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 */
21 typedef SSize_t PADOFFSET; /* signed so that -1 is a valid value */
22 #define NOT_IN_PAD ((PADOFFSET) -1)
24 /* B.xs expects the first members of these two structs to line up
25 (xpadl_max with xpadnl_fill).
29 SSize_t xpadl_max; /* max index for which array has space */
31 PAD ** xpadlarr_alloc; /* Pointer to beginning of array of AVs.
32 index 0 is a padnamelist * */
35 PAD * pad_1; /* this slice of PAD * array always alloced */
36 PAD * pad_2; /* maybe unalloced */
37 } * xpadlarr_dbg; /* for use with a C debugger only */
39 U32 xpadl_id; /* Semi-unique ID, shared between clones */
40 U32 xpadl_outid; /* ID of outer pad */
44 SSize_t xpadnl_fill; /* max index in use */
45 PADNAME ** xpadnl_alloc; /* pointer to beginning of array */
46 SSize_t xpadnl_max; /* max index for which array has space */
47 PADOFFSET xpadnl_max_named; /* highest index with len > 0 */
51 /* PERL_PADNAME_MINIMAL uses less memory, but on some platforms
52 PERL_PADNAME_ALIGNED may be faster, so platform-specific hints can
53 define one or the other. */
54 #if defined(PERL_PADNAME_MINIMAL) && defined (PERL_PADNAME_ALIGNED)
55 # error PERL_PADNAME_MINIMAL and PERL_PADNAME_ALIGNED are exclusive
58 #if !defined(PERL_PADNAME_MINIMAL) && !defined(PERL_PADNAME_ALIGNED)
59 # define PERL_PADNAME_MINIMAL
62 #define _PADNAME_BASE \
64 HV * xpadn_ourstash; \
66 HV * xpadn_typestash; \
80 struct padname_with_str {
81 #ifdef PERL_PADNAME_MINIMAL
84 struct padname xpadn_padname;
91 #define PADNAME_FROM_PV(s) \
92 ((PADNAME *)((s) - STRUCT_OFFSET(struct padname_with_str, xpadn_str)))
95 /* a value that PL_cop_seqmax is guaranteed never to be,
96 * flagging that a lexical is being introduced, or has not yet left scope
98 #define PERL_PADSEQ_INTRO U32_MAX
99 #define COP_SEQMAX_INC \
101 (void)(PL_cop_seqmax == PERL_PADSEQ_INTRO && PL_cop_seqmax++))
104 /* B.xs needs these for the benefit of B::Deparse */
105 /* Low range end is exclusive (valid from the cop seq after this one) */
106 /* High range end is inclusive (valid up to this cop seq) */
108 #define COP_SEQ_RANGE_LOW(pn) (pn)->xpadn_low
109 #define COP_SEQ_RANGE_HIGH(pn) (pn)->xpadn_high
110 #define PARENT_PAD_INDEX(pn) (pn)->xpadn_low
111 #define PARENT_FAKELEX_FLAGS(pn) (pn)->xpadn_high
113 /* Flags set in the SvIVX field of FAKE namesvs */
115 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
116 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
118 /* flags for the pad_new() function */
120 #define padnew_CLONE 1 /* this pad is for a cloned CV */
121 #define padnew_SAVE 2 /* save old globals */
122 #define padnew_SAVESUB 4 /* also save extra stuff for start of sub */
124 /* values for the pad_tidy() function */
127 padtidy_SUB, /* tidy up a pad for a sub, */
128 padtidy_SUBCLONE, /* a cloned sub, */
129 padtidy_FORMAT /* or a format */
132 /* flags for pad_add_name_pvn. */
134 #define padadd_OUR 0x01 /* our declaration. */
135 #define padadd_STATE 0x02 /* state declaration. */
136 #define padadd_NO_DUP_CHECK 0x04 /* skip warning on dups. */
137 #define padadd_STALEOK 0x08 /* allow stale lexical in active
138 * sub, but only one level up */
140 /* ASSERT_CURPAD_LEGAL and ASSERT_CURPAD_ACTIVE respectively determine
141 * whether PL_comppad and PL_curpad are consistent and whether they have
144 # define pad_peg(label)
147 # define ASSERT_CURPAD_LEGAL(label) \
149 if (PL_comppad ? (AvARRAY(PL_comppad) != PL_curpad) : (PL_curpad != 0)) \
150 Perl_croak(aTHX_ "panic: illegal pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
151 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
154 # define ASSERT_CURPAD_ACTIVE(label) \
156 if (!PL_comppad || (AvARRAY(PL_comppad) != PL_curpad)) \
157 Perl_croak(aTHX_ "panic: invalid pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
158 label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
160 # define ASSERT_CURPAD_LEGAL(label)
161 # define ASSERT_CURPAD_ACTIVE(label)
166 /* Note: the following three macros are actually defined in scope.h, but
167 * they are documented here for completeness, since they directly or
168 * indirectly affect pads.
