This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
make PL_tmps_floor restore consistent
[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) \
576     LEAVE_SCOPE(cx->cx_u.cx_blk.blku_old_savestack_ix)
577
578 /* base for the next two macros. Don't use directly.
579  * The context frame holds a reference to the CV so that it can't be
580  * freed while we're executing it */
581
582 #define PUSHSUB_BASE(cx)                                                \
583         ENTRY_PROBE(CvNAMED(cv)                                         \
584                         ? HEK_KEY(CvNAME_HEK(cv))                       \
585                         : GvENAME(CvGV(cv)),                            \
586                 CopFILE((const COP *)CvSTART(cv)),                      \
587                 CopLINE((const COP *)CvSTART(cv)),                      \
588                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
589                                                                         \
590         cx->blk_sub.cv = cv;                                            \
591         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
592         cx->blk_sub.prevcomppad = PL_comppad;                           \
593         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
594         cx->blk_sub.retop = NULL;                                       \
595         SvREFCNT_inc_simple_void_NN(cv);                                \
596         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
597         PL_tmps_floor = PL_tmps_ix;
598
599 #define PUSHSUB_GET_LVALUE_MASK(func) \
600         /* If the context is indeterminate, then only the lvalue */     \
601         /* flags that the caller also has are applicable.        */     \
602         (                                                               \
603            (PL_op->op_flags & OPf_WANT)                                 \
604                ? OPpENTERSUB_LVAL_MASK                                  \
605                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
606                    ? 0 : (U8)func(aTHX)                                 \
607         )
608
609 #define PUSHSUB(cx)                                                     \
610     {                                                                   \
611         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
612         PUSHSUB_BASE(cx)                                                \
613         cx->blk_u16 = PL_op->op_private &                               \
614                           (phlags|OPpDEREF);                            \
615     }
616
617 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
618 #define PUSHSUB_DB(cx)                                                  \
619         PUSHSUB_BASE(cx)                                                \
620         cx->blk_u16 = 0;
621
622
623 #define PUSHFORMAT(cx, retop)                                           \
624         cx->blk_format.cv = cv;                                         \
625         cx->blk_format.gv = gv;                                         \
626         cx->blk_format.retop = (retop);                                 \
627         cx->blk_format.dfoutgv = PL_defoutgv;                           \
628         cx->blk_format.prevcomppad = PL_comppad;                        \
629         cx->blk_u16 = 0;                                                \
630         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
631         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
632         PL_tmps_floor = PL_tmps_ix;                                     \
633         SvREFCNT_inc_simple_void_NN(cv);                                \
634         CvDEPTH(cv)++;                                                  \
635         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
636
637 /* Restore old @_ */
638 #define POP_SAVEARRAY()                                         \
639     STMT_START {                                                        \
640         AV *av = GvAV(PL_defgv);                                        \
641         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
642         SvREFCNT_dec(av);                                               \
643     } STMT_END
644
645 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
646  * leave any (a fast av_clear(ary), basically) */
647 #define CLEAR_ARGARRAY(ary) \
648     STMT_START {                                                        \
649         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
650         AvARRAY(ary) = AvALLOC(ary);                                    \
651         AvFILLp(ary) = -1;                                              \
652     } STMT_END
653
654 #define POPSUB(cx)                                                      \
655     STMT_START {                                                        \
656         CX_LEAVE_SCOPE(cx);                                             \
657         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
658         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
659         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
660                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
661                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
662                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
663                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
664                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
665                                                                         \
666         if (CxHASARGS(cx)) {                                            \
667             AV *av;                                                     \
668             assert(AvARRAY(MUTABLE_AV(                                  \
669                 PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                \
670                         CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);       \
