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