170 =for apidoc m|void|SAVEPADSV |PADOFFSET po
171 Save a pad slot (used to restore after an iteration)
173 XXX DAPM it would make more sense to make the arg a PADOFFSET
174 =for apidoc m|void|SAVECLEARSV |SV **svp
175 Clear the pointed to pad value on scope exit. (i.e. the runtime action of
178 =for apidoc m|void|SAVECOMPPAD
179 save C<PL_comppad> and C<PL_curpad>
182 =for apidoc Amx|PAD **|PadlistARRAY|PADLIST * padlist
183 The C array of a padlist, containing the pads. Only subscript it with
184 numbers >= 1, as the 0th entry is not guaranteed to remain usable.
186 =for apidoc Amx|SSize_t|PadlistMAX|PADLIST * padlist
187 The index of the last allocated space in the padlist. Note that the last
188 pad may be in an earlier slot. Any entries following it will be C<NULL> in
191 =for apidoc Amx|PADNAMELIST *|PadlistNAMES|PADLIST * padlist
192 The names associated with pad entries.
194 =for apidoc Amx|PADNAME **|PadlistNAMESARRAY|PADLIST * padlist
195 The C array of pad names.
197 =for apidoc Amx|SSize_t|PadlistNAMESMAX|PADLIST * padlist
198 The index of the last pad name.
200 =for apidoc Amx|U32|PadlistREFCNT|PADLIST * padlist
201 The reference count of the padlist. Currently this is always 1.
203 =for apidoc Amx|PADNAME **|PadnamelistARRAY|PADNAMELIST * pnl
204 The C array of pad names.
206 =for apidoc Amx|SSize_t|PadnamelistMAX|PADNAMELIST * pnl
207 The index of the last pad name.
209 =for apidoc Amx|SSize_t|PadnamelistREFCNT|PADNAMELIST * pnl
210 The reference count of the pad name list.
212 =for apidoc Amx|void|PadnamelistREFCNT_dec|PADNAMELIST * pnl
213 Lowers the reference count of the pad name list.
215 =for apidoc Amx|SV **|PadARRAY|PAD * pad
216 The C array of pad entries.
218 =for apidoc Amx|SSize_t|PadMAX|PAD * pad
219 The index of the last pad entry.
221 =for apidoc Amx|char *|PadnamePV|PADNAME * pn
222 The name stored in the pad name struct. This returns C<NULL> for a target
225 =for apidoc Amx|STRLEN|PadnameLEN|PADNAME * pn
226 The length of the name.
228 =for apidoc Amx|bool|PadnameUTF8|PADNAME * pn
229 Whether PadnamePV is in UTF-8. Currently, this is always true.
231 =for apidoc Amx|SV *|PadnameSV|PADNAME * pn
232 Returns the pad name as a mortal SV.
234 =for apidoc m|bool|PadnameIsOUR|PADNAME * pn
235 Whether this is an "our" variable.
237 =for apidoc m|HV *|PadnameOURSTASH
238 The stash in which this "our" variable was declared.
240 =for apidoc m|bool|PadnameOUTER|PADNAME * pn
241 Whether this entry belongs to an outer pad. Entries for which this is true
242 are often referred to as 'fake'.