671             POP_SAVEARRAY();                                            \
672             /* abandon @_ if it got reified */                          \
673             av = MUTABLE_AV(PAD_SVl(0));                                \
674             if (UNLIKELY(AvREAL(av)))                                   \
675                 clear_defarray(av, 0);                                  \
676             else {                                                      \
677                 CLEAR_ARGARRAY(av);                                     \
678             }                                                           \
679         }                                                               \
680         }                                                               \
681         PL_comppad = cx->blk_sub.prevcomppad;                           \
682         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
683         CvDEPTH((const CV*)cx->blk_sub.cv) = cx->blk_sub.olddepth;      \
684         SvREFCNT_dec_NN(cx->blk_sub.cv);                                \
685         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
686     } STMT_END
687
688 #define POPFORMAT(cx)                                                   \
689     STMT_START {                                                        \
690         CX_LEAVE_SCOPE(cx);                                             \
691         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
692         CV * const cv = cx->blk_format.cv;                              \
693         GV * const dfuot = cx->blk_format.dfoutgv;                      \
694         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
695         setdefout(dfuot);                                               \
696         PL_comppad = cx->blk_format.prevcomppad;                        \
697         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
698         --CvDEPTH(cv);                                                  \
699         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
700         SvREFCNT_dec_NN(dfuot);                                         \
701         }                                                               \
702         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
703     } STMT_END
704
705 /* eval context */
706 struct block_eval {
707     OP *        retop;  /* op to execute on exit from eval */
708     /* Above here is the same for sub, format and eval.  */
709     SV *        old_namesv;
710     OP *        old_eval_root;
711     SV *        cur_text;
712     CV *        cv;
713     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
714 };
715
716 /* If we ever need more than 512 op types, change the shift from 7.
717    blku_gimme is actually also only 2 bits, so could be merged with something.
718 */
719
720 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
721 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
722
723 #define PUSHEVAL(cx,n)                                                  \
724     STMT_START {                                                        \
725         assert(!(PL_in_eval & ~0x7F));                                  \
726         assert(!(PL_op->op_type & ~0x1FF));                             \
727         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
728         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
729         PL_tmps_floor = PL_tmps_ix;                                     \
730         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
731         cx->blk_eval.old_eval_root = PL_eval_root;                      \
732         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
733         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
734         cx->blk_eval.retop = NULL;                                      \
735         cx->blk_eval.cur_top_env = PL_top_env;                          \
736     } STMT_END
737
738 #define POPEVAL(cx)                                                     \
739     STMT_START {                                                        \
740         CX_LEAVE_SCOPE(cx);                                             \
741         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
742         optype = CxOLD_OP_TYPE(cx);                                     \
743         PL_eval_root = cx->blk_eval.old_eval_root;                      \
744         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
745             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
746         if (cx->blk_eval.old_namesv)                                    \
747             sv_2mortal(cx->blk_eval.old_namesv);                        \
748         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
749     } STMT_END
750
751 /* loop context */
752 struct block_loop {
753     I32         resetsp;
754     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
755     union {     /* different ways of locating the iteration variable */
756         SV      **svp; /* for lexicals: address of pad slot */
757         GV      *gv;   /* for package vars */
758     } itervar_u;
759     SV          *itersave; /* the original iteration var */
760     union {
761         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
762             AV * ary; /* use the stack if this is NULL */
763             IV ix;
764         } ary;
765         struct { /* valid if type is LOOP_LAZYIV */
766             IV cur;
767             IV end;
768         } lazyiv;
769         struct { /* valid if type if LOOP_LAZYSV */
770             SV * cur;
771             SV * end; /* maxiumum value (or minimum in reverse) */
772         } lazysv;
773     } state_u;
774 #ifdef USE_ITHREADS
775     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
776 #endif
777 };
778
779 #define CxITERVAR(c)                                    \
780         (CxPADLOOP(c)                                   \
781             ? (c)->blk_loop.itervar_u.svp               \
