Version bumps for POSIX non-dual-life modules identified by
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a PL_start_env initialized when perl starts, and
18  * PL_top_env points to this initially, so PL_top_env should always be
19  * non-null.
20  *
21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
23  * null to ensure this).
24  *
25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
26  * establish a local jmpenv to handle exception traps.  Care must be taken
27  * to restore the previous value of je_mustcatch before exiting the
28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
29  * GSAR 97-03-27
30  */
31
32 struct jmpenv {
33     struct jmpenv *     je_prev;
34     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
35     int                 je_ret;         /* last exception thrown */
36     bool                je_mustcatch;   /* need to call longjmp()? */
37 };
38
39 typedef struct jmpenv JMPENV;
40
41 #ifdef OP_IN_REGISTER
42 #define OP_REG_TO_MEM   PL_opsave = op
43 #define OP_MEM_TO_REG   op = PL_opsave
44 #else
45 #define OP_REG_TO_MEM   NOOP
46 #define OP_MEM_TO_REG   NOOP
47 #endif
48
49 /*
50  * How to build the first jmpenv.
51  *
52  * top_env needs to be non-zero. It points to an area
53  * in which longjmp() stuff is stored, as C callstack
54  * info there at least is thread specific this has to
55  * be per-thread. Otherwise a 'die' in a thread gives
56  * that thread the C stack of last thread to do an eval {}!
57  */
58
59 #define JMPENV_BOOTSTRAP \
60     STMT_START {                                \
61         Zero(&PL_start_env, 1, JMPENV);         \
62         PL_start_env.je_ret = -1;               \
63         PL_start_env.je_mustcatch = TRUE;       \
64         PL_top_env = &PL_start_env;             \
65     } STMT_END
66
67 /*
68  *   PERL_FLEXIBLE_EXCEPTIONS
69  * 
70  * All the flexible exceptions code has been removed.
71  * See the following threads for details:
72  *
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
74  * 
75  * Joshua's original patches (which weren't applied) and discussion:
76  * 
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
82  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
83  * 
84  * Chip's reworked patch and discussion:
85  * 
86  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
87  * 
88  * The flaw in these patches (which went unnoticed at the time) was
89  * that they moved some code that could potentially die() out of the
90  * region protected by the setjmp()s.  This caused exceptions within
91  * END blocks and such to not be handled by the correct setjmp().
92  * 
93  * The original patches that introduces flexible exceptions were:
94  *
95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
96  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
97  */
98
99 #define dJMPENV         JMPENV cur_env
100
101 #define JMPENV_PUSH(v) \
102     STMT_START {                                                        \
103         DEBUG_l({                                                       \
104             int i = 0; JMPENV *p = PL_top_env;                          \
105             while (p) { i++; p = p->je_prev; }                          \
106             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
107                          i,  __FILE__, __LINE__);})                     \
108         cur_env.je_prev = PL_top_env;                                   \
109         OP_REG_TO_MEM;                                                  \
110         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
111         OP_MEM_TO_REG;                                                  \
112         PL_top_env = &cur_env;                                          \
113         cur_env.je_mustcatch = FALSE;                                   \
114         (v) = cur_env.je_ret;                                           \
115     } STMT_END
116
117 #define JMPENV_POP \
118     STMT_START {                                                        \
119         DEBUG_l({                                                       \
120             int i = -1; JMPENV *p = PL_top_env;                         \
121             while (p) { i++; p = p->je_prev; }                          \
122             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
123                          i, __FILE__, __LINE__);})                      \
124         assert(PL_top_env == &cur_env);                                 \
125         PL_top_env = cur_env.je_prev;                                   \
126     } STMT_END
127
128 #define JMPENV_JUMP(v) \
129     STMT_START {                                                \
130         DEBUG_l({                                               \
131             int i = -1; JMPENV *p = PL_top_env;                 \
132             while (p) { i++; p = p->je_prev; }                  \
133             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
134                          (int)v, i, __FILE__, __LINE__);})      \
135         OP_REG_TO_MEM;                                          \
136         if (PL_top_env->je_prev)                                \
137             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
138         if ((v) == 2)                                           \
139             PerlProc_exit(STATUS_EXIT);                         \
140         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
141         PerlProc_exit(1);                                       \
142     } STMT_END
143
144 #define CATCH_GET               (PL_top_env->je_mustcatch)
145 #define CATCH_SET(v) \
146     STMT_START {                                                        \
147         DEBUG_l(                                                        \
148             Perl_deb(aTHX_                                              \
149                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
150                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
151                  __FILE__, __LINE__);)                                  \
152         PL_top_env->je_mustcatch = (v);                                 \
153     } STMT_END
154
155 /*
156 =head1 COP Hint Hashes
157 */
158
159 typedef struct refcounted_he COPHH;
160
161 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
162
163 /*
164 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
165
166 Look up the entry in the cop hints hash I<cophh> with the key specified by
167 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
168 the key octets are interpreted as UTF-8, otherwise they are interpreted
169 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
170 it has not been precomputed.  Returns a mortal scalar copy of the value
171 associated with the key, or C<&PL_sv_placeholder> if there is no value
172 associated with the key.
173
174 =cut
175 */
176
177 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
178     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
179
180 /*
181 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
182
183 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
184 string/length pair, and no precomputed hash.
185
186 =cut
187 */
188
189 #define cophh_fetch_pvs(cophh, key, flags) \
190     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
191
192 /*
193 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
194
195 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
196 a string/length pair.
197
198 =cut
199 */
200
201 #define cophh_fetch_pv(cophh, key, hash, flags) \
202     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
203
204 /*
205 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
206
207 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
208 string/length pair.
209
210 =cut
211 */
212
213 #define cophh_fetch_sv(cophh, key, hash, flags) \
214     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
215
216 /*
217 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
218
219 Generates and returns a standard Perl hash representing the full set of
220 key/value pairs in the cop hints hash I<cophh>.  I<flags> is currently
221 unused and must be zero.
222
223 =cut
224 */
225
226 #define cophh_2hv(cophh, flags) \
227     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
228
229 /*
230 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
231
232 Make and return a complete copy of the cop hints hash I<cophh>.
233
234 =cut
235 */
236
237 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
238
239 /*
240 =for apidoc Amx|void|cophh_free|COPHH *cophh
241
242 Discard the cop hints hash I<cophh>, freeing all resources associated
243 with it.
244
245 =cut
246 */
247
248 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
249
250 /*
251 =for apidoc Amx|COPHH *|cophh_new_empty
252
253 Generate and return a fresh cop hints hash containing no entries.
254
255 =cut
256 */
257
258 #define cophh_new_empty() ((COPHH *)NULL)
259
260 /*
261 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
262
263 Stores a value, associated with a key, in the cop hints hash I<cophh>,
264 and returns the modified hash.  The returned hash pointer is in general
265 not the same as the hash pointer that was passed in.  The input hash is
266 consumed by the function, and the pointer to it must not be subsequently
267 used.  Use L</cophh_copy> if you need both hashes.
268
269 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
270 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
271 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
272 hash of the key string, or zero if it has not been precomputed.
273
274 I<value> is the scalar value to store for this key.  I<value> is copied
275 by this function, which thus does not take ownership of any reference
276 to it, and later changes to the scalar will not be reflected in the
277 value visible in the cop hints hash.  Complex types of scalar will not
278 be stored with referential integrity, but will be coerced to strings.
279
280 =cut
281 */
282
283 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
284     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
285
286 /*
287 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
288
289 Like L</cophh_store_pvn>, but takes a literal string instead of a
290 string/length pair, and no precomputed hash.
291
292 =cut
293 */
294
295 #define cophh_store_pvs(cophh, key, value, flags) \
296     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
297
298 /*
299 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
300
301 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
302 a string/length pair.
303
304 =cut
305 */
306
307 #define cophh_store_pv(cophh, key, hash, value, flags) \
308     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
309
310 /*
311 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
312
313 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
314 string/length pair.
315
316 =cut
317 */
318
319 #define cophh_store_sv(cophh, key, hash, value, flags) \
320     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
321
322 /*
323 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
324
325 Delete a key and its associated value from the cop hints hash I<cophh>,
326 and returns the modified hash.  The returned hash pointer is in general
327 not the same as the hash pointer that was passed in.  The input hash is
328 consumed by the function, and the pointer to it must not be subsequently
329 used.  Use L</cophh_copy> if you need both hashes.
330
331 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
332 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
333 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
334 hash of the key string, or zero if it has not been precomputed.
335
336 =cut
337 */
338
339 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
340     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
341         (SV *)NULL, flags)
342
343 /*
344 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
345
346 Like L</cophh_delete_pvn>, but takes a literal string instead of a
347 string/length pair, and no precomputed hash.
348
349 =cut
350 */
351
352 #define cophh_delete_pvs(cophh, key, flags) \
353     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
354         (SV *)NULL, flags)
355
356 /*
357 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
358
359 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
360 a string/length pair.
361
362 =cut
363 */
364
365 #define cophh_delete_pv(cophh, key, hash, flags) \
366     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
367
368 /*
369 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
370
371 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
372 string/length pair.
