xref: /openbsd-src/gnu/usr.bin/perl/cop.h (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15 
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a PL_start_env initialized when perl starts, and
18  * PL_top_env points to this initially, so PL_top_env should always be
19  * non-null.
20  *
21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
23  * null to ensure this).
24  *
25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
26  * establish a local jmpenv to handle exception traps.  Care must be taken
27  * to restore the previous value of je_mustcatch before exiting the
28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
29  * GSAR 97-03-27
30  */
31 
32 struct jmpenv {
33     struct jmpenv *	je_prev;
34     Sigjmp_buf		je_buf;		/* only for use if !je_throw */
35     int			je_ret;		/* last exception thrown */
36     bool		je_mustcatch;	/* need to call longjmp()? */
37 };
38 
39 typedef struct jmpenv JMPENV;
40 
41 #ifdef OP_IN_REGISTER
42 #define OP_REG_TO_MEM	PL_opsave = op
43 #define OP_MEM_TO_REG	op = PL_opsave
44 #else
45 #define OP_REG_TO_MEM	NOOP
46 #define OP_MEM_TO_REG	NOOP
47 #endif
48 
49 /*
50  * How to build the first jmpenv.
51  *
52  * top_env needs to be non-zero. It points to an area
53  * in which longjmp() stuff is stored, as C callstack
54  * info there at least is thread specific this has to
55  * be per-thread. Otherwise a 'die' in a thread gives
56  * that thread the C stack of last thread to do an eval {}!
57  */
58 
59 #define JMPENV_BOOTSTRAP \
60     STMT_START {				\
61 	Zero(&PL_start_env, 1, JMPENV);		\
62 	PL_start_env.je_ret = -1;		\
63 	PL_start_env.je_mustcatch = TRUE;	\
64 	PL_top_env = &PL_start_env;		\
65     } STMT_END
66 
67 /*
68  *   PERL_FLEXIBLE_EXCEPTIONS
69  *
70  * All the flexible exceptions code has been removed.
71  * See the following threads for details:
72  *
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
74  *
75  * Joshua's original patches (which weren't applied) and discussion:
76  *
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
82  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
83  *
84  * Chip's reworked patch and discussion:
85  *
86  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
87  *
88  * The flaw in these patches (which went unnoticed at the time) was
89  * that they moved some code that could potentially die() out of the
90  * region protected by the setjmp()s.  This caused exceptions within
91  * END blocks and such to not be handled by the correct setjmp().
92  *
93  * The original patches that introduces flexible exceptions were:
94  *
95  * http://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
96  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a
97  *
98  */
99 
100 #define dJMPENV		JMPENV cur_env
101 
102 #define JMPENV_PUSH(v) \
103     STMT_START {							\
104 	DEBUG_l({							\
105 	    int i = 0; JMPENV *p = PL_top_env;				\
106 	    while (p) { i++; p = p->je_prev; }				\
107 	    Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",		\
108 		         i,  __FILE__, __LINE__);})			\
109 	cur_env.je_prev = PL_top_env;					\
110 	OP_REG_TO_MEM;							\
111 	cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);		\
112 	OP_MEM_TO_REG;							\
113 	PL_top_env = &cur_env;						\
114 	cur_env.je_mustcatch = FALSE;					\
115 	(v) = cur_env.je_ret;						\
116     } STMT_END
117 
118 #define JMPENV_POP \
119     STMT_START {							\
120 	DEBUG_l({							\
121 	    int i = -1; JMPENV *p = PL_top_env;				\
122 	    while (p) { i++; p = p->je_prev; }				\
123 	    Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",		\
124 		         i, __FILE__, __LINE__);})			\
125 	assert(PL_top_env == &cur_env);					\
126 	PL_top_env = cur_env.je_prev;					\
127     } STMT_END
128 
129 #define JMPENV_JUMP(v) \
130     STMT_START {						\
131 	DEBUG_l({						\
132 	    int i = -1; JMPENV *p = PL_top_env;			\
133 	    while (p) { i++; p = p->je_prev; }			\
134 	    Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
135 		         (int)v, i, __FILE__, __LINE__);})	\
136 	OP_REG_TO_MEM;						\
137 	if (PL_top_env->je_prev)				\
138 	    PerlProc_longjmp(PL_top_env->je_buf, (v));		\
139 	if ((v) == 2)						\
140 	    PerlProc_exit(STATUS_EXIT);		                \
141 	PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
142 	PerlProc_exit(1);					\
143     } STMT_END
144 
145 #define CATCH_GET		(PL_top_env->je_mustcatch)
146 #define CATCH_SET(v) \
147     STMT_START {							\
148 	DEBUG_l(							\
149 	    Perl_deb(aTHX_						\
150 		"JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",	\
151 		 PL_top_env->je_mustcatch, v, (void*)PL_top_env,	\
152 		 __FILE__, __LINE__);)					\
153 	PL_top_env->je_mustcatch = (v);					\
154     } STMT_END
155 
156 /*
157 =head1 COP Hint Hashes
158 */
159 
160 typedef struct refcounted_he COPHH;
161 
162 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
163 
164 /*
165 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
166 
167 Look up the entry in the cop hints hash I<cophh> with the key specified by
168 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
169 the key octets are interpreted as UTF-8, otherwise they are interpreted
170 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
171 it has not been precomputed.  Returns a mortal scalar copy of the value
172 associated with the key, or C<&PL_sv_placeholder> if there is no value
173 associated with the key.
174 
175 =cut
176 */
177 
178 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
179     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
180 
181 /*
182 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
183 
184 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
185 string/length pair, and no precomputed hash.
186 
187 =cut
188 */
189 
190 #define cophh_fetch_pvs(cophh, key, flags) \
191     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
192 
193 /*
194 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
195 
196 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
197 a string/length pair.
198 
199 =cut
200 */
201 
202 #define cophh_fetch_pv(cophh, key, hash, flags) \
203     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
204 
205 /*
206 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
207 
208 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
209 string/length pair.