244 =for apidoc m|bool|PadnameIsSTATE|PADNAME * pn
245 Whether this is a "state" variable.
247 =for apidoc m|HV *|PadnameTYPE|PADNAME * pn
248 The stash associated with a typed lexical. This returns the C<%Foo::> hash
251 =for apidoc Amx|SSize_t|PadnameREFCNT|PADNAME * pn
252 The reference count of the pad name.
254 =for apidoc Amx|void|PadnameREFCNT_dec|PADNAME * pn
255 Lowers the reference count of the pad name.
258 =for apidoc m|SV *|PAD_SETSV |PADOFFSET po|SV* sv
259 Set the slot at offset C<po> in the current pad to C<sv>
261 =for apidoc m|SV *|PAD_SV |PADOFFSET po
262 Get the value at offset C<po> in the current pad
264 =for apidoc m|SV *|PAD_SVl |PADOFFSET po
265 Lightweight and lvalue version of C<PAD_SV>.
266 Get or set the value at offset C<po> in the current pad.
267 Unlike C<PAD_SV>, does not print diagnostics with -DX.
268 For internal use only.
270 =for apidoc m|SV *|PAD_BASE_SV |PADLIST padlist|PADOFFSET po
271 Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
273 =for apidoc m|void|PAD_SET_CUR |PADLIST padlist|I32 n
274 Set the current pad to be pad C<n> in the padlist, saving
275 the previous current pad. NB currently this macro expands to a string too
276 long for some compilers, so it's best to replace it with
279 PAD_SET_CUR_NOSAVE(padlist,n);
282 =for apidoc m|void|PAD_SET_CUR_NOSAVE |PADLIST padlist|I32 n
283 like PAD_SET_CUR, but without the save
285 =for apidoc m|void|PAD_SAVE_SETNULLPAD
286 Save the current pad then set it to null.
288 =for apidoc m|void|PAD_SAVE_LOCAL|PAD *opad|PAD *npad
289 Save the current pad to the local variable C<opad>, then make the
290 current pad equal to C<npad>
292 =for apidoc m|void|PAD_RESTORE_LOCAL|PAD *opad
293 Restore the old pad saved into the local variable C<opad> by C<PAD_SAVE_LOCAL()>
298 #define PadlistARRAY(pl) (pl)->xpadl_arr.xpadlarr_alloc
299 #define PadlistMAX(pl) (pl)->xpadl_max
300 #define PadlistNAMES(pl) *((PADNAMELIST **)PadlistARRAY(pl))
301 #define PadlistNAMESARRAY(pl) PadnamelistARRAY(PadlistNAMES(pl))
302 #define PadlistNAMESMAX(pl) PadnamelistMAX(PadlistNAMES(pl))
303 #define PadlistREFCNT(pl) 1 /* reserved for future use */
305 #define PadnamelistARRAY(pnl) (pnl)->xpadnl_alloc
306 #define PadnamelistMAX(pnl) (pnl)->xpadnl_fill
307 #define PadnamelistMAXNAMED(pnl) (pnl)->xpadnl_max_named
308 #define PadnamelistREFCNT(pnl) (pnl)->xpadnl_refcnt
309 #define PadnamelistREFCNT_dec(pnl) Perl_padnamelist_free(aTHX_ pnl)
311 #define PadARRAY(pad) AvARRAY(pad)
312 #define PadMAX(pad) AvFILLp(pad)
314 #define PadnamePV(pn) (pn)->xpadn_pv
315 #define PadnameLEN(pn) (pn)->xpadn_len
316 #define PadnameUTF8(pn) 1
317 #define PadnameSV(pn) \
318 newSVpvn_flags(PadnamePV(pn), PadnameLEN(pn), SVs_TEMP|SVf_UTF8)
319 #define PadnameFLAGS(pn) (pn)->xpadn_flags
320 #define PadnameIsOUR(pn) (!!(pn)->xpadn_ourstash)
321 #define PadnameOURSTASH(pn) (pn)->xpadn_ourstash
322 #define PadnameTYPE(pn) (pn)->xpadn_type_u.xpadn_typestash
323 #define PadnamePROTOCV(pn) (pn)->xpadn_type_u.xpadn_protocv
324 #define PadnameREFCNT(pn) (pn)->xpadn_refcnt
325 #define PadnameREFCNT_dec(pn) Perl_padname_free(aTHX_ pn)
326 #define PadnameOURSTASH_set(pn,s) (PadnameOURSTASH(pn) = (s))
327 #define PadnameTYPE_set(pn,s) (PadnameTYPE(pn) = (s))
328 #define PadnameOUTER(pn) (PadnameFLAGS(pn) & PADNAMEt_OUTER)
