This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
fbaa8a04e842077dd83a3fa7b1853d6b693e3350
[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,sv)                                                   \
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_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
682         PL_comppad = cx->blk_sub.prevcomppad;                           \
683         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
684         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
685         CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth;                  \
686     } STMT_END
687
688 #define LEAVESUB(sv)                                                    \
689     STMT_START {                                                        \
690         SvREFCNT_dec(sv);                                               \
691     } STMT_END
692
693 #define POPFORMAT(cx)                                                   \
694     STMT_START {                                                        \
695         CX_LEAVE_SCOPE(cx);                                             \
696         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
697         CV * const cv = cx->blk_format.cv;                              \
698         GV * const dfuot = cx->blk_format.dfoutgv;                      \
699         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
700         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
701         setdefout(dfuot);                                               \
702         PL_comppad = cx->blk_format.prevcomppad;                        \
703         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
704         --CvDEPTH(cv);                                                  \
705         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
706         SvREFCNT_dec_NN(dfuot);                                         \
707         }                                                               \
708     } STMT_END
709
710 /* eval context */
711 struct block_eval {
712     OP *        retop;  /* op to execute on exit from eval */
713     /* Above here is the same for sub, format and eval.  */
714     SV *        old_namesv;
715     OP *        old_eval_root;
716     SV *        cur_text;
717     CV *        cv;
718     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
719 };
720
721 /* If we ever need more than 512 op types, change the shift from 7.
722    blku_gimme is actually also only 2 bits, so could be merged with something.
723 */
724
725 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
726 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
727
728 #define PUSHEVAL(cx,n)                                                  \
729     STMT_START {                                                        \
730         assert(!(PL_in_eval & ~0x7F));                                  \
731         assert(!(PL_op->op_type & ~0x1FF));                             \
732         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
733         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
734         PL_tmps_floor = PL_tmps_ix;                                     \
735         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
736         cx->blk_eval.old_eval_root = PL_eval_root;                      \
737         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
738         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
739         cx->blk_eval.retop = NULL;                                      \
740         cx->blk_eval.cur_top_env = PL_top_env;                          \
741     } STMT_END
742
743 #define POPEVAL(cx)                                                     \
744     STMT_START {                                                        \
745         CX_LEAVE_SCOPE(cx);                                             \
746         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
747         optype = CxOLD_OP_TYPE(cx);                                     \
748         PL_eval_root = cx->blk_eval.old_eval_root;                      \
749         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
750             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
751         if (cx->blk_eval.old_namesv)                                    \
752             sv_2mortal(cx->blk_eval.old_namesv);                        \
753     } STMT_END
754
755 /* loop context */
756 struct block_loop {
757     I32         resetsp;
758     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
759     union {     /* different ways of locating the iteration variable */
760         SV      **svp; /* for lexicals: address of pad slot */
761         GV      *gv;   /* for package vars */
762     } itervar_u;
763     SV          *itersave; /* the original iteration var */
764     union {
765         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
766             AV * ary; /* use the stack if this is NULL */
767             IV ix;
768         } ary;
769         struct { /* valid if type is LOOP_LAZYIV */
770             IV cur;
771             IV end;
772         } lazyiv;
773         struct { /* valid if type if LOOP_LAZYSV */
774             SV * cur;
775             SV * end; /* maxiumum value (or minimum in reverse) */
776         } lazysv;
777     } state_u;
778 #ifdef USE_ITHREADS
779     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
780 #endif
781 };
782
783 #define CxITERVAR(c)                                    \
784         (CxPADLOOP(c)                                   \
785             ? (c)->blk_loop.itervar_u.svp               \
786             : ((c)->cx_type & CXp_FOR_GV)               \
787                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
788                 : (SV **)&(c)->blk_loop.itervar_u.gv)
789
790 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
791 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
792 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
793 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
794 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
795 /* POPSUB has already been performed on this context frame */
796 #define CxPOPSUB_DONE 0x100
797
798
799 #define PUSHLOOP_PLAIN(cx, s)                                           \
800         cx->blk_loop.resetsp = s - PL_stack_base;                       \
801         cx->blk_loop.my_op = cLOOP;                                     \
802         cx->blk_loop.state_u.ary.ary = NULL;                            \
803         cx->blk_loop.state_u.ary.ix = 0;                                \
804         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
805         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
806         PL_tmps_floor = PL_tmps_ix;                                     \
807         cx->blk_loop.itervar_u.svp = NULL;                              \
808         cx->blk_loop.itersave = NULL;
809
810 #ifdef USE_ITHREADS
811 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
812 #else
813 #  define PUSHLOOP_FOR_setpad(c) NOOP
814 #endif
815
816 #define PUSHLOOP_FOR(cx, ivar, isave, s)                                \
817         cx->blk_loop.resetsp = s - PL_stack_base;                       \
818         cx->blk_loop.my_op = cLOOP;                                     \
819         cx->blk_loop.state_u.ary.ary = NULL;                            \
820         cx->blk_loop.state_u.ary.ix = 0;                                \
821         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
822         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
823         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
824         PL_tmps_floor = PL_tmps_ix;                                     \
825         cx->blk_loop.itersave = isave;                                  \
826         PUSHLOOP_FOR_setpad(cx);
827
828 #define POPLOOP(cx)                                                     \
829         CX_LEAVE_SCOPE(cx);                                             \
830         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
831             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
832             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
833         }                                                               \
834         else if (CxTYPE(cx) == CXt_LOOP_FOR)                            \
835             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
836         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
837             SV *cursv;                                                  \
838             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
839             if ((cx->cx_type & CXp_FOR_GV))                             \
840                 svp = &GvSV((GV*)svp);                                  \
841             cursv = *svp;                                               \
842             *svp = cx->blk_loop.itersave;                               \
843             SvREFCNT_dec(cursv);                                        \
844         }                                                               \
845         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
846
847 /* given/when context */
848 struct block_givwhen {
849         OP *leave_op;
850         SV *defsv_save; /* the original $_ */
851 };
852
853 #define PUSHWHEN(cx)                                                    \
854         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
855         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
856         PL_tmps_floor = PL_tmps_ix;                                     \
857         cx->blk_givwhen.leave_op = cLOGOP->op_other;
858
859 #define PUSHGIVEN(cx, orig_var)                                         \
860         PUSHWHEN(cx);                                                   \
861         cx->blk_givwhen.defsv_save = orig_var;
862
863 #define POPWHEN(cx)                                                     \
864         CX_LEAVE_SCOPE(cx);                                             \
865         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
866
867 #define POPGIVEN(cx)                                                    \
868         CX_LEAVE_SCOPE(cx);                                             \
869         SvREFCNT_dec(GvSV(PL_defgv));                                   \
870         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;                    \
871         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
872
873
874 /* basic block, i.e. pp_enter/leave */
875
876 #define PUSHBASICBLK(cx)                                                \
877         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
878         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
879         PL_tmps_floor = PL_tmps_ix;
880
881 #define POPBASICBLK(cx)                                                 \
882         CX_LEAVE_SCOPE(cx);                                             \
883         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
884
885
886 /* context common to subroutines, evals and loops */
887 struct block {
888     U8          blku_type;      /* what kind of context this is */
889     U8          blku_gimme;     /* is this block running in list context? */
890     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
891     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
892     COP *       blku_oldcop;    /* old curcop pointer */
893     I32         blku_oldmarksp; /* mark stack index */
894     I32         blku_oldscopesp;        /* scope stack index */
895     PMOP *      blku_oldpm;     /* values of pattern match vars */
896     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
897     I32         blku_old_savestack_ix;  /* saved PL_savestack_ix */
898
899     union {
900         struct block_sub        blku_sub;
901         struct block_format     blku_format;
902         struct block_eval       blku_eval;
903         struct block_loop       blku_loop;
904         struct block_givwhen    blku_givwhen;
905     } blk_u;
906 };
907 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
908 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
909 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
910 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
911 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
912 #define blk_gimme       cx_u.cx_blk.blku_gimme
913 #define blk_u16         cx_u.cx_blk.blku_u16
914 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
915 #define blk_format      cx_u.cx_blk.blk_u.blku_format
916 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
917 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
918 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
919
920 #define DEBUG_CX(action)                                                \
921     DEBUG_l(                                                            \
922         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
923                     (long)cxstack_ix,                                   \
924                     action,                                             \
925                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
926                     (long)PL_scopestack_ix,                             \
927                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
928                     (long)PL_savestack_ix,                              \
929                     (long)(cxstack[cxstack_ix].cx_u.cx_blk.blku_old_savestack_ix),\
930                     __FILE__, __LINE__));
931
932 /* Enter a block. */
933 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
934         cx->cx_type             = t,                                    \
935         cx->blk_oldsp           = sp - PL_stack_base,                   \
936         cx->blk_oldcop          = PL_curcop,                            \
937         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
938         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
939         cx->blk_oldpm           = PL_curpm,                             \
940         cx->blk_gimme           = (U8)gimme;                            \
941         DEBUG_CX("PUSH");
942
943 /* Exit a block (RETURN and LAST). */
944 #define POPBLOCK(cx,pm)                                                 \
945         DEBUG_CX("POP");                                                \
946         cx = &cxstack[cxstack_ix--],                                    \
947         PL_curcop        = cx->blk_oldcop,                              \
948         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
949         PL_scopestack_ix = cx->blk_oldscopesp,                          \
950         pm               = cx->blk_oldpm;
951
952 /* Continue a block elsewhere (NEXT and REDO). */
953 #define TOPBLOCK(cx)                                                    \
954         DEBUG_CX("TOP");                                                \
955         cx  = &cxstack[cxstack_ix],                                     \
956         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
957         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
958         PL_scopestack_ix = cx->blk_oldscopesp,                          \
959         PL_curpm         = cx->blk_oldpm;
960
961 /* substitution context */
962 struct subst {
963     U8          sbu_type;       /* what kind of context this is */
964     U8          sbu_rflags;
965     U16         sbu_rxtainted;  /* matches struct block */
966     I32         sbu_oldsave;
967     SSize_t     sbu_iters;
968     SSize_t     sbu_maxiters;
969     char *      sbu_orig;
970     SV *        sbu_dstr;
971     SV *        sbu_targ;
972     char *      sbu_s;
973     char *      sbu_m;
974     char *      sbu_strend;
975     void *      sbu_rxres;
976     REGEXP *    sbu_rx;
977 };
978 #define sb_iters        cx_u.cx_subst.sbu_iters
979 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
980 #define sb_rflags       cx_u.cx_subst.sbu_rflags
981 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
982 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
983 #define sb_orig         cx_u.cx_subst.sbu_orig
984 #define sb_dstr         cx_u.cx_subst.sbu_dstr
985 #define sb_targ         cx_u.cx_subst.sbu_targ
986 #define sb_s            cx_u.cx_subst.sbu_s
987 #define sb_m            cx_u.cx_subst.sbu_m
988 #define sb_strend       cx_u.cx_subst.sbu_strend
989 #define sb_rxres        cx_u.cx_subst.sbu_rxres
990 #define sb_rx           cx_u.cx_subst.sbu_rx
991
992 #ifdef PERL_CORE
993 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
994         cx->sb_iters            = iters,                                \
995         cx->sb_maxiters         = maxiters,                             \
996         cx->sb_rflags           = r_flags,                              \
997         cx->sb_oldsave          = oldsave,                              \
998         cx->sb_rxtainted        = rxtainted,                            \
999         cx->sb_orig             = orig,                                 \
1000         cx->sb_dstr             = dstr,                                 \
1001         cx->sb_targ             = targ,                                 \
1002         cx->sb_s                = s,                                    \
1003         cx->sb_m                = m,                                    \
1004         cx->sb_strend           = strend,                               \
1005         cx->sb_rxres            = NULL,                                 \
1006         cx->sb_rx               = rx,                                   \
1007         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1008         rxres_save(&cx->sb_rxres, rx);                                  \
1009         (void)ReREFCNT_inc(rx);                                         \
1010         SvREFCNT_inc_void_NN(targ)
1011
1012 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
1013         rxres_free(&cx->sb_rxres);                                      \
1014         ReREFCNT_dec(cx->sb_rx);                                        \
1015         SvREFCNT_dec_NN(cx->sb_targ)
1016 #endif
1017
1018 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1019
1020 struct context {
1021     union {
1022         struct block    cx_blk;
1023         struct subst    cx_subst;
1024     } cx_u;
1025 };
1026 #define cx_type cx_u.cx_subst.sbu_type
1027
1028 /* If you re-order these, there is also an array of uppercase names in perl.h
1029    and a static array of context names in pp_ctl.c  */
1030 #define CXTYPEMASK      0xf
1031 #define CXt_NULL        0
1032 #define CXt_WHEN        1
1033 #define CXt_BLOCK       2
1034 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1035    jump table in pp_ctl.c
1036    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1037 */
1038 #define CXt_GIVEN       3
1039 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
1040 #define CXt_LOOP_FOR    4
1041 #define CXt_LOOP_PLAIN  5
1042 #define CXt_LOOP_LAZYSV 6
1043 #define CXt_LOOP_LAZYIV 7
1044 #define CXt_SUB         8
1045 #define CXt_FORMAT      9
1046 #define CXt_EVAL       10
1047 #define CXt_SUBST      11
1048 /* SUBST doesn't feature in all switch statements.  */
1049
1050 /* private flags for CXt_SUB and CXt_NULL
1051    However, this is checked in many places which do not check the type, so
1052    this bit needs to be kept clear for most everything else. For reasons I
1053    haven't investigated, it can coexist with CXp_FOR_DEF */
1054 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
1055                                    tear down context on exit). */ 
1056
1057 /* private flags for CXt_SUB and CXt_FORMAT */
1058 #define CXp_HASARGS     0x20
1059 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1060 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1061
1062 /* private flags for CXt_EVAL */
1063 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1064 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1065
1066 /* private flags for CXt_LOOP */
1067 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1068 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1069 #define CXp_FOR_GV      0x40    /* foreach using package var */
1070 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1071 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1072
1073 /* private flags for CXt_SUBST */
1074 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1075
1076 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1077 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1078 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
1079                          == CXp_MULTICALL)
1080 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1081                          == (CXt_EVAL|CXp_REAL))
1082 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1083                          == (CXt_EVAL|CXp_TRYBLOCK))
1084 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1085 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1086                          && ((c)->cx_type & CXp_FOR_DEF))
1087
1088 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1089
1090 /* 
1091 =head1 "Gimme" Values
1092 */
1093
1094 /*
1095 =for apidoc AmU||G_SCALAR
1096 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1097 L<perlcall>.
1098
1099 =for apidoc AmU||G_ARRAY
1100 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1101 L<perlcall>.
1102
1103 =for apidoc AmU||G_VOID
1104 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1105
1106 =for apidoc AmU||G_DISCARD
1107 Indicates that arguments returned from a callback should be discarded.  See
1108 L<perlcall>.
1109
1110 =for apidoc AmU||G_EVAL
1111
1112 Used to force a Perl C<eval> wrapper around a callback.  See
1113 L<perlcall>.
1114
1115 =for apidoc AmU||G_NOARGS
1116
1117 Indicates that no arguments are being sent to a callback.  See
1118 L<perlcall>.
1119
1120 =cut
1121 */
1122
1123 #define G_SCALAR        2
1124 #define G_ARRAY         3
1125 #define G_VOID          1
1126 #define G_WANT          3
1127
1128 /* extra flags for Perl_call_* routines */
1129 #define G_DISCARD       4       /* Call FREETMPS.
1130                                    Don't change this without consulting the
1131                                    hash actions codes defined in hv.h */
1132 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1133 #define G_NOARGS       16       /* Don't construct a @_ array. */
1134 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1135 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1136 #define G_METHOD      128       /* Calling method. */
1137 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1138                                    fold_constants. */
1139 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1140                                    A special case for UNSHIFT in
1141                                    Perl_magic_methcall().  */
1142 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1143                                     Perl_magic_methcall().  */
1144 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1145 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1146
1147 /* flag bits for PL_in_eval */
1148 #define EVAL_NULL       0       /* not in an eval */
1149 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1150 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1151 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1152 #define EVAL_INREQUIRE  8       /* The code is being required. */
1153 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1154
1155 /* Support for switching (stack and block) contexts.
