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[perl5.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are statement separators.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a PL_start_env initialized when perl starts, and
18  * PL_top_env points to this initially, so PL_top_env should always be
19  * non-null.
20  *
21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
23  * null to ensure this).
24  *
25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
26  * establish a local jmpenv to handle exception traps.  Care must be taken
27  * to restore the previous value of je_mustcatch before exiting the
28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
29  * GSAR 97-03-27
30  */
31
32 struct jmpenv {
33     struct jmpenv *     je_prev;
34     Sigjmp_buf          je_buf;         /* uninit if je_prev is NULL */
35     int                 je_ret;         /* last exception thrown */
36     bool                je_mustcatch;   /* need to call longjmp()? */
37     U16                 je_old_delaymagic; /* saved PL_delaymagic */
38 };
39
40 typedef struct jmpenv JMPENV;
41
42 /*
43  * How to build the first jmpenv.
44  *
45  * top_env needs to be non-zero. It points to an area
46  * in which longjmp() stuff is stored, as C callstack
47  * info there at least is thread specific this has to
48  * be per-thread. Otherwise a 'die' in a thread gives
49  * that thread the C stack of last thread to do an eval {}!
50  */
51
52 #define JMPENV_BOOTSTRAP \
53     STMT_START {                                \
54         PERL_POISON_EXPR(PoisonNew(&PL_start_env, 1, JMPENV));\
55         PL_top_env = &PL_start_env;             \
56         PL_start_env.je_prev = NULL;            \
57         PL_start_env.je_ret = -1;               \
58         PL_start_env.je_mustcatch = TRUE;       \
59         PL_start_env.je_old_delaymagic = 0;     \
60     } STMT_END
61
62 /*
63  *   PERL_FLEXIBLE_EXCEPTIONS
64  * 
65  * All the flexible exceptions code has been removed.
66  * See the following threads for details:
67  *
68  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
69  * 
70  * Joshua's original patches (which weren't applied) and discussion:
71  * 
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
74  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
75  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
78  * 
79  * Chip's reworked patch and discussion:
80  * 
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
82  * 
83  * The flaw in these patches (which went unnoticed at the time) was
84  * that they moved some code that could potentially die() out of the
85  * region protected by the setjmp()s.  This caused exceptions within
86  * END blocks and such to not be handled by the correct setjmp().
87  * 
88  * The original patches that introduces flexible exceptions were:
89  *
90  * http://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
91  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a                                        
92  *  
93  */
94
95 #define dJMPENV         JMPENV cur_env
96
97 #define JMPENV_PUSH(v) \
98     STMT_START {                                                        \
99         DEBUG_l({                                                       \
100             int i = 0; JMPENV *p = PL_top_env;                          \
101             while (p) { i++; p = p->je_prev; }                          \
102             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
103                          i,  __FILE__, __LINE__);})                     \
104         cur_env.je_prev = PL_top_env;                                   \
105         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
106         PL_top_env = &cur_env;                                          \
107         cur_env.je_mustcatch = FALSE;                                   \
108         cur_env.je_old_delaymagic = PL_delaymagic;                      \
109         (v) = cur_env.je_ret;                                           \
110     } STMT_END
111
112 #define JMPENV_POP \
113     STMT_START {                                                        \
114         DEBUG_l({                                                       \
115             int i = -1; JMPENV *p = PL_top_env;                         \
116             while (p) { i++; p = p->je_prev; }                          \
117             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
118                          i, __FILE__, __LINE__);})                      \
119         assert(PL_top_env == &cur_env);                                 \
120         PL_delaymagic = cur_env.je_old_delaymagic;                      \
121         PL_top_env = cur_env.je_prev;                                   \
122     } STMT_END
123
124 #define JMPENV_JUMP(v) \
125     STMT_START {                                                \
126         DEBUG_l({                                               \
127             int i = -1; JMPENV *p = PL_top_env;                 \
128             while (p) { i++; p = p->je_prev; }                  \
129             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
130                          (int)v, i, __FILE__, __LINE__);})      \
131         if (PL_top_env->je_prev)                                \
132             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
133         if ((v) == 2)                                           \
134             PerlProc_exit(STATUS_EXIT);                         \
135         PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
136         PerlProc_exit(1);                                       \
137     } STMT_END
138
139 #define CATCH_GET               (PL_top_env->je_mustcatch)
140 #define CATCH_SET(v) \
141     STMT_START {                                                        \
142         DEBUG_l(                                                        \
143             Perl_deb(aTHX_                                              \
144                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
145                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
146                  __FILE__, __LINE__);)                                  \
147         PL_top_env->je_mustcatch = (v);                                 \
148     } STMT_END
149
150 /*
151 =head1 COP Hint Hashes
152 */
153
154 typedef struct refcounted_he COPHH;
155
156 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
157
158 /*
159 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
160
161 Look up the entry in the cop hints hash C<cophh> with the key specified by
162 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
163 the key octets are interpreted as UTF-8, otherwise they are interpreted
164 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
165 it has not been precomputed.  Returns a mortal scalar copy of the value
166 associated with the key, or C<&PL_sv_placeholder> if there is no value
167 associated with the key.
168
169 =cut
170 */
171
172 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
173     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
174
175 /*
176 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
177
178 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
179 string/length pair, and no precomputed hash.
180
181 =cut
182 */
183
184 #define cophh_fetch_pvs(cophh, key, flags) \
185     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
186
187 /*
188 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
189
190 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
191 a string/length pair.
192
193 =cut
194 */
195
196 #define cophh_fetch_pv(cophh, key, hash, flags) \
197     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
198
199 /*
200 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
201
202 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
203 string/length pair.
