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[perl5.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are 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     PAD         *prevcomppad; /* the caller's PL_comppad */
555     CV *        cv;
556     /* Above here is the same for sub and format.  */
557     I32         olddepth;
558     AV          *savearray;
559 };
560
561
562 /* format context */
563 struct block_format {
564     OP *        retop;  /* op to execute on exit from sub */
565     /* Above here is the same for sub, format and eval.  */
566     PAD         *prevcomppad; /* the caller's PL_comppad */
567     CV *        cv;
568     /* Above here is the same for sub and format.  */
569     GV *        gv;
570     GV *        dfoutgv;
571 };
572
573 /* return a pointer to the current context */
574
575 #define CX_CUR() (&cxstack[cxstack_ix])
576
577 /* free all savestack items back to the watermark of the specified context */
578
579 #define CX_LEAVE_SCOPE(cx) LEAVE_SCOPE(cx->blk_oldsaveix)
580
581 #ifdef DEBUGGING
582 /* on debugging builds, poison cx afterwards so we know no code
583  * uses it - because after doing cxstack_ix--, any ties, exceptions etc
584  * may overwrite the current stack frame */
585 #  define CX_POP(cx)                                                   \
586         assert(CX_CUR() == cx);                                        \
587         cxstack_ix--;                                                  \
588         cx = NULL;
589 #else
590 #  define CX_POP(cx) cxstack_ix--;
591 #endif
592
593
594 /* base for the next two macros. Don't use directly.
595  * The context frame holds a reference to the CV so that it can't be
596  * freed while we're executing it */
597
598 #define PUSHSUB_BASE(cx)                                                \
599         ENTRY_PROBE(CvNAMED(cv)                                         \
600                         ? HEK_KEY(CvNAME_HEK(cv))                       \
601                         : GvENAME(CvGV(cv)),                            \
602                 CopFILE((const COP *)CvSTART(cv)),                      \
603                 CopLINE((const COP *)CvSTART(cv)),                      \
604                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
605                                                                         \
606         cx->blk_sub.cv = cv;                                            \
607         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
608         cx->blk_sub.prevcomppad = PL_comppad;                           \
609         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
610         cx->blk_sub.retop = NULL;                                       \
611         SvREFCNT_inc_simple_void_NN(cv);
612
613 #define PUSHSUB_GET_LVALUE_MASK(func) \
614         /* If the context is indeterminate, then only the lvalue */     \
615         /* flags that the caller also has are applicable.        */     \
616         (                                                               \
617            (PL_op->op_flags & OPf_WANT)                                 \
618                ? OPpENTERSUB_LVAL_MASK                                  \
619                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
620                    ? 0 : (U8)func(aTHX)                                 \
621         )
622
623 #define PUSHSUB(cx)                                                     \
624     {                                                                   \
625         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
626         PUSHSUB_BASE(cx)                                                \
627         cx->blk_u16 = PL_op->op_private &                               \
628                           (phlags|OPpDEREF);                            \
629     }
630
631 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
632 #define PUSHSUB_DB(cx)                                                  \
633         PUSHSUB_BASE(cx)                                                \
634         cx->blk_u16 = 0;
635
636
637 #define PUSHFORMAT(cx, retop)                                           \
638         cx->blk_format.cv = cv;                                         \
639         cx->blk_format.gv = gv;                                         \
640         cx->blk_format.retop = (retop);                                 \
641         cx->blk_format.dfoutgv = PL_defoutgv;                           \
642         cx->blk_format.prevcomppad = PL_comppad;                        \
643         cx->blk_u16 = 0;                                                \
644         cx->blk_oldsaveix = PL_savestack_ix;                            \
645         SvREFCNT_inc_simple_void_NN(cv);                                \
646         CvDEPTH(cv)++;                                                  \
647         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
648
649 /* Restore old @_ */
650 #define POP_SAVEARRAY(cx)                                               \
651     STMT_START {                                                        \