210 
211 =cut
212 */
213 
214 #define cophh_fetch_sv(cophh, key, hash, flags) \
215     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
216 
217 /*
218 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
219 
220 Generates and returns a standard Perl hash representing the full set of
221 key/value pairs in the cop hints hash I<cophh>.  I<flags> is currently
222 unused and must be zero.
223 
224 =cut
225 */
226 
227 #define cophh_2hv(cophh, flags) \
228     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
229 
230 /*
231 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
232 
233 Make and return a complete copy of the cop hints hash I<cophh>.
234 
235 =cut
236 */
237 
238 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
239 
240 /*
241 =for apidoc Amx|void|cophh_free|COPHH *cophh
242 
243 Discard the cop hints hash I<cophh>, freeing all resources associated
244 with it.
245 
246 =cut
247 */
248 
249 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
250 
251 /*
252 =for apidoc Amx|COPHH *|cophh_new_empty
253 
254 Generate and return a fresh cop hints hash containing no entries.
255 
256 =cut
257 */
258 
259 #define cophh_new_empty() ((COPHH *)NULL)
260 
261 /*
262 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
263 
264 Stores a value, associated with a key, in the cop hints hash I<cophh>,
265 and returns the modified hash.  The returned hash pointer is in general
266 not the same as the hash pointer that was passed in.  The input hash is
267 consumed by the function, and the pointer to it must not be subsequently
268 used.  Use L</cophh_copy> if you need both hashes.
269 
270 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
271 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
272 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
273 hash of the key string, or zero if it has not been precomputed.
274 
275 I<value> is the scalar value to store for this key.  I<value> is copied
276 by this function, which thus does not take ownership of any reference
277 to it, and later changes to the scalar will not be reflected in the
278 value visible in the cop hints hash.  Complex types of scalar will not
279 be stored with referential integrity, but will be coerced to strings.
280 
281 =cut
282 */
283 
284 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
285     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
286 
287 /*
288 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
289 
290 Like L</cophh_store_pvn>, but takes a literal string instead of a
291 string/length pair, and no precomputed hash.
292 
293 =cut
294 */
295 
296 #define cophh_store_pvs(cophh, key, value, flags) \
297     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
298 
299 /*
300 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
301 
302 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
303 a string/length pair.
304 
305 =cut
306 */
307 
308 #define cophh_store_pv(cophh, key, hash, value, flags) \
309     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
310 
311 /*
312 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
313 
314 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
315 string/length pair.
316 
317 =cut
318 */
319 
320 #define cophh_store_sv(cophh, key, hash, value, flags) \
321     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
322 
323 /*
324 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
325 
326 Delete a key and its associated value from the cop hints hash I<cophh>,
327 and returns the modified hash.  The returned hash pointer is in general
328 not the same as the hash pointer that was passed in.  The input hash is
329 consumed by the function, and the pointer to it must not be subsequently
330 used.  Use L</cophh_copy> if you need both hashes.
331 
332 The key is specified by I<keypv> and I<keylen>.  If I<flags> has the
333 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
334 otherwise they are interpreted as Latin-1.  I<hash> is a precomputed
335 hash of the key string, or zero if it has not been precomputed.
336 
337 =cut
338 */
339 
340 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
341     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
342 	(SV *)NULL, flags)
343 
344 /*
345 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
346 
347 Like L</cophh_delete_pvn>, but takes a literal string instead of a
348 string/length pair, and no precomputed hash.
349 
350 =cut
351 */
352 
353 #define cophh_delete_pvs(cophh, key, flags) \
354     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
355 	(SV *)NULL, flags)
356 
357 /*
358 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
359 
360 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
361 a string/length pair.
362 
363 =cut
364 */
365 
366 #define cophh_delete_pv(cophh, key, hash, flags) \
367     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
368 
369 /*
370 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
371 
372 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
373 string/length pair.
374 
375 =cut
376 */
377 
378 #define cophh_delete_sv(cophh, key, hash, flags) \
379     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
380 
381 #include "mydtrace.h"
382 
383 struct cop {
384     BASEOP
385     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
386        an exact multiple of 8 bytes to save structure padding.  */
387     line_t      cop_line;       /* line # of this command */
388     /* label for this construct is now stored in cop_hints_hash */
389 #ifdef USE_ITHREADS
390     PADOFFSET	cop_stashoff;	/* offset into PL_stashpad, for the
391 				   package the line was compiled in */
392     char *	cop_file;	/* file name the following line # is from */
393 #else
394     HV *	cop_stash;	/* package line was compiled in */
395     GV *	cop_filegv;	/* file the following line # is from */
396 #endif
397     U32		cop_hints;	/* hints bits from pragmata */
398     U32		cop_seq;	/* parse sequence number */
399     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
400     STRLEN *	cop_warnings;	/* lexical warnings bitmask */
401     /* compile time state of %^H.  See the comment in op.c for how this is