373
374 =cut
375 */
376
377 #define cophh_delete_sv(cophh, key, hash, flags) \
378     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
379
380 #include "mydtrace.h"
381
382 struct cop {
383     BASEOP
384     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
385        an exact multiple of 8 bytes to save structure padding.  */
386     line_t      cop_line;       /* line # of this command */
387     /* label for this construct is now stored in cop_hints_hash */
388 #ifdef USE_ITHREADS
389     char *      cop_stashpv;    /* package line was compiled in */
390     char *      cop_file;       /* file name the following line # is from */
391 #else
392     HV *        cop_stash;      /* package line was compiled in */
393     GV *        cop_filegv;     /* file the following line # is from */
394 #endif
395     U32         cop_hints;      /* hints bits from pragmata */
396     U32         cop_seq;        /* parse sequence number */
397     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
398     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
399     /* compile time state of %^H.  See the comment in op.c for how this is
400        used to recreate a hash to return from caller.  */
401     COPHH *     cop_hints_hash;
402 };
403
404 #ifdef USE_ITHREADS
405 #  define CopFILE(c)            ((c)->cop_file)
406 #  define CopFILEGV(c)          (CopFILE(c) \
407                                  ? gv_fetchfile(CopFILE(c)) : NULL)
408                                  
409 #  ifdef NETWARE
410 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
411 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
412 #  else
413 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
414 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
415 #  endif
416
417 #  define CopFILESV(c)          (CopFILE(c) \
418                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
419 #  define CopFILEAV(c)          (CopFILE(c) \
420                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
421 #  ifdef DEBUGGING
422 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
423                                    GvAV(gv_fetchfile(CopFILE(c))))
424 #  else
425 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
426 #  endif
427 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
428
429 #  ifdef NETWARE
430 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
431 #  else
432 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
433 #  endif
434
435 #  define CopSTASH(c)           (CopSTASHPV(c) \
436                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
437 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
438 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
439 #  ifdef NETWARE
440 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
441 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
442 #  else
443 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
444 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
445 #  endif
446 #else
447 #  define CopFILEGV(c)          ((c)->cop_filegv)
448 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
449 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
450 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
451 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
452 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
453 #  ifdef DEBUGGING
454 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
455 #  else
456 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
457 # endif
458 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
459                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
460 #  define CopSTASH(c)           ((c)->cop_stash)
461 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
462 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
463    /* cop_stash is not refcounted */
464 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
465 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
466 #  define CopSTASH_free(c)      
467 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
468
469 #endif /* USE_ITHREADS */
470
471 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
472 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
473
474 /*
475 =head1 COP Hint Reading
476 */
477
478 /*
479 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
480
481 Look up the hint entry in the cop I<cop> with the key specified by
482 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
483 the key octets are interpreted as UTF-8, otherwise they are interpreted
484 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
485 it has not been precomputed.  Returns a mortal scalar copy of the value
486 associated with the key, or C<&PL_sv_placeholder> if there is no value
487 associated with the key.
488
489 =cut
490 */
491
492 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
493     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
494
495 /*
496 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
497
498 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
499 string/length pair, and no precomputed hash.
500
501 =cut
502 */
503
504 #define cop_hints_fetch_pvs(cop, key, flags) \
505     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
506
507 /*
508 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
509
510 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
511 of a string/length pair.
512
513 =cut
514 */
515
516 #define cop_hints_fetch_pv(cop, key, hash, flags) \
517     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
518
519 /*
520 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
521
522 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
523 string/length pair.
524
525 =cut
526 */
527
528 #define cop_hints_fetch_sv(cop, key, hash, flags) \
529     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
530
531 /*
532 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
533
534 Generates and returns a standard Perl hash representing the full set of
535 hint entries in the cop I<cop>.  I<flags> is currently unused and must
536 be zero.
537
538 =cut
539 */
540
541 #define cop_hints_2hv(cop, flags) \
542     cophh_2hv(CopHINTHASH_get(cop), flags)
543
544 #define CopLABEL(c)  Perl_fetch_cop_label(aTHX_ (c), NULL, NULL)
545 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
546
547 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
548 #define CopLINE(c)              ((c)->cop_line)
549 #define CopLINE_inc(c)          (++CopLINE(c))
550 #define CopLINE_dec(c)          (--CopLINE(c))
551 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
552
553 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
554 #define OutCopFILE(c) CopFILE(c)
