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SvREFCNT_inc(cv) recursive subs
[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 statement separators.
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;         /* uninit if je_prev is NULL */
35     int                 je_ret;         /* last exception thrown */
36     bool                je_mustcatch;   /* need to call longjmp()? */
37     U16                 je_old_delaymagic; /* saved PL_delaymagic */
38 };
39
40 typedef struct jmpenv JMPENV;
41
42 /*
43  * How to build the first jmpenv.
44  *
45  * top_env needs to be non-zero. It points to an area
46  * in which longjmp() stuff is stored, as C callstack
47  * info there at least is thread specific this has to
48  * be per-thread. Otherwise a 'die' in a thread gives
49  * that thread the C stack of last thread to do an eval {}!
50  */
51
52 #define JMPENV_BOOTSTRAP \
53     STMT_START {                                \
54         PERL_POISON_EXPR(PoisonNew(&PL_start_env, 1, JMPENV));\
55         PL_top_env = &PL_start_env;             \
56         PL_start_env.je_prev = NULL;            \
57         PL_start_env.je_ret = -1;               \
58         PL_start_env.je_mustcatch = TRUE;       \
59         PL_start_env.je_old_delaymagic = 0;     \
60     } STMT_END
61
62 /*
63  *   PERL_FLEXIBLE_EXCEPTIONS
64  * 
65  * All the flexible exceptions code has been removed.
66  * See the following threads for details:
67  *
68  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
69  * 
70  * Joshua's original patches (which weren't applied) and discussion:
71  * 
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
74  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
75  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
78  * 
79  * Chip's reworked patch and discussion:
80  * 
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
82  * 
83  * The flaw in these patches (which went unnoticed at the time) was
84  * that they moved some code that could potentially die() out of the
85  * region protected by the setjmp()s.  This caused exceptions within
86  * END blocks and such to not be handled by the correct setjmp().
87  * 
88  * The original patches that introduces flexible exceptions were:
89  *
90  * http://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
91  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a                                        
92  *  
93  */
94
95 #define dJMPENV         JMPENV cur_env
96
97 #define JMPENV_PUSH(v) \
98     STMT_START {                                                        \
99         DEBUG_l({                                                       \
100             int i = 0; JMPENV *p = PL_top_env;                          \
101             while (p) { i++; p = p->je_prev; }                          \
102             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
103                          i,  __FILE__, __LINE__);})                     \
104         cur_env.je_prev = PL_top_env;                                   \
105         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
106         PL_top_env = &cur_env;                                          \
107         cur_env.je_mustcatch = FALSE;                                   \
108         cur_env.je_old_delaymagic = PL_delaymagic;                      \
109         (v) = cur_env.je_ret;                                           \
110     } STMT_END
111
112 #define JMPENV_POP \
113     STMT_START {                                                        \
114         DEBUG_l({                                                       \
115             int i = -1; JMPENV *p = PL_top_env;                         \
116             while (p) { i++; p = p->je_prev; }                          \
117             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
118                          i, __FILE__, __LINE__);})                      \
119         assert(PL_top_env == &cur_env);                                 \
120         PL_delaymagic = cur_env.je_old_delaymagic;                      \
121         PL_top_env = cur_env.je_prev;                                   \
122     } STMT_END
123
124 #define JMPENV_JUMP(v) \
125     STMT_START {                                                \
126         DEBUG_l({                                               \
127             int i = -1; JMPENV *p = PL_top_env;                 \
128             while (p) { i++; p = p->je_prev; }                  \
129             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
130                          (int)v, i, __FILE__, __LINE__);})      \
131         if (PL_top_env->je_prev)                                \
132             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
133         if ((v) == 2)                                           \
134             PerlProc_exit(STATUS_EXIT);                         \
135         PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
136         PerlProc_exit(1);                                       \
137     } STMT_END
138
139 #define CATCH_GET               (PL_top_env->je_mustcatch)
140 #define CATCH_SET(v) \
141     STMT_START {                                                        \
142         DEBUG_l(                                                        \
143             Perl_deb(aTHX_                                              \
144                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
145                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
146                  __FILE__, __LINE__);)                                  \
147         PL_top_env->je_mustcatch = (v);                                 \
148     } STMT_END
149
150 /*
151 =head1 COP Hint Hashes
152 */
153
154 typedef struct refcounted_he COPHH;
155
156 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
157
158 /*
159 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
160
161 Look up the entry in the cop hints hash C<cophh> with the key specified by
162 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
163 the key octets are interpreted as UTF-8, otherwise they are interpreted
164 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
165 it has not been precomputed.  Returns a mortal scalar copy of the value
166 associated with the key, or C<&PL_sv_placeholder> if there is no value
167 associated with the key.
168
169 =cut
170 */
171
172 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
173     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
174
175 /*
176 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
177
178 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
179 string/length pair, and no precomputed hash.
180
181 =cut
182 */
183
184 #define cophh_fetch_pvs(cophh, key, flags) \
185     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
186
187 /*
188 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
189
190 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
191 a string/length pair.
192
193 =cut
194 */
195
196 #define cophh_fetch_pv(cophh, key, hash, flags) \
197     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
198
199 /*
200 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
201
202 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
203 string/length pair.
204
205 =cut
206 */
207
208 #define cophh_fetch_sv(cophh, key, hash, flags) \
209     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
210
211 /*
212 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
213
214 Generates and returns a standard Perl hash representing the full set of
215 key/value pairs in the cop hints hash C<cophh>.  C<flags> is currently
216 unused and must be zero.
217
218 =cut
219 */
220
221 #define cophh_2hv(cophh, flags) \
222     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
223
224 /*
225 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
226
227 Make and return a complete copy of the cop hints hash C<cophh>.
228
229 =cut
230 */
231
232 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
233
234 /*
235 =for apidoc Amx|void|cophh_free|COPHH *cophh
236
237 Discard the cop hints hash C<cophh>, freeing all resources associated
238 with it.
239
240 =cut
241 */
242
243 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
244
245 /*
246 =for apidoc Amx|COPHH *|cophh_new_empty
247
248 Generate and return a fresh cop hints hash containing no entries.
249
250 =cut
251 */
252
253 #define cophh_new_empty() ((COPHH *)NULL)
254
255 /*
256 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
257
258 Stores a value, associated with a key, in the cop hints hash C<cophh>,
259 and returns the modified hash.  The returned hash pointer is in general
260 not the same as the hash pointer that was passed in.  The input hash is
261 consumed by the function, and the pointer to it must not be subsequently
262 used.  Use L</cophh_copy> if you need both hashes.
263
264 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
265 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
266 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
267 hash of the key string, or zero if it has not been precomputed.
268
269 C<value> is the scalar value to store for this key.  C<value> is copied
270 by this function, which thus does not take ownership of any reference
271 to it, and later changes to the scalar will not be reflected in the
272 value visible in the cop hints hash.  Complex types of scalar will not
273 be stored with referential integrity, but will be coerced to strings.
274
275 =cut
276 */
277
278 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
279     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
280
281 /*
282 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
283
284 Like L</cophh_store_pvn>, but takes a literal string instead of a
285 string/length pair, and no precomputed hash.
286
287 =cut
288 */
289
290 #define cophh_store_pvs(cophh, key, value, flags) \
291     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
292
293 /*
294 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
295
296 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
297 a string/length pair.
298
299 =cut
300 */
301
302 #define cophh_store_pv(cophh, key, hash, value, flags) \
303     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
304
305 /*
306 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
307
308 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
309 string/length pair.
310
311 =cut
312 */
313
314 #define cophh_store_sv(cophh, key, hash, value, flags) \
315     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
316
317 /*
318 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
319
320 Delete a key and its associated value from the cop hints hash C<cophh>,
321 and returns the modified hash.  The returned hash pointer is in general
322 not the same as the hash pointer that was passed in.  The input hash is
323 consumed by the function, and the pointer to it must not be subsequently
324 used.  Use L</cophh_copy> if you need both hashes.
325
326 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
327 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
328 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
329 hash of the key string, or zero if it has not been precomputed.
330
331 =cut
332 */
333
334 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
335     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
336         (SV *)NULL, flags)
337
338 /*
339 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
340
341 Like L</cophh_delete_pvn>, but takes a literal string instead of a
342 string/length pair, and no precomputed hash.
343
344 =cut
345 */
346
347 #define cophh_delete_pvs(cophh, key, flags) \
348     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
349         (SV *)NULL, flags)
350
351 /*
352 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
353
354 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
355 a string/length pair.
356
357 =cut
358 */
359
360 #define cophh_delete_pv(cophh, key, hash, flags) \
361     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
362
363 /*
364 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
365
366 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
367 string/length pair.
368
369 =cut
370 */
371
372 #define cophh_delete_sv(cophh, key, hash, flags) \
373     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
374
375 #include "mydtrace.h"
376
377 struct cop {
378     BASEOP
379     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
380        an exact multiple of 8 bytes to save structure padding.  */
381     line_t      cop_line;       /* line # of this command */
382     /* label for this construct is now stored in cop_hints_hash */
383 #ifdef USE_ITHREADS
384     PADOFFSET   cop_stashoff;   /* offset into PL_stashpad, for the
385                                    package the line was compiled in */
386     char *      cop_file;       /* file name the following line # is from */
387 #else
388     HV *        cop_stash;      /* package line was compiled in */
389     GV *        cop_filegv;     /* file the following line # is from */
390 #endif
391     U32         cop_hints;      /* hints bits from pragmata */
392     U32         cop_seq;        /* parse sequence number */
393     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
394     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
395     /* compile time state of %^H.  See the comment in op.c for how this is
396        used to recreate a hash to return from caller.  */
397     COPHH *     cop_hints_hash;
398 };
399
400 #ifdef USE_ITHREADS
401 #  define CopFILE(c)            ((c)->cop_file)
402 #  define CopFILEGV(c)          (CopFILE(c) \
403                                  ? gv_fetchfile(CopFILE(c)) : NULL)
404                                  
405 #  ifdef NETWARE
406 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
407 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepvn((pv),(l)))
408 #  else
409 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
410 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
411 #  endif
412
413 #  define CopFILESV(c)          (CopFILE(c) \
414                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
415 #  define CopFILEAV(c)          (CopFILE(c) \
416                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
417 #  define CopFILEAVx(c)         (assert_(CopFILE(c)) \
418                                    GvAV(gv_fetchfile(CopFILE(c))))
419
420 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
421 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
422                                     ? alloccopstash(hv)                 \
423                                     : 0)
424 #  ifdef NETWARE
425 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
426 #  else
427 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
428 #  endif
429 #else
430 #  define CopFILEGV(c)          ((c)->cop_filegv)
431 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
432 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
433 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
434 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
435 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
436 #  ifdef DEBUGGING
437 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
438 #  else
439 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
440 # endif
441 #  define CopFILE(c)            (CopFILEGV(c) \
442                                     ? GvNAME(CopFILEGV(c))+2 : NULL)
443 #  define CopSTASH(c)           ((c)->cop_stash)
444 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
445 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
446
447 #endif /* USE_ITHREADS */
448
449 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
450    /* cop_stash is not refcounted */
451 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
452 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
453
454 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
455 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
456
457 /*
458 =head1 COP Hint Reading
459 */
460
461 /*
462 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
463
464 Look up the hint entry in the cop C<cop> with the key specified by
465 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
466 the key octets are interpreted as UTF-8, otherwise they are interpreted
467 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
468 it has not been precomputed.  Returns a mortal scalar copy of the value
469 associated with the key, or C<&PL_sv_placeholder> if there is no value
470 associated with the key.
471
472 =cut
473 */
474
475 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
476     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
477
478 /*
479 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
480
481 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
482 string/length pair, and no precomputed hash.
483
484 =cut
485 */
486
487 #define cop_hints_fetch_pvs(cop, key, flags) \
488     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
489
490 /*
491 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
492
493 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
494 of a string/length pair.
495
496 =cut
497 */
498
499 #define cop_hints_fetch_pv(cop, key, hash, flags) \
500     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
501
502 /*
503 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
504
505 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
506 string/length pair.
507
508 =cut
509 */
510
511 #define cop_hints_fetch_sv(cop, key, hash, flags) \
512     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
513
514 /*
515 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
516
517 Generates and returns a standard Perl hash representing the full set of
518 hint entries in the cop C<cop>.  C<flags> is currently unused and must
519 be zero.
520
521 =cut
522 */
523
524 #define cop_hints_2hv(cop, flags) \
525     cophh_2hv(CopHINTHASH_get(cop), flags)
526
527 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
528 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
529 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
530 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
531
532 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
533 #define CopLINE(c)              ((c)->cop_line)
534 #define CopLINE_inc(c)          (++CopLINE(c))
535 #define CopLINE_dec(c)          (--CopLINE(c))
536 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
537
538 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
539 #define OutCopFILE(c) CopFILE(c)
540
541 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
542 #define CopHINTS_set(c, h)      STMT_START {                            \
543                                     (c)->cop_hints = (h);               \
544                                 } STMT_END
545
546 /*
547  * Here we have some enormously heavy (or at least ponderous) wizardry.
548  */
549
550 /* subroutine context */
551 struct block_sub {
552     OP *        retop;  /* op to execute on exit from sub */
553     /* Above here is the same for sub, format and eval.  */
554     CV *        cv;
555     /* Above here is the same for sub and format.  */
556     AV *        savearray;
557     AV *        argarray;
558     I32         olddepth;
559     PAD         *oldcomppad;
560 };
561
562
563 /* format context */
564 struct block_format {
565     OP *        retop;  /* op to execute on exit from sub */
566     /* Above here is the same for sub, format and eval.  */
567     CV *        cv;
568     /* Above here is the same for sub and format.  */
569     GV *        gv;
570     GV *        dfoutgv;
571 };
572
573 /* base for the next two macros. Don't use directly.
574  * The context frame holds a reference to the CV so that it can't be
575  * freed while we're executing it */
576
577 #define PUSHSUB_BASE(cx)                                                \
578         ENTRY_PROBE(CvNAMED(cv)                                         \
579                         ? HEK_KEY(CvNAME_HEK(cv))                       \
580                         : GvENAME(CvGV(cv)),                            \
581                 CopFILE((const COP *)CvSTART(cv)),                      \
582                 CopLINE((const COP *)CvSTART(cv)),                      \
583                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
584                                                                         \
585         cx->blk_sub.cv = cv;                                            \
586         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
587         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
588         cx->blk_sub.retop = NULL;                                       \
589         SvREFCNT_inc_simple_void_NN(cv);
590
591 #define PUSHSUB_GET_LVALUE_MASK(func) \
592         /* If the context is indeterminate, then only the lvalue */     \
593         /* flags that the caller also has are applicable.        */     \
594         (                                                               \
595            (PL_op->op_flags & OPf_WANT)                                 \
596                ? OPpENTERSUB_LVAL_MASK                                  \
597                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
598                    ? 0 : (U8)func(aTHX)                                 \
599         )
600
601 #define PUSHSUB(cx)                                                     \
602     {                                                                   \
603         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
604         PUSHSUB_BASE(cx)                                                \
605         cx->blk_u16 = PL_op->op_private &                               \
606                           (phlags|OPpDEREF);                            \
607     }
608
609 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
610 #define PUSHSUB_DB(cx)                                                  \
611         PUSHSUB_BASE(cx)                                                \
612         cx->blk_u16 = 0;
613
614
615 #define PUSHFORMAT(cx, retop)                                           \
616         cx->blk_format.cv = cv;                                         \
617         cx->blk_format.gv = gv;                                         \
618         cx->blk_format.retop = (retop);                                 \
619         cx->blk_format.dfoutgv = PL_defoutgv;                           \
620         cx->blk_u16 = 0;                                                \
621         SvREFCNT_inc_simple_void_NN(cv);                                \
622         CvDEPTH(cv)++;                                                  \
623         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
624
625 #define POP_SAVEARRAY()                                         \
626     STMT_START {                                                        \
627         SvREFCNT_dec(GvAV(PL_defgv));                                   \
628         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
629     } STMT_END
630
631 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
632  * leave any (a fast av_clear(ary), basically) */
633 #define CLEAR_ARGARRAY(ary) \
634     STMT_START {                                                        \
635         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
636         AvARRAY(ary) = AvALLOC(ary);                                    \
637         AvFILLp(ary) = -1;                                              \
638     } STMT_END
639
640 #define POPSUB(cx,sv)                                                   \
641     STMT_START {                                                        \
642         const I32 olddepth = cx->blk_sub.olddepth;                      \
643         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
644         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
645         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
646                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
647                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
648                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
649                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
650                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
651                                                                         \
652         if (CxHASARGS(cx)) {                                            \
653             POP_SAVEARRAY();                                            \
654             /* abandon @_ if it got reified */                          \
655             if (AvREAL(cx->blk_sub.argarray)) {                         \
656                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
657                 SvREFCNT_dec_NN(cx->blk_sub.argarray);                  \
658                 cx->blk_sub.argarray = newAV();                         \
659                 av_extend(cx->blk_sub.argarray, fill);                  \
660                 AvREIFY_only(cx->blk_sub.argarray);                     \
661                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
662             }                                                           \
663             else {                                                      \
664                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
665             }                                                           \
666         }                                                               \
667         }                                                               \
668         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
669         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
670         CvDEPTH((const CV*)sv) = olddepth;                              \
671     } STMT_END
672
673 #define LEAVESUB(sv)                                                    \
674     STMT_START {                                                        \
675         SvREFCNT_dec(sv);                                               \
676     } STMT_END
677
678 #define POPFORMAT(cx)                                                   \
679     STMT_START {                                                        \
680         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
681         CV * const cv = cx->blk_format.cv;                              \
682         GV * const dfuot = cx->blk_format.dfoutgv;                      \
683         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
684         setdefout(dfuot);                                               \
685         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
686         --CvDEPTH(cv);                                                  \
687         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
688         SvREFCNT_dec_NN(dfuot);                                         \
689         }                                                               \
690     } STMT_END
691
692 /* eval context */
693 struct block_eval {
694     OP *        retop;  /* op to execute on exit from eval */
695     /* Above here is the same for sub, format and eval.  */
696     SV *        old_namesv;
697     OP *        old_eval_root;
698     SV *        cur_text;
699     CV *        cv;
700     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
701 };
702
703 /* If we ever need more than 512 op types, change the shift from 7.
704    blku_gimme is actually also only 2 bits, so could be merged with something.
705 */
706
707 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
708 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
709
710 #define PUSHEVAL(cx,n)                                                  \
711     STMT_START {                                                        \
712         assert(!(PL_in_eval & ~0x7F));                                  \
713         assert(!(PL_op->op_type & ~0x1FF));                             \
714         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
715         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
716         cx->blk_eval.old_eval_root = PL_eval_root;                      \
717         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
718         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
719         cx->blk_eval.retop = NULL;                                      \
720         cx->blk_eval.cur_top_env = PL_top_env;                          \
721     } STMT_END
722
723 #define POPEVAL(cx)                                                     \
724     STMT_START {                                                        \
725         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
726         optype = CxOLD_OP_TYPE(cx);                                     \
727         PL_eval_root = cx->blk_eval.old_eval_root;                      \
728         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
729             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
730         if (cx->blk_eval.old_namesv)                                    \
731             sv_2mortal(cx->blk_eval.old_namesv);                        \
732     } STMT_END
733
734 /* loop context */
735 struct block_loop {
736     I32         resetsp;
737     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
738     union {     /* different ways of locating the iteration variable */
739         SV      **svp;
740         GV      *gv;
741         PAD     *oldcomppad; /* only used in ITHREADS */
742     } itervar_u;
743     union {
744         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
745             AV * ary; /* use the stack if this is NULL */
746             IV ix;
747         } ary;
748         struct { /* valid if type is LOOP_LAZYIV */
749             IV cur;
750             IV end;
751         } lazyiv;
752         struct { /* valid if type if LOOP_LAZYSV */
753             SV * cur;
754             SV * end; /* maxiumum value (or minimum in reverse) */
755         } lazysv;
756     } state_u;
757 };
758
759 #ifdef USE_ITHREADS
760 #  define CxITERVAR_PADSV(c) \
761         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
762 #else
763 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
764 #endif
765
766 #define CxITERVAR(c)                                                    \
767         ((c)->blk_loop.itervar_u.oldcomppad                             \
768          ? (CxPADLOOP(c)                                                \
769             ? CxITERVAR_PADSV(c)                                        \
770             : isGV((c)->blk_loop.itervar_u.gv)                          \
771                 ? &GvSV((c)->blk_loop.itervar_u.gv)                     \
772                 : (SV **)&(c)->blk_loop.itervar_u.gv)                   \
773          : (SV**)NULL)
774
775 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
776 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
777 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
778 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
779 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
780 /* POPSUB has already been performed on this context frame */
781 #define CxPOPSUB_DONE 0x100
782
783
784 #define PUSHLOOP_PLAIN(cx, s)                                           \
785         cx->blk_loop.resetsp = s - PL_stack_base;                       \
786         cx->blk_loop.my_op = cLOOP;                                     \
787         cx->blk_loop.state_u.ary.ary = NULL;                            \
788         cx->blk_loop.state_u.ary.ix = 0;                                \
789         cx->blk_loop.itervar_u.svp = NULL;
790
791 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
792         cx->blk_loop.resetsp = s - PL_stack_base;                       \
793         cx->blk_loop.my_op = cLOOP;                                     \
794         cx->blk_loop.state_u.ary.ary = NULL;                            \
795         cx->blk_loop.state_u.ary.ix = 0;                                \
796         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
797
798 #define POPLOOP(cx)                                                     \
799         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
800             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
801             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
802         }                                                               \
803         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
804             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
805
806 /* given/when context */
807 struct block_givwhen {
808         OP *leave_op;
809 };
810
811 #define PUSHGIVEN(cx)                                                   \
812         cx->blk_givwhen.leave_op = cLOGOP->op_other;
813
814 #define PUSHWHEN PUSHGIVEN
815
816 /* context common to subroutines, evals and loops */
817 struct block {
818     U8          blku_type;      /* what kind of context this is */
819     U8          blku_gimme;     /* is this block running in list context? */
820     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
821     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
822     COP *       blku_oldcop;    /* old curcop pointer */
823     I32         blku_oldmarksp; /* mark stack index */
824     I32         blku_oldscopesp;        /* scope stack index */
825     PMOP *      blku_oldpm;     /* values of pattern match vars */
826
827     union {
828         struct block_sub        blku_sub;
829         struct block_format     blku_format;
830         struct block_eval       blku_eval;
831         struct block_loop       blku_loop;
832         struct block_givwhen    blku_givwhen;
833     } blk_u;
834 };
835 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
836 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
837 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
838 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
839 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
840 #define blk_gimme       cx_u.cx_blk.blku_gimme
841 #define blk_u16         cx_u.cx_blk.blku_u16
842 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
843 #define blk_format      cx_u.cx_blk.blk_u.blku_format
844 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
845 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
846 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
847
848 #define DEBUG_CX(action)                                                \
849     DEBUG_l(                                                            \
850         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
851                     (long)cxstack_ix,                                   \
852                     action,                                             \
853                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
854                     (long)PL_scopestack_ix,                             \
855                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
856                     __FILE__, __LINE__));
857
858 /* Enter a block. */
859 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
860         cx->cx_type             = t,                                    \
861         cx->blk_oldsp           = sp - PL_stack_base,                   \
862         cx->blk_oldcop          = PL_curcop,                            \
863         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
864         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
865         cx->blk_oldpm           = PL_curpm,                             \
866         cx->blk_gimme           = (U8)gimme;                            \
867         DEBUG_CX("PUSH");
868
869 /* Exit a block (RETURN and LAST). */
870 #define POPBLOCK(cx,pm)                                                 \
871         DEBUG_CX("POP");                                                \
872         cx = &cxstack[cxstack_ix--],                                    \
873         newsp            = PL_stack_base + cx->blk_oldsp,               \
874         PL_curcop        = cx->blk_oldcop,                              \
875         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
876         PL_scopestack_ix = cx->blk_oldscopesp,                          \
877         pm               = cx->blk_oldpm,                               \
878         gimme            = cx->blk_gimme;
879
880 /* Continue a block elsewhere (NEXT and REDO). */
881 #define TOPBLOCK(cx)                                                    \
882         DEBUG_CX("TOP");                                                \
883         cx  = &cxstack[cxstack_ix],                                     \
884         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
885         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
886         PL_scopestack_ix = cx->blk_oldscopesp,                          \
887         PL_curpm         = cx->blk_oldpm;
888
889 /* substitution context */
890 struct subst {
891     U8          sbu_type;       /* what kind of context this is */
892     U8          sbu_rflags;
893     U16         sbu_rxtainted;  /* matches struct block */
894     I32         sbu_oldsave;
895     SSize_t     sbu_iters;
896     SSize_t     sbu_maxiters;
897     char *      sbu_orig;
898     SV *        sbu_dstr;
899     SV *        sbu_targ;
900     char *      sbu_s;
901     char *      sbu_m;
902     char *      sbu_strend;
903     void *      sbu_rxres;
904     REGEXP *    sbu_rx;
905 };
906 #define sb_iters        cx_u.cx_subst.sbu_iters
907 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
908 #define sb_rflags       cx_u.cx_subst.sbu_rflags
909 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
910 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
911 #define sb_orig         cx_u.cx_subst.sbu_orig
912 #define sb_dstr         cx_u.cx_subst.sbu_dstr
913 #define sb_targ         cx_u.cx_subst.sbu_targ
914 #define sb_s            cx_u.cx_subst.sbu_s
915 #define sb_m            cx_u.cx_subst.sbu_m
916 #define sb_strend       cx_u.cx_subst.sbu_strend
917 #define sb_rxres        cx_u.cx_subst.sbu_rxres
918 #define sb_rx           cx_u.cx_subst.sbu_rx
919
920 #ifdef PERL_CORE
921 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
922         cx->sb_iters            = iters,                                \
923         cx->sb_maxiters         = maxiters,                             \
924         cx->sb_rflags           = r_flags,                              \
925         cx->sb_oldsave          = oldsave,                              \
926         cx->sb_rxtainted        = rxtainted,                            \
927         cx->sb_orig             = orig,                                 \
928         cx->sb_dstr             = dstr,                                 \
929         cx->sb_targ             = targ,                                 \
930         cx->sb_s                = s,                                    \
931         cx->sb_m                = m,                                    \
932         cx->sb_strend           = strend,                               \
933         cx->sb_rxres            = NULL,                                 \
934         cx->sb_rx               = rx,                                   \
935         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
936         rxres_save(&cx->sb_rxres, rx);                                  \
937         (void)ReREFCNT_inc(rx);                                         \
938         SvREFCNT_inc_void_NN(targ)
939
940 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
941         rxres_free(&cx->sb_rxres);                                      \
942         ReREFCNT_dec(cx->sb_rx);                                        \
943         SvREFCNT_dec_NN(cx->sb_targ)
944 #endif
945
946 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
947
948 struct context {
949     union {
950         struct block    cx_blk;
951         struct subst    cx_subst;
952     } cx_u;
953 };
954 #define cx_type cx_u.cx_subst.sbu_type
955
956 /* If you re-order these, there is also an array of uppercase names in perl.h
957    and a static array of context names in pp_ctl.c  */
958 #define CXTYPEMASK      0xf
959 #define CXt_NULL        0
960 #define CXt_WHEN        1
961 #define CXt_BLOCK       2
962 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
963    jump table in pp_ctl.c
964    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
965 */
966 #define CXt_GIVEN       3
967 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
968 #define CXt_LOOP_FOR    4
969 #define CXt_LOOP_PLAIN  5
970 #define CXt_LOOP_LAZYSV 6
971 #define CXt_LOOP_LAZYIV 7
972 #define CXt_SUB         8
973 #define CXt_FORMAT      9
974 #define CXt_EVAL       10
975 #define CXt_SUBST      11
976 /* SUBST doesn't feature in all switch statements.  */
977
978 /* private flags for CXt_SUB and CXt_NULL
979    However, this is checked in many places which do not check the type, so
980    this bit needs to be kept clear for most everything else. For reasons I
981    haven't investigated, it can coexist with CXp_FOR_DEF */
982 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
983                                    tear down context on exit). */ 
984
985 /* private flags for CXt_SUB and CXt_FORMAT */
986 #define CXp_HASARGS     0x20
987 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
988 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
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 CXp_FOR_LVREF   0x20    /* foreach using \$var */
997 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
998
999 /* private flags for CXt_SUBST */
1000 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1001
1002 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1003 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1004 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
1005                          == CXp_MULTICALL)
1006 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1007                          == (CXt_EVAL|CXp_REAL))
1008 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1009                          == (CXt_EVAL|CXp_TRYBLOCK))
1010 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1011 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1012                          && ((c)->cx_type & CXp_FOR_DEF))
1013
1014 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1015
1016 /* 
1017 =head1 "Gimme" Values
1018 */
1019
1020 /*
1021 =for apidoc AmU||G_SCALAR
1022 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1023 L<perlcall>.
1024
1025 =for apidoc AmU||G_ARRAY
1026 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1027 L<perlcall>.
1028
1029 =for apidoc AmU||G_VOID
1030 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1031
1032 =for apidoc AmU||G_DISCARD
1033 Indicates that arguments returned from a callback should be discarded.  See
1034 L<perlcall>.
1035
1036 =for apidoc AmU||G_EVAL
1037
1038 Used to force a Perl C<eval> wrapper around a callback.  See
1039 L<perlcall>.
1040
1041 =for apidoc AmU||G_NOARGS
1042
1043 Indicates that no arguments are being sent to a callback.  See
1044 L<perlcall>.
1045
1046 =cut
1047 */
1048
1049 #define G_SCALAR        2
1050 #define G_ARRAY         3
1051 #define G_VOID          1
1052 #define G_WANT          3
1053
1054 /* extra flags for Perl_call_* routines */
1055 #define G_DISCARD       4       /* Call FREETMPS.
1056                                    Don't change this without consulting the
1057                                    hash actions codes defined in hv.h */
1058 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1059 #define G_NOARGS       16       /* Don't construct a @_ array. */
1060 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1061 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1062 #define G_METHOD      128       /* Calling method. */
1063 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1064                                    fold_constants. */
1065 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1066                                    A special case for UNSHIFT in
1067                                    Perl_magic_methcall().  */
1068 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1069                                     Perl_magic_methcall().  */
1070 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1071 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1072
1073 /* flag bits for PL_in_eval */
1074 #define EVAL_NULL       0       /* not in an eval */
1075 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1076 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1077 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1078 #define EVAL_INREQUIRE  8       /* The code is being required. */
1079 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1080
1081 /* Support for switching (stack and block) contexts.
1082  * This ensures magic doesn't invalidate local stack and cx pointers.
1083  */
1084
1085 #define PERLSI_UNKNOWN          -1
1086 #define PERLSI_UNDEF            0
1087 #define PERLSI_MAIN             1
1088 #define PERLSI_MAGIC            2
1089 #define PERLSI_SORT             3
1090 #define PERLSI_SIGNAL           4
1091 #define PERLSI_OVERLOAD         5
1092 #define PERLSI_DESTROY          6
1093 #define PERLSI_WARNHOOK         7
1094 #define PERLSI_DIEHOOK          8
1095 #define PERLSI_REQUIRE          9
1096 #define PERLSI_MULTICALL       10
1097
1098 struct stackinfo {
1099     AV *                si_stack;       /* stack for current runlevel */
1100     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1101     struct stackinfo *  si_prev;
1102     struct stackinfo *  si_next;
1103     I32                 si_cxix;        /* current context index */
1104     I32                 si_cxmax;       /* maximum allocated index */
1105     I32                 si_type;        /* type of runlevel */
1106     I32                 si_markoff;     /* offset where markstack begins for us.
1107                                          * currently used only with DEBUGGING,
1108                                          * but not #ifdef-ed for bincompat */
1109 };
1110
1111 typedef struct stackinfo PERL_SI;
1112
1113 #define cxstack         (PL_curstackinfo->si_cxstack)
1114 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1115 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1116
1117 #ifdef DEBUGGING
1118 #  define       SET_MARK_OFFSET \
1119     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1120 #else
1121 #  define       SET_MARK_OFFSET NOOP
1122 #endif
1123
1124 #define PUSHSTACKi(type) \
1125     STMT_START {                                                        \
1126         PERL_SI *next = PL_curstackinfo->si_next;                       \
1127         DEBUG_l({                                                       \
1128             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1129             while (p) { i++; p = p->si_prev; }                          \
1130             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1131                          i, __FILE__, __LINE__);})                      \
1132         if (!next) {                                                    \
1133             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1134             next->si_prev = PL_curstackinfo;                            \
1135             PL_curstackinfo->si_next = next;                            \
1136         }                                                               \
1137         next->si_type = type;                                           \
1138         next->si_cxix = -1;                                             \
1139         AvFILLp(next->si_stack) = 0;                                    \
1140         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1141         PL_curstackinfo = next;                                         \
1142         SET_MARK_OFFSET;                                                \
1143     } STMT_END
1144
1145 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1146
1147 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1148  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1149 #define POPSTACK \
1150     STMT_START {                                                        \
1151         dSP;                                                            \
1152         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1153         DEBUG_l({                                                       \
1154             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1155             while (p) { i++; p = p->si_prev; }                          \
1156             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1157                          i, __FILE__, __LINE__);})                      \
1158         if (!prev) {                                                    \
1159             Perl_croak_popstack();                                      \
1160         }                                                               \
1161         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1162         /* don't free prev here, free them all at the END{} */          \
1163         PL_curstackinfo = prev;                                         \
1164     } STMT_END
1165
1166 #define POPSTACK_TO(s) \
1167     STMT_START {                                                        \
1168         while (PL_curstack != s) {                                      \
1169             dounwind(-1);                                               \
1170             POPSTACK;                                                   \
1171         }                                                               \
1172     } STMT_END
1173
1174 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1175 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1176
1177 /*
1178 =head1 Multicall Functions
1179
1180 =for apidoc Ams||dMULTICALL
1181 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1182
1183 =for apidoc Ams||PUSH_MULTICALL
1184 Opening bracket for a lightweight callback.
1185 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1186
1187 =for apidoc Ams||MULTICALL
1188 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1189
1190 =for apidoc Ams||POP_MULTICALL
1191 Closing bracket for a lightweight callback.
1192 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1193
1194 =cut
1195 */
1196
1197 #define dMULTICALL \
1198     SV **newsp;                 /* set by POPBLOCK */                   \
1199     PERL_CONTEXT *cx;                                                   \
1200     CV *multicall_cv;                                                   \
1201     OP *multicall_cop;                                                  \
1202     bool multicall_oldcatch;                                            \
1203     U8 hasargs = 0              /* used by PUSHSUB */
1204
1205 #define PUSH_MULTICALL(the_cv) \
1206     PUSH_MULTICALL_FLAGS(the_cv, 0)
1207
1208 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1209  * for the CX stack entry (this isn't part of the public API) */
1210
1211 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1212     STMT_START {                                                        \
1213         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1214         CV * const cv = _nOnclAshIngNamE_;                              \
1215         PADLIST * const padlist = CvPADLIST(cv);                        \
1216         ENTER;                                                          \
1217         multicall_oldcatch = CATCH_GET;                                 \
1218         SAVETMPS; SAVEVPTR(PL_op);                                      \
1219         CATCH_SET(TRUE);                                                \
1220         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1221         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1222         PUSHSUB(cx);                                                    \
1223         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1224             CvDEPTH(cv)++;                                              \
1225         if (CvDEPTH(cv) >= 2) {                                         \
1226             PERL_STACK_OVERFLOW_CHECK();                                \
1227             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1228         }                                                               \
1229         SAVECOMPPAD();                                                  \
1230         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1231         multicall_cv = cv;                                              \
1232         multicall_cop = CvSTART(cv);                                    \
1233     } STMT_END
1234
1235 #define MULTICALL \
1236     STMT_START {                                                        \
1237         PL_op = multicall_cop;                                          \
1238         CALLRUNOPS(aTHX);                                               \
1239     } STMT_END
1240
1241 #define POP_MULTICALL \
1242     STMT_START {                                                        \
1243         cx = &cxstack[cxstack_ix];                                      \
1244         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1245         LEAVESUB(multicall_cv);                                         \
1246         POPBLOCK(cx,PL_curpm);                                          \
1247         POPSTACK;                                                       \
1248         CATCH_SET(multicall_oldcatch);                                  \
1249         LEAVE;                                                          \
1250         SPAGAIN;                                                        \
1251     } STMT_END
1252
1253 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1254  * (this isn't part of the public API) */
1255
1256 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1257     STMT_START {                                                        \
1258         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1259         CV * const cv = _nOnclAshIngNamE_;                              \
1260         PADLIST * const padlist = CvPADLIST(cv);                        \
1261         cx = &cxstack[cxstack_ix];                                      \
1262         assert(cx->cx_type & CXp_MULTICALL);                            \
1263         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1264         LEAVESUB(multicall_cv);                                         \
1265         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1266         PUSHSUB(cx);                                                    \
1267         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1268             CvDEPTH(cv)++;                                              \
1269         if (CvDEPTH(cv) >= 2) {                                         \
1270             PERL_STACK_OVERFLOW_CHECK();                                \
1271             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1272         }                                                               \
1273         SAVECOMPPAD();                                                  \
1274         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1275         multicall_cv = cv;                                              \
1276         multicall_cop = CvSTART(cv);                                    \
1277     } STMT_END
1278 /*
1279  * ex: set ts=8 sts=4 sw=4 et:
1280  */