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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 /* free all savestack items back to the watermark of the specified context */
574
575 #define CX_LEAVE_SCOPE(cx) LEAVE_SCOPE(cx->cx_old_savestack_ix)
576
577 #ifdef DEBUGGING
578 /* on debugging builds, poison cx afterwards so we know no code
579  * uses it - because after doing cxstack_ix--, any ties, exceptions etc
580  * may overwrite the current stack frame */
581 #  define CX_POP(cx)                                                   \
582         assert(&cxstack[cxstack_ix] == cx);                            \
583         cxstack_ix--;                                                  \
584         cx = NULL;
585 #else
586 #  define CX_POP(cx) cxstack_ix--;
587 #endif
588
589
590 /* base for the next two macros. Don't use directly.
591  * The context frame holds a reference to the CV so that it can't be
592  * freed while we're executing it */
593
594 #define PUSHSUB_BASE(cx)                                                \
595         ENTRY_PROBE(CvNAMED(cv)                                         \
596                         ? HEK_KEY(CvNAME_HEK(cv))                       \
597                         : GvENAME(CvGV(cv)),                            \
598                 CopFILE((const COP *)CvSTART(cv)),                      \
599                 CopLINE((const COP *)CvSTART(cv)),                      \
600                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
601                                                                         \
602         cx->blk_sub.cv = cv;                                            \
603         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
604         cx->blk_sub.prevcomppad = PL_comppad;                           \
605         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
606         cx->blk_sub.retop = NULL;                                       \
607         SvREFCNT_inc_simple_void_NN(cv);
608
609 #define PUSHSUB_GET_LVALUE_MASK(func) \
610         /* If the context is indeterminate, then only the lvalue */     \
611         /* flags that the caller also has are applicable.        */     \
612         (                                                               \
613            (PL_op->op_flags & OPf_WANT)                                 \
614                ? OPpENTERSUB_LVAL_MASK                                  \
615                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
616                    ? 0 : (U8)func(aTHX)                                 \
617         )
618
619 #define PUSHSUB(cx)                                                     \
620     {                                                                   \
621         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
622         PUSHSUB_BASE(cx)                                                \
623         cx->blk_u16 = PL_op->op_private &                               \
624                           (phlags|OPpDEREF);                            \
625     }
626
627 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
628 #define PUSHSUB_DB(cx)                                                  \
629         PUSHSUB_BASE(cx)                                                \
630         cx->blk_u16 = 0;
631
632
633 #define PUSHFORMAT(cx, retop)                                           \
634         cx->blk_format.cv = cv;                                         \
635         cx->blk_format.gv = gv;                                         \
636         cx->blk_format.retop = (retop);                                 \
637         cx->blk_format.dfoutgv = PL_defoutgv;                           \
638         cx->blk_format.prevcomppad = PL_comppad;                        \
639         cx->blk_u16 = 0;                                                \
640         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
641         SvREFCNT_inc_simple_void_NN(cv);                                \
642         CvDEPTH(cv)++;                                                  \
643         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
644
645 /* Restore old @_ */
646 #define POP_SAVEARRAY()                                         \
647     STMT_START {                                                        \
648         AV *av = GvAV(PL_defgv);                                        \
649         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
650         SvREFCNT_dec(av);                                               \
651     } STMT_END
652
653 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
654  * leave any (a fast av_clear(ary), basically) */
655 #define CLEAR_ARGARRAY(ary) \
656     STMT_START {                                                        \
657         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
658         AvARRAY(ary) = AvALLOC(ary);                                    \
659         AvFILLp(ary) = -1;                                              \
660     } STMT_END
661
662
663 /* subsets of POPSUB */
664
665 #define POPSUB_COMMON(cx) \
666     PL_comppad = cx->blk_sub.prevcomppad;                               \
667     PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;        \
668     CvDEPTH((const CV*)cx->blk_sub.cv) = cx->blk_sub.olddepth;          \
669     SvREFCNT_dec_NN(cx->blk_sub.cv);
670
671 /* handle the @_ part of leaving a sub */
672
673 #define POPSUB_ARGS(cx) \
