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[perl5.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4  *    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 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     char *      cop_label;      /* label for this construct */
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 #  define CopLABEL(c)           ((c)->cop_label)
195 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
196 #  ifdef NETWARE
197 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
198 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
199 #    define CopLABEL_free(c) SAVECOPLABEL_FREE(c)
200 #    define CopLABEL_alloc(pv)  ((pv)?savepv(pv):NULL)
201 #  else
202 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
203 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
204 #    define CopLABEL_free(c)    (PerlMemShared_free(CopLABEL(c)),(CopLABEL(c) = NULL))
205 #    define CopLABEL_alloc(pv)  ((pv)?savesharedpv(pv):NULL)
206 #  endif
207 #else
208 #  define CopFILEGV(c)          ((c)->cop_filegv)
209 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
210 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
211 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
212 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
213 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
214 #  ifdef DEBUGGING
215 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
216 #  else
217 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
218 # endif
219 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
220                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
221 #  define CopSTASH(c)           ((c)->cop_stash)
222 #  define CopLABEL(c)           ((c)->cop_label)
223 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
224 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
225    /* cop_stash is not refcounted */
226 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
227 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
228 #  define CopLABEL_alloc(pv)    ((pv)?savepv(pv):NULL)
229 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
230 #  define CopSTASH_free(c)      
231 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
232 #  define CopLABEL_free(c)      (Safefree(CopLABEL(c)),(CopLABEL(c) = NULL))
233
234 #endif /* USE_ITHREADS */
235
236 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
237 #define CopLINE(c)              ((c)->cop_line)
238 #define CopLINE_inc(c)          (++CopLINE(c))
239 #define CopLINE_dec(c)          (--CopLINE(c))
240 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
241
242 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
243 #ifdef MACOS_TRADITIONAL
244 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
245 #else
246 #  define OutCopFILE(c) CopFILE(c)
247 #endif
248
249 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
250    HINT_ARYBASE is set to indicate this.
251    Setting it is ineficient due to the need to create 2 mortal SVs, but as
252    using $[ is highly discouraged, no sane Perl code will be using it.  */
253 #define CopARYBASE_get(c)       \
254         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
255          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
256                                          "$[", 2, 0, 0))                \
257          : 0)
258 #define CopARYBASE_set(c, b) STMT_START { \
259         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
260             (c)->cop_hints |= HINT_ARYBASE;                             \
261             if ((c) == &PL_compiling)                                   \
262                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
263             (c)->cop_hints_hash                                         \
264                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
265                                         newSVpvs_flags("$[", SVs_TEMP), \
266                                         sv_2mortal(newSViv(b)));        \
267         }                                                               \
268     } STMT_END
269
270 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
271 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
272 #define CopHINTS_set(c, h)      STMT_START {                            \
273                                     (c)->cop_hints = (h);               \
274                                 } STMT_END
275
276 /*
277  * Here we have some enormously heavy (or at least ponderous) wizardry.
278  */
279
280 /* subroutine context */
281 struct block_sub {
282     OP *        retop;  /* op to execute on exit from sub */
283     /* Above here is the same for sub, format and eval.  */
284     CV *        cv;
285     /* Above here is the same for sub and format.  */
286     AV *        savearray;
287     AV *        argarray;
288     I32         olddepth;
289     PAD         *oldcomppad;
290 };
291
292
293 /* format context */
294 struct block_format {
295     OP *        retop;  /* op to execute on exit from sub */
296     /* Above here is the same for sub, format and eval.  */
297     CV *        cv;
298     /* Above here is the same for sub and format.  */
299     GV *        gv;
300     GV *        dfoutgv;
301 };
302
303 /* base for the next two macros. Don't use directly.