652         AV *av = GvAV(PL_defgv);                                        \
653         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
654         cx->blk_sub.savearray = NULL;                                   \
655         SvREFCNT_dec(av);                                               \
656     } STMT_END
657
658 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
659  * leave any (a fast av_clear(ary), basically) */
660 #define CLEAR_ARGARRAY(ary) \
661     STMT_START {                                                        \
662         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
663         AvARRAY(ary) = AvALLOC(ary);                                    \
664         AvFILLp(ary) = -1;                                              \
665     } STMT_END
666
667
668 /* subsets of POPSUB */
669
670 #define POPSUB_COMMON(cx) \
671     STMT_START {                                                        \
672         CV *cv;                                                         \
673         PL_comppad = cx->blk_sub.prevcomppad;                           \
674         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
675         cv = cx->blk_sub.cv;                                            \
676         CvDEPTH(cv) = cx->blk_sub.olddepth;                             \
677         cx->blk_sub.cv = NULL;                                          \
678         SvREFCNT_dec(cv);                                               \
679     } STMT_END
680
681 /* handle the @_ part of leaving a sub */
682
683 #define POPSUB_ARGS(cx) \
684     STMT_START {                                                        \
685         AV *av;                                                         \
686         assert(AvARRAY(MUTABLE_AV(                                      \
687             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
688                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
689         POP_SAVEARRAY(cx);                                              \
690         av = MUTABLE_AV(PAD_SVl(0));                                    \
691         if (UNLIKELY(AvREAL(av)))                                       \
692             /* abandon @_ if it got reified */                          \
693             clear_defarray(av, 0);                                      \
694         else {                                                          \
695             CLEAR_ARGARRAY(av);                                         \
696         }                                                               \
697     } STMT_END
698
699 #define POPSUB(cx)                                                      \
700     STMT_START {                                                        \
701         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
702                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
703                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
704                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
705                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
706                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
707                                                                         \
708         if (CxHASARGS(cx)) {                                            \
709             POPSUB_ARGS(cx);                                            \
710         }                                                               \
711         POPSUB_COMMON(cx);                                              \
712     } STMT_END
713
714 #define POPFORMAT(cx)                                                   \
715     STMT_START {                                                        \
716         CV *cv;                                                         \
717         GV * const dfout = cx->blk_format.dfoutgv;                      \
718         setdefout(dfout);                                               \
719         cx->blk_format.dfoutgv = NULL;                                  \
720         SvREFCNT_dec_NN(dfout); /* the cx->defoutgv ref */              \
721         PL_comppad = cx->blk_format.prevcomppad;                        \
722         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
723         cv = cx->blk_format.cv;                                         \
724         cx->blk_format.cv = NULL;;                                      \
725         --CvDEPTH(cv);                                                  \
726         SvREFCNT_dec_NN(cv);                                            \
727     } STMT_END
728
729 /* eval context */
730 struct block_eval {
731     OP *        retop;  /* op to execute on exit from eval */
732     /* Above here is the same for sub, format and eval.  */
733     SV *        old_namesv;
734     OP *        old_eval_root;
735     SV *        cur_text;
736     CV *        cv;
737     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
738 };
739
740 /* If we ever need more than 512 op types, change the shift from 7.
741    blku_gimme is actually also only 2 bits, so could be merged with something.