402        used to recreate a hash to return from caller.  */
403     COPHH *	cop_hints_hash;
404 };
405 
406 #ifdef USE_ITHREADS
407 #  define CopFILE(c)		((c)->cop_file)
408 #  define CopFILEGV(c)		(CopFILE(c) \
409 				 ? gv_fetchfile(CopFILE(c)) : NULL)
410 
411 #  ifdef NETWARE
412 #    define CopFILE_set(c,pv)	((c)->cop_file = savepv(pv))
413 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
414 #  else
415 #    define CopFILE_set(c,pv)	((c)->cop_file = savesharedpv(pv))
416 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
417 #  endif
418 
419 #  define CopFILESV(c)		(CopFILE(c) \
420 				 ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
421 #  define CopFILEAV(c)		(CopFILE(c) \
422 				 ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
423 #  define CopFILEAVx(c)		(assert_(CopFILE(c)) \
424 				   GvAV(gv_fetchfile(CopFILE(c))))
425 
426 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
427 #  define CopSTASH_set(c,hv)	((c)->cop_stashoff = (hv)		\
428 				    ? alloccopstash(hv)			\
429 				    : 0)
430 #  ifdef NETWARE
431 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
432 #  else
433 #    define CopFILE_free(c)	(PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
434 #  endif
435 #else
436 #  define CopFILEGV(c)		((c)->cop_filegv)
437 #  define CopFILEGV_set(c,gv)	((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
438 #  define CopFILE_set(c,pv)	CopFILEGV_set((c), gv_fetchfile(pv))
439 #  define CopFILE_setn(c,pv,l)	CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
440 #  define CopFILESV(c)		(CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
441 #  define CopFILEAV(c)		(CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
442 #  ifdef DEBUGGING
443 #    define CopFILEAVx(c)	(assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
444 #  else
445 #    define CopFILEAVx(c)	(GvAV(CopFILEGV(c)))
446 # endif
447 #  define CopFILE(c)		(CopFILEGV(c) && GvSV(CopFILEGV(c)) \
448 				    ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
449 #  define CopSTASH(c)		((c)->cop_stash)
450 #  define CopSTASH_set(c,hv)	((c)->cop_stash = (hv))
451 #  define CopFILE_free(c)	(SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
452 
453 #endif /* USE_ITHREADS */
454 
455 #define CopSTASHPV(c)		(CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
456    /* cop_stash is not refcounted */
457 #define CopSTASHPV_set(c,pv)	CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
458 #define CopSTASH_eq(c,hv)	(CopSTASH(c) == (hv))
459 
460 #define CopHINTHASH_get(c)	((COPHH*)((c)->cop_hints_hash))
461 #define CopHINTHASH_set(c,h)	((c)->cop_hints_hash = (h))
462 
463 /*
464 =head1 COP Hint Reading
465 */
466 
467 /*
468 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
469 
470 Look up the hint entry in the cop I<cop> with the key specified by
471 I<keypv> and I<keylen>.  If I<flags> has the C<COPHH_KEY_UTF8> bit set,
472 the key octets are interpreted as UTF-8, otherwise they are interpreted
473 as Latin-1.  I<hash> is a precomputed hash of the key string, or zero if
474 it has not been precomputed.  Returns a mortal scalar copy of the value
475 associated with the key, or C<&PL_sv_placeholder> if there is no value
476 associated with the key.
477 
478 =cut
479 */
480 
481 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
482     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
483 
484 /*
485 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
486 
487 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
488 string/length pair, and no precomputed hash.
489 
490 =cut
491 */
492 
493 #define cop_hints_fetch_pvs(cop, key, flags) \
494     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
495 
496 /*
497 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
498 
499 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
500 of a string/length pair.
501 
502 =cut
503 */
504 
505 #define cop_hints_fetch_pv(cop, key, hash, flags) \
506     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
507 
508 /*
509 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
510 
511 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
512 string/length pair.
513 
514 =cut
515 */
516 
517 #define cop_hints_fetch_sv(cop, key, hash, flags) \
518     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
519 
520 /*
521 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
522 
523 Generates and returns a standard Perl hash representing the full set of
524 hint entries in the cop I<cop>.  I<flags> is currently unused and must
525 be zero.
526 
527 =cut
528 */
529 
530 #define cop_hints_2hv(cop, flags) \
531     cophh_2hv(CopHINTHASH_get(cop), flags)
532 
533 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
534 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
535 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
536 #define CopLABEL_alloc(pv)	((pv)?savepv(pv):NULL)
537 
538 #define CopSTASH_ne(c,hv)	(!CopSTASH_eq(c,hv))
539 #define CopLINE(c)		((c)->cop_line)
540 #define CopLINE_inc(c)		(++CopLINE(c))
541 #define CopLINE_dec(c)		(--CopLINE(c))
542 #define CopLINE_set(c,l)	(CopLINE(c) = (l))
543 
544 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
545 #define OutCopFILE(c) CopFILE(c)
546 
547 #define CopHINTS_get(c)		((c)->cop_hints + 0)
548 #define CopHINTS_set(c, h)	STMT_START {				\
549 				    (c)->cop_hints = (h);		\
550 				} STMT_END
551 
552 /*
553  * Here we have some enormously heavy (or at least ponderous) wizardry.
554  */
555 
556 /* subroutine context */
557 struct block_sub {
558     OP *	retop;	/* op to execute on exit from sub */
559     /* Above here is the same for sub, format and eval.  */
560     CV *	cv;
561     /* Above here is the same for sub and format.  */
562     AV *	savearray;
563     AV *	argarray;
564     I32		olddepth;
565     PAD		*oldcomppad;
566 };
567 
568 
569 /* format context */
570 struct block_format {
571     OP *	retop;	/* op to execute on exit from sub */
572     /* Above here is the same for sub, format and eval.  */
573     CV *	cv;
574     /* Above here is the same for sub and format.  */
575     GV *	gv;
576     GV *	dfoutgv;
577 };
578 
579 /* base for the next two macros. Don't use directly.
580  * Note that the refcnt of the cv is incremented twice;  The CX one is
581  * decremented by LEAVESUB, the other by LEAVE. */
582 
583 #define PUSHSUB_BASE(cx)						\
584 	ENTRY_PROBE(CvNAMED(cv)						\
585 			? HEK_KEY(CvNAME_HEK(cv))			\
586 			: GvENAME(CvGV(cv)),	       			\
587 		CopFILE((const COP *)CvSTART(cv)),			\
588 		CopLINE((const COP *)CvSTART(cv)),			\
589 		CopSTASHPV((const COP *)CvSTART(cv)));			\
590 									\
591 	cx->blk_sub.cv = cv;						\
592 	cx->blk_sub.olddepth = CvDEPTH(cv);				\
593 	cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;			\
594 	cx->blk_sub.retop = NULL;					\
595 	if (!CvDEPTH(cv)) {						\
596 	    SvREFCNT_inc_simple_void_NN(cv);				\
597 	    SvREFCNT_inc_simple_void_NN(cv);				\
598 	    SAVEFREESV(cv);						\
599 	}
600 
601 #define PUSHSUB_GET_LVALUE_MASK(func) \
602 	/* If the context is indeterminate, then only the lvalue */	\
603 	/* flags that the caller also has are applicable.        */	\
604 	(								\
605 	   (PL_op->op_flags & OPf_WANT)					\
606 	       ? OPpENTERSUB_LVAL_MASK					\
607 	       : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)		\
608 	           ? 0 : (U8)func(aTHX)					\
609 	)
610 
611 #define PUSHSUB(cx)							\
612     {									\
613 	U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);	\
614 	PUSHSUB_BASE(cx)						\
615 	cx->blk_u16 = PL_op->op_private &				\
616 	                  (phlags|OPpDEREF);				\
617     }
618 
619 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
620 #define PUSHSUB_DB(cx)							\
621 	PUSHSUB_BASE(cx)						\
622 	cx->blk_u16 = 0;
623 
624 
625 #define PUSHFORMAT(cx, retop)						\
626 	cx->blk_format.cv = cv;						\
627 	cx->blk_format.gv = gv;						\
628 	cx->blk_format.retop = (retop);					\
629 	cx->blk_format.dfoutgv = PL_defoutgv;				\
630 	if (!CvDEPTH(cv)) SvREFCNT_inc_simple_void_NN(cv);		\
631 	CvDEPTH(cv)++;							\
632 	SvREFCNT_inc_void(cx->blk_format.dfoutgv)
633 
634 #define POP_SAVEARRAY()						\
635     STMT_START {							\
636 	SvREFCNT_dec(GvAV(PL_defgv));					\
637 	GvAV(PL_defgv) = cx->blk_sub.savearray;				\
638     } STMT_END
639 
640 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
641  * leave any (a fast av_clear(ary), basically) */
642 #define CLEAR_ARGARRAY(ary) \
643     STMT_START {							\
644 	AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);			\
645 	AvARRAY(ary) = AvALLOC(ary);					\
646 	AvFILLp(ary) = -1;						\
647     } STMT_END
648 
649 #define POPSUB(cx,sv)							\
650     STMT_START {							\
651 	RETURN_PROBE(CvNAMED(cx->blk_sub.cv)				\
652 			? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))		\
653 			: GvENAME(CvGV(cx->blk_sub.cv)),		\
654 		CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),	\
655 		CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),	\
656 		CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));	\
657 									\
658 	if (CxHASARGS(cx)) {						\
659 	    POP_SAVEARRAY();						\
660 	    /* abandon @_ if it got reified */				\
661 	    if (AvREAL(cx->blk_sub.argarray)) {				\
662 		const SSize_t fill = AvFILLp(cx->blk_sub.argarray);	\
663 		SvREFCNT_dec_NN(cx->blk_sub.argarray);			\
664 		cx->blk_sub.argarray = newAV();				\
665 		av_extend(cx->blk_sub.argarray, fill);			\
666 		AvREIFY_only(cx->blk_sub.argarray);			\
667 		CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
668 	    }								\
669 	    else {							\
670 		CLEAR_ARGARRAY(cx->blk_sub.argarray);			\
671 	    }								\
672 	}								\
673 	sv = MUTABLE_SV(cx->blk_sub.cv);				\
674 	if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))	\
675 	    sv = NULL;						\
676     } STMT_END
677 
678 #define LEAVESUB(sv)							\
679     STMT_START {							\
680 	SvREFCNT_dec(sv);						\
681     } STMT_END
682 
683 #define POPFORMAT(cx)							\
684 	setdefout(cx->blk_format.dfoutgv);				\
685 	CvDEPTH(cx->blk_format.cv)--;					\
686 	if (!CvDEPTH(cx->blk_format.cv))				\
687 	    SvREFCNT_dec_NN(cx->blk_format.cv);				\
688 	SvREFCNT_dec_NN(cx->blk_format.dfoutgv);
689 
690 /* eval context */
691 struct block_eval {
692     OP *	retop;	/* op to execute on exit from eval */
693     /* Above here is the same for sub, format and eval.  */
694     SV *	old_namesv;
695     OP *	old_eval_root;
696     SV *	cur_text;
697     CV *	cv;
698     JMPENV *	cur_top_env; /* value of PL_top_env when eval CX created */
699 };
700 
701 /* If we ever need more than 512 op types, change the shift from 7.
702    blku_gimme is actually also only 2 bits, so could be merged with something.
