perldelta for $@=3; warn
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a PL_start_env initialized when perl starts, and
18  * PL_top_env points to this initially, so PL_top_env should always be
19  * non-null.
20  *
21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
23  * null to ensure this).
24  *
25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
26  * establish a local jmpenv to handle exception traps.  Care must be taken
27  * to restore the previous value of je_mustcatch before exiting the
28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
29  * GSAR 97-03-27
30  */
31
32 struct jmpenv {
33     struct jmpenv *     je_prev;
34     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
35     int                 je_ret;         /* last exception thrown */
36     bool                je_mustcatch;   /* need to call longjmp()? */
37 };
38
39 typedef struct jmpenv JMPENV;
40
41 #ifdef OP_IN_REGISTER
42 #define OP_REG_TO_MEM   PL_opsave = op
43 #define OP_MEM_TO_REG   op = PL_opsave
44 #else
45 #define OP_REG_TO_MEM   NOOP
46 #define OP_MEM_TO_REG   NOOP
47 #endif
48
49 /*
50  * How to build the first jmpenv.
51  *
52  * top_env needs to be non-zero. It points to an area
53  * in which longjmp() stuff is stored, as C callstack
54  * info there at least is thread specific this has to
55  * be per-thread. Otherwise a 'die' in a thread gives
56  * that thread the C stack of last thread to do an eval {}!
57  */
58
59 #define JMPENV_BOOTSTRAP \
60     STMT_START {                                \
61         Zero(&PL_start_env, 1, JMPENV);         \
62         PL_start_env.je_ret = -1;               \
63         PL_start_env.je_mustcatch = TRUE;       \
64         PL_top_env = &PL_start_env;             \
65     } STMT_END
66
67 /*
68  *   PERL_FLEXIBLE_EXCEPTIONS
69  * 
70  * All the flexible exceptions code has been removed.
71  * See the following threads for details:
72  *
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
74  * 
75  * Joshua's original patches (which weren't applied) and discussion:
76  * 
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
82  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
83  * 
84  * Chip's reworked patch and discussion:
85  * 
86  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
87  * 
88  * The flaw in these patches (which went unnoticed at the time) was
89  * that they moved some code that could potentially die() out of the
90  * region protected by the setjmp()s.  This caused exceptions within
91  * END blocks and such to not be handled by the correct setjmp().
92  * 
93  * The original patches that introduces flexible exceptions were:
94  *
95  * http://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 #  ifdef DEBUGGING
424 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
425                                    GvAV(gv_fetchfile(CopFILE(c))))
426 #  else
427 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
428 #  endif
429
430 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
431 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
432                                     ? alloccopstash(hv)                 \
433                                     : 0)
434 #  ifdef NETWARE
435 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
436 #  else
437 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
438 #  endif
439 #else
440 #  define CopFILEGV(c)          ((c)->cop_filegv)
441 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
442 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
443 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
444 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
445 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
446 #  ifdef DEBUGGING
447 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
448 #  else
449 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
450 # endif
451 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
452                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
453 #  define CopSTASH(c)           ((c)->cop_stash)
454 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
455 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
456
457 #endif /* USE_ITHREADS */
458
459 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
460    /* cop_stash is not refcounted */
461 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
462 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
463
464 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
465 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
466
467 /*
468 =head1 COP Hint Reading
469 */
470
471 /*
472 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
473
474 Look up the hint entry in the cop I<cop> with the key specified by
475 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
476 the key octets are interpreted as UTF-8, otherwise they are interpreted
477 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
478 it has not been precomputed.  Returns a mortal scalar copy of the value
479 associated with the key, or C<&PL_sv_placeholder> if there is no value
480 associated with the key.
481
482 =cut
483 */
484
485 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
486     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
487
488 /*
489 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
490
491 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
492 string/length pair, and no precomputed hash.
493
494 =cut
495 */
496
497 #define cop_hints_fetch_pvs(cop, key, flags) \
498     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
499
500 /*
501 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
502
503 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
504 of a string/length pair.
505
506 =cut
507 */
508
509 #define cop_hints_fetch_pv(cop, key, hash, flags) \
510     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
511
512 /*
513 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
514
515 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
516 string/length pair.
517
518 =cut
519 */
520
521 #define cop_hints_fetch_sv(cop, key, hash, flags) \
522     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
523
524 /*
525 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
526
527 Generates and returns a standard Perl hash representing the full set of
528 hint entries in the cop I<cop>.  I<flags> is currently unused and must
529 be zero.
530
531 =cut
532 */
533
534 #define cop_hints_2hv(cop, flags) \
535     cophh_2hv(CopHINTHASH_get(cop), flags)
536
537 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
538 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
539 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
540 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
541
542 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
543 #define CopLINE(c)              ((c)->cop_line)
544 #define CopLINE_inc(c)          (++CopLINE(c))
545 #define CopLINE_dec(c)          (--CopLINE(c))
546 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
547
548 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
549 #define OutCopFILE(c) CopFILE(c)
550
551 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
552 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
553 #define CopHINTS_set(c, h)      STMT_START {                            \
554                                     (c)->cop_hints = (h);               \
555                                 } STMT_END
556
557 /*
558  * Here we have some enormously heavy (or at least ponderous) wizardry.
559  */
560
561 /* subroutine context */
562 struct block_sub {
563     OP *        retop;  /* op to execute on exit from sub */
564     /* Above here is the same for sub, format and eval.  */
565     CV *        cv;
566     /* Above here is the same for sub and format.  */
567     AV *        savearray;
568     AV *        argarray;
569     I32         olddepth;
570     PAD         *oldcomppad;
571 };
572
573
574 /* format context */
575 struct block_format {
576     OP *        retop;  /* op to execute on exit from sub */
577     /* Above here is the same for sub, format and eval.  */
578     CV *        cv;
579     /* Above here is the same for sub and format.  */
580     GV *        gv;
581     GV *        dfoutgv;
582 };
583
584 /* base for the next two macros. Don't use directly.
585  * Note that the refcnt of the cv is incremented twice;  The CX one is
586  * decremented by LEAVESUB, the other by LEAVE. */
587
588 #define PUSHSUB_BASE(cx)                                                \
589         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
590                 CopFILE((const COP *)CvSTART(cv)),                      \
591                 CopLINE((const COP *)CvSTART(cv)),                      \
592                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
593                                                                         \
594         cx->blk_sub.cv = cv;                                            \
595         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
596         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
597         cx->blk_sub.retop = NULL;                                       \
598         if (!CvDEPTH(cv)) {                                             \
599             SvREFCNT_inc_simple_void_NN(cv);                            \
600             SvREFCNT_inc_simple_void_NN(cv);                            \
601             SAVEFREESV(cv);                                             \
602         }
603
604
605 #define PUSHSUB(cx)                                                     \
606     {                                                                   \
607         /* If the context is indeterminate, then only the lvalue */     \
608         /* flags that the caller also has are applicable.        */     \
609         U8 phlags =                                                     \
610            (PL_op->op_flags & OPf_WANT)                                 \
611                ? OPpENTERSUB_LVAL_MASK                                  \
612                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
613                    ? 0 : Perl_was_lvalue_sub(aTHX);                     \
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         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
631
632 #define POP_SAVEARRAY()                                         \
633     STMT_START {                                                        \
634         SvREFCNT_dec(GvAV(PL_defgv));                                   \
635         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
636     } STMT_END
637
638 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
639  * leave any (a fast av_clear(ary), basically) */
640 #define CLEAR_ARGARRAY(ary) \
641     STMT_START {                                                        \
642         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
643         AvARRAY(ary) = AvALLOC(ary);                                    \
644         AvFILLp(ary) = -1;                                              \
645     } STMT_END
646
647 #define POPSUB(cx,sv)                                                   \
648     STMT_START {                                                        \
649         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
650                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
651                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
652                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
653                                                                         \
654         if (CxHASARGS(cx)) {                                            \
655             POP_SAVEARRAY();                                            \
656             /* abandon @_ if it got reified */                          \
657             if (AvREAL(cx->blk_sub.argarray)) {                         \
658                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
659                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
660                 cx->blk_sub.argarray = newAV();                         \
661                 av_extend(cx->blk_sub.argarray, fill);                  \
662                 AvREIFY_only(cx->blk_sub.argarray);                     \
663                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
664             }                                                           \
665             else {                                                      \
666                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
667             }                                                           \
668         }                                                               \
669         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
670         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
671             sv = NULL;                                          \
672     } STMT_END
673
674 #define LEAVESUB(sv)                                                    \
675     STMT_START {                                                        \
676         if (sv)                                                         \
677             SvREFCNT_dec(sv);                                           \
678     } STMT_END
679
680 #define POPFORMAT(cx)                                                   \
681         setdefout(cx->blk_format.dfoutgv);                              \
682         SvREFCNT_dec(cx->blk_format.dfoutgv);
683
684 /* eval context */
685 struct block_eval {
686     OP *        retop;  /* op to execute on exit from eval */
687     /* Above here is the same for sub, format and eval.  */
688     SV *        old_namesv;
689     OP *        old_eval_root;
690     SV *        cur_text;
691     CV *        cv;
692     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
693 };
694
695 /* If we ever need more than 512 op types, change the shift from 7.
696    blku_gimme is actually also only 2 bits, so could be merged with something.
697 */
698
699 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
700 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
701
702 #define PUSHEVAL(cx,n)                                                  \
703     STMT_START {                                                        \
704         assert(!(PL_in_eval & ~0x7F));                                  \
705         assert(!(PL_op->op_type & ~0x1FF));                             \
706         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
707         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
708         cx->blk_eval.old_eval_root = PL_eval_root;                      \
709         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
710         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
711         cx->blk_eval.retop = NULL;                                      \
712         cx->blk_eval.cur_top_env = PL_top_env;                          \
713     } STMT_END
714
715 #define POPEVAL(cx)                                                     \
716     STMT_START {                                                        \
717         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
718         optype = CxOLD_OP_TYPE(cx);                                     \
719         PL_eval_root = cx->blk_eval.old_eval_root;                      \
720         if (cx->blk_eval.old_namesv)                                    \
721             sv_2mortal(cx->blk_eval.old_namesv);                        \
722     } STMT_END
723
724 /* loop context */
725 struct block_loop {
726     I32         resetsp;
727     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
728     union {     /* different ways of locating the iteration variable */
729         SV      **svp;
730         GV      *gv;
731         PAD     *oldcomppad; /* only used in ITHREADS */
732     } itervar_u;
733     union {
734         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
735             AV * ary; /* use the stack if this is NULL */
736             IV ix;
737         } ary;
738         struct { /* valid if type is LOOP_LAZYIV */
739             IV cur;
740             IV end;
741         } lazyiv;
742         struct { /* valid if type if LOOP_LAZYSV */
743             SV * cur;
744             SV * end; /* maxiumum value (or minimum in reverse) */
745         } lazysv;
746     } state_u;
747 };
748
749 #ifdef USE_ITHREADS
750 #  define CxITERVAR_PADSV(c) \
751         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
752 #else
753 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
754 #endif
755
756 #define CxITERVAR(c)                                                    \
757         ((c)->blk_loop.itervar_u.oldcomppad                             \
758          ? (CxPADLOOP(c)                                                \
759             ? CxITERVAR_PADSV(c)                                        \
760             : &GvSV((c)->blk_loop.itervar_u.gv))                        \