555
556 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
557    HINT_ARYBASE is set to indicate this.
558    Setting it is inefficient due to the need to create 2 mortal SVs, but as
559    using $[ is highly discouraged, no sane Perl code will be using it.  */
560 #define CopARYBASE_get(c)       \
561         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
562          ? SvIV(cop_hints_fetch_pvs((c), "$[", 0))                      \
563          : 0)
564 #define CopARYBASE_set(c, b) STMT_START { \
565         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
566             (c)->cop_hints |= HINT_ARYBASE;                             \
567             if ((c) == &PL_compiling) {                                 \
568                 SV *val = newSViv(b);                                   \
569                 (void)hv_stores(GvHV(PL_hintgv), "$[", val);            \
570                 mg_set(val);                                            \
571                 PL_hints |= HINT_ARYBASE;                               \
572             } else {                                                    \
573                 CopHINTHASH_set((c),                                    \
574                     cophh_store_pvs(CopHINTHASH_get((c)), "$[",         \
575                         sv_2mortal(newSViv(b)), 0));                    \
576             }                                                           \
577         }                                                               \
578     } STMT_END
579
580 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
581 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
582 #define CopHINTS_set(c, h)      STMT_START {                            \
583                                     (c)->cop_hints = (h);               \
584                                 } STMT_END
585
586 /*
587  * Here we have some enormously heavy (or at least ponderous) wizardry.
588  */
589
590 /* subroutine context */
591 struct block_sub {
592     OP *        retop;  /* op to execute on exit from sub */
593     /* Above here is the same for sub, format and eval.  */
594     CV *        cv;
595     /* Above here is the same for sub and format.  */
596     AV *        savearray;
597     AV *        argarray;
598     I32         olddepth;
599     PAD         *oldcomppad;
600 };
601
602
603 /* format context */
604 struct block_format {
605     OP *        retop;  /* op to execute on exit from sub */
606     /* Above here is the same for sub, format and eval.  */
607     CV *        cv;
608     /* Above here is the same for sub and format.  */
609     GV *        gv;
610     GV *        dfoutgv;
611 };
612
613 /* base for the next two macros. Don't use directly.
614  * Note that the refcnt of the cv is incremented twice;  The CX one is
615  * decremented by LEAVESUB, the other by LEAVE. */
616
617 #define PUSHSUB_BASE(cx)                                                \
618         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
619                 CopFILE((const COP *)CvSTART(cv)),                      \
620                 CopLINE((const COP *)CvSTART(cv)),                      \
621                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
622                                                                         \
623         cx->blk_sub.cv = cv;                                            \
624         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
625         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
626         cx->blk_sub.retop = NULL;                                       \
627         if (!CvDEPTH(cv)) {                                             \
628             SvREFCNT_inc_simple_void_NN(cv);                            \
629             SvREFCNT_inc_simple_void_NN(cv);                            \
630             SAVEFREESV(cv);                                             \
631         }
632
633
634 #define PUSHSUB(cx)                                                     \
635         PUSHSUB_BASE(cx)                                                \
636         cx->blk_u16 = PL_op->op_private &                               \
637                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
638
639 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
640 #define PUSHSUB_DB(cx)                                                  \
641         PUSHSUB_BASE(cx)                                                \
642         cx->blk_u16 = 0;
643
644
645 #define PUSHFORMAT(cx, retop)                                           \
646         cx->blk_format.cv = cv;                                         \
647         cx->blk_format.gv = gv;                                         \
648         cx->blk_format.retop = (retop);                                 \
649         cx->blk_format.dfoutgv = PL_defoutgv;                           \
650         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
651
652 #define POP_SAVEARRAY()                                         \
653     STMT_START {                                                        \
654         SvREFCNT_dec(GvAV(PL_defgv));                                   \
655         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
656     } STMT_END
657
658 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
659  * leave any (a fast av_clear(ary), basically) */
660 #define CLEAR_ARGARRAY(ary) \
661     STMT_START {                                                        \
662         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
663         AvARRAY(ary) = AvALLOC(ary);                                    \
664         AvFILLp(ary) = -1;                                              \
665     } STMT_END
666
667 #define POPSUB(cx,sv)                                                   \
668     STMT_START {                                                        \
669         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
670                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
671                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
672                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
673                                                                         \
674         if (CxHASARGS(cx)) {                                            \
675             POP_SAVEARRAY();                                            \
676             /* abandon @_ if it got reified */                          \
677             if (AvREAL(cx->blk_sub.argarray)) {                         \
678                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
679                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
680                 cx->blk_sub.argarray = newAV();                         \
681                 av_extend(cx->blk_sub.argarray, fill);                  \
682                 AvREIFY_only(cx->blk_sub.argarray);                     \
683                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
684             }                                                           \
685             else {                                                      \
686                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
687             }                                                           \
688         }                                                               \
689         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
690         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
691             sv = NULL;                                          \
692     } STMT_END
693
694 #define LEAVESUB(sv)                                                    \
695     STMT_START {                                                        \
696         if (sv)                                                         \
697             SvREFCNT_dec(sv);                                           \
698     } STMT_END
699
700 #define POPFORMAT(cx)                                                   \
701         setdefout(cx->blk_format.dfoutgv);                              \
702         SvREFCNT_dec(cx->blk_format.dfoutgv);
703
704 /* eval context */
705 struct block_eval {
706     OP *        retop;  /* op to execute on exit from eval */
707     /* Above here is the same for sub, format and eval.  */
708     SV *        old_namesv;
709     OP *        old_eval_root;
710     SV *        cur_text;
711     CV *        cv;
712     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
713 };
714
715 /* If we ever need more than 512 op types, change the shift from 7.
716    blku_gimme is actually also only 2 bits, so could be merged with something.
717 */
718
719 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
720 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
721
722 #define PUSHEVAL(cx,n)                                                  \
723     STMT_START {                                                        \
724         assert(!(PL_in_eval & ~0x7F));                                  \
725         assert(!(PL_op->op_type & ~0x1FF));                             \
726         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
727         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
728         cx->blk_eval.old_eval_root = PL_eval_root;                      \
729         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
730         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
731         cx->blk_eval.retop = NULL;                                      \
732         cx->blk_eval.cur_top_env = PL_top_env;                          \
733     } STMT_END
734
735 #define POPEVAL(cx)                                                     \
736     STMT_START {                                                        \
737         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
738         optype = CxOLD_OP_TYPE(cx);                                     \
739         PL_eval_root = cx->blk_eval.old_eval_root;                      \
740         if (cx->blk_eval.old_namesv)                                    \
741             sv_2mortal(cx->blk_eval.old_namesv);                        \
742     } STMT_END
743
744 /* loop context */
745 struct block_loop {
746     I32         resetsp;
747     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
748     union {     /* different ways of locating the iteration variable */
749         SV      **svp;
750         GV      *gv;
751         PAD     *oldcomppad; /* only used in ITHREADS */
752     } itervar_u;
753     union {
754         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
755             AV * ary; /* use the stack if this is NULL */
756             IV ix;
757         } ary;
758         struct { /* valid if type is LOOP_LAZYIV */
759             IV cur;
760             IV end;
761         } lazyiv;
762         struct { /* valid if type if LOOP_LAZYSV */
763             SV * cur;
764             SV * end; /* maxiumum value (or minimum in reverse) */
765         } lazysv;
766     } state_u;
767 };
768
769 #ifdef USE_ITHREADS
770 #  define CxITERVAR_PADSV(c) \
771         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
772 #else
773 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
774 #endif
775
776 #define CxITERVAR(c)                                                    \
777         ((c)->blk_loop.itervar_u.oldcomppad                             \
778          ? (CxPADLOOP(c)                                                \
779             ? CxITERVAR_PADSV(c)                                        \
780             : &GvSV((c)->blk_loop.itervar_u.gv))                        \
781          : (SV**)NULL)
782
783 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
784 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
785 #define CxLVAL(c)       (0 + (c)->blk_u16)
786
787 #define PUSHLOOP_PLAIN(cx, s)                                           \
788         cx->blk_loop.resetsp = s - PL_stack_base;                       \
789         cx->blk_loop.my_op = cLOOP;                                     \
790         cx->blk_loop.state_u.ary.ary = NULL;                            \
791         cx->blk_loop.state_u.ary.ix = 0;                                \
792         cx->blk_loop.itervar_u.svp = NULL;
793
794 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
795         cx->blk_loop.resetsp = s - PL_stack_base;                       \
796         cx->blk_loop.my_op = cLOOP;                                     \
797         cx->blk_loop.state_u.ary.ary = NULL;                            \
798         cx->blk_loop.state_u.ary.ix = 0;                                \
799         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
800
801 #define POPLOOP(cx)                                                     \
802         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
803             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
804             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
805         }                                                               \
806         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
807             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
808
809 /* given/when context */
810 struct block_givwhen {
811         OP *leave_op;
812 };
813
814 #define PUSHGIVEN(cx)                                                   \
815         cx->blk_givwhen.leave_op = cLOGOP->op_other;
816
817 #define PUSHWHEN PUSHGIVEN
818
819 /* context common to subroutines, evals and loops */
820 struct block {
821     U8          blku_type;      /* what kind of context this is */
822     U8          blku_gimme;     /* is this block running in list context? */
823     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
824     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
825     COP *       blku_oldcop;    /* old curcop pointer */
826     I32         blku_oldmarksp; /* mark stack index */
827     I32         blku_oldscopesp;        /* scope stack index */
828     PMOP *      blku_oldpm;     /* values of pattern match vars */
829
830     union {
831         struct block_sub        blku_sub;
832         struct block_format     blku_format;
833         struct block_eval       blku_eval;
834         struct block_loop       blku_loop;
835         struct block_givwhen    blku_givwhen;
836     } blk_u;
837 };
838 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
839 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
840 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
841 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
842 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
843 #define blk_gimme       cx_u.cx_blk.blku_gimme
844 #define blk_u16         cx_u.cx_blk.blku_u16
845 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
846 #define blk_format      cx_u.cx_blk.blk_u.blku_format
847 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
848 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
849 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
850
851 #define DEBUG_CX(action)                                                \
852     DEBUG_l(                                                            \
853         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
854                     (long)cxstack_ix,                                   \
855                     action,                                             \
856                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
857                     (long)PL_scopestack_ix,                             \
858                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
859                     __FILE__, __LINE__));
860
861 /* Enter a block. */
862 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
863         cx->cx_type             = t,                                    \
864         cx->blk_oldsp           = sp - PL_stack_base,                   \
865         cx->blk_oldcop          = PL_curcop,                            \
866         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
867         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
868         cx->blk_oldpm           = PL_curpm,                             \
869         cx->blk_gimme           = (U8)gimme;                            \
870         DEBUG_CX("PUSH");
871
872 /* Exit a block (RETURN and LAST). */
873 #define POPBLOCK(cx,pm)                                                 \
874         DEBUG_CX("POP");                                                \
875         cx = &cxstack[cxstack_ix--],                                    \
876         newsp            = PL_stack_base + cx->blk_oldsp,               \
877         PL_curcop        = cx->blk_oldcop,                              \
878         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
879         PL_scopestack_ix = cx->blk_oldscopesp,                          \
880         pm               = cx->blk_oldpm,                               \
881         gimme            = cx->blk_gimme;
882
883 /* Continue a block elsewhere (NEXT and REDO). */
884 #define TOPBLOCK(cx)                                                    \
885         DEBUG_CX("TOP");                                                \
886         cx  = &cxstack[cxstack_ix],                                     \
887         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
888         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
889         PL_scopestack_ix = cx->blk_oldscopesp,                          \
890         PL_curpm         = cx->blk_oldpm;
891
892 /* substitution context */
893 struct subst {
894     U8          sbu_type;       /* what kind of context this is */
895     U8          sbu_rflags;
896     U16         sbu_rxtainted;  /* matches struct block */
897     I32         sbu_iters;
898     I32         sbu_maxiters;
899     I32         sbu_oldsave;
900     char *      sbu_orig;
901     SV *        sbu_dstr;
902     SV *        sbu_targ;
903     char *      sbu_s;
904     char *      sbu_m;
905     char *      sbu_strend;
906     void *      sbu_rxres;
907     REGEXP *    sbu_rx;
908 };
909 #define sb_iters        cx_u.cx_subst.sbu_iters
910 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
911 #define sb_rflags       cx_u.cx_subst.sbu_rflags
912 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
913 #define sb_once         cx_u.cx_subst.sbu_once
914 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
915 #define sb_orig         cx_u.cx_subst.sbu_orig
916 #define sb_dstr         cx_u.cx_subst.sbu_dstr
917 #define sb_targ         cx_u.cx_subst.sbu_targ
918 #define sb_s            cx_u.cx_subst.sbu_s
919 #define sb_m            cx_u.cx_subst.sbu_m
920 #define sb_strend       cx_u.cx_subst.sbu_strend
921 #define sb_rxres        cx_u.cx_subst.sbu_rxres
922 #define sb_rx           cx_u.cx_subst.sbu_rx
923
924 #ifdef PERL_CORE
925 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
926         cx->sb_iters            = iters,                                \
927         cx->sb_maxiters         = maxiters,                             \
928         cx->sb_rflags           = r_flags,                              \
929         cx->sb_oldsave          = oldsave,                              \
930         cx->sb_rxtainted        = rxtainted,                            \
931         cx->sb_orig             = orig,                                 \
932         cx->sb_dstr             = dstr,                                 \
933         cx->sb_targ             = targ,                                 \
934         cx->sb_s                = s,                                    \
935         cx->sb_m                = m,                                    \
936         cx->sb_strend           = strend,                               \
937         cx->sb_rxres            = NULL,                                 \
938         cx->sb_rx               = rx,                                   \
939         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
940         rxres_save(&cx->sb_rxres, rx);                                  \
941         (void)ReREFCNT_inc(rx)
942
943 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