674     STMT_START {                                                        \
675         AV *av;                                                         \
676         assert(AvARRAY(MUTABLE_AV(                                      \
677             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
678                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
679         POP_SAVEARRAY();                                                \
680         /* abandon @_ if it got reified */                              \
681         av = MUTABLE_AV(PAD_SVl(0));                                    \
682         if (UNLIKELY(AvREAL(av)))                                       \
683             clear_defarray(av, 0);                                      \
684         else {                                                          \
685             CLEAR_ARGARRAY(av);                                         \
686         }                                                               \
687     } STMT_END
688
689 #define POPSUB(cx)                                                      \
690     STMT_START {                                                        \
691         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
692         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
693         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
694                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
695                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
696                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
697                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
698                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
699                                                                         \
700         if (CxHASARGS(cx)) {                                            \
701             POPSUB_ARGS(cx);                                            \
702         }                                                               \
703         }                                                               \
704         POPSUB_COMMON(cx);                                              \
705     } STMT_END
706
707 #define POPFORMAT(cx)                                                   \
708     STMT_START {                                                        \
709         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
710         CV * const cv = cx->blk_format.cv;                              \
711         GV * const dfuot = cx->blk_format.dfoutgv;                      \
712         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
713         setdefout(dfuot);                                               \
714         PL_comppad = cx->blk_format.prevcomppad;                        \
715         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
716         --CvDEPTH(cv);                                                  \
717         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
718         SvREFCNT_dec_NN(dfuot);                                         \
719         }                                                               \
720     } STMT_END
721
722 /* eval context */
723 struct block_eval {
724     OP *        retop;  /* op to execute on exit from eval */
725     /* Above here is the same for sub, format and eval.  */
726     SV *        old_namesv;
727     OP *        old_eval_root;
728     SV *        cur_text;
729     CV *        cv;
730     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
731 };
732
733 /* If we ever need more than 512 op types, change the shift from 7.
734    blku_gimme is actually also only 2 bits, so could be merged with something.
735 */
736
737 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
738 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
739
740 #define PUSHEVAL(cx,n)                                                  \
741     STMT_START {                                                        \
742         assert(!(PL_in_eval & ~0x7F));                                  \
743         assert(!(PL_op->op_type & ~0x1FF));                             \
744         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
745         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
746         cx->blk_eval.old_eval_root = PL_eval_root;                      \
747         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
748         cx->blk_eval.cv = NULL; /* set by doeval_compile() as applicable */ \
749         cx->blk_eval.retop = NULL;                                      \
750         cx->blk_eval.cur_top_env = PL_top_env;                          \
751     } STMT_END
752
753 #define POPEVAL(cx)                                                     \
754     STMT_START {                                                        \
755         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
756         PL_eval_root = cx->blk_eval.old_eval_root;                      \
757         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
758             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
759         if (cx->blk_eval.old_namesv)                                    \
760             sv_2mortal(cx->blk_eval.old_namesv);                        \
761     } STMT_END
762
763 /* loop context */
764 struct block_loop {
765     I32         resetsp;
766     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
767     union {     /* different ways of locating the iteration variable */