1156  * This ensures magic doesn't invalidate local stack and cx pointers.
1157  */
1158
1159 #define PERLSI_UNKNOWN          -1
1160 #define PERLSI_UNDEF            0
1161 #define PERLSI_MAIN             1
1162 #define PERLSI_MAGIC            2
1163 #define PERLSI_SORT             3
1164 #define PERLSI_SIGNAL           4
1165 #define PERLSI_OVERLOAD         5
1166 #define PERLSI_DESTROY          6
1167 #define PERLSI_WARNHOOK         7
1168 #define PERLSI_DIEHOOK          8
1169 #define PERLSI_REQUIRE          9
1170 #define PERLSI_MULTICALL       10
1171
1172 struct stackinfo {
1173     AV *                si_stack;       /* stack for current runlevel */
1174     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1175     struct stackinfo *  si_prev;
1176     struct stackinfo *  si_next;
1177     I32                 si_cxix;        /* current context index */
1178     I32                 si_cxmax;       /* maximum allocated index */
1179     I32                 si_type;        /* type of runlevel */
1180     I32                 si_markoff;     /* offset where markstack begins for us.
1181                                          * currently used only with DEBUGGING,
1182                                          * but not #ifdef-ed for bincompat */
1183 };
1184
1185 typedef struct stackinfo PERL_SI;
1186
1187 #define cxstack         (PL_curstackinfo->si_cxstack)
1188 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1189 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1190
1191 #ifdef DEBUGGING
1192 #  define       SET_MARK_OFFSET \
1193     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1194 #else
1195 #  define       SET_MARK_OFFSET NOOP
1196 #endif
1197
1198 #define PUSHSTACKi(type) \
1199     STMT_START {                                                        \
1200         PERL_SI *next = PL_curstackinfo->si_next;                       \
1201         DEBUG_l({                                                       \
1202             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1203             while (p) { i++; p = p->si_prev; }                          \
1204             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1205                          i, __FILE__, __LINE__);})                      \
1206         if (!next) {                                                    \
1207             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1208             next->si_prev = PL_curstackinfo;                            \
1209             PL_curstackinfo->si_next = next;                            \
1210         }                                                               \
1211         next->si_type = type;                                           \
1212         next->si_cxix = -1;                                             \
1213         AvFILLp(next->si_stack) = 0;                                    \
1214         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1215         PL_curstackinfo = next;                                         \
1216         SET_MARK_OFFSET;                                                \
1217     } STMT_END
1218
1219 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1220
1221 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1222  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1223 #define POPSTACK \
1224     STMT_START {                                                        \
1225         dSP;                                                            \
1226         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1227         DEBUG_l({                                                       \
1228             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1229             while (p) { i++; p = p->si_prev; }                          \
1230             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1231                          i, __FILE__, __LINE__);})                      \
1232         if (!prev) {                                                    \
1233             Perl_croak_popstack();                                      \
1234         }                                                               \
1235         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1236         /* don't free prev here, free them all at the END{} */          \
1237         PL_curstackinfo = prev;                                         \
1238     } STMT_END
1239
1240 #define POPSTACK_TO(s) \
1241     STMT_START {                                                        \
1242         while (PL_curstack != s) {                                      \
1243             dounwind(-1);                                               \
1244             POPSTACK;                                                   \
1245         }                                                               \
1246     } STMT_END
1247
1248 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1249 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1250
1251 /*
1252 =head1 Multicall Functions
1253
1254 =for apidoc Ams||dMULTICALL
1255 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1256
1257 =for apidoc Ams||PUSH_MULTICALL
1258 Opening bracket for a lightweight callback.
1259 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1260
1261 =for apidoc Ams||MULTICALL
1262 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1263
1264 =for apidoc Ams||POP_MULTICALL
1265 Closing bracket for a lightweight callback.
1266 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1267
1268 =cut
1269 */
1270
1271 #define dMULTICALL \
1272     SV **newsp;                 /* set by POPBLOCK */                   \
1273     PERL_CONTEXT *cx;                                                   \
1274     CV *multicall_cv;                                                   \
1275     OP *multicall_cop;                                                  \
1276     bool multicall_oldcatch;                                            \
1277     U8 hasargs = 0              /* used by PUSHSUB */
1278
1279 #define PUSH_MULTICALL(the_cv) \
1280     PUSH_MULTICALL_FLAGS(the_cv, 0)
1281
1282 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1283  * for the CX stack entry (this isn't part of the public API) */
1284
1285 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1286     STMT_START {                                                        \
1287         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1288         CV * const cv = _nOnclAshIngNamE_;                              \
1289         PADLIST * const padlist = CvPADLIST(cv);                        \
1290         multicall_oldcatch = CATCH_GET;                                 \
1291         CATCH_SET(TRUE);                                                \
1292         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1293         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1294         PUSHSUB(cx);                                                    \
1295         cx->cx_u.cx_blk.blku_old_savestack_ix = PL_savestack_ix;        \
1296         SAVEVPTR(PL_op);                                                \
1297         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1298             CvDEPTH(cv)++;                                              \
1299         if (CvDEPTH(cv) >= 2) {                                         \
1300             PERL_STACK_OVERFLOW_CHECK();                                \
1301             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1302         }                                                               \
1303         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1304         multicall_cv = cv;                                              \
1305         multicall_cop = CvSTART(cv);                                    \
1306     } STMT_END
1307
1308 #define MULTICALL \
1309     STMT_START {                                                        \
1310         PL_op = multicall_cop;                                          \
1311         CALLRUNOPS(aTHX);                                               \
1312     } STMT_END
1313
1314 #define POP_MULTICALL \
1315     STMT_START {                                                        \
1316         cx = &cxstack[cxstack_ix];                                      \
1317         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1318         POPBLOCK(cx,PL_curpm);                                          \
1319         /* these two set for backcompat by callers */                   \
1320         newsp = PL_stack_base + cx->blk_oldsp;                          \
1321         gimme = cx->blk_gimme;                                          \
1322         /* includes partial unrolled POPSUB(): */                       \
1323         CX_LEAVE_SCOPE(cx);                                             \
1324         PL_comppad = cx->blk_sub.prevcomppad;                           \
1325         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
1326         LEAVESUB(multicall_cv);                                         \
1327         POPSTACK;                                                       \
1328         CATCH_SET(multicall_oldcatch);                                  \
1329         SPAGAIN;                                                        \
1330     } STMT_END
1331
1332 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1333  * (this isn't part of the public API) */
1334
1335 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1336     STMT_START {                                                        \
1337         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1338         CV * const cv = _nOnclAshIngNamE_;                              \
1339         PADLIST * const padlist = CvPADLIST(cv);                        \
1340         cx = &cxstack[cxstack_ix];                                      \
1341         assert(cx->cx_type & CXp_MULTICALL);                            \
1342         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1343         LEAVESUB(multicall_cv);                                         \
1344         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1345         {                                                               \
1346             /* save a few things that we don't want PUSHSUB to zap */   \
1347             PAD * const prevcomppad = cx->blk_sub.prevcomppad;          \
1348             SSize_t old_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;     \
1349             SSize_t floor = PL_tmps_floor;                              \
1350             PUSHSUB(cx);                                                \
1351             /* undo the stuff that PUSHSUB zapped */                    \
1352             cx->blk_sub.prevcomppad = prevcomppad ;                     \
1353             cx->cx_u.cx_blk.blku_old_tmpsfloor = old_floor;             \
1354             PL_tmps_floor = floor;                                      \
1355         }                                                               \
1356         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1357             CvDEPTH(cv)++;                                              \
1358         if (CvDEPTH(cv) >= 2) {                                         \
1359             PERL_STACK_OVERFLOW_CHECK();                                \
1360             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1361         }                                                               \
1362         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1363         multicall_cv = cv;                                              \
1364         multicall_cop = CvSTART(cv);                                    \
1365     } STMT_END
1366 /*
1367  * ex: set ts=8 sts=4 sw=4 et:
1368  */