Upgrade to Class::ISA 0.36 (Fixes installation directories only)
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 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 three ops OP_NEXTSTATE, OP_DBSTATE,
10  * and OP_SETSTATE 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 start_env initialized when perl starts, and top_env
18  * points to this initially, so top_env should always be non-null.
19  *
20  * Existence of a non-null top_env->je_prev implies it is valid to call
21  * longjmp() at that runlevel (we make sure start_env.je_prev is always
22  * null to ensure this).
23  *
24  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
25  * establish a local jmpenv to handle exception traps.  Care must be taken
26  * to restore the previous value of je_mustcatch before exiting the
27  * stack frame iff JMPENV_PUSH was not called in that stack frame.
28  * GSAR 97-03-27
29  */
30
31 struct jmpenv {
32     struct jmpenv *     je_prev;
33     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
34     int                 je_ret;         /* last exception thrown */
35     bool                je_mustcatch;   /* need to call longjmp()? */
36 };
37
38 typedef struct jmpenv JMPENV;
39
40 #ifdef OP_IN_REGISTER
41 #define OP_REG_TO_MEM   PL_opsave = op
42 #define OP_MEM_TO_REG   op = PL_opsave
43 #else
44 #define OP_REG_TO_MEM   NOOP
45 #define OP_MEM_TO_REG   NOOP
46 #endif
47
48 /*
49  * How to build the first jmpenv.
50  *
51  * top_env needs to be non-zero. It points to an area
52  * in which longjmp() stuff is stored, as C callstack
53  * info there at least is thread specific this has to
54  * be per-thread. Otherwise a 'die' in a thread gives
55  * that thread the C stack of last thread to do an eval {}!
56  */
57
58 #define JMPENV_BOOTSTRAP \
59     STMT_START {                                \
60         Zero(&PL_start_env, 1, JMPENV);         \
61         PL_start_env.je_ret = -1;               \
62         PL_start_env.je_mustcatch = TRUE;       \
63         PL_top_env = &PL_start_env;             \
64     } STMT_END
65
66 /*
67  *   PERL_FLEXIBLE_EXCEPTIONS
68  * 
69  * All the flexible exceptions code has been removed.
70  * See the following threads for details:
71  *
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
73  * 
74  * Joshua's original patches (which weren't applied) and discussion:
75  * 
76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
82  * 
83  * Chip's reworked patch and discussion:
84  * 
85  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
86  * 
87  * The flaw in these patches (which went unnoticed at the time) was
88  * that they moved some code that could potentially die() out of the
89  * region protected by the setjmp()s.  This caused exceptions within
90  * END blocks and such to not be handled by the correct setjmp().
91  * 
92  * The original patches that introduces flexible exceptions were:
93  *
94  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
96  */
97
98 #define dJMPENV         JMPENV cur_env
99
100 #define JMPENV_PUSH(v) \
101     STMT_START {                                                        \
102         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
103                          (void*)&cur_env, (void*)PL_top_env));                  \
104         cur_env.je_prev = PL_top_env;                                   \
105         OP_REG_TO_MEM;                                                  \
106         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
107         OP_MEM_TO_REG;                                                  \
108         PL_top_env = &cur_env;                                          \
109         cur_env.je_mustcatch = FALSE;                                   \
110         (v) = cur_env.je_ret;                                           \
111     } STMT_END
112
113 #define JMPENV_POP \
114     STMT_START {                                                        \
115         DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
116                          (void*)PL_top_env, (void*)cur_env.je_prev));                   \
117         PL_top_env = cur_env.je_prev;                                   \
118     } STMT_END
119
120 #define JMPENV_JUMP(v) \
121     STMT_START {                                                \
122         OP_REG_TO_MEM;                                          \
123         if (PL_top_env->je_prev)                                \
124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
125         if ((v) == 2)                                           \
126             PerlProc_exit(STATUS_EXIT);                         \
127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
128         PerlProc_exit(1);                                       \
129     } STMT_END
130
131 #define CATCH_GET               (PL_top_env->je_mustcatch)
132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
133
134
135 #include "mydtrace.h"
136
137 struct cop {
138     BASEOP
139     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
140        an exact multiple of 8 bytes to save structure padding.  */
141     line_t      cop_line;       /* line # of this command */
142     /* label for this construct is now stored in cop_hints_hash */
143 #ifdef USE_ITHREADS
144     char *      cop_stashpv;    /* package line was compiled in */
145     char *      cop_file;       /* file name the following line # is from */
146 #else
147     HV *        cop_stash;      /* package line was compiled in */
148     GV *        cop_filegv;     /* file the following line # is from */
149 #endif
150     U32         cop_hints;      /* hints bits from pragmata */
151     U32         cop_seq;        /* parse sequence number */