703 */
704 
705 #define CxOLD_IN_EVAL(cx)	(((cx)->blk_u16) & 0x7F)
706 #define CxOLD_OP_TYPE(cx)	(((cx)->blk_u16) >> 7)
707 
708 #define PUSHEVAL(cx,n)							\
709     STMT_START {							\
710 	assert(!(PL_in_eval & ~0x7F));					\
711 	assert(!(PL_op->op_type & ~0x1FF));				\
712 	cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7);	\
713 	cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);		\
714 	cx->blk_eval.old_eval_root = PL_eval_root;			\
715 	cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;	\
716 	cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */	\
717 	cx->blk_eval.retop = NULL;					\
718 	cx->blk_eval.cur_top_env = PL_top_env; 				\
719     } STMT_END
720 
721 #define POPEVAL(cx)							\
722     STMT_START {							\
723 	PL_in_eval = CxOLD_IN_EVAL(cx);					\
724 	optype = CxOLD_OP_TYPE(cx);					\
725 	PL_eval_root = cx->blk_eval.old_eval_root;			\
726 	if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))	\
727 	    SvREFCNT_dec_NN(cx->blk_eval.cur_text);			\
728 	if (cx->blk_eval.old_namesv)					\
729 	    sv_2mortal(cx->blk_eval.old_namesv);			\
730     } STMT_END
731 
732 /* loop context */
733 struct block_loop {
734     I32		resetsp;
735     LOOP *	my_op;	/* My op, that contains redo, next and last ops.  */
736     union {	/* different ways of locating the iteration variable */
737 	SV      **svp;
738 	GV      *gv;
739 	PAD     *oldcomppad; /* only used in ITHREADS */
740     } itervar_u;
741     union {
742 	struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
743 	    AV * ary; /* use the stack if this is NULL */
744 	    IV ix;
745 	} ary;
746 	struct { /* valid if type is LOOP_LAZYIV */
747 	    IV cur;
748 	    IV end;
749 	} lazyiv;
750 	struct { /* valid if type if LOOP_LAZYSV */
751 	    SV * cur;
752 	    SV * end; /* maxiumum value (or minimum in reverse) */
753 	} lazysv;
754     } state_u;
755 };
756 
757 #ifdef USE_ITHREADS
758 #  define CxITERVAR_PADSV(c) \
759 	&CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
760 #else
761 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
762 #endif
763 
764 #define CxITERVAR(c)							\
765 	((c)->blk_loop.itervar_u.oldcomppad				\
766 	 ? (CxPADLOOP(c) 						\
767 	    ? CxITERVAR_PADSV(c)					\
768 	    : &GvSV((c)->blk_loop.itervar_u.gv))			\
769 	 : (SV**)NULL)
770 
771 #define CxLABEL(c)	(0 + CopLABEL((c)->blk_oldcop))
772 #define CxLABEL_len(c,len)	(0 + CopLABEL_len((c)->blk_oldcop, len))
773 #define CxLABEL_len_flags(c,len,flags)	(0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
774 #define CxHASARGS(c)	(((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
775 #define CxLVAL(c)	(0 + (c)->blk_u16)
776 
777 #define PUSHLOOP_PLAIN(cx, s)						\
778 	cx->blk_loop.resetsp = s - PL_stack_base;			\
779 	cx->blk_loop.my_op = cLOOP;					\
780 	cx->blk_loop.state_u.ary.ary = NULL;				\
781 	cx->blk_loop.state_u.ary.ix = 0;				\
782 	cx->blk_loop.itervar_u.svp = NULL;
783 
784 #define PUSHLOOP_FOR(cx, ivar, s)					\
785 	cx->blk_loop.resetsp = s - PL_stack_base;			\
786 	cx->blk_loop.my_op = cLOOP;					\
787 	cx->blk_loop.state_u.ary.ary = NULL;				\
788 	cx->blk_loop.state_u.ary.ix = 0;				\
789 	cx->blk_loop.itervar_u.svp = (SV**)(ivar);
790 
791 #define POPLOOP(cx)							\
792 	if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {				\
793 	    SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);		\
794 	    SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);		\
795 	}								\
796 	if (CxTYPE(cx) == CXt_LOOP_FOR)					\
797 	    SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
798 
799 /* given/when context */
800 struct block_givwhen {
801 	OP *leave_op;
802 };
803 
804 #define PUSHGIVEN(cx)							\
805 	cx->blk_givwhen.leave_op = cLOGOP->op_other;
806 
807 #define PUSHWHEN PUSHGIVEN
808 
809 /* context common to subroutines, evals and loops */
810 struct block {
811     U8		blku_type;	/* what kind of context this is */
812     U8		blku_gimme;	/* is this block running in list context? */
813     U16		blku_u16;	/* used by block_sub and block_eval (so far) */
814     I32		blku_oldsp;	/* stack pointer to copy stuff down to */
815     COP *	blku_oldcop;	/* old curcop pointer */
816     I32		blku_oldmarksp;	/* mark stack index */
817     I32		blku_oldscopesp;	/* scope stack index */
818     PMOP *	blku_oldpm;	/* values of pattern match vars */
819 
820     union {
821 	struct block_sub	blku_sub;
822 	struct block_format	blku_format;
823 	struct block_eval	blku_eval;
824 	struct block_loop	blku_loop;
825 	struct block_givwhen	blku_givwhen;
826     } blk_u;
827 };
828 #define blk_oldsp	cx_u.cx_blk.blku_oldsp
829 #define blk_oldcop	cx_u.cx_blk.blku_oldcop
830 #define blk_oldmarksp	cx_u.cx_blk.blku_oldmarksp
831 #define blk_oldscopesp	cx_u.cx_blk.blku_oldscopesp
832 #define blk_oldpm	cx_u.cx_blk.blku_oldpm
833 #define blk_gimme	cx_u.cx_blk.blku_gimme
834 #define blk_u16		cx_u.cx_blk.blku_u16
835 #define blk_sub		cx_u.cx_blk.blk_u.blku_sub
836 #define blk_format	cx_u.cx_blk.blk_u.blku_format
837 #define blk_eval	cx_u.cx_blk.blk_u.blku_eval
838 #define blk_loop	cx_u.cx_blk.blk_u.blku_loop
839 #define blk_givwhen	cx_u.cx_blk.blk_u.blku_givwhen
840 
841 #define DEBUG_CX(action)						\
842     DEBUG_l(								\
843 	Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",	\
844 		    (long)cxstack_ix,					\
845 		    action,						\
846 		    PL_block_type[CxTYPE(&cxstack[cxstack_ix])],	\
847 		    (long)PL_scopestack_ix,				\
848 		    (long)(cxstack[cxstack_ix].blk_oldscopesp),		\
849 		    __FILE__, __LINE__));
850 
851 /* Enter a block. */
852 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],		\
853 	cx->cx_type		= t,					\
854 	cx->blk_oldsp		= sp - PL_stack_base,			\
855 	cx->blk_oldcop		= PL_curcop,				\
856 	cx->blk_oldmarksp	= PL_markstack_ptr - PL_markstack,	\
857 	cx->blk_oldscopesp	= PL_scopestack_ix,			\
858 	cx->blk_oldpm		= PL_curpm,				\
859 	cx->blk_gimme		= (U8)gimme;				\
860 	DEBUG_CX("PUSH");
861 
862 /* Exit a block (RETURN and LAST). */
863 #define POPBLOCK(cx,pm)							\
864 	DEBUG_CX("POP");						\
865 	cx = &cxstack[cxstack_ix--],					\
866 	newsp		 = PL_stack_base + cx->blk_oldsp,		\
867 	PL_curcop	 = cx->blk_oldcop,				\
868 	PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,		\
869 	PL_scopestack_ix = cx->blk_oldscopesp,				\
870 	pm		 = cx->blk_oldpm,				\
871 	gimme		 = cx->blk_gimme;
872 
873 /* Continue a block elsewhere (NEXT and REDO). */
874 #define TOPBLOCK(cx)							\
875 	DEBUG_CX("TOP");						\
876 	cx  = &cxstack[cxstack_ix],					\
877 	PL_stack_sp	 = PL_stack_base + cx->blk_oldsp,		\
878 	PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,		\
879 	PL_scopestack_ix = cx->blk_oldscopesp,				\
880 	PL_curpm         = cx->blk_oldpm;
881 
882 /* substitution context */
883 struct subst {
884     U8		sbu_type;	/* what kind of context this is */
885     U8		sbu_rflags;
886     U16		sbu_rxtainted;	/* matches struct block */
887     I32		sbu_iters;
888     I32		sbu_maxiters;
889     I32		sbu_oldsave;
890     char *	sbu_orig;
891     SV *	sbu_dstr;
892     SV *	sbu_targ;
893     char *	sbu_s;
894     char *	sbu_m;
895     char *	sbu_strend;
896     void *	sbu_rxres;
897     REGEXP *	sbu_rx;
898 };
899 #define sb_iters	cx_u.cx_subst.sbu_iters
900 #define sb_maxiters	cx_u.cx_subst.sbu_maxiters
901 #define sb_rflags	cx_u.cx_subst.sbu_rflags
902 #define sb_oldsave	cx_u.cx_subst.sbu_oldsave
903 #define sb_rxtainted	cx_u.cx_subst.sbu_rxtainted
904 #define sb_orig		cx_u.cx_subst.sbu_orig
905 #define sb_dstr		cx_u.cx_subst.sbu_dstr
906 #define sb_targ		cx_u.cx_subst.sbu_targ
907 #define sb_s		cx_u.cx_subst.sbu_s
908 #define sb_m		cx_u.cx_subst.sbu_m
909 #define sb_strend	cx_u.cx_subst.sbu_strend
910 #define sb_rxres	cx_u.cx_subst.sbu_rxres
911 #define sb_rx		cx_u.cx_subst.sbu_rx
912 
913 #ifdef PERL_CORE
914 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],		\
915 	cx->sb_iters		= iters,				\
916 	cx->sb_maxiters		= maxiters,				\
917 	cx->sb_rflags		= r_flags,				\
918 	cx->sb_oldsave		= oldsave,				\
919 	cx->sb_rxtainted	= rxtainted,				\
920 	cx->sb_orig		= orig,					\
921 	cx->sb_dstr		= dstr,					\
922 	cx->sb_targ		= targ,					\
923 	cx->sb_s		= s,					\
924 	cx->sb_m		= m,					\
925 	cx->sb_strend		= strend,				\
926 	cx->sb_rxres		= NULL,					\
927 	cx->sb_rx		= rx,					\
928 	cx->cx_type		= CXt_SUBST | (once ? CXp_ONCE : 0);	\
929 	rxres_save(&cx->sb_rxres, rx);					\
930 	(void)ReREFCNT_inc(rx)
931 
932 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];			\
933 	rxres_free(&cx->sb_rxres);					\
934 	ReREFCNT_dec(cx->sb_rx)
935 #endif
936 
937 #define CxONCE(cx)		((cx)->cx_type & CXp_ONCE)
938 
939 struct context {
940     union {
941 	struct block	cx_blk;
942 	struct subst	cx_subst;
943     } cx_u;
944 };
945 #define cx_type cx_u.cx_subst.sbu_type
946 
947 /* If you re-order these, there is also an array of uppercase names in perl.h
948    and a static array of context names in pp_ctl.c  */
949 #define CXTYPEMASK	0xf
950 #define CXt_NULL	0
951 #define CXt_WHEN	1
952 #define CXt_BLOCK	2
953 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
954    jump table in pp_ctl.c
955    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
956 */
957 #define CXt_GIVEN	3
958 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
959 #define CXt_LOOP_FOR	4
960 #define CXt_LOOP_PLAIN	5
961 #define CXt_LOOP_LAZYSV	6
962 #define CXt_LOOP_LAZYIV	7
963 #define CXt_SUB		8
964 #define CXt_FORMAT      9
965 #define CXt_EVAL       10
966 #define CXt_SUBST      11
967 /* SUBST doesn't feature in all switch statements.  */
968 
969 /* private flags for CXt_SUB and CXt_NULL
970    However, this is checked in many places which do not check the type, so
971    this bit needs to be kept clear for most everything else. For reasons I
972    haven't investigated, it can coexist with CXp_FOR_DEF */
973 #define CXp_MULTICALL	0x10	/* part of a multicall (so don't
974 				   tear down context on exit). */
975 
976 /* private flags for CXt_SUB and CXt_FORMAT */
977 #define CXp_HASARGS	0x20
978 #define CXp_SUB_RE	0x40    /* code called within regex, i.e. (?{}) */
979 #define CXp_SUB_RE_FAKE	0x80    /* fake sub CX for (?{}) in current scope */
980 
981 /* private flags for CXt_EVAL */
982 #define CXp_REAL	0x20	/* truly eval'', not a lookalike */
983 #define CXp_TRYBLOCK	0x40	/* eval{}, not eval'' or similar */
984 
985 /* private flags for CXt_LOOP */
986 #define CXp_FOR_DEF	0x10	/* foreach using $_ */
987 #define CxPADLOOP(c)	((c)->blk_loop.my_op->op_targ)
988 
989 /* private flags for CXt_SUBST */
990 #define CXp_ONCE	0x10	/* What was sbu_once in struct subst */
991 
992 #define CxTYPE(c)	((c)->cx_type & CXTYPEMASK)
993 #define CxTYPE_is_LOOP(c)	(((c)->cx_type & 0xC) == 0x4)
994 #define CxMULTICALL(c)	(((c)->cx_type & CXp_MULTICALL)			\
995 			 == CXp_MULTICALL)
996 #define CxREALEVAL(c)	(((c)->cx_type & (CXTYPEMASK|CXp_REAL))		\
997 			 == (CXt_EVAL|CXp_REAL))
998 #define CxTRYBLOCK(c)	(((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))	\
999 			 == (CXt_EVAL|CXp_TRYBLOCK))
1000 #define CxFOREACH(c)	(CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1001 #define CxFOREACHDEF(c)	((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1002 			 && ((c)->cx_type & CXp_FOR_DEF))
1003 
1004 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1005 
1006 /*
1007 =head1 "Gimme" Values
1008 */
1009 
1010 /*
1011 =for apidoc AmU||G_SCALAR
1012 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
1013 L<perlcall>.
1014 
1015 =for apidoc AmU||G_ARRAY
1016 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
1017 L<perlcall>.
1018 
1019 =for apidoc AmU||G_VOID
1020 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
1021 
1022 =for apidoc AmU||G_DISCARD
1023 Indicates that arguments returned from a callback should be discarded.  See
1024 L<perlcall>.
1025 
1026 =for apidoc AmU||G_EVAL
1027 
1028 Used to force a Perl C<eval> wrapper around a callback.  See
1029 L<perlcall>.
1030 
1031 =for apidoc AmU||G_NOARGS
1032 
1033 Indicates that no arguments are being sent to a callback.  See
1034 L<perlcall>.
1035 
1036 =cut
1037 */
1038 
1039 #define G_SCALAR	2
1040 #define G_ARRAY		3
1041 #define G_VOID		1
1042 #define G_WANT		3
1043 
1044 /* extra flags for Perl_call_* routines */
1045 #define G_DISCARD	4	/* Call FREETMPS.
1046 				   Don't change this without consulting the
1047 				   hash actions codes defined in hv.h */
1048 #define G_EVAL		8	/* Assume eval {} around subroutine call. */
1049 #define G_NOARGS       16	/* Don't construct a @_ array. */
1050 #define G_KEEPERR      32	/* Warn for errors, don't overwrite $@ */
1051 #define G_NODEBUG      64	/* Disable debugging at toplevel.  */
1052 #define G_METHOD      128       /* Calling method. */
1053 #define G_FAKINGEVAL  256	/* Faking an eval context for call_sv or
1054 				   fold_constants. */
1055 #define G_UNDEF_FILL  512	/* Fill the stack with &PL_sv_undef
1056 				   A special case for UNSHIFT in
1057 				   Perl_magic_methcall().  */
1058 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1059 				    Perl_magic_methcall().  */
1060 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1061 
1062 /* flag bits for PL_in_eval */
1063 #define EVAL_NULL	0	/* not in an eval */
1064 #define EVAL_INEVAL	1	/* some enclosing scope is an eval */
1065 #define EVAL_WARNONLY	2	/* used by yywarn() when calling yyerror() */
1066 #define EVAL_KEEPERR	4	/* set by Perl_call_sv if G_KEEPERR */
1067 #define EVAL_INREQUIRE	8	/* The code is being required. */
1068 #define EVAL_RE_REPARSING 0x10	/* eval_sv() called with G_RE_REPARSING */
1069 
1070 /* Support for switching (stack and block) contexts.
1071  * This ensures magic doesn't invalidate local stack and cx pointers.
1072  */
1073 
1074 #define PERLSI_UNKNOWN		-1
1075 #define PERLSI_UNDEF		0
1076 #define PERLSI_MAIN		1
1077 #define PERLSI_MAGIC		2
1078 #define PERLSI_SORT		3
1079 #define PERLSI_SIGNAL		4
1080 #define PERLSI_OVERLOAD		5
1081 #define PERLSI_DESTROY		6
1082 #define PERLSI_WARNHOOK		7
1083 #define PERLSI_DIEHOOK		8
1084 #define PERLSI_REQUIRE		9
1085 
1086 struct stackinfo {
1087     AV *		si_stack;	/* stack for current runlevel */
1088     PERL_CONTEXT *	si_cxstack;	/* context stack for runlevel */
1089     struct stackinfo *	si_prev;
1090     struct stackinfo *	si_next;