782             : ((c)->cx_type & CXp_FOR_GV)               \
783                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
784                 : (SV **)&(c)->blk_loop.itervar_u.gv)
785
786 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
787 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
788 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
789 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
790 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
791 /* POPSUB has already been performed on this context frame */
792 #define CxPOPSUB_DONE 0x100
793
794
795 #define PUSHLOOP_PLAIN(cx, s)                                           \
796         cx->blk_loop.resetsp = s - PL_stack_base;                       \
797         cx->blk_loop.my_op = cLOOP;                                     \
798         cx->blk_loop.state_u.ary.ary = NULL;                            \
799         cx->blk_loop.state_u.ary.ix = 0;                                \
800         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
801         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
802         PL_tmps_floor = PL_tmps_ix;                                     \
803         cx->blk_loop.itervar_u.svp = NULL;                              \
804         cx->blk_loop.itersave = NULL;
805
806 #ifdef USE_ITHREADS
807 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
808 #else
809 #  define PUSHLOOP_FOR_setpad(c) NOOP
810 #endif
811
812 #define PUSHLOOP_FOR(cx, ivar, isave, s)                                \
813         cx->blk_loop.resetsp = s - PL_stack_base;                       \
814         cx->blk_loop.my_op = cLOOP;                                     \
815         cx->blk_loop.state_u.ary.ary = NULL;                            \
816         cx->blk_loop.state_u.ary.ix = 0;                                \
817         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
818         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
819         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
820         PL_tmps_floor = PL_tmps_ix;                                     \
821         cx->blk_loop.itersave = isave;                                  \
822         PUSHLOOP_FOR_setpad(cx);
823
824 #define POPLOOP(cx)                                                     \
825         CX_LEAVE_SCOPE(cx);                                             \
826         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
827             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
828             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
829         }                                                               \
830         else if (CxTYPE(cx) == CXt_LOOP_FOR)                            \
831             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
832         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
833             SV *cursv;                                                  \
834             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
835             if ((cx->cx_type & CXp_FOR_GV))                             \
836                 svp = &GvSV((GV*)svp);                                  \
837             cursv = *svp;                                               \
838             *svp = cx->blk_loop.itersave;                               \
839             SvREFCNT_dec(cursv);                                        \
840         }                                                               \
841         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
842
843 /* given/when context */
844 struct block_givwhen {
845         OP *leave_op;
846         SV *defsv_save; /* the original $_ */
847 };
848
849 #define PUSHWHEN(cx)                                                    \
850         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
851         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
852         PL_tmps_floor = PL_tmps_ix;                                     \
853         cx->blk_givwhen.leave_op = cLOGOP->op_other;
854
855 #define PUSHGIVEN(cx, orig_var)                                         \
856         PUSHWHEN(cx);                                                   \
857         cx->blk_givwhen.defsv_save = orig_var;
858
859 #define POPWHEN(cx)                                                     \
860         CX_LEAVE_SCOPE(cx);                                             \
861         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
862
863 #define POPGIVEN(cx)                                                    \
864         CX_LEAVE_SCOPE(cx);                                             \
865         SvREFCNT_dec(GvSV(PL_defgv));                                   \
866         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;                    \
867         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
868
869
870 /* basic block, i.e. pp_enter/leave */
871
872 #define PUSHBASICBLK(cx)                                                \
873         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
874         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
875         PL_tmps_floor = PL_tmps_ix;
876
877 #define POPBASICBLK(cx)                                                 \
878         CX_LEAVE_SCOPE(cx);                                             \
879         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
880
881
882 /* context common to subroutines, evals and loops */
883 struct block {
884     U8          blku_type;      /* what kind of context this is */
885     U8          blku_gimme;     /* is this block running in list context? */
886     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
887     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
888     COP *       blku_oldcop;    /* old curcop pointer */
889     I32         blku_oldmarksp; /* mark stack index */
890     I32         blku_oldscopesp;        /* scope stack index */
891     PMOP *      blku_oldpm;     /* values of pattern match vars */