761          : (SV**)NULL)
762
763 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
764 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
765 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
766 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
767 #define CxLVAL(c)       (0 + (c)->blk_u16)
768
769 #define PUSHLOOP_PLAIN(cx, s)                                           \
770         cx->blk_loop.resetsp = s - PL_stack_base;                       \
771         cx->blk_loop.my_op = cLOOP;                                     \
772         cx->blk_loop.state_u.ary.ary = NULL;                            \
773         cx->blk_loop.state_u.ary.ix = 0;                                \
774         cx->blk_loop.itervar_u.svp = NULL;
775
776 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
777         cx->blk_loop.resetsp = s - PL_stack_base;                       \
778         cx->blk_loop.my_op = cLOOP;                                     \
779         cx->blk_loop.state_u.ary.ary = NULL;                            \
780         cx->blk_loop.state_u.ary.ix = 0;                                \
781         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
782
783 #define POPLOOP(cx)                                                     \
784         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
785             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
786             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
787         }                                                               \
788         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
789             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
790
791 /* given/when context */
792 struct block_givwhen {
793         OP *leave_op;
794 };
795
796 #define PUSHGIVEN(cx)                                                   \
797         cx->blk_givwhen.leave_op = cLOGOP->op_other;
798
799 #define PUSHWHEN PUSHGIVEN
800
801 /* context common to subroutines, evals and loops */
802 struct block {
803     U8          blku_type;      /* what kind of context this is */
804     U8          blku_gimme;     /* is this block running in list context? */
805     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
806     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
807     COP *       blku_oldcop;    /* old curcop pointer */
808     I32         blku_oldmarksp; /* mark stack index */
809     I32         blku_oldscopesp;        /* scope stack index */
810     PMOP *      blku_oldpm;     /* values of pattern match vars */
811
812     union {
813         struct block_sub        blku_sub;
814         struct block_format     blku_format;
815         struct block_eval       blku_eval;
816         struct block_loop       blku_loop;
817         struct block_givwhen    blku_givwhen;
818     } blk_u;
819 };
820 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
821 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
822 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
823 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
824 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
825 #define blk_gimme       cx_u.cx_blk.blku_gimme
826 #define blk_u16         cx_u.cx_blk.blku_u16
827 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
828 #define blk_format      cx_u.cx_blk.blk_u.blku_format
829 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
830 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
831 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
832
833 #define DEBUG_CX(action)                                                \
834     DEBUG_l(                                                            \
835         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
836                     (long)cxstack_ix,                                   \
837                     action,                                             \
838                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
839                     (long)PL_scopestack_ix,                             \
840                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
841                     __FILE__, __LINE__));
842
843 /* Enter a block. */
844 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
845         cx->cx_type             = t,                                    \
846         cx->blk_oldsp           = sp - PL_stack_base,                   \
847         cx->blk_oldcop          = PL_curcop,                            \
848         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
849         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
850         cx->blk_oldpm           = PL_curpm,                             \
851         cx->blk_gimme           = (U8)gimme;                            \
852         DEBUG_CX("PUSH");
853
854 /* Exit a block (RETURN and LAST). */
855 #define POPBLOCK(cx,pm)                                                 \
856         DEBUG_CX("POP");                                                \
857         cx = &cxstack[cxstack_ix--],                                    \
858         newsp            = PL_stack_base + cx->blk_oldsp,               \
859         PL_curcop        = cx->blk_oldcop,                              \
860         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
861         PL_scopestack_ix = cx->blk_oldscopesp,                          \
862         pm               = cx->blk_oldpm,                               \
863         gimme            = cx->blk_gimme;
864
865 /* Continue a block elsewhere (NEXT and REDO). */
866 #define TOPBLOCK(cx)                                                    \
867         DEBUG_CX("TOP");                                                \
868         cx  = &cxstack[cxstack_ix],                                     \
869         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
870         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
871         PL_scopestack_ix = cx->blk_oldscopesp,                          \
872         PL_curpm         = cx->blk_oldpm;
873
874 /* substitution context */
875 struct subst {
876     U8          sbu_type;       /* what kind of context this is */
877     U8          sbu_rflags;
878     U16         sbu_rxtainted;  /* matches struct block */
879     I32         sbu_iters;
880     I32         sbu_maxiters;
881     I32         sbu_oldsave;
882     char *      sbu_orig;
883     SV *        sbu_dstr;
884     SV *        sbu_targ;
885     char *      sbu_s;
886     char *      sbu_m;
887     char *      sbu_strend;
888     void *      sbu_rxres;
889     REGEXP *    sbu_rx;
890 };
891 #define sb_iters        cx_u.cx_subst.sbu_iters
892 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
893 #define sb_rflags       cx_u.cx_subst.sbu_rflags
894 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
895 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
896 #define sb_orig         cx_u.cx_subst.sbu_orig
897 #define sb_dstr         cx_u.cx_subst.sbu_dstr
898 #define sb_targ         cx_u.cx_subst.sbu_targ
899 #define sb_s            cx_u.cx_subst.sbu_s
900 #define sb_m            cx_u.cx_subst.sbu_m
901 #define sb_strend       cx_u.cx_subst.sbu_strend
902 #define sb_rxres        cx_u.cx_subst.sbu_rxres
903 #define sb_rx           cx_u.cx_subst.sbu_rx
904
905 #ifdef PERL_CORE
906 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
907         cx->sb_iters            = iters,                                \
908         cx->sb_maxiters         = maxiters,                             \
909         cx->sb_rflags           = r_flags,                              \
910         cx->sb_oldsave          = oldsave,                              \
911         cx->sb_rxtainted        = rxtainted,                            \
912         cx->sb_orig             = orig,                                 \
913         cx->sb_dstr             = dstr,                                 \
914         cx->sb_targ             = targ,                                 \
915         cx->sb_s                = s,                                    \
916         cx->sb_m                = m,                                    \
917         cx->sb_strend           = strend,                               \
918         cx->sb_rxres            = NULL,                                 \
919         cx->sb_rx               = rx,                                   \
920         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
921         rxres_save(&cx->sb_rxres, rx);                                  \
922         (void)ReREFCNT_inc(rx)
923
924 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
925         rxres_free(&cx->sb_rxres);                                      \
926         ReREFCNT_dec(cx->sb_rx)
927 #endif
928
929 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
930
931 struct context {
932     union {
933         struct block    cx_blk;
934         struct subst    cx_subst;
935     } cx_u;
936 };
937 #define cx_type cx_u.cx_subst.sbu_type
938
939 /* If you re-order these, there is also an array of uppercase names in perl.h
940    and a static array of context names in pp_ctl.c  */
941 #define CXTYPEMASK      0xf
942 #define CXt_NULL        0
943 #define CXt_WHEN        1
944 #define CXt_BLOCK       2
945 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
946    jump table in pp_ctl.c
947    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
948 */
949 #define CXt_GIVEN       3
950 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
951 #define CXt_LOOP_FOR    4
952 #define CXt_LOOP_PLAIN  5
953 #define CXt_LOOP_LAZYSV 6
954 #define CXt_LOOP_LAZYIV 7
955 #define CXt_SUB         8
956 #define CXt_FORMAT      9
957 #define CXt_EVAL       10
958 #define CXt_SUBST      11
959 /* SUBST doesn't feature in all switch statements.  */
960
961 /* private flags for CXt_SUB and CXt_NULL
962    However, this is checked in many places which do not check the type, so
963    this bit needs to be kept clear for most everything else. For reasons I
964    haven't investigated, it can coexist with CXp_FOR_DEF */
965 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
966                                    tear down context on exit). */ 
967
968 /* private flags for CXt_SUB and CXt_FORMAT */
969 #define CXp_HASARGS     0x20
970
971 /* private flags for CXt_EVAL */
972 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
973 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
974
975 /* private flags for CXt_LOOP */
976 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
977 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
978
979 /* private flags for CXt_SUBST */
980 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
981
982 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
983 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
984 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
985                          == CXp_MULTICALL)
986 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
987                          == (CXt_EVAL|CXp_REAL))
988 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
989                          == (CXt_EVAL|CXp_TRYBLOCK))
990 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
991 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
992                          && ((c)->cx_type & CXp_FOR_DEF))
993
994 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
995
996 /* 
997 =head1 "Gimme" Values
998 */
999
1000 /*
1001 =for apidoc AmU||G_SCALAR
1002 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
1003 L<perlcall>.
1004
1005 =for apidoc AmU||G_ARRAY
1006 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
1007 L<perlcall>.
1008
1009 =for apidoc AmU||G_VOID
1010 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
1011
1012 =for apidoc AmU||G_DISCARD
1013 Indicates that arguments returned from a callback should be discarded.  See
1014 L<perlcall>.
1015
1016 =for apidoc AmU||G_EVAL
1017
1018 Used to force a Perl C<eval> wrapper around a callback.  See
1019 L<perlcall>.
1020
1021 =for apidoc AmU||G_NOARGS
1022
1023 Indicates that no arguments are being sent to a callback.  See
1024 L<perlcall>.
1025
1026 =cut
1027 */
1028
1029 #define G_SCALAR        2
1030 #define G_ARRAY         3
1031 #define G_VOID          1
1032 #define G_WANT          3
1033
1034 /* extra flags for Perl_call_* routines */
1035 #define G_DISCARD       4       /* Call FREETMPS.
1036                                    Don't change this without consulting the
1037                                    hash actions codes defined in hv.h */
1038 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1039 #define G_NOARGS       16       /* Don't construct a @_ array. */
1040 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1041 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1042 #define G_METHOD      128       /* Calling method. */
1043 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1044                                    fold_constants. */
1045 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1046                                    A special case for UNSHIFT in
1047                                    Perl_magic_methcall().  */
1048 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1049                                     Perl_magic_methcall().  */
1050
1051 /* flag bits for PL_in_eval */
1052 #define EVAL_NULL       0       /* not in an eval */
1053 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1054 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1055 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1056 #define EVAL_INREQUIRE  8       /* The code is being required. */
1057
1058 /* Support for switching (stack and block) contexts.
1059  * This ensures magic doesn't invalidate local stack and cx pointers.
1060  */
1061
1062 #define PERLSI_UNKNOWN          -1
1063 #define PERLSI_UNDEF            0
1064 #define PERLSI_MAIN             1
1065 #define PERLSI_MAGIC            2
1066 #define PERLSI_SORT             3
1067 #define PERLSI_SIGNAL           4
1068 #define PERLSI_OVERLOAD         5
1069 #define PERLSI_DESTROY          6
1070 #define PERLSI_WARNHOOK         7
1071 #define PERLSI_DIEHOOK          8
1072 #define PERLSI_REQUIRE          9
1073
1074 struct stackinfo {
1075     AV *                si_stack;       /* stack for current runlevel */
1076     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1077     struct stackinfo *  si_prev;
1078     struct stackinfo *  si_next;
1079     I32                 si_cxix;        /* current context index */
1080     I32                 si_cxmax;       /* maximum allocated index */
1081     I32                 si_type;        /* type of runlevel */
1082     I32                 si_markoff;     /* offset where markstack begins for us.
1083                                          * currently used only with DEBUGGING,
1084                                          * but not #ifdef-ed for bincompat */
1085 };
1086
1087 typedef struct stackinfo PERL_SI;
1088
1089 #define cxstack         (PL_curstackinfo->si_cxstack)
1090 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1091 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1092
1093 #ifdef DEBUGGING
1094 #  define       SET_MARK_OFFSET \
1095     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1096 #else
1097 #  define       SET_MARK_OFFSET NOOP
1098 #endif
1099
1100 #define PUSHSTACKi(type) \
1101     STMT_START {                                                        \
1102         PERL_SI *next = PL_curstackinfo->si_next;                       \
1103         DEBUG_l({                                                       \
1104             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1105             while (p) { i++; p = p->si_prev; }                          \
1106             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1107                          i, __FILE__, __LINE__);})                      \
1108         if (!next) {                                                    \
1109             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1110             next->si_prev = PL_curstackinfo;                            \
1111             PL_curstackinfo->si_next = next;                            \
1112         }                                                               \
1113         next->si_type = type;                                           \
1114         next->si_cxix = -1;                                             \
1115         AvFILLp(next->si_stack) = 0;                                    \
1116         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1117         PL_curstackinfo = next;                                         \
1118         SET_MARK_OFFSET;                                                \
1119     } STMT_END
1120
1121 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1122
1123 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1124  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1125 #define POPSTACK \
1126     STMT_START {                                                        \
1127         dSP;                                                            \
1128         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1129         DEBUG_l({                                                       \
1130             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1131             while (p) { i++; p = p->si_prev; }                          \
1132             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1133                          i, __FILE__, __LINE__);})                      \
1134         if (!prev) {                                                    \
1135             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
1136             my_exit(1);                                                 \
1137         }                                                               \
1138         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1139         /* don't free prev here, free them all at the END{} */          \
1140         PL_curstackinfo = prev;                                         \
1141     } STMT_END
1142
1143 #define POPSTACK_TO(s) \
1144     STMT_START {                                                        \
1145         while (PL_curstack != s) {                                      \
1146             dounwind(-1);                                               \
1147             POPSTACK;                                                   \
1148         }                                                               \
1149     } STMT_END
1150
1151 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1152 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1153
1154 /*
1155 =head1 Multicall Functions
1156
1157 =for apidoc Ams||dMULTICALL
1158 Declare local variables for a multicall. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1159
1160 =for apidoc Ams||PUSH_MULTICALL
1161 Opening bracket for a lightweight callback.
1162 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1163
1164 =for apidoc Ams||MULTICALL
1165 Make a lightweight callback. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1166
1167 =for apidoc Ams||POP_MULTICALL
1168 Closing bracket for a lightweight callback.
1169 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1170
1171 =cut
1172 */
1173
1174 #define dMULTICALL \
1175     SV **newsp;                 /* set by POPBLOCK */                   \
1176     PERL_CONTEXT *cx;                                                   \
1177     CV *multicall_cv;                                                   \
1178     OP *multicall_cop;                                                  \
1179     bool multicall_oldcatch;                                            \
1180     U8 hasargs = 0              /* used by PUSHSUB */
1181
1182 #define PUSH_MULTICALL(the_cv) \
1183     STMT_START {                                                        \
1184         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1185         CV * const cv = _nOnclAshIngNamE_;                              \
1186         AV * const padlist = CvPADLIST(cv);                             \
1187         ENTER;                                                          \
1188         multicall_oldcatch = CATCH_GET;                                 \
1189         SAVETMPS; SAVEVPTR(PL_op);                                      \
1190         CATCH_SET(TRUE);                                                \
1191         PUSHSTACKi(PERLSI_SORT);                                        \
1192         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
1193         PUSHSUB(cx);                                                    \
1194         if (++CvDEPTH(cv) >= 2) {                                       \
1195             PERL_STACK_OVERFLOW_CHECK();                                \
1196             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1197         }                                                               \
1198         SAVECOMPPAD();                                                  \
1199         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1200         multicall_cv = cv;                                              \
1201         multicall_cop = CvSTART(cv);                                    \
1202     } STMT_END
1203
1204 #define MULTICALL \
1205     STMT_START {                                                        \
1206         PL_op = multicall_cop;                                          \
1207         CALLRUNOPS(aTHX);                                               \
1208     } STMT_END
1209
1210 #define POP_MULTICALL \
1211     STMT_START {                                                        \
1212         if (! --CvDEPTH(multicall_cv))                                  \
1213             LEAVESUB(multicall_cv);                                     \
1214         POPBLOCK(cx,PL_curpm);                                          \
1215         POPSTACK;                                                       \
1216         CATCH_SET(multicall_oldcatch);                                  \
1217         LEAVE;                                                          \
1218         SPAGAIN;                                                        \
1219     } STMT_END
1220
1221 /*
1222  * Local variables:
1223  * c-indentation-style: bsd
1224  * c-basic-offset: 4
1225  * indent-tabs-mode: nil
1226  * End:
1227  *
1228  * ex: set ts=8 sts=4 sw=4 et:
1229  */