1091     I32			si_cxix;	/* current context index */
1092     I32			si_cxmax;	/* maximum allocated index */
1093     I32			si_type;	/* type of runlevel */
1094     I32			si_markoff;	/* offset where markstack begins for us.
1095 					 * currently used only with DEBUGGING,
1096 					 * but not #ifdef-ed for bincompat */
1097 };
1098 
1099 typedef struct stackinfo PERL_SI;
1100 
1101 #define cxstack		(PL_curstackinfo->si_cxstack)
1102 #define cxstack_ix	(PL_curstackinfo->si_cxix)
1103 #define cxstack_max	(PL_curstackinfo->si_cxmax)
1104 
1105 #ifdef DEBUGGING
1106 #  define	SET_MARK_OFFSET \
1107     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1108 #else
1109 #  define	SET_MARK_OFFSET NOOP
1110 #endif
1111 
1112 #define PUSHSTACKi(type) \
1113     STMT_START {							\
1114 	PERL_SI *next = PL_curstackinfo->si_next;			\
1115 	DEBUG_l({							\
1116 	    int i = 0; PERL_SI *p = PL_curstackinfo;			\
1117 	    while (p) { i++; p = p->si_prev; }				\
1118 	    Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",		\
1119 		         i, __FILE__, __LINE__);})			\
1120 	if (!next) {							\
1121 	    next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);	\
1122 	    next->si_prev = PL_curstackinfo;				\
1123 	    PL_curstackinfo->si_next = next;				\
1124 	}								\
1125 	next->si_type = type;						\
1126 	next->si_cxix = -1;						\
1127 	AvFILLp(next->si_stack) = 0;					\
1128 	SWITCHSTACK(PL_curstack,next->si_stack);			\
1129 	PL_curstackinfo = next;						\
1130 	SET_MARK_OFFSET;						\
1131     } STMT_END
1132 
1133 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1134 
1135 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1136  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1137 #define POPSTACK \
1138     STMT_START {							\
1139 	dSP;								\
1140 	PERL_SI * const prev = PL_curstackinfo->si_prev;		\
1141 	DEBUG_l({							\
1142 	    int i = -1; PERL_SI *p = PL_curstackinfo;			\
1143 	    while (p) { i++; p = p->si_prev; }				\
1144 	    Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",		\
1145 		         i, __FILE__, __LINE__);})			\
1146 	if (!prev) {							\
1147 	    Perl_croak_popstack();					\
1148 	}								\
1149 	SWITCHSTACK(PL_curstack,prev->si_stack);			\
1150 	/* don't free prev here, free them all at the END{} */		\
1151 	PL_curstackinfo = prev;						\
1152     } STMT_END
1153 
1154 #define POPSTACK_TO(s) \
1155     STMT_START {							\
1156 	while (PL_curstack != s) {					\
1157 	    dounwind(-1);						\
1158 	    POPSTACK;							\
1159 	}								\
1160     } STMT_END
1161 
1162 #define IN_PERL_COMPILETIME	(PL_curcop == &PL_compiling)
1163 #define IN_PERL_RUNTIME		(PL_curcop != &PL_compiling)
1164 
1165 /*
1166 =head1 Multicall Functions
1167 
1168 =for apidoc Ams||dMULTICALL
1169 Declare local variables for a multicall. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1170 
1171 =for apidoc Ams||PUSH_MULTICALL
1172 Opening bracket for a lightweight callback.
1173 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1174 
1175 =for apidoc Ams||MULTICALL
1176 Make a lightweight callback. See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1177 
1178 =for apidoc Ams||POP_MULTICALL
1179 Closing bracket for a lightweight callback.
1180 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1181 
1182 =cut
1183 */
1184 
1185 #define dMULTICALL \
1186     SV **newsp;			/* set by POPBLOCK */			\
1187     PERL_CONTEXT *cx;							\
1188     CV *multicall_cv;							\
1189     OP *multicall_cop;							\
1190     bool multicall_oldcatch; 						\
1191     U8 hasargs = 0		/* used by PUSHSUB */
1192 
1193 #define PUSH_MULTICALL(the_cv) \
1194     PUSH_MULTICALL_FLAGS(the_cv, 0)
1195 
1196 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1197  * for the CX stack entry (this isn't part of the public API) */
1198 
1199 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1200     STMT_START {							\
1201 	CV * const _nOnclAshIngNamE_ = the_cv;				\
1202 	CV * const cv = _nOnclAshIngNamE_;				\
1203 	PADLIST * const padlist = CvPADLIST(cv);			\
1204 	ENTER;								\
1205  	multicall_oldcatch = CATCH_GET;					\
1206 	SAVETMPS; SAVEVPTR(PL_op);					\
1207 	CATCH_SET(TRUE);						\
1208 	PUSHSTACKi(PERLSI_SORT);					\
1209 	PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);	\
1210 	PUSHSUB(cx);							\
1211         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1212             CvDEPTH(cv)++;						\
1213 	if (CvDEPTH(cv) >= 2) {						\
1214 	    PERL_STACK_OVERFLOW_CHECK();				\
1215 	    Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));			\
1216 	}								\
1217 	SAVECOMPPAD();							\
1218 	PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));			\
1219 	multicall_cv = cv;						\
1220 	multicall_cop = CvSTART(cv);					\
1221     } STMT_END
1222 
1223 #define MULTICALL \
1224     STMT_START {							\
1225 	PL_op = multicall_cop;						\
1226 	CALLRUNOPS(aTHX);						\
1227     } STMT_END
1228 
1229 #define POP_MULTICALL \
1230     STMT_START {							\
1231 	cx = &cxstack[cxstack_ix];					\
1232         if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {	\
1233 		LEAVESUB(multicall_cv);					\
1234 	}								\
1235 	POPBLOCK(cx,PL_curpm);						\
1236 	POPSTACK;							\
1237 	CATCH_SET(multicall_oldcatch);					\
1238 	LEAVE;								\
1239 	SPAGAIN;							\
1240     } STMT_END
1241 
1242 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1243  * (this isn't part of the public API) */
1244 
1245 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1246     STMT_START {							\
1247 	CV * const _nOnclAshIngNamE_ = the_cv;				\
1248 	CV * const cv = _nOnclAshIngNamE_;				\
1249 	PADLIST * const padlist = CvPADLIST(cv);			\
1250 	cx = &cxstack[cxstack_ix];					\
1251 	assert(cx->cx_type & CXp_MULTICALL);				\
1252 	if (! ((CvDEPTH(multicall_cv) = cx->blk_sub.olddepth)) ) {	\
1253 		LEAVESUB(multicall_cv);					\
1254 	}								\
1255 	cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1256 	PUSHSUB(cx);							\
1257         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1258             CvDEPTH(cv)++;						\
1259 	if (CvDEPTH(cv) >= 2) {						\
1260 	    PERL_STACK_OVERFLOW_CHECK();				\
1261 	    Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));			\
1262 	}								\
1263 	SAVECOMPPAD();							\
1264 	PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));			\
1265 	multicall_cv = cv;						\
1266 	multicall_cop = CvSTART(cv);					\
1267     } STMT_END
1268 /*
1269  * Local variables:
1270  * c-indentation-style: bsd
1271  * c-basic-offset: 4
1272  * indent-tabs-mode: nil
1273  * End:
1274  *
1275  * ex: set ts=8 sts=4 sw=4 et:
1276  */
1277