304  * Note that the refcnt of the cv is incremented twice;  The CX one is
305  * decremented by LEAVESUB, the other by LEAVE. */
306
307 #define PUSHSUB_BASE(cx)                                                \
308         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
309                 CopFILE((COP*)CvSTART(cv)),                             \
310                 CopLINE((COP*)CvSTART(cv)));                            \
311                                                                         \
312         cx->blk_sub.cv = cv;                                            \
313         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
314         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
315         cx->blk_sub.retop = NULL;                                       \
316         if (!CvDEPTH(cv)) {                                             \
317             SvREFCNT_inc_simple_void_NN(cv);                            \
318             SvREFCNT_inc_simple_void_NN(cv);                            \
319             SAVEFREESV(cv);                                             \
320         }
321
322
323 #define PUSHSUB(cx)                                                     \
324         PUSHSUB_BASE(cx)                                                \
325         cx->blk_u16 = PL_op->op_private &                               \
326                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
327
328 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
329 #define PUSHSUB_DB(cx)                                                  \
330         PUSHSUB_BASE(cx)                                                \
331         cx->blk_u16 = 0;
332
333
334 #define PUSHFORMAT(cx, retop)                                           \
335         cx->blk_format.cv = cv;                                         \
336         cx->blk_format.gv = gv;                                         \
337         cx->blk_format.retop = (retop);                                 \
338         cx->blk_format.dfoutgv = PL_defoutgv;                           \
339         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
340
341 #define POP_SAVEARRAY()                                         \
342     STMT_START {                                                        \
343         SvREFCNT_dec(GvAV(PL_defgv));                                   \
344         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
345     } STMT_END
346
347 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
348  * leave any (a fast av_clear(ary), basically) */
349 #define CLEAR_ARGARRAY(ary) \
350     STMT_START {                                                        \
351         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
352         AvARRAY(ary) = AvALLOC(ary);                                    \
353         AvFILLp(ary) = -1;                                              \
354     } STMT_END
355
356 #define POPSUB(cx,sv)                                                   \
357     STMT_START {                                                        \
358         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
359                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
360                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
361                                                                         \
362         if (CxHASARGS(cx)) {                                            \
363             POP_SAVEARRAY();                                            \
364             /* abandon @_ if it got reified */                          \
365             if (AvREAL(cx->blk_sub.argarray)) {                         \
366                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
367                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
368                 cx->blk_sub.argarray = newAV();                         \
369                 av_extend(cx->blk_sub.argarray, fill);                  \
370                 AvREIFY_only(cx->blk_sub.argarray);                     \
371                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
372             }                                                           \
373             else {                                                      \
374                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
375             }                                                           \
376         }                                                               \
377         sv = (SV*)cx->blk_sub.cv;                                       \
378         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
379             sv = NULL;                                          \
380     } STMT_END
381
382 #define LEAVESUB(sv)                                                    \
383     STMT_START {                                                        \
384         if (sv)                                                         \
385             SvREFCNT_dec(sv);                                           \
386     } STMT_END
387
388 #define POPFORMAT(cx)                                                   \
389         setdefout(cx->blk_format.dfoutgv);                              \
390         SvREFCNT_dec(cx->blk_format.dfoutgv);
391
392 /* eval context */
393 struct block_eval {
394     OP *        retop;  /* op to execute on exit from eval */
395     /* Above here is the same for sub, format and eval.  */
396     SV *        old_namesv;
397     OP *        old_eval_root;
398     SV *        cur_text;
399     CV *        cv;
400     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
401 };
402
403 /* If we ever need more than 512 op types, change the shift from 7.
404    blku_gimme is actually also only 2 bits, so could be merged with something.