152     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
153     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
154     /* compile time state of %^H.  See the comment in op.c for how this is
155        used to recreate a hash to return from caller.  */
156     struct refcounted_he * cop_hints_hash;
157 };
158
159 #ifdef USE_ITHREADS
160 #  define CopFILE(c)            ((c)->cop_file)
161 #  define CopFILEGV(c)          (CopFILE(c) \
162                                  ? gv_fetchfile(CopFILE(c)) : NULL)
163                                  
164 #  ifdef NETWARE
165 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
166 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
167 #  else
168 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
169 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
170 #  endif
171
172 #  define CopFILESV(c)          (CopFILE(c) \
173                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
174 #  define CopFILEAV(c)          (CopFILE(c) \
175                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
176 #  ifdef DEBUGGING
177 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
178                                    GvAV(gv_fetchfile(CopFILE(c))))
179 #  else
180 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
181 #  endif
182 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
183
184 #  ifdef NETWARE
185 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
186 #  else
187 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
188 #  endif
189
190 #  define CopSTASH(c)           (CopSTASHPV(c) \
191                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
192 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
193 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
194 #  ifdef NETWARE
195 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
196 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
197 #  else
198 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
199 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
200 #  endif
201 #else
202 #  define CopFILEGV(c)          ((c)->cop_filegv)
203 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
204 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
205 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
206 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
207 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
208 #  ifdef DEBUGGING
209 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
210 #  else
211 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
212 # endif
213 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
214                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
215 #  define CopSTASH(c)           ((c)->cop_stash)
216 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
217 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
218    /* cop_stash is not refcounted */
219 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
220 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
221 #  define CopSTASH_free(c)      
222 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
223
224 #endif /* USE_ITHREADS */
225 #define CopLABEL(c)  Perl_fetch_cop_label(aTHX_ (c)->cop_hints_hash, NULL, NULL)
226 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
227
228 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
229 #define CopLINE(c)              ((c)->cop_line)
230 #define CopLINE_inc(c)          (++CopLINE(c))
231 #define CopLINE_dec(c)          (--CopLINE(c))
232 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
233
234 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
235 #define OutCopFILE(c) CopFILE(c)
236
237 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
238    HINT_ARYBASE is set to indicate this.
239    Setting it is ineficient due to the need to create 2 mortal SVs, but as
240    using $[ is highly discouraged, no sane Perl code will be using it.  */
241 #define CopARYBASE_get(c)       \
242         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
243          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
244                                          "$[", 2, 0, 0))                \
245          : 0)
246 #define CopARYBASE_set(c, b) STMT_START { \
247         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
248             (c)->cop_hints |= HINT_ARYBASE;                             \
249             if ((c) == &PL_compiling) {                                 \
250                 SV *val = newSViv(b);                                   \
251                 (void)hv_stores(GvHV(PL_hintgv), "$[", val);            \
252                 mg_set(val);                                            \
253                 PL_hints |= HINT_ARYBASE;                               \
254             } else {                                                    \
255                 (c)->cop_hints_hash                                     \
256                    = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,  \
257                                         newSVpvs_flags("$[", SVs_TEMP), \
258                                         sv_2mortal(newSViv(b)));        \
259             }                                                           \
260         }                                                               \
261     } STMT_END
262
263 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
264 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
265 #define CopHINTS_set(c, h)      STMT_START {                            \
266                                     (c)->cop_hints = (h);               \
267                                 } STMT_END
268
269 /*
270  * Here we have some enormously heavy (or at least ponderous) wizardry.