204
205 =cut
206 */
207
208 #define cophh_fetch_sv(cophh, key, hash, flags) \
209     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
210
211 /*
212 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
213
214 Generates and returns a standard Perl hash representing the full set of
215 key/value pairs in the cop hints hash C<cophh>.  C<flags> is currently
216 unused and must be zero.
217
218 =cut
219 */
220
221 #define cophh_2hv(cophh, flags) \
222     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
223
224 /*
225 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
226
227 Make and return a complete copy of the cop hints hash C<cophh>.
228
229 =cut
230 */
231
232 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
233
234 /*
235 =for apidoc Amx|void|cophh_free|COPHH *cophh
236
237 Discard the cop hints hash C<cophh>, freeing all resources associated
238 with it.
239
240 =cut
241 */
242
243 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
244
245 /*
246 =for apidoc Amx|COPHH *|cophh_new_empty
247
248 Generate and return a fresh cop hints hash containing no entries.
249
250 =cut
251 */
252
253 #define cophh_new_empty() ((COPHH *)NULL)
254
255 /*
256 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
257
258 Stores a value, associated with a key, in the cop hints hash C<cophh>,
259 and returns the modified hash.  The returned hash pointer is in general
260 not the same as the hash pointer that was passed in.  The input hash is
261 consumed by the function, and the pointer to it must not be subsequently
262 used.  Use L</cophh_copy> if you need both hashes.
263
264 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
265 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
266 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
267 hash of the key string, or zero if it has not been precomputed.
268
269 C<value> is the scalar value to store for this key.  C<value> is copied
270 by this function, which thus does not take ownership of any reference
271 to it, and later changes to the scalar will not be reflected in the
272 value visible in the cop hints hash.  Complex types of scalar will not
273 be stored with referential integrity, but will be coerced to strings.
274
275 =cut
276 */
277
278 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
279     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
280
281 /*
282 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
283
284 Like L</cophh_store_pvn>, but takes a literal string instead of a
285 string/length pair, and no precomputed hash.
286
287 =cut
288 */
289
290 #define cophh_store_pvs(cophh, key, value, flags) \
291     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
292
293 /*
294 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
295
296 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
297 a string/length pair.
298
299 =cut
300 */
301
302 #define cophh_store_pv(cophh, key, hash, value, flags) \
303     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
304
305 /*
306 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
307
308 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
309 string/length pair.
310
311 =cut
312 */
313
314 #define cophh_store_sv(cophh, key, hash, value, flags) \
315     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
316
317 /*
318 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
319
320 Delete a key and its associated value from the cop hints hash C<cophh>,
321 and returns the modified hash.  The returned hash pointer is in general
322 not the same as the hash pointer that was passed in.  The input hash is
323 consumed by the function, and the pointer to it must not be subsequently
324 used.  Use L</cophh_copy> if you need both hashes.
325
326 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
327 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
328 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
329 hash of the key string, or zero if it has not been precomputed.
330
331 =cut
332 */
333
334 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
335     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
336         (SV *)NULL, flags)
337
338 /*
339 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
340
341 Like L</cophh_delete_pvn>, but takes a literal string instead of a
342 string/length pair, and no precomputed hash.
343
344 =cut
345 */
346
347 #define cophh_delete_pvs(cophh, key, flags) \
348     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
349         (SV *)NULL, flags)
350
351 /*
352 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
353
354 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
355 a string/length pair.
356
357 =cut
358 */
359
360 #define cophh_delete_pv(cophh, key, hash, flags) \
361     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
362
363 /*
364 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
365
366 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
367 string/length pair.
368
369 =cut
370 */
371
372 #define cophh_delete_sv(cophh, key, hash, flags) \
373     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
374
375 #include "mydtrace.h"
376
377 struct cop {
378     BASEOP
379     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
380        an exact multiple of 8 bytes to save structure padding.  */
381     line_t      cop_line;       /* line # of this command */
382     /* label for this construct is now stored in cop_hints_hash */
383 #ifdef USE_ITHREADS
384     PADOFFSET   cop_stashoff;   /* offset into PL_stashpad, for the
385                                    package the line was compiled in */
386     char *      cop_file;       /* file name the following line # is from */
387 #else
388     HV *        cop_stash;      /* package line was compiled in */
389     GV *        cop_filegv;     /* file the following line # is from */
390 #endif
391     U32         cop_hints;      /* hints bits from pragmata */
392     U32         cop_seq;        /* parse sequence number */
393     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
394     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
395     /* compile time state of %^H.  See the comment in op.c for how this is
396        used to recreate a hash to return from caller.  */
397     COPHH *     cop_hints_hash;
398 };
399
400 #ifdef USE_ITHREADS
401 #  define CopFILE(c)            ((c)->cop_file)
402 #  define CopFILEGV(c)          (CopFILE(c) \
403                                  ? gv_fetchfile(CopFILE(c)) : NULL)
404                                  
405 #  ifdef NETWARE
406 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
407 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepvn((pv),(l)))
408 #  else
409 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
410 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
411 #  endif
412
413 #  define CopFILESV(c)          (CopFILE(c) \
414                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
415 #  define CopFILEAV(c)          (CopFILE(c) \
416                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
417 #  define CopFILEAVx(c)         (assert_(CopFILE(c)) \
418                                    GvAV(gv_fetchfile(CopFILE(c))))
419
420 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
421 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
422                                     ? alloccopstash(hv)                 \
423                                     : 0)
424 #  ifdef NETWARE
425 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
426 #  else
427 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
428 #  endif
429 #else
430 #  define CopFILEGV(c)          ((c)->cop_filegv)
431 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
432 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
433 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
434 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
435 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
436 #  ifdef DEBUGGING
437 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
438 #  else
439 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
440 # endif
441 #  define CopFILE(c)            (CopFILEGV(c) \
442                                     ? GvNAME(CopFILEGV(c))+2 : NULL)
443 #  define CopSTASH(c)           ((c)->cop_stash)
444 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
445 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
446
447 #endif /* USE_ITHREADS */
448
449 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
450    /* cop_stash is not refcounted */
451 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
452 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
453
454 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
455 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
456
457 /*
458 =head1 COP Hint Reading
459 */
460
461 /*
462 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
463
464 Look up the hint entry in the cop C<cop> with the key specified by
465 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
466 the key octets are interpreted as UTF-8, otherwise they are interpreted
467 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
468 it has not been precomputed.  Returns a mortal scalar copy of the value
469 associated with the key, or C<&PL_sv_placeholder> if there is no value
470 associated with the key.