405 */
406
407 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
408 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
409
410 #define PUSHEVAL(cx,n,fgv)                                              \
411     STMT_START {                                                        \
412         assert(!(PL_in_eval & ~0x7F));                                  \
413         assert(!(PL_op->op_type & ~0x1FF));                             \
414         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
415         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
416         cx->blk_eval.old_eval_root = PL_eval_root;                      \
417         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
418         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
419         cx->blk_eval.retop = NULL;                                      \
420         cx->blk_eval.cur_top_env = PL_top_env;                          \
421     } STMT_END
422
423 #define POPEVAL(cx)                                                     \
424     STMT_START {                                                        \
425         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
426         optype = CxOLD_OP_TYPE(cx);                                     \
427         PL_eval_root = cx->blk_eval.old_eval_root;                      \
428         if (cx->blk_eval.old_namesv)                                    \
429             sv_2mortal(cx->blk_eval.old_namesv);                        \
430     } STMT_END
431
432 /* loop context */
433 struct block_loop {
434     I32         resetsp;
435     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
436     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
437         why next_op is conditionally defined below.)  */
438 #ifdef USE_ITHREADS
439     void *      iterdata;
440     PAD         *oldcomppad;
441 #else
442     OP *        next_op;
443     SV **       itervar;
444 #endif
445     SV *        itersave;
446     union {
447         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
448             AV * ary; /* use the stack if this is NULL */
449             IV ix;
450         } ary;
451         struct { /* valid if type is LOOP_LAZYIV */
452             IV cur;
453             IV end;
454         } lazyiv;
455         struct { /* valid if type if LOOP_LAZYSV */
456             SV * cur;
457             SV * end; /* maxiumum value (or minimum in reverse) */
458         } lazysv;
459     } state_u;
460 };
461
462 #ifdef USE_ITHREADS
463 #  define CxITERVAR(c)                                                  \
464         ((c)->blk_loop.iterdata                                         \
465          ? (CxPADLOOP(cx)                                               \
466             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
467                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
468             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
469          : (SV**)NULL)
470 #  define CX_ITERDATA_SET(cx,idata)                                     \
471         CX_CURPAD_SAVE(cx->blk_loop);                                   \
472         if ((cx->blk_loop.iterdata = (idata)) && SvPADMY(*CxITERVAR(cx))) \
473             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
474         else                                                            \
475             cx->blk_loop.itersave = NULL;
476 #else
477 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
478 #  define CX_ITERDATA_SET(cx,ivar)                                      \
479         if ((cx->blk_loop.itervar = (SV**)(ivar))                       \
480             && SvPADMY(*CxITERVAR(cx)))                                 \
481             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
482         else                                                            \
483             cx->blk_loop.itersave = NULL;
484 #endif
485 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
486 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
487 #define CxLVAL(c)       (0 + (c)->blk_u16)
488
489 #ifdef USE_ITHREADS
490 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
491 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
492 #else
493 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
494 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
495 #endif
496
497 #define PUSHLOOP_PLAIN(cx, s)                                           \
498         cx->blk_loop.resetsp = s - PL_stack_base;                       \
499         cx->blk_loop.my_op = cLOOP;                                     \
500         PUSHLOOP_OP_NEXT;                                               \
501         cx->blk_loop.state_u.ary.ary = NULL;                            \
502         cx->blk_loop.state_u.ary.ix = 0;                                \
503         CX_ITERDATA_SET(cx,NULL);
504
505 #define PUSHLOOP_FOR(cx, dat, s)                                        \
506         cx->blk_loop.resetsp = s - PL_stack_base;                       \
507         cx->blk_loop.my_op = cLOOP;                                     \
508         PUSHLOOP_OP_NEXT;                                               \
509         cx->blk_loop.state_u.ary.ary = NULL;                            \
510         cx->blk_loop.state_u.ary.ix = 0;                                \
511         CX_ITERDATA_SET(cx,dat);
512
513 #define POPLOOP(cx)                                                     \
514         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
515             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
516             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
517         }                                                               \
518         if (cx->blk_loop.itersave) {                                    \
519             SV ** const s_v_p = CxITERVAR(cx);                          \
520             assert(SvPADMY(cx->blk_loop.itersave));                     \
521             sv_2mortal(*s_v_p);                                         \
