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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         SvREFCNT_dec(av);                                               \
651     } STMT_END
652
653 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
654  * leave any (a fast av_clear(ary), basically) */
655 #define CLEAR_ARGARRAY(ary) \
656     STMT_START {                                                        \
657         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
658         AvARRAY(ary) = AvALLOC(ary);                                    \
659         AvFILLp(ary) = -1;                                              \
660     } STMT_END
661
662
663 /* subsets of POPSUB */
664
665 #define POPSUB_COMMON(cx) \
666     PL_comppad = cx->blk_sub.prevcomppad;                               \
667     PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;        \
668     CvDEPTH((const CV*)cx->blk_sub.cv) = cx->blk_sub.olddepth;          \
669     SvREFCNT_dec_NN(cx->blk_sub.cv);
670
671 /* handle the @_ part of leaving a sub */
672
673 #define POPSUB_ARGS(cx) \
674     STMT_START {                                                        \
675         AV *av;                                                         \
676         assert(AvARRAY(MUTABLE_AV(                                      \
677             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
678                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
679         POP_SAVEARRAY();                                                \
680         /* abandon @_ if it got reified */                              \
681         av = MUTABLE_AV(PAD_SVl(0));                                    \
682         if (UNLIKELY(AvREAL(av)))                                       \
683             clear_defarray(av, 0);                                      \
684         else {                                                          \
685             CLEAR_ARGARRAY(av);                                         \
686         }                                                               \
687     } STMT_END
688
689 #define POPSUB(cx)                                                      \
690     STMT_START {                                                        \
691         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
692         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
693         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
694                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
695                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
696                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
697                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
698                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
699                                                                         \
700         if (CxHASARGS(cx)) {                                            \
701             POPSUB_ARGS(cx);                                            \
702         }                                                               \
703         }                                                               \
704         POPSUB_COMMON(cx);                                              \
705     } STMT_END
706
707 #define POPFORMAT(cx)                                                   \
708     STMT_START {                                                        \
709         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
710         CV * const cv = cx->blk_format.cv;                              \
711         GV * const dfuot = cx->blk_format.dfoutgv;                      \
712         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
713         setdefout(dfuot);                                               \
714         PL_comppad = cx->blk_format.prevcomppad;                        \
715         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
716         --CvDEPTH(cv);                                                  \
717         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
718         SvREFCNT_dec_NN(dfuot);                                         \
719         }                                                               \
720     } STMT_END
721
722 /* eval context */
723 struct block_eval {
724     OP *        retop;  /* op to execute on exit from eval */
725     /* Above here is the same for sub, format and eval.  */
726     SV *        old_namesv;
727     OP *        old_eval_root;
728     SV *        cur_text;
729     CV *        cv;
730     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
731 };
732
733 /* If we ever need more than 512 op types, change the shift from 7.
734    blku_gimme is actually also only 2 bits, so could be merged with something.
735 */
736
737 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
738 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
739
740 #define PUSHEVAL(cx,n)                                                  \
741     STMT_START {                                                        \
742         assert(!(PL_in_eval & ~0x7F));                                  \
743         assert(!(PL_op->op_type & ~0x1FF));                             \
744         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
745         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
746         cx->blk_eval.old_eval_root = PL_eval_root;                      \
747         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
748         cx->blk_eval.cv = NULL; /* set by doeval_compile() as applicable */ \
749         cx->blk_eval.retop = NULL;                                      \
750         cx->blk_eval.cur_top_env = PL_top_env;                          \
751     } STMT_END
752
753 #define POPEVAL(cx)                                                     \
754     STMT_START {                                                        \
755         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
756         PL_eval_root = cx->blk_eval.old_eval_root;                      \
757         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
758             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
759         if (cx->blk_eval.old_namesv)                                    \
760             sv_2mortal(cx->blk_eval.old_namesv);                        \
761     } STMT_END
762
763 /* loop context */
764 struct block_loop {
765     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
766     union {     /* different ways of locating the iteration variable */
767         SV      **svp; /* for lexicals: address of pad slot */
768         GV      *gv;   /* for package vars */
769     } itervar_u;
770     SV          *itersave; /* the original iteration var */
771     union {
772         struct { /* CXt_LOOP_ARY, C<for (@ary)>  */
773             AV *ary; /* array being iterated over */
774             IV  ix;   /* index relative to base of array */
775         } ary;
776         struct { /* CXt_LOOP_LIST, C<for (list)> */
777             I32 basesp; /* first element of list on stack */
778             IV  ix;      /* index relative to basesp */
779         } stack;
780         struct { /* CXt_LOOP_LAZYIV, C<for (1..9)> */
781             IV cur;
782             IV end;
783         } lazyiv;
784         struct { /* CXt_LOOP_LAZYSV C<for ('a'..'z')> */
785             SV * cur;
786             SV * end; /* maxiumum value (or minimum in reverse) */
787         } lazysv;
788     } state_u;
789 #ifdef USE_ITHREADS
790     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
791 #endif
792 };
793
794 #define CxITERVAR(c)                                    \
795         (CxPADLOOP(c)                                   \
796             ? (c)->blk_loop.itervar_u.svp               \
797             : ((c)->cx_type & CXp_FOR_GV)               \
798                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
799                 : (SV **)&(c)->blk_loop.itervar_u.gv)
800
801 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
802 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
803 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
804 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
805 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
806 /* POPSUB has already been performed on this context frame */
807 #define CxPOPSUB_DONE 0x100
808
809
810 #define PUSHLOOP_PLAIN(cx)                                              \
811         cx->blk_loop.my_op = cLOOP;                                     \
812         cx->blk_oldsaveix = PL_savestack_ix;
813
814 #ifdef USE_ITHREADS
815 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
816 #else
817 #  define PUSHLOOP_FOR_setpad(c) NOOP
818 #endif
819
820 #define PUSHLOOP_FOR(cx, ivar, isave)                                   \
821         cx->blk_loop.my_op = cLOOP;                                     \
822         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
823         cx->blk_oldsaveix = PL_savestack_ix;                                \
824         cx->blk_loop.itersave = isave;                                  \
825         PUSHLOOP_FOR_setpad(cx);
826
827 #define POPLOOP(cx)                                                     \
828         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
829             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
830             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
831         }                                                               \
832         else if (CxTYPE(cx) == CXt_LOOP_ARY)                            \
833             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
834         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
835             SV *cursv;                                                  \
836             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
837             if ((cx->cx_type & CXp_FOR_GV))                             \
838                 svp = &GvSV((GV*)svp);                                  \
839             cursv = *svp;                                               \
840             *svp = cx->blk_loop.itersave;                               \
841             SvREFCNT_dec(cursv);                                        \
842         }
843
844 /* given/when context */
845 struct block_givwhen {
846         OP *leave_op;
847         SV *defsv_save; /* the original $_ */
848 };
849
850 #define PUSHWHEN(cx)                                                    \
851         cx->blk_oldsaveix = PL_savestack_ix;                            \
852         cx->blk_givwhen.leave_op = cLOGOP->op_other;
853
854 #define PUSHGIVEN(cx, orig_var)                                         \
855         PUSHWHEN(cx);                                                   \
856         cx->blk_givwhen.defsv_save = orig_var;
857
858 #define POPWHEN(cx)                                                     \
859         NOOP;
860
861 #define POPGIVEN(cx)                                                    \
862         SvREFCNT_dec(GvSV(PL_defgv));                                   \
863         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;
864
865
866 /* basic block, i.e. pp_enter/leave */
867
868 #define PUSHBASICBLK(cx)                                                \
869         cx->blk_oldsaveix = PL_savestack_ix;
870
871 #define POPBASICBLK(cx)                                                 \
872         NOOP;
873
874
875 /* context common to subroutines, evals and loops */
876 struct block {
877     U8          blku_type;      /* what kind of context this is */
878     U8          blku_gimme;     /* is this block running in list context? */
879     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
880     I32         blku_oldsaveix; /* saved PL_savestack_ix */
881     /* all the fields above must be aligned with same-sized fields as sbu */
882     I32         blku_oldsp;     /* current sp floor: where nextstate pops to */
883     COP *       blku_oldcop;    /* old curcop pointer */
884     I32         blku_oldmarksp; /* mark stack index */
885     I32         blku_oldscopesp;        /* scope stack index */
886     PMOP *      blku_oldpm;     /* values of pattern match vars */
887     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
888
889     union {
890         struct block_sub        blku_sub;
891         struct block_format     blku_format;
892         struct block_eval       blku_eval;
893         struct block_loop       blku_loop;
894         struct block_givwhen    blku_givwhen;
895     } blk_u;
896 };
897 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