471
472 =cut
473 */
474
475 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
476     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
477
478 /*
479 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
480
481 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
482 string/length pair, and no precomputed hash.
483
484 =cut
485 */
486
487 #define cop_hints_fetch_pvs(cop, key, flags) \
488     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
489
490 /*
491 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
492
493 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
494 of a string/length pair.
495
496 =cut
497 */
498
499 #define cop_hints_fetch_pv(cop, key, hash, flags) \
500     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
501
502 /*
503 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
504
505 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
506 string/length pair.
507
508 =cut
509 */
510
511 #define cop_hints_fetch_sv(cop, key, hash, flags) \
512     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
513
514 /*
515 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
516
517 Generates and returns a standard Perl hash representing the full set of
518 hint entries in the cop C<cop>.  C<flags> is currently unused and must
519 be zero.
520
521 =cut
522 */
523
524 #define cop_hints_2hv(cop, flags) \
525     cophh_2hv(CopHINTHASH_get(cop), flags)
526
527 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
528 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
529 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
530 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
531
532 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
533 #define CopLINE(c)              ((c)->cop_line)
534 #define CopLINE_inc(c)          (++CopLINE(c))
535 #define CopLINE_dec(c)          (--CopLINE(c))
536 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
537
538 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
539 #define OutCopFILE(c) CopFILE(c)
540
541 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
542 #define CopHINTS_set(c, h)      STMT_START {                            \
543                                     (c)->cop_hints = (h);               \
544                                 } STMT_END
545
546 /*
547  * Here we have some enormously heavy (or at least ponderous) wizardry.
548  */
549
550 /* subroutine context */
551 struct block_sub {
552     OP *        retop;  /* op to execute on exit from sub */
553     /* Above here is the same for sub, format and eval.  */
554     PAD         *prevcomppad; /* the caller's PL_comppad */
555     CV *        cv;
556     /* Above here is the same for sub and format.  */
557     I32         olddepth;
558     AV          *savearray;
559 };
560
561
562 /* format context */
563 struct block_format {
564     OP *        retop;  /* op to execute on exit from sub */
565     /* Above here is the same for sub, format and eval.  */
566     PAD         *prevcomppad; /* the caller's PL_comppad */
567     CV *        cv;
568     /* Above here is the same for sub and format.  */
569     GV *        gv;
570     GV *        dfoutgv;
571 };
572
573 /* return a pointer to the current context */
574
575 #define CX_CUR() (&cxstack[cxstack_ix])
576
577 /* free all savestack items back to the watermark of the specified context */
578
579 #define CX_LEAVE_SCOPE(cx) LEAVE_SCOPE(cx->blk_oldsaveix)
580
581 #ifdef DEBUGGING
582 /* on debugging builds, poison cx afterwards so we know no code
583  * uses it - because after doing cxstack_ix--, any ties, exceptions etc
584  * may overwrite the current stack frame */
585 #  define CX_POP(cx)                                                   \
586         assert(CX_CUR() == cx);                                        \
587         cxstack_ix--;                                                  \
588         cx = NULL;
589 #else
590 #  define CX_POP(cx) cxstack_ix--;
591 #endif
592
593
594 /* base for the next two macros. Don't use directly.