522             *s_v_p = cx->blk_loop.itersave;                             \
523         }                                                               \
524         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
525             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
526
527 /* given/when context */
528 struct block_givwhen {
529         OP *leave_op;
530 };
531
532 #define PUSHGIVEN(cx)                                                   \
533         cx->blk_givwhen.leave_op = cLOGOP->op_other;
534
535 #define PUSHWHEN PUSHGIVEN
536
537 /* context common to subroutines, evals and loops */
538 struct block {
539     U8          blku_type;      /* what kind of context this is */
540     U8          blku_gimme;     /* is this block running in list context? */
541     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
542     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
543     COP *       blku_oldcop;    /* old curcop pointer */
544     I32         blku_oldmarksp; /* mark stack index */
545     I32         blku_oldscopesp;        /* scope stack index */
546     PMOP *      blku_oldpm;     /* values of pattern match vars */
547
548     union {
549         struct block_sub        blku_sub;
550         struct block_format     blku_format;
551         struct block_eval       blku_eval;
552         struct block_loop       blku_loop;
553         struct block_givwhen    blku_givwhen;
554     } blk_u;
555 };
556 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
557 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
558 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
559 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
560 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
561 #define blk_gimme       cx_u.cx_blk.blku_gimme
562 #define blk_u16         cx_u.cx_blk.blku_u16
563 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
564 #define blk_format      cx_u.cx_blk.blk_u.blku_format
565 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
566 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
567 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
568
569 /* Enter a block. */
570 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
571         cx->cx_type             = t,                                    \
572         cx->blk_oldsp           = sp - PL_stack_base,                   \
573         cx->blk_oldcop          = PL_curcop,                            \
574         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
575         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
576         cx->blk_oldpm           = PL_curpm,                             \
577         cx->blk_gimme           = (U8)gimme;                            \
578         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
579                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
580
581 /* Exit a block (RETURN and LAST). */
582 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
583         newsp            = PL_stack_base + cx->blk_oldsp,               \
584         PL_curcop        = cx->blk_oldcop,                              \
585         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
586         PL_scopestack_ix = cx->blk_oldscopesp,                          \
587         pm               = cx->blk_oldpm,                               \
588         gimme            = cx->blk_gimme;                               \
589         DEBUG_SCOPE("POPBLOCK");                                        \
590         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
591                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
592
593 /* Continue a block elsewhere (NEXT and REDO). */
594 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
595         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
596         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
597         PL_scopestack_ix = cx->blk_oldscopesp,                          \
598         PL_curpm         = cx->blk_oldpm;                               \
599         DEBUG_SCOPE("TOPBLOCK");
600
601 /* substitution context */
602 struct subst {
603     U8          sbu_type;       /* what kind of context this is */
604     U8          sbu_rflags;
605     U16         sbu_rxtainted;  /* matches struct block */
606     I32         sbu_iters;
607     I32         sbu_maxiters;
608     I32         sbu_oldsave;
609     char *      sbu_orig;
610     SV *        sbu_dstr;
611     SV *        sbu_targ;
612     char *      sbu_s;
613     char *      sbu_m;
614     char *      sbu_strend;
615     void *      sbu_rxres;
616     REGEXP *    sbu_rx;
617 };
618 #define sb_iters        cx_u.cx_subst.sbu_iters
619 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
620 #define sb_rflags       cx_u.cx_subst.sbu_rflags
621 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
622 #define sb_once         cx_u.cx_subst.sbu_once
623 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
624 #define sb_orig         cx_u.cx_subst.sbu_orig
625 #define sb_dstr         cx_u.cx_subst.sbu_dstr
626 #define sb_targ         cx_u.cx_subst.sbu_targ
627 #define sb_s            cx_u.cx_subst.sbu_s
628 #define sb_m            cx_u.cx_subst.sbu_m
629 #define sb_strend       cx_u.cx_subst.sbu_strend
630 #define sb_rxres        cx_u.cx_subst.sbu_rxres
631 #define sb_rx           cx_u.cx_subst.sbu_rx
632
633 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
634         cx->sb_iters            = iters,                                \
635         cx->sb_maxiters         = maxiters,                             \
636         cx->sb_rflags           = r_flags,                              \
637         cx->sb_oldsave          = oldsave,                              \
638         cx->sb_rxtainted        = rxtainted,                            \
639         cx->sb_orig             = orig,                                 \
640         cx->sb_dstr             = dstr,                                 \