898 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
899 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
900 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
901 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
902 #define blk_gimme       cx_u.cx_blk.blku_gimme
903 #define blk_u16         cx_u.cx_blk.blku_u16
904 #define blk_oldsaveix   cx_u.cx_blk.blku_oldsaveix
905 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
906 #define blk_format      cx_u.cx_blk.blk_u.blku_format
907 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
908 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
909 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
910
911 #define DEBUG_CX(action)                                                \
912     DEBUG_l(                                                            \
913         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
914                     (long)cxstack_ix,                                   \
915                     action,                                             \
916                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
917                     (long)PL_scopestack_ix,                             \
918                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
919                     (long)PL_savestack_ix,                              \
920                     (long)(cxstack[cxstack_ix].blk_oldsaveix),          \
921                     __FILE__, __LINE__));
922
923 /* Enter a block. */
924 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
925         cx->cx_type             = t,                                    \
926         cx->blk_oldsp           = sp - PL_stack_base,                   \
927         cx->blk_oldcop          = PL_curcop,                            \
928         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
929         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
930         cx->blk_oldpm           = PL_curpm,                             \
931         cx->blk_gimme           = (U8)gimme;                            \
932         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
933         PL_tmps_floor           = PL_tmps_ix;                           \
934         DEBUG_CX("PUSH");
935
936 /* Exit a block (RETURN and LAST). */
937 #define POPBLOCK(cx)                                                    \
938         DEBUG_CX("POP");                                                \
939         PL_curcop        = cx->blk_oldcop,                              \
940         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
941         PL_scopestack_ix = cx->blk_oldscopesp,                          \
942         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
943          * and leaves a CX entry lying around for repeated use, so
944          * skip for multicall */                  \
945         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
946                 || PL_savestack_ix == cx->blk_oldsaveix);               \
947         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
948         PL_curpm         = cx->blk_oldpm;
949
950 /* Continue a block elsewhere (NEXT and REDO). */
951 #define TOPBLOCK(cx)                                                    \
952         DEBUG_CX("TOP");                                                \
953         cx  = &cxstack[cxstack_ix],                                     \
954         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
955         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
956         PL_scopestack_ix = cx->blk_oldscopesp,                          \
957         PL_curpm         = cx->blk_oldpm;
958
959 /* substitution context */
960 struct subst {
961     U8          sbu_type;       /* same as blku_type */
962     U8          sbu_rflags;
963     U16         sbu_rxtainted;
964     I32         sbu_oldsaveix; /* same as blku_oldsaveix */
965     /* all the fields above must be aligned with same-sized fields as blku * */
966     SSize_t     sbu_iters;
967     SSize_t     sbu_maxiters;
968     char *      sbu_orig;
969     SV *        sbu_dstr;
970     SV *        sbu_targ;
971     char *      sbu_s;
972     char *      sbu_m;
973     char *      sbu_strend;
974     void *      sbu_rxres;
975     REGEXP *    sbu_rx;
976 };
977 #define sb_iters        cx_u.cx_subst.sbu_iters
978 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
979 #define sb_rflags       cx_u.cx_subst.sbu_rflags
980 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
981 #define sb_orig         cx_u.cx_subst.sbu_orig
982 #define sb_dstr         cx_u.cx_subst.sbu_dstr
983 #define sb_targ         cx_u.cx_subst.sbu_targ
984 #define sb_s            cx_u.cx_subst.sbu_s
985 #define sb_m            cx_u.cx_subst.sbu_m
986 #define sb_strend       cx_u.cx_subst.sbu_strend
987 #define sb_rxres        cx_u.cx_subst.sbu_rxres
988 #define sb_rx           cx_u.cx_subst.sbu_rx
989
990 #ifdef PERL_CORE
991 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
992         cx->blk_oldsaveix = oldsave,                                    \
993         cx->sb_iters            = iters,                                \
994         cx->sb_maxiters         = maxiters,                             \
995         cx->sb_rflags           = r_flags,                              \
996         cx->sb_rxtainted        = rxtainted,                            \
997         cx->sb_orig             = orig,                                 \
998         cx->sb_dstr             = dstr,                                 \
999         cx->sb_targ             = targ,                                 \
1000         cx->sb_s                = s,                                    \
1001         cx->sb_m                = m,                                    \
1002         cx->sb_strend           = strend,                               \
1003         cx->sb_rxres            = NULL,                                 \
1004         cx->sb_rx               = rx,                                   \
1005         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1006         rxres_save(&cx->sb_rxres, rx);                                  \
1007         (void)ReREFCNT_inc(rx);                                         \
1008         SvREFCNT_inc_void_NN(targ)
1009
1010 #  define POPSUBST(cx) \
1011         rxres_free(&cx->sb_rxres);                                      \
1012         ReREFCNT_dec(cx->sb_rx);                                        \
1013         SvREFCNT_dec_NN(cx->sb_targ)
1014 #endif
1015
1016 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1017
1018 struct context {
1019     union {
1020         struct block    cx_blk;
1021         struct subst    cx_subst;
1022     } cx_u;
1023 };
1024 #define cx_type cx_u.cx_subst.sbu_type
1025
1026 /* If you re-order these, there is also an array of uppercase names in perl.h
1027    and a static array of context names in pp_ctl.c  */
1028 #define CXTYPEMASK      0xf
1029 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1030 #define CXt_WHEN        1
1031 #define CXt_BLOCK       2
1032 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1033    jump table in pp_ctl.c
1034    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1035 */
1036 #define CXt_GIVEN       3
1037
1038 /* be careful of the ordering of these five. Macros like CxTYPE_is_LOOP,
1039  * CxFOREACH compare ranges */
1040 #define CXt_LOOP_PLAIN  4 /*                {} */
1041 #define CXt_LOOP_LAZYIV 5 /* for (1..9)     {} */
1042 #define CXt_LOOP_LAZYSV 6 /* for ('a'..'z') {} */
1043 #define CXt_LOOP_LIST   7 /* for (1,2,3)    {} */
1044 #define CXt_LOOP_ARY    8 /* for (@ary)     {} */
1045
1046 #define CXt_SUB         9
1047 #define CXt_FORMAT     10
1048 #define CXt_EVAL       11
1049 #define CXt_SUBST      12
1050 /* SUBST doesn't feature in all switch statements.  */
1051
1052 /* private flags for CXt_SUB and CXt_FORMAT */
1053 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1054                                    context on exit). (not CXt_FORMAT) */
1055 #define CXp_HASARGS     0x20
1056 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1057 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1058
1059 /* private flags for CXt_EVAL */
1060 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1061 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1062
1063 /* private flags for CXt_LOOP */
1064 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1065 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1066 #define CXp_FOR_GV      0x40    /* foreach using package var */
1067 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1068 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1069
1070 /* private flags for CXt_SUBST */
1071 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1072
1073 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1074 #define CxTYPE_is_LOOP(c) (   CxTYPE(cx) >= CXt_LOOP_PLAIN              \
1075                            && CxTYPE(cx) <= CXt_LOOP_ARY)
1076 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1077 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1078                          == (CXt_EVAL|CXp_REAL))
1079 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1080                          == (CXt_EVAL|CXp_TRYBLOCK))
1081 #define CxFOREACH(c)    (   CxTYPE(cx) >= CXt_LOOP_LAZYSV               \
1082                          && CxTYPE(cx) <= CXt_LOOP_ARY)
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->blk_oldsaveix = 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         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1302         multicall_cop = CvSTART(cv);                                    \
1303     } STMT_END
1304
1305 #define MULTICALL \
1306     STMT_START {                                                        \
1307         PL_op = multicall_cop;                                          \
1308         CALLRUNOPS(aTHX);                                               \
1309     } STMT_END
1310
1311 #define POP_MULTICALL \
1312     STMT_START {                                                        \
1313         cx = &cxstack[cxstack_ix];                                      \
1314         CX_LEAVE_SCOPE(cx);                                             \
1315         POPSUB_COMMON(cx);                                              \
1316         newsp = PL_stack_base + cx->blk_oldsp;                          \
1317         gimme = cx->blk_gimme;                                          \
1318         PERL_UNUSED_VAR(newsp); /* for API */                           \
1319         PERL_UNUSED_VAR(gimme); /* for API */                           \
1320         POPBLOCK(cx);                                                   \
1321         CX_POP(cx);                                                     \
1322         POPSTACK;                                                       \
1323         CATCH_SET(multicall_oldcatch);                                  \
1324         SPAGAIN;                                                        \
1325     } STMT_END
1326
1327 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1328  * (this isn't part of the public API) */
1329
1330 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1331     STMT_START {                                                        \
1332         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1333         CV * const cv = _nOnclAshIngNamE_;                              \
1334         PADLIST * const padlist = CvPADLIST(cv);                        \
1335         cx = &cxstack[cxstack_ix];                                      \
1336         assert(CxMULTICALL(cx));                                        \
1337         POPSUB_COMMON(cx);                                              \
1338         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1339         PUSHSUB(cx);                                                    \
1340         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1341             CvDEPTH(cv)++;                                              \
1342         if (CvDEPTH(cv) >= 2) {                                         \
1343             PERL_STACK_OVERFLOW_CHECK();                                \
1344             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1345         }                                                               \
1346         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1347         multicall_cv = cv;                                              \
1348         multicall_cop = CvSTART(cv);                                    \
1349     } STMT_END
1350 /*
1351  * ex: set ts=8 sts=4 sw=4 et:
1352  */