742 */
743
744 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
745 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
746
747 #define PUSHEVAL(cx,n)                                                  \
748     STMT_START {                                                        \
749         assert(!(PL_in_eval & ~0x7F));                                  \
750         assert(!(PL_op->op_type & ~0x1FF));                             \
751         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
752         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
753         cx->blk_eval.old_eval_root = PL_eval_root;                      \
754         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
755         cx->blk_eval.cv = NULL; /* set by doeval_compile() as applicable */ \
756         cx->blk_eval.retop = NULL;                                      \
757         cx->blk_eval.cur_top_env = PL_top_env;                          \
758     } STMT_END
759
760 #define POPEVAL(cx)                                                     \
761     STMT_START {                                                        \
762         SV *sv;                                                         \
763         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
764         PL_eval_root = cx->blk_eval.old_eval_root;                      \
765         sv = cx->blk_eval.cur_text;                                     \
766         if (sv && SvSCREAM(sv)) {                                       \
767             cx->blk_eval.cur_text = NULL;                               \
768             SvREFCNT_dec_NN(sv);                                        \
769         }                                                               \
770         sv = cx->blk_eval.old_namesv;                                   \
771         if (sv && !SvTEMP(sv))/* TEMP => POPEVAL re-entrantly called */ \
772             sv_2mortal(sv);                                             \
773     } STMT_END
774
775 /* loop context */
776 struct block_loop {
777     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
778     union {     /* different ways of locating the iteration variable */
779         SV      **svp; /* for lexicals: address of pad slot */
780         GV      *gv;   /* for package vars */
781     } itervar_u;
782     SV          *itersave; /* the original iteration var */
783     union {
784         struct { /* CXt_LOOP_ARY, C<for (@ary)>  */
785             AV *ary; /* array being iterated over */
786             IV  ix;   /* index relative to base of array */
787         } ary;
788         struct { /* CXt_LOOP_LIST, C<for (list)> */
789             I32 basesp; /* first element of list on stack */
790             IV  ix;      /* index relative to basesp */
791         } stack;
792         struct { /* CXt_LOOP_LAZYIV, C<for (1..9)> */
793             IV cur;
794             IV end;
795         } lazyiv;
796         struct { /* CXt_LOOP_LAZYSV C<for ('a'..'z')> */
797             SV * cur;
798             SV * end; /* maxiumum value (or minimum in reverse) */
799         } lazysv;
800     } state_u;
801 #ifdef USE_ITHREADS
802     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
803 #endif
804 };
805
806 #define CxITERVAR(c)                                    \
807         (CxPADLOOP(c)                                   \
808             ? (c)->blk_loop.itervar_u.svp               \
809             : ((c)->cx_type & CXp_FOR_GV)               \
810                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
811                 : (SV **)&(c)->blk_loop.itervar_u.gv)
812
813 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
814 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
815 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
816 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
817 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
818
819
820 #define PUSHLOOP_PLAIN(cx)                                              \
821         cx->blk_loop.my_op = cLOOP;                                     \
822         cx->blk_oldsaveix = PL_savestack_ix;
823
824 #ifdef USE_ITHREADS
825 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
826 #else
827 #  define PUSHLOOP_FOR_setpad(c) NOOP
828 #endif
829
830 #define PUSHLOOP_FOR(cx, ivar, isave)                                   \
831         cx->blk_loop.my_op = cLOOP;                                     \
832         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
833         cx->blk_oldsaveix = PL_savestack_ix;                                \
834         cx->blk_loop.itersave = isave;                                  \
835         PUSHLOOP_FOR_setpad(cx);
836
837 #define POPLOOP(cx)                                                     \
838         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
839             SV *sv = cx->blk_loop.state_u.lazysv.cur;                   \
840             cx->blk_loop.state_u.lazysv.cur = NULL;                     \
841             SvREFCNT_dec_NN(sv);                                        \
842             sv = cx->blk_loop.state_u.lazysv.end;                       \
843             cx->blk_loop.state_u.lazysv.end = NULL;                     \
844             SvREFCNT_dec_NN(sv);                                        \
845         }                                                               \
846         else if (CxTYPE(cx) == CXt_LOOP_ARY) {                          \
847             AV *av = cx->blk_loop.state_u.ary.ary;                      \
848             cx->blk_loop.state_u.ary.ary = NULL;                        \
849             SvREFCNT_dec(av);                                           \
850         }                                                               \
851         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
852             SV *cursv;                                                  \
853             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
854             if ((cx->cx_type & CXp_FOR_GV))                             \
855                 svp = &GvSV((GV*)svp);                                  \
856             cursv = *svp;                                               \
857             *svp = cx->blk_loop.itersave;                               \
858             cx->blk_loop.itersave = NULL;                               \
859             SvREFCNT_dec(cursv);                                        \
860         }
861
862 /* given/when context */
863 struct block_givwhen {
864         OP *leave_op;
865         SV *defsv_save; /* the original $_ */
866 };
867
868 #define PUSHWHEN(cx)                                                    \
869         cx->blk_oldsaveix = PL_savestack_ix;                            \
870         cx->blk_givwhen.leave_op = cLOGOP->op_other;
871
872 #define PUSHGIVEN(cx, orig_var)                                         \
873         PUSHWHEN(cx);                                                   \
874         cx->blk_givwhen.defsv_save = orig_var;
875
876 #define POPWHEN(cx)                                                     \
877         NOOP;
878
879 #define POPGIVEN(cx)                                                    \
880     STMT_START {                                                        \
881         SV *sv = GvSV(PL_defgv);                                        \
882         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;                    \
883         cx->blk_givwhen.defsv_save = NULL;                              \
884         SvREFCNT_dec(sv);                                               \
885     } STMT_END
886
887
888 /* basic block, i.e. pp_enter/leave */
889
890 #define PUSHBASICBLK(cx)                                                \
891         cx->blk_oldsaveix = PL_savestack_ix;
892
893 #define POPBASICBLK(cx)                                                 \
894         NOOP;
895
896
897 /* context common to subroutines, evals and loops */
898 struct block {
899     U8          blku_type;      /* what kind of context this is */
900     U8          blku_gimme;     /* is this block running in list context? */
901     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
902     I32         blku_oldsaveix; /* saved PL_savestack_ix */
903     /* all the fields above must be aligned with same-sized fields as sbu */
904     I32         blku_oldsp;     /* current sp floor: where nextstate pops to */
905     I32         blku_oldmarksp; /* mark stack index */
906     COP *       blku_oldcop;    /* old curcop pointer */
907     PMOP *      blku_oldpm;     /* values of pattern match vars */
908     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
909     I32         blku_oldscopesp;        /* scope stack index */
910
911     union {
912         struct block_sub        blku_sub;
913         struct block_format     blku_format;
914         struct block_eval       blku_eval;
915         struct block_loop       blku_loop;
916         struct block_givwhen    blku_givwhen;
917     } blk_u;
918 };
919 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
920 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
921 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
922 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
923 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
924 #define blk_gimme       cx_u.cx_blk.blku_gimme
925 #define blk_u16         cx_u.cx_blk.blku_u16
926 #define blk_oldsaveix   cx_u.cx_blk.blku_oldsaveix
927 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
928 #define blk_format      cx_u.cx_blk.blk_u.blku_format
929 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
930 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
931 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
932
933 #define CX_DEBUG(cx, action)                                            \
934     DEBUG_l(                                                            \
935         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
936                     (long)cxstack_ix,                                   \
937                     action,                                             \
938                     PL_block_type[CxTYPE(cx)],                          \
939                     (long)PL_scopestack_ix,                             \
940                     (long)(cx->blk_oldscopesp),                         \
941                     (long)PL_savestack_ix,                              \
942                     (long)(cx->blk_oldsaveix),                          \
943                     __FILE__, __LINE__));
944
945 /* Enter a block. */
946 #define PUSHBLOCK(cx,t,sp) CXINC, cx = CX_CUR(),                        \
947         cx->cx_type             = t,                                    \
948         cx->blk_oldsp           = sp - PL_stack_base,                   \
949         cx->blk_oldcop          = PL_curcop,                            \
950         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
951         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
952         cx->blk_oldpm           = PL_curpm,                             \
953         cx->blk_gimme           = (U8)gimme;                            \
954         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
955         PL_tmps_floor           = PL_tmps_ix;                           \
956         CX_DEBUG(cx, "PUSH");
957
958 /* Exit a block (RETURN and LAST). */
959 #define POPBLOCK(cx)                                                    \
960         CX_DEBUG(cx, "POP");                                            \
961         PL_curcop        = cx->blk_oldcop,                              \
962         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
963         PL_scopestack_ix = cx->blk_oldscopesp,                          \
964         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
965          * and leaves a CX entry lying around for repeated use, so
966          * skip for multicall */                  \
967         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
968                 || PL_savestack_ix == cx->blk_oldsaveix);               \
969         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
970         PL_curpm         = cx->blk_oldpm;
971
972 /* Continue a block elsewhere (e.g. NEXT, REDO, GOTO). */
973 #define TOPBLOCK(cx)                                                    \
974         CX_DEBUG(cx, "TOP");                                            \
975         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
976         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
977         PL_scopestack_ix = cx->blk_oldscopesp,                          \
978         PL_curpm         = cx->blk_oldpm;
979
980 /* substitution context */
981 struct subst {
982     U8          sbu_type;       /* same as blku_type */
983     U8          sbu_rflags;
984     U16         sbu_rxtainted;
985     I32         sbu_oldsaveix; /* same as blku_oldsaveix */
986     /* all the fields above must be aligned with same-sized fields as blku * */
987     SSize_t     sbu_iters;
988     SSize_t     sbu_maxiters;
989     char *      sbu_orig;
990     SV *        sbu_dstr;
991     SV *        sbu_targ;
992     char *      sbu_s;
993     char *      sbu_m;
994     char *      sbu_strend;
995     void *      sbu_rxres;
996     REGEXP *    sbu_rx;
997 };
998 #define sb_iters        cx_u.cx_subst.sbu_iters
999 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
1000 #define sb_rflags       cx_u.cx_subst.sbu_rflags
1001 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
1002 #define sb_orig         cx_u.cx_subst.sbu_orig
1003 #define sb_dstr         cx_u.cx_subst.sbu_dstr
1004 #define sb_targ         cx_u.cx_subst.sbu_targ
1005 #define sb_s            cx_u.cx_subst.sbu_s
1006 #define sb_m            cx_u.cx_subst.sbu_m
1007 #define sb_strend       cx_u.cx_subst.sbu_strend
1008 #define sb_rxres        cx_u.cx_subst.sbu_rxres
1009 #define sb_rx           cx_u.cx_subst.sbu_rx
1010
1011 #ifdef PERL_CORE
1012 #  define PUSHSUBST(cx) CXINC, cx = CX_CUR(),                           \
1013         cx->blk_oldsaveix = oldsave,                                    \
1014         cx->sb_iters            = iters,                                \
1015         cx->sb_maxiters         = maxiters,                             \
1016         cx->sb_rflags           = r_flags,                              \
1017         cx->sb_rxtainted        = rxtainted,                            \
1018         cx->sb_orig             = orig,                                 \
1019         cx->sb_dstr             = dstr,                                 \
1020         cx->sb_targ             = targ,                                 \
1021         cx->sb_s                = s,                                    \
1022         cx->sb_m                = m,                                    \
1023         cx->sb_strend           = strend,                               \
1024         cx->sb_rxres            = NULL,                                 \
1025         cx->sb_rx               = rx,                                   \
1026         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1027         rxres_save(&cx->sb_rxres, rx);                                  \
1028         (void)ReREFCNT_inc(rx);                                         \
1029         SvREFCNT_inc_void_NN(targ)
1030
1031 #  define POPSUBST(cx) \
1032     STMT_START {                                                        \
1033         REGEXP *re;                                                     \
1034         rxres_free(&cx->sb_rxres);                                      \
1035         re = cx->sb_rx;                                                 \
1036         cx->sb_rx = NULL;                                               \
1037         ReREFCNT_dec(re);                                               \
1038         SvREFCNT_dec_NN(cx->sb_targ);                                   \
1039     } STMT_END
1040 #endif
1041
1042 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1043
1044 struct context {
1045     union {
1046         struct block    cx_blk;
1047         struct subst    cx_subst;
1048     } cx_u;
1049 };
1050 #define cx_type cx_u.cx_subst.sbu_type
1051
1052 /* If you re-order these, there is also an array of uppercase names in perl.h
1053    and a static array of context names in pp_ctl.c  */
1054 #define CXTYPEMASK      0xf
1055 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1056 #define CXt_WHEN        1
1057 #define CXt_BLOCK       2
1058 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1059    jump table in pp_ctl.c
1060    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1061 */
1062 #define CXt_GIVEN       3
1063
1064 /* be careful of the ordering of these five. Macros like CxTYPE_is_LOOP,
1065  * CxFOREACH compare ranges */
1066 #define CXt_LOOP_PLAIN  4 /*                {} */
1067 #define CXt_LOOP_LAZYIV 5 /* for (1..9)     {} */
1068 #define CXt_LOOP_LAZYSV 6 /* for ('a'..'z') {} */
1069 #define CXt_LOOP_LIST   7 /* for (1,2,3)    {} */
1070 #define CXt_LOOP_ARY    8 /* for (@ary)     {} */
1071
1072 #define CXt_SUB         9
1073 #define CXt_FORMAT     10
1074 #define CXt_EVAL       11
1075 #define CXt_SUBST      12
1076 /* SUBST doesn't feature in all switch statements.  */
1077
1078 /* private flags for CXt_SUB and CXt_FORMAT */
1079 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1080                                    context on exit). (not CXt_FORMAT) */
1081 #define CXp_HASARGS     0x20
1082 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1083 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1084
1085 /* private flags for CXt_EVAL */
1086 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1087 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1088
1089 /* private flags for CXt_LOOP */
1090 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1091 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1092 #define CXp_FOR_GV      0x40    /* foreach using package var */
1093 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1094 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1095
1096 /* private flags for CXt_SUBST */
1097 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1098
1099 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1100 #define CxTYPE_is_LOOP(c) (   CxTYPE(cx) >= CXt_LOOP_PLAIN              \
1101                            && CxTYPE(cx) <= CXt_LOOP_ARY)
1102 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1103 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1104                          == (CXt_EVAL|CXp_REAL))
1105 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1106                          == (CXt_EVAL|CXp_TRYBLOCK))
1107 #define CxFOREACH(c)    (   CxTYPE(cx) >= CXt_LOOP_LAZYSV               \
1108                          && CxTYPE(cx) <= CXt_LOOP_ARY)
1109
1110 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1111
1112 /* 
1113 =head1 "Gimme" Values
1114 */
1115
1116 /*
1117 =for apidoc AmU||G_SCALAR
1118 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1119 L<perlcall>.
1120
1121 =for apidoc AmU||G_ARRAY
1122 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1123 L<perlcall>.
1124
1125 =for apidoc AmU||G_VOID
1126 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1127
1128 =for apidoc AmU||G_DISCARD
1129 Indicates that arguments returned from a callback should be discarded.  See
1130 L<perlcall>.
1131
1132 =for apidoc AmU||G_EVAL
1133
1134 Used to force a Perl C<eval> wrapper around a callback.  See
1135 L<perlcall>.
1136
1137 =for apidoc AmU||G_NOARGS
1138
1139 Indicates that no arguments are being sent to a callback.  See
1140 L<perlcall>.
1141
1142 =cut
1143 */
1144
1145 #define G_SCALAR        2
1146 #define G_ARRAY         3
1147 #define G_VOID          1
1148 #define G_WANT          3
1149
1150 /* extra flags for Perl_call_* routines */
1151 #define G_DISCARD       4       /* Call FREETMPS.
1152                                    Don't change this without consulting the
1153                                    hash actions codes defined in hv.h */
1154 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1155 #define G_NOARGS       16       /* Don't construct a @_ array. */
1156 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1157 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1158 #define G_METHOD      128       /* Calling method. */
1159 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1160                                    fold_constants. */
1161 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1162                                    A special case for UNSHIFT in
1163                                    Perl_magic_methcall().  */
1164 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1165                                     Perl_magic_methcall().  */
1166 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1167 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1168
1169 /* flag bits for PL_in_eval */
1170 #define EVAL_NULL       0       /* not in an eval */
1171 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1172 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1173 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1174 #define EVAL_INREQUIRE  8       /* The code is being required. */
1175 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1176
1177 /* Support for switching (stack and block) contexts.
1178  * This ensures magic doesn't invalidate local stack and cx pointers.
1179  */
1180
1181 #define PERLSI_UNKNOWN          -1
1182 #define PERLSI_UNDEF            0
1183 #define PERLSI_MAIN             1
1184 #define PERLSI_MAGIC            2
1185 #define PERLSI_SORT             3
1186 #define PERLSI_SIGNAL           4
1187 #define PERLSI_OVERLOAD         5
1188 #define PERLSI_DESTROY          6
1189 #define PERLSI_WARNHOOK         7
1190 #define PERLSI_DIEHOOK          8
1191 #define PERLSI_REQUIRE          9
1192 #define PERLSI_MULTICALL       10
1193
1194 struct stackinfo {
1195     AV *                si_stack;       /* stack for current runlevel */
1196     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1197     struct stackinfo *  si_prev;
1198     struct stackinfo *  si_next;
1199     I32                 si_cxix;        /* current context index */
1200     I32                 si_cxmax;       /* maximum allocated index */
1201     I32                 si_type;        /* type of runlevel */
1202     I32                 si_markoff;     /* offset where markstack begins for us.
1203                                          * currently used only with DEBUGGING,
1204                                          * but not #ifdef-ed for bincompat */
1205 };
1206
1207 typedef struct stackinfo PERL_SI;
1208
1209 #define cxstack         (PL_curstackinfo->si_cxstack)
1210 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1211 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1212
1213 #ifdef DEBUGGING
1214 #  define       SET_MARK_OFFSET \
1215     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1216 #else
1217 #  define       SET_MARK_OFFSET NOOP
1218 #endif
1219
1220 #define PUSHSTACKi(type) \
1221     STMT_START {                                                        \
1222         PERL_SI *next = PL_curstackinfo->si_next;                       \
1223         DEBUG_l({                                                       \
1224             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1225             while (p) { i++; p = p->si_prev; }                          \
1226             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1227                          i, __FILE__, __LINE__);})                      \
1228         if (!next) {                                                    \
1229             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1230             next->si_prev = PL_curstackinfo;                            \
1231             PL_curstackinfo->si_next = next;                            \
1232         }                                                               \
1233         next->si_type = type;                                           \
1234         next->si_cxix = -1;                                             \
1235         AvFILLp(next->si_stack) = 0;                                    \
1236         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1237         PL_curstackinfo = next;                                         \
1238         SET_MARK_OFFSET;                                                \
1239     } STMT_END
1240
1241 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1242
1243 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1244  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1245 #define POPSTACK \
1246     STMT_START {                                                        \
1247         dSP;                                                            \
1248         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1249         DEBUG_l({                                                       \
1250             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1251             while (p) { i++; p = p->si_prev; }                          \
1252             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1253                          i, __FILE__, __LINE__);})                      \
1254         if (!prev) {                                                    \
1255             Perl_croak_popstack();                                      \
1256         }                                                               \
1257         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1258         /* don't free prev here, free them all at the END{} */          \
1259         PL_curstackinfo = prev;                                         \
1260     } STMT_END
1261
1262 #define POPSTACK_TO(s) \
1263     STMT_START {                                                        \
1264         while (PL_curstack != s) {                                      \
1265             dounwind(-1);                                               \
1266             POPSTACK;                                                   \
1267         }                                                               \
1268     } STMT_END
1269
1270 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1271 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1272
1273 /*
1274 =head1 Multicall Functions
1275
1276 =for apidoc Ams||dMULTICALL
1277 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1278
1279 =for apidoc Ams||PUSH_MULTICALL
1280 Opening bracket for a lightweight callback.
1281 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1282
1283 =for apidoc Ams||MULTICALL
1284 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1285
1286 =for apidoc Ams||POP_MULTICALL
1287 Closing bracket for a lightweight callback.
1288 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1289
1290 =cut
1291 */
1292
1293 #define dMULTICALL \
1294     SV **newsp;                 /* set by POPBLOCK */                   \
1295     PERL_CONTEXT *cx;                                                   \
1296     CV *multicall_cv;                                                   \
1297     OP *multicall_cop;                                                  \
1298     bool multicall_oldcatch;                                            \
1299     U8 hasargs = 0              /* used by PUSHSUB */
1300
1301 #define PUSH_MULTICALL(the_cv) \
1302     PUSH_MULTICALL_FLAGS(the_cv, 0)
1303
1304 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1305  * for the CX stack entry (this isn't part of the public API) */
1306
1307 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1308     STMT_START {                                                        \
1309         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1310         CV * const cv = _nOnclAshIngNamE_;                              \
1311         PADLIST * const padlist = CvPADLIST(cv);                        \
1312         multicall_oldcatch = CATCH_GET;                                 \
1313         CATCH_SET(TRUE);                                                \
1314         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1315         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1316         PUSHSUB(cx);                                                    \
1317         cx->blk_oldsaveix = PL_savestack_ix;                            \
1318         SAVEVPTR(PL_op);                                                \
1319         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1320             CvDEPTH(cv)++;                                              \
1321         if (CvDEPTH(cv) >= 2) {                                         \
1322             PERL_STACK_OVERFLOW_CHECK();                                \
1323             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1324         }                                                               \
1325         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1326         multicall_cv = cv;                                              \
1327         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1328         multicall_cop = CvSTART(cv);                                    \
1329     } STMT_END
1330
1331 #define MULTICALL \
1332     STMT_START {                                                        \
1333         PL_op = multicall_cop;                                          \
1334         CALLRUNOPS(aTHX);                                               \
1335     } STMT_END
1336
1337 #define POP_MULTICALL \
1338     STMT_START {                                                        \
1339         cx = CX_CUR();                                                  \
1340         CX_LEAVE_SCOPE(cx);                                             \
1341         POPSUB_COMMON(cx);                                              \
1342         newsp = PL_stack_base + cx->blk_oldsp;                          \
1343         gimme = cx->blk_gimme;                                          \
1344         PERL_UNUSED_VAR(newsp); /* for API */                           \
1345         PERL_UNUSED_VAR(gimme); /* for API */                           \
1346         POPBLOCK(cx);                                                   \
1347         CX_POP(cx);                                                     \
1348         POPSTACK;                                                       \
1349         CATCH_SET(multicall_oldcatch);                                  \
1350         SPAGAIN;                                                        \
1351     } STMT_END
1352
1353 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1354  * (this isn't part of the public API) */
1355
1356 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1357     STMT_START {                                                        \
1358         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1359         CV * const cv = _nOnclAshIngNamE_;                              \
1360         PADLIST * const padlist = CvPADLIST(cv);                        \
1361         cx = CX_CUR();                                                  \
1362         assert(CxMULTICALL(cx));                                        \
1363         POPSUB_COMMON(cx);                                              \
1364         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1365         PUSHSUB(cx);                                                    \
1366         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1367             CvDEPTH(cv)++;                                              \
1368         if (CvDEPTH(cv) >= 2) {                                         \
1369             PERL_STACK_OVERFLOW_CHECK();                                \
1370             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1371         }                                                               \
1372         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1373         multicall_cv = cv;                                              \
1374         multicall_cop = CvSTART(cv);                                    \
1375     } STMT_END
1376 /*
1377  * ex: set ts=8 sts=4 sw=4 et:
1378  */