9c25555d95d26d187baf7cf90287550c7aba1f9b
[perl.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 separate statements.
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 };
38
39 typedef struct jmpenv JMPENV;
40
41 /*
42  * How to build the first jmpenv.
43  *
44  * top_env needs to be non-zero. It points to an area
45  * in which longjmp() stuff is stored, as C callstack
46  * info there at least is thread specific this has to
47  * be per-thread. Otherwise a 'die' in a thread gives
48  * that thread the C stack of last thread to do an eval {}!
49  */
50
51 #define JMPENV_BOOTSTRAP \
52     STMT_START {                                \
53         PERL_POISON_EXPR(PoisonNew(&PL_start_env, 1, JMPENV));\
54         PL_top_env = &PL_start_env;             \
55         PL_start_env.je_prev = NULL;            \
56         PL_start_env.je_ret = -1;               \
57         PL_start_env.je_mustcatch = TRUE;       \
58     } STMT_END
59
60 /*
61  *   PERL_FLEXIBLE_EXCEPTIONS
62  * 
63  * All the flexible exceptions code has been removed.
64  * See the following threads for details:
65  *
66  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
67  * 
68  * Joshua's original patches (which weren't applied) and discussion:
69  * 
70  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
71  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
74  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
75  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
76  * 
77  * Chip's reworked patch and discussion:
78  * 
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
80  * 
81  * The flaw in these patches (which went unnoticed at the time) was
82  * that they moved some code that could potentially die() out of the
83  * region protected by the setjmp()s.  This caused exceptions within
84  * END blocks and such to not be handled by the correct setjmp().
85  * 
86  * The original patches that introduces flexible exceptions were:
87  *
88  * http://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
89  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a                                        
90  *  
91  */
92
93 #define dJMPENV         JMPENV cur_env
94
95 #define JMPENV_PUSH(v) \
96     STMT_START {                                                        \
97         DEBUG_l({                                                       \
98             int i = 0; JMPENV *p = PL_top_env;                          \
99             while (p) { i++; p = p->je_prev; }                          \
100             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
101                          i,  __FILE__, __LINE__);})                     \
102         cur_env.je_prev = PL_top_env;                                   \
103         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
104         PL_top_env = &cur_env;                                          \
105         cur_env.je_mustcatch = FALSE;                                   \
106         (v) = cur_env.je_ret;                                           \
107     } STMT_END
108
109 #define JMPENV_POP \
110     STMT_START {                                                        \
111         DEBUG_l({                                                       \
112             int i = -1; JMPENV *p = PL_top_env;                         \
113             while (p) { i++; p = p->je_prev; }                          \
114             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
115                          i, __FILE__, __LINE__);})                      \
116         assert(PL_top_env == &cur_env);                                 \
117         PL_top_env = cur_env.je_prev;                                   \
118     } STMT_END
119
120 #define JMPENV_JUMP(v) \
121     STMT_START {                                                \
122         DEBUG_l({                                               \
123             int i = -1; JMPENV *p = PL_top_env;                 \
124             while (p) { i++; p = p->je_prev; }                  \
125             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
126                          (int)v, i, __FILE__, __LINE__);})      \
127         if (PL_top_env->je_prev)                                \
128             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
129         if ((v) == 2)                                           \
130             PerlProc_exit(STATUS_EXIT);                         \
131         PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
132         PerlProc_exit(1);                                       \
133     } STMT_END
134
135 #define CATCH_GET               (PL_top_env->je_mustcatch)
136 #define CATCH_SET(v) \
137     STMT_START {                                                        \
138         DEBUG_l(                                                        \
139             Perl_deb(aTHX_                                              \
140                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
141                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
142                  __FILE__, __LINE__);)                                  \
143         PL_top_env->je_mustcatch = (v);                                 \
144     } STMT_END
145
146 /*
147 =head1 COP Hint Hashes
148 */
149
150 typedef struct refcounted_he COPHH;
151
152 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
153
154 /*
155 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
156
157 Look up the entry in the cop hints hash I<cophh> with the key specified by
158 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
159 the key octets are interpreted as UTF-8, otherwise they are interpreted
160 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
161 it has not been precomputed.  Returns a mortal scalar copy of the value
162 associated with the key, or C<&PL_sv_placeholder> if there is no value
163 associated with the key.
164
165 =cut
166 */
167
168 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
169     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
170
171 /*
172 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
173
174 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
175 string/length pair, and no precomputed hash.
176
177 =cut
178 */
179
180 #define cophh_fetch_pvs(cophh, key, flags) \
181     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
182
183 /*
184 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
185
186 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
187 a string/length pair.
188
189 =cut
190 */
191
192 #define cophh_fetch_pv(cophh, key, hash, flags) \
193     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
194
195 /*
196 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
197
198 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
199 string/length pair.