595  * The context frame holds a reference to the CV so that it can't be
596  * freed while we're executing it */
597
598 #define CX_PUSHSUB_BASE(cx, cv, op, hasargs)                            \
599         ENTRY_PROBE(CvNAMED(cv)                                         \
600                         ? HEK_KEY(CvNAME_HEK(cv))                       \
601                         : GvENAME(CvGV(cv)),                            \
602                 CopFILE((const COP *)CvSTART(cv)),                      \
603                 CopLINE((const COP *)CvSTART(cv)),                      \
604                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
605                                                                         \
606         cx->blk_sub.cv = cv;                                            \
607         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
608         cx->blk_sub.prevcomppad = PL_comppad;                           \
609         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
610         cx->blk_sub.retop = op;                                         \
611         SvREFCNT_inc_simple_void_NN(cv);
612
613 #define CX_PUSHSUB_GET_LVALUE_MASK(func) \
614         /* If the context is indeterminate, then only the lvalue */     \
615         /* flags that the caller also has are applicable.        */     \
616         (                                                               \
617            (PL_op->op_flags & OPf_WANT)                                 \
618                ? OPpENTERSUB_LVAL_MASK                                  \
619                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
620                    ? 0 : (U8)func(aTHX)                                 \
621         )
622
623 #define CX_PUSHSUB(cx, cv, op, hasargs)                                 \
624     {                                                                   \
625         U8 phlags = CX_PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);    \
626         CX_PUSHSUB_BASE(cx, cv, op, hasargs)                            \
627         cx->blk_u16 = PL_op->op_private &                               \
628                           (phlags|OPpDEREF);                            \
629     }
630
631 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
632 #define CX_PUSHSUB_DB(cx, cv, op, hasargs)                              \
633         CX_PUSHSUB_BASE(cx, cv, op, hasargs)                            \
634         cx->blk_u16 = 0;
635
636
637 #define CX_PUSHFORMAT(cx, cv, gv, retop)                                \
638         cx->blk_format.cv = cv;                                         \
639         cx->blk_format.gv = gv;                                         \
640         cx->blk_format.retop = (retop);                                 \
641         cx->blk_format.dfoutgv = PL_defoutgv;                           \
642         cx->blk_format.prevcomppad = PL_comppad;                        \
643         cx->blk_u16 = 0;                                                \
644         SvREFCNT_inc_simple_void_NN(cv);                                \
645         CvDEPTH(cv)++;                                                  \
646         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
647
648 /* Restore old @_ */
649 #define CX_POP_SAVEARRAY(cx)                                            \
650     STMT_START {                                                        \
651         AV *av = GvAV(PL_defgv);                                        \
652         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
653         cx->blk_sub.savearray = NULL;                                   \
654         SvREFCNT_dec(av);                                               \
655     } STMT_END
656
657 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
658  * leave any (a fast av_clear(ary), basically) */
659 #define CLEAR_ARGARRAY(ary) \
660     STMT_START {                                                        \
661         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
662         AvARRAY(ary) = AvALLOC(ary);                                    \
663         AvFILLp(ary) = -1;                                              \
664     } STMT_END
665
666
667 /* subsets of CX_POPSUB */
668
669 #define CX_POPSUB_COMMON(cx) \
670     STMT_START {                                                        \
671         CV *cv;                                                         \
672         assert(CxTYPE(cx) == CXt_SUB);                                  \
673         PL_comppad = cx->blk_sub.prevcomppad;                           \
674         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
675         cv = cx->blk_sub.cv;                                            \
676         CvDEPTH(cv) = cx->blk_sub.olddepth;                             \
677         cx->blk_sub.cv = NULL;                                          \
678         SvREFCNT_dec(cv);                                               \
679     } STMT_END
680
681 /* handle the @_ part of leaving a sub */
682
683 #define CX_POPSUB_ARGS(cx) \
684     STMT_START {                                                        \
685         AV *av;                                                         \
686         assert(CxTYPE(cx) == CXt_SUB);                                  \
687         assert(AvARRAY(MUTABLE_AV(                                      \
688             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
689                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
690         CX_POP_SAVEARRAY(cx);                                           \
691         av = MUTABLE_AV(PAD_SVl(0));                                    \
692         if (UNLIKELY(AvREAL(av)))                                       \
693             /* abandon @_ if it got reified */                          \
694             clear_defarray(av, 0);                                      \
695         else {                                                          \
696             CLEAR_ARGARRAY(av);                                         \
697         }                                                               \
698     } STMT_END
699
700 #define CX_POPSUB(cx)                                                   \
701     STMT_START {                                                        \
702         assert(CxTYPE(cx) == CXt_SUB);                                  \
703         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
704                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
705                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
706                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
707                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
708                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
709                                                                         \
710         if (CxHASARGS(cx)) {                                            \
711             CX_POPSUB_ARGS(cx);                                         \
712         }                                                               \
713         CX_POPSUB_COMMON(cx);                                           \
714     } STMT_END
715
716 #define CX_POPFORMAT(cx)                                                \
717     STMT_START {                                                        \
718         CV *cv;                                                         \
719         GV * const dfout = cx->blk_format.dfoutgv;                      \
720         assert(CxTYPE(cx) == CXt_FORMAT);                               \
721         setdefout(dfout);                                               \
722         cx->blk_format.dfoutgv = NULL;                                  \
723         SvREFCNT_dec_NN(dfout); /* the cx->defoutgv ref */              \
724         PL_comppad = cx->blk_format.prevcomppad;                        \
725         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
726         cv = cx->blk_format.cv;                                         \
727         cx->blk_format.cv = NULL;;                                      \
728         --CvDEPTH(cv);                                                  \
729         SvREFCNT_dec_NN(cv);                                            \
730     } STMT_END
731
732 /* eval context */
733 struct block_eval {
734     OP *        retop;  /* op to execute on exit from eval */
735     /* Above here is the same for sub, format and eval.  */
736     SV *        old_namesv;
737     OP *        old_eval_root;
738     SV *        cur_text;
739     CV *        cv;
740     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
741 };
742
743 /* If we ever need more than 512 op types, change the shift from 7.
744    blku_gimme is actually also only 2 bits, so could be merged with something.
745 */
746
747 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
748 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
749
750 #define CX_PUSHEVAL(cx, op, n)                                          \
751     STMT_START {                                                        \
752         assert(!(PL_in_eval & ~0x7F));                                  \
753         assert(!(PL_op->op_type & ~0x1FF));                             \
754         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
755         cx->blk_eval.old_namesv = (n);                                  \
756         cx->blk_eval.old_eval_root = PL_eval_root;                      \
757         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
758         cx->blk_eval.cv = NULL; /* set by doeval_compile() as applicable */ \
759         cx->blk_eval.retop = op;                                        \
760         cx->blk_eval.cur_top_env = PL_top_env;                          \
761     } STMT_END
762
763 #define CX_POPEVAL(cx)                                                  \
764     STMT_START {                                                        \
765         SV *sv;                                                         \
766         assert(CxTYPE(cx) == CXt_EVAL);                                 \
767         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
768         PL_eval_root = cx->blk_eval.old_eval_root;                      \
769         sv = cx->blk_eval.cur_text;                                     \
770         if (sv && SvSCREAM(sv)) {                                       \
771             cx->blk_eval.cur_text = NULL;                               \
772             SvREFCNT_dec_NN(sv);                                        \
773         }                                                               \
774         sv = cx->blk_eval.old_namesv;                                   \
775         if (sv && !SvTEMP(sv))/* TEMP implies CX_POPEVAL re-entrantly called */ \
776             sv_2mortal(sv);                                             \
777     } STMT_END
778
779 /* loop context */
780 struct block_loop {
781     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
782     union {     /* different ways of locating the iteration variable */
783         SV      **svp; /* for lexicals: address of pad slot */
784         GV      *gv;   /* for package vars */
785     } itervar_u;
786     SV          *itersave; /* the original iteration var */
787     union {
788         struct { /* CXt_LOOP_ARY, C<for (@ary)>  */
789             AV *ary; /* array being iterated over */
790             IV  ix;   /* index relative to base of array */
791         } ary;
792         struct { /* CXt_LOOP_LIST, C<for (list)> */
793             I32 basesp; /* first element of list on stack */
794             IV  ix;      /* index relative to basesp */
795         } stack;
796         struct { /* CXt_LOOP_LAZYIV, C<for (1..9)> */
797             IV cur;
798             IV end;
799         } lazyiv;
800         struct { /* CXt_LOOP_LAZYSV C<for ('a'..'z')> */
801             SV * cur;
802             SV * end; /* maxiumum value (or minimum in reverse) */
803         } lazysv;
804     } state_u;
805 #ifdef USE_ITHREADS
806     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
807 #endif
808 };
809
810 #define CxITERVAR(c)                                    \
811         (CxPADLOOP(c)                                   \
812             ? (c)->blk_loop.itervar_u.svp               \
813             : ((c)->cx_type & CXp_FOR_GV)               \
814                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
815                 : (SV **)&(c)->blk_loop.itervar_u.gv)
816
817 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
818 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
819 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
820 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
821
822 /* CxLVAL(): the lval flags of the call site: the relevant flag bits from
823  * the op_private field of the calling pp_entersub (or its caller's caller
824  * if the caller's lvalue context isn't known):
825  *  OPpLVAL_INTRO:  sub used in lvalue context, e.g. f() = 1;
826  *  OPpENTERSUB_INARGS (in conjunction with OPpLVAL_INTRO): the
827  *      function is being used as a sub arg or as a referent, e.g.
828  *      g(...,f(),...)  or $r = \f()
829  *  OPpDEREF: 2-bit mask indicating e.g. f()->[0].
830  *  Note the contrast with CvLVALUE(), which is a property of the sub
831  *  rather than the call site.
832  */
833 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
834
835
836 #define CX_PUSHLOOP_PLAIN(cx)                                           \
837         cx->blk_loop.my_op = cLOOP;
838
839 #ifdef USE_ITHREADS
840 #  define CX_PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
841 #else
842 #  define CX_PUSHLOOP_FOR_setpad(c) NOOP
843 #endif
844
845 #define CX_PUSHLOOP_FOR(cx, ivar, isave)                                \
846         CX_PUSHLOOP_PLAIN(cx);                                          \
847         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
848         cx->blk_loop.itersave = isave;                                  \
849         CX_PUSHLOOP_FOR_setpad(cx);
850
851 #define CX_POPLOOP(cx)                                                  \
852         assert(CxTYPE_is_LOOP(cx));                                     \
853         if (  CxTYPE(cx) == CXt_LOOP_ARY                                \
854            || CxTYPE(cx) == CXt_LOOP_LAZYSV)                            \
855         {                                                               \
856             /* Free ary or cur. This assumes that state_u.ary.ary       \
857              * aligns with state_u.lazysv.cur. See cx_dup() */          \
858             SV *sv = cx->blk_loop.state_u.lazysv.cur;                   \
859             cx->blk_loop.state_u.lazysv.cur = NULL;                     \
860             SvREFCNT_dec_NN(sv);                                        \
861             if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                        \
862                 sv = cx->blk_loop.state_u.lazysv.end;                   \
863                 cx->blk_loop.state_u.lazysv.end = NULL;                 \
864                 SvREFCNT_dec_NN(sv);                                    \
865             }                                                           \
866         }                                                               \
867         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
868             SV *cursv;                                                  \
869             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
870             if ((cx->cx_type & CXp_FOR_GV))                             \
871                 svp = &GvSV((GV*)svp);                                  \
872             cursv = *svp;                                               \
873             *svp = cx->blk_loop.itersave;                               \
874             cx->blk_loop.itersave = NULL;                               \
875             SvREFCNT_dec(cursv);                                        \
876         }
877
878 /* given/when context */
879 struct block_givwhen {
880         OP *leave_op;
881         SV *defsv_save; /* the original $_ */
882 };
883
884 #define CX_PUSHWHEN(cx)                                                 \
885         cx->blk_givwhen.leave_op = cLOGOP->op_other;
886
887 #define CX_PUSHGIVEN(cx, orig_var)                                      \
888         CX_PUSHWHEN(cx);                                                \
889         cx->blk_givwhen.defsv_save = orig_var;
890
891 #define CX_POPWHEN(cx)                                                  \
892         assert(CxTYPE(cx) == CXt_WHEN);                                 \
893         NOOP;
894
895 #define CX_POPGIVEN(cx)                                                 \
896     STMT_START {                                                        \
897         SV *sv = GvSV(PL_defgv);                                        \
898         assert(CxTYPE(cx) == CXt_GIVEN);                                \
899         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;                    \
900         cx->blk_givwhen.defsv_save = NULL;                              \
901         SvREFCNT_dec(sv);                                               \
902     } STMT_END
903
904
905
906 /* context common to subroutines, evals and loops */
907 struct block {
908     U8          blku_type;      /* what kind of context this is */
909     U8          blku_gimme;     /* is this block running in list context? */
910     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
911     I32         blku_oldsaveix; /* saved PL_savestack_ix */
912     /* all the fields above must be aligned with same-sized fields as sbu */
913     I32         blku_oldsp;     /* current sp floor: where nextstate pops to */
914     I32         blku_oldmarksp; /* mark stack index */
915     COP *       blku_oldcop;    /* old curcop pointer */
916     PMOP *      blku_oldpm;     /* values of pattern match vars */
917     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
918     I32         blku_oldscopesp;        /* scope stack index */
919
920     union {
921         struct block_sub        blku_sub;
922         struct block_format     blku_format;
923         struct block_eval       blku_eval;
924         struct block_loop       blku_loop;
925         struct block_givwhen    blku_givwhen;
926     } blk_u;
927 };
928 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
929 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
930 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
931 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
932 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
933 #define blk_gimme       cx_u.cx_blk.blku_gimme
934 #define blk_u16         cx_u.cx_blk.blku_u16
935 #define blk_oldsaveix   cx_u.cx_blk.blku_oldsaveix
936 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
937 #define blk_format      cx_u.cx_blk.blk_u.blku_format
938 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
939 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
940 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
941
942 #define CX_DEBUG(cx, action)                                            \
943     DEBUG_l(                                                            \
944         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
945                     (long)cxstack_ix,                                   \
946                     action,                                             \
947                     PL_block_type[CxTYPE(cx)],                          \
948                     (long)PL_scopestack_ix,                             \
949                     (long)(cx->blk_oldscopesp),                         \
950                     (long)PL_savestack_ix,                              \
951                     (long)(cx->blk_oldsaveix),                          \
952                     __FILE__, __LINE__));
953
954
955
956 /* substitution context */
957 struct subst {
958     U8          sbu_type;       /* same as blku_type */
959     U8          sbu_rflags;
960     U16         sbu_rxtainted;
961     I32         sbu_oldsaveix; /* same as blku_oldsaveix */
962     /* all the fields above must be aligned with same-sized fields as blk_u */
963     SSize_t     sbu_iters;
964     SSize_t     sbu_maxiters;
965     char *      sbu_orig;
966     SV *        sbu_dstr;
967     SV *        sbu_targ;
968     char *      sbu_s;
969     char *      sbu_m;
970     char *      sbu_strend;
971     void *      sbu_rxres;
972     REGEXP *    sbu_rx;
973 };
974 #define sb_iters        cx_u.cx_subst.sbu_iters
975 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
976 #define sb_rflags       cx_u.cx_subst.sbu_rflags
977 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
978 #define sb_orig         cx_u.cx_subst.sbu_orig
979 #define sb_dstr         cx_u.cx_subst.sbu_dstr
980 #define sb_targ         cx_u.cx_subst.sbu_targ
981 #define sb_s            cx_u.cx_subst.sbu_s
982 #define sb_m            cx_u.cx_subst.sbu_m
983 #define sb_strend       cx_u.cx_subst.sbu_strend
984 #define sb_rxres        cx_u.cx_subst.sbu_rxres
985 #define sb_rx           cx_u.cx_subst.sbu_rx
986
987 #ifdef PERL_CORE
988 #  define CX_PUSHSUBST(cx) CXINC, cx = CX_CUR(),                        \
989         cx->blk_oldsaveix = oldsave,                                    \
990         cx->sb_iters            = iters,                                \
991         cx->sb_maxiters         = maxiters,                             \
992         cx->sb_rflags           = r_flags,                              \
993         cx->sb_rxtainted        = rxtainted,                            \
994         cx->sb_orig             = orig,                                 \
995         cx->sb_dstr             = dstr,                                 \
996         cx->sb_targ             = targ,                                 \
997         cx->sb_s                = s,                                    \
998         cx->sb_m                = m,                                    \
999         cx->sb_strend           = strend,                               \
1000         cx->sb_rxres            = NULL,                                 \
1001         cx->sb_rx               = rx,                                   \
1002         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1003         rxres_save(&cx->sb_rxres, rx);                                  \
1004         (void)ReREFCNT_inc(rx);                                         \
1005         SvREFCNT_inc_void_NN(targ)
1006
1007 #  define CX_POPSUBST(cx) \
1008     STMT_START {                                                        \
1009         REGEXP *re;                                                     \
1010         assert(CxTYPE(cx) == CXt_SUBST);                                \
1011         rxres_free(&cx->sb_rxres);                                      \
1012         re = cx->sb_rx;                                                 \
1013         cx->sb_rx = NULL;                                               \
1014         ReREFCNT_dec(re);                                               \
1015         SvREFCNT_dec_NN(cx->sb_targ);                                   \
1016     } STMT_END
1017 #endif
1018
1019 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1020
1021 struct context {
1022     union {
1023         struct block    cx_blk;
1024         struct subst    cx_subst;
1025     } cx_u;
1026 };
1027 #define cx_type cx_u.cx_subst.sbu_type
1028
1029 /* If you re-order these, there is also an array of uppercase names in perl.h
1030    and a static array of context names in pp_ctl.c  */
1031 #define CXTYPEMASK      0xf
1032 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1033 #define CXt_WHEN        1
1034 #define CXt_BLOCK       2
1035 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1036    jump table in pp_ctl.c
1037    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1038 */
1039 #define CXt_GIVEN       3
1040
1041 /* be careful of the ordering of these five. Macros like CxTYPE_is_LOOP,
1042  * CxFOREACH compare ranges */
1043 #define CXt_LOOP_ARY    4 /* for (@ary)     {} */
1044 #define CXt_LOOP_LAZYSV 5 /* for ('a'..'z') {} */
1045 #define CXt_LOOP_LAZYIV 6 /* for (1..9)     {} */
1046 #define CXt_LOOP_LIST   7 /* for (1,2,3)    {} */
1047 #define CXt_LOOP_PLAIN  8 /*                {} */
1048
1049 #define CXt_SUB         9
1050 #define CXt_FORMAT     10
1051 #define CXt_EVAL       11
1052 #define CXt_SUBST      12
1053 /* SUBST doesn't feature in all switch statements.  */
1054
1055 /* private flags for CXt_SUB and CXt_FORMAT */
1056 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1057                                    context on exit). (not 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
1068 /* this is only set in conjunction with CXp_FOR_GV */
1069 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1070 /* these 3 are mutually exclusive */
1071 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1072 #define CXp_FOR_GV      0x40    /* foreach using package var */
1073 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1074
1075 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1076
1077 /* private flags for CXt_SUBST */
1078 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1079
1080 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1081 #define CxTYPE_is_LOOP(c) (   CxTYPE(cx) >= CXt_LOOP_ARY                \
1082                            && CxTYPE(cx) <= CXt_LOOP_PLAIN)
1083 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1084 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1085                          == (CXt_EVAL|CXp_REAL))
1086 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1087                          == (CXt_EVAL|CXp_TRYBLOCK))
1088 #define CxFOREACH(c)    (   CxTYPE(cx) >= CXt_LOOP_ARY                  \
1089                          && CxTYPE(cx) <= CXt_LOOP_LIST)
1090
1091 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1092
1093 /* 
1094 =head1 "Gimme" Values
1095 */
1096
1097 /*
1098 =for apidoc AmU||G_SCALAR
1099 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1100 L<perlcall>.
1101
1102 =for apidoc AmU||G_ARRAY
1103 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1104 L<perlcall>.
1105
1106 =for apidoc AmU||G_VOID
1107 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1108
1109 =for apidoc AmU||G_DISCARD
1110 Indicates that arguments returned from a callback should be discarded.  See
1111 L<perlcall>.
1112
1113 =for apidoc AmU||G_EVAL
1114
1115 Used to force a Perl C<eval> wrapper around a callback.  See
1116 L<perlcall>.
1117
1118 =for apidoc AmU||G_NOARGS
1119
1120 Indicates that no arguments are being sent to a callback.  See
1121 L<perlcall>.
1122
1123 =cut
1124 */
1125
1126 #define G_SCALAR        2
1127 #define G_ARRAY         3
1128 #define G_VOID          1
1129 #define G_WANT          3
1130
1131 /* extra flags for Perl_call_* routines */
1132 #define G_DISCARD       4       /* Call FREETMPS.
1133                                    Don't change this without consulting the
1134                                    hash actions codes defined in hv.h */
1135 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1136 #define G_NOARGS       16       /* Don't construct a @_ array. */
1137 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1138 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1139 #define G_METHOD      128       /* Calling method. */
1140 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1141                                    fold_constants. */
1142 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1143                                    A special case for UNSHIFT in
1144                                    Perl_magic_methcall().  */
1145 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1146                                     Perl_magic_methcall().  */
1147 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1148 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1149
1150 /* flag bits for PL_in_eval */
1151 #define EVAL_NULL       0       /* not in an eval */
1152 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1153 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1154 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1155 #define EVAL_INREQUIRE  8       /* The code is being required. */
1156 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1157
1158 /* Support for switching (stack and block) contexts.
1159  * This ensures magic doesn't invalidate local stack and cx pointers.
1160  */
1161
1162 #define PERLSI_UNKNOWN          -1
1163 #define PERLSI_UNDEF            0
1164 #define PERLSI_MAIN             1
1165 #define PERLSI_MAGIC            2
1166 #define PERLSI_SORT             3
1167 #define PERLSI_SIGNAL           4
1168 #define PERLSI_OVERLOAD         5
1169 #define PERLSI_DESTROY          6
1170 #define PERLSI_WARNHOOK         7
1171 #define PERLSI_DIEHOOK          8
1172 #define PERLSI_REQUIRE          9
1173 #define PERLSI_MULTICALL       10
1174
1175 struct stackinfo {
1176     AV *                si_stack;       /* stack for current runlevel */
1177     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1178     struct stackinfo *  si_prev;
1179     struct stackinfo *  si_next;
