%" UVxf "] restore_local\n", \
359 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
363 =for apidoc m|void|CX_CURPAD_SAVE|struct context
364 Save the current pad in the given context block structure.
366 =for apidoc m|SV *|CX_CURPAD_SV|struct context|PADOFFSET po
367 Access the SV at offset po in the saved current pad in the given
368 context block structure (can be used as an lvalue).
373 #define CX_CURPAD_SAVE(block) (block).oldcomppad = PL_comppad
374 #define CX_CURPAD_SV(block,po) (AvARRAY(MUTABLE_AV(((block).oldcomppad)))[po])
378 =for apidoc m|U32|PAD_COMPNAME_FLAGS|PADOFFSET po
379 Return the flags for the current compiling pad name
380 at offset C<po>. Assumes a valid slot entry.
382 =for apidoc m|char *|PAD_COMPNAME_PV|PADOFFSET po
383 Return the name of the current compiling pad name
384 at offset C<po>. Assumes a valid slot entry.
386 =for apidoc m|HV *|PAD_COMPNAME_TYPE|PADOFFSET po
387 Return the type (stash) of the current compiling pad name at offset
388 C<po>. Must be a valid name. Returns null if not typed.
390 =for apidoc m|HV *|PAD_COMPNAME_OURSTASH|PADOFFSET po
391 Return the stash associated with an C<our> variable.
392 Assumes the slot entry is a valid C<our> lexical.
394 =for apidoc m|STRLEN|PAD_COMPNAME_GEN|PADOFFSET po
395 The generation number of the name at offset C<po> in the current
396 compiling pad (lvalue). Note that C<SvUVX> is hijacked for this purpose.
398 =for apidoc m|STRLEN|PAD_COMPNAME_GEN_set|PADOFFSET po|int gen
399 Sets the generation number of the name at offset C<po> in the current
400 ling pad (lvalue) to C<gen>. Note that C<SvUV_set> is hijacked for this purpose.
406 #define PAD_COMPNAME(po) PAD_COMPNAME_SV(po)
407 #define PAD_COMPNAME_SV(po) (AvARRAY(PL_comppad_name)[(po)])
408 #define PAD_COMPNAME_FLAGS(po) SvFLAGS(PAD_COMPNAME_SV(po))
409 #define PAD_COMPNAME_FLAGS_isOUR(po) SvPAD_OUR(PAD_COMPNAME_SV(po))
410 #define PAD_COMPNAME_PV(po) SvPV_nolen(PAD_COMPNAME_SV(po))
412 #define PAD_COMPNAME_TYPE(po) pad_compname_type(po)
414 #define PAD_COMPNAME_OURSTASH(po) \
415 (SvOURSTASH(PAD_COMPNAME_SV(po)))
417 #define PAD_COMPNAME_GEN(po) ((STRLEN)SvUVX(AvARRAY(PL_comppad_name)[po]))
419 #define PAD_COMPNAME_GEN_set(po, gen) SvUV_set(AvARRAY(PL_comppad_name)[po], (UV)(gen))
423 =for apidoc m|void|PAD_CLONE_VARS|PerlInterpreter *proto_perl|CLONE_PARAMS* param
424 Clone the state variables associated with running and compiling pads.
429 /* NB - we set PL_comppad to null unless it points at a value that
430 * has already been dup'ed, ie it points to part of an active padlist.
431 * Otherwise PL_comppad ends up being a leaked scalar in code like
433 * threads->create(sub { threads->create(sub {...} ) } );
434 * where the second thread dups the outer sub's comppad but not the
435 * sub's CV or padlist. */
437 #define PAD_CLONE_VARS(proto_perl, param) \
438 PL_comppad = av_dup(proto_perl->Icomppad, param); \
439 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
440 PL_comppad_name = av_dup(proto_perl->Icomppad_name, param); \
441 PL_comppad_name_fill = proto_perl->Icomppad_name_fill; \
442 PL_comppad_name_floor = proto_perl->Icomppad_name_floor; \
443 PL_min_intro_pending = proto_perl->Imin_intro_pending; \
444 PL_max_intro_pending = proto_perl->Imax_intro_pending; \
445 PL_padix = proto_perl->Ipadix; \
446 PL_padix_floor = proto_perl->Ipadix_floor; \
447 PL_pad_reset_pending = proto_perl->Ipad_reset_pending; \
448 PL_cop_seqmax = proto_perl->Icop_seqmax;
451 =for apidoc Am|PADOFFSET|pad_add_name_pvs|const char *name|U32 flags|HV *typestash|HV *ourstash
453 Exactly like L</pad_add_name_pvn>, but takes a literal string instead
454 of a string/length pair.
459 #define pad_add_name_pvs(name,flags,typestash,ourstash) \
460 Perl_pad_add_name_pvn(aTHX_ STR_WITH_LEN(name), flags, typestash, ourstash)
463 =for apidoc Am|PADOFFSET|pad_findmy_pvs|const char *name|U32 flags
465 Exactly like L</pad_findmy_pvn>, but takes a literal string instead
466 of a string/length pair.
471 #define pad_findmy_pvs(name,flags) \
472 Perl_pad_findmy_pvn(aTHX_ STR_WITH_LEN(name), flags)
476 * c-indentation-style: bsd
478 * indent-tabs-mode: nil
481 * ex: set ts=8 sts=4 sw=4 et: