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[perl5.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://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
96  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a                                        
97  *  
98  */
99
100 #define dJMPENV         JMPENV cur_env
101
102 #define JMPENV_PUSH(v) \
103     STMT_START {                                                        \
104         DEBUG_l({                                                       \
105             int i = 0; JMPENV *p = PL_top_env;                          \
106             while (p) { i++; p = p->je_prev; }                          \
107             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
108                          i,  __FILE__, __LINE__);})                     \
109         cur_env.je_prev = PL_top_env;                                   \
110         OP_REG_TO_MEM;                                                  \
111         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
112         OP_MEM_TO_REG;                                                  \
113         PL_top_env = &cur_env;                                          \
114         cur_env.je_mustcatch = FALSE;                                   \
115         (v) = cur_env.je_ret;                                           \
116     } STMT_END
117
118 #define JMPENV_POP \
119     STMT_START {                                                        \
120         DEBUG_l({                                                       \
121             int i = -1; JMPENV *p = PL_top_env;                         \
122             while (p) { i++; p = p->je_prev; }                          \
123             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
124                          i, __FILE__, __LINE__);})                      \
125         assert(PL_top_env == &cur_env);                                 \
126         PL_top_env = cur_env.je_prev;                                   \
127     } STMT_END
128
129 #define JMPENV_JUMP(v) \
130     STMT_START {                                                \
131         DEBUG_l({                                               \
132             int i = -1; JMPENV *p = PL_top_env;                 \
133             while (p) { i++; p = p->je_prev; }                  \
134             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
135                          (int)v, i, __FILE__, __LINE__);})      \
136         OP_REG_TO_MEM;                                          \
137         if (PL_top_env->je_prev)                                \
138             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
139         if ((v) == 2)                                           \
140             PerlProc_exit(STATUS_EXIT);                         \
141         PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
142         PerlProc_exit(1);                                       \
143     } STMT_END
144
145 #define CATCH_GET               (PL_top_env->je_mustcatch)
146 #define CATCH_SET(v) \
147     STMT_START {                                                        \
148         DEBUG_l(                                                        \
149             Perl_deb(aTHX_                                              \
150                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
151                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
152                  __FILE__, __LINE__);)                                  \
153         PL_top_env->je_mustcatch = (v);                                 \
154     } STMT_END
155
156 /*
157 =head1 COP Hint Hashes
158 */
159
160 typedef struct refcounted_he COPHH;
161
162 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
163
164 /*
165 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
166
167 Look up the entry in the cop hints hash I<cophh> with the key specified by
168 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
169 the key octets are interpreted as UTF-8, otherwise they are interpreted
170 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
171 it has not been precomputed.  Returns a mortal scalar copy of the value
172 associated with the key, or C<&PL_sv_placeholder> if there is no value
173 associated with the key.
174
175 =cut
176 */
177
178 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
179     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
180
181 /*
182 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
183
184 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
185 string/length pair, and no precomputed hash.
186
187 =cut
188 */
189
190 #define cophh_fetch_pvs(cophh, key, flags) \
191     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
192
193 /*
194 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
195
196 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
197 a string/length pair.
198
199 =cut
200 */
201
202 #define cophh_fetch_pv(cophh, key, hash, flags) \
203     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
204
205 /*
206 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
207
208 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
209 string/length pair.
210
211 =cut
212 */
213
214 #define cophh_fetch_sv(cophh, key, hash, flags) \
215     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
216
217 /*
218 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
219
220 Generates and returns a standard Perl hash representing the full set of
221 key/value pairs in the cop hints hash I<cophh>.  I<flags> is currently
222 unused and must be zero.
223
224 =cut
225 */
226
227 #define cophh_2hv(cophh, flags) \
228     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
229
230 /*
231 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
232
233 Make and return a complete copy of the cop hints hash I<cophh>.
234
235 =cut
236 */
237
238 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
239
240 /*
241 =for apidoc Amx|void|cophh_free|COPHH *cophh
242
243 Discard the cop hints hash I<cophh>, freeing all resources associated
244 with it.
245
246 =cut
247 */
248
249 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
250
251 /*
252 =for apidoc Amx|COPHH *|cophh_new_empty
253
254 Generate and return a fresh cop hints hash containing no entries.
255
256 =cut
257 */
258
259 #define cophh_new_empty() ((COPHH *)NULL)
260
261 /*
262 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
263
264 Stores a value, associated with a key, in the cop hints hash I<cophh>,
265 and returns the modified hash.  The returned hash pointer is in general
266 not the same as the hash pointer that was passed in.  The input hash is
267 consumed by the function, and the pointer to it must not be subsequently
268 used.  Use L</cophh_copy> if you need both hashes.
269
270 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
271 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
272 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
273 hash of the key string, or zero if it has not been precomputed.
274
275 I<value> is the scalar value to store for this key.  I<value> is copied
276 by this function, which thus does not take ownership of any reference
277 to it, and later changes to the scalar will not be reflected in the
278 value visible in the cop hints hash.  Complex types of scalar will not
279 be stored with referential integrity, but will be coerced to strings.
280
281 =cut
282 */
283
284 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
285     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
286
287 /*
288 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
289
290 Like L</cophh_store_pvn>, but takes a literal string instead of a
291 string/length pair, and no precomputed hash.
292
293 =cut
294 */
295
296 #define cophh_store_pvs(cophh, key, value, flags) \
297     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
298
299 /*
300 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
301
302 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
303 a string/length pair.
304
305 =cut
306 */
307
308 #define cophh_store_pv(cophh, key, hash, value, flags) \
309     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
310
311 /*
312 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
313
314 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
315 string/length pair.
316
317 =cut
318 */
319
320 #define cophh_store_sv(cophh, key, hash, value, flags) \
321     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
322
323 /*
324 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
325
326 Delete a key and its associated value from the cop hints hash I<cophh>,
327 and returns the modified hash.  The returned hash pointer is in general
328 not the same as the hash pointer that was passed in.  The input hash is
329 consumed by the function, and the pointer to it must not be subsequently
330 used.  Use L</cophh_copy> if you need both hashes.
331
332 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
333 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
334 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
335 hash of the key string, or zero if it has not been precomputed.
336
337 =cut
338 */
339
340 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
341     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
342         (SV *)NULL, flags)
343
344 /*
345 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
346
347 Like L</cophh_delete_pvn>, but takes a literal string instead of a
348 string/length pair, and no precomputed hash.
349
350 =cut
351 */
352
353 #define cophh_delete_pvs(cophh, key, flags) \
354     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
355         (SV *)NULL, flags)
356
357 /*
358 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
359
360 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
361 a string/length pair.
362
363 =cut
364 */
365
366 #define cophh_delete_pv(cophh, key, hash, flags) \
367     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
368
369 /*
370 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
371
372 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
373 string/length pair.
374
375 =cut
376 */
377
378 #define cophh_delete_sv(cophh, key, hash, flags) \
379     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
380
381 #include "mydtrace.h"
382
383 struct cop {
384     BASEOP
385     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
386        an exact multiple of 8 bytes to save structure padding.  */
387     line_t      cop_line;       /* line # of this command */
388     /* label for this construct is now stored in cop_hints_hash */
389 #ifdef USE_ITHREADS
390     PADOFFSET   cop_stashoff;   /* offset into PL_stashpad, for the
391                                    package the line was compiled in */
392     char *      cop_file;       /* file name the following line # is from */
393 #else
394     HV *        cop_stash;      /* package line was compiled in */
395     GV *        cop_filegv;     /* file the following line # is from */
396 #endif
397     U32         cop_hints;      /* hints bits from pragmata */
398     U32         cop_seq;        /* parse sequence number */
399     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
400     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
401     /* compile time state of %^H.  See the comment in op.c for how this is
402        used to recreate a hash to return from caller.  */
403     COPHH *     cop_hints_hash;
404 };
405
406 #ifdef USE_ITHREADS
407 #  define CopFILE(c)            ((c)->cop_file)
408 #  define CopFILEGV(c)          (CopFILE(c) \
409                                  ? gv_fetchfile(CopFILE(c)) : NULL)
410                                  
411 #  ifdef NETWARE
412 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
413 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
414 #  else
415 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
416 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
417 #  endif
418
419 #  define CopFILESV(c)          (CopFILE(c) \
420                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
421 #  define CopFILEAV(c)          (CopFILE(c) \
422                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
423 #  define CopFILEAVx(c)         (assert_(CopFILE(c)) \
424                                    GvAV(gv_fetchfile(CopFILE(c))))
425
426 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
427 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
428                                     ? alloccopstash(hv)                 \
429                                     : 0)
430 #  ifdef NETWARE
431 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
432 #  else
433 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
434 #  endif
435 #else
436 #  define CopFILEGV(c)          ((c)->cop_filegv)
437 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
438 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
439 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
440 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
441 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
442 #  ifdef DEBUGGING
443 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
444 #  else
445 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
446 # endif
447 #  define CopFILE(c)            (CopFILEGV(c) \
448                                     ? GvNAME(CopFILEGV(c))+2 : NULL)
449 #  define CopSTASH(c)           ((c)->cop_stash)
450 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
451 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
452
453 #endif /* USE_ITHREADS */
454
455 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
456    /* cop_stash is not refcounted */
457 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
458 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
459
460 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
461 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
462
463 /*
464 =head1 COP Hint Reading
465 */
466
467 /*
468 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
469
470 Look up the hint entry in the cop I<cop> with the key specified by
471 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
472 the key octets are interpreted as UTF-8, otherwise they are interpreted
473 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
474 it has not been precomputed.  Returns a mortal scalar copy of the value
475 associated with the key, or C<&PL_sv_placeholder> if there is no value
476 associated with the key.
477
478 =cut
479 */
480
481 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
482     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
483
484 /*
485 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
486
487 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
488 string/length pair, and no precomputed hash.
489
490 =cut
491 */
492
493 #define cop_hints_fetch_pvs(cop, key, flags) \
494     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
495
496 /*
497 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
498
499 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
500 of a string/length pair.
501
502 =cut
503 */
504
505 #define cop_hints_fetch_pv(cop, key, hash, flags) \
506     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
507
508 /*
509 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
510
511 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
512 string/length pair.
513
514 =cut
515 */
516
517 #define cop_hints_fetch_sv(cop, key, hash, flags) \
518     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
519
520 /*
521 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
522
523 Generates and returns a standard Perl hash representing the full set of
524 hint entries in the cop I<cop>.  I<flags> is currently unused and must
525 be zero.
526
527 =cut
528 */
529
530 #define cop_hints_2hv(cop, flags) \
531     cophh_2hv(CopHINTHASH_get(cop), flags)
532
533 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
534 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
535 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
536 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
537
538 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
539 #define CopLINE(c)              ((c)->cop_line)
540 #define CopLINE_inc(c)          (++CopLINE(c))
541 #define CopLINE_dec(c)          (--CopLINE(c))
542 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
543
544 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
545 #define OutCopFILE(c) CopFILE(c)
546
547 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
548 #define CopHINTS_set(c, h)      STMT_START {                            \
549                                     (c)->cop_hints = (h);               \
550                                 } STMT_END
551
552 /*
553  * Here we have some enormously heavy (or at least ponderous) wizardry.
554  */
555
556 /* subroutine context */
557 struct block_sub {
558     OP *        retop;  /* op to execute on exit from sub */
559     /* Above here is the same for sub, format and eval.  */
560     CV *        cv;
561     /* Above here is the same for sub and format.  */
562     AV *        savearray;
563     AV *        argarray;
564     I32         olddepth;
565     PAD         *oldcomppad;
566 };
567
568
569 /* format context */
570 struct block_format {
571     OP *        retop;  /* op to execute on exit from sub */
572     /* Above here is the same for sub, format and eval.  */
573     CV *        cv;
574     /* Above here is the same for sub and format.  */
575     GV *        gv;
576     GV *        dfoutgv;
577 };
578
579 /* base for the next two macros. Don't use directly.
580  * Note that the refcnt of the cv is incremented twice;  The CX one is
581  * decremented by LEAVESUB, the other by LEAVE. */
582
583 #define PUSHSUB_BASE(cx)                                                \
584         ENTRY_PROBE(CvNAMED(cv)                                         \
585                         ? HEK_KEY(CvNAME_HEK(cv))                       \
586                         : GvENAME(CvGV(cv)),                            \
587                 CopFILE((const COP *)CvSTART(cv)),                      \
588                 CopLINE((const COP *)CvSTART(cv)),                      \
589                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
590                                                                         \
591         cx->blk_sub.cv = cv;                                            \
592         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
593         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
594         cx->blk_sub.retop = NULL;                                       \
595         if (!CvDEPTH(cv)) {                                             \
596             SvREFCNT_inc_simple_void_NN(cv);                            \
597             SvREFCNT_inc_simple_void_NN(cv);                            \
598             SAVEFREESV(cv);                                             \
599         }
600
601 #define PUSHSUB_GET_LVALUE_MASK(func) \
602         /* If the context is indeterminate, then only the lvalue */     \
603         /* flags that the caller also has are applicable.        */     \
604         (                                                               \
605            (PL_op->op_flags & OPf_WANT)                                 \
606                ? OPpENTERSUB_LVAL_MASK                                  \
607                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
608                    ? 0 : (U8)func(aTHX)                                 \
609         )
610
611 #define PUSHSUB(cx)                                                     \
612     {                                                                   \
613         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
614         PUSHSUB_BASE(cx)                                                \
615         cx->blk_u16 = PL_op->op_private &                               \
616                           (phlags|OPpDEREF);                            \
617     }
618
619 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
620 #define PUSHSUB_DB(cx)                                                  \
621         PUSHSUB_BASE(cx)                                                \
622         cx->blk_u16 = 0;
623
624
625 #define PUSHFORMAT(cx, retop)                                           \
626         cx->blk_format.cv = cv;                                         \
627         cx->blk_format.gv = gv;                                         \
628         cx->blk_format.retop = (retop);                                 \
629         cx->blk_format.dfoutgv = PL_defoutgv;                           \
630         if (!CvDEPTH(cv)) SvREFCNT_inc_simple_void_NN(cv);              \
631         CvDEPTH(cv)++;                                                  \
632         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
633
634 #define POP_SAVEARRAY()                                         \
635     STMT_START {                                                        \
636         SvREFCNT_dec(GvAV(PL_defgv));                                   \
637         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
638     } STMT_END
639
640 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
641  * leave any (a fast av_clear(ary), basically) */
642 #define CLEAR_ARGARRAY(ary) \
643     STMT_START {                                                        \
644         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
645         AvARRAY(ary) = AvALLOC(ary);                                    \
646         AvFILLp(ary) = -1;                                              \
647     } STMT_END
648
649 #define POPSUB(cx,sv)                                                   \
650     STMT_START {                                                        \
651         const I32 olddepth = cx->blk_sub.olddepth;                      \
652         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
653                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
654                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
655                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
656                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
657                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
658                                                                         \
659         if (CxHASARGS(cx)) {                                            \
660             POP_SAVEARRAY();                                            \
661             /* abandon @_ if it got reified */                          \
662             if (AvREAL(cx->blk_sub.argarray)) {                         \
663                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
664                 SvREFCNT_dec_NN(cx->blk_sub.argarray);                  \
665                 cx->blk_sub.argarray = newAV();                         \
666                 av_extend(cx->blk_sub.argarray, fill);                  \
667                 AvREIFY_only(cx->blk_sub.argarray);                     \
668                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
669             }                                                           \
670             else {                                                      \
671                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
672             }                                                           \
673         }                                                               \
674         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
675         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
676         if (sv && (CvDEPTH((const CV*)sv) = olddepth))                  \
677             sv = NULL;                                          \
678     } STMT_END
679
680 #define LEAVESUB(sv)                                                    \
681     STMT_START {                                                        \
682         SvREFCNT_dec(sv);                                               \
683     } STMT_END
684
685 #define POPFORMAT(cx)                                                   \
686     STMT_START {                                                        \
687         CV * const cv = cx->blk_format.cv;                              \
688         GV * const dfuot = cx->blk_format.dfoutgv;                      \
689         setdefout(dfuot);                                               \
690         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
691         if (!--CvDEPTH(cv))                                             \
692             SvREFCNT_dec_NN(cx->blk_format.cv);                         \
693         SvREFCNT_dec_NN(dfuot);                                         \
694     } STMT_END
695
696 /* eval context */
697 struct block_eval {
698     OP *        retop;  /* op to execute on exit from eval */
699     /* Above here is the same for sub, format and eval.  */
700     SV *        old_namesv;
701     OP *        old_eval_root;
702     SV *        cur_text;
703     CV *        cv;
704     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
705 };
706
707 /* If we ever need more than 512 op types, change the shift from 7.
708    blku_gimme is actually also only 2 bits, so could be merged with something.
709 */
710
711 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
712 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
713
714 #define PUSHEVAL(cx,n)                                                  \
715     STMT_START {                                                        \
716         assert(!(PL_in_eval & ~0x7F));                                  \
717         assert(!(PL_op->op_type & ~0x1FF));                             \
718         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
719         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
720         cx->blk_eval.old_eval_root = PL_eval_root;                      \
721         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
722         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
723         cx->blk_eval.retop = NULL;                                      \
724         cx->blk_eval.cur_top_env = PL_top_env;                          \
725     } STMT_END
726
727 #define POPEVAL(cx)                                                     \
728     STMT_START {                                                        \
729         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
730         optype = CxOLD_OP_TYPE(cx);                                     \
731         PL_eval_root = cx->blk_eval.old_eval_root;                      \
732         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
733             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
734         if (cx->blk_eval.old_namesv)                                    \
735             sv_2mortal(cx->blk_eval.old_namesv);                        \
736     } STMT_END
737
738 /* loop context */
739 struct block_loop {
740     I32         resetsp;
741     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
742     union {     /* different ways of locating the iteration variable */
743         SV      **svp;
744         GV      *gv;
745         PAD     *oldcomppad; /* only used in ITHREADS */
746     } itervar_u;
747     union {
748         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
749             AV * ary; /* use the stack if this is NULL */
750             IV ix;
751         } ary;
752         struct { /* valid if type is LOOP_LAZYIV */
753             IV cur;
754             IV end;
755         } lazyiv;
756         struct { /* valid if type if LOOP_LAZYSV */
757             SV * cur;
758             SV * end; /* maxiumum value (or minimum in reverse) */
759         } lazysv;
760     } state_u;
761 };
762
763 #ifdef USE_ITHREADS
764 #  define CxITERVAR_PADSV(c) \
765         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
766 #else
767 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
768 #endif
769
770 #define CxITERVAR(c)                                                    \
771         ((c)->blk_loop.itervar_u.oldcomppad                             \
772          ? (CxPADLOOP(c)                                                \
773             ? CxITERVAR_PADSV(c)                                        \
774             : &GvSV((c)->blk_loop.itervar_u.gv))                        \
775          : (SV**)NULL)
776
777 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
778 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
779 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
780 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
781 #define CxLVAL(c)       (0 + (c)->blk_u16)
782
783 #define PUSHLOOP_PLAIN(cx, s)                                           \
784         cx->blk_loop.resetsp = s - PL_stack_base;                       \
785         cx->blk_loop.my_op = cLOOP;                                     \
786         cx->blk_loop.state_u.ary.ary = NULL;                            \
787         cx->blk_loop.state_u.ary.ix = 0;                                \
788         cx->blk_loop.itervar_u.svp = NULL;
789
790 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
791         cx->blk_loop.resetsp = s - PL_stack_base;                       \
792         cx->blk_loop.my_op = cLOOP;                                     \
793         cx->blk_loop.state_u.ary.ary = NULL;                            \
794         cx->blk_loop.state_u.ary.ix = 0;                                \
795         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
796
797 #define POPLOOP(cx)                                                     \
798         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
799             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
800             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
801         }                                                               \
802         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
803             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
804
805 /* given/when context */
806 struct block_givwhen {
807         OP *leave_op;
808 };
809
810 #define PUSHGIVEN(cx)                                                   \
811         cx->blk_givwhen.leave_op = cLOGOP->op_other;
812
813 #define PUSHWHEN PUSHGIVEN
814
815 /* context common to subroutines, evals and loops */
816 struct block {
817     U8          blku_type;      /* what kind of context this is */
818     U8          blku_gimme;     /* is this block running in list context? */
819     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
820     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
821     COP *       blku_oldcop;    /* old curcop pointer */
822     I32         blku_oldmarksp; /* mark stack index */
823     I32         blku_oldscopesp;        /* scope stack index */
824     PMOP *      blku_oldpm;     /* values of pattern match vars */
825
826     union {
827         struct block_sub        blku_sub;
828         struct block_format     blku_format;
829         struct block_eval       blku_eval;
830         struct block_loop       blku_loop;
831         struct block_givwhen    blku_givwhen;
832     } blk_u;
833 };
834 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
835 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
836 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
837 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
838 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
839 #define blk_gimme       cx_u.cx_blk.blku_gimme
840 #define blk_u16         cx_u.cx_blk.blku_u16
841 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
842 #define blk_format      cx_u.cx_blk.blk_u.blku_format
843 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
844 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
845 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
846
847 #define DEBUG_CX(action)                                                \
848     DEBUG_l(                                                            \
849         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
850                     (long)cxstack_ix,                                   \
851                     action,                                             \
852                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
853                     (long)PL_scopestack_ix,                             \
854                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
855                     __FILE__, __LINE__));
856
857 /* Enter a block. */
858 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
859         cx->cx_type             = t,                                    \
860         cx->blk_oldsp           = sp - PL_stack_base,                   \
861         cx->blk_oldcop          = PL_curcop,                            \
862         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
863         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
864         cx->blk_oldpm           = PL_curpm,                             \
865         cx->blk_gimme           = (U8)gimme;                            \
866         DEBUG_CX("PUSH");
867
868 /* Exit a block (RETURN and LAST). */
869 #define POPBLOCK(cx,pm)                                                 \
870         DEBUG_CX("POP");                                                \
871         cx = &cxstack[cxstack_ix--],                                    \
872         newsp            = PL_stack_base + cx->blk_oldsp,               \
873         PL_curcop        = cx->blk_oldcop,                              \
874         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
875         PL_scopestack_ix = cx->blk_oldscopesp,                          \
876         pm               = cx->blk_oldpm,                               \
877         gimme            = cx->blk_gimme;
878
879 /* Continue a block elsewhere (NEXT and REDO). */
880 #define TOPBLOCK(cx)                                                    \
881         DEBUG_CX("TOP");                                                \
882         cx  = &cxstack[cxstack_ix],                                     \
883         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
884         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
885         PL_scopestack_ix = cx->blk_oldscopesp,                          \
886         PL_curpm         = cx->blk_oldpm;
887
888 /* substitution context */
889 struct subst {
890     U8          sbu_type;       /* what kind of context this is */
891     U8          sbu_rflags;
892     U16         sbu_rxtainted;  /* matches struct block */
893     I32         sbu_iters;
894     I32         sbu_maxiters;
895     I32         sbu_oldsave;
896     char *      sbu_orig;
897     SV *        sbu_dstr;
898     SV *        sbu_targ;
899     char *      sbu_s;
900     char *      sbu_m;
901     char *      sbu_strend;
902     void *      sbu_rxres;
903     REGEXP *    sbu_rx;
904 };
905 #define sb_iters        cx_u.cx_subst.sbu_iters
906 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
907 #define sb_rflags       cx_u.cx_subst.sbu_rflags
908 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
909 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
910 #define sb_orig         cx_u.cx_subst.sbu_orig
911 #define sb_dstr         cx_u.cx_subst.sbu_dstr
912 #define sb_targ         cx_u.cx_subst.sbu_targ
913 #define sb_s            cx_u.cx_subst.sbu_s
914 #define sb_m            cx_u.cx_subst.sbu_m
915 #define sb_strend       cx_u.cx_subst.sbu_strend
916 #define sb_rxres        cx_u.cx_subst.sbu_rxres
917 #define sb_rx           cx_u.cx_subst.sbu_rx
918
919 #ifdef PERL_CORE
920 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
921         cx->sb_iters            = iters,                                \
922         cx->sb_maxiters         = maxiters,                             \
923         cx->sb_rflags           = r_flags,                              \
924         cx->sb_oldsave          = oldsave,                              \
925         cx->sb_rxtainted        = rxtainted,                            \
926         cx->sb_orig             = orig,                                 \
927         cx->sb_dstr             = dstr,                                 \
928         cx->sb_targ             = targ,                                 \
929         cx->sb_s                = s,                                    \
930         cx->sb_m                = m,                                    \
931         cx->sb_strend           = strend,                               \
932         cx->sb_rxres            = NULL,                                 \
933         cx->sb_rx               = rx,                                   \
934         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
935         rxres_save(&cx->sb_rxres, rx);                                  \
936         (void)ReREFCNT_inc(rx)
937
938 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
939         rxres_free(&cx->sb_rxres);                                      \
940         ReREFCNT_dec(cx->sb_rx)
941 #endif
942
943 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
944
945 struct context {
946     union {
947         struct block    cx_blk;
948         struct subst    cx_subst;
949     } cx_u;
950 };
951 #define cx_type cx_u.cx_subst.sbu_type
952
953 /* If you re-order these, there is also an array of uppercase names in perl.h
954    and a static array of context names in pp_ctl.c  */
955 #define CXTYPEMASK      0xf
956 #define CXt_NULL        0
957 #define CXt_WHEN        1
958 #define CXt_BLOCK       2
959 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
960    jump table in pp_ctl.c
961    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
962 */
963 #define CXt_GIVEN       3
964 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
965 #define CXt_LOOP_FOR    4
966 #define CXt_LOOP_PLAIN  5
967 #define CXt_LOOP_LAZYSV 6
968 #define CXt_LOOP_LAZYIV 7
969 #define CXt_SUB         8
970 #define CXt_FORMAT      9
971 #define CXt_EVAL       10
972 #define CXt_SUBST      11
973 /* SUBST doesn't feature in all switch statements.  */
974
975 /* private flags for CXt_SUB and CXt_NULL
976    However, this is checked in many places which do not check the type, so
977    this bit needs to be kept clear for most everything else. For reasons I
978    haven't investigated, it can coexist with CXp_FOR_DEF */
979 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
980                                    tear down context on exit). */ 
981
982 /* private flags for CXt_SUB and CXt_FORMAT */
983 #define CXp_HASARGS     0x20
984 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
985 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
986
987 /* private flags for CXt_EVAL */
988 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
989 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
990
991 /* private flags for CXt_LOOP */
992 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
993 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
994
995 /* private flags for CXt_SUBST */
996 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
997
998 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
999 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1000 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
1001                          == CXp_MULTICALL)
1002 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1003                          == (CXt_EVAL|CXp_REAL))
1004 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1005                          == (CXt_EVAL|CXp_TRYBLOCK))
1006 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1007 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1008                          && ((c)->cx_type & CXp_FOR_DEF))
1009
1010 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1011
1012 /* 
1013 =head1 "Gimme" Values
1014 */
1015
1016 /*
1017 =for apidoc AmU||G_SCALAR
1018 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
1019 L<perlcall>.
1020
1021 =for apidoc AmU||G_ARRAY
1022 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
1023 L<perlcall>.
1024
1025 =for apidoc AmU||G_VOID
1026 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
1027
1028 =for apidoc AmU||G_DISCARD
1029 Indicates that arguments returned from a callback should be discarded.  See
1030 L<perlcall>.
1031
1032 =for apidoc AmU||G_EVAL
1033
1034 Used to force a Perl C<eval> wrapper around a callback.  See
1035 L<perlcall>.
1036
1037 =for apidoc AmU||G_NOARGS
1038
1039 Indicates that no arguments are being sent to a callback.  See
1040 L<perlcall>.
1041
1042 =cut
1043 */
1044
1045 #define G_SCALAR        2
1046 #define G_ARRAY         3
1047 #define G_VOID          1
1048 #define G_WANT          3
1049
1050 /* extra flags for Perl_call_* routines */
1051 #define G_DISCARD       4       /* Call FREETMPS.
1052                                    Don't change this without consulting the
1053                                    hash actions codes defined in hv.h */
1054 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1055 #define G_NOARGS       16       /* Don't construct a @_ array. */
1056 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1057 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1058 #define G_METHOD      128       /* Calling method. */
1059 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1060                                    fold_constants. */
1061 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1062                                    A special case for UNSHIFT in
1063                                    Perl_magic_methcall().  */
1064 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1065                                     Perl_magic_methcall().  */
1066 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1067 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1068
1069 /* flag bits for PL_in_eval */
1070 #define EVAL_NULL       0       /* not in an eval */
1071 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1072 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1073 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1074 #define EVAL_INREQUIRE  8       /* The code is being required. */
1075 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
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             Perl_croak_popstack();                                      \
1155         }                                                               \
1156         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1157         /* don't free prev here, free them all at the END{} */          \
1158         PL_curstackinfo = prev;                                         \
1159     } STMT_END
1160
1161 #define POPSTACK_TO(s) \
1162     STMT_START {                                                        \
1163         while (PL_curstack != s) {                                      \
1164             dounwind(-1);                                               \
1165             POPSTACK;                                                   \
1166         }                                                               \
1167     } STMT_END
1168
1169 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1170 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1171
1172 /*
1173 =head1 Multicall Functions
1174
1175 =for apidoc Ams||dMULTICALL
1176 Declare local variables for a multicall. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1177
1178 =for apidoc Ams||PUSH_MULTICALL
1179 Opening bracket for a lightweight callback.
1180 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1181
1182 =for apidoc Ams||MULTICALL
1183 Make a lightweight callback. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1184
1185 =for apidoc Ams||POP_MULTICALL
1186 Closing bracket for a lightweight callback.
1187 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1188
1189 =cut
1190 */
1191
1192 #define dMULTICALL \
1193     SV **newsp;                 /* set by POPBLOCK */                   \
1194     PERL_CONTEXT *cx;                                                   \
1195     CV *multicall_cv;                                                   \
1196     OP *multicall_cop;                                                  \
1197     bool multicall_oldcatch;                                            \
1198     U8 hasargs = 0              /* used by PUSHSUB */
1199
1200 #define PUSH_MULTICALL(the_cv) \
1201     PUSH_MULTICALL_FLAGS(the_cv, 0)
1202
1203 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1204  * for the CX stack entry (this isn't part of the public API) */
1205
1206 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1207     STMT_START {                                                        \
1208         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1209         CV * const cv = _nOnclAshIngNamE_;                              \
1210         PADLIST * const padlist = CvPADLIST(cv);                        \
1211         ENTER;                                                          \
1212         multicall_oldcatch = CATCH_GET;                                 \
1213         SAVETMPS; SAVEVPTR(PL_op);                                      \
1214         CATCH_SET(TRUE);                                                \
1215         PUSHSTACKi(PERLSI_SORT);                                        \
1216         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1217         PUSHSUB(cx);                                                    \
1218         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1219             CvDEPTH(cv)++;                                              \
1220         if (CvDEPTH(cv) >= 2) {                                         \
1221             PERL_STACK_OVERFLOW_CHECK();                                \
1222             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1223         }                                                               \
1224         SAVECOMPPAD();                                                  \
1225         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1226         multicall_cv = cv;                                              \
1227         multicall_cop = CvSTART(cv);                                    \
1228     } STMT_END
1229
1230 #define MULTICALL \
1231     STMT_START {                                                        \
1232         PL_op = multicall_cop;                                          \
1233         CALLRUNOPS(aTHX);                                               \
1234     } STMT_END
1235
1236 #define POP_MULTICALL \
1237     STMT_START {                                                        \
1238         cx = &cxstack[cxstack_ix];                                      \
1239         if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {      \
1240                 LEAVESUB(multicall_cv);                                 \
1241         }                                                               \
1242         POPBLOCK(cx,PL_curpm);                                          \
1243         POPSTACK;                                                       \
1244         CATCH_SET(multicall_oldcatch);                                  \
1245         LEAVE;                                                          \
1246         SPAGAIN;                                                        \
1247     } STMT_END
1248
1249 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1250  * (this isn't part of the public API) */
1251
1252 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1253     STMT_START {                                                        \
1254         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1255         CV * const cv = _nOnclAshIngNamE_;                              \
1256         PADLIST * const padlist = CvPADLIST(cv);                        \
1257         cx = &cxstack[cxstack_ix];                                      \
1258         assert(cx->cx_type & CXp_MULTICALL);                            \
1259         if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {      \
1260                 LEAVESUB(multicall_cv);                                 \
1261         }                                                               \
1262         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1263         PUSHSUB(cx);                                                    \
1264         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1265             CvDEPTH(cv)++;                                              \
1266         if (CvDEPTH(cv) >= 2) {                                         \
1267             PERL_STACK_OVERFLOW_CHECK();                                \
1268             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1269         }                                                               \
1270         SAVECOMPPAD();                                                  \
1271         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1272         multicall_cv = cv;                                              \
1273         multicall_cop = CvSTART(cv);                                    \
1274     } STMT_END
1275 /*
1276  * Local variables:
1277  * c-indentation-style: bsd
1278  * c-basic-offset: 4
1279  * indent-tabs-mode: nil
1280  * End:
1281  *
1282  * ex: set ts=8 sts=4 sw=4 et:
1283  */