271  */
272
273 /* subroutine context */
274 struct block_sub {
275     OP *        retop;  /* op to execute on exit from sub */
276     /* Above here is the same for sub, format and eval.  */
277     CV *        cv;
278     /* Above here is the same for sub and format.  */
279     AV *        savearray;
280     AV *        argarray;
281     I32         olddepth;
282     PAD         *oldcomppad;
283 };
284
285
286 /* format context */
287 struct block_format {
288     OP *        retop;  /* op to execute on exit from sub */
289     /* Above here is the same for sub, format and eval.  */
290     CV *        cv;
291     /* Above here is the same for sub and format.  */
292     GV *        gv;
293     GV *        dfoutgv;
294 };
295
296 /* base for the next two macros. Don't use directly.
297  * Note that the refcnt of the cv is incremented twice;  The CX one is
298  * decremented by LEAVESUB, the other by LEAVE. */
299
300 #define PUSHSUB_BASE(cx)                                                \
301         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
302                 CopFILE((const COP *)CvSTART(cv)),                      \
303                 CopLINE((const COP *)CvSTART(cv)));                     \
304                                                                         \
305         cx->blk_sub.cv = cv;                                            \
306         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
307         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
308         cx->blk_sub.retop = NULL;                                       \
309         if (!CvDEPTH(cv)) {                                             \
310             SvREFCNT_inc_simple_void_NN(cv);                            \
311             SvREFCNT_inc_simple_void_NN(cv);                            \
312             SAVEFREESV(cv);                                             \
313         }
314
315
316 #define PUSHSUB(cx)                                                     \
317         PUSHSUB_BASE(cx)                                                \
318         cx->blk_u16 = PL_op->op_private &                               \
319                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
320
321 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
322 #define PUSHSUB_DB(cx)                                                  \
323         PUSHSUB_BASE(cx)                                                \
324         cx->blk_u16 = 0;
325
326
327 #define PUSHFORMAT(cx, retop)                                           \
328         cx->blk_format.cv = cv;                                         \
329         cx->blk_format.gv = gv;                                         \
330         cx->blk_format.retop = (retop);                                 \
331         cx->blk_format.dfoutgv = PL_defoutgv;                           \
332         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
333
334 #define POP_SAVEARRAY()                                         \
335     STMT_START {                                                        \
336         SvREFCNT_dec(GvAV(PL_defgv));                                   \
337         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
338     } STMT_END
339
340 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
341  * leave any (a fast av_clear(ary), basically) */
342 #define CLEAR_ARGARRAY(ary) \
343     STMT_START {                                                        \
344         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
345         AvARRAY(ary) = AvALLOC(ary);                                    \
346         AvFILLp(ary) = -1;                                              \
347     } STMT_END
348
349 #define POPSUB(cx,sv)                                                   \
350     STMT_START {                                                        \
351         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
352                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
353                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)));     \
354                                                                         \
355         if (CxHASARGS(cx)) {                                            \
356             POP_SAVEARRAY();                                            \
357             /* abandon @_ if it got reified */                          \
358             if (AvREAL(cx->blk_sub.argarray)) {                         \
359                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
360                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
361                 cx->blk_sub.argarray = newAV();                         \
362                 av_extend(cx->blk_sub.argarray, fill);                  \
363                 AvREIFY_only(cx->blk_sub.argarray);                     \
364                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
365             }                                                           \
366             else {                                                      \
367                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
368             }                                                           \
369         }                                                               \
370         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
371         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
372             sv = NULL;                                          \
373     } STMT_END
374
375 #define LEAVESUB(sv)                                                    \
376     STMT_START {                                                        \
377         if (sv)                                                         \
378             SvREFCNT_dec(sv);                                           \
379     } STMT_END
380
381 #define POPFORMAT(cx)                                                   \
382         setdefout(cx->blk_format.dfoutgv);                              \
383         SvREFCNT_dec(cx->blk_format.dfoutgv);
384
385 /* eval context */
386 struct block_eval {
387     OP *        retop;  /* op to execute on exit from eval */
388     /* Above here is the same for sub, format and eval.  */
389     SV *        old_namesv;
390     OP *        old_eval_root;
391     SV *        cur_text;
392     CV *        cv;
393     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
394 };
395
396 /* If we ever need more than 512 op types, change the shift from 7.