944         rxres_free(&cx->sb_rxres);                                      \
945         ReREFCNT_dec(cx->sb_rx)
946 #endif
947
948 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
949
950 struct context {
951     union {
952         struct block    cx_blk;
953         struct subst    cx_subst;
954     } cx_u;
955 };
956 #define cx_type cx_u.cx_subst.sbu_type
957
958 /* If you re-order these, there is also an array of uppercase names in perl.h
959    and a static array of context names in pp_ctl.c  */
960 #define CXTYPEMASK      0xf
961 #define CXt_NULL        0
962 #define CXt_WHEN        1
963 #define CXt_BLOCK       2
964 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
965    jump table in pp_ctl.c
966    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
967 */
968 #define CXt_GIVEN       3
969 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
970 #define CXt_LOOP_FOR    4
971 #define CXt_LOOP_PLAIN  5
972 #define CXt_LOOP_LAZYSV 6
973 #define CXt_LOOP_LAZYIV 7
974 #define CXt_SUB         8
975 #define CXt_FORMAT      9
976 #define CXt_EVAL       10
977 #define CXt_SUBST      11
978 /* SUBST doesn't feature in all switch statements.  */
979
980 /* private flags for CXt_SUB and CXt_NULL
981    However, this is checked in many places which do not check the type, so
982    this bit needs to be kept clear for most everything else. For reasons I
983    haven't investigated, it can coexist with CXp_FOR_DEF */
984 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
985                                    tear down context on exit). */ 
986
987 /* private flags for CXt_SUB and CXt_FORMAT */
988 #define CXp_HASARGS     0x20
989
990 /* private flags for CXt_EVAL */
991 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
992 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
993
994 /* private flags for CXt_LOOP */
995 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
996 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
997
998 /* private flags for CXt_SUBST */
999 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1000
1001 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1002 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1003 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
1004                          == CXp_MULTICALL)
1005 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1006                          == (CXt_EVAL|CXp_REAL))
1007 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1008                          == (CXt_EVAL|CXp_TRYBLOCK))
1009 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1010 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1011                          && ((c)->cx_type & CXp_FOR_DEF))
1012
1013 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1014
1015 /* 
1016 =head1 "Gimme" Values
1017 */
1018
1019 /*
1020 =for apidoc AmU||G_SCALAR
1021 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
1022 L<perlcall>.
1023
1024 =for apidoc AmU||G_ARRAY
1025 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
1026 L<perlcall>.
1027
1028 =for apidoc AmU||G_VOID
1029 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
1030
1031 =for apidoc AmU||G_DISCARD
1032 Indicates that arguments returned from a callback should be discarded.  See
1033 L<perlcall>.
1034
1035 =for apidoc AmU||G_EVAL
1036
1037 Used to force a Perl C<eval> wrapper around a callback.  See
1038 L<perlcall>.
1039
1040 =for apidoc AmU||G_NOARGS
1041
1042 Indicates that no arguments are being sent to a callback.  See
1043 L<perlcall>.
1044
1045 =cut
1046 */
1047
1048 #define G_SCALAR        2
1049 #define G_ARRAY         3
1050 #define G_VOID          1
1051 #define G_WANT          3
1052
1053 /* extra flags for Perl_call_* routines */
1054 #define G_DISCARD       4       /* Call FREETMPS.
1055                                    Don't change this without consulting the
1056                                    hash actions codes defined in hv.h */
1057 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1058 #define G_NOARGS       16       /* Don't construct a @_ array. */
1059 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1060 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1061 #define G_METHOD      128       /* Calling method. */
1062 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1063                                    fold_constants. */
1064 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1065                                    A special case for UNSHIFT in
1066                                    Perl_magic_methcall().  */
1067 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1068                                     Perl_magic_methcall().  */
1069
1070 /* flag bits for PL_in_eval */
1071 #define EVAL_NULL       0       /* not in an eval */
1072 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1073 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1074 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1075 #define EVAL_INREQUIRE  8       /* The code is being required. */
1076
1077 /* Support for switching (stack and block) contexts.
1078  * This ensures magic doesn't invalidate local stack and cx pointers.
1079  */
1080
1081 #define PERLSI_UNKNOWN          -1
1082 #define PERLSI_UNDEF            0
1083 #define PERLSI_MAIN             1
1084 #define PERLSI_MAGIC            2
1085 #define PERLSI_SORT             3
1086 #define PERLSI_SIGNAL           4
1087 #define PERLSI_OVERLOAD         5
1088 #define PERLSI_DESTROY          6
1089 #define PERLSI_WARNHOOK         7
1090 #define PERLSI_DIEHOOK          8
1091 #define PERLSI_REQUIRE          9
1092
1093 struct stackinfo {
1094     AV *                si_stack;       /* stack for current runlevel */
1095     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1096     struct stackinfo *  si_prev;
1097     struct stackinfo *  si_next;
1098     I32                 si_cxix;        /* current context index */
1099     I32                 si_cxmax;       /* maximum allocated index */
1100     I32                 si_type;        /* type of runlevel */
1101     I32                 si_markoff;     /* offset where markstack begins for us.
1102                                          * currently used only with DEBUGGING,
1103                                          * but not #ifdef-ed for bincompat */
1104 };
1105
1106 typedef struct stackinfo PERL_SI;
1107
1108 #define cxstack         (PL_curstackinfo->si_cxstack)
1109 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1110 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1111
1112 #ifdef DEBUGGING
1113 #  define       SET_MARK_OFFSET \
1114     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1115 #else
1116 #  define       SET_MARK_OFFSET NOOP
1117 #endif
1118
1119 #define PUSHSTACKi(type) \
1120     STMT_START {                                                        \
1121         PERL_SI *next = PL_curstackinfo->si_next;                       \
1122         DEBUG_l({                                                       \
1123             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1124             while (p) { i++; p = p->si_prev; }                          \
1125             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1126                          i, __FILE__, __LINE__);})                      \
1127         if (!next) {                                                    \
1128             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1129             next->si_prev = PL_curstackinfo;                            \
1130             PL_curstackinfo->si_next = next;                            \
1131         }                                                               \
1132         next->si_type = type;                                           \
1133         next->si_cxix = -1;                                             \
1134         AvFILLp(next->si_stack) = 0;                                    \
1135         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1136         PL_curstackinfo = next;                                         \
1137         SET_MARK_OFFSET;                                                \
1138     } STMT_END
1139
1140 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1141
1142 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1143  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1144 #define POPSTACK \
1145     STMT_START {                                                        \
1146         dSP;                                                            \
1147         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1148         DEBUG_l({                                                       \
1149             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1150             while (p) { i++; p = p->si_prev; }                          \
1151             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1152                          i, __FILE__, __LINE__);})                      \
1153         if (!prev) {                                                    \
1154             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
1155             my_exit(1);                                                 \
1156         }                                                               \
1157         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1158         /* don't free prev here, free them all at the END{} */          \
1159         PL_curstackinfo = prev;                                         \
1160     } STMT_END
1161
1162 #define POPSTACK_TO(s) \
1163     STMT_START {                                                        \
1164         while (PL_curstack != s) {                                      \
1165             dounwind(-1);                                               \
1166             POPSTACK;                                                   \
1167         }                                                               \
1168     } STMT_END
1169
1170 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1171 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1172
1173 /*
1174 =head1 Multicall Functions
1175
1176 =for apidoc Ams||dMULTICALL
1177 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
1178
1179 =for apidoc Ams||PUSH_MULTICALL
1180 Opening bracket for a lightweight callback.
1181 See L<perlcall/Lightweight Callbacks>.
1182
1183 =for apidoc Ams||MULTICALL
1184 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
1185
1186 =for apidoc Ams||POP_MULTICALL
1187 Closing bracket for a lightweight callback.
1188 See L<perlcall/Lightweight Callbacks>.
1189
1190 =cut
1191 */
1192
1193 #define dMULTICALL \
1194     SV **newsp;                 /* set by POPBLOCK */                   \
1195     PERL_CONTEXT *cx;                                                   \
1196     CV *multicall_cv;                                                   \
1197     OP *multicall_cop;                                                  \
1198     bool multicall_oldcatch;                                            \
1199     U8 hasargs = 0              /* used by PUSHSUB */
1200
1201 #define PUSH_MULTICALL(the_cv) \
1202     STMT_START {                                                        \
1203         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1204         CV * const cv = _nOnclAshIngNamE_;                              \
1205         AV * const padlist = CvPADLIST(cv);                             \
1206         ENTER;                                                          \
1207         multicall_oldcatch = CATCH_GET;                                 \
1208         SAVETMPS; SAVEVPTR(PL_op);                                      \
1209         CATCH_SET(TRUE);                                                \
1210         PUSHSTACKi(PERLSI_SORT);                                        \
1211         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
1212         PUSHSUB(cx);                                                    \
1213         if (++CvDEPTH(cv) >= 2) {                                       \
1214             PERL_STACK_OVERFLOW_CHECK();                                \
1215             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1216         }                                                               \
1217         SAVECOMPPAD();                                                  \
1218         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1219         multicall_cv = cv;                                              \
1220         multicall_cop = CvSTART(cv);                                    \
1221     } STMT_END
1222
1223 #define MULTICALL \
1224     STMT_START {                                                        \
1225         PL_op = multicall_cop;                                          \
1226         CALLRUNOPS(aTHX);                                               \
1227     } STMT_END
1228
1229 #define POP_MULTICALL \
1230     STMT_START {                                                        \
1231         if (! --CvDEPTH(multicall_cv))                                  \
1232             LEAVESUB(multicall_cv);                                     \
1233         POPBLOCK(cx,PL_curpm);                                          \
1234         POPSTACK;                                                       \
1235         CATCH_SET(multicall_oldcatch);                                  \
1236         LEAVE;                                                          \
1237         SPAGAIN;                                                        \
1238     } STMT_END
1239
1240 /*
1241  * Local variables:
1242  * c-indentation-style: bsd
1243  * c-basic-offset: 4
1244  * indent-tabs-mode: t
1245  * End:
1246  *
1247  * ex: set ts=8 sts=4 sw=4 noet:
1248  */