641         cx->sb_targ             = targ,                                 \
642         cx->sb_s                = s,                                    \
643         cx->sb_m                = m,                                    \
644         cx->sb_strend           = strend,                               \
645         cx->sb_rxres            = NULL,                                 \
646         cx->sb_rx               = rx,                                   \
647         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
648         rxres_save(&cx->sb_rxres, rx);                                  \
649         (void)ReREFCNT_inc(rx)
650
651 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
652
653 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
654         rxres_free(&cx->sb_rxres);                                      \
655         ReREFCNT_dec(cx->sb_rx)
656
657 struct context {
658     union {
659         struct block    cx_blk;
660         struct subst    cx_subst;
661     } cx_u;
662 };
663 #define cx_type cx_u.cx_subst.sbu_type
664
665 #define CXTYPEMASK      0xf
666 #define CXt_NULL        0
667 #define CXt_SUB         1
668 #define CXt_EVAL        2
669 #define CXt_WHEN        3
670 #define CXt_SUBST       4
671 #define CXt_BLOCK       5
672 #define CXt_FORMAT      6
673 #define CXt_GIVEN       7
674 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
675 #define CXt_LOOP_FOR    8
676 #define CXt_LOOP_PLAIN  9
677 #define CXt_LOOP_LAZYSV 10
678 #define CXt_LOOP_LAZYIV 11
679
680 /* private flags for CXt_SUB and CXt_NULL
681    However, this is checked in many places which do not check the type, so
682    this bit needs to be kept clear for most everything else. For reasons I
683    haven't investigated, it can coexist with CXp_FOR_DEF */
684 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
685                                    tear down context on exit). */ 
686
687 /* private flags for CXt_SUB and CXt_FORMAT */
688 #define CXp_HASARGS     0x20
689
690 /* private flags for CXt_EVAL */
691 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
692 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
693
694 /* private flags for CXt_LOOP */
695 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
696 #ifdef USE_ITHREADS
697 #  define CXp_PADVAR    0x20    /* itervar lives on pad, iterdata has pad
698                                    offset; if not set, iterdata holds GV* */
699 #  define CxPADLOOP(c)  (CxTYPE_is_LOOP(c) && ((c)->cx_type & (CXp_PADVAR)))
700 #endif
701 /* private flags for CXt_SUBST */
702 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
703
704 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
705 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x8)
706 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
707                          == CXp_MULTICALL)
708 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
709                          == (CXt_EVAL|CXp_REAL))
710 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
711                          == (CXt_EVAL|CXp_TRYBLOCK))
712 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
713 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
714                          && ((c)->cx_type & CXp_FOR_DEF))
715
716 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
717
718 /* 
719 =head1 "Gimme" Values
720 */
721
722 /*
723 =for apidoc AmU||G_SCALAR
724 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
725 L<perlcall>.
726
727 =for apidoc AmU||G_ARRAY
728 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
729 L<perlcall>.
730
731 =for apidoc AmU||G_VOID
732 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
733
734 =for apidoc AmU||G_DISCARD
735 Indicates that arguments returned from a callback should be discarded.  See
736 L<perlcall>.
737
738 =for apidoc AmU||G_EVAL
739
740 Used to force a Perl C<eval> wrapper around a callback.  See
741 L<perlcall>.
742
743 =for apidoc AmU||G_NOARGS
744
745 Indicates that no arguments are being sent to a callback.  See
746 L<perlcall>.
747
748 =cut
749 */
750
751 #define G_SCALAR        2
752 #define G_ARRAY         3
753 #define G_VOID          1
754 #define G_WANT          3
755
756 /* extra flags for Perl_call_* routines */
757 #define G_DISCARD       4       /* Call FREETMPS.
758                                    Don't change this without consulting the
759                                    hash actions codes defined in hv.h */
760 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
761 #define G_NOARGS       16       /* Don't construct a @_ array. */
762 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
763 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
764 #define G_METHOD      128       /* Calling method. */
765 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
766                                    fold_constants. */
767
768 /* flag bits for PL_in_eval */
769 #define EVAL_NULL       0       /* not in an eval */
770 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
771 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
772 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
773 #define EVAL_INREQUIRE  8       /* The code is being required. */
774
775 /* Support for switching (stack and block) contexts.
776  * This ensures magic doesn't invalidate local stack and cx pointers.
777  */
778
779 #define PERLSI_UNKNOWN          -1
780 #define PERLSI_UNDEF            0
781 #define PERLSI_MAIN             1
782 #define PERLSI_MAGIC            2
783 #define PERLSI_SORT             3
784 #define PERLSI_SIGNAL           4
785 #define PERLSI_OVERLOAD         5
786 #define PERLSI_DESTROY          6
787 #define PERLSI_WARNHOOK         7
788 #define PERLSI_DIEHOOK          8
789 #define PERLSI_REQUIRE          9
790
791 struct stackinfo {
792     AV *                si_stack;       /* stack for current runlevel */
793     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
794     struct stackinfo *  si_prev;
795     struct stackinfo *  si_next;