397    blku_gimme is actually also only 2 bits, so could be merged with something.
398 */
399
400 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
401 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
402
403 #define PUSHEVAL(cx,n)                                                  \
404     STMT_START {                                                        \
405         assert(!(PL_in_eval & ~0x7F));                                  \
406         assert(!(PL_op->op_type & ~0x1FF));                             \
407         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
408         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
409         cx->blk_eval.old_eval_root = PL_eval_root;                      \
410         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
411         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
412         cx->blk_eval.retop = NULL;                                      \
413         cx->blk_eval.cur_top_env = PL_top_env;                          \
414     } STMT_END
415
416 #define POPEVAL(cx)                                                     \
417     STMT_START {                                                        \
418         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
419         optype = CxOLD_OP_TYPE(cx);                                     \
420         PL_eval_root = cx->blk_eval.old_eval_root;                      \
421         if (cx->blk_eval.old_namesv)                                    \
422             sv_2mortal(cx->blk_eval.old_namesv);                        \
423     } STMT_END
424
425 /* loop context */
426 struct block_loop {
427     I32         resetsp;
428     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
429     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
430         why next_op is conditionally defined below.)  */
431 #ifdef USE_ITHREADS
432     PAD         *oldcomppad; /* Also used for the GV, if targoffset is 0 */
433     /* This is also accesible via cx->blk_loop.my_op->op_targ */
434     PADOFFSET   targoffset;
435 #else
436     OP *        next_op;
437     SV **       itervar;
438 #endif
439     union {
440         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
441             AV * ary; /* use the stack if this is NULL */
442             IV ix;
443         } ary;
444         struct { /* valid if type is LOOP_LAZYIV */
445             IV cur;
446             IV end;
447         } lazyiv;
448         struct { /* valid if type if LOOP_LAZYSV */
449             SV * cur;
450             SV * end; /* maxiumum value (or minimum in reverse) */
451         } lazysv;
452     } state_u;
453 };
454
455 #ifdef USE_ITHREADS
456 #  define CxITERVAR(c)                                                  \
457         ((c)->blk_loop.oldcomppad                                       \
458          ? (CxPADLOOP(c)                                                \
459             ? &CX_CURPAD_SV( (c)->blk_loop, (c)->blk_loop.targoffset )  \
460             : &GvSV((GV*)(c)->blk_loop.oldcomppad))                     \
461          : (SV**)NULL)
462 #  define CX_ITERDATA_SET(cx,idata,o)                                   \
463         if ((cx->blk_loop.targoffset = (o)))                            \
464             CX_CURPAD_SAVE(cx->blk_loop);                               \
465         else                                                            \
466             cx->blk_loop.oldcomppad = (idata);
467 #else
468 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
469 #  define CX_ITERDATA_SET(cx,ivar,o)                                    \
470         cx->blk_loop.itervar = (SV**)(ivar);
471 #endif
472 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
473 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
474 #define CxLVAL(c)       (0 + (c)->blk_u16)
475
476 #ifdef USE_ITHREADS
477 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
478 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
479 #else
480 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
481 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
482 #endif
483
484 #define PUSHLOOP_PLAIN(cx, s)                                           \
485         cx->blk_loop.resetsp = s - PL_stack_base;                       \
486         cx->blk_loop.my_op = cLOOP;                                     \
487         PUSHLOOP_OP_NEXT;                                               \
488         cx->blk_loop.state_u.ary.ary = NULL;                            \
489         cx->blk_loop.state_u.ary.ix = 0;                                \
490         CX_ITERDATA_SET(cx, NULL, 0);
491
492 #define PUSHLOOP_FOR(cx, dat, s, offset)                                \
493         cx->blk_loop.resetsp = s - PL_stack_base;                       \
494         cx->blk_loop.my_op = cLOOP;                                     \
495         PUSHLOOP_OP_NEXT;                                               \
496         cx->blk_loop.state_u.ary.ary = NULL;                            \
497         cx->blk_loop.state_u.ary.ix = 0;                                \
498         CX_ITERDATA_SET(cx, dat, offset);
499
500 #define POPLOOP(cx)                                                     \
501         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
502             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
503             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
504         }                                                               \
505         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
506             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
507
508 /* given/when context */
509 struct block_givwhen {
510         OP *leave_op;
511 };
512
513 #define PUSHGIVEN(cx)                                                   \
514         cx->blk_givwhen.leave_op = cLOGOP->op_other;
515
516 #define PUSHWHEN PUSHGIVEN
517
518 /* context common to subroutines, evals and loops */
519 struct block {
520     U8          blku_type;      /* what kind of context this is */
521     U8          blku_gimme;     /* is this block running in list context? */
522     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
523     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
524     COP *       blku_oldcop;    /* old curcop pointer */
525     I32         blku_oldmarksp; /* mark stack index */
526     I32         blku_oldscopesp;        /* scope stack index */
527     PMOP *      blku_oldpm;     /* values of pattern match vars */
528
529     union {
530         struct block_sub        blku_sub;
531         struct block_format     blku_format;
532         struct block_eval       blku_eval;
533         struct block_loop       blku_loop;
534         struct block_givwhen    blku_givwhen;
535     } blk_u;
536 };
537 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
538 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
539 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
540 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
541 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
542 #define blk_gimme       cx_u.cx_blk.blku_gimme
543 #define blk_u16         cx_u.cx_blk.blku_u16
544 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
545 #define blk_format      cx_u.cx_blk.blk_u.blku_format
546 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
547 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
548 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
549
550 /* Enter a block. */
551 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
552         cx->cx_type             = t,                                    \
553         cx->blk_oldsp           = sp - PL_stack_base,                   \
554         cx->blk_oldcop          = PL_curcop,                            \
555         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
556         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
557         cx->blk_oldpm           = PL_curpm,                             \
558         cx->blk_gimme           = (U8)gimme;                            \
559         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
560                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
561
562 /* Exit a block (RETURN and LAST). */
563 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
564         newsp            = PL_stack_base + cx->blk_oldsp,               \
565         PL_curcop        = cx->blk_oldcop,                              \
566         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
567         PL_scopestack_ix = cx->blk_oldscopesp,                          \
568         pm               = cx->blk_oldpm,                               \
569         gimme            = cx->blk_gimme;                               \
570         DEBUG_SCOPE("POPBLOCK");                                        \
571         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
572                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
573
574 /* Continue a block elsewhere (NEXT and REDO). */
575 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
576         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
577         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
578         PL_scopestack_ix = cx->blk_oldscopesp,                          \
579         PL_curpm         = cx->blk_oldpm;                               \
580         DEBUG_SCOPE("TOPBLOCK");
581
582 /* substitution context */
583 struct subst {
584     U8          sbu_type;       /* what kind of context this is */
585     U8          sbu_rflags;
586     U16         sbu_rxtainted;  /* matches struct block */
587     I32         sbu_iters;
588     I32         sbu_maxiters;
589     I32         sbu_oldsave;
590     char *      sbu_orig;
591     SV *        sbu_dstr;
592     SV *        sbu_targ;
593     char *      sbu_s;