892     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
893     I32         blku_old_savestack_ix;  /* saved PL_savestack_ix */
894
895     union {
896         struct block_sub        blku_sub;
897         struct block_format     blku_format;
898         struct block_eval       blku_eval;
899         struct block_loop       blku_loop;
900         struct block_givwhen    blku_givwhen;
901     } blk_u;
902 };
903 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
904 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
905 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
906 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
907 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
908 #define blk_gimme       cx_u.cx_blk.blku_gimme
909 #define blk_u16         cx_u.cx_blk.blku_u16
910 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
911 #define blk_format      cx_u.cx_blk.blk_u.blku_format
912 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
913 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
914 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
915
916 #define DEBUG_CX(action)                                                \
917     DEBUG_l(                                                            \
918         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
919                     (long)cxstack_ix,                                   \
920                     action,                                             \
921                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
922                     (long)PL_scopestack_ix,                             \
923                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
924                     (long)PL_savestack_ix,                              \
925                     (long)(cxstack[cxstack_ix].cx_u.cx_blk.blku_old_savestack_ix),\
926                     __FILE__, __LINE__));
927
928 /* Enter a block. */
929 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
930         cx->cx_type             = t,                                    \
931         cx->blk_oldsp           = sp - PL_stack_base,                   \
932         cx->blk_oldcop          = PL_curcop,                            \
933         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
934         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
935         cx->blk_oldpm           = PL_curpm,                             \
936         cx->blk_gimme           = (U8)gimme;                            \
937         DEBUG_CX("PUSH");
938
939 /* Exit a block (RETURN and LAST). */
940 #define POPBLOCK(cx,pm)                                                 \
941         DEBUG_CX("POP");                                                \
942         cx = &cxstack[cxstack_ix--],                                    \
943         PL_curcop        = cx->blk_oldcop,                              \
944         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
945         PL_scopestack_ix = cx->blk_oldscopesp,                          \
946         pm               = cx->blk_oldpm;
947
948 /* Continue a block elsewhere (NEXT and REDO). */
949 #define TOPBLOCK(cx)                                                    \
950         DEBUG_CX("TOP");                                                \
951         cx  = &cxstack[cxstack_ix],                                     \
952         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
953         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
954         PL_scopestack_ix = cx->blk_oldscopesp,                          \
955         PL_curpm         = cx->blk_oldpm;
956
957 /* substitution context */
958 struct subst {
959     U8          sbu_type;       /* what kind of context this is */
960     U8          sbu_rflags;
961     U16         sbu_rxtainted;  /* matches struct block */
962     I32         sbu_oldsave;
963     SSize_t     sbu_iters;
964     SSize_t     sbu_maxiters;
965     char *      sbu_orig;
966     SV *        sbu_dstr;
967     SV *        sbu_targ;
968     char *      sbu_s;
969     char *      sbu_m;
970     char *      sbu_strend;
971     void *      sbu_rxres;
972     REGEXP *    sbu_rx;
973 };
974 #define sb_iters        cx_u.cx_subst.sbu_iters
975 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
976 #define sb_rflags       cx_u.cx_subst.sbu_rflags
977 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
978 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
979 #define sb_orig         cx_u.cx_subst.sbu_orig
980 #define sb_dstr         cx_u.cx_subst.sbu_dstr
981 #define sb_targ         cx_u.cx_subst.sbu_targ
982 #define sb_s            cx_u.cx_subst.sbu_s
983 #define sb_m            cx_u.cx_subst.sbu_m
984 #define sb_strend       cx_u.cx_subst.sbu_strend
985 #define sb_rxres        cx_u.cx_subst.sbu_rxres
986 #define sb_rx           cx_u.cx_subst.sbu_rx
987
988 #ifdef PERL_CORE
989 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
990         cx->sb_iters            = iters,                                \
991         cx->sb_maxiters         = maxiters,                             \
992         cx->sb_rflags           = r_flags,                              \
993         cx->sb_oldsave          = oldsave,                              \
994         cx->sb_rxtainted        = rxtainted,                            \
995         cx->sb_orig             = orig,                                 \
996         cx->sb_dstr             = dstr,                                 \
997         cx->sb_targ             = targ,                                 \
998         cx->sb_s                = s,                                    \
999         cx->sb_m                = m,                                    \
1000         cx->sb_strend           = strend,                               \
1001         cx->sb_rxres            = NULL,                                 \
1002         cx->sb_rx               = rx,                                   \