200
201 =cut
202 */
203
204 #define cophh_fetch_sv(cophh, key, hash, flags) \
205     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
206
207 /*
208 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
209
210 Generates and returns a standard Perl hash representing the full set of
211 key/value pairs in the cop hints hash I<cophh>.  I<flags> is currently
212 unused and must be zero.
213
214 =cut
215 */
216
217 #define cophh_2hv(cophh, flags) \
218     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
219
220 /*
221 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
222
223 Make and return a complete copy of the cop hints hash I<cophh>.
224
225 =cut
226 */
227
228 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
229
230 /*
231 =for apidoc Amx|void|cophh_free|COPHH *cophh
232
233 Discard the cop hints hash I<cophh>, freeing all resources associated
234 with it.
235
236 =cut
237 */
238
239 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
240
241 /*
242 =for apidoc Amx|COPHH *|cophh_new_empty
243
244 Generate and return a fresh cop hints hash containing no entries.
245
246 =cut
247 */
248
249 #define cophh_new_empty() ((COPHH *)NULL)
250
251 /*
252 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
253
254 Stores a value, associated with a key, in the cop hints hash I<cophh>,
255 and returns the modified hash.  The returned hash pointer is in general
256 not the same as the hash pointer that was passed in.  The input hash is
257 consumed by the function, and the pointer to it must not be subsequently
258 used.  Use L</cophh_copy> if you need both hashes.
259
260 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
261 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
262 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
263 hash of the key string, or zero if it has not been precomputed.
264
265 I<value> is the scalar value to store for this key.  I<value> is copied
266 by this function, which thus does not take ownership of any reference
267 to it, and later changes to the scalar will not be reflected in the
268 value visible in the cop hints hash.  Complex types of scalar will not
269 be stored with referential integrity, but will be coerced to strings.
270
271 =cut
272 */
273
274 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
275     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
276
277 /*
278 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
279
280 Like L</cophh_store_pvn>, but takes a literal string instead of a
281 string/length pair, and no precomputed hash.
282
283 =cut
284 */
285
286 #define cophh_store_pvs(cophh, key, value, flags) \
287     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
288
289 /*
290 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
291
292 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
293 a string/length pair.
294
295 =cut
296 */
297
298 #define cophh_store_pv(cophh, key, hash, value, flags) \
299     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
300
301 /*
302 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
303
304 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
305 string/length pair.
306
307 =cut
308 */
309
310 #define cophh_store_sv(cophh, key, hash, value, flags) \
311     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
312
313 /*
314 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
315
316 Delete a key and its associated value from the cop hints hash I<cophh>,
317 and returns the modified hash.  The returned hash pointer is in general
318 not the same as the hash pointer that was passed in.  The input hash is
319 consumed by the function, and the pointer to it must not be subsequently
320 used.  Use L</cophh_copy> if you need both hashes.
321
322 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
323 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
324 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
325 hash of the key string, or zero if it has not been precomputed.
326
327 =cut
328 */
329
330 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
331     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
332         (SV *)NULL, flags)
333
334 /*
335 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
336
337 Like L</cophh_delete_pvn>, but takes a literal string instead of a
338 string/length pair, and no precomputed hash.
339
340 =cut
341 */
342
343 #define cophh_delete_pvs(cophh, key, flags) \
344     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
345         (SV *)NULL, flags)
346
347 /*
348 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
349
350 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
351 a string/length pair.
352
353 =cut
354 */
355
356 #define cophh_delete_pv(cophh, key, hash, flags) \
357     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
358
359 /*
360 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
361
362 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
363 string/length pair.
364
365 =cut
366 */
367
368 #define cophh_delete_sv(cophh, key, hash, flags) \
369     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
370
371 #include "mydtrace.h"
372
373 struct cop {
374     BASEOP
375     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
376        an exact multiple of 8 bytes to save structure padding.  */
377     line_t      cop_line;       /* line # of this command */
378     /* label for this construct is now stored in cop_hints_hash */
379 #ifdef USE_ITHREADS
380     PADOFFSET   cop_stashoff;   /* offset into PL_stashpad, for the
381                                    package the line was compiled in */
382     char *      cop_file;       /* file name the following line # is from */
383 #else
384     HV *        cop_stash;      /* package line was compiled in */
385     GV *        cop_filegv;     /* file the following line # is from */
386 #endif
387     U32         cop_hints;      /* hints bits from pragmata */
388     U32         cop_seq;        /* parse sequence number */
389     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
390     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
391     /* compile time state of %^H.  See the comment in op.c for how this is
392        used to recreate a hash to return from caller.  */
393     COPHH *     cop_hints_hash;
394 };
395
396 #ifdef USE_ITHREADS
397 #  define CopFILE(c)            ((c)->cop_file)
398 #  define CopFILEGV(c)          (CopFILE(c) \
399                                  ? gv_fetchfile(CopFILE(c)) : NULL)
400                                  
401 #  ifdef NETWARE
402 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
403 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepvn((pv),(l)))
404 #  else
405 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
406 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
407 #  endif
408
409 #  define CopFILESV(c)          (CopFILE(c) \
410                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
411 #  define CopFILEAV(c)          (CopFILE(c) \
412                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
413 #  define CopFILEAVx(c)         (assert_(CopFILE(c)) \
414                                    GvAV(gv_fetchfile(CopFILE(c))))
415
416 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
417 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
418                                     ? alloccopstash(hv)                 \
419                                     : 0)
420 #  ifdef NETWARE
421 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
422 #  else
423 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
424 #  endif
425 #else
426 #  define CopFILEGV(c)          ((c)->cop_filegv)
427 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
428 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
429 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
430 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
431 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
432 #  ifdef DEBUGGING
433 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
434 #  else
435 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
436 # endif
437 #  define CopFILE(c)            (CopFILEGV(c) \
438                                     ? GvNAME(CopFILEGV(c))+2 : NULL)
439 #  define CopSTASH(c)           ((c)->cop_stash)
440 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
441 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
442
443 #endif /* USE_ITHREADS */
444
445 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
446    /* cop_stash is not refcounted */
447 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
448 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
449
450 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
451 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
452
453 /*
454 =head1 COP Hint Reading
455 */
456
457 /*
458 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
459
460 Look up the hint entry in the cop I<cop> with the key specified by
461 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
462 the key octets are interpreted as UTF-8, otherwise they are interpreted
463 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
464 it has not been precomputed.  Returns a mortal scalar copy of the value
465 associated with the key, or C<&PL_sv_placeholder> if there is no value
466 associated with the key.
467
468 =cut
469 */
470
471 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
472     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
473
474 /*
475 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
476
477 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
478 string/length pair, and no precomputed hash.
479
480 =cut
481 */
482
483 #define cop_hints_fetch_pvs(cop, key, flags) \
484     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
485
486 /*
487 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
488
489 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
490 of a string/length pair.
491
492 =cut
493 */
494
495 #define cop_hints_fetch_pv(cop, key, hash, flags) \
496     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
497
498 /*
499 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
500
501 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
502 string/length pair.
503
504 =cut
505 */
506
507 #define cop_hints_fetch_sv(cop, key, hash, flags) \
508     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
509
510 /*
511 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
512
513 Generates and returns a standard Perl hash representing the full set of
514 hint entries in the cop I<cop>.  I<flags> is currently unused and must
515 be zero.
516
517 =cut
518 */
519
520 #define cop_hints_2hv(cop, flags) \
521     cophh_2hv(CopHINTHASH_get(cop), flags)
522
523 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
524 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
525 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
526 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
527
528 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
529 #define CopLINE(c)              ((c)->cop_line)
530 #define CopLINE_inc(c)          (++CopLINE(c))
531 #define CopLINE_dec(c)          (--CopLINE(c))
532 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
533
534 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
535 #define OutCopFILE(c) CopFILE(c)
536
537 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
538 #define CopHINTS_set(c, h)      STMT_START {                            \
539                                     (c)->cop_hints = (h);               \
540                                 } STMT_END
541
542 /*
543  * Here we have some enormously heavy (or at least ponderous) wizardry.
544  */
545
546 /* subroutine context */
547 struct block_sub {
548     OP *        retop;  /* op to execute on exit from sub */
549     /* Above here is the same for sub, format and eval.  */
550     CV *        cv;
551     /* Above here is the same for sub and format.  */
552     AV *        savearray;
553     AV *        argarray;
554     I32         olddepth;
555     PAD         *oldcomppad;
556 };
557
558
559 /* format context */
560 struct block_format {
561     OP *        retop;  /* op to execute on exit from sub */
562     /* Above here is the same for sub, format and eval.  */
563     CV *        cv;
564     /* Above here is the same for sub and format.  */
565     GV *        gv;
566     GV *        dfoutgv;
567 };
568
569 /* base for the next two macros. Don't use directly.
570  * Note that the refcnt of the cv is incremented twice;  The CX one is
571  * decremented by LEAVESUB, the other by LEAVE. */
572
573 #define PUSHSUB_BASE(cx)                                                \
574         ENTRY_PROBE(CvNAMED(cv)                                         \
575                         ? HEK_KEY(CvNAME_HEK(cv))                       \
576                         : GvENAME(CvGV(cv)),                            \
577                 CopFILE((const COP *)CvSTART(cv)),                      \
578                 CopLINE((const COP *)CvSTART(cv)),                      \
579                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
580                                                                         \
581         cx->blk_sub.cv = cv;                                            \
582         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
583         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
584         cx->blk_sub.retop = NULL;                                       \
585         if (!CvDEPTH(cv)) {                                             \
586             SvREFCNT_inc_simple_void_NN(cv);                            \
587             SvREFCNT_inc_simple_void_NN(cv);                            \
588             SAVEFREESV(cv);                                             \
589         }
590
591 #define PUSHSUB_GET_LVALUE_MASK(func) \
592         /* If the context is indeterminate, then only the lvalue */     \
593         /* flags that the caller also has are applicable.        */     \
594         (                                                               \
595            (PL_op->op_flags & OPf_WANT)                                 \
596                ? OPpENTERSUB_LVAL_MASK                                  \
597                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
598                    ? 0 : (U8)func(aTHX)                                 \
599         )
600
601 #define PUSHSUB(cx)                                                     \
602     {                                                                   \
603         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
604         PUSHSUB_BASE(cx)                                                \
605         cx->blk_u16 = PL_op->op_private &                               \
606                           (phlags|OPpDEREF);                            \
607     }
608
609 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
610 #define PUSHSUB_DB(cx)                                                  \
611         PUSHSUB_BASE(cx)                                                \
612         cx->blk_u16 = 0;
613
614
615 #define PUSHFORMAT(cx, retop)                                           \
616         cx->blk_format.cv = cv;                                         \
617         cx->blk_format.gv = gv;                                         \
618         cx->blk_format.retop = (retop);                                 \
619         cx->blk_format.dfoutgv = PL_defoutgv;                           \
620         if (!CvDEPTH(cv)) SvREFCNT_inc_simple_void_NN(cv);              \
621         CvDEPTH(cv)++;                                                  \
622         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
623
624 #define POP_SAVEARRAY()                                         \
625     STMT_START {                                                        \
626         SvREFCNT_dec(GvAV(PL_defgv));                                   \
627         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
628     } STMT_END
629
630 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
631  * leave any (a fast av_clear(ary), basically) */
632 #define CLEAR_ARGARRAY(ary) \
633     STMT_START {                                                        \
634         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
635         AvARRAY(ary) = AvALLOC(ary);                                    \
636         AvFILLp(ary) = -1;                                              \
637     } STMT_END
638
639 #define POPSUB(cx,sv)                                                   \
640     STMT_START {                                                        \
641         const I32 olddepth = cx->blk_sub.olddepth;                      \
642         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
643                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
644                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
645                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
646                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
647                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
648                                                                         \
649         if (CxHASARGS(cx)) {                                            \
650             POP_SAVEARRAY();                                            \
651             /* abandon @_ if it got reified */                          \
652             if (AvREAL(cx->blk_sub.argarray)) {                         \
653                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
654                 SvREFCNT_dec_NN(cx->blk_sub.argarray);                  \
655                 cx->blk_sub.argarray = newAV();                         \
656                 av_extend(cx->blk_sub.argarray, fill);                  \
657                 AvREIFY_only(cx->blk_sub.argarray);                     \
658                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
659             }                                                           \
660             else {                                                      \
661                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
662             }                                                           \
663         }                                                               \
664         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
665         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
666         if (sv && (CvDEPTH((const CV*)sv) = olddepth))                  \
667             sv = NULL;                                          \
668     } STMT_END
669
670 #define LEAVESUB(sv)                                                    \
671     STMT_START {                                                        \
672         SvREFCNT_dec(sv);                                               \
673     } STMT_END
674
675 #define POPFORMAT(cx)                                                   \
676     STMT_START {                                                        \
677         CV * const cv = cx->blk_format.cv;                              \
678         GV * const dfuot = cx->blk_format.dfoutgv;                      \
679         setdefout(dfuot);                                               \
680         LEAVE_SCOPE(PL_scopestack[cx->blk_oldscopesp-1]);               \
681         if (!--CvDEPTH(cv))                                             \
682             SvREFCNT_dec_NN(cx->blk_format.cv);                         \
683         SvREFCNT_dec_NN(dfuot);                                         \
684     } STMT_END
685
686 /* eval context */
687 struct block_eval {
688     OP *        retop;  /* op to execute on exit from eval */
689     /* Above here is the same for sub, format and eval.  */
690     SV *        old_namesv;
691     OP *        old_eval_root;
692     SV *        cur_text;
693     CV *        cv;
694     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
695 };
696
697 /* If we ever need more than 512 op types, change the shift from 7.
698    blku_gimme is actually also only 2 bits, so could be merged with something.
699 */
700
701 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
702 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
703
704 #define PUSHEVAL(cx,n)                                                  \
705     STMT_START {                                                        \
706         assert(!(PL_in_eval & ~0x7F));                                  \
707         assert(!(PL_op->op_type & ~0x1FF));                             \
708         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
709         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
710         cx->blk_eval.old_eval_root = PL_eval_root;                      \
711         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
712         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
713         cx->blk_eval.retop = NULL;                                      \
714         cx->blk_eval.cur_top_env = PL_top_env;                          \
715     } STMT_END
716
717 #define POPEVAL(cx)                                                     \
718     STMT_START {                                                        \
719         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
720         optype = CxOLD_OP_TYPE(cx);                                     \
721         PL_eval_root = cx->blk_eval.old_eval_root;                      \
722         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
723             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
724         if (cx->blk_eval.old_namesv)                                    \
725             sv_2mortal(cx->blk_eval.old_namesv);                        \
726     } STMT_END
727
728 /* loop context */
729 struct block_loop {
730     I32         resetsp;
731     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
732     union {     /* different ways of locating the iteration variable */
733         SV      **svp;
734         GV      *gv;
735         PAD     *oldcomppad; /* only used in ITHREADS */
736     } itervar_u;
737     union {
738         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
739             AV * ary; /* use the stack if this is NULL */
740             IV ix;
741         } ary;
742         struct { /* valid if type is LOOP_LAZYIV */
743             IV cur;
744             IV end;
745         } lazyiv;
746         struct { /* valid if type if LOOP_LAZYSV */
747             SV * cur;
748             SV * end; /* maxiumum value (or minimum in reverse) */
749         } lazysv;
750     } state_u;
751 };
752
753 #ifdef USE_ITHREADS
754 #  define CxITERVAR_PADSV(c) \
755         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
756 #else
757 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
758 #endif
759
760 #define CxITERVAR(c)                                                    \
761         ((c)->blk_loop.itervar_u.oldcomppad                             \
762          ? (CxPADLOOP(c)                                                \
763             ? CxITERVAR_PADSV(c)                                        \
764             : isGV((c)->blk_loop.itervar_u.gv)                          \
765                 ? &GvSV((c)->blk_loop.itervar_u.gv)                     \
766                 : (SV **)&(c)->blk_loop.itervar_u.gv)                   \
767          : (SV**)NULL)
768
769 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
770 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
771 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
772 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
773 #define CxLVAL(c)       (0 + (c)->blk_u16)
774
775 #define PUSHLOOP_PLAIN(cx, s)                                           \
776         cx->blk_loop.resetsp = s - PL_stack_base;                       \
777         cx->blk_loop.my_op = cLOOP;                                     \
778         cx->blk_loop.state_u.ary.ary = NULL;                            \
779         cx->blk_loop.state_u.ary.ix = 0;                                \
780         cx->blk_loop.itervar_u.svp = NULL;
781
782 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
783         cx->blk_loop.resetsp = s - PL_stack_base;                       \
784         cx->blk_loop.my_op = cLOOP;                                     \
785         cx->blk_loop.state_u.ary.ary = NULL;                            \
786         cx->blk_loop.state_u.ary.ix = 0;                                \
787         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
788
789 #define POPLOOP(cx)                                                     \
790         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
791             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
792             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
793         }                                                               \
794         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
795             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
796
797 /* given/when context */
798 struct block_givwhen {
799         OP *leave_op;
800 };
801
802 #define PUSHGIVEN(cx)                                                   \
803         cx->blk_givwhen.leave_op = cLOGOP->op_other;
804
805 #define PUSHWHEN PUSHGIVEN
806
807 /* context common to subroutines, evals and loops */
808 struct block {
809     U8          blku_type;      /* what kind of context this is */
810     U8          blku_gimme;     /* is this block running in list context? */
811     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
812     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
813     COP *       blku_oldcop;    /* old curcop pointer */
814     I32         blku_oldmarksp; /* mark stack index */
815     I32         blku_oldscopesp;        /* scope stack index */
816     PMOP *      blku_oldpm;     /* values of pattern match vars */
817
818     union {
819         struct block_sub        blku_sub;
820         struct block_format     blku_format;
821         struct block_eval       blku_eval;
822         struct block_loop       blku_loop;
823         struct block_givwhen    blku_givwhen;
824     } blk_u;
825 };
826 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
827 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
828 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
829 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
830 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
831 #define blk_gimme       cx_u.cx_blk.blku_gimme
832 #define blk_u16         cx_u.cx_blk.blku_u16
833 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
834 #define blk_format      cx_u.cx_blk.blk_u.blku_format
835 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
836 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
837 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
838
839 #define DEBUG_CX(action)                                                \
840     DEBUG_l(                                                            \
841         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
842                     (long)cxstack_ix,                                   \
843                     action,                                             \
844                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
845                     (long)PL_scopestack_ix,                             \
846                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
847                     __FILE__, __LINE__));
848
849 /* Enter a block. */
850 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
851         cx->cx_type             = t,                                    \
852         cx->blk_oldsp           = sp - PL_stack_base,                   \
853         cx->blk_oldcop          = PL_curcop,                            \
854         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
855         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
856         cx->blk_oldpm           = PL_curpm,                             \
857         cx->blk_gimme           = (U8)gimme;                            \
858         DEBUG_CX("PUSH");
859
860 /* Exit a block (RETURN and LAST). */
861 #define POPBLOCK(cx,pm)                                                 \
862         DEBUG_CX("POP");                                                \
863         cx = &cxstack[cxstack_ix--],                                    \
864         newsp            = PL_stack_base + cx->blk_oldsp,               \
865         PL_curcop        = cx->blk_oldcop,                              \
866         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
867         PL_scopestack_ix = cx->blk_oldscopesp,                          \
868         pm               = cx->blk_oldpm,                               \
869         gimme            = cx->blk_gimme;
870
871 /* Continue a block elsewhere (NEXT and REDO). */
872 #define TOPBLOCK(cx)                                                    \
873         DEBUG_CX("TOP");                                                \
874         cx  = &cxstack[cxstack_ix],                                     \
875         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
876         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
877         PL_scopestack_ix = cx->blk_oldscopesp,                          \
878         PL_curpm         = cx->blk_oldpm;
879
880 /* substitution context */
881 struct subst {
882     U8          sbu_type;       /* what kind of context this is */
883     U8          sbu_rflags;
884     U16         sbu_rxtainted;  /* matches struct block */
885     I32         sbu_iters;
886     I32         sbu_maxiters;
887     I32         sbu_oldsave;
888     char *      sbu_orig;
889     SV *        sbu_dstr;
890     SV *        sbu_targ;
891     char *      sbu_s;
892     char *      sbu_m;
893     char *      sbu_strend;
894     void *      sbu_rxres;
895     REGEXP *    sbu_rx;
896 };
897 #define sb_iters        cx_u.cx_subst.sbu_iters
898 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
899 #define sb_rflags       cx_u.cx_subst.sbu_rflags
900 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
901 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
902 #define sb_orig         cx_u.cx_subst.sbu_orig
903 #define sb_dstr         cx_u.cx_subst.sbu_dstr
904 #define sb_targ         cx_u.cx_subst.sbu_targ
905 #define sb_s            cx_u.cx_subst.sbu_s
906 #define sb_m            cx_u.cx_subst.sbu_m
907 #define sb_strend       cx_u.cx_subst.sbu_strend
908 #define sb_rxres        cx_u.cx_subst.sbu_rxres
909 #define sb_rx           cx_u.cx_subst.sbu_rx
910
911 #ifdef PERL_CORE
912 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
913         cx->sb_iters            = iters,                                \
914         cx->sb_maxiters         = maxiters,                             \
915         cx->sb_rflags           = r_flags,                              \
916         cx->sb_oldsave          = oldsave,                              \
917         cx->sb_rxtainted        = rxtainted,                            \
918         cx->sb_orig             = orig,                                 \
919         cx->sb_dstr             = dstr,                                 \
920         cx->sb_targ             = targ,                                 \
921         cx->sb_s                = s,                                    \
922         cx->sb_m                = m,                                    \
923         cx->sb_strend           = strend,                               \
924         cx->sb_rxres            = NULL,                                 \
925         cx->sb_rx               = rx,                                   \
926         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
927         rxres_save(&cx->sb_rxres, rx);                                  \
928         (void)ReREFCNT_inc(rx)
929
930 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
931         rxres_free(&cx->sb_rxres);                                      \
932         ReREFCNT_dec(cx->sb_rx)
933 #endif
934
935 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
936
937 struct context {
938     union {
939         struct block    cx_blk;
940         struct subst    cx_subst;
941     } cx_u;
942 };
943 #define cx_type cx_u.cx_subst.sbu_type
944
945 /* If you re-order these, there is also an array of uppercase names in perl.h
946    and a static array of context names in pp_ctl.c  */
947 #define CXTYPEMASK      0xf
948 #define CXt_NULL        0
949 #define CXt_WHEN        1
950 #define CXt_BLOCK       2
951 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
952    jump table in pp_ctl.c
953    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
954 */
955 #define CXt_GIVEN       3
956 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
957 #define CXt_LOOP_FOR    4
958 #define CXt_LOOP_PLAIN  5
959 #define CXt_LOOP_LAZYSV 6
960 #define CXt_LOOP_LAZYIV 7
961 #define CXt_SUB         8
962 #define CXt_FORMAT      9
963 #define CXt_EVAL       10
964 #define CXt_SUBST      11
965 /* SUBST doesn't feature in all switch statements.  */
966
967 /* private flags for CXt_SUB and CXt_NULL
968    However, this is checked in many places which do not check the type, so
969    this bit needs to be kept clear for most everything else. For reasons I
970    haven't investigated, it can coexist with CXp_FOR_DEF */
971 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
972                                    tear down context on exit). */ 
973
974 /* private flags for CXt_SUB and CXt_FORMAT */
975 #define CXp_HASARGS     0x20
976 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
977 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
978
979 /* private flags for CXt_EVAL */
980 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
981 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
982
983 /* private flags for CXt_LOOP */
984 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
985 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
986 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
987
988 /* private flags for CXt_SUBST */
989 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
990
991 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
992 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
993 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
994                          == CXp_MULTICALL)
995 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
996                          == (CXt_EVAL|CXp_REAL))
997 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
998                          == (CXt_EVAL|CXp_TRYBLOCK))
999 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1000 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1001                          && ((c)->cx_type & CXp_FOR_DEF))
1002
1003 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1004
1005 /* 
1006 =head1 "Gimme" Values
1007 */
1008
1009 /*
1010 =for apidoc AmU||G_SCALAR
1011 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
1012 L<perlcall>.
1013
1014 =for apidoc AmU||G_ARRAY
1015 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
1016 L<perlcall>.
1017
1018 =for apidoc AmU||G_VOID
1019 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
1020
1021 =for apidoc AmU||G_DISCARD
1022 Indicates that arguments returned from a callback should be discarded.  See
1023 L<perlcall>.
1024
1025 =for apidoc AmU||G_EVAL
1026
1027 Used to force a Perl C<eval> wrapper around a callback.  See
1028 L<perlcall>.
1029
1030 =for apidoc AmU||G_NOARGS
1031
1032 Indicates that no arguments are being sent to a callback.  See
1033 L<perlcall>.
1034
1035 =cut
1036 */
1037
1038 #define G_SCALAR        2
1039 #define G_ARRAY         3
1040 #define G_VOID          1
1041 #define G_WANT          3
1042
1043 /* extra flags for Perl_call_* routines */
1044 #define G_DISCARD       4       /* Call FREETMPS.
1045                                    Don't change this without consulting the
1046                                    hash actions codes defined in hv.h */
1047 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1048 #define G_NOARGS       16       /* Don't construct a @_ array. */
1049 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1050 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1051 #define G_METHOD      128       /* Calling method. */
1052 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1053                                    fold_constants. */
1054 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1055                                    A special case for UNSHIFT in
1056                                    Perl_magic_methcall().  */
1057 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1058                                     Perl_magic_methcall().  */
1059 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1060 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1061
1062 /* flag bits for PL_in_eval */
1063 #define EVAL_NULL       0       /* not in an eval */
1064 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1065 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1066 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1067 #define EVAL_INREQUIRE  8       /* The code is being required. */
1068 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1069
1070 /* Support for switching (stack and block) contexts.
1071  * This ensures magic doesn't invalidate local stack and cx pointers.
1072  */
1073
1074 #define PERLSI_UNKNOWN          -1
1075 #define PERLSI_UNDEF            0
1076 #define PERLSI_MAIN             1
1077 #define PERLSI_MAGIC            2
1078 #define PERLSI_SORT             3
1079 #define PERLSI_SIGNAL           4
1080 #define PERLSI_OVERLOAD         5
1081 #define PERLSI_DESTROY          6
1082 #define PERLSI_WARNHOOK         7
1083 #define PERLSI_DIEHOOK          8
1084 #define PERLSI_REQUIRE          9
1085
1086 struct stackinfo {
1087     AV *                si_stack;       /* stack for current runlevel */
1088     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1089     struct stackinfo *  si_prev;
1090     struct stackinfo *  si_next;
1091     I32                 si_cxix;        /* current context index */
1092     I32                 si_cxmax;       /* maximum allocated index */
1093     I32                 si_type;        /* type of runlevel */
1094     I32                 si_markoff;     /* offset where markstack begins for us.
1095                                          * currently used only with DEBUGGING,
1096                                          * but not #ifdef-ed for bincompat */
1097 };
1098
1099 typedef struct stackinfo PERL_SI;
1100
1101 #define cxstack         (PL_curstackinfo->si_cxstack)
1102 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1103 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1104
1105 #ifdef DEBUGGING
1106 #  define       SET_MARK_OFFSET \
1107     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1108 #else
1109 #  define       SET_MARK_OFFSET NOOP
1110 #endif
1111
1112 #define PUSHSTACKi(type) \
1113     STMT_START {                                                        \
1114         PERL_SI *next = PL_curstackinfo->si_next;                       \
1115         DEBUG_l({                                                       \
1116             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1117             while (p) { i++; p = p->si_prev; }                          \
1118             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1119                          i, __FILE__, __LINE__);})                      \
1120         if (!next) {                                                    \
1121             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1122             next->si_prev = PL_curstackinfo;                            \
1123             PL_curstackinfo->si_next = next;                            \
1124         }                                                               \
1125         next->si_type = type;                                           \
1126         next->si_cxix = -1;                                             \
1127         AvFILLp(next->si_stack) = 0;                                    \
1128         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1129         PL_curstackinfo = next;                                         \
1130         SET_MARK_OFFSET;                                                \
1131     } STMT_END
1132
1133 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1134
1135 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1136  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1137 #define POPSTACK \
1138     STMT_START {                                                        \
1139         dSP;                                                            \
1140         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1141         DEBUG_l({                                                       \
1142             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1143             while (p) { i++; p = p->si_prev; }                          \
1144             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1145                          i, __FILE__, __LINE__);})                      \
1146         if (!prev) {                                                    \
1147             Perl_croak_popstack();                                      \
1148         }                                                               \
1149         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1150         /* don't free prev here, free them all at the END{} */          \
1151         PL_curstackinfo = prev;                                         \
1152     } STMT_END
1153
1154 #define POPSTACK_TO(s) \
1155     STMT_START {                                                        \
1156         while (PL_curstack != s) {                                      \
1157             dounwind(-1);                                               \
1158             POPSTACK;                                                   \
1159         }                                                               \
1160     } STMT_END
1161
1162 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1163 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1164