594     char *      sbu_m;
595     char *      sbu_strend;
596     void *      sbu_rxres;
597     REGEXP *    sbu_rx;
598 };
599 #define sb_iters        cx_u.cx_subst.sbu_iters
600 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
601 #define sb_rflags       cx_u.cx_subst.sbu_rflags
602 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
603 #define sb_once         cx_u.cx_subst.sbu_once
604 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
605 #define sb_orig         cx_u.cx_subst.sbu_orig
606 #define sb_dstr         cx_u.cx_subst.sbu_dstr
607 #define sb_targ         cx_u.cx_subst.sbu_targ
608 #define sb_s            cx_u.cx_subst.sbu_s
609 #define sb_m            cx_u.cx_subst.sbu_m
610 #define sb_strend       cx_u.cx_subst.sbu_strend
611 #define sb_rxres        cx_u.cx_subst.sbu_rxres
612 #define sb_rx           cx_u.cx_subst.sbu_rx
613
614 #ifdef PERL_CORE
615 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
616         cx->sb_iters            = iters,                                \
617         cx->sb_maxiters         = maxiters,                             \
618         cx->sb_rflags           = r_flags,                              \
619         cx->sb_oldsave          = oldsave,                              \
620         cx->sb_rxtainted        = rxtainted,                            \
621         cx->sb_orig             = orig,                                 \
622         cx->sb_dstr             = dstr,                                 \
623         cx->sb_targ             = targ,                                 \
624         cx->sb_s                = s,                                    \
625         cx->sb_m                = m,                                    \
626         cx->sb_strend           = strend,                               \
627         cx->sb_rxres            = NULL,                                 \
628         cx->sb_rx               = rx,                                   \
629         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
630         rxres_save(&cx->sb_rxres, rx);                                  \
631         (void)ReREFCNT_inc(rx)
632
633 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
634         rxres_free(&cx->sb_rxres);                                      \
635         ReREFCNT_dec(cx->sb_rx)
636 #endif
637
638 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
639
640 struct context {
641     union {
642         struct block    cx_blk;
643         struct subst    cx_subst;
644     } cx_u;
645 };
646 #define cx_type cx_u.cx_subst.sbu_type
647
648 /* If you re-order these, there is also an array of uppercase names in perl.h
649    and a static array of context names in pp_ctl.c  */
650 #define CXTYPEMASK      0xf
651 #define CXt_NULL        0
652 #define CXt_WHEN        1
653 #define CXt_BLOCK       2
654 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
655    jump table in pp_ctl.c
656    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
657 */
658 #define CXt_GIVEN       3
659 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
660 #define CXt_LOOP_FOR    4
661 #define CXt_LOOP_PLAIN  5
662 #define CXt_LOOP_LAZYSV 6
663 #define CXt_LOOP_LAZYIV 7
664 #define CXt_SUB         8
665 #define CXt_FORMAT      9
666 #define CXt_EVAL       10
667 #define CXt_SUBST      11
668 /* SUBST doesn't feature in all switch statements.  */
669
670 /* private flags for CXt_SUB and CXt_NULL
671    However, this is checked in many places which do not check the type, so
672    this bit needs to be kept clear for most everything else. For reasons I
673    haven't investigated, it can coexist with CXp_FOR_DEF */
674 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
675                                    tear down context on exit). */ 
676
677 /* private flags for CXt_SUB and CXt_FORMAT */
678 #define CXp_HASARGS     0x20
679
680 /* private flags for CXt_EVAL */
681 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
682 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
683
684 /* private flags for CXt_LOOP */
685 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
686 #ifdef USE_ITHREADS
687 #  define CxPADLOOP(c)  ((c)->blk_loop.targoffset)
688 #endif
689
690 /* private flags for CXt_SUBST */
691 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
692
693 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
694 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
695 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
696                          == CXp_MULTICALL)
697 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
698                          == (CXt_EVAL|CXp_REAL))
699 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
700                          == (CXt_EVAL|CXp_TRYBLOCK))
701 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
702 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
703                          && ((c)->cx_type & CXp_FOR_DEF))