796     I32                 si_cxix;        /* current context index */
797     I32                 si_cxmax;       /* maximum allocated index */
798     I32                 si_type;        /* type of runlevel */
799     I32                 si_markoff;     /* offset where markstack begins for us.
800                                          * currently used only with DEBUGGING,
801                                          * but not #ifdef-ed for bincompat */
802 };
803
804 typedef struct stackinfo PERL_SI;
805
806 #define cxstack         (PL_curstackinfo->si_cxstack)
807 #define cxstack_ix      (PL_curstackinfo->si_cxix)
808 #define cxstack_max     (PL_curstackinfo->si_cxmax)
809
810 #ifdef DEBUGGING
811 #  define       SET_MARK_OFFSET \
812     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
813 #else
814 #  define       SET_MARK_OFFSET NOOP
815 #endif
816
817 #define PUSHSTACKi(type) \
818     STMT_START {                                                        \
819         PERL_SI *next = PL_curstackinfo->si_next;                       \
820         if (!next) {                                                    \
821             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
822             next->si_prev = PL_curstackinfo;                            \
823             PL_curstackinfo->si_next = next;                            \
824         }                                                               \
825         next->si_type = type;                                           \
826         next->si_cxix = -1;                                             \
827         AvFILLp(next->si_stack) = 0;                                    \
828         SWITCHSTACK(PL_curstack,next->si_stack);                        \
829         PL_curstackinfo = next;                                         \
830         SET_MARK_OFFSET;                                                \
831     } STMT_END
832
833 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
834
835 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
836  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
837 #define POPSTACK \
838     STMT_START {                                                        \
839         dSP;                                                            \
840         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
841         if (!prev) {                                                    \
842             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
843             my_exit(1);                                                 \
844         }                                                               \
845         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
846         /* don't free prev here, free them all at the END{} */          \
847         PL_curstackinfo = prev;                                         \
848     } STMT_END
849
850 #define POPSTACK_TO(s) \
851     STMT_START {                                                        \
852         while (PL_curstack != s) {                                      \
853             dounwind(-1);                                               \
854             POPSTACK;                                                   \
855         }                                                               \
856     } STMT_END
857
858 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
859 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
860
861 /*
862 =head1 Multicall Functions
863
864 =for apidoc Ams||dMULTICALL
865 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
866
867 =for apidoc Ams||PUSH_MULTICALL
868 Opening bracket for a lightweight callback.
869 See L<perlcall/Lightweight Callbacks>.
870
871 =for apidoc Ams||MULTICALL
872 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
873
874 =for apidoc Ams||POP_MULTICALL
875 Closing bracket for a lightweight callback.
876 See L<perlcall/Lightweight Callbacks>.
877
878 =cut
879 */
880
881 #define dMULTICALL \
882     SV **newsp;                 /* set by POPBLOCK */                   \
883     PERL_CONTEXT *cx;                                                   \
884     CV *multicall_cv;                                                   \
885     OP *multicall_cop;                                                  \
886     bool multicall_oldcatch;                                            \
887     U8 hasargs = 0              /* used by PUSHSUB */
888
889 #define PUSH_MULTICALL(the_cv) \
890     STMT_START {                                                        \
891         CV * const _nOnclAshIngNamE_ = the_cv;                          \
892         CV * const cv = _nOnclAshIngNamE_;                              \
893         AV * const padlist = CvPADLIST(cv);                             \
894         ENTER;                                                          \
895         multicall_oldcatch = CATCH_GET;                                 \
896         SAVETMPS; SAVEVPTR(PL_op);                                      \
897         CATCH_SET(TRUE);                                                \
898         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
899         PUSHSUB(cx);                                                    \
900         if (++CvDEPTH(cv) >= 2) {                                       \
901             PERL_STACK_OVERFLOW_CHECK();                                \
902             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
903         }                                                               \
904         SAVECOMPPAD();                                                  \
905         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
906         multicall_cv = cv;                                              \
907         multicall_cop = CvSTART(cv);                                    \
908     } STMT_END
909
910 #define MULTICALL \
911     STMT_START {                                                        \
912         PL_op = multicall_cop;                                          \
913         CALLRUNOPS(aTHX);                                               \
914     } STMT_END
915
916 #define POP_MULTICALL \
917     STMT_START {                                                        \
918         LEAVESUB(multicall_cv);                                         \
919         CvDEPTH(multicall_cv)--;                                        \
920         POPBLOCK(cx,PL_curpm);                                          \
921         CATCH_SET(multicall_oldcatch);                                  \
922         LEAVE;                                                          \
923     } STMT_END
924
925 /*
926  * Local variables:
927  * c-indentation-style: bsd
928  * c-basic-offset: 4
929  * indent-tabs-mode: t
930  * End:
931  *
932  * ex: set ts=8 sts=4 sw=4 noet:
933  */