1165 /*
1166 =head1 Multicall Functions
1167
1168 =for apidoc Ams||dMULTICALL
1169 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1170
1171 =for apidoc Ams||PUSH_MULTICALL
1172 Opening bracket for a lightweight callback.
1173 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1174
1175 =for apidoc Ams||MULTICALL
1176 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1177
1178 =for apidoc Ams||POP_MULTICALL
1179 Closing bracket for a lightweight callback.
1180 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1181
1182 =cut
1183 */
1184
1185 #define dMULTICALL \
1186     SV **newsp;                 /* set by POPBLOCK */                   \
1187     PERL_CONTEXT *cx;                                                   \
1188     CV *multicall_cv;                                                   \
1189     OP *multicall_cop;                                                  \
1190     bool multicall_oldcatch;                                            \
1191     U8 hasargs = 0              /* used by PUSHSUB */
1192
1193 #define PUSH_MULTICALL(the_cv) \
1194     PUSH_MULTICALL_FLAGS(the_cv, 0)
1195
1196 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1197  * for the CX stack entry (this isn't part of the public API) */
1198
1199 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1200     STMT_START {                                                        \
1201         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1202         CV * const cv = _nOnclAshIngNamE_;                              \
1203         PADLIST * const padlist = CvPADLIST(cv);                        \
1204         ENTER;                                                          \
1205         multicall_oldcatch = CATCH_GET;                                 \
1206         SAVETMPS; SAVEVPTR(PL_op);                                      \
1207         CATCH_SET(TRUE);                                                \
1208         PUSHSTACKi(PERLSI_SORT);                                        \
1209         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1210         PUSHSUB(cx);                                                    \
1211         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1212             CvDEPTH(cv)++;                                              \
1213         if (CvDEPTH(cv) >= 2) {                                         \
1214             PERL_STACK_OVERFLOW_CHECK();                                \
1215             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1216         }                                                               \
1217         SAVECOMPPAD();                                                  \
1218         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1219         multicall_cv = cv;                                              \
1220         multicall_cop = CvSTART(cv);                                    \
1221     } STMT_END
1222
1223 #define MULTICALL \
1224     STMT_START {                                                        \
1225         PL_op = multicall_cop;                                          \
1226         CALLRUNOPS(aTHX);                                               \
1227     } STMT_END
1228
1229 #define POP_MULTICALL \
1230     STMT_START {                                                        \
1231         cx = &cxstack[cxstack_ix];                                      \
1232         if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {      \
1233                 LEAVESUB(multicall_cv);                                 \
1234         }                                                               \
1235         POPBLOCK(cx,PL_curpm);                                          \
1236         POPSTACK;                                                       \
1237         CATCH_SET(multicall_oldcatch);                                  \
1238         LEAVE;                                                          \
1239         SPAGAIN;                                                        \
1240     } STMT_END
1241
1242 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1243  * (this isn't part of the public API) */
1244
1245 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1246     STMT_START {                                                        \
1247         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1248         CV * const cv = _nOnclAshIngNamE_;                              \
1249         PADLIST * const padlist = CvPADLIST(cv);                        \
1250         cx = &cxstack[cxstack_ix];                                      \
1251         assert(cx->cx_type & CXp_MULTICALL);                            \
1252         if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {      \
1253                 LEAVESUB(multicall_cv);                                 \
1254         }                                                               \
1255         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1256         PUSHSUB(cx);                                                    \
1257         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1258             CvDEPTH(cv)++;                                              \
1259         if (CvDEPTH(cv) >= 2) {                                         \
1260             PERL_STACK_OVERFLOW_CHECK();                                \
1261             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1262         }                                                               \
1263         SAVECOMPPAD();                                                  \
1264         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1265         multicall_cv = cv;                                              \
1266         multicall_cop = CvSTART(cv);                                    \
1267     } STMT_END
1268 /*
1269  * Local variables:
1270  * c-indentation-style: bsd
1271  * c-basic-offset: 4
1272  * indent-tabs-mode: nil
1273  * End:
1274  *
1275  * ex: set ts=8 sts=4 sw=4 et:
1276  */