768         SV      **svp; /* for lexicals: address of pad slot */
769         GV      *gv;   /* for package vars */
770     } itervar_u;
771     SV          *itersave; /* the original iteration var */
772     union {
773         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
774             AV * ary; /* use the stack if this is NULL */
775             IV ix;
776         } ary;
777         struct { /* valid if type is LOOP_LAZYIV */
778             IV cur;
779             IV end;
780         } lazyiv;
781         struct { /* valid if type if LOOP_LAZYSV */
782             SV * cur;
783             SV * end; /* maxiumum value (or minimum in reverse) */
784         } lazysv;
785     } state_u;
786 #ifdef USE_ITHREADS
787     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
788 #endif
789 };
790
791 #define CxITERVAR(c)                                    \
792         (CxPADLOOP(c)                                   \
793             ? (c)->blk_loop.itervar_u.svp               \
794             : ((c)->cx_type & CXp_FOR_GV)               \
795                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
796                 : (SV **)&(c)->blk_loop.itervar_u.gv)
797
798 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
799 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
800 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
801 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
802 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
803 /* POPSUB has already been performed on this context frame */
804 #define CxPOPSUB_DONE 0x100
805
806
807 #define PUSHLOOP_PLAIN(cx, s)                                           \
808         cx->blk_loop.resetsp = s - PL_stack_base;                       \
809         cx->blk_loop.my_op = cLOOP;                                     \
810         cx->blk_loop.state_u.ary.ary = NULL;                            \
811         cx->blk_loop.state_u.ary.ix = 0;                                \
812         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
813         cx->blk_loop.itervar_u.svp = NULL;                              \
814         cx->blk_loop.itersave = NULL;
815
816 #ifdef USE_ITHREADS
817 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
818 #else
819 #  define PUSHLOOP_FOR_setpad(c) NOOP
820 #endif
821
822 #define PUSHLOOP_FOR(cx, ivar, isave, s)                                \
823         cx->blk_loop.resetsp = s - PL_stack_base;                       \
824         cx->blk_loop.my_op = cLOOP;                                     \
825         cx->blk_loop.state_u.ary.ary = NULL;                            \
826         cx->blk_loop.state_u.ary.ix = 0;                                \
827         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
828         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
829         cx->blk_loop.itersave = isave;                                  \
830         PUSHLOOP_FOR_setpad(cx);
831
832 #define POPLOOP(cx)                                                     \
833         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
834             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
835             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
836         }                                                               \
837         else if (CxTYPE(cx) == CXt_LOOP_FOR)                            \
838             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
839         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
840             SV *cursv;                                                  \
841             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
842             if ((cx->cx_type & CXp_FOR_GV))                             \
843                 svp = &GvSV((GV*)svp);                                  \
844             cursv = *svp;                                               \
845             *svp = cx->blk_loop.itersave;                               \
846             SvREFCNT_dec(cursv);                                        \
847         }
848
849 /* given/when context */
850 struct block_givwhen {
851         OP *leave_op;
852         SV *defsv_save; /* the original $_ */
853 };
854
855 #define PUSHWHEN(cx)                                                    \
856         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
857         cx->blk_givwhen.leave_op = cLOGOP->op_other;
858
859 #define PUSHGIVEN(cx, orig_var)                                         \
860         PUSHWHEN(cx);                                                   \
861         cx->blk_givwhen.defsv_save = orig_var;
862
863 #define POPWHEN(cx)                                                     \
864         NOOP;
865
866 #define POPGIVEN(cx)                                                    \
867         SvREFCNT_dec(GvSV(PL_defgv));                                   \
868         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;
869
870
871 /* basic block, i.e. pp_enter/leave */
872
873 #define PUSHBASICBLK(cx)                                                \
874         cx->cx_old_savestack_ix = PL_savestack_ix;
875
876 #define POPBASICBLK(cx)                                                 \
877         NOOP;
878
879
880 /* context common to subroutines, evals and loops */
881 struct block {
882     U8          blku_type;      /* what kind of context this is */
883     U8          blku_gimme;     /* is this block running in list context? */