704
705 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
706
707 /* 
708 =head1 "Gimme" Values
709 */
710
711 /*
712 =for apidoc AmU||G_SCALAR
713 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
714 L<perlcall>.
715
716 =for apidoc AmU||G_ARRAY
717 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
718 L<perlcall>.
719
720 =for apidoc AmU||G_VOID
721 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
722
723 =for apidoc AmU||G_DISCARD
724 Indicates that arguments returned from a callback should be discarded.  See
725 L<perlcall>.
726
727 =for apidoc AmU||G_EVAL
728
729 Used to force a Perl C<eval> wrapper around a callback.  See
730 L<perlcall>.
731
732 =for apidoc AmU||G_NOARGS
733
734 Indicates that no arguments are being sent to a callback.  See
735 L<perlcall>.
736
737 =cut
738 */
739
740 #define G_SCALAR        2
741 #define G_ARRAY         3
742 #define G_VOID          1
743 #define G_WANT          3
744
745 /* extra flags for Perl_call_* routines */
746 #define G_DISCARD       4       /* Call FREETMPS.
747                                    Don't change this without consulting the
748                                    hash actions codes defined in hv.h */
749 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
750 #define G_NOARGS       16       /* Don't construct a @_ array. */
751 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
752 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
753 #define G_METHOD      128       /* Calling method. */
754 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
755                                    fold_constants. */
756
757 /* flag bits for PL_in_eval */
758 #define EVAL_NULL       0       /* not in an eval */
759 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
760 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
761 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
762 #define EVAL_INREQUIRE  8       /* The code is being required. */
763
764 /* Support for switching (stack and block) contexts.
765  * This ensures magic doesn't invalidate local stack and cx pointers.
766  */
767
768 #define PERLSI_UNKNOWN          -1
769 #define PERLSI_UNDEF            0
770 #define PERLSI_MAIN             1
771 #define PERLSI_MAGIC            2
772 #define PERLSI_SORT             3
773 #define PERLSI_SIGNAL           4
774 #define PERLSI_OVERLOAD         5
775 #define PERLSI_DESTROY          6
776 #define PERLSI_WARNHOOK         7
777 #define PERLSI_DIEHOOK          8
778 #define PERLSI_REQUIRE          9
779
780 struct stackinfo {
781     AV *                si_stack;       /* stack for current runlevel */
782     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
783     struct stackinfo *  si_prev;
784     struct stackinfo *  si_next;
785     I32                 si_cxix;        /* current context index */
786     I32                 si_cxmax;       /* maximum allocated index */
787     I32                 si_type;        /* type of runlevel */
788     I32                 si_markoff;     /* offset where markstack begins for us.
789                                          * currently used only with DEBUGGING,
790                                          * but not #ifdef-ed for bincompat */
791 };
792
793 typedef struct stackinfo PERL_SI;
794
795 #define cxstack         (PL_curstackinfo->si_cxstack)
796 #define cxstack_ix      (PL_curstackinfo->si_cxix)
797 #define cxstack_max     (PL_curstackinfo->si_cxmax)
798
799 #ifdef DEBUGGING
800 #  define       SET_MARK_OFFSET \
801     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
802 #else
803 #  define       SET_MARK_OFFSET NOOP
804 #endif
805
806 #define PUSHSTACKi(type) \
807     STMT_START {                                                        \
808         PERL_SI *next = PL_curstackinfo->si_next;                       \
809         if (!next) {                                                    \
810             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
811             next->si_prev = PL_curstackinfo;                            \
812             PL_curstackinfo->si_next = next;                            \
813         }                                                               \
814         next->si_type = type;                                           \
815         next->si_cxix = -1;                                             \
816         AvFILLp(next->si_stack) = 0;                                    \
817         SWITCHSTACK(PL_curstack,next->si_stack);                        \
818         PL_curstackinfo = next;                                         \
819         SET_MARK_OFFSET;                                                \
820     } STMT_END
821
822 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
823
824 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
825  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
826 #define POPSTACK \
827     STMT_START {                                                        \
828         dSP;                                                            \
829         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
830         if (!prev) {                                                    \
831             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
832             my_exit(1);                                                 \
833         }                                                               \
834         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
835         /* don't free prev here, free them all at the END{} */          \
836         PL_curstackinfo = prev;                                         \
837     } STMT_END
838
839 #define POPSTACK_TO(s) \
840     STMT_START {                                                        \
841         while (PL_curstack != s) {                                      \
842             dounwind(-1);                                               \
843             POPSTACK;                                                   \
844         }                                                               \
845     } STMT_END
846
847 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
848 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
849
850 /*
851 =head1 Multicall Functions
852
853 =for apidoc Ams||dMULTICALL
854 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
855
856 =for apidoc Ams||PUSH_MULTICALL
857 Opening bracket for a lightweight callback.
858 See L<perlcall/Lightweight Callbacks>.
859
860 =for apidoc Ams||MULTICALL
861 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
862
863 =for apidoc Ams||POP_MULTICALL
864 Closing bracket for a lightweight callback.
865 See L<perlcall/Lightweight Callbacks>.
866
867 =cut
868 */
869
870 #define dMULTICALL \
871     SV **newsp;                 /* set by POPBLOCK */                   \
872     PERL_CONTEXT *cx;                                                   \
873     CV *multicall_cv;                                                   \
874     OP *multicall_cop;                                                  \
875     bool multicall_oldcatch;                                            \
876     U8 hasargs = 0              /* used by PUSHSUB */
877
878 #define PUSH_MULTICALL(the_cv) \
879     STMT_START {                                                        \
880         CV * const _nOnclAshIngNamE_ = the_cv;                          \
881         CV * const cv = _nOnclAshIngNamE_;                              \
882         AV * const padlist = CvPADLIST(cv);                             \
883         ENTER;                                                          \
884         multicall_oldcatch = CATCH_GET;                                 \
885         SAVETMPS; SAVEVPTR(PL_op);                                      \
886         CATCH_SET(TRUE);                                                \
887         PUSHSTACKi(PERLSI_SORT);                                        \
888         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
889         PUSHSUB(cx);                                                    \
890         if (++CvDEPTH(cv) >= 2) {                                       \
891             PERL_STACK_OVERFLOW_CHECK();                                \
892             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
893         }                                                               \
894         SAVECOMPPAD();                                                  \
895         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
896         multicall_cv = cv;                                              \
897         multicall_cop = CvSTART(cv);                                    \
898     } STMT_END
899
900 #define MULTICALL \
901     STMT_START {                                                        \
902         PL_op = multicall_cop;                                          \
903         CALLRUNOPS(aTHX);                                               \
904     } STMT_END
905
906 #define POP_MULTICALL \
907     STMT_START {                                                        \
908         LEAVESUB(multicall_cv);                                         \
909         CvDEPTH(multicall_cv)--;                                        \
910         POPBLOCK(cx,PL_curpm);                                          \
911         POPSTACK;                                                       \
912         CATCH_SET(multicall_oldcatch);                                  \
913         LEAVE;                                                          \
914         SPAGAIN;                                                        \
915     } STMT_END
916
917 /*
918  * Local variables:
919  * c-indentation-style: bsd
920  * c-basic-offset: 4
921  * indent-tabs-mode: t
922  * End:
923  *
924  * ex: set ts=8 sts=4 sw=4 noet:
925  */