1180     I32                 si_cxix;        /* current context index */
1181     I32                 si_cxmax;       /* maximum allocated index */
1182     I32                 si_type;        /* type of runlevel */
1183     I32                 si_markoff;     /* offset where markstack begins for us.
1184                                          * currently used only with DEBUGGING,
1185                                          * but not #ifdef-ed for bincompat */
1186 };
1187
1188 typedef struct stackinfo PERL_SI;
1189
1190 #define cxstack         (PL_curstackinfo->si_cxstack)
1191 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1192 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1193
1194 #ifdef DEBUGGING
1195 #  define       SET_MARK_OFFSET \
1196     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1197 #else
1198 #  define       SET_MARK_OFFSET NOOP
1199 #endif
1200
1201 #define PUSHSTACKi(type) \
1202     STMT_START {                                                        \
1203         PERL_SI *next = PL_curstackinfo->si_next;                       \
1204         DEBUG_l({                                                       \
1205             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1206             while (p) { i++; p = p->si_prev; }                          \
1207             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1208                          i, __FILE__, __LINE__);})                      \
1209         if (!next) {                                                    \
1210             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1211             next->si_prev = PL_curstackinfo;                            \
1212             PL_curstackinfo->si_next = next;                            \
1213         }                                                               \
1214         next->si_type = type;                                           \
1215         next->si_cxix = -1;                                             \
1216         AvFILLp(next->si_stack) = 0;                                    \
1217         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1218         PL_curstackinfo = next;                                         \
1219         SET_MARK_OFFSET;                                                \
1220     } STMT_END
1221
1222 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1223
1224 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1225  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1226 #define POPSTACK \
1227     STMT_START {                                                        \
1228         dSP;                                                            \
1229         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1230         DEBUG_l({                                                       \
1231             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1232             while (p) { i++; p = p->si_prev; }                          \
1233             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1234                          i, __FILE__, __LINE__);})                      \
1235         if (!prev) {                                                    \
1236             Perl_croak_popstack();                                      \
1237         }                                                               \
1238         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1239         /* don't free prev here, free them all at the END{} */          \
1240         PL_curstackinfo = prev;                                         \
1241     } STMT_END
1242
1243 #define POPSTACK_TO(s) \
1244     STMT_START {                                                        \
1245         while (PL_curstack != s) {                                      \
1246             dounwind(-1);                                               \
1247             POPSTACK;                                                   \
1248         }                                                               \
1249     } STMT_END
1250
1251 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1252 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1253
1254
1255
1256
1257 /*
1258 =head1 Multicall Functions
1259
1260 =for apidoc Ams||dMULTICALL
1261 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1262
1263 =for apidoc Ams||PUSH_MULTICALL
1264 Opening bracket for a lightweight callback.
1265 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1266
1267 =for apidoc Ams||MULTICALL
1268 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1269
1270 =for apidoc Ams||POP_MULTICALL
1271 Closing bracket for a lightweight callback.
1272 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1273
1274 =cut
1275 */
1276
1277 #define dMULTICALL \
1278     SV **newsp;                 /* set by cx_popblock */                \
1279     PERL_CONTEXT *cx;                                                   \
1280     CV *multicall_cv;                                                   \
1281     OP *multicall_cop;                                                  \
1282     bool multicall_oldcatch;                                            \
1283     I32 saveix_floor;                                                   \
1284     U8 hasargs = 0              /* used by CX_PUSHSUB */
1285
1286 #define PUSH_MULTICALL(the_cv) \
1287     PUSH_MULTICALL_FLAGS(the_cv, 0)
1288
1289 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1290  * for the CX stack entry (this isn't part of the public API) */
1291
1292 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1293     STMT_START {                                                        \
1294         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1295         CV * const cv = _nOnclAshIngNamE_;                              \
1296         PADLIST * const padlist = CvPADLIST(cv);                        \
1297         multicall_oldcatch = CATCH_GET;                                 \
1298         CATCH_SET(TRUE);                                                \
1299         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1300         cx = cx_pushblock((CXt_SUB|CXp_MULTICALL|flags), gimme,         \
1301                   PL_stack_sp, PL_savestack_ix);                        \
1302         CX_PUSHSUB(cx, cv, NULL, hasargs);                              \
1303         SAVEOP();                                                       \
1304         saveix_floor = PL_savestack_ix;                                 \
1305         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1306             CvDEPTH(cv)++;                                              \
1307         if (CvDEPTH(cv) >= 2)                                           \
1308             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1309         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1310         multicall_cv = cv;                                              \
1311         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1312         multicall_cop = CvSTART(cv);                                    \
1313     } STMT_END
1314
1315 #define MULTICALL \
1316     STMT_START {                                                        \
1317         PL_op = multicall_cop;                                          \
1318         CALLRUNOPS(aTHX);                                               \
1319         cx = CX_CUR();                                                  \
1320         LEAVE_SCOPE(saveix_floor);                                      \
1321     } STMT_END
1322
1323 #define POP_MULTICALL \
1324     STMT_START {                                                        \
1325         cx = CX_CUR();                                                  \
1326         CX_LEAVE_SCOPE(cx);                                             \
1327         CX_POPSUB_COMMON(cx);                                           \
1328         newsp = PL_stack_base + cx->blk_oldsp;                          \
1329         gimme = cx->blk_gimme;                                          \
1330         PERL_UNUSED_VAR(newsp); /* for API */                           \
1331         PERL_UNUSED_VAR(gimme); /* for API */                           \
1332         cx_popblock(cx);                                                \
1333         CX_POP(cx);                                                     \
1334         POPSTACK;                                                       \
1335         CATCH_SET(multicall_oldcatch);                                  \
1336         SPAGAIN;                                                        \
1337     } STMT_END
1338
1339 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1340  * (this isn't part of the public API) */
1341
1342 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1343     STMT_START {                                                        \
1344         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1345         CV * const cv = _nOnclAshIngNamE_;                              \
1346         PADLIST * const padlist = CvPADLIST(cv);                        \
1347         cx = CX_CUR();                                                  \
1348         assert(CxMULTICALL(cx));                                        \
1349         CX_POPSUB_COMMON(cx);                                           \
1350         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1351         CX_PUSHSUB(cx, cv, NULL, hasargs);                              \
1352         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1353             CvDEPTH(cv)++;                                              \
1354         if (CvDEPTH(cv) >= 2)                                           \
1355             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1356         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1357         multicall_cv = cv;                                              \
1358         multicall_cop = CvSTART(cv);                                    \
1359     } STMT_END
1360 /*
1361  * ex: set ts=8 sts=4 sw=4 et:
1362  */