1003         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1004         rxres_save(&cx->sb_rxres, rx);                                  \
1005         (void)ReREFCNT_inc(rx);                                         \
1006         SvREFCNT_inc_void_NN(targ)
1007
1008 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
1009         rxres_free(&cx->sb_rxres);                                      \
1010         ReREFCNT_dec(cx->sb_rx);                                        \
1011         SvREFCNT_dec_NN(cx->sb_targ)
1012 #endif
1013
1014 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1015
1016 struct context {
1017     union {
1018         struct block    cx_blk;
1019         struct subst    cx_subst;
1020     } cx_u;
1021 };
1022 #define cx_type cx_u.cx_subst.sbu_type
1023
1024 /* If you re-order these, there is also an array of uppercase names in perl.h
1025    and a static array of context names in pp_ctl.c  */
1026 #define CXTYPEMASK      0xf
1027 #define CXt_NULL        0
1028 #define CXt_WHEN        1
1029 #define CXt_BLOCK       2
1030 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1031    jump table in pp_ctl.c
1032    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1033 */
1034 #define CXt_GIVEN       3
1035 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
1036 #define CXt_LOOP_FOR    4
1037 #define CXt_LOOP_PLAIN  5
1038 #define CXt_LOOP_LAZYSV 6
1039 #define CXt_LOOP_LAZYIV 7
1040 #define CXt_SUB         8
1041 #define CXt_FORMAT      9
1042 #define CXt_EVAL       10
1043 #define CXt_SUBST      11
1044 /* SUBST doesn't feature in all switch statements.  */
1045
1046 /* private flags for CXt_SUB and CXt_NULL
1047    However, this is checked in many places which do not check the type, so
1048    this bit needs to be kept clear for most everything else. For reasons I
1049    haven't investigated, it can coexist with CXp_FOR_DEF */
1050 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
1051                                    tear down context on exit). */ 
1052
1053 /* private flags for CXt_SUB and CXt_FORMAT */
1054 #define CXp_HASARGS     0x20
1055 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1056 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1057
1058 /* private flags for CXt_EVAL */
1059 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1060 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1061
1062 /* private flags for CXt_LOOP */
1063 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1064 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1065 #define CXp_FOR_GV      0x40    /* foreach using package var */
1066 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1067 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1068
1069 /* private flags for CXt_SUBST */
1070 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1071
1072 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1073 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1074 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
1075                          == CXp_MULTICALL)
1076 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1077                          == (CXt_EVAL|CXp_REAL))
1078 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1079                          == (CXt_EVAL|CXp_TRYBLOCK))
1080 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1081 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1082                          && ((c)->cx_type & CXp_FOR_DEF))
1083
1084 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1085
1086 /* 
1087 =head1 "Gimme" Values
1088 */
1089
1090 /*
1091 =for apidoc AmU||G_SCALAR
1092 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1093 L<perlcall>.
1094
1095 =for apidoc AmU||G_ARRAY
1096 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1097 L<perlcall>.
1098
1099 =for apidoc AmU||G_VOID
1100 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1101
1102 =for apidoc AmU||G_DISCARD
1103 Indicates that arguments returned from a callback should be discarded.  See
1104 L<perlcall>.
1105
1106 =for apidoc AmU||G_EVAL
1107
1108 Used to force a Perl C<eval> wrapper around a callback.  See
1109 L<perlcall>.
1110
1111 =for apidoc AmU||G_NOARGS
1112
1113 Indicates that no arguments are being sent to a callback.  See
1114 L<perlcall>.
1115
1116 =cut
1117 */
1118
1119 #define G_SCALAR        2
1120 #define G_ARRAY         3
1121 #define G_VOID          1
1122 #define G_WANT          3
1123
1124 /* extra flags for Perl_call_* routines */
1125 #define G_DISCARD       4       /* Call FREETMPS.
1126                                    Don't change this without consulting the
1127                                    hash actions codes defined in hv.h */
1128 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1129 #define G_NOARGS       16       /* Don't construct a @_ array. */
1130 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1131 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1132 #define G_METHOD      128       /* Calling method. */
1133 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1134                                    fold_constants. */
1135 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1136                                    A special case for UNSHIFT in
1137                                    Perl_magic_methcall().  */
1138 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1139                                     Perl_magic_methcall().  */
1140 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1141 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1142
1143 /* flag bits for PL_in_eval */
1144 #define EVAL_NULL       0       /* not in an eval */
1145 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1146 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1147 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1148 #define EVAL_INREQUIRE  8       /* The code is being required. */
1149 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1150
1151 /* Support for switching (stack and block) contexts.