329 #define PadnameIsSTATE(pn) (PadnameFLAGS(pn) & PADNAMEt_STATE)
330 #define PadnameLVALUE(pn) (PadnameFLAGS(pn) & PADNAMEt_LVALUE)
332 #define PadnameLVALUE_on(pn) (PadnameFLAGS(pn) |= PADNAMEt_LVALUE)
333 #define PadnameIsSTATE_on(pn) (PadnameFLAGS(pn) |= PADNAMEt_STATE)
335 #define PADNAMEt_OUTER 1 /* outer lexical var */
336 #define PADNAMEt_STATE 2 /* state var */
337 #define PADNAMEt_LVALUE 4 /* used as lvalue */
338 #define PADNAMEt_TYPED 8 /* for B; unused by core */
339 #define PADNAMEt_OUR 16 /* for B; unused by core */
341 /* backward compatibility */
342 #define SvPAD_STATE PadnameIsSTATE
343 #define SvPAD_TYPED(pn) (!!PadnameTYPE(pn))
344 #define SvPAD_OUR(pn) (!!PadnameOURSTASH(pn))
345 #define SvPAD_STATE_on PadnameIsSTATE_on
346 #define SvPAD_TYPED_on(pn) (PadnameFLAGS(pn) |= PADNAMEt_TYPED)
347 #define SvPAD_OUR_on(pn) (PadnameFLAGS(pn) |= PADNAMEt_OUR)
348 #define SvOURSTASH PadnameOURSTASH
349 #define SvOURSTASH_set PadnameOURSTASH_set
350 #define SVpad_STATE PADNAMEt_STATE
351 #define SVpad_TYPED PADNAMEt_TYPED
352 #define SVpad_OUR PADNAMEt_OUR
355 # define PAD_SV(po) pad_sv(po)
356 # define PAD_SETSV(po,sv) pad_setsv(po,sv)
358 # define PAD_SV(po) (PL_curpad[po])
359 # define PAD_SETSV(po,sv) PL_curpad[po] = (sv)
362 #define PAD_SVl(po) (PL_curpad[po])
364 #define PAD_BASE_SV(padlist, po) \
365 (PadlistARRAY(padlist)[1]) \
366 ? AvARRAY(MUTABLE_AV((PadlistARRAY(padlist)[1])))[po] \
370 #define PAD_SET_CUR_NOSAVE(padlist,nth) \
371 PL_comppad = (PAD*) (PadlistARRAY(padlist)[nth]); \
372 PL_curpad = AvARRAY(PL_comppad); \
373 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
374 "Pad 0x%" UVxf "[0x%" UVxf "] set_cur depth=%d\n", \
375 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (int)(nth)));
378 #define PAD_SET_CUR(padlist,nth) \
380 PAD_SET_CUR_NOSAVE(padlist,nth);
383 #define PAD_SAVE_SETNULLPAD() SAVECOMPPAD(); \
384 PL_comppad = NULL; PL_curpad = NULL; \
385 DEBUG_Xv(PerlIO_printf(Perl_debug_log, "Pad set_null\n"));
387 #define PAD_SAVE_LOCAL(opad,npad) \
389 PL_comppad = (npad); \
390 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
391 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
392 "Pad 0x%" UVxf "[0x%" UVxf "] save_local\n", \
393 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
395 #define PAD_RESTORE_LOCAL(opad) \
396 assert(!opad || !SvIS_FREED(opad)); \
398 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
399 DEBUG_Xv(PerlIO_printf(Perl_debug_log, \
400 "Pad 0x%" UVxf "[0x%" UVxf "] restore_local\n", \
401 PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
405 =for apidoc m|void|CX_CURPAD_SAVE|struct context
406 Save the current pad in the given context block structure.
408 =for apidoc m|SV *|CX_CURPAD_SV|struct context|PADOFFSET po
409 Access the SV at offset C<po> in the saved current pad in the given
410 context block structure (can be used as an lvalue).
415 #define CX_CURPAD_SAVE(block) (block).oldcomppad = PL_comppad
416 #define CX_CURPAD_SV(block,po) (AvARRAY(MUTABLE_AV(((block).oldcomppad)))[po])
420 =for apidoc m|U32|PAD_COMPNAME_FLAGS|PADOFFSET po
421 Return the flags for the current compiling pad name
422 at offset C<po>. Assumes a valid slot entry.
424 =for apidoc m|char *|PAD_COMPNAME_PV|PADOFFSET po
425 Return the name of the current compiling pad name
426 at offset C<po>. Assumes a valid slot entry.