884     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
885     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
886     COP *       blku_oldcop;    /* old curcop pointer */
887     I32         blku_oldmarksp; /* mark stack index */
888     I32         blku_oldscopesp;        /* scope stack index */
889     PMOP *      blku_oldpm;     /* values of pattern match vars */
890     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
891
892     union {
893         struct block_sub        blku_sub;
894         struct block_format     blku_format;
895         struct block_eval       blku_eval;
896         struct block_loop       blku_loop;
897         struct block_givwhen    blku_givwhen;
898     } blk_u;
899 };
900 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
901 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
902 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
903 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
904 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
905 #define blk_gimme       cx_u.cx_blk.blku_gimme
906 #define blk_u16         cx_u.cx_blk.blku_u16
907 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
908 #define blk_format      cx_u.cx_blk.blk_u.blku_format
909 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
910 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
911 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
912
913 #define DEBUG_CX(action)                                                \
914     DEBUG_l(                                                            \
915         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
916                     (long)cxstack_ix,                                   \
917                     action,                                             \
918                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
919                     (long)PL_scopestack_ix,                             \
920                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
921                     (long)PL_savestack_ix,                              \
922                     (long)(cxstack[cxstack_ix].cx_old_savestack_ix),    \
923                     __FILE__, __LINE__));
924
925 /* Enter a block. */
926 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
927         cx->cx_type             = t,                                    \
928         cx->blk_oldsp           = sp - PL_stack_base,                   \
929         cx->blk_oldcop          = PL_curcop,                            \
930         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
931         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
932         cx->blk_oldpm           = PL_curpm,                             \
933         cx->blk_gimme           = (U8)gimme;                            \
934         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
935         PL_tmps_floor           = PL_tmps_ix;                           \
936         DEBUG_CX("PUSH");
937
938 /* Exit a block (RETURN and LAST). */
939 #define POPBLOCK(cx)                                                    \
940         DEBUG_CX("POP");                                                \
941         PL_curcop        = cx->blk_oldcop,                              \
942         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
943         PL_scopestack_ix = cx->blk_oldscopesp,                          \
944         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
945          * and leaves a CX entry lying around for repeated use, so
946          * skip for multicall */                  \
947         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
948                 || PL_savestack_ix == cx->cx_old_savestack_ix);         \
949         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
950         PL_curpm         = cx->blk_oldpm;
951
952 /* Continue a block elsewhere (NEXT and REDO). */
953 #define TOPBLOCK(cx)                                                    \
954         DEBUG_CX("TOP");                                                \
955         cx  = &cxstack[cxstack_ix],                                     \
956         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
957         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
958         PL_scopestack_ix = cx->blk_oldscopesp,                          \
959         PL_curpm         = cx->blk_oldpm;
960
961 /* substitution context */
962 struct subst {
963     U8          sbu_type;       /* what kind of context this is */
964     U8          sbu_rflags;
965     U16         sbu_rxtainted;  /* matches struct block */
966     SSize_t     sbu_iters;
967     SSize_t     sbu_maxiters;
968     char *      sbu_orig;
969     SV *        sbu_dstr;
970     SV *        sbu_targ;
971     char *      sbu_s;
972     char *      sbu_m;
973     char *      sbu_strend;
974     void *      sbu_rxres;
975     REGEXP *    sbu_rx;
976 };
977 #define sb_iters        cx_u.cx_subst.sbu_iters
978 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
979 #define sb_rflags       cx_u.cx_subst.sbu_rflags
980 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
981 #define sb_orig         cx_u.cx_subst.sbu_orig
982 #define sb_dstr         cx_u.cx_subst.sbu_dstr
983 #define sb_targ         cx_u.cx_subst.sbu_targ
984 #define sb_s            cx_u.cx_subst.sbu_s
985 #define sb_m            cx_u.cx_subst.sbu_m
986 #define sb_strend       cx_u.cx_subst.sbu_strend
987 #define sb_rxres        cx_u.cx_subst.sbu_rxres
988 #define sb_rx           cx_u.cx_subst.sbu_rx
989
990 #ifdef PERL_CORE
991 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
992         cx->cx_old_savestack_ix = oldsave,                              \
993         cx->sb_iters            = iters,                                \
994         cx->sb_maxiters         = maxiters,                             \
995         cx->sb_rflags           = r_flags,                              \
996         cx->sb_rxtainted        = rxtainted,                            \
997         cx->sb_orig             = orig,                                 \
998         cx->sb_dstr             = dstr,                                 \
999         cx->sb_targ             = targ,                                 \
1000         cx->sb_s                = s,                                    \
1001         cx->sb_m                = m,                                    \
1002         cx->sb_strend           = strend,                               \
1003         cx->sb_rxres            = NULL,                                 \
1004         cx->sb_rx               = rx,                                   \
1005         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1006         rxres_save(&cx->sb_rxres, rx);                                  \
1007         (void)ReREFCNT_inc(rx);                                         \
1008         SvREFCNT_inc_void_NN(targ)
1009
1010 #  define POPSUBST(cx) \
1011         rxres_free(&cx->sb_rxres);                                      \
1012         ReREFCNT_dec(cx->sb_rx);                                        \
1013         SvREFCNT_dec_NN(cx->sb_targ)
1014 #endif
1015
1016 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1017
1018 struct context {
1019     I32                 cx_old_savestack_ix;   /* saved PL_savestack_ix */
1020     union {
1021         struct block    cx_blk;
1022         struct subst    cx_subst;
1023     } cx_u;
1024 };
1025 #define cx_type cx_u.cx_subst.sbu_type
1026
1027 /* If you re-order these, there is also an array of uppercase names in perl.h
1028    and a static array of context names in pp_ctl.c  */
1029 #define CXTYPEMASK      0xf
1030 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1031 #define CXt_WHEN        1
1032 #define CXt_BLOCK       2
1033 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1034    jump table in pp_ctl.c
1035    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1036 */
1037 #define CXt_GIVEN       3
1038 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
1039 #define CXt_LOOP_FOR    4
1040 #define CXt_LOOP_PLAIN  5
1041 #define CXt_LOOP_LAZYSV 6
1042 #define CXt_LOOP_LAZYIV 7
1043 #define CXt_SUB         8
1044 #define CXt_FORMAT      9
1045 #define CXt_EVAL       10
1046 #define CXt_SUBST      11
1047 /* SUBST doesn't feature in all switch statements.  */
1048
1049 /* private flags for CXt_SUB and CXt_FORMAT */
1050 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1051                                    context on exit). (not CXt_FORMAT) */
1052 #define CXp_HASARGS     0x20
1053 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1054 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1055
1056 /* private flags for CXt_EVAL */
1057 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1058 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1059
1060 /* private flags for CXt_LOOP */
1061 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1062 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1063 #define CXp_FOR_GV      0x40    /* foreach using package var */
1064 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1065 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1066
1067 /* private flags for CXt_SUBST */
1068 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1069
1070 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1071 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1072 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1073 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1074                          == (CXt_EVAL|CXp_REAL))
1075 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1076                          == (CXt_EVAL|CXp_TRYBLOCK))
1077 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1078 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1079                          && ((c)->cx_type & CXp_FOR_DEF))
1080
1081 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1082
1083 /* 
1084 =head1 "Gimme" Values
1085 */
1086
1087 /*
1088 =for apidoc AmU||G_SCALAR
1089 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1090 L<perlcall>.
1091
1092 =for apidoc AmU||G_ARRAY
1093 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1094 L<perlcall>.
1095
1096 =for apidoc AmU||G_VOID
1097 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1098
1099 =for apidoc AmU||G_DISCARD
1100 Indicates that arguments returned from a callback should be discarded.  See
1101 L<perlcall>.
1102
1103 =for apidoc AmU||G_EVAL
1104
1105 Used to force a Perl C<eval> wrapper around a callback.  See
1106 L<perlcall>.
1107
1108 =for apidoc AmU||G_NOARGS
1109
1110 Indicates that no arguments are being sent to a callback.  See
1111 L<perlcall>.
1112
1113 =cut
1114 */
1115
1116 #define G_SCALAR        2
1117 #define G_ARRAY         3
1118 #define G_VOID          1
1119 #define G_WANT          3
1120
1121 /* extra flags for Perl_call_* routines */
1122 #define G_DISCARD       4       /* Call FREETMPS.
1123                                    Don't change this without consulting the
1124                                    hash actions codes defined in hv.h */
1125 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1126 #define G_NOARGS       16       /* Don't construct a @_ array. */
1127 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1128 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1129 #define G_METHOD      128       /* Calling method. */
1130 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1131                                    fold_constants. */
1132 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1133                                    A special case for UNSHIFT in
1134                                    Perl_magic_methcall().  */
1135 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1136                                     Perl_magic_methcall().  */
1137 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1138 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1139
1140 /* flag bits for PL_in_eval */
1141 #define EVAL_NULL       0       /* not in an eval */
1142 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1143 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1144 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1145 #define EVAL_INREQUIRE  8       /* The code is being required. */
1146 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1147
1148 /* Support for switching (stack and block) contexts.
1149  * This ensures magic doesn't invalidate local stack and cx pointers.
1150  */
1151
1152 #define PERLSI_UNKNOWN          -1
1153 #define PERLSI_UNDEF            0
1154 #define PERLSI_MAIN             1
1155 #define PERLSI_MAGIC            2
1156 #define PERLSI_SORT             3
1157 #define PERLSI_SIGNAL           4
1158 #define PERLSI_OVERLOAD         5
1159 #define PERLSI_DESTROY          6
1160 #define PERLSI_WARNHOOK         7
1161 #define PERLSI_DIEHOOK          8
1162 #define PERLSI_REQUIRE          9
1163 #define PERLSI_MULTICALL       10
1164
1165 struct stackinfo {
1166     AV *                si_stack;       /* stack for current runlevel */
1167     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1168     struct stackinfo *  si_prev;
1169     struct stackinfo *  si_next;
1170     I32                 si_cxix;        /* current context index */
1171     I32                 si_cxmax;       /* maximum allocated index */
1172     I32                 si_type;        /* type of runlevel */
1173     I32                 si_markoff;     /* offset where markstack begins for us.
1174                                          * currently used only with DEBUGGING,
1175                                          * but not #ifdef-ed for bincompat */
1176 };
1177
1178 typedef struct stackinfo PERL_SI;
1179
1180 #define cxstack         (PL_curstackinfo->si_cxstack)
1181 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1182 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1183
1184 #ifdef DEBUGGING
1185 #  define       SET_MARK_OFFSET \
1186     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1187 #else
1188 #  define       SET_MARK_OFFSET NOOP
1189 #endif
1190
1191 #define PUSHSTACKi(type) \
1192     STMT_START {                                                        \
1193         PERL_SI *next = PL_curstackinfo->si_next;                       \
1194         DEBUG_l({                                                       \
1195             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1196             while (p) { i++; p = p->si_prev; }                          \
1197             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1198                          i, __FILE__, __LINE__);})                      \
1199         if (!next) {                                                    \
1200             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1201             next->si_prev = PL_curstackinfo;                            \
1202             PL_curstackinfo->si_next = next;                            \
1203         }                                                               \
1204         next->si_type = type;                                           \
1205         next->si_cxix = -1;                                             \
1206         AvFILLp(next->si_stack) = 0;                                    \
1207         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1208         PL_curstackinfo = next;                                         \
1209         SET_MARK_OFFSET;                                                \
1210     } STMT_END
1211
1212 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1213
1214 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1215  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1216 #define POPSTACK \
1217     STMT_START {                                                        \
1218         dSP;                                                            \
1219         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1220         DEBUG_l({                                                       \
1221             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1222             while (p) { i++; p = p->si_prev; }                          \
1223             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1224                          i, __FILE__, __LINE__);})                      \
1225         if (!prev) {                                                    \
1226             Perl_croak_popstack();                                      \
1227         }                                                               \
1228         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1229         /* don't free prev here, free them all at the END{} */          \
1230         PL_curstackinfo = prev;                                         \
1231     } STMT_END
1232
1233 #define POPSTACK_TO(s) \
1234     STMT_START {                                                        \
1235         while (PL_curstack != s) {                                      \
1236             dounwind(-1);                                               \
1237             POPSTACK;                                                   \
1238         }                                                               \
1239     } STMT_END
1240
1241 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1242 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1243
1244 /*
1245 =head1 Multicall Functions
1246
1247 =for apidoc Ams||dMULTICALL
1248 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1249
1250 =for apidoc Ams||PUSH_MULTICALL
1251 Opening bracket for a lightweight callback.
1252 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1253
1254 =for apidoc Ams||MULTICALL
1255 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1256
1257 =for apidoc Ams||POP_MULTICALL
1258 Closing bracket for a lightweight callback.
1259 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1260
1261 =cut
1262 */
1263
1264 #define dMULTICALL \
1265     SV **newsp;                 /* set by POPBLOCK */                   \
1266     PERL_CONTEXT *cx;                                                   \
1267     CV *multicall_cv;                                                   \
1268     OP *multicall_cop;                                                  \
1269     bool multicall_oldcatch;                                            \
1270     U8 hasargs = 0              /* used by PUSHSUB */
1271
1272 #define PUSH_MULTICALL(the_cv) \
1273     PUSH_MULTICALL_FLAGS(the_cv, 0)
1274
1275 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1276  * for the CX stack entry (this isn't part of the public API) */
1277
1278 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1279     STMT_START {                                                        \
1280         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1281         CV * const cv = _nOnclAshIngNamE_;                              \
1282         PADLIST * const padlist = CvPADLIST(cv);                        \
1283         multicall_oldcatch = CATCH_GET;                                 \
1284         CATCH_SET(TRUE);                                                \
1285         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1286         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1287         PUSHSUB(cx);                                                    \
1288         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
1289         SAVEVPTR(PL_op);                                                \
1290         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1291             CvDEPTH(cv)++;                                              \
1292         if (CvDEPTH(cv) >= 2) {                                         \
1293             PERL_STACK_OVERFLOW_CHECK();                                \
1294             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1295         }                                                               \
1296         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1297         multicall_cv = cv;                                              \
1298         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1299         multicall_cop = CvSTART(cv);                                    \
1300     } STMT_END
1301
1302 #define MULTICALL \
1303     STMT_START {                                                        \
1304         PL_op = multicall_cop;                                          \
1305         CALLRUNOPS(aTHX);                                               \
1306     } STMT_END
1307
1308 #define POP_MULTICALL \
1309     STMT_START {                                                        \
1310         cx = &cxstack[cxstack_ix];                                      \
1311         CX_LEAVE_SCOPE(cx);                                             \
1312         POPSUB_COMMON(cx);                                              \
1313         newsp = PL_stack_base + cx->blk_oldsp;                          \
1314         gimme = cx->blk_gimme;                                          \
1315         PERL_UNUSED_VAR(newsp); /* for API */                           \
1316         PERL_UNUSED_VAR(gimme); /* for API */                           \
1317         POPBLOCK(cx);                                                   \
1318         CX_POP(cx);                                                     \
1319         POPSTACK;                                                       \
1320         CATCH_SET(multicall_oldcatch);                                  \
1321         SPAGAIN;                                                        \
1322     } STMT_END
1323
1324 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1325  * (this isn't part of the public API) */
1326
1327 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1328     STMT_START {                                                        \
1329         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1330         CV * const cv = _nOnclAshIngNamE_;                              \
1331         PADLIST * const padlist = CvPADLIST(cv);                        \
1332         cx = &cxstack[cxstack_ix];                                      \
1333         assert(CxMULTICALL(cx));                                        \
1334         POPSUB_COMMON(cx);                                              \
1335         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1336         PUSHSUB(cx);                                                    \
1337         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1338             CvDEPTH(cv)++;                                              \
1339         if (CvDEPTH(cv) >= 2) {                                         \
1340             PERL_STACK_OVERFLOW_CHECK();                                \
1341             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1342         }                                                               \
1343         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1344         multicall_cv = cv;                                              \
1345         multicall_cop = CvSTART(cv);                                    \
1346     } STMT_END
1347 /*
1348  * ex: set ts=8 sts=4 sw=4 et:
1349  */