1152  * This ensures magic doesn't invalidate local stack and cx pointers.
1153  */
1154
1155 #define PERLSI_UNKNOWN          -1
1156 #define PERLSI_UNDEF            0
1157 #define PERLSI_MAIN             1
1158 #define PERLSI_MAGIC            2
1159 #define PERLSI_SORT             3
1160 #define PERLSI_SIGNAL           4
1161 #define PERLSI_OVERLOAD         5
1162 #define PERLSI_DESTROY          6
1163 #define PERLSI_WARNHOOK         7
1164 #define PERLSI_DIEHOOK          8
1165 #define PERLSI_REQUIRE          9
1166 #define PERLSI_MULTICALL       10
1167
1168 struct stackinfo {
1169     AV *                si_stack;       /* stack for current runlevel */
1170     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1171     struct stackinfo *  si_prev;
1172     struct stackinfo *  si_next;
1173     I32                 si_cxix;        /* current context index */
1174     I32                 si_cxmax;       /* maximum allocated index */
1175     I32                 si_type;        /* type of runlevel */
1176     I32                 si_markoff;     /* offset where markstack begins for us.
1177                                          * currently used only with DEBUGGING,
1178                                          * but not #ifdef-ed for bincompat */
1179 };
1180
1181 typedef struct stackinfo PERL_SI;
1182
1183 #define cxstack         (PL_curstackinfo->si_cxstack)
1184 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1185 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1186
1187 #ifdef DEBUGGING
1188 #  define       SET_MARK_OFFSET \
1189     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1190 #else
1191 #  define       SET_MARK_OFFSET NOOP
1192 #endif
1193
1194 #define PUSHSTACKi(type) \
1195     STMT_START {                                                        \
1196         PERL_SI *next = PL_curstackinfo->si_next;                       \
1197         DEBUG_l({                                                       \
1198             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1199             while (p) { i++; p = p->si_prev; }                          \
1200             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1201                          i, __FILE__, __LINE__);})                      \
1202         if (!next) {                                                    \
1203             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1204             next->si_prev = PL_curstackinfo;                            \
1205             PL_curstackinfo->si_next = next;                            \
1206         }                                                               \
1207         next->si_type = type;                                           \
1208         next->si_cxix = -1;                                             \
1209         AvFILLp(next->si_stack) = 0;                                    \
1210         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1211         PL_curstackinfo = next;                                         \
1212         SET_MARK_OFFSET;                                                \
1213     } STMT_END
1214
1215 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1216
1217 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1218  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1219 #define POPSTACK \
1220     STMT_START {                                                        \
1221         dSP;                                                            \
1222         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1223         DEBUG_l({                                                       \
1224             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1225             while (p) { i++; p = p->si_prev; }                          \
1226             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1227                          i, __FILE__, __LINE__);})                      \
1228         if (!prev) {                                                    \
1229             Perl_croak_popstack();                                      \
1230         }                                                               \
1231         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1232         /* don't free prev here, free them all at the END{} */          \
1233         PL_curstackinfo = prev;                                         \
1234     } STMT_END
1235
1236 #define POPSTACK_TO(s) \
1237     STMT_START {                                                        \
1238         while (PL_curstack != s) {                                      \
1239             dounwind(-1);                                               \
1240             POPSTACK;                                                   \
1241         }                                                               \
1242     } STMT_END
1243
1244 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1245 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1246
1247 /*
1248 =head1 Multicall Functions
1249
1250 =for apidoc Ams||dMULTICALL
1251 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1252
1253 =for apidoc Ams||PUSH_MULTICALL
1254 Opening bracket for a lightweight callback.
1255 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1256
1257 =for apidoc Ams||MULTICALL
1258 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1259
1260 =for apidoc Ams||POP_MULTICALL
1261 Closing bracket for a lightweight callback.
1262 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1263
1264 =cut
1265 */
1266
1267 #define dMULTICALL \
1268     SV **newsp;                 /* set by POPBLOCK */                   \
1269     PERL_CONTEXT *cx;                                                   \
1270     CV *multicall_cv;                                                   \
1271     OP *multicall_cop;                                                  \
1272     bool multicall_oldcatch;                                            \
1273     U8 hasargs = 0              /* used by PUSHSUB */
1274
1275 #define PUSH_MULTICALL(the_cv) \
1276     PUSH_MULTICALL_FLAGS(the_cv, 0)
1277
1278 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1279  * for the CX stack entry (this isn't part of the public API) */
1280
1281 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1282     STMT_START {                                                        \
1283         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1284         CV * const cv = _nOnclAshIngNamE_;                              \
1285         PADLIST * const padlist = CvPADLIST(cv);                        \
1286         multicall_oldcatch = CATCH_GET;                                 \
1287         CATCH_SET(TRUE);                                                \
1288         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1289         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1290         PUSHSUB(cx);                                                    \
1291         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
1292         SAVEVPTR(PL_op);                                                \
1293         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1294             CvDEPTH(cv)++;                                              \
1295         if (CvDEPTH(cv) >= 2) {                                         \
1296             PERL_STACK_OVERFLOW_CHECK();                                \
1297             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1298         }                                                               \
1299         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1300         multicall_cv = cv;                                              \
1301         multicall_cop = CvSTART(cv);                                    \
1302     } STMT_END
1303
1304 #define MULTICALL \
1305     STMT_START {                                                        \
1306         PL_op = multicall_cop;                                          \
1307         CALLRUNOPS(aTHX);                                               \
1308     } STMT_END
1309
1310 #define POP_MULTICALL \
1311     STMT_START {                                                        \
1312         cx = &cxstack[cxstack_ix];                                      \
1313         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1314         POPBLOCK(cx,PL_curpm);                                          \
1315         /* these two set for backcompat by callers */                   \
1316         newsp = PL_stack_base + cx->blk_oldsp;                          \
1317         gimme = cx->blk_gimme;                                          \
1318         /* includes partial unrolled POPSUB(): */                       \
1319         CX_LEAVE_SCOPE(cx);                                             \
1320         PL_comppad = cx->blk_sub.prevcomppad;                           \
1321         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
1322         SvREFCNT_dec_NN(multicall_cv);                                  \
1323         POPSTACK;                                                       \
1324         CATCH_SET(multicall_oldcatch);                                  \
1325         SPAGAIN;                                                        \
1326     } STMT_END
1327
1328 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1329  * (this isn't part of the public API) */
1330
1331 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1332     STMT_START {                                                        \
1333         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1334         CV * const cv = _nOnclAshIngNamE_;                              \
1335         PADLIST * const padlist = CvPADLIST(cv);                        \
1336         cx = &cxstack[cxstack_ix];                                      \
1337         assert(cx->cx_type & CXp_MULTICALL);                            \
1338         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1339         SvREFCNT_dec_NN(multicall_cv);                                  \
1340         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1341         {                                                               \
1342             /* save a few things that we don't want PUSHSUB to zap */   \
1343             PAD * const prevcomppad = cx->blk_sub.prevcomppad;          \
1344             SSize_t old_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;     \
1345             SSize_t floor = PL_tmps_floor;                              \
1346             PUSHSUB(cx);                                                \
1347             /* undo the stuff that PUSHSUB zapped */                    \
1348             cx->blk_sub.prevcomppad = prevcomppad ;                     \
1349             cx->cx_u.cx_blk.blku_old_tmpsfloor = old_floor;             \
1350             PL_tmps_floor = floor;                                      \
1351         }                                                               \
1352         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1353             CvDEPTH(cv)++;                                              \
1354         if (CvDEPTH(cv) >= 2) {                                         \
1355             PERL_STACK_OVERFLOW_CHECK();                                \
1356             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1357         }                                                               \
1358         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1359         multicall_cv = cv;                                              \
1360         multicall_cop = CvSTART(cv);                                    \
1361     } STMT_END
1362 /*
1363  * ex: set ts=8 sts=4 sw=4 et:
1364  */