428 =for apidoc m|HV *|PAD_COMPNAME_TYPE|PADOFFSET po
429 Return the type (stash) of the current compiling pad name at offset
430 C<po>. Must be a valid name. Returns null if not typed.
432 =for apidoc m|HV *|PAD_COMPNAME_OURSTASH|PADOFFSET po
433 Return the stash associated with an C<our> variable.
434 Assumes the slot entry is a valid C<our> lexical.
436 =for apidoc m|STRLEN|PAD_COMPNAME_GEN|PADOFFSET po
437 The generation number of the name at offset C<po> in the current
438 compiling pad (lvalue).
440 =for apidoc m|STRLEN|PAD_COMPNAME_GEN_set|PADOFFSET po|int gen
441 Sets the generation number of the name at offset C<po> in the current
442 ling pad (lvalue) to C<gen>.
447 #define PAD_COMPNAME(po) PAD_COMPNAME_SV(po)
448 #define PAD_COMPNAME_SV(po) (PadnamelistARRAY(PL_comppad_name)[(po)])
449 #define PAD_COMPNAME_FLAGS(po) PadnameFLAGS(PAD_COMPNAME(po))
450 #define PAD_COMPNAME_FLAGS_isOUR(po) SvPAD_OUR(PAD_COMPNAME_SV(po))
451 #define PAD_COMPNAME_PV(po) PadnamePV(PAD_COMPNAME(po))
453 #define PAD_COMPNAME_TYPE(po) PadnameTYPE(PAD_COMPNAME(po))
455 #define PAD_COMPNAME_OURSTASH(po) \
456 (SvOURSTASH(PAD_COMPNAME_SV(po)))
458 #define PAD_COMPNAME_GEN(po) \
459 ((STRLEN)PadnamelistARRAY(PL_comppad_name)[po]->xpadn_gen)
461 #define PAD_COMPNAME_GEN_set(po, gen) \
462 (PadnamelistARRAY(PL_comppad_name)[po]->xpadn_gen = (gen))
466 =for apidoc m|void|PAD_CLONE_VARS|PerlInterpreter *proto_perl|CLONE_PARAMS* param
467 Clone the state variables associated with running and compiling pads.
472 /* NB - we set PL_comppad to null unless it points at a value that
473 * has already been dup'ed, ie it points to part of an active padlist.
474 * Otherwise PL_comppad ends up being a leaked scalar in code like
476 * threads->create(sub { threads->create(sub {...} ) } );
477 * where the second thread dups the outer sub's comppad but not the
478 * sub's CV or padlist. */
480 #define PAD_CLONE_VARS(proto_perl, param) \
481 PL_comppad = av_dup(proto_perl->Icomppad, param); \
482 PL_curpad = PL_comppad ? AvARRAY(PL_comppad) : NULL; \
484 padnamelist_dup(proto_perl->Icomppad_name, param); \
485 PL_comppad_name_fill = proto_perl->Icomppad_name_fill; \
486 PL_comppad_name_floor = proto_perl->Icomppad_name_floor; \
487 PL_min_intro_pending = proto_perl->Imin_intro_pending; \
488 PL_max_intro_pending = proto_perl->Imax_intro_pending; \
489 PL_padix = proto_perl->Ipadix; \
490 PL_padix_floor = proto_perl->Ipadix_floor; \
491 PL_pad_reset_pending = proto_perl->Ipad_reset_pending; \
492 PL_cop_seqmax = proto_perl->Icop_seqmax;
495 =for apidoc Am|PADOFFSET|pad_add_name_pvs|"literal string" name|U32 flags|HV *typestash|HV *ourstash
497 Exactly like L</pad_add_name_pvn>, but takes a literal string
498 instead of a string/length pair.
503 #define pad_add_name_pvs(name,flags,typestash,ourstash) \
504 Perl_pad_add_name_pvn(aTHX_ STR_WITH_LEN(name), flags, typestash, ourstash)
507 =for apidoc Am|PADOFFSET|pad_findmy_pvs|"literal string" name|U32 flags
509 Exactly like L</pad_findmy_pvn>, but takes a literal string
510 instead of a string/length pair.
515 #define pad_findmy_pvs(name,flags) \
516 Perl_pad_findmy_pvn(aTHX_ STR_WITH_LEN(name), flags)
519 * ex: set ts=8 sts=4 sw=4 et: